Effects of Microstructure on the Strain Rate Sensitivity of Advanced Steels

The dependence of the strain rate sensitivity of advanced ~1 GPa tensile strength steels on the phases present in their microstructures was studied by testing different steels at 0.005 and 500 s−1. The high strain rate tests were performed using a Kolsky bar setup, while the quasi-static tests were performed using a universal testing machine. The two main steels of interest were the Ferrite-Martensite DP980 and the Ferrite-Martensite-Austenite QP980; the latter being a transformation induced plasticity (TRIP) assisted steel. For comparison, ferritic CR5 mild steel and austenitic stainless steel 201 were also tested under the same conditions. Though the differences in the steel chemistries were not taken into account, the results obtained here suggest a strong relationship between the phase-content of the steel and its response to the changes in the loading rate. The relationships between the observed mechanical behavior and the phases present in the microstructure are discussed

Influence of common genetic variation on lung cancer risk: meta-analysis of 14 900 cases and 29 485 controls

Recent genome-wide association studies (GWASs) have identified common genetic variants at 5p15.33, 6p21-6p22 and 15q25.1 associated with lung cancer risk. Several other genetic regions including variants of CHEK2 (22q12), TP53BP1 (15q15) and RAD52 (12p13) have been demonstrated to influence lung cancer risk in candidate- or pathway-based analyses. To identify novel risk variants for lung cancer, we performed a meta-analysis of 16 GWASs, totaling 14 900 cases and 29 485 controls of European descent. Our data provided increased support for previously identified risk loci at 5p15 (P = 7.2 × 10−16), 6p21 (P = 2.3 × 10−14) and 15q25 (P = 2.2 × 10−63). Furthermore, we demonstrated histology-specific effects for 5p15, 6p21 and 12p13 loci but not for the 15q25 region. Subgroup analysis also identified a novel disease locus for squamous cell carcinoma at 9p21 (CDKN2A/p16INK4A/p14ARF/CDKN2B/p15INK4B/ANRIL; rs1333040, P = 3.0 × 10−7) which was replicated in a series of 5415 Han Chinese (P = 0.03; combined analysis, P = 2.3 × 10−8). This large analysis provides additional evidence for the role of inherited genetic susceptibility to lung cancer and insight into biological differences in the development of the different histological types of lung cance

Improved quality nonpolar a-plane GaN/AlGaN UV LEDs grown with sidewall lateral epitaxial overgrowth (SLEO)

High quality nonpolar a-plane GaN templates were grown by utilizing sidewall lateral epitaxial overgrowth (SLEO) technique with threading dislocation density of similar to 10(6)-10(7) cm(-2). 360 run GaN/AlGaN multiple quantum well ultraviolet light emitting diodes were grown with metalorganic chemical vapor deposition. Reduced defect density SLEO a-plane, planar a-plane, and planar c-plane templates were co-loaded for device growth and processed together in order to make relative device performance comparison. For SLEO a-plane LEDs EL peak position was measured at 360 nm and it was independent of drive current, The linewidth of the emission was 7 nm. The series resistance of these diodes was as low as 16,5 0 and the forward voltage was measured as 4.08 V at 20 mA. The external quantum efficiency of the high quality SLEO a-plane devices was similar to 275x higher than planar a-plane devices. The highest output power was realized at 200 mA as 65 mu W. The effect of contact geometry on electrical and optical characteristics of the devices was also discussed