154 research outputs found

    Development of Novel Nano - Single Si Phase Cast Hypereutectic Al-Si Alloys

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    The research presented in this PhD dissertation renders a novel nano and ultra-fine structured cast industrial grade hypereutectic Al-Si-Cu engineering material and processing technologies capable of maximizing its functional characteristics. This development will allow for further engineering of exceptionally lightweight and near net-shape components for aerospace and transportation applications. The research outcomes offer the design and casting communities with new capabilities enabling gains in component properties, productivity, rapid component design and manufacturing procedures. These procedures include industrial melt chemical and physical treatments and an ultra rapid Solution and Artificial Aging Heat Treatments. These approaches were not feasible due to problems such as the lack of scientific knowledge on industrial grades of nano Al-Si-X alloys, limited solid solubility of elements, inadequate wear resistance in extreme environments and the lack of physical simulation engineering tools. The patented Universal Metallurgical Simulator and Analyzer (UMSA) Technology Platforms’ capabilities were further developed to expedite Squeeze Casting (SC), Liquid and Semi-Solid melt processing using various pressure profiles for rapid physical simulations of these complex experimental industrial alloys. SC/HPDC UMSA experiments address: liquid and semi-solid chemical and dynamic physical treatments for structure control and elimination of solidification issues; neutralization of impurity elements; high temperature Solution Treatment and Artificial Aging; and elimination of the grain boundary precipitate-free zone that contributes to corrosion. The novel melt’s physical treatments include impact pressure, monotonic pressure and cyclic pressure loading profiles. Several novel as-cast and heat treated structures were developed and comprehensively characterized. Extensive UMSA Platform(s) processing and Thermal Analysis capabilities were enhanced, allowing for significant gains in understanding the link between processing parameters, Thermal Analysis data, and as-cast and heat treated material characteristics. The project utilized leading edge scientific methodologies for development of new cost effective nano and ultra-fine structured cast aluminum materials that will satisfy future fuel economy and emission targets

    Analysis of different MCTS implementations of artificial intelligence for the Children of the Galaxy computer game

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    Monte Carlo Tree Search (MCTS) is a popular game AI algorithm that searches the state space of a game while using randomized playouts to evaluate new states. There have been many papers published about various adjustments of the original algorithm, however, work that compares multiple of these algorithms together does not seem to exist. This lack of data can make it difficult to decide which variant to use without implementing and testing them which is potentially quite time-consuming. The aim of this thesis is therefore twofold. First to create such a comparison in a specific setting and second to introduce a new variant, WP MCTS, which is based on the idea that one should be able to gather more information from a playout by taking a look at all the states encountered during its computation. For our setting, we chose battles between small armies in a 4X computer game called Children of the Galaxy. The results presented here indicate that many, though not all tested variants outperform basic MCTS in this setting. 1Monte Carlo Tree Search (MCTS) je populĂĄrnĂ­ algoritmus pro umělou inteligenci do počítačovĂœch her, kterĂœ funguje na zĂĄkladě prohledĂĄvĂĄnĂ­ stavovĂ©ho prostoru hry za pouĆŸitĂ­ nĂĄhodnĂœch simulacĂ­ na ohodnocenĂ­ novĂœch stavĆŻ. Bylo jiĆŸ pub- likovĂĄno mnoho člĂĄnkĆŻ o rĆŻznĂœch ĂșpravĂĄch pĆŻvodnĂ­ho algoritmu, avĆĄak prĂĄce, kterĂ© by porovnĂĄvaly vĂ­cero těchto upravenĂœch algoritmĆŻ mezi sebou patrně neex- istujĂ­. Tenhle nedostatek dat mĆŻĆŸe pro vĂœvojáƙe činit vĂœběr varianty pro vlastnĂ­ Ășčely obtĂ­ĆŸnĂœm, aniĆŸ by je sĂĄm implementoval a otestoval - coĆŸ vĆĄak mĆŻĆŸe bĂœt časově nĂĄročnĂ©. Tato prĂĄce mĂĄ proto dva cĂ­le. PrvnĂ­m je porovnat rĆŻznĂ© vari- anty MCTS ve specifickĂ©m prostƙedĂ­ a druhĂœm je pƙedstavit novou variantu, WP MCTS, kterĂĄ vychĂĄzĂ­ z pƙedpokladu, ĆŸe pohledem na vĆĄechny stavy projedenĂ© pƙi simulaci by mělo bĂœt moĆŸnĂ© zĂ­skat vĂ­ce informacĂ­ neĆŸ jen obodovĂĄnĂ­m kon- covĂ©ho stavu. Pro naĆĄe prostƙedĂ­ jsme si vybrali souboje mezi malĂœmi armĂĄdami ve 4X počítačovĂ© hƙe zvanĂ© Children of the Galaxy. VĂœsledky prezentovanĂ© v tĂ©to prĂĄci indikujĂ­, ĆŸe mnohĂ©, avĆĄak ne vĆĄechny testovanĂ© varianty podĂĄvajĂ­ v tomto prostƙedĂ­ lepĆĄĂ­ vĂœkon neĆŸ pĆŻvodnĂ­ algoritmus. 1Department of Software and Computer Science EducationKatedra softwaru a vĂœuky informatikyMatematicko-fyzikĂĄlnĂ­ fakultaFaculty of Mathematics and Physic

    Development of Agricultural Market and Trade Policies in the CEE Candidate Countries.

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    This synthesis report focuses on the evolution of agricultural market and trade policies in the Central and Eastern European (CEE) candidate countries in the period 1997 to 2001. The developments were crucially influenced by (OECD, 2000a): ñ± the situation in world agricultural markets; ñ± the overall macroeconomic development in the countries considered; ñ± the prospective EU accession; ñ± bringing domestic agricultural policy in line with the Uruguay Agreement on Agriculture (URAA). High 1997 agricultural prices on world commodity markets were followed by a marked depression in 1998. With the exemption of milk products this trend continued in 1999. Likewise the economic and financial crisis in Russia had a considerable impact on agricultural policies. It hit the regions® exports resulting in a decline in industrial as well as agricultural output1. Thus, compared to the previous years most of the CEE candidate countries experienced a slow down or even negative rates of growth in their Gross Domestic Product (GDP) in 1998 and 1999. In addition those countries felt increased budgetary pressures. Agricultural market and trade policies largely reacted to these developments. Border protection was increased in many countries in 1998. This was combined in some cases with export subsidies, and ad hoc producer aids to mitigate the adverse effects. The prospect of EU accession also had an influence on the agricultural policy design in the region with many countries implementing EU-type policy instruments. Thus, the importance of per hectare and per head payments increased in the region, quota like measures were implemented in some countries and as part of this development Estonia introduced tariffs for agro-food imports. Finally, many countries also continued to adjust their policies to comply with their commitments agreed to in the World Trade Organisation (WTO). Despite these general tendencies there are also differences in the development of agricultural policies between the various CEE candidates. Chapter 2 therefore provides an overview of the changes of agricultural market and trade policies in each of the 10 accession countries. It addresses the policy issues market access (e.g. tariffs, special safeguard measures), export subsidies (value and quantities) and domestic support (intervention policies, direct payments, input subsidies, production quotas). Chapter 3 provides a brief assessment of recent policy developments in the region in the light of EU accession and WTO commitments. The development of prices and values, e.g. export subsidies, agricultural support expenditure, were presented in the background papers provided by the country experts in current prices in national currencies. In this synthesis report they are in addition converted in Euro. This firstly allows for a better comparison among the CEE candidate countries as well as between those countries and the EU. Some of the accession countries still suffer from high inflation and thus a strong depreciation of their currency. Thus secondly, the conversion to Euros allows the comparisons to be made in real terms.Industrial Organization, International Development, Productivity Analysis,

    Circular Supply Chains in Emerging Economies – a comparative study of packaging recovery ecosystems in China and Brazil

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    This paper provides a circular supply chain perspective of packaging recovery ecosystems being implemented by Tetra Pak, a prime global player in the food packaging industry, in two major emerging economies: China and Brazil. The circular supply chain archetype considered in the research allowed a consistent comparative analysis of Tetra Pak’s circular supply chains in both countries. Through a case study approach, the research provides theoretical propositions and learning points that are valuable for academics and practitioners interested in the Chinese and Brazilian markets as well as in the supply chains supporting recovery ecosystems in the packaging industry. In particular, the distinct environments in the Chinese and Brazilian markets render Tetra Pak opportunities to design circular supply chains in different ways showing adaptation and learning to local market characteristics. The industrial perspectives from these emerging economies add to the contributions offered in the paper. Overall, the conceptual considerations and practical recommendations presented in the paper provide useful insights for the development of further studies and implementation of industrial practices advocated by the circular economy

    Between overt and covert research: concealment and disclosure in an ethnographic study of commercial hospitality

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    This article examines the ways in which problems of concealment emerged in an ethnographic study of a suburban bar and considers how disclosure of the research aims, the recruitment of informants, and elicitation of information was negotiated throughout the fieldwork. The case study demonstrates how the social context and the relationships with specific informants determined overtness or covertness in the research. It is argued that the existing literature on covert research and covert methods provides an inappropriate frame of reference with which to understand concealment in fieldwork. The article illustrates why concealment is sometimes necessary, and often unavoidable, and concludes that the criticisms leveled against covert methods should not stop the fieldworker from engaging in research that involves covertness

    Cardiac iron concentration in relation to systemic iron status and disease severity in non-ischaemic heart failure with reduced ejection fraction

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    Aims: Low cardiac iron levels promote heart failure in experimental models. While cardiac iron concentration (CI) is decreased in patients with advanced heart failure with reduced ejection fraction (HFrEF), CI has never been measured in non-advanced HFrEF. We measured CI in left ventricular (LV) endomyocardial biopsies (EMB) from patients with non-advanced HFrEF and explored CI association with systemic iron status and disease severity. Methods and results: We enrolled 80 consecutive patients with non-ischaemic HFrEF with New York Heart Association class II or III symptoms and a median (interquartile range) LV ejection fraction of 25 (18–33)%. CI was 304 (262–373) ÎŒg/g dry tissue. CI was not related to immunohistological findings or the presence of cardiotropic viral genomes in EMBs and was not related to biomarkers of systemic iron status or anaemia. Patients with CI in the lowest quartile (CIQ1) had lower body mass indices and more often presented with heart failure histories longer than 6 months than patients in the upper three quartiles (CIQ2–4). CIQ1 patients had higher serum N-terminal pro-B-type natriuretic peptide levels than CIQ2–4 patients [3566 (1513–6412) vs. 1542 (526–2811) ng/L; P = 0.005]. CIQ1 patients also had greater LV end-diastolic (P = 0.001) and end-systolic diameter indices (P = 0.003) and higher LV end-diastolic pressures (P = 0.046) than CIQ2–4 patients. Conclusion: Low CI is associated with greater disease severity in patients with non-advanced non-ischaemic HFrEF. CI is unrelated to systemic iron homeostasis. The prognostic and therapeutic implications of CI measurements in EMBs should be further explored

    Colocalized neurotransmitters in the hindbrain cooperate in adaptation to chronic hypernatremia

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    Chronic hypernatremia activates the central osmoregulatory mechanisms and inhibits the function of the hypothalamic-pituitary-adrenal (HPA) axis. Noradrenaline (NE) release into the periventricular anteroventral third ventricle region (AV3V), the supraoptic (SON) and hypothalamic paraventricular nuclei (PVN) from efferents of the caudal ventrolateral (cVLM) and dorsomedial (cDMM) medulla has been shown to be essential for the hypernatremia-evoked responses and for the HPA response to acute restraint. Notably, the medullary NE cell groups highly coexpress prolactin-releasing peptide (PrRP) and nesfatin-1/NUCB2 (nesfatin), therefore, we assumed they contributed to the reactions to chronic hypernatremia. To investigate this, we compared two models: homozygous Brattleboro rats with hereditary diabetes insipidus (DI) and Wistar rats subjected to chronic high salt solution (HS) intake. HS rats had higher plasma osmolality than DI rats. PrRP and nesfatin mRNA levels were higher in both models, in both medullary regions compared to controls. Elevated basal tyrosine hydroxylase (TH) expression and impaired restraint-induced TH, PrRP and nesfatin expression elevations in the cVLM were, however, detected only in HS, but not in DI rats. Simultaneously, only HS rats exhibited classical signs of chronic stress and severely blunted hormonal reactions to acute restraint. Data suggest that HPA axis responsiveness to restraint depends on the type of hypernatremia, and on NE capacity in the cVLM. Additionally, NE and PrRP signalization primarily of medullary origin is increased in the SON, PVN and AV3V in HS rats. This suggests a cooperative action in the adaptation responses and designates the AV3V as a new site for PrRP's action in hypernatremia
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