This master's thesis analyses fluid flow in an open cylindrical tank with vortex using numerical simulation. The theoretical part introduces a set of equations governing fluid flow and relations used to describe vortex motion. A general overview of terms used in computational fluid dynamics is presented. The experimental section consists of three parts. The vortex modelling is performed using ANSYS Fluent software. Data are consequently analysed within ANSYS CFD-Post software tool. Special focus is put on the vortex shape that is fitted with a curve corresponding to a probability density function of the Cauchy distribution. Results are then plotted in MATLAB software.

Moderne Theorien der Verhaltenskontrolle unterscheiden zwei Systeme, wobei das Handeln gesunder Individuen von beiden geprägt ist: Das retrospektiv agierende habituelle, sog. modellfreie Verhalten zeichnet sich durch Wiederholung zuvor belohnter Entscheidungen aus. Es passt sich nur langsam an möglicherweise veränderte Umweltbedingungen an. Die verstärkte Nutzung des habituellen Systems gilt als assoziiert mit verschiedenen psychischen Erkrankungen. Dem gegenüber steht das zielgerichtete, sog. modellbasierte Verhalten, das sich durch vorausschauende Entscheidungen auszeichnet. Hierbei werden die möglichen Konsequenzen einer Handlung berücksichtigt, um ein gewünschtes Ergebnis zu erreichen. Dazu wird ein „mentales“ Modell der Umwelt- bedingungen erstellt. In einer Verhaltensstudie mit 39 Versuchspersonen wurde untersucht, ob biopsychologischer Stress zu einer Reduktion von modellbasiertem hin zu mehr modellfreiem Verhalten führt. Dazu absolvierten 39 Versuchspersonen eine sequentielle Entscheidungsaufgabe, nachdem sie psychosozialem Stress ausgesetzt wurden. Subjektive und physiologische Stress-Parameter wurden über das Experiment hinweg wiederholt erhoben. Ein direkter Effekt von akutem Stress auf das Gleichgewicht modellfreien vs. modellbasierten Verhaltens konnte nicht beobachtet werden. Allerdings zeigten diejenigen Versuchspersonen, die in den letzten zwei Jahren eine hohe Anzahl an stressbehafteten Lebensereignissen aufwiesen (chronischer Stress), signifikant weniger modellbasiertes Verhalten nach der Exposition von akutem Stress als in der Kontrollbedingung. Darüber hinaus korrelierte physiologische Stressreaktivität (stressbedingte Cortisol- Ausschüttung) negativ mit modellbasiertem Entscheidungsverhalten, während subjektive Stressreaktivität (basierend auf Fragebögen) positiv mit modellbasiertem Verhalten assoziiert war. Der in der Forschung beschriebene Einfluss von akutem und chronischem Stress auf die Entstehung und Aufrechterhaltung psychischer Erkrankungen könnte demnach teilweise über ein solches Ungleichgewicht der beiden Entscheidungsstrategien vermittelt sein.

Les personnes LGBTQI+ migrantes portent plusieurs identités minoritaires et par ce fait, sont plus à risque de subir plusieurs formes de discrimination et d’oppression, tel que l’homo-lesbo-bitransphobie, le racisme, le sexisme et/ou la xénophobie. Bien qu’il y ait un intérêt grandissant à l’échelle internationale dans la recherche auprès des communautés LGBTQI+ migrantes, peu de recherches portent sur les pratiques de soutien par les pairs auprès de cette population. Ma démarche de recherche a été inscrite dans une recherche communautaire plus large menée par Dr. Edward Lee en partenariat avec AGIR (Action LGBTQI+ avec les immigrant·e·s et les réfugié·e·s). AGIR est un organisme communautaire qui soutient les personnes migrantes LGBTQI+ et en particulier les réfugié·e·s et les demandeur·se·s d’asile LGBTQI+ à Montréal. Nous avons mobilisé la théorie intersectionnelle et le modèle du stress minoritaire pour analyser un total de (N=14) entretiens qualitatifs semi-dirigés auprès des membres soutenu·e·s, membres du conseil d’administration, membres de l’équipe de soutien et employé·e·s qui sont actuellement ou ont été historiquement impliqués au sein d'AGIR. Des retombées positives du soutien par les pairs ont été constatées en lien avec la santé mentale et le bien-être, la navigation sociale et les relations sociales. Toutefois, des défis en lien avec l’ambiguïté du rôle du-de la pair·e, le manque de formations et de supervision, le risque de burnout et de trauma vicariant ont été identifiés. Finalement, nous avons formulé neuf recommandations en lien avec les récits des participant·e·s pour favoriser le modèle de soutien par les pair·e·s au sein d’AGIR. / LGBTQI + migrants have multiple minority identities and therefore are more at risk of suffering several forms of discrimination and oppression, such as homo-lesbo-bi-transphobia, racism, sexism and/or xenophobia. Although the interest in research with LGBTQI+ migrant communities is increasing internationally, there are few research projects on peer support practices among this population. My research approach is part of a larger community-based research led by Dr. Edward Lee in partnership with AGIR (Action LGBTQI + with immigrants and refugees). AGIR is a community organization that supports LGBTQI+ migrants and in particular LGBTQI + refugees and asylum seekers in Montreal. We mobilized intersectional theory and the minority stress model to analyze a total of (N = 14) qualitative semi-structured interviews with supported members, board members, support team members and employees currently or historically involved within AGIR. Positive results regarding AGIR’s peer support are related to mental health and well-being, social navigation and social relationships. However, challenges related to the ambiguity of the peer role, the lack of training and supervision, and the risk of burnout and vicarious trauma have been identified. Finally, we suggested nine recommendations in connection with participants’ experiences, to promote the peer support model within AGIR. / Las personas migrantes LGBTQI + portan varias identidades minoritarias y, por lo tanto, corren un mayor riesgo de sufrir diversas formas de discriminación y opresión, como la homo-lesbo-bi-transfobia, el racismo, el sexismo y/o la xenofobia. Aunque existe un creciente interés internacional en la investigación con comunidades LGBTQI+ migrantes, poca investigación se ha centrado en las prácticas de apoyo entre pares en esta población. El presente proyecto de investigación fue parte de una investigación comunitaria más grande dirigida por el Dr. Edward Lee en asociación con AGIR (Acción LGBTQI + con inmigrantes y refugiados). AGIR es una organización comunitaria que apoya a los migrantes LGBTQI + y en particular a los refugiados y solicitantes de asilo LGBTQI+ en Montreal. En este proyecto mobilizamos la teoría interseccional y el modelo de estrés minoritario para analizar un total de (N = 14) entrevistas semiestructuradas cualitativas con miembros usuarixs, miembros del consejo de administración, miembros del equipo de apoyo y empleadxs que están actualmente o han estado involucradxs históricamente en AGIR. Este proyecto a documentado efectos positivos del apoyo entre pares en relación con la salud mental y el bienestar, la navegación social y las relaciones sociales. Sin embargo, se han identificado desafíos relacionados con la ambigüedad del rol de los pares, la falta de capacitación y supervisión, el riesgo de burnout y de trauma indirecto. Finalmente, hicimos nueve recomendaciones relacionadas con las experiencias de los participantes para promover el modelo de apoyo entre pares dentro de AGIR.

<p dir="ltr">For many, spiritual beliefs and religious affiliation exist as a protective factor, providing significant emotional, psychological, and social support (Ibrahim & Dykeman, 2011). However, for others, abuse within the power structures of religion can also inflict great harm—particularly within marginalized communities—resulting in religious trauma. The LGBTQIA+ community has historically experienced marginalization and discrimination within various religious contexts and doctrines, becoming a group particularly vulnerable to religious trauma (Simmons et al., 2017; Swindle, 2017). This type of trauma has often been overlooked in the therapy room and within the broader Marriage and Family Therapy field. This thesis addresses this gap through the creation of an introductory training for therapists on religious trauma that many in LGBTQIA+ community experience. Grounded in religious trauma research and trauma-informed client care, the training seeks to enhance therapists' capacity to navigate these complex terrains with empathetic and informed care (Ellis et al., 2022). The aim is to create a therapeutic landscape where healing and self-compassion become more accessible to LGBTQIA+ individuals impacted by religious trauma.</p>

Drug abuse is becoming an increasing problem in Kenya. A number of studies carried out in the country show that almost every Kenyan youngster at one time or another experiments with drugs, especially beer and cigarettes. The major cause of concern is that a significant proportion of these young people eventually get addicted posing a threat to their own health and safety, while creating difficulties for their families and the public at large into difficulties. This study sought to establish the current trend of drug abuse among students in Kenyan secondary schools, and to analyze the strategies used to address the problem. The ultimate aim was to propose a programme for prevention and intervention. The study is a descriptive survey. In view of this, the field survey method was adopted to collect quantitative and qualitative data, using questionnaires and interviews. Both qualitative and quantitative approaches were used in data analysis, thus there was a mixed model research design approach to data analysis. The analysis of structured items was mainly done using the Statistical Package for Social Sciences (SPSS). The key findings from the study were that drug abuse among students is common; both boys and girls have abused drugs with the majority being in boys‟ schools; the greatest ratio of drug abusers to non-abusers among the sampled schools are aged between 20 and 22 years; there is a significant relationship between drug abuse and age, use of drugs by other family members and easy access to drugs. A variety of factors contribute to drug abuse with the majority of students citing curiosity, acceptance by peers and ignorance as to the dangers of drug abuse as the main reasons. Both the school administrators and teachers face a number of challenges in an attempting to curb drug abuse in schools. The study makes a number of recommendations for policy and further research. A number of guidelines are proposed for developing a programme for prevention and intervention. / Educational Studies / D. Ed. (Socio-Education)

A decade of growth and wealth generation in Russia ended in 2009 with the collapse in GDP and rising unemployment. This Great Recession added new economic challenges to the ‘old’ problems facing children and families, including widening income inequalities and the phenomenon of social orphanage. One question is how the new and existing material pressures affect parent–child relationships. This research contributes to the answer by examining, in aggregate terms, the role poverty plays in the allocation of parental time in this emerging economy. Utilising a nationally representative sample of children, it explores how child interactions with parents are affected by aggregate and idiosyncratic shocks. Drawing on the rational choice paradigm and its critique, we put forward the Parental Time Equilibrium as an analytical guide to the study. This theoretical approach presents individual decisions concerning time spent with children over the long term as the product of a defined equilibrium between resources and demands for involvement. We test this approach through pooled cross-sectional and panel analyses based on the Russian Longitudinal Monitoring Survey dataset from 2007 to 2009. Children in low-income households face the double disadvantage of a lack of money and time investments at home, with both persistent and transient poverty being associated with lower than average parental time inputs in the sample. Moreover, while on average, we find that children do maintain the amount of time they spend with their parents under conditions of severe financial strain, low–income children lose out on play time with the mother. Material resources cannot be considered in isolation from structural disadvantages, of which rural location in particular is detrimental for parent–child time together. The study demonstrates that the cumulative stress of adverse macro-economic conditions and depleted material resources makes it difficult for parents to sustain their human investment in children. The evidence this study provides on the associations between economic stress and pa-rental time allocations advances our knowledge of the disparities of in the childhood experience in modern Russian society. The findings strongly support the equal importance of available resources and basic demand for involvement, thus drawing policy attention to the need to address both in the best interests of children.

This exploratory study posited that being in an insecure marriage would increase marital conflict and perceived relational aggression when the couple is experiencing economic constraints. The cross-sectional design assessed two groups of marriages: secure and insecure. A structural equation model using multiple group comparison tested the effect of each type of marriage, controlling for husband and wife education, number of children, and length of marriage. Results indicated that husbands who identify as insecure experience greater marital conflict and perceive their spouses to be more psychologically aggressive. There was also evidence of a cross-lag effect indicating husbands' perceived marital conflict positively influences wives' perceptions of greater spousal psychological aggression for insecure couples, but not secure couples. This is the first study to use attachment as a moderating variable in the family stress model. Future research should look to include greater measures of attachment, with a focus on longitudinal designs. Implications are also discussed. / Graduation date: 2013

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-03-23T01:44:32Z No. of bitstreams: 1 GUSTAVO GOMES SAMPAIO CURSINO - TESE PPGEQ 2016.pdf: 5939681 bytes, checksum: 518baf4150ea2fb7085706252276b9fa (MD5) / Made available in DSpace on 2018-03-23T01:44:32Z (GMT). No. of bitstreams: 1 GUSTAVO GOMES SAMPAIO CURSINO - TESE PPGEQ 2016.pdf: 5939681 bytes, checksum: 518baf4150ea2fb7085706252276b9fa (MD5) Previous issue date: 2016-04-18 / Este trabalho teve o propósito de determinar o comportamento dos gases na seção de radiação de um combustor de ar que pertence a uma planta industrial. O corpo metálico do equipamento rompeu em seu primeiro ano de operação, devido a um problema conceitual em sua geometria. A fluidodinâmica computacional (CFD), por meio do método dos volumes finitos, foi utilizada para desenvolver um modelo tridimensional que pudesse reproduzir o perfil de temperatura e o comportamento do fluxo do ar de combustão no equipamento. Na simulação, através do uso do software ANSYS CFX, foram utilizados: (i) o modelo de turbulência Reynolds Stress Model (RSM); (ii) as malhas hexaédrica, tetraédrica e prismática; (iii) o modelo de radiação P-1; e (iv) o modelo de combustão Eddy Dissipation Concept (EDC). Como resultado, foram apresentadas quatro possíveis mudanças na geometria do combustor de ar que, caso adotadas, eliminariam os riscos de novas falhas e garantiriam a continuidade operacional da unidade de processo. / This paper has the objective to describe the behavior of the flow and temperature of the flue gas in the radiation section of the vessel used to preheat air in a combustor. The equipment failed in its first operational year, due to a conceptual problem in its geometry. The CFD code based on finite volume method was applied to simulate the physical model of combustor using the ANSYS CFX software, reproducing the main features of the preheater. The simulation had considered: (i) Reynolds Stress Model (RSM) as turbulence model, (ii) The meshes applied were the hexahedral, tetrahedral and prismatic, (iii) P-1 was used as the radiation model and (iv) Eddy Dissipation Concept (EDC) as combustion model. Through the simulation was possible to propose four different kind of combustor geometry modification, that the application of anyone of them would eliminate the risk of new failures, ensuring the unit production availability.

Drug abuse is becoming an increasing problem in Kenya. A number of studies carried out in the country show that almost every Kenyan youngster at one time or another experiments with drugs, especially beer and cigarettes. The major cause of concern is that a significant proportion of these young people eventually get addicted posing a threat to their own health and safety, while creating difficulties for their families and the public at large into difficulties. This study sought to establish the current trend of drug abuse among students in Kenyan secondary schools, and to analyze the strategies used to address the problem. The ultimate aim was to propose a programme for prevention and intervention. The study is a descriptive survey. In view of this, the field survey method was adopted to collect quantitative and qualitative data, using questionnaires and interviews. Both qualitative and quantitative approaches were used in data analysis, thus there was a mixed model research design approach to data analysis. The analysis of structured items was mainly done using the Statistical Package for Social Sciences (SPSS). The key findings from the study were that drug abuse among students is common; both boys and girls have abused drugs with the majority being in boys‟ schools; the greatest ratio of drug abusers to non-abusers among the sampled schools are aged between 20 and 22 years; there is a significant relationship between drug abuse and age, use of drugs by other family members and easy access to drugs. A variety of factors contribute to drug abuse with the majority of students citing curiosity, acceptance by peers and ignorance as to the dangers of drug abuse as the main reasons. Both the school administrators and teachers face a number of challenges in an attempting to curb drug abuse in schools. The study makes a number of recommendations for policy and further research. A number of guidelines are proposed for developing a programme for prevention and intervention. / Educational Studies / D. Ed. (Socio-Education)

In this thesis, we investigate several inferential issues regarding the lifetime data from exponential distribution under different censoring schemes. For reasons of time constraint and cost reduction, censored sampling is commonly employed in practice, especially in reliability engineering. Among various censoring schemes, progressive Type-I censoring provides not only the practical advantage of known termination time but also greater flexibility to the experimenter in the design stage by allowing for the removal of test units at non-terminal time points. Hence, we first consider the inference for a progressively Type-I censored life-testing experiment with k uniformly spaced intervals. For small to moderate sample sizes, a practical modification is proposed to the censoring scheme in order to guarantee a feasible life-test under progressive Type-I censoring. Under this setup, we obtain the maximum likelihood estimator (MLE) of the unknown mean parameter and derive the exact sampling distribution of the MLE through the use of conditional moment generating function under the condition that the existence of the MLE is ensured. Using the exact distribution of the MLE as well as its asymptotic distribution and the parametric bootstrap method, we discuss the construction of confidence intervals for the mean parameter and their performance is then assessed through Monte Carlo simulations. Next, we consider a special class of accelerated life tests, known as step-stress tests in reliability testing. In a step-stress test, the stress levels increase discretely at pre-fixed time points and this allows the experimenter to obtain information on the parameters of the lifetime distributions more quickly than under normal operating conditions. Here, we consider a k-step-stress accelerated life testing experiment with an equal step duration τ. In particular, the case of progressively Type-I censored data with a single stress variable is investigated. For small to moderate sample sizes, we introduce another practical modification to the model for a feasible k-step-stress test under progressive censoring, and the optimal τ is searched using the modified model. Next, we seek the optimal τ under the condition that the step-stress test proceeds to the k-th stress level, and the efficiency of this conditional inference is compared to the preceding models. In all cases, censoring is allowed at each change stress point iτ, i = 1, 2, ... , k, and the problem of selecting the optimal Tis discussed using C-optimality, D-optimality, and A-optimality criteria. Moreover, when a test unit fails, there are often more than one fatal cause for the failure, such as mechanical or electrical. Thus, we also consider the simple stepstress models under Type-I and Type-II censoring situations when the lifetime distributions corresponding to the different risk factors are independently exponentially distributed. Under this setup, we derive the MLEs of the unknown mean parameters of the different causes under the assumption of a cumulative exposure model. The exact distributions of the MLEs of the parameters are then derived through the use of conditional moment generating functions. Using these exact distributions as well as the asymptotic distributions and the parametric bootstrap method, we discuss the construction of confidence intervals for the parameters and then assess their performance through Monte Carlo simulations. / Thesis / Doctor of Philosophy (PhD)