82,140 research outputs found

    A Letter to John W. Carlin

    Get PDF
    At the end of October, the ADE Council learned that the agenda for the November 13 meeting of Commissioners of the National Historical Publications and Records Commission would include a plan for ranking ongoing NHPRC-funded editorial projects with an eye for possible curtailment of funds. Such a plan would have gone into effect only in case of financial emergency, and it would have applied only to the second tier of projects whose grant applications are considered in the spring, not the first tier Founding Fathers editions. Even so, the Council felt it wise to put the Association for Documentary Editing on record as opposing this measure, and the following covering letter and resolutions were approved and sent to NHPRC Commission Chair John W. Carlin on November 8, over the signature of ADE President Mary-Jo Kline

    Antenna Impedance in a Warm Plasma

    Get PDF
    Impedance of biconical and cylindrical dipoles in warm isotropic plasm

    Thallium and its contents in Remata carbonate rocks

    Get PDF
    The article presents at first the list of thallium own minerals and its isomorphic content in other minerals, especially in Slovakian ore deposits. This trace element was found in numerous dolomite-rock samples from Remata massif near HandlovĂĄ. An interesting level of Tl content was analyzed in nonsilicified rocks; the highest content of Tl (and Ag) are along the E W line of disturbance. The presence of thallium in some limonitic aggregates in close Kremnica-gold deposit indicate any continuous relation. Some similarities to type gold deposits Carlin ( USA ) are discussed, even if no gold and discrete thallium phases were in Remata determined yet

    Competition, restructuring and firm performance: evidence of an inverted-U relationship from a cross-country survey of firms in transition economies

    Get PDF
    This paper examines the importance of competition in the growth anddevelopment of firms. We draw on a survey of 3,300 firms in 25transition countries to shed light on the factors that influencerestructuring by firms and their subsequent performance. These datahave three main advantages over those used in previous work. First,they measure directly the degree of competition perceived by each firmin its principal market rather than attempting to infer this from marketdata as measured by statistical agencies. Second, the fact that transitioncountries have market structures inherited from the past avoids some ofthe endogeneity problems associated with measures of competition inmarket economies. Third, the breadth of cross-country variationprovides a method of dealing with the fact that firm-level measures ofthe external environment will not be independent of the firm?s ownperformance. We find evidence of a robust inverted-U effect ofcompetition on performance that is both statistically and economicallysignificant. This paper examines the importance of competition in the growth anddevelopment of firms. We draw on a survey of 3,300 firms in 25transition countries to shed light on the factors that influencerestructuring by firms and their subsequent performance. These datahave three main advantages over those used in previous work. First,they measure directly the degree of competition perceived by each firmin its principal market rather than attempting to infer this from marketdata as measured by statistical agencies. Second, the fact that transitioncountries have market structures inherited from the past avoids some ofthe endogeneity problems associated with measures of competition inmarket economies. Third, the breadth of cross-country variationprovides a method of dealing with the fact that firm-level measures ofthe external environment will not be independent of the firm?s ownperformance. We find evidence of a robust inverted-U effect ofcompetition on performance that is both statistically and economicallysignificant

    Variable-speed Generators with Flux Weakening

    Get PDF
    A cost-competitive, permanent-magnet 20 kW generator is designed such that the following criteria are satisfied: an (over) load capability of at least 30 kW over the entire speed range of 60-120 rpm, generator weight of about 550 lbs with a maximum radial stator flux density of 0.82 T at low speed, unity power factor operation, acceptably small synchronous reactances and operation without a gear box. To justify this final design four different generator designs are investigated: the first two designs are studied to obtain a speed range from 20 to 200 rpm employing rotor field weakening, and the latter two are investigated to obtain a maximum speed range of 40 to 160 rpm based on field weakening via the stator excitation. The generator reactances and induced voltages are computed using finite element/difference solutions. Generator losses and efficiencies are presented for all four designs at rated temperature of Tr=120C

    Fixing the Reference Frame for PPMXL Proper Motions Using Extragalactic Sources

    Get PDF
    We quantify and correct systematic errors in PPMXL proper motions using extragalactic sources from the first two LAMOST data releases and the Veron-Cetty & Veron Catalog of Quasars. Although the majority of the sources are from the Veron catalog, LAMOST makes important contributions in regions that are not well-sampled by previous catalogs, particularly at low Galactic latitudes and in the south Galactic cap. We show that quasars in PPMXL have measureable and significant proper motions, which reflect the systematic zero-point offsets present in the catalog. We confirm the global proper motion shifts seen by Wu, Ma, & Zhou (2011), and additionally find smaller-scale fluctuations of the QSO-derived corrections to an absolute frame. We average the proper motions of 158,106 extragalactic objects in bins of 3x3 degrees and present a table of proper motion corrections.Comment: Accepted for publication in RAA; 12 pages, 6 figures (Fig. 1 at reduced resolution); full table of corrections available in online journal, with arxiv ancillary files (as ASCII table), or by reques

    Intrinsic degradation mechanism of nearly lattice-matched InAlN layers grown on GaN substrates

    Full text link
    Thanks to its high refractive index contrast, band gap and polarization mismatch compared to GaN, In0.17Al0.83N layers lattice-matched to GaN are an attractive solution for applications such as distributed Bragg reflectors, ultraviolet light-emitting diodes, or high electron mobility transistors. In order to study the structural degradation mechanism of InAlN layers with increasing thickness, we performed metalorganic vapor phase epitaxy of InAlN layers of thicknesses ranging from 2 to 500 nm, on free-standing (0001) GaN substrates with a low density of threading dislocations, for In compositions of 13.5% (layers under tensile strain), and 19.7% (layers under compressive strain). In both cases, a surface morphology with hillocks is initially observed, followed by the appearance of V-defects. We propose that those hillocks arise due to kinetic roughening, and that V-defects subsequently appear beyond a critical hillock size. It is seen that the critical thickness for the appearance of V-defects increases together with the surface diffusion length either by increasing the temperature or the In flux because of a surfactant effect. In thick InAlN layers, a better (worse) In incorporation occurring on the concave (convex) shape surfaces of the V-defects is observed leading to a top phase-separated InAlN layer lying on the initial homogeneous InAlN layer after V-defects coalescence. It is suggested that similar mechanisms could be responsible for the degradation of thick InGaN layers

    Boundary detection in disease mapping studies

    Full text link
    In disease mapping, the aim is to estimate the spatial pattern in disease risk over an extended geographical region, so that areas with elevated risks can be identified. A Bayesian hierarchical approach is typically used to produce such maps, which models the risk surface with a set of spatially smooth random effects. However, in complex urban settings there are likely to be boundaries in the risk surface, which separate populations that are geographically adjacent but have very different risk profiles. Therefore this paper proposes an approach for detecting such risk boundaries, and tests its effectiveness by simulation. Finally, the model is applied to lung cancer incidence data in Greater Glasgow, Scotland, between 2001 and 2005
    • 

    corecore