Journal of Theoretical and Applied Physics (JTAP)Photodynamic Activation using Herbal Extract and Low-Power Laser against Gram-Positive (Streptococcus mutans) and Gram-Negative (Klebsiella pneumoniae) Bacteria: Threats and Resistance MechanismsVolume 18 (2024)Issue 4, July & August 202420240813Photodynamic Activation using Herbal Extract and Low-Power Laser against Gram-Positive (Streptococcus mutans) and Gram-Negative (Klebsiella pneumoniae) Bacteria: Threats and Resistance Mechanisms10.57647/j.jtap.2024.1804.46ENZahraAghaEbrahimiDepartment of Physics, Central Tehran Branch, Islamic Azad University, Tehran, IranJamshidSabaghzadehDepartment of Physics, Central Tehran Branch, Islamic Azad University, Tehran, Iran0000-0002-0055-7875SasanSoudiDepartment of Medical Engineering, Faculty of Health and Medical Engineering, Tehran Medical Sciences0000-0002-5558-2867MohamadRezaTanhayi AhariDepartment of Physics, Central Tehran Branch, Islamic Azad University, Tehran, Iran0000-0003-0907-4842Journal Article20240813
This paper investigates the efficacy of photodynamic activation (PDA) using herbal extract in combination with low-power laser treatment against both Gram-positive (Streptococcus mutans) and Gram-negative (Klebsiella pneumoniae) bacteria. The study explores the threats posed by these bacteria and highlights their resistance mechanisms. Various experiments, including colony formation assays, minimal inhibitory concentration tests, and bacterial viability assays, were conducted to assess the antibacterial effects of PDA in the presence and absence of laser irradiation. Additionally, spectroscopic analysis of the herbal extract was performed to elucidate their composition and potential synergistic interactions with PDA. Journal of Theoretical and Applied Physics (JTAP)Enhancing Cell Growth with PAN/PVA-Gelatin 3D Scaffold using In-situ UV Radiation Electrospinning and Plasma TreatmentVolume 18 (2024)Issue 4, July & August 202420240813Enhancing Cell Growth with PAN/PVA-Gelatin 3D Scaffold using In-situ UV Radiation Electrospinning and Plasma Treatment10.57647/j.jtap.2024.1804.47ENRahimehKhavariDepartment of Cell & Molecular Biology, Faculty of Life Sciences & Biotechnology, Shahid Beheshti University, Tehran, Iran0000-0002-4043-1441SaeedJavadi AnaghiziLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran0000-0003-2801-1724AhmadKhademiLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran0000-0002-0411-6444MehdiJahanfarDepartment of Cell & Molecular Biology, Faculty of Life Sciences & Biotechnology, Shahid Beheshti University, Tehran, Iran0000-0002-7247-2344ShirinFarivarDepartment of Cell & Molecular Biology, Faculty of Life Sciences & Biotechnology, Shahid Beheshti University, Tehran, Iran0000-0002-3277-1163HamidGhomiLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran0000-0003-2203-5194Journal Article20240813
The hydrophobic nature of synthetic polymers poses a substantial barrier since it limits cell-seeding and proliferation scaffold performance. To overcome this challenge, the present research attempts to employ in-situ UV electrospinning and plasma surface modification techniques to fabricate a three-dimensional PAN/PVA-gelatin scaffold. The proposed scaffold holds great potential in mitigating hydrophobicity limitations, thereby facilitating enhanced cell adhesion and proliferation.
The SEM results indicated that exposure to UV irradiation resulted in the formation of wavy shapes in the PAN microstructures and crosslinking between fibers within the scaffold. Moreover, plasma treatment induced the formation of pores on the PAN surface, with an average diameter of 43 μm, corresponding to the size range of mouse fibroblast cells. Furthermore, the plasma treatment provided roughness augmentation of the scaffold surface, which played a crucial role in enhancing cell adhesion and elongation on the modified scaffold surface. Comparatively, the plasma-modified scaffolds exhibited a higher proportion of viable cells than the unmodified scaffolds (p<0.05). Moreover, the implementation of perforations in the PAN layer via plasma treatment reduced the number of necrosis cells in comparison to the other samples. In contrast, the unmodified scaffold showed a higher percentage of apoptosis cells (p<0.05).
Journal of Theoretical and Applied Physics (JTAP)A Comparative Study on Predicting the Characteristics of Plasma Activated Water: Artificial Neural Network (ANN) & Support Vector Regression (SVR)Volume 18 (2024)Issue 4, July & August 202420240813A Comparative Study on Predicting the Characteristics of Plasma Activated Water: Artificial Neural Network (ANN) & Support Vector Regression (SVR)10.57647/j.jtap.2024.1804.48ENSaeedKarimianDepartment of Physics, Vali-e-Asr University of Rafsanjan, Rafsanjan, IranShahrzadFalahatFaculty of Physics, Shahid Bahonar University of Kerman, Kerman, IranZahraEmam BakhshDepartment of Physics, Vali-e-Asr University of Rafsanjan, Rafsanjan, IranMohammadJavad Ghavami RadFaculty of Sciences, Center branch of Tehran, Islamic Azad University, Tehran, IranAliBarkhordariFaculty of Physics, Shahid Bahonar University of Kerman, Kerman, Iran0000-0002-5523-2859Journal Article20240813In this paper, the applicability of the Machine Learning (ML) technique in predicting the structural characteristics of water exposed by the plasma discharge is studied. For this purpose, the structural characteristics of water including pH, Electrical Conductivity (EC), Oxidation Reduction Potential (ORP), Total Dissolved Solution (TDS), and salt is experimentally measured before and after exposing the plasma. The plasma discharge medium consists of air and water. The applied voltage and the time duration of plasma application are considered as operational variables. Also, Support Vector Regression (SVR), as a strong algorithm of Machine Learning (ML), is applied on the data to train a model for accurately predicting the water characteristics as the new data. It is shown that pH value is reduced at higher applied voltages and time of plasma treatment while EC, ORP, TDS, and salt are increased. It was also found that the SVR model can predict the main characteristics of water with a high R2 score of 0.998. The results obtained by SVR in the prediction of water characteristics are compared with the performance of Artificial Neural Network (ANN) as another interesting ML algorithm, showing the better performance of the SVR algorithm than ANN one.Journal of Theoretical and Applied Physics (JTAP)Plasma Surface Interaction for Constant Mean Free PathVolume 18 (2024)Issue 4, July & August 202420240813Plasma Surface Interaction for Constant Mean Free Path10.57647/j.jtap.2024.1804.49ENRajatDhawanPlasma Science and Technology Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India0000-0002-7673-0144SarikaDepartment of Physics, MM Engineering College, Maharishi Markandeshwar, Mullana-Ambala, Haryana, India0009-0006-6599-3885RajeevSehrawatDepartment of Physics, MM Engineering College, Maharishi Markandeshwar, Mullana-Ambala, Haryana, India0000-0002-1355-7786RashmiMittalDepartment of Physics, MM Engineering College, Maharishi Markandeshwar, Mullana-Ambala, Haryana, India0000-0002-9487-2082IshanChoudharyDepartment of Physics, MM Engineering College, Maharishi Markandeshwar, Mullana-Ambala, Haryana, India0000-0001-6032-737XJournal Article20240813In the present work, plasma surface interaction for constant mean free path has been investigated by choosing a three-component electronegative warm plasma where electrons are described by non-extensive statistics, and both negative and positive ions by fluid approach. Here, the finite value of ion-neutral collisions, the temperature of negative and positive ions, the mass of negative ions, and negative ion density have been considered to uncover the realistic situation. We have considered CF4 electronegative plasma where CF3+ and F- are the dominant charged species formed. The influence of electronegativity and positive ion temperature on positive ion velocity, positive ion density, electric potential, and net space charge density have been analysed to uncover the realistic situation. The plasma sheath profile has been investigated for the very first time using this combination of charged species distribution.Journal of Theoretical and Applied Physics (JTAP)Preparing and Synthesizing Modified Electrospun Nanofibers via Online UV Method from Poly Acrylonitrile and Poly Vinyl Alcohol for Enzyme (glucose oxidase) IimmobilizationVolume 18 (2024)Issue 4, July & August 202420240813Preparing and Synthesizing Modified Electrospun Nanofibers via Online UV Method from Poly Acrylonitrile and Poly Vinyl Alcohol for Enzyme (glucose oxidase) Iimmobilization10.57647/j.jtap.2024.1804.50ENSepidehAsadiFaculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran0000-0003-0400-5071MehdiJahanfarFaculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran0000-0002-7247-2344SaeedJavadi AnaghiziCentral Laboratory of Shahid Beheshti University, Tehran, Iran0000-0003-2801-1724DariushMinai-TehraniFaculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran0000-0003-3589-7324Journal Article20240813The study explores the use of nanofibers for enzyme immobilization, leveraging their high contact area and controlled cavities. By employing ultraviolet (UV) irradiation on a polymeric blend of polyvinyl alcohol (PVA) and poly acrylonitrile (PAN) during electrospinning, nanofibers were fabricated for glucose oxidase (GOD) immobilization. UV treatment enhanced carboxyl group presence on nanofiber surfaces, as confirmed by Fourier transform infrared (FTIR) analysis. Enzyme activity assessments demonstrated a 33% increase in immobilized enzyme activity when PVA content in the nanofibers was raised from 1% to 3%. Scanning electron microscopy (SEM) images revealed that UV treatment helped maintain nano filament structures post-immobilization, aiding enzyme retention and controlled release. Atomic force microscopy (AFM) images displayed increased roughness in UV-treated nanofibers. The study showcased GOD reusability up to 12 cycles in 3% PVA-containing samples.Journal of Theoretical and Applied Physics (JTAP)One-dimensional Study of Spatiotemporal Evolution of Magnetic Field by Weibel Instability in Counter-streaming Plasma FlowsVolume 18 (2024)Issue 4, July & August 202420240813One-dimensional Study of Spatiotemporal Evolution of Magnetic Field by Weibel Instability in Counter-streaming Plasma Flows10.57647/j.jtap.2024.1804.51ENRakeshKumarPlasma Waves and Particle Acceleration Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi, India0009-0007-1218-0861HitendraK MalikPlasma Waves and Particle Acceleration Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi, India0000-0002-9432-8140SandeepKumarPlasma Waves and Particle Acceleration Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi, India0000-0003-1681-7085Journal Article20240813The plasma filamentation instability (FI), also known as the beam-Weibel instability, is responsible for the generation of magnetic fields and the acceleration of particles within collisionless astrophysical plasmas. In the present study, we employ Particle-In-Cell (PIC) simulation to model the filamentation instability driven by sub-relativistic electron-positron counter-streaming pairs in one spatial dimension moving with velocity . The temperature is taken to be hotter in one direction. The simulation box is aligned in y-direction (perpendicular to the beam velocity vector) with normalized length . The magnetic field is found to grow unconstrainedly and causes the particles to reorganize in space. Our findings have revealed that the magnetic pressure gradient that forms during the quasilinear evolution of the filamentation instability results in generating an electrostatic field component and both the electrostatic field and the magnetic field act to redistribute the particles within the spatial domain. The electromagnetic fields lead to the thermalization of the electrons. The filamentation instability exhibits effective mechanisms for accelerating electrons to high energy levels.Journal of Theoretical and Applied Physics (JTAP)Effect of Gas Pressure on Plasma Characteristics of a 2.45 GHz ECR Iion SourceVolume 18 (2024)Issue 4, July & August 202420240813Effect of Gas Pressure on Plasma Characteristics of a 2.45 GHz ECR Iion Source10.57647/j.jtap.2024.1804.52ENMarziehAsadi AghbolaghiDepartment of Radiation Application, Faculty of Nuclear Engineering, Shahid Beheshti University, Tehran, Iran0009-0009-0342-7118FereydounAbbasi DavaniDepartment of Radiation Application, Faculty of Nuclear Engineering, Shahid Beheshti University, Tehran, Iran0000-0002-3175-3449MasoomehYarmohammadi SatriPhysic and Accelerators Research School, Nuclear Science and Technology Research Institute, Tehran, IranZafarRiazi MobarakiPhysic and Accelerators Research School, Nuclear Science and Technology Research Institute, Tehran, IranFarshadGhasemiPhysic and Accelerators Research School, Nuclear Science and Technology Research Institute, Tehran, IranJournal Article20240813Electron cyclotron resonance ion source (ECRIS) is designed and simulated using COMSOL software. The 2.45 GHz microwave is injected through a coaxial cable into a cylindrical chamber with a diameter of 9 cm and a length of 10 cm. Two coils are employed to produce a flat-B magnetic field profile and two resonance zones on both sides of the chamber. Hydrogen gas plasma is simulated by considering H2, H2+ and H3+ ions, and H and H2 as neutrals. Finally, electron density and temperature are reported as a function of gas pressure. It is observed that as the gas pressure increases, the electron temperature decreases and the electron density decline following an initial increases.Journal of Theoretical and Applied Physics (JTAP)Adjusting the Operation Frequency of Cantilever Based Magnetoelectric SensorVolume 18 (2024)Issue 4, July & August 202420240813Adjusting the Operation Frequency of Cantilever Based Magnetoelectric Sensor10.57647/j.jtap.2024.1804.53ENMeisamHaghparastLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran0000-0001-8523-3732MohammadMehdi TehranchiLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran
Department of Physics, Shahid Beheshti University, Tehran, Iran0009-0004-0713-7576SeyedehMehri HamidiLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran0000-0002-5298-2224Journal Article20240813Magnetoelectric sensors, based on magnetostrictive-piezoelectric composites, exhibit the highest sensitivity at electromechanical resonance frequencies. Consequently, adjusting the operation frequency of these sensors for various applications becomes crucial. Using comprehensive simulations based on the finite element method, different structures can be investigated to obtain the operation frequency, magnetoelectric coefficient, and sensitivity. The structures used comprise FeGa/AlN/Silicon sandwich composites in a cantilever-type configuration with the etched silicon substrate. The thickness and etching method of the substrate exert an effect on the mentioned parameters; hence, the operation frequency of these sensors can be adjusted by structural engineering.
Furthermore, this approach enables the identification of optimal structures for applications such as biosensors and energy harvesting. The proposed structure of lower operation frequency exhibits a magnetoelectric coefficient of 3622 V/cm.Oe at a resonance frequency of 965 Hz with a sensitivity of 11.0 . Subsequently, the superior proposed structure in terms of a magnetoelectric coefficient has 5120 V/cm.Oe at a resonance frequency of 1783 Hz, demonstrating a sensitivity of 3.9 .Journal of Theoretical and Applied Physics (JTAP)Athermalization of a Type of Fisheye Optical System in the Temperature Range of IranVolume 18 (2024)Issue 4, July & August 202420240813Athermalization of a Type of Fisheye Optical System in the Temperature Range of Iran10.57647/j.jtap.2024.1804.54ENYasinZakerinasabDepartment of Physics, Faculty of Sciences, University of Hormozgan, Bandar Abbas, Iran0009-0009-6468-912XAliRezaei-LatifiDepartment of Physics, Faculty of Sciences, University of Hormozgan, Bandar Abbas, Iran0000-0002-4231-7861Journal Article20240813The fisheye system belongs to the family of ultra-wide field of view lenses and has various applications in science, industry, surveillance and artistic fields. Such lenses can cover a field of view of 180 degrees or even larger in the shape of a hemisphere, and therefore can provide the possibility of imaging a large part of the surrounding space with just one shot. Due to the wide temperature changes in Iran, the optical performance of this system is significantly reduced under the influence of the change in the radius and thickness of the surfaces and the change in the refractive index of its glasses. Therefore, in order to achieve optical-thermal stability in the temperature range of Iran, it is necessary to athermalize the system so that temperature changes do not cause a noticeable decrease in the optical performance of the system. In this work, a type of fisheye optical system is redesigned in the visible light spectrum bandwidth and then it is athermalized in the temperature range of Iran from -46 to 70 degrees Celsius.Journal of Theoretical and Applied Physics (JTAP)Innovative Applications of Rotaxane-Based Molecular Junctions in Electronics and OptoelectronicsVolume 18 (2024)Issue 4, July & August 202420240813Innovative Applications of Rotaxane-Based Molecular Junctions in Electronics and Optoelectronics10.57647/j.jtap.2024.1804.55ENHibaAbbas MohammedDepartment of Laser Physics, College of Science for Women, University of Babylon, Hilla, Iraq0009-0006-8699-035XOdayA. Al-OwaediDepartment of Laser Physics, College of Science for Women, University of Babylon, Hilla, Iraq0000-0003-0721-0409HusseinNeama NajeebDepartment of Laser Physics, College of Science for Women, University of Babylon, Hilla, Iraq0009-0006-8810-9175Journal Article20240813This study examines the effect of aromatic ring numbers on electronic and transport properties in rotaxane molecular junctions using density functional theory (DFT) calculations. Five rotaxane molecules (R-1 to R-5) with varying ring counts (1 to 5) and 149 (R-1) to 422 (R-5) atoms. Our results showed that the ring count significantly influenced properties like as band gap, fermi energy, binding energy and so on. The HOMO-LUMO gap decreased from -1.14 eV to -1.05 eV for R-1 and R-5 respectively which indicating improved conductivity. Electron transfer increased from 1.6×10⁻⁴ in R-1 structure to 2.3×10⁻³ in R-5 from transmission coefficient and the impact of ring count was consistent across different temperatures. Electrical conductance (G/G₀) followed a similar trend, increasing from 1.5×10⁻⁴ (R-1) to 2.2×10⁻³ (R-5) with Fermi energy. Threshold voltage (Vth) and seebeck coefficient (S) decreased with more rings in opposite manner and finally the Binding energy (B.E.) exhibited non-monotonic behavior. This study underscores the significant influence of aromatic ring count on electronic and transport properties in rotaxane molecular junctions, informing the design of molecular structures for drug delivery.