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Comfort temperature analysis in a historical stone churchXiao, Naiyuan January 2015 (has links)
In this thesis a church named Hamrånge, located North of the town Gävle in Sweden, has been studied. In this church thermal comfort is a problem that need to be considered. There is poor insulation and air leakage in the building envelope. And appearance doesn't allow to add any additional insulation, becauce people want to keep its original appearance. In cold weather the church is heated by bench heaters and radiators through direct electicity. / Energy system
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Ionospheric Scintillation Prediction, Modeling, and Observation Techniques for the August 2017 Solar EclipseBrosie, Kayla Nicole 16 August 2017 (has links)
A full solar eclipse is going to be visible from a range of states in the contiguous United States on August 21, 2017. Since the atmosphere of the Earth is charged by the sun, the blocking of the sunlight by the moon may cause short term changes to the atmosphere, such as density and temperature alterations. There are many ways to measure these changes, one of these being ionospheric scintillation. Ionospheric scintillation is rapid amplitude and phase fluctuations of signals passing through the ionosphere caused by electron density irregularities in the ionosphere. At mid-latitudes, scintillation is not as common of an occurrence as it is in equatorial or high-altitude regions. One of the theories that this paper looks into is the possibility of the solar eclipse producing an instability in the ionosphere that will cause the mid-latitude region to experience scintillations that would not normally be present. Instabilities that could produce scintillation are reviewed and altered further to model similar conditions to those that might occur during the solar eclipse. From this, the satellites that are being used are discuses, as is hardware and software tools were developed to record the scintillation measurements. Although this work was accomplished before the eclipse occurred, measurement tools were developed and verified along with generating a model that predicted if the solar eclipse will produce an instability large enough to cause scintillation for high frequency satellite downlinks. / Master of Science / A full solar eclipse is going to be visible from a range of states in the contiguous United States on August 21, 2017. Since the atmosphere of the Earth is charged by the sun, the blocking of the sunlight by the moon may cause short term changes to the atmosphere, such as density and temperature alterations. There are many ways to measure these changes, one of these being ionospheric scintillation. Ionospheric scintillation is rapid amplitude and phase fluctuations of signals passing through the ionosphere caused by electron density irregularities in the ionosphere. At mid-latitudes, scintillation is not as common of an occurrence as it is in equatorial or high-altitude regions. One of the theories that this paper looks into is the possibility of the solar eclipse producing an instability in the ionosphere that will cause the mid-latitude region to experience scintillations that would not normally be present. Instabilities that could produce scintillation are reviewed and altered further to model similar conditions to those that might occur during the solar eclipse. From this, the satellites that are being used are discuses, as is hardware and software tools were developed to record the scintillation measurements. Although this work was accomplished before the eclipse occurred, measurement tools were developed and verified along with generating a model that predicted if the solar eclipse will produce an instability large enough to cause scintillation for high frequency satellite downlinks.
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DEVELOPMENT AND APPLICATION OF COUNTERFLOW METHODS: GEITP, GEITP-CZE, TGF, and TGDFDavis, Nejea I. January 2011 (has links)
Extensive research on amino acids, and even other biochemical assays usually present in low concentration and volume face challenges using known analytical techniques for analysis of traces amounts. Some limiting factors are the achievable efficiency, sensitivity (resulting from instrument limit of detection and/or experimental methods), volume requirement, and total analysis time. Counterflow electrofocusing techniques combining forces of electrophoresis and bulk flow (pressure driven flow and/or electroosmotic flow) provides a basis for the development of alternative detection techniques geared towards improving peak efficiency, sensitivity and time. The work presented gives a vivid description of recently developed capillary counterflow techniques: gradient elution isotachophoresis (GEITP) using UV detection, GEITP coupled to Capillary Zonal Electrophoresis (GEITP-CZE), temperature gradient focusing (TGF), and temperature gradient denaturing focusing (TGDF). A first demonstration of GEITP using UV detection was applied to enrichment and separation of tyrosine and tryptophan under optimized conditions. Primarily, separation is achieved as the result of the difference in electrophoretic velocity of analytes in a discontinuous buffer system. First, a plug of sample is allowed to preconcentrate (or enrich) between high mobility leading electrolyte (LE) and low mobility trailing electrolyte (TE) under controlled hydrodynamic pressure and continuous injection. This preconcentration is initiated outside the capillary in a conductivity bubble. Although analyte focus according to their electrophoretic velocity, the inclusion of spacer molecule in sample matrix was instrumental in achieving separation with tradeoff between analyte resolution and enrichment. Gradient produced results from reduction in pressure as sample is loaded on column. Separation using this technique is a one step process. A hybrid method marking the first successful coupling of GEITP to CZE with laser induced fluorescence detection was used for separation of six fluorescently labeled amino acids (which formulates the Mars-7). An eleven minute separation was achieved under optimized conditions. A proof-of-concept demonstration of TGF with LIF detection showed focusing and separation of fluorescein and carboxyfluorescein dye molecules, and carboxyfluorescein-labeled glutamate and aspartate. The generation of null focusing points along the thermal separation column (set between 80-20oC) was produced in collaboration with continuous sample injection, discontinuous buffer system and balancing of counterflows (electrophoresis and bulk flow). Preliminary results showed stability in instrument. The TGDF method carried out on a TGF apparatus is a modification to the temperature gradient gel electrophoresis and denaturing gradient gel electrophoresis methods. In principle, TGDF primarily achieves focusing and separation on a thermal separation column (set between 20 to 80 oC) as a result of conformational changes. It is currently being developed for the detection and simultaneous separation of single and double stranded DNA. Preliminary results show enrichment of wildtype and mutant synthetic DNA strands (containing twenty-four base pairs in sequence) in different buffer matrices. / Chemistry
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Thermo hydraulic behaviour of unstaturated salt aggregatesCastagna, Salvatore 21 May 2007 (has links)
En el siglo pasado se ha desarrollado una nueva energía: la nuclear. Su aplicación comprende tanto el campo militar como el campo civil. Unos de los aspectos más interesantes es el uso de esta energía para la producción de electricidad de uso civil. El combustible nuclear es de larga duración: unas barras de uranio pueden llegar a producir energía eléctrica durante una década aproximadamente. Sin embargo, a mediados del siglo pasado se planteó el problema de los residuos nucleares. Este problema es muy complejo por que, aunque la duración del combustible sea de una década, el periodo de decaimiento es del orden de siglos. Esta tesis quiere aportar su granito de arena a esta nueva rama de la ciencia nuclear, estudiando algunos aspectos del comportamiento geotécnico de los agregados de sal, para su uso como material de relleno en los depósitos definitivos de los residuos nucleares de mayor peligrosidad.La regla fundamental de diseño de dichos depósitos es que su función debe desarrollarse sin la ayuda del hombre o de máquinas y que la misma naturaleza tiene que ser quien proteja al hombre del riesgo de radiaciones durante el transcurso de los siglos. Parece que al día de hoy la solución mundialmente aceptada es la de un depósito profundo en formaciones rocosas, a veces utilizando antiguas minas, incluso de sal. Se prevé que entre esta década y la próxima entrarán en funcionamiento varios de estos depósitos en los países en que la investigación en este área está más avanzada.En Europa se está haciendo un esfuerzo común, bajo supervisión de la Unión Europea y por medio de proyectos de investigación, para estudiar el funcionamiento del almacenamiento y la difusión de los resultados de esos estudios entre los miembros de la Unión Europea, a fin de dar el mayor provecho a las diferentes investigaciones que en la actualidad se están desarrollando en todos los centros de investigación de Europa.Esta tesis trata sobre el comportamiento termo hidráulico de los agregados de sal debido a las altas temperaturas que el decaimiento de los residuos nucleares produce. Este fenómeno crea unos efectos en los materiales de relleno y en la formación de base de alrededor del deposito.La tesis tiene un desarrollo básicamente experimental. En el laboratorio se realizaron fundamentalmente dos ensayos; el primero permitió determinar la curva de retención de los agregados de sal altamente compactados. Para ello se utilizó la técnica de traslación de ejes para aplicar la succión matricial y se construyó una placa de succión apta a los materiales salinos para la realización de estos ensayos.Este ensayo permitió determinar el comportamiento de una propiedad básica de los materiales salinos no saturados, sus resultados pudieron aplicarse al resto de los trabajos que se realizaron con posterioridad en esta tesis.El objeto del segundo ensayo de laboratorio fue reproducir los fenómenos de variación de porosidad debidos a la presencia de una diferencia de temperatura en las extremidades de la muestra. Dicho ensayo tiene una importancia fundamental para los almacenamientos profundos, porque los residuos radiactivos serán una fuente de calor durante varios siglos y la presencia de elevadas temperaturas induce fenómenos de flujo y transporte en el contacto con los contenedores de carburante nuclear agotado. Además, en el caso de los agregados de sal, a estos fenómenos cabe añadir el intercambio de sal entre la fase sólida y la líquida (precipitación /disolución).Para desarrollar estas pruebas de laboratorio, se dedicó una parte importante de la investigación al desarrollo y comprobación del equipo de ensayo, siendo éste poco convencional y completamente novedoso. Este último ensayo, en su segunda fase, fue convalidado mediante un modelo numérico (CODE BRIGHT). Los resultados del modelo numérico han permitido confirmar todo cuanto se determinó en la fase experimental y la importancia de la succión matricial en estos fenómenos.
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A Study of Dynamical Behaviors of LD-pumped Microchip Nd:GdVO4 laserLin, Chi-Ching 30 August 2009 (has links)
This paper have investigated the dual polarization oscillations (DPO) and associated dynamical behaviors in laser-diode-pumped microchip Nd:GdVO4 laser. Some optical properties of Nd:YAG, Nd:YVO4, and Nd:GdVO4 laser materials are compared. The higher thermal conductivity of Nd:YAG makes it suitable for higher-power applications. The larger stimulated-emission coefficient of Nd:YVO4 material makes it favorable for increasing light-light conversion efficiency. However, Nd:GdVO4 material has high thermal conductivity and large stimulated-emission coefficient. Many experiments done to study Nd:GdVO4 crystal¡¦s properties focused on the efficiency of high power generation. Orthogonal linearly-polarized emissions could be obtained in fluorescence spectrum of Nd:GdVO4, but DPO did not be observed in Nd:GdVO4 laser possessing a large fluorescence anisotropy with laser-diode pumping. In this paper, DPO on different transitions in laser-diode-pumped microchip Nd:GdVO4 are obtained for the first time. Furthermore, more effective generation of dual polarization oscillations is affected by the pumping conditions associated with different temperature gradient than different pumping power density. The results imply that DPO can be generated without having to use additional optical elements and Nd:GdVO4 material is suitable for the construction of compact DPO lasers.
Laser properties including oscillation spectra, input-output characteristics, pump-dependent pattern formations and noise power spectra are studied experimentally. A poor mode matching between the pump beam and lasing beam results in the generation of high order transverse modes. The observed anti-phase dynamics have been explained in terms of the reduced three-dimensional cross-saturation of population inversions among orthogonally-polarized modes. The study of dynamics of microchip Nd:GdVO4 lasers under pump modulation has also been reported in this paper. Different phase correlations among laser modes are obtained by tuning the modulation frequency and amplitude. The observed dynamical states are reproduced theoretically by rate equations of multimode class-B lasers including the cross-saturation among individual modes and the pump modulation.
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Analysis of three ventilation systems in an office: Mixing, displacement and confluent jet ventilation system. : Analysis of temperature gradient, tracer gas and thermal comfort.Peña Malo, Julio J., Panjkov Zafra-Polo, Igor January 2013 (has links)
Scandinavian countries have always been the first in investigation and development of new ventilation systems. In the last years, engineers from Finland and Sweden are studying a new ventilation system known “Confluent jet ventilation system” which is trying to improve displacement and mixing results. The aim of this thesis master is to study the behaviour of three different ventilation systems, mixing ventilation, displacement ventilation and confluent jet ventilation, in an office room by mean of three analysis, temperature gradient analysis, tracer gas analysis and thermal comfort analysis, and to compare them to know if the new one, confluent jet, increases the performance of mixing or displacement ventilation system. In case of confluent jet ventilation system, there were two different cases: one with the supply air device at 2.2m high, and the other with it at 1.7m high to compare which one was the correct position and gets the best results. For each studied system 3 different cases were analyzed, having the same parameters each one of them for the three ventilation systems.The measurements were taken in an office room located in the laboratory of the University of Gävle, Högskolan I Gävle, in collaboration with the Finnish company specialized in ventilation systems, Stravent. For temperature gradient analysis, ten sensors took temperatures from the low level, 0.1m high, to the top level of the room, 2.4m, during all the time that the other measurements were being taken. For tracer gas analysis, a data logger took measurements of the contaminant concentration, N2O, from when the contaminant was thrown into the room until it disappeared following a Decay curve. Lastly, in thermal comfort analysis 4 transducers took measurements each 12 minutes of air temperature, operative temperature, air velocity and air humidity are measured in 6 different points inside the office room and at 3 different heights, 0.1m, 1.1m and 1.7m. After analyzing the results of temperature gradient, tracer gas and thermal comfort the best results were obtained by confluent jet system with the supply air device at 2.2m in case of temperature gradient, since the difference of temperatures between the low and the top level were the minimum and contaminants and indoor air were not in a homogeneous mixing. In case of tracer gas, the results about air change efficiency were not the expected because they showed a well-mixed situation for every system and it should not have been like that. It was caused for the influence of a cooling system situated in the ceiling of the room and the temperature difference between inside and outside the room that affected more than expected. Finally, in thermal comfort analysis, the best results were obtained by confluent jet ventilation, therefore in case of the supply air device at 2.2m and in case of it at 1.7m. To sum up, taking account the results achieved, the confluent jet ventilation got the best results and showed that it is a new ventilation system that must be taken in consideration in the following buildings. Between supply air device at 2.2m and 1.7m the results were very similar, but a bit better in case of the highest height.
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Subcritical turbulence in the Mega Ampere Spherical Tokamakvan Wyk, Ferdinand January 2016 (has links)
The transport of heat out of tokamak plasmas by turbulence is the dominant mechanism limiting the performance of fusion reactors. Turbulence can be driven by the ion temperature gradient (ITG) and suppressed by toroidal equilibrium scale sheared flows. Numerical simulations attempting to understand, and ultimately reduce, turbulence are crucial for guiding the design and optimisation of future reactors. In this thesis, we investigate ion-scale turbulence by means of local gyrokinetic simulations in the outer core of the Mega Ampere Spherical Tokamak (MAST).We perform a parameter scan in the values of the ITG and the flow shear. We show that nonlinear simulations reproduce the experimental ion heat flux and that the experimentally measured values of the ITG and the flow shear lie close to the turbulence threshold. We demonstrate that the system is subcritical in the presence of flow shear, i.e., the system is formally stable to small perturbations, but transitions to a turbulent state given a large enough initial perturbation. We propose a scenario for the transition to subcritical turbulence previously unreported in tokamak plasmas: close to the threshold, the plasma is dominated by a low number of coherent long-lived structures; as the system is taken away from the threshold into the more unstable regime, the number of these structures increases until they fill the domain and a more conventional turbulence emerges. We make quantitative comparisons of correlation properties between our simulations and experimental measurements of ion-scale density fluctuations from the MAST BES diagnostic. We apply a synthetic diagnostic to our simulation data and find reasonable agreement of the correlation properties of the simulated and experimental turbulence, most notably of the correlation time, for which significant discrepancies were found in previous numerical studies of MAST turbulence. We show that the properties of turbulence are essentially functions of the distance to threshold, as quantified by the ion heat flux. We find that turbulence close to the threshold is strongly affected by flow shear, whereas far from threshold, the turbulence resembles a conventional ITG-driven, zonal-flow damped regime.
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Padrões espaciais e temporais da composição e atividade do bacterioplâncton no estuário da Lagoa dos Patos (RS, Brasil)They, NG Haig January 2013 (has links)
Tese(doutorado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2013. / Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-10-15T11:55:34Z
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Previous issue date: 2013 / A composição (CCB) e a atividade (perfil fisiológico - PFCB) da comunidade bacteriana foram investigadas no estuário da Lagoa dos Patos e região costeira adjacente através de amostragem tipo-Lagrangiana, Euleriana e ao longo de um transecto para responder três perguntas: i) existe um padrão de recorrência
(estabilidade) da CCB e PFCB em diferentes faixas de salinidade? ii) a CCB e PFCB respondem a diferentes escalas temporais e espaciais, inclusive a fenômenos climáticos globais que afetam a hidrodinâmica do estuário, tais como o “El Niño Southern Oscillation” (ENSO) ? iii) que fatores, além da salinidade, afetam a CCB e a PFCB? A CCB e a PFCB estiveram associadas à hidrodinâmica do estuário, tanto em escalas curtas (entrada de cunha salina), médias (sazonal) e largas (ENSO). Isto porquê a hidrodinâmica condiciona a variabilidade da salinidade e secundariamente o seston, nutrientes inorgânicos dissolvidos e substratos orgânicos, que afetam as bactérias. A CCB foi
primariamente estruturada pela salinidade, seguindo o padrão normalmente encontrado na literatura para estuários, com comunidades características de água salgada e doce. Já a PFCB teve maior influência da quantidade de
nutrientes e substratos e de maneira indireta da salinidade. De maneira geral, a atividade bacteriana foi menor em águas salgadas mais oligotróficas. Entretanto, grande atividade bacteriana foi observada em água salgada rica em nutrientes que penetrava no estuário. A maior concentração de nutrientes na água salgada pode ter sido resultado de ressuspensão de sedimento, ou ingresso de água costeira previamente enriquecida com água estuarina. / The composition (BCC) and activity (community level physiological profiles, CLPP) of the bacterial community were investigated in the Patos Lagoon estuary and adjacent coastal region through Lagrangian-like, Eulerian and
transect samplings in order to answer three questions: i) is there a pattern of recurrence (stability) of the BCC and CLPP in different salinity ranges? ii) does the BCC and CLPP respond to different temporal and spatial scales, including global climate phenomena that affect the estuary hydrodynamics like El Niño Southern Oscillation (ENSO)? iii) which factors apart from salinity affect the BCC and CLPP? The BCC and CLPP were associated to the estuary
hydrodynamics, at short- (salt wedge entrance), meso- (seasonal) and largescales
(ENSO). This is because the hydrodynamics conditions the variability of salinity and secondarily the seston, dissolved inorganic nutrients and organic substrates, which in turn affect bacteria. The BCC was primarily structured by salinity, following the pattern commonly found in the literature for estuaries, with characteristic fresh- and saltwater communities. The CLPP had higher influence of the amount of nutrients and substrates and indirectly of salinity. In general the bacterial activity was lower in oligotrophic, saltier waters. However, high
bacterial activity was observed in nutrient-rich saltwater that entered the estuary. The higher concentration of nutrients in saltwater is likely the result of ressuspension of the sediment or ingress of coastal water previously enriched with estuarine water.
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Typical and Darkened Portland Cement Concrete Pavement: Temperature, Moisture, and Roughness AnalysesWaters, Tenli 01 June 2016 (has links)
The objectives of this research were to 1) investigate the effects of lower concrete albedo on the thermal behavior of concrete pavement by directly comparing temperatures and moisture contents of typical and darkened concrete pavements and 2) investigate changes in roughness of both typical and darkened concrete pavements as a result of changes in temperature and moisture gradients. The scope of the research included instrumentation, testing, and analysis of typical and darkened concrete pavements constructed in northern Utah.Procedures related to field testing included infrared thermography, thermocouple readings, sensor data collection, and roughness surveys. Elevation surveys and albedo measurements were also performed to further characterize the site. Procedures related to laboratory testing included elastic modulus, compressive strength, rapid chloride permeability, thermal conductivity, and Schmidt rebound hammer testing of cylinders prepared from typical and darkened concrete.When considered over the entire monitoring period, the average surface temperatures of the darkened pavement were higher than those of the typical pavement by 3.3°F, and the average subsurface temperatures of the darkened pavement were higher than those of the typical pavement by 3.1°F. A strong positive correlation exists between the air temperature and both the surface and the subsurface pavement temperatures. The difference between both the surface and subsurface temperatures of the darkened and typical pavements decreases as the air temperature decreases. The results of a simple linear regression suggest that, when the air temperature is 32°F, the surface temperature of the darkened concrete is just 0.2°F higher than that of the typical concrete and the subsurface temperature of the darkened concrete is 1.1°F higher than that of the typical concrete. The difference in surface temperature is expected to be 0°F when the air temperature is 30.5°F, while the difference in subsurface temperature is expected to be 0°F when the air temperature is 17.9°F. Therefore, the darkened pavement is unlikely to melt snow and ice faster than the typical pavement or provide significantly greater frost protection to subsurface layers and buried utilities during winter for conditions similar to those in this research. The roughness measurements for the typical pavement exhibit much more daily variability than seasonal variability. The roughness measurements for the darkened pavement also exhibit more daily variability than seasonal variability but less overall variability than that of the typical pavement. Neither pavement temperature gradient nor moisture gradient appears to be correlated to roughness for either the typical pavement or the darkened pavement.
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Stanovení standardní nejistoty při konfirmaci teplotní komory / Evaluation of standard uncertainty of Climatic ChamberDojava, Václav January 2018 (has links)
The thesis deals with the problematics of confirmation of the climatic chamber CTS 65/50, which is a component of CVVOZE testing laboratory. Theoretical part deals with the analysis and description of methods of confirmation of climatic chambers based primarily on technical standards. This part then contains a brief description of a theory of measurement uncertainty. Practical part deals with the design of measurement procedure, which was used for confirmation measurement of ten temperature setpoints. This section then also contains an analysis of the measured data with the evaluation of standard combined uncertainty of temperature measurement. The last part contains an evaluation of the confirmation results, which were the basis for the determination of whether the climatic chamber meets the requirements for the steady-state temperature stability inside the workspace resulting from the standards for the climatic testing
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