6,385 research outputs found
A novel optical passive router ring architecture using MAGNet protocol
This paper introduces a family of bidirectional multi-fibre passive photonic ring architectures that may serve as a high-capacity network backbone for supporting next-generation data-centric services. We introduce a novel dual-router node design that avoids several non-ideal routing phenomena typically associated with passive networks based on cyclic graphs. Our design also achieves the requisite single-hop full-mesh connectivity needed for arbitrary node-to-node communications. A ring enlargement strategy is presented that allows this architecture to scale across a wide range of networking domains. A medium access protocol will also briefly elaborated
Effects of mechanically separated dairy cow slurry on grazing performance
No abstract available
Weak-scale hidden sector and electroweak Q-balls
By extending the scalar sector of the Standard Model (SM) by a U(1) singlet,
we show that the electroweak symmetry breaking enables the formation of a
stable, electrically neutral, colorless Q-ball which couples to the SM particle
spectrum solely through the Higgs boson. This Q-ball has mainly weak and
gravitational interactions, and behaves as a collection of weakly interacting
massive particles. Therefore, it can be a candidate for the dark matter in the
universe.Comment: 10 pages, typos corrected, new references adde
Elastic neutron scattering in Quantum Critical Antiferromagnet CrV
We have performed elastic neutron scattering studies of the quantum critical
antiferromagnet CrV. We have found that unlike pure Cr,
which orders at two incommensurate wavevectors, CrV orders
at four incommensurate and one commensurate wavevectors. We have found strong
temperature dependent scattering at the commensurate and incommensurate
wavevectors below 250 K. Results indicate that the primary effect of V doping
on Cr is the modification of the nesting conditions of the Fermi surface and
not the decreasing of the Neel temperature.Comment: 2 pages, 2 figures, submitted to SCES07 (to be published in Physica
B), typos correcte
Ferromagnetic/III-V semiconductor heterostructures and magneto-electronic devices
The interface magnetic and electronic properties of two Fe/III-V semiconductor systems, namely Fe/GaAs and Fe/InAs, grown at room temperature have been studied. A "magnetic interface", which is essential for the fabrication of magneto-electronic (ME) devices, was realized in both Fe/GaAs and Fe/InAs systems with suitable substrate processing and growth conditions. Furthermore, Fe/InAs was shown to have favorable interface electronic properties as Fe forms a low resistance ohmic contact on InAs. Two prototypes of ME device based on Fe/InAs are also discussed
An evaluation of combined geophysical and geotechnical methods to characterize beach thickness
Beaches provide sediment stores and have an important role in the development of the coastline in response to climate change. Quantification of beach thickness and volume is required to assess coastal sediment transport budgets. Therefore, portable, rapid, non-invasive techniques are required to evaluate thickness where environmental sensitivities exclude invasive methods. Site methods and data are described for a toolbox of electrical, electromagnetic, seismic and mechanical based techniques that were evaluated at a coastal site at Easington, Yorkshire. Geophysical and geotechnical properties are shown to be dependent upon moisture content, porosity and lithology of the beach and the morphology of the beach–platform interface. Thickness interpretation, using an inexpensive geographic information system to integrate data, allowed these controls and relationships to be understood. Guidelines for efficient site practices, based upon this case history including procedures and techniques, are presented using a systematic approach. Field results indicated that a mixed sand and gravel beach is highly variable and cannot be represented in models as a homogeneous layer of variable thickness overlying a bedrock half-space
Australian Group on Antimicrobial Resistance (AGAR) Australian Staphylococcus aureus Sepsis Outcome Programme (ASSOP) Annual Report 2017
From 1 January to 31 December 2017, 36 institutions around Australia participated in the Australian Staphylococcus aureus Sepsis Outcome Programme (ASSOP). The aim of ASSOP 2017 was to deter¬mine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that are anti¬microbial resistant, with particular emphasis on susceptibility to methicillin and to characterise the molecular epidemiology of the methicillin-resistant isolates. A total of 2,515 S. aureus bacteraemia episodes were reported, of which 77% were community-onset. Approximately one in five S. aureus (19.0%) were methicillin resistant. The 30-day all-cause mortality associated with methicillin-resistant SAB was 18.7% which was significantly higher than the 14.0% mortality associated with methicillin-susceptible SAB. With the exception of the β-lactams and erythromycin, antimicrobial resistance in methicillin-susceptible S. aureus was rare. However in addition to the β-lactams approximately 42% of methicillin-resistant S. aureus (MRSA) were resistant to erythromycin and ciprofloxacin and approxi¬mately 14% resistant to co-trimoxazole, tetracycline and gentamicin. When applying the EUCAST breakpoints teicoplanin resistance was detected in five S. aureus isolates. Resistance was not detected for vancomycin and linezolid. Resistance to non-beta-lactam antimicrobials was largely attributable to two healthcare-associated MRSA clones: ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA). ST22-IV [2B] (EMRSA-15) is the predominant healthcare-associated clone in Australia. Seventy-five percent of methicillin-resistant SAB were due to community-associated clones. Although polyclonal approximately 74% of community-associated clones were characterised as ST93-IV [2B] (Queensland CA-MRSA), ST5-IV [2B], ST45-VT [5C2&5] and ST1-IV [2B]. CA-MRSA, in particular the ST45-VT [5C2&5] clone has acquired multiple antimicrobial resistance determinants including ciprofloxacin, erythromycin, clindamycin, gentamicin and tetracycline. ST45-VT [5C2&5] accounted for 12.8% of CA-MRSA. As CA-MRSA is well established in the Australian community it is important antimicrobial resistance patterns in community- and healthcare-associated SAB is monitored as this information will guide therapeutic practices in treating S. aureus sepsis
Fat and Thin Fisher Zeroes
We show that it is possible to determine the locus of Fisher zeroes in the
thermodynamic limit for the Ising model on planar (``fat'') phi4 random graphs
and their dual quadrangulations by matching up the real part of the high- and
low-temperature branches of the expression for the free energy. Similar methods
work for the mean-field model on generic, ``thin'' graphs. Series expansions
are very easy to obtain for such random graph Ising models.Comment: 3 pages, LaTeX, Lattice2001(surfaces
Chiral rings and GSO projection in Orbifolds
The GSO projection in the twisted sector of orbifold background is sometimes
subtle and incompatible descriptions are found in literatures. Here, from the
equivalence of partition functions in NSR and GS formalisms, we give a simple
rule of GSO projection for the chiral rings of string theory in \C^r/\Z_n,
. Necessary constructions of chiral rings are given by explicit mode
analysis.Comment: 24 page
Quantum-classical transition of the escape rate of uniaxial antiferromagnetic particles in an arbitrarily directed field
Quantum-classical escape rate transition has been studied for uniaxial
antiferromagnetic particles with an arbitrarily directed magnetic field. In the
case that the transverse and longitudinal fileds coexist, we calculate the
phase boundary line between first- and second-order transitions, from which
phase diagrams can be obtained. It is shown that the effects of the applied
longitudinal magnetic field on quantum-classical transition vary greatly for
different relative magnitudes of the non-compensation.Comment: to be appeared in Phys. Rev.
- …