2,799 research outputs found

    Stochastic Mean-Field Theory for the Disordered Bose-Hubbard Model

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    We investigate the effect of diagonal disorder on bosons in an optical lattice described by an Anderson-Hubbard model at zero temperature. It is known that within Gutzwiller mean-field theory spatially resolved calculations suffer particularly from finite system sizes in the disordered case, while arithmetic averaging of the order parameter cannot describe the Bose glass phase for finite hopping J>0J>0. Here we present and apply a new \emph{stochastic} mean-field theory which captures localization due to disorder, includes non-trivial dimensional effects beyond the mean-field scaling level and is applicable in the thermodynamic limit. In contrast to fermionic systems, we find the existence of a critical hopping strength, above which the system remains superfluid for arbitrarily strong disorder.Comment: 6 pages, 6 figure

    Quantum analogue of the Kolmogorov-Arnold-Moser transition in the field induced barrier penetration in a quartic potential

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    Quantum signatures of the Kolmogorov-Arnold-Moser (KAM) transition from the regular to chaotic classical dynamics of a double-well oscillator in the presence of an external monochromatic field of different amplitudes are analysed in terms of the corresponding Bohmian trajectories. It is observed that the classical chaos generally enhances the quantum fluctuations, while the quantum nonclassical effects try to suppress classical stochasticity

    Journey Sustainability Analysis Report

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    This report contains an analysis of the transport emissions and occupancy for the transport network within Manchester. The study aims to identify the differences in travel distance, travel time and CO2 emissions per occupant for different journeys in Manchester using methods in emissions estimation described in the report 12.6.2 Occupancy/Emissions Sustainability Metric Matrix

    Occupancy / Emissions Sustainability Metric Matrix

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    This report investigates occupancy/emission metrics for public and private domestic urban transportation and develops an emissions/sustainability matrix for the future development of a 'Green Travel Planning Tool'. The objective of this research is to 1) Review the current methods of estimating occupancy/emissions for various modes of transportation and to update these for accuracy; 2) Produce a sustainability/emissions matrix; 3) Compare the metrics developed with results from existing door-to-door journey planners producing their own estimates. Existing journey planners providing emission estimates typically use distance, estimated travel time and different modes of transportation as factors. The matrix produced here incorporates multiple additional factors (E.g. travel speed, embodied energy use based on fuel type) in an attempt to accurately estimate emissions per journey. The study includes the following:- 1. Identification of the latest average emissions for each mode of urban transport (normalised by occupancy) 2. A List of emissions occupancy estimation proxies and conversion factors where applicable 3. Identification of measurements and variables required for emissions and occupancy estimates. 4. Study of how existing journey planners produce their emissions results using different metrics. 5. A dynamic matrix that can be used to compute emissions results for new journey planners

    Analysis of Journey Planner Apps and Best Practice Features

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    This report aims to form an investigative report in existing journey planner apps and to identify best practice features. The result of the study will inform subsequent research and design of innovative digital tools to enable greener travel. Key Objectives:- • Select multi-transport journey planner apps. • Identify high level features in journey planners. • Conduct a usability test on each selected app. • Identify best practice qualities and recommendations

    Coupling of proteins to liposomes and their role in understanding delayed type of hypersensitivity in human and mice

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    Liposome-coupled lepromin was found to elicit a 3-week skin reaction in leprosy patients similar to that elicited by whole Mycobacterium leprae. The present study suggests that the presentation of antigens in a specific orientation is necessary for evoking delayed type hypersensitivity response in humans
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