389 research outputs found
Characteristics of pelleted wheat middlings that affect summer storage
Pelleted wheat middlings samples were collected from four Kansas flour mills in March, April, and May, 1997 to characterize their moisture content and bulk density as they would be purchased directly from the mills by a livestock producer. The average moisture content of pelleted wheat middlings was 14% as they left the mills but declined during the spring to 13.6%. Pellets purchased from Kansas mills during the summer months are likely to contain 13.0 to 13.5% moisture. The average bulk density was approximately 40 lb/ft3 , which is equivalent
to about 50 lb/bu. Based on the equilibrium moisture contents determined from the collected
samples, if air at typical Kansas summertime temperatures is above 65% relative humidity, pellets will absorb moisture during storage
Earth's Dynamic Past Revealed by Detrital Thermochronometry
A dvances in detrital noble gas thermochronometry by Ar-40/Ar-39 and (U-Th)/He dating are improving the resolution of sedimentary provenance reconstructions and are providing new insights into the evolution of Earth's surface. Detrital thermochronometry has the ability to quantify tectonic unroofing or erosion, temporal and dynamic connections between sediment source and sink, sediment lag-times and transfer rates, the timing of deposition, and postdepositional burial heating. Hence, this technique has the unique ability to use the detrital record in sedimentary basins to reconstruct Earth's dynamic long-term landscape evolution and how basins are coupled to their hinterlands
Carbon Film in Radio Frequency Surface Plasma Source with Cesiation
It is assumed that persistent cesiation in the SNS RF SPS is related to
deposition of carbon film on the collar converter. The work function dependence
for graphite with alkali deposition has no minimum typical for metals and
semiconductors and the final work function is higher. For this reason, the
probability of H- secondary emission from cesiated metal and semiconductors can
be higher than from cesiated carbon films but the carbon film maintains
cesiation longer and can operate with low cesium consumption
Accommodation of transpressional strain in the Arabia-Eurasia collision zone: new constraints from (U-Th)/He thermochronology in the Alborz mountains, north Iran
The Alborz range of N Iran provides key information on the spatiotemporal evolution and characteristics of the Arabia-Eurasia continental collision zone. The southwestern Alborz range constitutes a transpressional duplex, which accommodates oblique shortening between Central Iran and the South Caspian Basin. The duplex comprises NW-striking frontal ramps that are kinematically linked to inherited E-W-striking, right-stepping lateral to obliquely oriented ramps. New zircon and apatite (U-Th)/He data provide a high-resolution framework to unravel the evolution of collisional tectonics in this region. Our data record two pulses of fast cooling associated with SW-directed thrusting across the frontal ramps at ~ 18–14 and 9.5-7.5 Ma, resulting in the tectonic repetition of a fossil zircon partial retention zone and a cooling pattern with a half U-shaped geometry. Uniform cooling ages of ~ 7–6 Ma along the southernmost E-W striking oblique ramp and across its associated NW-striking frontal ramps suggests that the ramp was reactivated as a master throughgoing, N-dipping thrust. We interpret this major change in fault kinematics and deformation style to be related to a change in the shortening direction from NE to N/NNE. The reduction in the obliquity of thrusting may indicate the termination of strike-slip faulting (and possibly thrusting) across the Iranian Plateau, which could have been triggered by an increase in elevation. Furthermore, we suggest that ~ 7-6-m.y.-old S-directed thrusting predated inception of the westward motion of the South Caspian Basin
Middle to Late Miocene Extremely Rapid Exhumation and Thermal Reequilibration in the Kung Co Rift, Southern Tibet
The Kung Co rift is an approximately NNW striking, WSW dipping normal fault exposed in southern Tibet and is part of an extensive network of active approximately NS striking normal faults exposed across the Tibetan Plateau. Detailed new and published (U-Th)/He zircon and apatite thermochronometric data from the footwall of the early Miocene Kung Co granite provide constraints on the middle Miocene to present-day exhumation history of the footwall to the Kung Co fault. Inverse modeling of thermochronometric data yield age patterns that are interpreted as indicating (1) initiation of normal fault slip at ∼12–13 Ma and rapid exhumation of the footwall between ∼13 and 10 Ma, (2) acceleration of normal fault slip at rates of 21.9–6.9 mm/yr at ∼10 Ma, (3) rapid thermal reequilibration between 10 and 9 Ma, and (4) slow exhumation and/or quiescence from ∼9 Ma to the present day. Hanging glacial valleys in the footwall and fault scarps that cut late Quaternary till and moraine deposits indicate that fault slip continues today. Middle to late Miocene initiation of extension across the Kung Co rift is broadly the same as the documented initiation of EW extension across the south central Tibetan Plateau. Eastward flow of middle or lower crust from beneath Tibet accommodated by northward underthrusting of Indian crust beneath Tibet provides a plausible explanation for the onset of EW extension across the Tibetan Plateau
Constraining Deformation in the North Pamir and the Westernmost Tarim Basin
Abstract HKT-ISTP 2013
A
NNLO QCD predictions for the H -> WW -> l l nu nu signal at the LHC
We present a first computation of the NNLO QCD cross section at the LHC for
the production of four leptons from a Higgs boson decaying into W bosons. We
study the cross section for a Higgs boson mass Mh = 165 GeV; around this value
a Standard Model Higgs boson decays almost exclusively into W-pairs. We apply
all nominal experimental cuts on the final state leptons and the associated jet
activity and study the magnitude of higher-order effects up to NNLO on all
kinematic variables which are constrained by experimental cuts. We find that
the magnitude of the higher-order corrections varies significantly with the
signal selection cuts. As a main result we give the value of the cross section
at NNLO with all selection cuts envisaged for the search for the Higgs boson.Comment: typos corrected, version accepted in JHE
Velocity Dependence Of One- And Two-electron Processes In Intermediate-velocity Ar16++He Collisions
We report investigations of one- and two-electron processes in the collisions of 0.9-keV/u to 60-keV/u (vp=0.19-1.55 a.u.) Ar16+ ions with He targets. The cross sections for these processes were measured by observing the final charges of the Ar ions and the recoiling target ions in coincidence. The average Q values for the capture channels were determined by measuring the longitudinal momenta of the recoiling target ions. Single capture (SC) is the dominant process and is relatively independent of the projectile energy. The two-electron transfer-ionization (TI) process is the next largest and slowly increases with projectile energy. The Q values for both SC and TI decrease with increasing projectile energy. Our data thereby suggest that electrons are captured into less tightly bound states as the collision velocity is increased. Both double capture and single ionization are much smaller and fairly independent of the projectile energy. The energy independence of SI is somewhat surprising as our energy range spans the region of the target electron velocity where ionization would be expected to increase. Our analysis suggests that the ionization process is being suppressed by SC and TI processes. © 1993 The American Physical Society
Use of FLUXNET in the Community Land Model development
The Community Land Model version 3 (CLM3.0) simulates land-atmosphere exchanges in response to climatic forcings. CLM3.0 has known biases in the surface energy partitioning as a result of deficiencies in its hydrological and biophysical parameterizations. Such models, however, need to be robust for multidecadal global climate simulations. FLUXNET now provides an extensive data source of carbon, water and energy exchanges for investigating land processes, and it encompasses a global range of ecosystem-climate interactions. Data from 15 FLUXNET sites are used to identify and improve model deficiencies. Including a prognostic aquifer, a bare soil evaporation resistance formulation and numerous other changes in the model result in a significantly improved soil hydrology and energy partitioning. Terrestrial water storage increased by up to 300 mm in warm climates and decreased in cold climates. Nitrogen control of photosynthesis is revealed as another missing process in the model. These improvements increase the correlation coefficient of hourly and monthly latent heat fluxes from a range of 0.5–0.6 to the range of 0.7–0.9. RMSE of the simulated sensible heat fluxes decrease by 20–50%. Primary production is overestimated during the wet season in mediterranean and tropical ecosystems. This might be related to missing carbon-nitrogen dynamics as well as to site-specific parameters. The new model (CLM3.5) with an improved terrestrial water cycle should lead to more realistic land-atmosphere exchanges in coupled simulations. FLUXNET is found to be a valuable tool to develop and validate land surface models prior to their application in computationally expensive global simulations
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