Search results

The purpose of this paper is to study the relationship between high temperature oxidation and temperature rise rate of engine oil attempted to explore a new indicator to evaluate oil degradation.

Accelerated oxidation test combined with molecular simulation and road test is carried out in this paper. The temperature rise characteristics of mineral oil and synthetic oil under different oxidation temperatures (140°C, 155°C and 170°C) and time (50 h, 100 h, 150 h and 200 h) were determined by accelerated oxidation. The mechanism of temperature change characteristics of used oils was analyzed with molecular simulation. Two experimental vehicles carried six road tests with synthetic and mineral oil.

The results of this study show that the temperature rise rate of oxidized mineral and synthetic oil is higher than the new oil. The temperature rise rate is proportional to the oxidation time and oxidation temperature. The synthetic engine oil temperature rise rate is lower than that of the mineral engine oil. The same result was obtained in road tests. Molecular simulation verifies that small molecules were generated after oil oxidation which results in intermolecular friction and increased heat generation.

This paper indicates that temperature rise rate has potential to be taken as an indicator to evaluate oil oxidation which provides a new way for engine oil analysis.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0177/

Continua and discontinua coexist in natural rock materials. This paper aims to present an improved approach for addressing the mechanical response of rock masses based on the combined finite-discrete element method (FDEM) proposed by Munjiza.

Several algorithms have been programmed in the new approach. The algorithms include (1) a simpler and more efficient algorithm to calculate the contact force; (2) An algorithm for tangential contact force closer to the actual physical process; (3) a plastic yielding criterion (e.g. Mohr-Coulomb) to modify the elastic stress for fitting the mechanical behavior of elastoplastic materials; and (4) a complete code for the mechanical calculation to be implemented in Matrix Laboratory (MATLAB).

Three case studies, including two standard laboratory experiments (uniaxial compression and Brazilian split test) and one engineering-scale anti-dip slop model, are presented to illustrate the feasibility of the Y-Mat code and its ability to deal with multi-scale rock mechanics problems. The results, including the progressive failure process, failure mode and trajectory of each case, are acceptable compared to other corresponding studies. It is shown that, the code is capable of modeling geotechnical and geological engineering problems.

This article gives an improved FDEM-based numerical calculation code. And, feasibility of the code is verified through three cases. It can effectively solve the geotechnical and geological engineering problems.

The purpose of this paper was to identify talent development practices and processes that enhance professional and career growth of employees in South African higher education institutions (HEIs).

A quantitative study was carried out to investigate the subject matter. A structured questionnaire was used to collect the data from 265 academics in three South African HEIs. The Statistical Package for the Social Sciences, version 27.0, was used to analyse the data. Cronbach’s alpha coefficient and factor analysis were used to test the reliability and validity of the measuring instrument. Pearson’s correlations and regression analysis were used to interpret the relationship between the independent and dependent variables.

The results of the Pearson correlation test established a strong positive influence of training development, coaching and mentoring and career development on talent development. On the other hand, linear regression results indicated that training and development, coaching and mentoring and career development made a strong contribution to the model.

The scope of the study only applied to South African HEIs, making the generalisation of the findings to be limited because of the differences in an organisational context. Hence, future research should focus on different industries.

The study contributes to understanding how talent development can be leveraged to assist academics in HEIs to improve their professional and career goals. The findings suggest that HEIs must invest in talent development to help academics acquire the skills, knowledge and competencies required to perform their tasks.

This paper sheds more light on talent development practices and processes that enhance academic skills, knowledge and competencies in HEIs. Moreover, the study expands on the findings of prior studies concerning talent development in learning organisations.

This article aims to present an overview of the historical development and current status of Chinese small and medium‐sized enterprises (SMEs) examine major political initiatives contributing to SMEs' development and draw out some experience from SME development practices in China.

This paper is exploratory in nature, using archives of government documents and related statistics.

The article argues that the fundamental role of the market in allocating resources and the self‐operation status of SMEs should be respected, that it is imperative to encourage SMEs to optimise industrial structure, and that it is important to properly handle the government‐enterprise relations and bring the role of the government in macro control into full play so as to create a fair competitive environment for SMEs.

The Chinese experience of SME development is of great interest to policy‐makers and academics alike.

The article explores entrepreneurship and SME development in China from a policy‐making perspective.

The study examines the effects of organizational compassion during the COVID-19 pandemic on teachers' mental health and, consequently, their commitment and work engagement. The study tests a serial mediation model for the effects of organizational compassion on employee engagement via mental health and the three components of organizational commitment.

A cross-sectional sample (N = 436) completed an online questionnaire towards the end of the prolonged lockdown of schools in Uganda (2021–2022). Serial mediation analysis in PROCESS Macro was employed to test the hypotheses.

As hypothesized, organizational compassion was significantly related to teachers' mental health, the three components of organizational commitment, and employee engagement. A double mediation path of the effects of organizational compassion on employee engagement via mental health and affective commitment was significant.

The findings highlight how organizational compassion benefits employees’ psychological health and work attitudes and behavior. The findings draw attention to the need to design compassion practices that boost the emotional value of organizational compassion to the individual over the economic and normative value.

The study contributes to the literature on organizational compassion outcomes by focusing on employee engagement and the underlying mediating mechanisms. The study is also one of the few that has examined the effects of organizational compassion on the three components of organizational commitment.

The paper presents reliability, maintainability and life cycle cost (LCC) analysis of a computerized numerical control (CNC) turning center which is manufactured and used in India. The purpose of this paper is to identify the critical components/subsystems from reliability and LCC perspective. The paper further aims at improving reliability and LCC by implementing reliability-improvement methods.

This paper uses a methodology for the reliability analysis based on the assessment of trends in maintenance data. The data required for reliability and LCC analysis are collected from the manufacturers and users of CNC turning center over a period of eight years. ReliaSoft’s Weibull++9 software has been used for verifying goodness of fit and estimating parameters of the distribution. The LCC of the system is estimated for five cost elements: acquisition cost, operation cost, failure cost, support cost and net salvage value.

The analysis shows that the spindle bearing, spindle belt, spindle drawbar, insert, tool holder, drive battery, hydraulic hose, lubricant hose, coolant hose and solenoid valve are the components with low reliability. With certain design changes and implementation of reliability-based maintenance policies, system reliability is improved, especially during warranty period. The reliability of the CNC turning center is improved by nearly 45 percent at the end of warranty period and system mean time between failure is increased from 15,000 to 17,000 hours. The LCC analysis reveals that the maintenance cost, operating cost and support costs dominate the LCC and contribute to the tune of 87 percent of the total LCC.

The proposed methodology provides an excellent tool that can be utilized in industries, where safety, reliability, maintainability and availability of the system play a vital role. The approach may be improved by collecting data from more number of users of the CNC turning centers.

The approach presented in this paper is generic and can be applied to analyze the repairable systems. A real case study is presented to show the applicability of the approach.

The proposed methodology provides a practical approach for the analysis of time-to-failure and time-to-repair data based on the assessment of trends in the maintenance data. The methodology helps in selecting a proper approach of the analysis such as Bayesian method, parametric methods and nonparametric methods.

This study dwells into the crucial aspects of gig workers' jobs that are absent, with specific focus on the work life of food delivery workers (FDWs) and how it impacts their work happiness.

To create a conceptual model, 21 delivery workers were first interviewed, and the data gathered were scrutinized. Subsequently, a questionnaire was sent to 493 delivery partners, probing about their opinions of work factors that could affect their level of happiness. The collected data were put to study by the authors using AMOS and SPSS.

Five missing work components were revealed by qualitative investigation. The absence of voice, recognition, career growth, work satisfaction, and dignity at work contributed to unhappiness of the workers. The qualitative analysis was supported by quantitative findings. Additionally, company policy moderated the relationship between absence of voice, absence of career growth, absence of job satisfaction and absence of work happiness.

To the best of the authors’ knowledge, this is one of the first studies using a mixed-method approach to identify factors contributing to the unhappiness of FDWs in work. The originality of this study also lies in establishing the moderating influence of company policy on the relationship between the absence of voice, absence of career growth, absence of work satisfaction and absence of workplace happiness among the workers.

The purpose of this study was to investigate the factors impacting the intermediating variable of employee engagement toward employee performance in a hybrid working organization in Bangkok, Thailand.

This study uses secondary data analysis and an archival study; the primary data were gathered from 370 employees who are working in a hybrid model environment in a private agricultural machinery company. To construct a new conceptual framework, this study adopted four frameworks from the previous research.

Perceived organizational support and trust and respect in the organization are found to have a significant positive impact on employee engagement. Moreover, there is a significant positive impact of the employee engagement on employee performance in a hybrid working model.

For hybrid work environments, the research focused mainly on the emotional themes of perceived support, trust and respect in the organization. Therefore, there would be many factors that could possibly affect those dependence variables in any environment, which will have to be investigated more in future research. Either in the organization or in the company, many departments and business units operates for the company, but the researcher specifies only the business units or departments that now use the hybrid working model.

This study focuses on a case study of an agricultural machinery company, which likely produces different results than other industries, other industries may produce different results.

Hybrid working models can blur the boundaries between work and personal life, potentially leading to increased stress and burnout. Organizations should prioritize work-life balance and employee well-being by promoting flexible schedules, encouraging breaks and time off, and providing resources for mental health support.

The organization which is operating among a hybrid working model, the increasing of perceived organizational support and trust and respect level, has positively increase the employee engagement toward enhancing the employee performance.

The purpose of this paper is to focus on the removal of hexavalent chromium [Cr(VI)] from wastewater by using activated carbon-supported Fe catalysts derived from walnut shell prepared using a wetness impregnation process. The different conditions of preparation such as impregnation rate and calcination conditions (temperature and time) were optimized to determine their effects on the catalyst’s characteristics.

The catalyst samples were characterized using thermogravimetric analysis, scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption of Cr(VI) by using using activated carbon supported Fe catalysts derived from walnut shell as an adsorbent and catalyst was investigated under different adsorption conditions. The parameters studied were contact time, adsorbent dose, solution pH and initial concentrations.

Results showed that higher adsorption capacity and rapid kinetics were obtained when the activated walnut shell was impregnated with Fe at 5 per cent and calcined under N₂ flow at 400°C for 2 h. The adsorption isotherms data were analyzed with Langmuir and Freundlich models. The better fit is obtained with the Langmuir model with a maximum adsorption capacity of 29.67 mg/g for Cr(VI) on Fe5-AWS at pH 2.0.

A comparison of two kinetic models shows that the adsorption isotherms system is better described by the pseudo-first-order kinetic model.

With the advent of the web computing era, the transmission mode of the Internet of Everything has caused an explosion in data volume, which has brought severe challenges to traditional routing protocols. The limitations of the existing routing protocols under the condition of rapid data growth are elaborated, and the routing problem is remodeled as a Markov decision process. this paper aims to solve the problem of high blocking probability due to the increase in data volume by combining deep reinforcement learning. Finally, the correctness of the proposed algorithm in this paper is verified by simulation.

The limitations of the existing routing protocols under the condition of rapid data growth are elaborated and the routing problem is remodeled as a Markov decision process. Based on this, a deep reinforcement learning method is used to select the next-hop router for each data transmission task, thereby minimizing the length of the data transmission path while avoiding data congestion.

Simulation results show that the proposed method can significantly reduce the probability of data congestion and increase network throughput.

This paper proposes an intelligent routing algorithm for the network congestion caused by the explosive growth of data volume in the future of the big data era. With the help of deep reinforcement learning, it is possible to dynamically select the transmission jump router according to the current network state, thereby reducing the probability of congestion and improving network throughput.