Influence of biosolids rate on chemical properties of an oxisol in São Paulo, Brazil

Organic residues may cause major health and environmental problems. This is the case in our study area, where more than 10 billion L per year of residential and industrial waste are produced. Land application of biosolids can be an economical solution by recycling waste and can provide valuable fertilizer if used correctly. The aim of this work was to study the effect of biosolids on the chemical properties of an Oxisol. The experiment was located at Ilha Solteira northwest of São Paulo State, Brazil. The soil was cropped to Sorghum bicolor.The field experimental design consisted of random blocks with six treatments and four replications of each treatment. Biosolids were surface applied to four treatments at rates of 5, 10, 20, and 40 Mg ha(-1) on a dry matter basis; in addition, a treatment with mineral fertilizer and a control were included. One year after biosolids application, soil samples were taken at 0-10, 10-20, and 20-40 cm. Organic matter content (Walkley-Black) and pH (CaCl2) were routinely determined. Cation exchange capacity, exchangeable bases (Ca, Mg, K), and P were determined by exchange resin extraction. No significant differences in any of the analyzed properties were found below the 20 cm depth. Extractable phosphorus (P) and potassium (K) increased with increasing biosolids rate in the top 20 cm, whereas calcium (Ca) and (Ma) magnesium content were not significantly influenced by biosolids. Soil pH decreased with increasing biosolids application. The sewage sludge application did not influence the sorghum production in the first year of culture, under unfavorable soil moisture conditions, but it influenced the dry matter.

The influence of cyclosporin a on mechanical retention of dental implants previously integrated to the bone: A study in rabbits

Background: Immunosuppressive agents may induce severe changes on bone metabolism and may impair the osseointegration process during the implant healing. No data are available concerning the influence of cyclosporin A on dental implants previously integrated to the bone. The aim of this study was to evaluate the influence of cyclosporin A administration on the mechanical retention of bone previously integrated to dental implants.Methods: Eighteen female New Zealand rabbits were submitted to an implant surgery. Each animal received one commercial dental implant of 10 x 3.75 mm. After 12 weeks of an undisturbed healing period, six animals were randomly sacrificed and the removal torque test was performed (group A). In addition, six animals were submitted to a daily injection of cyclosporin A in a dosage of 10 mg/kg (group C), and six animals received saline solution as a control (group B). After 12 weeks of cyclosporin A administration, groups B and C were sacrificed and submitted to a removal torque test in which higher values can be interpreted as higher mechanical bone retention to the implant surface or higher osseointegration.Results: the removal torque results were 30.5 (+/- 9.8) Ncm for group A, 50.17 (+/- 17.5) Ncm for group B, and 26 (+/- 7.8) Ncm for group C. The statistical analysis showed significant differences between groups A and B (P < 0.05) and groups B and C (P < 0.01).Conclusion: Cyclosporin A administration may impair the mechanical retention of dental implants previously integrated to the bone.

Influence of drying conditions on ascorbic acid during convective drying of whole persimmons

Degradation kinetics of food constituents may be related to the matrix molecular mobility by glass transition temperature. Our objective was to test this approach to describe ascorbic acid degradation during drying of persimmons in an automatically controlled tray dryer with temperatures (40 to 70 degrees C) and air velocities (0.8 to 2.0 m/s) varying according a second order central composite design. The Williams-Landel-Ferry model was satisfactorily adjusted to degradation curves for both control strategies adopted-constant air temperature and temperature fixed inside the fruit. Degradation rates were higher at higher drying temperatures, independent of the necessary time to attain the desired moisture content.

Influence of silver additions on the Cu-13 wt pct Al alloy hardness.

The influence of silver additions on the Cu-13 wt. pot. Al alloy hardness was studied for additions in the range 0 to 16 wt. pot Ag. The results indicated a pronounced hardness increase with the silver content and an influence of the quenching temperature. Data obtained from scanning electron microscopy indicated that the formation of silver-rich precipitates, wich change with the quenching temperature, seems to produce the changes on alloys hardness.

Influence of silver additions on the thermal behavior of the Cu-8 mass% Al alloy

The influence of additions of 2, 4, 6, 8, 10 and 12 mass% Ag on the thermal behavior of the Cu-8 mass% Al alloy was studied using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffractometry (XRD). The results indicate that the presence of silver introduces new thermal events, due to the formation of a silver-rich phase and, for additions of 10 and 12 mass% Ag, it is possible to verify the formation of the gamma (1) phase (Cu9Al4) and the metastable transitions which are only observed in alloys with a minimum of 9 mass% Al.

Influence of drying conditions on the rheological properties of prunes

Rheological properties of rehydrated prunes were obtained applying compression-relaxation tests by using a Texture Analyzer TAXT2i. A mathematical development was adopted to determine the stress and area, along the deformation. Experimental data of stress versus time was fitted by using three different rheological models: generalized Maxwell, Normand & Peleg and Maxwell. Results showed that generalized Maxwell model can be used to describe the viscoelastic behavior of the samples. The rheological parameters obtained indicated that prunes exhibited elastic behavior more pronounced at low moisture content and drying air temperature. At high moisture content and temperature the sample became a more viscous and less rigid.

Influence of ionic interactions on the photoinduced Birefringence of poly[1-[4-(3-carboxy-4 hydroxyphenylazo) benzene sulfonamido]-1 2-ethanediyl, sodium salt] films

Electrostatic interactions govern most properties of polyelectrolyte films, as in the photoinduced bire-fringence of azo-containing polymers. In this paper we report a systematic investigation of optical storage characteristics of cast and layer-by-layer (LbL) films of poly[1 -[4-(3-carboxy-4 hydroxypheny-lazo) benzene sulfonamido]-1,2-ethanediyl, sodium salt] (PAZO). Birefringence was photoinduced faster in PAZO cast films prepared at high pHs, with the characteristic writing times decreasing almost linearly with the pH in the range between 4 and 9. This was attributed to an increased free volume for the azochromophores with the enhanced electrostatic repulsion in PAZO charged to a greater extent. In contrast, in LbL films of PAZO alternated with poly(allylamine hydrochloride) (PAH), the electrostatic interactions between the oppositely charged polymers hampered photoisomerization and molecular rearrangement, thus leading to a slower writing kinetics for highly charged PAH or PAZO.

Influence of moisture absorption on mechanical behaviour of composites

Because of their application that normally demands high mechanical strength combined with low weight, the fibre/matrix interface became an important parameter concerning structural life. The problem of moisture absorption in materials has received attention in experimental studies on a composite systems as well as from a theorical point of view. The fibre/matrix interface plays an important role in the structural behaviour of composites due to the fact that load transfer from matrix to reinforce occurs at the interface. In this case the study of compatibility of fibre/matrix/environmental is essential to ensure a product that attend structural objectives, many times without failure possibilities. The composite used in this investigation is the carbon fibre/matrix epoxy composite, which was immersed in sea water standard during 94 days at 60 degrees C, submitted to tensile and compressive tests to study the influence of moisture absorption on mechanical behaviour. The interface was investigated through fracture surface analysis by SEM and a strong interface and a good adhesion fibre/matrix was observed.

Influence of organic fertilisation on leaves and essential oil production of Ocimum gratissimuim L.

The experiment was installed in Lageado Experimental Farm with aim to verify the influence of organic fertilisation (0, 4, 8 and 12 kg of manure/m(2) - with four replications) on leaves and essential oil production of Ocimum gratissimum. The harvesting was done twice (May - autumn and August - winter), and the leaves were separated for extraction of essential oil by Clevenger apparatus. The leaf production and oil content were calculated on dry mass basis. The results showed no statistical difference for organic fertilisation, although significant difference was verified for seasons. The main constituents of essential oil were eugenol and 1,8- cineole. The amount of the eugenol was higher in autumn, while the presence of other components including 1,8-cineole, beta-selinene and trans-caryophyllene were more dominant at wintertime.