We present numerical simulations and measurements of shot noise in resonant tunneling structures. We show that when electron-electron interaction through Coulomb force and Pauli exclusion is properly taken into account, the main features of noise behavior of such devices can be correctly predicted. Electron-electron interaction is shown to be responsible for the suppression of shot noise in the...

rolling-based seismic isolation systems, in which rollers of circular or non-circular section are used, are less expensive and easier to manufacture. however, this type of isolation suffers from either lack of restoring or re-centering capability, or weakness against uplift forces. to resolve the first shortcoming the use of elliptical as well as pillow-shape rolling parts has been suggested, a...

background and objectives: patients at intensive-care-unit (icu) are at risk of acquiring nosocomial infections which contributes to higher rates. approximately 25% of all hospital infections and 90% of outbreaks occur in icus. multi-resistant gram-negative rods are important pathogens in icus, causing high rate of mortality. the purpose of this study was to investigate the antimicrobial resist...

the nosocomial infections, caused by multi-drug resistant bacteria, are the most important cause of mortality throughout the world. one important mechanism against beta-lactam antibiotics is the production of beta-lactamases. enterobacteriaceae and non-fermentative bacteria, like pseudomonas aeruginosa and acinetobacter baumannnii may produce these enzymes. currently, there is no vaccine to pre...

conclusions with regards to the continuous changing in causative microorganisms isolated from patients with uti and antibiotic sensitivity patterns, it is recommended that bacterial sensitivity patterns in populations are determined in any region annually. . objectives this study aimed to detect and also compare the frequency and drug resistance pattern of gram negative bacteria isolated from p...

antibiotic resistance of intensive care unit (icu) born aerobic gram-negative bacteria was evaluated during a six months period at a teaching hospital in tehran, and determination of the validity of the results obtained from disc diffusion tests, using discs manufactured in iran. disc susceptibility tests using iranian and standard discs (diffusion discs available in international markets) were...