We examine the moderating role of the situational and organizational contexts in determining unethical managerial behavior, applying the case-survey methodology. On the basis of a holistic, multiple-antecedent perspective, we hypothesize that two key constructs, moral intensity and situational strength, help explain contextual moderating effects on relationships between managers'; individual characteristics and unethical behavior. Based on a quantitative analysis of 52 case studies describing occurrences of real-life unethical conduct, we find empirical support for the hypothesized contextual moderating effects of moral intensity and situational strength. By examining these complex contextual moderators, we aim to contribute to organizational ethics research as we shed light on the critical role that context may play in influencing unethical managerial behavior.

Conhecer e compreender o funcionamento das variáveis que influenciam e incentivam as empresas a buscarem o desenvolvimento de relações cooperativas interorganizacionais e, além disso, identificar os diferentes níveis de intensidade da interdependência existente atualmente nas relações das empresas moveleiras da serra gaúcha, tanto as relações verticais quanto as horizontais, é o desafio que se pretende alcançar com o presente estudo. Para abordar o referido tema, esta investigação utilizou-se de conceitos fundamentais que norteiam as dimensões desta visão, que são: os relacionamentos cooperativos interorganizacionais, a intensidade da interdependência nas relações, os tipos de relacionamentos, a forma de atuação das empresas e a gestão de relacionamentos. Para reconhecer qual a posição das empresas moveleiras no cenário de relacionamentos interorganizacionais, foi realizada uma pesquisa na qual foi obtida uma amostra de 255 casos válidos em um universo composto por 746 empresas, das quais 93,0% foram enquadradas como MEs (microempresas) e EPPs (empresas de pequeno porte). O uso de ferramentas de análise estatística possibilitou constatar que as fabricantes moveleiras da região da serra gaúcha apresentaram níveis de concordância maiores para as questões que avaliam a preferência pelas relações verticais (clientes e fornecedores), enquanto que as questões que avaliam as relações horizontais (fabricante – fabricante) não apresentaram igual intensidade de preferência. O alcance de vantagens através de ações conjuntas que visem o desenvolvimento comercial das empresas também teve preferência na comparação com as questões que avaliam a possibilidade de obtenção de benefícios através do trabalho conjunto para desenvolvimento de novas tecnologias, para treinamento profissional conjunto, para projetos de melhoria de processos ou para terceirização de fases do processo produtivo. A questão que investiga se os empresários entendem que suas empresas têm alta concentração de vendas em poucos clientes obteve alto grau de concordância, enquanto que, com relação aos fornecedores existe uma interdependência maior com relação aos fornecedores de chapas, ferragens e prestadores de serviços terceirizados. No tocante ao trabalho das associações empresariais os empresários consideram fundamental a divulgação de dados sobre a evolução do setor e o trabalho de lobby político. / Knowing and understanding the functioning of the variables that influence and encourage companies to pursue the development of cooperative interorganizational relationships and, in addition, identifying different levels of intensity of the interdependence of current relationships of the Serra Gaucha’s furniture companies, both vertical and horizontal relations, is the challenge to be achieved with the present study. To address the reported issue, this research made use of fundamental concepts that govern the dimensions of this vision, which are: cooperative interorganizational relationships, the intensity of interdependence in relationships, the types of relationships and the way companies operate and manage relationships . To recognize which were the positions of the furniture companies in the scenario of interorganizational relationships, we conducted a survey in which we obtained a sample of 255 valid cases in a universe composed of 746 companies, of which 93.0% were classified as MEs and EPPs. The use of statistical analysis tools showed that furniture industries in the Serra Gaucha region showed higher levels of agreement to questions that evaluate the preference for vertical relationships (customers and suppliers), while questions that assess horizontal relationships (manufacturer - manufacturer) did not show equal intensity of preference. The range of benefits through joint actions which aim the commercial development of the companies also had preference in comparison to questions that evaluated the possibility of obtaining benefits from cooperative work to develop new technologies, for professional cooperative training, for projects of process improvement or outsourcing phases of the production process. The question that investigates whether entrepreneurs understand that their companies have a high concentration of sales in a few customers obtained a high degree of agreement, while regarding the suppliers there is a greater interdependence related to suppliers of plates, ironwork and outsourced service providers. Concerning the work of entrepreneurs’ associations, they considered essential the dissemination of the data on industry evolution and political lobbying.

Diversificação e rotação de culturas aliado ao cultivo sem revolvimento do solo com inserção de produção animal é uma alternativa desejável aos sistemas de produção em monocultivos intensivos. Neste sentido, o Sistema Integrado de Produção Agropecuária representa uma forma particular de produção de alimentos de forma sustentável. No entanto, a produção animal na fase pastagem adiciona mais complexidade ao sistema e requer um adequado manejo. Nesse contexto, o presente estudo buscou explorar as relações planta-animal da fase pastagem de um Sistema Integrado de Produção Agropecuária no Sul do Brasil. O protocolo experimental foi estabelecido no ano de 2003 e é caracterizado por uma integração entre a fase lavoura, com soja (Glycine max. (L.) Merr.) e milho (Zea mays L.) em rotação, com a fase pastagem, onde são manejados cordeiros em azevém anual (Lolium multiflorum Lam.). Na fase pastagem são testadas combinações de métodos de pastoreio (contínuo e rotativo) e intensidades de pastejo (2,5 e 5 vezes o potencial de consumo de matéria seca). Os maiores ganhos médios diários foram encontrados no método de pastoreio contínuo (MP-C) e intensidade de pastejo 5 (IP-5) (0,135 kg versus 0,120 comparando IP-5 X IP-2,5 no MP-C e 0,115 versus 0,105 no método de pastoreio rotativo (MP-R) nas mesmas intensidades respectivamente). No entanto, o método de pastoreio não teve efeito no ganho de peso vivo por hectare e a intensidade de pastoreio 5 resultou em menor desempenho por área (307 kg versus 387comparando IP-5 versus IP-2,5). A base de dados também foi analisada pela construção de árvores da decisão para relacionar as variáveis do pasto com os desempenhos. Foram construídas árvores da decisão para: i) ganho de peso vivo por hectare: com coeficiente de determinação (R2) = 0,738 sendo a oferta de forragem e produção total de forragem as principais variáveis para os maiores desempenhos; ii) ganho médio diário: com R² = 0,547 foi observado altura do pasto como o fator de maior influência. Assim, dependendo dos objetivos, se é aumentar o desempenho individual ou por área, isto implica em diferentes estratégias de combinações de manejo do dossel. Os resultados deste estudo demonstram a oportunidade potencial oferecida pela produção animal em sistemas integrados para diversificar o uso da terra e ainda promover maior eficiência de produção. / Crop diversification integrated with no till and with livestock production can be a desirable alternative to intensive monoculture production systems. In this way, Integrated Crop-Livestock System plays and unique form of food production sustainable. However, livestock in a pasture phase add more complexity to the system that requires proper pasture management. In this context, the present study aimed to explore plant-animal relationships of the pasture phase in an Integrated Crop-Livestock System in southern Brazil. The experimental protocol was established in the year of 2003 and is composed by the integration of a crop phase, with soybean (Glycine max. (L.) Merr.) and maize (Zea mays L.) in rotation with a pasture phase, when lambs were managed in Italian ryegrass (Lolium multiflorum Lam.). In the pasture phase was tested combinations of stocking methods (continuous and rotational) and grazing intensities (2.5 and 5 times the potential daily dry matter intake). The results showed that higher average daily gain is found in stocking method continuous (SM-C) and in grazing intensity 5 (GI 5) (0.135 g versus 0.120 comparing GI-5 X GI-2.5 in SM-C and 0.115 versus 0.105 in stocking method rotational (SM-R)). However, stocking method had no effect on live weight gain per hectare and grazing intensity 5.0 resulted lower performance by area (307 kg versus 387 comparing GI-5 versus GI-2,5). The data was also analyzed by the decision trees built in order to relate the variables of sward with animal performance. Decision tree were built for: i) live weight gain per hectare: had a Coefficient of Determination (R2) of 0.738, where herbage allowance and total herbage production were found as the main variables influencing the higher animal performance; ii) average daily gain: with R2 = 0.547 was observed that sward height was the most significant factor influencing. Thereby, depending of the goals, if it´s improve individual response or production per area, it implies in different combinations of sward management strategies. The results of this study support the potential opportunity offered by animal production in Integrated Crop-Livestock System to diversify land use while promoting greater production efficiency.

Os níveis de obesidade vêm aumentando, no Brasil e no mundo, de maneira exponencial. A condição de excesso de tecido adiposo pode gerar um prejuízo funcional, bem como alterações em uma série de parâmetros de saúde cardiovascular. A quantidade e qualidade muscular apresentada por um indivíduo obeso podem ser determinantes na maneira como o organismo lida com esses desafios. Dessa forma, o objetivo do presente estudo foi verificar a existência de associação entre variáveis de força, qualidade e quantidade muscular, funcionalidade, saúde vascular e adiposidade em indivíduos obesos. Para isso, trinta e quatro indivíduos obesos, com idade entre 20-60 anos, sedentários, não fumantes e não diabéticos, se voluntariaram a participar do estudo. Após prévia familiarização, foram realizados testes de força nos extensores de joelho (contração isométrica voluntária máxima - CIVM ; 1 repetição máxima - 1RM; potência média) e funcionalidade (teste de caminhada de 6 minutos - TC6M; sentar e levantar em 30 segundos - SL30; get up and go). A massa muscular (EMQUA) e echo intensity do quadríceps femoral (EIQUA) foram medidas por ultrassonografia, bem como diferentes parâmetros de adiposidade e função endotelial (avaliada por dilatação mediada por fluxo - DMF). Foram verificados os coeficientes de correlação de pearson entre as variáveis acima citadas e adotou-se um p<0.05 para associação significativa. Foi encontrada uma associação negativa significativa entre a EIQUA e todos os testes de força analisados, bem como com os testes funcionais. A EMQUA também apresentou correlação significativa, porém positiva, com os testes de força e funcionalidade. A EIQUA apresentou uma associação significativa com a gordura visceral, bem como com a gordura subcutânea da coxa. Além disso, a gordura subcutânea abdominal apresentou associação significativa com a DMF. Os dados do presente estudo mostraram haver uma associação significativa entre a quantidade e qualidade muscular e o desempenho em testes de força e funcionais em indivíduos obesos. Ainda, importantes parâmetros de adiposidade se correlacionaram com a EIQUA e com a DMF, um importante marcador de saúde endotelial. Dessa forma, estartégias de intervenção (por exemplo, treinamento de força), que sejam capazes de modificar os parâmetros acima descritos, devem ser priorizadas quando o objetivo for uma melhora na qualidade de vida de indivíduos obesos. / Obesity levels are increasing in Brazil and all over the world in an exponential way. The adipose tissue excess may affect functionality, as well as another health parameters. The skeletal muscle quantity and quality in obese individual may be determinant in how that the organism deals with theses problems. Thus, the objective of the present study was to verify the association between strength, muscle quantity and quality, functionality, vascular health and adiposity in obese subjects. Thirty four obese subjects, aged 20-60 years, sedentary, non-smokers and non-diabetic, volunteered to participate in the study. After a familiartization session, the knee extensors strength (isometric maximal volunatry contraction - IMVC; on repetition maximum - 1RM ; average power) and functional (6 minutes walk test - TC6M; sit to stand up test - 30SL; get up and go) tests were performed. The quadriceps femoris muscle thickness (EMQUA) and echo intensity (EIQUA) were evaluated by ultrasonography, as well as different adiposty parameters and vascular function. The pearson correlation coefficent were verified between all variables cited above and a P<0.05 were adopted. There was found a negative significant association between the EIQUA and all the strength tests performed, as well as all functional tests. The EMQUA presented significant positive association with all strength and functional tests. Additionally, the EIQUA presented a significant negative association with the visceral adipose tissue, as well as the thigh subcutaneous adipose tissue. Besides that, the abdominal subcutaneous adipose tissue was associated positively with the vascular function. The data presented here have shown a significant association between the muscle quantity and quality and the performance in functional and strength tests in obese subjects. In addition, important adiposity parameters correlated with the EIQUA and vascular function. Thus, intervention strategies (such as strength training), that are capable of modifying these parameters, should be prioritized when the objective is to enhance the quality of life in an obese person.

This aim of this thesis was to compare the value of ecological functions of two areas with different intensity of the agricultural management. The expert methods of Seják et al. (2003, 2010) were used for the calculation of the ecological value of the area and of the value of ecosystem services. The BVM (Biotope Valuation Method) was used for the calculation of the ecological value. The Replacement Cost method was used for the calculation of the value of ecosystem services. The following services were evaluated: the flood-protective, production of the above-ground biomass, retention of the nutrients, support of biodiversity, production of oxygen, climatical service, and support of small water cycle. The rate of tillage was used as the indicator of the intensity of the agricultural management (25 % for the area I and 83 % for the area II), which corresponded to the proportion of natural biotops (60 biotops with total area of 108 ha in area I and 35 biotops with total area of 34 ha in area II).

Estudos epidemiológicos têm mostrado rápido aumento na prevalência de sobrepeso e obesidade, tanto na população adulta quanto em crianças e adolescentes, sendo o exercício físico considerado uma importante estratégia tanto na prevenção quanto no tratamento do ganho de peso. Apesar disso, estudos que avaliam os efeitos isolados do exercício físico no controle ponderal têm apresentado resultados conflitantes. Esses achados podem ser explicados por um possível efeito compensatório provocado pela sessão de exercício nas atividades físicas realizadas em períodos subsequentes. Portanto, o objetivo deste estudo é avaliar o efeito de diferentes intensidades do exercício físico no gasto energético com atividades físicas em adolescentes com excesso de peso. O desenho do estudo foi experimental do tipo crossover com realização de três sessões (controle, exercício moderado e exercício vigoroso). Vinte e quatro adolescentes de 11 a 13 anos, estudantes da rede municipal de ensino de Niterói-RJ, do sexo masculino e com excesso de peso concordaram em participar do estudo. O gasto energético com atividades físicas foi avaliado por acelerômetros triaxiais colocados durante as sessões experimentais e retirado após seis dias. Os dados referentes ao gasto energético associado às atividades físicas foram avaliados na 1 hora de utilização do acelerômetro e durante os seis dias de acompanhamento. Além disso, os valores também foram tratados de forma cumulativa, tendo sido calculado o gasto energético total de 24, 48, 72, 96, 120 e 144 horas. Análise de variância foi utilizada para avaliar as possíveis diferenças entre o gasto energético na primeira hora de registro entre os três grupos seguida do teste post hoc de Scheffé. A comparação das variações das médias de gasto energético (por dia e acumuladas) foi realizada por meio de modelos lineares mistos. A comparação do gasto energético durante a 1 hora de registro demonstrou diferença significativa entre todos três grupos, com médias de 82, 286 e 343 kcal para os grupos controle, moderado e intenso, respectivamente (p<0.001). O mesmo padrão de diferença para o gasto energético entre os grupos se manteve ao final de 24 horas (704 vs 970 vs 1056 kcal, p<0.001) e no gasto energético acumulado durante os seis dias de acompanhamento (5102 vs 5193 vs 5271 kcal, p<0.001). A análise do gasto energético por dia demonstrou uma redução do gasto energético dos grupos moderado e vigoroso a partir do segundo dia e que se manteve até o sexto dia de acompanhamento. Desse modo, pode-se concluir que uma única sessão de exercício físico aeróbio parece modificar o comportamento das atividades físicas espontâneas realizadas ao longo de 6 dias em adolescentes com excesso de peso. Entretanto, apesar do efeito compensatório observado, o gasto energético acumulado durante os seis dias para os grupos que realizaram as sessões de exercícios foi superior ao da sessão controle, tendo o grupo vigoroso apresentado o maior dispêndio acumulado para o período de acompanhamento. Futuros estudos são necessários de modo a investigar a compensação do gasto energético em obesos e não obesos e o efeito de um número maior de sessões de treinamento. / Epidemiological studies have shown rapid increase in the prevalence of overweight and obesity, both in adults and in children and adolescents and physical exercise considered an important strategy in the prevention and in the treatment of weight gain. Nevertheless, studies evaluating the isolated effects of exercise on weight control have shown conflicting results. These findings can be explained by a possible compensatory effect caused by exercise session in physical activities in subsequent periods. Therefore, the aim of this study is to evaluate the effect of different exercise intensities in energy expenditure with physical activity in adolescents with overweight. The study design was a crossover design with three sessions (control, moderate exercise and vigorous exercise). Twenty-four teenagers 11-13 years old, students from public schools in Niterói, Rio de Janeiro, male and overweight agreed to participate. The energy spent on physical activity was assessed by triaxial accelerometers placed during the experimental sessions and removed after six days. The data relating to energy expenditure associated with physical activity were assessed in 1st hour of using the accelerometer and during the six days of monitoring. In addition, values were also treated cumulatively, it has been calculated total energy expenditure of 24, 48, 72, 96, 120 and 144 hours. Analysis of variance was used to evaluate the possible differences between the energy expenditure in the first hour of registration between the three groups then the post hoc Scheffé. A comparison of the mean changes in energy expenditure (per day cumulative) was performed by mixed linear model. Comparison of energy expenditure during the 1st time showed significant differences between all three groups, with averages of 82, 286 and 343 kcal to the control group, moderate and intense, respectively (p <0.001). The same pattern of difference in energy expenditure between the groups remained after 24 hours (704 vs 970 vs 1056 kcal, p <0.001) and the cumulative energy expenditure during the six days of monitoring (5102 vs 5193 vs 5271 kcal, p <0.001). The analysis of energy expenditure per day demonstrated a reduction in energy expenditure of moderate and vigorous groups from the second day and remained until the sixth day of monitoring. Thus, we can conclude that a single aerobic workout seems to modify the behavior of spontaneous physical activities over 6 days in adolescents with overweight. However, despite the observed compensatory effect, the cumulative energy expenditure during the six days for the groups that carried out the exercise sessions was higher than the control session, with the vigorous group presented the highest accumulated expenditure for the follow-up period. Future studies are needed to investigate the compensation of energy expenditure in obese and nonobese patients and the effect of a greater number of training sessions.

Made available in DSpace on 2014-06-11T19:25:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-15Bitstream added on 2014-06-13T19:53:41Z : No. of bitstreams: 1 riso_ndm_me_araca.pdf: 482066 bytes, checksum: c4d4bd9489b24dc5a0d0ecb1f0a59459 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Laser de baixa intensidade tem sido utilizado como agente físico em várias áreas das ciências médicas no reparo ósseo e tecidual. Entretanto pouco se sabe sobre seus efeitos em condições adversas como supressão de carga e osteopenia. Com a hipótese que o laser As-Ga-Al acelera o processo de consolidação óssea, foi objetivo deste estudo avaliar a densidade mineral óssea (DMO), e parâmetros histológicos em tíbias osteotomizadas de ratos Wistar, adultos, tratados com laser terapêutico de baixa intensidade em três diferentes grupos: G1 (n=10), referência 15 dias, osteotomizados, tratados com laser por 12 sessões e mantidos livres na gaiola; G2 (n=10), osteotomizados, suspenso pela cauda por 15 dias e tratados concomitantemente com Laser por 12 sessões; G3 (n=10), osteotomizados, suspenso pela cauda por 36 dias sendo que, após o 21º dia, iniciou-se tratamento com laser por 12 sessões, sendo a tíbia direita teste, irradiada com o laser e a esquerda controle. O laser utilizado foi de As-Ga-Al, DMC - Flash Lase III®, com comprimento de onda 830nm, 100 mW, 4J, 140 J/cm², 40s de aplicação em 12 sessões. Utilizou-se densitômetro DPX-Lunar®, com programa computacional para pequenos animais, e a análise comparativa foi feita em toda tíbia e na região da osteotomia. Análise histomorfométrica foi realizada com programa computacional Osteomesure®. Nossos resultados não demonstraram eficácia da terapia laser no processo de reparação óssea, o que discorda de muitos trabalhos. Uma possível explicação para estes resultados é que os efeitos da terapia laser de baixa potência possam ser manifestadas não só no local da irradiação como também a nível sistêmico. / Low-intensity laser has been used as a physical agent in various fields of medical sciences such as bone and tissue repair. Meanwhile little is known about its effects in adverse conditions such as abolition of load and osteopenic. With the assumption that the laser As-Ga-Al accelerates the process of consolidation bone, purpose of this study was to evaluate the bone mineral density - BMD, and histological parameters in tibia osteotomized of rats, adults, treated with laser of low intensity in three different groups: G1 (n = 10), reference 15 days, osteotomized, treated with laser for 12 sessions in the cage and kept free; G2 (n = 10), osteotomized, suspended by the tail for 15 days and treated concurrently with Laser for 12 sessions; G3 (n = 10), osteotomized, suspended by the tail by 36 days and, after the 21 th day, started up with laser treatment for 12 sessions, and the right tibia test, irradiated with the laser and left control. The laser was used to As-Ga-Al, DMC - Flash Lase ® III, with wavelength 830nm, 100 mW, 4J, 140 J / cm ², 40s of application in 12 sessions. It was used densitometer-Lunar DPX®, with computer program for small animals, and the analysis was made in the bone throughout the region and the osteotomy. Histomorphometric analysis was performed with computer program Osteomesure®. Our results have not demonstrated effectiveness of laser therapy in the process of repairing bone, which disagrees with many works. One possible explanation for these results is that the effects of low-power laser therapy can be expressed not only in place of irradiation as well as systemic level.

Cell-derived microvesicles (MVs) are naturally released into the human circulation and an increase in the concentration of certain MV populations have been observed after exercise. However, the MV appearance dynamics, the exercise-related stimuli that induce their formation and physiological relevance are poorly understood. Hence, the overall objectives of this thesis were to: 1) characterise the circulating platelet (PMV) and endothelial-derived MVs (EMVs) responses during exercise and recovery, as well as their arteriovenous dynamics, 2) investigate the potential role of haemodynamic forces on MVs formation in vivo by vascular shear stress manipulations, and 3) explore the putative proliferative, chemotactic and angiogenic potential of exercise-derived MVs upon human vascular endothelial cells in vitro. Chapter 5 of this thesis describes the time-course of MV appearance in response to prolonged cycling, and demonstrates that intravascular [PMV] increases during and after exercise performed in the heavy intensity domain, whereas [EMV] remains unaltered. Moreover, [PMV] during exercise was related to estimates of vascular shear stress and plasma noradrenaline levels. Results from chapter 6 revealed that PMVs increased in the arterial circulation during passive heat stress, and in the arterial as well as venous circulation during short duration very heavy exercise engaging either a large or small muscle mass. The increases in [PMV] were not directly linked to local changes in vascular shear stress through heat stress and exercise, indicating a systemic PMV response. Finally, chapter 7 revealed that exercise-derived MVs supported endothelial proliferation and migration, while displaying pro-angiogenic potential in vitro. In conclusion, results of this thesis provide original information about MV dynamics, by demonstrating that PMV increase systemically in the circulation not only after but during exercise involving a small and large muscle mass. This MV response seems to be modulated by exercise intensity, and is only partially linked to levels of vascular shear stress. Moreover, circulating MVs produced during exercise present stimulatory angiogenic and mitogenic effects upon endothelial cells in vitro, suggesting a novel potential link between vascular adaptation and exercise training.

abstract: Microplastics are emerging to be major problem when it comes to water pollution and they pose a great threat to marine life. These materials have the potential to affect a wide range of human population since humans are the major consumers of marine organisms. Microplastics are less than 5 mm in diameter, and can escape from traditional wastewater treatment plant (WWTP) processes and end up in our water sources. Due to their small size, they have a large surface area and can react with chlorine, which it encounters in the final stages of WWTP. After the microplastics accumulate in various bodies of water, they are exposed to sunlight, which contains oxidative ultraviolet (UV) light. Since the microplastics are exposed to oxidants during and after the treatment, there is a strong chance that they will undergo chemical and/or physical changes. The WWTP conditions were replicated in the lab by varying the concentrations of chlorine from 70 to 100 mg/L in increments of 10 mg/L and incubating the samples in chlorine baths for 1–9 days. The chlorinated samples were tested for any structural changes using Raman spectroscopy. High density polyethylene (HDPE), polystyrene (PS), and polypropylene (PP) were treated in chlorine baths and observed for Raman intensity variations, Raman peak shifts, and the formation of new peaks over different exposure times. HDPE responded with a lot of oxidation peaks and shifts of peaks after just one day. For the degradation of semi-crystalline polymers, there was a reduction in crystallinity, as verified by thermal analysis. There was a decrease in the enthalpy of melting as well as the melting temperature with an increase in the exposure time or chlorine concentration, which pointed at the degradation of plastics and bond cleavages. To test the plastic response to ii UV, the samples were exposed to sunlight for up to 210 days and analyzed under Raman spectroscopy. Overall the physical and chemical changes with the polymers are evident and makes a way for the wastewater treatment plant to take necessary steps to capture the microplastics to avoid the release of any kind of degraded microplastics that could affect marine life and the environment. / Dissertation/Thesis / Masters Thesis Chemical Engineering 2017

This project aims to characterise the fatigue behaviour of a crack propagating in a residual stress field changing from tension to compression in the welded zone of a ferritic pressure vessel steel. The fatigue tests were carried out keeping the applied stress intensity factor range constant to determine the role of residual stresses on fatigue crack growth. The residual stresses prior to crack growth were evaluated by X-ray diffraction. The weight function method was used to infer the expected influence of the residual stress on the crack tip in terms of the residual stress intensity factor. Two metrics were used to quantify the crack driving force local to the fatigue crack. Firstly the stress intensity amplitude expressed in terms of the change in the J-integral between maximum and minimum load and secondly the change in the crack opening displacement COD to estimate closure stress intensity factor. The displacement fields local to a fatigue crack were obtained by Digital Image Correlation (DIC) and then analysed by JMAN, an in-house developed algorithm to extract the J-integral based on finite element method and implemented using MATLAB. The difference between the applied stress intensity factor range and the effective crack driving force at the crack tip was determined in order to understand the interaction between the prior residual stresses and crack closure phenomena. Three different R-ratios were evaluated during the experiment (R=0.1, R=0.3 and R=0.5) in order to quantify the effect of residual stress on crack tip stress intensity and crack opening displacement. R-ratio plays a very important role on the fatigue crack growth rate (FCGR): as R increases, FCGR also increases. The COD was assessed by means of the displacements obtained by DIC local to the crack faces. The COD method turned out to be more insightful than the JMAN method for characterising the crack propagation, this is due to the presence of plasticity in the ligament which breaks the non-linear elastic conditions, causing the path-dependence on the J-integral. The FCGR is influenced to a greater degree by the R-ratio and to a lesser degree by the residual stress effect. There is a direct relationship between R and FCGR: as R increases, FCGR also increases, irrespective of the presence of tensile or compressive residual stresses, with the crack closure showing more tendency to occur at low R (i.e. R=0.1) than at high R (i.e. R=0.5). The relationship between R and the residual stress effects on FCGR is inversely proportional: as R increases, the effect of RS decreases.