Zugl.: Mainz, Univ., Diss., 2009

No description available.

Biomaterials is a systematically, pharmacologically inert substance designed for implantation within or incorporation with a living system. The ultimate goal of biomaterials is to restore function of living tissues and organs of the body. Chemical stability, mechanical behavior and biocompatibility in body fluids and tissues are basic requirements for successful application of implant materials in hip replacements. The field of biomaterials has become a vital area, as these materials can enhance the quality and longevity of human life and the science and technology associated with this field has now led to multi-million dollar business. The thesis focuses mainly on fractured analysis of retrieved titanium-alloy modular hip implants, even though there exists biomaterials made up of ceramics, polymers and composite materials As it is well known that a good biomaterial should possess the fundamental properties such as better mechanical and biological compatibility and enhanced wear and corrosion resistance in biological environment. The primary purpose of this thesis was to identify the reasons which lead to fracture of implant retrieved from 60years old male implanted for a 16 month time. The retrieved Implant was sterilized for two hours to overcome bio hazardous condition. The fractured area of implant sleeve and stem was cut with help of machine ISOMET BUEHLER 4000 consisting of diamond saw. The cut sample was placed into physiological solution (0.9% NaCl in H2O), and was maintained at room temperature over night. Samples were then thoroughly brushed with help of toothpaste and tooth brush to get rid of tissue deposits and blood stains so as to get clear picture under SEM. Fractures sample was than observed under Scanning Electron Microscope and a detailed study revealed fretting corrosion and fatigue failure were main cause of implant failure. After examining under SEM, sample was than prepared to be polished by covering it with epoxy and using BUEHLER polishing machine and sand paper from 240-1200 grid and finally a micro cloth to smoothen the surface. After sample being polished, it was immersed in Kroll solution for etching and observing under microscope to figure micro-structural changes.

vii, 41 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / The purpose of this study was to identify and define the essential characteristics of hip hop dance. Hip hop dance has taken many forms throughout its four decades of existence. This research shows that regardless of the form there are three prominent characteristics: performance, personal style, and competition. Although it is possible to isolate the study of each of these characteristics, they are inseparable when defining hip hop dance. There are several genre-specific performance formats in which hip hop dance is experienced. Personal style includes the individuality and creativity that is celebrated in the hip hop dancer. Competition is the inherent driving force that pushes hip hop dancers to extend the form's physical limitations. Defining these vital characteristics in the vernacular context should help dancers, scholars, and educators to develop a better understanding of hip hop dance. / Committee in Charge: Jenifer P. Craig Ph.D., Chair; Steven Chatfield Ph.D.; Christian B. Cherry MM

Made available in DSpace on 2014-06-12T16:30:30Z (GMT). No. of bitstreams: 2 arquivo860_1.pdf: 3533003 bytes, checksum: 268883a20745ad2701f1fe6b8cbbb475 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / O presente trabalho se propõe a analisar as relações que a(s) juventude(s) possuem com o espaço periférico. Para isso, escolheu-se, como facilitador dessa análise, uma Rede que está presente ao menos esteve inicialmente, podendo ter muito mais hoje em cinquenta e uma comunidades da Região Metropolitana do Recife (RMR). Essa Rede uniu-se com o objetivo de articular grafiteiros(as) da RMR para pautar propostas para articulação nas comunidades periféricas, na perspectiva de consolidar os grupos enredados nas suas respectivas comunidades. Isso fez com que os grupos se fortalecessem. Com cinco anos de atuação, fora o período de diálogo e articulação, a Rede passa a ser maior que seu próprio nome e as atividades passam a ser apropriadas e requisitadas por grupos que não fazem (ou não faziam) parte da Rede, na tentativa de buscar uma interação maior com a própria comunidade, utilizando a linguagem do Hip Hop como instrumento possibilitador dessa aproximação. Além disso, a Rede deixa de ser exclusivamente de grafiteiros(as), passando a se integrarem médicos, profissionais de comunicação, pessoas de outros movimentos sociais, outros artistas etc. Para compreender esse universo, foi preciso compreender processo histórico ocidental na perspectiva de entender a invenção da juventude , sua participação na sociedade e no próprio processo de desenvolvimento , tanto na América Latina quanto no Brasil. Nessa tentativa de analisar os processos sociais de organizações de minorias étnicas, classes sociais desprivilegiadas foi necessário, quando possível, fazer suas relações com o processo de escravidão, principalmente no que diz respeito ao século XVIII e XIX. Isso porque, o Hip Hop tem suas raízes na década de 40 do século XX, na Jamaica, influenciado pelos sound sistems que eram equipes de som com vários componentes, entre eles os DJ's e os toasters (antepassados diretos dos Mestres de Cerimônia - MC's). Esse consistiu um período marcado pela reestruturação e reprodução das relações coloniais e de exploração. É nesse emaranhado de relações opressivas que surge o Hip Hop, na década de 1970, nos EUA, influenciado e organizado por imigrantes jamaicanos naquele país, expandindo-se para o mundo, tomando diversas formas e sentidos

Acetabular labral tears are associated with hip osteoarthritis. A current surgical treatment strategy for a torn labrum, labral resection, has recently shown poor patient outcomes with radiographic signs of osteoarthritis two-years post-operation. Since mechanical factors play a role in the etiology of osteoarthritis, identifying the mechanical role of the labrum may enhance current surgical treatment strategies. In this pilot study, we assessed the relationship between mean cartilage strain, maximum cartilage strain and the three-dimensional cartilage strain distribution in six human cadaver hips with various pathologic conditions of the labrum. We developed a novel technique of mapping cartilage strain using quantitative magnetic resonance imaging (qMRl). qMRl provides a non-invasive means of quantifying the cartilage strain distribution in the hip in three dimensions. Each specimen was assessed first with an intact labrum, then after surgically simulating a longitudinal peripheral labral tear, then after arthroscopically repairing the tear, and after labral resection. We validated the precision of the technique through use of an additional specimen which served as a control. To minimize motion artifact in the high-resolution MR images, we determined that 225 minutes was required for cartilage to reach a steady-state thickness under load. We also determined 16.5 hours was required for cartilage to recover to a steady-state unloaded thickness. The difference in mean and maximum cartilage strain when the labrum was repaired and resected was assessed using a paired t-test. We found that the resected group had an increased mean and maximum cartilage strain of 4% and 6%, respectively and the 3D cartilage strain distribution was elevated throughout the region of interest. When the condition of the intact labrum was compared to the torn labrum, we found no change in mean and maximum cartilage strain, and little obvious change in the 3D pattern of cartilage strain distribution. Based on our findings of increased cartilage strain after labral resection when compared to labral repair, we hypothesize that the labrum’s contribution of additional surface area assists in load distribution, which spares cartilage from excessive loads. We therefore recommend that the longitudinal peripheral torn labrum should not be resected if it is possible to be repaired, because in vivo, labral resection may create an environment with increased articular cartilage strain, which is thought to be associated with cartilage degeneration. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

Metal on metal (MoM) hip replacements consist of a cobalt-chromium-molybdenum alloy femoral head which articulates against an acetabular cup manufactured from similar material. MoM hip replacements were introduced in the 1980s. It was thought that the overall reduction in volumetric wear as well as the avoidance of polyethylene would lead to greater longevity of these prostheses. There had been isolated reports of adverse tissue reactions with previous generations of MoM devices but it was thought that improved manufacturing technology would eliminate these problems. In the 1990s, the Birmingham Hip Resurfacing (BHR) was developed. The positive mid-term results of this device led to a rapid increase in the use of the BHR throughout the world. For obvious reasons, the enhanced stability large diameter bearings provided proved extremely attractive to surgeons and patients. Manufacturers therefore began to develop total hip replacement systems for patients unsuitable for the resurfacing procedure. These systems used bearings of size 36mm and greater, in Contrast to the existing 28mm Metasul device. From 2005 onwards there began to emerge increasing numbers of reports of local complications in the tissues adjacent to MoM prostheses. These reactions included sterile masses, tissue destruction and osteolysis. The incidence of these tissue reactions was unknown, as were the risk factors for their development. This piece of work sought to quantity the volumetric and linear wear rates of failed MoM hips and to investigate the relationship these wear rates and a number of clinical parameters. These parameters included blood, serum and hip fluid chromium and cobalt concentrations, and the macro and microscopic appearance of periprosthetic tissue at revision surgery. In this way it was hoped that component design, host and surgical factors leading to adverse tissue reactions could be identified and potentially eliminated.

No description available.

This ethnographic study describes the digital media ecologies of hip-hop artists in the marginalised township spaces of a town in South Africa. It shows how technology appropriation here is highly contextual and linked to social context, while simultaneously informed by limited digital infrastructure that characterises marginalised communities in the Global South. In describing their social context, the study situates these young people in a post-apartheid space of entrenched racialised inequality, where unemployed black youth have very few economic prospects. Here hip-hop offers protection against despair as it allows a young person to claim a dignified sense of self, which is partly constituted through digital media competency. Through the Black Consciousness philosophy, hip-hop artists in Grahamstown become highly critical of self-defeating narratives rooted in racism, colonialism and apartheid, which often manifest in violent forms of urban masculinity. Instead they find ways to "remix" their identities by incorporating alternative notions of a successful self. These new identities foreground agency and competency, and are informed both by knowledge of African tradition and language, and newly acquired competency in entrepreneurship, artistic genres and digital skills. The study argues that acquisition of digital skills in this space is best conceptualised through the community of practice approach, where skills development is social and linked to a sense of belonging and progress. Just as the hip-hop artists claim agency in remixing their notion of self, they also claim agency in remixing the limited digital technology available to them into various assemblages, so crafting innovative solutions to the constraints of limited and expensive digital infrastructure. Here, through a hip-hop culture that champions overcoming adversity, dysfunctional digital technology is constantly repaired and remixed. Hitherto, research on digital media use in the Global South has predominantly focused on the mobile phone in isolation. This study instead argues for the merits of a holistic digital ethnography, since observations of how these young people combine technologies such as mobile phones, computers and DVD players in everyday life, illustrate how innovation in marginalised spaces may be focused around the remixing of technology.

No description available.