bluuebunny/crossref_metadata_2025 huggingface dataset:
The Aryl Hydrocarbon Receptor (AhR) Is a Novel Gene Involved in Proper Physiological Functions of Pancreatic β-Cells
Authors: Bin Eshaq Shuhd , Taneera Jalal , Anjum Shabana , Mohammed Abdul Khader , Semreen Mohammad H. , Alzoubi Karem H. , Eladl Mohamed , Bustanji Yasser , Abu-Gharbieh Eman , El-Huneidi Waseem
Published: January 2025

The Kynurenine pathway is crucial in metabolizing dietary tryptophan into bioactive compounds known as kynurenines, which have been linked to glucose homeostasis. The aryl hydrocarbon receptor (AhR) has recently emerged as the endogenous receptor for the kynurenine metabolite, kynurenic acid (KYNA). However, the specific role of AhR in pancreatic β-cells remains largely unexplored. This study aimed to investigate the expression of AhR in human pancreatic islets using publicly available RNA-sequencing (RNA-seq) databases and to explore its correlations with various metabolic parameters and key β-cell markers. Additionally, functional experiments were conducted in INS-1 cells, a rat β-cell line, to elucidate the role of Ahr in β-cell biology. RNA-seq data analysis confirmed the expression of AHR in human islets, with elevated levels observed in pancreatic islets obtained from diabetic and obese donors compared to non-diabetic or lean donors. Furthermore, AHR expression showed an inverse correlation with the expression of key β-cell functional genes, including insulin, PDX-1, MAFA, KCNJ11, and GCK. Silencing Ahr expression using siRNA in INS-1 cells decreased insulin secretion, insulin content, and glucose uptake efficiency, while cell viability, apoptosis rate, and reactive oxygen species (ROS) production remained unaffected. Moreover, Ahr silencing led to the downregulation of major β-cell regulator genes, Ins1, Ins2, Pdx-1, and Glut2, at both the mRNA and protein levels. In summary, this study provides novel insights into the role of AhR in maintaining proper β-cell function. These findings suggest that AhR could be a potential target for future therapeutic strategies in treating type 2 diabetes (T2D).
The Estrogen–Immune Interface in Endometriosis
Authors: Greygoose Emily , Metharom Pat , Kula Hakan , Seckin Timur K. , Seckin Tamer A. , Ayhan Ayse , Yu Yu
Published: January 2025

Endometriosis is a gynecologic condition characterized by the growth of endometrium-like stroma and glandular elements outside of the uterine cavity. The involvement of hormonal dysregulation, specifically estrogen, is well established in the initiation, progression, and maintenance of the condition. Evidence also highlights the association between endometriosis and altered immune states. The human endometrium is a highly dynamic tissue that undergoes frequent remodeling in response to hormonal regulation during the menstrual cycle. Similarly, endometriosis shares this propensity, compounded by unclear pathogenic mechanisms, presenting unique challenges in defining its etiology and pathology. Here, we provide a lens to understand the interplay between estrogen and innate and adaptive immune systems throughout the menstrual cycle in the pathogenesis of endometriosis. Estrogen is closely linked to many altered inflammatory and immunomodulatory states, affecting both tissue-resident and circulatory immune cells. This review summarizes estrogenic interactions with specific myeloid and lymphoid cells, highlighting their implications in the progression of endometriosis.
Novel Drug Delivery Particles Can Provide Dual Effects on Cancer “Theranostics” in Boron Neutron Capture Therapy
Authors: Fithroni Abdul Basith , Inoue Haruki , Zhou Shengli , Hakim Taufik Fatwa Nur , Tada Takashi , Suzuki Minoru , Sakurai Yoshinori , Ishimoto Manabu , Yamada Naoyuki , Sauriasari Rani , Sauerwein Wolfgang A. G. , Watanabe Kazunori , Ohtsuki Takashi , Matsuura Eiji
Published: January 2025

Boron (B) neutron capture therapy (BNCT) is a novel non-invasive targeted cancer therapy based on the nuclear capture reaction 10B (n, alpha) 7Li that enables the death of cancer cells without damaging neighboring normal cells. However, the development of clinically approved boron drugs remains challenging. We have previously reported on self-forming nanoparticles for drug delivery consisting of a biodegradable polymer, namely, “AB-type” Lactosome® nanoparticles (AB-Lac particles)- highly loaded with hydrophobic B compounds, namely o-Carborane (Carb) or 1,2-dihexyl-o-Carborane (diC6-Carb), and the latter (diC6-Carb) especially showed the “molecular glue” effect. Here we present in vivo and ex vivo studies with human pancreatic cancer (AsPC-1) cells to find therapeutically optimal formulas and the appropriate treatment conditions for these particles. The biodistribution of the particles was assessed by the tumor/normal tissue ratio (T/N) in terms of tumor/muscle (T/M) and tumor/blood (T/B) ratios using near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG). The in vivo and ex vivo accumulation of B delivered by the injected AB-Lac particles in tumor lesions reached a maximum by 12 h post-injection. Irradiation studies conducted both in vitro and in vivo showed that AB-Lac particles-loaded with either 10B-Carb or 10B-diC6-Carb significantly inhibited the growth of AsPC-1 cancer cells or strongly inhibited their growth, with the latter method being significantly more effective. Surprisingly, a similar in vitro and in vivo irradiation study showed that ICG-labeled AB-Lac particles alone, i.e., without any 10B compounds, also revealed a significant inhibition. Therefore, we expect that our ICG-labeled AB-Lac particles-loaded with 10B compound(s) may be a novel and promising candidate for providing not only NIRF imaging for a practical diagnosis but also the dual therapeutic effects of induced cancer cell death, i.e., “theranostics”.
Comprehensive Chemical Analysis of Codonopsis lanceolata Roots Using Ultra-High-Performance Liquid Chromatography–Quadrupole-Exactive–Orbitrap Mass Spectrometry
Authors: Luo Chang , Duan Zenan , Kikuchi Takashi , Otsuki Kouharu , Zhang Mi , Kambayashi Ryuichi , Ito Katsuhiko , Sugiyama Atsushi , Li Wei
Published: January 2025

The roots of Codonopsis lanceolata (Siebold & Zucc.) Benth. & Hook.f. ex Trautv. have been traditionally used for medicinal purposes across East Asia. However, their chemical constituents in Japanese-grown varieties remain uninvestigated. This study employed ultra-high-performance liquid chromatography–quadrupole–orbitrap mass spectrometry to perform a comprehensive chemical analysis of the roots of C. lanceolata cultivated in Nagano Prefecture, Japan, leveraging fragment pattern analysis of both isolated and commercially available compounds as references compounds. As a result, 27 compounds, including triterpenoid saponins (19–22), polyacetylenes (6, 15, 18), flavonoids (16, 17), phenylpropanoids (3–5, 7, 9), a lignan (10), glycolipids (8, 11–14), phospholipids (23–27), and amino acids (1, 2), were identified. Notably, a triterpenoid saponin (19) was identified as a previously unreported compound, and ten compounds (3, 6, 8, 10, 13, 17, and 23–27) were identified from C. lanceolata roots for the first time. The ex vivo study revealed that lancemaside A (22) exhibited a time-dependent vasodilatory effect on rat aortic ring specimens. These findings not only advanced the understanding of the chemical constituents and biological activity of C. lanceolata roots but also provided valuable insights for their future applications and quality control.
Molecular Findings Before Vision Loss in the Streptozotocin-Induced Rat Model of Diabetic Retinopathy
Authors: Moldovan Mădălina , Capraș Roxana-Denisa , Paşcalău Raluca , Filip Gabriela Adriana
Published: January 2025

The streptozotocin-induced rat model of diabetic retinopathy presents similarities to the disease observed in humans. After four weeks following the induction of diabetes, the rats experience vision impairment. During this crucial four-week period, significant changes occur, with vascular damage standing out as a clinically significant factor, alongside neovascularization. While redox imbalance, activation of microglia, secretion of pro-inflammatory cytokines, and neuronal cell death are also observed, the latter remains an emerging hypothesis requiring further exploration. This review is a comprehensive and up-to-date chronological depiction of the progression of diabetic retinopathy within the initial four weeks of hyperglycemia, which precede the onset of vision loss. The data are structured in weekly changes. In the first week, oxidative stress triggers the activation of retinal microglia, which produces inflammation, leading to altered neurotransmission. The second week is characterized by leukostasis, which promotes ischemia, while neural degeneration begins and is accompanied by a simultaneous increase in vessel permeability. The progression of redox and inflammatory imbalances characterized the third week. Finally, in the fourth week, significant developments occur as vessels dilate and become tortuous, neovascularization develops, and retinal thickness diminishes, ultimately leading to vision loss. Through this clearly structured outline, this review aims to delineate a framework for the progression of streptozotocin-induced diabetic retinopathy.
Biogas and Organic Manure Production from Anerobic Digestion of Rubber Plant Effluent, Gliricidia Leaves, and Inoculum: Energy Sustainability and Socio-Economic Development of Mauritania
Authors: Sidi Habib Sidahmed , Torii Shuichi , S. Kavitha Mol , Jayarajan Aravind
Published: January 2025

This study analyzed the anaerobic co-digestion of inoculum (I), rubber plant effluent (RPE) and Gliricidia leaves slurry (GLS) at different mixing ratios for the simultaneous production of methane and organic fertilizer. The results were analyzed for volatile fatty acids, pH, C/N ratio, and methane production. The organic quality of the substrate mixture before and after anaerobic digestion was analyzed for total organic carbon, total nitrogen, potassium, and phosphorus contents. This study concluded that the inoculum, rubber plant effluent (RPE), and Gliricidia leaves slurry (GLS) mixed at the ratio of 10:2:2 showed higher methane production than other experiments conducted at different mixing ratios. The nitrogen, potassium, and phosphorus contents of the substrates were increased after anaerobic digestion. However, the organic carbon content in the substrate decreased in all experiments. This research recommends the planting of rubber trees and Gliricidia maculata to promote energy sustainability and the socio-economic development of Mauritania.
The Preparation of Polyvinyl Alcohol/Silica Functional Coatings and Their Effect on the Printability of Leather Surfaces
Authors: Chu Fuqiang , Dong Hang , Chao Jilei , Wang Shuo , Sun Bing , Huang Qiqi
Published: January 2025

This study employs 3-aminopropyltriethoxysilane (APTS) to eliminate the hydrophilic hydroxyl groups on the surface of silica, followed by the use of defunctionalized silica as a filler and boric acid (BA) as a crosslinking agent to prepare a polyvinyl alcohol (PVA)/silica coating. The experimental results indicate that the coating not only reduces the inherent hydrophilicity of PVA, but also enhances the uniformity and film forming properties of the coating, providing a solid foundation for patterning leather surfaces. The characterization results show that, when the mass ratio of silica-APTS is 3.0 wt% and boric acid is 2.0 wt%, the resulting coating exhibits stable physical properties, low water absorption, moderate viscosity, and excellent smoothness. Moreover, it forms a dense film on a leather surface, effectively covering pores and smoothing the texture. Furthermore, directly printing on the modified leather surface enables the creation of clear patterns that meet the requirements for fine printing, offering an experimental basis for developing leather surface coatings with superior water resistance and printability.
Effect of Nitrogen Ratio in Sputtering on the Quality of Film Formation and Electron Emission Properties of Nitride Films
Authors: Gu Yuqing , Li Juannan , Wang Dan , Zhang Na
Published: January 2025

Nitride films such as tantalum nitride (TaN), titanium nitride (TiN) and boron nitride (BN) are widely used in aerospace and vacuum electronics. The electron emitting properties of these nitride films are of great interest due to the phenomenon of surface electron emission when the films are irradiated, leading to surface modification. In this study, we have prepared three kinds of thin films, TaN, TiN and BN, by sputtering. Then the effect of the nitrogen component on the film formation quality and the dependence of the electron emission coefficient (EEC) on the film’s physical properties were investigated. The results of elemental analysis show that by rising the nitrogen gas flow during sputtering, the N elemental ratios inside the TaN and TiN films can be increased, and the film resistivity decreases follow, while BN films do not show such a tunable characteristic of the elemental ratios or resistivity. The conductivity test results show that TaN and TiN films exhibit conductive properties like those of semiconductor materials. The proportion of N elements inside the films has a significant effect on the film conductivity, namely, the conductivity of the film shows an upward trend with the increase in the proportion of N elements. The EEC test shows that TaN and TiN films with good conductive properties have relatively low EEC values, which are generally lower than 2.10. For TaN and TiN, the test results show that the EEC decreases with the increase of the conductivity. The EEC peak values are 1.92 and 1.56 for TaN and TiN films when their resistivities are 1.45 × 10−5 Ω·m and 7.26 × 10−6 Ω·m, respectively. The EEC values of BN are larger than TaN and TiN, with an EEC peak value higher than 2.49, and the electron energy to obtain the peak value is about 250 eV. The results are instructive for revealing the electron emission regularity of nitride thin films.
Quantum Kinetic Theory of the Spin Hall Effect for Disordered Graphene with Rashba Spin–Orbit Coupling
Authors: Raimondi Roberto , Valet Thierry
Published: January 2025

The spin Hall effect for the model Hamiltonian of graphene with Rashba spin–orbit coupling is analyzed by means of a recently derived quantum kinetic theory of the linear response for multi-band electron systems. The latter expresses the interband part of the density matrix in terms of the intraband occupation numbers, which can be obtained as solutions of a Boltzmann transport equation. The analysis, which, in the case of the model here considered, can be carried out in a completely analytical way, thus provides an effective pedagogical illustration of the general theory. While our results agree with those previously obtained with alternative approaches for the same model, our comparatively simpler and more physically transparent derivation illustrates the advantages of our formalism when dealing with non trivial multi-band Hamiltonians.
A Sparse Feature-Based Mixed Signal Frequencies Detecting for Unmanned Aerial Vehicle Communications
Authors: Wang Yang , Feng Yongxin , Zhou Fan , Chen Xi , Wang Jian , Zhang Peiying
Published: January 2025

As drone technology develops rapidly and many users emerge in airspace networks, various forms of interference have caused the wireless spectrum to exhibit a dense, diverse, and dynamic trend. This increases the probability of spectrum conflicts among users and seriously impacts the quality and transmission rate of communication. How to effectively improve the detection accuracy of each frequency component in the electromagnetic space mixed signals and avoid spectrum conflicts will become one of the crucial issues currently faced by unmanned aerial vehicle (UAV) communication technologies. However, the existing methods overlook the mutual interference among the component signals as well as the noise during the frequency detection process, which affects their detection performance. In this paper, we propose a mixed-signal frequency detection method based on the reconstruction of sparse feature signals. Without information such as frequency range, bandwidth, and the number of components, it can utilize the autoencoder network to learn the sparse features of each component signal in the high-dimensional frequency domain space and construct a nonlinear reconstruction function to reconstruct each component signal in the mixed signal, thereby realizing the separation of signals. On this basis, complex dilated convolution and deconvolution are used successively to perform feature extraction on the separated signals, which enhances the receptive field and frequency resolution ability of the network for signals, reduces the interference between noise and different component signals, and realizes the accurate estimation of the number of components and carrier frequencies. The simulation results show that when SNR≥ 6 dB, the detection accuracy of the number of component signals is greater than 96.3%. The detection error and detection accuracy of component frequencies are less than 3.19% and greater than 90.7%, respectively.
Student and Staff Views on Inclusion and Inclusive Education in a Global South and a Global North Higher Education Institution
Authors: Nawire Acquilina Wafula , Musungu Sally , Kioupi Vasiliki , Nzuve Felister , Giannopoulos George
Published: January 2025

This article presents views and experiences of staff, and learners from two Higher Education Institutions (HEIs)—the University of Nairobi in Kenya and UCL in the UK—on their intuitional structures, support, and education mechanisms related to disability, international and refugee status. Inclusive education is a complex subject and often the focus is particularly placed on learners with disabilities, but this study explored several layers of diversity. The objective of this study was to investigate the views and experiences of students and staff on policies and practices of inclusion and inclusive education using two case studies, one in each university. Data were collected through surveys and interviews. Results are presented in the following areas: (1) capacity building for staff; (2) support and reporting services for all; (3) class sizes; and (4) modes of course delivery. Findings reveal that implementation of inclusion and inclusive education is still a challenge for both HEIs. The gaps identified can be used as a reference point for action. Inclusion and inclusive education are necessary to ensure the needs of every learner and staff are met. The article is structured into five sections: a brief description of inclusive education in the two HEIs, methodology, results, discussion, and conclusion.
Whole-Body Control with Uneven Terrain Adaptability Strategy for Wheeled-Bipedal Robots
Authors: Wang Biao , Xin Yaxian , Chen Chao , Song Zihao , Sun Baoshuai , Guo Tianshuai
Published: January 2025

Wheeled-bipedal robots (WBRs) integrate the locomotion efficiency and terrain adaptability of legged and wheeled robots. However, terrain adaptability is significantly influenced by the control system. This paper proposes a hierarchical control method for WBRs that includes an active force solver, a whole-body pose planner and a whole-body torque controller. The active force solver based on model predictive control (MPC) was constructed to calculate the active force from the wheeled legs to the torso to achieve the torso’s desired motion tasks. The whole-body pose planner based on the terrain adaptability strategy provides whole-body joint trajectories that can achieve dynamic balance and movement simultaneously without external sensing information. The whole-body torque controller is used to calculate whole-body joint torque based on the active force reference and joint motion reference. Finally, two simulation experiments were conducted to verify the effectiveness of the proposed method on uneven terrain.
ETFRE: Entity–Type Fusing for Relation Extraction
Authors: Shi Peilin , Zhang Bin , Liu Yingkun , Fang Cheng
Published: January 2025

This paper proposes a relational extraction framework based on entity–type information fusion by Transformer model. Relational extraction, as an important part of knowledge graph construction, has been paid much attention in recent years. The existing relational extraction and joint triple extraction models rarely use the existing entity–type information, so the semantic features of the entity–type are lost, resulting in limited model performance and difficulty in solving the ambiguity problem. In order to improve this situation, this paper proposes a framework of entity–type information fusing based on a Transformer, which can generate word vector representation with entity–type information for a specific domain. There may be different entity categories for the same word, and the corresponding relationship categories are different at that time. Through deep self-attention, word vector representation is rich in entity–type information, which benefits relationship extraction and ambiguity removal. The multi-layer Transformer is used to realize the interaction between text features and generate a deep word vector representation with entity–type information, thus effectively avoiding ambiguity. Experimental results show that our model outperforms existing methods and performs well in ambiguous contexts relative to other models. We highlight the importance of entity–types in relation extraction.
Optimal Scheduling of Extreme Operating Conditions in Islanded Microgrid Based on Model Predictive Control
Authors: Su Shi , Ma Pengfei , Xie Qingyang , Liu Jie , Zhuan Xiangtao , Shang Lei
Published: January 2025

To address the optimal scheduling of islanded microgrids under extreme operating conditions, this paper proposes a demand response (DR) economic optimization scheduling strategy based on model predictive control (MPC). The strategy improves the utilization of photovoltaic (PV) and energy storage systems while ensuring stable power supply to critical loads through a dynamic load shedding approach based on load priority and power system constraints. By incorporating time-of-use electricity pricing and load importance assessment, an innovative demand response incentive policy is designed to optimize consumer behavior and reduce grid load pressure. Experimental results demonstrate that the DR-MPC-based method reduces operating costs and increases renewable energy utilization compared to traditional methods. This approach is broadly applicable to pre-emptive load shedding and energy storage optimization in islanded microgrids during emergencies and is expected to be extended to the optimal scheduling of microgrid clusters in the future.
Modeling of Respiratory Virus Transmission Using Single-Input- Multiple-Output Molecular Communication Techniques
Authors: Zhang Pengfei , Lu Pengfei , Wang Xiaofang , Liao Xuening
Published: January 2025

Respiratory diseases pose a significant threat to global public health, as exemplified by the COVID-19 pandemic. Molecular communication (MC), as a new method in communication systems, provides a framework for the modeling of diseases. Current studies, however, largely restrict MC models to transmission scenarios involving a single source and single receiver, leaving scenarios with multiple receivers insufficiently explored. This study investigates respiratory virus transmission through air, applying a single-input-multiple-output (SIMO) MC model to analyze the in vitro transmission process. In this context, a COVID-19-positive individual can transmit the virus to multiple recipients, modeled as a SIMO MC system where the affected person is the transmitter, susceptible individuals are receivers, and the intervening air serves as the communication channel. A theoretical model is developed to elucidate the virus transmission process, yielding foundational analytical expressions for the absorption probability. Numerical data validate the model and reveal factors influencing the cumulative reception probability. The results indicate that both the distance and angle between the transmitter and receiver significantly impact the absorption probability, which decreases with increasing distance and angle. Optimal absorption occurs when the receiver is directly in front of the emitter. These findings introduce a new perspective on viral transmission mechanisms and provide a scientific basis for future prevention and control measures.
An Innovative Real-Time Recursive Framework for Techno-Economical Self-Healing in Large Power Microgrids Against Cyber–Physical Attacks Using Large Change Sensitivity Analysis
Authors: Jahromi Mehdi Zareian , Yaghoubi Elnaz , Yaghoubi Elaheh , Maghami Mohammad Reza , Chamorro Harold R.
Published: January 2025

In the past, providing an online and real-time response to cyber–physical attacks in large-scale power microgrids was considered a fundamental challenge by operators and managers of power distribution networks. To address this issue, an innovative framework is proposed in this paper, enabling real-time responsiveness to cyberattacks while focusing on the techno-economic energy management of large-scale power microgrids. This framework leverages the large change sensitivity (LCS) method to receive immediate updates to the system’s optimal state under disturbances, eliminating the need for the full recalculation of power flow equations. This significantly reduces computational complexity and enhances real-time adaptability compared to traditional approaches. Additionally, this framework optimizes operational points, including resource generation and network reconfiguration, by simultaneously considering technical, economic, and reliability parameters—a comprehensive integration often overlooked in recent studies. Performance evaluation on large-scale systems, such as IEEE 33-bus, 69-bus, and 118-bus networks, demonstrates that the proposed method achieves optimization in less than 2 s, ensuring superior computational efficiency, scalability, and resilience. The results highlight significant improvements over state-of-the-art methods, establishing the proposed framework as a robust solution for real-time, cost-effective, and resilient energy management in large-scale power microgrids under cyber–physical disturbances.
Magnetic Field Distribution and Energy Losses in a Permanent Magnet Linear Synchronous Motor Under Stick-Slip Friction
Authors: Olejnik Paweł , Desta Yared D. , Mydłowski Marcin
Published: January 2025

This study investigates the modeling and dynamic analysis of three coupled electromechanical systems, emphasizing interactions between a magnetic linear drive and frictional contact with flat springs. The experimental setup includes a table driven by a three-phase permanent magnet linear synchronous motor (PMLSM) using an LMCA4 inductor, LMCAS3 magnetic track, and Xenus XTL controller. Mechanical phenomena such as stick-slip friction and impulsive loads are observed, particularly due to the rapid buckling of flat springs. These springs transition between sliding friction and fixation, impacting the motor’s operation during reciprocating velocity trajectories and generating acoustic emissions. Numerical simulations using COMSOL Multiphysics evaluate the magnetic field and system geometry in two- and three-dimensional spaces. Key findings include mechanical stick-slip vibrations, numerical modeling of the linear drive, and comparative analysis of experimental and simulated inductor current variations. Additionally, energy loss mechanisms under irregular loading conditions are assessed. The results highlight the coupling between friction-induced current changes and magnetic field variations, elucidating their impact on motor efficiency, vibration propagation, and acoustic emissions. The study provides insights into optimizing the design and reliability of coreless linear motors for precision applications under discontinuous loading.
Enhanced Hydrothermal Depolymerization with Fe/Ni Loaded C Catalysts for Improving Anaerobic Digestion Performance of Corn Stover
Authors: Wang Xitong , Zhu Chenyang , Yuan Hairong , Li Xiujin
Published: January 2025

This research investigated the effects of hydrothermal depolymerization with Fe/Ni loaded C catalysts on the anaerobic digestion (AD) performance of corn stover (CS). CS was depolymerized at 140 °C for 20 min with Fe/C or Ni/C catalysts, and then anaerobically digested. The results showed that the biomethane yield with Fe/C-600 increased by 36.6% compared to that of the control. This increase could be attributed to effective CS depolymerization with catalysts (DC), indicated by modified structures of solid fraction and enriched available components of liquid fraction. SEM analyses showed that CS microphysical structure after DC was obviously disrupted, resulting in more accessibility of cellulose and hemicellulose. The crystallinity index (CrI) of depolymerized CS was significantly reduced from 32.5% to 23.5%, allowing for a more easily biodegradable non-crystalline area to be available for enzymes. Meanwhile, the DC group produced 4.7 times more reducing sugar (RS), and a 3.4 times increase in total volatile fatty acids (VFAs) as compared to the control. Furthermore, these enhancements in DC led to an increased relative abundance of cellulolytic bacteria (Hydrogenispora and Fermentimonas) and anaerobic methanogenic archaea (Methanosarcina) in following the AD process. This could explain the reason for the biomethane yield increase with DC from microbial perspectives. This study demonstrated that hydrothermal depolymerization with Fe/C or Ni/C could provide an effective approach for obtaining more biomethane from CS via AD.
Comprehensive Overview of the Effective Thermal Conductivity for Hydride Materials: Experimental and Modeling Approaches
Authors: Scarpati Gabriele , Puszkiel Julián A. , Warfsmann Jan , Karimi Fahim , Jannelli Elio , Pistidda Claudio , Klassen Thomas , Jepsen Julian
Published: January 2025

In metal hydride beds (MHBs), reaction heat transfer often limits the dynamic performance. Heat transfer within the MHB usually involves solid and gas phases. To account for both, an effective thermal conductivity (ETC) is defined. Measuring and predicting the ETC of metal hydride beds is of primary importance when designing hydride-based systems for high dynamics. This review paper presents an integral overview of the experimental and modeling approaches to characterize the ETC in MHBs. The most relevant methods for measuring the ETC of metal hydride beds are described, and the results and scopes are shown. A comprehensive description of the models applied to calculate the ETC of the MHBs under different conditions is developed. Moreover, the effects of operation parameters such as P, T, and composition on the ETC of the presented models are analyzed. Finally, a summary and conclusions about experimental techniques, a historical overview with a classification of the ETC models, a discussion about the needed parameters, and a comparison between ETC experimental and calculated results are provided.
Enhancing Thermal Performance Investigations of a Methane-Fueled Planar Micro-Combustor with a Counter-Flow Flame Configuration
Authors: Li Liaoliao , Sun Yuze , Huang Xinyu , Guo Lixian , Zhao Xinyu
Published: January 2025

To enhance the performance of combustors in micro thermophotovoltaic systems, this study employs numerical simulations to investigate a planar microscale combustor featuring a counter-flow flame configuration. The analysis begins with an evaluation of the effects of (1) equivalence ratio Φ and (2) inlet flow rate Vi on key thermal and combustion parameters, including the average temperature of the combustor main wall (T¯w), wall temperature non-uniformity (R¯Tw) and radiation efficiency (ηr). The findings indicate that increasing Φ causes these parameters to initially increase and subsequently decrease. Similarly, increasing the inlet flow rate leads to a monotonic decline in ηr, while the T¯w and R¯Tw exhibit a rise-then-fall trend. A comparative study between the proposed combustor and a conventional planar combustor reveals that, under identical inlet flow rate and equivalence ratio conditions, the use of the counterflow flame configuration can increase the T¯w while reducing the R¯Tw. The Nusselt number analysis shows that the counter-flow flame configuration micro-combustor achieves a larger area with positive Nusselt numbers and higher average Nusselt numbers, which highlights improved heat transfer from the fluid to the solid. Furthermore, the comparison of blow-off limits shows that the combustor with counter-flow flame configuration exhibits superior flame stability and a broader flammability range. Overall, this study provides a preliminary investigation into the use of counter-flow flame configurations in microscale combustors.
Enhancing Air Conditioning System Efficiency Through Load Prediction and Deep Reinforcement Learning: A Case Study of Ground Source Heat Pumps
Authors: Wang Zhitao , Qiu Yubin , Zhou Shiyu , Tian Yanfa , Zhu Xiangyuan , Liu Jiying , Lu Shengze
Published: January 2025

This study proposes a control method that integrates deep reinforcement learning with load forecasting, to enhance the energy efficiency of ground source heat pump systems. Eight machine learning models are first developed to predict future cooling loads, and the optimal one is then incorporated into deep reinforcement learning. Through interaction with the environment, the optimal control strategy is identified using a deep Q-network to optimize the supply water temperature from the ground source, allowing for energy savings. The obtained results show that the XGBoost model significantly outperforms other models in terms of prediction accuracy, reaching a coefficient of determination of 0.982, a mean absolute percentage error of 6.621%, and a coefficient of variation for the root mean square error of 10.612%. Moreover, the energy savings achieved through the load forecasting-based deep reinforcement learning control method are greater than those of traditional constant water temperature control methods by 10%. Additionally, without shortening the control interval, the energy savings are improved by 0.38% compared with deep reinforcement learning control methods that do not use predictive information. This approach requires only continuous interaction and learning between the agent and the environment, which makes it an effective alternative in scenarios where sensor and equipment data are not present. It provides a smart and adaptive optimization control solution for heating, ventilation, and air conditioning systems in buildings.
Geometry Optimisation of a Wave Energy Converter
Authors: Costa Susana , Ferreira Jorge , Martins Nelson
Published: January 2025

The geometry optimisation of a point-absorber wave energy converter, focusing on the increase in energy absorption derived from heave forces, was performed. The proposed procedure starts by developing an initial geometry, which is later evaluated in terms of hydrodynamics and optimised through an optimisation algorithm to tune the shape parameters that influence energy absorption, intending to obtain the optimal geometry. A deployment site on the Portuguese coast was defined to obtain information on the predominant waves to assess several sea states. NEMOH and WEC-Sim (both open-source software packages) were used to evaluate the interaction between the structure and the imposed wave conditions. The results extracted and analysed from this software included forces in the six degrees of freedom. Under extreme wave conditions, the highest increase in the relative capture width between the initial and final shapes was around 0.2, corresponding to an increase from 0.36 to 0.54, while under average wave conditions, the increase only reached a value of around 0.02, corresponding to an increase from 0.22 to 0.24, as calculated through the relative capture width values.
Research on Opening Reignition Characteristics and Suppression Measures of 750 kV AC Filter Circuit Breakers
Authors: Zhang Jianguo , Sha Pengcheng , Ma Feiyue , Niu Bo , Cai Xu , Ni Hui , Deng Junbo
Published: January 2025

The operation of converter valves in converter stations often results in high reactive power consumption and harmonic generation, necessitating measures to maintain reactive power balance and ensure power quality. To achieve this, the filter bank circuit breaker is frequently switched on and off during daily operation. In recent years, multiple incidents of circuit breaker breakdown during the opening process have been reported. In this study, power systems computer-aided design (PSCAD)/electromagnetic transients including DC (EMTDC) V5.0 electromagnetic transient simulation software is used to simulate and calculate the overvoltage and inrush current under different configurations of circuit breaker operating mechanism dispersion, opening phase angle, and operating speed. Additionally, the suppression effects of two measures are compared: “phase selection opening” and “phase selection opening combined with controlled opening speed” to mitigate overvoltage and inrush current. The results demonstrate that for BP11/13 filters, HP24/36 filters, and HP3 filters, the combined strategy of “phase-selective opening with controlled opening speed” is more effective in suppressing inrush current and overvoltage. However, for SC filters, the suppression effect of this combined strategy is not significant. Considering economic and practical factors, it is more reasonable to adopt the phase-selective opening measure for SC filters. These findings provide guidance for ensuring the safe operation of AC filter circuit breakers.
Fast Simulation of the Flow Field in a VAWT Wind Farm Using the Numerical Data Obtained by CFD Analysis for a Single Rotor
Authors: Hara Yutaka , Moral Md. Shameem , Ide Aoi , Jodai Yoshifumi
Published: January 2025

The effects of an increase in output power owing to the close arrangement of vertical-axis wind turbines (VAWTs) are well known. With the ultimate goal of determining the optimal layout of a wind farm (WF) for VAWTs, this study proposes a new method for quickly calculating the flow field and power output of a virtual WF consisting of two-dimensional (2-D) miniature VAWT rotors. This new method constructs a flow field in a WF by superposing 2-D velocity numerical data around an isolated single VAWT obtained through a computational fluid dynamics (CFD) analysis. In the calculation process, the VAWTs were gradually increased one by one from the upstream side, and a calculation subroutine, in which the virtual upstream wind speed at each VAWT position was recalculated with the effects of other VAWTs, was repeated three times for each arrangement with a temporal number of VAWTs. This method includes the effects of the velocity gradient, secondary flow, and wake shift as models of turbine-to-turbine interaction. To verify the accuracy of the method, the VAWT rotor power outputs predicted by the proposed method for several types of rotor pairs, four-rotor tandem, and parallel arrangements were compared with the results of previous CFD analyses. This method was applied to four virtual WFs consisting of 16 miniature VAWTs. It was found that a layout consisting of two linear arrays of eight closely spaced VAWTs with wide spacing between the arrays yielded a significantly higher output than the other three layouts. The high-performance layout had fewer rotors in the wakes of the other rotors, and the induced flow speeds generated by the closely spaced VAWTs probably mutually enhanced their output power.
Impact of Long-Term Changes in Ambient Erythema-Effective UV Radiation on the Personal Exposure of Indoor and Outdoor Workers—Case Study at Selected Sites in Europe
Authors: Laschewski Gudrun
Published: January 2025

Given the persistently high incidence of skin cancer, there is a need for prevention-focused information on the impact of long-term changes in ambient solar ultraviolet radiation (UVR) on human personal radiation exposure. The exposure categories of the UV Index linked to protection recommendations show long-term shifts in the frequency of occurrence with regional differences in direction and magnitude. The patterns of change for sites in the humid continental climate differ from those for sites in other climate zones such as the humid temperate or Mediterranean climate. The diversity of the individual exposures of indoor and outdoor workers can be described using probability models for personal erythema-effective UVR dose (UVD). For people who work indoors, the largest share of the total individual annual UVD is due to vacation, whereas for people who work outdoors, it is occupational exposure. The change in ambient UVDs at the residential locations is only partially reflected in the individual UVDs. For eight selected European sites between 38° and 60° northern latitude, the median of the individual annual total UVD (excluding travel) during the period 2009–2019 is 0.2 to 2.0% higher for indoor workers and 0.6 to 3.2% higher for outdoor workers compared to the period 1983–2008. Changes in the choice of an exemplary holiday destination offer both indoor and outdoor workers the potential to compensate for the observed long-term trend at their place of residence and work.
Effects of Stand Structural Characteristics, Diversity, and Stability on Carbon Storage Across Different Densities in Natural Forests: A Case Study in the Xiaolong Mountains, China
Authors: Ma Yingdong , Zhang Xiaowei , Jiang Rui , Jiang Mengduo , Ju Jinmao
Published: January 2025

The carbon storage in forest ecosystems is closely linked to biomass, and its dynamic changes are of significant importance for assessing forest structure and function, as well as their response to global climate change. Recently, the research on the influencing mechanism of forest carbon storage has been a hotpot in the field of forest ecology. However, it remains unclear on the relationships among stand structure, stand stability, and carbon storage. The issues needed to be answered are as follows: How are tree density, tree species diversity, stand structural characteristics, stand stability, and carbon storage correlated? Is there a direct or indirect effect between tree density, tree species diversity, stand structural characteristics, stand stability, and carbon storage? Do these factors have an impact on stand stability, and, subsequently, carbon storage? What is the crucial factor in the mechanism that influences carbon storage? Here, the natural Quercus mongolica forests in the Xiaolong Mountains were taken as the research object. Several methods, including Pearson’s correlation, the best-fitting SEM, and multiple regression, were used to examine the relationships among tree density, tree species diversity, stand structural characteristics, stand stability, and carbon storage. Our results show that there were correlations between tree density, tree species diversity, stand structural characteristics, stand stability, and carbon storage. Tree density not only directly affects stand stability but also indirectly influences it through the mediation of tree species diversity and stand structural characteristics. Meanwhile, tree density also indirectly influences carbon storage through the mediation of tree species diversity, stand structural characteristics, and stand stability. Crown volume exerts the greatest influence on stand stability, while carbon storage is mostly impacted by stand stability. Overall, the combination of tree density, tree species diversity, stand structural characteristics, and stand stability influences carbon storage (66.4%). Therefore, it is important to consider stand stability when assessing carbon sequestration potentials; furthermore, the importance of tree density, tree species composition, and stand structural characteristics should be emphasized. Our research provides a scientific basis for conservation and management decision-making in natural forests and offers novel insights as well as a scientific reference for future large-scale carbon storage investigations.
Species Diversity of the Family Arecaceae: What Are the Implications of Their Biogeographical Representation? An Analysis in Amazonas, Northeastern Peru
Authors: Miranda Freddy , Coronel-Chugden José-Walter , Veneros Jaris , García Ligia , Guadalupe Grobert A. , Arellanos Erick
Published: January 2025

The understanding of species distribution in Peru is limited, in part due to cartographic representations that traditionally use political rather than biogeographical boundaries. The objective of this study was to determine the distribution of Arecaceae species in the department of Amazonas by representing them in biogeographical regions. To this end, geographic information systems and global databases were used to map and analyze the species in four categories: Ecosystems Map, Ecoregions Map, Peru Climate Classification Map, and Protected Natural Areas Map. Subsequently, diversity metrics were estimated, revealing high diversity in Amazonas, with 22 genera and 90 species of Arecaceae representing 51.16% and 41.28% of the records in Peru, respectively. In addition, predominant genera and species were identified, and diversity was evaluated in biogeographic units. Of a total of 336,029 records, 45 genera were found, with Geonoma and Bactris being the most representative, and of the 218 species found in total, the records that stood out the most varied according to biogeographical regions. For each Biogeographic unit by category, different responses were obtained, for example, for Index Margalef, between 0.000 (low in Agricultural Area), 7.2489 (medium in Eastern Cordillera Real Montane Forests), and 13.2636 (high in Non-protected Areas). Similarly, for the Shannon–Wiener diversity index (H¯), where values were obtained between 0.000 (low in Jalca (Andean High Grasslands), (medium in Reserved Zonez) and 3.7054 (high in Non-protected Areas). The results suggest high under-recording, evidencing gaps in knowledge and information, as analyses based on detailed studies of diversity in specific biogeographic categories in these other families, as well as future research to determine, for example, genomes and Hill numbers, will be carried out. The conclusions highlight the high correlation between the diversity metrics analyzed, confirm the theoretical validity, and allow us to recommend species richness and the Margalef Index as useful and relevant metrics due to their applicability and ease of interpretation. This study offers key information for decision makers in policies for the conservation of Arecaceae diversity and motivates us to project research of this type in other families in Peru.