Side-window

Development of a benchtop energy dispersive analyser BRA-18 is carrying out which is based on Si-drift detector and x-ray tube with side window range of the elements to be determined is extended from Mg to U. The distinctive feature of the device is that a specimen to be analysed is placed in the open air. 

Another source of increased drag involves the external-surface details. In this regard, stand-alone bumpers, externally protruding door handles, and running boards alongside the passenger compartment to facilitate entity, all of which were once universal, have disappeared. Flush rather than recessed side windows have come into recent use. On the other hand, external rear view mirrors, which increase drag, have been added as a safety measure. 

Fig. 2-4. Mean pulse height versus quantum energy, to illustrate pulse-height selection of characteristic lines. Side window tube, 3-in. diameter 0.005-in. wire operating at 1275 v filled with argon plus 10% ethylene total pressure, 15 cm of mercury (proportional counter) gain, 3.5 X 104. (After Friedman, Birks, and Brooks, A STM Spec. Tech. Publ., No. 157, page 3. Copyright 1954. American Society for Testing Materials.)...

Gases, such as automobile exhausts and polluted air, can be measured by IR spectrometry. A special cell is used for containing the gas. This cell is cylindrically shaped and has inlet and outlet stopcocks for introducing the sample. The side windows of the cylinder are nonabsorbing inorganic salt crystals. 

Figure 12.20. Structure of (a) side-window and (b) linear focused photomultipliers.

Figure 12.20 shows the structure of the side-window circular cage type and linear focused head-on type of photomultiplier which are both preeminent in fluorescence studies. The lower cost of side-window tubes tends to favor their use for steady-state studies, whereas the ultimate performance for lifetime studies is probably at present provided by linear focused devices. In both types internal current amplification is achieved by virtue of secondary electron emission from discrete dynode stages, usually constructed of copper-beryllium (CuBe) alloy, though gallium-phosphide (GaP) first dynodes have been used to obtain higher gains. 

Low transit-time dispersion with photon wavelength, i.e., < 0.5 psec/nm. This minimizes the effect on convolution of the difference between the excitation and fluorescence wavelengths. Both side-window and linear focused photomultipliers satisfy this. 

Low transit-time dispersion with point of illumination on the photocathode, i.e., < 20 psec/mm. Linear focused photomultipliers satisfy this criterion, but side-window devices do not. This again is relevant to successful data analysis. 

Probably the two most widely used types of photomultipliers for fluorescence lifetime work are the Phillips XP2020Q linear focused device and the Hamamatsu R928 side-window device. The R928 has a response up to ca. 930 nm and this wavelength is achieved with variants of the XP2020Q. 

The performance of the R928 and its variants has been well documented in pulse 12,31,78 81) and phase-modulation 57, 82) lifetime fluorometry. The lower cost and gain of side-window photomultipliers makes them the best all-round compromise for use in dual purpose instruments with both steady-state and lifetime capabilities. 

Another side-window photomultiplier often used in red/near-IR fluorescence studies is the Hamamatsu R636 with a gallium-arsenide (cesium) (GaAs(Cs)) photocathode. 11,53)... 

W. R. Ware, M. Pratinidhi and R. K. Bauer, Performance characteristics of a small side-window photomultiplier in laser single-photon fluorescence decay measurements, Rev. Sci. Instrum. 54, 1148-1156 (1983). 

Further aluminum pour tests were made in a heavy-wall stainless steel tank fitted with Lucite side windows. The tank was supported on a force transducer and pressure transducers were located on either end. In a test, after the spill, there was a predetermined delay and then the wire was exploded. The aluminum usuaUy had puddled on the tank bottom before the wire explosion and steam bubbles could be seen. The shock from the wire explosion usually collapsed the film and, following this, the aluminum expanded. If the shock were sufficiently energetic, the aluminum soon fragmented and expelled the water from the tank in a thermal explosion. In such cases, the force transducers on the bottom ranged from 5 to 10 N sec. (The exploding wire alone led to impulses around 1 N sec.) Efficiencies of an explosion calculated as indicated above were low. 

PVC is accepted commercially as an excellent weathering material. PVC s chemical response to weathering is well understood so that compounds and products can be designed for satisfactory outdoor performance. Products include siding, windows, and doors. 

Figure 7 An end-window photomultiplier tube. Side-window tubes, in which the photocathode is a separate electrode (not window-mounted), are often used in analytical spectrometers...

If you have a pair of polarized sunglasses, you are likely to have seen the effects of tempered glass on rear and side windows of cars. The telltale white or gray spot array pattern is an indication of where the cold air jets were located (see Fig. 1.8). 

Profile extrusion of siding, window frames, gasketing, and other shapes is complicated by the effects of their asymmetry on heating, viscosity, cooling, and dimensional control. This generally requires modification of the die, and vacuum-driven calibration of the extruded product. 

The shop owners, who had suffered a nighttime robbery prior to the fireworks accident, had taken the countermeasures of both locking the back door and also putting iron bars on the door, as well as installing wooden bars on the side window. This was the major factor confining the students inside most of them had to escape through the window by breaking the wooden bars. 

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