Strengthening mechanisms in thermomechanically processed NbTi-microalloyed steel

The effect of deformation temperature on microstructure and mechanical properties was investigated for thermomechanically processed NbTi-microalloyed steel with ferrite-pearlite microstructure. With a decrease in the finish deformation temperature at 1348 K to 1098 K (1075 °C to 825 °C) temperature range, the ambient temperature yield stress did not vary significantly, work hardening rate decreased, ultimate tensile strength decreased, and elongation to failure increased. These variations in mechanical properties were correlated to the variations in microstructural parameters (such as ferrite grain size, solid solution concentrations, precipitate number density and dislocation density). Calculations based on the measured microstructural parameters suggested the grain refinement, solid solution strengthening, precipitation strengthening, and work hardening contributed up to 32 pct, up to 48 pct, up to 25 pct, and less than 3 pct to the yield stress, respectively. With a decrease in the finish deformation temperature, both the grain size strengthening and solid solution strengthening increased, the precipitation strengthening decreased, and the work hardening contribution did not vary significantly

Predictors of functional recovery (FR) for elderly hospitalized patients in a geriatric evaluation and management unit (GEMU) in Taiwan

Elderly patients who are hospitalized with acute illnesses frequently have adverse outcomes. To maintain functional independence, the geriatric evaluation and management unit (GEMU) was established to provide the opportunity for functional recovery (FR). This study's aim was to investigate potential prognostic factors for functional improvement in a GEMU of Taichung Veterans General Hospital, Taiwan. A total of 117 elderly patients (age, 80.0 +/- 6.3 years, 84.6% males) were enrolled. A comprehensive geriatric assessment and functional status evaluation, including the functional reach test (FRT) and the timed up-and-go (TUG) test, were performed. FR was defined by a greater than 10% improvement in the Barthel Index (BI) before GEMU discharge. Lower BI (44.7 +/- 25.2 vs. 68.7 +/- 34.5, p<0.001), lower instrumental activities of daily living (IADL) scores (1.8 +/- 1.5 vs. 3.5 +/- 2.6, p < 0.001), impaired FRT (83.3% vs. 63.5%, p = 0.028), and impaired TUG test (94.4% vs. 74.6%, p = 0.008) were predictive factors for functional improvement. On multivariate logistic regression, an impaired TUG test (Odds ratio = OR = 6.18, 95% confidence interval = 95% C.I. = 1.69-22.6, p = 0.006) was an independent variable associated with FR. The results indicate that elderly hospitalized patients, even with poor physical function, could benefit from geriatric integrated care delivered by a GEMU. (C) 2010 Elsevier Ireland Ltd. All rights reserved