Hydroxymethylated Resorcinol Coupling Agent for Enhanced Durability of Bisphenol-A Epoxy Bonds to Sitka Spruce

Epoxy adhesives can develop bonds to wood that are as strong as the wood itself, but only if the bonds remain dry. Once exposed to repeated water soaking and severe stresses from drying, epoxy bonds delaminate and fail to meet requirements for structural wood adhesives intended for exterior exposure. A new hydroxymethylated resorcinol (HMR) coupling agent, applied to lumber surfaces before bonding, chemically couples both epoxy adhesive and lignocellulosics of wood to produce bonds to Sitka spruce that are extraordinarily resistant to delamination. In this report, we explain and demonstrate the nature of this coupling agent and the mechanism by which it enhances the durability of bonds of a bisphenol-A epoxy adhesive to wood. When diluted with benzyl alcohol, an epoxy adhesive developed structural bonds in HMR-primed lumber laminates that met the 5% maximum delamination requirement of ASTM Specification D 2559. The USDA Forest Service has applied for a patent for this invention

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Total photoproduction cross-section measurement at HERA energies

We present first results on the total photoproduction cross section measurement with the H1 detector at HERA. The data were extracted from low Q2 collisions of 26.7 GeV electrons with 820 GeV protons. The γp total cross section has been measured by two independent methods in the γp center of mass energy range from 90 to 290 GeV. For an average center of mass energy of 195 GeV a value of σtot (γp) = 159 ± 7 (stat.) ± 20 (syst.) μb was obtained. © 1993.0320 auteursSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Measurement of the hadronic final state in deep inelastic scattering at HERA

We report on the first experimental study of the hadronic final state in deep inelastic electron-proton scattering with the H1 detector at HERA. Energy flow and transverse momentum characteristics are measured and presented both in the laboratory and in the hadronic center of mass frames. Comparison is made with QCD models distinguished by their different treatment of parton emission

A search for leptoquarks, leptogluons and excited leptons in H1 at HERA

A direct search for new particles in the H1 experiment at HERA is presented for masses ranging from 35 GeV up to ∼ 250 GeV. The data sample of 24 nb−1 accumulated during the first year of operation was analysed for signatures of scalar and vector leptoquarks, leptogluons, excited electrons and excited neutrinos with flavours of the first generation. No evidence for the production of such particles was found in various possible decay channels. Rejection limits are derived