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1
Cole, David J. "Evaluation of fit for 3D printed retainers as compared to thermoform retainers." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5332.
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ABSTRACT
EVALUATION OF FIT FOR 3D PRINTED RETAINERS AS COMPARED TO THERMOFORM RETAINERS
By David Cole, D.M.D.
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University
Thesis Directors: Eser Tüfekçi, D.D.S., M.S., Ph.D., M.S.H.A.
Professor, Department of Orthodontics
Sompop Bencharit, D.D.S., M.S., Ph.D.
Associate Professor and Director of Digital Dentistry, Department of General Practice
Introduction: Despite recent advances in three-dimensional (3D) printing, little information is available on 3D printed retainers
Methods: Three reference models were used to fabricate traditional vacuum formed, commercially-available vacuum formed, and 3D printed retainers. For each model, three retainers were made using the three methods (a total of 27 retainers). To determine the trueness, the distances between the intaglio surface of the retainers and the occlusal surface of the reference models were measured using an engineering software. A small difference was indicative of a good fit.
Results: Average differences of the traditional vacuum formed retainers ranged from 0.10 to 0.20mm. The commercially-available and 3D printed retainers had a range of 0.10 to 0.30mm and 0.10 to 0.40mm, respectively.
Conclusions: The traditional vacuum formed retainers showed the least amount of deviation from the original reference models while the 3D printed retainers showed the greatest deviation.
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Al-Groosh, D. H. A. "Opportunistic pathogens associated with orthodontic retainers." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1419096/.
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Orthodontic retainers may be considered as removable implants and confer the same problems as other implants with regard to colonisation by microorganisms. Thus, biofilms forming on their surface may compromise the oral health of patients and jeopardise the efficiency of the therapy. The first part of the project involved a clinical study, a cross-sectional observational cohort, to assess the effect of orthodontic treatment on the oral microbiota and the carriage state of opportunistic pathogens during the course of treatment. High proportions of health-associated species were detected in the retainer group. However, Staphylococcus and Candida species were frequently (69% and 36% respectively) isolated from the retainers and the oral cavity of retainer wearers, where Staphylococcus spp. comprised up to 5% of the microbiota. The increase in Staphylococcus spp. including Methicillin Resistant Staphylococcus aureus (MRSA) on retainers was associated with an increase in numbers of these species on the oral mucosa of the cheek and tongue. Orthodontic retainers could, therefore, be a reservoir for pathogens and act as a source of cross-infection. A series of in vitro investigations were subsequently carried out to evaluate the effect of the surface characteristics of retainer materials, including surface roughness, hydrophobicity and surface free energy, which may affect colonisation by opportunistic pathogens. After polishing the surface of the acrylic substrata the results revealed that Atomic Force Microscope was the most appropriate device to measure the surface roughness of the acrylic and thermoplastic materials in a consistent manner. Additionally, the acid-base interactions, especially the electron donor interaction, influenced the bacterial attachment onto the thermoplastic samples. Finally, assessment of novel antimicrobial-containing acrylic resins was carried out. Firstly, incorporation of chlorhexidine showed a prolonged antimicrobial effect against MRSA but was detrimental to the mechanical properties. Thymol was successfully incorporated in heat cured acrylic materials. It reduced the surface free energy of the modified resin with no effect on the mechanical properties and was strongly antimicrobial against C. albicans. However, it showed a lesser antimicrobial effect against MRSA. This PhD has shown the potential of orthodontic retainers as reservoirs for opportunistic pathogens and that surface characteristics are significant in the retention and potential removal of these pathogens. The use of antimicrobial acrylic materials may be of potential therapeutic benefit following further development.
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Walker, S. K. "John of Gaunt and his retainers, 1361-1399." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236168.
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Schütz-Fransson, Ulrike. "Fixed mandibular retainers : a controlled 12-year follow-up." Licentiate thesis, Malmö universitet, Odontologiska fakulteten (OD), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-7756.
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Fixed retainer after orthodontic treatment is an increasing retention appliance. For the mandibular incisors there are two different fixed retainers that are commonly used, either a canine-to-canine retainer bonded only to the canines or a twistflex retainer bonded to each of the mandibular incisors and canines. Increased mandibular incisor irregularity seems to be a continuous process throughout life even in untreated patients. The natural physiological changes during aging causes changes like those that occur after orthodontic treatment and the removal of retainers. There are few long-term studies that have compared patients who have had a mandibular fixed retainer with patients without retention appliance after treatment, and then compared the treated patients with untreated subjects.The overall aim of this thesis was to compare and evaluate two different mandibular fixed retainers and also to compare orthodontically treated cases with untreated long-term. This thesis is based on two studies and a PAR Index evaluation was presented in the frame story:Paper I is a retrospective longitudinal study done on dental casts and lateral head radiographs from patients who had received either a canine-to-canine retainer or a twistflex retainer after treatment. Different variables were measured, were Little’s Irregularity Index was the main outcome measure. The measurements were done at four different occasions, were the last registration was 12 years after treatment, i.e. 9 years after removal of retainer. Paper II is also a retrospective longitudinal study with three different groups, one group received a fixed mandibular retainer, one group did not receive any retention appliance after treatment and the third group was untreated subjects. Measurements were done on dental casts and lateral head radiographs at four different occasions to analyze dental and skeletal changes 12 years after treatment. Also here Little’s Irregularity Index was the main outcome measure. PAR Index evaluation is done to evaluate the stability of orthodontic treatment outcome after treatment and long-term for two different retainer groups and one non-retention group. The following conclusions were drawn: Paper I•Both the canine-to-canine retainer and the twistflex retainer can be recommended since both are equally effective during retention period.•None of the retention types prevent long-term changes of mandibular incisor irregularity or available space for the mandibular incisors after removal of the retainers.•No differences in bonding failures between the two retainers were found. Paper II•There were no differences found 12 years after treatment in Little’s Irregularity Index for the mandibular incisors between the group that had a retainer and the group that had no retainer after treatment•In the untreated group, Little’s Irregularity Index was increased over time but not to the same extent as in the treated groups. •The crowding before treatment did not explain the crowding at the last registration.•The use of mandibular retainers for two to three years does not appear to prevent long-term relapse. •If the patient wants to constrain the changes that come with natural development, then lifelong retention is needed.•The overjet and overbite were stable long-term.PAR Index evaluation•Twelve years after treatment the mean reduction in PAR score was over 70 per cent only for the groups who had a mandibular retainer after treatment. However, the non-retention group had a PAR score of 66 per cent.•There were more cases in the retention groups that were ”greatly improved and/or improved” 12 years after treatment compared to the non-retention group. After treatment between 16 and 23.3 per cent of all the cases were ”worse or not improved”. Twelve years after treatment between 36 and 43.6 per cent of the total cases were ”worse or not improved”.
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Müller, Matthias. "Predicting the ultimate axial load capacity of joints formed using V-band retainers." Thesis, University of Huddersfield, 2011. http://eprints.hud.ac.uk/id/eprint/12144/.
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V-band retainers are widely used in the automotive, aircraft and aerospace industries to connect a pair of circular flanges to provide a joint with good axial strength and torsional rigidity. V-band retainers are manufactured using a cold roll forming process. Despite their wide application, once assembled to a pair of flanges little is known about the interaction between flange and band. Moreover the failure mode of V-band retainers when applying an axial load is not fully understood. In this thesis the ultimate axial load capacity of V-band retainers is predicted using finite element and theoretical models and validated using experimental testing. It was shown that the ultimate axial load capacity was strongly dependent on the joint diameter, increasing between 114mm and 235mm, and decreasing beyond that. Moreover, the peak in ultimate axial load capacity was dependent on parameters such as the axial clamping load and coefficient of friction, and its position lay between 235mm and 450mm, as predicted by the finite element models. Other geometrical parameters such as flange and band thickness showed large impacts on the ultimate axial load capacity as well. A theoretical model was developed that allowed the ultimate axial load capacity to be calculated from a single formula for larger bands and using a simple algorithm for smaller bands. This model supported the findings that, depending on the band diameter, the ultimate axial load capacity had a peak, but predicted its position at approximately 181mm. This position at 181mm was validated by the experimental data. However, when compared to the tests, the finite element and theoretical models both over-predicted the ultimate axial load capacity. Both the finite element models and practical tests showed that for small V-bands axial failure is due to a combination of section deformation and ring expansion, whereas large V-bands fail due to ring expansion only. These two distinct types of behaviour were incorporated into the theoretical model. The hardness development throughout the cold roll forming process was predicted using finite element models. This was validated by hardness measurements, for which a new technique was generated, that directly linked plastic strain and hardness values.
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Hobson, Ross S. "Factors affecting the resin to enamel bond in orthodontics." Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310170.
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Higa, Rodrigo Hitoshi. "Influence of different orthodontic upper retainers in speech: analysis by laypersons and acoustic analysis." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/25/25144/tde-02102018-221945/.
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Introduction: The aim of this study was to evaluate the influence of different upper retainers in speech, through Perceptual Auditory Analysis by the laypersons and acoustic analysis. Methods: Eighteen volunteers were selected to use four types of upper retainers: conventional Wrap-Around (CWA), modified horseshoe Wrap-Around (HWA), modified anterior hole Wrap-Around (AHWA) and vacuum-formed (VF). They were used for 21 days each, with intervals of 7 days without use among them. Speech evaluation was performed in vocal excerpts recordings made before installation of the retainers (T0), immediately after the installation of each retainer (T1), and 21 days after the installation (T2). The Perceptual Auditory Analysis of laypersons was performed by means of the visual analogue scale of 100 mm, while the acoustic analysis consisted of the mean diadochokinesia (DDK) rate evaluation, as well as the formant frequencies F1 and F2 of the fricative consonants. One-way ANOVA and two-way ANOVA were used. Results: In the Perceptual Auditory Analysis of laypersons, there was a worsening in the values of T0 to T1 in all the retainers, but only for CWA and VF the values were statistically lower. In T2 the values increased, but for the VF the value still remained statistically lower than T0 while for the AHWA the difference of T0 for T2 was practically null. There were no changes in DDK values. For the formant frequencies, in general way there was a difference from T0 to T1 and a little difference from T0 to T2, whereas in the comparison among the devices the CWA presented greater changes in the F1 formants of some consonants, whereas AHWA presented lower values, with the others devices showing intermediate values. Conclusions: In both types of analysis (subjective and objective), there was a change in speech after the installation of each retainer, with an improvement after 21 days of use. The laypersons considered larger speech disorders involving VF, and smaller ones involving AHWA. For the acoustic analysis, the changes were greater for CWA, whereas for AHWA there were lower changes.<br>Introdução: O objetivo deste estudo foi avaliar a influência de diferentes contenções superiores na fala, através de análise perceptiva auditiva por leigos e análise acústica. Métodos: Dezoito voluntários foram selecionados para utilizar quatro tipos de contenções superiores, sendo elas: placa Wrap-Around convencional (WAC), Wrap- Around modificada em formato de ferradura (WAF) Wrap-Around modificada com orifício anterior (WAO) e contenção termoplástica transparente (CTT). Elas foram usadas por 21 dias cada, com intervalos de 7 dias sem utilização entre elas. A avaliação da fala foi realizada em gravações de trechos vocais realizadas antes da instalação das contenções (T0), imediatamente após a instalação de cada contenção (T1), assim como após 21 dias de uso destas (T2). A análise perceptiva auditiva dos leigos foi realizada através da escala visual analógica de 100 mm, enquanto a análise acústica consistiu na avaliação da média da taxa de diadococinesia (DDC), bem como a frequência dos formantes F1 e F2 das consoantes fricativas. Os testes ANOVA a um critério e ANOVA a dois critérios foram utilizados. Resultados: Na análise perceptiva auditiva dos leigos houve uma piora nos valores de T0 para T1 em todas as contenções, mas somente para WAC e CTT os valores foram estatisticamente menores. Em T2 os valores voltaram a aumentar, mas para CTT ainda houve um valor estatisticamente menor do que T0 enquanto para WAO a diferença de T0 para T2 foi praticamente nula. Não houve alterações nos valores da DDC. Para os formantes, de uma maneira geral houve uma diferença de T0 para T1 e pouca diferença de T0 para T2, enquanto na comparação entre os aparelhos a WAC apresentou alterações maiores nos formantes F1 de algumas consoantes, enquanto WAO apresentou valores menores, e os demais dispositivos valores intermediários. Conclusões: Nos dois tipos de análise (subjetiva e objetiva) houve alteração na fala após a instalação de cada contenção, havendo uma melhora após 21 dias de uso. Os leigos consideraram maiores as alterações da fala envolvendo a CTT, e menores envolvendo WAO. Para a análise acústica os valores foram piores para WAC, enquanto para WAO as alterações foram menores.
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Atta, M. O. A. "A comparative study of the bond strength of chemical and mechanical retention systems for direct bonded bridge retainers." Thesis, King's College London (University of London), 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320471.
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Junior, Luiz Eduardo Alessio. "Alterações dimensionais dos arcos dentários decorrentes do tratamento com o aparelho Pendulum associado ao fixo: avaliação longitudinal." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/25/25144/tde-08012013-161621/.
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Objetivo: avaliar, por meio de modelos digitalizados, o comportamento transversal do arco dentário superior de pacientes submetidos ao tratamento da má oclusão de Classe II, corrigida com o aparelho Pendulum, seguido de aparelhagem ortodôntica fixa nos períodos inicial, pós-distalização, pós-tratamento e longo tempo póstratamento. Material e Métodos: Oitenta modelos de 20 pacientes (14 do gênero feminino e 6 do masculino), foram digitalizados no aparelho REXCAN DS2. A média da idade, ao início do tratamento (T1), foi de 14,02 ± 1,62 anos, pós-distalização (T2), foi de 14,54 ± 1,61, ao final do tratamento (T3), 18,38 ± 1,84 anos, e no póstratamento (T4), 22,94 ± 1,34 anos. As distâncias intercaninos, interpré-molares e intermolares foram realizadas no programa Geomagic Studio 5®. A análise de variância dependente para medidas repetidas (ANOVA) foi utilizada para avaliar as alterações entre os períodos. Resultados: não ocorreram alterações transversais na distância intercaninos nas fases estudadas. Os pré-molares demostram um aumento na fase de aparelhagem fixa (T2-T3), para os segundos pré-molares a diferença foi observada entre o período inicial (T1) e os período pós-tratamento (T3). A distância dos primeiros molares alterou durante a fase de distalização (T1-T2), retornando aos valores iniciais durante a fase pós-tratamento (T3). Para os segundos molares, as alterações ocorreram durante o período de distalização (T2) e pós-tratamento (T3). Não ocorreram alterações na fase de longo tempo pós-tratamento. Conclusão: Os resultados permitem concluir que, durante o tratamento com o aparelho Pendulum seguido pelo fixo, ocorrem alterações transversais no arco superior, no entanto, estas alterações permanecem estáveis cinco anos pós-tratamento.<br>Objective: The aim of this longitudinal study was to asses transversal changes in maxillary dental arch in twenty patients between 14 and 18 years old, treated first by Pendulum and followed by fixed appliances. Material and Methods: Dental measurements in eighty digital 3D models were obtained in pretreatment, postdistalization, post-treatment and long-term post-treatment phases. The statistical analysis was performed by ANOVA test. Results: Premolars and molars distances increased during the fixed appliance treatment (post-distalization and post-treatment phase) and in the long post-treatment phase there were no significant changes. No significant difference was observed in canines transversal distance. Conclusion: It was concluded that Pendulum followed by the fixed appliances, changes dental arch width during the full treatment and it was stable in the long-term post-treatment.
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Belachew, Johanna. "Retained Placenta and Postpartum Haemorrhage." Doctoral thesis, Uppsala universitet, Institutionen för kvinnors och barns hälsa, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-246185.
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The aim was to explore the possibility to diagnose retained placental tissue and other placental complications with 3D ultrasound and to investigate the impact of previous caesarean section on placentation in forthcoming pregnancies. 3D ultrasound was used to measure the volumes of the uterine body and cavity in 50 women with uncomplicated deliveries throughout the postpartum period. These volumes were then used as reference, to diagnose retained placental tissue in 25 women with secondary postpartum haemorrhage. All but three of the 25 women had retained placental tissue confirmed at histopathology. The volume of the uterine cavity in women with retained placental tissue was larger than the reference in most cases, but even cavities with no retained placental tissue were enlarged (Studies I and II). Women with their first and second birth, recorded in the Swedish medical birth register, were studied in order to find an association between previous caesarean section and retained placenta. The risk of retained placenta with heavy bleeding (>1,000 mL) and normal bleeding (≤1,000 mL) was estimated for 19,459 women with first caesarean section delivery, using 239,150 women with first vaginal delivery as controls. There was an increased risk of retained placenta with heavy bleeding in women with previous caesarean section (adjusted OR 1.61; 95% CI 1.44-1.79). There was no increased risk of retained placenta with normal bleeding (Study III). Placental location, myometrial thickness and Vascularisation Index were recorded on 400 women previously delivered by caesarean section. The outcome was retained placenta and postpartum haemorrhage (≥1,000 mL). There was a trend towards increased risk of postpartum haemorrhage for women with anterior placentae. Women with placenta praevia had an increased risk of retained placenta and postpartum haemorrhage. Vascularisation Index and myometrial thickness did not associate (Study IV). In conclusion: 3D ultrasound can be used to measure the volume of the uterine body and cavity postpartum, but does not increase the diagnostic accuracy of retained placental tissue. Previous caesarean section increases the risk of retained placenta in subsequent pregnancy, and placenta praevia in women with previous caesarean section increases the risk for retained placenta and postpartum haemorrhage.
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Piskac, Ellen M. Hawkins Peggy L. "Characteristics of retained nursing faculty." Click here for access, 2008. http://www.csm.edu/Academics/Library/Institutional_Repository.
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Thesis (Ph. D.)--College of Saint Mary -- Omaha, 2008.<br>Presented to the faculty of College of Saint Mary in partial fulfillment of requirements for the degree of Doctor of Education. Under the supervision of Peggy Hawkins. Includes bibliographical references.
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Nowak, Magdalena. "Development of niobium boron grain retainer for aluminium silicon alloys." Thesis, Brunel University, 2011. http://bura.brunel.ac.uk/handle/2438/8321.
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Aluminium castings with a large grain structure have poor mechanical properties which are primarily due to casting defects as opposed to fine grain structure. The grain refinement practice using chemical addition is well established for wrought alloys, however in the case of casting alloys, the practice of adding grain refiners and the impact on castability is not well established. The addition of well known Al-5Ti-B grain refiner to casting alloys with silicon (Si) content above 3 wt.% is not effective. This is believed to be due to the chemical reaction between Ti and Si. The current research aim is to find an alternative, but effective, chemical phase which can refine Al-Si alloy grains. Based on a crystallographic database search and intermetallic phases found in Aluminium–Niobium-Boron, there exists several iso-structural phases similar to those of Al3Ti and TiB2. We have selected a phase which exhibits chemical phase stability with Si (below 900 oC) and developed a potential novel grain refiner Nb-B for Al-Si cast alloys. Various Al-Si binary alloys and a commercial sourced LM6 (Al-10Si-Mg) cast alloys were cast after novel grain refiner addition to the melt. It is the first time that such fine grain structures were achieved for Al-Si alloys when Si >4wt.%. It is believed that Nb-B grain refiner enhances the heterogeneous nuclei in the melt. The effectiveness of this grain refiner under various cooling rate conditions is investigated to simulate various practical casting conditions. Due to increased heterogeneous nuclei density, a fine grain structure is also obtained at low cooling rates and the grain size is less sensitive to the cooling rate. The processing of high Si containing alloys for complex shaped castings with reduced defects, fine grain structure and improved mechanical properties are now possible.
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Stephenson, Robert John. "A comparison of retained biomass anaerobic digester designs." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26740.
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The principles behind anaerobic digestion are fairly well understood, but the limits of application of each digester design are not known. Because there are significant differences in the properties of the many wastewaters requiring treatment optimal anaerobic digester performance requires the matching of feed characteristics to a digester design and mode of operation. No consensus has yet emerged on digester design, operating conditions or feed/digester match-ups.
In this study, three bench scale retained biomass anaerobic digester designs were examined for their response to a sequence of varied hydraulic retention times (HRTs) and influent wastewater concentrations. The digester designs studied were the upflow anaerobic filter, the upflow anaerobic expanded bed and the upflow anaerobic sludge bed. The wastewater was screened and diluted dairy cow manure obtained from the UBC dairy barn. The parameters monitored included the total and soluble chemical oxygen demand (TCOD and SCOD), volatile and suspended solids (VS and SS), total volatile fatty acids (VFAs), total Kjeldahl and ammonia nitrogen (TKN and NH₃-N), pH, biogas production, and the methane (CH₄) and carbon dioxide (C0₂) content of the biogas.
Wastewater treatment efficiencies, measured in terms of TCOD, SCOD, VS, and TVFA removals, and methane productivity and methane yield for each of the digester designs were examined for the range of the operating conditions.
The anaerobic filter digester effected a mean TCOD removal efficiency of 47% ± 14% at a mean 4.0 day HRT, 51% ± 9% at a mean 2.3 day HRT and 35% ± 11% at a mean 1.3 day HRT. The expanded bed digester effected a mean TCOD removal of 45% ± 15% at a mean 4.3 day HRT, 38% ± 12% at a mean 2.5 day HRT and 28% ± 9% at a mean 1.3 day HRT. The sludge bed digester effected a mean TCOD removal of 53% ± 9% at a mean 3.8 day HRT, 45% ± 12% at a mean 2.2 day HRT and 32% ± 10% at a mean 1.2 day HRT. For all three digesters, the difference in the treatment efficiency over the range of HRTs tested, from 5 to 1.25 days was not in proportion to the change in HRT. Methane productivity, measured against either the removal or addition of substrate in terms of TCOD, SCOD, VS and TVFA, demonstrated considerable variability. Methane production increased with both substrate addition and substrate removal. Methane yield increased with increasing HRT. The sludge bed digester generally exhibited the greatest but most variable methane yields. It produced 0.095 L CH₄/g VS added at a mean 3.8 day HRT and 0.037 L CH₄/g VS added at a mean 1.2 day HRT. The anaerobic filter delivered the greatest methane yield at the intermediate HRT, 0.044 L CH₄/g VS added at a mean 2.3 day HRT. The expanded bed demonstrated low methane yields over the range of feed strengths and HRTs tested.
Biogas composition averaged 62.1% methane and 17.1% carbon dioxide for the anaerobic filter, 43.6% methane and 5.3% carbon dioxide for the expanded bed. and 61.1% methane and 18.9% carbon dioxide for the sludge bed.<br>Applied Science, Faculty of<br>Graduate
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Salgado, Francisco Manuel Goncalves Alves. "Analysis procedures for caisson-retained island type structures." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30845.
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This thesis is concerned with the analysis of large offshore gravity structures used for oil exploration and recovery in the Beaufort Sea. Because of the high ice loads and the water depths involved, these structures comprise a large steel box infilled with a sand core for stability. One such structure was subjected to severe ice loading in April 1986 causing portions of the sand core to liquefy and bring the structure to a near failure condition. This structure was heavily monitored and thus serves as a case study against which the proposed analysis procedure can be checked.
The behaviour of these soil-structure systems is highly complex depending upon the characteristics of the soil, the structural elements and the soil-structure interface. In this thesis a three-dimensional Finite Element computer program with soil, interface and structural elements is developed.
Emphasis is placed on the three-dimensional stress-strain constitutive law both in terms of its ability to model observed laboratory response as well as the determination of the constitutive law parameters from in situ testing.
The results obtained in terms of displacement, acceleration and zones of liquefaction by the analysis were then compared with the field measurements obtained during the April 1986 ice load event. The good agreement obtained between predicted and observed response is a validation of the proposed procedure.<br>Applied Science, Faculty of<br>Civil Engineering, Department of<br>Graduate
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Abudaia, Fouad Belgassem. "Microstructure and fatigue strength of high performance gear steels." Thesis, University of Newcastle Upon Tyne, 2003. http://hdl.handle.net/10443/176.
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Observations on some steels used in high performance gears are presented in this thesis. The object was to understand how microstructure and residual stress influenced mechanical properties, particularly fatigue strength. The investigations were carried out using fatigue testing, metallographic techniques, shot peening, hardness testing and Xray diffraction to determine residual stress and the amount of retained austenite. The work is divided into two main parts. In the first part, the opportunity was taken of investigating a batch of case-carburised gears manufactured from 17CrNiMo6 steel that contained an abnormally high level of retained austenite. . The benefits or otherwise of retained austenite is a matter of some controversy in the literature and this was an opportunity of testing the effect of high retained austenite in gears. In the second part, the properties of a recently formulated through hardening steel was investigated. The steel is inexpensive and capable of being fully hardened by air-cooling. It is believed that use of the material could reduce the cost of gear manufacture by eliminating the carburisation process, oil quenching and the subsequent need to correct distortions that arise from quenching. Gears were manufactured using l7CrNiMo6 steel. After carburization, one batch was found to have an abnormally high level of retained austenite (40 to 60%). Normally, gears with this level of retained austenite would be rejected. Nevertheless, gears from this batch were found to have surface and bending fatigue strengths that were not very different from those with much lower retained austenite contents. Despite the fact that the material is relatively soft, it was found that a very thin surface layer had hardened during back-to-back gear testing, probably by strain-induced transformation of the retained austenite. It was deduced that this thin layer of hardened material is sufficient to maintain a good level of surface contact fatigue strength. The second part of the work includes a basic study of the through-hardening steel. The study includes heat treatment and hardness, estimation of fracture toughness and the development of residual stress during heat treatment. Specialised standing contact fatigue (SCF) tests were also done using this material. The SCF test consists of cyclic loading of a hard ball in contact with the surface of the specimen, which is meant to simulate asperity contact in surface contact fatigue. Radial cracks or ring cracks or both are nucleated just outside the indentation circle in these tests, depending on the load and the development of plasticity. The stresses near the indentation were modelled using Finite Element analysis and were found to be consistent with the experimental results. Finally, the effect of residual compressive stress induced by shot peeing was studied using the SCF test. It was found that shot peening suppressed the formation of radial cracks.
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Vale, Ellen. "Interval timing and dopamine : effects of attention deficit hyperactivity disorder and caffeine on the reproduction of short intervals." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273680.
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Saha, Podder Arijit. "Tempering of a mixture of bainite and retained austenite." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609405.
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Matyus, Jason Michael. "Increasing Productivity of Retained Employees After a Workforce Reduction." ScholarWorks, 2015. https://scholarworks.waldenu.edu/dissertations/1906.
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There is an increased use of downsizing across telecommunications in the northeast United States, and organizational leaders are challenged to motivate the productivity of the retained employees. Guided by systems theory, the purpose of this single case study was to explore successful downsizing strategies of a small group of organizational leaders and managers in the operations of telecommunications in the northeast United States. The study participants, chosen for their motivation success in motivation after downsizing, consisted of 2 purposefully selected business leaders who completed individual, face-to-face interviews and a focus group of 5 managers. The coding of data and word clusters from data obtained from the interviews and focus group led to 4 emergent themes of organizational communication, leadership, employee motivation, and work-life balance. The participant responses showed through topic saturation that communication and work-life balance were the most important major themes. The findings from this study suggest that communication during all phases of downsizing can add to the employees' motivation and employees understanding of what leadership expects from them. When organizational leaders communicate a message of a better work-life balance, positive social change may occur, creating a more productive and loyal employee. When employees have a healthy work-life balance, there are significant benefits to their work organizations, families, and home lives.
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Schwieger, Isabel [Verfasser]. "Degradation of intracellular retained V2 vasopressin receptor mutants / Isabel Schwieger." Berlin : Freie Universität Berlin, 2008. http://d-nb.info/1023095645/34.
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Gee, G. D. "An assessment of patients treated with implant retained mandibular overdentures /." Title page, summary and contents only, 1995. http://web4.library.adelaide.edu.au/theses/09DM/09dmg297.pdf.
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Hirschi, Matthew H. "Determining Profitability Strategies for Various Retained Ownership Enterprises in Utah." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/891.
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With the price of corn now over $6 per bushel, and with feedlot total cost per pound of gain now approaching $1.00 per pound of gain there are new incentives to try and add weight to calves outside of feedlots. The question then arises of how to add weight to a calf in the most economical manner. There are many different feeding programs to consider. However, with few exceptions, the cheapest way to add weight outside of a feedlot usually involves the calf grazing for an extended period of time. Winter pasture grazing, wheat pasture grazing and corn stalk grazing followed by summer pasture grazing are examples of these programs.
However, with the exception of California, most of the area west of the Great Plains lacks the resources and climate for most of these winter grazing programs. For those states, cattle producers can background calves through the winter and then allow them to graze pastures in the summer. Backgrounding calves is essentially taking calves at weaning and feeding them to heavier weights without placing them directly in a feedlot on a finishing ration.
The overall objective of this research is to evaluate the level and variability of returns to several background feeding alternatives. The returns will be evaluated in an expected value-variance analysis and ranked using stochastic dominance procedures.
It appears that there are several different background alternatives that producers could utilize to increase returns with an acceptable level of risk and add additional value to their calves.
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Forrest, Diane S. "Prevalence of retained primitive reflexes in patients with anxiety disorders." Thesis, University of Edinburgh, 2002. http://hdl.handle.net/1842/28040.
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Anxiety is not only one of the mental health disorders most commonly referred to clinicians, but is also a research interest, producing subsequent modification in treatment approaches. However, there are suggestions in the literature that the effectiveness of some psychological treatments have not been systematically evaluated (Department of Health, 2001), or that treatment studies have employed methods unrepresentative of everyday clinical practice (World Health Organization.2000). Furthermore, from analysis of outcome studies, psychological therapies have been reported as effective for only half of those treated (Fisher & Durham, 1999). These findings suggest that there are individuals with anxiety who fail to respond to available therapies, and that alternative approaches for this group are not well studied. Anxiety is not only one of the mental health disorders most commonly referred to clinicians, but is also a research interest, producing subsequent modification in treatment approaches. However, there are suggestions in the literature that the effectiveness of some psychological treatments have not been systematically evaluated (Department of Health, 2001), or that treatment studies have employed methods unrepresentative of everyday clinical practice (World Health Organization.2000). Furthermore, from analysis of outcome studies, psychological therapies have been reported as effective for only half of those treated (Fisher & Durham, 1999). These findings suggest that there are individuals with anxiety who fail to respond to available therapies, and that alternative approaches for this group are not well studied. tests employed in the study. From analysis of all individual test scores, two of these, detecting involvement of labyrinthine processes, resulted in the highest scores. The findings from analysis of resulting data are discussed in relation to implications for future study and further use of the measures with differing populations.
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Albright, Kay. "The feasibility of retained ownership strategies for cow-calf producers." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/8624.
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Master of Science<br>Department of Agricultural Economics<br>Michael R. Langemeier<br>Retained ownership can generally be described as when a producer does not sell his or her calf crop immediately after weaning but keeps the calves for an extended period of time. This is a decision that is made by the cow-calf producer every year and may or may not change from year to year. For some, the decision is based on past practices while others will evaluate the market before making a decision. There are various levels of retained ownership that can be modified to fit a producer’s operation and can range from a preconditioning program to finishing the cattle in the feedlot. This study specified various retained ownership scenarios in order to be able to analyze the situations.
Budgets were used to analyze the optimum phase of production at which to sell calves that is most profitable while taking risk into consideration. Specifically, budgets were developed for scenarios of four cow-calf herds, four backgrounding phases, two grazing phases, and six custom feedlot phases. These budgets were used to produce sixteen potential retained ownership scenarios. The scenarios range from selling the calves immediately after weaning to owning the cattle through finishing at the feedlot. Each scenario was then analyzed based on the net returns over a 10-year period. Additionally, the scenarios were analyzed based on net returns over feed costs.
Target MOTAD was used to analyze the risk component of the scenarios. Although most of the net returns were negative for all scenarios, retained ownership showed a trend of improving net returns. However, along with the improved returns came a greater variability in returns which is unattractive to a risk adverse producer. Target MOTAD results on a net return basis selected the cow-calf only phase of production in all scenarios.
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Doherty, Jennifer. "Continuing Professional Education in Athletic Training: Is Knowledge Acquired and Retained?" Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/118.
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Objective: The purpose of this study was to assess certified athletic trainers' knowledge acquisition, knowledge retention, and satisfaction, following a continuing professional education (CPE) program offered in either a traditional, lecture-oriented format or an interactive format addressing adult learning strategy preferences. Design: We used a pre-test, post-test experimental design with comparison groups utilizing stratified randomization. Setting: The CPE program was held in the University wellness center classrooms. Subjects: Forty-six certified athletic trainers participated. Measurements: After determination of learning strategy preferences, a 30 item multiple-choice exam was administered prior to, immediately after, and one-month following the CPE program to determine level of knowledge acquisition and retention. Participant self-reported level of satisfaction was assessed with a questionnaire immediately following the CPE program. Results: A significant main effect for treatment (F2,70 = 6.02, p < 0.004) was observed indicating that subjects in the lecture format CPE program acquired and retained more knowledge than subjects in the interactive format regardless of learning strategy preference. There was no significant loss in knowledge observed one-month following the CPE program regardless of learning strategy preference or treatment (lecture or interactive CPE format). No significant differences in level of satisfaction by treatment (lecture or interactive CPE format) or by learning strategy preference (navigators, problem-solvers, or navigators) were noted; however, 13 (28.3%) reported an excellent level of satisfaction (mean satisfaction score of 4.0) and 31 (67.4%) reported an above average level of satisfaction (mean satisfaction scores of 3.0 to 3.88). Conclusions: Our data indicate that lecture format CPE programs may be optimal for knowledge acquisition and retention, independent of learning strategy preference. Knowledge retention did not decrease regardless of learning strategy preference or CPE format and actually demonstrated a further increase using the lecture format. Although our data suggest that participant satisfaction is independent of learning strategy preference and CPE format, the homogeneity of responses made it difficult to detect any relationship with regard to learning style preference and satisfaction.
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Pahuja, Surbhi. "Bandwidth feedback effects on retained movements in young and old adults." Thesis, California State University, Long Beach, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1527573.
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<p> Feedback representing a performer's success for a given response has long been considered a critical factor in motor learning. Numerous studies of learning from augmented feedback have produced ambiguous guidelines for frequency design-some have recommended minimal feedback, whereas others have advocated more extensive feedback. Due to conflicting opinions regarding the frequency of Knowledge of Results, this study aimed to identify how young and old adults retain motor skills when two different frequency schedules of augmented feedback, everytrial and bandwidth are provided in acquisition. The participants performed a ballistic lever movement pattern involving four different target locations in a 1-day retention test. Behavioral outcomes and kinematic movement patterns were analyzed from two groups, young adults (20-30 years) and old adults (above 71 years) from a previously completed experiment. Results revealed that in both the age groups, bandwidth feedback promoted motor learning as compared to every-trial feedback. Further, bandwidth feedback promoted slower movements with longer durations as compared to an every-trial feedback schedule. Additionally, no significant interaction of age with any of the feedback conditions was found, suggesting that the effects of augmented feedback on motor learning are similar in young and old adults. </p>
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Harborth, Karl Walter. "Investigation of factors influencing feedlot performance and profitability in the 2001-2002 Texas A&M ranch to rail program- south." Texas A&M University, 2003. http://hdl.handle.net/1969.1/277.
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Data from the 2001-2002 Texas A&M University Ranch to Rail Program-South were used to determine factors that influence cattle feedlot performance and profitability. Steers (n=860) were classified according to sire (SBIO) and dam (DBIO) biological groups, kill groups (KILL), and entry month (ENTRYMON). Biological groups were determined by predominant genetic make up of the sire or dam. Traits evaluated included net income (NI), feedlot average daily gain (ADG), slaughter weight (OUTWT), carcass weight (CW), fat thickness (FT), longissimus muscle area (LMA), marbling score (MS), yield grade, (YG), medicine costs (TOTMED), and carcass value (CVL). Analyses of covariance were performed to determine differences between SBIO and DBIO, KILL, and ENTRYMON, and the influence of initial feedlot weight (INWT). Sire biological type had a significant effect on NI, ADG, FT, LMA, MS, YG, and CVL. Dam biological type and KILL had significant effects on all traits excluding TOTMED. Entry month accounted for no differences. Among SBIO groups, British-sired steers exhibited greatest values for ADG (1.39 kg/d), MS (457), FT (1.45 cm), CVL ($891), and NI ($25.62). Continental-sired steers exhibited the largest LMA (97.65 cm) and lowest YG (2.51). Brahman-sired steers exhibited the lowest ADG (1.32kg/d), MS (405), CVL ($859), and NI ($-17.80).
Multiple regression was performed to determine which traits had the greatest effect on CVL and NI. Independent categorical effects were SBIO, DBIO, KILL and ENTRYMON, while independent continuous effects were INWT, ADG, FT, LMA, MS and TOTMED. Both CVL and NI were influenced by CW, FT, LMA, and MS, but not by ADG, INWT, or TOTMED.
Phenotypic correlation coefficients were determined among all traits. Highest correlations were present between CVL: and NI, CW, ADG, and LMA (0.80, 0.81, 0.54, and 0.49, respectively). Strong correlations were seen between ADG and CW (0.63), FT and YG (0.87) and YG and LMA (-0.51). Marbling score was moderately correlated to CVL (0.30) and NI (0.30). This study indicates that a wide variety of traits interact to determine CVL and NI in retained ownership programs, and that maximizing carcass value does not ensure increased profitability.
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Jakobsson, Rikard. "Growth of retained Scots pines and their influence on the new stand /." Umeå : Dept. of Silviculture, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200534.pdf.
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Yalci, Hasan Kayhan. "The effect of retained austenite on hydrogen enbrittlement in high strength steels." Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315785.
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Lindroos, Robert. "A simplied Medium SpinyNeuron-model with retained intrinsic characteristics and plateau properties." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143499.
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This master thesis studies how a morphological reduction aects theperformance of a biophysically detailed model of a medium spiny neuron. Themorphological reduction is done using a MATLAB toolbox developed forautomatic 3-dimensional morphological reduction. Two versions of the toolboxare developed in which dierent criteria are used during the merge. Theevaluation of the two toolboxes shows that keeping the absolute distance to thesoma of the branching points and the surface area of the dendrites gives a moreaccurate result than if these criteria are not used. These criteria are implementedin Toolbox 2. In total 8 models with dierent maximal compartment length arethen constructed using Toolbox 2. The number of compartments in the resultingmodels range from 1/2 to 1/10 of the compartments in the original model. Furtherthe performance of the reduced models are evaluated against the original model.The results of this evaluation shows that an increasing compartment length givesa decrease in consistency with the response of the original model. However theresponse of all models are largely similar to the original model.<br>I detta examensarbete studeras hur en biofysikt detaljerad modell av en mediumspiny neuron (direkt oversatt "medellang taggig neuron") paverkas av en reduceringav dess strukturella komplexitet. Denna strukturella reduktion gar till saatt fragmenten som formar modellen slas samman och bildar nya fragment. Denya fragmenten far da en langd motsvarande summan av de sammanslagna fragmentenslangd. For att underlatta den strukturella reduktionen utvecklas ocksa enverktygslada till MATLAB. Verktygsladan ar byggd for att automatiskt reduceraden 3-dimensionella strukturen av en modell baserat pa vissa kriterier. Tva versionerav vertygsladan utvecklas i vilka kriterierna som anvands vid reduktionenskiljer sig fran varandra. Utvarderingen av de bada versionerna visar att omavstandet mellan cellkarnan och de dendritiska forgreningspunkterna samt dentotala dendritiska arean ar konstant sa uppnas ett battre resultat an om dessakriterier inte uppfylls. Dessa kriterier implementeras i den andra versionen avvertygsladan, Toolbox 2. Med hjalp av Toolbox 2 tillverkas sedan 8 reducerademodeller som alla har reducerad struktur men olika maximal langd pa fragmenten.De reducerade Modellerna ar uppbyggda av mellan 1/2 och 1/10 av antalet fragmenti den ursprungliga modellen. De reducerade modellerna jamfors sedan medden ursprungliga modellen. Resultatet av jamforelsen visar att med okad fragmentlangd kommer ocksa en gradvis storre avvikelse fran den ursprungliga modellen.Detta till trots gav alla reducerade modeller en overraskande bra respons ialla test de utsattes for.
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Hett, Anne. "Studies on the metabolism of retained and excised introns in human cells." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/10515.
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In eukaryotes the coding regions of most genes are interrupted by introns that must be removed by splicing to form a coding mRNA. However, while the splicing mechanism has received a lot of attention, much less is known about the metabolism of introns. This is partly due to the difficulties in studying introns as both aberrantly spliced transcripts and spliced introns are rapidly degraded. In this study, I have analysed intron metabolism in two respects: first I have investigated how introns are degraded following the completion of splicing. Second, I investigate the fate of transcripts, in which introns are retained due to splicing failure. In order to study the degradation of introns following splicing, I performed siRNA mediated knock down of the debrancing enzyme (Dbr1). Following splicing, introns are present in a circular lariat structure and Dbr1 is the enzyme thought to be responsible for opening this. Indeed, I found that knockdown of Dbr1 increased the amount of stabilised introns. Interestingly, introns were found to be stabilised in the cytoplasm and not in the nucleus as expected, even though immunofluoresence showed that Dbr1 is clearly nuclear. However, western blot analysis localised Dbr1 in the cytoplasm. Further investigation showed widely used methods to separate nuclear and cytoplasmic fractions are prone to generating artefacts which result in nucleoplasmic proteins delocalised to the cytoplasm. This finding may prevent future misinterpretation of data obtained by these methods. To investigate splicing failure, it was necessary to generated a sufficiently large pool of unspliced transcripts. To do this I used antisense morpholinos (AMOs) that bind to specific snRNAs (small nuclear RNAs). They are designed to block interaction surfaces that are important for splicing. Using this approach, I investigated the localisation of RNA transcripts and selected RNA processing and degradation factors in normal conditions and where splicing was inhibited. When splicing is inhibited I found splicing factors and unspliced, polyadenylated RNA localising to nuclear, splicing speckle marker SC35 positive speckles. I further discovered that for RNA to localise to nuclear speckles, polyadenylation and RNA cleavage are essential, indicating that SC-35 speckles might sequester unspliced transcripts preventing translation of potentially harmful transcripts. These transcripts remain functional however, and can be spliced where functional spliceosomes can be assembled.
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Shahdad, Shakeel. "The wear of different artificial denture teeth used in implant-retained prostheses." Thesis, University of Newcastle upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485797.
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Edentulous persons have been reported as 'oral invalids and very handicapped' in masticatory function. These patients are usually older people and can be successfully restored with implant-retained prostheses (IRP). However, a high rate of wear is apparent on the artificial teeth in IRP and opposing dentures necessitating prostheses to be remade partially or in total. Such maintenance has considerable clinical and laboratory cost implications, since it forms 1'. an increasing part of dentists' workload. The study investigated the wear rates among Various artificial tooth materials when subject to forces that represented those experienced in the clinical situation. The effect of abrasive slurry on the rate of wear was also investigated, as were the changes in hardness when artificial teeth were stored in food simulating solvents. A series of experiments was carried out in order to investigate these parameters on four commercially available Vivodent (VIV), Postaris (Del), Orthosit (aRT), Candulor (paR), and two experimental denture tooth materials; Experimental 1 (EXP1) and Experimental 2 (EXP2). Perspex (PER) was used as a control material. Two-body wear test A multi station wear-testing machine was constructed and used to test standardised hemispherical specimens against flat ones and measure the amount of wear using a non-contacting laser profiler to determine the depth of wear scar. Different material combinations were tested including materials worn against themselves and against hemispherical steatite abraders. Measurements were made following 2000 cycles and 10,000 cycles. Wearrates were determined as mean cross sectional area of the scar (Ilm/1 000 cycles). The results of this work revealed some interesting observations. Not all the specimens showed the classical wear pattern by creating a wear track on the flat specimen when the hemispherical abrader was sliding against it. Instead, in some material combinations there was a positive build up of material along the track and therefore a simple quantitative measurement of wear was not possible on all the specimens. The materials with a positive build up demonstrated an adhesive type of wear rather than the abrC?sive wear, which were further analysed under SEM. A technique was developed to measure wear occurring on hemispherical abraders. These were also qualitatively analysed under tool makers microscope and SEM. Abrasive and adhesive wear processes were noticed depending on the material combination tested. Three-body wear test Three-body abrasive wear tests were carried out on flat specimens using a toothbrushing machine with abrasive slurry. A laser profiler was used to measure the depth of wear scar. Measurements were made following 10,000 cycles except in porcelain specimens where measurements could only be recorded after 100,000 cycles. Wear rates were determined as mean depth mm/l 000 cycles. POR, EXPl and ORT demonstrated significantly (P<0.5) lower three-body wear rate when compared to the other materials. There was no significant difference in the wear rates between PER, VIV, DeL, and EXP2. Similarly, there was no significant difference between POR, EXPl and ORT. Effect of solvent storage on hardness The materials were tested for Martens Hardness measurements (HM) aHer storage in peppermint oil. 75% ethanol and heptane. Distilled water was used as a control storage medium. One specimen from each material group was stored in each solvent for 1 minute. 5 minutes. I hour. 24 hours. 1week and 1 month respectively. One specimen from each group was also tested dry to establish the baseline HM value. One-way ANOVA using Tukey's test on polymer based materials showed that the hardness of ORT and EXP 1 was significantly higher than the PMMA, Del and EXP2 (P<O.05). Moreover. EXPl had a significantly higher hardness value than ORT (P<O.05). Regression analysis showed that the polymer based materials showed a significant drop in hardness aHer storage in 75% ethanol (p<O.05). Specimens stored in water, heptane and peppermint oil showed minor fluctuations in hardness, which were not of statistical significance. Regression analysis performed on polymer-based materials between three-body wear resistance and hardness showed a statistically significant correlation (p<O.05). Conclusions The two-bOdy wear characteristics of some polymer-based materials when worn against themselves demonstrated a complex pattern of wear and quantitative measurement of wear scar in these specimens was not possible due to the positive build-up of material. It may be more important to describe the type of wear rather than the amount of wear occurring in some of the materials. The information from the wear characteristics is clinically relevant and should inform the clinician in choosing a material combination with better clinical performance. The three-body wear resistance of EXP 1and ORT is significantly greater than other polymer based materials. EXP 1 is significantly harder than other polymer based denture teeth and storage in ethanol leads to significant reduction in hardness in all materials except POR. EXPI and ORT have significantly better three-body wear resistance than other polymer-based materials tested. There is correlation between hardness and resistance to three-body wear in the selected polymer-based materials.
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Liddelow, Glen J. "The immediately loaded single implant retained mandibular overdenture : a 3 year prospective study." University of Western Australia. School of Dentistry, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0072.
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The purpose of this study was to ascertain whether simplifying mandibular overdenture treatment utilising single stage surgery and immediate prosthetic loading of a single implant, will achieve similar implant success rates and functional improvement to that expected using conventional techniques. As part of this study, the Mk III Brånemark implant with an oxidised surface (TiUnite Nobel Biocare AB, Göteborg, Sweden) was compared to the classical machined Mk III Brånemark fixture.Materials and Methods: 35 patients with a mean age of 68 years and problematic mandibular dentures were treated. The primary complaints among the patients referred to the clinic for treatment related to poor retention of the mandibular denture, instability, denture sores and phonetic problems. Patients were initially placed randomly into the machined surface or oxidised surface group. A single implant was placed into the mandibular midline with high initial stability. A ball attachment was placed and the retentive cap incorporated into the existing denture. Reviews took place at 3,12 6 6 and 36 months. Clinical assessments, radiographs made with custom film holders, and stability measurements by both manual and resonance frequency analysis methods were recorded. All complications, failures, maintenance and reasons for dropout were noted. Visual analogue scale questionnaires were utilised to record patient satisfaction. (ANOVA p<.05) Results: Three out of 8 machined surface implants failed, representing an unacceptably high failure rate (37.5%). The machined surface was therefore discontinued for this study. Three oxidised surface implants did not achieve sufficient primary stability to be immediately loaded, so were treated with a two stage delayed loading protocol. The 25 immediately loaded oxidised surface implants were all classified as surviving at the 36-month recall. Patient satisfaction was very high with a significant increase in all comfort and functional parameters. Conclusions: Within the limitations of this study and research design, it appears that the immediately loaded single implant retained mandibular overdenture, using an oxidised implant surface in a small group of maladaptive patients, can provide a beneficial treatment outcome over a three year observation period. If insufficient stability at insertion is not achieved for immediate loading, then a delayed loading protocol should be utilised.
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Oosthuizen, Gerhard. "Analysing cash retained by companies declaring scrip dividend on the Johannesburg Stock Exchange." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/5046.
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Thesis (MBA (Business Management))--University of Stellenbosch, 2009.<br>ENGLISH ABSTRACT: The research report investigated scrip dividends declared by companies on the Johannesburg Stock Exchange (JSE). Scrip dividends started becoming popular in 1993, due to the introduction of the secondary tax on companies (STC). The purpose of the study was to calculate the total amount of money not paid out as dividends, but retained within the company as cash. No single source could be found which provided sufficient dividend information. Eventually the JSE Monthly Bulletin, Reuters, McGregor BFA and the Hamman financial dataset had to be combined to collect a single set of scrip dividends. Changes in the number of shares issued were used as a way to calculate scrip dividends that were not available, or to crosscheck with the Hamman dataset. All along the way various validations were performed to ensure data consistency. For example, the percentage of shares for which scrip dividends were paid out was checked to ensure that the calculated amount of scrip shares issued were within acceptable boundaries. Furthermore, the equivalent scrip option value on the last date to register (LOR) was compared to the cash dividend option to ensure that the values were of equivalent sizes. In total, 754 scrip dividends were included in the report. For these dividends, R33 265 million was not paid out as cash dividends, but retained within the company. The equivalent share value of those shares on the LOR is R35 337 million. Only R19 576 million was paid as cash. This means that 63% of the total dividend payout was reinvested in the companies. Analysis of the LOR dates shows that 1995 to 1997 were the most popular years for scrip, with more than 130 cases every year. From 1994 to 2000, there were more than 40 scrip dividends every year. Not much has been written in South Africa about the impact and usage of scrip dividends. The research report has for the first time created a consolidated datasheet containing scrip dividend details, allowing further research. The R33 265 million reinvested in the economy has perhaps helped fuel the successful growth of the South African economy over the last 10 years.<br>AFRIKAANSE OPSOMMING: Die navorsingsverslag ondersoek skripdividende wat verklaar is deur maatskappye op die Johannesburgse Effektebeurs (JSE). Skripdividende het gewild begin raak in 1993 as gevolg van die bekendstelling van sekondêre belasting op maatskappye (STC). Die doel was om die totale kontantbedrag te bereken wat behou is in die maatskappy, en dus nie uitbetaal is as dividende nie. Geen enkele bron kon gevind word wat volledige inligting oor skripdividende bevat het nie. Uiteindelik is die JSE Monthly Bulletin, Reuters, McGregor BFA en die Hamman finansiele datastel gekombineer in 'n enkele versameling van skrip dividende. Veranderinge in the totale hoeveelheid uitgereikte aandele is gebruik as 'n manier om die skrip aandele wat uitgereik is te bereken, en te korrelleer met die Hamman datastel. Gedurende die dataversamelingsproses is daar verskeie toetsdatapunte
bereken, om die data integriteit te verseker. Byvoorbeeld, die persentasie aandele waarvoor skrip uitgereik is, is geverifieer om seker te maak dat die berekende hoeveelheid skrip aandele binne geldige grense was. Verder is die kontantwaarde van die skrip aandeel, soos op die laaste dag van registrasie (LOR), vergelyk met die kontant dividendopsie, om te verifieer dat die waardes van soortgelyke groottes was. In totaal is daar 754 skripdividende ingesluit in die verslag. Vir hierdie dividende is R33 265 miljoen nie uitbetaal as kontant dividende nie, maar as skrip aandele. Die ekwivalente aandeelwaardes van hierdie uitgereikte aandele op die LOR was R35 337 miljoen. Slegs R19 576 miljoen is uitbetaal as kontant. Dit beteken dat 63%
van die totale dividenduitbetaling herbelê is in die maatskappye as skrip-aandele. Analise van die dividend LDR datums wys dat 1995 tot 1997 die gewildste jare was vir skrip, met meer as 130 gevalle per jaar. Van 1994 tot 2000 is daar elke jaar meer as 40 skripdividende uitgereik. Daar is nog nie veel oor die impak en gebruik van skripdividende in Suid-Afrika geskryf nie. Die navorsingsverslag het vir die eerste keer 'n gekonsolideerde skripdividend datastel geskep waarmee verdere navorsing gedoen kan word. Die R33 265 miljoen wat herbelê is in die ekonomie het moontlik bygedra tot die ongekende groei in die Suid-Afrikaanse ekonomie oor die laaste 10 jaar.
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Mark, Alison Fiona Lockie. "Microstructural effects on the stability of retained austenite in transformation induced plasticity steels." Thesis, Kingston, Ont. : [s.n.], 2007. http://hdl.handle.net/1974/960.
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Adams, Derrik David. "Characterization of the Factors Influencing Retained Austenite Transformation in Q&P Steels." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8425.
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Formable Advanced High-Strength Steels (AHSS) have a unique combination of strength and ductility, making them ideal in the effort to lightweight vehicles. The AHSS in this study, Quenched and Partitioned 1180, rely on the Transformation Induced Plasticity (TRIP) effect, in which retained austenite (RA) grains transform to martensite during plastic deformation, providing extra ductility via the transformation event. Understanding the factors involved in RA transformation, such as local strain and grain attributes, is therefore key to optimizing the microstructure of these steels. This research seeks to increase understanding of those attributes and the correlations between microstructure and RA transformation in TRIP steels. To measure local strain, the viability of using forescatter detector (FSD) images as the basis for DIC study is investigated. Standard FSD techniques, along with an integrated EBSD / FSD approach (Pattern Region of Interest Analysis System), are both analyzed. Simultaneous strain and microstructure maps are obtained for tensile deformation up to around 6% strain. The method does not give sub-grain resolution, and surface feature evolution prevents DIC analysis across large strain steps; however, the data is easy to obtain and provides a natural set of complementary information for the EBSD analysis. In-situ tensile tests combined with EBSD allow RA grain and neighboring attributes to be characterized and corresponding transformation data to be obtained. However, pseudo-symmetry of the ferrite (BCC) and martensite (BCT) phases prevents EBSD from accurately identifying all phases. Measuring the relative distortion of the crystal lattice, tetragonality, is one approach to identifying the phases. Unfortunately, small errors in the pattern center can cause significant errors in tetragonality measurement. Therefore, this research utilizes a new approach for accurate pattern center determination using a strain minimization routine and applies it to tetragonality maps for phase identification. Tetragonality maps based on dynamically simulated patterns result in the most accurate maps and can also be used to predict approximate local carbon content. Machine learning is then used on the collected data to isolate key attributes of RA grains and provide a decision tree model to predict transformation based on those attributes. Among the most relevant attributes found, RA grain area, RA grain shape aspect ratio, a “hardness” factor, and major axis orientation are included. Possible correlations between these factors and transformation improve understanding of relevant attributes and show the advantage that machine learning can have in unravelling complex material behavior.
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Van, Deventer David. "Discrimination of Retained Solvent Levels in Printed Food-Packaging Using Electronic Nose Systems." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/9741.
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The expanding role of electronic nose instrumentation, as a quality-monitoring tool for food-packaging materials, is examined and reviewed. The food industry is interested in determining the applicability of using an electronic nose for odor analysis of retained printing solvent levels in packaging. Three electronic nose systems were optimized for this application and their performance assessed. These include the FOX 3000, the Cyranose 320, and the QMB6.
Response surface methodology was used to generate 2nd order models of sensor response as a function of system and experimental parameters for the three electronic nose systems. Forty-seven of 50 sensor models generated were found to be significant at an a-level of 0.05. Optimum settings, that allowed adequate signals to be obtained for the full range of examined retained solvents levels, were selected for the remaining work using these models.
Performance analyses of these systems, which use three leading sensor technologies, showed that the conducting polymer sensor technology demonstrated the most discriminatory power. All three technologies proved able to discriminate among different levels of retained solvents. Each complete electronic nose system was also able to discriminate between assorted packaging having either conforming or non-conforming levels of retained solvents. Each system correctly identified 100% of unknown samples. Sensor technology had a greater effect on performance than the number of sensors used. Based on discriminatory power and practical features, the FOX 3000 and the Cyranose 320 were superior. The results indicate that electronic nose instrumentation can be used as a complimentary discriminatory tool in quality control.<br>Master of Science
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Gustavsson, Jonatan. "The effect of task relevancy in non-consciously retained information in working memory." Thesis, Umeå universitet, Institutionen för psykologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-136468.
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The relationship between cognitive processes and consciousness has been of interest for a long time in the science community. Recent studies showed that it’s possible to non-consciously retain information in working memory. This study aimed to replicate previous findings, and to investigate the effect of task relevancy to the retention of non-conscious information. This study used a delayed-match-to-sample task with a cue manipulating the attention, and continuous flash suppression to render the perceptual experience non-conscious on 16 participants. Analyses showed that cue validity affected the accuracy performance and response time for items reported not seen. Implications of study design, results and theories are deliberated in the discussion.
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Nunes, Rodolfo Filipe Damásio. "Reabilitação fixa aparafusada Vs. reabilitação fixa cimentada." Master's thesis, [s.n.], 2014. http://hdl.handle.net/10284/5255.
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária<br>A reabilitação fixa é a arte e a ciência de, de forma artificial, reabilitar dentes danificados ou espaços edêntulos da cavidade oral através de peças metálicas, metalo-cerâmicas ou totalmente cerâmicas.
No caso de as lesões estarem localizadas apenas na zona da coroa e/ou existirem espaços edêntulos pequenos, as reabilitações são dento-suportadas e a união entre as peças dentárias e a reabilitação é feita através de técnicas de cimentação. No caso de espaços edêntulos extensos, estas reabilitações são aparafusadas a implantes dentários.
Os implantes dentários, ao longo dos anos, têm vindo a ser alvo de um extenso estudo e melhoramento das suas propriedades de biocompatibilidade, sendo atualmente um método de reabilitação com uma taxa de sucesso superior a 90%.
Dado as atuais taxas de sucesso de biocompatibilidade dos implantes, a necessidade de recuperação das reabilitações como fator primordial para o desenho destas passou para um plano secundário, dando-se cada vez mais importância a outros fatores como a estética, oclusão, função e passividade que estavam relegados num plano secundário.
Com este trabalho pretendeu-se fazer uma sistematização da bibliografia atual sobre este tema de forma a poder avaliar as vantagens e desvantagens de cada sistema ao nível dos conhecimentos e técnicas atuais.
A pesquisa bibliográfica do presente projeto de pós-graduação foi realizada recorrendo-se à biblioteca da Faculdade de Medicina Dentária da Universidade de Lisboa, biblioteca da Faculdade de Medicina Dentária da Universidade do Porto e a diversos motores de busca online, nomeadamente, Pubmed, Scielo, Mesh Database e Science Direct, utilizando como palavras-chave: “cement”, “screw”, “fix”, “retained”, “implant”, “restoration”, “retention”, que foram associados de diversas formas selecionando-se 154 artigos. Foram ainda consultados 5 livros.
Como principais conclusões deste trabalho pode-se afirmar que atualmente o melhor tipo de retenção para reabilitações implanto-suportadas é a retenção por cimentação, embora na literatura não haja uma clara evidência relativamente a aparafusada, além de que, as reabilitações cimentadas são mais sensíveis e o clínico necessita ter alguma experiência para dominar corretamente esta técnica ao contrário das técnicas aparafusadas.<br>The fixed rehabilitation is the art and science of artificially, rehabilitate damaged teeth or edentulous areas of the oral cavity through metal structures, metal-ceramic or all-ceramic structures.
In cases where the lesions are located only in the region of the corona and / or there are small edentulous spaces, the rehabs are tooth-supported and the union between the dental pieces and rehabilitation is done by cementation techniques. In the case of extensive edentulous spaces, these restorations are screwed to dental implants.
Dental implants, over the years, have been the subject of extensive study and improvement of their biocompatibility properties, currently a rehabilitation method with a success rate over 90%.
Given the current success rates of biocompatibility of implants, the need for recovery of rehabilitations as primary factor for the design of these went to a secondary plan, giving more importance to other factors such as aesthetics, occlusion, function and passivity that were relegated to a secondary plan.
This work aims to make a systematization of the current literature on this subject in order to be able to evaluate the advantages and disadvantages of each system at the level of current knowledge and techniques.
The bibliographic research of this graduate project was performed using to the library of the Faculdade de Medicna Dentária da Universidade de Lisboa, library of the Faculdade de Medicina Dentáriada Univerisade do Porto and various online search engines, in particular, Pubmed, Scielo , Mesh Database and Science Direct, using as keywords: "cement", "screw", "fix", "retained", "implant", "restoration", "retention", which were associated
in various ways and 154 articles were selected. 5 books were consulted also.
The main conclusions of this work can be said that currently the best type of retention for implant-supported restorations is the retention by cementing, although in the literature there is no clear evidence for screwed, and that cemented the rehabs are more sensitive and the clinician needs to have some experience to properly master this technique instead of screw techniques.
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Honda, Masaki J., Takashi Hatanaka, Yasuhiro Okazaki, and Minoru Ueda. "Long-term results of osseointegrated implant-retained facial prostheses: a 5-year retrospective study." Nagoya University School of Medicine, 2005. http://hdl.handle.net/2237/5411.
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Al-Makki, Amjad. "A comparative study to evaluate patient satisfaction with conventional dentures and implant retained overdentures." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3748_1204268777.
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<p><span style="font-size: 8pt<br>" text-align:="" font-family:="" color:="">The edentulous jaw is a common feature in elderly patients that had lost their teeth during life due to local reasons such as poor oral hygiene and dental caries as well as periodontal disease. Hence these patients are the victims of biological phenomenona that lead to difficulties in different aspects of patient comfort with dentures. Clinicians are always concerned to minimize these difficulties and increase patient comfort through manufacturing a proper prosthesis to substitute for the loss of the natural teeth as well as the surrounding structures for optimum satisfaction and improved quality of life of the patient. The aim of this study was to evaluate patient satisfaction regarding function and aesthetics with conventional mandibular dentures and implant retained mandibular overdentures in denture wearers.</span></p>
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Malmberg, Andreas. "The influence of carbonitriding on hardness, retained austenite and residual stress in 52100 steel." Thesis, KTH, Materialvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-173804.
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High rolling contact fatigue parts are vital for the long service life of fuel pumps. Cummins Fuel Systems are currently using an M2 tool steel for one of the most important roller bearing application in their pumps, namely the cam follower. The future design of the cam follower is a pin-less tappet roller. The wear and fatigue properties of the roller is vital to ensure reliability of the fuel system. M2 tool steel is an expensive material and becomes even more so if diamond like coating (DLC) is needed to decrease the friction coefficients. To cut costs of the fuel pump it might be possible to replace the M2 tool steel with 52100 steel (100Cr6). Competitive methods have proven that carbonitrided 52100 can reach excellent wear and fatigue properties making it a candidate to replace M2 tool steel. How the properties of hardness, toughness and compressive residual stresses are developed in 52100 and how they affect the fatigue and wear resistance has been researched from the literature. A big part of this project was to do an extensive analysis of a roller bearing that was believed to have gone through one of these competitive methods that produce excellent wear and fatigue resistance. The analysis was done with background to the knowledge gathered from the literature. Finally process trials were set up to carbonitride 52100 steel samples. The trials were done to develop a better understanding of how adding carbon together with nitrogen to the surface of 52100 steel will influence the metallurgical parameters that results in good wear and fatigue resistance. From this analysis Cummins hope to create a process recipe that can be used for carbonitriding the cam follower and maybe other components in their fuel systems.
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Björklund, Erik. "The Influence of Hardness and Retained Austenite on the Fatigue Limit after Shot Peening." Thesis, Uppsala universitet, Institutionen för kemi - Ångström, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-221610.
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This thesis was performed at Scania CV AB and aimed to optimize the effect of shot peening in order to increase the bending fatigue limit of planetary gears. In this project three parameters affecting the performance of the shot peening were examined in more detail, specifically the hardness of the shot peening media, the hardness of the material and the amount retained austenite. Shot peening and measurements were performed on carburized gears consisting of ss 92506 steel. In order to find out how the fatigue limit is affected by the material hardness, a number of gears were tempered whereas other remained untempered. Similarly the retained austenite content was altered in some of the gears with a cryotreatment. The shot peening of these gears was performed by dual shot peening using media of two different hardness. The fatigue limit was evaluated by a servo hydraulic material testing machine. The results show that the fatigue limit is enhanced when the shot peening was performed with hard media. This was expected since the harder media can cause larger plastic deformation in the material giving rise to larger compressive residual stresses which is known to increase the fatigue limit. The fatigue limit was also improved for samples with lower surface hardness. The amount of retained austenite does not seem to affect the fatigue limit for samples shot peened with media of sufficient hardness in order to cause adequate plastic deformation. The surface roughness remained unchanged for samples shot peened by different media, which indicates that this parameter should not hinder a change of media.
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Bahmann, Helge. "A network transparent, retained mode multimedia processing framework for the Linux operating system environment." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2009. http://nbn-resolving.de/urn:nbn:de:bsz:105-967869.
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Die Arbeit präsentiert ein Multimedia-Framework für Linux, das im Unterschied zu früheren Arbeiten auf den Ideen "retained-mode processing" und "lazy evaluation" basiert: Statt Transformationen unmittelbar auszuführen, wird eine abstrakte Repräsentation aller Medienelemente aufgebaut. "renderer"-Treiber fungieren als Übersetzer, die diese Darstellung zur Laufzeit in konkrete Operationen umsetzen, wobei das Datenmodell zahlreiche Optimierungen zur Reduktion der Anzahl der Schritte oder der Minimierung von Kommunikation erlaubt. Dies erlaubt ein stark vereinfachtes Programmiermodell bei gleichzeitiger Effizienzsteigerung. "renderer"-Treiber können zur Ausführung von Transformationen den lokalen Prozessor verwenden, oder können die Operationen delegieren. In der Arbeit wird eine Erweiterung des X Window Systems um Mechanismen zur Medienverarbeitung vorgestellt, sowie ein "renderer"-Treiber, der diese zur Delegation der Verarbeitung nutzt.
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Hoshino, Isis Almela Endo. "Análise da performance mecânico-estrutural e resistência de união de diferentes técnicas de utilização de pinos de fibra de vidro. /." Araçatuba, 2019. http://hdl.handle.net/11449/183207.
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Orientador: Rodolfo Bruniera Anchieta<br>Resumo: O objetivo deste trabalho foi avaliar “in vitro” e “in silico” a integridade estrutural da interface de cimentação, o comportamento biomecânico, e a resistência de união da interface dentina/cimento de diferentes técnicas de cimentação de pinos de fibra de vidro (PFV) em canais amplos. Para tanto, foram utilizados 33 incisivos bovinos. Após o tratamento endodôntico, os espécimes foram divididos aleatoriamente em três grupos (n=11): PCN- Pino convencional cimentado em dente com conduto normal; PCA- Pino convencional cimentado em dente com conduto amplo; PAA- Pino anatômico cimentado em dente com conduto amplo. Em seguida, foram executados os preparos intrarradiculares de acordo com cada grupo com brocas pré-estabelecidas, tratamento de superfície dos PFV (WhitePost nº3 DC, FGM) e cimentação dos mesmos com o cimento resinoso autoadesivo (Rely X U200, 3M ESPE). Então, 6 espécimes de cada grupo foram submetidos ao escaneamento em um microtomógrafo de alta resolução (SkyScan 1272) para avaliação da integridade, volume e presença de bolhas na interface de cimentação. Posteriormente, com base nos dados do µCT e imagens de microscopia (n=1), dois modelos tridimensionais de cada grupo foram confeccionados para a análise de elementos finitos, sendo que o primeiro foi considerado ideal (G1, G3 e G5), sem defeitos na interface, e o segundo continha as condições encontradas pela análise de µCT(G2, G4 e G6). Após o envelhecimento em estufa por 7 meses, todos os espécimes foram submetidos a... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The objective of this study was to evaluate “in vitro” and “in silico” the structural integrity of the cementation interface, the biomechanical behavior and the bond strength of different fiberglass post cementation techniques in flared root canal. To this end, 33 bovine incisors were used. After the endodontic treatment, the specimens were randomly divided into three groups (n = 11): PCN - conventional post cemented in tooth with normal canal lumen; PCA- Conventional fiberglass post cemented in flared root canal; PAA- Fiberglass post relined with composite resin and cemented in flared root canal; Then, the intra-radicular preparations were performed according to each group with pre-established drills, surface treatment of PFV (WhitePost Nº. 3DC, FGM) and cementation with self-adhesive resin cement (Rely X U200, 3M ESPE). Then, 6 specimens from each group were submitted to scanning in a high resolution microtomograph (SkyScan 1272) to evaluate the integrity, volume and presence of bubbles at the cementation interface. Then, based on the μCT data and the microscopic images (n = 1), two three-dimensional models of each group were made to analyze finite elements, the first one being considered ideal (G1, G3 and G5), without interface defects and the second contained the conditions found by μCT analysis (G2, G4 and G6). After being stored for 7 months, all specimens were submitted to the pushout bond strength test (n = 10). Data were submitted to ANOVA with repeated measures and ... (Complete abstract click electronic access below)<br>Mestre
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Ahn, Minkwan. "The Market’s View on Accounting Classifications for Asset Securitizations." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1402581668.
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Al-Omoush, Salah Abdullah. "Psychometric and oral function assessment of patients treated by the use of implant-retained prostheses." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368221.
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Armstrong-Stassen, Marjorie Augusta. "The impact of work-force reduction on retained employees : how well do job survivors survive?" The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1277406310.
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Tsan-Ming, Su, and 蘇燦明. "The Development of Physical Vapor Deposition Technique and Testing on Dental Ceramics and Retainers." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/k63z2z.
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碩士<br>大葉大學<br>醫療器材設計與材料碩士學位學程<br>105<br>In this study, ZrN thin films were grown by cathodic arc deposition on the dental materials consisting of Al2O3 ceramics and Co-Cr-Mo alloy stents to improve their mechanical properties of these dental materials. During the growth process, some deposition conditions such as the N2/Ar gas flow ratio, bias voltage, and film thickness were modified to obtain the ZrN films with various crystal structures and mechanical characteristics. The adhesion properties between ZrN films and these dental materials were analyzed via the scratch track tests. Moreover, the stiffnesses of these dental materials coated with the ZrN films can be investigated through the microhardness tests. After the analyses of mechanical properties and the surface observations for these ZrN-coated samples, the optimum deposition conditions of ZrN films can be achieved and used in dental materials.
Crystal structures and thicknesses of ZrN films were measured by x-ray diffraction and scanning electron microscopy, respectively. After the ZrN growth with the optimum conditions, the mechanical properties of Al2O3 ceramics and Co-Cr-Mo alloys were enhanced significantly. The cathodic arc deposited ZrN films possess the excellent compactness, adhesion, and wear resistance, which can improve the mechanical properties of these dental materials. Thus, the problem of pre-crack in the Al2O3 ceramics and the disadvantage of easy deformation in the Co-Cr-Mo alloy stents can be both solved. This indicates the cathodic arc deposited ZrN films are highly potential for dental applications.
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林文煌. "Correlation Analysis of Retained Ratio and Retained Loss for Property Insurance." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/08667417425010597348.
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碩士<br>國立政治大學<br>風險管理與保險研究所<br>91<br>Retention is a key element for the insurer to determine how much it wishes to retain for its own account for the risks it has written. This point is fundamental to carrying on the business of insurance and akin to the principle upon which insurance is based, namely the spreading of risks and sharing of losses. The risk of incurring a retained loss owning to inadequate retention, which would imperil financial objective even can affect the overall underwriting results and arise insolvency. This paper select data base of occurred loss distribution for the past three years to study the impact of different retained ratio and different type of reinsurance for performance. This paper shows that, the underwriting profit can be expected to increase when the retention increases precisely under the existing loss distribution model . This paper also discuss the related factors in deciding retention by correlation analysis.
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Chen, Ming-Fei, and 陳明飛. "Mandibular Implant-Retained Overdenture." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/08001073489745642865.
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碩士<br>高雄醫學大學<br>牙醫學研究所碩士在職專班<br>98<br>As the definition of periodontal prosthesis from Morton Amsterdam in 1974.“Those restorative prosthetic endeavors that are absolutely essential in the treatment of advanced periodontal disease. Whereas specifically it refers to the treatment of the dentition mutilated by the ravages of periodontal disease, in general, its concepts, principles, and techniques may be employed in any restorative or tooth replacement service involving the nature dentition.” The periodontal patients with destruction of periodontal support results in various complicated oral problems, such as the increase of tooth mobility, as well as bite collapse and occlusal plane disharmony caused by missing teeth. They could be benefited thoroughly from multidisciplinary treatments for examples periodontics, endodontics, orthodontics, oral surgery, prosthodontics etc. Via the development of more than 30 years, the category of periodontal prosthesis treatment integrated gradually periodontology, prosthodontology, endodontology, orthodontology, implantology and etc to satisfy human demand of maxillofacial esthetic and function. So, we can say “Not limit to advanced periodontal involved patients, dentists should give treatment plan in periodontal prosthesis philosophy for those who need maxillofacial esthetic or function.”
In this thesis, nine cases involving mild, medium to comprehensive periodontal prosthesis are presented. These cases were completed through the treatment protocols such as initial phase, re-evaluation, surgical phase, prosthetic phase and maintenance phase. In according to their main complaints and concern, also considered the patients physical health conditions and financial status. Finally, the oral health, function of mastication, and esthetics of these patients were restored.