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This study aims to focus on the surface curvature, jet to target spacing and jet Reynolds number effects on the heat transfer and fluid flow characteristics of a slot jet impinging on a confined concave target surface at constant jet to target spacing.

Numerical simulations are used in this research. Jet to target spacing, H/B is varying from 1.0 to 2.2, B is the slot width. The jet Reynolds number, Rej, varies from 8,000 to 40,000, and the surface curvature, R2/B, varies from 4 to 20. Results of the target surface heat transfer, flow parameters and fluid flow in the concave channel are performed.

It is found that an obvious backflow occurs near the upper wall. Both the local and averaged Nusselt numbers considered in the defined region respond positively to the Rej. The surface curvature plays a positive role in increasing the averaged Nusselt number for smaller surface curvature (4-15) but affects little as the surface curvature is large enough (> 15). The thermal performance is larger for smaller surface curvature and changes little as the surface curvature is larger than 15. The jet to target spacing shows a negative effect in heat transfer enhancement and thermal performance.

The surface curvature effects are conducted by verifying the concave surface with constant jet size. The flow characteristics are first obtained for the confined impingement cases. Then confined and unconfined slot jet impingements are compared. An ineffective point for surface curvature effects on heat transfer and thermal performance is obtained.

The purpose of this paper is to draw on social capital theory to develop a model to explain the determinants of a supply chain management scholar’s academic research impact.

Drawing from a database of 450 supply chain management scholars in different countries collected from ResearchGate and the World Bank, the bootstrapping method was applied on the moderated mediation analysis.

Analysis of the mediating role of a scholar’s social capital suggests that social capital theory has a strong explanatory power on the relationship between a scholar’s research skill and academic impact. To account for the boundary effect at the country-level, the authors further examine if this mechanism differs by country in the supply chain management research context.

The findings from this study are from a single research area, which limits the generalizability of the study. Although the data are collected from different sources, including ResearchGate and the World Bank, it is cross-sectional in nature. The variables in this model do not have strong causal relationships.

The results suggest that supply chain management scholars can reap the benefits of their social capital. Specifically, scholars can enhance their academic impact by increasing their social capital.

The results provide a reference for supply chain management scholars keen on enhancing their academic research impact. It also provides a reference to explain why country-level differences can influence these scholars.

Optimized plating conditions, included proper designs of insulating shield (IS), auxiliary cathode (AC) and different patterns, contribute to the uniformity enhancement of copper deposition.

Plating experiments were implemented in vertical continuous plating (VCP) line for manufacturing in different conditions. Multiphysics coupling simulation was brought to investigate and predict the plating uniformity improvement of copper pattern. In addition, the numerical model was based on VCP to approach the practical application.

With disproportionate current distribution, different plating pattern design formed diverse copper thickness distribution (CTD). IS and AC improved plating uniformity of copper pattern because of current redistribution. Moreover, optimized plating condition for effectively depositing more uniformed plating copper layer in varied pattern designs were derived by simulation and verified by plating experiment.

The comparison between experiment and simulation revealed that multiphysics coupling is an efficient, reliable and of course environment-friendly tool to perform research on the uniformity of pattern plating in manufacturing.

The purpose of this paper is to develop a novel hybrid plasma deposition and milling (HPDM). For solving the bottleneck problem of low‐surface quality in existing direct rapid metal prototyping technologies.

HPDM uses plasma deposition as an additive and conventional milling as subtractive technique, which synthesizes the advantages of both processes. Compared to other laser or electron beam deposition processes, plasma deposition used in HPDM is one of the most economic ways of depositing metals, CNC assisted to ensure the precision of the manufactured parts simultaneity.

This paper focus on the experimental investigation to find the basic process characteristics, the optimization of the process parameters such as transferred arc current, workpiece's speed, powder flow rate and feed per tooth using a statistical approach. Some metal parts, for instance, metal torsional vane, are then trial‐manufactured.

The manufacturing cycle of HPDM is longer than simplex direct metal rapid prototyping, and the surface accuracy should be further investigated.

HPDM is a very useful and effective method to manufacture metal parts with fine surface state directly.

This paper describes a novel process and manufacturing system for fabrication metal prototyping direct, which can improve the inside and outside quality of the metal rapid prototypes.

This paper aims to present a sliding mode control method based on disturbance observer (DO) for improving the reaching law of permanent magnet synchronous motor (PMSM).

Aiming at the insufficiency of the traditional exponential reaching law used in sliding mode variable structure control, an exponential reaching law related to the speed error is proposed. The improved exponential reaching law can adaptively adjust the size of the constant velocity term in the reaching law according to the size of the speed error, so as to adaptively adjust the speed of the system approaching the sliding mode surface to overcome the control deviation and improve the dynamic and steady state performance. To improve the anti-interference ability of the system, a DO is proposed to observe the external disturbance of the system, and the observed value is used to compensate the system. The stability of the system is analyzed by Lyapunov theorem. The effectiveness of this method is proved by simulation and experiment.

Simulation and experiment show that the proposed method has the advantages of fast response and strong anti-interference ability.

The proposed method cannot observe the disturbance caused by the change of internal parameters of the system.

A sliding mode control method for PMSM is proposed, which has good control performance. The proposed method can effectively suppress chattering, ensure fast response speed and have strong anti-interference ability. The effectiveness of the algorithm is verified by simulation and experiment.

As an advanced manufacturing method, additive manufacturing (AM) technology provides new possibilities for efficient production and design of parts. However, with the continuous expansion of the application of AM materials, subtractive processing has become one of the necessary steps to improve the accuracy and performance of parts. In this paper, the processing process of AM materials is discussed in depth, and the surface integrity problem caused by it is discussed.

Firstly, we listed and analyzed the characterization parameters of metal surface integrity and its influence on the performance of parts and then introduced the application of integrated processing of metal adding and subtracting materials and the influence of different processing forms on the surface integrity of parts. The surface of the trial-cut material is detected and analyzed, and the surface of the integrated processing of adding and subtracting materials is compared with that of the pure processing of reducing materials, so that the corresponding conclusions are obtained.

In this process, we also found some surface integrity problems, such as knife marks, residual stress and thermal effects. These problems may have a potential negative impact on the performance of the final parts. In processing, we can try to use other integrated processing technologies of adding and subtracting materials, try to combine various integrated processing technologies of adding and subtracting materials, or consider exploring more efficient AM technology to improve processing efficiency. We can also consider adopting production process optimization measures to reduce the processing cost of adding and subtracting materials.

With the gradual improvement of the requirements for the surface quality of parts in the production process and the in-depth implementation of sustainable manufacturing, the demand for integrated processing of metal addition and subtraction materials is likely to continue to grow in the future. By deeply understanding and studying the problems of material reduction and surface integrity of AM materials, we can better meet the challenges in the manufacturing process and improve the quality and performance of parts. This research is very important for promoting the development of manufacturing technology and achieving success in practical application.

The purpose of this paper is to examine the impact of off-farm income on food expenditure, using survey data of 493 rural households from Gansu, Henan and Shandong provinces in China.

A two-stage least squares estimator is used to jointly estimate the determinants of off-farm income and the direct impact of off-farm income on food expenditure while controlling for the endogeneity issue associated with off-farm income variable.

The empirical results show that gender, education of household head, household size, farm size, the presence of children, smartphone use and asset ownership mainly determine off-farm income, and the off-farm income affects food expenditure of rural households significantly. In particular, the results show that a 1,000 yuan increase in per capita off-farm income increases per capita food expenditure by 61 yuan. Further estimations reveal that off-farm income has a larger effect on food expenditure of high-income rural households relative to their low-income counterparts.

Although poverty implications of off-farm income have been well documented, few studies have analysed the effects of off-farm income on food expenditure of rural households. To the best of the authors’ knowledge, there are no studies on this issue that focus on rural China. Therefore, the present study attempts to provide a first insight into the association between off-farm income and food expenditure of rural households in China, with the aim of providing useful evidence for policymakers in their efforts to reduce rural and urban food consumption gap and further increase social welfare.

The purpose of this paper is to review additive and/or subtractive manufacturing methods for metallic objects and their gradual evolution from prototyping tools to rapid manufacture of actual parts.

Various existing rapid manufacturing (RM) methods have been classified into six groups, namely, CNC machining laminated manufacturing, powder‐bed technologies, deposition technologies, hybrid technologies and rapid casting technologies and discussed in detail. The RM methods have been further classified, based on criteria such as material, raw material form, energy source, etc. The process capabilities springing from these classifications are captured in the form of a table, which acts as a database.

Due to the approximation in RM in exchange for total automation, a variety of multi‐faceted and hybrid approaches has to be adopted. This study helps in choosing the appropriate RM process among these myriad technologies.

This review facilitates identification of appropriate RM process for a given situation and sets the framework for design for RM.