Noninvasive mechanical ventilation with high pressure strategy remains a “double edged sword” ?

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Influencia del contenido de impurezas sobre la densidad y viscosidad de fluidos oleosos

In this work, as a case study, the measurement of the density (ρ) and the dynamic viscosity (µ) of 12 different fluids (taken from a conventional oil mill) has been carried out. The variability of the samples processed shows that their impurity contents c (between 0.5-5.87%), together with the temperature t (which varied between 20-30 ºC), can affect the values of ρ and µ. However, this variation has been shown to be different depending on the case, being of the order of 1% for density or even more than 50% for dynamic viscosity. The fact that µ can be sensitive to the presence of impurities opens up a line of study that could be used to estimate such impuritiy content, in real time, by means of relatively simple methods.En este trabajo, como caso de estudio, se ha llevado a cabo la medida de la densidad (ρ) y de la viscosidad dinámica (µ) de 12 fluidos diferentes tomados de una almazara convencional. La variabilidad de las muestras procesadas indica que el contenido de impurezas c (entre el 0,5%-5,87 %), junto con la temperatura t (que varió nominalmente entre 20 ºC-30 ºC), pueden afectar a los valores de ρ y µ. Sin embargo, esta variación se ha mostrado diferente dependiendo del caso, siendo del orden del 1 % para la densidad o incluso mayor del 50% para la viscosidad dinámica. El hecho de que µ pueda ser sensible a la presencia de impurezas abre una línea de estudio que podría ser aprovechada para estimar tal contenido de impurezas, en tiempo real, por medio de métodos relativamente sencillos

Ada real-time services and virtualization

Virtualization techniques have received increased attention in the field of embedded real-time systems. Such techniques provide a set of virtual machines that run on a single hardware platform, thus allowing several application programs to be executed as though they were running on separate machines, with isolated memory spaces and a fraction of the real processor time available to each of them.This papers deals with some problems that arise when implementing real-time systems written in Ada on a virtual machine. The effects of virtualization on the performance of the Ada real-time services are analysed, and requirements for the virtualization layer are derived. Virtual-machine time services are also defined in order to properly support Ada real-time applications. The implementation of the ORK+ kernel on the XtratuM supervisor is used as an example

Environmental Forensics Study of Crude Oil and Petroleum Product Spills in Coastal and Oilfield Settings: Combined Insights from Conventional GC-MS, Thermodesorption-GC-MS and Pyrolysis-GC-MS

A representative set of five oil spill samples from four different regions displayed different product characteristics and different levels of weathering. Three of them were taken along shorelines affected by marine oil spill events, viz., Aboño and Prestige (Spain) and Deepwater Horizon (USA) and the other two were taken at inland oil spill sites (Angola and Kuwait). A multi-faceted environmental forensics approach revealed key molecular features. In addition to the conventional GC/MS analysis of saturated and aromatic fractions, the polar fractions also were analyzed, revealing a complex series of linear alkanones in those oil samples particularly enriched in aliphatics. Thermodesorption-GC-MS of the whole oils was also employed to further test its efficacy as a tool for the rapid fingerprinting of environmental contamination. The method was shown to accurately detect most of the essential features recognized in the conventional GC-MS analysis of the saturated and aromatic fractions, although in some instances with less sensitivity and poorer resolution. Characteristics so recognized included the distributions of normal and isoprenoid alkanes, saturate and aromatic biomarkers, and polycyclic aromatic compounds such as alkylphenanthrenes and alkyldibenzothiophenes. Sequential pyrolysis of the post-thermodesorption residue and asphaltene pyrolysis yielded similar results, indicating that the residue consists primarily of asphaltenes. Thermodesorption and pyrolysis GC-MS also recognized substances likely to be associated with spill cleanup efforts that were not detected by conventional analysis

Predictors of noninvasive ventilation failure in critically ill obese patients: a brief narrative review

   Non-invasive ventilation ( NIV ) has been used successfully for the management of acute respiratory failure (ARF) more often in the last two decades than previously. Unfortunately, NIV can have failure rates ranging from 5% to 50% and patient selection is the key to success. There are particular groups of patients that are more likely to benefit from NIV. For patients with hypoventilation syndrome (OHS) this treatment can be beneficial. This review seeks to evaluate the effectiveness of NIV in acute ARF and determine predictors of NIV failure in morbidly obese patients. Only a few studies have investigated NIV success or failure in these patients. NIV was most often effective when patients were carefully selected. Obese patients who exhibited early NIV failure had a high severity score at admission. In contrast, more than half of hypercapnic patients with decompensated OHS exhibited a delayed but successful response to NIV. Patients with decompensation of OHS had better prognosis and response to NIV than other hypercapnic patients. They required more aggressive NIV settings, a longer time to reduce paCO2 levels , and more frequently a delayed but successful response to NIV which should encourage the use of NIV rather than early intubation. Since clear predictors of NIV failure have not been identified, a strict and prolonged monitoring is mandatory.