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1

Silver(I) complexes of the weakly coordinating solvents SO(2) and CH(2)Cl(2): crystal structures, bonding, and energetics of [Ag(OSO)][Al{OC(CF(3))(3)}(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(CH(2)Cl(2))(2)][SbF(6)].  

PubMed

Pushing the limits of coordination chemistry: The most weakly coordinated silver complexes of the very weakly coordinating solvents dichloromethane and liquid sulfur dioxide were prepared. Special techniques at low temperatures and the use of weakly coordinating anions allowed structural characterization of [Ag(OSO)][Al{OC(CF(3))(3)}(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(Cl(2)CH(2))(2)][SbF(6)] (see figure). An investigation of the bonding shows that these complexes are mainly stabilized by electrostatic monopole-dipole interactions.The synthetically useful solvent-free silver(I) salt Ag[Al(pftb)(4)] (pftb=--OC(CF(3))(3)) was prepared by metathesis reaction of Li[Al(pftb)(4)] with Ag[SbF(6)] in liquid SO(2). The solvated complexes [Ag(OSO)][Al(pftb)(4)], [Ag(OSO)(2/2)][SbF(6)], and [Ag(CH(2)Cl(2))(2)][SbF(6)] were prepared and isolated by special techniques at low temperatures and structurally characterized by single-crystal X-ray diffraction. The SO(2) complexes provide the first examples of coordination of the very weak Lewis base SO(2) to silver(I). The SO(2) molecule in [Ag(OSO)][Al(pftb)(4)] is eta(1)-O coordinated to Ag(+), while the SO(2) ligands in [Ag(OSO)(2/2)][SbF(6)] bridge two Ag(+) ions in an eta(2)-O,O' (trans,trans) manner. [Ag(CH(2)Cl(2))(2)][SbF(6)] contains [Ag(CH(2)Cl(2))(2)](+) ions linked through [SbF(6)](-) ions to give a polymeric structure. The solid-state silver(I) ion affinities (SIA) of SO(2) and CH(2)Cl(2), based on bond lengths and corresponding valence units in the corresponding complexes and tensimetric titrations of Ag[Al(pftb)(4)] and Ag[SbF(6)] with SO(2) vapor, show that SO(2) is a weaker ligand to Ag(+) than the commonly used weakly coordinating solvent CH(2)Cl(2) and indicated that binding strength of SO(2) to silver(I) in the silver(I) salts increases with increasing size of the corresponding counteranion ([Al(pftb)(4)](-)>[SbF(6)](-)). The experimental findings are in good agreement with theoretical gas-phase ligand-binding energies of [Ag(L)(n)](+) (L=SO(2), CH(2)Cl(2); n=1, 2) and solid-state enthalpies obtained from Born-Fajans-Haber cycles by using the volume-based thermodynamics (VBT) approach. Bonding analysis (VB, NBO, MO) of [Ag(L)(n)](+) suggests that these complexes are almost completely stabilized by electrostatic interaction, that is, monopole-dipole interaction, with almost no covalent contribution by electron donation from the ligand orbitals into the vacant 5s orbital of Ag(+). All experimental findings and theoretical considerations demonstrate that SO(2) is less covalently bound to Ag(+) than CH(2)Cl(2) and support the thesis that SO(2) is a polar but non-coordinating solvent towards Ag(+). PMID:19449357

Decken, Andreas; Knapp, Carsten; Nikiforov, Grigori B; Passmore, Jack; Rautiainen, J Mikko; Wang, Xinping; Zeng, Xiaoqing

2009-06-22

2

Synthesis, structure, and bonding of weakly coordinating anions based on CN adducts.  

PubMed

The addition of alkali or silver salts of dicyanoamide (dca), tricyanomethanide (tcm) and tetracyanoborate (tcb) to a solution of B(C(6)F(5))(3) in diethyl ether affords salts containing very voluminous B(C(6)F(5))(3) adduct anions of the type [E(CN)(n)(-)] x [B(C(6)F(5))(3)](n): E = N (dca_nb with n = 1, 2; b = B(C(6)F(5))(3)); E = C (tcm_nb with n = 1, 2, 3), and E = B (tcb_nb with n = 1, 2, 3, 4). Salts bearing these anions such as B[(CN) x B(C(6)F(5))(3)](4)(-) (= [B(CN)(4)(-)] x [B(C(6)F(5))(3)](4)), C[(CN) x B(C(6)F(5))(3)](3)(-) (= [C(CN)(3)(-)] x [B(C(6)F(5))(3)](3)), and N[(CN) x B(C(6)F(5))(3)](2)(-) (=[N(CN)(2)(-)] x [B(C(6)F(5))(3)](2)) can be prepared in good yields. They are thermally stable up to over 200 degrees C and dissolve in polar organic solvents. Depending on the stoichiometry mono-, di-, tri-, or tetraadduct formation is observed. The solid state structures of dca_2b, tcm_3b and tcb_4b salts show only long cation...anion contacts and thereby weak interactions, large anion volumes and only small distortions of the dca, tcm or tcb core enwrapped between B(C(6)F(5))(3) groups. That is why these anions can be regarded as weakly coordinating anions. On the basis of B3LYP/6-31+G(d) computations the energetics, structural trends and charge transfer of the adduct anion formation were studied. Since tcm_3b and tcb_4b are easily accessible and can also be prepared in large quantities, these anions may be utilized as a true alternative to other widely used weakly coordinating anions. Moreover, for both steric and electronic reasons it seems reasonable to expect that as counterions for cationic early transition metal catalysts such anions may show reduced ion pairing and hence increased catalytic activity. PMID:19469540

Bernsdorf, Arne; Brand, Harald; Hellmann, Robert; Köckerling, Martin; Schulz, Axel; Villinger, Alexander; Voss, Karsten

2009-07-01

3

Rhenium complexes with weakly coordinating solvent ligands, cis[Re(PR{sub 3})(CO){sub 4}(L)][BAr{sub F}], L = CH{sub 2}Cl{sub 2}, Et{sub 2}O, NC{sub 5}F{sub 5}: Decomposition to chloride-bridged dimers in CH{sub 2}Cl{sub 2} solution  

SciTech Connect

The solvent-coordinated complexes [cis-Re(CO){sub 4}(PR{sub 3})(S)][BAr{sub F}] (R = Ph, {sup i}Pr, Cy, BAr{sub F} = [B(3,5-(CF{sub 3}){sub 2}C{sub 6}H{sub 3}){sub 4}]{sup {minus}}) for S = Et{sub 2}O, CH{sub 2}Cl{sub 2}, and NC{sub 5}F{sub 5} have been prepared from reaction of the neutral methyl precursors, cis-Re-(CO){sub 4}(PR{sub 3})(Me), with either [H(OEt{sub 2}){sub 2}][BAr{sub F}] or [Ph{sub 3}C][BAr{sub F}] in the appropriate solvent. A crystal structure of the complex [cis-Re(CO){sub 4}(P{sup i}Pr{sub 3})(ClCH{sub 2}Cl)][BAr{sub F}] shows that the dichloromethane ligand is coordinated through one chlorine, with an Re-Cl distance of 2.554(2) {angstrom}. The first example of a structurally characterized pentafluoropyridine complex of rhenium was also determined, [cis-Re(CO){sub 4}(P{sup i}Pr{sub 3})(NC{sub 5}F{sub 5})][BAr{sub F}], with an Re-N distance of 2.319(5) {angstrom}. Activation of C-Cl bonds in the dichloromethane complexes result in the formation of the chloride-bridged dimers, {l_brace}[cis-Re(CO){sub 4}(PR{sub 3})]{sub 2}({mu}-Cl){r_brace}{l_brace}BAr{sub f}{r_brace}, and the X-ray structures of the Ph and Cy derivatives were determined.

Huhmann-Vincent, J.; Scott, B.L.; Kubas, G.J. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.

1999-01-11

4

The coordinate-space Hartree-Fock-Bogoliubov approach for describing weakly-bound deformed nuclei  

NASA Astrophysics Data System (ADS)

The solution of coordinate-space Hartree-Fock-Bogoliubov approach can provide accurate descriptions of weakly-bound nuclei, in which the continuum effect plays an important role. However, this is not an easy task of solving HFB equations for non-spherical nuclei in the continuum. We discuss the exotic shapes obtained by coordinate-space HFB calculations within a large box size on China's Tianhe-1A supercomputer. Calculations with different box sizes are performed to distinguish the quasi-particle resonances and the non-resonance continuum.

Pei, J. C.; Zhang, Y. N.; Xu, F. R.

2013-05-01

5

Chemistry with weakly-coordinating fluorinated alkoxyaluminate anions: Gas phase cations in condensed phases?  

Microsoft Academic Search

Many very simple and fundamentally important cations were initially observed in the gas phase, e.g. inside a mass spectrometer or even in space. The question arises, how to stabilize and study these gas phase cations in condensed phases. In this review, our work on the use of weakly-coordinating anions (WCAs) of type [Al(ORF)4]? and [(RFO)3Al–F–Al(ORF)3]? to investigate structural and chemical

Ingo Krossing; Andreas Reisinger

2006-01-01

6

Weakness  

MedlinePLUS

Lack of strength; Muscle weakness ... weak, but there is no real loss of strength. For example, you may feel weak if you ... flu . Objective means there is a loss of strength that can be noted during a physical exam.

7

Programme coordinators' perceptions of strengths, weaknesses, opportunities and threats associated with school nutrition programmes.  

PubMed

OBJECTIVE: As part of a larger evaluation of school nutrition programmes (SNP), the present study examined programme coordinators' perceptions of strengths, weaknesses, opportunities and threats (SWOT) regarding their SNP and public health professionals' support. DESIGN: Qualitative interviews were conducted with twenty-two of eighty-one programme coordinators who had completed a programme evaluation survey. Interviews followed a SWOT framework to evaluate programmes and assessed coordinators' perceptions regarding current and future partnerships with public health professionals. SETTING: The study was conducted in a large, urban region within Ontario. SUBJECTS: The twenty-two coordinators who participated represented a cross-section of elementary, secondary, Public and Catholic schools. RESULTS: SNP varied enormously in foods/services offered, how they offered them and perceived needs. Major strengths included universality, the ability to reach needy students and the provision of social opportunities. Major weaknesses included challenges in forming funding partnerships, lack of volunteers, scheduling and timing issues, and coordinator workload. Common threats to effective SNP delivery included lack of sustainable funding, complexity in tracking programme use and food distribution, unreliable help from school staff, and conflicts with school administration. Opportunities for increased public health professionals' assistance included menu planning, nutrition education, expansion of programme food offerings, and help identifying community partners and sustainable funding. CONCLUSIONS: The present research identified opportunities for improving SNP and strategies for building on strengths. Since programmes were so diverse, tailored strategies are needed. Public health professionals can play a major role through supporting menu planning, food safety training, access to healthy foods, curriculum planning and by building community partnerships. PMID:23768442

Valaitis, Renata F; Hanning, Rhona M; Herrmann, Isabela S

2013-06-17

8

Deformed Coordinate-Space Hartree-Fock-Bogoliubov Approach to Weakly Bound Nuclei and Large Deformations  

SciTech Connect

The coordinate space formulation of the Hartree-Fock-Bogoliubov (HFB) method enables self-consistent treatment of mean field and pairing in weakly bound systems whose properties are affected by the particle continuum space. Of particular interest are neutron-rich, deformed drip-line nuclei which can exhibit novel properties associated with neutron skin. To describe such systems theoretically, we developed an accurate 2D lattice Skyrme-HFB solver HFB-AX based on B-splines. Compared to previous implementations, we made a number of improvements aimed at boosting the solver's performance. These include: explicit imposition of axiality and space inversion, use of the modified Broyden's method to solve self-consistent equations, and a partial parallelization of the code. HFB-AX has been benchmarked against other HFB solvers, both spherical and deformed, and the accuracy of the B-spline expansion was tested by employing the multi-resolution wavelet method. Illustrative calculations are carried out for stable and weakly bound nuclei at spherical and very deformed shapes, including constrained fission pathways. In addition to providing new physics insights, HFB-AX can serve as a useful tool to assess the reliability and applicability of coordinate-space and configuration-space HFB solvers, both existing and in development.

Pei, Junchen [ORNL; Stoitsov, M. V. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Fann, G. I. [Oak Ridge National Laboratory (ORNL); Nazarewicz, W. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Schunck, N. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Xu, F. R. [Peking University

2008-01-01

9

Deformed coordinate-space Hartree-Fock-Bogoliubov approach to weakly bound nuclei and large deformations  

NASA Astrophysics Data System (ADS)

The coordinate-space formulation of the Hartree-Fock-Bogoliubov (HFB) method enables the self-consistent treatment of mean field and pairing in weakly bound systems whose properties are affected by the particle continuum space. Of particular interest are neutron-rich, deformed drip-line nuclei, which can exhibit novel properties associated with neutron skin. To describe such systems theoretically, we developed an accurate two-dimensional lattice Skyrme-HFB solver HFB-AX based on basis (or B)-splines. Compared to previous implementations, ours incorporated a number of improvements aimed at boosting the solver's performance. These include the explicit imposition of axiality and space inversion, use of the modified Broyden method to solve self-consistent equations, and a partial parallelization of the code. HFB-AX has been compared with other HFB codes, both spherical and deformed, and the accuracy of the B-spline expansion was tested by employing the multiresolution wavelet method. Illustrative calculations are carried out for stable and weakly bound nuclei at spherical and very deformed shapes, including constrained fission pathways. In addition to providing new physics insights, HFB-AX can serve as a useful tool to assess the reliability and applicability of coordinate-space and configuration-space HFB frameworks, both existing and in development.

Pei, J. C.; Stoitsov, M. V.; Fann, G. I.; Nazarewicz, W.; Schunck, N.; Xu, F. R.

2008-12-01

10

Molecular dynamics study of the weakly solvent dependent relaxation dynamics following chlorine dioxide photoexcitation  

NASA Astrophysics Data System (ADS)

The solvation dynamics following photoexcitation of chlorine dioxide (OClO) in different solvents are investigated by classical molecular dynamics. Following previous work on the aqueous response to OClO photoexcitation [J. Chem. Phys. 118, 4563 (2003)], the present study considers the response of chloroform and cyclohexane; these three liquids present unique solvent environments that differ significantly in both polarity and structure. The study is designed to ascertain the origin of the solvent-invariant homogeneous linewidth associated with OClO photoexcitation and to confirm, at the molecular level, whether the relaxation dynamics are similar across dissimilar solvents due to chance or a common relaxation origin. The results obtained here are used to predict the time scale of solvent-induced optical dephasing, and excellent agreement with experiment is observed for all solvents. Analysis demonstrates that the solvation dynamics of OClO are dominated by short-ranged mechanical solute-solvent interactions regardless of the identity and electrostatic properties of the solvent. Low-frequency translational motions dominate the coupling spectrum, and virtually no contribution to energy gap relaxation is achieved through intramolecular solvent motions. The invariant homogeneous linewidth is attributed to the similarity in the primary response of all solvents to OClO photoexcitation.

Brooksby, Craig; Prezhdo, Oleg V.; Reid, Philip J.

2003-11-01

11

Reversible and selective solvent adsorption in layered metal-organic frameworks by coordination control.  

PubMed

With various functionalities in the framework and high thermal stability, metal-organic frameworks (MOFs) have been extensively studied for the applications in adsorption and separation. In last decade, synthesizing new MOFs with desired structures and improved chemical stability to meet these applications has drawn great attention. In this report, by using an organic ligand with azolate moiety, benzo-bis(imidazole) (H2BBI), we synthesized two new 2D layered MOF structures with distinct topologies. Framework 1 {[Zn2Cl2(BBI)(MSM)2]n, MSM=methylsulfonylmethane}, constructed from tetrahedral Zn(II) and BBI, maintains its structure in organic solvents, such as methanol and benzene, and even in water. Meanwhile, framework 2 {[Cd2Cl2(BBI)(DMSO)2]n, DMSO=dimethyl sulfoxide} differs from framework 1, and is assembled from trigonal bipyramidal Cd(II) and square planar BBI. By removing the DMSO molecules coordinated to Cd(II) (25 weight% of the structure), 2 could transform to 3 {[Cd2Cl2(BBI)]n}, which was further characterized by high-resolution powder X-ray diffraction. The solvent-free 3 retains the original connectivity within each layer, and is capable of reversible and selective adsorption of DMSO molecules. The bistable four- and five-coordinated geometry exchange of Cd(II) is the origin of this adsorption with improved selectivity and capacity. PMID:24183447

Yin, Xinbo; Chen, Haohong; Song, Yuna; Wang, Yang; Li, Qiaowei; Zhang, Lijuan

2013-09-21

12

Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents  

SciTech Connect

Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg4(3,5-PDC)4(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network with a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing multiple desolvation routes, we were unable to measure BET surface areas greater than 51.9 m{sup 2}/g for compound 1.

Banerjee, Debasis; Finkelstein, Jeffrey; Smirnov, A.; Forster, Paul M.; Borkowski, Lauren A.; Teat, Simon J.; Parise, John B. (UNLV); (SUNYB); (LBNL)

2012-10-11

13

Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents  

SciTech Connect

Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg{sub 4}(3,5-PDC){sub 4}(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network with a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing multiple desolvation routes, we were unable to measure BET surface areas greater than 51.9 m{sup 2}/g for compound 1.

D Banerjee; J Finkelstein; A Smirnov; P Forster; L Borkowski; S Teat; J Parise

2011-12-31

14

Coordination polymers formed in solution and in solvent-free environment. Structural transformation due to interstitial solvent removal revealed by X-ray powder diffraction.  

PubMed

The crystal-to-powder transformation induced by solvent removal has been examined through a direct comparison of the structures of the solvated and the unsolvated coordination products determined by single crystal and powder X-ray diffraction, respectively. PMID:15983645

Dikarev, Evgeny V; Li, Bo; Chernyshev, Vladimir V; Shpanchenko, Roman V; Petrukhina, Marina A

2005-05-27

15

Symmetry breaking in the relaxed S(1) excited state of bianthryl derivatives in weakly polar solvents.  

PubMed

The flash-photolysis time-resolved microwave conductivity technique (FP-TRMC) has been used to investigate the nature of the relaxed S(1) state of 9,9'-bianthryl (AA), 10-cyano-9,9'-bianthryl (CAA), and 10,10'-dicyano-9,9'-bianthryl (CAAC). Changes in both the real, Deltaepsilon' (dielectric constant), and imaginary, Deltaepsilon' ' (dielectric loss), components of the complex permittivity have been measured. The dielectric loss transients conclusively demonstrate the dipolar nature of S(1) for all three compounds in the pseudopolar solvents benzene and 1,4-dioxane, and even in the nonpolar solvents n-hexane and cyclohexane. The required symmetry breaking is considered to result from density and structural fluctuations in the solvent environment. The dipole relaxation times for AA (CAAC) are ca. 2 ps for the alkanes and 7.9 (5.3) and 14 (14) ps for benzene and dioxane, respectively. The time scale of dipole relaxation for the symmetrical compounds is much shorter than that for rotational diffusion and is attributed to intramolecular, flip-flop dipole reversal via a neutral excitonic state. The dipole moment of the transient dipolar state is estimated to be ca. 8 D, that is much lower than the value of ca. 20 D determined from the solvatochromic shifts in the fluorescence in intermediate to highly polar solvents which corresponds to close to complete charge separation. For the asymmetric compound, CAA, a dipole moment close to 20 D is found in all solvents, including n-hexane. Dipole relaxation in this case occurs on a time scale of several hundred picoseconds and is controlled mainly by diffusional rotation of the molecules. The mechanism and kinetics of formation of the dipolar excited states are discussed in the light of these results. PMID:11457397

Piet, J J; Schuddeboom, W; Wegewijs, B R; Grozema, F C; Warman, J M

2001-06-01

16

Coordination conversion of cobalt(II) in binary aqueous-organic solvents  

SciTech Connect

It has been shown that the thermochromic conversions of cobalt(II) in binary solvents are influenced by a number of factors: the nature of the solvent, the strength of the complexes of octahedral symmetry formed, the outer-sphere influence of the solvent on the complexes, the form of the anion, the solvation of the participants in the reaction, and the interaction of the components of the solvent with one another. A correlation between the strength and the spectral position of the absorption bands of the complexes of the activator has been established, and a spectroscopic criterion for selecting the solvents has been proposed. The expediency of using binary solvents to create effective thermochromic media with variable phototransmission has been substantiated.

Khvostova, N.O.; Karapetyan, G.O.; Yanush, O.V.

1985-11-01

17

The facile preparation of weakly coordinating anions: structure and characterisation of silverpolyfluoroalkoxyaluminates AgAl(ORF)4, calculation of the alkoxide ion affinity.  

PubMed

Purified LiAlH4 reacts with fluorinated alcohols HORF to give LiAl(ORF)4 (RF=-CH(CF3)2, 2a; -C(CH3)(CF3)2, 2b; -C(CF3)3, 2c) in 77 to 90% yield. The crude lithium aluminates LiAl(ORF)4 react metathetically with AgF to give the silver aluminates AgAl(ORF)4 (RF=-CH(CF3)2, 3a; -C(CH3)(CF3)2, 3b; -C(CF3)3, 3c) in almost quantitative yield. The solid-state structures of solvated 3a-c showed that the silver cation is only weakly coordinated (CN(Ag)=6-10; CN = coordination number) by the solvent and/or weak cation - anion contacts Ag-X (X=O, F, Cl, C). The strength of the Ag-X contacts of 3a-c was analysed by Brown's bond-valence method and then compared with other silver salts of weakly coordinating anions (WCAs), for example [CB11H6Cl6]- and [M(OTeF5)n]- (M=B, Sb, n=4, 6). Based on this quantitative picture we showed that the Al[OC(CF3)3]4 anion is one of the most weakly coordinating anions known. Moreover, the AgAl(ORF)4 species are certainly the easiest WCAs to access preparatively (20 g in two days), additionally at low cost. The Al-O bond length of Al(ORF)4- is shortest in the sterically congested Al[OC(CF3)3]4- anion-which is stable in H2O and aqueous HNO3 (35 weight%)--and indicates a strong and highly polar Al-O bond that is resistant towards heterolytic alkoxide ion abstraction. This observation was supported by a series of HF-DFT calculations of OR-, Al(OR)3 and Al(OR)4- at the MPW1PW91 and B3LYP levels (R= CH3, CF3, C(CF3)3). The alkoxide ion affinity (AIA) is highest for R=CF3 (AlA=384 +/- 9 kJ x mol(-1)) and R= C(CF3)3 (AIA=390 +/- 3 kJ x mol(-1)), but lowest for R=CH3 (AIA=363 +/- 7 kJ X mol(-1)). The gaseous AL(ORF)4-anions are stable against the action of the strong Lewis acid ALF3(g) by 88.5 +/- 2.5 (RF=CF3) and 63 +/- 12 kJ X mol(-1) (RF=C(CF3)3), while AL(OCH3)4- decomposes with -91 +/- 2 kJ X mol(-1). Therefore the presented fluorinated aluminates AL(ORF)4- appear to be ideal candidates when large and resistant WCAs are needed, for example, in cationic homogenous catalysis, for highly electrophilic cations or for weak cationic Lewis acid/base complexes. PMID:11271536

Krossing, I

2001-01-19

18

Coordination  

NSDL National Science Digital Library

Coordination is an organized working together of muscles and groups of muscles aimed at bringing about a purposeful movement such as walking or standing. Coordination involves timing and concentration.

Olivia Worland (Purdue University;Biological Sciences)

2008-06-06

19

Induced morphology control of Ln-asparagine coordination polymers from the macro to nanoscopic regime in polar solvent-water mixtures.  

PubMed

A bottom-up approach is presented here for morphology control of Ln-asparagine (Asn) coordination polymers (CPs) from the macro to nanoscopic regime by tuning solvent polarity based on the ?* solvent polarity scale in polar solvent-water mixed solutions. By a simple hydrothermal treatment, large macroporous spheres with sizes up to millimeters were obtained in ethanol (?*: 0.54)-water mixtures, and their formation mechanism was proved to be particle aggregation together with a hollowing process based on Ostwald ripening. Other solvents with increasing polarity were also used, and submicrometer spheres as well as fine nanoparticles were prepared in acetone (?*: 0.71) and DMF (?*: 0.88), respectively. When dioxane (?*: 0.55) was used here, whose ?* value is similar to ethanol, large macroporous spheres were also prepared. Furthermore, with Ce- and La-Asn CPs large spheres as precursors, after calcination, ceria and lanthana large spheres with hierarchical structures were fabricated, respectively. Considering that many growth media of CPs are single solvent systems, designing certain solvents mixtures and tuning their polarity would bring us new opportunities to achieve morphology and composition control of CPs materials. PMID:23111349

Yang, Ming; Shen, Zhurui; Chen, Tiehong; Bi, Huichao; Yang, Bin; Xu, Wei

2013-01-28

20

Merging strong and weak coordination motifs in the integrative self-sorting of a 5-component trapezoid and scalene triangle.  

PubMed

In a dynamic six-component library, the formation of the rather weak HETPYP-I complexation can be enforced by exploiting the orthogonality and high stability of its counterpart in the sorting process, a HETTAP complex. The concept was used in a follow-up integrative self-sorting, enabling the formation of two five-component supramolecular structures: a trapezoid and a scalene triangle. PMID:23896740

Saha, Manik Lal; Bats, Jan W; Schmittel, Michael

2013-09-14

21

Solvent coordination in gas-phase [Mn.(H(2)O)(n)](2+) and [Mn.(ROH)(n)](2+) complexes: theory and experiment.  

PubMed

An experimental gas-phase study of the intensities and fragmentation patterns of [Mn.(H(2)O)(n)](2+) and [Mn.(ROH)(n)](2+) complexes shows the combinations [Mn.(H(2)O)(4)](2+) and [Mn.(ROH)(4)](2+) to be stable. Evidence in complexes involving the alcohols methanol, ethanol, 1-propanol, and 2-propanol favors preferential fragmentation to [Mn.(ROH)(4)](2+), whereas the fragmentation data for water is less clear. Supporting density functional calculations show that both [Mn.(H(2)O)(4)](2+) and [Mn.(MeOH)(4)](2+) adopt stable tetrahedral configurations, similar to those proposed for biochemical systems where solvent availability and coordination is restricted. Calculated incremental binding energies show a gradual decline on going from one to six solvent molecules, with a step occurring between four and five molecules. The addition of further solvent molecules to the stable [Mn.(MeOH)(4)](2+) unit shows a preference for [Mn.(MeOH)(4)(MeOH)(1,2)](2+) structures, where the extra molecules occupy hydrogen-bonded sites in the form of a secondary solvation shell. Very similar behavior is seen on the part of water. As part of an analysis of the experimental data, the calculations have explored the influence different spins states of Mn(2+) have on solvent geometry. It is concluded that the experimental observations are best reproduced when the central Mn(2+) ion is in the high-spin (6)S ground state. The results are also considered in terms of the biochemical activity of Mn(2+) where the ion is capable of isomorphous substitution with Zn(2+), which itself exhibits a preference for tetrahedral coordination. PMID:12515526

Cox, Hazel; Akibo-Betts, Glen; Wright, Rossana R; Walker, Nicholas R; Curtis, Sharon; Duncombe, Bridgette; Stace, Anthony J

2003-01-01

22

Micromolding of a Highly Fluorescent Reticular Coordination Polymer: Solvent-Mediated Reconfigurable Polymerization in a Soft Lithographic Mold  

SciTech Connect

Coordination polymerization of pyridine-based ligands and zinc or silver ions was controlled by soft lithographic micromolding in capillaries. The polymer patterns that are produced are highly fluorescent and supramolecularly structured.

Y You; H Yang; J Chung; J Kim; Y Jung; S Park

2011-12-31

23

Boron-dipyrromethene-functionalized hemilabile ligands as "turn-on" fluorescent probes for coordination changes in weak-link approach complexes.  

PubMed

Herein we report a new class of hemilabile ligands with boron-dipyrromethene (Bodipy) fluorophores that, when complexed to Pt(II), can signal changes in coordination mode through changes in their fluorescence. The ligands consist of phosphino-amine or phosphino-thioether coordinating moieties linked to the Bodipy's meso carbon via a phenylene spacer. Interestingly, this new class of ligands can be used to signal both ligand displacement and chelation reactions in a fluorescence "turn-on" fashion through the choice of weakly binding heteroatom in the hemilabile moiety, generating up to 10-fold fluorescence intensity increases. The Pt(II) center influences the Bodipy emission efficiency by regulating photoinduced electron transfer between the fluorophore and its meso substituent. The rates at which the excited Bodipy-species generate singlet oxygen upon excitation suggest that the heavy Pt(II) center also influences Bodipy's emission efficiency by affecting intersystem crossing from the Bodipy excited singlet to excited triplet states. This signaling strategy provides a quantitative read-out for changes in coordination mode and potentially will enable the design of new molecular systems for sensing and signal amplification. PMID:23570551

Lifschitz, Alejo M; Shade, Chad M; Spokoyny, Alexander M; Mendez-Arroyo, Jose; Stern, Charlotte L; Sarjeant, Amy A; Mirkin, Chad A

2013-04-09

24

Exciplex fluorescence as a diagnostic probe of structure in coordination polymers of Zn2+ and 4,4'-bipyridine containing intercalated pyrene and enclathrated aromatic solvent guests.  

PubMed

Coordination polymers based on Zn(II)-4,4'-bipyridine (Zn-bipy) frameworks containing pyrene intercalated between adjacent layers and aromatic solvent molecules enclathrated within the framework cavities have been prepared and characterized for the first time. These compounds are highly fluorescent, and show broad, featureless emission spectra significantly red-shifted relative to pyrene monomer fluorescence; this has been assigned to pyrene-bipy exciplex emission. Single-crystal X-ray structural analysis shows that the presence of the aromatic solvent molecule within the cavities has a profound effect on the architecture of these frameworks: in the case of benzene, toluene, p-xylene, and chlorobenzene, the Zn-bipy framework consists of 1-D ladders, whereas in the case of o-dichlorobenzene (the largest solvent guest), the framework was based on a 2-D square grid. This difference in stoichiometry and architecture was also reflected in significant differences in the fluorescence of these coordination polymers, with three of the four compounds with 1-D ladder geometries having similar fluorescence maxima (ca. 520 nm) and lifetimes (ca. 70 ns), whereas the compound with square grid topology had a significantly blue-shifted maximum (ca. 460 nm) and shorter lifetime (ca. 42 ns). It is proposed that exciplexes form upon excitation of ground-state complexes, involving face-to-face bipy/pyrene complexes (pi-pi stacking interactions) in the case of the 1-D ladder structures, but edge-to-face bipy/pyrene and pyrene/o-dichlorobenzene complexes (C-H...pi interactions) in the case of the 2-D square grid structure. PMID:17602624

McManus, Gregory J; Perry, John J; Perry, Mark; Wagner, Brian D; Zaworotko, Michael J

2007-06-30

25

Microscopic solvation of a lithium atom in water-ammonia mixed clusters: solvent coordination and electron localization in presence of a counterion.  

PubMed

The microsolvation structures and energetics of water-ammonia mixed clusters containing a lithium atom, i.e., Li(H(2)O)(n)(NH(3)), n = 1-5, are investigated by means of ab initio theoretical calculations. Several structural aspects such as the solvent coordination to the metal ion and binding motifs of the free valence electron of the metal are investigated. We also study the energetics aspects such as the dependence of vertical ionization energies on the cluster size, and all these structural and energetics aspects are compared to the corresponding results of previously studied anionic water-ammonia clusters without a metal ion. It is found that the Li-O and Li-N interactions play a very important role in stabilizing the lithium-water-ammonia clusters, and the presence of these metal ion-solvent interactions also affect the characteristics of electron solvation in these clusters. This is seen from the spatial distribution of the singly occupied molecular orbital (SOMO) which holds the ejected valence electron of the Li atom. For very small clusters, SOMO electron density is found to exist mainly at the vicinity of the Li atom, whereas for larger clusters, it is distributed outside the first solvation shell. The free dangling hydrogens of water and ammonia molecules are involved in capturing the SOMO electron density. In some of the conformers, OH{e}HO and OH{e}HN types of interactions are found to be present. The presence of the metal ion at the center of the cluster ensures that the ejected electron is solvated at a surface state only, whereas both surface and interiorlike states were found for the free electron in the corresponding anionic clusters without a metal ion. The vertical ionization energies of the present clusters are found to be higher than the vertical detachment energies of the corresponding anionic clusters which signify a relatively stronger binding of the free electron in the presence of the positive metal counterion. The shifts in different vibrational frequencies are also calculated for the larger clusters, and the results are discussed for some of the selective modes of water and ammonia molecules that are directly influenced by the location and hydrogen bonding state of these molecules in the clusters. PMID:18624542

Pratihar, Subha; Chandra, Amalendu

2008-07-14

26

Microscopic solvation of a lithium atom in water-ammonia mixed clusters: Solvent coordination and electron localization in presence of a counterion  

SciTech Connect

The microsolvation structures and energetics of water-ammonia mixed clusters containing a lithium atom, i.e., Li(H{sub 2}O){sub n}(NH{sub 3}), n=1-5, are investigated by means of ab initio theoretical calculations. Several structural aspects such as the solvent coordination to the metal ion and binding motifs of the free valence electron of the metal are investigated. We also study the energetics aspects such as the dependence of vertical ionization energies on the cluster size, and all these structural and energetics aspects are compared to the corresponding results of previously studied anionic water-ammonia clusters without a metal ion. It is found that the Li-O and Li-N interactions play a very important role in stabilizing the lithium-water-ammonia clusters, and the presence of these metal ion-solvent interactions also affect the characteristics of electron solvation in these clusters. This is seen from the spatial distribution of the singly occupied molecular orbital (SOMO) which holds the ejected valence electron of the Li atom. For very small clusters, SOMO electron density is found to exist mainly at the vicinity of the Li atom, whereas for larger clusters, it is distributed outside the first solvation shell. The free dangling hydrogens of water and ammonia molecules are involved in capturing the SOMO electron density. In some of the conformers, OH(e)HO and OH(e)HN types of interactions are found to be present. The presence of the metal ion at the center of the cluster ensures that the ejected electron is solvated at a surface state only, whereas both surface and interiorlike states were found for the free electron in the corresponding anionic clusters without a metal ion. The vertical ionization energies of the present clusters are found to be higher than the vertical detachment energies of the corresponding anionic clusters which signify a relatively stronger binding of the free electron in the presence of the positive metal counterion. The shifts in different vibrational frequencies are also calculated for the larger clusters, and the results are discussed for some of the selective modes of water and ammonia molecules that are directly influenced by the location and hydrogen bonding state of these molecules in the clusters.

Pratihar, Subha; Chandra, Amalendu [Department of Chemistry, Indian Institute of Technology, Kanpur 208016 (India)

2008-07-14

27

Modulating the structures of copper(I) cyanide coordination polymers by rigid bis(imidazole) ligands and solvents: An experimental and theoretical study  

NASA Astrophysics Data System (ADS)

Four novel copper(I) cyanide coordination polymers, namely, Cu2(CN)2(L1) (1), Cu2(CN)2(L2) (2), Cu2(CN)2(L3) (3) and Cu2(CN)2(L3) (4), have been prepared via the reaction of Cu2+, [Fe(CN)6]4- and three structurally related rigid bis(imidazole) ligands 1,4-bis(1-imidazolyl)benzene (L1), 4,4?-bis(1-imidazolyl)biphenyl (L2) and 5-methyl-1,3-bis(1-imidazolyl)benzene(L3) under solvothermal conditions. Although all complexes contain 1D copper(I) cyanide chains, they have completely different structures of 21 helical chain, zigzag chain, and meso-helical chain for complexes 1, 2, and 3, respectively. Complex 1 presents a distorted 2D (6, 3) layer, and further forms a 3D supramolecular structure by ?⋯? interactions. Complex 2 shows a 3D network with (10, 3)-b topology and exhibits an interesting 3-fold interpenetration structures attributed Class Ia type. Most interestingly, complexes 3 and 4 are a pair of polymorphs, which are yielded simply depending upon the reaction solvent, and also generate a 3D network with (10, 3)-b topology, which display an interesting 4-fold interpenetration, and belong to unusual Class IIIa type. Meanwhile, the nature of metal-ligand bonds in all complexes was further confirmed by density functional theoretical calculations. It was found that the metal-ligand bonds are basically intermediate and covalent dominant interactions in all complexes. An extended analysis of the experimental and theoretical results indicates that the organic ligands play a crucial role in the self-assembly of the final product structures. Moreover, the thermal properties of complexes 1-3 have also been investigated.

Huang, Rong-Yi; Xu, Heng; Ye, Shi-Yong; Wu, Gen-Hua; Zhao, Xiu-Qin; Wang, Yan; Liu, Guang-Xiang

2013-03-01

28

Coordination Science: Challenges and Directions  

Microsoft Academic Search

Several distinct kinds of coordination technology have evolved to support effective coordination in cooperative work. This paper reviews some of the major weaknesses with current coordination technology and suggests several technical directions for addressing these weaknesses. These directions include developing semi-structured process representations that explicitly capture cooperative work inter-dependencies, exploiting advanced product and software design technologies for process design, and

Mark Klein

1996-01-01

29

PMR study of the composition of the first coordination sphere of Co(II) and Ni(II) ions in mixed solvents  

Microsoft Academic Search

The paramagnetic shifts have been measured in the PMR spectra of DMSO, DMF, and a number of alcohols in aqueous solutions in the presence of cobalt and nickel nitrates at room temperature. The introduction of all the compounds studied (L) into the first coordination sphere of the Co(ll) and Ni(ll) ions has been de- tected. A method has been proposed

V. V. Matveev

1981-01-01

30

Weak deeply virtual Compton scattering  

Microsoft Academic Search

We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross

A. V. Radyushkin; A. Psaker

2007-01-01

31

Universality of weak selection  

NASA Astrophysics Data System (ADS)

Weak selection, which means a phenotype is slightly advantageous over another, is an important limiting case in evolutionary biology. Recently, it has been introduced into evolutionary game theory. In evolutionary game dynamics, the probability to be imitated or to reproduce depends on the performance in a game. The influence of the game on the stochastic dynamics in finite populations is governed by the intensity of selection. In many models of both unstructured and structured populations, a key assumption allowing analytical calculations is weak selection, which means that all individuals perform approximately equally well. In the weak selection limit many different microscopic evolutionary models have the same or similar properties. How universal is weak selection for those microscopic evolutionary processes? We answer this question by investigating the fixation probability and the average fixation time not only up to linear but also up to higher orders in selection intensity. We find universal higher order expansions, which allow a rescaling of the selection intensity. With this, we can identify specific models which violate (linear) weak selection results, such as the one-third rule of coordination games in finite but large populations.

Wu, Bin; Altrock, Philipp M.; Wang, Long; Traulsen, Arne

2010-10-01

32

Structural chemistry and solvent properties of dimethylsulfoxide  

SciTech Connect

An examination of the chemical environment and structure of dimethylsulfoxide (DMSO) in the solid state leads to a description of its bonding properties that is useful in proposing structures for solvation complexes in DMSO solutions. The O atom acts as a type A (hard) Lewis base of strength similar to or somewhat greater than that of water and is capable of bonding to metal cations with oxidation states between +1 and +3. The methylprotons are weakly acid and are found to form bonds to weak bases such as ClO/sub 4//sup -/, No/sub 3//sup -/, and halogen ions. DMSO is an ideal solvent for compounds of strongly acid cations and weakly basic anions. Bonding also occurs through S to type-B (soft) Lewis acids (groups 8-10) particularly when the soft Lewis acid is already coordinated to electron donor groups. In these cases the oxygen basicity is dependent on the electron donating or withdrawing power of the type-B acid.

Brown, I.D.

1987-03-01

33

Weak deeply virtual Compton scattering  

SciTech Connect

We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high-intensity neutrino beam facilities.

Psaker, A.; Radyushkin, A. V. [Physics Department, Old Dominion University, Norfolk, Virginia 23529 (United States); Jefferson Lab, 12000 Jefferson Avenue, Newport News, Virginia 23606 (United States); Melnitchouk, W. [Jefferson Lab, 12000 Jefferson Avenue, Newport News, Virginia 23606 (United States)

2007-03-01

34

Weak Deeply Virtual Compton Scattering  

SciTech Connect

We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high intensity neutrino beam facilities.

Ales Psaker; Wolodymyr Melnitchouk; Anatoly Radyushkin

2007-03-01

35

Solvent substitution  

SciTech Connect

The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

Not Available

1990-01-01

36

The influence of the macroring structure on the solvation of nonplanar porphyrins in organic solvents  

NASA Astrophysics Data System (ADS)

An analysis of the calorimetric data and X-ray structure and fluorescence characteristics revealed the existence of a linear correlation between the enthalpies of solution of saddle-shaped nonplanar porphyrins (H2P) in various solvents and the parameters of molecule nonplanarity in the crystalline state and in solution. This correlation is explained by a decrease in the energy of the crystal lattice of saddle-shaped nonplanar porphyrins compared with other distortion types. The deviation from the planar structure of macrocyclic compounds weakly influences the character of their solvation by organic solvents. Acid-base interaction accompanied by the formation of H-bonded associates of nonplanar H2P with coordinating solvents decreases the relative solvation of their molecules by 5-10 kJ/mol. The extracoordination ability of nonplanar zinc porphyrinates is weakened compared with their planar analogues.

Berezin, D. B.; Semeikin, A. S.; Berezin, M. B.

2009-08-01

37

Solvent effect in the Walden inversion reactions  

NASA Astrophysics Data System (ADS)

The solvent effect on the fluoride exchange reaction has been studied by means of ab initio calculations using the 3-21G basis set. It is shown that the motion of the solvent molecules is an important part of the reaction coordinate.

Jaume, J.; Lluch, J. M.; Oliva, A.; Bertrán, J.

1984-04-01

38

Importance Driven Texture Coordinate Optimization  

Microsoft Academic Search

Traditionally, texture coordinates have been generated based solely on the model's geometry, often even before a model's textures have been created. With the arrival of new technologies, such as 3D paint programs, weaknesses of a static optimization pre-process are becoming apparent. These weaknesses arise from constructing a parame- terization based solely on the model's geometry, ignoring the fact that detail

Peter-pike J. Sloan; David M. Weinstein; J. Dean Brederson

1998-01-01

39

coordinate plane  

NSDL National Science Digital Library

Become familiar with the coordinate plane. Learn the quadrants and how to graph points and read points on a coordinate plane. You are required to do the assignment and take the quiz. The other resources are to help prepare you for the quiz and book assignment. This is a quick review of the lesson.The Coordinate Plane This is a game to practice plotting and reading points.coordinates game *Assignment: Watch Powerpoint 3.3 and fill in your ...

Olsen

2010-10-07

40

Academic Coordination.  

ERIC Educational Resources Information Center

|Coordination of higher education within national sets is discussed in this working paper. The structural bases of national coordination, the tasks of higher education and the prevailing structure of embedded power, are described. The national general patterns of coordinative organization that appear frequently among national systems of higher…

Clark, Burton R.

41

Hydrogen Bond-Directed Hexagonal Frameworks Based on Coordinated 1,3,5-Benzenetricarboxylate  

NASA Astrophysics Data System (ADS)

We report two phases containing the hexagonal (6,3) network of the graphene sheet derived by tridentate coordination of 1,3,5-benzenetricarboxylate to octahedral NiII centers. When the solvent used is 2-methyl-1-butanol, water directs the coordination about NiII and ABCA'B'C' stacking of layers is obtained. The use of 1-butanol as solvent gives a different hydrogen-bonding arrangement around NiII and produces AAA stacking of the layers. We have previously demonstrated that the use of other alcohols such as methanol, ethanol, 1,2-ethanediol, and 1,2-propanediol leads to the formation of 3-D architectures. Here we show that a change in the hydrogen bonding around the metal center leads to 2-D structures which house substantial solvent-filled microcavities. The comparatively weak interactions between layers, and the relative importance of framework-solvent interactions, facilitates slippage of the hexagonal sheets and interconversion between stacking type with guest exchange.

Kepert, C. J.; Prior, T. J.; Rosseinsky, M. J.

2000-06-01

42

Dynamics of the Formation of a Charge Transfer State in 1,2-Bis(9-anthryl)acetylene in Polar Solvents: Symmetry Reduction with the Participation of an Intramolecular Torsional Coordinate.  

PubMed

We have studied 1,2-bis(9-anthryl)acetylene as a model compound for the characterization of the process of solvent-mediated symmetry reduction in an excited state. Thanks to the acetylenic bridge that joins the two anthracenic moieties, this system maintains minimal steric hindrance between the end chromophores in comparison with the classic 9,9'-bianthryl model compound. The acetylenic bridge also allows for significant electronic coupling across the molecule, which permits a redistribution of electron density after light absorption. Femtosecond resolved fluorescence measurements were used to determine the spectral evolution in acetonitrile and cyclohexane solutions. We observed that, for 1,2-bis(9-anthryl)acetylene, the formation of a charge transfer state occurs in a clear bimodal fashion with well separated time scales. Specifically, the evolution of the emission spectrum involves a first solvent-response mediated subpicosecond stage where the fluorescence changes from that typical of nonpolar solvents (locally excited) to an intermediate, partial charge transfer state. The second stage of the evolution into a full charge transfer state occurs with a much longer time constant of 37.3 ps. Since in this system the steric hindrance is minimized, this molecule can undergo much larger amplitude motions for the torsion between the two anthracenic moieties associated with the charge redistribution in comparison with the typical model compound 9,9'-bianthryl. Clearly, the larger range of motions of 1,2-bis(9-anthryl)acetylene gives the opportunity to study the electron transfer process with a good separation of the time scales for the formation of a partial charge transfer state, determined by the speed of solvent response, and the intramolecular changes associated with the formation of the fully equilibrated charge transfer state. PMID:24016357

Gutiérrez-Arzaluz, Luis; Guarin, Cesar A; Rodríguez-Córdoba, William; Peon, Jorge

2013-09-27

43

Weakly ??-continuous functions  

NASA Astrophysics Data System (ADS)

In this paper we introduce a new class of generalizations of continuous functions via ??-open sets called weakly ??-continuous functions. Moreover, we study some of its fundamental properties and characterizations. The concept of weak ??-continuous is weaker than ??-continuous, weakly ?-continuous and weakly ?-continuous functions, are also discussed.

Aljarrah, Heyam Hussein; Md Noorani, Mohd Salmi

2013-09-01

44

Concatenate Coordination and Mutual Coordination  

Microsoft Academic Search

We tell of the evolving meaning of the term coordination as used by economists. The paper is based on systematic electronic searches (on “coord,” etc.) of major works and leading journals. The term coordination first emerged in professional economics around 1880, to describe the directed productive concatenation of factors or activities within a firm. Also, transportation economists used the term

Daniel B. Klein; Aaron Orsborn

2008-01-01

45

Astronomical Coordinates  

NSDL National Science Digital Library

The celestial coordinate system is a projection of earth's coordinate system into the celestial sphere. Being just like Earth's system it contains an "equator", lines of "latitude" and "longitude", and even poles. (Though we don't use the same words for it.) One suggestion one might have would be to just extend the Earth's latitude, longitude, and equator out into the night sky, but the Earth is constantly spinning. For the Celestial coordinates, we have to pick some fixed reference to go by.

Joiner, David; The Shodor Education Foundation, Inc.

46

Solvent effect on the optical property of uranyl acetylacetonate monohydrate  

NASA Astrophysics Data System (ADS)

The lability of the [UO 2(acac) 2H 2O] complex has been exploited to decipher solvent composition of a medium. Successive blue shift of the ?-?* band ( ?max = 282 nm) is observed due to alcohol substitution of increasing chain length in place of water. This observation helps to quantify the chain lengths of normal alcohol. The result has been accounted theoretically. However, in non-coordinating solvent, irregular red shift of the ?-?* band is observed because of the molecular complexity. Again, charge transfer (CT) band at 211 nm has been identified employing polar-polar and polar coordinating-non-coordinating solvent systems.

Pradhan, Mukul; Basu, Mrinmoyee; Sarkar, Sougata; Sinha, Arun Kumar; Pal, Tarasankar

2011-01-01

47

A computational study of ultrafast acid dissociation and acid-base neutralization reactions. II. The relationship between the coordination state of solvent molecules and concerted versus sequential acid dissociation  

NASA Astrophysics Data System (ADS)

We investigate the role played by the coordination state of pre-existing water wires during the dissociation of moderately strong acids by means of first-principles molecular dynamics calculations. By preparing 2,4,6-tricyanophenol (calc. pKa~0.5) in two different initial states, we are able to observe sequential as well as concerted trajectories of dissociation: On one hand, equilibrium dissociation takes place on a ~50 ps timescale; proton conduction occurs through three-coordinated water wires in this case, by means of sequential Grotthus hopping. On the other hand, by preparing 2,4,6-tricyanophenol in a hydration state inherited from that of equilibrated phenol (calc. pKa = 7.6), the moderately strong acid finds itself in a presolvated state from which dissociation can take place on a ~1 ps timescale. In this case, concerted dissociation trajectories are observed, which consist of proton translocation through two intervening, four-coordinated, water molecules in 0.1-1.0 ps. The present results suggest that, in general, the mechanism of proton translocation depends on how the excess proton is injected into a hydrogen bond network. In particular, if the initial conditions favour proton release to a fourfold H-bonded water molecule, proton translocation by as much as 6-8 A? can take place on a sub-picosecond timescale.

Maurer, Patrick; Thomas, Vibin; Iftimie, Radu

2011-03-01

48

Coordination et qualité dans les filières agricoles du Sud  

Microsoft Academic Search

The objective of the project is to assess the strengths and weaknesses of different forms of coordination in the development of quality chains in developing countries. Such forms of coordination include: signs of quality (labels, brands, geographical references); horizontal coordination (producers' or traders' associations); vertical coordination (personalized relationships, contracts, integration). Our project is attempting to: (i) characterize problems with quality;

P. Moustier; J. Egg; F. Tallec

2006-01-01

49

Solvent-induced symmetry breaking: Varying solvent strength  

NASA Astrophysics Data System (ADS)

The triiodide ion is an example of a system where symmetry breaking may be induced by a solvent. The Landau free energy is expected to have a similar form to that for the mean field Ising model, but with solvent strength rather than temperature as the control parameter determining whether there is symmetry breaking. In order to examine the extent of anomalous behavior near the critical point we have studied the properties of the ion in a solvent based on a model for water with charges scaled by a factor ? . As ? is increased from zero the solvent strength increases and the system changes from one with no symmetry breaking to one with strong symmetry breaking. The Shannon entropy as a function of ? shows only a weak maximum near the critical value of ?=?c , while the susceptibility has no anomalous behavior. We examine a simple model and show that anomalies near the critical point would increase as the temperature decreases, but divergences associated with a second order phase transition would only be seen in the limit of zero temperature.

Zhang, F. S.; Lynden-Bell, R. M.

2005-02-01

50

Solvent-induced symmetry breaking: varying solvent strength.  

PubMed

The triiodide ion is an example of a system where symmetry breaking may be induced by a solvent. The Landau free energy is expected to have a similar form to that for the mean field Ising model, but with solvent strength rather than temperature as the control parameter determining whether there is symmetry breaking. In order to examine the extent of anomalous behavior near the critical point we have studied the properties of the ion in a solvent based on a model for water with charges scaled by a factor lambda . As lambda is increased from zero the solvent strength increases and the system changes from one with no symmetry breaking to one with strong symmetry breaking. The Shannon entropy as a function of lambda shows only a weak maximum near the critical value of lambda= lambda(c) , while the susceptibility has no anomalous behavior. We examine a simple model and show that anomalies near the critical point would increase as the temperature decreases, but divergences associated with a second order phase transition would only be seen in the limit of zero temperature. PMID:15783328

Zhang, F S; Lynden-Bell, R M

2005-02-23

51

Weak scale supersymmetry  

SciTech Connect

An introduction to the ideas and current state of weak scale supersymmetry is given. It is shown that LEP data on Z decays has already excluded two of the most elegant models of weak scale supersymmetry. 14 refs.

Hall, L.J. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Physics)

1990-11-12

52

Weak scale supersymmetry.  

National Technical Information Service (NTIS)

An introduction to the ideas and current state of weak scale supersymmetry is given. It is shown that LEP data on Z decays has already excluded two of the most elegant models of weak scale supersymmetry. 14 refs.

L. J. Hall

1990-01-01

53

Diaphragmatic weakness and paralysis  

Microsoft Academic Search

Diaphragmatic weakness implies a decrease in the strength of the diaphragm. Diaphragmatic paralysis is an extreme form of\\u000a diaphragmatic weakness. Diaphragmatic paralysis is an uncommon clinical problem while diaphragmatic weakness, although uncommon,\\u000a is probably frequently unrecognized because appropriate tests to detect its presence are not performed. Weakness of the diaphragm\\u000a can result from abnormalities at any site along its neuromuscular

Pearce G. Wilcox; Richard L. Pardy

1989-01-01

54

Solvent wash solution  

DOEpatents

A process is claimed for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 vol % of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

Neace, J.C.

1984-03-13

55

Parsing Coordinations  

Microsoft Academic Search

The present paper is concerned with sta- tistical parsing of constituent structures in German. The paper presents four ex- periments that aim at improving parsing performance of coordinate structure: 1) reranking the n-best parses of a PCFG parser, 2) enriching the input to a PCFG parser by gold scopes for any conjunct, 3) reranking the parser output for all possi-

Sandra Kübler; Erhard W. Hinrichs; Wolfgang Maier; Eva Klett

2009-01-01

56

Magnetosheath Coordinates  

Microsoft Academic Search

The eventual goal of this work is to develop an approximate analytical representation of solar-wind streamlines in the magnetosheath surrounding a magnetosphere of rather general shape. Previous analytical representations of magnetosheath streamlines and magnetic fields have invoked magnetopause shapes that conform to standard coordinate systems (e.g., spherical, cylindrical, paraboloidal, ellipsoidal), but it seems now that such a restriction on magnetopause

M. Schulz; M. W. Chen

2010-01-01

57

Weak-scintillation light yield determination  

SciTech Connect

The pulse-height distribution produced by weak scintillations is simulated as a Poisson distribution if the mean number of photoelectrons collected at the first dynode is of the order of one. This method enables one to determine the scintillation yield also when the photomultiplier does not show a peak in the single-electron pulses. Scintillation yields have been determined for some aqueous solutions of sodium salicylate and for aromatic solvents (benzene, toluene, and xylene) on internal irradiation by ..cap alpha.. particles.

Mandzhukov, I.G.; Mandzhukova, B.V.

1987-12-01

58

COORDINATORS: Coordination Managers for First Responders  

Microsoft Academic Search

COORDINATORs are coordination managers for fielded first responders. Each first response team is paired with a COORDINATOR coordination manager which is running on a mobile computing device. COORDINATORs provide decision support to first response teams by reasoning about who should be doing what, when, with what resource, in support of which other team, and so forth. COORDINATORs respond to the

Thomas Wagner; John Phelps; Valerie Guralnik; Ryan VanRiper

2004-01-01

59

Solvent recovery targeting  

SciTech Connect

One of the environmental challenges faced by the pharmaceutical and specialty chemical industries is the widespread use of organic solvents. With a solvent-based chemistry, the solvent necessarily has to be separated from the product. Chemical species in waste-solvent streams typically form multicomponent azeotropic mixtures, and this often complicates separation and, hence, recovery of solvents. A design approach is presented whereby process modifications proposed by the engineer to reduce the formation of waste-solvent streams can be evaluated systematically. This approach, called solvent recovery targeting, exploits a recently developed algorithm for elucidating the separation alternatives achievable when applying batch distillation to homogeneous multicomponent mixtures. The approach places the composition of the waste-solvent mixture correctly in the relevant residue curve map and computes the maximum amount of pure material that can be recovered via batch distillation. Solvent recovery targeting is applied to two case studies derived from real industrial processes.

Ahmad, B.S.; Barton, P.I. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1999-02-01

60

An unusual double T5(2) water tape trapped in silver(I) coordination polymer hosts: influence of the solvent on the assembly of Ag(I)-4,4'-bipyridine chains with trans-cyclohexanedicarboxylate and their luminescent properties.  

PubMed

In this paper, four silver(I) compounds, namely, {[Ag(4)(bipy)(4)(chda)]·2NO(3)·10H(2)O}(n) (1), {[Ag(2)(bipy)(2)(chda)]·14H(2)O}(n) (2), {[Ag(2)(bipy)(2)(chda)]·3EG·2H(2)O}(n) (3) and {[Ag(2)(bipy)(2)(chda)]·H(2)chda}(n) (4) (where bipy = 4,4'-bipyridine, H(2)chda = trans-cyclohexane-dicarboxylate and EG = ethylene glycol), have been synthesized and characterized by single-crystal X-ray diffraction analyses. In all of these compounds, the Ag(I) centers are linked by bipy ligands to form 1D Ag(I)-bipy chain structures. The chda(2-) anions of compound 1 adopt a ?(4)-coordination mode to connect the Ag(I)-bipy chains, forming a H-beam-like chain. In 2, the chda(2-) anions adopt a ?(2)-coordination mode to connect the Ag(I)-bipy chains resulting in two distinct 2D brick wall-like layers. These layers are further stacked in an ···ABAB··· fashion through interlayer ?···? stacking interactions giving rise to a 3D framework consisting of quasi-rectangular channels, in which an unusual double T5(2) water tape is trapped. For 3 and 4, the chda(2-) anions show a similar ?(4)-coordination mode to that of 1 and connect the Ag(I)-bipy chains to form 2D grid layers with identical compositions and connective topologies. The experimental studies show that the final structures are greatly influenced by the molar ratio of the components and the solvents, which can be rationally interpreted by the existence of various supramolecular interactions between the host and guest molecules within these compounds through a systematic structural comparison. Additionally, the thermal stability and luminescent properties of these compounds were also studied. PMID:22986411

Li, Ting; Huang, Xi-He; Zhao, Ya-Feng; Li, Hao-Hong; Wu, Shu-Ting; Huang, Chang-Cang

2012-11-01

61

Nonclassicality in weak measurements  

SciTech Connect

We examine weak measurements of arbitrary observables where the object is prepared in a mixed state and on which measurements with imperfect detectors are made. The weak value of an observable can be expressed as a conditional expectation value over an infinite class of different generalized Kirkwood quasiprobability distributions. 'Strange' weak values for which the real part exceeds the eigenvalue spectrum of the observable can only be found if the Terletsky-Margenau-Hill distribution is negative or, equivalently, if the real part of the weak value of the density operator is negative. We find that a classical model of a weak measurement exists whenever the Terletsky-Margenau-Hill representation of the observable equals the classical representation of the observable and the Terletsky-Margenau-Hill distribution is non-negative. Strange weak values alone are not sufficient to obtain a contradiction with classical models. We propose feasible weak measurements of photon number of the radiation field. Negative weak values of energy contradict all classical stochastic models, whereas negative weak values of photon number contradict all classical stochastic models where the energy is bounded from below by the zero-point energy. We examine coherent states in particular and find negative weak values with probabilities of 16% for kinetic energy (or squared field quadrature), 8% for harmonic oscillator energy, and 50% for photon number. These experiments are robust against detector inefficiency and thermal noise.

Johansen, Lars M. [Department of Technology, Buskerud University College, N-3601 Kongsberg (Norway); Luis, Alfredo [Departamento de Optica, Facultad de Ciencias Fisicas, Universidad Complutense, 28040 Madrid (Spain)

2004-11-01

62

Coordinate Plane  

NSDL National Science Digital Library

5th Grade Math State core Standard 3, Objective 2a: Locate points defined by ordered pairs of integers. Congratulations for earning a game day in the computer lab! Remember that even though it is game day I expect you to stay on task and follow directions. We have been talking in math about graphing integers on the coordinate plane. The games for today require that ...

Zilles, Miss

2007-10-31

63

Superconducting weak links  

Microsoft Academic Search

This review covers experimental results and theoretical ideas on the properties of superconducting weak links, i.e., weak electrical contacts between superconducting electrodes which exhibit direct (non-tunnel-type) conductivity. When the dimensions of such weak links are sufficiently small, the Josephson effect is observed in them, in other words, a single-valued and 2pi -periodic relationship exists between the supercurrent Is and the

K. K. Likharev

1979-01-01

64

Weak gravitational lensing  

Microsoft Academic Search

We review theory and applications of weak gravitational lensing. After summarising Friedmann–Lema??tre cosmological models, we present the formalism of gravitational lensing and light propagation in arbitrary space–times. We discuss how weak-lensing effects can be measured. The formalism is then applied to reconstructions of galaxy-cluster mass distributions, gravitational lensing by large-scale matter distributions, QSO–galaxy correlations induced by weak lensing, lensing of

Matthias Bartelmann; Peter Schneider

2001-01-01

65

Working with Industrial Solvents.  

National Technical Information Service (NTIS)

A pamphlet provides information on the occupational safety aspects of work with solvents. Topics include uses of solvents, definition, health problems associated with use, exposure control, management responsibilities, and workers' responsibilities. All o...

1972-01-01

66

Dynamic solvent effects on the thermal isomerization of zinc dithizonate.  

PubMed

The pressure dependence of the rate constant for the thermal isomerization of zinc dithizonate was measured at various temperatures in highly viscous solvents, i.e., glycerol triacetate and 2,4-dicyclohexyl-2-methylpentane, as well as in their chemically similar nonviscous solvents, such as methyl acetate and methylcyclohexane. In the nonviscous solvents, the reaction was slightly retarded upon external pressure suggesting the validity of the transition state theory. On the other hand, in the viscous solvents, the reaction, even at ambient pressure, was strongly retarded by an increase in external pressure suggesting the slow thermal fluctuation of the solvent molecules upon external pressure in highly viscous systems. This made it possible to observe the dynamic solvent effects on the isomerization of zinc dithizonate in viscous solvents. The viscosity dependence of the rate constants was rationalized by the two-dimensional reaction coordinate model. PMID:19562150

Gulam, Rabbani M; Takahashi, Toru; Ohga, Yasushi

2009-04-06

67

Perturbation Hamiltonians in heterogeneous anisotropic weakly dissipative media  

Microsoft Academic Search

Perturbation Hamiltonians simplify considerably the solution of various traveltime perturbation problems of seismic body waves propagating in heterogeneous, isotropic or anisotropic, weakly dissipative media. In addition to the phase-space coordinates, representing the Cartesian coordinates and Cartesian components of the slowness vector, the perturbation Hamiltonians also depend on one or more dimensionless perturbation parameters, which can be chosen in different ways.

Vlastislav Cervený; Ivan Psencík

2009-01-01

68

Solvent dehydration system  

SciTech Connect

Improvements are described in processes for stripping solvent from dewaxed oils and deoiled waxes; such as the use of an inert gas (such as nitrogen) as a stripping agent for removing solvent from dewaxed oils, deoiled waxes and slack waxes resultant from solvent dewaxing processes.

Button, H.O.; McCall, T.F.; Meyer, D.W.

1980-04-22

69

Robust Weak Measurements  

NASA Astrophysics Data System (ADS)

We introduce a new type of weak measurement which yields a quantum average of weak values that is robust, outside the range of eigenvalues, extends the valid regime for weak measurements, and for which the probability of obtaining the pre- and post-selected ensemble is not exponentially rare. This result extends the applicability of weak values, shifts the statistical interpretation previously attributed to weak values and suggests that the weak value is a property of every pre- and post-selected ensemble. We then apply this new weak measurement to Hardy's paradox. Usually the paradox is dismissed on grounds of counterfactuality, i.e., because the paradoxical effects appear only when one considers results of experiments which do not actually take place. We suggest a new set of measurements in connection with Hardy's scheme, and show that when they are actually performed, they yield strange and surprising outcomes. More generally, we claim that counterfactual paradoxes point to a deeper structure inherent to quantum mechanics characterized by weak values (Aharonov Y, Botero A, Popescu S, Reznik B, Tollaksen J, Physics Letters A, 301 (3-4): 130-138, 2002).

Tollaksen, Jeff; Aharonov, Yakir

2006-03-01

70

Idiopathic isolated orbicularis weakness  

PubMed Central

Purpose Orbicularis weakness is commonly associated with seventh nerve palsy or neuromuscular and myopathic conditions such as myotonic dystrophy and myasethenia gravis. We report four cases of idiopathic isolated orbicularis weakness. Methods All four cases were female and the presenting symptoms of ocular irritation and epiphora had been present for over 7 years in three patients. All patients had lagophthalmos and three had ectropion. Three patients underwent full investigations which excluded known causes of orbicularis weakness. Two patients underwent oribularis oculi muscle biopsy and histological confirmation of orbicularis atrophy. Results All patients underwent surgery to specifically address the orbicularis weakness with satisfactory outcomes and alleviation of symptoms in all cases. Isolated orbicularis weakness may be a relatively common entity that is frequently overlooked. Conclusion Early recognition of this condition may lead to better management and prevent patients undergoing unnecessary surgical procedures.

MacVie, O P; Majid, M A; Husssin, H M; Ung, T; Manners, R M; Ormerod, I; Pawade, J; Harrad, R A

2012-01-01

71

Effect of solvents and catalysts on monolithicity and physical properties of silica aerogels  

Microsoft Academic Search

The effect of various solvents and catalysts on the monolithicity and physical properties of silica aerogels is reported. The aerogels were prepared by hydrolysis and polycondensation of tetramethoxysilane, followed by hypercritical drying, using 6 solvents of different chain lengths, and 17 catalysts consisting of strong and weak acids, bases and their mixtures. It was found that solvents of longer chain

A. Venkateswara Rao; G. M. Pajonk; N. N. Parvathy

1994-01-01

72

Chemical reaction rates and solvent friction  

SciTech Connect

The role of the dynamic solvent friction in influencing the rates of chemical reactions in solution is described. Features considered include (a) the bias of the reaction coordinate toward a direction of lesser friction in the diffusive limit, (b) the importance of frequency-dependent friction in atom transfers, tunneling reactions and isomerizations, (c) the dynamic nonequilibrium solvation in charge transfers which leads to a polar solvent molecule reorientation time dependence for the rate, and (d) the importance of internal degrees of freedom in the location of the Kramers turnover for isomerizations.

Hynes, J.T.

1986-01-01

73

Strange weak values  

NASA Astrophysics Data System (ADS)

We develop a formal theory of the weak values with emphasis on the consistency conditions and a probabilistic interpretation in the counter-factual processes. We present the condition for the choice of the post-selected state to give a negative weak value of a given projection operator and strange values of an observable in general. The general framework is applied to Hardy's paradox and the spin-1/2 system to explicitly address the issues of counter-factuality and strange weak values. The counter-factual arguments which characterize the paradox specify the pre-selected state, and a complete set of the post-selected states clarifies how the strange weak values emerge.

Hosoya, Akio; Shikano, Yutaka

2010-09-01

74

? weak magnetic dipole moment  

Microsoft Academic Search

The weak magnetic dipole moment of the ?-lepton is reviewed. Standard Model predictions and the last experimental results are presented. These may result in a stringent test for both their point-like structure and also for new physics.

Gabriel Gonza´lez-Sprinberg

1998-01-01

75

Halogenated solvent remediation  

Microsoft Academic Search

Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding an electron donor for microbe-mediated anaerobic reductive dehalogenation of the halogenated solvents, which electron donor enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative electron donors include C.sub.2-C.sub.4 carboxylic acids

Kent S

2008-01-01

76

Organic solvent topical report  

Microsoft Academic Search

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will

1999-01-01

77

Coordination steric effect of N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone on the assembly of coordination polymers  

Microsoft Academic Search

Three coordination polymers 1, 2 and 3 have been synthesized in DMF (N,N-dimethylformamide), DMA (N,N-dimethylacetamide) and NMP (N-methyl-2-pyrrolidone), respectively. In 1, DMF solvent molecule coordinates to zinc ion as an ancillary ligand, and 1D chain structure is obtained. 2 and 3 are isostructural, in which solvent molecules, DMA and NMP, do not coordinate to zinc ions, and 1D double stranded

Hui-Min Li; Shi-Yao Yang; Jian-Wei Wang; La-Sheng Long; Rong-Bing Huang; Lan-Sun Zheng

2010-01-01

78

Weak bump quasars  

NASA Astrophysics Data System (ADS)

Research into the optical, ultraviolet and infrared continuum emission from quasars and their host galaxies was carried out. The main results were the discovery of quasars with unusually weak infrared emission and the construction of a quantitative estimate of the dispersion in quasar continuum properties. One of the major uncertainties in the measurement of quasar continuum strength is the contribution to the continuum of the quasar host galaxy as a function of wavelength. Continuum templates were constructed for different types of host galaxy and individual estimates made of the decomposed quasar and host continua based on existing observations of the target quasars. The results are that host galaxy contamination is worse than previously suspected, and some apparent weak bump quasars are really normal quasars with strong host galaxies. However, the existence of true weak bump quasars such as PHL 909 was confirmed. The study of the link between the bump strength and other wavebands was continued by comparing with IRAS data. There is evidence that excess far infrared radiation is correlated with weaker ultraviolet bumps. This argues against an orientation effect and implies a probable link with the host galaxy environment, for instance the presence of a luminous starburst. However, the evidence still favors the idea that reddening is not important in those objects with ultraviolet weak bumps. The same work has led to the discovery of a class of infrared weak quasars. Pushing another part of the envelope of quasar continuum parameter space, the IR-weak quasars have implications for understanding the effects of reddening internal to the quasars, the reality of ultraviolet turnovers, and may allow further tests of the Phinney dust model for the IR continuum. They will also be important objects for studying the claimed IR to x-ray continuum correlation.

Wilkes, B. J.; McDowell, J.

1994-01-01

79

Weak-field limit  

NASA Astrophysics Data System (ADS)

Astrophysical applications of ETGs include the possibility of replacing dark matter in galaxy and clusters with modifications of gravity, the weak-field (Newtonian and post-Newtonian) limit, and gravitational waves. Dark matter at galactic and cluster scales is traditionally included in the realm of cosmology and is discussed in Chap. 7. Here we focus on the weak-field limit of metric f(R) gravity, referring the reader to well known sources for other ETGs. We then discuss gravitational waves in ETGs.

Capozziello, Salvatore; Faraoni, Valerio

80

Weak radiative hyperon decays  

NASA Astrophysics Data System (ADS)

The problem of weak radiative hyperon decays (WRHD) is reviewed. With the rcent measurement of the ?0 -> ?? asymmetry confirming Hara's theorem, implications from its violation in low-energy theoretical approaches are discussed. It is shown how an underlying symmetry link should be formulated for a successful description of both nonleptonic and radiative weak hyperon decays. The sign of the ?0 -> ?? asymmetry and the overall size of parity-violating WRHD amplitudes together lead to the resolution of the old S:P problem in nonleptonic decays.

?enczykowski, P.

2003-02-01

81

ONSITE SOLVENT RECOVERY  

EPA Science Inventory

This study evaluated the product quality, waste reduction/pollution prevention, and economic aspects of three technologies for onsite solvent recovery: atmospheric batch distillation, vacuum heat-pump distillation, and a low-emission vapor degreaser with closed solvent, liquid an...

82

Weak Radial Artery Pulse  

PubMed Central

We present an 11year-old boy with a weak right radial pulse, and describe the successful application of vascular ultrasound to identify the ulnar artery dominance and a thin right radial artery with below normal Doppler flow velocity that could explain the discrepancy. The implications of identifying this anomaly are discussed.

Venugopalan, Poothirikovil; Sivakumar, Puthuval; Ardley, Robert G.; Oates, Crispian

2012-01-01

83

Weak decays at PEP  

SciTech Connect

Results are presented on four aspects of weak decays. The MARK II measurement of the tau lifetime, the MARK II measurement of the D/sup 0/ lifetime, the measurement from several experiments of the semi-leptonic branching fractions of hadrons constraining b and c quarks, and lastly the MAC measurement of the B lifetime. 30 references.

Yelton, J.M.

1984-04-01

84

SOLVENT EXTRACTION PROCESS  

DOEpatents

In improved solvent extraction process is described for the extraction of metal values from highly dilute aqueous solutions. The process comprises contacting an aqueous solution with an organic substantially water-immiscible solvent, whereby metal values are taken up by a solvent extract phase; scrubbing the solvent extract phase with an aqueous scrubbing solution; separating an aqueous solution from the scrubbed solvent extract phase; and contacting the scrubbed solvent phase with an aqueous medium whereby the extracted metal values are removed from the solvent phase and taken up by said medium to form a strip solution containing said metal values, the aqueous scrubbing solution being a mixture of strip solution and an aqueous solution which contains mineral acids anions and is free of the metal values. The process is particularly effective for purifying uranium, where one starts with impure aqueous uranyl nitrate, extracts with tributyl phosphate dissolved in carbon tetrachloride, scrubs with aqueous nitric acid and employs water to strip the uranium from the scrubbed organic phase.

Jonke, A.A.

1957-10-01

85

Hysteresis in weak ferromagnets  

NASA Astrophysics Data System (ADS)

Magnetic hysteresis is studied in the orthoferrites ErFeO3 and TmFeO3 using the single crystal samples of millimeter dimensions. It is shown that in both materials one observes a temperature transition manifesting itself through the temperature hysteresis of the magnetic moment and a peculiar temperature evolution of the field hysteresis loop shapes near this transition. Experiments rule out the hypothesis that the ordering of the orthoferrite's rare earth magnetic moments plays an important role in these phenomena. The hysteresis curves can be explained by a few-domain magnetic state of the samples that results from the weak ferromagnetism of the orthoferrites. The phenomenon is generic for weak ferromagnets with temperature dependent magnetization. A large characteristic magnetic length makes the behavior of the relatively big samples analogous to that observed in the nano-size samples of strong ferromagnets.

Bazaliy, Ya. B.; Tsymbal, L. T.; Kakazei, G. N.; Vasiliev, S. V.

2011-03-01

86

Weak massive gravity  

NASA Astrophysics Data System (ADS)

We find a new class of theories of massive gravity with five propagating degrees of freedom where only rotations are preserved. Our results are based on a nonperturbative and background-independent Hamiltonian analysis. In these theories the weak field approximation is well behaved and the static gravitational potential is typically screened à la Yukawa at large distances, while at short distances no van Dam-Veltman-Zakharov discontinuity is found and there is no need to rely on nonlinear effects to pass the solar system tests. The effective field theory analysis shows that the ultraviolet cutoff is (mMPl)1/2?1/?m, the highest possible. Thus, these theories can be studied in the weak-field regime at all the phenomenologically interesting scales and are candidates for a calculable large-distance modified gravity.

Comelli, D.; Nesti, F.; Pilo, L.

2013-06-01

87

Developmental coordination disorder  

MedlinePLUS

Developmental coordination disorder is a childhood disorder that leads to poor coordination and clumsiness. ... of school-age children have some kind of developmental coordination disorder. Children with this disorder may: Have ...

88

Composite weak bosons  

SciTech Connect

Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.

Suzuki, M.

1988-04-01

89

Weak characteristics of muonium  

SciTech Connect

The allowed weak decay channels of muonium are studied in detail. They acquire additional significance in the context of possible {ital M}-{ital {bar M}} oscillations that probe beyond the standard model. The muonium decay rate and annihilation rate are found to be 1.000 023 and 1.045{times}10{sup {minus}10}, respectively, in units of the free muon decay rate.

Chatterjee, L.; Chakrabarty, A.; Das, G.; Mondal, S. (Physics Department, Jadavpur University, Calcutta 32 (India))

1992-12-01

90

Comparison of Partition Chromatographic Parameters of Lipophilic Organic Electrolytes for Solvents of Various Donor-Acceptor Properties. V. Phenols in Systems of the Type Organic Solvent\\/Formamide  

Microsoft Academic Search

RM values of a number of phenols (cresols, xylenols, chlorophenols, hydroxynaphthalenes) have been determined for numerous solvent systems of the type, weakly polar solvent\\/formamide. To determine a quantitative scale of extraction strengths, RM-solvent spectra have been plotted using a modified method of Rohrschneider and Littlewood. 2-Methylquinoline, used in previous investigations as a reference solute for nitrogen bases, has been found

Edward Soczewi?ki; Wies?awa Maciejewicz

1970-01-01

91

Epidemiology of organic solvents and connective tissue disease  

PubMed Central

Case reports suggest that solvents are associated with various connective tissue diseases (systemic sclerosis, scleroderma, undifferentiated connective tissue disease, systemic lupus erythematosis, and rheumatoid arthritis), particularly systemic sclerosis. A small number of epidemiological studies have shown statistically significant but weak associations between solvent exposure, systemic sclerosis, and undifferentiated connective tissue disease. However, the interpretation of these positive findings is tempered by a lack of replication, an inability to specify which solvents convey risk, and an absence of increasing risk with increasing exposure. Existing studies, on aggregate, do not show conclusively that solvents (either as a group of chemicals or individual chemicals) are causally associated with any connective tissue disease. Further investigations should be carried out to replicate the positive existing findings and to specify the solvents and circumstances of exposure that carry risk.

Garabrant, David H; Dumas, Constantine

2000-01-01

92

Dendritic brushes under theta and poor solvent conditions  

NASA Astrophysics Data System (ADS)

The effects of solvent quality on the internal stratification of polymer brushes formed by dendron polymers up to third generation were studied by means of molecular dynamics simulations with Langevin thermostat. The distributions of polymer units, of the free ends, the radii of gyration, and the back folding probabilities of the dendritic spacers were studied at the macroscopic states of theta and poor solvent. For high grafting densities we observed a small decrease in the height of the brush as the solvent quality decreases. The internal stratification in theta solvent was similar to the one we found in good solvent, with two and in some cases three kinds of populations containing short dendrons with weakly extended spacers, intermediate-height dendrons, and tall dendrons with highly stretched spacers. The differences increase as the grafting density decreases and single dendron populations were evident in theta and poor solvent. In poor solvent at low grafting densities, solvent micelles, polymeric pinned lamellae, spherical and single chain collapsed micelles were observed. The scaling dependence of the height of the dendritic brush at high density brushes for both solvents was found to be in agreement with existing analytical results.

Gergidis, Leonidas N.; Kalogirou, Andreas; Charalambopoulos, Antonios; Vlahos, Costas

2013-07-01

93

Gravitational anomaly and Hawking radiation near a weakly isolated horizon  

NASA Astrophysics Data System (ADS)

Based on the idea of the work by Wilczek and his collaborators, we consider the gravitational anomaly near a weakly isolated horizon. We find that there exists a universal choice of tortoise coordinate for any weakly isolated horizon. Under this coordinate, the leading behavior of a quite arbitrary scalar field near a horizon is a 2-dimensional chiral scalar field. This means we can extend the idea of Wilczek and his collaborators to more general cases and show the relation between gravitational anomaly and Hawking radiation is a universal property of a black hole horizon.

Wu, Xiaoning; Huang, Chao-Guang; Sun, Jia-Rui

2008-06-01

94

Nonholonomic passive decomposition: Weak decomposability, controllability and control design  

Microsoft Academic Search

We extend the results of to general non-holonomic mechanical systems with weak decomposability (as opposed to strong decomposability). That is, for a nonholonomic mechanical system (or for multiple of them) with weak decomposability, given a submersion h defined on their configuration space and specifying a certain motion coordination aspect (e.g. internal formation shape), we can decompose their Lagrange-D'Alembert dynamics into:

Dongjun Lee

2010-01-01

95

Onsite Solvent Recovery.  

National Technical Information Service (NTIS)

This study evaluated the product quality, waste reduction/pollution prevention, and economic aspects of three technologies for onsite solvent recovery. The technologies were (1) atmospheric batch distillation, (2) vacuum heat-pump distillation, and (3) lo...

A. R. Gavaskar R. F. Olfenbuttel L. A. Hernon-Kenny J. A. Jones M. A. Salem J. R. Becker J. E. Tabor

1993-01-01

96

Managing solvent wastes  

SciTech Connect

There are economic and regulatory incentives for considering alternatives to the direct land disposal of solvent-bearing hazardous waste streams (EPA Hazardous Waste Codes: F001, F002, F003, F004, and F005). These alternatives include recycle/reuse (including use as a fuel substitute), destruction of a stream's solvent component, and treatment prior to land disposal. This paper reviews these three waste management alternatives and discusses their applicability to solvent waste streams having various physical characteristics. Seven waste treatment techniques which may be used to handle solvent wastes are described: incineration, agitated thin-film evaporation, fractional distillation, steam stripping, wet oxidation, carbon adsorption, and activated sludge biological treatment.3 tables.

Blaney, B.L.

1986-03-01

97

How Does the Solvent Control Electron Transfer? Experimental and Theoretical Studies of the Simplest Charge Transfer Reaction  

Microsoft Academic Search

The standard theoretical description used to describe electron transfer is Marcus theory, which maps the polarization of the solvent surrounding the reactants onto a reaction coordinate, q. The questions we address in this paper are: How many and what types of solvent degrees of freedom constitute q? Is it appropriate to treat the solvent as a dielectric continuum? Our approach

Erik R. Barthel; Ignacio B. Martini; Benjamin J. Schwartz

2001-01-01

98

Cleaning without chlorinated solvents  

SciTech Connect

Because of health and environmental concerns, many regulations have been passed in recent years regarding the use of chlorinated solvents. The Oak Ridge Y-12 Plant has had an active program to find alternatives for these solvents used in cleaning applications for the past 7 years. During this time frame, the quantity of solvents purchased has been reduced by 92%. The program has been a twofold effort. Vapor degreasers used in batch cleaning-operations have been replaced by ultrasonic cleaning with aqueous detergent, and other organic solvents have been identified for use in hand-wiping or specialty operations. In order to qualify these alternatives for use, experimentation was conducted on cleaning ability as well as effects on subsequent operations such as welding, painting and bonding. Cleaning ability was determined using techniques such as X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) which are capable of examining monolayer levels of contamination on a surface. Solvents have been identified for removal of rust preventative oils, lapping oils, machining coolants, lubricants, greases, and mold releases. Solvents have also been evaluated for cleaning urethane foam spray guns, swelling of urethanes and swelling of epoxies.

Thompson, L.M.; Simandl, R.F.

1994-12-31

99

A coordination chemistry study of hydrated and solvated cationic vanadium ions in oxidation states +III, +IV, and +V in solution and solid state  

PubMed Central

The coordination chemistry of hydrated and solvated vanadium(III), oxovanadium(IV), and dioxovanadium(V) ions in the oxygen donor solvents water, dimethylsulfoxide (dmso) and N,N?-dimethylpropyleneurea (dmpu) has been studied in solution by EXAFS and large angle X-ray scattering (LAXS) and in solid state by single crystal X-ray diffraction and EXAFS. The hydrated vanadium(III) ion has a regular octahedral configuration with a mean V-O bond distance of 1.99 Å. In the hydrated and dimethylsulfoxide solvated oxovanadium(IV) ions vanadium binds strongly to an oxo group at ca. 1.6 Å. The solvent molecule trans to the oxo group is very weakly bound, at ca. 2.2 Å, while the remaining four solvent molecules, with a mean V-O bond distance of 2.0 Å, form a plane slightly below the vanadium atom; the mean O=V-Operp bond angle is ca. 98°. In the dmpu solvated oxovanadium(IV) ion, the space demanding properties of the dmpu molecule leaving no solvent molecule in the trans position to the oxo group which reduces the coordination number to 5. The O=V-O bond angle is consequently much larger, 106°, and the mean V=O and V-O bond distances decrease to 1.58 and 1.97 Å, respectively. The hydrated and dimethylsulfoxide solvated dioxovanadium(V) ions display a very distorted octahedral configuration with the oxo groups in cis position with mean V=O bond distances of 1.6 Å and a O=V=O bond angle of ca. 105°. The solvent molecules trans to the oxo groups are weakly bound, at ca. 2.2 Å, while the remaining two have bond distances of 2.02 Å. The experimental studies of the coordination chemistry of hydrated and solvated vanadium(III,IV,V) ions are complemented by summarizing previously reported crystal structures to yield a comprehensive description of the coordination chemistry of vanadium with oxygen donor ligands.

Krakowiak, Joanna; Lundberg, Daniel

2012-01-01

100

A coordination chemistry study of hydrated and solvated cationic vanadium ions in oxidation states +III, +IV, and +V in solution and solid state.  

PubMed

The coordination chemistry of hydrated and solvated vanadium(III), oxovanadium(IV), and dioxovanadium(V) ions in the oxygen-donor solvents water, dimethyl sulfoxide (DMSO), and N,N'-dimethylpropyleneurea (DMPU) has been studied in solution by extended X-ray absorption fine structure (EXAFS) and large-angle X-ray scattering (LAXS) and in the solid state by single-crystal X-ray diffraction and EXAFS. The hydrated vanadium(III) ion has a regular octahedral configuration with a mean V-O bond distance of 1.99 Å. In the hydrated and DMSO-solvated oxovanadium(IV) ions, vanadium binds strongly to an oxo group at ca. 1.6 Å. The solvent molecule trans to the oxo group is very weakly bound, at ca. 2.2 Å, while the remaining four solvent molecules, with a mean V-O bond distance of 2.0 Å, form a plane slightly below the vanadium atom; the mean O?V-O(perp) bond angle is ca. 98°. In the DMPU-solvated oxovanadium(IV) ion, the space-demanding properties of the DMPU molecule leave no solvent molecule in the trans position to the oxo group, which reduces the coordination number to 5. The O?V-O bond angle is consequently much larger, 107°, and the mean V?O and V-O bond distances decrease to 1.58 and 1.97 Å, respectively. The hydrated and DMSO-solvated dioxovanadium(V) ions display a very distorted octahedral configuration with the oxo groups in the cis position with a mean V?O bond distance of 1.6 Å and a O?V?O bond angle of ca. 105°. The solvent molecules trans to the oxo groups are weakly bound, at ca. 2.2 Å, while the remaining two have bond distances of 2.02 Å. The experimental studies of the coordination chemistry of hydrated and solvated vanadium(III,IV,V) ions are complemented by summarizing previously reported crystal structures to yield a comprehensive description of the coordination chemistry of vanadium with oxygen-donor ligands. PMID:22950803

Krakowiak, Joanna; Lundberg, Daniel; Persson, Ingmar

2012-09-05

101

`Weak A' phenotypes  

PubMed Central

Thirty-five weak A samples including fourteen A3, eight Ax, seven Aend, three Am and three Ae1 were studied in order to determine their A antigen site density, using an IgG anti-A labelled with 125I. The values obtained ranged between 30,000 A antigen sites for A3 individuals, and 700 sites for the Ae1 red cells. The hierarchy of values observed made it possible to establish a quantitative relationship between the red cell agglutinability of these phenotypes measured under standard conditions, and their antigen site density.

Cartron, J. P.; Gerbal, A.; Hughes-Jones, N. C.; Salmon, C.

1974-01-01

102

Scripting Coordination Styles  

Microsoft Academic Search

The fact that so many different kinds of coordination models and lan- guages have been proposed suggests that no one single approach will be the best for all coordination problems. Different coordination styles exhibiting different properties may be more suitable for some problems than others. Like other archi- tectural styles, coordination styles can be expressed in terms of components, con-

Franz Achermann; Stefan Kneubuehl; Oscar Nierstrasz

2000-01-01

103

Weakly noisy chaotic scattering  

NASA Astrophysics Data System (ADS)

The effect of a weak source of noise on the chaotic scattering is relevant to situations of physical interest. We investigate how a weak source of additive uncorrelated Gaussian noise affects both the dynamics and the topology of a paradigmatic chaotic scattering problem as the one taking place in the open nonhyperbolic regime of the Hénon-Heiles Hamiltonian system. We have found long transients for the time escape distributions for critical values of the noise intensity for which the particles escape slower as compared with the noiseless case. An analysis of the survival probability of the scattering function versus the Gaussian noise intensity shows a smooth curve with one local maximum and with one local minimum which are related to those long transients and with the basin structure in phase space. On the other hand, the computation of the exit basins in phase space shows a quadratic curve for which the basin boundaries lose their fractal-like structure as noise turned on.

Bernal, Juan D.; Seoane, Jesús M.; Sanjuán, Miguel A. F.

2013-09-01

104

Halogenated solvent remediation  

DOEpatents

Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding an electron donor for microbe-mediated anaerobic reductive dehalogenation of the halogenated solvents, which electron donor enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative electron donors include C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof, of which lactic acid, salts of lactic acid--such as sodium lactate, lactate esters, and mixtures thereof are particularly illustrative. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the electron donor.

Sorenson, Jr., Kent S. (Windsor, CO)

2008-11-11

105

Influence of binary swelling solvents: Mechanism of action  

SciTech Connect

This study addresses the dramatic up-take of a poor swelling solvent in Argonne Premium Coal Samples (APCS), Illinois No. 6, Beulah-Zap and Lewiston-Stockton when such a solvent is spiked with various amounts of the strong swelling solvent, pyridine. The unexpected up-take can be explained in terms of four different processes: (1) disruption of weak hydrogen bonds which isolate the interconnected micropore system; (2) disruption of weak hydrogen bonds which protect individual micropores; (3) competition of pyridine for the active sites involved in the hydrogen bonds or the {open_quotes}poisoning{close_quotes} of active sites; and (4) disruption of stronger hydrogen bonds within the macromolecules which causes an opening of the structure. When more than 5% pyridine is used, no additional disruption of the hydrogen-bonded network occurs. The structural changes were monitored by spin probe incorporation which was measured by EPR spectroscopy.

Ding, R.; Tucker, D.; Kispert, L.D.

1995-12-31

106

Weak Acid Equilibrium  

NSDL National Science Digital Library

Students are asked to calculate the pH of a weak acid aqueous solution. The problems involve a series of generic acids with assigned equilibrium constants (Ka) and total concentrations (Ct). Initially, students are required to hand calculate all problems by algebraic manipulation of the mathematical relationships of the system. The solution is a cubic equation. Through a series of assumptions, the solution is simplified. The assumptions are based on the chemistry of the system given the Ka and Ct for the problem. The problems are then graphically solved. Ultimately, the students develop an Excel worksheet to solve the problems and a Bjerrum plot to display the speciation as a function of pH.

Stapleton, Michael

107

Weak lensing and dark energy  

Microsoft Academic Search

We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some dark-energy models predict additional clustering on very large scales, but this probably cannot be detected by weak lensing alone due to cosmic variance.

Dragan Huterer

2002-01-01

108

Controlling chemical self-assembly by solvent-dependent dynamics.  

PubMed

The influence of the ratio between poor and good solvent on the stability and dynamics of supramolecular polymers is studied via a combination of experiments and simulations. Step-wise addition of good solvent to supramolecular polymers assembled via a cooperative (nucleated) growth mechanism results in complete disassembly at a critical good/poor solvent ratio. In contrast, gradual disassembly profiles upon addition of good solvent are observed for isodesmic (non-nucleated) systems. Due to the weak association of good solvent molecules to monomers, the solvent-dependent aggregate stability can be described by a linear free-energy relationship. With respect to dynamics, the depolymerization of ?-conjugated oligo(p-phenylene vinylene) (OPV) assemblies in methylcyclohexane (MCH) upon addition of chloroform as a good solvent is shown to proceed with a minimum rate around a critical chloroform/MCH solvent ratio. This minimum disassembly rate bears an intriguing resemblance to phenomena observed in protein unfolding, where minimum rates are observed at the thermodynamic midpoint of a protein denaturation experiment. A kinetic nucleation-elongation model in which the rate constants explicitly depend on the good solvent fraction is developed to rationalize the kinetic traces and further extend the insights by simulation. It is shown that cooperativity, i.e., the nucleation of new aggregates, plays a key role in the minimum polymerization and depolymerization rate at the critical solvent composition. Importantly, this shows that the mixing protocol by which one-dimensional aggregates are prepared via solution-based processing using good/poor solvent mixtures is of major influence on self-assembly dynamics. PMID:22808949

Korevaar, Peter A; Schaefer, Charley; de Greef, Tom F A; Meijer, E W

2012-08-02

109

Weakly bound states of the He-He-Mg trimer  

SciTech Connect

We search for the existence of the weakly bound He-He-Mg molecules. The He-He-Mg molecule is treated as a three-body system. By using hyperspherical coordinates, the Schroedinger equation for the triatomic system is solved in the adiabatic approximation. We obtain that the binding of the three atoms is possible. The binding energies of such molecules are estimated.

Li Yong; Huang Deping [Department of Physics, Huazhong Normal University, Wuhan 430079 (China); Gou Qingdong [Department of Physics, Huazhong Normal University, Wuhan 430079 (China); College of Mathematics and Physics, Jinggangshan University, Ji'an 343009 (China); Han Huili; Shi Tingyun [Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

2011-07-15

110

Design choices for weak-consistency group communication  

Microsoft Academic Search

Many wide-area distributed applications can be implemented using distributed group communica- tion, a mechanism for coordinating the activities of related processes running at different sites. We have developed a modular architecture for group communication systems that can be used to build a system tailored to application requirements. We focus on weak consistency mechanisms for group communication, since these allow highly

Richard A. Golding; Darrell D. E. Long

1992-01-01

111

Competitive Complexation by Ligand and Solvent: Polarographic Characterization of ATRP Catalyst Polyamine–Copper Complexes in Acetonitrile + Water Mixed Solvents  

Microsoft Academic Search

In the Atom Transfer Radical Polymerization (ATRP) technique, the suggested polymerization scheme is pivoted by a metal complex acting as a redox catalyst able to coordinate with the incipient radicals. The development of an a priori criterion of choice of the best (complex + solvent) combination is one of the current topics in this field. In this context we performed

Giuseppe Di Silvestro; Cui Ming Yuan; Patrizia Romana Mussini

2004-01-01

112

Solvent Evaporation Rates  

Microsoft Academic Search

A system of equations for predicting the evaporation rates of solvents is presented. These equations may be used by the industrial hygienist, in conjunction with the diffusion equations developed elsewhere, to predict the atmospheric concentrations of vapors from spilled toxic liquids. The equations are derived from wind tunnel tests and applied to predictions for spills both indoors and outdoors.

DOUGLAS C. GRAY

1974-01-01

113

Organic solvent topical report  

SciTech Connect

This report is the technical basis for the accident and consequence analyses used in the Hanford Tank Farms Basis for Interim Operation. The report also contains the scientific and engineering information and reference material needed to understand the organic solvent safety issue. This report includes comments received from the Chemical Reactions Subcommittee of the Tank Advisory Panel.

Cowley, W.L.

1998-04-30

114

Organic solvent topical report  

SciTech Connect

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed.

COWLEY, W.L.

1999-05-13

115

Hazardous solvent source reduction  

Microsoft Academic Search

This book is written for the managers, production leaders, and operations staff tasked with the job of eliminating hazardous cleaning solvents from their workplace. Information regarding the location, evaluation, and implementation of environmentally preferred cleaning technologies is offered for a broad range of applications. These include: removal of grease and grime from a piece of equipment during maintenance, cleaning small

M. S. Callahan; B. Green

1995-01-01

116

Weak Boundary Layers in Styrene-Butadiene Rubber  

Microsoft Academic Search

In this paper two kinds of weak boundary layers (WBL) in synthetic vulcanized styrene-butadiene rubber are described.i) WBL produced by the presence of antiadhesion compounds of the rubber formulation (zinc stearate, microcrystalline paraffin wax). These WBL cannot be effectively removed by solvent wiping, whether followed by washing with an ethanol\\/water mix or not. Although this treatment allowed a significant removal

M. M. Pastor-Blas; M. S. Sánchez-Adsuar; J. M. Martín-Martínez

1995-01-01

117

General Curvilinear Coordinate Systems.  

National Technical Information Service (NTIS)

The basic ideas of the construction and use of numerically-generated boundary-fitted coordinate systems for the numerical solution of partial differential equations are discussed. With such coordinate systems, all computation can be done on a fixed square...

J. F. Thompson

1982-01-01

118

The effect of solvent on solvent refined coal (SRC) denitrification  

Microsoft Academic Search

Wyodak coal containing 0.93Vertical Bar3< by wt nitrogen was hydrogenated in a batch autoclave by heating 2:1 by wt coal\\/solvent mixtures to 715°K at 2000 psi hydrogen. The solvents used were a Wyodak coal recycle solvent (RS), RS mildly or severely hydrogenated over a Co-Mo\\/AlâOâ catalyst, light and heavy fractions distilled from the above solvents, and two coal tars from

David W. Staubs; Ronald L. Miller; Howard F. Silver; Robert J. Hurtubise

1979-01-01

119

Cook-Coordinate Plane  

NSDL National Science Digital Library

Become familiar with the coordinate plane. Learn the quadrants and how to graph points and read points on a coordinate plane. You are required to do the assignment and take the quiz. The other resources are to help prepare you for the quiz and book assignment. This is a quick review of the lesson.The Coordinate Plane This is a game to practice plotting and reading points.coordinates game *Assignment: Watch Powerpoint 3.3 and fill in your ...

Cook, Miss

2010-10-12

120

Reaction coordinates for electron transfer reactions  

SciTech Connect

The polarization fluctuation and energy gap formulations of the reaction coordinate for outer sphere electron transfer are linearly related to the constant energy constraint Lagrangian multiplier m in Marcus' theory of electron transfer. The quadratic dependence of the free energies of the reactant and product intermediates on m and m+1, respectively, leads to similar dependence of the free energies on the reaction coordinates and to the same dependence of the activation energy on the reorganization energy and the standard reaction free energy. Within the approximations of a continuum model of the solvent and linear response of the longitudinal polarization to the electric field in Marcus' theory, both formulations of the reaction coordinate are expected to lead to the same results.

Rasaiah, Jayendran C. [Department of Chemistry, University of Maine, Orono, Maine 04469 (United States); Zhu Jianjun [Department of Chemistry, State University of New York, Stonybrook, New York 11790 (United States) and Department of Chemistry, Henan Normal University, Xinxiang, Henan (China)

2008-12-07

121

Coordinates, Conversions, and Kinematics  

Microsoft Academic Search

This is a guide to coordinate systems, representations, and geometric relationships between them, for components of the Rochester Robotics Laboratory. The main entities at issue are the joint angles, location variables, and coordinate systems of the Puma, the camera angles and coordinate systems associated with the head, the spatial location of three-dimensional points, and the kinematic and inverse kinematic relationships

Christopher M. Brown; Raymond D. Rimey

122

Cartesian Coordinate System  

NSDL National Science Digital Library

This lesson is designed to develop students' understanding of the Cartesian coordinate plane. Topics include plotting coordinates and slope. This lesson provides links to discussions and activities related to the Cartesian coordinate system as well as suggested ways to integrate them into the lesson. Finally, the lesson provides links to follow-up lessons designed for use in succession with the current one.

2010-01-01

123

Literacy Coordinators' Handbook.  

ERIC Educational Resources Information Center

|This handbook is designed to provide support for England's National Literacy Strategy's Literacy Coordinators leading and coordinating literacy across the school. The handbook is designed as a working document and will contain additional materials, LEA (local education authorities) guidance, and additional papers which Coordinators may choose to…

Department for Education and Skills, London (England).

124

LCLS Undulator Coordinate System  

SciTech Connect

This note defines the LCLS undulator coordinate system and relates that coordinate system to the linear accelerator coordinate system. The slight downward pitch of the SLAC linac and the finite radius of the Earth necessitate some choices and definitions for the undulator layout which is described here. The layout described is consistent with the LCLS optics MAD file ''LCLS13APR04''.

Bong, E.

2005-01-31

125

Processing Coordination Ambiguity  

ERIC Educational Resources Information Center

|We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based theories assume…

Engelhardt, Paul E.; Ferreira, Fernanda

2010-01-01

126

Prenarcotic and neuraesthenic symptoms among Dutch workers exposed to organic solvents.  

PubMed Central

A population of 379 Dutch workers exposed to organic solvents was compared with a non-exposed population of 443 workers with regard to the prevalence of prenarcotic and neuraesthenic symptoms. Participants completed a questionnaire to collect information about their occupational history, exposure to organic solvents, and the occurrence of symptoms. The results of the study indicated that workers exposed to solvents have a higher reporting rate of prenarcotic symptoms than workers not exposed to solvents. The prevalence of chronic neurotoxic effects, however, in the form of neuraesthenic symptoms was only weakly associated with reported exposure to organic solvents. The influence of work stress in the development of these symptoms is perhaps more important than the role of exposure to organic solvents. It is concluded that the organic solvent syndrome type I, as defined by an international workshop, is not an important health hazard among Dutch painters.

van Vliet, C; Swaen, G M; Meijers, J M; Slangen, J; de Boorder, T; Sturmans, F

1989-01-01

127

Environment-Based Coordination Through Coordination Artifacts  

Microsoft Academic Search

\\u000a In the context of human organisations, environment plays a fundamental role for supporting cooperative work and, more generally,\\u000a complex coordination activities. Support is realised through services, tools, artifacts shared and exploited by the collectivity of individuals for achieving individual as well as global objectives.\\u000a \\u000a \\u000a The conceptual framework of coordination artifacts is meant to bring the same sort of approach to

Alessandro Ricci; Mirko Viroli; Andrea Omicini

2004-01-01

128

Solvent substitution for electronic products  

SciTech Connect

Allied-Signal Inc., Kansas City Division (KCD), manufactures the electrical, electrochemical, mechanical, and plastic components for nuclear weapons. The KCD has made a commitment to eliminate the use of chlorohydrocarbon (CHC) and chlorofluorocarbon (CFC) solvents to the greatest technical extent possible consistent with nuclear safety and stockpile reliability requirements. Current cleaning processes in the production departments use trichloroethylene, 1,1,1-trichloroethane, and various CFC-113 based solvents. Several non-halogenated solvents (Solvent A - an aqueous solvent based on N,N-dimethylacetamide, Solvent B - an aqueous mixture of ethanol amines, Solvent C - a hydrocarbon solvent based on octadecyl acetate, Solvent D - a terpene (d-limonene) hydrocarbon solvent combined with emulsifiers, Solvent E - a terpene (d-limonene) hydrocarbon solvent combined with a separation agent, d-limonene, and isopropyl alcohol) were evaluated to determine the most effective, non-chlorinated, non-fluorinated, alternate solvent cleaning system. All of these solvents were evaluated using current manual spray cleaning processes. The solvents were evaluated for their effectiveness in removing a rosin based RMA solder flux, a particular silicone mold release, and oils, greases, mold releases, resins, etc. The Meseran Surface Analyzer was used to measure organic contamination on the samples before and after cleaning. An Omega Meter Model 600 was also used to detect solder flux residues. Solvents C, D, E and d-limonene the best alternatives to trichloroethylene for removing all of the contaminants tested. For this particular electronic assembly, d-limonene was chosen as the alternate because of material compatibility and long-term reliability concerns.

Benkovich, M.K.

1992-01-01

129

Weighing Neutrinos: Weak Lensing Approach  

Microsoft Academic Search

We study the possibility for a measurement of neutrino mass using weak\\u000agravitational lensing. The presence of non-zero mass neutrinos leads to a\\u000asuppression of power at small scales and reduces the expected weak lensing\\u000asignal. The measurement of such a suppression in the weak lensing power\\u000aspectrum allows a direct measurement of the neutrino mass, in contrast to\\u000avarious

Asantha R. Cooray

1999-01-01

130

PARIS II: DESIGNING GREENER SOLVENTS  

EPA Science Inventory

PARIS II (the program for assisting the replacement of industrial solvents, version II), developed at the USEPA, is a unique software tool that can be used for customizing the design of replacement solvents and for the formulation of new solvents. This program helps users avoid ...

131

Weak measurements of light chirality with a plasmonic slit.  

PubMed

We examine, both experimentally and theoretically, an interaction of tightly focused polarized light with a slit on a metal surface supporting plasmon-polariton modes. Remarkably, this simple system can be highly sensitive to the polarization of the incident light and offers a perfect quantum weak measurement tool with a built-in postselection in the plasmon-polariton mode. We observe the plasmonic spin Hall effect in both coordinate and momentum spaces which is interpreted as weak measurements of the helicity of light with real and imaginary weak values determined by the input polarization. Our experiment combines the advantages of (i) quantum weak measurements, (ii) near-field plasmonic systems, and (iii) high-numerical aperture microscopy in employing the spin-orbit interaction of light and probing light chirality. PMID:23031106

Gorodetski, Y; Bliokh, K Y; Stein, B; Genet, C; Shitrit, N; Kleiner, V; Hasman, E; Ebbesen, T W

2012-07-05

132

SOLVENT FIRE BY-PRODUCTS  

SciTech Connect

Southwest Research Institute (SwRI) conducted a burn test of the Caustic-Side Solvent Extraction (CSSX) solvent to determine the combustion products. The testing showed hydrogen fluoride gas is not a combustion product from a solvent fire when up to 70% of the solvent is consumed. The absence of HF in the combustion gases may reflect concentration of the modifier containing the fluoride groups in the unburned portion. SwRI reported results for other gases (CO, HCN, NOx, formaldehyde, and hydrocarbons). The results, with other supporting information, can be used for evaluating the consequences of a facility fire involving the CSSX solvent inventory.

Walker, D; Samuel Fink, S

2006-05-22

133

Hyperconjugation-mediated solvent effects in phosphoanhydride bonds  

PubMed Central

Density functional theory and Natural Bond Orbital analysis are used to explore the impact of solvent on hyperconjugation in methyl triphosphate, a model for “energy rich” phosphoanhydride bonds, such as found in ATP. As expected, dihedral rotation of a hydroxyl group vicinal to the phosphoanhydride bond reveals that the conformational dependence of the anomeric effect involves modulation of the orbital overlap between the donor and acceptor orbitals. However, a conformational independence was observed in the rotation of a solvent hydrogen bond. As one lone pair orbital rotates away from an optimal anti-periplanar orientation, the overall magnitude of the anomeric effect is compensated approximately by the other lone pair as it becomes more anti-periplanar. Furthermore, solvent modulation of the anomeric effect is not restricted to the anti-periplanar lone pair; hydrogen bonds involving gauche lone pairs also affect the anomeric interaction and the strength of the phosphoanhydride bond. Both gauche and anti solvent hydrogen bonds lengthen non-bridging O—P bonds, increasing the distance between donor and acceptor orbitals, and decreasing orbital overlap which leads to a reduction of the anomeric effect. Solvent effects are additive with greater reduction in the anomeric effect upon increasing water coordination. By controlling the coordination environment of substrates in an active site, kinases, phosphatases and other enzymes important in metabolism and signaling, may have the potential to modulate the stability of individual phosphoanhydride bonds through stereoelectronic effects.

Summerton, Jean C.; Evanseck, Jeffrey D.; Chapman, Michael S.

2012-01-01

134

Epidemiology of organic solvents and connective tissue disease  

Microsoft Academic Search

Case reports suggest that solvents are associated with various\\u0009\\u0009\\u0009 connective tissue diseases (systemic sclerosis, scleroderma, undifferentiated\\u0009\\u0009\\u0009 connective tissue disease, systemic lupus erythematosis, and rheumatoid\\u0009\\u0009\\u0009 arthritis), particularly systemic sclerosis. A small number of epidemiological\\u0009\\u0009\\u0009 studies have shown statistically significant but weak associations between\\u0009\\u0009\\u0009 solvent exposure, systemic sclerosis, and undifferentiated connective tissue\\u0009\\u0009\\u0009 disease. However, the interpretation of these positive findings is tempered

David H Garabrant; Constantine Dumas

2000-01-01

135

Universal weakly secure network coding  

Microsoft Academic Search

This paper considers the problem of secure network coding under the weak (and practically appealing) security requirements of Bhattad and Narayanan. Weak security allows communication at maximum rate while ensuring that only meaningless information is leaked to a wiretapper. Differently from the approach of Bhattad and Narayanan, which requires a joint design of the underlying network code and the outer

Danilo Silva; Frank R. Kschischang

2009-01-01

136

Intestinal Transport of Weak Electrolytes  

PubMed Central

A study has been made of the transmural fluxes of benzoic, phenylacetic, and pentanoic acids, benzylamine, hexylamine, and D-amphetamine across rat jejunum incubated in vitro. The M to S fluxes of the weak acids were greater than their corresponding S to M fluxes, and the S to M fluxes of the weak bases were larger than their M to S fluxes. These patterns of asymmetric movements were observed when the transmural electrical potential difference was clamped at 0 mV, and when the pH values of the mucosal and serosal fluids were identical. The effects of a weak acid on the fluxes of other weak electrolytes were qualitatively similar when the effector weak acid was added to the mucosal fluid, and when it was added to the serosal fluid. But the effects of a weak base on the fluxes of other weak electrolytes were dependent upon its location, and the interactions observed when the effector weak base was added to the mucosal fluid were qualitatively different than those seen when it was added to the serosal fluid. The interactions between weak electrolytes could readily be explained in terms of the function of a system of three compartments in series, in which the pH of the intermediate compartment is greater than that of the bulk phases. But these observations could not be explained in terms of an analogous system involving an intermediate compartment of low pH, or in terms of a carrier mediated system. The transport function of the three-compartment system can be described in the form of an equation, and it is found that a pH difference of less than 0.5 unit may explain our observations on weak electrolyte transport.

Jackson, Michael J.; Shiau, Yih-Fu; Bane, Susan; Fox, Margaret

1974-01-01

137

Explicitly computing geodetic coordinates from Cartesian coordinates  

NASA Astrophysics Data System (ADS)

This paper presents a new form of quartic equation based on Lagrange's extremum law and a Groebner basis under the constraint that the geodetic height is the shortest distance between a given point and the reference ellipsoid. A very explicit and concise formulae of the quartic equation by Ferrari's line is found, which avoids the need of a good starting guess for iterative methods. A new explicit algorithm is then proposed to compute geodetic coordinates from Cartesian coordinates. The convergence region of the algorithm is investigated and the corresponding correct solution is given. Lastly, the algorithm is validated with numerical experiments.

Zeng, H.

2013-04-01

138

Solvent response and dielectric relaxation in supercooled butyronitrile  

NASA Astrophysics Data System (ADS)

We have measured the dynamics of solvation of a triplet state probe, quinoxaline, in the glass-forming dipolar liquid butyronitrile near its glass transition temperature Tg=95 K. The Stokes shift correlation function displays a relaxation time dispersion of considerable magnitude and the optical linewidth changes along the solvation coordinate in a nonmonotonic fashion. These features are characteristic of solvation in viscous solvents and clearly indicate heterogeneous dynamics, i.e., spatially distinct solvent response times. Using the dielectric relaxation data of viscous butyronitrile as input, a microscopic model of dipolar solvation captures the relaxation time, the relaxation dispersion, and the amplitude of the dynamical Stokes shift remarkably well.

Ito, Naoki; Duvvuri, Kalyan; Matyushov, Dmitry V.; Richert, Ranko

2006-07-01

139

Solvated-ion-pairing-sensitive molecular bistability based on copper(I)-coordinated pyrimidine ring rotation.  

PubMed

We describe herein the effect of solvated ion pairing on the molecular motion of a pyrimidine ring coordinated on a copper center. We synthesized a series of heteroleptic copper(I) complex salts bearing an unsymmetrically substituted pyridylpyrimidine and a bulky diphosphine. Two rotational isomers of the complexes were found to coexist and interconvert in solution via intramolecular ligating atom exchange of the pyrimidine ring, where the notation of the inner (i-) and outer (o-) isomers describes the orientation of the pyrimidine ring relative to the copper center. The stability of the pyrimidine orientation was solvent- and counterion-sensitive in both 2·BF(4) {2(+) = [Cu(Mepypm)(dppp)](+), where Mepypm = 4-methyl-2-(2'-pyridyl)pyrimidine and dppp = 1,3-bis(diphenylphosphino)propane} and previously reported 1·BF(4), which possesses a bulky diphosphine ligand (1(+) = [Cu(Mepypm)(DPEphos)](+), where DPEphos = bis[2-(diphenylphosphino)phenyl] ether). Two rotational isomers of 2(+) were separately obtained as single crystals, and the structure of each isomer was examined in detail. Both the enthalpy and entropy values for the rotation of 2·BF(4) in CDCl(3) (?H = 6 kJ mol(-1); ?S = 25 J K(-1) mol(-1)) were more positive than that tested under other conditions, such as in more polar solvents CD(2)Cl(2), acetone-d(6), and CD(3)CN. The reduced contact of the anion to the cation in a polar solvent seems to contribute to the enthalpy, entropy, and Gibbs free energy for rotational isomerization. This speculation based on solvated ion pairing was further confirmed by considering the rotational behavior of 2(+) with a bulky counterion, such as B(C(6)F(5))(4)(-). The findings are valuable for the design of molecular mechanical units that can be readily tuned via weak electrostatic interactions. PMID:23237520

Nishikawa, Michihiro; Nomoto, Kuniharu; Kume, Shoko; Nishihara, Hiroshi

2012-12-13

140

Tax Coordination and Unemployment  

Microsoft Academic Search

This paper analyses the implications of unemployment for fiscal competition and tax coordination among small open economies.\\u000a Unemployment is modeled as resulting from wage bargaining. The analysis focuses on the effect of labour and capital tax coordination\\u000a on welfare. We show that, while coordinated capital and labour tax increases unambiguously raise welfare if labour markets\\u000a are competitive, different results emerge

Clemens Fuest; Bernd Huber

1999-01-01

141

Solution Phase Measurement of Both Weak Sigma and C-H---X- Hydrogen Bonding Interactions in Synthetic Anion Receptors  

SciTech Connect

A series of tripodal receptors preorganize electron-deficient aromatic rings to bind halides in organic solvents using weak sigma anion-to-arene interactions or C-H---X- hydrogen bonds. 1H NMR spectroscopy proves to be a powerful technique for quantifying binding in solution, and determining the interaction motifs, even in cases of weak binding.

Berryman, Mr. Orion B. [University of Oregon; Sather, Mr. Aaron C [University of Oregon; Hay, Benjamin [ORNL; Meisner, Mr. Jeffrey S. [University of Oregon; Johnson, Prof. Darren W. [University of Oregon

2008-01-01

142

Hartman effect and weak measurements that are not really weak  

SciTech Connect

We show that in wave packet tunneling, localization of the transmitted particle amounts to a quantum measurement of the delay it experiences in the barrier. With no external degree of freedom involved, the envelope of the wave packet plays the role of the initial pointer state. Under tunneling conditions such ''self-measurement'' is necessarily weak, and the Hartman effect just reflects the general tendency of weak values to diverge, as postselection in the final state becomes improbable. We also demonstrate that it is a good precision, or a 'not really weak' quantum measurement: no matter how wide the barrier d, it is possible to transmit a wave packet with a width {sigma} small compared to the observed advancement. As is the case with all weak measurements, the probability of transmission rapidly decreases with the ratio {sigma}/d.

Sokolovski, D. [Department of Chemical Physics, University of the Basque Country, 48940 Leioa (Spain); IKERBASQUE, Basque Foundation for Science, Alameda Urquijo, 36-5, Plaza Bizkaia, 48011, Bilbao, Bizkaia (Spain); Akhmatskaya, E. [Basque Center for Applied Mathematics (BCAM), Building 500, Bizkaia Technology Park, E-48160 Derio (Spain)

2011-08-15

143

Carbon-13 nuclear magnetic resonance spectra of potassium (ethylenediaminetetraacetato)cobaltate(III) in organic solvents  

SciTech Connect

The carbon-13 NMR spectra of the (Co(edta))/sup /minus// (edta = ethylenediaminetetraacetate) anion were observed in water and a variety of organic solvents: ethylene glycol, methanol, formamide, ethanol, 2-propanol, chloroform, dichloromethane, dimethyl sulfoxide, acetonitrile, dimethylformamide, benzonitrile, and dimethylacetamide. The spectra in organic solvents were obtained after 1-2-h accumulations for the concentrated solutions (0.5 M) of the complex anion that were prepared by the addition of a macrobicyclic polyether, cryptand 222, to the solvents. The /sup 13/C NMR signals of the coordinated carboxylates are markedly shifted downfield in protic solvents in comparison with aprotic solvent (the greatest difference in chemical shift is 3.9 ppm), while the NMR chemical shifts of methylene carbons of ligands are not significantly influenced by solvent molecules. The magnitudes (/sigma/ values) of this downfield shift of the coordinated carboxylate /sup 13/C signals are found to be correlated linearly with the electrophilic ability of the solvent molecules. This finding leads to the conclusion that the (Co(edta))/sup /minus// anion interacts with solvent molecules through the hydrogen-bonding between solvent hydrogens and carboxyl oxygens of the complex anion. 10 references, 4 figures, 1 table.

Taura, Toshiaki

1988-08-10

144

Weak-shock reflection factors  

SciTech Connect

The purpose of this paper is to compare reflection factors for weak shocks from various surfaces, and to focus attention on some unsolved questions. Three different cases are considered: square-wave planar shock reflection from wedges; square-wave planar shock reflection from cylinders; and spherical blast wave reflection from a planar surface. We restrict ourselves to weak shocks. Shocks with a Mach number of M{sub O} < 1.56 in air or with an overpressure of {Delta}{sub PI} < 25 psi (1.66 bar) under normal ambient conditions are called weak.

Reichenbach, H. [Ernst Mach Inst., Freiburg (Germany); Kuhl, A.L. [Lawrence Livermore National Lab., El Segundo, CA (United States)

1993-09-07

145

Resisting Weakness of the Will  

PubMed Central

I develop an account of weakness of the will that is driven by experimental evidence from cognitive and social psychology. I will argue that this account demonstrates that there is no such thing as weakness of the will: no psychological kind corresponds to it. Instead, weakness of the will ought to be understood as depletion of System II resources. Neither the explanatory purposes of psychology nor our practical purposes as agents are well-served by retaining the concept. I therefore suggest that we ought to jettison it, in favour of the vocabulary and concepts of cognitive psychology.

Levy, Neil

2012-01-01

146

Heme coordination of prostaglandin H synthase.  

PubMed

The heme coordination of ovine prostaglandin H synthase (PGHS) has been characterized by EPR, magnetic circular dichroism, resonance Raman, and optical spectroscopies. The EPR spectrum of ferric PGHS is consistent with an equilibrium mixture of high-spin and low-spin heme species. Both species disappear on reaction of the synthase with hydroperoxides. The high-spin to low-spin interconversion is temperature- and concentration-dependent. Correlation between the axial and rhombic ligand fields of the low-spin heme species suggests that it has bishistidine axial ligation. Magnetic circular dichroism spectra of PGHS also show a temperature-dependent spin transition. Resonance Raman spectra indicate that the enzyme exists as a mixture of six-coordinate low-spin and six-coordinate high-spin ferric heme species. No Raman bands attributable to five-coordinate high-spin heme species are detectable. The magnetic circular dichroism spectra of the fluoride, azide, cyanide, and imidazole derivatives of PGHS resemble those of the corresponding metmyoglobin derivatives and are very different from those of the catalase derivatives. EPR spectra of the imidazole derivative of these three proteins provide additional evidence that the heme coordination structure of PGHS is similar to that of metmyoglobin rather than that of catalase. The midpoint potential of the PGHS Fe(III)/Fe(II) pair is in the range observed for hemeproteins with mono- or bishistidine coordination. These data provide a convincing case that the axial heme ligands of PGHS-1 are a pair of histidine residues, with the distal histidine weakly associated and possibly exchangeable with a weak-field ligand. PMID:8386163

Tsai, A L; Kulmacz, R J; Wang, J S; Wang, Y; Van Wart, H E; Palmer, G

1993-04-25

147

Energy transport via coordination bonds  

NASA Astrophysics Data System (ADS)

Vibrational energy transport in transition metal complexes involves stages where energy crosses relatively weak coordination bonds between a coordinated metal atom and the ligands. Understanding the energy transport rules on a molecular level is fundamentally important; it is also essential in relation to a recently proposed structural method, the relaxation-assisted two-dimensional infrared (RA 2DIR) technique, where the vibrational population transport time across the molecule of interest is linked to the transport distance. In this study we report on the energy transport across coordination bonds in tetraethylammonium bis(maleonitriledithiolate)iron(III)nitrosyl complex, studied using dual-frequency RA 2DIR spectroscopy. Three mode pairs, C?N and N=O, N=O and C?N, and N=O and C-C, were interrogated. All three cross-peaks show substantial amplification due to vibrational energy transport from the initially excited mode toward the ``probed'' mode, including a record amplification of 27-fold observed for the C?N/N=O cross-peak. A ninefold amplification measured for the N=O/C?N cross-peak, where the ``probed'' CN mode has higher frequency than the initially excited NO, proves unequivocally that the excitation of the ``probed'' mode via energy transport is not essential for observing stronger cross-peaks and that lower frequency modes serve as the energy accepting modes. A simple modeling of the energy transport is presented highlighting the role of a spatial overlap of the interacting modes. The observed strong cross-peak amplifications and a correlation between the energy transport time and the intermode distance, the distance between atom pairs on which vibrational excitations predominantly reside, demonstrate an applicability of the RA 2DIR method for structural interrogation of transition metal complexes.

Kasyanenko, Valeriy M.; Lin, Zhiwei; Rubtsov, Grigory I.; Donahue, James P.; Rubtsov, Igor V.

2009-10-01

148

Heliospheric coordinate systems  

Microsoft Academic Search

This article gives an overview and reference to the most common coordinate systems currently used in space science. While coordinate systems used in near-Earth space physics have been described in previous work we extend that description to systems used for physical observations of the Sun and the planets and to systems based on spacecraft location. For all systems, we define

M. Fränz; D. Harper

2002-01-01

149

Metric Coordinate Systems  

Microsoft Academic Search

Coordinate systems are defined on general metric spaces with the purpose of generalizing vector fields on a manifold. Conversion formulae are available between metric and Cartesian coordinates on a Hilbert space. Nagumo's Invariance Theorem is invoked to prove the analogue of the classical Cauchy-Lipschitz Theorem for vector fields on a locally compact coordinatized space. A metric space version of Nagumo's

Craig Calcaterra; Axel Boldt; Michael Green; David Bleecker

2002-01-01

150

Social Postural Coordination  

ERIC Educational Resources Information Center

|The goal of the current study was to investigate whether a visual coupling between two people can produce spontaneous interpersonal postural coordination and change their intrapersonal postural coordination involved in the control of stance. We examined the front-to-back head displacements of participants and the angular motion of their hip and…

Varlet, Manuel; Marin, Ludovic; Lagarde, Julien; Bardy, Benoit G.

2011-01-01

151

Weak interactions and presupernova evolution  

SciTech Connect

The role of weak interactions, particularly electron capture and {beta}{sup {minus}} decay, in presupernova evolution is discussed. The present uncertainty in these rates is examined and the possibility of improving the situation is addressed. 12 refs., 4 figs.

Aufderheide, M.B. (Lawrence Livermore National Lab., CA (USA) State Univ. of New York (USA). Dept. of Physics)

1991-02-19

152

Orthographic star coordinates.  

PubMed

Star coordinates is a popular projection technique from an nD data space to a 2D/3D visualization domain. It is defined by setting n coordinate axes in the visualization domain. Since it generally defines an affine projection, strong distortions can occur: an nD sphere can be mapped to an ellipse of arbitrary size and aspect ratio. We propose to restrict star coordinates to orthographic projections which map an nD sphere of radius r to a 2D circle of radius r. We achieve this by formulating conditions for the coordinate axes to define orthographic projections, and by running a repeated non-linear optimization in the background of every modification of the coordinate axes. This way, we define a number of orthographic interaction concepts as well as orthographic data tour sequences: a scatterplot tour, a principle component tour, and a grand tour. All concepts are illustrated and evaluated with synthetic and real data. PMID:24051828

Lehmann, Dirk J; Theisel, Holger

2013-12-01

153

Weak to strong pinning crossover.  

PubMed

Material defects in hard type II superconductors pin the flux lines and thus establish the dissipation-free current transport in the presence of a finite magnetic field. Depending on the density and pinning force of the defects and the vortex density, pinning is either weak collective or strong. We analyze the weak to strong pinning crossover of vortex matter in disordered superconductors and discuss the peak effect appearing naturally in this context. PMID:14995270

Blatter, G; Geshkenbein, V B; Koopmann, J A G

2004-02-13

154

Aspects of dihydrogen coordination chemistry relevant to reactivity in aqueous solution  

Microsoft Academic Search

The aqueous coordination chemistry of dihydrogen has potential applications in inorganic biomimicry, chemoselective hydrogenation catalysis, and green chemistry. However, experimental and mechanistic studies that explore the aqueous behavior of these complexes are virtually unknown. This review identifies the motivation for studying aqueous dihydrogen coordination complexes by providing a summary of reactions that involve a dihydrogen ligand in highly polar solvents.

Nathaniel K. Szymczak; David R. Tyler

2008-01-01

155

Coordination sequences and coordination waves in matter  

SciTech Connect

A possible way of partitioning a space into polycubes (n-dimensional modifications of Golomb polyominoes, which are generally nonconvex) is used as a basic model of ordered matter structure. It is suggested that layer-by-layer growth of a structure, occurring along the geodetics of the digraph of a net defined by the local rules of bonding of polycubes, justifies the phenomenological laws of shaping (self-similarity during the growth, independence of the polyhedron shape on the 'seed,' the symmetry of the growth polyhedron, etc.). Specific results of the analysis of number sequences of the increase in coordination circles for planar periodic partitions of model and real crystal structures, as well as the preliminary results of investigation of standing coordination topological waves, revealed for the first time in computer experiments, are reported.

Rau, V. G., E-mail: vgrau@mail.ru; Pugaev, A. A.; Rau, T. F. [Vladimir State Pedagogical University (Russian Federation)

2006-01-15

156

Hazardous solvent source reduction  

SciTech Connect

This book is written for the managers, production leaders, and operations staff tasked with the job of eliminating hazardous cleaning solvents from their workplace. Information regarding the location, evaluation, and implementation of environmentally preferred cleaning technologies is offered for a broad range of applications. These include: removal of grease and grime from a piece of equipment during maintenance, cleaning small parts before assembly, defluxing printed circuit boards and assemblies, and stripping paint from field vehicles and aircraft. Moving beyond the limits of source reduction alone, this book provides complete information on the planning, staffing, and execution of a pollution prevention program, alternative and in-use cleaner testing, waste recycling and treatment, air emission control, replacement system design, and system economics. For the environmental specialist, this book helps to bridge the gap between regulatory requirements and shop-floor constraints.

Callahan, M.S.; Green, B.

1995-09-01

157

Solvent-Solvent Energy Migration in Liquid Scintillation. Part Ii.  

National Technical Information Service (NTIS)

The quenching of benzene monomer fluorescence by biacetyl at 28C is studied as a function of dilution with hexane and cyclohexane. The component of the overall transfer rate constant, attributable to solvent-solvent energy migration is shown to vary linea...

J. W. van Loben Sels J. T. Dubois

1966-01-01

158

Neuropathy - Coordination Exam - Lower Extremities Sub-exam - Patient 7  

NSDL National Science Digital Library

This video demonstrates a coordination exam of the lower extremities. This 61-year-old man has had slowly progressive gait disturbance and weakness of his legs for 14 years. He has developed a limp in both legs, and his feet trip on objects and on uneven floor surfaces resulting in falls. Weakness and numbness of the legs is limiting his ability to walk. Viewing the video requires installation of the free QuickTime Plug-in.

Pearson, John C.

2009-01-02

159

Correlation of surface tension of mixed solvents with solvent composition.  

PubMed

A simple computational method for calculating surface tension of solvent mixtures based on the Redlich-Kister extension was proposed. The model was applied to the experimental surface tension of binary solvent mixtures and showed accurate results. Overall average percentage deviation (APD) between calculated and experimental surface tensions was calculated as an accuracy criterion. The overall APD for correlating surface tensions in binary solvents was 4.30%. The accuracy of the proposed model has also been compared with those of previously published models and the results showed that the proposed model was superior and capable of providing more accurate results. An extension of the model was also proposed to correlate surface tension of ternary solvents and the overall APD for ternary solvent data was 2.06%. PMID:15638082

Jouyban, A; Azarbayjani, A Fathi; Barzegar-Jalali, M; Acree, W E

2004-12-01

160

Porous coordination polymer with flexibility imparted by coordinatively changeable lithium ions on the pore surface.  

PubMed

Solvothermal reactions of equimolar zinc acetate, lithium acetate, and 1,3,5-benzenetricarboxylic acid (H(3)btc) in different mixed solvents yielded isostructural three-dimensional frameworks [LiZn(btc)(cG)].lG [cG and lG denote coordinated and lattice guests, respectively; cG = (nmp)(0.5)(H(2)O)(0.5), lG = (EtOH)(0.5) (1a); cG = H(2)O, lG = EtOH (1b); nmp = N-methyl-2-pyrrolidone] with one-dimensional channels occupied by guest molecules and solvent-coordinated, extrusive Li(+) ions. Thermogravimetry analyses and powder X-ray diffraction measurements revealed that both 1a and 1b can lose all lattice and coordinated guests to form a desolvated phase [LiZn(btc)] (MCF-27, 1) and almost retains the original framework structure. Gas adsorption measurements on 1 confirmed its permanent porosity but suggested a structural transformation from 1a/1b to 1. It is noteworthy that only 1a can undergo a single-crystal to single-crystal (SCSC) transformation into 1 upon desolvation. The crystal structure of 1 revealed that the Li(+) ions were retracted into the channel walls via complementary coordination to the carboxylate oxygen atoms in the framework rather than being exposed on the pore surface. Single-crystal X-ray diffraction analyses were also performed for N(2)- and CO(2)-loaded samples of 1, revealing that the framework remained unchanged when the gases were adsorbed. Although the gas molecules could not be modeled, the residue electrons inside the channels demonstrated that the retracted Li(+) ions still behave as the primary interacting site for CO(2) molecules. Nevertheless, solvent molecules such as H(2)O can readily compete with the framework oxygen atom to retrieve the extrusive Li(+) ions, accompanying the reverse structural transformation, i.e., from 1 to 1a/1b. PMID:20050697

Xie, Lin-Hua; Lin, Jian-Bin; Liu, Xiao-Min; Wang, Yu; Zhang, Wei-Xiong; Zhang, Jie-Peng; Chen, Xiao-Ming

2010-02-01

161

Conformational transitions of weak polyacids grafted to nanoparticles  

NASA Astrophysics Data System (ADS)

The charge distribution on polyelectrolytes is a key factor, which controls their conformation and interactions. In weak polyelectrolytes, this distribution is determined by a number of factors, including the solvent conditions and local environment. In this work, we investigate charge distributions of chains end-grafted on a spherical nanoparticle in a salt solution, using grand canonical titration Monte Carlo simulations of a coarse-grained polymer model. In this approach, the ionization state of each polymer bead fluctuates based on the dissociation constant, pH of the solution, and interactions with other particles in the system. We determine charge and polymer conformations as functions of the pH and solvent quality. We compare the results to a fixed charge model and also investigate the role of grafting density and the effect of curvature on the film morphologies.

Barr, S. A.; Panagiotopoulos, A. Z.

2012-10-01

162

Uranyl ion coordination  

USGS Publications Warehouse

A review of the known crystal structures containing the uranyl ion shows that plane-pentagon coordination is equally as prevalent as plane-square or plane-hexagon. It is suggested that puckered-hexagon configurations of OH - or H2O about the uranyl group will tend to revert to plane-pentagon coordination. The concept of pentagonal coordination is invoked for possible explanations of the complex crystallography of the natural uranyl hydroxides and the unusual behavior of polynuclear ions in hydrolyzed uranyl solutions.

Evans, Jr. , H. T.

1963-01-01

163

Solvent Retention and Fibre Chemistry.  

National Technical Information Service (NTIS)

The aim of this study was to understand in which way different chemical and physical treatments affect the solvent retention properties of pulps used in the middle layer of folding boxboard. The solvent retention properties of the treated pulps were exami...

M. Rantanen

2003-01-01

164

SOLV-DB: Solvents Database  

NSDL National Science Digital Library

The purpose of SOLV-DB is to help you find a wide variety of data on solvents quickly and easily, including health and safety data, chemical and physical data, regulatory responsibilities, and environmental fate information. SOLV-DB is maintained by the National Center for Manufacturing Sciences and is considered a "one-stop source for solvents data."

2008-08-27

165

Desorption of chlorine organic solvents  

Microsoft Academic Search

Adsorption methods are being used more and more widely to treat gaseous discharges containing chlorohydrocarbons. However, recovery of the chlorohydrocarbons has not been studied sufficiently, and the desorption of the solvents with steam is particularly understudied. We investigated desorption of a number of solvents from industrial active carbon AR-3. Desorption was done with live steam in the 105 to 150°C.

N. I. Petrova; K. M. Nikolaev

1982-01-01

166

Laboratory solvent reuse -- Liquid chromatography  

SciTech Connect

The objective of this work was to develop a method for reduction of waste solvent in the Process Engineering Chemistry Laboratory. The liquid chromatographs are the largest generators of explosive-contaminated waste in the laboratory. We developed a successful process for the reuse of solvents from the liquid chromatographs and demonstrated the utility of the process in the assay of hexanitrostilbene.

Quinlin, W.T.; Schaffer, C.L.

1992-11-01

167

Exxon donor solvent liquefaction process  

Microsoft Academic Search

The Exxon donor solvent (EDS) coal liquefaction system is a direct liquefaction procedure. Coal is chemically reacted and dissolved in a recycle solvent that is hydrogenated between passes to the liquefaction reactor. More than 2.6 barrels of a synthetic crude boiling below 1000 F are produced per ton of dry, high volatile coal feed. Other ranks of coal can be

R. C. Neavel

1981-01-01

168

Peripheral facial weakness (Bell's palsy).  

PubMed

Peripheral facial weakness is a facial nerve damage that results in muscle weakness on one side of the face. It may be idiopathic (Bell's palsy) or may have a detectable cause. Almost 80% of peripheral facial weakness cases are primary and the rest of them are secondary. The most frequent causes of secondary peripheral facial weakness are systemic viral infections, trauma, surgery, diabetes, local infections, tumor, immune disorders, drugs, degenerative diseases of the central nervous system, etc. The diagnosis relies upon the presence of typical signs and symptoms, blood chemistry tests, cerebrospinal fluid investigations, nerve conduction studies and neuroimaging methods (cerebral MRI, x-ray of the skull and mastoid). Treatment of secondary peripheral facial weakness is based on therapy for the underlying disorder, unlike the treatment of Bell's palsy that is controversial due to the lack of large, randomized, controlled, prospective studies. There are some indications that steroids or antiviral agents are beneficial but there are also studies that show no beneficial effect. Additional treatments include eye protection, physiotherapy, acupuncture, botulinum toxin, or surgery. Bell's palsy has a benign prognosis with complete recovery in about 80% of patients, 15% experience some mode of permanent nerve damage and severe consequences remain in 5% of patients. PMID:24053080

Basi?-Kes, Vanja; Dobrota, Vesna Dermanovi?; Cesarik, Marijan; Matovina, Lucija Zadro; Madzar, Zrinko; Zavoreo, Iris; Demarin, Vida

2013-06-01

169

Weak Selection and Protein Evolution  

PubMed Central

The “nearly neutral” theory of molecular evolution proposes that many features of genomes arise from the interaction of three weak evolutionary forces: mutation, genetic drift, and natural selection acting at its limit of efficacy. Such forces generally have little impact on allele frequencies within populations from generation to generation but can have substantial effects on long-term evolution. The evolutionary dynamics of weakly selected mutations are highly sensitive to population size, and near neutrality was initially proposed as an adjustment to the neutral theory to account for general patterns in available protein and DNA variation data. Here, we review the motivation for the nearly neutral theory, discuss the structure of the model and its predictions, and evaluate current empirical support for interactions among weak evolutionary forces in protein evolution. Near neutrality may be a prevalent mode of evolution across a range of functional categories of mutations and taxa. However, multiple evolutionary mechanisms (including adaptive evolution, linked selection, changes in fitness-effect distributions, and weak selection) can often explain the same patterns of genome variation. Strong parameter sensitivity remains a limitation of the nearly neutral model, and we discuss concave fitness functions as a plausible underlying basis for weak selection.

Akashi, Hiroshi; Osada, Naoki; Ohta, Tomoko

2012-01-01

170

Weakness  

MedlinePLUS

... cancer that has spread to the spinal cord Multiple sclerosis Less common causes: Many other conditions sometimes cause ... Sometimes seizures MRI or CT of the brain Multiple sclerosis (affects the brain, spinal cord or both) Usually ...

171

Solvent influence on base stacking.  

PubMed Central

In this paper we present a detailed analysis of the base-stacking phenomenon in different solvents, using nanosecond molecular dynamics simulations. The investigation focuses on deoxyribo- and ribodinucleoside monophosphates in aqueous and organic solutions. Organic solvents with a low dielectric constant, such as chloroform, and solvents with intermediate dielectric constants, such as dimethyl sulfoxide and methanol, were analyzed. This was also done for water, which is highly polar and has a high dielectric constant. Structural parameters such as the sugar puckering and the base-versus-base orientations, as well as the energetics of the solute-solvent interactions, were examined in the different solvents. The obtained data demonstrate that base stacking is favored in the high dielectric aqueous solution, followed by methanol and dimethyl sulfoxide with intermediate dielectric constants, and chloroform, with a low dielectric constant.

Norberg, J; Nilsson, L

1998-01-01

172

Local Coordinates Model  

NSDL National Science Digital Library

The Local Coordinates model displays the position of a star in local (Altitude/Azimuth) coordinates. The horizon is shown along with the four cardinal directions (N, E, S, and W). The latitude of the observer is set at 35.5 degrees which sets the location of the north celestial pole (teal) relative to the northern horizon. The position of the star can be changed by using the Altitude and Azimuth sliders. The Local Coordinates model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_astronomy_Local Coordinates.jar file will run the program if Java is installed. EJS is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models.

Belloni, Mario; Timberlake, Todd

2010-01-02

173

Unapproved Drugs Coordinator  

Center for Drug Evaluation (CDER)

Text Version... Nancy Smith Office of New Drugs John Jenkins ... and Research (CDER) Office of Counter- Terrorism and Emergency Coordination ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

174

Carbonate formation within a nickel dimer: synthesis of a coordinatively unsaturated bis(mu-hydroxo) dinickel complex and its reactivity toward carbon dioxide.  

PubMed

The tridentate aminopyridine ligand bearing a bulky tert-butyl substituent at the amine nitrogen, tert-butyl-dipicolylamine (tBuDPA), occupies three coordination sites in six-coordinate complexes of nickel(ii), leaving the remaining three sites available for additional ligand binding and activation. New crystallographically characterized complexes include two mononuclear species with 1:1 metal:ligand complexation: a trihydrate solvate (1.3H(2)O) and a monohydrate biacetonitrile solvate (1.H(2)O.2CH(3)CN). Complexation in the presence of sodium hydroxide results in a bis(mu-hydroxo) complex (2), the bridging hydroxide anions of which are labile and become displaced by methoxide anions in methanol solvent, affording bis-methoxo-bridged (4). Nickel(II) centers in 2 are five-coordinate and antiferromagnetically coupled (with J = -31.4(5) cm(-1), H = -2JS(1)S(2), in agreement with Ni-O-Ni angle of 103.7 degrees). Bridging hydroxide or alkoxide anions in coordinatively unsaturated dinuclear nickel(II) complexes with tBuDPA react as active nucleophiles. 2 readily performs carbon dioxide fixation, resulting in the formation of a bis(mu-carbonato) tetrameric complex (3), which features a novel binding geometry in the form of an inverted butterfly-type nickel-carbonate core. Temperature-dependent magnetic measurements of tetranuclear carbonato-bridged revealed relatively weak antiferromagnetic coupling (J(1) = -3.1(2) cm(-1)) between the two nickel centers in the core of the cluster, as well as weak antiferromagnetic pairwise interactions (J(2) = J(3) = -4.54(5) cm(-1)) between central and terminal nickel ions. PMID:20179843

Wikstrom, Jeffrey P; Filatov, Alexander S; Mikhalyova, Elena A; Shatruk, Michael; Foxman, Bruce M; Rybak-Akimova, Elena V

2010-01-20

175

Solvent degradation products in nuclear fuel processing solvents  

SciTech Connect

The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has identified certain solvent degradation products and suggested mitigation measures. Undecanoic acid, lauric acid, and tridecanoic acid were tentatively identified as diluent degradation products in recycle solvent. These long-chain organic acids affect phase separation and lead to low decontamination factors. Solid phase extraction (SPE) was used to concentrate the organic acids in solvent prior to analysis by high performance liquid chromatography (HPLC). SPE and HPLC methods were optimized in this work for analysis of decanoic acid, undecanoic acid, and lauric acid in solvent. Accelerated solvent degradation studies with 7.5% TBP in normal paraffin hydrocarbons showed that long-chain organic acids and long-chain alkyl butyl phosphoric acids are formed by reactions with nitric acid. Degradation of both tributyl phosphate and hydrocarbon can be minimized with purified normal paraffin replacing the standard grade presently used. 12 refs., 1 fig., 3 tabs.

Shook, H.E. Jr.

1988-06-01

176

Testing the coordination predicate  

SciTech Connect

A collection of parallel processors is said to be coordinated if each write from one processing element (PE) to another is answered by a read. The authors report on an efficient algorithm to test coordination for parallel programs in which the code for each PE is a loop. They also test a weaker predicate for parallel algorithms with oblivious PE codes, and they show that the general problem is pspace-hard. 6 references.

Cuny, J.E.; Snyder, L.

1984-03-01

177

Solvent Selection for Extraction from Dilute Solution  

Microsoft Academic Search

An improved strategy for the selection of solvents for recovery of chemicals from dilute solution is presented. Low solvent losses and a high solute distribution coefficient are primary goals for solvent selection. High relative volatility of the solvent also is an important property if the solute is to be recovered from the extract by distillation. Low solvent losses will ensure

M. C. M. Cockrem; J. H. Flatt; E. N. Lightfoot

1989-01-01

178

WASH SOLVENT REUSE IN PAINT PRODUCTION  

EPA Science Inventory

This project evaluated solvent used to clean paint manufacture equipment for its utility in production of subsequent batches of solvent-borne paint. eusing wash solvent would reduce the amount of solvent disposed of as waste. he evaluation of this wash-solvent recovery technology...

179

Helpful hints for physical solvent absorption  

Microsoft Academic Search

Review of experience with natural gas treatment using physical solvents points to design and operating suggestions. Experiences with three plants using either Selexol or Sepasolv MPE solvent shows that both solvents perform well. The solvents offer economical and problem-free purification of natural gas. The Sepasolv MPE and Selexol solvents are very similar in chemical structure and physical properties. Thus, their

Wolfer

1982-01-01

180

Comparison of Fluor Solvent and Selexol processes  

Microsoft Academic Search

Physical solvent processes can be useful for acid gas removal applications. The necessity for screening physical solvent characteristics to eliminate those solvents that are unsuitable or noncompetitive for a particular application is discussed. The Fluor Solvent and Selexol processes are compared. Selexol has an advantage over other solvents in oil applications involving HâS and COâ removal in hydrocarbon systems. Fluor

R. W. Bucklin; R. L. Schendel

1984-01-01

181

Weak-chaos ratchet accelerator  

NASA Astrophysics Data System (ADS)

Classical Hamiltonian systems with a mixed phase space and some asymmetry may exhibit chaotic ratchet effects. The most significant such effect is a directed momentum current or acceleration. In known model systems, this effect may arise only for sufficiently strong chaos. In this paper, a Hamiltonian ratchet accelerator is introduced, featuring a momentum current for arbitrarily weak chaos. The system is a realistic, generalized kicked rotor and is exactly solvable to some extent, leading to analytical expressions for the momentum current. While this current arises also for relatively strong chaos, the maximal current is shown to occur, at least in one case, precisely in a limit of arbitrarily weak chaos.

Dana, Itzhack; Roitberg, Vladislav B.

2011-06-01

182

Divalent cu, cd, and pb biosorption in mixed solvents.  

PubMed

Dead dried Chlorella vulgaris was studied in terms of its performance in binding divalent copper, cadmium, and lead ions from their aqueous or 50% v/v methanol, ethanol, and acetone solutions. The percentage uptake of cadmium ions exhibited a general decrease with decrease in dielectric constant values, while that of copper and lead ions showed a general decrease with increase in donor numbers. Uptake percentage becomes less sensitive to solvent properties the larger the atomic radius of the biosorbed ion, and uptake of copper was the most affected. FT-IR analyses revealed stability of the biomass in mixed solvents and a shift in vibrations of amide(I) and (II), carboxylate, glucose ring, and metal oxygen upon metal binding in all media. Delta(nuCOO) values (59-69 cm(-1)) confirmed bidentate metal coordination to carboxylate ligands. The value of nu(as)COO increased slightly upon Cu, Cd, and Pb biosorption from aqueous solutions indicating lowering of symmetry, while a general decrease was noticed in mixed solvents pointing to the opposite. M-O stretching frequencies increased unexpectedly with increase in atomic mass as a result of solvent effect on the nature of binding sites. Lowering polarity of the solvent permits variations in metal-alga bonds strengths; the smaller the metal ion, the more affected. PMID:19688108

Al-Qunaibit, M H

2009-08-13

183

[Exposure to solvents and tardy epilepsy: 2 clinical cases].  

PubMed

Organic solvents (OS) are widely used in industry and craft work. The neurotoxic effects of OS are well known in occupational exposure occurring in poor industrial hygiene conditions. There has been interest recently in a possible epileptogenic effect of OS exposure. Two cases are reported of late onset epilepsy observed in workers heavily exposed to OS. Case 1 was a 27-year-old male painter employed in a car body repair workshop. Solvent exposure was high for a few months because after his regular work, the man continued working as a car body painter in his own private concern. After a period of weakness and headache, probably indicating an excessive solvent absorption, he suffered two generalized paroxysmal seizures during sleep which necessitated hospitalization and continuous treatment with barbiturates. Case 2 was a 44-year-old male painter in a road advertising billboard factory who was continuously exposed to OS. Ten years previously he had been exposed to accidental massive inhalation of solvent vapours while opening a drum of solvents for coloured paint. Acute solvent poisoning followed and seven weeks later he suffered several epileptic episodes associated with typical EEG alterations; for many years, however, treatment was ineffective. In both cases there was neither a history of neurologic disease nor any other neurologic dysfunctions and the results of comprehensive neuroradiological studies were normal. Evidence exists of a chronological connection between high exposure to paint solvents and clinical evidence of late onset epilepsy, but it is not possible to identify a definite causal relationship.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1528164

Bernardini, P; Scoppetta, C

184

Dynamics of weakly localized waves.  

PubMed

We develop a transport theory to describe the dynamics of (weakly) localized waves in a quasi-1D tube geometry both in reflection and in transmission. We compare our results to recent experiments with microwaves and to other theories, such as random matrix theory and supersymmetric theory. PMID:15089135

Skipetrov, S E; van Tiggelen, B A

2004-03-15

185

Weak Approximations for Wiener functionals  

Microsoft Academic Search

In this paper we introduce a simple space-filtration discretization scheme on Wiener space which allows us to study weak decompositions and smooth explicit approximations for a large class of Wiener functionals. We show that any Wiener functional has an underlying robust semimartingale skeleton which under mild conditions converges to it. The discretization is given in terms of discrete-jumping filtrations which

Dorival Leao; Alberto Ohashi

2009-01-01

186

Weak Intera ction and Cosmology  

Microsoft Academic Search

In this letter we examine the connection among the themes: the cosmological constant, the weak interaction and the neutrino mass. Our main pr opose is to review and modify the ideas first propo sed by Hayakawa ( Prog. Theor. Phys. Suppl. ,532(1965).), in the ligth of the new-fashioned fea tures of contemporary physics. Assuming the pressure of a Fermi gas

P. R. Silva

187

{tau} weak magnetic dipole moment  

SciTech Connect

The weak magnetic dipole moment of the {tau}-lepton is reviewed. Standard Model predictions and the last experimental results are presented. These may result in a stringent test for both their point-like structure and also for new physics.

Gonzalez-Sprinberg, Gabriel [Facultad de Ciencias, Universidad de la Rep'ublica Montevideo (Uruguay)

1998-10-05

188

Vibrations of weakly coupled nanoparticles  

Microsoft Academic Search

The vibrations of a coupled pair of isotropic silver spheres are investigated and compared with the vibrations of the single isolated spheres. Situations of both strong coupling and also weak coupling are investigated using continuum elasticity and perturbation theory. The numerical calculation of the eigenmodes of such dimers is augmented with a symmetry analysis. This checks the convergence and applicability

Lucien Saviot; Daniel B. Murray

2010-01-01

189

Swelling of lignites in organic solvents  

SciTech Connect

Data on the swelling of Turkish lignites can be summarized using linear multiparameter equations that take into account various properties of solvents. Factors responsible for the amounts of absorbed solvents are the basicity and cohesion energy density of the solvents.

R.G. Makitra; D.V. Bryk [Institute of the Geology and Geochemistry of Fossil Fuels, Lviv (Ukraine)

2008-10-15

190

Gemini world coordinates  

NASA Astrophysics Data System (ADS)

The Gemini World Coordinate Systems (WCS) facilities support various types of astrometric coordinates as well as instrument-specific quantities such as wavelengths or times. The astrometric facilities are based on the principle that, for sky-imaging applications, users are concerned only with (i) positions in the focal plane and (ii) celestial coordinates. All intermediate calculations, for example involving the position of the tip/tilt secondary mirror, the orientation of the instrument rotator, the selection of focal station, differential refraction and atmospheric dispersion, and field rotation effects caused by misalignments in the telescope mount, are encapsulated in the WCS transformation. We have implemented a library of C functions which support Gemini astrometric world coordinates. Most of them can be run off-line, and are applicable to other telescopes. More general WCS problems, involving data coordinates as well as astrometry, are treated by breaking the telescope, instrument and detector into a set of 'agents' each of which manages its own local transformations. The individual transformations can then be combined to provide the end-to-end transformations needed by data display and analysis facilities.

Wallace, Patrick T.

1998-05-01

191

Competing weak localization and weak antilocalization in ultrathin topological insulators  

NASA Astrophysics Data System (ADS)

We demonstrate the evidences of a surface gap opening in (Bi0.57Sb0.43)2Te3 samples for film thickness below 6 quintuple layers, through magnetotransport and scanning tunneling spectroscopy measurements. By tuning Fermi level position relative to the gap, the striking crossover between weak antilocalization and weak localization is observed in nonmagnetic 4 and 5 QL films at low field region, a characteristic feature of quantum interferences competition, possibly owing to the change of net Berry phase. Furthermore, when the Fermi level is swept into the surface gap, the overall unitary behaviors are revealed at higher magnetic field, which are in contrast to the pure WAL signals obtained in thicker films. Besides, the surface bandgap of ultrathin film is also determined by low temperature STS measurements. Our findings show an exotic phenomenon characterizing the gapped TI surface states and point to the future realization of quantum spin Hall effect and dissipationless TI-based applications.

Lang, Murong; He, Liang; Kou, Xufeng; Upadhyaya, Pramey; Fan, Yabin; Chu, Hao; Yeh, Nai-Chang; Wang, Kang

2013-03-01

192

Improved Purex Solvent Scrubbing Methods.  

National Technical Information Service (NTIS)

Studies of hydrazine and hydroxylamine salts as solvent scrubbing agents that can be decomposed into gases are summarized. Results from testing of countercurrent scrubbers and solid sorber columns that produce lesser amounts of permanent salts are reporte...

J. C. Mailen O. K. Tallent

1984-01-01

193

SAGE--SOLVENT ALTERNATIVES GUIDE  

EPA Science Inventory

SAGE is a comprehensive guide designed to provide pollution prevention information on solvent and process alternatives for parts cleaning and degreasing. SAGE does not recommend any ozone depleting chemicals. SAGE was developed by the Surface Cleaning Program at Research Triang...

194

Coordinating overcurrent protection devices  

SciTech Connect

Distribution, substation, and plant engineers can benefit from using an overcurrent protection program in commercial, industrial, and utility applications to aid in clearing temporary faults and isolating permanent faults. In the time it normally takes to check one coordination scheme manually, dozens of alternatives can be evaluated using a graphics-oriented program, because the engineer receives immediate feedback for quick decision-making. It is well known that accurately coordinating overcurrent protection devices can minimize or prevent equipment damage, and electrical power service to customers can be greatly improved. In addition to assisting experienced engineers, an overcurrent protection program is an excellent training tool for new engineers.

St. John, M.; Borgnino, A.

1996-07-01

195

Coordinate Standard Measurement Development  

SciTech Connect

A Shelton Precision Interferometer Base, which is used for calibration of coordinate standards, was improved through hardware replacement, software geometry error correction, and reduction of vibration effects. Substantial increases in resolution and reliability, as well as reduction in sampling time, were achieved through hardware replacement; vibration effects were reduced substantially through modification of the machine component dampening and software routines; and the majority of the machine's geometry error was corrected through software geometry error correction. Because of these modifications, the uncertainty of coordinate standards calibrated on this device has been reduced dramatically.

Hanshaw, R.A.

2000-02-18

196

Exxon Donor Solvent Liquefaction Process  

Microsoft Academic Search

The Exxon Donor Solvent (EDS) coal liquefaction system is a direct liquefaction procedure being developed by the Exxon Corporation. Coal is chemically reacted and dissolved in a recycle solvent that is hydrogenated between passes to the liquefaction reactor. More than 2.6 barrels (0.41 m3) of a synthetic crude boiling below 1000 degrees F (538 degrees C) are produced per ton

R. C. Neavel

1981-01-01

197

Overdamping by weakly coupled environments  

SciTech Connect

A quantum system weakly interacting with a fast environment usually undergoes a relaxation with complex frequencies whose imaginary parts are damping rates quadratic in the coupling to the environment in accord with Fermi's 'golden rule'. We show for various models (spin damped by harmonic-oscillator or random-matrix baths, quantum diffusion, and quantum Brownian motion) that upon increasing the coupling up to a critical value still small enough to allow for weak-coupling Markovian master equations, a different relaxation regime can occur. In that regime, complex frequencies lose their real parts such that the process becomes overdamped. Our results call into question the standard belief that overdamping is exclusively a strong coupling feature.

Esposito, Massimiliano; Haake, Fritz [Center for Nonlinear Phenomena and Complex Systems, Universite Libre de Bruxelles, Code Postal 231, Campus Plaine, B-1050 Brussels (Belgium); Fachbereich Physik, Universitaet Duisburg-Essen, 45117 Essen (Germany)

2005-12-15

198

QCD corrections to weak decays  

SciTech Connect

Weak decays are significantly altered by effects of strong interaction. In the K system these corrections give rise to {Delta}I = 1/2 rule, and have measurable effects on rare weak process like K{yields}{pi}{nu}{bar {nu}}, K{yields}{pi}e{sup +}e{sup {minus}} and {var epsilon}{prime}/{var epsilon}. The situation in the K system is briefly reviewed. Strong interaction effects are also important in D and B system. A possible mechanism for D{sup +}-D{sup 0} life-time difference is reviewed and then rare B processes are dealt with extensively. Electromagnetic penguin diagrams are enhanced by QCD corrections, giving rise to process like B{yields}K{sup {asterisk}}{gamma} and B{yields}Ke{sup +}e{sup {minus}}. Process mediated by gluon penguins are also discussed. 24 refs., 8 figs.

Deshpande, N.G.

1989-06-01

199

Weak localization of photon noise  

NASA Astrophysics Data System (ADS)

We present an experimental study of coherent backscattering (CBS) of photon noise from multiple scattering media. We use a pseudothermal light source with a microsecond coherence time to produce a noise spectrum covering a continuous transition, from wave fluctuations to shot noise over several MHz. The angle-dependent Fano factor of backscattered light shows an enhancement due to CBS in the wave fluctuation regime. The CBS line shape and enhancement factor of the noise power is consistent with theory in the weak-scattering limit and for a large number of open reflection channels. These initial experiments on weakly scattering media demonstrate that sensitive noise measurements can be combined with the separation of path lengths present in CBS, opening up new experiments on noise transport in the localization regime.

Scalia, Paolo S.; Muskens, Otto L.; Lagendijk, Ad

2013-10-01

200

Weak Coupling in 143Nd  

NASA Astrophysics Data System (ADS)

The high-spin states of 143Nd have been studied in the 130Te(18O, 5n)143Nd reaction at a beam energy of 80 MeV using techniques of in-beam ?-ray spectroscopy. Measurements of ? - ? - t coincidences, ?-ray angular distributions, and ?-ray linear polarizations were performed. A level scheme of 143Nd with spin and parity assignments up to 53/2+ is proposed. While a weak coupling model can explain the level structure up to the J?=39/2- state, this model can not reproduce the higher-lying states. Additionally, a new low-lying non-yrast level sequence in 143Nd was observed in the present work, which can be well described by the weak coupling of an i13/2 neutron to the 142Nd core nucleus.

Zhou, Xiao-Hong; E, Ideguchi; T, Kishida; M, Ishihara; H, Tsuchida; Y, Gono; T, Morikawa; M, Shibata; H, Watanabe; M, Miyake; T, Tsutsumi; S, Motomura; S, Mitarai

2000-04-01

201

Mechanisms of Skeletal Muscle Weakness  

Microsoft Academic Search

\\u000a Skeletal muscle weakness is an important feature of numerous ­pathological conditions and it may also be a component in normal\\u000a ageing. Decreased muscular strength can be due to decreased muscle mass and\\/or intrinsic defects in the muscle cells. In this\\u000a chapter we will discuss decreased force production due to mechanisms intrinsic to skeletal muscle cells. We will mainly use\\u000a data

Håkan Westerblad; Takashi Yamada

202

Functional weakness and sensory disturbance  

PubMed Central

In the diagnosis of functional weakness and sensory disturbance, positive physical signs are as important as absence of signs of disease. Motor signs, particularly Hoover's sign, are more reliable than sensory signs, but none should be used in isolation and must be interpreted in the overall context of the presentation. It should be borne in mind that a patient may have both a functional and an organic disorder.

Stone, J; Zeman, A; Sharpe, M

2002-01-01

203

The Neutral Weak Vector Boson.  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. The properties of the neutral weak vector boson are investigated both in the framework of the standard electroweak theory and in a dynamical model of compositeness. In SU(2) x U(1), the electromagnetic properties of the Z are studied paying a particular attention to the treatment of the anomalous triangle diagrams. The Z to 3gamma together with the scattering of light by light amplitudes are shown to be finite and to satisfy current conservation by using a non-linear gauge. A low-energy theorem for Z production is presented. This allows for a simple derivation of the leading electromagnetic corrections to e^+ e^- to Zgamma near threshold (where LEPI will be operating). Within a composite model for quarks, leptons and weak bosons we show how the weak mixing angle, "sin Theta_{rm w}", can be dynamically generated. In this approach large electromagnetic couplings for the Z are predicted. The anomalous couplings may be observed in e^+e ^- to Zgamma or e^+e^- to ZZ at LEPII where the Z is longitudinally polarized. The composite model also requires an extra neutral vector boson, the Y. From low-energy experiments an absolute lower bound on its mass has been set: M_{rm y} > 350 GeV. As a by product, translating the ideas, used for composite weak bosons, to strong interaction of vector mesons, the rho^{rm o} rightarrow gamma and omega^{rm o} rightarrow gamma mixing parameters are derived in terms of the fundamental parameters of QCD.

Boudjema, Fawzi

204

Simulations of Nanoparticle Ordering in Polymer Brush/Solvent Mixtures  

NASA Astrophysics Data System (ADS)

Organizing nanoparticles into a desired super-structure is crucial for their technological applications. We present molecular dynamics simulations of the assembly of nanoparticles during the evaporation of solvent from 3-component mixtures of nanoparticles and solvent in contact with an end-grafted polymer brush. The organization of nanoparticles strongly depends on their interaction with polymer chains. For relatively weak attraction between the nanoparticles and brush, the nanoparticles straddle the brush surface and form an ordered lattice. For a strong attraction between the nanoparticles and polymer, the nanoparticles are engulfed inside the brush and the packing quality diminishes, because the lateral diffusion of the nanoparticles is suppressed. The opposite trend is observed in the case in which the polymer chains are not grafted to a substrate. In this case, a layer of nanoparticles is entrapped in the concentrated polymer film at the interface and assemble into a close-packed hexagonal lattice for strong mutual attraction, while for weak interactions the nanoparticles are mostly dispersed in the relatively solvent-rich solution below the interface and remain disordered.

Grest, Gary S.; Cheng, Shengfeng; Stevens, Mark J.

2013-03-01

205

Coordination in Turnout Games  

Microsoft Academic Search

We present a stochastic model of coordination in turnout games. In each period a randomly selected voter receives information about current play through noisy polls and then, based on this information, forms expectations about the current conÞguration of play and chooses a best response. We prove the existence of a unique limiting distribution for the process and show that even

Daniel Diermeier; Jan A. Van Mieghem

2000-01-01

206

Coordinated stasis: An overview  

Microsoft Academic Search

Coordinated stasis, as defined herein, represents an empirical pattern, common in the fossil record, wherein groups of coexisting species lineages display concurrent stability over extended intervals of geologic time separated by episodes of relatively abrupt change. In marine benthic fossil assemblages, where the pattern was first recognized, the majority of species lineages (60 to more than 80%) are present in

Carlton E. Brett; Linda C. Ivany; Kenneth M. Schopf

1996-01-01

207

Coordination of hand shape.  

PubMed

The neural control of hand movement involves coordination of the sensory, motor, and memory systems. Recent studies have documented the motor coordinates for hand shape, but less is known about the corresponding patterns of somatosensory activity. To initiate this line of investigation, the present study characterized the sense of hand shape by evaluating the influence of differences in the amount of grasping or twisting force, and differences in forearm orientation. Human subjects were asked to use the left hand to report the perceived shape of the right hand. In the first experiment, six commonly grasped items were arranged on the table in front of the subject: bottle, doorknob, egg, notebook, carton, and pan. With eyes closed, subjects used the right hand to lightly touch, forcefully support, or imagine holding each object, while 15 joint angles were measured in each hand with a pair of wired gloves. The forces introduced by supporting or twisting did not influence the perceptual report of hand shape, but for most objects, the report was distorted in a consistent manner by differences in forearm orientation. Subjects appeared to adjust the intrinsic joint angles of the left hand, as well as the left wrist posture, so as to maintain the imagined object in its proper spatial orientation. In a second experiment, this result was largely replicated with unfamiliar objects. Thus, somatosensory and motor information appear to be coordinated in an object-based, spatial-coordinate system, sensitive to orientation relative to gravitational forces, but invariant to grasp forcefulness. PMID:21389230

Pesyna, Colin; Pundi, Krishna; Flanders, Martha

2011-03-01

208

Sun Position (Polar Coordinates)  

NSDL National Science Digital Library

This applet shows the current (realtime) Sun position as seen from a polar view above the North pole. The elevation and azimuth of the Sun are given, and a brief description of celestial coordinates and celestial spheres is covered as well. A demonstration of this applet is available to download.

Giesen, Juergen

209

Coordinating overcurrent protection devices  

Microsoft Academic Search

Distribution, substation, and plant engineers can benefit from using an overcurrent protection program in commercial, industrial, and utility applications to aid in clearing temporary faults and isolating permanent faults. In the time it normally takes to check one coordination scheme manually, dozens of alternatives can be evaluated using a graphics-oriented program, because the engineer receives immediate feedback for quick decision-making.

M. St. John; A. Borgnino

1996-01-01

210

Models of Coordination  

Microsoft Academic Search

While software is becoming decomposed in more and more finegrained entities, the interactions amongst those become of major importance. While method- ologies for building such components are well established, the design and support of their interplay can not build on commonly understood and well defined models. In this paper, we review several coordination models from various disciplines, and describe how

Robert Tolksdorf

2000-01-01

211

Coordinate Plane Set Detective  

ERIC Educational Resources Information Center

|This article describes an activity in which students plot collections of ordered pairs according to prescribed set conditions. The coordinate plane sets can have rich variety, and their construction fosters critical thinking, attention to detail, and algebraic reasoning. (Contains 3 figures.)|

Beigie, Darin

2004-01-01

212

[Civilian-military coordination].  

PubMed

Current humanitarian emergencies create complex, mutidimensional situations that stimulate simultaneous responses from a wide variety of sources including governments, non-governmental organizations (NGO), United Nations agencies, and private individuals. As a result, it has become essential to establish a coherent framework in which each actor can contribute promptly and effectively to the overall effort. This is the role of the United Nations Office for the Coordination of Humanitarian Affairs. Regardless of the circumstances and level of coordination, cooperation and collaboration between humanitarian and military personnel, it is necessary to bear in mind their objectives. The purpose of humanitarian action is to reduce human suffering. The purpose of military intervention is to stop warfare. The author of this article will discuss the three major obstacles to civilian-military coordination (strategic, tactical, and operational). Operations cannot be conducted smoothly and differences cannot be ironed out without mutual respect between the two parties, an explicit definition of their respective duties and responsibilities, a clear understanding of their cultural differences, and the presence of an organization and facilities for coordination and arbitrage by a neutral referee. PMID:12534190

de Montravel, G

2002-01-01

213

Chaos as coordination technology  

Microsoft Academic Search

The need of supporting office work with suitable computer based tools implies the investigation of the deep aspects of cooperation within the office. Cooperation, to the extent that is made up of communication and coordination, can be fully characterized under the assumption that an office is a special linguistic game, constituted by a set of rules defining the conversations possible

F. De Cindio; G. De Michelis; C. Simone; R. Vassallo; A. M. Zanaboni

1986-01-01

214

Coordination of Hand Shape  

PubMed Central

The neural control of hand movement involves coordination of the sensory, motor and memory systems. Recent studies have documented the motor coordinates for hand shape, but less is known about the corresponding patterns of somatosensory activity. To initiate this line of investigation, the present study characterized the sense of hand shape by evaluating the influence of differences in the amount of grasping or twisting force, and differences in forearm orientation. Human subjects were asked to use the left hand to report the perceived shape of the right hand. In Experiment 1, six commonly grasped items were arranged on the table in front of the subject: bottle, doorknob, egg, notebook, carton, pan. With eyes closed, subjects used the right hand to lightly touch, forcefully support or imagine holding each object, while 15 joint angles were measured in each hand with a pair of wired gloves. The forces introduced by supporting or twisting did not influence the perceptual report of hand shape, but for most objects, the report was distorted in a consistent manner by differences in forearm orientation. Subjects appeared to adjust the intrinsic joint angles of the left hand, as well as the left wrist posture, so as to maintain the imagined object in its proper spatial orientation. In a second experiment, this result was largely replicated with unfamiliar objects. Thus somatosensory and motor information appear to be coordinated in an object-based, spatial coordinate system, sensitive to orientation relative to gravitational forces, but invariant to grasp forcefulness.

Pesyna, Colin; Pundi, Krishna; Flanders, Martha

2011-01-01

215

Unusual two-dimensional sheet structure of the solvent-free cesium aryloxide complex CsO-2,6-i-Pr{sub 2}C{sub 6}H{sub 3}  

SciTech Connect

During recent investigations into the structure and reactivity of lanthanide aryloxide derivatives, the authors have isolated a number of salt or ate complexes of the stoichiometry M{prime}[Ln(OAr){sub 4}] (M{prime} = K{sup 7}, Cs{sup 8}) and Cs{sub 2}[La(OAr){sub 5}]{sup 9} (Ar = 2,6-i-Pr{sub 2}C{sub 6}H{sub 3}) in which the coordination sphere of the alkali metal cations consists exclusively of multihapto {eta}-arene interactions with aryloxide ligands from adjacent [Ln(OAr){sub 4}]{sup {minus}} or [Ln(OAr){sub 5}]2{sup 2{minus}} units. Following preparation and utilization of the parent alkali metal aryloxide complex Cs(O-2,6-i-Pr{sub 2}C{sub 6}H{sub 3}) during the synthesis of the lanthanum salts, the authors became aware of the dearth of structural data concerning heavy alkali metal aryloxide species. Although many complexes of both the lighter and heavier alkali metal aryloxides have been structurally characterized in which a crown ether is employed to encapsulate the cation, very few solvent-ligated or solvent-free aryloxide salts containing sodium, potassium, rubidium, or cesium have been subjected to X-ray diffraction studies. In the case of cesium, the authors have found only one example of a structurally characterized solvent-free aryloxide complex, namely cesium picrate Cs[O-2,4,6-(NO{sub 2}){sub 3}C{sub 6}H{sub 2}], which has been subjected to X-ray diffraction studies by two independent groups. In addition, very recent high-resolution powder X-ray diffraction data for cesium phenoxide (CsOPh) revealed a chain structure with both six-coordinate and three-coordinate metal ions and a very weak interaction between the cesium cation and an adjacent arene ring. Here, the authors report upon the unusual two-dimensional infinite-sheet structure of the solvent-free cesium aryloxide complex Cs(O-2,6-i-Pr{sub 2}C{sub 6}H{sub 3}). To the best of their knowledge, this work represents the first structural characterization of an alkyl-substituted solvent-free aryloxide complex of the heavier alkali metals.

Clark, D.L.; Click, D.R.; Hollis, R.V.; Scott, B.L.; Watkin, J.G. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.

1998-10-19

216

Dissolution of coal in solvents  

SciTech Connect

Experimental studies were effected in a 1-liter batch reactor to determine the role of the solvent and temperature on the dissolution of a Kentucky No. 9 coal. The goal was to increase the dissolution yield, defined as conversion of coal to pyridine-soluble material, while decreasing the hydrogen demand. The experiments were carried out in the absence of hydrogen gas. The solvent and coal were heated at a constant rate of temperature rise to 300 to 400/sup 0/C and held at a constant temperature for periods of 0 to 50 minutes before rapidly quenching the reaction mixture. 2-Methylnaphalene, 1,2,3,4-tetrahydronaphthalene (tetralin), p-cresol or ..beta..-naphthol, and ..gamma..-picoline were used in different ratios as the solvent. These compounds represented, respectively, the polycondensed aromatics, hydroaromatics (hydrogen donor), monophenols, and basic nitrogen compounds found in coal liquefaction recycle solvents. Dissolution yield of the coal reached a maximum in a solvent containing equal parts of 2-methylnaphthalene and tetralin. The H/C ratio of the preasphaltenes remained virtually constant when the tetralin content ranged from 20 to 65 wt % in mixtures with 2-methylnaphthalene. A slight increase was noted when pure tetralin was the solvent. Addition of small amounts of ..beta..-naphthol and ..gamma..-picoline to a 1:4 weight ratio of tetralin and 2-methylnaphthalene improved the dissolution yield. Coal was dissolved with no or minor chemical reactions up to the temperature of approx. 340/sup 0/C in a solvent containing 46.1 wt % tetralin, 46.1 wt % 2-methylnaphthalene, 4.9 wt % ..beta..-naphthol, and 2.9 wt % ..gamma..-picoline. Beyond this temperature dissolution yield increased exponentially typical of thermal cracking reactions.

Ebnesajjad, S.

1982-01-01

217

NCMS solvent substitution and material compatibility databases  

Microsoft Academic Search

The NCMS Solvent Database collects information on alternatives to ODC-based solvents used in electronics manufacturing. The database contains over 320 pure solvents and trade name mixtures. Each record includes 15 fields of environmental fate, 31 fields of health and safety, 21 fields of regulatory status, 36 fields of chemical\\/physical properties, and 19 fields of descriptive and supplier data. The Solvent

M. R. Wixom

1994-01-01

218

Coal liquefaction process with enhanced process solvent  

DOEpatents

In an improved coal liquefaction process, including a critical solvent deashing stage, high value product recovery is improved and enhanced process-derived solvent is provided by recycling second separator underflow in the critical solvent deashing stage to the coal slurry mix, for inclusion in the process solvent pool.

Givens, Edwin N. (Bethlehem, PA); Kang, Dohee (Macungie, PA)

1984-01-01

219

Coal liquefaction process with enhanced process solvent  

SciTech Connect

In an improved coal liquefaction process, including a critical solvent deashing stage, high value product recovery is improved and enhanced process-derived solvent is provided by recycling second separator underflow in the critical solvent deashing stage to the coal slurry mix, for inclusion in the process solvent pool.

Givens, E.N.; Kang, D.

1984-07-24

220

Gossip and Distributed Kalman Filtering: Weak Consensus Under Weak Detectability  

NASA Astrophysics Data System (ADS)

The paper presents the gossip interactive Kalman filter (GIKF) for distributed Kalman filtering for networked systems and sensor networks, where inter-sensor communication and observations occur at the same time-scale. The communication among sensors is random; each sensor occasionally exchanges its filtering state information with a neighbor depending on the availability of the appropriate network link. We show that under a weak distributed detectability condition: 1. the GIKF error process remains stochastically bounded, irrespective of the instability properties of the random process dynamics; and 2. the network achieves \\emph{weak consensus}, i.e., the conditional estimation error covariance at a (uniformly) randomly selected sensor converges in distribution to a unique invariant measure on the space of positive semi-definite matrices (independent of the initial state.) To prove these results, we interpret the filtered states (estimates and error covariances) at each node in the GIKF as stochastic particles with local interactions. We analyze the asymptotic properties of the error process by studying as a random dynamical system the associated switched (random) Riccati equation, the switching being dictated by a non-stationary Markov chain on the network graph.

Kar, Soummya; Moura, José M. F.

2011-04-01

221

DOE solvent handbook information sheet  

SciTech Connect

Solvents and cleaners are used in the Department of Defense (DOD) and the Department of Energy-Defense Program (DOE-DP) maintenance facilities for removing wax, grease, oil, carbon, machining fluids, solder fluxes, mold releases, and other contaminants before repairing or electroplating parts. Private industry also uses cleaners and degreasers for surface preparation of various metals. Growing environmental and worker safety concerns have brought attention to these solvents and cleaners, most of which are classified as toxic. Tightening government regulations have already excluded the use of some chemicals, and restrict the use of various halogenated hydrocarbons because of their atmospheric-ozone depleting effects, as well as their cancer-related risks. As a result, a program was established to develop an efficient, easily accessible, electronic solvent utilization handbook. This is being accomplished by: (1) identifying solvents (alternatives) that are not currently restricted by government regulations for use DOE-DP facilities, and private industry, (2) evaluating their cleaning performance, (3) evaluating their corrosivity, (4) evaluating their air emissions, (5) evaluating the possibility of recycling or recovering all or portions of the alternative degreasers, (6) testing substitute solvents compatibility with non-metallic materials, (7) inputting all of the data gathered (including previous biodegradability information) into a database, and (8) developing a methodology for efficient, widespread access to the data base information system.

Chavez, A.A.

1992-05-01

222

Weak quasielastic production of hyperons  

SciTech Connect

The quasielastic weak production of {lambda} and {sigma} hyperons from nucleons and nuclei induced by antineutrinos is studied in the energy region of some ongoing neutrino oscillation experiments in the intermediate energy region. The hyperon-nucleon transition form factors determined from neutrino-nucleon scattering and an analysis of high precision data on semileptonic decays of neutron and hyperons using SU(3) symmetry have been used. The nuclear effects due to Fermi motion and final state interaction effects due to hyperon-nucleon scattering have also been studied. The numerical results for differential and total cross sections have been presented.

Singh, S. K. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Department of Physics, Aligarh Muslim University, Aligarh- 202002 (India); Vacas, M. J. Vicente [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain)

2006-09-01

223

Electromagnetic weak turbulence theory revisited  

NASA Astrophysics Data System (ADS)

The statistical mechanical reformulation of weak turbulence theory for unmagnetized plasmas including fully electromagnetic effects was carried out by Yoon [Phys. Plasmas 13, 022302 (2006)]. However, the wave kinetic equation for the transverse wave ignores the nonlinear three-wave interaction that involves two transverse waves and a Langmuir wave, the incoherent analogue of the so-called Raman scattering process, which may account for the third and higher-harmonic plasma emissions. The present paper extends the previous formalism by including such a term.

Yoon, P. H.; Ziebell, L. F.; Gaelzer, R.; Pavan, J.

2012-10-01

224

Helpful hints for physical solvent absorption  

SciTech Connect

Review of experience with natural gas treatment using physical solvents points to design and operating suggestions. Experiences with three plants using either Selexol or Sepasolv MPE solvent shows that both solvents perform well. The solvents offer economical and problem-free purification of natural gas. The Sepasolv MPE and Selexol solvents are very similar in chemical structure and physical properties. Thus, their application range is almost similar. An exchange is possible in most plants without equipment modification and/or process data.

Wolfer, W.

1982-11-01

225

Spectral characteristics of tramadol in different solvents and ?-cyclodextrin  

NASA Astrophysics Data System (ADS)

Effect of solvents and ?-cyclodextrin on the absorption and fluorescence spectra of tramadol drug has been investigated and compared with anisole. The solid inclusion complex of tramadol with ?-CD is investigated by FT-IR, 1H NMR, scanning electron microscope (SEM), DSC and semiempirical methods. The thermodynamic parameter (? G) of inclusion process is determined. A solvent study shows (i) the spectral behaviour of both tramadol and anisole molecules is similar to each other and (ii) the cyclohexanol group in tramadol is not effectively conjugated with anisole group. However, in ?-CD, due to space restriction of the CD cavity, a weak interaction is present between the above groups in tramadol. ?-Cyclodextrin studies show that tramadol forms 1:2 inclusion complex with ?-CD. A mechanism is proposed for the inclusion process.

Anton Smith, A.; Manavalan, R.; Kannan, K.; Rajendiran, N.

2009-10-01

226

Genetic susceptibility in solvent induced neurobehavioral effects.  

PubMed

The aim of this investigation was to study the influence of genetic polymorphisms of biotransformation enzymes and dopamine receptors on neurobehavioral effects in referents (n = 53), solvent-workers (n = 144), and chronic toxic encephalopathy (CTE) patients (n = 33). All participants were interviewed for exposure data and confounding factors and underwent a clinical examination. Neurobehavioral complaints (neurotoxicity symptom checklist-60) and effects [simple reaction time (SRT), symbol digit substitution (SDS), hand-eye coordination (HEC), and digit span backwards (DSB)] were evaluated with a computer assisted test battery. The following genotypes were determined: GSTM1, GSTT1, GSTP1, DRD2 Taq1A, DRD2 Taq1B, and DRD2-141Cdel. Neurotoxic effects and complaints were significantly higher in CTE patients and were related to both duration and level of exposure. An equal distribution of genotypes was found between all groups. Logistic regression analysis revealed that GSTT1 was negatively associated with sleep and sensorimotor complaints. GSTM1 had a protecting influence on the relationship between logDSB and the cumulative exposure index and between logSRT and cumulative exposure index and degree of exposure, respectively. This effect was also found when correcting for age, education level, alcohol consumption, and smoking. DRD2-141Cdel polymorphisms had a negative influence on the relationship between logSDS and the total exposure time. GSTT1 might be protective against sleep and sensorimotor complaints, whereas GSTM1 seems to decrease sustained attention and short-term memory problems in relation to solvent exposure. Individuals possessing DRD2-141Cdel variant experienced more visuomotor problems. PMID:19701675

Godderis, L; Maertens, N; de Gelder, V; De Lamper, A; De Ruyck, K; Vernimmen, M; Bulterys, S; Moens, G; Thierens, H; Viaene, M K

2009-08-22

227

General Coordinates Game  

NSDL National Science Digital Library

This interactive Java applet allows users to plot a "house" on a -10 by 10 coordinate plane. A "view" mode allows users to enter an ordered pair and move the house to that location. The "guess" mode randomly plots the house on the plane and the user must enter the ordered pair for its location. An optional scoring feature allows users to keep track of the number correct.

2005-01-01

228

Solvent-regenerated activated carbon  

SciTech Connect

This report summarizes the results of a University/Industry research project, sponsored by the New York State Energy Research and Development Authority and Fluids Design Corporation. The research project studied the solvent regeneration of activated carbon. Activate carbon was used to remove trace organics from aqueous streams, then regenerated by desorbing the adsorbates with organic solvents. The project included a survey of the potential applications in New York State industries, fundamental research on the adsorption/desorption phenomena, and design of a full-scale process. The economics of the full-scale process were evaluated and compared to alternate available technologies. The result of this work is a versatile process with attractive economics. A wide range of adsorbates and solvents were found to be acceptable for this process. The design methodologies are developed and the techniques for evaluating a new application are delineated. 13 refs., 12 figs., 4 tabs.

McLaughlin, H. (Fluids Design Corp., Troy, NY (USA))

1988-07-01

229

Combined thermal and solvent stimulation  

SciTech Connect

This invention provides a method for recovering heavy crude oil from an underground reservoir penetrated by a well, which comprises (a) heating the reservoir surrounding the wellbore with steam at a temperature below coking temperature but sufficient to increase the temperature 40/sup 0/-200/sup 0/ F. above the reservoir temperature; (b) producing the formation until most of the injected water is produced; (c) injecting a liquid solvent having a ratio of crude viscosity to solvent viscosity of at least about 10 and in an amount ranging from about 5 to about 25 barrels per foot of oil-bearing formation; (d) producing a solvent-crude mixture; and (e) repeating steps (c) and (d).

McMillen, J. M.

1985-05-28

230

Hipparchus' coordinate system  

NASA Astrophysics Data System (ADS)

In his "Histoire de l'Astronomie Ancienne" Delambre concludes unequivocally that Hipparchus knew and used a definite system of celestial spherical coordinates, namely the right ascension and declination system that we use today. The basis of Delambre's conclusion was disarmingly simple: he pointed out that in the "Commentary to Aratus" Hipparchus actually quotes the positions of numerous stars directly in right ascension and declination (or more often its complement, polar distance). Nearly two centuries later, in his "A History of Ancient Mathematical Astronomy", Neugebauer not only completely ignores Delambre's conclusion on this issue, but goes further to propose his own, as we shall see quite fanciful, theory that begins "From the Commentary to Aratus, it is quite obvious that at Hipparchus' time a definite system of spherical coordinates for stellar positions did not yet exist." and concludes "...nowhere in Greek astronomy before the catalogue of stars in the Almagest is it attested that orthogonal spherical coordinates are used to determine stellar positions." Today it is clear that Neugebauer's theory is conventionally accepted. It is the purpose of this paper to offer fresh arguments that Delambre was correct.

Duke, Dennis W.

2002-07-01

231

Universal mechatronics coordinator  

NASA Astrophysics Data System (ADS)

Mechatronic systems incorporate multiple actuators and sensor which must be properly coordinated to achieve the desired system functionality. Many mechatronic systems are designed as one-of-a-kind custom projects without consideration for facilitating future system or alterations and extensions to the current syste. Thus, subsequent changes to the system are slow, different, and costly. It has become apparent that manufacturing processes, and thus the mechatronics which embody them, need to be agile in order to more quickly and easily respond to changing customer demands or market pressures. To achieve agility, both the hardware and software of the system need to be designed such that the creation of new system and the alteration and extension of current system is fast and easy. This paper describes the design of a Universal Mechatronics Coordinator (UMC) which facilitates agile setup and changeover of coordination software for mechatronic systems. The UMC is capable of sequencing continuous and discrete actions that are programmed as stimulus-response pairs, as state machines, or a combination of the two. It facilitates the modular, reusable programing of continuous actions such as servo control algorithms, data collection code, and safety checking routines; and discrete actions such as reporting achieved states, and turning on/off binary devices. The UMC has been applied to the control of a z- theta assembly robot for the Minifactory project and is applicable to a spectrum of widely differing mechatronic systems.

Muir, Patrick F.

1999-11-01

232

Weak gravitational lensing with DEIMOS  

NASA Astrophysics Data System (ADS)

We introduce a novel method for weak-lensing measurements, which is based on a mathematically exact deconvolution of the moments of the apparent brightness distribution of galaxies from the telescope's point spread function (PSF). No assumptions on the shape of the galaxy or the PSF are made. The (de)convolution equations are exact for unweighted moments only, while in practice a compact weight function needs to be applied to the noisy images to ensure that the moment measurement yields significant results. We employ a Gaussian weight function, whose centroid and ellipticity are iteratively adjusted to match the corresponding quantities of the source. The change of the moments caused by the application of the weight function can then be corrected by considering higher order weighted moments of the same source. Because of the form of the deconvolution equations, even an incomplete weighting correction leads to an excellent shear estimation if galaxies and PSF are measured with a weight function of identical size. We demonstrate the accuracy and capabilities of this new method in the context of weak gravitational lensing measurements with a set of specialized tests and show its competitive performance on the GREAT08 Challenge data. A complete C++ implementation of the method can be requested from the authors.

Melchior, P.; Viola, M.; Schäfer, B. M.; Bartelmann, M.

2011-04-01

233

Early Intervention Service Coordination Models and Service Coordinator Practices  

Microsoft Academic Search

The relationship between three different service coordinator models (dedicated and independent, dedicated but not independent, and blended) and the use of nine different service coordinator practices was examined in a study of families of infants and toddlers enrolled in the IDEA Part C early intervention program. Results showed that service coordinators provided children and families fewer services when using a

Carl J. Dunst; Mary Beth Bruder

2006-01-01

234

Coordination Variables, Coordination Functions, and Cooperative Timing Missions  

Microsoft Academic Search

This paper presents a solution strategy for achieving cooperative timing among teams of vehicles. Based on the notion of coordination variables and coordination functions, the strategy facilitates cooperative timing by requiring acceptably low levels of communication and computation. The application of the coordination variable\\/function approach to trajectory planning problems for teams of unmanned air vehicles with timing constraints is described.

Timothy W. McLain; Randal W. Beard

2003-01-01

235

Solvent extraction of Cu(I) from waste etch chloride solution using tri-butyl phosphate (TBP) diluted in 1-octanol  

Microsoft Academic Search

Cuprous ion has wide applications in various industries due to its properties to form stable coordination compound of high solubility with different ligands. Compared to extensive R&D work on solvent extraction of cupric ion, the limited work is reported on cuprous ion extraction using organic extractant. Therefore, in the present work, solvent extraction studies have been carried out for the

J.-c. Lee; T. Zhu; M. K. Jha; S.-k. Kim; K.-k. Yoo; J. Jeong

2008-01-01

236

Thermodynamics of polymer-supercritical solvent mixtures  

NASA Astrophysics Data System (ADS)

The objectives of this research are to experimentally investigate the high pressure fluid phase behavior of polymer solutions and to characterize the resultant phase behavior using contemporary polymer solution theories. The polymer solutions of interest are of three types: (1) a binary mixture of polymer and organic solvent; (2) a binary mixture of polymer and supercritical fluid (SCF) solvent; and (3) a ternary mixture of polymer, organic solvent, and SCF solvent. There are three goals of the experimental phase of this project. The first goal is to determine the effect of high pressure on the lower critical solution temperature (LCST) of the polymer-organic solvent mixture at conditions close to the critical point of the organic solvent. The second goal is to study the phase behavior of polymer - SCF solvent mixtures. The final experimental goal is to study the high pressure phase behavior of tenary mixtures consisting of a polymer, an organic solvent, and an SCF solvent.

McHugh, M. A.

1985-07-01

237

Service Coordination: The School Counselor.  

ERIC Educational Resources Information Center

|Discusses how counselors can successfully execute the responsibilities of a service coordinator to enhance counseling effectiveness. Describes three phases of service coordination: information retrieval, information assessment, and information administration. (RC)|

DeVoe, Marianne W.; McClam, Tricia

1982-01-01

238

Statistical theory of electromagnetic weak turbulence  

SciTech Connect

The weak turbulence theory as commonly found in the literature employs electrostatic approximation and is applicable to unmagnetized plasmas only. To this date, fully electromagnetic generalization of the existing weak turbulence theory based upon statistical mechanical approach remains largely incomplete. Instead, electromagnetic effects are incorporated into the weak turbulence formalism by means of the semiclassical approach. The present paper reformulates the fully electromagnetic weak turbulence theory from classical statistical mechanical (i.e., the Klimontovich) approach.

Yoon, Peter H. [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742-2431 (United States)

2006-02-15

239

Weak Links as Stabilizers of Complex Systems  

NASA Astrophysics Data System (ADS)

In the previous chapters we learned how weak links stabilize complex systems. The classical study of Granovetter (1973) demonstrated that weak links help the cohesion of society (see Chap. 1). Weak links are necessary for small-worldness, emerging in parallel with topological scale-freeness, and making a key contribution to the formation of nestedness (see Chap. 2). Weak links buffer noise, help relaxation, form barriers against cascading failures, and stabilize the coupled oscillators of bottom networks (see Chap. 3).

Csermely, Peter

240

Coordinate conditions from variational principles  

Microsoft Academic Search

Summary  Co-ordinate conditions arising from the requirement of yielding a metric tensor which is best approximation to a Minkowski\\u000a metric tensor are obtained and are applied to several spaces. Another set of co-ordinate conditions are derived by considering\\u000a the co-ordinates to be comoving co-ordinates of a fictitious fluid and finding those co-ordinate systems having minimum total\\u000a intrinsic rotation. It is found

A. A. Evett

1962-01-01

241

Solvent Refined Coal (SRC) Process.  

National Technical Information Service (NTIS)

These monthly reports trace the progress of the Solvent Refined Coal (SRC) process developed by The Pittsburg and Midway Coal Mining Co. under contract to the Office of Coal Research since 1966. The process will undergo testing in a pilot plant recently c...

1970-01-01

242

Physical solvent for gas sweetening  

SciTech Connect

This invention relates to a novel solvent, N-2-methoxyethyl-2-pyrrolidone, that can be used in two ways. First, in the pure or undiluted form, it absorbs hydrogen sulfide and other sulfurous gases selectively and simultaneously dries the gas. Second, when mixed with an alkanolamine and water, it is a superior absorbent of mercaptans, sulfides, and disulfides, and removes acid gases.

Ferrin, C. R.; Manning, W. P.

1984-11-27

243

Solvent Refined Coal (SRC) Process.  

National Technical Information Service (NTIS)

These monthly reports trace the progress of the Solvent Refined Coal (SRC) process developed by The Pittsburg and Midway Coal Mining Co. under contract to the Office of Coal Research since 1966. The process will undergo testing in a pilot plant recently c...

1971-01-01

244

Solvent Refined Coal (SRC) Process.  

National Technical Information Service (NTIS)

These monthly reports trace the progress of the Solvent Refined Coal (SRC) process developed by The Pittsburg and Midway Coal Mining Co. under contract to the Office of Coal Research since 1966. The process will undergo testing in a pilot plant recently c...

1972-01-01

245

Solvent Refined Coal (SRC) Process.  

National Technical Information Service (NTIS)

These monthly reports trace the progress of the Solvent Refined Coal (SRC) process developed by The Pittsburg and Midway Coal Mining Co. under contract to the Office of Coal Research since 1966. The process will undergo testing in a pilot plant recently c...

1973-01-01

246

Improved Purex solvent scrubbing methods  

SciTech Connect

Studies of hydrazine and hydroxylamine salts as solvent scrubbing agents that can be decomposed into gases are summarized. Results from testing of countercurrent scrubbers and solid sorber columns that produce lesser amounts of permanent salts are reported. The status of studies of the acid-degradation of paraffin diluent and the options for removal of long-chain organic acids is given.

Mailen, J.C.; Tallent, O.K.

1984-01-01

247

Progressive leg pain and weakness.  

PubMed

A 54-year-old man presented with progressive asymmetric leg pain and weakness. He had a history of invasive squamous cell carcinoma that was fully treated 2 years earlier. His leg symptoms progressed relentlessly during several months. Imaging studies demonstrated enhancement of the cauda equina and leptomeninges of the lower spinal cord. Initial cerebrospinal fluid examination showed an elevated protein concentration and lymphocytic pleocytosis with no malignant cells on cytological analysis. There was short-term improvement in symptoms and cerebrospinal fluid abnormalities with intravenous steroids. Two additional cerebrospinal fluid studies showed normal cytological findings, elevated IgG synthesis, and elevated antibody titers to varicella-zoster virus. Over time, the patient worsened, developed cranial neuropathies, and ultimately died. The pathological diagnosis and the approach to the clinical data are discussed. PMID:23440264

Navalkele, Digvijaya D; Georgescu, Maria-Magdalena; Burns, Dennis K; Greenberg, Tasha; Vernino, Steven

2013-04-01

248

Weakly nonlinear magnetohydrodynamic wave interactions  

SciTech Connect

Equations describing weakly nonlinear magnetohydrodynamic (MHD) wave interactions in one Cartesian space dimension are discussed. For wave propagation in uniform media, the wave interactions of interest consist of: (a) three-wave resonant interactions in which high frequency waves, may evolve on long space and time scales if the wave phases satisfy the resonance conditions; (b) Burgers self-wave steepening for the magnetoacoustic waves, and (c) mean wave field effects, in which a particular wave interacts with the mean wave field of the other waves. For wave propagation in non-uniform media, further linear wave mixing terms appear in the equations. The equations describe four types of resonant triads: slow-fast magnetosonic wave interaction; Alfv{acute e}n-entropy wave interaction; Alfv{acute e}n-magnetosonic wave interaction; and magnetosonic-entropy wave interaction. The formalism is restricted to coherent wave interactions. {copyright} {ital 1999 American Institute of Physics.}

Webb, G.M. [Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721 (United States); Brio, M.; Kruse, M.T. [Department of Mathematics, University of Arizona, Tucson, Arizona 85721 (United States); Zank, G.P. [Bartol Research Institute, University of Delaware, Newark, Delaware 19716 (United States)

1999-06-01

249

Weak scale radiative lepton mass  

NASA Astrophysics Data System (ADS)

We construct a Z8 model for leptons where all Yukawa couplings are of order unity, but known lepton masses are generated radiatively, order by order. The seed is provided by fourth generation leptons E and N, and two additional Higgs doublets are introduced to give nearest-neighbor Yukawa couplings. Loop masses are generated when Z8 is softly broken down to Z2, while me and m? generation require Higgs bosons to be weak scale. The Z2 symmetry forbids ?-->e?. The most stringent bound comes from ?-->??+/-e-/+. The model has implications for ?-->e?, ?e¯-->?¯e conversion, ?-->e?e?¯?, and FCNC decays of E and N (such as E-->?e+/-?-/+).

Wong, Gwo-Guang; Hou, Wei-Shu

1994-09-01

250

An Empirical Evaluation of Weak Mutation  

Microsoft Academic Search

Mutation testing is a fault-based technique for unit level software testing. Weak mutation was proposed as a way to reduce the expense of mutation testing. Unfortunately, weak mutation is also expected to provide a weaker test of the software than mutation testing does. This paper presents results from an implementation of weak mutation, which we used to evaluate the effectiveness

A. Jefferson Offutt; Stephen D. Lee

1994-01-01

251

Acidizing with chemically heated weak acid  

SciTech Connect

Materials in and around a well are acidized with chemically heated, hot acid by injecting a solution of both nitrogen and heat generating reactants and a mixture of weak acid and weak acid salt that both buffers the relation and provides a weak acid acidizing solution.

Richardson, E. A.

1984-11-13

252

Generalized parallel heat transport equations in collisional to weakly collisional plasmas  

Microsoft Academic Search

A new set of two-fluid heat-transport equations for heat conduction in collisional to weakly collisional plasmas was derived on the basis of gyrokinetic equations in flux coordinates. In these equations, no restrictions on the anisotropy of the ion distribution function or the collisionality are imposed. In the highly collisional limit, these equations reduce to the classical heat conduction equation of

Emad Zawaideh; N. S. Kim; Farrokh Najmabadi

1988-01-01

253

Solid-state reactivity and structural transformations involving coordination polymers.  

PubMed

This tutorial review discusses recent literature on coordination polymers and metal-organic frameworks (MOFs) that exhibit solid-state reactivity and structural transformation under various experimental conditions. Removal or exchange of solvents and guest molecules, exposure to reactive vapours, and external stimuli such as heat, light or mechanochemical force cause such structural transformations and these are often manifested by various physical properties such as colour, magnetism, luminescence, chirality, porosity, etc. due to change in coordination number and geometry, dimensionality, interpenetration, etc. More drastic transformations related to the exchange of metal ions, pillar ligands and insertion of additional ligands between the layers have also been demonstrated. The vast area of dynamic behaviour of coordination polymers and their stimuli-responsive properties have also been addressed briefly. PMID:23034597

Kole, Goutam Kumar; Vittal, Jagadese J

2012-10-03

254

Coordination in Mobile Agent Applications  

Microsoft Academic Search

The paper addresses the issue of coordination in distributed app lications based on mobile agents. The presence of mobile active computational entities makes traditional coordination models based on message-passing, such a s the c lient-server one, not effective, from both the performance and the usability points of view. Indirect coordination models suit better the mobile scenario: interactions occur via blackboards

Giacomo Cabri; Letizia Leonardi; Franco Zambonelli

1997-01-01

255

Understanding Leadership A Coordination Theory  

Microsoft Academic Search

Important aspects of leadership behavior can be rendered intelligible through a focus on coordination games. The concept of common knowledge is shown to be particularly important to understanding leadership. Thus, leaders may establish common knowledge conditions and assist the coordination of strategies in this way, or make decisions in situations where coordination problems persist in spite of common knowledge.

Nicolai J. Foss

1999-01-01

256

Supporting coordination in CSCW systems  

Microsoft Academic Search

A method for defining coordination in computer-supported cooperative work (CSCW) systems is presented. General coordination semantics defined in terms of speech acts and general modules that can implement such semantics are described. The general objects achieve flexibility by separating coordination knowledge into its local and global components and distributing this knowledge among system objects. Objects are classified as ports, links,

I. T. Hawryszkiewycz

1993-01-01

257

Incremental coordination in collaborative networks  

Microsoft Academic Search

We developed an incremental coordination technique for collaborative networks based on necessary and sufficient coordinability conditions that we proposed earlier for locally controlled hierarchies of dynamic systems. Efficiency of the technique is illustrated by mathematical modelling of a two-level control system for a network of linear objects. The modelling has proved that usage of local control and coordination widens the

Alexander Fridman; Olga Fridman

2010-01-01

258

Nitromethane as solvent in capillary electrophoresis.  

PubMed

Nitromethane has several properties that make it an interesting solvent for capillary electrophoresis especially for lipophilic analytes that are not sufficiently soluble in water: freezing and boiling points are suitable for laboratory conditions, low viscosity leads to favourable electrophoretic mobilities, or an intermediate dielectric constant enables dissolution of electrolytes. In the present work we investigate the change of electrophoretically relevant analyte properties - mobilities and pKa values - in nitromethane in dependence on the most important experimental conditions determined by the background electrolyte: the ionic strength, I, and the pH. It was found that the mobility decreases with increasing ionic strength (by, e.g. up to 30% from I = 0 to 50 mmol/L) according to theory. An appropriate pH scale is established by the aid of applying different concentration ratios of a buffer acid with known pKa and its conjugate base. The mobility of the anionic analytes (from weak neutral acids) depends on the pH with the typical sigmoidal curve in accordance with theory. The pKa of neutral acids derived from these curves is shifted by as much as 14 pK units in nitromethane compared to water. Both findings confirm the agreement of the electrophoretic behaviour of the analytes with theories of electrolyte solutions. Separation of several neutral analytes was demonstrated upon formation of charged complexes due to heteroconjugation with chloride as ionic constituent of the background electrolyte. PMID:16038311

Subirats, Xavier; Porras, Simo P; Rosés, Martí; Kenndler, Ernst

2005-06-24

259

The geometry and significance of weak energy  

NASA Astrophysics Data System (ADS)

The theory of weak values for quantum mechanical observables has come to serve as a useful basis for contemporary discussions concerning such varied topics as the tunnelling-time controversy and quantum stochastic processes. An intrinsic complex-valued weak energy has recently been observed experimentally and reported in the literature. In this paper it is shown that: (a) the real and imaginary valued parts of this weak energy have geometric interpretations related to a phase acquired from parallel transport in Hilbert space and the variational dynamics occurring in the associated projective Hilbert space, respectively; (b) the weak energy defines functions which translate correlation amplitudes and probabilities in time; (c) correlation probabilities can be controlled by manipulating the weak energy and there exists a condition of weak stationarity that guarantees their time invariance; and (d) a time-weak energy uncertainty relation of the usual form prevails when a suitable set of dynamical constraints are imposed.

Parks, A. D.

2000-04-01

260

Weak intermolecular interactions in gas-phase nuclear magnetic resonance.  

PubMed

Gas-phase nuclear magnetic resonance (NMR) spectra demonstrating the effect of weak intermolecular forces on the NMR shielding constants of the interacting species are reported. We analyse the interaction of the molecular hydrogen isotopomers with He, Ne, and Ar, and the interaction in the He-CO(2) dimer. The same effects are studied for all these systems in the ab initio calculations. The comparison of the experimental and computed shielding constants is shown to depend strongly on the treatment of the bulk susceptibility effects, which determine in practice the pressure dependence of the experimental values. Best agreement of the results is obtained when the bulk susceptibility correction in rare gas solvents is evaluated from the analysis of the He-rare gas interactions, and when the shielding of deuterium in D(2)-rare gas systems is considered. PMID:21895188

Garbacz, Piotr; Piszczatowski, Konrad; Jackowski, Karol; Moszynski, Robert; Jaszu?ski, Micha?

2011-08-28

261

A Universe without Weak Interactions  

SciTech Connect

A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe.

Harnik, Roni; Kribs, Graham D.; Perez, Gilad

2006-04-07

262

A universe without weak interactions  

SciTech Connect

A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''weakless universe'' is matched to our Universe by simultaneously adjusting standard model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the weakless universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multiparameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe.

Harnik, Roni [Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States); Physics Department, Stanford University, Stanford, California 94305 (United States); Kribs, Graham D. [Department of Physics and Institute of Theoretical Science, University of Oregon, Eugene, Oregon 97403 (United States); Perez, Gilad [Theoretical Physics Group, Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)

2006-08-01

263

Combustion of solvent refined coal  

SciTech Connect

Successful laboratory study of Solvent Refined Coal, both solid (SRC I) and liquid fuel oil (SRC II), led into full-scale utility boiler tests with the intent of demonstrating the suitability of solvent refined coal as a potential utility boiler fuel. In general, no major operational problems or adverse boiler performance effects were encountered due to the combustion of SRC. No equipment problems were experienced with either Babcock and Wilcox's Type E pulverizers or water-cooled dual register burners during the SRC I combustion tests. Some differences were noted between coal and SRC I with respect to the combustion efficiency and heat absorption patterns within the boiler. Both SO/sub 2/ and NOx emissions were within EPA limits.

Ghassemzadeh, M.R.

1983-01-01

264

Firing of pulverized solvent refined coal  

DOEpatents

An air-purged burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired without the coking thereof on the burner components. The air-purged burner is designed for the firing of pulverized solvent refined coal in a tangentially fired boiler.

Derbidge, T. Craig (Sunnyvale, CA); Mulholland, James A. (Chapel Hill, NC); Foster, Edward P. (Macungie, PA)

1986-01-01

265

Solvent radical mediated hydrogenolysis in coal liquefaction  

SciTech Connect

In the conventional model for coal liquefaction the role of the solvents is merely to stabilize radicals generated by thermolysis of coal structures. We have previously presented a model in which the solvent radicals play an active part in engendering bond scission by transferring hydrogen to ipso postions. In this paper we present experimental evidence in support of solvent radical mediated hydrogenolysis. 9 refs.

McMillen, D.F.; Malhotra, R.; Chang, S.J.; Nigenda, S.E.

1985-01-01

266

Reduction of solvent use through fluxless soldering  

Microsoft Academic Search

Conventional soldering typically requires fluxing to promote wetting. Halogenated solvents must then be used to remove the flux residues. While such practice has been routinely accepted throughout the DOE weapons complex, new environmental laws and agreements will eventually phaseout the use of these solvents. Solvent substitution or alternative technologies must be developed to meet these restrictions. SNL, Albuquerque is characterizing

Hosking

1990-01-01

267

Solvent pretreatment of feed coal for briquetting  

SciTech Connect

Solvent pretreating of coal fines prior to briquetting results in coal briquettes which have no added binder and which will withstand weathering conditions better than binder containing briquettes. The solvents are generally described as organic Lewis base solvents which are capable of electron donor action, and include among others, acetone, methyl ethyl ketone, and ethylene diamine.

Martin, D.M.; Miller, M.R.

1980-11-25

268

Solvent substitution for electronic products  

Microsoft Academic Search

Allied-Signal Inc., Kansas City Division (KCD), manufactures the electrical, electrochemical, mechanical, and plastic components for nuclear weapons. The KCD has made a commitment to eliminate the use of chlorohydrocarbon (CHC) and chlorofluorocarbon (CFC) solvents to the greatest technical extent possible consistent with nuclear safety and stockpile reliability requirements. Current cleaning processes in the production departments use trichloroethylene, 1,1,1-trichloroethane, and various

Benkovich

1992-01-01

269

Atomistic simulation based prediction of the solvent effect on the molecular mobility and glass transition of poly (methyl methacrylate)  

NASA Astrophysics Data System (ADS)

We present an investigation of the retained solvent effect on the glass transition temperature (Tg) of poly(methyl methacrylate) (PMMA) through all-atom molecular dynamics simulations. Addition of a weakly interactive solvent, tetrahydrofuran (THF), causes a depression of the PMMA Tg that can be identified through an analysis of the mean squared displacement of the polymer chains from atomistic trajectories. Our results are in very good agreement with an atomistically informed theoretical model based on free volume theory and demonstrate the applicability of molecular simulation to discern solvent effects on polymer thermomechanical behavior in silico.

Mishra, Shawn; Keten, Sinan

2013-01-01

270

Solvent cleaning system and method for removing contaminants from solvent used in resin recycling  

DOEpatents

A two step solvent and carbon dioxide based system that produces essentially contaminant-free synthetic resin material and which further includes a solvent cleaning system for periodically removing the contaminants from the solvent so that the solvent can be reused and the contaminants can be collected and safely discarded in an environmentally safe manner.

Bohnert, George W. (Harrisonville, MO); Hand, Thomas E. (Lee' s Summit, MO); DeLaurentiis, Gary M. (Jamestown, CA)

2009-01-06

271

The "Weak Asperity" Alternative (Invited)  

NASA Astrophysics Data System (ADS)

In the study of friction in engineering and material science, asperities are micrometer-scale protuberances and are stronger areas of frictional contacts. Scaling them up to natural faults has enabled us to explain seismic rupture but has also led to difficulties in explaining general fault-zone processes. For seismic slip zones, which are typically a few mm to cm thick and can be approximated as frictional contacts, the concept of strong asperity appears to apply. The micro-scale asperities, and the associated critical slip distances, can explain velocity weakening and other dynamic weakening processes. If subduction faults were continuous frictional contacts, we would expect the same concept to apply also to much large scales, with strong seismic asperities surrounded by weak aseismic zones. However, just like the numerous large strike-slip faults we observe on land, subduction faults are zones of complex 3D internal structure, as is seen in exhumed ancient subduction zones. Even a casual inspection of seafloor morphology can tell that the complexity of the fault zone must be strongly, or mainly, influenced by the ruggedness of the subducting seafloor. Greater topographic reliefs subduct against greater resistance, but the resistance is not always "frictional". During subduction, geometrical irregularities of the fault zone are smoothed by wear and sediment fill but can also be generated by off-fault fracturing and renewed by newly subducted uneven seafloor. Smooth areas with more uniform mechanical properties will localize shear and develop continuous thin contact zones, obeying rate-state friction and allowing seismic rupture to propagate. Rougher areas will experience more heterogeneous deformation involving fracture, shear, and rotation of wall rocks, a process responsible for the formation of a broader damage zone. The roughest parts, such as subducting seamounts, move by developing a fracture system around them. The rougher parts are stronger and, unlike micro-scale asperities, they induce pervasive off-fault deformation via small-scale faulting, cataclasis, and/or pressure solution. Their broad deformation zone shears aseismically to accommodate plate motion and often generates small or medium-size earthquakes, exhibiting a rich variety of seismic behaviour. Their general lack of slip-zone continuity often causes them to act as barriers for great earthquakes. In comparison, the stick-slip zones in the smoother areas of the plate interface are weaker. According to this "weak asperity" model, the location, size, and frequency of subduction earthquakes are to the first order controlled by the structural evolution of the fault zone, which in turn is controlled primarily by the ruggedness of the incoming seafloor and the amount of trench sediments. This view is consistent with a global correlation of earthquake size with incoming-seafloor roughness at subduction zones.

Wang, K.

2010-12-01

272

Powerful signals for weak muscles.  

PubMed

The aim of the present review is to summarise, evaluate and critique the different mechanisms involved in anabolic growth of skeletal muscle and the catabolic processes involved in cancer cachexia and sarcopenia of ageing. This is highly relevant, since they represent targets for future promising clinical investigations. Sarcopenia is an inevitable process associated with a gradual reduction in muscle mass and strength, associated with a reduction in motor unit number and atrophy of muscle fibres, especially the fast type IIa fibres. The loss of muscle mass with ageing is clinically important because it leads to diminished functional ability and associated complications. Cachexia is widely recognised as severe and rapid wasting accompanying disease states such as cancer or immunodeficiency disease. One of the main characteristics of cancer cachexia is asthenia or lack of strength, which is directly related to the muscle loss. Indeed, apart from the speed of loss, muscle wasting during cancer and ageing share many common metabolic pathways and mediators. In healthy young individuals, muscles maintain their mass and function because of a balance between protein synthesis and protein degradation associated with rates of anabolic and catabolic processes, respectively. Muscles grow (hypertrophy) when protein synthesis exceeds protein degradation. Conversely, muscles shrink (atrophy) when protein degradation dominates. These processes are not occurring independently of each other, but are finely coordinated by a web of intricate signalling networks. Such signalling networks are in charge of executing environmental and cellular cues that ultimately determine whether muscle proteins are synthesised or degraded. Increasing our understanding for the pathways involved in hypertrophy and atrophy and particularly the interaction of these pathways is essential in designing therapeutic strategies for both prevention and treatment of muscle wasting conditions with age and with disease. PMID:19716529

Saini, Amarjit; Faulkner, Steve; Al-Shanti, Nasser; Stewart, Claire

2009-02-20

273

Scattering points in parallel coordinates.  

PubMed

In this paper, we present a novel parallel coordinates design integrated with points (Scattering Points in Parallel Coordinates, SPPC), by taking advantage of both parallel coordinates and scatterplots. Different from most multiple views visualization frameworks involving parallel coordinates where each visualization type occupies an individual window, we convert two selected neighboring coordinate axes into a scatterplot directly. Multidimensional scaling is adopted to allow converting multiple axes into a single subplot. The transition between two visual types is designed in a seamless way. In our work, a series of interaction tools has been developed. Uniform brushing functionality is implemented to allow the user to perform data selection on both points and parallel coordinate polylines without explicitly switching tools. A GPU accelerated Dimensional Incremental Multidimensional Scaling (DIMDS) has been developed to significantly improve the system performance. Our case study shows that our scheme is more efficient than traditional multi-view methods in performing visual analysis tasks. PMID:19834165

Yuan, Xiaoru; Guo, Peihong; Xiao, He; Zhou, Hong; Qu, Huamin

274

Focused SWOT: diagnosing critical strengths and weaknesses  

Microsoft Academic Search

Despite the problems involved in its use, SWOT (strengths-weaknesses-opportunities-threats) analysis remains a major strategic tool for listing the strengths and weaknesses of an organisation, for recording the major strengths and translating them into value. This paper presents a straightforward methodology for making a structured analysis of strengths and weaknesses, based on an analysis of important value-creating events and the strengths

Alex Coman; Boaz Ronen

2009-01-01

275

Weak interactions between folate and osmolytes in solution.  

PubMed

Previous osmotic stress studies on the role of solvent in two structurally unrelated dihydrofolate reductases (DHFRs) found weaker binding of dihydrofolate (DHF) to either enzyme in the presence of osmolytes. To explain these unusual results, weak interactions between DHF and osmolytes were proposed, with a competition between osmolyte and DHFR for DHF. High osmolyte concentrations will inhibit binding of the cognate pair. To evaluate this hypothesis, we devised a small molecule approach. Dimerization of folate, monitored by nuclear magnetic resonance, was weakened 2-3-fold upon addition of betaine or dimethyl sulfoxide (DMSO), supporting preferential interaction of either osmolyte with the monomer (as it possesses a larger surface area). Nuclear Overhauser effect (NOE) spectroscopy experiments found a positive NOE for the interaction of the C3'/C5' benzoyl ring protons with the C9 proton in buffer; however, a negative NOE was observed upon addition of betaine or DMSO. This change indicated a decreased tumbling rate, consistent with osmolyte interaction. Osmotic stress experiments also showed that betaine, DMSO, and sucrose preferentially interact with folate. Further, studies with the folate fragments, p-aminobenzoic acid and pterin 6-carboxylate, revealed interactions for both model compounds with betaine and sucrose. In contrast, DMSO was strongly excluded from the pterin ring but preferentially interacted with the p-aminobenzoyl moiety. These interactions are likely to be important in vivo because of the crowded conditions of the cell where weak contacts can more readily compete with specific binding interactions. PMID:22369433

Duff, Michael R; Grubbs, Jordan; Serpersu, Engin; Howell, Elizabeth E

2012-03-09

276

Foaming properties of solvents for use in air-assisted solvent extraction  

Microsoft Academic Search

The air-assisted solvent extraction (AASX) concept uses a solvent-coated bubble to contact the organic and aqueous phases. Compared to conventional solvent extraction, a high contact area can be created using less solvent and the buoyancy provided by the air core promotes phase separation. Solvent-coated bubbles are produced by forming a foam. The foam is injected through a capillary and a

H. M. Tarkan; J. A. Finch

2005-01-01

277

Topologically invariant reaction coordinates for simulating multistate chemical reactions.  

PubMed

Evaluating free energy profiles of chemical reactions in complex environments such as solvents and enzymes requires extensive sampling, which is usually performed by potential of mean force (PMF) techniques. The reliability of the sampling depends not only on the applied PMF method but also the reaction coordinate space within the dynamics is biased. In contrast to simple geometrical collective variables that depend only on the positions of the atomic coordinates of the reactants, the E(gap) reaction coordinate (the energy difference obtained by evaluating a suitable force field using reactant and product state topologies) has the unique property that it is able to take environmental effects into account leading to better convergence, a more faithful description of the transition state ensemble and therefore more accurate free energy profiles. However, E(gap) requires predefined topologies and is therefore inapplicable for multistate reactions, in which the barrier between the chemically equivalent topologies is comparable to the reaction activation barrier, because undesired "side reactions" occur. In this article, we introduce a new energy-based collective variable by generalizing the E(gap) reaction coordinate such that it becomes invariant to equivalent topologies and show that it yields more well behaved free energy profiles than simpler geometrical reaction coordinates. PMID:23214508

Mones, Letif; Csányi, Gábor

2012-12-17

278

Early Intervention Service Coordination Models and Service Coordinator Practices  

ERIC Educational Resources Information Center

The relationship between three different service coordinator models (dedicated and independent, dedicated but not independent, and blended) and the use of nine different service coordinator practices was examined in a study of families of infants and toddlers enrolled in the IDEA Part C early intervention program. Results showed that service…

Dunst, Carl J.; Bruder, Mary Beth

2006-01-01

279

Fault zone fabric and fault weakness.  

PubMed

Geological and geophysical evidence suggests that some crustal faults are weak compared to laboratory measurements of frictional strength. Explanations for fault weakness include the presence of weak minerals, high fluid pressures within the fault core and dynamic processes such as normal stress reduction, acoustic fluidization or extreme weakening at high slip velocity. Dynamic weakening mechanisms can explain some observations; however, creep and aseismic slip are thought to occur on weak faults, and quasi-static weakening mechanisms are required to initiate frictional slip on mis-oriented faults, at high angles to the tectonic stress field. Moreover, the maintenance of high fluid pressures requires specialized conditions and weak mineral phases are not present in sufficient abundance to satisfy weak fault models, so weak faults remain largely unexplained. Here we provide laboratory evidence for a brittle, frictional weakening mechanism based on common fault zone fabrics. We report on the frictional strength of intact fault rocks sheared in their in situ geometry. Samples with well-developed foliation are extremely weak compared to their powdered equivalents. Micro- and nano-structural studies show that frictional sliding occurs along very fine-grained foliations composed of phyllosilicates (talc and smectite). When the same rocks are powdered, frictional strength is high, consistent with cataclastic processes. Our data show that fault weakness can occur in cases where weak mineral phases constitute only a small percentage of the total fault rock and that low friction results from slip on a network of weak phyllosilicate-rich surfaces that define the rock fabric. The widespread documentation of foliated fault rocks along mature faults in different tectonic settings and from many different protoliths suggests that this mechanism could be a viable explanation for fault weakening in the brittle crust. PMID:20016599

Collettini, Cristiano; Niemeijer, André; Viti, Cecilia; Marone, Chris

2009-12-17

280

Solvent cavitation under solvophobic confinement.  

PubMed

The stability of liquids under solvophobic confinement can tip in favor of the vapor phase, nucleating a liquid-to-vapor phase transition that induces attractive forces between confining surfaces. In the case of water adjacent to hydrophobic surfaces, experimental and theoretical evidence support confinement-mediated evaporation stabilization of biomolecular and colloidal assemblies. The macroscopic thermodynamic theory of cavitation under confinement establishes the connection between the size of the confining surfaces, interfacial free energies, and bulk solvent pressure with the critical evaporation separation and interfacial forces. While molecular simulations have confirmed the broad theoretical trends, a quantitative comparison based on independent measurements of the interfacial free energies and liquid-vapor coexistence properties has, to the best of our knowledge, not yet been performed. To overcome the challenges of simulating a large number of systems to validate scaling predictions for a three-dimensional fluid, we simulate both the forces and liquid-vapor coexistence properties of a two-dimensional Lennard-Jones fluid confined between solvophobic plates over a range of plate sizes and reservoir pressures. Our simulations quantitatively agree with theoretical predictions for solvent-mediated forces and critical evaporation separations once the length dependence of the solvation free energy of an individual confining plate is taken into account. The effective solid-liquid line tension length dependence results from molecular scale correlations for solvating microscopic plates and asymptotically decays to the macroscopic value for plates longer than 150 solvent diameters. The success of the macroscopic thermodynamic theory at describing two-dimensional liquids suggests application to surfactant monolayers to experimentally confirm confinement-mediated cavitation. PMID:23947875

Ashbaugh, Henry S

2013-08-14

281

Solvent refined coal (SRC) process  

SciTech Connect

This report summarizes the progress of the Solvent Refined Coal (SRC) project by The Pittsburg and Midway Coal Mining Co. at the SRC Pilot Plant in Fort Lewis, Washington and the Gulf Science and Technology Company Process Development Unit (P-99) in Harmarville, Pennsylvania, for the Department of Energy during the month of October, 1980. The Fort Lewis Pilot Plant was shut down the entire month of October, 1980 for inspection and maintenance. PDU P-99 completed two runs during October investigating potential start-up modes for the Demonstration Plant.

Not Available

1980-12-01

282

Physical solvent for gas sweetening  

SciTech Connect

The alkanolpyridines, as physical solvents, compare favorably, as a family, with sulfolane in their absorption of hydrogen sulfide and mercaptans. The data show absorption differences of the alkanolpyridines diluted with water, as compared with the alkanolpyridines mixed with amine. Both sets of data indicate an absorption performance substantially equal to, or better than, the performance of sulfolane. The chemical structure of pyridine is shown below. This structure is shown with the understanding that the alkanolpyridines would have the propanol or carbinol radicals, which are also shown, or other alkanol radicals substituted at the 2, 3 or 4 position.

Ferrin, C.R.; Manning, W.P.

1982-11-23

283

The Neural Network In Coordinate Transformation  

NASA Astrophysics Data System (ADS)

In international literature, Coordinate operations is divided into two categories. They are coordinate conversion and coordinate transformation. Coordinates converted from coordinate system A to coordinate system B in the same datum (mean origine, scale and axis directions are same) by coordinate conversion. There are two different datum in coordinate transformation. The basis of each datum to a different coordinate reference system. In Coordinate transformation, coordinates are transformed from coordinate reference system A to coordinate referance system B. Geodetic studies based on physical measurements. Coordinate transformation needs identical points which were measured in each coordinate reference system (A and B). However it is difficult (and need a big reserved budget) to measure in some places like as top of mountain, boundry of countries and seaside. In this study, this sample problem solution was researched. The method of learning which is one of the neural network methods, was used for solution of this problem.

Urusan, Ahmet Yucel

2011-12-01

284

A COMPARISON OF PHYSICAL SOLVENTS FOR ACID GAS REMOVAL  

Microsoft Academic Search

Physical solvents such as DEPG (Selexol™ or Coastal AGR®), NMP or N-Methyl-2- Pyrrolidone (Purisol®), Methanol (Rectisol®), and Propylene Carbonate (Fluor Solvent™) are becoming increasingly popular as gas treating solvents, especially for coal gasification applications. Physical solvents tend to be favored over chemical solvents when the concentration of acid gases or other impurities is very high. In addition, physical solvents can

Barry Burr; Lili Lyddon

285

The geometry and significance of weak energy  

Microsoft Academic Search

The theory of weak values for quantum mechanical observables has come to serve as a useful basis for contemporary discussions concerning such varied topics as the tunnelling-time controversy and quantum stochastic processes. An intrinsic complex-valued weak energy has recently been observed experimentally and reported in the literature. In this paper it is shown that: (a) the real and imaginary valued

A. D. Parks

2000-01-01

286

On modeling weak sinks in MODPATH.  

PubMed

Regional groundwater flow systems often contain both strong sinks and weak sinks. A strong sink extracts water from the entire aquifer depth, while a weak sink lets some water pass underneath or over the actual sink. The numerical groundwater flow model MODFLOW may allow a sink cell to act as a strong or weak sink, hence extracting all water that enters the cell or allowing some of that water to pass. A physical strong sink can be modeled by either a strong sink cell or a weak sink cell, with the latter generally occurring in low-resolution models. Likewise, a physical weak sink may also be represented by either type of sink cell. The representation of weak sinks in the particle tracing code MODPATH is more equivocal than in MODFLOW. With the appropriate parameterization of MODPATH, particle traces and their associated travel times to weak sink streams can be modeled with adequate accuracy, even in single layer models. Weak sink well cells, on the other hand, require special measures as proposed in the literature to generate correct particle traces and individual travel times and hence capture zones. We found that the transit time distributions for well water generally do not require special measures provided aquifer properties are locally homogeneous and the well draws water from the entire aquifer depth, an important observation for determining the response of a well to non-point contaminant inputs. PMID:23025655

Abrams, Daniel; Haitjema, H; Kauffman, L

2012-10-01

287

Weak Interactions with Lepton-Hadron Symmetry  

Microsoft Academic Search

We propose a model of weak interactions in which the currents are constructed out of four basic quark fields and interact with a charged massive vector boson. We show, to all orders in perturbation theory, that the leading divergences do not violate any strong-interaction symmetry and the next to the leading divergences respect all observed weak-interaction selection rules. The model

S. L. Glashow; J. Iliopoulos; L. Maiani

1970-01-01

288

Fixing Employee Weaknesses: Addressing the Myth.  

ERIC Educational Resources Information Center

Suggests that human resources development professionals need to change their performance improvement focus and philosophy to embrace the importance of building on strengths and managing weaknesses. Identifies five characteristics indicative of employees' strengths. Describes seven strategies to help employees minimize their weaknesses while…

Gilley, Jerry W.

2001-01-01

289

Staggering towards a calculation of weak amplitudes  

SciTech Connect

An explanation is given of the methods required to calculate hadronic matrix elements of the weak Hamiltonians using lattice QCD with staggered fermions. New results are presented for the 1-loop perturbative mixing of the weak interaction operators. New numerical techniques designed for staggered fermions are described. A preliminary result for the kaon B parameter is presented. 24 refs., 3 figs.

Sharpe, S.R.

1988-09-01

290

Weak ordering—a new definition  

Microsoft Academic Search

A memory model for a shared memory, multiprocessor commonly and often implicitly assumed by programmers is that of sequential consistency. This model guarantees that all memory accesses will appear to execute atomically and in program order. An alternative model, weak ordering, offers greater performance potential. Weak ordering was first defined by Dubois, Scheurich and Briggs in terms of a set

Sarita V. Adve; Mark D. Hill

1990-01-01

291

Network Markets and Consumer Coordination  

Microsoft Academic Search

This paper assumes that groups of consumers in network markets can coordinate their choices when it is in their best interest to do so, and when coordination does not require communication. It is shown that multiple asymmetric networks can coexist in equilibrium if consumers have heterogeneous reservation values. A monopolist provider might choose to operate multiple networks to price differentiate

Attila Ambrus; Rossella Argenziano

2004-01-01

292

Formation control using generalized coordinates  

Microsoft Academic Search

This paper develops a control methodology which allows a number of vehicles to move as a group while maintaining a desired formation pattern. The control is based on the use of generalized coordinates. These coordinates characterize the location (L), orientation (O), and shape (S) of the formation. This provides a natural and convenient way of specifying configuration and allows the

Stephen Spry; J. Karl Hedrick

2004-01-01

293

Newtonian and relativistic emission coordinates  

NASA Astrophysics Data System (ADS)

Emission coordinates are those generated by positioning systems. Positioning systems are physical systems constituted by four emitters broadcasting their respective times by means of sound or light signals. We analyze the incidence of the space-time causal structure on the construction of emission coordinates. The Newtonian case of four emitters at rest is analyzed and contrasted with the corresponding situation in special relativity.

Coll, Bartolomé; Ferrando, Joan Josep; Morales-Lladosa, Juan Antonio

2009-09-01

294

Cockpit and Cabin Crew Coordination.  

National Technical Information Service (NTIS)

Cockpit and cabin crew coordination is crucial not only in emergencies, but also during normal operations. The purposes of this study were to determine the status of crew coordination in the industry and to identify the implications for flight safety. Thi...

K. M. Cardosi M. S. Huntley

1988-01-01

295

Chameleon Graphing: The Coordinate Plane  

NSDL National Science Digital Library

This Web unit introduces the coordinate plane with the help of Sam the Chameleon, who illustrates how to find points on a number line and graph points in the coordinate plane. A link to a Java applet for graphing with Sam is included.

Whitcher, Ursula

2000-01-01

296

Scalable Coordination in Sensor Networks  

Microsoft Academic Search

Network sensorsthose that coordinate amongst themselvesto achieve a larger sensing taskwill revolutionizeinformation gathering and processing both in urban environmentsand in inhospitable terrain. The sheer numbers ofthese sensors and the expected dynamics in these environmentspresent unique challenges in the design of unattendedautonomous sensor networks. These challenges lead us tohypothesize that sensor network coordination applicationsmay need to be structured dierently from...

Deborah Estrin; John Heidemann; Ramesh Govindan

1999-01-01

297

Graphing and the Coordinate Plane  

NSDL National Science Digital Library

This lesson is designed to introduce students to graphing coordinates and lines in the Cartesian coordinate plane. This lesson provides links to discussions and activities related to graphing as well as suggested ways to integrate them into the lesson. Finally, the lesson provides links to follow-up lessons designed for use in succession with the current one.

2010-01-01

298

Effect of Ligand Structural Isomerism in Formation of Calcium Coordination Networks  

SciTech Connect

Using different structural isomers (2,5-; 2,4-; 2;6-; 3,4-; 3,5-) of pyridinedicarboxylic acid, nine calcium-based coordination networks were synthesized under hydro-/solvothermal conditions and/or were produced via solvent recrystallization of previously synthesized compounds. The coordination networks reported were characterized using single crystal X-ray diffraction and thermal methods. They show diverse structural topologies, depending on the ligand geometry and coordinated solvent molecules, with inorganic connectivity motifs ranging from isolated octahedra to infinite chains, layer and a three-dimensional dense framework. The as-synthesized and desolvated networks further show structural transformation to hydrated phases through dissolution/reformation pathways. The process is likely driven by the high hydration energy of the calcium metal center.

Plonka A. M.; Parise J.; Banerjee, D.

2012-03-28

299

Molecular accessibility in solvent swelled coals. Quarterly report, [September--November, 1993  

SciTech Connect

This quarter, experiments were performed on the use of binary swelling solvents in molecular accessibility in coal conversion. These experiments consisted of accessibility measurements of spin probe VII (TEMPAMINE) in Toluene swelled Illinois No. 6 APCS coal. The toluene was spiked with amounts of pyridine which ranged in concentration from 500 ppm to 10%. The experiments were done in triplicate to gain information about the experimental error involved in the procedure. It was shown that oscillations occur in the concentration of spin probe retained as the amount of pyridine that is added to the swelling solvent is increased. These oscillations decrease in intensity as the concentration of pyridine in the solvent solution is increased up to 2% pyridine (0.2mLs pyridine in 10mLs toluene). From a 2% pyridine concentration to a 5% concentration, there is no significant change in the retention of spin probe VII. An increase in retention is observed when the concentration of pyridine is increased to 6% and 7% successively, followed by a large decrease at 8% and 9% pyridine. The largest changes in spin probe retention are observed for concentrations of pyridine less than 0.5%. A three fold increase in spin probe retention is observed upon the addition of 500 ppm pyridine in the toluene swelling solvent, which indicates that small amounts of a strong swelling solvent could be used to improve molecular accessibility 91% in coals swelled in an otherwise weak swelling solvent.

Kispert, L.D.

1993-11-01

300

Glycerol and glycerol carbonate as ultraviscous solvents for mixture analysis by NMR.  

PubMed

NMR of weakly polar analytes in an apolar ultraviscous solvent has recently been proposed for mixture analysis as a pertinent alternative to the DOSY experiment. The present article reports the first use of glycerol and glycerol carbonate as polar solvents for the NMR analysis of a model mixture of dipeptides. This work demonstrates the high potentiality of these solvents for the analysis of mixtures made of polar and potentially bioactive compounds. Medium-sized molecules slowly reorient in glycerol and glycerol carbonate under particular temperature conditions, so that solute resonances may show spin diffusion in NOESY spectra, thus opening the way to mixture analysis. Glycerol and glycerol carbonate have turned out to be ultraviscous solvents of choice for the individualization of four structurally close mixed dipeptides: Leu-Val, Leu-Tyr, Gly-Tyr and Ala-Tyr by means of 1D and 2D NOESY experiments. Selective sample excitation and signal detection were implemented to eliminate the intense proton signals of the non-deuterated solvents. Moreover, the recording of a multiplet selective 2D NOESY-TOCSY has shown that the analytical power of NMR in highly viscous solvents is not limited to the extraction of mixture component 1D subspectra but may also yield some supplementary information about atom connectivity within components. PMID:21802324

Lameiras, Pedro; Boudesocque, Leslie; Mouloungui, Zéphirin; Renault, Jean-Hugues; Wieruszeski, Jean-Michel; Lippens, Guy; Nuzillard, Jean-Marc

2011-07-01

301

Screening of TODGA/TBP/OK solvent mixtures for the grouped extraction of actinides  

NASA Astrophysics Data System (ADS)

The solvent combination N,N,N'N'- tetraoctyl diglycolamide (TODGA)/tributyl phosphate (TBP)/odourless kerosene (OK) is examined as a potential solvent system for a Grouped Actinide Extraction (GANEX) process to separate all of the actinides from fission products when reprocessing spent nuclear fuel. A series of solvent extraction batch experiments were performed with a range of TODGA/TBP/OK solvent combinations to assess the sensitivity of distribution values for a number of key elements towards [TBP] (0 — 1.1M), [TODGA] (0.1-0.4M), [HNO3] (0.1-5M) and heavy metal loading ([U] 0-200g/l). There is little impact on DAm or DEu across the solvent range and no influence from U loading. Excellent DNp values (> 10) are observed, increasing with increasing [TODGA], with [TBP] having little influence. Such high DNp values may obviate the need for preconditioning of dissolved fuel feeds to control Np routing. High DTc values are found even at 5M HNO3, therefore Tc is expected to remain in the solvent phase. Both Pu(III) and Pu(IV) are readily extracted with DPu(III) > DPu(IV). Uranium is extracted by both TBP and TODGA and TBP is shown to effectively compete with TODGA for uranium coordination sites. Third phase formation occurs at high [U] loading and [HNO3] but is suppressed by increasing [TBP].

Brown, Jamie; Carrott, Michael J.; Fox, O. Danny; Maher, Chris J.; Mason, Chris; McLachlan, Fiona; Sarsfield, Mark J.; Taylor, Robin J.; Woodhead, Dave A.

2010-03-01

302

Radical hydrogen-transfer: Rationalization of interactive effects of solvent aromaticity and hydrogen pressure on coal liquefaction  

SciTech Connect

This paper focuses on the use of a mechanistic model of hydrogen-transfer-induced bond scission to rationalize some interesting liquefaction and hydropyrolysis results that have recently appeared in the literature. These literature results were chosen because they relate directly to the efficiency with which hydrogen is used to produce the desired products, and because they are counter-intuitive and/or exhibit substantial changes in yield structure resulting from apparently minor changes in conditions. In the conventional view of liquefaction, inherently weak bonds in coal undergo thermolysis upon heating, and the solvent merely serves to stabilize these thermally generated radicals. The solvent is not involved in engendering bond-scission. We have previously shown that this mechanism is not consistent with the observed order of liquefaction abilities of various solvents. This inconsistency has also been recognized by some researchers. We have proposed an alternate model for coal liquefaction in which solvents mediate hydrogenolysis of strong bonds with varying degrees of effectiveness. These alternative views of coal liquefaction are depicted in the reactions given. We do not mean to imply that weak bonds do not undergo thermolysis during coal liquefaction. To the extent that there are weak bonds in the coal structure, they will undergo thermolysis; however, the critical factor that determines the efficacy of various solvent systems is their ability in bringing about H-transfer to cause cleavage of strong bonds.

McMillen, D.F.; Malhotra, R.; Nigenda, S.E.

1986-10-01

303

STUDY OF SOLVENT AND CATALYST INTERACTIONS IN DIRECT COAL LIQUEFACTION  

SciTech Connect

There are several aspects of the Direct Coal Liquefaction process which are not fully understood and which if better understood might lead to improved yields and conversions. Among these questions are the roles of the catalyst and the solvent. While the solvent is known to act by transfer of hydrogen atoms to the free radicals formed by thermal breakdown of the coal in an uncatalyzed system, in the presence of a solid catalyst as is now currently practiced, the yields and conversions are higher than in an uncatalyzed system. The role of the catalyst in this case is not completely understood. DOE has funded many projects to produce ultrafine and more active catalysts in the expectation that better contact between catalyst and coal might result. This approach has met with limited success probably because mass transfer between two solids in a fluid medium i.e. the catalyst and the coal, is very poor. It is to develop an understanding of the role of the catalyst and solvent in Direct Liquefaction that this project was initiated. Specifically it was of interest to know whether direct contact between the coal and the catalyst was important. By separating the solid catalyst in a stainless steel basket permeable to the solvent but not the coal in the liquefaction reactor, it was shown that the catalyst still maintains a catalytic effect on the liquefaction process. There is apparently transfer of hydrogen atoms from the catalyst through the basket wall to the coal via the solvent. Strong hydrogen donor solvents appear to be more effective in this respect than weak hydrogen donors. It therefore appears that intimate contact between catalyst and coal is not a requirement, and that the role of the catalyst may be to restore the hydrogen donor strength to the solvent as the reaction proceeds. A range of solvents of varying hydrogen donor strength was investigated. Because of the extensive use of thermogravimetric analysis in this laboratory in was noted that the peak temperature for volatile evolution from coal was a reliable measure of coal rank. Because of this observation, a wide variety of coals of a wide range of ranks was investigated. It was shown in this work that measuring the peak temperature for volatile evolution was quite a precise indicator of rank and correlated closely wit the rank values obtained by measuring vitrinite reflectance, a more difficult measurement to make. This prompted the desire to know the composition of the volatile materials evolved as a function of coal rank. This was then measured by coupling a TGA to a mass spectrometer using laser activation and photoionization detection TG-PI-MS. The predominant species in volatiles of low rank coal turned out to be phenols with some alkenes. As the rank increases, the relative amount of alkenes and aromatic hydrocarbons increases and the oxygenated species decrease. It was shown that these volatiles were actually pyrolitic products and not volatilization products of coal. Solvent extraction experiments coupled with TG-PI-MS indicates that the low oiling and more extractable material are essentially similar in chemical types to the non-extractable portions but apparently higher molecular weight and therefor less extractable.

Michael T. Klein

2000-01-01

304

Solvent characterization using the dispersion number  

SciTech Connect

When developing new solvent extraction processes, one often has to evaluate new solvents, new aqueous phases, or both for their ability to work in plant-scale equipment. To facilitate solvent characterization, a simple test is proposed based on the dimensionless dispersion number (N{sub Di}). It allows one to characterize the ability of the solvent to separate from a two-phase dispersion and to estimate process throughput for equipment for a given size. Several ways to carry out the N{sub Di} test are given, including a standard test procedure. The N{sub Di} test was applied to the performance of solvent extraction equipment with discrete process stages, the leaching of plasticizers from plastic tubing, and the development of a new solvent for the combined extraction of strontium and transuranic elements.

Leonard, R.A. [Argonne National Laboratory, IL (United States)

1995-04-01

305

Solvent dependent photophysical properties of dimethoxy curcumin  

NASA Astrophysics Data System (ADS)

Dimethoxy curcumin (DMC) is a methylated derivative of curcumin. In order to know the effect of ring substitution on photophysical properties of curcumin, steady state absorption and fluorescence spectra of DMC were recorded in organic solvents with different polarity and compared with those of curcumin. The absorption and fluorescence spectra of DMC, like curcumin, are strongly dependent on solvent polarity and the maxima of DMC showed red shift with increase in solvent polarity function (?f), but the above effect is prominently observed in case of fluorescence maxima. From the dependence of Stokes' shift on solvent polarity function the difference between the excited state and ground state dipole moment was estimated as 4.9 D. Fluorescence quantum yield (?f) and fluorescence lifetime (?f) of DMC were also measured in different solvents at room temperature. The results indicated that with increasing solvent polarity, ?f increased linearly, which has been accounted for the decrease in non-radiative rate by intersystem crossing (ISC) processes.

Barik, Atanu; Indira Priyadarsini, K.

2013-03-01

306

Hydrocarbon separation with a physical solvent  

SciTech Connect

This patent describes a continuous process for producing a liquid hydrocarbon product of a selected composition, which is selectively adjustable to substantially any selected degree in accordance with market conditions, and a residue natural gas stream of pipeline quality that selectively includes ethane (C/sub 2/), propane (C/sub 3/), and butanes (C/sub 4/) by extraction of an inlet natural gas stream, containing at least 0.2 mol percent of C/sub 5/+ hydrocarbons, with a stream of a physical solvent, the improvement described here consists of minimizing the energy required for the process while recovering up to 100% of the C/sub 5/+ hydrocarbons in accordance with the market conditions by the following steps: A. selectively extracting the inlet natural gas stream in a first extraction stage with a major solvent stream and in a second extraction stage with a minor solvent stream, the major solvent stream containing up to an equilibrium amount of C/sub 5/+ hydrocarbons and the minor solvent stream being lean with respect to C/sub 1/+ hydrocarbons, whereby a rich solvent stream and a residue natural gas stream are produced, the residue natural gas stream containing selected maximum amounts of C/sub 2/+ hydrocarbons in accordance with the market conditions; B. successively flashing the rich solvent stream in a plurality of flashing stages at pressures that successively decrease to about atmospheric pressure in order to produce successive C/sub 1/+ gas fractions, having successively lower methane contents, and flashed solvent streams containing the solvent and hydrocarbons having successively lower methane contents, the flashing pressures of the successive flashing stages being selectively varied; C. dividing the physical solvent stream into the major solvent stream and a slipstream; and D. regenerating the slipstream in order to produce the minor solvent stream for the second extraction stage.

Mehra, Y.R.

1986-03-25

307

Femtosecond dynamics in hydrogen-bonded solvents  

SciTech Connect

We present results on the ultrafast dynamics of pure hydrogen-bonding solvents, obtained using femtosecond Fourier-transform optical-heterodyne-detected, Raman-induced Kerr effect spectroscopy. Solvent systems we have studied include the formamides, water, ethylene glycol, and acetic acid. Inertial and diffusive motions are clearly resolved. We comment on the effect that such ultrafast solvent motions have on chemical reactions in solution.

Castner, E.W. Jr.; Chang, Y.J.

1993-09-01

308

Recovery of neutral-solvent fermentation products  

SciTech Connect

The economics of several separation techniques (distillation, crystallization, and solvent extraction) were evaluated for use as a preliminary step in the recovery of neutral solvents from a fermenter exit stream containing primarily n-butanol, isopropanol, ethanol, and water. A comparison of the resulting costs indicated that distillation is substantially less expensive than crystallization for 1979 pricing. No economic study was performed for solvent extraction because the separation was poor.

Grosset, A.M.; Fok, S.K.; Lemarchand, M.

1980-06-01

309

Accelerated solvent extraction for natural products isolation.  

PubMed

Accelerated solvent extraction (ASE(®)), first introduced in 1995, is an automated rapid extraction technique that utilizes common solvents at elevated temperature and pressure, and thereby increases the efficiency of extraction of organic compounds from solid and semisolid matrices. ASE(®) allows extractions for sample sizes 1-100 g in minutes, reduces solvent uses dramatically, and can be applied to a wide range of matrices, including natural products. PMID:22367894

Mottaleb, Mohammad A; Sarker, Satyajit D

2012-01-01

310

Solvent winterization of sunflower seed oil  

Microsoft Academic Search

Samples of oil from whole and dehulled sunflower seed were solvent winterized. The solvent mixture, 85% acetone, 15% hexane\\u000a (v\\/v), was used at solvent-in-oil concentrations of 20, 40, and 70% by wt and the samples winterized at 0, ?5, ?10, and ?15\\u000a .01 C for 4 hr. Generally, sunflower oils from whole seed remained free from cloud formation longer on

W. Herbert Morrison; James A. Robertson

1975-01-01

311

Adaptation of Rhodococcus to Organic Solvents  

Microsoft Academic Search

\\u000a Bacterial tolerance and ability to adapt to organic solvents can be of valuable importance in biocatalytic and bioremediation\\u000a processes. Strains of Rhodococcus have been reported to be particularly solvent tolerant, while presenting a broad array of enzymes with potential for the\\u000a production of commercially interesting compounds and\\/or for the metabolism of recalcitrant organic solvents. The adaptability\\u000a and versatility of Rhodococcus

312

Triethylborane-induced bromine atom-transfer radical addition in aqueous media: study of the solvent effect on radical addition reactions.  

PubMed

A mixture of ethyl bromoacetate and 1-octene was treated with triethylborane in water at ambient temperature to provide ethyl 4-bromodecanoate in good yield. The bromine atom-transfer radical addition in benzene was not satisfactory. The addition proceeded smoothly in polar solvents such as DMF and DMSO, protic solvents such as 2,2,2-trifluoroethanol and 1,1,1,3,3,3-hexafluoro-2-propanol, and aqueous media. Ab initio calculations were conducted to reveal the origin of the solvent effect of water in the addition reaction. The polar effect of solvents, which is judged by the dielectric constant, on the transition states in the bromine atom-transfer and radical addition steps is moderately important. Calculations show that a polar solvent tends to lower the relative energies of the transition states. The coordination of a carbonyl group to a proton in a protic solvent, like a Lewis acid, would also increase the efficiency of the propagation. PMID:11701036

Yorimitsu, H; Shinokubo, H; Matsubara, S; Oshima, K; Omoto, K; Fujimoto, H

2001-11-16

313

Weak-source for cryogenic semiconductor device  

SciTech Connect

A two-gate field-effect transistor (FET) is designed to operate at cryogenic temperatures (circa 1/sup 0/-20/sup 0/ K.). For an N channel FET, the low-concentration weak-P type material used for the channel region is built into an intrinsic (or near-intrinsic) layer which in turn is built on a P type substrate. The first gate corresponds to a conventional FET control gate. The second gate may be designated a weak-source gate and is directly above a corresponding weak-source region which is itself adjacent to the conventional (strong) source region. The weak-source gate is placed at a fixed positive potential with respect to the source region so that the electrons will collect in the conduction band within the weak-source region. Once the required fixed weak-source gate potential has been established, the control gate functions in a conventional manner even when the device is at a cryogenic temperature. Such a weak-source gate over a weak-source region may be utilized to inject carriers into a charge-coupled device, or any similar device, even at cryogenic temperatures. The device channel region can, alternatively, be made of the same non-conductive low concentration N type material as the weak-source region and can be the same as the material used for the absorption of infrared photons by the associated infrared detectors thus allowing the simultaneous epitaxial construction of both the FET/CCD electronics and the associated infrared detectors.

Levine, M.A.

1985-02-12

314

40 CFR 148.10 - solvent wastes.  

Code of Federal Regulations, 2010 CFR

...PROGRAMS (CONTINUED)] [Part 148 - HAZARDOUS WASTE INJECTION RESTRICTIONS] [Subpart B - Prohibitions on Injection] [Sec. 148.10 Waste Specific Prohibitions - solvent wastes.] 40 PROTECTION OF ENVIRONMENT 22...

2009-07-01

315

Process for hydrogenating coal and coal solvents  

DOEpatents

A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260.degree. C. to 315.degree. C. in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275.degree. C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350.degree. C.

Tarrer, Arthur R. (Auburn, AL); Shridharani, Ketan G. (Auburn, AL)

1983-01-01

316

MCU MATERIALS COMPATIBILITY WITH CSSX SOLVENT  

SciTech Connect

The Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) plans to use several new materials of construction not previously used with CSSX solvent. SRNL researchers tested seven materials proposed for service in seal and gasket applications. None of the materials leached detectable amounts of components into the CSSX solvent during 96 hour tests. All are judged acceptable for use based on their effect on the solvent. However, some of the materials adsorbed solvent or changed dimensions during contact with solvent. Consultation with component and material vendors with regard to performance impact and in-use testing of the materials is recommended. Polyetheretherketone (PEEK), a material selected for use in contactor bearing seals, did not gain weight or change dimensions on contact with CSSX solvent. Analysis of the solvent contacted with this material showed no impurities and the standard dispersion test gave acceptable phase separation results. The material contains a leachable hydrocarbon substance, detectable on exposed surfaces, that did not adversely contaminate the solvent within the limits of the testing. We recommend contacting the vendor to determine the source and purpose of this component, or, alternatively, pursue the infrared analysis of the PEEK in an effort to better define potential impacts.

Fondeur, F

2006-01-13

317

Relationship between Fermi Resonance and Solvent Effects  

NASA Astrophysics Data System (ADS)

We theoretically and experimentally study the relationship between Fermi resonance and solvent effects and investigate the Fermi resonance of p-benzoquinone and cyclopentanone in different solvents and the Fermi resonance of CS2 in C6H6 at different concentrations. Also, we investigate the Fermi resonance of C6H6 and CCl4 in their solution at different pressures. It is found that solvent effects can be utilized to search Fermi resonance parameters such as coupling coefficient and spectral intensity ratio, etc., on the other hand, the mechanism of solvent effects can be revealed according to Fermi resonance at high pressure.

Jiang, Xiu-Lan; Li, Dong-Fei; Sun, Cheng-Lin; Li, Zhan-Long; Yang, Guang; Zhou, Mi; Li, Zuo-Wei; Gao, Shu-Qin

2011-05-01

318

Synthesis of soluble polypyrrole of the doped state in organic solvents  

Microsoft Academic Search

Polypyrrole soluble in m-cresol and conditionally soluble in chloroform, dichloromethane or 1,1,2,2-tetrachloroethane was synthesized chemically by using dodecylbenzene sulfonic acid as the dopant and ammonium persulfate as the oxidant. The polymer was soluble in m-cresol and became soluble in the weakly poor solvents such as chloroform, dichloromethane and 1,1,2,2-tetrachloroethane when equal amounts of dodecylbenzene sulfonic acid and polymer were added

J. Y. Lee; D. Y. Kim; C. Y. Kim

1995-01-01

319

Weak Transition Form Factors Using Electron Beams  

NASA Astrophysics Data System (ADS)

Using the formalism of Mintz(Nuclear Physics A657 (1999) 303-314), I examine the further potential for p(e^-,?)? measurements to improve our understanding of strangeness-changing weak transition form factors. Specifically, the Q^2 dependence of the dominant axial and vector transition form factors, and the feasibility of observing the weak magnetic and weak electric contributions, is examined. The sensitivity of a possible experiment at JLab using the CLAS detector is discussed. Backgrounds are a serious concern due to the very low rate for the events of interest.

Mack, David

2003-04-01

320

Complex weak values in quantum measurement  

SciTech Connect

In the weak value formalism of Aharonov et al., the weak value A{sub w} of any observable A is generally a complex number. We derive a physical interpretation of its value in terms of the shift in the measurement pointer's mean position and mean momentum. In particular, we show that the mean position shift contains a term jointly proportional to the imaginary part of the weak value and the rate at which the pointer is spreading in space as it enters the measurement interaction.

Jozsa, Richard [Department of Computer Science, University of Bristol, Merchant Venturers Building, Bristol BS8 1UB (United Kingdom)

2007-10-15

321

Particle motion in weak relativistic gravitational fields  

NASA Astrophysics Data System (ADS)

We derive the geodesic equation of motion in the presence of weak gravitational fields produced by relativistic sources such as cosmic strings, decomposed into scalar, vector and tensor parts. To test the result, we perform the first N-body simulations with relativistic weak gravitational external fields. Our test case is a moving straight string, for which we recover the well-known result for the impulse on nonrelativistic particles. We find that the vector (gravito-magnetic) force is an essential contributor. Our results mean that it is now possible to incorporate straightforwardly into N-body simulations all weak relativistic sources, including networks of cosmic defects.

Obradovic, Miki; Kunz, Martin; Hindmarsh, Mark; Iliev, Ilian T.

2012-09-01

322

Hot-solvent miscible displacement  

SciTech Connect

This work describes an experimental and theoretical investigation of miscible displacement under nonisothermal conditions. The hot miscible floods were performed in an adiabatic glass bead pack, displacing one hydrocarbon by a more viscous hydrocarbon, the latter being at an elevated temperature. As a result, dispersion of both mass and heat took place, and was determined by temperature and concentration measurements. The system was simulated by coupled convective-diffusion and thermal conduction-convection equations. The results of the numerical as well as an approximate analytical solution were compared with the experimentally observed behavior. The numerical and experimental results point to the factors which should be considered in the choice of a solvent for a thermal-miscible type oil recovery process.

Awang, M.; Farouq Ali, S.M.

1980-01-01

323

Solvent-driven chemical motor  

NASA Astrophysics Data System (ADS)

A solvent-driven chemical motor using amphiphilic polymer gel has been fabricated. The driving force of the gel originates from the surface tension of spreading organic fluid which is pumped out by osmotic and hydrostatic pressures in the gel. A tetrahydrofurane-swollen gel equipped with a spouting hole made a controlled translational motion with a velocity of 77 mm/s or rotational motion with a maximum speed of 400 rpm and a torque of 10-9-10-7 Nm on the water surface. A generator to produce an electric power with a maximum electromotive force of 15 mV and electric power of 0.2 ?W has also been constructed. The successful fabrication of gel motor may produce a new era of soft machine systems which work without pollution and unnecessary intermediates.

Mitsumata, Tetsu; Ikeda, Kazuo; Gong, Jian Ping; Osada, Yoshihito

1998-10-01

324

Desorption of chlorine organic solvents  

SciTech Connect

Adsorption methods are being used more and more widely to treat gaseous discharges containing chlorohydrocarbons. However, recovery of the chlorohydrocarbons has not been studied sufficiently, and the desorption of the solvents with steam is particularly understudied. We investigated desorption of a number of solvents from industrial active carbon AR-3. Desorption was done with live steam in the 105 to 150/sup 0/C. It can be seen from the data that with an increase of the molecular weight of the chlorohydrocarbon, the process of desorption slows down. This is clearly due to the fact that with an increase of the number of chlorine atoms in the molecule there is an increase of dispersion interaction (size of parachors) and latent heat of vaporization, which cause a decrease of the degree of desorption. The rate of desorption increases with an increase in temperature, but most of the investigated chlorine derivatives detach a chlorine ion at elevated temperature in the presence of water and carbon, with formation of HCl, which causes severe equipment corrosion. In addition, phosgene (in the decomposition of C/sub 2/HCl/sub 3/), chlorine organic acids and certain other toxic compounds may be produced. Thus, to reduce the rate of hydrolysis in the desorption of chlorohydrocarbons, especially polychlorinated ones, one should use steam with minimum possible temperature (no more than 110/sup 0/C) with a desorption time of no more than 30 minutes for poorly adsorbable compounds and no more than 45 to 60 minutes for readily absorbable ones. Here the degree of desorption of poorly absorbed compounds is about 100% while that of the readily absorbed ones is from 50 to 75%. The results were used in the design of units for recovery of methylene chloride, dichloroethane and trichloroethylene.

Petrova, N.I.; Nikolaev, K.M.

1982-03-01

325

Wide electrochemical window solvents for use in electrochemical devices and electrolyte solutions incorporating such solvents  

DOEpatents

The present invention relates to electrolyte solvents for use in liquid or rubbery electrolyte solutions. Specifically, this invention is directed to boron-containing electrolyte solvents and boron-containing electrolyte solutions.

Angell, Charles Austen (Mesa, AZ); Zhang, Sheng-Shui (Tucson, AZ); Xu, Kang (Tempe, AZ)

1998-01-01

326

Attraction between Nanoparticles Induced by End-Grafted Homopolymers in Good Solvent  

Microsoft Academic Search

The interactions between nanoparticles coated by end-grafted homopolymers of comparable size are studied using Edwards' self-consistent field (SCF) theory. The equilibrium monomer density distribution is obtained by solving the SCF equations in bispherical coordinates. It is shown that, because of the spherical geometry and redistribution of monomer density, end-grafted homopolymers in good solvent environment can induce attractive interactions. This result

Jiunn-Ren Roan

2001-01-01

327

Coordinating Tectons: Bipyridyl Terminated Allenylidene Complexes  

SciTech Connect

A series of complexes with {pi}-conjugated carbon chains terminated by bipyridyl moieties has been prepared. These allenylidene complexes were derived from 9-hydroxy-9-ethynyl-4,5-diazafluorene, the preparation of which is reported; the new allenylidene complexes are highly colored with the cumulated carbon chain terminating in a bipyridyl unit providing a site for further coordination. The synthesis, characterization, and X-ray structure determination of trans-[MCl(P{intersection}P){sub 2}{sub {double_bond}}C{sub {double_bond}}C{sub {double_bond}}(4,5-diazafluoren-9-yl)]PF{sub 6} (M = Ru, P{intersection}P = bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,2-bis(dimethylphosphino)ethane (dmpe); M = Os, P{intersection}P = dppm) are described. The effect of the variation in metal and ligand on electronic and electrochemical characteristics of these complexes has been investigated by using UV-vis, solution electrochemistry, and a combination of these techniques in spectroelectrochemical experiments. DFT calculations have been performed on trans-[RuCl(P{intersection}P){sub 2}{sub {double_bond}}C{sub {double_bond}}C{sub {double_bond}}(4,5-diazafluoren-9-yl)]{sup q} (P{intersection}P = dppm, bis(dimethylphosphino)methane (dmpm); q = -1, 0, +1, +2) and subsequently solvent-corrected calculations with use of COSMO were also undertaken to examine the nature of electronic transitions in various oxidation states.

Cifuentes, Marie P.; Humphrey, Mark G.; Koutsantonis, George A.; Lengkeek, Nigel A.; Petrie, Simon; Sanford, Vanessa; Schauer, Phil A.; Skelton, Brian W.; Stranger, Robert; White, Allan H. (UWA); (ANU)

2009-01-15

328

Sodium in weak G-band giants  

NASA Astrophysics Data System (ADS)

Sodium abundances have been determined for eight weak G-band giants whose atmospheres are greatly enriched with products of the CN-cycling H-burning reactions. Systematic errors are minimized by comparing the weak G-band giants to a sample of similar but normal giants. If, further, Ca is selected as a reference element, model atmosphere-related errors should largely be removed. For the weak-G-band stars (Na/Ca) = 0.16 +/- 0.01, which is just possibly greater than the result (Na/Ca) = 0.10 /- 0.03 from the normal giants. This result demonstrates that the atmospheres of the weak G-band giants are not seriously contaminated with products of ON cycling.

Drake, Jeremy J.; Lambert, David L.

1994-11-01

329

The Sloan Nearby Cluster Weak Lensing Survey  

SciTech Connect

We describe and present initial results of a weak lensing survey of nearby (z {approx}< 0.1) galaxy clusters in the Sloan Digital Sky Survey (SDSS). In this first study, galaxy clusters are selected from the SDSS spectroscopic galaxy cluster catalogs of Miller et al. and Berlind et al. We report a total of seven individual low-redshift cluster weak lensing measurements that include A2048, A1767, A2244, A1066, A2199, and two clusters specifically identified with the C4 algorithm. Our program of weak lensing of nearby galaxy clusters in the SDSS will eventually reach {approx}200 clusters, making it the largest weak lensing survey of individual galaxy clusters to date.

Kubo, Jeffrey M.; /Fermilab; Annis, James T.; /Fermilab; Hardin, Frances Mei; /Illinois Math. Sci. Acad.; Kubik, Donna; /Fermilab; Lawhorn, Kelsey; /Illinois Math. Sci. Acad.; Lin, Huan; /Fermilab; Nicklaus, Liana; /Illinois Math. Sci. Acad.; Nelson, Dylan; /UC, Berkeley; Reis, Ribamar Rondon de Rezende; /Fermilab; Seo, Hee-Jong; /Fermilab; Soares-Santos, Marcelle; /Fermilab /Inst. Geo. Astron., Havana /Sao Paulo U. /Fermilab

2009-08-01

330

Conductivity of Strong, Weak, and Nonelectrolyte Solutions  

NSDL National Science Digital Library

This is a video clip of strong, weak, and nonelectrolyte solutions conducting electricity. Each solution is tested with the light bulb apparatus and the bulb glows brightly, dimly, or not at all depending on the solution.

Ward, Charles

2007-12-20

331

Coordination of Multiple Robotic Manipulators.  

National Technical Information Service (NTIS)

In this thesis, the problem of the coordination of multiple robots is investigated at length. Included in the discussion are the position control, path planning, and collision avoidance strategies involved in the control of two robots mutually holding an ...

R. F. Young

1987-01-01

332

Coordinating the War on Terrorism.  

National Technical Information Service (NTIS)

The war on terrorism has changed Americans lives and strained the capacities of their government. The Federal Government confronts a confounding array of choices about priorities and coordination. Although the Cold War required synchronizing America's glo...

L. E. Davis G. F. Treverton D. Byman S. Daly W. Rosenau

2004-01-01

333

Technique for Coordinating Autonomous Robots.  

National Technical Information Service (NTIS)

This paper describes a technique for coordinating the subsystems of autonomous robots which takes advantage of a distributed blackboard mechanism and a high degree of functional distribution between subsystems to minimize communications and simplify the i...

S. Y. Harmon W. A. Aviles D. W. Gage

1986-01-01

334

Advising Systems and Institutional Coordination.  

ERIC Educational Resources Information Center

|The advising program may be more amenable to influence and change than other functions within a college or university. Ways that academic advising programs may be used to increase levels of coordination within an institution are described. (MLW)|

Kramer, Howard C.

1985-01-01

335

Sensory Coordination of Insect Flight.  

National Technical Information Service (NTIS)

This report contains the investigation results to the following questions: 1) Antennal positioning behavior in the moth, Daphnis neerii, 2) Location of odor sources in the fruit fly, Drosophila melanogaster, 3) Wing- haltere coordination in the soldier fl...

S. Sane

2010-01-01

336

Distributed Coordinated Collaboration Spaces (DCCS).  

National Technical Information Service (NTIS)

Modern Command and Control: Requies communication, collaboration, and coordination among US (and Coalition) forces; Is synchronous and asynchronous; tactical and strategic in nature Team members often co-located and distributed based upon: (1) Geographica...

J. Pester-DeWan M. St. John M. G. Averett R. A. Moore

2006-01-01

337

Divergence of classical trajectories and weak localization  

Microsoft Academic Search

We study the weak-localization correction (WLC) to transport coefficients of a system of electrons in a static long-range potential (e.g., an antidot array or ballistic cavity). We found that the weak-localization correction to the current response is delayed by the large time tE=lambda-1\\\\|lnh\\\\|, where lambda is the Lyapunov exponent. In the semiclassical regime tE is much larger than the transport

I. L. Aleiner; A. I. Larkin

1996-01-01

338

A Quantum Proxy Weak Blind Signature Scheme  

NASA Astrophysics Data System (ADS)

We present a weak blind signature scheme based on a genuinely entangled six qubits state. Different from classical blind signature schemes and current quantum signature schemes, our quantum weak blind signature scheme could guarantee not only the unconditionally security but also the anonymity of the message owner. To achieve that, quantum key distribution and one-time pad are adopted in our scheme. Our scheme has the characteristics of classical security and quantum security.

Cao, Hai-Jing; Zhu, Yan-Yan; Li, Peng-Fei

2013-09-01

339

Extended Hubbard model at weak coupling  

Microsoft Academic Search

The half-filled extended Hubbard model (including nearest-neighbor interaction) is considered in perturbation theory at weak coupling on a d-dimensional hypercubic lattice (d>~3). It is shown that the exact critical temperature and the exact order parameter in the weak-coupling limit differ from the corresponding Hartree results by a renormalization factor q of order unity. This renormalization factor q is calculated systematically

P. G. J. van Dongen

1994-01-01

340

Oxygen consumption in weakly electric Neotropical fishes  

Microsoft Academic Search

Weakly electric gymnotiform fishes with wave-type electric organ discharge (EOD) are less hypoxia-tolerant and are less likely to be found in hypoxic habitats than weakly electric gymnotiforms with pulse-type EOD, suggesting that differences in metabolism resulting from EOD type affects habitat choice. Although gymnotiform fishes are common in most Neotropical freshwaters and represent the dominant vertebrates in some habitats, the

David Julian; William G. R. Crampton; Stephanie E. Wohlgemuth; James S. Albert

2003-01-01

341

Analysis of solvent extracts from coal liquefaction in a flowing solvent reactor  

Microsoft Academic Search

Point of Ayr coal has been extracted using three solvents, tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP) at two temperatures 350 and 450 °C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. The three solvents differ in solvent power and the ability to donate hydrogen atoms to stabilise free radicals produced by pyrolysis of the

Wen-Ying Li; Jie Feng; Ke-Chang Xie; R Kandiyoti

2004-01-01

342

Radiative Transfer in Weakly Polarizing Media  

NASA Astrophysics Data System (ADS)

We study radiative transfer through a weakly polarizing medium, i.e., a medium in which the degree of polarization of the absorbed, retarded, and emitted light is always weak. In this case, the general radiative transfer equation for the Stokes parameters yields very simple formal solutions. The intensity does not depend on the polarization, and the other Stokes parameters are uncoupled from each other. It is shown how this simplified radiative transfer equation holds in many realistic cases relevant for solar and stellar magnetometry. It can be applied whenever the weak magnetic field approximation works, i.e., for weakly split lines. In addition, it handles weak spectral lines, structures with complex magnetic topology, chromospheric lines formed under non-LTE conditions, etc. The merits of the approximation, which we call the weakly polarizing medium (WPM) approximation, are illustrated by means of several LTE and non-LTE line syntheses in realistic solar model atmospheres. The WPM approximation should be useful in planning and understanding measurements based on polarization. It simplifies the relationship between the observed polarization and the physical structure that one tries to retrieve. The approximation may also be used in numerical problems requiring extensive polarized radiative transfer (inversion codes, syntheses of stellar spectra, self-consistent multilevel non-LTE Zeeman line transfer with atomic polarization, etc.).

Sánchez Almeida, J.; Trujillo Bueno, J.

1999-12-01

343

Weakness and fatigue in diverse neuromuscular diseases.  

PubMed

Weakness and fatigue are captured by the 6-minute walk test, but the relationship between these symptoms is uncertain. Comparison across neuromuscular diseases has not been examined. A cohort study of 114 patients with spinal muscular atrophy, Duchenne/Becker muscular dystrophy, myasthenia gravis, and energy failure syndromes were included. Percent-predicted distance on the 6-minute walk test was computed from normative values to determine weakness. Fatigue was determined by the decrement in distance from the first to sixth minute. Weakness was seen across all groups (61.9%) but significant fatigue was seen only in spinal muscular atrophy (21.0%). Other groups showed little fatigue. Correlation between weakness and fatigue was significant only in spinal muscular atrophy (R = -0.71; P < .001). Longitudinally, distance walked declined only in Duchenne/Becker muscular dystrophy. In spinal muscular atrophy, weakness did not change, but fatigue increased significantly. These findings suggest independent mechanisms underlying weakness and fatigue in diverse neuromuscular conditions. PMID:23847297

Montes, Jacqueline; Blumenschine, Michelle; Dunaway, Sally; Alter, Aliza S; Engelstad, Kristin; Rao, Ashwini K; Chiriboga, Claudia A; Sproule, Douglas M; Vivo, Darryl C De

2013-07-11

344

SOLVENT-FREE ORGANIC SYNTHESES USING MICROWAVES  

EPA Science Inventory

The latest results on microwave-expedited solvent-free approach as applied to the assembly of organic molecules will be presented. The salient features of this expeditious methodology such as solvent conservation and ease of manipulation etc. will be described in the context of r...

345

Pneumatic conveying of pulverized solvent refined coal  

DOEpatents

A method for pneumatically conveying solvent refined coal to a burner under conditions of dilute phase pneumatic flow so as to prevent saltation of the solvent refined coal in the transport line by maintaining the transport fluid velocity above approximately 95 ft/sec.

Lennon, Dennis R. (Allentown, PA)

1984-11-06

346

Localized Scleroderma after Exposure to Organic Solvents  

Microsoft Academic Search

A 26-year-old female developed plaques characteristic of morphea on the volar surfaces of the forearms and on the dorsal surfaces on the ankles following an exposure to trichloroethylene, tetrachloroethylene and other solvents by inhalation. Exposure to chemicals has been known to be important as a provoking factor of systemic sclerosis. This patient shows that exposure to solvents could provoke localized

L. Czirják; E. Pócs; G. Szegedi

1994-01-01

347

Separation of Tributyl Phosphate from Degraded Solvents.  

National Technical Information Service (NTIS)

A solvent extraction method is described for the recovery of tributyl phosphate (TBP) from degraded process solvents. The method involves the separation of TBP and shell solT(SST) from 30% TBP/SSP mixture by thorium nitrate extraction leading to the forma...

S. V. Kumar M. N. Nadkarni A. Ramanujam M. Venkatesan V. Gopalakrishnan

1977-01-01

348

Thin-film evaporator recovers solvents continuously  

Microsoft Academic Search

Reclaimed Energy Company, Inc., Connersville, IN, receives waste generated from a wide variety of industrial applications which include paint, printing and degreasing companies. The wastes are stored in separate tanks and then distilled in batches (pot distillation). The recovered solvents can be returned to the originator. The residue, left after the solvents are distilled, is disposed of using an environmentally

R. Roembke; A. E. Hodel

1985-01-01

349

EDIBLE OIL EXTRACTION SOLVENTS: FDA REGULATORY CONSIDERATIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

When a solvent is used to extract edible oil from oil bearing materials in the United States, federal and state workplace, environmental, and food safety regulations have to be complied with. Hexane has been the solvent of choice to extract edible oils since 1940's. The main component of hexane, n...

350

REMEDIATING PESTICIDE CONTAMINATED SOILS USING SOLVENT EXTRACTION  

EPA Science Inventory

Bench-scale solvent extraction studies were performed on soil samples obtained from a Superfund site contaminated with high levels of p,p'-DDT, p,p'-DDD,, p,p'-DDE and toxaphene. The effectiveness of the solvent extraction process was assessed using methanol and 2-propanol as sol...

351

SAFETY OF ORGANIC SOLVENTS IN WASTE TANKS  

SciTech Connect

This report addresses flash points and flammability limits of flammable gases found in waste tanks, primarily hydrocarbon mixtures derived from waste solvents. The effect of vapor pressure is discussed. Particular attention is given to Purex solvent. The pertinent facts are then applied to the safety of the waste tanks of concern.

Van Tuyl, H. H.

1983-08-01

352

Gallium complexes and solvent extraction of gallium  

SciTech Connect

This patent describes a process for recovering gallium from aqueous solutions containing gallium which comprises contacting such a solution with an organic solvent containing at least 2% by weight of a water-insoluble N-organo hydroxamic acid having at least about 8 carbon atoms to extract gallium, and separating the gallium loaded organic solvent phase from the aqueous phase.

Coleman, J.P.; Graham, C.R.; Monzyk, B.F.

1988-05-03

353

Vapor Pressure and Solvent Vapor Hazards  

Microsoft Academic Search

This paper discusses applications of vapor pressure to industrial hygiene. Vapor pressure is the quantitative term characterizing solvent volatility; it is also equivalent to the concentration of solvent vapor at the liquid surface. The ratio between this concentration at the source and the acceptable concentration at the breathing zone is an intrinsic property of each chemical but varies over 6

WILLIAM POPENDORF

1984-01-01

354

SOLVENT RECOVERY AT VANDENBERG AIR FORCE BASE  

EPA Science Inventory

The report gives results of a feasibility study of the addition of vapor recovery and solvent purification equipment for Vandenberg Air Force Base (VAFB) to reuse the large quantities of waste solvent generated in space shuttle preparation operations. (NOTE: Operation of VAFB as ...

355

A spreadsheet algorithm for stagewise solvent extraction  

SciTech Connect

Part of the novelty is the way in which the problem is organized in the spreadsheet. In addition, to facilitate spreadsheet setup, a new calculational procedure has been developed. The resulting Spreadsheet Algorithm for Stagewise Solvent Extraction (SASSE) can be used with either IBM or Macintosh personal computers as a simple yet powerful tool for analyzing solvent extraction flowsheets.

Leonard, R.A.; Regalbuto, M.C.

1993-01-01

356

Remediating pesticide contaminated soils using solvent extraction  

SciTech Connect

Bench-scale solvent extraction studies were performed on soil samples obtained from a Superfund site contaminated with high levels of p,p{prime}-DDT, p,p{prime}-DDE and toxaphene. The effectiveness of the solvent extraction process was assessed using methanol and 2-propanol as solvents over a wide range of operating conditions. It was demonstrated that a six-stage methanol extraction using a solvent-to-soil ratio of 1.6 can decrease pesticide levels in the soil by more than 99% and reduce the volume of material requiring further treatment by 25 times or more. The high solubility of the pesticides in methanol resulted in rapid extraction rates, with the system reaching quasi-equilibrium state in 30 minutes. The extraction efficiency was influenced by the number of extraction stages, the solvent-to-soil ratio, and the soil moisture content. Various methods were investigated to regenerate and recycle the solvent. Evaporation and solvent stripping are low cost and reliable methods for removing high pesticide concentrations from the solvent. For low concentrations, GAC adsorption may be used. Precipitating and filtering pesticides by adding water to the methanol/pesticide solution was not successful when tested with soil extracts. 26 refs., 10 figs., 6 tabs.

Sahle-Demessie, E.; Meckes, M.C.; Richardson, T.L. [National Management Research Lab., Cincinnati, OH (United States)

1996-12-31

357

SCENARIOS EVALUATION TOOL FOR CHLORINATED SOLVENT MNA  

Microsoft Academic Search

Over the past three decades, much progress has been made in the remediation of chlorinated solvents from the subsurface. Yet these pervasive contaminants continue to present a significant challenge to the U.S. Department of Energy (DOE), other federal agencies, and other public and private organizations. The physical and chemical properties of chlorinated solvents make it difficult to rapidly reach the

K Vangelas; Michael J. Truex; Charles J. Newell

2006-01-01

358

SOLVENT DESIGN UNDER VARYING ENVIRONMENTAL REQUIREMENTS  

EPA Science Inventory

There is currently a great need to replace many solvents that are commonly used by industry and the public, but whose continued use entails a number of human health and environmental risks. One issue hampering solvent replacement is the general thought that replacement, particul...

359

Coordination effects on the electronic structure of the CuA site of cytochrome c oxidase  

NASA Astrophysics Data System (ADS)

The CuA site is the electron mediator in cytochrome c oxidase (CcO), providing an appropriate electronic structure for rapid electron transfer. We have studied the coordinating effects of His, Met, and the peptide carbonyl group of Glu of the CuA site, using the density functional theory. Our computation demonstrates that the His ligation provides strong orbital and electrostatic effects on the electronic structure of the CuA site, while that the Met coordination gives weak orbital and electrostatic effects. A coordination of the peptide carbonyl group affects the electronic structure of the CuA site only electrostatically.

Koizumi, Kenichi; Shigeta, Yasuteru; Okuyama, Orio; Nakamura, Haruki; Takano, Yu

2012-04-01

360

Coordination of W(CO)5 to DNA and RNA nucleobases: development of a possible heavy-metal labeling complex  

Microsoft Academic Search

Photolysis of W(CO)6 in acetone solvent in the presence of DNA\\/RNA nucleobases attached to their ribose sugars has revealed attachment of the W(CO)5 moiety at N-7, N-1 and N-3 for both guanosine (G) and adenosine (A). Cytidine (C) coordinates only at N-3. Thymidine (T) and uridine (U) do not coordinate via a pyrimidine site, but engage in attack at the

Thomas W. Stringfield; Rex E. Shepherd

1999-01-01

361

Effects of solvent polarity and hydrogen bonding on the fluorescence properties of trans-4-hydroxy-4?-nitrostilbenes  

NASA Astrophysics Data System (ADS)

The excited singlet state properties of 4'-nitro- and 2',4'-dinitro-substituted trans-4-hydroxystilbenes were studied in various solvents. The fluorescence quantum yield ( ?f) of the former compound in solvents unable to form strong hydrogen bonds goes through a maximum as a function of the solvent polarity parameter ETN, reaching the highest value of 0.31 in butyronitrile. In contrast, a monotonous diminution of ?f and moderate changes were found in hydrogen bonding media. The addition of nitrogen-heterocyclic compounds leads to both dynamic and static fluorescence quenching due to excited-state proton transfer along the hydrogen bond. trans-2',4'-Dinitro-4-hydroxystilbene emits only weak fluorescence in all solvents studied.

Megyesi, Mónika; Biczók, László; Görner, Helmut; Miskolczy, Zsombor

2010-04-01

362

Toxic hepatitis in occupational exposure to solvents  

PubMed Central

The liver is the main organ responsible for the metabolism of drugs and toxic chemicals, and so is the primary target organ for many organic solvents. Work activities with hepatotoxins exposures are numerous and, moreover, organic solvents are used in various industrial processes. Organic solvents used in different industrial processes may be associated with hepatotoxicity. Several factors contribute to liver toxicity; among these are: species differences, nutritional condition, genetic factors, interaction with medications in use, alcohol abuse and interaction, and age. This review addresses the mechanisms of hepatotoxicity. The main pathogenic mechanisms responsible for functional and organic damage caused by solvents are: inflammation, dysfunction of cytochrome P450, mitochondrial dysfunction and oxidative stress. The health impact of exposure to solvents in the workplace remains an interesting and worrying question for professional health work.

Malaguarnera, Giulia; Cataudella, Emanuela; Giordano, Maria; Nunnari, Giuseppe; Chisari, Giuseppe; Malaguarnera, Mariano

2012-01-01

363

Efficient cellulose solvent: quaternary ammonium chlorides.  

PubMed

Pure quaternary tetraalkylammonium chlorides with one long alkyl chain dissolved in various organic solvents constitute a new class of cellulose solvents. The electrolytes are prepared in high yields and purity by Menshutkin quaternization, an inexpensive and easy synthesis route. The pure molten tetraalkylammonium chlorides dissolve up to 15 wt% of cellulose. Cosolvents, including N,N-dimethylacetamide (DMA), may be added in large excess, leading to a system of decreased viscosity. Contrary to the well-established solvent DMA/LiCl, cellulose dissolves in DMA/quaternary ammonium chlorides without any pretreatment. Thus, the use of the new solvent avoids some disadvantages of DMA/LiCl and ionic liquids, the most extensively employed solvents for homogeneous cellulose chemistry. PMID:24014114

Kostag, Marc; Liebert, Tim; El Seoud, Omar A; Heinze, Thomas

2013-09-09

364

Reorganization of Defense Coordinating Officer and Element.  

National Technical Information Service (NTIS)

The organization of Defense Coordinating Officers (DCOs) and Defense Coordinating Elements (DCEs) in 2005 impeded coordination and interagency cooperation during the federal response to Hurricane Katrina. In 2006, the program was reorganized to improve th...

T. L. Schilling

2012-01-01

365

75 FR 81232 - Council Coordination Committee Meeting  

Federal Register 2010, 2011, 2012, 2013

...Administration RIN 0648-XA101 Council Coordination Committee Meeting AGENCY: National...will host a meeting of the Council Coordination Committee (CCC), consisting of the...MSRA) of 2006 established the Council Coordination Committee (CCC) by amending...

2010-12-27

366

78 FR 7757 - Council Coordination Committee Meeting  

Federal Register 2010, 2011, 2012, 2013

...Administration RIN 0648-XC475 Council Coordination Committee Meeting AGENCY: National...will host a meeting of the Council Coordination Committee (CCC), consisting of the...MSRA) of 2006 established the Council Coordination Committee (CCC) by amending...

2013-02-04

367

7 CFR 22.201 - Coordination.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Coordination. 22.201 Section 22.201...Agriculture RURAL DEVELOPMENT COORDINATION Roles and Responsibilities of Federal Government § 22.201 Coordination. The following identifies...

2010-01-01

368

7 CFR 22.201 - Coordination.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Coordination. 22.201 Section 22.201...Agriculture RURAL DEVELOPMENT COORDINATION Roles and Responsibilities of Federal Government § 22.201 Coordination. The following identifies...

2009-01-01

369

76 FR 79151 - Forest Resource Coordinating Committee  

Federal Register 2010, 2011, 2012, 2013

...comments received on the Forest Resource Coordinating...www.fs.fed.us/spf/coop/. Visitors...CONTACT: Maya Solomon, Forest Resource Coordinating...meeting may be found on the Forest Resource Coordinating...www.fs.fed.us/spf/coop/)....

2011-12-21

370

Coordinating Human Services Delivery in Rhode Island.  

National Technical Information Service (NTIS)

This report discusses some theoretical aspects of service delivery coordination in Rhode Island, examines coordination projects undertaken by other States, presents an overview of coordination efforts in Rhode Island, evaluates results of a special survey...

G. J. Beiser

1979-01-01

371

47 CFR 27.57 - International coordination.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false International coordination. 27.57 Section... Technical Standards § 27.57 International coordination. (a) WCS operations...in WCS spectrum shall be subject to international satellite coordination...

2011-10-01

372

Specific binding of ethanol to cholesterol in organic solvents.  

PubMed Central

Although ethanol has been reported to affect cholesterol homeostasis in biological membranes, the molecular mechanism of action is unknown. Here, nuclear magnetic resonance (NMR) spectroscopic techniques have been used to investigate possible direct interactions between ethanol and cholesterol in various low dielectric solvents (acetone, methanol, isopropanol, DMF, DMSO, chloroform, and CCl(4)). Measurement of (13)C chemical shifts, spin-lattice and multiplet relaxation times, as well as self-diffusion coefficients, indicates that ethanol interacts weakly, yet specifically, with the HC-OH moiety and the two flanking methylenes in the cyclohexanol ring of cholesterol. This interaction is most strong in the least polar-solvent carbon tetrachloride where the ethanol-cholesterol equilibrium dissociation constant is estimated to be 2 x 10(-3) M. (13)C-NMR spin-lattice relaxation studies allow insight into the geometry of this complex, which is best modeled with the methyl group of ethanol sandwiched between the two methylenes in the cyclohexanol ring and the hydroxyl group of ethanol hydrogen bonded to the hydroxyl group of cholesterol.

Daragan, V A; Voloshin, A M; Chochina, S V; Khazanovich, T N; Wood, W G; Avdulov, N A; Mayo, K H

2000-01-01

373

ON THE EFFECT OF A WEAK INTERPLANETARY MAGNETIC FIELD ON THE INTERACTION BETWEEN THE SOLAR WIND AND THE GEOMAGNETIC FIELD  

Microsoft Academic Search

the presence of a weak interplanetary magnetic field may lead to the ; formation of a collision-free shock wave upstream from the boundary of the ; geomagnetic field and to a transition region characterized by an irregular ; magnetic field in the intervening space. Previous calculations of the ; coordinates of the shock wave are improved upon by application of

John R. Spreiter; Wm. Prichard Jones

1963-01-01

374

PARIS II: Computer Aided Solvent Design for Pollution Prevention  

EPA Science Inventory

This product is a summary of U.S. EPA researchers' work developing the solvent substitution software tool PARIS II (Program for Assisting the Replacement of Industrial Solvents, version 2.0). PARIS II finds less toxic solvents or solvent mixtures to replace more toxic solvents co...

375

COORDINATION AS ENERGY-IN- CONVERSATION  

Microsoft Academic Search

Coordination is the process people use to create, adapt, and re-create organizations. We propose a theory of coordination as energy-in-conversation to help organizational scholars comprehend the emotional and motivational dynamics of coordination. Our model describes how people generate and diminish their energy in their attempts to coordinate, how this energy affects attempts to coordinate, and how coordinating affects the effort

RYAN W. QUINN; JANE E. DUTTON

2005-01-01

376

Generalized Equations for the Inertial Tensor of a Weakly Bound Complex  

NASA Astrophysics Data System (ADS)

A variety of methods have been employed for deriving intermolecular structural parameters from observed rotational constants of weakly bound complexes. Among these are methods that use formulas expressing the moments of inertia of the complex in terms of intermolecular coordinates and the known moments of inertia of the free monomers. While such formulas are available for a number of specific geometries, general forms have not been given. In this talk, equations are presented for the inertial tensor components of a weakly bound complex in terms of intermolecular coordinates and moments of inertia of the individual moieties. The result is a generalization of similar equations existing in the literature and allows for the use of up to three angles to specify the orientation of an asymmetric rotor within a complex. The angles used are well suited to treating the large amplitude motion characteristic of weakly bound systems and the resulting expressions should be useful in the analysis of the rotational constants of weakly bound systems with complicated geometries.

Leopold, Kenneth R.

2013-06-01

377

Solvent?Free Reactions of Fullerenes with Diethyl Bromomalonate in the Presence of Inorganic Bases Under High?Speed Vibration Milling Conditions  

Microsoft Academic Search

Solvent?free reactions of C60 and C70 with diethyl bromomalonate in the presence of various inorganic bases were investigated under the high?speed vibration milling (HSVM) conditions, and are shown to give methanofullerenes 1 and 2 in good to excellent yields based on consumed fullerenes. Several weak inorganic bases were found to be quite effective in promoting the solvent?free mechanochemical Bingel reactions

Yasujiro Murata; Koichi Komatsu

2004-01-01

378

Solvent extraction of coal with dimethylsulfoxide and other solvent blends at low temperatures  

SciTech Connect

Solvent extraction of coal with dimethylsulfoxide (DMSO) and solvent blends such as DMSO/tetralin and DMSO/carbon disulfide (CS{sub 2}) was performed at atmospheric pressure under the boiling point of solvents. Extract and solvent were separated from coal residue by filtration. Residue and extract were then analyzed. Experimental data show that DMSO is an active solvent which can extract about 30 wt% of Kittaning coal at 320 F. Tetralin and carbon disulfide alone are not active solvents. However when blended with DMSO, they increase the extraction yield. Over 45 wt% of Bakerstown coal was extracted by DMSO/tetralin (1:4 vol) in six consecutive extractions at 320 F. About 25 wt% of Bakerstown coal was extracted by DMSO/CS{sub 2} (1:1 vol) at room temperature. The presence of additives, such as cumene, quinone, and hydroquinone, drastically reduces the extraction yield due to the interactions between the additives and the active solvents. In general, extraction yield is affected by type of coal, the composition of the solvent, extraction temperature, the number of consecutive extractions, and the particle size of coal. The solvent extraction of coal can be hypothesized as a three-stage process which includes penetration of solvent, swelling of the coal by solvent and solvation and removal of coal fragments from the coal matrix. A rationale for this hypothesis is presented and compared to present experimental results and literature results.

Tsao, I.H.

1988-01-01

379

Simulant flowsheet test with modified solvent for cesium removal using caustic-side solvent extraction.  

SciTech Connect

A modified solvent has been developed at Oak Ridge National laboratory (ORNL) for a caustic-side solvent extraction (CSSX) process that removes cesium (Cs) from Savannah River Site (SRS) tank waste. The modified solvent was evaluated using the same CSSX flowsheet, SRS simulant, and 33-stage minicontactor (2-cm centrifugal contactor) that had been used to test the previous CSSX solvent. As with the previous solvent, the key process goals were achieved: (1) the Cs was removed from the waste with decontamination factors greater than 40,000 and (2) the recovered Cs was concentrated by a factor of 15 in dilute nitric acid. Thus, the modified CSSX solvent can be used in place of the previous solvent while maintaining satisfactory hydraulic performance and still achieving process requirements at the bench scale.

Leonard, R. A.; Aase, S. B.; Arafat, H. A.; Conner, C.; Falkenberg, J. R.; Regalbuto, M. C.; Vandegrift, G. F.

2002-07-15

380

AN ACCELERATED RATE CALORIMETRY STUDY OF CAUSTIC-SIDE SOLVENT EXTRACTION SOLVENT WITHOUT EXTRACTANT  

SciTech Connect

This study found that 4 - 48 part per thousand (ppth) of Caustic Side Solvent Extraction (CSSX) solvent without extractant in caustic salt solution at evaporator-relevant temperatures result in no process-significant energetic events. However, the data suggest a chemical reaction (possible decomposition) in the CSSX solvent near 140 C. This concentration of entrained solvent is believed to markedly exceed the amount of solvent that will pass from the Modular Caustic Side Solvent Unit (MCU) through the downstream Defense Waste Processing Facility and enter the evaporator through routine tank farm operations. The rate of pressure rise at 140 C differs appreciably - i.e., is reduced - for salt solution containing the organic from that of the same solution without solvent. This behavior is due to a reaction between the CSSX components and the salt solution simulant.

Fondeur, F; Samuel Fink, S

2006-03-07

381

Hydrogenolysis in coal liquefaction and pyrolysis: the relative importance of solvent radicals and free hydrogen atoms  

SciTech Connect

In this paper we wish to further support our contention that a significant part of the structural fragmentation occuring during coal liquefaction is not ''spontaneous'', but results from a previously undocumented fundamental reaction, '' radical-hydrogen-transfer'' (RHT), to aromatic positions bearing aliphatic (or ether) linkages in the coal structures (reaction 1). It is no longer at issue whether alternatives to thermal scission of inherently weak bonds exist under donor solvent coal liquefaction conditions: The observed cleavage of very strong alkyl-aryl bonds in hydroaromatic media, at 400C, in the absence of H2 pressure, on coal liquefaction time scales, (reaction 2) has demonstrated that what are formally defined as hydrogenolyses do take place under conditions where free hydrogen atoms have been thought to be unimportant. The fundamentally intriguing and possibly technologically important question that remains is whether or not this cleavage simply involves the ipso addition of free hydrogen atoms, and if does not, then by what mechanism does it take place. In order to help answer the above question, we wish to present results that (1) demonstrate the relative importance of free hydrogen atoms and solvent ''hydrogen-carrier radicals'' for bond scission in the donor solvent system most likely (of those systems generally studied) to generate ''free'' hydrogen atoms, and (2) suggest the relative importance of the two transfer modes for solvent systems that are much less likely to generate free hydrogen atoms (and not coincidentally are better coal liquefaction solvents). 16 refs., 1 tab.

McMillen, D.F.; Malhotra, R.; Chang, S.J.; Nigenda, S.E.

1985-01-01

382

Evaluation of vertical coordinate and vertical mixing algorithms in the HYbrid-Coordinate Ocean Model (HYCOM)  

Microsoft Academic Search

Vertical coordinate and vertical mixing algorithms included in the HYbrid Coordinate Ocean Model (HYCOM) are evaluated in low-resolution climatological simulations of the Atlantic Ocean. The hybrid vertical coordinates are isopycnic in the deep ocean interior, but smoothly transition to level (pressure) coordinates near the ocean surface, to sigma coordinates in shallow water regions, and back again to level coordinates in

George R. Halliwell

2004-01-01

383

Does Oil Cause Civil War Because It Causes State Weakness?  

Microsoft Academic Search

Conflict scholars have devoted considerable attention to the natural resource curse, and specifically to connections between natural resources, state weakness, and civil war. Many have posited a state weakness mechanism- that significant oil production causes state weakness, and state weakness consequently increases the likelihood of civil war onset. Using standard measures, this paper demonstrates that the state weakness mechanism does

Adam N. Glynn

384

Transient absorption spectroscopy of bacteriochlorophyll a: Cation radical generated in solvents forming aggregates and T[sub 1] species generated in solvents forming penta- and hexacoordinated monomers with and without hydrogen bonding  

SciTech Connect

Transient absorption spectra of bacteriochlorophyll a were recorded at room temperature in 16 different solvents 200 ns after excitation. The cation radical was found in carbon tetrachloride forming higher aggregates, both the cation radical and the T[sub 1] species were found in methylene chloride forming lower aggregates, and the T[sub 1] species was found in the rest of the solvents forming monomers. Thus, the cation radical can be formed in the aggregates upon photoexcitation. The T[sub 1] [yields] T[sub n] absorption spectra exhibited the following solvent effects: (1) In non-hydrogen-bonding solvents, the lowest-energy peak shifted to the lower energies upon transformation from the penta- to hexacoordinated state. (2) In hydrogen-bonding solvents (alcohols), the transformation caused the low-energy shifts of the lower three peaks as well as the appearance of a new split peak. (3) Replacement of a non-hydrogen-bonding solvent by a hydrogen-bonding solvent, in the same state of coordination, also caused the low-energy shifts of the above absorption peaks. 19 refs., 4 figs., 2 tabs.

Nishizawa, E.; Koyama, Y. (Kwansei Gakuin Univ., Nishinomiya (Japan)); Nagae, H. (Kobe City Univ. of Foreign Studies (Japan))

1994-11-17

385

A weak component approach of subspace analysis  

NASA Astrophysics Data System (ADS)

In the linear discriminative analysis, especially in the high dimension case, it is insufficient to project the data onto a one-dimensional subspace for the two-category classification problem. Therefor a weak component approach (WCA) was proposed to project patterns to a low dimensional subspace with rich number of classification features. The role of the weak component in pattern classification was discussed. And the abundance of discriminative information contained in weak components was explored. Firstly, a definition of the weak component was given. Secondly, an improved regularization method was proposed. The regularization is a biased estimate of the variance in the corresponding dimension of the training data and the population data. Then a construction method of the feature subspace based on weak component was given, which extracts the eigenvector of the scatter matrixes according to their discriminative information. Finally, the proposed approach was validated in the experiments by comparing it with LDA. A better classification accuracy of the presented method was achieved. As WCA extracts the dims on which the data distributes closer, it is applicable to the high-dimensional data which distributes elliptically.

Pu, Lijuan; Xie, Weixin; Pei, Jihong

2011-11-01

386

Weak turbulence theory for reactive instability  

SciTech Connect

In the present paper, the customary weak turbulence theory is generalized to include reactive instabilities. For the sake of simplicity, the formalism assumes electrostatic perturbation propagating in one-dimensional uniform unmagnetized plasmas. By weak turbulence theory it is meant as the perturbative nonlinear theory based upon Vlasov equation, truncated at the second (or up to third) order nonlinearity and ensemble averaged. By reactive instability it is meant as the plasma instability whose growth rate is not necessarily exceedingly small. The traditional weak turbulence theory found in the literature is applicable only to weakly growing plasma instabilities whose real frequency {omega}{sub k} can be determined from the real part of the dispersion relation, Re {epsilon}(k,{omega}{sub k})=0, while the growth rate may be determined by the Landau formula, {gamma}{sub k}=-Im {epsilon}(k,{omega}{sub k})[{partial_derivative} Re {epsilon}(k,{omega}{sub k})/{partial_derivative}{omega}{sub k}]{sup -1}. This implies the assumption that |{gamma}{sub k}|<<{omega}{sub k}. On the other hand, for reactive instabilities for which {gamma}{sub k}/{omega}{sub k} is not necessarily small, the real frequency and growth/damping rate must be determined from the complex roots of the dispersion relation, {epsilon}(k,{omega}{sub k}+i{gamma}{sub k})=0. The present paper extends the textbook weak turbulence theory to deal with such a situation.

Yoon, P. H. [IPST, University of Maryland, College Park, Maryland 20742-2431 (United States)

2010-11-15

387

Coordinate-Space Hartree-Fock-Bogoliubov Description of Superfluid Fermi Systems  

SciTech Connect

Properties of strongly interacting, two-component finite Fermi systems are discussed within the recently developed coordinate-space Hartree-Fock-Bogoliubov (HFB) code HFB-AX. Two illustrative examples are presented: (i) weakly bound deformed Mg isotopes, and (ii) spin-polarized atomic condensates in a strongly deformed harmonic trap.

Pei, Junchen [ORNL; Nazarewicz, Witold [ORNL; Stoitsov, Mario [ORNL

2009-01-01

388

40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Default Organic HAP Contents of Solvents and Solvent Blends...to Subpart VVVV of Part 63âDefault Organic HAP Contents of Solvents and Solvent Blends...63.5758(a)(6), when detailed organic HAP content data for solvent blends...

2012-07-01

389

Solvent exposure in construction and maintenance painting.  

PubMed

Exposure to solvents in interior house painting was determined by industrial hygiene surveys and questionnaires on work history. Painting work was observed in 92 work situations at 18 sites, mainly during maintenance work. The effects of the size of the work area, the volume of air, the type of paint, the amount used, the method of application, and the use of ventilation on the solvent concentrations were also studied. In small, poorly ventilated rooms the concentration of solvent naphtha averaged 275 ppm when alkyd paints were used. Wall and ceiling painting with alkyd paints yielded an average solvent naphtha concentration of 210 ppm, and window and door painting 80 ppm. The presence of a strong draft reduced the solvent concentrations by two-thirds. The painters' average lifetime dose of solvent naphtha was 12.2 kg, the average annual dose 0.54 kg. These levels decreased over the study period. The mean 8-h concentration of solvent naphtha in the breathing zone averaged 40 ppm over the painters' total worklife. PMID:6494847

Riala, R; Kalliokoski, P; Pyy, L; Wickström, G

1984-08-01

390

Application of Möbius coordinate transformation in evaluating Newton's integral  

NASA Astrophysics Data System (ADS)

We propose a numerical scheme which efficiently combines various existing methods of solving the Newton's volume integral. It utilises the analytical solution of Newton's integral for tesseroid in computing the near-zone contribution to gravitational field quantities (potential and its first radial derivative). The far-zone gravitational contribution is computed using the expressions derived based on applying Molodensky's truncation coefficients to a spectral representation of Newton's integral. The weak singularity of Newton's integral is treated analytically using formulas for the gravitational contribution of the cylindrical mass volume centered with respect to the observation point. All three solutions are defined and evaluated in the system of polar spherical coordinates. A conversion of the geographical to polar spherical coordinates of input data sets (digital terrain and density models) is based on the Möbius transformation with an enhanced integration grid resolution at vicinity of the observation point.

Tenzer, Robert; Gladkikh, Vladislav

2011-01-01

391

Effect of solvent characteristics on coal liquefaction  

SciTech Connect

It has been known for a long time that the characteristics of the liquefaction solvent has a profound effect on direct coal liquefaction. The amount of hydrogen consumed during the liquefaction process, the degree and quantity of retrograde reactions that occur, and the quality of the liquid products are all influenced by the process solvent. A number of analytical approaches have been developed to determine the important characteristics of the solvent for coal liquefaction. The hydrogen donor ability has clearly been important. However, such other characteristics of a liquefaction solvent as solubility parameter, content and type of higher aromatic hydrocarbons, and phenolic content have also been found to be significant. Finseth et al. have shown that the bulk of the hydrogen consumed from an uncatalyzed donor solvent liquefaction above 400{degrees}C is consumed in gas generation, heteroatom removal and hydrogenolysis of the coal matrix. Wilson et al. have also shown that the major role of hydrogen in uncatalyzed liquefaction is consumed by alkyl fission and hydrogenolysis reactions and not with hydrogenating aromatic rings. McMillan et al. have postulated that a radical hydrogen transfer process along with donor solvent capping of thermally produced radicals from the coal as possible processes involved with the hydroaromatic donor solvents in coal liquefaction. With the development of a short contact time batch reactor (SCTBR), determining the influence of the processing solvent on the liquefaction rates, conversion profiles and the quality of the liquid product at a particular time became possible. The influence of type of solvent, combined with other effects, such as gas atmosphere (i.e., in hydrogen and in nitrogen) and catalyst, on the coal liquefaction is reported in this paper.

Huang, He; Wang, Shaojie; Wang, Keyu; Klein, M.T.; Calkins, W.H. [Univ. of Delaware, Newark, DE (United States)

1996-12-31

392

Weak layer fracture: facets and depth hoar  

NASA Astrophysics Data System (ADS)

Understanding failure initiation within weak snow layers is essential for modeling and predicting dry-snow slab avalanches. We therefore performed laboratory experiments with snow samples containing a weak layer consisting of either faceted crystals or depth hoar. During these experiments the samples were loaded with different loading rates and at various tilt angles until fracture. The strength of the samples decreased with increasing loading rate and increasing tilt angle. Additionally, we took pictures of the side of four samples with a high-speed video camera and calculated the displacement using a particle image velocimetry (PIV) algorithm. The fracture process within the weak layer could thus be observed in detail. Catastrophic failure started due to a shear fracture just above the interface between the depth hoar layer and the underlying crust.

Reiweger, I.; Schweizer, J.

2013-09-01

393

The strong side of weak topological insulators  

NASA Astrophysics Data System (ADS)

Three-dimensional topological insulators are classified into ``strong'' (STI) and ``weak'' (WTI) according to the nature of their surface states. While the surface states of the STI are topologically protected, in the WTI they are believed to be very fragile to disorder. In this work we show that the WTI surface states are actually protected from any random perturbation which does not break time-reversal symmetry, and does not close the bulk energy gap. Consequently, the conductivity of metallic surfaces in the clean system will remain finite even in the presence of strong disorder of this type. In the weak disorder limit the surfaces are perfect metals, and strong surface disorder only acts to push them inwards. We find that WTI's differ from STI's primarily in their anisotropy, and that the anisotropy is not a sign of their weakness but rather of their richness.

Kraus, Yaacov; Ringel, Zohar; Stern, Ady

2012-02-01

394

Strong side of weak topological insulators  

NASA Astrophysics Data System (ADS)

Three-dimensional topological insulators are classified into “strong” (STI) and “weak” (WTI) according to the nature of their surface states. While the surface states of the STI are topologically protected from localization, this does not hold for the WTI. In this work, we show that the surface states of the WTI are actually protected from any random perturbation that does not break time-reversal symmetry, and does not close the bulk energy gap. Consequently, the conductivity of metallic surfaces in the clean system remains finite even in the presence of strong disorder of this type. In the weak disorder limit, the surfaces are found to be perfect metals, and strong surface disorder only acts to push the metallic surfaces inwards. We find that the WTI differs from the STI primarily in its anisotropy, and that the anisotropy is not a sign of its weakness but rather of its richness.

Ringel, Zohar; Kraus, Yaacov E.; Stern, Ady

2012-07-01

395

Weak self-adjoint differential equations  

NASA Astrophysics Data System (ADS)

The concepts of self-adjoint and quasi self-adjoint equations were introduced by Ibragimov (2006 J. Math. Anal. Appl. 318 742-57 2007 Arch. ALGA 4 55-60). In Ibragimov (2007 J. Math. Anal. Appl. 333 311-28), a general theorem on conservation laws was proved. In this paper, we generalize the concept of self-adjoint and quasi self-adjoint equations by introducing the definition of weak self-adjoint equations. We find a class of weak self-adjoint quasi-linear parabolic equations. The property of a differential equation to be weak self-adjoint is important for constructing conservation laws associated with symmetries of the differential equation.

Gandarias, M. L.

2011-07-01

396

Fluoro-Carbonate Solvents for Li-Ion Cells.  

National Technical Information Service (NTIS)

A number of fluoro-carbonate solvents were evaluated as electrolytes for Li-ion cells. These solvents are fluorine analogs of the conventional electrolyte solvents such as dimethyl carbonate, ethylene carbonate, diethyl carbonate in Li-ion cells. Conducti...

Nagasubramanian

1999-01-01

397

29 CFR 1915.32 - Toxic cleaning solvents.  

Code of Federal Regulations, 2013 CFR

... 7 2013-07-01 2013-07-01 false Toxic cleaning solvents. 1915.32 Section 1915...Surface Preparation and Preservation § 1915.32 Toxic cleaning solvents. (a) When toxic solvents are used, the employer shall...

2013-07-01

398

Coordinating Education and Employment Training: A Coordinated Executive Summary.  

ERIC Educational Resources Information Center

|The Massachusetts State Council on Vocational Education advocates both articulation between secondary schools and community colleges and system coordination between education and employment training. Council projects have had two basic operational goals: to create dialogue within and between sectors and to create products that would stimulate…

Green, James

399

Galaxy coordinates. I. Accuracy of galaxy coordinates in large catalogues  

Microsoft Academic Search

Using a generalization of the triple intercomparison method introduced by de Vaucouleurs and Head we calculated the accuracy of galaxy coordinates taken from the large catalogues. The result confirms the qualitative estimation we had in mind about the different catalogues, but for the first time it will be now possible to give a quantitative estimation of the accuracy of the

G. Paturel; C. Petit

1999-01-01

400

Effects of anharmonicity on diffusive-controlled symmetric electron transfer rates: From the weak to the strong electronic coupling regions  

SciTech Connect

The approach for the diffusive-controlled electron transfer rates [W. Zhu and Y. Zhao, J. Chem. Phys. 126, 184105 (2007)], which is modeled after the Sumi-Marcus theory, is applied to symmetric electron-transfer reactions in a solvent environment with anharmonic potential functions. The electron-transfer rates are evaluated using the quantum R-matrix theory for dealing with the intramolecular vibrational motions and imaginary-time split operator technique for solving the diffusive equations, thereby taking explicit account of the weak-to-strong electronic couplings. The effect of anharmonicity for both the solvent and intramolecular vibrational degrees of freedom are investigated. It is found that the anharmonicity of the intramolecular modes always enhances the rate while the solvent anharmonicity decreases the rate, compared with the harmonic modes. The possible mechanisms have been clarified.

Zhu Wenjuan [Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Zhao Yi [State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Fujian 361005 (China)

2008-11-14

401

Firing of pulverized solvent refined coal  

DOEpatents

A burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired successfully without any performance limitations and without the coking of the solvent refined coal on the burner components. The burner is provided with a tangential inlet of primary air and pulverized fuel, a vaned diffusion swirler for the mixture of primary air and fuel, a center water-cooled conical diffuser shielding the incoming fuel from the heat radiation from the flame and deflecting the primary air and fuel steam into the secondary air, and a watercooled annulus located between the primary air and secondary air flows.

Lennon, Dennis R. (Allentown, PA); Snedden, Richard B. (McKeesport, PA); Foster, Edward P. (Macungie, PA); Bellas, George T. (Library, PA)

1990-05-15

402

Cleaning solvent substitution in electronic assemblies  

SciTech Connect

Alternatives to chlorinated and fluorinated solvents have been identified, qualified, and implemented into production of complex electronic assemblies. Extensive compatibility studies were performed with components, piece-parts, and materials. Electrical testing and accelerated aging were used to screen for detrimental, long-term effects. A terpene, d-limonene, has been selected as the solvent of choice for cleaning complex electronic assemblies, and has been found to be compatible with the components and materials tested. A brief history of the overall project will be presented, along with representative cleaning efficiency results, compatibility results, and residual solvent data.

Meier, G.J.

1993-09-01

403

What makes critical-solvent processes work  

SciTech Connect

Critical-solvent processing (sometimes called supercritical-gas extraction) is an ongoing technology based on phase-equilibrium phenomena in the critical region. Many new practical applications of critical-solvent processing are being conceived and implemented in the food, drug and chemical industries. The advantages afforded by critical-solvent processing in performing difficult separations such as caffeine from coffee, nicotine from tobacco, chemotherapeutic drugs from plants, and chemical feedstocks from petroleum and synfuels residua have been realized just in the last decade or so.

Brule, M.R.; Corbett, R.W.

1984-06-01

404

Genomic and Genetic Approaches to Solvent Tolerance  

SciTech Connect

The proposed research is to understand and exploit the molecular basis that determines tolerance of the industrially important anaerobic clostridia to solvents. Furthermore, we aim to develop general genomic and metabolic engineering strategies for understanding the molecular basis of tolerance to chemicals and for developing tolerant strains. Our hypothesis is that the molecular basis of what makes bacterial cells able to withstand high solvent concentrations can be used to metabolically engineer cells so that they can tolerate higher concentrations of solvents and related chemicals.

Eleftherios T. Papoutsakis

2005-06-10

405

TRUEX process solvent cleanup with solid sorbents  

SciTech Connect

Solid sorbents, alumina, silica gel, and Amberlyst A-26 have been tested for the cleanup of degraded TRUEX-NPH solvent. A sodium carbonate scrub alone does not completely remove acidic degradation products from highly degraded solvent and cannot restore the stripping performance of the solvent. By following the carbonate scrub with either neutral alumina or Amberlyst A-26 anion exchange resin, the performance of the TRUEX-NPH is substantially restored. The degraded TRUEX-NPH was characterized before and after treatment by supercritical fluid chromatography. Its performance was evaluated by americium distribution ratios, phase-separation times, and lauric acid distribution coefficients. 17 refs., 2 figs., 5 tabs.

Tse, Pui-Kwan; Reichley-Yinger, L.; Vandegrift, G.F.

1989-01-01

406

Molecular accessibility in solvent swelled coal  

SciTech Connect

To expand the information base on molecular accessibility in solvent swelled coal, Argonne Premium Coal Samples (APCS) were swelled in polar, basic solvents before and after moisture loss and upon air oxidation. So far studies have been reported on the changes in pore size distribution as a function of temperature when polar basic swelling solvents are used. Additional studies employing EPR spin probe techniques performed on the breaking up of the hydrogen bonding between bedding planes were later confirmed by magnetic resonance imaging at Argonne National Lab and the University of Illinois.

Kispert, L.D.

1992-11-01

407

Coordinates and the Cartesian Plane  

NSDL National Science Digital Library

The lesson begins with a short refresher lecture on how points are written in (x,y) format and orientation with the Cartesian plane axes. The lecture also covers which directions are positive and which are negative on an x-y plane. Students learn about what it means for a relation to be a function and how to determine domain and range of a set of data points. Prerequisite knowledge: Familiarity with the coordinate plane, coordinates, and equations are helpful, but not required.

VU Bioengineering RET Program, School of Engineering,; Mckelvey, Aubrey

2007-01-01

408

Tyrosinase inactivation in organic solvents.  

PubMed

The inactivation of the catecholase activity of mushroom tyrosinase was investigated under nonaqueous conditions. The enzyme was immobilized on glass beads, and assays were conducted in chloroform, toluene, amyl acetate, isopropyl ether, and butanol. The reaction components were pre-equilibrated for 2 weeks with a saturated salt solution at a water activity of 0.90. The initial reaction velocity varied between 1.3 x 10(3) mol product/((mol enzyme)(min)) in toluene and 8.7 x 10(3) mol product/((mol enzyme)(min)) in amyl acetate. The turnover number varied between 8.1 x 10(3) mol product/mol enzyme in toluene and 7.2 x 10(4) mol product/mol enzyme in amyl acetate. In each solvent, the tyrosinase reaction inactivation parameters were represented by a probabilistic model. Changes in the probability of inactivation were followed throughout the course of the reaction using a second model which relates the reaction velocity to the amount of product formed. These models reveal that the inactivation rate of tyrosinase decreases as the reaction progresses, and that the inactivation kinetics are independent of the quinone concentration in toluene, chloroform, butanol, and amyl acetate. Significant effects of quinone concentration were, however, observed in isopropyl ether. The likelihood of inactivation of the enzyme was found to be greatest toward the beginning of the reaction. In the latter phase of the reaction, inactivation probability was less and tended to remain constant until the completion of the reaction. PMID:10486131

Warrington, J C; Saville, B A

1999-11-01

409

Weak Lensing: Dark Matter, Dark Energy  

SciTech Connect

The light rays from distant galaxies are deflected by massive structures along the line of sight, causing the galaxy images to be distorted. Measurements of these distortions, known as weak lensing, provide a way of measuring the distribution of dark matter as well as the spatial geometry of the universe. I will describe the ideas underlying this approach to cosmology. With planned large imaging surveys, weak lensing is a powerful probe of dark energy. I will discuss the observational challenges ahead and recent progress in developing multiple, complementary approaches to lensing measurements.

Jain, Bhuvnesh (University of Pennsylvania)

2006-02-27

410

Dynamics of hypernuclear nonmesonic weak decay  

NASA Astrophysics Data System (ADS)

Simple and coincidence spectra of the NM weak decay of light hypernuclei have been evaluated in a systematic way for the first time. We have only considered 1N induced processes, neglecting entirely the events induced by 2N emission, as well as the effects of the FSIt's. As the theoretical frameworkwe have used the IPSM with three different parametrizations for the transition potential. The comparison with data strongly suggests that the soft ? + K exchange model could be a good starting point to describe the dynamics in the NM weak decays of s- and p-shell hypernuclei.

Krmpoti?, Franjo; Deppman, Airton; De Conti, Claudio

2012-10-01

411

Weak Lensing: Dark Matter, Dark Energy  

ScienceCinema

The light rays from distant galaxies are deflected by massive structures along the line of sight, causing the galaxy images to be distorted. Measurements of these distortions, known as weak lensing, provide a way of measuring the distribution of dark matter as well as the spatial geometry of the universe. I will describe the ideas underlying this approach to cosmology. With planned large imaging surveys, weak lensing is a powerful probe of dark energy. I will discuss the observational challenges ahead and recent progress in developing multiple, complementary approaches to lensing measurements.

412

Weak Lensing: Dark Matter, Dark Energy  

ScienceCinema

The light rays from distant galaxies are deflected by massive structures along the line of sight, causing the galaxy images to be distorted.Measurements of these distortions, known as weak lensing, provide a way of measuring the distribution of dark matter as well as the spatial geometry of the universe. I will describe the ideas underlying this approach to cosmology. With planned large imaging surveys, weak lensing is a powerful probe of dark energy. I will discuss the observational challenges ahead and recent progress in developing multiple, complementary approaches to lensing measurements.

413

Open (closed) problems in weak hadronic processes  

NASA Astrophysics Data System (ADS)

Chiral perturbation theory in the sense of the Weinberg-Gasser- Leutwyler program is presented for weak hadronic processes. It is argued that it represents a meaningful low energy field theory, which in many cases has advantages over the standard approach. Its relation with approaches which go beyond chiral perturbation theory, but rely on it, is discussed. Finally, the role of tadpoles which appear both in chiral perturbation theory and in operator product expansion of weak currents is clarified. Mailing address, Theory group DESY, Hamburg, FRG.

Guberina, Branko

1989-04-01

414

ANALYTICAL CHEMISTRY: How to Detect Weak Pairs  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. Single-molecule fluorescence spectroscopy has shed light on many biological processes, from protein folding to enzyme dynamics. However, to study weakly interacting molecules, the diffraction limit of light must be overcome. In their Perspective, Laurence and Weiss review recent "superresolution" methods that achieve smaller detection volumes, a requirement for studying weak interactions. They highlight the method of Levene et al., who achieve parallel detection of many single molecules in extremely small (zeptoliter) detection volumes.

Ted A. Laurence (University of California, Los Angeles;Department of Chemistry and Biochemistry); Shimon Weiss (University of California, Los Angeles;Department of Chemistry and Biochemistry, the Department of Physiology, David Geffen School of Medicine at UCLA, and the California Nanosystems Institute)

2003-01-31

415

Measuring the dark side (with weak lensing)  

SciTech Connect

We introduce a convenient parameterization of dark energy models that is general enough to include several modified gravity models and generalized forms of dark energy. In particular we take into account the linear perturbation growth factor, the anisotropic stress and the modified Poisson equation. We discuss the sensitivity of large-scale weak lensing surveys like the proposed DUNE satellite to these parameters (assuming systematic errors can be controlled). We find that a large-scale weak lensing tomographic survey is able to easily distinguish the Dvali-Gabadadze-Porrati model from {Lambda}CDM and to determine the perturbation growth index to an absolute error of 0.02-0.04.

Amendola, Luca [INAF/Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monteporzio Catone, Roma (Italy); Kunz, Martin; Sapone, Domenico, E-mail: amendola@mporzio.astro.it, E-mail: martin.kunz@physics.unige.ch, E-mail: domenico.sapone@physics.unige.ch [Departement de Physique Theorique, Universite de Geneve, 24 quai Ernest Ansermet, CH-1211 Geneve 4 (Switzerland)

2008-04-15

416

Nuclear weak-interaction processes in stars  

NASA Astrophysics Data System (ADS)

Recent experimental data and progress in nuclear structure modeling have led to improved descriptions of astrophysically important weak-interaction processes. This review discusses these advances and their applications to hydrostatic solar and stellar burning, to the slow and rapid neutron-capture processes, to neutrino nucleosynthesis, and to explosive hydrogen burning. Special emphasis is given to the weak-interaction processes associated with core-collapse supernovae. Despite significant progress, improvements in the modeling of these processes are still warranted and are expected to come from future radioactive ion-beam facilities.

Langanke, K.; Martínez-Pinedo, G.

2003-06-01

417

Interaction of organic solvents with protein structures at protein-solvent interface.  

PubMed

The effect of non-denaturing concentrations of three different organic solvents, formamide, acetone and isopropanol, on the structure of haloalkane dehalogenases DhaA, LinB, and DbjA at the protein-solvent interface was studied using molecular dynamics simulations. Analysis of B-factors revealed that the presence of a given organic solvent mainly affects the dynamical behavior of the specificity-determining cap domain, with the exception of DbjA in acetone. Orientation of organic solvent molecules on the protein surface during the simulations was clearly dependent on their interaction with hydrophobic or hydrophilic surface patches, and the simulations suggest that the behavior of studied organic solvents in the vicinity of hyrophobic patches on the surface is similar to the air/water interface. DbjA was the only dimeric enzyme among studied haloalkane dehalogenases and provided an opportunity to explore effects of organic solvents on the quaternary structure. Penetration and trapping of organic solvents in the network of interactions between both monomers depends on the physico-chemical properties of the organic solvents. Consequently, both monomers of this enzyme oscillate differently in different organic solvents. With the exception of LinB in acetone, the structures of studied enzymes were stabilized in water-miscible organic solvents. PMID:22760789

Khabiri, Morteza; Minofar, Babak; Brezovský, Jan; Damborský, Ji?í; Ettrich, Rudiger

2012-07-01

418

Polymer brushes in solvents of variable quality: Molecular dynamics simulations using explicit solvent  

NASA Astrophysics Data System (ADS)

The structure and thermodynamic properties of a system of end-grafted flexible polymer chains grafted to a flat substrate and exposed to a solvent of variable quality are studied by molecular dynamics methods. The macromolecules are described by a coarse-grained bead-spring model, and the solvent molecules by pointlike particles, assuming Lennard-Jones-type interactions between pairs of monomers (?pp), solvent molecules (?ss), and solvent monomer (?ps), respectively. Varying the grafting density ?g and some of these energy parameters, we obtain density profiles of solvent particles and monomers, study structural properties of the chain (gyration radius components, bond orientational parameters, etc.), and examine also the profile of the lateral pressure P?(z), keeping in the simulation the normal pressure P? constant. From these data, the reduction of the surface tension between solvent and wall as a function of the grafting density of the brush has been obtained. Further results include the stretching force on the monomer adjacent to the grafting site and its variation with solvent quality and grafting density, and dynamic characteristics such as mobility profiles and chain relaxation times. Possible phase transitions (vertical phase separation of the solvent versus lateral segregation of the polymers into ``clusters,'' etc.) are discussed, and a comparison to previous work using implicit solvent models is made. The variation of the brush height and the interfacial width of the transition zone between the pure solvent and the brush agrees qualitatively very well with corresponding experiments.

Dimitrov, D. I.; Milchev, A.; Binder, K.

2007-08-01

419

Universal reduction of effective coordination number in the quasi-one-dimensional Ising model  

NASA Astrophysics Data System (ADS)

Critical temperature of quasi-one-dimensional general-spin Ising ferromagnets is investigated by means of the cluster Monte Carlo method performed on infinite-length strips, L×? or L×L×? . We find that in the weak interchain coupling regime the critical temperature as a function of the interchain coupling is well-described by a chain mean-field formula with a reduced effective coordination number, as the quantum Heisenberg antiferromagnets recently reported by Yasuda [Phys. Rev. Lett. 94, 217201 (2005)]. It is also confirmed that the effective coordination number is independent of the spin size. We show that in the weak interchain coupling limit the effective coordination number is, irrespective of the spin size, rigorously given by the quantum critical point of a spin- 1/2 transverse-field Ising model.

Todo, Synge

2006-09-01

420

High capacity CO2 adsorption in a Mg(II)-based phosphine oxide coordination material.  

PubMed

The new porous phosphine coordination material, PCM-11, is an unusual 8,4-connected coordination polymer with an open 3-D pore structure, formed by reaction of Mg(II) with tris(para-carboxylato)triphenylphosphine oxide. The highly ionic nature of the metal-ligand bonding results in excellent thermal stability upon desolvation (>460 °C). PCM-11 is easily activated for small molecule sorption at low temperature without the requirement for solvent pre-exchange. It adsorbs 47.5 wt% CO(2) at 11.6 bar and 30 °C. PMID:21442086

Bohnsack, Alisha M; Ibarra, Ilich A; Hatfield, Peter W; Yoon, Ji Woong; Hwang, Young Kyu; Chang, Jong-San; Humphrey, Simon M

2011-03-25

421

Protonate3D: Assignment of ionization states and hydrogen coordinates to macromolecular structures  

PubMed Central

A new method, called Protonate3D, is presented for the automated prediction of hydrogen coordinates given the 3D coordinates of the heavy atoms of a macromolecular structure. Protonate3D considers side-chain “flip,” rotamer, tautomer, and ionization states of all chemical groups, ligands, and solvent, provided suitable templates are available in a parameter file. The energy model includes van der Waals, Coulomb, solvation, rotamer, tautomer, and titration effects. The results of computational validation experiments suggest that Protonate3D can accurately predict the location of hydrogen atoms in macromolecular structures. Proteins 2009. © 2008 Wiley-Liss, Inc.

Labute, Paul

2009-01-01

422

Conformation of a coarse-grained protein chain (an aspartic acid protease) model in effective solvent by a bond-fluctuating Monte Carlo simulation.  

PubMed

In a coarse-grained description of a protein chain, all of the 20 amino acid residues can be broadly divided into three groups: Hydrophobic (H) , polar (P) , and electrostatic (E) . A protein can be described by nodes tethered in a chain with a node representing an amino acid group. Aspartic acid protease consists of 99 residues in a well-defined sequence of H , P , and E nodes tethered together by fluctuating bonds. The protein chain is placed on a cubic lattice where empty lattice sites constitute an effective solvent medium. The amino groups (nodes) interact with the solvent (S) sites with appropriate attractive (PS) and repulsive (HS) interactions with the solvent and execute their stochastic movement with the Metropolis algorithm. Variations of the root mean square displacements of the center of mass and that of its center node of the protease chain and its gyration radius with the time steps are examined for different solvent strength. The structure of the protease swells on increasing the solvent interaction strength which tends to enhance the relaxation time to reach the diffusive behavior of the chain. Equilibrium radius of gyration increases linearly on increasing the solvent strength: A slow rate of increase in weak solvent regime is followed by a faster swelling in stronger solvent. Variation of the gyration radius with the time steps suggests that the protein chain moves via contraction and expansion in a somewhat quasiperiodic pattern particularly in strong solvent. PMID:18517417

Pandey, R B; Farmer, B L

2008-03-05

423

ENHANCING PERFORMANCE THROUGH IMPROVED COORDINATION (EPIC)  

Microsoft Academic Search

Enhancing Performance through Improved Coordination (EPIC) is an approach to improving team performance that emphasizes identifying potential threats to coordination such as heavy workload, accelerated op tempo, or off- nominal states. Our long-term interest is in creating a coordination-aware system to promote better team performance by modeling situational properties and their relationship to crew coordination. Our current investigations focus on

Benjamin Bell; Jennifer Fowlkes; John Deaton

2003-01-01

424

Novel coordinate system for Gaussian beam reflection.  

PubMed

A novel coordinate system for Gaussian beam reflection has been proposed in this Letter. Reflection from a spherical mirror is used to describe the novel coordinate system. One single segment of a general resonator is chosen to describe coordinate rotation in detail. Nonplanar ring resonators are chosen to show the application of the novel coordinate system. This novel coordinate system has been proved by two simple experiments and the problem existing in using the traditional coordinate system has been pointed out. This novel coordinate system is valuable for not only the designing of laser resonators but also Gaussian beam propagation analysis. PMID:22660128

Yuan, Jie; Chen, Meixiong; Kang, Zhenglong; Long, Xingwu

2012-06-01

425

SOLVENT-FREE ORGANIC SYNTHESES USING MICROWAVES  

EPA Science Inventory

An expeditious solvent-free approach for organic synthesis is described which involves simple exposure of neat reactants to microwave (MW) irradiation. A variety of cleavage, condensation, cyclization, oxidation and reduction reactions will be presented including the efficient o...

426

Control over microemulsions with solvent blends.  

PubMed

The effect of solvent mixtures on the phase behavior of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) stabilized water-in-oil microemulsions has been studied by using heptane/dodecane, decane/dodecane, octane/dodecane, and nonane/undecane blends. Small-angle neutron scattering was employed to explore the effect of changing the solvent composition on the microemulsion properties, especially near the cloud point (T(cloud)) and the liquid-liquid critical separation (T(crit)). It is shown that droplet interactions can be strongly influenced by changing the solvent blend compostion, which has implications for the locations of observed phase boundaries. Of particular interest is the use of carefully selected solvent blends, which have the effect of lowering T(crit) by up to 6 degrees C from the value found in pure decane. PMID:19437754

Myakonkaya, Olesya; Eastoe, Julian; Mutch, Kevin J; Rogers, Sarah; Heenan, Richard; Grillo, Isabelle

2009-03-01

427

LOVA Propellant Aging: Effect of Residual Solvent.  

National Technical Information Service (NTIS)

An investigation of LOVA propellant aging was performed to identify the cause of stabilization periods in certain propellant lots. The following results were obtained: (1) the level of residual solvent in propellant grains slowly decreases while in storag...

R. A. Pesce-Rodriguez R. A. Fifer

1994-01-01

428

Reduction of solvent use through fluxless soldering.  

National Technical Information Service (NTIS)

Conventional soldering typically requires fluxing to promote wetting. Halogenated solvents must then be used to remove the flux residues. While such practice has been routinely accepted throughout the DOE weapons complex, new environmental laws and agreem...

F. M. Hosking

1990-01-01

429

Nonvolatile residue solvent replacement. Technical report  

SciTech Connect

Control of contamination during processing and integration of spacecraft and launch vehicles is fundamental to ensuring mission performance and longevity. Molecular contamination, or nonvolatile residue (NVR), is limited by selection of materials and the control of procedures and facilities. Tests to diagnose NVR accretion in clean rooms and on spacecraft surfaces rely on toxic and ozone-depleting solvents (methylene chloride and 1,1,1 trichloroethane). This report documents literature review and laboratory experimentation to identify a replacement for these undesirable materials. Two clear candidates for a replacement NVR solvent emerge from the testing reviewed and reported here: ethyl acetate and ethyl acetate/cyclohexane azeotrope. For laboratory operations that must rely on procuring high purity solvents, pure ethyl acetate is recommended. For large laboratories that are equipped to purify their own solvents, the mixture is a good option.

Arnold, G.S.; Uht, J.C.

1995-03-01

430

Deasphalted oil: A natural asphaltene solvent  

SciTech Connect

Asphaltene deposition in the near-wellbore region can block pore throats, change wettability characteristics and relative-permeability relationships, and therefore, reduce oil production. Conventional aromatic solvents (e.g., toluene and xylene) alone or in combination with various dispersants are used to remove asphaltene damage from the near-wellbore region. However, these aromatic solvents are expensive and are not environmentally friendly. The objective of this work was to systematically evaluate the asphaltene-solvating power of various nonconventional solvents, including deasphalted oil, using a light-scattering technique. Experimental results suggest that deasphalted oil is a strong asphaltene solvent presumably because of its native resin and aromatic contents. Addition of asphaltene dispersants also increases the solubilizing power of the deasphalted oil. Furthermore, various refinery and heavy oil upgrader streams show strong ability to solubilize asphaltenes.

Jamaluddin, A.K.M. [Noranda Technology Centre, Pointe Claire, Quebec (Canada); Nazarko, T.W.; Sills, S. [Norcen Energy Resources Ltd., Calgary, Alberta (Canada); Fuhr, B.J. [Alberta Research Council, Edmonton, Alberta (Canada)

1996-08-01

431

Biological monitoring of chlorinated hydrocarbon solvents  

SciTech Connect

The possibility of biological monitoring of exposure to some volatile, halogenated hydrocarbons will be discussed. Most of these agents are widely used as solvents. All agents act on the nervous system as narcotics and differ widely in toxicity. Most of the solvents undergo biotransformation to metabolites. This allows biological assessment of exposure by measurement of the solvent and/or metabolites in exhaled air, blood, and/or urine. However, the same metabolites may occur with exposure to different chlorinated hydrocarbons, eg, trichloroethanol and trichloroacetic acid from exposure to trichloroethene, tetrachloroethene, and 1,1,1-trichloroethane. On the other hand, these agents differ widely in the percentage that is metabolized. There are large gaps in our knowledge, however, and much research will have to be carried out before even tentative data can be established for most of the solvents.

Monster, A.C.

1986-08-01

432

Used lubricating oil recycling using hydrocarbon solvents.  

PubMed

A solvent extraction process using new hydrocarbon solvents was employed to treat used lubricant oil. The solvents used were liquefied petroleum gas (LPG) condensate and stabilized condensate. A demulsifier was used to enhance the treatment process. The extraction process using stabilized condensate demonstrated characteristics that make it competitive with existing used oil treatment technologies. The process is able to reduce the asphaltene content of the treated lubricating oil to 0.106% (w/w), the ash content to 0.108%, and the carbon residue to 0.315% with very low levels of contaminant metals. The overall yield of oil is 79%. The treated used oil can be recycled as base lubricating oil. The major disadvantage of this work is the high temperature of solvent recovery. Experimental work and results are presented in detail. PMID:15627468

Hamad, Ahmad; Al-Zubaidy, Essam; Fayed, Muhammad E

2005-01-01

433

"Solvent Effects" in 1H NMR Spectroscopy.  

ERIC Educational Resources Information Center

|Describes a simple undergraduate experiment in chemistry dealing with the "solvent effects" in nuclear magnetic resonance (NMR) spectroscopy. Stresses the importance of having students learn NMR spectroscopy as a tool in analytical chemistry. (TW)|

Cavaleiro, Jose A. S.

1987-01-01

434

Non-aqueous cleaning solvent substitution.  

National Technical Information Service (NTIS)

A variety of environmental, safety, and health concerns exist over use of chlorinated and fluorinated cleaning solvents. Sandia National Laboratories, Lawrence Livermore National Laboratories, and the Kansas City Division of Allied Signal have combined ef...

G. J. Meier

1994-01-01

435

Sampling the proton transfer reaction coordinate in mixed quantum-classical molecular dynamics simulations.  

PubMed

An umbrella sampling approach based on the vibrational energy gap is presented and examined for exploring the reaction coordinate for a proton transfer (PT) reaction. The technique exploits the fact that for a PT reaction the energy gap between the vibrational ground and excited states of the transferring proton reaches a minimum at the transition state. Umbrella sampling is used within mixed quantum-classical simulations to identify the transition state configurations and explore the reaction free energy curve and vibrationally nonadiabatic coupling. The method is illustrated by application to a model phenol-amine proton transfer reaction complex in a nanoconfined solvent. The results from this new umbrella sampling approach are consistent with those obtained from previous umbrella sampling calculations based on a collective solvent coordinate. This sampling approach further provides insight into the vibrationally nonadiabatic coupling for the proton transfer reaction and has potential for simulating vibrational spectra of PT reaction complexes in solution. PMID:22148746

Ka, Being J; Thompson, Ward H

2012-01-10

436

Theory adapters as discipline coordinators  

Microsoft Academic Search

A successful discipline of software engineering will, over time, incorporate within its own borders those theories and techniques from other disciplines which are relevant in and helpful to software development. Since both software engineering and its cognate disciplines will change over time, it must not only incorporate external theories and techniques, but establish active coordination with other disciplines. Having explicit

Andrew Walenstein

2004-01-01

437

Coordinating Social and Academic Goals.  

ERIC Educational Resources Information Center

|The aim of this study was threefold. First, to investigate the strategies adolescents use to coordinate conflicting social and academic goals in situations where these conflicting goals varied in urgency. Second, to examine the importance of social versus academic goals in such situations, and third, to examine the effects of gender and academic…

Lai, Mei Kuin; Townsend, Michael

438

Stereoselective synthesis of coordination compounds  

Microsoft Academic Search

After an introduction, where the general aspects of stereoselective synthesis of coordination species are shortly reviewed, an account of the use of pyridine and bipyridine ligands that are made chiral through incorporation of structural elements taken from terpenes, which occur naturally as enantiopure or at least non-racemic compounds, is given. It is shown that this ligand family, which presently comprises

Alex von Zelewsky

1999-01-01

439

Digital Tide-Coordinated Shoreline  

Microsoft Academic Search

The shoreline is one of the most important features on earth's surface. It is valuable to a diverse user community. But the dynamic nature of the shoreline makes it difficult to be represented in a naturally dynamic style and to be utilized it in applications. The officially used shoreline, for example in nautical charts, is the so-called tide-coordinated shoreline. It

Rongxing Li; Ruijin Ma; Kaichang Di

2002-01-01

440

Improving Channel Coordination Through Franchising  

Microsoft Academic Search

In this paper, we explore the role of franchising arrangements in improving coordination between channel members. In particular we focus on two elements of the franchising contract, namely, the royalty structure and the monitoring technology. We begin with a simple analysis where a manufacturer distributes its product through a retailer and the retail demand is affected by the retail price

Rajiv Lal

1990-01-01

441

Coordinating Investment, Production, and Subcontracting  

Microsoft Academic Search

We value the option of subcontracting to improve financial performance and system coordination by analyzing a competitive stochastic investment game with recourse. The manufacturer and subcontractor decide separately on their capacity investment levels. Then demand uncertainty is resolved and both parties have the option to subcontract when deciding on their production and sales. We analyze and present outsourcing conditions for

Jan A. Van Mieghem

1999-01-01

442

Creating a training coordinator position.  

PubMed

The critical need for high-quality staff training in laboratory animal facilities may lead to the creation of a separate staff position-that of training coordinator. The author offers a series of checklists for use in both defining and then filling such a position. PMID:12040382

Kennedy, Bruce W

2002-06-01

443

COORDINATION IN THE ENGLISH PROGRAM.  

ERIC Educational Resources Information Center

EIGHT SAMPLE LESSON PLANS, PREPARED BY THE TEXAS EDUCATION AGENCY FOR GRADES 7-12, PROVIDE FOUR DIFFERENT PATTERNS FOR COORDINATING THE LANGUAGE ARTS CONCEPTS OF COMPOSITION, LANGUAGE, AND LITERATURE. THE LESSONS INCORPORATE A VARIETY OF TEACHING TECHNIQUES WITH STRESS UPON THE INDUCTIVE APPROACH. THERE ARE TWO LESSON PLANS EACH FOR GRADES 8 AND…

Texas Education Agency, Austin.

444

PEP Ring Coordinates: Configuration E.  

National Technical Information Service (NTIS)

This Engineering Note sets forth the coordinates and the bearing angles for the ring magnets of PEP Configuration E, as set forth on Drawing DJ--2014, RO. The points tabulated are at the entrance and exit of each bend magnet and the middle of each quad ma...

R. Avery T. Chan

1975-01-01

445

Archimedes' Principle in General Coordinates  

ERIC Educational Resources Information Center

|Archimedes' principle is well known to state that a body submerged in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the body. Herein, Archimedes' principle is derived from first principles by using conservation of the stress-energy-momentum tensor in general coordinates. The resulting expression for the force is…

Ridgely, Charles T.

2010-01-01

446

Coordinated Home Care Training Manual.  

ERIC Educational Resources Information Center

This manual is intended as a source of information and assistance in the planning, organization, implementation, and evaluation of home care programs. There are ten major sections: (1) Introduction (review of the history of home care and definition of pertinent terms), (2) Program Planning, (3) Organizational Structure, (4) Coordination and…

Michigan Univ., Ann Arbor. Home Care Training Center.

447

Coordinate confusion in conformal cosmology  

Microsoft Academic Search

A straightforward interpretation of standard Friedmann-Lemaître-Robertson-Walker (FLRW) cosmologies is that objects move apart because of the expansion of space, and that sufficiently distant galaxies must be receding at velocities exceeding the speed of light. Recently, however, it has been suggested that a simple transformation into conformal coordinates can remove superluminal recession velocities, and hence the concept of the expansion of

Geraint F. Lewis; Matthew J. Francis; Luke A. Barnes; J. Berian James

2007-01-01

448

The plane with parallel coordinates  

Microsoft Academic Search

By means ofParallel Coordinates planar “graphs” of multivariate relations are obtained. Certain properties of the relationship correspond tothe geometrical properties of its graph. On the plane a point ?? line duality with several interesting properties is induced. A new duality betweenbounded and unbounded convex sets and hstars (a generalization of hyperbolas) and between Convex Unions and Intersections is found. This

Alfred Inselberg

1985-01-01

449

Co-ordinated Classroom Lectures.  

ERIC Educational Resources Information Center

|From a series of lectures, a selection of eight are oriented principally toward the biologically developing child, and the physiological operations in visual process. The numbered lectures are--(1) The Coordinated Classroom, its Philosophy and Principles, (2) An Outline of a Biological Point of View, (3) The Evolution of Structure--despite man's…

Harmon, Darell Boyd

450

On the Bergman representative coordinates  

NASA Astrophysics Data System (ADS)

We study the set where the so-called Bergman representative coordinates (or Bergman functions) form an immersion. We provide an estimate of the size of a maximal geodesic ball with respect to the Bergman metric, contained in this set. By concrete examples we show that these estimates are the best possible.

Dinew, ?ywomir

2011-07-01

451

BURN DATA COORDINATING CENTER (BDCC)  

EPA Science Inventory

The Burn Data Coordinating Center (BDCC) began collecting data in 1994 and is currently the largest burn database in the country. Pediatric burn data was added in 1998. The BMS database contains over 2,800 cases supporting clinical research and research on outcomes including empl...

452

C[squared] = Creative Coordinates  

ERIC Educational Resources Information Center

|"C[squared] = Creative Coordinates" is an engaging group of tasks that fosters the integration of mathematics and art to create meaningful understanding. The project lets students illustrate of find an image, then plot points to map their design on a grid. The project usually takes about a week to complete. When it is finished, students who are…

McHugh, Shelley R.

2007-01-01

453

On weak dependence conditions for Poisson autoregressions  

Microsoft Academic Search

We consider generalized linear models for regression modeling of count time series. We give easily verifiable conditions for obtaining weak dependence for such models. These results enable the development of maximum likelihood inference under minimal conditions. Some examples which are useful to applications are discussed in detail.

Paul Doukhan; Konstantinos Fokianos

2012-01-01

454

Higgs boson production and weak boson structure.  

National Technical Information Service (NTIS)

The influence of the QCD structure of the weak bosons on the Higgs boson production in e-p scattering is studied. The energy and Higgs boson mass dependence of the cross-section, following from the new contributions, is calculated. (orig.)

W. Slmoinnski J. Szwed

1995-01-01

455

Investigating Acids and Bases: Strong vs Weak  

NSDL National Science Digital Library

This activity is an extension to standard labs that have students generate a pH curve from strong acid/strong base data. Students are asked to predict and test how the the titration end point will shift when titrating vinegar (a weak acid) with NaOH (a strong base).

456

Standard and Non-Standard Weak Interactions.  

National Technical Information Service (NTIS)

This work consists of independent chapters, all deal with weak interactions. The first chapter deals with left-right symmetric theories. Two main versions of these theories are discussed and compared. In addition, the K - K-bar mixing term is analysed: it...

M. Leurer

1985-01-01

457

Molecular Handshake: Recognition through Weak Noncovalent Interactions  

ERIC Educational Resources Information Center

|The weak noncovalent interactions between substances, the handshake in the form of electrostatic interactions, van der Waals' interactions or hydrogen bonding is universal to all living and nonliving matter. They significantly influence the molecular and bulk properties and behavior of matter. Their transient nature affects chemical reactions and…

Murthy, Parvathi S.

2006-01-01

458

Weak Separability in Coffee Demand Systems  

Microsoft Academic Search

Linear versions of the Almost Ideal Demand System are estimated for US and German coffee imports with the intent of testing for homothetic and non-homothetic weak separability and calculating elasticities. Three different separable groupings are tested and separability restrictions are rejected. Elasticities indicate both elastic and inelastic demand for coffee by country of origin, and also that roasters consider such

Daniel Sellen; Ellen Goddard

1997-01-01

459

Weak lensing probes of modified gravity  

SciTech Connect

We study the effect of modifications to general relativity on large-scale weak lensing observables. In particular, we consider three modified gravity scenarios: f(R) gravity, the Dvali-Gabadadze-Porrati model, and tensor-vector-scalar theory. Weak lensing is sensitive to the growth of structure and the relation between matter and gravitational potentials, both of which will in general be affected by modified gravity. Restricting ourselves to linear scales, we compare the predictions for galaxy-shear and shear-shear correlations of each modified gravity cosmology to those of an effective dark energy cosmology with the same expansion history. In this way, the effects of modified gravity on the growth of perturbations are separated from the expansion history. We also propose a test which isolates the matter-potential relation from the growth factor and matter power spectrum. For all three modified gravity models, the predictions for galaxy and shear correlations will be discernible from those of dark energy with very high significance in future weak lensing surveys. Furthermore, each model predicts a measurably distinct scale dependence and redshift evolution of galaxy and shear correlations, which can be traced back to the physical foundations of each model. We show that the signal-to-noise for detecting signatures of modified gravity is much higher for weak lensing observables as compared to the integrated Sachs-Wolfe effect, measured via the galaxy-cosmic microwave background cross-correlation.

Schmidt, Fabian [Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois 60637-1433 (United States) and Kavli Institute for Cosmological Physics, Chicago, Illinois 60637-1433 (United States)

2008-08-15

460

Resource Letter WI-1: Weak Interactions  

ERIC Educational Resources Information Center

|Provides a listing of sources of literature and teaching aids to improve course content in the fields of: weak interactions, beta decay, orbital electron capture, muon capture, semileptonic decay, nonleptonic processes, parity violation in nuclei, neutrino physics, and parity violation in atomic physics. (SL)|

Holstein, Barry R.

1977-01-01

461

Illumination in the Presence of Weak Singularities  

Microsoft Academic Search

Approximating illumination by point light sources, as done in many professional applications, allows for efficient algorithms, but suffers from the problem of the weak singularity: Besides avoiding numerical exceptions caused by the division by the squared distance between the point light source and the point to be illuminated, the estimator should be unbiased and of finite variance. We first illustrate

Thomas Kollig; Alexander Keller

462

PROOF TREES FOR WEAK ACHIEVEMENT GAMES  

Microsoft Academic Search

Proof number search and threat-space search are successful techniques for finding winning strategies in achievement games such as go-moku. A version of proof number search can be used e! ectively to analyze weak achievement games. In this version it is su\\

Nándor Sieben

2008-01-01

463

Weakly localized two-dimensional drift modes  

NASA Astrophysics Data System (ADS)

The structure of drift modes in tokamaks is investigated taking into account modes that are weakly ballooning on the magnetic surfaces. The toroidal mode theory of Conner, Hastie, and Taylor is used to find the surface eigenfunctions and shear damping as a function of the system parameters.

Choi, D.-I.; Horton, W.

1980-02-01

464

The Scott Topology Induces the Weak Topology  

Microsoft Academic Search

Given a probability measure on a compact metric space, we construct an increasing chain of valuations on the upper space of the metric space whose least upper bound is the measure. We then obtain the expected value of any Holder continuous function with respect to the measure up to any precision. We prove that the Scott topology induces the weak

Abbas Edalat

1996-01-01

465

Weak Nonlinearity of Ablative Rayleigh Taylor Instability  

Microsoft Academic Search

The weakly nonlinear regime of single mode ablative Rayleigh-Taylor instability is studied, with consideration of preheat effect and the width of the ablation front. The Rayleigh-Taylor linear growth rate agrees well with the direct numerical simulation. For the density perturbation, the amplitude distribution of the fundamental mode has one peak value whereas those of the second and third harmonics have

Zheng-Feng Fan; Ji-Sheng Luo

2008-01-01

466

Weakly compressible SPH for free surface flows  

Microsoft Academic Search

We present a weakly compressible form of the Smoothed Particle Hydrody namics method (SPH) for fluid flow based on the Tait equation. In contrast to commonly employed projection approa ches that strictly enforce incompress- ibility, time-consuming solvers for the Poisson equation are avoided by allowin g for small, user-defined density fluctuations. We also discuss an improved surface tension model that

Markus Becker; Matthias Teschner

2007-01-01

467

Cultural Capital: Strengths, Weaknesses and Two Advancements  

ERIC Educational Resources Information Center

|In this paper I discuss two weaknesses in Bourdieu's work on cultural capital, both of which are related to his integration of the multidimensional nature of social space in different domains of life: social mobility, lifestyle differentiation, and political orientation. First, there is an anomaly between the work on social mobility and on…

van de Werfhorst, Herman G.

2010-01-01

468

Interaction barriers for light, weakly bound projectiles  

SciTech Connect

A parametrization of the interaction-barrier model of C. Y. Wong [Phys. Rev. Lett. 31, 766 (1973)] is given for light, weakly bound projectiles and also for the exotic 'halo' nuclei {sup 6}He and {sup 8}B. Comparisons are made with the original parametrization. The extremely anomalous behavior of the interaction radius and barrier curvature for halo nuclei is discussed.

Kolata, J. J.; Aguilera, E. F. [Physics Department, University of Notre Dame, Notre Dame, Indiana 46556-5670 (United States); Departamento de Aceleradores, Instituto Nacional de Investigaciones Nucleares, Apartado postal 18-1027, C. P. 11801, Mexico, D. F. (Mexico)

2009-02-15

469

The Strength of Weak Terrorist Ties  

Microsoft Academic Search

The current age of technology, mass communication, and globalization makes networks analysis an especially useful tool for understanding cell-based terrorism. Some concepts from traditional networks analysis may be especially relevant. The Strength of Weak Ties hypothesis (SWT) is particularly promising and will be used here to demonstrate the usability of traditional networks analysis for studying modern terrorism. The findings suggest

Jonathan Kennedy; Gabriel Weimann

2011-01-01

470

Antimatter gravity and the weak equivalence principle  

NASA Astrophysics Data System (ADS)

Ideas are presented for an experiment to compare the acceleration, g, of antiprotons in the Earth's gravitational field with that of particles of normed matter, such as protons or hydrogen ions. The experiments will test whether antiprotons obey the weak equivalence principle.(AIP)

Holzscheiter, M. H.; Brown, R. E.; Camp, J.; Darling, T.; Dyer, P.; Holtkamp, D. B.; Jarmie, N.; King, N. S. P.; Schauer, M. M.; Cornford, S.; Hosea, K.; Kenefick, R. A.; Midzor, M.; Oakley, D.; Ristinen, R.; Witteborn, F. C.

1991-08-01

471

Weakly supervised landmark labeling in searched data  

Microsoft Academic Search

Millions of place-specified photos are uploaded on the internet. Modeling and representing the landmark is very important for landmark retrieval and auto-annotation. In this paper, we aim at collecting images with a specific landmark and labeling the landmark in the images. We propose a weakly supervised labeling approach based on both textual and visual features. Firstly, we cluster the raw

Yanyun Qu; Cheng Chen; Yanyun Cheng; Zejian Yuan

2010-01-01

472

On a Symmetry in Weak Interactions  

Microsoft Academic Search

A symmetry principle is postulated and investigated. All weak ; interactions are invariant under the following simultaneous transformation: A ; yields mu , n yields e, p yields nu . It is found that this ; transformation does not contradict any of the known facts and leads to ; predictions which can be tested. (T.R.H.);

A. Gamba; R. E. Marshak; S. Okubo

1959-01-01

473

Method of stripping metals from organic solvents  

DOEpatents

A new method to strip metals from organic solvents in a manner that allows for the recycle of the stripping agent. The method utilizes carbonate solutions of organic amines with complexants, in low concentrations, to strip metals from organic solvents. The method allows for the distillation and reuse of organic amines. The concentrated metal/complexant fraction from distillation is more amenable to immobilization than solutions resulting from current practice.

Todd, Terry A. (Aberdeen, ID); Law, Jack D. (Pocatello, ID); Herbst, R. Scott (Idaho Falls, ID); Romanovskiy, Valeriy N. (St. Petersburg, RU); Smirnov, Igor V. (St.-Petersburg, RU); Babain, Vasily A. (St-Petersburg, RU); Esimantovski, Vyatcheslav M. (St-Petersburg, RU)

2009-02-24

474

Hydrogen recovery by novel solvent systems  

SciTech Connect

The objective of this work is to develop a novel method for purification of hydrogen from coal-derived synthesis gas. The study involved a search for suitable mixtures of solvents for their ability to separate hydrogen from the coal derived gas stream in significant concentration near their critical point of miscibility. The properties of solvent pairs identified were investigated in more detail to provide data necessary for economic evaluation and process development.

Shinnar, R.; Ludmer, Z.; Ullmann, A.

1991-08-01

475

Localized scleroderma after exposure to organic solvents.  

PubMed

A 26-year-old female developed plaques characteristic of morphea on the volar surfaces of the forearms and on the dorsal surfaces on the ankles following an exposure to trichloroethylene, tetrachloroethylene and other solvents by inhalation. Exposure to chemicals has been known to be important as a provoking factor of systemic sclerosis. This patient shows that exposure to solvents could provoke localized scleroderma. PMID:7873829

Czirják, L; Pócs, E; Szegedi, G

1994-01-01

476

PREPARATION OF I-131 BY SOLVENT EXTRACTION  

Microsoft Academic Search

Craig-type discontinuous countercurrent solvent extraction apparatus was ; used for the separation of I¹³¹ from irradiated telluric acid. Six stages ; were considered enough for more than 85% recovery of radiochemically pure I\\/sup ; 131\\/. The organic solvent phase (TBP-CClâ) could be used repeatedly as a ; fixed phase without removal from the cell. A millicurie of I¹³¹ was ;

Rhee

1963-01-01

477

Scleroderma and Solvent Exposure among Women  

Microsoft Academic Search

Exposure to solvents has been reported to increase the risk of scleroderma. The authors investigated the relation between exposures to solvents in occupational and hobby settings and the development of scleroderma among women in a case-control study with population-based controls in Michigan (1980-1991) and Ohio (1980- 1992). A total of 660 cases and 2,227 frequency-matched controls were interviewed by telephone.

David H. Garabrant; James V. Lacey; Timothy J. Laing; Brenda W. Gillespie; Maureen D. Mayes; Brenda C. Cooper; David Schottenfeld

2003-01-01

478

Biofiltration of solvent vapors from air  

SciTech Connect

For various industrial solvent vapors, biofiltration promises to offer a cost-effective emission control technology. Exploiting the full potential of this technology will help attain the goals of the Clean Air Act Amendments of 1990. Concentrating on large volumes of volatile industrial solvents, stable multicomponent microbial enrichments capable of growing a mineral medium with solvent vapors as their only source of carbon and energy were obtained from soil and sewage sludge. These consortia were immobilized on an optimized porous solid support (ground peat moss and perlite). The biofilter material was packed in glass columns connected to an array of pumps and flow meters that allowed the independent variation of superficial velocity and solvent vapor concentrations. In various experiments, single solvents, such as methanol, butanol, acetonitrile, hexane and nitrobenzene, and solvent mixtures, such as benzene-toluene-xylene (BTX) and chlorobenzene-o-dichlorobenzene (CB/DCB) were biofiltered with rates ranging from 15 to334 g solvent removed per m[sup 3] filter volume /h. Pressure drops were low to moderate (0-10 mmHg/m) and with periodic replacement of moisture, the biofiltration activity could be maintained for a period of several months. The experimental data on methanol biofiltration were subjected to mathematical analysis and modeling by the group of Dr. Baltzis at NJIT for a better understanding and a possible scale up of solvent vapor biofilters. In the case of chlorobenzenes and nitrobenzene, the biofilter columns had to be operated with water recirculation in a trickling filter mode. To prevent inactivation of the trickling filter by acidity during CB/DCB removal, pH control was necessary, and the removal rate of CB/DCB was strongly influenced by the flow rate of the recyling water. Nitrobenzene removal in a trickling filter did not require pH control, since the nitro group was reduced and volatilized as ammonia.

Oh, Young-sook.

1993-01-01

479

Critical solvent deashing of liquefied coal  

Microsoft Academic Search

Critical solvent deashing of liquefied coal by the Kerr-McGee Corporation process reduced the ash content of solidified vacuum still bottoms from the solvent refined coal (SRC) pilot plants at Wilsonville, AL, and Fort Lewis, WA, to less than 0.1% during steady-state operations (for six months starting in June 1977) of a 2.5 ton\\/day skid-mounted pilot plant located in Winnewood, OK.

A. H. Knebel; D. E. Rhodes

1978-01-01

480

Process for solvent refining of coal using a denitrogenated and dephenolated solvent  

DOEpatents

A process is disclosed for the solvent refining of non-anthracitic coal at elevated temperatures and pressure in a hydrogen atmosphere using a hydrocarbon solvent which before being recycled in the solvent refining process is subjected to chemical treatment to extract substantially all nitrogenous and phenolic constituents from the solvent so as to improve the conversion of coal and the production of oil in the solvent refining process. The solvent refining process can be either thermal or catalytic. The extraction of nitrogenous compounds can be performed by acid contact such as hydrogen chloride or fluoride treatment, while phenolic extraction can be performed by caustic contact or contact with a mixture of silica and alumina.

Garg, Diwakar (Macungie, PA); Givens, Edwin N. (Bethlehem, PA); Schweighardt, Frank K. (Allentown, PA)

1984-01-01

481

Solvent dependent photophysical properties of dimethoxy curcumin.  

PubMed

Dimethoxy curcumin (DMC) is a methylated derivative of curcumin. In order to know the effect of ring substitution on photophysical properties of curcumin, steady state absorption and fluorescence spectra of DMC were recorded in organic solvents with different polarity and compared with those of curcumin. The absorption and fluorescence spectra of DMC, like curcumin, are strongly dependent on solvent polarity and the maxima of DMC showed red shift with increase in solvent polarity function (?f), but the above effect is prominently observed in case of fluorescence maxima. From the dependence of Stokes' shift on solvent polarity function the difference between the excited state and ground state dipole moment was estimated as 4.9 D. Fluorescence quantum yield (?(f)) and fluorescence lifetime (?(f)) of DMC were also measured in different solvents at room temperature. The results indicated that with increasing solvent polarity, ?(f) increased linearly, which has been accounted for the decrease in non-radiative rate by intersystem crossing (ISC) processes. PMID:23314392

Barik, Atanu; Indira Priyadarsini, K

2012-12-20

482

Molecular accessibility in solvent swelled coal  

SciTech Connect

Research continued on the determination of pore size and number distribution changes after swelling the coal samples with various solvents. A paper has just been submitted to the journal Fuel on the Low temperature Swelling of Argonne Premium Coal samples using solvents of varying polarity. The variation in the shape of the pore was followed as a function of temperature and swelling solvent polarity. This change in pore structure was attributed to break-up of the hydrogen bonding network in coal by polar solvents. The modification in pore shape from spherical to cylindrical was attributed to anisotropy in hydrogen bond densities. A copy of this paper has been attached to this report. Wojciech Sady has determine the structural changes in the pores that occur when APCS coal is dehydrated prior to swelling with polar solvents. These changes are different from those that occur in the absence of prior dehydration. He has also completed a study on the variation in the hydrogen bonding character of the pore wall as the coals are swelled with various polar solvents. A statistical analysis of the data is currently underway to determine important trends in his data. 9 refs.

Kispert, L.D.

1991-08-01

483

On-line preparation of peroxymonocarbonate and its application for the study of energy transfer chemiluminescence to lanthanide inorganic coordinate complexes.  

PubMed

It has been shown that peroxymonocarbonate ion (HCO(4) (-)) is a potent oxidant. In this study, a flow-injection system was developed in order to prepare on-line HCO(4) (-) ion and the optimum conditions for the on-line preparation of HCO(4) (-) were studied in detail. We used 99% (13)C-enriched NaHCO(3) to examine peroxymonocarbonate by (13)C-NMR at 25 degrees C. An ultra-weak chemiluminescence (CL) was observed after mixing H(2)O(2) and sodium bicarbonate in an organic co-solvent that can accelerate the formation of HCO(4) (-) ion. When lanthanide inorganic coordinate complex, Eu(II)-EDTA, was added into this HCO(4) (-) system, the CL intensity was significantly enhanced. The CL mechanism was investigated by various methods. The experimental results indicate that peroxymonocarbonate oxidizes Eu(II) to Eu(III) and produces singlet oxygen; meanwhile, the energy originating from dimers of singlet oxygen is accepted by the Eu(III)-EDTA(-) complex. The excited Eu(III) ions undergo radiative deactivation and emit CL. PMID:16645954

Liu, Meilin; Cheng, Xianglei; Zhao, Lixia; L