Yield of actives

The devolatilized coal particles are transported to a direct-fired multihearth furnace where they are activated by holding the temperature of the furnace at about 1000°C. Product quaUty is maintained by controlling coal feed rate and bed temperature. As before, dust particles in the furnace off-gas are combusted in an afterburner before discharge of the gas to the atmosphere. Finally, the granular product is screened to provide the desired particle size. A typical yield of activated carbon is about 30—35% by weight based on the raw coal. 

This method represents the most common and traditional application of computational tools to rational drug design. From a list of molecules of known activity, one can establish a 3D-pharmacophore hypothesis that is then transformed into a 3D-search query. This query is then used to search a 3D database for structures that fit the hypothesis within a certain tolerance. If the yield of active molecules is significant, then the query can be used to predict activities on novel compounds. In our situation, the enantiophore is built from the superposition of a list of sample molecules, which are all well separated on a given CSR Hence, the common features of this series of molecules can become a good enantiophore hypothesis for the enantiores-olution on this CSR... 

Currently, graft post-polymerization of monomers in the gaseous phase (2) is the more widely used process because it has at least two basic advantages. First, side processes of homopolymerization are minimized which reduces the consumption of monomers and makes unnecessary additional treatment of the modified materials with solvents. Second, this method is universal and allows the grafting to the surfaces (such as silica) to be carried out with low radiation yields of active sites as compared to the monomers. 

Only the first three methods below give the natural X (-) isomer of THC. The other methods give the racemic produce and consequently their yields of active THC are actually one-half that indicated. 

Dekker et al. [170] have also shown that the steady state experimental data of the extraction and the observed dynamic behavior of the extraction are in good agreement with the model predictions. This model offers the opportunity to predict the effect of changes, both in the process conditions (effect of residence time and mass transfer coefficient) and in the composition of the aqueous and reverse micellar phase (effect of inactivation rate constant and distribution coefficient) on the extraction efficiency. A shorter residence time in the extractors, in combination with an increase in mass transfer rate, will give improvement in the yield of active enzyme in the second aqueous phase and will further reduce the surfactant loss. They have suggested that the use of centrifugal separators or extractors might be valuable in this respect. 

Fraction Total protein (mg) Specific activity (units/mg protein) Yield of activity (%)... 

Although the 1 1 molar ration produced a higher yield of activity, unpublished results obtained in this laboratory have shown that the majority of the activity is lost upon dialysis. This implies that the increase in activity with the 1 1 system was the result of an increase in the yield of low-molecular-weight antioxidants at the possible cost of higher antioxidants. 

Just as certain nitrogenous compounds are known to increase the rate of browning, the results with pyridine indicated that this may also be true for the production of antioxidants. The present study revealed that use of pyridine doubled the yield of activity. No attempts, however, were made to isolate and purify the antioxidative components, and therefore, no conclusion can be made as to whether pyridine was acting merely as a catalyst or if it was involved in producing a different and stronger antioxidant. 

Each of these metrics gives a different insight into the performance of a screening workflow in retrieving active molecules or discarding inactive ones. Jacobsson et al, for example, used accuracy, sensitivity (which they termed the recall ), yield of actives (termed precision of the active class ) and enrichment to characterize the performance of different structure-based virtual screening workflows [60]. 

Among all the equations, the yield of actives [Eq. (4.3)] and the enrichment [Eq. (4.4)] are probably the most often used the first is the hit rate one that would have if the n selected molecules were tested (again) and the second indicates how many times the virtual screening workflow performs better than a random selection in retrieving active compounds. 

Quantititatively, the value of an affinity chromatography step in the purification process is assessed by the purification factor and the recovery or yield of activity. The purification factor is the ratio of the specific activity after the affinity step to that before it, whereas the recovery or activity is the percentage of the initial activity in the sample that is recovered.61 Examples of the use of adenosine monophosphate (AMP) and related... 

For the same reason as above, excess solvent molecules in the cavitation bubble also seriously limit the applicability of many volatile organic solvents as a medium for sonochemical reactions [2,25,26]. In fact, water becomes a unique solvent in many cases, combining its low vapor pressure, high surface tension, and viscosity with a high yield of active radical output in solution. Its higher cavitation threshold results in subsequently higher final temperatures and pressures upon bubble collapse. Most environmental remediation problems deal with aqueous solutions, whereas organic solvents are mostly used in synthesis and polymer modifications processes. 

Although various carbonaceous sources can be used, petroleum cokes were preferred because of their low ash contents and generally higher yields of active carbon. The cokes were obtained from various sources and with widely varying properties. Sulfur contents ranged from 2.0 to 6.0 wt.% metals, primarily nickel and vanadium, from 500 ppm to 5,000 ppm volatile matter, from 11% to 20%. The coke quality within these ranges did not appear to affect active carbon properties. However, somewhat lower active carbon yields were noted with the higher volatile matter cokes (58-62 wt% vs. 

ISHIBASHI K, Fujishima A, Watanabe T, Ha-SHiMOTO K (2000) Quantum Yields of Active Oxidative Species Formed on Ti02 Photocatalyst, J. Photochem. Photobiol. A ... 

Glucosinolinates Modify metabolism of foreign compounds and reduce yield of active carcinogens from procarcinogens... 

One of the most popular descriptors for evaluating VS methods is the yield of actives (Equation 3.1). This descriptor quantifies the probability that one of n selected compounds is active. In other words, it represents the hit rate if all compounds selected by the VS protocol are tested for activity.However, it contains no information about the consistence of the database and the increase of the ratio of active molecules to inactives within a VS compound selection compared to a random compound selection ... 

The chemical polymerization of even a moderately sized protein of a hundred amino acids in the laboratory is extremely laborious, and the yields of active product can often be low to zero (Kent and Parker, 1988). Cells accomplish this task by using an intricate mechanism which involves catalytic machinery composed of proteins, nucleic acids and their complexes, and synthesize polypeptide chains that are composed of hundreds of amino acids. This process is depicted in Fig. 2.4, and is described in the sections below. The basic components of the cellular protein synthesis apparatus, in all known biological systems, are ribosomes, which are aggregate structures containing over fifty distinct proteins, and three distinct molecules of nucleic acid known as ribosomal ribonucleic acid (ribosomal RNA or rRNA). The amino acids are brought to the ribosomes, the assembly bench , by an RNA molecule known appropriately as transfer RNA . Each of the twenty amino acids is specifically coupled to a set of transfer RNAs (discussed below) which catalyze their incorporation into appropriate locations in the linear sequence of polypeptide chains. Several other intracellular proteins known as init iation and elongation factors a re also required for protein synthesis. 

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