Exact results on spin dynamics and multiple quantum dynamics in alternating spin-1/2 chains with XY-Hamiltonian at high temperatures

We extend the picture of a transfer of nuclear spin-1/2 polarization along a homogeneous one-dimensional chain with the XY-Hamiltonian to the inhomogeneous chain with alternating nearest neighbour couplings and alternating Larmor frequencies. To this end, we calculate exactly the spectrum of the spin-1/2 XY-Hamiltonian of the alternating chain with an odd number of sites. The exact spectrum of the XY-Hamiltonian is also applied to study the multiple quantum (MQ) NMR dynamics of the alternating spin-1/2 chain. MQ NMR spectra are shown to have the MQ coherences of zero and $\pm$ second orders just as in the case of a homogeneous chain. The intensities of the MQ coherences are calculated.Comment: 10 pages, 4 figure

Spectroscopy of 50^{50}Sc and ab initio calculations of B(M3)B(M3) strengths

The GRIFFIN spectrometer at TRIUMF-ISAC has been used to study excited states and transitions in $^{50}$Sc following the $\beta$-decay of $^{50}$Ca. Branching ratios were determined from the measured $\gamma$-ray intensities, and angular correlations of $\gamma$ rays have been used to firmly assign the spins of excited states. The presence of an isomeric state that decays by an $M3$ transition with a $B(M3)$ strength of 13.6(7)\,W.u. has been confirmed. We compare with the first {\it ab initio} calculations of $B(M3$) strengths in light and medium-mass nuclei from the valence-space in-medium similarity renormalization group approach, using consistently derived effective Hamiltonians and $M3$ operator. The experimental data are well reproduced for isoscalar $M3$ transitions when using bare $g$-factors, but the strength of isovector $M3$ transitions are found to be underestimated by an order of magnitude

Efeito da aplicação de tratamentos pós-colheita na conservação de raízes de mandioca.

O objetivo deste trabalho foi avaliar a eficiência do revestimento com fécula de mandioca ou parafina na conservação da qualidade pós-colheita de raízes de mandioca armazenadas sob condições ambiente por 9 dias. Após a lavagem e sanitização, as raízes foram revestidas com fécula de mandioca na concentração de 5% ou parafina aquecida a 60 oC e acomodadas em bandejas de poliestireno expandido ? EPS (Isopor®) mantidas sob temperatura ambiente. Como controle foram utilizadas raízes sem recobrimento. As análises foram realizadas diariamente, durante 9 dias de armazenamento, sendo avaliada a perda de massa, tempo de cozimento, aparência visual, umidade, pH e acidez titulável. Por meio de identificação visual, observou-se que o escurecimento vascular foi o principal sintoma de deterioração nas mandiocas. Nas raízes que não sofreram qualquer tratamento e naquelas submetidas ao tratamento com revestimento de fécula, os sintomas de deterioração apareceram no terceiro dia de armazenamento, em cerca de 50% das raízes. Nas mandiocas submetidas ao tratamento com revestimento de parafina, os primeiros sintomas internos foram observados no quarto dia de armazenamento, em 33,3% das raízes analisadas. O revestimento com parafina foi responsável também por menor perda de massa e menor tempo de cozimento das raízes ao longo de todo o período de armazenamento. Para a análise de umidade, observaram-se teores variando de 57,9% a 64,7%. Para as análises de pH e acidez titulável verificou-se oscilação nos resultados ao longo do período de armazenamento para os três tratamentos estudados.bitstream/item/31764/1/BPD74.pdfVersão eletrônica. 1ª impressão: 2010

Comparação entre composto de lixo orgânico, esterco de curral e húmus de minhoca.

bitstream/item/48918/1/Boletim-PD-07-AMAZ-ORIENTAL.pd

Efeito do composto de lixo orgânico urbano de Barcarena na produção de matéria seca de milho em casa de vegetação.

bitstream/item/40519/1/Boletim-Pesquisa-26-CPATU.pd

H^+ -> W^+ l_i^- l_j^+$ decay in the two Higgs doublet model

We study the lepton flavor violating H^+ -> W^+ l_i^- l_j^+ and the lepton flavor conserving $H^+ -> W^+ l_i^- l_i^+ (l_i=\tau, l_j=\mu) decays in the general 2HDM, so called model III. We estimate the decay width \Gamma for LFV (LFC) at the order of the magnitude of (10^{-11}-10^{-5}) GeV ((10^{-9}-10^{-4}) GeV), for 200 GeV\leq m_{H^\pm}\leq 400 GeV, and the intermediate values of the coupling \bar{\xi}^{E}_{N,\tau \mu}\sim 5 GeV (\bar{\xi}^{E}_{N,\tau \tau}\sim 30 GeV). We observe that the experimental result of the process under consideration can give comprehensive information about the physics beyond the standard model and the existing free parameters.Comment: 8 pages, 7 Figure

First order phase transition from the vortex liquid to an amorphous solid

We present a systematic study of the topology of the vortex solid phase in superconducting Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$ samples with low doses of columnar defects. A new state of vortex matter imposed by the presence of geometrical contours associated with the random distribution of columns is found. The results show that the first order liquid-solid transition in this vortex matter does not require a structural symmetry change.Comment: 4 pages, 5 figure

Physiological and vegetative behavior of banana cultivars under irrigation water salinity.

he purpose of the study was to evaluate the effect of salinity levels of irrigation water on physiology and growth of banana cultivars during the vegetative stage. The experiment was carried out following a completely randomized design in split plots, with four levels of salinity in irrigation water (0.5, 2.0, 3.0 and 4.0 dS m-1) and fourbanana cultivars (Pacovan, Prata Anã, BRS Platina and Princesa) with three repetitions. Stomatal conductance, transpiration, relative water content, leaf water potential and proline concentration were evaluated at 150 days after transplanting (DAT), besides plant height, stem diameter and leaf area. All variables showed sensitivity to the increase of salinity level of irrigation water. The results of soil water extraction, relative water content in leaf (RWC), leaf water potential and proline content differed (p ? 0.05) among the cultivars. Prata Anã and BRS Platina cultivars were the ones with lowest sensitivity, while Pacovan and BRS Princesa cultivars showed larger variation of soil water extraction and RWC with the increase in irrigation water salinity (electrical conductivity), being considered the ones of highest sensitivity to salinity in this study. Banana crop growth as a consequence of physiological effects was inhibited by the increase in water salinity, mainly in ?BRS Princesa? cultiva

Polarizing Bubble Collisions

We predict the polarization of cosmic microwave background (CMB) photons that results from a cosmic bubble collision. The polarization is purely E-mode, symmetric around the axis pointing towards the collision bubble, and has several salient features in its radial dependence that can help distinguish it from a more conventional explanation for unusually cold or hot features in the CMB sky. The anomalous "cold spot" detected by the Wilkinson Microwave Anisotropy Probe (WMAP) satellite is a candidate for a feature produced by such a collision, and the Planck satellite and other proposed surveys will measure the polarization on it in the near future. The detection of such a collision would provide compelling evidence for the string theory landscape.Comment: Published version. 15 pages, 8 figure

Análise conjunta de caracteres quantitativos e qualitativos em acessos de umbu-cajazeira.

Pertencente à família Anacardiaceae, a umbu-cajazeira é uma frutífera nativa do Nordeste brasileiro, ainda em fase de domesticação, que apresenta acentuada variabilidade em função das variações morfológicas entre frutos (LIMA et al., 2002; CARVALHO et al., 2008). Ocorre espontaneamente no semiárido brasileiro (SILVA JÚNIOR et al., 2004) e seus frutos apresentam ampla perspectiva de aproveitamento agroindustrial. Porém, como sua exploração acontece apenas de forma extrativista, estes são preferencialmente consumidos in natura ou na forma de suco, picolé e sorvete (LIMA et al., 2002; CARVALHO et al., 2008; RITZINGER et al., 2008).pdf 59