Master of Science / Department of Civil Engineering / Robert J. Peterman / An experimental testing program was conducted at Kansas State University (KSU) to test the bond characteristics of various 5.32-mm-diameter steel wires and smaller diameter (less than 0.5 in.) strands used in prestressed concrete railroad ties. A total of 13 wires and six strands produced by seven different steel manufacturers were used during this testing. Since no wire bond pullout test currently exists, one was developed and its validity tested. This un-tensioned pullout test could serve as a quality control test similar to the standard test for strand bond (ASTM A1081) that has been developed for pretensioned strands. This strand test is currently not verified for strands less than 0.5-in. in diameter, so the procedure was also scrutinized using strands common in the concrete railroad tie industry. Some of the wires and strands contained surface indentations. It is generally accepted that indentations in the reinforcements improve the bond between the steel and concrete. To further complicate the issue, reinforcements with different surface conditions (rust, oils, lubricants) are allowed to be used in the concrete ties which further affects the bond quality of the reinforcements. However, no standardized indentation patterns (shape, size, depth of indent, etc.) or surface conditions (degree of rusting, amount of surface lubricants, etc.) are utilized by all wire and strand manufacturers. Thus, the corresponding bond behavior of these different reinforcements when placed in various concrete mixtures, in terms of average transfer lengths and typical variations, is essentially unknown. The purpose of this testing program was to develop (in the case of wires) or verify/develop (in the case of strands) a pullout testing procedure predictive of the reinforcement’s bond performance in a prestressed application. The test should be relatively inexpensive, demonstrably repeatable, and easily reproducible. Results from the un-tensioned pullout tests were compared to transfer length measurements from accompanying pretensioned concrete prisms in the lab. Additionally, pullout tests and transfer length measurements were obtained at an actual concrete railroad tie manufacturing plant. The obtained data was compared to the lab data and analyzed to further understand the relationship between un-tensioned pullout tests and pretensioned concrete members.

Doctor of Philosophy / Civil Engineering / Robert J. Peterman / A study was conducted to determine the effect of different concrete properties and prestressing steel indentation types on development length and flexural capacity of pretensioned members. Wires and strands commonly used in the manufacturing of prestressed concrete railroad ties worldwide were selected for the study. Thirteen different 5.32-mm-diameter prestressing wire types and six different strands (four, seven-wire strands and two, three-wire strands) were used to cast prisms with a square cross section. The ratio of concrete to prestressed steel in the test prism’s cross section was representable of typical concrete railroad ties. Thus, geometrical and mechanical properties of test prisms were representative of actual ties in the railroad industry. To understand the effect of concrete-release strengths and slumps on development length, all parameters were kept constant in the prisms except concrete-release strength and slump. To manufacture prisms with different release strengths, all four wires/strands were pulled and detensioned gradually when the concrete compressive strength reached 3500 (24.13 MPa), 4500 (31.03 MPa), and 6000 (41.37 MPa) psi. To determine the effect of different slumps on development length, prisms with different slumps of 3 in. (7.6 cm), 6 in. (15.2 cm), and 9 in. (22.9 cm) were manufactured and all other parameters were kept constant in prisms. All prisms were tested in three-point bending at different spans to obtain estimations of development length based on type of reinforcement, concrete-release strength, and concrete slump. Lastly, a design equation was developed based on experimental data for prediction of development length. In the last phase of load tests, cyclic-loading tests were conducted on the prisms manufactured with wires to evaluate the bond performance of wires with different indentation types under cyclic loading. A total of 210 load tests, including 14 cyclic tests, were conducted. The monotonic-load tests revealed a large difference in the development length of pretensioned concrete members manufactured with different wire/strand types and different concrete-release strengths. Also, the cyclic-load tests revealed a significant difference in bond performance of different wire types under cyclic loading compared to monotonic loading.

A travers l'étude de l'engagement étudiant au sein d'un parti politique libanais, le Courant patriotique Libre (CPL), ce travail explore les dynamiques de production de l'attachement et de constitution des groupes sociaux au sein d'une société plurielle. Un groupe peut être heuristiquement défini dans une perspective cognitive et performative: le sentiment d'appartenance serait construit par et manifesté dans un double processus d'allocation de signification et d'incarnation d'un rôle dans les interactions. A cet égard, la narrativité, parce qu’elle est à la fois action de mise en représentation et assignation de sens, constitue un des modes de construction et de réalisation privilégiés du lien social. Dans la société plurielle libanaise, appartenir à un groupe partisan signifie rejoindre une communauté d'interprétation, au sein de laquelle il est possible de distinguer analytiquement trois dimensions du processus de socialisation, recourant chacune à un ressort narratif: la médiation, l'incorporation, et l'intégration. Le détour par l'analyse de la narration de l’attachement permet ainsi de dégager les caractéristiques du lien partisan dans le Liban pluriel contemporain, fondé sur l'affactivité et l'activation de frontières identitaires produites dans et par l'interaction. / "A Recited Community: Figures of an Identity Foretold" looks at the processes of social identification among the youth in plural Lebanon. Ravaged by a fifteen year civil war between 1975 and 1990, this small Middle-Eastern country has become the symbol of divided societies. Through the exploration of student activism in a political party, the Free Patriotic Movement (FPM), the book questions the dynamics of attachment, conflict, and reconciliation in a shattered country. Using original material collected during several years of fieldwork conducted in three of Beirut’s main universities, the author examines the importance of narratives inherited from the past to make sense of social world and sustain one’s sense of belonging. The focus on this narrative construction of group attachment allows portraying of three main features of affiliation in a plural society like Lebanon. First, the mobilization of conflicting storylines that create boundaries and mediate the relation of the individual with the others in the time and space of social interactions. Then, the incorporation of institutionalized collective tales and practices as modes of representation of reality. And finally, the integration of the self in the horizon of a collective memory that allows the insertion within a common emplotment of the multiplicity of members’ biographical experiences into a shared depiction of the past conflicts. Mediation, incorporation, and integration all emerge from and actualize the duality between ipseity and alterity, reminding us that the other is the condition of recognition, thus of existence, of the self.

Nesta dissertação, as alças de içamento de lajes pré-moldadas utilizadas em obras residenciais foram caracterizadas e ensaiadas à tração com o propósito de integrá-las ao sistema produtivo que conta com as lajes devidamente empilhadas no canteiro de obra e içadas ainda jovem até o pavimento. O centro de carga devido aos pontos de içamento deve coincidir com o baricentro da laje e o conjunto de pontos deve resistir aos esforços solicitantes, que no presente trabalho, destacam-se os momentos fletores máximos e punção em cada ponto. A segurança estrutural quanto à flexão foi avaliada pela resistência dos materiais, com base na flexão simples, e pela proposta de bielas e tirantes através da treliça 45º proposta por Morsch e que também foi utilizada para determinar a carga máxima a partir das tensões de tração na superfície cônica próxima ao ponto de içamento na tentativa de relacioná-la às cargas de punção calculadas por equações obtidas de normas, como ACI 318 e NBR 6118, e equação de resistência à carga de punção proposta por Muttoni em 2008. / In this research, the metallic inserts in concrete precast slabs to lift up, which are useful in residential buildings and this lifting system was characterized and took at evaluable of strength at pull-out testing with the purpose of integration into the productive system which contain the precast slabs produced in construction site. The loading center of group lifting inserts may coincide with center of mass in the slab and the set should resist efforts such as bending of the slab and punching shear at each lifting handle. The structural safety of concrete over bending has been evaluated by flexural stress on the across section no cracked concrete and also strut and tie model proposed by Morsch and which model has been suggested to determine the punching shear load on conical surface near by lifting insert in the precast concrete slab and compare with some codes, such as ACI 318 and NBR 6118, also Muttoni\'s punching shear load equation of 2008.

[pt] O hospital de emergência constitui-se para o morador de rua o principal meio de acesso ao sistema de saúde. Este estudo, propõe-se a conhecer os contornos que envolvem o atendimento nestas unidades de saúde. A problematização da questão foi delineada a partir da análise das relações desenvolvidas no âmbito institucional e da fragilização dos ví­nculos sociais. Retrata-se este encontro em trás momentos significativos: admissão, permanência e alta hospitalar. A fundamentação teórica deste trabalho buscou situar os moradores de rua em uma perspectiva histórica e não circunstancial, objetivando compreender a representação social que incorporam. As principais categorias de análise utilizadas para o estudo são a exclusão social e o estigma, por serem conceitos definidores e pertinentes à condição de morador de rua que se configura naquele outro que não queremos ver, sentir o cheiro ou tocar. A partir de entrevistas realizadas junto a moradores de rua hospitalizados e a profissionais da área da saúde, observamos que muitos são os conflitos que permeiam seu percurso em busca de atendimento. / [en] The hospital emergency is for the residents of the street as the main means of access to the health system, therefore, this study proposes to know the contours involving this service. The problematization of this issue was outlined from the analysis of the relationship developed under institutional and weakening of social ties. This research describe this meeting in three significant moments: admission, hospital stay and medical release. The theoretical foundation of this study sought to locate the residents street in a historical perspective and not circumstantial, to understand the social representation incorporating. The main categories of analysis used for this study are social exclusion and stigma because they are defining concepts and relate to the condition of living on the streets. From interviews with residents of the street hospitalised and health care professionals, the conclusion is that many are the conflicts that permeate the journey made by residents of the street in search of care. The resident of the street set up in other that we do not want to see, smell or feel the touch.

Thesis advisor: PhiliP G. Altbach / Today the diaspora option is seen as an important strategy for decreasing the adverse impacts of brain drain. Chinese academic diasporas have increasingly begun to create academic ties with China, yet few studies have examined Chinese academic diasporas' scholarly ties with China. The purpose of this research study is to explore why and how Chinese academic diasporas develop their academic ties with China. In this study, 20 Chinese overseas scholars in the northeastern United States were interviewed. Grounded theory was employed to analyze the interview data. A spectrum of issues and topics, in the narratives of academic ties of Chinese overseas students, emerged from this study. Generally, the interviewed scholars had established active academic ties with the Chinese academic community. These academic ties mainly transferred three types of knowledge: network-building knowledge, outcome-oriented knowledge, and context-oriented knowledge. The intensity of academic ties was found to highly associate with the types of knowledge that were transferred. Academic ties were categorized into three modes: radio mode, outsourcing mode, and constructional mode. While radio and outsourcing modes have a separate process of producing and transmitting knowledge, Chinese academic diasporas and their Chinese counterparts can equally collaborate to create new knowledge in a constructional mode. This study found that cultural identity and academic identity influenced the scholars' motivations for maintaining academic ties with China and shaped the intensity of their academic ties. Finally, this study suggests that Chinese academic diasporas play a crucial role in communicating western values and norms with the Chinese academia and society via their scholarly ties with China. Limitations of this study include small sample size and distribution. Recommendations for future study include increasing sample size, recruiting more female participants, examining scholars from non-research universities and from other regions of the United States, and investigating how social values impact academic ties. / Thesis (PhD) — Boston College, 2009. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Administration and Higher Education.

Social connections represent an important determinant of economic agents’ behaviour. The three chapters of this thesis empirically analyse the effect of different types of networks on several economic outcomes. The first chapter analyses the role played by co-worker networks on immigrants’ employment outcomes. It investigates how immigrants’ job search outcomes are affected by the labour market outcomes of co-workers from the same country of origin. Using matched employer-employee micro data from Italy and an instrumental variables approach, I show that an increase in the employment prospects of socially connected workers improves immigrants’ job search outcomes. The paper also sheds light on the different mechanisms generating the social effect and it highlights the role of migrant networks in explaining immigrant segregation. Chapter 2 employs a unique dataset on articles, authors and editors of the top four economics journals over the period 2000-2006 to investigate the role of social ties in the publication process. Connections between editors and authors are identified based on their academic histories. Regression results show that the existence of a social tie with an editor positively affects publication outcomes of connected scholars. The analysis of citations shows that connected articles receive on average a higher number of citations than non-connected ones. The final chapter focuses on the impact of female managers on female workers’ employment outcomes. Exploiting changes in the share of female managers induced by firms’ takeovers, I find no statistically significant effect of an increase in the presence of female managers on employment outcomes of female workers. However there is an interesting negative effect on wage inequality within the acquiring firm, which may matter for both equity and efficiency reasons.

The purpose of the following essay is to study and explain how young adults use their social networks when it comes to finding a job. This study was conducted using nine semi-structured interviews with young adults with some form of employment. We used Granovetter’s theory about strong and weak ties, Bourdieu’s capital theory, Lin’s social reources theory and Putnam’s reasoning about generalized reciprocity. The result shows that social capital is a decisive factor in how young individuals use their social contacts. The volume of social capital is determined by economic resources, social background and the size of the social network. Less resourceful groups have a tendency to take advantage of the strong ties, i.e. family and relatives, often when looking for their first job. The weak ties, i.e. acquaintances, are used later in life when the individual has greater resources and networks. Individuals from the privileged groups may not always be able to work on their parents’ company as a first job, because they might require certain qualifications to do so. However, these job positions become possible for the young individuals from resourceful groups when they accomplish a relevant education. That's when they get the chance to use the resources that are embedded in their strong ties.

This thesis aims to investigate how, and under what circumstances, intimacy in grandparent-grandchild relationships is enabled, enacted and sustained in the early years of grandchildren. Previous work on emotional closeness of grandparent-grandchild relationships suggests that grandmothers and maternal grandparents are more likely to feel stronger bonds with their grandchildren, and that grandparents with a good quality of relationship with parents and living geographically close to grandchildren have greater opportunities to develop a strong emotional tie. The majority of previous research involves data on perceptions of closeness of grandparents focusing on one of their grandchildren or by young adult grandchildren reporting on closeness with a specific grandparent. In addition, qualitative research with grandparents indicates the diversity of ways they exercise agency, and involvement in the life of grandchildren, as well as gendered changes in grandfatherhood. However, there has been limited scholarly attention given to practices of intimacy, emotions and masculinities in grandparent-grandchild relationships, and the ways grandparents interpret and negotiate intimate relationships with their grandchildren amid changes in individual, familial and relational aspects over time. This study uses quantitative data to examines the extent to which individual, family and socio-structural factors influence the mothers' perception of emotional closeness of the relationship of an infant child with four types of grandparents. This is supplemented by qualitative data on grandparents' views of closeness with all their grandchildren. There is a limited scholarly literature on the relation of grandparents' lived experiences, and shared normative understandings, and a sense of being close and special to their grandchildren. The 'practices of intimacy' approach highlights the significance of practices of everyday life enacted by individuals in relation to others in building the quality of being close, and the processes through which individuals attach meaning to such practices. This approach is adopted to understand the diversity of ways grandparents interpret and do intimacy with their grandchildren. The thesis aims were achieved through a mixed methods research process combining secondary data analysis of the Growing Up in Scotland (GUS) study and in-depth interviews with 24 cases of grandparents (12 solo, either with a grandmother or grandfather, and 12 with couple). GUS maps the emotional closeness of grandchild-grandparent relationships through the grandchild's mother's perception. Analysis revealed that perceived emotional closeness was more likely if the grandparent had social contact with the mother, lived geographically close, and looked after and engaged in outings more regularly with the infant child. In general, social contact and propinquity impacted less on grandmothers, particularly maternal grandmothers, and more on paternal grandfathers. Also, looking after grandchildren on a regular basis was distinctly salient for grandmothers, whereas going more frequently on outings was more salient for grandfathers than grandmothers. As regards practices of intimacy, grandparents emphasised the importance of communication through verbal, bodily and relational forms enacted through a large variety of activities in the daily living related to forms of caring, playing and spending time together, which construct a sense of emotional closeness. The study suggests that intimate grandparent-grandchild relationships are intersected by moral understandings of 'good grandparenting', which are challenged or find contradictions in lived experiences of grandparenting that produce asymmetrical emotionalities among grandchildren, and ambivalences in relation to children and grandchildren. The study suggests that grandparents reflect on their emotionality, and enact embodied emotions, depending on relational and family circumstances, and throughout changes in the relationship with their grandchildren as they get older. The study shows that grandfathers engage in emotional forms of caring, which may challenge hegemonic masculinities, and that the relation between masculinities and practices of intimacy are troubled, particularly in the event of parental divorce.

Does social similarity between the auditor and a specialist induce social biases that impair the auditor's reliance on the specialist? It is important to examine potential impairments to reliance since auditors do not possess expertise in many of the areas examined during the audit. One type of specialist that is increasingly relied upon by the auditor is the IT specialist. Since firms have two approaches to the organization of IT personnel (decentralized vs. centralized) and often use professional designations as a hiring criteria for specialists, I examine two dimensions of social similarity: domain knowledge distinctiveness and spatial distance. Using a 2 × 2 experiment manipulating the IT specialist's domain knowledge distinctiveness (distinct vs. overlapping) and spatial distance (in-house office location vs. outsourcing from another office) relative to the auditor, I investigate financial auditors' reliance on IT specialists. My findings provide evidence of a boundary condition to the widely accepted social identity theory. Specifically, when specialists (IT specialists in this study) are outsourced, marginally less reliance is placed on specialists possessing overlapping (shared) domain knowledge relative to distinct domain knowledge. Additionally, I find evidence of a "consultant effect" in which greater auditor reliance is placed on IT specialists from other offices when the IT specialist possesses distinct domain knowledge relative to the financial auditor. Findings suggest that a broader theory of social similarity in which dimensions of social similarity can interact to produce social biases appears to be more descriptive of real-world social complexities than social identity theory.