Filter, ultraviolet

Later investigations have fully confirmed the conclusion that the crosslinking of the higher alkyl methacrylate polymers will take place on a gallery wall. We have been able to demonstrate that an induction time of about 11 years occurs before insoluble matter begins to form in commercial normal and isobutyl polymers on a well-illuminated museum wall (1,11). Protection against such loss of solubility is one of a number of reasons for recommending the use of ultraviolet filters over windows and over fluorescent-lamp sources in museums (12). 

Laboratory and epidemiological data suggest that various polychlorinated biphenyls, dioxins, flame retardants, pesticides (e.g., DDT), perfluorinated chemicals, phthalates, bisphenols, and ultraviolet filters may inhibit thyroid function through a variety of mechanisms [31-33]. 

A review on image stability in colour photography has been published (79MI11401). Ultraviolet filters which absorb harmful radiation have been used for the protection of image dyes. These are exemplified by the benzotriazole (98) (72GEP2036719) and the pyrrolidine (99) (81BRP1592742). 

Ultraviolet light damages proteins as well as DNA. Residues of Trp, Tyr, His, Cys, and Met are especially susceptible to photolysis, or photooxidation by 02, or by singlet oxygen. Also damaged are unsaturated lipids, porphyrins, flavins, etc. Kynurenic acid (Fig. 25-11) and urocanic acid (Eq. 14-44), an important ultraviolet filter in skin,196 are also decomposed by light. 

Because the most common museum ultraviolet filters presently in use have transmissions that are comparable to the 385 nm nominal cut-off filter used in the tests, yellowing would be expected. In order to suppress the discoloration of Parylene-C-coated artifacts, a filter with an effective cut-off at 400 nm is required. After a 500 hour exposure, the color change of Parylene-C exposed through the 385 nm filter was 1 AE unit. 

Nash IF. Human safety and efficacy of ultraviolet filters and sunscreen products. Dermatol Clin 2006 24 35-51. 

Figure 1 Wavelength distribution of a xenon lamp with a specific ultraviolet filter compared to the solar spectral irradiance according to the Commission Internationale de I Eclairage.

Figure 10 Scheme of the proposed protocol tor detennination of photostability of cosmetic ultraviolet filters (25). 

Ultraviolet Filtering and Transmitting Formulations of Plexiglas Acrylic Plastic, PL-612e Rohm and Haas, 1985. 

Ultraviolet Filters for Fluorescent Lamps CCI Notes, National Museums of Canada, 1983 Vol. 2, No. 1. 

The 200 to 400 nm spectral Irradlance Inside the CER was measured using a Gamma Scientific Spectroradlometer. A selenium photovoltaic cell and Corning 7-45 ultraviolet filter was used to monitor the UV Irradlance. A 1 x 2 cm silicon solar cell was used to measure the near-IR Irradlance. CER photon flux was also calibrated by using 0-nltrobenzaldehyde (0-NBA) as an actlnometer( ). Outdoor photon flux was measured by dispersing 0-NBA In thin films (25 urn) of polymethyl methacrylate. These films were then exposed at the outdoor site behind a neutral density filter and were examined on a weekly basis. Outdoor weekly UV photon flux was calculated based on the conversion rate of the 0-NBA. 

The radiotracer method has also been used in hiunan subjects if the test compoimd is not toxic (Feldmann and Maibach, 1969, 1970, 1974). This approach was employed to assess percutaneous absorption of pesticides in swine (Qiao etal., 1994), in human testing of ultraviolet filters (Benech-Kieffer et al., 2003), and for determination of topical absorption of cosmetics (Malhotra et al., 2001) for clinical safety assessment. 

Products and Uses A UV (ultraviolet) filter or screen in suntan lotions, creams, oils, protectants, and... 

Ultraviolet radiation is one of the primary causes of aging in organic materials. Measuring the ultraviolet radiation thus tells us much more about the stress on the material than measuring the total radiation. The irradiance in the ultraviolet range, l v. usually measured with a device equipped with a photocell receiver and a broadband ultraviolet filter. This combination makes the measuring device sensitive to the spectrum between 300 and 400 nm. A diffusing cap ensures that the evaluation of the radiation takes proper... 

With an ageing population, the occurrence of cataract has increased. This disease results in opacification of the natural crystalline lens. The only way to treat this kind of blindness is to extract the opacified lens and to replace it either externally by very thick glasses, or internally by intraocular lenses (lOLs). PMMA that has been modified by the addition of an ultraviolet-filtering additive to protect the retina has been used to manufacture the optic part of the device. 

Cosmetics, sunscreens, ultraviolet filters Refractory brominated organic compounds Complexing agents and anticorrosive additives Widely manufactured cyclic ether Organosilicon compounds with many uses Commonly released in the processing of oil sands... 

Home Water Purifiers and Filters.com, accessed June 26 2014, http //www. home-water-purifiers-and-filters.com/ultraviolet-filter.php... 

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