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UV sources

Fig. 2. Schematic of the RISTON dry film photoresist process, (a) Removal of polyolefin separator sheet and laminate resist to clean surface, using special laminator (b) exposure to uv source using positive or negative phototool (positive to plate negative for print-and-etch) (c) removal of the protective Mylar, which is readily removed by hand and (d) development using a special processor (3). Fig. 2. Schematic of the RISTON dry film photoresist process, (a) Removal of polyolefin separator sheet and laminate resist to clean surface, using special laminator (b) exposure to uv source using positive or negative phototool (positive to plate negative for print-and-etch) (c) removal of the protective Mylar, which is readily removed by hand and (d) development using a special processor (3).
A typical photoionization detector is shown in Figure 3.11. The UV source is a discharge lamp, containing an inert gas or gaal mixture at low pressure, that emits monochromatic light of 1... [Pg.139]

Figure 2. Rates of photodegradation of the copolymer when exposed to a broadband UV source (shortest wavelength 297 nm) (A) change in absorbance as a function of irradiation time in the wavelength range of 250-450 nm (spectrum measured on films) (B) change in absorbance at 3580 cm 1 measured by FTIR spectroscopy (rate of hydroxyl formation)... Figure 2. Rates of photodegradation of the copolymer when exposed to a broadband UV source (shortest wavelength 297 nm) (A) change in absorbance as a function of irradiation time in the wavelength range of 250-450 nm (spectrum measured on films) (B) change in absorbance at 3580 cm 1 measured by FTIR spectroscopy (rate of hydroxyl formation)...
Interaction of chlorine with methane is explosive at ambient temperature over yellow mercury oxide [1], and mixtures containing above 20 vol% of chlorine are explosive [2], Mixtures of acetylene and chlorine may explode on initiation by sunlight, other UV source, or high temperatures, sometimes very violently [3], Mixtures with ethylene explode on initiation by sunlight, etc., or over mercury, mercury oxide or silver oxide at ambient temperature, or over lead oxide at 100°C [1,4], Interaction with ethane over activated carbon at 350°C has caused explosions, but added carbon dioxide reduces the risk [5], Accidental introduction of gasoline into a cylinder of liquid chlorine caused a slow exothermic reaction which accelerated to detonation. This effect was verified [6], Injection of liquid chlorine into a naphtha-sodium hydroxide mixture (to generate hypochlorite in situ) caused a violent explosion. Several other incidents involving violent reactions of saturated hydrocarbons with chlorine were noted [7],... [Pg.1406]

LABORATORY IR SOURCE UV SOURCE DETECTOR TIME RESOLUTION... [Pg.290]

In luminescent microscope, light from the ultraviolet source (UV source) excites the fluorescence of the object, the luminescent image might be catched... [Pg.114]

Chemat and his coworkers [92] have proposed an innovative MW-UV combined reactor (Fig. 14.7) based on the construction of a commercially available MW reactor, the Synthewave 402 (Prolabo) [9[. It is a monomode microwave oven cavity operating at 2.45 GHz designed for both solvent and dry media reactions. A sample in the quartz reaction vessel could be magnetically stirred and its temperature was monitored by means of an IR pyrometer. The reaction systems were irradiated from an external source of UV radiation (a 240-W medium-pressure mercury lamp). Similar photochemical applications in a Synthewave reactor using either an external or internal UV source have been reported by Louerat and Loupy [93],... [Pg.470]

Product distributions and reaction conversions of several different photochemical systems, irradiated by conventional UV source and by EDL in a MW-UV reactor (Fig. 14.5), were compared to elucidate the advantages and disadvantages of a micro-wave photochemical reactor [90], Some reactions, e.g. photolysis of phenacyl benzoate in the presence of triethylamine or photoreduction of acetophenone by 2-propa-nol, were moderately enhanced by MW heating. The efficiency of chlorobenzene photosubstitution in methanol, on the other hand, increased dramatically with increasing reaction temperature. [Pg.476]

UV-radiation curing has become a well-accepted technology which has found numerous industrial applications because of its distinct advantages 1-3. One of its main characteristics is the rapidity of the process which transforms quasi-instantly the liquid resin into a solid polymer under intense illumination by a UV-source or a laser beam4. The polymerization rate can be finely controlled by acting on the initiation rate through the intensity of the UV radiation. It is... [Pg.63]

Wet oxidation of samples of biological origin with a mixture of nitric acid and perchloric acid is a common procedure that may be problematic in certain cases. An alternative procedure for sample preparation is irradiation with a strong UV source. Acidified samples of hair (0.1 g) containing about 2 pg Pb and other trace elements, were irradiated for 3 h with a 500 W source a buffer (pH 5.5) and a small amount of catechol violet (9) were added, and the complex of the dye with the trace elements was determined polarographically RSD ca 5% for Pb95. [Pg.438]

Monitoring the radiation of sunbeds serves two major purposes - finding out the current radiation intensity and establishing the (accumulated and biologically effective) dose the user has been exposed to. The intensity of the fluorescent lamps that are usually used as UV source decreases in time. As a consequence, a longer tanning session is needed for a particular dose. [Pg.171]

Photoionization mass spectrometry, by way of contrast, is a low-tem-perature variant. It employs a monochromated UV source to detect accurately the onset of molecular dissociation (see Section II,A). The heats of formation of KrF2 (28) and HOF (24) have been so measured. [Pg.28]

In view of the results obtained by Bell and Friedman (136) it is possible that sunlight could bring about a photochemical solubilisation of Pu(IV) polymers. These workers obtained 13 % degradation of polymeric plutonium in the presence of organic materials in one hour when the polymer (0.0093m Pu in 0.47m HC104) was irradiated at 260—280 nm. This degradation rate was four times faster than that observed over a similar period of time in the absence of the UV source. [Pg.66]

Polymers are organic materials and are sensitive to natural or artificial UV sources. This is of primary importance for outdoor exposure of unprotected parts and for some industrial applications such as electrical welding, photocopier light exposure devices. .. [Pg.166]

Monomer I (MAA) was dissolved in methanol and I moI% of crosslinking agent, tetraethyleneglycol dimethylacrylate (TEGDMA) (Polysciences, Inc., Warrington, PA), and I wt% of initiator, 2,2-dimethoxy-2-phenyI acetophenone (DMPA Aldrich, Milwaukee, WI) were added. The solution was cast on glass plates equipped with spacers and reacted under an UV source with an intensity of 1 mW/cm for 30 min. Polymer I (PMAA) was removed from the plates, washed in deionized water to remove all unreacted monomers, cut into discs, and dried in a vacuum oven. [Pg.163]

Dubroeucz, G. M. Zahorsky, D. "KrF Excimer Laser as a Future Deep UV Source for Projection Printing," International Conference on Microlithography, Grenoble, France, Oct. 1982. [Pg.158]


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See also in sourсe #XX -- [ Pg.65 ]




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UV Sources for Industrial Applications

UV light sources

UV radiation sources

Vacuum-UV sources

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