Carbonate parameters

The carbon parameters ac and /3cc are normally just denoted a and (3, and are rarely assigned numerical values. Simple Hiickel theory thus only considers the connectivity of the TT-atoms, there is no information about the molecular geometry entering the calculation (e.g. whether some bonds are shorter or longer than others, or differences in bond angles). 

Malcolm, R.L. and Leenheer, J.A., The usefulness of organic carbon parameters in water quality investigations, in Proc. Inst. Env. Sciences 1973 Annual Meeting, Anaheim, CA, April 1973, 1-6, pp. 336-340. 

Figure 8-5 plots the carbonate parameters in the steady state as a function of depth between 0 and 400 centimeters. The figure shows that the saturation index, dissolution rate, and respiration rate all are very close to zero at 400 centimeters. The results for this simulation therefore do not depend on the total thickness of the sedimentary column, provided that this total thickness exceeds 400 centimeters, a limit that depends on the rate at which respiration decreases with increasing depth. 

The structure of 14, 15 -dihydropycnanthine has been revised to [533] from a comparison of its 13C NMR spectrum with that of villalstonine [530] and of vindolinine [439]. That [533] belongs to the 19 S series is shown by the similarity of its 18 -proton and carbon parameters to those in 19 -epivindolinine [534] (compare values in vindolinine [535]). The similarity of C(21 ) shifts in 19 -epivindolinine and in 14, 15 -dihydropycnanthine shows the absence of the endocyclic homoallyl effect. (319)... 

Fig. 13. Cluster analysis of a batch of 64 acoustic emissions obtained from a stressed sample of polypropylene + 40% calcium carbonate. Parameters maximum amplitude, variance, and median frequency. The bounds of each cluster are indicated in the mapped projection...

Comparison of carbonate parameters computed by WATEQF in Seawater Test Case... 

Pyrolysis. All of the Texas lignite pyrolysis data reported in the literature have been based on slow pyrolysis rates (e.g., 3-10 C/min). Goodman et al. (20) performed an early study (1958> on the effect of final carbonization temperature on the yields from several lignites, one of which was a Wilcox lignite. More recently Edgar et al. (21) reported a series of atmospheric pressure studies to evaluate the effects of other carbonization parameters (heating rate, particle size) on carbonization yield and decomposition rate. 

The results in the literature for most of the polymers show that, at atmospheric pressure, the pyrolysis temperature does not have to exceed 600°C to reach total carbonization. Parameters such as heating rate and residence time will differ among different authors and some discrepancies still exist for the individual polymers. On the other hand, for polymer mixtures, interaction between polymers appears during pyrolysis between polymers with more gas produced and a better quality of the oils. These interactions are not yet explained. 

Hiscock, W. T., MiUero, F. J. (2005). Nutrient and carbon parameters during the Southern Ocean Iron Experiment (SOFeX). Deep-Sea Res. 152, 2086-2108. 

Table I summarises the average data observed for two major carbonization parameters, the mass yield and the fixed carbon content of charcoal. A highly significant effect of temperature was observed, as well as a significant effect of the residence time and a significant interaction between these two factors. The effect of heating rate was not significant.

There is more shock data available on chlorocarbons than the fluorocarbons. This allows for more extensive testing of the validity of the present model. We note that Dremov and Modestov[53] have reported effective exponential-6 parameters for chlorinated methanes. We find their parameters to be inaccurate when used within the current modeling framework, which uses the recently developed HMSA/MC equation of state[22], and a product set including hydrocarbons and condensed carbon. Parameters for fluid CCL were matched to the shock Hugoniot of liquid CCI4. 

The ECS is one of the largest continental shelves in the world and has high primary production all year round, as observed on the Coastal Zone Color Scanner images. As a transition zone between the Asian continent and the open ocean, this shelf sea is a very active site of carbon cycling. Some measurements of the partial pressure of CO2 (FCO2) nd other carbon parameters have been conducted by other studies since the 1990s primarily in the central and southern part of the ECS. 

In this contribution, it was also recognized that a clear dividing line exists between aromatic and antiaromatic species, set to about a Hiickel hardness of -0.2/3, where /3 is the carbon parameter of Hiickel theory. The Hiickel and relative Hiickel hardness of benzene are. e.g., equal to —1.0/3 and —0.428/3, respectively, those of cyclobutadiene are 0/3 and 0.765/3, respectively. For comparison, the values for Ceo are -0.378/3 and -0.316/3, predicting this molecule to be aromatic. ... 

It is possible to extend the simple Hiickel method to hetero-atom cases in organic pi-electron systems by adjusting the a and 3 values in terms of the basic carbon parameters. Two additional parameters are introduced as ax = ac + hx c-c and Pc-x = c-xPc-c (Table 16.1). 

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