Starting with the Mean Field Method (MFM) and Boundary Element Method (BEM), we investigate a mathematical model based on these two methods for studying particle-coarsening process in alloys. With MFM, second-phase particles are considered to be merged into bulk matrix, which greatly simplifies computation. However, the Mean-Field model itself is limited to a system with extremely small volume fractions of second phase. By combining BEM with MFM, this mathematical model shows the influence of second phase in particle-coarsening process. Our primary work demonstrates the robustness and capability of this model. This model is however limited to particle coarsening that is far away from grain boundaries. In this dissertation, we successfully extend the model to particle coarsening near grain boundaries. A major improvement made to the previous mathematical model is based on solute atoms conservation and diffusion theory. The capability and validity of the novel model is demonstrated by a binary alloy system. The simulation results are shown to quantitatively reproduce the essential features of particle coarsening near grain boundaries in certain alloys: a) precipitation Free Zones (PFZs) form near grain boundaries, b) the width of PFZs is proportional to square root of time, c) particles at the edge of PFZs are larger than those inside the grain. This novel model is shown to be well suited in describing particle coarsening near grain boundaries. On the other hand, it proves the credibility of the theories built in our mathematical model, i.e., the formation of PFZs near grain boundaries is caused by diffusion of solute atoms. / Thesis / Master of Applied Science (MASc)

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Throughout the 1960s and the early 1970s, almost all developing countries pursued an import substitution policy that sought to develop a domestic manufacturing sector. At the same time, these governments carried out nationalisation programmes based on the view that foreign ownership of industry and assets was a drain on their wealth and hindered the economic development of the nation. Some developing countries saw foreign investment as a continuation of their colonial past and wanted to move away from it. As a result, there was a natural dislike and distrust of foreign investment. However, in the last three decades there has been a sea change in government opinions regarding foreign investment, and now many countries are actively encouraging it. In fact, some governments have paid financial incentives reaching as much as US$150,000 per employee to foreign companies to attract them to their country. These financial incentives are paid on the basis that governments believe that inward investment has positive effects on the economy, the most important of which is transfer of technology. Through improved technology a country can significantly enhance its competitiveness in the global marketplace leading to increased economic growth. With economic growth countries can also improve their social indicators such as education, health etc. Therefore, technology transfer from inward investment is viewed as the catalyst to change within a country. Despite the widespread popularity of governments seeking to attract inward investment there is no conclusive evidence that it leads to positive spillover effects in the form of technology transfer. This study seeks to fill this gap in the current body of academic knowledge, using the case of a small resource abundant country with a low population, such as the UAE, using both qualitative and quantitative research methods. The primary data was obtained through a detailed questionnaire, and provides an in depth approach to understanding the issue of technology transfer for the UAE; while the secondary data, obtained from UNCTAD and the World Bank, is more macro level in nature. The macro level data indicate that certain factors in the UAE are conducive to technology transfer taking place. The primary data seek to interrogate this for the case study presented in this study. In doing so, the primary and secondary data sets are connected in so far as to provide cross reliability through the identification of commonalities and differences of results. This study aims to provide understanding on whether FDI does indeed lead to a transfer of technology from the overseas firm into the host country economy. Understanding such a link within an academic framework allows this study to arrive at relevant policy recommendations that can be taken up by policy makers in similar contexts. The prior literature has shown that FDI both flows into countries that have proven economic growth and that FDI leads to economic growth, and therefore these factors are interrelated. This study has found that FDI can play an important role in filling domestic gaps in investment and also spur economic growth. This study develops a simultaneous regression to test the existence of a joint relationship between economic growth, which is a proxy for technology transfer, and FDI. In the case of host country factors a linear regression model is developed and tested. At a more micro level this study examined the case of Tawazun Economic Council, a high technology organisation that operates within the aerospace and defence industry cluster, in order to understand whether its investments have led to any real impact as far as technology transfer is concerned. The Tawazun Economic Council is a project with a total investment of US$60 billion, and as such allows this research to capture the impact of technology transfer in an enhanced cluster that has aerospace and defence as its core theme. The aerospace and defence sectors have leading edge technology, and therefore a high probability of technology transfer taking place. Through a survey of senior managers within the organisation responsible for strategy development, this study also found that technology transfer has taken place due to the very sophisticated off-take contracts that have been negotiated with buyers and technology suppliers. However, none of these technologies have been applied outside their narrow aerospace and defence usage. In addition, if capital abundant countries wish to capitalise on the technology transfer benefits from FDI then, future government policies should seek to protect intellectual property rights. The novel contribution of this study is that it has identified factors that are important for technology transfer from FDI to take place in capital abundant countries that have a small population. As such, the research has not only increased the current body of knowledge in this area, but has sought to provide policy recommendations that could help in increasing the level of FDI-based technology transfer in developing countries, with a particular emphasis on capital abundant and low population countries.

Dropped objects are among the top ten causes of fatalities and serious injuries in the oil and gas industry. Objects may be dropped during lifting or any other offshore operation. Concerns of health, safety, and the environment (HSE) as well as possible damages to structures require the prediction of where and how a dropped object moves underwater. This study of dropped objects is subdivided into three parts. In the first part, the experimental and simulated results published by Aanesland (1987) have been successfully reproduced and validated based on a two-dimensional (2D) theory for a dropped drilling pipe model. A new three-dimensional (3D) theory is proposed to consider the effect of axial rotation on dropped cylindrical objects. The 3D method is based on a modified slender body theory for maneuvering. A numerical tool called Dropped Objects Simulator (DROBS) has been developed based on this 3D theory. Firstly, simulated results of a dropped drilling pipe model using a 2D theory by Aanesland (1987) are compared with results from 3D theory when rolling frequency is zero. Good agreement is found. Further, factors that affect the trajectory, such as drop angle, normal drag coefficient, binormal drag coefficient, and rolling frequency are systematically investigated. It is found that drop angle, normal drag coefficient, and rolling frequency are the three most critical factors determining the trajectories. In the second part, a more general three-dimensional (3D) theory is proposed to physically simulate the dynamic motion of a dropped cylindrical object underwater with different longitudinal center of gravity (LCG). DROBS has been further developed based on this 3D theory. It is initially applied to a dropped cylinder with LCG = 0 (cylinder #1) falling from the surface of calm water. The calculated trajectories match very well with both the experimental and numerical results published in Aanesland (1987). Then DROBS is further utilized to simulate two dropped cylinders with positive LCG (cylinder #2) and negative LCG (cylinder #3) in Chu et al. (2005), respectively. The simulated results from DROBS show a better agreement with the measured data than the numerical results given in Chu et al. (2005). This comparison again validates and indicates the effectiveness of the DROBS program. Finally, it’s applied to investigate the effects of varying LCG on the trajectory and landing points. Therefore, the newly developed DROBS program could be used to simulate the distribution of landing points of dropped cylindrical objects, as is very valuable in the risk-free zone prediction in offshore engineering. The third part investigates the dynamic motion of a dropped cylindrical object under current. A numerical procedure is developed and integrated into Dropped Objects Simulator (DROBS). DROBS is utilized to simulate the trajectories of a cylinder when dropped into currents from different directions (incoming angle at 0o; 90o; 180o; and 270o) and with different amplitudes (0m/s to 1.0m/s). It is found that trajectories and landing points of dropped cylinders are greatly influenced by currents. Cylinders falling into water are modeled as a stochastic process. Therefore, the related parameters, including the orientation angle, translational velocity and rotational velocity of the cylindrical object after fully entering the water, is assumed to follow normal distributions. DROBS is further used to derive the landing point distribution of a cylinder. The results are compared to Awotahegn (2015) based on Monte Carlo simulations. Then the Monte Carlo simulations are used for predicting the landing point distribution of dropped cylinders with drop angles from 0o to 90o under the influence of currents. The plots of overall landing point distribution and impact energy distribution on the sea bed provide a simple way to indicate the risk-free zones for offshore operation.

The heat affected zone (HAZ) of friction stir welded Al 7075 T7 shows diminished corrosion resistance properties when compared with the parent material. Corrosion attack in this region of the weld is primarily intergranular and is associated with the presence of precipitate free zones. Current TEM research conducted at Brigham Young University by Dr. Bin Cai finds a correlation between precipitate free zone (PFZ) width and grain boundary geometry. As both grain boundary geometry and the PFZ are associated with modes of failure in 7XXX aluminum, this paper makes a comparison of grain boundary character distributions (GBCD) in the HAZ and the parent metal via multi-section plane five-parameter stereology. The stereology is conducted in a convenient macroscopic coordinate frame, associated with the HAZ. This is the first investigation to determine the GBCD in the HAZ of friction-stirred weld material and requires multiple section plane sampling. It is discovered that aluminum here exhibits the property of non-sidedness, a long assumed but unproven characteristic. Further comparisons between the two microstructures are conducted relative to (2-dimensional) grain boundary network connectivity, recovered from EBSD data in each section plane. It is shown that the relative fraction of grain boundaries of misorientation character associated with smaller PFZ size is larger in the HAZ as compared to the parent material. A commensurate decrease in the connectivity (radius of gyration) of grain boundaries of character conducive to larger PFZ size is also found in the HAZ, relative to the parent material. Distribution of inclinations changes as a function of grain boundary geometry. Surface area per unit volume of CSL and low angle random (LAR) misorientations increases in the HAZ, while high angle random (HAR) boundaries decrease. In the case of LAR and some CSL boundaries, a reorientation occurs in which macroscopic normals of these interfaces rotate. It is anticipated that these significant changes in the GBCD within the HAZ could be important in terms of understanding the post-weld mechanical and physical properties in friction-stirred materials.

歯科基礎医学会, 金子 知生 = Tomoo Kaneko, 歯に矯正力を加えた際の圧迫側歯周組織の三次元的様相について = Three-dimensional situation of periodontal tissue at pressure side incident to orthodontic tooth movement, 歯科基礎医学会雑誌, 36(2), APR 1994, pp.170-186 / Hokkaido University (北海道大学) / 博士 / 歯学

A maioria das pessoas não consegue desenvolver em forma adequada, a remoção total do biofilme por médios mecânicos. Em decorrência a complementação com coadjuvantes químicos disponibilizados através de cremes dentais resulta em uma opção valida. O triclosan demonstrou ser efetivo na redução dos depósitos de biofilme supragengival em estudos clínicos com ausência de remoção mecânica por até quatro dias. Contudo, não se sabe o impacto dessa medida na inibição da formação do biofilme subgengival. O objetivo do presente estudo foi comparar o efeito inibitório sobre a formação inicial do biofilme subgengival de uma suspensão de dentifrício contendo 0,3% de Triclosan e 2% de Copolimero com uma suspensão control sem triclosan. Para tanto um ensaio clínico controlado cruzado, randomizado, duplo-cego com quatro dias de duração sem medidas de higiene mecânica foi desenvolvido. Vinte e Seis indivíduos completaram os dois períodos previstos com uma fase de “wash-out” de 10 dias entre os dois. Os indivíduos bochecharam por um minuto com as suspensões a cada 12 horas. Ao longo desse período a presença da zona livre de placa foi registrada a cada 24 horas por um examinador calibrado. A formulação teste inibiu de forma significativa a formação do biofilme subgengival por até 72 horas. Pode-se concluir que bochechos diários com uma suspensão de dentifrício contendo triclosan inibiu de forma significativa a formação inicial do biofilme subgengival por um período de até 72 h comparado com um controle. / Daily systematic removal of dental biofilm in the vast majority of people does not prevent gingivitis and periodontits. Therefore the complement with chemical products delivered through toothpastes results in promising option. Triclosan has been shown effective in reducing supragingival biofilm on 4-days without tooth brushing, but unknown the impact on inhibition of biofilm subgingival. The aim of this study was to compare the inhibitory effect on the early formation of subgingival biofilm from a slurrie of toothpaste containing 0.3% Triclosan and 2% Copolymer vs. control slurrie without triclosan. A randomized crossover controlled double-blind clinical trial of 4-day period without mechanical hygiene was developed. 26 subjects completed 2 periods with wash-out period between them. People were rinsed with slurries at 12hs. A trained examiner evaluated every 24 hours, the plaque-free zone. In conclusion the triclosan/copolymer retards the early formation of biofilm subgingival up to 72 hours.

A maioria das pessoas não consegue desenvolver em forma adequada, a remoção total do biofilme por médios mecânicos. Em decorrência a complementação com coadjuvantes químicos disponibilizados através de cremes dentais resulta em uma opção valida. O triclosan demonstrou ser efetivo na redução dos depósitos de biofilme supragengival em estudos clínicos com ausência de remoção mecânica por até quatro dias. Contudo, não se sabe o impacto dessa medida na inibição da formação do biofilme subgengival. O objetivo do presente estudo foi comparar o efeito inibitório sobre a formação inicial do biofilme subgengival de uma suspensão de dentifrício contendo 0,3% de Triclosan e 2% de Copolimero com uma suspensão control sem triclosan. Para tanto um ensaio clínico controlado cruzado, randomizado, duplo-cego com quatro dias de duração sem medidas de higiene mecânica foi desenvolvido. Vinte e Seis indivíduos completaram os dois períodos previstos com uma fase de “wash-out” de 10 dias entre os dois. Os indivíduos bochecharam por um minuto com as suspensões a cada 12 horas. Ao longo desse período a presença da zona livre de placa foi registrada a cada 24 horas por um examinador calibrado. A formulação teste inibiu de forma significativa a formação do biofilme subgengival por até 72 horas. Pode-se concluir que bochechos diários com uma suspensão de dentifrício contendo triclosan inibiu de forma significativa a formação inicial do biofilme subgengival por um período de até 72 h comparado com um controle. / Daily systematic removal of dental biofilm in the vast majority of people does not prevent gingivitis and periodontits. Therefore the complement with chemical products delivered through toothpastes results in promising option. Triclosan has been shown effective in reducing supragingival biofilm on 4-days without tooth brushing, but unknown the impact on inhibition of biofilm subgingival. The aim of this study was to compare the inhibitory effect on the early formation of subgingival biofilm from a slurrie of toothpaste containing 0.3% Triclosan and 2% Copolymer vs. control slurrie without triclosan. A randomized crossover controlled double-blind clinical trial of 4-day period without mechanical hygiene was developed. 26 subjects completed 2 periods with wash-out period between them. People were rinsed with slurries at 12hs. A trained examiner evaluated every 24 hours, the plaque-free zone. In conclusion the triclosan/copolymer retards the early formation of biofilm subgingival up to 72 hours.

A maioria das pessoas não consegue desenvolver em forma adequada, a remoção total do biofilme por médios mecânicos. Em decorrência a complementação com coadjuvantes químicos disponibilizados através de cremes dentais resulta em uma opção valida. O triclosan demonstrou ser efetivo na redução dos depósitos de biofilme supragengival em estudos clínicos com ausência de remoção mecânica por até quatro dias. Contudo, não se sabe o impacto dessa medida na inibição da formação do biofilme subgengival. O objetivo do presente estudo foi comparar o efeito inibitório sobre a formação inicial do biofilme subgengival de uma suspensão de dentifrício contendo 0,3% de Triclosan e 2% de Copolimero com uma suspensão control sem triclosan. Para tanto um ensaio clínico controlado cruzado, randomizado, duplo-cego com quatro dias de duração sem medidas de higiene mecânica foi desenvolvido. Vinte e Seis indivíduos completaram os dois períodos previstos com uma fase de “wash-out” de 10 dias entre os dois. Os indivíduos bochecharam por um minuto com as suspensões a cada 12 horas. Ao longo desse período a presença da zona livre de placa foi registrada a cada 24 horas por um examinador calibrado. A formulação teste inibiu de forma significativa a formação do biofilme subgengival por até 72 horas. Pode-se concluir que bochechos diários com uma suspensão de dentifrício contendo triclosan inibiu de forma significativa a formação inicial do biofilme subgengival por um período de até 72 h comparado com um controle. / Daily systematic removal of dental biofilm in the vast majority of people does not prevent gingivitis and periodontits. Therefore the complement with chemical products delivered through toothpastes results in promising option. Triclosan has been shown effective in reducing supragingival biofilm on 4-days without tooth brushing, but unknown the impact on inhibition of biofilm subgingival. The aim of this study was to compare the inhibitory effect on the early formation of subgingival biofilm from a slurrie of toothpaste containing 0.3% Triclosan and 2% Copolymer vs. control slurrie without triclosan. A randomized crossover controlled double-blind clinical trial of 4-day period without mechanical hygiene was developed. 26 subjects completed 2 periods with wash-out period between them. People were rinsed with slurries at 12hs. A trained examiner evaluated every 24 hours, the plaque-free zone. In conclusion the triclosan/copolymer retards the early formation of biofilm subgingival up to 72 hours.

Gun violence is a pandemic problem in the United States, resulting in over two thirds of all homicides each year. Consequently, gun related policies have been fiercely debated within the political spectrum, with the 20th century seeing a dramatic increase in gun control legislation. Gun-free zones are designated areas that strictly prohibit all private citizens from carrying a firearm, even those with concealed weapon permits. The statistics indicate that numerous instances of gun related mass shootings have occurred within the confines of these gun-free zones (schools, movie theatres, government installations, etc.). However, little research exists to understand whether citizens actually feel any safer when they are in a gun-free zone. The purpose of this study was to explore citizens’ perceptions about gun control policies, specifically about using gun-free zones, who resided in the five states with the highest rates of gun violence per capitain descending order, these included Virginia, Florida, Texas, Nevada, and Connecticut. Moreover, these five states were the locations of the top five deadliest mass shootings in U.S. history to date. The researcher also discovered how residents felt about pro-gun areas, where responsible citizens could legally carry firearms, as well as determine whether gun-free zones influenced their likelihood of visiting a prescribed location. Finally, the study sought to understand residents’ perceptions regarding using gun-free zones pertaining to their impact on reducing incidents of mass shootings. The researcher filled the gap in the literature regarding knowledge pertaining to citizens’ perceptions about using specific gun control measures, such as gun-free zones, and the influence that the historical evidence had on their perceptions. The answer to RQ1 (do residents associate using gun-free zones with feelings of safety or feelings of concern?) was that participants were twice as likely to associate using gun-free zones with feelings of concern rather than feelings of safety. The answer to the first part of RQ2 (whether participants believed that gun-free zones reduced gun-related violence) was no, based on a 2-to-1 ratio. Responses to the impact of gun control measures on reducing gun violence were closely matched to perceptions of the role of gun-free zones in reducing gun violence. The answer to the second part of RQ2 (do residents believe that gun-free zones lower the occurrences of mass shooting incidents?) was no, again based on a 2-to-1 ratio. The answer to the third and final part of RQ2 (whether participants’ perceptions correlated to the historical/empirical evidence of the location of mass shootings as primarily inside of or outside of gun-free zones) was yes for participants from Florida, Texas, Nevada, and Connecticut and no for participants from Virginia.