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{"title":"Circular motion and collisions of charged spinning test particles around magnetized Schwarzschild black hole","authors":"Tursinbay Oteev,&nbsp;Zdeněk Stuchlík,&nbsp;Javlon Rayimbaev,&nbsp;Inomjon Ibragimov,&nbsp;Murat Sharibaev,&nbsp;Ahmadjon Abdujabbarov","doi":"10.1140/epjc/s10052-025-14660-6","DOIUrl":"10.1140/epjc/s10052-025-14660-6","url":null,"abstract":"<div><p>The study of spinning charged particle dynamics around black holes in external fields offers insights into relativistic motion and the influence of spin-curvature and electromagnetic interactions. In this work, we investigate the motion of spinning charged test particles in the vicinity of Schwarzschild black holes immersed in asymptotically uniform magnetic fields. Using the Mathisson–Papapetrou–Dixon (MPD) equations, we derive the equations of motion and analyze the superluminal bound, which constrains the physically admissible values of the spin parameter. We investigate how this bound depends on the magnetic interaction parameter <span>(omega )</span>, which couples the particle’s charge to the external magnetic field. Furthermore, we explore the effective potential and examine how both spin and <span>(omega )</span> affect circular orbits and the dynamics of the particle. Our results reveal the nonlinear interplay between spin, curvature, and magnetic interaction, contributing to the broader understanding of charged spinning test particle motion in magnetized relativistic environments.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14660-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Investigation of the Effect of Secondary Oxidation on the Descaling Performance of AISI 5140 Low-Alloy Steel","authors":"Haoran Jiang,&nbsp;Xiaojiang Liu,&nbsp;Tao Jia,&nbsp;Haoyu Zhang,&nbsp;Zhang Wei,&nbsp;Yangqiang He,&nbsp;Borui Zhang,&nbsp;Limeng Cao","doi":"10.1007/s11085-025-10351-5","DOIUrl":"10.1007/s11085-025-10351-5","url":null,"abstract":"<div><p>The oxidation behavior of AISI 5140 low-alloy steel was investigated under air at oxidation temperatures ranging from 800 to 1100 °C and oxidation times ranging from 5 to 120 min. The microstructure and chemical composition of the oxide layer were characterized, and an oxidation kinetic model was constructed. The oxide layer exhibited a multi-layered structure, with the outer layer consisting primarily of Fe₂O₃, the intermediate layer of Fe₃O₄, and the inner layer comprising FeO and pre-eutectic Fe₃O₄. At the scale-substrate interface, a Si and Cr enriched layer was present. This study employed vertical rolling to descale the surface of oxidized samples; the effect of secondary oxidation on descaling performance was investigated. The results indicated that after the specimens were oxidized at 1200 °C in air, they were subjected to descaling and rolling processes, with a large amount of residual oxides remaining on their surfaces and poor flatness. When the specimens were oxidized at 1200 °C in air and descaled, followed by secondary oxidation at 1000 °C in air, and then subjected to descaling and rolling processes, their surfaces exhibited reduced residual oxides and improved flatness.</p></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"102 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graphene oxide-enhanced inverted MAPbI3 perovskite solar cells: improvements in efficiency and long-term stability","authors":"Ehsan H. Sabbar,&nbsp;Masoud Shabaninezhad,&nbsp;Hasnaa Imad Al-Shaikhli","doi":"10.1007/s10854-025-15676-0","DOIUrl":"10.1007/s10854-025-15676-0","url":null,"abstract":"<div><p>Perovskite Solar Cells (PSC) are a promising photovoltaic technology due to their high Power Conversion Efficiencies (PCE), tunable optoelectronic properties, and cost-effective fabrication. Despite rapid progress in their development, commercialization is hindered by environmental instability, including degradation under moisture, heat, and prolonged illumination. This study investigates the integration of Graphene Oxide (GO) as a defect passivation and moisture-resistant material to address these challenges in Methylammonium Lead Iodide (MAPbI₃)-based PSC. The treated devices achieved a peak PCE of 24 and an 8% improvement in Fill Factor (FF) compared to untreated devices, showcasing enhanced charge transport and reduced recombination losses. Stability tests under continuous illumination demonstrated that GO-treated devices retained over 50% of their initial PCE after 1000 h, while untreated devices exhibited near-complete degradation. Moreover, under 100% humidity conditions, treated devices maintained over 98% of their initial PCE, while untreated devices degraded below 95%. These findings highlight the dual functionality of GO as a defect passivator and environmental barrier, significantly improving both the operational efficiency and long-term durability of PSCs. The results provide a pathway for scalable and reliable PSC technologies that contribute to the advancement of next-generation photovoltaics.</p></div>","PeriodicalId":646,"journal":{"name":"Journal of Materials Science: Materials in Electronics","volume":"36 25","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variational principle for the time evolution operator, its usefulness in effective theories of condensed matter systems, and insight into the role played by the quantum geometry of unitary transformations","authors":"Michael Vogl","doi":"10.1140/epjp/s13360-025-06795-y","DOIUrl":"10.1140/epjp/s13360-025-06795-y","url":null,"abstract":"<div><p>We discuss a variational approach to determining the time evolution operator with the aim to improve on perturbation theory while preserving its simple structure. An immediate insight of our work is the appearance of a generalization of the quantum geometric tensor for unitary operators in the variational equations of motion. Quantum geometry, we then conclude, plays an important role in the evolution of variational parameters. We employ the method with the simplest ansatz (a power series in a time-independent Hamiltonian), which yields considerable improvements over a Taylor series. These improvements are because, unlike for a Taylor series of <span>(exp (-iHt))</span>, time <i>t</i> is not forced to appear at the same order as <i>H</i>, giving more flexibility for the description. We demonstrate that our results can also be employed to improve degenerate perturbation theory in a non-perturbative fashion. We concede that our approach described here is most useful for finite-dimensional Hamiltonians. As a first example of applications to perturbation theory, we present AB bilayer graphene, which we downfolded to a 2<span>(times)</span>2 model; our energy results considerably improve typical second-order degenerate perturbation theory. We then demonstrate that the approach can also be used to derive a non-perturbatively valid Heisenberg Hamiltonian. Here, the approach for a finite-size lattice yields excellent results. However, the corrections are not ideal for the thermodynamic limit (they depend on the number of sites <i>N</i>). Our approach adds almost no additional technical complications over typical perturbative expansions of unitary operators, making it ready for deployment in physics questions. One should expect considerably improved couplings for the degenerate perturbation theory of finite-size systems. We suggest a possible remedy to issues with the thermodynamic limit and demonstrate that that the approach in the limit of small perturbative parameter <i>t</i> agrees with typical results—even in the thermodynamic large <i>N</i> limit. Our work is an example of how the appearance of mathematically beautiful concepts like quantum geometry can indicate an opportunity to dig for improved approximations beyond typical perturbation theory.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Excess copper exposure and male reproductive toxicity: molecular mechanisms and potential interventions.","authors":"Zimo Zhou, Beiyao Wang, Huidan Deng, Yanqiu Zhu, Hongrui Guo","doi":"10.1007/s10534-025-00742-1","DOIUrl":"https://doi.org/10.1007/s10534-025-00742-1","url":null,"abstract":"<p><p>Copper (Cu) is an essential micronutrient in various enzymatic and physiological functions. However, excessive copper intake, mainly resulting from industrial emissions and improper agricultural practices, has raised growing concerns due to its toxicological effects, particularly on the male reproductive system. This review summarizes current research progress on copper-induced reproductive toxicity in males, emphasizing its impact on sperm quality, androgen production, and testicular structure and function. The underlying molecular mechanisms are discussed in detail, including oxidative stress, apoptosis, autophagy, ferroptosis, and cuproptosis. In addition, emerging therapeutic approaches, such as antioxidant treatments and copper chelators, are evaluated for their potential to mitigate these toxic effects. A comprehensive understanding of copper-induced male reproductive toxicity may offer new insights into the prevention and management of metal-related infertility.</p>","PeriodicalId":491,"journal":{"name":"Biometals","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145008058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"9-fluorenone-based synthetic sulfonamide compounds as dual inhibitors of SARS-CoV-2 Main-Protease and Papain-like Protease.","authors":"Sudesna Das, Prasad Sunnapu, Mohammed Rafi, Yasmin Begum, Sudip Dey, Akshay Joshi, Nittu Singh, Krishan Gopal Thakur, Parasuraman Jaisankar, Umesh Prasad Singh","doi":"10.1007/s11030-025-11315-2","DOIUrl":"https://doi.org/10.1007/s11030-025-11315-2","url":null,"abstract":"<p><p>Tilorone, a 9-fluorenone scaffold-based molecule, is a known broad-spectrum antiviral with an IC₅₀ of 180 nM against SARS-CoV-2, but its mechanism is not known. In the present study, we found it to have weak activity against PLpro (IC₅₀ = 30.7 ± 7.5 μM) and was inactive against Mpro. Several sulfonamide derivatives of 9-fluorenone, having the same scaffold as tilorone, were synthesized based on our in-silico studies to enhance their protease activity. They were evaluated for their inhibitory potential for targeting SARS-CoV-2 Mpro (main protease) and PLpro (papain-like protease) using FRET-based high-throughput screening and gel-based assays. Among the derivatives, 3e exhibited dual inhibition against Mpro (IC₅₀ = 23 ± 3.4 μM) and PLpro (IC₅₀ = 6.33 ± 0.5 μM), while 3h selectively inhibited PLpro (IC₅₀= 5.94 ± 1.0 μM). Both 3e and 3h suppressed SARS-CoV-2 replication with IC₅₀ values of 13.4 ± 0.28 μM and 18.2 ± 3.2 μM, respectively. Molecular docking and dynamics studies revealed that the NO₂ group in 3h enhances the rigidity of the BL2 loop of PLpro, contributing to its higher PLpro activity. Both 3e and 3h showed antiviral activity comparable with standard alpha-ketoamide inhibitor (13b-K) in cell-based assays and were non-cytotoxic with acceptable selectivity indices (S.I. > 5.5). These findings suggest that 9-fluorenone-based sulfonamides, particularly 3e and 3h, may be promising candidates as dual or selective protease inhibitors against SARS-CoV-2.</p>","PeriodicalId":708,"journal":{"name":"Molecular Diversity","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145008027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, magnetic, and electromagnetic wave absorption properties of AC/CB–Fe2O3 nanocomposites in the Ku-Band","authors":"Nurul Aisya Nadhirah Yusmadi,&nbsp;Rabaah Syahidah Azis,&nbsp;Ismayadi Ismail,&nbsp;Kamil Kayode Katibi,&nbsp;Bello Murtala Alhaji,&nbsp;Madiha Fathi Elmahaishi,&nbsp;Yusuf Sani,&nbsp;Chen Hongxu,&nbsp;Mohd Khairil Adzhar Mahmood","doi":"10.1007/s10854-025-15684-0","DOIUrl":"10.1007/s10854-025-15684-0","url":null,"abstract":"<div><p>The increasing demand for efficient microwave absorbers to curtail electromagnetic interference (EMI) and reduce radar cross-sections, indispensable for electronic shielding and stealth technologies, propels the pursuit of materials with excellent absorption, lightweight properties, and broadband performance. This study investigates the magnetic and Ku-band microwave performance of ferrite nanoparticles (α-Fe₂O₃) blended with carbon-based materials, Activated Carbon (AC), and Carbon Black (CB), synthesized via high-energy ball milling (HEBM) and heat treatment. Fe₂O₃ nanoparticles were milled for 5, 7, and 9 h to evaluate the milling time on structural and magnetic properties. Blended Fe₂O₃/AC and Fe₂O₃/CB composites were subjected to 1-h heat treatment at 200 °C. X-ray diffraction (XRD) analysis confirmed phase formation and crystallinity, while Vibrating Sample Magnetometer (VSM) characterization evaluated magnetic properties. Increasing milling time reduced crystallite size and coercivity (H_c), enhancing soft magnetic behaviour. The result obtained shows that the sample milled for 9 h exhibited higher saturation (M_s) and remanent magnetization (M_r). The blended Fe₂O₃/AC composite, prepared using 9-h milled Fe₂O₃ and 20% AC, achieved a remarkable reflection loss (R_L) of -39.10 dB at 16.95 GHz (Ku-band) for a 2.0 mm thick sample, demonstrating almost complete microwave absorption (99.99%). These findings advance the production of high-performance and lightweight absorbers by linking crystallite refinement, carbon allotrope selection, and electromagnetic response.</p></div>","PeriodicalId":646,"journal":{"name":"Journal of Materials Science: Materials in Electronics","volume":"36 25","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10854-025-15684-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geometrical distribution of agents based on a generalised Potts model","authors":"Alejandro Rivero,&nbsp;Alfonso Tarancón,&nbsp;Carlos Tarancón","doi":"10.1140/epjb/s10051-025-01005-1","DOIUrl":"10.1140/epjb/s10051-025-01005-1","url":null,"abstract":"<p>In collective local interaction systems with agents assigned to different profiles (categories, traits), the distribution of such profiles in the neighbourhood of any agent affects the exchange of ideas, a basic element in Collective Intelligence experiments. It is important to control this distribution experimentally, asking for criteria that should range from maximum homogeneity to maximum difference. We suggest a method where we obtain these criteria by adding an extra interaction term to the Q-state Potts model, producing a rich vacuum structure. By controlling the two parameters of the model, we can obtain different patterns for the geometrical distribution of the agents. We study the transitions and phase diagram of this model, considering the physics at constant magnetization, and show that the states correspond to a large diversity of mixing patterns, directly applicable to agent distribution in CI experiments.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 9","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-025-01005-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005572","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}

{"title":"Eco-sustainably synthesized magnesium oxide-based flexible and stable self-powered piezoelectric wearable sensor","authors":"Vundrala Sumedha Reddy,&nbsp;Seeram Ramakrishna","doi":"10.1007/s10854-025-15671-5","DOIUrl":"10.1007/s10854-025-15671-5","url":null,"abstract":"<div><p>Piezoelectric sensors provide an advantage over other transduction methods for the dynamic detection of mechanical stimuli due to its simple device structure and active mechanism of electric charge generation. High sensor sensitivity is essential for precisely detecting minute changes in real-time motion. On the environmentally friendly sustainable note, utilizing bio waste is necessary in the present scenario. Keeping these aspects in check, here a nanofiber piezoelectric sensor made of polyvinylidene fluoride (PVDF) and biosynthesized magnesium oxide (MgO) composite has been developed with the objective of creating a flexible, stable, and self-powered extremely sensitive sensor. We used dried leaves that had been collected from plants and trees (mainly from Leguminosae family) to produce MgO nanoparticles in a sustainable manner. The optimal PVDF and nanofiller composition for detecting several force categories (torsion, shear, tensile, compression) with high reliability has been demonstrated by methodical optimization of MgO concentration and rigorous analytical investigations (vital signal monitoring, posture corrector, expression reader). The device showcased the sensitivity of 1.204 V/N in the force range of 0.0001–78.4 N with 66.8 as performance, while preserving stability in the wide working range of metric units through real-time applications.</p></div>","PeriodicalId":646,"journal":{"name":"Journal of Materials Science: Materials in Electronics","volume":"36 25","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NaZr₂P₃O₁₂ as a NASICON-type solid-state electrolyte: insights into synthesis, structure, and ionic conduction","authors":"S. Nasri,&nbsp;A. Oueslati","doi":"10.1007/s10854-025-15693-z","DOIUrl":"10.1007/s10854-025-15693-z","url":null,"abstract":"<div><p>NaZr₂P₃O₁₂ (NZP), a NASICON-type solid-state electrolyte, is investigated as a promising material for sodium-ion batteries. Synthesized via a scalable solid-state reaction, NZP exhibits a phase-pure, highly crystalline trigonal structure, confirmed by X-ray diffraction (lattice parameters: a = b = 8.793 Å, c = 22.716 Å). Electrochemical impedance spectroscopy reveals a robust ionic conductivity of 1.17 × 10⁻⁶ Ω⁻¹ cm⁻¹ at 673 K and a low activation energy of 0.32 eV, enabling efficient Na⁺ transport. This study uncovers a novel temperature-dependent shift in conduction mechanisms, from small-polaron tunneling below 520 K to correlated barrier hopping above 520 K, providing fresh insights into NZP’s ionic dynamics. Uniform morphology (via SEM) and complex relaxation dynamics (non-Debye behavior) further elucidate charge transport pathways dominated by grain effects. NZP’s thermal stability and cost-effective synthesis position it as a strong candidate for grid-scale sodium-ion batteries. These findings offer a clear framework for designing high-performance solid electrolytes, advancing sustainable energy storage.</p></div>","PeriodicalId":646,"journal":{"name":"Journal of Materials Science: Materials in Electronics","volume":"36 25","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}