TCOs

IF(SRATE.lt.EPSII) SRATE = EPSIT CALL VISCA(RVISC,POWER,VISC,SRATE,STEMP,RTEM,TCO)... 

CALL VISCA(RVISC, POWER, VI SC, . SRATE, STEMP, RTEM, TCO )... 

RVISC,POWER,Vise,SRATE,STEMP,RTEM,TCO)... 

Vise = RVISC- ( (4. SRATE) PINDX) EXP (-TCO (STEMP-RTEM) ... 

The isotope molybdenum-99 is produced in large quantity as the precursor to technetium-99y, a radionucleide used in numerous medical imaging procedures such as those of bone and the heart (see Medical imaging technology). The molybdenum-99 is either recovered from the fission of uranium or made from lighter Mo isotopes by neutron capture. Typically, a Mo-99 cow consists of MoO adsorbed on a lead-shielded alumina column. The TcO formed upon the decay of Mo-99 by P-decay, = 66 h, has less affinity for the column and is eluted or milked and either used directly or appropriately chemically derivatized for the particular diagnostic test (100). 

Certain neutral technetium complexes can be used to image cerebral perfusion (Fig. 4). Those in Figure 4a and 4b have been approved for clinical use. Two other complexes (Fig. 4c and 4d) were tested in early clinical trials, but were not developed further. An effective cerebral perfusion agent must first cross the blood brain barrier and then be retained for the period necessary for image acquisition. Tc-bicisate is retained owing to a stereospecific hydrolysis in brain tissue of one of the ester groups to form the anionic complex TcO(ECD) , which does not cross the barrier. This mechanism of retention is termed metaboHc trapping. 

Figure 4 shows the basic constmetion of the devices used in different appHcations, involving the deposition of multilayers of i -SiH of intrinsic (/), doped ), and closely aUied films, such as amorphous siHcon nitride, SiN, and transparent conducting oxide (TCO). As in crystalline... 

The TCO is synthesized from SnO, B203, Sn2P207, A1203, and other precursors. The nature of the insertion mechanism of lithium into the Fuji material has... 

Figure 18. First- and second- cycle constant current charge/discharge curves of a tin composite oxide (TCO) electrode. Prepared by using data kindly provided by Fujifilm Celltech Co., Ltd. [342].

The good cycling stability of the tin in TCO is quite unusual, because the electrochemical cycling of Li ASn and also of other Li alloy electrodes is commonly associated with large volume changes in the... 

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