Wave reflection at a free interface in an anisotropic pyroelectric medium with nonclassical thermoelasticity

In this paper, the well-established two-dimensional mathematical model for linear pyroelectric materials is employed to investigate the reflection of waves at the boundary between a vacuum and an elastic, transversely isotropic, pyroelectric material. A comparative study between the solutions of (a) classical thermoelasticity, (b) Cattaneo–Lord–Shulman theory and (c) Green–Lindsay theory equations, characterised by none, one and two relaxation times, respectively, is presented. Suitable boundary conditions are considered in order to determine the reflection coefficients when incident elasto–electro–thermal waves impinge the free interface. It is established that, in the quasi-electrostatic approximation, three different classes of waves: (1) two principally elastic waves, namely a quasi-longitudinal Primary (qP) wave and a quasi-transverse Secondary (qS) wave; and (2) a mainly thermal (qT) wave. The observed electrical effects are, on the other hand, a direct consequence of mechanical and thermal phenomena due to pyroelectric coupling. The computed reflection coefficients of plane qP waves are found to depend upon the angle of incidence, the elastic, electric and thermal parameters of the medium, as well as the thermal relaxation times. The special cases of normal and grazing incidence are also derived and discussed. Finally, the reflection coefficients are computed for cadmium selenide observing the influence of (1) the anisotropy of the material, (2) the electrical potential and (3) temperature variations and (4) the thermal relaxation times on the reflection coefficients

High-resolution stimulated Raman spectroscopy and analysis of v2 and v3 bands of 13C2H4 using the D2h top data system

HRMS 2015, Dijon, France, August 24-28, 2015Peer Reviewe

Satellite-to-satellite attitude control of a long-distance spacecraft formation for the Next Generation Gravity Mission

The paperpresentsthedesignandsomesimulatedresultsoftheattitudecontrolofasatelliteformation under studybytheEuropeanSpaceAgencyfortheNextGenerationGravityMission.Theformation consists oftwospacecraftswhich fly morethan200kmapartatanaltitudefromtheEarth'sgroundof between 300and400km.Theattitudecontrolmustkeeptheopticalaxesofthetwospacecraftaligned with amicroradianaccuracy(pointingcontrol).Thisismadepossiblebyspecific opticalsensors accompanyingtheinter-satellitelaserinterferometer,whichisthemainpayloadofthemission.These sensors alloweachspacecrafttoactuateautonomousalignmentafterasuitableacquisitionprocedure. Pointing controlisconstrainedbytheangulardrag-freecontrol,whichisimposedbymissionscience (Earth gravimetryatalowEarthorbit),andmustzerotheangularaccelerationvectorbelow0.01 μrad/s2 in thesciencefrequencyband.Thisismadepossiblebyultrafine accelerometersfromtheGOCE-class, whose measurementsmustbecoordinatedwithattitudesensorstoachievedrag-freeandpointing requirements.EmbeddedModelControlshowshowcoordinationcanbeimplementedaroundthe embedded modelsofthespacecraftattitudeandoftheformationframequaternion.Evidenceand discussion aboutsomecriticalrequirementsarealsoincludedtogetherwithextensivesimulatedresults of twodifferentformationtypes

An evaluation of the global network of field epidemiology and laboratory training programmes: a resource for improving public health capacity and increasing the number of public health professionals worldwide

BACKGROUND Given that many infectious diseases spread rapidly, across borders and species, there is a growing worldwide need to increase the number of public health professionals skilled in controlling infectious epidemics. Needed also are more public health professionals skilled in non-communicable disease surveillance and interventions. As a result, we surveyed all 57 field epidemiology training programmes (FETPs) that are members of the Training Program in Epidemiology and Public Health Interventions Network (TEPHINET), to evaluate the progress of the FETPs, the only global applied epidemiology network, toward increasing public health capacity globally. METHODS Data on the FETP programmes and the training they provide were abstracted from TEPHINET membership surveys and verified with FETP directors for all FETPs that were members of TEPHINET in 2012. Data on abstracts submitted to the recent TEPHINET Global Scientific Conference, on recent accomplishments by each FETP, and on quality improvement were also compiled to provide a worldwide view of the public health human resource capacity produced by these programmes. RESULTS A total of 6980 public health professionals worldwide have graduated from an FETP or from the Center for Disease Control and Prevention's Epidemiology Intelligence Service (EIS). FETP residents and graduates participate in key public health prevention, control, and response activities. Each FETP has adapted its curriculum and objectives over time to align with its country's public health priorities. FETPs are well integrated into their national public health infrastructures, and they have many partners at the national, regional and global levels. CONCLUSION FETPs are a competent and diverse source of highly skilled public health professionals who contribute significantly to public health's global human resource needs. This finding is evidenced by 1) the training curricula that were adapted over time to meet public health's human resource needs, 2) the FETPs' continued support from internal and external partners, 3) the increasing number of FETP residents and graduates and their increasing contribution to effective public health work, and 4) the increased quality improvement initiatives facilitated through the FETPs membership in one global network, TEPHINET

Evaluación de la biosorción de cobre con cáscara de almendra

En este trabajo se analiza el potencial de la cáscara de almendra para su utilización como biosorbente de cobre presente en disoluciones acuosas. En primer lugar, se realizó una caracterización físico-química del biosorbente. Así, se ha determinado que los poros que posee la cáscara de almendra son mesoporos, con un ancho deporo medio de 54,5 Å y que la cantidad total de grupos activos es de 0,592 mmol/g, siendo el grupo carboxílico el mayoritario. A continuación, se analizó la influencia de las principales variables que intervienen en el proceso de biosorción. Se ha encontrado que el pH es uno de los parámetros más importantes que controlan la eliminación de cobre con cáscara de almendra, obteniéndose la máxima eficiencia del proceso a pH=5. El estudio cinético reveló que, en general, el proceso es rápido, aunque puede dividirse en dos etapas, una primera más rápida (primeros 20 minutos) y otra segunda etapa donde el proceso transcurre de forma más lenta. Se ha encontrado que el modelo de pseudo-segundo orden reproduce de forma adecuada el proceso. Por otra parte, el estudio del equilibrio mostró que a medida que aumenta la concentración inicial de cobre, se eleva la capacidad de biosorción del sólido hasta alcanzar un valor prácticamente constante para concentraciones superiores a 100 mg/L. El modelo de Langmuires el que mejor reproduce los resultados experimentales, obteniéndose una capacidad máxima de biosorción decobre de 9,44 mg/g

A questão do valor na linguagem para (o círculo de) Bakhtin

Pesquisar no pensamento do Círculo de Bakhtin a questão do valor ou axiologia desdobrada na concepção de linguagem constitui o objetivo desta investigação. Reelaborado como pergunta de trabalho, assim pode ser formulada: qual o estatuto do valor em sua relação com a linguagem para o Círculo? Até o presente momento, entre os estudos que se apóiam no pensamento bakhtiniano publicados no Brasil e considerados nesta pesquisa, inexiste um que tenha como foco principal a dimensão axiológica, muito embora a maior parte deles contemple de uma maneira ou de outra as noções com ela imbricada e/ou a ela associadas com intermitência conceitual e terminológica: entonação, entoação, tom emocional-volitivo, tom, tonalidade, índice social de valor, expressividade, apreciação, acento (apreciativo, avaliativo ou de valor), posicionamento valorativo, julgamento de valor, avaliação e ideologia. Considero mais representativas entre eles as análises de Faraco (2006a, 2007a) defendendo que a axiologia é um dos três eixos orientadores da concepção bakhtiniana de linguagem; de Miotello (2007b) e de Ponzio (2008), ambos abordando o valor predominantemente envolto nas discussões sobre ideologia; de Amorim (2006, 2007, 2009), ao chamar a atenção para o enfoque ético; de Sobral (2007a, 2007b, 2007c, 2008, 2009), que destaca as discussões de cunho filosófico; de Souza (1999) contemplando aspectos do valor na linguagem dentro da ―teoria do enunciado concreto‖ e de Tezza (2003), embutida na sua tese sobre a relação poesia-prosa para Bakhtin. É também em Bakhtin, na vertente epistemológica de seu pensamento, que busco orientação para esta pesquisa teórica, cuja característica predominantemente bibliográfica é re-significada nos limites deste trabalho, na medida em que se tenta estabelecer diálogos entre uma parte dos textos do Círculo publicados em português, os textos dos leitores-estudiosos bakhtinianos, principalmente os acima mencionados, e o texto desta dissertação. Por fim, propor uma tarefa cujo principal resultado poderá contribuir para o preenchimento da lacuna apontada justifica esta pesquisa

Effect of wheel track on the density and composition of weeds in a maize crop

El objetivo de este estudio fue analizar si la compactación producida por la rodada del tractor durante las operaciones de siembra influye en la composición y densidad de malas hierbas en cultivo de maíz. Para ello se llevó a cabo el conteo e identificación de las especies presentes en 160 unidades muestrales localizadas en la interlínea de cultivo, de las cuales la mitad estaba afectada por la rodada del tractor y la otra mitad no. El contraste de medias entre los datos con rodada y sin rodada para la riqueza de especies, densidad total y densidad por especies se realizó mediante el test de Mann-Whitney. Los resultados han puesto de manifiesto que las especies principales, a excepción de “Cyperus rotundus”, fueron significativamente más abundantes en las interlíneas con rodada. En relación a la comunidad arvense, ésta fue igualmente más diversa y abundante en las interlíneas con rodada.The aim of this study was to analyze whether the compaction caused by the tractor during sowing operations affects the composition and density of the weed flora in maize crops. For that, 160 sample units were taken in the crop interline, where half of them were affected by the tractor tread and the other half not. In each sampling unit we carried out the count and identification of weed species. The Mann-Whitney test was performed to contrast differences in species richness, total and individual species densities between tractor-tread and not tractor-tread data. The results revealed that the main species, except for “Cyperus rotundus” were significantly more abundant in the interline with tractor tread. In relation to the weed community, it was also more diverse and abundant in the interline with tractor tread

Chemical Characterization and Source Apportionment of Household Fine Particulate Matter in Rural, Peri-urban, and Urban West Africa

Household air pollution in sub-Saharan Africa and other developing regions is an important cause of disease burden. Little is known about the chemical composition and sources of household air pollution in sub-Saharan Africa, and how they differ between rural and urban homes. We analyzed the chemical composition and sources of fine particles (PM2.5) in household cooking areas of multiple neighborhoods in Accra, Ghana, and in peri-urban (Banjul) and rural (Basse) areas in The Gambia. In Accra, biomass burning accounted for 39–62% of total PM2.5 mass in the cooking area in different neighborhoods; the absolute contributions were 10–45 μg/m3. Road dust and vehicle emissions comprised 12–33% of PM2.5 mass. Solid waste burning was also a significant contributor to household PM2.5 in a low-income neighborhood but not for those living in better-off areas. In Banjul and Basse, biomass burning was the single dominant source of cooking-area PM2.5, accounting for 74–87% of its total mass; the relative and absolute contributions of biomass smoke to PM2.5 mass were larger in households that used firewood than in those using charcoal, reaching as high as 463 μg/m3 in Basse homes that used firewood for cooking. Our findings demonstrate the need for policies that enhance access to cleaner fuels in both rural and urban areas, and for controlling traffic emissions in cities in sub-Saharan Africa

Ionizing Radiation Effects on Food Vitamins - A Review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Ionizing radiation has been widely used in industrial processes, especially in the sterilization of medicals, pharmaceuticals, cosmetic products, and in food processing. Similar to other techniques of food processing, irradiation can induce certain alterations that can modify both the chemical composition and the nutritional value of foods. These changes depend on the food composition, the irradiation dose and factors such as temperature and presence or absence of oxygen in the irradiating environment. The sensitivity of vitamins to radiation is unpredictable and food vitamin losses during the irradiation are often substantial. The aim of this study was to discuss retention or loss of vitamins in several food products submitted to an irradiation process.52512671278Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES