Mercury-vapor lamp

Scandium iodide added to mercury vapor lamps produces a highly efficient light source resembling sunlight, which is important for indoor or night-time color TV. 

The metal is widely used in laboratory work for making thermometers, barometers, diffusion pumps, and many other instruments. It is used in making mercury-vapor lamps and advertising... 

In contrast to spectrophotometry, hght-scattering experiments are generally conducted at constant wavelength. Mercury vapor lamps are the most widely used light sources, since the strong lines at 436 and 546 nm are readily isolated by filters to allow monochromatic illumination. Polarizing filters are also included for both the incident and scattered beams so that depolarization can... 

Ultraviolet light sources are based on the mercury vapor arc. The mercury is enclosed ia a quart2 tube and a potential is appHed to electrodes at either end of the tube. The electrodes can be of iron, tungsten, or other metals and the pressure ia a mercury vapor lamp may range from less than 0.1 to >1 MPa (<1 to >10 atm). As the mercury pressure and lamp operating temperatures are iacreased, the radiation becomes more iatense and the width of the emission lines iacreases (17). 

Lighting. An important appHcation of clear fused quartz is as envelop material for mercury vapor lamps (228). In addition to resistance to deformation at operating temperatures and pressures, fused quartz offers ultraviolet transmission to permit color correction. Color is corrected by coating the iaside of the outer envelope of the mercury vapor lamp with phosphor (see Luminescent materials). Ultraviolet light from the arc passes through the fused quartz envelope and excites the phosphor, produciag a color nearer the red end of the spectmm (229). A more recent improvement is the iacorporation of metal haHdes ia the lamp (230,231). 

Minor uses of vanadium chemicals are preparation of vanadium metal from refined pentoxide or vanadium tetrachloride Hquid-phase organic oxidation reactions, eg, production of aniline black dyes for textile use and printing inks color modifiers in mercury-vapor lamps vanadyl fatty acids as driers in paints and varnish and ammonium or sodium vanadates as corrosion inhibitors in flue-gas scmbbers. 

A continuous source has to be employed to record absorption spectra. Fluorescence is usually excited with mercury vapor lamps in the region of their major bands they radiate more powerfully than do xenon lamps (Fig. 14). 

In contrast to the low-pressure lamps (1—130 Pa) which primarily emit at the resonance line at A = 254nm, high-pressure lamps (lO —10 Pa) also produce numerous bands in the UV and VIS regions (Fig. 16). Table 3 lists the emission lines and the relative spectral energies of the most important mercury lamps (see also [44]). The addition of cadmium to a mercury vapor lamp increases the numbei of emission lines particularly in the visible region of the spectrum [45] so that it i. also possible to work at A = 326, 468, 480, 509 and 644 nm [46]. 

However, the optical train illustrated in Figure 22B allows the determination of fluorescence quenching. The interfering effect described above now becomes the major effect and determines the result obtained. For this purpose the deuterium lamp is replaced by a mercury vapor lamp, whose short-wavelength emission line (2 = 254 nm) excites the luminescence indicator in the layer. Since the radiation intensity is now much greater than was the case for the deuterium lamp, the fluorescence emitted by the indicator is also much more intense and is, thus, readily measured. 

A mixture of 4 g of diazoketone (94) and 2.2 g of sodium bicarbonate in 200 ml of tetrahydrofuran and 180 ml of water is irradiated with a Hanovia 200 W mercury vapor lamp (using a Corex filter) until the starting material has been consumed. After addition of 500 ml of water, followed by extraction of nonacidic products, the solution is acidified, cooled to 0° and filtered to yield 2.95 g (76%) of white crystals of crude acid (95) mp 170-176°. An analytical sample has mp 188°. ° ... 

An interesting suggestion was made by Levine in 1969. He supposed that the ketene formed photolytically from 1,2-naphthoquinone diazide could react with unreacted 1,2-naphthoquinone diazide to form a spirolactone-type addition product. This suggestion was tested experimentally almost twenty years later by Huang and Gu (1988). They irradiated 1,2-naphthoquinone diazide in dioxane in the presence of pyrene as sensitizer with a high-pressure mercury vapor lamp (Scheme 10-103). They did indeed obtain the spirolactonespiro(naphtho[4,5 2/,l/]furano-2-one)-3 T -inde-... 

Mercury Vapor Lamp Zinc Vapor Lamp Cadmium Vapor Lamp... 

The functionalization of H-Si(lll) surface has been extended to the reaction with aldehydes. The reaction of H-Si(l 11) with octadecanal activated by irradiation with 150 W mercury vapor lamp (21 h at 20-50 °C) afforded a well-ordered... 

The checkers used a 200-W., high-pressure, mercury-vapor lamp and the corresponding transformer which are available from the Hanovia Lamp Division, Canrad-Hanovia, Inc., 100 C hestnut... 

A. Trichloromethyl chloroformate. A 100-ml., three-necked, round-bottomed Pyrex flask is equipped with a thermometer, a reflux condenser protected at the top with a calcium chloride tube, and a gas-inlet tube with a coarse fritted-glass tip extending almost to the bottom of the flask. In the flask are placed 37.8 g. (0.4 mole) of freshly distilled methyl chloroformate (Note 2) and a Teflon-coated magnetic stirring bar. The flask is illuminated with a 100-W. high-pressure, mercury-vapor lamp (Note 3) which is placed beside... 

Treatment of TR with UV radiation has been shown to be successful in increasing its adhesion to polyurethane adhesive. A low-pressure mercury vapor lamp (main emission at 254 nm power = 20 mW/cm ) has been used. The UV treatment of TR improves the wettabUity, produces the formation of C—O, C=0, and COO moieties, and ablation is also produced. The extended UV treatment produces greater surface modifications, as well as the incorporation of nitrogen moieties at the surface. Peel strength values increase after UV treatment of TR, in a greater extent by increasing the treatment time. 

Mercury switches/mercury relays/mercury vapor lamps... 

For walkways, where 3 foot-candles is an adequate amount of illumination, two 175-watt R-40 mercury vapor lamps placed every 54 ft may be specified. For these and areas that are used continuously but have adequate windows it may be assumed that the lights are on 4,500 hours per year. (This is approximately half the time.) For some interior areas they may never be turned off. At the other extreme, Sarah Lee has an automated warehouse in which the only time lights are needed is when there is an equipment failure. 

SrZn)3(P04)2 Sn2+ SrHP04, SrC03, ZnO, A1203, SnO Used as red-emitting phosphor in high-pressure mercury vapor lamps... 

A mixture of 2-iodotoluene (8.78 g, 0.04 mol) and trimethyl phosphite (24.8 g, 0.20 mol) was placed in a 45-ml, double-jacketed silica reaction vessel. The mixture was degassed by flushing with dry nitrogen for 5 min and irradiated with a 450-watt Hanovia (Model 679A-10) high-pressure quartz mercury vapor lamp fitted with an aluminum reflector head. The lamp was placed 5 cm from the inner portion of the reaction vessel. The reaction temperature was maintained at 0°C by the circulation of coolant from a thermostatically controlled refrigeration unit. Irradiation was continued at this temperature for 24 h. At the end of this time, the volatile materials were removed with a water aspirator, and the residue was vacuum distilled (96 to 97°C/0.25 torr) to give the dimethyl 2-methylphenylphosphonate (7.28 g, 91%). 

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