Impact strength and abrasion resistance of high strength concrete with rice husk ash and rubber tires

The paper discusses the application of High Strength Concrete (HSC) technology for concrete production with the incorporation of Rice Husk Ash (RHA) residues by replacing a bulk of the material caking and rubber tires with partial aggregate volume, assessing their influence on the mechanical properties and durability. For concrete with RHA and rubber, it was possible to reduce the brittleness by increasing the energy absorbing capacity. With respect to abrasion, the RHA and rubber concretes showed lower mass loss than the concrete without residues, indicating that this material is attractive to be used in paving. It is thus hoped that these residues may represent a technological and ecological alternative for the production of concrete in construction works.

Popping expansion and yield responses of popcorn cultivars under different row spacings and plant populations

The objective of this work was to evaluate the agronomic traits and the popping expansion index of three Brazilian popcorn cultivars under different row spacings and plant populations. The trials were performed during two crop seasons, under field conditions. The experimental design used was a randomized complete block, in a split-split plot, with 27 treatments and four replicates. Treatments were represented in a triple factorial arrangement: three row spacings (0.40, 0.60, and 0.80 m), three plant populations (40,000, 60,000, and 80,000 plants per hectare), and three popcorn cultivars (IAC-TC 01, IAC 12, and Zelia). The increase in plant population causes a reduction in the number of grains per ear, lower prolificacy, and grain weight loss. Cultivar grain yield is affected by row spacing and popcorn plant population. Cultivar IAC 12 shows highest grain yield under row spacings of 0.40 and 0.60 m and plant population between 60,000 and 80,000 plants per hectare. The popping expansion index is not affected by row spacing or plant population.

Desgaste das facas do corte basal na qualidade da colheita mecanizada de cana-de-açúcar

During the sugarcane mechanized harvester process, the wear of base cutting knives is directly correlated to the quality of the cut made by the machines, and the use of quality control tools important in monitoring this process. Thus, the present study in Ribeirão Preto region aimed to assess the knives cut baseline and damage caused to wear brass knuckles in mechanized harvesting of cane raw sugar, from the viewpoint of statistical quality control (SQC). The wear of the knives was quantified by mass loss and its dimensions, while cutting quality was assessed by cutting height and damage to stumps visually classified according to the level of damage caused. The results showed that the wear of the knives was more pronounced in certain periods of use, but still within control standards. The cutting height was not affected by the wear of the knives, keeping within the limits of desirable quality for operation. Eventually damage the stumps ranged among themselves depending on each face of the cutting knives evaluated, and the predominance of certain classes of damage in each cutting face, but always remained in statistical control.

Ácido cítrico e quitosana na conservação de lichias 'Bengal'

The aim of this study was to evaluate citric acid application with or without chitosan on the maintenance of the quality of litchi 'Bengal'. It was used litchi on mature maturation stage. After selection, fruits were immersed for one minute on the solution of citric acid and chitosan: [1]Control - without immersion; [2] citric acid 300g L-1, [3] citric acid 300 g L-1 + chitosan 0,3%, [4]citric acid 300 g L-1 + chitosan 0,6%, [5] citric acid 600 g L-1, [6] citric acid 600 g L-1 + chitosan 0,3%, [7] citric acid 600 g L-1 + chitosan 0,6%. Chitosan of low molecular weight and deacetylation degree of 75,58% (Sigma - Aldrich®) were used. After immersion, fruits were put to drain the excess of solution. Then, they were stored in cool chamber at 5ºC, previously sanitized, for 20 days. The experiment was conducted following a completely randomized design, with a factorial scheme composed by seven coating solutions and five sampling dates. Every five days were evaluated: loss of fresh mass of fruits; color; content of anthocyanins and the activity of peel enzymes polyphenoloxidase and peroxidase. It was verified that the solution of citric acid 600 g L-1, associated or not to chitosan, and the combination of chitosan 0,3% to 300 g L-1 of citric acid were the most efficient to maintain the quality of litchi 'Bengal' for 20 days at 5ºC.

Behavior of the brown-rot fungus Gloeophyllum trabeum on thermally-modified Eucalyptus grandis wood

In this study, we aimed evaluate the behavior of the brown-rot fungus Gloeophylum trabeum and white-rot fungus Pycnoporus sanguineus on thermally-modified Eucalyptus grandis wood. To this end, boards from five-year-eleven-month-old E. grandis trees, taken from the Duratex-SA company stock, were thermally-modified between 180 ºC and 220 ºC in the Laboratory of Wood Drying and Preservation at Universidade Estadual Paulista - UNESP, Botucatu, Sao Paulo state Brazil. Samples of each treatment were tested according to the ASTM D-2017 (2008) technical norm. The accelerated decay caused by the brown-rot fungus G. trabeum was compared with the decay caused by the white-rot fungus P. sanguineus, studied by Calonego et al. (2010). The results showed that (1) brown-rot fungus caused greater decay than white-rot fungus; and (2) the increase in temperature from 180 to 220 ºC caused reductions between 28.2% and 70.0% in the weight loss of E. grandis samples incubated with G. trabeum.

Biodegradação de filmes de polietileno de baixa densidade (PEBD), polihidroxibutirato-co-hidroxivalerato (PHBV) e blenda de PEBD/PHBV (70/30), em coluna de solo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Preparação de soluções sólidas superficiais à base de alumina como catalisadores para síntese do biodiesel via rota etílica

Pós-graduação em Química - IBILCE

Avaliação de propriedades físico-químicas, mecânicas e antimicrobianos do MTA e cimento Portland associado a solução de nanopartículas de prata

Pós-graduação em Odontologia - FOAR

Conservação pós-colheita de mangaba (Hancornia Speciosa Gomes)

Pós-graduação em Agronomia - FEIS

Avaliação do potencial pozolânico da cinza de lodo de águas residuárias por meio de técnicas instrumentais

Pós-graduação em Engenharia Civil - FEIS

Preparação e caracterização do compósito poli (fluoreto de vinilideno) / polianilina com partículas de níquel

Pós-graduação em Ciência dos Materiais - FEIS

Estudo in vitro do comportamento de facetas confeccionadas com artglass e targis quando submetidas à inserção e remoção de grampos circunferenciais em cromo-cobalto

Aiming to investigate in vitro the behavior of esthetic veneers placed in crows and made of the laboratory resins Artglass and Targis when submitted to insertion and removal of circunferential cobalt-chromium clasps, 24 veneer crowns were made (twelve with Artglass (Heraeus Kulzer) and twelve with Targis (Ivoclar Vivadent)), as well as the respective cobalt-chromium clasps. The crowns were then submitted to five thousand cycles of clasps insertion and removal, using a proper device. Using the verification of the force necessary to remove the clasps over the crowns during the experiment, the clasps and crowns mass variation, and the macroscopic inspection of the veneers, one may conclude that the veneers did not show a significant variation of the force required to remove the clasps over the crowns; they show a little amount of abrasion, possible to detect using a visual inspection and they show a little and variable amount of mass loss, less for that made with Artglass (average of 0,002g) and greater for that made with Targis (average of 0,006g)

Conservação pós-colheita de melões inteiros e minimamente processados

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Influência ao consumo crônico de álcool no fêmur de ratos machos e fêmeas

Considering that alcohol has been identified, in the literature, as an evident risk factor for osteoporosis development, inducing loss of bone mass, the aim of this study was to evaluate the effect of the alcohol on the femur of male and female rats. For this purpose, 35 male and 35 female rats, divided into seven groups of five animals per genera were included. The groups were: control group that received food and water as much as they wished; alcohol group in the concentrations of 10, 20 and 30% and the isocalorie: groups corresponding to the concentration of alcohol. After 8 weeks, the animals were sacrificed and evaluated regarding to the body weight and nutritional conditions. Unilateral femurs were removed and analyzed in relation to the length, width, and thickness of the bone cortical, trabeculae percentage and optical density. Data obtained were analyzed by ANOVA (Tukey; p<0.05). Regarding to the weight, loss of weight was observed in the animals of the group alcohol 20% among females and 30% among the males. In relation to the nutritional conditions, the females with the dosages of 10, 20 and 30% of alcohol swallowed a mean of 25, 39 and 53% of Kcall and the males 22, 36 and 45 Kcal Jday coming from the alcohol. Alcohol reduced the length of the femur only in the group MG6. Mesio-distal width was higher in the group FG6 although the antero-posterior width was not modified. The cortical thickness among males and females was not altered however the percentage of trabeculae bone was reduced among females alcohol 30% and among males with the three alcoholic concentrations. Optical density was reduced in the concentration of 30% among the males and females. Under the experimental conditions, it could be concluded that the effect of alcohol was more evident among the males and in the trabeculae bone, and that the alcoholic concentration of 30% was the most harmful for the bone tissue, ....

Qualidade do abacate 'HASS' frigoarmazenado submetido a atmosferas modificadas ativas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)