Techn. Hochsch., Diss., 2004--Aachen.

Canada accounts for 15% of the world’s uranium production (World Nuclear Association). The Athabasca Basin in northern Saskatchewan Canada contains a number of high grade, uranium ore deposits which occur at, or immediately below, an unconformity between Archean and Paleoproterozoic metasediments and intrusive rocks and overlying Proterozoic sandstones. The uranium ores are largely composed of high concentrations of uraninite and Pitchblende with naturally occurring 238U/235U ratios. U- 236 (half-life of 23.42 Myr) will be produced when 235U absorbs a neutron and the nucleus does not fission. Because it is so long lived, a small amount 236U can be maintained at equilibrium levels in the natural uranium ores. One of the main questions of this research is whether or not these equilibrium levels reflect higher grades or larger amounts of uranium minerals as a result of elevated neutron fluxes from 238U and subsequent neutron absorption on 235U. As well, are there other elements within the system that will absorb these neutrons, thereby reducing that which will impinge on 235U. In this study, we have estimated the amount of 236U that is produced by calculating the neutron flux from uranium and evaluating the effects of spatially related elements such as B, Sm and Gd using their elemental neutron cross- sections and abundances. In this project we have calculated and simulated theoretically the production of 236U and then test the theoretical calculations using measurements of uranium isotopes by accelerator mass spectrometry (AMS). Once we understand the factors controlling the 236U concentration, we hypothesize that the relationship between 236U and 238U can be used as a geochemical vector within uranium exploration, with the equilibrium level possibly distinguishing between primary mineralization and remobilization and reprecipitation of this U within spatially associated secondary U mineralization.

Studien syftade till att undersöka om det fanns någon skillnad i akademisk motivation mellan män och kvinnor. En enkätundersökning gjordes vid Luleå Tekniska Universitet i form av det validerade mätinstrumentet akademiska motivationsskalan (AMS). Med hjälp av mätinstrumentet gick det att identifiera sju olika dimensionerna av akademisk motivation för respektive kön. Beräkningarna mättes och förklarades sedan med hjälp av SPSS. Av de 61 respondenter visade resultatet att den akademiska motivationen inte skiljde sig signifikant mellan män och kvinnor men att det fanns tendenser i resultatet som visade på skillnader mellan män och kvinnor i medelvärdet för de olika dimensionerna i akademisk motivation. Det visade sig att det skiljde sig mellan män och kvinnor i vilken typ av motivation som påverkade den totala motivationen.

Modern consumer electronic systems are mostly based on analog and digital circuits and are designed as analog/mixed-signal systems on chip (AMS-SoCs). the integration of analog and digital circuits on the same die makes the system cost effective. in AMS-SoCs, analog and mixed-signal portions have not traditionally received much attention due to their complexity. As the fabrication technology advances, the simulation times for AMS-SoC circuits become more complex and take significant amounts of time. the time allocated for the circuit design and optimization creates a need to reduce the simulation time. the time constraints placed on designers are imposed by the ever-shortening time to market and non-recurrent cost of the chip. This dissertation proposes the use of a novel method, called metamodeling, and intelligent optimization algorithms to reduce the design time. Metamodel-based ultra-fast design flows are proposed and investigated. Metamodel creation is a one time process and relies on fast sampling through accurate parasitic-aware simulations. One of the targets of this dissertation is to minimize the sample size while retaining the accuracy of the model. in order to achieve this goal, different statistical sampling techniques are explored and applied to various AMS-SoC circuits. Also, different metamodel functions are explored for their accuracy and application to AMS-SoCs. Several different optimization algorithms are compared for global optimization accuracy and convergence. Three different AMS circuits, ring oscillator, inductor-capacitor voltage-controlled oscillator (LC-VCO) and phase locked loop (PLL) that are present in many AMS-SoC are used in this study for design flow application. Metamodels created in this dissertation provide accuracy with an error of less than 2% from the physical layout simulations. After optimal sampling investigation, metamodel functions and optimization algorithms are ranked in terms of speed and accuracy. Experimental results show that the proposed design flow provides roughly 5,000x speedup over conventional design flows. Thus, this dissertation greatly advances the state-of-the-art in mixed-signal design and will assist towards making consumer electronics cheaper and affordable.

The objective of the dissertation thesis was to evaluate the effects of two different types of milking systems (CMS - conventional milking system vs. AMS - an automatic milking system) on average daily milk yield, on frequency of attending robots, on pre-milking teat preparation procedures and stimulation and milking time, on the teats traumatization of Holstein cows. The experiments were performed in two locations: Žabčice School Farm of Mendel University in Brno and ZEMAX, a. s. in Šitbořice. Data was collected for a period 1st January 2014 to 15th December 2015. Higher average milk yield per day and lower milk yield per milking on the other hand on the farm with AMS were caused by a higher frequency of milking. Cows on farm with CMS were milked twice a day. On the farm with AMS dairy cows were milked in accordance with their own needs. Milking frequency in the AMS was in 2014 2.47, in 2015 2.88 per day. Heat stress has negative impacts on milk production. Effect of heat stress showed more markedly in 2015, which is probably related to the fact that the value of THI greater than 80 lasted longer. The length of pre-milking teat preparation procedures and stimulation various neighborhoods was found in AMS in 2014 from 0:13 min. to 0:16 min., in 2015 from 0:14 min. to 0:19 min. On farm with CMS time not be registered. The length of milking time with CMS in both years was 5:02 min. In AMS was in 2014 from 3:03 minutes to 3:53 min., in 2015 from 3:05 min. to 4:45 minutes. In process of milking machine teat traumatization were smaller when using AMS.

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