Morphology and Photoluminescence of HfO2 Obtained by Microwave-Hydrothermal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Energy method to calculate the density of liquids using ultrasonic reflection techniques

In this work it is introduced a new approach to calculate the density of liquids in terms of the energies of the acoustic signals. This method is compared to other methods in the time domain (peak-to-peak amplitudes) and frequency domain magnitudes at a single frequency. It is used a measurement cell based on a multiple reflection technique, and it is developed an acoustic model for the cell. Simulations and experiments using several liquids are presented, showing that the energy method a less sensitive to noise than the other techniques. The relative errors in the density are smaller than 0.2% when compared to the values measured with a pycnometer.

Indoor radon measurements in six Latin American countries

Most of the natural radiation dose to man comes from radon gas and its progeny. Several countries have established national institutions and national programs in charge of the study of radon and its connection with lung cancer risk and public health. In this paper an indoor radon measurements in Latin American countries is presented. The participants in this work were from Argentina, Brazil, Ecuador, Mexico, Peru and Venezuela. Many different techniques are used in this common effort, and the indoor radon levels in specific locations in each of the participant countries are presented.

Relation between the compaction rate and physical and mechanical properties of particleboards

The compaction rate, the relation between the density of the wood panel and the density of the wood used for producing the particles, is an indicator of the product's densification. Among the various types of wood panels, particleboards are widely employed in the lumber industry, mainly for the furniture production. This paper presents a study of the relation between the compaction rate and the properties of tensile strength perpendicular to surface, Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) obtained from a static bending test, thickness swelling and water absorption (2 and 24 hours). These properties were calculated according to the Brazilian ABNT, NBR 14810 standard. Particleboards were produced using the species Pinus elliotti and adhesive ureaformaldehyde. The relation was established by a multiple linear regression, and the most appropriate statistical models were determined. The estimated models indicate statistically significant effects of water absorption in 2 hours and MOR in the particleboards' compaction rate.

Reliability of timber bridges using nailed plywood box beams

The Nailed Box Beam structural efficiency is directly dependent of the flange-web joint behavior, which determines the partial composition of the section, as the displacement between elements reduces the effective rigidity of the section and changes the stress distribution and the total displacement of the section. This work discusses the use of Nailed Plywood Box Beams in small span timber bridges, focusing on the reliability of the beam element. It is presented the results of tests carried out in 21 full scale Nailed Plywood Box Beams. The analysis of maximum load tests results shows that it presents a normal distribution, permitting the characteristic values calculation as the normal distribution theory specifies. The reliability of those elements was analyzed focusing on a timber bridge design, to estimate the failure probability in function of the load level.

Reglas de juego para las negociaciones agropecuarias de un TLC con Estados Unidos

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Visión agrícola del TLC entre Colombia y Estados Unidos: preparación, negociación, implementación y aprovechamiento

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Análisis del Acuerdo de Asociación entre Colombia y la Unión Europea: agricultura y medidas sanitarias y fitosanitarias

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Alternativas para reducir la discriminación y la segmentación por riesgo en el sistema de salud chileno

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Un matrimonio difícil: la convivencia entre un seguro público solidario y seguros de salud competitivos

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Las metas del Milenio y la igualdad de género: el caso de Guatemala

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Honduras: una aproximación a la situación de las mujeres a través del análisis de los indicadores de género

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Las metas del Milenio y la igualdad de género: el caso de Nicaragua

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Instrumentos para la toma de decisiones en políticas de seguridad vial en América Latina: el índice de seguridad de tránsito (INSETRA)

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Bats (Mammalia: Chiroptera) from Guarulhos, state of São Paulo, Brazil

The present study provides a record of the bat fauna captured in Guarulhos, state of São Paulo, Brazil, between February and November 2011. The capture sessions were carried out using mist nets set on trails, around and above streams and lakes, near built areas and around livestock. After a total effort of 26,208 m2.h, we recorded 17 bat species belonging to Phyllostomidae (13 species), Vespertilionidae (3) and Molossidae (1). Sturnira lilium (73 captures), Artibeus fimbriatus (69), and A. lituratus (59) were the most abundant species, corresponding to 57.8% of all captures. Some information about shelters was also commented. This paper is the first to report Molossops neglectus for Guarulhos. © 2012 Check List and Authors.