Jun Qin, Shuxin Bai, Weijun Zhang, Zhuofeng Liu and Hailiang Wang
The purpose of this paper is to characterize and understand the effects of polymer binder, thixotropic agent, solvent and organic medium content on the rheological properties of…
Abstract
Purpose
The purpose of this paper is to characterize and understand the effects of polymer binder, thixotropic agent, solvent and organic medium content on the rheological properties of silver pastes for screen printing front electrode films of solar cells.
Design/methodology/approach
Dispersions of silver particles (surface modified with oleic acid) in ethyl cellulose (EC) polymer solutions with and without thixotropic agent were prepared, and yield stress values were measured by setting shear stress to characterize the inter-particle interaction strength of pastes. Steady-state flow, three interval thixotropy shear test and oscillatory measurements were conducted to study the effect of EC polymer and thixotropic agent on viscosity, structure rebuilding and viscoelastic properties of electrode pastes. The effect of solvent was studied by investigating the steady viscosity of cellulose acetate butyrate (CAB) polymer solutions and Ag dispersions.
Findings
Weak flocculation network of silver particles was produced because of depletion flocculation. Besides the interaction between thixotropic agent micelles, EC polymer also has a significant interaction with thixotropic agent. Merely increasing EC polymer or thixotropic agent content is not the best way to prevent the layer printed from laying down. The effect of solvent on the viscosity of paste is mainly attributed to the difference of hydromechanics radius and configuration of CAB polymer in solvents. With the increase of organic medium content, the properties of electrode pastes were converted from rigidity to flexibility.
Originality/value
It is still a challenge to obtain high-quality front electrode films for crystalline silicon solar cells by screen printing, because of the difficulty in reducing shadowing losses while ensuring a low series resistance and high filling factor. The paste rheological properties are the key properties related to the paste’s passing ability through the meshes and resistance of paste spreading on the substrate. Organic medium as an important component of the paste is acknowledged to be used to tailor the paste’s rheological properties and have a great role in screen printing.
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Thi Kieu Van Tran, Ehsan Elahi, Liqin Zhang, Van Huyen Bui, Quang Trung Pham, Thuy Duong Tran, Thi Lien Ta and Munawar Hassan
The purpose of this paper is to investigate the determinants of the gender gap in the gross value of rice yield in Vietnam.
Abstract
Purpose
The purpose of this paper is to investigate the determinants of the gender gap in the gross value of rice yield in Vietnam.
Design/methodology/approach
A panel data set of 12 provinces of Vietnam from 2010 to 2014 was used, collected from the Vietnam access to resources household survey. To measure the gender gap in the gross value of rice yield, two-stage least squares and Blinder – Oaxaca decomposition methods were used.
Findings
The gross value of rice productivity of male-headed households was 10.3 percent higher than that of female-headed households. The gender gap in rice productivity is caused by the endowment and structural effects; the endowment effect explained 53 percent of the gender gap in rice productivity and the structural effect 42 percent.
Practical implications
In order to reduce the gender gap and improve the gross value of rice yield, the following policies are suggested: female education and access to institutional services (extension and credit) should be improved and future research is needed to determine the reasons for gender discrimination in the agricultural production system.
Originality/value
The findings suggest that the difference in the gross value of rice yield between male- and female-headed households were mainly caused by endowments and returns from those endowments.
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Jane K. Giacobbe‐Miller, Daniel J. Miller and Weijun Zhang
Involves a role‐play in which Chinese and US managers allocate a hypothetical bonus to a work group. Indicates that Chinese managers employed three distributive rules (i.e…
Abstract
Involves a role‐play in which Chinese and US managers allocate a hypothetical bonus to a work group. Indicates that Chinese managers employed three distributive rules (i.e. equity, equality and need) placing greatest emphasis on equality. In contrast, US managers employed two distributive rules, equity and equality, placing the greatest emphasis on equity. Chinese managers placed significantly greater emphasis on the need rule than did US managers, although very small amounts were allocated on the basis of need. Discusses implications for appropriate pay design.
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Huibin Sun, Zhiyong Chang and Rong Mo
The purpose of this paper is to solve the asynchrony problem between the logistics stream and the information stream in the complex product assembly executive process.
Abstract
Purpose
The purpose of this paper is to solve the asynchrony problem between the logistics stream and the information stream in the complex product assembly executive process.
Design/methodology/approach
States of assembly and logistics are described by transitions, and implemented via logistics agents and assembly agents. Events in the assembly executive process are described by places, and mapped to radio frequency identification (RFID) tags' states. An agent‐based complex product assembly framework is proposed. Mobile agents are used to encapsulate task and data, and RFID tags' states are able to trigger dispatching of assembly agents and executing of assembly tasks. Assisted by mobile agents' retraction mechanism, on‐site data are carried back when assembly tasks are finished.
Findings
An assembly executive process Petri net and a mobile agent‐based complex product assembly framework are proposed.
Originality/value
Dynamic matching mechanism between assembly tasks and materials is achieved, and controlling and monitoring methods of complex product assembly executive process are enhanced.
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Melaku Abegaz and Hossein Eftekari
This paper examines the gender achievement gap in the Ethiopian secondary education system using tenth-grade national examination results for the period 2002/03–2013/14.
Abstract
Purpose
This paper examines the gender achievement gap in the Ethiopian secondary education system using tenth-grade national examination results for the period 2002/03–2013/14.
Design/methodology/approach
Statistical tests are employed to determine equality of the average male and female GPAs (grade point average), and equality of the proportions of female and male test-takers in the upper and lower achievement distributions. Further, a panel fixed effects model is used to evaluate factors that affect the regional average GPAs by gender and to determine whether those factors could explain observed gender achievement gaps.
Findings
Results indicate statistically significant gender achievement gaps in all regional states and the capital city. The gap has been persistent with a minor declining trend and will not be closed if continued at the current trend. The authors also find that the regional average male and female test scores could be explained partially by factors such as pupil-teacher ratio, the proportion of rural students and access to secondary schools. These factors, however, cannot explain the observed gender achievement gap.
Originality/value
The study uses regional data collected from the annual educational abstracts published by the Ethiopian ministry of education. It investigates the trends of the gender achievement gaps across the regional states and overtime at the tenth-grade level. It depicts the persistence of the gap hindering girls from furthering their education.
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Yingjie Ju, Hanping Hou and Jianliang Yang
Using the logistics service supply chain (LSSC) as a research object, this study focuses on the relationship between integration quality (IQ), value co-creation (VCC), and LSSC…
Abstract
Purpose
Using the logistics service supply chain (LSSC) as a research object, this study focuses on the relationship between integration quality (IQ), value co-creation (VCC), and LSSC resilience. Moreover, it discusses the moderating role of digital technology (DT).
Design/methodology/approach
Based on data about China, this study used the structural equation model to test the research hypothesis. To verify the validity of each construct, this study used various established scales in the literature to conduct exploratory and confirmatory analysis.
Findings
The results show that IQ is an essential antecedent variable that promotes VCC and LSSC resilience. Moreover, this study confirms that DT has a positive moderating effect on the relationship between IQ, VCC, and resilience.
Originality/value
This study constructs a research framework to examine LSSC resilience and expands the theoretical research on the VCC theory in the supply chain literature. Moreover, this paper studies supply chain integration from a new perspective, that is, IQ, which is more in line with the reality of LSSC.
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Anxia Wan, Qianqian Huang, Ehsan Elahi and Benhong Peng
The study focuses on drug safety regulation capture, reveals the inner mechanism and evolutionary characteristics of drug safety regulation capture and provides suggestions for…
Abstract
Purpose
The study focuses on drug safety regulation capture, reveals the inner mechanism and evolutionary characteristics of drug safety regulation capture and provides suggestions for effective regulation by pharmacovigilance.
Design/methodology/approach
The article introduces prospect theory into the game strategy analysis of drug safety events, constructs a benefit perception matrix based on psychological perception and analyzes the risk selection strategies and constraints on stable outcomes for both drug companies and drug regulatory authorities. Moreover, simulation was used to analyze the choice of results of different parameters on the game strategy.
Findings
The results found that the system does not have a stable equilibrium strategy under the role of cognitive psychology. The risk transfer coefficient, penalty cost, risk loss, regulatory benefit, regulatory success probability and risk discount coefficient directly acted in the direction of system evolution toward the system stable strategy. There is a critical effect on the behavioral strategies of drug manufacturers and drug supervisors, which exceeds a certain intensity before the behavioral strategies in repeated games tend to stabilize.
Originality/value
In this article, the authors constructed the perceived benefit matrix through the prospect value function to analyze the behavioral evolution game strategies of drug companies and FDA in the regulatory process, and to evaluate the evolution law of each factor.
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Qiqi Zhang, Weijun Zhen, Quansheng Ou, Yusufu Abulajiang and Gangshan Ma
The objective was to investigate the utility of cottonseed oil (CSO) as a raw material for the synthesis of CSO water-based alkyd resin. The synthesis involved the polymerization…
Abstract
Purpose
The objective was to investigate the utility of cottonseed oil (CSO) as a raw material for the synthesis of CSO water-based alkyd resin. The synthesis involved the polymerization of CSO, trimethylolpropane, phthalic anhydride (PA) and trimellitic anhydride (TMA). The prepared resin coating material was subsequently applied to the surface of steel structure material.
Design/methodology/approach
This study aimed to synthesize water-based alkyd resins using CSO. Therefore, the alkyd resin was introduced with TMA containing carboxyl groups and neutralized with triethylamine (TEA) to form a water-soluble salt. Then, the esterification kinetics of CSO water-based alkyd resin were investigated, and finally, the basic properties of CSO water-based alkyd resin coating were evaluated.
Findings
It was demonstrated that CSO water-based alkyd resin exhibited excellent water solubility and that the esterification kinetic of the synthesis reaction could be described by a second-order reaction. The coating properties of the material were investigated and found to have good basic properties, with 40% resin addition having the best corrosion resistance. Consequently, it could be effectively applied to the surface of steel structural materials.
Originality/value
This study not only met the requirement of environmentally friendly development but also expanded the application of CSO through the synthesis of CSO water-based alkyd resin via alcoholysis. Compared to fatty acid process, the alcoholysis reduced the need for fatty acid pre-extraction, simplifying the alkyd resin synthesis process. Thus, economic costs are effectively reduced.
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Ming-Hui Liu, Jianbin Xiong, Chun-Lin Li, Weijun Sun, Qinghua Zhang and Yuyu Zhang
The diagnosis and prediction methods used for estimating the health conditions of the bearing are of great significance in modern petrochemical industries. This paper aims to…
Abstract
Purpose
The diagnosis and prediction methods used for estimating the health conditions of the bearing are of great significance in modern petrochemical industries. This paper aims to discuss the accuracy and stability of improved empirical mode decomposition (EMD) algorithm in bearing fault diagnosis.
Design/methodology/approach
This paper adopts the improved adaptive complementary ensemble empirical mode decomposition (ICEEMD) to process the nonlinear and nonstationary signals. Two data sets including a multistage centrifugal fan data set from the laboratory and a motor bearing data set from the Case Western Reserve University are used to perform experiments. Furthermore, the proposed fault diagnosis method, combined with intelligent methods, is evaluated by using two data sets. The proposed method achieved accuracies of 99.62% and 99.17%. Through the experiment of two data, it can be seen that the proposed algorithm has excellent performance in the accuracy and stability of diagnosis.
Findings
According to the review papers, as one of the effective decomposition methods to deal with nonlinear nonstationary signals, the method based on EMD has been widely used in bearing fault diagnosis. However, EMD is often used to figure out the nonlinear nonstationarity of fault data, but the traditional EMD is prone to modal confusion, and the white noise in signal reconstruction is difficult to eliminate.
Research limitations/implications
In this paper only the top three optimal intrinsic mode functions (IMFs) are selected, but IMFs with less correlation cannot completely deny their value. Considering the actual working conditions of petrochemical units, the feasibility of this method in compound fault diagnosis needs to be studied.
Originality/value
Different from traditional methods, ICEEMD not only does not need human intervention and setting but also improves the extraction efficiency of feature information. Then, it is combined with a data-driven approach to complete the data preprocessing, and further carries out the fault identification and classification with the optimized convolutional neural network.
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Lingcheng Kong, Ling Liang, Jianhong Xu, Weisi Zhang and Weijun Zhu
Although the wind power industry has been booming in China during the last decade, the development of wind turbine aftermarket service is still lagging behind, which seriously…
Abstract
Purpose
Although the wind power industry has been booming in China during the last decade, the development of wind turbine aftermarket service is still lagging behind, which seriously affects the operational efficiency of wind farms. If wind turbine manufacturers get involved in the aftermarket, the service pricing policy will impact the profits of both the manufacturer and the wind farm. Therefore, it is necessary to discuss an optimal service pricing strategy in the wind turbine aftermarket and design a method to improve electricity generation efficiency through service contract design. The paper aims to discuss these issues.
Design/methodology/approach
In order to decide the maintenance quantity and channel effort level, the authors design a normal Stackelberg game and an efficiency value-added revenue-sharing contract and discuss two kinds of revenue increment sharing models under situations, in which the supply chain’s leaders are the wind farm and the wind turbine manufacturer, respectively.
Findings
The results show that in either case, there exist optimal power generation revenue-sharing ratios that can maximize profit. At the same time, the authors outline an optimal service pricing policy, maintenance demand policy and channel service effort-level policy. The results summarize the influences of wind aftermarket services on wind farms’ and wind turbine manufacturers’ profit, which provides managerial insights into the process of manufacturing servitization.
Practical implications
The manufacturer’s channel effort level will influence the power generation increments very much, so the authors have developed a mechanism to stimulate the manufacturer improving the efficiency of aftermarket services.
Originality/value
Taking the power generation increment revenue as the profit increment function, the authors discuss the influence of service price on the profit increment of the wind farm and the wind turbine manufacturer and also consider the influence of service price on the wind farms maintenance quantity and wind turbine manufacturers channel effort level.