Measurements were made on three forward steps with step height to boundary layer ratio of approximately 3.8%, 15% and 60% and Reynolds number based on step height ranging from 6640 to 213,000. The measurements included mean wall pressure, single and 2 point wall pressure fluctuations, single and 2 point velocity fluctuations and, oil flow visualization. Pressure fluctuation measurements were made 5 boundary layer thicknesses upstream of step to 22 boundary layer thickness (or 600 step heights for smallest step size) downstream of the step. The results show that the steps remarkably enhance the wall pressure fluctuations that scale on the step height in the vicinity of the step and far downstream of the step. The decay of wall pressure fluctuations post reattachment is a slow process and elevated levels can be seen as far as 150 step heights downstream for the mid step size. The enhanced pressure fluctuations come from the unsteady reattachment region on top face of the step which was found to be a strong function of flow geometry and flow parameters such as Reynolds number. The 2 point pressure and velocity space-time correlations show a quasi-periodic structure which begins to develop close to the reattachment and grows in intensity and scale further downstream of reattachment and is responsible for the elevated pressure fluctuations downstream of the step. However, the velocity correlations lack in scale reflecting the fact that large scales reflected in pressure are masked by smaller scales that exist within them. / Master of Science

Recent research have been focusing on supporting teachers in the classroom. Such support has been shown to benefit from the development and employment of teacher-facing analytic dashboards to help them to make fast and effective decisions in regard to the in-class student learning activities. The evolving interest in this field has facilitated the emergence of the Teaching Analytics area of practice and research. However, current research efforts have indicated that the use of such dashboards usually adds another layer to the already dynamic and complex situation for teachers, which can divert their attention and can often be experienced as a disturbing factor in the class. Therefore, it is highly important to examine how such teacher-facing dashboards can be improved from the user experience perspective, in a way that would allow teachers to grasp student learning activities easily and with good perceived usability. The aim of this study is to understand how we can better design teacher-facing dashboards to more adequately support K-12 teachers in their decisions that would provide relevant in-time and student support. The study applies Nielsen's three-round iterative design approach to understand the existing usability problems and further develop the dashboard, originally designed by the company. In order to investigate users’ perceived attitude towards the redesigned dashboard, the final prototype has been evaluated through a Technology Acceptance Model questionnaire and semi-structured interviews with nine participants. As a result, the redesigned teacher-faced dashboard was proven to have a high potential to support teachers’ decisions. The efficiency of the Technology Acceptance Model was verified and put into general context on how tools for teachers should be designed for the usage in the classroom. Additionally, some major challenges for teachers with using external tools during class were discovered and are discussed in the context of a newly designed dashboard. / Befintlig forskning stödjer lärare i klassrummet genom att utveckla analytiska visualiseringsverktyg (a.k.a. dashboards) som lärare kan använda för att fatta snabba och effektiva beslut med avseende på elevernas läraktiviteter. Det växande intresset för detta område har lett till framväxten av Teaching Analytics-fältet inom praktik och forskning. Forskning har dock visat att användandet av dessa verktyg vanligtvis lägger till ytterligare ett lager till den redan dynamiska och komplexa situationen för lärare, vilket kan avleda deras uppmärksamhet och ofta fungera som en störande faktor i klassrummet. Därför är det mycket viktigt att undersöka hur sådana visualiseringsverktyg för lärare kan förbättras ur användarperspektiv, på ett sätt som skulle göra det möjligt för lärare att förstå elevernas läraktiviteter enkelt och med god upplevd användbarhet. Syftet med denna studie är att förbättra användargränssnittet för ett befintligt, så att det på ett mer adekvat sätt kan stödja lärare i sina beslut och erbjuda relevant stöd till eleverna. Studien tillämpar Nielsens tre-rundors iterativa designmetod för att förstå de befintliga användbarhetsproblemen och vidareutveckla en existerande dashboard, ursprungligen utvecklad av företaget. För att undersöka användarnas inställning till det omdesignade verktyget har den slutliga prototypen utvärderats genom ett frågeformulär och semistrukturerade intervjuer med nio deltagare. Resultat visar att det omdesignade de verktyget har en stor potential för att stödja lärarnas beslut i klassrummet. Effektiviteten för Teknik Acceptant Modellen (TAM) verifieras och sattes i allmän kontext för hur olika verktyg för lärare bör utformas för användning i klassrummet. Dessutom diskuteras lärarnas stora utmaningar med att använda externa verktyg under lektioner i samband med ny verktyget.

The university sector at the beginning of the 21st Century is shifting in response to national and global changes in the role and purpose of Higher Education. Some universities, including the University of Hertfordshire, have chosen to focus attention on engagement with business and commerce. This practice based research examines the experience of academics in relation to the new challenges posed by this strategic development. There are three threads of investigation; interviews, examination of key concepts and the practitioner dimension. Drawing on a qualitative and constructivist approach, individual interviews with a range of business facing academics explore their experience of engaging with new activities. My perspective, as a manager of business facing academics, provides an important thread and situates the work firmly in the practice context. The implicit expectations arising from strategic positioning as a business facing university are examined. A conceptual framework is established with a focus on the nature of business facing activity, including its relationship with traditional forms of teaching and research, learning through work in the Higher Education setting and the idea of an enabling local context. The research found that amongst those undertaking business facing activity, academic identity is a fluid and multi-faceted construct reconfigured through experience and learning in the workplace; by its nature not easily defined, labelled or bounded. The challenge for universities is to nurture and sustain individuals in the creation and use of academic identities, in order to meet the undoubted challenges to come. This requires a forward looking, inclusive and innovative stance, resisting the temptation to judge current academic identities by the established notions of the past. Management of academics involved in business facing activity requires a more flexible, trusting and individual approach than is traditionally seen in universities.

Purpose: The purpose of this study was to evaluate esthetic posterior stainless steel crowns (EP-SSC) and compare their relative shear strengths.Methods: Sixty EP-SSC were compared. 15 crowns from NuSmile® Primary Crowns, Kinder Krowns, and Dental Innovators 1UP and EC Crowns were studied. The crowns were cemented to a typodont tooth then thermally cycled in water baths to simulate oral conditions. Shear strengths were evaluated by subjecting these crowns to simulated forces of occlusion.Results: The force required to cause shearing of the esthetic facings was statistically significant. With the 1UP crown being significantly weaker than the other crowns tested. Conclusion: The 1 UP crowns failed at lower levels of force than the other types of EP-SSC. The shear strengths for the three other crown types were not statistically different from each other. The esthetic facings do not likely fail from the single point load of a child's bite.

Made available in DSpace on 2016-07-27T14:21:18Z (GMT). No. of bitstreams: 1 FABIANA RAMOS DIAS.pdf: 634003 bytes, checksum: 8af926627f49083ca09820b000c06998 (MD5) Previous issue date: 2007-03-09 / This paper presents the results of a research carried out on an organization of the entertainment and leisure business in the city of Goiânia GO. The present case study has descriptive and exploratory characteristics. The research had the general objective of verifying how do employees of an entertainment organization perceive organization, and how do they experience their interaction with it. As for specific objectives, perception was verified on: the organization of work; working conditions; relationships at work; experiences of joy and suffering of employees and also verifying which strategies of facing it were employed by them to deal with their suffering. Once the organization belonged to the referred business segment, it was assumed that the organization and conditions of labor led the employees into pleasant experiences, for their duty was exactly to promote pleasant experiences to the clients. This research was based on Dejours psychodynamic approach to labor, and on Enriquez s psychosociology. Semi-structured interviews were applied to seventeen employees intentionally chosen from those who dealt with clients. Documents related to policies, ethics, and the missions of the organization were analyzed by graphic analysis of speech. Results indicated rigid conduct policies to workers. Factors which lead to pleasant experiences were observed, such as liberty and recognisement of work, pleasure on the relationship between partners and employees an environment of work, and good wages. As for factors related to suffering, there were complaints of overloading and conditions of work, specially night shift, internal pressures on selling goals, lack of transportation and health insurance, poor security on the way home and lousy labor conditions due to high noise, no ventilation, warm temperature, cigar smoke and weak lighting; factors altogether leading to weary and sickness. In face of such problems, strategies of coping were used, such as negation of reality at work, rationale, and cadency acceleration. Documental analysis pointed to an structural contradiction between an official speech which claims as main factors towards success the adoption of moral and social values and the practice of human resources ideologically compromised to the logic of capitalism and profit generation; thus approaching employees in an instrumental manner, exerting pressure by overloading, exploitation, and alienation. / A dissertação apresenta resultados de uma pesquisa realizada em uma organização que atua no ramo de entretenimento e lazer, localizada em Goiânia-Go. O estudo de caso apresentado teve caráter descritivo e exploratório. A pesquisa teve como objetivo geral verificar como os trabalhadores de uma organização de entretenimento percebiam a organização e vivenciaram sua interação com ela, tendo como objetivos específicos verificar a percepção em relação à organização do trabalho; às condições de trabalho; às relações de trabalho; às vivências de prazer e sofrimento dos trabalhadores e verificar quais as estratégias de enfrentamento foram utilizadas pelos trabalhadores para lidar com o sofrimento. Considerando que a referida organização pertencia ao segmento de entretenimento e lazer, partiu-se do pressuposto que a organização do trabalho e as condições de trabalho propiciariam vivências de prazer nos trabalhadores, uma vez que sua função era exatamente proporcionar diversão aos clientes. A pesquisa fundamentou-se na abordagem psicodinâmica do trabalho de Dejours e psicossociológica de Enriquez. Foram realizadas entrevistas semi-estruturadas com dezessete trabalhadores escolhidos intencionalmente, dentre os responsáveis pelo atendimento direto aos clientes. Foram analisados documentos com informações relativas a normas e código de ética, valores e missão da organização. Os dados foram analisados pela técnica de análise gráfica do discurso. Os resultados indicaram uma organização de trabalho com normas rígidas de conduta para os trabalhadores. Observou-se a presença de fatores que geram vivências de prazer, como liberdade e reconhecimento no trabalho, prazer nas relações sócioprofissionais, ambiente de trabalho e chefia, boa remuneração salarial; em relação aos fatores ligados ao sofrimento, houve queixas ligadas à sobrecarga de trabalho e às condições de trabalho, sendo enfatizados: horário noturno cansativo, pressão interna para cumprimento das metas de vendas, ausência de transporte e de plano de saúde, insegurança ao retornar para casa e condições de trabalho precárias com ruídos altos, ambiente sem ventilação, temperatura quente, esfumaçado de cigarro e iluminação fraca, gerando desgaste e adoecimento dos trabalhadores. Diante de tal sofrimento, foram utilizadas estratégias de enfrentamento, como a negação da realidade do trabalho, racionalização e aceleração das cadências. A análise documental indicou uma contradição estrutural entre um discurso oficial no código de ética que adota como fatores importantes para o sucesso a adoção de valores morais e sociais como centrais e práticas de políticas de pessoal ideologicamente comprometidas com a lógica do capital e geração de lucro, que abordam os trabalhadores de forma instrumental, pressionando-os com sobrecarga, exploração e alienação dos funcionários.

Living in two worlds is an insider perspective of how indigenous Pacific Immigrant communities, in this specific case Fijian's living in New Zealand face the challenges of living two cultures in a developed country like New Zealand. The quest to hold on to one's indigenous culture while adapting to another, in order to survive the realities of everyday circumstances can be a complicated struggle. The main objective of this research was to collate and analyze information from Fijian families who migrated to New Zealand from 1970's to the mid 1980's with reference to the challenges they faced. In order to understand such constant struggles there are underlying questions and factors that should be considered. For example - why do people continue to be conservative about their cultural identities or how do they react to unfamiliar challenges in a multicultural society. Another could be - what influences have been seen in order for their children to recognize their indigenous identity. Comparable factors that will bring to other aspects of living in two worlds which would be considered were socio-economic issues, higher education, technological advancement, immigration policies, development constraints and quality of living standards. Fijians and other indigenous Pacific people have through the years gained the ultimate will to defend their cultural and traditional identity whilst living in a world of western values and culture. Coupled with this have been the complexities of holding on to the values of both worlds. As this project probed into these newly rediscovered stories about journeys to their new homeland filled with opportunities, capitalism or westernization had never withered their passion and dreams as Pacific people to better themselves. They also enjoyed the luxury of both worlds as conservators of Pacific cultures and exploiters of technological advancement filled with huge dreams, opportunities and better standards of living. Fijians have the smallest population of Pacific people in New Zealand when compared to Samoa, Tonga, and Cook Islanders. There were relatively small number of Fijians who arrived after the end of World War 2 and they were basically employed in farms, forestry work stations and industrial areas. Others were in New Zealand on government scholarships, training or internship and work experience programs. Most of these people returned home while a very small proportion stayed behind. In the early 1970's and 1980's there was also an influx of seasonal workers in the Central North Island areas including Hawkes Bay, Tokoroa and the Waikato region. Most people were recruited from the Pacific Islands including Fiji because of their hard working attitude and cheap labour margins. When their term was completed some decided to stay and work, eventually residing legally and permanently with their families. Another group of men came via Wellington by boat, destined to become maintenance and repair workers. (bound for maintenance and repair work and ) but were left stranded when the shipping company ownership changed. The dock and maritime workers union fought for the case stating the government on humanitarian grounds should provide them with employment and residency status. After an extensive legal struggle, which lasted almost seven years these early Fijian workers and their families were granted work and residency permits. The (remaining) other families came as visitors or through marriage links and were granted work and residency permits. The 1996 statistics (Statistics New Zealand, Census 1996) stated that Fijians were the most highly skilled and educated Pacific Island population in New Zealand. These statistics had been directly influenced by the latest influx of well educated and highly qualified Fijians who arrived in the late 1990's. The research will also highlight whether those who arrived before this latest influx faced the same challenges. These challenges will be compared to those faced by the generation of Fijians and Pacific people who were born and bred in New Zealand.

Tungsten (W) based materials can be used in fusion reactors due to several advantages. Different fabrication routes can be applied to develop tungsten materials with intended microstructure and properties for specific application including nanostructured grades. Therein, innovative chemical routes are unique in their approach owing numerous benefits. This thesis summarizes the development of W-based composites dispersed-strengthened by rare earth (RE) oxides and their evaluation for potential application as plasma facing armour material to be used in fusion reactor. Final material development was carried out in two steps; a) fabrication of nanostructured metallic tungsten powder dispersed with RE-oxides and b) powder sintering into bulk oxide-dispersed strengthened (ODS) composite by spark plasma process. With the help of advanced characterization tools applied at intermediate and final stages of the material development, powder fabrication and sintering conditions were optimized. The aim was to achieve a final material with a homogenous fine microstructure and improved properties, which can withstand under extreme conditions of high temperature plasma. Two groups of starting materials, synthesized via novel chemical methods, having different compositions were investigated. In the first group, APT-based powders doped with La or Y elements in similar ways, had identical particles’ morphology (up to 70 μm). The powders were processed into nanostructured composite powders under different reducing conditions and were characterized to investigate the effects on powder morphology and composition. The properties of sintered tungsten materials were improved with dispersion of La2O3 and Y2O3 in the respective order. The oxide dispersion was less homogeneous due to the fact that La or Y was not doped into APT particles. The second group, Ydoped tungstic acid-based powders synthesized through entirely different chemistry, contained nanocrystalline particles and highly uniform morphology. Hydrogen reduction of doped-tungstic acid compounds is complex, affecting the morphology and composition of the final powder. Hence, processing conditions are presented here which enable the separation of Y2O3 phase from Y-doped tungstic acid. Nevertheless, the oxide dispersion reduces the sinterability of tungsten powders, the fabricated nanostructured W-Y2O3 powders were sinterable into ultrafine ODS composites at temperatures as low as 1100 °C with highly homogeneous nano-oxide dispersion at W grain boundaries as well as inside the grain. The SPS parameters were investigated to achieve higher density with optimum finer microstructure and higher hardness. The elastic and fracture properties of the developed ODS-W have been investigated by micro-mechanical testing to estimate the materials’ mechanical response with respect to varying density and grain size. In contrast from some literature results, coarse grained ODS-W material demonstrated better properties. The developed ODS material with 1.2 Y2O3 dispersion were finally subjected to high heat flux tests in the electron beam facility “JUDITH-1”. The samples were loaded under ELM-like thermal-shocks at varying base temperatures up to an absorbed power density of 1.13 GW/m2, for armour material evaluation. Post mortem characterizations and comparison with other reference W grades, suggest lowering the oxide contents below 0.3 wt. % Y2O3. As an overview of the study conducted, it can be concluded that innovative chemical routes can be potential replacement to produce tungsten based materials of various composition and microstructure, for fusion reactor applications. The methods being cheap and reproducible, are also easy to handle for large production at industrial scale. / <p>QC 20120827</p>

No description available.

An experimental study was undertaken to investigate the effect of roughness on the characteristics of separated and reattached turbulent shear flow downstream of a backward facing step. Particle image velocimetry technique was used to conducted refined velocity measurements over a reference smooth acrylic wall and rough walls produced from sandpaper 36 and 24 grits positioned downstream of a backward facing step, one after another. Each experiment was conducted at Reynolds number based on the step height and centerline mean velocity of 7050. The results showed that sandpaper 36 and 24 grits increased the reattachment length by 5% and 7%, respectively, compared with the value obtained over the smooth wall. The distributions of the mean velocities, Reynolds stresses, triple velocity correlations and turbulence production are used to examine roughness effects on the flow field downstream of the backward facing step. Two-point auto-correlation function and proper orthogonal decomposition (POD) are also used to investigate the impact of wall roughness on the large scale structures.

A robotically-controlled actuation system has been developed and built to perform active open-loop flow control experiments on transitional and turbulent backward-facing step flows in water. Control of the reattaching shear layer used hydraulic suction-and-blowing actuation emanating from 128 individual ports along the separation edge of the step. Each ports perturbation was periodic in time, but individually controlled to produce either spanwise-invariant (2D) or spanwise-varying (3D) spatial actuation profiles. An image processing system and special aqueous tuft were developed to measure the length of the recirculation bubble. Multiple images of a tuft array were time-averaged to do so. In general, 3D forcing was no more effective in reducing bubble length than 2D forcing. However, greater local spanwise reductions in reattachment length were observed for some cases of spanwise-varying forcing. Backlit dye was used to track the evolution of vorticity in the flow in video and still images.