Tecnologia flextec aplicada ao sector da construção

Na primeira parte do presente estudo, são apresentadas, resumidamente, as tecnologias de adesivos e vedantes, que servem de base para a apresentação da tecnologia Flextec®, uma tecnologia que junta o melhor destes dois tipos de materiais. Relativamente aos adesivos apresentam-se algumas das teorias de adesão, a ligação adesiva ao longo dos tempos, as vantagens e desvantagens da utilização de adesivos e por fim, os diversos tipos de adesivos e suas principais aplicações. Relativamente aos vedantes, a introdução é semelhante, referindo-se os seus tipos, classificação e aplicações, nomeadamente a aplicação em juntas. Uma vez que a tecnologia em estudo, é um exclusivo Henkel, foi dedicada uma parte da introdução para a apresentação da empresa e do seu portfólio de produtos, destacando-se aqueles que se apresentam como soluções recentes e inovadores, nas suas gamas, dentro da divisão de construção. Após esta introdução, é apresentada a tecnologia Flextec®, com as suas vantagens, campos de aplicação e gama de produtos associados. Na segunda parte, apresentam-se os resultados do trabalho experimental realizado nas instalações da Henkel, com um dos produtos com tecnologia Flextec® - Sista Solyplast SP-301 Fachadas, em que foram elaborados 42 provetes com diferentes tipos de materiais utilizados em fachadas e o adesivo. Os provetes foram sujeitos a ensaios qualitativos de tracção e a maioria deles apresentou ruptura coesiva, resultado que garante que o produto cumpre os requisitos do certificado CIDEMCO apresentado pelo produto. Nesta segunda parte, são também apresentados outros trabalhos relacionados com utilização da tecnologia Flextec®, em novas soluções de construção.

Controlo da qualidade em radioterapia externa

Sendo a radioterapia (RT) uma modalidade terapêutica cada vez mais complexa e precisa em oncologia, torna-se pertinente refletir sobre alguns conceitos e procedimentos acerca da qualidade e do controlo da qualidade a ela associados, uma vez que se encontram profundamente aplicados nos centros de radioterapia já existentes. Estes conceitos e procedimentos estão bem sustentados em muitas experiências clinicas e em estudos acessíveis numa vasta série de artigos científicos publicados em revistas e outras fontes credíveis e científicas. A metodologia utilizada para a elaboração deste trabalho passa pela pesquisa e revisão de material bibliográfico existente não só em livros de referência como também em artigos de revistas da área da física médica, radioterapia e oncologia. A estrutura do trabalho passa pela descrição do “estado-da-arte” atual, sendo que, e nesta perspetiva, se tenha recorrido ao percurso evolutivo dos conceitos e procedimentos tidos ao longo do desenvolvimento das tecnologias e técnicas em radioterapia. O que se observa neste trabalho é que “Qualidade em Radioterapia” envolve uma complexa estrutura não só de recursos físicos como também humanos, onde uma pequena falha de comunicação no elo de ligação entre os diversos membros da equipa compromete afinal aquilo que é o seu objetivo major: tratar com qualidade e dignidade o doente oncológico.

Optical demultiplexer based on an a-SiC:H voltage controlled device

In this paper we present results on the use of a semiconductor heterostructure based on a-SiC:H as a wavelength-division demultiplexer for the visible light spectrum. The proposed device is composed of two stacked p-i-n photodiodes with intrinsic absorber regions adjusted to short and long wavelength absorption and carrier collection. An optoelectronic characterisation of the device was performed in the visible spectrum. Demonstration of the device functionality for WDM applications was done with three different input channels covering the long, the medium and the short wavelengths in the visible range. The recovery of the input channels is explained using the photocurrent spectral dependence on the applied voltage. An electrical model of the WDM device is proposed and supported by the solution of the respective circuit equations. Short range optical communications constitute the major application field however other applications are foreseen. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optical processing devices based on a-SiCH multilayer architectures

Red, green and blue optical signals were directed to an a-SiC:H multilayered device, each one with a specific transmission rate. The combined optical signal was analyzed by reading out, under different applied voltages, the generated photocurrent. Results show that when a chromatic time dependent wavelength combination with different transmission rates irradiates the multilayered structure, the device operates as a tunable wavelength filter and can be used in wavelength division multiplexing systems for short range communications. An application to fluorescent proteins detection is presented. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Optoelectronic properties of a-Si(1-x)C(x)H films grown in hydrogen diluted silane-methane plasma

This work reports on the optoelectronic properties and device application of hydrogenated amorphous silicon carbide (a-Si(1-x)C(x):H) films grown by plasma-enhanced chemical vapour deposition (PECVD). The films with an optical bandgap ranging from about 1.8 to 2.0 eV were deposited in hydrogen diluted silane-methane plasma by varying the radio frequency power. Several n-i-p structures with an intrinsic a-Si(1-x)C(x):H layer of different optical gaps were also fabricated. The optimized devices exhibited a diode ideality factor of 1.4-1.8, and a leakage current of 190-470 pA/cm(2) at -5 V. The density of deep defect states in a-Si(1-x)C(x):H was estimated from the transient dark current measurements and correlated with the optical bandgap and carbon content. Urbach energies for the valence band tail were also determined by analyzing the spectral response within sub-bandgap energy range. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

CuxSnSx+1 (x = 2, 3) thin films grown by sulfurization of metallic precursors deposited by dc magnetron sputtering

We report the results of the growth of Cu-Sn-S ternary chalcogenide compounds by sulfurization of dc magnetron sputtered metallic precursors. Tetragonal Cu2SnS3 forms for a maximum sulfurization temperature of 350 ºC. Cubic Cu2SnS3 is obtained at sulfurization temperatures above 400 ºC. These results are supported by XRD analysis and Raman spectroscopy measurements. The latter analysis shows peaks at 336 cm-1, 351 cm-1 for tetragonal Cu2SnS3, and 303 cm-1, 355 cm-1 for cubic Cu2SnS3. Optical analysis shows that this phase change lowers the band gap from 1.35 eV to 0.98 eV. At higher sulfurization temperatures increased loss of Sn is expected in the sulphide form. As a consequence, higher Cu content ternary compounds like Cu3SnS4 grow. In these conditions, XRD and Raman analysis only detected orthorhombic (Pmn21) phase (petrukite). This compound has Raman peaks at 318 cm-1, 348 cm-1 and 295 cm-1. For a sulfurization temperature of 450 ºC the samples present a multi-phase structure mainly composed by cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4. For higher temperatures, the samples are single phase and constituted by orthorhombic (Pmn21) Cu3SnS4. Transmittance and reflectance measurements were used to estimate a band gap of 1.60 eV. For comparison we also include the results for Cu2ZnSnS4 obtained using similar growth conditions.

Influence of selenization pressure on the growth of Cu2ZnSnSe4 films from stacked metallic layers

Cu2ZnSnSe4 (CZTSe) is a p-type semiconductor with a high absorption coefficient, 104 to 105 cm-1, and is being seen as a possible replacement for Cu(In,Ga)Se2 in thin film solar cells. Yet, there are some fundamental properties of CZTSe that are not well known, one of them is its band gap. In order to resolve its correct value it is necessary to improve the growth conditions to ensure that single phase crystalline thin films are obtained. One of the problems encountered when growing CZTSe is the loss of Sn through evaporation of SnSe. Stoichiometric films are then difficult to obtain and usually there are other phases present. One possible way to overcome this problem is to increase the pressure of growth of CZTSe. This can be done by introducing an atmosphere of an inert gas like Ar or N2. In this work we report the results of morphological, structural and optical studies of the properties of CZTSe thin films grown by selenization of DC magnetron sputtered metallic layers under different Ar pressures. The films are analysed by SEM/EDS, Raman scattering and XRD.

Fisheries Safety Management

Fisheries is one of the most dangerous professions in the world. Fatal accidents and injuries in the fisheries are characterized as well as particular circumstances that may cause or aggravate the risk of accidents. Aspects of safety management of fishing vessels are covered in this paper: areas of concern when doing a risk assessment in fishing vessels, fundamental elements on a safety management system for the fisheries and the need for international and national level instruments as well as legal and compulsory measures

Characterization approach to modified glassy carbon electrode-nanofilm system within multidimensional scaling

The aim of this work is to characterize the nanofilm consisting of the benzoic acid-modified glassy carbon (GC) electrode system through multidimensional scaling space analysis. The surface modification is based on the electrochemical reaction between the GC electrode and benzoic acid-diazonium salt (BA-DAS). As a result, the nonofilms regarding the benzoic acid-glassy carbon (BA-GC) electrode surface was obtained. For the analysis of the naonfilm of BC-GC electrode system, the IR spectra of the modified BA-GC electrode surface, GC surface and BA-DAS were recorded in the spectral range of 599.84 – 3996.34 [cm–1]. The IR data vectors of the above three forms were processed by the using the multidimensional scaling space approach to demonstrate the existence of a nanofilm on the modified BA-GC electrode system. Two- and three-dimensional MDS profiles obtained by application of multidimensional scaling approach to the data sets {CG1,...,CG10}, {BA-GC1,...,BA-GC10} and {FILM1,...,FILM10} allow a good recognition of the nanofilm on the modified glassy carbon (GC) electrode system.

Avaliação do teste de imunofluorescência indireta para diagnóstico da filariose bancroftiana usando a microfilária de W. bancrofti como antígeno, em Recife-PE, Brasil

Analisou-se o teste de imunofluorescência indireta com microfilárias de W. bancrofti tratadas pela papaína, como antígeno, amplamente utilizado em Recife para o imunodiagnóstico da filariose linfática. Foram testados soros de 50 pacientes portadores das diversas formas clínicas da doença, incluindo microfilaremia assintomática, eosinofilia pulmonar tropical, elefantíase de membros inferiores, linfagite aguda e quilúria. Para o grupo controle, foram selecionados 50 indivíduos vivendo pelo menos há 5 anos em área endêmica, sem nenhuma evidencia clínica e/ou laboratorial da doença, constituindo os chamados endêmicos normais. A sensibilidade e especificidade do teste, segundo diferentes pontos de corte, mostraram a impossibilidade de diferenciação entre o grupo controle e o grupo sabidamente infectado. Também não foi possível estabelecer correlação entre os títulos encontrados e as diferentes formas clínicas. Foi considerada a existência de reações cruzadas relacionadas a helmintíases intestinais, porém nenhuma relação direta foi encontrada.

Negotiation mechanism for self-organized scheduling system with collective intelligence

Current Manufacturing Systems challenges due to international economic crisis, market globalization and e-business trends, incites the development of intelligent systems to support decision making, which allows managers to concentrate on high-level tasks management while improving decision response and effectiveness towards manufacturing agility. This paper presents a novel negotiation mechanism for dynamic scheduling based on social and collective intelligence. Under the proposed negotiation mechanism, agents must interact and collaborate in order to improve the global schedule. Swarm Intelligence (SI) is considered a general aggregation term for several computational techniques, which use ideas and inspiration from the social behaviors of insects and other biological systems. This work is primarily concerned with negotiation, where multiple self-interested agents can reach agreement over the exchange of operations on competitive resources. Experimental analysis was performed in order to validate the influence of negotiation mechanism in the system performance and the SI technique. Empirical results and statistical evidence illustrate that the negotiation mechanism influence significantly the overall system performance and the effectiveness of Artificial Bee Colony for makespan minimization and on the machine occupation maximization.

Distribucion geografica de Lutzomyia verrucarum (Townsend, 1913) (Diptera, Psychodidae, Phlebotominae), vector de la batonellosis humana en el Peru

Lutzomyia verrucarum (Townsend, 1913) (Diptera: Psychodidae), vector natural de la verruga peruana o enfermedad de Carrión es una especie propia del Perú. Su distribución geográfica esta entre los paralelos 5º y 13º25' de latitud Sur, se encuentra en los valles Occidentales e Interandinos de los Andes. La distribución altitudinal de Lu. verrucarum en los diversos valles es variable; asi: Occidentales, desde 1100 hasta 2980 msnm e Interandinos, de 1200 a 3200 msnm. En ciertas áreas verrucógenas no hay correlación entre la presencia de Lu. verrucarum y la enfermedad de Carrión lo que suguiere la existencia de vectores secundarios.

Field evaluation of the whole blood immunochromatographic test for rapid bancroftian filariasis diagnosis in the northeast of Brazil

This study evaluated the whole blood immunochromatographic card test (ICT card test) in a survey performed in Northeastern Brazil. 625 people were examined by the thick blood film (TBF) and ICT card test. Residents of a non-endemic area were also tested by the whole blood card test and Og4C3. The sensitivity of the ICT card test was 94.7% overall, but lower in females than males, based on the reasonable assumption that TBF is 100% specific. However, since TBF and other methods have unknown sensitivity, the true specificity of the card test is unknown. Nevertheless, it is possible to estimate upper and lower limits for the specificity, and relate it to the prevalence of the disease. In the endemic area, the possible range of the specificity was from 72.4% to 100%. 29.6% of the card tests performed in the non-endemic area exhibited faint lines that were interpreted as positives. Characteristics of the method including high sensitivity, promptness and simplicity justify its use for screening of filariasis. However, detailed information about the correct interpretation in case of extremely faint lines is essential. Further studies designed to consider problems arising from imperfect standards are necessary, as is a sounder diagnostic definition for the card test.

Lymph scrotum: an unusual urological presentation of lymphatic filariasis. A case series study

Lymphatic filariasis (LF) causes a wide range of clinical signs and symptoms, including urogenital manifestations. Transmission control and disability/morbidity management/control are the two pillars of the overall elimination strategy for LF. Lymph scrotum is an unusual urological clinical presentation of LF with important medical, psychological, social and economic repercussions. A retrospective case series study was conducted on outpatients attended at the National Reference Service for Filariasis, in an endemic area for filariasis (Recife, Brazil), between 2000 and 2007. Over this period, 6,361 patients were attended and seven cases with lymph scrotum were identified. Mean patient age was 45 years (range, 26 to 64 years). Mean disease duration was 8.5 years (range, two to 15 years). All patients had evidence of filarial infection from at least one laboratory test (parasitological, antigen investigation or "filarial dance sign" on ultrasound). Six patients presented histories of urological surgery. The authors highlight the importance of the association between filarial infection and the inadequate surgical and clinical management of hydrocele in an endemic area, as risk factors for lymph scrotum. Thus, filarial infection should be routinely investigated in all individuals presenting urological morbidity within endemic areas, in order to identify likely links in the transmission chain.

Epidemiological investigation of an acute case of Chagas disease in an area of active transmission in Peruvian Amazon region

The study objective was to investigate an acute case of Chagas disease in the San Pedro de Shishita community, Pebas District, in the Peruvian Amazon basin, a non-endemic area. Both parents of the index case (acute case) were thoroughly interviewed, a seroepidemiological survey was carried out in the community, parasitological exams were carried out only in relatives of the index case, and triatomine bugs were searched for inside houses, peridomiciliary, and in wild environments. Seroprevalence for IgG anti-T. cruzi antibodies was 1/104 (0.96%), using an ELISA test and an indirect immunofluorescence assay. Panstrongylus geniculatus and Rhodnius pictipes adults were found. The index case is autochthonous from San Pedro de Shishita, but the source of transmission is unknown.