Abstract Civil construction generates the largest amount of construction and demolition waste (CDW), most of which is not reused and is discarded as inert waste in landfills. The purpose of this study was to evaluate the feasibility of reusing gypsum recovered from CDW in the preparation of mortar. This material was examined to determine its specific mass, morphology, elemental composition and particle size distribution. Test specimens were prepared with a mix design of 1:3 (cement:sand), with the gypsum waste substituting part of sand in proportions of 0, 10, 20 and 30% (in volume). The consistency of the fresh mortar was evaluated: the specimens were tested to determine their flexural and compressive strength, apparent density, water absorption, voids index, and specific mass. After 28 days, the mechanical strength of the specimens exceeded the limits specified by NBR 13281 standard, indicating that up to 30% of ground gypsum waste can be included in a mortar.

O efeito da serotonina e da monoablação do pedúnculo ocular na indução do desenvolvimento gonadal de Penaeus penicillatus (camarão do rabo vermelho) foi investigado. Fêmeas imaturas com peso médio de 20 g foram selecionadas e distribuídas de maneira aleatória em quatro grupos de 5 animais com uma réplica para cada grupo: grupo controle inicial (CI), sacrificado no 1º dia do experimento; grupo controle paralelo (GC), injetado com 0,05 ml de solução salina; grupo monoablado (GA), submetido à monoablação no dia 0 e injetado com 0,05 ml de solução salina logo após a monoablação e no 5º dia; grupo serotonina (GS), injetado com 0,05 ml de serotonina dissolvida em solução salina no dia 0 e 5º dia, numa dose total de 15 mg por grama de peso do animal (7,74 x 10-7 mol). Os animais do grupo controle inicial (CI) foram sacrificados no dia 0, e no 5º, 10º e 15º dias para os demais grupos, respectivamente. Fragmentos dos lóbulos anteriores das gônadas dos animais foram fixados em Bouin aquoso e processados com as técnicas usuais de microscopia óptica. As análises consistiram na descrição morfológica das células e na medida do diâmetro dos ovócitos, evidenciando um papel estimulador da serotonina e da monoablação sobre a maturação gonadal. A análise estatística (Anova - SNK, P < 0,05) dos valores de diâmetro dos ovócitos mostrou ser a monoablação mais efetiva na indução da maturação ovariana que a serotonina na concentração utilizada (7,74 x 10-7 mol).

The effects of serotonin and of the monoablation of eyestalk on the induction of gonadal development of Penaeus penicillatus (red tail shrimp) were investigated. Immature females with an average weight of 20 g were selected and ramdonly distributed into four groups of 5 animals as follows: initial control group (IC), sacrificed at the 1st day of the experiment; parallel control group (CG), injected with 0.05 ml of saline solution; monoablated group (AG), submitted to monoablation at day 0 and injected with 0.05ml of saline immediatelly after the monoablation and on the 5th day; serotonin group (SG), injected with 0.05 ml of serotonin, dissolved in saline solution, both on day 0 on the 5th day, in a total dose of 15 mug per gram of animal's weight (7,74 x 10 -7 mol). Animals were sacrificed on day 0 for the initial control group (IC), and on the 5th, 10th and 15th days for the other groups. A fragment from the front lobe of the animal's gonad was fixed in aqueous Bouin and processed with the usual optic microscopy techniques. Analyses consisted of a morphological description of cells and measurements of the diameter of oocytes, which gave evidence to the stimulating role of serotonin and of monoablation on gonad maturation. The statistical analysis (Anova -SNK, P < 0.05) of the diameter values of oocytes showed monoablation to be more effective in inducing ovary maturation than serotonin at the concentration used (7,74 x 10-7 mol).