UV systems

Ultraviolet (uv) light has also been used to stetili2e the water in aquaculture systems. The effectiveness of uv decreases with the thickness of the water column being treated, so the water is usually flowed past uv lights as a thin film (alternatively, the water may flow through a tube a few cm in diameter that is surrounded by uv lights). Uv systems require more routine maintenance than o2one systems. Uv bulbs lose their power with time and need... 

The advantages of this method are a short reaction time and the nonfluorescence of the OPA reagent. Therefore, excess reagent must not be removed before the chromatography stage. Using this method, it is possible to measure tryptophan, but not secondary amino acids such as proline or hydroxyproline. Cysteine and cystine can be measured, but because of the low fluorescence of their derivatives, they must be detected using an UV system, or alternatively oxidized to cysteic acid before reaction. 

Fusion UV Curing Systems, AETEK UV Systems, 7600 Standish Place, Rockville, MD 20855-2798... 

Even if few systems are proposed for inorganic compounds (with regard to the number of potential pollutants), instruments or sensors for parameters used for treatment process control are available UV systems for residual chlorine in deodorization, electrochemical sensors for dissolved oxygen (with nowadays a luminescent dissolved-oxygen probe utilizing a sensor coated with a luminescent material) and a colorimetric technique for residual ozone. 

Excitation spectra of D API and Hoechst 3 3 342 are too short for most of the lasers and mirrors that are supplied with commercially available laser scanning microscopes, although these dyes can be imaged in conventional fluorescence microscopes with Xenon or Mercury arc discharge lamp or when using HeNe laser/UV system or multiple photon microscopy... 

For the radiation rapid cure experiments, appropriate resin mixtures containing oligomers, monomers, flow additives and sensitisers (UV) were applied to the substrate as a thin coating, the material placed on a conveyor belt and then exposed to the UV and EB sources. The time taken to observe cure for each of the samples was then measured on a relative basis. The UV system used was a Primarc Minicure unit with lamps of 200W per inch. Two EB facilities were utilised namely a 500KeV Nissin machine and a 175KeV ESI unit. 

In Tables III and IV, the effect of urea on grafting initiated by ionising radiation was reported. Anologous results are obtained with the corresponding UV system (Table XII). The other important observation in Table XII involves the use of two commercial additives in the grafting process. These materials are used in... 

Destruction of chromophoric and nonchromophoric pollutants in pulp and paper effluents may be achieved by advanced oxidation methods such as photocatalysis, photo-oxidation using hydrogen peroxide (H202)/UV or ozone (Osj/UV systems, Fenton-type reactions, wet oxidation, and by employing strong oxidants such as ozone. 

Curing section of a modern coating line with four UV lamps. (Courtesy of Prime UV Systems.)... 

Profiling radiometers measure and display the peak power and total density ion of a UV curing system and also profile the temperature and irradiance as a function of time. The information is transferred into a computer. They are capable of comparing characteristics of multiple lamps, comparing UV systems over time, or comparing different systems to each other. They track and store archival data. An example of profiling radiometers is in Figure 9.6. 

The majority of water-based UV systems are currently being used in the cabinet industry. Water-based UV coatings should be a blend of different resin systems such blends offer certain benefits. Urethane systems offer excellent clarity, hardness, and flexibility. Acrylic resins are easy to apply and offer quick water evaporation. 

Water-based UV systems are gaining the most acceptance where the finishing must look like a traditional lacquer or varnish. Most water-based UV finishes confain 30-35% solids. Currently, it appears that the optimum UV system is a combination of a 100% solids system and water-based system on many wood products. One hundred percent solids finishes are used for sealing and filling the wood. When the wood is filled or sealed as desired, it can be cured and immediately sanded. Then the water-based UV system is applied to get the traditional look without the VOCs and in fewer steps than a traditional wood finish. ... 

Waveguide A device directing microwaves toward the bulb in microwave-powered UV systems. 

Fusion UV Systems www.fusionuv.com UV equipment, UV Kght sources... 

UV inks have been readily and successfully adopted by flexographic label printers, many of them having had several years of experience with letterpress UV systems. Because the common thickness of the printed ink in flexography is typically 2 to 4 pm, in multicolor printing it is often necessary to cure individual layers of inks by UV. With radical UV-curable flexographic printing inks, it is possible to achieve printing speeds of 250 m/min (750 ft/min) or even more.22... 

Prime UV Systems www. pri meu v. com UV equipment, UV light sources, testing equipment... 

Table 2-2 Theoretical amount of oxidants and UV required for the formation of hydroxyl radicals in ozone-peroxide-UV systems (Glaze et al., 1987).

Prengle et al. (1975) were the first to see the commercial potential of the 0-,/UV system in waste water. They showed that this combination enhances the oxidation of complexed cyanides, chlorinated solvents, pesticides and lumped parameters like COD and BOD (cited by Glaze et al., 1987). 

Four bench-scale UV systems used in the treatment of aq expl solns have been investigated (Ref 113). Studies relating the effects of acet and H202 in the treatment are reviewed. Under given conditions, UV light (254nm) in conjunction with small concns of H202 results in the elimination of RDX and other expls from... 

There are also nonchemical processes such as UV systems, which have proved to be of interest and are further described in the following section. 

Similar to the limited popularity of magnetic devices, which do not need carefully planned and executed chemical treatment programs, there is some degree of market demand for UV systems. Periodically there is an increase in the apparent popularity of these products before the groundswell dies down to a base level. UV systems are effective sterilizers for high-quality water systems, such as may be found in electronic chip washing or pharmaceutical use. They are commonly used as sterilizers for RO-treated water. 

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