L'eau joue un rôle fondamental dans la photochimie du milieu interstellaire (MIS), à travers la formation d'espèces très réactives comme OH. Les radicaux OH peuvent par la suite interagir avec d'autres molécules hydrogénées pour reformer H2O par abstraction d'hydrogène: R-H + OH → R* + H2O. Dans le cadre de ce travail de thèse, nous avons étudié l'influence des photons VUV sur des analogues de glace interstellaire. Nous montrons que l'incorporation d'une petite quantité d'eau dans NH3 et CH4 glaces augmente considérablement la formation de radicaux réactifs comme NH2 et CH3 pendant le processus de photolyse et que le chauffage des glaces binaires irradiées telles que NH3-H2O et CH4-H2O conduit à la formation de NH2OH et d'espèces alcooliques plus complexes comme le propanol et le métoxyméthanol. Nous avons également entamé d'autres études en parallèle sur le l'évolution thermique des glaces de NH2OH d'une part et la formation de propanol par voies énergétiques (irradiation VUV) et non énergétique (réaction d'addition H) d'autre part afin de tenter d'expliquer la non-détection des ces espèces organiques dans le milieu interstellaire. L'étude des glaces mixtes irradiées NH3-CH4-H2O a montré la formation à basse température d'espèces plus exotiques en combinant les spectrométries IR et de masse. Nous avons réussi à identifier des composés organiques très complexes déjà détectés ou activement recherchés dans le MIS. / Water plays a fundamental role in the photochemistry of the interstellar medium (ISM), through OH radical formation. OH radicals can interact with other H-containing species to form H2O through a hydrogen abstraction reaction: R-H + OH → R* + H2O. In this work, we have investigated the VUV processing on different interstellar ice analogs. We show that the incorporation of small amount of water in NH3 and CH4 ices greatly increases the formation of reactive NH2 and CH3 radicals during the photolysis processing. Thermal treatments of irradiated NH3-H2O and CH4-H2O ices lead to the formation of NH2OH and larger alcoholic species such as propanol and metoxymethanol. Further studies of thermal processing of NH2OH ice and formation of propanol through energetic (VUV irradiation) and non-energetic (surface H-addition reaction) processing were carried out in the context of this thesis in order to try explaining their non-detection in the interstellar medium. The study of the irradiated mixed NH3-CH4-H2O ices showed the formation of more exotic species by combining the IR and mass spectrometries. We managed to identify very large complex organic compounds already detected or tensively sought in the ISM.

This thesis contains the results of optical flame emission measurements of the Vulcain 2.1engine and the plasma emission spectroscopy of the Lumen Project engine. The plume spectroscopyis analyzed, ordered and studied in detail to offer the best possible molecular composition.The main focus relied on the hydroxide radical, blue radiation and other moleculesanalysis of the intensities encountered during the tests. The plasma emission spectroscopy isfocused on the determination of the plasma temperature value in LIBS measurements. Thehydrogen plasma temperature determination of the local thermodynamic equilibrium, followedby the carbon and sequentially oxygen plasma is obtained. The quality of the LTE isto be determined to judge the truthworthness of the determined temperatures. Both the testsare analyzed thanks to the use of spectrographs, cameras and dedicated software for opticalapplications. The results related to the Vulcain 2.1 LOX/LH2 engine showed the evolutionof the plume in different ROF or pressure variations. Furthermore, the results of the LumenProject LOX/methane engine led to the determination of the plasma temperatures and a firstestimation of the LTE quality. / Die vorliegende Arbeit präsentiert die Ergebnisse der Abgasstrahlspektroskopie des H2/LOXVulcain 2.1 Triebwerks und der Zündplasma Spektroskopie des CH4/LOX Triebwerks desLUMEN Projektes. Die Abgasstrahlspektroskopie wurde analysiert und im Detail untersuchtum die am besten passende molekulare Zusammensetzung herauszuarbeiten. DasHauptaugenmerk liegt dabei auf dem Hydroxyl- Radikal, der Blauen Strahlung und molekularerIntensitätsanalyse. Bei der Zündplasmaanalyse liegt der Fokus auf der Bestimmungdes LTE Zustands (Lokales thermodynamisches Gleichgewicht) in LIBS. Die Temperaturdes Wasserstoff-, Kohlenstoff und Sauerstoffplasmas wird herangezogen, um die Qualitätdes LTE Zustands zu beurteilen. Für die Testdurchführung wurden Spektrographen, Kamerasund bestimmte Auswertungstools für optische Anwendungen benutzt. Das Verhaltendes Vulcain 2.1 Abgasstrahls abhängig von verschiedenen ROF und Druckstufen ist in denErgebnissen beschrieben. Für das LUMEN Triebwerk konnten erste Zündplasmatemperaturenbestimmt werden und geben einen Rückschluss auf die Qualität des LTE.

Microelectronics has shaped the world beyond what was thought possible at the time of its advent. One area of current research in this field is on the solid-state Si:P-based quantum computer (QC). In this machine, each qubit requires an individually addressed fast control-pulse for non-adiabatic drive and measure operations. Additionally, it is increasingly becoming important to be able to interface nanoelectronics with complementary metal-oxide-semiconductor (CMOS) technology. In this work, I have designed and demonstrated full-custom mixed-mode and full-digital fast control-pulse generators fabricated in a silicon-on-sapphire (SOS) CMOS commercial foundry process ?? a radio-frequency (RF) CMOS technology. These circuits are, fundamentally, fast monostable multivibrators. Initially, after the design specifications were decided upon, I characterized NFET and PFET devices and a n+-diffusion resistor from 500 nm and 250 nm commercial SOS-CMOS processes. Measuring their conductance curves at 300 300 K, 4.2 2 K, and sub-K (30 30 mK base to 1000 1000 mK) showed that they function with desirable behaviour although exhibiting some deviations from their 300 300 K characteristics. The mixed-mode first generation control-pulse generator was demonstrated showing that it produced dwell-time adjustable pulses with 100 100 ps rise-times at 300 K, 4.2 2 K, and sub-K with a power dissipation of 12 12 uW at 100 100 MHz. The full-digital second generation control-pulse generator was demonstrated showing accurately adjustable dwell-times settable via a control-word streamed synchronously to a shift-register. The design was based on a ripple-counter with provisions for internal or external clocking. This research has demonstrated that SOS-CMOS technology is highly feasible for the fabrication of control microelectronics for a Si:P-based QC. I have demonstrated full-custom SOS-CMOS mixed-mode and full-digital control circuits at 300 300 K, 4.2 2 K, and sub-K which suitable for qubit control.

<p>Detta är ett examensarbete som genomförts hos Göteborg Energi AB och syftar till att utreda omkryogen uppgradering av biogas med fördel kan ske genom att producera nödvändig kyla medvärmedriven absorptionskylmaskin. Göteborg Energi är en av tre parter som tillsammans ska bygga enbiogasanläggning i Lidköping som ska vara i drift 2010. Anläggningen ska producera 30 GWhflytande biogas per år.</p><p>Arbetet utreder om det är fördelaktigt ur ekonomiskt, energimässigt och miljömässigt perspektiv attuppgradera biogas med kryogen teknik med värmeproducerad kyla. En jämförelse görs först medkryogen teknik där kylan är producerad med el och sen med andra uppgraderingstekniker. Som stödhar två olika processimuleringsprogram används, Hysys och DESIGN II.</p><p>Resultatet visar att energianvändningen ökar då värmedriven kyla används i jämförelse med kylaproducerad med el. 0,47 kW/Nm3 rågas för kryo med absorptionskyla och 0,29 kW/Nm3 rågas medel. Om det finns avsättning för spillvärmen kan energianvändningen i uppgraderingen minska till 0,29kW/Nm3 rågas och 0,15 kW/Nm3 rågas för systemet med värmedriven respektive eldriven kyla. Ijämförelse med andra uppgraderingstekniker ligger 0,47 kW/Nm3 bland de teknikerna med högstenergianvändning medans 0,29 kW/Nm3 placerar sig bland de teknikerna med lägstenergianvändning.</p><p>Resultat visar att klimatpåverkan från uppgraderingen, som kommer av metanslip och elanvändningen,minskar marginellt om kylan produceras med värme istället för el. Resultatet varierar mycket beroendepå hur koldioxidutsläppen från marginalelen beräknas. I jämförelse med andra uppgraderingsteknikerligger kryo lägre än de flesta andra. Undantaget är COOAB-tekniken som är överlägset bäst tack varalågt metanslip och liten elanvändning.</p><p>Ekonomisk jämförelse med andra uppgraderingstekniker visar att kostnaden för energianvändningenligger i samma nivå som övriga uppgraderingstekniker i jämförelsen, ca 0,03 kr/kWh uppgraderad gas.Om det finns avsättning för spillvärmen sjunker kostnaden till 0,024 och 0,02 kr/kWh uppgraderad gasför kryoteknik med kyla ifrån värme respektive el.</p><p>Min slutsats är att utnyttjande av spillvärmen är av stor vikt för att få god ekonomi och lågenergianvändning med kryogen uppgradering. En marginellt förbättrad miljöprestanda kan erhållas omnödvändig kyla produceras med värme istället för el då kryogen uppgradering används. Annars är detalltid mer fördelaktigt att använda el för att producera nödvändig kyla.</p> / <p>This is a master thesis that has been carried out at Göteborg Energi AB. It refers to investigate ifcryogenic upgrading of biogas with advantage can be done by producing necessary cold with a heatdriven absorption cooling machine. Göteborg Energi is one of three actors that together will build abiogas plant in Lidköping that will be up and running in 2010. The plant will produce 30 GWhliquefied biogas annually.</p><p>This thesis investigastes whether it is advantageous, to upgrade biogas with heat driven cooling, in aperspective of economy, energy use and environment. It compares cryogenic upgrading with coldproduced by electricity, but also by other techniques. Two different process simulation softwares havebeen used as support to this thesis; Hysys and DESIGN II.</p><p>The result shows that energy usage increases when the necessary cold is produced with heat instead ofelectricity; 0,47 kW/Nm3 rawgas for cryo upgrade with absorptions cooling and 0,29 kW/Nm3 rawgaswith cold produced by electricity. If it’s possible to use the waste heat to warm the digester, the energyconsumption for the upgrading can be reduced to 0,29 kW/Nm3 for the system with heat-driven cold,and 0,15 kW/Nm3 rawgas for cold produced by electricity. In comparison with other techniques forupgrading, 0,47 kW/Nm3 rawgas is a high value while 0,29 kW/Nm3 rawgas is among the lowestvalues for energy use.</p><p>The impact on the climate emerges from the use of electricity and when methane slips out from theupgrading plant. The result shows that the impact on the climate is slightly decreased for cryogenicupgrading when the cold is produced with a heat driven absorption machine instead of electricity. Theresult varies a lot due to how one calculate the emission of carbon dioxide from the electricity on themargin. In comparison with other upgrading techniques, the climate impact from cryogenic upgradingis less, other than the COOAB-technique that is superior because of its low methane slip and lowdemand of electricity.</p><p>An economical comparison shows that the cost for energy usage is about the same for cryogenic as forother techniques; approximately 0,03 SEK/kWh upgraded gas. If one can utilize the waste heat, thecost would be decreased to 0,024 and 0,02 SEK/kWh upgraded gas for the system with cryogenicupgrading with cooling from absorption machine respectively cooling produced with electricity.</p><p>My conclusion is that the utilization of the waste heat is essential if one wishes to get good economyand low energy use for the upgrading of biogas with cryogenic methods. A slightly increasedenvironmental improvement can be received if one change the cold production from electricity to heat,otherwise it is always more advantageous to use electricity for cryogenic methods.</p>

Transmission Electron Microscopy (TEM) on light element materials and soft matters is problematic due to electron irradiation damage and low contrast. In this doctoral thesis techniques were developed to address some of those issues and successfully characterize these materials at high resolution. These techniques were demonstrated on graphene flakes, DNA/magnetic beads and a number of water containing biomaterials. The details of these studies are given below. A TEM based method was presented for thickness characterization of graphene flakes. For the thickness characterization, the dynamical theory of electron diffraction is used to obtain an analytical expression for the intensity of the transmitted electron beam as a function of thickness. From JEMS simulations (experiments) the absorption constant λ in a low symmetry orientation was found to be ~ 208 nm (225 ± 9 nm). When compared to standard techniques for thickness determination of graphene/graphite, the method has the advantage of being relatively simple, fast and requiring only the acquisition of bright-field (BF) images. Using the proposed method, it is possible to measure the thickness change due to one monolayer of graphene if the flake has uniform thickness over a larger area. A real-space TEM study on magnetic bead-DNA coil interaction was conducted and a statistical analysis of the number of beads attached to the DNA-coils was performed. The average number of beads per DNA coil was calculated around 6 and slightly above 2 for samples with 40 nm and 130 nm beads, respectively. These results are in good agreement with magnetic measurements. In addition, the TEM analysis supported an earlier hypothesis that 40 nm beads are preferably attached interior of the DNA-coils while 130 nm beads closer to the exterior of the coils. A focused ion-beam in-situ lift-out technique for hydrated biological specimens was developed for cryo-TEM. The technique was demonstrated on frozen Aspergillus niger spores which were frozen with liquid nitrogen to preserve their cellular structures. A thin lamella was prepared, lifted out and welded to a TEM grid. Once the lamella was thinned to electron transparency, the grid was cryogenically transferred to the TEM using a cryo-transfer bath. The structure of the cells was revealed by BF imaging. Also, a series of energy filtered images was acquired and C, N and Mn elemental maps were produced. Furthermore, 3 Å lattice fringes of the underlying Al support were successfully resolved by high resolution imaging, confirming that the technique has the potential to extract structural information down to the atomic scale. The experimental protocol is ready now to be employed on a large variety of samples e.g. soft/hard matter interfaces.

Detta är ett examensarbete som genomförts hos Göteborg Energi AB och syftar till att utreda omkryogen uppgradering av biogas med fördel kan ske genom att producera nödvändig kyla medvärmedriven absorptionskylmaskin. Göteborg Energi är en av tre parter som tillsammans ska bygga enbiogasanläggning i Lidköping som ska vara i drift 2010. Anläggningen ska producera 30 GWhflytande biogas per år. Arbetet utreder om det är fördelaktigt ur ekonomiskt, energimässigt och miljömässigt perspektiv attuppgradera biogas med kryogen teknik med värmeproducerad kyla. En jämförelse görs först medkryogen teknik där kylan är producerad med el och sen med andra uppgraderingstekniker. Som stödhar två olika processimuleringsprogram används, Hysys och DESIGN II. Resultatet visar att energianvändningen ökar då värmedriven kyla används i jämförelse med kylaproducerad med el. 0,47 kW/Nm3 rågas för kryo med absorptionskyla och 0,29 kW/Nm3 rågas medel. Om det finns avsättning för spillvärmen kan energianvändningen i uppgraderingen minska till 0,29kW/Nm3 rågas och 0,15 kW/Nm3 rågas för systemet med värmedriven respektive eldriven kyla. Ijämförelse med andra uppgraderingstekniker ligger 0,47 kW/Nm3 bland de teknikerna med högstenergianvändning medans 0,29 kW/Nm3 placerar sig bland de teknikerna med lägstenergianvändning. Resultat visar att klimatpåverkan från uppgraderingen, som kommer av metanslip och elanvändningen,minskar marginellt om kylan produceras med värme istället för el. Resultatet varierar mycket beroendepå hur koldioxidutsläppen från marginalelen beräknas. I jämförelse med andra uppgraderingsteknikerligger kryo lägre än de flesta andra. Undantaget är COOAB-tekniken som är överlägset bäst tack varalågt metanslip och liten elanvändning. Ekonomisk jämförelse med andra uppgraderingstekniker visar att kostnaden för energianvändningenligger i samma nivå som övriga uppgraderingstekniker i jämförelsen, ca 0,03 kr/kWh uppgraderad gas.Om det finns avsättning för spillvärmen sjunker kostnaden till 0,024 och 0,02 kr/kWh uppgraderad gasför kryoteknik med kyla ifrån värme respektive el. Min slutsats är att utnyttjande av spillvärmen är av stor vikt för att få god ekonomi och lågenergianvändning med kryogen uppgradering. En marginellt förbättrad miljöprestanda kan erhållas omnödvändig kyla produceras med värme istället för el då kryogen uppgradering används. Annars är detalltid mer fördelaktigt att använda el för att producera nödvändig kyla. / This is a master thesis that has been carried out at Göteborg Energi AB. It refers to investigate ifcryogenic upgrading of biogas with advantage can be done by producing necessary cold with a heatdriven absorption cooling machine. Göteborg Energi is one of three actors that together will build abiogas plant in Lidköping that will be up and running in 2010. The plant will produce 30 GWhliquefied biogas annually. This thesis investigastes whether it is advantageous, to upgrade biogas with heat driven cooling, in aperspective of economy, energy use and environment. It compares cryogenic upgrading with coldproduced by electricity, but also by other techniques. Two different process simulation softwares havebeen used as support to this thesis; Hysys and DESIGN II. The result shows that energy usage increases when the necessary cold is produced with heat instead ofelectricity; 0,47 kW/Nm3 rawgas for cryo upgrade with absorptions cooling and 0,29 kW/Nm3 rawgaswith cold produced by electricity. If it’s possible to use the waste heat to warm the digester, the energyconsumption for the upgrading can be reduced to 0,29 kW/Nm3 for the system with heat-driven cold,and 0,15 kW/Nm3 rawgas for cold produced by electricity. In comparison with other techniques forupgrading, 0,47 kW/Nm3 rawgas is a high value while 0,29 kW/Nm3 rawgas is among the lowestvalues for energy use. The impact on the climate emerges from the use of electricity and when methane slips out from theupgrading plant. The result shows that the impact on the climate is slightly decreased for cryogenicupgrading when the cold is produced with a heat driven absorption machine instead of electricity. Theresult varies a lot due to how one calculate the emission of carbon dioxide from the electricity on themargin. In comparison with other upgrading techniques, the climate impact from cryogenic upgradingis less, other than the COOAB-technique that is superior because of its low methane slip and lowdemand of electricity. An economical comparison shows that the cost for energy usage is about the same for cryogenic as forother techniques; approximately 0,03 SEK/kWh upgraded gas. If one can utilize the waste heat, thecost would be decreased to 0,024 and 0,02 SEK/kWh upgraded gas for the system with cryogenicupgrading with cooling from absorption machine respectively cooling produced with electricity. My conclusion is that the utilization of the waste heat is essential if one wishes to get good economyand low energy use for the upgrading of biogas with cryogenic methods. A slightly increasedenvironmental improvement can be received if one change the cold production from electricity to heat,otherwise it is always more advantageous to use electricity for cryogenic methods.

Microelectronics has shaped the world beyond what was thought possible at the time of its advent. One area of current research in this field is on the solid-state Si:P-based quantum computer (QC). In this machine, each qubit requires an individually addressed fast control-pulse for non-adiabatic drive and measure operations. Additionally, it is increasingly becoming important to be able to interface nanoelectronics with complementary metal-oxide-semiconductor (CMOS) technology. In this work, I have designed and demonstrated full-custom mixed-mode and full-digital fast control-pulse generators fabricated in a silicon-on-sapphire (SOS) CMOS commercial foundry process ?? a radio-frequency (RF) CMOS technology. These circuits are, fundamentally, fast monostable multivibrators. Initially, after the design specifications were decided upon, I characterized NFET and PFET devices and a n+-diffusion resistor from 500 nm and 250 nm commercial SOS-CMOS processes. Measuring their conductance curves at 300 300 K, 4.2 2 K, and sub-K (30 30 mK base to 1000 1000 mK) showed that they function with desirable behaviour although exhibiting some deviations from their 300 300 K characteristics. The mixed-mode first generation control-pulse generator was demonstrated showing that it produced dwell-time adjustable pulses with 100 100 ps rise-times at 300 K, 4.2 2 K, and sub-K with a power dissipation of 12 12 uW at 100 100 MHz. The full-digital second generation control-pulse generator was demonstrated showing accurately adjustable dwell-times settable via a control-word streamed synchronously to a shift-register. The design was based on a ripple-counter with provisions for internal or external clocking. This research has demonstrated that SOS-CMOS technology is highly feasible for the fabrication of control microelectronics for a Si:P-based QC. I have demonstrated full-custom SOS-CMOS mixed-mode and full-digital control circuits at 300 300 K, 4.2 2 K, and sub-K which suitable for qubit control.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-10-17T19:51:05Z No. of bitstreams: 1 ALESSANDRA ALMEIDA CASTRO - TESE PPGEP 2004..pdf: 50999854 bytes, checksum: 5c3c28a3bdfe146c8c95c174dbbd858e (MD5) / Made available in DSpace on 2018-10-17T19:51:05Z (GMT). No. of bitstreams: 1 ALESSANDRA ALMEIDA CASTRO - TESE PPGEP 2004..pdf: 50999854 bytes, checksum: 5c3c28a3bdfe146c8c95c174dbbd858e (MD5) Previous issue date: 2004-08-20 / Capes / O objetivo desta pesquisa foi estudar o efeito das técnicas de: a) congelamento nas temperaturas de -20 °C, -196 °C e -170 °C; b) armazenamento as temperaturas de (-20 °C, -30 °C e -170 °C, e c) do método de descongelamento (temperatura ambiente: aproximadamente 25 °C e em banho termostatizado: 35 °C) sobre duas amostras de camarão: 1) com exoesqueleto e cabeça e 2) sem exoesqueleto e sem cabeça, por um período de 12 meses de armazenamento. Foram determinados os seguintes parâmetros: a) características físicas (massa, comprimento, espessura e volume); b) cinética de congelamento as temperaturas de -20 °C, -170 °C e -196 °C; c) propriedades termofisicas (densidade, calor específico, difusividade térmica e condutividade térmica); d) características físico-químicas (conteúdo de água, cinzas, proteínas, pH, carboidratos, gorduras, calorias, exsudado e um atributo de textura: dureza); e) caracterização microbiológica (salmonela, coliformes fecais, vibrio parahaemolyticus) e f) avaliação sensorial (sabor, odor, textura e aparência), visando verificar a eficácia das técnicas de congelamento e descongelamento na qualidade do camarão armazenado. Na análise da cinética, as curvas de congelamento obtidas à temperatura de -20 °C para o camarão com exoesqueleto e cabeça e para o filé foram observadas claramente as três fases, ou seja, resfriamento, cristalização e pós-congelamento. Este fato também ocorreu para o camarão com cabeça congelado a -170 °C, já para o filé congelado a -170 °C não se distinguiu com clareza a fase I da Fase II, ou seja, a fase de resfriamento e a fase de cristalização, fato este atribuído a maior velocidade de congelamento. Nas curvas de congelamento do camarão com cabeça e filé quando estes foram submetidos ao congelamento por imersão em N2 líquido (-196 °C) também não se observou uma distinção entre as fases de resfriamento e cristalização. Com relação às propriedades termofisicas, a densidade do camarão "fresco" (25 °C) com exoesqueleto e cabeça foi de l,066g/cm3 e do filé foi de l,02g/cm3. Os valores médios do calor específico do camarão com exoesqueleto e do filé "fresco" foram de 0,84 e 0,86 kcal/kg °C, respectivamente e para o camarão com exoesqueleto e filé à temperatura de -170 °C foram de 0,28 kcal/kg °C, 0,31 kcal/kg °C e a -196 °C foram de 0,25 kcal/kg °C e 0,28 kcal/kg °C, respectivamente. A difusividade efetiva média do camarão com exoesqueleto às temperaturas de -20 °C, -170 °C e -196 °C, foi de 9,13 x 10 3 mm2/s; 29 x 10 3 mm2/s; 571,8 x 10 3 mm2/s e para o filé nas mesmas temperaturas foi 9,9 x 10 3 mm2/s; 28,1 x IO"3 mm2/s; 384,3 x IO"3 mm2/s. A condutividade térmica média para o camarão com exoesqueleto às temperaturas de -170°C e -196 °C foi de 0,032 W/m °C e 0,499 W/m °C e para o filé nas mesmas temperaturas foi de 0,029 W/m °C e 0,371 W/m °C, respectivamente. Na caracterização físico-química, tanto nos camarões com cabeça quanto nos filés, congelados e armazenados em vapor de N2 (-170 °C) mantiveram-se inalterados o conteúdo de água, cinzas, proteínas, pH, gorduras e exsudado, durante todo o período de armazenagem. Os resultados das análises microbiológicas dos camarões frescos, depois de congelados e durante os 12 meses de armazenamento, apresentaram ausência de salmonela, de coliformes fecais e vibrio parahaemolyticus. Na avaliação sensorial quanto aos atributos sabor, odor, textura e aparência, os degustadores demonstraram preferência pelas amostras congeladas e armazenadas em vapor de N2, as amostras que tiveram menores índices de aceitabilidade foram às congeladas e armazenadas a -20 °C. Concluiu-se ainda que tanto no sabor, odor e textura, em todos os tratamentos, as médias das notas dos camarões descongelados em banho termostatizado à temperatura de 35 °C foram menores que as descongeladas a temperatura ambiente, todavia, na avaliação da aparência do camarão com exoesqueleto e cabeça, quando descongeladas em banho termostatizado a 35 °C, apresentaram notas mais elevadas que as descongeladas à temperatura ambiente, tal fato é atribuído a astaxantina existente em crustáceos, que quando aquecida dá a cor alaranjada ao camarão. / The objective of this research was to study the effect of techniques of: 1) freezing in temperatures of-20 °C, -196 °C and -170 °C; 2) storage in temperatures of (-20 °C, -30 °C and -170 °C, and 3) of unfreezing method ( environmental temperature: approximately 25 °C and in thermostatized bath: 35 °C) on two samples of shrimp: 1) with exoskeleton and head and 2) without exoskeleton and head, for a period of 12 months of storage. The following parameters had been determined: 1) physical characteristics (mass, length, thickness and volume); 2) kinetic freezing of temperatures at -20 °C, -170 °C and -196 °C; 3) thermophysical properties (density, specific heat, thermal diffusivity and thermal conductivity); 4) physicochemical characteristic (water content, ashes, proteins, pH, carbohydrates, fats, calories, exuded and an texture attribution: hardness); 5) microbiological characterization (salmonella, fecale coliform, vibrio parahaemolyticus) and 6) sensorial evaluation (flavor, scent, texture and appearance), aiming to verify the effectiveness of freezing and unfreezing techniques in the quality of the stored shrimp. During kinetic analysis, the curves of freezing obtained at the temperature of -20 °C for the shrimp with the head and exoskeleton for the filet, the three phases, or better saying, cooling, crystallization and after-freezing were clearly observed. This fact also occurred for the shrimp with frozen head at -170 °C, on the other hand for the filet at -170 °C, it was not easy to distinguish with clarity phase I from Phase II, in other words, the phases of cooling and crystallization, due to the speed of freezing. At the shrimps with head freezing curve, it was observed that when these were submitted to freezing by immersion in liquid N2 (-196 °C) there was not any distinction between the phases of cooling and crystallization. In relation to the thermophysical properties, the density of fresh shrimp (25 °C) with exoskeleton and head were of l,066g/cm3 and of that of filet was l,02g/cm3. The average values of the specific heat of the shrimp with exoskeleton and fresh filet is of 0,84 and 0,86 kcal/kg °C, respectively and for shrimp with exoskeleton and filet at temperature of -170 °C were of 0,28 kcal/kb °C, 0.31 kcal/kg °C and 196°C were of 0,25 kcal/kg °C and 0,28 kcal/kg °C, respectively. The medium diffusivity effectiveness of the shrimp with exoskeleton at the temperatures of -20 °C, -170 °C and -196 °C, was of 9,13 x 10"3 mm2/s; 29 x 10"3 mm2/s; 571,8 x 10"3 mm2/s and for the filet at the same temperature was 9,9 x 10"3 mm2/s temperatures was; 28.1 x 10"3 mm2/s; 384,3 x 10"3 mm2/s. The average thermal conductivity for shrimp with exoskeleton at -170 °C and -196 °C was of 0,032 W/m °C and 0,499 W/m °C and for filet at the temperature was of 0,029 W/m °C and 0.371 W/m °C, respectively. For physicist-chemistry characterization, both in shrimps with head as well as that of filet, frozen and stored in N2 vapor (-170 °C) the water content, proteins, pH, fats and exuded remained unchanged during all the period of storage. The results of the microbiological analyses of the fresh shrimps, after been frozen and during 12 months of storage, presented absence of salmonella, fecal coliform and vibrio parahaemolyticus. In the sensorial evaluation as much as flavor, scent, texture and appearance are concerned, the testators demonstrated preference for samples frozen and stored in vapor of N2, the samples with the least acceptability indices were those frozen and stored at -20 °C. It was concluded that in the flavor, scent and texture, in all the treatments, the average notes of defrosted shrimps in thermostatized bath of 35 °C temperature were less than those defrosted at environmental temperature, however, in the evaluation of the appearance of the shrimp with exoskeleton and head, when defrosted at thermostatized bath of 35 °C, presented higher notes than those defrosted at environmental temperature, such facts are attributed to astaxantine existing in crustaceans, which when heated, gives the shrimp that gives the orange color to the shrimp,

En microélectronique, les techniques actuelles de fabrication des supercondensateurs requièrent le développement de motifs nanostructurés de surface spécifique élevée. Nous nous intéressons à une alternative émergeante aux techniques classiques ‘top-down’ de fabrication des masques de gravure : les mélanges d’homopolymères. En effet, deux polymères avec des chimies différentes sous forme de films minces peuvent conduire à une séparation de phase avec des domaines cylindriques de taille sub-micrométrique. Une gravure cryogénique au travers de ces masques produit une nanostructuration avec une importante surface spécifique. Les travaux de cette thèse ont porté sur la réalisation des films minces et sur la compréhension des mécanismes d’obtention de la morphologie finale. Une étude a été menée sur les solvants de dépôt et d’exposition pour déterminer leur influence sur les morphologies. Les paramètres influençant la taille des motifs sont ensuite étudiés. Des domaines de moins de 100 nm ont été obtenus. Finalement, l’étude d’une méthode alternative de dépôt par dip-coating a permis l’obtention d’une grande variété de morphologies en une seule étape et pour une même solution. Ces travaux se sont ensuite orientés sur la réalisation des motifs en gravant par plasma le silicium au travers de ces masques. Deux procédés ont été retenus, adaptés et optimisés afin de réaliser des gravures profondes sans défaut. Le procédé STiGer aniso permet de les obtenir et ce, avec la meilleure répétabilité. Un autre axe, portant sur l’optimisation de la sélectivité en modifiant la nature du masque, a été développé. Une sélectivité de 70 : 1 est obtenue pour un masque de poly(styrène) marqué au Ru. / In microelectronics, current techniques for supercapacitors manufacturing requires the development of nanostructured patterns with high specific surface. We are interested in an emerging alternative approach to conventional 'top-down' fabrication techniques based on blends of homopolymers. Indeed, two polymers with different chemistries in thin films can lead to phase separation with cylindrical domains of sub-micrometer size. A cryogenic plasma through these masks can produce nanostructuration with a high specific surface. The work of this thesis focused on the realization of thin films and on the understanding of the mechanisms to obtain the final morphology. A study on solvent deposition and exposure was led to determine their influence on the morphologies. The parameters influencing the size of the domains are then studied. Domains of less than 100 nm were obtained. Finally, the study of an alternative method of deposition by dip-coating enabled to obtain a variety of morphologies in one step and for the same solution. This work was then directed towards the realization of structured surfaces by plasma etching of the silicon through this masks. Two methods were used, adapted and optimized to achieve deep etched without default. The process StiGer aniso allows to obtain this and with better repeatability. Another axis is developed. It is focused on the optimization of the selectivity by modifying the nature of the mask. We succeed in obtaining a selectivity of 70: 1 with a mask of poly(styrene) stained by Ru.

Aviation industry is continuously growing especially for very long distance flights due to the globalisation of local economies around the world and the explosive economic growth in Asia. Reducing the time of intercontinental flights from 16-20 hours to 4 hours or less would therefore make the, already booming, ultra-long distance aviation sector even more attractive. To accomplish this drastic travel time reduction for civil transport, hypersonic cruise aircraft are considered as a potential cost-effective solution. Such vehicles should also be fuelled by liquid hydrogen, which is identified as the only viable propellant to achieve antipodal hypersonic flight with low environmental impact. Despite considerable research on hypersonic aircraft and hydrogen fuel, several major challenges should still be addressed before such airliner becomes reality. The current thesis is therefore motivated by the potential benefit of hydrogen-fuelled hypersonic cruise vehicles associated with their limited state-of-the-art.Hypersonic cruise aircraft require innovative structural configurations and thermal management solutions due to the extremely harsh flight environment, while the uncommon physical properties of liquid hydrogen, combined with high and long-term heat fluxes, introduce complex design and technological storage issues. Achieving hypersonic cruise vehicles is also complicated by the multidisciplinary nature of their design. In the scope of the present research, appropriate methodologies are developed to assess, design and optimize the thermo-structural model and the cryogenic fuel tanks of long-range hydrogen-fuelled hypersonic civil aircraft. Two notional vehicles, cruising at Mach 5 and Mach 8, are then investigated with the implemented methodologies. The design analysis of light yet highly insulated liquid hydrogen tanks for hypersonic cruise vehicles indicates an optimal gravimetric efficiency of 70-75% depending on insulation system, tank wall material, tank diameter, and flight profile. A combination of foam and load-bearing aerogel blanket leads to the lightest cryogenic tank for both the Mach 5 and the Mach 8 aircraft. If the aerogel blanket cannot be strengthened sufficiently so that it can bear the full load, then a combination of foam and fibrous insulation materials gives the best solution for both vehicles. The aero-thermal and structural design analysis of the Mach 5 cruiser shows that the lightest hot-structure is a titanium alloy construction made of honeycomb sandwich panels. This concept leads to a wing-body weight of 143.9 t, of which 36% accounts for the wing, 32% for the fuselage, and 32% for the cryogenic tanks. As expected, hypersonic thermal loads lead to important weight penalties (of more than 35%). The design of the insulated cold structure, however, demonstrates that the long-term high-speed flight of the airliner requires a substantial thermal protection system, such that the best configuration (obtained by load-bearing aerogel blanket) leads to a titanium cold design of only 4% lighter than the hot structure. Using aluminium 7075 rather than titanium offers a further weight saving of about 2%, resulting in a 135.4 t wing-body weight (with a contribution of 23%, 25%, 18% and 34% from the TPS, the wing, the fuselage, and the cryogenic tanks respectively). Given the design hypotheses, the difference in weight is not significant enough to make a decisive choice between hot and cold concepts. This requires the current methodologies to be further elaborated by relaxing the simplifications. Investigation of the thermal protection must be extended from one single point to different regions of the vehicle, and the TPS thickness and weight should be considered in the structural sizing of the cold design. More generally, the design process should be matured by including additional (static, dynamic and transient) loads, special structural concepts, multi-material configurations and other parameters such as cost and safety aspects. / Doctorat en Sciences de l'ingénieur et technologie / This thesis was conducted in co-tutelle between University of Sydney and Université Libre de Bruxelles.Professor Dries Verstraete was my supervisor at the University of Sydney (so as a member of SydneyUni), but is automatically registered here as a member of ULB because he worked at ULB almost ten years ago.Ben Thornber is also a member of the University of Sydney but the application does not save it for an unknown reason. / info:eu-repo/semantics/nonPublished