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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Uso de infiltrante sobre esmalte hígido e com lesão inicial de erosão submetido a desafio erosivo in vitro

Oliveira, Gabriela Cristina de 28 May 2013 (has links)
O presente trabalho teve como objetivo avaliar in vitro a eficácia da aplicação do infiltrante comparativamente a um selante e dois sistemas adesivos na prevenção (etapa 1 esmalte hígido) e na inibição da progressão de lesões erosivas iniciais de esmalte associado ou não ao condicionamento da superfície de esmalte previamente à aplicação dos materiais (etapa 2). Os espécimes foram preparados a partir de esmalte bovino. Na etapa 1 (prevenção), as superfícies de esmalte hígidos (H) foram aleatoriamente divididos em 5 grupos, de acordo com o material aplicado: HCn sem tratamento controle negativo, HH aplicação de selante resinoso de fossas e fissuras Helioseal Clear®, HA aplicação de sistema adesivo autocondicionante Adhese®, HT aplicação de sistema adesivo convencional Tetric N-bond®, HI aplicação de infiltrante Icon®. Na etapa 2, todos os espécimes foram inicialmente imersos em HCl 0,01M, pH2,3 por 30 s, simulando a lesão inicial de erosão, e posteriormente aleatorizados em 9 grupos (E). Nos grupos ECn, EH, EA, ET e EI, os espécimes foram tratados com os mesmos materiais respectivamente, seguindo as recomendações dos fabricantes e nos grupos EHs, EAs, ETs e EIs não houve condicionamento da superfície de esmalte. Para as duas etapas, todos dos espécimes após tratamento, foram submetidos à ciclagem erosiva, pela imersão dos espécimes 4x/dia por 5 dias em ácido clorídrico (0,01M; pH 2,3) por 2 minutos, seguida da imersão em saliva artificial por 120 min e overnight. O desgaste do esmalte e a análise de espessura dos materiais foram avaliados por perfilometria e os resultados submetidos à Kruskal-Wallis e Teste de Dunn (p<0,05). Na etapa 1, o infiltrante (HI), selante (HH) e adesivo autocondicionante (HA) protegeram o esmalte contra a erosão e foram significativamente diferentes do controle, sendo efetivos na prevenção da erosão. Na etapa 2, os grupos EH, EA, EI (selante, adesivo autocondicionante, infiltrante), ETs e Eis (adesivo convencional e infiltrante, ambos sem condicionamento ácido), foram semelhantes e não promoveram alteração no esmalte, sendo os mais eficazes na inibição da progressão da erosão. Maior desgaste do esmalte foi observado nos grupos ECn ( sem tratamento controle negativo), ET ( sistema adesivo convencional de 2 passos), EHs (selante resinoso de fossas e fissuras sem condicionamento ácido), EAs (sistema adesivo autocondicionante sem condicionamento ácido), sendo estatisticamente similares. Considerando os resultados conclui-se que a aplicação de infiltrante Icon® (com ou sem condicionamento do esmalte) e de selante de fossas e fissuras Helioseal Clear®, sobre o esmalte hígido ou com lesão inicial de erosão foram efetivos para prevenir e inibir a progressão erosiva. / This study aimed to evaluate in vitro the efficacy of the application of infiltrant, compared to sealant and two different adhesive systems on prevention (phase 1 - sound enamel) and inhibition of the progression of erosive lesions associated or no the enamel surface conditioning prior to application of the material (phase 2). The specimens were prepared from bovine enamel. In phase 1 (prevention), the sound enamel surface (H) were randomly divided into 5 groups according to the material used: HCN untreated - negative control, HH application of resin sealant - Helioseal Clear®, HA application of self-etching adhesive system - AdheSE®, HT application of phosphoric acid-etching adhesive system - Tetric Nbond ®, HI application of infiltrant - Icon®. In phase 2, all specimens were eroded by immersion in 0.01 M HCl, pH 2,3 for 30 s to simulate initial erosion lesion, and then randomized into 9 groups (E). In groups ECn, EH, EA, ET and EI, the specimens were treated with the same materials, respectively, following the manufacturers recommendations and the groups, EHs, EAs, ETs e EIs no enamel surface conditioning was performed. For both phases, all blocks were subjected to erosive cycling by immersion of the blocks in hydrochloric acid (0.01 M, pH 2.3) for 2 minutes, followed by immersion in artificial saliva for 120 minutes 4x/day for 5 days. The enamel alteration was evaluated by profilometry and the results subjected to Kruskal-Wallis and the Dunns test (p <0.05). In phase 1, the infiltrant (HI), sealant (HH) and self-etching adhesive (HA) protected the enamel against erosion and were significantly different from control. In phase 2, the groups EH, EA, EI (sealant, selfetching adhesive, infiltrant), ETs and EIs (phosphoric acid-etching adhesive and infiltrant, both without surface conditioning) were similar and showed no enamel alteration after erosion. Greater enamel wear was observed in groups ECn (untreated - negative control), ET (phosphoric acid-etching adhesive), EHs (resin sealant without surface conditioning), AEs (self-etching adhesive without surface conditioning) and these were statistically similar. Taking into consideration the results, it is concluded that the application of infiltrant (with or without prior enamel conditioning) and sealants on sound and initially eroded enamel, prevented enamel alterations when subjected to erosive challenge.
22

Avaliação da influência da aplicação de um selante de superfície no comportamento clínico de restaurações de resina composta classe I / Evaluation of the influence of a surface sealant in the clinical behavior of composite resin class I restorations

Nahsan, Flávia Pardo Salata 24 August 2012 (has links)
A aplicação de selantes de superfície, através da penetração nas irregularidades superficiais e na interface dente/restauração, é realizada ao final do procedimento restaurador e pode minimizar algumas limitações, prolongando a longevidade clínica das restaurações de resina composta. Este estudo clinico randomizado se propôs a avaliar o efeito da aplicação de um selante de superfície no comportamento clínico de restaurações posteriores de resina composta do tipo classe I. Vinte e sete pares de dentes molares ou pré-molares, superiores ou inferiores, que apresentavam lesões de cárie (classe I) ou restaurações de amálgama ou resina composta (classe I) insatisfatórias, que necessitavam de substituição completa, foram aleatorizados e preparados e restaurados com a resina composta Esthet-X. Sobre a superfície da resina de apenas um dente de cada par foi aplicado o selante de superfície Lasting Touch utilizando o modelo experimental de boca dividida. A avaliação única foi realizada empregando-se o método direto USHPS modificado, nos tempos: baseline, 6 meses, 12 meses, por dois operadores. Radiografias interproximais e réplicas das faces oclusais foram obtidas por meio da moldagem com silicona de adição e vazadas com resina epóxica para avaliação qualitativa com Microscópio Eletrônico de Varredura. Os dados foram submetidos ao teste de Mc Nemar (p<0,05). Para a integridade marginal, após 6 meses de avaliação, apenas 1 (4%) restauração do grupo com selante de superfície recebeu o escore Bravo. Aos 12 meses, a integridade marginal apresentou 1 (4%) do grupo sem selante e 2 (7%) restaurações com selante com escore Bravo. Os resultado apresentados nos períodos de avaliação não apresentaram diferenças estatisticamente significantes (p=1,0, para todas as condições. Não houve diferença no desempenho clínico de restaurações de resina composta com e sem selante de superfície, sendo aceitáveis após 12 meses de avaliação. As observações em MEV demonstraram que aplicação do selante de superfície promove superfícies mais lisas e regulares para todos os tempos avaliados. Em um período de 12 meses, o selante de superfície mostrou estabilidade na condição avaliada. O Mev, entretanto, não demonstrou superioridade ao grupo sem a aplicação de selante de superfície (controle). / The finishing, polishing and surface sealant application, by superficial irregular penetration and between restoration interface, are applied at the end of the restoration and decrease these limitations, and extend the clinical longevity of composite resin restorations. This clinical randomized controled study however aimed to evaluate the effect of the surface sealant application in the clinical behavior of composite posterior resin class I restorations. Twenty seven pairs of upper or lower molars or premolars with carious lesions (class I), and unsatisfactory amalgam or composite resin restorations, which needed total replacement, were randomized and prepared and restored with Esthet X composite resin. The composite resin surface of one tooth from each pair was covered with Lasting Touch surface sealant (Split Mouth Design). The clinical evaluation was made by using the modified direct method USPHS, at the following times: baseline, 6 months and 12 months, by two different operators. Bitewing radiographs and replicas of the occlusal surfaces were obtained by using a silicone impression material poured with epoxy resin for the qualitative evaluation with Scanning Electron Microscopy. The data was analyzed with the McNemar test (p <0.05). Results showed that for the marginal integrity, after 6-month evaluation, only 1 (4%) sealed restoration had a Bravo rating. At the end of 12 months, the marginal integrity showed 1 (4%) sealed restoration and 2 (7%) non sealed Bravo restorations. Results at all evaluations periods did not show statistical significant differences (p=1.0) for all conditions. There was no difference in the clinical performance of the composite resin restorations (Esthet X) with or without the surface sealant (Lasting Touch), demonstrated good behavior after 12 months. Based on SEM examinations, the surface sealant application promoted a regular and smooth surface, for all the evaluation times. In a 12 months evaluations period, the surface sealant demonstrated stability at the evaluated condition. The SEM, however, did not presented better conditions in the no sealant application group (control).
23

Impacto nos resultados assistenciais e nos custos hospitalares do emprego do selante de fibrina na anastomose pancreatojejunal após ressecção duodenopancreática / Impact on health care outcomes and hospital costs of the use of fibrin sealant in pancreatojejunal anastomosis after duodenopancreatic resection

Alberto Facury Gaspar 15 May 2015 (has links)
Introdução: Os benefícios do emprego do selante de fibrina no reforço de anastomoses pancreatico-jejunais, após ressecção duodenopancreática, visando a redução da incidência de fístula pancreática pós operatória (FPPO), ainda são questionáveis. Objetivo: Avaliar a influência do emprego do selante de fibrina na anastomose pancreatico-jejunal, após duodenopancreatectomia, na incidência de fístula, bem como suas consequências clínicas e os custos hospitalares. Metodologia: Estudo retrospectivo de 62 pacientes consecutivos submetidos a duodenopancreatectomia, divididos em dois grupos: 31 pacientes utilizando o selante de fibrina (GCS) e 31 pacientes sem o emprego de selante (GSS). As variáveis estudadas foram agrupadas em epidemiológicas, clínicas, laboratoriais, com destaque para a incidência de fístula pancreática, classificada segundo a definição do International Study Group on Pancreatic Fistula, suas complicações pós operatórias catalogadas segundo a classificação de Clavien e suas repercussões na assistência e nos seus custos avaliados pelo método de absorção com rateio simples de todas as despesas, exceto a despesa com medicamentos, tratada de forma separada. Resultados: Os grupos foram homogêneos para os parâmetros epidemiológicos, clínicos, e laboratoriais e não foram registradas diferenças significativas na comparação da evolução pós operatória e dos indicadores assistenciais hospitalares. Por outro lado, os custos hospitalares foram mais elevados no GCS, em relação ao GSS (p<0,0001). Conclusão: O emprego do selante de fibrina, no reforço da anastomose pancreatico-jejunal, em pacientes submetidos a duodenopancreatectomias, nas condições estudadas, não melhorou os resultados clínicos e assistenciais e ainda aumentou os custos hospitalares. / Introduction: The benefits of fibrin sealant employment in strengthening pancreatico-jejunal anastomosis after duodenopancreatic resection, reducing the incidence of pancreatic fistula postoperative (PFPO) are still questionable. Objective: To evaluate the influence of the use of fibrin sealant in pancreatico-jejunal anastomosis after pancreaticoduodenectomy in the incidence of fistula and its clinical consequences and hospital costs. Methodology: A retrospective study of 62 consecutive patients who underwent pancreaticoduodenectomy, divided into two groups: 31 patients using fibrin sealant (GCS) and 31 patients without the sealant employment (GSS). The variables were grouped into epidemiological, clinical, laboratory, especially the incidence of pancreatic fistula classified as defined by the International Study Group on Pancreatic Fistula, their postoperative complications cataloged according to Clavien rating and its repercussions on care and its costs assessed by the absorption method with simple apportionment of all expenses except the expenditure on medicines, treated separately. Results: The groups were homogeneous for clinical, epidemiological and laboratory parameters and no significant differences were recorded in the comparison given postoperative progress and hospital assistance indicators. Moreover, hospital costs were higher in GCS, with respect to GSS (p <0.0001). Conclusion: The use of fibrin sealant in pancreatojejunal anastomosis after pancreaticoduodenectomy, in the studied conditions, did not improve the results of care and also increased hospital costs
24

PCB i byggnader : Handlingsplan för saneringsarbetet i Eskilstuna kommun

Zetterman, Eric January 2009 (has links)
<p>Polychlorinated biphenyls, PCBs, were used in elastic sealants in buildings during the years1956-1973. Studies of PCB have revealed that it is harmful for humans and animals,especially water-living predators and other top-predators. It is also a persistent organicpollutant and remains in the environment for a very long time. To reduce the levels of PCB inthe environment, it has to be removed from the buildings. According to Swedish law, theproperty holder has to decontaminate sealants with a PCB level of 500 mg/kg or above. Themunicipalities are the supervising authority and they shall follow up the decontaminations toassure that the PCB has been properly removed from the buildings. The PCBdecontaminationin Eskilstuna municipality has not been a prioritised work, hence, there isPCB left in the buildings which need to be removed. To facilitate the decontamination-work,a plan of action has been developed. This plan will assist the inspector in prioritising thedifferent cases.</p>
25

PCB i byggnader : Handlingsplan för saneringsarbetet i Eskilstuna kommun

Zetterman, Eric January 2009 (has links)
Polychlorinated biphenyls, PCBs, were used in elastic sealants in buildings during the years1956-1973. Studies of PCB have revealed that it is harmful for humans and animals,especially water-living predators and other top-predators. It is also a persistent organicpollutant and remains in the environment for a very long time. To reduce the levels of PCB inthe environment, it has to be removed from the buildings. According to Swedish law, theproperty holder has to decontaminate sealants with a PCB level of 500 mg/kg or above. Themunicipalities are the supervising authority and they shall follow up the decontaminations toassure that the PCB has been properly removed from the buildings. The PCBdecontaminationin Eskilstuna municipality has not been a prioritised work, hence, there isPCB left in the buildings which need to be removed. To facilitate the decontamination-work,a plan of action has been developed. This plan will assist the inspector in prioritising thedifferent cases.
26

Performance Comparison of Large Diameter Residential Drinking Water Wells

Javor, Paul January 2010 (has links)
Published scientific work indicates that residential large diameter drinking water wells are at a higher risk of contamination from surface water impacts than drilled wells. The possibility of a higher incidence of contamination of large diameter wells is attributed to site selection and construction problems such as leaking joints in the well casing, ineffective annular sealant placed between the well casing and the formation, a poorly fitted cover with an access lid that promotes contaminant entry and air entry without adequate air filtration, well location down gradient of septic effluent sources, and depth limitations due to improper equipment used to advance the well which results in shallow wells often situated in topographical lows. In some situations, flaws in the well design were actually deliberate measures intended to capture surface water at sites with low groundwater yield. Historically, residential drinking water well performance studies have focussed on existing wells; however, uncertainty in the actual well construction methods and materials, well age and maintenance efforts have been problematic. A field and laboratory study was completed to assess the performance of several design changes that were thought to improve the integrity of large diameter drinking water wells, and to determine whether one design is more prone to atmospheric and/or surface water contamination than the other. Four large diameter residential wells were installed at a study site in Lindsay, Ontario. Three of these wells are constructed with enhanced construction methods (two using a cement tile casing and one using a galvanized steel casing) and annular sealants, while the fourth was constructed using conventional methods for cement cased wells. The enhanced test wells utilized a sealant between the casing sections, various annular sealants between the formation and the well casing, sanitary waterline connections, and ventilation with air filtration. The well constructed using outdated methods did not have any of these advanced features. An automated water extraction system removed about 875 L/day from each well to mimic residential usage. Routine monitoring, and laboratory and field testing were used to collect pertinent data required for this performance assessment. Routine monitoring involved the visual inspection of the wells, collection of well water elevation, collection of soil temperature profile data, collection and analysis of water samples, and collection of cumulative water volumes purged from the test wells. A biofilm cleaning study and analysis of cement-bentonite grout was conducted in the laboratory while smoke and aqueous tracer tests were conducted in the field. The biofilm cleaning study entailed growing a biofilm on different large diameter well casing materials and applying cleaning methods thought to be practical for cleaning the interior walls of large diameter wells. Different mixtures of cement-bentonite grout were subjected to volume measurements, vertical load bearing capacity analysis, and hydraulic conductivity analysis to determine their suitability as a potential annular sealant. The tracer tests were developed to determine whether pathways for either airborne contaminants or surface water to enter the test wells exist. The test wells were filled with smoke and monitored for potential atmospheric pathways. A tracer solution was infiltrated around the test wells and the interior of the tests wells were monitored for potential pathways for surface water to enter. Bacteriological indicators were detected in all test wells. The smoke tracer tests demonstrated that pathways for airborne contaminants to enter the test wells exist with more pathways observed in the winter than the summer. The aqueous tracer tests highlighted several areas where surface water could enter the test wells if ponding occurred around the well casing. As expected the enhanced test wells performed much better than the conventional test well for both of these tracer tests. The results of the biofilm cleaning study indicated that galvanized steel or fibreglass casing materials were the only materials able to be cleaned effectively. The best method in this study to remove biofilm from casing materials was pressure washing. The results from the cement-bentonite grout investigation indicated that cement-bentonite grout with 5% bentonite would make the most suitable annular sealant as its volume changed the least during curing, it was strong enough to support the load from maintenance efforts, and was the most impervious. The results of this study indicate that large diameter wells constructed with a proper annular sealant, sealant between casing sections and a sanitary waterline connection are less prone to contamination. Monitoring of the test wells should continue as they mature to determine whether this plays a significant role in their ability to prevent contamination of large diameter wells. Smoke tracer tests should be conducted again during the winter to determine if temperature was the cause of increased atmospheric pathways. A field-scale method to remove biofilm from the interior casing wall of large diameter wells should be developed and tested. A field-scale investigation of cement-bentonite grout for use as an annular sealant should be completed. Fibreglass casings can be fabricated as a continuous piece with no seams or joints and hence another well should be constructed and studied using corrugated fibreglass (NSF ANSI 61) casing.
27

Performance Comparison of Large Diameter Residential Drinking Water Wells

Javor, Paul January 2010 (has links)
Published scientific work indicates that residential large diameter drinking water wells are at a higher risk of contamination from surface water impacts than drilled wells. The possibility of a higher incidence of contamination of large diameter wells is attributed to site selection and construction problems such as leaking joints in the well casing, ineffective annular sealant placed between the well casing and the formation, a poorly fitted cover with an access lid that promotes contaminant entry and air entry without adequate air filtration, well location down gradient of septic effluent sources, and depth limitations due to improper equipment used to advance the well which results in shallow wells often situated in topographical lows. In some situations, flaws in the well design were actually deliberate measures intended to capture surface water at sites with low groundwater yield. Historically, residential drinking water well performance studies have focussed on existing wells; however, uncertainty in the actual well construction methods and materials, well age and maintenance efforts have been problematic. A field and laboratory study was completed to assess the performance of several design changes that were thought to improve the integrity of large diameter drinking water wells, and to determine whether one design is more prone to atmospheric and/or surface water contamination than the other. Four large diameter residential wells were installed at a study site in Lindsay, Ontario. Three of these wells are constructed with enhanced construction methods (two using a cement tile casing and one using a galvanized steel casing) and annular sealants, while the fourth was constructed using conventional methods for cement cased wells. The enhanced test wells utilized a sealant between the casing sections, various annular sealants between the formation and the well casing, sanitary waterline connections, and ventilation with air filtration. The well constructed using outdated methods did not have any of these advanced features. An automated water extraction system removed about 875 L/day from each well to mimic residential usage. Routine monitoring, and laboratory and field testing were used to collect pertinent data required for this performance assessment. Routine monitoring involved the visual inspection of the wells, collection of well water elevation, collection of soil temperature profile data, collection and analysis of water samples, and collection of cumulative water volumes purged from the test wells. A biofilm cleaning study and analysis of cement-bentonite grout was conducted in the laboratory while smoke and aqueous tracer tests were conducted in the field. The biofilm cleaning study entailed growing a biofilm on different large diameter well casing materials and applying cleaning methods thought to be practical for cleaning the interior walls of large diameter wells. Different mixtures of cement-bentonite grout were subjected to volume measurements, vertical load bearing capacity analysis, and hydraulic conductivity analysis to determine their suitability as a potential annular sealant. The tracer tests were developed to determine whether pathways for either airborne contaminants or surface water to enter the test wells exist. The test wells were filled with smoke and monitored for potential atmospheric pathways. A tracer solution was infiltrated around the test wells and the interior of the tests wells were monitored for potential pathways for surface water to enter. Bacteriological indicators were detected in all test wells. The smoke tracer tests demonstrated that pathways for airborne contaminants to enter the test wells exist with more pathways observed in the winter than the summer. The aqueous tracer tests highlighted several areas where surface water could enter the test wells if ponding occurred around the well casing. As expected the enhanced test wells performed much better than the conventional test well for both of these tracer tests. The results of the biofilm cleaning study indicated that galvanized steel or fibreglass casing materials were the only materials able to be cleaned effectively. The best method in this study to remove biofilm from casing materials was pressure washing. The results from the cement-bentonite grout investigation indicated that cement-bentonite grout with 5% bentonite would make the most suitable annular sealant as its volume changed the least during curing, it was strong enough to support the load from maintenance efforts, and was the most impervious. The results of this study indicate that large diameter wells constructed with a proper annular sealant, sealant between casing sections and a sanitary waterline connection are less prone to contamination. Monitoring of the test wells should continue as they mature to determine whether this plays a significant role in their ability to prevent contamination of large diameter wells. Smoke tracer tests should be conducted again during the winter to determine if temperature was the cause of increased atmospheric pathways. A field-scale method to remove biofilm from the interior casing wall of large diameter wells should be developed and tested. A field-scale investigation of cement-bentonite grout for use as an annular sealant should be completed. Fibreglass casings can be fabricated as a continuous piece with no seams or joints and hence another well should be constructed and studied using corrugated fibreglass (NSF ANSI 61) casing.
28

Characterization of asbestos exposure among automotive mechanics servicing and handling asbestos-containing materials

Dotson, Gary Scott 01 June 2006 (has links)
The historic use of asbestos-containing materials during the manufacturing of automobiles has resulted in a perception of an increased risk of asbestos-related pulmonary diseases within mechanics. This study was conducted to assess the potential asbestos exposures mechanics encounter while servicing vehicles assembled with parts containing asbestos, in addition to compare the cumulative lifetime asbestos exposures for different maintenance activities against theorical threshold exposures for asbestosis, lung cancer and mesothelioma. Exposure data were assembled from four independent exposure assessments performed to elucidate the airborne asbestos levels generated during the removal and replacement of brakes, gaskets, clutches and seam sealants containing asbestos. The phase contrast microscopy (PCM) and phase contrast microscopy equivalent (PCME) fiber concentrations for personal samples and air sampled identified to contain asbestos fibers through Transmission Electron Microscopy (TEM) analysis were applied to calculate the cumulative lifetime asbestos exposures. This index of exposure was compared to no-effect exposure thresholds identified through an extensive literature review for the selected pulmonary diseases. The results of this study indicate that mechanics encounter PCM fiber concentrations approximately 10 to 100 times lower than the current Occupational Safety Health Administration (OSHA) Permissible Limit Exposure (PEL) of 0.1 fibers per cubic centimeter (f/cc). Additionally, the cumulative lifetime asbestos exposures ranged from <1 fiber-year/cubic centimeter of air (f-yr/cc) to 2.0 f-yr/cc, and did not exceed the no-effect exposure thresholds for asbestosis, lung cancer and mesothelioma. The findings of this study provide additional support to previously published epidemiologic investigations and exposure assessments against an increased risk of asbestos-related disease within mechanics historically employed to service vehicles containing asbestos fibers.
29

The development of a frameless glass door made for wheel loaders

Hult, Josefin January 2014 (has links)
This thesis performed on master level covers an assignment given by the cab division at Volvo Construction Equipment (Eskilstuna, Sweden). The thesis has been carried out by Josefin Hult during the period 2014-01-23 to 2014-05-30 at Mälardalen University. Volvo Construction Equipment manufactures products including wheel loaders, backhoe loaders and articulated haulers. The assignment involves developing the standard door for larger wheel loaders. The current door has a welded frame surrounding the glass that is considered outdated and not cost effective. Volvo Construction Equipment wishes that the door was made in glass in a greater extent. The aim of the assignment has been to generate concepts regarding a glass door that fulfills given requirements. Three research questions have been stated and answered during the process. The product development process has consisted of three phases: information gathering, concept development process and development of detailed concept. For example, field studies and benchmarking have been performed to gather information about competitors’ products and the manufacturing and assembling of the current door. Concepts for handrails, sealant and overall door design have been generated in an iterative process. All components of the door have been developed into a detailed concept during the last phase of the process. The process has resulted in a frameless glass door. The concept suggestion consists of; a tempered sheet of glass, a clip list (sealant) that covers the edges of the glass, two different handrails, inner and outer handles, a gas spring, components to attach handrails against the glass, a cover and a lock mechanism. The major conclusion that is drawn is that it is fully possible to develop a door made in glass in a greater extent than the current door. Many competitors have machines where the door is made in glass in a large extent. This makes it believable that the glass door also will be perceived as timely and more modern and clear. Recommendations have been developed if there is interest in further development. The recommendations include, among others, development of handrail and test of prototype to ensure that all requirements are fulfilled. Figures are produced by the author if not stated otherwise.
30

Cola de fibrina canina produzida com fibrinogênio obtido por crioprecipitação e precipitação com protamina a partir de diferentes categorias de plasma pobre em plaquetas / Canine fibrin glue produced with fibrinogen concentrated from cryo- and protamine precipitation using different platelet poor plasma categories

Gonçalves, Monalyza Cadori January 2015 (has links)
A cola de fibrina tem sido utilizada em diferentes procedimentos cirúrgicos como agente hemostático, selante e de suporte adesivo. No entanto, seu emprego na Veterinária ainda é limitado devido à falta de formulações não dependentes dos componentes de origem humana e de validação baseada em necessidades e condições cirúrgicas de animais. Objetivou-se avaliar a viabilidade da produção de cola de fibrina canina com fibrinogênio obtido por crioprecipitação (crio) e precipitação por protamina a partir de fontes plasmáticas mais disponíveis em bancos de sangue e centros hospitalares. Quatro categorias de plasma pobre em plaquetas foram utilizadas: plasma fresco (FR), congelado dentro de oito horas da colheita e processado em menos de uma semana após congelamento; plasma fresco congelado (FFP), com armazenamento inferior a um ano; plasma fresco congelado que ultrapassou um ano de armazenamento (eFFP), e plasma congelado com período entre colheita e congelamento maior que oito horas e de armazenamento superior a um ano (FP). No estudo in vitro de cada técnica, avaliou-se a concentração de fibrinogênio precipitado por meio do método de Clauss, as propriedades reológicas do gel por tromboelastografia (TEG) e as características estruturais do coágulo por microscopia eletrônica de varredura (SEM). O estudo in vivo consistiu da avaliação da praticidade de aplicação e das propriedades hemostáticas e adesivas das colas de fibrina resultantes em fígado e intestino de coelho (Oryctolagus cuniculus). Em avaliação prévia do protocolo de crio quanto ao uso de bolsas ou tubos, o aproveitamento do material inicial não diferiu, mas os tubos se mostraram mais simples, rápidos e homogêneos para o processamento, além de permitirem aumento da concentração final. O protocolo crio em comparação ao de protamina foi superior na precipitação de fibrinogênio coagulável nas avaliações de Clauss e TEG. Os coágulos formados se mostraram semelhantes entre os dois protocolos na SEM, no modelo de hemostasia hepática e na adesão à serosa intestinal. O uso de aprotinina com o protocolo de protamina não prejudicou a aplicação da cola sobre o intestino. Na crio, plasmas com maior tempo de armazenamento (eFFP, FP) se mostraram significativamente superiores aos mais frescos (FFP, FR) nas análises por Clauss e TEG. Não foi possível identificar diferenças estatísticas entre os tipos de plasma no protocolo protamina em nenhum dos parâmetros avaliados. Estudos adicionais e ajustes nos testes para avaliação de soluções concentradas são necessários para determinação do efeito dos protocolos e tempo de armazenamento do plasma congelado sobre o fibrinogênio precipitado e demais componentes plasmáticos na cola de fibrina. Adequações e pesquisas ainda são necessárias para aproveitamento da precipitação de fibrinogênio por protamina e a partir de plasma fresco com a finalidade de obtenção rápida de cola de fibrina. Bolsas de plasma menos requisitadas em bancos de sangue veterinários representam uma fonte importante de fibrinogênio para a produção de cola de fibrina canina em centros hospitalares apropriadamente equipados, viabilizando seu uso em diferentes aplicações cirúrgicas e pesquisas relacionadas. / Fibrin glue (FG) has been widely used in surgery for hemostatic, adhesive, sealant, and would healing support. In veterinary surgery, however, its use has been hindered by lack of specie-specific formulations and validation of its properties and biological characteristics. This study evaluated methods of fibrinogen precipitation from canine plasma envisioning autologous and allogeneic FG production for surgical use. The efficacy of cryo and protamine fibrinogen precipitation methods in producing canine FG was assessed by analysis on feasibility of each protocol with most available canine plasma sources, rheological and structural characteristics of the resultant FG clot and the hemostatic and adhesive properties of FG during in vivo application. The plasma categories studied included fresh plasma (FR), obtained and frozen within 8 hours from blood collection and processed within a week; fresh frozen plasma (FFP), frozen within 8 hours from blood collection and stored for up to a year; expired fresh frozen plasma (eFFP), plasma frozen within 8 hours from blood collection but stored for more than a year; and, frozen plasma (FP), which was frozen after 8 hours from collection and stored for more than a year. Comparison of cryoprecipitation among plasma types was previously performed in both 120-mL bags and 50-mL tubes and analyzed by Clauss. Total precipitation capacity did not differ significantly between bags and tubes. Nevertheless, the processing was more easily and homogeneously performed in tubes and allowed tailoring the final concentration. Cryoprecipitation generated better results in Clauss and TEG in comparison to protamine protocol. The resultant fibrin glue clots of cryo- and protamine-precipitation showed similar ultrastructure in scanning electron microscopy (SEM) and performance in the in vivo evaluations with the rabbit hepatic and intestinal incision models. The use of aprotinin in the protamine clot seemed beneficial in the intestinal evaluation. With cryoprecipitation, eFFP and FP were superior to FFP in the assessments performed by Clauss and TEG. Fresh plasma performed poorly with cryoprecipitation. Significant differences were not detected among plasma categories processed with protamine precipitation in any of the assays performed. While cryoprecipitation was more reliable regarding homogeneity and capacity to increase final fibrinogen concentration, protamine protocol was faster and simpler considering the equipment required. Although, older plasma units generated significantly more cryoprecipitated and/or clottable fibrinogen, further studies are needed to validate the assays with such high concentrated solutions and to elucidate the effect of freezing storage on precipitation and clottability of fibrinogen intended for FG production. Adjustments on protamine protocol and improvements on fibrinogen precipitation from fresher plasma sources would support the use of autologous or allogeneic plasma for on-site production of canine FG. Veterinary hospitals, blood banks, and patients can benefit from usage of surplus plasma units for FG production aiming surgical and scientific needs.

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