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Temperature Influence on the Optical Properties, Attenuation Coefficient, and Total Molecular Cross Section of Dhunge Dhara Drinking Water Dhobi, Saddam Husain; Koirala, Bibek; Yadav, Kishori; Nakarmi, Jeevan Jyoti; Gupta, Suresh Prasad; Das, Santosh Kumar; Shah, Arun Kumar; Paudel, Kuldip; Dahal, Kushal; Sah, Ram Lal
Makara Journal of Science Vol. 26, No. 4
Publisher : UI Scholars Hub

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Abstract

This work aims to measure the different parameters of Dhunge Dhara water (DDW) such as absorbance, transmittance, mass attenuation coefficient (MAC), and molecular cross section (MCS) and experimentally compare the obtained values with those of pure water (PW) at various temperatures (5 °C to 90 °C) using a theremino spectrometer. Observation shows that the parameters vary with temperature and wavelength. The transmittance of DDW ranges from 18% to 85% and absorbance of the same ranges from 0.09 Au to 0.7 Au. Meanwhile, the transmittance of PW ranges from 40% to 98% and the absorbance of the same ranges from 0.09 Au to 0.39 Au. The MAC of PW ranges from 0.02 cm2g−1 to 0.6 cm2g−1, and that for DDW ranges from 0.2 cm2g−1 to 1.1 cm2g−1 at 30 °C. The MCS of PW ranges from to , and that of DDW ranges from to at 30 °C. In conclusion, DDW has an extremely high amount of impurities and total dissolved solids and is recommended to be filtered prior to use (drinking and cooking)
Pair Correlation Influence on Superconductors Josephson Penetration Depth Poudel, Yadhav; Gupta, Suresh Prasad; Shrestha, Narayan Babu; Yadav, Kishori; Dhobi, Saddam Husain
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 1 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 1, April 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.091.02

Abstract

The Josephson penetration depth is an essential characteristic of Josephson junctions, serving a role akin to the London penetration depth in bulk superconductors. It originates from the substantial self-magnetic field generated by a strong Josephson supercurrent, influencing the distribution of the gauge invariant phase difference across the junction. This study delves into the intricate relationship between cooper pair correlation and critical temperature in superconductors. To study relationships authors develop theoretical method and observed that critical temperature exhibits a noteworthy decrease with an increase in cooper pair correlation. Specifically, as the level of coherence among electron pairs rises, the material's capacity to maintain the superconducting state at elevated temperatures is enhanced, resulting in an elevated critical temperature. Conversely, regions characterized by lower pair correlation demonstrate a sharp reduction in critical temperature, indicating their heightened susceptibility to changes in correlation levels. This sensitivity is particularly pronounced across junction and penetration depth where cooper pair correlation is diminished. Furthermore, the study reveals an exponential decay trend in critical temperature concerning cooper pair correlation, underscoring the pivotal role played by pair correlation in the superconducting state. Even slight alterations in pair correlation have a substantial impact on the material's ability to exhibit superconductivity. These findings provide valuable insights for the tailored design and optimization of superconducting materials for specific applications. By leveraging the understanding gained from this research, it becomes possible to engineer materials with enhanced superconducting properties. This study not only advances our fundamental comprehension of superconductivity but also offers practical implications for a diverse range of technological applications.
Laser-Assisted Scattering with Screened Diatomic Potential Sapkota, Asmit; Dhobi, Saddam Husain; Khatiwada, Subash
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 3 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 3, December 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.093.01

Abstract

This study explores the differential cross section (DCS) for laser-assisted scattering of diatomic molecules, considering various polarization conditions (linear, circular, elliptical) and potential parameters. The primary objective is to understand how polarization, screening effects, and potential parameters influence the scattering behavior. Utilizing a model that incorporates the Morse potential with screening effects, the analysis treats the laser field classically as a time-dependent, spatially homogeneous electric field, while the electron dynamics are described quantum mechanically using the Schrödinger equation. The Volkov wavefunction is derived, and the first-Born S-matrix element is computed to evaluate the scattering process. The results show that the DCS decreases with increasing screening parameters, with linear polarization yielding higher values than circular or elliptical polarization. Specifically, at an initial momentum of 8 MeV and a final momentum of 9 MeV, the DCS for elliptical polarization is notably higher. The DCS also varies with potential strength and well width, showing a peak at 0.14 Å for potential well width. The findings suggest that linear polarization is most effective for scattering studies under varying potential strengths. It is recommended to focus on linear polarization for enhanced scattering efficiency and to carefully adjust screening parameters and potential well widths for optimal results.
Phase Dynamics in 3D Superconductors: Analysis Using the Sine-Gordon Khadka, Kiran; Dhobi, Saddam Husain; Yadav, Kishori
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 3 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 3, December 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.093.02

Abstract

This study investigates the phase dynamics of superconducting states in 3D superconductors using the sine-Gordon equation, with a focus on the interplay between the London penetration depth (LPD) and coherence length ( ). The research employs a combination of analytical modeling and simulation techniques to explore how variations in LPD influence phase behavior across different coherence lengths in the developed model. At a critical coherence length of  = 2 Å, the LPD decreases from 150 nm to 120 nm as the nanoparticle spacing increases from 5 nm to 10 nm, attributed to reduced interactions between superconducting states. Conversely, at  = 1 Å, quantum confinement effects lead to non-linear LPD behavior, with an initial decrease from 180 nm to 160 nm followed by an increase to 200 nm as nanoparticle spacing changes. In 3D superconductors, phase evolution is characterized by distinct waveforms—square, rectangular, and mixed—corresponding to LPD values between 100 nm and 200 nm, with phase shifts ranging from 1° to 20°. Smaller phase shifts (1°) produce higher-frequency oscillations with amplitudes up to 0.2, while larger shifts (20°) generate broader, less intense waveforms. These findings underscore the critical role of LPD in determining superconducting properties, offering valuable insights for the design and optimization of superconducting devices to enhance performance and efficiency.
Theoretical Study of Positron-Electron Scattering with Thermal-Volkov Wavefunction KC, Narayan; Gupta, Suresh Prasad; Yadav, Kishroi; Dhobi, Saddam Husain
Spektra: Jurnal Fisika dan Aplikasinya Vol. 10 No. 2 (2025): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 10 Issue 2, August 2025
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.102.01

Abstract

This study investigates the differential cross-section (DCS) for laser-assisted positron-electron scattering in a Gaussian wave packet, within a linearly polarized laser field in a thermal environment. For this, a theoretical model was developed with a designed thermal Gaussian Volkov wavefunction, vector potential, and scattering matrix with the application of the Bessel function.  The developed model was computed using the Matlab programming language to study the nature of the developed model of DCS. The observation shows that the DCS initially increases with positron energy, reaching a peak around 0.5 eV; after that, it decreases with further increases in energy and approaches a constant at high energies. This is due to changing dynamics of positron-electron interactions with resonance occurring at specific energies. Also, the observation shows that temperature plays a significant role, especially at lower energies, with higher temperatures (325 K) enhancing the DCS due to increased thermal excitation of the target electrons. The study also explores the influence of the  z-value and found that higher z-values lead to a decrease in the DCS due to the Coulombic interaction becoming stronger. Moreover, the effects of external factors such as the number of laser field photons and pulse duration are considered. The observation shows that shorter laser pulse durations and higher photon energies enhance the scattering process, while longer pulse durations result in a decrease in DCS. This study aids in optimizing technologies like PET imaging, plasma diagnostics, and particle accelerators by revealing how positron-electron scattering varies with energy, temperature, and laser parameters. It supports real-world applications in medical, space, and materials science.