National Repository of Grey Literature 16 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Temperature characteristics of surface using remote sensing methods
Hofrajtr, Martin ; Štych, Přemysl (advisor) ; Brom, Jakub (referee)
Temperature characteristics of surface using remote sensing methods Abstract The aim of this thesis is to design a methodology for refining the land surface temperature values obtained from Landsat 8 satellite data in areas with diverse land cover. The research section describes factors influencing the radiation of the Earth's surface. Also mentioned are current methods used for processing infrared thermal data and calculate land surface temperature. The practical part describes satellite and airborne data used in the analytical and verification process. All parts of the applied method leading to the subpixel value of the land surface temperature are described in detail in the method part. The results are then compared with airborne verification data with better spatial resolution and with currently used methods. Finally, the pros and cons of this method and its possible improvement in the future are mentioned. Key words: land surface temperature, land surface emissivity, satellite data, Landsat 8, airborne data, subpixel method, Czech Republic
CFD simulation of air flow inside a car cabin
Kučera, Cyril ; Elcner, Jakub (referee) ; Pokorný, Jan (advisor)
The diploma thesis deals with CFD simulating the air flow inside the car using the numerical calculation program Star-CCM+. The aim of the thesis was to prepare 3D geometry, resp. realistic model of the real car, preparing boundary conditions including material properties, simulating the steady state of the environment and evaluating the speed and temperature of the car cabin. The paper presents the results of the temperature distribution and air velocities in the cabin during the winter, spring and summer conditions in HVAC on and HVAC off modes. The monitored air temperatures and surface temperatures of the car parts are compared with the measured data. The average difference between simulation and measurement was at air temperatures of 2.3 °C and surface temperatures of 3.4 °C.
Observing of the skeletal muscle shape changes depending on human body surface temperature
Frýdová, Aneta ; Stupka, Martin (advisor) ; Otáhal, Martin (referee)
Title: Observing of the skeletal muscle shape changes depending on human body surface temperature Objectives: The aim of this work is to observe the cross-section changes of the m. rectus femoris depending on human body surface temperature changes. The cross section of the muscle was characterized by two dimensions: VDDM (ventrodorsal dimension of muscle) and LMDM (lateromedial dimension of muscle). The body temperature was affected by local positive and negative thermotherapy methods. Methods: The first part of the experiment focused on the selection of appropriate local positive and negative thermotherapy forms. Four of them were selected (two positive thermotherapy methods - Peat thermotherapy bags and infrared heater InfraPhil HP3616 and two negative thermotherapy methods - gel bag Cryoflex and Cryogen 3 device) for the main research. Twelve subjects participated on the main experiment. Selected local positive thermotherapy methods were applied on the centre of the subject's thighs, subsequently selected negative thermotherapy methods were applied. The body surface temperature was measured immediately before application, after 30 minutes of positive thermotherapy and after subsequent negative thermotherapy application. Ultrasound images of m. rectus femoris were taken at same time. VDDM and...
Evolution of terrestrial exoplanets
Káňová, Michaela ; Běhounková, Marie (advisor) ; Čadek, Ondřej (referee)
Observations of terrestrial exoplanets provide a unique statistical set that may improve our knowl- edge of their formation, structure as well as internal and orbital evolution. Close-in extrasolar planets are subjected to strong stellar tides, resulting in an extensive dissipation of mechanical energy (tidal heating), long-term orbital evolution and evolution of the rotational frequency. For the exoplanets on eccentric orbits, the traditional tidal theories predict locking into pseudo-synchronous spin states, for which the rotational frequency is slightly higher than the orbital frequency. Such predictions are, how- ever, in contradiction with the observations of moons in the Solar system, and are a consequence of simplified rheological assumptions. Here, we focus on a numerical approach to the tidal evolution of planetary orbit and rotation in a single-planet system, assuming a Maxwell viscoelastic rheology. We find equillibrium spin states, including the spin-orbit resonances, and discuss their connection with the minima of tidal heating. Locking into a spin-orbit resonance results in an irregular insolation pattern and an unequal surface temperature distribution, affecting the internal dynamics of the planet. The second part of the thesis therefore deals with the evaluation of the surface temperature and...
Comparison of various approaches to evaluation of tree energetic balance
Tomková, Alžběta ; Pokorný, Jan (advisor) ; Lhotáková, Zuzana (referee)
The thesis deals with the tree energetic balance closely related to the phenomenon of plant transpiration. Living systems have a unique ability to equilibrate gradients in the nature. Storing energy of the incoming solar radiation into a latent heat of water evaporation is an example of such tree feature. It dissipates energy and simultaneously recycles nutrients and water in the ecosystem. There are few possible ways of energy balance detection shown in this work. The thermal imagining can be used as a method for an indirect indication of transpiration - transpiring plants have lower leaf surface temperature. An alternative method for determining the rate of transpiration is a direct measurement of transpiration on leaves or transpiration flow in a tree trunk. However, extrapolation of the above mentioned methods to entire stands can encounter some difficulties. The first part of the thesis presents a description of a physical background of energetic processes and the ways in which plants operate with water, the biotic pump theory is being discussed. The practical part begins with experiments on single leaves. These experiments are carried out to test the usability of the methods for the following experiments, which are performed on the entire living trees. They are focused on the relationship of the...
Insolation pattern and surface temperature on extrasolar planets
Káňová, Michaela ; Běhounková, Marie (advisor) ; Čadek, Ondřej (referee)
We study evolution and distribution of surface and near-surface temperature on tidally locked extrasolar terrestrial planets without atmosphere. In order to determine the temperature, insolation patterns depending on eccentricity, obliquity and spin-orbit resonance are computed and thermal diffusion equation is solved in a spherical shell. We discuss the dependence of temperature distribution on physical and geometrical parameters including orbit eccentricity, obliquity of rotational axis, type of spin-orbital resonance, thermal inertia and irradiance incident on the planetary surface (the extra- solar constant). The mean annual temperature is driven especially by the extrasolar constant and may rise up to thousand of kelvins in the most irradiated regions. Effect of eccentricity, obliquity and thermal inertia, in some cases, is on the scale of hundreds of kelvins.
Thermal properties of automotive light sources - Halogen sources
Hlubinka, David ; Hájek, Vítězslav (referee) ; Janda, Marcel (advisor)
The aim of master´s thesis is to get acquainted with the design and materials used in selected automotive light source – tungsten halogen lamp. Further, the thesis focused on the theory and appropriate selection of the thermal measurement method on a real sample. Subsequently, a model of the light source and its simulation in the ANSYS – Maxwell 3D and Mechanical programs are created. Finally, the results of the thermal simulation and the non-contact measurement of the tungsten halogen lamp are evaluated
Ranque - Hilsh vortex tube
Bábor, Lukáš ; Brázdil, Marian (referee) ; Šnajdárek, Ladislav (advisor)
Ranque-Hilsh vortex tube is a device that converts high pressure gas flow into two low pressure flows with higher and lower temperature, than a temperature of the inlet flow. Technically, it is a device of very simple construction, which is characterised by low initial costs, high endurance, durability and low maintenance. Its main disadvantage is low coefficient of performance, compared to conventional heat pumps at room temperature. In the first section of this paper, examples of applications where utilization of Ranque-Hilsh vortex tube is advantageous are given. Afterwards, several theoretical concepts of refrigeration cycles utilizing vortex tube to lower energy consumption are described. The final section of this thesis introduces new geometry of inlet nozzles for improving coefficient of performance of vortex tube. This geometry is then compared to straight tangential nozzles of circular cross-section. During the measurements, surface temperature of the vortex tube with respect to its length is monitored.

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