Estudo das características morfológicas dos pites nos materiais resistentes à corrosão

This paper has as a purpose a new alternative technique development to characterize pitting corrosion evolution, aiming classification, size and determination of morphological parameters which rule pits increase. In this case, the method will be applied to the 304 ABNT stainless steel, thermally treated and exposed to different times in salt spray. Different 304 steel conditions, rolled and thermally treated have exhibited similar geometry, predominantly conic, near-conic and irregular pits. On rolled steel, pits width increases faster than height; however, on thermally treated steel, pits are found to increase in height.

Conceptual model for adaptable and extensible visual data exploration

Interactive visual representations complement traditional statistical and machine learning techniques for data analysis, allowing users to play a more active role in a knowledge discovery process and making the whole process more understandable. Though visual representations are applicable to several stages of the knowledge discovery process, a common use of visualization is in the initial stages to explore and organize a sometimes unknown and complex data set. In this context, the integrated and coordinated - that is, user actions should be capable of affecting multiple visualizations when desired - use of multiple graphical representations allows data to be observed from several perspectives and offers richer information than isolated representations. In this paper we propose an underlying model for an extensible and adaptable environment that allows independently developed visualization components to be gradually integrated into a user configured knowledge discovery application. Because a major requirement when using multiple visual techniques is the ability to link amongst them, so that user actions executed on a representation propagate to others if desired, the model also allows runtime configuration of coordinated user actions over different visual representations. We illustrate how this environment is being used to assist data exploration and organization in a climate classification problem.

Estudo biológico e morfométrico dos estádios ninfais de Rhodnius neglectus Lent, 1954 (Hemiptera, Reduviidae)

The following parameters of the biological cycle of the Rhodnius neglectus were determined under a temperature of 28°C and relative humidity of the air varying between 52-94%: a) average period of incubation: 13.67 days; b) rate of the eggs eclosion: 86.18%; c) average period of growth of the 1st, 2nd, 3rd, 4th, 5th instar nymphs: 18.91, 15.19, 21.38, 21.34, 30.43 days, respectively; d) percentage of death in the instar nymphs: 13.82, 18.26, 9.95, 8.78, 15.06% respectively; e) percentage of changes per instar nymphs: 86.18, 81.74, 90.05, 91.22, 84.94% respectively. The morphometric study with the stereoscopic microscope and Leica image analyses system, using the Qwin software, of the five instar nymphs showed that in the five instar nymphs a gradual growth of the head, thorax and abdomen occurs. In all the instars the abdomen is the largest segment. In the four first instars the head is larger than the thorax. In the fifth instar the head and the thorax present equivalent sizes.

Detecção de pistas de aeroporto em imagens orbitais utilizando morfologia matemática

The Brazilian Cartography presents great deficiency in cartographic products updating. This form, Remote Sensins techniques together Digital Processing Images - DPI, are contributing to improve this problem. The Mathematical Morphology theory was used in this work. The principal function was the pruning operator. With its were extracted the interest features that can be used in cartographic process updating. The obtained results are positives and showed the use potential of mathematical morphology theory in cartography, mainly in updating.

β-carotene attenuates the paradoxical effect of tobacco smoke on the mortality of rats after experimental myocardial infarction

The objective of this study was to investigate the effects of exposure to tobacco smoke (ETS) in rats that were or were not supplemented with dietary β-carotene (BC), on ventricular remodeling and survival after myocardial infarction (Ml). Rats (n = 189) were allocated to 4 groups: the control group, n = 45; group BC administered 500 mg/kg diet, n = 49, BC supplemented rats; group ETS, n - 55, rats exposed to tobacco smoke; and group BC+ETS, n = 40. Wistar rats weighing 10O g were administered one of the treatments until they weighed 200 to 250 g (∼5 wk). The ETS rats were exposed to cigarette smoke for 30 min 4 times/d, in a chamber connected to a smoking device. After reaching a weight of 200-250 g, rats were subjected to experimental MI (coronary artery occlusion) and mortality rates were determined over the next 105 d. In addition, echocardiographic, isolated heart, morphometrical, and biochemical studies were performed. Mortality data were tested using Kaplan-Meyer curves and other data by 2-way ANOVA. Survival rates were greater in the ETS group (58.2%) than in the control (33.3%) (P = 0.001) and BC+ETS rats (30.0%) (P = 0.007). The groups did not differ in the other comparisons. Left ventricular end-diastolic diameter normalized to body weight was greater and maximal systolic pressures were lower in the ETS groups than in non-ETS groups. Previous exposure to tobacco smoke induced a process of cardiac remodeling after MI. There is a paradoxical protector effect with tobacco smoke exposure, characterized by lower mortality, which is offset by BC supplementation. © 2005 American Society for Nutritional Sciences.

Influence of chromate, molybdate and tungstate on pit formation in chloride medium

It has been characterized and evaluated the 2024-T351 and 7050-T7451 aluminum alloys pitting corrosion in naturally aerated chloride aqueous solutions containing chromate, molybdate and tungstate. It has been carried out electrochemical and non-electrochemical immersion corrosion tests accompanied by surface metallography analysis using an optical microscopy. Chromate for the two alloys and in molybdate for 7050 has corrosion inhibiting effects, whereas tungstate promotes the pitting corrosion for these alloys. Quantitative surface analysis upon the alloys after immersion has indicated that pits are predominantly conical or quasi-conical and irregular. In general, pits have been wider than deep and the widest have been also the deepest. Despite inhibitor presence, when pits have been nucleated, they grow with the same intensity. © 2005 Elsevier B.V. All rights reserved.

A comparison of human and porcine acellular dermal tissues in the subcutaneous space of a rat model

The study compared the host response to a human and a porcine acellular dermal tissue implanted in the subcutaneous space of a rat model. The human and porcine acellular grafts were surgically implanted in the subcutaneous tissue of rats (5 rats/group) and the materials were evaluated at 7, 15, 30, 60 and 180 postoperative days (PO). The histological immune response was quantified using a digital image analysis system, which evaluated the number of vessels present in the implants and in the surrounding soft tissue, the area of inflammatory cell infiltration in the grafts, the width of the capsular formation present around the tissues and the area of implants absorbed. The data were submitted to statistical analysis. Light microscopy showed mononuclear cellular infiltration, the presence of a capsular formation surrounding the grafts and the presence of vacuolar structures (optically empty spaces) inside the implants. The image analysis comparing both materials showed significant inflammatory cells in the human graft at 15 and 30 PO, thicker capsular formation in the porcine tissue at 60 PO, increased number of vessels inside the implants and in the surrounding tissues in the porcine graft and a similar absorption pattern in both materials at 180 PO. The histological findings showed that both tissues were well-tolerated when implanted in the subcutaneous tissue of rats, allowing us to consider the porcine acellular dermal graft as a provisional alternative material for reconstructive plastic surgery. Copyright © 2005 Taylor & Francis LLC.

Recycling of silicon carbide and corn starch as binder originating from commercial starch consolidation

The main goal of this work is to demonstrate that the use of recycled material originated from SiC ceramics is viable. These ceramics were produced by commercial starch consolidation process. Before calcination stage, surplus of these materials always appears. This surplus is rich in SiC and starch. Samples were made by material previously milled in automatic mortar and sieved (100 Tyler). Later, 10% of distilled water was added to the material and the mixture was pressed at 40 MPa. In order to characterize the ceramic, three point flexural test were made, according to the ASTM C1161/94 norm. The results were analyzed by Weibull statistical method. Apparent density and porosity measures also were made, according to ASTM C20/87 norm. A verification of the surface was made in the fracture area by the depth from focus method and SEM image analysis. The results showed that the recycling process is fully viable, being a good economic option and reduce possible pollutant effect to the environment.

Autogenous bone graft with or without a calcium sulfate barrier in the treatment of class II furcation defects: A histologic and histometric study in dogs

Background: The purpose of this study was to histologically evaluate the healing of surgically created Class II furcation defects treated using an autogenous bone (AB) graft with or without a calcium sulfate (CS) barrier. Methods: The second, third, and fourth mandibular premolars (P2, P3, and P4) of six mongrel dogs were used in this study. Class II furcation defects (5 mm in height × 2 mm in depth) were surgically created and immediately treated. Teeth were randomly divided into three groups: group C (control), in which the defect was filled with blood clot; group AB, in which the defect was filled with AB graft; and group AB/CS, in which the defect was filled with AB graft and covered by a CS barrier. Elaps were repositioned to cover all defects. The animals were euthanized 90 days post-surgery. Mesio-distal serial sections were obtained and stained with either hematoxylin and eosin or Masson's trichrome. Histometric, using image-analysis software, and histologic analyses were performed. Linear and area measurements of periodontal healing were evaluated and calculated as a percentage of the original defect. Percentage data were transformed into arccosine for statistical analysis (analysis of variance; P<0.05). Results: Periodontal regeneration in the three groups was similar. Regeneration of bone and connective tissue in the furcation defects was incomplete in most of the specimens. Statistically significant differences were not found in any of the evaluated parameters among the groups. Conclusion: Periodontal healing was similar using surgical debridement alone, AB graft, or AB graft with a CS barrier in the treatment of Class II furcation defects.

Orientação semi-automática de imagens CBERS usando rodovias como controle de campo

In this paper is proposed a methodology for semiautomatic CBERS image orientation using roads as ground control. It is based on an iterative strategy involving three steps. In the first step, an operator identifies on the image the ground control roads and supplies along them a few seed points, which could be sparsely and coarsely distributed. These seed points are used by the dynamic programming algorithm for extracting the ground control roads from the image. In the second step, it is established the correspondences between points describing the ground control roads and the corresponding ones extracted from the image. In the last step, the corresponding points are used to orient the CBERS image by using the DLT (Direct Linear Transformation). The two last steps are iterated until the convergence of the orientation process is verified. Experimental results showed that the proposed methodology was efficient with several test images. In all cases the orientation process converged. Moreover, the estimated orientation parameters allowed the registration of check roads with pixel accuracy or better.

Myxopapillary ependymoma of the posterior mediastinum

A left paravertebral mass discovered incidentally on routine examination in a 39-year-old woman is described. Computerized tomography studies revealed a 7 × 6 cm, well circumscribed, noncalcified soft tissue mass with lobular borders abutting the left inferior pulmonary vein and descending aorta. It was not possible to determine the exact anatomic location of the mass based on the imaging studies as both peripheral lung tumors and posterior mediastinal lesions may exhibit the imaging findings described here. At thoracotomy, the mass was seen to be well circumscribed, focally attached to the pleura but without involvement of lung parenchyma, and situated in the left posterior mediastinum. On histological examination, the lesion showed the classical features of myxopapillary ependymoma. Immunohistochemical studies confirmed this impression by demonstrating strong positivity of the tumor cells for S-100 protein, glial fibrillary acidic protein, and CD99 and negative staining with other differentiation markers. A review of the literature with a discussion of the histologic and radiologic differential diagnosis of these lesions is presented. © 2006 Elsevier Inc. All rights reserved.

The Canny detector with edge region focusing using an anisotropic diffusion process

This paper proposes a methodology for edge detection in digital images using the Canny detector, but associated with a priori edge structure focusing by a nonlinear anisotropic diffusion via the partial differential equation (PDE). This strategy aims at minimizing the effect of the well-known duality of the Canny detector, under which is not possible to simultaneously enhance the insensitivity to image noise and the localization precision of detected edges. The process of anisotropic diffusion via thePDE is used to a priori focus the edge structure due to its notable characteristic in selectively smoothing the image, leaving the homogeneous regions strongly smoothed and mainly preserving the physical edges, i.e., those that are actually related to objects presented in the image. The solution for the mentioned duality consists in applying the Canny detector to a fine gaussian scale but only along the edge regions focused by the process of anisotropic diffusion via the PDE. The results have shown that the method is appropriate for applications involving automatic feature extraction, since it allowed the high-precision localization of thinned edges, which are usually related to objects present in the image. © Nauka/Interperiodica 2006.

Avaliação do uso da terra em micro̧bacia utilizando uma matriz de partição fuzzy

Informatics evolution presently offers the possibility of new technique and methodology development for studies in all human knowledge areas. In addition, the present personal computer capacity of handling a large volume of data makes the creation and application of new analysis tools easy. This paper aimed the application of a fuzzy partition matrix to analyze data obtained from the Landsat 5 TMN sensor, in order to elaborate the supervised classification of land use in Arroio das Pombas microbasin in Botucatu, SP, Brazil. It was possible that one single training area present input in more than one covering class due to weight attribution at the signature creation moment. A change in the classification result was also observed when compared to maximum likelihood classification, mainly when related to bigger uniformity and better class edges classification.

Internal adaptation of cast titanium crowns

As the adaptation of titanium crowns obtained by Rematitan Plus investment, specific for titanium, is not recognized to be suitable, this study evaluated the effect of the concentration of the specific liquid and the temperature of the mold of investments on the internal misfit of crowns cast on commercially pure titanium. Individual dies of epoxy resin were obtained, representing teeth prepared for full-crown restoration with a 6-degree axial surface convergence angle and shoulder (1.0 mm). For the waxing of each crown, a ring-shaped stainless steel matrix (8.0mm internal diameter; 7.5 mm height) was adapted above the individual dies of epoxy resin. The Rematian Plus investment was mixed according to the manufacturer's instructions using two different concentrations of the specific liquid: 100%, 75%. Casting was performed in a Discovery Plasma Ar-arc vacuum-pressure casting machine with molds at temperatures of 430°C, 515°C and 600°C. The crowns were cleaned individually in a solution (1% HF + 13% HNO3) for 10 min using a ultrasonic cleaner, with no internal adaptations, and luted with zinc phosphate cement under a 5 kg static load. The crown and die assemblies were embedded in resin and sectioned longitudinally. The area occupied by cement was observed using stereoscopic lens (10X) and measured by the Leica Qwin image analysis system (mm2). The data for each experimental condition (n=8) were analyzed by Kruskal-Wallis non-parametric test (á=0.05). The results showed that liquid dilution and the increase in mold temperature did not significantly influence the levels of internal fit of the cast titanium crowns. The lowest means (±SD) of internal misfit were obtained for the 430°C/100%: (7.25 mm2 ±1.59) and 600°C/100% (8.8 mm2 ±2.25) groups, which presented statistically similar levels of internal misfit.

Influence of surface sealants on microleakage of composite resin restorations

Purpose: The purpose of this study was to verify the influence of surface sealants and dentin adhesive systems on the microleakage of composite restorations. Methods: Class V cavities were made on the buccal faces of 100 permanent third molars and restored with Z250. After 24 hours, they were submitted to polishing and finishing processes. The teeth were divided into groups according to the sealant agent: group 1 - Single Bond; group 2 - Opti Bond Solo Plus; group 3 - Fortify; group 4 - Fortify Plus; and group 5 - control without sealant. The analysis of immediate microleakage was performed in 10 restorations from each group, soon after the sealing. The other 10 specimens from each group were submitted to tooth-brushing and thermal cycles. The teeth were isolated and immersed in 2% methylene blue solution, washed in tap water, and sectioned in the buccolingual direction. The percentage of marginal leakage was calculated using an image analysis program, and results were submitted to analysis of variance and Tukey's test. Results: All the sealed groups demonstrated lower microleakage values compared to the control group. Group 3, sealed with Fortify, presented the lowest mean microleakage values. Conclusion: The application of surface sealants effectively decreased the microleakage in composite resin restorations.