Avaliação da influência de diferentes óleos extensores com baixo teor de policíclicos aromáticos nas propriedades da borracha à base butadieno e estireno (SBR)

O óleo extensor normalmente empregado em copolímeros à base de butadieno e estireno ( borracha SBR) da série 1712 é o extrato aromático (DAE). Nesta Dissertação, esse óleo foi substituído por óleos com baixos teores de policíclicos aromáticos em formulações de SBR. Esta substituição se deu em atendimento a Regulamentação REACH (EC No1907/2006 do Parlamento Europeu e do Conselho de 18 de Dezembro de 2006, Anexo XVII) que determina que a soma de hidrocarbonetos policíclicos aromáticos individuais (PAHs) deve ser abaixo de 10 mg/kg e o teor de benzo(a)pireno (BaP) não deve exceder 1 mg/kg. Os óleos empregados foram o extrato aromático residual tratado (TRAE) e dois óleos naftênicos de fornecedores diferentes (HN1 e HN2). As composições de SBR estendidas em DAE, TRAE, HN1 e HN2 tiveram suas propriedades térmicas avaliadas por análise termogravimétrica (TG) e calorimetria diferencial de varredura (DSC). As propriedades físicas foram determinadas por ensaios de tração, dureza, resistência à abrasão e resiliência. Foram ainda avaliadas as propriedades reométricas e reológicas, por viscosidade e relaxação Mooney, respectivamente. Ao final os resultados demonstraram que é possível a substituição do óleo extensor por quaisquer dos óleos testados sem prejuízos nas propriedades estudadas

大型光学镜子热弹性变形的有限元分析

简述了利用ANSYS软件对大型光学镜子热弹性变形进行有限元分析的一般方法，强调了在分析过程中应该注意的一些问题和实用技巧，并给出了一个分析透镜重力变形的实例。

I. Numerical solution of exact pair equations. II. Numerical solution of first-order pair equations

Part I

Numerical solutions to the S-limit equations for the helium ground state and excited triplet state and the hydride ion ground state are obtained with the second and fourth difference approximations. The results for the ground states are superior to previously reported values. The coupled equations resulting from the partial wave expansion of the exact helium atom wavefunction were solved giving accurate S-, P-, D-, F-, and G-limits. The G-limit is -2.90351 a.u. compared to the exact value of the energy of -2.90372 a.u.

Part II

The pair functions which determine the exact first-order wavefunction for the ground state of the three-electron atom are found with the matrix finite difference method. The second- and third-order energies for the (1s1s)¹S, (1s2s)³S, and (1s2s)¹S states of the two-electron atom are presented along with contour and perspective plots of the pair functions. The total energy for the three-electron atom with a nuclear charge Z is found to be E(Z) = -1.125•Z² +1.022805•Z-0.408138-0.025515•(1/Z)+O(1/Z²)a.u.

Nicolao de Mura, "Progumnásmata"

[ES] Los Ejercicios preparatorios (προγυμνάσματα, Progumnásmata, lat. Praexercitamina) de Nicolao de Mura fueron escritos en el siglo V d. C., de manera que son posteriores al de Teón (siglo I), al atribuido a Hermógenes (siglo II) y al de Aftonio (siglo IV). En este trabajo se publica la primera traducción al español de esta obra. Esta traducción está precedida de una Introducción y está comentada en notas; finalmente, se añade un léxico de los términos retóricos en ella utilizados.

Localization of sources of human evoked responses

The evoked response, a signal present in the electro-encephalogram when specific sense modalities are stimulated with brief sensory inputs, has not yet revealed as much about brain function as it apparently promised when first recorded in the late 1940's. One of the problems has been to record the responses at a large number of points on the surface of the head; thus in order to achieve greater spatial resolution than previously attained, a 50-channel recording system was designed to monitor experiments with human visually evoked responses.

Conventional voltage versus time plots of the responses were found inadequate as a means of making qualitative studies of such a large data space. This problem was solved by creating a graphical display of the responses in the form of equipotential maps of the activity at successive instants during the complete response. In order to ascertain the necessary complexity of any models of the responses, factor analytic procedures were used to show that models characterized by only five or six independent parameters could adequately represent the variability in all recording channels.

One type of equivalent source for the responses which meets these specifications is the electrostatic dipole. Two different dipole models were studied: the dipole in a homogeneous sphere and the dipole in a sphere comprised of two spherical shells (of different conductivities) concentric with and enclosing a homogeneous sphere of a third conductivity. These models were used to determine nonlinear least squares fits of dipole parameters to a given potential distribution on the surface of a spherical approximation to the head. Numerous tests of the procedures were conducted with problems having known solutions. After these theoretical studies demonstrated the applicability of the technique, the models were used to determine inverse solutions for the evoked response potentials at various times throughout the responses. It was found that reliable estimates of the location and strength of cortical activity were obtained, and that the two models differed only slightly in their inverse solutions. These techniques enabled information flow in the brain, as indicated by locations and strengths of active sites, to be followed throughout the evoked response.

Proceedings of the first world meeting on bigeye tuna

The annual catches of big eye are exceeded by those of only two other species of tuna, skipjack, Katsuwonus pelamis, and yellowfin, Thunnus albacares. However, because most of the bigeye caught are consumed fresh, whereas most of the skipjack and yellowfin caught are canned, the economic value of big eye exceeds that of any other species of tuna. Despite its importance, less is known of the biology of bigeye than of the biology of any of the other principal market species of tunas. Historically, bigeye have been harvested mostly by longlines, which take only medium to large fish. During recent years, however, greater amounts of small bigeye have been caught by purse seines and other surface gear. This is a matter of concern for several reasons. First, long line fishermen are concerned that the harvesting of small bigeye will decrease the amounts of medium to large bigeye available to them. Second, since small bigeye are canned, rather than eaten fresh, consumers are concerned about the possible decrease in the supply of high-quality fresh fish. Third, economists are concerned about the possible economic loss associated with harvesting fish at less than their maximum economic value. Fourth, biologists are concerned about the possibility that harvesting of small bigeye could decrease the overall catches of that species. These concerns cannot be properly addressed until more knowledge of the biology of big eye is available. The purposes of the meeting were to review and discuss the information available and to make recommendations for further research.

Uptake and factors that influence the use of 'sit less, move more' occupational intervention strategies in Spanish office employees

Background: Little is known about the types of 'sit less, move more' strategies that appeal to office employees, or what factors influence their use. This study assessed the uptake of strategies in Spanish university office employees engaged in an intervention, and those factors that enabled or limited strategy uptake. Methods: The study used a mixed method design. Semi-structured interviews were conducted with academics and administrators (n = 12; 44 +/- 12 mean SD age; 6 women) at three points across the five-month intervention, and data used to identify factors that influenced the uptake of strategies. Employees who finished the intervention then completed a survey rating (n = 88; 42 +/- 8 mean SD age; 51 women) the extent to which strategies were used [never (1) to usually (4)]; additional survey items (generated from interviewee data) rated the impact of factors that enabled or limited strategy uptake [no influence (1) to very strong influence (4)]. Survey score distributions and averages were calculated and findings triangulated with interview data. Results: Relative to baseline, 67% of the sample increased step counts post intervention (n = 59); 60% decreased occupational sitting (n = 53). 'Active work tasks' and 'increases in walking intensity' were the strategies most frequently used by employees (89% and 94% sometimes or usually utilised these strategies); 'walk-talk meetings' and ` lunchtime walking groups' were the least used (80% and 96% hardly ever or never utilised these strategies). 'Sitting time and step count logging' was the most important enabler of behaviour change (mean survey score of 3.1 +/- 0.8); interviewees highlighted the motivational value of being able to view logged data through visual graphics in a dedicated website, and gain feedback on progress against set goals. 'Screen based work' (mean survey score of 3.2 +/- 0.8) was the most significant barrier limiting the uptake of strategies. Inherent time pressures and cultural norms that dictated sedentary work practices limited the adoption of 'walk-talk meetings' and ` lunch time walking groups'. Conclusions: The findings provide practical insights into which strategies and influences practitioners need to target to maximise the impact of 'sit less, move more' occupational intervention strategies.

Jean-Jacques Rousseau: por uma ética das virtudes

No âmbito da discussão filosófica sobre a moral, é possível perceber, nas últimas três décadas, um novo interesse pela denominada ética das virtudes. A ética das virtudes diz respeito a uma longa tradição de investigação moral que tem no conceito de virtudes, por oposição aos conceitos de leis, princípios, ou direitos, uma de suas ideias mais fundamentais. O objetivo desta dissertação de mestrado é elucidar de que forma o pensamento político e moral de Jean-Jacques Rousseau, ainda no contexto do Iluminismo, preserva os argumentos centrais da tradição da ética das virtudes. Embora Alasdair MacIntyre tenha contribuído bastante para o ressurgimento do interesse filosófico pela ética das virtudes, mostro nesta dissertação que as críticas que ele dirige de maneira generalizada ao Iluminismo não se aplicam de modo inteiramente adequado à posição que Rousseau efetivamente defende em seus escritos filosóficos. A obra de Rousseau é bastante vasta e, ao considerarmos alguns textos isoladamente, os argumentos que Rousseau apresenta parecem pouco sistemáticos. No entanto, como mostro na presente dissertação, ao analisarmos a obra de Rousseau como todo, fica bastante claro o quão a filosofia moral de Rousseau permanece fundamentalmente uma investigação sobre virtudes.

Integrating methods for determining length-at-age to improve growth estimates for two large scombrids

Fish growth is commonly estimated from length-at-age data obtained from otoliths. There are several techniques for estimating length-at-age from otoliths including 1) direct observed counts of annual increments; 2) age adjustment based on a categorization of otolith margins; 3) age adjustment based on known periods of spawning and annuli formation; 4) back-calculation to all annuli, and 5) back-calculation to the last annulus only. In this study we compared growth estimates (von Bertalanffy growth functions) obtained from the above five methods for estimating length-at-age from otoliths for two large scombrids: narrow-barred Spanish mackerel (Scomberomorus commerson) and broad-barred king mackerel (Scomberomorus semifasciatus). Likelihood ratio tests revealed that the largest differences in growth occurred between the back-calculation methods and the observed and adjusted methods for both species of mackerel. The pattern, however, was more pronounced for S. commerson than for S. semifasciatus, because of the pronounced effect of gear selectivity demonstrated for S. commerson. We propose a method of substituting length-at-age data from observed or adjusted methods with back-calculated length-at-age data to provide more appropriate estimates of population growth than those obtained with the individual methods alone, particularly when faster growing young fish are disproportionately selected for. Substitution of observed or adjusted length-at-age data with back-calculated length-at-age data provided more realistic estimates of length for younger ages than observed or adjusted methods as well as more realistic estimates of mean maximum length than those derived from backcalculation methods alone.

Patterns of Impact Resulting from a 'Sit Less, Move More' Web-Based Program in Sedentary Office Employees

Purpose Encouraging office workers to 'sit less and move more' encompasses two public health priorities. However, there is little evidence on the effectiveness of workplace interventions for reducing sitting, even less about the longer term effects of such interventions and still less on dual-focused interventions. This study assessed the short and mid-term impacts of a workplace web-based intervention (Walk@WorkSpain, W@WS; 2010-11) on self-reported sitting time, step counts and physical risk factors (waist circumference, BMI, blood pressure) for chronic disease. Methods Employees at six Spanish university campuses (n=264; 42 +/- 10 years; 171 female) were randomly assigned by worksite and campus to an Intervention (used W@WS; n=129; 87 female) or a Comparison group (maintained normal behavior; n=135; 84 female). This phased, 19-week program aimed to decrease occupational sitting time through increased incidental movement and short walks. A linear mixed model assessed changes in outcome measures between the baseline, ramping (8 weeks), maintenance (11 weeks) and follow-up (two months) phases for Intervention versus Comparison groups. Results A significant 2 (group) x 2 (program phases) interaction was found for self-reported occupational sitting (F[3]=7.97, p=0.046), daily step counts (F[3]=15.68, p=0.0013) and waist circumference (F[3]=11.67, p=0.0086). The Intervention group decreased minutes of daily occupational sitting while also increasing step counts from baseline (446 +/- 126; 8,862 +/- 2,475) through ramping (+425 +/- 120; 9,345 +/- 2,435), maintenance (+422 +/- 123; 9,638 +/- 3,131) and follow-up (+414 +/- 129; 9,786 +/- 3,205). In the Comparison group, compared to baseline (404 +/- 106), sitting time remained unchanged through ramping and maintenance, but decreased at follow-up (-388 +/- 120), while step counts diminished across all phases. The Intervention group significantly reduced waist circumference by 2.1cms from baseline to follow-up while the Comparison group reduced waist circumference by 1.3cms over the same period. Conclusions W@WSis a feasible and effective evidence-based intervention that can be successfully deployed with sedentary employees to elicit sustained changes on "sitting less and moving more".

Self-reported sitting time and physical activity: interactive associations with mental well-being and productivity in office employees

Background: Little is known about how sitting time, alone or in combination with markers of physical activity (PA), influences mental well-being and work productivity. Given the need to develop workplace PA interventions that target employees' health related efficiency outcomes; this study examined the associations between self-reported sitting time, PA, mental well-being and work productivity in office employees. Methods: Descriptive cross-sectional study. Spanish university office employees (n = 557) completed a survey measuring socio-demographics, total and domain specific (work and travel) self-reported sitting time, PA (International Physical Activity Questionnaire short version), mental well-being (Warwick-Edinburg Mental Well-Being Scale) and work productivity (Work Limitations Questionnaire). Multivariate linear regression analyses determined associations between the main variables adjusted for gender, age, body mass index and occupation. PA levels (low, moderate and high) were introduced into the model to examine interactive associations. Results: Higher volumes of PA were related to higher mental well-being, work productivity and spending less time sitting at work, throughout the working day and travelling during the week, including the weekends (p < 0.05). Greater levels of sitting during weekends was associated with lower mental well-being (p < 0.05). Similarly, more sitting while travelling at weekends was linked to lower work productivity (p < 0.05). In highly active employees, higher sitting times on work days and occupational sitting were associated with decreased mental well-being (p < 0.05). Higher sitting times while travelling on weekend days was also linked to lower work productivity in the highly active (p < 0.05). No significant associations were observed in low active employees. Conclusions: Employees' PA levels exerts different influences on the associations between sitting time, mental well-being and work productivity. The specific associations and the broad sweep of evidence in the current study suggest that workplace PA strategies to improve the mental well-being and productivity of all employees should focus on reducing sitting time alongside efforts to increase PA.