Luminometers

In order to maintain high energy efficiency and ensure a long service life of the materials of construction in the combustion chamber, turbine and jet nozzle, a clean burning flame must be obtained that minimizes the heat exchange by radiation and limits the formation of carbon deposits. These qualities are determined by two procedures that determine respectively the smoke point and the luminometer index. 

The luminometer index (ASTM D 1740) is a characteristic that is becoming less frequently used. It is determined using the standard lamp mentioned above, except that the lamp is equipped with thermocouples allowing measurement of temperatures corresponding to different flame heights, and a photo-electric cell to evaluate the luminosity. The jet fuel under test is compared to two pure hydrocarbons tetraline and iso-octane to which are attributed the indices 0 and 100, respectively. The values often observed in commercial products usually vary between 40 and 70 the official specification is around 45 for TRO. 

Figure 5.13 shows that the luminometer index depends directly on the mono-aromatic and di-aromatic contents. For this reason, the specifications... 

Luminometer index for the combustion flame of a jet fuel as a function of its volumetric content in aromatics. 

Fig. 6. Luminometer ratings of hydrocarbons (7), O, / -paraffins V, /-paraffins , cyclopataffins A, olefins , aromatics.

For monitoring the day-by-day fluctuation of the sensitivity of luminometer, the radioactive luminescence standard described by Hastings and Weber (1963), and Hastings and Reynolds (1966) is most useful and convenient (see also Section 2.6). 

O Kane, D. J., and Lee, J. (2000). Absolute calibration of luminometers with low-level light standards. Method. Enzymol. 305 87-96. 

Stanley, P. E. (1992). A survey of more than 90 commercially available luminometers and imaging devices for low-light measurements of chemiluminescence and bioluminescence, including instruments for manual, automatic and specialized operation, for HPLC, LC, GLC and microtiter plates. Part I descriptions. T. Biolumin. Chemilumin. 7 77-108. 

Stanley, P. E. (1999). Commercially available luminometers and imaging devices for low-light level measurements and kits and reagents utilizing... 

Comprehensive kits are available to analysts, bacteriologists and research workers to perform the determination of ATP. They include, or are backed by, special lightmeasuring equipment (luminometers) to estimate light emission and follow its extinction. 

Alkaline phosphatase-labeled probes are synthesized so that 18 bases are complementary to sequences on the arms of the bDNA. Three hybridization sites are located on each branch for a total binding capacity of 45 labeled probes per bDNA molecule. The alkaline phosphatase catalyzes the dephosphorylation of chemiluminescent substrate, dioxetane (Lumi-Phos Plus, Lumigen, Detroit, MI). The intensity of the light emission is measured with a plate luminometer as relative luminescent units. 

Chiron provides a microwell plate heater, a luminometer, and data management software. The plate heater is specially designed to provide precise control of the hybridization temperature (0 0.5°C) and to distribute heat evenly throughout the microwell plate. The luminometer maintains a temperature of 37°C and accommodates the 96-well plates. The data management software runs on an IBM PC or compatible computer with a minimum of 80386,16-Mhz microprocessor, 2 Mb of RAM, monitor, mouse, compatible printer, MS DOS (version 5.0 or greater), and Windows (version 3.1 or greater). 

In the Hybrid-Capture assay (Digene), a full-length RNA probe is hybridized to denatured HBV DNA in solution and the hybrids are captured on the surface of a tube coated with anti DNA RNA hybrid antibody. The bound hybrids are reacted with antihybrid antibody labeled with alkaline phosphatase. A chemiluminescent substrate is converted to a luminescent compound by the bound alkaline phosphatase. Light emission is measured in a luminometer and the concentration of HBV DNA, in pg/ml, is determined from a standard curve. The concentrations of the standards are determined spectrometrically (A260nm/A280nm). 

A spectro-radiometer-luminometer for chemiluminescence and fluorescence quantum yield studies has been described by B. G. Roberts and H. C. Hirt 187>. To obtain emission spectra from very weak chemiluminescence reactions, a large-aperture spectrograph combined with a sensitive image-intensifier tube has been used68 this was developed from a device previously constructed by Bass and Kessler 188>. With it, it was possible to record the very weak emission of singlet oxygen dimer... 

According to Campbell [1] there are four basic requirements for the detector, which constitutes the critical part of the luminometer ... 

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