bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Fault Current and Different Oscillating Magnetic Fields on Electromagnetic–Thermal Characteristics of the REBCO Coil
Authors: Chen Wei , Jin Rong , Wang Shuxin , Ye Yunyang , Chi Fei , Xu Minghai , Liu Liyuan , Qian Yece , Zhang Yufeng , Shen Boyang
Published: November 2022

When the high-temperature superconducting (HTS) REBCO (rare-earth barium copper oxide) coil is applied in a power system, a large amount of heat may be generated due to the short-circuiting of the system, resulting in the thermal instability of the coil. Moreover, under complex working conditions, the oscillating external magnetic field will further aggravate the coil quench. In this paper, the electromagnetic–thermal coupling model is used to analyze the loss, current distribution and temperature distribution of the REBCO coil under short-circuit fault conditions and oscillating external magnetic fields. In order to get closer to the actual situation, the modeling of the superconducting tape adopts the real tape structure, and the resistivity of the superconductor is described by the modified E-J relationship. Four cases are considered for the oscillating external magnetic field, i.e., sine, triangle, sawtooth and square cases. This model has certain significance as a reference for understanding the thermal stability of coils in extreme cases.
Structure–Superstructure Inter-Relations in Ca2SiO4 Belite Phase
Authors: Psycharis Vassilis , Chatzigeorgiou Manolis , Koumpouri Dimitra , Beazi-Katsioti Margarita , Katsiotis Marios
Published: November 2022

Belite, the second most abundant mineralogical phase in Portland cement, presents five polymorphs which are formed at different temperatures. The increased interest in belite cement-based products is due to the lower environmental impact associated with the lower energy consumption. The importance of belite polymorphs formed at higher temperatures for cement industry applications is high, because they present better hydraulic properties. Thus, any study that helps to explore the structure relations of all belite polymorphs is of interest for both scientific and practical points of view. In the present work, a systematic structure–superstructure relation study is presented for all polymorphs, and it is based on the work of O’Keefe and Hyde (1985). In this pioneering work, generally, the structures of oxides are considered as having common characteristics with prototype structures of alloys. The basic result of the present work is the fact that all the polymorphs adopt a common architecture which is based on capped trigonal prisms of Ca cations, which host the Si one, and the oxygen anions occupy interstitial sites, i.e., an architecture in conformity with the model which considers the oxide structures as stuffed alloys. This result supports the displacive character of the transformation structural mechanism that links the five polymorphs based on the cation sites in their structures. However, based on the sites of oxygen anions, it could be considered as of diffusion character. The study of belite polymorphs is also of interest to products obtained by doping dicalcium silicate compounds, which present interesting luminescent properties.
Effects of Physical and Chemical Pressure on Charge Density Wave Transitions in LaAg1−xAuxSb2 Single Crystals
Authors: Xiang Li , Ryan Dominic H. , Canfield Paul C. , Bud’ko Sergey L.
Published: November 2022

The structural characterization and electrical transport measurements at ambient and applied pressures of the compounds of the LaAg1−xAuxSb2 family are presented. Up to two charge density wave (CDW) transitions could be detected upon cooling from room temperature and an equivalence of the effects of chemical and physical pressure on the CDW ordering temperatures was observed with the unit cell volume being a salient structural parameter. As such LaAg1−xAuxSb2 is a rare example of a non-cubic system that exhibits good agreement between the effects of applied, physical, pressure and changes in unit cell volume from steric changes induced by isovalent substitution. Additionally, for LaAg0.54Au0.46Sb2 anomalies in low temperature electrical transport were observed in the pressure range where the lower charge density wave is completely suppressed.
Rietveld Refinement, Structural Characterization, and Methylene Blue Adsorption of the New Compound Ba0.54Na0.46Nb1.29W0.37O5
Authors: Es-soufi Hicham , Bih Hssain , Bih Lahcen , Rajesh Raman , Lima Alan Rogerio Ferreira , Sayyed M. I. , Mezher Rabih
Published: November 2022

Using the solid-state process, the new compound Ba0.54Na0.46Nb1.29W0.37O5 was effectively produced in a single crystalline phase. The material’s characteristics were determined by X-ray diffraction and Raman techniques. The Rietveld method was applied to refine the structural properties of this sample using X-ray diffraction data and derive the diffraction line profile. The cell parameters a = b = 12.37843 ± 0.02 and c = 3.93526 ± 0.02 were accustomed to crystallizing this compound in the tetragonal tungsten bronze (TTB) structure of the space group P4bm. Thanks to Raman measurements, we were able to detect numerous vibration modes in this crystalline phase. The adsorption of methylene blue (MB) on crystalline phase was studied by UV–visible spectroscopy. On account of methylene blue adsorption on Ba0.54Na0.46Nb1.29W0.37O5, it was discovered that this material can be used to remove organic pollutants and thus be used for water treatment.
Effect of Process Parameters on the Microstructure of Aluminum Alloys Made via Ultrasonic Additive Manufacturing
Authors: Venkatraman Gowtham , Headings Leon M. , Dapino Marcelo J.
Published: November 2022

Ultrasonic additive manufacturing (UAM) has garnered significant interest in the aerospace and automotive industries for its structural lightweighting and multi-material joining capabilities. This paper details the investigation on the effect of process variables on the resultant microstructure of the built-up part using UAM for aluminum 6061. The degree of recrystallization is quantified, and an energy metric, defined using the Read–Shockley relationship, is used to build an energy map of the welded part. The total energy stored in the resultant weld interface microstructure is quantified as a fraction of the input and is found to be about 0.1%. The width, average grain size, and percentage of High Angle Grain Boundaries (% HAGB) were used to compare microstructures of builds prepared using different processing conditions. Welding subsequent weld layers was not found to affect the previous welded layers. The effect of vibration amplitude and travel speed on the as-built microstructure were investigated, and the width of the interface was found to more than double when the weld amplitude is increased from the threshold value for joining (23 μm) and then stabilize at higher weld amplitudes. A better understanding of the effect of processing parameters on as-welded microstructures will assist parameter selection for UAM.
Numerical Investigation of Heat/Flow Transfer and Thermal Stress in an Anode-Supported Planar SOFC
Authors: Cai Weiqiang , Yuan Jinliang , Zheng Qingrong , Yu Wanneng , Yin Zibin , Zhang Zhonggang , Pei Yuyao , Li Shian
Published: November 2022

To elucidate the thermofluid reacting environment and thermal stress inside a solid oxide fuel cell (SOFC), a three-dimensional SOFC model is implemented by using the finite element method in the commercial software COMSOL Multiphysics®, which contains both a geometric model of the full-cell structure and a mathematical model. The mathematical model describes heat and mass transfer, electrochemical reactions, internal reforming reactions, and mechanical behaviors that occur within the cell. A parameter study is performed focusing on the inlet fuel composition, where humidified hydrogen and methane syngas (the steam-to-carbon ratio is 3) as well as the local distribution of temperature, velocity, gas concentrations, and thermal stress are predicted and presented. The simulated results show that the fuel inlet composition has a significant effect on the temperature and gas concentration distributions. The high-temperature zone of the hydrogen-fueled SOFC is located at the central part of units 5, 6, and 7, and the maximum value is about 44 K higher than that of methane syngas-fueled SOFC. The methane-reforming and electrochemical reactions in the anode active layer result in a significant concentration gradient between the anode support layer and the active layer of the methane syngas-fueled SOFC. It is also found that the thermal stress distributions of different fuel inlet compositions are rather different. The maximum stress variation gradient between electrode layers of hydrogen SOFC is larger (44.2 MPa) than that of methanol syngas SOFC (14.1 MPa), but the remaining components have a more uniform stress distribution. In addition, the electrode layer of each fuel SOFC produces a significant stress gradient in the y-axis direction, and stress extremes appear in the corner regions where adjacent assembly components are in contact.
The Clinicopathological Significance of BiP/GRP-78 in Breast Cancer: A Meta-Analysis of Public Datasets and Immunohistochemical Detection
Authors: Direito Inês , Gomes Daniela , Monteiro Fátima Liliana , Carneiro Isa , Lobo João , Henrique Rui , Jerónimo Carmen , Helguero Luisa Alejandra
Published: November 2022

The endoplasmic reticulum chaperone BiP (also known as GRP-78 or HSPA5) maintains protein folding to allow cell proliferation and survival and has been implicated in carcinogenesis, tumor progression, and therapy resistance. BiP’s association with clinical factors and prognostic potential in breast cancer remains unclear. In this work, three types of analysis were conducted to improve the knowledge of BiP’s clinicopathological potential: (1) analysis of publicly available RNA-seq and proteomics datasets stratified as high and low quartiles; (2) a systematic review and meta-analysis of immunohistochemical detection of BIP; (3) confirmation of findings by BiP immunohistochemical detection in two luminal-like breast cancer small cohorts of paired samples (pre- vs. post-endocrine therapy, and primary pre- vs. metastasis post-endocrine therapy). The TCGA PanCancer dataset and CPTAC showed groups with high BiP mRNA and protein associated with HER2, basal-like subtypes, and higher immune scores. The meta-analysis of BiP immunohistochemistry disclosed an association between higher BiP positivity and reduced relapse-free survival. BiP immunohistochemistry confirmed increased BiP expression in metastasis, an association of BiP positivity with HER2 expression, and nuclear BiP localization with higher a tumor stage and poor outcome. Therefore, three independent approaches showed that BiP protein is associated with worse outcomes and holds prognostic potential for breast cancer.
Spatial Distribution Pattern and Risk Assessment of Invasive Alien Plants on Southern Side of the Daba Mountain Area
Authors: Wang Yuanyuan , Deng Hongping , Zuo Youwei , Yang Jun , Yang Yubing , Huang Yan , Qin Qi , Yang Chongyi
Published: November 2022

The southern side of the Daba Mountain area is a hotspot of global biodiversity and an essential barrier promoting ecological security. However, knowledge about the distribution status and transmission pathways of invasive alien species (IAS) in this area is limited. We counted the IAS on the southern side of the Daba Mountain area through sample transects and analyzed the factors affecting their spatial distribution. We also assessed IAS risk using the analytic hierarchy process (AHP), which found 64 IAS belonging to 23 families and 53 genera. Around rivers and roads, the results showed a vertical two-way dispersal pattern. Human and environmental factors, such as a very dense transportation network, can affect the distribution pattern of IAS. AHP assessed 43 IAS (67.19%), primarily distributed in villages and towns, as being of high or medium risk. High- and medium-risk IAS should be the focus of invasion prevention and control, and priority should be given to controlling the spread of IAS around rivers and roads.
Spectrogram Data Set for Deep-Learning-Based RF Frame Detection
Authors: Wicht Jakob , Wetzker Ulf , Jain Vineeta
Published: November 2022

Automated spectrum analysis serves as a troubleshooting tool that helps to diagnose faults in wireless networks such as difficult signal propagation conditions and coexisting wireless networks. It provides a higher monitoring coverage while requiring less expertise compared with manual spectrum analysis. In this paper, we introduce a data set that can be used to train and evaluate deep learning models, capable of detecting frames from different wireless standards as well as interference between single frames. Since manually labeling a high variety of frames in different environments is too challenging, an artificial data generation pipeline was developed. The data set consists of 20,000 augmented signal segments, each containing a random number of different Wi-Fi and Bluetooth frames, their spectral image representations and labels that describe the position and type of frame within the spectrogram. The data set contains results of intermediate processing steps that enable the research or teaching community to create new data sets for specific requirements or to provide new interesting examination examples.
New Insights in Pleural Mesothelioma Classification Update: Diagnostic Traps and Prognostic Implications
Authors: Mastromarino Maria Giovanna , Lenzini Alessandra , Aprile Vittorio , Alì Greta , Bacchin Diana , Korasidis Stylianos , Ambrogi Marcello Carlo , Lucchi Marco
Published: November 2022

The 2021 WHO Classification of Tumors of the Pleura has introduced significant changes in mesothelioma codification beyond the three current histological subtypes—epithelioid, sarcomatoid and biphasic. Major advances since the 2015 WHO classification include nuclear grading and the introduction of architectural patterns, cytological and stromal features for epithelioid diffuse mesothelioma. Mesothelioma in situ has been recognized as a diagnostic category. Demonstration of loss of BAP1 or MTAP by immunohistochemistry, or CDKN2A homozygous deletion by FISH, is valuable in establishing the diagnosis of epithelioid mesothelioma. Recent emerging data proved that grading and histological subtypes have prognostic implications and may be helpful to patient risk stratification and clinical management. Nevertheless, the latest mesothelioma classification increases the already non-negligible diagnostic pitfalls, especially concerning differential diagnosis of pre-invasive tumors. In this review, recent changes in histologic classification of mesothelioma and advances in molecular markers are presented and their relation to diagnostic challenges and prognostic implications is discussed.
Hemoglobin Determination Using Pulse Co-Oximetry and Reduced-Volume Blood Gas Analysis in the Critically Ill: A Prospective Cohort Study
Authors: Czempik Piotr F. , Pluta Michał P. , Krzych Łukasz J.
Published: November 2022

Hospital-acquired anemia is common in patients hospitalized in the intensive care unit (ICU). A major source of iatrogenic blood loss in the ICU is the withdrawal of blood for laboratory testing. The aim of our study was to analyze the feasibility and accuracy of non-invasive spot-check pulse co-oximetry (SpHb), and a reduced-volume blood gas analysis (ABG Hb) for the determination of Hb concentration in critically ill patients. Comparisons between Hb determined with test devices and the gold standard—complete blood count (CBC)—were performed using Bland–Altman analysis and concordance correlation coefficient (CCC). The limits of agreement between SpHb and CBC Hb were –2.0 [95%CI −2.3–(−1.7)] to 3.6 (95%CI 3.3–3.9) g/dL. The limits of agreement between ABG Hb and CBC Hb were −0.6 [95%CI −0.7–(−0.4)] to 2.0 (95%CI 1.9–2.2) g/dL. Spearman’s coefficient and CCC between ABG Hb and CBC Hb were 0.96 (95%CI 0.95–0.97, p < 0.001) and 0.91 (95%CI 0.88–0.92), respectively. Non-invasive spot-check Hb co-oximetry is not sufficiently accurate for the monitoring of hemoglobin concentration in critically ill patients. Reduced volume arterial blood gas analysis has acceptable accuracy and could replace complete blood count for the monitoring of Hb concentration in critically ill patients, leading to a significant reduction in blood volume lost for anemia diagnostics.
A UAV-Swarm-Communication Model Using a Machine-Learning Approach for Search-and-Rescue Applications
Authors: Khalil Hisham , Rahman Saeed Ur , Ullah Inam , Khan Inayat , Alghadhban Abdulaziz Jarallah , Al-Adhaileh Mosleh Hmoud , Ali Gauhar , ElAffendi Mohammed
Published: November 2022

This paper presents a UAV-swarm-communication model using a machine-learning approach for search-and-rescue applications. Firstly, regarding the communication of UAVs, the receive signal strength (RSS) and power loss have been modeled using random forest regression, and the mathematical representation of the channel matrix has also been discussed. The second part consisted of swarm control modeling of UAVs; however, a dataset for five types of triangular swarm formations was generated, and K-means clustering was applied to predict the cluster. In order to obtain the correct swarm formation, the dendrogram of all types was investigated. Finally, the heat map and contour were plotted for all kinds of swarm clusters. Furthermore, it was observed that the RSS of proposed swarms had good agreement with swarm distances.
A Reverberation Suppression Method Based on the Joint Design of a PTFM Waveform and Receiver Filter
Authors: Yue Lei , Liang Hong , Duan Tong , Dai Zezhou
Published: November 2022

Transmitting waveform design and signal processing method optimization are effective ways to improve a sonar system’s detection performance. In this study, the spectrum and ambiguity function characteristics of pulse trains of frequency modulation (PTFM) signals were deduced and analyzed to address the problem of serious reverberation interference in the detection of low-speed targets in shallow water environments. The action mechanisms of PTFM signal parameters on the comb spectrum and bed of nails ambiguity function were identified. PTFM signal parameters were designed according to reverberation suppression requirements. The threshold was calculated using the estimate-before-detect method, and the comb spectrum waveform cognitive filtering detection algorithm is proposed. The simulation and lake experimental results show that the PTFM signals’ reverberation suppression ability for low-speed targets was better than it was for stationary or high-speed targets. The proposed method has good universality, which can improve the output signal-to-reverberation ratio (SRR) by more than 6 dB.
Reservoir Dynamic Interpretability for Time Series Prediction: A Permutation Entropy View
Authors: Sun Xiaochuan , Hao Mingxiang , Wang Yutong , Wang Yu , Li Zhigang , Li Yingqi
Published: November 2022

An echo state network (ESN) is an efficient recurrent neural network (RNN) that is widely used in time series prediction tasks due to its simplicity and low training cost. However, the “black-box” nature of reservoirs hinders the development of ESN. Although a large number of studies have concentrated on reservoir interpretability, the perspective of reservoir modeling is relatively single, and the relationship between reservoir richness and reservoir projection capacity has not been effectively established. To tackle this problem, a novel reservoir interpretability framework based on permutation entropy (PE) theory is proposed in this paper. In structure, this framework consists of reservoir state extraction, PE modeling, and PE analysis. Based on these, the instantaneous reservoir states and neuronal time-varying states are extracted, which are followed by phase space reconstruction, sorting, and entropy calculation. Firstly, the obtained instantaneous state entropy (ISE) and global state entropy (GSE) can measure reservoir richness for interpreting good reservoir projection capacity. On the other hand, the multiscale complexity–entropy analysis of global and neuron-level reservoir states is performed to reveal more detailed dynamics. Finally, the relationships between ESN performance and reservoir dynamic are investigated via Pearson correlation, considering different prediction steps and time scales. Experimental evaluations on several benchmarks and real-world datasets demonstrate the effectiveness and superiority of the proposed reservoir interpretability framework.
Isotherm Theoretical Study of the AlxGa1−xAsySb1−y Quaternary Alloy Using the Regular Solution Approximation for Its Possible Growth via Liquid-Phase Epitaxy at Low Temperatures
Authors: Gastellóu Erick , García Rafael , Herrera Ana M. , Ramos Antonio , García Godofredo , Robles Mario , Rodríguez Jorge A. , Ramírez Yani D. , Carrillo Roberto C.
Published: November 2022

This work presents the theoretical calculation of isotherm diagrams for quaternary alloys of III–V semiconductor compounds with the form IIIxIII1−xVyV1−y. In particular, the isotherm diagrams for the AlxGa1−xAsySb1−y quaternary alloy at low temperatures were calculated (500 °C, 450 °C, 400 °C, and 350 °C). The AlxGa1−xAsySb1−y quaternary alloy was formed from four binary compounds such as GaAs, AlAs, AlSb, and GaSb, all with direct bandgaps. The regular solution approximation was used to find the quaternary isotherm diagrams, represented in four linearly independent equations, which were solved using Parametric Technology Corporation Mathcad 14.0 software for different arsenic and antimony atomic fractions. The results support the possible growth of layers via liquid-phase epitaxy in a range of temperatures from 500 °C to 350 °C, where the crystalline quality could be improved at low temperatures. These semiconductor layers could have applications for optoelectronic devices in photonic communications, thermophotovoltaic systems, and microwave devices with good crystalline quality.
How Does Energy Consumption and Economic Development Affect Carbon Emissions? A Multi-Process Decomposition Framework
Authors: Liu Xiao , Zhang Yancai , Li Yingying
Published: November 2022

Against the background that climate warming has become a global challenge, exploring the factors that drive carbon emissions change is important to achieve emission reduction targets. Because of the differences in economic development, resource endowment, and historical accumulation, different countries generally have significant technological heterogeneity in the carbon generation process. Therefore, the heterogeneity-related factors should also be understood, which can help policy making and responsibility attribution more accurate. As such, this study developed a meta-frontier-based production–theoretical decomposition analysis method to track the progress of carbon emission change in 42 countries during 2012–2019 with production heterogeneity between the countries taken into account. The empirical study draws the following three meaningful conclusions: firstly, the carbon emission process of different countries has clear technological heterogeneity, mainly reflected in aspects of their energy-use efficiency and energy-use technology. Secondly, the decomposition analysis results showed that the potential energy intensity effect and the economic activity effect played the dominant role in driving and reducing carbon emissions, respectively. Additionally, this conclusion is right for all types of countries. Thirdly, the attribution analysis showed that different types of countries have significantly different contributions to the influencing factors of carbon emission changes, among which countries with large energy consumption and large economies need to take more responsibility for emission reduction.
Investigation of the Explosive Characteristics of Ammonium Nitrate and Aluminium-Magnesium Alloy Powder Mixtures
Authors: Paszula Józef , Maranda Andrzej , Kukfisz Bożena , Putko Paulina
Published: November 2022

This paper presents the results of detonation and explosion characteristics for ammonium nitrate, aluminium, and aluminium-magnesium alloy powder mixtures. The following parameters were determined: detonation velocities, blast waves overpressure and their specific impulses. The emission of radiation was recorded, and the history of temperature of the detonation products cloud was established. It was shown that addition of aluminium-magnesium alloy powder increases blast waves’ characteristics. Moreover, it increases the time of the afterburning reaction after detonation and increases the temperature of detonation products.
A Review of the Heterogeneity of Organic-Matter-Hosted Pores in Shale Reservoirs
Authors: Zhao Yanming , Gao Ping , Zhou Qin , Xiao Xianming , Xing Yijie , Liu Wei
Published: November 2022

Organic-matter-hosted pores are fundamental pore spaces in shale reservoirs, which largely control the expulsion and storage of oil and gas. However, the strong heterogeneity of organic pores greatly increases the complexity of the pore network in shale reservoirs, which make shale reservoir evaluation challenging. The heterogeneity of organic pores in shale reservoirs has beenone of the hottest topics of recent years. In this review, the heterogeneity of organic pores in shale reservoirs and their controlling factors are systematically summarized. The formation and evolution of organic pores in shale reservoirs are directly linked to hydrocarbon generation and expulsion,and the heterogeneity of organic pores is a result of various geological and geochemical factors. The development and heterogeneity of organic pores are basically controlled by the differences in kerogen types and maceral compositions of shale deposits, which are mainly attributed to the differencesin hydrocarbon generation capacity of different maceral compositions. Thermal maturation of organic matter is responsible for the formation and evolutionary mechanisms of organic pores and their heterogeneities. With increasing maturity, the increasing trend of pore volume and porosity diminishes. The reduction in macropore volume first appears, and the collapse of macropores could lead to an increase in micropore and mesopore volumes. An important turning point for the thermal evolution of OM is 3.5% Ro. At an Ro greater than 3.5%, the chemical structure of OM is transformed from amorphous carbon to crystalline graphite, and the hydrocarbon generation capacity of the OM has been exhausted, thus, resulting in the destruction of OM-hosted pores. The TOC content and mineral compositions of shale reservoirs affect the development and preservation of organic pores, but enhanced TOC content and brittle minerals may work against the development and preservation of organic porosity. Geological factors, e.g., compaction, diagenesis, pore fluid pressure and tectonic deformation, can also affect the organic pore structure of shale reservoirs to some extent, and their differences can enhance the heterogeneity of organic pores. On the basis of the above-mentioned understandings, this review also puts forward and discusses the problems existing in the current study of organic pore and its heterogeneity of shale reservoirs, and points out further research directions.
Evolutionary Game of Actors in China’s Electric Vehicle Charging Infrastructure Industry
Authors: Li Mu , Liu Yingqi , Yue Weizhong
Published: November 2022

China proposed a development direction of “new infrastructure” in 2020, due to the ongoing scientific and technological revolution and industrial transformation. The charging station industry is one of the seven industries of the “new infrastructure”. Hence, it is of great importance to study China’s electric vehicle charging infrastructure industry. Based on game theory, this study analyzes the game strategies for the evolution of actors in China’s electric vehicle charging infrastructure industry. Firstly, the Chinese government has classified the industry according to the subsidy for charging piles and battery swapping stations. Then, the government, operators, and consumers constructed an evolutionary game model. The results show that: (1) under the investment subsidy mode, the purchase cost that consumers invest in purchasing traditional fuel-consuming vehicles has a positive impact on the operator’s production enthusiasm. In addition, the government’s subsidy amount has a positive impact on consumers’ decision to purchase battery-swappable electric vehicles; and (2) under the operational subsidy mode, due to the government’s strong supervision of the industry, there is a positive correlation between the word-of-mouth effect and the consumer’s decision to buy rechargeable electric vehicles.
Aging of Polymeric Insulators under Various Conditions and Environments: Another Look
Authors: Qiao Xinhan , Ming Yue , Xu Ke , Yi Ning , Sundararajan Raji
Published: November 2022

Polymeric insulators have lightweight, excellent hydrophobicity and convenient transportation and installation. They are widely used in the external insulation for distribution and transmission lines. However, due to the long-term effects of pollution, ultraviolet radiation, discharge, temperature, humidity, altitude and other natural and complex environmental and service factors, the silicone rubber and other materials of polymeric insulators gradually age and lose their hydrophobicity and electrical insulation characteristics. The operability is significantly reduced, which seriously affects the safety and reliability of the power system. Hence, there is a need for assessing and evaluating the long-term aging and degradation of polymeric insulators under various operating conditions and environments. In this review, the various aging and characterization techniques of the polymeric insulators and their aging performance under the action of multiple factors are discussed. To enhance the performance of polymeric insulators, nano-coating, surface treatment and other techniques are also indicated. In addition, future potential fields that should be explored from a high-voltage electrical insulation perspective are also presented.
Optimization of the Selected Parameters of Single-Family House Components with the Estimation of Their Contribution to Energy Saving
Authors: Jezierski Walery , Sadowska Beata
Published: November 2022

Knowledge of the influence of factors determining energy consumption in buildings is very important for the possibility of effective energy saving. This article describes the results of an original study on the analysis of the annual energy demand for heating (QH;nd), cooling (QC;nd), and annual usable energy demand (QH/C;nd = QH;nd + QC;nd) assumed as objective functions of a designed single-family building, which can be classified as a typical representative of currently built houses in Poland. It was assumed that the object of study was located in the climatic conditions of north-eastern Poland. The study takes into consideration three groups of selected parameters: architectural/spatial, structural, and physical properties of windows. The research was carried out in a single-family building, as energy consumption in residential buildings accounts for a significant part of the total energy consumption in buildings. In the group of architectural/spatial parameters, the height of rooms in the building (h) and the window area change coefficient (k) were taken into consideration. The design parameters pertained to the solutions of building components: the density of the material of the inner layer of the external walls (ρ1), the density of the material of internal walls (ρ2), and the thickness of internal walls (d). In the third group of parameters, the heat transfer coefficient of the glazing (Ug) and the total solar transmittance of the glazing (g) were considered. Deterministic mathematical models of these dependencies were developed on the basis of the results of a computational experiment, obtained by performing a simulation with the use of the DesignBuilder software, based on the EnergyPlus computational engine. The models allowed the authors to estimate the degree and nature of the influence of the examined factors on the building’s energy demand. As a result of the optimization of parameters according to the energy criterion, the contribution of each of the three groups of parameters to energy saving was determined. Deterministic numerical optimization using MATLAB was applied. It turned out that the factors from the first group played the most important role in energy savings (40.0%), and the factors from the third group contributed slightly less (25.7%). The contribution of the characteristics from the second group was 4.2% of the total value of energy saving. This information can be useful to scientists, as well as engineers and policymakers, in making correct decisions when designing new residential buildings.
The Analysis of Selected Factors Improving the Cargo Susceptibility to Modal Shift
Authors: Zając Mateusz
Published: November 2022

The issue of shifting loads from road to rail is always vivid when it comes to reducing CO2 emissions from transport. Practically not every load transported by road vehicles over a long distance can be transferred to rail. Additionally, the potential of the railway lines is limited, which means that the network is not able to accept huge amounts of loads from road transport. In the article, attention was paid to the typology of cargo susceptible to changing the means of transport. The article discusses the factors influencing the real possibility of CO2 reduction by changing the mode of transport. The analysis and calculation example of the selected region in Poland is presented.
Fault Diagnosis Algorithm of Transformer and Circuit Breaker in Traction Power Supply System Based on IoT
Authors: Wu Zhensheng , Zhang Zhongli , Wang Wenlin , Xing Ting , Xue Zhao
Published: November 2022

Transformers and circuit breakers are essential equipment in traction power supply systems. Once a fault occurs, it will affect the train’s regular operation and even threaten passengers’ personal safety. Therefore, it is essential to diagnose the faults of the transformers and circuit breakers of the traction power supply system. At present, power companies have made many achievements in fault diagnosis of power equipment, but there are still problems with real-time and accuracy. The Internet of Things (IoT) is a technology that connects different types of terminal devices for information exchange and communication to achieve intelligence. It includes data acquisition and transmission, information interaction, processing, and decision-making from bottom to top. It uses sensor terminals to obtain real-time status information on electrical equipment. Moreover, it conducts real-time monitoring and intelligent processing of the equipment status of the traction power supply system. In this paper, the multi-data fusion technology of the IoT combines the real-time information of electrical equipment with fault diagnosis to realize the fault diagnosis of transformers and circuit breakers. First, we built an equipment fault diagnosis system based on the multi-terminal data fusion technology of the IoT. Secondly, the transformer fault diagnosis model is established. We adopt the BP neural network algorithm based on particle swarm optimization (PSO) to realize transformer fault diagnosis and use PSO to optimize the feature subset to improve the diagnosis performance. Finally, the fault diagnosis model of the vacuum circuit breaker is established. We select the current change and time node as typical fault feature quantities and use the PSO–BP neural network algorithm to realize the fault diagnosis of the circuit breaker.
Simple Diagnosis of Lifetime Characteristics of Used Automotive Storage Battery Cells
Authors: Shimoi Norihiro , Tohji Kazuyuki
Published: November 2022

In constructing a nanogrid for the effective use of renewable energy, such as solar power, the use of storage batteries is considered as a stabilizer for capturing renewable energy and outputting it in an energy-saving manner. Storage batteries that are included in a battery management system that includes their reuse in a vehicle are expected to be discharged into the market in large quantities over their long lifetime. Storage battery modules obtained from an unspecified number of electric vehicles (EVs), hybrid vehicles (HVs) and plug-in hybrid vehicles (PHVs) will vary in their charge/discharge capacity from module to module and it is crucial to determine the stability in terms of the state of charge and the state of health of the modules before their reuse. However, in an automotive storage battery module, multiple battery cells are connected in series or in parallel, and there is no established method of managing the variation in the output of each battery cell. Therefore, in this study, we propose an accurate charge–discharge state estimation technique for each cell using impedance characteristic evaluation based on an electrochemical method as a simple and quick method of grasping the charge–discharge performance of storage batteries equipped in a vehicle.
Counting People and Bicycles in Real Time Using YOLO on Jetson Nano
Authors: Gomes Hugo , Redinha Nuno , Lavado Nuno , Mendes Mateus
Published: November 2022

Counting objects in video images has been an active area of computer vision for decades. For precise counting, it is necessary to detect objects and follow them through consecutive frames. Deep neural networks have allowed great improvements in this area. Nonetheless, this task is still a challenge for edge computing, especially when low-power edge AI devices must be used. The present work describes an application where an edge device is used to run a YOLO network and V-IOU tracker to count people and bicycles in real time. A selective frame-downsampling algorithm is used to allow a larger frame rate when necessary while optimizing memory usage and energy consumption. In the experiments, the system was able to detect and count the objects with 18 counting errors in 525 objects and a mean inference time of 112.82 ms per frame. With the selective downsampling algorithm, it was also capable of recovering and reduce memory usage while maintaining its precision.
Numerical Investigation of a Fuel Cell-Powered Agricultural Tractor
Authors: Martini Valerio , Mocera Francesco , Somà Aurelio
Published: November 2022

In recent years, growing awareness about environmental issues is pushing humankind to explore innovative technologies to reduce the anthropogenic sources of pollutants. Among these sources, internal combustion engines in non-road mobile machinery (NRMM), such as agricultural tractors, are one of the most important. The aim of this work is to explore the possibility of replacing the conventional diesel engine with an electric powertrain powered by a hybrid storage system, consisting of a small battery pack and a fuel-cell system. The battery pack (BP) is necessary to help the fuel cell manage sudden peaks in power demands. Numerical models of the conventional powertrain and a fuel-cell tractor were carried out. To compare the two powertrains, work cycles derived from data collected during real operative conditions were exploited and simulated. For the fuel-cell tractor, a control strategy to split the electric power between the battery pack and the fuel cell was explored. The powertrains were compared in terms of greenhouse gas emissions (GHG) according to well-to-wheel (WTW) equivalent CO2 emission factors available in the literature. Considering the actual state-of-the-art hydrogen production methods, the simulation results showed that the fuel-cell/battery powertrain was able to accomplish the tasks with a reduction of about 50% of the equivalent CO2 emissions compared to traditional diesel-powered vehicles.
Fly Ash-Based Geopolymers as Lower Carbon Footprint Alternatives to Portland Cement for Well Cementing Applications
Authors: Horan Cameron , Genedy Moneeb , Juenger Maria , van Oort Eric
Published: November 2022

Ordinary Portland cement (OPC) is currently the preferred material for the creation of barriers in wells during their construction and abandonment globally. OPC, however, is a very carbon-intensive material with some inherent technical weaknesses. These include a low casing-to-cement bond strength which may allow for the formation of micro-annuli, which in turn can become a conduit for greenhouse gas transport (primarily of methane, a powerful greenhouse gas) to surface. Alkali-activated materials (AAMs), also known as geopolymers, have a much lower manufacturing carbon footprint than OPC and can be a good alternative to OPC for primary and remedial well cementing applications. This paper reports on a comprehensive study into the use of Class F fly ash-based geopolymers for a large variety of downhole well conditions, ranging from lower-temperature surface and intermediate casing cementing conditions to much higher temperature conditions (up to 204 °C (400 °F)) that can be encountered in high-pressure, high-temperature (HPHT) wells and geothermal wells. The rheological and mechanical properties of alkali-activated fly ash with six different sodium and potassium-based hydroxide and silicate activators were measured and compared to OPC. The results show that geopolymer formulation properties can be tuned to a variety of downhole cementing conditions. With the application of a suitable alkaline activator, geopolymers exhibit good compressive and tensile strength and an outstanding casing-to-cement bond strength of up to 8.8 MPa (1283 psi), which is more than an order of magnitude higher than OPC. This has important implications for preventing the creation of micro-annuli as a result of casing-to-cement interface debonding, thereby preventing the potential leakage of methane to the atmosphere on future wells that use geopolymers rather than OPC for barrier creation.
Effect of Cellulose Material-Based Additives on Dispersibility of Carbon Nanotubes
Authors: Lee Seunghyeon , Lee Ajeong , Baek Seungyeop , Sung Yonmo , Jeong Hyomin
Published: November 2022

In nanoscience, nanotechnology is applied to various technologies, and research is actively being conducted. As the application of multi-walled carbon nanotubes (MWCNTs) in various fields increases, efforts have been made to develop dispersion and functionalization technologies. In order to effectively use MWCNT nanofluids, it is most important to solve the problem of dispersion. In this study, MWCNTs were improved in dispersibility and functionalized through various chemical and mechanical treatments. In addition, MWCNTs aggregation was alleviated by using cellulose nanocrystal (CNC) as a dispersant. The processing results of MWCNTs and CNC were analyzed through transmission electron microscopy (TEM) and the dispersion was characterized by UV–Vis spectroscopy. The addition of CNC to MWCNTs has been confirmed to have high dispersibility and improved stability compared to untreated MWCNTs, and this effect affects the quality of the machine.
Topology Optimization Design of Micro-Channel Heat Sink by Considering the Coupling of Fluid-Solid and Heat Transfer
Authors: Wang Yue , Wang Jiahao , Liu Xiaomin
Published: November 2022

To investigate the effect of the target weight coefficient on the structure design of the micro-channel heat sink, an innovative method for the topology optimization design of micro-channel structures with different bifurcation angles is adopted. In this study, the improved interpolation function, density filtering, and hyperbolic tangent projection methods are adopted to obtain a clear topological structure of the micro-channel heat sink. The heat transfer of the micro-channel heat sink under different bifurcation angles is compared. At the same time, the influence of the two different objective functions, heat transfer, and flow energy consumption, is analyzed in the topology optimization of micro-channel heat sinks. The results show that when the bifurcation angle is 135°, both the heat transfer and the average outlet temperature of the micro-channel heat sink obtain the maximum value, and the heat transfer effect is the best. With the increase of the heat transfer weighting coefficient, the distribution of solid heat sources in the main channel increases, and the refinement of the branch channels also increases. On the other hand, although the heat transfer effect of the micro-channel heat sink is the best, the corresponding flow energy consumption is larger.
Smart-City Citizen Engagement: The Answer to Energy Savings in an Economic Crisis?
Authors: Jasińska-Biliczak Anna
Published: November 2022

As the populations of cities grow, it is obvious that they need more and more resources. Energy is currently one of the most desirable resources due to the economic and energy crisis, but it needs to be used in a sustainable manner. There are cities that achieve smart city (SC) status that provide smart policies towards sustainable development. The aim of the present paper is to determine whether citizen engagement in SC can contribute to reduced energy consumption in the current economic crisis. The paper presents an original survey intended to collect primary data and a study conducted based exclusively on qualitative methods. The results concern a broad and multifaceted review of literature concerning SCs, as well as citizens’ engagement and their role in SC development. The study allows understanding of the economic phenomena taking place in SCs and filling the gaps regarding the behavior of SC citizens. It shows that SCs create smart citizens that feel responsible for the environment and aggregate a more responsible environment for public actions with citizen engagement. In terms of energy savings, the study shows that it is possible to specify the economic and energy benefits of SC citizen engagement.
Isolation of Yeasts from Some Homemade Fermented Cow-Milk Products of Sikkim and Their Probiotic Characteristics
Authors: Lama Sonam , Tamang Jyoti Prakash
Published: November 2022

Dahi and chhurpi are the homemade, mildly acidic and mouthfeel fermented dairy products of Sikkim in India. Since yeasts co-exist among traditional fermented dairy foods, we believe that some species of yeasts may have some probiotic properties. Hence, the present study is aimed at screening some probiotic yeasts from dahi and chhurpi. A total of 3438 yeasts were isolated from 40 samples of dahi (1779 isolates) and 40 chhurpi (1659 isolates) and were preliminarily screened for probiotic properties on the basis of survival in low pH, resistance to bile salts and the percentage of hydrophobicity, out of which only 20 yeasts were selected for in vitro and genetic screening of probiotic properties. Saccharomyces cerevisiae DJT-2 and Debaryomyces prosopidis CPA-55 showed the highest hydrophobicity of 97.54% and 98.33%, respectively. S. cerevisiae DRC-42 and S. cerevisiae CGI-29 showed 93.88% and 91.69% auto-aggregation, respectively. All yeasts showed co-aggregation properties against pathogenic bacteria. Kluyveromyces marxianus DPA-41 and Pichia kudriavzevii CNT-3 showed excellent deconjugation activities. Probiotic genes for acid tolerance, bile tolerance, adhesion and antimicrobial activity were detected in S. cerevisiae DAO-17, K. marxianus DPA-41, S. cerevisiae CKL-10 and P. kudriavzevii CNT-3. Based on the results of in vitro and genetic screening of probiotic yeasts strains, S. cerevisiae DAO-17 (dahi), S. cerevisiae CKL-10 (chhurpi), P. kudriavzevii CNT-3 (chhurpi) and K. marxianus DPA-41(dahi) were selected as the potential probiotic yeasts.