John W. Lyons

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he U.S. Government agency NIST has recently proposed a public key digital signature standard [3, 4]. Although the proposal is nominally only "for government use" such a proposal, if adopted, would likely have an effect on commercial cryptography as well. In this note I review and comment on NIST's proposal. (More correctly, it should be called the NIST/NSA(More)
The need to share complex product data across multiple enterprises, using different computing systems and networks is growing. The ISO Standard for the Exchange of Product Model Data (STEP) addresses this need by providing information models which clearly and unambiguously describe this data for different enterprise applications. The validity of these(More)
Recent advances in catalyst technology have enabled the synthesis of olefin block copolymers (OBC). One type is a "hard-soft" OBC with a high density polyethylene (HDPE) block and a relatively low density polyethylene (VLDPE) block targeted as thermoplastic elastomers. Presently, one of the major challenges is to fractionate HDPE segments from the other(More)
A fundamental study of the separation of homopolymers from polystyrene-block-polymethylmethacrylate (PS-b-PMMA) by liquid chromatography with preloaded discrete and continuous adsorption promoting barriers was performed. The impact of barrier composition on the separation of block copolymers (BCP) was studied by a dual detection (ultraviolet (UV) and(More)
Chemical composition distribution (CCD) is a fundamental metric for representing molecular structures of copolymers in addition to molecular weight distribution (MWD). Solvent gradient interaction chromatography (SGIC) is commonly used to separate copolymers by chemical composition in order to obtain CCD. The separation of polymer in SGIC is, however, not(More)
Size-exclusion chromatography (SEC) coupled with multi-angle laser light scattering (MALLS) and differential refractive index (DRI) detectors was employed for determination of the molecular weight distributions (MWD) of methylcellulose ethers (MC) and hydroxypropyl methylcellulose ethers (HPMC) having weight-average molecular weights (Mw) ranging from 20 to(More)