bluuebunny/crossref_metadata_2025 huggingface dataset:
Advanced Control Strategies for Multilevel Inverters in Renewable Energy Systems: Enhancing Power Quality and Efficiency
Authors: Adnan Myasar Mundher , Sharma Ashish , Saravanan T. , R Reena , Bhagat R.K. , Jolad Bhuvaneshwari , Naidu K. Kumaraswamy
Published: November 2024

Multilevel inverters play a critical role in renewable energy systems by enabling efficient power conversion and enhancing power quality. With the increasing integration of renewable energy sources, such as solar photovoltaic (PV) and wind, there is a growing need for advanced control strategies to ensure reliable operation and minimize harmonic distortion. This paper explores various control techniques for multilevel inverters, focusing on improving the quality of power delivered to the grid and reducing energy losses. The proposed strategies include the use of pulse width modulation (PWM) schemes, artificial intelligence (AI)-based controllers, and hybrid control algorithms to enhance the performance of multilevel inverters. Simulation results demonstrate that these advanced control strategies effectively improve the power quality and overall efficiency of renewable energy systems. This research provides insights into optimizing multilevel inverter design for better performance in modern renewable energy applications.
Role of Wind Energy in Achieving Global Carbon Neutrality: Challenges and Opportunities
Authors: Goyal Vishal , Aishwarya M. , Cenate C F Theresa , Varghese Juvitha , Marathe Ashutosh , Bhagat Gorakh P. , Hemalatha
Published: November 2024

Wind energy is crucial in the worldwide shift towards carbon neutrality, providing a clean, sustainable, and more and more affordable substitute for fossil fuels. This study examines the present state of wind energy on a global scale, its role in mitigating carbon emissions, and the obstacles that impede its extensive implementation. Primary obstacles are financial limitations, incorporation into the power grid, ecological considerations, and governmental laws. Nevertheless, the progress in turbine design, the untapped potential of offshore wind, and the emergence of hybrid systems offer substantial prospects for expanding wind power. The article also analyzes the economic and social advantages of wind energy, including the creation of jobs and the development of rural areas, while emphasizing the significance of supportive policy frameworks. By tackling these obstacles and harnessing advancements, wind energy can play a pivotal role in attaining worldwide carbon neutrality objectives by 2050. The conversation ends with a plan for future expansion and emphasizes the crucial importance of international cooperation in fully achieving the promise of wind energy.
Renewable Energy Integration in Modern Power Systems: Challenges and Opportunities
Authors: Prasad M. Bala , Ganesh P. , Vinay Kumar K. , Mohanarao P.A. , Swathi Aakula , Manoj Vasupalli
Published: November 2024

The incorporation of renewable energy into contemporary power systems poses considerable obstacles and offers substantial potential as the global community shifts towards sustainable energy solutions. Renewable energy sources, including solar, wind, and hydropower, are essential for mitigating carbon emissions and addressing climate change. Nonetheless, their fluctuating characteristics present significant hurdles to grid stability, reliability, and efficiency. This article examines the intricacies of integrating renewable energy, encompassing intermittency, infrastructural constraints, and economic and regulatory challenges. Technological innovations, such energy storage devices, smart grids, and demand response tactics, provide answers to address these difficulties. The article emphasizes the economic, environmental, and technological benefits afforded by renewable integration, including the decarbonization of power systems, the promotion of innovation, and the establishment of new industries. This study delineates the trajectory towards a resilient, adaptable, and renewable energy future through an exhaustive examination of case studies and emerging trends.
Performance Enrichment in the Dynamic Stability of Multi Area Power System Network with the HVDC Line Integration
Authors: Naga Sai Kalyan Ch. , V Suresh Chintalapudi , Mishra Paritosh , Bajaj Mohit
Published: November 2024

This work tested the operational performance of the fruit fly algorithm (FFA) optimized proportional-integral plus double derivative (PIDD) controller for the dynamic stability of the electrical system. For this, a widely operated interconnected power system (IPS) model in the literature is considered, and the analysis for 10% step load disturbance (SLD) is performed. The optimization of PIDD using FFA is performed by taking the time domain indices of integral square error (ISE). The performance efficacy of the PIDD is demonstrated with the performances of other controllers. Later, the investigative IPS model is incorporated with the high voltage direct current line (HVDC) as a tie-line, and the comparative analysis of the simulation results confirmed the improvement in the electrical system's dynamical behavior with the HVDC line. Further, the sensitivity test is conducted and validates the control approach of PIDD-based FFA and the consideration of the HVDC line.
Hydrogen Production via Electrolyzers: Enhancing Efficiency and Reducing Costs
Authors: Saravanan T. , Shnain Ammar Hameed , Sharma Himanshu , Sathiya Naveena S. , Rajurkar A.U. , Sherje Nitin , Ragu Nathan S.
Published: November 2024

Hydrogen production through electrolyzers is gaining considerable interest as a sustainable energy solution, particularly in the context of reducing carbon emissions and supporting the global shift towards renewable energy. However, the widespread adoption of hydrogen as an energy carrier is hindered by the relatively low efficiency and high costs of current electrolysis technologies. This paper explores various strategies to enhance the efficiency of electrolyzers, such as advancements in catalyst development, optimization of operational parameters, and innovative system designs. Additionally, it investigates cost-reduction approaches, including improvements in material utilization, integration of renewable energy sources, and economies of scale. A comprehensive analysis is presented, focusing on recent technological advancements, their impact on hydrogen production efficiency, and the potential pathways for making hydrogen a competitive energy solution in the market.
Optimizing Solar Panel Cooling: A Smart Approach using Arduino and IoT Integration
Authors: Raju Kuruva , Priyadarshini M. S. , Asrani Anjas , Bajaj Mohit
Published: November 2024

The design and implementation of an automated cooling system for solar panels using an Arduino microcontroller, temperature sensor, voltage, relay, and Central Processing Unit (CPU) fan are detailed in this paper. The objective of the system is to enhance the efficiency of photo voltaic panels by maintaining their temperature within an optimal range. The system utilizes a temperature sensor and voltage sensor to continuously monitor the temperature of the photo voltaic panel. The Arduino microcontroller receives temperature readings from the sensor and based on the measured temperature, the microcontroller determines whether cooling is required. When the temperature exceeds a predefined threshold, the microcontroller triggers a motor driver module to switch ON the connected to a CPU fan and pump on. The motor driver controls the speed of the fan based on temperature. The fan, placed strategically near the photo voltaic panel, creates airflow that helps dissipate heat from the panel's surface. It periodically checks the temperature and controls the fan accordingly.
Cardiotocogram Data Generation using CT-GANs for Enhancement of Performance metrics used for Classification Models
Authors: Sriram A. Venkata , Kumar P. Rajesh , Alekhya L.
Published: November 2024

Autonomous Fetal distress classification is crucial to monitor the Cardiotocogram (CTG) signals for fetal well-being and ensure timely medical intervention during pregnancy. However, the imbalanced nature of the existing CTG datasets impose significant challenges in developing autonomous models. To address this issue, the study provides a novel approach in generating synthetic CTG data using Conditional Tabular Generative Adversarial Networks (CT-GANs). By augmenting the existing CTG dataset with high- quality synthetic samples from GANs, the performance metrics are enhanced with this approach. The obtained results of the synthetic CTG data classification with algorithms namely k-NN and Random Forest with and without Grey Wolf optimisation are compared with the same classification models of Imbalanced CTG data. Hence the approach of Random Forest model with Greywolf optimization for CT-GANs generated balanced data outperforms most widely used techniques with an Overall accuracy of 94.49%, mean sensitivity of 95.23%, mean specificity of 97.7%, mean precision of 95.31%, mean MCC of 91.68% mean Kappa score of 91.63%, Weighted F1-score of 94.50% and averaged AUC-ROC of 99.40% with Random Forest algorithm for multiclass classification of CTG synthetic data.
Comparative Study on Light Weight Concrete by using Light Expanded Clay Aggregate and Pumice Stone
Authors: VarshaSri K. , Vishnu Vardhan G. , Swathi K. , Prasanna D. , Chandini R. , Poojith G. , Ramana Nayak R.
Published: November 2024

In order to increase compressive strength while decreasing thickness and weight, lightweight concrete is crucial to the construction of concrete. By including clay and pumice into the composite, the study focuses on analyzing the qualities of the composite sample (M20) both when it is fresh and when it has hardened. Our unique mixes, which each have three cubes and three cylinders, are made to measure compressive and bending strength in addition to mix control. This study also looks into adding different mineral admixtures to the concrete mixture. The test results showed that across several trials, strength and weight loss improved concurrently. Thus, it can be said that lightweight aggregates have greater qualities than pumice stone and regular concrete, particularly lightweight expanded clay aggregate stone.
Experimentation and Analysis of Hybrid Bio-Composites
Authors: Lakshmi S. , Sreedhar G. , Vijay Kumar C. , Leela Chandu S. , Guru Deepak Sai Harshith V. , Harsha Vardhan C.
Published: November 2024

Hybrid composites are commonly applied to obtain perfectly made properties due to the additive or synergistic effect between matrix and fibers, offering a wide range of properties that could not be achieved with a single fiber. However, the addition of more than one fiber makes the mechanical behavior of hybrid composites more complex, and classical approaches such as the rule of mixed. In this project, we are going to prepare a composite material with various fibers like coir, jute, banana, and bamboo with a hand-layup process. In this preparation, we will find out the various characteristics of the fiber that was produced by the hand-layup process with various types of tests, like the tensile test and the impact test.
Development of a MultiWii-Based Follow Me Drone with Camera and Obstacle Avoidance Capability
Authors: Pushpalatha N.
Published: November 2024

Drones have become increasingly popular not only as recreational toys but also as valuable tools in various applications. This paper presents the development of a follow-me drone system utilizing the MultiWii 32kB flight controller, which is based on the ATMega328 chip commonly found in the Arduino UNO. The drone is designed to autonomously track and follow a target, typically a smartphone, by utilizing GPS data. The system relies on the Android smartphone to transmit its GPS coordinates to the drone, which then compares this data with its own GPS signal to accurately track and follow the target. This functionality allows the drone to dynamically adjust its position relative to the target, enabling smooth and seamless tracking during movement. Moreover, the drone is equipped with a camera module, enabling it to capture video footage of the target as it moves. This feature enhances the utility of the drone for various applications such as sports filming, outdoor activities, and surveillance. To ensure safe operation, the drone is integrated with an ultrasonic distance sensor. This sensor enables the drone to detect and avoid obstacles in its flight path, including trees, buildings, and other obstructions. By leveraging both GPS positioning and obstacle avoidance capabilities, the drone can navigate complex environments with enhanced reliability and safety. Overall, the developed MultiWii-based follow-me drone system offers a versatile and robust platform for various applications requiring autonomous tracking and aerial surveillance capabilities in dynamic outdoor environments.
Assessment of maternal and fetal radiation exposure during CT pelvimetry in two radiology departments in Morocco
Authors: Chaanoun W. , M Chakir E. , Tahmasbi M. , Ouabi H. , Talbi M. , Bouadel I.
Published: November 2024

CT pelvimetry scans assess the feasibility of natural childbirth and predict emergency cesarean sections. However, it is crucial to evaluate the associated radiation doses. This study aimed to evaluate maternal and fetal doses from CT pelvimetry and establish local diagnostic reference levels (LDRLs) in two Moroccan departments. The study included 95 patients, using helical scan protocols with 120 kV voltage, 60 mA and 40 mA tube current, and 0.5 s and 0.4 s rotation time in departments A and B, respectively. LDRLs were based on the 75th percentile of average data. Effective doses were calculated with dose conversion factors and estimated using the ImPACT CT Patient Dosimetry Calculator, which also estimated fetal doses in a 70 kg woman. Results showed variations between departments, LDRLs of Department A exceeded those of Department B by 47.13% and 34.69% for CTDIvol and DLP, respectively. The DRLs for CTDIvol and DLP for all departments were 0.88 mGy and 34.02 mGy·cm, respectively. The mean effective dose was 0.489 mSv, and the fetal dose was 1.23 mGy. These findings help facilities identify clinical practices, compare doses with international guidelines, and identify protocols for optimization. The dosimetric assessment of other protocols is currently the subject of an ongoing study.
Smellscape Perception of Environmental Quality At Stasiun Tugu Yogyakarta
Authors: Fadhillah Nurul , Marcillia Syam Rachma
Published: November 2024

Scent brings a distinct identity to a place and connects people emotionally with the place. Scent plays an important role in eliciting emotional evaluation and user perception of environmental quality. This research aims to analyze the perception of environmental aroma in Yogyakarta Tugu Station Area as a sensory experience for visitors. The method used in this research is by conducting smellwalk, and followed by filling out questionnaires related to environmental quality (such as air quality, temperature, humidity, density) and emotional associated with odors. The result of this study is to determine the perception of smellscape that has an important influence on environmental quality.
Phenomena of Malaysian, and Japanese Languages from an Intercultural Communication Perspective
Authors: Machawan Arsyl Elensyah Rhema , Sanjaya Sonda , Zubbir Nadiah Binti
Published: November 2024

This research focuses on field findings related to the phenomena of Malaysian, and Japanese languages from an intercultural communication perspective, encompassing language phenomena in written and spoken forms. Additionally, the research aims to understand the dynamics of interpersonal communication interactions across cultures as experienced firsthand. Employing a qualitative method, supplemented with an ethnographic approach tailored to how researchers gather data, this study examined Japanese language phenomena and language phenomena used in the Malayan Peninsula region (Singapore and Malaysia) over five days. The research findings, which have practical implications, indicate that while Indonesian and Malaysian languages share the same Latin-based writing system, there are vocabulary differences that can confuse users of both languages. In oral contexts, misunderstandings of certain expressions that can lead to miscommunication occur, despite the shared characteristics between Indonesians and Malaysians. On the other hand, the Japanese written language reflects the population of Japanese residing in regions using the Japanese script. Japanese language phenomena in spoken form reveal the use of mixed English and Japanese, informal language when meeting new people, and discussions related to privacy during initial introductions.
Creating a Smart Learning Environment for English Proficient Students: Parental Involvement
Authors: Rejeki Murtiningsih Sri , Ayuningtyas Sekar , Haryadi Didit
Published: November 2024

Parental involvement is crucial in fostering a smart learning environment, particularly for enhancing English proficiency among students. This study examines the role of parents in creating such an environment and the challenges they face. Using qualitative approach, in-depth interviews were conducted with four parents of students with high English proficiency at an Islamic elementary school in Magelang, Indonesia. The findings highlight various forms of parental involvement, including English learning support, provision of learning facilities, supervision during study sessions, collaboration with schools, and mental support. The research also identifies six key challenges: teaching English at home, supporting English learning, unsupportive academic backgrounds, low parental skills, busy schedules, and managing emotions. These insights are vital for developing strategies that enhance parental involvement to create smart learning environments and ultimately improve students’ English proficiency. Implications for parents, institutions, and further research are discussed in this study.
English Teachers’ Pedagogical Competences in Using Learning Management System (LMS)
Authors: Wirantaka Andi , Syaharani Nabila , Baharun Hazleena
Published: November 2024

Learning management system (LMS) becomes a platform that is used in the teaching and learning process. Good pedagogical competencies are a requirement the teachers have to maximally teach students, especially in the context where LMS is used. This study aims to determine the kinds of teachers’ pedagogical competence teachers should have in the Learning Management System (LMS) and to determine the benefits students obtain if the teachers have good pedagogical competence in using LMS. This research used a descriptive qualitative under qualitative approach. There are six participants from the English Language Education Department. The first finding related to students’ perception of the pedagogical competence that the teachers should possess in teaching using LMS includes mastering the material, organizing the material, communicating effectively, and evaluating after the learning process. The second finding is related to the benefits students have as the effect of good pedagogical competencies teachers possess is that it makes students motivated, makes the material easy to understand the material, makes learning more organized, and increases student engagement.
Understanding students’ perceptions of the challenges of teaching in the fourth industrial revolution in a private university in Yogyakarta
Authors: Agustina Noor Qomaria , Pratama Oktrin Yudha , Zahidah Nisrina , Yuari Chiara Verrell , Reyfaldy Muchamad Ikhsan
Published: November 2024

Alongside with the development of technology of 4.0 Industrial Revolution, the new teaching approaches also have changed to be more effective because of the technology integration. Students and teachers need to be keen on the use of technology in their teaching and learning process. Understanding digital competence in the classroom is crucial for supporting language instruction within the context of this industrial revolution. Qualitative research design was used in this study and employ semi-structured interviews to obtain insight from the participants. The research highlights significant challenges in teaching language, such as high course fees for skill updates, unequal distribution of human resources, limited technological resources in the classroom, and unprepared teaching abilities. The empirical evidence from this study underscores the importance of integrating technological competence into teacher education, preparing educators for the pervasive use of technology in both personal and professional realms in this era of advanced technology.
Predictors for length of stay after surgical aortic valve replacement
Authors: Arndt Nico , Demal Till , Bhadra Oliver D , Ludwig Sebastian , Grundmann David , Voigtlaender-Buschmann Lisa , Waldschmidt Lara , Hannen Laura , Blankenberg Stefan , Kirchhof Paulus , Conradi Lenard , Reichenspurner Hermann , Schofer Niklas , Schaefer Andreas
Published: November 2024

Aortic valve replacement improves and prolongs lives of patients with aortic valve disease, but requires significant healthcare resources, which are mainly determined by the length of associated hospital stays. Therefore, this study aims to identify risk factors for extended length of stay after surgical aortic valve replacement.

Between 2018 and 2023, 458 consecutive patients underwent isolated surgical aortic valve replacement at our center and were included in our analysis. To identify independent predictors for hospital and intensive care unit stay, multivariable linear regression analysis using backward elimination process was performed.

Upon multivariable linear regression, endocarditis [regression coefficient (β) 2.98; 95% confidence interval (CI) 1.51, 4.45; p<0.001)] and prior aortic valve surgery (β 1.72; 95% CI 0.18, 3.26; p=0.029) were associated with prolonged hospital stay. Prior aortic valve surgery was associated with prolonged intensive care unit stay (β 0.99; 95% CI 0.39, 1.59; p=0.001) as well as chronic obstructive pulmonary disease (β 1.61; 95% CI 0.66, 2.55; p=0.001), smaller prosthetic valve sizes (β -0.18; 95% CI -0.30, -0.06; p=0.003), preoperative atrial fibrillation (β 1.06; 95% CI 0.32, 1.79; p=0.005), and reduced left ventricular ejection fraction (β -0.03; 95% CI -0.05, -0.01; p=0.006).

Pending further validation, structured programs aiming to accelerate intensive care unit and hospital discharge after surgical aortic valve replacement should focus on patients with prior cardiac surgery, atrial fibrillation, and chronic obstructive pulmonary disease. Surgeons should aim to implant large-diameter valves. Furthermore, the identified predictors should be used to discuss surgical versus transcatheter procedures in the interdisciplinary heart team.
Facilitators and Barriers to Integrating Patient-Generated Blood Pressure Data into Primary Care EHR Workflows
Authors: Canfield Shannon M. , Koopman Richelle J.
Published: November 2024

Background Evidence supports using patient-generated blood pressure data for better outcomes in hypertension management. However, obstacles like dealing with home-generated paper data sets and questions of validity slowed the meaningful incorporation of home blood pressure into clinical care. As clinicians value patient data more, reliance on digital health solutions for data collection and shared decision-making grows.

Objectives The purpose of this study is to evaluate the design and early implementation of an electronic health record (EHR)-based data visualization tool and explore the barriers or facilitators to integrating) patients' home blood pressure data into the electronic workflow in the clinical setting. Findings can inform potential next steps for implementation and provide recommendations for leveraging patient-generated health data (PGHD) in hypertension management.

Methods We qualitatively explored pre- and early-implementation factors for integrating PGHD into clinicians' EHR interfaces intended to support shared decision-making using the Consolidated Framework for Implementation Research (CFIR). We collected data in the form of notes and transcripts from clinician focus groups, administrative leadership feedback sessions, research team observations, and recurring team meetings. This study took place at a midwestern academic health center.

Results We identify implementation facilitating factors, adoption considerations, and next steps across CFIR domains focusing on large-scale implementation. Key recommendations include aligning internal and external priorities, empowering champions to facilitate uptake, using intuitive design, and anticipating and planning for unintended consequences.

Conclusion These findings can guide future efforts to include PGHD in workflows, thus enhancing shared decision-making and laying the groundwork for larger implementations. Understanding the implementation barriers and facilitators to connect PGHD to clinician apps in the EHR workspace can promote their adoption and maintenance.
Trans* & gender identity in the premodern Mediterranean
Authors: McDonough Susan , Armstrong-Partida Michelle
Published: November 2024

This paper explores the intersection and imbrication of transness and Mediterraneaness in the premodern period. How did Mediterranean mobility, spaces, and creativity inform and make possible the ‘transing’ of gender? Re-examining previously considered sources with the benefit of recent scholarship on archival silences and trans history, we suggest that Mediterranean culture, migration, local community, and race shaped possibilities for transgender people. Prioritizing the agency of people who lived non-binary and trans lives, we make them legible to a contemporary audience while refraining from imposing our own labels upon them. The messy and contradictory lives of our subjects show the complexity of personhood and identity. We consider unrecorded suffering and reflect on how the physical bodies of those punished for transgressing gender norms were inscribed with meaning that resonated with hegemonic constructions of sexuality and identity. We center the bodies, identities, and experiences of trans people rather than the elite male discourses of a heteronormative society.
Dynamical behavior of a stochastic epidemic model with general incidence rate and Black-Karasinski process
Authors: Cao Hong , Liu Xiaohu , Nie Linfei
Published: November 2024

Epidemics pose a serious threat to public health, and effective disease control measures are necessary. Vaccination is one of the most effective strategies. Considering the huge benefits of vaccination and the unpredictability of changes in the natural environment, we propose and investigate a stochastic susceptible-vaccinated-infected-recovered epidemic model with general incidence rate and mean-reversion process by incorporating the Black-Karasinski process into the vaccination strategy model. Firstly, the existence and uniqueness of the global solution of the model are proved theoretically. Then, by constructing several suitable Lyapunov functions and a compact set, the existence of the stationary distribution for the model is obtained. In addition, by solving the corresponding Fokker-Planck equation and using the related algebraic equation theory, the probability density function of the model around the quasi-endemic equilibrium is derived. Finally, some numerical simulations are employed to explain our theoretical results.
A fully automatic and robust hybrid Reynolds-averaged Navier–Stokes/large eddy simulation approach based on the Menter shear stress transport k–ω model
Authors: Renard Nicolas , Vaquero Jaime , Gand Fabien , Deck Sébastien
Published: November 2024

A robust hybrid Reynolds-Averaged Navier–Stokes (RANS)/Large Eddy Simulation (LES) strategy is proposed for a treatment of attached turbulent boundary layers with the RANS Menter Shear Stress Transport (SST) k–ω model irrespective of the grid density and pressure gradient and a quick RANS/LES switching after separation which is automatic, i.e., without shielding-related meshing constraints for the user. This formulation of Zonal Detached Eddy Simulation (ZDES) mode 2 (2020) initially based on the Spalart–Allmaras RANS model relies on local flow quantities providing a RANS shielding identified as a critical limitation of most popular RANS/LES models. The flow sensors are adapted for the SST context and calibrated on RANS boundary-layer-equation solutions over a wide Reynolds-number and pressure-gradient range approaching flow separation and on full Navier–Stokes RANS solutions with separations. The Reynolds-invariant protection includes the outer part of the boundary layer profile, crucial in adverse pressure gradients but ignored by older protection functions such as fd of Delayed Detached Eddy Simulation (DDES) (2006). The shielding resistance to infinite mesh refinement is demonstrated in a flat-plate boundary layer. A second test case involving a backward-facing step shows that the enhanced protection has no detrimental impact on the quick RANS/LES switching thanks to the efficient detection of separation and reinforced destruction of eddy viscosity in gray areas. This indicates that the proposed ZDES mode 2 (2020) Menter SST k–ω achieves safe and automatic RANS shielding of attached boundary layers and efficient RANS/LES switching in massive flow separations, paving the way for its application.
3D PIC/MCC simulation of laser-guided streamer discharges in atmospheric air
Authors: Yuan Xu-Chu , Sun An-Bang , Li Han-Wei , Li Hao-Lin , Zhang Xing
Published: November 2024

Powerful lasers hold promise for guiding streamer discharges in air, with applications ranging from plasma etching to lightning control. This paper numerically investigates the guidance of positive streamers by laser-produced pre-ionization (a uniform ionization trail consisting of free electron-ion pairs) in air with a 3D PIC/MCC model. Initially, the streamer grows toward the laser beam due to the electrostatic attraction caused by charge separation within the laser channel. As laser-produced electrons drift near the streamer, they trigger electron avalanches, forming a distinct “laser-produced streamer branch”. This branch then propagates along the laser path, influenced by both electrostatic repulsion from the laser's positive ions and the guiding effect of the laser's electrons. By decoupling the impact of laser-produced pre-ionization on the electric field and free electron distribution, our simulations reveal that free electrons are the dominant factor for guiding. However, the electrostatic effect is enhanced at higher laser densities and can also guide the streamer individually. The formation of laser-guided streamers is primarily determined by whether laser-produced electrons can form a self-sustaining streamer branch. This process is highly dependent on the initial laser intensity and the electric field where the laser electrons connect with the streamer. Additionally, when the laser beam is positioned closer to the streamer, the effectiveness of laser guiding is significantly enhanced, and the number of streamer branches is greatly reduced. The angle of the laser beam also affects guiding due to variations in the electric field at the laser–streamer connection point.
Strain-dependent magnon transport in CoFe2O4/NiO/CoFe2O4 junctions induced by bulk acoustic waves
Authors: Ling Hanbing , Wu Yao , Ge Xu , Ye Zhao , Dong Tianwen , Miao Ling , Luo Wei , Zhang Yue , Fu Qiuyun
Published: November 2024

A magnon junction consisting of ferromagnetic/antiferromagnetic/ferromagnetic insulators can manipulate the transmission of magnon current through adjusting magnetic moment alignment, offering potential for ultra-low power magnon circuits. This study employs density functional theory calculations and atomic simulations to investigate the strain-dependent modulation of magnon current transport in CoFe2O4/NiO/CoFe2O4 junctions induced by bulk acoustic waves. Our results demonstrate that strain significantly alters the magnetic anisotropy energy of both NiO and CoFe2O4, with NiO favoring in-plane magnetic anisotropy under various strains and CoFe2O4 exhibiting a transition from in-plane to perpendicular magnetic anisotropy. Additionally, controlling the magnetic anisotropy energy of NiO and CoFe2O4 allows for the regulation of magnon current transmission, providing a novel approach to optimize magnonic device performance. These findings highlight the potential of strain as a tunable parameter in the design of advanced magnonic devices.
Upconversion of phonon modes into microwave photons in a lithium niobate bulk acoustic wave resonator coupled to a microwave cavity
Authors: Parashar S. , Campbell W. M. , Bourhill J. , Ivanov E. , Goryachev M. , Tobar M. E.
Published: November 2024

The coupling between acoustic vibrations in a lithium niobate bulk acoustic wave resonator and microwave photons of a re-entrant microwave cavity was investigated at a temperature close to 4 K. Coupling was achieved by placing the acoustic resonator in the location of the re-entrant cavity electric field maxima in a symmetric “split-post” configuration with a large overlap between the microwave field and the acoustic mode, allowing acoustic modulations of the microwave frequency. We show that the acoustic modes in this setup retain large inherent quality factors of greater than 106. A maximum optomechanical coupling rate was determined to be g0 = 0.014 mHz, four orders of magnitude larger than previous results obtained using a quartz BAW at 4 K in a similar experimental setup but using a single post-re-entrant cavity resonator.
Experimental investigation of the cavitation control in a convergent–divergent nozzle using air injection
Authors: Singh Santosh Kumar , Duth Praveen S. , Kumar Pankaj , Kadivar Ebrahim , el Moctar Ould
Published: November 2024

Detailed investigation of cavitation dynamics in a converging–diverging nozzle using air injection at different injection positions is carried out. Air is injected at upstream and downstream points of the nozzle to evaluate its influence on cavitation phenomena, as reported for the first time. The water and air flow rates varied from 3000 to 6000 Liter per hour (LPH) and 5–10 LPH, respectively. Cavitation phenomena are captured by high-speed cameras at different stages of cavitation, including sheet and cloud. Particular attention is given to estimate cavitation length, cavity area, and energy distribution by image processing. Very distinct frequencies are identified for different air injection flow rates and their locations, reflecting a strong correlation between cavity dynamics and air injection. Additionally, continuous Morlet wavelet transform is applied to the data, which suggests the coexistence of bubbles with multiple frequencies at any given instance; their amplitude is very notable with time. Altering the injection points results in varying bubble lengths and distributions along the channel, highlighting the crucial role of injection location in optimizing cavitation efficiency. These findings offer valuable insights into the mechanisms governing cavitation control.
Development of a compact and portable diamond-based detection system for dosimetry and microdosimetry in ion beam therapy
Authors: Verona C. , Fabbri A. , Fazzi A. , Bianchi L. , Conte V. , Petringa G. , Raso A. , Rinati G. Verona
Published: November 2024

Ion beam therapy techniques have advanced significantly in the past two decades. However, the development of dosimetric verification methods has lagged. Traditional dosimetry, which offers a macroscopic view of the absorbed dose, fails to address the micrometric-scale stochastic effects crucial for understanding biological responses. To bridge this gap, microdosimeters are used to assess physical quantities correlated with radiation effects. This work reports on the design and testing of a novel detection system based on synthetic single crystal diamond. The system is capable of simultaneously performing dosimetric and microdosimetric characterizations of clinical ion beams. The detector incorporates two active components configured as diamond Schottky diodes, both integrated on a single crystal diamond substrate. In particular, one very small element (sensitive area 0.0078 mm2) was designed to evaluate microdosimetric metrics, while the other large one (sensitive area 4.2 mm2) was designed to measure the absorbed dose to water. Diamond detectors were characterized using the ion beam induced charge (IBIC) technique, employing a 1 MeV protons microbeam. The IBIC map of the diamond detector shows two distinct sensitive areas with quite uniform sensitivity, well contained within the metallic contact regions. Dedicated front-end electronic circuits were designed and implemented for both the dosimetric and microdosimetric signals. These circuits, along with the integrated diamond detector, were embedded in an aluminum waterproof housing to minimize electronic interference. This configuration enables a compact, portable setup compatible with water phantoms. Laboratory tests with alpha particles yielded promising results, demonstrating stable and reproducible responses with a good signal-to-noise ratio.
Vortex generator evaluation models and flow mechanisms for compressor cascade
Authors: Ren Xinyu , Meng Tongtong , Zhu Huiling , Ji Lucheng
Published: November 2024

In axial compressors, control of the secondary flow is crucial for enhancing aerodynamic performance. Among various control strategies, vortex generators (VGs) are an effective passive method combining simplicity, cost-effectiveness, and reliability. This study investigates the VG evaluation model to assess VG effectiveness in reducing total pressure loss (ω) and controlling secondary flows. The impact of parameters such as the VG placement, stagger angle α, height, and length on the flow field and underlying flow mechanisms is analyzed, and methods for selecting the design parameters are examined. The findings reveal that positioning VGs near regions with high velocity differentials and away from the suction surface significantly reduces secondary flows. Achieving a balance between reducing total pressure loss ω and controlling secondary flows requires careful selection of the stagger angle α, as well as the height and length of VG. This study presents the design characteristic curve and identifies two key VG operation mechanisms that depend on the stagger angle α. The results of this study advance the development of more efficient VG designs and deepen our understanding of their operational mechanisms.
Numerical investigation and mode analysis of the S-duct
Authors: Jiang Fan , Kontis Konstantinos , White Craig
Published: November 2024

This study investigates the flow field and turbulence characteristics within two types of S-shaped ducts through both experimental and numerical methods. The experiments include pressure measurements and constant temperature anemometry, while the numerical simulations employ the Reynolds-averaged Navier–Stokes (RANS) approach. To ensure the accuracy of the simulations, a mesh independence study was conducted, and the results were compared with experimental data. Additionally, three common turbulence models—k−ϵ, k−ω, and the shear stress transport (SST)—were tested. After comparing the two S-shaped ducts, the configuration with superior performance was selected for further unsteady simulations. Modal analysis was subsequently performed using proper orthogonal decomposition, dynamic mode decomposition, and spectral proper orthogonal decomposition. The results show that the S-shaped diffuser performs better when the diffusion rate follows an S-shaped curve rather than a linear increase. In low-velocity experiments, a 1 kHz sampling frequency and 1-second period suffice for turbulence analysis, as higher values only yield minimal differences. Regarding the simulation, although RANS simulations can match the experiment, the discrepancies with experimental data can also not be ignored. Among the three turbulence models, the SST model best matches the experiment. However, modal analysis of the transient flow field reveals that RANS makes it hard to capture turbulence details in low-speed conditions, and only the k−ϵ model has modes with clear dynamic patterns. Last, the functionalities and features of each modal analysis method are demonstrated.
Osmotic and phoretic competition explains chemotaxic assembly and sorting
Authors: Hardikar Aditya V. , Hauser Adam W. , Hopkins Terrence M. , Sacanna Stefano , Chaikin Paul M.
Published: November 2024

Microscale objects responding to chemical gradients by migrating toward or away from a preferred species is a simple yet constitutive mechanism by which transport occurs in biological organisms. Synthetic chemotaxis provides key physical descriptions of simplified systems that can be used in biological models, or in the creation of advanced responsive material systems. In this article, we provide a quantitative framework for understanding synthetic chemotaxis of microparticles which involves a competition between phoresis and osmosis. We present separate quantitative measurements of phoresis and osmosis acting on individual taxing particles, finding that phoresis follows the long-predicted

v
∼
1
/

r
2

scaling while the osmotic contribution depends on the geometry and details of the system, and must be solved on a case-by-case basis. Through this, we are able to develop a more accurate picture of particle transport at the single particle level. Equipped with this approach, we go on to describe how high concentrations of particles in a symmetric chemical gradient grow close-packed hives that reach a steady-state size tunable through light intensity or particle size. Last, we demonstrate that mixed particles experiencing the same chemical gradient will selectively migrate toward or away depending on the nature of the particle surface, thereby locally sorting out a particular species. We anticipate these results will be important in describing both biological and synthetic chemotaxis in phoretic systems and should bring a wealth of studies that take advantage of competing osmotic flows to illicit unexpected dynamic active behavior.
A closed-loop modular multiorgan-on-chips platform for self-sustaining and tightly controlled oxygenation
Authors: Jiang Nan , Ying Guoliang , Yin Yixia , Guo Jie , Lozada Jorge , Valdivia Padilla Alejandra , Gómez Ameyalli , Gomes de Melo Bruna Alice , Lugo Mestre Francisco , Gansevoort Merel , Palumbo Marcello , Calá Noemi , Garciamendez-Mijares Carlos Ezio , Kim Ge-Ah , Takayama Shuichi , Gerhard-Herman Marie Denis , Zhang Yu Shrike
Published: November 2024

To mimic physiological microenvironments in organ-on-a-chip systems, physiologically relevant parameters are required to precisely access drug metabolism. Oxygen level is a critical microenvironmental parameter to maintain cellular or tissue functions and modulate their behaviors. Current organ-on-a-chip setups are oftentimes subjected to the ambient incubator oxygen level at 21%, which is higher than most if not all physiological oxygen concentrations. Additionally, the physiological oxygen level in each tissue is different ranging from 0.5 to 13%. Here, a closed-loop modular multiorgan-on-chips platform is developed to enable not only real-time monitoring of the oxygen levels but, more importantly, tight control of them in the range of 4 to 20% across each connected microtissue-on-a-chip in the circulatory culture medium. This platform, which consists of microfluidic oxygen scavenger(s), an oxygen generator, a monitoring/controller system, and bioreactor(s), allows for independent, precise upregulation and downregulation of dissolved oxygen in the perfused culture medium to meet the physiological oxygen level in each modular microtissue compartment, as needed. Furthermore, drug studies using the platform demonstrate that the oxygen level affects drug metabolism in the parallelly connected liver, kidney, and arterial vessel microtissues without organ–organ interactions factored in. Overall, this platform can promote the performances of organ-on-a-chip devices in drug screening by providing more physiologically relevant and independently adjustable oxygen microenvironments for desired organ types on a single- or a multiorgan-on-chip(s) configuration.
EFL students’ beliefs and practices regarding pronunciation self-regulated learning
Authors: Nguyen Loc Tan
Published: November 2024

The past three decades have witnessed growing interest in pronunciation research focused on a range of topics such
as the effects of explicit phonetic instruction on second/foreign language (L2) learners’ pronunciation uptake, teachers’
pronunciation teaching practices and beliefs, pronunciation representation in prescribed textbooks, and L2 students’ perceptions
of their teachers’ pronunciation instruction. However, L2 learners’ beliefs and practices regarding pronunciation self-regulated
learning (PSRL) is under-explored. The present study examines how Vietnamese tertiary EFL learners practice PSRL and what beliefs
they hold about it. Data were collected from a questionnaire completed by 215 EFL students at a Vietnamese public university and
semi-structured interviews with ten of the students. Results showed that the students demonstrated a strong commitment to
self-practicing English pronunciation and that their PSRL practices centered on segmental features through listen-and-repeat
activities from YouTube pronunciation lesson videos and textbook audio-recordings. The study further showed that the students
believed PSRL had a positive impact on their own pronunciation but called for phonetic instruction to guide their self-practice,
followed by teachers giving feedback on their pronunciation. Implications for L2 pronunciation instruction and PSRL are
discussed.
Spin photo detector by using a CoFeB magnetic tunnel junction
Authors: Shibata Tetsuya , Mizuno Tomohito , Nojiri Takeshi , Yamane Takekazu , Hirata Yusho , Zhang Weihao , Fukuzawa Hideaki , Kasatani Yuichi , Tsukamoto Arata
Published: November 2024

Ultra-fast photoelectric conversion devices are a crucial element in photonics applications and are the subject of intense research and development. In conventional high-speed photo detectors, photoelectric charge generation in semiconductors is rooted in a mechanism that directly outputs current. Owing to the dilemma of the amount of generated charge and high-speed output, it is being faced with fundamental difficult to achieve a higher response. Spin order, rather than charge generation, also exists as a phenomenon that enables ultrafast photoresponses, and magnetic tunnel junction (MTJ) are well-known high-speed electrical detection elements for magnetic states. In this study, we experimentally confirmed the magnetic switching of photoresponsive MTJ using a practical single CoFeB free layer with a high MR ratio of 80% by irradiation with laser light. Furthermore, we experimentally confirmed the operation of the reversible photo detector, and its rise time reached an ultrafast speed of 20 ps. We named it spin photo detector and it has huge potential applications that require ultrafast photo detection.
Variational inference of effective range parameters for 3He−4He scattering
Authors: Burnelis Andrius , Kejzlar Vojtech , Phillips Daniel R
Published: November 2024

We use two different methods, Monte Carlo sampling and variational inference (VI), to perform a Bayesian calibration of the effective-range parameters in 3He–4He elastic scattering. The parameters are calibrated to data from a recent set of 3He–4He elastic scattering differential cross section measurements. Analysis of these data for E
lab ≤ 4.3 MeV yields a unimodal posterior for which both methods obtain the same structure. However, the effective-range expansion amplitude does not account for the 7/2− state of 7Be so, even after calibration, the description of data at the upper end of this energy range is poor. The data up to E
lab = 2.6 MeV can be well described, but calibration to this lower-energy subset of the data yields a bimodal posterior. After adapting VI to treat such a multi-modal posterior we find good agreement between the VI results and those obtained with parallel-tempered Monte Carlo sampling.