A poluição gerada por máquinas de combustão interna movidas à diesel - a questão dos particulados. Estratégias atuais para a redução e controle das emissões e tendências futuras

The exhaust emissions of vehicles greatly contribute to environmental pollution. Diesel engines are extremely fuel-efficient. However, the exhaust compounds emitted by diesel engines are both a health hazard and a nuisance to the public. This paper gives an overview of the emission control of particulates from diesel exhaust compounds. The worldwide emission standards are summarized. Possible devices for reducing diesel pollutants are discussed. It is clear that after-treatment devices are necessary. Catalytic converters that collect particulates from diesel exhaust and promote the catalytic burn-off are examined. Finally, recent trends in diesel particulate emission control by novel catalysts are presented.

Análise sistemática de reagentes e resíduos sem identificação

This work presents a detailed routine applied to the identification of unknown chemicals and wastes. 786 specimens were analyzed during 20 months. Unknown materials fell into three basic classes: (i) commercial chemicals without labels or illegible ones; (ii) laboratory synthesis products; (iii) used solvents (including mixtures). Uranium and thorium were recovered form their wastes. Unknown chemicals were mainly inorganic compounds, many of which had never been opened. Alkaline salts were dominant, but also precious metal compounds were identified. Laboratory synthesis products were organic compounds. The final destination depended on the nature of the chemical. Most organic compounds were sent to incineration; inorganic salts were distributed among several public organizations, including secondary and technical schools. The work described in this paper greatly reduced the amount of wastes that had to be sent to disposal.

The effects of real time control of welding parameters on weld quality in plasma arc keyhole welding

Joints intended for welding frequently show variations in geometry and position, for which it is unfortunately not possible to apply a single set of operating parameters to ensure constant quality. The cause of this difficulty lies in a number of factors, including inaccurate joint preparation and joint fit up, tack welds, as well as thermal distortion of the workpiece. In plasma arc keyhole welding of butt joints, deviations in the gap width may cause weld defects such as an incomplete weld bead, excessive penetration and burn through. Manual adjustment of welding parameters to compensate for variations in the gap width is very difficult, and unsatisfactory weld quality is often obtained. In this study a control system for plasma arc keyhole welding has been developed and used to study the effects of the real time control of welding parameters on gap tolerance during welding of austenitic stainless steel AISI 304L. The welding tests demonstrated the beneficial effect of real time control on weld quality. Compared with welding using constant parameters, the maximum tolerable gap width with an acceptable weld quality was 47% higher when using the real time controlled parameters for a plate thickness of 5 mm. In addition, burn through occurred with significantly larger gap widths when parameters were controlled in real time. Increased gap tolerance enables joints to be prepared and fit up less accurately, saving time and preparation costs for welding. In addition to the control system, a novel technique for back face monitoring is described in this study. The test results showed that the technique could be successfully applied for penetration monitoring when welding non magnetic materials. The results also imply that it is possible to measure the dimensions of the plasma efflux or weld root, and use this information in a feedback control system and, thus, maintain the required weld quality.

Funciones y uso de metáforas en el diseño de entornos e-learning

El objeto de esta comunicación es presentar un estudio exploratorio sobre las funciones y tipologías de metáfora estructurales presentes en productos de e-learning, para estudiar con más detalle dos ejemplos: Geolearning y Activewolds. Estos servirán para realizar un ejercicio de identificación de los elementos audiovisuales presentes en la interface, el tratamiento de las dimensiones espacio y tiempo; el uso de 'avatares' y de las posibilidades de navegación e interacción dentro de los dos sistemas. La teoría de la muldimodalidad (Kress i van Leeuwen) es el marco teórico que conduce la reflexión sobre la representación, orientación y organización de la comunicación. Desde la misma perspectiva teórica, el trabajo de Burn y Parker nos indica pautas metodológicas para el análisis de los productos

Peutz-Jeghers syndrome: a systematic review and recommendations for management

Peutz¿Jeghers syndrome (PJS, MIM175200) is an autosomal dominant condition defined by the development of characteristic polyps throughout the gastrointestinal tract and mucocutaneous pigmentation. The majority of patients that meet the clinical diagnostic criteria have a causative mutation in the STK11 gene, which is located at 19p13.3. The cancer risks in this condition are substantial, particularly for breast and gastrointestinal cancer, although ascertainment and publication bias may have led to overestimates in some publications. Current surveillance protocols are controversial and not evidence-based, due to the relative rarity of the condition. Initially, endoscopies are more likely to be done to detect polyps that may be a risk for future intussusception or obstruction rather than cancers, but surveillance for the various cancers for which these patients are susceptible is an important part of their later management. This review assesses the current literature on the clinical features and management of the condition, genotype¿phenotype studies, and suggested guidelines for surveillance and management of individuals with PJS. The proposed guidelines contained in this article have been produced as a consensus statement on behalf of a group of European experts who met in Mallorca in 2007 and who have produced guidelines on the clinical management of Lynch syndrome and familial adenomatous polyposis.

Rendimento térmico e emissões de contaminantes atmosféricos de gasolinas formuladas com etanol, MBTE e TAEE

The specific consumption and carbon monoxide (CO) and nitrogen oxide (NO) emissions from gasolines formulated with ethanol, methyl tert-butyl ether (MTBE) and tert-amyl ethyl ether (TAEE) were evaluated in the rich, stoichiometric and lean-burn regions during the operation of an Otto-cycle engine. The use of ethanol as an additive presented high specific consumption, while gasoline formulated with TAEE showed low specific consumption with the engine operating under lean-burn conditions. The ethers evaluated here presented a low percentage of CO in the rich-burn region when compared with ethanol.

El Burnout percibido o sensación de estar quemado en profesionales sanitarios: prevalencia y factores asociados

Depending on the various models explaining the burnout syndrome, different questionnaires have been developed to asses this topic, the most widely-used is the Maslach Burnout Inventory (MBI). Moreover, in trying to asses this syndrome in a faster and more practical way, several authors have developed other instruments with fewer items. The present investigation aims: 1. Study the prevalence of burnout syndrome perceived using a simple measure of self-reported burnout, and to analyse its association with the scales of MBI. 2. Study demographic and work conditions associated with the perceived burnout. 3. Relate the burnout to personal and work evaluations. The sample consist of 6150 health professionals in Latin America (mainly from Argentina but with representation from Mexico, Ecuador, Peru, Colombia, Uruguay, Guatemala and Spain, among others. The mean age of the sample was 42.4 years, 52.7% were males. They were supplied with an online questionnaire through the health web page ”Intramed” in order to measure characteristics, perceptions and professional opinions. The MBI and a simple question to assess perceptions of burnout (Do you feel burnt out ?) was also included. The results indicated that 36.3% of the sample has the perception of “burnt out” or burnout . The perceived burnout is closely related to emotional exhaustion and is independent of depersonalisation. The burnout is associated with the perceived sense of personal and family deterioration due to working conditions, and the idea of abandoning the profession

Retroalimentación docencia-asistencia-docencia: estudio sobre burnout en enfermeras de salud mental como estrategia de innovación y calidad docente

El síndrome de burnout se considera una vulnerabilidad en las profesiones de ayuda. La escasez de publicaciones sobre esta formación, orientó la creación de una asignatura optativa en el Grado de Enfermería de la Universidad de Barcelona (UB) en el curso 2009-2010. Igualmente, produjo interés por explorar esta temática en enfermeras asistenciales de salud mental cuya disciplina aborda la gestión del estrés. Se presenta un estudio descriptivo, transversal y de correlación, en una cohorte de 73 enfermeras que trabajaban en servicios asistenciales de salud mental en el año 2011. Los objetivos pretenden identificar si la muestra estudiada presenta afectación del síndrome de burnout y relacionar los resultados con las estrategias que dichas enfermeras declaran utilizar para hacer frente a las emociones negativas atribuidas a su trabajo. El instrumento empleado es el Maslach Burnout Inventory (MBI), una pregunta abierta y variables sociodemográficas y de salud. Los resultados indican que presentó burnout el 2,7% de la muestra estudiada junto con un nivel medio de despersonalización. Además presentan baja realización personal quienes trabajaban en unidades de enfermos crónicos. El cansancio emocional resulto mayor en mujeres que en hombres y esta presente en personal con contrato fijo y en quienes causaron baja en los dos últimos años. En general, se observa falta de formación y apoyo formal para gestionar el estrés en la muestra estudiada. Se concluye que la formación sobre burnout en el Grado de Enfermería, podría favorecer la gestión del estrés y prevenir su cronicidad hacia la desmotivación y el absentismo laboral.

Retroalimentación docencia-asistencia-docencia: estudio sobre burnout en enfermeras de salud mental como estrategia de innovación y calidad docente

El síndrome de burnout se considera una vulnerabilidad en las profesiones de ayuda. La escasez de publicaciones sobre esta formación, orientó la creación de una asignatura optativa en el Grado de Enfermería de la Universidad de Barcelona (UB) en el curso 2009-2010. Igualmente, produjo interés por explorar esta temática en enfermeras asistenciales de salud mental cuya disciplina aborda la gestión del estrés. Se presenta un estudio descriptivo, transversal y de correlación, en una cohorte de 73 enfermeras que trabajaban en servicios asistenciales de salud mental en el año 2011. Los objetivos pretenden identificar si la muestra estudiada presenta afectación del síndrome de burnout y relacionar los resultados con las estrategias que dichas enfermeras declaran utilizar para hacer frente a las emociones negativas atribuidas a su trabajo. El instrumento empleado es el Maslach Burnout Inventory (MBI), una pregunta abierta y variables sociodemográficas y de salud. Los resultados indican que presentó burnout el 2,7% de la muestra estudiada junto con un nivel medio de despersonalización. Además presentan baja realización personal quienes trabajaban en unidades de enfermos crónicos. El cansancio emocional resulto mayor en mujeres que en hombres y esta presente en personal con contrato fijo y en quienes causaron baja en los dos últimos años. En general, se observa falta de formación y apoyo formal para gestionar el estrés en la muestra estudiada. Se concluye que la formación sobre burnout en el Grado de Enfermería, podría favorecer la gestión del estrés y prevenir su cronicidad hacia la desmotivación y el absentismo laboral.

Formulation and characterization of poloxamer 407®: thermoreversible gel containing polymeric microparticles and hyaluronic acid

The influence of the composition and preparation method on the sol-gel transition temperature (Tsol-gel) and rheological response of poloxamer-based formulations was determined. Manual and more complex mechanical stirring were found to provide similar results. In addition, a linear dependence of Tsol-gel on the poloxamer content was observed in the range of concentrations analyzed, and a Poloxamer 407® concentration of 18% was selected. The addition of hyaluronic acid did not lead to significant changes in the Tsol-gel values. In contrast, the addition of microparticles caused a reduction in Tsol-gel without a significant reduction in gel strength, and pseudoplastic characteristics were observed, indicating that a thermoreversible gel was obtained with a rheology suitable for application in the treatment of burn wounds.

Genetic diversity among isolates of stemphylium solani from cotton

The fungus Stemphylium solani causes leaf blight of tomato (Lycopersicon esculentum) in Brazil. In recent years, severe epidemics of a new leaf blight of cotton (Gossipium hyrsutum) caused by S. solani occurred in three major cotton-growing Brazilian states (PR, MT and GO). Molecular analysis was performed to assess the genetic diversity among the S. solani isolates from cotton, and to verify their relationship with representative S. solani isolates from tomato. Random amplified polymorphic DNA (RAPD) markers and internal transcribed spacers of ribosomal DNA (rDNA) were used to compare 33 monosporic isolates of S. solani (28 from cotton and five from tomato). An isolate of Alternaria macrospora from cotton was also used for comparison. RAPD analysis showed the presence of polymorphism between the genera and the species. The A. macrospora and the S. solani isolates from cotton and tomato were distinct from each other, and fell into separate groups. Variation by geographic region was observed for the tomato isolates but not for the cotton isolates. Amplifications of the ITS region using the primer pair ITS4/ITS5 resulted in a single PCR product of approximately 600 bp for all the isolates. Similarly, when amplified fragments were digested with eight restriction enzymes, identical banding patterns were observed for all the isolates. Hence, rDNA analysis revealed no inter-generic or intra-specific variation. The genetic difference observed between the cotton and the tomato isolates provides evidence that S. solani attacking cotton in Brazil belongs to a distinct genotype.

Synthesis and characterization of activated carbon fibers from Kevlar

Kevlar [poly (p-phenilylene terephtalamide)], was used as a precursor in the preparation of activated carbon fibers. For this intention, physical and chemical activations were carried out. Activated fibers were physically prepared from the carbonization of the Kevlar and its later activation with CO2 and steam of water, by the other hand; the chemically activated fibers were obtained by means of the impregnation of the material with phosphoric acid and their later carbonization. Different conditions were used and preliminary analyses of the precursor were taken into account (TGA-DTA / IR). The resulting fibers were characterized by N2 (77K) adsorption, infrared spectroscopy, SEM, and immersion calorimetry. Yields and Burn off were also evaluated. The results shows that if you want to synthesize activated carbon fibers from Kevlar strong conditions respect to the commonly used such as water steam, high phosphoric acid concentrations and methods of impregnation are the ones who allows the development of optimal surface areas and pore volumes.

The introduction of Mormonism to Finnish society, 1840-1900

This study examines the place of The Church of Jesus Christ of Latter-day Saints (commonly known as the Mormon church) in the Russian Grand Duchy of Finland between the years 1840 and 1900. Attention is put on both the internal workings of the movement and the reactions of society. Theoretical insight is gained through the concepts of social construction and religious economies. Mormon image formation in Finland began by 1840 through newspaper reports on activities abroad and through essays on the faith’s history and doctrine. Mormons are mentioned almost 3,500 times in Finnish newspapers between 1840 and 1900, and at least twelve unique book titles sold in the country were explicitly devoted to discussing Mormonism. Most of the publicity was derived from foreign sources. Discourse analysis of this textual corpus shows a hegemonic discourse that combined themes such as fraud, deception, and theocracy in explaining the Mormon movement. Accompanied by plural marriage, these themes contributed to the construction of a strongly negative image of Mormonism already before the first missionaries arrived in 1875. In a society with a stringently regulated religious economy, this image contributed to a high level of resistance by civil authorities and Lutheran clergy. Twenty-five Mormon missionaries worked in Finland between 1875 and 1900, with a concentrated effort taking place between 1875 and 1889. At least 78 persons converted, mostly in the coastal areas among the Swedish-speaking minority population. Nine percent emigrated to Utah, 36% were excommunicated, others fell into oblivion, while still others clung to their new faith. The work was led from Sweden, with no stable church organization emerging among the isolated pockets of converts. Mormonism’s presence was thus characterized by private or small-group religiosity rather than a vibrant movement. The lack of religious community, conversation, and secondary socialization eventually caused the nineteenth-century manifestation of Finnish Mormonism to die out. Only one group of converts was perpetuated past World War II, after which large-scale proselytizing began.

A tutoria como estratégia educacional no ensino médico

A relação de tutoria é anterior à invenção da linguagem escrita. Desde seu surgimento, ocorreram mudanças em sua estrutura, mas não se perdeu a essência de promover o desenvolvimento do aprendiz. A tutoria é um processo de aprendizado individualizado, numa relação dinâmica, tendo hoje grande importância como ferramenta de ensino em cursos de graduação e treinamentos profissionais. Na educação médica, está relacionada positivamente à percepção de suporte acadêmico, à satisfação com a carreira, à produção científica, à diminuição do risco de burn-out e ao desenvolvimento de relações dentro da profissão. Entretanto, existem limitações, como o pequeno número de tutores preparados, a falta de tempo dos participantes e o restrito apoio institucional. Este trabalho revê os conceitos sobre tutoria, a função dos integrantes e a relação estabelecida entre eles, e avalia a importância, as expectativas e as limitações da tutoria na educação médica, em especial nas escolas de Medicina do Brasil. Foi realizada revisão de artigos científicos do período 2005-2011, no banco de dados PubMed, além de referências citadas nos artigos selecionados.

Metsäkoneen kouran ja hakkuupään pikavaihdon kehittäminen

Yhdistelmämetsäkone on metsäkone, jota voidaan käyttää sekä hakkuukoneena että kuormatraktorina. Konetta voidaan käyttää sekä puiden kaatamiseen, karsimiseen ja katkomiseen että puiden kuormaamiseen ja kuljettamiseen. Tässä diplomityössä suunnitellaan uusi kouran ja hakkuupään pikalukitusmekanismi yhdistelmämetsäkoneen kuormaimeen. Suunnittelutyössä edetään vaiheittain järjestelmällisen tuotesuunnittelun periaatteiden mukaisesti. Tärkeimpänä tavoitteena suunnittelutyönsä on nopeuttaa kouran vaihtoa ja helpottaa kuljettajan työtä. Suunnittelutyön alkuvaiheessa etsitään lukitusmekanismille useita eri ratkaisuvaihtoehtoja, joista valitaan paras jatkokehitykseen. Valittua ratkaisuvaihtoehtoa kehitetään simulointia ja elementtimenetelmälaskentaa apuna käyttäen.