Flow time efficiency

Flow time efficiency is the ratio of the theoretical flow time to the actual average flow time. Low values for flow time efficiency indicate that a large fraction of time is spent waiting. 

The riffles plates will be subjected to wear and over time could affect flow splitting efficiency. 

In reversed-phase HPLC, column temperature is a strong determinant of retention time and also affects column selectivity. A column oven is therefore required for most automated pharmaceutical assays to improve retention time precision, typically at temperatures of 30-50°C. Temperatures >60°C are atypical due to concerns about thermal degradation of the analytes and column lifetimes. Exceptions are found in high-throughput screening where higher temperatures are used to increase flow and efficiency. Ambient or snb-ambient operation is sometimes found in chiral separations to enhance selectivity. Column ovens... 

Applications of LC-NMR are still scarce but the technique will become more widely used. The main effort for efficient exploitation of LC-NMR needs to be made on the chromatographic side, where strategies involving efficient preconcentration, high loading, stop-flow, time slicing, or low flow procedures have to be developed. Microbore columns or capillary separation methods, such as capillary LC-NMR, CE-NMR, and CEC-NMR, will find increased application, one reason being that the low solvent consumption will allow the use of fully deuterated solvents. 

Process ability Surface area, surface free energy, crystal defects, and deformation potential affect compressibility and machineability on high-speed tableting machines with reduced compression dwell times Particle size distribution and shape affect flow properties, efficiency of dry mixing process, and segregation potential Compressibility, flow ability, and dilution potential affect the choice of direct compression as a manufacturing process... 

Despite the experience with batch reactors it may be worthwhile to operate continuous reactors also for fine chemicals. Continuously operated reactors only demand for one start-up and one shut-down during the production series for one product. This increases the operating time efficiency and prevents the deactivation of dry catalysts this implies that the reactor volume can be much smaller than for batch reactors. As to the reactor type for three phase systems an agitated slurry tank reactor [5,6] is not advisable, because of the good mixing characteristics. Specially for consecutive reaction systems the yields to desired products and selectivities will be considerably lower than in plug flow type reactor. The cocurrent down flow trickle flow reactor... 

The recovery of acidic oils via an Emulsification and Coalescence mechanism is very similar to the recovery of nonacidic oils by petroleum sulfonate solutions (6). Although high coalescence rates are prerequisites to the success of both systems, the recovery efficiencies of alkaline-acidic systems appear to be inversely related to the rate of coalescence. It is speculated that the relaxation time for coalescence must be greater than the flow time required for the contacting of adjacent ganglia of residual oil which have been mobilized by emulsification and wettability alteration processes. Yet coalescence was a necessary condition for enhanced recoveries since systems (such as hydroxides with univalent cations) in which the emulsion phase flocculated into the original oil volume did not improve the recovery efficiency. Some reduction in interfacial tension (10 " -100 dynes/cm) is required for the emulsification step although ultralow tension (10 -10 dynes/cm) was not necessary to the alkaline recovery processes. This observation concurs with an identical result of Schechter and coworkers (6). The two steps to this recovery mechanism. Emulsification and Coa,lescence, appear to be necessary and sufficient conditions for the enhanced production and recovery of nonacidic (6) and acidic oils. 

The first characteristic time of interest for this reactor analysis will serve as a basis to describe the reactor efficiency. This reference time must be carefully chosen as a function of the type of reactor under consideration. As detailed below, this reference time could be also denoted flow time , convection time or residence time to enforce its physical meaning. Nevertheless, to avoid some confusion, it will be called reference time in the present chapter. 

Technological progress determines the characteristics of flows in supply chains. It influences flow time, quality, cost, effectiveness and efficiency. The computerisation and automation of operation is the most dynamic economic trend. Labour costs in supply chains, in particular in high-tech sectors, are more often generated by intellectual and social capital than by the actual labour force. The trend described above is demonstrated by the improvement of operational indicators of supply chains such as production efficiency, delivery time, production and distribution waste and process quality. It seems obvious that in the foreseeable future those supply chains that do not use modern solutions will be less competitive or will, following a survival strategy, search for other sources of competitive advantage. 

Mineral fillers were subjected to the oxygen plasma treatment during various time. Efficiency of process gas flow was 20 cmVmin, and the pressure in the reactor chamber was maintain at 30 Pa. Symbols of the modified fillers are as follows ... 

The fixed ion resin technique, in particular Ca and Ag " forms of resin, is replacing traditional GPC for routine corn syrup analysis in the food industry. The major drawback of these columns includes the compressibility of the gel matrix, extended analysis time, efficiency losses of the order of 50% for a doubling of the flow-rate, the need for high temperature (850 operation, and the need for specialized regeneration and re-packing of contaminated columns. However these drawbacks are offset by the ability to obtain an almost total analysis of material applied to the column and the use of water as the only eluant. 

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