Caracterização por microscopia óptica e eletrônica de varredura de amostras da madeira de pínus submetidas à compressão axial.

EVINCI. Resumo 048

Kajian Psikologi Wanita Tokoh Utama Novel Air Mata Tuhan Karya Aguk Irawan M.n.

A novel entitled Air Mata Tuhan as a study of woman psychology was focused on the main character. This research aimed to know the forms of women's personality, and to describe the linkage between structural elements and psychology aspect contained on the main character in the Novel entitled Air Mata Tuhan written by Aguk Irawan M.N. The used research method was qualitative by using literature study. The data contained in the Novel entitled Air Mata Tuhan were also analyzed. The research result indicated that structural elements included title, theme, characterization, character, and conflict has the linkage. The analysis of woman psychology showed that (1) the woman characteristic was beauty included beauty of inside and outside, tenderness, humility, nurturing, easily disappointed and rise up again; (2) woman and family, included woman as a wife, woman as a partner of life; and (3) woman and depression. Those characteristics were belonged to the main character in the Novel entitled Air MataTuhan named Fisha

Algebraic renormalization of the BF Yang-Mills Theory

We discuss the quantum equivalence, to all orders of perturbation theory, between the Yang-Mills theory and its first order formulation through a second rank antisymmetric tensor field. Moreover, the introduction of an additional nonphysical vector field allows us to interpret the Yang-Mills theory as a kind of perturbation of the topological BF model.Comment: 14 pages, some references and acknowledgments added, version to appear in Phys.Lett.

Ultra--Planck Scattering in D=3 Gravity Theories

We obtain the high energy, small angle, 2-particle gravitational scattering amplitudes in topologically massive gravity (TMG) and its two non-dynamical constituents, Einstein and Chern--Simons gravity. We use 't Hooft's approach, formally equivalent to a leading order eikonal approximation: one of the particles is taken to scatter through the classical spacetime generated by the other, which is idealized to be lightlike. The required geometries are derived in all three models; in particular, we thereby provide the first explicit asymptotically flat solution generated by a localized source in TMG. In contrast to $D$=4, the metrics are not uniquely specified, at least by naive asymptotic requirements -- an indeterminacy mirrored in the scattering amplitudes. The eikonal approach does provide a unique choice, however. We also discuss the discontinuities that arise upon taking the limits, at the level of the solutions, from TMG to its constituents, and compare with the analogous topologically massive vector gauge field models.Comment: 20 pages, preprint BRX TH--337, DAMTP R93/5, ADP-93-204/M1

Evaluation of an optimized enzymatic biosensor for ethanol used in apple storage management with low oxygen stress

Ethanol has been proposed to be one of the target molecules to monitor the dynamic controlled atmosphere (DCA) technique during apple storage, measured in the squeezed juice or in the air of the storage chamber. One of the proposed commercial sensors for ethanol in apple juice is based on amperometry, after a two-step enzyme-based reaction that involves a diaphorase and an alcohol-dehydrogenase. Even though this method has been reported to overestimate ethanol, this difference is fairly fixed and it is industrially used to check the correct application of the treatment and to set the gas composition protocols when the maximum acceptable ethanol is reached. During the 2018 harvest, the ethanol concentration in juices measured with the commercial sensor appeared much higher than those usually reported in precedent years, particularly for the lower concentrations. Laboratory experiments suggested that differences between years could be due to the presence of a secondary enzyme activity present in the commercial diaphorase employed. In order to increase the sensitivity and accuracy, it has been evaluated the performance of the biosensor emploting a further diaphorase. The performances of both sensors were compared with those obtained with a gaschromatophy mass spectrometry approach after head space extraction (HS-GC-MS) in which the mass spectra was acquired in selected-ion monitoring mode. Samples belonging to ‘Red Delicious’ cv. were picked up at different temporary points from industrial storage rooms following the application of low oxygen stress. The new biosensor reduced 97% the mean difference respect to the values obtained with the GC-MS method. The difference between sensors was even clearer for samples with concentrations up to 100 mg/L, that could be used as a discriminating value for the evaluation of the technique success in ‘Red Delicious’ apple juice. The increased sensitivity of the sensor allowed a more accurate monitoring of the DCA at industrial conditions, limiting the risks linked to a false positive on the monitoring during storage

The BF Formalism for QCD and Quark Confinement

Using the BF version of pure Yang-Mills, it is possible to find a covariant representation of the 't Hooft magnetic flux operator. In this framework, 't Hooft's pioneering work on confinement finds an explicit realization in the continuum. Employing the Abelian projection gauge we compute the expectation value of the magnetic variable and find the expected perimeter law. We also check the area law behaviour for the Wilson loop average and compute the string tension which turns out to be of the right order of magnitude.Comment: Various changes, version to appear in Nucl.Phys.

Resistência natural das espécies Eucalyptus cloeziana, Eucalyptus mycrocoris, Eucalyptus umbra, Corymbia citriodora e Corymbia maculata à degradação provocada pelo fungo Agrocybe perfecta, causador da podridão branca na madeira, in vitro.

Estudos práticos para a avaliação da resistência natural da madeira de eucalipto, têm recebido considerável atenção dos pesquisadores, em virtude das orientações que fornecem sobre o uso final do produto, evitando perdas econômicas. O apodrecimento da madeira pode ser causado por fungos decompositores. Alguns apresentam alta capacidade de degradação da lignina, cuja degradação é denominada podridão-branca. O objetivo deste trabalho foi analisar, em laboratório, a resistência natural da madeira de cinco espécies de eucalipto, a degradação provocada pelo fungo Agrocybe perfecta na madeira em diferentes posições ao longo do fuste.EBRAMEM

Data-driven simulation and characterisation of gold nanoparticle melting

The simulation and analysis of the thermal stability of nanoparticles, a stepping stone towards their application in technological devices, require fast and accurate force fields, in conjunction with effective characterisation methods. In this work, we develop efficient, transferable, and interpretable machine learning force fields for gold nanoparticles based on data gathered from Density Functional Theory calculations. We use them to investigate the thermodynamic stability of gold nanoparticles of different sizes (1 to 6 nm), containing up to 6266 atoms, concerning a solid-liquid phase change through molecular dynamics simulations. We predict nanoparticle melting temperatures in good agreement with available experimental data. Furthermore, we characterize the solid-liquid phase change mechanism employing an unsupervised learning scheme to categorize local atomic environments. We thus provide a data-driven definition of liquid atomic arrangements in the inner and surface regions of a nanoparticle and employ it to show that melting initiates at the outer layers