Seed rate enhancement

Nonchemical or traditional practices, such as weed seed removal, optimal crop seeding rates, crop selection, enhanced crop competitiveness, crop rotation, and mechanical weed control are all important components of an effective weed management program (458,459). In the context of modern intensive chemical herbicide appHcation, nonchemical practices may even represent an innovative approach to weed management and should receive careful consideration. 

It is common practice to add crystals, called seed crystals, of the desired phase to a synthesis batch to increase the rate of crystallization, and in some cases to direct the outcome toward selected crystalline phases. It is worthwhile to review the literature on this subject to understand what is known of this phenomenon, however, a recent review article [5] and literature publication [64] on this subject are available, which also contain some details on the mechanism of rate enhancement stemming from the use of seed crystals. 

Mirskii and Pirozhkov [66] reported on experiments in which seed crystals were added to normal batch zeoUte synthesis mixtures. In one set of experiments, different amounts of seed crystals of a desired phase (not specifically mentioned, but probably zeoUte NaA) were added to the synthesis mixture, and noted to ehminate the induction time and increase the rate of crystallization. Two additional factors were investigated and reported a) the rate of crystallization increased more with increased amounts of seed crystals added, and b) the rate of crystallization was enhanced more using the same mass of smaller seed crystals than with larger seed crystals. Both of these results were concluded to imply that the rate enhancement was due to the cumulative seed crystal surface area used to assimilate material from the solution. This point was illustrated further by adding seed crystals of one phase to a solution which nominally produced a different zeoHte phase. For example, zeoUte NaP seed crystals were added to a synthesis mixture, which was demonstrated to precipitate zeolite NaX, after about 30 % of the amorphous reagents had already crystalUzed. After two additional hours of crystallization, the absolute amoimt of zeoUte had... 

Therefore, what is known about the crystallization rate enhancement resulting from the use of seed crystals at the current time is that a) nanometer-sized... 

Sesamin has been associated with the reduction of serum and liver lipids (Hirose etal., 1991,1996 Ide etal., 2001 Yasumoto etal., 2001). Hirose etal. (1991) reported that sesamin decreased lymphatic absorption of cholesterol. Sesamin was found to be a promoter of hepatic fatty acid oxidation in rats (Ashakumary et al., 1999). Addition of a 1 1 mixture of sesamin and episesamin to the diet of rats (0.1-0.5% of total diet) promoted mitochondrial and peroxisomal palmitoyl coenzyme A (CoA) oxidation rates in a dose-dependent manner. Rats fed diets containing 0.5% sesamin had 2 fold higher mitochondrial activity and 10 fold higher peroxisomal activity than rats fed non-sesamin diets. Yasumoto et al. (2001) reported similar findings when a 20% sesame seed diet was fed to rats. These authors compared two experimental sesame seed lines (0730 and 0732) with the commercial cultivar Masekin. Both experimental seed lines enhanced mitochondrial and peroxisomal fatty acid oxidation rates, and were more effective than the commercial cultivar at reducing plasma triacylglycerol levels (Yasumoto et al., 2001). A study of the effects of dietary sesamin on the hepatic metabolism of arachidonic and eicosapentaenoic acids in rats showed similar increases in hepatic mitochondrial and peroxisomal fatty acid oxidation (Sawada et al., 2001). 

U. A. Hartwig, C. M. Joseph, and D. A. Phillips, Flavonoids released naturally from alfalfa seeds enhance growth rate of Rhizobinm nteliloti. Plant Phy.siol. 95 191... 

The [Pt(NH3)4](HC03)2 nanofibers are stable under alkaline conditions in which the pH value may vary between 8 and 11. Under acidic condition, however, the precipitates are unstable, and, therefore, the hydrolysis of TEOS can only be performed in alkaline medium. The alkalinity of the solution (optimum of pH 8.5-9) is controlled by the addition of several ml of 0.2 to 0.8 N ammonia solution. In more alkaline solutions the formation of non-structured Si02 particles is enhanced due to the higher rates of hydrolysis of TEOS and condensation, i.e. more Si02 seeds form and grow in the solution without being in contact with the precipitated [Pt(NH3)4](HC03)2 nanofibers. 

Information on particle growth during either a seeded polymerization or during the growth stage of an un-seeded polymerization at different degrees of conversion also could enhance the understanding of the kinetics. In earlier work (4,5) the rate of polymerization, for polystyrene latexes primarily, has been related to the latex particle diameter and the total number of particles in the reactor. It would be useful to obtain kinetic data and develop the kinetic relationships for styrene (S)-butadiene (B) latexes. 

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