Compressive and splitting tensile strength of autoclaved aerated concrete (AAC) containing perlite aggregate and polypropylene fiber subjected to high temperatures
This paper presents the results of an experimental study on the residual compressive and splitting tensile strength of autoclaved aerated concrete (AAC) containing perlite and polypropylene (PP) fiber subjected to high temperatures. Cylinder specimens were subjected to various temperature ranges of 100, 200, 400, 800, and 1,000°C. The mixtures were prepared with AAC cementitious materials containing perlite at 15%, 20%, and 30% sand replacement. The polypropylene fiber content of 0, 0.5%, 1%, 1.5%, and 2% by volume was also added to the mixture. The results showed that the unheated compressive and splitting tensile strength of AACs containing PP fiber were not significantly higher than those containing no PP fiber. Furthermore, the presence of PP fiber was not more effective for residual compressive strength than splitting tensile strength. The 30% perlite replacement of sand gave the highest strength. Based on the results, it can be concluded that addition of PP fiber did not significantly promote the residual strength of AAC specimens subjected to high temperatures.
Effects of the Composition and the Preparation Methods on Oil Sorption Capacity of Recycled Rayon Waste-Kapok Mixtures (RRWK) Sorbent
The aim of this study was to investigate the utilization of a recycled rayon waste-kapok mixtures as an oil sorbent for the removal of diesel, motor oil and bunker C. The effects of the kapok fibers: rayon fibers ratio and the additional of sodium sulfate on RRWK sorbents properties were investigated through series of oil sorption tests. The ASTM 726-06 method was used to determine the oil sorption capacity of the sorbents under both static and dynamic conditions. The results showed the high sorption capacity of the recycled rayon waste-kapok mixture for difference kinds of oil. Oil, which has a high viscosity, tends to have a higher oil sorption ratio. RRWK sorbents had higher oil sorption capacity than commercial polypropylene. The presence of kapok fibers in RRWK increases the hydrophobicity and oil sorption capacity of the sorbents while the presence of rayon fibers improves the strength of the sorbents. The additional of sodium sulfate during sorbent preparation increases the surface area and pore size of RRWK sorbent and thus improves the oil sorption capacity. It can be concluded that RRWK, which can be produced by utilizing industrial waste, is effective low cost, environmentally friendly oil sorbent with comparable performance to commercial products.
Morphological characterization of Eustrongylides sp. larvae (Nematoda, Dioctophymatoidea) parasite of Rhinella marina (Amphibia: Bufonidae) from Eastern Amazonia.
Absctract Eustrongylides spp. nematodes have birds as final hosts and uses other vertebrates as intermediate/paratenic host (fish, amphibians and reptiles) and have zoonotic potential. In amphibians, the larvae may be located in the subcutaneous tissues, liver and mesentery, between the muscle fibres, especially in the lower limbs. Rhinella marina, which is widely observed in Brazil, has exhibited complex diversity in its helminth fauna, reflecting the unique habitat of the Amazon biome. For the first time, this study describes the morphological aspects of third-stage larvae of Eustrongylides sp. in Rhinella marina from Santa Cruz do Ararí, Marajó Archipelago, Eastern Amazonia, using light and scanning electron microscopy.