Iranian Journal of Science and Technology, Transactions A: Science最新文献

{"title":"Positive Solution for Hadamard-Type Fractional Differential Equation with a Disturbance Parameter on Infinite Interval","authors":"Panzhen Liu,&nbsp;Zhaocai Hao","doi":"10.1007/s40995-026-01960-z","DOIUrl":"10.1007/s40995-026-01960-z","url":null,"abstract":"<div><p>This paper is concerned with Hadamard-type fractional boundary value problem involving a disturbance parameter on infinite interval. By applying the method of upper and lower solutions, Schauder fixed point theorem and fixed point index theory, we establish conditions for the existence, nonexistence, and multiplicity of positive solutions and show how the disturbance parameters influence the existence of positive solutions. Finally, an example is presented to illustrate our core results. Results of this paper extended and improved some existing results.</p></div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 4","pages":"1383 - 1394"},"PeriodicalIF":1.4,"publicationDate":"2026-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148434021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fractional Order Love Triangle System: An Analysis with Exponential Decay Memory","authors":"Rajarama Mohan Jena,&nbsp;Snehashish Chakraverty","doi":"10.1007/s40995-025-01941-8","DOIUrl":"10.1007/s40995-025-01941-8","url":null,"abstract":"<div><p>This paper introduces the competition component to Sprott's nonlinear love triangle model and observes that the new system likewise exhibits chaotic behaviour. In order to make the model more realistic, we have modified the existing fractional-order system using exponential decay memory. The occurrence of fractional systems proves the validity of this generalization with memory, since memory impacts romantic relationships over time. The considered model is assessed by using Caputo-Fabrizio fractional derivatives, and the fractional Adams-Bashforth numerical approach is used to solve the system based on Lagrange polynomial interpolation. Existence, uniqueness, and Ulam–Hyers stability are established through fixed-point theory and nonlinear analysis. Further, the error analysis of the current method has also been incorporated. Finally, numerical simulations are used to demonstrate the behaviour of the solution using graphical representations.</p></div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 4","pages":"1363 - 1382"},"PeriodicalIF":1.4,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum Transport in Germanene Under External Fields","authors":"Do Muoi","doi":"10.1007/s40995-025-01958-z","DOIUrl":"10.1007/s40995-025-01958-z","url":null,"abstract":"<div><p>We present a theoretical investigation of quantum transport in germanene, a topological insulator, under the influence of a perpendicular (z-direction) magnetic field and circularly polarized light. Using the Kubo formalism, we compute the Hall and longitudinal conductivities and demonstrate well-defined Landau quantization together with pronounced Shubnikov de Haas oscillations. The light polarization <span>( l = pm 1 )</span> induces opposite Floquet driven shifts in the Landau level spectrum of the two valleys, leading to asymmetric Hall plateaus and small phase shifts in the longitudinal conductivity at the single valley level. When both valleys are included, these opposite valley dependent shifts cancel, restoring the expected sequence of quantized Hall plateaus. The longitudinal conductivity exhibits nearly identical Shubnikov de Haas phase shifts for electrons and holes, indicating that the Floquet induced renormalization of the Dirac mass operates in an almost electron–hole symmetry manner. Our findings highlight the essential interplay between Floquet engineering, spin–orbit coupling, and valley degrees of freedom, and demonstrate that circularly polarized light can effectively tune magneto-transport characteristics in germanene without destroying their quantized structure.</p></div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 4","pages":"1605 - 1612"},"PeriodicalIF":1.4,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studying Bianchi Type-I Universes in the Modified f(R)-Gravity Scenario Using MCMC Approach","authors":"Shraddha Joshi,&nbsp;Shailendra D. Deo,&nbsp;Safiqul Islam,&nbsp;Aritra Sanyal,&nbsp;Praveen Kumar Dhankar","doi":"10.1007/s40995-026-01962-x","DOIUrl":"10.1007/s40995-026-01962-x","url":null,"abstract":"<div><p>In recent years, modified gravity theories, especially <i>f</i>(<i>R</i>) gravity, have attracted considerable interest. This work derives exact vacuum solutions for Bianchi type-I spacetimes in the framework of metric <i>f</i>(<i>R</i>) gravity. A key assumption is that the expansion scalar <span>(theta )</span> is proportional to the shear scalar <span>(sigma ^{2})</span>, leading to solutions of the form <span>(X=Y^{m})</span>, where <i>X</i> and <i>Y</i> denote metric coefficients. The Ricci scalar and associated physical quantities are analyzed for these models. It is found that the average Hubble parameter <i>H</i>(<i>T</i>) decreases with cosmic time, approaching equilibrium, consistent with standard cosmology. The expansion scalar <span>(theta (T))</span> attains very high values near <span>(Trightarrow 0)</span>, corresponding to the early inflationary or radiation-dominated epochs. The shear scalar <span>(sigma ^{2}(T))</span> diminishes with time, reflecting a trend toward isotropy, while the volume scale factor <i>V</i>(<i>T</i>) grows, signifying continuous expansion. Moreover, the function <i>f</i>(<i>R</i>) behaves regularly at low curvature (<span>(Rrightarrow 0)</span>) and reduces to <span>(f(R)rightarrow R)</span> in the high-curvature limit. To reinforce the theoretical investigation, we carry out a Markov Chain Monte Carlo (MCMC) analysis employing the latest Baryon Acoustic Oscillations (BAO), Cosmic Chronometer (CC), and Hubble parameter observations to restrict the model parameters. The resulting best-fit estimates demonstrate strong agreement among the different datasets, with the cosmological constant parameter <span>(psi )</span> exhibiting stability across all observational probes.</p></div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 4","pages":"1591 - 1604"},"PeriodicalIF":1.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of Self-heating Effect on the DC and RF Characteristics of a GaN HEMT","authors":"Prabir Kumar Shit,&nbsp;Radha Raman Pal,&nbsp;Sutanu Dutta","doi":"10.1007/s40995-025-01951-6","DOIUrl":"10.1007/s40995-025-01951-6","url":null,"abstract":"<div>\u0000 \u0000 <p>This manuscript represents a numerical-theoretical work to study the thermal and Self-Heating Effect (SHE) of a GaN High Electron Mobility Transistor (HEMT) for a wide range of drain fields. The temperature-dependent mathematical expressions of various DC and RF parameters of the device are developed considering SHE, particularly at a higher drain bias. Besides, the impact of gate leakage current for higher gate and drain field has been incorporated for a comprehensive analysis. It is noticed that the magnitude of the drain current and other parameters including output conductance, transconductance, cut-off frequency (CF) and maximum operating frequency (MOF) of the device degrade due to temperature and SHE. An effort has been given to optimize the device and design parameters such as thickness and doping of AlGaN layer to reduce the impact of SHE on the electrical characteristics of the device. In addition, a range of applied drain and gate biases are proposed to minimize the impact of SHE and to improve device performance.</p>\u0000 </div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 4","pages":"1581 - 1590"},"PeriodicalIF":1.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Breathe Easy: AI-Powered Air Quality Monitoring","authors":"R. Ezhilarasie,&nbsp;Nirmala Veeramani,&nbsp;Rajilal M. Vijayan","doi":"10.1007/s40995-025-01952-5","DOIUrl":"10.1007/s40995-025-01952-5","url":null,"abstract":"<div><p>This work proposes a framework for monitoring and predicting air quality using the Internet of Things (IoT) and Machine Learning features. It features a four-layer architecture based on IoT four-layer architecture encompassing sensing, network, processing, and application layers. The methodology involves collecting data, preprocessing it, creating a prediction model utilizing Long Short-Term Memory (LSTM) for air quality, acquiring real-time data through sensors, and incorporating an intuitive web application for real-time air quality monitoring. Information gathered from multiple sites across India concerning pollutants such as PM_2.5, PM₁₀, SO₂, CO, NO₂, NH₃, O₃ and NO was used as input to the LSTM model, enabling accurate predictions of air quality indices. The framework incorporates various sensors connected to the ESP32 microcontroller and the Raspberry Pi microcontroller acts as a gateway, employing the Message Queue Telemetry Protocol for data transmission towards the cloud. The assessment of model performance is performed using metrics such as Mean Absolute Error and Root Mean Square Error, highlighting the significance of achieving high prediction accuracy and robustness. A web interface was developed to improve user interaction, providing real-time air quality data, visual trend analyses, and risk predictions. The proposed system attained a prediction accuracy of 80.75%, underscoring its capability to enhance awareness of environmental health risks via continuous monitoring and data-informed insights.</p></div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 3","pages":"1063 - 1075"},"PeriodicalIF":1.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum-Informed DFT Study of SARS-CoV-2 Protein–Inhibitor Binding and Nanomaterial Interactions for Antiviral Design","authors":"Abhay P. Srivastava,&nbsp;Brijesh K. Pandey","doi":"10.1007/s40995-025-01956-1","DOIUrl":"10.1007/s40995-025-01956-1","url":null,"abstract":"<div>\u0000 \u0000 <p>We use Density Functional Theory (DFT) to study the electronic characteristics of SARS-CoV-2 inhibition. We also probe the role of critical viral elements (main protease (Mpro), spike receptor-binding domain (RBD), as well as potent antiviral agents (remdesivir, nirmatrelvir, and quercetin). The quantum-level behaviour of these interactions are evaluated using the frontier molecular orbital and the adsorption energy. Second, it investigates the binding performance and the activity of the nanomaterials (ZnO, graphene, TiO₂, MOF-5) on viral proteins. Here, strong interactions between MOF-5 and graphene are observed, primarily through π–π stacking and covalent bonding. We provide a rational basis for molecular and nanoscale inhibitors, as well as a pre-cognition and prognostic framework for screening future agents and designing new antiviral materials.</p>\u0000 </div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 3","pages":"1023 - 1031"},"PeriodicalIF":1.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rosmarinic Acid Alleviates Inflammation in Mast Cells Induced by RANKL by Inhibiting the PI3K/MAPK Signaling Pathway","authors":"Ho-Geun Kang,&nbsp;Hee-Yun Kim,&nbsp;Kyung-Min Jeong,&nbsp;Yu-Jin Choi,&nbsp;Hyun-Ja Jeong","doi":"10.1007/s40995-025-01957-0","DOIUrl":"10.1007/s40995-025-01957-0","url":null,"abstract":"<div>\u0000 \u0000 <p>Rosmarinic acid (RA) is a naturally occurring polyphenol found in various plant species, with diverse therapeutic applications. The receptor activator of nuclear factor kappa-B ligand (RANKL) plays a crucial role in inflammation, contributing to the production of inflammatory cytokines through the activation of phosphoinositide 3-kinases (PI3K)/protein kinase B (AKT) and mitogen-activated protein kinases (MAPKs) signaling pathways in mast cells. In this study, we investigated the potential of RA to suppress RANKL-induced inflammatory response signaling pathways in the human mast cell line, HMC-1 cells. The results demonstrated that RA effectively inhibits the activation of PI3K/AKT and MAPKs, including extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase in activated HMC-1 cells. The suppression of these pathways by RA led to reduced caspase-1 and nuclear factor-κB activation. Furthermore, RA decreased the secretion and mRNA expression of inflammatory cytokines, including interleukin (IL)-1β, IL-6, IL-8, and thymic stromal lymphopoietin, without affecting cytotoxicity. Our findings suggest that RA exerts a regulatory effect on RANKL-induced inflammatory reactions, potentially indicating its therapeutic role in treating RANKL-mediated inflammatory diseases.</p>\u0000 </div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 3","pages":"959 - 969"},"PeriodicalIF":1.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical Study of 76Br Production from Proton-Induced Reactions on Selenium Isotopes for PET Applications","authors":"Shatha Alafeshat,&nbsp;Halil Arslan,&nbsp;H. H. Saleh,&nbsp;Baris T. Tonguc","doi":"10.1007/s40995-026-01963-w","DOIUrl":"10.1007/s40995-026-01963-w","url":null,"abstract":"<div><p>Radionuclides have gained considerable attention in nuclear medicine owing to their broad applications in both therapeutic and diagnostic procedures. Among these, Bromine-76 (⁷⁶Br) is recognized as a reliable positron-emitting radionuclide widely used in Positron Emission Tomography (PET) imaging. The production of ⁷⁶Br can be achieved through several charged-particle reactions involving protons, deuterons, helium-3 and alpha particles. In this study, the proton-induced reactions ⁷⁶Se(p, n)⁷⁶Br, ⁷⁷Se(p, 2n)⁷⁶Br, ⁷⁸Se(p, 3n)⁷⁶Br, ⁷⁹Se(p, 4n)⁷⁶Br, and ⁸⁰Se(p, 5n)⁷⁶Br were investigated through theoretical modeling and Monte Carlo simulations. The excitation functions, proton ranges, theoretical yields, and End-of-Bombardment (EOB) activities were obtained using a combination of nuclear reaction codes and transport simulations. The calculated results were compared with experimental data and the TENDL-2023 nuclear data library, showing good overall agreement and confirming the reliability of the adopted computational approach for modeling ⁷⁶Br production.</p></div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 3","pages":"1249 - 1260"},"PeriodicalIF":1.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effects of Weathering Agents on the Physico-mechanical Properties of Gypsum Mortar","authors":"Amin Jamshidi,&nbsp;Luís Sousa,&nbsp;Mousa Sabzi,&nbsp;Kimiya Rashnouei","doi":"10.1007/s40995-025-01959-y","DOIUrl":"10.1007/s40995-025-01959-y","url":null,"abstract":"<div><p>Gypsum mortar is one of the most common building materials used in the Gachkeh Caravanserai (Lorestan Province, western Iran) and has experienced significant deterioration due to weathering agents. In the present work, a comprehensive laboratory study was conducted to investigate the effects of weathering agents on the physico-mechanical properties of gypsum mortar. To achieve this goal, some block samples of the mortar utilized in the ancient monument were collected. A number of specimens were prepared from block samples for various laboratory tests. The mineralogical composition of the mortar was studied through X-ray diffraction (XRD) analysis and microscopic thin sections. Accelerated weathering tests, including freezing-thawing (FT), wetting-drying (WD), and heating-cooling (HC) tests, were performed on the samples. The properties of the samples, including porosity, Brazilian tensile strength, and P-wave velocity, were measured before and during the various cycles of accelerated weathering tests. Moreover, the pore structure modification of the deteriorated samples was examined through scanning electron microscopy (SEM). The data analysis revealed that the samples experienced an increase in porosity and a decrease in the Brazilian tensile strength and P-wave velocity, indicating the adverse effects of the FT, WD, and HC processes on mortar deterioration. These results were in good agreement with the SEM images, indicating that the sample is vulnerable to FT, WD, and HC processes. However, data analysis revealed that FT had the greatest deterioration effect on the samples, followed by WD and HC. Moreover, the findings indicate that the deterioration of the samples caused by FT, WD, and HC was affected by their n and mineralogical composition. Identifying the FT as the most significant deterioration process of the samples can help in choosing the most appropriate conservation strategy to prevent progressive damage to the studied ancient monument. The results of the present study can be generalized to gypsum mortars used in ancient monuments in other regions of the world, which were exposed to weathering agents similar to those used in the present study (i.e., the FT, WD, and HC processes).</p></div>","PeriodicalId":600,"journal":{"name":"Iranian Journal of Science and Technology, Transactions A: Science","volume":"50 3","pages":"1077 - 1092"},"PeriodicalIF":1.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}