This thesis deals with receptivity mechanisms of three-dimensional, crossflow-dominated boundary layers. The receptivity of two model problems, a swept-flat-plate and a swept-wing boundary layer, is investigated by solving the parabolised stability equations (PSE) as well as by performing direct numerical simulations (DNS).Both flow cases are known to exhibit strong inflectional instabilities, the crossflow disturbances, whose excitation by external disturbances such as surface roughness or free-stream vorticity is studied. One focus is on worst-case scenarios. This involves the determination of optimal conditions, i.e. those disturbance environments yielding the largest possible response inside the boundary layer. A new method on the basis of the PSE is presented which allows to study optimal disturbances of swept-flat-plate boundary layers. These take the form of tilted streamwise vortices. While convected downstream they develop into streamwise streaks experiencing strong non-modal growth. Eventually, they turn into crossflow disturbances and undergo exponential growth. Non-modal growth is thus found to optimally excite crossflow disturbances and can be related to a receptivity mechanism of three-dimensional boundary layers. Evaluating effects of compressibility reveals that the potential for both non-modal and modal growth increases for higher Mach numbers. It is shown that wall cooling has diverse effects on disturbances of non-modal and modal nature. While destabilising the former it attenuates the growth of modal disturbances. Concave curvature on the other hand is found to be equally destabilising for both types of disturbances. The adjoint of the linearised Navier-Stokes equations is solved for a swept-wing boundary layer by means of DNS. The adjoint solution of a steady crossflow disturbance is computed in the boundary layer as well as in the free-stream upstream of the leading edge. This allows to determine receptivity to incoming free-stream disturbances and surface roughness as well as the corresponding worst-case scenarios. Upstream of a swept wing the optimal initial free-stream disturbance is found to be of streak-type which convects downstream towards the leading edge. It entrains the boundary layer a short distance downstream of the stagnation line. While minor streamwise vorticity is present the streak component is dominant all the way into the boundary layer where the optimal disturbance turns into a crossflow mode. Futher, the worst-case surface roughness is determined. It takes a wavy shape and is distributed in the chordwise direction. It is shown that, under such optimal conditions, the swept-wing boundary layer is more receptive to surface roughness than to free-stream disturbances. Another focus of this work has been the development and evaluation of tools for receptivity prediction. Both DNS and direct and adjoint solutions of the PSE are used to predict the receptivity of a swept-wing boundary layer to localised surface roughness. The configuration conforms to wind tunnel experiments performed by Saric and coworkers at the Arizona State University. Both the DNS and the PSE are found to predict receptivity amplitudes which are in excellent agreement with each other. Though the predicted disturbance amplitudes are slightly lower than experimental measurements the overall agreement with experimental results is very satisfactory. Finally, a DNS of the stabilisation of a transitional swept-wing boundary layer by means of discrete roughness elements is presented. This control approach is found to completely suppress transition to turbulence within the domain studied and confirms experimental results by Saric & coworkers. / QC 20111124

The effect of freestream turbulence on generation of crossflow disturbances over swept wings is investigated through direct numerical simulations.  The set up follows  the  experiments  performed  by Downs  et  al.  in their  TAMU  experi- ment.  In this experiment the authors use ASU(67)-0315 wing geometry which promotes  growth  of crossflow  disturbances.   Distributed  roughness  elements are locally placed near the leading edge with a span-wise wavenumber, to ex- cite the corresponding crossflow vortices.  The response of boundary layer to external disturbances such as roughness heights, span-wise wavenumbers, Rey- nolds numbers and freestream turbulence characteristics are studied.  It must be noted that the experiments were conducted at a very low level of freestream turbulence  intensity  (T u).   In this  study,  we fully  reproduce the  freestream isotropic homogenous turbulence through a DNS code using detailed freestream spectrum data provided by the experiment. The generated freestream fields are then applied as the inflow boundary condition for direct numerical simulation of the wing. The geometrical set up is the same as the experiment along with application of distributed roughness elements near the leading edge to precipi- tate stationary crossflow disturbances.  The effects of the generated freestream turbulence are then studied on the initial amplitudes and growth of the bound- ary layer perturbations.  It appears that the freestream turbulence damps out the dominant stationary crossflow vortices. / <p>QC 20130604</p>

One of the last remaining challenges preventing the laminarization of sweptwings is the control of unstable crossflow vortices. In low-disturbance environments the transition from laminar to turbulent flow on the swept-wing initially takes the path of receptivity, where surface roughness or disturbances in the environment introduce shortwavelength disturbances into the boundary layer. This is followed by development and linear growth of stationary crossflow vortices that modify the mean flow, changing the stability characteristics of the boundary layer. Finally, breakdown to turbulence occurs over a short length scale due to the high-frequency secondary instability. The receptivity mechanism is the least understood, yet holds the most promise for providing a laminar flow control strategy. Results of a 3-year flight test program focused on receptivity measurements and laminar flow control on a 30-degree swept-wing are presented. A swept-wing test article was mounted on the port wing of a Cessna O-2A aircraft and operated at a chord Reynolds number of 6.5 to 7.5 million. Spanwise-periodic, micronsized discrete roughness elements were applied at the leading edge of the swept-wing in order to excite the most unstable crossflow wavelength and promote early boundary layer transition. An infrared camera was used to detect boundary-layer transition due to changes in leading-edge roughness. Combined with the IR camera, a new technique of calibrating surface-mounted hotfilms was developed for making disturbance-amplitude measurements downstream of modulated roughness heights. This technique proved to be effective at measuring disturbance amplitudes and can be applied in future tests where instrumentation is limited. Furthermore, laminar flow control was performed with subcritically-spaced roughness. A 100% increase in the region of laminar flow was achieved for some of the conditions tested here.

Doctor of Philosophy / Psychological Sciences / Patrick A. Knight / This study was designed to examine the combined influence of feedback sign (i.e., positive or negative), feedback specificity, and goal orientation on individuals’ receptivity to performance feedback. Performance feedback is an often-prescribed solution to performance problems for both individuals and organizations, but evidence regarding its effectiveness as a mechanism for promoting positive outcomes has been mixed. It has been argued that one reason for the inconsistency in previous research findings may be a failure to adequately account for reactions to feedback (e.g., receptivity). Accordingly, this study focused on a series of variables with the potential to influence receptivity, in pursuit of a more comprehensive understanding of the feedback process. It was expected that individuals with certain achievement goal orientations would be more or less receptive to different characteristics of the feedback itself, and that the nature of the task being performed would further influence their willingness to accept feedback and implement task-relevant behavioral changes. Data were collected from 536 participants via Amazon’s Mechanical Turk marketplace. Participants completed the experiment in an online environment. Each participant was asked to complete a pair of error-detection tasks, focused on either mathematical computations or grammatical accuracy. Conditionally-assigned, fabricated feedback was provided after task performance on the initial trial. Surveys were used to assess goal orientation and feedback receptivity. Results indicated that greater feedback specificity was associated with greater receptivity to feedback. Analysis also revealed that feedback sign, feedback specificity, and goal orientation interact to influence receptivity, such that for performance-oriented individuals, specific positive feedback leads to the highest levels of receptivity and specific negative feedback prompts the lowest levels of receptivity. For mastery-oriented participants, however, specific feedback was associated with high levels of receptivity, regardless of whether that feedback was positive or negative. The results are discussed within the context of relative theoretical perspectives. Practical implications, promising avenues of future inquiry, and strengths and limitations of the research are discussed.

This thesis is an investigation into ambiguity and irony in Kierkegaard’s The Concept of Dread [Begrebet Angest]. The frequent ambiguities in Kierkegaard’s texts have been discussed by several scholars, and Kierkegaard’s interest in irony is evident not only from his master’s thesis On the Concept of Irony, but also from his other texts. The irony in Kierkegaard has especially been expounded on by Roger Poole and Jacob Bøggild, who both consider irony to be at the heart of Kierkegaardian writing. Furthermore, the ambiguity in Kierkegaard can also be considered typical for the existentialist line of philosophy in general. Finally, both of these subjects tie in to the difficult subject of Kierkegaard’s ”indirect communication”, a subject discussed at length by Poole. The investigation falls into three parts. The first part is essentially a preparation: the concepts of ambiguity and irony are introduced, as is their relation to each other, and the discussion of these pertaining to Kierkegaard is paraphrased. An introduction to Kierkegaard’s indirect communicationis also provided. The second part constitutes the main body of the thesis. This part consists of a reading of The Concept of Dread with special attention brought to the ambiguities of this text. These ambiguities are numerous and in most cases fundamental concepts in the book’s line of reason including things such as dread itself, sin, guilt and the demonic. This reading follows the basic layout of the book itself, interspersed with remarks and topics discussed by other scholars, notably Jonna Hjertström Lappalainen and Gordon Daniel Marino. At the end of this part, the ironic readings of Poole and Bøggild are discussed in relation to the more “direct” reading proposed previously. Such readings put even greater emphasis on the ambiguity, as the text in its entirety is ambiguous. The third part is a tentative discussion of the conflicting accounts of Bøggild, Poole and Hjertström Lappalainen, and an attempt at reconciling these into a coherent view of The Concept of Dread. It is argued that ambiguity, while not equatable with indirect communication, is nonetheless a necessary prerequisite for communicating without compromising the individual’s subjective and concrete experience of the human condition. Finally, the Kierkegaardian notion of absolute freedom as discussed by Hjertström Lappalainen is considered in relation to the “existential concepts” fundamental to existentialist philosophy and, once again, the necessity of ambiguity is shown. The task of the ambiguous or ironic text is then to communicate the subjective, that which cannot be grasped in language, making necessary a certain “emptiness” or openness with regards to the central concepts.

L'acquisition du phénotype de la réceptivité endométriale est une étape clé de l'implantation embryonnaire. Dans ce contexte, ce projet vise à mieux cerner les mécanismes moléculaires de la réceptivité endométriale. Des approches globales (transcriptome et protéome), ont été utilisées pour nos activités de recherche et le développement d'outils diagnostiques en AMP. Nous avons déterminé les fonctions d'un de nos bio-marqueurs de la réceptivité endométriale par shARNs, S100A10. L'extinction de S100A10 dans les cellules primaires endométriales affecte la migration, la décidualisation et l'apoptose des cellules endométriales, des fonctions biologiques majeures impliquées dans le processus d'implantation. D'autre part, nous avons implanté notre test d'appréciation de la réceptivité endométriale dans une clinique de fertilité à Montréal et initié une étude prospective clinique de l'évaluation de la réceptivité endométriale en cycle naturel de patientes en attente d'une procédure de FIV/ICSI. De plus, nous avons démontré un effet délétère d'une progestéronémie élevée le jour du déclenchement de l'ovulation sous traitement de stimulation ovarienne sur la transition des profils transcriptomiques des endomètres pré-réceptif et réceptif, suggérant une accélération de la maturation endométriale pendant la phase péri-ovulatoire, sans pour autant affecter la réceptivité endométriale. Enfin, nous avons montré que la réceptivité endométriale des patientes sous traitements hormonaux substitutifs différait de celles en cycle naturel, caractérisée par une altération des voies de signalisation médiée par les récepteurs aux œstrogènes, des membres de la famille VEGF et des intégrines. / The acquisition of the receptive endometrial phenotype is a key step of the embryo implantation. In this context, this project aims to better understand the molecular mechanisms of the endometrial receptivity. Global technologies (transcriptome and proteome) were used for our research and the development of diagnostics tools in assisted reproductive technologies. We determined the functions of one of our endometrial receptivity biomarkers, S100A10, using shRNAs. S100A10 knockdown in primary endometrial cells affected migration, decidualization and apoptosis of endometrial cells, some major biological functions involved in the implantation process. Moreover, we established our test assessing endometrial receptivity in a fertility clinic in Montreal and initiated a prospective clinical study of the evaluation of endometrial receptivity in natural cycle of patients waiting for an ICSI/IVF attempt. Moreover, we demonstrated an alteration of the gene expression shift from the pre-receptive to the receptive stage of the endometrium of patients with elevated serum progesterone level on the day of ovulation induction, suggesting an accelerated endometrial maturation during the periovulation phase, and thus, without affecting the endometrial receptivity. Finally, we demonstrated that the endometrial receptivity of patients under hormone replacement therapy was different from patients in natural cycle, characterised by alternations in the signaling pathways mediated by the oestrogen receptor, VEGF family members and integrins.

La rénovation urbaine dans l'habitat social met en avant de grandes ambitions. Elle revisite par une approche globale les quartiers dits de géographie prioritaire ou de la politique de la ville. Quelles que soient les justifications des intentions et des actions, l'atteinte des objectifs de cette intervention dépend en grande partie des modalités de sa spatialisation et plus précisément de sa territorialisation en référence au corps social existant qu'il convient de valoriser.La phase de conduite de projet, demeure ancrée dans un formalisme. Celui-ci est la conséquence de l'ampleur des objectifs opérationnels, des difficultés de coordination d'actions multipartenariales et du suivi financier. Donc, elle laisse peu de place aux représentations habitantes.Dans notre étude, nous avons démontré la nécessité de mobilisation du concept de réceptivité habitante dans son application en aménagement et particulièrement dans les projets d'habitat social. Nous nous sommes attachés à envisager une méthodologie d'opérationnalisation d'une variable qualitative, la réceptivité habitante, dans la conduite de projet d'habitat social.Pour y arriver, nous nous sommes appuyés en particulier sur l'analyse de la réceptivité à travers le cas de la rénovation urbaine du quartier Saint-Barthélemy III Picon-Busserine. Grâce à l'analyse de contenu, nous avons pu démonter la nécessité de procéder à un tournant vers la réceptivité habitante, comme gage de bonne réception des projets d'urbanisme.Cette étude, dans sa finalité, est une contribution méthodologique dans le champ de la conduite de projet dans les quartiers d'habitat social. Elle insiste sur l'essence même d'un projet, sa bonne réception par les destinataires.Cette thèse interroge l'apport opérationnel des sciences sociales dans le management et la gouvernance des territoires.Mots-clésRéceptivité habitante, territoire, quartier, habitat social, habitants, représentations, politique de la ville, action publique territoriale, rénovation urbaine, management territorial, gouvernance territoriale, parties prenantes. / Urban renewal in social housing areas is in high hopes to revisit through a comprehensive approach to priority neighborhoods said geography and politics of the city. Whatever the justifications intentions and actions, the objectives of this intervention depends largely on the terms of its spatial and more precisely its regionalization in reference to existing social body that should be exploited.This phase of project, through the prism of a formalism induced by the extent of operational objectives, coordination of multi-stakeholder or financial tracking shares, leaving little room for inhabitants representations.In our study, we have demonstrated the need to mobilize the concept of receptivity resident in its application development and particularly in the social housing projects. We endeavored to consider a methodology for operationalizing a categorical variable, the resident receptivity in the conduct of social housing project.To get there, we relied in particular on the analysis of responsiveness through the case of urban renewal of St. Bartholomew III district Picon-Busserine. Through content analysis, we were able to remove the need for a turning resident receptivity as a token of good reception of urban projects.This study, in its finality, is a methodological contribution in the field of project in social housing areas. It emphasizes the essence of a project, its good reception by the recipients.This thesis questions the operational contribution of social sciences in the management and governance of the territories.KeywordsReceptivity resident, territory, neighborhood, social housing, people, representations, urban policy, public territorial action, urban renewal, territorial management, governance planning, stakeholders.

This study was conducted to determine if ordained women clergy experience resistance or lack of receptivity to their appointments. If so, does the resistance more readily occur with churches in a rural area? The focus of the study was women clergy of the Holston Conference of the United Methodist Church. My study reveals there are Methodist women clergy who continue to have churches outright refuse their projected appointments. My study also reveals that this problem is more often found with churches in rural areas where the culture is connected to long-standing scriptural interpretations and traditions that do not theologically and practically view woman as legitimate church leaders. Qualitative research methods were used in conducting this research. Six ordained women clergy women from the Holston Conference were interviewed. Statistical information was obtained from the 2005 Journal of the Holston Conference of the United Methodist Church. I also researched past germane studies.

This study identified the information seeking behavior and networking practices used by members of a specific marginalized population, that of adult female probationers (AFPs) in a rural county in Texas. The study focused on how they seek out information when faced with a self-identified need in their lives. Beyond the basic "food, shelter and clothing" that comes to mind, the respondents find themselves faced with questions not only about the judicial system but also ones involving health care, employment, transportation, child-care, and other. The study utilized a qualitative research approach to gather data about the AFPs' information behavior and networking activities. The AFPs were asked about their information behavior during their time in the judicial system and after that involvement ended, and about their use of three points of information access: personal social network, physical resources, and electronic resources. Data was also gathered from community members (CMs) who have a role either within the judicial system or external to the judicial system. In its findings, the study determined there is no single point of access to a comprehensive listing of resources for the AFPs to utilize, and that AFPs reported seeking information via two ways as based on the type of question being raised. The study found that a hierarchy of needs should include access to the internet, if not an electronic device itself. The study also found there is a strong relationship between an AFP's personal social network and their support system, and that, beyond access to information, there is an element of information receptivity involved with their success. Based upon the insights provided by the AFPs and CMs, the study provides recommendations to improve information dissemination, especially about available resources, and to facilitate AFPs' access to same. With the study's conclusion, a report will be submitted to members of the rural county's judicial system who have stated a strong interest in the study's recommendations for potential implementation.

No description available.