921 resultados para TRANSFORMER AT DEEP SATURATION
Resumo:
During the building of a hydroelectrical power plant at Ilha Solteira in the Parana River (Brazil), materials of a highly weathered soil Oxisol were extracted from a depth between 5 and 8 m for engineering works. This resulted in an abandoned depression area. The topsoil was not salvaged and the open pit was not backfilled, and as result vegetation hardly or not at all recovered. on the residual saprolite materials, an experimental field was established to assess different soil rehabilitation treatments. Field experiments were initiated in 1992. After soil tillage, two different crops and three different liming strategies were compared, giving six combinations. In addition, two uncropped control treatments, tilled and no-tilled, were established so that a total of eight treatments were assessed. The experimental design consisted of four randomized experimental blocks, which included a total of 32 plots with a plot area of 100 m(2). This experiment was used to study the effectiveness of the soil-reclamation treatments after a 9-year period. Soil samples were taken at three different depths (0-10, 10-20, and 20-40 cm), and they were analyzed routinely for pH, organic-matter content, and cation exchange capacity (CEC). Revegetation of the abandoned saprolite material increased soil organic-matter content and cation exchange capacity (CEC), and to some extent small differences between treatments were evidenced. Exchangeable calcium (Ca) and magnesium (Mg) recovered faster than organic-matter content. A significant linear relationship was found between organic-matter content and CEC, suggesting continued addition of organic material will further approach the value of these parameters to those levels corresponding to natural soils under "Cerrado" vegetation.
Resumo:
OBJETIVO: Comparar a eficácia e segurança da profilaxia com heparina de baixo peso molecular (enoxaparina) versus heparina não fracionada (HNF). MÉTODOS: Setenta e cinco pacientes (59 homens e 16 mulheres ), submetidos a amputação maior dos membros inferiores (30 acima do joelho e 45 abaixo do joelho ), foram tratados ao acaso com HNF subcutânea (5,000 IU -2x/dia ) ou enoxaparina subcutânea (40mg/dia ) durante a hospitalização . A profilaxia teve início 12 horas antes da cirurgia ou , em casos emergenciais , no primeiro dia de pós-operatório. RESULTADOS: Os dois grupos de tratamento foram comparáveis em termos de características gerais . A avaliação da TVP foi feita por meio de exame clínico diário e pelo mapeamento dúplex antes e 5-8 dias após a cirurgia . A TVP foi documentada no lado operado em 9,75% dos pacientes tratados com enoxaparina e em 11,76% dos pacientes tratados com HNF (p=0,92) e houve um caso de TVP bilateral em cada grupo . Sangramentos não foram verificados nos 2 grupos . CONCLUSÃO: A enoxaparina e HNF foram igualmente eficientes e seguras para a profilaxia da TVP em pacientes submetidos à amputação de membros inferiores .
Resumo:
Aim. Superficial thrombophlebitis (ST) ascending the lower limbs is a common disease, which may be associated with deep vein thrombosis (DVT) and pulmonary embolism (PE). The aim of this study was to investigate the prevalence of DVT and PE as complications of ascending ST of the lower limbs in the great saphenous vein (GSV) or SSV (SSV) and probable risk factors.Methods. For this study 60 consecutive patients were enrolled with ascending ST of the GSV or SSV, seen between 2000 and 2003 at a public hospital in Botucatu, SP, Brazil. All patients were assessed clinically, by venous Duplex scanning of the lower limbs to confirm ST and test for DVT, and by means of pulmonary scintigraphy to test for PE.Results. In 13 ST cases (21.67%) there was concomitant DVT and 17 ST patients (28.33%) also had PE. Eleven patients had a clinical status suggestive of DVT, but only in eight of these (61.5%), this clinical diagnosis was confirmed. Fourteen patients had a clinical status suggestive of PE, and this diagnosis was confirmed in six cases (35.30%). ST patients who also had DVT and/or PE were given anticoagulant treatment with heparin and warfarin. None of the variables studied was predictive of DVT or PE (P>0.05). However, the presence of varicose veins reduced the risk of patients having DVT (relative risk=9.09; 95%CI:1.75 - 50.00 and P=0.023).Conclusion. The prevalence rates of PE (28.3%) and DVT (21.6%) were elevated in this sample of ascending ST cases, indicating a need for detailed assessment of patients for signs of these complications, including for therapeutic management decision making. [Int Angiol 2009;28:400-8]
Resumo:
Aim. This study aimed at assessing the accuracy of ultrasound (US) in the diagnosis of recent deep vein thrombosis (DVT) in an experimental study in dogs.Methods. Design: blinded and randomized experimental study. Twenty dogs were randomly divided in two groups: control group (CG) and thrombosis group (TG). US was performed in the pre- and postoperative period. Phlebography was performed immediately prior to the postoperative US. After the second US, a surgery was performed to detect whether thrombus was present or not. US results were compared to those of phlebography and surgical findings.Results. in all dogs, inferior vena cava (IVC) was compressible. The relations of IVC diameter with the aorta were higher (P<0.005) in TG than in CG. Spectral Doppler in spontaneous breathing, tissue harmonic imaging, power Doppler and B flow showed sensitivity, specificity and accuracy of 1. Phlebography presented sensitivity of 90%, specificity of 80% and accuracy of 85%, when compared to surgical finding.Conclusion. For the diagnosis of recent DVT in the experimental model used, venous compressibility proved to be inefficient. The ratio of WC diameter to aorta, when increased, suggests thrombosis. The use of new US technological advances increases accuracy. Phlebography was less accurate than US.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Objectives. To evaluate the response of the pulpo-dentin complex following application of a resin-modified glass-ionomer cement or an adhesive system in deep cavities performed in human teeth.Methods. Deep class V cavities were prepared on the buccal surface of 26 premolars. In Group I the cavity walls (dentin) and enamel were conditioned with 32% phosphoric acid and the dentin adhesive system One Step (Bisco, Inc., Itasca, IL, USA) was applied. In Groups 2 and 3, before total etching and application of bonding agent, the cavity floor was lined with the resin-modified glass-ionomer cement-Vitrebond (3M ESPE Dental Products Division, St. Paul, MN, USA) or the calcium hydroxide cement-Dycal (control group, Dentsply, Mildford, DE, USA), respectively. The cavities were restored using light-cured Z-100 composite resin (3M ESPE). The teeth were extracted between 5 and 30 days and prepared for microscopic assessment. Serial sections were stained with H/E, Masson's trichrome, and Brown and Brenn techniques.Results. In Group 1, the inflammatory response was more evident than in Groups 2 and 3. Diffusion of dental material components across dentinal tubules was observed only in Group 1, in which the intensity of the pulp response increased as the remaining dentin thickness decreased. Bacteria were evidenced in the lateral walls of two samples (Group 2) which exhibited no inflammatory response or tissue disorganization.Conclusions. Based on the experimental conditions, it was concluded total acid etching followed by application of One Step bonding agent cannot be recommended as adequate procedures. In this clinical condition the cavity walls should be lined with a biocompatible dental material, such as Vitrebond or Dycal. 2003 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
Resumo:
Objectives: To evaluate the pulpo-dentin complex response to a dentin adhesive application in deep cavities performed in human teeth.Methods: Deep class V cavities were prepared on the buccal surface of 46 premolars. The remaining dentin of the axial wall received 10% phosphoric acid and dentin adhesive (group DA), or was protected before the acid and dentin adhesive application with calcium hydroxide cement (group CH). Half of the teeth, which received the acid application directly over the axial wall, were contaminated prior to the procedures with dental plaque collected from the patient's own teeth (group DAC). The plaque was placed on the dentin for 5 min and then the cavity was washed. All teeth were restored with a light-cured composite resin. The teeth were extracted after 7, 30 or 60 days and prepared according to normal histologic techniques. Serial sections were stained with WE, Masson's trichrome and Brown & Brenn technique for demonstration of bacteria.Results: the histopathologic evaluation showed that in groups DA and DAC, the inflammatory response was more evident than in group CH. Also, the intensity of the pulp reaction increased as the remaining dentin thickness decreased. There was no statistical difference in the inflammatory response between the groups DA and DAC.Conclusion: Based on the experimental conditions, we concluded that the All Bond 2 adhesive system, when applied on dentin in deep cavities, showed an acceptable biocompatibility. However, the intensity of the pulpo-dentin complex response depends on the remaining dentin thickness. (C) 1999 Elsevier B.V. Ltd. All rights reserved.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Objectives. The aim of this in vivo study was to evaluate the human dental pulp response when a one-bottle adhesive system was applied on etched or unetched deep dentine.Methods. Eighteen class V deep cavity preparations were divided in three groups: group 1-total etching + two coats of single bond (SB) + composite resin (Z-100); group 2-enamel etching + two coats of SB + Z-100, group 3-cavity floor lined with a calcium hydroxide liner (Dycal) + acid-etching of enamel and lateral walls + two coats of SB + Z-100. Two teeth were used as intact control group. After 30 days the teeth were extracted and processed through H and E, Masson's trichrome and Brown and Brenn staining techniques.Results. Moderate inflammatory response, disorganization of pulp tissue, as well as, deposition of thin layer of reactionary dentin were observed in group 1 teeth in which the remaining dentin thickness (RDT) was less than 300 mum. These histological findings appear to be related to long resin tags formation and bonding agent diffusion through dentinal tubules. In group 2, slight inflammatory response was observed only in one tooth in which the RDT was 162 mum. In group 3, all the teeth showed normal histological characteristics which were similar to the intact control group. Presence of bacteria was not correlated with the intensity of pulpal response. The patients reported no symptoms during the experiment. Radiographic evaluation showed no periapical pathology for any of the teeth,Significance and conclusions. Acid-etched deep dentin (RDT less than 300 mum) lined with SB causes more intense pulpal response than unetched deep dentin. Based on the results observed in the present study and the conditions in which it was carried out, we recommend the application of a biocompatible liner before etching deep dentin and applying SB. (C) 2002 Academy of Dental Materials. Published by Elsevier B.V. Ltd. All rights reserved.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Nanocrystalline FeCuNbSiB alloys obtained from the partial crystallization of amorphous alloys have attracted technological attention due to their excellent magnetic properties, but the relationship between corrosion resistance and magnetic properties is not well established. The influence of Nb as an alloying element and effect of partial crystallization on the corrosion resistance of Fe73.5Si13.5B10Cu1, Fe73.5Si13.5B7Nb3Cu1 and Fe73.5Si13.5B5Nb5Cu1 amorphous alloys were studied and the effect of corrosion on magnetization saturation flux density, B-s, was investigated. The addition of niobium on amorphous alloys increases the corrosion resistance. The raise of Nb content from 3 to 5% increases the corrosion resistance also. A partial crystallization increases the corrosion resistance of the samples with Nb. However, in the samples without Nb, the partial crystallization diminishes the corrosion resistance. The values of B-s depend on the alloy corrosion resistance.) (C) 2002 Elsevier B.V. B.V. All rights reserved.
Resumo:
In the limit of small values of the aspect ratio parameter (or wave steepness) which measures the amplitude of a surface wave in units of its wave-length, a model equation is derived from the Euler system in infinite depth (deep water) without potential flow assumption. The resulting equation is shown to sustain periodic waves which on the one side tend to the proper linear limit at small amplitudes, on the other side possess a threshold amplitude where wave crest peaking is achieved. An explicit expression of the crest angle at wave breaking is found in terms of the wave velocity. By numerical simulations, stable soliton-like solutions (experiencing elastic interactions) propagate in a given velocities range on the edge of which they tend to the peakon solution. (c) 2005 Elsevier B.V. All rights reserved.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
In this paper, we examine the nonlinear control method based on the saturation phenomenon and of systems coupled with quadratic nonlinear ties applied to a shear-building portal plane frame foundation that supports an unbalanced direct cut-rent with limited power supply (non-ideal system). We analyze the equations of motion by using the method of averaging and numerical simulation. The interaction of the non-ideal structure with the saturation controller may lead to the occurrence of interesting phenomena during the forward passage through the several resonance states of the systems. Special attention is focused on passage through resonance when the non-ideal excitation frequency is near the portal frame natural frequency and when the non-ideal system frequency is approximately twice the controller frequency (two-to-one internal resonance).
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)