7,757 research outputs found

    PROCURING BULK PETROLEUM FOR THE FEDERAL GOVERNMENT: WHY VENDORS’ OFFERS ARE RATED TECHNICALLY UNACCEPTABLE

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    Every fiscal year, DLA Energy procures global military jet fuel and marine diesel fuel requirements through four major purchase programs: Inland East Gulf Coast; Rocky Mountain West; Atlantic, Europe and Mediterranean; and Western Pacific. DLA Energy’s Bulk Petroleum Products Division oversees these procurements and delivers contracting support for all bulk petroleum requirements. Offerors develop proposals and submit proposals, and when proposals are evaluated, some are determined technically unacceptable based on the evaluation factors. When offerors’ proposals are deemed technically unacceptable, that reduces the level of competition for that procurement and competition is reduced, resulting in a greater challenge for DLA Energy to award contracts based on fair and reasonable prices. The more proposals that are deemed technically acceptable, the greater the competition in the procurement, which results in DLA Energy being better able to support its mission. The purpose of this research is to provide an analysis of the reasons why offerors’ proposals are deemed technically unacceptable during proposal evaluation of the contract source selection. Based on the analysis, this research provides recommendations for how DLA Energy could improve its procurement of bulk petroleum. This also helps inform the industry by making recommendations of how to improve their proposals so that they can be technically acceptable.Outstanding ThesisCivilian, Defense Logistics Agency EnergyApproved for public release. Distribution is unlimited

    Quantum and Classical in Adiabatic Computation

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    Adiabatic transport provides a powerful way to manipulate quantum states. By preparing a system in a readily initialised state and then slowly changing its Hamiltonian, one may achieve quantum states that would otherwise be inaccessible. Moreover, a judicious choice of final Hamiltonian whose groundstate encodes the solution to a problem allows adiabatic transport to be used for universal quantum computation. However, the dephasing effects of the environment limit the quantum correlations that an open system can support and degrade the power of such adiabatic computation. We quantify this effect by allowing the system to evolve over a restricted set of quantum states, providing a link between physically inspired classical optimisation algorithms and quantum adiabatic optimisation. This new perspective allows us to develop benchmarks to bound the quantum correlations harnessed by an adiabatic computation. We apply these to the D-Wave Vesuvius machine with revealing - though inconclusive - results

    Spin-Polarized Electrons in Monolayer MoS2_2

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    The optical susceptibility is a local, minimally-invasive and spin-selective probe of the ground state of a two-dimensional electron gas. We apply this probe to a gated monolayer of MoS2_2. We demonstrate that the electrons are spin polarized. Of the four available bands, only two are occupied. These two bands have the same spin but different valley quantum numbers. We argue that strong Coulomb interactions are a key aspect of this spontaneous symmetry breaking. The Bohr radius is so small that even electrons located far apart in phase space interact, facilitating exchange couplings to align the spins

    Relativistic Two-Body Processes in Axial-Charge Transitions

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    We study the contribution of two-body meson-exchange processes to axial charge transitions for nuclei in the lead, tin and oxygen regions. We conduct calculations in the Dirac-Hartree (the Walecka model) and the relativistic Hartree (where the full one-nucleon-loop effects are included) approximations. We present results indicating that one- and two-body processes enhance the matrix elements of the axial-charge operator by some (100+-20)% in all three regions studied. This agrees well with the fit of eighteen first-forbidden beta-decay transitions conducted by Warburton in the lead region. We also discuss some sensitivities present in the calculation.Comment: 23 pages, RevTeX format, 5 PostScript figures available on reques

    New calculations of the PNC Matrix Element for the JπTJ^{\pi}T 0+1,01^{+}1,0^{-}1 doublet in 14^{14}N

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    A new calculation of the predominantly isoscalar PNC matrix element between the JπTJ^{\pi}T 0+1,010^{+}1,0^{-}1 (Ex_{x} \approx 8.7 MeV) states in 14^{14}N has been carried out in a (0+1+2+3+4)ω\hbar \omega model space with the Warburton-Brown interaction. The magnitude of the PNC matrix element of 0.22 to 0.34 eV obtained with the DDH PNC interaction is substantially suppressed compared with previous calculations in smaller model spaces but shows agreement with the preliminary Seattle experimental data. The calculated sign is opposite to that obtained experimentally, and the implications of this are discussed.Comment: REVTEX, 28 page

    Quantum correlations in position, momentum, and intermediate bases for a full optical field of view

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    We report an eight-element, linear-array, single-photon detector that uses multiple fibers of differing lengths coupled to a single detector, the timing information from which reveals the position in which the photon was measured. Using two such arrays and two detectors we measure the correlations of photons produced by parametric downconversion, without recourse to mechanical scanning. Spatial light modulators acting as variable focal length lenses positioned between the downconversion crystal and the arrays allow us to switch between measurement of position, transverse momentum, or intermediate bases. We observe the product of the variances of the conditional probabilities for position and momentum to be more than an order of magnitude below the classical limit, realizing a full-field demonstration of the Einstein-Podolsky-Rosen paradox. Such, multistate measurement technologies allow access to the higher information content of the photon based upon spatial modes

    Fano resonance resulting from a tunable interaction between molecular vibrational modes and a double-continuum of a plasmonic metamolecule

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    Coupling between tuneable broadband modes of an array of plasmonic metamolecules and a vibrational mode of carbonyl bond of poly(methyl methacrylate) is shown experimentally to produce a Fano resonance, which can be tuned in situ by varying the polarization of incident light. The interaction between the plasmon modes and the molecular resonance is investigated using both rigorous electromagnetic calculations and a quantum mechanical model describing the quantum interference between a discrete state and two continua. The predictions of the quantum mechanical model are in good agreement with the experimental data and provide an intuitive interpretation, at the quantum level, of the plasmon-molecule coupling
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