The Effect of Sequence of Operations on Fatigue Life of LSP Treated Open-hole Aluminium Specimens

Fastener holes in aeronautical structures are typical sources of fatigue cracks due to their induced local stress concentration. A very efficient solution to this problem is to establish compressive residual stresses around the fastener holes that retard the fatigue crack nucleation and its subsequent local propagation. Previous work done on the subject of the application of LSP treatment on thin, open-hole specimens [1] has proven that the LSP effect on fatigue life of treated specimens can be detrimental, if the process is not properly optimized. In fact, it was shown that the capability of the LSP to introduce compressive residual stresses around fastener holes in thin-walled structures representative of typical aircraft constructions was not superior to the performance of conventional techniques, such as cold-working.

PubDNA Finder in a Nutshell. Searching the Life Sciences Literature with Sequences of Nucleic Acids

Biomedical researchers and clinicians working with molecular technologies in routine clinical practice often need to review the available literature to gather information regarding specific sequences of nucleic acids. This includes, for instance, finding articles related to a concrete DNA sequence, or identifying empirically-validated primer/probe sequences to evaluate the presence of different micro-organisms. Unfortunately, these hard and time-consuming tasks often need to be manually performed by researchers themselves since no publicly available biomedical literature search engine, e.g. PubMed, PubMed Central (PMC), etc., provides the required search functionalities. In this article, we describe PubDNA Finder, a web service that enables users to perform advanced searches on PubMed Central-indexed full text articles with sequences of nucleic acids

Instrumentation for accelerated life tests of concentrator solar cells

Concentrator photovoltaic is an emergent technology that may be a good economical and efficient alternative for the generation of electricity at a competitive cost. However, the reliability of these new solar cells and systems is still an open issue due to the high-irradiation level they are subjected to as well as the electrical and thermal stresses that they are expected to endure. To evaluate the reliability in a short period of time, accelerated aging tests are essential. Thermal aging tests for concentrator photovoltaic solar cells and systems under illumination are not available because no technical solution to the problem of reaching the working concentration inside a climatic chamber has been available. This work presents an automatic instrumentation system that overcomes the aforementioned limitation. Working conditions have been simulated by forward biasing the solar cells to the current they would handle at the working concentration (in this case, 700 and 1050 times the irradiance at one standard sun). The instrumentation system has been deployed for more than 10 000 h in a thermal aging test for III-V concentrator solar cells, in which the generated power evolution at different temperatures has been monitored. As a result of this test, the acceleration factor has been calculated, thus allowing for the degradation evolution at any temperature in addition to normal working conditions to be obtained.

PROFILE AND THE QUALITY OF LIFE OF LOGGERS

RESUMO – Objetivou-se com este estudo caracterizar o perfil e avaliar o nível de satisfação que reflete na qualidade de vida no trabalho (QVT) de trabalhadores da colheita de madeira de duas contratadas (C1 e C2), por duas grandes empresas do setor florestal, sendo uma do segmento de papel e celulose (PC) e, a outra, do segmento de carvão vegetal (CV). A avaliação ocorreu a partir da percepção dos trabalhadores das contratadas em questão, utilizando um modelo pré-concebido que contempla 11 blocos ou dimensões referentes a variáveis intervenientes e definidores da QVT, englobando 48 trabalhadores em três categorias funcionais: operador de motosserra (7 trabalhadores da C1 PC e 10 da C2 CV), ajudante de motosserrista (7 trabalhadores da C1 PC e 8 da C2 CV) e operador de carregador florestal (11 trabalhadores da C1 PC e 5 da C2 CV). Os dados referentes às variáveis intervenientes na QVT foram obtidos a partir de escala fechada do tipo Likert, com os escores variando de 1 a 7, em que 1 correspondeu ao nível "bastante insatisfeito" e 7, ao nível "bastante satisfeito". O perfil dos trabalhadores é de pessoa jovem, baixo nível de escolaridade e pouco tempo de serviço na empresa. Quanto ao nível de satisfação no trabalho, constatou-se que os trabalhadores da C1 PC se encontravam "satisfeitos" e os da C2 CV, "mediamente satisfeitos" com o trabalho e as condições proporcionadas pelas respectivas empresas, apesar de estatisticamente não ter sido detectada diferença entre os valores médios encontrados nas duas situações, pelo teste de Mediana (P>0,01). Os fatores que mais contribuíram para esses resultados favoráveis foram os benefícios extras oferecidos pelas prestadoras de serviços, as condições de segurança no trabalho e o contentamento com o emprego formal. ABSTRACT – The objective of this study was to characterize profile and satisfaction level, which reflects the quality of life (QOL) of forest workers of two contracts for harvest activities, one in the pulp and paper industry (PI) and another in charcoal industry (CI). The evaluation of the satisfaction indexes was carried out according to the workers perception by using a model including 11 parameters to reflect these workers QOL. The group study of 48 workers encompassed three functional categories: chainsaw operators (7 from C1 and 10 from C2), chainsaw operator's assistant (7 from C1 and 8 from C2), and log loader operators (11 from C1 and 5 from C2). Data regarding the factors involved in QOL were collected from a closed, Likert-type scale with scores ranging from 1-7, in which level 1 corresponded to "very dissatisfied" and level 7 to "very satisfied". The general profile of the group shows that most of them are young, with low level of education and employed in the companies for a short time. Overall, the employees of contractors of the paper and pulp industry are "satisfied" and those working for the charcoal company are only "moderately satisfied" with the work and policies offered by the respective companies, although no significant statistical difference was detected between the two groups, for the median test (P> 0.01). The main reasons behind these results are the general beneficts offered by the companies, the safety measurements and the overall satisfaction for been employed.

Preliminary temperature Accelerated Life Test (ALT) on III-V commercial concentrator triple-junction solar cells

A quantitative temperature accelerated life test on sixty GaInP/GaInAs/Ge triple-junction commercial concentrator solar cells is being carried out. The final objective of this experiment is to evaluate the reliability, warranty period, and failure mechanism of high concentration solar cells in a moderate period of time. The acceleration of the degradation is realized by subjecting the solar cells at temperatures markedly higher than the nominal working temperature under a concentrator Three experiments at three different temperatures are necessary in order to obtain the acceleration factor which relates the time at the stress level with the time at nominal working conditions. . However, up to now only the test at the highest temperature has finished. Therefore, we can not provide complete reliability information but we have analyzed the life data and the failure mode of the solar cells inside the climatic chamber at the highest temperature. The failures have been all of them catastrophic. In fact, the solar cells have turned into short circuits. We have fitted the failure distribution to a two parameters Weibull function. The failures are wear-out type. We have observed that the busbar and the surrounding fingers are completely deteriorate

Evaluation of the reliability of commercial concentrator triple-junction solar cells by means of accelerated life tests (ALT)

A temperature accelerated life test on commercial concentrator lattice-matched GaInP/GaInAs/Ge triple-junction solar cells has been carried out. The solar cells have been tested at three different temperatures: 119, 126 and 164 °C and the nominal photo-current condition (820 X) has been emulated by injecting current in darkness. All the solar cells have presented catastrophic failures. The failure distributions at the three tested temperatures have been fitted to an Arrhenius-Weibull model. An Arrhenius activation energy of 1.58 eV was determined from the fit. The main reliability functions and parameters (reliability function, instantaneous failure rate, mean time to failure, warranty time) of these solar cells at the nominal working temperature (80 °C) have been obtained. The warranty time obtained for a failure population of 5 % has been 69 years. Thus, a long-term warranty could be offered for these particular solar cells working at 820 X, 8 hours per day at 80 °C.

Gender inequalities in occupational health related to the unequal distribution of working and employment conditions: a systematic review

Introduction: Gender inequalities exist in work life, but little is known about their presence in relation to factors examined in occupation health settings. The aim of this study was to identify and summarize the working and employment conditions described as determinants of gender inequalities in occupational health in studies related to occupational health published between 1999 and 2010. Methods: A systematic literature review was undertaken of studies available in MEDLINE, EMBASE, Sociological Abstracts, LILACS, EconLit and CINAHL between 1999 and 2010. Epidemiologic studies were selected by applying a set of inclusion criteria to the title, abstract, and complete text. The quality of the studies was also assessed. Selected studies were qualitatively analysed, resulting in a compilation of all differences between women and men in the prevalence of exposure to working and employment conditions and work-related health problems as outcomes. Results: Most of the 30 studies included were conducted in Europe (n=19) and had a cross-sectional design (n=24). The most common topic analysed was related to the exposure to work-related psychosocial hazards (n=8). Employed women had more job insecurity, lower control, worse contractual working conditions and poorer self-perceived physical and mental health than men did. Conversely, employed men had a higher degree of physically demanding work, lower support, higher levels of effort-reward imbalance, higher job status, were more exposed to noise and worked longer hours than women did. Conclusions: This systematic review has identified a set of working and employment conditions as determinants of gender inequalities in occupational health from the occupational health literature. These results may be useful to policy makers seeking to reduce gender inequalities in occupational health, and to researchers wishing to analyse these determinants in greater depth.

A qualitative exploration of the impact of the economic recession in Spain on working, living and health conditions: reflections based on immigrant workers' experiences

Background: This study aimed to analyse how immigrant workers in Spain experienced changes in their working and employment conditions brought about Spain's economic recession and the impact of these changes on their living conditions and health status. Method: We conducted a grounded theory study. Data were obtained through six focus group discussions with immigrant workers (n = 44) from Colombia, Ecuador and Morocco, and two individual interviews with key informants from Romania living in Spain, selected by theoretical sample. Results: Three categories related to the crisis emerged – previous labour experiences, employment consequences and individual consequences – that show how immigrant workers in Spain (i) understand the change in employment and working conditions conditioned by their experiences in the period prior to the crisis, and (ii) experienced the deterioration in their quality of life and health as consequences of the worsening of employment and working conditions during times of economic recession. Conclusion: The negative impact of the financial crisis on immigrant workers may increase their social vulnerability, potentially leading to the failure of their migratory project and a return to their home countries. Policy makers should take measures to minimize the negative impact of economic crisis on the occupational health of migrant workers in order to strengthen social protection and promote health and well-being.

Standbild und Integrationsaussichten der ausländischen Bevölkerung Südtirols. Gesellschaftsleben, Sprache, Religion und Wertehaltung = Integration prospects for the foreign population in South Tyrol. Social life, language, and religious values

No abstract.

When do adults learn? A cohort analysis of adult education in Europe. CEPS Working Document No. 383, 21 May 2013

Adult learning is seen as a key factor for enhancing employment, innovation and growth, and it should concern all age cohorts. The aim of this paper is to understand the points in the life cycle at which adult learning takes place and whether it leads to reaching a medium or high level of educational attainment. To this end we perform a synthetic panel analysis of adult learning for cohorts aged 25 to 64 in 27 European countries using the European Labour Force Survey. We find, as previous results suggest, that a rise in educational attainment as well as participation in education and training happens mostly at the age range of 25-29. However, investment across the life cycle by cohorts older than 25 still occurs: in most countries in our sample, participation in education and training as well as educational attainment increases observably across all cohorts. We also find that the decline with age slows down or is even reversed for older cohorts, for both participation in education and educational attainment. Finally, we can identify a Nordic model in which adult learning is achieved through participation in education and training, a Central European model in which adult learning occurs in the form of increasing educational attainment and a liberal model in which both approaches to adult learning are observable.