Tras las huellas de Cristo médico. Manual de Teología pastoral sanitaria.[Reseña]

Reseña de Angelo BRUSCO-Sergio PINTOR, Tras las huellas de Cristo médico. Manual de Teología pastoral sanitaria, Sal Terrae, Santander 2001, 14 x 21, ISBN 84- 293-1391-5

Selection bias due to conditioning on a collider

Effect estimates may be biased when the study design or the data analysis is conditional on a collider—a variable that is caused by two other variables. Causal directed acyclic graphs are a helpful tool to identify colliders that may introduce selection bias in observational research.S

Influence of 2 (wt%) titanium addition on the oxidation resistance of tungsten

The oxidation behaviour of W-2Ti (wt%) alloy has been evaluated in dry air at 600, 700 and 800 °C for 100 h and the kinetics compared with those for pure tungsten. Titanium addition exerts a beneficial effect on the oxidation resistance of pure tungsten. The mass gain is almost five times smaller than in the case of commercial tungsten and three times smaller than that of tungsten prepared by powder metallurgy at 600 °C. This effect is even higher at 700 and 800 °C, where the titanium addition suppresses catastrophic oxidation of pure tungsten. Major influence of titanium regards the suppression of massive microcracking in the scale, avoiding the development of the typical non-protective multilayered scale pattern formed on pure tungsten.This research was supported by the Agencia Estatal de Investigación of Spain (PID2019-105325RB-C33/AEI/10.13039/501100011033) and by the Regional Government of Madrid through TECHNOFUSIÓN(III)CM (S2018/EMT-4437) project cofinanced by Structural Funds (ERDF and ESF). The support of the Regional Government of Madrid through the multi-annual agreement with UC3M (Excellence of University Professors-EPUC3M14 and in the context of the V PRICIT - Regional Programme of Research and Technological Innovation) is also acknowledge

On the oxidation mechanism of pure tungsten in the temperature range 600-800 ºC

The oxidation behavior of International Thermonuclear Experimental Reactor (ITER)-reference tungsten grade has been evaluated in dry air in the temperature range 600-800 °C. At 600 °C , the scale remained protective while the integrity of W₁₈O₄₉ layer was kept. Rapid increase in mass gain resulted from massive cracking at local areas in the W₁₈O₄₉ layer. Then, a coarse non-protective columnar WO₂.₉₂ scale was developed which favoured rapid inward oxygen transport into the alloy. At 700 and 800 °C, growth stresses in the scale were released through local cracking. At this stage, WO₂.₉₂ became progressively transformed into WO₃ when the oxygen partial pressure increased across the scale thickness.This investigation was supported by the Spanish Ministry of Science and Innovation (ENE2008 06,403 C06 04). The financial support from the Comunidad de Madrid, through the program TECHNOFUSION, Grant S2009/ENE 1679