1,650 research outputs found

    Many-Body Interactions in a Sample of Ultracold Rydberg Atoms with Varying Dimensions and Densities

    Get PDF
    Ultracold highly excited atoms in a magneto-optical trap (MOT) are strongly coupled by the dipole-dipole interaction. We have investigated the importance of many-body effects by controlling the dimensionality and density of the excited sample. We excited three different cylindrical volumes of atoms in the MOT to Rydberg states. At small radius, where the sample is nearly one-dimensional, many-body interactions are suppressed. At larger radii, the sample becomes three-dimensional and many-body effects are apparent

    The Effect on Stockholder’s Wealth on Critical Systems Failure and Remedy: The Boeing 787 Case

    Get PDF
    In this paper we analyze the effect of Boeing Dreamliner 787’s battery problems on stockholder wealth. Using the event study methodology, we show that the recall in January of 2013 initially caused the company’s cumulative abnormal returns to fall by almost 4% in four trading days after the recall. This was followed by an announcement by two major airlines to ground all of the 787 Dreamliner jets. The FAA also ordered all US airlines to ground their 787s and announced an investigation to review all critical systems of 787s. However within four months of the investigation, FAA approved Boeing’s revisions to its 787 design. This caused Boeing’s abnormal returns to rise by almost 2%. On April 24th Boeing reported it’s greater than expected quarterly results which caused its abnormal returns to rise by an additional 3%. The Boeing case provides us an opportunity to study how critical mistakes can change the value of a manufacturer. It also shows how critical it is for the company to redeem itself by quickly addressing a crisis situation

    Prevention of endotoxin-induced uveitis in rabbits by Triphala, an Ayurvedic formulation

    Get PDF
    Purpose: Triphala (TA) is an Ayurvedic formulation used to treat various disorders. The present study was designed to investigate the anti-inflammatory effect of TA aqueous extract on experimental uveitis in the rabbit. Methods: Anterior uveitis was induced in rabbits by intravitreal injection of lipopolysaccharide from Eschericha coli after pretreatment with TA aqueous extract. Subsequently the anti-inflammatory activity of TA was evaluated by grading the clinical signs and estimating the inflammatory cell count, protein, and TNF-α level in the aqueous humour. Results: The anterior segment inflammation in the control group was significantly higher than in TA and prednisolone treated groups, as observed by clinical grading. The inflammatory cell count in the control group was 31.23 ± 0.80 × 105cells/ml, whereas it was 3.29 ± 0.47 × 105cells/ml (P < 0.0001 vs. control) and 1.31 ± 0.31 × 105 (P < 0.0001 vs. control) cells/ml in the TA and prednisolone treated groups, respectively. The protein content of the aqueous humour was 15.43 ± 0.54, 3.13 ± 0.35 (P < 0.0001 vs. control), and 1.96 ± 0.39 (P < 0.0001 vs. control) mg/ml in the control, TA and prednisolone treated groups respectively. The aqueous TNF- α level in the control group was 942.20 ± 6.46 pg/ml and was 261.30 ± 13.60 (P < 0.001 vs. control) and 104.00 ± 4.50 (P < 0.0001 vs. control) pg/ml in the TA and prednisolone treated groups, respectively. \ud Conclusions: Topical administration of aqueous extract of TA prevented uveitis in endotoxin-induced experimental rabbits.\u

    Many-body Interactions in a Sample of Ultracold Rydberg Atoms with Varying Dimensions and Densities

    Get PDF
    Ultracold highly excited atoms in a magneto-optical trap (MOT) are strongly coupled by the dipole-dipole interaction. We have investigated the importance of many-body effects by controlling the dimensionality and density of the excited sample. We excited three different cylindrical volumes of atoms in the MOT to Rydberg states. At small radius, where the sample is nearly one-dimensional, many-body interactions are suppressed. At larger radii, the sample becomes three-dimensional and many-body effects are apparent

    Discrete series of fusion algebras

    Get PDF
    We show that the left regular representation of a countably infinite (discrete) group admits no finite-dimensional invariant subspaces. We also discuss a consequence of this fact, and the reason for our interest in this statement. We then formally state, as a 'conjecture', a possible generalisation of the above statement to the context of fusion algebras. We prove the validity of this conjecture in the case of the fusion algebra arising from the dual of a compact Lie group. We finally show, by example, that our conjecture is false as stated, and raise the question of whether there is a 'good' class of fusion algebras, which contains (a) the two 'good classes' discussed above, namely, discrete groups and compact group duals, and (b) only contains fusion algebras for which the conjecture is valid
    • …
    corecore