67,121 research outputs found
Wet atmospheric generation apparatus
The invention described relates to an apparatus for providing a selectively humidified gas to a camera canister containing cameras and film used in space. A source of pressurized gas (leak test gas or motive gas) is selected by a valve, regulated to a desired pressure by a regulator, and routed through an ejector (venturi device). A regulated source of water vapor in the form of steam from a heated reservoir is coupled to a low pressure region of the ejector which mixes with high velocity gas flow through the ejector. This mixture is sampled by a dew point sensor to obtain dew point thereof (ratio of water vapor to gas) and the apparatus adjusted by varying gas pressure or water vapor to provide a mixture at a connector having selected humidity content
Interoperability between Multimedia Collections for Content and Metadata-Based Searching
Artiste is a European project developing a cross-collection search system for art galleries and museums. It combines image content retrieval with text based retrieval and uses RDF mappings in order to integrate diverse databases. The test sites of the Louvre, Victoria and Albert Museum, Uffizi Gallery and National Gallery London provide their own database schema for existing metadata, avoiding the need for migration to a common schema. The system will accept a query based on one museum’s fields and convert them, through an RDF mapping into a form suitable for querying the other collections. The nature of some of the image processing algorithms means that the system can be slow for some computations, so the system is session-based to allow the user to return to the results later. The system has been built within a J2EE/EJB framework, using the Jboss Enterprise Application Server
NONPARAMETRIC ESTIMATION OF MULTIPRODUCT AND PRODUCT-SPECIFIC ECONOMIES OF SCALE
Numerous studies have utilized nonparametric estimation of production efficiency but no such study focuses on multiproduct or product-specific economies of scale. A mathematical program is specified to nonparametrically estimate these measures for crops and livestock for Kansas farms. Results show that many farms would realize benefits from expansion.Industrial Organization,
Hole polaron formation and migration in olivine phosphate materials
By combining first principles calculations and experimental XPS measurements,
we investigate the electronic structure of potential Li-ion battery cathode
materials LiMPO4 (M=Mn,Fe,Co,Ni) to uncover the underlying mechanisms that
determine small hole polaron formation and migration. We show that small hole
polaron formation depends on features in the electronic structure near the
valence-band maximum and that, calculationally, these features depend on the
methodology chosen for dealing with the correlated nature of the
transition-metal d-derived states in these systems. Comparison with experiment
reveals that a hybrid functional approach is superior to GGA+U in correctly
reproducing the XPS spectra. Using this approach we find that LiNiPO4 cannot
support small hole polarons, but that the other three compounds can. The
migration barrier is determined mainly by the strong or weak bonding nature of
the states at the top of the valence band, resulting in a substantially higher
barrier for LiMnPO4 than for LiCoPO4 or LiFePO4
Critical evaluation of the computational methods used in the forced polymer translocation
In forced polymer translocation, the average translocation time, ,
scales with respect to pore force, , and polymer length, , as . We demonstrate that an artifact in Metropolis Monte Carlo
method resulting in breakage of the force scaling with large may be
responsible for some of the controversies between different computationally
obtained results and also between computational and experimental results. Using
Langevin dynamics simulations we show that the scaling exponent is not universal, but depends on . Moreover, we show that forced
translocation can be described by a relatively simple force balance argument
and to arise solely from the initial polymer configuration
MODELING CHANGES IN THE U.S. DEMAND FOR CROP INSURANCE DURING THE 1990S
The crop insurance purchase decision for a group of Kansas farmers is analyzed using data from 1990sa period that experienced many changes in the federal crop insurance program. Farm-level data are used. Results indicate a reduction in the elasticity of the demand for crop insurance with respect to premium rates by the end of the decade. This corresponded with a considerable increase in government subsidies by the end of the 1990s. This may also reflect the attractiveness of new revenue insurance products that may have made producers less sensitive to premium changes.Risk and Uncertainty,
Interfacial friction between semiflexible polymers and crystalline surfaces
The results obtained from molecular dynamics simulations of the friction at
an interface between polymer melts and weakly attractive crystalline surfaces
are reported. We consider a coarse-grained bead-spring model of linear chains
with adjustable intrinsic stiffness. The structure and relaxation dynamics of
polymer chains near interfaces are quantified by the radius of gyration and
decay of the time autocorrelation function of the first normal mode. We found
that the friction coefficient at small slip velocities exhibits a distinct
maximum which appears due to shear-induced alignment of semiflexible chain
segments in contact with solid walls. At large slip velocities the decay of the
friction coefficient is independent of the chain stiffness. The data for the
friction coefficient and shear viscosity are used to elucidate main trends in
the nonlinear shear rate dependence of the slip length. The influence of chain
stiffness on the relationship between the friction coefficient and the
structure factor in the first fluid layer is discussed.Comment: 31 pages, 12 figure
Did U.S. Bank Supervisors Get Tougher During the Credit Crunch? Did They Get Easier During the Banking Boom? Did It Matter to Bank Lending?
We test three hypotheses regarding changes in supervisory toughness' and their effects on bank lending. The data provide modest support for all three hypotheses that there was an increase in toughness during the credit crunch period (1989-1992), that there was a decline in toughness during the boom period (1993-1998), and that changes in toughness, if they occurred, affected bank lending. However, all of the measured effects are small, with 1% or less of loans receiving harsher or easier classification, about 3% of banks receiving better or worse CAMEL ratings, and bank lending being changed by 1% or less of assets.
Farmers' Crop Acreage Decisions in the Presence of Credit Constraints: Do Decoupled Payments Matter?
While in theory decoupled payments do not distort production decisions, in practice there are several potential coupling mechanisms for these payments. We use farm-level data from Kansas to revisit the issue of how (de)coupled are these supposedly “decoupled” payments by focusing on how they may impact production through credit constraints. In particular, we study how production effects may have differed across farmers with varying levels of debt pressure. Our empirical approach exploits the fact that we can observe the same farm over time (and so can account for the effects of time-constant omitted variables) to study how these payments affected total crop acres, owned acres, and the decisions to plant corn, sorghum, soybeans and wheat. Like previous studies, we find small production effects. Nonetheless our results suggest decoupled payments have potentially distortionary effects on production.decoupled payments, credit constraints, Agricultural Finance, Q17, Q18,
The Transformation of the U.S. Banking Industry: What a Long, Strange Trips It's Been
macroeconomics, Transformation, U.S. Banking Industry
- …