4,716 research outputs found
LANDSAT D local user terminal study
The effect of the changes incorporated in the LANDSAT D system on the ability of a local user terminal to receive, record and process data in real time was studied. Alternate solutions to the problems raised by these changes were evaluated. A loading analysis was performed in order to determine the quantities of data that a local user terminal (LUT) would be interested in receiving and processing. The number of bits in an MSS and a TM scene were calculated along with the number of scenes per day that an LUT might require for processing. These then combined to a total number of processed bits/day for an LUT as a function of sensor and coverage circle radius
Excitonic Effects and Optical Spectra of Single-Walled Carbon Nanotubes
Many-electron effects often dramatically modify the properties of reduced
dimensional systems. We report calculations, based on an many-electron Green's
function approach, of electron-hole interaction effects on the optical spectra
of small-diameter single-walled carbon nanotubes. Excitonic effects
qualitatively alter the optical spectra of both semiconducting and metallic
tubes. Excitons are bound by ~ 1 eV in the semiconducting (8,0) tube and by ~
100 meV in the metallic (3,3) tube. These large many-electron effects explain
the discrepancies between previous theories and experiments.Comment: 6 pages, 3 figures, 2 table
Anesthesia in Hair Transplantation
Current hair transplantation techniques require a reliable anesthesia for long periods of time (2Â h or more). They demand hemostasis of extended surfaces on wide-awake patients. A combination of anesthetic agents and local vasoconstrictors is needed. We present customary technical characteristics of these procedures as local nerve blocks (supratrochlear nerve, supraorbital nerve, zygomaticotemporal nerve, auriculotemporal nerve, retroauricular nerve, lesser occipital nerve, great occipital nerve) and tumescent field anesthesia. The ordinary drug combinations for premedication and procedure are presented. Special emphasis is done to discuss recommendations to cope with undesirable events that may arise during anesthesia (vasovagal syncope, anesthetic toxicity, anaphylactic and allergic reactions)
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