ABSTRACT Pilot-scale test stations make it possible to obtain reliable and comparable results applicable to full–scale systems by conforming to specified proportional limits. Therefore, in this study, normal and frictional pressures were evaluated in a pilot-scale test station composed of a slender cylinder silo using maize, a free-flowing product, as the stored product. Temporal effects were analyzed and verified during filling, static, and discharge conditions. The maximum normal and frictional pressures were also evaluated. The results were compared with ISO 11697: 1995. During filling, accommodation peaks occurred only in the α: 30° hopper. In general, normal pressures were higher for the flat bottom whereas higher frictional pressures occurred for the 30° hopper. The maximum experimental pressures (normal and frictional) were lower than those provided by ISO 11697. Therefore, it is concluded that the coefficients used in the ISO standard are sufficient to promote safety in silo projects.

ABSTRACT The need for treated water is essential for life. With the constant increase in population, the most common way to purify surface water is through conventional water treatment plants (WTPs). The high volume of residue (sludge) generated in this process is most often returned to the catchment site, negatively affecting the ecosystem. The sludge of WTPs is similar to soil because it is composed of inorganic solids. Adobe is a construction material made from water and soil without the burning process, so it is considered sustainable, recyclable, and energy-efficient and can be stabilized with various materials. Therefore, the objective of this work is to develop adobes using the sludge of WTPs and to analyse their physical, mechanical and thermal properties. Adobes were produced with five concentrations of sludge by mass: 0, 1, 3, 5 and 7%. It was observed that with the increase in the sludge concentration, there was an increase in the capillarity and a decrease in mass, the water absorption was limited to 3% of sludge, and there was an increase in the bulk density. The linear shrinkage, thermal conductivity and compressive strength were not influenced. The addition of WTP sludge altered some properties of adobe. The use of WTP sludge in adobe is limited to 3%; above that, the adobe becomes unstable in relation to water. Therefore, the use of WTP sludge in the manufacture of adobe is feasible in controlled concentrations and is a sustainable use of the residue.

ABSTRACT Adobe is an efficient construction material for several reasons, such as its thermal comfort, sustainability, and lower energy cost, as well as the simplicity of its production and execution. However, challenges such as water absorption, capillarity, and compressive strength should be investigated to improve its physical and mechanical properties. “Synthetic termite saliva” (STS) is an excellent stabilizer with high cohesive and hydrophobic power. Therefore, the objective of this work was to evaluate the effects of STS incorporation into adobe, analyzing its physical, mechanical and thermal properties. Five treatments were studied: 0 (control); 0.1; 0.2; 0.4 and 0.8% STS by mass. These adobe samples were evaluated according to bulk density, linear shrinkage, capillarity, water absorption, thermal conductivity and compressive strength, according to Norma Técnica de Edificación (NTE) E0.80 testing using a new methodology. Linear shrinkage decreases from 2.7 to 1.91 cm with 0.4% STS. Capillarity decreases with the increasing amounts of STS. Water absorption decreased from 12.03 to 6.31% using 0.4% STS, and its mass was reduced from 779 to 19 grams. The thermal conductivity showed no differences between concentrations. The compressive strength was reduced but was still acceptable based on NTE E.080. The stabilization of the adobe using STS showed an improvement in its physical properties, mainly due to its hydrophobic power.

ABSTRACT The most important parameter in terms of material mechanical behavior knowledge is the modulus of elasticity, being traditionally obtained through destructive tests. The objective of this study is the verification of the potential use of the particle image velocimetry technique (PIV) as a tool to obtain the modulus of elasticity in sawed wood samples (Pinus oocarpa and Eucaliptus grandis) and wood panels (Plywood, LVL and OSB). The PIV technique has as characteristics the low cost of equipment, fast results, no need for contact with the object tested, accuracy and possibility of application in the field. The application of the PIV technique occurred during the static bending tests where the deformations were also measured with a dial indicator (conventional method), thus obtaining comparative measurements. From the load values applied by a universal test machine and deformation values obtained by the dial indicator and PIV techniques, it was possible to calculate the modulus of elasticity through both methods. With the “Student's t” statistical test application with significance level of 1%, it was verified that the modulus of elasticity found by the PIV technique and the dial indicator were statistically equal. Average values for the modulus of elasticity found were respectively for the use of the conventional method and for the PIV method the values of: 13,077 and 13,027 MPA for Eucalyptus grandis; 6,171.6 and 6,418.8 MPa for Pinus oocarpa; 10,481.2 and 11,094.3 MPa for plywood; 8,687.4 and 10,261.0 MPa for the LVL; and 2,480.1 and 2,899 MPa for the OSB. It was concluded that the PIV technique is capable of measuring modulus of elasticity values with similar precision to the test techniques traditionally used for this purpose.

A sigatoka-negra (Mycosphaerella fijiensis) é a doença de maior severidade que afeta as cultivares de banana (Musa spp.) de importância econômica no mundo. Foi constatada no Brasil em 1998, no Estado do Amazonas, e tem se disseminado pelo Estado do Acre, atacando severamente as cultivares do Subgrupo Terra (AAB). Realizou-se um diagnóstico da sigatoka-negra e dos impactos econômicos causados por esta doença nos municípios do Estado do Acre. Foram visitados plantios em 16 municípios e amostras de folhas de bananeiras com sintomas característicos da doença foram coletadas para diagnóstico. Verificou-se que a sigatoka-negra estava presente em todos os municípios visitados. As conseqüências econômicas da doença podem ser evidenciadas pela redução de 42% na produção total de banana do Estado do Acre no período de 2000/2001, enquanto o valor da produção foi reduzido em 47% no ano de 2001, com repercussão nos diversos segmentos da cadeia produtiva. Nesse aspecto, observou-se que os municípios de Plácido de Castro e Acrelândia, foram os mais afetados pela sigatoka-negra.

Black sigatoka (Mycosphaerella fijiensis) is the most severe disease affecting banana (Musa spp.) cultivars in terms of economic importance in the world. It was verified in Brazil in 1998, in the state of Amazonas, and has since spread throughout the state of Acre, severely attacking the cultivars of the Subgroup Plantain (AAB). This study was performed to diagnosis the occurrence of black sigatoka and the economic impact caused by the disease in the municipal districts of Acre. Visits to 16 municipal districts were made and samples of banana leaves with characteristic symptoms of the disease were collected for diagnosis. Black sigatoka was verified to be present in all municipal districts visited. The economical consequences of the disease are shown in a 42% reduction in total banana production in the State of Acre between 2000 and 2001, while the banana production fell another 47% in 2001, creating repercussions for diverse segments of the productive chain. Plácido de Castro and Acrelândia municipal districts were observed to have suffered the worst effects of black sigatoka.