Brazilian Journal of Physics最新文献

筛选
英文 中文
Harnessing X-Ray Photons to Engineer Graphene Oxide: Novel Approaches and Future Directions 利用x射线光子来设计氧化石墨烯:新方法和未来方向
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-24 DOI: 10.1007/s13538-025-01797-8
Itishree Mohanty,  UshaRaniPal, Kshmasagar Jena, Kamal Lochan Mohanta, Chhatrapati Parida
{"title":"Harnessing X-Ray Photons to Engineer Graphene Oxide: Novel Approaches and Future Directions","authors":"Itishree Mohanty,&nbsp; UshaRaniPal,&nbsp;Kshmasagar Jena,&nbsp;Kamal Lochan Mohanta,&nbsp;Chhatrapati Parida","doi":"10.1007/s13538-025-01797-8","DOIUrl":"10.1007/s13538-025-01797-8","url":null,"abstract":"<div><p>The research elucidates the economical and eco-friendly synthesis of modified graphene oxide utilizing X-rays generated from medical linear accelerators employed in oncology facilities, examining multiple viewpoints. Graphene oxide (GO) synthesized from graphite using Hummers method was subjected to X-ray photon treatment having doses of 2.0 Gy, 6.0 Gy, 8.0 Gy, 10.0 Gy, and 20.0 Gy, resulting in the formation of “X-ray-modified GO.” The X-ray -modified GO was examined using X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, and TGA to ascertain the specific alterations induced by the X-ray treatment. The distinctiveness of our study resides in the utilization of exceptionally low dosage X-ray (2.0 to 20 Gy) at 6 MV energy, a method not employed by any other investigation. The transition from three-dimensional (3D) GO to multilayered graphene was evaluated by analyzing variations in the relative strength of the G and D peaks of X-ray-modified GO and the emergence of the 2D Raman peak. The Raman and XRD spectra are utilized to investigate the impact of X-ray irradiation on crystallite dimensions and interplanar spacing. The findings from XRD, FTIR, and Raman analyses are consistent and demonstrate the elimination of several oxygen-containing functional groups from GO upon exposure to X-ray radiation, suggesting a molecular interaction between GO and X-ray photons. The derivative TGA graphs exhibit unique peaks at temperatures corresponding to maximal mass decomposition rates within particular ranges, indicating reduction resulting from X-ray treatment. The realized materials have the potential for application in electrical engineering, electronics, wastewater treatment, and biomedical domains.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Investigating Reaction Kinetics of Crystallization Mechanism in Se78-xTe20Sn2Inx (x = 0, 2, 4, 6) Chalcogenide Glasses (ChGs): Insights into Compositional Effects Se78-xTe20Sn2Inx (x = 0,2,4,6)硫系玻璃(ChGs)结晶机理的反应动力学研究:组分效应的见解
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-24 DOI: 10.1007/s13538-025-01788-9
Kaushal Kumar Sarswat, Sangeeta Singh, Neeraj Mehta
{"title":"Investigating Reaction Kinetics of Crystallization Mechanism in Se78-xTe20Sn2Inx (x = 0, 2, 4, 6) Chalcogenide Glasses (ChGs): Insights into Compositional Effects","authors":"Kaushal Kumar Sarswat,&nbsp;Sangeeta Singh,&nbsp;Neeraj Mehta","doi":"10.1007/s13538-025-01788-9","DOIUrl":"10.1007/s13538-025-01788-9","url":null,"abstract":"<div><p>This study investigates the crystallization kinetics of Se<sub>78−x</sub>Te<sub>20</sub>Sn<sub>2</sub>In<sub>x</sub> (<i>x</i> = 0, 2, 4, 6) chalcogenide glasses (ChGs) under non-isothermal conditions to evaluate the effects of indium incorporation. Differential scanning calorimetry (DSC) was performed at 5–20 K/min heating rates. Kinetic parameters were extracted using iso-conversional methods, including Kissinger–Akahira–Sunose (KAS) and Vyazovkin–Horner–Rogers (VHR) approaches. Results revealed that In doping significantly alters thermal stability and crystallization dynamics. STSI-1 (<i>x</i> = 2) exhibited the highest initial activation energy (230.0 kJ/mol), which decreased by 48.29%, indicating a marked reduction in crystallization resistance. In contrast, the undoped sample (STS) showed only a 20.3% drop. The Avrami index (<i>n</i>) and enthalpy of crystallization (<i>ΔH</i>) were also highest in STSI-1, suggesting altered nucleation-growth mechanisms and higher energy demand. In-doped samples showed lower crystallization temperatures (<i>T</i><sub><i>c</i></sub>), implying enhanced crystallization efficiency. A correlation between ln <i>K</i><sub><i>0</i></sub> and <i>E</i><sub><i>a</i></sub> supported the Meyer-Neldel rule (MNR) and iso-kinetic relationship (IKR), confirming consistent kinetic behavior. These findings highlight the critical role of composition in tuning the crystallization behavior of STSI glasses for potential phase-change and thermal management applications.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Erbium Substituted Mn-Cu Ferrite Nanoparticles: Synthesis, Structural, Magnetic, and Antimicrobial Activity Properties 铒取代锰铜铁氧体纳米颗粒:合成、结构、磁性和抗菌活性
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-22 DOI: 10.1007/s13538-025-01784-z
N. I. Abu-Elsaad, Rabab A. Metwally, A. S. Nawara
{"title":"Erbium Substituted Mn-Cu Ferrite Nanoparticles: Synthesis, Structural, Magnetic, and Antimicrobial Activity Properties","authors":"N. I. Abu-Elsaad,&nbsp;Rabab A. Metwally,&nbsp;A. S. Nawara","doi":"10.1007/s13538-025-01784-z","DOIUrl":"10.1007/s13538-025-01784-z","url":null,"abstract":"<div><p>In this study, the citrate–nitrate auto combustion process was used to create spinel ferrite nanoparticles <i>Mn</i><sub><i>0.5</i></sub><i>Cu</i><sub><i>0.5</i></sub><i>Er</i><sub><i>x</i></sub><i>Fe</i><sub><i>2−x</i></sub><i>O</i><sub><i>4</i></sub>, where 0.0 ≤ <i>x</i> ≤ 0.075. An analysis was conducted to evaluate the influence of erbium doping on the antimicrobial, microstructural, morphological, and magnetic possessions. A pure single-phase cubic structure is revealed by the structural study of the produced samples with Er doping, but the second phase emerges at <i>x</i> = 0.075. Results show that the lattice parameter grows with incorporating Er<sup>3+</sup> concentration up to <i>x</i> = 0.06, after which it starts to drop at <i>x</i> = 0.075, which lies between 8.432 and 8.446 Å. The TEM pictures revealed nanoscale dimensions and a cubic spinel structure. A rise in the Er<sup>3+</sup> content in Mn-Cu nanoferrites caused a dramatic variation in the magnetic properties. The coercivity varied from 93.60 to 114.89 G, whereas the saturation magnetization (ranging from 54.83 to 40.42 emu/g) and remanence (from 11.57 to 7.61 emu/g) showed a general decreasing trend. The results of the microwave frequency measurements show that ferrites can be used in wireless communication technology. The evaluation of the antimicrobial efficacy of MCEF nanoparticles against pathogenic microorganisms, including <i>Bacillus cereus</i>, <i>Staphylococcus aureus</i>, <i>Pseudomonas aeruginosa</i>, <i>Fusarium oxysporum</i>, <i>Aspergillus flavus</i>, <i>A. terreus</i>, <i>A. fumigatus</i>, <i>A. niger</i>, and <i>Rhizopus </i>sp., demonstrated that MCF nanoparticles doped with erbium at concentrations of 0.03 and 0.075 exhibit enhanced inhibitory effects on the growth of all aforementioned microorganisms. The highest inhibition was observed at an erbium concentration of 0.075, with a mean crystallite size of 39.16 nm, surpassing the inhibition at 0.03 concentration, which had an average size of 49.36 nm, in comparison to the undoped nanoparticles. The microbiological studies demonstrate that these nanoparticles may serve as a prospective antimicrobial agent with reduced effects on <i>P. aeruginosa</i>.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13538-025-01784-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Correction: Investigation of the Dependence of the Superconducting Critical Temperature of Hg-1201 on the Crystal Lattice c/a Ratio Under Ambient and High-Pressure Conditions 修正:环境和高压条件下Hg-1201超导临界温度与晶格c/a比关系的研究
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-22 DOI: 10.1007/s13538-025-01801-1
Abdullo Ahadov, Davron Dzhuraev
{"title":"Correction: Investigation of the Dependence of the Superconducting Critical Temperature of Hg-1201 on the Crystal Lattice c/a Ratio Under Ambient and High-Pressure Conditions","authors":"Abdullo Ahadov,&nbsp;Davron Dzhuraev","doi":"10.1007/s13538-025-01801-1","DOIUrl":"10.1007/s13538-025-01801-1","url":null,"abstract":"","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Modulational Instability of Dust-Ion-Acoustic Modulated Envelope Structures in Ultracold Quantum Complex Plasmas: Solitons, Rogue Waves, and Breathers 超冷量子复合等离子体中尘埃-离子-声学调制包络结构的调制不稳定性:孤子、异常波和呼吸子
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-20 DOI: 10.1007/s13538-025-01790-1
Haifa A. Alyousef, Fazal Wahed,  Ata-ur-Rahman, S. Neelam Naeem, Samir A. El-Tantawy
{"title":"Modulational Instability of Dust-Ion-Acoustic Modulated Envelope Structures in Ultracold Quantum Complex Plasmas: Solitons, Rogue Waves, and Breathers","authors":"Haifa A. Alyousef,&nbsp;Fazal Wahed,&nbsp; Ata-ur-Rahman,&nbsp;S. Neelam Naeem,&nbsp;Samir A. El-Tantawy","doi":"10.1007/s13538-025-01790-1","DOIUrl":"10.1007/s13538-025-01790-1","url":null,"abstract":"<div><p>In this study, we use a one-dimensional quantum hydrodynamic model to investigate the dynamics of amplitude-modulated dust ion-acoustic waves (DIAWs) in an ultracold, three-component quantum complex plasma composed of inertialess electrons, inertial ions, and immobile negatively charged dust particles. A nonlinear Schrödinger equation (NLSE) is reduced from the set of fluid equations via the reductive perturbation technique. The dispersion relation and group velocity are found to depend upon the wave number and related plasma parameters (i.e., the quantum diffraction parameter and dust concentration). It is noted that dispersion and nonlinear coefficients vary with wave number and parametric values of plasma. We thoroughly examined the modulational instability (MI) calculated from the NLSE, finding that dust concentration and the diffraction parameter significantly influence the conditions for the MI. Based on the MI criteria and relevant physical plasma parameters, the regions of stability and instability are carefully identified. Furthermore, we explored nonlinear modulated structures such as bright-type envelopes (pulses), dark-type envelope solitons (holes or voids), breathers, and rogue waves, which can propagate in both stable and unstable regions.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144100295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Novel Approximation to the Fractional KdV Equation Using the Tantawy Technique and Modeling Fractional Electron-Acoustic Cnoidal Waves in a Nonthermal Plasma 利用Tantawy技术对分数阶KdV方程的一种新的近似和模拟非热等离子体中的分数阶电子声余弦波
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-19 DOI: 10.1007/s13538-025-01780-3
Samir A. El-Tantawy, Daud Khan, Wilayat Khan, Muhammad Khalid, Weaam Alhejaili
{"title":"A Novel Approximation to the Fractional KdV Equation Using the Tantawy Technique and Modeling Fractional Electron-Acoustic Cnoidal Waves in a Nonthermal Plasma","authors":"Samir A. El-Tantawy,&nbsp;Daud Khan,&nbsp;Wilayat Khan,&nbsp;Muhammad Khalid,&nbsp;Weaam Alhejaili","doi":"10.1007/s13538-025-01780-3","DOIUrl":"10.1007/s13538-025-01780-3","url":null,"abstract":"<div><p>In this neoteric study, the fractional and non-fractional electron-acoustic (EA) cnoidal waves (CWs) are investigated in an unmagnetized homogeneous non-Maxwellian plasma composed of hot nonthermal electrons following Cairns distribution, cold electrons, and immobile positive ions. To do this, an evolution wave equation (Korteweg-de Vries (KdV) equation) that governs the propagation of these waves in the current model is generated by using the reductive perturbation technique. Analysis of the KdV equation’s nonlinearity coefficient, which dictates the polarity of nonlinear waves that may emerge and propagate in the current model, reveals that this model only supports rarefactive waves. The impact of various plasma parameters, like the nonthermal parameter and the density ratio of hot-to-cold electrons (hot electron concentration), on the essential features of the EACWs is numerically examined. The second objective of this investigation is to explore the fractional-order parameter’s effect on the dynamics of periodic wave propagation within the current model. This is achieved by transforming the non-fractional planar KdV equation into its fractional counterpart and analyzing it using contemporary methods, such as the Tantawy technique, which has proven its efficacy and precision in numerous prior studies.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144091057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Exclusive (J/Psi ) and (rho ^0) Vector Meson Production Using BK Evolution Theory 独家(J/Psi )和(rho ^0)矢量介子生产利用BK进化理论
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-17 DOI: 10.1007/s13538-025-01793-y
Ranjan Saikia, Jayanta Kumar Sarma
{"title":"Exclusive (J/Psi ) and (rho ^0) Vector Meson Production Using BK Evolution Theory","authors":"Ranjan Saikia,&nbsp;Jayanta Kumar Sarma","doi":"10.1007/s13538-025-01793-y","DOIUrl":"10.1007/s13538-025-01793-y","url":null,"abstract":"<div><p>Exclusive diffractive processes, such as exclusive vector meson production, serve as excellent probes of hadron structure within the perturbative regime of quantum chromodynamics (QCD). The exclusive process involving light and heavy vector mesons, <span>(e p rightarrow e V(V=J/Psi ,rho ,phi ))</span>, has been investigated at the HERA accelerator facility. In this study, we focus on the theoretical prediction of exclusive <span>(J/Psi )</span> and <span>(rho ^0)</span> vector meson production. Employing the color dipole formalism for the study of the exclusive vector meson production in photon-proton interactions, we calculate both the differential cross-section and total cross-section of <span>(J/Psi )</span> and <span>(rho ^0)</span> vector mesons, employing an analytical solution of the Balitsky-Kovchegov (BK) equation. Furthermore, we present the ratio of the longitudinal to the transverse cross-section for <span>(J/Psi )</span> and <span>(rho ^0)</span> as a function of <span>(Q^2)</span>. Two well-known vector meson wave function models, boosted Gaussian (BG) and Gaus-LC (GLC), have been integrated into our analysis, showing slight sensitivity to the chosen vector meson wave functions. Our theoretical predictions agree well with the available experimental data for vector meson production. The analytical solution of the BK equation proves reliable for the theoretical prediction of exclusive vector mesons within a specific range of <span>(Q^2)</span>.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Nonlinear Dynamics of Microtubules as Electrical Conduits in Cellular and Neuronal Functions: Soliton Solutions and Modulation Instability 微管作为细胞和神经元功能中的电通道的非线性动力学:孤子解和调制不稳定性
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-16 DOI: 10.1007/s13538-025-01773-2
Ifrah Iqbal, Hamood Ur Rehman, Muhammad Shoaib Saleem, Abdul Malik Sultan, Hameed Ashraf
{"title":"Nonlinear Dynamics of Microtubules as Electrical Conduits in Cellular and Neuronal Functions: Soliton Solutions and Modulation Instability","authors":"Ifrah Iqbal,&nbsp;Hamood Ur Rehman,&nbsp;Muhammad Shoaib Saleem,&nbsp;Abdul Malik Sultan,&nbsp;Hameed Ashraf","doi":"10.1007/s13538-025-01773-2","DOIUrl":"10.1007/s13538-025-01773-2","url":null,"abstract":"<div><p>Microtubules are fundamental to the cellular cytoskeleton, participating in diverse functions like cell division and intracellular transport facilitated by motor proteins such as dynein and kinesin. Moreover, they have critical roles in advanced neuronal activities, including consciousness and memory. This study explores the specific conditions that allow microtubules to operate as nonlinear electrical conduits for ion flow along their structures. By modeling them as nonlinear resistive, inductive, and capacitive (RLC) transmission lines, we employ the generalized Riccati equation mapping method to derive solutions for these dynamics. This study also gives a comprehensive literature review for the modeled equation and emphasizes the uniqueness of this interdisciplinary approach. Comparative analyses of specific outcomes are presented, with graphical illustrations to clarify the physical implications. Modulation instability (MI) analysis has been incorporated to investigate the frequency behavior of <span>( w(a) )</span> under varying parameters. By applying nonlinear engineering principles sheds new light on microtubule functionality in neuronal and cellular contexts, laying a foundation for new developments in bioengineering and nanobioscience.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effects of Multi-dimensional Defects on Optical and Thermoelectric Properties of Cerium-Doped ZnO Nanoparticles 多维缺陷对铈掺杂ZnO纳米粒子光学和热电性能的影响
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-15 DOI: 10.1007/s13538-025-01796-9
Danish Arif, Adeel Younas Abid, Tabinda Ishtiaq, Kashif Safeen, Gaber A. M. Mersal, Sufaid Shah, Adnan Ali, Atta Ullah Shah, Akif Safeen
{"title":"Effects of Multi-dimensional Defects on Optical and Thermoelectric Properties of Cerium-Doped ZnO Nanoparticles","authors":"Danish Arif,&nbsp;Adeel Younas Abid,&nbsp;Tabinda Ishtiaq,&nbsp;Kashif Safeen,&nbsp;Gaber A. M. Mersal,&nbsp;Sufaid Shah,&nbsp;Adnan Ali,&nbsp;Atta Ullah Shah,&nbsp;Akif Safeen","doi":"10.1007/s13538-025-01796-9","DOIUrl":"10.1007/s13538-025-01796-9","url":null,"abstract":"<div><p>The thermoelectric properties of materials are often limited by various factors, and enhancing these properties through defect engineering is an effective strategy. In this study, pure and cerium (Ce)–doped ZnO nanostructures were synthesized by a facile hydrothermal method with varying Ce concentrations. The thermoelectric enhancement in the context of point and bulk defects was experimentally demonstrated by establishing a correlation with structural and optical properties. X-ray diffraction analysis confirmed a hexagonal, highly crystalline structure. Scanning electron microscopy revealed that the particles took on a nanorod shape, elongating with increased doping. Photoluminescence spectra showed near-band-edge and green emissions for all samples, with the optical band gap decreasing as Ce doping increased. The absolute value of electrical conductivity and Seebeck coefficient depicted an increasing trend with the rise in Ce doping concentration. Our outcomes reveal that the addition of 1.2% of Ce into ZnO leads to improvements in the Seebeck coefficient to a maximum value of ~ 98 μV/K at 400 K, along with Figure-of-merit (ZT) improvement, which directly correlates with thermoelectric efficiency and oxygen vacancies along with secondary phase are thought to be the main reasons for that augmentation as supported by XRD and photoluminescence studies. Our study possibly possesses twofold advancements, first providing an opportunity to explore other rare earth–doped ZnO systems specifically for improved thermoelectric efficiency, second, it could be viable for better design of future thermoelectric materials via inspecting the role of defects.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Mathematical Analysis of the Transmission Dynamics of Hepatitis B Virus 乙型肝炎病毒传播动力学的数学分析
IF 1.5 4区 物理与天体物理
Brazilian Journal of Physics Pub Date : 2025-05-15 DOI: 10.1007/s13538-025-01772-3
Festus Abiodun Oguntolu, Olumuyiwa James Peter, Dipo Aldila, Ghaniyyat Bolanle Balogun, Oyinlola Patricia Ogunmola, Benjamin Idoko Omede
{"title":"Mathematical Analysis of the Transmission Dynamics of Hepatitis B Virus","authors":"Festus Abiodun Oguntolu,&nbsp;Olumuyiwa James Peter,&nbsp;Dipo Aldila,&nbsp;Ghaniyyat Bolanle Balogun,&nbsp;Oyinlola Patricia Ogunmola,&nbsp;Benjamin Idoko Omede","doi":"10.1007/s13538-025-01772-3","DOIUrl":"10.1007/s13538-025-01772-3","url":null,"abstract":"<div><p>Hepatitis B is a life-threatening hepatic illness induced by the Hepatitis B virus (HBV). This is a major worldwide health issue, especially in low- and middle-income nations in Africa and the Western Pacific, where prevalence rates are the greatest. Nevertheless, the existence of an efficacious vaccination, Hepatitis B persists in inflicting significant morbidity and death owing to a deficiency of awareness regarding the illness. Thus, we developed a deterministic mathematical model to elucidate the transmission dynamics of Hepatitis B, integrating elements such as vertical transmission, re-infection, and environmental viral concentration. The study starts with the calculation of the basic reproduction number and the assessment of the local stability of the disease-free equilibrium employing the Routh-Hurwitz criteria. A comprehensive examination of the model indicates that the model may experience backward bifurcation phenomena under some specific conditions. This trait presents considerable challenges in the proper management of Hepatitis B infection among the population. Assuming no re-infection of Hepatitis B post-recovery, the disease-free equilibrium point is globally asymptotically stable when the basic reproduction number is less than or equal to one. The sensitivity analysis of the basic reproduction number was conducted to assess the influence of each fundamental parameter in the model that contributes to disease transmission. Utilizing the optimal control theory to effectively curb the spread of Hepatitis B, we incorporated two time-varying control strategies, namely the prevention of susceptible individuals from acquiring HBV (through safe sex practice, regular washing of hands, and using protective hand gloves when handling blood, body fluid and semen) and the sensitization on individuals on personal hygiene, sterilization and proper disposal of medical and dental equipment like syringes in order to reduce the shedding of HBV in the environment. The numerical simulations indicated that Hepatitis B infection may be effectively managed and mitigated within the community if both control measures are correctly implemented.</p></div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"55 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信