1,1*- water carry-over behavior

Due to the identical behavior of GT-3 (16) and GT-4 on thin layer chromatography in addition to the ileum assays, these toxins are considered to be very closely related, if not identical. GT-3 likely represents a water soluble carry-over in the initial diethyl ether partition. In light of this observation, the effects of the crude ESAP on the guinea pig ileum previously reported (16) are quite understandable. We surmise that the first phase of Immediate, but reversible inhibition was ellicitied by GT-1 and GT-2 which have already been shown to be competitive in nature (16), and the second, irreversible phase was caused by GT-3. 

Because of its potential to form volatile species, the behavior of fission product iodine is of particular significance in this context. In Section 4.3.3. it was pointed out that both in the primary coolant and in the steam generator secondary-side water iodine is present as non-volatile iodide the measured carry-over rates to the main steam are identical with those of fission product cesium, indicating that carryover is exclusively effected by droplet transport (entrainment). 

Unfortunately, the size of the crystallographic problem presented by elastase coupled with the relatively short lifedme of the acyl-enzyme indicated that higher resolution X-ray data would be difficult to obtain without use of much lower temperatures or multidetector techniques to increase the rate of data acquisition. However, it was observed that the acyl-enzyme stability was a consequence of the known kinetic parameters for elastase action on ester substrates. Hydrolysis of esters by the enzyme involves both the formation and breakdown of the covalent intermediate, and even in alcohol-water mixtures at subzero temperatures the rate-limidng step is deacylation. It is this step which is most seriously affected by temperature, allowing the acyl-enzyme to accumulate relatively rapidly at — 55°C but to break down very slowly. Amide substrates display different kinetic behavior the slow step is acylation itself. It was predicted that use of a />-nitrophenyl amid substrate would give the structure of the pre-acyl-enzyme Michaelis complex or even the putadve tetrahedral intermediate (Alber et ai, 1976), but this experiment has not yet been carried out. Instead, over the following 7 years, attention shifted to the smaller enzyme bovine pancreatic ribonuclease A. 

Taylor et al. (T6, T7) have reported on wave velocities in upward cocurrent gas/film flow. It was found that the wave velocity increased rapidly with increasing gas flow rate but varied little with liquid flow rate. It was found, furthermore, that the individual wave velocities were not uniformly distributed around the mean value under given flow conditions, but that certain preferred velocities appeared to exist. The reasons for such behavior are not clear at present. More recently, Nedderman and Shearer (Nla) have carried out similar studies over a wider range of gas and liquid flow rates. Although the results were similar in many respects, it seems that the wave frequencies, of the large disturbance waves in particular, are dependent on the geometry of the apparatus. These results showed that, at constant water flow rate, the wave velocity for upward cocurrent flow varied with the square root of the air velocity relative to the waves. 

A difficulty with the above scheme is that measurements carried out with various actual gases that approach ideal behavior will lead to slightly dilferent results. A better absolute standard is provided by the so-called triple point of water. As we shall see later, the coexistence conditions of water in the solid, liquid, and vapor state can occur only under a set of precisely controlled, invariant conditions determined by the physical characteristics of H2O. These conditions are completely reproducible all over the world. For consistency with the above absolute temperature scheme the triple point of water is assigned a temperature T (triple point of H2O) = 273.16 K = 7). Then any other absolute temperature is determined through the proportionality T = (P/Pt) 273.16, where P is the pressure at T and Pt is the pressure measured for He in equilibrium with water at its triple point. 

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