c-axis transport and phenomenology of the pseudo-gap state in Bi2Sr2CaCu2O8+δBi_2Sr_2CaCu_2O_{8+\delta}

We measure and analyze the resistivity of $Bi_2Sr_2CaCu_2O_{8+\delta}$ crystals for different doping $\delta$. We obtain the fraction of carrier $\eta(T,\delta) = n_g/n_{TOT}$ that do not participate to the c-axis conductivity. All the curves $\eta(T,\delta)$ collapse onto a universal curve when plotted against a reduced temperature $x=[T-\Theta(\delta)]/\Delta^{*}(\delta)$. We find that at the superconducting transition $n_g$ is doping independent. We also show that a magnetic field up to 14 T does not affect the degree of localization in the (a,b) planes but widens the temperature range of the x-scaling by suppressing the superconducting phase coherence.Comment: 11 pages, 5 figures, submitted to Phys.Rev.

Investigation of the leading and subleading high-energy behavior of hadron-hadron total cross sections using a best-fit analysis of hadronic scattering data

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPIn the present investigation we study the leading and subleading high-energy behavior of hadron-hadron total cross sections using a best-fit analysis of hadronic scattering data. The parametrization used for the hadron-hadron total cross sections at high energy is inspired by recent results obtained by Giordano and Meggiolaro [J. High Energy Phys. 03 (2014) 002] using a nonperturbative approach in the framework of QCD, and it reads sigma(tot) similar to Bln(2)s + Cln s ln ln s. We critically investigate if B and C can be obtained by means of best-fits to data for proton-proton and antiproton-proton scattering, including recent data obtained at the LHC, and also to data for other meson-baryon and baryon-baryon scattering processes. In particular, following the above-mentioned nonperturbative QCD approach, we also consider fits where the parameters B and C are set to B = kappa B-th and C = kappa C-th, where B-th and C-th are universal quantities related to the QCD stable spectrum, while kappa (treated as an extra free parameter) is related to the asymptotic value of the ratio sigma(el)/sigma(tot). Different possible scenarios are then considered and compared.963116FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2013/27060-32015/21855-

A multiband radiometer and data acquisition system for remote sensing field research

Specifications are described for a recently developed prototype multispectral data acquisition system which consists of multiband radiometer with 8 bands between 0.4 and 12.5 micrometers and a data recording module to record data from the radometer and ancillary sources. The systems is adaptable to helicopter, truck, or tripod platforms, as well as hand-held operation. The general characteristics are: (1) comparatively inexpensive to acquire, maintain and operate; (2) simple to operate and calibrate; (3) complete with data hardware and software; and (4) well documented for use by researchers. The instrument system is to be commercially available and can be utilized by many researchers to obtain large numbers of accurate, calibrated spectral measurements. It can be a key element in improving and advancing the capability for field research in remote sensing

Uso e impactos da terceirização na agroindústria nordestina de frutas tropicais.

bitstream/CNPAT-2010/5599/1/Pa-029.pd

Estimation of competition parameters in common bean plants.

The objective of this study was to estimate parameters related to the ability of competing or tolerating competition. The experiments were conducted in three seasons, using eight common bean lines with carioca type grains from different origins. Competition at the plant level was evaluated based on the number of pods, number of grains and grain weight (g plant-1). The following competition-related parameters were estimated with the mean data, using a model similar to the diallel: general competing ability (ci), competition tolerance (tj), specific competing ability (sij) and performance per se of every line (aj). The average performance of lines in self-competition was similar to non-self-competition. None of the lines coupled low competing ability (ci high) with high competition tolerance. Highest estimates of aj and ci were observed in line OPNS 331

Rashba spin-orbit coupling and spin relaxation in silicon quantum wells

Silicon is a leading candidate material for spin-based devices, and two-dimensional electron gases (2DEGs) formed in silicon heterostructures have been proposed for both spin transport and quantum dot quantum computing applications. The key parameter for these applications is the spin relaxation time. Here we apply the theory of D'yakonov and Perel' (DP) to calculate the electron spin resonance linewidth of a silicon 2DEG due to structural inversion asymmetry for arbitrary static magnetic field direction at low temperatures. We estimate the Rashba spin-orbit coupling coefficient in silicon quantum wells and find the $T_{1}$ and $T_{2}$ times of the spins from this mechanism as a function of momentum scattering time, magnetic field, and device-specific parameters. We obtain agreement with existing data for the angular dependence of the relaxation times and show that the magnitudes are consistent with the DP mechanism. We suggest how to increase the relaxation times by appropriate device design.Comment: Extended derivations and info, fixed typos and refs, updated figs and data. Worth a re-downloa

Auto e alocompetição de linhagens de feijão tipo Carioca.

o presente trabalho foi realizado com os objetivos de comparar a auto e alocompetição, estimar parâmetros relacionados à capacidade de exercer ou tolerar a competição e identificar linhagens promissoras para a obtenção de multilinhas