16 research outputs found
Potencial fitotóxico de extratos foliares de Aloe arborescens Miller (Asphodelaceae) produzidos em diferentes épocas do ano
A fast algorithm for the on-line estimation of polarity correlation using binary patterns
Effect of andrographis paniculata leaf extract on wound healing in rats
This work was carried out to study the effect of topical application of Andrographis paniculata on the rate of wound enclosure and its histological features. A wound was created in four groups of rat in posterior neck region. Blank placebo was applied topically to the wounds of Group 1. Groups 2 and 3 were dressed with placebo containing 5% and 10% extracts of A. paniculata, respectively. Intrasite gel was applied topically to the wounds of Group 4. Macroscopical examination revealed that the rate of wound healing was significantly accelerated in the wound dressed with A. paniculata extract compared to the blank placebo. The wounds dressed with 10% extract or Intrasite gel healed earlier compared to the wounds dressed with placebo containing 5% A. paniculata extract. Histologically, wounds dressed with A. paniculata extracts showed markedly less scar width and contained large amounts of fibroblast proliferation. More collagen and less angiogenesis with absence of inflammatory cells were seen for wounds dressed with 10% A. paniculata compared to the blank placebo. Conclusion, A. paniculata extracts significantly enhanced rate of wound healing in rats. © 2012 Taylor & Francis
Deformation mechanism in compression molding of discontinuous thermoplastic composites
Processing plays a key role in determining the final properties of the product during compression molding of thermoplastic composites. In order to manufacture defect free composite products, the essential material behavior needs to be identified, modeled and characterized. This work focuses on the experimental determination of those mechanisms, that play an important role during the manufacturing of compression molded products. Chopped tapes of unidirectional carbon fiber reinforced thermoplastic composite are used for the compression molding experiments with different processing conditions. A transparent matrix is used with un-impregnated tows to visualize the deformation of flakes and movement of fluid. Experiments reveal that intra flake shear, in plane deformation of flakes (flake spreading, fiber bending) and fiber matrix separation are the dominant mechanisms. These mechanisms also show dependence on physical parameters like fiber volume fraction and fiber orientation
Effect of flake distribution in mold on the flow during compression molding of unidirectional long fiber thermoplastic flakes
The growth of the use of composites in the industry generates a significant amount of composites waste. The thermoplastic wastes in the form of laminates and pre-pegs accounts for a significant percentage of the total material processed by composites manufacturing industries. These wastes could be shredded into smaller chips or flakes and compression molded into reusable products. Previous experiments have been carried out at the University of Twente in the Netherlands to produce an industrial product from recycled chopped woven flakes [1]. This paper discusses the compression molding process of chopped unidirectional (UD) flakes. The effect of consolidation pressure, dwell time and filling pattern of the mold on the laminates is studied. The paper shows the mechanisms of flake deformation generally observed during the molding process. Surface microscopy and density measurements show the extent of flake deformation and polymer flow. This qualitative analysis will later be used to model the process of flake deformation in melt to predict the mold filling behavior during compression molding of long (6-20 mm) thermoplastic flakes
Exploring stakeholders’ views on a corporatized zakat institution’s management performance
Charged jet cross section and fragmentation in proton-proton collisions at root S=7 TeV
We report the differential charged jet cross section and jet fragmentation distributions measured with the ALICE detector in proton-proton collisions at a center-of-mass energy s=7 TeV. Jets with pseudorapidity |\u3b7|<0.5 are reconstructed from charged particles using the anti-kT jet-finding algorithm with a resolution parameter R=0.4. The jet cross section is measured in the transverse momentum interval 5 64pTch jet<100 GeV/c. Jet fragmentation is studied measuring the scaled transverse momentum spectra of the charged constituents of jets in four intervals of jet transverse momentum between 5 and 30 GeV/c. The measurements are compared to calculations from the pythia model as well as next-to-leading-order perturbative QCD calculations with powheg+pythia8. The charged jet cross section is well described by powheg for the entire measured range of pTch jet. For pTch jet>40 GeV/c, the pythia calculations also agree with the measured charged jet cross section. pythia6 simulations describe the fragmentation distributions to 15%. Larger discrepancies are observed for pythia8
p-p, p-Lambda, and Lambda-Lambda correlations studied via femtoscopy in pp reactions at root s=7 TeV
We report on the first femtoscopic measurement of baryon pairs, such as p-p, p-\u39b, and \u39b-\u39b, measured by ALICE at the Large Hadron Collider (LHC) in proton-proton collisions at s=7TeV. This study demonstrates the feasibility of such measurements in pp collisions at ultrarelativistic energies. The femtoscopy method is employed to constrain the hyperon-nucleon and hyperon-hyperon interactions, which are still rather poorly understood. A new method to evaluate the influence of residual correlations induced by the decays of resonances and experimental impurities is hereby presented. The p-p, p-\u39b, and \u39b-\u39b correlation functions were fitted simultaneously with the help of a new tool developed specifically for the femtoscopy analysis in small colliding systems: Correlation Analysis Tool using the Schr\uf6dinger equation (CATS). Within the assumption that in pp collisions the three particle pairs originate from a common source, its radius is found to be equal to r0=1.125\ub10.018(stat)-0.035+0.058(syst) fm. The sensitivity of the measured p-\u39b correlation is tested against different scattering parameters, which are defined by the interaction among the two particles, but the statistics is not sufficient yet to discriminate among different models. The measurement of the \u39b-\u39b correlation function constrains the phase space spanned by the effective range and scattering length of the strong interaction. Discrepancies between the measured scattering parameters and the resulting correlation functions at LHC and RHIC energies are discussed in the context of various models
Neutral pion and η meson production in p–Pb collisions at √sNN = 5.02 TeV
Neutral pion and η meson invariant differential yields were measured in non-single diffractive p–Pb collisions at sNN = 5.02 TeV with the ALICE experiment at the CERN LHC. The analysis combines results from three complementary photon measurements, utilizing the PHOS and EMCal calorimeters and the Photon Conversion Method. The invariant differential yields of π0 and η meson inclusive production are measured near mid-rapidity in a broad transverse momentum range of 0.3&lt;pT&lt;20GeV/c and 0.7&lt;pT&lt;20GeV/c, respectively. The measured η/ π0 ratio increases with pT and saturates for pT &gt; 4 GeV / c at 0.483 ± 0. 015 stat± 0. 015 sys. A deviation from mT scaling is observed for pT&lt; 2 GeV / c. The measured η/ π0 ratio is consistent with previous measurements from proton-nucleus and pp collisions over the full pT range. The measured η/ π0 ratio at high pT also agrees within uncertainties with measurements from nucleus–nucleus collisions. The π0 and η yields in p–Pb relative to the scaled pp interpolated reference, RpPb, are presented for 0.3 &lt; pT&lt; 20 GeV / c and 0.7 &lt; pT&lt; 20 GeV / c, respectively. The results are compared with theoretical model calculations. The values of RpPb are consistent with unity for transverse momenta above 2 GeV / c. These results support the interpretation that the suppressed yield of neutral mesons measured in Pb–Pb collisions at LHC energies is due to parton energy loss in the hot QCD medium. © 2018, CERN for the benefit of the ALICE collaboration
Azimuthal Anisotropy of Heavy-Flavor Decay Electrons in p-Pb Collisions at root s(NN)=5.02 TeV
Angular correlations between heavy-flavor decay electrons and charged particles at midrapidity (|\u3b7|<0.8) are measured in p-Pb collisions at sNN=5.02 TeV. The analysis is carried out for the 0%-20% (high) and 60%-100% (low) multiplicity ranges. The jet contribution in the correlation distribution from high-multiplicity events is removed by subtracting the distribution from low-multiplicity events. An azimuthal modulation remains after removing the jet contribution, similar to previous observations in two-particle angular correlation measurements for light-flavor hadrons. A Fourier decomposition of the modulation results in a positive second-order coefficient (v2) for heavy-flavor decay electrons in the transverse momentum interval 1.5<4 GeV/c in high-multiplicity events, with a significance larger than 5\u3c3. The results are compared with those of charged particles at midrapidity and those of inclusive muons at forward rapidity. The v2 measurement of open heavy-flavor particles at midrapidity in small collision systems could provide crucial information to help interpret the anisotropies observed in such systems