Reduced efficiency

Short-term exposure. This is the maximum concentration to which workers can be exposed for a period of up to 15 minutes continuously without suffering from (a) intolerable irritation, (b) chronic or irreversible tissue change, or (c) narcosis of sufficient degree to increase accident proneness, impair self-rescue, or materially reduce efficiency, provided that no more than four excursions per day are permitted, with at least 60 minutes between exposure periods, and provided the daily time-weighted value is not exceeded. 

For many electronic and electrical appHcations, electrically conductive resias are required. Most polymeric resias exhibit high levels of electrical resistivity. Conductivity can be improved, however, by the judicious use of fillers eg, in epoxy, silver (in either flake or powdered form) is used as a filler. Sometimes other fillers such as copper are also used, but result in reduced efficiency. The popularity of silver is due to the absence of the oxide layer formation, which imparts electrical insulating characteristics. Consequently, metallic fibers such as aluminum are rarely considered for this appHcation. 

New units can be ordered having dry, low NO burners that can reduce NO emissions below 25 ppm on gaseous fuels in many cases, without back-end flue-gas cleanup or front-end controls, such as steam or water injection which can reduce efficiency. Similar in concept to low NO burners used in boilers, dry low NO gas turbine burners aim to reduce peak combustion temperatures through staged combustion and/or improved fuel—air mixing. 

FIG, 5-22 Thermal perfo rmance of weU-stirred fiirnace chambers reduced efficiency as a function of reduced firing density D and reduced sink temperature Tj. (a) Radiant section, oil tube stills, cracking cods, (h) Domestic boiler combustion chambers, (c) Open-hearth furnaces, (d) Soaking pits. 

Reduced-speed operation reduces efficiency. Efficiency is approximately equal to speed expressed as a percentage of synchronous speed. Thus at 75 percent speed, about three-fourths of the motor... 

Conversely, letting the vendor design his exhaust end to the lower value will cause him to grossly oversize, at extra cost and ultimately at reduced efficiency during the normal period. 

Lynch, A.J., T. C. Rao, T.C., "Influence of Hydrocyclone Diameter on Reduced Efficiency Curves," International Journal of Mineral Processing, 1, 173 (1974)... 

It has also been demonstrated that the germicidal effectiveness of free and combined chlorine is markedly diminished with decreasing water temperature. In any situation in which the effects of lowered temperature and high pH value are combined, reduced efficiency of free chlorine and chloramines is marked. These factors directly affect the exposure time needed to achieve satisfactory disinfection. Under the most ideal conditions, the contact time needed with free available chlorine may only be on the order of a few minutes combined available chlorine under the same conditions might require hours. 

With soft gels, column packing has often been plagued with such problems as inferior reproducibility and excessive time requirements. These problems are alleviated with physically stable Toyopearl HW media. However, an improperly packed column can have significantly reduced efficiency. The two key variables for the successful packing of Toyopearl HW media, packing velocity and column size, have been evaluated to determine the optimal packing conditions. 

Optimum flowrates are higher in packed column SFC than in LC. Flowrates as high as 5.0 mL min generally do not dramatically reduce efficiency in SFC [12]. Bier-manns and co-workers reported the separation of (3-blockers at a flowrate of 4.0 mL miiT a rate eight times higher than the flowrate recommended for LC [56]. No deterioration of column performance was observed. 

This is not a good tray design, but it should operate. However, a reduced efficiency is to be expected due to low vapor velocities. 

In piston-type compressors, the oil serves three functions in addition to the main one of lubricating the bearings and cylinders. It helps to seal the fine clearances around piston rings, piston rods and valves, and thus minimizes blow-by of air (which reduces efficiency and can cause overheating). It contributes to cooling by dissipating heat to the walls of the crankcase and it prevents corrosion that would otherwise be caused by moisture condensing from the compressed air. 

Coleman et al. have performed a preliminary structure/activity study for a series of analogues of 77 [149]. They found that removal of the naphthoate moiety (88 Scheme 11.11) dramatically reduced the yield of DNA alkylation, while replacement of the NH2 group with O-benzyl (89 and 90) abolished DNA alkylation completely. Compound 91 alkylated DNA with reduced efficiency, so this effect is not simply due to a requirement for a hydrogen bond donor at this position. Perhaps the amide is required at this position to increase the ability of the C=0 to act as a hydrogen bond acceptor. Importantly, they found a strong correlation between the extent of in vitro DNA alkylation and cell culture cytotoxicity. 

Defunct or poorly operating traps allow heat-containing condensate, insulating air, and corrosive gases to accumulate within the condensate return system, thus reducing efficiency and greatly increasing the risks of system deterioration. 

Most of these claims are spurious. In the presence of hard water and the absence of adequate condensate return, no matter how small the boiler, the elements quickly scale up, reducing efficiency and life-span. These boilers may fail in service well before a scheduled acid clean or element replacement service occurs. In addition, regular acid cleaning on small boilers can be risky and is not recommended. 

The demand for alkali, phosphate, and/or polymer internal chemical treatments becomes significant, and unless extremely good control over BW chemistry and boiler plant operations is provided, the result most likely will be a scaled boiler, higher fuel costs, and reduced efficiency. A softener is required under these circumstances. 

The drawback is that the precipitation chemistry results in suspended solids that must be fluidized and removed from the boiler by BD, so a polymeric sludge conditioner (dispersant, deposit control agent) product and additional BD is required. The higher the FW hardness, the more BD is required because of the buildup of suspended solids, so there is a trade-off in terms of operating with lower quality FW and the resulting reduced efficiency. 

Typically, online cleaning must be carried out fairly slowly and carefully, so that the programs may take 3 to 6 months, perhaps longer, before particularly satisfactory results are achieved. If the boiler is particularly dirty before an online clean is considered necessary, then the combustion efficiency will be lower than desirable. It consequently will take some time before this reduced efficiency improves significantly, and therefore there is an additional fuel cost that must be considered, as well as the cost of the online cleaning program. 

We should also compare the scope of the technologies for different waste streams. With the exception of Brocat which only handles HBr, the systems can be used with HBr or metal salt streams. However, H2O2 has an advantage in terms of handling impurities in the steam such as low levels of organics. Chlorine and chlorate will suffer from reduced efficiency due to side reactions Brocat has potential problems with catalyst poisoning. H2O2 suffers no major drawbacks in this respect. 

As indicated in Fig. 1, nitrogenase can reduce substrates other than Na. In the absence of other reducible substrates it will reduce protons to dihydrogen, but it can also reduce a number of other small triple-bonded substrates, as indicated in Section V,E,1. Large substrates are not reduced efficiently, indicating physical limitations on access to the enzyme s active site. CO is a potent inhibitor of all nitrogenase substrate reductions except that of the proton to Ha. In the presence of CO the rate of electron transfer is generally not inhibited, but all electrons go toward the production of Ha. 

The same applies to pathologically-disturbed function. A simulated reduction in coronary blood flow (heart attack) would lead to reduced oxygen supply to the cells in the virtual heart, which would reduce efficiency of cardiac contraction and possibly give rise to heart rhythm disturbances. Ventricular pressure development would be compromised, as would the blood supply to all organs of the body, including the heart. All these implications can be studied in a virtual heart. 

Catalytic hydrogenation transfers the elements of molecular hydrogen through a series of complexes and intermediates. Diimide, HN=NH, an unstable hydrogen donor that can be generated in situ, finds specialized application in the reduction of carbon-carbon double bonds. Simple alkenes are reduced efficiently by diimide, but other easily reduced functional groups, such as nitro and cyano are unaffected. The mechanism of the reaction is pictured as a concerted transfer of hydrogen via a nonpolar cyclic TS. 

Berthod, A., Causes and remediation of reduced efficiency in micellar liquid chromatography, /. Chromatogr. A, 780, 191, 1997. 

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