National Repository of Grey Literature 9 records found  Search took 0.00 seconds. 
Use of thermally conductive non-metallic materials for cooling systems in automotive lighting technology
Zachar, Martin ; Makki, Zbyněk (referee) ; Vitkovič, Pavol (referee) ; Kotrbáček, Petr (advisor)
This thesis deals with the use of non-metallic highly thermally conductive materials, more concrete-ly special plastic materials, enriched with highly thermally conductive additives, for the purpose of passive cooling of a given heat source. The thesis compares the effectivity of these heat sinks with the classically used materials, specifically aluminium. The thesis is divided into two main sections, theoretical and practical. The theoretical part deals with a constantly growing need of LED (Light Emitting Diode) chips cooling in automotive head-lamps, where the new materials could be put into effect, analyses possible replacement of classic aluminium heat sinks with different materials with a significantly lower thermal conductivity and introduces problems of such materials. The practical part applies the problematic described in the theoretical one on the actually produced heat sinks, which are compared among themselves, with regard to their method of production, as well as with aluminium counterpart in different conditions. Furthermore, the problematic of de-signing a heat sink made from material which is characteristic for its highly anisotropic thermal con-ductivity is dealt with. The end of the thesis shows the importance of heat dissipation via radiation, which can have a great significance in case of plastic heat sinks and in a specific applications.
Study of the thermal and light conditions in the automobile headlamp with built-in light source of the new generation
Zachar, Martin ; Černý,, Pavel (referee) ; Černý, Pavel (referee) ; Raudenský, Miroslav (advisor)
This thesis deals with automotive headlamps, focusing on layout of temparature field and its influence on thermal stress of used materials, describes their history, kinds and ongoing research. Thesis shortly describes light and its characteristics, heat and heat transfer and means of temperature measurement. Main part of the tesis is dedicated to measuring front headlamp serving as a fog light, concretely measuring temperature field and illuminance depending of ambient temperature. Thesis contains everything from the first preparations, creation of measuring circuit, programming of measuring to processing acquired data. Thesis also compares cooler used for cooling luxmeter sensor, the comparision is between measured values and created simulation.
Thermal measurement
Zachar, Martin ; Lisý, Martin (referee) ; Kracík, Petr (advisor)
This thesis deals with theory of thermal measurement with both physical as well as technical side. Thesis describes basic methodics of thermal measurment and further compares few different thermographic cameras at the current market. Main part of the thesis is focusing on a script, that has been created in program Matlab, serving for analysis of a series of thermographic pictures capturing verticaly placed pipes, following by registration of founded temperatures to Excel and drawing of diagrams of the change of average temperature along pipe and histograms of temperatures of given pictures.
Analysis of transfer mispricing of commodity exports in African countries
Zachar, Martin ; Janský, Petr (advisor) ; Kracík, Jiří (referee)
Governments around the world are burdened by what is estimated to be a $160 billion annual tax loss stemming from transfer mispricing. Developing countries may be even more susceptible to this phenomenon due to their lax reporting and regulatory standards. However, research done to date on transfer mispricing with regards to developing countries is very limited. This paper investigates commodity transactions between selected African countries and the world for 2008-2009, looking for pricing anomalies in both absolute terms and in relation to global mispricing averages. The data was examined using linear regression models, volume-based analysis and case study analyses. While the former two did not find convincing evidence of substantial price distortions, the latter uncovered several anomalies that may point to mispricing. These results point to the fact that transfer mispricing occurring in developing countries is in line with that of the rest of the world.
Use of thermally conductive non-metallic materials for cooling systems in automotive lighting technology
Zachar, Martin ; Makki, Zbyněk (referee) ; Vitkovič, Pavol (referee) ; Kotrbáček, Petr (advisor)
This thesis deals with the use of non-metallic highly thermally conductive materials, more concrete-ly special plastic materials, enriched with highly thermally conductive additives, for the purpose of passive cooling of a given heat source. The thesis compares the effectivity of these heat sinks with the classically used materials, specifically aluminium. The thesis is divided into two main sections, theoretical and practical. The theoretical part deals with a constantly growing need of LED (Light Emitting Diode) chips cooling in automotive head-lamps, where the new materials could be put into effect, analyses possible replacement of classic aluminium heat sinks with different materials with a significantly lower thermal conductivity and introduces problems of such materials. The practical part applies the problematic described in the theoretical one on the actually produced heat sinks, which are compared among themselves, with regard to their method of production, as well as with aluminium counterpart in different conditions. Furthermore, the problematic of de-signing a heat sink made from material which is characteristic for its highly anisotropic thermal con-ductivity is dealt with. The end of the thesis shows the importance of heat dissipation via radiation, which can have a great significance in case of plastic heat sinks and in a specific applications.
Cross-border effects of sovereign rating changes on bond yields before and during the Eurozone crisis
Zachar, Martin ; Schneider, Ondřej (advisor) ; Geršl, Adam (referee)
This paper looks into the contagion dynamics of sovereign credit rating changes with regards to bond yields in the period before and during the sovereign debt crisis in Europe. Our sample included European Union member countries, as well as a Eurozone subsample and a subsample excluding highly indebted countries. Events and outlooks from all three major rating agencies were considered. Our findings for the pre-crisis period are consistent with existing research, indicating an increase in borrowing costs by approximately five basis points in the case of a one-notch negative event, and insignificant effects in the case of positive events. During the crisis period, we observed a reversal of this effect, associating negative ratings with lower spreads on the entire sample. However, the effect was no longer significant when highly indebted countries were excluded from the sample, indicating that this effect may be tied to overly negative expectations. Lastly, we investigated the persistence of results, with only full-sample crisis period data displaying persistent effects. JEL Classification F01, F34, F42 Keywords credit rating, sovereign debt, default, debt crisis, European debt, sustainability Author's e-mail martin1703@gmail.com Supervisor's e-mail schneider.ondrej@gmail.com
Analysis of transfer mispricing of commodity exports in African countries
Zachar, Martin ; Janský, Petr (advisor) ; Kracík, Jiří (referee)
Governments around the world are burdened by what is estimated to be a $160 billion annual tax loss stemming from transfer mispricing. Developing countries may be even more susceptible to this phenomenon due to their lax reporting and regulatory standards. However, research done to date on transfer mispricing with regards to developing countries is very limited. This paper investigates commodity transactions between selected African countries and the world for 2008-2009, looking for pricing anomalies in both absolute terms and in relation to global mispricing averages. The data was examined using linear regression models, volume-based analysis and case study analyses. While the former two did not find convincing evidence of substantial price distortions, the latter uncovered several anomalies that may point to mispricing. These results point to the fact that transfer mispricing occurring in developing countries is in line with that of the rest of the world.
Study of the thermal and light conditions in the automobile headlamp with built-in light source of the new generation
Zachar, Martin ; Černý,, Pavel (referee) ; Černý, Pavel (referee) ; Raudenský, Miroslav (advisor)
This thesis deals with automotive headlamps, focusing on layout of temparature field and its influence on thermal stress of used materials, describes their history, kinds and ongoing research. Thesis shortly describes light and its characteristics, heat and heat transfer and means of temperature measurement. Main part of the tesis is dedicated to measuring front headlamp serving as a fog light, concretely measuring temperature field and illuminance depending of ambient temperature. Thesis contains everything from the first preparations, creation of measuring circuit, programming of measuring to processing acquired data. Thesis also compares cooler used for cooling luxmeter sensor, the comparision is between measured values and created simulation.
Thermal measurement
Zachar, Martin ; Lisý, Martin (referee) ; Kracík, Petr (advisor)
This thesis deals with theory of thermal measurement with both physical as well as technical side. Thesis describes basic methodics of thermal measurment and further compares few different thermographic cameras at the current market. Main part of the thesis is focusing on a script, that has been created in program Matlab, serving for analysis of a series of thermographic pictures capturing verticaly placed pipes, following by registration of founded temperatures to Excel and drawing of diagrams of the change of average temperature along pipe and histograms of temperatures of given pictures.

See also: similar author names
1 Zachar, Marián
2 Zachar, Michal
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