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Fluorescent layers

Whereas the eadiest fluorescent-dye pigments would last only 20 days outdoors in a screen-ink film, fade resistance has been improved to such an extent that some modem daylight-fluorescent coated panels stiU have useful color after nine months or mote in Florida sunlight in a 45° exposure tack facing south. The fluorescent layer is usually coated with an acrylic film containing a uv absorber. Indoor-accelerated exposure equipment is, of course, invaluable in the development of such systems. Better dyes and resins very likely will make possible fat mote stable coatings in the future. [Pg.300]

Muffler, H-J. Bar, M. Lauermann, I. Rahne, K. Schroder, M. Lux-Steiner, M. C. Fischer, C.-H. Niesen, T. P. Karg, F. 2006. Colloid attachment by ILGAR-layers Creating fluorescing layers to increase quantum efficiency of solar cells. Sol. Energy Mater. Sol. Cells 90 3143-3150. [Pg.279]

Fluorescent lamps generate light through a low-pressure mercury vapor discharge that has strong emission tines in the UV, namely at A = 254 nm and around 366 nm. The fluorescent layer is excited by the UV radiation and emits in the visible part of the spectrum. While remains of the 254 nm tine are efficiently rejected by the glass tube, some fraction of the 366 nm radiation can be measured in the emission spectrum of the lamp. [Pg.166]

Fig. 2. Mass spectrometer with photoionization 1—built-in hydrogen lamp 2—vacuum monochromator filled with hydrogen 3—LiF window 4—ionic source container 5—photoionization space with the accelerating grids 6—fluorescent layer for intensity calibration of the incident u.v. light 7—photomultiplier 8—magnetic mass analyzer 9—electron multiplier. Fig. 2. Mass spectrometer with photoionization 1—built-in hydrogen lamp 2—vacuum monochromator filled with hydrogen 3—LiF window 4—ionic source container 5—photoionization space with the accelerating grids 6—fluorescent layer for intensity calibration of the incident u.v. light 7—photomultiplier 8—magnetic mass analyzer 9—electron multiplier.
Fig. 8. Cross section of the cylindrical condenser for measurements of the kinetic energies of the photoelectrons from gas molecules. 1—fluorescent layer for intensity measurements of the incident light 2—thick metallic cylinder with wrought semi-annular slits 3—Teflon insulator 4—cylindrical grid 5—electron collector 6—LiF window 7—diaphragm 8—shutter 9—exit slit of the vacuum monochromator. Fig. 8. Cross section of the cylindrical condenser for measurements of the kinetic energies of the photoelectrons from gas molecules. 1—fluorescent layer for intensity measurements of the incident light 2—thick metallic cylinder with wrought semi-annular slits 3—Teflon insulator 4—cylindrical grid 5—electron collector 6—LiF window 7—diaphragm 8—shutter 9—exit slit of the vacuum monochromator.
Fig. 12. Spherical condenser for measurements of the photoelectron kinetic energy distribution from solids. 1—sample 2—LiF window 3—shutter 4—container of the monochromator exit slit 5—exit slit 6—electron collector 7—fluorescent layer 8—electrostatic screen photomultiplier for intensity measurements of the u.v. light on the left. Fig. 12. Spherical condenser for measurements of the photoelectron kinetic energy distribution from solids. 1—sample 2—LiF window 3—shutter 4—container of the monochromator exit slit 5—exit slit 6—electron collector 7—fluorescent layer 8—electrostatic screen photomultiplier for intensity measurements of the u.v. light on the left.
This fluorescent layer absorbs the ultraviolet light coming off the plasma and radiates the energy in a different form. The new form is visible light. The blend of metals and salts in the fluorescent layer control the color of the new visible light. [Pg.83]

Figure 11.1 Left Layer-by-Layer assembly for the construction of core-shell nanoparticles containing fluorescent outer layers. Right Fully corrected emission spectra of core-shell nanoparticles. The decrease in emission with decreasing distance of the fluorescent layer from the surface is direct evidence of quenching. Reprinted with permission from reference [21]. (2003) American Chemical Society. Figure 11.1 Left Layer-by-Layer assembly for the construction of core-shell nanoparticles containing fluorescent outer layers. Right Fully corrected emission spectra of core-shell nanoparticles. The decrease in emission with decreasing distance of the fluorescent layer from the surface is direct evidence of quenching. Reprinted with permission from reference [21]. (2003) American Chemical Society.
The incident angle of the reflected beam onto the detector is utilized in a factor often described as correcting for the flatness of a detector. The diffracted beam penetrates into the image plate or fluorescent layer of the detector. The penetration length depends on the angle of incidence and the linear attenuation factor for the utilized wavelength and fluorescent material. [Pg.426]

Where l is the thickness of the fluorescence layer. By combination with Eq. (304), it becomes obvious that ... [Pg.292]

Electrodes in fluorescent lamps (coated W or NS-W). Fluorescent lamps are low-pressure mercury discharge lamps which radiate in the UV region. The ultraviolet radiation is converted into light by means of a fluorescent layer (phosphor). Tungsten coils, coated with a mixture of Ca, Ba, and Sr compounds, are used as electrodes (emitter). [Pg.285]

Other requirements are placed on electroluminescent devices in addition to supporting efficient hole and electron transport (1) the exciton energy in the transport layer has to be higher than the exciton energy in the luminescent layer (2) the formation of molecular complexes between the fluorescent layers should be precluded (3) the luminescent layer has to possess a high fluorescence quantum yield and (4) the film should be processed readily. [Pg.148]

Many commercial thin-layer media incorporate a fluorescent indicator, and under ultraviolet light the separated spots may show up dark against the brightly fluorescent background, but a host of substances will not show up under ultraviolet light on these fluorescent layers. [Pg.329]

Sulfonamides can be analyzed both by NP TLC (on silica gel, alumina, polyamide, and Florisil layers) and by RP TLC (on silanized sihca, RP-2, RP-8, and RP-18 layers). Some sulfonamides have been separated by TLC on silica or polyamide impregnated with metal salts. Both aqueous and non-aqueous eluents are applied. Detection of sulfonamides can be performed on fluorescence layers at 254 nm and after derivatization with, for instance, fluorescamine solution at 366 nm. [Pg.93]

Fig. 73 a. Comparison of surface areas. Increasing amounts of phenacetin applied and chromatographed according to Pubdy and Truter s method [549]. A visualised by sparying with ferricyanide-ferric chloride reagent (No. Ill) B inspected on a fluorescence layer in UV-light of 254 nm... [Pg.136]

Stannic chloride (Rgt. No. 236) is now only rarely used for detection. If no success is obtained with fluorescence layers, iodine vapour (Rgt. No. 141) or rhodamine B reagent (No. 220) can be used for non-destructive detection. [Pg.247]

Detection The less volatile tar bases can be detected on fluorescent layers (e. g., silica gel GF264)- Other possibilities are using the spray reagents listed for the amines, e. g., iodine solution (Rgt. No. 144), permanganate solution (Rgt. No. 200), antimony(V) chloride (Rgt. No. 18) or the modified Dragendorff reagent for alkaloids (Rgt. No. 98). [Pg.505]

Detection of barbituric acids is possible non-specifically by chromatography on so-called fluorescent layers, e. g., silica gel GF254. If not present in too small amounts, they appear in short wave UV light as spots of quenched fluorescence. A popular method of detection has been with mercury compounds, especially mercurous nitrate (Rgt. No. 157) which yields insoluble barbiturates [10, 34, 43, 56, 77, 140, 166]. The sensitivity of response varies with the barbituric acid. A combined spray reagent of a mercuric salt and diphenylcarbazone solutions (No. 156) has been often used the spots then stand out better against the background [32, 93, 160]. Cobalt salts have been used with various bases for detection (Zwikker-reaction and modifications, Rgt. No. 51) [56, 152, 170, 174]. N-methylated barbituric acids do not react since the second nitrogen atom cannot take part in enolisation [98]. A further, non-specific method... [Pg.536]

The hydantoin derivatives in Table 112 have been chromatographed on silica gel. Detection is possible on fluorescent layers, using short wave UV light [98] or with the mercury reagents already described for barbituric acid detection [140] the limit of detection is about 10 [xg. The combiued mercuric salt-diphenylcarbazone reagent, mentioned in connection with barbituric acids, has also been employed [129]. [Pg.537]

All these diuretics can be detected on fluorescent layers as dark spots from quenching when exposed to short wave UV light. Quinetha-zone and hydroflumethiazide fluoresce themselves. Most of the compounds can be visualised with a mixture of 5 ml 20% sodium hydroxide, 15 ml 1% disodium pentacyanoammineferrate(II) and a drop of hydrogen peroxide (Fearon s reagent). The reagent can be kept for 24 h. [Pg.548]

A layer impregnated with fluorescein (Rgt. No. 121,6) has been used for detection. Pink spots are formed by amounts exceeding 5 (xg after standing for 1—2 h. Dark blue-violet spots on the green fluorescent layer are seen in long-wave UV radiation. The rhodamine B reagent (No. 120) can also be used, followed by spraying with a 10 % solution of sodium carbonate [101] (see also Rgt. No. 77). [Pg.644]

Visualisation Phloroglucinol derivatives may be detected through their quenching on fluorescence layers in short-wave UV light. Coupling with the stable Past Blue B salt (Bgt. No. 100) yields the colours quoted in Table 172. VoN Schantz [191] gives data about the reaction products... [Pg.713]

Although most steroids have their own U V-absorbance suitable for detection, localization of the spots can be based on the appearance of dark spots at 254 nm UV-light if a fluorescence layer is used most applications involve methods based on chemical reactions. Many spray reagents for the visualization of steroid spots have been described. However, special attention is needed to stabilize the color produced or the fluorescence induced on the plate. Sulfuric acid-methanol (or ethanol) is the most widely used reagent. In addition, phosphoric acid or antimony (III) chloride can be used to detect steroids on the plate or to detect steroids after spot elution. [Pg.977]

Silica gel fluorescent layer (Mallinckrodt Silicar TLC 7GF), 0.5-mm thick Solvent... [Pg.157]

We used to type white text on black background in DOS versirais of Mathcad to save fluorescent layer of a screen. Now people replace their screens as soon as they became obsolete. This is the reason why white scietais substitute for the black. [Pg.228]


See other pages where Fluorescent layers is mentioned: [Pg.297]    [Pg.283]    [Pg.493]    [Pg.169]    [Pg.416]    [Pg.254]    [Pg.148]    [Pg.494]    [Pg.26]    [Pg.76]    [Pg.76]    [Pg.131]    [Pg.146]    [Pg.275]    [Pg.299]    [Pg.483]    [Pg.485]    [Pg.502]    [Pg.526]    [Pg.543]    [Pg.684]    [Pg.382]   
See also in sourсe #XX -- [ Pg.146 ]




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