Quantification of Residual Stress Relief by Heat Treatments in Austenitic Cladded Layers.

The effect of the heat treatment on the residual stresses of welded cladded steel samples is analyzed in this study. The residual stresses across the plate's square sections were determined using complementary methods; applying diffraction with neutron radiation and mechanically using the contour method. The analysis of the large coarse grain austenitic cladded layers, at the feasibility limits of diffraction methods, was only made possible by applying both methods. The samples are composed of steel plates, coated on one of the faces with stainless steel filler metals, this coating process, usually known as cladding, was carried out by submerged arc welding. After cladding, the samples were submitted to two different heat treatments with dissimilar parameters: one at a temperature of 620 °C maintained for 1 h and, the second at 540 °C, for ten hours. There was some difference in residual stresses measured by the two techniques along the surface of the coating in the as-welded state, although they are similar at the welding interface and in the heat-affected zone. The results also show that there is a residual stress relaxation for both heat-treated samples. The heat treatment carried out at a higher temperature showed sometimes more than 50% reduction in the initial residual stress values and has the advantage of being less time consuming, giving it an industrial advantage and making it more viable economically.

Labile and stable soil organic carbon and physical improvements using groundcovers in vineyards from central Spain.

Mediterranean vineyards are usually managed with continuous tillage to maintain bare soils leading to low organic matter stocks and soil degradation. Vineyards are part of the Mediterranean culture, their management can be sustainable. We propose the setup of two types of groundcovers with the aim to assess their potential influence to improve soil properties. A field trial was performed to compare the effects of a seeded (Brachypodium distachyon) and spontaneous groundcovers, on a set of soil parameters, in comparison with the traditional tillage in four vineyards located in the center of Spain. Three years after the groundcovers establishment soil organic carbon stocks increased up to 1.62 and 3.18Mgha-1 for the seeded and the spontaneous groundcovers, respectively, compared to conventional tillage. Both labile and stable fractions improved their soil organic carbon content with the use of groundcovers, particularly the labile fraction. Moreover, soil structure and functional soil properties improved through better aggregate stability, pore connectivity and infiltration rates. The higher root biomass input of the spontaneous groundcovers derived in higher soil organic carbon increases and soil quality improvement. Consequently, under low rainfall conditions (<400mmperyear) spontaneous vegetation, properly managed according to site conditions, is an effective soil management strategy to revert soil degradation and increase soil quality in Mediterranean vineyards.

Use of dendrochronological method in Pinus halepensis to estimate the soil erosion in the South East of Madrid (Spain).

The rate of soil erosion in pine forests (Pinus halepensis) located in the Southeast of Madrid has been estimated using dendrochronological analysis based on the change in ring-growth pattern from concentric to eccentric when the root is exposed. Using 49 roots spread across five inclined areas, it has been found that the length and direction of the hillsides, as well as their vegetation cover affect the rate of erosion, while the slope itself does not. The erosion rates found for the different areas studied vary between 3.5 and 8.8 mm year(-1), that is between 40 and 101 t ha(-1) year(-1) respectively. These values are between 2 and 3 times greater than those predicted by USLE, for which this equation underestimates soil loss for Central Spain's Mediterranean conditions. Nonetheless, both methods (using dendrochronology to determine actual soil loss and theoretical prediction with USLE) are able to establish the same significant differences among the areas studied, allowing for the comparative estimate of the severity of the area's erosion problem.

Spatial variability of the soil erodibility parameters and their relation with the soil map at subgroup level.

This project takes a look at the variation of the parameters related to soil erodibility (fractions of clay, silt, fine and coarse sand; organic matter, permeability, and structure) coming from soil pits from the Community of Madrid's soil map (Spain), according to Soil Taxonomy at subgroup level. It draws the conclusion that map erodibility shouldn't be estimated from a soil map because the K factor obtained does not present significant differences among the different types of soil. One or more key factors related with soil erodibility must be taken into account if erodibility maps are to be drawn. This research has shown that silt and structure could be considered key factors for erodibility maps of the area, but not significant differences have been found in important factors such as clay or organic matter due to the wide range of data variance. In order to elaborate erosion risk maps the use of the K factor from the physiographical map is a good alternative. When data are grouped according to these criteria significant differences in K factor are shown. Erodibility was greater in soils developed over gypsic material, with a value of 0.63+/-0.28, than in high plateaus (locally know as alcarrias), with a value of 0.40+/-0.18. In order to adequately represent soil erodibility, a kriging geostatistic technique is used, which reduces the variation of the factors considered when they are found to correlate, as is the case with the parameters considered to calculate K factor.

Effect of vegetal cover on runoff and soil erosion under light intensity events. Rainfall simulation over USLE plots.

The erosive power of frequent light rainfalls is studied in this paper. Field experiments of simulated rainfall (Intensity, 21 mm h(-1) and kinetic energy, 13.5 J m(-2) mm(-1)) were conducted over 8 bounded USLE plots (80 m(2) each) with a slope of 10%. In 4 plots the soil was almost bare (<4% vegetation cover); the other 4 plots had almost full cover with natural vegetation in one year. Runoff and sediment yield was recorded. The results revealed the efficiency of vegetation cover reducing runoff and sediments. Runoff and sediments were negligible in covered plots. Therefore, in bare plots, although sediment yield was generally low, averaging 74+/-43 kg ha(-1), the mean of runoff achieved a coefficient of 35%, this magnitude has to be taken into consideration in this region verging on aridity. Rains around 13.5 J m(-2) mm(-1) of kinetic energy are quite frequent in the study area (34% of recorded rains en 12 years). If we would consider the usual lower limits from the literature, we would be ignoring an important percent of natural rainfall episodes.

Linfangioleiomiomatose / Lymphangioleiomyomatosis

Os autores descrevem um caso de linfangioleiomiomatose pulmonar e retroperitoneal em uma mulher de 52 anos. Discutem apresentaçäo clínica, diagnóstico e tratamento

Obturação dos canais radiculares correlação entre avaliação radiográfica e infiltração através do corante azul de metileno a 2 por cento: estudo "in vitro" / Root canal filling correlation between radiographic evaluation ane microleakage by 2 per cent methilene blue solution: in vitro study

Nesta pesquisa, foram realizadas avaliações radiográficas da obturação de canais radiculares pela técnica de condensação lateral (estudo "in vitro"), em 40 dentes unirradiculares extraídos de humanos, em duas indidências: vestíbulo-lingual (radiografia clínica), e mésio-distal (radiografia proximal). Após avaliação das imagens radiográficas, de acordo com os graus excelente e insatisfatório, os espécimes forma impermeabilizados com esmalte para unhas, exceto os 2mm apicais, e imersos em corante Azul de Metileno a 2 por cento. Após 48 horas, foram lavados em água corrente, secos, e, divididos aleatoriamente em 2 grupos de 20 espécimes. No grupo 1 os espécimes, foram seccionados longitudinalmente nos sentidos anatômicos vestíbulo-lingual e os do grupo 2 no sentido mésio-distal. Posteriormente foram mensuradas as infiltrações apicais, através de régua milimetrada com auxílio de lupa x4. As infiltrações receberam os graus de avaliação em intensa e discreta. A análise estatística comprovou, que os dados obtido no experimento não demonstrou evidência de que a proporção de graus excelente obtidos com a incidência vestíbulo-lingual seja diferente da proporção dos mesmos graus obtidos com a incidência mésio-distal. Enquanto que na análise do grau de infiltração apical comparativamente a análise radiográfica, mostrou que entre 75 por cento dos terços apicais que receberam grau excelente na avaliação radiográfica, 72,5 por cento apresentaram infiltração discreta, levando-nos a apontar para uma provável associação entre a avaliação radiográfica, mais especificamente, quando a avaliação radiográfica é considerada excelente, espera-se que a infiltração, caso exista, seja apenas discreta na grande maioria dos casos

Avaliação pós-preparo biomecânico na presença de resíduo de Endo PTC no terço apical de canais radiculares: estudo in vitro / Evaluation after biomecanic preparation to the presence of residue of Endo PTC in the apical third of root canals: in vitro study

Por meio de uma análise clínica e fotográfica, esta pesquisa se propôs a avaliar a presença de resíduo de Endo PTC no terço apical de canais radiculares, após o preparo biomecânico, realizado pela técnica biescalonada de FAVA (1984), sem instrumento apical foraminal, com instrumento apical foraminal; pela técnica biescalonada de FAVA (1984), sem instrumento apical foraminal; pela técnica de instrumentação clássica com instrumento apical foraminal e pela técnica de instrumentação clássica sem instrumento apical foraminal. Utilizaram-se 80 molares inferiores humanos extraídos, levando-se em consideração apenas a raíz distal, que após instrumentação e secagem, foram submetidas à secção do terço apical e testadas através da reação do Hipoclorito de Sódio e Peróxido de Uréia. Os resultados obtidos pela análise estatística demonstraram que a técnica biescalonada de FAVA (1984), com instrumento apical foraminal foi a que melhor removeu os resíduos do Endo PTC

Literatura endodontica e avanço técnico-científico da especialidade / Endodontic literature and its technical scientific advance

Foi realizado um levantamento bibliográfico da literatura endodôntica dos anos de 1989 a 1998, e catalogadas as publicações encontradas, nacionais e internacionais, através do Index Dental Literature e demais revistas e jornais brasileiros, idealizando-se um caderno, onde as publicações foram divididas por ano, tipo de estudo, se In Vitro ou se In Vivo, e categorias de estudo, cuja finalidade foi de se obter a prevalência de publicações ou quais temas foram os mais pesquisados, verificando se existe ou não diferença significativa entre os percentuais de publicações e suas diferentes variáveis. Foram catalogadas neste estudo o total de 1572 publicações, das quais, os dois maiores percentuais ocorreram nos anos de 89 e 90. do total de trabalhos catalogados, 968 (61,6 por cento) foram realizados "In Vivo" e 604 (38,34 por cento) restantes foram realizados "In Vitro", existindo diferença significativa entre as proporções de tipo de estudo

Aspectos macroscópicos e microscópicos da polpa dentária: correlaçäo entre diagnóstico clínico e histopatológico / Macroscopic and microscopic aspects of dental pulp

Quarenta e três espécimes de polpas extirpadas de 29 dentes de pacientes com idade entre 15 e 25 anos, foram estudadas para fazer uma correlaçäo do diagnóstico clínico, aspecto macroscópico das mesmas e o diagnóstico histopatológico. Das alteraçöes pulpares detectadas, as alteraçöes regressivas tiveram registro significante, onde detectamos calcificaçöes difusas e cálculos em 46 por cento e 49 por cento respectivamente, enquanto fibrose (discreta, moderada e intensa), foi verificada em mais de 60 por cento dos casos. Nesta investigaçäo ficou comprovado que o diagnóstico macroscópico pode sugerir significativamente, indicaçäo de polpas passíveis de recuperaçäo por tratamento conservador