This paper present a study to apply the X-ray densitometry technique in obtaining density profiles, along the thickness of new composites made from eucalyptus fibers and sugarcane bagasse particles. Experimental panels were made in treatments with different percentages of both raw materials and bonded with two urea formaldehyde resin percentages, 13% and 16%, with target density of 750 kg m-3, obtaining density profiles and qualitative variables of maximum, medium and minimum densities. The results indicated that the dosage of resin at 16% promoted greater homogeneity in the profile formats and statistical similarity between the minimum density values in the different treatments, which refers to performance as to the internal bond. The density profiles along the thickness showed variations of the panel frame and provided important quality information, applied to the press cycle setting and indications of its technological performance, expanding the possibilities of raw material parameter diagnosis and the panel manufacturing processes.

The purpose of this stage was to determine the influence of particle size and shape of peanut husks on the properties of panels made with urea resin. Panels were made with milled husks (r: 200 Kg/m³) and unmilled husks (r: 81 Kg/m³) and two combinations thereof. The results showed that the panels made with milled husks improved physical and mechanical properties with respect to the panels that incorporated unmilled particles. The density values in panels with milled particles were 628.67 Kg / m³; water absorption 65.3% and 79.75% at 2 and 24 hours respectively, and swelling of 9.9% and 14.35% measured at 2 and 24 hours respectively. Regarding the characterization of mechanical properties of bending, the values recorded in samples prepared with fine particles of peanut husks resulted in MOR: 3.58 MPa, LOP 2.26 MPa and MOE 627 MPa. With respect to toughness, the highest value was observed in particle boards made from unmilled peanut husks: 1.58MPa. The characterized properties are still below the properties of commercial wood panels. Adjustments to the process of preparing the peanut husks plates will be incorporated in future experiences.

El propósito de esta etapa de investigación fue conocer la influencia del tamaño y forma de partículas de cáscaras de maní en propiedades de paneles aglomerados con resina ureica. Se formularon paneles con cáscaras molidas (r: 200 Kg/m³), paneles con cáscaras enteras (r: 81 Kg/m³) y dos combinaciones de las mismas. Los resultados demostraron que paneles compuestos por partículas de cáscaras de maní molidas (finas) mejoraron propiedades físicas y mecánicas respecto de las placas que incorporaron partículas de mayor tamaño. Los valores de densidad en paneles con partículas molidas fueron 628,67 Kg/m³; absorción de agua 65,3% y 79,75% a 2 h y 24 h respectivamente; e hinchamiento de 9,9% y 14,35% a 2 h y 24 h respectivamente. En relación a propiedades mecánicas de flexión, resultaron con módulo de ruptura (MOR) 3,58 MPa, límite de proporcionalidad (LOP) 2,26 MPa y módulo elástico (MOE) 627 MPa. Con respecto a tenacidad (T), el mayor valor fue observado en los tableros elaborados con partículas enteras: 1,58 MPa. De acuerdo a los valores de densidad, las propiedades caracterizadas se encuentran por debajo de las correspondientes para placas comerciales de madera. Ajustes al proceso de elaboración de paneles de cáscaras de maní serán incorporados en futuros trabajos.

Este trabalho tem por objetivo a caracterização de diferentes massas cerâmicas do estado de S. Paulo para a produção de agregados leves de argila calcinada visando à utilização em concretos de cimento Portland. A caracterização das massas cerâmicas deu-se por meio das técnicas de limites de liquidez e plasticidade, análise granulométrica, análise química e difração de raios X. Os corpos de prova confeccionados com essas massas cerâmicas, queimados a 900 ºC, foram caracterizados por meio da avaliação da retração linear, absorção de água, porosidade aparente, massa específica aparente, expansão por umidade e resistência à compressão. Os resultados desta pesquisa indicaram a viabilidade da produção de agregados leves de argila calcinada para utilização em concretos e os valores da massa específica (1,555 a 1,785 kg/m³) e da resistência à compressão (18,0 a 55,8 MPa) apresentaram-se em um patamar intermediário entre os observados para a argila expandida (agregado leve comercial) e para o agregado convencional (basalto).

This paper aims the characterization of different S. Paulo state ceramic material for the production of calcined Clay lightweight aggregates in order to use in Portland cement concretes. The characterization of ceramic material was made by techniques of liquid and plasticity limits, particle size analysis, chemical analysis and X-ray diffraction. The specimens made from these ceramic materials, burned at 900 ºC, were characterized by evaluating of linear shrinkage, water absorption, apparent porosity, specific mass, moisture expansion and compressive strength. Results of this research indicated the viability of production of calcined clay lightweight aggregate for use in concrete and the values of specific mass (1.555 to 1.785 kg/m³) and compressive strength (18.0 to 55.8 MPa) presented at a intermediate level between those observed for the expanded clay (commercial lightweight aggregate)and the conventional aggregate (basalt).

This study aimed at evaluating the thermal performance of a modular ceiling system for poultry houses. The reduced- and distorted-scale prototypes used ceiling modules made of reforested wood and were covered with recycled long-life package tiles. The following parameters were measured for 21 days: tile internal surface temperature (ST), globe temperature and humidity index (WBGT), and radiant heat load (RHL). Measurements were made at times of highest heat load (11:00 am, 13:00 pm, and 03:00 pm). Collected data were analyzed by "R" statistics software. Means were compared by multiple comparison test (Tukey) and linear regression was performed, both at 5% significance level. The results showed that the prototype with the ceiling was more efficient to reduce internal tile surface temperature; however, this was not sufficient to provide a comfortable environment for broilers during the growout. Therefore, other techniques to provide proper cooling are required in addition to the ceiling.