X-ray screening

Fig. 1.6 The increase in potency of a 1.3 mM p38 a protein kinase-binding fragment inhibitor identified by X-ray screening through the major changes made to the chemical series to exploit key binding features within the active site.

Linear array of detectors introduced as X-ray screening systems by Picker and... 

Cadmium tungstate (CdWO ) is used in fluorescent paint, X-ray screens, and scintillation counters and as a catalyst. It is very toxic when inhaled. 

As a metal it is malleable and similar to lead, but much heavier in compounds and alloys used in televisions, compact discs, and x-ray screens. 

Figure 1. Cross section of x-ray screens and film assembly...

Figure 2. Relative x-ray absorptions of 100-micron thick x-ray screens using a filtered 80 KV peak x-ray beam...

Several attempts have been made to quantitatively account for various aspects of x-ray screen performances including phosphor efficiencies (I3, x-ray absorption and quantum... 

The overall efficiency of given x-ray screen is given by equation 3. Screen speed, however, also depends on the film Interaction steps nt nt2 shown In Fiaure 1. In practice it is best to determine the overall speed, S, of the screen-film system (26) using the expression ... 

In the optoelectronic X-ray image intensifier (Fig. 86), [5.427], the X-ray phosphor screen (input screen) is in direct optical contact with a photocathode that converts the luminance distribution of the X-ray screen into an electron-density distribution. The liberated electrons are accelerated in an electric field between the photocathode and an anode (20-30 kV) and are focused by electron lenses onto a second phosphor screen (output screen), where conversion of the electron image to a visible image takes place. 

Tungsten chemicals find limited use in inks, paints, enamels, dyes, and glass manufacture. Some tungsten compounds and their derivative phosphors find use in x-ray screens, television picture tubes, and luminescent light sources. 

The principal uses of tungsten compounds lie outside the scope of this chapter (e.g. catalysts for oil refining). WS2 is an effective additive for lubricating oils.41 CaW04 is used as a phosphor for X-ray screens.42 W03 is almost as effective as Mo03 as a flame retardant for poly(vinyl chloride).5... 

Ba[Pt(CN)4] is used in the production of fluorescent X-ray screens.94 Dichlorodihydroxy-diamine- and dichlorodinitratodiamine-platinum(IV) complexes show weak fungicidal activity, but there appears to be no likelihood of them actually being used to this end.95 Other applications of platinum complexes involve their use as anticancer agents, as selective stains in biology, in catalysis, in metallurgy and in photography, described in the relevant chapters of this volume. 

Intensifying Screens Du Pont Cronex Lighting Plus or Fuji Mach 2 medical X-ray screens. Size approx. 40 cm x 15 cm. These are among the most sensitive calcium tungstate screens. Obtainable from Hospital X-ray equipment suppliers. 

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