906 resultados para surface electronic phenomena (work function, surface potential, surface states. etc.)


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Esta dissertação apresenta os principais aspectos da Teoria dos Jogos, mostrando sua aplicação como instrumento analítico na Gestão de Pessoas no que diz respeito à variável salário. Considera a organização e o trabalhador como conceitos gerais, sem identificar o setor de atuação, ramo de atividade, classificação jurídica em função do seu faturamento, total de empregados ou participação de mercado dessa organização. Da mesma forma o conceito trabalhador não recebe qualquer identificação em relação ao setor de atividade onde trabalha, função, salário ou formação profissional. A organização é toda estrutura que gera bens e serviços para a sociedade e o trabalhador é todo elemento que emprega sua força de trabalho na produção de bens e serviços. Os objetivos estabelecidos para este estudo são: identificar as possibilidades de aplicação da Teoria dos Jogos na Gestão de Pessoas considerando a variável salário como elemento de conflito entre a organização e o trabalhador; mostrar se a forma de representação extensiva é mais apropriada ou não para analisar o cenário de embate na decisão de contratar ou não o trabalhador ou pagar mais ou menos salário e a existência do Equilíbrio de Nash. A metodologia qualitativa com apoio bibliográfico e documental caracteriza esta pesquisa qualitativa quanto a metodologia de pesquisa. Os métodos qualitativos contribuem para interpretar fenômenos do cotidiano, podendo ser composto por dados simbólicos situados em determinado contexto. A pesquisa documental é uma contribuição importante ao estudo do tema proposto, já que a pesquisa qualitativa não é uma proposta rigidamente estruturada e isto permite que o pesquisador use a imaginação e criatividade para atingir o objetivo. Os resultados obtidos pela pesquisa dão conta de que é possível a aplicação da Teoria dos Jogos na Gestão de Pessoas considerando o embate entre os jogadores (o trabalhador e a organização) em torno do salário, discutido no capítulo 4 nas representações da matriz de payoff de um jogo estratégico e nas figuras 9,10,11,e 16. A representação na forma extensiva, outro objetivo, indicando os payoffs entre duas decisões centrais representadas por X = flexibilização com renúncia dos direitos pelos trabalhadores e Y = flexibilização/adaptação/negociação, conforme figura 16. O gestor de pessoas percebe as estratégias existentes para a organização e trabalhador para a tomada de decisão, ao mesmo tempo em que pode avaliar a situação que esteja vivendo e fazer simulações em busca de novas propostas. Por fim, o Equilíbrio de Nash para a aplicação na Gestão de Pessoas é discutido no item 4.1.3, sendo possível verificar que tanto o trabalhador como a organização podem chegar a uma decisão favorável para ambos e manter seus objetivos pretendidos inicialmente. Na figura 17, esse equilíbrio é apresentado depois da tomada de decisão do trabalhador pela proposta feita pela organização na sequência O2 e o trabalhador ficou com o ramo de sequência T2 com o valor de 20 moedas. A potencialidade da Teoria dos Jogos na Gestão de Pessoas está no fato de que quem atua em uma organização compartilha resultados bons ou ruins obtidos pelas escolhas alheias, individuais e construídas coletivamente.

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Esta dissertação apresenta os principais aspectos da Teoria dos Jogos, mostrando sua aplicação como instrumento analítico na Gestão de Pessoas no que diz respeito à variável salário. Considera a organização e o trabalhador como conceitos gerais, sem identificar o setor de atuação, ramo de atividade, classificação jurídica em função do seu faturamento, total de empregados ou participação de mercado dessa organização. Da mesma forma o conceito trabalhador não recebe qualquer identificação em relação ao setor de atividade onde trabalha, função, salário ou formação profissional. A organização é toda estrutura que gera bens e serviços para a sociedade e o trabalhador é todo elemento que emprega sua força de trabalho na produção de bens e serviços. Os objetivos estabelecidos para este estudo são: identificar as possibilidades de aplicação da Teoria dos Jogos na Gestão de Pessoas considerando a variável salário como elemento de conflito entre a organização e o trabalhador; mostrar se a forma de representação extensiva é mais apropriada ou não para analisar o cenário de embate na decisão de contratar ou não o trabalhador ou pagar mais ou menos salário e a existência do Equilíbrio de Nash. A metodologia qualitativa com apoio bibliográfico e documental caracteriza esta pesquisa qualitativa quanto a metodologia de pesquisa. Os métodos qualitativos contribuem para interpretar fenômenos do cotidiano, podendo ser composto por dados simbólicos situados em determinado contexto. A pesquisa documental é uma contribuição importante ao estudo do tema proposto, já que a pesquisa qualitativa não é uma proposta rigidamente estruturada e isto permite que o pesquisador use a imaginação e criatividade para atingir o objetivo. Os resultados obtidos pela pesquisa dão conta de que é possível a aplicação da Teoria dos Jogos na Gestão de Pessoas considerando o embate entre os jogadores (o trabalhador e a organização) em torno do salário, conforme pode ser visto no capítulo 4 nas representações da matriz de payoff de um jogo estratégico e nas figuras 9,10,11,e 16. A representação na forma extensiva, constitui outro objetivo, indicando os payoffs entre duas decisões centrais representadas por X = flexibilização com renúncia dos direitos pelos trabalhadores e Y = flexibilização/adaptação/negociação, conforme figura 16. Ao analisar a figura, o gestor de pessoas percebe as estratégias existentes para a organização e trabalhador para a tomada de decisão, ao mesmo tempo em que pode avaliar a situação que esteja vivendo e fazer simulações em busca de novas propostas. Por fim, o Equilíbrio de Nash para a aplicação na Gestão de Pessoas é discutido no item 4.1.3, sendo possível verificar que tanto o trabalhador como a organização podem chegar a uma decisão favorável para ambos e manter seus objetivos pretendidos inicialmente. Na figura 17, esse equilíbrio é apresentado depois da tomada de decisão do trabalhador pela proposta feita pela organização na sequência O2 e o trabalhador ficou com o ramo de sequência T2 com o valor de 20 moedas. A potencialidade da Teoria dos Jogos na Gestão de Pessoas surge do fato de que quem atua em uma organização compartilha resultados bons ou ruins obtidos pelas escolhas alheias, escolhas individuais e pelas escolhas construídas coletivamente. Quando o trabalhador resolve produzir menos, a empresa sofre com a perda do lucro gerado pelo ritmo mais lento de trabalho. Para mudar esse quadro, a empresa toma a decisão de aumentar o salário e o trabalhador por sua vez desenvolve a tarefa com maior velocidade e em maior quantidade e ela pode retomar o seu lucro. Nesses jogos há cobranças de desempenho, exigência para atingir metas, pressões, conflitos com clientes e lideranças. Logo, a Teoria dos Jogos pode ser aplicada como instrumento para o gestor de Pessoas avaliar a situação vivida para a tomada de decisão que resolva a situação de embate.

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Brain-computer interfaces (BCI) have the potential to restore communication or control abilities in individuals with severe neuromuscular limitations, such as those with amyotrophic lateral sclerosis (ALS). The role of a BCI is to extract and decode relevant information that conveys a user's intent directly from brain electro-physiological signals and translate this information into executable commands to control external devices. However, the BCI decision-making process is error-prone due to noisy electro-physiological data, representing the classic problem of efficiently transmitting and receiving information via a noisy communication channel.

This research focuses on P300-based BCIs which rely predominantly on event-related potentials (ERP) that are elicited as a function of a user's uncertainty regarding stimulus events, in either an acoustic or a visual oddball recognition task. The P300-based BCI system enables users to communicate messages from a set of choices by selecting a target character or icon that conveys a desired intent or action. P300-based BCIs have been widely researched as a communication alternative, especially in individuals with ALS who represent a target BCI user population. For the P300-based BCI, repeated data measurements are required to enhance the low signal-to-noise ratio of the elicited ERPs embedded in electroencephalography (EEG) data, in order to improve the accuracy of the target character estimation process. As a result, BCIs have relatively slower speeds when compared to other commercial assistive communication devices, and this limits BCI adoption by their target user population. The goal of this research is to develop algorithms that take into account the physical limitations of the target BCI population to improve the efficiency of ERP-based spellers for real-world communication.

In this work, it is hypothesised that building adaptive capabilities into the BCI framework can potentially give the BCI system the flexibility to improve performance by adjusting system parameters in response to changing user inputs. The research in this work addresses three potential areas for improvement within the P300 speller framework: information optimisation, target character estimation and error correction. The visual interface and its operation control the method by which the ERPs are elicited through the presentation of stimulus events. The parameters of the stimulus presentation paradigm can be modified to modulate and enhance the elicited ERPs. A new stimulus presentation paradigm is developed in order to maximise the information content that is presented to the user by tuning stimulus paradigm parameters to positively affect performance. Internally, the BCI system determines the amount of data to collect and the method by which these data are processed to estimate the user's target character. Algorithms that exploit language information are developed to enhance the target character estimation process and to correct erroneous BCI selections. In addition, a new model-based method to predict BCI performance is developed, an approach which is independent of stimulus presentation paradigm and accounts for dynamic data collection. The studies presented in this work provide evidence that the proposed methods for incorporating adaptive strategies in the three areas have the potential to significantly improve BCI communication rates, and the proposed method for predicting BCI performance provides a reliable means to pre-assess BCI performance without extensive online testing.

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Two-dimensional (2D) materials have generated great interest in the last few years as a new toolbox for electronics. This family of materials includes, among others, metallic graphene, semiconducting transition metal dichalcogenides (such as MoS2) and insulating Boron Nitride. These materials and their heterostructures offer excellent mechanical flexibility, optical transparency and favorable transport properties for realizing electronic, sensing and optical systems on arbitrary surfaces. In this work, we develop several etch stop layer technologies that allow the fabrication of complex 2D devices and present for the first time the large scale integration of graphene with molybdenum disulfide (MoS2) , both grown using the fully scalable CVD technique. Transistor devices and logic circuits with MoS2 channel and graphene as contacts and interconnects are constructed and show high performances. In addition, the graphene/MoS2 heterojunction contact has been systematically compared with MoS2-metal junctions experimentally and studied using density functional theory. The tunability of the graphene work function significantly improves the ohmic contact to MoS2. These high-performance large-scale devices and circuits based on 2D heterostructure pave the way for practical flexible transparent electronics in the future. The authors acknowledge financial support from the Office of Naval Research (ONR) Young Investigator Program, the ONR GATE MURI program, and the Army Research Laboratory. This research has made use of the MI.

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Staphylococcus aureus are among the most common species isolated from bovine mastitis. The pathogenesis of this bacterium is facilitated by a number of virulence factors, including the ability to adhere to abiotic surfaces and/or host tissues often leading to biofilms' formation. From the clinical perspective, the most important feature of Staphytococcus species' biofilms is their high tolerance to the conventional antimicrobial therapy. So, the increasing number of bovine mastitis and the higher levels of Staphylococcus species resistance to traditional antimicrobial agents are considered an important alert for the necessity to focus the future research on identification and development of new strategies to combat S. aureus mastitis. RecenUy, the interest in natural alternatives based on plant extracts has been rising. In add~ion to their health benefits, their antimicrobial potential has been increasingly reported. Taking this into consideration, the evaluation of hydromethanolic extracts of E. globulus against S. aureus biofilms was tested and compared with penicillin, one of the antibiotics most often used in the treatment of cattle infections. All mastitis' isolates tested were good-biofilm producers. As expected penicillin has demonstrated poor activity against S. aureus biofilms (<1 log reduction). However, E. globulus Labill was bactericidal, promoting a biofilm cell reduction of 2-3 log. Therefore, the present work showed the potential antimicrobial activity of E. g/obulus against S. aureus from bovine mastitis, namely in biofilm mode of growth and drew attention to its promising use as an alternative to penicillin.

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We synthesized nanoscale TiO2-RuO2 alloys by atomic layer deposition (ALD) that possess a high work function and are highly conductive. As such, they function as good Schottky contacts to extract photogenerated holes from n-type silicon while simultaneously interfacing with water oxidation catalysts. The ratio of TiO2 to RuO2 can be precisely controlled by the number of ALD cycles for each precursor. Increasing the composition above 16% Ru sets the electronic conductivity and the metal work function. No significant Ohmic loss for hole transport is measured as film thickness increases from 3 to 45 nm for alloy compositions >= 16% Ru. Silicon photoanodes with a 2 nm SiO2 layer that are coated by these alloy Schottky contacts having compositions in the range of 13-46% Ru exhibit average photovoltages of 525 mV, with a maximum photovoltage of 570 mV achieved. Depositing TiO2-RuO2 alloys on nSi sets a high effective work function for the Schottky junction with the semiconductor substrate, thus generating a large photovoltage that is isolated from the properties of an overlying oxygen evolution catalyst or protection layer.

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The interface formed between Cu3BiS3 thin films and the buffer layer is a potentially limiting factor to the performance of solar cells based on Al/Cu3BiS3/buffer heterojunctions. The buffer layers of ZnS and In2S3 were grown by coevaporation, and tested as an alternative to the traditional CdS deposited by chemical bath deposition. From the Kelvin probe force microscopy measurements, we found the values of the work function of ZnS, In2S3, and CdS, layers deposited into Cu3BiS3. Additionally, different electronic activity was found for different grain boundaries (GBs), from studies under illumination, we also found the net doping concentration and the density of charged GB states for Cu3BiS3 and Cu3BiS3/CdS.

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Glioblastoma is the most malignant brain tumor in adults. The standard care of treatment is tumor resection, radiotherapy, and chemotherapy. Despite these invasive therapeutic approaches, glioblastoma prognosis remains unchanged. Therefore, a better understanding of the molecular mechanisms driving tumor transformation is needed to uncover novel therapeutic strategies. Several studies have shown the significance of lipid signaling and phospholipases (PLCs) in the regulation of different mechanisms in the central nervous system as well as in glioblastoma pathogenesis. This work suggests a potential role of PLCβ1 in the maintenance of a less aggressive phenotype of the tumor. Indeed, it was demonstrated that PLCβ1 gene was relatively less expressed in glioblastoma patients compared to their healthy/low-grade counterparts. Moreover, PLCβ1 silencing, in both immortalized and primary cell lines, led to increased cell migration, invasion, proliferation, cell survival and induced the upregulation of mesenchymal markers and metalloproteinases. Moreover, PLCγ1, another abundant PLC isoform in the brain, has been identified as a key element for the aggressiveness of glioblastoma. Data collected on patients’ biopsies and engineered cell models, suggested a strong correlation between PLCγ1 expression level and the acquisition of a more aggressive tumor phenotype. Finally, this trend was further probed using patient-derived glioblastoma stem cells (GSCs), which are a specific tumor population that drives aggressiveness, resistance, and recurrence in glioblastoma. GSCs analysis on the transcriptomic profiles confirmed that PLCγ1 downregulation modulated positively the activation of pathways that negatively regulate cell motility and migration and led to a decreased expression of genes involved in cancer development and progression. Taken together, these data highlight the importance of further investigating phospholipases as potential prognostic biomarkers and targets in the development of new therapeutic strategies for glioblastoma.

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The [Ru3O(Ac)6(py)2(CH3OH)]+ cluster provides an effective electrocatalytic species for the oxidation of methanol under mild conditions. This complex exhibits characteristic electrochemical waves at -1.02, 0.15 and 1.18 V, associated with the Ru3III,II,II/Ru3III,III,II/Ru 3III,III,III /Ru3IV,III,III successive redox couples, respectively. Above 1.7 V, formation of two RuIV centers enhances the 2-electron oxidation of the methanol ligand yielding formaldehyde, in agreement with the theoretical evolution of the HOMO levels as a function of the oxidation states. This work illustrates an important strategy to improve the efficiency of the oxidation catalysis, by using a multicentered redox catalyst and accessing its multiple higher oxidation states.

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Ethanol oxidation has been studied on stepped platinum single crystal electrodes in acid media using electrochemical and Fourier transform infrared (FTIR) techniques. The electrodes used belong to two different series of stepped surfaces: those having (111) terraces with (100) monoatomic steps and those with (111) terraces with (110) monoatomic steps. The behaviors of the two series of stepped surfaces for the oxidation of ethanol are very different. On the one hand, the presence of (100) steps on the (111) terraces provides no significant enhancement of the activity of the surfaces. On the other hand, (110) steps have a double effect on the ethanol oxidation reaction. At potentials below 0.7 V, the step catalyzes the C-C bond cleavage and also the oxidation of the adsorbed CO species formed. At higher potentials, the step is not only able to break the C-C bond, but also to catalyze the oxidation of ethanol to acetic acid and acetaldehyde. The highest catalytic activity from voltammetry for ethanol oxidation was obtained with the Pt(554) electrode.

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This work had as its main objective to contribute to the development of a biological detoxification of hemicellulose hydrolysates obtained from different biomass plants using Issatchenkia occidentalis CCTCC M 206097 yeast. Tests with hemicellulosic hydrolysate of sugarcane bagasse in different concentrations were carried out to evaluate the influence of the hydrolysate concentration on the inhibitory compounds removal from the sugarcane bagasse hydrolysate, without reduction of sugar concentration. The highest reduction values of inhibitors concentration and less sugar losses were observed when the fivefold concentrated hydrolysate was treated by the evaluated yeast. In these experiments it was found that the high sugar concentrations favored lower sugar consumption by the yeast. The highest concentration reduction of syringaldehyde (66.67%), ferulic acid (73.33%), furfural (62%), and 5-HMF (85%) was observed when the concentrated hydrolysate was detoxified by using this yeast strain after 24 h of experimentation. The results obtained in this work showed the potential of the yeast Issatchenkia occidentalis CCTCC M 206097 as detoxification agent of hemicellulosic hydrolysate of different biomass plants.

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Time availability is a key concept in relation to volunteering, leading to organisations and governments targeting those outside paid work as a potential source of volunteers. It may be that factors such as a growth in female participation in the labour market and an increase in work hours will lead to more people saying they are simply too busy to volunteer This paper discusses how social and economic change, such as changing work patterns, are impacting on time availability. Using the 1997 ABS Time Use data, it identifies a predictive model of spare time by looking at demographic, life stage and employment related variables. Results confirm that those outside paid work, particularly the young, males and those without partners or children, are the groups most likely to have time to spare. These groups do not currently report high rates of volunteering. The paper concludes by questioning the premise that people will volunteer simply because they have time to spare. This is just one component of a range of motivations and factors that influence the decision to volunteer.

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Drosophila Fallen, 1823 (Diptera, Drosophilidae) is for long a well-established model organism for genetics and evolutionary research. The ecology of these flies, however, has only recently been better studied. Recent papers show that Drosophila assemblies can be used as bioindicators of forested environment degradation. In this work the bioindicator potential of drosophilids was evaluated in a naturally opened environment, a coastal strand-forest (restinga). Data from nine consecutive seasonal collections revealed strong temporal fluctuation pattern of the majority of Drosophila species groups. Drosophila willistoni group was more abundant at autumns, whereas D. cardini and D. tripunctata groups were, respectively, expressive at winters and springs, and D. repleta group at both seasons. The exotic species D. simulans Sturtevant, 1919 (from D. melanogaster group) and Zaprionus indianus Gupta, 1970 were most abundant at summers. Overall, the assemblage structure did not show the same characteristics of forested or urban environments, but was similar to the forests at winters and to cities at summers. This raises the question that this locality may already been under urbanization impact. Also, this can be interpreted as an easily invaded site for exotic species, what might lead to biotic homogenization and therefore can put in check the usage of drosophilid assemblages as bioindicators at open environments.

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Background: There is little, though growing, interest in the research area of attitudes held among physicians towards disclosing the diagnosis of dementia and Alzheimer`s disease (AD), or the current practice on AD disclosure. This study aimed to investigate the practice and attitudes of specialized physicians towards AD diagnosis disclosure in Brazil. Methods: A questionnaire was devised to survey the current practice and attitudes regarding diagnosis disclosure of AD in Brazil and sent to specialized physicians (170 geriatricians, 300 neurologists and 500 psychiatrists) by electronic mail. Results: From 970 potential respondents, 181 physicians who usually attend AD patients returned the questionnaire. There were no significant differences between the three specialties regarding the frequency with which they informed patients of their AD diagnosis (p = 0.17). The results revealed that only 44.8% of the physicians would regularly inform the patient of the diagnosis, although 85.6% of these use clear terminology. Despite their usual practice, 76.8% would want to know their diagnosis if they themselves were affected by AD. Conclusions: Disclosure of AD diagnosis is not common among specialized physicians in Brazil and different factors are involved. In the clinical context, discussion on advantages of diagnosis disclosure can be useful for improving the care of AD patients and their families.

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This paper reviews current research and contemporary theories of subcortical participation in the motor control of speech production and language processing. As a necessary precursor to the discussion of the functional roles of the basal ganglia and thalamus, the neuroanatomy of the basal ganglial-thalamocortical circuitry is described. Contemporary models of hypokinetic and hyperkinetic movement disorders based on recent neuroanatomical descriptions of the multi-segmented circuits that characterise basal ganglion anatomy are described. Reported effects of surgically induced lesions in the globus pallidus and thalamus on speech production are reviewed. In addition, contemporary models proposed to explain the possible contribution of various subcortical structures to language processing are described and discussed in the context of evidence gained from observation of the effects of circumscribed surgically induced lesions in the basal ganglia and thalamus on language function. The potential of studies based on examination of the speech/language outcomes of patients undergoing pallidotomy and thalamotomy to further inform the debate relating to the role of subcortical structures in speech motor control and language processing is highlighted. Copyright (C) 2001 S. Karger AG, Basel.