74 resultados para irregularities waived


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This study compared the effect of physicochemical surface conditioning methods on the adhesion of bis-GMA-based resin cement to particulate filler composite (PFC) used for indirect dental restorations. PFC blocks (N (block)=54, n (block)=9 per group) were polymerized and randomly subjected to one of the following surface conditioning methods: a) No conditioning (Control-C), b) Hydrofluoric acid (HF)etching for 60s (AE60), c) HF for 90s (AE90), d) HF for 120s (AE120), e) HF for 180s (AE180), and f) air-abrasion with 30 mu m silica-coated alumina particles (AB). The conditioned surfaces were silanized with an MPS silane, and an adhesive resin was applied. Resin composite blocks were bonded to PFC using resin cement and photo-polymerized. PFC-cement-resin composite blocks were cut under coolant water to obtain bar specimens (1mmx0.8mm). Microtensile bond strength test (mu TBS)was performed in a universal testing machine (1mm/min). After debonding, failure modes were classified using stereomicroscopy. Surface characterization was performed on a set of separate specimen surfaces using Scanning Electron Microscopy (SEM), X-Ray Dispersive Spectroscopy (XDS), X-Ray Photoelectron Spectroscopy (XPS), and Fourier Transform-Raman Spectroscopy (FT-RS). Mean mu TBS (MPa) of C (35.6 +/- 4.9) was significantly lower than those of other groups (40.2 +/- 5.6-47.4 +/- 6.1) (p<0.05). The highest mu TBS was obtained in Group AB (47.4 +/- 6.1). Prolonged duration of HF etching increased the results (AE180: 41.9 +/- 7), but was not significantly different than that of AB (p>0.05). Failure types were predominantly cohesive in PFC (34 out of 54) followed by cohesive failure in the cement (16 out of 54). Degree of conversion (DC) of the PFC was 63 +/- 10%. SEM analysis showed increased irregularities on PFC surfaces with the increased etching time. Chemical surface analyses with XPS and FT-RS indicated 11-70% silane on the PFC surfaces that contributed to improved bond strength compared to Group C that presented 5% silane, which seemed to be a threshold. Group AB displayed 83% SiO2 and 17% silane on the surfaces.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The goal of this paper is to analyze the influence of the intense geomagnetic storms in the ionosphere and GNSS (GPS) positioning. It was analyzed the effects of intense geomagnetic storm of November 20th 2003 using GPS data from RBMC (Brazilian Network for Continuous Monitoring) located in different sites in the Brazilian region and ionosphere global maps. While analyzing the results, it can be observed an increase in the electron density of the ionosphere in the regions near to the geomagnetic equator in the afternoon on the day of the storm. In the period after the sunset of the storm day, there is an increase in the density of free electrons and ionospheric irregularities in regions furthest from the geomagnetic equator, when compared to geomagnetically quiet days. When the positioning point is analyzed, it is observed high discrepancies values in planimetry and altimetry at the same position for periods of changes that occurred in the ionosphere, especially for the GPS stations located furthest from the geomagnetic equator in the period after the sunset Sun.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Scintillations are rapid fluctuations in the phase and amplitude of transionospheric radio signals which are caused by small-scale plasma density irregularities in the ionosphere. In the case of the Global Navigation Satellite System (GNSS) receivers, scintillation can cause cycle slips, degrade the positioning accuracy and, when severe enough, can even lead to a complete loss of signal lock. Thus, the required levels of availability, accuracy, integrity and reliability for the GNSS applications may not be met during scintillation occurrence; this poses a major threat to a large number of modern-day GNSS-based applications. The whole of Latin America, Brazil in particular, is located in one of the regions most affected by scintillations. These effects will be exacerbated during solar maxima, the next predicted for 2013. This paper presents initial results from a research work aimed to tackle ionospheric scintillation effects for GNSS users in Latin America. This research is a part of the CIGALA (Concept for Ionospheric Scintillation Mitigation for Professional GNSS in Latin America) project, co-funded by the EC Seventh Framework Program and supervised by the GNSS Supervisory Authority (GSA), which aims to develop and test ionospheric scintillation countermeasures to be implemented in multi-frequency, multi-constellation GNSS receivers.

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Infections Related to Healthcare (IRAS) is a problem of worldwide concern, responsible for much morbidity and lethality. The incidence of IRAS associated with resistant microorganisms has increased worldwide. It is also known that the etiology of bacterial resistance is multifactorial, thus controlling the spread of resistant microorganisms requires the implementation of control measures that involve the performance of standard and contact precautions, plus the use of antimicrobials. To diagnose the problem as to the likely accession of the measures of infection control was prepared in a form to inspect the practices of the health staff acting with patients in contact precautions. The inspections had an educational and awareness, no punitive measures were taken to staff as warnings, suspensions or complains of a breach of ethics. If any irregularities were found, the professional standards of care countershaft contact and the nurse responsible for the head nurse or unit area were notified and counseled about the correct practice of isolation. While an undergraduate student initiated precautionary inspections of contact in order to verify the actual use of isolation measures, since the professionals were unaware of my active participation in the Committee on Infection Control. Facilities and difficulties were encountered in the process, and from the inspections was possible interventions to facilitate compliance with standards for isolation imposed by contact. Since the instrument has significantly improved adherence to contact isolation practices, the members of the Infection Control regulated inspections and intend to use it as a permanent method

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Currently, there has been a growing concern for men and women with the appearance of the face and body, driven primarily by aesthetic standards set by the media. For this, the pharmaceutical and cosmetic industries have conducted numerous research projects aiming at the development of formulations that mitigate the aging and some skin disorders such as hipercromies. One of the most frequent pathologies of skin is melasma, a manifestation of hyperpigmentation caused by hipermelanogenesis symmetrical and progressive, caused usually by hormonal irregularities, exposure to sunlight and genetic factors. In addition to sunscreen, the treatment is indicated the use of depigmenting substances, among them the kojic dipalmitate (DK), which is cleaved into kojic acid (5- hydroxy-2-hydroxy-methyl-4H-piran-4-one) by esterase after absorption by the skin cells. The kojic acid inhibits the action of tyrosinase as a chelator of ions and promotes the reduction of eumelanin and its precursor monomer. To promote a controlled release and improve the stability of the system, the DK can be incorporated into multiple emulsions, that is, complex systems composed of two emulsifications, where the two types of emulsions (W/O and O/W or O/W and W/O) exist simultaneously, forming emulsions of type W/O/W or O/W/O. This work aimed to incorporate the DK in emulsion W/O/W, physical-chemical systems obtained and to evaluate the antioxidant and depigmenting action in vitro of the developed formulations. The physico-chemical characterization was performed by microscopic analysis, quantification and size distribution, determination of pH, conductivity, zeta potential and bioadhesive test of the formulations. The droplet size in accordance with the use of light microscopy and dynamic light scattering is approximately 1μm. The pH, electrical conductivity and bioadhesion have not changed with the addition... (Complete abstract click electronic access below)

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In this work, it was studied the thermal and fluid dynamic behavior from theorical and experimental point of view of a blast furnace tuyere. The tuyere is responsible for the hot air insuflation into the blast furnace. The parameter used in the comparison was the difference between the cooling water inlet and outlet temperatures. There were used forced convection correlations inside circular sections with adequations for non circular sections. Based on operations dates of flux and thermal loads it was possible to model numerically the tuyere, and, since it was obtained the wall temperatures, estimate the conduction and convection resistances and the heat flux through the walls in contact with the water. The total heat fluxes from wall to water were applied to the energy conservation equation where could be estimated the theorical temperature variation. Compared to the real value, the theorical value presented a difference of 0,2 °C. Considering that the boundary conditions around the tuyere are transitories and that your channels have some rugosity irregularities we can consider the estimation method for cooling system coherent with the real operational parameters

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In the process of artificial incubation of fertile eggs of chicken (Gallus gallus domesticus) there are procedures that, they are not hindered the birth, they cause embryonic mortality. Handlings before incubation as disinfection and storage are capable to reduce the embryonic if accomplished of inadequate way viability. Already in the incubation process properly says, irregularities in variables as temperature, turning, humidity and ventilation in the incubator reduce the hatchability, what means that, of the total of fertile eggs there is reduction in the number of born chicks, there is like this the reduction of profit of the incubator, being necessary an analysis of which they interfered in the birth

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Any failure process that may occur in a part probably is located where the stress exceeded the level of resistance. When a part or component has a sharp change in geometry, such as slots, holes, grooves, bumps or other irregularities, there is an increased concentration of stress at a specific location of the part. The objective of this study is to determine the maximum stresses in structural parts and components using the equations of elasticity theory in conjunction with the stress concentration factor experiment and compare them with results obtained by finite element method

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Pós-graduação em Ciências Cartográficas - FCT

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)