Dissertations / Theses on the topic 'TiS3'

Neste trabalho foram estudadas diferentes modificações superficiais do titânio (Ti) como método de preparação de superfícies de eletrodos para baterias de íons lítio (Li+) Inicialmente, as modificações foram produzidas pelas micro-indentações, com posterior corrosão eletroquímica por pites em soluções de brometo. As superfícies polidas, tratadas termicamente e modificadas através de micro-indentações foram avaliadas em diferentes parâmetros, tais como o potencial aplicado, concentração dos íons agressivos no eletrólito, temperatura, tempo dos testes e principalmente, sobre o impacto das deformações causadas pela força indentações para localização de orifícios produzidos por pites. Filmes porosos de titânia (TiO2) crescidos sobre o Ti puro, foram produzidos por anodização a plasma (anodização por centelhamento ou sparking) em 1M H3PO4 e em 1M Na2SO4 e por anodização nanotubular em 1M H3PO4 + 1M NaOH + 0,4 %(peso) HF. Os resultados mostraram, em óxidos tipo “esponja” formados na anodização a plasma em 1M H3PO4 e 1M Na2SO4, a incorporação de elementos do eletrólito contendo, respectivamente, P e S, numa relação de P/O > S/O e em óxidos nanotulares, a predominante incorporação de elemento de F. Posteriormente, as superfícies corroídas por pites e as superfícies de óxidos crescidos por anodização a plasma foram convertidas por sulfetação em diferentes materiais micro e nanoestruturados compostos por sulfetos e oxisulfetos de titânio, ajustando-se as condições de processo. O desenvolvimento proposto mostrou que é possível modificar a composição química do óxido formado por anodização a plasma para nanocristais de TiS2, nanofitas de TiS3 e TiOxSy, sem danificar a morfologia original dos nanoporos de TiO2. Os compostos formados podem ser usados como eletrodos nanoarquiteturados tridimensionais (3D) para microbaterias de íons lítio (Li+) com alta densidade de potência. A síntese desses compostos é realmente promissora, porque eles têm a capacidade de inserir mais íons lítio do que TiO2 puro, resultando em uma melhoria na capacidade das microbaterias.
In this study, different surface modifications of titanium (Ti) were studied as a method of surface preparation of electrodes for ion lithium batteries (Li+). Initially, the modifications were produced by micro-indentation with subsequent electrochemical pitting corrosion in solutions of bromide. The polished surfaces, heat treated and modified through micro indentations were evaluated for different values of parameters, such as applied potential, concentration of aggressive ions in the electrolyte, temperature, polarization time, and mainly intensity of the deformation caused by indentations for localizing holes produced by pitting. It was expected the adjust of location of these parameter settings promotes nucleation of pits, according to the pattern of indentations and growth of pitting depth for increased surface area. Porous films of titania (TiO2) were produced on pure Ti by plasma anodization (or sparking) in 1M H3PO4 and 1M Na2SO4. Nanotubes were synthesized by porous anodization in 1M NaOH + 1M H3PO4 + 0.4 (wt%) HF. The results showed oxide "sponge" like formed by plasma anodization, incorporating elements of the electrolyte containing respectively, P and S in a ratio P/O> S/O and, in nanotubular oxides, with predominant incorporation of F. Subsequently, the pitted surfaces and the surfaces of oxides grown by plasma anodization were converted by sulfidation into different micro and nanostructured materials consisting of titanium sulfide and oxisulfides by adjusting the process conditions. The proposed development has shown that it is possible to modify the chemical composition of the oxide formed by plasma anodizing to nanocrystals of TiS2 and nanobelts of TiS3 and TiOxSy without damaging the original morphology of the nanoporous TiO2. The formed compounds can be used as three-dimensional (3D) nanoarchitectured electrodes for ion lithium batteries (Li+) with high power density. The synthesis of these compounds is promising due to a higher ability to intercalate more ions lithium than pure TiO2, resulting in an improvement in the capacity of microbatteries.

This diploma thesis is focused on material printing of light dosimeters, especially printing of dosimeters for visible light and two types of UV radiation dosimeters. The aim of this work was to convert optimized systems from laboratory scale to pilot plant and to prepare individual systems for large-scale printing. The experimental part deals with the preparation and gradual scaling of compositions to a pilot scale, including optimization of individual components. Problems which were found during scaling up are discussed. A roll-to-roll material printer with slot-die technique was used to convert to a pilot scale. The prepared layers were exposed and their color changes was studied in detail. In addition to printing optimization, the thicknesses of the prepared layers and their resistance were determined, as well as tests of shelf life and reaction of dosimeters to ozone. According to the tests which were performed, guidelines for quality control of light dosimeters printing were compiled.

This study presents various methods of measuring ozone and consolidates current state of knowledge in the field of disposable printed ozone dosimeters. The paper also identifies prospective dyes for preparation of ozone dosimeters available on the market. Information gathered from literature review was used to prepare dosimeters based on two different dyes. These were calibrated for screen printing technology and their sensitivity to ozone was optimized to achieve visual detectability. Prepared samples were observed and studied while being exposed to ozone. Then, long term mechanical and chemical properties of these were tested in order to identify appropriate conditions for storage.

The subject of this these is a preparation and printing of upconversion marks that have been printed by two printing techniques, namely screen printing and pad printing. The makrs were designed to visualize another chemical code identifiable by instrumentation. The impact of chemical code components on the fluorescence intensity of upconversion marks and the impact of individual components on printability and print sustainability were studied. The upconversion pigment was excited by NIR laser.

The submitted thesis deals with a study of composite materials and processing them using 3D printing technology. The experimental part of this thesis is focused on the production of test samples with the use of additive technology Fused Deposition Modeling and Continuous Filament Fabrication. The composite samples made of common onyx material, individually reinforced with continuous carbon fiber filaments, kevlar, or fiberglass, were made with Marforged Mark Two 3D printer. The other samples made of PETG PM and PETG CFjet materials were made with Original Prusa i3 MK2S 3D printer. For technological evaluation, a tensile test was performed on samples, following the norm EN ISO 527-2:2012. Based on results obtained from tensile testing, the properties of materials strength and usability are verified and compared. In this work, the production process is proposed, and technical-economic evaluation is made. In conclusion, achieved results and overall benefits of this work are summarised.

The diploma thesis presents an overview of additive production technologies and a summary of technologies used for 3D metal printing using a robot. All of them are generally described and at the same time assigned to their specific commercial use, or the academic research that deals with them. The work examines the suitability of the material EN ISO 14341-A: G 3Si1 for 3D printing, for which a modification of the Col Metal Transfer technology, Cycle Step is used. The experimental printout of the sample is evaluated on the basis of surface and mechanical tests. Capillary test, examination of microstructure a macrostructure, tensile test and microhardness test. All of them were satisfactory and the suitability of the welding wire for 3D printing was confirmed by the given technology.

Optomechanical components are widely used in many optical experiments. This diploma thesis deals with design and manufacturing optomechanical components using 3D print technology. These are cheaper alternatives of commercial devices. In addition to 3D printed parts, minimum number of other components are used to assemble functional devices. Using simple experimental setups, the manufactured components are evaluated and compared with commercially available ones. The results show that they can be used in applications where high accuracy is not required. The second part is devoted to the design and manufacturing of a polarimeter as a mechanism combining electrical and mechanical components with 3D printed parts. The polarimeter is used to measure some properties of polarized light.

This work deals with the problem of the thick-film pastes and their printing. In the main chapter of this work, the realization of a workplace for thick-film pastes' printing is described. The construction of the realized plotter and the controlling electronics of the plotter is depicted in detail.In the following chapter, the console, through which the plotter is controlled via PC, and the CAD program, which serves for projecting of the motives printed, are described.In the final chapter of this work, the measured profiles of the paste printed for various settings of printing parameters and the photographs of the motives printed are stated.

The subject of this theses is a preparation of chemical UV dosimeters working on diverse principles and their printing. Three UV dosimeters were prepared. The first one is based on a photocalalytic reaction of titanium dioxide with redox dyes. Two other dosimeters are based on a reaction of a photolabile substance able to produce an intermediate reacting with a dye. Prepared dosimeter compositions were coated using a material roll-to-roll printing machine on a corona-treated PET foil. Prepared dosimeter compositions were calibrated for desired exposition to UV radiation doses. Validity of a reciprocity law was verified.

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Financiadora de Estudos e Projetos
In this work, the lead-free ceramic powders of xBi0,5Na0,5TiO3 - (0,7186 - 0,7143x) Bi0,5K0,5TiO3 - (2814 - 2857x) BaTiO with x = 0,8200; 0,8625; 0,8792, 0,9126 and 0,9300 (BNBK1000x) were prepared by the solid state reaction method, followed by conventional densification. The ceramic bodies showed high density, which was higher than 95% in obtained samples. For the all ceramics were performed structural, micro structural, electric and anelastic characterizations. The X-ray diffraction (XRD) analysis indicated the formation of the complex perovskite type crystaline structure for all compositions analyzed without the presence of spurious phases. By the structural refinement by the Rietveld method of XRD data and by Raman spectroscopy were observed that for BNBK912 and BNBK930 compositions, at room temperature, the predominant symmetry is rhombohedral (R3c), while the BNBK820 composition exhibits a tetragonal crystalline symmetry (P4mm). For the BNBK879 and BNBK826 compositions presented a mixture of phases, possibly with rhombohedral and tetragonal symmetry, reaveling the morphotropic phase boundary (MPB) of this system. The microstructure of BNBK1000x ceramics was investigated by scanning electron microscopy (SEM), where the morphology grains with irregular sizes and shapes, where the increased levels of K+ and Ba2+ ions suppressed the growth of the grains. The characterizations by Raman spectroscopy at room temperature showed broad Raman modes, due to the chemical and/or structural disorder related to the substitution of elements Bi and Na for Ba and K. The ferroelectric characterizations at room temperature of the BNBK1000x ceramics showed that all compositions studied are ferroelectric. Through the comparison among the measurements of electrical impedance and mechanical spectroscopy, was possible to identify the different structural and electric phase transitions that were employed in the construction of a pseudodiagram of phases for the BNBK1000x compositions.
Neste trabalho, os pós-cerâmicos livres de chumbo xBi0,5Na0,5TiO3 - (0,7186 - 0,7143x) Bi0,5K0,5TiO3 - (2814 - 2857x) BaTiO com x = 0,8200; 0,8625; 0,8792, 0,9126 e 0,9300 (BNBK1000x) foram obtidos através do método de reação de estado sólido, seguido por densificação convencional. Os corpos cerâmicos obtidos apresentaram elevada densificação, sendo maior que 95% nas amostras produzidas. Para todas as cerâmicas foram realizadas caracterizações estruturais, microestruturais, elétricas e anelásticas. As análises por difração de raios-X (DRX) indicaram a formação da estrutura cristalina tipo perovkista complexa para todas as composições analisadas, sem a presença de fases espúrias. O refinamento estrutural, pelo método de Rietveld, dos resultados de DRX e os resultados de espectroscopia Raman apontam que para as composições BNBK930 e BNBK912 a simetria predominante em temperatura ambiente é romboédrica (R3c), enquanto que a composição BNBK820 apresenta a simetria cristalina tetragonal (P4mm). Já as composições BNBK879 e BNBK862 apresentaram uma mistura de fases, possivelmente com simetrias romboédrica e tetragonal, evidenciando o contorno de fase morfotrópico (CFM) deste sistema. A microestrutura das cerâmicas de BNBK1000x foi investigada por microscopia eletrônica de varredura (MEV), onde a morfologia apresentada pelas diferentes composições estudadas possuíam grãos com tamanhos e formatos irregulares, sendo que o aumento dos teores dos íons de K+ e Ba2+ inibiram o crescimento dos grãos. A caracterização por espectroscopia Raman, em temperatura ambiente, apresentou modos Raman amplos, mostrando um elevado grau de desordem química e/ou estrutural devido à substituição dos elementos Bi e Na por Ba e K. As caracterizações ferroelétricas, também em temperatura ambiente das cerâmicas de BNBK1000x mostraram que todas as composições estudadas possuem propriedades ferroelétricas. Através da comparação entre as medidas de impedância elétrica e anelástica, levando em consideração as caracterizações estruturais e ferroelétricas com temperatura, foi possível identificar diferentes transições de fase estruturais e elétricas, que foram empregadas na construção de um pseudo-diagrama de fases para as composições de BNBKx.

This thesis focuses on the description of 3D printing technologies using the FDM method, which uses deposition of molten thermoplastics and their subsequent cooling and solidification layer by layer. This unique structure then shows a strong anisotropy of mechanical properties and, as a result, their testing and print settings are very important. Tensile testing of plastic materials, including indicators of mechanical properties, are described in this thesis according to ČSN EN ISO standard. The practical part presents the concept of a device capable of performing these tests. The block diagram indicates the functional elements and the connections among them. Tensile strength test is described together with results processing. Necessary product documentation is also included.

This diploma thesis deals with the study of 3D printing based on the FDM method. This method focuses on the possibility of using two extruders it means that the composite parts can be printed. This diploma thesis describes the available variants of composite printing currently on the market. Based on the gained knowledge and the availability of 3D printers and software, individual variants of composite parts were printed. A tensile test was performed on these samples to determine the strength characteristics. Additionally, compatibility and adhesion of two selected materials were tested. Based on the testing is made an evaluation of the achieved results, effectiveness and feasibility.

This diploma thesis deals with material printing using roll to roll material printer. Several kinds of printing inks were prepared and their parameters, like viscosity and homogeneity were optimized. Corona treated PET foil was used as the flexible substrate. Thin layers of function material were prepared by coating by using the smooth cylinder and slot die method. Layers homogeneity was characterized by optical density. Layer thickness was measured by profilometer.

El curso Francés TI3 valida el tercer nivel de dominio de la lengua francesa (nivel B1 del Marco Comuìn Europeo de Referencia de las Lenguas) que permite a futuros traductores e intérpretes profesionales comunicarse en términos independientes en forma oral y escrita en francés para desempeñarse en situaciones cotidianas, teniendo una base sólida para el desarrollo de la competencia comunicativa en francés a lo largo de su vida. El curso de Francés TI3 desarrolla la competencia lingüística y cultural en francés a fin de favorecer el crecimiento cognitivo, cultural y humano necesarios para futuros traductores e intérpretes profesionales y propias de un usuario independiente que comprende los puntos principales de textos claros, sabe desenvolverse en la mayor parte de situaciones y es capaz de producir textos sencillos y coherentes. El curso tiene como prerrequisito haber superado el curso Francés TI2. El curso contribuye directamente al desarrollo de las competencias generales de Comunicación Oral y Escrita y la competencia específica de Segundas Lenguas, a un nivel 2.

The field of this work was to create a web application easing shipper's and carrier's work with consignments. The purpouse of the application is evidence of packages combined with label printing. A prewiew of present-day web application development techniques is provided first. Recent package delivery systems are discussed then. The application specification is the next topic. Implementation process using C# ASP .NET and the results of this work is analyzed in the last chapters.

The goal of the thesis was to design a piston manufactured by conventional method and subsequently adjusted one for additive manufacturing. Beside the designs, thermo-structural model was created for both pistons, considering maximal loading of the engine. Analysis evaluation showed the possibility of further application of the new technology in comparison to current one, within automotive industry.

This thesis deals with 3D printing, materials used for 3D printing, testing of the materials and learning their real parameters. Goal of the thesis is comparing selected materials, executing series of mechanical test and selecting suitable material for printing high-quality plastic parts for use in automobiles, especially for reproduction of parts that are no longer made for oldtimers and for use in motorsport.

This diploma theses is about the study of the effect of individual components of printing compositions intended for material printing of identificaton codes, read by X-ray fluorescence. Two printing technologies were used – screen printing and pad printing. The composition of the print compositions has been optimized in term of visual recognition, print repeatability, a dry matter content providing an X-ray fluorescence signal, as well as optimization of the material print process leading to the creation of invisible identification tags for archive documents.

Práca sa zaoberá problematikou slovenského štátu, slovenskými autonómi snahami od 19. storočia až po prvú ČSR, priebehom veľkej hospodárskej krízy na Slovensku. Ďalej popisuje dôležité medzníky vo vývoji v slovenskej politiky medzi rokmi 1938-1939, od vyhlásenia autonómie, Viedenkej arbitráže, vzniku samostatného slovenského štátu až po rokovania v Salzburgu. Zaoberá sa tieže slovensko-nemeckou hospodárskou a finančnou spoluprácou, slovenským vojnovým hospodárstvom, slovenským peňažníctvom a rieši otázku možnosti vlasnej slovenskej politiky nezávisle na Nemecku a úlohu Dr. J. Tisu.

In December 2015 the next part of the research population yew (Taxus baccata) took place in NPR Chlumská stráň. The specimens exceeding 4 meters at height at which the sex is possible to determine were selected from the total population. And from this group 50 individuals were randomly selected and the following characteristics were measured height, breast-height diameter, girth, height deployment of the first green branches, distances ends of the branches from the trunk, a distance of 5 nearest trees, their height and azimuth, also was intended sexes and crown shape. Volume and height of the crown were calculated. The aim is to determine how the surrounding tree species affect mensurational characteristics of the yew not only basic characteristics such as thickness at breast height and tree height, crown but also the crown characteristics and health status. The average diameter of the examined yews is 41,53 cm and a height of 13,66 m. The yew crowns were investigated in detail. The most important and interesting data are the yew crown projection and distances of competing species. The average crown projection yew is 79,25 square meters, the average height of the crown is 12,26 m, the surface of the crown is 2531,46 square meters, the average crown width is 10,36 m and the average volume of 429,80 cubic meters. 95 % of all surveyed yew has asymmetric crown, making it likely the high impact of competitive species. The most abundand species of competitors is hornbeam (Carpinus betulus) with a total of 60 individuals, an average height of 13,6 meters and an average distance of 5,79 meters, followed by lime(Tilia cordata) and manna ash (Fraxinus ornus). Crown yew are deflected to the north, northwest and west direction because of terrain conditions and competing trees. Research in the future should be also focused to the marginal tree species and for yew it should be very appropriate to establish permanent sample plots and to use collected information for return of yew to our forests.

The thesis deals with 3D printing by the FDM and ambient temperature on print quality. The thesis describes the principle of printing by the FDM method and the occurrence of errors caused by the influence of ambient temperature. The aim of the thesis is to design a heated chamber for RepRap Prusa i3 printer, its construction and subsequent testing of ambient temperature influence on print quality. To test the occurrence of the described errors, specific tests and materials are selected in the work. The result of this work is the recommended ambient temperature in the heated chamber for improved FDM printing.

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In recent years, research in the nanocomposites area of core-shell type increased significantly. The core-shell type nanoparticles with photoluminescence properties (PL) attract much attention from the scientific community. Are also of great interest nanoparticles that exhibit the upconversion energy, i.e. they absorbing low energy photons and emission high-energy photons. The present work has as objective nanocomposites synthesis of core-shell type, with CaTiO3 matrix (CT) and doped with rare earth ions Er3+ and Yb3+ in a variety composition and variations, to analysis the photoluminescent properties. The nanoparticles of the core and shell were obtained by the Method of Polymeric Precursors. The samples were characterized by X-ray diffraction (XRD) for structural characterization, and it was found that All samples presented the perovskite structure of the orthorhombic type. The characterization by Transmission Electron Microscopy (TEM) failed to demonstrate the formation of core-shell, requiring analysis by Energy Dispersive X-ray (EDX), which showed the presence of rare earth Er3+ and Yb3+ in the different layers. The UV-Vis gap allowed the calculation of the shell and core samples. The PL emission results were used to relate the thickness of the shell and the intensity of the emission. On the other hand, to study the upconversion energy, core materials showed a higher intensity than in the core-shell; the best intensity in the core-shell was found with doping the core with Yb3+ and Yb3+ with shell and Er3+ suggesting the transfer of energy between the layers.
Nos últimos anos, pesquisas na área de nanocompósitos do tipo core-shell cresceram significativamente. Atualmente nanopartículas do tipo core-shell com propriedades fotoluminescente (FL) atraem muita atenção da comunidade científica. Também são de grande interesse nanopartículas que apresentam a conversão ascendente de energia, ou seja, absorção de fótons de baixa energia e emissão de fótons de alta energia. O presente trabalho teve como objetivo a síntese de nanocompósitos do tipo core-shell, com a matriz CaTiO3 (CT) e dopagem com os íons terras raras Er3+ e Yb3+ nas mais variadas composições, para análise da propriedade fotoluminescente. As nanopartículas do core e do shell foram obtidas pelo Métodos dos Precursores Poliméricos. As amostras foram caracterizadas por Difração de Raios X (DRX) para caracterização estrutural, e foi constatada que todas as amostras apresentaram a estrutura perovsquita do tipo ortorrômbica. A caracterização por Microscopia Eletrônica de Transmissão (MET) não foi conclusiva quanto a formação do core-shell, sendo necessária a análise por Energia Dispersiva de Raios X (EDX), na qual verificou-se a presença das terras raras Er3+ e Yb3+ nas diferentes camadas. A espectroscopia de UV-Vis permitiu o cálculo do gap para as amostras core e shell. Os resultados de emissão FL foram utilizados para relacionar a espessura do shell e a intensidade da emissão. Por outro lado, ao estudar a conversão ascendente de energia, os materiais core apresentaram maior intensidade do que no core-shell; a melhor intensidade no core-shell foi verificada com a dopagem do core com Yb3+ e do shell com Yb3+ e Er3+, sugerindo a transferência de energia entre as camadas.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
We report the investigation of structural, optical and electrical properties of the MgxPb(1- x)TiO3 ceramic system produced by mechanosynthesis. The solid state reaction manufacturing method has been proved to be an efficient alternative to manufacture this type of material. By using Raman spectroscopy techniques it was possible observe the effects induced by pressure, from 0 up to 14 GPa, and by temperature from 10 up to 723 K for the samples with x ranging from 0.2 to 1.0. Complementary characterization techniques were also used, including X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Optical Absorption Spectroscopy and Electrical Impedance. XRD enabled the study of structural changes related to the increase in Mg concentrations. Raman analysis allowed the study of vibrational modes, in particular the transversely optical mode E(1TO) of lower frequency in order to characterize the phase transition from tetragonal-ferroelectric to cubic-paraelectric phases. From these results it was possible to construct a phase diagram that relates Mg concentration, temperature and hydrostatic pressure, yielding determine critical temperature (Tc) and critical pressure (Pc) in which phase transition occurs for each sample. Permittivity dielectric measurements were performed for each material, through which it was possible to compare the effects of Mg ratios in the modification of the values of these properties. Finally, a study of optical absorption as a function of Mg concentration was conducted, evidencing changes in gap energies related to the increase of Mg incorporation. The lowest values, 2.86 and 2.9 eV correspond to samples with concentrations of 0.4 and 0.2, respectively. Thus, from a technological point of view, these characteristics are interesting for applications in devices operating in the microwave region.
Neste trabalho foram investigados os efeitos estruturais, ópticos e elétricos do sistema cerâmico MgxPb(1-x)TiO3 produzido por mecano-síntese. O método de fabricação de reação de estado sólido mostrou-se uma alternativa eficiente de fabricação do material. Utilizandose de técnicas de espectroscopia Raman, foram observados os efeitos da pressão, de 0 a 14 GPa, e temperatura, de 10 a 723 K, para as amostras com x variando de 0,2 a 1,0. Também foram usadas técnicas complementares de caracterização entre elas a Difração de Raio-X (DRX), Microscopia Eletrônica de Varredura (MEV), Absorção Óptica e de Espectroscopia de Impedância Elétrica. A técnica de DRX possibilitou o estudo da alteração estrutural relacionada ao aumento das concentrações de Mg. As análises Raman permitiram o estudo dos modos vibracionais, em especial o modo transversal óptico E(1TO) de mais baixa frequência, a fim de caracterizar a transição de fase, da fase tetragonal ferroelétrica para a cúbica paraelétrica. A partir desses resultados foi possível construir um diagrama de fase relativo à concentração de Mg, com a temperatura e pressão hidrostática, obtendo-se temperatura crítica (Tc) e pressão crítica (Pc) nas quais ocorrem transição de fase para cada amostra. Foram realizadas medidas de permissividades dielétricas para cada material, por meio das quais foi possível a comparação dos efeitos das proporções Mg na alteração dos valores dessas propriedades. Por fim, foi realizado um estudo de absorção óptica em função da concentração de Mg, onde mostrou-se que há alteração do gap relacionada ao aumento da concentração de Mg. Os valores mais baixos, 2,86 e 2,9 eV correspondem a amostras com concentração de 0,4 e 0,2, respectivamente. Assim, do ponto de vista tecnológico, as características encontradas mostram-se úteis para dispositivos que operam na região das micro-ondas.

In this diploma thesis we are discussing about using 3D bioprinting in tissue engineering. We are discribing using biomaterials for construction scaffolder and aplication stem cells in 3D bioprinting. Last section of theoretical part deals with very often used techniques of 3D bioprinting and we are focused on extrusion technique. In the practical part we propose a method for print vasculars structures. We realized prototype of print head, her design and 3D printing of individual parts. To mechanical part we create a control system for printing control. At the end we visualize the organization of the cells using program modules.

The master thesis describes the design and digital commissioning of a robotic production system for 3D concrete printing. The theoretical part of the thesis includes an analysis of the current state of knowledge in the field of 3D printing in industrial automation. It also includes a detailed system analysis of the problem, in which the requirements and elements of the production system are specified. In the applied part of the thesis, a 3D model of the workplace was created and a simulation of the entire production process and digital commissioning of the system were performed using the ABB RobotStudio software. The output of the of the application part of the thesis is the design is the design of the workplace with a debugged control program ready for use in real operation.

This diploma thesis deals with a design and manufacture of an active print head used for 3D printing of concrete mixtures. The aim is to ensure functional parameters of the print head at a minimal mass. Extrusion of the material from the print head is ensured by a screw conveyor, shaping of the material is carry out by a rotatably mounted nozzle provided with trowels. The dimensioning of the main elements of the print head is based on the parameters measured during tests with the older version of the print head and on the FEM analysis. The print head was manufactured and is able to extrude concrete mixture with an admixture of aggregate (fraction 4–8 mm) at a rate of 0,5–2 m3•h-1. The weight of the print head is 16.4 kg, which is 30 percent less than an older print head weighed. The manufactured print head was tested during the printing of a real object and met all the required parameters. The print head is ready for implementation in a machine providing large-scale printing of parts in the construction industry.

The thesis deals with the determination of mechanical properties of materials used for 3D printing (ABS, nylon and PLA). Standardized samples produced using a 3D printer using the Fused Deposition Modeling method were subsequently used for mechanical testing. The work is also extended to determine the mechanical properties of samples made by Soft Tooling. For the production of Soft Tooling samples, polyurethane resins SG 2000 and SG 145 were used. Individual materials were analyzed by mechanical tests (tensile test and hardness test). Surface integrity parameters have also been determined for 3D-printed materials. Parameters were selected from the individual tests (tensile strength, modulus of elasticity) ductility and hardness), which were subsequently statistically processed. The work is concluded by evaluating the results obtained, which were compared with the values given in material sheets.

The diploma thesis is focused on 3D printing of composites parts. Thesis deals with methods of additive manufacturing and describes principle of selected 3D printing technologies. In addition to additive technologies, the theoretical part presents an overview of composite materials and methods of composite production. Then there are four concepts that lead to 3D printing of continuous fiber reinforced composites components. The final concept is selected according to multi-criteria analysis and then designed. Designed extruder allows 3D printing of composite materials. The principle of the function consists of fiber impregnation by matrix inside the heat chamber and then deposition of composite on printing platform. The extruder also consist of fiber cutting mechanism. The extruder's ability is verified by the experiment.

Inglés TI3 es un curso de especialidad centrado en aprendizaje por competencias con enfoque en necesidades profesionales de un Traductor. El curso trabaja las habilidades de comprensión auditiva, producción oral, así como habilidades de comprensión lectora y producción escrita en el idioma inglés al nivel B2 según Marco Común Europeo de Referencias para Segundas Lenguas. El traductor interprete es una persona clave en un mundo globalizado en el que el mercado económico mundial se encuentra en crecimiento constante y necesita de una comunicación intercultural efectiva para abordar problemáticas, crear acuerdos e implementar soluciones de manera inmediata. Esto hace al traductor-interprete una persona clave para que su país se desarrolle de manera exitosa. Así, el curso busca brindar al futuro traductor-interprete una herramienta fundamental para enfrentar los retos en su campo profesional con eficiencia. El curso de Inglés TI3 desarrolla las competencias generales de comunicación oral y escrita y la competencia específica de segundas lenguas todas al nivel 3 y tiene como prerrequisito el curso de de Ingles TI2 o haber rendido la Prueba de Definición de Nivel de Inglés (PDN) de la carrera.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Semiconductors materials are largely employed on development of innumerous optical and electronic due to their electronic, optical, ferroelectric and structural properties. Among the semiconductors materials stand out the zinc oxide (ZnO) and the barium titanate (BaTiO3) once shows excellent properties allied to low cost to obtaining. The ZnO is a simple oxide used in technology and largely investigated as an alternative to replace high cost material on development of electronic devices. Similarly, the BaTiO3 has perovskite crystalline structure whose properties present great technological interest. This work evaluated the effect of Ba presence on wurtzite structure and the influence of Zn atoms on tetragonal BaTiO3 properties. The obtained results indicates that the Ba atoms changes drastically the band structure of ZnO, resulting in the decrease of band gap for low quantities and the semiconductor type modification for doping above 25 %. The insertion of such atoms in wurtzite also causes the improvement of ferroelectric properties and the increase of unit cell lattice parameters. In case of Zn-doped BaTiO3, the doping process reduces radically de band gap and the ferroelectric properties regarding to pure material. Likewise, the semiconductor type is also modified by the Zn atoms presence. Based on obtained results for both crystalline systems, was proposed their employed in formation of p-n heterojunction. The heterostructure was evaluated through of four models. The obtained results for each one of these models were used to describe the interface region of ZnO/BaTiO3 heterojunction, proving that the atoms intercalation occurs and is responsible for heterostructure properties. Such properties present this heterostructure as a potential alternative for development of electronic devices, mainly the development of memory devices. The obtained heterostructure requires a low amount energy to electronic conduction process and shows high compatibility between the structure of heterojunction and the SiO2 substrate which is used in development of such devices.
Materiais semicondutores são amplamente empregados no desenvolvimento de vários dispositivos ópticos e eletrônicos variados devido às suas propriedades eletrônicas, ópticas, ferroelétricas e estruturais. Dentre os materiais semicondutores, destacam-se o óxido de zinco (ZnO) e o Titanato de Bário (BaTiO3) uma vez que apresentam excelentes propriedades aliadas ao baixo custo de síntese. O ZnO é um óxido simples amplamente empregado na tecnologia e largamente investigado como uma alternativa para substituição de materiais de custo elevado no desenvolvimento de dispositivos eletrônicos. Por sua vez, o BaTiO3 é um material de estrutura cristalina perovskita cujas propriedades são de grande interesse tecnológico. No presente trabalho avaliou-se o efeito da presença de átomos de Ba na estrutura wurtzita do ZnO e a influência dos átomos de Zn sobre as propriedades do BaTiO3 tetragonal. Os resultados indicaram que os átomos de bário alteram drasticamente a estrutura de bandas do ZnO, resultando na diminuição do band gap para pequenas quantidades e a modificação do tipo de semicondutor para dopagens superiores a 25%. A inserção de tais átomos na estrutura wurtzita também é responsável pelo aprimoramento das propriedades ferroelétricas do material, bem como pelo aumento dos parâmetros de rede da célula unitária. No caso da estrutura do BaTiO3 dopada com Zn observou-se a redução drástica do band gap para o material e a modificação do caráter semicondutor do material; entretanto, ocorreu a redução das propriedades ferroelétricas em relação ao BaTiO3 puro. Com base nos resultados obtidos para ambos os sistemas cristalinos, propôs-se a sua utilização para formação de uma heterojunção do tipo p-n. A heteroestrutura foi avaliada por meio de quatro modelos diferentes. Os resultados obtidos para cada um destes modelos foram utilizados para descrição da estrutura eletrônica da região de interface da heterojunção, comprovando que a intercalação de átomos na interface é observada e mostra-se responsável pelas propriedades observadas para a heteroestrutura. Tais propriedades apontam a heterojunção ZnO/BaTiO3 como uma alternativa em potencial para aplicação no desenvolvimento de dispositivos eletrônicos e, principalmente, no desenvolvimento de dispositivos de armazenamento de dados, devido a diminuição de energia necessária para condução eletrônica.

The goal of this diploma thesis is the design and implementation of an application for generating and printing address labels in the SAP system. The work also explains the basic concepts of the SAP system and describes the technologies for creating print forms as SAP Adobe Form and SAP SmartForm. Lastly, it describes the solution of printing 1D and 2D barcodes and setting up the communication between the SAP system and the printer. The result of this work is an analysis of form creation, subsequent design of a solution for generating forms as address label, sheet of 21 address labels, Czech Post delivery notes, Czech Post delivery sheet and its implementation in the SAP system. The conclusion of the work is testing the created solution and proposing future improvements.

This diploma thesis deals with the solution 3D printing by KUKA robotic arm without realization of supporting structures. The 6-axis KUKA KR 60HA robotic arm allows adjusting 3D printing strategies compared to classical 3D printing concept. The first part of the diploma thesis is about the identification of the current state of knowledge, especially the state of the experimental device for the robotic 3D print. To improve quality of the printed is necessary to modify the printing head and develop the suitable calibration principle. Special printing strategies were designed to rearch the 3D printing overhead volumes without creating support structure. A special alghoritm in the Grasshopper evnironment was developed for generating 3D print trajectory on the body surface. For the quality improvement it is necessary to optimize the process parameters. The final step is experimental 3D printing with the evaluation of surface dimensions, geometric precision and layer coherence in various printing strategies.

Mestrado em Ciência e Engenharia de Materiais
Dielectric, piezoelectric and ferroelectric thin films have been in the past years significantly studied because of their technological interest in a wide range of applications in the microelectronics industry. Among the several ferroelectric materials, compositions within the solid solution between the ferroelectric BaTiO3 and the quantum paraelectric SrTiO3 (Ba1-xSrx)TiO3 (BST), possess high dielectric constant and relatively low loss over a wide frequency range (till >1 GHz), low-leakage current density, a large electric field dielectric tunability and a composition dependent Curie temperature. These properties make BST thin films attractive for high density dynamic random access memories (DRAMs), and low cost agile microwave circuits, such as phase shifters, tunable filters, tunable matching network and high tuning frequency range voltage controlled oscillators. Moreover BST is a lead free perovskite making it an ideal material from the environmental point of view. These applications require the growth of high quality BST thin films, in addition to fundamental understanding of their structural and dielectric properties, which often diverge from those in equivalent bulk material. The high temperatures required for the crystallization of the perovskite BST films are not compatible with Si based large scale integrated circuits. SiO2 and/or metal silicides formation occurs when BST is deposited on silicon at temperatures above 700ºC. An underlying silicide layer reduces materials high dielectric permittivity, since silicide has lower permittivity than the perovskite oxide, reducing the film effective capacitance. At these high temperatures recrystallization of the electrode layer beneath the film (e.g. platinum layer) may occur, which can lead to hillock formation and electrical shorting of BST films. Moreover, thermal stresses generated at high temperatures might affect the long-term reliability of the device. Hence the improvement and optimization of the processing conditions of BST thin films as well as the development of low temperature processes for the fabrication of BST films are still a key aspect from the technologic point of view. Additionally, a low annealing temperature is also essential when metallic or glass substrates are required. The present master thesis addresses the investigation on the preparation of BST thin films by sol gel at temperatures lower than 700ºC. Sol-gel derived (Ba0.8Sr0.2)TiO3 thin films with improved dielectric properties were prepared at 600°C, on Pt/TiO2/SiO2/Si substrate through the use of diphasic precursor sols. BST nanometric powders were dispersed in the amorphous BST precursor sol to prepare the diphasic precursor sol and (Ba0.8Sr0.2)TiO3 thin films without and with 1 mol%, 5 mol% and 10 mol% (Ba0.8Sr0.2)TiO3 seeds were fabricated. The role of seeds was investigated and analyzed on the crystalline phase evolution, microstructure development and electrical properties of BST thin films. The improvement on the characteristics of seeded BST films when compared with unseeded films was highlighted by a comprehensive structural, microstructural and electric characterization of the films. It was shown that using perovskite BST nanopowders as seeds results in the crystallization of a single perovskite phase in BST films either at lower temperatures or at shorter annealing time when compared with the preparation of identical films without seeds. The presence of nano sized BST seeds in the film precursor sol lowers the barrier for BST nucleation and results in a high density of small crystallites in the film. XRD analysis showed that the temperature at which the perovskite phase is formed (or identified) was decreased from 650ºC to 550ºC when BST seeds were used in the precursor sols and the temperature at which the pure perovskite phase is obtained was decreased from 700ºC to 600ºC. The seeded BST films exhibit enhanced crystllization kinetics and the overall activation energy for the perovskite crystllization was reduced from 189 kJ/mol for the unseeded film to 86 kJ/mol for 1 mol% seeded BST film and to 80 kJ/mol for 5 mol% seeded film. Scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) were employed to characterize the influence of seeds on the crystallinity, structure, microstructure, morphology and interface between BST thin films and the substrate. Both SEM and AFM surface morphology results showed that the grains of seeded films were smaller, more homogeneously distributed than unseeded ones. The surface roughness of BST films measured by AFM was decreased by the presence of BST nano seeds. TEM analysis clearly revealed that the crystallinity of BST films was enhanced with the presence of BST seeds under the same annealing conditions. The dielectric properties of BST thin films, including permittivity, loss tangent, tunability of the dielectric constant were evaluated and discussed as a function of seeds content. The dielectric constant of unseeded films annealed at 600ºC for 30 hours in oxygen were improved by the addition of 5 mol% seeds from ~300 to 400 at 1kHz, respectively. Simultaneously, the dissipation factors were decreased by the presence of 5 mol% seeds from ~0.1 to 0.07 at 1 kHz, from 0.07 to 0.01 at 1 MHz, respectively. The presence of 5 mol% seeds improved the tunability of BST films and an increment from 52% to 65% at 6 V was observed for unseeded and 5 mol% seeded BST thin films annealed at 600ºC for 30 hours in oxygen. The leakage current density of BST films with 5 mol% seeds heat treated at 600ºC for 30 hours in oxygen is 0.95×10-7 A/cm2 up to the applied voltage of 2.33 V (97 kV/cm), which was improved when compared with 0.88× 10-7 A/cm2 up to 2.02 V (84 kV/cm) measured for BST films without seeds. The value of the leakage current of both unseeded and 5 mol% seeded films meet the requirements for G-Byte DRAMs. Identically to the rest of the electrical properties, the polarization versus electric field (P-E) hysteresis was improved by the introduction of seeds. The remnant polarization Pr of BST films with 5 mol% seeds was 3.55 μC/cm2 with a coercive field of 75 kV/cm, which was considerably enhanced when compared with 1.8 μC/cm2 for BST films without seeds with a coercive field of 50 kV/cm. Corroborating the above results, piezo force microscopy (PFM) of BST seeded and non seeded thin films demonstrated the improved ferroelectric properties of BST films prepared with nanometric seeds.
Filmes finos dieléctricos, piezoeléctricos e ferroeléctricos têm sido muito estudados no passado recente, por causa do interesse tecnológico relacionado com a gama alargada de aplicações destes materiais na indústria microelectrónica. De entre os vários materiais ferroeléctricos, as composições pertencentes à solução sólida composta pelo ferroeléctrico BaTiO3 e o quantum paraléctrico SrTiO3, (Ba1-xSrx)TiO3 (BST), possuem constantes dieléctricas elevadas e baixas perdas dieléctricas até frequência elevadas (>1 GHz), baixas densidade de correntes de fuga, elevada sintonabilidade da permitividade dieléctrica com o campo eléctrico e temperatura de Curie dependente da composição. Estas propriedades tornam os filmes finos de BST atractivos para dispositivos de memórias dinâmicas de acesso aleatório DRAMs, e de circuitos sintonizáveis às frequências das microondas (phase shifters, tunable filters, tunable matching network and high tuning frequency range voltage controlled oscillators). Por outro lado BST é um material livre de chumbo o que o torna ideal do ponto de vista ambiental para estas aplicações. As aplicações acima mencionadas requerem o fabrico de filmes finos de BST de elevada qualidade, juntamente com o entendimento das relações entre a sua estrutura e propriedades, que muitas vezes divergem das propriedades apresentadas pelos materiais equivalentes na forma de monolitos. As elevadas temperaturas necessárias para a cristalização de fase de perovesquite em filmes finos de BST não é compatível com a integração em larga escala em circuitos à base de silício. A formação de SiO2 e ou silicietos metálicos ocorre quando BST é depositado sobre silício a temperaturas elevadas acima de 700ºC. Camadas subjacentes de silicietos reduzem a elevada permitividade dieléctrica relativa do material, já que estes silicietos têm permitividade dieléctrica relativa inferior à do óxido perovesquítico. A estas temperaturas elevadas pode ocorrer a recristalização do eléctrodo colocado sob o filme (por exemplo platina), o que origina o aparecimento de curto circuitos nos filmes de BST. Mais ainda, as tensões térmicas geradas às temperaturas elevadas podem afectar a longo prazo o desempenho e a fiabilidade do dispositivo. Assim o melhoramento e optimização das condições de fabrico de filmes finos de BST, bem como o desenvolvimento de metodologias de processamento destes filmes a temperaturas mais baixas continua a ser um aspecto chave do ponto de vista tecnológico e de comercialização destes materiais. Acrescente-se que um processamento a baixas temperaturas é ainda essencial quando é necessária a utilização de substratos metálicos ou de vidro. A presente tese descreve a investigação conduzida na preparação de filmes finos de BST por sol gel a temperaturas inferiores a 700ºC. Filmes finos de (Ba0.8Sr0.2)TiO3 (BST80/20) com propriedades melhoradas foram preparados por sol gel a 600°C, sobre substratos de Pt/TiO2/SiO2/Si, através da utilização de soles precursores difásicos. Partículas nanométricas de BST foram dispersas em soles precursores de BST e filmes finos de BST80/20 sem e com 1 mol%, 5 mol% and 10 mol% de sementes de BST foram fabricados. O papel das sementes foi investigado e analisado na formação de fases, desenvolvimento microestrutural e propriedades dieléctricas dos filmes de BST. O estudo sistemático da estrutura, microestrutura e propriedades evidenciou as melhorias das características dos filmes de BST sementados. Foi mostrado que a utilização de partículas nanométricas de BST como sementes resulta na cristalização da fase pura de perovesquite nos filmes de BST ou a temperaturas mais baixas ou para tempos mais curtos. A presença de nanopartículas de BST nos soles precursores dos filmes baixa a barreira enérgica para a nucleação da fase de perovesquite de BST e origina no filme uma densidade elevada de pequenas cristalites. As análise de difracção de raios X mostraram que a temperatura à qual a fase de perovesquite se forma decresceu de 650ºC para 550ºC quando se utilizam sementes de BST nos soles precursores e que a temperatura à qual a fase pura de perovesquite é obtida decresceu de 700ºC para 600ºC. Os filmes sementados de BST exibem uma cinética de cristalização optimizada e a energia de activação para a cristalização da fase de perovesquite foi reduzida de 189 kJ/mol para os filmes não sementados para 86 kJ/mol e 80 kJ/mol para os filmes sementados com 1 mol% e 5 mol% de sementes, respectivamente. Para caracterizar a influência das sementes na estrutura, grau de cristalinidade, microestrutura, morfologia e interface filme / substrato foram utilizadas as técnicas de microscopia electrónica de varrimento (SEM), microscopia de força atómica (AFM) e microscopia electrónica de transmissão (TEM). Os resultados da morfologia da superfície dos filmes obtidos quer por SEM quer por AFM mostraram que os grãos dos filmes sementados são claramente menores e apresentam uma distribuição mais homogénea, relativamente aos filmes não sementados. A rugosidade da superfície dos filmes quantificada por AFM decresceu por adição das sementes. As análises de TEM revelaram que a cristalinidade dos filmes sementados é superior relativamente aos filmes não sementados, para filmes preparados em idênticas condições. As propriedades dieléctricas dos filmes finos de BST, que incluem a permitividade dieléctrica relativa, a perda dieléctrica, a sintonabilidade da permitividade dieléctrica foram avaliadas e analisadas em função do teor de sementes. A permitividade dieléctrica relativa de filmes não sementados e tratados termicamente a 600ºC durante 30 horas em oxigénio variou de ~300 para 400 a 1 kHz, pela adição de 5 mol% de sementes. Simultaneamente a perda dieléctrica decresceu para os filmes com 5 mol% de sementes de ~0.1 para 0.07 a 1 kHz e de 0.07 para 0.01 a 1 MHz. A presença de sementes melhorou a sintonabilidade dos filmes de BST, verificando-se um incremento de 52% para 65% a 6 V para os filmes sementados com 5 mol% de sementes em relação aos filmes não sementados ambos tratados termicamente a 600ºC por 30 horas em oxigénio. A densidade de corrente de fuga variou de 0.88 × 10-7 A/cm2 até uma voltagem aplicada de 2.02 V (84 kV/cm) para os filmes de BST não sementados e tratados termicamente a 600ºC durante 30 horas em oxigénio, para 0.95 ×10-7 A/cm2 até uma voltagem aplicada de 2.33 V (97 kV/cm) para filmes de BST com 5 mol% de sementes preparados nas mesmas condições. Os valores de densidade de corrente de fuga dos filmes sementados cumprem os requisitos estipulados por exemplo para as memórias dinâmicas de acesso aleatório (DRAM) de capacidade da ordem de G-Bytes. De forma idêntica à restante caracterização eléctrica, a presença de sementes em filmes de BST melhorou sua a resposta histerética da variação da polarização com o campo (P-E). Foram determinados valores de polarização remanescente de 3.55 μC/cm2 com campos coercivos de 75 kV/cm para filmes com 5mol% de sementes, valores estes consideravelmente superiores aos valores determinados para filmes não sementados de 1.8 μC/cm2 e 50 kV/cm para a polarização remanescente e o campo coercivo, respectivamente. Suportando os resultados anteriores, a microscopia de força piezoeléctrica (PFM) demonstrou igualmente a melhoria das propriedades ferroléctricas dos filmes de BST preparados com sementes.

In the work is used the processing of metallic material by the method of Selective Laser Melting. The main objective is to verify and describe the influence of the individual process parameters entering the production process when processing the alloy Cu7.2Ni1.8Si1Cr with SLM. This alloy contains 90 % copper. The first theoretical part of the thesis describes so far processed copper alloys with a high content of copper using the method of Selective Laser Melting. The practical part then deals with the specification of the main process parameters, which are optimized in the next part of the work solution. On the basis of the information obtained experimental bodies have been created, which will be tested and analyzed in several steps. The work focuses on thin-walled samples, which have a perspective use in the creation of highefficiency heat exchangers. The main results that the work deals with are the relative density and mechanical properties of the material. Also, great emphasis is placed on the resulting surface quality

The presented thesis deals with FDM 3D printing method with emphasis on printing carbon fiber reinforced plastic (CFRP). The aim of this thesis is to engineer the FDM 3D printer designed for printing CFRP and to execute the experiment targeted on comparison of CFRP material properties against commonly used 3D printing plastics such as PLA, ABS, PET etc. The device designed in this work has printing area of 200 x 200 mm with maximum height of the object of 200 mm. The printing bed is heated and the whole device is enclosed. There are two kinds of experiments carried out within the thesis. The first one is focused on tensile strength and Young's modulus of selected materials, while the second experiment compares Charpy's impact strength of specimen with different infill percentage on two selected materials, PET and PET filled with chopped carbon fiber.

Designing a material for a particular application requires an atomistic understanding of its properties. Recent development in first principles methods and supercomputing speeds has enabled researchers to compute materials properties accurately. This has opened up a window for computational designing of materials for various applications such as optoelectronics, thermoelectrics, magnetic shape memory alloys etc. In this thesis, first principles methods have been utilized to understand the properties of various materials such as TiS2, TiS3, GeO2, Co3(MoTaAl) alloys, Ni2MnGa and graphene. This thesis has been organized as follows: • Chapter 1 introduces various functional materials and their application in the thermoelectric, optoelectronic, high temperature and magnetic shape memory. The microscopic understanding of materials properties such as structure, energetics, electronic structure, electronic transport, and lattice dynamics etc. can lead to novel ways of designing materials properties for various applications. • Chapter 2 describes the theoretical methodology adopted in this work. It gives a brief understanding of first principles based density functional theory (DFT) and various approximations to obtain accurate electronic properties. Methods employed for calculation of electronic and thermal transport are also discussed briefly. • In Chapter 3 we explore the tuning of the electronic structure of the transition metal dichalogenide TiS2. We show that by engineering its electronic structure, it transforms from a semimetal to a semiconductor under biaxial strain. The thermoelectrics study shows that a 3 fold enhancement in thermopower can be achieved by application of 5% biaxial strain. This enhancement is driven by a small bandgap opening of ∼0.15 eV, which increases its thermopower at the same time decreasing its lattice thermal conductivity indicating improvement in ZT. • In Chapter 4 we study the possibility of inherent stacking fault in bulk TiS3 and its effect on the electronic properties. We find that TiS3 can exist in AB′ and AB′′ geometries. The energy difference between two structures is about 0.011 eV/f.u. The electronic structure is independent of the stacking fault due to the weak vdW interaction between the layers. The calculated thermopower is 200 μV/K in the carrier concentration range of 1×1020 cm−3 - 5×1020 cm−3, which is comparable with other state of the art thermoelectric materials. The high thermopower and electrical conductivity in the carrier concentration range of 1×1020 cm−3 - 5×1020 cm−3 leads to a high power factor for both p- and n-type. Moreover, the power factor for p-type is three times higher than that of n-type carriers indicating that the thermoelectric performance for p-type will be much better than that of n-type. • Chapter 5 reveals the origin behind the large variation in the band gap (∼ 2 eV) of GeO2 calculated by standard DFT within LDA/GGA, which had remained unresolved. Using the many-body perturbation theory (GW approximation), we find that this large variation observed in literature is independent of the method used and depends strongly on the lattice parameter (volume strain). This strong dependence originates from a change in hybridization among O-p and Ge-(s and p) orbitals. • Chapter 6 deals with the structural stability of order intermetallic Co-based superalloys. We have shown that W free Co3Al order structure can be stabilized in L12 structure by addition of Mo and Ta atoms. The enthalpy of formation of L12 structure significantly becomes more negative compared to the DO19 structure by the addition of ≥ 4% of Ta atoms. This implies that the L12 structure of Co3(Al,Mo,Ta) structure is more stable compared to DO19. The lowering in the enthalpy of formation is found due to the formation of the pseudo gap and the decrease in the states at the pseudo gap with increasing Ta concentration. The stability of the L12 structure can be further improved by the addition of Ni and Ti atoms. • In Chapter 7, the lattice dynamics and electronic structure of X2YZ [where X = Ni, Fe, Co; Y = Mn; Z = Al, Ga, Ge, In, Sn, Sb] stoichiometry compounds are investigated. The lattice instability of X2MnZ depends on the position of the Fermi energy (EF ) with respect to the pseudo gap. The phonon mode softening along the Γ-K symmetry direction is observed for Ni2MnZ in the austenite phase since EF is located above the pseudo gap. This mode softening is mainly responsible for the MSM effect. On the other hand, Fe2MnZ and Co2MnZ [Z = Al, Ga, Ge, In, Sn, Sb] in the cubic phase do not show any phonon mode softening because EF lies in the vicinity of the pseudo gap or at the pseudo gap. Thus, alloying Fe or Co at the Ni site in Ni2Mn (Z = groups-IV and V) can tune the lattice modulation. In addition, the magnetic moments of Fe2Mn (Z = groups-IV and V) and Co2Mn (Z = groups-IV and V) are much higher than those of Ni2Mn (Z = groups-IV and V), indicating that the magnetic moments of Ni2MnZ can be enhanced. The calculated phonon dispersion with magnetic moment indicates that the phonon mode softening is sensitive to the change in the local magnetic moment of the atoms, thereby enabling tunability in the MSM effect. • In chapter 8, we show that the mono vacancy defects in graphene can be used as precursors to form novel clipped structures without explicit use of functional groups. These clipped structures can be transformed into one-dimensional (1D) double wall nanotubes (DWCNT) or multi-layered three dimensional (3D) structures. The clipped structures show good mechanical strength due to covalent bonding between multi-layers. Clipping also provides a unique way to simultaneously harness the conductivity of both walls of a double wall nanotube through covalently bonded scattering junctions. With additional conducting channels and improved mechanical stability, these clipped structures can lead to a myriad of applications in novel devices. • Chapter 9 summarizes and concludes the work presented in this thesis.

碩士
國立臺南大學
經營與管理學系科技管理碩士在職專班
103
Nowadays, with the advent of information age and the rapid change of market environment, enterprises are facing unprecedented competition. In order to save operation cost and integrate external resources, many companies start to try outsourcing. However, if a company wants to approach the sustainable development, employee will be the key to make it more competitive, therefore, employment pattern is an important issue for the organizational innovation performance. This research will be verified whether the human capital might do the positive effect on the organizational innovation performance, and discuss their relationships with employment pattern. In this study, we sample Third Industrial Innovation Survey in Taiwan Area (TIS3 Database), and combined with Genetic Algorithms is used to verify the hypothesis. The results show that: human capital exists the positive effects on the organizational innovation performance first. Then, a positive relationship between internal development employment pattern and organizational innovation performance is supported by manufacturing and service industries, but not financial industry. Third, a negative relationship between contracting employment pattern and organizational innovation performance is observed on the manufacturing industry, but not service and financial industries. According to the above results, this study proposes some useful suggestions on the managerial implications as well.

碩士
國立成功大學
資源工程學系碩博士班
95
With the raising of the environmental sense, some materials which contain harmful health elements and materials will be inhibited. For the piezoelectric materials, new lead-free piezoelectric materials with better electric properties will also be developed. (Bi0.5Na0.5)TiO3 is a excellent candidate system in lead-free piezoelectric materials system at present because of its outstanding advantage in free control atmosphere and no lead pollution. In this research, the Ba2+ and Sr2+ were both doped into this composition system via solid state reaction to synthesize (1-x)(Bi0.5Na0.5)TiO3 - x(Ba1-aSra)TiO3 solid solution system. When a is 0.05 and 0.3, the crystal structure and electric properties of the two system were studied in detail. According to the changes of the crystal structure and electric properties which resulted from the composition variation of x equal 0 to 0.12 in this research. The result show that：First, (1-x)(Bi0.5Na0.5)TiO3 - x(Ba1-aSra)TiO3 solid solution system could be synthesized successful in this research. And the relative density of sintered bulks of each composition could achieve 98% or over. Second, the phase transformation with composition variation of this system was showed in detail in this research. Besides, the cell parameters, cell volume, and theoretical density were also obtained after the Rietveld method calculation and get the displacement of atoms in the crystal structure. Third, the MPB could be calculated by tolerance factor and confirmed by the experiment result. The MPB region exists when a equal 0.05,x is 0.06 but a equal 0.3,x is 0.08. Fourth, presents the main factors which affect the dielectric properties after poling and piezoelectric coefficient are the modifiability of the displacement between cation and anion center in oxygen-octahedral structure and the existence of MPB.

碩士
國立成功大學
電機工程學系碩博士班
96
The microwave properties of x(Mg0.95Zn0.05)TiO3-(1-x)Na0.5La0.5TiO3 dielectric ceramic materials have been discussed in this paper.Using positive and negative temperature coefficients would achieve zero temperature coefficient of resonant frequency. Na0.8La0.5TiO3 has dielectric properties of ~122，Q × f value ~9800 and a positive value ~ 480 ppm/℃. (Mg0.95Zn0.05)TiO3 possesses high dielectric constant ( ~17)，high quality factor (Q × f ~260,000 at 9GHz) and negative value(-40 ppm/℃).By appropriately adjusting the x value in the x(Mg0.95Zn0.05)TiO3-(1-x)Na0.5La0.5TiO3 ceramic system, zero value can be achieved. The experiment results show that it has excellent dielectric properties(Q×f~103000(9GHz)， ~23.39， ~1.1ppm/oC) when x value equal to 0.88. Besides, we attempt to add different sintering aids B2O3 and CuO respectively and discuss the effects of the microwave properties by various amounts of sintered aids. 0.88(Mg0.95Zn0.05)TiO3-0.12Na0.5La0.5TiO3. Finally, we design and fabricate a band-pass filter using dual-mode meader loop resonators with 2GHz center frequency on FR4、Al2O3、88MZNLT substrate respectively. And we compared with the result of the simulation and measurement.

碩士
國立成功大學
電機工程學系碩博士班
95
The microwave dielectric properties and the microstructures of the x(Mg0.95Co0.05)TiO3-(1-x)(Ln0.5Na0.5)TiO3 ceramics were investigated(where Ln represents a lanthanide: La+3、Nd+3). (Ln0.5Na0.5)TiO3 ceramic has a high dielectric constant εr and a positive temperature coefficient of resonant frequency τf. On the other hand, (Mg0.95Co0.05)TiO3 ceramic has a high quality factor Q×f and a negative temperature coefficient of resonant frequency τf . The results show that zero τf value and excellent Q×f value and dielectric constant εr can be obtained by appropriately adjusting the x value. Finally, we add sintering aid of B2O3 to promote the material density and reduce the sintering temperature. The outcome reveals that the specimen of 0.88(Mg0.95Co0.05)TiO3-0.12(La0.5Na0.5)TiO3 with 0.5wt% B2O3 can be sintered at 1225oC and has the characteristics of εr~22.77、Q×f value~98200、and τf value~+1.83ppm/oC. Compare the material of 88MCLNT+0.5wt％B2O3 with pure material which is sintered at 1325oC, and the sintering temperature of the material of 88MCLNT+0.5wt％B2O3 was Conspicuously reduced. Otherwise, we fabricate a second order Butterworth hairpin filter using 0° feed structure on the substrates 88MCLNT+0.5wt％B2O3, FR4 and Al2O3 respectively to compare and verify that the material of 88MCLNT+0.5％B2O3 has stable temperature coefficient of resonant frequency τf, high dielectric constant εr, and excellent quality factor Q×f.

This thesis is devoted to Jozef Tiso. It deals with the time of his reign amd the subsequent evaluation of his goverment in slovak historiography. It comes partly from authors who directly collaborated with Jozef Tiso as well as from those who are against this person strongly determine the events between 1948 does not forget nor authors who have worked abroad and then in 1989 returned to Slovakia. It is also the current controversies about Jozef Tiso, which are still present among Slovak historians. A separate chapter is devoted to the Catholic Church and its attitude to Jozef Tiso.

碩士
國立交通大學
物理研究所
99
Applications of nanostructures in semiconductor industry in recent years has been towards the 22 nm manufacturing process, some materials properties of bulk and properties of nanowire are some differences, the study of nano-structural properties of these materials is an important issue. We study the basic properties and electrical transmission of TiSi nanowires, the most compounds of Ti and Si are low resistivity, high melting point and high antioxidant characteristics. The TiSi nanowires manufactured by Chiulab, Department of Applied Chemistry, National Chiao Tung University. It is the first successful production of TiSi. We used focused ion beam technology to produce nano-wire connection electrodes in two different deposition conditions, the measured two kinds of different electrical transport properties. I proved that FIB completely destroyed nanowires, and measured non-nanowire itself. We also use electron beam lithography to create electrodes confirms our inference.

This thesis describes current technologies for a manufacture of wooden pattern equipment. It deals with machines, constructions and materials. Moreover, this study concerns particular technologies of 3D printing and materials used for printing. Its practical part includes a manufacture and mechanical trials of standard samples produced by 3D technologies FDM. The aim is to optimize a manufacturing process of 3D printing of a particular sample. The optimization considers manufacturing time, material consumption and mechanical strength, i.e. impact strength. The results of this study are conclusions and proposals for pattern equipment manufacturers who use the 3D technology.

In der vorliegenden Arbeit wurden die Grenzflächeneigenschaften steuerbarer Kondensatoren auf Basis kathodenzerstäubter Bariumstrontiumtitanat (BST)-Dünnschichten, die als Schlüsselkomponenten zum Aufbau neuartiger passiver Hochfrequenzschaltungen und Systeme in moderner Mikrowellentechnik dienen, modifiziert und umfassend untersucht. Der zentrale Schwerpunkt dieser Arbeit liegt auf der Korrelation von Grenzflächen-, elektrischen und dielektrischen Eigenschaften. Zur Grenzflächenmodifizierung wurden hoch isolierende Aluminiumoxid-Zwischenschichten bzw. transparente leitfähige Zinn-dotierte Indiumoxid (ITO)-Elektroden eingesetzt. Die Untersuchung der Grenzflächenausbildung, d. h. der Bandanpassung und der Barrierenhöhe zwischen BST und Aluminiumoxid bzw. ITO, erfolgte mittels in situ Photoelektronenspektroskopie. Basierend auf einer Parallelplattenstruktur wurden die elektrischen und dielektrischen Eigenschaften der BST-Kondensatoren im Hinblick auf die durch die Grenzflächenmodifizierung veränderte Ladungsträgerinjektion charakterisiert. Ausgeprägte Strom-Spannungs-Charakteristiken wurden beobachtet und auf unterschiedliche Injektionsmechanismen zurückgeführt. Das dadurch gewonnene Verständnis über die Einflüsse der Grenzflächen wurde in dieser Arbeit für die Modifizierung bzw. Verbesserung der dielektrischen Eigenschaften ausgenutzt, zum Beispiel für die Erhöhung des Gütefaktors oder die Entwicklung neuer Funktionalitäten. Es konnte gezeigt werden, dass die elektronische Struktur der Materialien und deren Grenzflächen eine entscheidende Rolle für die Eigenschaften der Dünnschicht-Bauteile spielen.