Bo Li, Bo Yuan, Shuai Tang, Yuwen Mao, Dongmei Zhang, Changyun Huang and Bilian Tan
This paper aims to investigate weight-climbing assistance strategy for the biomechanical design of passive knee-assisting exoskeleton (PKAExo) and evaluate a designed PKAExo which…
Abstract
Purpose
This paper aims to investigate weight-climbing assistance strategy for the biomechanical design of passive knee-assisting exoskeleton (PKAExo) and evaluate a designed PKAExo which stores energy when the knee joint flexes and releases the energy to assist ascending when the knee joint extends.
Design/methodology/approach
The authors constructed theoretic modeling of human weight-climbing to analyze characteristics of knee angle and moment. They then conducted camera-based movement analysis, muscle strength and endurance tests and surface electromyography (sEMG) measures to verify the relationship of knee angle and moment with both stair height and load weight. Afterwards, the authors proposed an assistant strategy for passive knee assistance, then gave out designed PKAExo and conducted mechanical experiment to test the knee-assisting torque. Finally, the authors conducted comparison experiment based on measuring the sEMG signals of knee extensor to verify the assistance effect of the PKAExo for weight-climbing.
Findings
The knee extensor produces the maximum force during weight-climbing, and the muscle force provided by knee extensor has significant increasing rate along with the stair height. Thus, the assistance torque of PKAExo is designed to increase nonlinearly along with increasing knee angle. It stores energy when knee flexes and assists when knee extends. Both the mechanical experiment and comparison experiment have demonstrated that the PKAExo is able to provide nonlinear assistance torque for weight-climbing, thus decreasing the average maximum load of knee extensor by about 21 per cent, reducing muscle fatigue and enhancing wearer’s weight-climbing ability.
Originality/value
The authors construct theoretic maximum force model produced by knee extensor for weight-climbing in static situation and conduct a series of experiments to verify and revise the model, which is the fundamental reference for knee-assisting mechanism designed for weight-climbing. The authors have also provided and validated an assistant strategy and the mechanism based on the biomechanical analysis, which aims to translate wearer’s energy-providing mode form high load to mid-low load by storing energy when knee flexes and assisting when knee extends. The PKAExo decreases the maximum load of knee extensor, reduces muscle fatigue and helps people to easily climb with load.
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Jianguo Li, Yuwen Gong and Hong Li
This study aims to investigate the structural characteristics, spatial evolution paths and internal driving mechanisms of the knowledge transfer (KT) network in China’s…
Abstract
Purpose
This study aims to investigate the structural characteristics, spatial evolution paths and internal driving mechanisms of the knowledge transfer (KT) network in China’s patent-intensive industries (PIIs). The authors' goal is to provide valuable insights to inform policy-making that fosters the development of relevant industries. The authors also aim to offer a fresh perspective for future spatiotemporal studies on industrial KT and innovation networks.
Design/methodology/approach
In this study, the authors analyze the patent transfer (PT) data of listed companies in China’s information and communication technology (ICT) industry, spanning from 2010 to 2021. The authors use social network analysis and the quadratic assignment procedure (QAP) method to explore the problem of China’s PIIs KT from the perspectives of technical characteristics evolution, network and spatial evolution and internal driving mechanisms.
Findings
The results indicate that the knowledge fields involved in the PT of China’s ICT industry primarily focus on digital information transmission technology. From 2010 to 2021, the scale of the ICT industry’s KT network expanded rapidly. However, the polarization of industrial knowledge distribution is becoming more serious. QAP regression analysis shows that economic proximity and geographical proximity do not affect KT activities. The similarity of knowledge application capacity, innovation capacity and technology demand categories in various regions has a certain degree of impact on KT in the ICT industry.
Originality/value
The current research on PIIs mainly focuses on measuring economic contributions and innovation efficiency, but less on KT in PIIs. This study explores KT in PIIs from the perspectives of technological characteristics, network and spatial evolution. The authors propose a theoretical framework to understand the internal driving mechanisms of industrial KT networks.
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The purpose of this article is to advance the understanding of expatriates' psychological attachment toward both their parent company and its foreign subsidiary by highlighting…
Abstract
Purpose
The purpose of this article is to advance the understanding of expatriates' psychological attachment toward both their parent company and its foreign subsidiary by highlighting how workplace friendships enhance the process of adjustment for expatriates and how these effects on adjustment subsequently translate into expatriates' dual commitment.
Design/methodology/approach
Hypotheses were tested using a sample of 187 expatriates, working in managerial positions, in subsidiaries of multinational corporations, all of whom were assigned expatriates. Serial multiple indirect effects were tested.
Findings
The results indicated that the relationship between workplace friendships and interaction adjustment was supported, but the relationship between workplace friendships and work adjustment was not supported. The serial indirect effects of international adjustment and work adjustment on the relationship between interaction adjustment and expatriates' dual commitment were supported.
Originality/value
This study seeks to fill a gap in the research literature on expatriates by focusing on the issue of workplace friendships and expatriates' dual commitment. The findings help bolster the literature on relational schemas in that expatriates' workplace friendships establish scripts for expatriates' expected outlines of adjustment in work domains. This study also provides insights relevant to the literature on social interaction and adjustment, as the findings support our theory that expatriate commitment is not directly contingent on workplace friendships but rather on the mediating roles of both interaction adjustment and work adjustment.
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María José Andrade-Cuvi, Michelle Guijarro-Fuertes, Analía Concellón, María Gabriela Vernaza and Juan Bravo-Vásquez
The purpose of this paper was to develop a loaf bread enriched with naranjilla (lulo) fruit (shells, seeds and pulp) and determine the technical quality, sensory acceptability and…
Abstract
Purpose
The purpose of this paper was to develop a loaf bread enriched with naranjilla (lulo) fruit (shells, seeds and pulp) and determine the technical quality, sensory acceptability and bioavailability (by in vitro digestion) of antioxidant components.
Design/methodology/approach
Loaf bread was prepared by using a no-time bread-making process. The crumb moisture, specific volume, crust and crumb color, texture profile analysis, analysis of the crumbs' alveoli, sensory evaluation, in vitro simulation of gastrointestinal digestion and antioxidant capacity were determined. Data were analyzed with one-way ANOVA (α = 0.05).
Findings
The specific volume was reduced by 21% (4.62 cm3/g, p < 0.0001), and the hardness was increased by 70% (2.9 N, p < 0.0001). Enrichment of the bread with naranjilla fruit (NF) contributes a yellowish coloration to the bread, which was very well accepted by the consumers and could be considered a natural colorant alternative. Moreover, the sensory evaluation indicated that the analyzed attributes (appearance, color, odor, taste, firmness and overall quality) of the naranjilla bread presented scores higher than 6.5 of 9 points hedonic scale. Naranjilla in the bread formulation had good acceptability by consumers. Naranjilla-enriched bread had an increase in total phenolic (TP)compounds and total carotenoids. In the product without digestion, naranjilla bread increased 1.7 times for TP, 50 times for CT and 1.3 times for TEAC, compared to the control bread (p < 0.0001). The percentage of bioaccessibility for fresh bread without digestion was 39.2 and 53.9% for the control and naranjilla bread, respectively. The addition of NF contributes to a higher TP compounds content and favors its bioavailability.
Practical implications
For bread production, fruits that do not meet the quality standards to be consumed as a natural fruit can be used. In this way, these fruits can contribute as a potential use to reduce agro-industrial waste and as a natural colorant.
Originality/value
Naranjilla is a native fruit from the subtropical Andean regions, which has high ascorbic acid concentrations, making it a fruit rich in antioxidants. Naranjilla-enriched bread contributes with beneficial compounds for the consumer.