51 Search Results
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Evaluation of 235U Isotopic Dilution with the Addition of Depleted Uranium to Supernatant Liquid Waste
Laboratory-scale results on experiments performed to examine the feasibility of isotopic dilution of 235U in supernatant liquid storage tanks at the Savannah River Site are described. Here, the isotopic dilution tests were accomplished by adding an alkaline depleted uranium solution to small portions of simulated and actual storage tank waste solutions with enriched 235U compositions. Based on the laboratory observations, recommendations were made, which involved the addition of significant quantities of uranyl carbonate solution to more than 4 million l of 235U enriched waste stored in tank 43H at the site to reduce the risk for criticality. -
Simulated impact of the renewable fuels standard on US Conservation Reserve Program enrollment and conversion
Abstract A socioeconomic model is used to estimate the land‐use implications on the U.S. Conservation Reserve Program from potential increases in second‐generation biofuel production. A baseline scenario with no second‐generation biofuel production is compared to a scenario where the Renewable Fuels Standard ( RFS 2) volumes are met by 2022. We allow for the possibility of converting expiring CRP lands to alternative uses such as conventional crops, dedicated second‐generation biofuel crops, or harvesting existing CRP grasses for biomass. Results indicate that RFS 2 volumes ( RFS 2‐v) can be met primarily with crop residues (78% of feedstock demand) and woodymore » -
Revised formulation of the macroscopic maxwell theory
A modified version of the macroscopic Maxwell theory is developed with the purpose of removing some of the current contradictions and inconsistencies. One of the crucial problems of the current electromagnetic theory concerns the concept of energy. It appears that energy which has a clearly defined physical significance in all fields of physics has not been properly incorporated into the Maxwell-Lorentz theory. Therefore, the electromagnetic energy in a dissipative system as interpreted in the current version of the theory is not « energy » in the same sense as one usually interprets this concept in classical mechanics. The main objectmore » -
Revised formulation of the macroscopic maxwell theory
The theory of energy propagation in dispersive media formulated by Brillouin is generalized and extended by taking into account energy attenuation or energy growth during the transmission process. Because of the exponential decay due to attenuation, the concept of propagation velocity of an electromagnetic disturbance can now be shown to have a physical meaning even if there is absorption, and in such a case the velocity of the disturbance is represented by the velocity of the point at which it attains its maximum intensity. Further, expressions are obtained for the energy density and the energy flow in an absorbing medium,more » -
Has the Sun Set on Quantum Dot-Sensitized Solar Cells?
This is a reminder, a review and a look toward the future prospects for quantum dot-sensitized solar cells - a reminder of the highly viable, energy-efficient solar cells achievable. This is also a review of ground-breaking devices and their similarities to the near unity photon-to-electron mechanisms of photosynthesis; a look toward architectures that capitalize on the advances observed in previous work. -
Hard Photodisintegration of a Proton Pair
We present the first study of high energy photodisintegration of proton-pairs through the gamma + 3He -> p+p+n channel. Photon energies from 0.8 to 4.7 GeV were used in kinematics corresponding to a proton pair with high relative momentum and a neutron nearly at rest. An s^{-11} scaling of the cross section was observed, as predicted by the constituent counting rule. The onset of the scaling is at a higher energy and the cross section is significantly lower then for pn pair photodisintegration. For photon energies below the scaling region, the scaled cross section was found to present a strongmore » -
Differential cross sections for the reactions and
In high-statistics differential cross sections for the reactions γ p -> p η and γ p -> p η' the CLAS at Jefferson Lab was used to measure the center-of-mass energies from near threshold up to 2.84 GeV. The eta-prime results are the most precise to date and provide the largest energy and angular coverage. The eta measurements extend the energy range of the world's large-angle results by approximately 300 MeV. These new data, in particular the η' measurements, are likely to help constrain the analyses being performed to search for new baryon resonance states. -
Revised formulation of the kinetic plasma theory
Using the Maxwellian macroscopic approach and analysing the formulation of the dielectric constant, it is shown that the concept of energy has not been properly incorporated into the current kinetic plasma theory. The difficulties are due to the Boltzmann collisional term (∂F/∂t)coll which accounts for a change in the velocity distribution due to collisions alone. If one attempts to rephrase the Boltzmann-Vlasov theory in terms of the Maxwellian macroscopic formulation, one obtains an expression for energy which is not consistent with the meaning of this concept in generalized dynamics. In a revised version developed in this analysis the Boltzmann collisionalmore » -
Neutron-deficient Mercury Isotopes1
In this work, high energy bombardments with protons on gold and α-particles on platinum were performed to study neutron-deficient mercury isotopes. Two new mercury isotopes have been definitely identified: Hg192, T1/2 = 5.7 ± 0.5 hours, 1.18 mev. ß+, 0.18 mev. conversion electrons, K, L X-rays and 1.39 mev. γ-ray; parent of 4.0 hour Au192. Hg193, T1/2 = 10.0 ± 0.5 hours Noß+, K, L X-rays, 0.18 mev. conversion electrons; parent of 15.3 hour Au193. Tentatively identified was Hg195 of 31 hour half-life, although this value may be in error owing to masking by the isomeric pair at Hg197. Decaymore »