Estudo da condutividade hidráulica dos solos na area do entorno do projeto de irrigação salitre

bitstream/CNPS-2010/14865/1/doc92-2007est-condut-hidraulica.pd

Experimental determination of the non-extensive entropic parameter qq

We show how to extract the $q$ parameter from experimental data, considering an inhomogeneous magnetic system composed by many Maxwell-Boltzmann homogeneous parts, which after integration over the whole system recover the Tsallis non-extensivity. Analyzing the cluster distribution of La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ manganite, obtained through scanning tunnelling spectroscopy, we measure the $q$ parameter and predict the bulk magnetization with good accuracy. The connection between the Griffiths phase and non-extensivity is also considered. We conclude that the entropic parameter embodies information about the dynamics, the key role to describe complex systems.Comment: Submitted to Phys. Rev. Let

Higher-Derivative Two-Dimensional Massive Fermion Theories

We consider the canonical quantization of a generalized two-dimensional massive fermion theory containing higher odd-order derivatives. The requirements of Lorentz invariance, hermiticity of the Hamiltonian and absence of tachyon excitations suffice to fix the mass term, which contains a derivative coupling. We show that the basic quantum excitations of a higher-derivative theory of order 2N+1 consist of a physical usual massive fermion, quantized with positive metric, plus 2N unphysical massless fermions, quantized with opposite metrics. The positive metric Hilbert subspace, which is isomorphic to the space of states of a massive free fermion theory, is selected by a subsidiary-like condition. Employing the standard bosonization scheme, the equivalent boson theory is derived. The results obtained are used as a guideline to discuss the solution of a theory including a current-current interaction.Comment: 23 pages, Late

Ab-initio study of the relation between electric polarization and electric field gradients in ferroelectrics

The hyperfine interaction between the quadrupole moment of atomic nuclei and the electric field gradient (EFG) provides information on the electronic charge distribution close to a given atomic site. In ferroelectric materials, the loss of inversion symmetry of the electronic charge distribution is necessary for the appearance of the electric polarization. We present first-principles density functional theory calculations of ferroelectrics such as BaTiO3, KNbO3, PbTiO3 and other oxides with perovskite structures, by focusing on both EFG tensors and polarization. We analyze the EFG tensor properties such as orientation and correlation between components and their link with electric polarization. This work supports previous studies of ferroelectric materials where a relation between EFG tensors and polarization was observed, which may be exploited to study ferroelectric order when standard techniques to measure polarization are not easily applied.Comment: 9 pages, 6 figures, 5 tables, corrected typos, as published in Phys. Rev.

Universality classes for rice-pile models

We investigate sandpile models where the updating of unstable columns is done according to a stochastic rule. We examine the effect of introducing nonlocal relaxation mechanisms. We find that the models self-organize into critical states that belong to three different universality classes. The models with local relaxation rules belong to a known universality class that is characterized by an avalanche exponent $\tau \approx 1.55$, whereas the models with nonlocal relaxation rules belong to new universality classes characterized by exponents $\tau \approx 1.35$ and $\tau \approx 1.63$. We discuss the values of the exponents in terms of scaling relations and a mapping of the sandpile models to interface models.Comment: 4 pages, including 3 figure

Image analysis as a tool for viability and recombinant protein production assessment during E. coli fermentations

The development of monitoring methods for physiological state assessment during recombinant fermentation processes has been encouraged by the need to evaluate the influence of processing conditions in recombinant protein production. In this work, microscopy and image analysis techniques were used for the quantification of viability and protein production in two recombinant E. coli batch fermentations. Images obtained from light microscopy with phase contrast were used to assess the total number of cells in a given sample and, from epifluorescence microscopy, both producing and dead cells were counted using two different filters. This methodology allowed the extraction of information related to cell viability and recombinant protein production. This information, combined with standard fermentation data, allowed the derivation of interesting hypothesis that can be used afterwards for experimental design and further validation. Additionally, the ratios calculated in this work can be complemented with other parameters that can be extracted from image analysis

Caracterização pedológica e estudos de infiltração da água no solo em perímetros irrigados no Vale do Rio São Francisco

bitstream/CNPS-2010/14937/1/bpd97-2006vale-rio-sao-francisco.pd

Perencanaan Pembangkit Listrik Tenaga Mikro Hidro (Pltmh) Memanfaatkan Outlet Kondensor Pltu II NTT di Desa Bolok Kecamatan Kupang Barat, Kabupaten Kupang

Penelitian ini bertujuan untuk melakukan studi perencanaan dan mengetahui seberapa besar tenaga listrik yang dihasilkan dengan memanfaatkan kembali air buangan kondensor menjadi PLTMH dari air buangan kondensor serta pemanfaataan daya listrik pada gedung administrasi di PLTU II NTT. Berdasarkan hasil analisis dan pengukuran diperoleh, rata-rata debit air dari outlet kondensor adalah 0.834 m3/det, dengan ketinggian efektif 8.2 meter. PLTMH menggunakan turbin Cross flow tipe T-14 dengan diameter 710 mm, efisiensi turbin adalah 76% sehingga daya keluaran turbin 47.26 KW, dan untuk membangkitkan daya listrik  digunakan 2 unit generator sinkron 3Ø, 2x25 kVA bertipe STC-20  pada dengan effisiensi generator dan transmiter fatbelty yaitu 85% dan 98%  sehingga daya keluarannya sebesar 39.36 kVA. Dengan asumsi pemakaian listrik di gedung administrasi sebesar 9.7 KW. Lokasi pembangkitan berada berdekatan unit pembangkit PLTU II NTT, sehingga Jaringan tegangan rendah menggunakan kabel NFA2X (3 x 35 + 1 x 25 mm2) dengan panjang penghantar 445 meter dari gedung pembangkit dan menggunakan 11 tiang besi dengan ketinggian 9 meter serta jarak antar tiang 40 meter. Karena panjang penghantar relatif pendek sehingga impedansi salurannya adalah 0.369732 + j0.17129. Nilai jatuh tegangan yang terjadi sebesar  dan 2.46 V (0.6%) dan rugi-rugi daya sebesar 14.48 Watt

Determination of selenium in bovine semen by ICP-MS using formic acid for sample preparation.

Determination of Se by inductively coupled plasma mass spectrometry (ICP-MS) can be difficult due to spectral interferences; however, these interferences can be eliminated by using collision-reaction interface (CRI) technology. A simple and fast procedure for determination of total Se concentration in bovine semen by ICP-MS after sample solubilization with diluted formic acid is here proposed. Formic acid caused an increase of up to 50% in selenium net signals and the maximum gain was obtained at 10% v v-1 formic acid solution. The optimized nebulizer gas flow rates were 1.05 and 0.95 L min-1, and radio frequency applied power were 1.3 and 1.4 kW without and with CRI, respectively. Microwave-assisted acid digestion was also implemented in the preparation of semen sample for comparison of results. No statistical differences between these sample preparation strategies at 95% confidence level (t-test) were observed for 76Se+ , 77Se+ , 78Se+ and 82Se+ without using CRI and 82Se+ with CRI