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  • 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.
451

Mutační analýza genu TRPC6 u pacientů s nefrotickým syndromem / Mutational analysis of the TRPC6 gene in patients with nephrotic syndrome

Obeidová, Lena January 2011 (has links)
Focal segmental glomerulosclerosis is one of the commonest cause of the nephrotic syndrome in adults patients. It is a damage of glomerulus characterized by leakage of proteins to urine and oedemas which usually develops into the end-stage renal disease within 10 years. Recently have been described familial forms of this disease which arise from injury to proteins making up filtration barrier of kidney. In 2005 non-selective ion channel TRPC6 was assigned among these proteins. In this thesis I focused on summarizing existing knowledge of the nephrotic syndrome, focal segmental glomerulosclerosis and involvement of TRPC6 in their origin. Second part of this work is devoted to the screening analysis of TRPC6 gene to discover possible mutations and polymorfisms in 47 patients with histologically proven focal segmental glomerulosclerosis or minimal change disease. The used methods were high resolution melting and direct sequencing. In the group of patients was detected no pathogenic mutation, only 2 known polymorfisms P15S and A404V and few changes which do not result in alteration of amino acid. So it seems TRPC6 gene mutations are a rare cause of the focal segmental glomerulosclerosis in adult patients in the Czech Republic.
452

Energy Consumption and Carbon Footprint of Secondary Aluminum Cast House

Wei, Wenjing January 2012 (has links)
Primary aluminum production brings about severe environmental burden due to its energy intensive process.  Secondary aluminum production contributes to cutting off high energy demand around 90-95% and greenhouse gas emission by remelting scraps. However, previous research indicates melting furnace’s energy efficiency in secondary plant is still very low, which is around 26-29% and more than 70% heat is lost in different way. The objective of this project is to investigate energy consumption and greenhouse gas (GHG) emission in secondary aluminum cast house through process analysis. The result offers a comprehensive overview to aid decision-maker to compare energy consumption and environmental impacts caused by different product or process. This project has been done in collaboration with SAPA Heat Transfer. This project consists of two tasks. First task is aimed to give an overview of annual energy distribution and carbon footprint of per ton aluminum slab in SAPA cast house. In order to analyze energy distribution, mass and energy conservation has been applied for calculation. Meanwhile, International standard method, life cycle assessment, has been used to evaluate greenhouse gas contribution of the whole production process. The second task intends to investigate two effects (melting furnace type, raw material type) on products’ energy consumption and carbon footprint.  Melting furnace’s effect is compared by selecting electric induction furnace and oxy-fuel furnace. On the other hand, raw material’s effect is studied by comparison of four different cast house products which have different raw material recipe. Calculation and analysis results indicates that per ton Sapa cast house aluminum slab consumes energy 3826MJ and contributes to 306kgCO2eq. green house gas. Meanwhile, comparison results show that oxy-fuel melting furnace has higher energy efficiency than electric induction furnace, however, it contributes much more GHG due to consumption of propane fuel. In addition, primary ingot has been concluded as distinct carbon footprint contribution than others contributors (i.e. fuel) for Sapa cast house’s slab.
453

A study of micro- and surface structures of additive manufactured selective laser melted nickel based superalloys

Strand, Emil, Wärnheim, Alexander January 2016 (has links)
This study examined the micro- and surface structures of objects manufactured by selective laser melting (SLM). The results show that the surface roughness in additively manufactured objects is strongly dependent on the geometry of the built part whereas the microstructure is largely unaffected. As additive manufacturing techniques improve, the application range increases and new parameters become the limiting factor in high performance applications. Among the most demanding applications are turbine components in the aerospace and energy industries. These components are subjected to high mechanical, thermal and chemical stresses and alloys customized to endure these environments are required, these are often called superalloys. Even though the alloys themselves meet the requirements, imperfections can arise during manufacturing that weaken the component. Pores and rough surfaces serve as initiation points to cracks and other defects and are therefore important to consider. This study used scanning electron-, optical- and focus variation microscopes to evaluate the microstructures as well as parameters of surface roughness in SLM manufactured nickel based superalloys, Inconel 939 and Hastelloy X. How the orientation of the built part affected the surface and microstructure was also examined. The results show that pores, melt pools and grains where not dependent on build geometry whereas the surface roughness was greatly affected. Both the Rz andRa values of individual measurements were almost doubled between different sides of the built samples. This means that surface roughness definitely is a factor to be considered when using SLM manufacturing.
454

Investigation of processing parameters for laser powder bed fusion additive manufacturing of bismuth telluride

Rickert, Kelly Michelle 02 June 2022 (has links)
No description available.
455

The mechanical properties of lattice truss tructures with loadbearing shells made of selectively laser melted Hastelloy X (TM)

Saarimäki, Jonas January 2011 (has links)
This thesis discusses how to test the mechanical properties of openlattice truss structures and hybrids being a tube containing a latticetruss structure. By properties we mean strength, stiffness, thermalconductivity and so forth.Mechanical testing was done on two different structures to betterunderstand how the load-bearing properties change when these structuresare subjected to tensile, compressive and bending forces. The structuresinvestigated were Diamond and Octagon built at 45° and 90°. Acousticemission was also used to evaluate and analyze the different behaviour ofthe structures. The test results were used to produce design criteria forproperties in different cell structures manufactured of Hastelloy X™. Amap with design criteria containing stiffness and weight per cubiccentimetre was produced for parts that would be subjected to compressiveforces.
456

Macro composites for crushing - additive manufacturing of hard phase : Development and testing of macro composites for crushing purposes

Wojtowicz, Maria January 2021 (has links)
During this master thesis a crushing material composite was developed in order to determine if a specific design consisting of a pointy hard phase with a ductile phase in between can reduce the load needed to crush stone and therefor decrease the energy consumption during stone crushing. The steel hard phase (ASP 2012) was printed using an additive manufacturing method called selective laser melting (SLM). A process parameter optimization was performed in order to achieve a dense material and a pre-heated building platform was used to prevent cracking. The hard phase designs were printed and then filled with bronze (JM3 and JM7). The composites and steel references were tested by placing a stone on each sample and applying pressure until the stone broke. After the tests, the loads and the deterioration of the samples was analyzed. The results showed that it was possible to print the hard phase, but some defects like micro cracking were hard to eliminate entirely. Several methods were tested to cast the bronze but the most suitable during this project was melting of the bronze in an induction furnace with vacuum atmosphere. The results from the crushing simulations showed that there was a small difference between the references and the developed macro composites. The composites began to crush stones at lower loads than the references. Nevertheless, due to a large dispersion of the results a statistical difference could not be established.
457

Phase relation in ternary feldspar system at high temperature and evolution of micro-texture of natural ternary feldspar in UHT-metamorphic rock from Mt. Riiser-Larsen, East Antarctica / 高温下におけるternary feldsparの相関係と東南極Riiser-Larsen山に産するternary feldsparの微細組織の成因について

Kodama, Yu 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18087号 / 理博第3965号 / 新制||理||1572(附属図書館) / 30945 / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)准教授 三宅 亮, 教授 土`山 明, 准教授 河上 哲生 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
458

Residual Stress Enhancement of Additively Manufactured Inconel 718 by Laser Shock Peening and Ultrasonic Nano-crystal Surface Modification

Sidhu, Kuldeep S. January 2018 (has links)
No description available.
459

Microstructure and Mechanical Properties of Laser Additively Manufactured Nickle based Alloy with External Nano Reinforcement: A Feasibility Study

Wang, Yachao 30 October 2018 (has links)
No description available.
460

A Lagrangian Meshfree Simulation Framework for Additive Manufacturing of Metals

Fan, Zongyue 21 June 2021 (has links)
No description available.

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