237 resultados para processos de superfície


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The aim of this present work was to compare planialtimetric charts obtained from different risings using two different theodolite types, a total station, and a precision level, used as control. Using a total station, an area was marked with clear variations of relief, following a grid, with a distance of 20 meters among stakes. After that, the stakes were read by the total station and two theodolites of different precisions. The geometric leveling was done by a precision level. The data were input in the DataGeosis software and the numerical modelling of the land was made with mesh of maximum rigidity, generating planialtimetric representation for each rising. It was verified, through comparison of the four representations that little variations occur in relation to the control. The closest representation of the control was the planialtimetry based on the data from the total station, in which the representations obtained from the theodolites were identical among themselves. It was concluded that in the process of obtaining detailed planialtimetry of small areas, submitted to the grid, it was not necessary to use composed geometric leveling, reducing work to the exclusive use of a total station or conventional theodolite.

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Zoology laboratories at institutions of research and education have shown great demand for anatomical parts for practical lessons. However, although the bibliography is not necessarily scarce, analyses of the cost/benefit relations of such processes are rare, considering aspects such as preparation time, quality of the anatomical parts, and material and human resources. In addition to the common techniques already used, new low-cost products, not cited in literature and easily found in the market, were also tested. The main objective of this work was to elaborate and organize information on techniques of bone parts maceration for study collections, making comparative analyses on the cost/benefit relations of each technique. Twelve products were tested, evaluating experimental conditions such as: concentration and combination of reagents, temperature, pH and time of exposure of the parts to the reagents. The results indicated that the products recommended for the use in the maceration processes were: water, hydrogen peroxide and papaya juice (Carica papaya).

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The development of linear erosion processes is directly related with the environment natural characteristics or with modifications that have occurred on them by the anthropic action. In this context, the present article has as a general objective to evaluate the dynamic of the linear erosion processes and their relations with the evolution of the land use and with the lito-pedologic characteristics of the Cavalheiro hydrographic basin - Analândia, SP. In order to reach such objective, maps of erosive features and land use of several settings were elaborated, besides cartographic representations of the geological and pedological data of the study area. The obtained data were analyzed starting from the principles that concern to the General Systems Theory. Such analysis evidenced the intrinsic bond of the development of linear erosion processes with the several forms of land use and with the natural attributes of the studied area. Therefore, the methodological procedure adopted in this research has been considered as fundamental tool to understand the linear erosion processes dynamic, making it possible to take data of extreme relevance for the planning of the use and occupation of the land.

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Conectivity between the hydrologic regimen and the distribution of the vegetation there is already a lot is recognized by several researchers in the works of fluvial ecology. It can be affirmed that the geomorphology of the alluvial plain has an important paper in the constitution of the riparian vegetation. On the proposed study, traverse topographical profiles were elaborated in the island, recognition of the distribution of the vegetation and the zoning geomorphologic presented in profiles for the Mutum Island. It's located in the upper course of the Parana River, between the mouth of the Paranapanema River and the mouth of the Ivinhema River. It elapses of this study the succession of the strata of the riparian vegetation and the relationship with the morphology of the surface, in this case the relief as the main controller abiotic and selective of the species in the environmental. For the whole island it was possible to define three classes: Mutum Upper Unit, Mutum Lower Unit and Paleochannel. The presented discussion is resulted partial of the project called Processes of Conectivity and the Riparian Vegetacion in the high course of the Parana River, PR/MS.

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This paper presents the results from lineal trend surface analysis technique application. The purpose was to detect positive and negative anomalies in the rain measure distribution obtained by the meteorological radar Doppler, band S, located in Bauru, during the period of 21 of October/2004 to 29 of April/2005 in the areas of Assis and Piracicaba. Using three Z-R radar relations for rain quantification was chosen the specific equation Z = 32R1,65, as the best one. The results showed that the applied methodology was able to indicate the space distribution of the rain accumulated, identifying and locating the regions where there was rainy excess and rainy lack during each analyzed period. Such results indicate areas with larger pluvial impact and consequently more favorable for environmental damages.

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This article summarizes the implementation of an online process management, analysis, and optimization tool at Lwarcel Celulose e Papel, within the PIMS and MES philosophy, for process indicator implementation, understanding of variables, and their cause-effect relationship in the process, as well as the achievement of operational benchmarking. The process analysis, by means of statistical tools, allied to mathematical modeling algorithms used in Wedge, makes it possible to identify the relevant information for process and quality improvement with regard to efficiency, equipment maintenance, productivity, and uniformity of the end product quality, reduction of unwanted shutdowns, and quicker resolution of process problems.

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The study area comprises the western portion of the Marília Plateau, State of São Paulo, southeastern Brazil. The geological substrate encompasses Cretaceous sedimentary rocks of the Bauru Group and local Neocenozoic units like colluvium aprons, fluvial terrace deposits, in situ regoliths, and modern alluvial deposits. In a geomorphologic sense, the study area might be characterized as showing two main pediplanes, viz. P1 Surface (upper) and P2 Surface (lower), both surfaces are presently under dissecation processes. After the 1920's the expansion of the railroad system fostered the removal of the natural vegetation, which in turn was followed by the introduction of coffee, peanut, corn and cotton crops. This intense exploitation was conducted without respect to the soil carrying capacity and its natural susceptibility to erosional processes, including an aggressive form known as voçoroca. As a result, the study shows that the most susceptible material includes colluvium aprons, in situ regoliths, and colluvium-alluvium or alluvium deposits. The most critical situation is in the P2 Surface context, near the bottom of the Marília Plateau scarpment, where surface runoff can be very strong. Another point of active erosion is represented by the exposed walls of gullies and voçorocas, mainly in fluvial reaches subjected to talweg lowering. In a general sense, this study shows current evidence of erosional stability due to the ìntroduction of pastures as a predominant type of land occupation and to a series of erosion control procedures. Among these actions are terrace implantation, construction of small pits for runoff control, natural or induced reforestation by land owners. Despite these efforts, some erosion points remain chiefly in steeper country roads and trail stretches, in areas of concentration of cattle tracks (e.g., near cattle ponds), gullies or voçorocas exposed walls, and badly planned urbanization. The permanence of these erosion points demonstrates the necessity of a continuous monitoring of surface dynamics as well as a rapid and effective intervining measures of erosion and/or silting control.

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Soil flushing is an alternative remediation technology for soils contaminated with heavy metals, which the main contaminant removing process consists in percolating an extraction solution. This work aimed to use the response surface methodology to point out combinations among the parameters of the extraction solution (Na2EDTA concentration, volume e pH) in order to reduce the concentration of copper in a sandy soil to risk levels lower than the intervention levels for exposure scenarios adopted by the Environmental Company of Sao Paulo State. Thus, a series of tests in leaching columns were carried out using a Fluvisol artificially contaminated (1257,3 mg kg-1). The tests were conducted in triplicate and setup a central composite rotatable design with 15 different parameters combinations of the extraction solution and one replicate in the center point. Using 5% significance level, the adjusted model (R2 = 0,98) indicated combinations of Na2EDTA concentration, pH and volume of the extraction solution which allow reduction of copper concentration below levels reported by environmental agency of Sao Paulo State for industrial, residential, agricultural or maximum exposure scenarios.

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Objective: To evaluate the influence of different air abrasion protocols on the surface roughness of an yttria-stabilized polycrystalline tetragonal zirconia) (Y-TZP) ceramic, as well as the surface topography of the ceramic after the treatment. Method: Fifty-four specimens (7.5×4×7.5mm) obtained from two ceramic blocks (LAVA, 3M ESPE) were flattened with fine-grit sandpaper and subjected to sintering in the ceramic system's specific firing oven. Next, the specimens were embedded in acrylic resin and the surfaces to be treated were polished in a polishing machine using sandpapers of decreasing abrasion (600- to 1,200-grit) followed by felt discs with 10μm and 3μm polishing pastes and colloidal silica. The specimens were then randomly assigned to 9 groups, according to factors particle and pressure(n=6): Gr1- control; Gr2- Al 2O 3(50μm)/2.5 bar; Gr3- Al 2O 3(110μm)/2.5 bar; Gr4- SiO 2(30μm)/2.5 bar; Gr5- SiO 2(30μm)/2.5 bar; Gr6- Al 2O 3(50μm)/3.5 bar; Gr7- Al2O3(110μm)/3.5 bar; Gr8- SiO 2(30μm)/3.5 bar; Gr9- SiO 2(30μm)/3.5 bar. After treatments, surface roughness was analyzed by a digital optical profilometer and the morphology was examined by scanning electron microscopy (SEM). Data (μm) were subjected to statistical analysis by Dunnett's test (5%), two-way ANOVA and Tukey's test (5%). Results: The type of particle (p=0.0001) and the pressure (p=0.0001) used in the air abrasion protocols influenced the surface roughness values among the experimental groups (ANOVA). The mean surface roughness values (μm) obtained for the experimental groups (Gr2 to Gr9) were, respectively: 0.37 D; 0.56 BC; 0.46 BC; 0.48 CD; 0.59 BC; 0.82 A; 0.53B CD; 0.67 AB. The SEM analysis revealed that Al 2O 3, regardless of the particle size and pressure used, caused damage to the surface of the specimens, as it produced superficial damages on the ceramic, in the form of grooves and cracks. Conclusion: Al2O3 (110 μm/3.5 bar) air abrasion promoted the highest surface roughness on the ceramics, but it does not mean that this protocol promotes better ceramic-cement union compared to the other air abrasion protocols.

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This text presents some reflections about the educational and virtual processes of mathematics teachers drawing on research on the theme. Thus, in this text, considering our experiences with the development of online courses, we discuss issues such as collaboration in virtual environments, which contributes to more effective results in collaborative learning and reduces the potential of isolation of student/teacher that can occur in virtual environments. Through collaborative learning in a virtual community, students/teachers have the opportunity to practice and think in-depth about their learning experiences by sharing new ideas with the group and receiving critical and constructive feedback. Moreover, the virtuality formed by the environment of online courses supports educational spaces for teachers who teach mathematics. Thus, collaboration emerges as an essential element for construction of meanings and for sharing experiences on the practice of teaching.

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This study aimed at analyzing the geomorphologic dynamics and its relationship to human interference and ownership of relief, towards a systemic approach, through the interpretation, in an integrated manner, of cartographic documents made from techniques of geomorphologic cartography and of land use. By stereoscopic pairs of aerial photographs, it was prepared the Geomorphological Map and the Land Use Map, respectively based on Tricart's (1965) and Ceron and Diniz's (1966) technical procedures. The unit of the research analysis refers to the basin of Tijuco Preto Streamlet (SP) which is located at the Geomorphological Province of São Paulo state Peripheral Depression between latitudes 22°42'17 and 22°51'36 S, and longitudes 47°30'30 and 47°37'03. In general, it was possible to notice that this basin has been experiencing linear erosion processes, where it was mapped many erosion furrows, grooving and creeping, besides several slope breaks. These processes are associated with a conjunction of circumstances, and the anthropic one is mostly represented by sugarcane monoculture and by urbanization, which are crucial agents in activating erosion processes and in direct interfering on the dynamics of river and rain flow at the basin of Tijuco Preto Streamlet.

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The Pantanal wetland is an extensive depositional tract characterized by the presence of fluvial megafans, from which that of the Taquari River is the most extensive and well known. Located on the northern border of the Pantanal, the São Lourenço megafan is a large distributary fluvial system with an area of 16,000 km2, but poorly known regarding its geomorphological and geological features. The Sao Lourenço and the Taquari are coalescent megafans, having the Piquiri interfan meander river in between them. Based on the interpretation of satellite images and field validation, it was possible to identify channel patterns, to interpret depositional and erosional processes, to recognize the phenomena of river avulsion and to map depositional lobes. Three geomorphological zones were recognized on the São Lourenço megafan: 1) abandoned depositional lobes located in the upper/intermediate fan, composed of Pleistocene fluvial deposits and exhibiting distributary paleochannels on their surfaces, which are currently being dissected by tributary channels; 2) an active Holocene confined meander belt formed by fluvial aggradation in a N65E incised-valley; 3) active depositional lobes placed on the distal part of the system, which are the main site of sedimentation and are characterized by frequent avulsion events, channel bifurcation, distributary drainage pattern and the presence of depositional lobated landforms. The active depositional lobes were formed due to an important event of river avulsion that caused the lower portion of the meander belt to be abandoned.

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In the majority of cases of bone fracture requiring surgery, orthopedic implants (screw-plate and screw) are used for osteosynthesis and the infections associated with such implants are due to the growth of microorganisms in biofilms. The objective of this study was to identify microorganisms recovered from osteosynthesis implants used to fix bone fractures, to assess the viability of the cells and the ability of staphylococci to adhere to a substrate and to determine their sensitivity/resistance to antimicrobials. After surgical removal, the metal parts of austenitic stainless steel (ASTM F138/F139 or ISO NBR 5832-1/9) were transported to the Laboratory of Clinical Microbiology, washed in buffer and subjected to ultrasonic bath at 40±2 kHz for 5 minutes. The sonicated fluid was used to seed solid culture media and cell viability was assessed under the microscope by with the aid of a fluorescent marker. The production of extracellular polysaccharide by Staphylococcus spp. was investigated by means of adhesion to a polystyrene plate. The profile of susceptibility to antimicrobials was determined by the disk diffusion assay. The most frequently isolated bacteria included coagulase-negative Staphylococcus resistant to erythromycin, clindamycin and oxacillin. Less frequent were Pseudomonas aeruginosa resistant to trimethoprim/sulfamethoxazole and ampicillin, Acinetobacter baumannii resistant to ceftazidime, Enterobacter cloacae resistant to cephalothin, cefoxitin, cefazolin, levofloxacin and ciprofloxacin, Bacillus spp. and Candida tropicalis. The observation of slides by fluorescence microscope showed clusters of living cells embedded in a transparent matrix. The test for adherence of coagulase-negative Staphylococcus to a polystyrene plate showed that these microorganisms produce extracellular polysaccharide. In conclusion, the metal parts were colonized by bacteria related to orthopedic implant infection, which were resistant to multiple antibiotics.

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Objective: To evaluate fluoride ion release from two anhydrous glass ionomer cements (GICs) and two resin-modified GICs (RMGICs) before and after recharge with 2% neutral sodium fluoride for 4 min and after surface protection of the Maxxion R GIC with an adhesive system, a cavity varnish and a colorless nail polish. Method: A stainless steel 2x6 mm matrix was used for fabricating 5 specimens of each material, which were immersed in 5 mL of deionized water, renewed every 24 h. Measurements with a potentiometer were performed on days 1, 2, 9 and 17, in the 1st and 2nd phases, and the specimens were buffered with a TISAB III solution. In the 2nd phase, the specimens were subjected to recharge and immersed again in 5 mL of deionized water. In the 3rd phase, the GIC surfaces were protected and readings were made at 5 min, 24 h, 48 h and 72 h. Tukey's post-hoc and Student's t tests were used for statistical analyses (p<0.05). Results: There was statistically significant difference in the comparison between the 1st and 2nd phases for all materials, except at day 2 for Vidrion R and VitroFil LC. In the 3rd phase, it was observed that for all materials, comparison of the first 5 min with the other times revealed statistically significant differences among the means of fluoride ion release. In the comparison with the other times, both the varnish and the colorless nail polish presented statistically significant difference between 24 and 48 h as well as between 24 and 72 h. Conclusion: The anhydrous GICs were more effective in fluoride ion release and recharge compared with the RMGICs. Maxxion R presented a homogeneous and statistically significant behavior in both phases. All materials for surface protection were efficient and the colorless nail polish had the best behavior.

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In this work, surface modification of the Ti-6Al-4V alloy by irradiation with a Nd:YAG laser beam was studied. The matrix spacing was varied and the other parameters were kept constant. After theirradiation, the samples were immersed into SBF solution (Simulated Body Fluid) for 7 days at 37 ° C for nucleation and formation of calcium phosphates. After this period, the samples were subjected to a heat treatment at 600 °C. X-ray diffraction results indicated the formation of a mixture of phases containing hydroxyapatite and tricalcium phosphate. Infrared analysis demonstrated the presence of bands related to hydroxyapatite. SEM micrographs showed that different matrix spacing used leads to the formation of different morphologies.The 0.01 cm spacing induced the formation of microspheres, characteristic of the hydroxyapatite phase, while for 0.02 cm spacing, only a non-homogeneous coating was obtained. Therefore, the use of laser in the production of active surfaces for deposition of bioceramics proved to be viable, and the final coating has potential for applications in the field of dental implants.