Growth determinants

Along with operating variables of the crystallizer, nucleation and growth determine such crystal characteristics as size distribution, purity, and shape or habit. 

Fig. 4.3. (A) Composite multispecies benthic foraminiferal Mg/Ca records from three deep-sea sites DSDP Site 573, ODP Site 926, and ODP Site 689. (B) Species-adjusted Mg/Ca data. Error bars represent standard deviations of the means where more than one species was present in a sample. The smoothed curve through the data represents a 15% weighted average. (C) Mg temperature record obtained by applying a Mg calibration to the record in (B). Broken line indicates temperatures calculated from the record assuming an ice-free world. Blue areas indicate periods of substantial ice-sheet growth determined from the S 0 record in conjunction with the Mg temperature. (D) Cenozoic composite benthic foraminiferal S 0 record based on Atlantic cores and normalized to Cibicidoides spp. Vertical dashed line indicates probable existence of ice sheets as estimated by (2). 3w, seawater S 0. (E) Estimated variation in 8 0 composition of seawater, a measure of global ice volume, calculated by substituting Mg temperatures and benthic 8 0 data into the 8 0 paleotemperature equation (Lear et al., 2000).

As with selenium analysis, HGAAS also finds a place in Te determination. Basnayake et al. amended cultures of P. fluorescens K27 with 0.1 mM tellurite and, after 92-h growth, determined that approximately 34% of added Te was present as either precipitated, elemental Te in/or on centrifuged cells the balance of added Te remained in solution.190 In this same study, GC/MS was used for determination of DMTe in the same facultative anaerobe amended with tellurate.190 Earlier, GC/MS was used to analyze the headspace of a tellurium-resistant fungus amended with tellurite.215 This last is one of the few reports of the detection of dimethyl ditelluride in microbial headspace (see below). 

The interplay of these two basic rates determines the size of the resulting particles. For instance, the reason that snow flakes reach sizes of several cm at lower latitudes but arrive as extremely small crystals, called diamond dust in Antarctica, is that the nuclei that are formed in a cloud, will grow during their voyage to earth by adsorbing water molecules. Obviously, this growth will be more important in the moist atmosphere at low latitudes than in the extremely dry atmosphere above Antarctica. The same interplay of nucleation and growth determine the size of metal particles that are formed on a support by chemical reduction of adsorbed precursors, such as metal ions. Here... 

Improvement of clinical symptoms, lack of adverse effects periodic complete blood count with differential, routine blood chemistry growth determinations (body weight and height), blood pressure, pulse rate... 

HjO]/[AOT] ratios influenced the equilibrium sizes of CdS particles generated rates of CdS growth, determined in a stopped-flow spectrophotometer, were consistent with the rate-determining intermicellar exchange of solubilizates... 

Hydrocarbon distributions in the Fischer-Tropsch (FT) synthesis on Ru, Co, and Fe catalysts often do not obey simple Flory kinetics. Flory plots are curved and the chain growth parameter a increases with increasing carbon number until it reaches an asymptotic value. a-Olefin/n-paraffin ratios on all three types of catalysts decrease asymptotically to zero as carbon number increases. These data are consistent with diffusion-enhanced readsorption of a-olefins within catalyst particles. Diffusion limitations within liquid-filled catalyst particles slow down the removal of a-olefins. This increases the residence time and the fugacity of a-olefins within catalyst pores, enhances their probability of readsorption and chain initiation, and leads to the formation of heavier and more paraffinic products. Structural catalyst properties, such as pellet size, porosity, and site density, and the kinetics of readsorption, chain termination and growth, determine the extent of a-olefin readsorption within catalyst particles and control FT selectivity. 

Table 4.1. Lesion growth determined 30 min and 2 h after middle cerebral artery occlusion in rats. Tissue alterations are presented as hemispheric lesion areas (HLA) that were assessed at the level of striatum. [Adapted from Kohno et al. (1995b)]...

Tryptic activity measured in vitro with bovine trypsin. Tryptic activity and larval growth reported as percent of control where control equals 100%. Soybean inhibitor was Kunitz inhibitor. Percent relative growth determined by weight gain of S. exigua for 11 days on artificial diet containing the specified phytochemicals. 

Monteiro, S., Ricarra-Rereira, M.A., Teixeira, A.R., Loureiro, V.B., Ferreira, R.B. (2003a). Environmental conditions during vegetative growth determine the major proteins that accumulate in mature grapes. J. Agric. Food Chem., 51, 4046 053... 

Because amounts of vitamin B12 are very low in foods, tissues, and body fluids, bioautography is used before densitometry. A selected strain of Escherichia coli is used as a microorganism for the bioautography. Growth spots are enhanced by the addition of 2,3,5-triphenyltetrazolium chloride, which is converted to the red-colored formazan by E. coli growth. Determination of vitamin B12 in human plasma and erythrocytes was accomplished by one-dimensional bioautography.A... 

Rino, S., Komiya, T., Windley, B.F., Katayama, I., Motoki, A., and Hirata, T., 2004. Major episodic increases of continental crustal growth determined from zircon ages of river sands implications for mantle overturns in the early Precambrian. Phys. Earth Planet. Interior, 146, 369-94. 

Analysis of deposition transients shows that deposition of copper on TiN from 50 mM copper (II) pyrophosphate solution proceeds through instantaneous nucleation of three dimensional hemispherical clusters and diffusion limited growth. Determination of the diffusion coefficient from the current maximum and analysis of the current decay using the Cotrell equation yielded values of 1 x 10 6 to 2 x 10 6 cm2 s, slightly lower than the value for Cu2t ions due to the presence of the pyrophosphate ligand. The potential dependence of inux and t,n suggest that the nucleus density is the only potential dependent parameter. 

Fig. 12-8 Growth inhibition curves of four HDAC inhibitors in MCF7 and normal human dermal fibroblast (NHDF) cell lines. Cells were treated with inhibitor and relative cell growth determined 6 days later.

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