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1

Weakly charged polyelectrolytes in a poor solvent J. F. Joanny (1) and L. Leibler (2)  

E-print Network

augmentée. Abstract. 2014 We show that a weakly charged polyelectrolyte in a salt free poor solvent545 Weakly charged polyelectrolytes in a poor solvent J. F. Joanny (1) and L. Leibler (2) (1 separation between polymer and solvent. The multicritical point of these two transitions is a so

Paris-Sud XI, Université de

2

Solvent extraction: the coordination chemistry behind extractive metallurgy.  

PubMed

The modes of action of the commercial solvent extractants used in extractive hydrometallurgy are classified according to whether the recovery process involves the transport of metal cations, M(n+), metalate anions, MXx(n-), or metal salts, MXx into a water-immiscible solvent. Well-established principles of coordination chemistry provide an explanation for the remarkable strengths and selectivities shown by most of these extractants. Reagents which achieve high selectivity when transporting metal cations or metal salts into a water-immiscible solvent usually operate in the inner coordination sphere of the metal and provide donor atom types or dispositions which favour the formation of particularly stable neutral complexes that have high solubility in the hydrocarbons commonly used in recovery processes. In the extraction of metalates, the structures of the neutral assemblies formed in the water-immiscible phase are usually not well defined and the cationic reagents can be assumed to operate in the outer coordination spheres. The formation of secondary bonds in the outer sphere using, for example, electrostatic or H-bonding interactions are favoured by the low polarity of the water-immiscible solvents. PMID:24088789

Wilson, A Matthew; Bailey, Phillip J; Tasker, Peter A; Turkington, Jennifer R; Grant, Richard A; Love, Jason B

2014-01-01

3

Novel weak coordination to silylium ions: formation of nearly linear SiHSi bonds{  

E-print Network

Novel weak coordination to silylium ions: formation of nearly linear Si­H­Si bonds{ Stephan P511344j The weakly coordinating carborane anion in ion-like trialk- ylsilyl species R3Si(CHB11Cl11) can (R3Si+ ) in condensed media is an unsolved problem because unsaturation in three- coordinate silicon

Reed, Christopher A.

4

Weak coordination as a powerful means for developing broadly useful C-H functionalization reactions.  

PubMed

Reactions that convert carbon-hydrogen (C-H) bonds into carbon-carbon (C-C) or carbon-heteroatom (C-Y) bonds are attractive tools for organic chemists, potentially expediting the synthesis of target molecules through new disconnections in retrosynthetic analysis. Despite extensive inorganic and organometallic study of the insertion of homogeneous metal species into unactivated C-H bonds, practical applications of this technology in organic chemistry are still rare. Only in the past decade have metal-catalyzed C-H functionalization reactions become more widely utilized in organic synthesis. Research in the area of homogeneous transition metal-catalyzed C-H functionalization can be broadly grouped into two subfields. They reflect different approaches and goals and thus have different challenges and opportunities. One approach involves reactions of completely unfunctionalized aromatic and aliphatic hydrocarbons, which we refer to as "first functionalization". Here the substrates are nonpolar and hydrophobic and thus interact very weakly with polar metal species. To overcome this weak affinity and drive metal-mediated C-H cleavage, chemists often use hydrocarbon substrates in large excess (for example, as solvent). Because highly reactive metal species are needed in first functionalization, controlling the chemoselectivity to avoid overfunctionalization is often difficult. Additionally, because both substrates and products are comparatively low-value chemicals, developing cost-effective catalysts with exceptionally high turnover numbers that are competitive with alternatives (including heterogeneous catalysts) is challenging. Although an exciting field, first functionalization is beyond the scope of this Account. The second subfield of C-H functionalization involves substrates containing one or more pre-existing functional groups, termed "further functionalization". One advantage of this approach is that the existing functional group (or groups) can be used to chelate the metal catalyst and position it for selective C-H cleavage. Precoordination can overcome the paraffin nature of C-H bonds by increasing the effective concentration of the substrate so that it need not be used as solvent. From a synthetic perspective, it is desirable to use a functional group that is an intrinsic part of the substrate so that extra steps for installation and removal of an external directing group can be avoided. In this way, dramatic increases in molecular complexity can be accomplished in a single stroke through stereo- and site-selective introduction of a new functional group. Although reactivity is a major challenge (as with first functionalization), the philosophy in further functionalization differs; the major challenge is developing reactions that work with predictable selectivity in intricately functionalized contexts on commonly occurring structural motifs. In this Account, we focus on an emergent theme within the further functionalization literature: the use of commonly occurring functional groups to direct C-H cleavage through weak coordination. We discuss our motivation for studying Pd-catalyzed C-H functionalization assisted by weakly coordinating functional groups and chronicle our endeavors to bring reactions of this type to fruition. Through this approach, we have developed reactions with a diverse range of substrates and coupling partners, with the broad scope likely stemming from the high reactivity of the cyclopalladated intermediates, which are held together through weak interactions. PMID:22166158

Engle, Keary M; Mei, Tian-Sheng; Wasa, Masayuki; Yu, Jin-Quan

2012-06-19

5

Coordinative Properties of Highly Fluorinated Solvents with Amino and Ether Groups  

PubMed Central

In spite of the widespread use of perfluorinated solvents with amino and ether groups in a variety of application fields, the coordinative properties of these compounds are poorly known. It is generally assumed that the electron withdrawing perfluorinated moieties render these functional groups rather inert, but little is known quantitatively about the extent of their inertness. This paper reports on the interactions between inorganic monocations and perfluorotripentylamine and 2H-perfluoro-5,8,11-trimethyl-3,6,9,12-tetraoxapentadecane, as determined with fluorous liquid-membrane cation-selective electrodes doped with tetrakis[3,5-bis(perfluorohexyl)phenyl]borate salts. The amine does not undergo measurable association with any ion tested, and its formal pKa is shown to be smaller than -0.5. This is consistent with the nearly planar structure of the amine at its nitrogen center, as obtained with density functional theory calculations. The tetraether interacts very weakly with Na+ and Li+. Assuming 1:1 stoichiometry, formal association constants were determined to be 2.3 and 1.5 M-1, respectively. This disproves an earlier proposition that the Lewis base character in such compounds may be non-existent. Due to the extremely low polarity of fluorous solvents and the resulting high extent of ion pair formation, a fluorophilic electrolyte salt with perfluoroalkyl substituents on both the cation and the anion had to be developed for these experiments. In its pure form, this first fluorophilic electrolyte salt is an ionic liquid with a glass transition temperature, Tg, of -18.5 C. Interestingly, the molar conductivity of solutions of this salt increases very steeply in the high concentration range, making it a particularly effective electrolyte salt. PMID:16316244

Boswell, Paul G.; Lugert, Elizabeth C.; Rabai, Jozsef; Amin, Elizabeth A.; Buhlmann, Philippe

2008-01-01

6

Specific solvent effect on lumazine photophysics: A combined fluorescence and intrinsic reaction coordinate analysis  

NASA Astrophysics Data System (ADS)

The photophysical properties and tautomerization behavior of neutral lumazine were studied by fluorescence spectroscopy and density functional theory calculation. A quantitative estimation of the contributions from different solvatochromic parameters, like solvent polarizibility (??), hydrogen bond donation (?) and hydrogen bond accepting (?) ability of the solvent, was made using linear free energy relationships based on the Kamlet-Taft equation. The analysis reveals that the hydrogen bond acceptance ability of the solvent is the most important parameter characterizing the excited state behavior of lumazine. Theoretical calculations result predict an extensive charge redistribution of lumazine upon excitation corresponding to the N3 and N1 proton dissociation sites by solvents in the ground and excited states, respectively. Comparison of S0 and S1 state potential energy curves constructed for several water mediated tautomerization processes by intrinsic reaction coordinate analysis of lumazine-H2O cluster shows that (3,2) and (1,8) hydrogen migrations are the most favorable processes upon excitation.

Moyon, N. Shaemningwar; Gashnga, Pynsakhiat Miki; Phukan, Smritakshi; Mitra, Sivaprasad

2013-06-01

7

Timing and Virtual Observability in Ultimatum Bargaining and "Weak Link" Coordination Games  

E-print Network

Timing and Virtual Observability in Ultimatum Bargaining and "Weak Link" Coordination Games Roberto behavior in games, even when the first-mover's moves are known to be unobservable. This observation violates the game-theoretic principle that timing of unobserved moves is irrelevant, but is consistent

Greer, Julia R.

8

[Cu(I)(bpp)]BF4: the first extended coordination network prepared solvothermally in an ionic liquid solvent  

E-print Network

[Cu(I)(bpp)]BF4: the first extended coordination network prepared solvothermally in an ionic liquid-butyl- 3-methylimidazolium) as solvent has resulted in the first extended coordination structure on noncoordinating dialkylimidazolium cations with poorly coordinating anions, have been studied extensively

Li, Jing

9

Synthesis and Properties of the Weakly Coordinating Anion [Me3 NB12 Cl11 ](-).  

PubMed

The weakly coordinating anion [Me3 NB12 Cl11 ](-) has been prepared by a simple two-step procedure. The anion [Me3 NB12 Cl11 ](-) is easily obtained in batches of up to 20?g by chlorination of the known [H3 NB12 H11 ](-) anion with SbCl5 at about 190?C and subsequent N-methylation with methyl iodide. Starting from Na[Me3 NB12 Cl11 ], several synthetically useful salts with reactive cations ([NO](+) , [Ph3 C](+) , and [(Et3 Si)2 H](+) ) were prepared. Full spectroscopic (NMR, IR, Raman, TGA, MS) characterization and single-crystal X-ray diffraction studies confirmed the identity and purity of the products. The thermal, chemical, and electrochemical stability as well as the basicity of the [Me3 NB12 Cl11 ](-) anion is similar to that of the structurally related weakly coordinating 1-carba-closo-dodecaborate and closo-dodecaborate anions. The facile preparation of the [Me3 NB12 Cl11 ](-) anion and its ideal chemical and physical properties make it a cheap alternative to other classes of weakly coordinating anions. PMID:25196859

Bolli, Christoph; Derendorf, Janis; Jenne, Carsten; Scherer, Harald; Sindlinger, Christian P; Wegener, Bianca

2014-10-13

10

A multi-functional coordination polymer coexisting spontaneous chirality resolution and weak ferromagnetism  

NASA Astrophysics Data System (ADS)

A multifunctional homochiral coordination polymer, [Co(H2O)(BDC)(4,4?-BPY)]3H2O (1) (H2BDC=1,2-benzenedicarboxylate and 4,4?-BPY=4,4?-bipyridine), has been successfully isolated from Co(II) ions and mixed ligands (1,2-benzenedicarboxylate and 4,4?-bipyridine). Complex 1, which exhibits spontaneous chirality resolution and weak ferromagnetism, is built by chiral helices interconnected via end-to-end 4,4?-BPY bridges into a two-dimensional (2D) layer structure.

Li, Xiu-Hua; Zhang, Qi; Hu, Ping

2014-10-01

11

Effects of solvent systems on two silver coordination complexes: From discrete structure to 2D sheet  

NASA Astrophysics Data System (ADS)

Two mixed-ligand silver(I) coordination complexes (CCs), [Ag4(mpyz)(npt)2(H2O)2]n (1) and [Ag4(mpyz) (npt)2]n (2) were synthesized with reactions of methyl-pyrazine(mpyz) and 3-nitro-1,2-benzenedicarboxylic acid (H2npt) with silver nitrate in different solvent systems and were structurally characterized by single-crystal X-ray crystallography. Structural differences of CCs are due to the effects of solvent systems and the intricacy of the self-assembly process for these systems. For 1, the Ag4 unit which is like Y letter which stand upside and down and repeat to form a 1D-63-silver-ring which shares Ag1 and Ag2 only with npt ligands. The eight Ag ions of complex 2 are in a shape like the branches of a tree which repeat to form a 1D silver chain. Effects of solvents on the structures, as well as the intricacy of the self-assembly process were discussed. The photoluminescence, infrared spectroscopy (IR) and thermogravimetric analyses (TGA) behaviors of the compounds were also discussed.

Wang, Dan-Feng; Wang, Zhan-Hui; Lu, Bo-Wei; Chen, Shu-Fen; Zhang, Ting; Huang, Rong-Bin; Zheng, Lan-Sun

2014-02-01

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 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

13

WBC-ALC: A Weak Blocking Coordinated Application-Level Checkpointing for MPI Programs  

NASA Astrophysics Data System (ADS)

As supercomputers increase in size, the mean time between failures (MTBF) of a system becomes shorter, and the reliability problem of supercomputers becomes more and more serious. MPI is currently the de facto standard used to build high-performance applications, and researches on the fault tolerance methods of MPI are always hot topics. However, due to the characteristics of MPI programs, most current checkpointing methods for MPI programs need to modify the MPI library (even operating system), or implement a complicated protocol by logging lots of messages. In this paper, we carry forward the idea of Application-Level Checkpointing (ALC). Based on the general fact that programmers are familiar with the communication characteristics of applications, we have developed BC-ALC, a new portable blocking coordinated ALC for MPI programs. BC-ALC neither modifies the MPI library (even operating system) nor logs any message. It implements coordination only by the Barrier operations instead of any complicated protocol. Furthermore, in order to reduce the cost of fault-tolerance, we reduce the synchronization range of the barrier, and design WBC-ALC, a weak blocking coordinated ALC utilizing group synchronization instead of global synchronization based on the communication relationship between processes. We also propose a fault-tolerance framework developed on top of WBC-ALC and discuss an implementation of it. Experimental results on NPB3.3-MPI benchmarks validate BC-ALC and WBC-ALC, and show that compared with BC-ALC, the average coordination time and the average backup time of a single checkpoint in WBC-ALC are reduced by 44.5% and 5.7% respectively.

Xu, Xinhai; Yang, Xuejun; Lin, Yufei

14

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

E-print Network

dioxide photoexcitation Craig Brooksby, Oleg V. Prezhdo,a) and Philip J. Reid Department of Chemistry The solvation dynamics following photoexcitation of chlorine dioxide OClO in different solvents are investigated chemistry.1­3 Representative of this group of compounds, chlorine dioxide OClO has been the subject of much

15

Use of solvent to regulate the degree of polymerisation in weakly associated supramolecular oligomers.  

PubMed

Using a tetrathiafulvalene functionalised calix[4]pyrrole (TTF-C[4]P; ) and alkyl diester-linked bis-dinitrophenols (), it was found that the solvent polarity and linker length have an effect on the molecular aggregation behaviour. 2D (1)H NOESY, DOSY NMR and UV-vis-NIR spectroscopic studies, as well as single crystal X-ray diffraction analyses support these conclusions. PMID:24722903

Bhring, Steffen; Kim, Dong Sub; Duedal, Troels; Lynch, Vincent M; Nielsen, Kent A; Jeppesen, Jan O; Sessler, Jonathan L

2014-05-28

16

Metal ions and solvents ratio co-regulate four new magnetic coordination polymers based upon an unsymmetric tricarboxylate acid ligand.  

PubMed

Four new coordination polymers (CPs), [Co3(L)2(bib)3(EtOH)2]2H2O (1), [Mn3(L)2(bib)2(H2O)4]4H2O (2), [Ni(HL)(bib)(H2O)3] (3) and [Ni3(bib)4(H2O)10]2(L)12(H2O) (4), were synthesized under solvothermal conditions with an unsymmetrical tricarboxylic acid ligand [biphenyl-3,3',5-tricarboxylic acid (H3L)] in the presence of the 1,4-bis(1H-imidazol-4-yl)benzene (bib) ligand. In compound 1, tricarboxylate acid ligands (H3L) link Co centers to generate two-dimensional (2D) layers which are further connected by bib ligands to exhibit a three-dimensional (3D) framework with a (4,4,5)-connected (4(2)6(3)8)2(4(2)6(7)8)2(6(4)810) topology. The three-dimensional (3D) framework of 2 is defined as a (3,3,4)-connected topology with the point symbol of (68(2))2(6(2)8)2(810(4)12). Compound 3 contains a one-dimensional (1D) left-hand helix chain along the a direction and further extends into a 2D supramolecular network and a 3D supramolecular framework via hydrogen bonds. Compound 4 displays a one-dimensional (1D) molecular ladder, which is further combined with each other through ?? stacking to extend into 2D supramolecular sheets. The supramolecular networks of 3 and 4 resulted from the different solvent ratios [V(H2O)-V(EtOH)] in the reaction. All the CPs are characterized by single-crystal X-ray diffraction analyses, powder X-ray diffraction (PXRD), elemental analyses, IR spectroscopy, and TGA analyses. Moreover, the weak ferromagnetic properties of 2 and 3 and antiferromagnetic properties of 1 and 4 have also been investigated. PMID:24905184

Li, Yuan-Pu; Chai, Ying; Yang, Guo-Ping; Miao, Hui-Hui; Cui, Lin; Wang, Yao-Yu; Shi, Qi-Zhen

2014-07-28

17

Identical extraction behavior and coordination of trivalent or hexavalent f-element cations using ionic liquid and molecular solvents.  

PubMed

The extraction of both UO2(2+) and trivalent lanthanide and actinide ions (Am3+, Nd3+, Eu3+) by dialkylphosphoric or dialkylphosphinic acids from aqueous solutions into the ionic liquid, 1-decyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide has been studied and compared to extractions into dodecane. Radiotracer partitioning measurements show comparable patterns of distribution ratios for both the ionic liquid/aqueous and dodecane/aqueous systems, and the limiting slopes at low acidity indicate the partitioning of neutral complexes in both solvent systems. The metal ion coordination environment, elucidated from EXAFS and UV-visible spectroscopy measurements, is equivalent in the ionic liquid and dodecane solutions with coordination of the uranyl cation by two hydrogen-bonded extractant dimers, and of the trivalent cations by three extractant dimers. This is the first definitive report of a system where both the biphasic extraction equilibria and metal coordination environment are the same in an ionic liquid and a molecular organic solvent. PMID:15909044

Cocalia, Violina A; Jensen, Mark P; Holbrey, John D; Spear, Scott K; Stepinski, Dominique C; Rogers, Robin D

2005-06-01

18

Influence of weak electric fields on Rydberg electron wavepacket dynamics in the radial coordinate  

Microsoft Academic Search

The spinorbit autoionisation dynamics of Rydberg electron wavepackets in Ar are investigated in weak electric fields, where ???13.8 and ? is the scaled energy in atomic units. The electric field modifies both the interference pattern and revival time of the recurrence spectrum. By writing the energies of the eigenstates included in the superposition as a Taylor's expansion, a quantitative description

V. G. Stavros; H. H. Fielding

1998-01-01

19

Continuum Hartree-Fock-Bogoliubov theory for weakly bound deformed nuclei using coordinate-space Green's function method  

E-print Network

We formulate a new scheme of the Hartree-Fock-Bogoliubov mean-field theory applicable to weakly bound and pair correlated deformed nuclei using the coordinate-space Green's function technique. On the basis of a coupled-channel representation of the quasiparticle wave function expanded in terms of the partial waves, we impose the correct boundary condition of the asymptotically out-going waves on the continuum quasiparticle states. We perform numerical analysis for $^{38}$Mg to illustrate properties of the continuum quasiparticle states and the pair correlation in deformed nuclei near the neutron drip-line.

Hiroshi Oba; Masayuki Matsuo

2009-05-20

20

Weak cooperativity in selected iron(II) 1D coordination polymers  

NASA Astrophysics Data System (ADS)

The spin crossover behaviour of a new class of FeII coordination polymers [Fe(phtptrz)3]I2 ( 1), [Fe(phtptrz)3](ReO4)2CH3OH ( 2) and [Fe(phtptrz)3]TaF76H2O ( 3) based on a novel ligand 4-(3' -N-phtalimido-propyl)-1,2,4-triazole (phtptrz), were investigated by temperature dependent 57Fe Mssbauer spectroscopy and magnetic susceptibility measurements. The adverse effect of bulky substituent on 1,2,4-triazole, favorable supramolecular interactions and influence of increasing anion size on spin crossover profile is discussed. 1 and 2 show thermally induced spin conversions of gradual and incomplete nature with associated thermochromism, and transition temperatures T1/2 ~ 163 K and 137 K, respectively. A spin state crossover is also identified for 3.

Drtu, Marinela M.; Gillard, Damien; Naik, Anil D.; Rotaru, Aurelian; Garcia, Yann

2012-03-01

21

High pressure nuclear magnetic resonance study of the dynamical solvent effects on the rotation of coordinated ethylene in an organometallic compound  

Microsoft Academic Search

The effect of temperature and pressure on the internal rotation rate of coordinated ethylene in ?cyclopentadienylethylenetetrafluoroethylenerhodium in liquid solution has been investigated by using 1H Fourier transform (FT) nuclear magnetic resonance spectroscopy. The solvents used in this study are npentaned12, carbon disulfide, and methylcyclohexaned14. The activation energy (13.40.2 kcal\\/mol) for the internal rotation of ethylene is independent of solvent and

Xiangdong Peng; Jiri Jonas

1990-01-01

22

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

23

Coordinates  

NSDL National Science Digital Library

This introduction to the labeling of points on a plane by their Cartesian coordinates can optionally be extended to coordinates in 3-dimensional space, to plane polar coordinates and to 3-dimensional polar coordinates. Students should learn to use Cartesian coordinates (x,y) for defining the position of a point in two dimensions and to use Cartesian coordinates (x,y,z) in 3-dimensional space and learn to appreciate the two ways of defining the z axis. Students should also become familiar with some of the tools and terms used by surveyors such as theodolite, azimuth, elevation, and zenith. Optional items for students familiar with trigonometry and with the theorem of Pythagoras are polar coordinates (r,f ) on the plane, Converting (r,f) to (x,y) and vice versa, at least for r, and Spherical polar coordinates (r,q, f) in 3-dimensional space.

Stern, David

24

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

Microsoft Academic Search

Three magnesium based metal-organic frameworks, Mg(3,5-PDC)(DMF) · DMF [1], Mg(3,5-PDC)(HO) · (HO) [3], and Mg(3,5-PDC)(DMF)(HO) · 2DMF · 4.5HO [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(HO)] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2\\/n, a = 12.3475(5) , b = 11.1929(5) , c = 28.6734(12) , β =

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

2011-01-01

25

The investigation of the solvent effect on coordination of nicotinato ligand with cobalt(II) complex containing tris(2-benzimidazolylmethyl)amine: A computational study  

NASA Astrophysics Data System (ADS)

The electronic structure of [Co(ntb)(nic)]+ complex ion are optimized by using density functional theory (DFT) method with mix basis set. Where (ntb) represents tris(2-benzimidazolylmethyl)amine ligand and (nic) is the anion of nicotinic acids. Six different fields, vacuum, chloroform, butanonitrile, methanol, water and formamide solvents are used in these calculations. The calculated structural parameters indicate that (nic) ligand coordinates to cobalt(II) containing (ntb) ligand with one oxygen atom in butanonitrile, methanol, water and formamide solvents but coordinates with two oxygen atoms in vacuum. These results are supported with IR, UV and 1H NMR spectra. According to the calculated results, the geometry of [Co(ntb)(nic)]+ complex ion is distorted octahedral in vacuum while the geometry is distorted square pyramidal in the all other solvents. Distorted octahedral [Co(ntb)(nic)]+ complex ion have not been synthesized as experimentally and it is predicted with computational chemistry methods.

Sayin, Koray; Karaka?, Duran

2014-11-01

26

Theoretical study of the effect of coordinating solvent on ion pair SN2 reactions: the role of unsymmetrical transition structures.  

PubMed

Computations are reported at the HF/6-31+g* level for ion pair SN2 reactions of methyl, ethyl, n-propyl, isopropyl, and allyl halides with LiX.E, LiX.2E, and LiX.3E (X = F, Cl, Br; E = dimethyl ether as a model for THF). Some calculations were also done at the MP2, B3LYP, and mPW1PW91 levels. In addition to normal SN2-type (type I) transition structures (TSs), novel unsymmetrical TSs were found in which the Li is coordinated to a single halide. With LiX.2E, such structures are already competitive with the type I structures, and with LiX.3E, only the type II structures were found. With incorporation of dielectric solvation, the type II structures are relatively even more stable. The results suggest that such structures are better models for ion pair displacement reactions in ethereal solvents. PMID:17266378

Streitwieser, Andrew; Jayasree, Elambalassery G

2007-03-01

27

Effect of ester side chains and solvent polarity on the electronic spectra and coordination chemistry of aquacyanocobyrinic acid heptamethylester  

Microsoft Academic Search

Aquacyanocobyrinic acid heptamethyl ester (Aquacyanocobester) has been prepared from vitamin B12 after converting the seven amide side chains into methyl esters. The solvent dependence of the absorption spectrum of aquacyanocobester has shown that the wavelengths of the ?-band varied from 362.5 nm in non-polar solvent (CCl4) through 359.5 nm in a more polar solvent (CH3CN) to 353 nm in protic

M. S. A Hamza

1998-01-01

28

Coordinated study of non-seismic and weak seismic events (magnitude M less than 5) using VLF radio links  

NASA Astrophysics Data System (ADS)

In this study we analyze low seismicity earthquakes (EQs) with magnitudes M < 5 in South Eastern Europe, time period 2011-2013, via very low frequency (VLF) radio links. The main scientific objective of the statistical and event based investigations are reliable characterization of typical seismic and non-seismic variations in the VLF signal. The focus is on robust results, especially for weak EQs, because non-seismic influences could have a strong effect on the analysis. Various electromagnetic methods have been developed in order to study possible earthquake precursor phenomena generated in the lithosphere and then propagating in the atmosphere / ionosphere [1]. The major challenge of this seismo-electromagnetic (SEM) method is to differentiate parameter variations and disentangle seismic from non-seismic sources. In the course of the European radio receiver network (International Network for Frontier Research on Earthquake Precursors, INFREP) radio signals in the VLF/LF frequency range are continuously recorded by dedicated, distributed transmitters. The major VLF receiving station for this study (10-50 kHz, Graz, Austria) operates continuously throughout the year, the selected network-wide temporal resolution is 20 sec, 12 transmitters, located mainly in Europe, are received (amplitude and phase). The facility has a proven high reliability and availability. The VLF links from the transmitters to the receivers are sometimes more, sometimes less influenced by various disturbances. In case the signal is crossing an EQ preparation zone, we are in principle able to detect seismic activity if the signal to noise ratio is high enough [2]. Generally we distinguish between ionospheric or atmospheric disturbances, influences which depend on the EQ properties, and transmitter variations itself. Ionospheric / Atmospheric variations can be generated, e.g. by geomagnetic storms, solar flares or waves in the troposphere. The properties of the sub-ionospheric VLF waveguide are affected by the length of the radio path, the distance to the EQ preparation zone, the parameters of the earthquake (magnitude, depth, type), and daytime / nighttime disturbances. In order to minimize ionospheric influences on the radio path we are considering mainly nighttime periods. Beside the terminator time method, where only the VLF sunrise and sunset period is analyzed, we are using the residual method (2 hours before and after local midnight), where the difference between the monthly mean amplitude and the nighttime variation is calculated. Anomalous signal variations outside the two sigma borderline are used to determine possible seismo-electromagnetic events. We conclude that the coordinated study of seismic and non-seismic signals in VLF links is an essential part in SEM investigations, but - as an outlook - shall be supplemented with complementary methods that explore a wider frequency range. References: [1] O. Molchanov, M. Hayakawa: Seismo-Electromagnetics and related Phenomena: History and latest results, Terrapub, 2008. [2] A. Rozhnoi et al.: Anomalies in VLF radio signals prior Abruzzo earthquake (M=6.3) on 6 April 2009, National Hazards and Earth System Sciences, 9, 1727-1732, 2009.

Wolbang, Daniel; Biernat, Helfried K.; Friedrich, Martin; Schwingenschuh, Konrad; Besser, B. P.; Eichelberger, Hans; Prattes, Gustav; Rozhnoi, Alexander; Solovieva, Maria; Biagi, Pier Francesco; Boudjada, Mohammed Y.

29

Solvent-templated supramolecular isomerism in 2D coordination polymer constructed by Ni(II)2Co(II) nodes and dicyanamido spacers: drastic change in magnetic behaviours.  

PubMed

Two heterometallic coordination polymers (CPs) have been prepared using [Ni(II)L]2Co(II) (where H2L = N,N'-bis(salicylidene)-1,3-propanediamine) as nodes and dicyanamido spacers by varying the solvent for synthesis. Structural characterizations revealed that methanol assisted the formation of a two-dimensional (4,4) connected rhombic grid network of [(NiL)2Co(NCNCN)2]? (1a) whereas relatively less polar acetonitrile afforded a different superstructure {[(NiL)2Co(NCNCN)2]CH3CN}? (1b) with a two-dimensional (4,4) connected square grid network. The presence of acetonitrile molecules in the structure of 1b seems to change the spatial orientation of the terminal metalloligands [NiL] from pseudo-eclipsed in 1a to staggered-like in 1b around the central Co(II). These structural changes in the nodes together with the conformationally flexible dicyanamido spacers, which are cis coordinated to the Co(II) in both trinuclear units, led to the differences in the final 2D network. Variable-temperature magnetic susceptibility measurements revealed that this supramolecular isomerism led to a drastic transition from spin-frustrated antiferromagnetism for 1a to a dominant ferromagnetic behaviour for 1b. The geometrical differences in Ni2Co coordination clusters (CCs) which are scalene triangular in 1a but nearly linear in 1b, are held responsible for the changes of the magnetic properties. The DFT calculations of exchange interactions between metal centres provide a clear evidence of the role played by the fundamental geometrical factors on the nature and magnitude of the magnetic coupling in these pseudo-polymorphic CPs. PMID:23900267

Ghosh, Soumavo; Mukherjee, Sandip; Seth, Piya; Mukherjee, Partha Sarathi; Ghosh, Ashutosh

2013-10-01

30

Polar, non-coordinating ionic liquids as solvents for the alternating copolymerization of styrene and CO catalyzed by cationic palladium catalysts.  

PubMed

The palladium-catalyzed copolymerization of styrene and CO in an ionic liquid solvent, 1-hexylpyridinium bis(trifluoromethanesulfonyl)imide, gave improved yields and increased molecular weights compared to polymerizations run in methanol. PMID:12125572

Klingshirn, Marc A; Broker, Grant A; Holbrey, John D; Shaughnessy, Kevin H; Rogers, Robin D

2002-07-01

31

Solvent-free synthesis of metal complexes  

Microsoft Academic Search

Avoiding the use of solvents in synthesis can reduce environmental contamination and even be more convenient than using solvent-based synthesis. In this tutorial review we focus on recent research into the use of mechanochemistry (grinding) to synthesise metal complexes in the absence of solvent. We include synthesis of mononuclear complexes, coordination clusters, spacious coordination cages, and 1-, 2- and 3-dimensional

Ana Lazuen Garay; Anne Pichon; Stuart L. James

2007-01-01

32

Catalyst design for iron-promoted reductions: an iron disilyl-dicarbonyl complex bearing weakly coordinating ?2-(H-Si) moieties.  

PubMed

Iron disilyl dicarbonyl complex 1, in which two H-Si moieties of the 1,2-bis(dimethylsilyl)benzene ligand were coordinated to the iron center in an ?(2)-(H-Si) fashion, was synthesized by the reaction of (?(4)-C6H8)Fe(CO)3 with 2 equiv. of 1,2-bis(dimethylsilyl)benzene under photo-irradiation. Complex 1 demonstrated high catalytic activity toward the hydrogenation of alkenes, the hydrosilylation of alkenes and the reduction of carbonyl compounds. PMID:24154529

Sunada, Yusuke; Tsutsumi, Hironori; Shigeta, Keisuke; Yoshida, Ryota; Hashimoto, Toru; Nagashima, Hideo

2013-12-28

33

Can weak interactions modify the binding properties of a strong nitrogen donor? Unusual N-coordination of a phosphoranylidene-substituted pyrazolone unit towards palladium(II) centres: an experimental and theoretical study.  

PubMed

Selective N(2)-binding of 3-methyl-1-phenyl-4-(triphenylphosphoranylidene)-2-pyrazolin-5-one (L) has been found in two palladium(II) complexes, [PdCl(2)L(2)](2) and [Pd(o-C(6)H(4)CH(2)NMe(2))Cl](3). X-Ray diffraction studies show that the pyrazole rings lie almost perpendicular to the coordination plane. In both complexes the metal atom is located out of the plane defined by the pyrazole ring(s)(dihedral angle between the plane and the Pd-N vector approximately 30 degrees). To investigate the origin of this distortion, a theoretical study was carried out on a simplified model of complex , where a single pyrazolone ligand was replaced by NH(3). From this study it could be inferred that the out-of-plane distortion mainly involves weak, electrostatic interactions between a chlorine atom and an ortho-aromatic H atom of the N(1)-linked phenyl group, as well as between the other chlorine atom and an ortho-aromatic H atom of the PPh(3) group. PMID:16172639

Mota, Antonio J; Dedieu, Alain; Kuhn, Pierre; Matt, Dominique; Welter, Richard; Neuburger, Markus

2005-10-01

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

Weak deeply virtual Compton scattering  

NASA Astrophysics Data System (ADS)

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.; Melnitchouk, W.; Radyushkin, A. V.

2007-03-01

36

MOFs by solvent free high temperature synthesis exemplified by ? 3[Eu 3(Tz ?) 6(Tz ?H) 2  

Microsoft Academic Search

Solvent free synthesis methods of solid state chemistry can be utilized to synthesize MOFs (metal organic frameworks) and moreover render frameworks accessible that cannot be obtained from classic solvent reactions. Focusing on nitrogen coordinated rare earth compounds amides and nitriles can be successfully obtained from melts of the referring neutral N donor ligands. Exclusion of solvents prevents solvent co-coordination so

Klaus Mller-Buschbaum; Yassin Mokaddem

2008-01-01

37

Solvent-ligated copper(II) complexes for the homopolymerization of 2-methylpropene.  

PubMed

Copper(II) complexes with weakly coordinating counter anions can be utilized as highly efficient catalysts for the synthesis of poly(2-methylpropene) ("polyisobutene") with a high content of terminal double bonds. These copper(II) compounds are significantly more active than the manganese(II) complexes described previously, can be applied in chlorine-free solvents such as toluene, are easily accessible, and can be handled at room temperature and in laboratory atmospheres for brief periods, but they are sensitive to excess water, thereby losing their catalytic activity. Replacing the acetonitrile ligands by benzonitrile ligands improves the solubility and catalytic activity in nonpolar and nonchlorinated solvents. However, the benzonitrile copper(II) compounds have lower thermal stability than their acetonitrile congeners. PMID:18637647

Li, Yang; Voon, Lih Ting; Yeong, Hui Yee; Hijazi, Ahmed K; Radhakrishnan, Narayanan; Khler, Klaus; Voit, Brigitte; Nuyken, Oskar; Khn, Fritz E

2008-01-01

38

Preparation of coal slurry with organic solvents.  

PubMed

In this study, various organic solvents were used to prepare coal slurries and the rheological and thermal properties of coal-organic solvent slurries were examined. Solvents with molecules containing unpaired electrons (high basicity) show high extraction power and cause swelling of coal. Therefore, coal-organic solvent slurries usually showed higher viscosities compared to coal-water slurry. In addition, coal slurries prepared by alcohols and cyclohexanone demonstrated lower settling rates but a high specific sedimentation volume presumably because these solvents swelled coal particles well and led to the formation of weak gel structures in the bulk. In addition, ethanol and cyclohexanone are capable of breaking a considerable amount of hydrogen bonds in coal and subsequently opening up the structures. Thus, more surface area is available for combustion and the combustion rate of coal slurries was increased. PMID:17276487

Shin, Yu-Jen; Shen, Yun-Hwei

2007-06-01

39

Coordination polymers  

Microsoft Academic Search

This paper is a review of the metal complex forming coordination polymers. A polymermetal complex is composed of synthetic polymer and metal ions bound to the polymer ligand by a coordinate bond. A polymer ligand contains anchoring sites like nitrogen, oxygen or sulphur obtained either by the polymerization of monomer possessing the coordinating site or by a chemical reaction between

T. Kaliyappan; P. Kannan

2000-01-01

40

Solvent wash solution  

DOEpatents

Process 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 volume percent 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, James C. (Blackville, SC)

1986-01-01

41

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

42

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

43

Weakly sufficient quantum statistics  

E-print Network

Some aspects of weak sufficiency of quantum statistics are investigated. In particular, we give necessary and sufficient conditions for the existence of a weakly sufficient statistic for a given family of vector states, investigate the problem of its minimality, and find the relation between weak sufficiency and other notions of sufficiency employed so far.

Katarzyna Lubnauer; Andrzej ?uczak; Hanna Pods?dkowska

2009-11-23

44

Synesthesia: Strong and Weak  

Microsoft Academic Search

In this review, we distinguish strong and weak forms of synesthesia. Strong synesthesia is characterized by a vivid image in one sensory modality in response to stimulation in another one. Weak synesthesia is characterized by cross-sensory correspondences expressed through language, perceptual similarity, and perceptual interactions during information processing. Despite important phenomenological dissimilarities between strong and weak synesthesia, we maintain that

Gail Martino; Lawrence E. Marks

2001-01-01

45

Solvent effects on fluorescence properties of protochlorophyll and its derivatives with various porphyrin side chains  

Microsoft Academic Search

Fluorescence spectra and fluorescence lifetimes of protochlorophyll (Pchl) were measured in organic solvents having different\\u000a physical and chemical properties and were analyzed taking into account the nonspecific (dependent on bulk solvent parameters),\\u000a and specific (e.g. H bonds, Mg coordination) solventsolute interactions. The energy of the fluorescence emission band decreased,\\u000a while the Stokes shift increased for increasing solvent orientation polarizability, which

Beata My?liwa-Kurdziel; Katalin Solymosi; Jerzy Kruk; Bla Bddi; Kazimierz Strza?ka

2008-01-01

46

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...

47

Solvent-free synthesis  

EPA Science Inventory

This chapter gives a brief introduction about solvent-free reactions whose importance can be gauged by the increasing number of publications every year during the last decade. The mechanistic aspects of the reactions under solvent-free conditions have been highlighted. Our observ...

48

Weak greedy algorithms  

Microsoft Academic Search

Theoretical greedy type algorithms are studied: a Weak Greedy Algorithm, a Weak Orthogonal Greedy Algorithm, and a Weak Relaxed\\u000a Greedy Algorithm. These algorithms are defined by weaker assumptions than their analogs the Pure Greedy Algorithm, an Orthogonal\\u000a Greedy Algorithm, and a Relaxed Greedy Algorithm. The weaker assumptions make these new algorithms more ready for practical\\u000a implementation. We prove the convergence

Vladimir N. Temlyakov

2000-01-01

49

Reaction coordinate in electron transfer: What physical quantity should we use for it?  

SciTech Connect

In the Marcus theory of electron transfer the reaction coordinate due to solvent motion plays a central role. In 1991,Zhu and Rasaiah [J. Chem. Phys.95, 3325 (1991)] tried to define the reaction coordinate in terms of the solvent orientational polarization function. However, their definition is not consistent with the associated free energy curves as functions of the reaction coordinate. The appropriate definition of the reaction coordinate and the associated free energy curves are presented.

Tachiya, M. [National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 5, Tsukuba, Ibaraki 305-8565 (Japan)

2008-08-14

50

Weak Probabilistic Anonymity  

Microsoft Academic Search

Anonymity means that the identity of the user performing a certain action is main- tained secret. The protocols for ensuring anonymity often use random mechanisms which can be described probabilistically. In this paper we propose a notion of weak probabilistic anonymity, where weak refers to the fact that some amount of proba- bilistic information may be revealed by the protocol.

Yuxin Deng; Catuscia Palamidessi; Jun Pang

2007-01-01

51

Conformational transitions of a weak polyampholyte.  

PubMed

Using grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain. PMID:25296835

Narayanan Nair, Arun Kumar; Uyaver, Sahin; Sun, Shuyu

2014-10-01

52

Conformational transitions of a weak polyampholyte  

NASA Astrophysics Data System (ADS)

Using grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain.

Narayanan Nair, Arun Kumar; Uyaver, Sahin; Sun, Shuyu

2014-10-01

53

CHLORINATED SOLVENT PLUME CONTROL  

EPA Science Inventory

This lecture will cover recent success in controlling and assessing the treatment of shallow ground water plumes of chlorinated solvents, other halogenated organic compounds, and methyl tert-butyl ether (MTBE)....

54

Hydrogen Bond Lifetimes and Energetics for Solute/Solvent Complexes Studied with 2D-IR Vibrational Echo Spectroscopy  

E-print Network

Hydrogen Bond Lifetimes and Energetics for Solute/Solvent Complexes Studied with 2D-IR Vibrational@stanford.edu Abstract: Weak hydrogen-bonded solute/solvent complexes are studied with ultrafast two the dissociation and formation rates of the hydrogen-bonded complexes. The dissociation rates of the weak hydrogen

Fayer, Michael D.

55

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. PMID:11094414

Garabrant, David H; Dumas, Constantine

2000-01-01

56

Solvent-free Reactions  

Microsoft Academic Search

For reasons of economy and pollution, solvent-free methods are of great interest in order to modernize classical procedures\\u000a making them more clean, safe and easy to perform. Reactions on solid mineral supports, reactions without any solvent\\/support\\u000a or catalyst, and solid-liquid phase transfer catalysis can be thus employed with noticeable increases in reactivity and selectivity.\\u000a A comprehensive review of these techniques

Andr Loupy

57

Cleaning without chlorinated solvents  

NASA Technical Reports Server (NTRS)

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 percent. 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.

1995-01-01

58

Prediction of Coordination Number and Relative Solvent Accessibility in Proteins  

E-print Network

Department of Biological Chemistry, College of Medicine, University of California, Irvine, California 3 contact map from the primary sequence and these attributes is emerging as a promising strategy for solving

Pollastri, Gianluca

59

How Do Teachers Coordinate Their Work? A Framing Approach  

ERIC Educational Resources Information Center

Since the 1970s, schools have been characterized as loosely coupled systems, meaning that the teachers' work is weakly coordinated at the local level. Nonetheless, few studies have focused on the local variations of coordination modes, their sources and their nature. In this article, the process of local coordination of the teachers'

Dumay, Xavier

2014-01-01

60

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

61

Solvent interactions of halophilic malate dehydrogenase.  

PubMed

Malate dehydrogenase from the extreme halophilic Haloarcula marismortui (Hm MalDH) is an acidic protein that is unstable below molar salt concentrations. The solvated folded protein was studied by small-angle neutron scattering in solvents containing salt: NaCl, NaCH(3)CO(2), KF, NH(4)Cl, NH(4)CH(3)CO(2), (NH(4))(2)SO(4), MgCl(2), and MgSO(4). It was found that the global solvent interactions depend mainly on the nature of the cation. Complementary mass density measurements in MgCl(2), NaCl, NaCH(3)CO(2), and (NH(4))(2)SO(4) allowed determining the partial molal volumes of the protein, which were found to increase slightly with the salt, and the preferential salt binding parameters for each solvent condition. These are strongly dependent on the cation type and salt concentration. Hm MalDH can be modeled as an invariant particle binding 4100 water molecules in MgCl(2) and 2000 +/- 200 in NaCl, NaCH(3)CO(2), or (NH(4))(2)SO(4). The number of salt molecules associated to the particle decreases from about 85 to 0 in the order MgCl(2) > NaCl = NaCH(3)CO(2) > (NH(4))(2)SO(4). Alternatively, we considered exchangeable sites for water and salt with the effects of solvent nonideality. It does not change the description of the solvent interactions. Solvent anions act on Hm MalDH stability through a limited number of strong binding sites, as those seen at the interfaces of Hm MalDH by crystallography. Cations would act through some strong and numerous weak binding sites defined on the folded protein, in possible addition to nonspecific hydration effects. PMID:12403625

Ebel, Christine; Costenaro, Lionel; Pascu, Mihaela; Faou, Pierre; Kernel, Blandine; Proust-De Martin, Flavien; Zaccai, Giuseppe

2002-11-01

62

Unusual metal coordination chemistry from an amino-amide derivative of 4-nitrophenol, a surprising ligand.  

PubMed

The simple ligand N-(2-aminoethyl)-2-hydroxy-5-nitrobenzamide () exhibits several coordination modes depending on the reaction conditions, acting as a zwitterion on its own or being ionic in the presence of acid and depending on the concentration of metal present in a reaction, it can coordinate to the metal in either a 1:1 or a 1:2 metal:ligand mode. Furthermore, the role of solvent plays an important role in these complexation reactions with both four and six coordinate copper complexes being obtained using water as solvent but only six coordinate copper complexes obtained using acetonitrile as solvent. PMID:19789795

McGinley, John; McKee, Vickie; Toftlund, Hans; Walsh, John M D

2009-10-21

63

Solvent resistant copolyimide  

NASA Technical Reports Server (NTRS)

A solvent resistant copolyimide was prepared by reacting 4,4'-oxydiphthalic anhydride with a diaimine blend comprising, based on the total amount of the diamine blend, about 75 to 90 mole percent of 3,4'-oxydianiline and about 10 to 25 mole percent p-phenylene diamine. The solvent resistant copolyimide had a higher glass transition temperature when cured at 350.degree. , 371.degree. and 400.degree. C. than LaRC.TM.-IA. The composite prepared from the copolyimide had similar mechanical properties to LaRC.TM.-IA. Films prepared from the copolyimide were resistant to immediate breakage when exposed to solvents such as dimethylacetamide and chloroform. The adhesive properties of the copolyimide were maintained even after testing at 23.degree., 150.degree., 177.degree. and 204.degree. C.

Chang, Alice C. (Inventor); St. Clair, Terry L. (Inventor)

1995-01-01

64

Solvent free triglyceride synthesis using lipozyme TM IM20  

Microsoft Academic Search

Summary The synthesis of triglycerides using LipozymeTM IM-20 (Mucor miehei lipase immobilized on weak anion exchange resins by Novo) is described. Use of pure substrates in stoichiometric amounts in the absence of any organic solvent enables high conversion to be obtained with the addition of molecular sieves to remove water produced by the reaction.

F. Ergan; M. Trani; G. Andr

1988-01-01

65

Weak bump quasars  

NASA Technical Reports Server (NTRS)

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

66

Solubilities of p-nitroanilines in various classes of solvents. Specific solute-solvent interactions  

NASA Astrophysics Data System (ADS)

The solubilities ? B in volume fractions of p-nitroaniline (PNA) and N,N-dimethyl p-nitroaniline (N,N-PNA) were determined near 25C in some 40 solvents belonging to different classes using a thermoturbidimetric method. The ratio between the solubilities of the two compounds can be corrected for the differences in the melting characteristics determined from DSC measurements. The solubilities at 25C of N,N-PNA have then to be multiplied by the factor 2.72. The corrected ratios {? PNA}/{?? N,N-PNA} give indications on the formation of H-bonds between the solvent molecules and the NH groups of PNA. This is observed in solvent classes with electron donor oxygens like sulfoxides, ketones, esters and cyclic ethers. However, the ratio {? PNA}/{?? N,N-PNA} decreases in an homologous series when the molar volume of the solvent increases, indicating that the formation of H-bonds by PNA depends also on the concentration of the active sites in the solvent and that not all the PNA molecules are involved in H-bonding. {? PNA}/{?? N,N-PNA} is also markedly larger than 2 in the lower alcohols demonstrating the formation of N-H?O hydrogen bonds at the end of the self-association chains. The fraction ? of the PNA molecules escaping from H-bonding in the electron donor solvents and in alcohols is quantitatively estimated from the solubility using the equations of the theory of the mobile order and disorder of Huyskens and Ruelle. In nitriles a weak formation of N-H?H?C bonds is observed. In contrast H-bonds are not observed in nitroalkanes. Unexpectedly the ratio's {? PNA}/{?? N,N-PNA} are much smaller than 1 in chloro alkanes. The formation of EDA bonds between N,N-PNA and these solvents acting as Lewis acids is therefore probable.

Huyskens, Franois; Morissen, Heidi; Huyskens, Pierre

1998-01-01

67

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. The technologies were (1) atmospheric batch distillation, (2) vacuum heat-pump distillation, and (3) low-emission vapor degreas...

68

Solvent free permanganate oxidations  

Microsoft Academic Search

The oxidations of organic compounds by permanganate under solvent free conditions have been studied. Thiols and primary aromatic amines undergo oxidative coupling reactions to give disulfides and diazenes, respectively, sulfides are oxidized to sulfones, primary and secondary alcohols are converted to aldehydes and ketones, 1,4-diols and cyclic ethers give lactones and arenes are oxidized to the corresponding ?-ketones. The experimental

Ahmad Shaabani; Donald G. Lee

2001-01-01

69

SOLVENT EXTRACTION TREATMENT  

EPA Science Inventory

Solvent extraction does not destroy wastes, but is a means of separating hazardous contaminants from soils, sludges, and sediments, thereby reducing the volume of the hazardous waste that must be treated. enerally it is used as one ina series of unit operations, and can reduce th...

70

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 . In the hydrated and dimethylsulfoxide solvated oxovanadium(IV) ions vanadium binds strongly to an oxo group at ca. 1.6 . The solvent molecule trans to the oxo group is very weakly bound, at ca. 2.2 , while the remaining four solvent molecules, with a mean V-O bond distance of 2.0 , 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 , 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 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 , while the remaining two have bond distances of 2.02 . 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

2012-01-01

71

Conversation and Coordinative Structures  

Microsoft Academic Search

People coordinate body postures and gaze patterns during conversation. We review literature showing that (1) action embodies cognition, (2) postural coordination emerges spontaneously when two people converse, (3) gaze patterns influence postural coordination, (4) gaze coordination is a function of common ground knowledge and visual information that conversants believe they share, and (5) gaze coordination is causally related to mutual

Kevin Shockley; Daniel C. Richardson; Rick Dalec

2009-01-01

72

MUTAGENICITY OF SELECTED ORGANIC SOLVENTS  

EPA Science Inventory

Mutagenicity of selected organic solvents. Scand J Work Environ Health 11 (1985): suppl 1, 75-82. For certain organic solvents, such as benzene, vinyl chloride, styrene, technical grade trichloroethylene, and acrylonitrile, the available studies provide convincing evidence to dem...

73

DESIGNING ENVIRONMENTALLY BENIGN SOLVENT SUBSTITUTES  

EPA Science Inventory

Since the signing of 1987 Montreal Protocol, reducing and eliminating the use of harmful solvents has become an internationally imminent environmental protection mission. Solvent substitution is an effective way to achieve this goal. The Program for Assisting the Replacement of...

74

Weak Polarized Electron Scattering  

E-print Network

Scattering polarized electrons provides an important probe of the weak interactions. Precisely measuring the parity-violating left-right cross section asymmetry is the goal of a number of experiments recently completed or in progress. The experiments are challenging, since A_{LR} is small, typically between 10^(-4) and 10^(-8). By carefully choosing appropriate targets and kinematics, various pieces of the weak Lagrangian can be isolated, providing a search for physics beyond the Standard Model. For other choices, unique features of the strong interaction are studied, including the radius of the neutron density in heavy nuclei, charge symmetry violation, and higher twist terms. This article reviews the theory behind the experiments, as well as the general techniques used in the experimental program.

Jens Erler; Charles J. Horowitz; Sonny Mantry; Paul A. Souder

2014-01-23

75

Weak Polarized Electron Scattering  

E-print Network

Scattering polarized electrons provides an important probe of the weak interactions. Precisely measuring the parity-violating left-right cross section asymmetry is the goal of a number of experiments recently completed or in progress. The experiments are challenging, since A_{LR} is small, typically between 10^(-4) and 10^(-8). By carefully choosing appropriate targets and kinematics, various pieces of the weak Lagrangian can be isolated, providing a search for physics beyond the Standard Model. For other choices, unique features of the strong interaction are studied, including the radius of the neutron density in heavy nuclei, charge symmetry violation, and higher twist terms. This article reviews the theory behind the experiments, as well as the general techniques used in the experimental program.

Erler, Jens; Mantry, Sonny; Souder, Paul A

2014-01-01

76

Weak Polarized Electron Scattering  

NASA Astrophysics Data System (ADS)

Scattering polarized electrons provides an important probe of the weak interactions. Precisely measuring the parity-violating leftright cross-section asymmetry (ALR) is the goal of a number of experiments that have recently been completed or are in progress. The experiments are challenging, given that ALR is small, typically between 10?4 and 10?8. By carefully choosing appropriate targets and kinematics, one can isolate various pieces of the weak Lagrangian, providing a search for physics beyond the Standard Model. For other choices, unique features of the strong interaction are being studied, including the radius of the neutron density in heavy nuclei, charge symmetry violation, and higher-twist terms. This article reviews the theory behind the experiments, as well as the general techniques used in the experimental program.

Erler, Jens; Horowitz, Charles J.; Mantry, Sonny; Souder, Paul A.

2014-10-01

77

Weak Gravitational Lensing  

NASA Astrophysics Data System (ADS)

This chapter reviews the data mining methods recently developed to solve standard data problems in weak gravitational lensing. We detail the different steps of the weak lensing data analysis along with the different techniques dedicated to these applications. An overview of the different techniques currently used will be given along with future prospects. Until about 30 years ago, astronomers thought that the Universe was composed almost entirely of ordinary matter: protons, neutrons, electrons, and atoms. The field of weak lensing has been motivated by the observations made in the last decades showing that visible matter represents only about 4-5% of the Universe (see Figure 14.1). Currently, the majority of the Universe is thought to be dark, that is, does not emit electromagnetic radiation. The Universe is thought to be mostly composed of an invisible, pressure less matter - potentially relic from higher energy theories - called "dark matter" (20-21%) and by an even more mysterious term, described in Einstein equations as a vacuum energy density, called "dark energy" (70%). This "dark" Universe is not well described or even understood; its presence is inferred indirectly from its gravitational effects, both on the motions of astronomical objects and on light propagation. So this point could be the next breakthrough in cosmology. Today's cosmology is based on a cosmological model that contains various parameters that need to be determined precisely, such as the matter density parameter Omega_m or the dark energy density parameter Omega_lambda. Weak gravitational lensing is believed to be the most promising tool to understand the nature of dark matter and to constrain the cosmological parameters used to describe the Universe because it provides a method to directly map the distribution of dark matter (see [1,6,60,63,70]). From this dark matter distribution, the nature of dark matter can be better understood and better constraints can be placed on dark energy, which affects the evolution of structures. Gravitational lensing is the process by which light from distant galaxies is bent by the gravity of intervening mass in the Universe as it travels toward us. This bending causes the images of background galaxies to appear slightly distorted, and can be used to extract important cosmological information. In the beginning of the twentieth century, A. Einstein predicted that massive bodies could be seen as gravitational lenses that bend the path of light rays by creating a local curvature in space time. One of the first confirmations of Einstein's new theory was the observation during the 1919 solar eclipse of the deflection of light from distant stars by the sun. Since then, a wide range of lensing phenomena have been detected. The gravitational deflection of light by mass concentrations along light paths produces magnification, multiplication, and distortion of images. These lensing effects are illustrated by Figure 14.2, which shows one of the strongest lenses observed: Abell 2218, a very massive and distant cluster of galaxies in the constellation Draco. The observed gravitational arcs are actually the magnified and strongly distorted images of galaxies that are about 10 times more distant than the cluster itself. These strong gravitational lensing effects are very impressive but they are very rare. Far more prevalent are weak gravitational lensing effects, which we consider in this chapter, and in which the induced distortion in galaxy images is much weaker. These gravitational lensing effects are now widely used, but the amplitude of the weak lensing signal is so weak that its detection relies on the accuracy of the techniques used to analyze the data. Future weak lensing surveys are already planned in order to cover a large fraction of the sky with high accuracy, such as Euclid [68]. However, improving accuracy also places greater demands on the methods used to extract the available information.

Pires, Sandrine; Starck, Jean-Luc; Leonard, Adrienne; Rfrgier, Alexandre

2012-03-01

78

Focus Sensitive Coordination  

E-print Network

This thesis investigates the role of the Focus Sensitive Operators (FSOs) even and also when found inside of a coordination. Coordinations of this form are called Focus Sensitive Coordinations (FSC) and include or even, ...

Hulsey, Sarah McNearney

2008-01-01

79

Hazardous solvent substitution  

SciTech Connect

Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is `What can we use as replacements for hazardous solvents?`You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product`s constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace.

Twitchell, K.E.

1995-11-01

80

Colorimetric Solvent Indicators Based on Nafion Membranes Incorporating Nickel(II)-Chelate Complexes.  

PubMed

To develop solvent-recognition films, Nafion membranes incorporating cationic nickel-chelate complexes, that is, [Ni(L(1) )(L(2) )](+) (HL(1) =acetylacetone, 2,2,6,6-tetramethyl-3,5-heptanedione; L(2) =N,N-diethylethylenediamine, N-butyl-N,N',N'-trimethylethylenediamine), were prepared. Immersion of the films in various solvents effected the color changes varying from red to pale blue green depending on the donor number of the solvents. The color change is based on an equilibrium shift between square-planar and solvent-coordinated octahedral geometries of the cations. The degree of the color change depended on the affinity of the incorporated complex to the solvent molecules. The films were robust and exhibited a reversible solvent response. The films exhibited thermochromism when a small amount of appropriate solvents were incorporated and changed from pale blue green at low temperatures to red at high temperatures. PMID:25308167

Hosokawa, Hitoshi; Funasako, Yusuke; Mochida, Tomoyuki

2014-11-10

81

Outreach Coordination for the Plasma Sciences  

Microsoft Academic Search

Outreach for the plasma sciences has adapted to multiple levels and venues for communicating the excitement and possibilities of the field. The internet and web are the most important new media for such public outreach. Nevertheless, a variety of outreach methods and coordination efforts will always be valuable because of their various strengths and weaknesses and the need to address

Timothy Eastman

2001-01-01

82

Next Generation Solvent Development for Caustic-Side Solvent Extraction of Cesium  

SciTech Connect

This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University developed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Inter Laboratory efforts were coordinated in complementary fashion with engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

Duncan, Nathan C [ORNL; Delmau, Laetitia Helene [ORNL; Ensor, Dale [Tennessee Technological University; Lee, Denise L [ORNL; Birdwell Jr, Joseph F [ORNL; Hill, Talon G [ORNL; Williams, Neil J [ORNL; Stoner, Erica L [ORNL; Roach, Benjamin D [ORNL; Moyer, Bruce A [ORNL; Sloop Jr, Frederick {Fred} V [ORNL

2013-07-01

83

Inherent weaknesses of cosmology  

NASA Technical Reports Server (NTRS)

Sources of astrophysical evidence necessary to verify a cosmological model are reviewed. Cosmological history of the universe is divided into four epochs, each unique in its physical conditions related to observability at present. The current epoch, started after recombination of hydrogen in the universe, offers the most in observability. In earlier epochs, verifiable astrophysical evidence gradually disappeared. It seems that no astrophysical evidence has been left behind from the singularity epoch of the Universe. The gradual disappearance of astrophysical evidence ascertainable at present is the result of physical conditions structured within the cosmological models, hence indicating certain inherent weaknesses of cosmology as a verifiable physical theory.

Chiu, H.-Y.

1986-01-01

84

A thermodynamic study of selective solvation in solvent mixtures.  

PubMed

Changes in the (31)P NMR chemical shift of tri-n-butylphosphine oxide have been measured as function of solvent composition in a number of binary solvent mixtures. The data were analysed using a model that separates the contributions of specific H-bond interactions with the first solvation shell and the non-specific effects of the bulk solvent on the chemical shift. This allowed measurement of equilibrium constants between differently solvated states of the probe and hence thermodynamic quantification of preferential solvation in the binary mixtures. The results are analysed in the context of the electrostatic solvent competition model, which assumes that solvent effects on intermolecular interactions can be interpreted based on the exchange of specific functional group contacts, with minimal involvement of the bulk solvent. The thermodynamic measurements of preferential solvation were used to determine the H-bond donor parameter alpha for cyclohexane, n-octane, n-dodecane, benzene, 1,4-dioxane, carbon tetrachloride, acetone, dichloromethane, dimethyl sulfoxide and chloroform. For solvents where the H-bond donor parameters have been measured as solutes in carbon tetrachloride solution, the H-bond donor parameters measured here for the same compounds as solvents are practically identical, i.e. solute and solvent H-bond parameters are directly interchangable. For alkanes, the experimental H-bond donor parameter is significantly larger than expected based on calculated molecular electrostatic potential surfaces. This might suggest an increase in the relative importance of van der Waals interactions when electrostatic effects are weak. PMID:20449502

Cabot, Rafel; Hunter, Christopher A

2010-04-21

85

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 OP 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. PMID:23009395

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

2012-01-01

86

Exploring the reactivity of four-coordinate PNPCoX with access to three-coordinate spin triplet PNPCo.  

PubMed

The compounds (PNP)CoX, where PNP is (tBu2PCH2SiMe2)2N- and X is Cl, I, N3, OAr, OSO2CF3 and N(H)Ar, are reported. Some of these show magnetic susceptibility, color, and 1H NMR evidence of being in equilibrium between a blue, tetrahedral S=3/2 state and a red, planar S=1/2 state; the equilibrium populations are influenced by subtle solvent effects (e.g., benzene and cyclohexane are different), as well as by temperature. Attempted oxidation to Co(III) with O2 occurs instead at phosphorus, giving [P(O)NP(O)]CoX species. The single O-atom transfer reagent PhI=O likewise oxidizes P. Even I2 oxidizes P to give the pendant phosphonium species (tBu2P(I)CH2SiMe2NSiMe2CH2PtBu2)CoI2 with a tetrahedral S=3/2 cobalt; the solid-state structure shows intermolecular PI...ICo interactions. Attempted alkyl metathesis of PNPCoX inevitably results in reduction, forming PNPCo, which is a spin triplet with planar T-shaped coordination geometry with no agostic interaction. Triplet PNPCo binds N2(weakly) and CO (whose low CO stretching frequency indicates strong PNP-->Co donor power), but not ethene or MeCCMe. PMID:17956087

Ingleson, Michael J; Pink, Maren; Fan, Hongjun; Caulton, Kenneth G

2007-11-26

87

Acceleration of Nucleophilic CH Activation by Strongly Basic Solvents Brian G. Hashiguchi,  

E-print Network

(e.g., by protonation of coordinated water) and CH cleavage by increasing catalyst electrophilicity.4 J. H. Young, Muhammed Yousufuddin,§ William A. Goddard III,| and Roy A. Periana*, The Scripps Energy coordination.3 We have shown that an essential role of the strong acid solvent is ligand protonation

Goddard III, William A.

88

Solvent Fractionation of Lignin  

SciTech Connect

Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. The major issues for the commercial production of value added high performance lignin products are lignin s physical and chemical heterogenities. To overcome these problems, a variety of procedures have been developed to produce pure lignin suitable for high performace applications such as lignin-derived carbon materials. However, most of the isolation procedures affect lignin s properties and structure. In this chapter, a short review of the effect of solvent fractionation on lignin s properties and structure is presented.

Chatterjee, Sabornie [ORNL; Saito, Tomonori [ORNL

2014-01-01

89

Calculation of analytical gradients for solvation energy over atoms coordinates  

E-print Network

In the given paper we describe methods finding analytical gradients (derivatives) of solvation energy over atoms coordinates. It is made both for not polar energy and for the polar energy found by methods PCM, COSMO and SGB. These gradients are searched with use of analytical gradients of parameters (coordinates, normal vectors and squares) the surface meshes. The surface meshes are located on both the optimal smooth molecular surfaces: solvent excluded surface (SES) and surface solvent accessible surface (SAS) received from SES. These surfaces are found by methods of primary and secondary rolling according to the algorithm described in the previous papers of the series.

Kupervasser, Oleg

2011-01-01

90

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

91

Weak localization and weak anti-localization in topological insulators  

NASA Astrophysics Data System (ADS)

Weak localization and weak anti-localization are quantum interference effects in quantum transport in a disor- dered electron system. Weak anti-localization enhances the conductivity and weak localization suppresses the conductivity with decreasing temperature at very low temperatures. A magnetic field can destroy the quantum interference effect, giving rise to a cusp-like positive and negative magnetoconductivity as the signatures of weak localization and weak anti-localization, respectively. These effects have been widely observed in topological in- sulators. In this article, we review recent progresses in both theory and experiment of weak (anti-)localization in topological insulators, where the quasiparticles are described as Dirac fermions. We predicted a crossover from weak anti-localization to weak localization if the massless Dirac fermions (such as the surface states of topo- logical insulator) acquire a Dirac mass, which was confirmed experimentally. The bulk states in a topological insulator thin film can exhibit the weak localization effect, quite different from other system with strong spin- orbit interaction. We compare the localization behaviors of Dirac fermions with conventional electron systems in the presence of disorders of different symmetries. Finally, we show that both the interaction and quantum interference are required to account for the experimentally observed temperature and magnetic field dependence of the conductivity at low temperatures.

Lu, Hai-Zhou; Shen, Shun-Qing

2014-08-01

92

Uranyl-oxo coordination directed by non-covalent interactions.  

PubMed

Directed coordination of weakly Lewis acidic K(+) ions to weakly Lewis basic uranyl oxo ligands is accomplished through non-covalent cation-? and cation-F interactions for the first time. Comparison of a family of structurally related diarylamide ligands highlights the role that the cation-? and cation-F interactions play in guiding coordination. Cation binding to uranyl is demonstrated in the solid state and in solution, providing the shortest reported crystallographic uranyl-oxo to potassium distance. UV-Vis, TD-DFT calculations, and electrochemical measurements show that cation coordination directly impacts the electronics at the uranium(vi) cation. PMID:24894554

Lewis, Andrew J; Yin, Haolin; Carroll, Patrick J; Schelter, Eric J

2014-07-28

93

Numerical calculation of concentration distribution and dimensional change for constant-rate diffusion of a solute into a Solvents surface  

Microsoft Academic Search

Modified coordinate systems, such as have been utilized in the determination of mutual diffusion coefficients where volume\\u000a changes occur, have been utilized in solving for concentration distributions and dimensional changes resulting from diffusion\\u000a of a solute into a substrate solvents surface. Developed equations have been solved, utilizing simple explicit finite difference\\u000a methods, for two example cases. In both examples the

Robert L. Benedetti; Donald L. Creighton

1970-01-01

94

Solute-Solvent Complex Kinetics and Thermodynamics Probed by 2D-IR Vibrational Echo Chemical Exchange Spectroscopy  

E-print Network

temperature. The correlation between the complex enthalpies of formation and dissociation rate constants can/mol. It was found that the inverse of the solute-solvent complex dissociation rate constant is linearly related, 2008 The formation and dissociation kinetics of a series of triethylsilanol/solvent weakly hydrogen

Fayer, Michael D.

95

Fully atomistic simulations of the response of silica nanoparticle coatings to alkane solvents.  

PubMed

Molecular dynamics simulations are used to study the effect of passivating ligands of varying lengths grafted to a nanoparticle and placed in various alkane solvents. Average height and density profiles for methyl-terminated alkoxylsilane ligands (-O-Si(OH)(2)(CH(2))(n)CH(3), with n = 9, 17, and 35) attached to a 5-nm-diameter amorphous silica nanoparticle with coverages of between 1.0 and 3.0 chains/nm(2) are presented for explicitly modeled, short-chain hydrocarbon solvents and for implicit good and poor solvents. Three linear solvents, C(10)H(22) (decane), C(24)H(50), and C(48)H(96), and a branched solvent, squalene, were studied. An implicit poor solvent captured the effect of the longest chain length solvent at lower temperatures, while its temperature dependence was similar to that of the branched solvent squalene. In contrast, an implicit good solvent produced coating structures that were far more extended than those found in any of the explicit solvents tested and showed little dependence on temperature. Coatings equilibrated in explicit solvents were more compact in longer-chain solvents because of autophobic dewetting. Changes in the coating density profiles were more pronounced as the solvent chain length was increased from decane to C(24)H(50) than from C(24)H(50) to C(48)H(98) for all coatings. The response of coatings in squalene was not significantly different from that of the linear chain of equal mass. Significant interpenetration of the solvent chains with the brush coating was observed only for the shortest grafted chains in decane. In all cases, the methyl terminal group was not confined to the coating edge but was found throughout the entire coating volume, from the core to the outermost shell. Increasing the temperature from 300 to 500 K led to greater average brush heights, but the dependence was weak. PMID:22931425

Peters, Brandon L; Lane, J Matthew D; Ismail, Ahmed E; Grest, Gary S

2012-12-18

96

Hand Eye Coordination  

E-print Network

This paper describes a simple method of converting visual coordinates to arm coordinates which does not require knowledge of the position of the camera(s). Comparisons are made to other methods and two camera, three ...

Speckert, Glen

97

Method for regenerating scale solvent  

SciTech Connect

This patent describes improvement in the method for removing alkaline earth sulfate scale by contacting the scale with an aqueous solvent having a pH of about 8 to abut 14 and comprising a chelating agent comprising a polyaminopolycarboxylic acid or salt of such an acid, and a synergist anion. The improvement comprises removing alkaline earth sulfate scale dissolved in the aqueous solvent by: acidifying the aqueous solvent containing dissolved scale sufficiently to generate free alkaline earth metal ions without forming an insoluble alkaline earth precipitate; mixing the aqueous solvent with a liquid hydrocarbonaceous membrane phase containing a soluble surfactant and an oil soluble emulsifier, the liquid membrane emulsion enveloped around droplets of an internal aqueous phase comprising an aqueous solution having a pH of from about 8 to about 14 and a chelating agent comprising a polyaminopolycarboxylic acid or a salt of such an acid, wherein the free alkaline earth ions transfer from the solvent into the hydrocarbonaceous membrane and into the internal aqueous phase where the ions are removed by the chelating agent; and recovering the aqueous solvent and increasing the pH of the aqueous solvent to a value of about 10 to about 14 to produce a regenerated aqueous solvent for reuse.

Morris, R.L.; Paul, J.M.

1992-02-11

98

Simple Coordinates Game  

NSDL National Science Digital Library

In this activity, students enter in coordinates then the applet places a house at that location, or the location is decided first then the student must enter in the coordinates of the house. This activity allows students to practice with coordinates and ordered pairs in the Cartesian coordinate system. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

99

Evolution of Dynamic Coordination  

E-print Network

5 Evolution of Dynamic Coordination Evan Balaban, Shimon Edelman, Sten Grillner, Uri Grodzinski comparative biology provide for furthering scienti¿c un- derstanding of the evolution of dynamic coordination structures, neural functions, and behavioral coordination. Below we present an overview of neural machinery

Jarvis, Erich D.

100

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

101

MISCELLANEA Spherical Coordinates  

E-print Network

and to denote polar coordinates. Most American calculus texts also utilize in spherical coordinates coordinate. There is however a much more serious problem. Several of the most commonly used calculus texts overnight from driving on the left to driving on the right! We argue that the conflict between the different

102

COMPUTER AIDED SOLVENT DESIGN FOR THE ENVIRONMENT  

EPA Science Inventory

Solvent substitution is an effective and useful means of eliminating the use of harmful solvents, but finding substitute solvents which are less harmful and as effective as currently used solvents presents significant difficulties. Solvent substitution is a form of reverse engin...

103

Weak Measurements of Light Chirality with a Plasmonic Slit  

E-print Network

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 post-selection 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 advantages of (i) quantum weak measurements, (ii) near-field plasmonic systems, and (iii) high-numerical aperture microscopy in employing spin-orbit interaction of light and probing light chirality.

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

2012-04-02

104

Acquired intolerance to organic solvents and results of vestibular testing  

SciTech Connect

Among 160 consecutive patients referred to the Clinic of Occupational Medicine, Rigshospitalet, for symptoms connected with exposure to organic solvents, 20 exhibited symptoms of acquired intolerance to minor amounts of organic solvents. Later, an additional 30 consecutive patients with symptoms of acquired intolerance were included, yielding a total of 43 men and 7 women. The characteristics of the clinical syndrome described are complaints of dizziness, nausea, and weakness after exposure to minimal solvent vapor concentrations. After having tolerated long-term occupational exposure to moderate or high air concentrations of various organic solvents, the patients became intolerant within a short period of time. Since dizziness was a frequent complaint, we tried to obtain a measure of the patients' complaints using vestibular tests. As a diagnostic test the combined vestibular tests had a sensitivity of 0.55 and a specificity of 0.87. No differences between patients with and without intolerance could be detected by the vestibular tests used. We conclude that acquired intolerance to organic solvents is a new but characteristic and easily recognizable syndrome, often with severe consequences for the patient's working ability.

Gyntelberg, F.; Vesterhauge, S.; Fog, P.; Isager, H.; Zillstorff, K.

1986-01-01

105

The Solvent Mediated Thermodynamics of Cellulose Deconstruction  

E-print Network

solvent accessible, chain collapse occurred spontaneously in the freeand free energy simulations of cellulose-dissolving processes are conducted in four solventFree 18 Chain System55 3.6.7 Convergence of Solvent

Gross, Adam S

2012-01-01

106

Licensing "Weak" Patents David Encaoua  

E-print Network

Licensing "Weak" Patents David Encaoua and Yassine Lefouili This Version: May 2009 Abstract In this paper, we revisit the issue of licensing "weak" patents under the shadow of litigation. Departing from industry. It is shown that the optimal two-part tariff license from the patent holder's perspective may

Paris-Sud XI, Université de

107

ON-SITE 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 low-emission vapor degreasing. The atmospheric and vacuum ...

108

Solvents and Parkinson disease: A systematic review of toxicological and epidemiological evidence  

PubMed Central

Parkinson disease (PD) is a debilitating neurodegenerative motor disorder, with its motor symptoms largely attributable to loss of dopaminergic neurons in the substantia nigra. The causes of PD remain poorly understood, although environmental toxicants may play etiologic roles. Solvents are widespread neurotoxicants present in the workplace and ambient environment. Case reports of parkinsonism, including PD, have been associated with exposures to various solvents, most notably trichloroethylene (TCE). Animal toxicology studies have been conducted on various organic solvents, with some, including TCE, demonstrating potential for inducing nigral system damage. However, a confirmed animal model of solvent-induced PD has not been developed. Numerous epidemiologic studies have investigated potential links between solvents and PD, yielding mostly null or weak associations. An exception is a recent study of twins indicating possible etiologic relations with TCE and other chlorinated solvents, although findings were based on small numbers, and doseresponse gradients were not observed. At present, there is no consistent evidence from either the toxicological or epidemiologic perspective that any specific solvent or class of solvents is a cause of PD. Future toxicological research that addresses mechanisms of nigral damage from TCE and its metabolites, with exposure routes and doses relevant to human exposures, is recommended. Improvements in epidemiologic research, especially with regard to quantitative characterization of long-term exposures to specific solvents, are needed to advance scientific knowledge on this topic. PMID:23220449

Lock, Edward A.; Zhang, Jing; Checkoway, Harvey

2013-01-01

109

Nonadiabatic dynamics of electron transfer in solution: Explicit and implicit solvent treatments that include multiple relaxation time scales  

NASA Astrophysics Data System (ADS)

The development of efficient theoretical methods for describing electron transfer (ET) reactions in condensed phases is important for a variety of chemical and biological applications. Previously, dynamical dielectric continuum theory was used to derive Langevin equations for a single collective solvent coordinate describing ET in a polar solvent. In this theory, the parameters are directly related to the physical properties of the system and can be determined from experimental data or explicit molecular dynamics simulations. Herein, we combine these Langevin equations with surface hopping nonadiabatic dynamics methods to calculate the rate constants for thermal ET reactions in polar solvents for a wide range of electronic couplings and reaction free energies. Comparison of explicit and implicit solvent calculations illustrates that the mapping from explicit to implicit solvent models is valid even for solvents exhibiting complex relaxation behavior with multiple relaxation time scales and a short-time inertial response. The rate constants calculated for implicit solvent models with a single solvent relaxation time scale corresponding to water, acetonitrile, and methanol agree well with analytical theories in the Golden rule and solvent-controlled regimes, as well as in the intermediate regime. The implicit solvent models with two relaxation time scales are in qualitative agreement with the analytical theories but quantitatively overestimate the rate constants compared to these theories. Analysis of these simulations elucidates the importance of multiple relaxation time scales and the inertial component of the solvent response, as well as potential shortcomings of the analytical theories based on single time scale solvent relaxation models. This implicit solvent approach will enable the simulation of a wide range of ET reactions via the stochastic dynamics of a single collective solvent coordinate with parameters that are relevant to experimentally accessible systems.

Schwerdtfeger, Christine A.; Soudackov, Alexander V.; Hammes-Schiffer, Sharon

2014-01-01

110

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

111

Three-coordinate, luminescent, water-soluble gold(I) phosphine complexes: structural characterization and photoluminescence  

E-print Network

Three-coordinate, luminescent, water-soluble gold(I) phosphine complexes: structural some beautiful work involving gold Abstract The trigonal planar Au(I) complex Cs8[Au(TPPTS)3]?/5.25H2O The photoluminescent properties of several types of three-coordinate gold(I) complexes in organic solvents

Abdou, Hanan E.

112

Experimental investigations of weak definite and weak indefinite noun phrases.  

PubMed

Definite noun phrases typically refer to entities that are uniquely identifiable in the speaker and addressee's common ground. Some definite noun phrases (e.g., the hospital in Mary had to go the hospital and John did too) seem to violate this uniqueness constraint. We report six experiments that were motivated by the hypothesis that these "weak definite" interpretations arise in "incorporated" constructions. Experiments 1-3 compared nouns that seem to allow for a weak definite interpretation (e.g., hospital, bank, bus, radio) with those that do not (e.g., farm, concert, car, book). Experiments 1 and 2 used an instruction-following task and picture-judgment task, respectively, to demonstrate that a weak definite need not uniquely refer. In Experiment 3 participants imagined scenarios described by sentences such as The Federal Express driver had to go to the hospital/farm. Scenarios following weak definite noun phrases were more likely to include conventional activities associated with the object, whereas following regular nouns, participants were more likely to imagine scenarios that included typical activities associated with the subject; similar effects were observed with weak indefinites. Experiment 4 found that object-related activities were reduced when the same subject and object were used with a verb that does not license weak definite interpretations. In Experiment 5, a science fiction story introduced an artificial lexicon for novel concepts. Novel nouns that shared conceptual properties with English weak definite nouns were more likely to allow weak reference in a judgment task. Experiment 6 demonstrated that familiarity for definite articles and anti-familiarity for indefinite articles applies to the activity associated with the noun, consistent with predictions made by the incorporation analysis. PMID:23685208

Klein, Natalie M; Gegg-Harrison, Whitney M; Carlson, Greg N; Tanenhaus, Michael K

2013-08-01

113

Coordinating Coordination Failures in Keynesian Models  

Microsoft Academic Search

This paper focuses on the importance of strategic complementarities in agents' payoff functions as a basis for macroeconomic coordination failures. Strategic complementarities arise when the optimal strategy of an agent depends positively upon the strategies of the other agents. The authors first analyze an abst ract game and find that multiple equilibria and a multiplier process may arise when strategic

Russell Cooper; Andrew John

1988-01-01

114

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. PMID:22984298

Levy, Neil

2012-01-01

115

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

116

Mean value coordinates  

Microsoft Academic Search

We derive a generalization of barycentric coordinates which allows a vertex in a planar triangulation to be expressed as a convex combination of its neighbouring vertices. The coordinates are motivated by the Mean Value Theorem for harmonic functions and can be used to simplify and improve methods for parameterization and morphing.

Michael S. Floater

2003-01-01

117

6. Coordination and control.  

PubMed

Any complex operation requires a system for management. In most societies, disaster management is the responsibility of the government. Coordination and control is a system that provides the oversight for all of the disaster management functions. The roles and responsibilities of a coordination and control centre include: (1) planning; (2) maintenance of inventories; (3) activation of the disaster response plan; (4) application of indicators of function; (5) surveillance; (6) information management; (7) coordination of activities of the BSFs; (8) decision-making; (9) priority setting; (10) defining overarching goal and objectives for interventions; (11) applying indicators of effectiveness; (12) applying indicators of benefit and impact; (13) exercising authority; (14) managing resources; (15) initiating actions; (16) preventing influx of unneeded resources; (17) defining progress; (18) providing information; (19) liasing with responding organisations; and (20) providing quality assurance. Coordination and control is impossible without communications. To accomplish coordination and control, three factors must be present: (1) mandate; (2) power and authority; and (3) available resources. Coordination and control is responsible for the evaluation of the effectiveness and benefits/impacts of all interventions. Coordination and control centres (CCCs) are organised hierarchically from the on-scene CCCs (incident command) to local provincial to national CCCs. Currently, no comprehensive regional and international CCCs have been universally endorsed. Systems such as the incident command system, the unified command system, and the hospital incident command system are described as are the humanitarian reform movement and the importance of coordination and control in disaster planning and preparedness. PMID:24785803

2014-05-01

118

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. Frnz; D. Harper

2002-01-01

119

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

120

Processing coordination ambiguity.  

PubMed

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 that interpretations are the result of a constraint-satisfaction process, which predicts that frequency or context can bias the parser to initially pursue a more complex interpretation.The results showed an initial preference for noun-phrase coordination, despite the fact that sentential coordination is more frequent in imperative structures. These data suggest that the parser uses a syntactic simplicity heuristic for building initial structural analyses. PMID:21313991

Engelhardt, Paul E; Ferreira, Fernanda

2010-01-01

121

Preparation of Linear ?-Conjugated Coordination Polymers Having Ruthenium(II) Complex in the Main Chain  

Microsoft Academic Search

Soluble p-conjugated coordination polymers having a ruthenium(II) complex in the main chain were prepared from a soluble metal complex monomer and a bridging ligand via coordination. Refluxing of an ethanol-water suspension containing (4,4'-dinonyl-2,2'-bipyridyl)Ru(III) with 2,3-bis(2'-pyridyl)pyrazine gave the coordination polymer. The resulting polymer was soluble in common organic solvents. The structure was confirmed by uv\\/vis spectra and gpc analysis.

Gen-ichi Konishi; Kensuke Naka; Yoshiki Chujo

1999-01-01

122

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, H.T., Jr.

1963-01-01

123

Solvent extraction of inorganic acids  

E-print Network

and solubility of nitric acid and sulfuric acid with organic solvents have been published Olander, Donadieu, and Benedict (12) studied the 'istributlon of nitric acid between water and tributyl phosphate-hexane solvent nd dcharf and Gean. . oplis (1...(. ) reported on the system nit ic acid-water-n-butyl alcohols Distribution of sulfuric acid was m-de oy Bchlea and Gean- koplis (19) with n-butyl alcohol, by Gibby ( 7) with nitro- benzene and by Peakin (14) with pyri 'in~. Baldwin, Biggies an" Soldano (2...

Ysrael, Miguel Curie

2012-06-07

124

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

125

Cosmology with weak lensing surveys  

NASA Astrophysics Data System (ADS)

Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also provide valuable cosmological information. Finally, we consider the prospects for joint analysis with other probes, such as (1) the CMB to probe background cosmology (2) galaxy surveys to probe large-scale bias and (3) Sunyaev Zeldovich surveys to study small-scale baryonic physics, and consider the lensing effect on cosmological supernova observations.

Munshi, Dipak; Valageas, Patrick; van Waerbeke, Ludovic; Heavens, Alan

2008-06-01

126

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

2010-04-01

127

Solvents and Parkinson disease: A systematic review of toxicological and epidemiological evidence  

SciTech Connect

Parkinson disease (PD) is a debilitating neurodegenerative motor disorder, with its motor symptoms largely attributable to loss of dopaminergic neurons in the substantia nigra. The causes of PD remain poorly understood, although environmental toxicants may play etiologic roles. Solvents are widespread neurotoxicants present in the workplace and ambient environment. Case reports of parkinsonism, including PD, have been associated with exposures to various solvents, most notably trichloroethylene (TCE). Animal toxicology studies have been conducted on various organic solvents, with some, including TCE, demonstrating potential for inducing nigral system damage. However, a confirmed animal model of solvent-induced PD has not been developed. Numerous epidemiologic studies have investigated potential links between solvents and PD, yielding mostly null or weak associations. An exception is a recent study of twins indicating possible etiologic relations with TCE and other chlorinated solvents, although findings were based on small numbers, and doseresponse gradients were not observed. At present, there is no consistent evidence from either the toxicological or epidemiologic perspective that any specific solvent or class of solvents is a cause of PD. Future toxicological research that addresses mechanisms of nigral damage from TCE and its metabolites, with exposure routes and doses relevant to human exposures, is recommended. Improvements in epidemiologic research, especially with regard to quantitative characterization of long-term exposures to specific solvents, are needed to advance scientific knowledge on this topic. -- Highlights: ? The potential for organic solvents to cause Parkinson's disease has been reviewed. ? Twins study suggests etiologic relations with chlorinated solvents and Parkinson's. ? Animal studies with TCE showed potential to cause damage to dopaminergic neurons. ? Need to determine if effects in animals are relevant to human exposure levels.

Lock, Edward A., E-mail: e.lock@ljmu.ac.uk [Liverpool John Moores University, School of Pharmacy and Biomolecular Sciences, Byrom Street, Liverpool (United Kingdom); Zhang, Jing [University of Washington, Department of Pathology, School of Medicine, Seattle, WA (United States)] [University of Washington, Department of Pathology, School of Medicine, Seattle, WA (United States); Checkoway, Harvey [University of Washington, Department of Environmental and Occupational Health Sciences, Seattle, WA (United States)] [University of Washington, Department of Environmental and Occupational Health Sciences, Seattle, WA (United States)

2013-02-01

128

Weakness  

MedlinePLUS

... by a slipped disk in the spine) Stroke MUSCLE DISEASES Becker muscular dystrophy Dermatomyositis Muscular dystrophy (Duchenne) Myotonic dystrophy POISONING Botulism Poisoning ( insecticides , nerve gas) ...

129

Solvent Influences on the Molecular Aggregation of Magnesium Aryloxides  

SciTech Connect

Magnesium aryloxides were prepared in a variety of solvents through the reaction of dibutyl magnesium with sterically varied aryl alcohols: 2,6-dimethylphenol (H-DMP), 2,6-diisopropylphenol (H-DIP), and 2,4,6-trichlorophenol (H-TCP). Upon using a sufficiently strong Lewis-basic solvent, the monomeric species Mg(DMP){sub 2}(py){sub 3} (1, py = pyridine), Mg(DIP){sub 2}(THF){sub 3}, (2a, THF = tetrahydrofuran) Mg(TCP){sub 2}(THF){sub 3} (3) were isolated. Each of these complexes possesses a five-coordinate magnesium that adopts a trigonal bipyramidal geometry. In the absence of a Lewis base, the reaction with H-DIP yields a soluble trinuclear complex, [Mg(DIP){sub 2}]{sub 3} (2b). The Mg metal centers in 2b adopt a linear arrangement with a four-coordinate central metal while the outer metal centers are reduced to just three-coordinate. Solution spectroscopic methods suggest that while 2b remains intact, the monomeric species (1, 2a, and 3) are involved in equilibria, which facilitate intermolecular ligand transfer.

ZECHMANN,CECILIA A.; BOYLE,TIMOTHY J.; RODRIGUEZ,MARK A.; KEMP,RICHARD A.

2000-07-14

130

Understanding social motor coordination.  

PubMed

Recently there has been much interest in social coordination of motor movements, or as it is referred to by some researchers, joint action. This paper reviews the cognitive perspective's common coding/mirror neuron theory of joint action, describes some of its limitations and then presents the behavioral dynamics perspective as an alternative way of understanding social motor coordination. In particular, behavioral dynamics' ability to explain the temporal coordination of interacting individuals is detailed. Two experiments are then described that demonstrate how dynamical processes of synchronization are apparent in the coordination underlying everyday joint actions such as martial art exercises, hand-clapping games, and conversations. The import of this evidence is that emergent dynamic patterns such as synchronization are the behavioral order that any neural substrate supporting joint action (e.g., mirror systems) would have to sustain. PMID:20817320

Schmidt, R C; Fitzpatrick, Paula; Caron, Robert; Mergeche, Joanna

2011-10-01

131

Corrected geomagnetic pole coordinates  

Microsoft Academic Search

A new method for the accurate calculation of the corrected geomagnetic pole coordinates is developed. The results are compared with those obtained by previous methods, and maximum divergence was found to be approximately 1-deg.

Iu. L. Sverdlov; T. N. Khorkova

1982-01-01

132

Biorepository Coordinating Committee (BCC)  

Cancer.gov

Based on the findings of an NCI analysis of NCI-supported biorepositories, the National Cancer Advisory Board (NCAB) approved in November 2004 the formation of a trans-NCI committee, called the NCI Biorepository Coordinating Committee (BCC).

133

Kairoscope : coordinating time socially  

E-print Network

If everyone says time is relative, why is it still so rigidly defined? There have been many attempts to address the issue of coordinating schedules, but each of these attempts runs into an issue of rigidity: in order to ...

Martin, Reed Eric

2010-01-01

134

Vocational Education Curriculum Coordination.  

ERIC Educational Resources Information Center

Discusses the history, current structure, publications and communications strategies, information services for educators, and national information search procedures of the National Network for Curriculum Coordination in Vocational and Technical Education (NNCCVTE). (JL)

Bjorner, Susan

1982-01-01

135

Solvent effects on fluorescence properties of protochlorophyll and its derivatives with various porphyrin side chains.  

PubMed

Fluorescence spectra and fluorescence lifetimes of protochlorophyll (Pchl) were measured in organic solvents having different physical and chemical properties and were analyzed taking into account the nonspecific (dependent on bulk solvent parameters), and specific (e.g. H bonds, Mg coordination) solvent-solute interactions. The energy of the fluorescence emission band decreased, while the Stokes shift increased for increasing solvent orientation polarizability, which is a function of both the dielectric constant (epsilon) and the refractive index (n). The extent of the dependence of the Stokes shift on solvent orientation polarizability was higher in protic (i.e. those able to form hydrogen-binding) than in aprotic solvents. High value of the Stokes shift was also observed in pyridine and methanol, i.e. in solvents hexacoordinating the central Mg atom. The fluorescence decay of Pchl was monoexponential in all of the investigated solvents. The fluorescence lifetime decreased for increasing solvent orientation polarizability from 5.5 +/- 0.1 ns in 1,4-dioxane to 3.3 +/- 0.1 ns in methanol. Longer lifetime values were observed in the case of aprotic solvents than in protic solvents. The hexacoordination of Mg had no effect on the fluorescence lifetime. The present data are discussed with respect to results found for protochlorophyllide (Pchlide) (My?liwa-Kurdziel et al. in Photochem Photobiol 79:62-67, 2004), and they indicate that the presence of phytol chain in the porphyrin ring influences the spectral properties of the whole chromophore. This is the first complex analysis comparing the fluorescence emission and fluorescence lifetimes of purified Pchl and Pchlide. PMID:18340441

My?liwa-Kurdziel, Beata; Solymosi, Katalin; Kruk, Jerzy; Bddi, Bla; Strza?ka, Kazimierz

2008-09-01

136

Pathwise coordinate optimization  

Microsoft Academic Search

We consider ``one-at-a-time'' coordinate-wise descent algorithms for a class of convex optimization problems. An algorithm of this kind has been proposed for the $L_1$-penalized regression (lasso) in the literature, but it seems to have been largely ignored. Indeed, it seems that coordinate-wise algorithms are not often used in convex optimization. We show that this algorithm is very competitive with the

Jerome Friedman; Trevor Hastie; Holger Hfling; Robert Tibshirani

2007-01-01

137

Dynamics of Interpersonal Coordination  

Microsoft Academic Search

Everyday human actions often occur in a social context. Past psychological research has found that the motor behavior of socially\\u000a situated individuals tends to be coordinated. Our research performed over the last 20 years has sought to understand how the\\u000a mutuality, accommodation, and synchrony found in everyday interactional coordination can be understood using a dynamical theory\\u000a of behavioral order, namely

Richard C. Schmidt; Michael J. Richardson

138

Weak-Chaos Ratchet Accelerator  

E-print Network

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.

Itzhack Dana; Vladislav B. Roitberg

2012-05-28

139

Cosmology and the weak interaction  

NASA Technical Reports Server (NTRS)

The weak interaction plays a critical role in modern Big Bang cosmology. Two of its most publicized comological connections are emphasized: big bang nucleosynthesis and dark matter. The first of these is connected to the cosmological prediction of neutrine flavors, N(sub nu) is approximately 3 which in now being confirmed. The second is interrelated to the whole problem of galacty and structure formation in the universe. The role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure is demonstrated.

Schramm, David N.

1989-01-01

140

NATURAL ATTENUATION OF CHLORINATED SOLVENTS  

EPA Science Inventory

The protocol will simply describe in detail, with references and illustrations, the approach currently used by staff of the SPRD to evaluate natural attenuation of chlorinated solvents in ground water. Staff of SPRD, and staff of the Air Force Center for environmental excellence...

141

Replacement solvents for use in chemical synthesis  

DOEpatents

Replacement solvents for use in chemical synthesis include polymer-immobilized solvents having a flexible polymer backbone and a plurality of pendant groups attached onto the polymer backbone, the pendant groups comprising a flexible linking unit bound to the polymer backbone and to a terminal solvating moiety. The polymer-immobilized solvent may be dissolved in a benign medium. Replacement solvents for chemical reactions for which tetrahydrofuran or diethyl may be a solvent include substituted tetrahydrofurfuryl ethers and substituted tetrahydro-3-furan ethers. The replacement solvents may be readily recovered from the reaction train using conventional methods.

Molnar, Linda K. (Philadelphia, PA); Hatton, T. Alan (Sudbury, MA); Buchwald, Stephen L. (Newton, MA)

2001-05-15

142

Role of solvent dynamics in ultrafast photoinduced proton-coupled electron transfer reactions in solution.  

PubMed

A theoretical formulation for modeling photoinduced nonequilibrium proton-coupled electron transfer (PCET) reactions in solution is presented. In this formulation, the PCET system is described by donor and acceptor electron-proton vibronic free energy surfaces that depend on a single collective solvent coordinate. Dielectric continuum theory is used to obtain a generalized Langevin equation of motion for this collective solvent coordinate. The terms in this equation depend on the solvent properties, such as the dielectric constants, relaxation time, and molecular moment of inertia, as well as the solute properties characterizing the vibronic surfaces. The ultrafast dynamics following photoexcitation is simulated using a surface hopping method in conjunction with the Langevin equation of motion. This methodology is used to examine a series of model photoinduced PCET systems, where the initial nonequilibrium state is prepared by vertical photoexcitation from the ground electronic state to the donor electronic state. Analysis of the dynamical trajectories provides insight into the interplay between the solvent dynamics and the electron-proton transfer for these types of processes. In addition, these model studies illustrate how the coupling between the electron-proton transfer and the solvent dynamics can be tuned by altering the solute and solvent properties. PMID:20809583

Hazra, Anirban; Soudackov, Alexander V; Hammes-Schiffer, Sharon

2010-09-30

143

Interactions between solvent molecules and the reduced or unreduced forms of silico-molybdic acid studied by ESR and NMR spectroscopies and molecular modelling  

Microsoft Academic Search

H4[SiMo12O40] can take part in redox reactions as well as electrophilic transformations. The reduction of Mo(VI) to Mo(V) in various solvents was followed by ESR spectroscopy. The spectra show significant rhombic splitting, which can be correlated with the dielectric constants of the solvents. Coordination of solvents distorts the symmetry of MoO6 octahedra. Based on the degree of splitting it is

Bla Trk; Marianna Trk; Mria Rzsa-Tarjni; Istvn Plink; Lszl I Horvth; Imre Kiricsi; rpd Molnr

2000-01-01

144

Weak lensing and dark energy  

NASA Astrophysics Data System (ADS)

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. With reasonable prior information on other cosmological parameters, we find that a survey covering 1000 sq. deg. down to a limiting magnitude of R = 27 can impose constraints comparable to those expected from upcoming type Ia supernova and number-count surveys. This result, however, is contingent on the control of both observational and theoretical systematics. Concentrating on the latter, we find that the nonlinear power spectrum of matter perturbations and the redshift distribution of source galaxies both need to be determined accurately in order for weak lensing to achieve its full potential. Finally, we discuss the sensitivity of the three-point statistics to dark energy.

Huterer, Dragan

145

Hierarchic Superposition With Weak Abstraction  

E-print Network

Hierarchic Superposition With Weak Abstraction Peter Baumgartner Uwe Waldmann MPI­I­2013­RG1­002 June 2013 #12;Authors' Addresses Peter Baumgartner NICTA and Australian National University Tower A, 7 London Circuit Canberra ACT 2601, Australia Uwe Waldmann Max-Planck-Institut f¨ur Informatik Campus E 1 4

Waldmann, Uwe

146

The transformation from Eulerian to Lagrangian coordinates for solutions with discontinuities  

Microsoft Academic Search

We demonstrate the equivalence of Eulerian and Lagrangian coordinates for weak, discontinuous solutions in one space dimension.\\u000a This transformation also induces a one to one correspondence between the convex extensions, or \\

David H. Wagner

147

Competing weak localization and weak antilocalization in ultrathin topological insulators.  

PubMed

We demonstrate evidence of a surface gap opening in topological insulator (TI) thin films of (Bi(0.57)Sb(0.43))(2)Te(3) below six quintuple layers through transport and scanning tunneling spectroscopy measurements. By effective tuning the Fermi level via gate-voltage control, we unveil a striking competition between weak localization and weak antilocalization at low magnetic fields in nonmagnetic ultrathin films, possibly owing to the change of the net Berry phase. Furthermore, when the Fermi level is swept into the surface gap of ultrathin samples, the overall unitary behaviors are revealed at higher magnetic fields, which are in contrast to the pure WAL signals obtained in thicker films. 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. PMID:23198980

Lang, Murong; He, Liang; Kou, Xufeng; Upadhyaya, Pramey; Fan, Yabin; Chu, Hao; Jiang, Ying; Bardarson, Jens H; Jiang, Wanjun; Choi, Eun Sang; Wang, Yong; Yeh, Nai-Chang; Moore, Joel; Wang, Kang L

2013-01-01

148

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

149

One-nucleon-induced nonmesonic hypernuclear decay in laboratory coordinates  

SciTech Connect

We present a formalism for the computation of one-nucleon-induced nonmesonic weak hypernuclear decay rates in laboratory coordinates, within an independent-particle shell model framework, with a view to its generalization to the case of two-nucleon-induced transitions.

Galeao, A. P. [Instituto de Fisica Teorica, UNESP, 01140-070 Sao Paulo, SP (Brazil); Barbero, C. [Facultad de Ciencias Exactas, UNLP, 1900 La Plata (Argentina) and Instituto de Fisica La Plata, CONICET, 1900 La Plata (Argentina); De Conti, C. [Campus Experimental de Itapeva, UNESP, 18409-010 Itapeva, SP (Brazil); Krmpotic, F. [Facultad de Ciencias Astronomicas y Geofisicas, UNLP, 1900 La Plata (Argentina) and Instituto de Fisica La Plata, CONICET, 1900 La Plata (Argentina)

2013-05-06

150

Dipolar correlations in structured solvents under nanoconfinement  

E-print Network

We study electrostatic correlations in structured solvents confined to nanoscale systems. We derive variational equations of Netz-Orland type for a model liquid composed of finite size dipoles. These equations are solved for both dilute solvents and solvents at physiological concentrations in a slit nanopore geometry. Correlation effects are of major importance for the dielectric reduction and anisotropy of the solvent resulting from dipole image interactions and also lead to a reduction of van der Waals attractions between low dielectric bodies. Finally, by comparison with other recently developed self-consistent theories and experiments, we scrutinize the effect of solvent-membrane interactions on the differential capacitance of the charged liquid in contact with low dielectric substrates. The interfacial solvent depletion driven by solvent-image interactions plays the major role in the observed low values of the experimental capacitance data, while non-locality associated with the extended charge structure of solvent molecules only brings a minor contribution.

Sahin Buyukdagli; Ralf Blossey

2014-03-18

151

Post-selected weak measurement beyond the weak value  

E-print Network

Closed expressions are derived for the quantum measurement statistics of pre-and postselected gaussian particle beams. The weakness of the pre-selection step is shown to compete with the non-orthogonality of post-selection in a transparent way. The approach is shown to be useful in analyzing post-selection-based signal amplification, allowing measurements to be extended far beyond the range of validity of the well-known Aharonov-Albert-Vaidman limit.

Tamas Geszti

2009-09-11

152

Coordinate Covalent C f B Bonding in Phenylborates and Latent Formation of Phenyl Anions from Phenylboronic Acid  

E-print Network

Coordinate Covalent C f B Bonding in Phenylborates and Latent Formation of Phenyl Anions from. It is shown that Ph-B bonding in [Ph-B(OH)2Nu]- is coordinate covalent and rather weak ( ). The coordinate covalent bonding is large enough to inhibit unimolecular dissociation and bimolecular nucleophile

Glaser, Rainer

153

Solvent refining of Kuwaiti heavy diesel oil  

SciTech Connect

Results of studies to determine the optimum operating conditions for the solvent refining of Kuwaiti heavy diesel oil (HDO) to find the most suitable solvent for the production of lube oil base stocks from HDO are reported. The solvents studied were furfural, ..beta..-methoxypropionitrile (..beta..-MPN) and N-methylpyrrolidone (NMP). NMP was found to have the highest capacity as a solvent. (BLM)

Ijam, M.J.; Fahim, M.A.; Abu-Elgheit, M.

1981-08-01

154

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

155

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

156

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

157

Optimization of a Solvent Extraction Desalination Plant  

E-print Network

. Solvent Extraction Desalination Plant Page 106 3 ~ Solubility of Methyldiethylamine. Selectivity of Methyldiethyl amine Solubility of Methyldiethylamine and Salt Vapor Liquid Equilibria . . . . . . . . ~ Heat of Solution of Methyldiethylamine... showed that secondary and tertiary amines were the best suited solvents available. The preliminary cost estimate was based on incomplete data with tertiary octylamine chosen 1' or the solvent (4). The resulting operating cost and total plant...

Beighle, Phillip Lew

2012-06-07

158

Harmonic coordinates on fractals with finitely ramified cell structure  

E-print Network

We define sets with finitely ramified cell structure, which are generalizations of p.c.f. self-similar sets introduced by Kigami and of fractafolds introduced by Strichartz. In general, we do not assume even local self-similarity, and allow countably many cells connected at each junction point. We prove that if Kigami's resistance form satisfies certain assumptions, then there exists a weak Riemannian metric such that the energy can be expressed as the integral of the norm squared of a weak gradient with respect to an energy measure. Furthermore, we prove that if such a set can be homeomorphically represented in harmonic coordinates, then for smooth functions the weak gradient can be replaced by the usual gradient. We also prove a simple formula for the energy measure Laplacian in harmonic coordinates.

Alexander Teplyaev

2005-06-14

159

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

160

A Weakly Intuitionistic Quantum Logic  

E-print Network

In this paper we motivate and study the possibility of an intuitionistic quantum logic. An explicit investigation of the application of the theory of Bruns and Lakser on distributive hulls on traditional quantum logic (as suggested in [Coe]) leads us to a small modification of this scheme. In this way we obtain a weak Heyting algebra (cf. [CJ]) for describing the language of quantum mechanics.

Ronnie Hermens

2010-09-13

161

Weak measurement of arrival time  

SciTech Connect

The arrival time probability distribution is defined by analogy with classical mechanics. The difficulty of requiring knowledge of the values of noncommuting operators is circumvented using the concept of weak measurements. The proposed procedure is suitable for free particles as well as for those subjected to an external potential. It is shown that such an approach imposes an inherent limitation on the accuracy of the arrival time determination.

Ruseckas, J.; Kaulakys, B. [Institute of Theoretical Physics and Astronomy, A. Gostauto 12, 2600 Vilnius (Lithuania)

2002-11-01

162

Quark mixing in weak interactions  

Microsoft Academic Search

The status of the quark mixing in weak interaction is reviewed. The 33 quark mixing matrix for the three left-handed doublet model is analyzed using various experimental information involving strange, charmed, and b-flavored particles. Its interplay with nonleptonic decays, implication on neutral particle-antiparticle mixing and CP violation in heavy quark systems, and the possible origin of the quark mixing from

Ling-Lie Chau

1983-01-01

163

The Weak Scale from BBN  

E-print Network

The measured values of the weak scale, $v$, and the first generation masses, $m_{u,d,e}$, are simultaneously explained in the multiverse, with all these parameters scanning independently. At the same time, several remarkable coincidences are understood. Small variations in these parameters away from their measured values lead to the instability of hydrogen, the instability of heavy nuclei, and either a hydrogen or a helium dominated universe from Big Bang Nucleosynthesis. In the 4d parameter space of $(m_u,m_d,m_e,v)$, catastrophic boundaries are reached by separately increasing each parameter above its measured value by a factor of $(1.4,1.3,2.5,\\sim5)$, respectively. The fine-tuning problem of the weak scale in the Standard Model is solved: as $v$ is increased beyond the observed value, it is impossible to maintain a significant cosmological hydrogen abundance for any values of $m_{u,d,e}$ that yield both hydrogen and heavy nuclei stability. For very large values of $v$ a new regime is entered where weak in...

Hall, Lawrence J; Ruderman, Joshua T

2014-01-01

164

Solute-solvent and solvent-solvent interactions in the preferential solvation of 4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide in 24 binary solvent mixtures  

NASA Astrophysics Data System (ADS)

The molar transition energy ( ET) polarity values for the dye 4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide were collected in binary mixtures comprising a hydrogen-bond accepting (HBA) solvent (acetone, acetonitrile, dimethyl sulfoxide (DMSO), and N, N-dimethylformamide (DMF)) and a hydrogen-bond donating (HBD) solvent (water, methanol, ethanol, propan-2-ol, and butan-1-ol). Data referring to mixtures of water with alcohols were also analyzed. These data were used in the study of the preferential solvation of the probe, in terms of both solute-solvent and solvent-solvent interactions. These latter interactions are of importance in explaining the synergistic behavior observed for many mixed solvent systems. All data were successfully fitted to a model based on solvent-exchange equilibria. The ET values of the dye dissolved in the solvents show that the position of the solvatochromic absorption band of the dye is dependent on the medium polarity. The solvation of the dye in HBA solvents occurs with a very important contribution from ion-dipole interactions. In HBD solvents, the hydrogen bonding between the dimethylamino group in the dye and the OH group in the solvent plays an important role in the solvation of the dye. The interaction of the hydroxylic solvent with the other component in the mixture can lead to the formation of hydrogen-bonded complexes, which solvate the dye using a lower polar moiety, i.e. alkyl groups in the solvents. The dye has a hydrophobic nature and a dimethylamino group with a minor capability for hydrogen bonding with the medium in comparison with the phenolate group present in Reichardt's pyridiniophenolate. Thus, the probe is able to detect solvent-solvent interactions, which are implicit to the observed synergistic behavior.

Bevilaqua, Tharly; Gonalves, Thaini F.; Venturini, Cristina de G.; Machado, Vanderlei G.

2006-11-01

165

Mackenzie Broughton Unit Coordinator  

E-print Network

.broughton@ttu.edu. Employer Resources RECRUITING ENGINEERING STUDENTS As an engineering company recruiting at Texas Tech, weMackenzie Broughton Unit Coordinator Career Services mackenzie.broughton@ttu.edu Employer Resources anywhere, the Whitacre College of Engineering is committed to making your recruitment experiences on our

Gelfond, Michael

166

Coordination and Integration  

Microsoft Academic Search

A strong coordination (i. e. the configuration of data flows and the division of planning tasks to modules) of APS modules is a prerequisite to achieve consistent plans for the different planning levels and for each entity of the supply chain. The same data should be used for each de-centralized planning task and decision. APS can be seen as add-ons

Jens Rohde

167

Coordinated Program in Dietetics  

E-print Network

_tuiton_fee.html umdnJ FinAnciAl Aid Phone: 973-972-4376 Web: www.umdnj.edu/studentfinancialaid imporTAnT conTAcT inFormATion UMDNJ-BSHS Coordinated Program in Dietetics 2nd Bachelor's Degree #12;Students who

Cheng, Mei-Fang

168

Brent Warner Coordinator  

E-print Network

food system?Our food system? #12;"We put fast food on every corner, we put junk food in our schools, weBrent Warner Coordinator Canadian Agritourism Working Group (CATWG) Local FoodLocal Food ! #12;· less and less money spent on food as a percentage of income except in 2009 up 4.4% You have

Peak, Derek

169

Communication Gestion et coordination  

E-print Network

Communication Gestion et coordination de patrouilles environnementales Développement de stratégies et d'outils de communication en développement durable Communication des politiques, programmes et travail interdisciplinaire, la communication et l'esprit critique. Au final, les diplômés pourront exercer

Spino, Claude

170

Biochemistry 448 Course Coordinator  

E-print Network

Biochemistry 448 Course Coordinator Dr Scott Covey scott.covey@ubc.ca 604-822-1949 Course Description This is an independent biochemistry driven research project performed under the supervision independent research and lab work. Although biochemistry honours students have priority majors student can

Strynadka, Natalie

171

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

172

Origins of Coordinate Searching.  

ERIC Educational Resources Information Center

Reviews the origins of post-coordinate searching and emphasizes that the focal point should be on the searcher, not on the item being indexed. Highlights include the history of the term information retrieval; edge notched punch cards; the "peek-a-boo" system; the Uniterm system; and using computers to search for information. (LRW)

Kilgour, Frederick G.

1997-01-01

173

Measurement of solvent accessibility at protein-protein interfaces.  

PubMed

Methods are presented for monitoring solvent accessibility of protein-ligand and protein-protein interfaces. The kinetics of solvent accessibility at the protein-protein interface is monitored by amide hydrogen/deuterium (H/2H) exchange detected by matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). A straightforward theoretical analysis is presented for determining the concentration of a weakly binding ligand that is required for achieving a situation in which the receptor is essentially 100% bound, and this is verified by control experiments. We show that when the receptor is essentially 100% bound it is possible to distinguish amide exchange as a result of solvent accessibility at the interface from amide exchange caused by complex dissociation. Methods are also presented for the measurement of tightly bound complexes of large interactions such as antibody-antigen complexes. Quantitation of the number of amides sequestered at the interface can be related to the number of H2O molecules excluded from the interface. PMID:15939994

Mandell, Jeffrey G; Baerga-Ortiz, Abel; Falick, Arnold M; Komives, Elizabeth A

2005-01-01

174

Solvent dependence of low frequency vibrational modes: an ultrafast optical Kerr effect study of diphenylmethane  

NASA Astrophysics Data System (ADS)

The ultrafast dynamics of diphenylmethane and its solutions have been measured. A mode at 80 cm -1 has been identified as being of intramolecular origin. The frequency of this mode is observed to be a strong function of solvent, shifting to lower frequency in more weakly interacting solvents. Such a shift is very similar to that observed for molecular librations in solution. It is concluded that the potential energy curve associated with a low frequency mode depends not only on intramolecular forces, but also on its interaction with the environment.

Hunt, Neil T.; Meech, Stephen R.

2003-08-01

175

Weak Interactions in Atoms Nuclear Anapole Moment Weak Coupling Constants Nuclear Anapole Moment  

E-print Network

Weak Interactions in Atoms Nuclear Anapole Moment Weak Coupling Constants Nuclear Anapole Moment;Weak Interactions in Atoms Nuclear Anapole Moment Weak Coupling Constants Plan of the talk Weak Interactions in Atoms Charged and Neutral Currents. Effective P-odd Hamiltonian Nuclear Anapole Moment

Pines, Alexander

176

Reversible phase transformation and mechanochromic luminescence of Zn(II)-dipyridylamide-based coordination frameworks.  

PubMed

A 1D double-zigzag framework, {[Zn(paps)(2)(H(2)O)(2)](ClO(4))(2)}(n) (1; paps = N,N'-bis(pyridylcarbonyl)-4,4'-diaminodiphenyl thioether), was synthesized by the reaction of Zn(ClO(4))(2) with paps. However, a similar reaction, except that dry solvents were used, led to the formation of a novel 2D polyrotaxane framework, [Zn(paps)(2)(ClO(4))(2)](n) (2). This difference relies on the fact that water coordinates to the Zn(II) ion in 1, but ClO(4)(-) ion coordination is found in 2. Notably, the structures can be interconverted by heating and grinding in the presence of moisture, and such a structural transformation can also be proven experimentally by powder and single-crystal X-ray diffraction studies. The related N,N'-bis- (pyridylcarbonyl)-4,4'-diaminodiphenyl ether (papo) and N,N'-(methylenedi-para-phenylene)bispyridine-4-carboxamide (papc) ligands were reacted with Zn(II) ions as well. When a similar reaction was performed with dry solvents, except that papo was used instead of paps, the product mixture contained mononuclear [Zn(papo)(CH(3)OH)(4)](ClO(4))(2) (5) and the polyrotaxane [Zn(papo)(2)(ClO(4))(2)](n) (4). From the powder XRD data, grinding this mixture in the presence of moisture resulted in total conversion to the pure double-zigzag {[Zn(papo)(2)(H(2)O)(2)](ClO(4))(2)}(n) (3) immediately. Upon heating 3, the polyrotaxane framework of 4 was recovered. The double-zigzag {[Zn(papc)(2)(H(2)O)(2)](ClO(4))(2)}(n) (6) and polyrotaxane [Zn(papc)(2)(ClO(4))(2)](n) (7) were synthesized in a similar reaction. Although upon heating the double-zigzag 6 undergoes structural transformation to give the polyrotaxane 7, grinding solid 7 in the presence of moisture does not lead to the formation of 6. Significantly, the bright emissions for double-zigzag frameworks of 1 and 3 and weak ones for polyrotaxane frameworks of 2 and 4 also show interesting mechanochromic luminescence. PMID:22407863

Tzeng, Biing-Chiau; Chang, Tsung-Yi; Wei, Sheng-Luen; Sheu, Hwo-Shuenn

2012-04-16

177

Tagged-weak {pi} method  

SciTech Connect

A new 'tagged-weak {pi} method' is proposed for determination of electromagnetic transition probabilities B(E2) and B(M1) of the hypernuclear states with lifetimes of {approx}10{sup -10} s. With this method, we are planning to measure B(E2) and B(M1) for light hypernuclei at JLab. The results of Monte Carlo simulations for the case of E2(5/2{sup +}, 3/2{sup +} {yields} 1/2{sup +}) transitions in {sub {Lambda}}{sup 7}He hypernuclei are presented.

Margaryan, A., E-mail: mat@yerphi.am [Yerevan Physics Institute (Armenia); Hashimoto, O. [Tohoku University, Department of Physics (Japan); Kakoyan, V.; Knyazyan, S. [Yerevan Physics Institute (Armenia); Tang, L. [Hampton University, Department of Physics (United States)

2011-02-15

178

Electromagnetic weak turbulence theory revisited  

SciTech Connect

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. [IPST, University of Maryland, College Park, Maryland 20742 (United States); Ziebell, L. F. [Instituto de Fisica, UFRGS, Porto Alegre, RS (Brazil); Gaelzer, R.; Pavan, J. [Instituto de Fisica e Matematica, UFPel, Pelotas, RS (Brazil)

2012-10-15

179

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

180

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

181

Shared Activity Coordination  

NASA Technical Reports Server (NTRS)

Interacting agents that interleave planning and execution must reach consensus on their commitments to each other. In domains where agents have varying degrees of interaction and different constraints on communication and computation, agents will require different coordination protocols in order to efficiently reach consensus in real time. We briefly describe a largely unexplored class of real-time, distributed planning problems (inspired by interacting spacecraft missions), new challenges they pose, and a general approach to solving the problems. These problems involve self-interested agents that have infrequent communication but collaborate on joint activities. We describe a Shared Activity Coordination (SHAC) framework that provides a decentralized algorithm for negotiating the scheduling of shared activities in a dynamic environment, a soft, real-time approach to reaching consensus during execution with limited communication, and a foundation for customizing protocols for negotiating planner interactions. We apply SHAC to a realistic simulation of interacting Mars missions and illustrate the simplicity of protocol development.

Clement, Bradley J.; Barrett, Anthony C.

2003-01-01

182

Plant Breeding Coordinating Committee  

NSDL National Science Digital Library

To view additional success stories click on the link in the left menu Please click here to report your plant breeding success stories.  Click on TCAP logo to see the Economic impact of USDA-NIFA small grains CAPsThe Plant Breeding Coordinating Committee (SCC 080) is the USDA-sponsored advisory group of representatives from land grant universities.  The Plant Breeding Coordinating Committee represents national plant breeding with a focus on education in the broader sense, including providing information to the public and administrators, and encouraging the development of formal educational opportunities, continuing education, and lifelong learning. Mission: To provide a forum for leadership on issues and opportunities of strategic importance to national core competency in plant breeding research and education Membership: The PBCC members will consist of the representatives of the SCC-080 committee and others by request. 

183

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

184

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

185

Quantum Weak Measurements and Cosmology  

E-print Network

The indeterminism of quantum mechanics generally permits the independent specification of both an initial and a final condition on the state. Quantum pre-and-post-selection of states opens up a new, experimentally testable, sector of quantum mechanics, when combined with statistical averages of identical weak measurements. In this paper I apply the theory of weak quantum measurements combined with pre-and-post-selection to cosmology. Here, pre-selection means specifying the wave function of the universe or, in a popular semi-classical approximation, the initial quantum state of a subset of quantum fields propagating in a classical back-ground spacetime. The novel feature is post-selection: the additional specification of a condition on the quantum state in the far future. I discuss "natural" final conditions, and show how they may lead to potentially large and observable effects at the present cosmological epoch. I also discuss how pre-and-post-selected quantum contrast to the expectation value of the stress-energy-momentum tensor, resolving a vigorous debate from the 1970's. The paper thus provides a framework for computing large-scale cosmological effects arising from this new sector of quantum mechanics. A simple experimental test is proposed.

Paul Davies

2013-09-03

186

Weakly Circadian Cells Improve Resynchrony  

PubMed Central

The mammalian suprachiasmatic nuclei (SCN) contain thousands of neurons capable of generating near 24-h rhythms. When isolated from their network, SCN neurons exhibit a range of oscillatory phenotypes: sustained or damping oscillations, or arrhythmic patterns. The implications of this variability are unknown. Experimentally, we found that cells within SCN explants recover from pharmacologically-induced desynchrony by re-establishing rhythmicity and synchrony in waves, independent of their intrinsic circadian period We therefore hypothesized that a cell's location within the network may also critically determine its resynchronization. To test this, we employed a deterministic, mechanistic model of circadian oscillators where we could independently control cell-intrinsic and network-connectivity parameters. We found that small changes in key parameters produced the full range of oscillatory phenotypes seen in biological cells, including similar distributions of period, amplitude and ability to cycle. The model also predicted that weaker oscillators could adjust their phase more readily than stronger oscillators. Using these model cells we explored potential biological consequences of their number and placement within the network. We found that the population synchronized to a higher degree when weak oscillators were at highly connected nodes within the network. A mathematically independent phase-amplitude model reproduced these findings. Thus, small differences in cell-intrinsic parameters contribute to large changes in the oscillatory ability of a cell, but the location of weak oscillators within the network also critically shapes the degree of synchronization for the population. PMID:23209395

Thoroughman, Kurt A.; Doyle, Francis J.; Herzog, Erik D.

2012-01-01

187

Quantum Weak Measurements and Cosmology  

NASA Astrophysics Data System (ADS)

The indeterminism of quantum mechanics generally permits the independent specification of both an initial and a final condition on the state. Quantum pre- and post-selection of states opens up a new, experimentally testable, sector of quantum mechanics, when combined with statistical averages of identical weak measurements. In this paper I apply the theory of weak quantum measurements combined with pre- and post-selection to cosmology. Here, pre-selection means specifying the wave function of the universe or, in a popular semi-classical approximation, the initial quantum state of a subset of quantum fields propagating in a classical background spacetime. The novel feature is post-selection: the additional specification of a condition on the quantum state in the far future. I discuss "natural" final conditions, and show how they may lead to potentially large and observable effects at the present cosmological epoch. I also discuss how pre- and post-selected quantum fields couple to gravity via the DeWitt-Schwinger effective action prescription, in contrast to the expectation value of the stress-energy-momentum tensor, resolving a vigorous debate from the 1970s. The paper thus provides a framework for computing large-scale cosmological effects arising from this new sector of quantum mechanics. A simple experimental test is proposed. [Editors note: for a video of the talk given by Prof. Davies at the Aharonov-80 conference in 2012 at Chapman University, see http://quantum.chapman.edu/talk-13.

Davies, P. C. W.

188

Weak lensing and cosmological investigation  

NASA Astrophysics Data System (ADS)

In the last few years the scientific community has been dealing with the challenging issue of identifying the dark energy component. We regard weak gravitational lensing as a brand new, and extremely important, tool for cosmological investigation in this field. In fact, the features imprinted on the Cosmic Microwave Background radiation by the lensing from the intervening distribution of matter represent a pretty unbiased estimator, and can thus be used for putting constraints on different dark energy models. This is true in particular for the magnetic-type B-modes of CMB polarization, whose unlensed spectrum at large multipoles (l ~= 1000) is very small even in presence of an amount of gravitational waves as large as currently allowed by the experiments: therefore, on these scales the lensing phenomenon is the only responsible for the observed power, and this signal turns out to be a faithful tracer of the dark energy dynamics. We first recall the formal apparatus of the weak lensing in extended theories of gravity, introducing the physical observables suitable to cast the bridge between lensing and cosmology, and then evaluate the amplitude of the expected effect in the particular case of a Non-Minimally-Coupled model, featuring a quadratic coupling between quintessence and Ricci scalar.

Acquaviva, Viviana

2005-03-01

189

Local shear instabilities in weakly ionized, weakly magnetized disks  

NASA Technical Reports Server (NTRS)

We extend the analysis of axisymmetric magnetic shear instabilities from ideal magnetohydrodynamic (MHD) flows to weakly ionized plasmas with coupling between ions and neutrals caused by collisions, ionization, and recombination. As part of the analysis, we derive the single-fluid MHD dispersion relation without invoking the Boussinesq approximation. This work expands the range of applications of these instabilities from fully ionized accretion disks to molecular disks in galaxies and, with somewhat more uncertainty, to protostellar disks. Instability generally requires the angular velocity to decrease outward, the magnetic field strengths to be subthermal, and the ions and neutrals to be sufficiently well coupled. If ionization and recombination processes can be neglected on an orbital timescale, adequate coupling is achieved when the collision frequency of a given neutral with the ions exceeds the local epicyclic freqency. When ionization equilibrium is maintained on an orbital timescale, a new feature is present in the disk dynamics: in contrast to a single-fluid system, subthermal azimuthal fields can affect the axisymmetric stability of weakly ionized two-fluid systems. We discuss the underlying causes for this behavior. Azimuthal fields tend to be stabilizing under these circumstances, and good coupling between the neutrals and ions requires the collision frequency to exceed the epicyclic frequency by a potentially large secant factor related to the magnetic field geometry. When the instability is present, subthermal azimuthal fields may also reduce the growth rate unless the collision frequency is high, but this is important only if the field strengths are very subthermal and/or the azimuthal field is the dominant field component. We briefly discuss our results in the context of the Galactic center circumnuclear disk, and suggest that the shear instability might be present there, and be responsible for the observed turbulent motions.

Blaes, Omer M.; Balbus, Steven A.

1994-01-01

190

Dynamic self-assembly of coordination polymers in aqueous solution.  

PubMed

The construction of supramolecular polymers has been intensively pursued because the nanostructures formed through weak non-covalent interactions can be triggered by external stimuli leading to smart materials and sensors. Self-assemblies of coordination polymers consisting of metal ions and organic ligands in aqueous solution also provide particular contributions in this area. The main motivation for developing those coordination polymers originates from the value-added combination between metal ions and ligands. This review highlights the recent progress of the dynamic self-assembly of coordination polymers that result from the sophisticated molecular design, towards fabricating stimuli-responsive systems and bio-related materials. Dynamic structural changes and switchable physical properties triggered by various stimuli are summarized. Finally, the outlook for aqueous nanostructures originated from the dynamic self-assembly of coordination polymers is also presented. PMID:24955807

Li, Wen; Kim, Yongju; Li, Jingfang; Lee, Myongsoo

2014-08-01

191

Asphaltene aggregation in organic solvents.  

PubMed

Asphaltenic solids formed in the Rangely field in the course of a carbon dioxide flood and heptane insolubles in the oil from the same field were used in this study. Four different solvents were used to dissolve the asphaltenes. Near-infrared (NIR) spectroscopy was used to determine the onset of asphaltene precipitation by heptane titration. When the onset values were plotted versus asphaltene concentrations, distinct break points (called critical aggregation concentrations (CAC) in this paper) were observed. CACs for the field asphaltenes dissolved in toluene, trichloroethylene, tetrahydrofuran, and pyridine occurred at concentrations of 3.0, 3.7, 5.0, and 8.2 g/l, respectively. CACs are observed at similar concentrations as critical micelle concentrations (CMC) for the asphaltenes in the solvents employed and can be interpreted to be the points at which rates of asphaltene aggregations change. CMC values of asphaltenes determined from surface tension measurements (in pyridine and TCE) were slightly higher than the CAC values measured by NIR onset measurements. The CAC for heptane-insoluble asphaltenes in toluene was 3.1 g/l. Thermal gravimetric analysis (TGA) and elemental compositions of the two asphaltenes showed that the H/C ratio of the heptane-insoluble asphaltenes was higher and molecular weight (measured by vapor pressure osmometry) was lower. PMID:14757097

Oh, Kyeongseok; Ring, Terry A; Deo, Milind D

2004-03-01

192

7 CFR 51.894 - Weak.  

Code of Federal Regulations, 2010 CFR

...AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Grades of Table Grapes (European or Vinifera Type) 1 Definitions 51.894 Weak. Weak means that individual berries are somewhat...

2010-01-01

193

Lanthanide-organic complexes based on polyoxometalates: Solvent effect on the luminescence properties  

SciTech Connect

A series of lanthanide-organic complexes based on polyoxometalates (POMs) [Ln{sub 2}(DNBA){sub 4}(DMF){sub 8}][W{sub 6}O{sub 19}] (Ln=La(1), Ce(2), Sm(3), Eu(4), Gd(5); DNBA=3,5-dinitrobenzoate; DMF=N,N-dimethylformamide) has been synthesized. These complexes consist of [W{sub 6}O{sub 19}]{sup 2-} and dimeric [Ln{sub 2}(DNBA){sub 4}(DMF){sub 8}]{sup 2+} cations. The luminescence properties of 4 are measured in solid state and different solutions, respectively. Notably, the emission intensity increases gradually with the increase of solvent permittivity, and this solvent effect can be directly observed by electrospray mass spectrometry (ESI-MS). The analyses of ESI-MS show that the eight coordinated solvent DMF units of dimeric cation are active. They can move away from dimeric cations and exchange with solvent molecules. Although the POM anions escape from 3D supramolecular network, the dimeric state structure of [Ln{sub 2}(DNBA){sub 4}]{sup 2+} remains unchanged in solution. The conservation of red luminescence is attributed to the maintenance of the aggregated state structures of dimeric cations. - Graphical abstract: 3D POMs-based lanthanide-organic complexes performed the solvent effect on the luminescence property. The origin of such solvent effect can be understood and explained on the basis of the existence of coordinated active sites by the studies of ESI-MS. Highlights: Black-Right-Pointing-Pointer The solvent effect on the luminescence property of POMs-based lanthanide-organic complexes. Black-Right-Pointing-Pointer ESI-MS analyses illuminate the correlation between the structure and luminescence property. Black-Right-Pointing-Pointer The dimeric cations have eight active sites of solvent coordination. Black-Right-Pointing-Pointer The aggregated state structure of dimer cation remains unchanged in solution. Black-Right-Pointing-Pointer Luminescence associating with ESI-MS is a new method for investigating the interaction of complex and solvent.

Tang Qun [Key Laboratory of Polyoxometalate Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China); Liu Shuxia, E-mail: liusx@nenu.edu.cn [Key Laboratory of Polyoxometalate Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China); Liang Dadong; Ma Fengji; Ren Guojian; Wei Feng; Yang Yuan; Li Congcong [Key Laboratory of Polyoxometalate Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China)

2012-06-15

194

Solvent signal as an NMR concentration reference.  

PubMed

We propose that the NMR solvent signal be utilized as a universal concentration reference because most solvents can be observed by NMR and solvent concentrations can be readily calculated or determined independently. In particular, a highly protonated solvent such as water can serve as a primary concentration standard for its stability, availability, and ease of observation. The potential problems of radiation damping associated with a strong NMR signal can be alleviated by small pulse angle excitation. The solvent signal then can be detected by the NMR receiver with the same efficiency as a dilute analyte. We demonstrated that the analyte's proton concentration can be accurately determined from 4 microM to more than 100 M, referenced by solvent (water) protons of concentrations more than 10 M. The proposed method is robust and indifferent to probe tuning and does not require any additional concentration standard. PMID:19007190

Mo, Huaping; Raftery, Daniel

2008-12-15

195

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

196

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

197

The strength of weak ties in crime  

Microsoft Academic Search

The aim of this paper is to investigate whether weak ties play an important role in explaining criminal activities. We first develop a model where individuals learn about crime opportunities by interacting with other peers. These interactions can take the form of either strong or weak ties. We find that increasing the percentage of weak ties induces more transitions from

Eleonora Patacchini; Yves Zenou

2008-01-01

198

The Strength of Weak Ties in Crime  

Microsoft Academic Search

The aim of this paper is to investigate whether weak ties play an important role in explaining criminal activities. We first develop a model where individuals learn about crime opportunities by interacting with active criminals. These interactions can take the form of either strong or weak ties. We find that increasing the percentage of weak ties induces more transitions from

Eleonora Patacchini; Yves Zenou

2007-01-01

199

129A Lecture Notes Weak Interactions II  

E-print Network

129A Lecture Notes Weak Interactions II 1 Glashow­Weinberg­Salam Theory We have seen that the weak processes. This point strongly suggests that the weak interaction is caused by the similar mechanism, Sheldon Glashow in 1962, and later Steven Weinberg and Abdus Salam, tried to formulate the theory

Murayama, Hitoshi

200

Weak KAM for commuting Hamiltonians  

NASA Astrophysics Data System (ADS)

For two commuting Tonelli Hamiltonians, we recover the commutation of the Lax-Oleinik semi-groups, a result of Barles and Tourin (2001 Indiana Univ. Math. J. 50 1523-44), using a direct geometrical method (Stoke's theorem). We also obtain a 'generalization' of a theorem of Maderna (2002 Bull. Soc. Math. France 130 493-506). More precisely, we prove that if the phase space is the cotangent of a compact manifold then the weak KAM solutions (or viscosity solutions of the critical stationary Hamilton-Jacobi equation) for G and for H are the same. As a corollary we obtain the equality of the Aubry sets and of the Peierls barrier. This is also related to works of Sorrentino (2009 On the Integrability of Tonelli Hamiltonians Preprint) and Bernard (2007 Duke Math. J. 136 401-20).

Zavidovique, M.

2010-04-01

201

Work Coordination Engine  

NASA Technical Reports Server (NTRS)

The Work Coordination Engine (WCE) is a Java application integrated into the Service Management Database (SMDB), which coordinates the dispatching and monitoring of a work order system. WCE de-queues work orders from SMDB and orchestrates the dispatching of work to a registered set of software worker applications distributed over a set of local, or remote, heterogeneous computing systems. WCE monitors the execution of work orders once dispatched, and accepts the results of the work order by storing to the SMDB persistent store. The software leverages the use of a relational database, Java Messaging System (JMS), and Web Services using Simple Object Access Protocol (SOAP) technologies to implement an efficient work-order dispatching mechanism capable of coordinating the work of multiple computer servers on various platforms working concurrently on different, or similar, types of data or algorithmic processing. Existing (legacy) applications can be wrapped with a proxy object so that no changes to the application are needed to make them available for integration into the work order system as "workers." WCE automatically reschedules work orders that fail to be executed by one server to a different server if available. From initiation to completion, the system manages the execution state of work orders and workers via a well-defined set of events, states, and actions. It allows for configurable work-order execution timeouts by work-order type. This innovation eliminates a current processing bottleneck by providing a highly scalable, distributed work-order system used to quickly generate products needed by the Deep Space Network (DSN) to support space flight operations. WCE is driven by asynchronous messages delivered via JMS indicating the availability of new work or workers. It runs completely unattended in support of the lights-out operations concept in the DSN.

Zendejas, Silvino; Bui, Tung; Bui, Bach; Malhotra, Shantanu; Chen, Fannie; Kim, Rachel; Allen, Christopher; Luong, Ivy; Chang, George; Sadaqathulla, Syed

2009-01-01

202

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

203

Status of coal research: Solvent extraction  

SciTech Connect

The early history of Solvent extraction in coal research has been reviewed by Van Krevelen. From the beginning, solvent extraction has been used to isolate and characterize both soluble and insoluble coal fractions. The recent studies covered in this report fall into four broad areas: (1) Improvement in extraction yields or selectivity; (2) Correlation of solvent swelling and extraction behavior to structural models for the insoluble organic portion of coal; (3) Analyses of extracts to identify and perhaps quantify organic compounds in the raw coal, and (4) Use of solvent extraction to predict or influence coal behavior in some other process such as liquefaction. To cover this active area in a brief Preprint, references were chosen to illustrate both the current status of the field and cite related studies. The availability of the pristine Argonne Premium Coal Samples has led to a significant improvement in the reproducibility of solvent extraction as an analytical tool. In 1984, Triolo and Child cautioned that solvent extraction may be an inherently unreproducible process. Based on studies of how weathering affects solvent extraction, that was a fair statement at the time. With the improvements and standardization of solvent extraction practices developed since then, it is now possible to obtain reproducible and reliable information from the solvent extraction of coal.

Buchanan, D.H. [Eastern Illinois Univ., Charleston, IL (United States)

1994-12-31

204

Martian surface coordinates  

NASA Technical Reports Server (NTRS)

The resolution of the pictures from the Mariner 9 mission determines the distribution of the control points, as well as the gaps in the planet-wide control net. After discussing the photogrammetric equations and the computational method used to establish the planet-wide control net and the secondary net, the camera stations and the assumed physical properties of Mars are considered. Subsequent paragraphs contain a description of the control points, their measurements, and a discussion of how distortions are removed. Finally, results of the computations are given, with tables of coordinates for the control points.

Davies, M. E.; Arthur, D. W. G.

1973-01-01

205

Child labor and coordination failures  

Microsoft Academic Search

In this note, we show that a technology-based coordination failure may explain the emergence of laws restricting child labor. Child labor may arise because of the lack of a coordination mechanism between parental decisions to invest in the human capital of their children and firms' decisions to invest in skill-biased technologies. Legislative intervention in many cases helps coordinate expectations towards

Sylvain E. Dessy; Stphane Pallage

2001-01-01

206

Reducing Systematic Error in Weak Lensing Cluster Surveys  

NASA Astrophysics Data System (ADS)

Weak lensing provides an important route toward collecting samples of clusters of galaxies selected by mass. Subtle systematic errors in image reduction can compromise the power of this technique. We use the B-mode signal to quantify this systematic error and to test methods for reducing this error. We show that two procedures are efficient in suppressing systematic error in the B-mode: (1) refinement of the mosaic CCD warping procedure to conform to absolute celestial coordinates and (2) truncation of the smoothing procedure on a scale of 10'. Application of these procedures reduces the systematic error to 20% of its original amplitude. We provide an analytic expression for the distribution of the highest peaks in noise maps that can be used to estimate the fraction of false peaks in the weak-lensing ?-signal-to-noise ratio (S/N) maps as a function of the detection threshold. Based on this analysis, we select a threshold S/N = 4.56 for identifying an uncontaminated set of weak-lensing peaks in two test fields covering a total area of ~3 deg2. Taken together these fields contain seven peaks above the threshold. Among these, six are probable systems of galaxies and one is a superposition. We confirm the reliability of these peaks with dense redshift surveys, X-ray, and imaging observations. The systematic error reduction procedures we apply are general and can be applied to future large-area weak-lensing surveys. Our high-peak analysis suggests that with an S/N threshold of 4.5, there should be only 2.7 spurious weak-lensing peaks even in an area of 1000 deg2, where we expect ~2000 peaks based on our Subaru fields. Based in part on data collected at Subaru Telescope and obtained from the SMOKA, which is operated by the Astronomy Data Center, National Astronomical Observatory of Japan.

Utsumi, Yousuke; Miyazaki, Satoshi; Geller, Margaret J.; Dell'Antonio, Ian P.; Oguri, Masamune; Kurtz, Michael J.; Hamana, Takashi; Fabricant, Daniel G.

2014-05-01

207

Quantitation of buried contamination by use of solvents. [degradation of silicone polymers by amine solvents  

NASA Technical Reports Server (NTRS)

Spore recovery form cured silicone potting compounds using amine solvents to degrade the cured polymers was investigated. A complete list of solvents and a description of the effect of each on two different silicone polymers is provided.

Pappas, S. P.; Hsiao, Y. C.; Hill, L. W.

1973-01-01

208

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

209

Continual coordination of shared activities  

NASA Technical Reports Server (NTRS)

Interacting agents that interleave planning and execution must reach consensus on their commitments to each other. For domains with varying degrees of interaction and different constraints on communication and computation, agents will require different coordination protocols in order to efficiently achieve their goals. ShAC (Shared Activity Coordination) is a framework for designing coordination protocols and an algorithm for continually coordinating agents using these protocols during execution. We show how a variety of protocols can be constructed using this framework and describe how ShAC coordinates two rovers and an orbiter in a simulated Mars scenario.

Clement, B. J.; Barrett, A.

2002-01-01

210

EXAFS study into the speciation of metal salts dissolved in ionic liquids and deep eutectic solvents.  

PubMed

The speciation of metals in solution controls their reactivity, and this is extremely pertinent in the area of metal salts dissolved in ionic liquids. In the current study, the speciation of 25 metal salts is investigated in four deep eutectic solvents (DESs) and five imidazolium-based ionic liquids using extended X-ray absorption fine structure. It is shown that in diol-based DESs M(I) ions form [MCl2](-) and [MCl3](2-) complexes, while all M(II) ions form [MCl4](2-) complexes, with the exception of Ni(II), which exhibits a very unusual coordination by glycol molecules. This was also found in the X-ray crystal structure of the compound [Ni(phen)2(eg)]Cl22eg (eg = ethylene glycol). In a urea-based DES, either pure chloro or chloro-oxo coordination is observed. In [C6mim][Cl] pure chloro complexation is also observed, but coordination numbers are smaller (typically 3), which can be explained by the long alkyl chain of the cation. In [C2mim][SCN] metal ions are entirely coordinated by thiocyanate, either through the N or the S atom, depending on the hardness of the metal ion according to the hard-soft acid-base principle. With weaker coordinating anions, mixed coordination between solvent and solute anions is observed. The effect of hydrate or added water on speciation is insignificant for the diol-based DESs and small in other liquids with intermediate or strong ligands. One of the main findings of this study is that, with respect to metal speciation, there is no fundamental difference between deep eutectic solvents and classic ionic liquids. PMID:24897923

Hartley, Jennifer M; Ip, Chung-Man; Forrest, Gregory C H; Singh, Kuldip; Gurman, Stephen J; Ryder, Karl S; Abbott, Andrew P; Frisch, Gero

2014-06-16

211

sition from a localized solvent-bound ground state to the continuum of the solvent conduc-  

E-print Network

sition from a localized solvent-bound ground state to the continuum of the solvent conduc- tion of the free es . Although the spectra are similar, the stark contrast between the differ- ence signals species account for es in the immediate and solvent-separated contact pairs. The ET reaction being

Kuhl, Tonya L.

212

Pre-activation based stereoselective glycosylations: Stereochemical control by additives and solvent  

PubMed Central

Stereochemical control is an important issue in carbohydrate synthesis. Glycosyl donors with participating acyl protective groups on 2-O have been shown to give 1,2-trans glycosides reliably under the pre-activation based reaction condition. In this work, the effects of additives and reaction solvents on stereoselectivity were examined using donors without participating protective groups on 2-O. While several triflate salt additives did not have major effects, the amount of AgOTf was found to significantly impact the reaction outcome. Excess AgOTf led to lower stereochemical control presumably due to its coordination with the glycosyl triflate intermediate and a more SN1 like reaction pathway. In contrast, the stereoselectivity could be directed by reaction solvents, with diethyl ether favoring the formation of ? glycosides and dichloromethane leading to ? isomers. The trend of stereochemical dependence on reaction solvent was applicable to a variety of building blocks including the selective formation of ?-mannosides. PMID:21547013

Gilbert, WASONGA; YouLin, ZENG; XueFei, HUANG

2011-01-01

213

Cytotoxic effects of gutta-percha solvents.  

PubMed

Cytotoxicity of commonly used gutta-percha solvents was evaluated. Gutta-percha dissolved by chloroform, halothane, or turpentine was evaluated with the radiochromium release method using L929 mouse fibroblast cells. All solvents were toxic. Turpentine was most toxic followed by halothane and chloroform, which caused similar levels of cell injury. PMID:8182389

Barbosa, S V; Burkard, D H; Spngberg, L S

1994-01-01

214

Supercritical-Multiple-Solvent Extraction From Coal  

NASA Technical Reports Server (NTRS)

Large and small molecules dissolve different constituents. Experimental apparatus used to test supercritical extraction of hydrogen rich compounds from coal in various organic solvents. In decreasing order of importance, relevant process parameters were found to be temperature, solvent type, pressure, and residence time.

Corcoran, W.; Fong, W.; Pichaichanarong, P.; Chan, P.; Lawson, D.

1983-01-01

215

Improved Supercritical-Solvent Extraction of Coal  

NASA Technical Reports Server (NTRS)

Raw coal upgraded by supercritical-solvent extraction system that uses two materials instead of one. System achieved extraction yields of 20 to 49 weight percent. Single-solvent yields are about 25 weight percent. Experimental results show extraction yields may be timedependent. Observed decreases in weight of coal agreed well with increases in ash content of residue.

Compton, L.

1982-01-01

216

Interaction of tantalum fluoride with organic solvents  

Microsoft Academic Search

A systematic study on the extraction of tantalum fluoride from various acidic solutions and mixed media has been given using\\u000a HDEHP, TBP and LA-2 as solvents. The results obtained for these three solvents clarify the ionic behaviour of tantalum. The\\u000a separation of tantalum from other elements is discussed.

W. Sanad; A. Haggag; N. Tadros

1978-01-01

217

Coal processing: the Exxon donor solvent process  

Microsoft Academic Search

The development of the Exxon coal liquefaction process over 10 years is described. Exxon is using lower temperatures and lower pressures (approximately 100 bar) than were used in the Bergius process. The donor solvent is produced in a separate, fixed bed, catalytic hydrogenation step. Early research was broad in scope including, both hydrogenated and unhydrogenated recycle solvent studies. Alternate solids\\/liquids

L. E. Furlong; E. Effron; L. W. Vernon; E. L. Wilson

1976-01-01

218

Classification of Solvents according to Interaction Mechanisms.  

ERIC Educational Resources Information Center

Presented is a model for solvent effects based on the observation that the excitation energy of all-trans-N-Retinylidenmethyl-n-butylammonium iodide is directly related to the dielectric constant of a series of aromatic and aliphatic solvents as the dielectric constant (e) ranges from 2 to 10.5. (BT)

Ahmed, Wasi

1979-01-01

219

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

220

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

221

Diluent Degradation Products in the Purex Solvent  

Microsoft Academic Search

A number of laboratory tests were conducted in which various impurities, known to be present in degraded Purex solvent, were injected into fresh solvent samples and the effects of these impurities tested in an operating miniature pulse column and in batch contactors. Common fission product elements which interfere in the Purex process were spiked with radiotracers and added to the

J. C. Neace

1983-01-01

222

ENHANCED PROCESSING OF GREEN SOLVENTS - PHASE I  

EPA Science Inventory

Solvents are a valuable processing tool in the chemical and related industries. Solvents are used to enhance mass transfer, heat transfer and in most cases are a processing aid and eventually are not used in the final product but to enhance the fabrication of the final pr...

223

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...

224

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

225

Weak percolation on multiplex networks  

NASA Astrophysics Data System (ADS)

Bootstrap percolation is a simple but nontrivial model. It has applications in many areas of science and has been explored on random networks for several decades. In single-layer (simplex) networks, it has been recently observed that bootstrap percolation, which is defined as an incremental process, can be seen as the opposite of pruning percolation, where nodes are removed according to a connectivity rule. Here we propose models of both bootstrap and pruning percolation for multiplex networks. We collectively refer to these two models with the concept of "weak" percolation, to distinguish them from the somewhat classical concept of ordinary ("strong") percolation. While the two models coincide in simplex networks, we show that they decouple when considering multiplexes, giving rise to a wealth of critical phenomena. Our bootstrap model constitutes the simplest example of a contagion process on a multiplex network and has potential applications in critical infrastructure recovery and information security. Moreover, we show that our pruning percolation model may provide a way to diagnose missing layers in a multiplex network. Finally, our analytical approach allows us to calculate critical behavior and characterize critical clusters.

Baxter, Gareth J.; Dorogovtsev, Sergey N.; Mendes, Jos F. F.; Cellai, Davide

2014-04-01

226

Recent Developments in Weak Lensing  

E-print Network

Measurement of the gravitational distortion of images of distant galaxies is rapidly becoming established as a powerful probe of the dark mass distribution in clusters of galaxies. With the advent of large mosaics of CCD's these methods should provide a composite total mass profile for galaxy haloes and also measure the power spectrum of mass fluctuations on supercluster scales. We describe how HST observations have been used to place the observational measurement of the shear on a quantitative footing. By artifically stretching and then degrading WFPC2 images to simulate ground based observing it is now possible to directly calibrate the effect of atmospheric seeing. Similar experiments show that one can remove the effect of artificial image anisotropy arising in the atmosphere or telescope. There have also been important advances in the interpretation of the shear: reconstruction techniques have been extended to encompass the strong distortion regime of giant arcs etc., progress has been made in removing a bias present in earlier reconstruction techniques, and we describe new techniques for `aperture densitometry'. We present some new results on clusters of galaxies, and discuss the intimate connections between weak lensing and deep spectroscopy.

Nick Kaiser; Gordon Squires; Greg Fahlman; David Woods; Tom Broadhurst

1994-11-07

227

CERT Coordination Center  

NSDL National Science Digital Library

The CERT Coordination Center is part of the Software Engineering Institute at Carnegie Mellon University. Its primary function is to work with industry to identify and eliminate Internet security vulnerabilities. Additionally, the center analyzes business and personal software to find potentially dangerous flaws that could compromise the system, meaning that both corporate and home users can benefit from the information offered on the Web site. There are continual updates of security advisories, survivability guides, and fixes that can help prevent disasters or speed recovery from them. Step-by-step suggestions make finding and implementing an efficient security practice reasonably painless. A wide range of papers and presentations on Internet and computer security research are available for free download.

1997-01-01

228

Stabilization of Underground Solvent Storage Tanks  

SciTech Connect

The Old Solvent Tanks (OST), located at the Savannah River Site (SRS) are comprised of 22 underground storage tanks that were used to store spent radioactive solvent and aqueous wastes generated from the plutonium-uranium extraction (PUREX) process. The OSTs were installed at various dates between 1955 and 1968 and used to store the spent solvents until 1974. The spent solvents stored in the OSTs were transferred out from 1976 through 1981 leaving only residual liquids and sludges that could not be pumped out.Final remediation goals include an overlying infiltration control system. If the tanks were to structurally fail, they would collapse causing potential for onsite worker exposure and release of tank contents to the environment. Therefore, as an interim action, methods for stabilizing the tanks were evaluated. This paper will discuss the systems designed to perform and monitor the grouting operation, the grouting process, and the radiological controls and wastes associated with grouting the Old Solvent Tanks.

Smail, T.R.

2003-08-15

229

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. PMID:22719183

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

2012-01-01

230

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...

231

Solvent-induced lone pair activity tuning and vapoluminescence in a Pt2Pb cluster.  

PubMed

We report a novel cluster, [{Pt(C6F5)(bzq)}2Pb(Spy)2] 1, that displays reversible vapoluminescence to specific organic vapours; this behaviour can be related to the stereochemical activity of the lone pair around the Pb(II) in the ground state and to the distinct distortion of the coordination environment (1 and 1-solvent) upon photoexcitation. PMID:23624681

Berenguer, Jess R; Lalinde, Elena; Martn, Antonio; Moreno, M Teresa; Ruiz, Santiago; Snchez, Sergio; Shahsavari, Hamid R

2013-06-01

232

Modeling the solubility of pharmaceuticals in pure solvents and solvent mixtures for drug process design.  

PubMed

The knowledge of the solubility of pharmaceuticals in pure solvents and solvent mixtures is crucial for designing the crystallization process of drug substances. The first step in finding optimal crystallization conditions is usually a solvent screening. Since experiments are very time consuming, a model which allows for solubility predictions in pure solvents and solvent mixtures based only on a small amount of experimental data is required. In this work, we investigated the applicability of the thermodynamic model perturbed-chain statistical associating fluid theory (PC-SAFT) to correlate and to predict the solubility of exemplary five typical drug substances and intermediates (paracetamol, ibuprofen, sulfadiazine, p-hydroxyphenylacetic acid, and p-aminophenylacetic acid) in pure solvents and solvent mixtures. PMID:19283772

Ruether, Feelly; Sadowski, Gabriele

2009-11-01

233

Pixelation Effects in Weak Lensing  

NASA Technical Reports Server (NTRS)

Weak gravitational lensing can be used to investigate both dark matter and dark energy but requires accurate measurements of the shapes of faint, distant galaxies. Such measurements are hindered by the finite resolution and pixel scale of digital cameras. We investigate the optimum choice of pixel scale for a space-based mission, using the engineering model and survey strategy of the proposed Supernova Acceleration Probe as a baseline. We do this by simulating realistic astronomical images containing a known input shear signal and then attempting to recover the signal using the Rhodes, Refregier, and Groth algorithm. We find that the quality of shear measurement is always improved by smaller pixels. However, in practice, telescopes are usually limited to a finite number of pixels and operational life span, so the total area of a survey increases with pixel size. We therefore fix the survey lifetime and the number of pixels in the focal plane while varying the pixel scale, thereby effectively varying the survey size. In a pure trade-off for image resolution versus survey area, we find that measurements of the matter power spectrum would have minimum statistical error with a pixel scale of 0.09' for a 0.14' FWHM point-spread function (PSF). The pixel scale could be increased to 0.16' if images dithered by exactly half-pixel offsets were always available. Some of our results do depend on our adopted shape measurement method and should be regarded as an upper limit: future pipelines may require smaller pixels to overcome systematic floors not yet accessible, and, in certain circumstances, measuring the shape of the PSF might be more difficult than those of galaxies. However, the relative trends in our analysis are robust, especially those of the surface density of resolved galaxies. Our approach thus provides a snapshot of potential in available technology, and a practical counterpart to analytic studies of pixelation, which necessarily assume an idealized shape measurement method.

High, F. William; Rhodes, Jason; Massey, Richard; Ellis, Richard

2007-01-01

234

Variational transition state theory evaluation of the rate constant for proton transfer in a polar solvent  

NASA Astrophysics Data System (ADS)

Variational transition state theory (VTST) is used to calculate rate constants for a model proton transfer reaction in a polar solvent. We start from an explicit description of the reacting solute in a solvent, and we model the effects of solvation on the reaction dynamics by a generalized Langevin equation (GLE) for the solute. In this description, the effects of solvation on the reaction energetics are included in the potential of mean force, and dynamical, or nonequilibrium, solvation is included by solvent friction. The GLE solvation dynamics are approximated by a collection of harmonic oscillators that are linearly coupled to the coordinates of the reacting system. This approach is applied to a model developed by Azzouz and Borgis [J. Chem. Phys. 98, 7361 (1993)] to represent proton transfer in a phenol-amine complex in liquid methyl chloride. In particular, semiclassical VTST, including multidimensional tunneling contributions, is applied to this model with three explicit solute coordinates and a multioscillator GLE description of solvation to calculate rate constants. We compare our computed rate constants and H/D kinetic isotope effects to previous calculations using other approximate dynamical theories, including approaches based on one-dimensional models, molecular dynamics with quantum transitions, and path integrals. By examining a systematic sequence of 18 different sets of approximations, we clarify some of the factors (such as classical vibrations, harmonic approximations, quantum character of reaction-coordinate motion, and nonequilibrium solvation) that contribute to the different predictions of various approximation schemes in the literature.

McRae, Robin P.; Schenter, Gregory K.; Garrett, Bruce C.; Svetlicic, Zoran; Truhlar, Donald G.

2001-11-01

235

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2009-07-01 true Default Organic HAP Contents of Solvents and Solvent Blends...to Subpart VVVV of Part 63Default Organic HAP Contents of Solvents and Solvent Blends...63.5758(a)(6), when detailed organic HAP content data for solvent blends...

2011-07-01

236

Weak-singlet fermions: Models and constraints  

SciTech Connect

We employ data from precision electroweak tests and collider searches to derive constraints on the possibility that weak-singlet fermions mix with the ordinary standard model fermions. Our findings are presented within the context of a theory with weak-singlet partners for all ordinary fermions and theories in which only third-generation fermions mix with weak singlets. In addition, we indicate how our results can be applied more widely in theories containing exotic fermions. (c) 2000 The American Physical Society.

Popovic, Marko B. [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States)] [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States); Simmons, Elizabeth H. [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States)] [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215 (United States)

2000-08-01

237

Rectified polymer translocation induced by solvent assymetry between cis and trans compartments  

NASA Astrophysics Data System (ADS)

We report Langevin dynamics simulation studies of translocation of a homopolymer through a nano pore driven by different solvent conditions at either side of the pore. The solvent at the cis compartment is modeled as a ``good solvent'' while the solvent at the trans side is modeled as a ``bad solvent'' so that the translocated beads of the polymer conforms to a globule and inhibits back translocation from the trans to the cis side. Therefore, the translocating polymer acts like a Brownian Ratchet. We study the translocation as a function of the dimensionless quantity ?/kBT, where ? is the strength of the attractive interaction at the cis side, kB is the Boltzmann constant, and T is the temperature respectively for several chain length N. We find that as N gets larger the mean translocation time N and shows a rather weak dependence on the parameter ?/kBT . This is consistent with the observation that excepting for the last few monomers, the velocity of the individual monomer s v(m) is roughly constant being independent of the monomer index m. We further discuss a plausible physical picture leading to such chain length dependence.

Lorscher, Christopher; Bhattacharya, Aniket; Ala-Nissila, Tapio

2010-03-01

238

Unusual effects of solvent polarity on capacitance for organic electrolytes in a nanoporous electrode.  

PubMed

The interplay between ions and solvent molecules inside the nanoporous electrodes of a supercapacitor has not been well understood but could be a fertile ground for new insights into the device's performance. By tuning the dipole moment of the solvent in an organic electrolyte, we find, from classical density functional theory calculations, pronounced oscillation of capacitance with the pore size for a moderately to weakly polar solvent. A quantitative analysis of the electric-double-layer (EDL) structure indicates that the capacitance oscillation shares a similar physical origin to that of an ionic liquid electrolyte: the oscillatory behavior arises from the formation of alternating layers of counterions and coions near strongly charged surfaces. More interestingly, we find that in the large-pore region, the capacitance versus the pore size has a volcano-shaped trend; in other words, there exists a solvent dipole moment that yields a maximal capacitance. These theoretical predictions can be validated with future experiments and highlight the great potential in tuning the organic solvent to achieve optimal performance of EDL capacitors. PMID:24733527

Jiang, De-en; Wu, Jianzhong

2014-05-21

239

Pseudo-Weak-R0 Algebras  

PubMed Central

A positive answer to the open problem of Iorgulescu on extending weak-R0 algebras and R0-algebras to the noncommutative forms is given. We show that pseudo-weak-R0 algebras are categorically isomorphic to pseudo-IMTL algebras and that pseudo-R0 algebras are categorically isomorphic to pseudo-NM algebras. Some properties, the noncommutative forms of the properties in weak-R0 algebras and R0-algebras, are investigated. The simplified axiom systems of pseudo-weak-R0 algebras and pseudo-R0 algebras are obtained.

Liu, Yong Lin; Cai, Xiaobo

2014-01-01

240

Robust hand-eye coordination  

Microsoft Academic Search

Industrial cameras are coupled into robotic systems to increase the flexibility of the robots. Such hand-eye coordination usually requires calibration of the cameras to compute the three-dimensional (3D) coordinates of positions in the robot space. This paper describes a new hand-eye coordination approach which does not require camera calibration. Instead, we propose the use of relative stereo disparity to compute

Wei-Yun Yau; Han Wang

1996-01-01

241

29 CFR 42.8 - Coordination plan.  

...2014-07-01 2013-07-01 true Coordination plan. 42.8 Section 42.8 ...COORDINATED ENFORCEMENT 42.8 Coordination plan. (a) Based upon, among...National Committee shall develop an annual coordination plan concerning farm...

2014-07-01

242

29 CFR 42.8 - Coordination plan.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Coordination plan. 42.8 Section 42.8 ...COORDINATED ENFORCEMENT 42.8 Coordination plan. (a) Based upon, among...National Committee shall develop an annual coordination plan concerning farm...

2012-07-01

243

29 CFR 42.8 - Coordination plan.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Coordination plan. 42.8 Section 42.8 ...COORDINATED ENFORCEMENT 42.8 Coordination plan. (a) Based upon, among...National Committee shall develop an annual coordination plan concerning farm...

2013-07-01

244

29 CFR 1915.32 - Toxic cleaning solvents.  

Code of Federal Regulations, 2010 CFR

... 7 2010-07-01 2010-07-01 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...

2010-07-01

245

Weak homology of elliptical galaxies.  

NASA Astrophysics Data System (ADS)

Studies of the Fundamental Plane of early-type galaxies, from small to intermediate redshifts, are generally carried out under the guiding principle that the Fundamental Plane reflects the existence of an underlying mass-luminosity relation for such galaxies, in a scenario where galaxies are homologous systems in dynamical equilibrium. In this paper we re-examine the question of whether a systematic non-homology could be partly responsible for the correlations that define the Fundamental Plane. We start by studying a small set of objects characterized by photometric profiles that have been pointed out to deviate significantly from the standard R1/4 law. For these objects we confirm that a generic R1/n law, with n a free parameter, can provide superior fits (the best-fit value of n can be lower than 2.5 or higher than 10), better than those that can be obtained by a pure R1/4 law, by an R1/4 + exponential model, and by other dynamically justified self-consistent models. Therefore, strictly speaking, elliptical galaxies should not be considered homologous dynamical systems. Still, a case for weak homology, useful for the interpretation of the Fundamental Plane, could be made if the best-fit parameter n, as often reported, correlates with galaxy luminosity L, provided the underlying dynamical structure also follows a systematic trend with luminosity. We demonstrate that this statement may be true even in the presence of significant scatter in the correlation n(L). Preliminary indications provided by a set of ``data points" associated with a sample of 14 galaxies suggest that neither the strict homology nor the constant stellar mass-to-light solution are a satisfactory explanation of the observed Fundamental Plane. These conclusions await further extensions and clarifications, because the class of low-luminosity early-type galaxies, which contribute significantly to the Fundamental Plane, falls outside the simple dynamical framework considered here and because dynamical considerations should be supplemented with other important constraints derived from the evolution of stellar populations.

Bertin, G.; Ciotti, L.; Del Principe, M.

2002-04-01

246

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

247

Exploring Hamiltonian dielectric solvent molecular dynamics  

NASA Astrophysics Data System (ADS)

Hamiltonian dielectric solvent (HADES) is a recent method [7,25], which enables Hamiltonian molecular dynamics (MD) simulations of peptides and proteins in dielectric continua. Sample simulations of an ?-helical decapeptide with and without explicit solvent demonstrate the high efficiency of HADES-MD. Addressing the folding of this peptide by replica exchange MD we study the properties of HADES by comparing melting curves, secondary structure motifs and salt bridges with explicit solvent results. Despite the unoptimized ad hoc parametrization of HADES, calculated reaction field energies correlate well with numerical grid solutions of the dielectric Poisson equation.

Bauer, Sebastian; Tavan, Paul; Mathias, Gerald

2014-09-01

248

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

249

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

250

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

251

Switchable solvents and methods of use thereof  

DOEpatents

A solvent that reversibly converts from a nonionic liquid mixture to an ionic liquid upon contact with a selected trigger, e.g., contact with CO.sub.2, is described. In preferred embodiments, the ionic solvent is readily converted back to the nonionic liquid mixture. The nonionic liquid mixture includes an amidine or guanidine or both, and water, alcohol, or a combination thereof. Single component amine solvents that reversibly convert between ionic and non-ionic states are also described. Some embodiments require increased pressure to convert; others convert at 1 atmosphere.

Jessop, Philip G. (Kingston, CA); Eckert, Charles A. (Atlanta, GA); Liotta, Charles L. (Atlanta, GA); Heldebrant, David J. (Richland, WA)

2011-07-19

252

Switchable solvents and methods of use thereof  

DOEpatents

A solvent that reversibly converts from a nonionic liquid mixture to an ionic liquid upon contact with a selected trigger, e.g., contact with CO.sub.2, is described. In preferred embodiments, the ionic solvent is readily converted back to the nonionic liquid mixture. The nonionic liquid mixture includes an amidine or guanidine or both, and water, alcohol, or a combination thereof. Single component amine solvents that reversibly convert between ionic and non-ionic states are also described. Some embodiments require increased pressure to convert; others convert at 1 atmosphere.

Jessop, Philip G.; Eckert, Charles A.; Liotta, Charles L.; Heldebrant, David J.

2013-08-20

253

GUIDE FOR APPLICANTS COORDINATION AND SUPPORT ACTION  

E-print Network

1 GUIDE FOR APPLICANTS NMP COORDINATION AND SUPPORT ACTION (COORDINATING) FP7-NMP-2010-CSA-4: Coordination and support action (Coordinating) FP7-NMP-2010-CSA-4 i About this Guide This is version number 4: Coordination and support action (Coordinating) FP7-NMP-2010-CSA-4 ii Contents 1. GETTING STARTED

Milano-Bicocca, Università

254

Construction of prototype system for directional solvent extraction desalination.  

E-print Network

??Directional solvent extraction has been demonstrated as a low temperature, membrane free desalination process. This method dissolves the water into an inexpensive, benign directional solvent, (more)

Fowler, Michael James

2012-01-01

255

A spectrochemical walk: single-site perturbation within a series of six-coordinate ferrous complexes.  

PubMed

A series of ferrous complexes with the pentadentate ligand 2,6-(bis-(bis-2-pyridyl)methoxymethane)pyridine (PY5) was prepared and examined. PY5 binds ferrous iron in a square-pyramidal geometry, leaving a single coordination site accessible for complexation of a wide range of monodentate exogenous ligands: [Fe(II)(PY5)(X)](n+), X = MeOH, H(2)O, MeCN, pyridine, Cl-, OBz-, N(3)-, MeO-, PhO-, and CN-. The spin-states of these ferrous complexes are extremely sensitive to the nature of the single exogenous ligand; the spectroscopic and structural properties correlate with their high-spin (hs) or low-spin (ls) electronic ground state. Systematic metrical trends within six crystallographic structures clearly indicate a preferred conformational binding mode of the PY5 ligand. The relative binding affinities of the exogenous ligands in MeOH indicate that exogenous ligand charge is the primary determinant of the binding affinity; the [Fe(II)(PY5)](2+) unit preferentially binds anionic ligands over neutral ligands. At parity of charge, strong-field ligands are preferentially bound over weak-field ligands. In MeOH, the pK(a) of the exogenously ligated MeOH in [Fe(PY5)(MeOH)](2+) (9.1) limits the scope of exogenous ligands, as strongly basic ligands preferentially deprotonate [Fe(PY5)(MeOH)](2+) to yield [Fe(PY5)(OMe)](1+) rather than ligate to the ferrous center. Exogenous ligation by a strongly basic ligand, however, can be achieved in polar aprotic solvents. PMID:12206687

Goldsmith, Christian R; Jonas, Robert T; Cole, Adam P; Stack, T Daniel P

2002-09-01

256

Weak Separability in Applied Welfare Analysis  

Microsoft Academic Search

The focus of this paper is the impact on welfare measurement of a common assumption in applied demand analysis, weak separability. A standard empirical practice is to estimate conditional demand models for a set of goods which are assumed to be weakly separable from all other goods with expenditure as a right-hand-side variable, tacitly assuming that expenditure is predetermined (Alston

Jeffrey T. LaFrance

1993-01-01

257

WEAK MEASUREMENT IN QUANTUM MECHANICS ABRAHAM NEBEN  

E-print Network

WEAK MEASUREMENT IN QUANTUM MECHANICS ABRAHAM NEBEN PHYS 342 Final Project March 10, 2011 Contents of Postselection 4 4. Impossible Spin Measurements 5 5. Hardy's Paradox 5 6. Controversy over Weak Measurement 8 7 of a Measurement of a Component of the Spin of a Spin-1/2 Particle Can Turn Out to be 100." [1] The topic

Rosner, Jonathan L.

258

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

259

SEEING AND COMMUNICATING THROUGH WEAK ELECTRIC  

E-print Network

Inside JEB i SEEING AND COMMUNICATING THROUGH WEAK ELECTRIC FIELDS Weakly electric fish spend their lives bathed in their own internally generated mild electric field, interpreting perturbations frequency electric `chirps'. Rüdiger Krahe, from McGill University, Canada, says, `These fish are very

260

Innovative Technologies for Chlorinated Solvent Remediation  

NASA Astrophysics Data System (ADS)

The following sections are included: * INTRODUCTION * TRADITIONAL REMEDIATION TECHNOLOGIES (1980s) * RESEARCH AND DEVELOPMENT OF INNOVATIVE REMEDIATION TECHNOLOGIES (1990s-2000s) * CURRENT TRENDS IN CHLORINATED SOLVENT REMEDIATION (2010s) * CLOSING THOUGHTS * REFERENCES

Pennell, Kurt D.; Cpiro, Natalie L.

2014-07-01

261

SOLVENT EXTRACTION OF ORGANIC WATER POLLUTANTS  

EPA Science Inventory

Based on experiments with model systems of known organic water pollutants and environmental samples, conclusions are reached concerning the best general solvent for extraction and the most appropriate methods for related manipulations. Chloroform, methylene chloride-ether mixture...

262

Optimizing injected solvent fraction in stratified reservoirs  

E-print Network

low permeability layers may be scarcely swept at all. Presence or absence of transverse communication between layers can modify overall sweep efficiency. This work is a study of water-solvent injection in stratified reservoirs based on computer...

Moon, Gary Michael

2012-06-07

263

Modeling americium separations in stagewise solvent extraction  

SciTech Connect

The TRUEX solvent includes octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide, TBP, and diluents (NPH, organic halide). Distribution coefficients are given for americium, etc. Worksheets, diagrams, etc. are included. (DLC)

Leonard, R.A.

1987-01-01

264

"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

265

United States Air Force Wipe Solvent Testing  

NASA Technical Reports Server (NTRS)

The Wright-Patterson Air Force Base (WPAFB), as part of the Air Force Material Command, requested that NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) conduct testing and analyses in support of the United States Air Force Wipe Solvent Development Project. The purpose of the wipe solvent project is to develop an alternative to be used by Air Force flight line and maintenance personnel for the wipe cleaning of oxygen equipment. This report provides material compatibility, liquid oxygen (LOX) mechanical impact, autogenous ignition temperature (AIT), and gauge cleaning test data for some of the currently available solvents that may be used to replace CFC-113 and methyl chloroform. It provides data from previous WSTF test programs sponsored by the Naval Sea Systems Command, the Kennedy Space Center, and other NASA programs for the purpose of assisting WP AFB in identifying the best alternative solvents for validation testing.

Hornung, Steven D.; Beeson, Harold D.

2000-01-01

266

Learning, Local Interaction, and Coordination  

Microsoft Academic Search

This paper discusses the dynamic implications of learning in a large population coordination game, focusing on the structure of the matching process that describes how players meet. As in M. Kandori, G. Mailath, and R. Rob (1992), experimentation and myopia create 'evolutionary' forces that lead players to coordinate on the risk dominant equilibrium. To describe play with finite time horizons,

Glenn Ellison

1993-01-01

267

Channel Coordination and Quantity Discounts  

Microsoft Academic Search

This paper presents a model for analyzing the impact of joint decision policies on channel coordination in a system consisting of a supplier and a group of homogeneous buyers. The joint decision policy characterized by the unit selling price and the order quantity is coordinated through quantity discounts and franchise fees. Both the annual demand rate and the operating cost---including

Z. Kevin Weng

1995-01-01

268

Coordination challenges for autonomous spacecraft  

NASA Technical Reports Server (NTRS)

While past flight projects involved a single spacecraft in isolation, over forty proposed future missions involve multiple coordinated spacecraft. This paper presents characteristics of such missions in terms of properties of the phenomena being measured as well as the rationale for using multiple spacecraft. We describe the coordination problems associated with operating these missions and identify needed technologies.

Clement, B. J.; Barrett, A.

2002-01-01

269

Coordinate-Free Rotation Operator.  

ERIC Educational Resources Information Center

Suggests the use of a coordinate-free rotation operator for the teaching of rotations in Euclidean three space because of its twofold didactic advantage. Illustrates the potentialities of the coordinate-free rotation operator approach by a number of examples. (Author/GA)

Leubner, C.

1979-01-01

270

A SCHEMA FOR SENTENCE COORDINATION.  

ERIC Educational Resources Information Center

A COORDINATION SCHEMA IS DESCRIBED WHICH HAS BEEN INTRODUCED IN THE "MITRE" GRAMMAR. THIS SCHEMA DEALS WITH THE TYPE OF COORDINATION WHERE A SINGLE SENTENCE OF TWO OR MORE CONSTITUENTS ALLOWS FOR A PARAPHRASE OF TWO OR MORE SEPARATE SENTENCES WHICH ARE IDENTICAL IN EVERY RESPECT EXCEPT FOR THE CONJOINABLE MEMBERS. THE NEW APPROACH REPLACES EARLIER

SCHANE, SANFORD A.

271

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

272

What Happened to Service Coordination?  

ERIC Educational Resources Information Center

Comments on an article by Dunst and Bruder. Service coordination was supposed to be one of the major jewels in the legislative crown for young children with disabilities and their families. The authors have cast their experienced eyes on the heart of the matter, which is the models of service coordination that sprang to life almost immediately

McWilliam, R. A.

2006-01-01

273

Newtonian and relativistic emission coordinates  

SciTech Connect

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, Bartolome; Ferrando, Joan Josep; Morales-Lladosa, Juan Antonio [Departament d'Astronomia i Astrofisica, Universitat de Valencia, 46100 Burjassot, Valencia (Spain)

2009-09-15

274

Cobalt(II) chloride complexes with 1,1'-dimethyl-4,4'-bipyrazole featuring first- and second-sphere coordination of the ligand.  

PubMed

In catena-poly[[dichloridocobalt(II)]-?-(1,1'-dimethyl-4,4'-bipyrazole-?(2)N(2):N(2'))], [CoCl2(C8H10N4)]n, (1), two independent bipyrazole ligands (Me2bpz) are situated across centres of inversion and in tetraaquabis(1,1'-dimethyl-4,4'-bipyrazole-?N(2))cobalt(II) dichloride-1,1'-dimethyl-4,4'-bipyrazole-water (1/2/2), [Co(C8H10N4)2(H2O)4]Cl22C8H10N42H2O, (2), the Co(2+) cation lies on an inversion centre and two noncoordinated Me2bpz molecules are also situated across centres of inversion. The compounds are the first complexes involving N,N'-disubstituted 4,4'-bipyrazole tectons. They reveal a relatively poor coordination ability of the ligand, resulting in a Co-pyrazole coordination ratio of only 1:2. Compound (1) adopts a zigzag chain structure with bitopic Me2bpz links between tetrahedral Co(II) ions. Interchain interactions occur by means of very weak C-H...Cl hydrogen bonding. Complex (2) comprises discrete octahedral trans-[Co(Me2bpz)2(H2O)4](2+) cations formed by monodentate Me2bpz ligands. Two equivalents of additional noncoordinated Me2bpz tectons are important as `second-sphere ligands' connecting the cations by means of relatively strong O-H...N hydrogen bonding with generation of doubly interpenetrated pcu (?-Po) frameworks. Noncoordinated chloride anions and solvent water molecules afford hydrogen-bonded [(Cl(-))2(H2O)2] rhombs, which establish topological links between the above frameworks, producing a rare eight-coordinated uninodal net of {4(24).5.6(3)} (ilc) topology. PMID:24594715

Domasevitch, Konstantin V

2014-03-01

275

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

276

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

277

Solvent extraction of phenols from water  

Microsoft Academic Search

Methyl isobutyl ketone (MIBK) and diisopropyl ether (DIPE) have been evaluated as solvents for extraction of phenols, at high dilution, from water. Equilibrium distribution coefficients (K\\/sub D\\/) have been measured for phenol, dihydroxybenzenes and trihydroxybenzenes in both solvents as a function of pH. Particularly for the multihydric phenols, MIBK gives substantially higher values of K\\/sub D\\/ than does DIPE. The

D. C. Greminger; G. P. Burns; S. Lynn; D. H. Hanson; C. J. King

1980-01-01

278

Solvent-based preferential deposition of functionalized carbon nanotubes on substrates  

NASA Astrophysics Data System (ADS)

Solution-processed deposition of carbon nanotubes (CNTs) provides a cost-effective means to synthesize uniform vertically or horizontally aligned nanostructures on top of substrates. The efficacy of deposition depends on the solubility of CNTs in the solvent as well as the ordering of nanotubes relative to the substrates. These governing factors, which determine the specific morphologies of CNTs that are deposited, are determined by the molecular interactions between the CNTs and the substrate and solvent molecules. In an effort to mimic the conditions during solution-processed deposition of nanotubes on substrates, we employed molecular dynamics (MD) simulations to study systems comprising CNTs and commonly used solvents toluene and acetone sandwiched between silicon substrates. Both charged and uncharged substrates were simulated to evaluate the effect of electrostatic interactions between nanotubes and substrate on deposition. Comparison of simulated systems with pure and functionalized CNTs indicate that the presence of -COOH functional groups in CNTs is necessary for uniform deposition on substrates. Time-averaged distribution of the angles formed between the axes of the CNTs and that between the nanotubes and substrates demonstrate that functionalized carbon nanotubes (FCNTs) align parallel with the substrates to a greater extent when toluene is used as a solvent. Time-averaged density distributions obtained from our simulations illustrate that FCNTs tend to migrate towards the substrates, especially when the substrates have finite charge density. However, polar acetone molecules form layers on the substrates and thus lead to electrostatic shielding between nanotubes and substrates that hinders deposition. Hence, non-polar solvents such as toluene are more effective for deposition of nanotubes. Based on radial distribution functions (RDFs) and coordination numbers of various atoms of CNTs with respect to solvent atoms as well as with respect to that of other CNTs, we present a hypothesis that relative extent of coordination between solvent molecules and the functional groups and graphitic component of CNTs determine the solubility and the propensity of parallel alignment of FCNTs in solvents. Overall, results presented in this study provide fundamental insight to predict key factors for solution-processed deposition of well-ordered CNTs on silicon substrates.

Mortuza, S. M.; Banerjee, Soumik

2013-08-01

279

Spectroscopic studies on the cation-anion, cation-solvent and anion-solvent interactions in the LiCF3SO3/acetamide complex system.  

PubMed

A molten salt electrolyte composed of lithium triflate (LiCF3SO3) and acetamide (CH3CONH2) has been prepared and characterized by Raman, IR spectroscopy and ac impedance. It is found that acetamide molecule not only complexes with the Li+ cation but also interacts with the CF3SO3- anion via hydrogen bonding due to its two polar groups (C=O group and NH2 group) capable of coordinating with cations and anions, respectively. Cation-anion interaction is strengthened while cation-solvent and anion-solvent interactions are weakened with the increases of salt concentration and temperature in the LiCF3SO3/acetamide complex. The ionic conductivities of the LiCF3SO3/acetamide complex with different molar ratios depend strongly on the ionic association in the complex system. PMID:15582807

Hu, Yongsheng; Wang, Zhaoxiang; Li, Hong; Huang, Xuejie; Chen, Liquan

2005-01-14

280

Influence of solvent polarity on preferential solvation of molecular recognition probes in solvent mixtures.  

PubMed

The association constants for formation of 1:1 complexes between a H-bond acceptor, tri-n-butylphosphine oxide, and a H-bond donor, 4-phenylazophenol, have been measured in a range of different solvent mixtures. Binary mixtures of n-octane and a more polar solvent (ether, ester, ketone, nitrile, sulfoxide, tertiary amide, and halogenated and aromatic solvents) have been investigated. Similar behavior was observed in all cases. When the concentration of the more polar solvent is low, the association constant is identical to that observed in pure n-octane. Once a threshold concentration of the more polar solvent in reached, the logarithm of the association constant decreases in direct proportion to the logarithm of the concentration of the more polar solvent. This indicates that one of the two solutes is preferentially solvated by the more polar solvent, and it is competition with this solvation equilibrium that determines the observed association constant. The concentration of the more polar solvent at which the onset of preferential solvation takes place depends on solvent polarity: 700 mM for toluene, 60 mM for 1,1,2,2-tetrachloroethane, 20 mM for the ether, ester, ketone, and nitrile, 0.2 mM for the tertiary amide, and 0.1 mM for the sulfoxide solvents. The results can be explained by a simple model that considers only pairwise interactions between specific sites on the surfaces of the solutes and solvents, which implies that the bulk properties of the solvent have little impact on solvation thermodynamics. PMID:23190174

Amenta, Valeria; Cook, Joanne L; Hunter, Christopher A; Low, Caroline M R; Vinter, Jeremy G

2012-12-13

281

Series of solvent-induced single-crystal to single-crystal transformations with different sizes of solvent molecules.  

PubMed

A highly stable soft porous coordination polymer (PCP), namely [Cu3(TP)4(N3)2(DMF)2]2H2O2DMF (1), has been synthesized via an in situ synthesis of 4-tetrazole pyridine (TP) under solvothermal conditions (DMF = N,N'-dimethylformamide). Remarkably, the solvent molecules in 1 can be respectively exchanged with cyclohexane (C6H12), cyclopentane (C5H10), decahydronaphthalene (C10H18), 1,4-dioxane (C4H8O2), and tetrahydropyrane (C5H10O) in single-crystal to single-crystal (SCSC) manners to yield [Cu3(TP)4(N3)2(DMF)2]3C6H12 (1a), [Cu3(TP)4(N3)2(DMF)2]2C5H10 (1b), [Cu3(TP)4(N3)2(DMF)2]H2OC10H18 (1c), [Cu3(TP)4(N3)2(DMF)2]C4H8O2 (1d), [Cu3(TP)4(N3)2]3C4H8O2 (1e), and [Cu3(TP)4(N3)2]2H2OC5H10O (1f). Further, the occluded cyclohexane molecules in 1a can be removed by heating to give its porous guest-free form [Cu3(TP)4(N3)2(DMF)2] (1g). Particularly, in water, 1 can lose its coordinated N3(-) anions to generate [Cu(TP)2(H2O)4]4H2O (1h). More interestingly, the soft PCP (1) demonstrates the guest selectivity for the cycloalkane solvents, namely cyclohexane, cyclopentane, and decahydronaphthalene, in SCSC manners for the first time, attributed to the synergy effect between the size and geometry of the solvent and the shape of the framework cavity. Moreover, the desolvated samples of 1e show the highly selective gas adsorption of CO2 over N2, indicating its potential application in the separation of the CO2/N2 mixture. PMID:24983509

He, Yuan-Chun; Yang, Jin; Liu, Ying-Ying; Ma, Jian-Fang

2014-07-21

282

Phase separation phenomena of polysulfone/solvent/organic nonsolvent and polyethersulfone/solvent/organic nonsolvent systems  

SciTech Connect

The precipitation values (PVs) of several organic nonsolvents in polysulfone (PSf)/solvent and polyethersulfone (PESf)/solvent systems were measured in temperatures ranging from 10 to 80 C by the direct titration method and compared with those of water in the same systems. The solvents used were N-methyl-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMAC); the organic nonsolvents employed were methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, ethylene glycol, and diethylene glycol as well as acetic acid and propionic acid. The compositions of nonsolvent, polymer, and solvent at the precipitation points for different polymer concentrations up to 10 wt% were also determined at 30 C with respect to both the polymers and six nonsolvents presented. These results were used to obtain the polymer precipitation curves in the polymer-solvent-nonsolvent triangular phase diagrams and to determine the theta composition of solvent-nonsolvent triangular phase diagrams and to determine the theta composition of solvent-nonsolvent for a polymer. The effect of temperature on the precipitation value was observed to be dramatically different for different polymer/solvent/nonsolvent systems. These results were explained on the basis of polar and nonpolar interactions of the polymer, solvent, and nonsolvent system.

Wang, Dongliang; Li, K.; Sourirajan, S.; Teo, W.K. (National Univ. of Singapore, Kent Ridge Crescent (Singapore). Dept. of Chemical Engineering)

1993-12-10

283

Nonlinear response of a linear chain to weak driving  

NASA Astrophysics Data System (ADS)

We study the escape of a chain of coupled units over the barrier of a metastable potential. It is demonstrated that a very weak external driving field with a suitably chosen frequency suffices to accomplish speedy escape. The latter requires passage through a transition state, the formation of which is triggered by permanent feeding of energy from a phonon background into humps of localized energy and elastic interaction of the arising breather solutions. In fact, cooperativity between the units of the chain entailing coordinated energy transfer is shown to be crucial for enhancing the rate of escape in an extremely effective and low-energy cost way where the effects of entropic localization and breather coalescence conspire.

Hennig, D.; Mulhern, C.; Burbanks, A. D.; Schimansky-Geier, L.

2014-01-01

284

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

285

Model evaluation experiments in the North Atlantic Basin: simulations in nonlinear terrain-following coordinates  

Microsoft Academic Search

A primitive equation ocean circulation model in nonlinear terrain-following coordinates is applied to a decadal-length simulation of the circulation in the North Atlantic Ocean. In addition to the stretched sigma coordinate, novel features of the model include the utilization of a weakly dissipative, third-order scheme for tracer advection, and a conservative and constancy-preserving time-stepping algorithm. The objectives of the study

Dale B. Haidvogel; Hernan G. Arango; Kate Hedstrom; Aike Beckmann; Paola Malanotte-Rizzoli; Alexander F. Shchepetkin

2000-01-01

286

Weak Gauge Boson Radiation in Parton Showers  

E-print Network

The emission of W and Z gauge boson is included in a traditional QCD + QED shower. The unitarity of the shower algorithm links the real radiation of the weak gauge bosons to the negative weak virtual corrections. The shower evolution process leads to a competition between QCD, QED and weak radiation, and allows for W and Z boson production inside jets. Various effects on LHC physics are studied, both at low and high transverse momenta, and effects at higher-energy hadron colliders are outlined.

Jesper Roy Christiansen; Torbjrn Sjstrand

2014-01-21

287

Quantum correlation cost of the weak measurement  

E-print Network

Quantum correlation cost (QCC) characterizing how much quantum correlation is used in a weak-measurement process is presented based on the trace norm. It is shown that the QCC is related to the trace-norm-based quantum discord (TQD) by only a factor that is determined by the strength of the weak measurement, so it only catches partial quantumness of a quantum system compared with the TQD. We also find that the residual quantumness can be `extracted' not only by the further von Neumann measurement, but also by a sequence of infinitesimal weak measurements. As an example, we demonstrate our outcomes by the Bell-diagonal state.

Jun Zhang; Shao-xiong Wu; Chang-shui Yu

2014-09-14

288

Molecular design of solvents for liquid extraction based on UNIFAC  

Microsoft Academic Search

Cm the basis of the UNIFAC group contribution method, it is proposed to syn- thesize molecular structures with specific solvent properties for the separation of aromatic and paraffinic hydrocarbons. The potential solvents were studied with regard to their solvent power, selectivity and binoclal c-e on the basis of UNIFAC predictions. In this way good potential solvents were found. In gen-

R. GANI; E. A. BRIGNOLE

1983-01-01

289

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

290

Neuromuscular Contributions to Age-Related Weakness  

PubMed Central

Background. Declines in skeletal muscle mass and quality are important factors contributing to age-related weakness. Neural activation of agonist and antagonist muscles may also be important contributing factors. Methods. We conducted a review of the scientific literature on older adults to determine (a) methodologies used to quantify activation, (b) the potential role of agonist and antagonist activation on weakness, and (c) some possible neurophysiological mechanisms that may underlie impaired activation. Results. The cumulative evidence indicates that agonist activation is impaired in some, but not all, older adults and that this impairment contributes to age-related weakness. It is possible that antagonist coactivation also plays a role in age-related weakness, though a definitive link has not been established. Conclusion. Future research should focus on improving quantitative measurement and mechanistic understanding of impaired activation with aging. PMID:21415261

Clark, David J.

2012-01-01

291

Superfluid 3 He Josephson weak links  

E-print Network

links displaying a variety of I( )'s 755 C. states 755 X. Pendulum Mode 757 XI. Shapiro Effect 758 XII. II. JOSEPHSON EQUATIONS A` LA FEYNMAN The governing equations for two weakly coupled mac- roscopic quantum systems can be deriv

Packard, Richard E.

292

Anomalous weak values are proofs of contextuality  

E-print Network

The average result of a weak measurement of some observable $A$ can, under post-selection of the measured quantum system, exceed the largest eigenvalue of $A$. The nature of weak measurements, as well as the presence of post-selection and hence possible contribution of measurement-disturbance, has led to a long-running debate about whether or not this is surprising. Here, it is shown that such "anomalous weak values" are non-classical in a precise sense: a sufficiently weak measurement of one constitutes a proof of contextuality. This clarifies, for example, which features must be present (and in an experiment, verified) to demonstrate an effect with no satisfying classical explanation.

Matthew F. Pusey

2014-09-04

293

Weak Charge of 133 Walter Johnson  

E-print Network

Atomic PNC and the Weak Charge of 133 Cs Walter Johnson Department of Physics Notre Dame University http://www.nd.edu/johnson June 21, 2002 Abstract Atomic PNC measurements and calculations are reviewed

Johnson, Walter R.

294

Precision frontier in semileptonic weak interactions: theory  

NASA Astrophysics Data System (ADS)

Recent advances in experimental physics have opened a new frontier for the precision measurements in low energy weak interactions. In this note we discuss the theoretical basis for the analysis of such experiments and their implications for the standard model.

Holstein, Barry R.

2014-11-01

295

Amplification of Angular Rotations Using Weak Measurements  

NASA Astrophysics Data System (ADS)

We present a weak measurement protocol that permits a sensitive estimation of angular rotations based on the concept of weak-value amplification. The shift in the state of a pointer, in both angular position and the conjugate orbital angular momentum bases, is used to estimate angular rotations. This is done by an amplification of both the real and imaginary parts of the weak-value of a polarization operator that has been coupled to the pointer, which is a spatial mode, via a spin-orbit coupling. Our experiment demonstrates the first realization of weak-value amplification in the azimuthal degree of freedom. We have achieved effective amplification factors as large as 100, providing a sensitivity that is on par with more complicated methods that employ quantum states of light or extremely large values of orbital angular momentum.

Magaa-Loaiza, Omar S.; Mirhosseini, Mohammad; Rodenburg, Brandon; Boyd, Robert W.

2014-05-01

296

Amplification of Angular Rotations Using Weak Measurements  

E-print Network

We present a weak measurement protocol that permits a sensitive estimation of angular rotations based on the concept of weak-value amplification. The shift in the state of a pointer, in both angular position and the conjugate orbital angular momentum bases, is used to estimate angular rotations. This is done by an amplification of both the real and imaginary parts of the weak-value of a polarization operator that has been coupled to the pointer, which is a spatial mode, via a spin-orbit coupling. Our experiment demonstrates the first realization of weak-value amplification in the azimuthal degree of freedom. We have achieved effective amplification factors as large as 100, providing a sensitivity that is on par with more complicated methods that employ quantum states of light or extremely large values of orbital angular momentum.

Omar S. Magana-Loaiza; Mohammad Mirhosseini; Brandon Rodenburg; Robert W. Boyd

2013-12-10

297

Strengthening weak value amplification with recycled photons  

E-print Network

We consider the use of cyclic weak measurements to improve the sensitivity of weak-value amplification precision measurement schemes. Previous weak-value experiments have used only a small fraction of events, while discarding the rest through the process of "post-selection". We extend this idea by considering recycling of events which are typically unused in a weak measurement. Here we treat a sequence of polarized laser pulses effectively trapped inside an interferometer using a Pockels cell and polarization optics. In principle, all photons can be post-selected, which will improve the measurement sensitivity. We first provide a qualitative argument for the expected improvements from recycling photons, followed by the exact result for the recycling of collimated beam pulses, and numerical calculations for diverging beams. We show that beam degradation effects can be mitigated via profile flipping or Zeno reshaping. The main advantage of such a recycling scheme is an effective power increase, while maintaining an amplified deflection.

Justin Dressel; Kevin Lyons; Andrew N. Jordan; Trent M. Graham; Paul G. Kwiat

2013-05-20

298

Chlorinated solvent replacements recycle/recovery review report  

SciTech Connect

This report is a literature review of waste solvents recycle/recovery methods and shows the results of solvent separations using membrane and distillation technologies. The experimental solvent recovery methods were conducted on solvent replacements for chlorinated solvents at Montana State University. The literature review covers waste solvents separation using distillation, membranes decantation, filtration, carbon adsorption, solvent extraction, and other vapor-phase separation techniques. The results of this study identify solvent distillation methods as the most common separation technique. The alternative separation methods typically supplement distillation. The study shows the need for industries to identify waste solvent disposal methods and investigate the economics of waste solvent recycling as a possible waste reduction method.

Beal, M.; Hsu, D.; McAtee, R.E.; Weidner, J.R. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Berg, L.; McCandless, F.P.; Waltari, S.; Peterson, C. [Montana State Univ., Bozeman, MT (United States). Dept. of Chemical Engineering

1992-08-01

299

(Academic Coordinator) Program Representative II  

E-print Network

Administrator) Marc LevisFitzgerald Internship Coordinators Special Seminars (Fiat Lux Freshman Seminars SENATE INTERFACE OPERATIONS INTERFACE Undergraduate Information Technology (UIT) Course Information Faculty Executive Committee Raymond Knapp,Chair GE Governance Committee Robert Gurval, Chair Undergraduate

Grether, Gregory

300

Solvent/Non-Solvent Sintering: A Novel Route to Create Porous Microsphere Scaffolds For Tissue Regeneration  

PubMed Central

Solvent/non-solvent sintering creates porous polymeric microsphere scaffolds suitable for tissue engineering purposes with control over the resulting porosity, average pore diameter and mechanical properties. Five different biodegradable biocompatible polyphosphazenes exhibiting glass transition temperatures from ?8C to 41oC and poly(lactide-co-glycolide), (PLAGA) a degradable polymer used in a number of biomedical settings, were examined to study the versatility of the process and benchmark the process to heat sintering. Parameters such as: solvent/non-solvent sintering solution composition and submersion time effect the sintering process. PLAGA microsphere scaffolds fabricated with solvent/non-solvent sintering exhibited an interconnected porosity and pore size of 31.9% and 179.1m respectively which was analogous to that of conventional heat sintered PLAGA microsphere scaffolds. Biodegradable polyphosphazene microsphere scaffolds exhibited a maximum interconnected porosity of 37.6% and a maximum compressive modulus of 94.3MPa. Solvent/non-solvent sintering is an effective strategy for sintering polymeric microspheres, with a broad spectrum of glass transition temperatures, under ambient conditions making it an excellent fabrication route for developing tissue engineering scaffolds and drug delivery vehicles. PMID:18161819

Brown, Justin L.; Nair, Lakshmi S.; Laurencin, Cato T.

2009-01-01

301

Solvent stimulation of viscous crude-oil production. [Laboratory study of organic solvents to stimulate production  

Microsoft Academic Search

To improve both the rate and volume of production of viscous crude oils, the USBM made a study of solvents to stimulate production. Five laboratory methods were used to evaluate the effectiveness of several solvents in the stimulation of viscous oil production. These methods were (1) viscosity reduction, (2) gravity drainage production from sand columns, (3) displacement from capillary tubes,

G. L. Gates; W. H. Caraway

1971-01-01

302

Study of solvent-solvent interaction by paper chromatography II. Acetone Water system  

Microsoft Academic Search

Complex formation in acetone-water systems has been investigated by studying solvent migration rate and chromatographic behaviour of hexacyanoferrate (II) and (III). The formation of mono-, tetra-, and decahydrates of acetone has been observed, of which the tetrahydrate, also observable by other physical properties of the solvent mixture, is the most stable.

S. K. Shukla

1973-01-01

303

Identical Quantum Particles and Weak Discernibility  

Microsoft Academic Search

Saunders has recently claimed that identical quantum particles with an anti-symmetric state (fermions) are weakly discernible objects, just like irreflexively related ordinary objects in situations with perfect symmetry (Blacks spheres, for example). Weakly\\u000a discernible objects have all their qualitative properties in common but nevertheless differ from each other by virtue of (a\\u000a generalized version of) Leibnizs principle, since they stand

Dennis Dieks; Marijn A. M. Versteegh

2008-01-01

304

Elastic scattering with weakly bound projectiles  

SciTech Connect

Possible effects of the break-up channel on the elastic scattering threshold anomaly has been investigated. We used the weakly bound 6,7Li nuclei, which is known to undergo break-up, as projectiles in order to study the elastic scattering on a 27Al target. In this contribution we present preliminary results of these experiments, which were analyzed in terms of the Optical Model and compared with other elastic scattering data using weakly bound nuclei as projectile.

Figueira, J. M. [Laboratorio TANDAR, Comision Nacional de Energia Atomica, Av. General Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Departamento de Fisica, FCEyN, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, 1428 Buenos Aires (Argentina); Abriola, D.; Arazi, A.; Capurro, O. A.; Marti, G. V.; Martinez Heinmann, D.; Pacheco, A. J.; Testoni, J. E.; Barbara, E. de [Laboratorio TANDAR, Comision Nacional de Energia Atomica, Av. General Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Fernandez Niello, J. O. [Laboratorio TANDAR, Comision Nacional de Energia Atomica, Av. General Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad Nacional de General San Martin, Martin de Irigoyen 3100, 1650 San Martin, Buenos Aires (Argentina); Padron, I.; Gomes, P. R. S.; Lubian, J. [Instituto de Fisica, Universidade Federal Fluminense, Avenida Litoranea s/n, Gragoata, Niteroi, R. J., 24210-340 (Brazil)

2007-02-12

305

Weak identities, phantom maps and H -spaces  

Microsoft Academic Search

For a pointed spaceX, let Aut(X) be the group of pointed homotopy classes of pointed self-homotopy equivalences ofX and let WI(X) be the normal subgroup of Aut(X) consisting of weak identities, that is, elements represented by maps weakly homotopic to the identity map. IfX is a path-connected CW-space satisfying certain finiteness conditions, then the author has shown elsewhere that the

Joseph Roitberg

1989-01-01

306

Deterministic implementation of weak quantum cubic nonlinearity  

SciTech Connect

We propose a deterministic implementation of weak cubic nonlinearity, which is a basic building block of a full-scale continuous-variable quantum computation. Our proposal relies on preparation of a specific ancillary state and transferring its nonlinear properties onto the desired target by means of deterministic Gaussian operations and feed forward. We show that, despite the imperfections arising from the deterministic nature of the operation, the weak quantum nonlinearity can be implemented and verified with the current level of technology.

Marek, Petr; Filip, Radim; Furusawa, Akira [Department of Optics, Palacky University, 17. listopadu 1192/12, CZ-771 46 Olomouc (Czech Republic); Department of Applied Physics, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2011-11-15

307

Non-aqueous cleaning solvent substitution  

SciTech Connect

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 efforts to focus on finding alternative cleaning solvents and processes which are effective, environmentally safe, and compliant with local, state, and federal regulations. An alternative solvent has been identified, qualified, and implemented into production of complex electronic assemblies, where aqueous and semi-aqueous cleaning processes are not allowed. 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, 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. The electronics industry is constantly searching for proven methods and environmentally safe materials to use in manufacturing processes. The information in this presentation will provide another option to consider on future projects for applications requiring high levels of quality, reliability, and cleanliness from non-aqueous cleaning processes.

Meier, G.J.

1994-01-01

308

History as a coordination device  

Microsoft Academic Search

Coordination games often have multiple equilibria. The selection of equilibrium raises the question of belief formation: how\\u000a do players generate beliefs about the behavior of other players? This article takes the view that the answer lies in history,\\u000a that is, in the outcomes of similar coordination games played in the past, possibly by other players. We analyze a simple\\u000a model

Rossella Argenziano; Itzhak Gilboa

309

Effect of solvent properties on permeate flow through nanofiltration membranes. Part I: investigation of parameters affecting solvent flux  

Microsoft Academic Search

The objective of the present study was to characterize transport properties of solvents permeating through solvent resistant nanofiltration membranes that have only recently become available. Permeation flows of a number of solvents of different chemical families were measured in a batch cell. The solvents studied were alcohols, paraffins, ketones, acetates, and water, as well as their binary mixtures. The experimental

Dar??o R. Machado; David Hasson; Raphael Semiat

1999-01-01

310

40 CFR Table 3 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Default Organic HAP Mass Fraction for Solvents and Solvent Blends...Subpart IIII of Part 63Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the following...

2010-07-01

311

40 CFR Table 6 to Subpart Kkkk of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Default Organic HAP Mass Fraction for Solvents and Solvent Blends...Subpart KKKK of Part 63Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the following...

2010-07-01

312

40 CFR Table 3 to Subpart Rrrr of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Default Organic HAP Mass Fraction for Solvents and Solvent Blends...Subpart RRRR of Part 63Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the following...

2010-07-01

313

40 CFR Table 5 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Default Organic HAP Mass Fraction for Solvents and Solvent Blends...Subpart QQQQ of Part 63Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the following...

2010-07-01

314

40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Default Organic HAP Mass Fraction for Solvents and Solvent Blends...Subpart OOOO of Part 63Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the following...

2010-07-01

315

40 CFR Table 3 to Subpart Nnnn of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Default Organic HAP Mass Fraction for Solvents and Solvent Blends...Subpart NNNN of Part 63Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the following...

2010-07-01

316

40 CFR Table 3 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Default Organic HAP Mass Fraction for Solvents and Solvent Blends...Subpart MMMM of Part 63Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the following...

2010-07-01

317

40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true Default Organic HAP Mass Fraction for Solvents and Solvent Blends...Subpart PPPP of Part 63Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the following...

2010-07-01

318

Temporal coordination between performing musicians.  

PubMed

Many common behaviours require people to coordinate the timing of their actions with the timing of others' actions. We examined whether representations of musicians' actions are activated in coperformers with whom they must coordinate their actions in time and whether coperformers simulate each other's actions using their own motor systems during temporal coordination. Pianists performed right-hand melodies along with simple or complex left-hand accompaniments produced by themselves or by another pianist. Individual performers' preferred performance rates were measured in solo performance of the right-hand melody. The complexity of the left-hand accompaniment influenced the temporal grouping structure of the right-hand melody in the same way when it was performed by the self or by the duet partner, providing some support for the action corepresentation hypothesis. In contrast, accompaniment complexity had little influence on temporal coordination measures (asynchronies and cross-correlations between parts). Temporal coordination measures were influenced by a priori similarities between partners' preferred rates; partners who had similar preferred rates in solo performance were better synchronized and showed mutual adaptation to each other's timing during duet performances. These findings extend previous findings of action corepresentation and action simulation to a task that requires precise temporal coordination of independent yet simultaneous actions. PMID:21929475

Loehr, Janeen D; Palmer, Caroline

2011-11-01

319

Successful 'Green' Solvent Found For Problematic Chemicals  

NSDL National Science Digital Library

This week's In The News highlights the discovery of a new process that could separate problematic chemicals from ionic liquids. In industry, chemical reactions are performed in toxic organic solvents and some can form carbon dioxide and other greenhouse gases. Specifically, the vapor pressure of these organic solvents is hazardous because these "solvents evaporate easily into the air." The effects of such a reaction are that factory workers may inhale them and "the solvents add to damage of the earth's atmosphere, because organic solvents eventually will oxidize and create carbon dioxide, a greenhouse gas with potential impact on global warming". Published in the May 6, 1999 issue of Nature, scientists Joan Brennecke, Eric Beckman and other team members discuss how two "benign compounds together can perform certain chemical separations now done only by noxious organics." In the process discussed in Nature these scientists enforced supercritical (high pressure that causes liquid and gas to combine into one fluid phase) carbon dioxide into a solution of naphthalene (an organic chemical) dissolved in an ionic liquid (liquid salts at room temperature made of organic cations and inorganic anions). This pulled the naphthalene out with it while leaving behind the ionic liquid. As this mixture was depressurized, the "carbon dioxide returned to its gaseous form, leaving pure solid naphthalene." Ionic liquids and carbon dioxide are not considered perilous because ionic liquids do not evaporate and carbon dioxide is "considered to be an environmentally benign solvent because it is nontoxic and nonflammable and isn't being created in the process; what already exists is simply being used." Scientists Brennecke and Beckman believe this process could be useful for other chemicals. The ten resources listed provide news summaries, background information, and resources related to this recent discovery.

Nannapaneni, Sujani.

1999-01-01

320

47 CFR 80.513 - Frequency coordination.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Frequency coordination. 80.513 Section 80...Marine Utility Stations 80.513 Frequency coordination. (a) Except as...located in an area having a recognized frequency coordinating committee must be...

2011-10-01

321

47 CFR 80.513 - Frequency coordination.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Frequency coordination. 80.513 Section 80...Marine Utility Stations 80.513 Frequency coordination. (a) Except as...located in an area having a recognized frequency coordinating committee must be...

2012-10-01

322

47 CFR 80.513 - Frequency coordination.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Frequency coordination. 80.513 Section 80...Marine Utility Stations 80.513 Frequency coordination. (a) Except as...located in an area having a recognized frequency coordinating committee must be...

2010-10-01

323

47 CFR 80.513 - Frequency coordination.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Frequency coordination. 80.513 Section 80...Marine Utility Stations 80.513 Frequency coordination. (a) Except as...located in an area having a recognized frequency coordinating committee must be...

2013-10-01

324

28 CFR 42.412 - Coordination.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Coordination. 42.412 Section 42.412 ...OPPORTUNITY; POLICIES AND PROCEDURES Coordination of Enforcement of Non-discrimination...Federally Assisted Programs 42.412 Coordination. (a) The Attorney...

2011-07-01

325

49 CFR 214.325 - Train coordination.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Train coordination. 214.325 Section 214...Protection 214.325 Train coordination. Working limits established...worker through the use of train coordination shall comply with the...

2011-10-01

326

7 CFR 22.201 - Coordination.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Coordination. 22.201 Section 22.201...Agriculture RURAL DEVELOPMENT COORDINATION Roles and Responsibilities of Federal Government 22.201 Coordination. The following identifies...

2013-01-01

327

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

328

47 CFR 27.57 - International coordination.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false International coordination. 27.57 Section 27.57...Standards 27.57 International coordination. (a) WCS operations in the border areas shall be subject to coordination with those countries...

2013-10-01

329

47 CFR 27.903 - Coordination requirements.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Coordination requirements. 27.903 Section...1670-1675 MHz Band 27.903 Coordination requirements. (a) The licensee... (2) That requires international coordination; (3) That operates in areas...

2011-10-01

330

49 CFR 214.325 - Train coordination.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Train coordination. 214.325 Section 214...Protection 214.325 Train coordination. Working limits established...worker through the use of train coordination shall comply with the...

2012-10-01

331

47 CFR 27.57 - International coordination.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false International coordination. 27.57 Section 27.57...Standards 27.57 International coordination. (a) WCS operations in the border areas shall be subject to coordination with those countries...

2011-10-01

332

28 CFR 42.412 - Coordination.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Coordination. 42.412 Section 42.412 ...OPPORTUNITY; POLICIES AND PROCEDURES Coordination of Enforcement of Non-discrimination...Federally Assisted Programs 42.412 Coordination. (a) The Attorney...

2010-07-01

333

49 CFR 214.325 - Train coordination.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Train coordination. 214.325 Section 214...Protection 214.325 Train coordination. Working limits established...worker through the use of train coordination shall comply with the...

2010-10-01

334

47 CFR 27.903 - Coordination requirements.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Coordination requirements. 27.903 Section...1670-1675 MHz Band 27.903 Coordination requirements. (a) The licensee... (2) That requires international coordination; (3) That operates in areas...

2012-10-01

335

47 CFR 74.638 - Frequency coordination.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Frequency coordination. 74.638 Section 74.638 Telecommunication...Auxiliary Stations 74.638 Frequency coordination. (a) Coordination of all frequency assignments for...

2011-10-01

336

47 CFR 74.638 - Frequency coordination.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Frequency coordination. 74.638 Section 74.638 Telecommunication...Auxiliary Stations 74.638 Frequency coordination. (a) Coordination of all frequency assignments for...

2010-10-01

337

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

338

7 CFR 22.201 - Coordination.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Coordination. 22.201 Section 22.201...Agriculture RURAL DEVELOPMENT COORDINATION Roles and Responsibilities of Federal Government 22.201 Coordination. The following identifies...

2011-01-01

339

47 CFR 74.638 - Frequency coordination.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Frequency coordination. 74.638 Section 74.638 Telecommunication...Auxiliary Stations 74.638 Frequency coordination. (a) Coordination of all frequency assignments for...

2012-10-01

340

28 CFR 42.412 - Coordination.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Coordination. 42.412 Section 42.412 ...OPPORTUNITY; POLICIES AND PROCEDURES Coordination of Enforcement of Non-discrimination...Federally Assisted Programs 42.412 Coordination. (a) The Attorney...

2013-07-01

341

28 CFR 42.412 - Coordination.  

...2014-07-01 2014-07-01 false Coordination. 42.412 Section 42.412 ...OPPORTUNITY; POLICIES AND PROCEDURES Coordination of Enforcement of Non-discrimination...Federally Assisted Programs 42.412 Coordination. (a) The Attorney...

2014-07-01

342

7 CFR 22.201 - Coordination.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Coordination. 22.201 Section 22.201...Agriculture RURAL DEVELOPMENT COORDINATION Roles and Responsibilities of Federal Government 22.201 Coordination. The following identifies...

2012-01-01

343

47 CFR 74.638 - Frequency coordination.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Frequency coordination. 74.638 Section 74.638 Telecommunication...Auxiliary Stations 74.638 Frequency coordination. (a) Coordination of all frequency assignments for...

2013-10-01

344

36 CFR 72.48 - Federal coordination.  

... 2014-07-01 false Federal coordination. 72.48 Section 72.48 Parks...and Innovation 72.48 Federal coordination. Applicants requesting UPARR...possibilities of administrative and/or funding coordination with other Federal programs....

2014-07-01

345

49 CFR 214.325 - Train coordination.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Train coordination. 214.325 Section 214...Protection 214.325 Train coordination. Working limits established...worker through the use of train coordination shall comply with the...

2013-10-01

346

28 CFR 42.412 - Coordination.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Coordination. 42.412 Section 42.412 ...OPPORTUNITY; POLICIES AND PROCEDURES Coordination of Enforcement of Non-discrimination...Federally Assisted Programs 42.412 Coordination. (a) The Attorney...

2012-07-01

347

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

348

47 CFR 27.57 - International coordination.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false International coordination. 27.57 Section 27.57...Standards 27.57 International coordination. (a) WCS operations in the border areas shall be subject to coordination with those countries...

2012-10-01

349

7 CFR 22.201 - Coordination.  

...2014-01-01 2014-01-01 false Coordination. 22.201 Section 22.201...Agriculture RURAL DEVELOPMENT COORDINATION Roles and Responsibilities of Federal Government 22.201 Coordination. The following identifies...

2014-01-01

350

Investigation of aggregation in solvent extraction of lanthanides by acidic extractants (organophosphorus and naphthenic acid)  

USGS Publications Warehouse

Three acidic extractants (I) di(2-ethylhexyl) phosphoric acid (HDEHP), (II) 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (HEHPEHE) and (III) naphthenic acid were employed in preparing the samples for the characterization of the coordination structure of lanthanide-extractant complexes and the physicochemical nature of aggregates formed in the organic diluent of the solvent extraction systems. Photo correlation spectroscopy (PCS) results on the aggregates formed by the partially saponified HDEHP in n-heptane showed that the hydrodynamic radius of the aggregates was comparable to the molecular dimensions of HDEHP. The addition of 2-octanol into the diluent, by which the mixed solvent was formed, increased the dimensions of the corresponding aggregates. Aggregates formed from the lanthanide ions and HDEHP in the organic phase of the extraction systems were found very unstable. In the case of naphthenic acid, PCS data showed the formation of w/o microemulsion from the saponified naphthenic acid in the mixed solvent. The extraction of lanthanides by the saponified naphthenic acid in the mixed solvent under the given experimental conditions was a process of destruction of the w/o microemulsion. A possible mechanism of the breakdown of the w/o microemulsion droplets is discussed.

Zhou, N.; Wu, J.; Yu, Z.; Neuman, R. D.; Wang, D.; Xu, G.

1997-01-01

351

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

352

The Borexino scintillator and solvent procurement  

NASA Astrophysics Data System (ADS)

The Borexino experiment for solar neutrino physics and other rare phenomena requires an extremely low radioactive background to disentangle the very few events due to neutrino interactions. Therefore, the Borexino scintillator has to satisfy the most stringent radiopurity requirements, being about eight orders of magnitude less radioactive than an ordinary material. This was achieved by means of scintillator purification techniques and of a special care during all the production, handling and procurement of the scintillator solvent. This paper describes the methodology and the quality control procedures that were employed during the production, handling and shipping of the solvent.

Giammarchi, Marco

2014-05-01

353

Solvent-resistant microporous polymide membranes  

DOEpatents

An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

Miller, Warren K. (Bend, OR); McCray, Scott B. (Bend, OR); Friesen, Dwayne T. (Bend, OR)

1998-01-01

354

Solvent-resistant microporous polymide membranes  

DOEpatents

An asymmetric microporous membrane with exceptional solvent resistance and highly desirable permeability is disclosed. The membrane is made by a solution-casting or solution-spinning process from a copolyamic acid comprising the condensation reaction product in a solvent of at least three reactants selected from certain diamines and dianhydrides and post-treated to imidize and in some cases cross-link the copolyamic acid. The membrane is useful as an uncoated membrane for ultrafiltration, microfiltration, and membrane contactor applications, or may be used as a support for a permselective coating to form a composite membrane useful in gas separations, reverse osmosis, nanofiltration, pervaporation, or vapor permeation.

Miller, W.K.; McCray, S.B.; Friesen, D.T.

1998-03-10

355

Solvent tunable optical properties of a polymerized vinyl- and thienyl-substituted ionic liquid.  

SciTech Connect

Thermal free radical polymerization of a self-assembled, bifunctional imidazolium-based ionic liquid (IL) monomer bearing both vinyl and thienyl groups is reported. FT-IR spectroscopy proves that the polymerization occurs through both the vinyl and thienyl groups. The polymer is resistant to swelling in water and common organic solvents. The as-synthesized polymer can be readily chemically doped and de-doped. Small-angle X-ray scattering studies indicate that the dried polymer adopts a weakly ordered lamellar structure. The p-doped, ethanol-solvated polymer undergoes a structural conversion to a nonlamellar phase. The absorption and photoluminescence spectra can be modulated in both the neutral (thiophene) and p-doped states depending on whether the polymer is dry or ethanol-solvated. The results demonstrate the possibility of incorporating solvent responsive optical characteristics in a {pi}-conjugated polymer.

Becht, G. A.; Lee, S.; Seifert, S.; Firestone, M. A.

2010-09-16

356

Influence of solvents on the kinetics of the reaction of benzyl chloride with methacrylic acid in the presence of tertiary amines  

Microsoft Academic Search

1.The direction of the reaction of benzyl chloride with methacrylic acid in the presence of tertiary amines depends on the basicity of the amine. In the presence of highly basic amines, benzyl methacrylate is formed. Weakly basic amines are alkylated by benzyl chloride.2.Aprotonic polar solvents accelerate the formation of the ester. The reaction rate constant correlates with the dielectric constant

K. A. Charushnikov; M. A. Bulatov; L. G. Surovtsev

1980-01-01

357

Promoting Coordination for Disaster Relief - From Crowdsourcing to Coordination  

NASA Astrophysics Data System (ADS)

The efficiency at which governments and non-governmental organizations (NGOs) are able to respond to a crisis and provide relief to victims has gained increased attention. This emphasis coincides with significant events such as tsunamis, hurricanes, earthquakes, and environmental disasters occuring during the last decade. Crowdsourcing applications such as Twitter, Ushahidi, and Sahana have proven useful for gathering information about a crisis yet have limited utility for response coordination. In this paper, we briefly describe the shortfalls of current crowdsourcing applications applied to disaster relief coordination and discuss one approach aimed at facilitating efficient collaborations amongst disparate organizations responding to a crisis.

Gao, Huiji; Wang, Xufei; Barbier, Geoffrey; Liu, Huan

358

Low-overhead distributed transaction coordination  

E-print Network

This thesis presents Granola, a transaction coordination infrastructure for building reliable distributed storage applications. Granola provides a strong consistency model, while significantly reducing transaction coordination ...

Cowling, James (James Alexander)

2012-01-01

359

Solvent-mediated vibrational energy relaxation from Vaska's complex adducts in binary solvent mixtures.  

PubMed

A vibrational pump-probe and FTIR study was performed on two different adducts of Vaska's complex in two different sets of binary solvent mixtures. The carbonyl vibrational mode in the oxygen adduct exhibits solvatochromic shifts of ~10 cm(-1) in either benzyl alcohol or chloroform relative to benzene-d6, whereas this vibration is nearly unchanged for the iodine adduct for the same three solvents. The width and center frequency of the carbonyl stretch for each adduct are compared to its vibrational lifetime in binary mixtures of benzene-d6 with either benzyl alcohol or chloroform. In neat solvents, the trends in line width, frequency, and vibrational lifetime are consistent for the two adducts, but complex relationships emerge when the trends in each property are compared as a function of mixed solvent composition. ?(CO) is more sensitive to the solvation environment around the trans ligand, whereas the line width and lifetime depend on the environment around the CO group itself. The carbonyl frequency and width vary nonlinearly across the two binary solvent series, indicating preferential solvation. In contrast, the vibrational lifetime changes linearly with solvent composition and is correlated with the mole fraction of chloroform but anticorrelated with the mole fraction of benzyl alcohol. The results are explained by differences in the densities of solvent modes that affect intermolecular relaxation of the carbonyl mode. PMID:23531048

Jones, Brynna H; Huber, Christopher J; Massari, Aaron M

2013-07-25

360

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. PMID:18814299

Labute, Paul

2009-01-01

361

Explaining numeracy development in weak performing kindergartners.  

PubMed

Gaining better insight into precursors of early numeracy in young children is important, especially in those with inadequate numeracy skills. Therefore, in the current study, visual and verbal working memory, non-symbolic and symbolic comparison skills, and specific math-related language were used to explain early numeracy performance and development of weak performing children throughout kindergarten. The early numeracy ability of both weak performers and typical performers was measured at four time points during 2 years of kindergarten to compare growth rates. Results show a significant faster development of early numeracy in the weak performers. The development of weak performers' numeracy was influenced by verbal working memory, symbolic comparison skills, and math language, whereas only math language was positively related to the slope of typical performers' numeracy. In the weak performers, visual working memory, non-symbolic comparison skills, and math language showed an effect on the initial early numeracy level of these children. The intercept of the typical performers was predicted by five covariates, all except non-symbolic comparison. PMID:24786672

Toll, Sylke W M; Van Luit, Johannes E H

2014-08-01

362

Is there muscular weakness in Parkinson's disease?  

PubMed

Controversy exists as to whether muscle weakness is present in Parkinson's disease (PD). Computerized literature searches identified clinical trials and reviews about muscular strength assessment in patients with Parkinson's disease, using the following databases: PubMed, Ovid MEDLINE, Ovid EMBASE, the Cochrane Database of Systematic Reviews, Cumulative Index to Nursing and Allied Health Literature, and Physiotherapy Evidence Database. Seventeen articles fulfilled all criteria for selection. These studies suggested that isokinetic muscle strength was decreased in patients with Parkinson's disease and that muscle weakness was not specifically related to tremor or rigidity. Bilateral asymmetrical muscle weakness was present in Parkinson's disease when presenting with clinical unilateral hemiparkinsonism. Recent studies using sensitive mechanical devices have provided evidence that muscle strength is reduced in patients with Parkinson's disease compared with age-matched controls. The specific cause of this weakness is not known. Questions under debate were whether this weakness was of central or peripheral origin and whether it was intrinsic to the disease or a secondary phenomenon. PMID:19487924

Cano-de-la-Cuerda, Roberto; Prez-de-Heredia, Marta; Miangolarra-Page, Juan Carlos; Muoz-Helln, Elena; Fernndez-de-Las-Peas, Cesar

2010-01-01

363

30 years of weak neutral currents  

NASA Astrophysics Data System (ADS)

We trace the early history of Neutral and Charged Weak Current studies from the 1930's to the discovery of the W and Z in 1983. The period from approximately 1963 to 1983 saw a great advance in our knowledge of Weak Neutral Currents; the first search for Flavor Changing Weak Neutral Currents (FCNC) in 1963, the discovery of Weak Neutral Currents (WNC) in 1973, as well as the rise of the Standard Model (1974-1978) and the discovery of the (W,Z) in 1983! This report follows an International Symposium on 30 Years of Neutral Currents from Weak Neutral Currents to the (W)/Z and Beyond held in Santa Monica, California, on February 3-5, 1993. Neutral Currents (NC) are important in Supernova explosions and the Early Universe. Recently, the bold speculation has been made that NC can give rise to the chirality of life (DNA). We briefly discuss the pro's and con's of this idea and present some recent simulation results.

Cline, David B.

1994-06-01

364

Generalized spherical and simplicial coordinates  

NASA Astrophysics Data System (ADS)

Elementary trigonometric quantities are defined in l2,p analogously to that in l2,2, the sine and cosine functions are generalized for each p>0 as functions sinp and cosp such that they satisfy the basic equation cosp([phi])p+sinp([phi])p=1. The p-generalized radius coordinate of a point [xi][set membership, variant]Rn is defined for each p>0 as . On combining these quantities, ln,p-spherical coordinates are defined. It is shown that these coordinates are nearly related to ln,p-simplicial coordinates. The Jacobians of these generalized coordinate transformations are derived. Applications and interpretations from analysis deal especially with the definition of a generalized surface content on ln,p-spheres which is nearly related to a modified co-area formula and an extension of Cavalieri's and Torricelli's indivisibeln method, and with differential equations. Applications from probability theory deal especially with a geometric interpretation of the uniform probability distribution on the ln,p-sphere and with the derivation of certain generalized statistical distributions.

Richter, Wolf-Dieter

2007-12-01

365

Developmental Co-Ordination Disorder (DCD) in Adolescents and Adults in Further and Higher Education  

ERIC Educational Resources Information Center

Few studies have looked at the strengths and weaknesses and needs of students with developmental co-ordination disorder (DCD). This paper describes a cohort of 93 UK students currently studying at further or higher education and who have reported motor difficulties present since childhood. The study group consisted of 21 reporting to have DCD

Kirby, Amanda; Sugden, David; Beveridge, Sally; Edwards, Lisa

2008-01-01

366

DEGRADED TBP SOLVENT REGENERATION TECHNOLOGY USING BUTYLAMINE AS A SOLVENT WASHING TO REDUCE SOLID SALT WASTE  

SciTech Connect

Normal butylamine compounds are studied as salt-free wash reagents for degraded solvent used in PUREX process in spent fuel reprocessing. The solvent wash tests were carried out with two types of butylamine compounds, n-butylamine oxalate and n-butylamine bicarbonate, by counter-current mode using a small size mixer-settler composed of two 4-stage wash steps. Di-n-butyl phosphoric acid (HDBP), the main degradation product from TBP, was removed from real degraded solvent with decontamination factor of 2.5 {approx} 7.9. The study on electrolytic decomposition of butylamine compounds was also conducted for waste treatment.

Asakura, T.; Itoh, Y.; Hotoku, S.; Morita, Y.; Uchiyama, G.

2003-02-27

367

Solvent-Free Synthesis of Chalcones  

ERIC Educational Resources Information Center

The synthesis of twenty different chalcones in the absence of solvent is presented. The results indicated that out of the twenty different chalcones investigated seventeen can be obtained in a matter of minutes by mixing the corresponding benzaldehyde and acetophenone in the presence of solid NaOH in a mortar with pestle.

Palleros, Daniel R.

2004-01-01

368

REPLACING SOLVENT CLEANING WITH AQUEOUS CLEANING  

EPA Science Inventory

The report documents actions taken by Robert Bosch Corp., Charleston, SC, in replacing the cleaning solvents 1, 1, 2- trichloro-1, 2, 2-trifluoroethane (CFC-113) and trichloroethylene (TCE) with aqueous solutions. osch has succeeded in eliminating all their CFC-113 use and so far...

369

REPLACING SOLVENT CLEANING WITH AQUEOUS CLEANING  

EPA Science Inventory

The report documents actions taken by Robert Bosch Corp., Charleston, SC, in replacing the cleaning solvents 1, 1, 2- trichloro-1, 2, 2-trifluoroethane (CFC-113) and trichloroethylene (TCE) with aqueous solutions. Bosch has succeeded in eliminating all their CFC-113 use and so f...

370

Crystal growth in fused solvent systems  

NASA Technical Reports Server (NTRS)

Research is reported on the growth of electronic ceramic single crystals from solution for the future growth of crystals in a microgravity environment. Work included growth from fused or glass solvents and aqueous solutions. Topics discussed include: crystal identification and selection; aqueous solution growth of triglycine sulphate (TGS); and characterization of TGS.

Ulrich, D. R.; Noone, M. J.; Spear, K. E.; White, W. B.; Henry, E. C.

1973-01-01

371

SOLVENT FREE CHEMICAL TRANSFORMATION USING MICROWAVE IRRADIATION  

EPA Science Inventory

Microwave-expedited solvent-free synthetic processes will be described that involve the exposure of neat reactants to microwave (MW) irradiation in the presence of supported reagents or catalysts on mineral oxides. Recent developments will be presented on the synthetic utility o...

372

Integrated array sensor for detecting organic solvents  

Microsoft Academic Search

A new sensor array device has been designed to detect organic solvents; it comprises an array of six interdigital sensors lying upon a micromachined 0.5 ?m thick silicon nitride membrane. There are three separate micromachined cells with two sensors per cell. In each cell, a thin film platinum resistance thermometer\\/heater is sandwiched in the middle of the silicon nitride layer

J. W. Gardner; A. Pike; N. F. de Rooij; M. Koudelka-Hep; P. A. Clerc; A. Hierlemann; W. Gpel

1995-01-01

373

CO-SOLVENT BASED SOURCE REMEDIATION APPROACHES  

EPA Science Inventory

Field pilot scale studies have demonstrated that co-solvent-enhanced in situ extraction can remove residual and free-phase nonaqueous phase liquid (NAPL), but may leave levels of contaminants in the ground water and subsurface formation higher than regulatory requirements for c...

374

Solvent abuse, toluene acidosis and diabetic ketoacidosis.  

PubMed

Solvent abuse in adolescents and young adults has been reported to cause a metabolic acidosis with a normal or increased anion gap (Streicher et al., 1981; Voights & Kaufman, 1983, Anonymous, 1988). We report a particularly severe clinical problem produced by the combination of toluene intoxication and diabetic ketoacidosis. PMID:1906715

Brown, J H; Hadden, D R; Hadden, D S

1991-03-01

375

Revealed Quantum Information in Weak Interaction Processes  

E-print Network

We analyze the achievable limits of the quantum information processing of the weak interaction revealed by hyperons with spin. We find that the weak decay process corresponds to an interferometric device with a fixed visibility and fixed phase difference for each hyperon. Nature chooses rather low visibilities expressing a preference to parity conserving or violating processes (except for the decay $\\Sigma^+\\longrightarrow p \\pi^0$). The decay process can be considered as an open quantum channel that carries the information of the hyperon spin to the angular distribution of the momentum of the daughter particles. We find a simple geometrical information theoretic interpretation of this process: two quantization axes are chosen spontaneously with probabilities $\\frac{1\\pm\\alpha}{2}$ where $\\alpha$ is proportional to the visibility times the real part of the phase shift. Differently stated the weak interaction process corresponds to spin measurements with an imperfect Stern-Gerlach apparatus. Equipped with this...

Hiesmayr, B C

2014-01-01

376

Strong effects in weak nonleptonic decays  

SciTech Connect

In this report the weak nonleptonic decays of kaons and hyperons are examined with the hope of gaining insight into a recently proposed mechanism for the ..delta..I = 1/2 rule. The effective Hamiltonian for ..delta..S = 1 weak nonleptonic decays and that for K/sup 0/-anti K/sup 0/ mixing are calculated in the six-quark model using the leading logarithmic approximation. These are used to examine the CP violation parameters of the kaon system. It is found that if Penguin-type diagrams make important contributions to K ..-->.. ..pi pi.. decay amplitudes then upcoming experiments may be able to distinguish the six-quark model for CP violation from the superweak model. The weak radiative decays of hyperons are discussed with an emphasis on what they can teach us about hyperon nonleptonic decays and the ..delta..I = 1/2 rule.

Wise, M.B.

1980-04-01

377

Incorporation of the TIP4P water model into a continuum solvent for computing solvation free energy  

NASA Astrophysics Data System (ADS)

The continuum solvent model is one of the commonly used strategies to compute solvation free energy especially for large-scale conformational transitions such as protein folding or to calculate the binding affinity of protein-protein/ligand interactions. However, the dielectric polarization for computing solvation free energy from the continuum solvent is different than that obtained from molecular dynamic simulations. To mimic the dielectric polarization surrounding a solute in molecular dynamic simulations, the first-shell water molecules was modeled using a charge distribution of TIP4P in a hard sphere; the time-averaged charge distribution from the first-shell water molecules were estimated based on the coordination number of the solute, and the orientation distribution of the first-shell waters and the intermediate water molecules were treated as that of a bulk solvent. Based on this strategy, an equation describing the solvation free energy of ions was derived.

Yang, Pei-Kun

2014-10-01

378

Polysiloxane ionic liquids as good solvents for ?-cyclodextrin-polydimethylsiloxane polyrotaxane structures.  

PubMed

An ionic liquid based on polydimethylsiloxane with imidazolium salt brushes was synthesized as a good solvent for ?-cyclodextrin-polydimethylsiloxane rotaxane. As expected the PDMS-Im/Br ionic liquid had a liquid-like non-Newtonian behavior with rheological parameters dependent on frequency and temperature. The addition of rotaxane to the ionic liquid strengthened the non-Newtonian character of the sample and a type of stable liquid-like network was formed due to the contribution of weak ionic interactions. The structure is stable in the 20 to 80 C domain as proved by the oscillatory and rotational rheological tests. PMID:23209493

Marangoci, Narcisa; Ardeleanu, Rodinel; Ursu, Laura; Ibanescu, Constanta; Danu, Maricel; Pinteala, Mariana; Simionescu, Bogdan C

2012-01-01

379

Polysiloxane ionic liquids as good solvents for ?-cyclodextrin-polydimethylsiloxane polyrotaxane structures  

PubMed Central

Summary An ionic liquid based on polydimethylsiloxane with imidazolium salt brushes was synthesized as a good solvent for ?-cyclodextrin-polydimethylsiloxane rotaxane. As expected the PDMS-Im/Br ionic liquid had a liquid-like non-Newtonian behavior with rheological parameters dependent on frequency and temperature. The addition of rotaxane to the ionic liquid strengthened the non-Newtonian character of the sample and a type of stable liquid-like network was formed due to the contribution of weak ionic interactions. The structure is stable in the 20 to 80 C domain as proved by the oscillatory and rotational rheological tests. PMID:23209493

Marangoci, Narcisa; Ardeleanu, Rodinel; Ursu, Laura; Ibanescu, Constanta; Danu, Maricel; Simionescu, Bogdan C

2012-01-01

380

Extrapolating Weak Selection in Evolutionary Games  

PubMed Central

In evolutionary games, reproductive success is determined by payoffs. Weak selection means that even large differences in game outcomes translate into small fitness differences. Many results have been derived using weak selection approximations, in which perturbation analysis facilitates the derivation of analytical results. Here, we ask whether results derived under weak selection are also qualitatively valid for intermediate and strong selection. By qualitatively valid we mean that the ranking of strategies induced by an evolutionary process does not change when the intensity of selection increases. For two-strategy games, we show that the ranking obtained under weak selection cannot be carried over to higher selection intensity if the number of players exceeds two. For games with three (or more) strategies, previous examples for multiplayer games have shown that the ranking of strategies can change with the intensity of selection. In particular, rank changes imply that the most abundant strategy at one intensity of selection can become the least abundant for another. We show that this applies already to pairwise interactions for a broad class of evolutionary processes. Even when both weak and strong selection limits lead to consistent predictions, rank changes can occur for intermediate intensities of selection. To analyze how common such games are, we show numerically that for randomly drawn two-player games with three or more strategies, rank changes frequently occur and their likelihood increases rapidly with the number of strategies . In particular, rank changes are almost certain for , which jeopardizes the predictive power of results derived for weak selection. PMID:24339769

Wu, Bin; Garcia, Julian; Hauert, Christoph; Traulsen, Arne

2013-01-01

381

A study of a solvent extraction desalination process  

E-print Network

of possible solvents were carefully evaluated, secondary and tertiary amines of 5 and 6 total carbon atoms were found to have by far the best solvent properties (9, 10, 26). In the developed process, the amine solvent extracts water selectively from salt... of possible solvents were carefully evaluated, secondary and tertiary amines of 5 and 6 total carbon atoms were found to have by far the best solvent properties (9, 10, 26). In the developed process, the amine solvent extracts water selectively from salt...

McFerrin, Arthur Ransom

2012-06-07

382

Gas separation by composite solvent-swollen membranes  

DOEpatents

There is disclosed a composite immobulized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorous or sulfur atom, and having a boiling point of at least 100.degree. C. and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation.

Matson, Stephen L. (Harvard, MA); Lee, Eric K. L. (Acton, MA); Friesen, Dwayne T. (Bend, OR); Kelly, Donald J. (Bend, OR)

1989-01-01

383

Measuring motor coordination in mice.  

PubMed

Mice are increasingly being used in behavioral neuroscience, largely replacing rats as the behaviorist's animal of choice. Before aspects of behavior such as emotionality or cognition can be assessed, however, it is vital to determine whether the motor capabilities of e.g. a mutant or lesioned mouse allow such an assessment. Performance on a maze task requiring strength and coordination, such as the Morris water maze, might well be impaired in a mouse by motor, rather than cognitive, impairments, so it is essential to selectively dissect the latter from the former. For example, sensorimotor impairments caused by NMDA antagonists have been shown to impair water maze performance(2). Motor coordination has traditionally been assessed in mice and rats by the rotarod test, in which the animal is placed on a horizontal rod that rotates about its long axis; the animal must walk forwards to remain upright and not fall off. Both set speed and accelerating versions of the rotarod are available. The other three tests described in this article (horizontal bar, static rods and parallel bars) all measure coordination on static apparatus. The horizontal bar also requires strength for adequate performance, particularly of the forelimbs as the mouse initially grips the bar just with the front paws. Adult rats do not perform well on tests such as the static rods and parallel bars (personal observations); they appear less well coordinated than mice. I have only tested male rats, however, and male mice seem generally less well coordinated than females. Mice appear to have a higher strength:weight ratio than rats; the Latin name, Mus musculus, seems entirely appropriate. The rotarod, the variations of the foot fault test(12) or the Catwalk (Noldus)(15) apparatus are generally used to assess motor coordination in rats. PMID:23748408

Deacon, Robert M J

2013-01-01

384

Weak cloning of an unknown quantum state  

E-print Network

The impossibility to clone an unknown quantum state is a powerful principle to understand the nature of quantum mechanics, especially within the context of quantum computing and quantum information. This principle has been generalized to quantitative statements as to what extent imperfect cloning is possible. We delineate an aspect of the border between the possible and the impossible concerning quantum cloning, by putting forward an entanglement-assisted scheme for simulating perfect cloning in the context of weak measurements. This phenomenon we call weak cloning of an unknown quantum state.

Erik Sjqvist; Johan berg

2005-06-15

385

Reactions with Weakly Bound Cluster Nuclei  

NASA Astrophysics Data System (ADS)

Experimental excitation functions are presented for complete fusion and transfer reactions in the interaction of 6He and 6,7,9Li with different targets. In the case of the interaction of weakly bound nuclei the fusion process is more complex character due to the likely higher probability of the nuclei to breakup with subsequent capture of the residual nucleus (incomplete fusion). This greatly complicates the description of the interaction of such systems and leads to new unexpected effects at energies near the Coulomb barrier deeply subbarrier fusion and transfer of clusters from the weakly bound nuclei which are usually characterized by cluster structure.

Penionzhkevich, Yu. E.

2011-10-01

386

Hall Magnetohydrodynamics of weakly-ionized plasma  

E-print Network

We show that the Hall scale in a weakly ionized plasma depends on the fractional ionization of the medium and, Hall MHD description becomes important whenever the ion-neutral collision frequency is comparable to the ion-gyration frequency, or, the ion-neutral collisional mean free path is smaller than the ion gyro-radius. Wave properties of a weakly-ionized plasma also depends on the fractional ionization and plasma Hall parameters, and whistler mode is the most dominant mode in such a medium. Thus Hall MHD description will be important in astrophysical disks, dark molecular clouds, neutron star crusts, and, solar and planetary atmosphere.

B. P. Pandey; Mark Wardle

2006-08-01

387

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.

Bhuvnesh Jain

2006-02-27

388

Weak decay of hypernuclei - Theoretical status  

E-print Network

The physics of the weak decay of hypernuclei is briefly reviewed from a theoretical point of view. Special regard is devoted to the recent progress concerning the determination of the non--mesonic decay widths and the asymmetry parameters. While convincing evidence has been achieved for a solution of the long-standing puzzle on the ratio Gamma_n/Gamma_p, the discrepancies between theory and experiment on the decay asymmetries clearly highlight the exigence of dedicating further efforts in exploring new aspects of the dynamics underlying the non-mesonic weak decay.

G. Garbarino

2007-01-17

389

Solvent effect on anthranilic acid spectroscopy.  

PubMed

The spectroscopy of anthranilic acid (AA) was examined in neat and binary solvents of varying polarity and hydrogen bonding strength in order to understand the role of water in solvating the polar sites of the molecule. With the exception of water, the Stokes shift of AA in different solvents was found to be linearly correlated with the normalized molar transition energy of solvent polarity (ETN), indicating the major role of the hydrogen bonding effect in solution. Analysis of the absorption and fluorescence spectra reveals that AA exists as an anion in neutral water. The pKa (4.50) and pKa* (4.44) values were estimated from the spectral shift in the absorption and fluorescence spectra measured in different pH solutions. The shortest fluorescence lifetime was measured in cyclohexane and is attributed to intramolecular hydrogen dislocation/transfer in the excited state. The lifetime values in polar solvents point to the dominant effect of the hydrogen-bond donating strength (? value) of the solvent. The number of water molecules solvating the polar region of the neutral form of AA was estimated to be three from the absorbance change in dioxane/buffer (pH 3.5) binary mixtures. The structures of AA:water complexes were calculated from density functional theory using the B3LYP method with a 6-311++G(2d,p) basis set. A stepwise addition of water molecules (13) to the polar region of AA leads to a preferential solvation of the COOH group of the molecule in a closed-cyclic geometry. It is worth noting that the spectral shift as a function of pH suggests the suitability of AA as a probe to estimate the local acidity of binding sites in macromolecules in the pH range 3.07.0. PMID:24102373

Abou-Zied, Osama K; Al-Busaidi, Badriya Y; Husband, John

2014-01-01

390

Weakly chiral networks and two-dimensional delocalized states in a weak magnetic field  

Microsoft Academic Search

We study numerically the localization properties of two-dimensional electrons in a weak perpendicular magnetic field. For this purpose we construct weakly chiral network models on the square and triangular lattices. The prime idea is to separate in space the regions with phase action of magnetic field, where it affects interference in course of multiple disorder scattering, and the regions with

V. V. Mkhitaryan; V. Kagalovsky; M. E. Raikh

2010-01-01

391

Toroidal condensates of semiflexible polymers in poor solvents: adsorption, stretching, and compression.  

PubMed Central

When a semiflexible polymer chain is placed in a poor solvent, or in the presence of condensing agents, a toroidal condensate can result. In typical experiments, these condensates are adsorbed to surfaces. Here we examine the changes that can occur when a toroid is adsorbed. We then examine the behavior of a toroid when stretched and identify two regimes: a weak stretching regime where the toroid deforms from a circle to an ellipse, and a strong stretching regime where a tether is pulled from the toroid. In the weak stretching regime, the force increases linearly with separation whereas in the strong stretching regime, the applied force is a constant. We then look at the case of a toroid compressed in the plane of the toroid. In this case the form of the force law depends on how strongly the toroid wets the surfaces. In general, an inverse square force law is found. PMID:11159392

Pereira, G G; Williams, D R

2001-01-01

392

Effect of solvent on the excited-state photophysical properties of curcumin.  

PubMed

Photophysical properties of curcumin, 1,7-bis-(4-hydroxy-3-methoxy phenyl)-1,6-heptadiene-2,5-dione, a pigment found in the rhizomes of Curcuma longa (turmeric) have been studied in different kinds of organic solvent and also in Triton X-100 aqueous micellar media using time-resolved fluorescence and transient absorption techniques having pico and nanosecond time resolution, in addition to steady-state absorption and fluorescence spectroscopic techniques. Steady-state absorption and fluorescence characteristics of curcumin have been found to be sensitive to the solvent characteristics. Large change (delta mu = 6.1 Debye) in dipole moments due to photoexcitation to the excited singlet state (S1) indicates strong intramolecular charge transfer character of the latter. Curcumin is a weakly fluorescent molecule and the fluorescence decay properties in most of the solvents could be fitted well to a double-exponential decay function. The shorter component having lifetime in the range 50-350 ps and percent contribution of amplitude more than 90% in different solvents may be assigned to the enol form, whereas the longer component, having lifetime in the range 500-1180 ps with less than 10% contribution may be assigned to the di-keto form of curcumin. Our nuclear magnetic resonance study in CDCl3 and dimethyl sulfoxide-D6 also supports the fact that the enol form is present in the solution by more than about 95% in these solvents. Excited singlet (S1) and triplet (T1) absorption spectrum and decay kinetics have been characterized by pico and nanosecond laser flash photolysis. Quantum yield of the triplet is low (phi T < or = 0.12). Both the fluorescence and triplet quantum yields being low (phi f + phi T < 0.18), the photophysics of curcumin is dominated by the energy relaxation mechanism via the internal conversion process. PMID:11107847

Khopde, S M; Priyadarsini, K I; Palit, D K; Mukherjee, T

2000-11-01

393

Highly concentrated graphene solutions via polymer enhanced solvent exfoliation and iterative solvent exchange.  

PubMed

Efficient graphene exfoliation in a nontraditional solvent, ethanol, is achieved through the addition of a stabilizing polymer, ethyl cellulose. Iterative solvent exchange is further demonstrated as a rapid, room-temperature, ultracentrifugation-free approach to concentrate the graphene solution to a level exceeding 1 mg/mL. The outstanding processability and electrical properties of these graphene inks are verified through the realization of aligned graphene-polymer nanocomposites and transparent conductive graphene thin films. PMID:21114312

Liang, Yu Teng; Hersam, Mark C

2010-12-22

394

Interaction forces between asphaltene surfaces in organic solvents.  

PubMed

The colloidal interactions between asphaltene surfaces in heptol, a mixture of n-heptane and toluene, were studied for the first time by colloidal force measurements using an atomic force microscope (AFM). Asphaltenes were deposited on silica wafers and silica spheres using the Langmuir-Blodgett upstroke technique. The results showed that the ratio of toluene to heptane can significantly change solvent quality in terms of the ability to solubilize asphaltenes and hence the nature and the magnitude of the interaction forces between asphaltene surfaces. In pure toluene, there is a steric long-range repulsion which can be well fitted by the scaling theory of polymer brushes. As toluene volume fraction in heptol (Phi(T)) is gradually decreased from Phi(T) = 1 (pure toluene) to Phi(T) = 0 (pure n-heptane), the steric repulsion reduced and changed to weak attraction when Phi(T) < 0.2. The attraction in heptane can be fitted by van der Waals forces alone which are thus believed to promote asphaltene aggregation, leading to asphaltene precipitation. The results obtained in this study provide an insight into interactions that determine asphaltene behavior in an organic medium and hence in crude oils. PMID:19645456

Wang, Shengqun; Liu, Jianjun; Zhang, Liyan; Masliyah, Jacob; Xu, Zhenghe

2010-01-01

395

Discovery of exceptionally efficient catalysts for solvent-free enantioselective hetero-Diels-Alder reaction.  

PubMed

Combinatorial coordination chemistry strategy combined with high-throughput screening techniques has been successfully applied to engineering practical enantioselective catalysts for asymmetric hetero-Diels-Alder reaction. The reaction of Danishefsky's diene with a variety of aldehydes can be carried out with 0.1-0.005 mol % of H4-BINOL/Ti/H4-BINOL or H4-BINOL/Ti/H8-BINOL catalysts at room temperature under solvent- and MS-free conditions to afford dihydropyrone derivatives with up to quantitative yield and 99.8% ee. PMID:11772048

Long, Jiang; Hu, Jieyu; Shen, Xiaoqiang; Ji, Baoming; Ding, Kuiling

2002-01-01

396

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

397

Communication and Coordination John H. Miller  

E-print Network

Communication and Coordination John H. Miller Scott Moser February 25, 2003 Abstract Remarkable levels of coordination are observed among social agents; yet the exact mechanisms by which such agents coordinate are not well understood. Here we examine the role of communication in achieving coordination

398

FOCLASA 2007 Comparing Three Coordination Models  

E-print Network

FOCLASA 2007 Comparing Three Coordination Models: Reo, ARC, and RRD Carolyn Talcott1 SRI Illinois Institute of Technology Chicago, IL 60616, USA Abstract Three models of coordination--Reo, Actors-Roles-Coordinators of coordination features. Mappings between their semantic models are defined. Use of the models is illustrated

399

The Convex Coordinates of the Symmedian Point  

ERIC Educational Resources Information Center

In this note, we recall the convex (or barycentric) coordinates of the points of a closed triangular region. We relate the convex and trilinear coordinates of the interior points of the triangular region. We use the relationship between convex and trilinear coordinates to calculate the convex coordinates of the symmedian point of the triangular

Boyd, J. N.; Raychowdhury, P. N.

2006-01-01

400

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.

401

ICCT Clearinghouse Transportation Coordination Primer  

E-print Network

Phase 2 ICCT Clearinghouse Transportation Coordination Primer A guidebook for creating a countywide of this Primer were based on Improving Transportation Opportunities for People with Disabilities in Illinois information about ICDD can be found at: www.state.il.us/agency/icdd/. In addition, this Primer utilizes

Illinois at Chicago, University of

402

ICCT Clearinghouse Transportation Coordination Primer  

E-print Network

Phase 3 ICCT Clearinghouse Transportation Coordination Primer A guidebook for creating a countywide of this Primer were based on Improving Transportation Opportunities for People with Disabilities in Illinois information about ICDD can be found at: www.state.il.us/agency/icdd/. In addition, this Primer utilizes

Illinois at Chicago, University of

403

ICCT Clearinghouse Transportation Coordination Primer  

E-print Network

Phase 1 ICCT Clearinghouse Transportation Coordination Primer A guidebook for creating a countywide of this Primer were based on Improving Transportation Opportunities for People with Disabilities in Illinois information about ICDD can be found at: www.state.il.us/agency/icdd/. In addition, this Primer utilizes

Illinois at Chicago, University of

404

Quantum Solution of Coordination Problems  

Microsoft Academic Search

We present a quantum solution to coordination problems that can be implemented with present technologies. It provides an alternative to existing approaches, which rely on explicit communication, prior commitment or trusted third parties. This quantum mechanism applies to a variety of scenarios for which existing approaches are not feasible.

Bernardo A. Huberman; Tad Hogg

2003-01-01

405

Computer (PC/Network) Coordinator.  

ERIC Educational Resources Information Center

This publication contains 22 subjects appropriate for use in a competency list for the occupation of computer (PC/network) coordinator, 1 of 12 occupations within the business/computer technologies cluster. Each unit consists of a number of competencies; a list of competency builders is provided for each competency. Titles of the 22 units are as

Ohio State Univ., Columbus. Center on Education and Training for Employment.

406

International Space Exploration Coordination Group  

E-print Network

on Earth. This document presents the status of the space agency exploration road mapping activityInternational Space Exploration Coordination Group The Global Exploration Roadmap August 2013 #12 ankles. The water seems inviting. The ocean calls." --Dr. Carl Sagan #12;The Global Exploration Roadmap

Rathbun, Julie A.

407

Fiat Money and Coordination: A \\  

Microsoft Academic Search

This paper attempts to combine important insights on matching models of money with insights from the macroeconomic coordination game-technological complementarity literature. One important old insight, but which has been refined lately, is that money is imperfect information. Further, one simple specification of incomplete information in particular, which has proven fruitful in motivating outside fiat money in matching environments, is to

John Bryant

2005-01-01

408

Waste Management Coordinating Lead Authors  

E-print Network

waste incineration .............................599 10.4 Mitigation of post-consumer emissions from-use and recycling ..............602 10.4.6 Wastewater and sludge treatment.....................602 10.4.7 Waste10 Waste Management Coordinating Lead Authors: Jean Bogner (USA) Lead Authors: Mohammed Abdelrafie

Columbia University

409

Coordinating Multi-Transaction Activities  

Microsoft Academic Search

Data processing applications must often execute collections of related transactions. We propose a model for structuring and coordinating these multi-transaction activities. The model includes mechanisms for communication between transactions, for compensating transactions after an activity has failed, for dynamic creation and binding of activities, and for checkpointing the progress of an activity.

Hector Garcia-Molina; Dieter Gawlick; Johannes Klein; Karl Kleissner; Kenneth Salem

1990-01-01

410

ACADEMIC SUPPORT COORDINATOR POSITION DESCRIPTION  

E-print Network

in Higher Education, Counseling, Student Affairs or related content area; strong interpersonal and oral undergraduate student success. This position supports an innovative and holistic approach to providing students Coordinator are to foster successful transition to the university environment by students in their initial

Stephens, Graeme L.

411

Motion Coordination Using Virtual Nodes  

E-print Network

We describe how a virtual node abstraction layer can be used to coordinate the motion of real mobile nodes in a region of 2-space. In particular, we consider how nodes in a mobile ad hoc network can arrange themselves along ...

Lynch, Nancy

2005-04-06

412

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

413

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

414

Physical Science Scott Bergeson, Coordinator  

E-print Network

Physical Science Scott Bergeson, Coordinator N-267 ESC, (801) 422-6161 College of Physical and Mathematical Sciences Advisement Center N-179 ESC, (801) 422-6270 BS Teaching Physical Science (77.5­78.5 hours that may fulfill university core requirements. Physical Science (Phy S) Undergraduate Courses 100. Physical

Hart, Gus

415

Coordinated Control of HVAC Systems  

E-print Network

finite state machine is used to handle the case where a single unit has multiple stages of operation. An optimized coordinator determines the phase of the PWM signals of each unit so that peak demand for power is minimized over each PWM period. Control...

Federspiel, C.; Lanning, S. D.; Li, H.; Auslander, D. M.

2001-01-01

416

Intramolecular Strain Coordinates Kinesin Stepping  

E-print Network

Present address: Department of Applied Physics, University of Tokyo, 113-8656 Tokyo, Japan *Correspondence identical motor domains remains unresolved. Here, we have tested whether such coordination is medi- ated by intramolecular tension generated by the ``neck linkers,'' mechanical elements that span be- tween the motor

Vale, Ronald D.

417

Collaborative and Coordinated Product Configuration  

E-print Network

Collaborative and Coordinated Product Configuration Marcilio Mendonca1 , Toacy Oliveira2 , Donald. This process is error-prone and risky as requirements may lead to conflicting decisions at configuration time collaborative nature. In our research, we advocate that product configuration is enhanced by a collaborative

Waterloo, University of

418

Playing safe in coordination games  

Microsoft Academic Search

This paper presents results from a series of experiments designed to test the impact on subject behavior of changes in the risk dominance and payoff dominance characteristics of two player coordination games. The main finding is that changes in risk dominance significantly affect play of the subjects, whereas changes in the level of payoff dominance do not. Observed history of

David Schmidt; Robert Shupp; James M. Walker; Elinor Ostrom

2003-01-01

419

GEAR Tech-21 Geographic Coordinates  

E-print Network

GEAR Tech-21 Geographic Coordinates 1 Established Goals Activity Outline Activity Timeline Knowledge and Skills Essential Vocabulary Explorers will know ... Every location on Earth has a unique pair model of the Earth used by GPS. Latitude ­ geographic position in North-South direction and changes

Farritor, Shane

420

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

421

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

422

Electroconvective stability of a weakly conducting liquid  

Microsoft Academic Search

In inhomogeneous electric fields, at sufficiently high field strengths, a weakly conducting liquid becomes unstable and is set in motion [14]. The cause of the loss of stability and the motion is the Coulomb force acting on the space charge formed by virtue of the inhomogeneity of the electrical conductivity of the liquid [413]. This inhomogeneity may be due to

A. I. Zhakin

1979-01-01

423

Weak shock wave reflection from concave surfaces  

NASA Astrophysics Data System (ADS)

The reflection of very weak shock waves from concave curved surfaces has not been well documented in the past, and recent studies have shown the possible existence of a variation in the accepted reflection configuration evolution as a shock wave encounters an increasing gradient on the reflecting surface. The current study set out to investigate this anomaly using high-resolution photography. Shock tube tests were done on various concave circular and parabolic geometries, all with zero initial ramp angle. Although the results have limitations due to the achievable image resolution, the results indicate that for very weak Mach numbers, M S < 1.1, there may be a region in which the reflection configuration resembles that of a regular reflection, unlike for the stronger shock wave case. This region exists after the triple point of the Mach reflection meets the reflecting surface and prior to the formation of the additional shock structures that represent a transitioned regular reflection. The Mach and transitioned regular reflections at 1.03 < M s < 1.05 also exhibit no signs of a visible shear layer, or a clear discontinuity at the triple point, and are thus also apparently different in the weak shock regime than what has been described for stronger shocks, similar to what has been shown for weak shocks reflecting off a plane wedge.

Gruber, Sebastien; Skews, Beric

2013-07-01

424

WEAK THRESHOLDING GREEDY ALGORITHMS IN BANACH SPACES  

E-print Network

WEAK THRESHOLDING GREEDY ALGORITHMS IN BANACH SPACES S. J. DILWORTH, DENKA KUTZAROVA, TH thresholding greedy algorithms with respect to Markushevich bases in general Banach spaces. We find sufficient" and "semi-greedy" systems. Contents 1. Introduction 2 2. Branch greedy algorithms 5 3. Convergence 6 4

Dilworth, Stephen

425

Flexible Update Propagation for Weakly Consistent Replication  

Microsoft Academic Search

Bayou's anti-entropy protocol for update propagation between weakly consistent storage replicas is based on pair-wise communication, the propagation of write operations, and a set of ordering and closure. constraints on the propagation of the writes. The simplicity of the design makes the protocol very flexible, thereby providing support for diverse networking environments and usage scenarios. It accommodates a variety of

Karin Petersen; Mike J. Spreitzer; Douglas B. Terry; Marvin M. Theimer; Alan J. Demers

1997-01-01

426

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

427

Weak decays of doubly heavy hadrons  

Microsoft Academic Search

We explore the application and usefulness of the heavy quark symmetry to describe the weak decays of hadrons (mesons and baryons) containing two heavy quarks. Firstly, we address the internal dynamics of a heavy-heavy bound system with the help of estimates based on potential models, showing an approximate spin symmetry in the preasymptotic quark mass region including charmonium, bottonium and

Miguel Angel Sanchis-Lozano

1995-01-01

428

Weak decays of doubly heavy hadrons  

Microsoft Academic Search

We explore the application and usefulness of the heavy quark symmetry to describe the weak decays of hadrons (mesons and baryons) containing two heavy quarks. Firstly, we address the internal dynamics of a heavy-heavy bound system with the help of estimates based on potential models, showing an approximate spin symmetry in the preasymptotic quark mass region including charmonium, bottonium and

M A Sanchis-Lozano

1994-01-01

429

MARKOVIAN BRIDGES: WEAK CONTINUITY AND PATHWISE CONSTRUCTIONS  

E-print Network

MARKOVIAN BRIDGES: WEAK CONTINUITY AND PATHWISE CONSTRUCTIONS LO¨IC CHAUMONT AND GER´ONIMO URIBE BRAVO Abstract. A Markovian bridge is a probability measure taken from a disintegration of the law of an initial part of the path of a Markov process given its terminal value. As such, Markovian bridges admit

Paris-Sud XI, Université de

430

Fermi and the Theory of Weak Interactions  

E-print Network

The history of weak interactions starting with Fermi's creation of the beta decay theory and culminating in its modern avatar in the form of the electroweak gauge theory is described. Discoveries of parity violation, matter-antimatter asymmetry, W and Z bosons and neutrino mass are highlighted.

Rajasekaran, G

2014-01-01

431

Fermi and the Theory of Weak Interactions  

E-print Network

The history of weak interactions starting with Fermi's creation of the beta decay theory and culminating in its modern avatar in the form of the electroweak gauge theory is described. Discoveries of parity violation, matter-antimatter asymmetry, W and Z bosons and neutrino mass are highlighted.

G. Rajasekaran

2014-02-25

432

Boosting a Weak Learning Algorithm by Majority  

Microsoft Academic Search

We present an algorithm for improving the accuracy of algorithms for learningbinary concepts. The improvement is achieved by combining a large number of hypotheses,each of which is generated by training the given learning algorithm on adifferent set of examples. Our algorithm is based on ideas presented by Schapire inhis paper "The strength of weak learnability", and represents an improvement over

Yoav Freund

1995-01-01

433

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

434

Features of the adsorption of naproxen enantiomers on weak chiral anion-exchangers in nonlinear chromatography  

SciTech Connect

The retention mechanism of the enantiomers of naproxen on a Pirkle-type chiral stationary phase (CSP) was studied. This CSP is made of a porous silica grafted with quinidine carbamate. It can interact with the weak organic electrolyte naproxen either by adsorbing it or by ion-exchange. Using frontal chromatography, we explored the adsorption equilibrium under such experimental conditions that naproxen dissociates or cannot dissociate. Under conditions preventing ionic dissociation, the adsorption isotherms were measured, the adsorption energy distributions determined, and the chromatographic profiles calculated. Three different types of the adsorption sites were found for both enantiomers. The density and the binding energy of these sites depend on the nature of the organic modifier. Different solute species, anions, neutral molecules, solvent-ion associates, and solute dimers can coexist in solution, giving rise to different forms of adsorption. This study showed the unexpected occurrence of secondary steps in the breakthrough profiles of S-naproxen in the adsorption mode at high concentrations. Being enantioselective, this phenomenon was assumed to result from the association of solute molecules involving a chiral selector moiety. A multisite Langmuir adsorption model was used to calculate band profiles. Although this model accounts excellently for the experimental adsorption isotherms, it does not explain all the features of the breakthrough profiles. A comparison between the calculated and experimental profiles allowed useful conclusions concerning the effects of the adsorbate-adsorbate and adsorbate-solvent interactions on the adsorption mechanism.

Asnin, Leonid [University of Tennessee, Knoxville (UTK); Kaczmarski, Krzysztof [University of Tennessee and Rzeszow University of Technology, Poland; Guiochon, Georges A [ORNL

2008-01-01

435

Organic Solvent Tropical Report [SEC 1 and 2  

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 unmitigated organic solvent fire is within risk evaluation guidelines.

COWLEY, W.L.

2000-06-21

436

ROSE Process Offers Energy Savings for Solvent Extraction  

E-print Network

Kerr-McGee has developed and commercialized an energy-efficient solvent extraction process known as ROSE (Residuum Oil Supercritical Extraction) in which the extraction solvent is recovered as a supercritical fluid. The energy requirement...

Gearheart, J. A.; Nelson, S. R.

1983-01-01

437

Construction of prototype system for directional solvent extraction desalination  

E-print Network

Directional solvent extraction has been demonstrated as a low temperature, membrane free desalination process. This method dissolves the water into an inexpensive, benign directional solvent, rejects the contaminants, then ...

Fowler, Michael James

2012-01-01

438

The Ideal Solvent for Paper Chromatography of Food Dyes.  

ERIC Educational Resources Information Center

Uses paper chromatography with food dyes to provide a simple and inexpensive basis for teaching chromatography. Provides experimental methodology and tabled results. Includes a solvent system comparison (Rf) for seven dyes and twenty-two solvents. (MVL)

Markow, Peter G.

1988-01-01

439

Safety in the Chemical Laboratory: Cyclohexane as a Cryoscopic Solvent.  

ERIC Educational Resources Information Center

Suggests that cyclohexane be used as a solvent in experiments usually using benzene, which has been placed on the list of chemicals that are confirmed carcinogens. Reasons for selection of cyclohexane and experimental procedures using this solvent are described. (CS)

Steffel, Margaret J.

1981-01-01

440

40 CFR 52.1145 - Regulation on organic solvent use.  

...organic solvents or materials containing organic solvents. (2) The spraying or other use of insecticides, pesticides, or herbicides. (3) The employment, application, evaporation, or drying of saturated halogenated hydrocarbons or...

2014-07-01

441

EXTRACTION OF CHEMICAL POLLUTANTS FROM INDUSTRIAL WASTEWATERS WITH VOLATILE SOLVENTS  

EPA Science Inventory

Solvent extraction with volatile solvents was studied as a method for treating wastewaters from petroleum refineries and petrochemical plants. Extraction is most attractive when the loading of organics is high, when substances are present which pose difficulties for biological ox...

442

Averaged coordination numbers of planar aperiodic tilings  

E-print Network

We consider averaged shelling and coordination numbers of aperiodic tilings. Shelling numbers count the vertices on radial shells around a vertex. Coordination numbers, in turn, count the vertices on coordination shells of a vertex, defined via the graph distance given by the tiling. For the Ammann-Beenker tiling, we find that coordination shells consist of complete shelling orbits, which enables us to calculate averaged coordination numbers for rather large distances explicitly. The relation to topological invariants of tilings is briefly discussed.

Michael Baake; Uwe Grimm

2005-09-18

443

Solvent-dependent luminescent Cu(I) framework based on 5-(4-pyridyl)tetrazole  

NASA Astrophysics Data System (ADS)

A new Cu(?) coordination compound, Cu 4(L) 42EtOH ( 1), has been obtained from the solvothermal reaction of CuBr, HL (L=5-(4-pyridyl) tetrazole), EtOH and NH 3H 2O. The structure determination reveals that 1 has a 2D network, where each Cu(I) atom adopts a trigonal coordination mode. The 2D networks stacked in an ABAB sequence through the ?-? interaction to form a 3D supramolecular framework, giving a 1D channel along the b-axis. The TGA and powder XRD measurements reveal that the framework is stable after removal of the guest molecules. Gas (N 2) adsorption measurement was carried out for the framework. Framework 1 shows II sorption profile with N 2, which indicates that N 2 molecules cannot diffuse into the micropore and only surface adsorption occurs. The photoluminescent research shows that compound 1 displays an interesting solvent-dependent luminescence.

Wang, Fei; Yu, Rongmin; Zhang, Qi-Sheng; Zhao, Zhen-Guo; Wu, Xiao-Yuan; Xie, Yi-Ming; Qin, Li; Chen, Shan-Ci; Lu, Can-Zhong

2009-09-01

444

Cavity functions and association in models for weak electrolytes and sticky hard spheres  

NASA Astrophysics Data System (ADS)

Weak electrolytes and other association reactions are modeled as sticky spheres. An analysis of the density expansion, including the bridge diagrams, of the cavity functions yAB(L) for sticky hard spheres (charged or uncharged spheres binding at a distance L) leads to an approximation which provides the degree of association ? as the solution to a simple quadratic equation determined by the association constant K0 and the cavity function y0AB(L) for the reference system in which the chemical bonding between the reacting species has been turned off. Similar relations are assumed to hold when the bonding is directional and specific enough to lead only to the formation of dimers. Applications to the determination of the reference cavity functions for acetic acid and monochloro acetic acid from experimental data of the degree of association are discussed. In a discrete solvent, the approximation scheme for ? remains the same, except that the reference cavity function is scaled differently. Solvent medium effects on the association constant are shown to be related to the cavity function of the undissociated dimer in a pure solvent. An exponential approximation for the reference cavity function y0AB(L) is derived when the associating species are of the same size and the bonding is spherically symmetric. Expressions for the changes in the thermodynamic functions due to association are obtained analytically in terms of the degree of association and the reference cavity functions. The magnitude of the degree of association, calculated from the exponential approximation for y0AB(L), and its effect on the thermodynamic properties are different from what was previously observed using the hypernetted chain (HNC) approximation. The thermodynamics of weak 1-1 electrolytes are discussed using the new method and a comparison is made between the new and old methods for 2-2 electrolytes.

Rasaiah, Jayendran C.; Zhu, Jianjun

1990-06-01

445

Production of biodiesel using expanded gas solvents  

SciTech Connect

A method of producing an alkyl ester. The method comprises providing an alcohol and a triglyceride or fatty acid. An expanding gas is dissolved into the alcohol to form a gas expanded solvent. The alcohol is reacted with the triglyceride or fatty acid in a single phase to produce the alkyl ester. The expanding gas may be a nonpolar expanding gas, such as carbon dioxide, methane, ethane, propane, butane, pentane, ethylene, propylene, butylene, pentene, isomers thereof, and mixtures thereof, which is dissolved into the alcohol. The gas expanded solvent may be maintained at a temperature below, at, or above a critical temperature of the expanding gas and at a pressure below, at, or above a critical pressure of the expanding gas.

Ginosar, Daniel M [Idaho Falls, ID; Fox, Robert V [Idaho Falls, ID; Petkovic, Lucia M [Idaho Falls, ID

2009-04-07

446

Catalytic coal liquefaction with treated solvent and SRC recycle  

DOEpatents

A process for the solvent refining of coal to distillable, pentane soluble products using a dephenolated and denitrogenated recycle solvent and a recycled, pentane-insoluble, solvent-refined coal material, which process provides enhanced oil-make in the conversion of coal.

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

1986-01-01

447

Modeling viscosity of concentrated and mixed-solvent electrolyte systems  

Microsoft Academic Search

A comprehensive model has been developed for calculating the viscosity of aqueous or mixed-solvent electrolyte systems ranging from dilute solutions to fused salts. The model incorporates a mixing rule for calculating the viscosity of solvent mixtures and a method for predicting the effect of finite electrolyte concentrations. The mixing rule represents the viscosity of multi-component solvent mixtures using molar volumes

Peiming Wang; Andrzej Anderko; Robert D. Young

2004-01-01

448

Comparison of Common Solvent Evaporation Techniques in Organic Analysis  

Microsoft Academic Search

Isolation of organic constituents from water frequently involves an extraction with a large volume of organic solvent which must be reduced to achieve the desired sensitivity. The objective of this research was to evaluate common solvent evaporation techniques to determine which are acceptable for use in pollutant analysis. Techniques for solvent reduction from 200 to 10 mL (macro) and 8

Mitchell D. Erickson; Mary T. Giguere; Donald A. Whitaker

1981-01-01

449

Dynamics around solutes and solutesolvent complexes in mixed solvents  

E-print Network

Dynamics around solutes and solute­solvent complexes in mixed solvents Kyungwon Kwak, Sungnam Park- benzene), and the mixed solvent of mesitylene and CCl4 (0.83 mole fraction CCl4), are used to study solute solution, there is only complexed phenol; in the CCl4 solution, there is only uncomplexed phenol

Fayer, Michael D.

450

Solvent Distillation Studies for a Purex Reprocessing Plant  

Microsoft Academic Search

A distillation system has been developed for regeneration of Purex solvent and will be implemented for the first time in a reprocessing plant. The results are described and analyzed, with emphasis on laboratory experiments which were made with a radioactive plant solvent. Particularly the distillation provides a good separation of solvent degradation products, which was verified by measurements of interfacial

C. Ginisty; B. Guillaume

1990-01-01

451

USE OF ORGANIC SOLVENTS IN TEXTILE SIZING AND DESIZING  

EPA Science Inventory

The report gives results of a study of textile sizing and desizing in organic solvents. Properties of materials applicable as warp sizes in organic solvents were satisfactory for use as warp sizes. Properties of fabrics made from solvent-sized yarns were equal in quality to those...

452

Solvent structure and hydrodynamic effects in photoinduced electron transfer  

Microsoft Academic Search

A previously developed statistical mechanical theory describing photo-induced electron transfer and geminate recombination in liquid solutions has been modified to account for realistic finite-volume solvent effects. This work introduces physically important effects caused by the solvent which fundamentally affect the rates and spatial distribution of charge transfer events. The finite volume of solvent molecules gives rise to a nonuniform distribution

S. F. Swallen; Kristin Weidemaier; M. D. Fayer

1996-01-01

453

ALTERNATIVES TO CHLORINATED SOLVENTS FOR CLEANING AND DEGREASING  

EPA Science Inventory

This guide describes chemical alternatives to chlorinated solvents that eliminate the use of ozone-depleting chlorinated solvents and smog-forming solvents that contribute high levels of volatile organic compounds (VOC) to the atmosphere. oth commercially available and emerging c...

454

Evidences of nonideal mixing in poly(ethylene glycol)/organic solvent mixtures by Brillouin scattering.  

PubMed

The concentration dependence of the hypersonic properties of solutions of poly(ethylene glycol) of mean molecular mass 600 g/mol (PEG600) in benzene and toluene has been investigated by Brillouin scattering. The two solvents are very similar in structure and chemical properties, but while benzene is nonpolar, toluene possess a modest dipole. In both solvents a high-frequency relaxation process has been observed at high concentrations which has been assigned to conformational rearrangements of the polymeric chains, triggered by reorientation of the side groups. In both cases, the concentration dependence of the adiabatic compressibility deviates significantly from linearity, indicating the existence of nonideal mixing phenomena driven by aggregation processes taking place in the systems. However, there is no temperature dependence for solutions of PEG600 in benzene; on the contrary, the results obtained for solutions of PEG600 in toluene are noticeably dependent on the temperature. The comparison of the experimental data with the results of previous experiments on similar systems allows a general picture for weakly interacting mixtures of hydrogen-bonded systems and organic solvents to be developed. In particular, in the presence of a nonpolar solvent molecule the local structure of the mixture is dominated by solute self-association processes and any resulting solute-solvent correlation is barely induced by excluded volume effects. At high enough dilution the self-aggregation of solute molecules produces a variety of new local topologies that cannot be observed in bulk solute, and as a consequence, the concentration evolution of the system is too rich to be described in terms of a linear combination of a few components over the whole concentration range. The situation seems to be simpler for the polar toluene solvent molecules, where a three-component model seems able to fit the experimental concentration dependence of the hypersonic velocity. This result is interpreted to imply that the interaction between the solvent dipoles and the active sites of the solute produces a relatively stable heterocoordination, while the relevance of self-association is partially reduced. PMID:16471559

Pochylski, M; Aliotta, F; B?aszczak, Z; Gapi?ski, J

2006-01-12

455

Enzyme-Catalyzed Processes in Organic Solvents  

Microsoft Academic Search

Three different lipases (porcine pancreatic, yeast, and mold) can vigorously act as catalysts in a number of nearly anhydrous organic solvents. Various transesterification reactions catalyzed by porcine pancreatic lipase in hexane obey Michaelis-Menten kinetics. The dependence of the catalytic activity of the enzyme in organic media on the pH of the aqueous solution from which it was recovered is bell-shaped,

Aleksey Zaks; Alexander M. Klibanov

1985-01-01

456

Animation of Gas Chromatography Solvent Focusing  

NSDL National Science Digital Library

This site has very good animations related to separations. It deals specifically with solvent focusing in gas chromatography. The animations are short (one to two minutes) and can easily be shown in class as part of a lecture. They are extremely helpful in illustrating key components and concepts of chromatographic systems. Users are encouraged to explore the site and the other brief animations as well. Separate links to other simulations by the same company (TRSL) are also listed on ASDL.

2011-05-09

457

Sluggish solvents and fast reactions: Dynamical arrest  

E-print Network

frequencies below obs=1/obs s= E 2 2kB T =0 ' ' d Fluctuation-dissipation theorem obs=obs ' ' d ' ' ' ' 2 Dielectric continuum Donor-acceptor energy gap #12; Step-wise Filter: Computer Experiment s=E2 /2kB T cV /kB=3/2 E 2 N kB T2 P=kB T V -1 M 2 #12; Stokes Shift in Supercooled Solvents k ,s=0

Matyushov, Dmitry

458

Brayton Solvent Recovery Heat Pump Technology Update  

E-print Network

approach. Two different demonstration units were installed and operated at 3M locations. They incorporated direct drive machinery (see Fig. 2). An improved process was developed by NUCON and installed at a pharmaceutical manufacturing plant which..., in the coat~ g of tablets in the pharmaceutical industry'/ the solvents used are methylene chloride d methanol. It is extremely difficult to these materials with activated carbon ystems because of the poor adsorption capaci for these high vapor pressure...

Enneking, J. C.

459

Unusually Strong Dependence of Conformation on Solvent  

Microsoft Academic Search

Relative partition coefficients between aqueous methanol and pentane of the two stereoisomers of a series of 4-tert-butylcyclohexylamines were measured by NMR. The cis isomer shows a larger partition coefficient, with a Gorgfaq up to 1.4 kcal\\/mol. A thermodynamic cycle relates these values to a solvent dependence of the A value for conformational equilibrium of an amino substituent. The variation with

Charles L. Perrin; Miles A. Fabian; Ignacio A. Rivero

1998-01-01

460

Solvent extraction of Southern US tar sands  

SciTech Connect

The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

Penney, W.R.

1990-01-01

461

Work as coordination and coordination as work: A process perspective on FLOSS development projects  

E-print Network

Work as coordination and coordination as work: A process perspective on FLOSS development projects Dipartimento Impresa e Lavoro Università degli Studi di Cassino Cassino Italy #12;Work as coordination and coordination as work: A process perspective on FLOSS development projects Abstract Coordination in work teams

Crowston, Kevin

462

Experimental solution thermodynamics of a ternary solvent/polymer/solvent system by inverse gas chromatography / by Dominic Wai Wah Ching  

E-print Network

EXPERIMENTAL SOLUTION THERMODYNAMICS OF A TERNARY SOLVENT/POLYSER/SOLVENT SYSTEM BY INVERSE GAS CHROMATOGRAPHY A Thesis by DOMINIC WAI WAH CHING Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE August 1978 Major Subjects Chemical Engineering EXPERIMENTAL SOLUTION THERMODYNAMICS OF A TERNARY SOLVENT/POLYMER/SOLVENT SYSTEM BY INVERSE GAS CHROMATOGRAPHY A Thesis DOMINIC WAI WAH CHING Approved...

Ching, Dominic Wai Wah

2012-06-07

463

WEAK GREEDY ALGORITHMS 1 V.N.Temlyakov  

E-print Network

WEAK GREEDY ALGORITHMS 1 V.N.Temlyakov Department of Mathematics, University of South Carolina, Columbia, SC 29208 Abstract. Theoretical greedy type algorithms are studied: a Weak Greedy Algo­ rithm, a Weak Orthogonal Greedy Algorithm, and a Weak Relaxed Greedy Algo­ rithm. These algorithms are defined

South Carolina, University of

464

Continual coordination through shared activities  

NASA Technical Reports Server (NTRS)

Interacting agents that interleave planning and execution must reach consensus on their commitments to each other. In domains where agents have varying degrees of interaction and different constraints on communication and computation, agents will require different coordination protocols in order to efficiently reach consensus in real time. We briefly describe a largely unexplored class of realtime, distributed planning problems (inspired by interacting spacecraft missions), new challenges they pose, and a general approach to solving the problems. These problems involve self-interested agents that have infrequent communication but collaborate on joint activities. We describe a Shared Activity Coordination (SHAC) framework that provides a decentralized algorithm for negotiating the scheduling of shared activities over the lifetimes of separate missions, a soft, real-time approach to reaching consensus during execution with limited communication, and a foundation for customizing protocols for negotiating planner interactions. We apply SHAC to a realistic simulation of interacting Mars missions and illustrate the simplicity of protocol development.

Clement, Bradley J.; Barrett, Anthony C.

2003-01-01

465

A coordination theory for intelligent machines  

NASA Technical Reports Server (NTRS)

A formal model for the coordination level of intelligent machines is established. The framework of the coordination level investigated consists of one dispatcher and a number of coordinators. The model called coordination structure has been used to describe analytically the information structure and information flow for the coordination activities in the coordination level. Specifically, the coordination structure offers a formalism to (1) describe the task translation of the dispatcher and coordinators; (2) represent the individual process within the dispatcher and coordinators; (3) specify the cooperation and connection among the dispatcher and coordinators; (4) perform the process analysis and evaluation; and (5) provide a control and communication mechanism for the real-time monitor or simulation of the coordination process. A simple procedure for the task scheduling in the coordination structure is presented. The task translation is achieved by a stochastic learning algorithm. The learning process is measured with entropy and its convergence is guaranteed. Finally, a case study of the coordination structure with three coordinators and one dispatcher for a simple intelligent manipulator system illustrates the proposed model and the simulation of the task processes performed on the model verifies the soundness of the theory.

Wang, Fei-Yue; Saridis, George N.

1990-01-01

466

Recovery of some common solvents from protective clothing breakthrough indicator pads by microwave-solvent extraction and gas chromatography.  

PubMed

The efficiency of solvent adsorption using Permea-Tec general solvent pads, used for the detection of chemical breakthrough of protective clothing, was determined for methanol, acetone, ethyl methyl ketone, trichloroethylene (TriCE), tetrachloroethylene (TetCE), toluene, m-xylene, and D-limonene. Known volumes of single or mixed solvents were added to pads in the range 0.2-5.0 microliters (0.16-8.13 micrograms). After microwave-solvent extraction (ME) into hexan-1-ol, the samples (0.5-3.0 microliters) of the filtered and extracted solutions were analyzed by gas chromatography. All solvents exhibited > 97% adsorption on the pads at spiking levels of 0.48-0.98 microgram for each solvent. The solvent recovery for the system was calculated for each solvent, with solvents with boiling points below 110 degrees C showing recoveries of > 90%, and with solvents with boiling points above 110 degrees C showing recoveries from 80 to 90%. The recovery precision was good (RSD < or = 4%) for all solvents over the range 1.0-2.5 microliters of applied solvents to pads for ME and 1.0 microliter of extracted solutions for GC analysis. PMID:10736878

Vo, E; Berardinelli, S P; Hall, R C

1999-06-01

467

Galaxy Halo Masses from Weak Gravitational Lensing  

E-print Network

In this review, I discuss the use of galaxy-galaxy weak lensing measurements to study the masses of dark matter halos in which galaxies reside. After summarizing how weak gravitational lensing measurements can be interpreted in terms of halo mass, I review measurements that were used to derive the relationship between optical galaxy mass tracers, such as stellar mass or luminosity, and dark matter halo mass. Measurements of galaxy-galaxy lensing from the past decade have led to increasingly tight constraints on the connection between dark matter halo mass and optical mass tracers, including both the mean relationships between these quantities and the intrinsic scatter between them. I also review some of the factors that can complicate analysis, such as the choice of modeling procedure, and choices made when dividing up samples of lens galaxies.

Mandelbaum, Rachel

2014-01-01

468

Relaxation polarizations: Strong and weak processes  

NASA Astrophysics Data System (ADS)

It has been shown that the through conductivity can differently affect the frequency dependences of the dielectric loss tangent of dielectrics with relaxation polarization. According to this difference, the relaxations in dielectrics are divided into two types: strong and weak. In the case of strong relaxations, the frequency dependences of the imaginary part of the complex conductivity exhibit extrema. Strong and weak relaxations have been investigated in Debye and in non-Debye dielectrics in order to determine the boundary between these processes and explain the existence of relaxations of two types. It has been established that the relaxations in dielectrics can be separated because of the different ratios of the contributions to the polarization of dielectrics from the fast and relaxation polarizations. The corresponding data in the literature are reviewed and the data on the development of strong relaxations in heterogeneous dielectrics are reported.

Bogatin, A. S.

2012-01-01

469

The Q_weak Experimental Apparatus  

E-print Network

The Jefferson Lab Q_weak experiment determined the weak charge of the proton by measuring the parity-violating elastic scattering asymmetry of longitudinally polarized electrons from an unpolarized liquid hydrogen target at small momentum transfer. A custom apparatus was designed for this experiment to meet the technical challenges presented by the smallest and most precise ${\\vec{e}}$p asymmetry ever measured. Technical milestones were achieved at Jefferson Lab in target power, beam current, beam helicity reversal rate, polarimetry, detected rates, and control of helicity-correlated beam properties. The experiment employed 180 microA of 89% longitudinally polarized electrons whose helicity was reversed 960 times per second. The electrons were accelerated to 1.16 GeV and directed to a beamline with extensive instrumentation to measure helicity-correlated beam properties that can induce false asymmetries. Moller and Compton polarimetry were used to measure the electron beam polarization to better than 1%. The ...

Allison, T; Androic, D; Armstrong, D S; Asaturyan, A; Averett, T D; Averill, R; Balewski, J; Beaufait, J; Beminiwattha, R S; Benesch, J; Benmokhtar, F; Bessuille, J; Birchall, J; Bonnell, E; Bowman, J; Brindza, P; Brown, D B; Carlini, R D; Cates, G D; Cavness, B; Clark, G; Cornejo, J C; Dusa, S Covrig; Dalton, M M; Davis, C A; Dean, D C; Deconinck, W; Diefenbach, J; Dow, K; Dowd, J F; Dunne, J A; Dutta, D; Duvall, W S; Echols, J R; Elaasar, M; Falk, W R; Finelli, K D; Finn, J M; Gaskell, D; Gericke, M T W; Grames, J; Gray, V M; Grimm, K; Guo, F; Hansknecht, J; Harrison, D J; Henderson, E; Hoskins, J R; Ihloff, E; Johnston, K; Jones, D; Jones, M; Jones, R; Kargiantoulakis, M; Kelsey, J; Khan, N; King, P M; Korkmaz, E; Kowalski, S; Kubera, A; Leacock, J; Leckey, J P; Lee, A R; Lee, J H; Lee, L; Liang, Y; MacEwan, S; Mack, D; Magee, J A; Mahurin, R; Mammei, J; Martin, J W; McCreary, A; McDonald, M H; McHugh, M J; Medeiros, P; Meekins, D; Mei, J; Michaels, R; Micherdzinska, A; Mkrtchyan, A; Mkrtchyan, H; Morgan, N; Musson, J; Mesick, K E; Narayan, A; Ndukum, L Z; Nelyubin, V; Nuruzzaman,; van Oers, W T H; Opper, A K; Page, S A; Pan, J; Paschke, K D; Phillips, S K; Pitt, M L; Poelker, M; Rajotte, J F; Ramsay, W D; Roberts, W R; Roche, J; Rose, P W; Sawatzky, B; Seva, T; Shabestari, M H; Silwal, R; Simicevic, N; Smith, G R; Sobczynski, S; Solvignon, P; Spayde, D T; Stokes, B; Storey, D W; Subedi, A; Subedi, R; Suleiman, R; Tadevosyan, V; Tobias, W A; Tvaskis, V; Urban, E; Waidyawansa, B; Wang, P; Wells, S P; Wood, S A; Yang, S; Zhamkochyan, S; Zielinski, R B

2014-01-01

470

[The personality of children with weak posture].  

PubMed

An attempt is made on two groups of children with weak posture and of normal children aged 8 to 10 years to demonstrate a statistical link between fibrous tissue-weakness and certain psychological characteristics. In tests and observations of experiences and behavior of children one finds: Compared with the controls the children showing symptoms suffer psychosomatic changes. The cause is held to be not just increased psychomotor clumsiness, but their behavior pattern is essentially due to psychological pressure of their environment (parents, school, friends etc). This leads to: reduction self-confidence, increased experience of failure, hypercompensatory view of the self with strong criticism of others and again physical dysfunction. To offer treatment is not enough. We have to demand a spread of information, cooperative efforts of teachers , school-physicians and parents and education by team-work. PMID:1098297

Sell, G; Hastenteufel, R; Schade, B

1975-02-01

471

SUNGLASS: A new weak lensing simulation pipeline  

E-print Network

A new cosmic shear analysis pipeline SUNGLASS (Simulated UNiverses for Gravitational Lensing Analysis and Shear Surveys) is introduced. SUNGLASS is a pipeline that rapidly generates simulated universes for weak lensing and cosmic shear analysis. The pipeline forms suites of cosmological N-body simulations and performs tomographic cosmic shear analysis using line-of-sight integration through these simulations while saving the particle lightcone information. Galaxy shear and convergence catalogues with realistic 3D galaxy redshift distributions are produced for the purposes of testing weak lensing analysis techniques and generating covariance matrices for data analysis and cosmological parameter estimation. We present a suite of fast medium resolution simulations with shear and convergence maps for a generic 100 square degree survey out to a redshift of z = 1.5, with angular power spectra agreeing with the theory to better than a few percent accuracy up to l = 10^3 for all source redshifts up to z = 1.5 and wav...

Kiessling, A; Taylor, A N

2010-01-01

472

An intramolecular N-H...(mu-H)Re2 dihydrogen bond and a novel mu 3-eta 2 coordination mode of the pyrazolate anion on a triangular cluster face.  

PubMed

The quantitative addition of pyrazole (Hpz) to the 44 valence-electron, triangular cluster anion [Re3(mu 3-H)-(mu-H)3(CO)9]- gives the novel unsaturated anion [Re3(mu-H)4(CO)9(Hpz)]- (1, 46 valence electrons), which contains a pyrazole molecule that is terminally coordinated on a cluster vertex. Solidstate X-ray and IR analyses reveal a rather weak hydrogen-bonding interaction between the NH proton and one of the hydrides bridging the opposite triangular cluster edge (delta H degree = -3.1 kcal mol-1 from the Iogansen equation). Both IR and NMR data indicate that such a proton-hydride interaction is maintained in the major conformer present in CD2Cl2, but also provide evidence of the presence of minor conformers of 1 in which the NH proton is involved in an intermolecular hydrogen bond with the solvent. The mu-H...HN bond length evaluated in solution through the T1 minimum value (2.07 A) and that determined in the solid state by X-ray diffraction (2.05 A) are in good agreement. NMR experiments show that, in acetone, intermolecular N-H...solvent interactions replace the intramolecular dihydrogen bond. At room temperature in CH2Cl2, the pyrazole ligand in 1 is labile and 1 slowly "disproportionates" to [Re3(mu 3-H)-(mu-H)3(CO)9]- and [Re3(mu-H)3(CO)9-(mu-eta 2-pz)(Hpz)]-, with H2 evolution. Slow H2 evolution also leads to the formation of the anion [Re3(mu-H)3-(CO)9(pz)]- (5), in which the pyrazolate anion adopts a novel mu 3-eta 2-coordination mode, as revealed by a single-crystal X-ray analysis. The analysis of the bond lengths indicates that the pyrazolate anion in 5 acts as a six-electron donor, with loss of the aromaticity. The formation of 5 from 1 is much faster in solvents with a high dielectric constant, such as acetone or DMF. Anion 5 was also obtained from the reaction of pyrazole with [Re3(mu-H)3(CO)9(mu 3-CH3)]- through the intermediate formation of two isomeric addition derivatives and following CH4 evolution. PMID:12561305

Beringhelli, Tiziana; D'Alfonso, Giuseppe; Panigati, Monica; Mercandelli, Pierluigi; Sironi, Angelo

2002-12-01

473

Residue currents associated with weakly holomorphic functions  

NASA Astrophysics Data System (ADS)

We construct Coleff-Herrera products and Bochner-Martinelli type residue currents associated with a tuple f of weakly holomorphic functions, and show that these currents satisfy basic properties from the (strongly) holomorphic case. This include the transformation law, the Poincar-Lelong formula and the equivalence of the Coleff-Herrera product and the Bochner-Martinelli type residue current associated with f when f defines a complete intersection.

Lrkng, Richard

2012-04-01

474

Anisotropy of Weakly Vibrated Granular Flows  

E-print Network

We experimentally probe the anisotropy of the fabric of weakly vibrated, flowing granular media. Depending on the driving parameters --- flow rate and vibration strength --- this anisotropy varies significantly. We show how the anisotropy collapses when plotted as function of the driving stresses, uncovering a direct link between stresses and anisotropy. Moreover, our data suggests that for small anisotropies, the shear stresses vanish. Anisotropy of the fabric of granular media thus plays a crucial role in determining the rheology of granular flows.

Geert Wortel; Martin van Hecke

2014-10-16

475

On weak shock diffraction in real gases  

E-print Network

Asymptotic solutions are obtained for the two-dimensional Euler system for real gases with appropriate boundary conditions which describe the diffraction of a weak shock at a right-angled wedge; the real gas effects are characterized by a van der Waals type equation of state. The behavior of the flow configuration influenced by the real gas effects, that includes the local structure near a singular point, is studied in detail.

Neelam Gupta; V. D. Sharma

2014-05-17

476

Precision frequency measurements with interferometric weak values  

E-print Network

We demonstrate an experiment which utilizes a Sagnac interferometer to measure a change in optical frequency of 129 kHz per root Hz with only 2 mW of continuous wave, single mode input power. We describe the measurement of a weak value and show how even higher frequency sensitivities may be obtained over a bandwidth of several nanometers. This technique has many possible applications, such as precision relative frequency measurements and laser locking without the use of atomic lines.

David J. Starling; P. Ben Dixon; Andrew N. Jordan; John C. Howell

2011-01-07

477

Numerical analysis of weakly nonlinear wave turbulence.  

PubMed

We consider the propagation of weakly nonlinear waves such as plasma waves, surface water waves, the interaction of laser beams with matter, particle accelerators, etc. Specifically, we study internal waves in the ocean. Hamilton's principle is used to write the fluid equations in Hamiltonian form in terms of linear eigenmode amplitudes. Numerical studies are made of the effect of Fourier grid size and resonance widths. Statistical information is generated from an ensemble of initial states of the random wave field. PMID:16592648

Meiss, J D; Pomphrey, N; Watson, K M

1979-05-01

478

Vortices in weakly coupled layered superconductors  

Microsoft Academic Search

The vortex system in high-temperature layered superconductors exhibits a rich phase diagram with many proposals of phase transitions modifying the correlations both within and between the layers. We focus on the limit where the magnetic coupling between pancake vortices dominates over the interlayer Josephson coupling. The weak, but long-ranged nature of this magnetic interaction allows for an accurate mean-field treatment

Matthew J. W. Dodgson; Vadim B. Geshkenbein; Gianni Blatter

2000-01-01

479

Are the 'weak measurements' really measurements?  

E-print Network

Weak measurements can be seen as an attempt at answering the 'Which way?' question without destroying interference between the pathways involved. Unusual mean values obtained in such measurements represent the response of a quantum system to this 'forbidden' question, in which the 'true' composition of virtual pathways is hidden from the observer. Such values indicate a failure of a measurement where the uncertainty principle says it must fail, rather than provide an additional insight into physical reality.

D. Sokolovski

2013-05-21

480

Weak 'Antigravity' Fields in General Relativity  

Microsoft Academic Search

Within the weak-field approximation of general relativity, new exact\\u000asolutions are derived for the gravitational field of a mass moving with\\u000aarbitrary velocity and acceleration. A mass having a constant velocity greater\\u000athan 3^-1\\/2 times the speed of light gravitationally repels other masses at\\u000arest within a narrow cone. At high Lorentz factors (gamma >> 1), the force of\\u000arepulsion

F. S. Felber

2005-01-01

481

Electrostatic Decay in a Weakly Magnetized Plasma  

NASA Astrophysics Data System (ADS)

The kinematics of the electrostatic (ES) decay of a Langmuir wave into a Langmuir wave and an ion sound wave are generalized to a weakly magnetized plasma. Unlike the unmagnetized case, ES decay in a magnetized plasma is always kinematically permitted and can produce daughter Langmuir waves with very small wave numbers, which we demonstrate by quasilinear simulations. The simulations further show that ES decay in magnetized plasmas is consistent with STEREO spacecraft observations of transversely polarized Langmuir waves in the solar wind.

Layden, A.; Cairns, Iver H.; Li, B.; Robinson, P. A.

2013-05-01

482

Ionic Capillary Evaporation in Weakly Charged Nanopores  

E-print Network

Using a variational field theory, we show that an electrolyte confined to a neutral cylindrical nanopore traversing a low dielectric membrane exhibits a first-order ionic liquid-vapor pseudo-phase-transition from an ionic-penetration "liquid" phase to an ionic-exclusion "vapor" phase, controlled by nanopore-modified ionic correlations and dielectric repulsion. For weakly charged nanopores, this pseudotransition survives and may shed light on the mechanism behind the rapid switching of nanopore conductivity observed in experiments.

Sahin Buyukdagli; Manoel Manghi; John Palmeri

2010-04-11

483

Generalization of the Weak Charged VA Current  

Microsoft Academic Search

In view of possible existence of the nucleonic second-class current, the weak charged urbaryonic and leptonic V-A currents are generalized so as to contain derivative currents by assuming two-component neutrino theory and baryon-lepton correspondence. Values of parameters associated with the derivative currents of lepton are determined from mu-, pi- and K-decays. The generalized currents can explain xi parameter of the

Takamitsu Oka

1978-01-01

484

Energy Current Correlations for Weakly Anharmonic Lattices  

Microsoft Academic Search

We discuss properties of the Boltzmann-Peierls equation for weakly anharmonic lattice dynamics. In particular, we explain\\u000a how energy type correlations are predicted from this transport equation. An intriguing application is the famous Fermi-Pasta-Ulam\\u000a ? chain, for which we prove that the energy current correlations in equilibrium decay for long times as t\\u000a ?3\\/5, in the kinetic approximation.

Herbert Spohn

2007-01-01

485

Rheology of Weakly Vibrated Granular Media  

E-print Network

We probe the rheology of weakly vibrated granular flows as function of flow rate, vibration strength and pressure by performing experiments in a vertically vibrated split-bottom shear cell. For slow flows, we establish the existence of a novel vibration dominated granular flow regime, where the driving stresses smoothly vanish as the driving rate is diminished. We distinguish three qualitatively different vibration dominated rheologies, most strikingly a regime where the shear stresses no longer are proportional to the pressure.

Geert H. Wortel; Joshua A. Dijksman; Martin van Hecke

2013-12-02

486

WEAK AMENABILITY OF TRIANGULAR BANACH ALGEBRAS  

Microsoft Academic Search

LetA andB be unital Banach algebras, and letM be a Banach A;B-module. Then T = AM 0 B becomes a triangular Banach algebra when equipped with the Banach space normk am 0 b k =kakA +kmkM + kbkB. A Banach algebraT is said to be n-weakly amenable if all derivations fromT into its nth dual space T (n) are inner.

B. E. FORREST; L. W. MARCOUX

487

SUNGLASS: A new weak lensing simulation pipeline  

Microsoft Academic Search

A new cosmic shear analysis pipeline SUNGLASS (Simulated UNiverses for\\u000aGravitational Lensing Analysis and Shear Surveys) is introduced. SUNGLASS is a\\u000apipeline that rapidly generates simulated universes for weak lensing and cosmic\\u000ashear analysis. The pipeline forms suites of cosmological N-body simulations\\u000aand performs tomographic cosmic shear analysis using line-of-sight integration\\u000athrough these simulations while saving the particle lightcone information.

A. Kiessling; A. F. Heavens; A. N. Taylor

2010-01-01

488

Spectral statistics for weakly correlated random potentials  

E-print Network

We study localization and derive stochastic estimates (in particular, Wegner and Minami estimates) for the eigenvalues of weakly correlated random discrete Schr\\"odinger operators in the localized phase. We apply these results to obtain spectral statistics for general discrete alloy type models where the single site perturbation is neither of finite rank nor of fixed sign. In particular, for the models under study, the random potential exhibits correlations at any range.

Frdric Klopp

2012-10-29

489

Ripple formation in weakly turbulent flow  

Microsoft Academic Search

.The formation of granular ripples under liquid shear flow in an annular channel is studied experimentally. The erodible granular\\u000a bed is subject to weakly turbulent flows without a defined sharp boundary layer close to the granular bed. The flow field\\u000a and the degree of turbulence is characterized quantitatively by using a particle image velocimeter and a laser-Doppler velocimeter,\\u000a respectively. A

A. Wierschem; C. Groh; I. Rehberg; N. Aksel; C. A. Kruelle

2008-01-01

490

The effect of coordinating and non-coordinating additives on the transport properties in ionic liquid electrolytes for lithium batteries.  

PubMed

In the present study we expand our analysis of using two contrasting organic solvent additives (toluene and THF) in an ionic liquid (IL)/Li NTf(2) electrolyte. Multinuclear Pulsed-Field Gradient (PFG) NMR, spin-lattice (T(1)) relaxation times and conductivity measurements over a wide temperature range are discussed in terms of transport properties and structuring of the liquid. The conductivity of both additive samples is enhanced the most at low temperatures, with THF slightly more effective than toluene. Both the anion and lithium self-diffusivity are enhanced in the same order by the additives (THF > toluene) while that of the pyrrolidinium cation is marginally enhanced. (1)H spin-lattice relaxation times indicate a reasonable degree of structuring and anisotropic motion within all of the samples and both (19)F and (7)Li highlight the effectiveness of THF at influencing the lithium coordination within these systems. PMID:21279209

Bayley, Paul M; Best, A S; MacFarlane, D R; Forsyth, M

2011-03-14

491

Batch extracting process using magnetic particle held solvents  

DOEpatents

A process is described for selectively removing metal values which may include catalytic values from a mixture containing same, wherein a magnetic particle is contacted with a liquid solvent which selectively dissolves the metal values to absorb the liquid solvent onto the magnetic particle. Thereafter the solvent-containing magnetic particles are contacted with a mixture containing the heavy metal values to transfer metal values into the solvent carried by the magnetic particles, and then magnetically separating the magnetic particles. Ion exchange resins may be used for selective solvents. 5 figs.

Nunez, L.; Vandergrift, G.F.

1995-11-21

492

Investigation on infrared spectra of androsterone in single solvents  

NASA Astrophysics Data System (ADS)

The infrared absorption spectra of the androsterone in 19 pure organic solvents have been investigated. The carbonyl stretching vibration frequencies of androsterone observed in the solvents were correlated with the empirical parameters G, Swain parameters ( Aj and Bj) and the linear solvation energy relationships (LSER). The applicabilities of different parameters were discussed and the solute-solvent interactions in single solvents were studied in detail. The correlation results indicated that the LSER is optimal for a complete description of solute-solvent interactions while G-values and Swain parameters are unilateral.

Liu, Qing; Cong, Chao; Zhang, Hui

2007-12-01

493

Interaction of organic solvents with the green alga Chlorella pyrenoidosa  

SciTech Connect

Solvents are often a component of bioassay systems when water-insoluble toxicants are being tested. These solvents must also be considered as xenobiotics and therefore, as potential toxicants in the bioassay. However, the effects of solvents on the organisms being tested and their possible interaction with the test compound are often overlooked by researchers. The purpose of the present study was to compare the inhibitory effects of six solvents commonly used in pesticide bioassays towards growth of the common green alga Chlorella pyrenoidosa, and to examine the occurrence of solvent-pesticide interactions with this organism.

Stratton, G.W.; Smith, T.M. (Nova Scotia Agricultural College, Truro (Canada))

1988-06-01

494

Sequential accelerated solvent extraction of polycyclic aromatic hydrocarbons with different solvents: performance and implication.  

PubMed

Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) extracted by Soxhlet extraction (S-PAHs) with dichloromethane and routine accelerated solvent extraction (A-PAHs) with 1:1 toluene/methanol, respectively, were investigated in 24 soil samples from two cities in the center of the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons, methylphenanthrene and perylene, in two soils, two sediments, and an immature oil shale were also sequentially extracted by accelerated solvent extraction (ASE) with each of four different organic solvents for three times. The A-PAHs' concentrations are 2.41 times the S-PAHs' concentrations. For sequential three ASEs, PAHs in the first extract account for 56 to 67% of their total concentrations in the sequential three extractions and toluene displays the best extraction performance among the four solvents. Diagnostic ratios of PAHs in Soxhlet extraction, routine ASE, and sequential ASE with each solvent for a given sample are very similar, suggesting their identical petrogenic and pyrogenic sources in the soils and sediments. But the PAH ratios for the shale have an obvious petrogenic origin. The perylene/5-ring PAH ratios indicate a diagenetic source, especially in the shale and sediments. The correlation analysis shows that A-PAHs/S-PAHs is better associated with the contents of total organic carbon (TOC) than those of black carbon (BC). The above results indicate the significant petrogenic origin of PAHs and the important effect of organic matter on their extraction and distribution in the investigated field soils/sediments. PMID:21284305

Ma, Xiaoxuan; Ran, Yong; Gong, Jian; Chen, Diyun

2010-01-01

495

Electroreduction of Buckminsterfullerene, C{sub 60}, in aprotic solvents: Solvent, supporting electrolyte, and temperature effects  

SciTech Connect

The electroreductions of Buckminsterfullerene (C{sub 60}) in aprotic solvents were examined as a function of solvent, supporting electrolyte, and temperature. Altogether, 11 different solvents and 17 different supporting electrolytes were utilized in measurements made between 223 and 348 K. The cations of the supporting electrolytes were Li{sup +} and Na{sup +} as well as quaternary ammonium and quaternary phosphonium cations. The anions of the supporting electrolytes were ClO{sub 4}{sup {minus}}, BF{sub 4}{sup {minus}}, PF{sub 6}{sup {minus}}, and Br{sup {minus}}. Cyclic voltammograms, rotating disk electrode voltammograms, and controlled potential coulometry revealed up to five reversible one-electron reductions. A qualitative approach is used to elucidate the effects of solvent, supporting electrolyte and temperature on the half-wave potentials, E{sub 1/2}, of the reductions of C{sub 60}. A qualitative approach is used to elucidate the effects of solvent, supporting electrolyte, and temperature on the half-wave potentials, E{sub 1/2}, of the reductions of C{sub 60}. 38 refs., 5 figs., 7 tabs.

Dubois, D.; Moninot, G.; Kutner, W.; Jones, M.T.; Kadish, K.M. [Univ. of Houston, TX (United States)

1992-08-20