Evaluating Suppliers of Complex Systems: A Multiple Criteria Approach

Organizations are frequently required to make long-term strategic choices regarding the design and manufacture of innovative process equipment and systems which address future needs. An important consideration in such choices is the evaluation of the unique capabilities of available suppliers. Typically, such evaluations must be made relative to multiple attributes or criteria. This paper examines one such supplier evaluation process in the context of a major international manufacturer of telecommunication equipment. The ad hoc method used by the organization to evaluate the multiple factors involved is presented, and an alternative, structured approach to deal with the multiple factors is then discussed.     

A capping methodology for the synthesis of lower mu-oxo-phthalocyaninato silicon oligomers

A mixed condensation of a substituted and unsubstituted silicon phthalocyanine monomer, in which the former serves as a "cap" to a growing oligomeric chain, provides unprecedented access to a mixed dimer, trimers, and a tetramer. An important element of product control can be achieved by changing the ratio of the precursor monomers.     

Electron spin resonance of an irradiated single crystal of maleic acid

Electron spin resonance spectroscopy has been used to investigate radiation damage in an irradiated single crystal of maleic acid. At least two stable radicals are produced by the radiation. One of these radicals is probably HOOC-H₂C-CH-COOH. Another species, possibly of the form HOOC-RCH-CH-COOH, has also been observed.

Radical yields have been measured for the isomeric maleic and fumaric acids. The G-values are 0.1 for maleic acid and 0.06 for fumaric acid.     

Coupling of counterpropagating light waves in low-symmetry photorefractive crystals

Coupling of two counterpropagating coherent light waves in tin hypothiodiphosphate (Sn₂P₂S₆, SPS) is usually strongly inhibited because of severe space charge limitations. Analysis of two-beam coupling gain is performed for different orientations of the grating vector in this monoclinic crystal that takes into account the anisotropy of dielectric permittivity. Gain enhancements are predicted and demonstrated experimentally for several nontraditional orientations of counterpropagating waves.