996 resultados para Electric transformer industry


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This paper aims to analyse cooperation in R&D in the automobile industry in Spain. It first examines to what extent firms cooperate with external actors in the field of technological innovation, and if so, with what type of cooperation partner, paying special attention to the differentiation according to the size of the firms. Second, it aims to study how the firm’s size may affect not only the decision of cooperating but also with which type of partner, while controlling for other determinants that have been considered in the literature as main drivers of collaborative activities in R&D. We use data provided by the Technological Innovation Panel in the 2006-2008 period for firms in the automotive sector. We estimate a bivariate probit model that takes into account the two types of cooperation mostly present in the automotive industry, vertical and institutional, explicitly considering the interdependencies that may arise in the simultaneous choice of both.

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The objective of the master’s thesis is to define the warranty practices and costs in the welding machines manufacturing company and do a proposal for a warranty policy based on the practices and costs. The study include a disquisition of the warranty practices in the subsidiaries and distributor sales. The disquisition of the warranty practices introduces the information relates to warranty period, warranty costs, including repair, spare part and other costs, the practices with the replaced parts, the utilization rate of the eWarranty system and information relates to special arrangements in the warranties. The warranty costs are defined besides the group level also separately per regions and product families. From some product families the disquisition is done per products. In this study is also done a proposal for a warranty policy for the company. The proposal speaks out the length of warranty period, the compensation of the warranty costs, the practices with replaced parts and usage of eWarranty system.

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Data transmission between an electric motor and a frequency converter is required in variablespeed electric drives because of sensors installed at the motor. Sensor information can be used for various useful applications to improve the system reliability and its properties. Traditionally, the communication medium is implemented by an additional cabling. However, the costs of the traditional method may be an obstacle to the wider application of data transmission between a motor and a frequency converter. In any case, a power cable is always installed between a motor and a frequency converter for power supply, and hence it may be applied as a communication medium for sensor level data. This thesis considers power line communication (PLC) in inverter-fed motor power cables. The motor cable is studied as a communication channel in the frequency band of 100 kHz−30 MHz. The communication channel and noise characteristics are described. All the individual components included in a variable-speed electric drive are presented in detail. A channel model is developed, and it is verified by measurements. A theoretical channel information capacity analysis is carried out to estimate the opportunities of a communication medium. Suitable communication and forward error correction (FEC) methods are suggested. A general method to implement a broadband and Ethernet-based communication medium between a motor and a frequency converter is proposed. A coupling interface is also developed that allows to install the communication device safely to a three-phase inverter-fed motor power cable. Practical tests are carried out, and the results are analyzed. Possible applications for the proposed method are presented. A speed feedback motor control application is verified in detail by simulations and laboratory tests because of restrictions for the delay in the feedback loop caused by PLC. Other possible applications are discussed at a more general level.

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This paper is a literature review which describes the construction of state of the art of permanent magnet generators and motors constructing and discusses the current and possible application of these machines in industry. Permanent magnet machines are a well-know class of rotating and linear electric machines used for many years in industrial applications. A particular interest for permanent magnet generators is connected with wind mills, which seem to be becoming increasingly popular nowadays. Geared and direct-driven permanent magnet generators are described. A classification of direct-driven permanent magnet generators is given. Design aspects of permanent magnet generators are presented. Permanent magnet generators for wind turbines designs are highlighted. Dynamics and vibration problems of permanent magnet generators covered in literature are presented. The application of the Finite Element Method for mechanical problems solution in the field of permanent magnet generators is discussed.

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The paper industry has been experiencing remarkable structural changes since paper demand growth has ceased and some markets are declining. One reason behind the declined demand is the Internet, which has partially substituted the newspaper as a source of information. Paper products alone can no longer provide livelihood, and the paper industry has to find new business areas. In this research, we studied radio frequency identification (RFID), and the market opportunities it could provide for paper industry. The research combined a quantitative industry analysis and qualitative interviews. RFID is a growing industry in the beginning of its life cycle, in which value chains and technologies still evolve significantly. The industry is going to concentrate on the future, and in the long term RFID-identifiers will probably be printed on paper substrate or directly onto products. Paper industry has the chance to enter the RFID industry, but it has to obtain the required competences, for example through acquisitions. The business potential RFID offers to paper industry is inadequate, and while reviewing new strategic options, the paper industry must consider more options, for example the entire printed intelligence.

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A paradigmatic shift in developing fuel cell for stationary applications has been occurring in the last ten years. Previously, 100 kW class to a few MW class power plants were preferred but recently, the development has drifted towards units of only a few kW. The motivation is the present market situation, which favors disperse residential electric power generation from natural or liquefied gas. Membrane-type fuel cells are very promising for this application, due to their present state of development in the automobile industry. More recently, small ceramic fuel cells (SOFC) has also been found to be adequate for this application. Considering a family of 4 members, 1 kW (electric) units seem to be optimal for individual residences. This presentation discusses briefly the Brazilian scenario with respect to these units.

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The objective of this study is to resolve how customer retention is managed in Finnish health and fitness clubs, and how is this comparable with the theoretical aspects of customer retention. It is also discussed how the process leading to customer retention is handled, and what the essential elements of customer retention and loyalty are specifically in the health and fitness club industry. In addition, it is discussed to what extent do health and fitness club companies implement the elements of customer retention in their businesses. Finally, there is discussion about the relationship and priority between the behavioral and attitudinal methods of creating retention in the companies. The data was collected by interviewing the management of six health and fitness clubs from different geographical regions in Finland. Results indicated that the most important constructs concerning customer retention were switching barriers, pricing strategy, competitive aspect, corporate image, service quality, employee retention, and customer satisfaction. In addition, the implementation of customer retention was found to vary between different sized companies and companies from different geographical locations. Moreover, it was discovered that the companies put more effort in constructs that are considered to create customer loyalty instead of retention.

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Induction motors are widely used in industry, and they are generally considered very reliable. They often have a critical role in industrial processes, and their failure can lead to significant losses as a result of shutdown times. Typical failures of induction motors can be classified into stator, rotor, and bearing failures. One of the reasons for a bearing damage and eventually a bearing failure is bearing currents. Bearing currents in induction motors can be divided into two main categories; classical bearing currents and inverter-induced bearing currents. A bearing damage caused by bearing currents results, for instance, from electrical discharges that take place through the lubricant film between the raceways of the inner and the outer ring and the rolling elements of a bearing. This phenomenon can be considered similar to the one of electrical discharge machining, where material is removed by a series of rapidly recurring electrical arcing discharges between an electrode and a workpiece. This thesis concentrates on bearing currents with a special reference to bearing current detection in induction motors. A bearing current detection method based on radio frequency impulse reception and detection is studied. The thesis describes how a motor can work as a “spark gap” transmitter and discusses a discharge in a bearing as a source of radio frequency impulse. It is shown that a discharge, occurring due to bearing currents, can be detected at a distance of several meters from the motor. The issues of interference, detection, and location techniques are discussed. The applicability of the method is shown with a series of measurements with a specially constructed test motor and an unmodified frequency-converter-driven motor. The radio frequency method studied provides a nonintrusive method to detect harmful bearing currents in the drive system. If bearing current mitigation techniques are applied, their effectiveness can be immediately verified with the proposed method. The method also gives a tool to estimate the harmfulness of the bearing currents by making it possible to detect and locate individual discharges inside the bearings of electric motors.

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This paper proposes a calibration method which can be utilized for the analysis of SEM images. The field of application of the developed method is a calculation of surface potential distribution of biased silicon edgeless detector. The suggested processing of the data collected by SEM consists of several stages and takes into account different aspects affecting the SEM image. The calibration method doesn’t pretend to be precise but at the same time it gives the basics of potential distribution when the different biasing voltages applied to the detector.

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This Master’s Thesis work reports about electric field distribution in recently developed silicon edgeless detector with a new current terminating structure. This structure enables the essential reduction of insensitive detector area as well as allows separation of the current flowing through the active area from the current flowing at the cut edge. The reliable operation of this detector is strongly needed due to the installation inside LHC. In accordance with formulated problems SEM was used as an investigation tool for collecting the data about electric field distribution.

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Traditionally, fossil fuels have always been the major sources of the modern energy production. However prices on these energy sources have been constantly increasing. The utilization of local biomass resources for energy production can substitute significant part of the required energy demand in different energy sectors. The introduction of the biomass usage can easily be started in the forest industry first as it possesses biomass in a large volume. The forest industry energy sector has the highest potential for the fast bioenergy development in the North-West Russia. Therefore, the question concerning rational and effective forest resources use is important today as well as the utilization of the forestry by-products. This work describes and analyzes the opportunities of utilising biomass, mainly, in the form of the wood by-products, for energy production processes in general, as well as for the northwest Russian forest industry conditions. The study also covers basic forest industry processes and technologies, so, the reader can get familiar with the information about the specific character of the biomass utilization. The work gives a comprehensive view on the northwest forest industry situation from the biomass utilisation point of view. By presenting existing large-scale sawmills and pulp and paper mills the work provides information for the evaluation of the future development of CHP investments in the northwest Russian forest industry.

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This research focuses on the career experiences of women managers in the IT industry in China and Finland, two countries with different cultures, policies, size of population, and social and economic structures regarding work-life support and equal opportunities. The object of this research is to present a cross-cultural comparison of women’s career experiences and how women themselves understand and account for their careers. The study explores how the macro and the micro levels of cultural and social processes become manifested in the lives of individual women. The main argument in this thesis is that culture plays a crucial role in making sense of women’s career experiences, although its role should be understood through its interrelationship with other social processes, e.g., institutional relations, social policies, industrial structures and organizations, as well as globalization. The interrelationship of a series of cultural and social processes affects individuals’ attitudes to, and arrangement and organization of, their work and family lives. This thesis consists of two parts. The first part introduces the research topic and discusses the overall results. The second part comprises five research papers. The main research question of the study is: How do cultural and social processes affect the experiences of women managers? Quantitative and qualitative research methods, which include in-depth interviews, Q-methodology, interpretive analysis, and questionnaires, are used in the study. The main theoretical background is culturally sensitive career theory and the theory of individual differences. The results of this study are viewed through a feminist lens. The research methodology applied allows new explorations on how demographic factors, work experiences, lifestyle issues, and organizational cultures can jointly affect women’s managerial careers. The sample group used in the research is 42 women managers working in IT companies in China (21) and Finland (21). The results of the study illustrate the impact of history, tradition, culture, institutional relations, social politics, industry and organizations, and globalization on the careers of women managers. It is claimed that the role of culture – cultural norms within nations and organizations – is of great importance in the relationship of gender and work. Women’s managerial careers are affected by multiple factors (personal, social and cultural) reflecting national and inter-individual differences. The results of the study contribute to research on careers, adding particularly to the literature on gender, work and culture, and offering a complex and holistic perspective for a richer understanding of pluralism and global diversity. The results of the study indicate how old and new career perspectives are evidenced in women managers in the IT industry. The research further contributes to an understanding of women’s managerial careers from a cross-culture perspective. In addition, the study contributes to the literature on culture and extends understanding of Hofstede’s work. Further, most traditional career theories do not perceive the importance of culture in determining an individual’s career experience and this study richens understanding of women managers’ careers and has considerable implications for international human resource management. The results of this study emphasize the need, when discussing women managers’ careers, to understand the ways by which gendering is produced rather than merely examining gender differences. It is argued that the meaning of self-knowledge is critical. Further, the environment where the careers under study develop differs greatly; China and Finland are very different – culturally, historically and socially. The findings of this study should, therefore, be understood as a holistic, specific, and contextually-bound.

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The goal of the master's thesis is a detailed research of the technical wind energy potential in Russian Federation: the distribution of the potential all over the territory of the country and the possibility of the application of the potential for power supply of various objects. The main attention of the thesis is devoted to the assessment of wind energy resources (potential) of Russian Federation, both for the territory of country in whole and for every region. Theoretical basic wind energy concepts and the scheme of transformation of kinetic energy of a wind into electric energy by modern wind turbines are given in the work. Also the costs of energy, stimuli of development of wind-engineering and obstacles which impact the industry development are analyzed. The review of existent and projected wind power plants in Russia is carried out.

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The strategic group theory provides an intermediate level of analysis between a single company and the whole industry for identifying issues about the company's competitive position and strategic choices. Strategic groups are companies within an industry with similar strategic characteristics or competing on similar bases. Strategic choices are aligned with the firms’ resources. The purpose of this study was to identify the strategic groups in the wind energy industry in Europe, and study, whether a certain group membership results in financial performance differences. Altogether 80 European wind energy companies were included in the study, which were clustered into four strategic groups according to their age and growth rate. Each group corresponds to a different strategy. The results show that the wind energy companies can be clustered according to the chosen strategic characteristics. Strategic decisions were investigated with characteristic variables. Performance variables were used in the analysis measuring profitability, liquidity and solvency of the groups. These strategic choices of the companies did not have a significant influence on the firms’ performance. The more mature and slower growing group proved to be the most successful. However, the differences between groups were generally not statistically significant. The only statistically significant difference found was in the solvency ratio between Mature Slow and Young Rapid groups. Measured with these variables, more mature and slower growing companies performed better. Therefore, a certain strategic group membership results in performance differences.

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Self-sustained time-dependent current oscillations under dc voltage bias have been observed in recent experiments on n-doped semiconductor superlattices with sequential resonant tunneling. The current oscillations are caused by the motion and recycling of the domain wall separating low- and high-electric-field regions of the superlattice, as the analysis of a discrete drift model shows and experimental evidence supports. Numerical simulation shows that different nonlinear dynamical regimes of the domain wall appear when an external microwave signal is superimposed on the dc bias and its driving frequency and driving amplitude vary. On the frequency-amplitude parameter plane, there are regions of entrainment and quasiperiodicity forming Arnold tongues. Chaos is demonstrated to appear at the boundaries of the tongues and in the regions where they overlap. Coexistence of up to four electric-field domains randomly nucleated in space is detected under ac+dc driving.