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Selective Soldering
Stoklásek, Lukáš ; Petr, Martinec (referee) ; Starý, Jiří (advisor)
This diploma thesis introduces the problematics of selective soldering. The theoretical part deals with description of soldering process and its possibilitites, use of this processes for selective soldering and the control of production. The practical part describes the methodics of measuring the amount and uniformity of flux applied on printed circuit boards, effects and stability of preheaters and dwell time if PCB in the soldering wave. The next part deals with the production test for the certain product, cleanness of the single processes, x-ray diagnostics and cross section of the boards. In the end is economic evaluation of the processes. The main object of this thesis is to suggest the optimal production process for the product.
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Reducing of energy and ecological demands of brickmaking production
Blažek, Tomáš ; Skotal, Zbyněk (referee) ; Sokolář, Radomír (advisor)
This bachelor thesis focuses on the possibility of lowering the required firing tem-perature of brick body by adding different fluxes that promote the formation of the crystalline phase. The thesis also examines the possibility of reducing the amount of fuel required and the associated decrease in carbon dioxide production. Finally, the thesis presents the possibilities of using alternative lightweighting agents as a substitute for the currently used standard wood sawdust.
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CARBON AND NITROGEN POOLS AND FLUXES OF TWO FOREST ECOSYSTEMS IN THE ORE MOUNTAINS
Růžek, Michal ; Oulehle, Filip (advisor) ; Tahovská, Karolina (referee)
CARBON AND NITROGEN POOLS AND FLUXES OF TWO FOREST ECOSYSTEMS IN THE ORE MOUNTAINS With increasing atmospheric CO2 concentrations, forest ecosystems are considered for their sequestration ability. However, there are differences between coniferous and deciduous tree species in their impact on the carbon (C) and nitrogen (N) fluxes within forest ecosystems, which influence soil carbon and nitrogen pools. In natural beech and monoculture spruce stands on research sites of Czech Geological Survey in the Ore Mountains, C and N fluxes and pools were investigated. There were investigated ecosystem inputs (C, N, in throughfall, litterfall) as well as outputs (soil respiration, concentrations of C, N in seepage water discharge). Further, C and N pools of living biomass and soils were determined. Throughfall DOC was significantly higher in the spruce stand, on the other hand litterfall C flux showed the opposite relationship. At output, DOC, DON and NH4 + discharge fluxes from O horizon were significantly higher in the spruce stand whereas in the beech stand higher NO3 - flux from mineral soil was recorded. Soil respiration was quite similar in the both stands, however different parts of original sources of respiration among tree species were different. Beech stand has larger pools of carbon and nitrogen in...
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CARBON AND NITROGEN POOLS AND FLUXES OF TWO FOREST ECOSYSTEMS IN THE ORE MOUNTAINS
Růžek, Michal
CARBON AND NITROGEN POOLS AND FLUXES OF TWO FOREST ECOSYSTEMS IN THE ORE MOUNTAINS With increasing atmospheric CO2 concentrations, forest ecosystems are considered for their sequestration ability. However, there are differences between coniferous and deciduous tree species in their impact on the carbon (C) and nitrogen (N) fluxes within forest ecosystems, which influence soil carbon and nitrogen pools. In natural beech and monoculture spruce stands on research sites of Czech Geological Survey in the Ore Mountains, C and N fluxes and pools were investigated. There were investigated ecosystem inputs (C, N, in throughfall, litterfall) as well as outputs (soil respiration, concentrations of C, N in seepage water discharge). Further, C and N pools of living biomass and soils were determined. Throughfall DOC was significantly higher in the spruce stand, on the other hand litterfall C flux showed the opposite relationship. At output, DOC, DON and NH4 + discharge fluxes from O horizon were significantly higher in the spruce stand whereas in the beech stand higher NO3 - flux from mineral soil was recorded. Soil respiration was quite similar in the both stands, however different parts of original sources of respiration among tree species were different. Beech stand has larger pools of carbon and nitrogen in...
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COMPARISON OF ACTUAL EVAPOTRANSPIRATION FROM ALEXI AND SOILCLIM MODELS
Jurečka, František ; Hlavinka, Petr ; Lukas, Vojtěch ; Trnka, Miroslav ; Anderson, M. ; Hain, C. ; Balek, Jan ; Bláhová, Monika ; Žalud, Zdeněk
Actual evapotranspiration (ETa) determined by the Atmosphere-land Exchange Inverse (ALEXI) model and water balance model SoilClim was compared for selected districts of the Czech Republic. The ALEXI model uses the land surface temperature (LST) from remote sensing and provides information on ETa and subsequently the surface moisture status. The SoilClim is a dynamic model of watcr content in soil and represents a model based on water balance approach. The current version of the model is able to estimate the value of ETa, as well as soil moisture content in two layers of the soil profile. Investigated period of ETa comparison were years 2014 and 2015. Especially the year 2015 had a special relevance due to the significant summer drought that occurred in CR. Model performance was compared for the period when changes in vegetation are most significant from April to August. Week sums of ETa from both models were compared at the district level for Vysodina, JihomorayskY and Olomouck, regions. The ETa values were generally higher from ALEXI as compared to SoilClim. ALEXI values were in some cases even two or three time higher. Moreover, the seasonal dynamics showed sometimes opposite trends. As this is a pilot testing of ALEXI based ETa in the conditions of Central Europe and show large differences as compared to well established methods, more detailed testing is required prior drawing any general conclusions.
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Selective Soldering
Stoklásek, Lukáš ; Petr, Martinec (referee) ; Starý, Jiří (advisor)
This diploma thesis introduces the problematics of selective soldering. The theoretical part deals with description of soldering process and its possibilitites, use of this processes for selective soldering and the control of production. The practical part describes the methodics of measuring the amount and uniformity of flux applied on printed circuit boards, effects and stability of preheaters and dwell time if PCB in the soldering wave. The next part deals with the production test for the certain product, cleanness of the single processes, x-ray diagnostics and cross section of the boards. In the end is economic evaluation of the processes. The main object of this thesis is to suggest the optimal production process for the product.
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CARBON AND NITROGEN POOLS AND FLUXES OF TWO FOREST ECOSYSTEMS IN THE ORE MOUNTAINS
Růžek, Michal
CARBON AND NITROGEN POOLS AND FLUXES OF TWO FOREST ECOSYSTEMS IN THE ORE MOUNTAINS With increasing atmospheric CO2 concentrations, forest ecosystems are considered for their sequestration ability. However, there are differences between coniferous and deciduous tree species in their impact on the carbon (C) and nitrogen (N) fluxes within forest ecosystems, which influence soil carbon and nitrogen pools. In natural beech and monoculture spruce stands on research sites of Czech Geological Survey in the Ore Mountains, C and N fluxes and pools were investigated. There were investigated ecosystem inputs (C, N, in throughfall, litterfall) as well as outputs (soil respiration, concentrations of C, N in seepage water discharge). Further, C and N pools of living biomass and soils were determined. Throughfall DOC was significantly higher in the spruce stand, on the other hand litterfall C flux showed the opposite relationship. At output, DOC, DON and NH4 + discharge fluxes from O horizon were significantly higher in the spruce stand whereas in the beech stand higher NO3 - flux from mineral soil was recorded. Soil respiration was quite similar in the both stands, however different parts of original sources of respiration among tree species were different. Beech stand has larger pools of carbon and nitrogen in...
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Flux Fluxes in the Amphibolite Basin On the Green at the Marianske Lazne Water Works
Krám, Pavel ; Veselovský, F. ; Čuřík, Jan ; Myška, Oldřich
The paper is about hydrology and hydrochemistry of the Na Zelenem catchment forested by spruce stands which growso n substrate formed by Cambisol on amphibolite. This catchment is characterized by fairly favorable hydrochemical conditions for terrestrial and aquatic biota. The catchment is able to effectivetely neutralize incoming acidic atmopheric deposition mainly due to chemical weathering reactions involving divalent base cations, calcium and magnesium. Mean average precipitation to the Na Zelenem catchment was 790 mm/yr based od 5 year studied period and mean surface runoff was 193 mm/yr in the last two years. Runoff was between 24 and 27% of annual precipitation input to the catchment in the last two years. The catchment accumulated less than 20% of total nitrogen input in bulk precipitation. About 36% of nitrogen left the catchment via surface runoff. About half of the nitrogen output was in the form of nitrate and about half in the form of dissolved organic nitrogen.
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CARBON AND NITROGEN POOLS AND FLUXES OF TWO FOREST ECOSYSTEMS IN THE ORE MOUNTAINS
Růžek, Michal ; Oulehle, Filip (advisor) ; Tahovská, Karolina (referee)
CARBON AND NITROGEN POOLS AND FLUXES OF TWO FOREST ECOSYSTEMS IN THE ORE MOUNTAINS With increasing atmospheric CO2 concentrations, forest ecosystems are considered for their sequestration ability. However, there are differences between coniferous and deciduous tree species in their impact on the carbon (C) and nitrogen (N) fluxes within forest ecosystems, which influence soil carbon and nitrogen pools. In natural beech and monoculture spruce stands on research sites of Czech Geological Survey in the Ore Mountains, C and N fluxes and pools were investigated. There were investigated ecosystem inputs (C, N, in throughfall, litterfall) as well as outputs (soil respiration, concentrations of C, N in seepage water discharge). Further, C and N pools of living biomass and soils were determined. Throughfall DOC was significantly higher in the spruce stand, on the other hand litterfall C flux showed the opposite relationship. At output, DOC, DON and NH4 + discharge fluxes from O horizon were significantly higher in the spruce stand whereas in the beech stand higher NO3 - flux from mineral soil was recorded. Soil respiration was quite similar in the both stands, however different parts of original sources of respiration among tree species were different. Beech stand has larger pools of carbon and nitrogen in...
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