Optimization of a fuel injection system for diesel and biodiesel usageBreda Kegl
, Marko Kegl
, Stanislav Pehan
, 2008, original scientific article
Abstract: This paper presents an optimization procedure of a fuel injection system of a bus diesel engine. Attention is focused on the differences resulting from using two different types of fuel: diesel and biodiesel. The proposed design procedure relies on the assumption that the atomization of fuel spray influences the diesel engine performance, fuel consumption, and harmful emission significantly. As a measure of spray atomization, the Sauter mean diameter is employed and introduced into the objective function. The design problem is formulated in the form of a multiobjective optimization problem, taking into account the ESC 13 mode test for diesel engines of commercial vehicles. The design variables of the injection system are related to the shape of the cam profile, to the nozzle geometry, and to the control parameters influencing the injection quantity and timing. The geometrical properties of the cam profile and the injection parameters are kept within acceptable limits by the imposed constraints. The results of optimization using diesel and biodiesel are compared to each other to show the influence offuel type on final design and performance of the system.
Keywords: fuel injection system, diesel engine, biodiesel fuel, engine performance, numerical simulations
Published: 31.05.2012; Views: 1336; Downloads: 48
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The analysis of barriers in succession processes of family business with the use of grey incidence analysis (Polish Perspective)Ewa Więcek-Janka
, Rafał Mierzwiak
, Joanna Kijewska
, 2016, original scientific article
Abstract: The article presents results of research on the identification and evaluation of barriers faced by successors in family businesses during the first process of succession. The analysis of empirical material used grey systems theory, which was considered as an equivalent for the analysis of small samples and qualitative research. While conducting the literature review and empirical study, the authors concentrated on (a) the identification of barriers in the development of family firms and (b) eliciting the perspective of the new generation of owners in family firms entering the succession process through an empirical analysis of the assessed level of risk in relationships with family and business.
Keywords: family business, company performance, business efficiency, leadership, ownership, family, risk, research, grey incidence analysis, grey system theory
Published: 14.11.2017; Views: 531; Downloads: 220
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Giving-up management system certificationMilena Alič
, original scientific article
Abstract: The paper presents the dynamics in number of top management system certificates (ISO 9001, ISO 14001) focusing on the situation in Slovenia in the last two years when a significant increase of cancelled certificates was noticeable. We studied this phenomenon in order to find out its reasons and effects on the performance of the organizations. Some recognized relations between quality management systems and company performance from literature review were used for setting hypotheses which were analytically proved. We assumed that quitting management system certificates was related to decrease in business performance. Empirical part of our research was based on the data of Slovenian certification bodies and on published annual financial reports of Slovenian organizations. In the survey some characteristics and performance of the organizations which gave up certification were analysed. We came to interesting findings that cancelling certificates was related to decrease in business performance and often even to closing of organizations. The downsizing of the business was increasing through the time. So, 2 years after cancelling certificates only 8% of the organizations still present growth in their income and revenue, besides almost 40% of them quit or would have to quit their business. It was also found out that the business performance after cancellation of the certificates was related to the business performance before it and to the reason for cancellation as well. Two years after cancellation there was a 3-times higher proportion of failed organizations (= 45% of previously non-profitable organizations) among the organizations that had operated at a loss before the cancellation of their certificates, compared to those previously having a profit. Among the claimed reasons for certificate cancellation organizational changes (in 35% of all the organizations losing certificates) and cancellation of certificates by certification bodies (in 41% of these organizations) were the most common ones related to the failure of these organizations.
Keywords: management system (MS), quality management system (QMS), ISO 9001, ISO 14001, certificate, business performance
Published: 30.11.2017; Views: 278; Downloads: 55
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