bluuebunny/crossref_metadata_2025 huggingface dataset:
Distributed leadership, self-efficacy and wellbeing in schools: A study of relations among teachers in Shanghai
Authors: Liu Ji , Qiang Faying , Kang Haihua
Published: May 2023

Empowering teachers through sharing communal decision-making responsibility via distributed leadership has been shown to be effective for positive change in schools. While studies have proposed various psychosocial channels through which positive effects on teacher wellbeing can be realized, there is scarce evidence on how this relationship is influenced by teacher self-efficacy. This study examines how self-efficacy mediates the relationship between distributed leadership, job and career wellbeing among secondary school teachers, employing a partial least-squares structural equation model using the Teaching and Learning International Survey (TALIS) Shanghai dataset (N = 3799). Results show that distributed leadership is positively associated with improvement in self-efficacy (std. β = 0.33, P < 0.001), job wellbeing (std. β = 0.51, P < 0.001), and career wellbeing (std. β = 0.45, P < 0.001), whereas self-efficacy is positively correlated with job wellbeing (std. β = 0.15, P < 0.001), but not career wellbeing (std. β = −0.01, P = 0.69). In terms of mediation effects, self-efficacy positively mediates the relationship between distributed leadership and job wellbeing (std. β = 0.05, P < 0.001), but distributed leadership does not indirectly influence career wellbeing (std. β = −0.002, P = 0.70) via channels through self-efficacy.
Approximating prediction error variances and accuracies of estimated breeding values from a SNP–BLUP model for genotyped individuals
Authors: Li L. , Gurman P. M. , Swan A. A. , Tier B.
Published: May 2023

Context The accuracy of estimated breeding values (EBVs) is an important metric in genetic evaluation systems in Australia. With reduced costs for DNA genotyping due to advances in molecular technology, more and more animals have been genotyped for EBVs. The rapid increase in genotyped animals has grown beyond the capacity of the current genomic best linear unbiased prediction (GBLUP) method. Aims This study aimed to implement and evaluate a new single-nucleotide polymorphism (SNP)–BLUP model for the computation of prediction error variances (PEVs) to accommodate the increasing number of genotyped animals in beef and sheep single-step genetic evaluations in Australia. Methods First, the equivalence of PEV estimates obtained from both GBLUP and SNP-BLUP models was demonstrated. Second, the computing resources required by each model were compared. Third, within the SNP-BLUP model, the PEVs obtained from subsets of SNP were evaluated against those from the complete dataset. Fourth, the new model was tested in the Australian Merino sheep and Angus beef cattle datasets. Key results The PEVs of genotyped animals calculated from the SNP–BLUP model were equivalent to the PEVs derived from the GBLUP model. The SNP–BLUP model used much less time than did the GBLUP model when the number of genotyped animals was larger than the number of SNPs. Within the SNP–BLUP model, the running time could be further reduced using a subset of SNPs makers, with high correlations (>0.97) observed between the PEVs obtained from the complete dataset and subsets. However, it is important to exercise caution when selecting the size of the subsets in the SNP–BLUP model, as reducing the subset size may result in an increase in the bias of the PEVs. Conclusions The new SNP-BLUP model for PEV calculation for genotyped animals outperforms the current GBLUP model. A new accuracy program has been developed for the Australian genetic evaluation system which uses much less memory and time to compute accuracies. Implications The new model has been implemented in routine sheep and beef genetic evaluation systems in Australia. This development ensures that the calculation of accuracies is sustainable, with increasing numbers of animals with genotypes.
Effect of feedstock bimodal powder mixture and infiltration process on mechanical behaviour of binder jetting processed 316L stainless steel
Authors: Liang Xuhao , Meng Xiaoyan , Ni Peishen , Zhao Zhe , Deng Xin , Chen Guanqiao , Chen Yongxuan , Li Shidi , Wu Shanghua , Liu Jinyang , Qu Zhi , Jin Feng
Published: May 2023

Binder jetting additive manufacturing (BJAM) is a widely studied technique fabricating metal parts. In this study, bimodal 316L stainless steel powder mixture of coarse (D50 – 34.1μm) and fine (D50 – 6.28μm) powders were designed for BJAM. Infiltration was used to improve the density of BJAMed parts. Bimodal powder mixture showed clear advantage over unimodal powder system on density and mechanical property of BJAMed parts. Upon solid-phase sintering, BJAMed 316 stainless steel of bimodal powder mixture (9:1 mass ratio of coarse to fine powder) showed relative density 97.19% and tensile strength 343.62 MPa, as compared with relative density 84.55% and tensile strength 291.59 MPa for pure coarse powder. For the same bimodal powder mixture, bronze infiltration, compared with solid-phase sintering, resulted in noticeably higher relative density 99.92% and tensile strength 621.63 MPa. Compared with solid-phase sintering, infiltration significantly reduced the volumetric shrinkage.
Online risks at adolescence. Design and validation of a Parental Mediation Scale for Information and Communication Technologies (Riesgos en línea para los adolescentes. Diseño y validación de una escala de mediación parental para las tecnologías de la información y la comunicación — TIC)
Authors: Gervilla-García Elena , Lloret-Irles Daniel , Cabrera-Perona Victor , Fernández-Martínez Iván , Anupol Joella
Published: May 2023

Parental mediation in the use of Information and Communication Technologies (ICTs) is a protective factor against adolescents’ online risk behaviours. This study aimed to design an assessment scale of parental mediation referred by minors and to explore its structure and psychometric properties. A total of 560 secondary education students (47.5% girls) informed, in addition to parental mediation, about their habits of connection and online communication, privacy and risky online behaviour, and cyber-victimization. Data revealed a Parental Mediation Scale for ICTs (EMP-TIC) composed of 28 items distributed in five dimensions: active regulation, restrictive regulation, co-use, software monitoring and personal monitoring, which explain 55.98% of the variance. The dimensions of monitoring and co-use showed significant positive correlations with cyber-victimization. Higher scores in parental mediation are associated with greater privacy. The Parental Mediation Scale (EMP-TIC) structure is coherent to previous theoretical proposals. EMP-TIC shows adequate psychometric properties and provides information about the parental patterns in the use of ICTs. The scale can be used as a total score of parental mediation or for each of the five included domains.
Towards a free energy-based elastic network model and its application to the SARS-COV2 binding to ACE2
Authors: Na Hyuntae , Song Guang
Published: May 2023

Classical normal mode analysis (cNMA) is a standard method for studying the equilibrium vibrations of macromolecules. A major limitation of cNMA is that it requires a cumbersome step of energy minimization that also alters the input structure significantly. Variants of normal mode analysis (NMA) exist that perform NMA directly on PDB structures without energy minimization, while maintaining most of the accuracy of cNMA. Spring-based NMA (sbNMA) is such a model. sbNMA uses an all-atom force field as cNMA does, which includes bonded terms such as bond stretching, bond angle bending, torsional, improper, and non-bonded terms such as van der Waals interactions. Electrostatics was not included in sbNMA because it introduced negative spring constants. In this work, we present a way to incorporate most of the electrostatic contributions in normal mode computations, which marks another significant step toward a free-energy-based elastic network model (ENM) for NMA. The vast majority of ENMs are entropy models. One significance of having a free energy-based model for NMA is that it allows one to study the contributions of both entropy and enthalpy. As an application, we apply this model to study the binding stability between SARS-COV2 and angiotensin converting enzyme 2 (or ACE2). Our results show that the stability at the binding interface is contributed nearly equally by hydrophobic interactions and hydrogen bonds.
Individual bias and fluctuations in collective decision making: from algorithms to Hamiltonians
Authors: Sarkanych Petro , Krasnytska Mariana , Gómez-Nava Luis , Romanczuk Pawel , Holovatch Yurij
Published: May 2023

In this paper, we reconsider the spin model suggested recently to understand some features of collective decision making among higher organisms (Hartnett et al 2016 Phys. Rev. Lett.
116 038701). Within the model, the state of an agent i is described by the pair of variables corresponding to its opinion

S
i

=
±
1

and a bias ω

i
toward any of the opposing values of S

i
. Collective decision making is interpreted as an approach to the equilibrium state within the nonlinear voter model subject to a social pressure and a probabilistic algorithm. Here, we push such a physical analogy further and give the statistical physics interpretation of the model, describing it in terms of the Hamiltonian of interaction and looking for the equilibrium state via explicit calculation of its partition function. We show that, depending on the assumptions about the nature of social interactions, two different Hamiltonians can be formulated, which can be solved using different methods. In such an interpretation the temperature serves as a measure of fluctuations, not considered before in the original model. We find exact solutions for the thermodynamics of the model on the complete graph. The general analytical predictions are confirmed using individual-based simulations. The simulations also allow us to study the impact of system size and initial conditions on the collective decision making in finite-sized systems, in particular, with respect to convergence to metastable states.
Isotopic and elemental analysis by electrostatic energy analyzer laser ablated time-of-flight mass spectrometer
Authors: Shah Mehmood , Qureshi Shakir Hussain , Alvi Zeeshan Ahmed , Waheed Abdul
Published: May 2023

In this work, we present a modified setup of the time of flight (TOF) mass spectrometer. It consists of a laser ablation source, and a Q-switched Nd:YAG laser (532 nm, 100 mJ, 7 ns) integrated with a linear TOF mass spectrometer coupled with an electrostatic energy analyzer (EEA). Ions are detected by a channeltron electron multiplier assembled with EEA. The main objective of this work is to resolve the ion’s initial energy problem and improve the reproducibility of the results. Employing this newly developed setup the elemental analysis of a known sample was performed for different laser energies and found no shift in the position of the ions signals on the time scale. In addition to elemental analysis, isotopic compositions of lithium, titanium, copper, and silver samples have been also derived. Our results are in good agreement with their natural abundance. The design parameters of the instrument were optimized. The mass calibration was achieved by measuring the flight time of various ions; Li+, Ti+, Cu+, and Ag+.
Echoes of axial gravitational perturbations in stars of uniform density*
Authors: Lin Kai , Qian Wei-Liang
Published: May 2023

This study investigates the echoes in axial gravitational perturbations in compact objects. Accordingly, we propose an alternative scheme of the finite difference method implemented in two coordinate systems, where the initial conditions are placed on the axis of the tortoise coordinate with appropriate boundary conditions that fully respect the causality. The scheme is then employed to study the temporal profiles of the quasinormal oscillations in the Schwarzschild black hole and uniform-density stars. When presented as a two-dimensional evolution profile, the resulting ringdown waveforms in the black hole metric are split into reflected and transmitted waves as the initial perturbations evolve and collide with the peak of the effective potential. Meanwhile, for compact stars, quasinormal oscillations might be characterized by echoes. Consistent with the causality arguments, the phenomenon is produced by the gravitational waves bouncing between the divergent potential at the star's center and the peak of the effective potential. The implications of the present study are also discussed herein.
Intensity pseudo-localized phase in the glassy random laser
Authors: Niedda Jacopo , Leuzzi Luca , Gradenigo Giacomo
Published: May 2023

Evidence of an emergent pseudo-localized phase characterizing the low-temperature replica symmetry breaking phase of the complex disordered models for glassy light is provided in the mode-locked random laser model. A pseudo-localized phase corresponds to a state in which the intensity of light modes is neither equipartited among all modes nor strictly condensed on few of them. Such a hybrid phase, recently characterized as a finite size effect in other models, such as the discrete non-linear Schrödinger equation, in the low temperature phase of the glassy random laser appears to be robust in the limit of large size.
Dynamic Monitoring System of Oil Pipeline Leakage for Oil and Gas Safety
Authors: Feng Yan
Published: May 2023

The conventional oil pipeline leakage dynamic monitoring system has the problem of imperfect risk assessment link, which leads to the long alarm response time of the system. An oil and gas safety oriented oil pipeline leakage dynamic monitoring system is designed. Hardware part: select MLLD sensor as voltage acquisition device, and connect RS-485 serial standard bus and other circuit devices. Software part: identify the leakage hazard source of oil pipeline, capture the corresponding characteristic points of leakage negative pressure wave, determine the location of leakage point, build the risk assessment model based on oil and gas safety theory, design the safety management function of dynamic monitoring system software, and clarify the potential safety hazards of oil and gas pipeline. Experimental results: the average alarm response time of the oil pipeline leakage dynamic monitoring system based on data mining in this paper and the other two systems are 95.746s, 122.026s and 122.426s respectively, which proves that the oil pipeline leakage dynamic monitoring system integrating oil and gas safety theory has a higher value.
A Power System Reserve Configuration Solution That Satisfies the Frequency Stability Constraint Under the Given New Energy Index
Authors: Song Shaoqun , Liu Zhixuan , Xin Zhilei , Wang Ziqi , Fan Runsheng , Xie Yan , Chen Zhi , Tang Xiaojun
Published: May 2023

Aiming at the problem of frequency stability and voltage stability of a new power system, this paper provides a new energy index method based on frequency stability constraints in the standby category of the new power system. Several concepts, such as maximum disturbance constraint and minimum reserve capacity, are proposed. Two constraints, power balance, and frequency constraint are set, and the factors to be considered, such as load frequency effect, security and control measure, demand-side response, and primary frequency change amplitude of each type of unit, are specified. Through analysis and study of regional data, the peak load of power grid new energy is a given index in a given scenario, according to the research of regional power grid in each category of a frequency modulation amplitude, the installed capacity is set to build a solution, to the problem of frequency stability caused by clean energy consumption, thus determine the ratio of each category of power output and heat capacity. Finally, according to the actual data of one regional power grid, the PSD-BPA power system simulation software is used to verify the effectiveness of the method.
Study on the Optimal Configuration of GSHP in Regional Integrated Energy Systems Considering the Uncertainty of New Energy
Authors: Wang Baoshi , Lv Dongsheng , Wang Duo , Liu Bin
Published: May 2023

The study of regionally integrated energy system optimization problems is of great significance and usefulness for the development of the energy Internet. Regional integrated energy system planning and optimization modeling is the basis for rational system configuration and economical operation. It is one of the key issues in the development of integrated regional energy systems. The optimization of a regionally integrated energy system is studied in this paper. The uncertainty of wind power generation and photovoltaic power generation and the characteristic of CHP is considered. Were established. On this basis, Considering the uncertainty of new energy, a GSHP optimal allocation model based on two-layer optimization is established. A two-level optimization model is introduced. A genetic algorithm is applied to the upper layer, and a genetic algorithm is applied to the lower layer to analyze the nonlinear programming problem. Finally, different system configuration schemes are proposed and computationally solved, combined with examples for case studies to verify the feasibility of the established regional integrated energy system optimization model.
Research on Interconnection Scheme of Renewable Energy in Substation
Authors: Liu Xiaobo , Yu Xiangyang , Miao Yun , Shi Liang , Fan Zikai
Published: May 2023

As one of the carriers of power transmission and transformation in the power system, the traditional substation has a relatively single function. To make full use of renewable energy to generate electricity, the rate of station power consumption needs to be reduced, and the goal of “zero-carbon” substation construction needs to be achieved. The use of renewable distributed power substation station power systems is a valuable research topic. This paper takes the substation as the research object, fully explores the characteristics of the strong flexibility of distributed solar energy, and analyzes the utilization form and access method of renewable distributed energy in the substation. The research station power microgrid system design scheme, mainly including system architecture design, the equipment selection and configuration principles along with the load in the substation station, proposes multiple new energy application scenarios, which have certain reference significance and promotion application value for the future transformation of traditional substations to integrated energy stations with energy interconnection.
Three-dimensional Numerical Simulation of Entrained-Flow Gasifier and Influence of Coal Distribution at the Inlet
Authors: Chen Wei , Wei Zhaofu , Ge Zhihong , Zhou Quan , Guo Jinjun , Zhang Wenbin , Jiang Congbin , Ding Jianping
Published: May 2023

The research object in this paper is an industrial HTL gasifier in a plant. A three-dimensional model is built. The chemical percolation devolatilization (CPD) model is used to calculate the pyrolysis reaction. Considering the gas diffusion in the inner pores of the particle and the evolution of pore structure, the random pore model (RPM) was used to simulate the chemical reaction on the particle surface, and the gasification reaction kinetic parameter of char was measured by high-pressure thermogravimetry analysis. The slag model was constructed to describe the formation process and distribution of slag. Through the coupling of the above models, a simulation method that combines several submodels for the entrained flow gasifier is built, and the results from simulation are in good agreement with the industrial data. Furthermore, the effect of the uniformity of pulverized coal injection was analyzed by this method. The simulation results reflect that the asymmetric feed of coal will affect gas-solid mixing and reduce carbon conversion, and it leads to a higher local wall temperature and a lower ratio of crude slag to fine slag.
Study on Heat Transfer Design of Green Energy-saving Heating Pipe
Authors: Gui Zetao , Chen Peng , Lu Shengya
Published: May 2023

To design a green energy-saving heating pipe, this paper studied the structural transformation of the heating pipe and carried out the effect simulation analysis. The key is to add an impeller device inside the ordinary heating pipe to convert part of the kinetic energy of the fluid in the heating pipe into the mechanical energy of the impeller. The energy generated by the rotation of the impeller can be transferred through gears, connecting rods, and other components and converted into heat energy for recovery in the boiler room to achieve the reheating effect. This design model is mainly used by Solid works and then imported into ANSYSF Fluent for numerical simulation to analyze and study the fluid around the impeller. The result showed that the flow velocity of the fluid around the impeller was reduced, and the local resistance loss was negligible. Meanwhile, part of the kinetic energy of the fluid has been converted into the mechanical energy of the impeller, effectively realizing energy saving.
Research on Operation Control Strategy of Wind and Solar Storage Systems Considering High Ratio of New Energy Access
Authors: Yu Changle , Li Wenwen , Yang Shoulian , Zhang Su , Xu Dahai , Zhao Hongbo
Published: May 2023

High proportion of distributed new energy generation, DG) Connect to the grid to mitigate problems such as fossil energy shortages and the threat of global climate change. However, distributed new energy has the characteristics of fluctuation and uncertainty of output, so it will bring some difficulties to energy consumption after the high proportion is connected to the power grid. Given the above problem, the uncertainty of wind and solar output is considered in this paper to ensure that accuracy and the stability of the power grid operation after a large amount of distributed energy is accessed, with 8,760 hour-by-hour power generation data throughout the year as an input. Three kinds of wind and solar storage system operation control strategies are compared. Using storage battery energy storage method and multiple energy storage methods on the fly surplus storage, coordinated control of the system, and setting different discharge priorities in the energy storage portion, increase real-time and ordered energy consumption.
Application of Mobile Energy Storage System in Dynamic Capacity Increasing Scenario
Authors: Zhu Hui , Wang Qingwei , Fan Yong , Xing Yu , Li Honglei
Published: May 2023

Aiming at the problem of insufficient capacity caused by the intermittent peak power consumption of some small and medium-sized industrial and commercial power users, the electrochemical energy storage on the customer side can exert a dynamic capacity increase effect, while taking into account peak valley arbitrage and emergency power protection functions. The mobile energy storage system further increases the flexibility of the energy storage system and the applicability of scenarios. It can be matched with the smart cloud platform of energy storage on the customer side. The business model under the application scenario has a good market promotion prospect. Through the actual case analysis, it is proved that the system and the model meet the theoretical expectation.
Optimization Planning Method for Power Supply Layout of Multi-Energy Power System
Authors: Li Shilong
Published: May 2023

With the continuous expansion of the scale of renewable energy generation and the rapid development of its technology, the forms of power grid become more diverse. Meanwhile, the coupling and uncertainty of various heterogeneous energy resources will significantly change the characteristics and dynamic balance mechanism of the power system. Power generated from renewable energy sources such as wind and light is uncertain and uncontrollable, and such renewable energy enjoys complementary characteristics across time and space. In this paper, we investigate the uncertainty of renewable energy and its complementary space-time characteristics among various power sources and propose to take advantage of the synergistic effects of different forms of energy to realize optimal allocation of resources in a multi-energy power system on a larger scale. Taking the newly built energy base in northwest China as an example, the power distribution of multi-energy power system is optimized through production simulation. Through simulation, it is verified that the method proposed in this paper can improve the efficiency of renewable energy power generation to a certain extent, and has a certain significance for promoting the transformation of energy production and consumption.
Numerical Simulation of Oil-Water Two-phase Conductivity in Hydraulic Fracturing Considering Proppant Crushing
Authors: Chen Shitong , Wang Jinlei , Yang Yongfei
Published: May 2023

Hydraulic fracturing can effectively increase reservoir productivity, and the effect depends on proppant behavior. Crushing of proppant during fracturing induces a series of changes in fracture width and the pore space formed between proppant particles, affecting reservoir fluid flow. For exploring the flow law of oil and water in proppant fractures, the discrete element method (DEM) and Tavares crushing model were combined to simulate the proppant crush process. At the same time, based on the formed pore space, the flow law of two phase fluid under the influence of such factors as the number of proppant placement, combination of particle size, closing pressure, and particle wettability was studied by fluid volume method(VOF). A series of data obtained through simulation show that with the increase of the average particle radius of single-layer and multilayer proppant is, the fracture conductivity and fracture width increase at the same closure pressure,. In the pore space formed by surface water-wet proppant, the ability of pore to transport oil phase increases; the higher of the number of closure pressure is, the larger the ability of pore to transport oil phase is.
Capacity Credit Variations of Photovoltaic Power Generation During its Life Cycle
Authors: Xu Zhicheng , Liu Huihong , Lu Gang
Published: May 2023

At present, the evaluation results of capacity credit of photovoltaic (PV) power generation are mainly static fixed values that are independent of time. Considering the degradation of the performance of the PV module, the capacity credit should be a time-varying value rather than a static value during the life cycle of the PV power plant. In this paper, the annual performance degradation model of a PV power station is established, and the time-varying capacity credit in the life cycle of the PV plant is simulated by calculating the year-by-year capacity credit. By adding a 100MW PV system to the IEEE-RTS 79 system for a case study, the results are as follows: the PV capacity credit is 46.04% without considering module performance decay, 45.36% in the first year when degradation is considered, and only 31.96% at the end of the life cycle. The average capacity credit over the life cycle is about 38.38%. It shows that the capacity credit varies greatly during the life cycle of PV modules, and cannot be ignored in the evaluation of capacity credit.
Study on flow loss mechanism in a supercritical fluid radial inflow turbine nozzle
Authors: Duan Siyu , Wang Zhongwei , Niu Yaobin , Miao Heyang
Published: May 2023

This paper uses ANSYS-CFX to simulate a 100kW supercritical CO2 radial inflow turbine. The internal vortex structure of the nozzle is identified based on Q-criterion and helicity. The internal flow loss of the nozzle is quantified based on Kock-Herwig’s theory of entropy production. Finally, the mechanism of internal loss formation in the nozzle is analyzed by combining the distribution law of entropy production. The analysis of the internal flow loss of the nozzle shows that the flow loss inside the supercritical CO2 radial inflow turbine nozzle is mainly caused by turbulent dissipation, and the turbulent pulsation induced by viscous shear stress plays a dominant role in this process.
Low Carbon Operation Strategy for Microgrids with Distributed Compressed Air Energy Storage
Authors: Yin Jun , Du Xili , Di Yanqiang , Chen Xiaotao , Chen Laijun
Published: May 2023

To improve the operation economy of the microgrid in a complex environment, a low-carbon operation strategy of microgrid with distributed compressed air energy storage is proposed. Firstly, considering the complex environment of regional microgrids, the coupling structure of distributed compressed air energy storage systems and microgrids is proposed. The new energy output and compressed air energy storage system model are established. On this basis, considering the consumption of new energy, a low-carbon operation strategy of the microgrid is constructed to improve the consumption level of new energy in the microgrid. Finally, the feasibility and competitiveness of the proposed low-carbon operation scheme are verified by simulation. The results show that the operation strategy of a low-carbon microgrid with distributed compressed air energy storage can reduce the operation cost by 57.3 %, and the new energy consumption rate can reach 97.2 %. The research results provide a theoretical basis and decision-making reference for applying distributed compressed air energy storage systems in complex environments.
A review of key issues in planning AC/DC distribution systems for renewable energy
Authors: Wang Wei , Wang Yanbo , Wang Dawei , Zou Yajun , Chen Xinhe
Published: May 2023

New requirements have been put forward for the construction of an AC/DC power distribution system under the targets of carbon peaking and carbon neutrality. It is urgent to build a new AC/DC power distribution system featuring low carbonization to realize the coordinated, green development of a high proportion of renewable energy. The low carbonization of the power industry is the key to coping with global warming and realizing the sustainable development of China’s society and economy. The reasonable and effective system planning and operation method will be the powerful means to ensure the AC/DC distribution system attain efficient carbon emission reduction under the premise of safe and stable operation. This paper combines the connotation and characteristics of renewable energy interconnection and mutual benefit, analyses the key technology features of AC/DC distribution systems for renewable energy, establishes a complete overall research framework of key technology for planning and operation of AC/DC distribution systems for renewable energy from two aspects of system planning and system operation, and gives an overview and outlook on each key research direction.
Simulation Study on the Effect of Different Fin Spacing on Heat Transfer in Microcolumn Radiator
Authors: Qu Qifeng , Zhu Hongwei , Sun Huan , Xu Haorong
Published: May 2023

In this paper, the heat transfer of microcolumn radiators with different spacing and arrangement was studied. Under the condition of constant heat flux qw
, linear arrangement (LA) and cross arrangement (CA) were used to simulate the heat transfer of 10 fin spacing under different mass flow rates. The results show that Nusselt Nu and fin heat transfer coefficient hfin
reduce with the increase of the transverse spacing and reduce with the increase of the vertical spacing. The Nusselt Nu and fin heat transfer coefficient hfin
with the reduction of the fin spacing, and the changing trend does not change with the change of heat flux qw.
A Transformer Condition Identification Model under Crossing Measuring Points Sampling
Authors: Gan Tuanjie , Huang Lianghao , Zhang Haomin
Published: May 2023

Due to the difference in sampling data distribution among different measuring points, the common transformer condition identification method of vibration analysis combined with machine learning has decreased accuracy. This work proposes a non-deep transformer condition identification model based on domain adaptation to solve it. Firstly, multi-scale feature extraction of vibration data is fulfilled by variational mode decomposition and time-frequency analysis. Then, manifold embedding method is employed to adapt source and target domains, which are sampled from different measuring points of transformer. The experimental results manifest that the presented approach could improve the accuracy of the transformer condition identification to a certain extent.
Research on Power Outage Sensing Technology of Medium and Low Voltage Distribution Network Based on Deep Learning of Multi-source Data Fusion
Authors: Luo Cheng , Qi Zhenbiao , Zhou Yuanke , Wu Kai , Feng Yu , Bian Hairui , Wang Bin
Published: May 2023

Aiming at the application of multi-source data fusion in intelligent operations of medium and low voltage distribution network system, a deep learning algorithm based on multi-source data fusion is proposed in this paper. Firstly, combining the stop/restart signals of a large number of users’ digital devices with the existing measurement information of the grid, two indicators of heartbeat and handshake signals have been constructed. Secondly, the convolutional neural network is combined with the improved D-S evidence theory, and an improved depth learning algorithm is proposed. Finally, taking a community as an example, the proposed algorithm is applied in practice and analyzed by simulation. The test results show that the model has good convergence and robustness. It is more intuitive and comprehensive in power failure evaluation. It has a wide power failure perception range and high accuracy and improves the quality of power supply service.
Implementation of Automatic DSP Code Generation Based on Closed-loop Algorithm for Three-level Inverters
Authors: Zhang Yu , Zhang Yong , Zhang Yongming
Published: May 2023

Wind energy has the advantages of wide distribution, renewable, and non-polluting, so it is receiving more and more attention from more and more countries. As more and more wind power systems are integrated into the grid, it has an impact on the stability of the grid. To keep the power system stable, there is an urgent need for a grid simulator that can simulate various behaviors of the grid and test the reliability of the wind turbine before grid integration. Inverters, especially multilevel inverters, as the core part of the grid simulator, have been widely studied by scholars in recent years. However, compared to conventional inverters, multilevel inverters are characterized by high code development effort, great difficulty, and a long development period. In this paper, we adopt an automatic DSP code generation method with MATLAB hardware support package and give a complete system design method and development flow based on MATLAB and TMSF28335 automatic code generation. Finally, we take the closed-loop three-level MMC inverter as an example, propose an equalization algorithm suitable for automatic code generation for the capacitor-voltage balancing part, and verify the feasibility of the DSP automatic code generation in a multilevel inverter development. The feasibility of DSP automatic code generation in the development of a multilevel inverter is verified. The experimental results show that the proposed equalization algorithm with variable reference coefficient and DSP automatic code generation method can be used in the development of a multilevel inverter, which can improve development efficiency and reduce development costs.
Influence of vehicular emissions and meteorological factors towards anionic surfactants in the urban atmospheric aerosol of Kuala Lumpur, Malaysia
Authors: Nor M A M , Wahid N B A , Ramli S , Hamid N Z A , Mohamad N , Latif M T
Published: May 2023

This study aimed to determine the influence of vehicular emissions and meteorological factors on the level of surfactants in urban atmospheric aerosol from Kuala Lumpur city center, Malaysia. Aerosol samples were collected using a high-volume sampler equipped with the cascade impactor to separate fine mode (< 1.5 µm) and coarse mode (> 1.5 µm) particles. Besides, the exhaust particulate matter from various diesel and petrol vehicles was collected using a soft brush during dry weather. Colorimetric analysis was performed to determine the concentration of anionic surfactants as methylene blue active substances (MBAS), and the absorption was determined by using a UV spectrophotometer at a wavelength of 650 nm. Correlation analysis was conducted to determine the influence of vehicular emissions (NOx, SO2, CO and O3), and exhaust particulate matter on the level of surfactants. Results showed that surfactants as MBAS in fine particles showed the dominant values. Correlation analysis showed that the MBAS was positively correlated with NOx (p <0.05) and SO2 (p <0.01), and negatively correlated with O3 (p <0.01), which indicated that the traffic-related air pollutant may influence the anionic surfactants level. It is supported by the high level of MBAS in diesel exhaust particulate matter, particularly from the construction machinery, followed by lorries and buses.
Investigation of open cluster NGC 7789 using GAIA EDR3 data
Authors: Tucio P B , Guido R M D , Kalaw J B
Published: May 2023

We present the membership determination of the NGC 7789 open cluster located at Cassiopeia. Based on the astrometric data from Gaia Early Data Release 3 (positions, parallaxes, and proper motions) are considered to derive cluster members of the open cluster. The Hierarchical Density-Based Spatial Clustering of Applications with Noise and Gaussian Mixture Model techniques in determining the frequency and degree of a star’s membership in a cluster were being utilized in the study. We calculate the parallax and distance of the NGC 7789 cluster center to be 0.1994 ± 0.11 mas and 18637 ± 333110 pc respectively. The cluster center is calculated to be α = 359° 16' 56.44'', δ = 56° 42''38.46 ' and proper motion to be µα = −1.386 ± 0.68 mas/yr and µδ = −1.052 ± 0.37 mas/yr. We also utilized the Automated Stellar Cluster Analysis tool and obtained: log(age) = ~9.20, distance modulus (m-M)v =0.6516, reddening E(B V)=0.26±0.28, and metallicity [Fe/H] = −0.26, respectively. The stars in NGC 7789 show very little movement on proper motion and might be caused by fainter observations.
Spatial temporal pattern of carbon dioxide emission from vehicle
Authors: Yaacob N F F , Mat Yazid M R , Abdul Maulud K N , Abdul Basri N E
Published: May 2023

Carbon dioxide (CO2) emission is a global environmental issue, and it is considered as triggered climate change. One of source contribute to CO2 emission is transportation sector which are increasing at a much faster rate than Gross Domestic Product growth. This paper present to evaluate spatial temporal pattern of CO2 emissions from vehicle using satellite Sentinel 5P image. The Sentinel 5P image was obtained from European Space Agency from year 2019 until 2021. These data were processed through ArcGIS software 10.5 to extract value of CO2 and the value are presented in total column amount. Subsequently, extract by point method on road feature based on basemap of Mukim Kajang was carried out to obtained value of CO2 emission from transportation. Then, spatial temporal mapping was achieved through kernel density analysis, which can be used to identify the CO2 emission hotspot areas. The result show spatial temporal pattern of CO2 emission was higher in September 2019 (0.06964 mol/m2), March 2020 (0.03596 mol/m2) and December 2021 (0.0437 mol/m2) respectively. Among the three highest vehicle-related CO2 emission hotspots in Mukim Kajang, high-emission literally covered the entire Bandar Kajang, whereas Bandar Baru Bangi and Bandar Serdang had decrease emission for the three (3) consecutive years. In the nutshell, the output of this study should be able to aid the local authority such as Federal Ministry of Environment in decision-making wise especially in developing related strategies to reduce CO2 emissions.
Identifying cluster members of NGC 869 and NGC 884 using a combined machine learning method
Authors: Guido R M D , Tucio P B , Kalaw J B. , Geraldo L E
Published: May 2023

This work describes a method for calculating cluster membership probability from big, high dimensional newly released GAIA-EDR3 observations that combine the Gaussian Mixture Model (GMM) with the Random Forest (RF). This technique has the considerable advantage of rapidly identifying possible cluster members in big data sets using modest training samples. The result indicates that the double clusters NGC 869 has 20270 points ultra-high (p≥ 0.8) probable members, 9294 are high (p≥ 0.6) probable members, and 6181 stars are moderate (0.2 <= p < 0.6) members. NGC 884 has ultra-high (p≥ 0.8) probable members of 21317, high (p≥ 0.6) probable members with 10871 and moderate (0.2 <= p < 0.6) of 5998. Cluster centers of NGC 884 and NGC 869 were also determined to be at α = 2h 22m 17s, δ = 57h 8m 60s and α = 2h 19m 2s, δ = 57h 7m 48s respectively. The double cluster also has a mean proper motion of -0.690 ± 12 mas/yr, or -1.150 ± 16 mas/yr, and a mean parallax of 0.410 ± 04 mas. The old cluster member in NGC 884 was quantified to be ± 621, and the new cluster member to be ± 1129. The new members of NGC 869 are ± 1511, up from the previous 920 members. We also found that the combined GMM and RF are effective in identifying cluster membership using the GAIA-EDR3 observations.
The comparison of relationship between climate variables and rice productivity in the clustering area on Java Island, Indonesia
Authors: Aprilina K , Sopaheluwakan A , Susandi A , Hadi T W , Trilaksono N J , Lubis A , Dayantolis W , Permana D S , Nuryanto D E , Anggraeni R , Komalasari K E , Fajariana Y , Yuliyanti M S , Haryoko U , Hidayanto N , Linarka U A
Published: May 2023

This study aims to compare the relationship between climate variables and rice productivity under different irrigation systems (irrigated and rainfed) in the clustering area on Java Island, Indonesia. This study used the clustering areas resulting from the previous study. The climate variables used are bias-corrected MERRA2 data from the period 1987–2017, cropped for Java Island. The rice productivity and reference evapotranspiration data used in this study are the results of the simulation of Aquacrop modeling. The result from the cluster method used tends to divide Java Island into 2 clusters with different altitudes (lowland and highland) areas. The results show that the correlation values between the precipitation variable and rice productivity from Aquacrop simulation (both irrigated or rainfed) in cluster 1 (dominated lowlands) are higher than in cluster 2 (dominated highlands), contrary to that the correlation values between the reference evapotranspiration variable with rice productivity from Aquacrop simulation (both irrigated or rainfed) are higher in cluster 2 (dominated highlands) areas, compared to cluster 1 areas (dominated lowlands). R-square values from response surface methodology (RSM) on the rainfed system in both clusters are higher than those on the irrigated system. This indicates that rainfed agriculture is highly dependent on climate variables, especially precipitation and reference evapotranspiration variables compared with the regular irrigated agricultural system. The RSM result also shows that climate variables significantly contribute to the variation of rice productivity generated by Aquacrop modeling in irrigated and rainfed systems and in all clusters.
Psychological Effects of Arbuscular Mychorrhiza Fungi Reducing Chemical Fertilizer on The Growth of Oil Palm Seedling
Authors: Mohd Nizar K , Tan C C , Elya Masya M F
Published: May 2023

Arbuscular mycorrhizal fungi (AMF) are fungi that form a symbiotic relationship with plant roots, supplying nutrients such as phosphorus. AMF can absorb, accumulate, and transport large amounts of phosphate in their hyphae before releasing it to plant cells in root tissues. The purpose of this research is to assess the feasibility of using AMF to reduce fertiliser levels in oil palm seedlings. Plant growth, foliar and rachis status, gas exchange, soil physiochemical, and spore count are among the parameters measured and analysed. Treatments were arranged in a randomized completed block design (RCBD) with 10 replications in four blocks. The finding showed that reducing Tekam Organic Fertilizer (TOF) and Nitrogen Phosphorus Potassium fertiliser rates by 15% with AMF could have an effect on plant growth differences (height, number of leaves, girth size, chlorophyll and leaf area)Total biomass, leaf weight ratio (LWR), and root-shoot ratio all have had significant relationships with growth performance. Furthermore, a significant correlation was found between net photosynthesis and stomatal conductance For plant growth data (palm height, number of leaves, and leaves area (LA) and root biomass of oil palm seedlings, the use of AMF has the potential to reduce the use of Tekam Organic Fertilizer (TOF) and Nitrogen Phosphate Potassium (NPK) fertilisers by 15%. The soil analysis results confirmed that the application increases plant growth, which increases availability.
Quantification of environmental impact potentials within the processes of industrial wastewater treatment system
Authors: Hijrah N , Syakir M I , Syah B I
Published: May 2023

New innovative management system of industrial wastewater is vital to address the current water demands, energy generation, resource conservation, and mitigating environmental impact from the wastewater treatment processes. For these reasons, the impact assessment of industrial wastewater treatment plant is imperative. Here, we quantified the environmental impact potentials within the processes in the wastewater treatment system considering the life cycle perspective. The treatment system comprises chemical and biological phases. The findings showed that hazardous waste (53.4%) appears as the major contributor of the impact potentials, followed by chemical consumption (38.3%), and electricity (7.5%). Other elements such as activated carbon (0.5%), cationic resin (0.2%), anionic resin (0.03%), and enzymes (0.009%) are relatively smalls in terms of the impact. The reuse of hazardous waste for heat recovery system is one of the initiatives to reduce the impact from hazardous waste generation by 12.2% for 1 m3 of treated water. This assessment may serve as a snapshot on the life cycle perspective of industrial wastewater management system in line with circular economy model that emphasizes rethink, reduce, reuse, and recovery efforts in industrial wastewater treatment management systems.