138 resultados para 403
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The effect of bath composition and electroplating conditions on structure, morphology and composition of amorphous Fe-Cr-P-Ni-C deposits on Cu substrate was investigated. The deposition efficiency of Fe-Ni-P-C alloy increased significantly with the addition of formic acid, but decreased with the addition of Cr to the plating bath. The increase of charge density activates the inclusion of Cr in the deposit. However, above a specific value of charge density, which depends on deposition current density, the Cr content in the deposit decreases. SEM analysis showed that the increase of Ni, Cr or charge deposition promotes susceptibility to microcracking.
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During the study of Heliotropium L. genus in the project Flora Fanerogâmica do Estado de São Paulo, it was verified that Heliotropium fruticosum L. presents a new geographical occurrence in Southeast of Brazil. Description, illustration and comments about relationships, distribution and phenology, as well as a summary of examined material are included in this paper.
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We evaluated morphological and cytogenetic data for three animals similar to the species of deer previously described as the Small Red Brocket (Mazama bororo Duarte, 1996). We compared these animals with five M. americana, five M. nana and three hybrids between M. americana and M. nana. The M. bororo chromosomes can be standardized as follows : 8 group A chromosomes (large bi-armed) ; 2 group C chromosomes (small bi-armed) ; 4 group D chromosomes (large acrocentric) ; and 18 group E chromosomes (small acrocentric). There were great differences between this karyotype and those of M. nana and M. americana. With respect to external morphology, the animals in the present study had some similarities to M. americana and M. nana and great similarities with their hybrids. Most of the body measurements of M. bororo were significantly different from those of M. americana and M. nana, but similar to those of the hybrids. Mazama bororo is distributed in the last remnants of the Atlantic forest, extending from the southeastern part of the State of São Paulo to the northeastern part of the State of Paraná, Brazil. The rapid destruction of the Atlantic Forest requires urgent conservation measures for the species.
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For light exotic nuclei modeled as two neutrons n and a core A, we report results for the two-neutron correlation functions and also for the mean-square radii, considering a universal scaling function. The results of our calculations for the neutron-neutron correlation functions are qualitatively consistent with recent data obtained for 11Li and 14Be nuclei. The root-mean-square distance in the halo of such nuclei are also consistent with data, which means that the neutrons of the halo have a large probability to be found outside the interaction range. Therefore the low-energy properties of these halo neutrons are, to a large extend, model independent as long as few physical input scales are fixed. The model is restricted to s-wave subsystems, with small energies for the bound or virtual states. For the radii we are also shown results for the 6He and 20C. All the interaction effects, as higher partial wave in the interaction and/or Pauli blocking effect are, to some extend, included in our model, as long as the three-body binding energy is supplied. © 2005 American Institute of Physics.
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Composites made of calcium modified lead titanate ceramic powder and poly (ether-ether-ketone) high performance polymer matrix were prepared in the film form using a hot press. The acoustic and electromechanical properties of the composites have been determined using the ultrasonic immersion technique and piezoelectric spectroscopy, respectively. The composite film with 60 - 40 vol.% PTCa/PEEK was tested as acoustic emission detector. Preliminary results shown that the piezo composite can be used as sensor to evaluate the behavior of materials.
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Tuberculosis (TB) is a serious public health problem all over the world, which was recognized by the WHO in 1993 as a global emergency because of its very high incidence in the 22 countries that concentrate 80% of TB cases. One of these countries is Brazil, where TB occurrences are well-documented in major cities, but little is known of its spread in rural areas and small towns. Therefore, an epidemiological study was done on medical records of TB sufferers in the rural district and small town of Américo Brasiliense, São Paulo state, from 1992 to 2002, with the aim of improving TB prevention and treatment. The results showed that the incidence of TB peaked in the years of intense migration of rural workers, largely cane-cutters. Among these, the disease attacks mainly the men, in their productive years (20 to 40 years old). The predominant clinical form observed was pulmonary tuberculosis. The treatment abandonment rate was less than 1.8%, while the cure rate was around 90%. The disease detection rate by examination of sputum for acid-fast bacilli was around 60%.
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Purpose: to compare in a retrospective way, 51 women who underwent tubal ligation, 30 through microlaparoascopy (Gmicrol) and 21 through minilaparotomy (Gminil). Methods: the analyzed parameters were: total time for accomplishment of the procedure and the surgical technique, time of hospital stay and return to the habitual activities after the surgery, postoperative pain, morbidity, satisfaction degree and esthetic effect, considering values of p<0,05 as significant, and also standard cost. Results: Gmicrol took less time to accomplish the surgery than the Gminil (43 against 57 minutes respectively, p<0,05), less time to accomplish the surgical technique (6.48 against 30.32 minutes respectively, p<0,05), and lower hospital stay (9,90 hours as against 41,7 hours respectively, p <0,05). There was no significant difference between the two groups regarding time to return to the habitual activities after surgery. To evaluate postoperative pain, a scale of 0-10 it was applied. Gmicrol present a lower pain score on the 1st and 2nd postoperative days (1.13 and 0.26 to Gmicrol and 4.52 and 1.14 to Gminil, respectively, p<0,05). There was no significant difference between immediate postoperative the most common complaint being pain at the site of pain and that on the 3rd postoperative day. Gminil presented a higher morbidity rate incision. To evaluate the satisfaction degree and esthetic effect, numeric values were attributed to as good, regular, poor and very bad as answered by the patiets. Gmicrol presented a higher satisfaction degree (p<0,05) and better esthetic effect as compared to Gminil (p <0,05). The microlaparoscopy standard cost was R$ 109.30 being lower than that of minilaparotomy. Conclusions: tubal ligation by microlaparoscopy, under local anesthesia and conscious sedation presented some advantages compared to minilaparotomy.
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Several studies suggest that, on a large scale, relief conditions influence the Atlantic Forest cover. The aim of this work was to explore these relationships on a local scale, in Caucaia do Alto, on the Ibiúna Plateau. Within an area of about 78 km2, the distribution of forest cover, divided into two successional stages, was associated with relief attribute data (slope, slope orientation and altitude). The mapping of the vegetation was based on the interpretation of stereoscopic pairs of aerial photographs, from April 2000, on a scale of 1:10,000, while the relief attributes were obtained by geoprocessing from digitalized topographic maps on a scale of 1:10,000. Statistical analyses, based on qui-square tests, revealed that there was a more extensive forest cover, irrespective of the successional stage, in steeper areas (>10 degrees) located at higher altitudes (>923 m), but no influence of the slope orientation. There was no sign of direct influence of relief on the forest cover through environmental gradients that might have contributed to the forest regeneration. Likewise, there was no evidence that these results could have been influenced by the distance from roads or urban areas or with respect to permanent preservation areas. Relief seems to influence the forest cover indirectly, since agricultural land use is preferably made in flatter and lower areas. These results suggest a general distribution pattern of the forest remnants, independent of the scale of study, on which relief indirectly has a strong influence, since it determines human occupation.
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The effect of an organic acid mixture (OA) and a Lactobacillus-based probiotic culture on Salmonella enteritidis (SE) infection in broiler chicks was evaluated. In exp. 1, chicks were challenged by oral gavage with SE, held in chick boxes for 2 h and randomly assigned to either untreated control or continuous OA treatment in the drinking water. Crop and cecal tonsils were cultured at 48 h and 5 d post-challenge for recovery of SE. Recovery of SE in the crop and cecal tonsils at 48 h was significantly (p<0.05) lower in the OA treated group as compared to control chickens but not different at 5d. In exps.2 and 3, chicks were SE challenged, held in chick boxes for 2 h and randomly assigned to either untreated control, probiotic, OA, or probiotic+OA. After 24 or 48 h, crop and cecal tonsils were cultured for the presence or absence of SE. After 24 h, probiotic or probiotic+OA significantly reduced SE recovery from the crop as compared to controls. All treatments reduced SE recovery from the cecal tonsils at 24 h. While no significant differences were observed in SE recovery from crop at 48 h, SE recovery from probiotic and or probiotic+OA groups was significantly lower than the controls in the cecal tonsils. These data suggest that combination treatment with the selected OA and Lactobacillus-based probiotic culture is more effective than individual treatment for Salmonella reduction in chicks. © Asian Network for Scientific Information, 2007.
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Nowadays, power system operation becomes more complex because of the critical operating conditions resulting from the requirements of a market-driven operation. In this context, efficient methods for optimisation of power system operation and planning become critical to satisfy the operational (technical), financial and economic demands. Therefore, the detailed analysis of modern optimisation techniques as well as their application to the power system problems represent a relevant issue from the scientific and technological points of view. This paper presents a brief overview of the developments on modern mathematical optimisation methods applied to power system operation and planning. Copyright © 2007 Inderscience Enterprises Ltd.
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In this work the interaction of the pesticide carbaryl with two groups of biomimetic ligands, peptides and MIPs was screened by multiple minima hypersurfaces (MMH) procedures, through the AM1 semiempirical method. Data related to the properties of the molecular association of the complex biomimetic ligand-pesticide were obtained and compared with another molecular modeling algorithm named Leapfrog, as included in the Sybyl software package, and experimental results from the literature, remarking good correlation between them. All important MMH program parameters (cells number, box size, conformers) were studied and optimized with the aim of getting the minimum computation time without losing the correlation with experimental data. The data demonstrated that MMH approach can be used as a fast biomimetic ligand screening tool for MIPs. In the case of peptides the computation time was not comparable with the molecular dynamics methods conventionally used for this approach. © 2011 Springer Science+Business Media B.V.
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This work proposes a new three-phase multipulse rectifier based on the delta autotransformer connection with DC-DC Boost stages and constant hysteresis control which has the objective of providing a reliable DC bus for on-board applications, electric motor drives and similars, always considering power quality issues. Thus, the proposal presents 0.99 power factor, 6% harmonic distortions in the currents from the mains and enhanced magnetic core utilization, which results in low weight and volume for the overall converter. The proposed control technique uses the simple constant hysteresis concept, thus leading to a low-cost but effective and reliable strategy. © 2011 IEEE.
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Molecular recognition events are key issues in many biological processes. STD NMR (saturation transfer difference nuclear magnetic resonance spectroscopy) is one of the techniques used to understand such biological interactions. Herein, we have investigated the interactions of four β-lactam antibiotics belonging to two classes (cephalosporins and penicillins) with human serum albumin (HSA) by 1H STD NMR revealing that the interaction between the aromatic moiety and HSA is responsible for the binding efficiency. Thus, the structural differences from the five to six-membered thio ring in penicillins and cephalosporins do not seem to influence antibiotic-albumin interactions. © 2012 Sociedade Brasileira de Química.
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The coronary sinusin fetuses ofzebu-crossedbovinesis studiedbyvasculardissectionsand radiographs. There aretwopredominant patterns offormation of thecoronary sinus: bydirect continuation of theleft azygos vein, from thegreat cardiac vein, and by theunion of thegreat cardiac veinwith theleft azygos vein. The first patternappeared in17animals,while thesecondpatternformation of thecoronary sinuswas found in13animals. Regarding sex there was nodifference between thepatterns shown.The main tributariesof the coronaryveinincattleare representedby the followingvessels: great cardiac vein, middle cardiac vein, veins of the faceof theleft ventricle andatrium, obliqueveinof left atrium.The great cardiac veinisseen asadirect continuation of theinterventricular veinparaconal. From these results, it appears thatthe standardvenousfetalbovineheartis predominantlyconfluentthe coronary sinus. Onlyasmall number ofvesselsare directlyconfluentto theright atrium ofbovine heart.
Correspondence between the self-dual model and the topologically massive electrodynamics: A new view
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Following the study of the Topologically Massive Theories under the Hamilton-Jacobi, we now analyze the constraint structure of the Self-Dual model as well as its correspondence with the Topologically Massive Electrodynamics. © 2013 American Institute of Physics.