Spray methods

The slurries of electro-catalysts were prepared by mixing together the catalysts and appropriate amount of 5wt % Nafion solution(Du Pont) including some kinds of dispersant[8]. The electrodes were made by spraying method with these well mixed inks. Two electrodes and Nafion 112 membrane were hot pressed with the condition of 50kgf/cm, 120°C for 3min to fabricate MEAs(Membrane Electrode Assembly). 

The water spraying method is most commonly used to reduce fugitive dusts emission by spraying water onto the exposed surface area, for example, along active travel paths, excavation areas, and truck boxes loaded with soils. 

Spraying methods onto support films Viruses, macromolecules, and liposomes Spiess et al. (41)... 

Mass spectrometry is traditionally a gas phase technique for the analysis of relatively volatile samples. Effluents from gas chromatographs are already in a suitable form and other readily vaporized samples could be fairly easily accommodated. However the coupling of mass spectrometry to liquid streams, e.g. HPLC and capillary electrophoresis, posed a new problem and several different methods are now in use. These include the spray methods mentioned below and bombarding with atoms (fast atom bombardment, FAB) or ions (secondary-ion mass spectrometry, SIMS). The part of the instrument in which ionization of the neutral molecules occurs is called the ion source. The commonest method of... 

In order to obtain adjacent active and inactive channels which provide internal heat exchange capability as described in Section 12.3.3, the metal foils are generally coated on a single side with the active catalyst layer. Deposition of the active layer is typically effected by spraying methods [18, 59-61]. 

The spray method was used to produce alumina pigments doped with Cr, Mn, and Co. In these experiments, Al(.vec-OBu)3 was mixed with solutions of the corresponding metal nitrates in. veobutoxide, the resulting liquids were nebulized, and then the droplets were hydrolyzed (76). The major purpose of these studies was to obtain inorganic pigments and to evaluate their color properties by altering the amount of dopants in the aluminum oxide matrix. For the same reason, the vanadium... 

The other important factor to affect the operational conditions of the cell is the voltage increase between the carbon and copper lead. This problem has been solved individually in industry. For example, a 250 pm thick layer of nickel can be coated onto the upper part of the carbon anode using the atmospheric plasma spraying method.7 This electrode has been operated at 15 to 17 A dm-2 in a 1000 A scale industrial cell for 19 months. The cell voltage was 9.5 V and polarization did not occur with this electrode. Characteristic points of this new carbon electrode are low polarizability and no anode effect, and the concentration of carbon tetrafluoride contaminating the fluorine is below 2 ppm. 

The most significant characteristic of the top spray method is that the nozzle sprays countercurrently or down, into the fluidizing particles. The fluidization pattern is very random and... 

Fig. 11. Scanning electron jiiotomicrograi showing product layered hy tangential spray method. Magnification = 175 x.

Joseph (1989) lists relative efficiencies for different spray methods as follows ... 

The physical and metallurgical properties of plasma sprayed coatings are generally superior to all other flame spraying methods, with the exceptions of hypersonic combustion and detonation gun systems. 

Hypersonic coatings can be routinely reproduced by controlling all the operation s variable parameters, which are less critical than for other flame spray methods. In particular, coating integrity is not significantly affected by changes in "gun-to-workpiece" distance. This... 

Chemical and physical vapor deposition technique has been widely applied for the preparation of such photocatalytic thin films. Since these vapor methods need an instrumental setup which enables control of temperature and pressure, their initial and running costs are generally high and the size of substrate is limited. Spray method, in which titanium alkoxide and water is sprayed on a substrate heated at a desired temperature, affords Ti02 thin films.69) However, like the sol-gel route, the physical properties and photocatalytic activity of Ti02 strongly depend on many factors such as temperature of substrate, flow rate of carrier gas, and partial pressure of starting material in the system. 

Spray methods for obtaining microspheres have a number of disadvantages. High temperatures and bulky and complicated equipment are needed moreover they pose fire and explosion hazards. Low temperature methods, such as using emulsified thermoplast solutions, saturated polyester resins in liquid heat carriers, or suspension polymerization, are preferable1,3S). 

Method 3 (TLC). The amino acids and peptides are separated on silica gel plates with butanol-acetic acid-ethyl acetate-water (1 1 1 1). The chromatogram is dried at 110 °C for 10 min and then cooled to room temperature. The plate is sprayed with a 10% solution of triethylamine in methylene chloride and is dried in air for several seconds. A solution of 0.05% fluorescamine in acetone is then sprayed on to the plate. The plate is again dried in air and is then resprayed with the triethylamine solution before observation under UV light. This procedure was found to be superior to the earlier procedure of using aqueous buffers for spraying the plates prior to fluorescamine reaction [89]. The limit of detection for the modified spray method is 0.5 nmole of the amino acid or peptide. 

Nevertheless, the method was used to determine Guthion (an organothiophosphorus compound) in water at the 0.5 ppb level. This particular insecticide is difficult to determine by glc and at the time the method offered a reasonable alternative. Guthion was also determined in blueberries with 85% recovery at 0.5 ppm using the SAQH-Mn spray reagent after separation on tic ( 19 ). The major- difficulty with the chelate spray method is that bromine vapours will also react with a variety of compounds. Thus, a rigorous clean-up may be necessary for samples with many coextractives. ... 

Several spraying methods can be used to apply adhesives, including conventional air spray, hydraulic cold airless spray, hot spray, and hot airless spray. The main types of spray equipment are summarized in Table 17.1. 

Heating the adhesive before atomization enables heavier adhesive buildup, reduces overspray losses, and minimizes contamination from atmospheric water vapor. Spray methods can be used on both small and large production runs. The liquid to be sprayed is generally in solvent solution. Sizable amounts of product may be lost from overspray. Two-component adhesives are usually mixed prior to placement in the spray gun reservoir. Application systems are available, however, that meter and mix the adhesive within the spray gun barrel. This is ideal for fast-reacting systems, but guns must be thoroughly cleaned to avoid buildup of polymerized product. 

The principle and possible applications of the three basic processing options (top-spray, bottom-spray or tangential-spray) of the batch-fluidised bed are discussed below (Jones 1994). Both the top- and bottom-spray methods are characterised by a conical product container and expansion chamber, resulting in a more vigorous fluidisation pattern and a decrease in velocity as the particles move upward in the expansion chamber. 

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