In feeds

Electrons interact with solid surfaces by elastic and inelastic scattering, and these interactions are employed in electron spectroscopy. For example, electrons that elastically scatter will diffract from a single-crystal lattice. The diffraction pattern can be used as a means of stnictural detenuination, as in FEED. Electrons scatter inelastically by inducing electronic and vibrational excitations in the surface region. These losses fonu the basis of electron energy loss spectroscopy (EELS). An incident electron can also knock out an iimer-shell, or core, electron from an atom in the solid that will, in turn, initiate an Auger process. Electrons can also be used to induce stimulated desorption, as described in section Al.7.5.6. 

The reciprocal lattices shown in figure B 1.21.3 and figure B 1.21.4 correspond directly to the diffraction patterns observed in FEED experiments each reciprocal-lattice vector produces one and only one diffraction spot on the FEED display. It is very convenient that the hemispherical geometry of the typical FEED screen images the reciprocal lattice without distortion for instance, for the square lattice one observes a simple square array of spots on the FEED display. 

Another example is the purification of a P-lactam antibiotic, where process-scale reversed-phase separations began to be used around 1983 when suitable, high pressure process-scale equipment became available. A reversed-phase microparticulate (55—105 p.m particle size) C g siUca column, with a mobile phase of aqueous methanol having 0.1 Af ammonium phosphate at pH 5.3, was able to fractionate out impurities not readily removed by hquid—hquid extraction (37). Optimization of the separation resulted in recovery of product at 93% purity and 95% yield. This type of separation differs markedly from protein purification in feed concentration ( i 50 200 g/L for cefonicid vs 1 to 10 g/L for protein), molecular weight of impurities (<5000 compared to 10,000—100,000 for proteins), and throughputs ( i l-2 mg/(g stationary phasemin) compared to 0.01—0.1 mg/(gmin) for proteins). 

Another example of unique selectivities is the separation of olefins from paraffins in feed mixtures containing about five successive molecular sizes, eg, C Q to Liquid—Hquid extraction might be considered for this separation. However, polar solvents give solubiHty patterns of the type shown in Figure... 

An extraction plant should operate at steady state in accordance with the flow-sheet design for the process. However, fluctuation in feed streams can cause changes in product quaUty unless a sophisticated system of feed-forward control is used (103). Upsets of operation caused by flooding in the column always force shutdowns. Therefore, interface control could be of utmost importance. The plant design should be based on (/) process control (qv) decisions made by trained technical personnel, (2) off-line analysis or limited on-line automatic analysis, and (J) control panels equipped with manual and automatic control for motor speed, flow, interface level, pressure, temperature, etc. 

The concept of the specific resistance used in equation 4 is based on the assumptions that flow is one-dimensional, growth of cake is unrestricted, only soHd and Hquid phases are present, the feed is sufficiently dilute such that the soHds are freely suspended, the filtrate is free of soHds, pressure losses in feed and filtrate piping are negligible, and flow is laminar. Laminar flow is a vaHd assumption in most cake formation operations of practical interest. 

The more variable responses with growing catde appear to result from lower doses, nutritional constraints, or lesser responsiveness of younger animals, ie, veal calves. A dose-dependent reduction in feed intake in finishing cattle, which also reduced average daily gain, has been observed (84). However, carcass composition was improved in a dose-dependent manner. 

H. Gehrke, MnO Deposition in Feed/ot Water Tines in South Dakota, Completion Report No. PB-278809 for projects A-048-SDAK and A-058-SDAK, U.S. Dept, of the Interior, Office of Water Research and Technology, Washiagton, D.C., Jan. 1978. 

Pesticides. Chlorinated hydrocarbon pesticides (qv) are often found in feed or water consumed by cows (19,20) subsequently, they may appear in the milk, where they are not permitted. Tests for pesticides are seldom carried out in the dairy plant, but are most often done in regulatory or private specialized laboratories. Examining milk for insecticide residues involves extraction of fat, because the insecticide is contained in the fat, partitioning with acetonitrile, cleanup (FlorisH [26686-77-1] column) and concentration, saponification if necessary, and determination by means of paper, thin-layer, microcoulometric gas, or electron capture gas chromatography (see Trace and residue analysis). 

Octopamine. Octopamiae [104-14-3] (270) is a monoamine found ia the iasect CNS (70). It is involved in feeding behavior... 

Subchronic effects of overexposure have been studied in feeding tests of PPS powder at dietary levels of up to 5%. No detrimental effects in laboratory animals were observed (157). 

Amino acids are used in feeds (214), food (214), parenteral and enteral nutrition (93), medicine (215), cosmetics (216), and raw materials for the chemical industry (217). 

Purifications of elfamycins have been described in the Hterature using Craig distribution (2,34), chromatography on Sephadex LH-20 (2,14,26) and Amberlite XAD-2 (10,17,19,26), supercritical fluid extraction (37), and chromatography on an Ito multilayer cod planet centrifuge (26,38). and nmr assignments of most elfamycins have been accompHshed (3,24,26,32). The characteristic uv spectra permits some differentiation (12) and bathochromic shifts associated with Al " complexation have been used to quantify efrotomycin (2, R = CH ) in feed premixes (39,40). 

Economy of time and resources dictate using the smallest sized faciHty possible to assure that projected larger scale performance is within tolerable levels of risk and uncertainty. Minimum sizes of such laboratory and pilot units often are set by operabiHty factors not directly involving internal reactor features. These include feed and product transfer line diameters, inventory control in feed and product separation systems, and preheat and temperature maintenance requirements. Most of these extraneous factors favor large units. Large industrial plants can be operated with high service factors for years, whereas it is not unusual for pilot units to operate at sustained conditions for only days or even hours. 

A distinct concern arises in the area of veterinary dmgs because of the possibiUty that dmg residues may be conveyed to humans by the food-producing animals. Therefore, dmg residues and their safety in human food remain a central issue for the Center for Veterinary Medicine (CVM). Animal dmgs also include those products which promotional Hterature claims to improve feed efficiency and increase milk production. An animal food product is regulated under the 1968 Animal Dmg Amendments if it contains a dmg used in feed or premixes (25). 

Favor when partial pressure in feed of components to be removed is high (>1%). 

Favor when partial pressure in feed of components to be removed is low (<1%) and when desired removal is high (purities at the ppm level are not... 

For bulk separations, more highly adsorbed component should be in minority in feed, generally <10 20%. 

Minor Constituents. All four oilseeds contain minor constituents that affect the use of the defatted seeds, especially in feeds and foods. Percentages of phytic acid [83-86-3] (3), for example, are soybean, 1.0—1.5 (30) cottonseed kernels, 2.2—3.8 (25) peanut kernels, 0.8 (25) and sunflower, 1.6-1.7 (31). 

Free substitution of protein meals ia feeds is much more restricted than interchange of oils ia foods. Because of a good balance of essential amino acids, soybean meal is an indispensable ingredient for efficient feeding of nonmminants, eg, poultry and swine. Soybeans provide ca 60% of the world s protein meals, including fish meal (Table 14). Of the 30.0 x 10 t of soybean meal produced in the United States in 1994—1995, 24.2 x 10 t was used domestically, primarily in feeds, and 5.7 x 10 t was exported (50). In the United States, poultry consume the largest share of soybean meal, followed by swine. Lesser amounts are fed to beef and dairy catde. Soybean meal is a principal ingredient in many pet foods (see Feeds and feed additives). 

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