Measurement of the production cross section ratio sigma(chi b2(1P))/sigma(chi b1(1P)) in pp collisions at √s=8TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of diffractive dissociation cross sections in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The role of oxygen vacancies and their location in the magnetic properties of Ce1-xCuxO2-delta nanorods

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Studies on structural, morphological and electrical properties of Ce1-xErxO2-delta (x=0.05-0.20) as solid electrolyte for IT - SOFC

A series of four different powders ceria doped Ce1-xErxO2-delta (0.05 <= x <= 0.20) were synthesized by applying self-propagating reaction at room temperature (SPRT method). SPRT procedure is based on the self-propagating room temperature reaction between metal nitrates and sodium hydroxide, wherein the reaction is spontaneous and terminates extremely fast. The method is known to assure very precise stoichiometry of the final product in comparison with a tailored composition. XRPD, Raman spectroscopy, TEM and BET measurements were used to characterize the nanopowders at room temperature. It was shown that all obtained powders were single phase solid solutions with a fluorite-type crystal structure and all powder particles have nanometric size (about 3-4 nm). Densification was performed at 1550 degrees C, in an air atmosphere for 2 h. XRPD, SEM and complex impedance method measurements were carried out on sintered samples. Single phase form was evidenced for each sintered materials. The best value of conductivity at 700 degrees C amounted to 1.10 x 10(-2) Omega(-1) cm(-1) for Ce0.85Er0.O-3(2-delta) sample. Corresponding activation energies of conductivity amounted to 0.28 eV in the temperature range 500-700 degrees C. (C) 2015 Elsevier B.V. All rights reserved.

Optimized delta expansion for relativistic nuclear models

The optimized delta-expansion is a nonperturbative approach for field theoretic models which combines the techniques of perturbation theory and the variational principle. This technique is discussed in the lambda phi(4) model and then implemented in the Walecka model for the equation of state of nuclear matter. The results obtained with the delta expansion are compared with those obtained with the traditional mean field, relativistic Hartree and Hartree-Fock approximations.

Anelastic behavior due to interstitial oxygen in SmBa(2)Cu(3)O7-delta

The composite SmBa2Cu3O7-delta (Sm-123), obtained by the substitution of the ion Y for Sm in the very well known and studied YBa2Cu3O7-delta (Y-123), is potentially attractive for better understanding superconductivity mechanisms and for its applications as electronic devices. Sm-123 samples show higher critical temperatures than Y-123 ones do and a larger solubility of Sm in Ba-Cu-O solvent, which makes their growth process faster. When oxygen is present interstitially, it strongly affects the physical properties of the material. The dynamics of oxygen can be investigated by anelastic spectroscopy measurements, a powerful technique for the precise determination of the oscillation frequency and the internal friction when atomic jumps are possible. Anelastic spectroscopy allows determining the elasticity modulus (related to the oscillation frequency) and the elastic energy loss (related to the internal friction) as a function of the temperature. The sample was also investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), and electric resistivity. The results obtained show a thermally activated relaxation structure composed by at least 3 relaxation processes. These processes may be attributed to the jumps of oxygen atoms present of the Cu-O plane in the orthorhombic phase.

A new limit of the AdS(5) x S-5 sigma model

Using the pure spinor formalism, a quantizable sigma model has been constructed for the superstring in an AdS(5) X S-5 background with manifest PSU(2,2 vertical bar 4) invariance. The PSU(2,2 vertical bar 4) metric g(AB) has both vector components gab and spinor components g, 3, and in the limit where the spinor components g, 3 are taken to infinity, the AdS5 X S5 sigma model reduces to the worldsheet action in a flat background. In this paper, we instead consider the limit where the vector components g(ab) are taken to infinity. In this limit, the AdS5 X S5 sigma model simplifies to a topological A-model constructed from fermionic N=2 superfields whose bosonic components transform like twistor variables. Just as d=3 Chern-Simons theory can be described by the open string sector of a topological A-model, the open string sector of this topological A-model describes d=4 N=4 super-Yang-Mills. These results might be useful for constructing a worldsheet proof of the Maldacena conjecture analogous to the Gopakumar-Vafa-Ooguri worldsheet proof of Chern-Simons/conifold duality.

Traceability of poultry offal meal in broiler feeding using isotopic analysis (delta C-13 and delta N-15) of different tissues

Our goal was to trace the inclusion of poultry offal meal (OM) in diets by using carbon (13C/12C) and nitrogen (15N/14N) isotopic ratios of different tissues in order to contribute for the development of an independent technology for the certification of the feeding of broilers reared on diets with no addition of animal ingredients. Eighty one-day-old chicks were randomly distributed into five experimental treatments, that is, diets containing increasing levels of OM inclusion (0, 2, 4, 8 and 16% OM), with four replicates of four birds each. At 42 days of age, four birds per treatment (n=4) were randomly selected, weighed, and sacrificed to collect breast muscle (Pectoralis major), keel and tibia samples to determine their isotopic ratios (13C/12C e 15N/14N). It was observed that 13C and 15N enrichment increased as a function of increasing OM inclusion in all diets. The analyses of the Pectoralis major showed that that only treatments with 8 and 16% OM dietary inclusion were different form those in the control group (0% OM). on the other hand, when the keel and tibia were analyzed, in addition to 8 and 16% OM), the treatment with 4% OM inclusion was also different from the control group. The use of isotopic ratios of stable carbon and nitrogen isotopes is an alternative to trace OM inclusion in broiler diets as it is capable of tracing OM levels below those usually practiced by the poultry industry in Brazil.

Perturbative super-Yang-Mills from the topological AdS 5 × S 5 sigma model

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oxygen Interstitial Dynamics in Bi(2)Sr(2)CaCu(2)O(8+delta) Oxides Measured by Mechanical Spectroscopy

Many researchers became interested in the discovery of Bi(2)Sr(2)CaCu(2)O(8+delta) oxides with critical temperature of around 80 K. It is known that the critical temperature is related to the CuO2 planes of the material. For this reason, the study of the interstitial oxygen in these oxides is of great relevance. The samples were prepared by means of conventional solid state reactions, through the stoichiometric mixture of precursory powders. After the sinterization, the samples were submitted to measurements of density, electrical resistivity, x-ray diffraction, scanning electron microscopy and energy dispersion spectroscopy, with the objective of performing their characterization. The measurements of mechanical spectroscopy were performed by a torsion pendulum. The results show three relaxation processes in the temperature range of 200 and 700 K, with activation energy of approximately 0.9 eV, which has been attributed to the dynamics of the interstitial oxygen present in the material.

In vitro production of bovine embryos using Sigma antioxidant supplement®, α-tocopherol and L-ascorbic acid

This study tested the effect of Sigma antioxidant supplement®, α-tocopherol (vitamin E) and L-ascorbic acid (vitamin C) in the culture medium of bovine embryos. In experiment 1, in vitro produced bovine zygotes were cultured in Human Tubal Fluid (HTF): Eagle’s Basic Medium (BME) with: Group 1 – 50 µm vitamin C; Group 2 – 200 µm vitamin E; Group 3 – 25 µm vitamin C and 100 µm vitamin E; Group 4 – 1 µl/ml Sigma antioxidant supplement®; and the Control group – HTF:BME only. In experiment 2, embryos were cultured in high or low oxygen tension with HTF:BME + Sigma antioxidant supplement® or in HTF:BME alone (Control). The data were analyzed using ANOVA followed by Tukey’s test. The results of experiment 1 showed a negative effect (P < 0.05) of vitamin E on blastocyst production in Group 2 (19.7 ± 0.1%). This effect was reduced in Group 3 by the addition of vitamin C (26.1 ± 0.2%). The use of vitamin C alone (34.9 ± 0.3%) or the Sigma antioxidant supplement® (33.3 ± 0.7%) did not increase (P > 0.05) the number of blastocysts produced compared with the control group (30.1 ± 0.5%). During experiment 2, there was no effect (P > 0.05) from the culture medium or the O2 concentrations used, indicating that the reduction of the O2 concentration did not improve blastocyst production.

Determinação da fase lactente-ruminante de cordeiros pela técnica do delta 13C

This study was conducted at University of Marília, São Paulo State, Brazil, aiming to determine the phase of intake transition between exclusively liquid diet (milk) and diet based on milk, grass and/or ration by lambs by δ13C technique. Six Suffolk crossbreeding lambs were distributed in a totally random design (3x2), with two experimental groups and three replications. At the first one, lambs were penned and sucked milk from dams fed with C4 diet. besides, they had access to C3 ration in creep feeding, since their birth. At the second group, lambs were kept on a paddock with Tifton – 85 grass (C4 photosynthetic way) as well as their dams and had access to C3 ration in creep feeding, since their birth. The C3 ration contained soybean meal, ground oat grains, lucerne hay and also mineral salt. The penned lambs’ ration consumption overcame the milk intake at 30-35 days after birth; however, grazing lambs ingested more milk and pasture than ration until 40 days after birth. The δ 13C technique was considered effective on studies of lambs feeding behavior.