Physical separation

There are several methods described in the literature which enable antigen-specific physical separation of immunocompetent cells antigen-coated columns, derivatized nylon fibers, gradient techniques and electronic cell sorters. These methods will now be considered  

The column technique has been applied to lymphocytes from non-im-munized mice as well (Wigzell and Makela, 1970). A mixture of normal lymph node, spleen and bone-marrow cells was passed through an OA-coated column. Column passed cells as well as control cells were transferred to lethally irradiated mice (10 cells per mouse) and followed by immunization with OA and BSA. The antibody content in the sera was detected by the Farr assay. There was no response to OA, while the response to BSA was normal. Control cell suspensions which were not subjected to the column passage resulted in a good response to both OA and BSA (Table 5). 

Mixture of lymph node, spleen and bone-marrow cells from non-immu-nized mice 

10 column passed cells + OA-fBSA 10 control cells 

2X10 column passed cells + PVP + SA 2x10 control cells 

At the present time, none of these methods is feasible for the quantities or types of heavy abrasives used in maintenance coatings. They are described here for those wanting a general orientation in the area of lead-contaminated blasting debris. 

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Drying refers to the removal of water from a substance through a whole range of processes, including distillation, evaporation, and even physical separations such as with centrifuges. Here, consideration is restricted to the removal of moisture from solids and liquids into a gas stream (usually air) by heat, namely, thermal drying. Some of the types of equipment for removal of water also can be used for removal of organic liquids from solids. 

Physical separation between eddy current functions and system functions, so that the system requirements (encoders amount, trigger specifications, robot control) can be changed without influence on the eddy current modules. 

D. O. Shah and W. C. Hsieh, Microemulsions, Liquid Crystals and Enhanced Oil Recovery, in Theory, Practice, and Process Principles for Physical Separations, Engineering Foundation, New York, 1977. 

Now then, there are some chemists that rely on bisulfite as a tool to physically separate all of their ketone from an oil mix. But some chemists, using some methods, are rightfully sure enough that their ketones were produced in such high yields, and so cleanly, that separation isn t necessary at all. But even they, like anyone else, would still like to know for sure that what they made was P2P. This bisulfite procedure works in this regard as well. If one wants to know if what they made is P2P all one has to do is just drop a mL or so into the saturated bisulfite solution and see what happens. If crystals form, one has ketone. If not, one has fucked up. 

So if one were to replace sec-butyl alcohol in the recipe above with an equimolar amount of safrole in the above reaction, Strike will wager that a positive bromination experience will occur. And all this using the very common 48% aq. HBr The oniy difference being that once the reaction mix had cooled, one should do either of two things (1) distill as described except the bromosafrole will be the last thing to come over (not the first), or (2) flood the reaction mix with water to bring the product out of solution after which it can be physically separated by decanting or sep funnel or some such shit. 

The process takes place in two stages that must be physically separate but temporally adjacent. Figure 1 presents a schematic of a typical parylene deposition process, also indicating the approximate operating conditions. 

Separations. Foams have important uses in separations, both physical and chemical (51,52). These processes take advantage of several different properties of foams. The buoyancy and mechanical rigidity of foam is exploited to physically separate some materials. The large volume of vapor in a foam can be exploited to filter gases. The large surface area of a foam can also be exploited in the separation of chemicals with different surface activities. 

Froth flotation (qv) is a significant use of foam for physical separations. It is used to separate the more precious minerals from the waste rock extracted from mines. This method reHes on the different wetting properties typical for the different extracts. Usually, the waste rock is preferentially wet by water, whereas the more valuable minerals are typically hydrophobic. Thus the mixture of the two powders are immersed in water containing foam promoters. Also added are modifiers which help ensure that the surface of the waste rock is hydrophilic. Upon formation of a foam by bubbling air and by agitation, the waste rock remains in the water while the minerals go to the surface of the bubbles, and are entrapped in the foam. The foam rises, bringing... 

The third characteristic of interest grows directly from the first, ie, the high thermal conductance of the heat pipe can make possible the physical separation of the heat source and the heat consumer (heat sink). Heat pipes >100 m in length have been constmcted and shown to behave predictably (3). Separation of source and sink is especially important in those appHcations in which chemical incompatibilities exist. For example, it may be necessary to inject heat into a reaction vessel. The lowest cost source of heat may be combustion of hydrocarbon fuels. However, contact with an open flame or with the combustion products might jeopardize the desired reaction process. In such a case it might be feasible to carry heat from the flame through the wall of the reaction vessel by use of a heat pipe. 

When a sound wave comes in contact with a soHd stmcture, such as a wall between two spaces, some of the sound energy is transmitted from the vibrating air particles into the stmcture causing it to vibrate. The vibrating stmcture, in turn, transmits some of its vibrational energy into the air particles immediately adjacent on the opposite side, thereby radiating sound to the adjacent space. For an incomplete barrier, such as a fence or open-plan office screen, sound also diffracts over the top and around the ends of the barrier. The subject of this section is confined to complete barriers that provide complete physical separation of two adjacent spaces. Procedures for estimating the acoustical performance of partial barriers can be found in References 5 and 7. 

The essential operations of an extractive metallurgy flow sheet are the decomposition of a metallic compound to yield the metal followed by the physical separation of the reduced metal from the residue. This is usually achieved by a simple reduction or by controlled oxidation of the nonmetal and simultaneous reduction of the metal. This may be accompHshed by the matte smelting and converting processes. 

Reduction to Gaseous Metal. Volatile metals can be reduced and easily and completely separated from the residue before being condensed to a hquid or a soHd product in a container physically separated from the reduction reactor. Reduction to gaseous metal is possible for 2inc, mercury, cadmium, and the alkah and aLkaline-earth metals, but industrial practice is significant only for 2inc, mercury, magnesium, and calcium. 

Separation and Purification of Isomers. 1-Butene and isobutylene caimot be economically separated into pure components by conventional distHlation because they are close boiling isomers (see Table 1 and Eig. 1). 2-Butene can be separated from the other two isomers by simple distHlation. There are four types of separation methods avaHable (/) selective removal of isobutylene by polymeriza tion and separation of 1-butene (2) use of addition reactions with alcohol, acids, or water to selectively produce pure isobutylene and 1-butene (3) selective extraction of isobutylene with a Hquid solvent, usuaHy an acid and (4) physical separation of isobutylene from 1-butene by absorbents. The first two methods take advantage of the reactivity of isobutylene. Eor example, isobutylene reacts about 1000 times faster than 1-butene. Some 1-butene also reacts and gets separated with isobutylene, but recovery of high purity is possible. The choice of a particular method depends on the product slate requirements of the manufacturer. In any case, 2-butene is first separated from the other two isomers by simple distHlation. 

In the physical separation process, a molecular sieve adsorbent is used as in the Union Carbide Olefins Siv process (88—90). Linear butenes are selectively adsorbed, and the isobutylene effluent is distilled to obtain a polymer-grade product. The adsorbent is a synthetic 2eohte, Type 5A in the calcium cation exchanged form (91). UOP also offers an adsorption process, the Sorbutene process (92). The UOP process utilizes ahquid B—B stream, and uses a proprietary rotary valve containing multiple ports, which direct the flow of Hquid to various sections of the adsorber (93,94). The cis- and trans-isomers are alkylated and used in the gasoline blending pool. 

A method for physically separating turbostratic carbon and graphite involves shaking a sample into suspension in ethylene bromide of sp gr 2.17 and centrifliging. The method is unreflable except where fine carbon and coarse graphite are admixed it can be an aid in quaUtative examination. 

A slight excess of calcium is used and the exothermic reaction, carried out in a tantalum cmcible, is initiated at - 900° C. After physical separation of the upper layer of immiscible fluoride slag, vacuum distillation removes unreacted volatile Ca. Cerium can also be made by the electrolytic reduction of fused chloride. 

M. P. Freeman andj. A. Fitzpatrick, eds.. Physical Separations, Engineering Foundation, New York, 1980 A. J. Rubia, ed., Chemisty of Wastewater Technology, Ann Arbor Sci., Ann Arbor, Mich., 1978. 

D. A. Dahlstrom, in M. P. Eteeman and J. A. EitzPatrick, eds.. Theory, Practice and Process Principlesfor Physical Separations, Engineering Eoundation, New York, 1977, pp. 261—273 EPRI ReportF.P. 937, Electric Power Research Institute, Palo Alto, Calif., 1979. 

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