Comportamento contrátil de barreiras selantes de solo estabilizado para base de lagoas de tratamento

Liners were proposed as subsoil contamination protection devices for waste disposal sites. In the rural environment, they can be used to construct pond bottoms for liquid waste treatment, but the construction needs to be quick and cheap. A good technical solution for these situations is the use of local soil compacted with low quantities of cement or lime, obtaining good properties for this purpose. These barriers need special care about their contraction behavior which may compromise its use. This work shows the results of contraction tests in sandy soil specimens and others stabilized with lime and with cement. Soil structure changes during cure time were checked using electronic scan microscopy. Results show maximum soil contraction of 0.648% for specimen with 14 days cure process. After twenty eight days of cure the contraction values were lower than 0.5%, which classifies the material as of low contraction. Electronic scan image shows significant material structure alteration up to seven days cure. Results show that studied mixtures had appropriate contraction behavior for liner usage.

Biocompatibility of resin-based dental materials applied as liners in deep cavities prepared in human teeth

Background: Since only a few data have been published concerning the effects of resinous dental materials on the pulp-dentin complex, the aim of this study was to evaluate the biocompatibility of resin-based materials applied as liners in deep cavities prepared in duman teeth. Methods: After preparing class V cavities, the following dental materials were applied on the axial walls: group 1, Vitrebond™ (VIT; 3M ESPE); group 2, Ultra-Blend® Plus™ (UBP; Untradent); and group 3, Clearfil™ SE Bond (CSEB; Kuraray). In group 4 (control), the hard-setting calcium hydroxide cement Dycal (CH; Caulk/Dentsply) was used. The teeth extracted at 7 days or between 30 and 85 days after the clinical procedures were processed for histological evaluation. Results: For all the experimental and control groups, most of specimens exhibited no pulpal response or slight inflammatory reaction associated with slight tissue disorganization at 7-day period. Moderate inflammatory pulpal response occurred only in one tooth (RDT = 262 μm) of group 3 in which transdentinal diffusion of resin components was observed. Conclusion: The resin-based dental cements VIT and UBP as well as the bonding agent CSEB presented acceptable biocompatibility when applied in deep cavities prepared in sound human teeth. © 2006 Wiley Periodicals, Inc.

Plant nutrients in a degraded soil treated with water treatment sludge and cultivated with grasses and leguminous plants

The objective of this work was to evaluate rates for applications of water treatment sludge (WTS) as a nutrient source for grasses and leguminous plants cropped in a soil degraded by tin mining in the Amazon Region (Natural Forest of Jamari, Rondonia State, Brazil). The treatments consisted of three rates of nitrogen supplied by WTS (100, 150 and 200 mg kg -1 soil), five combinations of plants, two controls (absolute control, without fertilization; and chemical control, soil+lime+chemical fertilizers). WTS modified the contents of macro and micronutrients in the degraded soil, but it was not, as used in the present study, sufficient for the rehabilitation of the degraded area. © 2006 Elsevier Ltd. All rights reserved.

Defect-induced photoluminescence of powdered silica glass

Visible photoluminescence was generated in standard soda-lime-silica glass powder, mechanically milled in a high-energy attrition mill. The broad emission band maximum shows a linear dependence on the exciting wavelength, suggesting the possibility to tune the PL emission. The photoluminescence was attributed to defect generation related to unsatisfied chemical bonds due to the high surface area. Raman scattering and ultraviolet-visible optical reflectance measurements corroborate this assertion. Transmission electron microscopy measurements indicate that the powder is composed by nanocrystallites with about 10-20 nanometers immersed in an amorphous media.

Efeito residual de calcário, nitrogênio e zinco na produção de matéria seca de Brachiaria decumbens em condições de campo

The balance of liming and fertilization practice with nitrogen and zinc could affect the production of the pasture. Thus, the present work has as objective to evaluate the residual effect of the application of calcareous rock, nitrogen, and zinc on the dry matter production of Brachiaria decumbens, during three cuts. For this, an experiment was installed in Selvíria, Brazil, on a distrofic red Latosol, from october 1997 to may 1998. The experimental design was randomized blocks, in a factorial project 3×3×2, with four repetitions. The treatments were three doses of nitrogen: 0, 50, and 100 kg/ha, three doses of lime: 0, 267, and 556 kg/ha, corresponding to 41, 50, and 60% of the levels of base saturation, respectively, and two doses of zinc 0 and 5 kg/ha, applied in the first year and reapplied in the second year, except for the limestone. Four cuts were done in the grass at 10 cm of height, with intervals of 49 days, to obtain the dry matter production. The limestone application in the first year did not provide to residual effect on the production of Brachiaria decumbens. However, the nitrogen fertilization increased the dry matter production of the grass. The application of zinc in the first year and the reapplication in the second year did not result in a productive response of B. decumbens. © 2009 Instituto Nacional de Investigaciones Agricolas INIA.

In vitro evaluation of the effect of natural orange juices on dentin morphology

The patient's diet has been considered an important etiological factor of dentin hypersensitivity. The frequent ingestion of acidic substances can promote the loss of dental structure or remove the smear layer. The purpose of this study was to evaluate the degree of smear layer removal and dentinal tubules exposure by different natural orange juices. Extracted human teeth were submitted to manual scaling in order to develop the smear layer. Seventy dentin samples were obtained and distributed into the following groups: Control, lime orange, lime, valência orange, navel orange, mandarin, and tangerine. Each group included 2 methods of application: Topical and topical + friction. After preparation for SEM analysis, photomicrographs were assessed by a blind calibrated examiner using an index system. The Kruskal-Wallis test indicated a significant influence of the orange juices on smear layer removal. Significant difference was observed between navel orange, valência orange, mandarin and the control group (p < 0.05). These orange juices resulted in greater removal of the smear layer and greater opening of dentinal tubules. The comparison between the application methods for each group using the Mann-Whitney test showed that friction increased smear layer removal significantly only for lime orange and lime. The data suggest that certain natural orange juices are more effective in terms of smear layer removal and dentinal tubules exposure than others.

Resposta do manjericão (Ocimum basilicum L.) cultivado em solos corrigidos com calcário e escória silicatada: Caracterí sticas agronômicas e produção de matéria seca

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alternative to peat for Agaricus brasiliensis yield

Casing layer is one of the most important components of Agaricus spp. production and it directly affects mushroom productivity, size and mass. The aim of this study was to evaluate potential raw materials as a casing layer and their effect on Agaricus brasiliensis productivity. Raw materials from Brazil with potential use were selected and characterized, and the most promising ones were tested as casing layers for mushroom yield. Evaluated raw materials included lime schist, vermiculite, eucalyptus sawdust, sand, São Paulo peat, Santa Catarina peat, subsoil and charcoal. Particle size, porosity and water absorption in relation to mushroom yield for casing layers were determined. Lime schist, an alternate casing layer to peat, is presented and the effects of the casing layer on the mushroom yield are discussed. © 2009 Elsevier Ltd. All rights reserved.

La transformation productive 20 ans aprés: problémes anciens, nouvelles opportunités. Synthése

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Atributos químicos do solo e produtividade da cultura de soja em área de semeadura direta após calagem superficial

This study was carried out to evaluate the effects of surface application of lime rates on soil chemical attributes and soybean yield in a no-tillage system. It was installed a field experiment in a factorial 2×4, and the factors were: two types of lime (calcitic and dolomitic); four rates (0.0 - 0.5 - 1.0 and 1.5 t ha-1 of CaCO3), in a completely randomized blocks experimental design, with four replications. The experiment was located in Matupá, Mato Grosso State, Brazil, being the work developed between November 2006 and May 2007. The evaluations were chemical attributes in the soil layers (0,0-2,5 cm, 2,5-5,0 cm and 5,0-10,0 cm), and the productive characteristics of soybean. Application of lime increased the soil pH (CaCl 2), the exchangeable Ca and Mg, the effective CEC and the base saturation only in the soil surface layer. The two limes were different only for Ca and Mg values in the first layer of soil, and only for the Mg values in the layer of 2,5-5,0 cm. The surface liming in no-tillage system did not change soybean yield.

Régime de croissance, vulnérabilité financière et protection sociale en Amérique latine. Les conditions "macro" de l'efficacité de la lutte contre la pauvreté

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Estabilização de sistemas fuzzy T-S incertos usando realimenta̧ão derivativa

In some practical problems, for instance, in the suppression of vibration in mechanical systems, the state-derivative signals are easier to obtain than the state signals. Thus, a method for state-derivative feedback design applied to uncertain nonlinear systems is proposed in this work. The nonlinear systems are represented by Takagi-Sugeno fuzzy models during the modeling of the problem, allowing to use Linear Matrix Inequalities (LMIs) in the controller design. This type of modeling ease the control design, because, LMIs are easily solved using convex programming technicals. The control design aimed at system stabilisation, with or without bounds on decay rate. The efficiency of design procedure is illustrated through a numerical example.

Esterco bovino para o desenvolvimento inicial de plantas provenientes de quatro matrizes de Corymbia citriodora

This work aimed to evaluate the effect of cattle manure levels in the phase of implementation Corymbia citriodora (Hook.) K. D. Hill & L. A. S. Johnson (Eucalyptus citriodora) seedlings in field, produced from seeds collected from four mother trees. The experiment was carried out in green house, in pots filled with 5 dm 3 of Oxisol. Five cattle manure levels were applied 0, 10, 20, 30, and 40 t ha -1 (0, 25, 50, 75, and 100 g pot -1). All treatments received lime levels which were calculated to increase the base saturation degree to 50%. The soil fertility was evaluated after 30 days of soil incubation with manure and lime. The seeds were collected from mother trees called 2, 8, 20 and 29. Sowing was performed directly in rigid plastic containers of 50 cm 3 and seedlings were transplanted when they were around 17 cm height. The experimental design was entirely randomized, in a factorial 5 × 4 (five doses of cattle manure and seeds of four mother trees) scheme and four repetitions. Each parcel was a pot with two plants. At 90 days the height, foliar area, stalk diameter, shoot and root dry matter. The plants responded positively to application of manure, but differently for each evaluated growth characteristic linearly or quadratically. The manure levels had linear effects on growth characteristics and dry matter production of the plants from mother trees 2 and 20 moreover these plants require more cattle manure levels than ones from mother trees 8 and 29. The cattle manure promoted the best development of plants from mother trees 8 and 29, in relationship with dry matter production of shoot components was approximately 27 t ha-1, equivalent to 67.5 g pot.

Nitrogênio, fósforo e potássio na produção de massa seca e no acúmulo de nutrientes em mudas de limeira ácida 'tahiti'

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desempenho de novilhas de corte alimentadas com cana hidrolisada

The objective of this study was to evaluate the performance, consumption and feed conversion of Angus x Nellore heifers fed hydrolyzed sugarcane. Twenty-four (1/2 Angus x Nellore crossbred) heifers were used with average body weight of 242 kg ± 23 kg, confined in individual pens with total area of 15 m2. The study consisted of six treatments distributed as follows: T1-in natura sugarcane: sugarcane was given to animals after being chopped; T2-hydrolyzed sugarcane with 0.5 % lime and 24 hours of air exposure; T3-hydrolyzed sugarcane with 0.5 % lime and 48 hours of air exposure; T4-hydrolyzed sugarcane with 1.0 % lime and 24 hours of air exposure; T5-hydrolyzed sugarcane with 1.0 % lime and 48 hours of air exposure; T6-hydrolyzed sugarcane with 1.0 % lime and 72 hours of air exposure. We used a completely randomized design with four replicates per treatment, and averages were compared by Tukey test at 5 % significant level of probability. No statistical difference was found for any of the treatments (P>0.05). The processing of sugarcane with lime did not increase the intake and performance of animals evaluated in this study.