GLOBAL WELL-POSEDNESS AND NON-LINEAR STABILITY OF PERIODIC TRAVELING WAVES FOR A SCHRODINGER-BENJAMIN-ONO SYSTEM

The objective of this paper is two-fold: firstly, we develop a local and global (in time) well-posedness theory for a system describing the motion of two fluids with different densities under capillary-gravity waves in a deep water flow (namely, a Schrodinger-Benjamin-Ono system) for low-regularity initial data in both periodic and continuous cases; secondly, a family of new periodic traveling waves for the Schrodinger-Benjamin-Ono system is given: by fixing a minimal period we obtain, via the implicit function theorem, a smooth branch of periodic solutions bifurcating a Jacobian elliptic function called dnoidal, and, moreover, we prove that all these periodic traveling waves are nonlinearly stable by perturbations with the same wavelength.

POSITIVITY PROPERTIES OF THE FOURIER TRANSFORM AND THE STABILITY OF PERIODIC TRAVELLING-WAVE SOLUTIONS

In this paper we establish a method to obtain the stability of periodic travelling-wave solutions for equations of Korteweg-de Vries-type u(t) + u(p)u(x) - Mu(x) = 0, with M being a general pseudodifferential operator and where p >= 1 is an integer. Our approach uses the theory of totally positive operators, the Poisson summation theorem, and the theory of Jacobi elliptic functions. In particular we obtain the stability of a family of periodic travelling waves solutions for the Benjamin Ono equation. The present technique gives a new way to obtain the existence and stability of cnoidal and dnoidal waves solutions associated with the Korteweg-de Vries and modified Korteweg-de Vries equations, respectively. The theory has prospects for the study of periodic travelling-wave solutions of other partial differential equations.

DEVELOPMENT OF STATIC MIXERS FOR MISCIBLE FLUIDS IN LAMINAR FLOW WITH THE USE OF COMPUTATIONAL FLUID DYNAMICS (CFD)

Static mixers with improved performance were developed from CFD simulations in a stepwise approach. The relevant geometric features of simple mixer designs and the corresponding mixing mechanisms-laminar shear, elongational flow, and distributive mixing-were identified first. This information was used to formulate guidelines for the development of new geometries. The solid elements of the static mixer should: (a) provide restrictions to the flow; (b) deflect the flow; (c) be sequentially rotated around the flow direction to provide symmetry; (d) extend from the center of the pipe to the vicinity of the walls to avoid short-circuiting; and (e) distribute and remix the flow. Based on these guidelines, two improved mixer designs were developed: the DS A-I mixer has a good mixing efficiency and an acceptable pressure drop; the Fins 35 degrees mixer is more efficient and compact, but requires a larger pressure drop. Their performance indicates that their use is possible on industrial applications.

Validation of a manual headspace gas chromatography method for determining volatile compounds in biological fluids

Background: We report the validation of a method for the determination of acetaldehyde, acetone, methanol, and ethanol in biological fluids using manual headspace sample introduction and an acetonitrile internal standard. Method: This method uses a capillary column (I = 30 m, I.D. = 0.25 mm, dF = 0.25 mu m) installed in a gas chromatography-flame ionization detector (GC-FID) apparatus with a run time of 7.5 minutes. Results: Analysis of the retention times and the resolution of the analyte peaks demonstrated excellent separation without widening of the peaks. Precision and accuracy were good (interassay precision < 15% and recovery between 85% and 115%) in both blood and urine. Conclusion: The method was linear (r > 0.09) over the analytical measurement range (AMR) of each analyte.

Gene Expression Profiles Stratified according to Type 1 Diabetes Mellitus Susceptibility Regions

The MHC region (6p21) aggregates the major genes that contribute to susceptibility to type 1 diabetes (T1D). Three additional relevant susceptibility regions mapped on chromosomes 1p13 (PTPN22), 2q33 (CTLA-4), and 11p15 (insulin) have also been described by linkage studies. To evaluate the contribution of these susceptibility regions and the chromosomes that house these regions, we performed a large-scale differential gene expression on lymphomononuclear cells of recently diagnosed T1D patients, pinpointing relevant modulated genes clustered in these regions and their respective chromosomes. A total of 4608 cDNAs from the IMAGE library were spotted onto glass slides using robotic technology. Statistical analysis was carried out using the SAM program, and data regarding gene location and biological function were obtained at the SOURCE, NCBI, and FATIGO programs. Three induced genes were observed spanning around the MHC region (6p21-6p23), and seven modulated genes (5 repressed and 2 repressed) were seen spanning around the 6q21-24 region. Additional modulated genes were observed in and around the 1p13, 2q33, and 11p15 regions. Overall, modulated genes in these regions were primarily associated with cellular metabolism, transcription factors and signaling transduction. The differential gene expression characterization may identify new genes potentially involved with diabetes pathogenesis.

Detection of Leptospira spp. in semen and vaginal fluids of goats and sheep by polymerase chain reaction

Thirteen goat herds and seven sheep flocks in the state of Rio de Janeiro, Brazil were screened for leptospirosis. From the three herds and three flocks with greatest seroreactivity, 19 goats (16 females and three bucks) and 40 sheep (26 ewes and 14 rams) that were seropositive (specific anti-Leptospira titres >= 400, based on a microscopic agglutination test), were selected for more detailed studies. From those animals, samples of vaginal fluids or semen were collected for bacteriological and molecular assays. For both species of animals, the most prevalent reactions were to serovars Hardjo, Shermani, and Grippotyphosa. Although leptospires were detected by darkfield microscopy in three vaginal fluid samples (from two goats and one ewe), pure isolates were not obtained by bacteriological culture of vaginal fluids or semen. However, seven vaginal fluid samples (from four goats and three ewes) and six semen samples (all from rams) were positive on polymerase chain reaction (PCR). Based on these findings, in addition to analogous findings in cattle, we inferred that there is potential for venereal transmission of leptospirosis in small ruminants. (c) 2008 Elsevier Inc. All rights reserved.

An evaluation of three upwinding approximations for numerical modeling the flow in tubular membrane of Newtonian and non-Newtonian fluids

In this paper, the laminar fluid flow of Newtonian and non-Newtonian of aqueous solutions in a tubular membrane is numerically studied. The mathematical formulation, with associated initial and boundary conditions for cylindrical coordinates, comprises the mass conservation, momentum conservation and mass transfer equations. These equations are discretized by using the finite-difference technique on a staggered grid system. Comparisons of the three upwinding schemes for discretization of the non-linear (convective) terms are presented. The effects of several physical parameters on the concentration profile are investigated. The numerical results compare favorably with experimental data and the analytical solutions. (C) 2011 Elsevier Inc. All rights reserved.

Magnetic Fluids Based on gamma-Fe(2)O(3) and CoFe(2)O(4) Nanoparticles Dispersed in Ionic Liquids

The disclosure of magnetic ionic liquids (MILs) as stable dispersions of surface modified gamma-Fe(2)O(3) or CoFe(2)O(4) nanoparticles (NPs) in the 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIBF(4)) ionic liquid is reported. The magnetic NPs were characterized by X-ray powder diffraction, transmission electron microscopy, and Raman spectroscopy. The surface modified NPs have proved to form stable dispersions in BMIBF(4) in the absence of water and behave like a magnetic ionic liquid. The MILs have been characterized by Raman spectroscopy, magnetic measurements, and DSC. The stability of the magnetic NPs in BMIBF(4) is consistently explained by assuming the formation of a semiorganized protective layer composed of supramolecular aggregates in the form of [(BMI)(2)(BF(4))(3)](-). A superparamagnetic behavior and saturation magnetization of ca. 18 emu/g for a sample containing 30% w/w maghemite NPs/BMIBF(4) have been inferred from static and dynamic magnetic measurements. DSC results have shown that the MIL composed of 30% w/w CoFe(2)O(4) NPs/BMIBF(4) remains a liquid phase down to -84 degrees C.

Pinguino In-bearing polymetallic vein deposit, Deseado Massif, Patagonia, Argentina: characteristics of mineralization and ore-forming fluids

The Pinguino deposit, located in the low sulfidation epithermal metallogenetical province of the Deseado Massif, Patagonia, Argentina, represents a distinct deposit type in the region. It evolved through two different mineralization events: an early In-bearing polymetallic event that introduced In, Zn, Pb, Ag, Cd, Au, As, Cu, Sn, W and Bi represented by complex sulfide mineralogy, and a late Ag-Au quartz-rich vein type that crosscut and overprints the early polymetallic mineralization. The indium-bearing polymetallic mineralization developed in three stages: an early Cu-Au-In-As-Sn-W-Bi stage (Ps(1)), a Zn-Pb-Ag-In-Cd-Sb stage (Ps(2)) and a late Zn-In-Cd (Ps(3)). Indium concentrations in the polymetallic veins show a wide range (3.4 to 1,184 ppm In). The highest indium values (up to 1,184 ppm) relate to the Ps(2) mineralization stage, and are associated with Fe-rich sphalerites, although significant In enrichment (up to 159 ppm) is also present in the Ps(1) paragenesis associated with Sn-minerals (ferrokesterite and cassiterite). The hydrothermal alteration associated with the polymetallic mineralization is characterized by advanced argillic alteration within the immediate vein zone, and sericitic alteration enveloping the vein zone. Fluid inclusion studies indicate homogenisation temperatures of 308.2-327A degrees C for Ps(1) and 255-312.4A degrees C for Ps(2), and low to moderate salinities (2 to 5 eq.wt.% NaCl and 4 to 9 eq.wt.% NaCl, respectively). delta(34)S values of sulfide minerals (+0.76aEuro degrees to +3.61aEuro degrees) indicate a possible magmatic source for the sulfur in the polymetallic mineralization while Pb isotope ratios for the sulfides and magmatic rocks ((206)Pb/(204)Pb, (207)Pb/(204)Pb and (208)Pb/(204)Pb ratios of 17.379 to 18.502; 15.588 to 15.730 and 38.234 to 38.756, respectively) are consistent with the possibility that the Pb reservoirs for both had the same crustal source. Spatial relationships, hydrothermal alteration styles, S and Pb isotopic data suggest a probable genetic relation between the polymetallic mineralization and dioritic intrusions that could have been the source of metals and hydrothermal fluids. Mineralization paragenesis, alteration mineralogy, geochemical signatures, fluid inclusion data and isotopic data, confirm that the In-bearing polymetallic mineralization from Pinguino deposit is a distinct type, in comparison with the well-known epithermal low sulfidation mineralization from the Deseado Massif.

Structural Investigation of MFe(2)O(4) (M = Fe, Co) Magnetic Fluids

Ferrites of the type M(II)Fe(2)O(4) (M = Fe and Co) have been prepared by the traditional coprecipitation method. These ferrites were modified by the adsorption of fatty acids derived from soybean and castor oil and were then dispersed in cyclohexane, providing very stable magnetic fluids, readily usable in nonpolar media. The structural properties of the ferrites and modified ferrites as well as the magnetic fluids were characterized by XRD (X-ray powder diffraction), TEM (transmission electron microscopy), DRIFTS (diffusion reflectance infrared Fourier transform spectroscopy), FTMR (Fourier transform near-infrared), UV-vis, normal Raman spectroscopy, and surface-enhanced Raman scattering (SERS). XRD and TEM analysis have shown that the magnetic nanoparticles (nonmodified and modified) present diameters in the range of 10-15 nm. DRIFTS measurements have shown that the carboxylate groups of soybean and castor oil fatty acids adsorb on the ferrite surface, forming three different structures: a bridging bidentate, a bridging monodentate, and a bidentate chelate structure. The FTIR and Raman spectra of nonmodified Fe(3)O(4) and CoFe(2)O(4) nanoparticles have shown that the number of observed phonons is not compatible with the expected O(h)(7) symmetry, since IR-only active phonons were observed. in the Raman spectra and vice versa. SERS measurements of a CoFe(2)O(4) thin film on a SERS-active gold electrode at different applied potentials made possible the assignment of the signals near 550 and 630 cm(-1) to Co-O motions and the signals near 470 and 680 cm(-1) to Fe-O motions.

Congenital eruption cyst: a case report

Congenital pathologies are those existing at or dating from birth. Occurrence of congenital cystic lesions in the oral cavity is uncommon in neonates. Eruption cyst (EC) is listed among these unusual lesions. It occurs within the mucosa overlying teeth that are about to erupt and, according to the current World Health Organization (WHO) classification of epithelial cysts of the jaws, EC is a separate entity. This paper presents a case of congenital EC successfully managed by close monitoring of the lesion, without any surgical procedure or tooth extraction. Eruption of the teeth involved, primary central incisors, occurred at the fourth month of age. During this time neither the child nor mother had any complication such as pain on sucking, refusal to feed, airway obstruction, or aspiration of fluids or teeth.

Estudo morfofuncional das glândulas mamárias de Mão Pelada, Procyon cancrivorus

Para a descrição macro e microscópica das glândulas mamárias foram utilizadas três fêmeas de Mão Pelada (Procyon cancrivorus). As amostras das glândulas foram processadas conforme técnicas rotineiras para histologia. As fêmeas estudadas apresentaram 3 pares de glândulas mamárias, sendo um par de glândula mamária abdominal cranial, um par de abdominal caudal e um par de inguinal. As papilas mamárias apresentaram formato pendular, como os canídeos domésticos. Microscopicamente, a glândula mamária apresentou da porção externa para a interna: epiderme (epitélio estratificado pavimentoso queratinizado), derme (tecido conjuntivo frouxo e tecido conjuntivo denso não modelado), fibras musculares lisas e ductos papilíferos que abrem em vários ósteos papilares em formato de "chuveiro". A porção secretora glandular era caracteristicamente túbulo alveolar, com células cuboidais dispostas em camada simples. Os resultados indicam que o conjunto glandular estudado é semelhante ao da cadela (Cannis familiaris) tanto em seu aspecto macroscópico quanto em seu aspecto microscópico, este fato sugere que podemos utilizar o Mão Pelada e o Cão como modelos similares de estudo, para identificação de patologias relacionadas a este sistema.

Forced convection to laminar flow of liquid egg yolk in circular and annular ducts

The steady-state heat transfer in laminar flow of liquid egg yolk - an important pseudoplastic fluid food - in circular and concentric annular ducts was experimentally investigated. The average convection heat transfer coefficients, determined by measuring temperatures before and after heating sections with constant temperatures at the tube wall, were used to obtain simple new empirical expressions to estimate the Nusselt numbers for fully established flows at the thermal entrance of the considered geometries. The comparisons with existing correlations for Newtonian and non-Newtonian fluids resulted in excellent agreement. The main contribution of this work is to supply practical and easily applicable correlations, which are, especially for the case of annulus, rather scarce and extensively required in the design of heat transfer operations dealing with similar shear-thinning products. In addition, the experimental results may support existing theoretical analyses.

Bose-Einstein condensation in 87Rb: characterization of the Brazilian experiment

We describe the experimental apparatus and the methods to achieve Bose-Einstein condensation in 87Rb atoms. Atoms are first laser cooled in a standard double magneto-optical trap setup and then transferred into a QUIC trap. The system is brought to quantum degeneracy selectively removing the hottest atoms from the trap by radio-frequency radiation. We also present the main theoretical aspects of the Bose-Einstein condensation phenomena in atomic gases.

Rare earth element and yttrium geochemistry applied to the genetic study of cryolite ore at the Pitinga Mine (Amazon, Brazil)

This work aims at the geochemical study of Pitinga cryolite mineralization through REE and Y analyses in disseminated and massive cryolite ore deposits, as well as in fluorite occurrences. REE signatures in fluorite and cryolite are similar to those in the Madeira albite granite. The highest ΣREE values are found in magmatic cryolite (677 to 1345 ppm); ΣREE is lower in massive cryolite. Average values for the different cryolite types are 10.3 ppm, 6.66 ppm and 8.38 ppm (for nucleated, caramel and white types, respectively). Disseminated fluorite displays higher ΣREE values (1708 and 1526ppm) than fluorite in late veins(34.81ppm). Yttrium concentration is higher in disseminated fluorite and in magmatic cryolite. The evolution of several parameters (REEtotal, LREE/HREE, Y) was followed throughout successive stages of evolution in albite granites and associated mineralization. At the end of the process, late cryolite was formed with low REEtotal content. REE data indicate that the MCD was formed by, and the disseminated ore enriched by (additional formation of hydrothermal disseminated cryolite), hydrothermal fluids, residual from albite granite. The presence of tetrads is poorly defined, although nucleated, caramel and white cryolite types show evidence for tetrad effect.