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Efficiency general

The wisest fan choice is frequently not the cheapest fan. A small fan operates well on its curve but may not have adequate capacity for maximum flow control, future needs, or process upset conditions. It may be so lightly constmcted that it is operating near its peak speed with no provision for speed increases in the future, if needed. As fan size is increased, efficiency generally improves and wheel speed is lower. These factors decrease operating cost and provide reserve capacity for the future. However, it is also possible to oversize a fan and impair its performance. [Pg.106]

An efficient general synthesis of a-chiral (Z)- and (H)-a1kenes ia high enantiomeric purity is based on the hydroboration of alkynes and 1-bromoaIkynes, respectively, with enantiomericaHy pure IpcR BH readily available by the hydroboration of prochiral alkenes with monoisopiaocampheylborane, followed by crystallization (519). [Pg.324]

High efficiency, generally low pressure drop, well suited for distillation of clean systems, very low HETR... [Pg.86]

The collection efficiency of cyclones varies as a function of particle size and cyclone design. Cyclone efficiency generally increases with (1) particle size and/or density, (2) inlet duct velocity, (3) cyclone body length, (4) number of gas revolutions in the cyclone, (5) ratio of cyclone body diameter to gas exit diameter, (6) dust loading, and (7) smoothness of the cyclone inner wall. Cyclone efficiency will decrease with increases in (1) gas viscosity, (2) body diameter, (3) gas exit diameter, (4) gas inlet duct area, and (5) gas density. A common factor contributing to decreased control efficiencies in cyclones is leakage of air into the dust outlet (EPA, 1998). [Pg.400]

Fig. 5.2 shows that for the single-step cooled CBT plant at a given combustion temperature, the overall efficiency of the cooled gas turbine efficiency increases with pressure ratio initially but, compared with an uncooled cycle, reaches a maximum at a lower optimum pressure ratio. Fig. 5.3 shows that for a given pressure ratio the efficiency generally increases with the combustion temperature even though the required cooling fraction increases. [Pg.75]

The power developed on the crankshaft is further depreciated by the requirements of such accessories as the electric alternator, power steering pump, and air conditioner. The drivetrain that connects the crankshaft output to the vehicle drive wheels causes a further loss in power. Drivetrain efficiency generally falls within 80 to 95 percent. The remaining useful propulsive power varies with speed. [Pg.101]

Note that these values for theoretical trays do contain corrections in overall efficiency, and hence are not the actual trays for the binary distillation column. Efficiencies generally run 50-60% for systems of this type which will yield a column of actual trays almost twice the theoretical at the operating reflux. [Pg.40]

Totrov, M. Accurate and efficient generalized Bom model based on solvent accessibility derivation and application for logP octanol/water prediction and flexible peptide docking, f Comput. Chem. 2004, 25, 609-619. [Pg.403]

A further consideration when combining databases from multiple suppliers is how to identify and deal with redundant compounds. Here, some method of mapping multiple supplier information onto a single compound is needed for efficiency. Generally, all information can be mapped, although some consideration of cost and supplier reliability may allow a hierarchy of supplier information to be applied. [Pg.92]

After obtaining from the measured value of kl by this procedure, one can determine the attachment efficiency in the quasi-free state, rj = fe1f/fed.ff, by the same procedure as for scavenging reactions (see Eq. 10.11 et seq.). Mozumder (1996) classifies the attachment reactions somewhat arbitrarily as nearly diffusion-controlled, partially diffusion-controlled, and not diffusion-controlled depending on whether the efficiency p > 0.5, 0.5 > r > 0.2, or r < 0.2, respectively. By this criterion, the attachment reaction efficiency generally falls with electron mobility. Nearly diffusion-controlled reactions can only be seen in the liquids of the lowest mobility. Typical values of r] are (1) 0.65 and 0.72 respectively for styrene and p-C6H4F2 in n-hexane (2) 0.14 and 0.053 respectively for a-methylstyrene and naphthalene in isooctane (3) 1.8 X 10-3 for C02 in neopentane and (4) 0.043 and 0.024 respectively for triphenylene and naphthalene in TMS. [Pg.357]

The excellent reducing properties of potassium tetracarbonylhydrido-ferrate have been used to good effect in providing an efficient general piperidine synthesis from alkyl and aryl amines and glutaraldehyde210 (Scheme 138). The reaction probably proceeds via reduction of intermediate Schiff bases and cyclization via the iminium salt. [Pg.381]

Reaction of Indole-3-acetonitriIe with 6 A New Efficient General Method for the Synthesis of 1,2- Substituted and Condensed Carbazoles (Type-V, 5a Model)... [Pg.10]

Related catalytic enantioselective processes It is worthy of note that the powerful Ti-catalyzed asymmetric epoxidation procedure of Sharpless [27] is often used in the preparation of optically pure acyclic allylic alcohols through the catalytic kinetic resolution of easily accessible racemic mixtures [28]. When the catalytic epoxidation is applied to cyclic allylic substrates, reaction rates are retarded and lower levels of enantioselectivity are observed. Ru-catalyzed asymmetric hydrogenation has been employed by Noyori to effect the resolution of five- and six-membered allylic carbinols [29] in this instance, as with the Ti-catalyzed procedure, the presence of an unprotected hydroxyl function is required. Perhaps the most efficient general procedure for the enantioselective synthesis of this class of cyclic allylic ethers is that recently developed by Trost and co-workers, involving Pd-catalyzed asymmetric additions of alkoxides to allylic esters [30]. [Pg.194]

Highly-efficient general acid catalysis of acetal hydrolysis is involved in the reactions of glycosidase enzymes such as lysozyme (Dunn and Bruice, 1973)... [Pg.196]

This method is relatively inexpensive and easy to apply, although there is no commercially available kit. However, recently succinimidyl-HYNIC became commercially available (Solulink, Inc., San Diego, California, U.S.). Liposomes are labeled rapidly and with a labeling efficiency generally higher... [Pg.180]

Intramolecular general base catalysis of hycholysis (21a) was unexpected since the ester has a phenolic leaving group. Felton and Bruice (1968, 1969) reasoned that, if nucleophilic attack occurred, the leaving phenolate ion group would be properly positioned to attack the intermediate acylimidazole and thereby reverse the reaction. The normally less efficient general base reaction then becomes the favoured pathway, as in hydrolysis of acetyl salicylate (see Section 4). Likewise, Fife and McMahon (1970) explained bimolecular general base catalysis by imidazole (21b) in hydrolysis of o-(4-nitrophenylene) carbonate 3 49) by reversibility... [Pg.32]

In 1974 Midwest Research Institute operated a pilot-scale multiple chamber incinerator to evaluate for EPA the operational variables for pesticide incineration (8). The system included a. pilot-scale incinerator, a three-stage scrubber system, and a scrubber water treatment system. Nine pesticides (aldrin, atrazine, captan, DDT, malathion, mirex, picloram, toxaphene, and zineb) in 15 liquid and solid formulations were studied. Destruction efficiencies generally exceeded 99.99% over a range of temperatures and retention times ( 950 to 1100°C, 1.2 to 6 s, and 80 to 160% excess air). This study also documented the generation of measurable quantities of cyanide in the incinerator off-gas during the incineration of organonitrogen pesticides. [Pg.184]

Tronrud, D. E., Ten Eyck, L. F. and Matthews, B. W. (1987). An efficient general-purpose least-squares refinement program for macromolecular structures. Acta Crystallogr. A 43,489-501. [Pg.172]

Michel, J., Taylor, R.D., Essex, J.W. Efficient generalized born models for Monte Carlo simulations. J. Chem. Theory Comput. 2006, 2, 732-9. [Pg.72]

The reaction sequence, which involves the conversion of the phenolic hydroxyl groups to a phenyltetrazolyl ether (see Note 6) followed by reduction to effect removal of the phenolic hydroxyl group, illustrates a mild, efficient, general, and convenient procedure. It has been applied successfully by the submitters2 to a variety of substituted phenols, as shown in Table I. [Pg.43]

Product inhibition and substrate inhibition are effects also known in enzyme catalysis that can reduce catalytic efficiency. Generally, catalytic systems (natural or artificial) based on covalent interactions are more sensitive towards inhibitions than non-covalent systems utilizing weak interactions Garcia-Junceda, E. (2008) Multi-Step Enzyme Catalysis, Wiley-VCH Verlag GmbH, Weinheim, Germany. [Pg.337]

A highly efficient, general method to produce aromatic acids is via the liquid phase reaction of methylaromatic compounds with dioxygen ... [Pg.81]


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See also in sourсe #XX -- [ Pg.11 , Pg.47 ]




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A Few More General Topics Thermodynamic Efficiency

Catalysts, general efficiency

Chromatography, general column efficiency

Efficiency and General Fertiliser Practice

Efficient Intramolecular General Acid-Base Catalysis

General aspects Flow regimes, liquid holdup, two-phase pressure drop, and wetting efficiency

General current efficiency

Separation efficiency, general theory

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