The thesis deals with possibilities and ways of child's development in their preschool age. The aim of this thesis is to prove a positive effect of controlled kinetic activities on the development of children's abilities, skills and knowledge at the age from two to four, namely in the frame of all five educational spheres RVP PV. There was used the method of an experiment consisting in a realization of a fourteen-day-search based on a schooling program using both kinetic and non- kinetic activities, on an input and output measuring the level of the same partial abilities, skills and knowledge for two eight-member-groups of children and also comparing acquired results. It was found out that kinetic activities of preschool children can be used within the educational process as one of its elements with comparable effect to using non-kinetic activities. Keywords Movement, ontogenetic evolution, child's development, preschool age, play

In the following years, the countries will have to face an increase in the energy demand. So far, the fossil fuels have been the main source to meet the energy demand, but they involve serious problems: they contribute to the climate change with high emissions of greenhouse gases, there is an uneven distribution of these resources and their reserves are finite. The renewable energies are the most reliable alternative, with a very low environmental impact in comparison. Among them, the photovoltaics seems to be the most promising emerging technology for the electricity generation. Its rapid growth in the last years has been due to the reduction achieved in the cost of the PV panels. When planning a PV installation, it is essential to be able to estimate the production. The power of a PV-module is given by the manufacturer at standard conditions (STC), which means that the irradiance is G=1000W/m2 at normal incidence and the temperature of the module is 25˚C. However, these conditions will never be reached in a real installation. Therefore, the measured power of the system has to be adjusted for the real conditions so that the real production and performance can be estimated. Today there exists no standard method for this procedure in Sweden. The main aim of this thesis is to develop a theoretical model for the four PV-systems installed at the laboratories (building 45) of the University of Gävle to estimate the performance and production, and prove its validity by comparing with real data measured with a short time resolution (second). This will also allow to know if the power generated by the modules is the promised one by the providers. Three of the studied systems have monocrystalline silicon modules, with different schemes: one system with bypass diodes, another with TIGO optimizers, and the third one with microinverters. The fourth system has thin film modules. The theoretical model considers correction factors for the cell temperature, the angle of incidence and the real irradiation reaching the modules’ surface; as all these aspects reduce the power obtained. When studying this model for clear sunny days, it can be observed that the theoretical model adjusts perfectly for the four systems in these conditions and almost a completely linear dependence is achieved between the measured and estimated power. The worse adjustment is obtained for the thin film system, for which the theoretical model gives lower values than the real ones. However, a better approximation can be obtained for this system by adjusting the value of the correction factor for the cell temperature. Moreover, the high values obtained for the maximum power during the clear days, very close to the peak power, indicates that the maximum power value provided by the manufacturers is in concordance with the real performance of the modules. In case of cloudy days, a small-time delay has been appreciated between the data recorded by both logger. The results have been studied with the raw data, obtained worse adjusting, and correcting this time discordance, getting again accurate results from the theoretical model.

Les travaux effectués dans cette thèse portent sur les problématiques de couplage de centrales photovoltaïques sur les réseaux de distribution haute tension africains. Ces réseaux sont pour la plupart caractérisés par leur instabilité, leur faible maillage et leur faible puissance installée. Une première partie traite des caractéristiques des centrales photovoltaïques connectées au réseau Haute Tension et leurs interactions avec ce dernier. Une deuxième partie de la thèse est consacrée à la modélisation des systèmes électriques (réseaux électriques, systèmes photovoltaïques etc.). Une approche de modélisation du générateur photovoltaïque pour des centrales de grande puissance a été proposée. Un cluster PV de 500 kWc a été proposé et simulé et ses performances évaluées. Les dispositifs de commande utilisés dans le cluster proposé prennent en compte les contraintes techniques nécessaires au transfert optimal de puissance et de la qualité de la tension entre le générateur PV et le réseau électrique. En application, une centrale PV de 20 MWc a été modélisée et simulée. L’impact de sa connexion sur le réseau national du Burkina a été évalué sur le plan de la stabilité en tension tant en fonctionnement normal qu’en situation de dysfonctionnement. L’approche de la stratégie de raccordement des centrales PV et l’impact de la modularité de ces dernières ont été aussi analysés. / The research work performed in this thesis focuses on the problems of coupling photovoltaic power plants to the African high-voltage distribution environments. African power systems are mostly characterized by a high degree of instability, low meshed and low power installed networks. The first part of this work deals with photovoltaic power plants connected to the high-voltage grid, its general behaviors and its interactions with the grid. The second part is devoted to the modeling of electrical power systems included photovoltaic systems. A modeling approach of a photovoltaic generator for large power plant was proposed. A photovoltaic cluster of 500 kWp system is proposed and simulated, and its performance evaluated. The design of the control systems used in the proposed cluster has taken into account the technical requirements needed for optimal power transfer and good quality of the voltage at the point of common coupling. Furthermore, a 20 MWp power plant connected to the national grid of Burkina Faso has been modeled and simulated, and their interactions have been evaluated in terms of voltage steady-state stability both in normal operation and in the dysfunction state. The approach to the strategy in terms of connecting PV power plants, and the impact of using modular photovoltaic power plants has also been analyzed.

This thesis aimed for a better understanding of the Nordic weather conditions in terms of snow induced soiling on the performance and production of an established photovoltaic plant located on the roof of Økern nursing home, Oslo. In order to realize the main aim, several steps had to be done in preparation of the main analysis, these steps in fact are as important to this thesis as the main deliverable. The search for appropriate meteorological data proved to be not an easy task because of the scarcity of ground measurement stations, and the high inaccuracies in satellite observations. After analyzing all the sources with available data for the region of Oslo, three sources of data were chosen based on comparisons to an onsite set of reference measurements, these are the Blindern meteo station, the NASA SSE satellite derived observations, and the STRANG data base. A model of the actual system was created in PVsyst, exceptional attention to the level of detail was exercised in order to approach the case of eliminating any source of variation in the simulated models other than the required study parameter, the soiling. Simulations of many system variants ultimately resulted in the aggregation of a soiling loss profile to be used in conjunction with each of the meteo sources to predict the snow induced soiling consequences on the system. The soiling loss profiles were tested and the results compared to actual system production measurements, and it was successful in introducing the correction the model needed to simulate the system closely to reality. However, absolute change in production figures is relatively small, therefore, this study and any future continuation of it is oriented into research and improvement as it possess minimal impact on a commercial application.

This research project was based on the Design, Implementation and Evaluation of a Photovoltaic Water heating system in South Africa, Eastern Cape Province. The purpose of the study was to design and investigate the scientific and economic contribution of direct water cooling on the photovoltaic module. The method involved performance comparison of two photovoltaic modules, one naturally cooled (M1) and the other, direct water cooled module (M2). Module M2 was used to produce warm water and electricity, hence, a hybrid system. The study focused on comparing the modules’ efficiency, power output and their performance. The temperatures attained by water through cooling the module were monitored as well as the electrical energy generated. A data logger and a low cost I/V characteristic system were used for data collection for a full year. The data were then used for performance analysis of the modules. The results of the study revealed that the directly water cooled module could operate at a higher electrical efficiency for 87% of the day and initially produced 3.63% more electrical energy each day. This was found to be true for the first three months after installation. In the remaining months to the end of the year M2 was found to have more losses as compared to M1 as evidenced by the modules’ performance ratios. The directly water cooled module also showed an energy saving efficiency of 61%. A solar utilization of 47.93% was found for M2 while 8.77% was found for M1. Economically, the project was found to be viable and the payback period of the directly cooled module (M2) system was found to be 9.8 years. Energy economics showed that the system was more sensitive to the price changes and to the energy output as compared to other inputs such as operation and maintenance and years of operation. A generation cost of R0.84/kWh from the system was found and when compared to the potential revenue of R1.18 per kWh, the system was found to enable households to make a profit of 40.5 %. Use of such a system was also found to be able to contribute 9.55% towards carbon emission reduction each year. From these results, it was concluded that a directly cooled photovoltaic/thermal heating (PV/T) system is possible and that it can be of much help in terms of warm water and electricity provision.

Recent advancements in the development of high-efficiency multijunction solar cells have led to a renewed interest in the design and implementation of high concentration photovoltaic systems. With the emergence of novel materials and design structures, understanding the operation of multijunction solar cells has become a challenging task. Modeling and simulation hence play an important role in the analysis of such devices. In this dissertation, techniques for accurate optoelectrical modeling of concentrating photovoltaic systems, based on multijunction solar cells, are proposed. A 2-dimensional, distributed circuit model is proposed, parametrized to values obtained by numerical modeling of three multijunction cell designs, namely: a three-junction, lattice matched design, a three-junction lattice-mismatched, inverted metamorphic design, and a four-junction,lattice matched design. Cell performance for all the three designs is evaluated under both uniform and nonuniform illumination profiles at high concentrations and efficiency enhancement by optimizing finger spacing is proposed. The effect of luminescent coupling from higher bandgap subcells is also determined.Fresnel-lens based, refractive concentrating optical systems are modeled and optimized using an optical ray-tracing simulator at two different concentrations, with and without a secondary optical element. The corresponding optical efficiency, acceptance angle, and the degree of nonuniformity are determined for each optical system. An integrated approach,combining optical design with electrical modeling is proposed for optimizing the multijunction solar cell in tandem with the corresponding concentrating optics. The approach is validated by on-sun, acceptance angle measurements, using a three-junction,lattice-matched cell. Also, temperature effects are modeled and are experimentally validated for a three-junction, lattice-matched design. Experimental results with a single-junction, dilute-nitride cell, targeted for four-junction operation, are presented as well. A modified distributed circuit model is used for analysis of temperature effects in a four-junction solar cell, and the results under both uniform and nonuniform temperature profiles are presented. When implemented, the designs and their corresponding analyses, may result in new insights into the development of CPV systems, thereby enabling enhanced efficiencies at higher concentrations.

Because of global warming and the Paris agreement from 2015, countries need to switch their energy sources into clean sources. For some countries, like Perú, electricity produced from renewable energy sources is still a new technology. Its electricity demand depends entirely on traditional hydropower and thermal plants. Despite the high solar radiation in the coast and Andes (mountain range that passes through the entire South American continent), solar electricity is not developed and it fairly reaches the 1% of the national electricity production. Sweden, similarly, also produces its highest share on electricity from hydropower. However, nuclear energy and renewables like biomass and wind cover the rest of the demand, compared to thermal plants for Perú. On the other hand, most of the poor citizens of Perú live in the Andes, especially in remote villages, disconnected from the national grid and suffering from the cold during winter. Because their energy demand is low, it is not profitable for the electrical companies to give them electricity. The Swedish population, however, has 100% access to electricity. Despite that, high prices on maintaining the connection to the electricity network, and constant failures because of bad weather (more common nowadays because of global warming), brings the idea to disconnect from the grid and produce one´s own electricity, with, for example, photovoltaic systems. These problems occur not exclusively in Sweden. The work done on this thesis consists on a design of an off-grid solar PV system using batteries for energy storage, both for a remote farmer village in the high Andes in Perú (Ungalluta 2) and for a rural, low populated village in the center of Sweden (Gåsborn). The design is done manually and by software (PVSyst), with real life components, analyzing costs and the possibility to live entirely on solar power. The priority when choosing the components is the lowest price. For Ungalluta 2, with a demand of 17.1kWh/d (11 people), 13 PV modules and 1600Ah of battery capacity (Lead Acid) are needed, with a payback in approximately 40 years, renewing the PV panels on year 25 because of degradation. The initial investment is 21540EUR. For Gåsborn, with a demand of 36.44kWh/d (average Swedish family with children), 42 PV modules and 2850Ah of battery capacity (Lithium) are needed, with a negative payback, even increasing the PV modules to cover the entire year (more than 400). This is because the solar irradiation is quite low during winter and the load demand needs to be satisfied with considerable amounts of Diesel with a backup generator. After analyzing the results, it is possible and viable to build PV systems for the villagers in the Andes of Perú, but they will need monetary help of the government (high initial cost). For Sweden, it is not profitable to depend entirely on PV power. Other renewable sources must complement it, such as wind, to compensate the low solar irradiation and reduce the diesel consumption. / På grund av global uppvärmning och Parisavtalet från 2015, måste länderna byta sina energikällor till förnybara alternativ. För vissa länder, som Perú, är el från förnybara källor fortfarande en ny teknik. Dess elbehov beror helt och hållet på traditionella vattenkraftverk och termiska anläggningar. Trots den höga solinstrålningen vid kusten och i Anderna (bergskedja som går genom hela den sydamerikanska kontinenten) är el från PV inte utvecklad och den täcker knappt 1 % av den nationella elproduktionen. Sverige producerar på motsvarande sätt sin högsta andel av el från vattenkraftverk. Den resterande delen av elbehoven täcks av kärnkraftverk och förnybar energi som biomassa och vindkraft jämfört med de termiska anläggningarna i Perú. De flesta fattiga invånarna i Perú bor i Anderna, särskilt i avlägsna byar, bortkopplade från det nationella elnätet och blir således lidande under de kalla vintrarna. På grund av deras låga energibehov är det inte lönsamt för elföretag att förse dem med elektricitet. I Sverige är det dock annorlunda. Befolkningen har 100 % tillgång till elektricitet. Trots det är priserna för underhåll av anslutning till elnäten höga och återkommande strömavbrott på grund av dåligt väder är vanligt, särskilt på landsbygden. Detta ger upphov till idén om att koppla bort från nätet och producera egen elektricitet med exempelvis solcellssystem. Arbetet i denna uppsats består av en konstruktion av ett off-Grid system med solceller som använder batterier för energilagring, både för en by högt upp i Anderna i Perú (Ungalluta 2) och för en mindre befolkad by på landsbygden i mitten av Sverige (Gåsborn). Systemen är beräknade både för hand och med mjukvara (PVSyst) med verkliga komponenter för att analysera kostnaden och möjligheten att helt och hållet leva på solenergi. Vid val av komponenterna har lägsta pris varit en prioritering. För Ungalluta 2, med ett behov på 17.1 kWh/d (11 personer), behövs 13 solcellsmoduler och en batterikapacitet på 1600Ah (Bly-syra). Den ursprungliga investeringen uppgår till 21540 EUR och återbetalningstiden till 40 år där modulerna byts ut efter 25 år på grund av degradation. För Gåsborn, med ett behov på 36.44 kWh/d (genomsnittet for en Svensk familj med barn), behövs 42 solcellsmoduler och en batterikapacitet på 2850Ah (Litium) vilket ger en negativ återbetalning även om solcellsarean ökas för att täcka hela året (mer än 400 solcellsmoduler). Detta beror på att solinstrålningen är låg under vintern och att behovet måste täckas med stora mängder diesel och med en backupgenerator. Efter att ha analyserat resultatet är det möjligt och genomförbart att bygga solcellssystem för de byborna i Anderna i Perú men de kommer att behöva kapital från regeringen (hög initial kostnad). För Sverige, är det varken lönsamt eller miljövänligt att vara helt beroende på solenergi utan andra förnybara källor så som vind måste komplettera den för att kompensera den låga solinstrålningen och för att reducera dieselförbrukningen.

The use of solar photovoltaic (PV) systems have expanded rapidly the last decade and today’s market includes several different solar utilizations, where floating PV is one of them. Previous studies have shown how floating PV systems increase the PV efficiency and at the same time reduce the water evaporation. The purpose of this study is to evaluate and optimize energy solutions using floating PV systems for a shrimp farm cultivation in Thailand, where the technical, environmental and economic aspects will be included. The optimizations have been done in the open source model OptiCE, where genetic algorithm (AG) have been used to maximize the renewable reliability and minimize the Levelized Costs of Electricity (LCOE). In order to find the optimal renewable solution for the investigated shrimp farm, four scenarios have been compared considering different PV system combinations. The simulated results showed how the scenarios considering floating PV system generated a higher reliability than the scenarios considering ground-mounted PV system. The scenario considered tracking PV system increased the system´s renewable reliability compared to fixed PV system. However the shrimp farm is connected to the national electric grid or not will have a huge impact on the LCOE due to the low electric price and the implemented feed-in-tariff (FIT) program. The size of the installed PV capacity significantly affects the reliability results were the capacity of 200 kWp reaches a reliability of almost 100%. The optimal solution for the investigated shrimp farm to become independent is therefore to install a combined floating PV and battery storage system.

Driven by climate change and the impending depletion of fossil fuels, the UK Government has set the great challenge to UK builders to produce zero-carbon homes as of 2016. Due to a lack of experience the merits of integrating onsite micro renewable energy systems were largely unknown. Barratt Development PLC, UK's largest builder, set out in 2006 to investigate how these new building regulations can best be tackled. The key points to be investigated are: how much CO2 can be offset using renewable energy systems in standard homes and at what cost; how reliable are these systems; and how can their performance be improved? At the EcoSmart village several systems were tested under realistic conditions, including PV, Solar Thermal, Micro Wind Turbines, GSHPs and microCHP. The systems were tested over a 12-month period, integrated into standard Barratt homes, and running under near real-life conditions. Data was recorded from the test-site, including heat and electrical energy generation and consumption, temperature data and weather data. This data was used to establish the theoretical performance of the systems at the test site, and by doing so simple methods were found and tested that can be used by builders or architects to gain a better understanding of the expected performance of a particular system. The estimated energy generation was then compared to the measured performance. Detailed modelling and analysis of observations was carried out to provide explanations for any discrepancies, and based on this general recommendations were made on how the performance of the systems could be improved. Given the commercial drivers behind carrying out this research project, a high emphasis was given to financial implications of installing the systems. For this purpose payback periods and life-time savings were estimated, based on measured performance and other influences such as feed-in tariffs. This was also done for embodied energy and embodied carbon, as this will ultimately determine how the systems can help to fulfil the purpose of Government legislation, which is to reduce the carbon footprint of the UK domestic sector.

Submitted by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2017-07-11T14:11:33Z No. of bitstreams: 1 texto completo.pdf: 484351 bytes, checksum: 312994cb64033039a832571f86cbf2a3 (MD5) / Made available in DSpace on 2017-07-11T14:11:33Z (GMT). No. of bitstreams: 1 texto completo.pdf: 484351 bytes, checksum: 312994cb64033039a832571f86cbf2a3 (MD5) Previous issue date: 2001-07-06 / Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Trinta e três isolados de Xanthomonas campestris pv. campestris, obtidos de oito diferentes brássicas, provenientes de diferentes regiões do Brasil e do exterior, foram analisados com base em caracterizações bioquímica, patogênica, sorológica e genética, objetivando verificar a existência ou não de relacionamentos quanto à origem geográfica e ao hospedeiro. No estudo bioquímico, foram realizados 22 testes, além da avaliação da atividade de esterase, em que com base no tamanho do halo e utilizando o teste de Scott Knott no nível de 5% de probabilidade, obtiveram-se cinco grupos de similaridade. Avaliando a capacidade de produção de bacteriocina, verificou-se que três isolados apresentaram antibiose contra sete outros. Avaliou-se, também, a sensibilidade dos isolados a alguns antibióticos e, com base na análise de agrupamento, foi possível a observação de três grupos distintos: o primeiro constituído por quatro isolados resistentes a 11 ou mais antibióticos; o segundo grupo composto por um isolado resistente somente a três antibióticos; e o terceiro grupo composto pelos demais isolados. Na caracterização patogênica, foi realizada a inoculação cruzada, de forma que os 33 isolados foram inoculados artificialmente em sete diferentes brássicas. Desses, 14 não mostraram especificidade quanto aos hospedeiros, enquanto os 19 isolados restantes apresentaram relativo grau de especificidade, uma vez que não causaram doença em uma ou mais das brássicas inoculadas. Para a análise sorológica, foram obtidos sete antissoros, pelos quais se reconheceram, no teste de imunodifusão dupla, 32 dos 33 isolados estudados, além de mostrarem especificidade quanto ao reconhecimento dos isolados de X. campestris pv. campestris. Na caracterização molecular, realizou-se a extração do DNA total de todos os isolados, seguida de amplificação pela técnica do RAPD. Procedeu-se, também, à extração do DNA plasmidial. Para avaliação do comportamento dos 33 isolados de X. campestris pv. campestris de diferentes origens e hospedeiros, com relação às diferentes análises realizadas, foram efetuadas análises estatísticas univariadas, para a avaliação da atividade de esterase, e multivariadas, para as demais, bem como a análise conjunta de todos os resultados. Com base nos resultados das caracterizações bioquímica, patogênica e sorológica, não se observou correlação da variabilidade dos isolados estudados com a origem geográfica e o hospedeiro do qual foram obtidos. Isso pode ter sido devido à constante introdução de novos isolados de X. campestris pv. campestris nas áreas de plantio, por meio de sementes contaminadas. / Thirty-three isolates of Xanthomonas campestris pv. campestris, obtained from eight different Brassica species and originated from distinct geographic regions in Brazil and other countries, were analyzed in terms of their biochemical, pathogenic, serological and molecular properties, in order to determine whether there is a relationship between isolate variability and host or geographic origin. Twenty-two biochemical tests, besides the determination of sterase activity, were carried out for the biochemical characterization. Five similarity groups were identified using Scott- Knot s test at 5% probability. The analysis of bacteriocin production indicated that three isolates displayed antibiosis against seven other isolates. Sensitivity to several antibiotics was also evaluated. Using cluster analysis, three distinct groups were identified: the first group consisted of four isolates which were resistant to 11 or more antibiotics; the second group consisted of one isolate which was resistant to only one antibiotic; the third group consisted of all the other remaining isolates. For the pathogenic characterization, all 33 isolates were cross-inoculated onto seven different Brassica species. Fourteen isolates did not display host specificity. The remaining 19 isolates displayed a relative degree of host specificity, since they did not induce disease in one or more of the inoculated species. Seven polyclonal antisera were raised for the serological analysis. In immunodiffusion tests, 32 out of the 33 isolates tested were recognized by these antisera. The antisera specifically recognized isolates of X. campestris pv. campestris. For the molecular characterization, total DNA was extracted from each isolate and used as a template for RAPD reactions. Plasmid DNA was also extracted. Together, the data from the biochemical, pathogenic, serological and molecular analyses failed to indicate a relationship among the isolates, hosts and geographic origin. This could be due to the repeated introduction of new isolates of X. campestris pv. campestris into different geographic regions, via contaminated seeds.