Saad Waqar, Jiangwei Liu, Qidong Sun, Kai Guo and Jie Sun
This paper aims to investigate the influence of different post-annealing cooling conditions, i.e. furnace cooling (heat treatment (HT) 1 – slow cooling) and air cooling (HT 2 �…
Abstract
Purpose
This paper aims to investigate the influence of different post-annealing cooling conditions, i.e. furnace cooling (heat treatment (HT) 1 – slow cooling) and air cooling (HT 2 – fast cooling), on the microstructure and mechanical properties of selective laser melting (SLM) built austenitic 316L stainless steel (SS).
Design/methodology/approach
Three sets of 316L SS samples were fabricated using a machine standard scanning strategy. Each set consists of three tensile samples and a cubic sample for microstructural investigations. Two sets were subsequently subjected to annealing HT with different cooling conditions, i.e. HT 1 and HT 2, whereas one set was used in the as-built (AB) condition. The standard metallographic techniques of X-ray diffraction, scanning electron microscopy and electron back-scattered diffraction were used to investigate the microstructural variations induced by different cooling conditions. The resultant changes in mechanical properties were also investigated.
Findings
The phase change of SLM fabricated 316L was observed to be independent of the investigated cooling conditions and all samples consist of austenite phase only. Both HT 1 and HT 2 lead to dissolved characteristic melt pools of SLM. Noticeable increase in grain size of HT 1 and HT 2 samples was also observed. Compared with AB samples, the grain size of HT 1 and HT 2 was increased by 12.5% and 50%, respectively. A decreased hardness and strength, along with an increased ductility was also observed for HT 2 samples compared with HT 1 and AB samples.
Originality/value
From previous studies, it has been noticed that most investigations on HT of SLM fabricated 316L were mainly focused on the HT temperature or holding time. However, the post-HT cooling rate is also an equally important factor in deciding the microstructure and mechanical properties of heat-treated components. Therefore, this paper investigates the influence of different post-annealing cooling conditions on microstructure and mechanical properties of SLM fabricated 316L components. This study provides a foundation for considering the post-HT cooling rate as an influential parameter that controls the properties of heat-treated SLM components.
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The rail transport sector in China represents one of the largest consumers of energy today, and the primary purpose of this paper is to examine the causes of changes in energy…
Abstract
Purpose
The rail transport sector in China represents one of the largest consumers of energy today, and the primary purpose of this paper is to examine the causes of changes in energy consumption of Chinese national rail transport (ECCNRT).
Design/methodology/approach
For this study, reasonable indicators as factors that affected conversion volume (CV) and unit energy consumption (UEC) based on statistical data from 1990 to 2010 were selected. CV and UEC models were established by regression analysis and tested using real data of 2011-2014. The CV model indicates it has an exponential relationship with GDP. Besides, there is a quantitative relationship between UEC and the quantity of locomotives. The ECCNRT calculation model was proposed and ECCNRT model data were compared with the real data. Impacts of different factors on ECCNRT were analyzed with economic principles.
Findings
The analysis conducted shows that the calculation model can reflect variation of ECCNRT precisely, and ECCNRT has a quantitative relation with GDP and quantities of locomotives. GDP accounts for changes of ECCNRT 20.02 per cent, while those for quantity of diesel locomotives and electric locomotives are 26.87 and 53.11 per cent, respectively. The number of electric locomotives is the main factor that influences variation of ECCNRT.
Originality/value
Through regression analysis, this study discovered the inner quantitative relationship between the conversion volume (important index of Chinese national rail transport production) and GDP. In addition, this study establishes the ECCNRT model according to the Chinese national rail transport data, which can be used to calculate the amount of ECCNRT and conduct quantitative analysis for different impacts of various factors on ECCNRT’s changes.
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Vikas Kumar, Bikramjit Singh Hundal and Kulwinder Kaur
The purpose of this paper is to identify the factors influencing farmers’ intention to purchase solar water pumping systems (SWPS).
Abstract
Purpose
The purpose of this paper is to identify the factors influencing farmers’ intention to purchase solar water pumping systems (SWPS).
Design/methodology/approach
The research is based on primary data that have been collected from a total of 345 solar pump users from different villages and rural areas of Punjab (India). Exploratory and confirmatory factor analysis and multiple regression analysis have been used to examine the collected data. Multiple regression analysis is used to examine the identified dimensions’ impact on customer buying behaviour.
Findings
The results of analysis validated that consumer buying behaviour is significantly determined by cost, performance and government initiatives dimensions. However, dimensions such as eco-friendly product, information regarding product and company, environmental concern and social influence were found insignificant.
Research limitations/implications
The sample size has been selected on the basis of convenience sampling and sample has been taken from the rural area. Therefore, the result may not be representative of the overall population. The perception of respondents from one part may vary from another part of India.
Originality/value
By providing an insight into factors affecting consumer buying behaviour of SWPS, the proposed research attempts to fill the gaps in literature by conducting an empirical study on consumer buying behaviour. As the study relates to SWPS users, findings will be of additional value to solar product companies and the government.
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Ruipan Lu, Zhangqi Liu, Xiping Liu, Baoyu Sun and Jiangwei Liang
To address the issues of the insufficient output torque associated with the application of intensifying-flux permanent magnet (PM) machines in electric vehicles, this paper aims…
Abstract
Purpose
To address the issues of the insufficient output torque associated with the application of intensifying-flux permanent magnet (PM) machines in electric vehicles, this paper aims to propose an intensifying-flux hybrid excitation PM machine. It is possible to adjust the air gap magnetic field by adjusting the field current in the excitation winding, thereby increasing the torque output capability and speed range of the machine.
Design/methodology/approach
First, a novel intensifying-flux hybrid excited permanent magnet synchronous machine (IF-HEPMSM) is proposed on the basis of intensifying-flux permanent magnet synchronous machine (IF-PMSM) and an equivalent magnetic circuit model is established. Second, the tooth width and yoke thickness of the machine stator are optimized to ensure the overload capacity of the machine while effectively improving the wide flux regulation range. Furthermore, the electromagnetic characteristics of the IF-HEPMSM are investigated and compared with the IF-PMSM and conventional permanent magnet synchronous machine (PMSM) by using finite element simulations.
Findings
The id of IF-HEPMSM and IF-PMSM is greater than zero low-speed magnetizing current. And the flux-weakening current of the IF-HEPMSM is 18% and 3% smaller than of the conventional PMSM and IF-PMSM.
Practical implications
Aiming at the problems of IF-PMSM applied to electric vehicles, this paper proposes an IF-HEPMSM. The air gap magnetic field is adjusted by controlling the current of the excitation winding to improve the reliability of the machine. Therefore, the IF-HEPMSM combines the advantages of high-power density and high efficiency of the PMSM and the controllable magnetic field of the electro-excitation machine, which is of great engineering value when applied in the field of electric vehicles.
Originality/value
The proposed IF-HEPMSM offers better flux regulation capability with electromagnetic characteristics analysis and maps of dq-axis current as compared to IF-PMSM and conventional PMSM. Moreover, the improvement of the torque can make up for the shortcomings of the insufficient torque output capability of the IF-PMSM.
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Dongwei Wang, Faqiang Li, Yang Zhao, Fanyu Wang and Wei Jiang
This paper aims to study the tribological characteristics of the electrical contact system under different displacement amplitudes.
Abstract
Purpose
This paper aims to study the tribological characteristics of the electrical contact system under different displacement amplitudes.
Design/methodology/approach
First, the risk frequency of real nuclear safety distributed control system (DCS) equipment is evaluated. Subsequently, a reciprocating friction test device which is characterized by a ball-on-flat configuration is established, and a series of current-carrying tribological tests are carried out at this risk frequency.
Findings
At risk frequency and larger displacement amplitude, the friction coefficient visibly rises. The reliability of the electrical contact system declines as amplitude increases. The wear morphology analysis shows that the wear rate increases significantly and the degree of interface wear intensifies at a larger amplitude. The wear area occupied by the third body layer increases sharply, and the appearance of plateaus on the surface leads to the increase of friction coefficient and contact resistance. EDS analysis suggests that oxygen elements progressively arise in the third layer as a result of increased air exposure brought on by larger displacement amplitude.
Originality/value
Results are significant for recognizing the tribological properties of electrical connectors in nuclear power control systems.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0098/
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Souhila Benomar, Sanaa Yahia, Faiza Dehiba, Natalia Guillen, Maria Jesús Rodriguez-Yoldi, Jesús Osada and Ahmed Boualga
– The purpose of this study was to evaluate the antioxidant and hypocholesterolemic activities of sardine and bogue protein hydrolysates in cholesterol-fed rats.
Abstract
Purpose
The purpose of this study was to evaluate the antioxidant and hypocholesterolemic activities of sardine and bogue protein hydrolysates in cholesterol-fed rats.
Design/methodology/approach
In total, 18 male Wistar rats (220 ± 10 g) fed 20 per cent casein, 1 per cent cholesterol and 0.5 per cent cholic acid were divided into three groups and received a daily gavage of 250 mg of sardine (SPH) or bogue (BPH) protein hydrolysates for 30 days. The third group, named control group (CG), received in the same conditions water. Lipoproteins were fractionated by size-exclusion fast protein liquid chromatography, and serum lipids, apolipoproteins and lipoproteins were assayed.
Findings
In SPH and BPH groups, serum total cholesterol concentrations were −66 per cent lower than in CG. This corresponded to the decreased very low-density lipoprotein-C in the former groups. Moreover, BPH treatment reduced low-density lipoprotein-C compared with CG and SPH groups. Compared with CG, serum phospholipids were reduced by SPH and BPH. Furthermore, BPH increased significantly APOA4 and sphingomyelin but lowered phosphatidylcholine. In the latter group, serum lecithin cholesterol acyltransferase activity was +23 per cent higher, but with SPH, this activity was −35 per cent reduced compared with CG. Apolipoprotein A-I contents were similar in the three groups. Compared with CG, hydroperoxide and lipid peroxidation contents in serum and lipoprotein fractions were reduced by SPH and BPH. Compared with CG, serum superoxide dismutase and glutathione peroxidase activities were increased in the treated groups, particularly in the BPH group.
Originality/value
These results suggest that sardine protein hydrolysates and particularly those of bogue could be a very useful natural compound to prevent hypercholesterolemia by both improving the lipid profile and modulating oxidative stress in cholesterol-fed rats.
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Ganesh P. Sahu, Pragati Singh and Prabhudatt Dwivedi
Adoption of solar energy plays an important role in the growth of a country. There are many factors which influence the adoption of solar energy in India. The study is designed to…
Abstract
Purpose
Adoption of solar energy plays an important role in the growth of a country. There are many factors which influence the adoption of solar energy in India. The study is designed to identify factors that determine the acceptance or rejection of solar energy systems in India.
Design/methodology/approach
Relationship among identified variables is established through interpretive structural modelling (ISM) and thus a conceptually validated model is evolved. Further, MICMAC analysis is conducted to understand the driving power and dependence of these variables.
Findings
It is revealed that experience and habit, awareness and social influence are the intermediary variables. MICMAC Analysis shows that no variable is disconnected from the system and all the variables influence the adoption of solar energy in India.
Practical implications
The present study is expected to be useful to decision makers, end users and research organisations related to solar energy adoption.
Originality/value
Various intentional factors influencing solar energy systems adoption have been acknowledged in the present study, thus making it useful for formulation of action plans and enhance the usage of solar energy systems to improve environment quality.