Message from Division Chair
This year’s in-person sessions will be held at:
- Central Department of Physics, Tribhuvan University, Kirtipur, Nepal
- Fairmont State University, Fairmont, WV USA
Please look below for a detailed schedule.
Important Links
View Presentation Schedule
Conference Timeline
Invited Speaker
Neutron Diffraction and Electronic Structure Investigation of Er-α-SiAlON for High-Temperature Sensing
α-SiAlON ceramics have been in use as engineering ceramics in the most arduous industrial environments such as molten metal handling, cutting tools, gas turbine engines, extrusion molds, thermocouple sheaths, protective cover for high-temperature sensors, etc., owing to their outstanding mechanical, thermal, and chemical stability.1 Taking advantage of the intrinsic properties of α-SiAlONs, we investigate the possibility of using the Er-doped α-SiAlON (Er-α-SiAlON) ceramic as a high-temperature sensing material via its unique near-infrared to visible upconversion property.2 We first use neutron diffraction and density functional theory calculations to study the electronic structure and thermodynamic stability of Er-α-SiAlON. Neutron diffraction is particularly essential in this study, as X-ray diffraction alone cannot precisely determine the atomic positions due to the similar X-ray scattering cross-sections of oxygen (O) and nitrogen (N) atoms. In contrast, neutron diffraction provides significantly different scattering cross-sections for O and N, enabling accurate crystal structure identification of SiAlON ceramics. It is found that the interstitial doping of Er stabilizes the α-SiAlON structure via chemical bonds with O-atoms with an N:O ratio of 5:2 in the seven-fold coordination sites of the Er3+ ion. Temperature-dependent upconversion emissions are then studied under 980 and 793 nm excitations over a temperature range of 298–1373 K, and the fluorescence intensity ratio (FIR) technique has been employed to investigate the temperature sensing behavior. Temperature-dependent Raman behavior is also investigated. We demonstrate that using Er-α-SiAlON as a sensing material, the limit of temperature measurement via the FIR technique can be pushed well beyond 1200 K.2
[1] Nature 274 (1978) 880–882.
[2] Scientific Reports 10 (2020) 4952.
Division Schedule
Fairmont Schedule.
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Abstract Number: ANPA2025-N00050 Presenting Author: Prashnna Gyawali Co-Authors: Chowdhury Mohammad Abid Rahman; Aldo H. Romero Presenter's Affiliation: West Virginia University Title: Supervised Pretraining for Material Property Prediction Location: In-Person Presentation, Fairmont Show/Hide Abstract Accurate prediction of material properties facilitates the discovery of novel materials with tailored functionalities. Deep learning models have recently shown superior accuracy and flexibility in capturing structure-property relationships. However, these models often rely on supervised learning, which requires large, well-annotated datasets—an expensive and time-consuming process. Self-supervised learning (SSL) offers a promising alternative by pretraining on large, unlabeled datasets to develop foundation models that can be fine-tuned for material property prediction. In this work, we propose supervised pretraining, where available class information serves as surrogate labels to guide learning, even when downstream tasks involve unrelated material properties. We evaluate this strategy on two state-of-the-art SSL models and introduce a novel framework for supervised pretraining. To further enhance representation learning, we propose a graph-based augmentation technique that injects noise to improve robustness without structurally deforming material graphs.
The resulting foundation models are fine-tuned for six challenging material property predictions, achieving significant performance gains over baselines, ranging from 2\% to 6.67\% improvement in mean absolute error (MAE)—and establishing a new benchmark in material property prediction. This study represents the first exploration of supervised pertaining with surrogate labels in material property prediction, advancing methodology and application in the field.
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Abstract Number: ANPA2025-N00046 Presenting Author: Basu Dev Oli Co-Authors: Qiang Zou; Subhasish Mandal; Lian Li Presenter's Affiliation: Department of Physics and Astronomy, West Virginia University Title: Engineering superconductivity in Single-layer FeSe through Substrate Surface Terminations Location: In-Person Presentation, Fairmont Show/Hide Abstract The discovery of high-temperature superconductivity in single-layer FeSe films grown on (001) SrTiO3 (STO) substrates has sparked extensive research into the underlying mechanisms. Most studies have focused on FeSe films grown on TiO2-terminated STO substrates, while several models have been proposed to explain the enhanced superconductivity. In this work, we synthesized FeSe films on both TiO2- and SrO-terminated STO substrates by molecular beam epitaxy and compared their superconducting properties by scanning tunneling microscopy/spectroscopy (STM/STS). dI/dV tunneling spectroscopy reveals a larger superconducting gap of ï„ = 17 meV on FeSe/TiO2 regions, while a smaller gap of ï„ = 11 meV on FeSe/SrO. By comparing experimental findings with dynamical mean field theory calculations, our results indicate optimal electron correlations at the FeSe-TiO2 interface for enhancing superconductivity in single-layer FeSe.
This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering (DE-SC0017632).
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Abstract Number: ANPA2025-N00052 Presenting Author: Dinesh Thapa Co-Authors: Sumon Hati; Rajesh Sardar; Svetlana Kilina Presenter's Affiliation: Thomas More University Title: Ultralow work function modulation via interfacial dipole formation in gold metal organic framework Location: In-Person Presentation, Fairmont Show/Hide Abstract The chemistry of the gold metal organic frameworks (MOFs) has increased considerably in recent decades because of their structural diversity, chemical versatility, and selective adsorptions to apply in numerous fields of catalysis, sensing, gas sorption, organic electrodes, and biomedicine. In this work, we perform the theoretical and experimental tailoring of the work function of the gold (Au) (111) surface adsorbed with various organic molecules together with the determination of dipole moment and charge transfer along the interfaces. We implemented the state-of-art spin polarized density functional theory (DFT) to modulate the work function of the organically modified Au (111) surface manifested by a strong dipole formation at the interfaces. The substrate work function is found to be lowered by ~0.7-0.9 eV compared to pristine Au (111) surface due to subtle interplay between Pauli’s push back effect and the substantial transfer of electrons (~1.0e-1.7e) from the Au metal to the adsorbed organic molecule. The ultralow work function thus obtained is further supported by the formation of interfacial dipole pointing towards the metal, with dipole moment value as large as 3.6 Debye (in linear chain of benzene rings) to 4.9 Debye (in fused benzene rings). Our computational modeling and experimental observations provide an invaluable tool to actually understand the detailed mechanism behind the observed work function reduction via the ever-existent Pauli repulsion. Here, the interacting metal electrons are pushed back into the metal due to Coulomb repulsion from the electrons localized at the adsorbate, thereby lowering the work function. Owing to the reduced work function value and quantized charge separations at the interface, our proposed MOFs hold particularly high promise for using as electron injecting electrodes into organic electronic devices.
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Abstract Number: ANPA2025-N00016 Presenting Author: Bishnu Sedai Co-Authors: nan Presenter's Affiliation: Fairmont State University Title: Spectral Shift Functions for One-Dimensional Schrödinger Operators Location: In-Person Presentation, Fairmont Show/Hide Abstract In quantum mechanics and operator theory, the spectral shift function (SSF) measures how the spectrum of an operator changes under perturbations. For one-dimensional Schrödinger operators, the SSF provides information on scattering behavior, eigenvalue changes, and trace formulas. In this talk, we will present the SSF, elucidate its derivation from Krein's trace formula, and demonstrate its explicit computation through basic one-dimensional examples. We begin with a constant potential shift, where the entire spectrum rigidly translates, then explore delta and square-well potentials to understand localized spectral changes. The goal is to make this powerful analytical tool accessible to undergraduate researchers while illustrating its deep connections to quantum physics.
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Abstract Number: ANPA2025-N00022 Presenting Author: Dipendra Khatri Co-Authors: Christopher Lantigua, Tran-Chau Truong, Chelsea Kincaid, Eric Van Stryland, and Michael Chini Presenter's Affiliation: University of Central Florida Title: Measurement of Real-Time Evolution of Vibrational Nonlinearity in Fused Silica Location: In-Person Presentation, Fairmont Show/Hide Abstract We present field-resolved measurements of vibrational nonlinearity in fused silica using sub-10 femtosecond pulses at 1 micron, generated via a two-stage hybrid compression system. These ultrashort pulses, derived from a Yb:KGW regenerative amplifier and spectrally broadened through gas-filled multi-pass cells and hollow-core fibers, enable probing of phonon dynamics on timescales shorter than the material's phonon coherence time.
To capture the real-time vibrational response, we employ the TIPTOE (tunnel ionization with perturbation for time-domain observation of the electric field) technique, utilizing a solar-blind AlGaN photodiode as both nonlinear medium and detector. This adaptation allows us to observe the nonlinear vibrational dynamics driven by the ultrashort pulses. Comparing signals with and without the sample isolates the material-specific response, revealing coherent phonon oscillations in fused silica.
By extracting the electric field envelopes and performing Fourier analysis, we obtain the Raman gain spectrum of fused silica, which shows strong agreement with theoretical predictions based on Stolen’s model. These results provide direct insight into the vibrational nonlinearities of fused silica, a material widely used in ultrafast optics but with incompletely understood phonon dynamics.
Our work offers a valuable method for investigating ultrafast vibrational phenomena in dielectric materials and contributes to the broader understanding of nonlinear optical processes relevant for applications in ultrafast switching, nonlinear fiber optics, and photonic device development.
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Abstract Number: ANPA2025-N00027 Presenting Author: Surya Gnyawali (Invited) Co-Authors: nan Presenter's Affiliation: McGowan Institute of Regenerative Medicine, University of Pittsburgh, USA Title: Imaging Technologies: Application to Wound Care Innovation Location: In-Person Presentation, Fairmont Show/Hide Abstract My laboratory has published magnetic resonance imaging (11.7 T) studies demonstrating secondary myocyte death after ischemia/reperfusion (IR) of the murine heart and stroke. This work provides the first evidence from 11.7-T magnet-assisted pixel-level analysis of the post-IR murine myocardial infarct patches. Changes in the function of the remodeling heart were examined in tandem, IR compromised cardiac function and induced LV hypertrophy. During recovery, the IR-induced increase in LV mass was partly offset. IR-induced wall thinning was noted in the anterior aspect of LV and at the diametrically opposite end. Infarct size was observed to be largest on post-IR days 3 and 7. With time (day 28), however, the infarct size was significantly reduced. IR-induced absolute signal-intensity enhancement was highest on post-IR days 3 and 7. As a function of post-IR time, signal intensity enhancement was attenuated. The threshold of hyper-enhanced tissue delineated contours that identified necrotic and reversibly injured infarct patches. The study of infarct transmurality indicated that while the permanently injured tissue volume remained unchanged, part of the reversibly injured infarct patch recovered in 4 weeks after IR. The approach validated in the current study is powerful in noninvasively monitoring the remodeling of the post-IR murine myocardium. Besides cardiac study, we study acute ischemic strokes in murine and canine models. Some of the recently published studies will be discussed.
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Abstract Number: ANPA2025-N00032 Presenting Author: Arjun Ghimire Co-Authors: nan Presenter's Affiliation: Kent State University Title: Director-layer dynamics in the smectic-ZA phase of a ferroelectric nematic liquid crystal Location: In-Person Presentation, Fairmont Show/Hide Abstract Abstract
A dynamic light scattering study of director-layer fluctuations in the antiferroelectric smectic-ZA phase of the ferroelectric nematic liquid crystal DIO is reported. The dynamics are consistent with the distictive feature of the ZA phase that the smectic layers form parallel to the axis of molecular orientational order (director). A model is developed to describe quantitatively the dispersion of the fluctuation relaxation rates. The model is based on a specialization of the elastic free energy density of smectic -C phase to the case of 90° director tilt ,a “first-order approximation of the viscous stresses by their form for an incompressible uniaxial fluid, and a treatment of the effect of chevron layer structure that develops in planar cells due to temperature-dependent layer shrinkage, as documented in previous studies on DIO. From the modeling, the layer compression elastic constant is estimated to be ~100 times lower in the smectic-ZA phase than in an ordinary smectic-A liquid crystal. Possible effects of the antiferroelectric layer polarization on the director splay elasticity and viscosity are described. The temperature dependancies of the splay, twist and bend elastic constants and associated viscosities in the higher temperature nematic phase are also presented.
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Abstract Number: ANPA2025-N00033 Presenting Author: Ganga Sharma Co-Authors: nan Presenter's Affiliation: Fairmont State University Title: Deep Learning for Personalized Dose Prediction and Optimization in Radiation Therapy for Cancer Treatment Location: In-Person Presentation, Fairmont Show/Hide Abstract Radiation therapy is a cornerstone in the treatment of various cancers. Achieving the optimal therapeutic dose while minimizing damage to healthy tissues remains a significant clinical challenge. This work explores integrating deep learning techniques into personalized dose prediction and optimization workflows for radiation therapy. Deep neural networks can model complex spatial dose distributions with high precision. We demonstrate how convolutional neural networks (CNNs) can be trained to predict optimal dose maps tailored to individual patients. Furthermore, we explore how reinforcement learning and optimization algorithms can refine treatment plans in real time, ensuring compliance with clinical constraints and maximizing tumor control probability.
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Abstract Number: ANPA2025-N00034 Presenting Author: Manisha Badu Co-Authors: nan Presenter's Affiliation: Kent State University Title: Thiophene containing ferroelectric nematic liquid crystals with one third of molecular length layering Location: In-Person Presentation, Fairmont Show/Hide Abstract A group of highly polar rod like molecules each consisting of three rings and ending with thiophene group has been synthesized and their physical behavior has been throughly examined for selected few. On cooling from the isotropic fluid they directly transition to ferroelectric nematic liquid crystal showing strong spatial correlation corresponding to 1/3 of molecular length. Compound with thiophene ring exhibit polarization values that are roughly 20% higher than those of typical ferroelectric nematic liquid crystals . The enhanced polarization is linked to their denser molecular structure.
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Abstract Number: ANPA2025-N00035 Presenting Author: Kamal Rai Co-Authors: Qian Wang Presenter's Affiliation: West Virginia University Title: Proton Transfer via Arginine with Suppressed pKa Mediates Catalysis by Gentisate and Salicylate Dioxygenase Location: In-Person Presentation, Fairmont Show/Hide Abstract Gentisate and salicylate 1,2-dioxygenases (GDO and SDO) facilitate aerobic degradation of aromatic rings by inserting both atoms of dioxygen into their substrates, thereby participating in global carbon cycling. The role of acid–base catalysts in the reaction cycles of these enzymes is debatable. We present evidence of the participation of a proton shuffler during catalysis by GDO and SDO. The pH dependence of Michaelis–Menten parameters demonstrates that a single proton transfer is mandatory for the catalysis. Measurements at variable temperatures and pHs were used to determine the standard enthalpy of ionization (ΔHion°) of 51 kJ/mol for the proton transfer event. Although the observed apparent pKa in the range of 6.0–7.0 for substrates of both enzymes is highly suggestive of a histidine residue, ΔHion° establishes an arginine residue as the likely proton source, providing phylogenetic relevance for this strictly conserved residue in the GDO family. We propose that the atypical 3-histidine ferrous binding scaffold of GDOs contributes to the suppression of arginine pKa and provides support for this argument by employing a 2-histidine-1-carboxylate variant of the enzyme that exhibits elevated pKa. A reaction mechanism considering the role of the proton source in stabilizing key reaction intermediates is proposed.
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Abstract Number: ANPA2025-N00037 Presenting Author: Emmanuel Cortez Ruiz Co-Authors: Ganga P. Sharma Presenter's Affiliation: Fairmont State University Title: Integrating Artificial Intelligence to Quantify and Exploit the Oxygen Effect in Radiation Therapy for Cancer Treatment Location: In-Person Presentation, Fairmont Show/Hide Abstract The efficacy of radiation therapy in cancer treatment is significantly influenced by the oxygenation status of tumor tissues, a phenomenon known as the "oxygen effect," where well-oxygenated cells exhibit greater radiosensitivity compared to hypoxic cells. This spatial and temporal heterogeneity in tumor oxygenation poses a major challenge to treatment optimization. Recent advances in artificial intelligence (AI) offer promising tools to analyze complex biological data and improve precision in radiotherapy planning. This presentation explores the integration of AI-based models with functional imaging and clinical datasets to dynamically assess tumor oxygenation and predict treatment response. By leveraging deep learning algorithms and radiomics, AI can identify hypoxic regions, adapt dose distributions accordingly, and personalize treatment protocols to enhance therapeutic outcomes. The convergence of AI and oxygen biology opens a new frontier in radiation oncology, potentially overcoming radioresistance and improving prognosis for patients with solid tumors.
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Abstract Number: ANPA2025-N0006 Presenting Author: Poshan Belbase Co-Authors: Dr. Gangkai Poh; Dr. Gaun Le; Dr. Xochitl Blanco Cano; Dr. Yuxi Chen Presenter's Affiliation: Catholic University Of America Title: Unveiling the Nature of 3-Second ULF Waves in Earth’s Foreshock Region Location: In-Person Presentation, Fairmont Show/Hide Abstract Ultra-low frequency (ULF) waves, typically ranging from ~1 mHz to 1 Hz in magnetospheric physics, play a vital role in space plasma dynamics, especially in the Earth's foreshock region upstream of the bow shock. Among them, a class of ULF waves with a period of approximately 3 seconds has garnered growing interest due to their distinguished characteristics and largely unexplored generation mechanisms. First detected in ISEE magnetometer data, these waves are typically right-hand polarized, nearly circular in the spacecraft frame, and occur in high plasma beta environments, where thermal pressure dominates over magnetic pressure. These waves can exist in different regions of the foreshock where other waves can also exist. When 3-second waves appear in regions with a stable magnetic field, they are typically accompanied by ion beams reflected from the Earth’s bow shock, whereas in areas with a more irregular magnetic background, the associated ion distributions tend to be more isotropic. These waves are also sometimes observed to be superimposed on lower frequency waves with a wave period of ~30-second.
Our study conducts a comprehensive statistical analysis of ULF waves with a time period around 3 seconds (frequency ~ 2-4 HZ) using 10 years of MMS field and particle data. We identified wave events using spectral wavelet analysis technique and minimum variance analysis on the magnetic field measurements to determine the wave frequency and polarization. Multi-spacecraft timing methods are employed to derive the wave propagation directions and its phase velocity in the plasma rest frame. We also analyzed the high resolution ion velocity distribution functions to characterize the suprathermal (i.e. particles with energies higher than the energies of solar wind particles) ion population during these 3-s wave events, which are then used as inputs for the wave dispersion solver to identify the plasma instability responsible for generating these plasma waves.
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Abstract Number: ANPA2025-N00077 Presenting Author: Sabin Thapa Co-Authors: Ramona Vogt, Michael Strickland Presenter's Affiliation: Kent State University Title: Quarkonia as the Probe of QGP formation in High Energy Collisions Location: In-Person Presentation, Fairmont Show/Hide Abstract High-energy heavy-ion collisions at RHIC and the LHC recreate the Quark–Gluon Plasma (QGP), a deconfined state of matter present moments after the Big Bang. Heavy quarkonia — bound charm–anticharm or bottom–antibottom pairs — serve as excellent probes of the QGP medium. Quarkonia yields in such collisions are suppressed relative to proton–proton baselines due to both cold nuclear matter effects and modifications due to the interaction with the hot QGP medium. To better understand this exotic QCD state, we have to disentangle different nuclear contributions, for which we have developed a unified framework that incorporates both cold and hot nuclear matter effects, with background QGP evolution simulated using relativistic anisotropic hydrodynamics. Within this evolving medium, bottomonium suppression is computed using two complementary approaches: an openâ€quantumâ€system treatment based on pNRQCD, and a semiâ€classical rate equation with recent reaction rates. Combining all these effects, we compute the nuclear modification factor $R^\Upsilon(y,p_T)$ for different bottomoia states, comparing our results with experimental data and providing predictions for future measurements.
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Abstract Number: ANPA2025-N00085 Presenting Author: Umesh Silwal Co-Authors: Richard A. Dudley and Farida Mohiuddin-Jacobs Presenter's Affiliation: University of North Carolina at Charlotte Title: Transforming Online Physics Lab Courses into Hands-On At-Home (HOAH) Labs Location: In-Person Presentation, Fairmont Show/Hide Abstract We have developed a Hands-On At-Home (HOAH) Lab for introductory physics courses, enabling students to perform real experiments at home using specially designed lab kits. Most online lab courses, which rely on simulations, limit hands-on learning and are often not accepted by professional programs such as medical schools. Our HOAH Lab significantly reduced the simulation component and offers fully practical, lab-based experience beyond the traditional lab room. This approach maintains academic rigor while addressing high enrollment in the in-person labs and offering greater flexibility for working students and commuters who face challenges attending long weekday lab sessions. The HOAH Lab incurs no additional cost for students, as the lab kit price is roughly equivalent to the traditional lab book. In-person students are required to purchase a lab book, while electronic copies of the at-home lab exercises are freely accessible for these participants. This talk will present how our HOAH Lab can foster accessibility, engagement, and improve the overall learning experience for our introductory-level undergraduate students.
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Abstract Number: ANPA2025-N00088 Presenting Author: Shruti Shrestha Co-Authors: nan Presenter's Affiliation: Penn State Brandywine Title: Fostering Inclusiveness in Physics for Undergraduate Women Location: In-Person Presentation, Fairmont Show/Hide Abstract Abstract: Despite the notable increase in the percentage of Bachelor's degrees awarded to women in STEM fields in the United States—from 17% in 1966 to 41% in 2021, as reported by the American Physical Society, the rate of growth of women in physics remains low. This trend is also observed in Nepal.
Studies on diversity, equity, and inclusion in physics learning environments reveal significant gender disparities in introductory physics and mathematics courses. Such disparities adversely affect young women's decisions to pursue degrees in physics.
To address this gap, physics education should incorporate instructional practices proven effective in other STEM fields. These include practices like active learning and inclusive strategies, collaborative learning, peer instruction, and formative assessments.
These methods support historically marginalized students and contribute positively to the learning experience in physics education. This presentation will provide a detailed analysis of these strategies and their practical applications for an inclusive future in physics.
These methods support historically marginalized students and contribute positively to the learning experience in physics education.
Keywords: Inclusion, Instructional Strategies, Women, Minority Groups
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Abstract Number: ANPA2025-N00089 Presenting Author: Rudra Kafle Co-Authors: nan Presenter's Affiliation: Worcester Polytechnic Institute Title: Technology-Assisted Grading of Written Assignments in Large Classes Location: In-Person Presentation, Fairmont Show/Hide Abstract High-quality instruction involves actively engaging students through effective pedagogy, regularly assessing their learning, and providing timely feedback on their work. One common method of assessment is through assignments and exams. However, in large-enrollment classes, grading and delivering feedback can be time-consuming and labor-intensive. Today, a variety of educational technology tools are available to streamline this process and enhance its efficiency. In this presentation, I will share my recent experience using Gradescope to grade exams in large-enrollment courses.
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Central Department of Physics Schedule
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Abstract Number: ANPA2025-N00041 Presenting Author: Yuwaraj K. Kshetri (Invited) Co-Authors: nan Presenter's Affiliation: Sun Moon University, Republic of Korea Title: Neutron Diffraction and Electronic Structure Investigation of Er-α-SiAlON for High-Temperature Sensing Location: In-Person Presentation, CDP Show/Hide Abstract α-SiAlON ceramics have been in use as engineering ceramics in the most arduous industrial environments such as molten metal handling, cutting tools, gas turbine engines, extrusion molds, thermocouple sheaths, protective cover for high-temperature sensors, etc., owing to their outstanding mechanical, thermal, and chemical stability. Taking advantage of the intrinsic properties of α-SiAlONs, we investigate the possibility of using the Er-doped α-SiAlON (Er-α-SiAlON) ceramic as a high-temperature sensing material via its unique near-infrared to visible upconversion property. We first use neutron diffraction and density functional theory calculations to study the electronic structure and thermodynamic stability of Er-α-SiAlON. Neutron diffraction is particularly essential in this study, as X-ray diffraction alone cannot precisely determine the atomic positions due to the similar X-ray scattering cross-sections of oxygen (O) and nitrogen (N) atoms. In contrast, neutron diffraction provides significantly different scattering cross-sections for O and N, enabling accurate crystal structure identification of SiAlON ceramics. It is found that the interstitial doping of Er stabilizes the α-SiAlON structure via chemical bonds with O-atoms with an N:O ratio of 5:2 in the seven-fold coordination sites of the Er3+ ion. Temperature-dependent upconversion emissions are then studied under 980 and 793 nm excitations over a temperature range of 298–1373 K, and the fluorescence intensity ratio (FIR) technique has been employed to investigate the temperature sensing behavior. Temperature-dependent Raman behavior is also investigated. We demonstrate that using Er-α-SiAlON as a sensing material, the limit of temperature measurement via the FIR technique can be pushed well beyond 1200 K.
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Abstract Number: ANPA2025-N0009 Presenting Author: Madhu Sudan Paudel Co-Authors: Basu Dev Ghimire; Narayan Prasad Chapagain Presenter's Affiliation: Central Department of Physics, IoST, TU, Nepal Title: Seismo-Ionospheric Coupling of Two Shallow and Moderate Earthquakes (M6.4) in Indonesia in 2024 Observed via TEC Analysis Location: In-Person Presentation, CDP Show/Hide Abstract Abstract
This study investigates seismo-ionospheric coupling phenomena associated with two moderate earthquakes (Mw 6.4) that occurred in Indonesia in 2024. The first event took place on March 22 near Paciran (5.875°S, 112.365°E) at a depth of 9.5 km, and the second on April 9 near Tobelo (2.698°N, 127.062°E) at a depth of 22.0 km. Ionospheric Total Electron Content (TEC) variations were analyzed using GNSS data from permanent ground stations BNOA and BTNG, provided by UNAVCO. A running-quartile method was applied to determine the upper and lower bounds of TEC variations. For the Paciran earthquake, anomalous TEC signals were detected 4–20 days prior to the event. Similarly, for the Tobelo earthquake, anomalies were observed 13–14 days before the event. To validate these findings, Global Ionospheric Map (GIM) data from the International GNSS Service (IGS) were examined, which revealed enhanced TEC over the respective epicentral regions on the identified anomalous days. The study discusses possible physical mechanisms responsible for these pre-seismic ionospheric perturbations.
Keywords: Seismo-ionospheric coupling, Total Electron Content, GNSS, ionospheric anomalies, Mw 6.4 earthquake, Indonesia
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Abstract Number: ANPA2025-N00015 Presenting Author: Bablu Kant Thakur Co-Authors: Dr. Lekha Nath Mishra; Dr. Rajendra Shrestha; Arun Kumar Shah; Ram Lal Shah Presenter's Affiliation: Tribhuvan University - Trichandra Multiple Campus, Physics Title: Impact of APPJ on Swiss Chard Seed Location: In-Person Presentation, CDP Show/Hide Abstract The atmospheric pressure plasma jet is generated with quartz glass tube of external diameter 5 mm and internal diameter 3 mm. Argon gas is used as working gas. The plasma jet has been characterized with measurement of electron density and electron temperature by electrical and optical method. The plasma jet is exposed on Swiss Chard seed. The germination percentage of Swiss Chard was found to be increased.
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Abstract Number: ANPA2025-N00020 Presenting Author: Saddam Husian Dhobi Co-Authors: Saddam Husain Dhobi; Surendra Hangsarumba; Raman Kumar Kamat;, Jeevan Jyoti Nakarmi; Kishori Yadav; Suresh Prasad Gupta; Ajay kumar Jha Presenter's Affiliation: Tribhuvan University Title: Thermal and Laser Field Driven PEMFC as Electron and Proton Sensing with Hydrogen Sources Location: In-Person Presentation, CDP Show/Hide Abstract This study explores a thermal and laser field-driven Proton Exchange Membrane Fuel Cell (PEMFC), focusing on surface scattering effects that lead to the formation of electrons and protons from hydrogen molecules. The system functions as a dual electron-proton sensor, enabling the detection of hydrogen sources through charge carrier interactions at the PEMFC surface. The primary objective is to examine the relationship between the differential cross-section (DCS) and the output voltage of the PEMFC, both theoretically and experimentally. A theoretical model was first developed using the thermal Volkov wave function, Kroll-Watson approximation, Bessel function and the first-Born approximation to analyze DCS behavior with respect to temperature. The results suggest that DCS increases with temperature, indicating greater electron separation and a corresponding decrease in the electric field and output voltage. To validate this model, a PEMFC prototype was designed and fabricated. Experimental findings revealed that applying a laser field increased voltage, while thermal input alone reduced it. However, the combined application of laser and thermal fields resulted in maximum voltage output. These observations suggest that higher voltage corresponds to stronger electric fields and closer electron interaction implying lower DCS while reduced voltage reflects weaker fields and dispersed electron interactions at the PEMFC surface.
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Abstract Number: ANPA2025-N00036 Presenting Author: Dharma Raj Paudel Co-Authors: nan Presenter's Affiliation: Central Department of Physics, T.U. Title: In Silico Identification of Natural Product Inhibitors Targeting SARS-CoV-2 Mpro Location: In-Person Presentation, CDP Show/Hide Abstract In Silico Identification of Natural Product Inhibitors Targeting SARS-CoV-2 Mpro
Dharma Raj Paudel1, Aashish Pokhrel2, Pooja Shrestha2, Saran Lamichhane1, Rajendra Prasad Koirala1, Indra Dev Sahu3, Pramod Aryal2, Narayan Prasad Adhikari1
1Central Department of Physics , Tribhuvan University
2Central Department of Biotechnology, Tribhuvan University
3Campbellsville University, United States of America
The COVID-19 pandemic, triggered by the highly transmissible SARS-CoV-2 virus, has had a profound and unparalleled effect on modern society, disrupting public health systems, economies, education, and cultural life. A single drug or vaccine may not be sufficient to counter emerging variants of the virus. Additionally, the complexity and side effects linked to earlier vaccines have contributed to ongoing hesitancy among certain groups. Mpro is a vital coronavirus enzyme responsible for viral replication and transcription, making it a prime target for SARS-CoV-2 drug development. In this study, the crystal structure of Mpro (PDB id: 6LU7) was utilized, and ligands from the ZINC database, identified as natural products, were screened for drugability using Lipinski rule of 5. Subsequent screenings involved targeting h-MAT1A and CYP3a4 proteins. Further screening was carried out as target protein docking and phase-1 drug clearances. The best ligands according to the docking score were selected. The selected ligands were further examined using density functional theory and molecular dynamics simulations for validation as potential drug candidates. Molecular dynamics simulations confirmed that the selected ligands exhibit considerable stability and establish numerous hydrogen bonds with the protein. Both DFT analysis and MD simulations indicate that the proposed ligands are promising as Mpro inhibitors and warrant further evaluation, including clinical trials.
Key Words : Virtual screening , Natural products, Mpro protein inhibitors, h-MAT1A , density functional theory, Molecular dynamics simulation
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Abstract Number: ANPA2025-N00048 Presenting Author: Bed Prasad Pandey Co-Authors: Santosh Kumar Pandit; Sanju Shrestha; Om Prakash Niraula; Kavindra Kumar Kavi Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kathmandu, Nepal Title: Performance Optimization of Triple-Metal High-K Dielectric Double-Gate Tunnel Field-Effect Transistor (TFET) for Enhanced Tunneling Characteristics Location: In-Person Presentation, CDP Show/Hide Abstract Vertical Tunnel Field Effect Transistor (VTFET) is being studied, because of its extremely low of sub-threshold swing (SS) and higher current ON-OFF ratio. Hence, various physical parameters and the performances of the optimal designed the Triple Metal High-K Dielectric Double Gate Vertical Tunnel Field Effect Transistor (VTFET), prepared by using 2D simulator using HfO2 / SiO2 as a gate dielectric and substrates are investigated. The calculated I_(on )/I_off ratio and the SS are found to be 1.85x 10^13 and 15.89 mV/decade. The higher value of the current ratio and the lower SS made its application as a fast switching and low power consumable device. The studies of analog parameters such as input and output capacitances and cutoff frequencies makes its applications in many analog and digital low power applications also.
Keywords: High-K dielectric, sub-threshold swing, vertical field effect transistor, fast switching, low power consumable device.
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Abstract Number: ANPA2025-N00061 Presenting Author: Pramod Kumar Thakur Co-Authors: Gopi Chandra Kaphle; Hari Prasad Lamichhane; Hari Shankar Mallik Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kirtipur, Kathmandu Title: Stabilities, properties and applications of Janus TaSeS 2D monolayer material Location: In-Person Presentation, CDP Show/Hide Abstract Janus 2D transition-metal dichalcogenide TaSeS monolayer exhibits a stable hexagonal crystal structure with lattice parameter 6.35 Ã… and negative values of cohesive and formation energies and positive distribution of frequencies obtained from phonon dispersion relation within the brillouin zone limit confirm its chemical and dynamical stability. All the calculations were performed through density functional theory based full potential plane-wave code within the generalized gradient approximation (GGA). The mechanical properties show its stability which is varied with the uniaxial and biaxial strain for elastic to plastic variation of the material. The electronic, magnetic, thermal and optical properties of the material show its prosing applications in the field of piezoelectric devices, field-effect transistors (FETs), optoelectronics, and spintronics devices.
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Abstract Number: ANPA2025-N00060 Presenting Author: Krishna Prasad Chapai Co-Authors: Durga Paudyal Presenter's Affiliation: Mid-West University,Surkhet,Nepal Title: Structural and Electronic Properties in Doped VCl3 Monolayer : A Density Functional Study Location: In-Person Presentation, CDP Show/Hide Abstract Two dimensional transition metal trihalides are van dar Waals (vdW) crystal which are becoming field of interest due to their intrinsic ferromagnetism and anisotropic feature down to monolayer limit. The exfoliated 3d-transition metal trihalides from its bulk counterpart has got immense interest due to its peculiar properties useful for the spintronic and memory storage applications. We report the exciting properties for pristine and 3d-TM doped VCl3 layered materials using density functional theory approach. The pristine VCl3 monolayer is found to be stable in P3 structure whose chemical stability is confirmed by negative value of cohesive and formation energy. The pristine and 3d -TM ( Cr, Ti ) doped VCl3 are found to be ferromagnetically stable in ground state. We found 2D-VCl3 as intrinsic Dirac Half Metal (DHM) in one spin channel which is immensely useful for spin current generation. Our result reveals that doping of 3d-TM ( Cr,Ti) on pristine VCl3 affects electronic and magnetic properties by altering electronic structure from DHM to semiconducting or half metallic state. The study highlights the doped structure possessing the tunable band gap at monolayer scale and its potential application for spintronics through dopant engineering.
Keywords: 2D transition metal trihalides, anisotropy, electronic properties, Dirac Half Metal, Spintronics.
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Abstract Number: ANPA2025-N00075 Presenting Author: Karishma Rana Co-Authors: nan Presenter's Affiliation: Amrit Campus, Tribhuvan University Title: STUDY OF VARIATION OF ACTIVITY CONCENTRATION OF 226-Ra, 232-Th AND 40-K AND THE RADIOLOGICAL PARAMETERS THROUGH RADIOMETRIC SURVEY FROM SETIBENI TO PURTIGHAT Location: In-Person Presentation, CDP Show/Hide Abstract We have studied terrestrial radioactivity due to naturally occurring radioactive materials (NORMS) 226-Ra, 232-Th, and 40-K and some radiological parameters using the portable gamma-ray spectrometer (PGIS-2) from Setibeni to Purtighat, Nepal via the Kaligandaki corridor. The activity concentrations of 226-Ra, 232-Th, and 40-K were found to be 1202.02 Bq/kg, 91.64 Bq/kg, 83.20 Bq/kg respectively. The absorbed dose rate was found to be143.08 nGy/h, the internal hazard index was 1.07, the annual effective dose equivalent value was 0.18 mSv/year, and the excess lifetime cancer risk factor was 0.62. The result indicated that despite the higher activity concentration of 226-Ra, 232-Th, and 40-K, the study area is non-hazardous and the materials are safe to use in construction. This could be due to the high concentrations of radionuclides on the bank of the Kaligandagi River. The correlation of dose rate with the activity concentrations of 226-Ra, 40-K, and 232-Th were also plotted separately
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Abstract Number: ANPA2025-N00025 Presenting Author: Abdul Klam Khan Co-Authors: nan Presenter's Affiliation: Central Department of Physics, Tribhuvan University Title: EFFECT OF PLASMA ACTIVATED WATER IN THE YIELD OF OYSTER MUSHROOM Location: In-Person Presentation, CDP Show/Hide Abstract In this study, plasma-activated water (PAW) produced using gliding arc discharge plasma was used to observe its effect on the budding and growth of oyster mushrooms. The activation of de-ionised water by plasma causes significant changes in the physical and chemical properties of PAW. With the increase in treatment time of the water, the pH of the water decreased, while the electrical conductivity, oxidation-reduction potential, total dissolved solids, and the levels of nitrate and nitrite increased. PAW showed a strong effect on the budding and production of oyster mushrooms. Notably, when 20-minute treated PAW was used, the seeds budded faster, and the production yield was higher. These results suggest that plasma-activated water can be an effective method to enhance the cultivation of oyster mushrooms.
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Abstract Number: ANPA2025-N00024 Presenting Author: Ramesh Khanal Co-Authors: Dr. Suresh Basnet; Prof. Raju Khanal Presenter's Affiliation: Student Title: Magnetized Plasma-Wall Interaction Mechanism in the Presence of Secondary Electron Emission Relevant to Fusion Devices Location: In-Person Presentation, CDP Show/Hide Abstract Understanding plasma-wall interactions is crucial for improving the performance, lifetime, and
stability of magnetically confined fusion devices. This study employs a kinetic trajectory
simulation method to investigate the plasma-wall interaction (where the surfaces are tungsten,
carbon, and molybdenum) in the presence of secondary electron emission, energy-dependent
sputtering effects, self-consistent electric fields, and oblique magnetic fields. The model is
constrained to a 1D3V, time-independent, collisionless framework. Particle distribution functions
at the injection plane are assumed to be cut-off Maxwellians. Ion distribution functions are
obtained by tracing exact trajectories in phase space, while electron and emitted electron
densities are analytically obtained. Key plasma-wall transition conditions; quasineutrality,
sheath-edge singularity, continuity of macroscopic fluid parameters, and the Bohm sheath
criterion are satisfied, with a presheath-sheath coupling applied for smooth transition between
presheath-sheath boundary. The Bohm sheath condition is extended to multi-component plasmas
with cut-off distributions of emitted electrons. Simulations reveal that emitted electrons
substantially modify the potential profile, flattening the potential drop and introducing non-
monotonic structures. In oblique magnetic fields, the Bohm velocity for ions decreases with field
angle, reflecting stronger field-aligned motion requirements, while strong electron emission
lowers these velocity thresholds by weakening the sheath potential. Regarding material erosion,
tungsten shows the lowest sputtering yields than that of molybdenum, and carbon surfaces,
emphasizing the critical role of material selection in plasma-facing component design for fusion
devices.
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Abstract Number: ANPA2025-N00023 Presenting Author: Saroj Pandeya Co-Authors: Suresh Basnet; Raju Khanal Presenter's Affiliation: Tribhuvan University Title: Oblique Propagation of Ion-Acoustic Solitary Waves in 3D3V Magnetized Quantum Plasma with Anisotropic Electron and Ion Pressures. Location: In-Person Presentation, CDP Show/Hide Abstract Quantum ion-acoustic solitary waves (QIASWs) are studied in dense astrophysical environments, and collisional laboratory plasmas employing a quantum hydrodynamic model with anisotropic temperatures, constant magnetic field along z-axis, and the Bohm potential gradient to examine the formation and evolution of QIASWs. Anisotropic equation of state with degeneracy (relativistic and non-relativistic) for white dwarf plasma, and double adiabatic approximation for laboratory collisional plasma are applied in polytropic form in two-fluid momentum transport equations. Effect of weak magnetization on solitary vortical structures is also studied in fermi plasma. Hydrodynamic approximation is ensured for each plasma by satisfying conditions involving the mean free path, quantum plasma Debye length, and characteristic plasma length and time scales. Using the multiscale reductive perturbation technique with distinct ion, electron and potential expansion parameter, we derived the Korteweg–de Vries (KdV), dissipative KdV, and modified KdV (mKdV) equations, balancing of nonlinearity and dispersive effects, and compared with previous studies. The phase velocity of a solitary wave was found to be decreasing with obliqueness, independent of stretching and perturbation parameters, but depended on equilibrium pressures along the direction of the magnetic field, equilibrium density of species, and dust charge. The effect of viscous forces contributes to the damping of solitary waves leading to continuously decreased amplitude and increased width along stretched spacetime coordinates in laboratory plasma. Increasing magnetic field was found to increase amplitude and compress width of refractive as well as compressive solitary structures in each plasma at different cases i.e. T_(∥ ) >T_⊥, T_(∥ )=T_⊥, and T_(∥ ) |
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Abstract Number: ANPA2025-N00017 Presenting Author: Raman Kumar Kamat Co-Authors: Raman Kumar Kamat, Surendra Hangsarumba, Kishori Yadava, Suresh Prasad Gupta, Prakash M. Shrestha, Saddam Husain Dhobi Presenter's Affiliation: Department of Physics, Patan Multiple Campus, Tribhuvan University, Patan Dhoka, Lalitpur-44700, Nepal Title: Optical Characterization of Carbon Quantum Dots Under Laser and Magnetic Field Treatments Location: In-Person Presentation, CDP Show/Hide Abstract This study explores the influence of external treatments laser and magnetic field on the optical behavior of carbon quantum dots (CQDs) at varying concentrations. The approach aims to enhance understanding of how such treatments can modulate CQDs’ optical properties for advanced photonic and sensing applications. This study investigates the optical transmittance of CQDs at various concentrations (100%, 50%, 25%, and 12.5%) under different conditions, including laser and magnetic field treatments, all conducted at room temperature. CQDs were synthesized via a microwave-assisted method by mixing 0.2 g of thiourea and 0.4 g of citric acid, heated at 165 °C for 2 minutes. The heating product was dispersed in 40 mL of distilled water, followed by sonication and centrifugation. The optical properties were evaluated using a Theremino spectrometer, while CQDs confirmation was conducted by observing the fluorescence response under UV light after dropping into distilled water. The results demonstrated that the optical intensity was lowest at 100% concentration and gradually increases with dilution, reaching the lowest intensity at 12.5% diluted. For the 50% CQDs solution, samples were treated with a 100 mW laser and a 0.20 T magnetic field for 4 minutes. Compared to the untreated sample, the laser-treated CQDs showed increased intensity, whereas magnetic field treatment resulted in reduced intensity. Additionally, refractive index measurements using a rotating spectrometer revealed values of 1.340± 0.01 for the untreated 50% diluted sample, 1.350± 0.01 after laser treatment, and approximately 1.360 ± 0.01 after magnetic field treatment. These findings indicate that both treatments significantly influence the optical behavior and refractive index of CQDs.
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Abstract Number: ANPA2025-N00073 Presenting Author: Abhinav Pokharel Co-Authors: Rupisha Dangol Presenter's Affiliation: Tribhuvan University (Amrit Science Campus) Title: Quantum Key Distribution Using BB84 Protocol: A Computational Study of Error Rates Location: In-Person Presentation, CDP Show/Hide Abstract Quantum key distribution (QKD) enables a secure communication between two parties using the principles of Quantum Physics. The BB84 protocol, one of the first protocols in QKD, is effective not just for sharing keys but also for detecting eavesdropping. The paper simulated a computational model of QKD, analyzing error rates under varying conditions of the number of bits (n). Using Python-based simulation, this paper simulated key exchanges for n = 10, n = 100, n = 1000 bits. We also incorporated a 0.02 noise probability to simulate real–world conditions for both with and without eavesdropping. Each scenario was repeated over 1000 trials to obtain an average error rate. Our results show that, without eavesdropping, the average error rate remains close to 2 %, showcasing BB84’s stability against small noise. In the presence of an eavesdropper, the average error rate consistently exceeds 26%. Moreover, the standard deviation of error increases as n decreases, indicating higher variability in smaller datasets. While this study focuses on computational validation, the future work will extend towards building a low-cost experimental setup using basic optical tools.
Keywords: BB84 protocol, computational simulation, eavesdropping detection, noise modeling, QKD
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Abstract Number: ANPA2025-N00021 Presenting Author: Santosh Dhungana Co-Authors: Raju Khanal; Hom Bahadur Baniya Presenter's Affiliation: Tribhuvan Univesity Title: Physical and Chemical Profiling of Plasma-Activated Water Under Varying Treatment Conditions and Its Application in Plant Growth Location: In-Person Presentation, CDP Show/Hide Abstract Gliding arc discharge (GAD) system is a simple and inexpensive way to generate non-thermal plasma and has various applications in the fields of material processing, gas conversion, medical sterilization, and agriculture. In the field of agriculture, it can be used directly by treating seed and indirectly by preparing plasma activated water (PAW). Due to the presence of reactive oxygen and nitrogen species (RONS), it is considered a green fertilizer for seed germination and plant growth. In our work, GAD system was used to produce PAW and its physiochemical properties are examined under varying treatment conditions including treatment time, air flow rate, applied voltage and water volume. A significant change in physical (pH, electric conductivity (EC), oxidation reduction potential (ORP), total dissolved solid (TDS), salt, etc.) and chemical (concentration of nitrate, nitrite and hydrogen peroxide) properties of water are observed at different treatment conditions. Finally, the PAW is utilized to irrigate the newly germinated seedling of red cherry pepper chili (Akabare Khursani) in order to study its on growth.
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Abstract Number: ANPA2025-N00026 Presenting Author: Samjhana Dahal Co-Authors: Roshan Chalise, Raju Khanal Presenter's Affiliation: Student (Tribhuvan University) Title: Germination and Seedling Growth Enhancement Of Timur Seed (Zanthoxylum armatum) By Using Cold Atmospheric Pressure Plasma Location: In-Person Presentation, CDP Show/Hide Abstract Timur is a plant native to the Himalayan region and it is valued for its intense citrusy and peppery flavor, used in culinary and traditional practices. In this work, we have used gliding arc discharge for direct treatment of the Timur seed (Zanthoxylum armatum) and used plasma activated water, prepared by cylindrical dielectric barrier discharge and gliding arc discharge, to irrigate the plants, aiming to enhance germination and seedling growth. The plasma sources are characterized through electrical and optical characterization methods. From spectrometer, electron temperature of cylindrical dielectric barrier discharge and gliding arc discharge is found to be 1.41 eV and 1.66 eV with plasma density found to be 8.17 × 10 18 m −3 and 5.48 × 10 17 m −3 , respectively. Plasma treatment increases the
temperature, total dissolved solids, electrical conductivity, and oxidation-reduction potential of the plasma-activated water with the activation time; however, the potential of hydrogen decreases. In addition, it has been observed that nitrate concentration is notably higher than nitrite concentration. It has been observed that the direct application of plasma on Timur seeds results in changes to the seeds, particularly in their surface properties and wettability. The results showed that the wettability of seeds using two minutes (min) plasma-activated water increases the most compared to the untreated seeds and other treatment times. Although germination enhancement of the Timur seeds is not achieved in the laboratory condition, plasma-activated water positively impacts root and shoot growth, as well as
in the retention of chlorophyll content (or greenness) of leaves. A treatment time of four minutes using cylindrical dielectric barrier discharge and two minutes using plasma jet is found most favorable. The positive impact of plasma on Timur plants can be studied further to enhance germination, seedling growth, and ultimately, fruit yield, making it viable for agricultural applications in real field conditions.
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Abstract Number: ANPA2025-N0003 Presenting Author: Manjeet Kunwar Co-Authors: Nabin Bhusal ; Manil kathiwada; Niraj Dhital Presenter's Affiliation: Central Department of Physics ,TU Title: Optimize cosmological parameters to fit large-scale structure observations of dark matter distribution. Location: In-Person Presentation, CDP Show/Hide Abstract We optimize cosmological parameters to achieve the best fit between theoretical models and large-scale structure observations of dark matter distribution. Using constraints on the matter density parameter (Ωₘ) and the fluctuation amplitude (σ₈) from the Dark Energy Survey (DES) and the Planck mission, we refine parameter estimation within the ΛCDM framework. Additionally, we explore model extensions, including wCDM, massive neutrinos, and modified gravity, to improve consistency with observational data. To quantify potential tensions between DES and Planck results, we analyze the S₈ parameter, defined as S8=σ8Ωm/0.3S8​=σ8​Ωm​/0.3, to assess deviations and optimize cosmological fits.
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Abstract Number: ANPA2025-N00047 Presenting Author: Sandip Kumar Dangi Co-Authors: Sarita Regmi; Dinesh Kumar Chaudhary; Pitamber Shrestha Presenter's Affiliation: Amrit Campus, Lainchaur, Kathmandu Title: Electro-Chemical and Optical Characterization of SnO2 Film Location: In-Person Presentation, CDP Show/Hide Abstract Metal oxide thin films have gained considerable attention due to their diverse applications in agriculture, medicine, industry, and advanced technologies. Among these, SnOâ‚‚ thin films have emerged as promising materials for optoelectronic applications. In our study, SnOâ‚‚ thin films were synthesized on fluorine-doped tin oxide (FTO) substrates using a spin-coating technique, followed by annealing at 400°C to enhance crystallinity. The prepared samples were analyzed by various techniques such as FTIR spectroscopy, UV-Vis spectroscopy and Impedance spectroscopy. FTIR analysis confirmed the formation of the SnOâ‚‚ lattice with distinctive peaks at 516 cmâ»Â¹ and 754 cmâ»Â¹. UV–Vis revealed that optical transmittance decreased with increasing film thickness, while the optical band gap increased slightly from 3.45 eV to 3.55 eV. Concurrently, a decrease in Urbach energy from 0.2154 eV to 0.1619 eV suggested a reduction in defect density. The refractive index, determined via the Swanepoel method, stabilized at approximately 1.83, indicating enhanced densification and reduced porosity. Impedance spectrum showed that although the series resistance remained relatively constant, the charge transfer resistance increased and capacitance decreased with film thickness, indicating the critical role of film thickness in tuning the optical and electrical properties of SnOâ‚‚ thin films, paving the way for their optimized use in optoelectronic applications. Keywords: Tin oxide, Spin coating, Band-gap, Impedance spectrum, FTIR analysis.
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Abstract Number: ANPA2025-N00044 Presenting Author: Saroj Kafle Co-Authors: nan Presenter's Affiliation: Tribhuvan University Title: Investigation of optical and electrical properties of fluorine doped ZnO Thin films prepared by spray pyrolysis Location: In-Person Presentation, CDP Show/Hide Abstract This research project investigates the optical and electrical properties of fluorine-doped ZnO (F-
ZnO) thin films deposited on FTO-coated glass substrates using the spray pyrolysis technique.
ZnO films with a fluorine doping concentration of 15% were synthesized at approximately 400°C
from a 0.1 M precursor solution. Band gap energies decreased from 3.27 eV for undoped ZnO
to 3.15 eV for an 8-layer doped film, as determined using UV-Vis spectroscopy and Tauc plots.
Electrical characterization, performed using an LCR meter, revealed Nyquist plots with semicircular
patterns for all layers, indicating impedance behavior dominated by single relaxation processes. As
the number of layers increased from 2 to 8, bulk resistance (ð‘…2) consistently decreased (e.g., from
287.46 Ω for 2 layers to 76.61 Ω for 8 layers ), while capacitance (ð¶1) slightly increased, confirming
improved electrical conductivity. The equivalent circuit model extracted parameters, including ð‘…1,
ð‘…2 , and ð¶1, focusing on the efficient charge transport and storage properties of these films. These
results demonstrate that increasing the thickness of fluorine-doped ZnO films significantly enhances
their optical and electrical properties, making them highly suitable for applications such as solar
cells and sensors.
Keywords: ZnO thin film, Fluorine-doped ZnO, Spray pyrolysis, Nyquist plot, Optical band gap,
Electrical conductivity
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Abstract Number: ANPA2025-N00076 Presenting Author: Surendra Hangsarumba Co-Authors: Surendra Hangsarumba, Raman Kumar Kamat, Kishori Yadav, Suresh Prasad Gupta, Prakash M. Shrestha, Saddam Husain Dhobi Presenter's Affiliation: TU IoST, Patan Multiple Campus, Patandhoka,Lalitpur Title: Radiation Shielding Properties of Waste Materials Using a Geiger-Müller Counter and Different Radioactive Sources Location: In-Person Presentation, CDP Show/Hide Abstract Radiation shielding is a crucial safety measure used to reduce exposure to harmful ionizing radiation by using materials that absorb or block radiation. Effective shielding helps protect human health, equipment, and the environment in medical, industrial, and research settings. This study evaluates the shielding properties of waste materials plastic bottles, human hair, disposable medical gloves, and cardboard against three radioactive sources: Thallium (204Tl), Cesium (137Cs), and Strontium (90Sr), with present activities 0.05 µCi, 1.125 µCi, and 0.130 µCi, respectively. Samples of each material were prepared in solid form with dimensions 3 × 4 × 0.2 cm. Using a Geiger-Müller (GM) counter (Model No: TE Np 1, 220-230V, 50 Hz) at Patan Multiple Campus, radiation counts/minute were measured with the sample placed 6 cm from the source and 4 cm from the detector window, operated at 400 V. Without shielding, the counts/minutes recorded were 38 ± 3 counts/minute with 204Tl sources , 72± 4 counts/minute with 137Cs sources, and 182± 3 counts/minute with 90Sr sources. When shielded, the counts/minute observed for the 204Tl source were with plastic bottle is 32± 3 counts/minute, human hair is 6± 3 counts/minute, gloves is 6± 3 counts/minute, and cardboard is 30± 3 counts/minute; for the 137Cs source with plastic bottle is 58 counts/minute, human hair is 12± 3 counts/minute, gloves is 12± 3 counts/minute, and cardboard is 52± 3 counts/minute; and for the 90Sr source with plastic bottle is 180± 4 counts/minute, human hair is 20± 4 counts/minute, gloves is 26± 4 counts/minute, and cardboard is 132± 4 counts/minute. The background counts/minute without sources for all direction is 13 counts/minute. This indicate that human hair and gloves significantly reduced radiation counts compared to other materials, suggesting better shielding efficiency. These waste materials, due to their composition and effectiveness, could be utilized in developing low-cost radiation protection structures in areas with high radiation exposure.
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Abstract Number: ANPA2025-N00042 Presenting Author: Kaushal Pyakurel Co-Authors: Leela Pradhan Joshi Presenter's Affiliation: Central Department of Physics, TU Title: Synthesis and Electrochemical Performance of Activated Carbon from Lapsi Seed Biomass for Supercapacitor Application Location: In-Person Presentation, CDP Show/Hide Abstract The conversion of biomass waste into porous carbon for supercapacitor electrode application represents a promising
approach due to the low cost, abundance of raw materials, and environmental advantages. In this study, activated carbon(AC) was
synthesized from Lapsi (Choerospondias axillaris) seed biomass by chemical activation method with zinc chloride (ZnCl2) fol-
lowed by carbonization in the tubular furnace at 850 °C under continuous nitrogen flow of 100 cc/min for 4 hours. Electrochemical
characteristics of the AC electrode was studied in a three-electrode system with a potentiostat device through cyclic voltammetry
(CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The electrochemical parameters
such as specific capacitance, stability, and impedance are evaluated. The electrode exhibited a specific capacitance of 71.95 F/g
at a current density of 1 A/g and maintained 95.71% capacitance retention over 5000 cycles, demonstrating good electrochemical performance.
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Abstract Number: ANPA2025-N00062 Presenting Author: Ambika Shahi Co-Authors: nan Presenter's Affiliation: Central Department of Physics, Tribhuvan University Title: To investigate the Structural, Electronic and Magnetic properties of CrGa2S4 Location: In-Person Presentation, CDP Show/Hide Abstract Condensed matter physics, as a field, integrates various aspects of natural science, including theoretical, experimental, and computational approaches. It enables the exploration and understanding of novel materials across different length scales, from the atomic-microscopic levels to macroscopic phenomena. In this work, the Transition Metal (TM)-based ternary chalcogenide CrGa2S4 compound is a novel material that exhibits intriguing structural, electronic, and magnetic properties in both bulk and 1-structural layer, adopting an α-FeGa2S4-1T type phase. It crystallizes in the P-3m1 space group with lattice parameters a = 3.60 ˚A and c = 11.94 ˚A. First-principles calculations based on density functional theory were performed using the FPLO code with GGA, GGA+U, and GGA+SOC functionals. To achieve accurate band gap predictions, GGA+mBJ and GGA+mBJ+SOC were employed. The bulk structure exhibits a ferromagnetic ground state with half-metallic behavior, while the 1-structural layer undergoes a transition to a semiconducting state with an indirect band gap of 0.72 eV. The magnetocrystalline anisotropy energy calculations reveal an easy axis along [001] for the bulk and [100] for the 1-structural layer. This study emphasizes the phenomenal influence that dimensionality reduction on the electronic structure and offers insight into the tunability of electronic and magnetic characteristics. These findings pave the way for potential applications in electronic storage devices, particularly in spintronics.
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Abstract Number: ANPA2025-N00082 Presenting Author: Roshan Nepal Co-Authors: Anup Shrestha ; Anjan Dahal Presenter's Affiliation: Tribhuvan University Title: Detaction of metal oxidation states in halides using muon: a first-principle study Location: In-Person Presentation, CDP Show/Hide Abstract Metal oxidation states play an important role in determining the properties (magnetism, catalysis, ion conductivities, etc.) of wide varieties of materials. For example, in biology, O2 binding hemoglobin (oxyhemoglobin) contains Fe in ferrous states in its heme-group however the methemoglobin that cannot bind the O2 contains the ferric states of the Fe. From magnetic point of view, oxyhemoglobin shows diamagnetic nature however the methemoglobin shows the strong paramagnetic behavior. Since muon acts as a sensitive local probe, it can detect local electronic and dynamic states of materials. To understand the muon experimental data, computational technique, particularly density functional theory (DFT), is essential for revealing muon sites in the materials. Here we choose metal-halides with differing oxidation states (Fe2+ in FeCl2, Fe3+ in FeCl3, and Zn2+ in ZnCl2) to understand the behavior of muon in samples with different oxidation states. The FeCl₂ and FeCl₃ exhibit magnetic ordering [1], while the ZnCl₂ exhibits nonmagnetic [1]; consequently, the muon’s local stopping site, spin polarization, and electronic interactions vary among these compounds [2, 3]. We focus to identify and compare the muon sites and estimate its polarization in different oxidation states, and then investigate muon–metal interactions. In the program, the DFT result of muon behavior in FeCl2 and ZnCl2 will be presented.
References
[1] N. N. Greenwood, and A. Earnshaw, 2nd ed. (Chemistry of the Elements, Butterworth-Heinemann, 2012).
[2] I. J. Onuorah et. al., Phys. Rev. B, 97 (2018) 174414.
[3] S. J. Blundell and T. Lancaster, Appl. Phys. Rev. 10, (2023) 021303.
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Abstract Number: ANPA2025-N00084 Presenting Author: Anjan Dahal Co-Authors: Amba Datt Pant; Hari Shankar Mallik; Anjan Dahal; Akihiro Koda; Katshuhiko Ishida; Burkhard Geil; Jumpei Nakamura; Shoichiro Nishimura; Hiromi Sakai; Koichiro Shimomura Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kathmandu, Nepal Title: Understanding Muonium Anisotropy in Phosphate Buffered Saline: A ?SR Study Location: In-Person Presentation, CDP Show/Hide Abstract To establish the fundamentals of muon and muonium behavior in the biological system and its application in the cancer research, muon spin relaxation and rotation (?SR) experiments are conducted in water, buffer solutions, proteins, biomacromolecules and Hemoglobin. We have conducted experiment in several bio-samples and perform DFT calculations to support the experiments. This work focuses on ?SR experiment in phosphate-buffered saline (PBS) which is a biologically relevant medium often used in the medical applications and experimental biology. Muon is like a light proton (m?~1/9 mp) but with higher magnetic moment (??~3.2?p). When the positive muon implanted in a sample it captures an electron forms a hydrogen like atom called muonium (Mu). This light muonium acts as an ultra-sensitive probe, settling at reactive molecular sites to reveal detailed information about local electronic and magnetic environments of the sample. The experiment was performed in the temperature range of 140 K to 300 K under various low magnetic fields and muonium precession signal was observed. In the liquid state of PBS, an isotropic muonium along with a diamagnetic muon were observed. However, in frozen PBS, two distinct diamagnetic muon species and an axially symmetric anisotropic muonium like in frozen water were observed. In the program temperature dependent nature of the anisotropic muonium will be presented.
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Abstract Number: ANPA2025-N00059 Presenting Author: Bimala Debi Subedi Co-Authors: GAMBHIR KHAN THAKURI 7; LEELA PRADHAN JOSHI Presenter's Affiliation: Atmospheric and Material Science Research Centre, Amrit Campus, Tribhuvan University, Kathmandu, Nepal bDepartment of Physics, Prithvi Narayan Campus, Tribhuvan University, Pokhara, Nepal. Title: Electrochemical performance of activated carbon derived from waste wood of Alnus nepalensis for supercapacitor application Location: In-Person Presentation, CDP Show/Hide Abstract The growing demand for sustainable energy storage solutions has accelerated the development of advanced energy storage technologies. Traditional carbon materials sourced from fossil fuels present challenges such as high costs, complex processing, and potential environmental risks. In contrast, biomass-derived activated carbon has emerged as a highly promising alternative, offering advantages like natural abundance, high carbon content, and straightforward processing with minimal toxicity. This study outlines the production of activated carbon from waste wood of Alnus nepalensis through a series of processes, including activation using zinc chloride as the activating agent, followed by pre-carbonization and carbonization at 600°C in a tube furnace under a continuous flow of N₂ gas. The activated carbon was analyzed using various methods, including FTIR testing, while its electrochemical performance was evaluated through CV, GCD, EIS, and CV retention tests. These tests were conducted using a three-electrode arrangement with different reference electrodes (Hg/HgO, Ag/AgCl) and 6M KOH aqueous electrolyte solution. As a supercapacitor electrode material, AC exhibited a specific capacitance of 186.03 F/g at a current density of 1A/g, an energy density of 6.46 Wh/kg, and a power density of 124.99 W/kg. It demonstrated capacitance retention of 64.5% after 1,000 charge–discharge cycles at a current density of 1 A/g using an Hg/HgO reference electrode in a 6M KOH electrolyte. These results provide valuable insights into the development and electrochemical analysis of eco-friendly biomass-derived porous carbon, highlighting its potential as a supercapacitor electrode material.
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Abstract Number: ANPA2025-N00043 Presenting Author: Sarita Regmi Co-Authors: Sandip Kumar Dangi; Dinesh Kumar Chaudhary; Pitamber shrestha Presenter's Affiliation: Amrit Campus Title: OPTICAL AND ELECTROCHEMICAL PROPERTIES OF Co3O4 FILM Location: In-Person Presentation, CDP Show/Hide Abstract Cobalt oxide films have gained substantial research effort because of their electronic and optical properties in diverse fields, such as agriculture, industry, and energy storage. Herein, cobalt oxide (Co3O4) films on a fluorine-doped tin oxide glass substrate were synthesized by the spray pyrolysis technique and annealed in an air atmosphere at 350 ºC for 2 hours. The different layers of cobalt oxide films were prepared on an FTO-coated glass substrate, and the films formed were blackish-white. The prepared films were characterized using FTIR spectroscopy, UV-visible spectroscopy, and impedance spectroscopy. The FTIR spectra showed the two stretching bands Co(III)-O and Co(II)-O, which confirms the material composition of Co3O4. The optical measurements demonstrated that increasing the layers of cobalt oxide films, the band gap energy decreases. The thickest layer (Layer 9) showed the minimum band gap of about 2.21 eV. The impedance measurement was carried out from the high to low-frequency range, where the obtained impedance spectrum revealed enhanced conductivity and reduced grain boundary resistance with increasing film thickness, which may be due to increased mobility of charge carriers and reduced grain size. These results showed the tunable optical properties and enhanced charge transfer, highlighting the potential application for optoelectronic devices and supercapacitor applications.
Keywords: Cobalt oxide, Impedance, Thin film, Spray pyrolysis, Band gap
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Abstract Number: ANPA2025-N00010 Presenting Author: Anu Aryal Co-Authors: nan Presenter's Affiliation: Central Department of Physics, T.U Title: A study on quantum theory of consciousness to understand the very origin of mass. Location: In-Person Presentation, CDP Show/Hide Abstract There are many unsolved mysteries of the universe—such as its expansion, the debated nature of space-time, and the origin of the very first mass. The beauty of physics lies in the freedom that it offers researchers to explore these questions with creativity. One emerging field is the quantum theory of consciousness, which takes analytical, theoretical, mathematical, and philosophical approaches to understand the universe from a unique perspective. Quantum field theory, for instance, describes how different fields give rise to different particles—such as the Higgs boson arising from the Higgs field—providing insight into the origin of mass from the field itself. The study of the quantum theory of consciousness may offer a new lens through which to comprehend the nature of reality itself. This study is especially vital, as it not only seeks to explain the nature of reality but also considers the observer who perceives it. Since space-time forms the framework within which nearly all physical events occur, incorporating consciousness into this framework could deepen our understanding of existence. This kind of new study holds an enormous potentiality to unlock new perspectives on black holes, dark matter, and more.
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Abstract Number: ANPA2025-N00079 Presenting Author: Bal Vikram Khatri Co-Authors: Om Prakash Niraula; Himali Kalakhety; Raju Khanal Presenter's Affiliation: Tribhuvan University Title: In-Situ Radiometric Study Along the Kaligandaki River: Focus on the Deepest Gorge and Shaligram Fossils Location: In-Person Presentation, CDP Show/Hide Abstract An in-situ radiometric survey was conducted along the stretch of the Kaligandaki River in Nepal, a region of geological significance that features the world's deepest gorge and the presence of Shaligram fossilized ammonites, which hold both cultural and scientific importance. Kaligandaki River, one of major Rivers of Nepal, originates from Damodarkund close to Lomanthang, where deposit of Uranium have been confirmed by Department of Mines and Geology, Nepal. The famous fossilized stone Shaligram is also found only in this region. To carry out the study, we used the portable gamma-ray spectrometer PGIS-2, which is equipped with a NaI(Tl) detector. We determined radiological hazard parameters associated with the radionuclides, including radium equivalent activity, absorbed gamma dose rates in the air, annual effective dose rate, external hazard index, and internal hazard index. The results showed that 238U activity ranged from 55.17 Bq kg−1 to 125.63 Bq kg−1 with mean value 83.31 ± 19.49 Bq kg−1, 232Th activity ranged from 2.28 Bq kg−1 to 144.22 Bq kg−1 with mean value 61.55 ± 31.29 Bq kg−1 and 40K activity ranged from 92.48 Bq kg−1 to 1158.06 Bq kg−1 with mean value 631.44 ± 269.95 Bq kg−1. Mean values of the activities of all three radionuclides were found to be above the world average value. Radiological parameters like Raeq, ADR, Hex and Hin were found to be 219.95 ± 72.76 Bq kg−1, 102.18 ± 33.53 nGy hr-1 0.59 and 0.82 respectively. This study underscores the importance of continuous monitoring to ensure environmental and public safety in regions with naturally occurring radioactive materials.
Keywords: PGIS-2, Hazard index, Gamma dose rate, Radiation hazard
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Abstract Number: ANPA2025-N00080 Presenting Author: Devendra Raj Upadhyay Co-Authors: Orgin Tamang; Raju Khanal Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kathmandu, Nepal Title: Radiation Shielding and Transport Characeristics of Zinc Lithium Dysprosium Borotellurite Glasses Using Theoretical and Monte Carlo Code Location: In-Person Presentation, CDP Show/Hide Abstract The radiation shielding and dose attenuation capacity of six zinc-lithium-dysprosium borotellurite glass system having composition: (B2O3)0.2-(TeO2)0.3-x(ZnO)0.28–(Li2CO3)0.2– (Dy2O3)0.02-(WO3)x labeled as W1 to W6 for x value from 0.02 to 0.12 has been analysed. Shielding parameters like mass attenuation coefficient, linear attenuation coefficient, half value layer, tenth value layer, effective atomic number are estimated. Similarly, transport properties such as effective electron density, mean free path, effective conductivity have been analysed using Phy-X/PSD database in the energy range 1 keV to 100 GeV. Furthermore, fast neutron removal cross sections were calculated. The parameters like stopping potential and projected range of ions like proton, helium, and carbon in materials were calculated using Stopping and Range of Ions in Matter (SRIM) software package application. The trajectories and effective dose rate of photon was also evaluated using Particle and Heavy Ions Transport code System (PHITS). The obtained results show that sample W6(0.2B2-O3–0.3TeO2- 0.0336ZnO–0.2Li2CO3–0.02Dy2O3–0.12WO3) has better protective potential than rest five glass samples and comparable to other glasses that were previously studied and recommended for nuclear applications.
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Abstract Number: ANPA2025-N00081 Presenting Author: Ram Sharan Karki Co-Authors: nan Presenter's Affiliation: Tribhuvan University Title: Assessment of Uncertainty in Dose Measurement Using TLD-100 and Monte Carlo Methods Location: In-Person Presentation, CDP Show/Hide Abstract This study evaluates the uncertainties in radiation dose measurements using TLD-100 dosimeters (lithium fluoride crystal doped with magnesium and titanium and the Harshaw 6600 Plus TLD reader system) at the Nepal Academy of Science and Technology, Khumaltar, Nepal. LiF:Mg,Ti is widely used in thermoluminescent dosimetry due to its favorable properties, making it a preferred material for radiation monitoring in occupational, environmental, and medical contexts. The calibration of TLD-100 dosimeters and evaluation of uncertainties are done through both analytical and Monte Carlo approaches. The standard uncertainty of personal dose equivalent Hp(10) measurements, considering non-linear response, was found to be 0.123, with an expanded uncertainty of 0.164 mSv and a relative uncertainty of 16.122% (k = 1.96), while the combined relative uncertainty for generating calibration factors was 11.91%. When employing Monte Carlo methods, the standard uncertainty increased to 0.140, with an expanded uncertainty of 0.224 mSv and a relative uncertainty of 20.919%, resulting in a combined relative uncertainty of 13.46%. These results confirm that the dosimetry system meets international uncertainty standards, and the use of Monte Carlo methods contributes to improved accuracy in occupational dose assessments.
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Abstract Number: ANPA2025-N00078 Presenting Author: Num Prasad Acharya Co-Authors: Suresh Basnet; Amar Prasad Misra; Raju Khanal Presenter's Affiliation: Mr Title: DUST-ION-ACOUSTIC SOLITARY AND SHOCK WAVES FOR SATURN’S E-RING MAGNETIZED DUSTY PLASMA WITH q-NONEXTENSIVE ELECTRON DISTRIBUTION AND DUST CHARGE FLUCTUATIONS Location: In-Person Presentation, CDP Show/Hide Abstract DUST-ION-ACOUSTIC SOLITARY AND SHOCK WAVES FOR SATURN’S E-RING MAGNETIZED DUSTY PLASMA WITH q-NONEXTENSIVE ELECTRON DISTRIBUTION AND DUST CHARGE FLUCTUATIONS
Num Prasad Acharya1,2, Suresh Basnet1, Amar Prasad Misra3 and Raju Khanal1
1Central Department of Physics, Tribhuvan University, Kirtipur, Kathmandu 44613, Nepal
2Department of Physics, Mahendra Multiple Campus, Tribhuvan University, Ghorahi 22415, Dang, Nepal
3Department of Mathematics, Visva-Bharati (A Central University), Santiniketan-731 235, India
Email: numacharya@gmail.com
Abstract
We have investigated dust-ion acoustic solitary and shock waves in a magnetized dusty plasma and explored the features of solitary and shock waves in Saturn’s E-ring’s dusty plasma, in account of anisotropic ion pressure and dust charge fluctuations. The dust charge equation has been solved via Newton’s Raphson method. The modified damped KdV and Burger’s equations have been extended and analytically solved. In the case of space dusty plasma, we have taken the physical parameters relevant to Saturn’s E-ring and both compressive and rarefactive solitary and shock waves are evolved. The features of monotonic shock waves are significantly affected by the nonextensive parameter q, magnitude of magnetic field, obliqueness of wave propagation, anisotropic ion pressure, and size of dust grain as well. Furthermore, the dust charge fluctuation rate plays a crucial role in the study of shock wave evolution on Saturn’s E-ring dusty plasma.
References:
[1] A. P. Misra, Appl. Math. Comput., 256, 368–374 (2015).
[2] S. Ghosh, J. Plasma Phys., 71, 519–526 (2005).
[3] S. Bansal, M. Aggarwal, and T. S. Gill, Phys. Plasmas, 27, 083704 (2020).
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Abstract Number: ANPA2025-N00083 Presenting Author: Anup Shrestha Co-Authors: Amba Datt Pant; Hari Shankar Mallik; Anjan Dahal; Akihiro Koda; Katshuhiko Ishida; Burkhard Geil; Jumpei Nakamura; Shoichiro Nishimura; Hiromi Sakai; Koichiro Shimomura Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kathmandu, Nepal Title: A µSR study in oxyhemoglobin aqueous solutions Location: In-Person Presentation, CDP Show/Hide Abstract A low oxygen concentration in tumor tissue is known as hypoxia, which supports the progression of the tumor and resists the treatments [1,2]. To detect hypoxia, a non-invasive muon method has been proposed [3,4], which is expected to compensate for the current unavailability of such a method [5]. The development of the proposed muon method requires an organized muon spin rotation and relaxation (µSR) study of biomacromolecules. Oxyhemoglobin (OxyHb), a hemoglobin (Hb) derivative, transports oxygen (O2) from lungs to tissues and exhibits diamagnetism. Muon is similar to a proton with a lighter mass (mµ = 1/9 mp) and greater magnetic moment (µµ = 3.2 µp). It is an exotic magnetic probe sensitive to the magnetic field in the material. Muonium (Mu), a bound state of a muon and an electron (µ+e-), is like a light hydrogen isotope and directly interacts with O2. In this study, we performed ZF- and weak TF-µSR measurements in two concentrations (114.5 g/L and 5 g/L) of aqueous OxyHb solutions (purified from human blood) at temperatures ranging from 300 K to 140 K.
Isotropic Mu in liquid and axially symmetric anisotropic Mu in frozen phase are observed via concentration-dependent studies. In the liquid phase, in addition to the paramagnetic Mu, a diamagnetic muon species (H2O-Mu+-H2O) is observed, while in the frozen phase, two diamagnetic muon species (H2O-Mu+-H2O and MuOH) are observed, like in ice [6] and buffer [7]. The observed values of the Mu hyperfine transitions are in close approximation to the theoretically predicted values.
References
[1] M. C. Brahimi-Horn and J. Pouysségur, Journal of Molecular Medicine 85 (2007) 1301–1307.
[2] A. L. Harris, Nature Reviews Cancer 2, (2002) 38–47.
[3] A. D. Pant et. al., Journal of Physics: Conference Series 551(1), (2014) 012043.
[4] A. D. Pant et. al., Nuclear Instruments and Methods in Physics Research A 1011, (2021) 165561.
[5] J. P. B. O’Connor et al., Cancer Research 76, (2016) 787–795.
[6] A. D. Pant et al., Physical Review B 110, (2024) 104104.
[7] A. Dahal et al., oral presentation in this conference.
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Abstract Number: ANPA2025-N00041 Presenting Author: Yuwaraj K. Kshetri (Invited) Co-Authors: nan Presenter's Affiliation: Sun Moon University, Republic of Korea Title: Neutron Diffraction and Electronic Structure Investigation of Er-α-SiAlON for High-Temperature Sensing Location: In-Person Presentation, CDP Show/Hide Abstract α-SiAlON ceramics have been in use as engineering ceramics in the most arduous industrial environments such as molten metal handling, cutting tools, gas turbine engines, extrusion molds, thermocouple sheaths, protective cover for high-temperature sensors, etc., owing to their outstanding mechanical, thermal, and chemical stability. Taking advantage of the intrinsic properties of α-SiAlONs, we investigate the possibility of using the Er-doped α-SiAlON (Er-α-SiAlON) ceramic as a high-temperature sensing material via its unique near-infrared to visible upconversion property. We first use neutron diffraction and density functional theory calculations to study the electronic structure and thermodynamic stability of Er-α-SiAlON. Neutron diffraction is particularly essential in this study, as X-ray diffraction alone cannot precisely determine the atomic positions due to the similar X-ray scattering cross-sections of oxygen (O) and nitrogen (N) atoms. In contrast, neutron diffraction provides significantly different scattering cross-sections for O and N, enabling accurate crystal structure identification of SiAlON ceramics. It is found that the interstitial doping of Er stabilizes the α-SiAlON structure via chemical bonds with O-atoms with an N:O ratio of 5:2 in the seven-fold coordination sites of the Er3+ ion. Temperature-dependent upconversion emissions are then studied under 980 and 793 nm excitations over a temperature range of 298–1373 K, and the fluorescence intensity ratio (FIR) technique has been employed to investigate the temperature sensing behavior. Temperature-dependent Raman behavior is also investigated. We demonstrate that using Er-α-SiAlON as a sensing material, the limit of temperature measurement via the FIR technique can be pushed well beyond 1200 K.
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Abstract Number: ANPA2025-N0009 Presenting Author: Madhu Sudan Paudel Co-Authors: Basu Dev Ghimire; Narayan Prasad Chapagain Presenter's Affiliation: Central Department of Physics, IoST, TU, Nepal Title: Seismo-Ionospheric Coupling of Two Shallow and Moderate Earthquakes (M6.4) in Indonesia in 2024 Observed via TEC Analysis Location: In-Person Presentation, CDP Show/Hide Abstract Abstract
This study investigates seismo-ionospheric coupling phenomena associated with two moderate earthquakes (Mw 6.4) that occurred in Indonesia in 2024. The first event took place on March 22 near Paciran (5.875°S, 112.365°E) at a depth of 9.5 km, and the second on April 9 near Tobelo (2.698°N, 127.062°E) at a depth of 22.0 km. Ionospheric Total Electron Content (TEC) variations were analyzed using GNSS data from permanent ground stations BNOA and BTNG, provided by UNAVCO. A running-quartile method was applied to determine the upper and lower bounds of TEC variations. For the Paciran earthquake, anomalous TEC signals were detected 4–20 days prior to the event. Similarly, for the Tobelo earthquake, anomalies were observed 13–14 days before the event. To validate these findings, Global Ionospheric Map (GIM) data from the International GNSS Service (IGS) were examined, which revealed enhanced TEC over the respective epicentral regions on the identified anomalous days. The study discusses possible physical mechanisms responsible for these pre-seismic ionospheric perturbations.
Keywords: Seismo-ionospheric coupling, Total Electron Content, GNSS, ionospheric anomalies, Mw 6.4 earthquake, Indonesia
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Abstract Number: ANPA2025-N00015 Presenting Author: Bablu Kant Thakur Co-Authors: Dr. Lekha Nath Mishra; Dr. Rajendra Shrestha; Arun Kumar Shah; Ram Lal Shah Presenter's Affiliation: Tribhuvan University - Trichandra Multiple Campus, Physics Title: Impact of APPJ on Swiss Chard Seed Location: In-Person Presentation, CDP Show/Hide Abstract The atmospheric pressure plasma jet is generated with quartz glass tube of external diameter 5 mm and internal diameter 3 mm. Argon gas is used as working gas. The plasma jet has been characterized with measurement of electron density and electron temperature by electrical and optical method. The plasma jet is exposed on Swiss Chard seed. The germination percentage of Swiss Chard was found to be increased.
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Abstract Number: ANPA2025-N00020 Presenting Author: Saddam Husian Dhobi Co-Authors: Saddam Husain Dhobi; Surendra Hangsarumba; Raman Kumar Kamat;, Jeevan Jyoti Nakarmi; Kishori Yadav; Suresh Prasad Gupta; Ajay kumar Jha Presenter's Affiliation: Tribhuvan University Title: Thermal and Laser Field Driven PEMFC as Electron and Proton Sensing with Hydrogen Sources Location: In-Person Presentation, CDP Show/Hide Abstract This study explores a thermal and laser field-driven Proton Exchange Membrane Fuel Cell (PEMFC), focusing on surface scattering effects that lead to the formation of electrons and protons from hydrogen molecules. The system functions as a dual electron-proton sensor, enabling the detection of hydrogen sources through charge carrier interactions at the PEMFC surface. The primary objective is to examine the relationship between the differential cross-section (DCS) and the output voltage of the PEMFC, both theoretically and experimentally. A theoretical model was first developed using the thermal Volkov wave function, Kroll-Watson approximation, Bessel function and the first-Born approximation to analyze DCS behavior with respect to temperature. The results suggest that DCS increases with temperature, indicating greater electron separation and a corresponding decrease in the electric field and output voltage. To validate this model, a PEMFC prototype was designed and fabricated. Experimental findings revealed that applying a laser field increased voltage, while thermal input alone reduced it. However, the combined application of laser and thermal fields resulted in maximum voltage output. These observations suggest that higher voltage corresponds to stronger electric fields and closer electron interaction implying lower DCS while reduced voltage reflects weaker fields and dispersed electron interactions at the PEMFC surface.
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Abstract Number: ANPA2025-N00036 Presenting Author: Dharma Raj Paudel Co-Authors: nan Presenter's Affiliation: Central Department of Physics, T.U. Title: In Silico Identification of Natural Product Inhibitors Targeting SARS-CoV-2 Mpro Location: In-Person Presentation, CDP Show/Hide Abstract In Silico Identification of Natural Product Inhibitors Targeting SARS-CoV-2 Mpro
Dharma Raj Paudel1, Aashish Pokhrel2, Pooja Shrestha2, Saran Lamichhane1, Rajendra Prasad Koirala1, Indra Dev Sahu3, Pramod Aryal2, Narayan Prasad Adhikari1
1Central Department of Physics , Tribhuvan University
2Central Department of Biotechnology, Tribhuvan University
3Campbellsville University, United States of America
The COVID-19 pandemic, triggered by the highly transmissible SARS-CoV-2 virus, has had a profound and unparalleled effect on modern society, disrupting public health systems, economies, education, and cultural life. A single drug or vaccine may not be sufficient to counter emerging variants of the virus. Additionally, the complexity and side effects linked to earlier vaccines have contributed to ongoing hesitancy among certain groups. Mpro is a vital coronavirus enzyme responsible for viral replication and transcription, making it a prime target for SARS-CoV-2 drug development. In this study, the crystal structure of Mpro (PDB id: 6LU7) was utilized, and ligands from the ZINC database, identified as natural products, were screened for drugability using Lipinski rule of 5. Subsequent screenings involved targeting h-MAT1A and CYP3a4 proteins. Further screening was carried out as target protein docking and phase-1 drug clearances. The best ligands according to the docking score were selected. The selected ligands were further examined using density functional theory and molecular dynamics simulations for validation as potential drug candidates. Molecular dynamics simulations confirmed that the selected ligands exhibit considerable stability and establish numerous hydrogen bonds with the protein. Both DFT analysis and MD simulations indicate that the proposed ligands are promising as Mpro inhibitors and warrant further evaluation, including clinical trials.
Key Words : Virtual screening , Natural products, Mpro protein inhibitors, h-MAT1A , density functional theory, Molecular dynamics simulation
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Abstract Number: ANPA2025-N00048 Presenting Author: Bed Prasad Pandey Co-Authors: Santosh Kumar Pandit; Sanju Shrestha; Om Prakash Niraula; Kavindra Kumar Kavi Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kathmandu, Nepal Title: Performance Optimization of Triple-Metal High-K Dielectric Double-Gate Tunnel Field-Effect Transistor (TFET) for Enhanced Tunneling Characteristics Location: In-Person Presentation, CDP Show/Hide Abstract Vertical Tunnel Field Effect Transistor (VTFET) is being studied, because of its extremely low of sub-threshold swing (SS) and higher current ON-OFF ratio. Hence, various physical parameters and the performances of the optimal designed the Triple Metal High-K Dielectric Double Gate Vertical Tunnel Field Effect Transistor (VTFET), prepared by using 2D simulator using HfO2 / SiO2 as a gate dielectric and substrates are investigated. The calculated I_(on )/I_off ratio and the SS are found to be 1.85x 10^13 and 15.89 mV/decade. The higher value of the current ratio and the lower SS made its application as a fast switching and low power consumable device. The studies of analog parameters such as input and output capacitances and cutoff frequencies makes its applications in many analog and digital low power applications also.
Keywords: High-K dielectric, sub-threshold swing, vertical field effect transistor, fast switching, low power consumable device.
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Abstract Number: ANPA2025-N00061 Presenting Author: Pramod Kumar Thakur Co-Authors: Gopi Chandra Kaphle; Hari Prasad Lamichhane; Hari Shankar Mallik Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kirtipur, Kathmandu Title: Stabilities, properties and applications of Janus TaSeS 2D monolayer material Location: In-Person Presentation, CDP Show/Hide Abstract Janus 2D transition-metal dichalcogenide TaSeS monolayer exhibits a stable hexagonal crystal structure with lattice parameter 6.35 Ã… and negative values of cohesive and formation energies and positive distribution of frequencies obtained from phonon dispersion relation within the brillouin zone limit confirm its chemical and dynamical stability. All the calculations were performed through density functional theory based full potential plane-wave code within the generalized gradient approximation (GGA). The mechanical properties show its stability which is varied with the uniaxial and biaxial strain for elastic to plastic variation of the material. The electronic, magnetic, thermal and optical properties of the material show its prosing applications in the field of piezoelectric devices, field-effect transistors (FETs), optoelectronics, and spintronics devices.
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Abstract Number: ANPA2025-N00060 Presenting Author: Krishna Prasad Chapai Co-Authors: Durga Paudyal Presenter's Affiliation: Mid-West University,Surkhet,Nepal Title: Structural and Electronic Properties in Doped VCl3 Monolayer : A Density Functional Study Location: In-Person Presentation, CDP Show/Hide Abstract Two dimensional transition metal trihalides are van dar Waals (vdW) crystal which are becoming field of interest due to their intrinsic ferromagnetism and anisotropic feature down to monolayer limit. The exfoliated 3d-transition metal trihalides from its bulk counterpart has got immense interest due to its peculiar properties useful for the spintronic and memory storage applications. We report the exciting properties for pristine and 3d-TM doped VCl3 layered materials using density functional theory approach. The pristine VCl3 monolayer is found to be stable in P3 structure whose chemical stability is confirmed by negative value of cohesive and formation energy. The pristine and 3d -TM ( Cr, Ti ) doped VCl3 are found to be ferromagnetically stable in ground state. We found 2D-VCl3 as intrinsic Dirac Half Metal (DHM) in one spin channel which is immensely useful for spin current generation. Our result reveals that doping of 3d-TM ( Cr,Ti) on pristine VCl3 affects electronic and magnetic properties by altering electronic structure from DHM to semiconducting or half metallic state. The study highlights the doped structure possessing the tunable band gap at monolayer scale and its potential application for spintronics through dopant engineering.
Keywords: 2D transition metal trihalides, anisotropy, electronic properties, Dirac Half Metal, Spintronics.
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Abstract Number: ANPA2025-N00075 Presenting Author: Karishma Rana Co-Authors: nan Presenter's Affiliation: Amrit Campus, Tribhuvan University Title: STUDY OF VARIATION OF ACTIVITY CONCENTRATION OF 226-Ra, 232-Th AND 40-K AND THE RADIOLOGICAL PARAMETERS THROUGH RADIOMETRIC SURVEY FROM SETIBENI TO PURTIGHAT Location: In-Person Presentation, CDP Show/Hide Abstract We have studied terrestrial radioactivity due to naturally occurring radioactive materials (NORMS) 226-Ra, 232-Th, and 40-K and some radiological parameters using the portable gamma-ray spectrometer (PGIS-2) from Setibeni to Purtighat, Nepal via the Kaligandaki corridor. The activity concentrations of 226-Ra, 232-Th, and 40-K were found to be 1202.02 Bq/kg, 91.64 Bq/kg, 83.20 Bq/kg respectively. The absorbed dose rate was found to be143.08 nGy/h, the internal hazard index was 1.07, the annual effective dose equivalent value was 0.18 mSv/year, and the excess lifetime cancer risk factor was 0.62. The result indicated that despite the higher activity concentration of 226-Ra, 232-Th, and 40-K, the study area is non-hazardous and the materials are safe to use in construction. This could be due to the high concentrations of radionuclides on the bank of the Kaligandagi River. The correlation of dose rate with the activity concentrations of 226-Ra, 40-K, and 232-Th were also plotted separately
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Abstract Number: ANPA2025-N00025 Presenting Author: Abdul Klam Khan Co-Authors: nan Presenter's Affiliation: Central Department of Physics, Tribhuvan University Title: EFFECT OF PLASMA ACTIVATED WATER IN THE YIELD OF OYSTER MUSHROOM Location: In-Person Presentation, CDP Show/Hide Abstract In this study, plasma-activated water (PAW) produced using gliding arc discharge plasma was used to observe its effect on the budding and growth of oyster mushrooms. The activation of de-ionised water by plasma causes significant changes in the physical and chemical properties of PAW. With the increase in treatment time of the water, the pH of the water decreased, while the electrical conductivity, oxidation-reduction potential, total dissolved solids, and the levels of nitrate and nitrite increased. PAW showed a strong effect on the budding and production of oyster mushrooms. Notably, when 20-minute treated PAW was used, the seeds budded faster, and the production yield was higher. These results suggest that plasma-activated water can be an effective method to enhance the cultivation of oyster mushrooms.
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Abstract Number: ANPA2025-N00024 Presenting Author: Ramesh Khanal Co-Authors: Dr. Suresh Basnet; Prof. Raju Khanal Presenter's Affiliation: Student Title: Magnetized Plasma-Wall Interaction Mechanism in the Presence of Secondary Electron Emission Relevant to Fusion Devices Location: In-Person Presentation, CDP Show/Hide Abstract Understanding plasma-wall interactions is crucial for improving the performance, lifetime, and
stability of magnetically confined fusion devices. This study employs a kinetic trajectory
simulation method to investigate the plasma-wall interaction (where the surfaces are tungsten,
carbon, and molybdenum) in the presence of secondary electron emission, energy-dependent
sputtering effects, self-consistent electric fields, and oblique magnetic fields. The model is
constrained to a 1D3V, time-independent, collisionless framework. Particle distribution functions
at the injection plane are assumed to be cut-off Maxwellians. Ion distribution functions are
obtained by tracing exact trajectories in phase space, while electron and emitted electron
densities are analytically obtained. Key plasma-wall transition conditions; quasineutrality,
sheath-edge singularity, continuity of macroscopic fluid parameters, and the Bohm sheath
criterion are satisfied, with a presheath-sheath coupling applied for smooth transition between
presheath-sheath boundary. The Bohm sheath condition is extended to multi-component plasmas
with cut-off distributions of emitted electrons. Simulations reveal that emitted electrons
substantially modify the potential profile, flattening the potential drop and introducing non-
monotonic structures. In oblique magnetic fields, the Bohm velocity for ions decreases with field
angle, reflecting stronger field-aligned motion requirements, while strong electron emission
lowers these velocity thresholds by weakening the sheath potential. Regarding material erosion,
tungsten shows the lowest sputtering yields than that of molybdenum, and carbon surfaces,
emphasizing the critical role of material selection in plasma-facing component design for fusion
devices.
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Abstract Number: ANPA2025-N00023 Presenting Author: Saroj Pandeya Co-Authors: Suresh Basnet; Raju Khanal Presenter's Affiliation: Tribhuvan University Title: Oblique Propagation of Ion-Acoustic Solitary Waves in 3D3V Magnetized Quantum Plasma with Anisotropic Electron and Ion Pressures. Location: In-Person Presentation, CDP Show/Hide Abstract Quantum ion-acoustic solitary waves (QIASWs) are studied in dense astrophysical environments, and collisional laboratory plasmas employing a quantum hydrodynamic model with anisotropic temperatures, constant magnetic field along z-axis, and the Bohm potential gradient to examine the formation and evolution of QIASWs. Anisotropic equation of state with degeneracy (relativistic and non-relativistic) for white dwarf plasma, and double adiabatic approximation for laboratory collisional plasma are applied in polytropic form in two-fluid momentum transport equations. Effect of weak magnetization on solitary vortical structures is also studied in fermi plasma. Hydrodynamic approximation is ensured for each plasma by satisfying conditions involving the mean free path, quantum plasma Debye length, and characteristic plasma length and time scales. Using the multiscale reductive perturbation technique with distinct ion, electron and potential expansion parameter, we derived the Korteweg–de Vries (KdV), dissipative KdV, and modified KdV (mKdV) equations, balancing of nonlinearity and dispersive effects, and compared with previous studies. The phase velocity of a solitary wave was found to be decreasing with obliqueness, independent of stretching and perturbation parameters, but depended on equilibrium pressures along the direction of the magnetic field, equilibrium density of species, and dust charge. The effect of viscous forces contributes to the damping of solitary waves leading to continuously decreased amplitude and increased width along stretched spacetime coordinates in laboratory plasma. Increasing magnetic field was found to increase amplitude and compress width of refractive as well as compressive solitary structures in each plasma at different cases i.e. T_(∥ ) >T_⊥, T_(∥ )=T_⊥, and T_(∥ ) |
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Abstract Number: ANPA2025-N00017 Presenting Author: Raman Kumar Kamat Co-Authors: Raman Kumar Kamat, Surendra Hangsarumba, Kishori Yadava, Suresh Prasad Gupta, Prakash M. Shrestha, Saddam Husain Dhobi Presenter's Affiliation: Department of Physics, Patan Multiple Campus, Tribhuvan University, Patan Dhoka, Lalitpur-44700, Nepal Title: Optical Characterization of Carbon Quantum Dots Under Laser and Magnetic Field Treatments Location: In-Person Presentation, CDP Show/Hide Abstract This study explores the influence of external treatments laser and magnetic field on the optical behavior of carbon quantum dots (CQDs) at varying concentrations. The approach aims to enhance understanding of how such treatments can modulate CQDs’ optical properties for advanced photonic and sensing applications. This study investigates the optical transmittance of CQDs at various concentrations (100%, 50%, 25%, and 12.5%) under different conditions, including laser and magnetic field treatments, all conducted at room temperature. CQDs were synthesized via a microwave-assisted method by mixing 0.2 g of thiourea and 0.4 g of citric acid, heated at 165 °C for 2 minutes. The heating product was dispersed in 40 mL of distilled water, followed by sonication and centrifugation. The optical properties were evaluated using a Theremino spectrometer, while CQDs confirmation was conducted by observing the fluorescence response under UV light after dropping into distilled water. The results demonstrated that the optical intensity was lowest at 100% concentration and gradually increases with dilution, reaching the lowest intensity at 12.5% diluted. For the 50% CQDs solution, samples were treated with a 100 mW laser and a 0.20 T magnetic field for 4 minutes. Compared to the untreated sample, the laser-treated CQDs showed increased intensity, whereas magnetic field treatment resulted in reduced intensity. Additionally, refractive index measurements using a rotating spectrometer revealed values of 1.340± 0.01 for the untreated 50% diluted sample, 1.350± 0.01 after laser treatment, and approximately 1.360 ± 0.01 after magnetic field treatment. These findings indicate that both treatments significantly influence the optical behavior and refractive index of CQDs.
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Abstract Number: ANPA2025-N00073 Presenting Author: Abhinav Pokharel Co-Authors: Rupisha Dangol Presenter's Affiliation: Tribhuvan University (Amrit Science Campus) Title: Quantum Key Distribution Using BB84 Protocol: A Computational Study of Error Rates Location: In-Person Presentation, CDP Show/Hide Abstract Quantum key distribution (QKD) enables a secure communication between two parties using the principles of Quantum Physics. The BB84 protocol, one of the first protocols in QKD, is effective not just for sharing keys but also for detecting eavesdropping. The paper simulated a computational model of QKD, analyzing error rates under varying conditions of the number of bits (n). Using Python-based simulation, this paper simulated key exchanges for n = 10, n = 100, n = 1000 bits. We also incorporated a 0.02 noise probability to simulate real–world conditions for both with and without eavesdropping. Each scenario was repeated over 1000 trials to obtain an average error rate. Our results show that, without eavesdropping, the average error rate remains close to 2 %, showcasing BB84’s stability against small noise. In the presence of an eavesdropper, the average error rate consistently exceeds 26%. Moreover, the standard deviation of error increases as n decreases, indicating higher variability in smaller datasets. While this study focuses on computational validation, the future work will extend towards building a low-cost experimental setup using basic optical tools.
Keywords: BB84 protocol, computational simulation, eavesdropping detection, noise modeling, QKD
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Abstract Number: ANPA2025-N00021 Presenting Author: Santosh Dhungana Co-Authors: Raju Khanal; Hom Bahadur Baniya Presenter's Affiliation: Tribhuvan Univesity Title: Physical and Chemical Profiling of Plasma-Activated Water Under Varying Treatment Conditions and Its Application in Plant Growth Location: In-Person Presentation, CDP Show/Hide Abstract Gliding arc discharge (GAD) system is a simple and inexpensive way to generate non-thermal plasma and has various applications in the fields of material processing, gas conversion, medical sterilization, and agriculture. In the field of agriculture, it can be used directly by treating seed and indirectly by preparing plasma activated water (PAW). Due to the presence of reactive oxygen and nitrogen species (RONS), it is considered a green fertilizer for seed germination and plant growth. In our work, GAD system was used to produce PAW and its physiochemical properties are examined under varying treatment conditions including treatment time, air flow rate, applied voltage and water volume. A significant change in physical (pH, electric conductivity (EC), oxidation reduction potential (ORP), total dissolved solid (TDS), salt, etc.) and chemical (concentration of nitrate, nitrite and hydrogen peroxide) properties of water are observed at different treatment conditions. Finally, the PAW is utilized to irrigate the newly germinated seedling of red cherry pepper chili (Akabare Khursani) in order to study its on growth.
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Abstract Number: ANPA2025-N00026 Presenting Author: Samjhana Dahal Co-Authors: Roshan Chalise, Raju Khanal Presenter's Affiliation: Student (Tribhuvan University) Title: Germination and Seedling Growth Enhancement Of Timur Seed (Zanthoxylum armatum) By Using Cold Atmospheric Pressure Plasma Location: In-Person Presentation, CDP Show/Hide Abstract Timur is a plant native to the Himalayan region and it is valued for its intense citrusy and peppery flavor, used in culinary and traditional practices. In this work, we have used gliding arc discharge for direct treatment of the Timur seed (Zanthoxylum armatum) and used plasma activated water, prepared by cylindrical dielectric barrier discharge and gliding arc discharge, to irrigate the plants, aiming to enhance germination and seedling growth. The plasma sources are characterized through electrical and optical characterization methods. From spectrometer, electron temperature of cylindrical dielectric barrier discharge and gliding arc discharge is found to be 1.41 eV and 1.66 eV with plasma density found to be 8.17 × 10 18 m −3 and 5.48 × 10 17 m −3 , respectively. Plasma treatment increases the
temperature, total dissolved solids, electrical conductivity, and oxidation-reduction potential of the plasma-activated water with the activation time; however, the potential of hydrogen decreases. In addition, it has been observed that nitrate concentration is notably higher than nitrite concentration. It has been observed that the direct application of plasma on Timur seeds results in changes to the seeds, particularly in their surface properties and wettability. The results showed that the wettability of seeds using two minutes (min) plasma-activated water increases the most compared to the untreated seeds and other treatment times. Although germination enhancement of the Timur seeds is not achieved in the laboratory condition, plasma-activated water positively impacts root and shoot growth, as well as
in the retention of chlorophyll content (or greenness) of leaves. A treatment time of four minutes using cylindrical dielectric barrier discharge and two minutes using plasma jet is found most favorable. The positive impact of plasma on Timur plants can be studied further to enhance germination, seedling growth, and ultimately, fruit yield, making it viable for agricultural applications in real field conditions.
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Abstract Number: ANPA2025-N0003 Presenting Author: Manjeet Kunwar Co-Authors: Nabin Bhusal ; Manil kathiwada; Niraj Dhital Presenter's Affiliation: Central Department of Physics ,TU Title: Optimize cosmological parameters to fit large-scale structure observations of dark matter distribution. Location: In-Person Presentation, CDP Show/Hide Abstract We optimize cosmological parameters to achieve the best fit between theoretical models and large-scale structure observations of dark matter distribution. Using constraints on the matter density parameter (Ωₘ) and the fluctuation amplitude (σ₈) from the Dark Energy Survey (DES) and the Planck mission, we refine parameter estimation within the ΛCDM framework. Additionally, we explore model extensions, including wCDM, massive neutrinos, and modified gravity, to improve consistency with observational data. To quantify potential tensions between DES and Planck results, we analyze the S₈ parameter, defined as S8=σ8Ωm/0.3S8​=σ8​Ωm​/0.3, to assess deviations and optimize cosmological fits.
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Abstract Number: ANPA2025-N0004 Presenting Author: Primos Khatiwoda Co-Authors: nan Presenter's Affiliation: Independent Researcher Title: Hypothesis on Blackholes as Dimensional Portals and Information Preservation Location: In-Person Presentation, CDP Show/Hide Abstract Background: Black holes are traditionally viewed as cosmic entities from which nothing can escape, leading to the notion that information
is lost when it crosses their event horizons. This idea is challenged by the information paradox, which raises questions about the preservation
of information in light of quantum mechanics.
Objective: This manuscript aims to propose a new hypothesis that redefines the nature of black holes by suggesting they function as
dimensional portals, preserving information instead of destroying it.
Methods: A mathematical model is introduced, featuring a teleportation function, T(D), that describes how information transforms when
moving from our three-dimensional space into a higher-dimensional framework.
Results: The proposed hypothesis aligns with the principles of quantum mechanics, suggesting that information is retained in a different
dimension and may enhance our understanding of black hole thermodynamics, including concepts like Hawking radiation and entropy.
Conclusion: The idea of black holes as dimensional portals offers a fresh perspective on the information paradox and presents new avenues
for future research in both theoretical and observational physics.
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Abstract Number: ANPA2025-N00047 Presenting Author: Sandip Kumar Dangi Co-Authors: Sarita Regmi; Dinesh Kumar Chaudhary; Pitamber Shrestha Presenter's Affiliation: Amrit Campus, Lainchaur, Kathmandu Title: Electro-Chemical and Optical Characterization of SnO2 Film Location: In-Person Presentation, CDP Show/Hide Abstract Metal oxide thin films have gained considerable attention due to their diverse applications in agriculture, medicine, industry, and advanced technologies. Among these, SnOâ‚‚ thin films have emerged as promising materials for optoelectronic applications. In our study, SnOâ‚‚ thin films were synthesized on fluorine-doped tin oxide (FTO) substrates using a spin-coating technique, followed by annealing at 400°C to enhance crystallinity. The prepared samples were analyzed by various techniques such as FTIR spectroscopy, UV-Vis spectroscopy and Impedance spectroscopy. FTIR analysis confirmed the formation of the SnOâ‚‚ lattice with distinctive peaks at 516 cmâ»Â¹ and 754 cmâ»Â¹. UV–Vis revealed that optical transmittance decreased with increasing film thickness, while the optical band gap increased slightly from 3.45 eV to 3.55 eV. Concurrently, a decrease in Urbach energy from 0.2154 eV to 0.1619 eV suggested a reduction in defect density. The refractive index, determined via the Swanepoel method, stabilized at approximately 1.83, indicating enhanced densification and reduced porosity. Impedance spectrum showed that although the series resistance remained relatively constant, the charge transfer resistance increased and capacitance decreased with film thickness, indicating the critical role of film thickness in tuning the optical and electrical properties of SnOâ‚‚ thin films, paving the way for their optimized use in optoelectronic applications. Keywords: Tin oxide, Spin coating, Band-gap, Impedance spectrum, FTIR analysis.
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Abstract Number: ANPA2025-N00044 Presenting Author: Saroj Kafle Co-Authors: nan Presenter's Affiliation: Tribhuvan University Title: Investigation of optical and electrical properties of fluorine doped ZnO Thin films prepared by spray pyrolysis Location: In-Person Presentation, CDP Show/Hide Abstract This research project investigates the optical and electrical properties of fluorine-doped ZnO (F-
ZnO) thin films deposited on FTO-coated glass substrates using the spray pyrolysis technique.
ZnO films with a fluorine doping concentration of 15% were synthesized at approximately 400°C
from a 0.1 M precursor solution. Band gap energies decreased from 3.27 eV for undoped ZnO
to 3.15 eV for an 8-layer doped film, as determined using UV-Vis spectroscopy and Tauc plots.
Electrical characterization, performed using an LCR meter, revealed Nyquist plots with semicircular
patterns for all layers, indicating impedance behavior dominated by single relaxation processes. As
the number of layers increased from 2 to 8, bulk resistance (ð‘…2) consistently decreased (e.g., from
287.46 Ω for 2 layers to 76.61 Ω for 8 layers ), while capacitance (ð¶1) slightly increased, confirming
improved electrical conductivity. The equivalent circuit model extracted parameters, including ð‘…1,
ð‘…2 , and ð¶1, focusing on the efficient charge transport and storage properties of these films. These
results demonstrate that increasing the thickness of fluorine-doped ZnO films significantly enhances
their optical and electrical properties, making them highly suitable for applications such as solar
cells and sensors.
Keywords: ZnO thin film, Fluorine-doped ZnO, Spray pyrolysis, Nyquist plot, Optical band gap,
Electrical conductivity
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Abstract Number: ANPA2025-N00076 Presenting Author: Surendra Hangsarumba Co-Authors: Surendra Hangsarumba, Raman Kumar Kamat, Kishori Yadav, Suresh Prasad Gupta, Prakash M. Shrestha, Saddam Husain Dhobi Presenter's Affiliation: TU IoST, Patan Multiple Campus, Patandhoka,Lalitpur Title: Radiation Shielding Properties of Waste Materials Using a Geiger-Müller Counter and Different Radioactive Sources Location: In-Person Presentation, CDP Show/Hide Abstract Radiation shielding is a crucial safety measure used to reduce exposure to harmful ionizing radiation by using materials that absorb or block radiation. Effective shielding helps protect human health, equipment, and the environment in medical, industrial, and research settings. This study evaluates the shielding properties of waste materials plastic bottles, human hair, disposable medical gloves, and cardboard against three radioactive sources: Thallium (204Tl), Cesium (137Cs), and Strontium (90Sr), with present activities 0.05 µCi, 1.125 µCi, and 0.130 µCi, respectively. Samples of each material were prepared in solid form with dimensions 3 × 4 × 0.2 cm. Using a Geiger-Müller (GM) counter (Model No: TE Np 1, 220-230V, 50 Hz) at Patan Multiple Campus, radiation counts/minute were measured with the sample placed 6 cm from the source and 4 cm from the detector window, operated at 400 V. Without shielding, the counts/minutes recorded were 38 ± 3 counts/minute with 204Tl sources , 72± 4 counts/minute with 137Cs sources, and 182± 3 counts/minute with 90Sr sources. When shielded, the counts/minute observed for the 204Tl source were with plastic bottle is 32± 3 counts/minute, human hair is 6± 3 counts/minute, gloves is 6± 3 counts/minute, and cardboard is 30± 3 counts/minute; for the 137Cs source with plastic bottle is 58 counts/minute, human hair is 12± 3 counts/minute, gloves is 12± 3 counts/minute, and cardboard is 52± 3 counts/minute; and for the 90Sr source with plastic bottle is 180± 4 counts/minute, human hair is 20± 4 counts/minute, gloves is 26± 4 counts/minute, and cardboard is 132± 4 counts/minute. The background counts/minute without sources for all direction is 13 counts/minute. This indicate that human hair and gloves significantly reduced radiation counts compared to other materials, suggesting better shielding efficiency. These waste materials, due to their composition and effectiveness, could be utilized in developing low-cost radiation protection structures in areas with high radiation exposure.
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Abstract Number: ANPA2025-N00042 Presenting Author: Kaushal Pyakurel Co-Authors: Leela Pradhan Joshi Presenter's Affiliation: Central Department of Physics, TU Title: Synthesis and Electrochemical Performance of Activated Carbon from Lapsi Seed Biomass for Supercapacitor Application Location: In-Person Presentation, CDP Show/Hide Abstract The conversion of biomass waste into porous carbon for supercapacitor electrode application represents a promising
approach due to the low cost, abundance of raw materials, and environmental advantages. In this study, activated carbon(AC) was
synthesized from Lapsi (Choerospondias axillaris) seed biomass by chemical activation method with zinc chloride (ZnCl2) fol-
lowed by carbonization in the tubular furnace at 850 °C under continuous nitrogen flow of 100 cc/min for 4 hours. Electrochemical
characteristics of the AC electrode was studied in a three-electrode system with a potentiostat device through cyclic voltammetry
(CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The electrochemical parameters
such as specific capacitance, stability, and impedance are evaluated. The electrode exhibited a specific capacitance of 71.95 F/g
at a current density of 1 A/g and maintained 95.71% capacitance retention over 5000 cycles, demonstrating good electrochemical performance.
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Abstract Number: ANPA2025-N00062 Presenting Author: Ambika Shahi Co-Authors: nan Presenter's Affiliation: Central Department of Physics, Tribhuvan University Title: To investigate the Structural, Electronic and Magnetic properties of CrGa2S4 Location: In-Person Presentation, CDP Show/Hide Abstract Condensed matter physics, as a field, integrates various aspects of natural science, including theoretical, experimental, and computational approaches. It enables the exploration and understanding of novel materials across different length scales, from the atomic-microscopic levels to macroscopic phenomena. In this work, the Transition Metal (TM)-based ternary chalcogenide CrGa2S4 compound is a novel material that exhibits intriguing structural, electronic, and magnetic properties in both bulk and 1-structural layer, adopting an α-FeGa2S4-1T type phase. It crystallizes in the P-3m1 space group with lattice parameters a = 3.60 ˚A and c = 11.94 ˚A. First-principles calculations based on density functional theory were performed using the FPLO code with GGA, GGA+U, and GGA+SOC functionals. To achieve accurate band gap predictions, GGA+mBJ and GGA+mBJ+SOC were employed. The bulk structure exhibits a ferromagnetic ground state with half-metallic behavior, while the 1-structural layer undergoes a transition to a semiconducting state with an indirect band gap of 0.72 eV. The magnetocrystalline anisotropy energy calculations reveal an easy axis along [001] for the bulk and [100] for the 1-structural layer. This study emphasizes the phenomenal influence that dimensionality reduction on the electronic structure and offers insight into the tunability of electronic and magnetic characteristics. These findings pave the way for potential applications in electronic storage devices, particularly in spintronics.
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Abstract Number: ANPA2025-N00082 Presenting Author: Roshan Nepal Co-Authors: Anup Shrestha ; Anjan Dahal Presenter's Affiliation: Tribhuvan University Title: Detaction of metal oxidation states in halides using muon: a first-principle study Location: In-Person Presentation, CDP Show/Hide Abstract Metal oxidation states play an important role in determining the properties (magnetism, catalysis, ion conductivities, etc.) of wide varieties of materials. For example, in biology, O2 binding hemoglobin (oxyhemoglobin) contains Fe in ferrous states in its heme-group however the methemoglobin that cannot bind the O2 contains the ferric states of the Fe. From magnetic point of view, oxyhemoglobin shows diamagnetic nature however the methemoglobin shows the strong paramagnetic behavior. Since muon acts as a sensitive local probe, it can detect local electronic and dynamic states of materials. To understand the muon experimental data, computational technique, particularly density functional theory (DFT), is essential for revealing muon sites in the materials. Here we choose metal-halides with differing oxidation states (Fe2+ in FeCl2, Fe3+ in FeCl3, and Zn2+ in ZnCl2) to understand the behavior of muon in samples with different oxidation states. The FeCl₂ and FeCl₃ exhibit magnetic ordering [1], while the ZnCl₂ exhibits nonmagnetic [1]; consequently, the muon’s local stopping site, spin polarization, and electronic interactions vary among these compounds [2, 3]. We focus to identify and compare the muon sites and estimate its polarization in different oxidation states, and then investigate muon–metal interactions. In the program, the DFT result of muon behavior in FeCl2 and ZnCl2 will be presented.
References
[1] N. N. Greenwood, and A. Earnshaw, 2nd ed. (Chemistry of the Elements, Butterworth-Heinemann, 2012).
[2] I. J. Onuorah et. al., Phys. Rev. B, 97 (2018) 174414.
[3] S. J. Blundell and T. Lancaster, Appl. Phys. Rev. 10, (2023) 021303.
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Abstract Number: ANPA2025-N00084 Presenting Author: Anjan Dahal Co-Authors: Amba Datt Pant; Hari Shankar Mallik; Anjan Dahal; Akihiro Koda; Katshuhiko Ishida; Burkhard Geil; Jumpei Nakamura; Shoichiro Nishimura; Hiromi Sakai; Koichiro Shimomura Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kathmandu, Nepal Title: Understanding Muonium Anisotropy in Phosphate Buffered Saline: A ?SR Study Location: In-Person Presentation, CDP Show/Hide Abstract To establish the fundamentals of muon and muonium behavior in the biological system and its application in the cancer research, muon spin relaxation and rotation (?SR) experiments are conducted in water, buffer solutions, proteins, biomacromolecules and Hemoglobin. We have conducted experiment in several bio-samples and perform DFT calculations to support the experiments. This work focuses on ?SR experiment in phosphate-buffered saline (PBS) which is a biologically relevant medium often used in the medical applications and experimental biology. Muon is like a light proton (m?~1/9 mp) but with higher magnetic moment (??~3.2?p). When the positive muon implanted in a sample it captures an electron forms a hydrogen like atom called muonium (Mu). This light muonium acts as an ultra-sensitive probe, settling at reactive molecular sites to reveal detailed information about local electronic and magnetic environments of the sample. The experiment was performed in the temperature range of 140 K to 300 K under various low magnetic fields and muonium precession signal was observed. In the liquid state of PBS, an isotropic muonium along with a diamagnetic muon were observed. However, in frozen PBS, two distinct diamagnetic muon species and an axially symmetric anisotropic muonium like in frozen water were observed. In the program temperature dependent nature of the anisotropic muonium will be presented.
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Abstract Number: ANPA2025-N00059 Presenting Author: Bimala Debi Subedi Co-Authors: GAMBHIR KHAN THAKURI 7; LEELA PRADHAN JOSHI Presenter's Affiliation: Atmospheric and Material Science Research Centre, Amrit Campus, Tribhuvan University, Kathmandu, Nepal bDepartment of Physics, Prithvi Narayan Campus, Tribhuvan University, Pokhara, Nepal. Title: Electrochemical performance of activated carbon derived from waste wood of Alnus nepalensis for supercapacitor application Location: In-Person Presentation, CDP Show/Hide Abstract The growing demand for sustainable energy storage solutions has accelerated the development of advanced energy storage technologies. Traditional carbon materials sourced from fossil fuels present challenges such as high costs, complex processing, and potential environmental risks. In contrast, biomass-derived activated carbon has emerged as a highly promising alternative, offering advantages like natural abundance, high carbon content, and straightforward processing with minimal toxicity. This study outlines the production of activated carbon from waste wood of Alnus nepalensis through a series of processes, including activation using zinc chloride as the activating agent, followed by pre-carbonization and carbonization at 600°C in a tube furnace under a continuous flow of N₂ gas. The activated carbon was analyzed using various methods, including FTIR testing, while its electrochemical performance was evaluated through CV, GCD, EIS, and CV retention tests. These tests were conducted using a three-electrode arrangement with different reference electrodes (Hg/HgO, Ag/AgCl) and 6M KOH aqueous electrolyte solution. As a supercapacitor electrode material, AC exhibited a specific capacitance of 186.03 F/g at a current density of 1A/g, an energy density of 6.46 Wh/kg, and a power density of 124.99 W/kg. It demonstrated capacitance retention of 64.5% after 1,000 charge–discharge cycles at a current density of 1 A/g using an Hg/HgO reference electrode in a 6M KOH electrolyte. These results provide valuable insights into the development and electrochemical analysis of eco-friendly biomass-derived porous carbon, highlighting its potential as a supercapacitor electrode material.
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Abstract Number: ANPA2025-N00043 Presenting Author: Sarita Regmi Co-Authors: Sandip Kumar Dangi; Dinesh Kumar Chaudhary; Pitamber shrestha Presenter's Affiliation: Amrit Campus Title: OPTICAL AND ELECTROCHEMICAL PROPERTIES OF Co3O4 FILM Location: In-Person Presentation, CDP Show/Hide Abstract Cobalt oxide films have gained substantial research effort because of their electronic and optical properties in diverse fields, such as agriculture, industry, and energy storage. Herein, cobalt oxide (Co3O4) films on a fluorine-doped tin oxide glass substrate were synthesized by the spray pyrolysis technique and annealed in an air atmosphere at 350 ºC for 2 hours. The different layers of cobalt oxide films were prepared on an FTO-coated glass substrate, and the films formed were blackish-white. The prepared films were characterized using FTIR spectroscopy, UV-visible spectroscopy, and impedance spectroscopy. The FTIR spectra showed the two stretching bands Co(III)-O and Co(II)-O, which confirms the material composition of Co3O4. The optical measurements demonstrated that increasing the layers of cobalt oxide films, the band gap energy decreases. The thickest layer (Layer 9) showed the minimum band gap of about 2.21 eV. The impedance measurement was carried out from the high to low-frequency range, where the obtained impedance spectrum revealed enhanced conductivity and reduced grain boundary resistance with increasing film thickness, which may be due to increased mobility of charge carriers and reduced grain size. These results showed the tunable optical properties and enhanced charge transfer, highlighting the potential application for optoelectronic devices and supercapacitor applications.
Keywords: Cobalt oxide, Impedance, Thin film, Spray pyrolysis, Band gap
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Abstract Number: ANPA2025-N00010 Presenting Author: Anu Aryal Co-Authors: nan Presenter's Affiliation: Central Department of Physics, T.U Title: A study on quantum theory of consciousness to understand the very origin of mass. Location: In-Person Presentation, CDP Show/Hide Abstract There are many unsolved mysteries of the universe—such as its expansion, the debated nature of space-time, and the origin of the very first mass. The beauty of physics lies in the freedom that it offers researchers to explore these questions with creativity. One emerging field is the quantum theory of consciousness, which takes analytical, theoretical, mathematical, and philosophical approaches to understand the universe from a unique perspective. Quantum field theory, for instance, describes how different fields give rise to different particles—such as the Higgs boson arising from the Higgs field—providing insight into the origin of mass from the field itself. The study of the quantum theory of consciousness may offer a new lens through which to comprehend the nature of reality itself. This study is especially vital, as it not only seeks to explain the nature of reality but also considers the observer who perceives it. Since space-time forms the framework within which nearly all physical events occur, incorporating consciousness into this framework could deepen our understanding of existence. This kind of new study holds an enormous potentiality to unlock new perspectives on black holes, dark matter, and more.
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Abstract Number: ANPA2025-N00079 Presenting Author: Bal Vikram Khatri Co-Authors: Om Prakash Niraula; Himali Kalakhety; Raju Khanal Presenter's Affiliation: Tribhuvan University Title: In-Situ Radiometric Study Along the Kaligandaki River: Focus on the Deepest Gorge and Shaligram Fossils Location: In-Person Presentation, CDP Show/Hide Abstract An in-situ radiometric survey was conducted along the stretch of the Kaligandaki River in Nepal, a region of geological significance that features the world's deepest gorge and the presence of Shaligram fossilized ammonites, which hold both cultural and scientific importance. Kaligandaki River, one of major Rivers of Nepal, originates from Damodarkund close to Lomanthang, where deposit of Uranium have been confirmed by Department of Mines and Geology, Nepal. The famous fossilized stone Shaligram is also found only in this region. To carry out the study, we used the portable gamma-ray spectrometer PGIS-2, which is equipped with a NaI(Tl) detector. We determined radiological hazard parameters associated with the radionuclides, including radium equivalent activity, absorbed gamma dose rates in the air, annual effective dose rate, external hazard index, and internal hazard index. The results showed that 238U activity ranged from 55.17 Bq kg−1 to 125.63 Bq kg−1 with mean value 83.31 ± 19.49 Bq kg−1, 232Th activity ranged from 2.28 Bq kg−1 to 144.22 Bq kg−1 with mean value 61.55 ± 31.29 Bq kg−1 and 40K activity ranged from 92.48 Bq kg−1 to 1158.06 Bq kg−1 with mean value 631.44 ± 269.95 Bq kg−1. Mean values of the activities of all three radionuclides were found to be above the world average value. Radiological parameters like Raeq, ADR, Hex and Hin were found to be 219.95 ± 72.76 Bq kg−1, 102.18 ± 33.53 nGy hr-1 0.59 and 0.82 respectively. This study underscores the importance of continuous monitoring to ensure environmental and public safety in regions with naturally occurring radioactive materials.
Keywords: PGIS-2, Hazard index, Gamma dose rate, Radiation hazard
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Abstract Number: ANPA2025-N00080 Presenting Author: Devendra Raj Upadhyay Co-Authors: Orgin Tamang; Raju Khanal Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kathmandu, Nepal Title: Radiation Shielding and Transport Characeristics of Zinc Lithium Dysprosium Borotellurite Glasses Using Theoretical and Monte Carlo Code Location: In-Person Presentation, CDP Show/Hide Abstract The radiation shielding and dose attenuation capacity of six zinc-lithium-dysprosium borotellurite glass system having composition: (B2O3)0.2-(TeO2)0.3-x(ZnO)0.28–(Li2CO3)0.2– (Dy2O3)0.02-(WO3)x labeled as W1 to W6 for x value from 0.02 to 0.12 has been analysed. Shielding parameters like mass attenuation coefficient, linear attenuation coefficient, half value layer, tenth value layer, effective atomic number are estimated. Similarly, transport properties such as effective electron density, mean free path, effective conductivity have been analysed using Phy-X/PSD database in the energy range 1 keV to 100 GeV. Furthermore, fast neutron removal cross sections were calculated. The parameters like stopping potential and projected range of ions like proton, helium, and carbon in materials were calculated using Stopping and Range of Ions in Matter (SRIM) software package application. The trajectories and effective dose rate of photon was also evaluated using Particle and Heavy Ions Transport code System (PHITS). The obtained results show that sample W6(0.2B2-O3–0.3TeO2- 0.0336ZnO–0.2Li2CO3–0.02Dy2O3–0.12WO3) has better protective potential than rest five glass samples and comparable to other glasses that were previously studied and recommended for nuclear applications.
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Abstract Number: ANPA2025-N00081 Presenting Author: Ram Sharan Karki Co-Authors: nan Presenter's Affiliation: Tribhuvan University Title: Assessment of Uncertainty in Dose Measurement Using TLD-100 and Monte Carlo Methods Location: In-Person Presentation, CDP Show/Hide Abstract This study evaluates the uncertainties in radiation dose measurements using TLD-100 dosimeters (lithium fluoride crystal doped with magnesium and titanium and the Harshaw 6600 Plus TLD reader system) at the Nepal Academy of Science and Technology, Khumaltar, Nepal. LiF:Mg,Ti is widely used in thermoluminescent dosimetry due to its favorable properties, making it a preferred material for radiation monitoring in occupational, environmental, and medical contexts. The calibration of TLD-100 dosimeters and evaluation of uncertainties are done through both analytical and Monte Carlo approaches. The standard uncertainty of personal dose equivalent Hp(10) measurements, considering non-linear response, was found to be 0.123, with an expanded uncertainty of 0.164 mSv and a relative uncertainty of 16.122% (k = 1.96), while the combined relative uncertainty for generating calibration factors was 11.91%. When employing Monte Carlo methods, the standard uncertainty increased to 0.140, with an expanded uncertainty of 0.224 mSv and a relative uncertainty of 20.919%, resulting in a combined relative uncertainty of 13.46%. These results confirm that the dosimetry system meets international uncertainty standards, and the use of Monte Carlo methods contributes to improved accuracy in occupational dose assessments.
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Abstract Number: ANPA2025-N00078 Presenting Author: Num Prasad Acharya Co-Authors: Suresh Basnet; Amar Prasad Misra; Raju Khanal Presenter's Affiliation: Mr Title: DUST-ION-ACOUSTIC SOLITARY AND SHOCK WAVES FOR SATURN’S E-RING MAGNETIZED DUSTY PLASMA WITH q-NONEXTENSIVE ELECTRON DISTRIBUTION AND DUST CHARGE FLUCTUATIONS Location: In-Person Presentation, CDP Show/Hide Abstract DUST-ION-ACOUSTIC SOLITARY AND SHOCK WAVES FOR SATURN’S E-RING MAGNETIZED DUSTY PLASMA WITH q-NONEXTENSIVE ELECTRON DISTRIBUTION AND DUST CHARGE FLUCTUATIONS
Num Prasad Acharya1,2, Suresh Basnet1, Amar Prasad Misra3 and Raju Khanal1
1Central Department of Physics, Tribhuvan University, Kirtipur, Kathmandu 44613, Nepal
2Department of Physics, Mahendra Multiple Campus, Tribhuvan University, Ghorahi 22415, Dang, Nepal
3Department of Mathematics, Visva-Bharati (A Central University), Santiniketan-731 235, India
Email: numacharya@gmail.com
Abstract
We have investigated dust-ion acoustic solitary and shock waves in a magnetized dusty plasma and explored the features of solitary and shock waves in Saturn’s E-ring’s dusty plasma, in account of anisotropic ion pressure and dust charge fluctuations. The dust charge equation has been solved via Newton’s Raphson method. The modified damped KdV and Burger’s equations have been extended and analytically solved. In the case of space dusty plasma, we have taken the physical parameters relevant to Saturn’s E-ring and both compressive and rarefactive solitary and shock waves are evolved. The features of monotonic shock waves are significantly affected by the nonextensive parameter q, magnitude of magnetic field, obliqueness of wave propagation, anisotropic ion pressure, and size of dust grain as well. Furthermore, the dust charge fluctuation rate plays a crucial role in the study of shock wave evolution on Saturn’s E-ring dusty plasma.
References:
[1] A. P. Misra, Appl. Math. Comput., 256, 368–374 (2015).
[2] S. Ghosh, J. Plasma Phys., 71, 519–526 (2005).
[3] S. Bansal, M. Aggarwal, and T. S. Gill, Phys. Plasmas, 27, 083704 (2020).
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Abstract Number: ANPA2025-N00083 Presenting Author: Anup Shrestha Co-Authors: Amba Datt Pant; Hari Shankar Mallik; Anjan Dahal; Akihiro Koda; Katshuhiko Ishida; Burkhard Geil; Jumpei Nakamura; Shoichiro Nishimura; Hiromi Sakai; Koichiro Shimomura Presenter's Affiliation: Central Department of Physics, Tribhuvan University, Kathmandu, Nepal Title: A µSR study in oxyhemoglobin aqueous solutions Location: In-Person Presentation, CDP Show/Hide Abstract A low oxygen concentration in tumor tissue is known as hypoxia, which supports the progression of the tumor and resists the treatments [1,2]. To detect hypoxia, a non-invasive muon method has been proposed [3,4], which is expected to compensate for the current unavailability of such a method [5]. The development of the proposed muon method requires an organized muon spin rotation and relaxation (µSR) study of biomacromolecules. Oxyhemoglobin (OxyHb), a hemoglobin (Hb) derivative, transports oxygen (O2) from lungs to tissues and exhibits diamagnetism. Muon is similar to a proton with a lighter mass (mµ = 1/9 mp) and greater magnetic moment (µµ = 3.2 µp). It is an exotic magnetic probe sensitive to the magnetic field in the material. Muonium (Mu), a bound state of a muon and an electron (µ+e-), is like a light hydrogen isotope and directly interacts with O2. In this study, we performed ZF- and weak TF-µSR measurements in two concentrations (114.5 g/L and 5 g/L) of aqueous OxyHb solutions (purified from human blood) at temperatures ranging from 300 K to 140 K.
Isotropic Mu in liquid and axially symmetric anisotropic Mu in frozen phase are observed via concentration-dependent studies. In the liquid phase, in addition to the paramagnetic Mu, a diamagnetic muon species (H2O-Mu+-H2O) is observed, while in the frozen phase, two diamagnetic muon species (H2O-Mu+-H2O and MuOH) are observed, like in ice [6] and buffer [7]. The observed values of the Mu hyperfine transitions are in close approximation to the theoretically predicted values.
References
[1] M. C. Brahimi-Horn and J. Pouysségur, Journal of Molecular Medicine 85 (2007) 1301–1307.
[2] A. L. Harris, Nature Reviews Cancer 2, (2002) 38–47.
[3] A. D. Pant et. al., Journal of Physics: Conference Series 551(1), (2014) 012043.
[4] A. D. Pant et. al., Nuclear Instruments and Methods in Physics Research A 1011, (2021) 165561.
[5] J. P. B. O’Connor et al., Cancer Research 76, (2016) 787–795.
[6] A. D. Pant et al., Physical Review B 110, (2024) 104104.
[7] A. Dahal et al., oral presentation in this conference.
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