Design and Selection Criteria

The efficiency of a screening operation may be evaluated by simple mass balances. Let F be the mass flow rate of feed, O the mass flow rate of coarse fraction, and U the mass flow rate of fines also, let Xp be the coarse mass fraction in the feed, Xq the coarse mass fraction in the overflow and Xy the coarse mass fraction in the underflow. Furthermore, the fines fractions in 

The coarse fraction in the feed must also leave in the two streams, and so 

The effectiveness of a screen is a measure of how well it performs the separation of coarse and fine fractions. If the screen functioned perfectly, all of material O would be in the overflow and all of material U would be in the underflow. A manner of determining screen efficiency would be by calculating the ratio of oversized material O that is actually in the overflow to the amount of material O entering with the feed, that is. 

An overall combined efficiency may be defined as the product of Equations 9.5 and 9.6, and it may be denoted simply as (Foust et al., 1960) 

Equation 9.8 is an alternative expression to evaluate screen efficiency without involving the streams and only using the fractions. 

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The implementation of efficient and updated 2D and 3D structure databases is one major challenge in molecular diversity management. In addition to the compound design and selection criteria used for the compilation, the quality of the compound storage, manipulation, and logistics systems used for the management of the collection are key factors to yield reproducible results. ... 

Konstandopoulos, A. G., Skaperdas, E., Warren, J., and Allanson, R. Optimized filter design and selection criteria for continuously regenerating diesel particulate traps. SAE Technical Paper No. 1999-01-0468 (1999). 

This has proved to be shortsighted, and selection criteria for new sites will almost certainly contain specific guidelines on such things as cap or cover design and type of waste form permitted to be buried. 

J. Wieling, J. Schepers, J. Hempenius, C. K. Mensink, and J. H. G. Jonkman, Optimization of chromatographic selectivity of twelve sulphonamides in reversed-phase HPLC using mixture designs and multi-criteria decision making, J. Chromatogr., 545 101 (1991). 

Protocol The study s rationale, design, subject selection criteria, concomitant medications, visit schedules, and observations and measurements to be made to fulfill the study s objectives (labs, assessments, tests) are discussed with the entire staff conducting the study. 

A useful table of criteria and data for the rapid design and selection of evaporators is available. ... 

The design and selection of measurement endpoints should be based on the following criteria ... 

Candidate polymers for biomedical applications must comply with a variety of requirements characteristic of most biomaterials. These requirements arise either from the specific chemical or physical structure of the polymers (chemical, physical, and mechanical criteria) or from the physiological environment where they will be used (biological criteria). Table I summarizes major criteria for the design and selection of polymers as biomaterials. 

Selection and design deficiencies are probably the most common as well as the most serious causes of problem incineration systems. Reputable incinerator contractors usually make every effort to satisfy specified design and construction criteria and meet their contractual obligations. Operating and maintenance deficiencies can usually be corrected. However, once a system has been installed and started, very little can be done to compensate for fundamental design inadequacies. Major, costly modifications and revisions to performance objectives are usually required. 

By applying MF techniques, the reaction heat can be controlled by varying the thickness and thermal conductivity of the wall. Geometrical parameters and construction materials are the key selection criteria in designing the microreactor systems, whilst for microsystems which perform chemical reactions, separations, analyses, and sensing devices, the channels, cavities, valves and electrodes all need to be designed and selected properly. 

The use of plastics in modern pharmaceutical packaging products is described. Aspects covered include the continual quest for an ideal material and process, properties, machinery and selection criteria (FDA approval, tamper-evident packaging, product-package compatibility, sterilisation, polymer additives, smart design and environmentally-friendly packaging). 

The important criteria for vent design and selection are that the vent should open fully at the designated pressure with very little inertia and should be perfectly sealed when closed. The principles and... 

Rishel, J. B., T. H. Durkin, and B. L. Kincaid. 2006. HVACPump Handbook, 2nd ed. New York McGraw-Hill. Covers all aspects of HVAC pumps and pumping. Includes design basics, selection criteria, installation and operation, performance issues and measures, and the use of pumps in open and closed HVAC cooling systems and in HVAC hot water systems. 

The Spaceship total dry mass at launch shall not exceed [25,000] kg. Minimum module mass is goal and selection criteria for design. High temperature reactor is required to minimize overall mass... 

ISO 9000. The ISO 9000 series of standards was first issued in 1987 and then updated in 1994. The ISO 9000 standard describes the selection criteria for the four standards, ISO 9001—9004. ISO 9001 is composed of 20 items covering manufactured products from design and development in R D to commercial production and after-sale service or technical support. ISO 9002 has 19 of the items in 9001 describing the requirements of a quahty system for the manufacture of an item, such as chemicals, to a specification only the requirement relating to product development is omitted. Chemical companies seldom certify to ISO 9003, which describes the quahty system for a laboratory involved in final inspection and test. Finally, ISO 9004 presents guidelines for total quahty management. 

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