6 research outputs found
Effect of screening of the electron-phonon interaction on the temperature of Bose-Einstein condensation of intersite bipolarons
Here we consider an interacting electron-phonon system within the framework
of extended Holstein-Hubbard model at strong enough electron-phonon interaction
limit in which (bi)polarons are the essential quasiparticles of the system. It
is assumed that the electron-phonon interaction is screened and its potential
has Yukawa-type analytical form. An effect of screening of the electron-phonon
interaction on the temperature of Bose-Einstein condensation of the intersite
bipolarons is studied for the first time. It is revealed that the temperature
of Bose-Einstein condensation of intersite bipolarons is higher in the system
with the more screened electron-phonon interaction.Comment: 6 pages, 4 figure
Side effects of anabolic androgenic steroids abuse
Long-term side effects of high doses of anabolic androgenic steroids self-administration were evaluated in this study. Twenty male bodybuilders, voluntarily starting steroid self-administration, were followed every 6 months over 2 years. Physical examination, haematological, metabolic and endocrine variables, semen analysis, hepatic and prostate ultrasound and echocardiographic evaluations were performed. LH values (baseline 3.43 +/- 1.75) were suppressed at 18 (1.98 +/- 1.99) (p = 0.026) and 24 (2.43 +/- 2.17) (p = 0.026), and FSH (3.95 +/- 2.01) at 6 (3.01 +/- 2.16) (p = 0.031), 12 (2.45 +/- 2.54) (p = 0.029), 18 (2.02 +/- 2.29) (p = 0.032) and 24 (3.42 +/- 2.64) (p = 0.032) months and SHBG (34.11 +/- 10.88) values significantly lowered at 12 (24.81 +/- 12.49) (p < 0.05), 18 (21.28 +/- 11.15) (p < 0.01), 24 months (25.42 +/- 11.16) (p < 0.01). A significant decrease in spermatozoa count (p < 0.01), and fertility index (p = 0.01) occurred. HDL-cholesterol (baseline 56.94 +/- 13.54) was reduced at 18 (41.86 +/- 14.17) (p < 0.01) and 24 (43.82 +/- 18.67) (p < 0.05) months and Apo A-1 at 12 (p < 0.001), 18 (p = 0.05) and 24 (p = 0.05) months. The most important long-term adverse effects were lower fertility and the impairment of lipid profile associated with an increased cardiovascular ris
Front-end process modeling in silicon
Front-end processing mostly deals with technologies associated to junction formation in semiconductor devices. Ion implantation and thermal anneal models are key to predict active dopant placement and activation. We review the main models involved in process simulation, including ion implantation, evolution of point and extended defects, amorphization and regrowth mechanisms, and dopant-defect interactions. Hierarchical simulation schemes, going from fundamental calculations to simplified models, are emphasized in this Colloquium. Although continuum modeling is the mainstream in the semiconductor industry, atomistic techniques are starting to play an important role in process simulation for devices with nanometer size features. We illustrate in some examples the use of atomistic modeling techniques to gain insight and provide clues for process optimization