Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Zinc lamp

Fig. 2.23. Schematic diagram of the laser flash photolysis/UV absorption spectroscopy apparatus employed by Slagle et al. [57] to study reaction (32) at higher pressures. B, Baratron pressure transducer, PS, flow sensor I, iris L, lens NV, needle valve to control total pressure PD, photodiode PM, photomultiplier V, solenoid valve Zn, zinc lamp for... Fig. 2.23. Schematic diagram of the laser flash photolysis/UV absorption spectroscopy apparatus employed by Slagle et al. [57] to study reaction (32) at higher pressures. B, Baratron pressure transducer, PS, flow sensor I, iris L, lens NV, needle valve to control total pressure PD, photodiode PM, photomultiplier V, solenoid valve Zn, zinc lamp for...
HPLC measurements were performed on a Waters radial-compression system with a CN column (particle size 5 xm, cartridge 8-mm i.d.). The HPLC apparatus consisted of an ERC-3110 degasser (Erma Optical Works), a Waters U6K injection system, a filter and a precolumn (CN), and a Beckman 160 UV detector with a zinc lamp at a wavelength of 214 nm. The liquid phase was a mixture of 50 vol % acetonitrile and 50 vol % water that contained 0.005 M dibutylamine phosphate. The flow rate was 2.0 mL min" ... [Pg.178]

Fixed-wavelength detectors have disappeared almost completely from the market. They were run with mercury (254 nm), cadmium (229 nm), and zinc lamps (214 nm). [Pg.90]

Donor and acceptor levels are the active centers in most phosphors, as in zinc sulfide [1314-98-3] ZnS, containing an activator such as Cu and various co-activators. Phosphors are coated onto the inside of fluorescent lamps to convert the intense ultraviolet and blue from the mercury emissions into lower energy light to provide a color balance closer to daylight as in Figure 11. Phosphors can also be stimulated directly by electricity as in the Destriau effect in electroluminescent panels and by an electron beam as in the cathodoluminescence used in television and cathode ray display tubes and in (usually blue) vacuum-fluorescence alphanumeric displays. [Pg.421]

This material has been known for many years, being used originally in the making of electric lamp filaments. In principle vulcanised fibre is produced by the action of zinc chloride on absorbent paper. The zinc chloride causes the cellulosic fibres to swell and be covered with a gelatinous layer. Separate layers of paper may be plied together and the zinc chloride subsequently removed to leave a regenerated cellulose laminate. [Pg.634]

A mixture consisting of 0.69 g (10.5 mmoles) of zinc-copper couple, 12 ml of dry ether, and a small crystal of iodine, is stirred with a magnetic stirrer and 2.34 g (0.7 ml, 8.75 mmoles) of methylene iodide is added. The mixture is warmed with an infrared lamp to initiate the reaction which is allowed to proceed for 30 min in a water bath at 35°. A solution of 0.97 g (2.5 mmoles) of cholest-4-en-3/ -ol in 7 ml of dry ether is added over a period of 20 min, and the mixture is stirred for an additional hr at 40°. The reaction mixture is cooled with an ice bath and diluted with a saturated solution of magnesium chloride. The supernatant is decanted from the precipitate, and the precipitate is washed twice with ether. The combined ether extracts are washed with saturated sodium chloride solution and dried over anhydrous sodium sulfate. The solvent is removed under reduced pressure and the residue is chromatographed immediately on 50 g of alumina (activity III). Elution with benzene gives 0.62 g (62%) of crystalline 4/5,5/5-methylene-5 -cholestan-3/5-ol. Recrystallization from acetone gives material of mp 94-95° Hd -10°. [Pg.112]

Aluminium is widely applied for decorative and protective requirements, while cadmium , zinc and titanium have been applied to ferrous materials chiefly for their protective value. The method finds particular application in the plating of high-tensile steels used in aviation and rocketry, car fittings and lamp reflectors, and gramophone record master discs, as well as in the preparation of specimens for electron microscopy and in rendering insulated surfaces electrically conducting, e.g. metallising of capacitors and resistors. [Pg.440]

Thin-layer plates were made with silica gel-calcium sulfate and each contained a mixture of zinc silicate and zinc cadmium sulfide as phosphors. Separated components are generally visible under ultraviolet light by fluorescence quenching. This was true, in part, for the pyrethrins, except that some of the separated components possessed a natural fluorescence under the ultraviolet lamps. [Pg.63]

Mercury Vapor Lamp Zinc Vapor Lamp Cadmium Vapor Lamp... [Pg.168]

FSM Sosnowiec manufactures automobile lamps, door locks, and window winders for the Polish-manufactured Fiat cars. The lamp bodies are made of zinc-aluminum alloy and then copper-nickel-chromium plated. The door locks and window winders are made of steel and then zinc plated. The wastestreams contain cyanide and the heavy metals chromium (VI), copper, zinc, and nickel. The company carries out the traditional treatments of detoxification, neutralization, and dewatering.29... [Pg.27]

The photodimerization of simple isolated olefinic bonds is rarely observed because of the absorption of these compounds in the high-energy or vacuum-ultraviolet region. One case reported is that of the photo-dimerization of 2-butene.<2) Irradiation of liquid cw-2-butene with light from a cadmium (A = 229, 227, 214 nm) or zinc (A = 214 nm) lamp was reported to lead to dimers (1) and (2) ... [Pg.219]

There are new ideas and experiments on the rTCA cycle. A group from Harvard University studied some reaction steps in the rTCA cycle which were kept going by mineral photochemistry. The authors assumed that solar UV radiation can excite electrons in minerals, and that this energy is sufficient to initiate the corresponding reaction steps. In this photocatalytic process, semiconductor particles were suspended in water in the presence of a zinc sulphide colloid (sphalerite) the experiments were carried out in a 500 mL reaction vessel at 288 K. Irradiation involved a UV immersion lamp (200-410 nm) in the photoreactor. Five reactions out of a total of 11 in the rTCA cycle were chosen to check the hypothesis ... [Pg.198]

Armannsson [659] has described a procedure involving dithizone extraction and flame atomic absorption spectrometry for the determination of cadmium, zinc, lead, copper, nickel, cobalt, and silver in seawater. In this procedure 500 ml of seawater taken in a plastic container is exposed to a 1000 W mercury arc lamp for 5-15 h to break down metal organic complexes. The solution is adjusted to pH 8, and 10 ml of 0.2% dithizone in chloroform added. The 10 ml of chloroform is run off and after adjustment to pH 9.5 the aqueous phase is extracted with a further 10 ml of dithizone. The combined extracts are washed with 50 ml of dilute ammonia. To the organic phases is added 50 ml of 0.2 M-hydrochloric acid. The phases are separated and the aqueous portion washed with 5 ml of chloroform. The aqueous portion is evaporated to dryness and the residue dissolved in 5 ml of 2 M hydrochloric acid (solution A). Perchloric acid (3 ml) is added to the organic portion, evaporated to dryness, and a further 2 ml of 60% perchloric acid added to ensure that all organic matter has been... [Pg.237]


See other pages where Zinc lamp is mentioned: [Pg.221]    [Pg.604]    [Pg.183]    [Pg.183]    [Pg.121]    [Pg.99]    [Pg.92]    [Pg.83]    [Pg.288]    [Pg.415]    [Pg.415]    [Pg.83]    [Pg.92]    [Pg.93]    [Pg.93]    [Pg.212]    [Pg.221]    [Pg.604]    [Pg.183]    [Pg.183]    [Pg.121]    [Pg.99]    [Pg.92]    [Pg.83]    [Pg.288]    [Pg.415]    [Pg.415]    [Pg.83]    [Pg.92]    [Pg.93]    [Pg.93]    [Pg.212]    [Pg.411]    [Pg.163]    [Pg.360]    [Pg.838]    [Pg.498]    [Pg.219]    [Pg.143]    [Pg.179]    [Pg.292]    [Pg.150]    [Pg.106]    [Pg.363]    [Pg.129]    [Pg.173]    [Pg.162]    [Pg.126]    [Pg.130]   
See also in sourсe #XX -- [ Pg.128 ]

See also in sourсe #XX -- [ Pg.99 ]

See also in sourсe #XX -- [ Pg.90 ]




SEARCH



Lampe

Lamps

Lamps zinc/cadmium

© 2024 chempedia.info