We have investigated the surface morphology of electrically stressed AlGaN/GaN high electron mobility transistors using atomic force microscopy and scanning electron microscopy after removing the gate metallization by chemical etching. Changes in surface morphology were correlated with degradation in electrical characteristics. Linear grooves formed along the gate edges in the GaN cap layer for...

We present a detailed Monte Carlo simulation of electron transport incorporating both and X-valley states in GaAs-based quantum cascade lasers QCLs . states are calculated using the K ·p method, while X states are obtained within the effective mass framework. All the relevant electron-phonon, electron-electron, and intervalley scattering mechanisms are included. We investigate the X-valley leak...

Concurrent observations of Lyman continuum (LyC) and Lyman α (Lyα) emission escaping from star-forming systems at low redshift are essential to understanding the physics of reionization at high redshift (z & 6). Some have suggested reionization is dominated by numerous small galaxies with LyC escape fractions fe ∼ 10%, while others suggest mini-quasars with higher fe might also play a role. At ...

background: intraoperative radiation therapy (iort) technique is used to treat a surgically exposed tumor or tumor bed in the treatment of locally advanced intraabdominal, retroperitoneal, pelvic, thoracic, breast and soft tissue tumors. one way to perform iort is to use an existing linac and modify the treatment head using an applicator system. in this study the objectives were to design, and ...

Protecting intellectual property is a major challenge for many firms. This paper examines how compensation arrangements are influenced by the mechanisms firms use to protect their intellectual property. Consistent with firms being concerned about employees leaving to exploit R&D related information on their own or with competing firms, I find that executives’ unvested equity holdings and total ...

N-terminally substituted lysine derivatives of gramicidin A (gA), [Lys1]gA and [Lys3]gA, but not glutamate- or aspartate-substituted peptides have been previously shown to cause the leakage of carboxyfluorescein from liposomes. Here, the leakage induction was also observed for [Arg1]gA and [Arg3]gA, while [His1]gA and [His3]gA were inactive at neutral pH. The Lys3-containing analogue with all t...

The target in electron linear accelerator plays an important role in the production of photon. Different materials and thickness of target have influence on dose rate. For 6MeV electron beam, this study gives the thickness of target for several materials in which the dose rate can be higher and drain electron can be lower. Then a X-ray target had been designed for 6MeV electron linac by FLUKA s...

Short-term reliability and robustness of 110 nm AlN/GaN HEMTs has been evaluated by means off-state, semi-on state on-state step stress tests on devices having different gate-drain distance, LGD. While breakdown voltages critical scale almost linearly with LGD, failure mode remains unchanged in all tested devices, consists an increase gate leakage, accompanied a positive shift threshold voltage...