Search results

Friction and wear are very important factors in predicting the performance of journal bearings, particularly under heavy load in start-up processes. However, there are few relevant studies on the numerical model. This study aims to establish a transient-mixed lubrication model to predict the performance of journal bearings, focusing on the friction and wear behavior under heavy load during start-up.

The average Reynold equation, three-dimensional energy equation, shear stress model for friction and Archard model for wear are coupled in the transient model by finite difference method. The linear wear simulation method is bought out to reduce the update times and the calculation time.

The different start-up accelerations and linear wear times set are compared and discussed, which indicates a reasonable start-up acceleration is necessary for journal bearings under heavy load during start-up, and setting linear wear times is an effective method to reduce the simulation time significantly. Furthermore, the wear profile in the start-up process spreads in both the clearance and circumferential directions, but mainly in the clearance direction, which increases the minimum film thickness and affects the friction performance.

This study is of great significance for the numerical prediction of the transient performance of journal bearings during start-up considering friction and wear.

Water lubrication is significant for its environmental friendliness. Composite journal bearing is liable to deform for the huge pressure of water film. This paper aims to study the influence of elastic deformation on how lubrication functions in water-lubricated journal bearings and to provide references for designing composite journal bearings.

The combination of computational fluid dynamics and fluid-structure interaction is adopted in this paper to study the lubrication performance of water-lubricated compliant journal bearings. The influences of elasticity modulus and Poisson’s ratio on load-carrying capacity and elastic deformation are studied for different rotational speeds. Predictions in this work are compared with the published experimental results, and the present work agrees well with the experimental results.

A reference whether elastic deformation should be considered for composite journal bearings is proposed under different working conditions. Besides, a reference to determine water-lubricated plain journal bearings dimensions under different loads and rotational speeds is developed with the effect of both elastic deformation and cavitation being accounted.

The present research provides references as to whether elastic deformation should be considered in operation and to determine compliant journal bearings’ dimensions in the design process.

The purpose of this paper is to improve hydrodynamic load-carrying capacity of a water-lubricated journal bearing by a new bush structure. Water-lubricated bearing is becoming more and more popular since it is environmentally friendly and saves energy. However, contrary to oil and grease-lubricated bearings, water-lubricated bearing is limited in many situations due to its low hydrodynamic load-carrying capacity.

The present article proposes a new bearing bush, with a transition-arc structure, which is favorable for increasing hydrodynamic load-carrying capacity. Hydrodynamic load-carrying capacity was calculated by means of three-dimensional computational fluid dynamics (3-D CFD) analysis. Several variants of a journal bearing with a transition-arc structure of different dimensions are analyzed, while the radial clearance of the bearing, eccentricity ratio and the velocity of the journal remain unchanged.

The results show that obvious changes are found in hydrodynamic load-carrying capacity of a water-lubricated journal bearing. For different width over diameter (L/D) bearing ratios, the relationship between hydrodynamic load-carrying capacity and the magnitude of the transition-arc structure dimension is researched.

The research presented here leads to a design reference guideline that could be used by the designer engineer to design smart journal bearings for improving the hydrodynamic load-carrying capacity.

The purpose of this paper is to achieve attractive fabric composites with excellent tribological performance and investigate the wear mechanisms of these fabric composites sliding against bearing steel pins under dry sliding process.

Five different weave density composites were prepared, and the tribological behaviors of these composites were studied at different testing conditions. Scanning electron microscopy, laser microscopy (three-dimensional profile measurements) and energy-dispersive X-ray spectrometry were used to analyze the worn surface morphology, wear volume and elemental content of the transfer films, respectively.

The composite weave density serves an important influence on tribological behavior. Generally, the wear rate of each composite increased with increasing weave density, and the friction coefficient of each composite decreased with increasing weave density.

Nanoparticle-filled hybrid polytetrafluoroethylene/Kevlar fabric composites with proper weave density have exhibited superior tribological properties in dry sliding conditions. The results that obtained in this paper may offer a reference for others who intend to achieve attractive fabric composites with excellent tribological performance.

The purpose of this study is to examine the effect of the religiosity of the chief executive officer (CEO) on Indonesian banks’ performance.

The research method used was a review of the annual reports of banking companies in Indonesia from 2015 to 2019 and a web-based search to determine the religiosity of the CEOs. This study comprised 88 banking companies in Indonesia that come under the supervision of the Financial Services Authority.

The results of this study show that banks led by religious CEOs had better financial performance, as measured by their ROA and ROE, than those led by not very spiritual CEOs. These results indicate the importance of religiosity in organizations, especially at the top management level, for achieving better bank performance.

This research results show that religiosity plays an essential role in the banking business sector. This research adds to the literature on CEOs’ characteristics based on their religiosity and the concomitant effect on banking performance.

This study shows how individual religious beliefs influence the corporate behavior of top management, particularly the CEOs, and why this is crucial for organizational decision-making. This study measures an individual's religiosity (i.e. a CEO) based on that individual's actions in their workplace environment.

The purpose of this paper is to solve the azimuth sensitivity of a high-resolution range profile (HRRP), which is one of the biggest obstacles faced by a radar automatic target recognition (RATR) system.

Aimed at addressing the shortcomings of the equal angular-sector segmentation based on the scatterer model, an adaptive angular-sector segmentation is proposed on the basis of grey incidence analysis (GIA).

The main conclusions reached are as follows. First, the adaptive angular-sector segmentation in terms of GIA is suitable for RATR based on the HRRP; and, second, the adaptive angular-sector segmentation based on the type-B degree of grey incidence model is better than the Deng-Si degree of grey incidence model and the degree of grey slope incidence model.

The outcome obtained in this paper can be selected for the RATR application.

This paper has been built on the basis of previous research achievements, and a new RATR method of adaptive angular-sector segmentation is presented based on the GIA.

The purpose of this paper is to review the literature and provide an overview of the history, evolution and existing research on continuous improvement (CI). It reviews a large number of research papers in this field and presents the overview of various CI implementation practices demonstrated by manufacturing organizations globally.

The paper systematically categorizes the published literature, analyzes and reviews it methodically.

The paper reveals the important concepts, case studies and surveys in concerned with CI methodology. The contributions of CI programmes towards improving manufacturing performance of the organizations and CI values that underlies continuous improvement have also been highlighted.

The literature on classification of CI has so far been very limited. The paper reviews a large number of papers in this field and presents the overview of various CI practices demonstrated by manufacturing organizations globally. Further the future implications have also been discussed for the smooth and effective implementation of CI practices in manufacturing organizations.

The paper contains a comprehensive listing of publications on the field in question and their classification. It will be useful to researchers, professionals and others concerned with this subject to understand the significance of CI methodology.

The purpose of this paper is to uncover the significance of green supply chain management (GSCM) to study the impact lean practices, namely, Kaizen and innovation management practices on organizational sustainability.

The subject of green supply chains attracts a growing interest in academic and professional literature since 1990. Questionnaire survey and structured interviews (set of questions) among the industrial professionals and academicians of northern India region have been performed to ascertain the significance of GSCM toward organizational sustainability. Structural equation modeling, Cronbach’s alpha, z-test, correlation and t-test have been used to ascertain the significance of lean practices toward sustaining organization by taking the mediating effect of GSCM.

The results signify the negative potential of combined Kaizen, innovation management and government policies on environmental thinking through supply chain. The innovation management strategies and Kaizen individually has positive influence on environment supply chain but government policies should be improved to improve the positive impact on environmental thinking through supply chain by decreasing pollution. Economic performance, environmental performance and competitive performance are significantly improved by implementing Kaizen and innovation management through GSCM.

The research is limited to northern India. Moreover, selection of industry and academic organizations has been done on convenient sampling technique.

The paper demonstrates the application of lean techniques, namely, Kaizen and innovation management practices, showing how it can bring real breakthroughs in organizational sustainability through GSCM.

Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American preemptive invasion and occupation of Afghanistan and Iraq and the subsequent prisoner abuse, such an existence seems to be farther and farther away from reality. The purpose of this work is to stop this dangerous trend by promoting justice, love, and peace through a change of the paradigm that is inconsistent with justice, love, and peace. The strong paradigm that created the strong nation like the U.S. and the strong man like George W. Bush have been the culprit, rather than the contributor, of the above three universal ideals. Thus, rather than justice, love, and peace, the strong paradigm resulted in in justice, hatred, and violence. In order to remove these three and related evils, what the world needs in the beginning of the third millenium is the weak paradigm. Through the acceptance of the latter paradigm, the golden mean or middle paradigm can be formulated, which is a synergy of the weak and the strong paradigm. In order to understand properly the meaning of these paradigms, however, some digression appears necessary.

The concept and practice of e-services has become essential in business transactions. Yet there are still many organizations that have not developed e-services optimally. This is especially relevant in the context of Indonesian Airline companies. Therefore, many airline customers in Indonesia are still in doubt about it, or even do not use it. To fill this gap, this study attempts to develop a model for e-services adoption and empirically examines the factors influencing the airlines customers in Indonesia in using e-services offered by the Indonesian airline companies. Taking six Indonesian airline companies as a case example, the study investigated the antecedents of e-services usage of Indonesian airlines. This study further examined the impacts of motivation on customers in using e-services in the Indonesian context. Another important aim of this study was to investigate how ages, experiences and geographical areas moderate effects of e-services usage.

The study adopts a positivist research paradigm with a two-phase sequential mixed method design involving qualitative and quantitative approaches. An initial research model was first developed based on an extensive literature review, by combining acceptance and use of information technology theories, expectancy theory and the inter-organizational system motivation models. A qualitative field study via semi-structured interviews was then conducted to explore the present state among 15 respondents. The results of the interviews were analysed using content analysis yielding the final model of e-services usage. Eighteen antecedent factors hypotheses and three moderating factors hypotheses and 52-item questionnaire were developed. A focus group discussion of five respondents and a pilot study of 59 respondents resulted in final version of the questionnaire.

In the second phase, the main survey was conducted nationally to collect the research data among Indonesian airline customers who had already used Indonesian airline e-services. A total of 819 valid questionnaires were obtained. The data was then analysed using a partial least square (PLS) based structural equation modelling (SEM) technique to produce the contributions of links in the e-services model (22% of all the variances in e-services usage, 37.8% in intention to use, 46.6% in motivation, 39.2% in outcome expectancy, and 37.7% in effort expectancy). Meanwhile, path coefficients and t-values demonstrated various different influences of antecedent factors towards e-services usage. Additionally, a multi-group analysis based on PLS is employed with mixed results. In the final findings, 14 hypotheses were supported and 7 hypotheses were not supported.

The major findings of this study have confirmed that motivation has the strongest contribution in e-services usage. In addition, motivation affects e-services usage both directly and indirectly through intention-to-use. This study provides contributions to the existing knowledge of e-services models, and practical applications of IT usage. Most importantly, an understanding of antecedents of e-services adoption will provide guidelines for stakeholders in developing better e-services and strategies in order to promote and encourage more customers to use e-services. Finally, the accomplishment of this study can be expanded through possible adaptations in other industries and other geographical contexts.