Contrasting continuous emission versus freeze-out via HDT

The effect of continuous emission hypothesis on the two-pion Bose-Einstein correlation is discussed and compared with the corresponding results based on the usual freeze-out ansatz. Sizable differences in the correlation function are observed when comparing these two scenarios of the decoupling process. They could lead to entirely different interpretation of properties of the hot matter formed in high-energy heavy-ion collisions.

A note on the attenuation of the sommerfeld effect of a non-ideal system taking into account a MR damper and the complete model of a DC motor

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The effect of hydrothermal alteration on the Sr and Nd isotopic signatures of the Barra do Itapirapua Carbonatite, Southern Brazil

The Cretaceous Barra do Itapirapua carbonatite in southern Brazil experienced extensive postmagmatic hydrothermal alteration. In this article, Sr and Nd isotope ratios of coexisting samples of hydrothermally overprinted and of preserved, nonoverprinted carbonatite are presented. Hydrothermal alteration caused strong REE enrichment, leading to the formation of minerals of the bastnaesite group. In the overprinted carbonatite, Nd contents reach 4000 ppm, two orders of magnitude higher than in the fresh carbonatite, but epsilon(Nd) varies only within a range of 3.4 units. In contrast, Sr was leached from the carbonatite during the postmagmatic alteration; hence values of around 10,000 ppm in the fresh carbonatite drop to about 1000 ppm in the overprinted samples. Leaching is accompanied by a variation of Sr isotopic composition toward more radiogenic values, resulting in an increase of 15 units in epsilon(Sr). Variation of Sr isotopic composition is related to postmagmatic alteration and is decoupled from the variation of Nd isotopic composition, ruling out heterogeneities in the mantle source as the main cause of isotopic variability in the data set. Furthermore, this cannot be explained by bulk crustal contamination. A two-step model is proposed in which (1) a REE-rich, carbonatite-derived hydrothermal fluid overprinted the pristine carbonatite, causing REE-enrichment with a relative small change of isotopic composition; and (2) crust-derived hydrothermal fluids percolated the cooling carbonatite, leaching the original Sr from the carbonatite and introducing a more radiogenic Sr isotopic signature. The amounts of carbonatite-derived Nd with primitive, carbonatite-like Nd isotope ratios introduced during the first stage of hydrothermal alteration are high enough to buffer the effect of crust-derived Nd on the Nd isotopic composition of the overprinted carbonatite.

Effect of the addition of invert sugar on the production of cephalosporin C in a fed-batch bioreactor

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

Effect of precursor solution on the formation of perovskite phase of Pb(Mg-1/Nb-3(2/3))O-3 thin films

Precursor solutions for Pb(Mg1/3Nb2/3)O-3 (PMN) synthesis were obtained by Pechini's method. The influence of the concentration of organic materials on the phase formation has been studied. For this purpose, PMN solutions were prepared with different precursors and were characterized by thermogravimetric and differential thermal analysis. The obtained solutions were deposited onto a Si (100) substrate by dip coating and pre-treated in a hot plate at 300 degreesC for 1 h. The films were annealed at 600, 700, 800 and 900 degreesC for 1 h and characterized by X-ray diffraction. The perovskite phase was formed after annealing at 600 and 700 degreesC when the solution of PMN was prepared with a lower amount of organic material and starting with mobium oxide. By increasing the temperature to 800 or 900 degreesC, only the formation of pyrochlore phase was observed. With the solution prepared from mobium ethoxide, only the presence of pyrochlore phase was observed independently of the annealing temperature. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Effect of Ag addition on the martensitic phase of the Cu-10 wt.% Al alloy

Thermal analysis and compression tests at room temperature have been carried out for Cu-10 wt.% Al and Cu-10 wt.% Al-10 wt.% Ag alloys samples. The results indicate that the decomposition reaction of the (beta(1)) parent phase is decreased suppressed and a martensite stabilization effect can be induced by Ag addition. The Cu-Al-Ag alloy shows some degree of shape memory capacity. (C) 2007 Elsevier B.V. All rights reserved.

Effect of dietary organic selenium and zinc on the internal egg quality of quail eggs for different periods and under different temperatures

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

Effect of cyproterone acetate on alpha1-adrenoceptor subtypes in rat vas deferens

Gonadal hormones regulate the expression of alpha1-adrenoceptor subtypes in several tissues. The present study was carried out to determine whether or not cyproterone acetate, an anti-androgenic agent, regulates the alpha1-adrenoceptor subtypes that mediate contractions of the rat vas deferens in response to noradrenaline. The actions of subtype selective alpha1-antagonists were investigated in vas deferens from control and cyproterone acetate-treated rats (10 mg/day, sc, for 7 days). Prazosin (pA2 ~9.5), phentolamine (pA2 ~8.3) and yohimbine (pA2 ~6.7) presented competitive antagonism consistent with activation of alpha1-adrenoceptors in vas deferens from both control and treated rats. The pA2 values estimated for WB 4101 (~9.5), benoxathian (~9.7), 5-methylurapidil (~8.5), indoramin (~8.7) and BMY 7378 (~6.8) indicate that alpha1A-adrenoceptors are involved in the contractions of the vas deferens from control and cyproterone acetate-treated rats. Treatment of the vas deferens from control rats with the alpha1B/alpha1D-adrenoceptor alkylating agent chloroethylclonidine had no effect on noradrenaline contractions, supporting the involvement of the alpha1A-subtype. However, this agent partially inhibited the contractions of vas deferens from cyproterone acetate-treated rats, suggesting involvement of multiple receptor subtypes. To further investigate this, the actions of WB 4101 and chloroethylclonidine were reevaluated in the vas deferens from rats treated with cyproterone acetate for 14 days. In these organs WB 4101 presented complex antagonism characterized by a Schild plot with a slope different from unity (0.65 ± 0.05). After treatment with chloroethylclonidine, the complex antagonism presented by WB 4101 was converted into classical competitive antagonism, consistent with participation of alpha1A-adrenoceptors as well as alpha1B-adrenoceptors. These results suggest that cyproterone acetate induces plasticity in the alpha1-adrenoceptor subtypes involved in the contractions of the vas deferens.

Effect of high and low molecular weight glutenin subunits, and subunits of gliadin on physicochemical parameters of different wheat genotypes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of flooding on survival and initial growth of Ocotea pulchella (Nees) Mez. seedlings in semi-controlled light conditions

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

Ovarian development in Meliponine bees (Hymenoptera: Apidae): the effect of queen presence and food on worker ovary development and egg production

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

Effect of broiler breeder age on pancreas enzymes activity and digestive tract weight of embryos and chicks

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

Knoop hardness of dental resin cements: Effect of veneering material and light curing methods

This study evaluated the Knoop hardness of one resin cement (dual-cure mode or light-cure mode) when illuminated directly or through restorative materials-ceramic (HeraCeram) or composite (Artglass)-by two light curing units. Light curing was carried out using a conventional quartz tungsten halogen (QTH) light source (XL2500) for 40 s, and a light emitting diodes (LED) light source (Ultrablue Is) for 40 s. Bovine incisors had their buccal faces flattened and hybridised. on these surfaces, a mould was seated and filled with cement. A disc of the veneering material (1.5 mm thickness) was positioned over this set for light curing. After storage (24 h/37 degrees C), samples (n = 10) were sectioned for hardness (KHN) measurements. Data were submitted to ANOVA and to Tukey's test (alpha = 0.05). In general, light curing with LED resulted in higher hardness values than QTH. Distinct cement behaviour was observed with different veneering material in association with different light curing units (LCUs). (C) 2006 Elsevier Ltd. All rights reserved.

Effect of the composite surface sealant application moment on marginal sealing of compactable composite resin restoration

An analysis was carried out to observe whether the application or not of a composite surface sealant (CSS), as well the moment for CSS application were able to reduce marginal microleakage in compactable composite resin restoration. All the preparations were restored with a compactable composite resin. The restored teeth were randomly assessed. G1 (control group): finished and polished; G2: finished, polished, etched and cover with CSS; G3: immediately after the restoration done the CSS was applied, then finished and polished; G4: CSS applied immediately after the restoration was done, the finished and polished, etched, and covered with CSS. The specimens were isolated with nail polish, thermocycled, immersed in aqueous solution of silver nitrate, and followed in a photo developing solution. The microleakage scores obtained from the occlusal and cervical walls were analyzed with the Kruskall-Wallis nonparametric test. No microleakage was found at the enamel margins. Comparing the microleakage scores at dentin/cementum margins (p < 0.05) it was found that G3 (p = 0.0162) and G4 (p = 0.0187) were able to reduce microleakage when compared with group G2. However the results were not statistically different from the control group. The application of CSS was not able to completely eliminate marginal microleakage at the dentin/cementum margins.

Effect of aging on the stability of ceramic foams prepared by thermostimulated sol-gel process

This work presents a new route of preparation of zirconium ceramic foams based on the thermostimulated sol-gel process. This method produces gelled bodies with up to 90% of porosity in the wet gel and can be used to make complex-shaped components. Unfortunately, the shrinkage during the drying step allows to a catastrophic reduction (50%) of the foam porosity. To improve the foam stability we carried out a systematic study of the effect of gel foam aging on the drying process. Samples were aged in closed vessel at 25 C during different time period (from 6 to 240 h). The shrinkage and the mass loss during drying at 50 C were measured in situ, using a non-contact technique performed with a special apparatus. The results show that the total linear shrinkage decreases from 46% to 8% as the aging period increase from 6 to 240 h. This behavior is followed by a small change of total mass loss, from 42 to 54%. It indicates that by aging the structural stiffness of the foams increases due to secondary condensation reactions. Thus, by controlling the aging period, the porosity can be increased from 67 to 75% and the average size of mesopores of dried foams can be screened from 0.3 to 0.9 mum. Finally, these results demonstrate that the thermostimulated sol-gel transition provides a potential route to ceramic foams manufacture.