951 resultados para High-work-function metal
Resumo:
A method employing chitosan as complexant agent in the removal of copper(II) ions generally present in the Brazilian cachaça samples is herein proposed. The efficiency of this method is attributed to its high capacity of metal cations adsorption, mainly due to presence of hydroxyl and amine groups that can serve as chelating sites. The removal of copper(II) ions from this alcoholic beverage was efficient employing either in column and batch system. The analysis were carried out employing the flame atomic absorption spectrometry and the remaining copper(II) concentrations in the treated cachaça were lower than LOD of FAAS technique.
Resumo:
Yritys edistää menestymistään oikeanlaisen johtamisen sekä työn imua omaavan henkilöstön kautta. Johtajuus käsittää asioiden- ja henkilöiden johtamisen sekä valmentamisen. Tutkimus etenee johtamisen teemasta valmentamisen ja motivaation kautta työn imun kokemuksiin. Henkilöjohtaminen tarkoittaa lähes kokonaan esimiehen käyttäytymistä, mikä on koko ajan tarkkailun alla, halusi hän sitä tai ei. Leader -johtaja tekee organisaatiossa muutosta. Valmentaminen on erinomainen tapa päästä lähelle työntekijöitä ja aikaansaada oikeansuuntaista ja haluttua kehitystä. Valmentamisen yksi tärkeimmistä työkaluista on avoimet kysymykset, joiden avulla esimies pystyy auttamaan valmennettavaa löytämään omat vahvuutensa, kehittämiskohteensa sekä motivaationlähteensä. Työn imu on yksi työhyvinvoinnin käsitteistä. Työn imulla tarkoitetaan myönteistä tunne- ja motivaatiotäyttymyksen tilaa, jota luonnehtivat tarmokkuus (vigor), omistautuminen (dedication) ja uppoutuminen (absorption). Se on pitkäkestoinen ja kaikkialle levittyvä tila, joka ei kohdistu mihinkään yhteen tiettyyn asiaan, tapahtumaan, yksilöön tai käyttäytymiseen.
Resumo:
Notre recherche a comme objectif de déterminer si le statut d’immigrant agit comme modérateur de la relation entre l’état de faible revenu et ses déterminants au Canada. Elle est basée sur les données du Recensement de 2006. Notre étude cherche à comprendre s'il existe des différences selon l'appartenance à la population immigrante ou à la population native quant à la probabilité d’être dans un état de faible revenu. Également, nous avons accordé une attention particulière à la région d'origine des immigrants. Nos résultats soutiennent qu'effectivement l'effet des déterminants retenus sur la probabilité de connaître l’état de faible revenu varie entre les immigrants et les natifs ainsi qu’entre les immigrants selon leur région d'origine. C'est surtout chez les immigrants issus des pays non traditionnels que l'écart dans l'effet des variables est le plus marqué et ce, par rapport aux natifs. Les immigrants issus des pays traditionnels se trouvent dans une situation intermédiaire, soit entre les deux groupes. Par exemple, l'éducation a un effet négatif moins important sur la probabilité d’être dans un état de faible revenu chez les immigrants originaires des pays non traditionnels comparativement aux natifs et aux immigrants originaires des pays traditionnels. Par contre, l’appartenance à une minorité visible, le statut d’étudiant et l’intensité de travail produisent un effet plus important sur la probabilité en question chez les immigrants issus des pays non traditionnels comparativement aux autres groupes. La connaissance des langues officielles du Canada produit un effet négatif bien plus important dans le cas des immigrants issus des pays non traditionnels. C’est surtout les immigrants bilingues qui sont les moins exposés à l’état de faible revenu, alors que ceux qui ne parlent aucune langue officielle du Canada sont les plus touchés. Nous retrouvons les mêmes effets chez les immigrants issus des pays traditionnels, mais dans une moindre mesure. En somme, cette étude apporte des nouvelles connaissances dans le domaine et permet d’arriver à une meilleure compréhension de l’état de faible revenu chez les personnes âgées de 15 ans et plus au Canada.
Resumo:
Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal
Resumo:
This report explores how recurrent neural networks can be exploited for learning high-dimensional mappings. Since recurrent networks are as powerful as Turing machines, an interesting question is how recurrent networks can be used to simplify the problem of learning from examples. The main problem with learning high-dimensional functions is the curse of dimensionality which roughly states that the number of examples needed to learn a function increases exponentially with input dimension. This thesis proposes a way of avoiding this problem by using a recurrent network to decompose a high-dimensional function into many lower dimensional functions connected in a feedback loop.
Resumo:
El trabajo exige en el individuo una serie de esfuerzos fisiológicos que implican el uso de los componentes del sistema osteo-muscular, cardiovascular y metabólico, definiéndose así la carga física de trabajo. El objetivo fue determinar la respuesta fisiológica a la exposición a calor y carga física en trabajadores operadores de hornos de coquería. El estudio se realizó en once trabajadores expuestos a carga física y a calor en hornos de coquería. Se realizó la medición de capacidad máxima de trabajo (VO2máx), medición de consumo calórico y respuesta cardiovascular a la carga térmica y medición de niveles de hidratación. No obstante de su alta capacidad de trabajo y desempeño físico de los horneros, el trabajo de deshorne se califica como extremadamente duro muy duro o intenso. Se recomienda intervenir tecnológicamente el sistema de trabajo de deshorne mediante mecanización de las tareas.
Resumo:
Introducción: En Colombia, no existe una herramienta para cuantificar el grado de congestión de los servicios de urgencias que sea aplicable a su realidad. Por esta razón, este trabajo busca determinar si la escala NEDOCS es una herramienta válida para medir el grado de congestión en este medio. Métodos: Se calculó la escala durante un período de tres semanas, durante 6 veces en el día a la misma hora en las tres instituciones. Para la validación, se comparó la escala NEDOCS contra dos escalas tipo Likert de 6 preguntas. Además, se describió el porcentaje de la demanda no atendida y del número de quejas. Resultados: Para la escala, la variabilidad se explica en 88 %. Por otro lado, la correlación entre la severidad en la congestión de los últimos 3 ítems de la escala con las opiniones subjetivas fue directa y significativa (r = 1,000., p < 0.000). Se obtuvo una correspondencia significativa con las siguientes variables: a) disponibilidad de camas (r = 0.7, p < 0.001); b) promedio de tiempo de espera, (r = 0,56, p < 0.021). Discusión: Dado que no existe gold standard, las mediciones de la escala en comparación con las opiniones del personal arrojan que la escala NEDOCS aplicada en los servicios de urgencias colombianos es útil para medir congestión. Se observó como fenómeno especial que el personal se encuentra acostumbrado a vivir con la congestión, por lo cual el personal considera como congestión del servicio los momentos de alto stress laboral.
Resumo:
Most parameterizations for precipitating convection in use today are bulk schemes, in which an ensemble of cumulus elements with different properties is modelled as a single, representative entraining-detraining plume. We review the underpinning mathematical model for such parameterizations, in particular by comparing it with spectral models in which elements are not combined into the representative plume. The chief merit of a bulk model is that the representative plume can be described by an equation set with the same structure as that which describes each element in a spectral model. The equivalence relies on an ansatz for detrained condensate introduced by Yanai et al. (1973) and on a simplified microphysics. There are also conceptual differences in the closure of bulk and spectral parameterizations. In particular, we show that the convective quasi-equilibrium closure of Arakawa and Schubert (1974) for spectral parameterizations cannot be carried over to a bulk parameterization in a straightforward way. Quasi-equilibrium of the cloud work function assumes a timescale separation between a slow forcing process and a rapid convective response. But, for the natural bulk analogue to the cloud-work function (the dilute CAPE), the relevant forcing is characterised by a different timescale, and so its quasi-equilibrium entails a different physical constraint. Closures of bulk parameterization that use the non-entraining parcel value of CAPE do not suffer from this timescale issue. However, the Yanai et al. (1973) ansatz must be invoked as a necessary ingredient of those closures.
Resumo:
A simple self–contained theory is proposed for describing life cycles of convective systems as a discharge–recharge process. A closed description is derived for the dynamics of an ensemble of convective plumes based on an energy cycle. The system consists of prognostic equations for the cloud work function and the convective kinetic energy. The system can be closed by intro ducing a functional relationship between the convective kinetic energy and the cloud–base mass flux. The behaviour of this system is considered under a bulk simplification. Previous cloud–resolving mo delling as well as bulk statistical theories for ensemble convective systems suggest that a plausible relationship would be to assume that the convective kinetic energy is linearly proportional to the cloud–base mass flux. As a result, the system reduces to a nonlinear dynamical system with two dependent variables, the cloud–base mass flux and the cloud work function. The fully nonlinear solution of this system always represents a periodic cycle regardless of the initial condition under constant large–scale forcing. Importantly, the inclusion of energy dissipation in this model does not in itself lead the system to an equilibrium.
Resumo:
A generalization of Arakawa and Schubert's convective quasi-equilibrium principle is presented for a closure formulation of mass-flux convection parameterization. The original principle is based on the budget of the cloud work function. This principle is generalized by considering the budget for a vertical integral of an arbitrary convection-related quantity. The closure formulation includes Arakawa and Schubert's quasi-equilibrium, as well as both CAPE and moisture closures as special cases. The formulation also includes new possibilities for considering vertical integrals that are dependent on convective-scale variables, such as the moisture within convection. The generalized convective quasi-equilibrium is defined by a balance between large-scale forcing and convective response for a given vertically-integrated quantity. The latter takes the form of a convolution of a kernel matrix and a mass-flux spectrum, as in the original convective quasi-equilibrium. The kernel reduces to a scalar when either a bulk formulation is adopted, or only large-scale variables are considered within the vertical integral. Various physical implications of the generalized closure are discussed. These include the possibility that precipitation might be considered as a potentially-significant contribution to the large-scale forcing. Two dicta are proposed as guiding physical principles for the specifying a suitable vertically-integrated quantity.
Resumo:
Introduction Researchers have, for decades, contributed to an increased collective understanding of the physiological demands in cross-country skiing; however, almost all of these studies have used either non-elite subjects and/or performances that emulate cross-country skiing. To establish the physiological demands of cross-country skiing, it is important to relate the investigated physiological variables to the competitive performance of elite skiers. The overall aim of this doctoral thesis was, therefore, to investigate the external validity of physiological test variables to determine the physiological demands in competitive elite cross-country skiing. Methods The subjects in Study I – IV were elite male (I – III) and female (III – IV) cross-country skiers. In all studies, the relationship between test variables (general and ski-specific) and competitive performances (i.e. the results from competitions or the overall ski-ranking points of the International Ski Federation (FIS) for sprint (FISsprint) and distance (FISdist) races) were analysed. Test variables reflecting the subject’s general strength, upper-body and whole-body oxygen uptake, oxygen uptake and work intensity at the lactate threshold, mean upper-body power, lean mass, and maximal double-poling speed were investigated. Results The ability to maintain a high work rate without accumulating lactate is an indicator of distance performance, independent of sex (I, IV). Independent of sex, high oxygen uptake in whole-body and upper-body exercise was important for both sprint (II, IV) and distance (I, IV) performance. The maximal double-poling speed and 60-s double-poling mean power output were indicators of sprint (IV) and distance performance (I), respectively. Lean mass was correlated with distance performance for women (III), whereas correlations were found between lean mass and sprint performance among both male and female skiers (III). Moreover, no correlations between distance performance and test variables were derived from tests of knee-extension peak torque, vertical jumps, or double poling on a ski-ergometer with 20-s and 360-s durations (I), whereas gross efficiency while treadmill roller skiing showed no correlation with either distance or sprint performance in cross-country skiing (IV). Conclusion The results in this thesis show that, depending on discipline and sex, maximal and peak oxygen uptake, work intensity at the lactate threshold, lean mass, double-poling mean power output, and double-poling maximal speed are all externally valid physiological test variables for evaluation of performance capability among elite cross-country skiers; however, to optimally indicate performance capability different test-variable expressions should be used; in general, the absolute expression appears to be a better indicator of competitive sprint performance whereas the influence of body mass should be considered when evaluating competitive distance performance capability of elite cross-country skiers.
Resumo:
This study looked for identify the causes and the effects of fear in the individuals within the organizational context. The procedure for data collection consisted in a questionnaire divided in two stages, and applied in 76 individuals. The first stage consisted in a words evocation test and the second, as a complementary mode, was composed by four open questions. The theory of social representations and the central nucleus theory were the foundations of the data analysis of the words evocation test. The processing of the open questions was consisted in an interpretative analysis, based in the presented theoretical referencial and supported by the respondents social representation of fear. In the enterprises context, different causes and effects of fear had been found in the inserted individuals. However, in its majority, it was identified that the biggest individuals fears are the unemployment, the threats, punishments, the unstable and unsafe environments of work, the unfair competition, the collusions, sabotages, tricks, the incapacity to do its work¿s tasks and the abusive increase of the work load. On the other hand, about the fear¿s effects, there is a frequent physiological and psychological instability when they had been submitted in high work loads. The fear is an excellent creativity, innovation and aptitude repressor, and it is capable to generate disgusts, frustrations, defensive postures, standstills and to increase the jobs navigability.
Resumo:
Neste trabalho é proposto um novo algoritmo online para o resolver o Problema dos k-Servos (PKS). O desempenho desta solução é comparado com o de outros algoritmos existentes na literatura, a saber, os algoritmos Harmonic e Work Function, que mostraram ser competitivos, tornando-os parâmetros de comparação significativos. Um algoritmo que apresente desempenho eficiente em relação aos mesmos tende a ser competitivo também, devendo, obviamente, se provar o referido fato. Tal prova, entretanto, foge aos objetivos do presente trabalho. O algoritmo apresentado para a solução do PKS é baseado em técnicas de aprendizagem por reforço. Para tanto, o problema foi modelado como um processo de decisão em múltiplas etapas, ao qual é aplicado o algoritmo Q-Learning, um dos métodos de solução mais populares para o estabelecimento de políticas ótimas neste tipo de problema de decisão. Entretanto, deve-se observar que a dimensão da estrutura de armazenamento utilizada pela aprendizagem por reforço para se obter a política ótima cresce em função do número de estados e de ações, que por sua vez é proporcional ao número n de nós e k de servos. Ao se analisar esse crescimento (matematicamente, ) percebe-se que o mesmo ocorre de maneira exponencial, limitando a aplicação do método a problemas de menor porte, onde o número de nós e de servos é reduzido. Este problema, denominado maldição da dimensionalidade, foi introduzido por Belmann e implica na impossibilidade de execução de um algoritmo para certas instâncias de um problema pelo esgotamento de recursos computacionais para obtenção de sua saída. De modo a evitar que a solução proposta, baseada exclusivamente na aprendizagem por reforço, seja restrita a aplicações de menor porte, propõe-se uma solução alternativa para problemas mais realistas, que envolvam um número maior de nós e de servos. Esta solução alternativa é hierarquizada e utiliza dois métodos de solução do PKS: a aprendizagem por reforço, aplicada a um número reduzido de nós obtidos a partir de um processo de agregação, e um método guloso, aplicado aos subconjuntos de nós resultantes do processo de agregação, onde o critério de escolha do agendamento dos servos é baseado na menor distância ao local de demanda
Resumo:
The structural and electronic properties of bulk and both oxidized and reduced SnO2(110) surfaces as well as the adsorption process of O-2 on the reduced surface have been investigated by periodic DFT calculations at B3LYP level. The lattice parameters, charge distribution, density of states and band structure are reported for the bulk and surfaces. Surface relaxation effects have been explicitly taken into account by optimizing slab models of nine and seven atomic layers representing the oxidized and reduced surfaces, respectively. The conductivity behavior of the reduced SnO2(110) surface is explained by a distribution of the electrons in the electronic states in the band gap induced by oxygen vacancies. Three types of adsorption approaches of O-2 on the four-fold tin at the reduced SuO(2)(110) surface have been considered. The most exothermic channel corresponds to the adsorption of O-2 parallel to the surface and to the four-fold tin row, and it is believed to be associated with the formation of a peroxo O-2(2-) species. The chemisorption of O-2 on reduced SnO2(110) surface causes a significant depopulation of states along the band gap and it is shown to trap the electrons in the chemisorbed complex producing an electron-depleted space-charge layer in the inner surface region of the material in agreement with some experimental evidences. (C) 2002 Elsevier B.V. B.V. All rights reserved.
Resumo:
Given the large existing biodiversity in the Brazilian coast, where many species are still little known, even under the nutritional aspect, and considering that bivalve molluscs are constituted by a natural resource of well accepted by the population, chose the bivalve Anadara notabilis, it was not found in the literature any nutritional or toxicological information about it and because its size is much larger than other species of mollusks commonly found in this region. Were studied moisture, ash, protein, macro and micro minerals, and metal ions of toxicological significance. All analytical determinations followed the standards of the Institute Adolfo Lutz. The protein determination was performed by the Kjeldahl method. All metal ions were determined by optical emission spectroscopy with inductively coupled plasma (ICP-OES) method described by USEPA 6010C. The results showed that Anadara notabilis can be introduced into food for human beings, in view of its mineral wealth. Noteworthy among the macronutrients phosphorus and magnesium showed that their values in mg / kg 918.7 and 586.7. With regard to micronutrients stand out with this iron 586.7 mg / kg and zinc with 12.31 mg / kg. Was not found high content of metal contaminants to this mollusc, which would prevent their use, only this chromium 0.7 mg / kg above the value established by Brazilian legislation. The results will certainly be very useful in future studies of nutrition and to build a table of chemical composition of Brazilian foods