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Solar lamp

Fig. 124 is a representation of Winfield s lucent burner, in which the Liverpool button is applied to an argand gas-burner, and the peculiar form of ohimney causes an external current of air to impinge at a certain angle npon the flame, producing the same effect as the metallic cone in the solar lamp a basket of wire-gauze is fitted into the crutch of tire burner, which moderates the supply of air from below, and prevents the flickering caused by sudden draughts. [Pg.164]

Photoinduced free-radical halogenation is very useful for the functionalization of electron-deficient alkenes such as vinyl halides. Among halides, the addition of bromine is by far the most useful reaction, as shown in Scheme 3.25. In the first example, a polyfluoroalkene was brominated in a high yield by using a 300 W light bulb as the light source. Of note, the synthesis of l,2,4-tribromo-l,l,2-trifluorobutane (38) was carried out under solvent-free conditions in a near-quantitative yield and on a multigram scale (Scheme 3.25a) [67]. l,2-Dibromo-l,l,2-trichloroethane (39) was likewise obtained in about 250 g amounts by the solar lamp irradiation of neat trichloroethylene to which bromine was continuously added (Scheme 3.25b) [68],... [Pg.84]

Pyrex Glass Bottle Illuminated by Solar Lamp... [Pg.445]

Tetrachlorodibenzo-p-dioxin (TCDD) (I), an occasional contaminant in 2,4,5-T and other trichlorophenol derivatives, is the most toxic of the commonly-encountered dioxins (8) and it received most of our attention. Its low solubility in common solvents and water (ca. 2 ppb) limited our experiments since the products were difficult to identify by the conventional techniques of organic chemistry. However, TCDD has an absorption maximum at 307 nm in methanol—well within the solar spectrum observed at the earth s surface and near the region of maximum intensity (310-330 nm) of the UV lamps used in previous experiments (H 29). [Pg.46]

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]

Sunbeds with fluorescent lamps that emit in the UVA and UVB are used for indoor tanning. They are supposed to simulate the solar UV spectrum and have therefore similar effects on the human skin. However, the intensity of radiation is often not monitored, and excessive exposure may cause serious dermatological health problems. A more detailed analysis reveals that the long-wave UV (UVA) is mainly responsible for the tanning while UVB radiation tends to be more dangerous. [Pg.167]

With filtering to cut out the radiation below 300 nm and to reduce the infrared, xenon lamps provide a quite good simulation of sunlight across the spectrum. They are now considered the preferred source where the total solar spectrum is required and the method, ISO 4892-2 [27], is nominated in ISO 11403-3 [23]. Unfortunately, xenon lamp apparatus is very expensive and the exposure temperature is usually rather high. [Pg.72]

More recently, metal halide lamps have been introduced that give a reasonable simulation of sunlight and offer very high irradiance with modest heat generation. They have mostly been employed in large solar simulation systems. [Pg.72]

Xenon lamps can be filtered to approximate the solar spectrum under glass and a fluorescent lamp, the UVB 351, does this in the ultraviolet region... [Pg.72]

In a Rapra study both natural PP and HDPE were tested together with similar materials containing carbon black as a stabiliser. The carbon black containing materials showed essentially no change in tensile strength after 1,035 days exposure in the UK, 510 days in Australia and 200 days in various accelerated exposures using QUVA lamps (fluorescent tubes which stimulate the UV sector (<400 nm wavelength)) and Xenon arc equipment (which stimulates the solar system). [Pg.159]

Irradiation Mercury lamps Mercury lamps Fluorescent tubes Black fluorescent lamps Black fluorescent lamps Solar... [Pg.65]

Fig. 3.21 Maximum efficiency possible depending upon semiconductor bandgap, under xenon arc lamp and AM 1.5 solar illuminations. Fig. 3.21 Maximum efficiency possible depending upon semiconductor bandgap, under xenon arc lamp and AM 1.5 solar illuminations.
In research laboratories, different types of light sources are used instead of solar radiation. In most cases the simulated spectrums have considerable deviation from the solar spectrum. Based on equation (3.6.9) Murphy et al [109] analyzed the maximum possible efficiencies for different materials according to their band gap in the case of solar global AM 1.5 illumination and xenon arc lamp, see Fig. 3.21. For example, anatase titania with a bandgap of 3.2 eV has a maximum possible efficiency of 1.3% under AM 1.5 illumination, and 1.7% using Xe lamp without any filter. For rutile titania these values are 2.2% and 2.3% respectively. [Pg.164]

Fig 7.8 Photocatalytic H2 evolution from an aqueous K2SO3 (0.25 mol/L)-Na2S (0.35 ml/L) solution (150 mL) under a simulated sun light irradiation over Pt (3.0 wt%)-loaded (AgIn)o,22Zni,56S2 solid solution heat-treated in a quartz ampule tube at 1123 K. Catalyst 0.3 g. solar simulator 300 W Xe short arc lamp with AM 1.5 filter. Reaction cell top window Pyrex cell. Irradiated area 33 cm Reprinted with permission from Ref. [165]. [Pg.460]


See other pages where Solar lamp is mentioned: [Pg.618]    [Pg.461]    [Pg.97]    [Pg.618]    [Pg.461]    [Pg.97]    [Pg.325]    [Pg.314]    [Pg.345]    [Pg.123]    [Pg.293]    [Pg.216]    [Pg.221]    [Pg.46]    [Pg.213]    [Pg.46]    [Pg.49]    [Pg.70]    [Pg.248]    [Pg.267]    [Pg.268]    [Pg.270]    [Pg.21]    [Pg.142]    [Pg.450]    [Pg.34]    [Pg.537]    [Pg.150]    [Pg.319]    [Pg.591]    [Pg.946]    [Pg.992]    [Pg.81]    [Pg.273]    [Pg.5]    [Pg.341]    [Pg.446]    [Pg.452]   
See also in sourсe #XX -- [ Pg.445 , Pg.461 ]




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