Quartz crystal microbalances (QCM) are acoustic wave sensor systems which are used majorly for vapor and liquid sensing. QCM come under the category of thickness shear mode (TSM) sensors. There are several methods to study organic vapor sensing; the QCM method is the one that offers the highest sensitivity and generates the most data. Solubilities of benzene, dichloroethane, chloroform and dichloromethane in polyethylene glycol (PEG), polycaprolactone (PCL), and several di-block PEG/PCL copolymers at 298.15 K are reported. There are literature data available for most of the solvents in the homopolymers PEG and PCL but no literature data is available for the copolymers PEG (5000)/ PCL (1000), PEG (5000)/ PCL (5000) and PEG (1000)/ PCL (5000). Activity vs. weight fraction data was collected using a quartz crystal microbalance and are adequately represented by the Flory-Huggins model within experimental error. The data were reported using a QCM in a newly designed flow system constructed in the lab. The working apparatus consisted of a computer loaded with LabVIEW software for data selection, a quartz crystal cell, four bubblers for solvents, a phase lock oscillator, a frequency counter, and a temperature controlled vapor dilution system. In this thesis, the proof for a working model of the QCM apparatus was reported through a test-case. The test case consists of a study that details the solubility of the polyisobutylene (PIB) polymer in benzene at 298.15 K which was then compared to previous work published in the literature.

Cadmium Telluride (CdTe) is a leading thin film photovoltaic (PV) material due to its near ideal bandgap of 1.45 eV and its high optical absorption coefficient. Advancements in efficiencies of CdTe/CdS solar cells over the past few decades have come from improving the short circuit current (JSC) and Fill Factor (FF) but the Open Circuit Voltage (VOC) has been stagnant. Further improvements in efficiencies should come from increased VOC’s. VOC’s can be improved by increasing the acceptor concentration and minority carrier lifetime. Both these parameters can be controlled by manipulating the native defect concentration in CdTe which can be achieved by varying CdTe stoichiometry. In this study, a deposition system called Elemental Vapor Transport was used to vary the CdTe stoichiometry with an intent to change the native defect concentration and therefore pave way to increase acceptor concentration and lifetimes. Elemental cadmium and tellurium were heated in dedicated zones and their vapors were transported to the substrate using a carrier gas. By varying the temperatures and flowrates of the carrier gas through the zones, the gas phase Cd/Te ratio was varied to deposit Cd-rich, Te-rich and stoichiometric films. Structural properties were investigated using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and Transmission Electron Microscopy (EDS). Electrical characterization of completed devices was carried out by Current-Voltage (J-V), Capacitance-Voltage (C-V), and Spectral Response (SR) and Deep Level Transient Spectroscopy (DLTS) measurements. Cd-rich films showed smaller grain sizes and lesser degree of preferential orientation. Te-rich films showed increased acceptor concentration and carrier lifetimes and solar cells fabricated using these films showed higher VOC’s compared to Cd-rich and stoichiometric films .Higher degree of CdTe-CdS mixing was observed at the interface for films deposited at increased substrate temperatures.

This study focuses on the growth and characterization of epitaxial InAs and InAs1-xSbx. Layers are grown on InAs, GaAs and GaSb substrates by metalorganic vapour phase epitaxy, using trimethylindium, trimethylantimony and arsine as precursors. The growth parameters (V/III ratio, Sb vapour phase compositions) are varied in the temperature range from 500 ºC to 700 ºC, in order to study the influence of these parameters on the structural, optical and electrical properties of the materials. The layers were assessed by X-ray diffraction, electron and optical microscopy, photoluminescence and Hall measurements. Furthermore, the influence of hydrogenation and annealing on the electrical and optical properties of GaSb was investigated. It is shown that the growth temperature and the V/III ratio play a vital role in the resulting surface morphology of homoepitaxial and heteroepitaxial InAs layers. Growth at low temperatures is found to promote three-dimensional growth in both cases, with improvements in the surface morphologies observed for higher growth temperatures. All the investigated epilayers are n-type. It is shown that the electrical properties of heteroepitaxial InAs epilayers are complicated by a competition between bulk conduction and conduction due to a surface accumulation and an interface layer. The low temperature photoluminescence spectra of homoepitaxial InAs are dominated by two transitions. These are identified as band-to-band/excitonic and donor-acceptor recombination. The incorporation efficiency of antimony (Sb) into InAs1-xSbx is dependent on the growth temperature and the V/III ratio. Under the growth conditions used in this study, the incorporation efficiency of Sb is controlled by the thermal stability of the two constituent binaries (i.e. InAs and InSb). Changes in the low temperature photoluminescence spectra are detected with increasing x. From temperature and laser power dependent measurements, the highest energy line is attributed to band-to-band/excitonic recombination, while the peak appearing approximately 15 meV below this line is assigned to donor-acceptor recombination. The origin of an additional “moving” peak observed for higher Sb mole fraction x is tentatively attributed to quasi-donor-acceptor-recombination, arising from increased impurity/defect concentrations and a higher compensation ratio in the material. However, the unusual behaviour of this peak may also be ascribed to the presence of some degree of ordering in InAsSb. The exposure of a semiconductor to a hydrogen plasma usually leads to the passivation of shallow and deep centres, thereby removing their electrical and optical activity. In this study, the passivation and thermal stability of the native acceptor in p-type GaSb is also investigated. It is shown that this acceptor can be passivated, where after improvements in the electrical and optical properties of GaSb are observed. Upon annealing the passivated samples above 300 °C, the acceptor is reactivated.

Metal sulfide thin films are important class of materials which have applications in photovoltaics, microelectronics and displays. Chemical vapour deposition (CVD) is well known method for the deposition of high quality thin films. Very few classes of single source precursors (eg: dithiocarbamates, xanthates) were successful for the deposition of good quality metal sulfide films by MOCVD. This limited choice was due to the difficulties of finding precursors with suitable physico-chemical properties. Hence, it is important to develop precursors with suitable volatility, solubility and being able to deposit films with little or no contamination. This work describes the synthesis of a series of metal (Fe, Co, Ni, Zn, Cd) complexes of thio- and dithio-biuret ligands, their structural and spectroscopic characterization and thermal decomposition. The complexes were used as single source precursors for the deposition of iron, cobalt, nickel, zinc, cadmium and zinc cadmium sulfide thin films by AACVD. The effect of alkyl groups, coordinating atoms, deposition temperatures on phases and morphology of the films were studied. The deposited films were characterised by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and atomic force microscopy (AFM). The complex [Fe(SON(CNiPr2)2)3] gave hexagonal troilite FeS films with small amount of tetragonal pyrrhotites Fe1-xS at 300 °C, whereas only troilite FeS was deposited at 350, 400 or 450 °C. Complexes [Fe2(µ-OMe)2 (SON(CNEt2)2)2] and [Fe(SON(CNEt2)2)3] deposited a mixture of hexagonal troilite FeS and cubic pyrite FeS2 films at all temperatures. [Fe(SON(CNMe2)2)3] deposited very thin films of FeS at all temperatures as troilite. Complexes [Co(N(SCNMe2)2)3] and [Co(N(SCNEt2)2)3] deposited hexagonal Co1-xS films at all temperatures of 350-500 °C, whereas [Co(SON(CNiPr2)2)2] gave mixture of cubic and hexagonal Co4S3 films at 280-400 °C. Thiobiuret complex [Ni(SON(CNMe2)2)2] gave orthorhombic Ni7S6. Complexes [Ni(SON(CNMe2CNEt2))2] and [Ni(SON(CNEt2)2)2] gave mixtures of hexagonal Ni17S18 and orthorhombic Ni7S6. In contrast, [Ni(SON(CNiPr2)2)2] gave orthorhombic Ni9S8. Dithiobiuret complexes [Ni(N(SCNMe2SCNEt2))2] and [Ni(N(SCNEt2)2)2] gave hexagonal NiS1.03 at 360 and 400 °C, orthorhombic Ni7S6 phase at 440 and 480 °C. The zinc complexes [Zn(N(SCNMe2)2)2] and [Zn(SON(CNiPr2)2)2] deposited cubic ZnS at 300 and 350 °C, whereas at 400 and 450 °C hexagonal ZnS were apparent [Zn(N(SCNEt2)2)2] gave hexagonal ZnS films at all deposition temperatures. Cadmium complexes [Cd(N(SCNMe2)2)2], [Cd(N(SCNEt2)2)2] and [Cd(SON(CNiPr2)2)2] gave hexagonal CdS films at all deposition temperatures.

Orientadores: Florencia Cecilia Menegalli, Maria Isabel Rodrigues / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T08:01:10Z (GMT). No. of bitstreams: 1 Vissotto_FernandaZaratini_D.pdf: 6786611 bytes, checksum: dffef14262649a8cbe2a7daad1cf4d46 (MD5) Previous issue date: 2014 / Resumo: Os achocolatados em pó são formulados com a mistura de cacau, açúcar, maltodextrina e aromas, podendo conter derivados lácteos. Para se obter uma adequada reconstituição em líquidos, os achocolatados são submetidos aos processos de lecitinação (adição de um agente tensoativo: lecitina de soja) e aglomeração com vapor. Um dos objetivos desse estudo foi o de avaliar os efeitos das variáveis do processo de aglomeração com vapor (pressão do vapor, temperatura do secador rotativo, vazão de sólidos da alimentação e frequência de rotação do secador) sobre as características físicas e físico-químicas de achocolatados em pó. A aglomeração com vapor levou a um aumento do diâmetro médio de partículas, sendo mais pronunciado no produto formulado com o açúcar moído. O processo foi responsável pelo escurecimento e redução da umidade dos achocolatados, além da diminuição dos tempos de molhabilidade. Adicionalmente foi caracterizada a morfologia dos grânulos de achocolatado, obtidos em diferentes condições operacionais do aglomerador (máxima, média e mínima), utilizando os descritores de tamanho e forma. Os resultados mostraram que não existe diferença entre os descritores de forma e quanto aos descritores de tamanho verificou-se diferença entre as condições de processo para grânulos maiores que 600 ?m. Concluiu-se que os grânulos de achocolatado aglomerados apresentaram formato alongado. Foram também determinadas as transições de fase e as temperaturas de transição vítrea (Tg) de achocolatados em pó e dos seus principais constituintes. Durante a aglomeração com vapor a alta temperatura levou o açúcar moído a uma condição acima da sua Tg, passando a ser esse componente um veículo para a granulação. A Tg da maltodextrina é pequena em atividades de água elevadas (Tg= - 4,9 °C; Aa= 0,843), o que também a torna um veículo para o processo de aglomeração. No cacau em pó alcalino foi observada a fusão da manteiga de cacau (aparecimento das formas polimórficas ?v e ?). Para o achocolatado lecitinado verificou-se que a Tg aumenta com o incremento da atividade de água do meio, portanto para esse tipo de produto a água, ao ser adsorvida, não consegue interagir com o material, não sendo verificado o efeito plasticizante. Para o achocolatado aglomerado com vapor verificou-se que a Tg diminuiu com o aumento da atividade de água do meio (efeito plasticizante). A evolução do caking dos constituintes dos achocolatados mostrou que o cacau em pó apresentou baixa higroscopicidade (pequeno aumento do ângulo de repouso com o tempo), pequena formação de aglomerados e a ausência do caking. A medida da força de compressão dos agregados formados mostrou que a sacarose formou pontes mais rígidas entre as partículas que a maltodextrina. Foi também monitorada a estabilidade de achocolatados em pó lecitinados e aglomerados com vapor, estocados a 25 e 35 °C, numa umidade relativa de 84%, buscando-se simular um clima quente e úmido (região norte do Brasil). Ao longo do tempo, verificou-se aumento do ângulo de repouso e escurecimento dos produtos. O achocolatado lecitinado mostrou-se mais susceptível ao empedramento que o aglomerado, com a formação de grumos a partir do 63° dia de armazenamento / Abstract: Cocoa beverage powders consist of a mixture of cocoa, sugar, maltodextrin, flavors, and may contain dairy products. To obtain products with adequate reconstitution in liquids, the cocoa beverage powders are subjected to the processes of lecithination (addition of the surfactant soy lecithin) and steam agglomeration. One objective of this study was to evaluate the effects of the main variables of the steam agglomeration process (vapor pressure, temperature of rotary dryer, solid feed rate and dryer rotation frequency) on the physical and physicochemical characteristics of cocoa beverage powders. The steam agglomeration led to an increased average particle diameter, being more pronounced in the product formulated with granulated sugar. The process was responsible for powder darkening, reduction of the product¿s moisture and decrease in the wettability. Additionally, the morphology of the cocoa beverage powder granules was characterized in different operating conditions of the steam agglomerator (maximum, average and minimum) using the descriptors of size and shape. There were no differences between the shape descriptors and as to the size descriptors there were differences in the process conditions studied for the granules of size above 600 ?m. It was observed that the steam agglomerated cocoa beverage granules had a more elongated shape. It was also determined phase transitions and the glass transition temperature (Tg) of cocoa beverage powders and the main constituents of these products. During the steam agglomeration, the high temperature led the granulate sugar to a condition above its Tg, making this ingredient a granulation vehicle. The Tg of maltodextrin is small at higher water activities (Tg = - 4.9 °C, aw = 0.843), which makes this ingredient a vehicle for the agglomeration process. For the alkaline cocoa powder the phase transition observed is the melting of the cocoa butter with the appearance of polymorphic forms ? and ?v. For the lecithinated cocoa beverage powder, it was verified that the Tg increases with the increasing of the water activity, which leads to the conclusion that for this type of product the adsorbed water cannot interact with the material, and the plasticizing effect is not noted. For the steam agglomerated cocoa beverage powder it was observed that the Tg decreases with increasing water activity (plasticizing effect). The evolution of the caking for the constituents of cocoa beverage powders showed that the cocoa powder had low hygroscopicity (small increase of the repose angle with time), little formation of granules and the absence of caking. The measurement of the compression strength of the aggregates showed that sucrose formed bridges more rigid between the particles than maltodextrin. Stability of lecithinated and steam agglomerated cocoa beverage powders stored at 25 and 35 °C, in a relative humidity of 84%,was also monitored, in order to simulate hot and humid climates (like northern Brazil). Overtime, it was observed increase of the repose angles and products darkening. The lecithinated cocoa beverage powder was more susceptible to caking than the steam agglomerated product, with the formation of lumps from the 63th day of storage / Doutorado / Engenharia de Alimentos / Doutora em Engenharia de Alimentos

This study attempted to determine if an excessive amount of 1,1,1 - Trichloroethane was released into the air, the acute effects of exposure and the cause(s) of excessive use. The types of degreasing equipments which were tested in this study are straight vapor and the vapor spray machines. The instruments utilized to obtain the data for this study are Gastech Haline Detector, Organic Vapor Monitor Badge and Personal Sampling Pump. Readings were taken on three different tanks. The data accumulated by this study were obtained during actual cleaning operation. During testing, increased exposure was detected due to exceeding the rate of removal, downward drafts were blowing right over the top of a degreaser and, in some cases, poor general ventilation caused solvent vapor to be blown out of the tank and into the workers' breathing zone, affecting excessive vapor drag out and solvent loss. The results show that, since the characteristics of solvent 1,1,1 - Trichloroethane are well suited to vapor degreasing requirements, by using proper procedures and maintenance, 1,1,1 - Trichloroethane emission during vapor degreasing can be controlled at levels well below the industrial hygiene standard established by OSHA for safe and healthful conditions.

Orientador : Roger Josef Zem / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-09-11T21:00:25Z (GMT). No. of bitstreams: 1 Faria_SergioHenriqueBernardode_D.pdf: 4922037 bytes, checksum: 89a2b8549eebabf31b90e85dd94e0dd7 (MD5) Previous issue date: 2003 / Resumo: Destilação é um dos processos de separação que mais consome energia. Isto é motivação importante para o estudo de diferentes configurações de sistemas de destilação, com o objetivo de obter-se processos mais eficientes, que desperdicem menos energia e causem menor impacto ambiental. No estudo de diferentes configurações de sistemas de destilação, necessariamente tenta-se encontrar a combinação ótima entre os fatores: Número de estágios, razão de refluxo, condição térmica da alimentação, estágio de alimentação e a utilização de trocadores intermediários. Neste trabalho, um método para encontrar esta combinação ótima, do pronto de vista da termodinâmica, é proposto. O método se baseia na análise de colunas de destilação através do estudo de perfis de perdas de exergia. O perfil de perdas de exergia, montado a partir de balanços de exergia em cada estágio de uma coluna de destilação, representa a distribuição de forças motrizes ao longo da coluna. É a análise do formato do perfil que permite identificar mudanças necessárias na coluna para que a sua eficiência aumente. Os testes feitos para colunas com o sistema °metanol/água, mostraram que os perfis obtidos efetivamente representam a distribuição de forças motrizes na coluna, desde que as propriedades entalpia, entropia e energia de Gibbs, envolvidas nos cálculos, sejam consistentes entre si. Para isto, foi provado que é necessário considerar-se os valores de excesso destas propriedades. Estendendo um pouco o trabalho, análises mais detalhadas mostraram que é possível desprezar-se os valores de entalpia de excesso, obtendo ainda assim perfis coerentes. Este procedimento tem a vantagem de permitir que o método seja estendido a sistemas muIticomponentes. Por fim, o perfil de perdas de exergia foi utilizado para direcionar modificações em duas colunas (acetona/água e etanol/água), com o objetivo de aumentar a eficiência termodinâmica destas colunas. Foi constatado que as colunas finais obtidas são termodinamicamente mais eficientes que as originais / Abstract: The most frequently used method of separating fluid mixtures is by distillation, which uses significant amounts of energy. For this reason, the study of column design modifications with respect to energy consumption, has been the subject of many recent works concerning the energy efficiency of distillation columns. Column design modification involves options such as different number of stages, reflux ratios, feed stage location, feed condition and the benefit of using side-condensers or/and side reboilers. In this work a new procedure to find the best combination of these options, from a thermodynamic point of view is presented. In this method, exergy loss profiles are used to analyse different columns layouts. The exergy loss profile is obtained from a stage-to-stage exergy balance and represent the distribution of driving forces in the column. Critical analysis of profile shapes identifies necessary column modifications to lead to higher column efficiency. The methodology was tested to a separation of a high nonideal mixture (methanol/water), concluding that exergy loss profiles can represent the distribution of driving forces in the column. However, to ensure thermodynamic consistency, when dealing with nonideal systems excess properties cannot be ignored. Detailed studies showed that it is possible to simplify the method, ignoring excess enthalpy contribution and still ensure reasonable thermodynamic consistency. This modification allows the method to be applied to multicomponent systems. Finally, exergy 10ss profiles were used to identify suitable column modifications for acetone/water and ethanol/water splits. Results showed that the columns obtained after modifications are thermodynamically more efficient / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

A geração química de vapor (CVG) e a geração fotoquímica de vapor (PVG) são técnicas analíticas empregadas na conversão do analito, presente na fase condensada, em uma espécie volátil, previamente a sua introdução no sistema de detecção. Neste trabalho foram desenvolvidos procedimentos analíticos para a determinação de Hg e Se em amostras biológicas por técnicas de geração de vapor acopladas à espectrometria de absorção atômica com forno de grafite (GF AAS). A determinação exata e precisa de Hg em amostras de peixe foi possível após a solubilização em hidróxido de tetrametilamônio e adição de n-propanol, como composto orgânico de baixo peso molecular, e detecção por PVG-GF AAS. O método analítico desenvolvido com o emprego da técnica de PVG para a determinação de Se em água de coco por GF AAS resultou em limites de detecção e quantificação de 0,65 μg L-1 e 2,2 μg L-1, respectivamente, os quais foram semelhantes aos obtidos por CVG. Os métodos desenvolvidos para a determinação de Hg e Se por PVG-GF AAS em amostras biológicas são sensíveis, livres de interferência espectral, de baixo custo e representam uma alternativa viável a CVG. / Chemical vapor generation (CVG) and photochemical vapor generation (PVG) are analytical techniques used to convert the analyte into a volatile species in liquid phase, before the introduction into the detection system. In this study, analytical procedures for the determination of Hg and Se in biological samples by vapor generation techniques coupled to graphite furnace atomic absorption spectrometry (GF AAS) were developed. Accurate Hg determination in fish samples was possible after a solubilization in tetramethylammonium hydroxide and adding n-propanol, as low molecular organic compound, using PVG-GF AAS. The developed method for Se determination in coconut water with PVG-GF AAS have resulted in limits of detection and quantification of 0,65 μg L-1 and 2,2 μg L-1, respectively and that were similar with those obtained with CVG. The developed methods for Hg and Se determination in biological samples using PVG-GF AAS are sensitive, free of spectral interference, low-cost, and are a feasible alternative for CVG.

[ES] En la presente tesis se ha desarrollado un modelo dinámico de simulación de secadoras de ropa asistidas por ciclo de compresión de vapor enfocado a asistir en el desarrollo de producto basado en simulación. Este modelo ha sido creado en Modelica, lenguaje de programación orientado a objetos con una interfaz gráfica con posibilidad de programación por bloques, permitiendo cierta flexibilidad en el modelado de distintos sistemas. El enfoque de modelado ha sido crear un modelo basado en aproximaciones teóricas, en búsqueda de obtener una herramienta de simulación robusta y capaz de predecir el comportamiento de nuevas configuraciones de la secadora de ropa antes de tener información empírica. No obstante, debido a la complejidad del sistema modelado, es preciso llevar a cabo un proceso de ajuste para que la predicción del funcionamiento del sistema sea lo más realista posible. Se ha llevado a cabo una batería de ensayos de caracterización del sistema registrando temperaturas, presiones, humedades relativas, caudal de condensado y consumo de energía eléctrica para tener una base de datos adecuada para el ajuste. Además, también se ha llevado a cabo una caracterización experimental del circuito de aire de la secadora para poder modelar correctamente las fugas e infiltraciones en el mismo. Con estos datos, se han ajustado los parámetros de ajuste necesarios en el modelo, y posteriormente se ha realizado una validación de los resultados de este, comparándolos con un ensayo. También se ha llevado a cabo un análisis de sensibilidad de un parámetro de ajuste, para comprobar la variación en los resultados que produce una incertidumbre del 10% en la determinación de este. Finalmente se ha realizado un caso de estudio en que se añade a la secadora de ropa modelada una resistencia eléctrica. El resultado de este estudio ha demostrado la utilidad de la herramienta desarrollada para predecir el comportamiento del sistema modelado tras realizar modificaciones al mismo. / [CAT] En la present tesi s'ha desenvolupat un model dinàmic de simulació d'eixugadores de roba assistides per cicle de compressió de vapor enfocat a donar suport en el desenvolupament de producte basat en simulació. Aquest model ha sigut creat en Modelica, llenguatge de programació orientat a objectes amb una interfície gràfica que possibilita la programació per blocs, permetent certa flexibilitat en el modelatge de diferents sistemes. El model s'ha basat en aproximacions teòriques, tractant d'obtenir una eina de simulació robusta i capaç de predir el comportament de noves configuracions de l'eixugadora de roba abans de tindre informació empírica. No obstant això, degut a la complexitat del sistema modelat, cal dur a terme un procés d'ajust per tal que la predicció del funcionament del sistema siga la més realista possible. S'ha dut a terme una bateria d'assajos de caracterització del sistema registrant temperatures, pressions, humitats relatives, cabal de condensat i consum d'energia elèctrica per tal de tindre una base de dades adequada per a l'ajust. A més, també s'ha caracteritzat experimentalment el circuit d'aire de l'eixugadora amb la finalitat de modelar correctament les fugues i infiltracions. Amb aquestes dades, s'hi han obtingut els valors dels paràmetres d'ajust necessaris en el model i, posteriorment, s'ha realitzat una validació dels resultats d'aquest, comparant-los amb un assaig. També s'ha dut a terme una anàlisi de sensibilitat d'un dels paràmetres d'ajust, per a comprovar la variació en els resultats que produeix una incertesa del 10% en la determinació d'aquest. Finalment s'ha realitzat un cas d'estudi en què s'afegeix una resistència elèctrica a l'eixugadora de roba modelada. El resultat d'aquest estudi ha demostrat la utilitat de l'eina desenvolupada per a predir el comportament del sistema modelat després de realitzar modificacions a aquest. / [EN] In the present thesis a dynamic model of simulation of clothes dryers assisted by vapor compression cycle focused on assisting in the development of simulation-based product has been developed. This model has been created in Modelica, an object-oriented programming language with a graphical interface with the possibility of programming by blocks, allowing some flexibility in the modelling of different systems. The modelling approach has been to create a model based on theoretical approaches, in search of obtaining a robust simulation tool capable of predicting the behaviour of new configurations of the clothes dryer before having empirical information. However, due to the complexity of the modelled system, it is necessary to carry out an adjustment process so that the prediction of the operation of the system is as realistic as possible. A battery of system characterization tests has been carried out recording temperatures, pressures, relative humidity, condensate flow rate and electric power consumption to have a suitable database for the adjustment. In addition, an experimental characterization of the air circuit of the dryer has also been carried out in order to correctly model leaks and infiltrations in it. With these data, the necessary adjustment parameters have been adjusted in the model, and subsequently a validation of the results has been made, comparing them with a trial. A sensitivity analysis of an adjustment parameter has also been carried out to verify the variation in the results that produces an uncertainty of 10% in the determination of this. Finally, a case study was carried out in which an electrical resistance was added to the modelled clothes dryer. The result of this study has demonstrated the utility of the tool developed to predict the behaviour of the modelled system after making modifications to it. / Barceló Ruescas, F. (2019). Desarrollo de un modelo de secadora de ropa doméstica asistido por ciclo de compresión de vapor y posterior validación [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/125707 / TESIS

A higher frequency radio channel both increase the possible data rate and de- crease the required antenna size to efficiently transmit data. Higher frequency also introduce larger weakness to signal loss due to atmospheric effects. Al- phasat satellite conduct experiments for future use of higher frequencies by the Aldo Paraboni Payload. Budapest University of Technology have receiv- ing antennas for both transmitted Alphasat signals in the Ka band and Q band. Meteorological surface data is also gathered in close proximity of the receiving antennas. The relationship between the meteorological data and attenuation on the received signal is studied. A focus lies on the effects of water vapor and clouds.  International Telecommunication Union prediction methods for clouds and atmospheric gases are applied on the meteorological data. This provide a foundation for the analysis of received attenuation on the Q band signal at frequency 39,402 GHz. The analysis aim to investigate if there is any rela- tionship between surface meteorological data and atmospheric effects such as cloud and atmospheric gases. Cross-correlation was used to find similarities between the parameters.  The analysed data is over the month of April 2018. During this month seven different rain events were indicated by the rain rate tipping bucket. These regions showed strong influence of rain on the surface temperature and hu- midity was used to identify other regions with no rain characteristics. Only four out of 16 regions above 2,5 dB had no characteristics similar to rain with four other regions showing indistinguishable source. These eight regions were most promising of being caused by cloud and atmospheric gases. The large quantity of attenuation events below 2,5 dB made further manual analysis difficult. ITU methods predicted a maximum attenuation of 3 dB for clouds and atmospheric gases. Future work could improve analysis on attenuation events below 2,5 dB by pattern recognition with the characteristics found in this work.