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The improvement of corrosion performance at high temperatures of coatings in which the alumina composition in Yttria-stabilized zirconia (YSZ-Al2O3) was varied in 3 different percentages was studied. These systems were deposited on AISI 304L stainless steel substrates using plasma spraying. The determination of the corrosion rate was performed in a corrosive environment containing 20% Na2SO4 and 80% V2O5, at temperatures ranging from 800 °C to 900 °C. The structural characterization was determined by X-ray diffraction (XRD), and the analysis of the surface after exposure at 900°C was performed by scanning electron microscopy (SEM). The best performing system was the one containing 40% alumina, due to the morphology and structural change. [ABSTRACT FROM AUTHOR]

Ti/TiN bilayers were deposited onto silicon [100] and RUS-3 steel substrates by using the d.c. magnetron sputtering at substrate temperature of 400°C, a d.c. power of 80W and applying a bias voltage of -50V. With the aim to study the effect of the nitrogen content in the Ar/N2 gas mixture of the discharge gases on the corrosion velocity of the steel coated with the Ti/TiN bilayers, three nitrogen concentrations were used. RUS-3 samples with and without coating were characterized. The chemical bonding presents in the bilayes was study by Fourier Transform Infrared Spectrsocopy (FTIR). The crystal structural was examined by x-ray diffraction and corrosion behavior was studied by potenciodynamic polarization test (Tafel curves) and electrochemical impedance spectroscopy (EIS). It was found a decrease of 95% in the corrosion velocity and an increase in the polarization resistance (from 6.8 KΩ to 60.3 KΩ) when was used the minor nitrogen content in the Ar/N2 gas mixture. [ABSTRACT FROM AUTHOR]

Aluminum nitride thin films were deposited onto Si [100] and Rus-3 steel substrates by reactive magnetron sputtering tech-nique from an A1 (99.9%) target, in order to study the influence of the d.c. bias polarisation voltage on the obtained films. EDS analysis showed that films presented compositions of A1 and N between 89% and 85% and 10% and 14%, respectively. By means of FTIR analysis, was found the presence of active modes around 680 cm-1 associated to the A1N wurtzita phase, and around 600, 950 and 980 cm-1 associated to A1-N amorphous structures and oxides in the films. The electro-chemical properties of the coatings growth at different bias voltages were compared with the RUS-3 substrate, by means of electrochemical impedance spectroscopy (EIS), and with Tafel polarization curves. The corrosion speed of the coatings growth at 0 and -80V (27.9 and 9.5 mpy, respectively) were lowers than that from the steel without coating (33.1 mpy), showing the protective effect of the A1N deposited films. [ABSTRACT FROM AUTHOR]

Vanadium Nitride (VN) thin films were grown by reactive d.c. magnetron sputtering technique, from a vanadium target (99.9%). During the films growth the N2 concentration was varied in the Ar/N2 gas mixture. Films were deposited onto silicon [100] substrate at 400°C. Structural, compositional and mechanical characterization were performed by X-ray Diffraction (XRD), Elastic Forward Analysis (EFA) and nanoindentation, respectively. X-ray diffraction patterns show the presence of [111], [200] and [220] crystallographic orientations associated to the VN cubic phase. EFA analysis indicates that when the N2 content in the was varied in 10, 20 and 30%, is found that the nitrogen content in the films was between 27 y 30% and the oxygen content was higher (≥%30) for the alls films. On the other hand, hardness and elastic modulus were around 17 y 220 GPa, respectively, for the films deposited at different N2 concentrations. [ABSTRACT FROM AUTHOR]

TiN monolayer and Ti/TiN multilayer hard coatings with thickness between 2.5 and 3.0 µm were deposited by the r.f. (13.56 MHz) magnetron sputtering multitarget set up of the Tecnological and Development Center ASTIN. In order to determine the influence of the bilayers number and type of substrate on mechanical properties of deposited multilayer system, Ti/TiN coatings with 5, 10 15 and 20 bilayers were grown on to steel AISI 4140, AISI 5160, S600 and silicon (100) substrates. The Ti/TiN multilayers were deposited by alternated variation of nitrogen gas flow in to the chamber. Chemical composition and phase analysis were investigated by Energy Dispersive X-ray Spectroscopy (EDX) and X-ray Diffraction Spectroscopy (XRD), respectively. The microstructure and topography were analyzed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Calotest, scratch test and microindentation measurements were used to evaluate the thickness, adherence and hardness of the coatings. An adherence and hardness improvement were observed by increasing the bilayers number of the coatings, obtained the highest performance by the hard coating multilayer grown on to steel AISI 5160 substrates. [ABSTRACT FROM AUTHOR]

A quantitative statistical study was done on digitized atomic force microscope (AFM) images of La2/3Ca1/3MnO3 (LCMO) thin films. Films were grown via sputtering technique at high-oxygen pressures, with 78 nm layer thicknesses on (100) oriented SrTiO3 substrate. We have systematically varied the substrate temperature during deposition between 700°C and 880°C, around the optimized growth temperature of 850 °C to study the influence of the growth parameters on the properties of the films. The films were characterized by thermal resistivity measurements to determine the insulator to metallic phase transition temperature existing in this material in block and in thin films. By using a specific self-designed algorithm, we can extract from digitized AFM-images the quantitative values of roughness parameters, i.e., interface width, lateral correlation length, and roughness exponent. Herein, we report substrate temperature dependence of the parameters describing roughness. We will correlate the growth parameters, roughness parameters and insulatormetal transition temperature in these ferromagnetic LCMO thin films. [ABSTRACT FROM AUTHOR]

Tungsten Carbide (W-C) thin films were obtained by r.f. (13.56 MHz) magnetron co-sputtering process in a argon background gas, from a mosaic targets of carbon C (99.9%) and tungsten W (99.9%) with different W and C concentrations. The thin films were deposited at temperatures between 300 and 500°C onto the silicon (100) and AISI D3 steel substrates. Energy Dispersive X-ray spectroscopy analysis showed that the different hexagonal WC and orthorhombic W2C subcarbide obtained phases, directly depended of tungsten concentration in the mosaic targets, and of the deposition temperature. Fourier Transform Infrared Spectroscopy (FTIR) results of films deposited from different mosaic targets reveled the presence of a peak at 1730 cm-1 associated to the C=O, carbonyls groups and a width band centered near 1340 cm-1 in which are two modes of cubic and hexagonal phases of WC at 1144 and 1220 cm-1, respectively. [ABSTRACT FROM AUTHOR]

We studied the magnetic properties of thin films of La2/3Ca1/3MnO3 grown by pulsed laser deposition on single crystal of SrTiO3 (001) substrate. All samples exhibited low roughness and good cristalinity as indicated from X-ray difractometry and topographical perfilometry, respectively. We investigated the plume of laser ablation during the growth by means of the optical emission spectroscopy; it founded the characteristic atomic peaks of La, Ca, MnO y O. The magnetic properties of magnetic films were analized by means of the dependence of magnetization with temperature and magnetic field and it showed a strong dependence of Curie temperature. [ABSTRACT FROM AUTHOR]

Multilayered coatings of CrN/ZrN were deposited on silicon (100) and steel AISI 420 by PVD magnetron sputtering to evaluate potential industrial applications of these coatings. Conditions of deposition were 6.6x10-3 mbar of working pressure with Ar/N2 relation in mixture gases of 93:7 and a temperature of the substrate of 250 °C. Surfaces of the multilayer samples were characterized structural, morphologic and mechanically by X-ray diffraction, atomic force microscopy, Berkovich nanoindentation and Vickers microindentation, respectively. Grain size of the coatings varied as a function of the bilayers number, from 113 ± 9 nm to 99 ± 6 nm for samples with 1 and 30 bilayers, respectively. Hardness values obtained by nanoindentation also varied from 10 ± 1 GPa to 21 ± 2 GPa for samples with 1 and 30 bilayers, respectively. Finally, Hardness Vickers microindentation imprints were used to qualitatively evaluate the coatings mechanical behavior. Coatings of 15 and 30 bilayers exhibited bigger fracture toughness under loads of 500gf and 1000gf, regarding wiht others systems. These properties serve as a basis to propose the coating roughness with 15 and 30 bilayers for industrials applications on steel substrates. [ABSTRACT FROM AUTHOR]

Iatrogenic brachial plexus injury is an uncommon but potentially severe complication of shoulder reconstruction for instability that involves dissection near the subscapularis muscle and potentially near the brachial plexus. We examined the relationship of the brachial plexus to the glenoid and the subscapularis muscle and evaluated the proximity of retractors used in anterior shoulder surgical procedures to the brachial plexus. Eight fresh-frozen cadaveric shoulders were exposed by a deltopectoral approach. The subscapularis muscle was split in the middle and dissected to reveal the capsule beneath it. The capsule was split at midline, and a Steinmann pin was placed in the equator of the glenoid rim under direct visualization. The distance from the glenoid rim to the brachial plexus was measured with calipers with the arm in 0 degrees, 60 degrees, and 90 degrees of abduction. The brachial plexus and axillary artery were within 2 cm of the glenoid rim, with the brachial plexus as close as 5 mm in some cases. There was no statistically significant change in the distance from the glenoid rim to the musculocutaneous nerve, axillary artery, medial cord, or posterior cord with the arm in various degrees of abduction. Retractors placed superficial to the subscapularis muscle or used along the scapular neck make contact with the brachial plexus in all positions tested.

Acute bronchial asthmatic episodes represent one of the most common respiratory emergencies in medical practice. Its maximum expression "status asthmaticus", is an entity of low incidence in our medium, still it is a risk to the physical integrity of the patient. The management of an acute attack of asthma can be focused on doing away with the bronchial spasm and decreasing the inflammatory effects, as well as improve the movement of secretion and this way, maintain adequate alveolar ventilation. The full knowledge of the physiopathology behind the illness and medical treatment used to improve the patient's well-being, are necessary for the patient's full recuperation. The different components which comprise the integral management of an episode of status asthmaticus are analyzed in unison, emphasizing the data included in the clinical chart, medical management and other therapeutic measures employed.

The Zawacki method was selected for the evaluation of the 20 patients admitted to our Burn Centre after the terrorist attack on 18 June 1987. The group comprised seven men and 13 women whose ages ranged from 25 to 66 years. The TBSA burn averaged 53 per cent and FTSA burn averaged 32.65 per cent; 25 per cent had respiratory lesions and 10 per cent reported previous bronchopulmonary pathology. The definitive assessment of mortality probability was made between 18 and 24 h after the accident. Of the group, 30 per cent died. All except one had a mortality probability of 100 per cent, 10 per cent of these patients survived. In general, complications appeared during the first 3 weeks; among the infections there was no predominant bacterial species and we had no pseudomonas sepsis cases; respiratory infections were the most important and serious and the most common cause of death. Prophylactic treatment was a determining factor for improving survival. The predominant sequelae were hypertrophic scars and 64 per cent of survivors still suffer with functional sequelae, however 78 per cent of the group have returned to their normal work.