Objective of diploma thesis is to proceed analysis of actual technology in operational terms for concrete casting of bearing . Constructed by foundry of steel ŽĎAS a.s., Žďár nad Sázavou. After designing changes in technological process accomplish detail evaluation of mechanical properties and chemical homogenity of metal at selected parts of sample casting.

For TIG welding of transformer fame is important enough weld root fusion, however exposed surfaces must remain unaffected. Three types of test were made to determine properties of welds under different conditions. Tests were macroscopic inspection, tensile test and fracture test. Next was economic evaluation of different methods. Best results were for single layer weld with pre-heated material.

The diploma thesis deals with problems of identification and specification of insurmountable impairments with a focus on moisture. The aim of my work is generally explain what the fault and failure, what is their cause, and the overall approach in this area. Next determine the difference between removable and irremovable defect. Part of this work is a chapter devoted to surveys of buildings, which are an integral part in detecting defects, failures and their root structures. Another section is devoted to the main subject of work - moisture, approach this issue and the problems caused by moisture in the structure. At the end of this chapter is about ways of reducing the moisture in structures. The last section is on the case (the object affected moisture) approach procedure for identifying and assessing these impairments in practice.

This thesis deals with the issue of determining the causes of defects and failures, focusing on a specific property and their significance in determining the price of the property. The first part focuses on the theory explaining the basic concepts used in the valuation of real estate, basic methods of property valuation and classification of construction defects and failures. This chapter includes an analysis of the real estate market in the years 2008 - 2013. The second part is devoted to determining the amount of property damage at a specific property, the calculation of this particular property which is based on technical surveys and subsequent valuation of the property with regard to the results of the survey. The aim is to create a design procedure for reducing the price of the property with the defect.

Legal rules and regulations, which are engaged in forensic engineering including expert evidence’s requirements, are because of the difference of this sphere very universal and common. Due to this situation, legal orders and regulations can not standardize and harmonize expert procedures for particular branches or their specific parts. The Dissertation thesis is focused on a elaboration of the methodology procedure for expert evidence’s elaborations, which analyze defects and imperfections in new-built flats.

abstract: Semiconductor devices often face reliability issues due to their operational con- ditions causing performance degradation over time. One of the root causes of such degradation is due to point defect dynamics and time dependent changes in their chemical nature. Previously developed Unified Solver was successful in explaining the copper (Cu) metastability issues in cadmium telluride (CdTe) solar cells. The point defect formalism employed there could not be extended to chlorine or arsenic due to numerical instabilities with the dopant chemical reactions. To overcome these shortcomings, an advanced version of the Unified Solver called PVRD-FASP tool was developed. This dissertation presents details about PVRD-FASP tool, the theoretical framework for point defect chemical formalism, challenges faced with numerical al- gorithms, improvements for the user interface, application and/or validation of the tool with carefully chosen simulations, and open source availability of the tool for the scientific community. Treating point defects and charge carriers on an equal footing in the new formalism allows to incorporate chemical reaction rate term as generation-recombination(G-R) term in continuity equation. Due to the stiff differential equations involved, a reaction solver based on forward Euler method with Newton step is proposed in this work. The Jacobian required for Newton step is analytically calculated in an elegant way improving speed, stability and accuracy of the tool. A novel non-linear correction scheme is proposed and implemented to resolve charge conservation issue. The proposed formalism is validated in 0-D with time evolution of free carriers simulation and with doping limits of Cu in CdTe simulation. Excellent agreement of light JV curves calculated with PVRD-FASP and Silvaco Atlas tool for a 1-D CdTe solar cell validates reaction formalism and tool accuracy. A closer match with the Cu SIMS profiles of Cu activated CdTe samples at four different anneal recipes to the simulation results show practical applicability. A 1D simulation of full stack CdTe device with Cu activation at 350C 3min anneal recipe and light JV curve simulation demonstrates the tool capabilities in performing process and device simulations. CdTe device simulation for understanding differences between traps and recombination centers in grain boundaries demonstrate 2D capabilities. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019

abstract: Extended crystal defects often play a critical role in determining semiconductor device performance. This dissertation describes the application of transmission electron microscopy (TEM) and aberration-corrected scanning TEM (AC-STEM) to study defect clusters and the atomic-scale structure of defects in compound semiconductors. An extensive effort was made to identify specific locations of crystal defects in epitaxial CdTe that might contribute to degraded light-conversion efficiency. Electroluminescence (EL) mapping and the creation of surface etch pits through chemical treatment were combined in attempts to identify specific structural defects for subsequent TEM examination. Observations of these specimens revealed only surface etch pits, without any visible indication of extended defects near their base. While chemical etch pits could be helpful for precisely locating extended defects that intersect with the treated surface, this study concluded that surface roughness surrounding etch pits would likely mitigate against their usefulness. Defect locations in GaAs solar-cell devices were identified using combinations of EL, photoluminescence, and Raman scattering, and then studied more closely using TEM. Observations showed that device degradation was invariably associated with a cluster of extended defects, rather than a single defect, as previously assumed. AC-STEM observations revealed that individual defects within each cluster consisted primarily of intrinsic stacking faults terminated by 30° and 90° partial dislocations, although other defect structures were also identified. Lomer dislocations were identified near locations where two lines of strain contrast intersected in a large cluster, and a comparatively shallow cluster, largely constrained to the GaAs emitter layer, contained 60° perfect dislocations associated with localized strain contrast. In another study, misfit dislocations at II-VI/III-V heterovalent interfaces were investigated and characterized using AC-STEM. Misfit strain at ZnTe/GaAs interfaces, which have relatively high lattice mismatch (7.38%), was relieved primarily through Lomer dislocations, while ZnTe/InP interfaces, with only 3.85% lattice mismatch, were relaxed by a mixture of 60° perfect dislocations, 30° partial dislocations, and Lomer dislocations. These results were consistent with the previous findings that misfit strain was relaxed primarily through 60° perfect dislocations that had either dissociated into partial dislocations or interacted to form Lomer dislocations as the amount of misfit strain increased. / Dissertation/Thesis / Doctoral Dissertation Physics 2020

The beginning of the space-age in the 1950s led to interest in the effects of radiation on semiconductors. The systematic investigation of defect centres in semiconductors began in earnest over 30 years ago. In addition to defect identification, information was also obtained on energy-level structures and defect migration properties. When designing electronic systems for operation in a radiation environment, ~tis imperative to know the effect of radiation on the properties of electronic components and materials comprising these systems. In some instances, the effects of irradiating electronic materials can be used to obtain desired material properties (mesa isolation, implantation, etc.). However, when electronic devices are exposed to radiation, defects may be introduced into the material. Depending on the application, these defects may have a detrimental effect on the performance of such a device. For this study, the semiconductor gallium arsenide (GaAs) was used and the defects were introduced by electrons, alpha-particles, protons, neutrons and argon sputtering. These particles were generated using radio-nuclides, a high-energy neutron source, a 2.5 MV Van de Graaff accelerator and a sputter gun. The influence of particle irradiation on the device properties of Schottky barrier diodes (SBDs) fabricated on GaAs is presented. These device properties were monitored using a variable temperature current-voltage (I-V) and capacitance-voltage (C-V) apparatus. In order to have an understanding of the change in electrical properties of these contacts after irradiation, it is necessary to characterize the radiation-induced defects. Deep level transient spectroscopy (DLTS) was used to characterise the defects in terms of their DLTS "signature", defect concentration, field enhanced emission, and thermodynamic properties. / Thesis (PhD)--University of Pretoria, 1994. / gm2014 / Physics / unrestricted

Les travaux menés pendant cette thèse se concentrent sur l'étude de technologies avancées de MOSFET, plus précisément de FinFET à triple-grille et de nanofils à grille enrobante. Ils ont été fabriqués pour le nœud technologique 10 nm, suivant le même procédé de fabrication à l'exception de la fabrication d'une quatrième grille pour les nanofils. Ces composants sont étudiés en régime statique afin de déterminer les principaux paramètres de leur modèle électrique. Des études à très faible température (< 10 K) et faible tension de drain (< 1 mV) montrent la présence de transport quantique dû aux niveaux d'énergie discrets dans les bandes de conduction et de valence. L'étude du bruit électrique en 1/f montre une bonne maîtrise du procédé d'oxydation de la grille ainsi que le changement de mécanisme de bruit sous l'effet de transport quantique. Différentes spectroscopies de bruit basse fréquence (i.e. étude du bruit de génération-recombinaison en fonction de la température) ont permis d'identifier les pièges contenus dans le film de silicium, donnant ainsi la possibilité d'incriminer les étapes de fabrications les plus critiques. / The work led within this thesis focuses on the study of advanced MOSFET technologies, more precisely of triple-gate FinFETs and Gate-All-Around nanowire FETs. They were fabricated for the 10-nm technological node, following the same recipe except for the build of a fourth gate in nanowire devices.The devices have been studied in static regime in order to determine the main parameters of their electrical model. Low temperature (<10 K) and low drain voltage (1mV) studies highlighted the existence of quantum transport that is due to discrete energy levels within the conduction and valence bands. The study of the 1/f noise testifies the good control of the gate oxidation process and evidences a change in the noise mecanism under quantum transport.Numerous low frequency noise spectroscopies (i.e. study of the generation-recombination noise as a function of the temperature) let us identify silicon film traps, thus giving indication of the critical process steps that are responsible for the generation-recombination noise.

Title: Postural stability of near-sighted people Objectives: To analyse relationships between selected parameters of postural stability and impaired visual acuity (myopia), which is revised by optimal visual correction, by diffusing glasses or by contact lenses. Methods: Investigations of stabilizing capabilities of erected posture in its various modifications. An objective measuring was performed by stabilometric platform type Footscan. The experiment involved twelve people with myopia of -3 to -6D visual acuity of an average age of 23 ± 4 years. Myopat group of bipedal standing position were tested with open eyes with vision correction, afterwards with eyes closed, then without any vision correction. The last measured positions were performed on one lower limb with visual correction and then without it. Total number of measured positions were ten upright positions, each of which was measured with 30 second interval. Results: A total travelled way of centre of pressure was determined as a parameter of postural stability evaluating. Positions on one lower limb clearly put the highest demands for stabilizing upright positions. The only aggravation of conditions stabilizing this position should be to eliminate vision correction, which was confirmed in 8 probands from a total of 12. Under a bipedal...