Two-chamber

Tbe ASTM D 323 standard describes a method for determining the vapor pressure employing two chambers, A and B the volume of chamber A is four times that of chamber B. 

The two chambers are opened to each other and the apparatus is brought to 37.8°C. The relative pressure resulting is called the Reid vapor pressure . 

Geankoplis [54] fabricated a porous medium for which the values of K, and are known a priori. This was accomplished by sealing a bundle of identical parallel cylindrical capillary tubes between the two chambers of a Wlcke-Kallenbach apparatus. Then the relevant flux relations are those which apply to a single cylindrical capillary, rather than a porous medium, and these are obtained by setting... 

Eventually, not only neutral solvent molecules but also ions start to desorb from the surface. With much of the solvent removed, the ions and residual solvent pass through two chambers, each under partial vacuum to remove more solvent. After passing through the two chambers, the ions are passed to the m/z analyzer. 

The first of these reactions takes place at temperatures of about 150°C, the second reaction proceeds at about 550—660°C. Typical furnaces used to carry out the reaction include cast-iron retorts the Mannheim mechanical furnace, which consists of an enclosed stationary circular muffle having a concave bottom pan and a domed cover and the Laury furnace, which employs a horizontal two-chambered rotating cylinder for the reaction vessel. The most recent design is the Cannon fluid-bed reactor in which the sulfuric acid vapor is injected with the combustion gases into a fluidized bed of salts. The Mannaheim furnace has also been used with potassium chloride as the feed. 

Vacuum Treatment. Milk can be exposed to a vacuum to remove low boiling substances, eg, onions, garlic, and some silage, which may impart off-flavors to the milk, particularly the fat portion. A three-stage vacuum unit, known as a vacreator, produces pressures of 17, 51—68, and 88—95 kPa (127, 381—508, and 660—711 mm Hg). A continuous vacuum unit in the HTST system may consist of one or two chambers and be heated by Hve steam, with an equivalent release of water by evaporation, or flash steam to carry off the volatiles. If Hve steam is used, it must be cuUnary steam which is produced by heating potable water with an indirect heat exchanger. Dry saturated steam is desired for food processing operations. 

The mechanisms that control dmg deUvery from pumps may be classified as vapor-pressure, electromechanical, or elastomeric. The vapor-pressure controlled implantable system depends on the principle that at a given temperature, a Hquid ia equiUbrium with its vapor phase produces a constant pressure that is iadependent of the enclosing volume. The two-chamber system contains iafusate ia a flexible beUows-type reservoir and the Hquid power source ia a separate chamber (142). The vapor pressure compresses the dmg reservoir causiag dmg release at a constant rate. Dmg maybe added to the reservoir percutaneously via a septum, compressing the fluid vapor iato the Hquid state. 

Low Pass Filter Two chambers are connected by a choke tube or pipe. At least one of the chambers should be connected to the compressor cylinder. Figures 13-lB and 13-lC. Melton offers a standardized, simple design that is useful for some types of package compressor arrangement. 

Figure 4.2 An alternative two-chamber gasoline interceptor. (Ventilation not shown dimensions are in millimeters)...

As first shown by Hladky and Haydon 7,8), it is possible to observe the current due to a single transmembrane channel by using extensions of the planar lipid hilaver approach of Mueller and Rudin 9). The basic system is shown in Fig. 2 and is commonly referred to as the black lipid membrane (BLM) method. This is because, as the lipid in the hole between the two chambers thins, the areas that have become planar bilayers are seen as black. Additional terms are bilayer lipid membranes or planar lipid bilayer membranes. These lipid bilayer membranes, particularly those which are solvent free, have capacitances which are very close to those of biological membranes. 

To measure gas and water vapor permeability, a film sample is mounted between two chambers of a permeability cell. One chamber holds the gas or vapor to be used as the permeant. The permeant then diffuses through the film into a second chamber, where a detection method such as infrared spectroscopy, a manometric, gravimetric, or coulometric method isotopic counting or gas-liquid chromatography provides a quantitative measurement (2). Die measurement depends on the specific permeant and the sensitivity required. 

Three general test procedures used to measure the permeability of plastic films are the absolute pressure method, the isostatic method, and the quasi-isostatic method. The absolute pressure method (ASTM D 1434, Gas Transmission Rate of Plastic Film and Sheeting) is used when no gas other than the permeant in question is present. Between the two chambers a pressure differential provides the driving force for permeation. Here the change in pressure on the volume of the low-pressure chamber measures the permeation rate. 

A very important practical case of concentration cell is that in which two electrodes of the same material are immersed in solutions of an electrolyte of different concentrations. Thus, if two silver plates are immersed in solutions of silver nitrate of different concentrations, and are connected by a wire, the metal dissolves in the dilute solution and is precipitated from the strong solution, and this goes on until both solutions have the same concentration. Let us consider a cell containing the solutions of concentration fi, f2 in two chambers A and B, separated by a porous partition, and containing silver plates. When F coulombs pass round the circuit the following changes occur, where n is the migration ratio of the anion ... 

The osmotic pressure is a property that has proven to be especially valuable in the study of solutions of macromolecules, including those of biologic and polymeric interest. The apparatus for measuring this quantity is shown schematically in Figure 7.10. Two compartments are separated by a membrane that will allow the flow of liquid solvent between the two chambers. If solvent is added, flow will occur until the liquid level on the two sides of the membrane is the same. 

C16-0097. The figure represents two chambers containing gases that react as follows ... 

A ceramic block such as alumina is generally used because of its chemical inertness and the orifice is bored or drilled to precise dimensions. The block is placed so that two (2) chambers result. Then if a DC voltage is applied across the electrodes, a current will flow onty through the orifice, and an effective resistance arises which depends upon the voltage applied and the size (volume of the conducting solution) of the orifice. Particles are added to one side of the two chambers created by the ceramic block, and the suspension is pumped through to the other side. There will be an electrical pulse as each particle passes through the orifice. 

Where there is a dosing device provided with the product, the dose reproducibility and accuracy should be demonstrated. Examples include dropper devices, dose-measuring devices, and pen injectors. The instructions for use should also be discussed for such devices and may be particularly important for devices such as two-chamber cartridges and the like containing suspension products. It might be necessary to discuss how dosing devices meet the relevant Essential Requirements of the Medical Device Directives with reference to appropriate and relevant harmonized and other European (EN) and International Standards Organization (ISO) standards. 

Consider a vessel divided into two chambers, separated by a homogeneous lipid membrane. Figure 2.1 is a cartoon of such an arrangement. The left side is the donor compartment, where the sample molecules are first introduced the right side is the acceptor compartment, which at the start has no sample molecules. 

In the commercial version of the PAMPA assay, a sandwich (Fig. 7.9) is formed from a specially-designed 96-well microtiter plate [pION] and a 96-well microfilter plate [several sources], such that each composite well is divided into two chambers donor at the bottom and acceptor at the top, separated by a 125-pm-thick microfilter disk (0.45 pm pores, 70% porosity, 0.3 cm2 cross-sectional area), coated with a 10% wt/vol dodecane solution of egg lecithin (a mixed lipid containing mainly PC, PE, a slight amount of PI, and cholesterol), under conditions that multilamellar bilayers are expected to form inside the filter channels when the system contacts an aqueous buffer solution [543]. 

Figure 16-7 A two-chamber incinerator. The raw waste is charged to the lower incinerator- Here it is burned with a limited air supply in order to develop a high temperature which will gasify most of the solid waste material. Between the chambers the gases pass a restriction (throat) where air is injected. They then enter the second chamber and the flame of the main burner.

Several investigators have used the two-chamber diffusion cell configuration. This experimental method has been found useful to determine diffusion coefficients [11] and to study drug transport from drug delivery devices [12],... 

Srinivasan et al. [17] have described a four-electrode potentiostat system which is suited to maintaining a constant voltage drop across a membrane in a two-chamber diffusion cell. This system was evaluated in connection with trans-dermal iontophoretic drug delivery of polypeptides. 

Figure 5 The Costar Transwell system with a cell monolayer grown on a porous polycarbonate filter that is mounted onto a removable plastic insert forming the apical chamber. Two other systems, (1) the Costar diffusion chamber system, where a filter-grown (Snap-well) cell monolayer is sandwiched between two chambers of equal volume and the bathing solutions are agitated and/or gassed and (2) filter-grown cell monolayers mounted in a two-chamber rotating cylinder device (Imanidis et al., 1996), are not shown.

The permeation technique is another commonly employed method for determining the mutual diffusion coefficient of a polymer-penetrant system. This technique involves a diffusion apparatus with the polymer membrane placed between two chambers. At time zero, the reservoir chamber is filled with the penetrant at a constant activity while the receptor chamber is maintained at zero activity. Therefore, the upstream surface of the polymer membrane is maintained at a concentration of c f. It is noted that c f is the concentration within the polymer surface layer, and this concentration can be related to the bulk concentration or vapor pressure through a partition coefficient or solubility constant. The amount... 

The formaldehyde solutions were prepared by diluting 35.5% aqueous formalin with water. Synthesis of 1 was performed in a two-chamber electrodialyzer described in (8,9). To 30 ml of an aqueous solution of 0.2 M NaxSiW 039... 

Immobilized Mucor miehei lipase (lipase MM) induced the polycondensation of adipic acid and 1,4-butanediol in ether solvents [26]. A horizontal two-chamber reactor was employed to facilitate the use of the molecular sieves. A low disper-sity polyester with DP = 20 was obtained by two-stage polymerization. 

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