Alternative methods capability

The results and discussion section is divided into two parts. The first part deals with direct laser flash photolysis of the MDI-PUE polymer and appropriate small molecule models. The transient spectra generated by direct excitation of the polyurethane are interpreted by consideration of the primary photochemical reactions of the carbamate moiety. The second part describes results obtained by production of a radical transient species which is capable of abstracting labile hydrogens from the polyurethane. This latter procedure represents an alternative method for production of the transient species which were obtained by direct excitation. 

Ideally an absolute method, capable of measuring F accurately should be used since this is not possible, an alternative approach is to quantify in a reproducible way the potential of the liquid phase for... 

All of these problems have led researchers at the SRRC to concentrate on three areas of airborne cotton dust measurements. These include a) analytical (theoretical) modeling of the performance characteristics of the VE b) experimental measurements of the VE s aerodynamic flow characteristics and c) development of an alternate air sampling method capable of accurately measuring lint-free, airborne, respirable cotton dust. 

It justified the choice of chemical flue gas treatment by the potential user based upon its capability to bring emissions under control within a short time span at low cost. Both capital and operating costs were shown to be modest when compared to alternate methods, such as a new or retrofitted electrostatic precipitator or baghouse. 

Trivalent phosphorus compounds are capable of removing vicinal halogens from organic compounds and thus represent a useful alternative method to dehalogenations with metals. Phosphorus agents employed include triphenylphosphane,112 and phosphorus acid esters (triethyl phosphite154 and tributyl phosphite155) and amides [tris(dimethylamino)phosphane 56 and tris(diethylamino)phosphane 57,158]. 

In the following, each step will be described, both for the AP-CVD and for the LP-CVD cases. The results presented are focused on those properties of ZnO films that are useful for thin film solar cell applications, i.e., transparency, conductivity, and light scattering capability. The last part of paragraph 6.2 comments briefly on alternative methods of CVD processes that have been investigated for ZnO deposition (PE-CVD, photo-CVD,. ..). 

Zinc is used in ointments and eye-lotions and is a constituent of different forms of insulin. In the former type of applications zinc oxide, zinc stearate and zinc undecanoate may be encountered in a variety of creams, ointments and pastes. Moody and Taylor [104] dissolved the residue from such samples after ether extraction (lg in 5 ml ether) in concentrated hydrochloric acid. After dilution, the determination can be completed at 213.9 nm in the air/acetylene flame where interferences are not normally encountered. Various analytical techniques for determining zinc in insulin injections have been critically compared [105] atomic absorption was preferred as being accurate, fast and precise. Spielhotz and Toralballa [106] reported a method capable of determining low levels of zinc in insulin. The sample (5 mg) was suspended in water (10 ml), 1 drop of 6M hydrochloric acid was added to effect dissolution. After making up to 50 ml the determination was completed using an air/acetylene flame. Alternatively protamine insulin solution (1 ml) may be diluted to 50 ml after the addition of 1 drop of acid. 

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