Containment centrifuges

Equation 65 gives the pressure at any point within the centrifuge, (r), as a function of the coordinate r, the pressure at the axis (0), the angular velocity of the centrifuge, and the temperature and mol wt of the gas. Should the centrifuge contain not a single pure gas, but a gas mixture, equations of the above forms could be written for each species present. In particular for the case of a binary gas mixture, consisting of species M and B. 

Freeze-dried tomato powders obtained from whole tomato fruits and from their pulp after centrifugation, containing 474 and 5399 pg/g dry weight, respectively, were developed for use as additives for food fortification. Cis isomers of lycopene were determined in only a few smdies. The 5-cis-, 9-cis-, and 13-d5 --El5-d5 -lycopene were the isomers found in commercial tomato products. The structures of lycopene cis isomers are shown in Figure 4.2.1 and the structure of the dll-trans isomer is displayed in Figure 6.2.1 in Chapter 6. 

Particles that are smaller and less dense than the nuclei can be obtained by step-by-step acceleration of the gravity on the supernatant left over from the first centrifugation. However, this requires very powerful centrifuges (high-speed centrifuges and ultracentrifuges). The sequence in which the fractions are obtained is mitochondria, membrane vesicles, and ribosomes. Finally, the supernatant from the last centrifugation contains the cytosol with the cell s soluble components, in addition to the buffer. 

Because they occur as large aggregates, micelles, most (90-95%) of the casein in milk is sedimented by centrifugation at 100000 g for 1 h. Sedimentation is more complete at higher (30-37°C) than at low (2°C) temperature, at which some of the casein components dissociate from the micelles and are non-sedimentable. Casein prepared by centrifugation contains its original level of colloidal calcium phosphate and can be redispersed as micelles with properties essentially similar to the original micelles. 

The clear aqueous centrifugate containing water-soluble, ether-insoluble components was fractionated by ion exchange into neutral, weak acid, and strong acid fractions as detailed previously (75, 16). 

The primary operations of the equipment system yield positive results (1) With the highly chlorinated PV crystalline from the centrifuge containing about 60% water as the feeding wet material, the final moisture content of the product from continuous... 

Lebedev [5] describes the production process used in the U.S.S.R. Dinitrophenol from the centrifuge, containing 10-15% of moisture, is dried to obtain a product with only about 0.5% of moisture (drying is effected in picric acid driers). 

The centrifuge contains a stack of conical disks spaced between 0.5 and 2 mm apart. The feed is supplied through a pipe to the center of the bowl at the base of the machine and is distributed into many thin layers. The different phases therefore have only a very short distance to travel to free themselves from each other. Once the solids have contacted the underside of the disks, the settling process is over and the solids move to the periphery of the disks, where they are thrown off the edge onto the bowl wall. 

The crystallized sugar is transferred to centrifuges for removal of free liquor. The sugar from centrifuges contains about 1 percent moisture. They are conveyed to holding bins located above dryers. These dryers... 

It has been found that a 5-10% increase in virgin oil yield can be realized by the addition of plant cell-wall degrading enzymes to the malaxer (217). The enzymes are usually added to early harvested (less ripe) olives. Olives harvested later, when they are more ripe, already contain internal enzymes that have the same effect as the added enzymes. Extraction produces three products oil, an aqueous fraction that creates disposal problems, and a solids residue. The solid residue (pumace) obtained from pressing or centrifugation, contains 4-10% oil. The oil can be solvent extracted and refined. Solvent-extracted pumace oil is of low quality and is usually blended with a better quality virgin oil (215, 218). 

The usual laboratory method for obtaining B. macerans amylase is to culture the organism on an autoclaved potato or oatmeal medium in the presence of calcium carbonate at 37-45° for 2-4 weeks. The culture fluid (filtrate or centrifugate) contains enzyme which can be stored as such,... 

Transfer the culture to a 500 mL centrifuge container and cool it in ice to inhibit further growth. Centrifuge at 6000 r.p.m. (revolutions per minute) for 15 min in a precooled rotor. Decant off the supernatant, and suspend the pellet of bacteria in 50-100 mL of 0.1 ivi Tris-HCI buffer at a pH of 7.5. Centrifuge again as before, and resuspend the pellet in sufficient buffer to give the required cell density or absorbance (for example, 0.5). 

If the liquid fed to a disk or tubular centrifuge contains dirt or other heavy solid particles, the solids accumiJate inside the bowl and must periodically... 

With an acidity of the saturator of 7 per cent, the resulting sulphate crystals are very small. More rapid rotation of the basket than 350 r.p.m. packs the cake so tight as to render it difficult to remove. Because of a rotation of only 350 r.p.m., however, the sulphate discharged from the centrifuge contains about 3 per cent of moisture, necessitating further drying, as by the rotary drier shown in the diagram, to less than the allowable limit of 0.5 per cent. 

De-moisturising of the ZIC is defined in three steps (Figure 3). First, the solids are filtered in two parallel drum Alters, and then the solids pass through the centrifuges. The ZIC from the centrifuges contains 20% moisture. (= dry neutral leach residue) The filtrate is filtered in presses to recover the remaining solids, which are not recovered in the centrifuges. This produces a ZIC with 30% moisture (= wet neutral leach residue). 

The effluent from the centrifuges contains less than 28-mesh coal broken from larger pieces of clean coal. This material is thickened in a cyclone, de-slimed on a screen, and centrifuged prior to loading. 

In the clarification step of microbial suspensions, the tubular and disc centrifugal methods are often used. The tubular bowl centrifuge consists of a vertical cylinder, which rotates between 15 000 and 50 000 rpm, inside a stationary casting. The disc bowl centrifuge contains inverted cones or discs, which operate at 2000-7000 rpm. Due to the continuous and discontinuous operational behaviour of such centrifuges, the tubular centrifuge is applied to suspensions with a maximum of 30 g L of cells, while in the disc, suspensions up to 250 g can be processed. ... 

Young and Conn (25) at Berkeley have found, however, that certain types of plant particles obtained by differential centrifugation contain glutathione-reductase activity. Most of the work here summarized has been done with particles prepared from avocado fruit by a procedure developed by Dr. Jacob B. Biale. These mitochondria from avocados contain an appreciable amount of glutathione-reductase activity which is not removed by repeated washing. The original supernatant fluid from which the particles are removed also contains the enzyme. Analysis of the particles and of the supernatant fluid showed that the specific activity of the glutathione reductase of the particles was about one-fourth to one-half the specific activity of the enzyme in the supernatant fluid. 

The centrifuge contains a liquid layer that is rotating with a high speed (e.g., 2800 rpm), gas bubbles are formed at a fine grid the outer side, and these travel in a centrifugal field of the same order as the one in the cyclone (Versteeg, 1987). 

The system in rat liver has been partially purified (557,768). The supernatant fraction remaining after homogenization and centrifugation contains the activity. Fractionation of this solution by precipitation with neutralized ammonium sulfate reveals that the enzyme system contains two protein components Fraction I (precipitated at 45% saturation and reprecipitated at 25-40% saturation to... 

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