Biblioteca de la Estación Experimental de Zonas Áridas

Sección: Noticias. Noticias internasEl traslado, el pasado mes de octubre, de la Estación Experimental de Zonas Áridas (EEZA) a su nueva sede en el campus de la Universidad de Almería llevó a su biblioteca también a cambiar de instalaciones.N

Examination of carbon partitioning into austenite during tempering of bainite

The redistribution of carbon after tempering of a novel nanocrystalline bainitic steel consisting of a mixture of supersaturated ferrite and retained austenite has been analyzed by atom probe tomography. No direct evidence supporting the additional carbon enrichment of austenite beyond that initially achieved during the bainite heat treatment was obtained during subsequent tempering of this high carbon, high silicon steel.The authors gratefully acknowledge the support of the Research Fund for Coal and Steel and the Spanish Ministry of Science and Innovation for funding this research under the contracts RFSR-CT-2008-00022 and MAT2007 – 63873, respectively. Research at the Oak Ridge National Laboratory SHaRE User Facility was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. A.J. Clarke gratefully acknowledges support from Los Alamos National Security, LLC, operator of the Los Alamos National Laboratory under contract number DE-AC52-06NA25396 with the U.S. Department of Energy and the Advanced Steel Processing and Products Research Center, a National Science Foundation Industry/University Cooperative Research Center at the Colorado School of Mines and the Inter-American Materials Collaboration ProgramPeer reviewe

Комплексный подход к выбору метода борьбы с гидратообразованием на Заполярном нефтегазоконденсатном месторождении (ЯНАО)

В бакалаврской работе изучены способы образования газовых гидратов. Проанализированы основные методы борьбы с гидратами в газопромысловых и газотранспортных системах. Приведена методика расчета количества ингибитора, необходимого для предупреждения гидратообразования для сеноманского газа.In the bachelor's work, methods for the formation of gas hydrates are studied. The main methods of combating hydrates in gas production and gas transmission systems are analyzed. A method for calculating the amount of inhibitor required to prevent hydrate formation for Cenomanian gas is presented

Обзор и назначение экономических информационных систем

ObjectivesThis study was designed to develop a technique to selectively increase the sympathetic tone to the heart by cardiac sympathetic nerve stimulation (SNS).BackgroundAccess to the cardiac sympathetic neurons may allow modulating the adrenergic tone of the heart while avoiding systemic side effects.MethodsCardiac sympathetic nerves course within neural sleeves along the subclavian artery. Because of this proximity, transvascular SNS was attempted with electrode catheters inside the subclavian artery in 16 pigs.ResultsRight/left (R-/L-) SNS (20 Hz) during ventricular pacing at 200/min evoked a >100% increase of left ventricular systolic pressure (baseline: 51 ± 1 mm Hg; L-SNS: 118 ± 26 mm Hg; R-SNS: 116 ± 33 mm Hg; p < 0.001) while systemic vascular resistance remained unchanged. There was a sigmoid dose-response curve with rapid on- and offset of the effect during SNS initiation/cessation. Positive inotropic effects persisted for 12 h of continued SNS (n = 4). Besides positive dromotropic effects, L-SNS/R-SNS yielded a 41% and 77% sinus rate increase, respectively.ConclusionsThe neural adrenergic tone to the heart can be selectively increased by catheter stimulation of cardiac efferent sympathetic nerves

Speckle tracking echography allows sonographic assessment of diaphragmatic loading

Introduction: Assessment of diaphragm function should ideally be assessed using magnetic twitch pressure or esophageal and gastric balloons. Conventional sonographic techniques as thickness and fractional thickening (FT), only provide limited insight in diaphragm function. Speckle tracking echocardiography allows reliable quantification of muscle function by tracking of grey patterns and their motion; strain as parameter of muscle deformation and strain rate as deformation velocity. Aim: To investigate whether speckle tracking can quantify loading of the diaphragm, superior to FT. Methods: 13 healthy volunteers underwent an inspiratory loading protocol with recording of transdiaphragmatic pressure (Pdi) and diaphragm electromyography (EMGdi). Inspiratory loading of 0 to 30% of maximal inspiratory pressure was applied in random order for 5 minutes per applied load. Diaphragmatic sonography was performed using a 2-4 MHz linear phased array transducer positioned at the right-lateral thoracic wall in the anterior axillary line longitudinal to the body axis. Ultrasound recordings of the diaphragm were made at the marked location during 10 seconds. Results: Increased inspiratory loading increased Pdi and EMGdi. Sonographic markers of contractility increased with incremental loading. Pdi correlated with strain (r=0.75; p=0.000) and strain rate (r=0.77; p=0.000). Contrarily, FT was not correlated with Pdi. Conclusion: Speckle tracking of the diaphragm can detect changes in diaphragmatic loading up to 30% of maximal inspiratory pressure. It might be a valuable tool to detect changes in loading in specific patient categories, including patients with acute respiratory failure and ventilated ICU patients

Исследование влияния внешних факторов на изоляцию нефтепогружных кабелей

Нефтяная отрасль - это специфический пласт деятельности, требующий особого подхода к изготавливаемому оборудованию. Истощение поверхностных запасов нефти привело к тому, что процесс добычи сырья происходит на большей глубине, чем ранее, что требует использования более прочного оборудования, в том числе и кабеля для нефтяной промышленности. Цель работы: Исследование влияния механических нагрузок и времени старения на пробивное напряжение изоляционных материалов, применяемых в нефтепогружных кабелях.The oil industry is an activity where a special approach to manufactured equipment is required. Depletion of surface oil reserves has led to the fact that the process of extracting raw materials occurs at a greater depth than previously, so it is necessary to use more durable equipment, including cables for the oil industry

Feasibility and efficacy of bypassing the right ventricle and pulmonary circulation to treat right ventricular failure: an experimental study

<p>Abstract</p> <p>Background</p> <p>Right ventricular failure (RVF) and -support is associated with poor results. We aimed for a new approach of right - sided assistance bypassing the right ventricle and pulmonary circulation in order to better decompress the right ventricle and optimize left ventricular filling.</p> <p>Methods</p> <p>From a microaxial pump (Abiomed), a low resistance oxygenator (Maquet and Novalung) and two cannulas (28 and 27 Fr) a system was set up and evaluated in an ovine model (n = 7). Connection with the heart was the right and left atrium. One hour the system was operated without RVF and turned of again. Then a RVF was induced and the course with the system running was evaluated. Complete hemodynamic monitoring was performed as well as echocardiography, flow measurement and blood gas analysis.</p> <p>Results</p> <p>The overall performance of the system was reliable. Without RVF no relevant changes of hemodynamics occurred; blood gases were supra normal. In RVF a cardiogenic shock developed (MAP 35 ± 13 mmHg, CO 1,1 ± 0,7 l/min). Immediately after starting the system the circulation normalized (significant increase of MAP to 85 ± 13 mmHg, of CO to 4,5 ± 1,9). Echocardiography also revealed right ventricular recovery. After stopping the system, RVF returned.</p> <p>Conclusions</p> <p>Bypassing the right ventricle and pulmonary circulation with an oxygenating assist device, which may offer the advantages of enhanced right ventricular decompression and augmented left atrial filling, is feasible and effective in the treatment of acute RVF. Long time experiments are needed.</p

Die Ventilation mit biphasic positive airway pressure (BIPAP) im experimentellen akuten Lungenschaden : der Einfluß des transpulmonalen Drucks auf Gasaustausch und Hämodynamik

OBJECTIVE: We investigated whether improvement in ventilation perfusion distribution during mechanical ventilation using biphasic positive airway pressure (BIPAP) with spontaneous breathing may be attributed to an effectively increased transpulmonary pressure (PTP) and can also be achieved by increasing PTP during controlled ventilation. DESIGN: In 12 pigs with saline lavage-induced lung injury we compared the effects of BIPAP to pressure-controlled ventilation with equal airway pressure (PCVAW) or equal transpulmonary pressure (PCVTP) on ventilation perfusion distribution assessed by the multiple inert gas elimination technique (MIGET).Measurements and results: Intrapulmonary shunt was 33±11% during BIPAP, 36±10% during PCVAW and 33±15% during PCVTP (p= n.s.). BIPAP resulted in higher PaO2 than PCVAW (188±83 versus 147±82 mmHg, p<0.05), but not than PCVTP (187±139 mmHg). Oxygen delivery was significantly higher during BIPAP (530±109 ml/min) versus 374±113 ml/min during PCVAW and 353±93 ml/min during PCVTP (p<0.005). Tidal volume with PCVTP increased to 11.9±2.3 ml/kg, compared to 8.5±0.8 with BIPAP and 7.6±1.4 with PCVAW (p<0.001) and cardiac output decreased to 3.5±0.6 l/min (BIPAP 4.9±0.8 and PCVAW 3.9±0.8, p<0.006). CONCLUSIONS: In experimental lung injury, BIPAP with preserved spontaneous breathing was effective in increasing regional PTP, since pressure-controlled ventilation with the same PTP resulted in similar gas exchange effects. However, PCVTP caused increased airway pressures and tidal volumes, whereby, with BIPAP, less depression of oxygen delivery and cardiac output were observed. BIPAP could be useful in maintaining pulmonary gas exchange and slightly improving oxygenation without interfering with circulation as strongly as PCV does