Autoignition of non-premixed methane-air mixtures is investigated using first-order Conditional Moment closure (CMC). In CMC, scalar quantities are conditionally averaged with respect to a conserved scalar, usually the mixture fraction. The conditional fluctuations are often of small order, allowing the chemical source term to be modeled as a function of the conditional species concentrations and the conditional enthalpy (temperature). The first-order CMC derivation leaves many terms unclosed such as the conditional scalar dissipation rate, velocity and turbulent fluxes, and the probability density function. Submodels for these quantities are discussed and validated against Direct Numerical Simulations (DNS). The CMC and the turbulent velocity and mixing fields calculations are decoupled based on the frozen mixing assumption, and the CMC equations are cross-stream averaged across the flow following the shear flow approximation. Finite differences are used to discretize the equations, and a two-step fractional method is implemented to treat separately the stiff chemical source term. The stiff ODE solver LSODE is used to solve the resulting system of equations. The recently developed detailed chemical kinetics mechanism UBC-Mech 1.0 is employed throughout this study, and preexisting mechanisms are visited. Several ignition criteria are also investigated. Homogeneous and inhomogeneous CMC calculations are performed in order to investigate the role of physical transport in autoignition. Furthermore, the results of the perfectly homogeneous reactor calculations are presented and the critical value of the scalar dissipation rate for ignition is determined. The results are compared to the shock tube experimental data of Sullivan et al. The current results show good agreement with the experiments in terms of both ignition delay and ignition kernel location, and the trends obtained in the experiments are successfully reproduced. The results were shown to be sensitive to the scalar dissipation model, the chemical kinetics, and the ignition criterion.

Societies in the developed world are becoming increasingly diverse as they experience growth in the number and size of minority groups, including visible minorities, immigrants, and, in some countries, Indigenous peoples. Societys institutions, including the health care system and its professional groups, are increasingly challenged to enhance their understanding of and respect for such societal diversity in providing services, and to work to reflect this diversity in the makeup of their membership. While many of the health care professions, including nursing, have acknowledged the importance of inclusion of individuals from diverse groups, their successes in meeting targeted increases have been limited. The purpose of this research was to elicit stories of nursing leadership that successfully promoted diversity and enhanced inclusiveness within the profession. The research problem was stated as follows: What were the experiences and stories of nurse leaders who successfully provided leadership to increase diversity and inclusion within the profession? The study used modified narrative inquiry research methods. The research was built on a conceptual framework consisting of three major concepts: diversity, critical leadership, and professional closure. The study focused on the stories of five Canadian nurse leaders who described and explained through their stories their leadership characteristics and challenges. Their stories of promoting diversity and inclusion were explored from a critical perspective, using literature found primarily in the fields of nursing and education to guide the exploration.<p> These leaders stories revealed their understanding that the nursing profession currently expected its members to represent the norm-- white middle class females. The stories showed that the participating nurse leaders generally had views of diversity that were broader than culture, ethnicity and race, the views that were most commonly addressed in the mainstream nursing literature. Their broad views of diversity included difference based on gender, sexual orientation, and ability. These views often arose from personal experiences of difference related to ethnicity, language, country of origin, gender, presence of an accent, or family circumstances. The leaders interviewed indicated that they saw a lack of tolerance for difference within the profession, but not simply in relation to cultural or physical difference. They described a lack of acceptance within the profession of different ways of thinking and beingreferred to in the study as diversity of thought. They reported that the profession expected and reinforced conformist thinking and tended to support the status quo.<p> The study findings contributed to an expanded understanding of the conceptual approach of critical leadership as a process to support diversity and promote inclusion in the profession. A conceptual framework for critical leadership, based on the work of Foster (1986; 1989) and Ryan (2006a; 2006b) was enhanced and expanded as a result of the study findings. Critical leadership involved critique, transformation, education, ethics, and inclusion. The study findings supported the view that the profession of nursing, perhaps inadvertently, limited access to the profession by marginalized groups. This process was called professional closure, and occurred as a result of increasing entrance requirements, inconsistent language requirements, and segmenting minority groups in lower paid practical nurse and front line positions, with little opportunity for advancement.<p> These findings about diversity and leadership, and about leadership for diversity, challenged the nursing profession to look beyond its day-to-day busyness, and to move beyond its current locked-down, controlled, risk-averse practices. The study findings challenged the profession to embrace the possibilities of increasing its diversity and inclusiveness, with the ultimate goal of building a better, stronger, more just profession and a better, stronger, more just society.<p> The study has significant implications for theory, practice, research and policy in the profession. From a theoretical perspective, the study pointed to the need for the nursing profession to contemplate its social obligations with respect to promoting social justice in society. The study findings suggest that the profession might engage in national level policy discussions committed to increasing the diversity of the profession in order to reflect the community it serves. This study suggests the need for additional qualitative and quantitative studies on critical leadership to further develop the conceptualizations that evolved in this study. Policy discussions are implicated to address approaches to difference, inclusion, culture, cultural competence, cultural safety, affirmative action and inclusive policy in nursing, nursing education and health care institutions.

The conductivity of acid-etched fractures highly depends on spaces along the fracture created by uneven etching of the fracture walls remaining open after fracture closure. Formation heterogeneities such as variations of mineralogy and permeability result in channels that contribute significantly to the fracture conductivity. Current numerical simulators or empirical correlations do not account for this channeling characteristic because of the scale limitations. The purpose of this study is to develop new correlations for conductivity of acid-etched fracturing at the intermediate scale. The new correlations close the gap between laboratory scale measurements and macro scale acid fracture models. Beginning with acid-etched fracture width profiles and conductivity at zero closure stress obtained by the previous work, I modeled the deformation of the fracture surfaces as closure stress is applied to the fracture. At any cross-section along the fracture, I approximated the fracture shape as being a series of elliptical openings. With the assumption of elastic behavior for the rock, the numerical simulation presents how many elliptical openings remain open and their sizes as a function of the applied stress. The sections of the fracture that are closed are assigned a conductivity because of small-scale roughness features using a correlation obtained from laboratory measurements of acid fracture conductivity as a function of closure stress. The overall conductivity of the fracture is then obtained by numerically modeling the flow through this heterogeneous system. The statistical parameters of permeability distribution and the mineralogy distribution, and Young’s modulus are the primary aspects that affect the overall conductivity in acid-etched fracturing. A large number of deep, narrow channels through the entire fracture leads to high conductivity when the rock is strong enough to resist closure stress effectively. Based on extensive numerical experiments, I developed the new correlations in three categories to predict the fracture conductivity after closure. Essentially, they are the exponential functions that incorporate the influential parameters. Combined with the correlations for conductivity at zero closure stress from previous work, the new correlations are applicable to a wide range of situations.

This investigation carried out the analysis of fracture conductivity in a tight reservoir using laboratory experiments, by applying the procedure known as the dynamic fracture conductivity test. Considering the large number of experiments necessary to evaluate the effect of each parameter and the possible interaction of their combinations, the schedules of experiments were planned using a fractional factorial design. This design is used during the initial stage of studies to identify and discharge those factors that have little or no effect. Finally, the most important factors can then be studied in more detail during subsequent experiments. The objectives of this investigation were focused on identifying the effect of formation parameters such as closure stress, and temperature and fracture fluid parameters such as proppant loading over the final conductivity of a hydraulic fracture treatment. With the purpose of estimating the relation between fracture conductivity and the design parameters, two series of experiments were performed. The first set of experiments estimated the effects of the aliases parameters. The isolated effect of each independent parameter was obtained after the culmination of the second set of experiments. The preliminary test results indicated that the parameters with major negative effect over the final conductivity were closure stress and temperature. Some additional results show that proppant distribution had a considerable role over the final fracture conductivity when a low proppant concentration was used. Channels and void spaces in the proppant pack were detected on these cases improving the conductivity of the fracture, by creating paths of high permeability. It was observed that with experiments at temperatures around 250 degrees F, the unbroken gel dried up creating permeable scales that resulted in a significant loss in conductivity. The results of this investigation demonstrated that dynamic fracture conductivity test procedure is an excellent tool to more accurately represent the effects of design parameters over the fracture conductivity. These results are also the first step in the development of a statistical model that can be used to predict dynamic fracture conductivity.

Linear discontinuous (LD) spatial discretization of the transport operator can generate negative angular flux solutions. In slab geometry, negativities are limited to optically thick cells. However, in multi-dimension problems, negativities can even occur in voids. Past attempts to eliminate the negativities associated with LD have focused on inherently positive solution shapes and ad-hoc fixups. We present a new, strictly non-negative finite element method that reduces to the LD method whenever the LD solution is everywhere positive. The new method assumes an angular flux distribution, e , that is a linear function in space, but with all negativities set-to- zero. Our new scheme always conserves the zeroth and linear spatial moments of the transport equation. For these reasons, we call our method the consistent set-to-zero (CSZ) scheme. CSZ can be thought of as a nonlinear modification of the LD scheme. When the LD solution is everywhere positive within a cell, psi csz = psi LD. If psi LD < 0 somewhere within a cell, psi csz is a linear function psi csz with all negativities set to zero. Applying CSZ to the transport moment equations creates a nonlinear system of equations which is solved to obtain a non-negative solution that preserves the moments of the transport equation. These properties make CSZ unique; it encompasses the desirable properties of both strictly positive nonlinear solution representations and ad-hoc fixups. Our test problems indicate that CSZ avoids the slow spatial convergence properties of past inherently positive solutions representations, is more accurate than ad-hoc fixups, and does not require significantly more computational work to solve a problem than using an ad-hoc fixup. Overall, CSZ is easy to implement and a valuable addition to existing transport codes, particularly for shielding applications. CSZ is presented here in slab and rect- angular geometries, but is readily extensible to three-dimensional Cartesian (brick) geometries. To be applicable to other simulations, particularly radiative transfer, additional research will need to be conducted, focusing on the diffusion limit in multi-dimension geometries and solution acceleration techniques.

Synthesizing nitrogen containing heterocyclic compounds is one of the leading research areas throughout the organic chemistry due to their significant activities on biological systems. Among the various biologically active molecules, indole derivatives are of prime importance on the grounds of their proven clinical roles. Objective of this study is to synthesize new indole derivatives those may contribute treatment of several diseases like their analogues via a recently developed synthetic methodology. Besides this, another objective is to observe and discuss effects of two different substituents on the homophtalic acid system through the synthetic route. Initially starting from homophtalic and 3-methoxybenzoic acid two different homophtalic acid derivatives were synthesized as starting materials. Then the corresponding acyl azide and isocyanate derivatives were generated which might further be used as a precursor to construct a variety of indole derivatives. After synthesizing urea derivatives, ring-closure under the basic conditions generated the heterocyclic units. Whole products were conscientiously purified and characterized.

Le mélange d'un scalaire passif par un écoulement turbulent est étudié. D'abord, la simulation numérique directe (DNS), la simulation des grandes échelles (LES) et des arguments dimensionnels sont employés pour étudier le spectre du flux de scalaire dans une turbulence isotrope avec un gradient moyen uniforme de scalaire. Une loi d'échelle est dérivée. Cette loi conduit à des pentes du spectre variant entre -5/3 et -7/3 en zone inertielle. De premiers résultats de LES plaident en faveur d'un comportement en K^-2. Ensuite, en utilisant une fermeture en deux points (EDQNM), nous montrons qu'aux nombres de Reynolds très élevés, le spectre de flux de scalaire dans la zone intertielle se comporte en K^-7/3. Ce résultat est en accord avec l'analyse dimensionnelle classique de Lumley (1967). Aux nombres de Reynolds correspondant aux expériences de laboratoire, la fermeture conduit à des spectres plus près de K^-2. Nous montrons ensuite que le comportement en K^-2 trouvé en LES est induit par le forçage à grande échelle. La fermeture est alors appliquée au cas des écoulements homogènes cisaillés et les spectres du flux de scalaire longitudinal et transverse sont étudiés. Le spectre du flux longitudinal est trouvé proportionnelle à K^-23/9. Ce résultat est en accord avec l'expérience mais est en désaccord avec l'analyse dimensionnelle classique. Finalement, nous montrons que le lien entre la dispersion de particules et le mélange d'un scalaire permet de formuler une fermeture en deux points et un temps qui ne nécessite l'introduction d'aucune constante dans le modèle.

In November 1999, financial losses led the University of California at San Francisco Medical Center (UCSF) to close all inpatient services at Mount Zion Hospital, a community teaching hospital affiliated with UCSF since 1990. As a result of the closure, Mount Zions primary care residency program (MZPC) was merged with UCSFs university-based primary care program. We examined these events in the context of three major currents in U.S. health care: containment of rising health care costs, financial pressures on teaching hospitals, and the shifting priorities in graduate medical education with respect to subspecialty medicine and primary care. As part of this descriptive study, we investigated the impact of the Mount Zion closure on all UCSF internal medicine residents who were in training at the time. Using a cross-sectional survey, we found that a majority of residents felt the closure was harmful to their training, but that reasons varied by program affiliation. Many specific areas of training remained unaffected. Low morale correlated with abandonment of generalist career plans among some primary care residents (p=0.02). We concluded that the perception of harm reflected a temporary reaction to change rather than actual harm to the quality of the programs, and that while attrition from generalism may have resulted from disillusionment by some residents, it more likely reflected a national decline in interest in primary care since 1997. We also concluded that the closure of Mount Zion and its residency program was a consequence of the shifting emphasis toward subspecialization in the U.S. and is a harbinger of further changes in that direction.

This essay aims to investigate the affects of interaction between different professions in a municipal project. In the project, professional representatives from the social services and schools have collaborated with staff in preschool/school and exchanged knowledge to improve the work around children with antisocial behavior. It is in this essays ambition to create an understanding of how professional practitioners, with a monopoly on certain knowledge, influences the possibilities and limitations of cooperation in a municipal project. This is examined through six qualitative interviews with members of an municipal project. By using theories about professionalization, social closure, alliance strategy and social control it is possible to understand how division into professions creates opportunities and limitations of interaction exchange in collaborative projects. The main conclusion is that well-established professions exclude other professions through social closure when they threaten to challenge the established knowledge monopoly. Project members who don’t challenge the established knowledge monopoly are accepted and an alliance between professions occurs. To succeed with the exchange of knowledge in projects between different professions, it is important to establish a common vision which can gather people's different knowledge and professional backgrounds and get them to strive for a common purpose. It is important to establish interaction for making the project members feel belonging and solidarity with the group.

In aerospace industry and other major mechanical industry systems, engineering components that are subjected to cyclic loads often lead to progressive crack growth that eventually results in struc-tural fracture. The damage tolerance design which is based on the assumption of pre-existed flaws in a structure is an important approach in aircraft industry since it is impossible to have flaw-free manufactured components.In this thesis work, an evaluation of crack propagation models was carried out. Fatigue crack growth threshold and fatigue crack growth rate models were evaluated. A method to present ex-perimental data available was developed to evaluate uncertainties in fatigue life models for more accurate predictions. Currently, a software that is used for predicting crack propagation life is NASGRO. The study has been made for two types of materials: a nickel-iron-based alloy (Inconel 718 forging) and titanium alloys (Ti 6-4 both forging and casting).A threshold model is in the normal case developed for each temperature. A method to model fatigue threshold (ΔKth) has been suggested by assuming temperature independence of ΔKth. In this method, a new threshold model was created by making use of an A/P (Actual/Predicted) plot so that all measured threshold values are on the conservative side of the minimum model. With this method, an understanding of fatigue threshold model was improved over the other method due to the possibilities to model ΔKth with average and minimum threshold values for each load ratio (ΔKth, R).Moreover, a method to investigate which set of parameters that best represent the crack growth behaviour has been suggested. In this method the best set of parameters were chosen to be the set of parameters giving the best fit to the available (da/dN, ΔK) points. The comparison between this method and the method with the set of parameters that give minimum scatter in the A/P values was done.Crack growth rate da/dN log curves were plotted as function of stress intensity range ΔK for R-ratio values ranging from -2 to 0.9 for the two different methods. A distinctive difference between the two methods was observed in Paris region at high temperatures (5500C-6500C) which becomes more obvious at lower R-ratios. Predicting crack propagation rate model with set of parameters giving minimum standard deviation in da/dN points was shown to be less conservative than that of parameter sets giving lowest scatter in A/P. Using both evaluation methods, da/dN versus ΔK plots of Inconel718forging were compared to da/dN (ΔK) plots for the pre-existing data at 5500C for R-ratios ranging from 0 to 0.8. An overall R-ratio influence was observed throughout for both ΔKth and da/dN.