O trabalho apresenta o estado-da-arte das fachadas-cortina executadas com placas de grês porcelanato, discutindo os principais parâmetros para a elaboração de projetos e produção desta tipologia de revestimentos. Acredita-se ser este um dos primeiros trabalhos acadêmicos elaborados no Brasil sobre o assunto, pretendendo-se contribuir quando da implantação desse sistema no país. Procura-se estabelecer os principais conceitos e definições sobre as fachadas-cortina e fachadas ventiladas, objetivando fundamentar a utilização desses termos que vêm sendo empregados sem precisão pelo meio técnico brasileiro. São abordadas as principais características e propriedades dos componentes, elementos construtivos e dispositivos empregados, como também os principais requisitos a serem considerados quando da elaboração do projeto. São destacadas as vantagens relativas desta tecnologia construtiva quando comparada aos revestimentos tradicionais aderidos, ressaltando-se sua importância como alternativa e potencialidades quando comercializado como um sistema de produção. / This report approaches the state-of-art of the porcelain tiles curtain wall. Both design and installations methods are discussed, including main features and properties of the components, elements and devices necessary. Main requirements considered to the design process are also take into consideration. It is believed that this study is one of the first academic studies developed in Brazil concerning this theme, and it is intended to contribute to the implementation of this system in the country. It aims at establishing the main concepts and the definitions on the curtain walls and ventilated facades. The prime objective is to base the correct use of these terms, since they have been used without accuracy by the Brazilian technicians. main features and properties of the components, elements and devices necessary. Main requirements considered to the design process are also take into consideration. Several advantages concerning this type of cladding are emphasized when compared with traditional coverings, standing out the comportance of the method as an interesting technology alternative.

O trabalho apresenta o estado-da-arte das fachadas-cortina executadas com placas de grês porcelanato, discutindo os principais parâmetros para a elaboração de projetos e produção desta tipologia de revestimentos. Acredita-se ser este um dos primeiros trabalhos acadêmicos elaborados no Brasil sobre o assunto, pretendendo-se contribuir quando da implantação desse sistema no país. Procura-se estabelecer os principais conceitos e definições sobre as fachadas-cortina e fachadas ventiladas, objetivando fundamentar a utilização desses termos que vêm sendo empregados sem precisão pelo meio técnico brasileiro. São abordadas as principais características e propriedades dos componentes, elementos construtivos e dispositivos empregados, como também os principais requisitos a serem considerados quando da elaboração do projeto. São destacadas as vantagens relativas desta tecnologia construtiva quando comparada aos revestimentos tradicionais aderidos, ressaltando-se sua importância como alternativa e potencialidades quando comercializado como um sistema de produção. / This report approaches the state-of-art of the porcelain tiles curtain wall. Both design and installations methods are discussed, including main features and properties of the components, elements and devices necessary. Main requirements considered to the design process are also take into consideration. It is believed that this study is one of the first academic studies developed in Brazil concerning this theme, and it is intended to contribute to the implementation of this system in the country. It aims at establishing the main concepts and the definitions on the curtain walls and ventilated facades. The prime objective is to base the correct use of these terms, since they have been used without accuracy by the Brazilian technicians. main features and properties of the components, elements and devices necessary. Main requirements considered to the design process are also take into consideration. Several advantages concerning this type of cladding are emphasized when compared with traditional coverings, standing out the comportance of the method as an interesting technology alternative.

The process of laser cladding consists of depositing successive layers of molten metallic powder to create a near-net shape. A high-power laser is used to melt incoming metallic powder, which forms a melt pool on the surface. As the latter moves beneath the laser, this newly created melt pool solidifies. By properly controlling the trajectory of deposition tracks, one can create a diverse range of shapes with varying complexities. However, the process is very sensitive to parameters, requiring constant attention from technicians. This lends itself perfectly to the addition of automatic controllers whereby supervision is minimal. <br /><br /> In this thesis, an optical sensor is developed to monitor the process zone. The sensor will output a measurement of the height of solidified clad, which in turn can be used by a controller to adjust this geometrical feature. The thesis is divided into three main parts, each contributing to the final algorithm. <br /><br /> First, in Chapter 3 an analysis is performed on the light irradiating from the interaction zone (or melt pool). It is stated that the dominating source of light is governed by blackbody radiation from this molten metal. This is confirmed by analyzing a series of images captured through a digital camera, where various narrow bandpass filters were utilized to selectively view a portion of the CCD-sensor's spectrum. This investigation also leads to the selection of bandpass filter such that a stable, relatively intense melt pool is captured through the digital camera's CCD-sensor. <br /><br /> Second, in Chapter 4 the captured images are taken through a pair of image processing techniques, outputting a series of coordinates representating the melt pool's boundary. The image is first analyzed to calculate an optimal threshold level based on the minimization of fuzzy entropy. With this threshold selected, the grayscale image is converted into black-and-white, where the white pixels represent the melt pool. After this step, the melt pool's boundary is extracted through an 8-connectivity border tracing algorithm. This technique outputs a series of coordinates (in pixels) as though one were traveling along the melt pool in a clockwise rotation. <br /><br /> Last, Chapter 5 analyzes these pixel coordinates to extract the melt pool's height. The coordinates are first transformed into real-world coordinates, by use of a perspective transformation. This transformation essentially yields the melt pool's shadow, as created by a light-source coincident with the camera. As a result, the melt pool's height is estimated based upon a right-angle triangle, where the camera's angle is known, and the projected coordinates represent the shadow length (triangle's base). <br /><br /> The result of applying this series of steps to the estimation of clad heights is found at the end of Chapter 5. Results varied dramatically, from 4% error to 393%. Although the errors are large at times, they are mainly caused by a bias in the estimate. That is, the dynamics of the true clad formation are very well predicted by the algorithm, however, shifting by a certain amount. This amount varies both with substrate velocity, and the clad's direction of travel, relative to the camera. A partial explanation is given such that the clad's height is offset from the laser center-point, which is a function of both these parameters. However, the specific relationship requires further experimentation.

The process of laser cladding consists of depositing successive layers of molten metallic powder to create a near-net shape. A high-power laser is used to melt incoming metallic powder, which forms a melt pool on the surface. As the latter moves beneath the laser, this newly created melt pool solidifies. By properly controlling the trajectory of deposition tracks, one can create a diverse range of shapes with varying complexities. However, the process is very sensitive to parameters, requiring constant attention from technicians. This lends itself perfectly to the addition of automatic controllers whereby supervision is minimal. <br /><br /> In this thesis, an optical sensor is developed to monitor the process zone. The sensor will output a measurement of the height of solidified clad, which in turn can be used by a controller to adjust this geometrical feature. The thesis is divided into three main parts, each contributing to the final algorithm. <br /><br /> First, in Chapter 3 an analysis is performed on the light irradiating from the interaction zone (or melt pool). It is stated that the dominating source of light is governed by blackbody radiation from this molten metal. This is confirmed by analyzing a series of images captured through a digital camera, where various narrow bandpass filters were utilized to selectively view a portion of the CCD-sensor's spectrum. This investigation also leads to the selection of bandpass filter such that a stable, relatively intense melt pool is captured through the digital camera's CCD-sensor. <br /><br /> Second, in Chapter 4 the captured images are taken through a pair of image processing techniques, outputting a series of coordinates representating the melt pool's boundary. The image is first analyzed to calculate an optimal threshold level based on the minimization of fuzzy entropy. With this threshold selected, the grayscale image is converted into black-and-white, where the white pixels represent the melt pool. After this step, the melt pool's boundary is extracted through an 8-connectivity border tracing algorithm. This technique outputs a series of coordinates (in pixels) as though one were traveling along the melt pool in a clockwise rotation. <br /><br /> Last, Chapter 5 analyzes these pixel coordinates to extract the melt pool's height. The coordinates are first transformed into real-world coordinates, by use of a perspective transformation. This transformation essentially yields the melt pool's shadow, as created by a light-source coincident with the camera. As a result, the melt pool's height is estimated based upon a right-angle triangle, where the camera's angle is known, and the projected coordinates represent the shadow length (triangle's base). <br /><br /> The result of applying this series of steps to the estimation of clad heights is found at the end of Chapter 5. Results varied dramatically, from 4% error to 393%. Although the errors are large at times, they are mainly caused by a bias in the estimate. That is, the dynamics of the true clad formation are very well predicted by the algorithm, however, shifting by a certain amount. This amount varies both with substrate velocity, and the clad's direction of travel, relative to the camera. A partial explanation is given such that the clad's height is offset from the laser center-point, which is a function of both these parameters. However, the specific relationship requires further experimentation.

In this study, we study the polarization dependence, gain property, and amplified spontaneous emission in Cr4+: YAG crystal fibers. Cr4+: YAG crystal has an ultra-wide bandwidth of 300 nm. Cr4+: YAG crystal fibers fabricated through laser heated pedestal growth technique are suitable for the applications of fiber amplifiers, fiber lasers, and broadband light sources. The experiment results showed that the polarization-dependent loss has a severe variation as the optical wavelength change. The maximum polarization-dependent loss was up to 18 dB. The main reason of such a large polarization-dependent loss is the combination of multimode interference and the birefringence induced by the non-uniformity of optical waveguide structure and residue strain in Cr4+: YAG crystal fibers. Thus, the results of polarization-dependent loss can be used as a feedback parameter to improve the fabrication process. In the experiment of gain property, bi-directional pump and double-pass transmission scheme was adopted and a 0.2 dB net gain was obtained for the first time at signal wavelength of 1400 nm, pumping wavelength of 1060 nm, and total pumping power of 2.8 W. It shows that Cr4+: YAG crystal fiber has potential to be developed as a broadband fiber amplifier. In the measurement of amplified spontaneous emission spectrum, a wide bandwidth of amplified spontaneous emission of 300 nm with total power of 50 £gWwas obtained at 0.2W pumping power condition. The coupling efficiencies from amplified spontaneous emission to single mode fibers and multimode fibers were 1.5 % and 9.9 %, respectively. This result reveals that it has potential to be developed as a broadband light source. To improve the optical properties of Cr4+: YAG crystal fiber in the future, improving the uniformity of optical fiber waveguide and reducing the residue strain in Cr4+: YAG crystal fiber may suppress the polarization-dependent loss; increasing the fiber length, decreasing the mode number, and employing a cladding pump technique with a well-distributed pump power in the crystal fiber to alleviate the excited state absorption may raise the gain performance and the amplified spontaneous emission power.

One of the communities in the path of Hurricane Charley as it came ashore August 13, 2004, was Punta Gorda, recording gusts up to 145 mph. This project utilizes aerial photos taken approximately 10 days after the storm battered the area, using a digital photography program. Focusing on the one-story residential structures (houses) of the Punta Gorda area, a damage assessment could be made of the area’s homes, and how they stood up to the storm. This study focused further on homes built after major changes to the local/state building codes went into effect (starting in 1996) after the devastation left in south Florida by Hurricane Andrew in 1992. After selecting approximately 20 damaged houses, damaged from wind loading only, an analysis of these houses (or types of houses) could then be undertaken complying with the most current building/wind codes used at the time of Charley’s landfall. Furthermore, by looking at the pictures, and using reports outlining the types of damage seen from the storm, the building/wind codes could then be checked for their effectiveness. After performing a wind loading analysis on houses similar to those seen in the selected pictures, and using the wind code provisions of ASCE 7-98, calculations show a substantial increase in local wind pressure to various zones of the roof. High pressure zones of the roof included the ridges of the gable and hipped style roofs, as well as the corners and the edges. More emphasis needs to be placed on the installation of the clay tiles (mandated by certain deed-restricted subdivisions of Punta Gorda). If the tiles are ripped off from the wind, then the roof sheathing becomes exposed to the environment, and if this becomes damaged, rain leaking down into the interior of the house would cause additional damage.

M. Tech. Metallurgical Engineering / Titanium alloys exhibit poor tribological characteristic which include abrasion resistance, metal to metal wear resistance and solid particle erosion and cavitation due to low surface hardness and high coefficient of friction. These poor properties have limited the application of titanium alloys as engineering tribological components, tools and parts that operate in severe wear and friction conditions. Laser processing defects such as pores, cracks and segregation pose a huge threat to the quality and the microstructure of the deposited layer. Defects caused by the parameters lead to severe wear and corrosion occurrence, hence, precise control of the parameters are crucial and it depends on the properties of the material used. It is postulated that Nickel Titanium (NiTi) is a promising candidate as reinforcement matrix material for wear resistant alloy. The wear resistance would be further enhanced if NiTi is in-situ incorporated onto titanium matrix by laser cladding to yield hard intermetallic phases. The main goal of the study is to develop corrosive-wear resistant thin surface coatings on Ti-6Al-4V alloy for automotive and aerospace applications by depositing Titanium and Nickel elemental powders to form in-situ NiTi intermetallic using laser cladding technique.

Fuel cladding is one of the most critical components of nuclear reactors; so it is important to improve our understanding of various properties and behaviors of the cladding under different conditions approximating the nuclear reactor environment. Moreover, the efficiency of energy production, in addition to safety concerns, has resulted in progressive improvement of nuclear reactors design from Generation I to Generation IV. To complement this progressive trend, materials used for fuel cladding need to be improved or new materials should be developed. In this thesis, I address problems in the improvement of present fuel cladding and also investigate fuel cladding materials to be used in future Generation IV nuclear reactors. In the case of current Zircaloy-4 fuel claddings, a detailed evaluation of the surface roughness effects on their performance and properties of Zircaloy-4 fuel claddings was studied. A smoother surface on Zircaloy-4 cladding tubes is demanded by the customers; however no systematic study is available addressing the effect of surface roughness on the claddings’ performance. Thus the effects of surface roughness on texture, oxidation, hydriding behaviors and mechanical properties of Zircaloy-4 cladding tubes were investigated using various methods. It was found that surface roughness has some effects on the oxidation of Zircaloy-4. Increasing the surface roughness would increase the weight gain, however, this effect was more pronounced at the initial oxidation stages. Synchrotron techniques were used to characterize the electronic structure of zirconium alloys in their oxidized and hydrided states. With this approach, complex interactions between hydrogen and oxygen in the zirconium matrix could be investigated, which could not be resolved using conventional methods. As a candidate for future fuel cladding material, Incoloy 800H/HT, which is expected to be considered in super-critical water-cooled Gen IV reactors, was studied in order to optimize microstructure, texture and grain boundary characteristics. A specific Thermo-Mechanical Processing (TMP) was employed to manipulate the texture, microstructure and grain boundary character distribution. The deformation and annealing textures of thermo-mechanically processed samples were investigated by means of X-ray diffraction and orientation imaging microscopy. It was found that different rolling paths lead to different textures. The origin of different textures in differently (unidirectional and cross) rolled Incoloy 800H/HT at high deformation strains were investigated. In addition, the recrystallization kinetic of differently rolled samples was studied. It was found that the oriented nucleation plays an important role in determining the recrystallization texture. Unidirectional rolled samples exhibited a faster recrystallization kinetic compared with cross rolled ones, due to the presence of γ-fibre. The effect of the aforementioned microstructural parameters (grain size, texture and GBCD) on the oxidation resistance of Incoloy 800H/HT in super-critical water was investigated. It was found that the oxidation resistance of Incoloy 800H/HT can be improved by TMP. The optimum TMP process for enhancing the oxidation resistance was proposed. Microstructural parameters that can improve the oxidation resistance of Incoloy 800H/HT were identified. These findings will contribute to the effective selection of fuel cladding material for application in Gen IV SCW reactors.

Thesis (M.E.-Res.)--University of Wollongong, 2008. / Typescript. Includes bibliographical references: leaf 226-238.

The investigation of reactor pressure vessel (RPV) material from the decommissioned Greifswald nuclear power plant representing the first generation of Russian-type WWER-440/V-230 reactors offers the opportunity to evaluate the real toughness response. The Greifswald RPVs of 4 units represent different material conditions as follows: • Irradiated (Unit 4), • irradiated and recovery annealed (Units 2 and 3), and • irradiated, recovery annealed and re-irradiated (Unit1). The recovery annealing of the RPV was performed at a temperature of 475° for about 152 hours and included a region covering ±0.70 m above and below the core beltline welding seam. Material samples of a diameter of 119 mm called trepans were extracted from the RPV walls. The research program is focused on the characterisation of the RPV steels (base and weld metal) across the thickness of the RPV wall. This report presents test results measured on the trepans from the beltline welding seam No. SN0.1.4. and forged base metal ring No. 0.3.1. of the Units 1 2 and 4 RPVs. The key part of the testing is focussed on the determination of the reference temperature T0 of the Master Curve (MC) approach following the ASTM standard E1921 to determine the facture toughness, and how it degrades under neutron irradiation and is recovered by thermal annealing. Other than that the mentioned test results include Charpy-V and tensile test results. Following results have been determined: • The mitigation of the neutron embrittlement of the weld and base metal by recovery annealing could be confirmed. • KJc values of the weld metals generally followed the course of the MC though with a large scatter. • There was a large variation in the T0 values evaluated across the thickness of the multilayered welding seams. • The T0 measured on T-S oriented SE(B) specimens from different thickness locations of the welding seams strongly depended on the intrinsic structure along the crack front. • The reference temperature RT0 determined according to the “Unified Procedure for Lifetime Assessment of Components and Piping in WWER NPPs - VERLIFE” and the fracture toughness lower bound curve based thereon are applicable on the investigated weld metals. • A strong scatter of the fracture toughness KJc values of the recovery annealed and re-irradiated and the irradiated base metal of Unit 1 and 4, respectively is observed with clearly more than 2% of the values below the MC for 2% fracture probability. The application of the multimodal MC-based approach was more suitable and described the temperature dependence of the KJc values in a satisfactory manner. • It was demonstrated that T0 evaluated according to the SINTAP MC extension represented the brittle fraction of the data sets and is therefore suitable for the nonhomogeneous base metal. • The efficiency of the large-scale thermal annealing of the Greifswald WWER 440/V230 Unit 1 and 2 RPVs could be confirmed.