System Investigation for Hybrid Electric Vehicle

A hybrid electric vehicle is a fast-growing concept in the field of vehicle industry. Nowadays two global problems make manufactures to develop such systems. These problems are: the growing cost of a fuel and environmental pollution. Also development of controlled electric drive with high control accuracy and reliability allows improving of vehicle drive characteristics. The objective of this Diploma Thesis is to investigate the possibilities of electrical drive application for new principle of parallel hybrid vehicle system. Electric motor calculations, selection of most suitable control system and other calculations are needed. This work is not final work for such topic. Further investigation with more precise calculations, modeling, measurements and cost calculations are needed to answer the question if such system is efficient.

Active Damping and Energy Recovery in a Hydraulic Boom Controlled by an Electric Drive

The aim of the study is to obtain a mathematical description for an alternative variant of controlling a hydraulic circuit with an electrical drive. The electrical and hydraulic systems are described by basic mathematical equations. The flexibilities of the load and boom is modeled with assumed mode method. The model is achieved and proven with simulations. The controller is constructed and proven to decrease oscillations and improve the dynamic response of the system.

Labor Mobility of the Chinese Graduates from British and Spanish Universities: What Happens to the "Talent Migration"?

The scholarship on migration in Europe heavily focuses on the integration of economically vulnerable migrants. In the age of commercialization of education, however, the European Union attracts a rising number of highly skilled non-EU migrants that take up studies across the continent. Despite economic downturn, the EU universities experience a rapid growth in the number of Chinese students, many of whom settle in Europe upon graduation. Surprisingly, although the number of Chinese students in the EU increases, scholars largely ignore the labor paths that these highly skilled migrants take upon graduating from European universities. This study aims to fill this gap by exploring the variation in the Chinese graduates’ labor incorporation patterns and in their spatial mobility. In this project, I also examine macro-level hypotheses predicting that the EU and host states’ labor market institutions, changes in the EU policies on the highly skilled and the outburst of economic crisis matter for the Chinese highly skilled social and spatial mobility. Seizing on surveys, interviews and on the bodies of literature on stratification and social mobility, economic incorporation, social capital and human capital, I look at the Chinese students that graduated from universities in Great Britain and Spain. These states differ in the university tuition fees, migration policies towards the highly skilled workers and in the period of the Chinese students’ influx, thus providing an economically and socially diverse sample. My research will contribute to the literature on the relations between migrants’ social mobility, class and status background and spatial mobility, at the same time adding a transnational level perspective to the study of highly skilled Asian migration.

Research networks and inventors’ mobility as drivers of innovation evidence from Europe

We investigate the importance of the labour mobility of inventors, as well as the scale, extent and density of their collaborative research networks, for regional innovation outcomes. To do so, we apply a knowledge production function framework at the regional level and include inventors’ networks and their labour mobility as regressors. Our empirical approach takes full account of spatial interactions by estimating a spatial lag model together, where necessary, with a spatial error model. In addition, standard errors are calculated using spatial heteroskedasticity and autocorrelation consistent estimators to ensure their robustness in the presence of spatial error autocorrelation and heteroskedasticity of unknown form. Our results point to the existence of a robust positive correlation between intraregional labour mobility and regional innovation, whilst the relationship with networks is less clear. However, networking across regions positively correlates with a region’s innovation intensity.

Is response to fire influenced by dietary specialization and mobility? A comparative study with multiple animal assemblages

Fire is a major agent involved in landscape transformation and an indirect cause of changes in species composition. Responses to fire may vary greatly depending on life histories and functional traits of species. We have examined the taxonomic and functional responses to fire of eight taxonomic animal groups displaying a gradient of dietary and mobility patterns: Gastropoda, Heteroptera, Formicidae, Coleoptera, Araneae, Orthoptera, Reptilia and Aves. The fieldwork was conducted in a Mediterranean protected area on 3 sites (one unburnt and two burnt with different postfire management practices) with five replicates per site. We collected information from 4606 specimens from 274 animal species. Similarity in species composition and abundance between areas was measured by the Bray-Curtis index and ANOSIM, and comparisons between animal and plant responses by Mantel tests. We analyze whether groups with the highest percentage of omnivorous species, these species being more generalist in their dietary habits, show weak responses to fire (i.e. more similarity between burnt and unburnt areas), and independent responses to changes in vegetation. We also explore how mobility, i.e. dispersal ability, influences responses to fire. Our results demonstrate that differences in species composition and abundance between burnt and unburnt areas differed among groups. We found a tendency towards presenting lower differences between areas for groups with higher percentages of omnivorous species. Moreover, taxa with a higher percentage of omnivorous species had significantly more independent responses of changes in vegetation. High- (e.g. Aves) and low-mobility (e.g. Gastropoda) groups had the strongest responses to fire (higher R scores of the ANOSIM); however, we failed to find a significant general pattern with all the groups according to their mobility. Our results partially support the idea that functional traits underlie the response of organisms to environmental changes caused by fire.

Mobility Among Social Education Students at the University of Girona: Taking Stock of a Decade of Fieldwork Practice Abroad

The following article is divided into five sections, each one with a specific objective. The first section briefly presents the student mobility experiences obtained basically through the fieldwork practice course in social education studies at the University of Girona. The second section delves more deeply to explore the value of the exchange and the student mobility experience over one semester of intensive fieldwork practice. The third section presents data about the students who have participated in this experience inall ten of the graduating classes. The fourth part offers an assessment of the experience and reports which aspects are considered essential to a good student mobility experience. Finally, various actions to be taken to improve these educational experiences within the social education studies at the University of Girona are specified

Inventors on the move: tracing inventors’ mobility and its spatial distribution

This paper aims to provide insights into the phenomenon of knowledge flows. We study one of the main mechanisms through which these flows occur, i.e., the mobility of highly-skilled individuals. We focus on the geographical mobility of inventors across European regions. Thus, patent data are used to trace the pattern of inventors’ mobility across european regions, to track down focuses of attraction of talent throughout the continent, and to study their distribution across the space. To do so, we gather information from PCT patent documents and we first match the names which seemed to belong to the same inventor and then we create a new algorithm to decide whether each patent applied for under each name belongs to the same inventor.

Power line communication in motor cables of variable-speed electric drives − analysis and

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.

Electric field calibration method for scanning electron microscope

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.

Electric field distribution in silicon edgeless detector

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.

The attenuation of concentrations model: a new method for assessing mercury mobility in sediments

In this work we propose a new approach for the determination of the mobility of mercury in sediments based on spatial distribution of concentrations. We chose the Tainheiros Cove, located in the Todos os Santos Bay, Brazil, as the study area, for it has a history of mercury contamination due to a chloro-alkali plant that was active during 12 years. Twenty-six surface sediment samples were collected from the area and mercury concentrations were measured by cold vapour atomic absorption spectrophotometry. A contour map was constructed from the results, indicating that mercury accumulated in a "hot spot" where concentrations reach more than 1 µg g-1. The model is able to estimate mobility of mercury in the sediments based on the distances between iso-concentration contours that determines an attenuation of concentrations factor. Values of attenuation ranged between 0.0729 (East of the hot spot, indicating higher mobility) to 0.7727 (North of the hot spot, indicating lower mobility).

Chaotic dynamics of electric-field domains in periodically driven superlattices

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.

Immigrant occupational mobility: Longitudinal evidence from Spain

This article examines the occupational mobility of immigrants between their countries of origin and Spain on the basis of one of the few surveys available internationally with longitudinal information on immigrant employment in home and host countries. The evidence shows that the occupational status of immigrants in the Spanish labour market is, in general, substantially worse than in their countries of origin. The severe loss of occupational status experienced by immigrants is explained by the combined effect of the intense initial downgrading they experience when entering the Spanish labour market and their very slow occupational progress during their stay in Spain. These findings are more in line with the segmented assimilation theory, which suggests a limited or blocked immigrant occupational mobility, than with the assimilation theory, which predicts a U-shaped evolution in the occupational status of immigrants between their home and host countries. As a result, the Spanish case contrasts sharply with previous evidence for other advanced countries, which tends to support the assimilation perspective. Finally, the empirical evidence suggests that one of the elements impeding the occupational mobility of immigrants in Spain is the significant size of the secondary segment of the labour market, which restricts immigrants' opportunities mainly to low-status occupations.

Electric propulsion system in a modern sports car

In this thesis an electric propulsion system is designed on a device level using Cadence ORCAD. The vehicle belongs to the Helsinki Metropolia University of Applied Sci-ences and it is to compete in the Automotive X-Prize competition held in the USA. In this thesis the electric propulsion system and related electric safety measures are designed. Also electro-magnetic compatibility and interferences present in the system are examined by examining the birth mechanisms and transmission paths of interference. Per device effects of interference and solutions to minimize them were examined and proposed. Suitability of permanent magnet synchronous machines for passenger vehicle use was examined by examining the torque production capability of the motor and the torque requirements of the vehicle. Also a short overview of history of electric vehicles is given.

Electric field measurements using scanning electron microscope

The main idea of this diploma work is to study electric field distribution on the micro level. For this purpose a silicon edgeless detector was chosen as the object of investigation and scanning electron microscope as an investigation tool. Silicon edgeless detector is an important part of installation for studying proton-proton interactions in TOTEM experiment at Large Hadron Collider. For measurement of electric field distribution inside scanning electron microscope a voltage contrast method was applied.