Decompression procedures for the safe ascent of aerospace personnel from ground level to altitude, supplement B Final report

Repetitive diving/flying decompression table for safe ascent to cabin pressure altitude

Área experimental silvipastoril no sul do Paraná.

bitstream/item/101190/1/PA-1983-Schreiner-AreaExperimental.pd

Performance characteristics and design recommendations for biomass-burning stoves using earthen construction materials

This report provides an analysis of the thermal performance and emissions characteristics of improved biomass stoves constructed using earthen materials. Commonly referred to as mud stoves, this type of improved stove incorporates high clay content soil with an organic binder in the construction of its combustion chamber and body. When large quantities of the mud material are used to construct the stove body, the stove does not offer significant improvements in fuel economy or air quality relative to traditional open fire cooking. This is partly because a significant amount of heat is absorbed by the mass of the stove reducing combustion efficiency and heat transfer to the cook pot. An analysis of the thermal and mechanical properties of stove materials was also performed. A material mixture containing a one‐to‐one ratio by volume of high content clay soil and straw was found to have thermal properties comparable to fired ceramics used in more advanced improved stove designs. Feedback from mud stove users in Mauritania and Mali, West Africa was also collected during implementation. Suggestions for stove design improvements were developed based on this information and the data collected in the performance, emissions, and material properties analysis. Design suggestions include reducing stove height to accommodate user cooking preferences and limiting overall stove mass to reduce heat loss to the stove body

THE EFFECTS ON PEASANT HOUSEHOLDS OF ACCESS TO FORMAL DEPOSITS AND LOANS

A dynamic, stochastic, rational expectations model of a peasant household with access to deposits and loans (up to a credit limit) is solved and simulated. If formal contracts offer more favorable rates than informal contracts, then access to formal contracts increases average consumption and decreases its standard deviation.Agricultural Finance, Consumer/Household Economics,

Hybrid sol-gel coatings containing clay nanoparticles for corrosion protection of mild steel

The development of a new environment-friendly anticorrosive coating for mild steel substrate is afforded in this work. The combined use of cerium, as a self-healing agent, and clay nanoparticles, as improvers of the barrier properties, was considered to the development of new anticorrosive sol-gel coatings. Nanostructured hybrid films were synthesized by the sol-gel route from tetraethoxysilane (TEOS) and 3-glicidoxipropyl-trimetoxisilano (GPTMS) using laminar nanoclays (Laponite Na+0.7[Si8Mg5.5Li0.3H4O24]−0.7) to improve mechanical and barrier properties, and Ce(NO3)3?6H2O as a supplier of Ce(III) to provide an inhibiting effect in the event of coating failure. Carbon steel plates, AISI 1010, were used as substrates. Prior to the application of the coating, samples were treated with a phosphoric acid 2% v/v in order to improve coating adherence.In order to evaluate cerium effect, electrochemical behaviour of films containing Laponite and cerium salts (TGL-Ce) were compared with films containing only Laponite (TGL) by means of potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) measurements using a 0.35 wt% NaCl solution. Microstructural characterization and surface analysis of substrates and sol-gel coatings were performed by optical microscopy and by XPS techniques. The use of nanoclays allowed to achieve a significant improvement of the anticorrosive behaviour of the cerium doped coating at the same time that enhances the physical integrity of the coatings under immersion tests.Fil: Santana, Ianina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Pepe, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Schreiner, Wido H.. Universidade Federal do Paraná; BrasilFil: Pellice, Sergio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ceré, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Culturas intercalares de milho (Zea mays L.) em reflorestamentos de Pinus taeda L. no sul do Paraná.

Este trabalho foi planejado com o objetivo de se avaliar, na região dos Campos Gerais do Paraná, o rendimento de associações de Pinus taeda L. com milho (Zea mays L.), em função de três densidades populacionais desta cultura: 50 mil, 67 mil e 83 mil plantas/ha, dispostas, respectivamente, em duas, três e quatro linhas, entre as linhas do Pinus plantado no espaçamento de 3 x 2 m. O plantio do Pinus e o da primeira cultura de milho foram efetuados no ano agrícola 1981/82; duas novas culturas de milho foram plantadas em 1982 e em 1983. Até a terceira colheita do milho, não se registraram diferenças entre as sobrevivências do Pinus associado com duas, três e quatro linhas do cereal, nem entre estas e as da testemunha sem consórcio (média de 91,33%). Quanto à altura e ao diâmetro da espécie florestal, no entanto, os incrementos registrados no consórcio com quatro linhas de milho (3,65 m e 5,73 cm) foram menores que na testemunha sem consórcio (4,17 m e 6,92 cm), enquanto que nos consórcios com duas e três linhas, estes ficaram em posição intermediária. As produções de milho, no primeiro e no segundo ano, propiciaram, respectivamente, retornos sobre o capital investido nesta cultura, da ordem de 135 e 94%. Já no terceiro ano, quando o desenvolvimento do Pinus tornou-se suficiente para sombrear parcialmente a cultura agrícola, sua produção foi deficitária, embora em pequeno grau. A população de 50 mil plantas de milho por hectare, dispostas em duas linhas, entre as linhas do Pinus, mostrou-se a mais indicada para o sistema

RACIAL DISCRIMINATION IN HIRE/PURCHASE LENDING IN APARTHEID SOUTH AFRICA

A partial-observability model finds evidence of racial discrimination by retailers of consumer durables in apartheid South Africa. In particular, black households are 13 percentage points more likely to demand a hire/purchase loan but not to have one supplied than are other households, all else equal.Consumer finance, disequilibrium models, racial discrimination, truncated and censored models, South Africa, Financial Economics,