1,335 research outputs found
Preparation of highly fluorinated diols containing ether linkages.
Hydroxy-terminated perfluoroethers and polyurethane resins derived from ethers have outstanding chemical resistance and good thermal properties. They can be used as potting compounds, coatings, and seals. The hydroxy-terminated ethers serve as intermediates in the synthesis of highly fluorinated elastomers and adhesives
Preparation of highly fluorinated polyurethanes
New polyurethanes, formed from a reaction of a prepolymer diol and a perfluorinated diisocyanate, are nonflammable and possess high corrosion resistance and good low temperature flexibility. Polymer hardness increases rapidly with increasing ratio of diisocaynate to diol, but its glass transition temperature is not adversely affected
Hydroxy terminated perfluoro ethers Patent
Chemical synthesis of hydroxy terminated perfluoro ethers as intermediates for highly fluorinated polyurethane resin
Highly fluorinated polyurethanes
The reaction perfluorinated hydroxyl terminated polyether with diisocyanate to form polyurethane is discussed. Data are given on the resin's oxidation stability, chemical resistance, and low temperature flexibility
Preparation of perfluoropolyether prepolymers
Fluorinated prepolymers are used to generate highly fluorinated polymers which possess most of the desirable properties of polytetrafluoroethylene, such as nonflammability and high corrosion resistance, while retaining good low temperature flexibility
Stability of NLO Global Analysis and Implications for Hadron Collider Physics
The phenomenology of Standard Model and New Physics at hadron colliders
depends critically on results from global QCD analysis for parton distribution
functions (PDFs). The accuracy of the standard next-to-leading-order (NLO)
global analysis, nominally a few percent, is generally well matched to the
expected experimental precision. However, serious questions have been raised
recently about the stability of the NLO analysis with respect to certain
inputs, including the choice of kinematic cuts on the data sets and the
parametrization of the gluon distribution. In this paper, we investigate this
stability issue systematically within the CTEQ framework. We find that both the
PDFs and their physical predictions are stable, well within the few percent
level. Further, we have applied the Lagrange Multiplier method to explore the
stability of the predicted cross sections for W production at the Tevatron and
the LHC, since W production is often proposed as a standard candle for these
colliders. We find the NLO predictions on sigma_W to be stable well within
their previously-estimated uncertainty ranges.Comment: 24 pages, 11 figures. Minor changes in response to JHEP referee
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Exotic quark effects on the Higgs sector of the USSM at the LHC
The Higgs sector of the U(1)-extended supersymmetric model is studied with
great detail. We calculate the masses of the Higgs bosons at the one-loop
level. We also calculate at the one-loop level the gluon-involving processes
for the productions and decays of the scalar Higgs bosons of the model at the
energy of the CERN Large Hadron Collider (LHC), where the radiative corrections
due to the loops of top, bottom, and exotic quarks and their scalar partners
are taken into account. We find that the exotic quark and exotic scalar quarks
in the model may manifest themselves at the LHC, since the production of the
heaviest scalar Higgs boson via gluon fusion processes is mediated virtually by
the loops of exotic quark and exotic scalar quarks, for a reasonable parameter
set of the model.Comment: 36 pages, 13 figures, JP
Termination Casts: A Flexible Approach to Termination with General Recursion
This paper proposes a type-and-effect system called Teqt, which distinguishes
terminating terms and total functions from possibly diverging terms and partial
functions, for a lambda calculus with general recursion and equality types. The
central idea is to include a primitive type-form "Terminates t", expressing
that term t is terminating; and then allow terms t to be coerced from possibly
diverging to total, using a proof of Terminates t. We call such coercions
termination casts, and show how to implement terminating recursion using them.
For the meta-theory of the system, we describe a translation from Teqt to a
logical theory of termination for general recursive, simply typed functions.
Every typing judgment of Teqt is translated to a theorem expressing the
appropriate termination property of the computational part of the Teqt term.Comment: In Proceedings PAR 2010, arXiv:1012.455
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