218 research outputs found
An Intuitionistic Formula Hierarchy Based on High-School Identities
We revisit the notion of intuitionistic equivalence and formal proof
representations by adopting the view of formulas as exponential polynomials.
After observing that most of the invertible proof rules of intuitionistic
(minimal) propositional sequent calculi are formula (i.e. sequent) isomorphisms
corresponding to the high-school identities, we show that one can obtain a more
compact variant of a proof system, consisting of non-invertible proof rules
only, and where the invertible proof rules have been replaced by a formula
normalisation procedure.
Moreover, for certain proof systems such as the G4ip sequent calculus of
Vorob'ev, Hudelmaier, and Dyckhoff, it is even possible to see all of the
non-invertible proof rules as strict inequalities between exponential
polynomials; a careful combinatorial treatment is given in order to establish
this fact.
Finally, we extend the exponential polynomial analogy to the first-order
quantifiers, showing that it gives rise to an intuitionistic hierarchy of
formulas, resembling the classical arithmetical hierarchy, and the first one
that classifies formulas while preserving isomorphism
Modeling of a Buss-Kneader as a polymerization reactor for acrylates. Part II: Methyl methacrylate based resins
The Buss-Kneader has proven to be a suitable reactor for the polymerization of acrylates. In this second part, the polymerization of methyl methacrylate and the ter- polymerization of methyl methacrylate (MMA), hydroxyethyl methacrylate and n-butylmethacrylate is carried out in a pilot Buss-Kneader. The reactor had to be pressurized up to about 10 bars to avoid evaporation of MMA. Instabilities in output rate and temperature profiles were observed as a result of fluctuating the pressures. Because of good mixing there may be no diffusion limitation for radicals. As a result, even at high conversions, no gel effect was observed
Neurology
Contains reports on seven research projects.U. S. Public Health Service (B-3055-3,U. S. Public Health Service (B-3090-3)U. S. Public Health Service (38101-22)Office of Naval Research (Nonr-1841 (70))Air Force (AF33(616)-7588)Air Force (AFAOSR 155-63)Army Chemical Corps (DA-18-108-405-Cml-942)National Institutes of Health (Grant MH-04734-03
Neurology
Contains research objectives and reports on six research projects.National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-03)U.S. Public Health Service (B-3055-3)U.S. Public Health Service (B-3090-3)U.S. Public Health Service (MH-06175-01A1)Office of Naval Research (Nonr-1841(70))Air Force (AFOSR 155-63)Army Chemical Corps (DA- 18-108-405-CML-942
Radical addition polymerization of acrylates in a Buss-Kneader
The radical addn. co-polymn. of 2-hydroxyethyl methacrylate and Bu acrylate is carried out in a continuously operating Buss-Kneader. To calc. temp. profiles over the length of the kneader the heat balance is solved. For the heat transfer coeff. a model based on the penetration theory is used. This model is exptl. verified. The reaction kinetics of the radical addn. polymn. are studied in a differential scanning calorimeter. The polymn. kinetics are modeled using non-stationary radical concns. The calcd. temp. profiles over the length of the Buss-Kneader are a good approxn. of the exptl. data. [on SciFinder (R)
Successful control of a hospital-wide outbreak of OXA-48 producing Enterobacteriaceae in the Netherlands, 2009 to 2011
Successful control of a hospital-wide outbreak of OXA-48 producing Enterobacteriaceae in the Netherlands, 2009 to 2011
On 31 May 2011, after notification of Klebsiella pneumoniae(KP)(OXA-48);(CTX-M-15) in two patients, nosocomial transmission was suspected in a Dutch hospital. Hospital-wide infection control measures and an outbreak investigation were initiated. A total of 72,147 patients were categorised into groups based on risk of OXA-48 colonisation or infection, and 7,527 were screened for Enterobacteriaceae(OXA-48) by polymerase chain reaction (PCR). Stored KP isolates (n=408) were retrospectively tested for OXA-48 and CTX-M-1 group extended-spectrum beta-lactamases (ESBL). 285 KP isolates from retrospective and prospective patient screening were genotyped by amplified fragment length polymorphism (AFLP). 41 isolates harbouring different Enterobacteriaceae species were analysed by plasmid multilocus sequence typing (pMLST). No nosocomial transmission of Enterobacteriaceae(OXA-48) was detected after 18 July 2011. Enterobacteriaceae(OXA-48) were found in 118 patients (KP (n=99), Escherichia coli (n=56), >= 1 Enterobacteriaceae(OXA-48) species (n=52)),of whom 21 had clinical infections. 39/41 (95%) of OXA-48 containing plasmids were identical in pMLST. Minimum inhibitory concentrations (MICs) of KPOXA-48 and E. coli(OXA-48) for imipenem and meropenem ranged from = 16 mg/L, and 153/157 (97%) had MIC >0.25mg/L for ertapenem. AFLP identified a cluster of 203 genetically linked isolates (62 KPOXA-48;(CTX-M15); 107 KPCTX-M-15; 34 KPOXA-48). The 'oldest' KPCTX-M-15 and KPOXA-48 clonal types originated from February 2009 and September 2010, respectively. The last presumed outbreak-related KPOXA-48 was detected in April 2012. Uncontrolled transmission of KP (CTX-M-15) evolved into a nosocomial outbreak of KPOXA-48; CTX-M15 with large phenotypical heterogeneity. Although the outbreak was successfully controlled, the contribution of individual containment measures and of the hospital relocating into a new building just before outbreak notification was impossible to quantify
Neurology
Contains reports on nineteen research projects.United States Public Health Service (B-3055-3, B-3090-3, 38101-22)United States Navy, Office of Naval Research (Contract Nonr-1841(70))Unites States Air Force (AF33(616)-7588, AFAOSR 155-63)United States Army Chemical Corps (DA-18-108-405-Cml-942)National Institutes of Health (Grant MH-04734-03)National Aeronautics and Space Administration (Grant NsG-496
Naamlijst en verspreidingsgegevens van de Nederlandse bramen (<i>Rubus</i> L. subgenus <i>Rubus</i>)
Physics, Topology, Logic and Computation: A Rosetta Stone
In physics, Feynman diagrams are used to reason about quantum processes. In
the 1980s, it became clear that underlying these diagrams is a powerful analogy
between quantum physics and topology: namely, a linear operator behaves very
much like a "cobordism". Similar diagrams can be used to reason about logic,
where they represent proofs, and computation, where they represent programs.
With the rise of interest in quantum cryptography and quantum computation, it
became clear that there is extensive network of analogies between physics,
topology, logic and computation. In this expository paper, we make some of
these analogies precise using the concept of "closed symmetric monoidal
category". We assume no prior knowledge of category theory, proof theory or
computer science.Comment: 73 pages, 8 encapsulated postscript figure
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