Abstract: Effect of compression casting technique on the water absorption characteristics of low grade 100% Recycled Aggregate Concrete (RAC) of target strength range 11 to 15 MPa to be used in the manufacturing of masonry units is investigated. Water absorption characteristics were determined by performing sorptivity test. Recycled aggregates were produced by crushing laboratory-tested concrete samples of strength ranging from 21 MPa to 28 MPa. Two different ratios of recycled coarse aggregate and recycled fine aggregates were investigated using two different cement contents. For comparison, natural aggregate concrete mixes were also tested. The study parameter included effect of aggregates type, casting pressure, casting technique and cement content on the water absorption properties of RAC. Further, depth of penetration of salt was observed using silver nitrate solution after 3-month immersion in 10% NaCl solution. The results of sorptivity test showed positive impact of compression casting technique on water absorption properties of low grade 100% RAC. Further, results showed that RAC mixes exhibited inferior water absorption properties compared to natural aggregates concrete mixes. Various equations were proposed to predict water absorption of 100% RAC under different conditions of casting pressure and cement content based on initial and secondary rate of water absorption.

RESUMO O potencial do extrato de curcuma e suas frações químicas foram avaliados para controlar a infestação da mosca do pêssego, Bactrocera zonata em um ensaio biológico à base de mortalidade. O extrato de cúrcuma (EC) foi obtido por aparelho de extração de Soxhelt e quimicamente fracionado em seis frações (F1 ... F6) por cromatografia em camada fina e cromatografia em coluna. Cinquenta pares de moscas acondicionadas em gaiolas foram alimentadas com 250 e 500 ppm de EC e suas frações, em separado, durante 20 dias, juntamente com moscas não alimentadas com a dieta para servir de controle. A toxicidade de EC e cada uma das suas fracções foi avaliada calculando a porcentagem de mortalidade de cada população de moscas, a cada 5 dias, em 4 intervalos consecutivos. A mortalidade de população de moscas foi, positivamente, correlacionada com as concentrações de EC e suas frações na dieta. A mortalidade das moscas alimentados em 250 e 500 ppm de EC foi, significativamente, maior em 44,17 e 66,33% em comparação com 28,88% no controle. A mortalidade foi maior no caso de moscas alimentadas com as frações F1, F3 e F6, ou seja, 72,22%, 50,00% e 48,76% respectivamente. O aumento máximo da mortalidade foi observado no final do terceiro intervalo; no caso de moscas alimentadas a 500 ppm de EC, 52,45% de mortalidade foi observada no final do terceiro intervalo. A maior mortalidade foi causada pelas frações F1, 51,39% no caso das moscas alimentadas com 250 ppm e 70,37%, no caso daqueles alimentadas com 500 ppm.

ABSTRACT Potential of turmeric extract and its chemical fractions were evaluated to control the infestation of Bactrocera zonata peach fruit fly in a mortality-based bioassay. The turmeric extract (TE) was taken on Soxhelt's extraction apparatus and chemically fractioned by thin layer followed by column chromatography into 6 fractions (F1 ...F6). Fifty pairs of the flies were fed in cages with 250 and 500 ppm TE and its fractions separately for 20 days along with flies fed on untreated diet to serve as control. The toxicity of TE and each of its fractions was evaluated by calculating percent mortality of fly population after every 5th day in 4 consecutive intervals. Mortality of fly population was observed to be positively correlated with increasing concentrations of TE and its fractions in diet. The mortality of flies fed at 250 and 500 ppm TE was significantly higher at 44.17 and 66.33% compared to 28.88% in control. Percent mortality was much higher in case of flies fed with fractions F1, F3 and F6 i.e. 72.22, 50.00 and 48.76 respectively. Maximum rise of mortality was observed at the end of 3rd interval; in case of flies fed at 500 ppm TE, 52.45 percent mortality was observed at the end of 3rd interval; highest mortality was caused by fraction F1, 51.39% in case of flies fed at 250 ppm and 70.37% in case of those fed at 500 ppm.