Development and testing of spheroidal inorganic sorbents

Objective was to develop sodium titanate (ST) microspheres, made by the HMTA (hexamethylenetetramine) internal gelation process, to remove radionuclides and heavy metals from waste streams at DOE sites. to determine the optimum amount of ST that can be embedded in hydrous Ti oxide (HTO) microspheres, batches of 9.2 to 23.3% ST in HTO were prepared. Crush strength of the air-dried microspheres was found to be highest. Sr was removed from simulated supernatant by all composite microspheres; 13.2% ST/HTO worked best

Agronomic and silage quality traits of forage sorghum cultivars in 1995

Agronomic and silage quality traits were measure d for 37 forage sorghum cultivars and three grain sorghum hybrids. The 1995 growing season was characterized by above average rainfall in the spring and early summer, and a hard freeze on September 22. At the time of the freeze, 20 cultivars had reached the early-milk to early-dough stage, 12 were in the bloom stage, and the remaining eight were still in the early- to late-boot stage . The late planting date and low plant populations resulted in below-normal whole-plant D M and grain yields. Plant height s for the grain sorghums were near normal, but the forage sorghums were well below expected plant heights. The preensiled, whole-plan t DM contents of the 37 forage sorghums ranged from 23.0 to 39.9%. As expected , the silage nutritive value traits of CP, NDF, and ADF were most favorable for the three grain sorghum hybrids and least favorable for the eight forage sorghum hybrids that were still in the boot stage when the freeze occurred

Defect and anisotropic gap induced quasi-one-dimensional modulation of local density of states in YBa2_2Cu3_3O7−δ_{7-\delta}

Motivated by recent angle-resolved photoemission spectroscopy (ARPES) measurement that superconducting YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) exhibits a $d_{x^2-y^2} + s$-symmetry gap, we show possible quasi-one-dimensional modulations of local density of states in YBCO. These aniostropic gap and defect induced stripe structures are most conspicuous at higher biases and arise due to the nesting effect associated with a Fermi liquid. Observation of these spectra by scanning tunneling microscopy (STM) would unify the picture among STM, ARPES, and inelastic neutron scattering for YBCO.Comment: 4 pages, 4 figure

Generating vortex rings in Bose-Einstein condensates in the line-source approximation

We present a numerical method for generating vortex rings in Bose-Einstein condensates confined in axially symmetric traps. The vortex ring is generated using the line-source approximation for the vorticity, i.e., the rotational of the superfluid velocity field is different from zero only on a circumference of given radius located on a plane perpendicular to the symmetry axis and coaxial with it. The particle density is obtained by solving a modified Gross-Pitaevskii equation that incorporates the effect of the velocity field. We discuss the appearance of density profiles, the vortex core structure and the vortex nucleation energy, i.e., the energy difference between vortical and ground-state configurations. This is used to present a qualitative description of the vortex dynamics.Comment: Accepted for publication in Phys. Rev.

Vacuum polarization of a scalar field in wormhole spacetimes

An analitical approximation of $$ for a scalar field in a static spherically symmetric wormhole spacetime is obtained. The scalar field is assumed to be both massive and massless, with an arbitrary coupling $\xi$ to the scalar curvature, and in a zero temperature vacuum state.Comment: 10 pages, RevTeX, two eps figure

Removal of steroid estrogens in carbonaceous and nitrifying activated sludge processes

This is the post-print version of the final paper published in Chemosphere. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2010 Elsevier B.V.A carbonaceous (heterotrophic) activated sludge process (ASP), nitrifying ASP and a nitrifying/denitrifying ASP have been studied to examine the role of process type in steroid estrogen removal. Biodegradation efficiencies for total steroid estrogens (ΣEST) of 80 and 91% were recorded for the nitrifying/denitrifying ASP and nitrifying ASP respectively. Total estrogen biodegradation (ΣEST) was only 51% at the carbonaceous ASP, however, the extent of biodegradation in the absence of nitrification clearly indicates the important role of heterotrophs in steroid estrogen removal. The low removal efficiency did not correlate with biomass activity for which the ASPcarbonaceous recorded 80 μg kg−1 biomass d−1 compared to 61 and 15 μg kg−1 biomass d−1 at the ASPnitrifying and ASPnitrifying/denitrifying respectively. This finding was explained by a moderate correlation (r2 = 0.55) between total estrogen loading (ΣEST mg m−3 d−1) and biomass activity (μg ΣEST degraded kg−1 d−1) and has established the impact of loading on steroid estrogen removal at full-scale. At higher solids retention time (SRT), steroid estrogen biodegradation of >80% was observed, as has previously been reported. It is postulated that hydraulic retention time (HRT) is as important as SRT as this governs both reaction time and loading. This observation is based on the high specific estrogen activity determined at the ASPcarbonaceous plant, the significance of estrogen loading and the positive linear correlation between SRT and HRT.Public Utilities Board of Singapore, Anglian Water Ltd., Severn Trent Water Ltd., Thames Water Utilities Ltd., United Utilities Plc., and Yorkshire Water Services Ltd

Energy band structure and intrinsic coherent properties in two weakly linked Bose Einstein Condensates

The energy band structure and energy splitting due to quantum tunneling in two weakly linked Bose-Einstein condensates were calculated by using the instanton method. The intrinsic coherent properties of Bose Josephson junction were investigated in terms of energy splitting. For $E_{C}/E_{J}\ll 1$, the energy splitting is small and the system is globally phase coherent. In the opposite limit, $E_{C}/E_{J}\gg 1$, the energy splitting is large and the system becomes a phase dissipation. Our reslults suggest that one should investigate the coherence phenomna of BJJ in proper condition such as $E_{C}/E_{J}\sim 1$.Comment: to appear in Phys. Rev. A, 2 figure

Atom focusing by far-detuned and resonant standing wave fields: Thin lens regime

The focusing of atoms interacting with both far-detuned and resonant standing wave fields in the thin lens regime is considered. The thin lens approximation is discussed quantitatively from a quantum perspective. Exact quantum expressions for the Fourier components of the density (that include all spherical aberration) are used to study the focusing numerically. The following lens parameters and density profiles are calculated as functions of the pulsed field area $\theta$: the position of the focal plane, peak atomic density, atomic density pattern at the focus, focal spot size, depth of focus, and background density. The lens parameters are compared to asymptotic, analytical results derived from a scalar diffraction theory for which spherical aberration is small but non-negligible ($\theta \gg 1$). Within the diffraction theory analytical expressions show that the focused atoms in the far detuned case have an approximately constant background density $0.5(1-0.635\theta ^{- 1/2})$ while the peak density behaves as $$, the focal distance or time as $\theta ^{-1}(1+1.27\theta ^{- 1/2})$, the focal spot size as $0.744\theta ^{-3/4}$, and the depth of focus as $1.91\theta ^{- 3/2}$. Focusing by the resonant standing wave field leads to a new effect, a Rabi- like oscillation of the atom density. For the far-detuned lens, chromatic aberration is studied with the exact Fourier results. Similarly, the degradation of the focus that results from angular divergence in beams or thermal velocity distributions in traps is studied quantitatively with the exact Fourier method and understood analytically using the asymptotic results. Overall, we show that strong thin lens focusing is possible with modest laser powers and with currently achievable atomic beam characteristics.Comment: 21 pages, 11 figure

Downhole well log and core montages from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

This paper is not subject to U.S. copyright. The definitive version was published in Marine and Petroleum Geology 28 (2011): 561-577, doi:10.1016/j.marpetgeo.2010.03.016.The BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well was an integral part of an ongoing project to determine the future energy resource potential of gas hydrates on the Alaska North Slope. As part of this effort, the Mount Elbert well included an advanced downhole geophysical logging program. Because gas hydrate is unstable at ground surface pressure and temperature conditions, a major emphasis was placed on the downhole-logging program to determine the occurrence of gas hydrates and the in-situ physical properties of the sediments. In support of this effort, well-log and core data montages have been compiled which include downhole log and core-data obtained from the gas-hydrate-bearing sedimentary section in the Mount Elbert well. Also shown are numerous reservoir parameters, including gas-hydrate saturation and sediment porosity log traces calculated from available downhole well log and core data