Light transmission technique

The light transmission technique [3] is based on the fact that the fraction of light transmitted through a gas - liquid dispersion is related to the interfacial area and the length of the light pass, irrespective of bubble size. 

Miller and associates (M4) measured the interaction rate in a liquid-liquid two-phase batch reactor by means of a light transmission technique, which has the advantage that it can be used with the aqueous phase or the organic phase dispersed. 

Drop size distribution can be indirectly measured by using the light-transmission technique. When a beam of light is passed through a gas-liquid dispersion, light is scattered by the gas bubbles. It was... 

The light transmission technique is most frequently used for the determination of average bubble size in gas-liquid dispersion. It has the advantages of quick measurement and on-line operation. The probes are usually made of mirror-treated glass rods (Vermeulen et al., 1955), internally blackened tubes with mirrors (Calderbank, 1958), or fiber optic light guide (Hong and Lee, 1983). 

Two-fluid simulations have also been performed to predict void profiles (Kuipers et al, 1992b) and local wall-to-bed heat transfer coefficients in gas fluidized beds (Kuipers et al., 1992c). In Fig. 18 a comparison is shown between experimental (a) and theoretical (b) time-averaged porosity distributions obtained for a 2D air fluidized bed with a central jet (air injection velocity through the orifice 10.0 m/s which corresponds to 40u ). The experimental porosity distributions were obtained with the aid of a nonintrusive light transmission technique where the principles of liquid-solid fluidization and vibrofluidization were employed to perform the necessary calibration. The principal differences between theory and experiment can be attributed to the simplified solids rheology assumed in the hydrodynamic model and to asymmetries present in the experiment. 

Estimate the volume of bubble-free slurry required to obtain a conversion of 30% for a hydrogen feed rate of 100 ft /min (at 60°F and 1 atm). By a light-transmission technique, Calderbank measured gas-liquid interfacial areas of 0.94 to 2.09 cm /cm for bubble sizes likely to be encountered in this system. Suppose for this illustration Mg = 1.0 cm-/cm of bubble-free slurry. The Henry s law constant for hydrogen in toluene at 50°C is 9.4 (g mole/cm )/(g moles/cm ), and its diffusivity is 1.1 x 10 " cm /sec. The density and viscosity of toluene at 50°C are 0.85 g/cm and 0.45 centi-poises, respectively. Equimolal feed rates of ethylene and hydrogen will be used. 

J. T. Worthington, D. R. Massie, K. H. Norris. Light transmission technique for the predicting ripening time for intact green tomatoes. ASAE Paper No. 73-6526, 1973. 

Hao, J.H. and S. Wang. 2003. Studies on Membrane Formation Mechanism by the Light Transmission Technique. I. Journal of Applied Polymer Science 87(2) 174—181. doi 10.1002/app.ll244. 

Visibihty tints are similar to cosmetic tints except that they are significantly lighter ki kitensity. Visible light transmission losses are typically 1—2%. With these tints, the lens is visible ki the lens package and against a variety of surfaces, and the lens is easier to handle. The tint can be added as cosmetic tints, with a masking technique to produce a clear annulus, or the whole lens can be tinted. 

Ultem PEI resins are amber and amorphous, with heat-distortion temperatures similar to polyethersulfone resins. Ultem resins exhibit high modulus and ate stiff yet ductile. Light transmission is low. In spite of the high use temperature, they are processible by injection mol ding, stmctural foam mol ding, or extmsion techniques at moderate pressures between 340 and 425°C. They are inherently flame retardant and generate Httie smoke dimensional stabiUties are excellent. Large flat parts such as circuit boards or hard disks for computers can be injection-molded to maintain critical dimensions. 

Compared to other biomolecular systems, lipid bilayer membranes and lyotropic lipid mesophases in general have been shown to respond most sensitively to hydrostatic pressure. The methods used in the high pressure studies have mainly included X-ray and neutron diffraction, fluorescence, IR and Raman spectroscopy, light transmission and volumetric measurements. Only a small amount of work has been performed using NMR techniques combined with high-pressure, a field which was pioneered by Jonas and co-workers " although the method is very powerful, non-invasive and allows the study of a series of structural and dynamic properties of the systems in detail and with atomic resolution. 

Metal-oxide-based electrochromic systems are especially interesting for the development of electrochromic windows because they mostly switch from a transparent state to a dark colored state [38,39]. In addition, their relatively slow response times are acceptable for this kind of application, possibly even preferable from an aesthetic point of view. Again, W03 has seen the most use in the development of actual devices. Several different deposition techniques have been applied. For example, a prototype electrochromic window based on W03 with reasonable dimensions (0.7 X 1 m) has been assembled that reduces light transmission by a factor of 4 in its colored state [28]. 

To calculate the gas absorption rate qL for Eq. (9.7), we need to know the gas-liquid interfacial area, which can be measured employing several techniques such as photography, light transmission, and laser optics. 

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