The strength of conveyor belts splices made in mines rarely reaches full belt strength. It consists of a number of factors. The primary is the method of their construction and proper selection of ingredients. The significant impact has also has splice quality covering both keeping proper geometry matched to the belt construction and belts working conditions and adherence to the best practices in the field of technologies of their construction.Difficult conditions in underground mines and pressure on reducing conveyor downtime (avoiding production losses) is reflected by a drop in static and dynamic splices strength. This is confirmed by numerous studies of belt splices strength and fatigue life conducted in the Laboratory of Belt Conveying (LTT) within the framework of research and expert opinions commissioned by belt manufacturers and their users. The consequence of too insufficiently low belt splices strength is their low durability, decreasing reliability and, consequently, higher mining transportation costs. Belt splices are in fact the weakest link in the serial structure which form closed loops of interconnected belt sections working in series of conveyors transporting excavated material in the mine. The article presents the results of simulation analyzes analyses investigating how the increase of belt splices durability may contribute to the reduction of transportation costs in the underground mines.
The problem of governments’ over-indebtedness is one of the most important challenges for today’s EMU governance. As numbers suggest, the problem of extensive deficits has appeared in the EMU long before the burst of the global financial crisis. We suspect that the membership in a currency area might be partially blamed for such progression of indebtedness. This paper examines the determinants of government risk premiums in the EU Member States to answer if the risk premium assigned by the market may give currency area Member States additional incentives for profligacy. Controlling other factors, we investigate the pattern in which fiscal deficits and GDP growth affect the yield of 10-year-maturity government bonds in the euro area and the non-euro area EU Member States. Our results are straightforward. The market penalizes EU countries that do not belong to the euro area for bad economic performance and extensive deficits from 4 to 7 times stronger. Our estimates confirm the strong impact of the common credibility problem in the EMU but also support the key role of financial stress in determining the cost of government debt.
The focus of research works on cavitation has changed since the 1960s; the behaviour of a single bubble is no more the area of interest for most scientists. Its place was taken by the cavitating flow considered as a whole. Many numerical models of cavitating flows came into being within the space of the last fifty years. They can be divided into two groups: multifluid and homogeneous (i.e., single-fluid) models. The group of homogenous models contains two subgroups: models based on transport equation and pressure based models. Several works tried to order particular approaches and presented short reviews of selected studies. However, these classifications are too rough to be treated as sufficiently accurate. The aim of this paper is to present the development paths of numerical investigations of cavitating flows with the use of homogeneous approach in order of publication year and with relatively detailed description. Each of the presented model is accompanied by examples of the application area. This review focuses not only on the list of the most significant existing models to predict sheet and cloud cavitation, but also on presenting their advantages and disadvantages. Moreover, it shows the reasons which inspired present authors to look for new ways of more accurate numerical predictions and dimensions of cavitation. The article includes also the division of source terms of presented models based on the transport equation with the use of standardized symbols.
Despite the large number of studies conducted on teachers’ oral corrective feedback, the findings of these studies have been mainly limited to cognitive orientations rooted in experimental designs and the verbal discourse of the teacher as the main object of inquiry. Considering teachers’ affective concerns regarding their corrective feedback and the shift from negative psychology to positive psychology in the field of second/foreign language teaching as well as the entirety of the teacher’s corrective repertoire, in this case study, we aimed to explore the enjoyment building capacity of a teacher’s multimodal corrective feedback in a university general English course. We video-recorded the teacher’s multimodal corrective feedback including verbal and nonverbal semiotic resources like gesture, gaze, and posture while observing the learners’ emotional experiences for eight sessions. We also conducted stimulated recall interviews with some learners and collected their written journals about the experiences of enjoyment with regard to the teacher’s multimodal corrective feedback scenarios. The teacher’s multimodal corrective feedback was analyzed through systemic functional multimodal discourse analysis (SF-MDA) and the content of the interview transcripts as well as the written journals were qualitatively analyzed. The findings indicated that the teacher’s inherent multimodality in his corrective feedback broadened the main dimensions of enjoyment by raising the learners’ attention to their errors, heightening their focus on the correct form, and increasing the salience of his corrective feedback. Further arguments regarding the findings are discussed.
Recent research has reported that an increasing number of migrants in Norway are concentrated in the low-skilled sectors of the labour market, irrespective of their educational background, thus facilitating the formation of migrant niches in the long term. Despite the growing body of literature that raises the problem of downward professional mobility and deskilling among migrant populations, little scholarly attention has been paid to migrants’ struggles and vulnerabilities as a result of underemployment. Drawing on 30 in-depth interviews, this article explores the common experience of habitus mismatch and suffering among Poles who have worked below their level of competence or professional experience since migrating to Norway. By an-alysing subjective experiences of downward professional and social mobility and the conflict between valued and stigmatised identities, the article examines the various habitus mismatches that contribute to suffering in downwardly mobile Polish migrants.