This Thesis deals with the methodological support for the creation of an e-shop for importers of specialist, small series cars. The intention is to design the methodical pattern of making electronic commerce for businesses with defined characters and its verification in a business operating in the specified field. The first step to achieving the target is characterized by the essential elements of the business entity and analyzing the current state of knowledge in the area of e-commerce. The following step is to chose the formulation of the methodological pattern. The final step is a formal description of the methodological model, which is then verified in the importer environment. The results of the methodical pattern may be used by other similar businesses to create their own e-shop.

Microfinance was rapidly hailed as a poverty alleviation tool by development agencies, researchers and practitioners. Despite the increasing capacity of MFIs to manage their financial sustainability, impact studies available report disappointingly low social achievements. Social performance assessment tools available struggle to combat a narrow MFI-centric approach which often overlooks contextual issues and institutional characteristics which can influence MFIs’ poverty reduction potential. This research’s main objective is to identify which and explain how organisational structures and management systems impact on MFIs’ social performance. This work uses a bottom-up research strategy, based on a 10-month extensive fieldwork in Bangladesh, a 490 household data-set, an ethnographic community study in Modhupur and institutional analyses of ASA and PDBF. It analyses the livelihoods, capitals and strategies of rural households in Bangladesh, explores their perceptions and experiences of microfinance and examines the management of socio-financial trade-offs within MFIs at different hierarchical levels. The research’s main findings seriously question the poverty reducing potential of standardised commercialised microfinance in settings characterised by vulnerability, shocks and seasonality, such as rural Bangladesh. It finds that although most MFIs have similar poverty reduction missions it is the way in which their organisational structures, managementsystems and working cultures are arranged that shapes their financial and social achievements. There is strong evidence that commercial MFIs can experience a silent practice drift at the field level in Bangladesh and that the commercialisation of MFIs provides strong incentives for the field staff to prioritise the achievement of their financial targets to the detriment of social performance, discouraging them from reporting low social performance. There are therefore few reasons why MFI senior managers should question their model and policies. This drift can manifest itself through malpractices hard-selling of loans, poor client selection and follow-up procedures, forcing clients into borrowing more and larger loans, using extreme forms of pressure through abusive language and behaviours and micro-collateral. This process usually has longer-term negative impacts on clients, especially the very poor who adopt successive short-term coping tactics to meet inflexible repayment schedules. This thesis concludes that commercial microfinance should not be targeted to the poorest and that more consideration should be given to clientselection and follow-up procedures. This thesis argues that the commercialisation of the global microfinance industry serves the interests of diverse stakeholders who contribute to maintaining the industry’s reputation though the media. This can be deemed an iceberg industry (that shows little of its actual workings and impacts to the public) which is sustained through considerable support from an increasing number of private investors for whom MFIs’ commercial expansion (regardless of its social achievements) serves their financial and political interests.

This research has assessed the environmental and economic sustainability of domestic micro-generation technologies under UK conditions as both individual technologies and as part of a range of future energy supply scenarios for the domestic sector extending to 2050. A life cycle approach has been used for both environmental and economic assessment considering the relevant sustainability impacts, which include global warming potential, the depletion of fossil fuels, human toxicity and life cycle cost. The micro-generation technologies studied were selected on the basis of their ability to contribute to current and future energy supply and also their suitability under UK conditions. These technologies were micro-wind, solar photovoltaics, micro-combined heat and power, heat pumps and solar thermal water heating. The technologies were compared with one another and with the incumbent technologies, which were grid electricity and natural gas condensing boilers. Three journal papers have been published as a result of this research. The evaluation of micro-generation technologies on a life cycle basis indicated that despite reducing certain environmental impacts, all technologies increased at least one and as many as eight environmental impacts compared to their current fossil-fuel alternatives. All micro-generation technologies would reduce global warming and fossil fuel depletion compared to conventional technologies, highlighting their potential to contribute to energy policy goals. However, they cannot currently compete with conventional technologies for capital cost, although their life cycle costs – taking into account incentives from schemes such as Feed-in Tariffs – can be competitive. Considering both environmental and economic implications suggested that Stirling engine micro-combined heat and power is one of the most sustainable options for heat and electricity generation. The results also suggested that heat pumps should not be receiving incentives from the Government due to their poor environmental performance. Four potential future energy supply scenarios for the UK domestic sector were studied extending to 2050. The scenarios varied in terms of the level of effort made to improve the environmental and economic sustainability of the sector. Scenario 1 involved no further implementation of micro-generation beyond 2009, increasing energy demand and a grid electricity dominated by fossil fuels. In contrast, Scenario 4 portrayed a future where there is 1 micro-generation technology per dwelling, a 50% reduction in demand and almost complete decarbonisation of the grid mix. The results indicated that a huge transformation of the sector is required to achieve the 80% reduction in CO2 emissions by 2050. This would include halving energy demand, almost complete decarbonisation of grid electricity and the installation of a micro-generation unit in every dwelling. To conclude, despite the level of interest micro-generation is currently receiving, this work suggested their usage may not necessarily be as beneficial as some believe. Their use does reduce greenhouse gas emissions and fossil fuel consumption; however, to have any influence on energy policy goals this use would have to be widespread. Furthermore, reduced emissions will come at the expense of other environmental impacts. Finally, with a number of the technologies not yet cost competitive – even with incentives – the Government focus on measures to reduce demand and decarbonise the grid may prove to be a better option as this work suggested that energy policy goals could be achieved without high penetration of micro-generation.

La lévitation diamagnétique est un des rares phénomènes permettant de soustraire des corps à la gravité. Si la répulsion diamagnétique est négligeable à nos échelles, elle devient significative aux petites dimensions, allant jusqu’à entraîner, sous certaines conditions, la mise en lévitation de micro-objets diamagnétiques. A travers le développement de microaimants, de modèles numériques et analytiques ainsi que de réalisations expérimentales, ces travaux explorent les potentialités de la lévitation diamagnétique de microgouttes et de particules dans un milieu paramagnétique. Ils démontrent notamment la possibilité de mesurer précisément l’interaction entre gouttes chargées en lévitation. Ces travaux analysent par ailleurs l’étude de cette lévitation combinée à une force diélectrophorétique. Cette étude ouvre de nouvelles perspectives pour le tri de bille diamagnétique basé sur leur taille ou leur susceptibilité. La diélectrophorèse ouvre le champ des possibilités en permettant d’actionner sans contact des micro-billes mises en lévitation. / Diamagnetic levitation is one of the rare way to compensate action of gravity. This kind of repulsion is negligible at our scale. However, at microscale, this effect becomes significant and can achieve levitation of diamagnetic objects. Through the development of micromagnets of numerical and analytical models as well as experimental achievements , these works explore the potential of diamagnetic levitation microdroplets and particles in a paramagnetic environment. They especially demonstrate the ability to accurately measure the interaction between charged droplets levitated . These studies analyze further the study of this levitation combined with dielectrophoretic force . This study opens new perspectives for sorting diamagnetic ball based on their size or susceptibility. Dielectrophoresis opens possibilities in the field for actuating contactless microbeads levitated.

Due to the increasing demand for high power and reliable miniaturized energy storage devices, the development of micro-supercapacitors or electrochemical micro-capacitors have attracted much attention in recent years. This dissertation investigates several strategies to develop on-chip micro-supercapacitors with high power and energy density. Micro-supercapacitors based on interdigitated carbon micro-electrode arrays are fabricated through carbon microelectromechanical systems (C-MEMS) technique which is based on carbonization of patterned photoresist. To improve the capacitive behavior, electrochemical activation is performed on carbon micro-electrode arrays. The developed micro-supercapacitors show specific capacitances as high as 75 mFcm-2 at a scan rate of 5 mVs-1 after electrochemical activation for 30 minutes. The capacitance loss is less than 13% after 1000 cyclic voltammetry (CV) cycles. These results indicate that electrochemically activated C-MEMS micro-electrode arrays are promising candidates for on-chip electrochemical micro-capacitor applications. The energy density of micro-supercapacitors was further improved by conformal coating of polypyrrole (PPy) on C-MEMS structures. In these types of micro-devices the three dimensional (3D) carbon microstructures serve as current collectors for high energy density PPy electrodes. The electrochemical characterizations of these micro-supercapacitors show that they can deliver a specific capacitance of about 162.07 mFcm-2 and a specific power of 1.62mWcm-2 at a 20 mVs-1 scan rate. Addressing the need for high power micro-supercapacitors, the application of graphene as electrode materials for micro-supercapacitor was also investigated. The present study suggests a novel method to fabricate graphene-based micro-supercapacitors with thin film or in-plane interdigital electrodes. The fabricated micro-supercapacitors show exceptional frequency response and power handling performance and could effectively charge and discharge at rates as high as 50 Vs-1. CV measurements show that the specific capacitance of the micro-supercapacitor based on reduced graphene oxide and carbon nanotube composites is 6.1 mFcm-2 at scan rate of 0.01Vs-1. At a very high scan rate of 50 Vs-1, a specific capacitance of 2.8 mFcm-2 (stack capacitance of 3.1 Fcm-3) is recorded. This unprecedented performance can potentially broaden the future applications of micro-supercapacitors.

Orientador: Ines Joekes / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-07-19T23:50:15Z (GMT). No. of bitstreams: 1 Zucchetti_RobertoAlcantaraMartins_D.pdf: 10106058 bytes, checksum: f150abb4b24b9252a7aa33fe6c699d5d (MD5) Previous issue date: 1994 / Doutorado

Micro-seismology is attracting more and more attention in the exploration seismology community. The main goal in micro-seismic imaging is to find the source location and the ignition time in order to track the fracture expansion, which will help engineers monitor the reservoirs. Conventional imaging methods work fine in this field but there are many limitations such as manual picking, incorrect migration velocity and low signal to noise ratio (S/N). In traditional surface survey imaging, full waveform inversion (FWI) is widely used. The FWI method updates the velocity model by minimizing the misfit between the observed data and the predicted data. Using FWI to locate and image microseismic events allows for an automatic process (free of picking) that utilizes the full wavefield. Use the FWI technique, and overcomes the difficulties of manual pickings and incorrect velocity model for migration. However, the technique of waveform inversion of micro-seismic events faces its own problems. There is significant nonlinearity due to the unknown source location (space) and function (time). We have developed a source independent FWI of micro-seismic events to simultaneously invert for the source image, source function and velocity model. It is based on convolving reference traces with the observed and modeled data to mitigate the effect of an unknown source ignition time. The adjoint-state method is used to derive the gradient for the source image, source function and velocity updates. To examine the accuracy of the inverted source image and velocity model the extended image for source wavelet in z-axis is extracted. Also the angle gather is calculated to check the applicability of the migration velocity. By inverting for the source image, source wavelet and the velocity model simultaneously, the proposed method produces good estimates of the source location, ignition time and the background velocity in the synthetic experiments with both parts of the Marmousi and the SEG Overthrust model. On the other hand, a new imaging condition of natural Green’s function has been implemented to mitigate the effect of the unknown velocity model. It is based on putting receivers in a horizontal well close to the micro-seismic events so that only a small part of the velocity model is required for the imaging. In order to focus the multi scattering energy to the source location, as well as to suppress the influence of the noise in the data, we introduced a new method to compensate the energy in the receiver wavefield. It is based on reflection waveform inversion (RWI) theory. We simply migrate for the scatters (reflectors) in the medium, and set the image as a secondary source to compensate for the multi scattering energy in the receiver wavefield. By applying the same imaging condition, the energy of those scattering events can be traced to the source location. Thus the source point has higher energy in the source image. A simple two-layer medium test demonstrates the features.

The micro frog, Microbatrachella capensis (Boulenger, 1910), is a Critically Endangered anuran found in fragmented marshland habitats along the southern coast of the Western Cape Province of South Africa. The genetic diversity between and within the remaining populations (Kenilworth, Grootwitvlei, Kleinmond, Lamloch, Hagelkraal, and Buffeljacht/Ratelrivier) of Microbatrachella capensis in the Western Cape Province of South Africa was assessed, sampling 12 specimens from each population. Genetic diversity was determined from an analysis of mitochondrial DNA sequences obtained from the ND2 gene region/locus. A phylogeographic analysis of the populations of micro frogs sampled was used to determine the current genetic structure and the history of the species. The analysis divided the six populations of the species into two lineages. The variation within the populations ranged from two to six haplotypes per population. Nested clade analysis inferred allopatric fragmentation for three out of the five significant clades. The division of the lineages into two geographical units, the absence of gene flow and the allopatric fragmentation indicates long-term isolation, around 1.09-1.52 my ago. The isolation and fragmentation of the populations is postulated to be due to historical sea level fluctuations that occurred in Southern Africa during the Quaternary Period. Allopatric fragmentation and lack of gene flow among populations within the two major lineages are due to recent habitat destruction through development. The recognition that the species contains two evolutionarily significant units, corresponding to Agulhas and western lineages, will aid future conservation efforts to save this species. / Dissertation (MInstAgrar)--University of Pretoria, 2005. / Zoology and Entomology / unrestricted

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Shared micromobility defines as the shared use of light and low-speed vehicles such as bike and scooter in which users have short-term access on an as-needed basis. As shared micromobility, as one of the most viable and sustainable modes of transportation, has emerged in the U.S. over the last decade., understanding different aspects of these modes of transportation help decision-makers and stakeholders to have better insights into the problems related to these transportation options. Designing efficient and effective shared micromobility programs improves overall system performance, enhances accessibility, and is essential to increase ridership and benefit commuters. This dissertation aims to address three vital aspects of emerging shared micromobility transportation options with three essays that each contribute to the practice and literature of sustainable transportation. Chapter one of this dissertation investigates public opinion towards dockless bikes sharing using a mix of statistical and natural language processing methods. This study finds the underlying topics and the corresponding polarity in public discussion by analyzing tweets to give better insight into the emerging phenomenon across the U.S. Chapter two of this dissertation proposes a new framework for the micromobility network to improve accessibility and reduce operator costs. The framework focuses on highly centralized clubs (known as k-club) as virtual docking hubs. The study suggests an integer programming model and a heuristic approach as well as a cost-benefit analysis of the proposed model. Chapter three of this dissertation address the risk perception of bicycle and scooter riders’ risky behaviors. This study investigates twenty dangerous maneuvers and their corresponding frequency and severity from U.S. resident’s perspective. The resultant risk matrix and regression model provides a clear picture of the public risk perception associated with these two micromobility options. Overall, the research outcomes will provide decision-makers and stakeholders with scientific information, practical implications, and necessary tools that will enable them to offer better and sustainable micromobility services to their residents.