Demand conditions

Olefin Feedstock Selection. The selection of feedstock and severity of the cracking process are economic choices, given that the specific plant has flexibiUty to accommodate alternative feedstocks. The feedstock prices are driven primarily by energy markets and secondarily by supply and demand conditions ia the olefins feedstock markets. The prices of iadividual feedstocks vary widely from time to time as shown ia Figure 2, which presents quarterly prices of the various feedstocks ia the United States from 1978 through 1991 ia dollars per metric ton (1000 kg) (4). 

Interruptibles As outlined in Section 19.1.4, some users are offered interruptible contracts. A condition of these is that the user must provide a standby fuel and that, when requested, he or she must switch to this fuel. Under peak demand conditions, the large quantity of gas that would be burnt (typically, for steam raising) is available for use by firm contract and tariff users. 

The relatively high cost and lack of domestic supply of noble metals has spurred considerable efforts toward the development of nonnoble metal catalysts for automobile exhaust control. A very large number of base metal oxides and mixtures of oxides have been considered, especially the transition metals, such as copper, chromium, nickel, manganese, cobalt vanadium, and iron. Particularly prominent are the copper chromites, which are mixtures of the oxides of copper and chromium, with various promoters added. These materials are active in the oxidation of CO and hydrocarbons, as well as in the reduction of NO in the presence of CO (55-59). Rare earth oxides, such as lanthanum cobaltate and lanthanum lead manganite with Perovskite structure, have been investigated for CO oxidation, but have not been tested and shown to be sufficiently active under realistic and demanding conditions (60-63). Hopcalities are out-... 

Clavilier J. 1987. Pulsed linear sweep voltammetry with pulses of constant level in a potential scale, a polarization demanding condition in the study of platinum single crystal electrodes. J Electroanal Chem 236 87-94. 

Furthermore, concentrates may also be used as conventional additives in the same polymer or in different polymers. In this way a substantive antioxidant (or modifier) system can be produced with very high effectiveness especially under aggressive environments. In comparison, under such demanding conditions, conventional antioxidants will not only lead to premature failure of the polymer but also to dangerous situations such as in the case in food contact application (packaging), medical uses of polymers (artificial joints), and failure of aircraft tyres where human lifes are at risk. 

The optimal sensitizer for the dye-sensitized solar cell should be panchromatic, i.e., it should absorb visible light of all colors. Ideally, all photons at wavelengths shorter than a threshold of about 920 nm (see Section 9.16.1.1) should be harvested and converted to electric current.1,2 In addition, the sensitizer should fulfill several other demanding conditions ... 

Peduoropolyethers, which constitute special class of fluoropolymer, are useful as lubricants,1 elastomers,2 and heat-transfer fluids under demanding conditions. Several commerical products are available, which are generally prepared by ring-opening polymerization of hexafluoropropylene oxide or by the random copolymerization oftetrafluoroethylene and hexafluoropropylene with oxygen under ultraviolet irradiation.3 Direct fluorination of hydrocarbon ethers has been reported4 but must be done very slowly under carefully controlled... 

The advantage of this protocol over the direct lithiation method is that the lithiated glycal was produced under less demanding conditions. However, the first lithiation step is not avoided and thence the acidity related restrictions to protecting groups will still apply. In this context, Beau devised a route to 1-stannyl glycals based on a radical-mediated... 

Starting from longer-chain olefins means high boiling points of the products, and hence distillation at higher temperatures and vacuum. These demanding conditions cannot be met by the modern rhodium-catalyzed processes. 

Kumari et al, (2003) 12 2 mg nicotine, subcutaneously N-Back Nicotine improved accuracy in all N-back conditions and reduced response times during the more demanding conditions of the task. Irrespective of drug condition, frontal and parietal regions were activated with increasing memory load. Nicotine, however, increased brain activation in the anterior cingulate (0-back, 1-back, 2-back), superior frontal (1-back, 2-back), and left superior parietal cortex (1-back, 2-back, 3-back), in the 3-back condition, nicotine reduced activation in the right superior parietal cortex. 

An additional important differentiation is required eoneeming the ehanging demand conditions on the markets, such as for example the shift away from mass production to a diversified quahty production. 

Chlorolysis of the corresponding disulfanes is a favorable procedure for the preparation of aliphatic, aromatic, and heterocyclic sulfenyl chlorides under not too demanding conditions [low temperature mild chlorinating agents, such as SO2CI2 14) or CH3SCI3 (15)]. Perfluorinated sulfenyl chlorides can also be prepared by this procedure in special cases a mixture of CF3SSCF3 and chlorine reacts in a Pyrex Carius tube imder UV irradiation to form sulfenyl chloride in an equilibrium reaction 84) ... 

Free radical polymerization remains the most versatile technique due to its compatibility with a wide range of monomers, its compatibility with protic and aqueous media, and experimentally less demanding conditions. Development of... 

Studies on the noradrenergic axis in nonhuman primates provide evidence that early environmental stressors may provoke biological and behavioral phenocopies of human clinical anxiety states. We have used the primate model of developmental psychopathology pioneered by Rosenblum et al. (1991) to explore this issue. Nonhuman primates who were reared as infants by mothers undergoing environmental stress induced by unpredictable or variable foraging demand (VFD-reared) conditions were compared with nonhuman primates reared as infants by mothers exposed to predictable (either low [LFD-reared] or high [HFD-reared]) foraging demand conditions. 

Whereas large charging current contributions are found only under fairly demanding conditions (low analyte concentrations, very high v), ohmic distortions (iR losses) are almost always present. A full chapter in this book is devoted to... 

It should be borne in mind, however, that some of the products formed in stress tests may not be formed under the less demanding conditions of confirmatory tests. In the case of highly photoreactive materials, exposure may be progressively reduced and the study terminated when extensive degradation (e.g., 5-30% degradation) still results. On the other hand, studies... 

Schuth, F., High-throughput screening under demanding conditions Cu/ZnO catalysts in high pressure methanol synthesis as an example, J. Catal. 2003, 216, 110-119. 

Destruction of N20 can be carried out at lower temperatures by adding a reductant. In this case an iron-containing zeolite catalyst is used for the selective catalytic reduction of N20 using hydrocarbons as a reductant. The catalyst did not deactivate in a 2000-hour test under demanding conditions (450°C, 6% H20). Hydrocarbons such as propane (or LPG) and methane (widely available as natural gas) can be used as the reducing agent221. 

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