11,223 research outputs found
A computer program for calculating design and off-design performance for turbojet and turbofan engines
Program uses component performance maps to enable user to do analytical engine cycle calculations. Through scaling procedure, each of the component maps can be used to represent a family of maps. Either convergent or convergent-divergent nozzles may be used
A computer program for calculating design and off-design performance of two- and three-spool turbofans with as many as three nozzles
Program uses component performance maps to enable user to do analytical engine cycle calculations. Either convergent or convergent-divergent nozzles may be used
Restorative Justice to Supplement Deterrence-Based Punishment: An Empirical Study and Theoretical Reconceptualization of the EPA\u27s Power Plant Enforcement Initiative, 2000-2011
From the late 1970s to the end of the 1990s, electricity producers modified and operated coal-fired power plants in violation of the Environment Protection Agencyâs (EPA) permitting requirements, creating widespread air quality degradation. The EPAâs policy of lax oversight ended in 1999 when it launched a large, coordinated enforcement effort. The 2012 Republican presidential candidates all denounced this more vigilant EPA as engaging in economic terrorism through âsue and settleâ tactics that amount to backdoor regulation. This article evaluates federal environmental enforcement, drawing upon objective data from our empirical study of EPA permitting violation settlements for coal-fired power plants entered into between January 1, 2000, and December 31, 2011. The data reveals that the EPAâs enforcement policy reflects a unique jurisprudence that creatively combines both deterrence-based punishment through appropriately levied civil penalties and restorative justice principles in the form of mitigation projects and mandatory injunctions. Other regulatory agencies should consider adopting restorative justice insights in designing remedies for diffuse civil wrongs such as securities fraud, consumer product safety, and unfair or deceptive trade practices
A sister of PIN1 gene in tomato (Solanum lycopersicum) defines leaf and flower organ initiation patterns by maintaining epidermal auxin flux
AbstractThe spatiotemporal localization of the plant hormone auxin acts as a positional cue during early leaf and flower organogenesis. One of the main contributors to auxin localization is the auxin efflux carrier PIN-FORMED1 (PIN1). Phylogenetic analysis has revealed that PIN1 genes are split into two sister clades; PIN1 and the relatively uncharacterized Sister-Of-PIN1 (SoPIN1). In this paper we identify entire-2 as a loss-of-function SlSoPIN1a (Solyc10g078370) mutant in Solanum lycopersicum. The entire-2 plants are unable to specify proper leaf initiation leading to a frequent switch from the wild type spiral phyllotactic pattern to distichous and decussate patterns. Leaves in entire-2 are large and less complex and the leaflets display spatial deformities in lamina expansion, vascular development, and margin specification. During sympodial growth in entire-2 the specification of organ position and identity is greatly affected resulting in variable branching patterns on the main sympodial and inflorescence axes. To understand how SlSoPIN1a functions in establishing proper auxin maxima we used the auxin signaling reporter DR5: Venus to visualize differences in auxin localization between entire-2 and wild type. DR5: Venus visualization shows a widening of auxin localization which spreads to subepidermal tissue layers during early leaf and flower organogenesis, showing that SoPIN1 functions to focus auxin signaling to the epidermal layer. The striking spatial deformities observed in entire-2 help provide a mechanistic framework for explaining the function of the SoPIN1 clade in S.lycopersicum
Cascade of magnetic field induced Lifshitz transitions in the ferromagnetic Kondo lattice material YbNi4P2
A ferromagnetic quantum critical point is thought not to exist in two and
three-dimensional metallic systems yet is realized in the Kondo lattice
compound YbNi4(P,As)2, possibly due to its one-dimensionality. It is crucial to
investigate the dimensionality of the Fermi surface of YbNi4P2 experimentally
but common probes such as ARPES and quantum oscillation measurements are
lacking. Here, we studied the magnetic field dependence of transport and
thermodynamic properties of YbNi4P2. The Kondo effect is continuously
suppressed and additionally we identify nine Lifshitz transitions between 0.4
and 18 T. We analyze the transport coefficients in detail and identify the type
of Lifshitz transitions as neck or void type to gain information on the Fermi
surface of YbNi4P2. The large number of Lifshitz transitions observed within
this small energy window is unprecedented and results from the particular flat
renormalized band structure with strong 4f-electron character shaped by the
Kondo lattice effect.Comment: 6 pages, 4 figure
Dissolved organic carbon uptake in streams: A review and assessment of reachâscale measurements
Quantifying the role that freshwater ecosystems play in the global carbon cycle requires accurate measurement and scaling of dissolved organic carbon (DOC) removal in river networks. We reviewed reachâscale measurements of DOC uptake from experimental additions of simple organic compounds or leachates to inform development of aquatic DOC models that operate at the river network, regional, or continental scale. Median DOC uptake velocity (vf) across all measurements was 2.28âmmâminâ1. Measurements using simple compound additions resulted in faster vf (2.94âmmâminâ1) than additions of leachates (1.11âmmâminâ1). We also reviewed published data of DOC bioavailability for ambient stream water and leaf leachate DOC from laboratory experiments. We used these data to calculate and apply a correction factor to leaf leachate uptake velocity to estimate ambient stream water DOC uptake rates at the reach scale. Using this approach, we estimated a median ambient stream DOC vf of 0.26âmmâminâ1. Applying these DOC vf values (0.26, 1.11, 2.28, and 2.94âmmâminâ1) in a river network inverse model in seven watersheds revealed that our estimated ambient DOC vf value is plausible at the network scale and 27 to 45% of DOC input was removed. Applying the median measured simple compound or leachate vf in whole river networks would require unjustifiably high terrestrial DOC inputs to match observed DOC concentrations at the basin mouth. To improve the understanding and importance of DOC uptake in fluvial systems, we recommend using a multiscale approach coupling laboratory assays, with reachâscale measurements, and modeling
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Automated Measurement of Spatially Resolved Hair-Hair Single Fiber Adhesion.
The adhesion force between individual human hair fibers in a crosshair geometry was measured by observing their natural bending and adhesive jumps out of contact, using optical video microscopy. The hair fibers' natural elastic responses, calibrated by measuring their natural resonant frequencies, were used to measure the forces. Using a custom-designed, automated apparatus to measure thousands of individual hair-hair contacts along millimeter length scales of hair, it was found that a broad, yet characteristic, spatially variant distribution in adhesion force is measured on the 1 to 1000 nN scale for both clean and conditioner-treated hair fibers. Comparison between the measured adhesion forces and adhesion forces modeled from the hairs' surface topography (measured using confocal laser profilometry) shows they have a good order-of-magnitude agreement and have similar breadth and shape. The agreement between the measurements and the model suggests, perhaps unsurprisingly, that hair-hair adhesion is governed, to a first approximation, by the unique surface structure of the hairs' cuticles and, therefore, the large distribution in local mean curvature at the various individual contact points along the hairs' lengths. We posit that haircare products could best control the surface properties (or at least the adhesive properties) between hairs by directly modifying the hair surface microstructure
Coulomb Blockade in a Coupled Nanomechanical Electron Shuttle
We demonstrate single electron shuttling through two coupled nanomechanical
pendula. The pendula are realized as nanopillars etched out of the
semiconductor substrate. Coulomb blockade is found at room temperature,
allowing metrological applications. By controlling the mechanical shuttling
frequency we are able to validate the different regimes of electron shuttling
Toward a One Percent Measurement of Frame Dragging by Spin with Satellite Laser Ranging to LAGEOS, LAGEOS 2 and LARES and GRACE gravity models
none8During the past century Einsteinâs theory of General Relativity gave rise to an experimental triumph; however, there are still aspects of this theory to be measured or more accurately tested. Today one of the main challenges in experimental gravitation, together with the direct detection of gravitational waves, is the accurate measurement of the gravitomagnetic field generated by the angular momentum of a body. Here, after a brief introduction on frame-dragging, gravitomagnetism and Lunar Laser Ranging tests, we describe the past measurements of frame-dragging by the Earth spin using the satellites LAGEOS, LAGEOS 2 and the Earthâs gravity models obtained by the GRACE project. We demonstrate that these measurements have an accuracy of approximately 10%.
We then describe the LARES experiment to be launched in 2010 by the Italian Space Agency for a measurement of frame-dragging with an accuracy of a few percent.
We finally demonstrate that a number of claims by a single individual, that the error budget of the frame-dragging measurements with LAGEOS-LAGEOS 2 and LARES has been underestimated, are indeed ill-founded.IGNAZIO CIUFOLINI; Antonio Paolozzi; Erricos C. Pavlis; John C. Ries; Rolf Koenig; Richard A. Matzner; Giampiero Sindoni and Hans NeumayerCiufolini, Ignazio; Antonio, Paolozzi; Erricos C., Pavlis; John C., Ries; Rolf, Koenig; Richard A., Matzner; Giampiero, Sindoni; Hans, Neumaye
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