915 resultados para good point of view
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Nucleolus organizer regions (NORs) were analysed in two related and geographically close populations of Eigenmannia sp.1 (Pisces, Gymnotoidei, Sternopygidae) using silver staining and fluorescence in situ hybridization (FISH). The two populations differed in their AS-NOR phenotypes, displaying fixed differences in the NOR-bearing chromosome pairs. FISH with rDNA probes showed that these differences were due to the location of rDNA cistrons. This finding, showing fixed NOR differences between two populations belonging to the same species in a connected river system, is highly significant in terms of evolutionary change, possibly indicating an initial step of genetic differentiation. This result also has important implications from the cytosystematic point of view, as NORs usually have a very constant karyotypic location in fish species and have been used as species-specific chromosome markers.
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We support the idea that the baryon, B with mass MB, couples to its current with a coupling λ2 B ∼ 0.71 M6 B from an analysis of magnetic moment sum rules. And we find a sum rule among the experimental magnetic moments which is independent of the parameters of QCDSR. © 1998 Elsevier Science B.V. All rights reserved.
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Fatigue crack initiation occurs at the surface, although sub surface nucleation has also been reported. Localized imperfections like inclusions close to surface and surface small pits can result in crack sources. Coatings are not always beneficial by fatigue point of view too. Mechanical properties of the covering material can change considerably the fatigue behavior of base metal due to residual surface stresses, to micro cracks or to hydrogen embrittlement. This paper is concerned with analysis of electrolytic etch on the fatigue resistance of a 35NCD16 high strength steel in a mechanical condition of (1760 - 1960) MPa, and analysis of electroplated hard chromium effects on the fatigue resistance in a strength condition of 989 MPa. Hardness impression was used as a reference parameter in case of electrolytic etch. In both cases, experimental data showed that fatigue strength of 35NCD16 steel was considerably reduced. Copyright © 2001 Society of Automotive Engineers, Inc.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Natural scales determine the physics of quantum few-body systems with short-range interactions. Thus, the scaling limit is found when the ratio between the scattering length and the interaction range tends to infinity, while the ratio between the physical scales are kept fixed. From the formal point of view, the relation of the scaling limit and the renormalization aspects of a few-body model with a zero-range interaction, through the derivation of subtracted three-body T-matrix equations that are renormalization-group invariant.
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In this paper a hybrid solid oxide fuel cell (SOFC) system is analyzed. This system applies a combined cycle utilizing gas turbine associated to a SOFC for rational decentralized energy production. Initially the relative concepts about the fuel cell are presented, followed by some chemical and technical informations such as the change of Gibbs free energy in isothermal fuel oxidation (or combustion) directly into electricity. This represents a very high fraction of the lower heating value (LHV) of a hydrocarbon fuel. In the next step a methodology for the study of SOFC associated with a gas turbine system is developed, considering the electricity and steam production for a hospital, as regard to the Brazilian conditions. This methodology is applied to energetic analysis. Natural gas is considered as a fuel. In conclusion, it is shown by a Sankey Diagram that the hybrid SOFC system may be an excellent opportunity to strengthen the decentralized energy production in Brazil. It is necessary to consider that the cogeneration in this version also is a sensible alternative from the technical point of view, demanding special methods of design, equipment selection and mainly of the contractual deals associated to electricity and fuel supply.
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New materials, based on the well-known spinel compound NiMn 2O4, have been synthesized and characterized from the magnetic point of view. The manganese cation was partially substituted in the general formula NiMn2-xMexO4, by nonmagnetic and magnetic elements, such as Me = Ga, Zn, Ni and Cr (0 × 1). Prior to the determination of their magnetic properties, the non-substituted spinel NiMn2O4 was carefully characterized and studied as a function of the oxygen stoichiometry, based on the influence of the annealing atmosphere and quenching rate. The ferrimagnetic character was observed in all samples, with a paramagnetic-to-ferromagnetic transition temperature T c stabilized at 110 K, and well defined long-range antiferromagnetic interactions at lower temperatures, which depend on the applied field and the substitute concentration. © 2006 Sociedad Chilena de Química.
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Objective: To evaluate the health-related quality of life in children with functional defecation disorders. Methods: One hundred children seen consecutively were enrolled and subdivided into three subsets according to the Roma II classification criteria: functional constipation (n = 57), functional fecal retention (n = 29) and nonretentive functional soiling (n = 14). The generic instrument Child Health Questionnaire - Parent Form 50 (CHQ-PF50®), was used to measure quality of life and to assess the impact of these disorders from the point of view of parents. The instrument measures physical and psychosocial wellbeing in 15 health domains, each of which is graded on a scale from 0 to 100, with higher values indicating better health and greater wellbeing. Ten of these are then used to obtain two aggregated and summary scores: the physical and psychosocial scores. Results: No statistically significant differences were detected between subsets in terms of demographic or anthropometric characteristics. In 14 domains, children with defecation disorders scored lower than healthy children. When subsets were compared, statistically significant differences were detected between children with nonretentive functional soiling (lower scores) and those with functional constipation. Physical and psychosocial scores for the entire sample were lower than those for the group of healthy children used as controls. Conclusions: The CHQ-PF50® was considered adequate for demonstrating compromised quality of life in children with functional defecation disorders, as has been reported for other diseases, being a useful tool for making treatment decisions and for patient follow-up. Copyright © 2006 by Sociedade Brasileira de Pediatria.
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There is a growing body of evidence that melatonin and its oxidation product, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), have anti-inflammatory properties. From a nutritional point of view, the discovery of melatonin in plant tissues emphasizes the importance of its relationship with plant peroxidases. Here we found that the pH of the reaction mixture has a profound influence in the reaction rate and products distribution when melatonin is oxidized by the plant enzyme horseradish peroxidase. At pH 5.5, 1 mm of melatonin was almost completely oxidized within 2 min, whereas only about 3% was consumed at pH 7.4. However, the relative yield of AFMK was higher in physiological pH. Radical-mediated oxidation products, including 2-hydroxymelatonin, a dimer of 2-hydroxymelatonin and O-demethylated dimer of melatonin account for the fast consumption of melatonin at pH 5.5. The higher production of AFMK at pH 7.4 was explained by the involvement of compound III of peroxidases as evidenced by spectral studies. On the other hand, the fast oxidative degradation at pH 5.5 was explained by the classic peroxidase cycle. © 2007 The Authors.
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The rise in boiling point of grapefruit juice was experimentally measured at soluble solids concentrations in the range of 9.3-60.6 °Brix and pressures between °6.0 × 103 and 9.0 × 104 Pa. Different approaches to represent experimental data, including the Dhring's rule, the Antoine equation and empirical models proposed in the literature were tested. In the range of 9.3-29.0 °Brix, the rise in boiling point was nearly independent of pressure, varying only with juice concentration. Considerable deviations of this behavior began to occur at concentrations higher than 29.0 °Brix. Experimental data could be best predicted by adjusting an empirical model, which consisted of a single equation that takes into account the dependence of rise in boiling point on pressure and concentration. © SAGE Publications 2007.
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In the presence of a cosmological constant, ordinary Poincaré special relativity is no longer valid and must be replaced by a de Sitter special relativity, in which Minkowski space is replaced by a de Sitter spacetime. In consequence, the ordinary notions of energy and momentum change, and will satisfy a different kinematic relation. Such a theory is a different kind of a doubly special relativity. Since the only difference between the Poincaré and the de Sitter groups is the replacement of translations by certain linear combinations of translations and proper conformal transformations, the net result of this change is ultimately the breakdown of ordinary translational invariance. From the experimental point of view, therefore, a de Sitter special relativity might be probed by looking for possible violations of translational invariance. If we assume the existence of a connection between the energy scale of an experiment and the local value of the cosmological constant, there would be changes in the kinematics of massive particles which could hopefully be detected in high-energy experiments. Furthermore, due to the presence of a horizon, the usual causal structure of spacetime would be significantly modified at the Planck scale. © 2007 American Institute of Physics.
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Cytogenetic and random amplified polymorphic DNA analyses carried out in the species Leptodactylus podicipinus, L. ocellatus, L. labyrinthicus, and L. fuscus from rural and urban habitats of the northwest region of São Paulo State, Brazil, showed that the karyotypes (2n = 22), constitutive heterochromatin distribution and nucleolus organizer region (NOR) location did not differ between the populations from the two environments. The in situ hybridization with an rDNA probe confirmed the location of the NORs on chromosome 8 revealing an in tandem duplication of that region in one of the chromosomes of L. fuscus. DAPI showed that part of the C-band-positive heterochromatin is rich in AT, including that in the proximity the NORs in L. podicipinus and L. ocellatus. The molecular analyses showed that the two populations (urban and rural) of L. podicipinus and L. fuscus are similar from a genetic point of view. The urban and rural populations of species L. ocellatus and L. labyrinthicus showed differences in genetic structures, probably due to urbanization which interferes with the dispersion of those frogs. The marked differences observed between the two populations of L. ocellatus can be representing the cryptic condition of the species. Unweighted pair-group method of analysis and genetic distance analysis detected the genetic proximity between L. ocellatus and L. fuscus. The results indicate that there was no reduction in the genetic diversity in the populations from the urban environment; however, the survival of these frogs would not be guaranteed in the case of an increase in human impact especially for populations of L. labyrinthicus and L. ocellatus. ©FUNPEC-RP.
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Includes bibliography
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This work introduces an innovative urinal for public convenience, that promotes at the same time water reuse and personal higiene, in a safe and economical way . Furthermore it demonstrates the latest technology and its technical and economical viabillity of utilization in new and already existing buildings facilities. This new model of personal higiene equipment offers as main benefits the improved economy with subsequent decrease in drinkable water consumption, sanitary safety, low cost and easy installation due to its simplicity and to the fact that it can be installed in already existing facilities. The proposal is constituted by a higienic, ecological and smart system for flushing of public urinals. It is a conjugated system of lavatory and urinal that reuses hands higienization water from the lavatory for flushing purpose. The proposed urinal can be operated manually or automatically by means of a presential sensor. The system promotes drinkable water economy by a rational utilization by avoiding the use of waste water from hand washing in place of clean water for flushing. The proposed equipment increases the economy of clean water in a simple and economical way and it can be installed in any type of public lavatory facilitie such as schools, public buildings, hospitals, commercial buildings, bus terminals, airports, stadiums, parking buildings and shopping centers. Additional benefits of the proposed system is the suggestion of hands washing before and after the use of the urinal without contamination risks from focet handling.and render more attractive the installation for a rational use of clean water in commercial and industrial buildings. Pay-back has shown to be very attractive for a number of internal return rates and also very attractive from the point of view of environmental protection.
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Includes bibliography