5,860 research outputs found
Maximally entangled mixed states: Creation and concentration
Using correlated photons from parametric downconversion, we extend the
boundaries of experimentally accessible two-qubit Hilbert space. Specifically,
we have created and characterized maximally entangled mixed states (MEMS) that
lie above the Werner boundary in the linear entropy-tangle plane. In addition,
we demonstrate that such states can be efficiently concentrated, simultaneously
increasing both the purity and the degree of entanglement. We investigate a
previously unsuspected sensitivity imbalance in common state measures, i.e.,
the tangle, linear entropy, and fidelity.Comment: 4 pages, 3 figures, 1 table; accepted versio
Jerry-Building the Road to the Future: An Evaluation of the White Commission Report on Structural Alternatives for the Federal Courts of Appeals
For years, critics have argued that the United States Court of Appeals for the Ninth Circuit should be divided because it has grown too large to manage its caseload effectively.\u27 They blame the Ninth Circuit\u27s size for alleged increases in intra-circuit conflicts, inefficiency, delay, and a lack of collegiality among its judges.! In recent years, conservative
congressmen in the Pacific Northwest have criticized the San Francisco- based circuit for its liberal rulings on everything from the environment
to the death penalty
Analysis of Experimental Nucleation Data for Silver and SiO Using Scaled Nucleation Theory
The experimental vapor phase nucleation data of Nuth et al., for silver [J. A. Nuth, K. A. Donnelly, B. Donn, and L. U. Lilleleht, J. Chem. Phys. 77, 2639 (1982)] and SiO [J. A. Nuth and B. Donn, J. Chem. Phys. 85, 1116 (1986)] are reanalyzed using a scaled model for homogeneous nucleation [B. N. Hale, Phys. Rev. A 33, 4156 (1986)]. The approximation is made that the vapor pressure at the nucleation site is not diminished significantly from that at the source (crucible). It is found that the data for ln S have a temperature dependence consistent with the scaled theory ln SâÎΩ3/2 [Tc /T-1]3/2, and predict critical temperatures 3800 ± 200 K for silver and 3700 ± 200 K for SiO. One can also extract an effective excess surface entropy per atom Ω = 2.1 ± 0.1 and an effective surface tension Ï â 1500 - 0.45 T ergs/cm2 for the small silver clusters (assuming a range of nucleation rates from 105 to 1011 cm-3 s-1). The corresponding values for SiO are Ω â 1.7 ± 0.1 and Ï â 820 - 0.22 T ergs/cm2 (assuming a range of nucleation rates from 109 to 1012 cm-3 s-1)
2008 NE 1020 Cold Hardy Wine Grape Cultivar Trial Performance in 2010
In conjunction with the Northeast Regional Research project NE 1020 âMulti-state Evaluation of Wine Grape Cultivars and Clones,â Iowa State University established a cold hardy wine grape cultivar trial in 2008 at the ISU Horticulture Research Station (HRS) and Tabor Home Vineyards and Winery (THV) near Baldwin, IA. The Iowa trial evaluates the performance of Corot noir, La Crescent, Marquette, Petit Amie, NY 95.0301- 01, MN-1189, MN-1200, MN-1220, MN- 1235, MN-1258, with Frontenac and St. Croix serving as controls. Similar plantings were established in SD, NE, and MO, as well as in CT, IN, KY, and MI. This report summarizes the results for the 2010 growing season
PETIs as High-Temperature Resin-Transfer-Molding Materials
Compositions of, and processes for fabricating, high-temperature composite materials from phenylethynyl-terminated imide (PETI) oligomers by resin-transfer molding (RTM) and resin infusion have been developed. Composites having a combination of excellent mechanical properties and long-term high-temperature stability have been readily fabricated. These materials are particularly useful for the fabrication of high-temperature structures for jet-engine components, structural components on highspeed aircraft, spacecraft, and missiles. Phenylethynyl-terminated amide acid oligomers that are precursors of PETI oligomers are easily made through the reaction of a mixture of aromatic diamines with aromatic dianhydrides at high stoichiometric offsets and 4-phenylethynylphthalic anhydride (PEPA) as an end-capper in a polar solvent such as N-methylpyrrolidinone (NMP). These oligomers are subsequently cyclodehydrated -- for example, by heating the solution in the presence of toluene to remove the water by azeotropic distillation to form low-molecular-weight imide oligomers. More precisely, what is obtained is a mixture of PETI oligomeric species, spanning a range of molecular weights, that exhibits a stable melt viscosity of less than approximately 60 poise (and generally less than 10 poise) at a temperature below 300 deg C. After curing of the oligomers at a temperature of 371 deg C, the resulting polymer can have a glass-transition temperature (Tg) as high as 375 C, the exact value depending on the compositions
Distribution and risk assessment of trace metals in Leptodius exarata, surface water and sediments from Douglas Creek, Qua Iboe estuary
Five trace metals in Leptodius exarata, epipellic sediments and surface water from an
intertidal ecosystem in Niger Delta (Nigeria) were investigated to evaluate their spatial
distribution, degree of contamination, ecological and health risks. Results show Cd
(cadmium), Cr (chromium), Ni (nickel), Pb (lead) and Zn (zinc) concentrations in sediment
ranged between 0.550 â 1.142, 9.57 â 15.95, 9.15 â 13.96, 2.00 â 8.90 and 91.5 â 121.6
mg/kg dw, respectively; while L. exarata tissue metal content vary from 0.162 â 0.931, 3.81
â 8.62, 4.45 â 17.15, 1.90 â 7.35, and 125.55 â 269.75 mg/kg, dw, respectively. The
bioconcentration factor ranking for trace metals followed the sequence Zn>Ni>Pb >Cr>Cd.
High biota to sediment accumulation factor (BSAF) in L. exarata reveals a sentinel metal
bioindicator. Sediments from most sites were uncontaminated to moderately contaminated
(geoaccumulation, Igeo > 0) with Cd and Zn associated with anthropogenic intrusions. Low
mean-ERM (effect range-median) and mean-PEL (probable effect level) quotients of
sediments are observed, indicating lowâmedium degree of contamination with 30% and 21%
probability of being toxic. The multi-metal potential ecological risk index (RI) for the
intertidal ecosystem indicates lowâmoderate risk. Health risks associated with crabs (L.
exarata) consumption are significant in children than adults
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