Zhiping Zhu, Chun Shi, Yu Zhang and Zhifeng Liu
The purpose of this paper is to study the effects of Cl− and direct stray current on the soil corrosion of three grounding grid materials.
Abstract
Purpose
The purpose of this paper is to study the effects of Cl− and direct stray current on the soil corrosion of three grounding grid materials.
Design/methodology/approach
The electrochemical corrosion properties of three grounding grid materials, which include the Q235 steel, Q235 galvanized flat steel and copper, were measured by means of the weak polarization curve method and electrochemical impedance spectroscopy; the corrosion rate of specimens was calculated using the weight loss method; and the specimen surfaces were characterized using the scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction analysis.
Findings
Results showed that both factors, Cl− and direct stray current, can accelerate the corrosion rate of grounding grid materials. The magnitude of DC stray current density affected the mass transfer type and response frequency of the anode and cathode reaction of grounding materials, while the Cl− contents of the soil only affect the mass transfer rate of the electrode material from the electrochemical impedance spectroscopy diagrams. The electric field generated by the DC stray current caused Cl− directed migration. The larger the DC stray current density, the greater the diffusion process and the greater the weight loss rate of the grounding grid materials that would have a logarithmic relationship with the Cl− content at the same DC stray current density. The corrosion resistance of the three materials is copper > Q235 galvanized flat steel > Q235 flat steel.
Originality/value
The paper provides information regarding the relationship among Cl−, direct stray current and corrosion of three grounding grid materials by means of electrochemical impedance spectroscopy. Meanwhile the weight loss rate is the logarithmic relationship with the Cl− content, which is useful for understanding the corrosion mechanism of Q235 steel, Q235 galvanized flat steel and copper under the condition of Cl− and direct stray current in soil.
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Victoria Gurieva, Anastasia Ilyina, Sergey Klyuev, Magomed Saidumov, Tolya Khezhev, Igor Nedoseko, Roman Fediuk, Vitaly Shamanov and Batyr Yazyev
The study suggests that the high concentration of mining and metallurgical enterprises on the territory of the Russian Ural region determines the need to consider industrial…
Abstract
Purpose
The study suggests that the high concentration of mining and metallurgical enterprises on the territory of the Russian Ural region determines the need to consider industrial waste, including nickel slag, as a possible raw material for the production of ceramic bricks. The article describes the properties of clays and nickel slag obtained at metallurgical enterprises in the Orenburg region and the features of their use as components in the composition of ceramic bricks.
Design/methodology/approach
To achieve this purpose, such tasks as determining the technological parameters of production, conducting the X-ray phase and microstructural analysis of the obtained samples were solved.
Findings
Compositions of ceramic mass using clay from the Khalilovsky deposit (Orenburg region) with the addition of nickel slag (20 and 40% by weight) have been developed, and their physical and mechanical properties (compressive strength, bending strength, water absorption and density) have been determined. With the help of modern research methods involving high-tech equipment, the microstructure is considered and the phase composition of the finished samples is determined. As a result of the conducted research, it was found that the composition of the selected clay and nickel slag in the obtained rational composition ensures the production of ceramic bricks of grades M175 and M200.
Originality/value
This is the first study on the use of nickel slag for the production of ceramic bricks. The results relate primarily to Russian feedstocks, but a methodology is presented that can be applied to other countries as well as to other silica-containing feedstocks.
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Namita Jain, Asha Thomas, Vikas Gupta, Mario Ossorio and Daniele Porcheddu
The research aims to measure the effectiveness of collaborative learning exchanges transpired through digital tools and technologies (DT&Ts) employed by the mentor universities…
Abstract
Purpose
The research aims to measure the effectiveness of collaborative learning exchanges transpired through digital tools and technologies (DT&Ts) employed by the mentor universities during the COVID-19 pandemic by conducting an empirical study on undergraduate students in Indian higher educational institutions (HEIs) under the mentorship program based on the corporate social responsibility (CSR) initiative. The pandemic scenario, its impact on the mentor university's social responsibility and the way DT&Ts can assist are investigated in this article.
Design/methodology/approach
The interactions with experts and students were conducted to explore the DT&Ts for learning exchanges. Next, structural equation modeling (SEM) was performed to validate the model and perform regression analysis. The quantitative data collection was made through questionnaires during the second deadly wave of COVID-19 that hit India.
Findings
The independent variables (IVs) such as the IT infrastructure support (IT_IS), virtual collaborative tools (VCTs) and future-oriented technologies (FOTs) have a significant impact on the CSR learning outcomes (CSR_LOs) of undergraduate students under the mentorship program. However, IV research instruments for innovation could not make a significant effect.
Research limitations/implications
The IVs IT_IS, VCTs and FOTs influence the CSR_LOs, while RII does not have an influential impact.
Practical implications
As the online learning environment is expected to stay at least in a blended form, adequate CSR funding in infrastructure is necessitated to harness the full potential of this important resource, technology. The results of this empirical investigation affirm that IT_IS, VOTs and FOTs significantly impact CSR_LOs during the crisis. The study findings would encourage the mendtor universities and their stakeholders, including the mentee universities, to evolve and create an ecosystem for effective management of these resources to attain positive outcomes. The study findings can guide the mentor universities in managing uncertainties like pandemics and effectively using the earlier-mentioned critical resources for social responsibility. This research also allows the development of future applications adnd models in mentor-mentee universities for social responsibility, post-pandemic transformation and resilience.
Social implications
The DT&Ts came to the immediate rescue during the pandemic and positively affected collaborative CSR_LOs by the mentor universities, but they have not evolved to a level where offline learning can be replaced entirely. Hence, it can be inferred that a hybrid model is preferable. The study also improves the understanding of how DT&Ts are being harnessed to aid collaborative learning in fulfilling the mentors' CSR in fatal emergencies. The purpose is to equip the education system through mentorship so that universities can sustain, innovate and grow even in trying times. Also, it discusses the dynamics of various DT&Ts for creating a sustainable learning environment and utilizing them to make the teaching prolific and influential.
Originality/value
There is a scarcity of literature regarding the learning outcomes realized through CSR initiatives and collaboration between mentor-mentee institutions. There is a need to understand how these knowledge exchanges continued despite the physical restrictions during the pandemic. In this direction, this study helps to understand how the DT&Ts played a critical role in continuing learning and keeping abreast in a knowledge society from the perspective of resource-based view (RBV) in these precarious situations.
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Yasmina Bahlil, Djamil Krouf, Zoheir Mellouk, Nawal Taleb-Dida and Akila Guenzet
This study aims to examine whether Globularia alypum (Ga) lyophilized aqueous leaves extract treatment improves cardiometabolic syndromes such as hyperglycemia, lipid profiles and…
Abstract
Purpose
This study aims to examine whether Globularia alypum (Ga) lyophilized aqueous leaves extract treatment improves cardiometabolic syndromes such as hyperglycemia, lipid profiles and oxidative damage resulting from a high-fructose diet induced in hypertriglyceridemic rats.
Design/methodology/approach
A total of 24 male Wistar rats weighing 80 ± 5 g were first randomly divided into 2 groups. A total of 12 control rats (C) were fed a standard-diet (St-D) and 12 high fructose (HF) rats were fed a high-fructose diet (HF-D) containing St-D in which cornstarch was substituted by fructose (61.4%). After 15 weeks of feeding, body weight (BW) was about 320 ± 20 g and hypertriglyceridemia was noted in HF vs C group (2.69 ± 0.49 mmol/L) vs (1.25 ± 0.33 mmol/L). Each group of rats was then divided into two equal groups (n = 6) and fed during four weeks either a St-D or HF-D, treated or not with 1% of Ga extract (C-Ga) and (HF-Ga). After 28 days, fasting rats were anesthetized and blood and tissues were removed to measure biochemical parameters.
Findings
The results showed no significant differences in BW and insulinemia between all groups. Ga extract supplementation reduced glycemia (−36%), glycosylated hemoglobin (−37%), Homeostasis Model of Assessment-Insulin Resistance index (−34%) and triacylglycerol’s contents in plasma (−33%), very low density lipoproteins–low density lipoproteins (VLDL-LDL) (−48%), liver (−52%) and aorta (−39%); total cholesterol concentrations in aorta was 3.7-fold lower in HF-Ga vs HF group. Ga treatment reduced lipid peroxidation in plasma, VLDL-LDL, red blood cells (RBC), liver, muscle and kidney by improving superoxide dismutase (SOD) activity and glutathione peroxidase (GPx) in RBC and catalase (CAT) activity in kidney (p < 0.05). Moreover, Ga ameliorates glutathione (GSH) production in RBC (+41%) and kidney tissues (+35%).
Originality/value
Ga extract ameliorated cardiometabolic syndrome by its hypotriglyceridemic effect and prevented development of insulin resistance. It reduces lipid peroxidation by enhancing non-enzymatic (GSH) and enzymatic (SOD, GPx and CAT) antioxidant defense systems in high-fructose hypertriglyceridemic rats. Therefore, supplementation of Ga leaves extract as an adjuvant could be used for the treatment of hypertriglyceridemia and the prevention and/or the management of cardio-metabolic adverse effects.
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Mohd Daud Norzaidi and Mohamed Intan Salwani
Using the extended task‐technology fit (TTF) model, this paper aims to examine technology resistance, technology satisfaction and internet usage on students' performance.
Abstract
Purpose
Using the extended task‐technology fit (TTF) model, this paper aims to examine technology resistance, technology satisfaction and internet usage on students' performance.
Design/methodology/approach
The study was conducted at Universiti Teknologi MARA, Johor, Malaysia and questionnaires were distributed to 354 undergraduate students.
Findings
The structural equation modelling (SEM) results indicate that technology satisfaction and the internet usage significantly explains the variance on students' performance. Task‐technology fit is not a predictor of technology resistance but it does predict the internet usage. The internet usage has greater impact on technology satisfaction than technology satisfaction on the internet usage. Finally, technology resistance is not a predictor of students' performance.
Research limitations/implications
The study focuses only on education in Malaysia and concentrates only on the students' performance and the relationship between technology resistance, technology satisfaction and the internet usage.
Practical implications
The results provide insights on how Malaysian education systems of a similar structure could improve upon their internet adoption.
Originality/value
This study is perhaps one of the first to address internet adoption in education using an extended task‐technology fit model (task‐technology fit, internet usage, technology resistance, technology satisfaction) to investigate their influences on students' performance.
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Mohd Daud Norzaidi, Siong Choy Chong, Raman Murali and Mohamed Intan Salwani
Using the extended task‐technology fit (TTF) model, the purpose of this paper is to examine the impact of intranet usage on middle managers' performance in the port industry.
Abstract
Purpose
Using the extended task‐technology fit (TTF) model, the purpose of this paper is to examine the impact of intranet usage on middle managers' performance in the port industry.
Design/methodology/approach
The study was conducted on 357 middle managers from various organisations in the Malaysian port industry.
Findings
The structural equation modelling results indicate that TTF and usage significantly explains the variance on managers' performance. TTF is a predictor of perceived usefulness and usage but it does not predict user resistance. Perceived usefulness is a predictor of usage but it does not predict user resistance. User resistance does not predict managers' performance.
Research limitations/implications
The study focuses only on the port industry in Malaysia and concentrates only on the management perspective of intranet usage.
Practical implications
The results provide insights on how the Malaysian port industry and other organisations of a similar structure could improve on their intranet adoption.
Originality/value
This study is perhaps one of the first to address the intranet adoption in the port industry using a comprehensive, extended TTF model (perceived usefulness, usage, user resistance) to investigate their influences on individual job performance.
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The purpose of this paper is to provide the historical background of genealogical records and analyze the value of Chinese genealogical research through the study of names and…
Abstract
Purpose
The purpose of this paper is to provide the historical background of genealogical records and analyze the value of Chinese genealogical research through the study of names and genealogical resources.
Design/methodology/approach
The paper examines the historical evolution and value of Chinese genealogical records, with the focus on researching the Islamic Chinese names used by the people living in Guilin. The highlight of this paper includes the analysis and evolution of the Islamic Chinese names commonly adopted by the local people in Guilin. It concludes with the recommendations on emphasizing and making the best use of genealogical records to enhance the research value of Chinese overseas studies.
Findings
The paper covers the history of Islam and describes how the religion was introduced into China, as well as Muslims' ethnicity and identity. It also places focus on the importance of building a research collection in Asian history and Chinese genealogy.
Research limitations/implications
This research study has a strong subject focus on Chinese genealogy, Asian history, and Islamic Chinese surnames. It is a narrow field that few researchers have delved into.
Practical implications
The results of this study will assist students, researchers, and the general public in tracing the origin of their surnames and developing their interest in the social and historical value of Chinese local history and genealogies.
Social implications
The study of Chinese surnames is, by itself, a particular field for researching the social and political implications of contemporary Chinese society during the time the family members lived.
Originality/value
Very little research has been done in the area of Chinese local history and genealogy. The paper would be of value to researchers such as historians, sociologists, ethnologists and archaeologists, as well as students and anyone interested in researching a surname origin, its history and evolution.
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Abstract
Purpose
The purpose of this paper is to propose a two-degrees-of-freedom wire-driven 4SPS/U rigid‒flexible parallel trunk joint mechanism based on spring, in order to improve the robot’s athletic ability, load capacity and rigidity, and to ensure the coordination of multi-modal motion.
Design/methodology/approach
First, based on the rotation transformation matrix and closed-loop constraint equation of the parallel trunk joint mechanism, the mathematical model of its inverse position solution is constructed. Then, the Jacobian matrix of velocity and acceleration is derived by time derivative method. On this basis, the stiffness matrix of the parallel trunk joint mechanism is derived on the basis of the principle of virtual work and combined with the deformation effect of the rope driving pair and the spring elastic restraint pair. Then, the eigenvalue distribution of the stiffness matrix and the global stiffness performance index are used as the stiffness evaluation index of the mechanism. In addition, the performance index of athletic dexterity is analyzed. Finally, the distribution map of kinematic dexterity and stiffness is drawn in the workspace by numerical simulation, and the influence of the introduced spring on the stiffness distribution of the parallel trunk joint mechanism is compared and analyzed. It is concluded that the stiffness in the specific direction of the parallel trunk joint mechanism can be improved, and the stiffness distribution can be improved by adjusting the spring elastic structure parameters of the rope-driven branch chain.
Findings
Studies have shown that the wire-driven 4SPS/U rigid‒flexible parallel trunk joint mechanism based on spring has a great kinematic dexterity, load-carrying capacity and stiffness performance.
Research limitations/implications
The soft-mixed structure is not mature, and there are few new materials for the soft-mixed mixture; the rope and the rigid structure are driven together with a large amount of friction and hindrance factors, etc.
Practical implications
It ensures that the multi-motion mode hexapod mobile robot can meet the requirement of sufficient different stiffness for different motion postures through the parallel trunk joint mechanism, and it ensures that the multi-motion mode hexapod mobile robot in multi-motion mode can meet the performance requirement of global stiffness change at different pose points of different motion postures through the parallel trunk joint mechanism.
Social implications
The trunk structure is a very critical mechanism for animals. Animals in the movement to achieve smooth climbing, overturning and other different postures, such as centipede, starfish, giant salamander and other multi-legged animals, not only rely on the unique leg mechanism, but also must have a unique trunk joint mechanism. Based on the cooperation of these two mechanisms, the animal can achieve a stable, flexible and flexible variety of motion characteristics. Therefore, the trunk joint mechanism has an important significance for the coordinated movement of the whole body of the multi-sport mode mobile robot (Huang Hu-lin, 2016).
Originality/value
In this paper, based on the idea of combining rigid parallel mechanism with wire-driven mechanism, a trunk mechanism is designed, which is composed of four spring-based wire-driven 4SPS/U rigid‒flexible parallel trunk joint mechanism in series. Its spring-based wire-driven 4SPS/U rigid‒flexible parallel trunk joint mechanism can make the multi-motion mode mobile robot have better load capacity, mobility and stiffness performance (Qi-zhi et al., 2018; Cong-hao et al., 2018), thus improving the environmental adaptability and reliability of the multi-motion mode mobile robot.
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Ke Ma, Yu Li, Guoyang Liu, Gang He, Chun Sha and Yilin Peng
The purpose of this study is to investigate the deformation characteristics and failure modes of the right bank slope of Xiluodu Hydropower Station after excavation.
Abstract
Purpose
The purpose of this study is to investigate the deformation characteristics and failure modes of the right bank slope of Xiluodu Hydropower Station after excavation.
Design/methodology/approach
Micro-seismic monitoring technology is applied to obtain the microfracture information and study the internal damage evolution law of the slope rock mass. A numerical model for discontinuous deformation analysis (DDA) is established to analyse the deformation characteristics and failure mode of the slope. Micro-seismic monitoring and DDA can verify and supplement each other's results in the investigation of slope failure.
Findings
The results show that the slope has a downhill displacement along the weathered zone under natural conditions; the maximum resultant displacement at the monitoring point is 380 mm. The micro-seismic events are concentrated in an area located 30–100 m horizontally away from the slope surface and at an elevation of 390–470 m. The distribution of these micro-seismic events is consistent with the location of the unloading and weathered zones; it is the same as the DDA simulation result.
Originality/value
The study is anticipated to be used as reference for the stability analysis of rock slopes. By combining the continuous (micro-seismic monitoring technology) and discontinuous (DDA) methods, the entire process starting from the gradual accumulation of internal rock micro-damage to the macroscopic discontinuous deformation and failure of the slope can be investigated.
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Chun Yang, Bart Bossink and Peter Peverelli
Building on resource dependence theory and the dynamic institution-based view, this paper examines the influence of government affiliations on firm product innovation in a dynamic…
Abstract
Purpose
Building on resource dependence theory and the dynamic institution-based view, this paper examines the influence of government affiliations on firm product innovation in a dynamic institutional environment.
Design/methodology/approach
Using unique panel data of Chinese manufacturing firms covering a period of 12 years (1998–2009) with 2,564,547 firm-year observations, this study chooses the panel Tobit model with random effects to explore the influence of government affiliations on firm product innovation, followed by an analysis to test the moderation effects of dynamic institutional environments.
Findings
The study findings suggest that Chinese firms with higher-level government affiliations have a relatively high product innovation performance. It finds that this innovation stimulating effect is contingent on the dynamic nature of the institutional environment. To be specific, a high speed of institutional transition may depress the positive innovation effects of government affiliations, while a more synchronized transition speed of institutional components may enhance the positive innovation effects of firms' government affiliations.
Originality/value
This study adds to a better understanding of the drivers of product innovation in Chinese firms that are situated in environments that are characterized by institutional change, using and contributing to resource dependence theory and the dynamic institution-based view.