Objetivo: Este estudo se propõe a verificar a influência do adesivo, material de preenchimento e hibridização da dentina na força de retenção de pinos intra-radiculares na técnica direta indireta e comparar o teste de tração de push out com o pull out. Métodos: 60 raízes de dentes bovinos com comprimento de 12 mm foram tratadas endodonticamente e divididas aleatoriamente em 6 grupos (n=10): grupo 1 (técnica direta-indireta, adesivo fotopolimerizável, cimento resinoso, teste de pull out); grupo 2 (idem ao grupo 1 porém o cimento resinoso foi substituído pela resina composta); grupo 3 (idem ao grupo anterior porém o adesivo fotopolimerizável foi substituído pelo químico); grupo 4 (idem ao anterior porém o teste utilizado foi o de push out); grupo 5 (idem ao grupo anterior porém o adesivo utilizado foi o auto condicionante); e grupo 6 (idem ao grupo anterior porém a dentina foi pré hibridizada). A força de retenção foi determinada através do teste de tração usando Universal Testing Machine (Instron). Todos os dados foram analisados usando one-way analysis of variance (ANOVA) com a significância de p<0.05 e complementadas com teste de Tukey. Após o teste, as interfaces adesivas onde ocorreram as falhas foram examinadas e classificadas. Resultado: Houve diferença estatística na comparação de materiais (adesivo, material de preenchimento). A hibridização da dentina não apresentou melhoras na retenção dos pinos . A maior parte das fraturas ocorreu na interface dentina/resina. Conclusão: Com base nos resultados obtidos, concluímos que material de preenchimento, o tipo de adesivo, influenciaram na retenção de pinos de fibra; e a pré-hibridização da dentina não apresentou melhoras a retenção dos pinos. O teste de push out apresentou mais detalhes para verificar o valor da adesão de cada terço da raiz; e o teste de pull out, para a força de retenção do pino ao longo do interior do conduto e o tipo de falha. / Objective: The aims of this study is to verify the influence of adhesive, filling material and dentin hybridization on fiber post retention force in diretc -indirect technique and compare the tensile test of push out with pull out. Methods: 60 bovine single roots with a length of 12 mm were endodontically treated and randomly divided into 6 groups (n = 10): group 1 (direct-indirect technique, light-curing adhesive, resin cement, pull out test), group 2 (same as group 1 but the resin cement was replaced by composite resin), group 3 (same as previous group but the light-curing adhesive was replaced by the chemical), group 4 (same as group 3 but the test was used was push out test), group 5 (same as group 4 but the adhesive used was the self etching) and Group 6 (same as previous group but the dentin was pre-hybridized). The retention force was determined by Universal Testing Machine (Instron). All data were analyzed using one-way analysis of variance (ANOVA) with significance of p <0.05 and complemented with Tukey test. After testing, the adhesive interfaces were examined and classifie. Result: There was a significant difference between comparison of materials (adhesive and filling material). The hybridization of dentin showed no improvement in the retention post. Most fractures occurred at the interface dentin / resin. Conclusion: Based on the results, we conclude that filling material, adhesive, influenced the retention of fiber posts, and the prehybridization of dentin did not improve the retention of fiber post. The push out test showed more details to verify the bonding between the post and dentin, and the pull out test for the retention force of the post inside the canal.

Made available in DSpace on 2014-06-12T15:54:43Z (GMT). No. of bitstreams: 2 arquivo77_1.pdf: 2246870 bytes, checksum: dc0d8b4af5863a847c8f8d83e2604644 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco / O biossensor baseado no nanoporo unitário formado pela &#61537;-hemolisina (&#61537;-HL) do Staphylococcus aureus incorporada em bicamada lipídica plana permite a detecção, identificação e quantificação de diferentes compostos em meio aquoso. Os íons em meio aquoso podem causar efeitos específicos conhecidos como efeitos de Hofmeister. De acordo com a sua atuação na estrutura da água, os íons podem ser classificados como cosmotrópicos e caotrópicos. A mudança da estrutura da água por sua vez é capaz de influenciar na solubilidade e estrutura dos co-solutos. Então, a composição iônica da solução pode alterar a interação das moléculas solubilizadas. Este trabalho teve como objetivo investigar a influência de íons monovalentes na interação de moléculas unitárias orgânicas com nanoporos protéicos visando o entendimento dos mecanismos moleculares do processo e o aumento da sensibilidade do sensor. A confecção da bicamada lipídica plana e a inserção do nanoporo unitário na membrana, bem como os registros de correntes iônicas através dos poros foram realizados em condições de fixação de voltagem. No estudo da influência da concentração do eletrólito utilizamos as soluções de KCl em concentrações de 1M à 4M. A comparação dos efeitos dos ânions da família VIIA foi feita com sais de potássio em concentração de 4M e os efeitos dos cátions da família IA mais o NH4 + foram estudados utilizando sais de cloreto (4M). A ligação da molécula unitária (analito) ao nanoporo causa um bloqueio característico na corrente iônica que passa através do poro protéico. A análise desses eventos moleculares (bloqueios) permite determinar as constantes cinéticas da interação analito-nanoporo. Estabelecemos que aumentando a concentração do KCl na solução banhante de 1M para 4M ocorre um aumento na frequência, profundidade de bloqueio e tempo de residência do analito (polietilenoglicol 1294; PEG 1294). Analisando a mudança da frequência dos bloqueios com relação à concentração de KCl, estabelecemos que a concentração do analito detectável pelo sensor diminui com o aumento da concentração do sal de 1M para 4M cerca de cem vezes, indicando maior sensibilidade do sensor quando banhado por uma solução de KCl 4M. O forte aumento no tempo de residência do analito dentro do nanoporo ocorre devido ao aumento da energia de interação do complexo analito/nanoporo. A constante de associação do complexo PEG/nanoporo é cerca de cem vezes maior e a constante de dissociação é cerca de cem vezes menor em KCl 4M do que em KCl 1M. Essas mudanças melhoram a detecção e tornam viável a detecção da molécula unitária. Encontramos que a interação PEG/nanoporo é dependente de voltagem transmembrana indicando que o polímero nãoiônico (PEG) atua como uma molécula com carga elétrica em meio aquoso. Foi visto que a solubilidade do PEG é uma função da concentração do sal também. Uma forte correlação entre as mudanças das constantes e a solubilidade do PEG foi estabelecida. Provavelmente, o efeito salting-out é o responsável por mudanças estabelecidas na interação do analito com o nanoporo. Avaliando a influência dos íons da família IA e VIIA na interação do complexo PEG/nanoporo observamos que esta é muito dependente do tipo do sal. A sensibilidade do sensor depende fortemente do tipo de ânion da solução banhante e na solução de KF 4M é cerca de dez vezes maior e na solução de KI 4M é cerca de dez vezes menor quando comparada com a solução de KCl 4M. Estabelecemos que os valores das constantes de formação do complexo PEG/nanoporo diferem dependendo do tipo do cátion. A solução de KCl teve a maior constante de formação, enquanto que, as soluções de NH4Cl e LiCl tiveram as menores constantes, portanto, evidencia-se que o tipo de eletrólito influencia em todos os parâmetros da interação do analito com o nanoporo. Por isso, a escolha do eletrólito ótimo é uma etapa importante para sensores estocásticos baseados em um único nanoporo

M.A. (Social Science) / The work environment in which social workers are fulfilling their duties are today demanding more and more of them. These demands are different from those demands of other professions and is the result of the distinctiveness of the helping professions. Social workers boast that they are because of their work situation always in a state of emotional exhaustion. To this the literature refers as the burnout syndrome. Articles and research reports on the topic of burnout appeared in the past on a regular basis and are new articles and reports published regularly. A research study was undertaken to determine what the extent of burnout is in social workers and to determine if there are reason for the widespread claims that they are victims of the burnout syndrome. The aim was also to determine those factors that are involved in causing burnout. A literature study were undertaken with the aim to describe the burnout syndrome. The literature showed that burnout is a syndrome characteristic of the helping professions. The literature also describes specific elements by which burnout could be recognised. It further gave some indications of those factors that are instrumental in the development of burnout. A sample were selected, a questionnaire compiled and distributed with the aim to collect information on the appearance of burnout. The results of the study showed different results. The most important result that was established was the lack of high levels of burnout in the sample. Only a small percentage of the respondents displayed high levels of burnout. The results also indicated that work dissatisfaction, a lack of autonomy, role problems (role conflict and role ambuguity) related to high levels of burnout. A sample were selected, a questionnaire compiled and distributed with the aim to collect information on the appearance of burnout. The results of the study showed different results. The most important result that was established was the lack of high levels of burnout in the sample. Only a small percentage of the respondents displayed high levels of burnout. The results also indicated that workdissatisfaction, a lack of autonomy, role problems (role conflict and roleambuguity) related to high levels of burnout in respondents. The results of the study led to certain recommendations concerning the prevention of burnout in social workers.

Since colonization, Indigenous women in Chiapas have occupied very disadvantaged social positions, characterized by ethnic, gender and class-based oppression. However, during the last thirty five years, important social dynamics have taken place which have driven women to perceive themselves as the main actors of social transformation, and to start participating in planning and development efforts at a household and community level. Building on the ideas of Paulo Freire and Pierre Bourdieu, oppression is understood as a dynamic where the oppressed are also implicated by, among other things, the involuntary body adhesion to oppression, experienced as shame, fear and silence. Therefore, the main focus of this research is the processes by which women achieved to exercise the internal capability to speak out; as well as how this new ability has been critical in order to have transformative agency, by having a meaningful participation in planning, agency and decision-making in the different spheres of their private and public life. The main findings of this thesis arise from six month of field research. With a phenomenological and hermeneutic approach, seventeen Indigenous and ten non-Indigenous women participated through in-depth interviews and focus groups. Participatory observation and a validation workshop were also undertaken. Findings are related, first, to women’s participation in group processes, by which, on the one hand, they achieved to generate critical-reflective awareness, denaturalizing oppression, and, on the other hand, they removed embodied oppressive dispositions by retraining their bodies through dialogue and corporal techniques. Second, praxis of liberation aroused from reflection, with no need of a mechanistic plan informed by efficient and effective predetermined justifications. Praxis of liberation took the form of practical wisdom and wise judgment for the achievement of good life. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

Abstract Ciprofloxacin was incorporated to plain bioresorbable self-reinforced polylactide/glycolyde 80/20 screws and tacks (ciprofloxacin releasing SR-PLGA). These implants were compared to otherwise similar conventional fixation devices. The effect of the ciprofloxacin addition on the pull-out force of screws and tacks was evaluated in human cadaver cranial bones. SR-PLGA tacks applied to cranial bone with a special applicator gun had a similar holding power as screws. Addition of the antibiotic compromised the strength of the screws so that ciprofloxacin-containing PLGA screws had lower pull-out strength than corresponding plain PLGA screws. Scanning electron microscopy showed that the fibrillar strip-like microstructure of plain SR-PLGA screws turned into a coarse uni-axial platelet-like pattern as a result of ciprofloxacin addition. It is concluded that this type of 4 mm long and 1.5 mm diameter ciprofloxacin-containing screws can only be used in non-load-bearing or slightly load-bearing applications. Tissue reactions elicited by plain bioresorbable self-reinforced polylactide/glycolide (SR-PLGA) 80/20 screws were compared to similar but ciprofloxacin-releasing SR-PLGA fixation devices in rabbit cranial bone. Plain and ciprofloxacin-PLGA 80/20 screws elicited only mild inflammatory reactions upon implantation in rabbit cranial bone, but they did not interfere with osteoblast activity in up to 72 week long follow-up. Release of the antibiotic from ciprofloxacin-PLGA screws was gradual and the drug concentration in bone tissues was still higher at 8 weeks than the minimal inhibitory concentration (MIC) of ciprofloxacin for S. aureus (0.1–1.0 μg/g). Ciprofloxacin-releasing SR-PLGA screws can find clinical usage in the prevention of implant-related infections in osteofixation in craniomaxillofacial bones in non-load-bearing or slightly load-bearing applications. Larger 6 mm long and 2 mm diameter ciprofloxacin-releasing tacks had a similar holding power to cranial bone as conventional tacks. Tacks can be recommended for clinical use as the application procedure saves time and costs.

This Dissertation describes how I used a three nanograting Mach-Zehnder atom beam interferometer to precisely measure a wavelength of light, known as a tune-out wavelength, that causes zero energy shift for an atom. I also describe how such measurements can be remarkably sensitive to rotation rates. It is well known that atom interferometry can be used to measure accelerations and rotations, but it was a surprise to find out that tune-out wavelength measurements can under certain conditions be used to report the absolute rotation rate of the laboratory with respect to an inertial frame of reference. I also describe how we created conditions which improve the accuracy of tune out wavelength measurements. These measurements are important because they serve as a benchmark test for atomic structure calculations of line strengths, oscillator strengths, and dipole matrix elements. I present a new measurement of the longest tune-out wavelength in potassium, λzero = 768.9701(4) nm. To reach sub-picometer precision, an optical cavity surrounding the atom beam paths of the interferometer was used. Although this improved the precision of our experiment by increasing the light-induced phase shifts, the cavity also brought several systematic errors to our attentions. For example, I found that large ±200 pm shifts in tune-out wavelengths can occur due to the Earth's rotation rate. To solve this problem, I demonstrated that controlling the optical polarization, the magnetic field, and the atom beam velocity distribution can either suppress or enhance these systematic shifts. Suppressing these systemic shifts in tune-out wavelengths is useful for precision measurements used to test atomic structure calculations. By enhancing these systematic shifts, the interferometer can be a gyroscope that utilizes tune-out wavelengths.

M.B.A. / The South African public Higher Education environment has been going through changes during the past five years. Thirty six institutions have been merged and consolidated into twenty three institutions. There is considerable financial pressure on these institutions, and this have an impact on the provision and maintenance of a world class technology environment. This study examines the extent of outsourcing in the public Higher Education environment in South Africa, and determines if the environment is unique. It also looks at the aspect of improving service delivery through outsourcing or co-sourcing. The research was conducted by means of a survey, consisting of two parts, sent to all twenty three institutions. A 70% response was received on the questionnaire. The research survey determined the technology environment, the attitude towards, and the extent of outsourcing within the environment, as provided by the Chief Information Officers / Information Technology directors. The findings indicate that there is an element of uniqueness within the higher education environment, and that the institutions face challenges, specifically with relation to skill shortages. Furthermore, it finds that there are areas where co-sourcing can provide a benefit and assist in alleviating the challenges. The study also identifies various areas of further study.

M.Phil. / The relationship between the Mining House / Owner and Project House can be spectacularly successful for both partners (and has resulted in the emergence of a few successful new project houses and plant operation companies all over the world), but can also be disastrous for both parties, if managed incorrectly. The main requirement for a successful relationship between a Mining- and Project House is that there must be something in it for both parties. This is not only measured in customer perception of value for money (Mining House) and profits by the Project House, but is also affected by mutual respect, the working relationship and the perception that both can profit from the relationship by the following activities: • Procurement of goods and services. • Providing assistance in absorbing and adopting process technologies. • Addressing environmental concerns like Environment Impact Assessment, HAZOP studies as well as disaster management plans. • A project management team who can ensure proper control and timely reporting to the financial institutions, ensuring there are no cost and time overruns. • Provide due diligence in order to assign proper value to the assets, business portfolios, brand equity, technology/product, etc. • For retrofits, revamps, technical/ energy audits, upgrading the processes / quality of product through minimal investment routes. • In ensuring all aspects of quality management right from the concept to commissioning stage, involving corporate commitment to the quality management process enabling the companies to follow good manufacturing practices. • To provide knowledge management services i.e. depth of knowledge rather than the breadth. Until recently, most Mining Houses locked outsourcing in the back room - using it to pass off unimportant functions and processes to competent specialists so that managers could focus on more critical activities and core business. This is all changing as outsourcing is increasingly making its way into executives' strategic toolkits. In other research studies [5; C; K; N] three types of outsourcing relationships have been identified namely conventional, collaborative and (business) transformational outsourcing. Mining Houses can use conventional outsourcing to generate cost efficiencies in support processes. Collaborative outsourcing is used both to upgrade business processes and to provide flexibility to respond to changing business needs. Business transformation outsourcing holds a higher standard and is a comprehensive approach to create both new capabilities and to use them to achieve a clear strategic objective.

No abstract available / Dissertation (MA (Practical Theology))--University of Pretoria, 2007. / Practical Theology / MA / unrestricted

For over a century there has been a large ongoing migration from Newfoundland to other parts of Canada and the US. Between 1971 and 1998 alone, net out-migration amounted to 20% of the province’s population. This exodus has become a significant part of Newfoundland culture. While many literary critics, writers, and sociologists have referred to Newfoundland out-migration as a “diaspora,” few have examined the theoretical implications of applying this emotionally charged term to a predominantly white, economically motivated, inter-provincial movement. My dissertation addresses these issues, ultimately arguing that “diaspora” is an appropriate and helpful term to describe Newfoundland out-migration and its literature, because it connotes the painful displacement of a group that continues to identify with each other and with the homeland. I argue that considering Newfoundland a “diaspora” also provides a useful contribution to theoretical work on diaspora, because it reveals the ways in which labour movements and intra-national migrations can be meaningfully considered diasporic. It also rejects the Canadian tendency to conflate diaspora with racialized subjectivities, a tendency that problematically posits racialized Others as always from elsewhere, and that threatens to refigure experiences of racism as a problem of integration rather than of systemic, institutionalized racism. I examine several important literary works of the Newfoundland diaspora, including the poetry of E.J. Pratt and Carl Leggo, the drama of David French, the fiction of Donna Morrissey and Wayne Johnston, and the memoirs of Helen M. Buss/ Margaret Clarke and David Macfarlane. These works also become the sites of a broader inquiry into several theoretical flashpoints, including diasporic authenticity, nostalgia, nationalism, race and whiteness, and ethnicity. I show that diasporic Newfoundlanders’ identifications involve a complex, self-reflexive, postmodern negotiation between the sometimes contradictory conditions of white privilege, cultural marginalization, and national and regional appropriations. Through these negotiations they both construct imagined literary communities, and problematize Newfoundland’s place within Canadian culture and a globalized world. / Arts, Faculty of / English, Department of / Graduate