No description available.

This thesis deals with the design process of a tensile test specimen geometry with the intention that the specimen will show failure in a shear band during a tensile test. The triggered shear band is linked to a characteristic length lc, which is required for a nonlocal approach to continuum damage mechanics that predicts the life expectancy of a combustion chamber independent of the FEM mesh size. To predict if a specimen will fail in the preferred manner, numerical simulations have been performed and were analysed with the newly defined failure-in-shear-band indicator. Ductile failure modes and the fracture process depend strongly on the stress state. Therefore the indicator is formulated as a function of the Lode parameter and the stress triaxiality. Several double-notched bar specimens have been designed with different notch radii and notch depths. The failure-in-shear-band indicator implies promising values for a small notch radius and larger notch depth. Tensile tests were performed on four specimens which successfully failed in a shear band. Furthermore, a first statement on the magnitude of the characteristic length of CuAgZr is given. / Detta arbete behandlar designprocessen för en dragprovstavskonfiguration framtagen för att uppvisa brott i ett skjuvband under draghållfasthetsprovning. Initiering av skjuvbandet är kopplat till en karakteristisk längd lc, som krävs för att kunna använda en icke lokal metod för att analysera kontinuerlig skademekanik oberoende av maskstorleken i den numeriska modellen. Metoden är utvecklad för att kunna uppskatta den förväntade livslängden för en förbränningskammare. För att förutsäga om ett provobjekt kommer att gå sönder på det sätt som önskashar datorsimuleringar utförts och analyserats med den nyligen definierade indikatorn för skjuvbrott. Plastisk deformation, och så småningom brott, är starkt beroende avspänningstillståndet. Indikatorn är därför formulerad som en funktion av en s.k. Lode parametern och det treaxliga spänningstillståndet. Flera provstavsgeometrier har utformats med dubbla brottanvisningar vars radie och storlek varierats. Indikatorn för skjuvbrott ger lovande värden för små radier och ett större anvisningsdjup. Draghållfasthetsprovning utfördes på fyra provkroppar som uppvisade önskat skjuvbrott. Dessutom erhölls en första indikation om storleken på den karakteristiska längden för CuAgZr.

Passive loading of a specimen is a relatively cheap method to use in fracture mechanical testing compared to an actively loaded specimen. For stress corrosion cracking testing it is easier to use a passively loaded specimen since the specimen easily can be placed in a specific corrosive environment. The passive method lacks information about the crack growth over time and the load can not be regulated during the test to ensure crack growth. This thesis work was mainly about finding a specimen with a region of constant KI to ensure crack growth without the need of controlling the load and to find a way to estimate the crack growth over time. The work is based on Linear Elastic Fracture Mechanics and the Finite Element Method. The thesis work resulted in a specimen with constant KI in the region 23/50 ≤ a/W ≤ 33/50 of crack growth and an equation was found to describe the relation between the crack propagation and the strain measured on the specimens back face. / Passiv belastning av en provstav är en relativt billig metod att använda för brottmekanisk provning jämfört med en aktivt belastad provstav. En passivt belastad provstav är enklare att använda vid provning av spänningskorrosion då provstaven enkelt kan placeras i en specifik korrosiv miljö. Den passiva metoden är bristande i information om spricktillväxen över tid och belastningen på provstaven kan inte justeras för att upprätthålla fortsatt spricktillväxt under provningens gång. Detta examensarbete syftade till att ta fram en provstav med ett spricktillväxtomrade med konstant KI för fortsatt spricktillväxt vid konstant belastning samt att hitta en metod för att uppskatta spricktillväxten över tid. Arbetet är baserat på linjärelastisk brottmekanik och finita elementmetoden. Arbetet resulterade i en provstav med konstant KI i spricktillväxtområdet 23/50 ≤ a/W ≤ 33/50 och en relation mellan spricktillväxt och töjningen som mäts på provstavens baksida.

Environmentally-assisted cracking (EAC) phenomena affect the in-service behaviour of austenitic stainless steels in nuclear power plants. EAC includes such degradation phenomena as Stress Corrosion Cracking (SCC) and Corrosion Fatigue (CF). Factors affecting EAC include the material type, microstructure, environment, and stress. This is an important degradation issue for both current and Gen III+ light water reactors, particularly as nuclear power plant lifetimes are extended ( > 60 years). Thus, it is important to understand the behaviour of the alloys used in light water reactors, and phenomena such as SCC to avoid failures. Although there is no agreement on the mechanism(s) of SCC, the importance of localized electrochemical reactions at the material surface is widely recognised. Considerable research has been performed on SCC and CF crack growth, but the initiation phenomena are not fully understood. In this project, novel in situ analytical TEM techniques have been developed and applied to explore localised reactions in Type 304 austenitic stainless steel. In situ transmission electron microscopy has become an increasingly important and dynamic research area in materials science with the advent of unique microscope platforms and a range of specialized in situ specimen holders. In metals research, the ability to image and perform X-ray energy dispersive spectroscopy (XED) analyses of metals in liquids are particularly important for detailed study of the metal-environment interactions with specific microstructural features. To further facilitate such studies a special hybrid specimen preparation technique involving electropolishing and FIB extraction has been developed in this thesis to enable metal specimens to be examined in the liquid cell TEM specimen holder using both distilled H2O and H2SO4 solutions. Furthermore, a novel electrode configuration has been designed to permit the localized electrochemical measurement of electron-transparent specimens in the TEM. These novel approaches have been benchmarked by extensive ex situ experiments, including both conventional electrochemical measurements and microcell measurements. The results are discussed in terms of validation of in situ test data as well as the role of the electron beam in the experiments. In situ liquid cell TEM experiments have also explored the localized dissolution of MnS inclusions in H2O, and correlated the behaviour with ex situ experiments. Based on the research performed in this thesis, in situ liquid cell and in situ electrochemical cell experiments can be used to study nanoscale reactions pertaining to corrosion and localized dissolution leading to "precursor" events for subsequent EAC phenomena.

Tato závěrečná práce je shrnutím výzkumu smykově zatěžovaných trhlin, který proběhl v průběhu čtyř let doktorského studia jejich autora Ing. Stanislava Žáka (Středoevropský technologický institut, Vysoké učení technické v Brně). Předložená práce je zaměřena na prohloubení znalostí v oblasti pokročilé lomové mechaniky, konkrétně pro smykové zatěžování trhlin kombinované s případy geometrických odchylek trhlin od běžně používaných modelů. To mimo jiné znamená návrh nových přístupů a modelů a popis součinitelů intenzity napětí pro geometricky komplikované trhliny. První část práce je věnována shrnutí současných přístupů v lomové mechanice a dále i popisu numerických metod, použitých v dalších výpočtech. Kromě klasických přístupů se tato část textu zabývá i novějším výzkumem zaměřeným na smykové zatěžování trhlin, speciálně pro dva typy zkušebních těles – válcový vzorek s obvodovým vrubem a trhlinou zatížený prostým smykem nebo krutem a CTS těleso umožňující zatížení trhliny v módech I, II a také v jejich kombinaci I+II. Další část textu je zaměřena na konkrétní výpočty lomových parametrů při použití nových modelů s komplikovaným čelem trhliny. Teoretické řešení lomových parametrů pro oba výše zmíněné modely je porovnáno s experimentálními výsledky, získanými v navazujících projektech. U modelu válcového vzorku je popsána možnost zjednodušení budoucích modelů těles s podobným typem komplikované trhliny a současně je na něm popsán lokální vliv zubatosti čela trhliny na indukci lokálního zatížení v módu II při globálním zatížení v módu III. Tyto výsledky jsou přímo propojeny s experimentální kvantifikací únavového šíření lomu při zatížení v módu III. CTS těleso je použito k popisu vlivu drsnosti trhliny na součinitele intenzity napětí. Na tomto modelu je pozorován jak globální pokles hodnoty KII při zvyšující se drsnosti trhliny, tak i lokální změny v namáhání trhliny podél jednotlivých nerovností. Výsledky potvrzují, i pro dosud málo zkoumané smykové zatěžování, že mikrostruktura lomových ploch a čela trhliny má vliv na lomové parametry. Rozšiřují tak současné znalosti v oboru lomové mechaniky popisem geometrického stínění čela trhliny pro zátěžné módy II a III.

No description available.

Background Patient safety is an undisputable part of healthcare. The use of clinical practice guidelines, usually based on evidence-based practice/best practice, promotes patient safety and high quality care, reduces unnecessary patient suffering, and healthcare costs. Analysing results from venous blood specimen collection is one of the most commonly used services within healthcare, and a substantial number of decisions on diagnosis, treatment, and treatment evaluation are based on the results. Hence, the accuracy of these tests are vitally important. Earlier research has demonstrated that healthcare staff report suboptimal adherence to venous blood specimen collection guidelines together with the need for improved practices. Blood sample collection is carried out by several professionals, among them registered nurses and, as a consequence, nursing students too. University nursing students learn and practice venous blood specimen collection in one of their first semesters. After initial skill training at clinical skill laboratories, they continue to perform the task during clinical placements in various clinical settings. Few or no studies have been performed on nursing students, hence it seemed important to assess guideline adherence to venous blood specimen collection among university students as well as to further explore adherence to guidelines among healthcare staff. Therefore, the overall aim for this thesis was to explore adherence to, and factors influencing venous blood specimen collection guidelines practice among university nursing students and healthcare staff. Methods The thesis includes four studies. Study I-III had a quantitative, cross-sectional design, study IV had a qualitative approach. Study I included 164 healthcare staff from 25 primary healthcare centres. Study II included 101 nursing students in their 5th and 6th semesters, and study III included 305 nursing students in their 2nd, 4th, and 6th semesters. To assess adherence to venous blood specimen collection guidelines, data were collected using the Venous Blood Specimen Questionnaire, completed with background variables (I, II, III) and additional scales (III). Descriptive statistics, multilevel and multiple logistic regression analyses were used to analyse the data. In study IV, data were collected through five focus group interviews among 6th semester nursing students (n=26). Data were analysed using qualitative content analysis. Results Workplace affiliation was found to explain variances in reported adherence between different primary healthcare centres. Associations between reported venous blood specimen collection practices and individual as well as workplace factors were revealed. Nursing students were found to increasingly deviate from guideline adherence during their education. Also among students, several associations between guideline adherence and other iv factors were revealed. Reported research use at clinical practice was associated with higher levels of adherence, as were higher capability beliefs regarding both evidence-based practice and academic ability. Analyses from focus group interviews summarised students’ reflections on deviations from VBSC guidelines in the overall theme ‘Striving to blend in and simultaneously follow guidelines’. Conclusion Both healthcare staff at primary healthcare centres and nursing students demonstrate decreasing levels of guideline adherence with time. Factors influencing adherence are both individual as well as contextual. This indicate that both students and staff are subjected to socialisation processes that influences levels of adherence. In order to enhance venous blood specimen collection practices and thereby patient safety, actions must be taken - both in healthcare clinical contexts and by educators. The use of models in practical skill training, and in the ambition to bridge the theory-practice gap may be the path to success. It is reasonable to assume that collaboration between, on the one hand, education representatives and on the other, supervising RNs in clinical settings, will be fruitful. Finally, by empowering students their self-efficacy may be strengthened, and hence their ability to maintain guideline adherence.

The subject of my thesis is the regulation of international trade in endangered species. An excessive trade in endangered species is one of the main causes of biodiversity loss on the Earth. The biodiversity loss constitutes a serious worldwide problem and threatens the stability of all the ecosystems. It is becoming more urgent by the fact that the speed of species extinction or at least their inclusion in the lists of endangered species is getting faster. Especially an illegal trade in endangered species is considered one of the largest and the most profitable. I have chosen this topic with the aim to show legal methods and ways of the regulation of the excessive exploitation of wildlife. The question of the regulation of the international trade is examined from the international perspective, the perspective of the European Union law and as well from the czech law perspective. A considerable stress is put on the description and explanation of the operation of the international trade regulation system regarding that an effective slowdown of the biodiversity loss phenomenon or its stop can be only possible by the international cooperation of the countries. The remaining levels of the regulation must be in compliance with the international level of the regulation. The thesis is consisted of six...

Introdução: O Estudo Longitudinal de Saúde do Adulto é um estudo de coorte multicêntrico com o objetivo de identificar os fatores de risco associados ao diabetes tipo 2 e à doença cardiovascular na população brasileira. Nosso principal objetivo é explicar a concepção e implementação das rotinas do laboratório central e biobanco do Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil); destacando as forças e limitações do protocolo. O segundo objetivo é descrever os pré-testes usados para validar o protocolo de antes do início do estudo. Métodos: O estudo optou pela centralização dos exames em um laboratório central no Hospital Universitário da Universidade de São Paulo (USP), Com base em dados recentes que confirma a estabilidade da glicose em amostras congeladas, até os testes de glicose no sangue foram centralizadas. Porém o processamento das amostras foi realizado nos laboratórios locais o que reduziu os custos do transporte das amostras para o laboratório central. A estratégia implicou na necessidade de implementação de equipes nos laboratórios em cada Centro de Investigação para coletar e processar as amostras antes do transporte. O estudo incluiu exames para a avaliação do metabolismo da glicose, resistência à insulina, perfil lipídico, eletrólitos, ácido úrico, hormônios da tireóide, função hepática e contagem total de células do sangue. Além disso, as amostras de DNA, urina plasma, e de soro foram colhidas e Além desses exames, o estudo também extraiu DNA de leucócitos, colheu e estocou amostras de urina, plasma e soro. Para garantir a homogeneidade do protocolo todos os membros das equipes locais passaram por treinamento e certificação centralizado, com visitas cruzadas entre os centros durante o campo para controle de qualidade. Resultados: A opção por um laboratório central garantiu a uniformidade da metodologia utilizada para a realização dos exames, evitando as variações inevitáveis entre laboratórios. Durante 26 meses, cerca de 375.000 testes foram realizados no laboratório central. Não houve perda de amostras biológicas durante o estudo. A implementação do biobanco usando palhetas armazenados em repositórios de nitrogênio foi realizada sem problemas importantes desde 2008 até agora. Conclusão: O ELSA-Brasil mostrou a exequibilidade de exames multicêntricos no Brasil com todos os exames realizados em um laboratório central, de uma maneira custo-efetiva. A logística de armazenamento de amostras biológicas foi feito com custos aceitáveis e de qualidade, sendo um modelo para estudos futuros / Background: The Longitudinal Study of Adult Health is a multicenter cohort study aimed to identify risk factors associated with type 2 diabetes and cardiovascular disease in Brazilian population. Our main objective is to explain the conception and implementation of the routines of the central laboratory and biobank of the Longitudinal Study of Adult Health (ELSA-Brasil) highlighting the strength and the limitations of the protocol The second objective is to describe the pre-tests used to validate the protocol before the start of the study. Methods: The study made an option to centralize the exams in one central laboratory at the University Hospital, São Paulo University (\"USP\"). Based on recent data that confirms the stability of glucose in freeze samples, even blood glucose tests were centralized. However, biological samples were processed in the local laboratories, reducing the weight of the material to be transported, and diminishing costs of transportation to the central lab. Especially trained local teams collected and processed biological samples before transportation. The study included tests for glucose metabolism, insulin resistance, lipid profile, electrolytes, uric acid, thyroid hormones, hepatic function, and total blood cell count. In addition, DNA, urine, plasma and serum samples were collected and stored. In order to guarantee protocol homogeneity, all team members underwent centralized training and certification, and cross-visits in each research center were done. Results: The choice of a central laboratory assured uniformity of the methodology used for the exams, avoiding the variations between laboratories During 26 months, approximately 375,000 tests were done in the central- laboratory. There was no loss of biological samples during the study. The implementation of the biobank using straws stored in nitrogen repositories was performed without important problems since 2008 until now. Conclusion: The ELSA-Brazil showed the feasibility of a multicenter study in Brazil with all the analyses performed in a central laboratory, in a cost-effective way. The logistic of storage of biological samples was done with acceptable costs and quality being a model for future studies

A punção venosa periférica é a inserção de dispositivos por veia periférica para acesso à corrente sanguínea, como na coleta de sangue para exames; embora seja um procedimento comum no tratamento intra-hospitalar, é complexo e exige competência profissional. A realização desse procedimento de forma inadequada pode colocar em risco a saúde do paciente, podendo provocar diversas complicações ao seu tratamento. A pesquisa teve como objetivo desenvolver e validar a primeira versão de um simulador de realidade virtual (RV) imersiva para o procedimento de punção venosa periférica para coleta de sangue a vácuo no paciente adulto. Revisão integrativa da literatura permitiu verificar as estratégias de ensino de punção venosa periférica na enfermagem. Procedeu-se, em seguida, um estudo com delineamento metodológico para desenvolver e validar a primeira versão do simulador. O uso de recursos tecnológicos como estratégias de ensino em enfermagem está em expansão, porém a simulação com RV, principalmente no ensino de punção venosa periférica, ainda é um vasto campo a ser explorado. Foi desenvolvida a primeira versão de um simulador de RV para a coleta de sangue à vácuo no adulto - o VIDA-Enfermagem v1.0, o qual foi avaliado por profissionais e graduandos de enfermagem. Foram considerados válidos 79,6% dos itens avaliados pelos profissionais e 66,7% dos itens avaliados pelos graduandos. As sugestões propostas pelos sujeitos da pesquisa para melhorias do sistema, em sua maioria, são passíveis de aceitação no decorrer do incremento das versões seguintes. Mesmo havendo necessidade de revisão de diversos itens, na avaliação dos participantes, o simulador foi considerado uma ferramenta promissora e inovadora para o ensino do procedimento de punção venosa periférica para coleta de sangue a vácuo em paciente adulto, para graduandos de enfermagem que estão se iniciando no estudo da temática e da técnica, como estratégia a ser combinada com os recursos já utilizados atualmente no ensino do procedimento. É relevante que se invista em estratégias inovadoras e motivadoras para aplicação no ensino de enfermagem, principalmente com o uso da realidade virtual imersiva / Peripheral venipuncture is the insertion of a peripheral venous device to access bloodstream, such as in blood collection for tests; although it is a common procedure in in-hospital treatment, it is complex and requires professional competence. Failure to perform this procedure may put the patient\'s health at risk, and may cause several complications to his/her treatment. This study aimed to develop and validate the first version of an immersive virtual reality (VR) simulator for the peripheral venipuncture procedure for vacuum blood collection in adult patient. Teaching strategies of peripheral venipuncture in nursing were verified through an integrative literature review. Then, a study with a methodological design was performed to develop and validate the first version of the simulator. The use of technological resources such as teaching strategies in nursing is expanding; however, the simulation with VR, mainly in the teaching of peripheral venipuncture, is still a vast field to be explored. The first version of a VR simulator for vacuum blood collection in adult patient was developed - VIDA-Enfermagem v1.0, which was evaluated by professionals and undergraduate nursing students. 79.6% of the items evaluated by the professionals and 66.7% of the items evaluated by the undergraduate students were considered valid. The suggestions proposed by the research subjects for system improvements, for the most part, may be included in the following versions. Although it was necessary to review several items, in the evaluation of the participants, the simulator was considered a promising and innovative tool for the teaching of the peripheral venipuncture procedure for vacuum blood collection in adult patients, for nursing undergraduate students who are beginning the study of the subject and technique, as a strategy to be combined with the resources already used in the teaching of the procedure. It is relevant to invest in innovative and motivating strategies for application in nursing teaching, especially with the use of immersive virtual reality