Application of standard and modified Judd-Ofelt theories to thulium doped fluoroindate glass

Fluoroindate glasses of the following compositions: (40-x)InF3-20ZnF(2)-16BaF(2)-20SrF(2)-2GdF(3)-2NaF-xTmF(3) with x = 1,3 mol% were prepared in a dry box under an argon atmosphere. The absorption spectra at room temperature in the spectral range 350-2200 nm were obtained. The spectra obtained for each sample had similar absorption and only the amplitude of the different bands changed as the concentration of Tm3+. The experimental oscillator strengths were determined from the areas under the absorption bands. Using the standard and modified Judd-Ofelt theory, intensity parameters Ohm(lambda) (lambda = 2,4,6) and (lambda = 2,3,4,5,6), respectively for f-f transitions of Tm3+ ions as well as transition probabilities, branching ratios and radiative lifetimes for each band were determined. The results are compared with those of other glasses described in the literature. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Vascular organization of the hystricomorph placenta: a comparative study in the Agouti, capybara, guinea pig, paca and rock cavy

The placental vasculature of five hystricomorph rodents was examined by latex injection of the blood vessels, immunohistochemistry and scanning electron microscopy of vessel casts. The pattern of branching of the vessels is described at the level of fine structure. The placenta is divided into lobes separated by interlobular trophoblast. Fetal arteries course through the interlobular areas and give rise to capillaries from which blood drains into veins at the centre of the lobes. Maternal blood reaches the placenta through spiral arteries that pass around the perimeter of the subplacenta. They supply large maternal blood sinuses, lined by trophoblast, which run through the interlobular areas and into the centre of the lobes. Here they supply fine channels that run parallel to the fetal capillaries, so that maternal blood flows from the centre of the lobe to the periphery. This arrangement provides the morphological basis for countercurrent exchange. The maternal channels of the labyrinth drain into spaces formed by the latticework of the interlobular trophoblast and thence through venous lacunae to a basal venous lacunar ring. The subplacenta is supplied by a single fetal artery. The vessels within the subplacenta pursue a tortuous course with dilatations and constrictions as in an endocrine gland. (C) 2003 Elsevier Ltd. All rights reserved.

Audouinella macrospora (Acrochaetiaceae, Rhodophyta) is the Chantransia stage of Batrachospermum (Batrachospermaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Produção de polpas de mangas Tommy Atkins, na Amazônia setentrional, através da aplicação de preservativos e da pasteurização

The present work had evaluated the efficiency of the pasteurization and the use of preservatives in mangos pulps (Mangifera indica L.) refrigerated. Before carrying out the treatments, the fruits had been cleaned in solution of sodium hypochlorite (NaOCl) at 100 mg. L(-1), for 10 minutes. After the processing, it was carried out through the adjustment of pH of pulps for 3.0 and the adjustment of the water activity (W(a)) at 0.95. The used variable had been the branching (hot water at 95 +/- 5 degrees C, for 0 and I minute), the addition of sodium benzoate in the concentrations of 0; 200 and 500 mL.L(-1) and, sulfite dioxide (SO(2)) in 0, 100 and 200 mL.L(-1). Then the pulps had been packed in low density polyethylene (LDPE) bags of 0,060 mm (0.10 x 0.12 m - without free space and content of 500g of pulp) and, conditioned in at 20 +/- 1 degrees C e 80 +/- 3% of R.H, for 28 days. At the end of the experiment, the treatments not submitted to the branching had shown the biggest ascorbic acid levels. However, in these same treatments had been noticed intense microbiological activity and raised levels of pH. There aren't significant differences between the tested treatments in the titratable acidity (TA) and soluble solids (SS) analyses. Due to the absence of black spot in the pulps used during all the experimental period, it couldn't be detected the differences between the application of the SO(2) and the use of the branching. The lower index of microbiological contamination and the preference of the judges in the sensorial panel had been attributed to the submitted treatments to the branching, addition of 500mL.L(-1) of sodium benzoate and addition of 200mL.L(-1) of sulfite dioxide.

Linear low density polyethylene (LLDPE) from ethylene using Tp(Ms)NiCl (Tp(Ms) = hydridotris(3-mesitylpyrazol-1-yl)) and CP2ZrCl2 as a tandem catalyst system

Linear low density polyethylene (LLDPE) with different branching contents were prepared from ethylene, without the addition of alpha-olefin comonomer, using a combination of catalyst precursors {Tp(Ms)}NiCl (1) (Tp(Ms) = hydridotris(3-mesitylpyrazol-1-yl)) and Cp2ZrCl2 (2) activated with MAO/TMA (1:1) in toluene at 0degreesC and by varying the nickel loading mole fraction (x(Ni)). The polymerization results showed that the turnover frequencies are strongly dependent on the x(Ni) varying from 6.6 x 10(3) to 32.1 x 10(3) mol[C2H4]/mol[Zr] h. The C-13 NMR spectra of the copolymers showed that the branch contents of the polymers increase as the x(Ni) increase in the medium promoting the production of polymers with a wide range of melting point (T-m) (C) 2004 Elsevier B.V. All rights reserved.

Theoretical study on the reaction mechanism of VO2+ with propyne in gas phase

Possible molecular mechanisms of the gas-phase ion/molecule reaction of VO2+ in its lowest singlet and triplet states ((1)A(1)/(3)A '') with propyne have been investigated theoretically by density functional theory (DFT) methods. The geometries, energetic values, and bonding features of all stationary and intersystem crossing points involved in the five different reaction pathways (paths 1-5), in both high-spin (triplet) and low-spin (singlet) surfaces, are reported and analyzed. The oxidation reaction starts by a hydrogen transfer from propyne molecule to the vanadyl complex, followed by oxygen migration to the hydrocarbon moiety. A hydride transfer process to the vanadium atom opens four different reaction courses, paths 1-4, while path 5 arises from a hydrogen transfer process to the hydroxyl group. Five crossing points between high- and low-spin states are found: one of them takes place before the first branching point, while the others occur along path 1. Four different exit channels are found: elimination of hydrogen molecule to yield propynaldehyde and VO+ ((1)Sigma/(3)Sigma); formation of propynaldehyde and the moiety V-(OH2)(+); and two elimination processes of water molecule to yield cationic products, Prod-fc(+) and Prod-dc(+) where the vanadium atom adopts a four- and di-coordinate structure, respectively.

Sulfonation and anticoagulant activity of botryosphaeran from Botryosphaeria rhodina MAMB-05 grown on fructose

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

Optical spectroscopy and upconversion luminescence in Nd3+ doped Ga10Ge25S65 glass

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Probing neutralino properties in minimal supergravity with bilinear R-parity violation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Considerations sur la ramification de L'aorte abdominale du hamster (Mesocricetus Auratus)

The disposition of the abdominal aorta branching in Mesocricetus auratus is described, establishing variation groups with relation to the celiac, cranial mesenteric, renal, genital and caudal mesenteric arteries. Sixty animals (30 males and 30 females) of different ages and weights, were anesthetized with chloroform, injected with contrasting substance in the abdominal aorta (50 animals with Neoprene latex and 10 with a radioopaque mass), after which they were dissected with the help of a stereoscopic microscope. The animals with radioopaque masses were radiographed in comparison with the other animals. The results are expressed in relative percentage figures and compared with other mammalian arterial dispositions.

Fine structure of lamellated nerve endings in the gingiva of man and the Cebus apella monkey

Gingival mucosae of man and the adult Cebus apella monkey were fixed for 3 hr in modified Karnovsky fixative containing 2.5% glutaraldehyde, 2% formaldehyde in 0.1 M sodium phosphate buffer (pH=7.4). The specimens were postfixed in 1% osmium tetroxide in 0.1 M sodium phosphate buffer at 4°C for 2 hr, dehydrated in a graded alcohol series and embedded in Epon 812. Thick sections of 1-3 μm and ultrathin sections of 40-80 nm in thickness were cut with glass knives on an LKB ultramicrotome. The thick sections were stained with toluidine blue solution, and the grids were stained with uranyl acetate and lead citrate and examined under a Philips EM-301 electron microscope. Our observations permitted us to conclude that: both gingival mucosae, of man and the Cebus apella monkey, have lamellar nerve endings; these corpuscles are localized in the papillar space of the epithelium and do not contact closely with the basement membrane; the nerve endings are composed of an afferent fiber which subdivides several times and forms irregular flattened or discoidal expansions; the laminae of the lamellar cells are very thin near the terminal axon and are larger and irregular in shape at the peripheral portion of the corpuscle; the terminal axon shows abundant mitochondria, myelin figures, clear vesicles, and multivesicular bodies; between the axoplasm membrane and adjacent cytoplasmic lamina and between the lamellae, small desmosome type junctions are noted; and the cytoplasmic material of the lamellae cells is characterized by the presence of numerous microfilaments, microtubules, mitochondria, rough endoplasmic reticulum, and caveolae.

Optical transition probabilities and compositional dependence of Judd-Ofelt parameters of Er3+ ions in fluoroindate glass

Fluoroindate glasses containing 1, 2, 3, and 4 mol% ErF3 were prepared in a dry box under an argon atmosphere. Absorption spectra of these glasses at room temperature were obtained. The Judd-Ofelt parameters Ωλ (λ = 2, 4, 6) for f-f transitions of Er3+ ions as well as transition probabilities, branching ratios, radiative lifetimes, and peak cross-sections for stimulated emission of each band were determined. The concentration effect on the intensities is analyzed. The optical properties of the fluoroindate glasses doped with Er3+ ions are compared with those of other glasses described in the literature. © 1995.

Glueballs in peripheral heavy-ion collisions

We estimate the cross-section for glueball production in peripheral heavy-ion collisions through two-photon and double-Pomeron exchange, at energies that will be available at RHIC and LHC. Glueballs will be produced at large rates, opening the possibility to study decays with very small branching ratios. In particular, we discuss the possibility of observing the subprocess γγ(PP) → G → γγ.

Aspectos morfo-anatômicos de Paepalanthus hilairei koern. (Eriocaulaceae) da Serra do Cipó-MG

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Northwestern overthrusting and related lateral escape during the Brasiliano orogeny north of the Patos lineament, Borborema province, northeast Brazil

The Borborema province (BP) of northeastern Brazil, located between the São Luís and São Francisco cratons, represents a branching system of Precambrian orogens of the South American platform. It is composed of segments of Archean and Proterozoic crust that were deformed by the convergence of the West African and São Francisco-Congo cratons during assembly of the Brasiliano collage (650 to 500 Ma), a period of intense orogenic activity considered to be the strongest and most pervasive tectonic event that affected the Precambrian of the South American platform. The tectonic and kinematic history of the Brasiliano/Panafrican orogeny is fundamental for reconstructing South American and African Precambrian geology. The correlation between Neoproterozoic tectonic processes occurring in both continents should use structural elements, of regional or local character, with identical kinematic and metamorphic conditions manifested in both basement and supracrustal units. North of the Patos shear zone, subhorizontal Brasiliano thrusts (0.65 to 0.58 Ga) affected the basement and the supracrustal Seridó belt with such related regional D1/D2 structures as foliation, lineation, isoclinal folds, and related metamorphism. Overprinting the previous structures, regional folding with a vertical S3 foliation and an associated strike-slip shear zone were developed (0.58 to 0.52 Ga). The metamorphism is similar for all deformation phases, ranging from upper-greenschist to amphibolite facies with mineral assemblages including biolite and garnet throughout the Seridó fold belt. We propose, on the basis of deformational and kinematic reconstructions, that the structural evolution of the Seridó fold belt was characterized by transition from a syn-collisional to a strike-slip regime. The transition between regimes occurred, progressively or instantaneously, by the switching of the maximum and intermediary strain axes of the strain ellipsoid. The entire tectonic history can be related to a frontal or oblique collision and lateral escape tectonics, with local, syn-collisional transpression and transtension. The Patos shear zone represents a final vertical shearing, juxtaposing different terranes of the northern and southern Borborema province.