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This paper presents a new finite element model capable of predicting the onset of micro-plasto-hydrodynamic (MPH) lubrication and the amount of lubricant escaping from surface pockets in metal forming. The present approach is divided in two steps. First, a simulation at the macroscopic level is conducted. Then, a second simulation highlighting microscopic liquid lubrication mechanisms is achieved using boundary conditions provided by the first model. These fluid-structure interaction computations are made possible through the use of the Arbitrary Lagrangian Eulerian (ALE) formalism. The developed methodology is validated by comparison to experimental measurements conducted in plane strip drawing. The effect of physical parameters like the drawing speed, the die angle and the strip thickness reduction is investigated. The numerical results show good agreement with experiments. [ABSTRACT FROM AUTHOR]

Background: The significance of basal renal nitric oxide (NO) availability in the regulation of renal perfusion and sodium excretion in human congestive heart failure (CHF) has not been described previously. Methods and Results: We studied the effects of acute systemic NO synthesis inhibition with NG-monomethyl-L-arginine (L-NMMA) in 12 patients with CHF and 10 healthy control subjects (CON) in a randomized placebo-controlled study. Effect parameters were renal plasma flow (RPF), renal vascular resistance (RVR), glomerular filtration rate (GFR), urine sodium excretion and plasma levels of vasoactive hormones. L-NMMA was associated with a significant decrease in RPF (CON-LNMMA: -13 ± 3% [P = .014]; CHF-LNMMA: -17 ± 7% [P = .017]) and a profound increase in RVR in both CHF and CON (CON-LNMMA: +26 ± 6% [P = .009]; CHF-LNMMA: +37 ± 70% [P = .005]). Significant decreases in sodium excretion were found in both CHF-LNMMA and CON-LNMMA. Relative changes from baseline were not statistically different between CHF-LNMMA and CON-LNMMA. After L-NMMA, RPF values correlated inversely with plasma aldosterone in CHF-LNMMA (P = .01). L-NMMA induced an increase in A-type natriuretic peptide (ANP) only in CHF-LNMMA (+18 ± 8%; P = .035), which correlated significantly with basal ANP levels (P = .034). Conclusions: There was no difference in the renal response to L-NMMA in CHF vs CON, suggesting that the impact of NO on renal perfusion and sodium excretion is maintained in stable CHF. We suggest that NO influences the release of ANP during high levels of atrial stretch in CHF. [ABSTRACT FROM AUTHOR]

Abstract: This study examines the effect of the orography on two heavy precipitation events (HPE1 and HPE2) which exceeded 100mm in 24h and affected the Eastern Pyrenees (Andorra, NE Spain and SE France) in the NW Mediterranean. High resolution simulations (3km) performed with the Weather and Research Forecasting model (WRF) were compared with precipitation observations to assess the ability of the model to reproduce the spatial distribution of the rainfall field in this mountainous area and determine the prominent factors of intense precipitation occurrence. The analysis has been focused on the association of the heavy rainfall to the existing atmospheric disturbance and the presence of orographic induced vertical motions. For both episodes at 3km resolution, on exposed mountain sides, vertical moisture fluxes characterized with the orographic moisture flux index (OMF) yielded values above 7gkg−1 ms−1, consistent with previous studies. The spatial distribution of the OMF maximum is in agreement with the observed rainfall maxima over the Eastern Pyrenees according to the combination of two factors, namely the normal orientation of mountain range with respect to the prevailing moisture flows and large wind speeds of the impinging upstream flows (~20m/s). Moreover, the analyses of a triggering term and moist Froude number also reflect the complexity of applying theoretical results obtained in idealized simulations with 2D mountain ridges to numerical simulations with dynamic evolving conditions over areas with complex orography as the Eastern Pyrenees. [Copyright &y& Elsevier]

In this paper a study of the radio propagation environment of electromagnetic waves prevailing in the lower troposphere of the Western Mediterranean basin is presented. Deviations from atmospheric average or standard radio propagation conditions (anomalous propagation or AP) can affect significantly the quality of weather radar observations and other telecommunication systems. This is particularly important when ducting or superrefraction is present and spurious echoes resulting from the interaction of the beam with the ground or sea surface may appear. These AP conditions occur mainly when temperature inversions or strong moisture gradients are present. The period covered in this study ranges from 1999 to 2008 and conditions were derived from the Weather Research and Forecasting (WRF) modeling system, using the Japanese 25-year Reanalysis (JRA25) dataset as initial and boundary data. From the WRF model, we use the temperature, moisture, and pressure fields with a grid length of 30-km horizontal resolution and 250 m vertical resolution to compute several indices such as the Vertical Refractivity Gradient, Vertical Modified Refractivity Gradient and a Ducting Index. Results obtained show that on the Western Mediterranean coast the most favorable conditions for superrefraction are found in summer, while the most affected areas are the Gulf of Valencia, the Strait of Gibraltar and the Northern Gulf of Lion. Additionally, a comparison with radiosonde data recorded in Barcelona (NE Spain) is also performed indicating an overall agreement between model and observational data despite a tendency to decrease subrefractive events by the WRF model. [ABSTRACT FROM AUTHOR]

The major risks due to metal pollution of sediments consist of leaching to groundwater and potential toxicity to animals and/or plants. The objective of this study was to evaluate by means of an ecotoxicological approach the effects of the addition of cutting marble sludges on the mobile metal fraction of sediments polluted with heavy metals. The study was carried out on two sediments derived from mining activities in Portman Bay (SE, Spain) polluted by heavy metals. These sediments were mixed with sludges left after the cutting of marble. The results obtained by leaching experiments showed that the addition of marble cutting sludge, consisting mainly of carbonates, to a heavy-metal polluted sediment produces a decrease of available metal forms. The carbonate content seems to play a role in chemical stabilisation of metals and in a decrease of toxicity of sediments. The leached solutions have a non-toxic effect. The mild remediation by addition of sludge has moreover effects to long term. [Copyright &y& Elsevier]

Mining-contaminated surface waters and acid mine drainage frequently contain high levels of potentially harmful metal(oid)s, some of which are especially relevant because of their toxicity- As, Pb, Cd and, to a lesser extent, Cu and Zn. Limestone filler is used to immobilise these elements taking advantage of its high carbonate content and lower cost. Metal(oid)s are immobilised through precipitation and adsorption in the filler, as confirmed by theoretical calculations and experimental data. The results obtained concerning the concentrations of the elements studied show that they are retained by the filler in concentrations below than those established by the European directive 2008/108/EC. Analyses of the filler were carried out by X-ray diffraction and Raman spectroscopy, and the latter technique was seen to be particularly useful for qualitatively monitoring the processes that take place and for assessing the state of the filler. • Waters contaminated by potentially toxic elements, are used to mimic acid mine drainage leachates. • Limestone fillers used for remediating metal(loid)s contaminated soils are reviewed. • Factors affecting limestone - metal(loid)s interaction are discussed. • Raman spectroscopy is used as a diagnostic tool for monitoring element trace sorption by limestone filler. [ABSTRACT FROM AUTHOR]