Imitation

In general, the final network design should be achieved in the minimum number of units to keep down the capital cost (although this is not the only consideration to keep down the capital cost). To minimize the number of imits in Eq. (7.1), L should be zero and C should be a maximum. Assuming L to be zero in the final design is a reasonable assumption. However, what should be assumed about C Consider the network in Fig. 7.16, which has two components. For there to be two components, the heat duties for streams A and B must exactly balance the duties for streams E and F. Also, the heat duties for streams C and D must exactly balance the duties for streams G and H. Such balemces are likely to be unusual and not easy to predict. The safest assumption for C thus appears to be that there will be one component only, i.e., C = 1. This leads to an important special case when the network has a single component and is loop-free. In this case, ... 

During a hydrotest the additional weight of the water superimposes the normal operational stress by steam pressure. The big advantage of the pneumatic test is now, that it is the best imitation of the normal service condition. 

Fig.6 Godograf of voltage from corrosion imitators in nonmagnetic samples.

For a given current (determined by the amount of film being proeessed), the eoneentration of silver for unit A will be only half the concentration to reach the same current in unit B. Therefore, the silver freight with imit A will be 75% lower than for unit B. 

The questions connected with exception of the subjective factor of process of an estimation of its results are considered by use of the automated monitoring systems. The principles of construction of the automated systems are shown on the basis of the unified imits, and also on a principle of self-training. The examples of the equipment, realized to the present time, are given. 

Ligands are ranked in order of decreasing atomic number of the atom directly connected to the stereogenic imit. 

Artificial Neural Networks (ANNs) are information processing imits which process information in a way that is motivated by the functionality of the biological nervous system. Just as the brain consists of neurons which are connected with one another, an ANN comprises interrelated artificial neurons. The neurons work together to solve a given problem. 

The most straightforward fype of lattice minimisation is performed at constant volume, where the dimensions of the basic imit cell do not change. A more advanced type of calculation is one performed at constant pressure, in which case there are forces on both the atoms and the unit cell as a whole. The lattice vectors are considered as additional variables along with the atomic coordinates. The laws of elasticify describe the behaviour of a material when... 

Program MOCOEFS This program is designed to read in (from the keyboard) the LCAO-MO eoeffieient matrix and write it out to disk. Alternatively, you ean ehoose to have a unit matrix (as your initial guess) put out to disk. With the program 1 imitations deseribed above, MOCOEFS memory usage is 2744 bytes. 

Juvabione is a substance produced by some conifers in imitation of a hormone in an insect pest. It may be a kind of natural control of the pest as it prevents it reaching maturity. 

Stretching a polymer sample tends to orient chain segments and thereby facilitate crystallization. The incorporation of different polymer chains into small patches of crystallinity is equivalent to additional crosslinking and changes the modulus accordingly. Likewise, the presence of finely subdivided solid particles, such as carbon black in rubber, reinforces the polymer in a way that imitates the effect of crystallites. Spontaneous crystal formation and reinforcement... 

Ice cream imitation Iceland spar Ice milk Ice removal... 

Similarly, those proteins can be combined with uncolored ingredients to imitate marbling and form pet foods with chunk-meat appearance. This processing is commonly used in semimoist pet foods. 

Sorhita.n nd Sorbitol Esters. This group of emulsifiers is formed from the reaction of sorbitan and stearic acid. Sorbitan monostearate is often used in combination with polysorbate in ice cream, imitation dairy products, and baking appHcations (36). 

Many trade names have been used for each of these imitations (see Carbon-diamond, synthetic). 

Diamond is supreme among natural gemstones ia H, RI, and DISP. Table 3 shows the steady improvement ia the sequence of diamond imitations, the aim being to produce a colorless, adequately hard material having closely matching optical properties. The iatroduction of synthetic cubic 2irconia ia 1976 brought about a sufficiently close match. 

Several gemstone species occur in various colors, depending on the presence of impurities or irradiation-induced color centers. Examples are the beryl, comndum, and quart2 families. Quart2 has poor optical properties (RI = 1.55, DISP = 0.013), but becomes of gemological interest when it exhibits attractive colors. Any material can have its color modified by the addition of various impurities synthetic mby, sapphires, and spinel are produced commercially in over 100 colors (2). Synthetic cubic 2irconia has been made in essentially all colors of the spectmm (11), but only the colorless diamond imitation is produced commercially in any quantity. 

Cubic Zirconia. As of this writing, cubic zirconia [1314-23 ], is the best diamond imitation available (Table 3). It is marketed under... 

Discredited Synthetics. There are several materials that have in the past been considered to be synthetics, but were found on closet examination not to deserve such a designation, being merely imitations. Examples include imitation coral, lapis la2uli, and turquoise, all made by ceramic processes. This same point has been raised (17) with respect to synthetic opal, which does contain some substances not present in natural opal and somewhat less water. However, the composition of natural opal is quite variable and is usually intermixed with significant amounts of rock-derived materials hence the synthetic designation is usually retained. 

Drilling diamonds using a focused laser beam to bum out dark inclusions or make the inclusions accessible to a chemical treatment is a frequent enhancement. In a potential deception, a cubic zirconia diamond imitation was laser drilled to make it more convincing (15). 

A thin layer of dark green beryl had been grown by a hydrothermal technique over the surface of a pale beryl to imitate emerald. It has been suggested that such stones should be called synthetic emerald-beryl doublets (16). The abiHty to grow thin, but not thick, single-crystal diamond on the surface of natural diamond (17) leads to the possibiHty of growing such a thin film colored blue with boron this has been done experimentally (18). 

Examination of the various classified listings of herbicides provides iasight iato the processes and approaches that lead to the discovery of new pesticides. The four principal development approaches are random screening, imitative chemistry, testing natural products, and biorational development. 

Historically, the discovery of one effective herbicide has led quickly to the preparation and screening of a family of imitative chemicals (3). Herbicide developers have traditionally used combinations of experience, art-based approaches, and intuitive appHcations of classical stmcture—activity relationships to imitate, increase, or make more selective the activity of the parent compound. This trial-and-error process depends on the costs and availabiUties of appropriate starting materials, ease of synthesis of usually inactive intermediates, and alterations of parent compound chemical properties by stepwise addition of substituents that have been effective in the development of other pesticides, eg, halogens or substituted amino groups. The reason a particular imitative compound works is seldom understood, and other pesticidal appHcations are not readily predictable. Novices in this traditional, quite random, process requite several years of training and experience in order to function productively. 

Leather (qv) has been employed for many uses since ancient time on account of the convertibiUty of an easily decomposed substance into one which resists putrefaction. Leather is stUl an important material with its unique stmcture it is so dense in texture that it resists wind and water while retaining breathabihty and flexibiUty, which makes the resulting goods comfortable. Early attempts to imitate leather included appHcation of oil, mbber, or soluble cotton onto paper or fabrics. However, very Htde progress had been made until the era of synthetic resins began in the twentieth century. 

Vinyl-Coated Fabrics. Leather substitutes are designed to imitate the appearance of leather with its grain surface. This requirement has been accomphshed by coating substances that are capable of forming a uniform film, and was first met by plasticized poly(vinyl chloride) (PVC). A leather-like material termed vinyl-coated fabric was developed in the 1930s in the United States and Germany. Shortages of leather after World War 11 spurred the expansion of this material. 

Man-Made Leathers. These materials contain a nonwoven fabric which is impregnated with a polyurethane to improve fiexibiHty, processibiHty, and conformabiHty (Fig. 9). Advanced man-made leathers contain microfibers as fine as 0.03 tex (0.3 den) or less to imitate coUagen fiber bundles, thereby attaining the soft feel and appearance essential for soft leather use. Polyurethane in the substrate is usually provided with porous stmcture by poromeric technology. The coating layer is also porous in the two-layer type man-made leathers (5—10). 

Most manufacturing methods now available are similar to this but with the following modifications in the first step, the polymers for fibers are mainly made of polyester, nylon, or thein blends. AcryUcs and polypropylene are also sometimes employed. A regular fiber as thick as 0.01—0.4 tex (0.1—4 den) may sometimes be used instead of the special fiber to imitate the hard leather. 

Casein hydrolyzates are produced from dried casein. With appropriate heat treatment and the addition of alkaHes and enzymes, digestion proceeds. FoUowing pasteurization, evaporation (qv), and spray drying, a dried product of 2—4% is obtained. Many so-called nondairy products such as coffee cream, topping, and icings utilize caseinates (see Dairy SUBSTITUTES). In addition to fulfilling a nutritional role, the caseinates impart creaminess, firmness, smoothness, and consistency of products. Imitation meats and soups use caseinates as an extender and to improve moistness and smoothness. 

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