bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultraflat Cu(111) foils by surface acoustic wave-assisted annealing
Authors: Tian Bo , Li Junzhu , Wang Qingxiao , Samad Abdus , Yuan Yue , Hedhili Mohamed Nejib , Jangir Arun , Gruenewald Marco , Lanza Mario , Schwingenschlögl Udo , Fritz Torsten , Zhang Xixiang , Liu Zheng
Published: November 2024

Ultraflat metal foils are essential for semiconductor nanoelectronics applications and nanomaterial epitaxial growth. Numerous efforts have been devoted to metal surface engineering studies in the past decades. However, various challenges persist, including size limitations, polishing non-uniformities, and undesired contaminants. Thus, further exploration of advanced metal surface treatment techniques is essential. Here, we report a physical strategy that utilizes surface acoustic wave assisted annealing to flatten metal foils by eliminating the surface steps, eventually transforming commercial rough metal foils into ultraflat substrates. Large-area, high-quality, smooth 2D materials, including graphene and hexagonal boron nitride (hBN), were successfully grown on the resulting flat metal substrates. Further investigation into the oxidation of 2D-material-coated metal foils, both rough and flat, revealed that the hBN-coated flat metal foil exhibits enhanced anti-corrosion properties. Molecular dynamics simulations and density functional theory validate our experimental observations.
Single-molecule imaging and molecular dynamics simulations reveal early activation of the MET receptor in cells
Authors: Li Yunqing , Arghittu Serena M. , Dietz Marina S. , Hella Gabriel J. , Haße Daniel , Ferraris Davide M. , Freund Petra , Barth Hans-Dieter , Iamele Luisa , de Jonge Hugo , Niemann Hartmut H. , Covino Roberto , Heilemann Mike
Published: November 2024

Embedding of cell-surface receptors into a membrane defines their dynamics but also complicates experimental characterization of their signaling complexes. The hepatocyte growth factor receptor MET is a receptor tyrosine kinase involved in cellular processes such as proliferation, migration, and survival. It is also targeted by the pathogen Listeria monocytogenes, whose invasion protein, internalin B (InlB), binds to MET, forming a signaling dimer that triggers pathogen internalization. Here we use an integrative structural biology approach, combining molecular dynamics simulations and single-molecule Förster resonance energy transfer (smFRET) in cells, to investigate the early stages of MET activation. Our simulations show that InlB binding stabilizes MET in a conformation that promotes dimer formation. smFRET reveals that the in situ dimer structure closely resembles one of two previously published crystal structures, though with key differences. This study refines our understanding of MET activation and provides a methodological framework for studying other plasma membrane receptors.
Subthalamic stimulation causally modulates human voluntary decision-making to stay or go
Authors: Wang Yichen , Wang Linbin , Manssuer Luis , Zhao Yi-jie , Ding Qiong , Pan Yixin , Huang Peng , Li Dianyou , Voon Valerie
Published: November 2024

The voluntary nature of decision-making is fundamental to human behavior. The subthalamic nucleus is important in reactive decision-making, but its role in voluntary decision-making remains unclear. We recorded from deep brain stimulation subthalamic electrodes time-locked with acute stimulation using a Go/Nogo task to assess voluntary action and inaction. Beta oscillations during voluntary decision-making were temporally dissociated from motor function. Parkinson’s patients showed an inaction bias with high beta and intermediate physiological states. Stimulation reversed the inaction bias highlighting its causal nature, and shifting physiology closer to reactive choices. Depression was associated with higher alpha during Voluntary-Nogo characterized by inaction or inertial status quo maintenance whereas apathy had higher beta-gamma during voluntary action or impaired effortful initiation of action. Our findings suggest the human subthalamic nucleus causally contributes to voluntary decision-making, possibly through threshold gating or toggling mechanisms, with stimulation shifting towards voluntary action and suggest biomarkers as potential clinical predictors.
Stability and bifurcation analysis of a 2DOF dynamical system with piezoelectric device and feedback control
Authors: Bahnasy Taher A. , Amer T. S. , Abohamer M. K. , Abosheiaha H. F. , Elameer A. S. , Almahalawy A.
Published: November 2024

This study aims to demonstrate the behaviors of a two degree-of-freedom (DOF) dynamical system consisting of attached mass to a nonlinear damped harmonic spring pendulum with a piezoelectric device. Such a system is influenced by a parametric excitation force on the direction of the spring’s elongation and an operating moment at the supported point. A negative-velocity-feedback (NVF) controller is inserted into the main system to reduce the undesired vibrations that affect the system’s efficiency, especially at the resonance state. The equations of motion (EOM) are derived by using Lagrangian equations. Through the use of the multiple-scales-strategy (MSS), approximate solutions (AS) are investigated up to the third order. The accuracy of the AS is verified by comparing them to the obtained numerical solutions (NS) through the fourth-order Runge-Kutta Method (RK-4). The study delves into resonance cases and solvability conditions to provide the modulation equations (ME). Graphical representations showing the time histories of the obtained solutions and frequency responses are presented utilizing Wolfram Mathematica 13.2 in addition to MATLAB software. Additionally, discusses the bifurcation diagrams, Poincaré maps, and Lyapunov exponent spectrums to show the various behavior patterns of the system. To convert vibrating motion into electrical power, a piezoelectric sensor is connected to the dynamical model, which is just one of the energy harvesting (EH) technologies with extensive applications in the commercial, industrial, aerospace, automotive, and medical industries. Moreover, the time histories of the obtained solutions with and without control are analyzed graphically. Finally, resonance curves are used to discuss stability analysis and steady-state solutions.
Enhanced antimicrobial efficacy of hydroxyapatite-based composites for healthcare applications
Authors: Hassanain Maher , Abdel-Ghafar Hamdy Maamoun , Hamouda Hamed I. , El-Hosiny Fouad I. , Ewais Emad M. M.
Published: November 2024

Hydroxyapatite (HAp) and hydroxyapatite-based materials show promising potential in the healthcare sector due to their distinctive properties such as biocompatibility, antimicrobial efficacy, non-toxicity, and robust mechanical characteristics. This makes HAp materials play an important role in hindering infection spreading in healthcare provider institutions. This study assesses the antimicrobial efficacy of the developed hydroxyapatite-based composites incorporating copper, zinc, and silver nanoparticles. The synthesized HAp and its modified composite variants (Cu/HAp, Zn/HAp, and Ag/HAp) with varying ratios ranging from 0 to 15% (wt) were characterized using XRD, XPS, SEM, and TEM analyses. Furthermore, the antibacterial and antifungal properties of the synthesized HAp and HAp-based composites were evaluated. The antibacterial effectiveness of the HAp and its composites was evaluated using a modified disc diffusion test, where the resulting inhibition zones on the agar surface were observed. All the HAp and HAp-based composites (HAp, Cu/HAp, Zn/HAp, and Ag/HAp materials) elicited in the formation of inhibitory zones. The most substantial inhibition values were observed for the 5% Ag/HAp formulation, with values of 19.7 and 13.8, against E. coli and S. aureus, respectively. The 5% Ag/HAp concentration may strike an ideal balance, providing high antimicrobial activity without adverse effects on biocompatibility or material stability. These findings underscore the recommendation of the proposed HAp-based composites for infection control measures through their application on medical instruments, textiles, healthcare personnel attire, and patient garments.
An analysis of the textural properties of activated carbons obtained from biomass via the LBET, NLDFT and QSDFT methods
Authors: Kwiatkowski Mirosław
Published: November 2024

This article presents the unique research results of the comprehensive analysis of the porous structure of activated carbons obtained from biomass waste materials from the wood industry during activation in an air atmosphere. The porous structure was analysed on the basis of nitrogen and argon adsorption isotherms via complementary multi-method analysis, i.e. the new numerical clustering-based adsorption analysis, the non-local density functional theory and the quenched solid density functional theory methods. The analytical results for the prepared activated carbons were compared with analogous results obtained for commercial activated carbon. On the basis of the conducted studies it has been determined that the new numerical clustering-based adsorption analysis method gives credible and valuable information on the textural properties of activated carbons which are in strict correlation and mutually complement with the results of the analysis with the use of the quenched solid density functional theory method. The research results obtained in this paper, it has also been shown that from waste materials of the wood industry, in a relatively cheap and cleaner production process, it is possible not only to obtain carbonaceous materials almost comparable to commercial activated carbon, but also to manage the waste in accordance with the principles of a closed-loop economy and sustainable development. The paper pays also attention to the often overlooked economic and ecological aspects, which should nevertheless be taken into account when comparing different adsorbents, rather than their textural properties alone.
Examining prestructured β-actin peptides as substrates of histidine methyltransferase SETD3
Authors: Maas Marijn N. , Bilgin Nurgül , Moesgaard Laust , Hintzen Jordi C. J. , Drozak Anna , Drozak Jakub , Kongsted Jacob , Mecinović Jasmin
Published: November 2024

The Nτ-His73 methylation of β-actin by histidine methyltransferase SETD3 is required for the integrity of the cellular cytoskeleton. Modulation of SETD3 activity in human cells facilitates cancer-like changes to the cell phenotype. SETD3 binds β-actin in an extended conformation, with a conserved bend-like motif surrounding His73. Here, we report on the catalytic specificity of SETD3 towards i, i + 3 stapled β-actin peptides possessing a limited conformational freedom surrounding the His73 substrate residue via positions Glu72 and Ile75. Stapled β-actin peptides were observed to be methylated less efficiently than the linear β-actin peptide. None of the stapled β-actin peptides efficiently inhibited the SETD3-catalyzed Nτ-His73 methylation reaction. Molecular dynamics simulations demonstrated that the unbound and SETD3-bound β-actin peptides display different backbone flexibility and bend-like conformations, highlighting their important role in substrate binding and catalysis. Overall, these findings suggest that reduced backbone flexibility of β-actin prevents the formation of optimal protein-peptide interactions between the enzyme and substrate, highlighting that the backbone flexibility needs to be considered when designing β-actin-based probes and inhibitors of biomedically important SETD3.
Development of a method for estimating asari clam distribution by combining three-dimensional acoustic coring system and deep neural network
Authors: Kadoi Tokimu , Mizuno Katsunori , Ishida Shoichi , Onozato Shogo , Washiyama Hirofumi , Uehara Yohei , Saito Yoshimoto , Okamoto Kazutoshi , Sakamoto Shingo , Sugimoto Yusuke , Terayama Kei
Published: November 2024

Developing non-contact, non-destructive monitoring methods for marine life is crucial for sustainable resource management. Recent monitoring technologies and machine learning analysis advancements have enhanced underwater image and acoustic data acquisition. Systems to obtain 3D acoustic data from beneath the seafloor are being developed; however, manual analysis of large 3D datasets is challenging. Therefore, an automatic method for analyzing benthic resource distribution is needed. This study developed a system to estimate benthic resource distribution non-destructively by combining high-precision habitat data acquisition using high-frequency ultrasonic waves and prediction models based on a 3D convolutional neural network (3D-CNN). The system estimated the distribution of asari clams (Ruditapes philippinarum) in Lake Hamana, Japan. Clam presence and count were successfully estimated in a voxel with an ROC-AUC of 0.9 and a macro-average ROC-AUC of 0.8, respectively. This system visualized clam distribution and estimated numbers, demonstrating its effectiveness for quantifying marine resources beneath the seafloor.
Driver mutations associated with signatures of platinum sensitivity in germ cell tumors
Authors: Sawa Yun Cheng , Jia Liwei , Krause Harris , Meagher Margaret , Millard Frederick , Elliott Andrew , Lafin John T. , Jamieson Christina , Antonarakis Emmanuel S. , D’Souza Anishka , Giannikou Krinio , Amatruda James F. , Daneshmand Siamak , McKay Rana R. , Oberley Matthew , Nabhan Chadi , Bagrodia Aditya
Published: November 2024

We sought to evaluate the genomic and transcriptomic landscapes in primary and metastatic germ cell tumors (GCTs; N = 138) to uncover factors that drive cisplatin resistance. Prevalence was calculated for platinum-resistant alterations (PRAs; KRAS, TP53, and KIT mutations, and MDM2 amplification) and high copy number amplifications (CNA ≥ 6 copies). Tumors were designated as chemo-naïve (PreC, N = 66) or post-chemotherapy (PostC, N = 17). A transcriptomic signature associated with platinum sensitivity (PSS, high suggests increased sensitivity) was applied. KIT mutations were observed in 14.5% of primary versus 1.8% of met and 0% of lymph. TP53 mutations were identified in 10% of primary GCTs versus 17% of met and 16.7% of lymph. MDM2 CNAs were similar between sites. PRA-positive PreC GCTs had significantly lower average PSS scores compared to PRA-negative tumors. Lower PSS scores in chemo-naïve tumors were associated with PRAs, suggesting a potential mechanism for platinum resistance.
Reduced penetrance BRCA1 and BRCA2 pathogenic variants in clinical germline genetic testing
Authors: Pal Tuya , Mundt Erin , Richardson Marcy E. , Chao Elizabeth , Pesaran Tina , Slavin Thomas P. , Couch Fergus J. , Monteiro Alvaro N. A.
Published: November 2024

Prior studies have suggested the existence of reduced penetrance pathogenic variants (RPPVs) in BRCA1 and BRCA2 (BRCA) which pose challenges for patient counseling and care. Here, we sought to establish RPPVs as a new category of variants. Candidate BRCA RPPVs provided by two large clinical diagnostic laboratories were compiled to identify those with the highest likelihood of being a RPPV, based on concordant interpretations. Sixteen concordant candidate BRCA RPPVs across both laboratories were systematically assessed. RPPVs included missense, splice site, and frameshift variants. Our study establishes RPPVs as a new class of variants imparting a moderately increased risk of breast cancer, which impacts risk-informed cancer prevention strategies, and provides a framework to standardize interpretation and reporting of BRCA RPPVs. Further work to define clinically meaningful risk thresholds and categories for reporting BRCA RPPVs is needed to personalize cancer risks in conjunction with other risk factors.
Predicting deterioration in dengue using a low cost wearable for continuous clinical monitoring
Authors: Ming Damien Keng , Daniels John , Chanh Ho Quang , Karolcik Stefan , Hernandez Bernard , Manginas Vasileios , Nguyen Van Hao , Nguyen Quang Huy , Phan Tu Qui , Luong Thi Hue Tai , Trieu Huynh Trung , Holmes Alison Helen , Phan Vinh Tho , Georgiou Pantelis , Yacoub Sophie ,   On behalf of the VITAL consortium
Published: November 2024

Close vital signs monitoring is crucial for the clinical management of patients with dengue. We investigated performance of a non-invasive wearable utilising photoplethysmography (PPG), to provide real-time risk prediction in hospitalised individuals. We performed a prospective observational clinical study in Vietnam between January 2020 and October 2022: 153 patients were included in analyses, providing 1353 h of PPG data. Using a multi-modal transformer approach, 10-min PPG waveform segments and basic clinical data (age, sex, clinical features on admission) were used as features to continuously forecast clinical state 2 h ahead. Prediction of low-risk states (17,939/80,843; 22.1%), defined by NEWS2 and mSOFA < 6, was associated with an area under the precision-recall curve of 0.67 and an area under the receiver operator curve of 0.83. Implementation of such interventions could provide cost-effective triage and clinical care in dengue, offering opportunities for safe ambulatory patient management.
Greening urban areas in line with population density and ecological zone can reduce premature mortality
Authors: Garber Michael D. , Benmarhnia Tarik , Zhou Weiqi , Mudu Pierpaolo , Rojas-Rueda David
Published: November 2024

Urban green space and urban compactness are each important principles for designing healthy, climate-resilient cities. The principles can co-exist, but greening may come at density’s expense if not considered deliberately. Existing studies estimating health impacts of greening scenarios have not considered what level of greenness is attainable for different population densities. Here, using the square kilometer as the unit of analysis, we estimate non-accidental mortality that could be prevented among adults older than 30 by greening that small area to a level of greenness assumed to be attainable based on its broader urban area (N = 15,917 globally), population density, and ecological zone. Results suggest a large potential for urban greening even in the most population-dense parts of cities such that on average 54 deaths per 100,000 could be prevented per year in those areas. That estimate may be about 25% higher or lower due to uncertainty in the underlying model.
Higher temperatures exacerbate effects of antibiotics on methanogenesis in freshwater sediment
Authors: Bollinger E. , Schwilden P. , Lai F. Y. , Schulz R. , Bundschuh M. , Filker S.
Published: November 2024

Methane (CH4) emissions from natural systems are rising in a concerning manner with an incomplete understanding of its drivers. Recently, chemical stressors such as antibiotics have been suggested as a thus far overlooked factor increasing methanogenesis in freshwaters. Since usage and toxicological impact of antibiotics could increase in a warming climate, we assessed the temperature-dependence of antibiotic effects on methanogenesis. In this light, we conducted anaerobic incubations with freshwater sediment at 10, 15, and 20 °C in presence of a mixture of five antibiotics at field-relevant concentrations. Weekly measurements of CH4 showed a strong temperature dependence of antibiotic effects by changing effect sizes, directions and dynamics. While antibiotics reduced CH4 production at 10 °C, methanogenesis was elevated at 15 °C with the most pronounced increase occurring at 20 °C. Furthermore, antibiotics changed the prokaryotic assemblage at all temperatures and effect patterns of CH4 producing Methanomicrobia strongly followed the patterns observed for methanogenesis. While analyses of compound-specific stable isotopes and the metatranscriptome suggest the acetoclastic pathway as most relevant, linking prokaryotic structure to function remains one of the most significant research challenges. Nevertheless, the evidence provided by this study suggests a positive relationship between temperature and the stimulating effects of antibiotics on CH4 production.
Access to radiotherapy in improving gastric cancer care quality and equality
Authors: Wang Minmin , Huang Kepei , Fan Xiaohan , Wang Jia , Jin Yinzi , Zheng Zhi-Jie
Published: November 2024

Background

Quality health services could improve patient outcomes and prognosis. Gastric cancer care was of great disparity across genders. Disparities within radiotherapy units could impact gastric cancer care, potentially exacerbating gender-based inequalities.

Methods

We retrieved the disease burden data from Global Burden of Disease 2019. A quality of care index was constructed by applying principal component analysis techniques. The disparity of gastric cancer care across genders was described, and the association of access to radiotherapy with gastric cancer care as well as gender disparity was explored.

Results

Males receive better quality of gastric cancer care than females, and this gender disparity is widening in middle-low socio-development regions. A positive correlation emerges between the density of radiotherapy facilities and an elevated quality of care, and reduced gender-based disparities.

Conclusions

The association between robust radiotherapy access, improved gastric cancer QCI, and reduced gender-based disparities spotlights the imperative of fortifying radiotherapy infrastructure within areas and populations in greatest need.
A behaviour change strategy to reduce greenhouse gas emissions from international scientific conferences and meetings
Authors: Richards David A. , Bellon Filip , Goñi-Fuste Blanca , Grech Joseph , Hollowood Lorna , Mezzalira Elisabetta , Möhler Ralph , Perez de Gracia David , Seckin Muzeyyen , Velonaki Venetia S. , Teixeira-Santos Luísa M. , Deschodt Mieke
Published: November 2024

We estimated the environmental impact and financial cost of two exemplar in-person academic events organised by the European academic society, the European Academy of Nursing Science, identified the main sources of these emissions, and then mapped them against the COM-B behaviour change framework of capability, opportunity, motivation to identify strategies that could be applied by organisers and participants to reduce this impact. These events contributed 41 tonnes and 99 tonnes of CO2e emissions per event, a per-participant mean of either 0.324 (SD 0.173) or 0.724, (SD 0.263) tonnes, representing 2 to 5.5 times the daily per-person European average. Distance from home was the largest contributor to emissions. Costs were similar for both events. Our multi-component behavioural change programme includes environmental change, enablement, education, incentivisation and persuasion, by which organisers provide participants with the opportunity for less-polluting behaviour, and enhance participants capabilities and motivation to act on the opportunities provided.
Development of a Ru–porphyrin-based supramolecular framework catalyst for styrene epoxidation
Authors: Yoneda Akira , Watanabe Taito , Kosugi Kento , Takahara Teppei , Kusaka Shinpei , Matsuda Ryotaro , Saga Yutaka , Kambe Tetsuya , Kondo Mio , Masaoka Shigeyuki
Published: November 2024

A new microporous supramolecular-framework catalyst containing Ru(ii)–porphyrin and pyrenylphenyl moieties is synthesised and structurally characterised. The framework catalyst efficiently promotes the epoxidation reactions of styrene derivatives.
Thermoelectric behavior of (Ba0.2Sr0.2Ca0.2La0.2Na0.2)CoO3 high entropy cobaltate-based perovskite
Authors: Bhattacharya Tathagata , Banerjee Ritwik , Maiti Tanmoy
Published: November 2024

Novel high entropy cobaltate based perovskite has been synthesized for the first time. It exhibits ultralow thermal conductivity caused by multi-phonon scattering, which can be used for high temperature thermoelectric applications.
Applying standard addition to determine antimony isotopes in low-Sb samples using HG-MC-ICP-MS
Authors: Zhu Honggang , Zhu Jian-Ming , Tan Decan , Lu Zhuo , Liao Hongfei , Ma Yiwei
Published: November 2024

The δ123Sb value of BCR-2 obtained by the standard addition (SA) method.
DORA-XGB: an improved enzymatic reaction feasibility classifier trained using a novel synthetic data approach
Authors: Chainani Yash , Ni Zhuofu , Shebek Kevin M. , Broadbelt Linda J. , Tyo Keith E. J.
Published: November 2024

We outline a method for synthetically generating negative data by considering alternative reaction centers on small-molecule substrates that are known to participate in enzymatic reactions.
Universal skyrmion logic gates and circuits based on antiferromagnetically coupled skyrmions without a topological Hall effect
Authors: Yagan Rawana , Cheghabouri Arash Mousavi , Onbasli Mehmet C.
Published: November 2024

Nanoscale skyrmions are spin-based quasiparticles that are promising for nonvolatile logic applications.
Long afterglow epoxidized soybean oil polymer composites with reversible dynamic cross-linking for intelligent coating
Authors: Hu Jiaman , Wang Zihao , Yang Minglin , Yu Chuansong , Li Siyu , Miao Yinggang , Quan Xiangqian , Liu Jize , Shao Shiyang
Published: November 2024

The intelligent coating possesses a crack monitoring function in real time, with desirable shear strength and self-healing, and exhibits rapid degradation ability.
Percolation transitions in a binary mixture of active Brownian particles with different softness
Authors: Sanoria Monika , Chelakkot Raghunath , Nandi Amitabha
Published: November 2024

Homogeneous active Brownian particle (ABP) systems with purely repulsive interactions are considered to exhibit a simple phase behavior, but various physical attributes of active entities can lead to variation in the collective dynamics.
Phase coded waveforms for integrated sensing and communication systems
Authors: Şahin Sevda , Girici Tolga
Published: November 2024

Nowadays, especially with the developments in the automotive industry, it has become a highly popular topic for radar and communication systems to operate on the same platform and perform joint tasks to increase situational awareness. Sharing the hardware of the radar and communication systems and using a joint waveform for both functions eliminate interference problems between the systems, increasing the effectiveness of the joint task. In studies where radar signals are utilised for communication functions, continuous wave frequency modulation or intra‐pulse frequency modulation is generally employed to transmit communication signals. There are a few studies in the literature on joint radar and communication waveforms using phase modulation. In these studies, phase modulation is not employed directly for both functions. As a contribution to the literature, this study evaluates the usage of joint radar and communications waveforms, such as Barker sequences and Zadoff–Chu sequences as opposed to linear frequency modulation. We compare these waveforms terms of range‐speed detection and symbol error rate.
From challenges to opportunities: navigating the human response to automated agents in the workplace
Authors: Ðula Ivan , Berberena Tabea , Keplinger Ksenia , Wirzberger Maria
Published: November 2024

Workers are increasingly embracing Artificial Intelligence (AI) to optimise various aspects of their operations in the workplace. While AI offers new opportunities, it also presents unintended challenges that they must carefully navigate. This paper aims to develop a deeper understanding of workers’ experiences with interactions with automated agents (AA) in the workplace and provide actionable recommendations for organisational leaders to achieve positive outcomes. We propose and test a simulation model that quantifies and predicts workers’ experiences with AA, shedding light on the interplay of diverse variables, such as workload, effort and trust. Our findings suggest that lower-efficiency AA might outperform higher-efficiency ones due to the constraining influence of trust on adoption rates. Additionally, we find that lower initial trust in AA could lead to increased usage in certain scenarios and that stronger emotional and social responses to the use of AA may foster greater trust but result in decreased AA utilisation. This interdisciplinary research blends a systems dynamics approach with management theories and psychological concepts, aiming to bridge existing gaps and foster the sustainable and effective implementation of AA in the workplace. Ultimately, our research endeavour contributes to advancing the field of human-AI interaction in the workplace.
Thermal and structural analysis of binary mixtures of pyrimidine liquid crystals using modulated differential calorimetry and synchrotron x-ray diffraction measurements
Authors: Mitra Smriti , Prasad Akhileshwar , Das Malay Kumar , Das Banani , Upadhyay Anuj , Sagdeo Archana , Yogi Arvind Kumar
Published: November 2024

We present a systematic experimental dataset on the temperature dependence of specific heat capacity in a binary mixture of the second and seventh homologous series of 5-alkyloxy-2-(4-nonyloxy-phenyl) pyrimidine (PhP) liquid crystal compound. These binary mixtures exhibit nematic, smectic-A, and smectic-C phases within a concentration range of x
PhP1 = 0–0.45. The liquid crystalline phases are structurally characterized using synchrotron x-ray diffraction. We determine the apparent molecular length in the nematic phase, smectic layer spacing, average distance between the long axes of molecules, correlation length, and orientational order parameters (<P
2> and <P
4>) as functions of temperature. The tilt angle in the SmC phase is inferred from the layer spacing data. To examine the critical behavior near the nematic to smectic A (NA) and smectic A to the smectic C (AC) phase transitions, we evaluate the critical exponents: α from specific heat capacity, β from the fitting of the temperature-dependent tilt angle, and νǁ
, ν
⊥ from the temperature-dependent longitudinal (ξǁ
) and transverse (ξ
⊥) correlation lengths. Modulated Differential Scanning Calorimetry (MDSC) measurements indicate the absence of phase shift, latent heat and imaginary specific heat capacity, suggesting that the AC transitions are second-order for all binary mixtures. The results obtained from heat capacity reveal that both the AC and NA transitions exhibit non-universal behaviors with effective exponents lying between the tricritical and 3D-XY values and follow nearly identical curve with decreasing width of the Sm-A and N phases. The Josephson hyper scaling relation is verified for both the NA and AC transitions in different mixtures. Moreover, knowing the heat capacity critical exponent α and the order parameter critical exponent β, the susceptibility critical exponent γ for the AC transition can be estimated from Rushbrooke equality α + 2β + γ = 2, with γ values ranging from 1.015 to 1.313, indicating the system’s crossover character and apparently validating the Rushbrooke equality.
A hybrid piezoelectric–electromagnetic body energy harvester: design and experiment validation
Authors: Guo Hui , Wang Jinyue , Dong Ruihong , Song Yuanyuan , Zhou Ran , Jin Junjie , Xu Fangchao , Sun Feng
Published: November 2024

The rapid advancement of electronic devices and wireless sensors has heightened the demand for energy sustainability and portable power solutions. Traditional human energy harvesters have limitations in harvesting energy from ultra-low-frequency human motion due to issues related to unstable energy output and wearing comfort. To address this challenge, a piezoelectric–electromagnetic hybrid energy harvesting (HP-EEH) structure designed for the hip joint area. This innovative design employs magnetically coupled frequency boosting alongside electromagnetic energy capture to achieve high output power. Firstly, the structure and principle of the energy capture device are introduced, and the electromechanical coupling model of the energy harvester is derived using Hamilton’s principle. Furthermore, the system is numerically simulated, and the voltage output characteristics of the piezoelectric unit and the electromagnetic unit are analyzed by using the finite element analysis software. Finally, the experimental setup of the (HP-EEH) is constructed, and the voltage output characteristics are tested for different swinging angles and positions. The results show that two parts of energy can be captured simultaneously under ultra-low-frequency motion conditions. At a swing angle of 50 degrees, the piezoelectric and electromagnetic units achieved maximum output power values of 14.96 µW at 0.8 Hz and 10.4 µW at 1.2 Hz, respectively. Incorporating the output power of the electromagnetic unit aims to address the power consumption requirements of low-power devices better.
Numerical determination of the threshold magnetic field in superconducting strips and coils triggering dynamic resistance
Authors: Sun Yueming , Ma Jun , You Shuangrong , Badcock Rodney A , Jiang Zhenan
Published: November 2024

The threshold magnetic field is a key parameter for evaluating the current decay caused by dynamic resistance in superconducting windings and magnets. For a direct current-carrying superconducting slab under an AC parallel magnetic field, the analytical theory clearly shows that there is only one electric central line (ECL) across the slab width at the onset of dynamic resistance. However, threshold magnetic fields in superconducting strips and coils have not been fully investigated. Based on the one-ECL criterion, this paper first presents a method for numerically determining the threshold magnetic field via the evolving internal magnetic field in superconducting strips and coils. By probing transient electromagnetic behaviours, interestingly, we found a distinctive feature of superconducting strips in which a wide region of zero electrical field is observed when dynamic resistance/loss initially occurs. With increasing magnetic fields, this region gradually shrinks and eventually becomes the ECL. More importantly, this numerical method can analyse the local threshold magnetic field in a targeted coil turn. The ability to quantify threshold magnetic field provides clear guidance on the acceptable level of ripple and harmonic magnetic fields for coil windings in superconducting maglev trains and field windings of superconducting machines operating at persistent current mode.
Tensile strain-induced disorder and weak localization in SrRuO3 thin films on (100) KTaO3 substrates
Authors: Alka Km , Chauhan Shital , Singh Sandeep , Siwach P K , Singh H K
Published: November 2024

SrRuO3 (SRO) thin (∼12 nm) films have been grown on KTaO3 (001) substrates by RF magnetron sputtering. The as-prepared films are under enormous in-plane tensile strain, which corresponds to the elastic energy of ∼1.5 MJ. Annealing in oxygen at 900 °C for 6 h relaxes strain, partially lowering the elastic energy. The surface topography shows a transition from granularity as the Ar+O2 pressure increases from 5 mTorr to 200 mTorr, with a simultaneous change in the average surface roughness from 4 nm to 0.8 nm. Annealing transforms the topography to island-type and enhances surface roughness. The films deposited at 5 mTorr are semiconducting, and annealing further enhances the resistivity. The ρ-T of films grown at 200 mTorr shows a metallic behavior with an inflection in the ρ-T at TC ∼ 150 K, FM transition. The low-temperature resistivity upturn shows the disordered nature of these films. The eq.

ρ

T

=

1

σ

0

+
a

T

1

2

+

a

1

T

p

2

+
b

T

α

(p = 2 & α = 2) describes the transport behavior from 2 K to 300 K of 5 mTorr deposited films. In the 200 mTorr deposited film, the above eq. is valid at T < 95 K with p = 2 and α = 1.5. At TC < T ≤ 300 K, the ρ-T follows eq.

ρ

T

=

ρ

0

+

ρ

1

T

α

with α = 1.3 and 1.5 for the as-grown and annealed films. The lower temperature ρ-T upturn appears to have contributions from the disorder-enhanced renormalized e-e interaction (REEI) and weak localization (WL) effects. The magnetoresistance behavior supports a substantial WL effect in the films grown at 200 mTorr. Our results establish a strong correlation between the nature of strain, surface topography, and carrier transport mechanisms.
Study of compact traveling-standing wave relativistic folded waveguide oscillator with low magnetic field operation
Authors: Xue Yuzhe , Xu Che , Du Chuangzhou , Liu Qingxiang
Published: November 2024

In this article, a compact Traveling-standing Wave Relativistic Folded Waveguide Oscillator (TSW-RFWO) is proposed, leveraging a 0.3 T guiding magnetic field to address the crucial needs for miniaturization and practicality in high-power microwave systems. The study conducts a thorough analysis of the electromagnetic characteristics of the TSW-RFWO. Its internal traveling-standing wave signal is analyzed. Utilizing the traveling-standing wave slow-wave structure (TSW-SWS), the TSW-RFWO obtains a low Q

e
(external quality factor) of 39. The necessity of compacting the high-power device under low magnetic guiding field is analyzed. Employing a 300 kV, 400 A circular electron beam within a 0.3 T guiding magnetic field, PIC simulations indicate a potential output power of 57 MW at 2.74 GHz, achieving an efficiency of 47.5%.
Investigation of freezeout parameters and other thermodynamic quantities with changing pseudorapidity at 0.9 TeV in pp collisions
Authors: Waqas Muhammad , Hassan Belqees , Alnakhlani Ali , Saidani Taoufik , Ajaz Muhammad , Al Bahir Areej , Haj Ismail Abd Al Karim
Published: November 2024

The charged particles in different pseudorapidity intervals are analyzed by the thermodynamically consistent Tsallis distribution at 0.9 TeV in proton-proton collisions. We extract the effective temperature, T, and the non-extensive parameter, q. The former decreases while the later increases toward the forward pseudorapidities. Using the parameters T and q obtained from the Tsallis distribution, we calculate the particle density, n, energy density, ε, pressure, P and squared speed of sound, c2

s
at kinetic freezeout. All these quantities are larger at mid-pseudo-rapidity and decrease towards the forward pseudo-rapdity regions.
Analysis of a chronological age-structured epidemic model with a pair of optimal treatment controls
Authors: Das Riya , Das Dhiraj Kumar , Kar T K
Published: November 2024

Emerging infectious diseases are one of the core concerns in epidemiology, and they often lead to a global public health emergency and consequently affect socio-economic sectors. The risk of contracting an infection varies with different age groups in a population. In this investigation, we present a continuous age-structured epidemic model that incorporates a chronological age-dependent bilinear disease incidence rate. We establish the model’s feasibility from the population perspective and derive the basic reproduction number,

R

0

. The analysis reveals that the model consistently exhibits a disease-free equilibrium, and a unique endemic equilibrium emerges whenever

R

0

>
1

. Furthermore, the value of

R

0

determines the stability of the age-structured model. We further formulate an optimal control problem by introducing a pair of age-dependent control variables, namely, (i) pre-cautions or medical care to the latently infected individuals and (ii) treatments or hospitalization of the infected individuals. We aim to minimize the cost of implementing these two controls so that the severity of an epidemic can be mitigated. We derived the adjoint equations to the age-dependent optimal control problem using Gateaux derivatives, then proved the existence and uniqueness of optimal control solution pair using Ekeland’s principle. Finally, numerical simulations are conducted to verify the analysis and visualize the solution profiles of the model. Our observations suggest that while both control measures are effective in reducing the impact of the disease, taking precautions proves to be significantly more effective in mitigating the spread of the epidemic.
Three perspectives on entropy dynamics in a non-Hermitian two-state system
Authors: Felski Alexander , Beygi Alireza , Karapoulitidis Christos , Klevansky S P
Published: November 2024

A comparative study of entropy dynamics as an indicator of physical behavior in an open two-state system with balanced gain and loss is presented. To begin with, we illustrate the phase portrait of this non-Hermitian model on the Bloch sphere, elucidating the changes in behavior as one moves across the phase transition boundary, as well as the emergent feature of unidirectional state evolution in the spontaneously broken

P
T

-symmetry regime. This is followed by an examination of the purity and entropy dynamics. Here we distinguish the perspective taken in utilizing the conventional framework of Hermitian-adjoint states from an approach that is based on biorthogonal-adjoint states and a third case based on an isospectral mapping. In this it is demonstrated that their differences are rooted in the treatment of the environmental coupling mode. For unbroken

P
T

symmetry of the system, a notable characteristic feature of the perspective taken is the presence or absence of purity oscillations, with an associated entropy revival. The description of the system is then continued from its

P
T

-symmetric pseudo-Hermitian phase into the regime of spontaneously broken symmetry, in the latter two approaches through a non-analytic operator-based continuation, yielding a Lindblad master equation based on the

P
T

charge operator

C

. This phase transition indicates a general connection between the pseudo-Hermitian closed-system and the Lindbladian open-system formalism through a spontaneous breakdown of the underlying physical reflection symmetry.
Unravelling the electrochemical impedance spectroscopy of hydrogenated amorphous silicon cells for photovoltaics
Authors: Prayogi Soni , Ristiani Deril , D Darminto
Published: November 2024

This research reveals the application of electrochemical impedance spectroscopy (EIS) in analyzing and improving the performance of hydrogenated amorphous silicon (a-Si: H) based photovoltaic cells. As a non-destructive technique, EIS provides deep insight into the electrochemical characteristics of photovoltaic cells, including series resistance, layer capacitance, recombination mechanisms, and charge transport. The impedance data is obtained and analyzed using small AC potential signals at various frequencies via Nyquist diagrams and Bode plots. This analysis allows the identification of resistive and capacitive elements as well as the evaluation of the quality of the interface between the active layer and the electrode. The results show that EIS can identify internal barriers that reduce the efficiency of a-Si: H solar cells, such as dominant recombination mechanisms and inefficient charge transport. Using equivalent circuit models, electrochemical parameters are extracted to reveal cell behavior and performance. In addition, these results also confirm that EIS is an important tool in design optimization and performance improvement of a-Si: H photovoltaic cells, providing a solid scientific basis for the development of more efficient and sustainable solar cell technology. These findings contribute to efforts to increase solar energy efficiency, supporting broader and more effective use of photovoltaic technology in meeting global sustainable energy needs.
Inelastic scattering effects on the inhomogeneous transverse conductivity of liquid metals and plasmas
Authors: Kitamura Hikaru
Published: November 2024

On the basis of the quantum Wigner density operator formalism for multicomponent charged particle systems, the wavenumber (k)- and frequency (ω)- dependent transverse conductivity

σ

T

(
k
,
ω
)

of simple liquid metals is presented for homogeneous (k = 0) and inhomogeneous

k
≠
0

electric fields separately. The theory takes into account correlated density fluctuations of electrons and ions, with their mutual inelastic scattering being described by the ionic dynamic structure factors. Since homogeneous and inhomogeneous fields perturb the diagonal and off-diagonal elements of the density matrix, respectively, the corresponding transport equations exhibit a dissimilarity in their collision terms. In both cases, approximate solutions to the transport equations yield a conductivity of generalized Drude form characterized by the k- and ω-dependent complex relaxation time. It is shown that the

k
→
0

limit of the inhomogeneous conductivity,

σ

T

k
→
0
,
ω

,

coincides with the homogeneous one

σ

ω

in classical ion regime such that

β
ℏ

ω

i

≪
1
,

where β is the inverse temperature and ω
i is a characteristic frequency of ionic density fluctuation; this condition may be satisfied for metals well above melting. At lower temperatures, it is suggested that the (homogeneous) DC conductivity

σ

(
0
)

exceeds the (inhomogeneous) optical conductivity extrapolated to zero frequency,

σ

T

k
→
0
,
0

.

This trend is qualitatively consistent with earlier observations for liquid polyvalent metals.
A frequency reconfigurable antireflection metasurface for GPR
Authors: Li Bo , Guo Linyan , Peng Zhan , Cui Yixin , Guo Li
Published: November 2024

The antireflection metasurface (AM) is employed in ground penetrating radar (GPR) to mitigate the strong reflection of electromagnetic waves at the air-ground interface due to impedance mismatch. However, due to constraints imposed by the relative bandwidth (RBW) and manufacturing processes, these layers tend to exhibit excessive thickness and bulky shape, narrow RBW, and fixed functionality in a passive configuration. This paper presents a novel, dual-band, independent wideband tuning, frequency reconfigurable AM based on varactor diodes with center frequencies of 1.35 GHz and 2.60 GHz. This metasurface possesses positive properties such as a single layer, the ultrathin thickness (0.03 & 0.06λ), the wide RBW (43.3% & 27.4%) and remarkable antireflection. The aforementioned metasurface achieves the described mechanisms and features through the destructive interference theory and the combine element technique. Numerical simulation results of surface currents and electric field energy power demonstrate the antireflection property. The equivalent electromagnetic parameter retrieval results also provide equivalent impedance conditions for non-perfect antireflection. The proposed AM samples demonstrate notable stepwise frequency reconfigurable properties in free-space experiments. The imaging effect after loading this AM is significantly improved in real-world GPR ballast roadbed anomaly detection experiments. This approach provides significant research value and promising prospects across various disciplines, including the stepped-frequency GPR, microwave imaging, and interdisciplinary fields.
Enhancing the electrochemical characteristics of P2-Na0.7Mn0.6Cu0.3Cr0.1O2 cathode materials through morphological manipulation: assessment of rate capability and coulombic efficiency
Authors: Zairov Rustem R , Mohammed Adil Ismael , Abbas Al-Anbari Hayder Hamid , Mansoor Aseel Salah , Radi Usama Kadem , Idean Amir H , Bahair Hala , Janani Baadal Jushi , Fallah Amer Ramadan
Published: November 2024

Manganese-based layered oxides are regarded as an excellent cathode material for Na-ion batteries. These materials are susceptible to phase transitions, which result in structural instability and constrain their reversible capacity. Layered self-assembled microsphere-type cathodes Na0.7Mn0.6Cu0.3Cr0.1O2 were developed to modify the efficiency of sodium-ion batteries through a technique focused on controlling morphology. The incorporation of organic compounds such as benzoic acid employs molecular design techniques to modify intermolecular interactions and increase the spacing between layers. The self-assembled layered spherical architecture enhances the interface between the cathode and electrolyte, thereby markedly boosting the transport efficiency of sodium ions. Based on the cathode for batteries, it demonstrates a substantial initial capacity of 200.26 mAh g−1 at a current density of 26 mA g−1 within the voltage amount of 1.5–4.1 V, with a capacity retention of 82.69% after 100 cycles.