bluuebunny/crossref_metadata_2025 huggingface dataset:
More pieces in the puzzle about language learning through audiovisual
input
Authors: Muñoz Carmen , Miralpeix Imma
Published: September 2024

In this concluding chapter, we bring together findings
from the studies in this volume and place them within the context of prior
research on audiovisual input, particularly within the broader framework of
the SUBTiLL project. The findings are organized into three sections:
captioned viewing, learning outcomes across various language dimensions, and
individual differences. The first section addresses several concerns
regarding captions, including their appropriateness for use with primary
school children, a comparison with L1 subtitles, and caption enhancement.
The second section delves into the observed improvements in vocabulary
acquisition, content comprehension, grammar, pronunciation, and pragmatics.
The third section examines individual differences, specifically focusing on
vocabulary size, reading skills, language learning aptitude, and age.
Finally, we discuss implications and propose future research directions.
Judy Lieberman: Stay curious and excited about science
Authors: Cols Montserrat
Published: September 2024

Judy Lieberman is a professor of pediatrics and adjunct professor of genetics at Harvard Medical School and an endowed chair in cellular and molecular medicine. Her lab studies cytotoxic T lymphocytes (CTL), key cells in the immune defense against viral infection and cancer, as well as molecular pathways activated by the granzymes, and how RNA interference (RNAi) regulates cell differentiation in health and disease states. We spoke to Judy about advice for early career researchers, how she first become interested in cytotoxic T lymphocytes, and key people who have provided mentorship across her career.
Enigmatic factor of 4/3 in electromagnetic momentum of a moving spherical capacitor
Authors: Singal Ashok K
Published: September 2024

The electromagnetic energy–momentum of a moving charged spherical capacitor may be calculated by a 4-vector Lorentz transformation from the energy in the rest frame. However, energy–momentum of the moving system computed directly from electromagnetic fields yields extra terms; in particular a factor of 4/3 in momentum appears, similar to that encountered in the classical electron model, where this enigmatic factor has been a source of confusion for more than a century. There have been many attempts to eliminate this ‘unwanted’ factor, noteworthy among them is a modification in electromagnetic field energy–momentum definition that has entered even standard textbooks. Here it is shown that in a moving charged spherical capacitor, such a factor of 4/3 in the electromagnetic momentum arises naturally from electromagnetic forces in system or equivalently from terms in the Maxwell stress tensor; contributions that do not otherwise show up in 4-vector transformations. A similar factor of 4/3 in the momentum of a perfect fluid comprising a randomly moving ultra-relativistic gas molecules or an isotropic photon gas, filling an uncharged spherical capacitor in motion, appears owing to the contribution of pressure. Thus, genesis of the ‘enigmatic’ factor of 4/3 can be traced to pressure or stress whose presence in the system may even be of non-electromagnetic origin and where the proposed modifications in energy–momentum definition do not even come into picture, implying there is no justification in modifying the standard definition of electromagnetic energy–momentum.
The dissolution of metal carbonate precipitation under the external electric and magnetic fields: reactive force field molecular dynamics simulation
Authors: Shen Cong , Lin Li , Lan Mu , Sun Zhijun , Zhao Wan , Chen Xisan
Published: September 2024

The dissolution of metal carbonates holds a pivotal role in diverse industrial processes, environmental occurrences, and geological formations. Grasping the fundamental mechanisms underlying these processes is imperative for enhancing industrial applications and mitigating environmental impacts. Herein, we undertake a thorough investigation employing reactive forcefieldmolecular dynamics simulations to delve into the dissolution process of metal carbonates. These simulations afford profound insights into the mechanisms and kinetics governing the process across various conditions, encompassing temperature, acidity, and external electric and magnetic fields. Although temperature itself exerts a limited influence, the study reveals a synergistic enhancement of metal carbonate dissolution kinetics when temperature is combined with static electric and magnetic fields. Our revelations offer enlightening perspectives on the intricate interplay of factors shaping dissolution processes, laying the foundation for future inquiries in this domain.
Twisted hyperbolic van der Waals crystals for chip-scale full Stokes mid-infrared polarization detection
Authors: Sahoo Nihar Ranjan , Prasath S S Jatin , Kumar Brijesh , Kumar Anshuman
Published: September 2024

Investigating the polarization properties of light in the mid-infrared (mid-IR) spectrum is crucial for molecular sensing, biomedical diagnostics, and IR imaging system technologies. Traditional methods, limited by bulky size and complicated fabrication process, utilize large rotating optics for full Stokes polarization detection, impeding miniaturization and accuracy. Naturally occurring hyperbolic van der Waals (vdW) material based devices can address these challenges due to their lithography-free fabrication, ease of integration with chip-scale platforms and room-temperature operation. This study designs a chip-integrated polarimeter by performing multi-objective optimization for efficient exploration of the design parameter space. The spatial division measurement scheme used incorporates six precisely designed linear and circular polarization filters, achieving high extinction ratios exceeding 30 dB and transmittance surpassing 50%, with fabrication tolerance of film thickness up to 100 nm. The proposed device represents a significant advancement in polarimetric detection, providing a compact, cost-effective solution and opens new avenues for on-chip mid-IR polarimetric detection in next-generation ultra-compact optical systems.
Rolling bearing fault diagnosis based on efficient time channel attention optimized deep multi-scale convolutional neural networks
Authors: Li Ou , Zhu Jing , Chen Minghui
Published: September 2024

In rolling bearing fault diagnosis, the collected vibration signal has nonlinear and non-Gaussian characteristics, which makes the signal feature extraction incomplete during the feature extraction process, leading to reduced fault diagnosis accuracy. This article proposes a model based on efficient time channel attention deep multi-scale convolutional neural network (EMCNN) to solve the above problems. This method designs a multi-scale hierarchical expansion strategy in the multi-scale CNN (MSCNN), which can effectively extract different ranges of information from the signal. In addition, the efficient time channel attention module is designed and embedded into the MSCNN to enhance the attention to the important features in both channel and time dimensions, and also to avoid the problem of feature redundancy. Adamax optimization algorithm is used as the optimizer, which realizes the automatic adjustment and optimization of the learning rate and greatly improves the model training efficiency and performance performance. The effectiveness of the method was verified using the datasets from Case Western Reserve University and Xi’an Jiaotong University. By comparing with other diagnostic models, it was verified that the method had a high diagnostic rate and good generalization performance under nonlinear and non-Gaussian complex characteristics.
Semi-supervised sparse feature optimization transfer learning for fault diagnosis under cross-condition and imbalanced data
Authors: Zhou Ziyou
Published: September 2024

Fault diagnosis in intelligent manufacturing faces challenges from cross-condition variations and data imbalances, especially with rare faults. Existing methods typically address these issues separately, yet both often coexist in industrial settings. To tackle these dual challenges, this study proposes a semi-supervised sparse feature optimization transfer learning diagnostic method (SSFOD). This method introduces two strategies: (1) improved enhanced sparse filtering to optimize feature sparsity and improve detection sensitivity for minority class faults, and (2) adaptive resampling maximum mean discrepancy to dynamically adjust data distributions, enhancing model adaptability and generalizability. Experimental results show that SSFOD achieves an average accuracy of 99.3%, significantly outperforming existing methods. This approach effectively addresses the combined challenges of cross-condition and imbalanced data fault diagnosis, advancing the field in complex industrial applications.
Realization and optimization of the gold-mesoporous silica based bimodal surface plasmon resonance sensor with digital Gaussian filter
Authors: Xu Xiaoxue , Xie Pengpeng , Ren Jiao , Wang Guiqiang
Published: September 2024

This work presented a novel biomdal surface plasmon resonance (BSPR) sensor with mesoporous silica film (MSF) and digital Gaussian filter. A modified Stöber solution growth approach was applied to prepare MSF film on the gold film. The conventional SPR sensor was coupled with a digital Gaussian filter to realize the BSPR sensor. After that, the Gaussian parameters were modified and the BSPR angular spectrum was obtained for further sensing experiments. Porosity and thickness of the MSF film were measured and calculated by means of a combination of simulation and measurement. The simulation results indicate that the refractive index (RI) sensitivity of the BSPR sensor could reach 75.11 deg/RIU which is 66.91% higher than the 45 deg/RIU of the conventional gold-MSF SPR sensor. Based on the experiments, the RI resolution of BSPR sensor was improved by 37.1% to 6.61 × 10−6 RIU, the limit of detection (LOD) for glucose was raised from 320 mg l−1 to 131 mg l−1, and the LOD for CTAB molecule was raised from 124.98 nM to 63.78 nM when compared to the gold-MSF SPR sensor.
An improved morphological filtering and feature enhancement method for rolling bearing fault diagnosis
Authors: Ren Xueping , Guo Liangjian , Liu Tongtong , Zhang Chao , Pang Zhen
Published: September 2024

The defects-induced periodic pulse is one of the important indices for the characterization of bearing failure. To solve the problem that the weak impact features caused by the early fault of the rolling bearing are easily to be interfered with by noise and strong background signal and are difficult to extract, an improved morphological filtering method combined with the Teager energy operator (TEO) is proposed to extract weak shock features. Firstly, according to the correlation between the periodic pulse induced by defects and the Morlet wavelet, the Morlet wavelet is used as the model to construct the structural elements. Then, capturing the Pearson correlation coefficient of the structural elements and the original signal and the signal is filtered by the variable scale morphological filter after threshold screening. Finally, the TEO is used as the post-enhancement link to suppress the noise in the signal after morphological processing and further highlight the fault characteristics. Simulation signals, experimental signals, and field signals verify the effectiveness and robustness of the proposed method.
Breakdown modes of capacitively coupled plasma: II. Non-self-sustained discharges
Authors: Wu Hao , An Ran , Jiang Can , Zhong Dong , Jiang Wei , Zhang Ya
Published: September 2024

This paper constitutes the second part of a two-part series investigating the breakdown modes of capacitively coupled plasma across varying pressures, employing an implicit particle-in-cell/Monte Carlo collision model. This segment focuses on non-self-sustained modes, namely normal failure discharge (NFD), bias failure discharge (BFD), and runaway failure discharge (RFD). NFD results from a failed electron avalanche, BFD stems from the charging effect of the blocking capacitor, and RFD arises from a decrease in electron emission rate during sheath formation. The effects of background pressure and voltage on these failure discharges are examined and analyzed. The RFD, which leads to periodic electron avalanches, is discussed in detail. Studying these non-self-sustained cases facilitates understanding the reasons for failure discharge in extremely low-pressure environments and determining the parameter limits of self-sustained discharge, crucial for preventing plasma cracks, enhancing equipment product yield, and ensuring equipment safety, thereby mitigating industrial losses.
Decoherence of high-dimensional orbital angular momentum entanglement in anisotropic turbulence
Authors: Yan Xiang , Zhang Peng-Fei , Fan Cheng-Yu , Zhao Heng , Zhang Jing-Hui , Wang Bo-Yun , Wang Jun-Yan
Published: September 2024

The decoherence of high-dimensional orbital angular momentum (OAM) entanglement in the weak scintillation regime has been investigated. In this study, we simulate atmospheric turbulence by utilizing a multiple-phase screen imprinted with anisotropic non-Kolmogorov turbulence. The entanglement negativity and fidelity are introduced to quantify the entanglement of a high-dimensional OAM state. The numerical evaluation results indicate that entanglement negativity and fidelity last longer for a high-dimensional OAM state when the azimuthal mode has a lower value. Additionally, the evolution of higher-dimensional OAM entanglement is significantly influenced by OAM beam parameters and turbulence parameters. Compared to isotropic atmospheric turbulence, anisotropic turbulence has a lesser influence on high-dimensional OAM entanglement.
Innovative research on hybrid absorption refrigeration system with complementary solar energy and waste heat
Authors: Qu Zhuangzhuang
Published: September 2024

With the increasingly prominent global energy crisis and environmental problems, the search for efficient and environmentally friendly energy utilization has become a hot spot of current research. The large-scale application of solar energy and waste heat in absorption refrigeration technology is one of the important technical means to achieve the goal of “double carbon”, while the traditional absorption refrigeration system has disadvantages such as discontinuity and instability. To improve the stability of the absorption refrigeration system and extend the operation time of the absorption refrigeration unit, this paper explores the application of the hybrid absorption recycling refrigeration system to the energy system with complementary solar energy and waste heat. In the future, the system design will be further optimized, the performance and economy of the system will be improved, and the wide application of the technology in industrial production and daily life will be promoted.
Research characteristics of aquifer energy storage system based on sandbox experiment
Authors: Huang Lihan , Li Wenxin , Chen Zhenqian
Published: September 2024

Based on the principle of thermal similarity, a complete sandbox experimental platform is established, and a corresponding three-dimensional unsteady-state heat transfer model is constructed. The study investigates the influence of boundary size on the energy storage characteristics of aquifer experiments. The wall boundary of the existing experimental platform has an impact on the experimental results. There exists a time in the experiment with the greatest discrepancy from the actual model, which is approximately 35 % of the cycle time. A new well-pipe structure with a unilateral water intake is proposed. The aquifer energy storage system that employs this structure exhibits smaller variations in extraction temperature during operation, resulting in an increase of energy storage capacity by 13.9% and an improvement of energy storage efficiency by 19.6%.
Sun tracking control technology of solar furnace
Authors: Shi Congcong , Zang Chuncheng , Sun Feihu , Wang Zhifeng
Published: September 2024

In this study, to improve the sun-tracking accuracy of the solar furnace, a sun-tracking control system is developed, and the control strategy of combining open-loop and photoelectric semi-closed-loop control is adopted for the system. A solar furnace prototype is built to verify the performance of the control system. Through sun tracking experiments, the tracking accuracy of the solar furnace is analyzed under open-loop and photoelectric semi-closed-loop control. The experimental results show that the tracking error of open-loop control is less than 12.2 mrad. The photoelectric semi-closed-loop control can effectively improve the sun tracking accuracy of the solar furnace with a tracking error of less than 3.5 mrad.
Power allocation strategy for electrolytic cell cluster system for high proportion photovoltaic consumption
Authors: Zhang Shuyan , Agu Damu , Jiang Cheng
Published: September 2024

Limited by the capacity of a single electrolytic cell, the large-scale hydrogen production system must be operated by a combination of multiple electrolytic cells to form an electrolytic cell cluster. Meanwhile, photovoltaic power generation has real-time changes of uncertainty. Allocating the operating power safely, efficiently, and reasonably to each electrolytic cell in the cluster is a crucial issue for large-scale hydrogen production systems. Therefore, this paper proposes a power allocation strategy for the electrolytic cell cluster system. Firstly, the operation characteristics of a single electrolytic cell and cluster are analyzed. Then, considering constraints such as power balance, electrolytic cell power limitations, and grid restrictions, a power allocation model for electrolytic cell clusters is established to maximize photovoltaic consumption. Based on this, a power coordination allocation strategy for the single electrolytic cell is provided. Finally, the effectiveness of the proposed strategy is verified through an example analysis.
Research on photovoltaic and energy storage systems in substation based on virtual DC machine control
Authors: Zou Bin , Liang Jianan , He Dehui
Published: September 2024

To address the issues of insufficient inertia and damping support caused by massive power electronic equipment devices connected to DC substations, and the large fluctuation or instability of the 220 V DC bus voltage caused by the variation of power on the load side, an enhanced inertial control strategy based on VDCM (EI-VDCM) for DC substation is proposed. Firstly, the structure of the PV and energy storage DC substation is described. Secondly, the correspondingly mathematical model of the EI-VDCM control is derived. Then, the auxiliary voltage regulation power link is introduced into the control system to suppress the fluctuation of DC bus voltage caused by power change. Finally, the simulation model is built to verify the control strategy, and the actual waveform results show that the EI-VDVM control strategy can improve the transient stability of the DC bus voltage.
Estimation of lithium battery state of charge using PSO-AEKF algorithm
Authors: Zhu Tianye , Shi Zhihan , Zhang Tianyang , Zhang Guangming
Published: September 2024

For the construction of a second-order model, it is necessary to accurately identify five key parameters: R
0, Rp
, Cp
, Rp
, and Rd
. Traditional offline parameter identification methods rely solely on fitting the curve during the quiescent period after discharge to determine these parameters. This paper employs the Particle Swarm Optimization (PSO) algorithm combined with a second-order RC discrete model to fit the operating curve, thereby enhancing the model’s accuracy. In subsequent estimations, an adaptive Kalman filter is introduced to compare these two sets of parameters.
Research on torque ripple suppression of in-wheel fractional slot permanent magnet synchronous motors based on auxiliary slots
Authors: Yang Zhimeng , Tian Shaopeng
Published: September 2024

To address the issue of significant torque ripple in in-wheel fractional slot motors, a method involving the introduction of stator auxiliary slots is employed to weaken cogging torque and reduce vibration and noise generated during motor operation. Through analysis of cogging torque, the impact of the size, spacing, and quantity of auxiliary slots on torque performance is investigated. When four appropriately parameterized auxiliary slots are introduced, the cogging torque decreases from 7.81 Nm to 2.38 Nm, a reduction of 69.53%. Underrated conditions, the output torque increases from 131.84 Nm to 137.32 Nm, and the ripple of torque decreases from 14.87% to 6.97%. Thus, the motor’s torque performance is significantly improved.
PAS-YOLO: improved YOLOv8 integrating parameter-free attention and channel shuffle for object detection of power grid equipment
Authors: Xu Meng , Li Baofeng , Su Junchi , Qin Yu , Li Qiangwei , Lu Jiansheng , Shi Zhiheng , Gao Xin
Published: September 2024

Using an object detection network to identify power grid equipment in low-voltage stations automatically can effectively improve the accuracy and efficiency of information inspection, which is of great significance to the safe and stable operation of a power system. The current advanced object detection model YOLOv8 has high accuracy and efficiency in detection tasks. However, it still suffers from leakage and misclassification in complex scenarios, and there are higher lightweighting requirements in the face of real-time detection processes. This paper proposes a lightweight power grid equipment object detection model, PAS-YOLO. It uses a parameter-free attention module to extract features through convolution. A ShuffleNet Block, which consists of multiple channel shuffle modules, is introduced to reduce the convolution kernel parameters and improve computational efficiency. Extensive experiments on several benchmark and power grid equipment datasets demonstrate that our method outperforms the original YOLOv8 on multiple object detection metrics.
Traversal-based automatic EMT modeling approach for new type of power systems with massive power electronics
Authors: Xu Yizheng , Liu Min , Qiao Xiaomin , Wang Feng , Wang Xiangxu , Mu Qing
Published: September 2024

The increasing penetration of renewable energy devices and HVDCs/VSC-HVDCs has induced expansion of the grid as well as a large number of power electronics, which could extend the modeling process, induce more mistakes during modeling, increase the computing tasks, and slow down the simulation process. To address the issues, this paper proposes a traversal-based automatic EMT modeling approach for large grids with high penetration of power electronic devices, where traversal process and depth-first search are used. The approach is written in a C++ program and implemented with models of both benchmark case studies and actual UHVDC projects. The simulation result shows that the proposed approach can guarantee the error of the model within 3%, improve the modeling efficiency by four times, and enhance the simulation efficiency by almost twice that in the manual modeling process.
Simulation of electric potential distribution and assessment of personal safety risks near grounding devices of urban high-voltage transmission line towers
Authors: Hu Yaorong , Hu Wei , Feng Yuwei , Wang Di , Zou Jiang
Published: September 2024

This study investigates the electric potential distribution near transmission line towers, focusing on the impact of contact voltage and step voltage on power system safety and personal safety. It establishes a model correlating contact voltage and step voltage with total human body current by analyzing key parameters of human electrocution accidents. Using finite element computational models, it accurately simulates the potential distribution of common tower grounding devices under fault currents, revealing distinct characteristics of potential distribution among different device configurations. The simulation reveals complexities in the potential distribution of square grounding devices with horizontal rays, proposing innovative suggestions to optimize grounding systems and reduce potential differences. Additionally, it analyzes current flowing through grounding devices under various fault conditions, highlighting potential risks of personal electrocution. Finally, the study proposes optimization schemes for electric potential distribution near transmission line towers’ grounding systems, offering crucial insights for power system safety and engineering design.
Simulation research on generator leading phase test and main transformer tap selection
Authors: Jiang Dawei , Yu Longbin , Niu Li , Liu Chang , Zhou Yuxiao , Guo Tie , Gao Yue
Published: September 2024

In a hydropower plant, the generator terminal voltage was found to be too low during a leading phase test, preventing the generator from achieving the expected leading phase capacity. An analysis of this issue led to a proposed solution involving adjustments to the main transformer tap changer. To validate this approach, a generator leading phase test simulation system was employed. This system simulated both the lagging power factor operation and leading phase test data for various tap settings of the main transformer. The simulated data were then compared with actual data from a second leading phase test conducted after adjusting the transformer taps. This case study also introduces the application method of the generator leading phase test simulation system and underscores its critical role in conducting effective leading phase tests.
Error prediction of VMD-GRU current transformer based on bayesian optimization
Authors: Chen Xu , Zhang Chao , Zhang Haomiao , Cheng Zhiqiang , Xu Yinzhe , Yan Yu , Ou Long , Su Yingchun
Published: September 2024

With the aim of accurately predicting the measurement error of the current transformer, a Bayesian optimization-based error prediction method combining variational mode decomposition (VMD) and gated recurrent unit (GRU) was proposed. Firstly, the secondary current signal of the CT is decomposed by VMD, and the arrangement entropy of each sequence signal is calculated, so as to determine the best decomposed mode number. Then, the decomposed modal components are utilized as inputs to the recognition model. Finally, a GRU model serves as the prediction model for each component, forecasting individual components, after which the predicted results of these components are reconstructed to yield the ultimate prediction outcome.
Improved stability analysis of delayed frequency regulation systems for a cyber-physical microgrid
Authors: Xu Haotian , Ba Lei
Published: September 2024

In a microgrid, the types of power supply and users are diverse. To use the frequency support potential of the multi-type of power supply units in the microgrid, these units can be connected to form a frequency control system with the help of an open network. However, a signal transmission delay exists in the network, which may affect the control performance and further lead to instability. Considering the effects of the delay type, this paper analyzed the micro-grid system stability during frequency support, and the allowable time delay range is estimated when the frequency control system can work normally. Firstly, based on the frequency support principle in a micro-grid, the mechanism equations of each part involved in the micro-grid frequency support are presented, and the time delay of the control loop is considered so that the state-space model of the frequency support control system is built. Secondly, based on Lyapunov stability theory, a time delay-related discriminant approach is proposed for the control system to maintain stability using increasing range function, integral inequality of auxiliary function, and matrix injection. Finally, the delay tolerance in different scenarios of a specific micro-grid system is estimated by the proposed approach. The result shows that the proposed approach is less conservative than the existing methods. Meanwhile, the relationship between controller gain and delay tolerance is given, which can be used as a reference in the controller design.
Automatic feeder planning method of distribution network in mountainous areas considering access to distributed energy
Authors: Zhang Yan , Zheng Fei , Zhang Yu , Xu Xiaoshuang
Published: September 2024

This paper takes the distribution network in mountainous areas as the research object, based on the construction mode of feeder automation and the influence of distributed energy access on feeder automation, studies the influence of distributed energy access on the distribution system in mountainous areas, and puts forward a feeder automation planning method for 10 kV distribution network in mountainous areas considering DG access. On this basis, this project aims to achieve the lowest annual total cost of automatic configuration and establishes a feeder automation planning model. Finally, taking the mountainous distribution network as the research object, through the preferred arrangement method and a number of feeder automation, the recommended form of feeder automation plan for the mountainous distribution network is finally formed to provide a reference for the design of feeder automation in the mountainous distribution network. On the premise of meeting the reliability index, an example shows that this method has a better economic effect.
Regional analysis and optimization control of static power stable operation of grid-connected converter under weak grid
Authors: Liu Yibo , Liu Guiying , Li Hong , Chen Lingbin , Long Kun , Li Yangbin
Published: September 2024

As photovoltaic energy generation systems are connected to the grid, the strength of the grid will decrease, which will limit the power output capacity of the grid-connected converter (GCC). To solve the above problems, a reactive power compensation optimization control strategy of a grid-connected converter connected to a weak grid is proposed. Firstly, the mechanism of a weak network environment affecting stable output active power of grid-connected converter is revealed. Then, the critical short-circuit ratio of static power stability under the unit power factor is obtained by taking the grid-connected converter output current amplitude and the allowable voltage range of the point of common coupling as constraints. Next, the critical short-circuit ratio of static power stability is obtained when only grid-connected converter capacity is considered and when an external reactive power compensation device is attached. Finally, MATLAB/Simulink is used to verify the correctness and validity of the theoretical analysis.
Analysis of the PV/T system for electricity and hot water production
Authors: Wu Chenxi , Zhu Qunzhi
Published: September 2024

This paper designs a PV/T system based on TRNSYS software that can be used for power and hot water production. The annual performance analysis of the system is conducted on the power and hot water production using Shanghai’s typical meteorological data. The annual PV/T electricity generation and hot water production are 1794.87 kW h and 195.57 m3, respectively. The effects of photovoltaic coverage ratio and tank volume on the performance of the PV/T system are analyzed. The photovoltaic coverage ratio significantly affects the electricity generation of the PV/T system but slightly affects the total hot water production. The volume of the tank has almost no effect on the electricity generation of the PV/T system but enhances hot water production.
Optimization of cooling operation strategy for server cabinets based on air-cooled chiller
Authors: Shi Yuanyuan , He Wei , Zhang Yonglei , Guo Tao
Published: September 2024

Currently, liquid cooling is an important development direction for data centers. The existing research is mainly on establishing cooling systems with different cooling sources or optimizing heat dissipation on the cabinet side but does not take both into account. Therefore, this paper focuses on finned water-cooled heat sinks and air-cooled chillers and analyses their comprehensive thermal management. Based on the analysis of the cooling system with minimum energy consumption, the optimum operating parameters were derived. The hourly energy power decreased by 13% with the chilled water outlet temperature of the air-cooled chiller from 6°C to 14°C. Finally, annual operating energy power according to the different control strategies is analyzed, and it is found that when the ambient temperature regulation interval is 5°C, the cooling system with an air-cooled chiller as the cooling source is the most energy-efficient and economical. While the chilled water outlet temperature of the air-cooled chiller is raised from 6°C to 16°C, energy power is reduced by 17.1%, and the PUE is reduced by 3.4%.
Different wind speeds affect gangue thermoelectric conversion efficiency
Authors: Huang Wenjuan , Peng Hong
Published: September 2024

The wind speed of the external environment has a significant impact on the spontaneous combustion of coal Gangue Mountain, and there are different impacts on the hot spot conversion of waste heat through heat pipes and temperature difference power generation devices. To study the change rule, this paper first from the analysis of the test area environment, heat pipe cooling analysis, temperature difference power generation device for thermoelectric conversion analysis, and different wind speed cases on the thermoelectric conversion efficiency of the impact of research. Comsol software is utilized to map the changes in temperature at different wind speeds, thus affecting the thermoelectric conversion. Through the study, it is shown that the thermoelectric conversion efficiency presents a trend of change with the wind speed of the first increase and then decrease.
Research on waste heat utilization potential of data centers for agricultural greenhouse heating
Authors: Du Zhibin , Li Qifen , Yang Yongwen , Zhang Liting
Published: September 2024

The explosive growth of the data center computing business has caused the problem that the operation energy consumption is too high and the waste heat of equipment heat dissipation is discharged into the atmosphere without utilization. How to utilize data center waste heat economically and effectively has become the focus of research in recent years. At the same time, as a large agricultural country, China is promoting agricultural modernization, and the number of agricultural greenhouses is also increasing year by year. Ensuring that agricultural greenhouses can use more green, efficient, and cheaper heat sources in winter is also an urgent problem to be solved. In this paper, based on the characteristics of large, stable, temperature matching and combined with the winter demand for agricultural greenhouses, a scheme of using data center waste heat for agricultural greenhouses is proposed. Firstly, this paper defines the waste heat collection from the hot channel of the machine room and the backwater of the cooling unit, establishes the waste heat calculation model of the data center, and calculates the hourly heat generated by the equipment in the machine room and the hourly waste heat change of the water cooling unit according to the hourly change of the electrical load of the data center. At the same time, the heat generated in the machine room is collected in the hot channel and replaced by the heat pipe heat exchanger, and the residual heat of the hot channel is calculated in this part. Then, the heat load model of agricultural greenhouses is established to match the waste heat of data centers, and heat pump heating equipment is selected to heat agricultural greenhouses. Finally, the equipment is optimized according to the waste heat extracted from the hot channel.
Experimental study of heat transfer in double-loop plate pulsating heat pipe
Authors: Qiao Ni , Xiahou Guowei , Wang Ruiqi
Published: September 2024

To address the shortcomings of plate PHP, this paper proposes a novel PHP--double-loop plate PHP, which consists of two arched pulsating cold-end plates and one capillary hot-end plate constituting a loop, and experimental studies done on it reveal the following observations: the optimal working conditions of the double-loop plate PHP are 25% liquid filling rate, 90°tilt, edge placement, and the thermal resistance is just 0.014°C/W at 60W. Compared with the traditional plate PHP, its heat dissipation performance has been improved by 42.1%, and it has a better working ability under any tilt angle and heating mode. Therefore, the heat dissipation performance and application flexibility of double-loop plate PHP are better and more suitable for high heat flow density chips.
A novel mechanical design of a bolometric array for the CROSS double-beta decay experiment
Authors: Auguste D. , Barabash A.S. , Berest V. , Bergé L. , Calvo-Mozota J.M. , Carniti P. , Chapellier M. , Dafinei I. , Danevich F.A. , Dixon T. , Dumoulin L. , Ferri F. , Gallas A. , Giuliani A. , Gotti C. , Gras P. , Ianni A. , Imbert L. , Khalife H. , Kobychev V.V. , Konovalov S.I. , Loaiza P. , de Marcillac P. , Marnieros S. , Marrache-Kikuchi C.A. , Martinez M. , Nones C. , Olivieri E. , Ortiz de Solórzano A. , Peinaud Y. , Pessina G. , Poda D.V. , Rosier Ph. , Scarpaci J.A. , Tretyak V.I. , Umatov V.I. , Zarytskyy M.M. , Zolotarova A.
Published: September 2024

The CROSS experiment will search for neutrinoless
double-beta decay using a specific mechanical structure to hold
thermal detectors. The design of the structure was tuned to minimize
the background contribution, keeping an optimal detector
performance. A single module of the structure holds two
scintillating bolometers (with a crystal size of
45 × 45 × 45 mm and a Ge slab facing the crystal's
upper side) in the Cu frame, allowing for a modular construction of
a large-scale array. Two designs are released: the initial
Thick version contains around 15% of Cu over the crystal
mass (lithium molybdate, LMO), while this ratio is reduced to
∼ 6% in a finer (Slim) design. Both designs were tested
extensively at aboveground (IJCLab, France) and underground (LSC,
Spain) laboratories. In particular, at LSC we used a
pulse-tube-based CROSS facility to operate a 6-crystal array of LMOs
enriched/depleted in 100Mo. The tested LMOs show high
spectrometric performance in both designs; notably, the measured
energy resolution is 5–7 keV FWHM at 2615 keV γs, nearby
the Q-value of 100Mo (3034 keV). Due to the absence of a
reflective cavity around LMOs, a low scintillation signal is
detected by Ge bolometers: ∼ 0.3 keV (150 photons) for 1-MeV
γ(β) LMO-event. Despite that, an acceptable separation
between α and γ(β events is achieved with most
devices. The highest efficiency is reached with light detectors in
the Thick design thanks to a lower baseline noise width
(0.05–0.09 keV RMS) when compared to that obtained in the
Slim version (0.10–0.35 keV RMS). Given the pivotal role of
bolometric photodetectors for particle identification and random
coincidences rejection, we will use the structure here described
with upgraded light detectors, featuring thermal signal
amplification via the Neganov-Trofimov-Luke effect, as also
demonstrated in the present work.
Development of a bi-solvent liquid scintillator with slow light emission
Authors: Steiger Hans Th.J. , Stock Matthias Raphael , Böhles Manuel , Braun Sarah , Callaghan Edward J. , Dörflinger David , Fahrendholz Ulrike , Firsching Jonas , Fischer Elias , Kaptanoglu Tanner , Kayser Lennard , Lu Meishu , Oberauer Lothar , Orebi Gann Gabriel D. , Stangler Korbinian , Wurm Michael , Zundel Dorina
Published: September 2024

One of the most promising approaches for the next generation
of neutrino experiments is the realization of large hybrid
Cherenkov/scintillation detectors made possible by recent
innovations in photodetection technology and liquid scintillator
chemistry. The development of a potentially suitable future detector
liquid with particularly slow light emission is discussed in the
present publication. This cocktail is compared with respect to its
fundamental characteristics (scintillation efficiency, transparency,
and time profile of light emission) with liquid scintillators
currently used in large-scale neutrino detectors. In addition, the
optimization of the admixture of wavelength shifters for a
scintillator with particularly high light emission is
presented. Furthermore, the pulse-shape discrimination capabilities
of the novel medium was studied using a pulsed particle accelerator
driven neutron source. Beyond that, purification methods based on
column chromatography and fractional vacuum distillation for the
co-solvent DIN (Diisopropylnaphthalene) are discussed.
Propulsive efficiency of spatiotemporally asymmetric oscillating appendages at intermediate Reynolds numbers
Authors: Herrera-Amaya Adrian , Byron Margaret L
Published: September 2024

Many organisms use flexible appendages for locomotion, feeding, and other functional behaviors. The efficacy of these behaviors is determined in large part by the fluid dynamics of the appendage interacting with its environment. For oscillating appendages at low Reynolds numbers, viscosity dominates over inertia, and appendage motion must be spatially asymmetric to generate net flow. At high Reynolds numbers, viscous forces are negligible and appendage motion is often also temporally asymmetric, with a fast power stroke and a slow recovery stroke; such temporal asymmetry does not affect the produced flow at low Reynolds numbers. At intermediate Reynolds numbers, both viscous and inertial forces play non-trivial roles—correspondingly, both spatial and temporal asymmetry can strongly affect overall propulsion. Here we perform experiments on three robotic paddles with different material flexibilities and geometries, allowing us to explore the effects of motion asymmetry (both spatial and temporal) on force production. We show how a flexible paddle’s time-varying shape throughout the beat cycle can reorient the direction of the produced force, generating both thrust and lift. We also evaluate the propulsive performance of the paddle by introducing a new quantity, which we term ‘integrated efficiency’. This new definition of propulsive efficiency can be used to directly evaluate an appendage’s performance independently from full-body swimming dynamics. Use of the integrated efficiency allows for accurate performance assessment, generalization, and comparison of oscillating appendages in both robotic devices and behaving organisms. Finally, we show that a curved flexible paddle generates thrust more efficiently than a straight paddle, and produces spatially asymmetric motion—thereby improving performance—without the need for complex actuation and controls, opening new avenues for bioinspired technology development.
Exhaled breath condensate (EBC) in respiratory diseases: recent advances and future perspectives in the age of omic sciences
Authors: Maniscalco Mauro , Candia Claudio , Fuschillo Salvatore , Ambrosino Pasquale , Paris Debora , Motta Andrea
Published: September 2024

Exhaled breath condensate (EBC) is used as a promising noninvasive diagnostic tool in the field of respiratory medicine. EBC is achieved by cooling exhaled air, which contains aerosolized particles and volatile compounds present in the breath. This method provides useful information on the biochemical and inflammatory state of the airways. In respiratory diseases such as asthma, chronic obstructive pulmonary disease and cystic fibrosis, EBC analysis can reveal elevated levels of biomarkers such as hydrogen peroxide, nitric oxide and various cytokines, which correlate with oxidative stress and inflammation. Furthermore, the presence of certain volatile organic compounds in EBC has been linked to specific respiratory conditions, potentially serving as disease-specific fingerprints. The noninvasive nature of EBC sampling makes it particularly useful for repeated measures and for use in vulnerable populations, including children and the elderly. Despite its potential, the standardization of collection methods, analytical techniques and interpretation of results currently limits its use in clinical practice. Nonetheless, EBC holds significant promise for improving the diagnosis, monitoring and therapy of respiratory diseases. In this tutorial we will present the latest advances in EBC research in airway diseases and future prospects for clinical applications of EBC analysis, including the application of the Omic sciences for its analysis.
Analysis of air humidity distribution caused by fabric air duct arrangement for human comforts by computational fluid dynamic
Authors: Khaothong Kunthakorn , Boonpaijit Supakij , Manatura Kanit , Jaojaruek Kitipong , Chaiworapuek Weerachai
Published: September 2024

This research investigates the effects of the physical properties of air ducts and air supply conditions on 60% RH humidity distribution and human comfort in air-conditioned research laboratories. The study uses computational fluid dynamics in combination with the Taguchi experimental design to analyse the data. For the supply air, 25 fabric air ducts were used. The simulation results show the isometric flow trajectories of the relative humidity distribution in the room and the contours of the ankle and neck planes of a male Thai subject with a humidity distribution between 50% and 55% RH. By focusing on the ankle and neck plane, researchers understand how moisture control can be optimized to enhance comfort and performance.
Pleijel nodal domain theorem in non-smooth setting
Authors: De Ponti Nicolò , Farinelli Sara , Violo Ivan Yuri
Published: September 2024

We prove the Pleijel theorem in non-collapsed RCD spaces, providing an asymptotic upper bound on the number of nodal domains of Laplacian eigenfunctions. As a consequence, we obtain that the Courant nodal domain theorem holds except at most for a finite number of eigenvalues. More in general, we show that the same result is valid for Neumann (resp. Dirichlet) eigenfunctions on uniform domains (resp. bounded open sets). This is new even in the Euclidean space, where the Pleijel theorem in the Neumann case was open under low boundary-regularity.
Serge Rachmaninoff (1873–1943)
Authors: Wilson Miranda
Published: September 2024

The new and diverse styles of early to mid-twentieth century composition did not prevent some of the major composers of the era from continuing to write in “traditional” genres such as the sonata. Three twentieth-century sonatas for cello and piano, one each by Rachmaninoff, Barber, and Prokofiev, combine multi-movement sonata structures inherited from the great Romantic sonatas with more modern ways to use melody and harmony. These include heightened chromaticism, frequent dissonance, and octatonic language. Each of these sonatas also retains a sense of intense lyricism in the cello writing, an aspect that creates the impression of looking back to Romanticism.
Benjamin Britten (1913–1976)
Authors: Wilson Miranda
Published: September 2024

The sheer abundance of cello compositions from the second half of the twentieth century and beyond makes it difficult to trace the threads of influence between them. The featured compositions by Britten, Perkinson, Sheng, and Sollima, four highly contrasting works, share one commonality: a postmodern concept of musical language that integrates style features from multiple musical traditions and eras. Three—Britten’s suites, Sollima’s Alone, and Perkinson’s Lamentations—allude both explicitly and obliquely to neo-Baroque melodies, harmonies, and forms within otherwise “modern” settings. Two, Perkinson’s Lamentations and Sheng’s Seven Tunes Heard in China, fuse melodic material from the religious and folk music traditions of their respective cultures with the notation and instrumentation of contemporary classical music. Such new sound-worlds demand ever-increasing extensions to the technique. This “new virtuosity” requires cellists to master and assimilate different ways of creating sound in the service of ever more diverse repertoire.