Javier Ochoa - Academia.edu (original) (raw)
Papers by Javier Ochoa
Cardiovascular Ultrasound, 2006
Background: Renal artery stenosis (RAS) is one of the main causes of secondary systemic arterial ... more Background: Renal artery stenosis (RAS) is one of the main causes of secondary systemic arterial hypertension. Several non-invasive diagnostic methods for RAS have been used in hypertensive patients, such as color Doppler ultrasound (US). The aim of this study was to assess the sensitivity and specificity of a new renal Doppler US direct-method parameter: the renal-renal ratio (RRR), and compare with the sensitivity and specificity of direct-method conventional parameters: renal peak systolic velocity (RPSV) and renal aortic ratio (RAR), for the diagnosis of severe RAS.
Journal of Alloys and Compounds, 1999
International Journal of Refractory Metals & Hard Materials, 1997
As an effort to investigate a possible extent of substitution of W, the metal from strategic mine... more As an effort to investigate a possible extent of substitution of W, the metal from strategic mineral, by a less strategic V, phase relations, microstructure, and hardness and fracture strength, of powder metallurgically processed 90 mass% [(l -y)WC-yVC]-10 mass% Co alloys are studied. Throughout the composition eight phases, cc-Co, P-Co, WC, V,C,, V,C,, q3(Co,W,C), q,(Co,W,C) and graphite C(g), were encountered and a distinct microstructural difference existed across midcomposition. On the basis of combined mechanical properties of hardness and fracture strength the alloys between y = 0.2 and 0.4, which correspond to 18-36 mass % VC, were most promising. Contrary to the antagonistic relations between hardness and toughness commonly encountered in cemented carbides and hard materials, the hardness and fracture strength of the present WC-VC-1OCo alloys were nearly parallel. 0 1997 Published by Elsevier Science Limited
Cardiovascular Ultrasound, 2006
Background: Renal artery stenosis (RAS) is one of the main causes of secondary systemic arterial ... more Background: Renal artery stenosis (RAS) is one of the main causes of secondary systemic arterial hypertension. Several non-invasive diagnostic methods for RAS have been used in hypertensive patients, such as color Doppler ultrasound (US). The aim of this study was to assess the sensitivity and specificity of a new renal Doppler US direct-method parameter: the renal-renal ratio (RRR), and compare with the sensitivity and specificity of direct-method conventional parameters: renal peak systolic velocity (RPSV) and renal aortic ratio (RAR), for the diagnosis of severe RAS.
Journal of Alloys and Compounds, 1999
International Journal of Refractory Metals & Hard Materials, 1997
As an effort to investigate a possible extent of substitution of W, the metal from strategic mine... more As an effort to investigate a possible extent of substitution of W, the metal from strategic mineral, by a less strategic V, phase relations, microstructure, and hardness and fracture strength, of powder metallurgically processed 90 mass% [(l -y)WC-yVC]-10 mass% Co alloys are studied. Throughout the composition eight phases, cc-Co, P-Co, WC, V,C,, V,C,, q3(Co,W,C), q,(Co,W,C) and graphite C(g), were encountered and a distinct microstructural difference existed across midcomposition. On the basis of combined mechanical properties of hardness and fracture strength the alloys between y = 0.2 and 0.4, which correspond to 18-36 mass % VC, were most promising. Contrary to the antagonistic relations between hardness and toughness commonly encountered in cemented carbides and hard materials, the hardness and fracture strength of the present WC-VC-1OCo alloys were nearly parallel. 0 1997 Published by Elsevier Science Limited