In this work is described design of measuring and evaluation system for temperature rise tests in cooperation with ABB company. As temperature sensors are used thermocouples type L and measuring hardware consists of chassis cRIO 9073 and measuring card NI 9213. In LabVIEW 2011 is created software for cRIO and as well for control PC and structure of both programs is described in detail. Thesis includes also practical estimation of metrological parameters of created system.

Water temperature in rivers and streams is an important factor for aquatic ecosystem health. Measurement of stream temperature has traditionally been accomplished by point temperature measurements, continuous point temperature loggers, and more recently, airborne remote sensing techniques such as Forward-Looking Infrared Radar (FLIR) or Thermal Infrared Radiometry. While each of these measurement techniques has certain advantages, none allows for the combined spatial and temporal information provided by Distributed Temperature Sensing (DTS). DTS employs fiber optic signals to measure temperature and is a relatively new temperature measurement technology for hydrologic sensing applications. Nine DTS stream temperature datasets were collected in the Middle Fork John Day River (MFJDR) as part of a basin-wide stream monitoring effort. The datasets encompassed five 1-3 kilometer long reaches, some monitored over three summers (2009-2011). In contrast to existing stream temperature measurement technologies, DTS can provide stream temperature data in both the spatial and temporal domains. Techniques and challenges of interpreting DTS stream temperature data were documented, and three applications of the technology to stream temperature monitoring were explored. Cold water patches, potentially used by fish as thermal refugia during stream temperature maximums, were located using DTS. No identified cold patch exceeded 2.31°C cooler than ambient stream temperature. Tributary inflows provided some of the most temperature-differentiated cold patches. These findings provide a reference for the degree of thermal heterogeneity in the MFJDR system and beg the question of whether fish respond to small (<3°C) spatial temperature variations. Theoretical predictions of stream mixing potential (Richardson number and cavity flow mixing predictions) suggested that increasing stream thermal heterogeneity would require channel modification to decrease stream flow velocity in select areas. The combined spatial and temporal coverage of a DTS stream temperature dataset on the Oxbow Conservation Area allowed diagnosis of a 2°C longitudinal stream temperature decrease observed in multiple Thermal Infrared Radiometry (TIR) and Forward-Looking Infrared Radiometry (FLIR) datasets collected on that reach. Advection velocity and channel depth, rather than groundwater or tributary inflows, were the main cause of the decrease, and the magnitude of the decrease peaked in the early afternoon, disappearing completely by evening. This finding suggests caution for interpretation of FLIR and TIR stream temperature datasets, which represent "snapshot" temperature measurements. For these datasets, knowledge of flow conditions (velocity and depth) may help avoid misinterpretation of temporally-transient temperature anomalies. Diurnal slope periodicity was observed in linear-like spatial trends in four DTS datasets, and an analysis was made to examine this subtle spatially and temporally varying phenomenon. The phase of the diurnal slope variation differed between river reaches, suggesting that propagation of larger-scale thermal waves might be one driving mechanism. Temporally-constant offsets between slope magnitudes within reaches suggested some intra-reach differences in heat fluxes. / Graduation date: 2012

The ability to resolve reactions within a monolith spatially and temporally is key in developing reliable kinetic models, as well as in validating proposed reaction mechanisms. In this work, two techniques, IR-thermography and spatially-resolved capillary inlet mass spectrometry (SpaciMS), were used to measure temperature and gas-phase concentrations. Specifically, they were applied to monitor the axial distribution of temperature and concentration profiles during propylene oxidation over a Pt/Al2O3 monolith-supported catalyst. Also, the effect of thermally aging the catalyst on the temperature and concentration patterns observed was investigated. During temperature programmed oxidation experiments, the data show that conversion of propylene began at the outlet, and a reaction front generated at the rear of the monolith traveled upstream, as a moving reaction zone, thereby creating a temperature wave pattern since the reaction is exothermic. The conversion was always complete downstream of this reaction zone at any point along the catalyst. When the reactor was cooled, the conversion of propylene started to drop, accompanied by a similar temperature wave pattern that traveled in the opposite direction (from upstream to downstream) and was attributed to a phenomenon known as wrong-way behavior. Finally, thermally aging the catalyst led to a slower and more localized moving hot zone.

The ability to resolve reactions within a monolith spatially and temporally is key in developing reliable kinetic models, as well as in validating proposed reaction mechanisms. In this work, two techniques, IR-thermography and spatially-resolved capillary inlet mass spectrometry (SpaciMS), were used to measure temperature and gas-phase concentrations. Specifically, they were applied to monitor the axial distribution of temperature and concentration profiles during propylene oxidation over a Pt/Al2O3 monolith-supported catalyst. Also, the effect of thermally aging the catalyst on the temperature and concentration patterns observed was investigated. During temperature programmed oxidation experiments, the data show that conversion of propylene began at the outlet, and a reaction front generated at the rear of the monolith traveled upstream, as a moving reaction zone, thereby creating a temperature wave pattern since the reaction is exothermic. The conversion was always complete downstream of this reaction zone at any point along the catalyst. When the reactor was cooled, the conversion of propylene started to drop, accompanied by a similar temperature wave pattern that traveled in the opposite direction (from upstream to downstream) and was attributed to a phenomenon known as wrong-way behavior. Finally, thermally aging the catalyst led to a slower and more localized moving hot zone.

Shape Memory Alloy is an amazing material, which can “remember” and return to its original shape when heated due to its temperature dependent phase transformation. Shape Memory Alloy wire has significant potential for application in the automobile industry due to its high ratio of energy / weight and silent actuation. However, a dependable method to measure the operating temperature of SMA wire and a reliable heat transfer model to characterize the dynamics of the SMA wire limit its widespread use in the automobile industry. This thesis presents a detailed description of the work performed to develop a reliable method for determining surface temperature of current carrying SMA wires and the development of a heat transfer correlation for natural convection cooling of heated SMA wires. The major findings of the research are as follows: When a spot welded thermocouple measures the temperature of a current carrying SMA wire, there is a “spurious voltage” ΔV added to the thermo electro-motive force (EMF) of the thermocouple as a result of a voltage drop across the two points of contact that the thermocouple wires make with the SMA wire. This leads to an erroneous temperature reading that can be higher or lower than the actual temperature depending on the direction of current flow. When the carrying current is reversed in direction, the “spurious voltage” becomes –ΔV allowing a correct temperature reading to be obtained by averaging the readings based on opposed current flow. A two-step spot welding procedure for attaching thermocouples to SMA wire can eliminate the influence of the “spurious voltage” in the temperature reading. By spot welding the thermocouple wires onto the SMA wire one by one, the thermocouple lead offset is eliminated and the thermocouple provides an accurate point source reading. Infrared thermal imaging can be a good supplement in the experiment to monitor errors in temperature readings from thermocouples. Due to the curvature of the SMA wire, the temperatures of the locations on the SMA wire that are the closest to the infrared camera represent the temperature of the SMA wire. So a line analysis across the SMA wire on the software “ThermaCAM” is required to determine the temperature of the SMA wire by infrared thermal imaging and the highest temperature on the line is the temperature of the SMA wire. A new natural convective heat transfer correlation comprising the inclination angle φ is developed based on experimental results, which can be used to predict the temperature of a SMA wire given its diameter and inclination angle. The comparisons show that the new correlation agrees with existing correlations in a vertical orientation and for small Rayleigh numbers (0.001 < RaD < 0.05) in the horizontal orientation. The correlation developed in this work for horizontal orientation tends to overestimate values of Nusselt numbers as predicted in other correlations when the Rayleigh number is high (0.05 < RaD < 0.6). It is speculated that this overestimation can be attributed to a temperature distortion associated with thermocouple measurement at or near ambient pressure conditions.

A spectroscopic diagnostic tool has been developed to determine the electron temperature and the neutral density in helium, hydrogen and argon plasmas from absolutely calibrated spectroscopic measurements. For each gas, a method of analysis which uses models specific to each species present in the plasma (neutral atom or singly ionized atom) has been defined. The experimental electron density is used as an input parameter to the models, and the absolutely calibrated spectroscopic data are processed beforehand to obtain the populations of the upper excited levels corresponding to the observed spectral lines. For helium plasmas, the electron temperature is inferred from the experimental helium ion excited level p = 4 population using a corona model, and then the neutral density is determined from the experimental helium neutral excited level populations using a collisional-radiative model for helium neutrals. For hydrogen plasmas, combinations of the electron temperature and the neutral density are determined from the experimental hydrogen neutral excited level populations using a collisional-radiative model specific to hydrogen atoms. For argon plasmas, the electron temperature is inferred from the experimental argon ion excited level populations using a collisional-radiative model for argon ions, and then the neutral density is determined from the experimental argon neutral excited level populations using a collisional-radiative model for argon neutrals. This diagnostic tool was applied to three experiments with different geometries and plasma conditions to test the validity of each data analysis method. The helium and hydrogen data analysis methods were tested and validated on helium and hydrogen plasmas produced in the VASIMR experiment, a plasma propulsion system concept. They gave electron temperatures and neutral densities that were consistent with other diagnostics and theory. The argon diagnostic tool was tested on argon plasmas produced in the VASIMR experiment, the Helimak experiment and the Helicon experiment. The electron temperature and neutral density obtained on both the Helimak and the Helicon experiments were consistent with other diagnostics and with theory, and validated the method of analysis. An impurity problem on the VASIMR experiment made it difficult for the data analysis to be validated.

Shape Memory Alloy is an amazing material, which can “remember” and return to its original shape when heated due to its temperature dependent phase transformation. Shape Memory Alloy wire has significant potential for application in the automobile industry due to its high ratio of energy / weight and silent actuation. However, a dependable method to measure the operating temperature of SMA wire and a reliable heat transfer model to characterize the dynamics of the SMA wire limit its widespread use in the automobile industry. This thesis presents a detailed description of the work performed to develop a reliable method for determining surface temperature of current carrying SMA wires and the development of a heat transfer correlation for natural convection cooling of heated SMA wires. The major findings of the research are as follows: When a spot welded thermocouple measures the temperature of a current carrying SMA wire, there is a “spurious voltage” ΔV added to the thermo electro-motive force (EMF) of the thermocouple as a result of a voltage drop across the two points of contact that the thermocouple wires make with the SMA wire. This leads to an erroneous temperature reading that can be higher or lower than the actual temperature depending on the direction of current flow. When the carrying current is reversed in direction, the “spurious voltage” becomes –ΔV allowing a correct temperature reading to be obtained by averaging the readings based on opposed current flow. A two-step spot welding procedure for attaching thermocouples to SMA wire can eliminate the influence of the “spurious voltage” in the temperature reading. By spot welding the thermocouple wires onto the SMA wire one by one, the thermocouple lead offset is eliminated and the thermocouple provides an accurate point source reading. Infrared thermal imaging can be a good supplement in the experiment to monitor errors in temperature readings from thermocouples. Due to the curvature of the SMA wire, the temperatures of the locations on the SMA wire that are the closest to the infrared camera represent the temperature of the SMA wire. So a line analysis across the SMA wire on the software “ThermaCAM” is required to determine the temperature of the SMA wire by infrared thermal imaging and the highest temperature on the line is the temperature of the SMA wire. A new natural convective heat transfer correlation comprising the inclination angle φ is developed based on experimental results, which can be used to predict the temperature of a SMA wire given its diameter and inclination angle. The comparisons show that the new correlation agrees with existing correlations in a vertical orientation and for small Rayleigh numbers (0.001 < RaD < 0.05) in the horizontal orientation. The correlation developed in this work for horizontal orientation tends to overestimate values of Nusselt numbers as predicted in other correlations when the Rayleigh number is high (0.05 < RaD < 0.6). It is speculated that this overestimation can be attributed to a temperature distortion associated with thermocouple measurement at or near ambient pressure conditions.

Le diamant est souvent défini comme le matériau ultime pour la réalisation de composants à semi-conducteurs pour des applications d'électronique de puissance. Bien que plusieurs interrupteurs de puissance en diamant soient parus à l'échelle mondiale, ils sont à l'heure actuelle à l'état de prototype et de preuve de concept. Il est donc nécessaire de comprendre leurs mécanismes de fonctionnement afin de pouvoir utiliser tout leur potentiel dans des convertisseurs de puissance. Dans cette thèse, l'analyse se focalise sur des diodes Schottky en diamant de structure pseudo-verticale. Des caractérisations statiques et en commutation des diodes Schottky ont tout d'abord été réalisées. Elles ont permis d'extraire les caractéristiques des composants et de les intégrer dans des convertisseurs de puissance afin d'analyser leur comportement en commutation. L'utilisation et la gestion des diodes dans des convertisseurs ont ensuite été étudiées. Ces études ont permis de proposer des modifications de la structure des diodes afin d'améliorer la performance de leur intégration dans des convertisseurs de puissance. Finalement l'analyse théorique des performances d'une diode Schottky en diamant dans un convertisseur est réalisée. La comparaison entre ces performances et celles d'une diode Schottky en SiC a permis de mettre en évidence les particularités des composants en diamant ainsi que les bénéfices qu'ils peuvent apporter à l'électronique de puissance. / Diamond is considered as the ultimate semiconductor for power electronics applications. Even if diamond semiconductor devices have been realized worldwide, it is still prototype or proof of concept devices. It is then necessary to understand how do they operate to use their entire benefits in power converters. In this thesis, we focused the analysis on pseudo-vertical diamond Schottky diodes. Firstly, static and switching characterizations have been realized. They allow us to extract devices characteristics in the way to integrate them in power converters to analyze their switching abilities. Management of diodes in power converters is then studied. These studies allow us to propose device structure modifications in the way to improve diodes performances and their integration in power converters. Finally, a theoretical analysis on a diamond Schottky diode performances in a power converter is realized. It has been compared to the performances of a SiC Schottky diode. It highlights the particularities of diamond devices and the benefits they might bring to power electronics applications.

Objectives: The first aim of this diploma thesis was to analyze the functionality and effectiveness of the HACCP system in selected catering facilities. Other goals were to find out how to make a meal and find out the satisfaction of meals with a meal composition. Research Questions: 1. How is the temperature controlled at the expedition of the dishes in vessels and their direct dispatch? 2. How is the schedule plan of food delivery fulfilled? 3. How is the concrete diet created? 4. How are the borders satisfied with the composition of the diet? Methodology: A qualitative research survey was used in the practical part. There is the secondary analysis of HACCP data, a field survey by measuring temperature and participating in food distribution. In addition, a personal interview was conducted with the leader on nutritional recommendations and diet. Personal interviews with fifteen boarders were conducted. Results: The results of the survey point out the fact that, although shortcomings in the HACCP legislation and production chart have been identified, the critical control point of food temperature measurement is effective. The lunch distribution plan was respected. An increase in the critical limit at this critical control point has been proposed. It was recommended to introduce a critical control point when receiving raw materials. It was also found that the diet was prepared according to the preferences of the boarders. The supervisor has insufficient knowledge of nutritional recommendations. A leaflet and a recipe for a healthy alternative to traditional dishes were created. Desserts prefer traditional Czech cuisine. They prefer meat dishes, frying and baking. They are not interested in adding vegetarian dishes and legumes. The gained information can also contribute to selected catering meals to other catering companies, public health workers and students in the field.

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