82,140 research outputs found
A Letter to John W. Carlin
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
Impedance of biconical and cylindrical dipoles in warm isotropic plasm
Thallium and its contents in Remata carbonate rocks
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
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
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
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
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
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
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