• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 155
  • 4
  • Tagged with
  • 159
  • 122
  • 67
  • 49
  • 25
  • 23
  • 18
  • 17
  • 17
  • 17
  • 16
  • 15
  • 14
  • 13
  • 13
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Kardiovaskulární DRIFT / Cardiovascular DRIFT

Kypúsová, Monika January 2013 (has links)
INTRODUCTION: Cardiovascular drift is a phenomenon, which appears after 10 - 20 minutes of prolonged moderate - intensity exercise (50 - 75% VO2max). CVD appears in a neutral or hot environment. It is characterized by a decline in stroke volume and systemic mean arterial pressures and a parallel increase in heart rate. Cardiac output is maintained nearly constant. The theory of CVD shows increase of core temperature and sympathetic nervous system as cause of increase of heart rate. GOALS: The goal of this thesis was find out the change of heart rate depending on time. Then we found out changes of oral, tympanic, axillary, vaginal and superficial skin temperature. We found out correlation between vaginal temperature and heart rate and then between skin temperature and vaginal temperature. METHODS: Blood pressure, heart rate, oral, tympanic, axillary, vaginal and superficial skin temperature were measured during 60 minutes of cycling (intensity 55% VO2max; 1,99 ± 0,14 W/kg). It was measured at 13 women (25,5 ± 1,3 years; 69,1 ± 7,7 kg). RESULTS and CONCLUSION: There was statistically significant increase of heart rate compared to value from 10. minute. during. There was increase of tympanic temperature compared to value from 10. minute only at the end of exercise. There was significant increase of vaginal and...
72

Změny délek odobí s charakteristickými teplotami vzduchu / Changes of length of periods with characteristic temperatures

Černochová, Eva January 2006 (has links)
Title: Changes of lengths of periods with characteristic air temperatures Author: Eva Černochová Department: Department of Meteorology and Environment Protection Supervisor: doc. RNDr. Jaroslava Kalvová, CSc. Supervisor's e-mail address: jaroslava.kalvova@mff.cuni.cz Abstract: Lengths of periods with characteristic air temperatures were derived using two different methods (linear interpolation, robust locally weighted regression) for 10 stations in the Czech Republic and for output data of regional climate models HIRHAM and RCAO in 4 grid points. Averages for a forty-year period (1961-2000) and for a thirty-year period (1961-1990) were computed as well as averages for every decade. Considerable attention was also paid to the analysis of methods used in the research. Most stations showed lengthening of growing season and summer during the twentieth century. Decennary average length of growing season and summer shortened in the years 1971-1980. The comparison of output data of regional climate models HIRHAM and RCAO and measured station data showed that the thirty-year average lengths of growing season and summer estimated by the two models were reasonably accurate approximately half of all cases. The models' estimates were not accurate at all concerning decennary averages. Keywords: robust locally...
73

Extrémní denní amplitudy teploty vzduchu v ČR v letech 1961-2007 / Extreme daily temperature range in Czechia in 1961-2007

Maňhal, Daniel January 2018 (has links)
This thesis deals with the extreme daily temperature range (DTR) during the period 1961-2007 for the extended winter season, based on an analysis of the daily series from 49 climatological stations in the Czech Republic. The aim of the research was to find the frequency of the extreme DTR in the individual months and describe the effect of the sunshine, the snow cover and the altitude on the magnitude of the extreme DTR. Moreover, the work focused on the identification of typical synoptic situations, during the days with extreme DTR. During the study period, 1746 days with extreme DTR were detected at least at one climatological station. The extreme DTR occurred most often in March in the anticyclonic situations. During the days with strong wind, the eastern flow direction prevailed anticyclonic situations whereas the western direction prevailed cyclonic situations. The highest values of the extreme DTR generally occurred in the lowlands since the magnitude of extreme DTR decreased with increasing altitude. In general, the values of extreme DTR were reduced (by 0,2 řC on average) during the days with snow cover. Cloud cover had a similar effect, the mean difference of extreme DTR between cloudy days (defined as days with sunshine duration less than 1 h/day) and sunny days was 0,5 řC. The acquired...
74

Diagnostika vlastností betonů vystavených působení vysokých teplot / Diagnostic properties of concrete exposed to high temperatures

Hudský, Petr January 2014 (has links)
This master’s thesis studies the problems of high temperatures on cement concretes, their following diagnostics from pre-treatment to rehabilitation, the emphasis was on the use of high-speed water jet. In the experimental part of the design of a concrete composition with basalt aggregate. Were reviewed the physico-mechanical properties after thermal loading. The influence of pressure water jet on the thermal load on concrete, pull-off test, the volume of the removed concrete with a strength evaluation and comparison.
75

Měření povrchové teploty pomocí infračervené kamery / Surface temperature measurements by IR camera

FUKA, Miloš January 2014 (has links)
The master's thesis is devoted to the history and performance of non-contact temperature measurement, characterization of infrared cameras and infrared thermometers. Temperature is one of the most important physical quantities. Using an infrared camera we obtain information about the surface temperature in all picture. In the master's thesis is included the measurement and capturing the fatal defects on the punched billet, finding out the quality of temperature field and the quality of the overlapping work rolls. During the measurements were used infrared cameras TIM200, TIM400 from the company Micro-Epsilon and infrared cameras SC325, SC660 from the company Flir.
76

Využitelnost měření teploty povrchu těla zvířat / Usability of measurement of animal surface temper

SOBÍŠKOVÁ, Kateřina January 2018 (has links)
The aim of the dissertation was to present technical possibilities of scanning and measuring the body temperature and provide a method for a non-contact measurement of body surface temperatureof animals including data transfer to higher-level software. Partial results can be part of an automated herd management system to ensure better animal welfare monitoring. One method of contactless measuring the surface temperature was taking the surface temperature by using an infrared camera. This tool was used to scan surface temperatures in the area of the body core, the udder region and the eye area. Thermograms, sometimes referred to as thermal imaging, were obtained from the individual regions. In total, there were 34 measurements in 2013 and 17 measurements in 2014.Cows from Petrovice centre were included in the experiment. Three different groups of dairy cows were evaluated in two different stables. In the first group there were cows which gave birth 2 days to 2 months before. The second group consisted of dairy cows which calved 4 to 5 months before. The third group included dairy cows which gave birth 7 to 8 months before. Based on the results of measurements of selected surface temperatures, it was found that the surface core temperature and the udder surface temperature correlated most. However, when measuring surface temperatures, the degree of pollution, coating, and oscillation of the animal play an important role. Moreover, technological parameters of the device are also important, specially its setting and the emissivity of the surface. This experiment ran from August to September 2016 in a purpose-built schoolhouse facility in an experimental stable accredited for experimental purposes. The experiment included two clinically healthy cows of the Holstein breed, which had been implanted with the identification chip and tested for its functionality. This chip was implanted to both animals in the tail root region and was fitted with a biological function sensor that followed the body temperature of the animal. The device was adapted to send animal identification information and animal body temperature information by means of a wireless connection to the chip reader. Based on the findings, one or more systems, preferably non-contact body temperature scanning, could be designed and tested. Regarding the use of other surface temperature scanning possibilities, this is still in the process of development and implementation. The disadvantage of the above described device is that it fails to recognize the cause of the elevated temperature and requires intervention by the attendant without the intervention being necessary. The attending keeper may not recognize acute cases and may cause permanent damage to the health or even death of the animal. The task of the device is to find a method of unattended animal temperature measurement connected with its electronic identification that would recognize sick or infected animals from overheated ones. This device would categorize the animals and take precautions to preserve their health. The invention should be applicable to a wide variety of animals.
77

Vliv teploty vzduchu na FDM 3D tisk / Effect of air temperature on FDM 3D printing

Hrdlička, Martin January 2017 (has links)
The thesis deals with 3D printing by the FDM and ambient temperature on print quality. The thesis describes the principle of printing by the FDM method and the occurrence of errors caused by the influence of ambient temperature. The aim of the thesis is to design a heated chamber for RepRap Prusa i3 printer, its construction and subsequent testing of ambient temperature influence on print quality. To test the occurrence of the described errors, specific tests and materials are selected in the work. The result of this work is the recommended ambient temperature in the heated chamber for improved FDM printing.
78

Vliv integrálu teploty a času pájení na kvalitu pájeného spoje / Solder Joint Quality based on Heating Factor

Kučírek, Martin January 2017 (has links)
Master’s thesis in the theoretical part analyses the heating factor (Q), which has significant share on quality of a solder joint. The practical part describes the design and production of test PCB and setting temperature profiles, SMD resistors soldering by using BiSn solder paste. Shear tests of SMD solder joints were realised and evaluated including isothermal ageing samples. At the end of master’s thesis solder joints visual aspects and defects were evaluated, measurement thickness of intermetallic compound by not only optical microscope but also SEM, discussion about results and Q was evaluated.
79

Podélné indexové struktury v optických vláknech / Longitudinal index structures in optical fibers

Polreich, Štěpán January 2018 (has links)
This thesis describes basic concepts, principles and properties of optical fibers. Considerable part is devoted to fiber gratings that are created by a change in the refractive index in the optical fiber core. In this work is described description, principle, method od production and distribution of gratings on Bragg gratings, gratings with long period and chirped gratings. In this thesis are also presented different types of lasers and their advantages over other lasers. A large part deals with the description of the femtosecond laser, with which the structures will be later made into the material. In addition, the laser modes are differentiated, this is a mode of micro-machining and modification or a change in refractive index of the material. The last part deals with change the refractive index in planar technology, the creation of a groove for fastening the fiber and attempts to write the gratings into the optical fiber. Created fiber sensor are tested for temperature and tensile changes. Finally, the practical use of sensors made by femtosecond laser and the advantages over UV laser and phase mask techniques are presented.
80

Numerická metoda pro měření elektronové teploty sluneční koróny / Numerical method of solar corona electron temperature measurement

Dospiva, Jindřich January 2018 (has links)
This thesis is about the calculation of a spectral radiance for the K-corona, the continuius spectral part which arise from the Thomson scattering of a solar radiance of free electrons in the corona. Also the Doppler effect is described as it smooth down a solar spectrum (with many absorption lines) to a smoother spectrum of the K-corona. It’s also possible to determine the temperature of free electrons from spectral shape, from which proceeds the method of temperature measurement. NASA intends to use this method on the probe ONSET. Also, temperature definition and its significance are discussed.

Page generated in 0.0307 seconds