Submitted by Izabel Franco (izabel-franco@ufscar.br) on 2016-10-06T13:50:45Z No. of bitstreams: 1 TeseMM.pdf: 4347312 bytes, checksum: a5a64729ea719b0ac57b31c2cdeeb425 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-20T16:14:11Z (GMT) No. of bitstreams: 1 TeseMM.pdf: 4347312 bytes, checksum: a5a64729ea719b0ac57b31c2cdeeb425 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-20T16:14:17Z (GMT) No. of bitstreams: 1 TeseMM.pdf: 4347312 bytes, checksum: a5a64729ea719b0ac57b31c2cdeeb425 (MD5) / Made available in DSpace on 2016-10-20T16:14:23Z (GMT). No. of bitstreams: 1 TeseMM.pdf: 4347312 bytes, checksum: a5a64729ea719b0ac57b31c2cdeeb425 (MD5) Previous issue date: 2016-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / In this study, we present the production and characterization of a novel binary glass system: (100-x)SbPO4-xGeO2 where x = 30, 40, 50, 60, 70, 80 and 90 mol %. The dependence of GeO2 content on thermal, structural and optical properties were investigated by thermal analysis (DSC), Raman spectroscopy, UV-Visible absorption, infrared transmittance and M-lines techniques. Glass transition temperatures (Tg) shows an almost constant value around 400 °C when GeO2 content was increased. Thermal stability (ΔT = Tx-Tg) increases almost linearly with GeO2 content reaching a maximum value (300 °C). Ions Er3+ and Yb3+ were further incorporated into system SG in different proportions. Infrared and up-conversion emission processes were investigated. The emission spectra in the infrared region showed that the incorporation of Yb3+ ions into the glass composition increases the emission intensity at 1538 nm (4I13/2  4I15/2). The up-conversion processes showed a higher intensity emission at 522 nm and 544 nm (green) and 652 nm (red) regions and the emission mechanism has been the same as proposed in several works in literature. Finally, the glass sample showing the highest emission intensity at 1538 nm was chosen for micromachining using femtosecond laser. The waveguides having the lowest propagation losses were used for the optical internal gain proceeds. The best result obtained for internal gain at 1535 nm was around 1.7 dB/cm and this value is in agreement with other glass systems based on germanium and phosphates glasses present in literature. / Neste estudo, foi realizado a preparação e caracterização do sistema vítreo: (100-x) SbPO4-xGeO2 (SG), onde x varia entre 30 e 90% em mol. A dependência da concentração de GeO2 nas propriedades térmicas, ópticas e estruturais foram estudadas. O comportamento térmico foi investigado através da análise térmica (DSC), enquanto as propriedades estruturais foram estudadas por espectroscopia de espalhamento Raman. As propriedades ópticas foram avaliadas usando as espectroscopias na região do UV-Vis, infravermelho e M-Lines. No sistema SG a temperatura de transição vítrea (Tg) apresenta uma pequena variação e se encontra por volta de 400 °C quando a concentração de GeO2 foi alterada. O parâmetro de estabilidade térmica (ΔT = Tx-Tg) aumenta quase linearmente com o aumento da quantidade de GeO2, alcançando um valor máximo de 300 °C. Para o sistema SG foram incorporados ainda íons Er3+ e Yb3+ em diferentes proporções e as emissões na região do infravermelho e os processos de conversão ascendente de energia (upconversion) foram investigados. Os espectros de emissão na região do infravermelho mostram que a incorporação de íons Yb3+ na composição química do vidro, aumenta a intensidade de emissão em 1538 nm (4I13/2  4I15/2). Os processos de up-conversion mostram emissões de alta intensidade na região do verde (522 e 544 nm) e vermelho (652 nm), e os mecanismos das emissões foram estudados e propostos. Por fim, a amostra com a maior intensidade de emissão em 1538 nm foi escolhida para a realização da microfabricação de guias ópticos, usando lasers de femtossegundo. Os guias de onda que apresentaram as menores perdas por propagação, foram utilizados para as medidas de amplificação óptica.

The present work reports a study related to the potential improvement of the energy performances of a heat pump based heating system for a Swedish single-family house. The analysis is focused on the design of new rule-based control strategies which employ perfect predictions of weather forecast and human behaviour information. In particular, the considered signals are the outdoor temperature, the solar radiation, the internal gain due to inhabitants’ activities and the Domestic Hot Water (DHW) consumption. The study is performed by means of the TRNSYS® simulation software in which the model of the heating system is implemented. More specifically, it is composed by a Ground Source Heat Pump (GSHP) unit, a stratified storage tank of three hundred litres and the building element. The performances of the developed control logics are evaluated using a degree-minute on/off controller as reference case. The results show that the improved control logics yield to an increase of the energy efficiency of the system as well as an enhancement of the indoor and DHW temperatures stability. / EffSys Expand P18: Smart Cotnrol Strategies for Heat Pump Systems

The present work deals with a study related to the analysis of weather data for heat pump system control improvement based on both instantaneous and forecasted measurements. In particular, the analysis is firstly focused on the comparison of multiple weather sources for the assessment of weather forecast uncertainties, based on the evaluation of errors in prediction with respect to measured values. Afterwards, the results are compared with the ones related to persistent predictions methods that assumes the state of the atmosphere to be stationary over the considered time interval. The development and testing of a new preliminary “predictive” control logic is also performed, thanks to TRNSYS numerical simulations, considering a typical Swedish single-family house located in Stockholm, with the aim of optimizing the operation of a heat pump heating system based on solar radiation prediction to yield energy and cost savings. With the crucial points of accuracy and precision by which the local weather processes can be predicted, the same TRNSYS model is run accounting for perfect predictions and solar radiation forecasted values. From this perspective, given the fact that forecast of solar radiation are usually absent within most of the weather forecast datasets, a deep analysis is also performed on hourly measurements of solar radiation to define a simple and effective methods to calculate hourly solar radiation predictions. The results show that, when a short-time horizon is considered, persistent predictions allow to provide forecasts with a sufficient accuracy, whereas, when longer horizon time are considered, significantly higher errors are calculated when persistent prediction techniques are adopted. Independently of the uncertainties considered for weather forecasts, the improved control logics demonstrated a potential for energy savings and improvements in indoor temperature stability when compared with a reference case of variable speed compressor with PID controller. / EffSys Expand P18: Smart Cotnrol Strategies for Heat Pump Systems