Conservation minimum

We have observed that the concentrations of the Petunia steroids varies considerably between horticultural varities of P, hybrida and between various species of this plant (9). Table III shows the approximate content of a number of insect-inhibitory petuniasterones in leaves of certain Petunias that we have examined. In the examples selected, the individual compounds were isolated by HPLC from extracts of anhydrous leaves and their respective amounts represent a very conservative minimum quantity. Weights were converted to concentrations on the fresh basis assuming a water content... 

The probability for a particular electron collision process to occur is expressed in tenns of the corresponding electron-impact cross section n which is a function of the energy of the colliding electron. All inelastic electron collision processes have a minimum energy (tlireshold) below which the process cannot occur for reasons of energy conservation. In plasmas, the electrons are not mono-energetic, but have an energy or velocity distribution,/(v). In those cases, it is often convenient to define a rate coefficient /cfor each two-body collision process ... 

Every iadustry has its owa sease of what a reasoaable royalty might be. Whereas earned royalties are usually based oa aet sales, a very rough rule of thumb is that an earned royalty reflects approximately 25% of profits earned on the particular technology. Minimum royalties are often based on one-fourth to one-thind of a conservative projection of sales. 

Direct and Indirect Energy Gap. The radiative recombination rate is dramatically affected by the nature of the energy gap, E, of the semiconductor. The energy gap is defined as the difference in energy between the minimum of the conduction band and the maximum of the valence band in momentum, k, space. Eor almost all semiconductors, the maximum of the valence band occurs where holes have zero momentum, k = 0. Direct semiconductors possess a conduction band minimum at the same location, k = O T point, where electrons also have zero momentum as shown in Eigure la. Thus radiative transitions that occur in direct semiconductors satisfy the law of conservation of momentum. 

Molding. Compression mol ding is generally used when it is desirable to conserve material, and when a mol ding operation is set up to allow preparation of large numbers of preforms with minimum labor costs. Flow requirements are minim a1 and high viscosity gums may be used. 

For straight metal pipe under internal pressure the formula for minimum reqiiired w thickness is applicable for D /t ratios greater than 6. Tme more conservative Barlow and Lame equations may also be used. Equation (10-92) includes a factor Y varying with material and temperature to account for the redistribution of circumferential stress which occurs under steady-state creep at high temperature and permits slightly lesser thickness at this range. 

Optimal economic insulation thickness may be determined Iw various methods. Two of these are the minimum-total-cost method and the incremental-cost method (or marginal-cost method). The minimum-total-cost method involves the actual calculations of lost energy and insulation costs for each insulation thickness. The thickness producing the lowest total cost is the optimal economic solution. The optimum thickness is determined to be the point where the last dollar invested in insulation results in exactly 1 in energy-cost savings ( ETI— Economic Thickness for Industrial Insulation, Conservation Pap. 46, Federal Energy Administration, August 1976). The incremental-cost method provides a simplified and direcl solution for the least-cost thickness. 

Another aspect of cost reduction would be solvent economy. The need to preferentially select inexpensive solvents and employ the minimum amount of solvent per analysis would be the third performance criteria. Finally, to conserve sample and to have the capability of determining trace contaminants, the fourth criterion would be that the combination of column and detector should provide the maximum possible mass sensitivity and, thus, the minimum amount of sample. The performance criteria are summarized in Table 1. Certain operating limits are inherent in any analytical instrument and these limits will vary with the purpose for which the instrument was designed. For example, the preparative chromatograph will have very different operating characteristics from those of the analytical chromatograph. 

The primary air flow rate per jet necessary for smokeless combustion depends on the molecular weight and degree of unsaturation of the flare gas. Experience indicates that it varies linearly with percent unsaturates, from a minimum of 20 % excess air for a flare gas containing 0 % unsaturates to 35 % excess air for a gas containing 67 mol % unsaturates. Based on this relationship and a gas flow rate of 72.2 mVh per jet, the required primary air flow rate can be computed directly from the gas composition, or approximated conservatively from the following equation ... 

If separate blast sources are located close to one another, they may be initiated almost simultaneously. Coincidence of their blasts in the far field cannot be raled out, and their respective blasts should be superposed. The safe and most conservative approach to this issue is to assume a maximum initial blast strength of 10 and to sum the combustion energy from each source in question. Further definition of this important issue, for instance the determination of a minimum distance between potential blast sources so that their individual blasts may be considered separately, is a factor in present research. 

The most celebrated textual embodiment of the science of energy was Thomson and Tait s Treatise on Natural Philosophy (1867). Originally intending to treat all branches of natural philosophy, Thomson and Tait in fact produced only the first volume of the Treatise. Taking statics to be derivative from dynamics, they reinterpreted Newton s third law (action-reaction) as conservation of energy, with action viewed as rate of working. Fundamental to the new energy physics was the move to make extremum (maximum or minimum) conditions, rather than point forces, the theoretical foundation of dynamics. The tendency of an entire system to move from one place to another in the most economical way would determine the forces and motions of the various parts of the system. Variational principles (especially least action) thus played a central role in the new dynamics. 

For simplicity, the condition considers the conservative case where the pipe acts simply as a support. The normal practice is to solve all these equations simultaneously, then determine the minimum wall thickness that has strains equal to or less than the allowable design strain. Thus, the minimum structural wall thickness is dictated by the longitudinal tensile load. 

Reaction occurs in the loop as well as in the stirred tank, and it is possible to eliminate the stirred tank so that the reactor volume consists of the heat exchanger and piping. This approach is used for very large reactors. In the limiting case where the loop becomes the CSTR without a separate agitated vessel, Equation (5.35) becomes q/Q > 10. This is similar to the rule-of-thumb discussed in Section 4.5.3 that a recycle loop reactor approximates a CSTR. The reader may wonder why the rule-of-thumb proposed a minimum recycle ratio of 8 in Chapter 4 but 10 here. Thumbs vary in size. More conservative designers have... 

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