Key factors

The solutions we offer are based on two main technologies electrolytic silver recovery from fixer solutions and cascade fixing. In what follows we will give more teclmical details about these teclmologies. We will clarify the key-factors to obtain reliable and more ecological solutions for the silver in the rinsing water. 

The key question we want to answer is what are the intrinsic sequence dependent factors tliat not only detennine tire folding rates but also tire stability of tire native state It turns out tliat many of tire global aspects of tire folding kinetics of proteins can be understood in tenns of tire equilibrium transition temperatures. In particular, we will show tliat tire key factor tliat governs tire foldability of sequences is tire single parameter... 

A key factor in obtaining binding support for aquaculture is development of a sound business plan. The plan needs to demonstrate that the prospective culturist has identified all costs associated with estabhshment of the faciUty and its day-to-day operation. One or more suitable sites should have been identified and the species to be cultured selected before the business plan is submitted. Cost estimates should be verifiable. Having actual bids for a specific task at a specific location eg, pond constmction, well drilling, building constmction, and vehicle costs helps strengthen the business plan. 

Capital and operating costs for soda ash production are extremely site specific (29,10). Key factors iaclude iafrastmcture development, freight to consumers, local energy and labor costs, and by-product saleabiUty. 1990 Hst price of bulk natural soda ash was 108/t, F.O.B. Wyoming. 

Bulk Density. Bulk density, or the apparent density, refers to the total amount of space or volume occupied by a given mass of dry powder. It includes the volume taken up by the filler particles themselves and the void volume between the particles. A functional property of fillers in one sense, bulk density is also a key factor in the economics of shipping and storing fillers. 

The development of a suitable solvent system is important for successful operation. Solvent systems generally consist of at least the following components extractant, diluent, inorganic salts or acids, and water. The relative optimization of these components yields the best conditions with which to achieve separation. A key factor to success is the choice of the appropriate extractant. Many extractants may be used for REE separation. These may be divided into three groups on the basis of the mechanisms involved. These extractants are tisted in Table 7. 

A key factor determining the performance of ultrafiltration membranes is concentration polarization due to macromolecules retained at the membrane surface. In ultrafiltration, both solvent and macromolecules are carried to the membrane surface by the solution permeating the membrane. Because only the solvent and small solutes permeate the membrane, macromolecular solutes accumulate at the membrane surface. The rate at which the rejected macromolecules can diffuse away from the membrane surface into the bulk solution is relatively low. This means that the concentration of macromolecules at the surface can increase to the point that a gel layer of rejected macromolecules forms on the membrane surface, becoming a secondary barrier to flow through the membrane. In most ultrafiltration appHcations this secondary barrier is the principal resistance to flow through the membrane and dominates the membrane performance. 

The key factor influencing the varying interpretations is that although there is an enormous volume of petroleum resources in the ground throughout the world, it is found in deposits that differ in quaUty and quantity from country to country. Only a small fraction of these resources are conventional petroleum resources (160.1 x 10 m (1006.8 x 10 bbl)) and are in the category of proved reserves. An additional... 

As can be seen from this analysis, the natural gas feedstock and capital charges amount to over 93% of the total production cost before return on investment. Therefore, energy consumption and capital investment are the key factors in determining ammonia production profitabiUty. 

Scale-Up Principles. Key factors affecting scale-up of reactor performance are nature of reaction zones, specific reaction rates, and mass- and heat-transport rates to and from reaction sites. Where considerable uncertainties exist or large quantities of products are needed for market evaluations, intermediate-sized demonstration units between pilot and industrial plants are usehil. Matching overall fluid flow characteristics within the reactor might determine the operative criteria. Ideally, the smaller reactor acts as a volume segment of the larger one. Elow distributions are not markedly influenced by... 

Additional complications can occur if the mode of deformation of the material in the process differs from that of the measurement method. Most fluid rheology measurements are made under shear. If the material is extended, broken into droplets, or drawn into filaments, the extensional viscosity may be a more appropriate quantity for correlation with performance. This is the case in the parting nip of a roUer in which filamenting paint can cause roUer spatter if the extensional viscosity exceeds certain limits (109). In a number of cases shear stress is the key factor rather than shear rate, and controlled stress measurements are necessary. 

Adhesion Life. A second key factor in determining the durabHity of a sealant is the abHity of the sealant to adhere to the substrate through its lifetime. A sealant may have exceHent resistance to uv effects, but if it has poor adhesion performance and faHs adhesively, it is of Httie use. The same can be said of a sealant with superior adhesion characteristics but poor resistance to uv. Either situation results in a short performance life. 

The commodity nature of the product and the easy access to the Hcensed processes enable new producers, particularly in developing countries, to enter the global styrene merchant market with Htde experience in styrene technology. Access to ethylene, which caimot be easily transported by means other than pipelines, is a key factor in considering new styrene faciHties. Timing, or luck, is even more important because the supply and demand of styrene are seldom in balance and the price fluctuates broadly and rapidly as a result. Most of the time, the producers either suffer losses (1981—1985, 1991—1993) or enjoy handsome profits (1987—1990, 1994—mid-1995). Investments in styrene plants are known to have been recovered in less than a year, but prosperity encourages over-investment and lean years may foUow. 

The actual amount and stmcture of this "bound" water has been the subject of debate (83), but the key factor is that in water, PVP and related polymers are water stmcture organi2ers, which is a lower entropy situation (84). Therefore, it is not unexpected that water would play a significant role in the homopolymeri2ation of VP, because the polymer and its reactive terminus are more rigidly constrained in this solvent and termination k is reduced... 

Thiosemicarba2ones have long been used as antiviral agents, principally against pox vimses of the vaccinia family. One compound of this series, the isatin derivative (6) C HgN OS, has been used prophylacticaHy to prevent outbreaks of smallpox in humans (10) and to inhibit the protein synthesis in poxvims-infected cells. The molecular mechanics relating to this property are still not known (11), though the binding of a metal ion may be a key factor... 

Starches. Starch (qv) granules must be cooked before they wiU release their water-soluble molecules. It is common to speak of solutions of polysaccharides, but in general, they do not form tme solutions because of their molecular sizes and intermolecular interactions rather they form molecular dispersions. The general rheological properties of polysaccharides like the starch polysaccharides are described below under the discussion of polysaccharides as water-soluble gums. Starch use permeates the entire economy because it (com starch in particular) is abundantly available and inexpensive. Another key factor to its widespread use is the fact that it occurs in the form of granules. 

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