797 resultados para WORKING-CONDITIONS
Resumo:
We propose an immediately realizable scheme showing signatures of multipartite entanglement generated by radiation pressure in a cavity system with a movable mirror. We show how the entanglement involving the inaccessible massive object is unraveled by means of field-field quantum correlations and persists within a wide range of working conditions. Our proposal provides an operative way to infer the quantum behavior of a system that is only partially accessible.
Resumo:
Self-compacting concrete (SCC) flows into place and around obstructions under its own weight to fill the formwork completely and self-compact without any segregation and blocking. Elimination of the need for compaction leads to better quality concrete and substantial improvement of working conditions. This investigation aimed to show possible applicability of genetic programming (GP) to model and formulate the fresh and hardened properties of self-compacting concrete (SCC) containing pulverised fuel ash (PFA) based on experimental data. Twenty-six mixes were made with 0.38 to 0.72 water-to-binder ratio (W/B), 183–317 kg/m3 of cement content, 29–261 kg/m3 of PFA, and 0 to 1% of superplasticizer, by mass of powder. Parameters of SCC mixes modelled by genetic programming were the slump flow, JRing combined to the Orimet, JRing combined to cone, and the compressive strength at 7, 28 and 90 days. GP is constructed of training and testing data using the experimental results obtained in this study. The results of genetic programming models are compared with experimental results and are found to be quite accurate. GP has showed a strong potential as a feasible tool for modelling the fresh properties and the compressive strength of SCC containing PFA and produced analytical prediction of these properties as a function as the mix ingredients. Results showed that the GP model thus developed is not only capable of accurately predicting the slump flow, JRing combined to the Orimet, JRing combined to cone, and the compressive strength used in the training process, but it can also effectively predict the above properties for new mixes designed within the practical range with the variation of mix ingredients.
Resumo:
Determination of metal oxidation state under relevant working conditions is crucial to understand catalytic behaviour. The reduction behaviour of Pt and Re was evaluated simultaneously as a function of support and solvent in a pressurized reactor (autoclave). The bimetallic catalysts are used in selective hydrogenation of carboxylic acids and amides. Gas phase reduction reduced the metals more efficiently, in particular Pt.
Resumo:
BACKGROUND: We examined the effects of leaving public sector general practitioner (GP) work and of taking a GP position on changes in work-related psychosocial factors, such as time pressure, patient-related stress, distress and work interference with family. In addition, we examined whether changes in time pressure and patient-related stress mediated the association of employment change with changes of distress and work interference with family. METHODS: Participants were 1705 Finnish physicians (60% women) who responded to surveys in 2006 and 2010. Analyses of covariance were conducted to examine the effect of employment change to outcome changes adjusted for gender, age and response format. Mediational effects were tested following the procedures outlined by Baron and Kenny. RESULTS: Employment change was significantly associated with all the outcomes. Leaving public sector GP work was associated with substantially decreased time pressure, patient-related stress, distress and work interference with family. In contrast, taking a position as a public sector GP was associated with an increase in these factors. Mediation tests suggested that the associations of employment change with distress change and work interference with family change were partially explained by the changes in time pressure and patient-related stress. CONCLUSIONS: Our results showed that leaving public sector GP work is associated with favourable outcomes, whereas taking a GP position in the public sector is associated with adverse effects. Primary health-care organizations should pay more attention to the working conditions of their GPs, in particular, to time pressure and patient-related stress.
Resumo:
Background: An increasingly significant public health issue in Canada, and elsewhere throughout the developed world, pertains to the provision of adequate palliative/end-of-life (P/EOL) care. Informal caregivers who take on the responsibility of providing P/EOL care often experience negative physical, mental, emotional, social and economic consequences. In this article, we specifically examine how Canada's Compassionate Care Benefit (CCB) - a contributory benefits social program aimed at informal P/EOL caregivers - operates as a public health response in sustaining informal caregivers providing P/EOL care, and whether or not it adequately addresses known aspects of caregiver burden that are addressed within the population health promotion (PHP) model. Methods. As part of a national evaluation of Canada's Compassionate Care Benefit, 57 telephone interviews were conducted with Canadian informal P/EOL caregivers in 5 different provinces, pertaining to the strengths and weaknesses of the CCB and the general caregiving experience. Interview data was coded with Nvivo software and emerging themes were identified by the research team, with such findings published elsewhere. The purpose of the present analysis was identified after comparing the findings to the literature specific to caregiver burden and public health, after which data was analyzed using the PHP model as a guiding framework. Results: Informal caregivers spoke to several of the determinants of health outlined in the PHP model that are implicated in their burden experience: gender, income and social status, working conditions, health and social services, social support network, and personal health practises and coping strategies. They recognized the need for improving the CCB to better address these determinants. Conclusions: This study, from the perspective of family caregivers, demonstrates that the CCB is not living up to its full potential in sustaining informal P/EOL caregivers. Effort is required to transform the CCB so that it may fulfill the potential it holds for serving as one public health response to caregiver burden that forms part of a healthy public policy that addresses the determinants of this burden. © 2011 Williams et al; licensee BioMed Central Ltd.
Resumo:
Recent debates and controversies have highlighted several issues surrounding sociological research, which relate to the general conditions under which it is undertaken and how this is changing. There is a pressing need to respond to these issues as a whole, in particular by examining what they tell us about research practices. This article argues that a consideration of themes raised by the American television drama The Wire is useful for facilitating such a response, since it may be read as a discussion of working conditions within neoliberal societies. The following themes are pertinent here: the need to reflect upon the terms by which research is framed by funders, to take adequate time to conduct and complete research, and to encourage critical debate within research. Whilst these relate to influential epistemological discussions by Pierre Bourdieu and Michael Burawoy, this reading of The Wire is particularly helpful for highlighting the practical and inter-relational situations in which sociological research is carried out but which tend not to receive the systematic attention they deserve.
Resumo:
This special issue volume is concerned with how technology is changing the nature of work and working conditions while generating new products and new forms of service delivery. The five articles included in this volume cover service work, from the routine and clerical through to highly credentialed and professional work. Although some of the established challenges concerning the impact of Information and Communication Technology (ICT) on work and workplaces are evident in the articles, it is also clear that new service delivery processes demand new skills and training to some extent. Overall findings indicate that while ICT competencies are important, they need to be supplemented by the soft skills that are crucial for effective customer interactions and more open work systems with greater autonomy and participation whereby flexible work teams can have a positive impact on job quality outcomes. This introductory article examines technology and the changing nature of work through three strands of interpretation, prior to introducing the five articles in this special issue.
Resumo:
The book considers the question whether the traditional prohibition of nightwork for female manual workers could be defended against EU (then: EEC) discrimination law requirements and against the German constitution itself. While I was working on the PhD, German labour law still prohibited manual workers (but not white collar employees, or nurses, or policewomen) from working nights. Just before the thesis was published, the German constitutional court held that the prohibition indeed violates the Constitution, but that it must not be repealed without providing for specific protection against health risks ensuing from night work. The Court thus mainly confirmed the thesis' results. The thesis first considers the history of the legislation (which was based on an ILO convention), and discusses the social and health risks related to night work. It then comes to the conclusion that gender roles imply that women are at a greater risk when working nights, but that there is no biological justification (except during pregnancy of course). The thesis further develops a recommendation, based on the constitutional welfare states principle and the constitutional protection of health, to not just abolish the prohibition, but to provide uplevel equalisation of working conditions for women and men. This was the first time I also tried to work comparatively (not perfect at all), but I have certainly improved since then. An English summary of the thesis was published in the 3rd issue of the Cardozo Women's Law Journal 1996, which was also my first ever publicatin in English
Resumo:
We propose a feedback control mechanism for the squeezing of the phononic mode of a mechanical oscillator. We show how, under appropriate working conditions, a simple adiabatic approach is able to induce mechanical squeezing. We then go beyond the limitations of such a working point and demonstrate the stationary squeezing induced by using repeated measurements and reinitialization of the state of a two-level system ancilla coupled to the oscillator. Our nonadaptive feedback loop offers interesting possibilities for quantum state engineering and steering in open-system scenarios.
Resumo:
EU Social and Labour Rights have developed incrementally, originally through a set of legislative initiatives creating selective employment rights, followed by a non-binding Charter of Social Rights. Only in 2009, social and labour rights became legally binding through the Charter of Fundamental Rights for the European Union (CFREU). By contrast, the EU Internal Market - an area without frontiers where goods, persons, services and capital can circulate freely – has been enshrined in legally enforceable Treaty provisions from 1958. These comprise the economic freedoms guaranteeing said free circulation and a system ensuring that competition is not distorted within the Internal Market (Protocol 27 to the Treaty of Lisbon). Tensions between Internal Market law and social and labour rights have been observed in analyses of EU case law and legislation. This study explores responses by socio-economic and political actors at national and EU levels to such tensions, focusing on collective labour rights, rights to fair working conditions and rights to social security and social assistance (Articles 12, 28, 31, 34 Charter of Fundamental Rights for the European Union). On the basis of the current Treaties and the CFREU, the constitutionally conditioned Internal Market emerges as a way to overcome the perception that social and labour rights limit Internal Market law, or vice versa. On this basis, alternative responses to perceived tensions are proposed, focused on posting of workers, furthering fair employment conditions through public procurement and enabling effective collective bargaining and industrial action in the Internal Market.
Resumo:
This paper revisits work on the socio-political amplification of risk, which predicts that those living in developing countries are exposed to greater risk than residents of developed nations. This prediction contrasts with the neoliberal expectation that market driven improvements in working conditions within industrialising/developing nations will lead to global convergence of hazard exposure levels. It also contradicts the assumption of risk society theorists that there will be an ubiquitous increase in risk exposure across the globe, which will primarily affect technically more advanced countries. Reviewing qualitative evidence on the impact of structural adjustment reforms in industrialising countries, the export of waste and hazardous waste recycling to these countries and new patterns of domestic industrialisation, the paper suggests that workers in industrialising countries continue to face far greater levels of hazard exposure than those of developed countries. This view is confirmed when a data set including 105 major multi-fatality industrial disasters from 1971 to 2000 is examined. The paper concludes that there is empirical support for the predictions of socio-political amplification of risk theory, which finds clear expression in the data in a consistent pattern of significantly greater fatality rates per industrial incident in industrialising/developing countries.
Resumo:
Esta tese relata estudos de síntese, caracterização da estrutura e das propriedades de fotoluminescência e aplicações de nanotubos e nanobastonetes de óxidos de lantanídeos em pontas para microscopia de força atómica, catálise heterogénea e compósitos de base polimérica. Há um interesse crescente em compreender como o confinamento quântico decorrente da redução do tamanho de partícula pode influenciar a eficiência da luminescência, a dinâmica dos estados excitados, a transferência de energia e os efeitos de termalização de nanoluminóforos. Em nanocristais dopados com lantanídeos (Ln3+), e apesar da localização dos estados 4f, ocorrem efeitos de confinamento quântico via interacção com os modos vibracionais da rede. Em particular, a termalização anómala, descrita para uma variedade de nanocristais dopados com Ln3+, tem sido atribuída à ausência de modos vibracionais de menor frequência. Este nanoconfinamento pode ter impacto na dinâmica da luminescência, bem como na transferência de energia mediada por modos vibracionais e processos de upconversion. Nesta tese, relata-se o estudo deste efeito em nanotubos de Gd2O3:Eu3+. A influência de parâmetros como a concentração de európio e as condições de calcinação também foi investigada. Algumas aplicações destes óxidos de lantanídeos também foram exploradas, nomeadamente a modificação de pontas usadas em microscopia de força atómica com nanobastonetes de Gd2O3:Eu3+, lograda através de dielectroforese, técnica que não degrada a emissão de luz (rendimento quântico 0.47). As pontas modificadas são estáveis sob condições de trabalho, podendo ser aplicadas, por exemplo, em microscopia óptica de varrimento de campo próximo (SNOM). A oxidação em fase líquida do etilbenzendo foi investigada usando como catalisador nanotubos de CeO2, em presença dos oxidantes hidroperóxido de t-butilo e H2O2, e do solvente acetonitrilo, e temperaturas entre 55 e 105 ºC. Nanobastonetes de Gd2O3:Eu3+ recobertos com sílica foram preparados pelo método sol-gel. Esta cobertura resultou num aumento, quer do rendimento quântico de emissão, de 0.51 para 0.86 (excitação a 255 nm), quer dos tempos de vida,de 1.43 para 1.80 ms (excitação a 394.4 nm). A superfície dos nanotubos cobertos com sílica foi modificada com o agente de acoplamento metacrilato de 3-(trimetoxissilil)propilo que permitiu a preparação de compósitos através da subsequente polimerização in-situ do estireno por técnicas de miniemulsão e solução. ABSTRACT: This thesis reports on the synthesis, characterisation of the structure and photoluminescence properties, and applications of nanotubes and nanorods of lanthanides oxides in atomic force microscopy tips, heterogeneous catalysis and polymer-base composites. There is a growing interest in understanding how size-dependent quantum confinement affects the photoluminescence efficiency, excited-state dynamics, energy-transfer and thermalisation phenomena in nanophosphors. For lanthanide (Ln3+)-doped nanocrystals, and despite the localisation of the 4f states, confinement effects are induced mostly via electron-phonon interactions. In particular, the anomalous thermalisation reported for a handful of Ln3+-doped nanocrystals has been rationalised by the absence of lowfrequency phonon modes. This nanoconfinement may further impact on the Ln3+ luminescence dynamics, such as phonon-assisted energy transfer or upconversion processes. Here, this effect is investigated in Gd2O3:Eu3+ nanotubes. The influence of parameters such as europium concentration and calcination procedure is also studied. Some applications of these lanthanides oxides have been explored, for instance the modification of atomic force microscopy tips with photoluminescent Gd2O3:Eu3+ nanorods, using dielectrophoresis, a technique which preserves the red emission of the nanorods (quantum yield 0.47). The modified tips are stable under working conditions and may find applications in scanning near-field optical microscopy. The liquid-phase oxidation of ethylbenzene over CeO2 nanotubes has been investigated, using tert-butyl-hydroperoxide and H2O2 as the oxidising agents, and acetonitrile as the solvent, in the range 55-105 ºC. Gd2O3:Eu3+ nanorods have been coated with silica via a sol-gel approach. The silica coating increases both, the Eu3+ absolute emission quantum yields from 0.51 to 0.86 (255 nm excitation), and decay times from 1.43 to 1.80 ms (394.4 nm excitation). The silica coating was modified with 3- (trimethoxysilyl) propyl methacrylate and, subsequently, composites have been prepared by in-situ radical polymerisation of styrene via miniemulsion and solution routes.
Resumo:
Tese de doutoramento, Química (Química Tecnológica), Universidade de Lisboa, Faculdade de Ciências, 2014
Resumo:
A manufacturing system has a natural dynamic nature observed through several kinds of random occurrences and perturbations on working conditions and requirements over time. For this kind of environment it is important the ability to efficient and effectively adapt, on a continuous basis, existing schedules according to the referred disturbances, keeping performance levels. The application of Meta-Heuristics and Multi-Agent Systems to the resolution of this class of real world scheduling problems seems really promising. This paper presents a prototype for MASDScheGATS (Multi-Agent System for Distributed Manufacturing Scheduling with Genetic Algorithms and Tabu Search).
Resumo:
Tese de Doutoramento, Educação (Desenvolvimento Curricular), 9 de Dezembro de 2013, Universidade dos Açores.