TEM, XRD and AFM study of poly(o-ethoxyaniline) films: new evidence for the formation of conducting islands

The existence of conducting islands in polyaniline films has long been proposed in the literature, which would be consistent with conducting mechanisms based on hopping. Obtaining direct evidence of conducting islands, however, is not straightforward. In this paper, conducting islands were visualized in poly(o-ethoxyaniline) (POEA) films prepared at low pH, using Transmission Electron Microscopy (TEM) and atomic force spectroscopy (AFS). The size of the islands varied between 67 and 470 angstrom for a pH=3.0, with a larger average being obtained with AFS, probably due to the finite size effect of the atomic force microscopy tip. In AFS, the conducting islands were denoted by regions with repulsive forces due to the double-layer forces. On the basis of X-ray diffraction (XRD) patterns for POEA in the powder form, we infer that the conducting islands are crystalline, and therefore a POEA film is believed to consist of conducting islands dispersed in an insulating, amorphous matrix. From conductivity measurements we inferred the charge transport to be governed by a typical quasi-one dimensional variable range hopping (VRH) mechanism.

Evaluation of dental pulp repair using low level laser therapy (688 nm and 785 nm) morphologic study in capuchin monkeys

The aim of this study was to evaluate the hypothesis that low-level laser therapy (LLLT) 688 nm and 785 nm accelerate dentin barrier formation and repair process after traumatic pulp exposure. The sample consisted of 45 premolars of capuchin monkeys (Cebus apella) with pulp exposure Class V cavities. All premolars were treated with calcium hydroxide (Ca(OH)(2)), divided in groups of 15 teeth each, and analyzed on 7(th), 25(th), and 60(th) day. Group GI - only Ca(OH)(2), GIF- laser 688 nm, and GIII - laser 785 nm. Laser beam was used in single and punctual dose with the parameters: continuous, 688 nm and 785 nm wavelength, tip`s area of 0.00785 cm(2), power 50 mW, application time 20 s, dose 255 J/cm(2), energy 2 J. Teeth were capped with Ca(OH)(2), Ca(OH)(2) cement and restored with amalgam. All groups presented pulp repair. On 25(th) day the thickness of the formed dentin barrier was different between the groups GI and GII (p < 0.05) and between groups GI and GIII (p < 0.01). On 60(th) day there was difference between GI and GIII (p < 0.01). It may be concluded that, LLLT 688 nm and 785 nm accelerated dentin barrier formation and consequently pulp repair process, with best results using infrared laser 785 nm. (c) 2009 by Astro Ltd. Published exclusively by WLLEY-VCH Verlag GmbH & Co. KGaA

Automatic contour extraction from 2D neuron images

This work describes a novel methodology for automatic contour extraction from 2D images of 3D neurons (e.g. camera lucida images and other types of 2D microscopy). Most contour-based shape analysis methods cannot be used to characterize such cells because of overlaps between neuronal processes. The proposed framework is specifically aimed at the problem of contour following even in presence of multiple overlaps. First, the input image is preprocessed in order to obtain an 8-connected skeleton with one-pixel-wide branches, as well as a set of critical regions (i.e., bifurcations and crossings). Next, for each subtree, the tracking stage iteratively labels all valid pixel of branches, tip to a critical region, where it determines the suitable direction to proceed. Finally, the labeled skeleton segments are followed in order to yield the parametric contour of the neuronal shape under analysis. The reported system was successfully tested with respect to several images and the results from a set of three neuron images are presented here, each pertaining to a different class, i.e. alpha, delta and epsilon ganglion cells, containing a total of 34 crossings. The algorithms successfully got across all these overlaps. The method has also been found to exhibit robustness even for images with close parallel segments. The proposed method is robust and may be implemented in an efficient manner. The introduction of this approach should pave the way for more systematic application of contour-based shape analysis methods in neuronal morphology. (C) 2008 Elsevier B.V. All rights reserved.

Fast batch injection analysis of H(2)O(2) using an array of Pt-modified gold microelectrodes obtained from split electronic chips

A fast and robust analytical method for amperometric determination of hydrogen peroxide (H(2)O(2)) based on batch injection analysis (BIA) on an array of gold microelectrodes modified with platinum is proposed. The gold microelectrode array (n = 14) was obtained from electronic chips developed for surface mounted device technology (SMD), whose size offers advantages to adapt them in batch cells. The effect of the dispensing rate, volume injected, distance between the platinum microelectrodes and the pipette tip, as well as the volume of solution in the cell on the analytical response were evaluated. The method allows the H(2)O(2) amperometric determination in the concentration range from 0.8 mu mol L(-1) to 100 mu mol L(-1). The analytical frequency can attain 300 determinations per hour and the detection limit was estimated in 0.34 mu mol L(-1) (3 sigma). The anodic current peaks obtained after a series of 23 successive injections of 50 mu L of 25 mu mol L(-1) H(2)O(2) showed an RSD < 0.9%. To ensure the good selectivity to detect H(2)O(2), its determination was performed in a differential mode, with selective destruction of the H(2)O(2) with catalase in 10 mmol L(-1) phosphate buffer solution. Practical application of the analytical procedure involved H(2)O(2) determination in rainwater of Sao Paulo City. A comparison of the results obtained by the proposed ampermetric method with another one which combines flow injection analysis (FIA) with spectrophotometric detection showed good agreement. (C) 2011 Elsevier B.V. All rights reserved.

Ex Situ Scanning Electrochemical Microscopy (SECM) Investigation of Bismuth- and Bismuth/Lead Alloy Film-Modified Gold Electrodes in Alkaline Medium

Scanning electrochemical microscopy (SECM) in feedback mode was employed to characterise the reactivity and microscopic peculiarities of bismuth and bismuth/lead alloys plated onto gold disk substrates in 0.1 molL(-1) NaOH solutions. Methyl viologen was used as redox mediator, while a platinum microelectrode was employed as the SECM tip. The metal films were electrodeposited ex situ from NaOH solutions containing either bismuth ions only or both bismuth and lead ions. Approach curves and SECM images indicated that the metal films were conductive and locally reactive with oxygen to provide Bi(3+) and Pb(2+) ions. The occurrence of the latter chemical reactions was verified by local anodic stripping voltammetry (ASV) at the substrate solution interface by using a mercury-coated platinum SECM tip. The latter types of measurements allowed also verifying that lead was not uniformly distributed onto the bismuth film electrode substrate. These findings were confirmed by scanning electron microscopy images. The surface heterogeneity produced during the metal deposition process, however, did not affect the analytical performance of the bismuth coated gold electrode in anodic stripping voltammetry for the determination of lead in alkaline media, even in aerated aqueous solutions. Under the latter conditions, stripping peak currents proportional to lead concentration with a satisfactory reproducibility (within 5% RSD) were obtained.

Automated two-dimensional separation flow system with electrochemical preconcentration, stripping, capillary electrophoresis and contactless conductivity detection for trace metal ion analysis

This paper describes the automation of a fully electrochemical system for preconcentration, cleanup, separation and detection, comprising the hyphenation of a thin layer electrochemical flow cell with CE coupled with contactless conductivity detection (CE-C(4)D). Traces of heavy metal ions were extracted from the pulsed-flowing sample and accumulated on a glassy carbon working electrode by electroreduction for some minutes. Anodic stripping of the accumulated metals was synchronized with hydrodynamic injection into the capillary. The effect of the angle of the slant polished tip of the CE capillary and its orientation against the working electrode in the electrochemical preconcentration (EPC) flow cell and of the accumulation time were studied, aiming at maximum CE-C(4)D signal enhancement. After 6 min of EPC, enhancement factors close to 50 times were obtained for thallium, lead, cadmium and copper ions, and about 16 for zinc ions. Limits of detection below 25 nmol/L were estimated for all target analytes but zinc. A second separation dimension was added to the CE separation capabilities by staircase scanning of the potentiostatic deposition and/or stripping potentials of metal ions, as implemented with the EPC-CE-C(4)D flow system. A matrix exchange between the deposition and stripping steps, highly valuable for sample cleanup, can be straightforwardly programmed with the multi-pumping flow management system. The automated simultaneous determination of the traces of five accumulable heavy metals together with four non-accumulated alkaline and alkaline earth metals in a single run was demonstrated, to highlight the potentiality of the system.

Nytt fordon för transport av bränsleflis : Slutrapport (STEM-projekt 22127-1)

Högskolan Dalarna har i samarbete med Naturbränsle i Mellansverige AB genomfört studier på ett nytt fordon för transport av skogsflis. Fordonet är försett med egen lastningsutrustning (kran och skopa), vilket innebär att flisskördaren kan tippa flisen direkt på marken eller på en i förväg utlagd duk (minskar risken för föroreningar i samband med lastning). Studier har också genomförts på transport av flis med lastväxlarfordon och container (traditionell metod) för att jämförelser skall kunna göras mellan de olika fordonstyperna. Studierna har finansie¬rats via anslag från Statens Energimyndighet och via ”naturabidrag” från deltagande företag.Studierna visar att det nya transportfordonet är ett bättre alternativ än de traditionella last¬växlarfordonen på större objekt med långa transportavstånd. Dessutom pekar studien på att det är sannolikt är bättre även på små objekt under förutsättning att flisningskostnaden kan hållas på en rimlig nivå. Studierna visar också att det bör finnas en viss utvecklingspotential på det nya fordonet (teknik- och metodutveckling), varför det bedöms kunna konkurrera med lastväxlarfordonen även på andra typer av objekt.Jämfört med de traditionella lastväxlarfordonen har det nya fordonet bl.a. följande fördelar:•Transportarbetet blir lättare att planera i och med att beroendeförhållandet mellan in¬blandade maskiner och fordon för flisproduktion och transport upphör.••Risken för störningar i transportflödet minskar.•Miljövinsterna blir större jämfört med lastväxlarfordon som måste ställa ut tomma con¬tainrar innan flisningen kan påbörjas.•Det finns inget behov av lastmaskiner på terminalerna.•Flis kan mellanlagras i skogen.Till nackdelarna med det nya fordonet hör bl.a. följande:•Framkomligheten är något sämre än för lastväxlarfordon på mycket smala och kurviga skogsbilvägar.•Det finns en viss risk för att föroreningar följer med vid lastning av fordonet. Studies were carried out on a new vehicle for transport of fuel chips from the forest. The vehicle was equipped with a crane and a bucket meaning that the chipper may tip the fuel chips right on the ground or on a mat (vira from wood processing industry) to prevent from dirt such as sand and stones when loading. Studies were also carried out on traditional main hauling with transport bins. Transport speed was the same for all vehicles except for the new self-loader on forest roads with lower quality.The studies show that the new system probably is a better alternative on large sites with long transport distances and on sites with only little parking place for transport bins. It is also likely that the new vehicle may be used on very small sites if they are close to each other and if moving cost for the chipper is low.The studies show that the new vehicle has the following advantages:•Transport and other work may be planned in a better way leading to that stress de¬creases.•Dependence between chipper operators and truck drivers decreases.•The risk for disturbances in transport flow decreases.•Environment benefits compared to traditional system with higher traffic intensity (less exhaust gases and lower stress on roads and bridges).•No need for loading machines on terminals.•Easier to store fuel chips on landing.

Automatic spiral analysis for objective assessment of motor symptoms in Parkinson's disease

Objective: To develop a method for objective quantification of PD motor symptoms related to Off episodes and peak dose dyskinesias, using spiral data gathered by using a touch screen telemetry device. The aim was to objectively characterize predominant motor phenotypes (bradykinesia and dyskinesia), to help in automating the process of visual interpretation of movement anomalies in spirals as rated by movement disorder specialists. Background: A retrospective analysis was conducted on recordings from 65 patients with advanced idiopathic PD from nine different clinics in Sweden, recruited from January 2006 until August 2010. In addition to the patient group, 10 healthy elderly subjects were recruited. Upper limb movement data were collected using a touch screen telemetry device from home environments of the subjects. Measurements with the device were performed four times per day during week-long test periods. On each test occasion, the subjects were asked to trace pre-drawn Archimedean spirals, using the dominant hand. The pre-drawn spiral was shown on the screen of the device. The spiral test was repeated three times per test occasion and they were instructed to complete it within 10 seconds. The device had a sampling rate of 10Hz and measured both position and time-stamps (in milliseconds) of the pen tip. Methods: Four independent raters (FB, DH, AJ and DN) used a web interface that animated the spiral drawings and allowed them to observe different kinematic features during the drawing process and to rate task performance. Initially, a number of kinematic features were assessed including ‘impairment’, ‘speed’, ‘irregularity’ and ‘hesitation’ followed by marking the predominant motor phenotype on a 3-category scale: tremor, bradykinesia and/or choreatic dyskinesia. There were only 2 test occasions for which all the four raters either classified them as tremor or could not identify the motor phenotype. Therefore, the two main motor phenotype categories were bradykinesia and dyskinesia. ‘Impairment’ was rated on a scale from 0 (no impairment) to 10 (extremely severe) whereas ‘speed’, ‘irregularity’ and ‘hesitation’ were rated on a scale from 0 (normal) to 4 (extremely severe). The proposed data-driven method consisted of the following steps. Initially, 28 spatiotemporal features were extracted from the time series signals before being presented to a Multilayer Perceptron (MLP) classifier. The features were based on different kinematic quantities of spirals including radius, angle, speed and velocity with the aim of measuring the severity of involuntary symptoms and discriminate between PD-specific (bradykinesia) and/or treatment-induced symptoms (dyskinesia). A Principal Component Analysis was applied on the features to reduce their dimensions where 4 relevant principal components (PCs) were retained and used as inputs to the MLP classifier. Finally, the MLP classifier mapped these components to the corresponding visually assessed motor phenotype scores for automating the process of scoring the bradykinesia and dyskinesia in PD patients whilst they draw spirals using the touch screen device. For motor phenotype (bradykinesia vs. dyskinesia) classification, the stratified 10-fold cross validation technique was employed. Results: There were good agreements between the four raters when rating the individual kinematic features with intra-class correlation coefficient (ICC) of 0.88 for ‘impairment’, 0.74 for ‘speed’, 0.70 for ‘irregularity’, and moderate agreements when rating ‘hesitation’ with an ICC of 0.49. When assessing the two main motor phenotype categories (bradykinesia or dyskinesia) in animated spirals the agreements between the four raters ranged from fair to moderate. There were good correlations between mean ratings of the four raters on individual kinematic features and computed scores. The MLP classifier classified the motor phenotype that is bradykinesia or dyskinesia with an accuracy of 85% in relation to visual classifications of the four movement disorder specialists. The test-retest reliability of the four PCs across the three spiral test trials was good with Cronbach’s Alpha coefficients of 0.80, 0.82, 0.54 and 0.49, respectively. These results indicate that the computed scores are stable and consistent over time. Significant differences were found between the two groups (patients and healthy elderly subjects) in all the PCs, except for the PC3. Conclusions: The proposed method automatically assessed the severity of unwanted symptoms and could reasonably well discriminate between PD-specific and/or treatment-induced motor symptoms, in relation to visual assessments of movement disorder specialists. The objective assessments could provide a time-effect summary score that could be useful for improving decision-making during symptom evaluation of individualized treatment when the goal is to maximize functional On time for patients while minimizing their Off episodes and troublesome dyskinesias.

Relacao entre o angulo da ponta do eletrodo e a geometria do cordao de solda no processo de soldagem tig

No processo de soldagem TIG (Tungstênio Inerte Gás), um dos fatores que influenciam o formato do cordão de solda é o ângulo da extremidade do eletrodo. Para estudar o comportamento do arco elétrico em função da geometria de ponta do eletrodo e suas conseqüências nos cordões de solda, efetuaram-se soldagens sobre corpos de prova sem deposição de material (bead-on-plate) através de parâmetros controlados e a mecanização do processo. Parâmetros tais como vazão do gás, velocidade de avanço da tocha e comprimento do arco foram testados para verificar a atuação em conjunto com o ângulo do eletrodo. Pela análise metalográfica (macrografia) estudaram-se os perfis dos cordões de solda, verificando-se que o ângulo exerce uma influência significativa na característica do arco tensão-corrente, na largura e profundidade de penetração da solda. Para maiores ângulos de extremidade do eletrodo obteve-se aumento na penetração, diminuição da tensão e largura do cordão de solda para uma mesma intensidade de corrente.

Nutrição parenteral como fator de risco para infecção relacionada a cateter venoso central

O uso de cateteres venosos centrais (CVC) para fins diagnósticos e terapêuticos está incorporado à prática médica diária. Complicações sérias, com elevada morbidade e mortalidade, como a sepse, estão associadas a este procedimento. O diagnóstico das infecções relacionadas a cateter é fundamentado em sinais clínicos e laboratoriais. Os fatores de risco para infecção devem ser considerados por ocasião da utilização de CVC e estão relacionados ao paciente, ao cateter, ao tipo de solução administrada, ao profissional que manipula o cateter e ao agente etiológico. A identificação destes fatores permite a intervenção precoce sobre os mesmos e o manejo adequado do CVC e das complicações clínicas relacionadas.

Estudo comparativo entre a subvenção econômica à inovação operada pela Finep e programas correlatos de subsídio em países desenvolvidos

A inovação tecnológica é um dos principais fatores de competitividade das economias modernas e, em todos os países desenvolvidos, é objeto de políticas oficiais para sua promoção. No Brasil, a Financiadora de Estudos e Projetos (Finep) apóia o desenvolvimento tecnológico das empresas desde 1976. A partir de 2006, passou a operar também subsídios diretos na forma de subvenção econômica. Este estudo caracteriza a subvenção econômica no marco legal brasileiro, apresentando exemplos de sua utilização como política pública e, especificamente, a subvenção à inovação operada pela Finep no período de 2006 a 2009. Em seguida, o instrumento da Finep é comparado, por análise de conteúdo, com programas de subsídio correlatos em países desenvolvidos. Para tal, foram selecionados os programas norte americanos SBIR, ATP e TIP, e aqueles operados pela OSEO na França e CDTI na Espanha. São abordados aspectos relativos à lógica de intervenção, dando ênfase a questões como risco tecnológico, intensidade no apoio, modelos institucionais e integração de instrumentos de apoio.

Automação e robótica nas indústrias brasileiras: um estudo exploratório

A Automação e o processo de Robotização vêm, cada vem mais, se tornando pauta nas discussões de centenas de indústrias brasileiras, onde a tendência clara e identificada é a de investimentos expressivos na melhoria de processos e produtos, por intermédio dessas tecnologias; com foco, sempre que possível, na nacionalização de equipamentos. O presente trabalho tem como objetivo avaliar o modelo proposto por Paul Kennedy (1993) com relação à tendência de Automação e Robotização nas Indústrias Mundiais, analisando o estudo realizado diante de uma economia emergente como a brasileira. Para tanto, foram pesquisadas empresas no Brasil, em diferentes segmentos industriais, o estado da arte em termos de tecnologia de automação e robótica aplicada a processos industriais, e sugerido um modelo diferente do idealizado originalmente por Kennedy. A análise do autor se baseou no teorema que, na matemática discreta, chamamos de “law of the excluded middle”, ou seja, segundo Kennedy, o Brasil estaria vivendo hoje uma migração gradual das indústrias para os países ricos. O Brasil é um exemplo de país industrializado, de economia emergente, que investe intensamente em processos automatizados, mas que não é classificado dentro do grupo desses países ricos. Através da pesquisa realizada será apresentado um novo modelo, no qual países emergentes como o Brasil têm acesso à tecnologia de ponta em automação e robótica, aplicando a mesma em seus processos industriais.

Determinantes emocionais do compartilhamento entre consumidores online

O objetivo desta tese é contribuir com a análise das emoções, a partir dos papéis da valência e da excitação emocional, como influenciadoras do compartilhamento de informação entre consumidores online. Pessoas compartilham onversando ou utilizando ferramentas de compartilhamento de conteúdo na internet, como as redes sociais virtuais. O compartilhamento de conteúdo na internet leva a uma maior difusão, fazendo com que eles se viralizem, ou seja, sejam retransmitidos diversas vezes, atingindo diferentes públicos (HO; DEMPSEY, 2010). Ainda há dúvidas na literatura sobre as causas desta viralização, e o quanto as emoções influenciam o processo, articularmente se as pessoas tendem a compartilhar mais o que lhes é positivo, o que lhes causa mais excitação (BERGER; MILKMAN, 2012) ou se há um perfil específico de consumidor que se engaja mais nessas ações, como os chamados advogados de marca, e como tal perfil se comporta. Para investigar isso, foram conduzidos quatro experimentos: o primeiro comparou a propensão a compartilhar notícias de valências emocionais e excitações diferentes, o segundo relacionou a propensão a compartilhar propagandas e notícias com valências diferentes, o terceiro analisou como advogados de marca declarados agem com relação a conteúdo de diferentes valências e o quarto comparou a propensão a compartilhar de propagandas com diferentes valências e estímulos ao compartilhamento (nenhum, dica de um amigo ou participação em um sorteio). Os conteúdos de valência positiva que geraram maior excitação ou tidos como mais úteis seriam mais compartilhados, enquanto advogados de marca deram ênfase em suas respostas ao conteúdo negativo, negando-o, justificando-o ou se abstendo, e foram mais intensos ao reclamar de problemas que eles próprios sofreram. Os principais achados desta tese são que a) conteúdo online de valência positiva e de alta excitação tem maior probabilidade de ser compartilhado, porém b) conteúdo online de valência negativa é tido como mais útil e gera maior excitação. Além disso, c) se o conteúdo for referente a uma marca com que o consumidor é engajado, ele reagirá com respostas mais circunstanciadas e d) se o conteúdo lhe for indicado por um amigo, ele tem maior chance de compartilhar. A principal contribuição desta tese é auxiliar na compreensão, teórica e gerencial, do compartilhamento entre usuários, avaliando o 9 impacto de conteúdo excitante ou útil, seja de valência positiva ou negativa, permitindo às organizações dimensionar seus esforços de comunicação e de relacionamento com clientes, com vistas a selecionar as abordagens mais adequadas às mensagens

De gata borralheira a Cinderela :nova espacialidade decorrente do desenvolvimento turístico, diferenciada pelo estilo de vida em Ponta Negra, Natal, RN

The transformations economical, social and politics in you finish them decades of the century XX brought changes that didn't just limit to the production system. The flexible accumulation took many workers lost her/it their workstations and they look for her/it new survival forms, migrating for administrative activities, of services rendered and for the tourist activity of small and medium load. The State has been investing in the implantation of plans of tourist development in order to create favorable conditions for the reproduction of the tourist activity in Brazil, mainly in the Northeast. A space when it starts to present a predominant economical activity suffers a restructuring in their social and economical relationships. The restructuring of these relationships takes to the construction of a new espacialidade. In the city of Christmas, in Rio Grande do Norte, the neighborhood of Black Tip is the most representative of the public investments for the tourist development. After intense process of tourist urbanization, Black Tip passed interfering in the global context consolidating as the tourist locus in the city. The tourist urbanization of the neighborhood took to the transformation of the space in merchandise that is sold and consumed as such. The recreation of fragments of other cultures brought by social actors, resulting from migratory processes stimulated by the tourist development, it has been presenting ruled social relationships in the informational technology, consumption of global goods and in the fragmentation of the urban space characterized by the internationalization and cosmopolitização. That process has been masking the inequalities partners and cultural as well as the territorial appropriation for an economical elite. The spaces are being appropriate for investors of the tourist section, private investors, agents and real estate producers, where the inequality is not just economical, but also cultural. The local population, mainly of the urban fraction of the Town of Black Tip, it doesn't participate of the productive process in function of the little or any professional qualification and he/she doesn't also have access to the consumption process. To the native ones it remains the fight for the preservation of his/her cultural identity and for the survival