Дисертації з теми "Temperature and Heat Flux characterization"
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Virk, Akashdeep Singh. "Heat Transfer Characterization in Jet Flames Impinging on Flat Plates." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/52985.
Повний текст джерелаMaster of Science
Genc, Gence. "Serpentinization-assisted deformation processes and characterization of hydrothermal fluxes at mid-ocean ridges." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43725.
Повний текст джерелаBaker, Karen Irene. "Unsteady surface heat flux and temperature measurements." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-12042009-020124/.
Повний текст джерелаLartz, Douglas John. "Feedforward temperature control using a heat flux microsensor." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06302009-040309/.
Повний текст джерелаPullins, Clayton Anthony. "High Temperature Heat Flux Measurement: Sensor Design, Calibration, and Applications." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/27789.
Повний текст джерелаPh. D.
Raphael-Mabel, Sujay Anand. "Design and Calibration of a Novel High Temperature Heat Flux Sensor." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/31688.
Повний текст джерелаMaster of Science
Hoguane, Antonio Mubango. "Hydrodynamics, temperature and salinity in mangrove swamps in Mozambique." Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318565.
Повний текст джерелаVega, Thomas. "Quantification of the Fire Thermal Boundary Condition." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/78052.
Повний текст джерелаMaster of Science
Tziranis, Alexander Konstantinos 1968. "Temperature, heat flux, and velocity measurements in oscillating flows with pressure variations." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/12790.
Повний текст джерелаVita.
Includes bibliographical references (leaves 99-101).
by Alexander Konstantinos Tziranis.
M.S.
Kaufman, Melissa Rachel Steinberg. "Upwelling dynamics off Monterey Bay : heat flux and temperature variability, and their sensitivities." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59942.
Повний текст джерела"June 2010." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 64-66).
Understanding the complex dynamics of coastal upwelling is essential for coastal ocean dynamics, phytoplankton blooms, and pollution transport. Atmospheric-driven coastal upwelling often occurs when strong alongshore winds and the Coriolis force combine to displace warmer surface waters offshore, leading to upward motions of deeper cooler, nutrient-dense waters to replace these surface waters. Using the models of the MIT Multidisciplinary Simulation, Estimation, and Assimilation System (MSEAS) group, we conduct a large set of simulation sensitivity studies to determine which variables are dominant controls for upwelling events in the Monterey Bay region. Our motivations include determining the dominant atmospheric fluxes and the causes of high-frequency fluctuations found in ocean thermal balances. We focus on the first upwelling event from August 1- 5, 2006 in Monterey Bay that occurred during the Monterey Bay 06 (MB06) at-sea experiment, for which MSEAS data-assimilative baseline simulations already existed. Using the thermal energy (temperature), salinity and momentum (velocity) conservation equations, full ocean fields in the region as well as both control volume (flux) balances and local differential term-by-term balances for the upwelling event events were computed. The studies of ocean fields concentrate on specific depths: surface-0m, thermocline-30m and undercurrent- 150m. Effects of differing atmospheric forcing contributions (wind stress, surface heating/cooling, and evaporation-precipitation) on these full fields and on the volume and term-by-term balances are analyzed. Tidal effects are quantified utilizing pairs of simulations in which tides are either included or not. Effects of data assimilation are also examined. We find that the wind stress forcing is the most important dynamical parameter in explaining the extent and shape of the upwelling event. This is verified using our large set of sensitivity studies and examining the heat flux balances. The assimilation of data has also an impact because this first upwelling event occurs during the initialization. Tidal forcing and, to a lesser extent, the daily atmospheric and data assimilation cycles explain the higher frequency fluctuations found in the volume averaged time rate of change of thermal energy.
by Melissa Rachel Steinberg Kaufman.
S.B.
D'Elia, Christopher. "Development of Local Transient Heat Flux Measurements in an Axisymmetric Hybrid Rocket Nozzle." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1349.
Повний текст джерелаLaMontagne, Aurele. "Characterization and quantification of ground heat flux for late season shallow snow." [Boise, Idaho] : Boise State University, 2009. http://scholarworks.boisestate.edu/td/48/.
Повний текст джерелаMagee, Michael P. "Thermal boundary resistance in a high temperature thin-film superconductor under varying heat flux." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA326312.
Повний текст джерела"December 1996." Thesis advisor(s): Matthew Kelleher, Pat E. Phelan. Includes bibliographical references (p. 73-75). Also available online.
Bezuidenhout, Johannes Jurie. "Convective heat flux determination using surface temperature history measurements and an inverse calculation method." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/35706.
Повний текст джерелаThe objective of this study is therefore to develop a cost-effective single gage that can be used to measure both skin friction and heat flux. The method proposed in this study is to install a coaxial thermocouple into an existing skin friction gage to measure the unsteady temperature on the surface of the gage. By using the temperature history and a computer program the heat flux through the surface can be obtained through an iterative guessing method. To ensure that the heat flux through the gage is similar to the heat flux through the rest of the surface, the gage is manufactured of a material very similar to the rest of the surface.
Walker developed a computer program capable of predicting the heat flux through a surface from the measured surface temperature history. The program is based on an inverse approach to calculate the heat flux through the surface. The biggest advantages of this method are its stability and the small amount of noise induced into the system. The drawback of the method is that it is limited to semi-infinite objects. For surfaces with a finite thickness, a second thermocouple was installed into the system some distance below the first thermocouple. By modifying the computer program these two unsteady temperatures can be used to predict the heat flux through a surface of finite thickness.
As part of this study, the effect of noise induced by the Cook-Felderman technique, found in the literature were investigated in detail and it was concluded that the method proposed in this study is superior to this Cook-Felderman method. Heat flux measurements compared well with measurements recorded with heat flux gages. In all cases evaluated the difference was less than 20%. It can therefore be concluded that heat flux gages on their own can measure surface heat flux very accurately. These gages are however too large to install in a skin-friction gage. The method introduced in this study is noisier than the heat flux gages on their own, but the size which is very important, is magnitudes smaller when using a coaxial thermocouple, to measure the surface temperature history.
Master of Science
Wikström, Patrik. "A study of surface temperature and heat flux estimations in heating processes by solving an Inverse Heat Conduction Problem." Licentiate thesis, KTH, Materials Science and Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-605.
Повний текст джерелаThe topic of this thesis is estimation of the dynamic changes of the surface temperatureand heat flux during heating processes by using an inverse method. The local transient surface temperature and heat flux of a steel slab are calculated based on measurements in the interior of the slab.
The motivations for using an inverse method may be manifold. Sometimes, especially in the field of thermal engineering, one wants to calculate the transient temperature or heat flux on the surface of a body. This body may be a slab, or billet in metallurgical applications. However, it may be the case that the surface for some reason is inaccessible to exterior measurements with the aid of some measurement device. Such a device could be a thermocouple if contact with the surface in question is possible or a pyrometer if an invasive method is preferred. Sometimes though, these kinds of devices may be an inappropriate choice. It could be the case that the installation of any such device may disturb the experiment in some way or that the environment is chemically destructive or just that the instruments might give incorrect results. In these situations one is directed to using an inverse method based on interior measurements in the body, and in which the desired temperature is calculated by a numerical procedure.
The mathematical model used was applied to experimental data from a small scale laboratory furnace as well as from a full scale industrial reheating furnace and the results verified that the method can be successfully applied to high temperature thermal applications.
Wikström, Patrik. "A study of surface temperature- and heat flux estimations in heating processes by solving an Inverse Heat Conduction Problem /." Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-605.
Повний текст джерелаJacobi, Christoph, and Daniel Mewes. "Heat flux classification of CMIP5 model results using self-organizing maps." Universität Leipzig, 2019. https://ul.qucosa.de/id/qucosa%3A74181.
Повний текст джерелаDie Methode der Self-Organizing Maps (SOMs) wurde auf acht CMIP5-Modelle mit jeweils zwei verschiedenen Treibhausgasszenarien angwendet. Die SOMs wurden für jedes Modell und jede der beiden Modelläufe für den horizontalen Temperaturfluss in 500 hPa im Winter erstellt. Zusätzlich zu den aus der Analyse von Reanalyse-Daten erwarteten drei Transportwegen (pazifisch, atlantisch und sibirisch/kontinental) wurden Überlagerungen dieser gefunden. Es konnte gezeigt werden, dass die grundsätzliche Struktur der Transporte indirekt abhängig von der Treibhausgaskonzentration ist. Die Ergebnisse deuten darauf hin, dass sich die generelle Struktur des atmosphärischen Transports von einer stabilen zyklonalen Bewegung über dem Nordpol sich zu Transporten verschiebt, welche meridionale Transporte über den Nortdatlantik und den Nordpazifik in die Arktis führen.
Treiss, Stephanie. "TIME-DEPENDENT SURFACE TEMPERATURE and HEAT FLUX MEASUREMENTS on a SINGLE CYLINDER ENGINE HEAD and LINER." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1512061036731254.
Повний текст джерелаFinol, Parra Carlos. "Heat transfer investigations in a modern diesel engine." Thesis, University of Bath, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512318.
Повний текст джерелаO'Brien, Timothy J. "The Application of BioHeat Perfusion Sensors to Analyze Preservation Temperature and Quantify Pressure Ischemia of Explanted Organs." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/51607.
Повний текст джерелаMaster of Science
Nam, Jae-Do. "Polymer matrix degradation : characterization and manufacturing process for high temperature composites /." Thesis, Connect to this title online; UW restricted, 1991. http://hdl.handle.net/1773/9867.
Повний текст джерелаPaik, Sokwon. "Spatially resolved temperature and heat flux measurements for slow evaporating droplets heated by a microfabricated heater array." Diss., Texas A&M University, 2006. http://hdl.handle.net/1969.1/3819.
Повний текст джерелаPedotto, Cristina. "Using IR thermography to determine the heat flux removed by spray cooling a high-temperature metallic surface." Thesis, Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/1044.
Повний текст джерелаPulliam, Wade Joseph. "Development of Fiber Optic Aerodynamic Sensors for High Reynolds Number Supersonic Flows." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/26325.
Повний текст джерелаPh. D.
Fox, Bronwyn Louise. "The manufacture, characterization and aging of novel high temperature carbon fibre composites." View thesis entry in Australian Digital Theses Program, 2001. http://thesis.anu.edu.au/public/adt-ANU20011207.114246/index.html.
Повний текст джерелаTjahjono, Richard. "Correlation Between Nasal Mucosal Temperature Change and Perception of Nasal Patency." Thesis, University of Sydney, 2021. https://hdl.handle.net/2123/25547.
Повний текст джерелаCaramori, Paulo Henrique. "Structural analysis of airborne flux traces and their link to remote sensing of vegetation and surface temperature." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41012.
Повний текст джерелаMyers, Philip D. Jr. "Additives for Heat Transfer Enhancement in High Temperature Thermal Energy Storage Media: Selection and Characterization." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5749.
Повний текст джерелаMentré-Le, Sant Véronique. "Amelioration des methodes de mesure du flux par la technique des temperatures superficielles." Paris 6, 1988. http://www.theses.fr/1988PA066416.
Повний текст джерелаJiang, Hua. "Effect of Changes in Flow Geometry, Rotation and High Heat Flux on Fluid Dynamics, Heat Transfer and Oxidation/Deposition of Jet Fuels." University of Dayton / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1300553102.
Повний текст джерелаWasson, Rachel Ann. "Separation of the Heat Transfer Components for Diffusion Flames Impinging onto Ceilings." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/50588.
Повний текст джерелаMaster of Science
Gustafsson, David. "Land surface heat exchange over snow and frozen soil." Licentiate thesis, KTH, Land and Water Resources Engineering, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1231.
Повний текст джерелаThe energy exchange in the soil-snow-vegetation-atmospheresystem was studied to improve the quantitative knowledge of thegoverning processes. The lack of such knowledge contributes tothe uncertainty in the applicability of many existing modelsindependent of the temporal or spatial scale. The theoreticalbackground and available methods for measurements and numericalsimulations were reviewed. Numerical simulation models andavailable data sets representing open land and boreal forestwere evaluated in both diurnal and seasonal time-scales.Surface heat fluxes, snow depth, soil temperatures andmeteorological conditions were measured at an agriculturalfield in central Sweden over two winters, 1997-1999. Twoone-dimensional simulation models of different complexity wereused to simulate the heat and water transfer in thesoil-snow-atmosphere system and compared with the measurements.Comparison of simulated and observed heat fluxes showed thatparameter values governing the upper boundary condition weremore important than the formulation of the internal mass andheat balance of the snow cover. The models were useful toevaluate the lack of energy balance closure in the observedsurface heat fluxes, which underlined the importance ofimproved accuracy in eddy correlation measurements of latentflow during winter conditions.
The representation of boreal forest in the land surfacescheme used within a weather forecast model was tested with athree-year data set from the NOPEX forest site in centralSweden. The formulation with separate energy balances forvegetation and the soil/snow beneath tree cover improvedsimulation of the seasonal and diurnal variations of latent andsensible heat flux compared with an older model version.Further improvements of simulated surface heat fluxes could beexpected if the variation of vegetation properties within andbetween years and a new formulation of the boundary conditionsfor heat flux into the soil is included.
Keywords: Surface energy balance, Snow, Boreal forest,SVAT models, Eddy-correlation Measurements, Latent heat flux,Sensible heat flux, Net radiation, Soil temperature,Aerodynamic roughness, Surface resistance
QC 20100614
Choi, Keum-Ran. "3D thermal mapping of cone calorimeter specimen and development of a heat flux mapping procedure utilizing an infrared camera." Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-020205-215634/.
Повний текст джерелаKeywords: temperature measurement; heat flux maps; Cone Calorimeter; three-dimensional heat conduction; fire growth models; retainer frame; ceramic fiberboard; edge effect; one-dimensional heat conduction; heat flux mapping procedure; infrared camera; specimen preparation; edge frame; one-dimensional heat conduction model; thermal properties. Includes bibliographical references (p.202-204).
Chu, Yi-Fei. "The incorporation of hourly goes data in a surface heat flux model and its impacts on operational temperature predictions in bodies of water /." The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu14879491500689.
Повний текст джерелаPENTELLA, MARIANO. "Characterization of magnetic materials at extreme ranges of field, temperature, and permeability." Doctoral thesis, Politecnico di Torino, 2022. http://hdl.handle.net/11583/2964790.
Повний текст джерелаEdy, Jean-Luc. "Application de la photoluminescence pour la mesure des flux thermiques en soufflerie hypersonique à rafales." Valenciennes, 1995. https://ged.uphf.fr/nuxeo/site/esupversions/b8f44f3d-2475-494b-9670-b3b708b9c821.
Повний текст джерелаAhlswede, Benjamin James. "What to plant and where to plant it; Modeling the biophysical effects of North America temperate forests on climate using the Community Earth System Model." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/74269.
Повний текст джерелаMaster of Science
Nagaiah, Narasimha. "NOVEL CONCEPTUAL DESIGN AND ANLYSIS OF POLYMER DERIVED CERAMIC MEMS SENSORS FOR GAS TURBINE ENVIRONMENT." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4086.
Повний текст джерелаM.S.M.E.
Department of Mechanical, Materials and Aerospace Engineering;
Engineering and Computer Science
Mechanical Engineering
White, Kathleen Madara. "Low Temperature Synthesis and Characterization of Some Low Positive and Negative Thermal Expansion Materials." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11582.
Повний текст джерелаDiao, Zhaojin. "CHARACTERIZATION OF METHANE-AIR DIFFUSION FLAMES FOR FLAME SYNTHESIS APPLICATION THROUGH OPTICAL DIAGNOSTICS." UKnowledge, 2018. https://uknowledge.uky.edu/me_etds/121.
Повний текст джерелаShirodkar, Rakesh. "An Investigation on Radiometric Measurements of Subterranean Heat Sources." Scholar Commons, 2010. https://scholarcommons.usf.edu/etd/1768.
Повний текст джерелаWitter, Jason Daniel. "A Two Part Thesis: Diurnal Soil Temperature Effects Within the GLOBE® Program Dataset and Pharmaceutical Compounds in the Wastewater Process Stream in Northwest Ohio." University of Toledo / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1208865262.
Повний текст джерелаVenter, Daniel Petrus Rocco. "Friction factors and nusselt numbers for laminar flow in ducts / Daniel Petrus Rocco Venter." Thesis, North-West University, 2009. http://hdl.handle.net/10394/3995.
Повний текст джерелаThesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2009.
Rizk, Rania. "Refroidissement passif de batteries lithium pour le stockage d'énergie." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMC228.
Повний текст джерелаThis thesis deals with the passive cooling of lithium-ion batteries. It consists of two large parts. The first part is an experimental and numerical study of the thermal behaviour of a battery and the second part is the experimental study of a passive system for the cooling of several batteries. An experimental test bench was designed to monitor the thermal evolution of batteries subjected to different currents. The prismatic batteries studied are made of lithium-iron-phosphate and have a capacity of 60 Ah. In a first step, the thermal behaviour of a battery subjected to charge / discharge cycles is experimentally characterized. We show that the temperature is not uniform at the surface of the battery and the hottest area is identified. In a second step, a three-dimensional numerical model was developed to predict the temperature at any point of the battery. This thermal model makes it possible to predict in particular the temperatures inside the battery, not measured experimentally and this, for different currents. The model input data are from experimental trials and literature. This phase of thermal characterization of the battery is essential for the design of a cooling system. Finally, an experimental study of a passive cooling system based on heat pipes and finned plates is carried out. Several configurations are tested progressively with improvements leading finally to a system with ten heat pipes with vertical finned plates at the condenser combined with finned plates placed on the faces of the batteries
Sung, Dong Yul. "Characterization of Arabidopsis heat shock protein 70 (hsp70) gene family and microarray analysis of gene expression in response to temperature extremes." [Gainesville, Fla.] : University of Florida, 2001. http://purl.fcla.edu/fcla/etd/UFE0000356.
Повний текст джерелаTitle from title page of source document. Document formatted into pages; contains xii, 140 p.; also contains graphics. Includes vita. Includes bibliographical references.
Teichmann, Ulrich, Astrid Ziemann, Klaus Arnold, and Armin Raabe. "Akustische Tomographie und optische Scintillometertechnik zur Sondierung der atmosphärischen Grenzschicht." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-214141.
Повний текст джерелаDuring an experiment at the Iff field research station Melpitz in September 1997 for the first time two different techniques were used to determine simultaneously area averaged air temperatures (Acoustic Tomography -LIM) and line averaged sensible heat fluxes (Scintillation technique - IfT). lt could be shown that on a \'golden\' day appreciably large temperature differences occurred on this superficially considered horizontal homogeneous meadow. Because of the weak data base mostly due to difficult fetch conditions it could not be proven that these temperature differences led to the horizontal differences of vertical sensible heat fluxes and therefore to the sometimes observed non-closure of the energy balance in Melpitz
Kim, Myeongsub. "Microscale optical thermometry techniques for measuring liquid phase and wall surface temperatures." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/43754.
Повний текст джерелаAltalidi, Sulaiman Saleh. "Two-Phase Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics using Practical Enhanced Surfaces." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc1011876/.
Повний текст джерелаSILVA, Ana Paula Nunes da. "Ilha de calor urbana: diagnóstico e impactos no microclima da região metropolitana de Macapá, AP." Universidade Federal de Campina Grande, 2016. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1601.
Повний текст джерелаMade available in DSpace on 2018-08-30T13:43:17Z (GMT). No. of bitstreams: 1 ANA PAULA NUNES DA SILVA - TESE (PPGMet) 2016.pdf: 25525790 bytes, checksum: 973f4462b19d6c6616cfec5845906a37 (MD5) Previous issue date: 2016-05-06
CNPq
O objetivo deste trabalho foi verificar a ocorrência de ilha de calor urbana (ICU) e sua influência no microclima na Região Metropolitana de Macapá (RMM), situada no Nordeste da Amazônia Legal, já que esta região vem apresentando um rápido processo de urbanização. Este processo de crescimento urbano provoca mudanças na cobertura e uso do solo, que podem modificar diretamente o balanço de energia em superfície gerando modificações na atmosfera que podem variar da escala local até a regional. Para verificar o crescimento urbano da RMM utilizou-se imagens do LANDSAT TM e OLI/TIRS de cinco diferentes épocas e através da classificação supervisionada MAXVER, verificou-se a expansão da classe área construída entre 1986 e 2015, classe que subentende a malha urbana. Uma análise climática com dados de precipitação e temperatura, permitiu verificar que possivelmente a variabilidade da temperatura e precipitação encontrada deve estar mais associado com eventos como El Niño do que com mudanças climáticas, entretanto, as tendências de aquecimento observadas podem estar relacionadas com o crescimento urbano. Para entender os impactos do crescimento urbano na modificação do microclima da RMM analisou-se índices de extremos climáticos de duas estações meteorológicas: uma situada no perímetro urbano e outra numa área rural da RMM. Verificou-se que as maiores mudanças térmicas ocorreram na área mais afastada da cidade, fato devido às mudanças de uso do solo na região periférica da RMM, enquanto que os índices relacionados a precipitação foram mais significativos na área urbana. Foram instalados termo-higrômetros em quatro pontos da RMM em áreas suburbanas e rurais para analisar os índices ICU, verificou-se que o índice sazonal de ICU foi maior (menor) nos meses de março a abril (outubro a dezembro), enquanto o índice horário obteve diferentes resultados de acordo com a época do ano: no mês chuvoso (seco) foi mais intenso no início da noite (do dia) com valor para a RMM atingiram valores máximos de 6°C (4,9°C). Na análise da Ilha de Calor Urbana em Superfície (ICUS) utilizaram-se cinco imagens de satélite e se verificou que em todas as imagens houve a comprovação de ICUS com núcleos nos centros da malhas urbanas das duas cidades da RMM e num distrito situado entre os dois centros urbanos analisados. Verificando os índices de conforto térmico gerados pela formação de ICU na RMM, comprovou-se que a região central da RMM apresenta os maiores valores e, que os índices de calor e de temperatura efetiva apresentaram boa relação com a percepção térmica da população de RMM, entrando o índice de conforto humano não se mostrou aplicabilidade na região em estudo.
The goal of the this Doctoral Thesis is to verify the occurrence of the Urban Heat Island (UHI) in the Macapá Metropolitan Area (RMM) Micro climate, which is placed in the Legal Amazon Northeast, due to the fact of the fast urbanization of the area. The development of the urban areas causes changes on the cover and use of the soil which could have a direct effect on the surface energy balance that may result in atmospheric modification in a local, or even regional,scale. In order to verify the RMM urban development, were used images from LANDSAT TM and OLI/TIRS of five different periods. Therefore, through the supervised classification MAXVER, it was possible to verify a expansion of the build-up area, the class of soil that covers the urban sheet, between 1986 and 2015. A climatic Analysis containing precipitation and temperature data showed that, probably, the variation of precipitation and temperature which appeared in the numbers presented are more likely to be associated with specific events, e.g. El Niño, than with the climatic changes. How ever, the growing heat trend observed during the research may be related to the urban development. In order to understand the impact of the development of the urban areas in the modification of the RMM micro climate, extreme climatic levels from two meteorologic bases were adopted: one of the those was placed within the urban perimeter; while the other was located in the RMM rural area. The data collected showed the biggest thermal changes took place further from the city, due to changes in the use of the soil in the isolated region of the RMM. About the levels related to precipitation, they were more significant in the urban areas. Term-hygrometers were installed in four different spots of the RMM, in suburban and rural areas, with the objective of analyzing the UHI levels. It was possible to verify that the season UHI levels were bigger (smaller) between March and April (October and December). The schedule levels showed different results along the year: during the rainy month (dry) it was more intense in the beginning of night (day) reaching maximum levels, in the RMM, of 6.0ºC (4.9ºC). For the analysis of the Urban Heat Island on Surface (SUHI) 5 satellite images were used and it was possible to verify in all of them the existence of ICUS with their cores located in the center of the urban sheets of the two cities that form the RMM and in a district placed between them. Trough the verification of the heat levels generated by the UHI formation in the RMM, it was possible to probe that the central area of the RMM presents the biggest values, and the IC and ITE levels are well connected to the RMM population's thermal perception. Considering the ICH it was evident the applicability of this Thesis in the area of the research.
Rodríguez-Laguna, María del Rocío. "Heat transfer fluids: From fundamental aspects of graphene nanofluids at room temperature to molten salts formulations for solar-thermal conversion." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/667803.
Повний текст джерелаHeat transfer fluids and nanofluids constitute an important element in the industry and their performance is key to the successful application in technologies that go from heat management and cooling to heat exchangers in thermal-solar energy and electricity generation. These industries demand heat transfer fluids with a wider liquid temperature range and better thermal performance than the conventional fluids. From low-temperature fluids to high-temperature molten salts, these fluids seem to benefit from the dispersion of solid nanoparticles, leading to nanofluids which frequently feature improved thermal conductivities and/or specific heats as compared with the bare fluids. However, there are some exceptions. Contradictory reports make it necessary to study these materials in greater depth than has been usual. Yet, the liquid nature of these materials poses a real challenge, both from the experimental point of view and from the conceptual framework. The work reported in this thesis has tackled two different challenges related to heat transfer fluids and nanofluids. In the first place, a careful and systematic study of thermal, morphological, rheological, stability, acoustic and vibrational properties of graphene-based nanofluids was carried out. We observed a huge increase of up to 48% in thermal conductivity and 18% in heat capacity of graphene-N,N-dimethylacetamide (DMAc) nanofluids. A significant enhancement was also observed in graphene-N,N-dimethylformamide (DMF) nanofluids of approximately 25% and 12% for thermal conductivity and heat capacity, respectively. The blue shift of several Raman bands (max. ~ 4 cm-1) with increasing graphene concentration in DMF and DMAc nanofluids suggested that graphene has the ability to affect solvent molecules at long-range, in terms of vibrational energy. In parallel, numerical simulations based on density functional theory (DFT) and molecular dynamics (MD) showed a parallel orientation of DMF towards graphene, favoring π–π stacking and contributing to the modification of the Raman spectra. Furthermore, a local order of DMF molecules around graphene was observed suggesting that both this special kind of interaction and the induced local order may contribute to the enhancement of the thermal properties of the fluid. Similar studies were also performed in graphene-N-methyl-2-pyrrolidinone nanofluids, however, no modification of the thermal conductivity or the Raman spectra was observed. All these observations together suggest that there is a correlation between the modification of the vibrational spectra and the increase in the thermal conductivity of the nanofluids. In light of these results, the mechanisms suggested in the literature to explain the enhancement of thermal conductivity in nanofluids were discussed and some of them were discarded. The second line of research focused on the development and characterization of novel molten salts formulations with low-melting temperature and high thermal stability. In this regard, two novel formulations of six components based on nitrates with a melting temperature of 60-75 °C and a thermal stability up to ~ 500 °C were synthesized. Moreover, the complexity of the samples led to establish a series of experimental methods which are proposed for the melting temperature detection of these materials as an alternative to conventional calorimetry. These methods are Raman spectroscopy, three-omega technique, and optical transmission.