Numerical study of laminar convective cooling of ribs in a parallel plate channel is investigated. Single rib mounted on one channel wall in forced, mixed and free convection is analyzed. Furthermore, the series ribs array with in-line and staggered mounted on channel walls are considered. Through the use of a stream function vorticity transformation, solution of the transformed governing equations for the system is obtained using the control volume method with non-uniform grid. The effects of the Reynolds number, thermal conductivity ratio of rib to fluid and rib¡¦s profile area on heat transfer rate of single rib and rib array are presented. In addition, the effects of the length from inlet to the first rib and the space between ribs for rib array are carried out. A correlation for single and rib array in forced convection is presented to estimate the optimum aspect ratio of rib with various Reynolds number, thermal conductivity ratio of rib to fluid, rib¡¦s profile area. Furthermore, the results of different Gr/Re2 and various channel inclination angle in mixed convection are also examined numerically. The results indicate that both in forced and mixed convection, the optimum aspect ratio of a rib corresponding to the rib with maximum heat transfer rate increases with increasing Re but decreases with K for a fixed rib profile area. In forced convection the optimum aspect ratio of rib array increases with rib¡¦s space but decreases with the length from inlet to the first rib of channel. Then, numerical correlations to predict the optimum aspect ratio of single rib and rib array are developed for fixed rib¡¦s area with various Re, K and rib number. In mixed convection, the optimum aspect ratios of single rib and staggered rib array increase with not only the inclination angle but also Gr/Re2.

Current high power LEDs are used popularly, energy saving can be achieved if the heat transfer performance of a high power LED is increased. Numerical analysis is carried out herein to study the parameters effect on the cooling performance for the heat sinks of the LED projector. The parameters include fin spacing, fin depth, fin thickness, base thickness and flow speed. The numerical results reveal that the parameters of the heat sinks significantly affects the average Nusselt Number. The results of this study can provide design references for LED projector.

In the mid 1980s, national enterprises started to hire illegal foreign workers without the official introduction in Taiwan. Following with the soaring national economic growth, wage and income and the popular trend in stock, lottery and gambling games in 1985, workers were less willing to work. Industries, such as the 3K or 3D industry (dirty, dangerous and difficult), were less favored. In addition with the delaying participation of youth in job market due to the rising educational level, the supply for grassroots workers faced decreasing. Meanwhile, the national birth controlling policy also led to low birth rate, slow population growth and aging population, which triggered a serious labor shortage in Taiwan and enterprises also started calling for solving the labor shortage problem by introducing foreign workers. When Taiwanese government had first initiated the 14 major infrastructures project, the deadline of the project was kept postponing due to labor shortage. Therefore, the government set up a ¡§mechanism of workers demanding for14 major infrastructures project¡¨ by executive order, allowing entities to introduce foreign workers for the project. 3 years had gone, a ¡§mechanism for temporary labor shortage¡¨ was enforced. This mechanism allowed domestic industries to introduce foreign workers officially, announcing it can be applied to 15 jobs in 6 major industries. Through legislative procedure, the Employment Service Act had been passed on 3rd reading in 1992. Thus, a formal source of law can be found for introducing foreign workers. A riot started by Thai workers at Kaohsiung MRT in August 2005 not only revealed problems, such as foreign workers management and human rights, but also affected Taiwan¡¦s international reputation by large. Some foreign workers have received maltreatments, such as forced labor or involuntary labor. Moreover, the amount of foreign workers who are unaccounted for has kept increasing, too. In 2012, more than 30 thousand are missing. For researching the core problem, based on the 5 major frameworks of administration law, including the administrative principles, administrative organization, administrative authority, administrative remedy and administrative supervision, this study aims at examining the legal system of missing foreign workers prevention for national police to redress the deficiency of the legal system with researching by reference, historical analysis, comparative analysis and induction analysis. By comparing current management manners in Hong Kong, Singapore, Austria and Switzerland, I wish some valuable lessons can be learnt with more significant and concrete suggestions for related regulations to the missing foreign workers prevention and to protect human rights.

Heat transfer and fluid flow are studied numerically for a repeating microchannel array with water as the circulating fluid. Generalized transport equations are discretized and solved in three dimensions for velocities, pressure, and temperature. The SIMPLE algorithm is used to link pressure and velocity fields, and a thermally repeated boundary condition is applied along the repeating direction to model the repeating nature of the geometry. The computational domain includes solid silicon and fluid regions. The fluid region consists of a microchannel with a hydraulic diameter of 85.58μm. Independent parameters that were varied in this study are channel aspect ratio and Reynolds number. The aspect ratios range from 0.10 to 1.0 and Reynolds number ranges from 50 to 400. A constant heat flux of 90 W/cm2 is applied to the northern face of the computational domain, which simulates thermal energy generation from an integrated circuit. A simplified model is validated against analytical fully developed flow results and a grid independence study is performed for the complete model. The numerical results for apparent friction coefficient and convective thermal resistance at the channel inlet and exit for the 0.317 aspect ratio are compared with the experimental data. The numerical results closely match the experimental data. This close matching lends credibility to this method for predicting flows and temperatures of water and the silicon substrate in microchannels. Apparent friction coefficients linearly increase with Reynolds number, which is explained by increased entry length for higher Reynolds number flows. The mean temperature of water in the microchannels also linearly increases with channel length after a short thermal entry region. Inlet and outlet thermal resistance values monotonically decrease with increasing Reynolds number and increase with increasing aspect ratio. Thermal and friction coefficient results for large aspect ratios (1 and 0.75) do not differ significantly, but results for small aspect ratios (0.1 and 0.25) notably differ from results of other aspect ratios.

The assessment of noncognitive constructs poses a number of challenges that set it apart from traditional cognitive ability measurement. Of particular concern is the influence of response biases and response styles that can influence the accuracy of scale scores. One strategy to address these concerns is to use alternative item presentation formats (such as multidimensional forced choice (MFC) pairs, triads, and tetrads) that may provide resistance to such biases. A variety of strategies for constructing and scoring these forced choice measured have been proposed, though they often require large sample sizes, are limited in the way that statements can vary in location, and (in some cases) require a separate precalibration phase prior to the scoring of forced-choice responses. This dissertation introduces new item response theory models for estimating item and person parameters from rank-order responses indicating preferences among two or more alternatives representing, for example, different personality dimensions. Parameters for this new model, called the Hyperbolic Cosine Model for Rank order responses (HCM-RANK), can be estimated using Markov chain Monte Carlo (MCMC) methods that allow for the simultaneous evaluation of item properties and person scores. The efficacy of the MCMC parameter estimation procedures for these new models was examined via three studies. Study 1 was a Monte Carlo simulation examining the efficacy of parameter recovery across levels of sample size, dimensionality, and approaches to item calibration and scoring. It was found that estimation accuracy improves with sample size, and trait scores and location parameters can be estimated reasonably well in small samples. Study 2 was a simulation examining the robustness of trait estimation to error introduced by substituting subject matter expert (SME) estimates of statement location for MCMC item parameter estimates and true item parameters. Only small decreases in accuracy relative to the true parameters were observed, suggesting that using SME ratings of statement location for scoring might be a viable short-term way of expediting MFC test deployment in field settings. Study 3 was included primarily to illustrate the use of the newly developed IRT models and estimation methods with real data. An empirical investigation comparing validities of personality measures using different item formats yielded mixed results and raised questions about multidimensional test construction practices that will be explored in future research. The presentation concludes with a discussion of MFC methods and potential applications in educational and workforce contexts.

Hipotekos sąvoka yra kilusi iš graikų kilmės žodžio „hypotheke“, reiškiančio daikto įkeitimą, kai įkeičiamas daiktas paliekamas valdyti skolininkui. Nors įkeitimo teisės gimtine yra laikomas Babilonas, hipotekos institutas vakarų teisės tradicijos valstybėse atsirado kaip romėnų teisės recepcijos padarinys. Kaip ir Senovės Romoje, Lietuvoje hipoteka perėjo keletą raidos etapų – nuo 1818 m. Ipotekos įstatų priėmimo iki reformuotos hipotekos sistemos įgyvendinimo šiuo metu galiojančiuose CK ir CPK. Nors įsigaliojus naujiems civiliniams įstatymams hipotekai buvo priskirtas daiktinis teisinis režimas, dvejopa nekilnojamojo turto įkeitimo teisės prigimtis neleidžia jos laikyti griežtai daiktine teise, todėl magistro baigiamajame darbe analizuojama hipotekos teisinės prigimties problematika, nagrinėjamas hipotekos, kaip daiktinio prievolių įvykdymo užtikrinimo būdo, santykis su kitomis prievolių užtikrinimo priemonėmis. Darbe prieinama išvados, jog daiktiniai hipotekos požymiai lemia hipotekos patikimumą, nes hipotekos objektu yra materialus daiktas, kuris išlieka ir tuomet, kai skolininkas miršta, išlaiko savo vertę, kai skolininkas tampa nemokus. Hipoteka galima užtikrinti būsimos, preliminarios sutarties įvykdymą, hipotekos kreditorius gali nukreipti skolos išieškojimą į įkeistą turtą, nepriklausomai nuo to, ar jis yra pas skolininką, ar pas trečiuosius asmenis, nekilnojamojo turto realizavimas praktiškai visados yra garantuotas, be to, hipotekos kreditoriaus reikalavimai iš... [to full text] / The concept of mortgage originated from a Greek word “hypotheke” that means a thing in mortgage but the thing is still left for the owner to posses. Although the homeland of lien is considered to be Babylon, the legal institute of mortgage appeared as the result of Roman law reception in the states of western law tradition. In Lithuania, like in the ancient Rome, mortgage progressed from one developmental stage to another, i.e. from 1818 when the regulations of mortgage were accepted till the implementation of reformed mortgage system in Civil Code and Code of Civil Procedure that are available now. However when new civil laws became operative, a material legal regime was attached to mortgage, the dual nature of mortgage law cannot be considered strictly the right in rem, so in the Master thesis one analyses the topic of mortgage legal nature, researches mortgage, as a real security device, and relationship with other security devices. In the work one makes conclusions that material features of mortgage determine the reliability of mortgage, because the object of mortgage is a material thing that remains even when a debtor dies and sustains its value when a debtor becomes insolvent. Mortgage can assure the fulfillment of future, tentative agreement, the creditor of a hypothec can direct the recovery to a mortgaged property, independent of the fact whether a debtor or third party has it, the realization of realty is practically always guaranteed, moreover, the hypothec... [to full text]

Due to more and more aggressive designs in turbomachinery, assuring the structural integrity of its components has become challenging. Also influenced by this trend is blade design, where lighter and slimmer blades, in combination with higher loading, lead to an increased risk of failure, e.g. in the form of blade vibration. Methods have been proposed to reduce vibration amplitudes for subsonic engines, but cannot directly be applied to transonic regimes due to the additional physical phenomena involved. Therefore the present work investigates numerically the influence of two methods for reducing blade vibration amplitudes in transonic turbomachines, namely varying the blade count ratio and clocking. As it is known that clocking affects the efficiency, the concurrent effects on vibration amplitudes and efficiency are analyzed and discussed in detail. For the computational investigations, the proprietary Fortran-based non-linear, viscous 3D-CFD solver VolSol is applied on two transonic compressor cases and one transonic turbine case. In order to reduce calculation time and to generate the different blade count ratios a scaling technique is applied. The first and main part of this work focuses on the influence of the reduction techniques on aerodynamic forcing. Both the change in blade count ratio and clocking position are found to have significant potential for reducing aerodynamic force amplitudes. Manipulation of the phasing of excitation sources is found herein to be a major contributor to the amplitude variation. The lowest stimulus results are achieved for de-phased excitation sources and results in multiple blade force peaks per blade passing. In the case of blade count ratio variation it was found that blockage for high blade count ratios and the change in potential field size have significant impacts on the blade forcing. For the clocking investigation, three additional operating points and blade count ratios are analyzed and prove to have an impact on the force reduction achievable by clocking. The second part of the work evaluates the influence of clocking on the efficiency of a transonic compressor. It is found that the efficiency can be increased, but the magnitude of the change and the optimal wake impingement location depend on the operating point. Moreover it is shown that optimal efficiency and aerodynamic forcing settings are not directly related. In order to approximate the range of changes of both parameters, an ellipse approximation is suggested. / <p>QC 20130911</p> / TURBOPOWER

<p>One of the grand challenges faced by industry is the accurate prediction of unsteady aerodynamics events, including frequency lock-in and forced response. These aeromechanical incidents occurring in airplane engines and gas turbines can cause high-amplitude blade vibration and potential failure of the engine or turbine. During the last decades, the development of computational fluid dynamics has allowed the design and optimization of complex components while reducing the need for expensive engine testing. However, the validation of frequency lock-in and forced response numerical results with experimental data is very incomplete. Despite tremendous advances in computational capabilities, industry is still looking to validate design tools and guidelines to avoid these potentially costly aeroelastic events early in the design process. </p><p>The research efforts presented in this dissertation investigate the aeroelastic phenomena of frequency lock-in and forced response in turbomachinery. First, frequency lock-in is predicted for two structures, namely a two-dimensional cylinder and a single three-dimensional airfoil, and the results are compared to experimental data so that the methods can be extended to more complex structures. For these two simpler structures, a frequency domain harmonic balance code is used to estimate the natural shedding frequency and the corresponding lock-in region. Both the shedding frequencies and the lock-in regions obtained by an enforced motion method agree with experimental data from previous literature and wind tunnel tests. Moreover, the aerodynamic model of the vibrating cylinder is coupled with the structural equations of motion to form a fluid-structure interaction model and to compute the limit-cycle oscillation amplitude of the cylinder. The extent of the lock-in region matches the experimental data very well, yet the peak amplitude is underestimated in the numerical model. We demonstrate that the inclusion of the cylinder second degree of freedom has a significant impact on the cylinder first degree of freedom amplitude. Moreover, it is observed that two harmonics need to be kept in the equations of motion for accurate prediction of the unsteady forces on the cylinder. </p><p>The second important topic covered is a comprehensive forced response analysis conducted on a multi-stage axial compressor and compared with the initial data of the largest forced response experimental data set ever obtained in the field. Both a frequency domain and a time domain codes are used. The steady-state and time-averaged aerodynamic performance results compare well with experimental data, although losses are underestimated due to the lack of secondary flow paths and fillets in the model. The use of mixing planes in the steady simulations underpredicts the wakes by neglecting the important interactions between rows. Therefore, for similar cases with significant flow separation, the use of a decoupled method for forced response predictions cannot yield accurate results. A full multi-row transient analysis must be conducted for accurate prediction of the wakes and surface unsteady pressures. Finally, for the first time, predicted mistuned blade amplitudes are compared to mistuned experimental data. The downstream stator is found to be necessary for the accurate prediction of the modal forces and vibration amplitudes. The mistuned rotor is shown to be extremely sensitive to perturbations in blade frequency mistuning, aerodynamic asymmetry, and excitation traveling wave content. Since this dissertation presents the initial results of a five-year research program, more research will be conducted on this compressor to draw guidelines that can be used by aeromechanical engineers to safely avoid forced response events in the design of jet engines and gas turbines.</p> / Dissertation

Mechanical ventilation saves lives, but it is an intervention fraught with the potential for serious complications. Prevention of these complications has become the focus of research and critical care in the last twenty years. This thesis presents the first use, or the application under new conditions, of three technologies that could contribute to optimization of mechanical ventilation. Optoelectronic plethysmography was used in Papers I and II for continuous assessment of changes in chest wall volume, configuration, and motion in the perioperative period. A forced oscillation technique (FOT) was used in Paper III to evaluate a novel positive end-expiratory pressure (PEEP) optimization strategy. Finally, in Paper IV, FOT in conjunction with an optical sensor based on a self-mixing laser interferometer (LIR) was used to study the oscillatory mechanics of the respiratory system and to measure the chest wall displacement. In Paper I, propofol anesthesia decreased end-expiratory chest wall volume (VeeCW) during induction, with a more pronounced effect on the abdominal compartment than on the rib cage. The main novel findings were an increased relative contribution of the rib cage to ventilation after induction of anesthesia, and the fact that the rib cage initiates post-apneic ventilation. In Paper II, a combination of recruitment maneuvers, PEEP, and reduced fraction of inspired oxygen, was found to preserve lung volume during and after anesthesia. Furthermore, the decrease in VeeCW during emergence from anesthesia, associated with activation of the expiratory muscles, suggested that active expiration may contribute to decreased functional residual capacity, during emergence from anesthesia. In the lavage model of lung injury studied in Paper III, a PEEP optimization strategy based on maximizing oscillatory reactance measured by FOT resulted in improved lung mechanics, increased oxygenation, and reduced histopathologic evidence of ventilator-induced lung injury. Paper IV showed that it is possible to apply both FOT and LIR simultaneously in various conditions ranging from awake quiet breathing to general anesthesia with controlled mechanical ventilation. In the case of LIR, an impedance map representing different regions of the chest wall showed reproducible changes during the different stages that suggested a high sensitivity of the LIR-based measurements.

This thesis is a qualitative study of health practices of resettled Vietnamese refugees in Victoria, B.C. This thesis looks at the past and present sociocultural and political experiences of forced migration and resettlement which have influenced definitions, understandings and practices of medicine among refugees today. Previous studies of Vietnamese refugee groups have identified traditional Chinese medicine and biomedicine as complementary healing systems which are used. These studies report that Vietnamese refugee groups still experience sociocultural barriers to care after resettlement to their host country. This research found that resettled Vietnamese refugees in Victoria, B.C. still demonstrate a syncretic approach to medical practice which is also inclusive of traditional Vietnamese medicine (TVM). Using semi-structured interviews and participant observation methods to collect materials and gain a detailed understanding of how medicine is understood and used by resettled Vietnamese refugees, this study is based on interviews from a sample of 7 resettled Vietnamese refugees, six female and one male. I demonstrate that medicine is much more complex than simply practicing different forms of medicine. There are underlying sociocultural and political issues that continue to shape how medicine is defined and represented by resettled Vietnamese refugees today. This thesis identifies TVM as a recognized healing system and shows how perceptions of medicine and health have changed over the course of resettlement. Although forced migration and long term resettlement has resulted in the internalization of certain socio-cultural and political norms and expectations regarding medical practice, some of these changes have been beneficial for resettled Vietnamese refugees in Victoria, B.C. / Graduate / 0326 / 0566 / 0631 / jcly2@uvic.ca