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1

Synthesis of four novel pendant armed macrocyclic ligands and their interaction with lanthanide(III) cations  

International Nuclear Information System (INIS)

The ability of La3+ ions to form stable complexes with four novel pendant-armed NxOy-macrocycles derived from 2,6-bis(2-formylphenoxymethyl)pyridine, L1, L2, L3, and L4, has been studied. The corresponding (unsubstituted) parent ligands were prepared by the reaction between 2,6-bis(2-formylphenoxymethyl)pyridine and three different amines: 1,2-bis(2-aminophenoxy)propane (L1), diethylenetriamine (L2), and 3,6-dioxa-1,8-octanediamine (L3 and L4). This was followed for the parent ligands of L1, L3, and L4 by in situ reduction with sodium borohydride. The pendant-armed ligands were then synthesized by the alkylation of the free -NH groups with p-(L1 and L3) and o-nitrobenzyl bromide (L4), and 2-chloromethylpyridine chlorohydrate (L2). A series of Ln(III) complexes (Ln=La, Ce, Eu, Sm, Ho, Pr) were prepared for the four ligands by the direct synthesis between the corresponding macrocycle and Ln(III) hydrated nitrates and perchlorates. The number of complexes obtained from the pendant-armed macrocycles is lower than that of the (unsubstituted) parent ones, suggesting that the introduction of pendant arms in the macrocyclic skeletons increases the selectivity of the ligands. More complexes were synthesized when using nitrate as the counter ion, showing the important role of the couion, showing the important role of the counter ion in the complexation reaction

2

The effect of pendant-arm modification and ring size on the dynamics of cyclic polyamines  

Science.gov (United States)

Carbon-13 relaxation studies have been performed on two cyclic polyamines—1,4,8,11-tetraazacyclotetradecane, N4R4_H, (cyclam) and 1,4,7,10,13,16-hexaazacyclooctadecane, N6R6_H, (hexacyclen), and on two synthesized N-substituted cyclam derivatives—1,4,8,11-tetrahexanoyl-1,4,8,11-tetraazacyclotetradecane, N4R4_CO(CH 2) 4CH 3, with aliphatic and 1,4,8,11-tetranaftalenesulfonyl-1,4,8,11-tetraazacyclotetradecane, N4R4_SO 2C 10H 7, with aromatic substituents. Longitudinal T1 relaxation and NOE measurements were performed in extreme narrowing region for basic polyamines and outside extreme narrowing region for substituted derivatives at room temperature and for magnetic strengths 400 and 500 MHz. The main ring and the pendant-arms in substituted compounds were considered separately. The obtained relaxation rates and NOE factors for N4R4_CO(CH 2) 4CH 3 and N4R4_SO 2C 10H 7 molecules were fitted to overall and internal correlation times and order parameters using Lipari-Szabo 'model-free' formalism. The chemical shift anisotropy was determined for N4R4_SO 2C 10H 7 compound. The meaningful differences were observed between carbons in the main part of molecules and carbons from pendant-arms.

Wyrwa?, Joanna; Schroeder, Grzegorz; Kowalewski, Jozef; Aski, Sahar Nikkhou

2006-07-01

3

Biological evaluation of 153Sm and 166Ho complexes with tetraazamacrocycles containing methylcarboxylate and/or methylphosphonate pendant arms  

International Nuclear Information System (INIS)

153Sm and 166Ho complexes with two series of tetraazamacrocyclic ligands containing methylcarboxylate and/or methylphosphonate pendant arms were synthesized and their charge, lipophilicity, protein binding and in vitro and in vivo behaviour evaluated. The first series has the same backbone, a 14-membered tetraazamacrocycle containing a pyridine unit with different pendant arms, namely methylcarboxylates (ac3py14) or methylphosphonates (MeP2py14 and P3py14). The second series comprises 12- to 14-membered tetraazamacrocycles having methylcarboxylates and/or methylphosphonates as pendant arms (trans-DO2A2P, TRITA, TRITP, TETA and TETP). The 153Sm/166Ho complexes with the 14-membered tetraazamacrocycles containing the pyridine unit are neutral, hydrophilic, have a significant plasmatic protein binding, are unstable in vivo and present a slow rate of radioactivity excretion and high hepatic retention. 153Sm/166Ho complexes with the 12- to 14-membered tetraazamacrocycles are quantitatively prepared, except those with TETP. These complexes are hydrophilic, have an overall negative charge and present a medium to low plasmatic protein binding. The 153Sm/166Ho-trans-DO2A2P, 153Sm/166Ho-TRITA and 166Ho-TRITP complexes are stable in vitro and in vivo, presenting a rapid clearance from main organs and a high rate of whole body rain organs and a high rate of whole body radioactivity excretion. Biological profile of 153Sm/166Ho-TRITA complexes makes them promising candidates for therapy when conjugated to a biomolecule, while 166Ho-TRITP is potentially useful for bone targeting due to its considerable uptake by bone. (orig.)

4

Synthesis and catalytic properties in olefin epoxidation of novel iron(II) complexes with pyridine-containing macrocycles bearing an aminopropyl pendant arm.  

Science.gov (United States)

Three novel iron(II) complexes with pyridine-containing macrocycles bearing an aminopropyl pendant arm were synthesized and characterized. Crystal structures of two of the complexes revealed high-spin iron(II) centers coordinated to the five ligand nitrogen atoms with no coordination of either the solvent molecules or anions, resulting in an unusual square-pyramidal geometry. Related tetradentate ligand CRH formed a low-spin iron(II) complex (meso form was structurally characterized) with a planar arrangement of the four nitrogen atoms from the macrocycle and two axial acetonitrile molecules. Similarly to the corresponding nickel and copper complexes of the pentadentate ligands, the protonation of the amino group on the ligand arm in iron(II) complexes was found to be reversible. Spectral changes and magnetic susceptibility measurements indicated that a change in the geometry and spin state of the metal center is associated with this acid-base process. In the presence of noncoordinating acids (e.g., triflic acid), these complexes, as well as their nonmethylated analogue, can efficiently catalyze the epoxidation of cyclooctene and 1-decene under mild conditions, using hydrogen peroxide as the oxidant. However, in the deprotonated form or in the presence of coordinating acids like HCl, no epoxidation occurs. PMID:17335276

Taktak, Sonia; Ye, Wanhua; Herrera, Aida M; Rybak-Akimova, Elena V

2007-04-01

5

Luminescent cadmium phenylenediacetate coordination polymers with bis(pyridylformyl)piperazine tethers: Influence of pendant arm position on topology  

Science.gov (United States)

Hydrothermal synthesis has generated divalent cadmium coordination polymers containing phenylenediacetate (phda) and bis(4-pyridylformyl)piperazine (bpfp) ligands, in which the position of the pendant acetate arms plays a very significant role in structure direction during self-assembly. [Cd(1,2-Hphda) 2(4-bpfp)] n ( 1) exhibits 2-D polymeric layers with embedded anti-syn bridged [Cd(OCO) 2] n ribbons. {[Cd(1,3-phda)(4-bpfp)(H 2O)] 2} n ( 2) has crystallographically independent (4,4) grids with different carboxylate binding modes, engaged in parallel interpenetration. {[Cd(1,4-phda)(4-bpfp)(H 2O)]} n ( 3) manifests acentric 1-D chains with an uncommon 4-connected 3 34 25 topology instilled by the mismatch in ligand length. Luminescent properties of all phases are also reported.

Wang, Curtis Y.; LaDuca, Robert L.

2010-11-01

6

Synthesis and crystal structure determination of some asymmetrical and symmetrical CR-type macrocyclic Schiff base complexes, with a single pendant coordinating 2-aminoethyl arm.  

Science.gov (United States)

A novel, totally asymmetrical tripodal 2,3',4"-tetraamine ligand, N((CH2)2NH2)((CH2)3NH2)((CH2)4NH2), epb, has been synthesized. In the presence of copper(II) and nickel(II) ions it condenses with 2,6-diacetylpyridine in 1:1 ethanol-water solution, producing some new CR-type complexes with a pendant primary amino group. The X-ray crystal structure of the resulting copper(II) complex, [Cu(3,4(2)-CR)](PF6)2 (1), and two other related complexes, [Cu(2,4(2)-CR)](ClO4)2 (2) and [Cu(3,3(2)-CR)](ClO4)2 (3), are reported. Crystal data: complex 1, monoclinic, P2(1)/n, a = 8.366(3) A, b = 15.549(3) A, c = 20.283(2) A, beta = 98.73(2) degrees, V = 2607.8(11) A3, Z = 4, R1 = 0.0621, wR2 = 0.1615; complex 2, monoclinic, P2(1)/c, a = 7.981(10) A, b = 18.882(3) A, c = 15.185(3) A, beta = 96.40(2) degrees, V = 2275.7(6) A3, Z = 4, R1 = 0.0773, wR2 = 0.1635; complex 3, monoclinic, P2(1)/n, a = 7.8764(10) A, b = 15.361(2) A, c = 19.370(2) A, beta = 100.330(10) degrees, V = 2305.7(5) A3, Z = 4, R1 = 0.0537, wR2 = 0.1397. In all of these, copper atoms are bonded to four nitrogens of a macrocyclic ring and a nitrogen of the pendant arm. The arrangements are slightly distorted square-pyramidal in which the primary amino groups occupy apical positions and have the longest Cu-N distances. For all isomers, copper(II) ions are somewhat above the plane of the imino-pyridine system of the macrocylic ring in the direction of the pendant coordinated primary amino group. PMID:11153507

Keypour, H; Salehzadeh, S; Pritchard, R G; Parish, R V

2000-12-11

7

Distinguishable Zn(II) and Pb(II) template effects on forming pendant-armed Schiff-base macrocyclic complexes including a remarkable Pb(II)-? macrocyclic complex.  

Science.gov (United States)

36-Membered [2 + 2] half-fold Schiff-base macrocyclic dinuclear Zn(II) complexes (1a and 1b) and 18-membered [1 + 1] Schiff-base macrocyclic mononuclear Pb(II) complexes (2 and 3) are produced from the condensation between 1,3-propanediamine and a pair of extended dialdehydes with different functional pendant arms (H2hpdd and H2pdd) because of the distinguishable cationic template effects. It is very interesting to mention that a unique intramolecular Pb(II)-? macrocyclic complex 2 with an uncommon ?(3)-coordination type is achieved under ambient conditions and it can remain stable both in the solid state and in solution. The subtle variations of pendant-arms in the macrocyclic ligands H2hpdd and H2pdd yield different Pb(II) complexes, where the competition between Pb(II)-? and Pb(II)-NO3(-) electrostatic interactions as well as the combination of steric and electronic effects of pendant arms are believed to play important roles. PMID:25188754

Zhang, Kun; Geng, Jiao; Jin, Chao; Huang, Wei

2014-11-01

8

TETA analogue containing one methylenephosphonate pendant arm: Lanthanide complexes and biological evaluation of its 153Sm and 166Ho complexes.  

Science.gov (United States)

The thermodynamic stability constants of complexes of 1,4,8,11-tetraazacyclotetradecane-1,4,8-triacetic-11-methylphosphonic acid (H5te3a1p) with La3+, Sm3+, Gd3+, Ho3+ and Lu3+ metal ions were determined by potentiometric titrations at 298.2 K and with ionic strength 0.10 M in N(CH3)4NO3. The complexes are formed relatively fast and the stability constants exhibited are good although lower than those found for the related ligands H4teta and H8tetp. At physiological pH the completely deprotonated complex species predominate, unlike what happens with the other mentioned ligands. The 153Sm and 166Ho complexes, 153Sm/166Ho-te3a1p, were synthesised quantitatively at pH 9 and 70 °C, and have shown good in vitro stability in human serum and physiological solutions except phosphate buffer (pH 7.4). The in vivo behaviour indicated that both complexes have a similar biological pattern, showing a slow tissue clearance, slow rate of total radioactivity excretion and some in vivo instability, although with some differences in their extend. These results indicate that the replacement of one acetate pendant arm of H4teta by a methylphosphonate one does not provide promising chelators to stabilize radiolanthanides for in vivo application. PMID:20888085

Lima, Luís M P; Delgado, Rita; Marques, Fernanda; Gano, Lurdes; Santos, Isabel

2010-12-01

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Biological evaluation of 153Sm and 166Ho complexes with macrocyclic ligands containing acetate pendant arms as potential agents for therapy  

International Nuclear Information System (INIS)

For the development of therapeutic radiopharmaceuticals it is essential to choose the appropriate beta-emitter as well as the carrier biomolecule. Different carrier biomolecules, namely antibodies and peptides, have been linked to different beta-emitters (153Sm, 166Ho and 177Lu) using tetraaza macrocycles as bifunctional chelators. The cavity size of these chelators, the rigidity of the macrocyclic backbone and the nature of the pendant arms seems to play an important role on the thermodynamic stability and kinetic inertness of the radiocomplexes and on their biological behaviour. In our research group we have been exploring the possibility of using tetraazamacrocycles with different cavity size, pendant arms and rigidity for preparing 153Sm and 166Ho complexes useful for therapeutical applications and/or bone pain palliation. In this communication we present the results obtained when we reacted trita and teta with 153Sm and 166Ho. The complexes are formed in good yields (> 98%), are hydrophilic and present an overall negative charges, as well as low plasmatic protein binding. Good in vitro stability in physiological media and human serum was also found for all the complexes. The biodistribution studies in mice are also presented and have shown that 153Sm/166Ho-trita and 166Ho-teta have rapid tissue clearance, comparably to the corresponding dota complexes. Inly to the corresponding dota complexes. In contrast, 153Sm-teta has a significant lower total excretion and a significant liver and muscle uptake. Our results indicate that 153Sm/166Ho-trita form very stable complexes in vivo. However, teta, which has a larger cavity size, forms less stable complexes with the larger ion Sm3+. The biological profile of 153Sm/166Ho-trita is very interesting for the evaluation of these complexes as therapeutical agents when conjugated to biomolecules

10

Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies  

International Nuclear Information System (INIS)

The current interest in functionalized calixarenes with phosphorylated pendant arms resides in their coordination ability towards f elements and capability towards actinide/rare earth separation. Uranyl cation forms 1:1 and 1:2 (M:L) complexes with a tetra-phosphinoylated p-tert-butylcalix[4]arene, B4bL4: UO2(NO3)2(B4bL4)n . xH2O (n = 1, x = 2, 1; n = 2, x = 6, 2). Spectroscopic data point to the inner coordination sphere of 1 containing one monodentate nitrate anion, one water molecule and the four phosphinoylated arms bound to UO22+ while in 2, uranyl is only coordinated to calixarene ligands. In both cases the U(VI) ion is 8-coordinate. Uranyl complexes display enhanced metal-centred luminescence due to energy transfer from the calixarene ligands; the luminescence decays are bi-exponential with associated lifetimes in the ranges 220 ?s s L 5/2,7/2), O(1s) and P(2p) levels on solid state samples. The extraction study of UO22+ cation and trivalent rare-earth (Y, La, Eu) ions from acidic nitrate media by B4bL4 in chloroform shows the uranyl cation being much more extracted than rare earths. (orig.)are earths. (orig.)

11

Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies  

Energy Technology Data Exchange (ETDEWEB)

The current interest in functionalized calixarenes with phosphorylated pendant arms resides in their coordination ability towards f elements and capability towards actinide/rare earth separation. Uranyl cation forms 1:1 and 1:2 (M:L) complexes with a tetra-phosphinoylated p-tert-butylcalix[4]arene, B{sub 4}bL{sup 4}: UO{sub 2}(NO{sub 3}){sub 2}(B{sub 4}bL{sup 4}){sub n} . xH{sub 2}O (n = 1, x = 2, 1; n = 2, x = 6, 2). Spectroscopic data point to the inner coordination sphere of 1 containing one monodentate nitrate anion, one water molecule and the four phosphinoylated arms bound to UO{sub 2}{sup 2+} while in 2, uranyl is only coordinated to calixarene ligands. In both cases the U(VI) ion is 8-coordinate. Uranyl complexes display enhanced metal-centred luminescence due to energy transfer from the calixarene ligands; the luminescence decays are bi-exponential with associated lifetimes in the ranges 220 {mu}s < {tau}{sub s} < 250 {mu}s and 630 {mu}s < {tau}{sub L} < 640 {mu}s, pointing to the presence of two species with differently coordinated calixarene, as substantiated by a XPS study of U(4f{sub 5/2,7/2}), O(1s) and P(2p) levels on solid state samples. The extraction study of UO{sub 2}{sup 2+} cation and trivalent rare-earth (Y, La, Eu) ions from acidic nitrate media by B{sub 4}bL{sup 4} in chloroform shows the uranyl cation being much more extracted than rare earths. (orig.)

Ramirez, F. de M. [Instituto Nacional de Investigaciones Nucleares, La Marquesa, Ocoyoacac (Mexico). Dept. de Quimica; Varbanov, S. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. of Organic Chemistry with Center of Phytochemistry; Buenzli, J.C.G. [Ecole Polytechnique Federale de Lausanne (EPFL) (Switzerland). Inst. of Chemical Sciences and Engineering; Rivas-Silva, J.F.; Ocana-Bribiesca, M.A. [Instituto de Fisica de la BUAP, Puebla (Mexico); Cortes-Jacome, M.A.; Toledo-Antonio, J.A. [Instituto Mexicano del Petroleo/Programa de Ingenieria Molecular (Mexico)

2012-07-01

12

Lanthanide(III) complexes with a tetrapyridine pendant-armed macrocyclic ligand: 1H NMR structural determination in solution, X-ray diffraction, and density-functional theory calculations.  

Science.gov (United States)

Complexes between the tetrapyridyl pendant-armed macrocyclic ligand (L) and the trivalent lanthanide ions have been synthesized, and structural studies have been made both in the solid state and in aqueous solution. The crystal structures of the La, Ce, Pr, Gd, Tb, Er, and Tm complexes have been determined by single-crystal X-ray crystallography. In the solid state, all the cation complexes show a 10-coordinated geometry close to a distorted bicapped antiprism, with the pyridine pendants situated alternatively above and below the main plane of the macrocycle. The conformations of the two five-membered chelate rings present in the complexes change along the lanthanide series. The La(III) and Ce(III) complexes show a lambdadelta (or deltalambda) conformation, while the complexes of the heavier lanthanide ions present lambdalambda (or deltadelta) conformation. The cationic [Ln(L)]3+ complexes (Ln = La, Pr, Eu, Tb, and Tm) were also characterized by theoretical calculations at the density-functional theory (DFT) B3LYP level. The theoretical calculations predict a stabilization of the lambdalambda (or deltadelta) conformation on decreasing the ionic radius of the Ln(III) ion, in agreement with the experimental evidence. The solution structures show a good agreement with the calculated ones, as demonstrated by paramagnetic NMR measurements (lanthanide induced shifts and relaxation rate enhancements). The 1H NMR spectra indicate an effective D2 symmetry of the complexes in D2O solution. The 1H lanthanide induced shifts (LIS) observed for the Ce(III), Tm(III), and Yb(III) complexes can be fit to a theoretical model assuming that dipolar contributions are dominant for all protons. The resulting calculated values are consistent with highly rhombic magnetic susceptibility tensors with the magnetic axes being coincident with the symmetry axes of the molecule. In contrast with the solid-state structure, the analysis of the LIS data indicates that the Ce(III) complexes present a lambdalambda (or deltadelta) conformation in solution. PMID:16711699

Del C Fernandez-Fernandez, M; Bastida, R; Macías, A; Pérez-Lourido, P; Platas-Iglesias, C; Valencia, L

2006-05-29

13

Synthesis, Cu(II) complexation, 64Cu-labeling and biological evaluation of cross-bridged cyclam chelators with phosphonate pendant arms.  

Science.gov (United States)

A new class of cross-bridged cyclam-based macrocycles featuring phosphonate pendant groups has been developed. 1,4,8,11-tetraazacyclotetradecane-1,8-di(methanephosphonic acid) (CB-TE2P, 1) and 1,4,8,11-tetraazacyclotetradecane-1-(methanephosphonic acid)-8-(methanecarboxylic acid) (CB-TE1A1P, 2) have been synthesized and have been shown to readily form neutral copper(II) complexes at room temperature as the corresponding dianions. Both complexes showed high kinetic inertness to demetallation and crystal structures confirmed complete encapsulation of copper(II) ion within each macrocycle's cleft-like structure. Unprecedented for cross-bridged cyclam derivatives, both CB-TE2P (1) and CB-TE1A1P (2) can be radiolabeled with (64)Cu at room temperature in less than 1 h with specific activities >1 mCi ?g(-1). The in vivo behavior of both (64)Cu-CB-TE2P and (64)Cu-CB-TE1A1P were investigated through biodistribution studies using healthy male Lewis rats. Both new compounds showed rapid clearance with similar or lower accumulation in non-target organs/tissues when compared to other copper chelators including CB-TE2A, NOTA and Diamsar. PMID:22170043

Ferdani, Riccardo; Stigers, Dannon J; Fiamengo, Ashley L; Wei, Lihui; Li, Barbara T Y; Golen, James A; Rheingold, Arnold L; Weisman, Gary R; Wong, Edward H; Anderson, Carolyn J

2012-02-21

14

Synthesis, Cu(II) complexation, 64Cu-labeling and biological evaluation of cross-bridged cyclam chelators with phosphonate pendant arms  

Science.gov (United States)

A new class of cross-bridged cyclam-based macrocycles featuring phosphonate pendant groups has been developed. 1,4,8,11-tetraazacyclotetradecane-1,8-di(methanephosphonic acid) (CB-TE2P, 1) and 1,4,8,11-tetraazacyclotetradecane-1-(methanephosphonic acid)-8-(methanecarboxylic acid) (CB-TE1A1P, 2) have been synthesized and have been shown to readily form neutral copper (II) complexes at room temperature as the corresponding dianions. Both complexes showed high kinetic inertness to demetallation and crystal structures confirmed complete encapsulation of copper (II) ion within each macrocycle’s cleft-like structure. Unprecedented for cross-bridged cyclam derivatives, both CB-TE2P (1) and CB-TE1A1P (2) can be radiolabeled with 64Cu at room temperature in less than 1 hour with specific activities >1mCi/?g. The in vivo behavior of both 64Cu-CB-TE2P and 64Cu-CB-TE1A1P were investigated through biodistribution studies using healthy, male, Lewis rats. Both new compounds showed rapid clearance with similar or lower accumulation in non-target organs/tissues when compared to other copper chelators including CB-TE2A, NOTA and Diamsar. PMID:22170043

Ferdani, Riccardo; Stigers, Dannon J.; Fiamengo, Ashley L.; Wei, Lihui; Li, Barbara T. Y.; Golen, James A.; Rheingold, Arnold L.; Weisman, Gary R.; Wong, Edward H.; Anderson, Carolyn J.

2012-01-01

15

X-ray structural study of lanthanide complexes with a p- tert-butylthiacalix[4]arene bearing phosphoryl pendant arms  

Science.gov (United States)

A new lower-rim substituted thiacalix[4]arene, 5,11,17,23-tetra- tert-butyl-25,26,27,28-tetrakis(diphenylphosphinoylmethoxy) thiacalix[4]arene ( L) has been synthesized and structurally characterized as an adduct L·0.5MeOH·1.5H 2O, monoclinic, space group P2 1/n . The ligand adopts a cone conformation. Trivalent lanthanide ion complexes of this ligand have been synthesized and characterized by elemental analysis and IR spectra. The crystal structures of La 3+ and Nd 3+ complexes were determined by X-ray diffraction method. They are isostructural and belong to tetragonal system, I4 1/acd space group. In each complex, the calixarene retains the cone conformation, the metal ion is nine-coordinated to four oxygen atoms from phosphine oxide substituents, four oxygen atoms from two bidentate nitrate anions and one oxygen atom from a hydroxyl ion. The coordination polyhedron is a single-capped square antiprism. The complex assembles to a novel infinitely 1D helical structure through ?-? stacking, and further crosses each other forming a nanometer scale chessboard-like pore structure along c direction.

Guo, Qian-Ling; Yuan, Da-Qiang; Ma, Shu-Lan; Liu, Ying-Chun; Zhu, Wen-Xiang

2005-10-01

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Synthesis and characterization of Ni(II, Cu(II and Co(III complexes with polyamine-containing macrocycles bearing an aminoethyl pendant arm  

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Full Text Available Reaction of [M(ppn2]X2 (where M = Cu(II, Ni(II, Co(II and ppn = 1,3-diaminopropane with formaldehyde and ethylenediamine in methanol results in the ready formation of a 16-membered macrocyclic complex. The complexes were characterized by elemental anlysis, IR, EPR, electronic spectral data, magnetic moments and conductance measurements. The Cu(II, Ni(II and Co(III complexes are coordinated axially with both pendant groups of the hexadentate macrocycle. These pendant donors are attached to the macrocycle by a carbon chain. The electrical conductivities of the Cu(II and Ni(II chelates indicated them to be 1:2 electrolytes whilst those of Co(III is a 1:3 electrolyte in DMSO. The EPR spectrum of the copper complex exhibited G at 3.66, which indicates a considerable exchange interaction in the complex. Spectroscopic evidence suggests that in all of the complexes the metal ion is in an octahedral environment.

K. S. SIDDIQI

2004-09-01

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Synthesis of luminescent homo-dinuclear cationic lanthanide cyclen complexes bearing amide pendant arms through the use of copper catalysed (1,3-Huisgen, CuAAC) click chemistry.  

Science.gov (United States)

The design and synthesis of dinuclear-lanthanide complexes possessing triazole-based bridges, formed by using copper catalysed 1,3-cycloaddition reactions between heptadentate alkyne functionalised cyclen europium or terbium complexes and di-azides (CuAAC reactions), are described. While this click reaction worked well for the formation of the homo-Eu(III) and Tb(III) bis-tri-arm cyclen N,N-dimethyl acetamide complexes, 2Eu and 2Tb, and for the homo-Eu(III) chiral N-methylnaphthalene based complexes 3Eu (S,S,S) and 4Eu (R,R,R), the formation of the Eu(III) complex of the primary amide analogue of 2, namely 1Eu, was not successful, clearly demonstrating the effect that the nature of the pendant arms has on this reaction. Furthermore, the click reactions between the free alkyne cyclen bis-derivatives (5-8) and the di-azide were unsuccessful, most likely due to the high affinity of the cyclen macrocycles for Cu(II). The Eu(III) complexes of 2-4 and 2Tb all gave rise to sensitised metal ion centred emission upon excitation of the triazole or the naphthalene antennae in methanol solution, and their hydration states were determined, which showed that while the Eu(III) mono-nuclear complexes had q ? 2, the click products all had q ? 1. In the case of 3Eu (S,S,S) and 4Eu (R,R,R), the circular polarised emission (CPL) was also observed for both, demonstrating the chiral environment of the lanthanide centres. PMID:22071980

Molloy, Jennifer K; Kotova, Oxana; Peacock, Robert D; Gunnlaugsson, Thorfinnur

2012-01-14

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Polyisobutylene-based mikto-arm star polymers synthesized via quasiliving cationic polymerization and atom transfer radical polymerization  

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This research pertains to the synthesis of mikto-arm star polymers created via quasiliving cationic polymerization (QCP) and atom transfer radical polymerization (ATRP). The first part of this work focuses on the synthesis of cationic initiators that contain latent functionalities for initiation of ATRP polymerizations. In the second part of this work, well-defined copolymers of polyisobutylene (PIB) and polystyrene (PS) were created by cationic polymerization. After transformation of the initiating site, poly(tert-butyl acrylate) (PtBA) was synthesized via ATRP. This block was later hydrolyzed to form poly(acrylic acid) (PAA), which serves as a hydrophilic segment of the material. The polymers had narrow PDIs and target polymer compositions. However, molecular weights were higher than expected when low molecular weight polymers were targeted. This is attributed to a complexation between the Lewis acid, titanium tetrachloride (TiCl4), and the carbonyl group in the initiators.

Breland, Lesli Krystin

19

Facilitated photoreduction of ruthenium bis(4'-methylterpyridine) pendant myoglobin  

International Nuclear Information System (INIS)

A synthetic heme bearing ruthenium bis(terpyridine) through a covalent bond was successfully prepared. Ruthenium bis(terpyridine) pendant myoglobin, which was synthesized by a conventional cofactor reconstitution method, was efficiently activated through a photoinduced electron-transfer reaction from the ruthenium complex to the heme center. No reaction occurred in the corresponding intermolecular reaction system. (author)

20

Transannular oscillation of metal centers in the pendant arm macrocyclic complex [1,4,8,11-tetrakis(2-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane]mercury(II) and its lead(II) analogue. NMR study of the 13C natural abundance and specifically enriched complexes  

International Nuclear Information System (INIS)

A 13C NMR study of [1,4,8,11-tetrakis(2-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane]mercury(II) and its lead(II) analogue, [M(THEC)]2+ (M = Hg, Pb), in CD3OD, shows that the most probable structure of these complexes in solution incorporates the 1,4,8,11-tetraazacyclotetradecane ring in the trans III configurations with the metal center above the tetraaza plane and trigonal-prismatically coordinated by four ring nitrogens and two hydroxyethyl pendant arms attached to either end of the same 1,3-diaminopropane moiety. Dynamic 13C NMR studies of [M(THEC)]2+ are consistent with a rapid pairwise intramolecular exchange of the hydroxyethyl arms between mono- and bidentate coordination simultaneously with the oscillation of M(II) through the macrocyclic annulus of THEC. This pairwise exchange of the hydroxyethyl arms is characterized by k(298.2 K) = 3,130 ± 120 and 11,220 ± 200 s-1, ?H double-dagger = 38.0 ± 0.6 and 45.4 ± 0.3 kJ mol-1, and ?S double-dagger = -50.6 ± 2.1 and -15.2 ± 1.1 J K-1 mol-1, respectively, for M = Hg and Pb. 24 refs., 8 figs., 1 tab

 
 
 
 
21

Carbon-13 and cadmium-113 nuclear magnetic resonance evidence for a novel transannular oscillation of cadmium(II) in the pendant arm macrocyclic complex [1,4,8,11-tetrakis(2-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane]cadmium(II)  

International Nuclear Information System (INIS)

A 13C NMR study of [1,4,8,11-tetrakis(2-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane]cadmium(II), [Cd(THEC)]2+, in CD3OD shows that the most probable structure for [Cd(THEC)]2+ incorporates the 1,4,8,11-tetraazacyclotetradecane ring in the trans III configuration. In this structure Cd(II) is above the tetraaza plane and is trigonal-prismatically coordinated by four ring nitrogens and two hydroxyethyl pendant arms attached to either end of the same 1,3-diaminopropane moiety. The 13C CPMAS NMR spectrum of solid [Cd(THEC)]2+ is also consistent with this structure. Dynamic 13C NMR studies of natural abundance [Cd(THEC)]2+ and of [Cd(THEC)]2+ in which both carbons of each of the hydroxyethyl arms are 99 atom % enriched in 13C are consistent with a rapid oscillation of Cd(II) through the macrocyclic annulus of THEC. The 13C-enriched hydroxyethyl arms are characterized by 13C AB quartets under conditions of slow exchange but show a novel coalescence to a singlet under fast-exchange conditions consistent with the relative chemical shifts of the methylene carbons of the hydroxyethyl arm being reversed when it changes from the mono- to the bidentate coordination state. The pairwise exchange of the hydroxyethyl arm between the monodentate and bidentate environments is characterized by k(298.2 K) = 34,200 ± 1,800 s-1, ?H double-dagger = 44.00 ± 0.56 kJ mol-1, and ?S double-dagger = -10.6 ± 2.2 J K-1 mol-1. 13C and 113Cd NMR spectra show that intermolecular THEC and Cd(II) exchange on [Cd(THEC)]2+ is a much slower process. 29 refs., 6 figs

22

Quadrangulations with no pendant vertices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We prove that the metric space associated with a uniformly distributed planar quadrangulation with n faces and no pendant vertices converges modulo a suitable rescaling to the Brownian map. This is a first step towards the extension of recent convergence results for random planar maps to the case of graphs satisfying local constraints.

Beltran, Johel; Gall, Jean-franc?ois Le

2013-01-01

23

Polyimides with pendant alkyl groups  

Science.gov (United States)

The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed.

Jensen, B. J.; Young, P. R.

1982-01-01

24

Ultrasonic Vibration Suspends Large Pendant Drops  

International Nuclear Information System (INIS)

A stationary substrate can suspend only small pendant drops even with excellent wetting ability because of gravity. We report the suspension of large pendant water drops by a copper substrate that vibrates ultrasonically with a frequency of 22 kHz. The mass of the largest pendant drop suspended by the vibrating substrate reaches 1.1 g, which is 9 times that by the same stationary substrate. The pendant drop deforms drastically and quickly at both the beginning and the end of the vibration procedure. As the vibration power increases, the contact area between the drop and substrate expands and the drop height shrinks accordingly. Theoretical analysis indicates that the Bernoulli pressure induced by ultrasonic vibration may contribute strongly to enhancing the suspensibility of pendant drops. (fundamental areas of phenomenology(including applications))

25

Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups  

Directory of Open Access Journals (Sweden)

Full Text Available (±-10-Methacryloyloxycamphorquinone (MCQ was synthesized from (±-10-camphorsulfonic acid either by a known seven-step synthetic route or by a novel, shorter five-step synthetic route. MCQ was copolymerized with styrene (S and the photochemical behavior of the copolymer MCQ/S was compared with that of a formerly studied copolymer of styrene with monomers containing the benzil (BZ moiety (another 1,2-dicarbonyl. Irradiation (? > 380 nm of aerated films of styrene copolymers with monomers containing the BZ moiety leads to the insertion of two oxygen atoms between the carbonyl groups of BZ and to the formation of benzoyl peroxide (BP as pendant groups on the polymer backbone. An equivalent irradiation of MCQ/S led mainly to the insertion of only one oxygen atom between the carbonyl groups of camphorquinone (CQ and to the formation of camphoric anhydride (11 covalently bound to the polymer backbone. While the decomposition of pendant BP groups formed in irradiated films of styrene copolymers with pendant BZ groups leads to crosslinking, only small molecular-weight changes in irradiated MCQ/S were observed.

Branislav Husár

2012-03-01

26

Synthesis and ATRP of novel fluorinated aromatic monomer with pendant sulfonate group  

DEFF Research Database (Denmark)

Novel, fluorinated monomer with pendant sulfonate group was synthesized utilizing a two-step derivatization of 2,3,4,5,6-pentafluorostyrene (FS). The first step was a nucleophilic substitution of the fluorine atom in para position by hydroxyl group followed by sulfopropylation. The monomer was polymerized under aqueous ATRP conditions to yield phenyl-fluorinated aromatic homopolymer bearing pendant sulfonates on each repeating unit. Furthermore, this polymer was used as macroinitiator for the ATRP of poly(ethylene glycol) methacrylate. The polymers were characterized by 1H NMR, SEC and FTIR analyses. Their thermal properties were evaluated by differential scanning calorimetry and thermal gravimetric analyses.

Dimitrov, Ivaylo; Jankova Atanasova, Katja

2013-01-01

27

Hysteresis in forced oscillations of pendant drops  

International Nuclear Information System (INIS)

A hysteresis phenomenon has been revealed through experiments conducted with large-amplitude forced oscillations of pendant drops in air. Under strong excitation, the frequency response of a drop forced at constant amplitude exhibits jump behavior; a larger peak response amplitude ?? appears at a lower frequency ?? during a downward (?) variation of forcing frequency than during an upward (?) variation, viz. ??>?? and ???. Similar results are obtained when forcing amplitude is varied at constant frequency. This behavior is characteristic of a system with a soft nonlinearity. These findings indicate that oscillating pendant drops constitute a convenient system for studying nonlinear dynamics

28

55Cobalt complexes with pendant carbohydrates as potential PET imaging agents  

International Nuclear Information System (INIS)

Bis-ligand cobalt(II) complexes of four 3-hydroxy-4-pyridinone ligands with pendant carbohydrates were synthesized and examined for their potential as radiopharmaceuticals. Non-radioactive complexes were prepared on the macroscopic scale and characterized by elemental analysis, mass spectrometry, IR and UV/visible spectroscopy. Facile radiolabeling produced the 55Co complexes in high radiochemical yields (>95%). Identification of the radiolabeled compounds was accomplished by HPLC comparison with the corresponding non-radioactive complexes

29

A novel poly(aryl ether) containing azobenzene chromophore and pendant oligoaniline: Synthesis and electrochromic properties  

International Nuclear Information System (INIS)

Graphical abstract: This work describes a novel poly(aryl ether) functionalized with azobenzene chromophore and pendant oligoaniline, that exhibits a satisfied electrochromic properties with high contrast value, good coloration efficiency, moderate switching times and acceptable stability. - Abstract: A novel poly(aryl ether), containing pendant oligoaniline and azobenzene moieties (Azo-PAE-p-OA), was synthesized by nucleophilic polycondensation. The structures were confirmed spectroscopically via nuclear magnetic resonance (NMR) and Fourier-transform infrared spectra (FTIR), morphological data was ascertained via X-ray diffraction (XRD), and the thermal stability was probed via thermogravimetric analysis (TGA). Due to the coexistence of oligoaniline and azobenzene groups, Azo-PAE-p-OA shows reversible electroactivity and expectable photoresponse to light irradiation, chemical redox and electrochemical modulation. The electrochromic performance of a Azo-PAE-p-OA film on indium tin oxide (ITO) was investigated by spectrochronoamperometry, and exhibited electrochromic properties with high contrast value, good coloration efficiency, moderate switching times, and acceptable stability.

30

Thermally Stable Perfluorinated Polyimides with Pendant Perfluorinated Aromatic Unit for Photonic Applications  

Science.gov (United States)

We have designed and synthesized novel thermally stable perfluorinated polyimides with pendant perfluorinated aromatic unit for photonic applications. At first, we developed a new synthetic route to a perfluorinated aromatic diamine by protecting-deprotecting as well as by nucleophilic bromine displacement reactions, affording a new diamine with a pendant perfluorinated aromatic unit. Its chemical structure was identified by 1H-, 19F- and 13C-NMR spectroscopies as well as mass spectrometry. Novel fluorinated polyimides were prepared by condensation polymerization of the present fluorinated diamine with various dianhydrides. The resultant polyimides are thermally stable over 400°C. The refractive index and birefringence of the resultant polyimides are 1.5844 ~ 1.5040 and 0.01 ~ 0.03 at 633 nm, respectively.

Park, Jin Kyu; Song, Bok Ju; Lee, Dong-Hun; Song, Young-Bae; Oh, Jae Buem; Hong, Ji-Sook; Kim, Hwan Kyu

31

Synthesis and characterization of novel liquid crystalline polymers containing cholesteryl pendant groups  

Energy Technology Data Exchange (ETDEWEB)

In order to investigate the chiral effect of cholesteryl pendant groups on the induction of the cholesteric phase, a new cholesteryl-containing liquid crystalline monomer was synthesized and copolymerized with an achiral comonomer in various molar ratios. The layer-like arrangement of the smectic mesophase with different monomeric compositions of copolymers was investigated using an X-ray diffraction analysis. The cholesteric liquid phase was induced by the chiral segments; the dependence of the reciprocal central reflection wavelength on the mole fraction of the chiral monomer for copolymers was investigated. This paper demonstrates the effect of chiral pendant groups on the induction of the cholesteric phase and layered molecular arrangement of side-chain liquid crystalline polymers.

Liu, Jui-Hsiang, E-mail: jhliu@mail.ncku.edu.tw [Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Hsieh, Feng-Ming [Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China)

2009-12-15

32

Thermoresponsiveness of Copolymers Bearing Cholic Acid Pendants Induced by Complexation with ?-Cyclodextrin.  

Science.gov (United States)

Copolymers of N-alkylacrylamides and methacrylate bearing cholic acid pendant groups were synthesized via radical polymerization. The cholic acid pendant groups of such copolymers can form complexes with ?-cyclodextrin, and the effect of complexation on their thermoresponsive properties was studied. The phase transition temperatures (transition from hydrophilic to hydrophobic state) of the copolymers gradually increase with the addition of ?-cyclodextrin, due to the complexation of the cholic acid guest with the ?-cyclodextrin host. The increase of the phase transition temperature may be reversed by the addition of a competing guest molecule, potassium 1-adamantylcarboxylate. The host-guest complexation provides a straightforward way to vary the thermoresponsive properties of such copolymers. PMID:25203396

Jia, Yong-Guang; Zhu, X X

2014-10-01

33

Synthesis and characterization of novel liquid crystalline polymers containing cholesteryl pendant groups  

International Nuclear Information System (INIS)

In order to investigate the chiral effect of cholesteryl pendant groups on the induction of the cholesteric phase, a new cholesteryl-containing liquid crystalline monomer was synthesized and copolymerized with an achiral comonomer in various molar ratios. The layer-like arrangement of the smectic mesophase with different monomeric compositions of copolymers was investigated using an X-ray diffraction analysis. The cholesteric liquid phase was induced by the chiral segments; the dependence of the reciprocal central reflection wavelength on the mole fraction of the chiral monomer for copolymers was investigated. This paper demonstrates the effect of chiral pendant groups on the induction of the cholesteric phase and layered molecular arrangement of side-chain liquid crystalline polymers.

34

Amphiphilic diblock copolymer with dithienylethene pendants: synthesis and photo-modulated self-assembly.  

Science.gov (United States)

In this work, an amphiphilic diblock copolymer (PEG(43)-b-PSDTE(29)) bearing photochromic dithienylethene (DTE) pendants is synthesized by reversible addition fragmentation chain transfer radical polymerization. The diblock copolymer was characterized by spectroscopic methods and gel permeation chromatography. The analyses proved the well-defined structure and narrow molecular weight distribution of the diblock copolymer. The DTE pendants could undergo reversible photoisomerization between their open and closed forms in solution when irradiated with UV and visible light as indicated by (1)H NMR and UV-vis spectroscopy. Hollow vesicle-like structures were formed by gradually adding deionized water to the colorless PEG(43)-b-PSDTE(29open) (DTE in open form) tetrahydrofuran solution. Under the same conditions, the aggregates formed in the blue PEG(43)-b-PSDTE(29close) (DTE in closed form) solution were colloidal spheres with solid interiors. The isomerization of DTE pendants could cause the deformation of the vesicle-like structures. The above results demonstrate a kind of novel photo-modulated self-assembly behavior of the amphiphilic diblock copolymer, which could be used for drug-delivery and other applications. PMID:21574201

Chen, Zhen; He, Yaning; Wang, Yang; Wang, Xiaogong

2011-07-01

35

Synthesis and antioxidative activity of metalloporphyrins bearing 2,6-di-tert-butylphenol pendants.  

Science.gov (United States)

The novel metalloporphyrins (M=HH, Fe, Mn, Co, Cu, Zn) bearing 2,6-di-tert-butylphenol pendants as antioxidant substituents, and a long chain hydrocarbon palmitoyl group have been synthesized. The oxidation of compounds by PbO2 leads to the formation of the corresponding 2,6-di-tert-butylphenoxyl radicals studied by EPR. The activity of porphyrins in lipid peroxidation has been examined using (1) in vitro lipid peroxidation induced by tert-butylhydroperoxide in respiring rat liver mitochondria, (2) in vitro lipid peroxidation in liver homogenates of Wistar strain rats, and (3) a model process of peroxidation of (Z)-octadec-9-enic (oleic) acid as a structural fragment of lipids. The activity of these compounds depends dramatically on the nature of metal and might be changed from antioxidative (M=HH, Mn, Cu, Zn) to indifferent (M=Co), and to pro-oxidative one (M=Fe). The anti- or pro-oxidative action of these compounds may be derived from the concurrence between the involvement of 2,6-di-tert-butylphenol pendants acting as radical scavengers and redox active metal center promoting oxidation processes. The results of this study suggest that the polytopic compounds combining in one molecule 2,6-di-tert-butylphenol pendants, metalloporphyrin moiety, and a palmitoyl group, are membrane active compounds and might be studied in an effort to find novel pharmaceutical agents. PMID:18321586

Milaeva, E R; Gerasimova, O A; Jingwei, Zhang; Shpakovsky, D B; Syrbu, S A; Semeykin, A S; Koifman, O I; Kireeva, E G; Shevtsova, E F; Bachurin, S O; Zefirov, N S

2008-01-01

36

The Stability of Two Connected Pendant Drops  

Science.gov (United States)

The stability of an equilibrium system of two drops suspended from circular holes is examined. The drop surfaces are disconnected surfaces of a connected liquid body. For holes of equal radii and identical pendant drops axisymmetric perturbations are always the most dangerous. The stability region for two identical drops differs considerably from that for a single drop. Loss of stability leads to a transition from a critical system of identical drops to a stable system of axisymmetric non-identical. This system of non-identical drops reaches its own stability limit (to isochoric or non-isochoric paturbations). For non-identical drops, loss of stability results in dripping or streaming from the holes. Critical volumes for non-identical drops have been calculated as functions of the Bond number, B. For unequal hole radii, stability regions have been constructed for a set of hole radius, K. The dependence of critical volumes on K and B is analyzed.

Slobozhanin, Lev A.; Alexander, J. Iwan

2004-01-01

37

Remote Neural Pendants In A Welding-Control System  

Science.gov (United States)

Neural network integrated circuits enhance functionalities of both remote terminals (called "pendants") and communication links, without necessitating installation of additional wires in links. Makes possible to incorporate many features into pendant, including real-time display of critical welding parameters and other process information, capability for communication between technician at pendant and host computer or technician elsewhere in system, and switches and potentiometers through which technician at pendant exerts remote control over such critical aspects of welding process as current, voltage, rate of travel, flow of gas, starting, and stopping. Other potential manufacturing applications include control of spray coating and of curing of composite materials. Potential nonmanufacturing uses include remote control of heating, air conditioning, and lighting in electrically noisy and otherwise hostile environments.

Venable, Richard A.; Bucher, Joseph H.

1995-01-01

38

Polyphenylquinoxalines containing pendant phenylethynyl and ethynyl groups. [for thermoplastic resins  

Science.gov (United States)

Poly(phenylquinoxaline) prepolymers containing pendant phenylethynyl and ethynyl groups are disclosed along with the process for forming these polymers. Monomers and the process for producing same that are employed to prepare the polymers are also disclosed.

Hergenrother, P. M. (inventor)

1983-01-01

39

Conjugated polymer network films of poly(p-phenylene vinylene) with hole-transporting carbazole pendants: dual photoluminescence and electrochromic behavior.  

Science.gov (United States)

A series of poly(p-phenylene vinylene) (PPV) copolymers functionalized with hole-transport and electrochemically active carbazole units as pendant moieties is reported. These polymers exhibit photoluminescence properties by virtue of the PPV analogous backbone. They were also designed as precursor polymer bearing the electroactive carbazole group to form conjugated polymer network (CPN) films by electrodeposition. The electrochemical polymerization of the pendant units eventually lead to a dual property electro-optically active thin film - photoluminescence (PL) behavior that can be attenuated with CPN formation, and a reversible doping and dedoping processes at controlled potentials that lead to an electrochromic behavior. This reveals the ability to incorporate complementary optical and electro-optical properties within the same film using the CPN approach. It should be possible to design and synthesize other PPV ?-conjugated polymers with efficient pendant hole-transport groups exhibiting tunable PL and electrochromism with cross-linking. PMID:22329863

Ponnapati, Ramakrishna; Felipe, Mary Jane; Muthalagu, Vetrichelvan; Puno, Katherine; Wolff, Birte; Advincula, Rigoberto

2012-03-01

40

Polythiophenes Comprising Conjugated Pendants for Polymer Solar Cells: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available Polythiophene (PT is one of the widely used donor materials for solution-processable polymer solar cells (PSCs. Much progress in PT-based PSCs can be attributed to the design of novel PTs exhibiting intense and broad visible absorption with high charge carrier mobility to increase short-circuit current density (Jsc, along with low-lying highest occupied molecular orbital (HOMO levels to achieve large open circuit voltage (Voc values. A promising strategy to tailor the photophysical properties and energy levels via covalently attaching electron donor and acceptor pendants on PTs backbone has attracted much attention recently. The geometry, electron-donating capacity, and composition of conjugated pendants are supposed to be the crucial factors in adjusting the conformation, energy levels, and photovoltaic performance of PTs. This review will go over the most recent approaches that enable researchers to obtain in-depth information in the development of PTs comprising conjugated pendants for PSCs.

Hsing-Ju Wang

2014-03-01

 
 
 
 
41

Ionic polymer cluster energetics: Computational analysis of pendant chain stiffness and charge imbalance  

International Nuclear Information System (INIS)

In recent years there has been considerable study of the potential mechanisms underlying the electromechanical response of ionic-polymer-metal composites. The most recent models have been based on the response of the ion-containing clusters that are formed when the material is synthesized. Most of these efforts have employed assumptions of uniform ion distribution within spherical cluster shapes. This work investigates the impact of dispensing with these assumptions in order to better understand the parameters that impact cluster shape, size, and ion transport potential. A computational micromechanics model applying Monte Carlo methodology is employed to predict the equilibrium state of a single cluster of a solvated ionomeric polymer. For a constant solvated state, the model tracks the position of individual ions within a given cluster in response to ion-ion interaction, mechanical stiffness of the pendant chain, cluster surface energy, and external electric-field loading. Results suggest that cluster surface effects play a significant role in the equilibrium cluster state, including ion distribution; pendant chain stiffness also plays a role in ion distribution but to a lesser extent. Moreover, ion pairing is rarely complete even in cation-rich clusters; this in turn supports the supposition of the formation of anode and cathode boundary layers

42

Tricarbonylrhenium complexes from 2-pyridyl-1,2,3-triazole ligands bearing a 4-substituted phenyl arm: a combined experimental and theoretical study.  

Science.gov (United States)

Three new pyridyltriazole ligands (named pyta) bearing a 4-substituted phenyl arm (nitro- (2a), chloro- (2b) or aminophenyl (2c) moiety) have been synthesized using a convenient click chemistry strategy. The corresponding tricarbonylrhenium complexes 3a, 3b and 3c were prepared and fully characterized by means of NMR, IR and mass spectrometry, as well as X-ray crystallography for two of them (3a and 3b). The direct connection of a 4-substituted phenyl arm at the N1 position of the triazolyl ring has a significant influence on the geometry of both, the ligands and their corresponding Re-complexes. The dominant structural feature of these complexes concerns the crystal cohesion. Slip-stacked ?-? interactions between two molecules of the complex were observed for 3a and 3b probably resulting from the co-planarity of the organic framework. Furthermore, a combined experimental study and DFT calculations showed that the nature of the pendant arm (X = NO2, NH2 or Cl) could affect the electronic properties of the Re-complexes. If the chloro- or aminophenyl moieties unmodified the photo-physical properties of the complexes 3b and 3c, the presence of a nitrophenyl arm for the complex 3a quenched the luminescence, due to a high probability of non-radiative deactivation. PMID:23515521

Wolff, Mariusz; Munoz, Luc; François, Alison; Carrayon, Chantal; Seridi, Achour; Saffon, Nathalie; Picard, Claude; Machura, Barbara; Benoist, Eric

2013-05-21

43

Protonation Studies of a Tungsten Dinitrogen Complex Supported by a Diphosphine Ligand Containing a Pendant Amine  

Energy Technology Data Exchange (ETDEWEB)

Treatment of trans-[W(N2)2(dppe)(PEtNMePEt)] (dppe = Ph2PCH2CH2PPh2; PEtNMePEt = Et2PCH2N(Me)CH2PEt2) with three equivalents of tetrafluoroboric acid (HBF4?Et2O) at -78 °C generated the seven-coordinate tungsten hydride trans-[W(N2)2(H)(dppe)(PEtNMePEt)][BF4]. Depending on the temperature of the reaction, protonation of a pendant amine is also observed, affording trans-[W(N2)2(H)(dppe)(PEtNMe(H)PEt)][BF4]2, with formation of the hydrazido complex, [W(NNH2)(dppe)(PEtNMe(H)PEt)][BF4]2, as a minor product. Similar product mixtures were obtained using triflic acid (HOTf). Upon acid addition to the carbonyl analogue, cis-[W(CO)2(dppe)(PEtNMePEt)], the seven-coordinate carbonyl-hydride complex, trans-[W(CO)2(H)(dppe)(PEtN(H)MePEt)][OTf]2 was generated. The mixed diphosphine complex without the pendant amine in the ligand backbone, trans-[W(N2)2(dppe)(depp)] (depp = Et2P(CH2)3PEt2), was synthesized and treated with HBF4?Et2O, selectively generating a hydrazido complex, [W(NNH2)(F)(dppe)(depp)][BF4]. Computational analysis was used to probe proton affinity of three sites of protonation, the metal, pendant amine, and N2 ligand in these complexes. Room temperature reactions with 100 equivalents of HOTf produced NH4+ from reduction of the N2 ligand (electrons come from W). The addition of 100 equivalents HOTf to trans-[W(N2)2(dppe)(PEtNMePEt)] afforded 0.88 ± 0.02 equivalents NH4+, while 0.36 ± 0.02 equivalents of NH4+was formed upon treatment of trans-[W(N2)2(dppe)(depp)], the complex without the pendant amine. This work was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences. Computational resources were provided by the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory. Pacific Northwest National Laboratory is operated by Battelle for DOE.

Weiss, Charles J.; Egbert, Jonathan D.; Chen, Shentan; Helm, Monte L.; Bullock, R. Morris; Mock, Michael T.

2014-05-12

44

Communications: Wall free capillarity and pendant drop removal  

Science.gov (United States)

When a sessile drop encounters a pendant drop through a hole, it is generally anticipated that they will coalesce and flow downward due to gravity. However, like "wall-free" capillarity, we show that the pendant drop may be sucked up by a sliding drop instantaneously if the radius of the curvature of the former is smaller than that of the later. This phenomenon can be explained by Laplace-Young equation and convective Ostwald ripening. Our results indicate that superhydrophilic perforated surface can be used as an effective way for the removal of small droplets adhering to the inner walls of microchannel systems.

Hong, Siang-Jie; Chang, Feng-Ming; Chan, Seong Heng; Sheng, Yu-Jane; Tsao, Heng-Kwong

2010-04-01

45

Novel poly (arylene-ether-ether-ketone)s containing preformed imide unit and pendant long chain alkyl group  

International Nuclear Information System (INIS)

The studies were carried out to get preformed imide unit containing PEEKs and Co-PEEKs with pendant long chain alkyl group. Thus two new bisphenols; N,N'-bis (4-hydroxy 2-pentadecyl phenyl) pyromellitimide (HPI) (I) and N,N'-bis (4-hydroxy 2-pentadecyl phenyl 3,3',4,4'-benzophenone tetracarboxylic imide (HBI) (II) containing imide unit, pendant C-15 alkyl substituents were synthesized, characterized by spectral data and polycondensed with 4,4'-difluorobenzophenone (DFB) to yield several PEEK and Co-PEEKs. The polymers were characterized by FTIR, inherent viscosity, solubility, and XRD. The polymers were obtained in good yields and had inherent viscosities up to 0.65 dL/g in NMP. Polymerization of mixture of two bisphenols; [(I) and BPA]; and [(II) and BPA] in various mol%, with DFB gave number of the copolymers viz. Co-PEEK-BPAPI and Co-PEEK-BPABI. Many of the Co-PEEKs had good solubility in polar solvents. The solubility of PEEK containing bulky pendant alkyl substituents did not much improve probably due to simultaneous presence of rigid imide structures. XRD analysis indicated that PEEK and Co-PEEKs were partially crystalline or amorphous depending on the nature and % content of imide-bisphenol. These new PEEK materials can be used as high performance films, coatings, gas separation membranes, in aerospace and nuclear industries.

46

Pendant-Drop Surface-Tension Measurement On Molten Metal  

Science.gov (United States)

Method of measuring surface tension of molten metal based on pendant-drop method implemented in quasi-containerless manner and augmented with digital processing of image data. Electrons bombard lower end of sample rod in vacuum, generating hanging drop of molten metal. Surface tension of drop computed from its shape. Technique minimizes effects of contamination.

Man, Kin Fung; Thiessen, David

1996-01-01

47

Facile synthesis and characterization of novel biodegradable amphiphilic block copolymers bearing pendant hydroxyl groups.  

Science.gov (United States)

Novel amphiphilic block copolymers bearing pendant hydroxyl groups polylactide-b-poly(3,3-bis(Hydroxymethyl-triazolylmethyl) oxetane)-b-polylactide (PLA-b-PHMTYO-b-PLA) were synthesized via a facile and efficient method. First, the block copolymer intermediates polylactide-b-poly(3,3-Diazidomethyloxetane)-b-polylactide (PLA-b-PBAMO-b-PLA) were synthesized through ring-opening polymerization of lactide using PBAMO as a macroinitiator. Following "Click" reaction of PLA-b-PBAMO-b-PLA with propargyl alcohol provided the targeted amphiphilic block copolymers PLA-b-PHMTYO-b-PLA with pendant hydroxyl groups. The composition and structure of prepared copolymers were characterized by (1)H nuclear magnetic resonance ((1)H NMR) spectroscopy, Fourier transform infrared (FT-IR) and gel permeation chromatography (GPC). The self-assembly behavior of the copolymers in water was investigated by transmission electron microscope (TEM), dynamic light scattering (DLS) and static light scattering (SLS). The results showed that the novel copolymers PLA-b-PHMTYO-b-PLA self-assembled into spherical micelles with diameters ranging from 100 nm to 200 nm in aqueous solution. These copolymers also exhibited low critical micellar concentrations (CMC: 6.9 × 10(-4)mg/mL and 3.9 × 10(-5)mg/mL, respectively). In addition, the in vitro cytotoxicity of these copolymers was determined in the presence of L929 cells. The results showed that the block copolymers PLA-b-PHMTYO-b-PLA exhibited better biocompatibility. Therefore, these well-defined copolymers are expected to find some applications in drug delivery or tissue engineering. PMID:25175206

Hu, Gaicen; Fan, Xiaoshan; Xu, Bingcan; Zhang, Delong; Hu, Zhiguo

2014-10-01

48

Metallographic analysis of 3000-year-old Kanalski Vrh hoard pendant  

International Nuclear Information System (INIS)

In a Late Bronze Age hoard at Kanalski Vrh in Slovenia, bronze pendants were found among numerous other artifacts. Among them a group of nine pendants of very similar compositions contained higher amounts of antimony, arsenic, nickel, cobalt, and iron, which suggested that speiss was added to bronze. Furthermore, most pendants had a silvery grey surface that differed from the common color of tin bronze, with about 13% Sn. One of the pendants was analysed by light optical and electron microscopy, Auger electron spectroscopy (AES), X-ray diffraction (XRD), and differential thermal analysis (DTA). Analyses revealed that the surface of the pendant was corroded, the copper alpha phase was eaten away, and the remaining eutectoid phase exhibited that silvery grey color. Comparison of chemical composition of the pendant and of compositions of speiss ingots found in the same hoard indicated that speisses could be used as alloying additions in making melts for casting pendants

49

Photoconductive properties of polysilane copolymers with pendant siloxane groups  

Science.gov (United States)

The oxygen durability of poly(methylphenylsilane) (PMPS) in photoconduction has been improved by the use of copolysilanes with disiloxane-pendant groups. X-ray photoelectron spectroscopy analysis shows that disiloxane groups of the copolysilanes accumulate on their top-most surface at a much higher concentration than the bulk disiloxane concentration. The preferential coverage of disiloxane groups on the surface evidently leads to formation of a highly oxygen durable surface. The hole drift mobility of the charge carriers in copolysilanes with 5 mol % of disiloxane-pendant groups is over 10-4 cm2 V-1 s-1 at E>105V cm-1, almost comparable to that of PMPS. It was noted that the practical Xerographic potential decay was stabilized by the copolysilanes, while PMPS deteriorated after oxygen exposure.

Matsukawa, Kimihiro; Tamai, Toshiyuki; Inoue, Hiroshi

2000-07-01

50

Polyimide characterization studies - Effect of pendant alkyl groups  

Science.gov (United States)

The effect on selected polyimide properties when pendant alkyl groups were attached to the polymer backbone was investigated. A series of polymers were prepared using benzophenone tetracarboxylic acid dianhydride (BTDA) and seven different p-alkyl-m,p'-diaminobenzophenone monomers. The alkyl groups varied in length from C(1) (methyl) to C(9) (nonyl). The polyimide prepared from BTDA and m,p'-diaminobenzophenone was included as a control. All polymers were characterized by various chromatographic, spectroscopic, thermal, and mechanical techniques. Increasing the length of the pendant alkyl group resulted in a systematic decrease in glass transition temperature (Tg) for vacuum cured films. A 70 C decrease in Tg to 193 C was observed for the nonyl polymer compared to the Tg for the control. A corresponding systematic increase in Tg indicative of crosslinking, was observed for air cured films. Thermogravimetric analysis revealed a slight sacrifice in thermal stability with increasing alkyl length. No improvement in film toughness was observed.

Jensen, B. J.; Young, P. R.

1984-01-01

51

Maximum Stable Sets and Pendant Vertices in Trees  

CERN Document Server

One theorem of Nemhauser and Trotter ensures that, under certain conditions, a stable set of a graph G can be enlarged to a maximum stable set of this graph. For example, any stable set consisting of only simplicial vertices is contained in a maximum stable set of G. In this paper we demonstrate that an inverse assertion is true for trees of order greater than one, where, in fact, all the simplicial vertices are pendant. Namely, we show that any maximum stable set of such a tree contains at least one pendant vertex. Moreover, we prove that if T does not own a perfect matching, then a stable set, consisting of at least two pendant vertices, is included in the intersection of all its maximum stable sets. For trees, the above assertion is also a strengthening of one result of Hammer, Hansen, and Simeone, stating that if half of order of G is less than the cardinality of a maximum stable set of G, then the intersection of all its maximum stable sets is non-empty.

Levit, V E; Levit, Vadim E.; Mandrescu, Eugen

1999-01-01

52

Designed pendant chain covalently bonded to silica gel for cation removal  

International Nuclear Information System (INIS)

The precursor 1,4-bis(3-aminopropyl)piperazine organofunctionalized silica gel reacted with methylacrylate to yield a new inorganic-organic chelating material, by adopting a heterogeneous and divergent synthetic approach. The synthesized materials were characterized through elemental analyses and spectroscopic techniques such as infrared, nuclear magnetic nuclei of carbon-13 and silicon-29. Due to the increment of basic centers attached to the pendant chains the metal adsorption capability of the final chelating material, was found to be higher than its precursor. The adsorption of metal ions from aqueous solution followed the order Cu2+ > Ni2+ > Co2+. Both Langmuir and Freundlich models were found to be applicable for the adsorption of copper, with the equilibrium parameter value within zero to one. The competitive sorption behavior, with variation of pH, was favorable for the separation of copper from binary mixtures with nickel and cobalt. When sodium, potassium and magnesium cations are present in the medium little effects on adsorption were observed, thus suggesting that the synthesized material can be useful for removal of toxic/heavy metal ions from natural and wastewater systems

53

ADSORPTION OF CELLOBIOSE-PENDANT POLYMERS TO A CELLULOSE MATRIX DETERMINED BY QUARTZ CRYSTAL MICROBALANCE ANALYSIS  

Directory of Open Access Journals (Sweden)

Full Text Available Cellobiose-pendant polymers were synthesized by radical polymerization and their affinity for a cellulose matrix was investigated by quartz crystal microbalance (QCM. A 2-(methacryloyloxyethylureido cellobiose (MOU-Cel macromer was synthesized by coupling cellobiosylamine with 2-(methacryloyloxyethyl isocyanate followed by polymerization in an aqueous radical reaction system. The interaction of the resulting poly(MOU-Cel with a pure cellulose matrix in water was evaluated by QCM analysis. Poly(MOU-Cel was strongly adsorbed to the cellulose substrate, whereas neither cellobiose nor MOU-Cel macromer exhibited an attractive interaction with cellulose. This specific interaction was not inhibited by the presence of ionic contaminants, suggesting that multiple cellobiopyranose moieties in each polymer molecule might cooperatively enhance its affinity for cellulose. Moderate insertion of acrylamide units into the polymer backbone improved the affinity for cellulose, possibly due to an increased mobility of sugar side chains. Polymers such as these, with a high affinity for cellulose, have potential applications for the surface functionalization of cellulose-based materials, including paper products.

Shingo Yokota

2009-08-01

54

Waveform synthesizer  

International Nuclear Information System (INIS)

A method of producing optical and electrical pulses of desired shape. An optical pulse of arbitrary but defined shape illuminates one end of an array of optical fiber waveguides of differing lengths to time differentiate the input pulse. The optical outputs at the other end of the array are combined to form a synthesized pulse of desired shape

55

Waveform synthesizer  

Science.gov (United States)

A method of producing optical and electrical pulses of desired shape. An optical pulse of arbitrary but defined shape illuminates one end of an array of optical fiber waveguides of differing lengths to time differentiate the input pulse. The optical outputs at the other end of the array are combined to form a synthesized pulse of desired shape.

Franks, Larry A. (Santa Barbara, CA); Nelson, Melvin A. (Santa Barbara, CA)

1981-01-01

56

Incorporation of Cyclotriphosphazene as Pendant Groups to the Sago Network  

International Nuclear Information System (INIS)

Cyclotriphosphazene-incorporated sago wastes as pendant groups have been prepared and structurally characterized using FT-IR and SEM. The chemically modified sago wastes composite was applied with binders and developed as sound absorbing panels. These panels are a class of organic-inorganic based materials that exhibit excellent fire retardant properties. Sound absorbance test has given a higher value at 250, 500 and 2000 Hz, which indicates the suitability of the panel for used in medium frequency. The panel was 51 % lighter compared to fiber board. The function and basic manufacturing of sound absorbers products was aligned with the present products in the market. (author)

57

Jérusalem et la Palestine pendant la première guerre mondiale  

Directory of Open Access Journals (Sweden)

Full Text Available La journée d’études « Jérusalem et la Palestine pendant la première guerre mondiale » s’inscrit dans le cadre du programme « La France, l’Europe occidentale et la Palestine, 1799-1948 » du Centre de recherche français de Jérusalem. À la suite du colloque portant sur un long XIXe siècle, de 1799 à 1917 (9-11 novembre 1998, et avant la rencontre des 29-30 novembre-1er décembre 1999, portant sur la période mandataire (1917-1948, il paraissait indispensable de s’attarder sur le premier conflit ...

Dominique Trimbur

2008-05-01

58

A new formation process for calcic pendants from Pahranagat Valley, Nevada, USA, and implication for dating Quaternary landforms  

Science.gov (United States)

It has been assumed that soil pendants form in a similar manner as stalactites, in which innermost laminae are the oldest and outer laminae are the youngest. This study presents a new interpretation for soil pendant development. Pahranagat Valley, Nevada, pendants contain features indicating continued precipitation through time at the clast-pendant contact, implying that the oldest deposits are not always found at the pendant-clast contact, as other studies have assumed. These features include a void at the clast-pendant contact where minerals such as calcium carbonate, silica, and/or fibrous silicate clays precipitate. In addition, fragments of the parent clast and detrital grains are incorporated into the pendant and are displaced and/or dissolved and result in the formation of sepiolite. This study indicates that pendants are complex, open systems that during and after their formation undergo chemical changes that complicate their usefulness for dating and paleoenvironmental analyses.

Brock, Amy L.; Buck, Brenda J.

2005-05-01

59

A Quasi-Containerless Pendant Drop Method for Surface Tension Measurements of Molten Metals and Alloys  

Science.gov (United States)

A quasi-containerless pendant drop method for measuring the surface tension of molten metals and alloys is being developed. The technique involves melting the end of a high-purity metal rod by bombardment with an electron beam to form a pendant drop under ultra-high vacuum conditions to minimize surface contamination.

Thiessen, David B.; Man, Kin F.

1994-01-01

60

Les caractéristiques du rythme de sécrétion de mélatonine ne sont pas modifiées pendant la gestation chez la brebis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Les caractéristiques du rythme de sécrétion de la mélatonine ont été étudiées pendant la gestation en répétant les mesures sur les mêmes animaux. Treize brebis, soumises à une photopériode naturelle, ont été utilisées et les caractéristiques du rythme de sécrétion de la mélatonine ont été mesurées pendant un cycle oestrien et pendant la gestation. La durée de sécrétion et les concentrations moyennes de mélatonine pendant l’élévation nocturne ont ?...

Zarazaga Garce?s, Luis A?ngel; Malpaux, B.; Chemineau, Phileppe

1996-01-01

 
 
 
 
61

Gravity model and structural implications of the Goddard Pendant, Sierra Nevada, California.  

Science.gov (United States)

A subsurface model for the Goddard pendant is constructed from a residual gravity high of about 7mGal over the pendant. The model, which is the simplest and most geologically reasonable possibility, shows a metamorphic block that tapers with depth and extends about 3.5km below the surface. The structures in the Goddard pendant are similar in style and orientation to those in other Sierra Nevada pendants, indicating that the country rock was neither deformed nor rotated during pluton emplacement. Consequently, emplacement must have been a passive rather than a forceful process. The pendant itself represents a piece of country rock trapped between plutons which are dome shaped in cross section. -Authors

du Bray, E.A.; Oliver, H.W.

1981-01-01

62

Radiation syntheses  

International Nuclear Information System (INIS)

Syntheses using energetic radiation are a modern method of preperative research and application. The strong development of radioactive sources in the past 25 years increased the efforts in this area. Compounds which are hard or impossible to prepare using conventional methods may frequently be prepared directly and in a pure form via a radiation synthesis pathway. Competition with conventional methods is possible in special cases on a lab bench as well as on an industrial scale. This present report is concerned with the radioation synthesis of low molecular compounds. The endproducts prepared using high energy radiation are not radioactive, they are thus generally easy to handle. (orig.)

63

Synthesis and Characterization of Novel Soluble Aromatic Polyesters with Pendant Cyano Groups  

Directory of Open Access Journals (Sweden)

Full Text Available 2, 6-Bis (4-carboxyphenoxy benzonitrile was first synthesized by condensation of 2, 6-difluorobenzonitrile with p-Hydroxybenzoic acid in the presence of KOH and DMSO. And then the reaction of 2, 6-bis (4-carboxyphenoxy benzonitrile with sulfur oxychloride yieded 2, 6-bis (4-chloroformylphenoxy benzonitrile (BClPOBN. A series of novel soluble aromatic polyesters with pendant cyano groups were prepared by polycondensation of different aromatic diphenols and 2,6-bis (4-chloroformylphenoxy benzonitrile (BClPOBN using 1,2-dichoroethane (DCE as solvent and pyridine as the absorbent of HCl. The resulting polymers were characterized by different physico-chemical techniques, such as FT-IR, Thermogravimetric analysis (TGA, Wide angle X-ray diffraction (WAXD, and so on. All the polymers had the proposed structure and were amorphous. Thermogravimetric studies showed that the thermal decomposition temperatures (Tds at 5% weight loss of polymers were 391~406 ? in N2 atmosphere, indicating they had good thermal stabilities. The prepared polyesters exhibited good solubility in some common solvents, such as CHCl3, ethylene dichloride (DCE, CH2Cl2, tetrahydrofuran (THF as well as aprotic polar organic solvents such as N-methyl pyrrolidone (NMP, N, N-dimethylacetamide (DMAC and N, N-dimethylformamide (DMF, and so on.

Yikai Yu

2009-03-01

64

Synthesizing Chaos  

Science.gov (United States)

Chaos is usually attributed only to nonlinear systems. Yet it was recently shown that chaotic waveforms can be synthesized by linear superposition of randomly polarized basis functions. The basis function contains a growing oscillation that terminates in a large pulse. We show that this function is easily realized when viewed backward in time as a pulse followed by ringing decay. Consequently, a linear filter driven by random pulses outputs a waveform that, when viewed backward in time, exhibits essential qualities of chaos, i.e. determinism and a positive Lyapunov exponent. This phenomenon suggests that chaos may be connected to physical theories whose framework is not that of a deterministic dynamical system. We demonstrate that synthesizing chaos requires a balance between the topological entropy of the random source and the dissipation in the filter. Surprisingly, using different encodings of the random source, the same filter can produce both Lorenz-like and R"ossler-like waveforms. The different encodings can be viewed as grammar restrictions on a more general encoding that produces a chaotic superset encompassing the Lorenz and R"ossler paradigms of nonlinear dynamics. Thus, the language of deterministic chaos provides a useful description for a class of signals not generated by a deterministic system.

Blakely, Jonathan; Corron, Ned; Hayes, Scott; Pethel, Shawn

2007-03-01

65

Multicolor electrochromic performance of electroactive poly(amic acid) containing pendant oligoaniline, azobenzene and sulfonic acid groups  

International Nuclear Information System (INIS)

A novel electroactive poly(amic acid) (EDA-CON-EPAA) containing oligoaniline pendants, azobenzene and sulfonic acid groups was synthesized by copolymerization. The synergistic interplay of these three distinct functional groups results in a number of interesting and novel properties. The polymer showed photoisomerization induce by irradiation with ultraviolet light and visible light by virtue of azobenzene groups, and also revealed excellent electroactivity in acid, neutral and even in alkaline solutions (pH = 12) due to self-doping between oligoaniline and sulfonic acid (and/or carboxylic acid) groups. Moreover, EDA-CON-EPAA displayed acceptable electrochromic performance even in alkaline solutions and multiple colors attributed to the complementary effects of the two chromophores, which greatly enlarged the range of the electrochromic application. The coloration efficiency could still reach 93.8 cm2/C (at 700 nm) even at pH = 10

66

On the Odd Gracefulness of Cyclic Snakes With Pendant Edges  

Directory of Open Access Journals (Sweden)

Full Text Available Graceful and odd gracefulness of a graph are two entirely different concepts. A graph may posses one orboth of these or neither. We present four new families of odd graceful graphs. In particular we show an oddgraceful labeling of the linear kC4 ? snake e mK1 and therefore we introduce the odd graceful labeling of4 1 kC ? snake e mK ( for the general case . We prove that the subdivision of linear 3 kC ? snake is oddgraceful. We also prove that the subdivision of linear 3 kC ? snake with m-pendant edges is odd graceful.Finally, we present an odd graceful labeling of the crown graph n 1 P e mK .

E. M. Badr

2013-01-01

67

Robotic Arm  

Science.gov (United States)

A robotic arm that can be worn at home may someday help stroke victims regain lost mobility. It's being developed by Arizona State University bioengineer Jiping He and his colleagues, with support from the National Institutes of Health. The sleeve-like device features four pneumatic muscles, from the shoulder to the wrist, that help the real arm move. As the patient gets stronger over time, the robotic muscles gradually back off.The device is still in the prototype stage, but if it proves successful, it could be a lot cheaper than long-term, one-on-one physical therapy.This resource also includes a text description of the research and links for further inquiry.

American Association for the Advancement of Science (;)

2005-06-27

68

Layered inorganic/organic mercaptopropyl pendant chain hybrid for chelating heavy cations  

International Nuclear Information System (INIS)

Graphical abstract: Crystalline lamellar silicate RUB-18 was immobilized with mercaptopropyl groups at the surface and then used as support for cadmium and lead removal from aqueous solutions. Highlights: ? Synthetic methodology requires intercalation. ? Organofunctionalized ilerite compound as sorbent. ? Active mercaptopropyl groups remove cations. ? High maximum sorption capacity for cadmium. -- Abstract: Heavy metal sorbents with uptake capacities for divalent cadmium and lead cation removal from aqueous solutions have been synthesized by grafting mercaptopropyltrimethoxysilane onto the surface of two different precursors obtained from lamellar ilerite, its acidic and the cetyltrimethylammonium exchanged forms. The organofunctionalization was carried out by two different procedures: reflux and solvent evaporation methodologies. Elemental analysis data based on carbon content gave 1.37 and 3.53 mmol of organic pendant groups per gram of hybrid by the reflux method, when starting from acidic ilerite and the surfactant form. X-ray diffraction corroborated the maintenance of the original crystallinity. Infrared spectroscopy and nuclear magnetic resonance for 29Si and 13C nuclei are in agreement with the success of the proposed method. The sulfur basic centers attached to the lamellar structure are used to coordinate both cations at the solid/liquid interface. The isotherms were obtained through the batchwise process and the experimental data were adjusted to the Freundlich model. The maximum sorption capacities of 5.55 and 5.12 mmol g?1 for lead and 6.10 and 7.10 mmol g?1 for cadmium were obtained for organofunctionalized ilerite and its surfactant form, synthesized by reflux methodology. This behavior suggested that these hybrids could be employed as promising sorbents with a polluted system.

69

Poly(phenylacetylene)s bearing a peptide pendant: helical conformational changes of the polymer backbone stimulated by the pendant conformational change.  

Science.gov (United States)

Optically active, cis-transoid poly(phenylacetylene) derivatives bearing a poly(gamma-benzyl-L-glutamate) [poly(PBGAm)] or poly(L-glutamic acid) [poly(PGAm)] chain as the pendant were prepared by polymerisation of the corresponding macromonomer with a rhodium catalyst followed by hydrolysis of the pendant ester groups. Their conformational changes in solution, induced by a helix-coil transition of the pendant polypeptides, were investigated using circular dichroism (CD) and absorption spectroscopies. A series of macromonomers with a different peptide chain lengths was synthesised by the polymerisation of the N-carboxyanhydride of gamma-benzyl-L-glutamate with a phenylacetylene bearing an alanine residue as the initiator. The obtained macromonomers (PBGAm) were further polymerised with a rhodium catalyst in N,N-dimethylformamide (DMF) to yield novel poly(phenylacetylene)s [poly(PBGAm)] with a poly(gamma-benzyl-L-glutamate) pendant. The poly(PBGAm) exhibited an induced circular dichroism (ICD) in the UV/Vis region of the polymer backbone in dimethyl sulfoxide (DMSO), probably due to the prevailing one-handed helix formation. The Cotton effect signs of a DMSO solution of the poly(PBGAm) were inverted and accompanied by a visible colour change in the presence of an increasing amount of chloroform or DMF containing lithium chloride. The results suggest that poly(PBGAm) may undergo a conformational change such as a helix-helix transition with a different helical pitch responding to a change in the alpha-helix content of the poly(gamma-benzyl-L-glutamate) pendant. Moreover, a water-soluble poly(PGAm) also showed a similar, but dramatic change in its helical conformation with a visible colour change stimulated by a helix-coil transition of the pendant poly(L-glutamic acid) chains by changing the pH in water. PMID:15317054

Maeda, Katsuhiro; Kamiya, Nobuto; Yashima, Eiji

2004-08-20

70

Removal and recovery of toxic metal ions from aqueous waste sites using polymer pendant ligands  

International Nuclear Information System (INIS)

The purpose of this project is to investigate the use of polymer pendant ligand technology to remove and recover toxic metal ions from DOE aqueous waste sites. Polymer pendant lgiands are organic ligands, anchored to crosslinked, modified divinylbenzene-polystyrene beads, that can selectively complex metal ions. The metal ion removal step usually occurs through a complexation or ion exchange phenomena, thus recovery of the metal ions and reuse of the beads is readily accomplished

71

Environmental responsive polymers based on pendant ?-amino acid groups  

International Nuclear Information System (INIS)

Loosely cross-linked poly(acryloyl-L-proline methyl ester, A-ProOMe) gels exhibit a lower critical solution temperature (LCST) of approximately 14degC, as resulting in appearance of such a thermo-responsive function as swelling below the LCST temperature and deswelling above the LCST temperature. This gel forms the rigid membrane barrier at the surface immediately after immersion in water at temperatures more than 14degC. Such a barrier markedly blocks the diffusion of water from the interior side of the gel, suggesting that this feature is applicable to drug delivery systems as external stimulus-responsive biomaterials. On the other hand, films which were obtained by polymerizing diethyleneglycol-bis-allylcarbonate (CR-39) monomer form a homogeneous pore when etched chemically after heavy ion irradiation. We will also apply the pendant amino acid-containing polymers for the on-off control of ion track pores in the film responding to environmental changes. (author)

72

A new DRAM-type memory devices based on polymethacrylate containing pendant 2-methylbenzothiazole  

International Nuclear Information System (INIS)

Graphical abstract: The devices fabricated with 75 nm and 45 nm thick pBVMA films were both found to exhibit DRAM type memory behaviors, which may indicate that the Al nanoparticles had no penetration into the thin film during the vacuum-deposition process. Highlights: ? The side-functional moieties of pBVMA regularly arranged in film state. ? The device exhibits volatile memory behavior with an ON/OFF current ratio up to 105. ? The film thickness has nothing to do with the device's memory behavior. ? Physical theoretical models and molecular simulation supported the memory mechanism. - Abstract: A polymethacrylate containing pendant 2-methylbenzothiazole (pBVMA) with good thermal stability was synthesized by free radical polymerization. The devices based on pBVMA possess a sandwich structure comprising bottom indium-tin oxide (ITO) electrode and top Al electrode. The as-fabricated device exhibits the dynamic random access memory (DRAM) behavior with an ON/OFF current ratio up to 105 and can endure 108 read cycles under ?1 V pulse voltage. The effect of the film thickness on the device performance was investigated and the devices fabricated with 75 nm and 45 nm thick pBVMA films were both found to exhibit DRAM type memory behaviors, which may indicate that the Al nanoparticles had no penetration into the thin film during the vacuum-deposition process. The molecular simulation and physical theoretical models were analyzed and etical models were analyzed and the mechanism of the DRAM performance may be attributed to the weak electron withdrawing ability of the molecule.

73

The syntheses and electrochemical studies of a ferrocene substituted diiminopyridine ligand and its P, S, Se, and Te complexes.  

Science.gov (United States)

A new reversible, redox active diiminopyridine ligand (1Fc) containing pendant ferrocene functionalities was isolated and fully characterized. The reaction of 1Fc with chalcogen pseudohalides of sulfur, selenium, and tellurium yielded the respective N,N',N?-chelated chalcogen dications. Phosphorus chemistry proceeded in a related manner but, in this case, by the direct addition of 1Fc with PI(3) to yield the N,N',N?-chelated P(I) cation. These species represent the first synthesized main group complexes involving a redox active diiminopyridine ligand containing pendant ferrocenes. Electrochemical studies of the free ligand shows a reversible two-electron process. The chelated phosphorus cation, however, displayed three events, the first being a quasi-reversible two-electron process, involving the oxidation at the P(I) center, resulting in a P(III) cation. The subsequent reversible one- and two-electron processes arise from the ligand framework and pendant ferrocenes, respectively. PMID:22775510

Magdzinski, Eleanor; Gobbo, Pierangelo; Martin, Caleb D; Workentin, Mark S; Ragogna, Paul J

2012-08-01

74

Concentration effects on peptide elution from pendant PEO layers.  

Science.gov (United States)

In earlier work, we have provided direction for development of responsive drug delivery systems based on modulation of structure and amphiphilicity of bioactive peptides entrapped within pendant polyethylene oxide (PEO) brush layers. Amphiphilicity promotes retention of the peptides within the hydrophobic inner region of the PEO brush layer. In this work, we describe the effects of peptide surface density on the conformational changes caused by peptide-peptide interactions, and show that this phenomenon substantially affects the rate and extent of peptide elution from PEO brush layers. Three cationic peptides were used in this study: the arginine-rich amphiphilic peptide WLBU2, the chemically identical but scrambled peptide S-WLBU2, and the non-amphiphilic homopolymer poly-l-arginine (PLR). Circular dichroism (CD) was used to evaluate surface density effects on the structure of these peptides at uncoated (hydrophobic) and PEO-coated silica nanoparticles. UV spectroscopy and a quartz crystal microbalance with dissipation monitoring (QCM-D) were used to quantify changes in the extent of peptide elution caused by those conformational changes. For amphiphilic peptides at sufficiently high surface density, peptide-peptide interactions result in conformational changes which compromise their resistance to elution. In contrast, elution of a non-amphiphilic peptide is substantially independent of its surface density, presumably due to the absence of peptide-peptide interactions. The results presented here provide a strategy to control the rate and extent of release of bioactive peptides from PEO layers, based on modulation of their amphiphilicity and surface density. PMID:24780434

Wu, Xiangming; Ryder, Matthew P; McGuire, Joseph; Schilke, Karl F

2014-06-01

75

Accurate surface tension measurement of glass melts by the pendant drop method  

Science.gov (United States)

A pendant drop tensiometer, coupled with image digitization technology and a best-fitting algorithm, was built to accurately measure the surface tension of glass melts at high temperatures. More than one thousand edge-coordinate points were obtained for a pendant glass drop. These edge points were fitted with the theoretical drop profiles derived from the Young-Laplace equation to determine the surface tension of glass melt. The uncertainty of the surface tension measurements was investigated. The measurement uncertainty (?) could be related to a newly defined factor of drop profile completeness (Fc): the larger the Fc is, the smaller ? is. Experimental data showed that the uncertainty of the surface tension measurement when using this pendant drop tensiometer could be ±3 mN/m for glass melts.

Chang, Yao-Yuan; Wu, Ming-Ya; Hung, Yi-Lin; Lin, Shi-Yow

2011-05-01

76

Pendant unit effect on electron tunneling in U-shaped molecules  

International Nuclear Information System (INIS)

The electron transfer reactions of three U-shaped donor-bridge-acceptor molecules with different pendant groups have been studied in different solvents as a function of temperature. Analysis of the electron transfer kinetics in nonpolar and weakly polar solvents provides experimental reaction Gibbs energies that are used to parameterize a molecular solvation model. This solvation model is then used to predict energetic parameters in the electron transfer rate constant expression and allow the electronic coupling between the electron donor and electron acceptor groups to be determined from the rate data. The U-shaped molecules differ by alkylation of the aromatic pendant group, which lies in the 'line-of-sight' between the donor and acceptor groups. The findings show that the electronic coupling through the pendant group is similar for these molecules

77

Controlled Synthesis of Fluorinated Copolymers with Pendant Sulfonates  

DEFF Research Database (Denmark)

Novel fluorinated copolymers of different architectures and bearing sulfopropyl groups were synthesized by atom transfer radical polymerization (ATRP) of aromatic fluorinated monomers and two modification reactions performed on the polymer chain - demethylation followed by sulfopropylation. As a result two types of fluorinated copolymers were obtained. The first one was synthesized by ATRP of2,3,5,6-tetraflouro4- methoxystyrene (TFMS). Copolymers with different amounts of randomly distributed along the backbone sulfopropyl groups were obtained after the chemical modifications mentioned above. The second type copolymers have diblock architecture with one.of the blocks being sulfopropyl~ed. They were synthesized via ATRP of 2,3,4,5,6pentafluorostyrene (FS) initiated by PTFMS-macroinitiator followed by demethylation and sulfopropylation performed on the TFMS-block (Scheme 1). The) copolymers were characterized by size-exclusion chromatography, FTIR and IH NMR spectroscopy. Their thermal properties were investigated by differential scanning calorimetry and thermal gravimetric analyses.

Dimitrov, Ivaylo; Jankova Atanasova, Katja

2008-01-01

78

Dynamique folliculaire et niveaux plasmatiques de la progestérone chez la brebis Sarde pendant l’anoestrus saisonnier  

Digital Repository Infrastructure Vision for European Research (DRIVER)

L’activité ovarienne pendant le cycle oestrien de la brebis a été décrite et jusqu’à trois ondes de croissance folliculaires ont été observées (Bister et al., 1999 ; Evans et al., 2000). Ce travail contribue à une meilleure connaissance de la dynamique folliculaire et de ses relations avec les niveaux de progestérone plasmatique pendant l’anœstrus saisonnier des ovins.

Branca, Andrea; Marongiu, Maria Laura; Gallus, Marilia; Floris, Basilio Remo; Diverio, Silvana; Humblot, Patrice

2003-01-01

79

Synthesis of hydronaphthalenes through coupling of enyne carbonyl compounds that contain pendant alkene groups with Fischer carbene complexes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The coupling of enyne carbonyl compounds that contain pendant alkene groups with Fischer carbene complexes to afford furans that contain pendant alkene groups is described. Subsequent intramolecular Diels-Alder reactions are effective in select cases, resulting in hydronaphthalene systems after dehydration. Although the Diels-Alder event is thermodynamically unfavorable, the overall transformation of alkene-furans to dihydronaphthalenes is a favorable process.

Kumar-patti, Rajesh; Duan, Shaofeng; Camacho-davila, Alejandro; Waynant, Kris; Dunn, Kenneth A.; Herndon, James W.

2010-01-01

80

Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups  

Digital Repository Infrastructure Vision for European Research (DRIVER)

(±)-10-Methacryloyloxycamphorquinone (MCQ) was synthesized from (±)-10-camphorsulfonic acid either by a known seven-step synthetic route or by a novel, shorter five-step synthetic route. MCQ was copolymerized with styrene (S) and the photochemical behavior of the copolymer MCQ/S was compared with that of a formerly studied copolymer of styrene with monomers containing the benzil (BZ) moiety (another 1,2-dicarbonyl). Irradiation (? > 380 nm) of...

Branislav Husár; Norbert Moszner; Ivan Luká?

2012-01-01

 
 
 
 
81

Block and random copolymers bearing cholic acid and oligo(ethylene glycol) pendant groups: aggregation, thermosensitivity, and drug loading.  

Science.gov (United States)

A series of block and random copolymers consisting of oligo(ethylene glycol) and cholic acid pendant groups were synthesized via ring-opening metathesis polymerization of their norbornene derivatives. These block and random copolymers were designed to have similar molecular weights and comonomer ratios; both types of copolymers showed thermosensitivity in aqueous solutions with similar cloud points. The copolymers self-assembled into micelles in water as shown by dynamic light scattering and transmission electron microscopy. The hydrodynamic diameter of the micelles formed by the block copolymer is much larger and exhibited a broad and gradual shrinkage from 20 to 54 °C below its cloud point, while the micelles formed by the random copolymers are smaller in size but exhibited some swelling in the same temperature range. Based on in vitro drug release studies, 78% and 24% paclitaxel (PTX) were released in 24 h from micelles self-assembled by the block and random copolymers, respectively. PTX-loaded micelles formed by the block and random copolymers exhibited apparent antitumor efficacy toward the ovarian cancer cells with a particularly low half-maximal inhibitory concentration (IC50) of 27.4 and 40.2 ng/mL, respectively. Cholic acid-based micelles show promise as a versatile and potent platform for cancer chemotherapy. PMID:24725005

Shao, Yu; Jia, Yong-Guang; Shi, Changying; Luo, Juntao; Zhu, X X

2014-05-12

82

Photoinduced intrapolymer electron transfer in the pendant [60]fullerene-aminopolymer  

Science.gov (United States)

A strong dependence of observed fluorescence quantum yields of fullerene chromophores in the pendant [60]fullerene-poly(ethyleneimine) on solvent polarity is reported. The solvent polarity effects of the fluorescence properties of the polymer-bound [60]fullerene cages are likely due to intrapolymer electron transfer quenching by the secondary amine units in the polymer structure.

Sun, Ya-Ping; Bunker, Christopher E.; Liu, Bing

1997-06-01

83

Quenching of excited state of polymer-pendant Ru(bpy)32+ by methylviologen  

International Nuclear Information System (INIS)

Copolymer pendant tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)32+) complexes were prepared, and the quenchings of their excited state with methylviologen (MV2+) were studied. The quenching rate constant of the excited state of copolymer pendant Ru(bpy)32+ containing acrylic acid showed a novel pH effect in water which depends on the dissociation of the acrylic acid to acrylate. The dissociated acrylic acid forms an anionic microdomain around the pendant Ru complex, and attracts the positively charged MV2+, thus enhancing the apparent rate of the quenching by 10 to 30 times. The copolymer pendant Ru complex containing acrylic acid showed quenching behavior in methyl alcohol entirely different from that in aqueous system depending on the additives such as acid, alkaline, or neutral salt. The non-linear Stern-Volmer plots indicate the presence of static quenching in methyl alcohol. Quenching models consisting of both dynamic and static mechanisms are proposed and discussed. (author)

84

The Learning of "Pendant" and "Depuis" by English Speakers: A Contrastive Analysis.  

Science.gov (United States)

Due to differences in the grammars of English and French, "pendant" and "depuis" are as difficult to master for English speakers as their equivalents "for" and "since" are for French speakers. To the former, three facts are crucial: (1) "depuis" corresponds to both "for" and "since," which creates ambiguities; (2) "depuis" applies to an…

Laroche, Jacques M.

85

Magnetic properties and thermodynamics of decorated Ising chain with pendants of arbitrary spin  

International Nuclear Information System (INIS)

The decorated Ising chain with pendants of arbitrary spin and the single-ion anisotropy is exactly solved by the transfer matrix method. The solutions reveal abundant novel properties than the conventional one-dimensional Ising model. It is compared with the experimental data of a necklace-like molecule-based magnet, that gives a qualitative consistency.

86

Algebraic connectivity of connected graphs with fixed number of pendant vertices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we consider the following problem: Over the class of all simple connected graphs of order $n$ with $k$ pendant vertices ($n,k$ being fixed), which graph maximizes (respectively, minimizes) the algebraic connectivity? We also discuss the algebraic connectivity of unicyclic graphs.

Lal, Arbind K.; Patra, Kamal L.; Sahoo, Binod K.

2010-01-01

87

Self-rectifying electron beam melter for pendant-drop containerless processing  

Science.gov (United States)

A self-rectifying electron beam melting technique is described. Utilizing an ac power supply, in contrast to the more usual dc supply, the in situ self-rectifying approach offers a simple and very inexpensive means of producing metallic pendant drops for use in containerless melt-processing experiments.

Pyun, D. S.; Collings, E. W.

1993-01-01

88

Le discours sur «l'étranger» pendant la Terreur, 5 nivôse - 9 thermidor an II  

Directory of Open Access Journals (Sweden)

Full Text Available La cartographie des occurrences discursives émises par les différents producteurs d’opinion publique pendant la Révolution française permet de saisir les formes et les déterminations du discours tenu sur l’étranger du 5 nivôse au 9 thermidor an II. On constate alors que ce discours peut obéir soit à des logiques de voisinage guerrier soit à des logiques politiques.

Sophie WAHNICH

1995-06-01

89

Arm Injuries and Disorders  

Science.gov (United States)

... these parts of the arm can occur during sports, a fall or an accident. Types of arm injuries include Tendinitis and bursitis Sprains Dislocations Broken bones Some nerve problems, arthritis, or cancers can affect the entire arm and cause pain, spasms, swelling ...

90

Arms Control Treaties  

Science.gov (United States)

Brief summaries of all the nuclear arms control treaties: Antarctic Treaty, Hot Line Agreement, Limited Test Ban Treaty, Outer Space Treaty, Latin America Nuclear Free Zone Treaty, Nuclear Non-Proliferation Treaty, Seabed Treaty, Strategic Arms Limitation Treaty I (Interim Agreement), Anti-Ballistic Missile Treaty, Threshold Test Ban Treaty, Peaceful Nuclear Explosions Treaty, Environmental Modification Convention, Strategic Arms Limitation Treaty II Treaty, South Pacific Nuclear Free Zone Treaty, Intermediate-Range Nuclear Forces Treaty - INF, Ballistic Missile Launch Notification Agreement, Strategic Arms Reduction Treaty, Strategic Arms Reduction Treaty II, Treaty of Pelindaba, Comprehensive Test Ban Treaty, Strategic Offensive Reductions Treaty

91

Cobalt(II complexes with aromatic carboxylates and N-functionalized cyclam bearing 2-pyridylmethyl pendant arms  

Directory of Open Access Journals (Sweden)

Full Text Available Novel binuclear Co(II complexeswithN-functionalized cyclam, N,N’,N”,N’’’-tetrakis(2-pyridylmethyltetraazacyclotetradecane (tpmc and one of the aromatic monoor dicarboxylato ligands (benzoate, phthalate or isophthalate ions were prepared. They were analyzed and studied by elemental analyses (C, H, N, electrical conductivities, VIS and IR spectroscopy andmagnetic as well as cyclic voltammetric measurements. In [Co2(C6H5COO2tpmc](ClO42.3H2O, the benzoate ligands are most probably coordinated as chelates in the trans-position to each Co(II and the macrocycle adopts a chair conformation. In the complexes [Co2(Ytpmc](ClO42·zH2O, (Y = phthalate or i-phthalate dianizon, z = 2; 4, it is proposed that the isomeric dicarboxylates are bonded combined as bridges and chelates. The composition and the assumed geometries of the complexes are compared with the, earlier reported, corresponding Cu(II complexes. Cyclic voltammetry measurements showed that the compounds are electrochemically stable.

G. VUCKOVIC

2005-09-01

92

Reaction of Lanthanum(III) and Gadolinium(III) complexes coordinated by pendant-armed macrocyclic ligand with salicylaldehyde  

International Nuclear Information System (INIS)

In the reaction of Lanthanum(III) and Gadolinium(III) complexes coordinated by the ligand 1,9-bis(2-aminoethyl)-1, 4, 6, 9, 12, 14-hexaazacyclohexadecane with salicylaldehyde, only Gd3+ was led to an unexpected complex with the ligand tris{2-(salicylideneamino)ethyl}amine. The difference of the reactivity was applied to the separation of La3+ and Gd3+. (author)

93

Determination of cerium ion by polymeric membrane and coated graphite electrode based on novel pendant armed macrocycle  

International Nuclear Information System (INIS)

Plasticized membranes using 2,3,4:12,13,14-dipyridine-1,3,5,8,11,13,15,18-octaazacycloicosa-2,12-diene (L1) and 2,3,4:12,13,14-dipyridine-1,5,8,11,15,18-hexamethylacrylate- 1,3,5,8,11,13,15,18-octaazacycloicosa-2,12-diene (L2) have been prepared and explored as Ce(III) selective sensors. Effect of various plasticizers viz. dibutylphthalate (DBP), tri-n-butylphthalate (TBP), o-nitrophenyloctylether (o-NPOE), dioctylphthalate (DOP), benzylacetate (BA) and anion excluders, sodium tetraphenylborate (NaTPB) and potassium tetrakis p-(chlorophenyl) borate was studied in detail and improved performance was observed. Optimum performance was observed for the membrane sensor having a composition of L2:PVC:o-NPOE:KTpClPB in the ratio of 6:34:58:2 (w/w, mg). The performance of the membrane based on L2 was compared with polymeric membrane electrode (PME) as well as with coated graphite electrode (CGE). The electrodes exhibit Nernstian slope for Ce(III) ions with limits of detection of 8.3 x 10-8 mol L-1 for PME and 7.7 x 10-9 mol L-1 for CGE. The response time for PME and CGE was found to be 12 s and 10 s respectively. The potentiometric responses are independent of the pH of the test solution in the pH range 3.5-7.5 for PME and 2.5-8.5 for CGE. The CGE could be used for a period of 5 months. The practical utility of the CGE has been demonstrated by its usage as an indicator electrode in potentiusage as an indicator electrode in potentiometric titration of oxalate and fluoride ions with Ce(III) solution. The proposed electrode was also successfully applied to the determination of fluoride ions in mouthwash solution and oxalate ions in real samples.

94

Stratigraphy and structure of the Strawberry Mine roof pendant, central Sierra Nevada, California  

Science.gov (United States)

The Strawberry mine roof pendant, 90 km northeast of Fresno, Calif., is composed of a sequence of metasedimentary rocks of probable Early Jurassic age and a sequence of metaigneous rocks of middle Cretaceous age. The metasedimentary rocks are a former miogeosynclinal sequence of marl and limestone now metamorphosed to calc-silicate hornfels and marble. A pelecypod found in the calc-silicate hornfels has been tentatively identified as a Mesozoic bivalve, possibly Inoceramus pseudomytiloides of Early Jurassic age. These metasedimentary rocks are similar in lithology, structure, and gross age to the metasedimentary rocks of the Boyden Cave roof pendant and are assigned to the Lower Jurassic Kings sequence. The younger metaigneous rocks are metamorphosed shallow-in trusi ve rocks that range in composi tion from granodiorite to rhyolite. These rocks are similar in composition and age to the metavolcanic rocks of the surrounding Merced Peak quadrangle and nearby Ritter Range, and probably represent necks or dikes that were one source for the meta volcanic rocks. The roof pendant is intruded by several plutons, ranging in composition from dioritic to highly felsic, that constitute part of the granodiorite of Jackass Lakes, also M middle Cretaceous age. The contemporaneous suites of metaigneous, metavolcanic, and plutonic rocks in the region represent a middle Cretaceous period of calc-alkalic volcanism and plutonism in the central Sierra Nevada and are interpreted as part of an Andean-type volcanic-plutonic arc. Three deformations are documented in the roof pendant. The first deformation is reflected only in the metasedimentary rocks and consists of northeast-to east-west-trending folds. Similar structures occur in the Boyden Cave roof pendant and in the Calaveras Formation and represent a Middle Jurassic regional deformation. Evidence of the second deformation occurs in the metasedimentary and metaigneous rocks and consists of folds, faults, minor structures, and regional metamorphism along N. 25? W. trends. Crosscutting of these structures by the contemporaneous granodiorite of Jackass Lakes indicates that this deformation occurred simultaneously with volcanism and plutonism during the middle Cretaceous. The third deformation involved both the roof pendant and adjacent plutonic rocks and consists of folds, faults, schistosities, and regional metamorphism along N. 65? -900 W. trends. Crosscutting of similar structures in other middle Cretaceous plutonic rocks of the Merced Peak quadrangle by undeformed late Cretaceous plutonic rocks indicates a regional deformation of middle to late Cretaceous age. Structures of similar style, orientation, and age occur elsewhere in metavolcanic and plutonic rocks throughout the central Sierra Nevada.

Nokleberg, W.J.

1981-01-01

95

Effects of Arm Number and Arm Length on Thermal Properties of Linear and Star-shaped Poly(D,L-lactides  

Directory of Open Access Journals (Sweden)

Full Text Available Influences of arm number and arm length of poly(D,L-lactides (PDLLs on their thermal properties were investigated. The PDLLs with linear (1 arm and star (4, 6 and 16 arms shapes were synthesized via ring-opening polymerization of DLL monomer in bulk at 130°C for 24 h under nitrogen atmosphere. Stannous octoate was used as a catalyst. Initiators containing hydroxyl end groups of 1, 4, 6 and 16 were chosen as core molecules for synthesizing 1-, 4-, 6- and 16-armed PDLLs, respectively. Thermal properties of the PDLLs observed from their differential scanning calorimetric and thermogravimetric thermograms strongly depended upon their arm numbers and arm lengths. For the same DLL/initiator ratio (208/1 by mole, glass transition temperatures (Tg and temperatures of maximum decomposition rate (Td, max of the PDLLs decreased when the arm length decreased (or arm number increased. For similar PDLL arm lengths (4,500 and 4,900 g moL-1 for 6-armed star-shaped and 1-armed linear PDLLs, respectively, the Tg and Td, max of star-shaped PDLL was higher than that of the linear PDLL.

Yodthong Baimark

2010-01-01

96

Spectrum of the Laplacian on a covering graph with pendant edges I: The one-dimensional lattice and beyond  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, we examine covering graphs that are obtained from the $d$-dimensional integer lattice by adding pendant edges. In the case of $d=1$, we show that the Laplacian on the graph has a spectral gap and establish a necessary and sufficient condition under which the Laplacian has no eigenvalues. In the case of $d=2$, we show that there exists an arrangement of the pendant edges such that the Laplacian has no spectral gap.

Suzuki, Aktito

2013-01-01

97

Modelling of bionic arm  

Directory of Open Access Journals (Sweden)

Full Text Available The bionic arm is a prosthesis which will allow the amputees to control it with the help of their own brain instead of depending upon the mechanical functions of the artificial limbs which are at present available in the market. A complex design of control systems is embedded in the bionic arm which will receive and analyze the signals from the brain and convert the electrical energy to mechanical energy, making the bionic arm move.

Amartya Ganguly

2010-04-01

98

Robot Arm Tutorial  

Science.gov (United States)

This tutorial provides background information on robotic arm technology and practical instructions for building your own. The author includes free-body diagrams, schematic drawings, help with performing force calculations in the joints, directions for setting torque parameters, and detailed explanations of each component in the system. For learners with little background in physics or engineering, the Robot Arm Calculator Tool determines the lifting capability of the robot arm. This resource is appropriate for courses in introductory physics or applied physics.

2012-03-15

99

Protonation of Ferrous Dinitrogen Complexes Containing a Diphosphine Ligand with a Pendant Amine  

Energy Technology Data Exchange (ETDEWEB)

The addition of protons to pendant amine containing ferrous dinitrogen complexes, of the type [FeX(N2)(PEtNMePEt)(dmpm)]+ (X = H, Cl, or Br; PEtNMePEt = Et2PCH2N(Me)CH2PEt2 and dmpm = Me2PCH2PMe2), was found to protonate at the pendant amine as opposed to the dinitrogen ligand. This protonation increased the ?N2 of the complex by about 25 cm-1, shifting the Fe(II/I) couple 330 mV to a more positive potential. A similar shift was observed in the case of [FeX(CO)(PEtNMePEt)(dmpm)]+ (X = H, Cl, or Br). Computational analysis verified these experimental results and showed the coordination of N2 to Fe(II) centers increases the basicity of N2 (vs. free N2) by 13 and 20 pKa units for the trans halides and hydrides, respectively. Although the iron center was found to increase the basicity of the bound N2 ligand, coordinated N2 is not sufficiently basic to be protonated. In the case of ferrous dinitrogen complexes containing a basic pendant methylamine, the amine site was determined to be the most basic site by 30 pKa units compared to protonation at the N2 ligand. To increase the basicity of the N2 ligand in order to promote proton transfer from the pendant amine to the N2 ligand, chemical reduction of these ferrous dinitrogen complexes was performed and found to result in oxidative addition of the methylene C-H bond of the PEtNMePEt ligand to Fe, preventing isolation of a reduced Fe(0) N2 complex. This work was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences.

Heiden, Zachariah M.; Chen, Shentan; Mock, Michael T.; Dougherty, William G.; Kassel, W. S.; Rousseau, Roger J.; Bullock, R. Morris

2013-04-01

100

Unusual cyclic terpenoids with terminal pendant prenyl moieties: from occurrence to synthesis.  

Science.gov (United States)

Covering: 1966 up to the end of 2013The paper reviews the known examples of cyclic terpenoids produced from open chain polyenic precursors by an "unusual" biosynthetic pathway, involving selective electrophilic attack on an internal double bond followed by cyclization. The resulting compounds possess cyclic backbones with pendant terminal prenyl groups. Synthetic approaches applied for the synthesis of such specifically functionalized compounds are also discussed, as well as biological activity of reported representatives. PMID:25118808

Kulcitki, Veaceslav; Harghel, Petru; Ungur, Nicon

2014-11-01

 
 
 
 
101

Surface orientation of polystyrene based polymers: steric effects from pendant groups on the phenyl ring.  

Science.gov (United States)

Near edge X-ray absorption fine structure (NEXAFS) coupled with molecular dynamics simulations were utilized to probe the orientation at the exposed surface of the polymer film for polystyrene type polymers with various pendant functional groups off the phenyl ring. For all the polymers, the surface was oriented so that the rings are nominally normal to the film surface and pointing outward from the surface. The magnitude of this orientation was small and dependent on the size of the pendant functional group. Bulky functional groups hindered the surface orientation, leading to nearly unoriented surfaces. Depth dependent NEXAFS measurements demonstrated that the surface orientation was localized near the interface. Molecular dynamics simulations showed that the phenyl rings were not oriented strongly around a particular "average tilt angle". In contrast, simulations demonstrate that the phenyl rings exhibit a broad distribution of tilt angles, and that changes in the tilt angle distribution with pendant functionality give rise to the observed NEXAFS response. The more oriented samples exhibit a higher probability of phenyl ring orientation at angles greater than 60 degrees relative to the plane of the films surface. PMID:23078172

Lenhart, Joseph L; Fischer, Daniel A; Chantawansri, Tanya L; Andzelm, Jan W

2012-11-01

102

Computational analysis of coalescence and breakup between a capillary switch and a pendant drop  

Science.gov (United States)

Although capillary switches come in a variety of configurations, one that has been receiving much attention recently consists of a continuous volume of liquid in which two drops are joined through a liquid-filled circular orifice in a plate. Recent research has focused on the bi-stable nature of such capillary switches and their potential application as optical MEMS devices. Here, we investigate the dynamics of coalescence and break-up between a capillary switch and a pendant drop hanging from a moving rod wherein the capillary switch and the pendant drop consist of the identical incompressible, Newtonian liquid. The dynamics are analyzed both using a fast, one-dimensional (1D) algorithm and also rigorously using a fully three-dimensional but axisymmetric, i.e. two-dimensional (2D), algorithm. The effects of surface tension, inertial, viscous, and gravitational forces on the dynamics of coalescence and break-up and the subsequent steady-state shapes of the capillary switch and the pendant drop are investigated. Regions of the parameter space where the 1D algorithm is reliable are also identified.

Ramalingam, Santhosh; Basaran, Osman; Lopez, Carlos; Martinovic, Ines; Hirsa, Amir

2007-11-01

103

Use of the pendant drop method to measure interfacial tension between molten polymers  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper the pendant drop method to measure interfacial tension between molten polymers is reviewed. A typical pendant drop apparatus is presented. The algorithms used to infer interfacial tension from the geometrical profile of the pendant drop are described in details, in particular a new routine to evaluate correctly the value of the radius at the apex of the drop, necessary to the calculation of interfacial tension is presented. The method was evaluated for the possibility of measuring the interfacial tension between polyethylene and polystyrene. It is shown that the method is unsuitable for the measurement of interfacial tension between high density polyethylene and polystyrene due possibly to a too small difference of density between the two polymers. Values of interfacial tension between low density polyethylene (LDPE and polystyrene (PS as a function of the molecular weight of PS are presented. It was shown that the interfacial tension between LDPE and PS increased as a function of molecular weight of PS up to values of molecular weight of roughly 40,000 g/mol, value for which entanglements occur.

Arashiro Emerson Y.

1999-01-01

104

Inorganic syntheses, v.50  

CERN Document Server

The volumes in this continuing series provide a compilation of current techniques and ideas in inorganic synthetic chemistry. Includes inorganic polymer syntheses and preparation of important inorganic solids, syntheses used in the development of pharmacologically active inorganic compounds, small-molecule coordination complexes, and related compounds. Also contains valuable information on transition organometallic compounds including species with metal-metal cluster molecules. All syntheses presented here have been tested.

Allcock, Harry R

2009-01-01

105

Inorganic syntheses, v.40  

CERN Document Server

The volumes in this continuing series provide a compilation of current techniques and ideas in inorganic synthetic chemistry. Includes inorganic polymer syntheses and preparation of important inorganic solids, syntheses used in the development of pharmacologically active inorganic compounds, small-molecule coordination complexes, and related compounds. Also contains valuable information on transition organometallic compounds including species with metal-metal cluster molecules. All syntheses presented here have been tested.

Busch, Daryle H

2009-01-01

106

Inorganic syntheses, v.58  

CERN Document Server

The volumes in this continuing series provide a compilation of current techniques and ideas in inorganic synthetic chemistry. Includes inorganic polymer syntheses and preparation of important inorganic solids, syntheses used in the development of pharmacologically active inorganic compounds, small-molecule coordination complexes, and related compounds. Also contains valuable information on transition organometallic compounds including species with metal-metal cluster molecules. All syntheses presented here have been tested.

Grimes, Russell N

2009-01-01

107

Oligosiloxane Functionalized with Pendant (1,3-Bis(9-carbazolyl)benzene) (mCP) for Solution-Processed Organic Electronics.  

Science.gov (United States)

A new oligosiloxane derivative (ODCzMSi) functionalized with the well-known 1,3-bis(9-carbazolyl)benzene (mCP) pendant moiety, directly linked to the silicon atom of the oligosiloxane backbone, has been synthesized and characterized. Compared to mCP, the attachment of the oligosiloxane chain significantly improves the thermal and morphological stabilities with a high decomposition temperature (Td =540?°C) and glass transition temperature (Tg =142?°C). The silicon-oxygen linkage of ODCzMSi disrupts the backbone conjugation and maintains a high triplet energy level (ET =3.0?eV). A phosphorescent organic light-emitting diode (PhOLED) using iridium bis(4,6-difluorophenyl)pyridinato-N,C(2) picolinate (FIrpic) as the emitter and ODCzMSi as the host shows a relatively low turn-on voltage of 5.0?V for solution-processed PhOLEDs, maximum external quantum efficiency of 9.2?%, and maximum current efficiency of 17.7?cd?A(-1) . The overall performance of this device is competitive with the best reported solution-processed blue PhOLEDs. Memory devices using ODCzMSi as an active layer exhibit non-volatile write-once read-many-times (WORM) characteristics with high stability in retention time up to 10(4) ?s and a low switch on voltage. This switching behaviour is explained by different stable conformations of ODCzMSi with high or low conductivity states which are obtained under the action of electric field through a ?-? stacking alignment of the pendant aromatic groups. These results with both PhOLEDs and memory devices demonstrate that this oligosiloxane-mCP hybrid structure is promising and versatile for high performance solution-processed optoelectronic applications. PMID:25307853

Sun, Dianming; Yang, Zhaomin; Ren, Zhongjie; Li, Huihui; Bryce, Martin R; Ma, Dongge; Yan, Shouke

2014-12-01

108

Managing new arms races  

International Nuclear Information System (INIS)

The management of new arms races in the region of Asia-Pacific includes considerations of weapons trade and transfer in the region, with an emphasis on nuclear weapons proliferation. It deals with the problem of controlling the arms trade and the efforts to control conventional weapons and underlines the possible role and influence of Conference on Cooperation and Security in Europe (CSCE)

109

Synthesis and arm dissociation in molecular stars with a spoked wheel core and bottlebrush arms.  

Science.gov (United States)

Unique star-like polymeric architectures composed of bottlebrush arms and a molecular spoked wheel (MSW) core were prepared by atom transfer radical polymerization (ATRP). A hexahydroxy-functionalized MSW (MSW(6-OH)) was synthesized and converted into a six-fold ATRP initiator (MSW(6-Br)). Linear chain arms were grafted from MSW(6-Br) and subsequently functionalized with ATRP moieties to form six-arm macroinitiators. Grafting of side chains from the macroinitiators yielded four different star-shaped bottlebrushes with varying lengths of arms and side chains, i.e., (450-g-20)6, (450-g-40)6, (300-g-60)6, and (300-g-150)6. Gel permeation chromatography analysis and molecular imaging by atomic force microscopy confirmed the formation of well-defined macromolecules with narrow molecular weight distributions. Upon adsorption to an aqueous substrate, the bottlebrush arms underwent prompt dissociation from the MSW core, followed by scission of covalent bonds in the bottlebrush backbones. The preferential cleavage of the arms is attributed to strong steric repulsion between bottlebrushes at the MSW branching center. Star-shaped macroinitiators may undergo aggregation which can be prevented by sonication. PMID:25133316

Burdy?ska, Joanna; Li, Yuanchao; Aggarwal, Anant Vikas; Höger, Sigurd; Sheiko, Sergei S; Matyjaszewski, Krzysztof

2014-09-10

110

Synthesis, Characterization and Reactivity of Fe Complexes Containing Cyclic Diazadiphosphine Ligands: The Role of the Pendant Base in Heterolytic Cleavage of H2  

Energy Technology Data Exchange (ETDEWEB)

The iron complexes CpFe(PPh2NBn2)Cl (1-Cl), CpFe(PPh2NPh2)Cl (2-Cl), CpFe(PPh2C5)Cl (3-Cl) (where PPh2NBn2 is 1,5-dibenzyl-1,5-diaza-3,7-diphenyl-3,7-diphosphacyclooctane, PPh2NPh2 is 1,3,5,7-tetraphenyl-1,5-diaza-3,7-diphosphacyclooctane, and PPh2C5 is 1,4-diphenyl-1,4-diphosphacycloheptane) have been synthesized and characterized by NMR spectroscopy, electrochemical studies, and X-ray diffraction studies. These chloride derivatives are readily converted to the corresponding hydride complexes CpFe(PPh2NBn2)H (1-H), CpFe(PPh2NPh2)H (2-H), CpFe(PPh2C5)H (3-H)] and H2 complexes [CpFe(PPh2NBn2)(H2)]BArF4, [1-H2]BArF4, (where BArF4 is B[(3,5-(CF3)2C6H3)4]?), [CpFe(PPh2NPh2)(H2)]BArF4, [2-H2]BArF4, and [CpFe(PPh2C5)(H2)]BArF4, [3-H2]BArF4 as well as [CpFe(PPh2NBn2)(CO)]BArF4, [1-CO]BArF4. Structural studies are reported for [1-H2]BArF4, 1-H, 2-H, and [1-CO]BArF4. The conformations adopted by the chelate rings of the PPh2NBn2 ligand in the different complexes are determined by attractive or repulsive interactions between the sixth ligand of these pseudo-octahedral complexes and the pendant N atom of the ring adjacent to the sixth ligand. An example of an attractive interaction is the observation that the distance between the N atom of the pendant amine and the C atom of the coordinated CO ligand for [1-CO]BArF4 is 2.848 Å, considerably shorter than the sum of the van der Waals radii of N and C atoms. Experimental and theoretical studies of H/D exchange by the complexes [1-H2]+, [2-H2]+, and [3-H2]+ indicate that the relatively rapid exchange observed for [1-H2]+ and [2-H2]+ compared to [3-H2]+ is consistent with intramolecular heterolytic cleavage of H2 mediated by the pendant amine. These mononuclear FeII dihydrogen complexes containing pendant amines in the ligands mimic crucial features of the distal Fe site of the active site of the [FeFe] hydrogenase required for H-H bond formation and cleavage. We thank the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Biosciences and Geosciences, for support of this research. S.C. (DFT computations) and M. J. O. (NMR experiments) were supported by the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under FWP 56073. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Liu, Tianbiao L.; Chen, Shentan; O' Hagan, Molly J.; Rakowski DuBois, Mary; Bullock, R. Morris; DuBois, Daniel L.

2012-04-11

111

Remote control handling arm  

International Nuclear Information System (INIS)

This invention concerns a remote control arm, of the type comprising an articulated assembly connecting a handling component to a support. This articulated assembly is made up from standard and separate components interconnected by an articulation allowing for the transmission of an independent movement to produce a pre-determined movement of this handling component with respect to the said support. Such handling arms are fully described in French patent No. 1459250, in which, incidentally, one of the inventors mentioned is the same person as in this application. One of the most important uses of such handling arms is in the fitting of power remote handling devices for hot nuclear laboratories

112

The role of pendant amines in the breaking and forming of molecular hydrogen catalyzed by nickel complexes.  

Science.gov (United States)

We present the results of a comprehensive theoretical investigation of the role of pendant amine ligands in the oxidation of H(2) and formation of H(2) by [Ni(P(R)(2)N(R')(2))(2)](2+) electrocatalysts (P(R)(2)N(R')(2) is the 1,5-R'-3,7-R derivative of 1,5-diaza-3,7-diphosphacyclooctane, in which R and R' are aryl or alkyl groups). We focus our analysis on the thermal steps of the catalytic cycle, as they are known to be rate-determining for both H(2) oxidation and production. We find that the presence of pendant amine functional groups greatly facilitates the heterolytic H(2) bond cleavage, resulting in a protonated amine and a Ni hydride. Only one single positioned pendant amine is required to serve this function. The pendant amine can also effectively shuttle protons to the active site, making the redistribution of protons and the H(2) evolution a very facile process. An important requirement for the overall catalytic process is the positioning of at least one amine in close proximity to the metal center. Indeed, only protonation of the pendant amines on the metal center side (endo position) leads to catalytically active intermediates, whereas protonation on the opposite side of the metal center (exo position) leads to a variety of isomers, which are detrimental to catalysis. PMID:22532421

Raugei, Simone; Chen, Shentan; Ho, Ming-Hsun; Ginovska-Pangovska, Bojana; Rousseau, Roger J; Dupuis, Michel; DuBois, Daniel L; Bullock, R Morris

2012-05-21

113

Inorganic Syntheses, 35  

CERN Document Server

The Inorganic Syntheses series provides all users of inorganic substances with detailed and foolproof procedures for the preparation of important and timely compounds.: Includes complete, up-to-date procedures involving important inorganic substances; Contains subject, contributor, and formula indexes

Rauchfuss, Thomas

2010-01-01

114

Hopping synthesizer controller  

Science.gov (United States)

The EHF SATCOM (Extremely High Frequency Satellite Communications) project includes a contract in industry for a ground-based model of a frequency hopping spread spectrum satellite communications system. There is also an in-house effort in key technical areas. One requirement is a Hopping Synthesizer Controller to drive a frequency synthesizer, and is the subject of this report. The controller was built on a single board using a digital signal processor for calculations and an erasable programmable logic device for interfacing. It provides the pseudo-random hopping sequence, modulation, channel selection and Doppler precorrection. The Hopping Synthesizer Controller can drive the frequency synthesizer at hop rates up to 25 khops/s. Four configurations are supported: operation within either the payload or ground terminal simulator, for uplink or downlink. Each configuration supports commands from a Synchronization Controller and a special synchronization mode. In this document the software and hardware details are provided along with a user guide for the board.

Addison, Robin

1990-08-01

115

Phoenix's Robotic Arm  

Science.gov (United States)

This is a lesson about programming and communications in space exploration. Learners will simulate sending commands to operate a robotic arm to complete a task. This is lesson 13 of 16 in the MarsBots learning module.

116

Analysis of the polar crane pendant cable from Three Mile Island - Unit 2  

International Nuclear Information System (INIS)

The pendant cable to the polar crane in Three Mile Island - Unit 2 (TMI-2) was suspended near the center of the containment during the March 1979 accident. It sustained considerable thermal damage from the hydrogen burn that occurred. The cable was removed from TMI-2 and cut into sections, which were then analyzed to assess the extent of damage and learn as much as possible about the accident environment (by studying its effect on the cable). Both electrical and materials tests were employed in the analyses, which produced information about the hydrogen burn and contamination levels in containment. 10 refs., 24 figs

117

Moving protons with pendant amines: proton mobility in a nickel catalyst for oxidation of hydrogen.  

Science.gov (United States)

Proton transport is ubiquitous in chemical and biological processes, including the reduction of dioxygen to water, the reduction of CO(2) to formate, and the production/oxidation of hydrogen. In this work we describe intramolecular proton transfer between Ni and positioned pendant amines for the hydrogen oxidation electrocatalyst [Ni(P(Cy)(2)N(Bn)(2)H)(2)](2+) (P(Cy)(2)N(Bn)(2) = 1,5-dibenzyl-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane). Rate constants are determined by variable-temperature one-dimensional NMR techniques and two-dimensional EXSY experiments. Computational studies provide insight into the details of the proton movement and energetics of these complexes. Intramolecular proton exchange processes are observed for two of the three experimentally observable isomers of the doubly protonated Ni(0) complex, [Ni(P(Cy)(2)N(Bn)(2)H)(2)](2+), which have N-H bonds but no Ni-H bonds. For these two isomers, with pendant amines positioned endo to the Ni, the rate constants for proton exchange range from 10(4) to 10(5) s(-1) at 25 °C, depending on isomer and solvent. No exchange is observed for protons on pendant amines positioned exo to the Ni. Analysis of the exchange as a function of temperature provides a barrier for proton exchange of ?G(‡) = 11-12 kcal/mol for both isomers, with little dependence on solvent. Density functional theory calculations and molecular dynamics simulations support the experimental observations, suggesting metal-mediated intramolecular proton transfers between nitrogen atoms, with chair-to-boat isomerizations as the rate-limiting steps. Because of the fast rate of proton movement, this catalyst may be considered a metal center surrounded by a cloud of exchanging protons. The high intramolecular proton mobility provides information directly pertinent to the ability of pendant amines to accelerate proton transfers during catalysis of hydrogen oxidation. These results may also have broader implications for proton movement in homogeneous catalysts and enzymes in general, with specific implications for the proton channel in the Ni-Fe hydrogenase enzyme. PMID:21595478

O'Hagan, Molly; Shaw, Wendy J; Raugei, Simone; Chen, Shentan; Yang, Jenny Y; Kilgore, Uriah J; DuBois, Daniel L; Bullock, R Morris

2011-09-14

118

Fibers of YBa2Cu3O7 by pendant drop melt extraction  

International Nuclear Information System (INIS)

This paper reports fibers of YBa2 Cu 3 O 7 produced by pendant drop melt extraction, a technique in which the end of a rod of YBa2 Cu 3 O 7 is melted with a hydrogen-oxygen torch and lowered onto the edge of a spinning wheel. Fibers up to 10 cm in length have been produced; usually the lateral dimensions were in the range from 20 to 125 ? m. The fibers required a heat treatment to make them superconduction; the T c of heat treated fibers ranged from 88 to 90 K

119

A polyacetylene derivative with pendant TEMPO group as cathode material for rechargeable batteries  

Science.gov (United States)

A composite cathode material comprised of a polyacetylene derivative with pendant TEMPO electro-active groups and graphite has been obtained and successfully utilized in a rechargeable battery against a Li anode. The battery has an initial specific discharge capacity of 102.6 mAh/g and an initial specific energy capacity of 315.9 mWh/g. This specific energy capacity is very high compared to today's conventional lithium-ion batteries with cathodes made of LiFePO4, LiCoO2, LiMnO2, etc. The battery has retained 77% of its energy capacity after 40 charge-discharge cycles.

Bahceci, Sumeyye; Esat, Burak

2013-11-01

120

Rapid Deceleration-Driven Wetting Transition during Pendant Drop Deposition on Superhydrophobic Surfaces  

Science.gov (United States)

A hitherto unknown mechanism for wetting transition is reported. When a pendant drop settles upon deposition, there is a virtual “collision” where its center of gravity undergoes rapid deceleration. This induces a high water hammer-type pressure that causes wetting transition. A new phase diagram shows that both large and small droplets can transition to wetted states due to the new deceleration driven and the previously known Laplace mechanisms, respectively. It is explained how the attainment of a nonwetted Cassie-Baxter state is more restrictive than previously known.

Kwon, Hyuk-Min; Paxson, Adam T.; Varanasi, Kripa K.; Patankar, Neelesh A.

2011-01-01

 
 
 
 
121

Effect of pendant group structure on the hydrolytic stability of polyaspartamide polymers under physiological conditions.  

Science.gov (United States)

We describe the synthesis of metal chelating polymers based on polyaspartamide and polyglutamide backbones as carriers for (111)In in radioimmunoconjugates. These polymers [PAsp(DTPA), PGlu(DTPA)] have a biotin end group and diethylenetriaminepentaacetic acid (DTPA) chelators attached to the primary amines of the diethylenetriamine (DET) pendant groups of biotin-poly{N'-[N-(2-aminoethyl)-2-aminoethyl]aspartamide} [PAsp(DET)] and of biotin-poly{N'-[N-(2-aminoethyl)-2-aminoethyl]glutamide} [PGlu(DET)]. Like Asn-containing proteins and polypeptides, polyaspartamides undergo uncatalyzed degradation under model physiological conditions (10 mM phosphate buffer, pH 7.4, 150 mM NaCl). We studied the uncatalyzed degradation of the polyaspartamide polymers by size exclusion chromatography and found that the degradation rate was sensitive to the nature of the pendant groups. The metal-free polymer underwent somewhat slower degradation than the corresponding polymers in which the DTPA groups were saturated with Eu(3+) or In(3+), but even after 14 days, substantial fractions of the polymers survived. We conclude that these polymers undergo negligible degradation on the time scale (24-48 h) of radioimmunotherapy treatment of tumors with (111)In. From a mechanistic perspective, we note that these degradation rates are on the order of the deamidation rates reported [J. Peptide Res. 2004, 63, 426] for Asn-containing pentapeptides, with half-times on the order of 10 days, but much slower than the rapid decay (hours) reported recently [Biomaterials 2010, 31, 3707] for poly{N'-[N-(2-aminoethyl)-2-aminoethyl]aspartamide} itself. This variation in degradation rate can be explained in terms of the influence of positive charges on the pendant group enhancing the acidity of the side-chain amide nitrogen of the aspartamide repeat unit. The DET pendant group is positively charged at pH 7, but in indium-loaded PAsp(DTPA) this charge is offset by the net negative charge of the DTPA-In complex. PMID:22471754

Lu, Yijie; Chau, Mokit; Boyle, A J; Liu, Peng; Niehoff, Ansgar; Weinrich, Dirk; Reilly, Raymond M; Winnik, Mitchell A

2012-05-14

122

Hello to Arms  

Science.gov (United States)

This image highlights the hidden spiral arms (blue) that were discovered around the nearby galaxy NGC 4625 by the ultraviolet eyes of NASA's Galaxy Evolution Explorer. The image is composed of ultraviolet and visible-light data, from the Galaxy Evolution Explorer and the California Institute of Technology's Digitized Sky Survey, respectively. Near-ultraviolet light is colored green; far-ultraviolet light is colored blue; and optical light is colored red. As the image demonstrates, the lengthy spiral arms are nearly invisible when viewed in optical light while bright in ultraviolet. This is because they are bustling with hot, newborn stars that radiate primarily ultraviolet light. The youthful arms are also very long, stretching out to a distance four times the size of the galaxy's core. They are part of the largest ultraviolet galactic disk discovered so far. Located 31 million light-years away in the constellation Canes Venatici, NGC 4625 is the closest galaxy ever seen with such a young halo of arms. It is slightly smaller than our Milky Way, both in size and mass. However, the fact that this galaxy's disk is forming stars very actively suggests that it might evolve into a more massive and mature galaxy resembling our own. The armless companion galaxy seen below NGC 4625 is called NGC 4618. Astronomers do not know why it lacks arms but speculate that it may have triggered the development of arms in NGC 4625.

2005-01-01

123

Armed conflict and child health.  

Science.gov (United States)

Armed conflict has a major impact on child health throughout the world. One in six children worldwide lives in an area of armed conflict and civilians are more likely to die than soldiers as a result of the conflict. In stark contrast to the effect on children, the international arms trade results in huge profits for the large corporations involved in producing arms, weapons and munitions. Armed conflict is not inevitable but is an important health issue that should be prevented. PMID:21393303

Rieder, Michael; Choonara, Imti

2012-01-01

124

The Gem Lake shear zone: Cretaceous dextral transpression in the Northern Ritter Range pendant, eastern Sierra Nevada, California  

Science.gov (United States)

The Gem Lake shear zone is a northwest striking, steeply dipping, dextral transpressional shear zone that provides the first direct evidence for dextral deformation in wall-rock pendants in the central part of the Sierra Nevada batholith. The Gem Lake shear zone is a minimum of 30 km in length and extends at least from the north end of the Northern Ritter Range pendant to the southeast edge of the Ritter Range pendant. The amount of displacement on the zone is uncertain, but matching fault slivers of Pennsylvanian(?) marble in the Northern Ritter Range pendant to similar exposures north of the Mount Morrison pendant suggests a minimum dextral offset of 20 km. The Gem Lake shear zone was active in early Late Cretaceous time, from before 91 Ma (the age of the syntectonic granodiorite of Kuna Crest) to at least 80 Ma (40Ar/39Ar age of syndeformational mica from the shear zone in the Ritter Range pendant). Deformation in the Gem Lake shear zone is characterized by combined dextral simple shear and subvertical stretching, which are variably partitioned in anastomosing high-strain zones. In the shear zone at Gem Lake, predominantly dextral deformation is indicated by porphyroclast asymmetries, S-C fabric, and asymmetric crenulations; a component of subvertical stretching is indicated by a moderately to steeply plunging stretching lineation. In a segment of the shear zone at Kuna Crest, a strongly developed stretching lineation indicates predominantly subvertical stretching, with a lesser component of dextral strike slip. The Gem Lake shear zone is considered to be part of a proposed regional system of shear zones in the eastern Sierra Nevada, the Sierra Crest shear zone system. This dextral transpressional system was active prior to, and synchronous with, intrusion of the Late Cretaceous Sierra Nevada batholiths; deformation ceased shortly after pluton emplacement. The Sierra Crest shear zone system includes possibly related shear zones as far north as Saddlebag Lake pendant and at least as far south as Oak Creek pendant and the Owens Valley, indicating a possible strike length greater than 150 km.

Greene, David C.; Schweickert, Richard A.

1995-08-01

125

Arm To Arm Interface Using Embedded C  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Embedded systems are the most emerging field in these recent years. In this paper a different number of ARM processors (LPC2148 and LPC2378) are interconnected using C for distributed services. N numbers of processors are connected as the network and each processing devices are interlinked with each other, so that the each data that is processed by the devices and it can be used by the other device to activate their entire process. All the processed data’s are communicated to other device t...

Mohanraj.C; Manivannan.D

2013-01-01

126

Inorganic syntheses, v.64  

CERN Document Server

The Inorganic Synthesis Series provides all users of inorganic substances with detailed and foolproof procedures for the preparation of important and timely compounds. This new volume includes information on water-solubilizing ligands for organometallics, labile ligand complexes, and the syntheses of cluster compounds and hydrides.

Darensbourg, Marcetta York

2009-01-01

127

Arm To Arm Interface Using Embedded C  

Directory of Open Access Journals (Sweden)

Full Text Available Embedded systems are the most emerging field in these recent years. In this paper a different number of ARM processors (LPC2148 and LPC2378 are interconnected using C for distributed services. N numbers of processors are connected as the network and each processing devices are interlinked with each other, so that the each data that is processed by the devices and it can be used by the other device to activate their entire process. All the processed data’s are communicated to other device through Xbee interface card. LPC2148 and LPC2378 ARM processors are used in this prototype and winXtalk is used as a software terminal window. In this paper, the ultimate benefits of multiple processor interactions related to the embedded applications and design issues of processor interconnection are discussed. The features of multiple processor interaction in inter process communication and executions of embedded multitasking are also discussed. In modern embedded computing platform, embedded processor used in various applications like home automation, industrial control, medical system, access control, etc. In this paper, using embedded processor interactions, the several data communication is established.

Mohanraj.C

2013-02-01

128

Arms Industry limited  

Energy Technology Data Exchange (ETDEWEB)

The intent of this study is to give an overview of the present state of the world arms industry. It is an empirical account of the size of the industry and particularly its present problems. The authors examine the economic pressures that affect the international arms trade. Specifically, it raises the question of how dependent the industry is on weapons production and exports, and whether there are any alternatives. Export dependence of the major weapons producing countries is a major focus. The book focus`s on private industry as opposed to examination of national governments. Despite the passing of the Cold War and some brief post-Gulf War euphoria about the possibility of greater restrain on the part of weapons exporters, the conventional arms trade is alive and well, albeit with new variations.

Wulf, H. [ed.

1993-12-31

129

Arming ethnic conflict  

Energy Technology Data Exchange (ETDEWEB)

One of the more interesting side effects of the end of the Cold War has been the increased international awareness of the dangers posed by the continuing flood of conventional weapons worldwide. Until recently, debates over the arms trade were merely a sideshow; most attention was focused on international security and arms control. Yet even as the international community begins to take a closer and more serious look at the arms trade, one of its most deadly and anarchic aspects - the transfer of weapons to sub-state groups - is being overlooked. Discussions tend to focus on major conventional weapons such as combat aircraft, naval vessels, armored vehicles and long-range missiles - weapons that symbolize international warfare. Greater control over the trade in major conventional armaments is essential to building regional peace and security. But these controls will have little effect on the weapons most likely to be used in war.

Karp, A.

1993-09-01

130

THE INTERNATIONAL ARMS TRADE  

Directory of Open Access Journals (Sweden)

Full Text Available Everyone is aware of the existence of the arms trade but few have any idea of the nature of its workings or of its implications, both actual and potential. Some information as to the methods employed in the sale of arms was made available via the Lockheed and Northrop scandals, but by and large this was information that could not be evaluated in terms of all the elements of the system. It is the aim of this article to provide some insight into the various facets that go together to make up the arms trade, in this way by no means giving an all-embracing account but merely providing some interesting facts and figures.

M. Japhet

2012-02-01

131

Development of electrochemical sensors for nano scale Tb(III) ion determination based on pendant macrocyclic ligands  

International Nuclear Information System (INIS)

The two macrocyclic pendant ligands 3,4,5:12,13,14-dipyridine-2,6,11, 15-tetramethyl-1,7,10,16-tetramethylacrylate -1,4,7,10,13, 16-hexaazacyclooctadeca-3,13-di ene (L1) and 3,4,5:12,13,14-dipyridine-2,6,11,15-tetramethyl-1,7,10,16-tetra(2-cyano ethane)-1,4,7,10,13,16-hexaazacyclooctadeca-3,13-diene (L2) have been synthesized and explored as neutral ionophores for preparing poly(vinylchloride) (PVC) based membrane sensors selective to Tb(III) ions. Effects of various plasticizers and anion excluders were studied in detail and improved performance was observed. The best performance was obtained for the membrane sensor having a composition of L1: PVC:1-CN:NaTPB in the ratio of 6: 32: 58: 4 (w/w; mg). The performance of the membrane based on L1 was compared with polymeric membrane electrode (PME) as well as with coated graphite electrode (CGE). The electrodes exhibit Nernstian slope for Tb3+ ions with limits of detection of 3.4 x 10-8 mol L-1 for PME and 5.7 x 10-9 mol L-1 for CGE. The response time for PME and CGE was found to be 10 s and 8 s, respectively. The potentiometric responses are independent of the pH of the test solution in the pH range 3.0-7.5 for PME and 2.0-8.5 for CGE. The CGE has found to work satisfactorily in partially non-aqueous media upto 30% (v/v) content of methanol, ethanol and 20% (v/v) content of acetonitrile and could be used for a period of 5 moile and could be used for a period of 5 months. The CGE was used as indicator electrode in the potentiometric titration of Tb3+ ions with EDTA and in determination of fluoride ions in various samples. It can also be used in direct determination of Tb3+ ions in tap water and various binary mixtures with quantitative results

132

Robotic Arm Unwrapped  

Science.gov (United States)

This image, taken shortly after NASA's Phoenix Mars Lander touched down on the surface of Mars, shows the spacecraft's robotic arm in its stowed configuration, with its biobarrier successfully unpeeled. The 'elbow' of the arm can be seen at the top center of the picture, and the biobarrier is the shiny film seen to the left of the arm. The biobarrier is an extra precautionary measure for protecting Mars from contamination with any bacteria from Earth. While the whole spacecraft was decontaminated through cleaning, filters and heat, the robotic arm was given additional protection because it is the only spacecraft part that will directly touch the ice below the surface of Mars. Before the arm was heated, it was sealed in the biobarrier, which is made of a trademarked film called Tedlar that holds up to baking like a turkey-basting bag. This ensures that any new bacterial spores that might have appeared during the final steps before launch and during the journey to Mars will not contact the robotic arm. After Phoenix landed, springs were used to pop back the barrier, giving it room to deploy. The base of the lander's Meteorological Station can be seen in this picture on the upper left. Because only the base of the station is showing, this image tells engineers that the instrument deployed successfully. The image was taken on landing day, May 25, 2008, by the spacecraft's Surface Stereo Imager. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

2008-01-01

133

PHENIX Muon Arms  

International Nuclear Information System (INIS)

The PHENIX Muon Arms detect muons at rapidities of |y|=(1.2-2.4) with full azimuthal acceptance. Each muon arm must track and identify muons and provide good rejection of pions and kaons (?10-3). In order to accomplish this we employ a radial field magnetic spectrometer with precision tracking (Muon Tracker) followed by a stack of absorber/low resolution tracking layers (Muon Identifier). The design, construction, testing and expected run parameters of both the muon tracker and the muon identifier are described

134

Reaction with glutathione. A possible mechanism involved in rodent brain retention of a 99mTc SNS/S complex containing a pendant ester functionality  

International Nuclear Information System (INIS)

The synthesis, characterization of MvO([CH3CH2N(CH2CH2S)2](p-S-Ph-COOCH2-CH3)) (M:99mTc: I, Re: II) is presented in this work, where a pendant ester function is attached to the monothiolate ligand. Chemical structure of I is established after chromatographic comparison with II, synthesized in macroscopic amounts. Complex II is fully characterized by classical methods of analysis showing that the compound adopts a distorted trigonal bipyramidal configuration around the metal. The two sulfur atoms of the tridentate ligand and the oxo group form the basal plane, while the remaining nitrogen atom of the tridentate ligand and the sulfur atom of the monothiolate ligand occupy the apices of the bipyramid. In vitro challenge experiments with glutathione (GSH) in neutral aqueous medium demonstrate, that I suffers nucleophilic attack by GSH and thereby transformation to a more hydrophilic daughter metal compound. Formation of the latter depends on time and GSH concentration. Tissue distribution in mice shows minor retention in brain. As rodent brain presents no esterases to hydrolyze the ester group of I, while the intracerebral content in GSH amounts to 2 mM, the above described mechanism is suspected for the observed brain retention. However, in primate brain cells retention of I may additionally involve the hydrolysis of the ester function to the corresponding acid, as already revealed by preliminary in vitro experiments using esterase incubates. (author)

135

Synthesis and chiral recognition of nickel(II) macrocyclic complex with (R)-naphthylethyleneamine pendant groups and its self-assembled framework.  

Science.gov (United States)

A novel nickel(II) hexaaza macrocyclic complex, [Ni(L(R,R))](ClO(4))(2) (1), containing chiral pendant groups was synthesized by an efficient one-pot template condensation and characterized (L(R,R) ?1,8-di((R)-?-methylnaphthyl)-1,3,6,8,10,13-hexaazacyclotetradecane). The crystal structure of compound 1 was determined by single-crystal X-ray analysis. The complex was found to have a square-planar coordination environment for the nickel(II) ion. Open framework [Ni(L(R,R))](3) [C(6)H(3)(COO)(3)](2) (2) was constructed from the self-assembly of compound 1 with deprotonated 1,3,5-benzenetricarboxylic acid, BTC(3-). Chiral discrimination of rac-1,1'-bi-2-naphthol and rac-2,2,2-trifluoro-1-(9-anthryl)ethanol was performed to determine the chiral recognition ability of the chiral complex (1) and its self-assembled framework (2). Binaphthol showed a good chiral discrimination on the framework (2). The optimum experimental conditions for the chiral discrimination were examined by changing the weight ratio between the macrocyclic complex 1 or self-assembled framework 2 and racemates. The detailed synthetic procedures, spectroscopic data including single-crystal X-ray analysis, and the results of the chiral recognition for the compounds are described. PMID:23108606

Min, Kil Sik; Park, Mi Jung; Ryoo, Jae Jeong

2013-01-01

136

Effects of wake dynamics on infrared measurements of particle cloud temperatures in the superheater pendant region of utility boilers  

International Nuclear Information System (INIS)

Turbulent particle cloud temperatures in the superheater pendant region are critical in coal-fired utility boilers not only for the interactions between turbulence and radiative heat transfer, but also for the ash deposit slagging and fouling on superheater tubes. The false infrared particle temperature fluctuations due to the pendant wake dynamics may cause large errors in modeling of the radiation transport. This paper presents a model to theoretically analyze the effects of wake dynamics on the false infrared particle cloud temperature fluctuations in the superheater pendant region. The preferred frequency in the power spectra and the root mean square temperature fluctuations are predicted theoretically and the effects of utility boiler operating conditions are analyzed. The preferred frequency is twice the vortex shedding frequency and is proportional to the flue gas velocity, and inversely proportional to the superheater tube diameter. The root mean square temperature fluctuations are proportional to the initial particle volume fraction and inversely proportional to the 1.04 power of the particle mass weighted mean diameter. -- Highlights: ? Superheater pendant wake causes the false infrared particle temperature fluctuations. ? Infrared particle temperatures fluctuate at twice the vortex shedding frequency. ? Root mean square temperature fluctuation is proportional to particle volume fraction. ? The present model predicts using only the utility boiler operating conditions

137

Talking to armed groups  

Directory of Open Access Journals (Sweden)

Full Text Available To persuade fighters to respect the rules of warfare, one must understand why violations occur, how armed groups operate, what can be done to prevent violations and how to engage in dialogue with these groups. This article reflects the ICRC’s many years of experience in this area....

Olivier Bangerter

2011-03-01

138

An Athletic Arms Race  

Science.gov (United States)

Myles Brand is a person of unquestioned integrity and high principle. As president of the National Collegiate Athletic Association (NCAA), he has been asked to fend off an unruly mob with a switch. In the present environment for collegiate sports, his chances for success are slight, at best. What Brand and the NCAA face today is a very real "arms

Budig, Gene A.

2007-01-01

139

Kiikuv maja / Anu Arm  

Index Scriptorium Estoniae

Eesti Kunstiakadeemia esimese kursuse arhitektuuriüliõpilaste II semestri töö. Juhendaja arhitekt Andres Alver, ehitamise Pedaspeale organiseeris suvepraktika juhendaja arhitekt Jaan Tiidemann. Autor Anu Arm, kaasa töötasid ja valmis ehitasid: Ott Alver, Maarja Elm, Mari Hunt, Alvin Järving, Marten Kaevats, Riho Kerge, Reedik Poopuu, Anu Põime, Helen Rebane, Kaisa Saarva, Martin Tago, Reet Volt. Valmis: 19. VIII 2006

Arm, Anu

2006-01-01

140

Total syntheses of tubulysins.  

Science.gov (United States)

The total syntheses of tetrapeptides tubulysins?D (1?b), U (1?c), and V (1?d), which are potent tubulin polymerization inhibitors, are described. The synthesis of Tuv (2), an unusual amino acid constituent of tubulysins, includes an 1,3-dipolar cycloaddition reaction of chiral nitrone D-6 derived from D-gulose with N-acryloyl camphor sultam (-)-9 employing the double asymmetric induction, whereas the synthesis of Tup (20), another unusual amino acid, involves a stereoselective Evans aldol reaction of (Z)-boron enolate generated from (S)-4-isopropyl-3-propionyl-2-oxazolidinone with N-protected phenylalaninal and a subsequent Barton deoxygenation protocol. We accomplished the total syntheses of tubulysins?U (1?c) and V (1?d) by using these methodologies, in which the isoxazolidine ring was used as the effective protective group for ?-amido alcohol functionality. Furthermore, to understand the structure-activity relationship of tubulysins, we synthesized tubulysin?D (1?b) and cyclo-tubulysin?D (1?e) from 2-Me and 20, and ent-tubulysin?D (ent-1?d) from ent-2-Me and ent-20, respectively. The preliminary results regarding their biological activities are also reported. PMID:20734394

Shibue, Taku; Hirai, Toshihiro; Okamoto, Iwao; Morita, Nobuyoshi; Masu, Hyuma; Azumaya, Isao; Tamura, Osamu

2010-10-11

 
 
 
 
141

Star Formation in Spiral Arms  

CERN Document Server

The origin and types of spiral arms are reviewed with an emphasis on the connections between these arms and star formation. Flocculent spiral arms are most likely the result of transient instabilities in the gas that promote dense cloud formation, star formation, and generate turbulence. Long irregular spiral arms are usually initiated by gravitational instabilities in the stars, with the gas contributing to and following these instabilities, and star formation in the gas. Global spiral arms triggered by global perturbations, such as a galaxy interaction, can be wavemodes with wave reflection in the inner regions. They might grow and dominate the disk for several rotations before degenerating into higher-order modes by non-linear effects. Interstellar gas flows through these global arms, and through the more transient stellar spiral arms as well, where it can reach a high density and low shear, thereby promoting self-gravitational instabilities. The result is the formation of giant spiral arm cloud complexes,...

Elmegreen, Bruce G

2011-01-01

142

Cooperative assembly of Zn cross-linked artificial tripeptides with pendant hydroxyquinoline ligands.  

Science.gov (United States)

An artificial peptide with three pendant hydroxyquinoline (hq) ligands on a palindromic backbone was designed and used to form multimetallic assemblies. Reaction of the tripeptide with zinc acetate led to a highly fluorescent tripeptide duplex with three Zn(II) coordinative cross-links. The binding process was monitored using spectrophotometric absorbance and emission titrations; NMR spectroscopy and mass spectrometry confirmed the identity and stoichiometry of the product structure. Titrations monitoring duplex formation of the zinc-tripeptide structure had a sigmoidal shape, equilibrium constant larger than the monomeric analogue, and a Hill coefficient >1, all of which indicate positive cooperativity. Photophysical characterization of the quantum yield, excited state lifetime, and polarization anisotropy are compared with the monometallic zinc-hq analogue. A higher than expected quantum yield for the trimetallic complex suggests a structure in which the central chromophore is shielded from solvent by ?-stacking with neighboring Zn(II) complexes. PMID:23039157

Zhang, Meng; Gallagher, Joy A; Coppock, Matthew B; Pantzar, Lisa M; Williams, Mary Elizabeth

2012-11-01

143

Reduction of Oxygen Catalyzed by Nickel Diphosphine Complexes with Positioned Pendant Amines  

International Nuclear Information System (INIS)

Nickel(II) bis(diphosphine) complexes that contain positioned bases in the second coordination sphere have been found to catalyze the reduction of O2 with H2 to selectively form water. The complexes also serve as electrocatalysts for the reduction of O2 with the addition of a weak acid. In contrast, a closely related nickel diphosphine complex without the positioned bases is catalytically inactive for O2 reduction. These results indicate that pendant bases in synthetic catalysts for O2 reduction can play a similar role to proton relays in enzymes, and that such relays should be considered in the design of catalysts for multi-electron and multi-proton reactions.

144

Pendant thiol groups-attached Pd(II) for initiating metal deposition  

International Nuclear Information System (INIS)

A new activation method has been developed for initiating electroless metal deposition on silicon substrates without SnCl2 sensitization and roughening condition. Silicon wafers are first coated with thiol-terminated self-assembled monolayers (SAMs), and then catalyzed with a stable tin-free Pd(II)-based colloidal solution. Atomic force microscopy (AFM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were used to characterize the step-by-step surfaces and study the binding mechanism of Pd(II) with SAMs onto surfaces. Results show that Pd(II) oligomer particles are chemisorbed on pendant thiol surfaces through S-Pd bonds. This process involves fewer steps than the conventional Sn/Pd combined activation one. Furthermore, the chemical bound initiator possesses longevity and can be stored for a long time before metallization

145

Motion driven by the interface. [pendant drop surface tension in microgravity  

Science.gov (United States)

Due to the reduction in buoyant forces aboard orbiting spacecraft such as the Space Shuttle, fluid motion driven by gradients in interfacial tension will be important in the processing of materials in space. In this paper, preliminary results from a study of surface tension driven flow in a pendant drop are reported. The drop is heated from above, and the resulting temperature gradients on the drop surface give rise to interfacial tension gradients. These, in turn, drive a circulation in the drop which is made visible by suitable tracers. The velocities are measured using a video technique, and the data on core velocities are found to agree well with results from a predictive theoretical model.

Jayaraj, K.; Cole, R.; Subramanian, R. S.

1983-01-01

146

High-efficiency bipolar electroluminescent polymer containing an oxadiazole pendant group  

International Nuclear Information System (INIS)

By introducing electron-deficient 1,3,4-oxadiazole pendant units into poly(p-phenylenevinylene) as a side chain, we have achieved high-performance polymer light-emitting diodes with aluminum (Al) electrodes and a luminance efficiency of ? 20 cd/A. These results are attributed to the high electron affinity and the good electron transport of the oxadiazole units, which facilitate electron injection from the Al electrode, and bipolar transport in the active layer. The 'bipolar' nature of this system is strongly supported by the time-of-flight measurements, which exhibit symmetric photocurrent transients between the electrons and holes, these transients are mainly responsible for the excellent performance of this system because the help achieve charge balance in the devices.

147

Proton and Electron Additions to Iron (II) Dinitrogen Complexes Containing Pendant Amines  

Energy Technology Data Exchange (ETDEWEB)

We describe a single site cis-(H)FeII-N2 complex, generated by the protonation of an iron-carbon bond of a "reduced" iron complex, that models key aspects of proposed protonated intermediates of the E4 state of nitrogenase. The influence on N2 binding from the addition of protons to the pendant amine sites in the second coordination sphere is described. Furthermore, the addition of electrons to the protonated complexes results in H2 loss. The mechanism of H2 loss is explored to draw a parallel to the origin of H2 loss (homolytic or heterolytic) and the nature of N2 coordination in intermediates of the E4 state of nitrogenase.

Heiden, Zachariah M.; Chen, Shentan; Labios, Liezel AN; Bullock, R. Morris; Walter, Eric D.; Tyson, Elizabeth L.; Mock, Michael T.

2014-03-10

148

ARM User Survey Report  

Energy Technology Data Exchange (ETDEWEB)

The objective of this survey was to obtain user feedback to, among other things, determine how to organize the exponentially growing data within the Atmospheric Radiation Measurement (ARM) Climate Research Facility, and identify users’ preferred data analysis system. The survey findings appear to have met this objective, having received approximately 300 responses that give insight into the type of work users perform, usage of the data, percentage of data analysis users might perform on an ARM-hosted computing resource, downloading volume level where users begin having reservations, opinion about usage if given more powerful computing resources (including ability to manipulate data), types of tools that would be most beneficial to them, preferred programming language and data analysis system, level of importance for certain types of capabilities, and finally, level of interest in participating in a code-sharing community.

Roeder, LR

2010-06-22

149

Programmable electronic synthesized capacitance  

Science.gov (United States)

A predetermined and variable synthesized capacitance which may be incorporated into the resonant portion of an electronic oscillator for the purpose of tuning the oscillator comprises a programmable operational amplifier circuit. The operational amplifier circuit has its output connected to its inverting input, in a follower configuration, by a network which is low impedance at the operational frequency of the circuit. The output of the operational amplifier is also connected to the noninverting input by a capacitor. The noninverting input appears as a synthesized capacitance which may be varied with a variation in gain-bandwidth product of the operational amplifier circuit. The gain-bandwidth product may, in turn, be varied with a variation in input set current with a digital to analog converter whose output is varied with a command word. The output impedance of the circuit may also be varied by the output set current. This circuit may provide very small ranges in oscillator frequency with relatively large control voltages unaffected by noise.

Kleinberg, Leonard L. (inventor)

1987-01-01

150

AES i ARM procesori  

Directory of Open Access Journals (Sweden)

Full Text Available Potreba za zaštitom informacija dovodi do velikih problema u izradi prenosivih ure?aja kojima su limitirani snaga, memorija i energija. Ukoliko se takvim ure?ajima dodaju koprocesori, koji treba da obavljaju funkcije kriptozaštite, njihove se dimenzije pove?avaju, pojavljuje se nefleksibilnost pa cena ure?aja raste i do nekoliko puta. Na drugoj strani, algoritmi za zaštitu podataka su ?esto memorijski zahtevni, a zbog velikog broja operacija koje je potrebno izvršavati u procesima šifrovanja i dešifrovanja, koprocesori ?esto uspore rad osnovnog procesora. Za jedan od standarda za kriptozaštitu, AES, NIST je prihvatio Rijndaelov blokovski algoritam sa dužinom ulaznog i izlaznog bloka od 128 b, i dužinama šifarskog klju?a od 128 b, 192 b i 256 b. Zbog karakteristika male potrošnje, 32-bitske arhitekture i brzog izvršavanja instrukcija, ARM procesori mogu da realizuju kriptozaštitu podataka, izme?u ostalog i AES-om, a da ne opterete glavne procese u sistemima u kojima se koriste. Tehnologija ARM-a zašti?ena je kao intelektualna svojina, pa je veliki broj proizvo?a?a koristi za razvoj sopstvenih proizvoda, što je rezultovalo ?injenicom da je u svetu proizvedeno preko 2 milijarde ?ipova koji su bazirani na ovoj tehnologiji. U radu su prikazane mogu?nosti za poboljšanja u izvršenju algoritma AES primenom najnovijih verzija ARM procesora.

Danijela D. Proti?

2013-12-01

151

Thermochemical and Mechanistic Studies of Electrocatalytic Hydrogen Production by Cobalt Complexes Containing Pendant Amines  

Energy Technology Data Exchange (ETDEWEB)

Two cobalt(tetraphosphine) complexes [Co(PnC-PPh22NPh2)(CH3CN)](BF4)2 with a tetradentate phosphine ligand (PnC-PPh22NPh2 = 1,5-diphenyl-3,7-bis((diphenylphosphino)alkyl)-1,5-diaza-3,7-diphosphacyclooctane; alkyl = (CH2)2, n = 2 (L2); (CH2)3, n = 3 (L3)) have been studied for electrocatalytic hydrogen production using 1:1 [(DMF)H]+:DMF. A turnover frequency of 980 s–1 with an overpotential of 1210 mV was measured for [CoII(L2)(CH3CN)]2+, and a turnover frequency of 980 s–1 with an overpotential of 930 mV was measured for [CoII(L3)(CH3CN)]2+. Addition of water increases the turnover frequency of [CoII(L2)(CH3CN)]2+ to 19,000 s–1. The catalytic wave for each of these complexes occurs at the reduction potential of the corresponding HCoIII complex. Comprehensive thermochemical studies of [CoII(L2)(CH3CN)]2+ and [CoII(L3)(CH3CN)]2+ and species derived from them by addition/removal of protons/electrons were carried out using values measured experimentally and calculated using DFT. Notably, HCoI(L2) and HCoI(L2) were found to be remarkably strong hydride donors, with HCoI(L2) being a better hydride donor than BH4-. Mechanistic studies of these catalysts reveal that H2 formation can occur by protonation of a HCoII intermediate, and that the pendant amines of these complexes facilitate proton delivery to the cobalt center. The rate-limiting step for catalysis is a net intramolecular isomerization of the protonated pendant amine from the non-productive exo-isomer to the productive endo isomer. We thank Dr. Shentan Chen for many helpful discussions. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Computational resources were provided at the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Wiedner, Eric S.; Appel, Aaron M.; DuBois, Daniel L.; Bullock, R. Morris

2013-12-16

152

Anionic N-heterocyclic carbenes (NHCs): a versatile route to saturated NHCs bearing pendant weakly coordinating anions.  

Science.gov (United States)

A versatile methodology is reported for the synthesis of anionic NHCs featuring a 5-, 6-, or 7-membered saturated heterocyclic core. Lewis acid promoted exocyclic ring closure generates systems in which the pendant borate functionality is incorporated via a CH2 linker, allowing for electronic and steric isolation of the anionic component. Hence, a library of NHCs can be accessed which incorporate metal binding environments essentially identical to the neutral parent donors, but with significantly altered solubility profiles. PMID:25198297

Phillips, Nicholas; Tirfoin, Rémi; Aldridge, Simon

2014-11-01

153

Best Arm Identification in Multi-Armed Bandits  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider the problem of finding the best arm in a stochastic multi-armed bandit game. The regret of a forecaster is here defined by the gap between the mean reward of the optimal arm and the mean reward of the ultimately chosen arm. We propose a highly exploring UCB policy and a new algorithm based on successive rejects. We show that these algorithms are essentially optimal since their regret decreases exponentially at a rate which is, up to a logarithmic factor, the best possible. However...

Audibert, Jean-yves; Bubeck, Se?bastien

2010-01-01

154

Disarmament and arms control  

International Nuclear Information System (INIS)

This report discusses how far science and technology can provide methods of making arms control and disarmament agreements more controlable in an objective way. Two case studies have been considered, the test ban treaty and the verification of the number of strategic nuclear weapons. These lead to the conclusion that both science and politics are closely interwoven and that within what appear to be scientific arguments, political positions are being defended. Consequently scientists and technologists and the contexts in which they work, play a prominent role. (C.F.)

155

Synthesis of poly(ester-carbonate) with a pendant acetylcholine analog for promoting neurite growth.  

Science.gov (United States)

The modification of biodegradable polyesters with bioactive molecules has become an important strategy for controlling neuron adhesion and neurite outgrowth in nerve regeneration. In this study we report a biodegradable poly(ester-carbonate) with a pendant acetylcholine analog, which a neurotransmitter for the enhancement of neuron adhesion and outgrowth. The acetylcholine-functionalized poly(ester-carbonate) (Ach-P(LA-ClTMC)) was prepared by copolymerizing l-lactide (LA) and 5-methyl-5-chloroethoxycarbonyl trimethylene carbonate (ClTMC), followed by quaternization with trimethylamine. The acetylcholine analog content could be modulated by changing the molar feeding fraction of ClTMC. The incorporation of the acetylcholine analog improved the hydrophilicity of the films, but the acetylcholine analog content did not significantly influence the surface morphology of the acetylcholine-functionalized films. The results of PC12 cell culture showed that the acetylcholine analog promoted cell viability and neurite outgrowth in a concentration-dependent manner. The longest length of neurite and the percentage of cells bearing neurites were obtained on the Ach-P(LA-ClTMC)-10 film. All the results indicate that the integration of the acetylcholine analog at an appropriate fraction could be an effective strategy for optimizing the existing biodegradable polyesters for nerve regeneration applications. PMID:24998182

Xing, Dongming; Ma, Lie; Gao, Changyou

2014-10-01

156

Two new inorganic-organic hybrid single pendant hexadecavanadate derivatives with bifunctional electrocatalytic activities  

International Nuclear Information System (INIS)

Two new supramolecular assembly hexadecavanadate derivatives of H2[Cd(phen)3]2{[Cd(H2O)(phen)2](V16O38Cl)}.2.5H2O 1 (phen = 1,10'-phenanthroline) and H2[Cd(bipy)3][Cd(H2O)(bipy)2]{[Cd(H2O)(bipy)2](V16O38Cl)}.1.5H2O 2 (bipy 2,2'-bipyridine), have been prepared under mild hydrothermal conditions and structurally characterized by IR, XPS spectra, TG analyses and single-crystal X-ray diffraction. Compounds 1 and 2 are constructed from single pendant [CdL2] (L = phen, 1 and L = bipy, 2) modified hexadecavanadates. The hybrids 1 and 2 were used as solid bulk modifier to fabricate bulk-modified carbon paste electrodes (CPEs) (1-CPE and 2-CPE) by direct mixing. The electrochemical behaviors and electrocatalysis of 1-CPE and 2-CPE indicate bifunctional electrocatalytic activities toward both the oxidation and reduction of nitrite. Furthermore, their electrocatalytic activities toward the reduction of bromate and oxidation of ascorbic acid are also studied in 1 M H2SO4 aqueous solutions

157

Massacres, tueries, exécutions et meurtres de masse pendant la Révolution, quelles grilles d’analyse ?  

Directory of Open Access Journals (Sweden)

Full Text Available Alors que les violences commises pendant la Révolution française sont toujours d’actualité, les difficultés demeurent pour les appréhender et les qualifier, encore plus pour les inscrire dans des comparaisons avec des événements proches survenus dans d’autres lieux comme à d’autres époques. L’article examine les diverses perspectives dans lesquelles les massacres de la période révolutionnaire s’inscrivent depuis les premières désignations jusqu’aux modèles contemporains. Ainsi le recours aux catégories de « la guerre civile », des violences d’État, de l’état de guerre, enfin du sacré permet d’éclairer les massacres, meurtres, exécutions de la période révolutionnaire.The violences committed at the time of the French Revolution are always a stake nowadays. Great difficulties remain to explain and qualify them, more to inscribe them in comparisons with similar events in different places and times. This paper suggests the possibilities given by the perspectives of « civil war », State violence, state of war and the Sacred.

Jean-Clément Martin

2011-02-01

158

Investigations in the SNL SCOT loop of Dungeness 'B' pendant liner vibrations  

International Nuclear Information System (INIS)

Tests in the SCOT loop on production pendant liners have demonstrated that during normal reactor operation their response to flow or acoustic excitation is negligibly small and does not constitute a hazard. During on-power charge/ discharge operations, liner response increases when flow is directed downwards into the plug unit/liner annulus, and dynamic strain levels have been measured that when considered in conjunction with the residual stress would adequately explain the failure of a Marchwood Engineering Laboratory (MEL) prototype liner confirming the results of tests at MEL. Modal analysis showed the liner to be lightly damped and to have several readily excitable modes. Of these, only the 3rd, 4th and 5th ovalling modes occurring at 525, 925 and 1300 Hz respectively were excited to a significant level in flow tests. A number of modifications to liner design that were successful to some extent in attenuating response in SCOT were not acceptable for reactor use. Chamfering of the liner perforations which would have been an acceptable reactor modification did not, in the SCOT tests, prove to be as effective as had been indicated by air rig tests. Comparison of the SCOT results with available fatigue data leads to the conclusion that the unmodified production liners should survive for the life of the reactor, but margins are small. (U.K.)

159

Folding graft copolymer with pendant drug segments for co-delivery of anticancer drugs.  

Science.gov (United States)

A graft copolymer with pendant drug segments can fold into nanostructures in a protein folding-like manner. The graft copolymer is constructed by directly polymerizing ?-camptothecin-glutamate N-carboxyanhydride (Glu(CPT)-NCA) on multiple sites of poly(ethylene glycol) (PEG)-based main chain via the ring open polymerization (ROP). The "purely" conjugated anticancer agent camptothecin (CPT) is hydrophobic and serves as the principal driving force during the folding process. When exposed to water, the obtained copolymer, together with doxorubicin (Dox), another anticancer agent, can fold into monodispersed nanocarriers (with a diameter of around 50 nm) for dual-drug delivery. Equipped with a PEG shell, the nanocarriers displayed good stability and can be internalized by a variety of cancer cell lines via the lipid raft and clathrin-mediated endocytotic pathway without premature leakage, which showed a high synergetic activity of CPT and Dox toward various cancer cells. In vivo study validated that the nanocarriers exhibited strong accumulation in tumor sites and showed a prominent anticancer activity against the lung cancer xenograft mice model compared with free drugs. PMID:24875756

Tai, Wanyi; Mo, Ran; Lu, Yue; Jiang, Tianyue; Gu, Zhen

2014-08-01

160

Inorganic syntheses reagents for transition metal complex and organometallic syntheses  

CERN Document Server

The volumes in this continuing series provide a compilation of current techniques and ideas in inorganic synthetic chemistry. Includes inorganic polymer syntheses and preparation of important inorganic solids, syntheses used in the development of pharmacologically active inorganic compounds, small-molecule coordination complexes, and related compounds. Also contains valuable information on transition organometallic compounds including species with metal-metal cluster molecules. All syntheses presented here have been tested.

Angelici, Robert J

2009-01-01

 
 
 
 
161

X-Armed Bandits  

CERN Document Server

We consider a generalization of stochastic bandits where the set of arms, $\\cX$, is allowed to be a generic measurable space and the mean-payoff function is "locally Lipschitz" with respect to a dissimilarity function that is known to the decision maker. Under this condition we construct an arm selection policy, called HOO hierarchical optimistic optimization), with improved regret bounds compared to previous results for a large class of problems. In particular, our results imply that if $\\cX$ is the unit hypercube in a Euclidean space and the mean-payoff function has a finite number of global maxima around which the behavior of the function is locally H\\"older continuous with a known exponent, then the expected of HOO regret is bounded up to a logarithmic factor by $\\sqrt{n}$, i.e., the rate of growth of the regret is independent of the dimension of the space. We also prove the minimax optimality of our algorithm when the dissimilarity is a metric.

Bubeck, Sébastien; Stoltz, Gilles; Szepesvari, Csaba

2010-01-01

162

Phosphorus-nitrogen compounds: Part 28. Syntheses, structural characterizations, antimicrobial and cytotoxic activities, and DNA interactions of new phosphazenes bearing vanillinato and pendant ferrocenyl groups  

Science.gov (United States)

The gradually Cl replacement reactions of spirocyclic mono (1 and 2) and bisferrocenyl cyclotriphosphazenes (3-5) with the potassium salt of 4-hydroxy-3-methoxybenzaldehyde (potassium vanillinate) gave mono (1a-5a), geminal (gem-1b-5b), non-geminal (cis-1b, cis-5b and trans-2b-5b), tri (1c-5c) and tetra-substituted phosphazenes (1d-5d). Some phosphazenes have stereogenic P-center(s). The chirality of 4c was verified using chiral HPLC column. Electrochemical behaviors were influenced only by the number of ferrocene groups, but not the length of the amine chains and the substituent(s). The structures of the new phosphazenes were determined by FTIR, MS, 1H, 13C and 31P NMR, HSQC and HMBC spectral data. The solid-state structures of cis-1b and 4d were examined by single crystal X-ray diffraction techniques. The twelve phosphazene derivatives were screened for antimicrobial activity and the compounds 5a, cis-1b and 2c exhibited the highest antibacterial activity against G(+) and G(-) bacteria. In addition, it was found that overall gem-1b inhibited the growth of Mycobacterium tuberculosis. The compounds 1d, 2d and 4d were tested in HeLa cancer cell lines. Among these compounds, 2d had cytotoxic effect on HeLa cell in the first 48 h. Moreover, interactions between compounds 2a, gem-1b, gem-2b, cis-1b, 2c, 3c, 4c, 5c, 1d, 2d and 4d, and pBR322 plasmid DNA were investigated.

Tümer, Yasemin; Asmafiliz, Nuran; K?l?ç, Zeynel; Hökelek, Tuncer; Yasemin Koç, L.; Aç?k, Leyla; Yola, Mehmet Lütfi; Solak, Ali Osman; Öner, Ya?mur; Dündar, Devrim; Yavuz, Makbule

2013-10-01

163

Recovery of highly-purified rare earth elements using newly-synthesized chelating resins  

International Nuclear Information System (INIS)

The chromatographic separation of rare earth elements was studied using newly-synthesized chelating resins which have EDTA (ethylenediaminetetraacetic acid) and DTTA (diethylenetriaminetetraacetic acid) pendant groups. The chromatography using EDTA- and DTTA-chelating resins gave excellent separation results, while the IDA-chelating resin was not satisfactory. The DTTA-type resin was especially effective, allowing highly purified rare earth elements to be recovered. The separation efficiency of each resin was attributed mainly to the difference in its complexing capability among rare earth ions. Prior to experimentation, the chromatographic conditions were assessed and optimized by computer simulation based on newly introduced equations. The simulation results were effective in the case of Pr3+/Nd3+ for determining the experimental conditions. An analysis of the experimental results helped to elucidate the mechanism of the chromatographic separation while using the simulation results. (author)

164

49 CFR 234.223 - Gate arm.  

Science.gov (United States)

...Transportation 4 2010-10-01 2010-10-01 false Gate arm. 234.223 Section 234.223 Transportation...and Testing Maintenance Standards § 234.223 Gate arm. Each gate arm, when in the downward position, shall...

2010-10-01

165

Molecular modeling of the pendant chain in Nafion{reg_sign}  

Energy Technology Data Exchange (ETDEWEB)

Ion transport through perfluorosulfonic acid ionomers such as Nafion{reg_sign} is controlled by both the microstructure of the polymer and the charge and water distribution in the hydrated polymer. The authors present here the results of theoretical calculations on the side chain of Nafion{reg_sign}, establishing microscopic information for the modeling of water modeling of water modeling of water and proton transport in the membrane. Optimized geometries for the trifluoromethane sulfonic acid fragment (CF{sub 3}SO{sub 3}H), the di-trifluoromethane ether fragment (CF{sub 3}OCF{sub 3}), and the side chain (CF{sub 3}{single_bond}OCF{sub 2}CF(CF{sub 3})OCF{sub 2}CF{sub 2}SO{sub 3}H) were determined by means of both ab initio Hartree Fock theory with second order Moeller-Plesset electron correlation corrections, and density functional theory with Becke`s three parameter hybrid method. Several rotational potential energy surfaces were calculated to assess chain flexibility and proton accessibility. A probe water molecule was added to each of the fragments to characterize hydrophilic sites. These calculations confirmed that the sulfonic acid group is hydrophilic and the ethers are hydrophobic. Molecular dynamics simulations were then performed on the side chain to check the conditions required to stretch the pendant chain. Thermal averages of several structural parameters assessing the flexibility and stretch of the chain were computed from selected conformations produced in the simulation and these results indicate that although the sulfonate group is free to rotate, the chain stretches little. The construction of a potential energy surface for rotation about the second ether group suggests that the side chain exists in a folded or curled up conformation. A physical continuum dielectric solvent model was used to obtain free energies of electrostatic interaction of the fragments and the full chain with the solvent.

Paddison, S.J.; Zawodzinski, T.A.

1998-03-01

166

Hydrogen bonding and electron transfer between dimetal paddlewheel compounds containing pendant 2-pyridone functional groups.  

Science.gov (United States)

The compounds M2(TiPB)3(HDON) (TiPB = 2,4,6-triisopropylbenzoic acid; H2DON = 2,7-dihdroxy-1,8-napthyridine; M = Mo (1a) or W (1b)) and Mo2(TiPB)2(O2CCH2Cl)(HDON) (1c) which contain a pendant 2-pyridone functional group have been prepared. These compounds are capable of forming self-complementary hydrogen bonds, resulting in the formation of "dimers of dimers" ([1a-c]2) in CH2Cl2 solutions. Electrochemical studies reveal two successive one-electron redox processes for [1a-c]2 in CH2Cl2 solutions that correspond to successive oxidations of the dimetal core, indicating stabilization of the mixed-valence state. Only small changes in the value of Kc are observed upon changing the ancillary ligand or metal, implying that proton coupled mixed valency is responsible for the stabilization. Dimethylsulfoxide (DMSO) disrupts the hydrogen bonding interactions in these compounds, and a single oxidation process is observed in DMSO which shifts to lower potential as the number of HDON ligands increases. Further substitution of carboxylate ligands with HDON leads to the formation of Mo2(TiPB)2(HDON)2 (2) and Mo2(HDON)4 (3), which adopt trans-1,1 and cis-2,2 regioisomers in the solid-state. (1)H NMR spectroscopy indicates that there are at least two regioisomers present in solution for both compounds. The lowest energy transition in the electronic absorption spectra of these compounds corresponds to a M2-? ? HDON-?* transition. The electrochemical, spectroscopic and structural results were rationalized with the aid of density functional theory (DFT) calculations. PMID:23927688

Wilkinson, Luke A; McNeill, Laura; Scattergood, Paul A; Patmore, Nathan J

2013-08-19

167

Dinuclear rhenium complexes as redox-active pendants in a novel electrodeposited polycyclopentadithiophene material.  

Science.gov (United States)

The novel [Re2(?-H)(?-OOC-CPDT)(CO)6(?-3-Me-pydz)] complex (1; OOC-CPDT = 4H-cyclopenta[2,1-b:3,4-b']dithiophene-4-carboxylate, 3-Me-pydz = 3-methylpyridazine) has been prepared and characterized by single-crystal X-ray diffraction, density functional theory (DFT), and time-dependent DFT computations, UV-vis absorption and emission spectroscopy, and cyclic voltammetry (CV). The measured properties indicate the lack of electronic communication in the ground state between the CPDT and the rhenium diazine moieties. Oxidative electropolymerization of 1, achieved by repeated potential cycling (-0.4 to +1.0 V vs Fc(+)/Fc, in acetonitrile) with different supporting electrolytes, on different electrodes, afforded an electroactive and stable metallopolymer (poly-1). In situ measurements of the mass of the growing film (on a gold electrode, with an electrochemical quartz microbalance) confirmed the regularity of the polymerization process. The polymer exhibits two reversible oxidation peaks of the thiophene chain and a broad irreversible reduction peak (-1.4 V, quite close to that observed for the reduction of monomer 1), associated with a remarkably delayed sharp return peak, of comparable associated charge, appearing in close proximity (+0.3 V) to the first oxidation peak of the neutral polythiophene chain. This charge-trapping effect can be observed upon repeated cycles of p and n doping, and the negative charge is maintained even if the charged electrode is removed from the solution for many hours. Electrochemical impedance spectroscopy showed that the main CV oxidation peak corresponds to facile charge transfer, combined with very fast diffusion of both electrons and ions within the polymer. In summary, poly-1 provides a new example of a metallopolymer, in which the conductive properties of the ?-conjugated system are added to the redox behavior of the pendant-isolated complexes. PMID:25285663

Procopio, Elsa Quartapelle; Bonometti, Valentina; Panigati, Monica; Mercandelli, Pierluigi; Mussini, Patrizia R; Benincori, Tiziana; D'Alfonso, Giuseppe; Sannicolò, Francesco

2014-10-20

168

Polythiophene derivative comprising carbazoles as pendant groups for polymer solar cell applications  

International Nuclear Information System (INIS)

We have prepared a polythiophene copolymer (CzPh-PT) containing 9-position substituted carbazoles as bulky pendants and investigated its application in polymer solar cell (PSC). Electrochemical study presented that the onset oxidation potential positively shifted 0.47 eV for CzPh-PT in comparison with that of poly(3-hexyl thiophene). By incorporating the bulky substituent of CzPh-PT, the effective conjugation length can be curtailed, and consequently a lowered HOMO energy level (-5.38 eV) was acquired. This promises better air stability and a high open circuit voltage (Voc) for the PSC. Moreover, the optical properties of CzPh-PT reveal that the presence of ?-? interaction between carbazole units can enhance light harvesting ability in visible region, leading to a wide absorbance. PSC was fabricated based on an interpenetrating network of CzPh-PT as electron-sufficient polymer and [6,6]-phenyl C61 butyric acid methyl ester (PC61BM) as electron-deficient material. The PSC device based on the blend of CzPh-PT/PC61BM (w/w = 1:1) gave the best preliminary result with a Voc of 0.85 V, a short-circuit current of 1.57 mA/cm2, and a fill factor of 0.27, offering an overall power conversion efficiency of 0.36%. Our finding suggests that the polythiophene derivative comprising bulky steric groups as side chains is promising for PSC applications.

169

Anionic polymerization and polyhomologation: An ideal combination to synthesize polyethylene-based block copolymers  

A novel one-pot methodology combining anionic polymerization and polyhomologation, through a "bridge" molecule (BF3OEt 2), was developed for the synthesis of polyethylene (PE)-based block copolymers. The anionically synthesized macroanion reacts with the "bridge" molecule to afford a 3-arm star (trimacromolecular borane) which serves as an initiator for the polyhomologation. 2013 The Royal Society of Chemistry.

Zhang, H.

2013-08-07

170

ARM Lead Mentor Selection Process  

Energy Technology Data Exchange (ETDEWEB)

The ARM Climate Research Facility currently operates more than 300 instrument systems that provide ground-based observations of the atmospheric column. To keep ARM at the forefront of climate observations, the ARM infrastructure depends heavily on instrument scientists and engineers, also known as Instrument Mentors. Instrument Mentors must have an excellent understanding of in situ and remote-sensing instrumentation theory and operation and have comprehensive knowledge of critical scale-dependent atmospheric processes. They also possess the technical and analytical skills to develop new data retrievals that provide innovative approaches for creating research-quality data sets.

Sisterson, DL

2013-03-13

171

Liquid-vapour surface tension measurements of refractory metals by the pendant drop method under ultrahigh vacuum conditions  

International Nuclear Information System (INIS)

A careful implementation of the pendant drop technique for preparing the samples processed in an ultrahigh vacuum drop tube allows to measure accurately the liquid-vapor surface tension of a new set of refractory metals (Hf, V, Ti). It is shown that the result value disparity is essentially due to the complex action of the gases that are present in the drop volume. This study may also help to understand the significant disparities observed between the published values of this property. (authors). 12 refs., 1 fig., 2 tabs

172

Pierre Vidal-Naquet et le combat d'un intellectuel contre la torture pendant la guerre d'Algérie  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Min masteroppgave som har tittelen: ?Pierre Vidal-Naquet et le combat d?un intellectuel contre la torture pendant la guerre d?Algérie?, tar for seg den franske intellektuelle historikeren Pierre Vidal-Naquet et og hans engasjement mot bruken av tortur under Algerie krigen 1954-1962. Oppgaven er delt inn i tre deler. I den første delen redegjør jeg for metoden jeg bruker, videre presenterer jeg forhistorien til Algerie krigen og dens utvikling. I del 1 finnes også en generell beskri...

Traaholt, Stine

2006-01-01

173

Geologic map of southwestern Sequoia National Park and vicinity, Tulare County, California, including the Mineral King metamorphic pendant  

Science.gov (United States)

From the late 1940s to the early 1990s, scientists of the U.S. Geological Survey (USGS) mapped the geology of most of Sequoia and Kings Canyon National Parks, California, and published the results as a series of 15-minute (1:62,500 scale) Geologic Quadrangles. The southwest corner of Sequoia National Park, encompassing the Mineral King and eastern edge of the Kaweah 15-minute topographic quadrangles, however, remained unfinished. At the request of the National Park Service's Geologic Resources Division (NPS-GRD), the USGS has mapped the geology of that area using 7.5-minute (1:24,000 scale) topographic bases and high-resolution ortho-imagery. With partial support from NPS-GRD, the major plutons in the map area were dated by the U-Pb zircon method with the Stanford-USGS SHRIMP-RG ion microprobe. Highlights include: (1) Identification of the Early Cretaceous volcano-plutonic suite of Mineral King (informally named), consisting of three deformed granodiorite plutons and the major metarhyolite tuffs of the Mineral King metamorphic pendant. Members of the suite erupted or intruded at 130-140 Ma (pluton ages: this study; rhyolite ages: lower-intercept concordia from zircon results of Busby-Spera, 1983, Princeton Ph.D. thesis, and from Klemetti et al., 2011, AGU abstract) during the pause of igneous activity between emplacement of the Jurassic and Cretaceous Sierran batholiths. (2) Some of the deformation of the Mineral King metamorphic pendant is demonstrably Cretaceous, with evidence including map-scale folding of Early Cretaceous metarhyolite tuff, and an isoclinally folded aplite dike dated at 98 Ma, concurrent with the large 98-Ma granodiorite of Castle Creek that intruded the Mineral King pendant on the west. (3) A 21-km-long magmatic synform within the 99-100 Ma granite of Coyote Pass that is defined both by inward-dipping mafic inclusions (enclaves) and by sporadic, cm-thick, sharply defined mineral layering. The west margin of the granite of Coyote Pass overlies parts of the adjacent Mineral King pendant, and the pluton probably had an upward-flaring shape, with synformal layering and foliation resulting from compaction and mineral deposition (or flow sorting) at the floor of an elongate, melt-rich magma lens. The NPS-GRD has digitized the published USGS geologic quadrangles for Sequoia and Kings Canyon National Parks, and a goal is to jointly release a geologic map of the combined Parks region.

Sisson, T. W.; Moore, J. G.

2012-12-01

174

ARM Standards Policy Committee Report  

Energy Technology Data Exchange (ETDEWEB)

Data and metadata standards promote the consistent recording of information and are necessary to ensure the stability and high quality of Atmospheric Radiation Measurement (ARM) Climate Research Facility data products for scientific users. Standards also enable automated routines to be developed to examine data, which leads to more efficient operations and assessment of data quality. Although ARM Infrastructure agrees on the utility of data and metadata standards, there is significant confusion over the existing standards and the process for allowing the release of new data products with exceptions to the standards. The ARM Standards Policy Committee was initiated in March 2012 to develop a set of policies and best practices for ARM data and metadata standards.

Cialella, A; Jensen, M; Koontz, A; McFarlane, S; McCoy, R; Monroe, J; Palanisamy, G; Perez, R; Sivaraman, C

2012-09-19

175

Farming with an Arm Amputation  

Science.gov (United States)

Farming with an Arm Amputation Farmers with upper-extremity amputations are at risk of secondary injuries because they may (a) have decreased padding or scar tissue around a stump that may make it vulnerable to damage from bumping or ...

176

Experimental validation of dual/modified dual arm locking for LISA  

International Nuclear Information System (INIS)

The laser frequency stabilization subsystem is one of the most significant parts within the interferometric measurement system of LISA. Arm locking as a proposed frequency stabilization technique synthesizes an adequately filtered linear combination of the interferometry signals as a frequency reference. Until now all the benchtop experiments on arm locking verified only the basic single arm locking configuration with unrealistic short signal travel times. At the University of Florida we developed the hardware-based University of Florida LISA Interferometer Simulator (UFLIS) to study and verify laser frequency noise reduction and suppression techniques under realistic LISA-like conditions. These conditions include the Doppler shifts between the spacecraft, LISA-like signal travel times, realistic laser frequency and timing noise. In this paper we will report about preliminary experiments on advanced arm locking schemes including dual arm locking and modified dual arm locking with realistic 33 s light travel times. In our experiments the implementation of a dual/modified dual arm locking sensor and controller is realized using several digital signal processing boards. We demonstrated the closed-loop stability of arm locking setup and measured the noise suppression in these experiments.

177

Design, construction and application of a fully automated equimolar peptide mixture synthesizer.  

Science.gov (United States)

A fully automated peptide synthesizer has been constructed that is capable of the synthesis of equimolar peptide mixtures and the simultaneous synthesis of 36 individual peptides. The synthesizer was constructed from a workstation of our own design utilizing a Zymark robot arm. A Macintosh II computer coordinates the movements of the robotic arm, the switching of over 40 solenoid valves and the monitoring of sensors in the workstation. The robot hands are used to deliver solvents from pressurized spigot lines and to pipet amino acid solutions from reservoirs to an array of reaction vessels. Liquid dispensing, reagent mixing and solvent removal are controlled from a multifunction I/O board in the computer. The design features of the synthesizer are presented, as well as the characterization of multiple individual peptides, a simple mixture of 19 components, and a complex mixture of 15,625 components. PMID:1286933

Zuckermann, R N; Kerr, J M; Siani, M A; Banville, S C

1992-12-01

178

Test-Retest Reliability of a Pendant-Worn Sensor Device in Measuring Chair Rise Performance in Older Persons  

Directory of Open Access Journals (Sweden)

Full Text Available Chair rise performance is incorporated in clinical assessments to indicate fall risk status in older persons. This study investigated the test-retest reliability of a pendant-sensor-based assessment of chair rise performance. Forty-one older persons (28 females, 13 males, age: 72–94 were assessed in two sessions with 3 to 8 days in between. Repeated chair rise transfers were measured after different instructions. Relative and absolute test-retest reliability of chair rise measurements in individual tests and average over all tests were evaluated by means of intra-class correlation coefficients (ICCs and standard error of measurement (SEM as a percentage of the measurement mean. Systematic bias between the measurements in test and retest was examined with paired t-tests. Heteroscedasticity of the measurements was visually checked with Bland-Altman plots. In the different test conditions, the ICCs ranged between 0.63 and 0.93, and the SEM% ranged between 5.7% and 21.2%. The relative and absolute reliability of the average over all tests were ICC = 0.86 and SEM% = 9.5% for transfer duration, ICC = 0.93 and SEM% = 9.2% for maximum vertical acceleration, and ICC = 0.89 and SEM% = 10.0% for peak power. The results over all tests indicated that a fall risk assessment application based on pendant-worn-sensor measured chair rise performance in daily life might be feasible.

Wei Zhang

2014-05-01

179

Sensibilité des œufs de truite arc-en-ciel aux chocs mécaniques pendant la phase de durcissement  

Directory of Open Access Journals (Sweden)

Full Text Available Des œufs de Truite arc-en-ciel en provenance de plusieurs femelles ont été transférés en eau douce après insémination et soumis à une agitation mécanique pendant une heure. Généralement on observe après 30 mn d'agitation une diminution du pourcentage d'œufs embryonnés qui est significative (P < 0,001 et P < 0,05. Cependant dans le cas d'une femelle la diminution n'était pas significative (fig. 1. Si l'agitation est appliquée seulement entre la 30e et la 60e minute après le transfert en eau douce, il n'y a pas de diminution du pourcentage d'œufs embryonnés (fig. 3. Il n'y a donc pas de phases plus sensibles que d'autres ; la durée totale d'agitation étant le facteur le plus important. La manipulation des œufs pendant une heure après leur transfert en eau douce apparaît au moins dans certains cas préjudiciable au développement embryonnaire et doit donc être évitée

BILLARD R.

1976-10-01

180

Oxidative synthesis of a novel polyphenol having pendant Schiff base group: Synthesis, characterization, non-isothermal decomposition kinetics  

Energy Technology Data Exchange (ETDEWEB)

Research highlights: {yields} In this study, the synthesis and thermal characterization of a new functional polyphenol are reported. {yields} Non-isothermal methods were used to evaluate the thermal decomposition kinetics of resulting polymer. {yields} Thermal decomposition of polymer follows a diffusion type kinetic model. {yields} It is noted that this kinetic model is quite rare in polymer degradation studies. - Abstract: In here, the facile synthesis and thermal characterization of a novel polyphenol containing Schiff base pendant group, poly(4-{l_brace}[(4-hydroxyphenyl)imino]methyl{r_brace}benzene-1,2,3-triol) [PHPIMB], are reported. UV-vis, FT-IR, {sup 1}H NMR, {sup 13}C NMR, GPC, TG/DTG-DTA, CV (cyclic voltammetry) and solid state conductivity measurements were utilized to characterize the obtained monomer and polymer. The spectral analyses results showed that PHPIMB was composed of polyphenol main chains containing Schiff base pendant side groups. Thermal properties of the polymer were investigated by thermogravimetric analyses under a nitrogen atmosphere. Five methods were used to study the thermal decomposition of PHPIMB at different heating rate and the results obtained by using all the kinetic methods were compared with each other. The thermal decomposition of PHPIMB was found to be a simple process composed of three stages. These investigated methods were those of Flynn-Wall-Ozawa (FWO), Tang, Kissinger-Akahira-Sunose (KAS), Friedman and Kissinger methods.

Dilek, Deniz [Faculty of Education, Secondary Science and Mathematics Education, Canakkale Onsekiz Mart University, 17100 Canakkale (Turkey); Dogan, Fatih, E-mail: fatihdogan@comu.edu.tr [Faculty of Education, Secondary Science and Mathematics Education, Canakkale Onsekiz Mart University, 17100 Canakkale (Turkey); Bilici, Ali, E-mail: alibilici66@hotmail.com [Control Laboratory of Agricultural and Forestry Ministry, 34153 Istanbul (Turkey); Kaya, Ismet [Department of Chemistry, Faculty of Science and Arts, Canakkale Onsekiz Mart University, Canakkale (Turkey)

2011-05-10

 
 
 
 
181

RAMESES publication standards: realist syntheses  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background There is growing interest in realist synthesis as an alternative systematic review method. This approach offers the potential to expand the knowledge base in policy-relevant areas - for example, by explaining the success, failure or mixed fortunes of complex interventions. No previous publication standards exist for reporting realist syntheses. This standard was developed as part of the RAMESES (Realist And MEta-narrative Evidence Syntheses: Evolving Standards project. The project's aim is to produce preliminary publication standards for realist systematic reviews. Methods We (a collated and summarized existing literature on the principles of good practice in realist syntheses; (b considered the extent to which these principles had been followed by published syntheses, thereby identifying how rigor may be lost and how existing methods could be improved; (c used a three-round online Delphi method with an interdisciplinary panel of national and international experts in evidence synthesis, realist research, policy and/or publishing to produce and iteratively refine a draft set of methodological steps and publication standards; (d provided real-time support to ongoing realist syntheses and the open-access RAMESES online discussion list so as to capture problems and questions as they arose; and (e synthesized expert input, evidence syntheses and real-time problem analysis into a definitive set of standards. Results We identified 35 published realist syntheses, provided real-time support to 9 on-going syntheses and captured questions raised in the RAMESES discussion list. Through analysis and discussion within the project team, we summarized the published literature and common questions and challenges into briefing materials for the Delphi panel, comprising 37 members. Within three rounds this panel had reached consensus on 19 key publication standards, with an overall response rate of 91%. Conclusion This project used multiple sources to develop and draw together evidence and expertise in realist synthesis. For each item we have included an explanation for why it is important and guidance on how it might be reported. Realist synthesis is a relatively new method for evidence synthesis and as experience and methodological developments occur, we anticipate that these standards will evolve to reflect further methodological developments. We hope that these standards will act as a resource that will contribute to improving the reporting of realist syntheses. To encourage dissemination of the RAMESES publication standards, this article is co-published in the Journal of Advanced Nursing and is freely accessible on Wiley Online Library (http://www.wileyonlinelibrary.com/journal/jan. Please see related article http://www.biomedcentral.com/1741-7015/11/20 and http://www.biomedcentral.com/1741-7015/11/22

Wong Geoff

2013-01-01

182

Synthesis and Characterization of Novel Soluble Aromatic Polyesters with Pendant Cyano Groups  

Digital Repository Infrastructure Vision for European Research (DRIVER)

2, 6-Bis (4-carboxyphenoxy) benzonitrile was first synthesized by condensation of 2, 6-difluorobenzonitrile with p-Hydroxybenzoic acid in the presence of KOH and DMSO. And then the reaction of 2, 6-bis (4-carboxyphenoxy) benzonitrile with sulfur oxychloride yieded 2, 6-bis (4-chloroformylphenoxy) benzonitril...

Yikai Yu; Mingzhong Cai; Tao Wang

2009-01-01

183

A modular synthesis of dithiocarbamate pendant unnatural a-amino acids  

Science.gov (United States)

Unnatural a-amino acids containing dithiocarbamate side chains were synthesized by a one-pot reaction of in-situ generated dithiocarbamate anions with sulfamidates. A wide range of these anions participated in the highly regio- and stereo-selective ring opening of sulfamidates to...

184

Design of Robotic Arm Control System Mimics Human Arm Motion  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a control system to make the robotic hand mimic human hand motion in real time and offline mode. The human hand tracking system is a wearable sensing arm (potentiometers used to determine the position in space and to sense the grasping task of human hand. The maskable sensing arm was designed with same geometrical arrangement of robotic hand that needs to be controlled. The control software of a robot was implemented using Visual Basic and supported with graphical user interface (GUI. The control algorithm depends on joint to joint mapping method to match between the motions at each joint of portable sensing arm with corresponding joint of a robot in order to make the robot mimic the motion.

A. Salam Al-Ammri

2013-01-01

185

Stellar spiral arms in smooth-armed galaxies  

International Nuclear Information System (INIS)

Deep multicolor surface photometry has been obtained for three extreme examples of smooth-armed spirals, galaxies with a global spiral pattern but with little or no interstellar gas, dust, or recent star formation: NGC 7743, NGC 495 and NGC 718. The results suggest that smooth-armed spirals may be transient bar-driven density waves (with a lifetime of about 1 Gyr) in galaxies which spend most of their lifetimes as much smoother SB0 or SBa galaxies, unless an efficient mechanism for transferring angular momentum from the bar is present. 21 references

186

Pseudotachylite Bearing Cretaceous Fault in the Saddlebag Lake Pendant, Central Sierra Nevada, CA  

Science.gov (United States)

Over the past several years the undergraduate researchers and mentors in the University of Southern California’s Undergraduate Team Research program has mapped the northern continuation of the Gem Lake shear zone from Gem Lake to Virginia Canyon near the north end of the Saddlebag pendant. In the center of this dominantly dextral, ductile shear zone we now recognize a pseudotachylite bearing brittle fault that often juxtaposes Triassic metavolcanics to the east of the fault with a Jurassic metasedimentary package to the west of the fault. Kinematic indicators such as slickenlines, steps, and offset dikes found within the brittle fault zone also suggest dextral oblique motion, similar to the motion of the ductile shear zone. The brittle fault dips steeply and strikes N-NW with the fault zone width varying from narrow (sub m scale) to a 100-200 m wide fracture zone as seen in the Sawmill area. Jurrasic metasediments (> 177Ma) and Cretaceous metavolcanics (110-95Ma) lie to the West of the fault and Triassic metavolcanics (219Ma) lie to the East of the fault in the Virginia Canyon, Saddlebag Lake, and Sawmill areas. The absence of ~45 million years of Jurassic metavolcanics along the contact of the fault in each area, suggests tectonic removal of the sequence. Pseudotachylite, quartz vein rich breccias, gouge, fault scarps, and truncated Cathedral Peak dikes (~88 Ma) originating from the Tuolumne Batholith (TB), are common features associated with the brittle fault. The truncated, 88 Ma Cathedral Peak dikes plus nearby biotite cooling ages of 82 Ma indicate that displacement on the brittle fault continued well after TB emplacement and cooling and likely continued after ~80 Ma. The pseudotachylite suggests earthquakes occurred on the brittle fault during the Cretaceous. Movement also occurred along the fault at fairly shallow depths as indicated by the presence of vugs, or cavities with free euhedral crystal growth, within the quartz vein breccias. In the Sawmill Canyon area, located immediately southwest of Saddlebag Lake, the fault zone widens and is rich with evidence of brittle faulting including the quartz vein breccias similar to other study areas and localized pseudotachylite veins and breccias with angular rock fragments varying from 4 cm in size. The fault branches off into several different strands within this zone, each associated with the quartz breccias and pseudotachylite common in the area. Outcrop scale kink bands found along some of the fault strands, suggesting late brittle faulting with the decrease of regional strain. Brittle faulting in the Sawmill area may be further complicated by large-scale boudinage associated with the faulting in the area. Some of the contacts in this area identified as fault strands may in part be large, fluid-filled cracks associated with bending (tension due to scar folding?) during boudinage of the metasedimentary package and nearby margin of the Tuolumne batholith in the area.

Whitesides, A. S.; Cao, W.; Paterson, S. R.

2010-12-01

187

Welcome to the U. S. arms superstore  

Energy Technology Data Exchange (ETDEWEB)

After the 1991 Gulf War, the [open quotes]Big Five[close quotes]--the United States, France, Britain, the Soviet Union, and China--initiated talks on limiting the flow of arms to the Middle East and the United Nations established an arms register as a way to promote a more open international dialogue concerning the problem of conventional arms proliferation. Two and a half years later, the promises about arms controls have been forgotten in favor of a policy to sell arms to any nation possessing sufficient cash to purchase them. The promises to curb the weapons trade may have been forgotten because of the new dynamics that are driving the arms trade in the post-Cold War era. This article seeks to define these dynamics and to suggest means of getting the arms control process back on track. The rationale behind the commercialization of arms and means of combatting the arms exportation problem are emphasized. 18 refs.

Hartung, W.D. (International Arms Trade, New York, NY (United States))

1993-09-01

188

La evolución de la relación salarial durante la post convertibilidad L’évolution du rapport salarial pendant la post-convertibilité The evolution of the labor-wage nexus during the post-convertibility phase  

Directory of Open Access Journals (Sweden)

Full Text Available Este capítulo constituye una síntesis de trabajos realizados conjuntamente con Robert Boyer durante la década pasada y tiene como objetivo mostrar los cambios y la evolución de la relación salarial durante el periodo de la post-convertibilidad, es decir desde 2002 hasta fines de 2011, así como las principales restricciones que debe enfrentar el nuevo modo de desarrollo desde la crisis de los subprimes, que se manifiestan con fuerza desde el inicio del Segundo Mandato de la Dra. Cristina Fernández de Kirchner.Ce chapitre est une synthèse des travaux réalisés pendant la décennie dernière. Il analyse les changements du rapport salarial après l'abandon de la convertibilité, c´est-à-dire depuis 2002 et jusqu´à la fin de 2011. Il explicite ensuite les principales contraintes qui s'imposent au nouveau mode de développement depuis la crise des subprimes et limitent sa viabilité. Ces tensions se manifestent avec force dès le début du deuxième mandat de la présidente Cristina Fernández de Kirchner.This contribution synthesizes a decade of research. It analyses the dynamics of the wage-labor nexus after the convertibility period, i.e. from 2002 until the end of 2011. It also scrutinizes the most salient constraints arising in the development mode after the subprime crisis that limit its viability. These problems are becoming more obvious since the beginning of President Cristina Fernández de Kirchner second term.

Julio César Neffa

2012-04-01

189

Corrections to the article "The metric dimension of graph with pendant edges" [Journal of Combinatorial Mathematics and Combinatorial Computing, 65 (2008) 139--145  

CERN Document Server

We show that the principal results of the article "The metric dimension of graph with pendant edges" [Journal of Combinatorial Mathematics and Combinatorial Computing, 65 (2008) 139--145] do not hold. In this paper we correct the results and we solve two open problems described in the above mentioned paper.

Kuziak, D; Yero, I G

2010-01-01

190

Nuclear arms: ethics, strategy, politics  

Energy Technology Data Exchange (ETDEWEB)

The range of debate over strategy and arms control today is broader than it was in the late 1950s and early 1960s. In part this is because the early 1980s debate has involved questioning of the fundamental notion of deterrence - by no less than the American Catholic bishops. Today's debate has also seen a national nuclear freeze campaign that, although its congressional supporters have held firmly to a bilateral approach, was tilted perceptibly towards unilateralism by noncongressional leaders at their national conference in February 1983. In one way or another the authors wrestle with different aspects of one central question: could the beginning steps for any consensus be possible, in today's climate, on strategic issues. Ethical issues are addressed in the first 3 papers: Charles Krauthammer, On Nuclear Morality; Patrick Glynn, The Moral Case for the Arms Buildup; and Michael Quinlarc, Thinking Deterrence Through. Three chapters on strategic considerations include: Brent Snowcroft, Understanding the US Strategic Arsenal; William J. Perry, Technological Prospects for US Strategic Forces; and Richard Burt, The Strategic and Political Lessons of INF. Arms control and politics is treated in chapters by: Walter B. Slocombe, Arms Control: Prospects; and Colin S. Gray, Arms Control: Problems. The nonnuclear dimensions of strategy are discussed in chapters by Amory B. and L. Hunter Lovins, Reducing Vulnerability - The Energy Jugular; and Robert Kupperman, Vulnerable America. The chapters on space and defense are: Hans Mark, Arms Control and Space Technology; and Newt Gingrich and John Madison, Space and National Defense. The concluding chapters are by Sen. Sam Nunn, The Need to Reshape Military Stategy; and the editor, R. James Woolsey, The Politics of Vulnerability, 1980-1983.

Woolsey, R.J. (ed.)

1984-01-01

191

Conventional arms transfers: Exporting security or arming adversaries  

Energy Technology Data Exchange (ETDEWEB)

This study examines the dichotomy in the U.S. response to conventional and unconventional arms proliferation. With the end of the cold war, however, this has begun to change. While the spread of NBC munitions continues to be seen as an especially significant peril, many policymakers now view conventional arms transfers as a similar problem, with a comparable requirement for international controls. But a consistent policy and strategy has been difficult to develop because of competing pressures and demands: on one hand, there is a pressure to follow through on pledges to establish international controls on conventional arms traffic; on the other, is pressure to preserve long-standing military relationships with friendly foreign governments. The author maintains that the United States cannot pursue both objectives and expect to accomplish its stated policy goals of regional stability in the world where loyalties and alliances are breaking down and in which every nation is scrambling to advance its own national interests. He concludes that in today's uncertain and chaotic world, it is safer to view most arms transfers as a potential proliferation risk rather than as an assured asset for U.S. national security.

Klare, M.T.

1992-03-19

192

Discrete synthesizer of time intervals  

International Nuclear Information System (INIS)

The salient features and the operating principle of a discrete synthesizer of time intervals are described. The underlying principle of the device is the regenerative division of frequency of a high-stability UHF-oscillation. The synthesis of a discrete time scale is based on the two-scale principle: shaping of crude and exact time scales. The time interval synthesizer consists of two functional units. One of them is responsible for the shaping of intervals of the crude time scale and the other, of the exact time scale. Each of the units contains a delayed feedback generator, a circuit for selecting a pulse from the reference series of the above generator, a reset shaper, and shapers bringing the circuit back to the initial state. The generators of both units are synchronized in a timing unit which is a hybrid circuit of a UHF-tract and a threshold tunnel-diode regenerative element. When used as a timer of high-stability UHF-signals with a frequency of 1GHsub(Z) and a relative frequency instability of 1x10-9, the discrete time-interval synthesizer has the following parameters: the synthesized intervals, 20 to 1,000 nsec.; the discreteness of the rearrangement step, 1 nsec.; the uncertainty in setting the shaped interval relative to the starting pulse, about 80 psec.; and the relative instability of the interval, 1x10-9

193

Method of synthesizing pyrite nanocrystals  

Science.gov (United States)

A method of synthesizing pyrite nanocrystals is disclosed which in one embodiment includes forming a solution of iron (III) diethyl dithiophosphate and tetra-alkyl-ammonium halide in water. The solution is heated under pressure. Pyrite nanocrystal particles are then recovered from the solution.

Wadia, Cyrus; Wu, Yue

2013-04-23

194

Synthesis and reactivity of molybdenum and tungsten bis(dinitrogen) complexes supported by diphosphine chelates containing pendant amines  

Energy Technology Data Exchange (ETDEWEB)

In this study, we report the synthesis and characterization of molybdenum bis(dinitrogen) complexes supported by two PNP diphosphine ligands, Mo(N{sub 2}){sub 2}(PNP){sub 2}; PNP = [(R{sub 2}PCH{sub 2}){sub 2}N(R'), R = Et (ethyl), Ph (phenyl); R'= Me (methyl), Bn (benzyl)], and a series of tungsten bis(dinitrogen) complexes containing one or two PNP ligands, W(N{sub 2}){sub 2}(dppe)(PNP) and W(N{sub 2}){sub 2}(PNP){sub 2}, respectively, and the analogues complexes without pendant amines for comparison. These Mo- and W-N{sub 2} complexes were characterized by NMR, IR, spectroscopy, cyclic voltammetry and structurally characterized by X-ray crystallography. In addition, reactivity of the complexes with CO is described.

Weiss, Charles J.; Groves, Amy N.; Mock, Michael T.; Dougherty, William G.; Kassel, W. S.; Helm, Monte L.; DuBois, Daniel L.; Bullock, R. Morris

2012-04-30

195

HABITAT DE LA TRUITE COMMUNE (SALMO TRUTTA L. PENDANT LA PÉRIODE JUVÉNILE EN RUISSEAU : PRÉFÉRENCES, MOUVEMENTS, VARIATIONS JOURNALIÈRES ET SAISONNIÈRES.  

Directory of Open Access Journals (Sweden)

Full Text Available Cet article synthétise les résultats de travaux récents sur l’habitat de la truite commune pendant sa période juvénile en ruisseau. Par des approches in situ (affluents du Scorff, Bretagne et en milieu expérimental, les variations temporelles d’utilisation de l’habitat ont ét? étudiées, ainsi que l’influence de certains facteurs abiotiques (vitesse de courant, profondeur, granulométrie, abris et biotiques (prédation, compétition intraspécifique sur les choix d’habitat de l’individu. A l’aide de la bibliographie sur le sujet, nous proposons un bilan des changements journaliers et saisonniers d’habitat du juvénile en ruisseau, depuis l’émergence jusqu’à la première reproduction. En matière de protection des milieux, l’accent est mis sur l’importance de la diversité des habitats disponibles dans les affluents où se reproduit l’espèce.

ROUSSEL J. M.

2002-04-01

196

Nommer le conflit. Le cas de l’Alsace pendant son annexion de fait au Troisième Reich, 1940-1945  

Directory of Open Access Journals (Sweden)

Full Text Available L’étude des comportements et opinions de la population en Alsace entre 1940 et 1945 fait appel à la nécessité de nommer une conflictualité parfois floue, ambivalente et qui évolue au cours de la période. Il convient de s’interroger sur l’adaptation des outils de définition des comportements développés en France et en Allemagne pour la situation alsacienne pendant l’annexion de fait de son territoire.   Alsace 1940-1945, oppositions au nazisme, comportements collectifsDie Erforschung des Verhaltens und der Meinung der Bevölkerung im Elsass zwischen 1940-1945 bringt die Notwendigkeit mit sich, eine zuweilen undurchsichtige, zweideutige Konfliktträchtigkeit zu benennen, die sich im Zeitraum der Annektierung zudem entwickelte. Die methodischen Werkzeuge zur Definition kollektiven Verhaltens, die in Frankreich und Deutschland für diesen elsässischen Fall entwickelt wurden, müssen hierbei angepasst werden.

Anne-Ségolène Verneret

2011-12-01

197

Hydrogen bonding or transient coordination of pendant group: cause for liability in ligand substitution reaction of aminopolycarboxylatoruthenium (III) complexes  

International Nuclear Information System (INIS)

The rate of substitution of water molecule in [LRuIII(H2O)] complexes [L=ethylenediaminetetraacetate (EDTA) anion and N-hydroxyethylethylenediaminetriacetate (HEDTRA) anion] with Cl- ion has been studied spectrophotometrically in aqueous medium at 30degC. The rates of substitutions of Cl- in [LRuCl] with thiocyanate (SCN-) have also been studied as a function of SCN- concentration in the temperature range 30-50degC. In both the cases, ruthenium(III)-EDTA is found to be more reactive than the corresponding HEDTRA complex. Activation parameters ?Hsup(?) and ?Ssup(?) for the substitution of [LRuIIICl]-complexes with SCN- are determined and a suitable mechanism is proposed. The reactivity of [LRuIIICl]- towards SCN- substitution is discussed in terms of the transient coordination of the uncoordinated - COOH or -CH2 - OH pendant group which assist in the elimination of leaving group and ligation of substituting nucleophiles. (author). 12 refs., 2 tabs

198

Computing Free Energy Landscapes: Application to Ni-based Electrocatalysts with Pendant Amines for H2 Production and Oxidation  

Energy Technology Data Exchange (ETDEWEB)

A general strategy is reported for computational exploration of catalytic pathways of molecular catalysts. Our results are based on a set of linear free energy relationships derived from extensive electronic structure calculations that permit predicting the thermodynamics of intermediates, with accuracy comparable to experimental data. The approach is exemplified with the catalytic oxidation and production of H2 by [Ni(diphosphine)2]2+ electrocatalysts with pendant amines incorporated in the second coordination sphere of the metal center. The analysis focuses upon prediction of thermodynamic properties including reduction potentials, hydride donor abilities, and pKa values of both the protonated Ni center and pendant amine. It is shown that all of these chemical properties can be estimated from the knowledge of only the two redox potentials for the Ni(II)/Ni(I) and Ni(I)/Ni(0) couples of the non-protonated complex, and the pKa of the parent primary aminium ion. These three quantities are easily accessible either experimentally or theoretically. The proposed correlations reveal intimate details about the nature of the catalytic mechanism and its dependence on chemical structure and thermodynamic conditions such as applied external voltage and species concentration. This computational methodology is applied to exploration of possible catalytic pathways, identifying low and high-energy intermediates and, consequently, possibly avoiding bottlenecks associated with undesirable intermediates in the catalytic reactions. We discuss how to optimize some of the critical reaction steps in order to favor catalytically more efficient intermediates. The results of this study highlight the substantial interplay between the various parameters characterizing the catalytic activity, and form the basis needed to optimize the performance of this class of catalysts.

Chen, Shentan; Ho, Ming-Hsun; Bullock, R. Morris; DuBois, Daniel L.; Dupuis, Michel; Rousseau, Roger J.; Raugei, Simone

2014-01-03

199

Introduction of bridging and pendant organic groups into mesoporous alumina materials.  

Science.gov (United States)

Incorporation of organic functionalities into soft-templated mesoporous alumina was performed via organosilane-assisted evaporation induced self-assembly using aluminum alkoxide precursors and block copolymer templates. This strategy permits one to obtain mesoporous alumina-based materials with tailorable adsorption, surface and structural properties. Isocyanurate, ethane, mercaptopropyl, and ureidopropyl-functionalized mesoporous alumina materials were synthesized with relatively high surface area and large pore volume with uniform and wormhole-like mesopores. The presence of organosilyl groups within these hybrid materials was confirmed by IR or Raman spectroscopy and their concentration was determined by elemental analysis. PMID:21988174

Grant, Stacy M; Woods, Stephan M; Gericke, Arne; Jaroniec, Mietek

2011-11-01

200

Nuclear physicist, arms control advocate  

CERN Multimedia

Victor F. Weisskopf, a nuclear physicist who worked on the Manhattan Project to build the first atomic bomb in World War II and later became an ardent advocate of arms control, died Monday at his home in Newton, MA, USA. He was 93 (1 page).

Chang, K

2002-01-01

 
 
 
 
201

X-Band PLL Synthesizer  

Directory of Open Access Journals (Sweden)

Full Text Available This paper deals with design and realization of a PLL synthesizer for the microwave X−band. The synthesizer is intended for use as a local oscillator in a K−band downconverter. The design goal was to achieve very low phase noise and spurious free signal with a sufficient power level. For that purpose a low phase noise MMIC VCO was used in phase locked loop. The PLL works at half the output frequency, therefore there is a frequency doubler at the output of the PLL. The output signal from the frequency doubler is filtered by a band-pass filter and finally amplified by a single stage amplifier.

P. Kutin

2006-04-01

202

Production of a synthesized plasma  

International Nuclear Information System (INIS)

Neutralization of helium ion beam extracted from a stationarily operated duoplasmatron is studied. It was confirmed that the neutralization of ion space charge occurred mainly at the deceleration stage of the einzel lens, not in the downstream of the neutralizer. The magnetic field and arc current in the duoplasmatron affected substantially the beam divergence. The energy spectrum of the extracted ions was measured with an energy analyzing system consisting of a pre-decelerator and an electrostatic energy analyzer with 900 deflection. The energy spectrum of ions in the synthesized plasma was essentially defined by the operating conditions of the ion source; gas pressure, magnetic field and arc current in the arc discharge. A small difference between the space potential and the potential of the emitter changed the characteristics of the synthesized plasma. (auth.)

203

Performance of arm locking in LISA  

Science.gov (United States)

For the Laser Interferometer Space Antenna (LISA) to reach its design sensitivity, the coupling of the free-running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. In this paper we detail an implementation of arm locking. We investigate orbital effects (changing arm lengths and Doppler frequencies), the impact of errors in the Doppler knowledge that can cause pulling of the laser frequency, and the noise limit of arm locking. Laser frequency pulling is examined in two regimes: at lock acquisition and in steady state. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultrastable oscillator (clock) noise, spacecraft motion, and shot noise. We find that clock noise and spacecraft motion limit the performance of dual arm locking in the LISA science band. Studying these issues reveals that although dual arm locking [A. Sutton and D. A. Shaddock, Phys. Rev. DPRVDAQ1550-7998 78, 082001 (2008)10.1103/PhysRevD.78.082001] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a modification to the dual arm-locking sensor, a hybrid of common and dual arm-locking sensors. This modified dual arm-locking sensor has the laser frequency pulling characteristics and low-frequency noise coupling of common arm locking, but retains the control system advantages of dual arm locking. We present a detailed design of an arm-locking controller and perform an analysis of the expected performance when used with and without laser prestabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. With a time-delay error of 3 ns (equivalent of 1 m interspacecraft ranging error), time-delay interferometry (TDI) is capable of suppressing 300Hz/Hz of laser frequency noise to the required level. We show that if no interspacecraft laser links fail, arm locking alone surpasses this noise performance for the entire mission. If one interspacecraft laser link fails, arm locking alone will achieve this performance for all but approximately 1 h per year, when the arm length mismatch of the two remaining arms passes through zero. Therefore, the LISA sensitivity can be realized with arm locking and time-delay interferometry only, without any form of prestabilization.

McKenzie, Kirk; Spero, Robert E.; Shaddock, Daniel A.

2009-11-01

204

Performance of arm locking in LISA  

International Nuclear Information System (INIS)

For the Laser Interferometer Space Antenna (LISA) to reach its design sensitivity, the coupling of the free-running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. In this paper we detail an implementation of arm locking. We investigate orbital effects (changing arm lengths and Doppler frequencies), the impact of errors in the Doppler knowledge that can cause pulling of the laser frequency, and the noise limit of arm locking. Laser frequency pulling is examined in two regimes: at lock acquisition and in steady state. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultrastable oscillator (clock) noise, spacecraft motion, and shot noise. We find that clock noise and spacecraft motion limit the performance of dual arm locking in the LISA science band. Studying these issues reveals that although dual arm locking [A. Sutton and D. A. Shaddock, Phys. Rev. D 78, 082001 (2008)] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a modification to the dual arm-locking sensor, a hybrid of common and dual arm-locking sensors. This modified dual arm-locking sensor has the laser frequency pulling charensor has the laser frequency pulling characteristics and low-frequency noise coupling of common arm locking, but retains the control system advantages of dual arm locking. We present a detailed design of an arm-locking controller and perform an analysis of the expected performance when used with and without laser prestabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. With a time-delay error of 3 ns (equivalent of 1 m interspacecraft ranging error), time-delay interferometry (TDI) is capable of suppressing 300 Hz/?(Hz) of laser frequency noise to the required level. We show that if no interspacecraft laser links fail, arm locking alone surpasses this noise performance for the entire mission. If one interspacecraft laser link fails, arm locking alone will achieve this performance for all but approximately 1 h per year, when the arm length mismatch of the two remaining arms passes through zero. Therefore, the LISA sensitivity can be realized with arm locking and time-delay interferometry only, without any form of prestabilization.

205

Kinematics of an infinitely flexible robot arm  

Science.gov (United States)

An effort is made to define a command-and-control algorithm for a flexible robot arm design which maximizes flexibility through its large number of degrees-of-freedom, in the manner of a 'tentacle'. Algorithms including both forward and inverse kinematics are developed for commanding smooth arm motions in the presence of obstacles, on the basis of Catmull-Rom splines and local radius-of-curvature commands to discrete actuators along the length of the arm. Sample trajectories are examined, and a spline-curve algorithm is successfully applied for this arm configuration; the accuracy and collision-avoidance of the arm are verified by means of a simulation.

Choi, P. J.; Rice, J. A.; Cesarone, J. C.

1993-06-01

206

Regenerator cross arm seal assembly  

Science.gov (United States)

A seal assembly for disposition between a cross arm on a gas turbine engine block and a regenerator disc, the seal assembly including a platform coextensive with the cross arm, a seal and wear layer sealingly and slidingly engaging the regenerator disc, a porous and compliant support layer between the platform and the seal and wear layer porous enough to permit flow of cooling air therethrough and compliant to accommodate relative thermal growth and distortion, a dike between the seal and wear layer and the platform for preventing cross flow through the support layer between engine exhaust and pressurized air passages, and air diversion passages for directing unregenerated pressurized air through the support layer to cool the seal and wear layer and then back into the flow of regenerated pressurized air.

Jackman, Anthony V. (Indianapolis, IN)

1988-01-01

207

Dual arm master controller concept  

International Nuclear Information System (INIS)

The Advanced Servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented. 6 references, 3 figures

208

The DOE ARM Aerial Facility  

Energy Technology Data Exchange (ETDEWEB)

The Department of Energy Atmospheric Radiation Measurement (ARM) Program is a climate research user facility operating stationary ground sites that provide long-term measurements of climate relevant properties, mobile ground- and ship-based facilities to conduct shorter field campaigns (6-12 months), and the ARM Aerial Facility (AAF). The airborne observations acquired by the AAF enhance the surface-based ARM measurements by providing high-resolution in-situ measurements for process understanding, retrieval-algorithm development, and model evaluation that are not possible using ground- or satellite-based techniques. Several ARM aerial efforts were consolidated into the AAF in 2006. With the exception of a small aircraft used for routine measurements of aerosols and carbon cycle gases, AAF at the time had no dedicated aircraft and only a small number of instruments at its disposal. In this "virtual hangar" mode, AAF successfully carried out several missions contracting with organizations and investigators who provided their research aircraft and instrumentation. In 2009, AAF started managing operations of the Battelle-owned Gulfstream I (G-1) large twin-turboprop research aircraft. Furthermore, the American Recovery and Reinvestment Act of 2009 provided funding for the procurement of over twenty new instruments to be used aboard the G-1 and other AAF virtual-hangar aircraft. AAF now executes missions in the virtual- and real-hangar mode producing freely available datasets for studying aerosol, cloud, and radiative processes in the atmosphere. AAF is also engaged in the maturation and testing of newly developed airborne sensors to help foster the next generation of airborne instruments.

Schmid, Beat; Tomlinson, Jason M.; Hubbe, John M.; Comstock, Jennifer M.; Mei, Fan; Chand, Duli; Pekour, Mikhail S.; Kluzek, Celine D.; Andrews, Elisabeth; Biraud, S.; McFarquhar, Greg

2014-05-01

209

Control of flexible robotic arms, 1  

International Nuclear Information System (INIS)

Dynamic characteristics and control method of a flexible robotic arm of first degrees of freedom system are shown modelling a flexible arm as an elastic beam. Vibrations of the arm in positioning can be suppressed by the dynamic compensation with consideration of the arm flexibility, of which current robotic arms have more or less in manipulating payloads. Subsequently, a control method of a SCARA type of a second degree of freedom system is shown based on the local feedback with variable adaptive gains to suppress vibrations in positioning control. In case of arm collisions against other objects, a control method to recover the state before collision is also shown as an application. The control methods proposed here are not limited to this type of robotic arms, but also applicable in more general cases. (author)

210

Physiologically driven avian vocal synthesizer  

Science.gov (United States)

In this work, we build an electronic syrinx, i.e., a programmable electronic device capable of integrating biomechanical model equations for the avian vocal organ in order to synthesize song. This vocal prosthesis is controlled by the bird’s neural instructions to respiratory and the syringeal motor systems, thus opening great potential for studying motor control and its modification by sensory feedback mechanisms. Furthermore, a well-functioning subject-controlled vocal prosthesis can lay the foundation for similar devices in humans and thus provide directly health-related data and procedures.

Sitt, Jacobo D.; Arneodo, Ezequiel M.; Goller, Franz; Mindlin, Gabriel B.

2010-03-01

211

Method of synthesizing tungsten nanoparticles  

Science.gov (United States)

A method to synthesize tungsten nanoparticles has been developed that enables synthesis of nanometer-scale, monodisperse particles that can be stabilized only by tetrahydrofuran. The method can be used at room temperature, is scalable, and the product concentrated by standard means. Since no additives or stabilizing surfactants are required, this method is particularly well suited for producing tungsten nanoparticles for dispersion in polymers. If complete dispersion is achieved due to the size of the nanoparticles, then the optical properties of the polymer can be largely maintained.

Thoma, Steven G; Anderson, Travis M

2013-02-12

212

Arm locking for space-based laser interferometry gravitational wave observatories  

Science.gov (United States)

Laser frequency stabilization is a critical part of the interferometry measurement system of space-based gravitational wave observatories such as the Laser Interferometer Space Antenna (LISA). Arm locking as a proposed frequency stabilization technique transfers the stability of the long arm lengths to the laser frequency. The arm locking sensor synthesizes an adequately filtered linear combination of the interspacecraft phase measurements to estimate the laser frequency noise, which can be used to control the laser frequency. At the University of Florida we developed the hardware-based University of Florida LISA Interferometer Simulator to study and verify laser frequency noise reduction and suppression techniques under realistic LISA-like conditions. These conditions include the variable Doppler shifts among the spacecraft, LISA-like signal travel times, optical transponders, realistic laser frequency, and timing noise. We review the different types of arm locking sensors and discuss their expected performance in LISA. The presented results are supported by results obtained during experimental studies of arm locking under relevant LISA-like conditions. We measured the noise suppression as well as initial transients and frequency pulling in the presence of Doppler frequency errors. This work has demonstrated the validity and feasibility of arm locking in LISA.

Yu, Yinan; Mitryk, Shawn; Mueller, Guido

2014-09-01

213

Chemical Durability of Synthesized Sphene  

International Nuclear Information System (INIS)

The chemical durability of synthesized sphene, using CaCO3, TiO2 and H2SiO3 as raw materials by solid-state reaction, was researched by means of X-ray diffraction(XRD), scanning electron microscope(SEM) and atom absorbing spectrum(AAS). The results indicate that the synthesized sphene has a good chemical durability in the aqueous solution whose ph value is 5-9, the temperature and ph of the solution have important influences to its chemical durability in 1-21 days. The nominalized leach rate of Ca2+(42 d) is higher than Ti4+ about 2 orders of magnitude.When the ph is 7 at 90 degree C, the nominalized leaching rate of Ca2+(42 d) and Ti4+(42 d) are 3.33 x 10-3 and 1.33 x 10-5 g·m-2·d-1, respectively. When the ph is 7 at 25 degree C, the nominalized leach rate of Ca2+(42 d) and Ti4+(42 d) are 1.52 x 10-3 and 3.05 x 10-5 g·m-2·d-1, respectively. The nominalized leach rate of Ca2+(42 d) is 7.71 x 10-2 g·m-2·d-1, when the ph is 3 at 25 degree C. (authors)

214

Des femmes dans la France combattante pendant la Deuxième Guerre mondiale : Le Corps des Volontaires Françaises et le Groupe Rochambeau  

Directory of Open Access Journals (Sweden)

Full Text Available Cet article aborde la question de l’engagement des femmes dans l’Armée française pendant la Deuxième Guerre Mondiale grâce aux traces écrites qu’elles ont laissés.Dès 1940, plusieurs centaines de femmes rejoignent les rangs des FFL à Londres, mais aussi en Afrique du Nord (Algérie, Maroc, Tunisie. Elles s’engagent dans les trois corps d’Armée et sont présentes dans la plupart des services. Souvent dénigrées par les hommes, sous-estimées aussi, ces femmes accomplissent pourtant des tâches essentielles entre 1940 et 1945. Cet engagement moral, physique et souvent idéologique dans l’Armée de la Libération, devient pour la plupart d’entre elles un tournant définitif dans leur vie. Nombreuses sont celles qui ont éprouvé le besoin de raconter cette période si « particulière » de leur vie. La lecture des témoignages et des souvenirs permet de comprendre quand et comment s’est déroulé leur engagement. Car, contrairement aux idées reçues, elles n’étaient pas toutes dans les transmissions ou dans les services de santé. Elles n’étaient pas non plus « que » des AFAT (Auxiliaires féminines de l’Armée de Terre. Grâce à un panel d’autobiographies et de souvenirs de guerre, les points abordés ici seront donc ceux du contexte et des motivations de l’engagement, des postes occupés par ces femmes, ainsi que du regard que les libérateurs ont porté sur elles pendant mais surtout après la Libération.This article uses women’s writings to examine women’s voluntary enlistment in the French Army during World War II. As early as 1940, several hundred women joined the Free French Army’s ranks in London, but also in North Africa (Algeria, Morocco, Tunisia. They enlisted in the three army corps and were present in most services. These women carried out essential jobs between 1940 and 1945, although men often denigrated and underestimated their contributions. This moral, physical, and often ideological engagement in the Liberation Army became for most of them a permanent turning point in their lives. Many felt the need to write about this particular period of their lives. Their testimonies and memories reveal the context and motivations surrounding their decision to enlist. Contrary to general opinion, they were not just « AFAT » (Land Army’s Female Auxiliaries nor did they only serve in transmission or health services. The article then examines the nature of women’s jobs and the ways French soldiers described them during and after the Liberation.

Elodie Jauneau

2009-01-01

215

Azathia crown ethers carrying pyrene pendant as receptor molecules for metal sensor systems  

International Nuclear Information System (INIS)

A series of crown ethers carrying a pyrene group with nitrogen-sulfur donor atoms, that differ in having three, four and five sulfur atoms in the macrocycle was designed and synthesized by the reaction of the corresponding macrocyclic compound and 1-bromomethylpyrene. The influence of metal cations such as Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+ and Al3+ on the spectroscopic properties of the ligands was investigated in acetonitrile-dichloromethane (1:1) by means of absorption and emission spectrometry. Absorption spectra show isosbestic points in the spectrophotometric titration of Fe2+, Zn2+, Cu2+, Pb2+ and Hg2+. The results of spectrophotometric titration experiments disclosed the complexation compositions and complex stability constants of the novel ligands with Fe2+, Zn2+, Cu2+, Pb2+ and Hg2+ cations. The monoazatetrathia crown ether showed good sensitivity for Cu2+ with linearity in the range 5.0x10-7-2.5x10-6 M and detection limit of 1.6x10-8 M. - Research highlights: ? We report a series of crown ethers carrying a pyrene group with nitrogen-sulfur donor atoms. ? The influence of metal cations on the spectroscopic properties of the ligands is investigated. ? We have ligands is investigated. ? We have carried out the monoazatetrathia crown ether showed good sensitivity for Cu2+.

216

The polymer electrolyte based on polysiloxane containing both alkyl cyanide and oligo ethylene oxide pendants  

International Nuclear Information System (INIS)

The monomers (3-cyanopropyl) methylsiloxane cyclics (D4CN) and (3-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)propyl) methylsiloxane cyclics (D4TEG) were prepared by a hydrosilylation reaction of 2,4,6,8-tetramethylcyclotetrasiloxane (D4H) with allyl cyanide and tri(ethylene glycol) methyl allyl ether (allyl TEG), respectively, in toluene using a platinum(0)-1,3-divinyl-1,1,3,3-tetramethyl disiloxane complex as the catalyst. The new crosslinkable polymers with alkyl cyanide and ethylene oxide groups as the pendent were synthesized by ring opening polymerization and characterized by GPC and 1H NMR. And then, the crosslinked solid polymer electrolyte was prepared by UV radiation curing. The conductivities of samples were measured by impedance spectroscopy using an indium-tin oxide (ITO) electrode. As the results, the maximum ionic conductivities of the polymer were 1.15 x 10-5 S cm-1 at 20 deg. C and 1 x 10-4 S cm-1 at 60 deg. C. The electrolyte was stable electrochemically to 5 V versus Li+/Li at room temperature

217

Hydrogen Production using Nickel Electrocatalysts with Pendant Amines: Ligand Effects on Rates and Overpotentials  

Energy Technology Data Exchange (ETDEWEB)

A Ni-based electrocatalyst for H2 production, [Ni(8PPh2NC6H4Br)2](BF4)2, featuring eight-membered cyclic diphosphine ligands incorporating a single amine base, 1-para-bromo-phenyl-3,7-triphenyl-1-aza-3,7-diphosphacycloheptane (8PPh2NC6H4Br) has been synthesized and characterized. X-ray ?diffraction studies reveal that the cation of [Ni(8PPh2NC6H4Br)2(CH3CN)](BF4)2 has a distorted trigonal bipyramidal geometry. In CH3CN [Ni(8PPh2NC6H4Br)2]2+ is an electrocatalyst for reduction of protons, and it has a maximum turnover frequency for H2 production of 800 s-1 with a 700 mV overpotential (at Ecat/2) when using [(DMF)H]OTf as the acid. Addition of H2O to acidic CH3CN solutions of [Ni(8PPh2NC6H4Br)2]2+ results in an increase of the turnover frequency for H2 production to a maximum of 3,300 s?1 with an overpotential of 760 mV at Ecat/2. Computational studies carried out on [Ni(8PPh2NC6H4Br)2]2+ indicate the observed catalytic rate is limited by formation of non-productive protonated isomers, diverting active catalyst from the catalytic cycle. The results of this research show that proton delivery from the exogenous acid to the correct position on the proton relay of the metal complex is essential for fast H2 production. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Wiese, Stefan; Kilgore, Uriah J.; Ho, Ming-Hsun; Raugei, Simone; DuBois, Daniel L.; Bullock, R. Morris; Helm, Monte L.

2013-11-01

218

Electrochemistry and electrochromism of a poly(cyclopentadithiophene) derivative with a viologen pendant  

International Nuclear Information System (INIS)

N-Methyl-N'-(6-4H-cyclopenta[2,1-b:3,4-b']dithiophene-4-ylhexyl)-4,4' -bipyridinium dihexafluorophosphate (CPDT-V2+-Me) was synthesized. The monomer was electropolymerized on a glassy carbon or an ITO electrode in a potentiodynamic mode to form the corresponding polymer P(CPDT-V2+-Me) on the electrodes. During the electropolymerization, two redox peaks of the viologen (V) moiety increased up to several cycles and then decreased while the redox peak of P(CPDT) moiety still increased. Especially, a new oxidative peak a in the range of ca. -0.4 and 0 V versus Ag/Ag+ appeared and increased up to several cycles. Peak a almost disappeared after the redox peaks of the viologen moiety almost disappeared. As a result of cyclic voltammetric study, it was shown that peak a originated from the oxidation of reduced viologen moiety via P(CPDT)-mediated electron transfer mechanism. We also found that the electroactivity of viologen moiety in P(CPDT-V2+-Me) decreased significantly when the potential was scanned to the second viologen redox (V0/V·+). In practical applications, the polymer can be used in the potential range from the first viologen redox to P(CPDT) redox. The polymer turned into highly transparent P(CPDT?+-V2+-Me), blue P(CPDT-V2+-Me), dark violet P(CPDT-V·+-Me), and violet P(CPDT-V0-Me) approximately at 0.8, -0.4, -0.8, and -1.7 V versus Ag/Ag+, respectively

219

A new strategy for highly efficient single-drop microextraction with a liquid-gas compound pendant drop.  

Science.gov (United States)

Herein, a simple assembly was designed via a capillary and a funnel-like cap to achieve liquid-gas compound pendant drop (CPD) microextraction with great convenience. Due to the increased contact area and adhesion force between the capillary tip and the drop, the proposed method provides considerable flexibility in producing CPDs with different air bubble sizes. Four pesticides were chosen as model analytes to evaluate the proposed method. By using a 1 ?L chlorobenzene droplet containing a 1 ?L air bubble at a stirring rate of 700 rpm, a 70 to 135-fold enrichment of pesticides was obtained within 3.4 minutes. As compared with a typical SDME, the proposed method showed a 2-fold increase of enrichment factors and a 4-fold decrease of extraction time. Improvement of the extraction efficiency could be ascribed to the increased surface area of the droplet, and the thin film phenomena further improved the extraction kinetics through effective agitation. The results indicate that CPD microextraction could serve as a promising sample pretreatment method for automated high-throughput analyses in a wide variety of research areas. PMID:24691490

Xie, Hai-Yang; Yan, Jian; Jahan, Sharmin; Zhong, Ran; Fan, Liu-Yin; Xiao, Hua; Jin, Xin-Qiao; Cao, Cheng-Xi

2014-05-21

220

Fabrication and bioproperties of raspberry-type hybrid nanoparticles of Au-thioethyl pendant ligand@chitosan.  

Science.gov (United States)

Synthesis of nanoparticles with desired size/morphology has enormous importance, especially in the compelling field of nanotechnology. In this case, a novel kind of raspberry-type hybrid nanoparticles was prepared by hybridization of chitosan (CS) with thioethyl pendant ligand (TPL) modified Au nanoparticles (Au-TPL@CS NPs). Such method was based on ionic gelation using sodium tripolyphosphate as a counterion. The blood compatibility of Au-TPL@CS NPs was characterized by coagulation tests, plasma recalcification time, hemolysis assay, morphological changes of red blood cells (RBCs) and complement activation in vitro. The results showed that Au-TPL@CS NPs exhibited good blood compatibility. The possible underlying mechanism was also present. Finally, the direct electron transfer reactivity of the Hemoglobin/Au-TPL@CS NPs/multi-walled carbon nanotubes/glassy carbon electrode was investigated with cyclic voltammetry measurements. The biosensor exhibited a good electrocatalytic activity to the reduction of H2O2. Such new type of Au-TPL@CS NPs provides a promising platform of biological system for early illness detection and treatment in future. PMID:23627074

Huang, Bin; Tong, Fengyu; Chen, Yeting; Zhu, Qinshu; Xing, Lei; Lv, Mengqi; Mao, Chun; Lu, Zuhong; Shen, Jian

2013-01-01

 
 
 
 
221

Role of pendant proton relays and proton-coupled electron transfer on the hydrogen evolution reaction by nickel hangman porphyrins.  

Science.gov (United States)

The hangman motif provides mechanistic insights into the role of pendant proton relays in governing proton-coupled electron transfer (PCET) involved in the hydrogen evolution reaction (HER). We now show improved HER activity of Ni compared with Co hangman porphyrins. Cyclic voltammogram data and simulations, together with computational studies using density functional theory, implicate a shift in electrokinetic zone between Co and Ni hangman porphyrins due to a change in the PCET mechanism. Unlike the Co hangman porphyrin, the Ni hangman porphyrin does not require reduction to the formally metal(0) species before protonation by weak acids in acetonitrile. We conclude that protonation likely occurs at the Ni(I) state followed by reduction, in a stepwise proton transfer-electron transfer pathway. Spectroelectrochemical and computational studies reveal that upon reduction of the Ni(II) compound, the first electron is transferred to a metal-based orbital, whereas the second electron is transferred to a molecular orbital on the porphyrin ring. PMID:25298534

Bediako, D Kwabena; Solis, Brian H; Dogutan, Dilek K; Roubelakis, Manolis M; Maher, Andrew G; Lee, Chang Hoon; Chambers, Matthew B; Hammes-Schiffer, Sharon; Nocera, Daniel G

2014-10-21

222

A complex of cyclohexane-1,2-diaminoplatinum with an amphiphilic biodegradable polymer with pendant carboxyl groups.  

Science.gov (United States)

A biodegradable and amphiphilic copolymer, MPEG-b-P(LA-co-MCC), which contains pendant carboxyl groups, was chosen as a drug carrier for the active anticancer part (DACH-Pt) of oxaliplatin to form an MPEG-b-P(LA-co-MCC/Pt) complex. It was able to self-assemble into micelles with a mean diameter of 30-40 nm, and a surface potential near -10 mV. The typical platinum content was 10 wt.%. The micelles showed acid-responsive drug release kinetics, which is beneficial for drug release in the intracellular environment. The Pt(II) species were released mainly in the form of DACH-Pt-Cl(2) in 150 mM NaCl solution and DACH-Pt(2+)-(H(2)O)(2) in pure water according to the results obtained by high-performance liquid chromatography coupled with inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy. In vitro evaluation showed that the micelles displayed the same or higher cytotoxicities against SKOV-3, HeLa, and EC-109 cancer cells compared with oxaliplatin. The enhanced cytotoxicity against SKOV-3 cells is attributed to effective internalization of the micelles by the cells via endocytosis and the sensitivity of SKOV-3 cells to platinum drugs. This novel biodegradable and amphiphilic copolymer-based platinum drug will have great potential application in clinical use. PMID:22281944

Xiao, Haihua; Zhou, Dongfang; Liu, Shi; Zheng, Yonghui; Huang, Yubin; Jing, Xiabin

2012-05-01

223

Dual arm master controller development  

International Nuclear Information System (INIS)

The advanced servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented. This work was performed as part of the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory. 5 refs., 7 figs., 1 tab

224

Star distribution in the Orion spiral arm  

International Nuclear Information System (INIS)

The structure of the Orion spiral arm is studied by numerical experiments, assuming that in each direction considered the star distribution along the line of sight is a combination of two Gaussian laws. The corresponding parameters are evaluated for four Milky Way fields; the bimodal laws now fit the observations by the chi2 criterion. In the Orion arm the line-of-sight star densities follow asymmetric curves, steeper at the outer edge of the arm

225

World Military Expenditures and Arms Transfers (WMEAT)  

Science.gov (United States)

The US Arms Control and Disarmament Agency has placed online the full text of its 1996 WMEAT report, a reference on military expenditure, arms transfers, armed forces, and related economic data for 172 countries over the 1985-1995 decade. The data is comprehensive, up-to-date, and accompanied by analyses and highlights. Users may also choose to download selected portions of the larger report, including Highlights and Country Rankings.

226

Conflict, famine and the arms trade.  

Science.gov (United States)

Armed conflict has had horrendous humanitarian effects, causing 22 million deaths, over 80 per cent of them civilian, since 1945 and resulting today in 19 million refugees and 24 million displaced persons. War results in economic collapse, and high levels of military spending decrease regional stability. Benefits to the producers are limited or negative and developed countries should diversify away from arms production. There is a need for greater awareness in the developed countries, an end to the secrecy besetting the arms trade, and restructuring of the industry. A Code of Conduct governing arms exports is proposed. PMID:7752994

Judd, F

1995-01-01

227

MODELING AND SIMULATION OF ROBOTIC HUMANOID ARM  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper block model and machine model of Robotic humanoid arm has been generated Using MATLAB Simulink. Equations of Kinematics are derived by using D-H notation. By this equation and inverse kinematicsparameters for the motion trajectory have been determined. Kinematic parameters are divided into two groups namely, link parameters and joint parameters. Geometric model and motion of robotic humanoid arm with two link model with 3 Degree of freedom and arm with palm and fingers with 18 degree of freedom has been realized. Virtual simulation of the arm is also first step in actually controlling the mechanical structure.

RANJEET RANJAN

2012-06-01

228

World military expenditures and arms transfers, 1989  

Energy Technology Data Exchange (ETDEWEB)

The report, the twentieth in the series issued by the Arms Control and Disarmament Agency, is intended to serve as a convenient reference on military expenditures, arms transfers, armed forces, and related economic data for 144 countries over the 1978-1988 decade. It provides comprehensive, up-to-date, and accurate data, accompanied by pertinent analyses and highlights. The issue includes two essays, one on chemical weapons proliferation and US efforts to control it, and another on diversification of sources for Third World arms imports.

1990-10-01

229

Synthese de champs sonores adaptative  

Science.gov (United States)

La reproduction de champs acoustiques est une approche physique au probleme technologique de la spatialisation sonore. Cette these concerne l'aspect physique de la reproduction de champs acoustiques. L'objectif principal est l'amelioration de la reproduction de champs acoustiques par "synthese de champs acoustiques" ("Wave Field Synthesis", WFS), une approche connue, basee sur des hypotheses de champ libre, a l'aide du controle actif par l'ajout de capteurs de l'erreur de reproduction et d'une boucle fermee. Un premier chapitre technique (chapitre 4) expose les resultats d'appreciation objective de la WFS par simulations et mesures experimentales. L'effet indesirable de la salle de reproduction sur les qualites objectives de la WFS fut illustre. Une premiere question de recherche fut ensuite abordee (chapitre 5), a savoir s'il est possible de reproduire des champs progressifs en salle dans un paradigme physique de controle actif: cette possibilite fut prouvee. L'approche technique privilegiee, "synthese de champs adaptative" ("Adaptive Wave Field Synthesis" [AWFS]), fut definie, puis simulee (chapitre 6). Cette approche d'AWFS comporte une originalite en controle actif et en reproduction de champs acoustiques: la fonction cout quadratique representant la minimisation des erreurs de reproduction inclut une regularisation de Tikhonov avec solution a priori qui vient de la WFS. L'etude de l'AWFS a l'aide de la decomposition en valeurs singulieres (chapitre 7) a permis de comprendre les mecanismes propres a l'AWFS. C'est la deuxieme principale originalite de la these. L'algorithme FXLMS (LMS et reference filtree) est modifie pour l'AWFS (chapitre 8). Le decouplage du systeme par decomposition en valeurs singulieres est illustre dans le domaine du traitement de signal et l'AWFS basee sur le controle independant des modes de rayonnement est simulee (chapitre 8). Ce qui constitue la troisieme originalite principale de cette these. Ces simulations du traitement de signal montrent l'efficacite des algorithmes et la capacite de l'AWFS a attenuer les erreurs attribuables a des reflexions acoustiques. Le neuvieme chapitre presente des resultats experimentaux d'AWFS. L'objectif etait de valider la methode et d'evaluer les performances de l'AWFS. Un autre algorithme prometteur est aussi teste. Les resultats demontrent la bonne marche de l'AWFS et des algorithmes testes. Autant dans le cas de la reproduction de champs harmoniques que dans le cas de la reproduction de champs a large bande, l'AWFS reduit l'erreur de reproduction de la WFS et les effets indesirables causes par les lieux de reproduction.

Gauthier, Philippe-Aubert

230

Stress analysis for robot arm version 2  

International Nuclear Information System (INIS)

The design of a robot needs to be analyzed to ensure the specification and requirement by the user is full filled. Therefore, stress analysis has been performed on the robot arm version 2 after its complete fabrication. This paper discusses the result of the analysis and proposed measures to improve the future design of robot arm. (author)

231

Research in lightweight elastic robotic arms  

Science.gov (United States)

The program involved a series of individual projects coordinated to develop controls for a flexible light weight robot arm. A hydraulically actuated 3-link robot arm was installed on a PRAB hydraulic base, and was designed of tubular steel. A PERT program chart was prepared (appendix B) on which various interrelated project milestones were projected.

Nartker, T. A.

1993-06-01

232

Design of a biomimetic robotic octopus arm  

International Nuclear Information System (INIS)

This paper reports the rationale and design of a robotic arm, as inspired by an octopus arm. The octopus arm shows peculiar features, such as the ability to bend in all directions, to produce fast elongations, and to vary its stiffness. The octopus achieves these unique motor skills, thanks to its peculiar muscular structure, named muscular hydrostat. Different muscles arranged on orthogonal planes generate an antagonistic action on each other in the muscular hydrostat, which does not change its volume during muscle contractions, and allow bending and elongation of the arm and stiffness variation. By drawing inspiration from natural skills of octopus, and by analysing the geometry and mechanics of the muscular structure of its arm, we propose the design of a robot arm consisting of an artificial muscular hydrostat structure, which is completely soft and compliant, but also able to stiffen. In this paper, we discuss the design criteria of the robotic arm and how this design and the special arrangement of its muscular structure may bring the building of a robotic arm into being, by showing the results obtained by mathematical models and prototypical mock-ups

233

Simple model of the arms race  

International Nuclear Information System (INIS)

A simple model of a two-party arms race is developed based on the principle that the race will continue so long as either side can unleash an effective first strike against the other side. The model is used to examine how secrecy, the ABM, MIRV-ing, and an MX system affect the arms race

234

Films on the arms race  

Energy Technology Data Exchange (ETDEWEB)

Films convey the historical perspectives, the biographical stories, the insights of the participants, and the horror of nuclear war - far better than can any physicist. While films are not very efficient for covering details, derivation, or numbers, they can not be beaten in showing what really happens in a nuclear explosion, in getting across general concepts, in illustrating the parameters of a problem, and the problem itself. Most importantly, films and TV can reach the people who must be informed about these issues if we are to resolve the problems. The author points out how films can contribute to an understanding of the issues of the arms race and nuclear war, with references to specific films. An annotated bibliography of 37 films is then presented.

Dowling, J.

1983-01-01

235

AMF-3 ARM Climate Research Facility  

Science.gov (United States)

The U.S. Department of Energy (DOE) provides scientific infrastructure and data archives to the international Arctic research community through a national user facility. (www.arm.gov). A New ARM Climate Research Facility AMF-3 (ARM Mobile Facility 3) will be located on the North Slope of Alaska, at Oliktok Point. The infrastructure at Oliktok will be designed to be mobile and it may be relocated in the future to support other ARM science missions. AMF-3 instruments include: scanning precipitation radar, scanning cloud radar, Raman lidar, eddy correlation flux systems, upgraded ceilometer, Balloon sounding system, AERI, micropulse lidar, millimeter cloud radar along with all the standard metrological measurements. Unmanned Aerial Systems operations and tethered balloons in the Oliktok area will also be supported. Data from these instruments will be placed in the ARM data archives and available to the international research community.

Helsel, F.; Cook, R.; Lucero, D.; Yellowhorse, L.; Zirzow, J.

2013-12-01

236

Syntheses of metastable trialuminides by mechanical alloying  

International Nuclear Information System (INIS)

Mechanical alloying of Al-25 at% X (X=Hf, Nb, Ta, Ti, Zr, and V) elemental powders was studied to synthesize L12 phase-trialuminides with nanocrystalline structure. The microstructural evolution and mechanical properties of the synthesized powders were investigated in order to correlate the possibility of the formation of L12 and nanocrystalline structures with the synthesizing techniques. Effects of ternary elements on the formation of L12 phase and the thermal stability were also examined. (orig.)

237

27 CFR 479.193 - Arms Export Control Act.  

Science.gov (United States)

... 2010-04-01 false Arms Export Control Act. 479.193 Section 479...Applicable § 479.193 Arms Export Control Act. For provisions relating...implements of war, see the Arms Export Control Act (22 U.S.C....

2010-04-01

238

Doppler ultrasound exam of an arm or leg  

Science.gov (United States)

... large arteries and veins in the arms and legs. ... need to remove clothes from the arm or leg being examined. ... to help diagnose: Arteriosclerosis of the arms or legs Blood clot (deep vein thrombosis) Venous insufficiency The ...

239

Robotic Arm Comprising Two Bending Segments  

Science.gov (United States)

The figure shows several aspects of an experimental robotic manipulator that includes a housing from which protrudes a tendril- or tentacle-like arm 1 cm thick and 1 m long. The arm consists of two collinear segments, each of which can be bent independently of the other, and the two segments can be bent simultaneously in different planes. The arm can be retracted to a minimum length or extended by any desired amount up to its full length. The arm can also be made to rotate about its own longitudinal axis. Some prior experimental robotic manipulators include single-segment bendable arms. Those arms are thicker and shorter than the present one. The present robotic manipulator serves as a prototype of future manipulators that, by virtue of the slenderness and multiple- bending capability of their arms, are expected to have sufficient dexterity for operation within spaces that would otherwise be inaccessible. Such manipulators could be especially well suited as means of minimally invasive inspection during construction and maintenance activities. Each of the two collinear bending arm segments is further subdivided into a series of collinear extension- and compression-type helical springs joined by threaded links. The extension springs occupy the majority of the length of the arm and engage passively in bending. The compression springs are used for actively controlled bending. Bending is effected by means of pairs of antagonistic tendons in the form of spectra gel spun polymer lines that are attached at specific threaded links and run the entire length of the arm inside the spring helix from the attachment links to motor-driven pulleys inside the housing. Two pairs of tendons, mounted in orthogonal planes that intersect along the longitudinal axis, are used to effect bending of each segment. The tendons for actuating the distal bending segment are in planes offset by an angle of 45 from those of the proximal bending segment: This configuration makes it possible to accommodate all eight tendons at the same diameter along the arm. The threaded links have central bores through which power and video wires can be strung (1) from a charge-coupled-device camera mounted on the tip of the arms (2) back along the interior of the arm into the housing and then (3) from within the housing to an external video monitor.

Mehling, Joshua S.; Difler, Myron A.; Ambrose, Robert O.; Chu, Mars W.; Valvo, Michael C.

2010-01-01

240

Le volontariat armé au sein des milices nationalistes pendant la Guerre civile espagnole, 1936-1939 El voluntariado armado en las milicias nacionalistas durante la Guerra Civil Española  

Directory of Open Access Journals (Sweden)

Full Text Available La guerre civile espagnole fut le fruit d’une conjonction de nombreux éléments, mais il fallut l’échec d’un coup d’État organisé par une partie de l’armée pour la faire éclater. Cette tentative de coup d’État « survient après une phase de politisation des masses sans équivalent antérieur, même pendant la Révolution de 1868 ». Cette politisation massive, alliée à une radicalisation de la vie politique espagnole durant la seconde République, peut expliquer en partie l’engagement de nombreux Esp...

Diego Ségalas

2011-02-01

 
 
 
 
241

Design Lower Arm Using Optimum Approach  

Directory of Open Access Journals (Sweden)

Full Text Available In the automotive industry, the riding comfort and handling qualities of an automobile are greatly affected by the suspension system. This paper presents the robust design of vehicle suspension arm using stochastic design improvement (SDI technique based on Monte Carlo simulation. The main goal of this study is to determine the optimum design for the suspension arm. The structural model of the suspension arm was utilizing the Solid works and aluminum alloys (AA7075-T6 are selected as a suspension arm materials. The linear static stress distribution is investigated using the commercial Finite element analysis package, and dynamic analysis was performed using NASTRAN software. SDI has been performed to the design. A target output behavior is selected from the output variables available in the analysis. The result shows that the lower arm design has a higher capability to stand higher pressure as 9.18 MPa with the stress acted on lower arm is 41 MPa. The new parameter of material can be chose as optimum result for the lower suspension arm.

Adel Mahmoud Bash

2011-01-01

242

The evolution of neuroArm.  

Science.gov (United States)

Intraoperative imaging disrupts the rhythm of surgery despite providing an excellent opportunity for surgical monitoring and assessment. To allow surgery within real-time images, neuroArm, a teleoperated surgical robotic system, was conceptualized. The objective was to design and manufacture a magnetic resonance-compatible robot with a human-machine interface that could reproduce some of the sight, sound, and touch of surgery at a remote workstation. University of Calgary researchers worked with MacDonald, Dettwiler and Associates engineers to produce a requirements document, preliminary design review, and critical design review, followed by the manufacture, preclinical testing, and clinical integration of neuroArm. During the preliminary design review, the scope of the neuroArm project changed to performing microsurgery outside the magnet and stereotaxy inside the bore. neuroArm was successfully manufactured and installed in an intraoperative magnetic resonance imaging operating room. neuroArm was clinically integrated into 35 cases in a graded fashion. As a result of this experience, neuroArm II is in development, and advances in technology will allow microsurgery within the bore of the magnet. neuroArm represents a successful interdisciplinary collaboration. It has positive implications for the future of robotic technology in neurosurgery in that the precision and accuracy of robots will continue to augment human capability. PMID:23254809

Sutherland, Garnette R; Wolfsberger, Stefan; Lama, Sanju; Zarei-nia, Kourosh

2013-01-01

243

Tracing the spiral arms in IP Pegasi  

CERN Document Server

We report the analysis of time-resolved spectroscopy of IP Pegasi in outburst with eclipse mapping techniques to investigate the location and geometry of the observed spiral structures. We were able to obtain an improved view of the spiral structures with the aid of light curves extracted in velocity bins matching the observed range of velocities of the spiral arms combined with a double default map tailored for reconstruction of asymmetric structures. Two-armed spiral structures are clearly seen in all eclipse maps. The arms are located at different distances from the disc centre. The ``blue'' arm is farther out in the disc (R= 0.55 +/- 0.05 R_{L1}) than the ``red'' arm (R= 0.30 +/- 0.05 R_{L1}). There are evidences that the velocity of the emitting gas along the spiral pattern is lower than the Keplerian velocity for the same disc radius. The discrepancy is smaller in the outer arm (measured velocities 10-15 per cent lower than Keplerian) and is more significant in the inner arm (observed velocities up to 4...

Baptista, R; Harlaftis, E T; Marsh, T R; Steeghs, D

2005-01-01

244

Naval arms control: Tons of options?  

International Nuclear Information System (INIS)

Arms reductions have reached the US Navy, the most arms control averse of the US services, with budget-driven cuts in numbers of ships and personnel, and President Bush's unilateral withdrawal of tactical nuclear weapons. Soviet President Mikhail Gorbachev's rejoinder not only replicated the Bush initiative for naval weapons, but also called for the destruction of all those weapons, many of which would simply be placed in secure storage ashore under Bush's approach. Can formal, negotiated naval arms control agreements be far behind? Post-war history suggests that such naval arms agreements will remain out of reach. But post-war history has been confounded repeatedly by the events of the past three years. There are, in fact, negotiated naval limits that would enhance the predictability of US-Soviet military relations, and smooth the path of the naval retrenchment already underway on both sides. The Bush-Gorbachev reciprocal withdrawals of naval tactical nuclear arms deal with the most urgent and dangerous issue for naval arms control, improve the US Navy's survivability by drastically reducing the nuclear threat, and improve its flexibility by eliminating the security and political issues associated with carrying nuclear arms. It would be highly desirable, however, to formalize and verify these withdrawals, placing withdrawn weapons under jointly monitored, secure control, to preserve options for further cuts in the future

245

Composites comprising biologically-synthesized nanomaterials  

Science.gov (United States)

The present disclosure describes composite materials containing a polymer material and a nanoscale material dispersed in the polymer material. The nanoscale materials may be biologically synthesized, such as tellurium nanorods synthesized by Bacillus selenitireducens. Composite materials of the present disclosure may have optical limiting properties and find use in optical limiting devices.

Curran, Seamus; Dias, Sampath; Blau, Werner; Wang, Jun; Oremland, Ronald S; Baesman, Shaun

2013-04-30

246

Pitch Angle of Galactic Spiral Arms  

CERN Document Server

One of the key parameters that characterize spiral arms in disk galaxies is a pitch angle that measures the inclination of a spiral arm to the direction of galactic rotation. The pitch angle differs from galaxy to galaxy, which suggests that the rotation law of galactic disks determines it. In order to investigate the relation between the pitch angle of spiral arms and the shear rate of galactic differential rotation, we perform local $N$-body simulations of pure stellar disks. We find that the pitch angle increases with the epicycle frequency and decreases with the shear rate and obtain the fitting formula. This dependence is explained by the swing amplification mechanism.

Michikoshi, Shugo

2014-01-01

247

Pitch Angle of Galactic Spiral Arms  

Science.gov (United States)

One of the key parameters that characterizes spiral arms in disk galaxies is a pitch angle that measures the inclination of a spiral arm to the direction of galactic rotation. The pitch angle differs from galaxy to galaxy, which suggests that the rotation law of galactic disks determines it. In order to investigate the relation between the pitch angle of spiral arms and the shear rate of galactic differential rotation, we perform local N-body simulations of pure stellar disks. We find that the pitch angle increases with the epicycle frequency and decreases with the shear rate and obtain the fitting formula. This dependence is explained by the swing amplification mechanism.

Michikoshi, Shugo; Kokubo, Eiichiro

2014-06-01

248

Near Infrared Observations of the Local Arm  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Observations of the Local Arm have been carried out in the near-infrared with the 1.5 m ``Carlos S\\'anchez'' telescope in Tenerife. A model of the disc with adjustable parameters fitted to reproduce the DIRBE-COBE survey, has been subtracted from the observational data in order to obtain a clean map of the Local Arm, uncontaminated by other components of the disc. The arm is more than 70 pc over the plane and is wider than 200 pc. At a latitude of about $80^\\circ$ the deviat...

Porcel, C.; Garzon, F.; Jimenez-vicente, J.; Battaner, E.

1998-01-01

249

Universal Controller Design Using Arm Controller  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, different control strategies are discussed and design of universal (process controller on ARM embedded platform is proposed. The same controller support feedback, cascade, ratio and feed forward control strategy. The LPC2148 kit (ARM7 controller is used for the application which has many features which are also discussed in the paper.MODBUS RTU protocol is used for communication.GUI is developed in Wonderware In touch (SCADA software. Keil µvision 4 IDE is used for programming ARM controller

Mohsin A. Bandi, Mr. Naimesh B. Mehta

2012-04-01

250

The Perseus Arm Pulsar Survey  

Science.gov (United States)

The Perseus Arm Pulsar Survey covers the region of the sky enclosed by Galactic longitudes 200° PMPS) with the aim of finding interesting individual pulsars for follow-up observations, and better understanding the radial distribution of the pulsar population in the outer Galaxy. As for the PMPS, the observations have been performed using the 21-cm multibeam receiver on the Parkes 64-m radio telescope, the only difference on the set-up being the sampling time, halved to 125 ?s. A total of 913 pointings, each of duration 2100 s, were collected. The system provided a limiting flux density, for long-period pulsars with 5 per cent duty cycle, of ˜0.22 mJy. Data analysis resulted in the detection of 32 pulsars of which 14 were new discoveries. One of these, J0721-2038, has a period of 15.5 ms and is in a binary orbit with a period of 5.5 d around an intermediate-mass (>0.46 M?) companion. We present timing parameters, obtained with the Parkes and Lovell telescopes for all new pulsars and update the results of the pulsar population studies in light of the new discoveries. Our knowledge of the radial density function of pulsars continues to be dominated by uncertainties in the Galactic distribution of free electrons.

Burgay, M.; Keith, M. J.; Lorimer, D. R.; Hassall, T. E.; Lyne, A. G.; Camilo, F.; D'Amico, N.; Hobbs, G. B.; Kramer, M.; Manchester, R. N.; McLaughlin, M. A.; Possenti, A.; Stairs, I. H.; Stappers, B. W.

2013-02-01

251

The arms race between fishers  

Science.gov (United States)

An analysis of the changes in the Dutch demersal fishing fleet since the 1950s revealed that competitive interactions among vessels and gear types within the constraints imposed by biological, economic and fisheries management factors are the dominant processes governing the dynamics of fishing fleets. Double beam trawling, introduced in the early 1960s, proved a successful fishing method to catch deep burying flatfish, in particular sole. In less than 10 years, the otter trawl fleet was replaced by a highly specialised beam trawling fleet, despite an initial doubling of the loss rate of vessels due to stability problems. Engine power, size of the beam trawl, number of tickler chains and fishing speed rapidly increased and fishing activities expanded into previously lightly fished grounds and seasons. Following the ban on flatfish trawling within the 12 nautical mile zone for vessels of more than 300 hp in 1975 and with the restriction of engine power to 2000 hp in 1987, the beam trawl fleet bifurcated. Changes in the fleet capacity were related to the economic results and showed a cyclic pattern with a period of 6-7 years. The arms race between fishers was fuelled by competitive interactions among fishers: while the catchability of the fleet more than doubled in the ten years following the introduction of the beam trawl, a decline in catchability was observed in reference beam trawlers that remained the same. Vessel performance was not only affected by the technological characteristics but also by the number and characteristics of competing vessels.

Rijnsdorp, Adriaan D.; Poos, Jan Jaap; Quirijns, Floor J.; HilleRisLambers, Reinier; De Wilde, Jan W.; Den Heijer, Willem M.

252

Is Negotiated Arms Control Possible?  

Science.gov (United States)

I had a very difficult time deciding on the topic of this talk, since Viki's interests cover such a broad range of activities with which I am also concerned. You can hear next week about the recent exciting work with the SLAC storage rings, a description of the design principles of such rings, and their future promise for new physics through Professor Richter's Loeb Lectures at Harvard. Talking about inelastic lepton scattering during an M.I.T. conference would be bringing coals to Newcastle, since the local M.I.T. physicists are primary agents in these experiments. Broad problems in high energy physics policy, for instance such questions as the relation between University users and the large laboratories, are matters of current concern to Viki and his friends in high energy physics, but I doubt whether many would sit still for a one-hour talk on that subject. I would therefore like to use the opportunity to express some personal views on certain current issues in arms control, since I know that there exists a wide spectrum of involvement and also opinion on this subject in the local community...

Panofsky, W. K. H.

2014-11-01

253

Coke Formation During Hydrocarbons Pyrolysis. Part One: Steam Cracking Formation de coke pendant la pyrolise des hydrocarbures. Première partie : vapocraquage  

Directory of Open Access Journals (Sweden)

Full Text Available Thermal cracking is always accompanied by coke formation, which becomes deposited on the wall and limits heat transfers in the reactor while increasing pressure drops and possibly even plugging up the reactor. This review article covers undesirable coking operations in steam craking reactors. These coking reactions may take place in the gas phase and/or on the surface of the reactor, with coke being produced during pyrolysis by a complex mechanism that breaks down into a catalytic sequence and a noncatalytic sequence. After a brief description of different experimental set-ups used to measure the coke deposition, on the basis of research described in the literature, the different factors and their importance for coke formation are listed. In particular, we describe the effects of surface properties of stainless-steel and quartz reactors as well as the influence of the cracked feedstock, of temperature, of dilution, of residence time and of the conversion on coke deposition. Some findings about the morphology of coke are described and linked to formation mechanisms. To illustrate this review, some particularly interesting research is referred to concerning models developed to assess coke formation during propane steam cracking. Le craquage thermique est toujours accompagné de la formation de coke qui, en se déposant à la paroi, limite les transferts de chaleur au réacteur, augmente les pertes de charges et même peut boucher celui-ci. Cet article fait le point sur les réactions indésirables de cokage dans les réacteurs de vapocraquage. Ces réactions de cokage peuvent avoir lieu en phase gazeuse et/ou sur la surface du réacteur, le coke étant produit pendant la pyrolyse par un mécanisme complexe qui se décompose en une séquence catalytique et une séquence non catalytique. Après une brève présentation des différents montages expérimentaux utilisés pour mesurer le dépôt de coke, il est mentionné, à partir de travaux de la littérature, les différents facteurs et leur importance sur la formation du coke. On présentera en particulier les effets de propriétés de surface de réacteurs en inox et en quartz, ainsi que l'influence de la charge craquée, de la température, de la dilution, du temps de séjour et de la conversion sur les dépôts de coke. Quelques résultats sur la morphologie du coke seront présentés et reliés aux mécanismes de formation du coke. Pour illustrer ce travail, on reprendra quelques études particulièrement intéressantes sur des modèles d'évaluation de la formation de coke développés pour le vapocraquage de propane.

Weill J.

2006-11-01

254

A comprehensive analysis of DgNCT coefficients for pendant-geometry cone-beam breast computed tomography  

International Nuclear Information System (INIS)

The use of a computed tomography (CT) scanner specifically designed for breast imaging has been proposed by several investigators. In this study, the radiation dose due to breast CT was evaluated using Monte Carlo techniques over a range of parameters pertinent to the cone-beam pendant geometry thought to be most appropriate. Monte Carlo dose computations were validated by comparison with physical measurements made on a prototype breast CT scanner under development in our laboratory. The Monte Carlo results were then used to study the influence of cone angle, the use of a beam flattening ('bow-tie') filter, glandular fraction, breast length and source-to-isocenter distance. These parameters were studied over a range of breast diameters from 10 to 18 cm, and for both monoenergetic (8-140 keV by 1 keV intervals) and polyenergetic x-ray beams (30-100 kVp by 5 kVp intervals. Half value layer at 80 kVp=5.3 mm Al). A parameter referring to the normalized glandular dose in CT (DgNCT) was defined which is the ratio of the glandular dose in the breast to the air kerma at isocenter. There was no significant difference (p=0.743) between physically measured and Monte Carlo derived results. Fan angle, source-to-isocenter distance, and breast length have relatively small influences on the radiation dose in breast CT. Glandular fraction (0% versus 100%) for 10 cm breasts at 80 kVp had approximately a 10% effect on DgNCT, and a 20% effect was observed for an 18 , and a 20% effect was observed for an 18 cm breast diameter. The use of a bow-tie filter had the potential to reduce breast dose by approximately 40%. X-ray beam energy and breast diameter had significant influence on the DgNCT parameters, with higher DgNCT values for higher energy beams and smaller breast diameters. DgNCT values (mGy/mGy) at 80 kVp ranged from 0.95 for an 8 cm diam 50% glandular breast to 0.78 for an 18 cm 50% glandular breast. The results of this investigation should be useful for those interested computing the glandular breast dose for geometries relevant to dedicated breast CT

255

A comprehensive analysis of DgN(CT) coefficients for pendant-geometry cone-beam breast computed tomography.  

Science.gov (United States)

The use of a computed tomography (CT) scanner specifically designed for breast imaging has been proposed by several investigators. In this study, the radiation dose due to breast CT was evaluated using Monte Carlo techniques over a range of parameters pertinent to the cone-beam pendant geometry thought to be most appropriate. Monte Carlo dose computations were validated by comparison with physical measurements made on a prototype breast CT scanner under development in our laboratory. The Monte Carlo results were then used to study the influence of cone angle, the use of a beam flattening ("bow-tie") filter, glandular fraction, breast length and source-to-isocenter distance. These parameters were studied over a range of breast diameters from 10 to 18 cm, and for both monoenergetic (8-140 keV by 1 keV intervals) and polyenergetic x-ray beams (30-100 kVp by 5 kVp intervals. Half value layer at 80 kVp = 5.3 mm Al). A parameter referring to the normalized glandular dose in CT (DgN(CT)) was defined which is the ratio of the glandular dose in the breast to the air kerma at isocenter. There was no significant difference (p = 0.743) between physically measured and Monte Carlo derived results. Fan angle, source-to-isocenter distance, and breast length have relatively small influences on the radiation dose in breast CT. Glandular fraction (0% versus 100%) for 10 cm breasts at 80 kVp had approximately a 10% effect on DgN(CT), and a 20% effect was observed for an 18 cm breast diameter. The use of a bow-tie filter had the potential to reduce breast dose by approximately 40%. X-ray beam energy and breast diameter had significant influence on the DgN(CT) parameters, with higher DgN(CT) values for higher energy beams and smaller breast diameters. DgN(CT) values (mGy/mGy) at 80 kVp ranged from 0.95 for an 8 cm diam 50% glandular breast to 0.78 for an 18 cm 50% glandular breast. The results of this investigation should be useful for those interested computing the glandular breast dose for geometries relevant to dedicated breast CT. PMID:15000608

Boone, J M; Shah, N; Nelson, T R

2004-02-01

256

Light duty utility arm baseline system description  

International Nuclear Information System (INIS)

This document describes the configuration of the Light Duty Utility Arm (LDUA) Baseline System. The baseline system is the initial configuration of the LDUA system that will be qualified for hot deployment in Hanford single shell underground storage tanks

257

The Kampala Convention and obligations armed groups  

Directory of Open Access Journals (Sweden)

Full Text Available The Kampala Convention imposes a number of obligations on armed groups in order to better protect IDPs; the challenge now is to encourage such groups to recognise these obligations....

Katinka Ridderbos

2011-03-01

258

Science team participation in the ARM program  

International Nuclear Information System (INIS)

This progress report discusses the Science Team participation in the Atmospheric Radiation Measurement (ARM) Program for the period of October 31, 1992 to November 1, 1993. This report summarized the research accomplishments of six papers

259

Dermatitis, atopic on the arms (image)  

Science.gov (United States)

This person has inherited allergic skin inflammation (atopic dermatitis) on the arms. Red (erythematous), scaly plaques can be seen on the inside of the elbows (antecubital fossa). In adults, atopic dermatitis usually ...

260

An arms control phoenix: Building transparency through an arms trade register  

Energy Technology Data Exchange (ETDEWEB)

The idea of an arms trade register was first discussed at the League of Nations. The League of Nations spent considerable time addressing ways to supervise and control the international trade in arms. The League's work in this regard was carried out at various conferences. In conjunction with the political negotiations, the League Secretariat compiled statistical information on the international trade in arms, in anticipation of a political decision to implement such a scheme. In the post-1945 era, the idea of a register was dormant for a number of years as attention was focused on nuclear arms rather than conventional arms. Recently, it has again come to the forefront. Using the frameworks of arms control theory and regime theory, the concept of the idea of an arms trade register as a viable way to promote transparency in the international arms trade. A study has just been completed for the Secretary-General of the United Nations recommending the immediate implementation of a register. However, this will not necessarily ensure its successful implementation. While the nature of the arms trade has changed over the past century in terms of its patterns, scope and sophistication, little has changed in the attitudes towards dealing with it. In fact, the arguments articulated at the United Nations have demonstrated little new thinking, and mirror those made at the League of Nations. As a result, efforts to implement an arms trade register in the late twentieth century confront many of the same obstacles, but with the added twist that, due to changes in the nature of the arms trade, the register may no longer be the appropriate instrument of supervision. In the wake of the Gulf War, the advocacy of an arms trade register by the United Kingdom, Japan, and Canada, amongst others, offers new hope to its supporters, but the implementation of the proposal will still required the resolution of the problems that have traditionally confronted the concept.

MacDonald, M.K.

1991-01-01

 
 
 
 
261

Proton-coupled electron transfer in azobenzene/hydrazobenzene couples with pendant acid-base functions. Hydrogen-bonding and structural effects.  

Science.gov (United States)

Electron transfer in azobenzene derivatives bearing two carboxylic acid groups is coupled with intramolecular proton transfer in a stepwise manner in the title 2e(-) + 2H(+) redox couple. The presence of the pendant acid-base functions pushes the redox chemistry of the azo/hydrazo couple toward positive potentials by as much as 0.75 V. This is essentially the result of H-bonding of one of the nitrogen atoms by the neighboring carboxylic group and H-bonding of one carboxylate by the neighboring protonated nitrogen atom. The two electron-transfer reactions, particularly the second one, are accompanied by strong structural changes, which results in the occurrence of a square scheme mechanism in which electron transfer and structural change are not concerted. These are typical phenomena that are likely to be encountered when attempting to boost proton-coupled electron-transfer stoichiometric or catalytic processes by installing pendant acid-base functionalities in the close vicinity of the reacting center. PMID:24921200

Savéant, Jean-Michel; Tard, Cédric

2014-06-25

262

Segmentgürtel mit mehrteiliger Anhängekombination - Ein Frauenschmuckgürtel der Renaissance (Segmented Girdles with a Multi-part Pendant Construction - a Woman´s Decorative Girdle of the Renaissance  

Directory of Open Access Journals (Sweden)

Full Text Available The finds of this study consist of two belts, and a total of 24 fully preserved fragments show a different high number of conserved segments. They were primarily found as scattered finds in the Brandenburg districts Prignitz, Ostprignitz-Ruppin, Havelland, Upper Havel, district Jericho, Oder-Spree district, Dahme-Spreewald, Uckermark and in Berlin at the Mühlendamm/Spree. According to the present analysis, the examined girdles show a typical composition with fas-tenings consisting of oblong one-piece segments with blunt terminals and with a multi-part pendant construction. Based on formal characteristics they can be categorized as female decorative girdles of the type “Segmented girdles with multi-part pendant construction”.Some examples of fully preserved girdles have even been assembled from segments of several different types of manufacture and decorative motifs. This leads to the conclusion that in general these girdles were probably not produced by specialised craftsmen. Another aim of the present analysis was to work out specific characteristics facilitating the distinction of girdle segments from book-clasps. In this respect, the closing construction was of particular relevance. It could be clarified that toggle fastenings with a spade- or mushroom-shaped hole on the fastening sheet can undoubtedly be identified as girdle elements.

Jörg Harder

2010-12-01

263

Arm exponents in high dimensional percolation  

CERN Document Server

We study the probability that the origin is connected to the sphere of radius r (an arm event) in critical percolation in high dimensions, namely when the dimension d is large enough or when d>6 and the lattice is sufficiently spread out. We prove that this probability decays like 1/r^2. Furthermore, we show that the probability of having k disjoint arms to distance r emanating from the vicinity of the origin is 1/r^2k.

Kozma, Gady

2009-01-01

264

A New Spiral Arm of the Galaxy: The Far 3-Kpc Arm  

CERN Document Server

We report the detection in CO of the far-side counterpart of the well-known expanding 3-Kpc Arm in the central region of the Galaxy. In a CO longitude-velocity map at b = 0 deg the Far 3-Kpc Arm can be followed over at least 20 deg of Galactic longitude as a faint lane at positive velocities running parallel to the Near Arm. The Far Arm crosses l = 0 deg at +56 km/s, quite symmetric with the -53 km/s expansion velocity of the Near Arm. In addition to their symmetry in longitude and velocity, we find that the two arms have linewidths (~21 km/s), linear scale heights (~103 pc FWHM), and H2 masses per unit length (~4.3 x 10^6 Mo/kpc) that agree to 26% or better. Guided by the CO, we have also identified the Far Arm in high-resolution 21 cm data and find, subject to the poorly known CO-to-H2 ratio in these objects, that both arms are predominately molecular by a factor of 3-4. The detection of these symmetric expanding arms provides strong support for the existence of a bar at the center of our Galaxy and should ...

Dame, T M

2008-01-01

265

Arm & Interarm Star Formation in Spiral Galaxies  

CERN Document Server

We investigate the relationship between spiral arms and star formation in the grand-design spirals NGC 5194 and NGC 628 and in the flocculent spiral NGC 6946. Filtered maps of near-IR (3.6 micron) emission allow us to identify "arm regions" that should correspond to regions of stellar mass density enhancements. The two grand-design spirals show a clear two-armed structure, while NGC 6946 is more complex. We examine these arm and interarm regions, looking at maps that trace recent star formation - far-ultraviolet (GALEX NGS) and 24 micron emission (Spitzer, SINGS) - and cold gas - CO (Heracles) and HI (Things). We find the star formation tracers and CO more concentrated in the spiral arms than the stellar 3.6 micron flux. If we define the spiral arms as the 25% highest pixels in the filtered 3.6 micron images, we find that the majority (60%) of star formation tracers occurs in the interarm regions; this result persists qualitatively even when considering the potential impact of finite data resolution and diffu...

Foyle, Kelly; Walter, Fabian; Leroy, Adam

2010-01-01

266

Arms trade as a global international problem  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this paper is to highlight the great social danger resulting from uncontrolled trade in arms and military equipment. A large number of terrorist attacks in the world show that uncontrolled arms trade is a growing problem for international security. In order to provide the same protection, the problem of uncontrolled arms and military equipment, which is the major international business, should be viewed from several aspects. To this end, after defining weapons, their production and trade, the authors have presented one of the ways the leading companies in the military-industrial complex provide themselves a market for sale of arms and military equipment, thus creating the conditions that contribute to expanding of their military companies. As the world’s largest exporters of arms and military equipment the United States, Russia and China give a short historical account of their arms trafficking. Then, considering the fact that the amount of weapons would unlikely diminish, the authors have pointed out that states should find a way to control the movement of weapons in the world preventing terrorist to take hold of them.

Spalevi? Žaklina

2013-01-01

267

Dynamic analysis of the Schilling Titan 7F robotic arm  

International Nuclear Information System (INIS)

A seven degree of freedom hydraulically actuated robotic arm is modeled using DADS. The low level control system for the arm is included in the model, as is the hydraulic system, and model results are compared with experimental results for the arm. Vane type rotary actuators are used in this arm, and a method for modeling them with DADS elements is presented. 10 figs

268

The Trajectory Synthesizer Generalized Profile Interface  

Science.gov (United States)

The Trajectory Synthesizer is a software program that generates aircraft predictions for Air Traffic Management decision support tools. The Trajectory Synthesizer being used by researchers at NASA Ames Research Center was restricted in the number of trajectory types that could be generated. This limitation was not sufficient to support the rapidly changing Air Traffic Management research requirements. The Generalized Profile Interface was developed to address this issue. It provides a flexible approach to describe the constraints applied to trajectory generation and may provide a method for interoperability between trajectory generators. It also supports the request and generation of new types of trajectory profiles not possible with the previous interface to the Trajectory Synthesizer. Other enhancements allow the Trajectory Synthesizer to meet the current and future needs of Air Traffic Management research.

Lee, Alan G.; Bouyssounouse, Xavier; Murphy, James R.

2010-01-01

269

Syntheses and Functional Properties of Phthalocyanines  

Directory of Open Access Journals (Sweden)

Full Text Available Metal phthalocyanine tetrasulfonic acids, metal phthalocyanine octacarboxylic acids, metal octakis(hexyloxymethylphthalocyanines, and metal anthraquinocyanines have been synthesized. Then, zinc bis(1,4-didecylbenzo-bis(3,4-pyridoporphyrazines, the cyclotetramerization products of a 1:1 mixture of 3,6-didecylphthalonitrile and 3,4-dicyanopyridine, were synthesized. Futher, subphthalocyanine and its derivatives, with substituents such as thiobutyl and thiophenyl moieties were synthesized. Electrochemical measurements were performed on the abovementioned phthalocyanine derivatives and analogues in order to examine their electron transfer abilities and electrochemical reaction mechanisms in an organic solvent. Moreover, 1,4,8,11,15,18,22,25-octakis(thiophenylmethyl phthalocyanes were synthesized. The Q-bands of the latter compounds appeared in the near-infrared region. Furthermore, non-colored transparent films in the visible region can be produced.

Keiichi Sakamoto

2009-08-01

270

Enantioselective total syntheses of cyathane diterpenoids.  

Science.gov (United States)

A Personal Account describing the enantioselective total syntheses of cyathane diterpenoids achieved in the Nakada group. A convergent approach to the cyathane scaffold, the [5-6-7] tricyclic carbon skeleton commonly found in cyathane diterpenoids, has been developed using the catalytic asymmetric intramolecular cyclopropanation (CAIMCP) and baker's yeast reduction. This approach has been successfully applied for the enantioselective total syntheses of (+)-allocyathin B2 , (-)-erinacine B, and (-)-erinacine E. The total synthesis of (-)-erinacine E has been achieved via the acyl group migratory intramolecular aldol reaction, which prevents the retro-aldol reaction and allows the construction of the strained structure. The highly efficient and stereoselective total syntheses of (-)-scabronines G, A, D, and (-)-episcabronine A have been achieved via the oxidative dearomatization/inverse electron demand Diels-Alder reaction cascade. Cascade reactions comprising three and five consecutive reactions were employed for the highly efficient total syntheses of (-)-scabronine A and (-)-episcabronine A, respectively. PMID:25065736

Nakada, Masahisa

2014-08-01

271

Synthesis and characterization of three-arm polyamide 6-polyurethane block copolymer by monomer casting process  

International Nuclear Information System (INIS)

Three-arm polyamide 6-polyurethane (PA 6-PU) block copolymers were synthesized using ?-caprolactam as a monomer, caprolactam sodium as a catalyst, and a three-arm carbamyl caprolactam terminated polyurethane (PU) prepolymer as macroactivator. The three-arm PU prepolymer was formed from polyether glycerol (PPG) and diphenyl methane-4,4' diisocyanate (MDI). The block copolymers were obtained using the monomer casting process (MC) of ?-caprolactam at different content of three-arm PU prepolymer (5-20%). In increasing the content of the soft phase, in Fourier transform infrared (FTIR), a displacement was observed in the band at 1637 cm-1, which is assigned to the amide I of polyamide 6 (PA 6) shifted to a higher wavenumber. This suggested an interaction between the amide group of the PA 6 and the urethane group of the PU. The effects of the PU prepolymer content on the mechanical properties of the block copolymers were investigated. The results showed that the impact strength of the block copolymers at 25 oC and -50 oC temperature could be significantly improved. The crystallization and melting behaviors, structure and thermal properties and morphological characteristic of the block copolymers were studied using the different techniques such as differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMTA) and scanning electronic microscopy (SEM).

272

An efficient strategy to syntheses of isoflavones.  

Science.gov (United States)

Isoflavones were synthesized by two steps in good yields, starting from commercially available 2-hydroxyacetophenones and benzene analogs. First, intermediate 3-(dimethylamino)-1-(2-hydroxyphenyl) prop-2-en-1-ones were obtained by the condensation of 2-hydroxyacetophenones and DMF-DMA in DMF with high yields. Second, isoflavones were synthesized by irradiation of 3-(dimethylamino)-1-(2-hydroxyphenyl)prop- 2-en-1-ones in the presence of iodine using benzene analogs as solvent under a mercury lamp. PMID:25086575

Liu, Longzhu; Wang, Qiuya; Zhang, Zunting; Zhang, Qiong; Du, Zichao; Xue, Dong; Wang, Tingting

2014-11-01

273

SYNTHESIZED CAPITAL AND MODERNIZATION OF SOCIETY  

Directory of Open Access Journals (Sweden)

Full Text Available At present in Ukraine, the processes of integration and globalization are deepening, the impact of economic factors in all spheres of life has increased, and innovative investment model of development is being formed in the state. The research of issues related to the synthesized capital in the context of modernization complies with modern challenges of national scientific thought, taking into account the fact that capitalization of synthesized capital can increase its overall value and can be regarded as a means of society modernization, reflecting the importance and urgency of this work.The objective of the article is to establish the scientific and theoretical principles of synthesized capitalization as a means of society modernization.The continuous development of a country, region, an enterprise within the scope of modernization is feasible under conditions of capitalization, resulting in the processes associated with transfer of synthesized capital, increasing the relative value added. We believe that capitalization of synthesized capital should be seen as the means of modernization of society and should lead to the following:· accumulation of synthesized (human, intellectual and social capital of the country, followed by its distribution at the national level (it is about creating national and regional integrated structures, TNK and clusters which may include universities;· creation of conditions for the transformation of synthesized capital in to geo-economic capital of the country, which should ensure both efficient creation of innovative model of an enterprise development and socio-economic development of the country.The authors’ calculations along with updating capitalization of synthesized capital allows to specify the strategic directions of the development of the country towards sustainability of its socio-economic configuration of modernization.

N. Gavkalova

2012-06-01

274

Stratagies in synthesizing short-lived radiopharmaceuticals for PET  

International Nuclear Information System (INIS)

Positron Emission Tomography (PET) is one of the most exciting medical imaging modalities and it provides quantitative three dimensional images of specific biochemical, physiological and pathophysiological processes in living human organs like Brain, Heart etc. PET uses short lived radiopharmaceuticals synthesized in situ. Considering the short half lives of the radionuclides (11C-20 min, 18F-110 min, 13N-10 min), the synthesis has to be designed in such a way that the process does not involve any complicated step or long procedures. Since these compounds have to be injected in patients immediately after preparation, extreme precautions have to be taken so that the final product is pure, sterile and apyrogenic. Since a large amount of radioactivity is involved, the synthesis has to be performed in a closed shielded open-quotes Hot Cellclose quotes. The authors have developed a new strategy for the preparation of these compounds using disposable synthetic units. In order to avoid radiation exposure to the operator, they are suggesting the use of a master slave manipulator arm. They routinely prepare several PET compounds based on this technique for clinical and research studies. The final preparations are subjected to sterility and pyrogen testings and found to conform to the USP standard. Radiolabeling of specific drugs for diagnostic purposes is a new and exciting area for chemists who wish to enter the field of medical imaging enter the field of medical imaging

275

Psychoacoustic Analysis of Synthesized Jet Noise  

Science.gov (United States)

An aircraft noise synthesis capability is being developed so the annoyance caused by proposed aircraft can be assessed during the design stage. To make synthesized signals as realistic as possible, high fidelity simulation is required for source (e.g., engine noise, airframe noise), propagation and receiver effects. This psychoacoustic study tests whether the jet noise component of synthesized aircraft engine noise can be made more realistic using a low frequency oscillator (LFO) technique to simulate fluctuations in level observed in recordings. Jet noise predictions are commonly made in the frequency domain based on models of time-averaged empirical data. The synthesis process involves conversion of the frequency domain prediction into an audible pressure time history. However, because the predictions are time-invariant, the synthesized sound lacks fluctuations observed in recordings. Such fluctuations are hypothesized to be perceptually important. To introduce time-varying characteristics into jet noise synthesis, a method has been developed that modulates measured or predicted 1/3-octave band levels with a (<20Hz) LFO. The LFO characteristics are determined through analysis of laboratory jet noise recordings. For the aft emission angle, results indicate that signals synthesized using a generic LFO are perceived as more similar to recordings than those using no LFO, and signals synthesized with an angle-specific LFO are more similar to recordings than those synthesized with a generic LFO.

Okcu, Selen; Rathsam, Jonathan; Rizzi, Stephen A.

2013-01-01

276

Stereo matching image processing by synthesized color and the characteristic area by the synthesized color  

Science.gov (United States)

We have developed the stereo matching image processing by synthesized color and the corresponding area by the synthesized color for ranging the object and image recognition. The typical images from a pair of the stereo imagers may have some image disagreement each other due to the size change, missed place, appearance change and deformation of characteristic area. We constructed the synthesized color and corresponding color area with the same synthesized color to make the distinct stereo matching. We constructed the synthesized color and corresponding color area with the same synthesized color by the 3 steps. The first step is making binary edge image by differentiating the focused image from each imager and verifying that differentiated image has normal density of frequency distribution to find the threshold level of binary procedure. We used Daubechies wavelet transformation for the procedures of differentiating in this study. The second step is deriving the synthesized color by averaging color brightness between binary edge points with respect to horizontal direction and vertical direction alternatively. The averaging color procedure was done many times until the fluctuation of averaged color become negligible with respect to 256 levels in brightness. The third step is extracting area with same synthesized color by collecting the pixel of same synthesized color and grouping these pixel points by 4 directional connectivity relations. The matching areas for the stereo matching are determined by using synthesized color areas. The matching point is the center of gravity of each synthesized color area. The parallax between a pair of images is derived by the center of gravity of synthesized color area easily. The experiment of this stereo matching was done for the object of the soccer ball toy. From this experiment we showed that stereo matching by the synthesized color technique are simple and effective.

Akiyama, Akira; Mutoh, Eiichiro; Kumagai, Hideo

2014-09-01

277

Research on the measurement technology of effective arm length of swing arm profilometer  

Science.gov (United States)

When the swing arm profilometer(SAP) measuring the mirror, the effective arm length of SAP which haves an obvious influence on the measurement results of the mirror surface shape needs to be measured accurately. It requires the measurement uncertainty of the effective arm length to reach 10?m in order to meet the measurement requirements, in this paper, we present a kind of technology based on laser tracker to measure the effective arm length of SAP. When the swing arm rotates around the shaft axis of swing arm rotary stage, the probe and two laser tracker balls form three sections of circular arc around the shaft axis of swing arm rotary stage in space. Laser tracker tracks and measures the circular arcs of two laser tracker balls, the center coordinates of the circular plane of circular arc can be calculated by data processing. The linear equation that passes through the two center coordinates is the equation of the shaft axis of rotary stage, the vertical distance from the probe to the shaft axis of rotary stage which can be calculated refer to the equation from the point to the line is the effective arm length. After Matlab simulation, this measurement method can meet the measurement accuracy.

Chen, Lin; Jing, Hongwei; Wei, Zhongwei; Li, Jie; Cao, Xuedong

2014-09-01

278

Arm 7 Based Robotic Arm Control By Electronic Gesture Recognition Unit Using Mems  

Directory of Open Access Journals (Sweden)

Full Text Available Mechatronics is one of the present trends in the era of computing in today’s system automation industry and control. The proposed project is one such attempt of implementing an accelerometer based system to communicate with an industrial robotic arm wirelessly. This project comprises of controlling of robotic arm powered with ARM7 based LPC1768 core. The LC1768 core has to be interfaced with DC motors of robotic arm to control the movements of robotic arm. MEMS is a three dimensional accelerometer sensor used for this purpose, this accelerometer sensor captures gestures of human-arm and produces three analog output voltages in three dimensional axes. And two flex sensors are used to control the gripper movement. For various movements of accelerometer and flex sensorscorresponding characters will be sent to the ARM7 core wirelessly using 2.4GHz RF module. And depending on the received character robotic arm can be controlled in Dynamic or Static mode by communicating with EEPROM using I2C protocol

K.Brahmani#1 , K.S.Roy#2 , Mahaboob Ali

2013-04-01

279

Spiral Arms as Cosmic Ray Source Distributions  

CERN Document Server

There is evidence that the distribution of suspected cosmic ray sources are associated with the spiral arm structure of galaxies. It is yet not clearly understood what effect such a cosmic ray source distribution has on the particle transport in our Galaxy. We use the PICARD code to perform high-resolution 3D simulations of electrons and protons in galactic propagation scenarios that include four-arm and two-arm logarithmic spiral cosmic ray source distributions with and without a central bar structure as well as the spiral arm configuration of the NE2001 model for the distribution of free electrons in the Milky Way. Results of these simulation are compared to an axisymmetric radial source distribution. Also, effects on the cosmic ray flux and spectra due to different positions of the Earth relative to the spiral structure are studied. We find that high energy electrons are strongly confined to their sources and the obtained spectra largely depend on the Earth's position relative to the spiral arms. Similar f...

Werner, M; Strong, A W; Reimer, O

2014-01-01

280

The development of multipurpose fluorination synthesizer  

International Nuclear Information System (INIS)

The purpose of this project is developing the multipurpose fluorination synthesizer, which can produce various fluorination compounds that are used for the PET. The main results are as follows 1. We have intended to design a multipurpose synthesizer that can be used not only for the FDG synthesis, which is the most popular in the F-18 radioisotope labeled radiopharmaceutical, but also for the FLT and FET synthesis. In addition, the developed synthesizer is allowed to connect and control the HPLC system so that we can produce another type of fluorination compound different from the FDG. 2. The program suitable to the multipurpose fluorination synthesizer should manages appropriate sequences separately for each step. In other words, the program should can be modified by user at any time, and the user using the program is allowed to define or modify each step easily through the GUI interface. 3. The yield of the FDG synthesis is about 7% higher than the previous synthesizer and the radiochemical yield of [18F]FLT synthesis is 96% using the network based module We will provide a chance that having a technology transfer to domestic cyclotron manufacturers. The technology transferred domestic cyclotron manufacturers may accomplish a kind of package product by producing the PET radioisotopes and radiopharmaceuticals, and they can increase their marketability

 
 
 
 
281

ARM Cloud Retrieval Ensemble Data Set (ACRED)  

Energy Technology Data Exchange (ETDEWEB)

This document describes a new Atmospheric Radiation Measurement (ARM) data set, the ARM Cloud Retrieval Ensemble Data Set (ACRED), which is created by assembling nine existing ground-based cloud retrievals of ARM measurements from different cloud retrieval algorithms. The current version of ACRED includes an hourly average of nine ground-based retrievals with vertical resolution of 45 m for 512 layers. The techniques used for the nine cloud retrievals are briefly described in this document. This document also outlines the ACRED data availability, variables, and the nine retrieval products. Technical details about the generation of ACRED, such as the methods used for time average and vertical re-grid, are also provided.

Zhao, C; Xie, S; Klein, SA; McCoy, R; Comstock, JM; Delanoë, J; Deng, M; Dunn, M; Hogan, RJ; Jensen, MP; Mace, GG; McFarlane, SA; O’Connor, EJ; Protat, A; Shupe, MD; Turner, D; Wang, Z

2011-09-12

282

Adaptive Control Strategies for Flexible Robotic Arm  

Science.gov (United States)

The control problem of a flexible robotic arm has been investigated. The control strategies that have been developed have a wide application in approaching the general control problem of flexible space structures. The following control strategies have been developed and evaluated: neural self-tuning control algorithm, neural-network-based fuzzy logic control algorithm, and adaptive pole assignment algorithm. All of the above algorithms have been tested through computer simulation. In addition, the hardware implementation of a computer control system that controls the tip position of a flexible arm clamped on a rigid hub mounted directly on the vertical shaft of a dc motor, has been developed. An adaptive pole assignment algorithm has been applied to suppress vibrations of the described physical model of flexible robotic arm and has been successfully tested using this testbed.

Bialasiewicz, Jan T.

1996-01-01

283

Spiral arms, comets and terrestrial catastrophism  

International Nuclear Information System (INIS)

A review is presented of an hypothesis of terrestrial catastrophism in which comets grow in molecular clouds and are captured by the Sun as it passes through the spiral arms of the Galaxy. Assuming that comets are a major supplier of the Earth-crossing (Appollo) asteroid population, the latter fluctuates correspondingly and leads to episodes of terrestrial bombardment. Changes in the rotational momentum of core and mantle, generated by impacts, lead to episodes of magnetic field reversal and tectonic activity, while surface phenomena lead to ice-ages and mass extinctions. An episodic geophysical history with an interstellar connection is thus implied. If comets in spiral arms are necessary intermediaries in the process of star formation, the theory also has implications relating to early solar system history and galactic chemistry. These aspects are briefly discussed with special reference to the nature of spiral arms. (author)

284

Fusion of hand and arm gestures  

Science.gov (United States)

In order to improve the link between an operator and its machine, some human oriented communication systems are now using natural languages like speech or gesture. The goal of this paper is to present a gesture recognition system based on the fusion of measurements issued from different kind of sources. It is necessary to have some sensors that are able to capture at least the position and the orientation of the hand such as Dataglove and a video camera. Datagloge gives a measure of the hand posture and a video camera gives a measure of the general arm gesture which represents the physical and spatial properties of the gesture, and based on the 2D skeleton representation of the arm. The measurements used are partially complementary and partially redundant. The application is distributed on intelligent cooperating sensors. The paper presents the measurement of the hand and the arm gestures, the fusion processes, and the implementation solution.

Coquin, D.; Benoit, E.; Sawada, H.; Ionescu, B.

2005-12-01

285

ARM Based Remote control Toy Car  

Directory of Open Access Journals (Sweden)

Full Text Available With ever increasing popularity of ARM core based microcontroller for embedded systems, So decided to incorporate project utilizing ARM based microcontroller LPC 2129.In this project , ARM based LPC 2129 kit studied & after careful examination of various functions of pins, suitable pins were chosen & necessary hardware were added to develop simple application of remote control of car . A normal control toy car has four keys for controlling forward, reverse, right & left turn motions. At any particular time, only one function can beincorporated and it is observed that car just runs at constant speed and turns abruptly. Our work demonstrates much better control with smoother acceleration and deceleration along with capability to turn while running at lower speed. PWM capability of LPC 2129 utilized to control speed of motor using pulse width modulator. Currently two route paths were programmed for control.LCD display interfaced to kit to indicate present state of car.

Harish G Langar

2013-05-01

286

Detection of the chirality of C alpha-methylated alpha-amino acids with a dynamic helical poly(phenylacetylene) bearing aza-18-crown-6 ether pendants.  

Science.gov (United States)

A stereoregular poly(phenylacetylene) bearing the aza-18-crown-6 ether pendants (poly-1) was found to form a predominantly one-handed helix upon complexation with optically active C(alpha)-methylated alpha-amino acids and their amide derivatives including typical meteoritic C(alpha)-methylated alpha-amino acids such as C(alpha)-methyl norvaline and C(alpha)-methyl valine. The complexes exhibited an induced circular dichroism (ICD) in the UV-visible region of the polymer backbone. Therefore, poly-1 can be used as a novel probe for detection of the chirality of C(alpha)-methylated alpha-amino acids. The effect of the enantiomeric excess (ee) of C(alpha)-methylated alpha-amino acids on the helicity induction in poly-1 was also investigated. PMID:16856161

Morino, Kazuhide; Kaptein, Bernard; Yashima, Eiji

2006-09-01

287

Two new helical compounds based on Keggin clusters and N-donor multidentate ligand: Syntheses, structures and properties  

Science.gov (United States)

Two isostructural polyoxometalate-based inorganic-organic hybrids with 1D helical chain, [CuH3L2(GeMo12O40)]·2H2O (1) and [CuH3L2(SiMo12O40)]·2H2O (2), where L=2,4,5-tri(4-pyridyl)-imidazole have been synthesized under hydrothermal conditions. It is the first time to use the L ligand to synthesis the Keggin-type polyoxometalate-based inorganic-organic hybrids. The two compounds possess the left- and right-handed helical chains and the POMs as pendants attach in the helical chains through Cu-O bonds. The two compounds have been characterized by elemental analyses, infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), X-ray photoelectron spectra (XPS), thermogravimetric analysis (TGA) and photoluminescent spectroscopy. Moreover, nitrogen adsorption-desorption measurement, electrochemical and photocatalysis properties for degradation of methylene blue (MB) upon a UV irradiation of compound 1 have been examined.

Zhou, Shi; Liu, Bo; Li, Xiao-Min; Shi, Tian; Chen, Ya-Guang

2014-11-01

288

Two-Armed, Mobile, Sensate Research Robot  

Science.gov (United States)

The Anthropomorphic Robotic Testbed (ART) is an experimental prototype of a partly anthropomorphic, humanoid-size, mobile robot. The basic ART design concept provides for a combination of two-armed coordination, tactility, stereoscopic vision, mobility with navigation and avoidance of obstacles, and natural-language communication, so that the ART could emulate humans in many activities. The ART could be developed into a variety of highly capable robotic assistants for general or specific applications. There is especially great potential for the development of ART-based robots as substitutes for live-in health-care aides for home-bound persons who are aged, infirm, or physically handicapped; these robots could greatly reduce the cost of home health care and extend the term of independent living. The ART is a fully autonomous and untethered system. It includes a mobile base on which is mounted an extensible torso topped by a head, shoulders, and two arms. All subsystems of the ART are powered by a rechargeable, removable battery pack. The mobile base is a differentially- driven, nonholonomic vehicle capable of a speed >1 m/s and can handle a payload >100 kg. The base can be controlled manually, in forward/backward and/or simultaneous rotational motion, by use of a joystick. Alternatively, the motion of the base can be controlled autonomously by an onboard navigational computer. By retraction or extension of the torso, the head height of the ART can be adjusted from 5 ft (1.5 m) to 6 1/2 ft (2 m), so that the arms can reach either the floor or high shelves, or some ceilings. The arms are symmetrical. Each arm (including the wrist) has a total of six rotary axes like those of the human shoulder, elbow, and wrist joints. The arms are actuated by electric motors in combination with brakes and gas-spring assists on the shoulder and elbow joints. The arms are operated under closed-loop digital control. A receptacle for an end effector is mounted on the tip of the wrist and contains a force-and-torque sensor that provides feedback for force (compliance) control of the arm. The end effector could be a tool or a robot hand, depending on the application.

Engelberger, J. F.; Roberts, W. Nelson; Ryan, David J.; Silverthorne, Andrew

2004-01-01

289

The ARM unpiloted aerospace vehicle (UAV) program  

Energy Technology Data Exchange (ETDEWEB)

Unmanned aerospace vehicles (UAVs) are an important complement to the DOE`s Atmospheric Radiation Measurement (ARM) Program. ARM is primarily a ground-based program designed to extensively quantify the radiometric and meteorological properties of an atmospheric column. There is a need for airborne measurements of radiative profiles, especially flux at the tropopause, cloud properties, and upper troposphere water vapor. There is also a need for multi-day measurements at the tropopause; for example, in the tropics, at 20 km for over 24 hours. UAVs offer the greatest potential for long endurance at high altitudes and may be less expensive than piloted flights. 2 figs.

Sowle, D. [Mission Research Corporation, Santa Barbara, CA (United States)

1995-09-01

290

Worldwide report: Arms control, [February 1, 1986  

Energy Technology Data Exchange (ETDEWEB)

Partial contents of this report include: SDI and Space arms, Slat and Start Issues, Violations, Treaty, Fabrications, Intermediate Range Nuclear Forces, Missiles, Nuclear Issues, Deployment, Chemical Weapons, Biological Weapons, European Conferences, Nuclear Testing and Free Zone Proposals, Ussr Attacks, Rejection, Moratorium Stances, TV Interviews, Public, International Calls, Delegates, Friendships, Environmental, Domestics, International Services, Nuclear Blast, White House Assurance, Non-nuclear Claims, Blast Exposes, Perle Justification, Antisatellite Weapon Tests, X-ray Laser, Related issues, Nuclear Free Zones, Peaceful, Nuclear Weapons, Television Services, Resumption, Arm Controls.

NONE

1986-02-01

291

78 FR 65451 - Agency Information Collection (Shoulder and Arm Conditions Disability Benefits Questionnaire...  

Science.gov (United States)

...Arm Conditions Disability Benefits Questionnaire) Activity Under OMB Review AGENCY...Arm Conditions Disability Benefits Questionnaire)'' in any correspondence. FOR FURTHER...Arm Conditions Disability Benefits Questionnaire).'' SUPPLEMENTARY...

2013-10-31

292

Force production and spatial arm coordination profile in arm crawl swimming in a fixed position.  

Science.gov (United States)

This study analyzed the relationship between mechanical force production and spatial arm position of the swimming movement for each side of the swimmer. Eight internationally recognized male swimmers performed fix positioned arm only swimming with a dynamometer synchronized with underwater cameras. The upper arm positions (? in side, ? in frontal view) and the elbow angles (? in 3D) were determined at the moment where the force production reached the peak (Fmax) and the maximal values of rate of force development (RFDmax). RFDmax and ? values showed significant differences between the sides (Pswimmer. PMID:21138814

Karsai, István; Garrido, N; Louro, H; Leitão, L; Magyar, F; Alves, F; Silva, A

2010-12-01

293

Synthesis, conformational and spectroscopic characterization of monomeric styrene derivatives having pendant p-substituted benzylic ether groups.  

Science.gov (United States)

Three derivatives of styrene monomer, 4-chlorophenyl-4-vinylbenzyl ether (I), 4-methoxyphenyl-4-vinylbenzyl ether (II) and 4-ethylphenyl-4-vinylbenzyl ether (III) were synthesized. The synthesized two novel compounds (I and III) and one with undefined structural features were identified by experimental spectroscopic techniques and density functional approach. The optimized geometrical structure, vibrational and electronic transitions along with chemical shifts of those compounds were presented in this study. The vibrational spectra of investigated compounds were recorded in solid state with FT-IR spectrometry in the range of 4000-400 cm(-1). The computational vibrational wavenumbers and also ground state equilibrium conformations were carried out by using density functional method with 6-311++G(d,p) basis set. Assignments of the fundamental vibrational modes were examined on the basis of the measured data and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. Isotropic chemical shift of hydrogen and carbon nuclei were investigated via observed (1)H and (13)C NMR spectra in deuterated DMSO solution and predicted data applied with gauge-invariant atomic orbitals (GIAOs) method. The UV absorption spectra of monomers were observed in the range of 200-800 nm in ethanol, and time dependent DFT method was used to obtain the electronic properties. A detailed description of spectroscopic behaviors of compound was given based on the comparison of experimental measurements and theoretical computations. PMID:23608133

Cinar, Mehmet; Ozcan, Levent; Karabacak, Mehmet; Erol, Ibrahim

2013-07-01

294

15N-amino acids syntheses  

International Nuclear Information System (INIS)

4 syntheses of 15N-amino acids are presented: (1) ammonolysis of ?-halogenated acids with H15NO3, (2) hydrolysis of hydantoin derivatives using 15NH4HCO3, (3) synthesis with phthalimide-15N potassium and (4) synthesis with acetamino-15N diethyl malonate

295

Syntheses of two stereoselectively trideuteriated vinylcyclopropanes  

International Nuclear Information System (INIS)

An experimental determination of the stereochemistry of the thermal vinylcyclopropane to cyclopentene rearrangement is of some importance. Therefore, the authors have synthesized multigram quantities of methyl 2-cyclopropene-1-carboxylate have been converted in five steps to the syn-E and syn-Z isomers of 2,3,2'-d3-vinylcyclopropane with high levels of deuterium incorporation and steroselectivity. 2 figs

296

Highly Efficient Syntheses of Hyaluronic Acid Oligosaccharides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Highly efficient syntheses of hyaluronic acid oligosaccharides have been accomplished through the pre-activation based iterative one-pot strategy. A series of oligosaccharides ranging from di- to hexasaccharides were rapidly assembled using only near stoichiometric amounts of the building blocks without aglycon adjustment or purifications of intermediate oligosaccharides. Deprote...

Huang, Lijun; Huang, Xuefei

2007-01-01

297

Method and apparatus for synthesizing filamentary structures  

Science.gov (United States)

Method and apparatus for producing filamentary structures. The structures include single-walled nanotubes. The method includes combusting hydrocarbon fuel and oxygen to establish a non-sooting flame and providing an unsupported catalyst to synthesize the filamentary structure in a post-flame region of the flame. Residence time is selected to favor filamentary structure growth.

Height, Murray J. (Somerville, MA); Howard, Jack B. (Winchester, MA); Vandersande, John B. (Newbury, MA)

2008-02-26

298

DECOMPOSER: A Synthesizer for Systolic Systems,  

Science.gov (United States)

A tool for synthesizing systolic systems is introduced. Given a hierarchical specification of the computations to be preformed and hints as to how these computations are to be performed, this tool generates an analysis of the hardware required to do the c...

P. P. Hou, R. M. Owens, M. J. Irwin

1988-01-01

299

Light duty utility arm startup plan  

International Nuclear Information System (INIS)

This plan details the methods and procedures necessary to ensure a safe transition in the operation of the Light Duty Utility Arm (LDUA) System. The steps identified here outline the work scope and identify responsibilities to complete startup, and turnover of the LDUA to Characterization Project Operations (CPO)

300

ARM Surface Meteorology Systems Instrument Handbook  

Energy Technology Data Exchange (ETDEWEB)

The ARM Surface Meteorology Systems consist mainly of conventional in situ sensors that obtain a defined “core” set of measurements. The core set of measurements is: Barometric Pressure (kPa), Temperature (°C), Relative Humidity (%), Arithmetic-Averaged Wind Speed (m/s), Vector-Averaged Wind Speed (m/s), and Vector-Averaged Wind Direction (deg).

Ritsche, MT

2011-03-08

 
 
 
 
301

Light Duty Utility Arm Software Test Plan  

International Nuclear Information System (INIS)

This plan describes how validation testing of the software will be implemented for the integrated control and data acquisition system of the Light Duty Utility Arm System (LDUA). The purpose of LDUA software validation testing is to demonstrate and document that the LDUA software meets its software requirements specification

302

Light duty utility arm software requirements specification  

International Nuclear Information System (INIS)

This document defines the software requirements for the integrated control and data acquisition system of the Light Duty Utility Arm (LDUA) System. It is intended to be used to guide the design of the application software, to be a basis for assessing the application software design, and to establish what is to be tested in the finished application software product

303

Field Campaign Guidelines (ARM Climate Research Facility)  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this document is to establish a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking database tool and are tailored to meet the scope of each specific field campaign.

Voyles, JW

2011-01-17

304

The lure of disarmament and arms reduction  

International Nuclear Information System (INIS)

Nuclear disarmament and arms reduction do not have the same aims. Confusing their definitions means misunderstanding the logic which currently drives the power calculations of yesterday's Great Powers, and their associated approaches to the new strategic actor: China. The author knows the subject well from personal experience. (author)

305

32 CFR 1624.9 - Induction into the Armed Forces.  

Science.gov (United States)

... 6 2010-07-01 2010-07-01 false Induction into the Armed Forces. 1624.9 Section 1624...National Defense SELECTIVE SERVICE SYSTEM INDUCTIONS § 1624.9 Induction into the Armed Forces. Registrants in...

2010-07-01

306

Octopus Uses Two Arms to "Walk Away" from Trouble  

Science.gov (United States)

... Scientists report that certain octopus species use two of their eight arms to walk. Credit and ... octopus species can raise six of their arms and walk backward on the remaining two. Crissy Huffard ...

307

Template Syntheses, Crystal Structures and Supramolecular Assembly of Hexaaza Macrocyclic Copper(II) Complexes  

International Nuclear Information System (INIS)

Two new hexaaza macrocyclic copper(II) complexes were prepared by a template method and structurally characterized. In the solid state, they were self-assembled by intermolecular interactions to form the corresponding supramolecules 1 and 2, respectively. In the structure of 1, the copper(II) macrocycles are bridged by a tp ligand to form a macrocyclic copper(II) dimer. The dimer extends its structure by intermolecular forces such as hydrogen bonds and C-H···? interactions, resulting in the formation of a double stranded 1D supramolecule. In 2, the basic structure is a monomeric copper(II) macrocycle with deprotonated imidazole pendants. An undulated 1D hydrogen bonded array is achieved through hydrogen bonds between imidazole pendants and secondary amines, where the imidazole pendants act as a hydrogen bond acceptor. The 1D hydrogen bonded supramolecular chain is supported by C-H···? interactions between the methyl groups of acetonitrile ligands and imidazole pendants of the copper(II) macrocycles. In both complexes, the introduction of imidazoles to the macrocycle as a pendant plays an important role for the formation of supramolecules, where they act as intermolecular hydrogen bond donors and/or acceptors, C-H···? and ?-? interactions

308

Regional rates of sweat evaporation during leg and arm cycling.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The rate of sweat evaporation from the arm, chest, back and thigh, aural temperature, skin temperature (arm, chest, back and thigh), heat production (derived from measurements of respiratory gas exchange) and heart rate were measured in 7 men during 15 minutes of leg or arm cycling at 32% of predicted maximum oxygen uptake (VO2 max). The regional sweat evaporation rates and changes in body temperature were similar during both forms of exercise. The peak rates of sweat evaporation from the arm...

Ayling, J. H.

1986-01-01

309

Iterative Learning Control of a Flexible Robot Arm Using Accelerometers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Iterative learning control (ILC) is applied to a laboratory scale robot arm with joint flexibility. The ILC algorithm is based on an estimate of the arm angle, where the estimate is formed using measurements of the motor angle and the arm angular acceleration. The design of the ILC algorithm is based on a model obtained from system identification. The ILC algorithm is evaluated experimentally on the robot arm with good results.

Gunnarsson, Svante; Norrlo?f, Mikael; Rahic, Enes; O?zbek, Markus

2003-01-01

310

Mechanistic aspects of the chemistry of mononuclear Cr(III) complexes with pendant-arm macrocyclic ligands and formation of discrete Cr(III)/Fe(II) and Cr(III)/Fe(II)/Co(III) cyano-bridged mixed valence compounds.  

Science.gov (United States)

The kinetics and mechanism of the redox reaction between [Fe(II)(CN)(6)](4-) and the macrocyclic ligand complex [CrClL(15)](2+) (L(15) = 6-methyl-1,4,8,12-tetraazacyclopentadecane-6-amine) has been studied at different pH values. In acidic solution, the expected redox process occurs with no formation of any of the possible Cr(III)/Fe(II) mixed valence complexes, as those seen for the Co(III) species of the same family, due to the enhanced lability of the Cr(II) species formed on Fe(II) to Fe(III) oxidation. In alkaline conditions, the formation of the complex [Cr(L(15))(OH)(2)](+) takes place as an initial step that precedes a simple substitution process producing the expected cyano-bridged Cr(III)/Fe(II) complex. In this species the potentially pentadentate ligand, L(15), has a tetradentate coordination mode with a protonated exocyclic primary amine group and the redox potential is shifted to more negative values, thus disfavouring a redox driven reaction; the equivalent complex [CrCl(HL(14))(H(2)O)](3+) (L(14) = 6-methyl-1,4,8,11-tetraazacyclotetradecane-6-amine) has been prepared by the same method and characterized by X-ray crystallography. The final [Fe(II)(CN)(6)](4-) substituted complex, [{(HL(15))(OH)Cr(III)NC}Fe(II)(CN)(5)](-) shows pK(a) values of 3.8 and 7.4, as expected for the aqua and amino ligands, respectively. Its characterization indicated its Class II mixed valence character with a very intense MMCT band at 350 nm showing a much larger extinction coefficient than that observed for the Co(III) complexes of the same family. This fact is in good agreement with the much larger Cr(III)-Fe(II) (t(2g)-t(2g)) coupling through cyanide bridging ligands expected for these complexes. The fully mixed metal/valence/ligand trimetallic complex [{(HL(15))(OH)Cr(III)NC}{L(13)Co(III)NC}Fe(II)(CN)(4)](2+) has been prepared following the same procedures and the results are comparable. The final complex has the same Class II mixed valence character and its electronic spectrum shows the characteristics of both the Fe(II)-to-Cr(III) and Fe(II)-to-Co(III) CT bands. The study allows the application of the redox and/or substitutionally driven methodology, already described and kinetically designed, for the preparation of discrete mixed valence complexes of inert centres, so avoiding the unpredictable nature of other approaches seen in the past. PMID:19859612

Basallote, Manuel G; Bernhardt, Paul V; Calvet, Teresa; Castillo, Carmen E; Font-Bardia, Mercè; Martínez, Manuel; Rodríguez, Carlos

2009-11-21

311

49 CFR 1562.29 - Armed security officer requirements.  

Science.gov (United States)

...Training. Each armed security officer onboard an aircraft operating into or out of DCA... (1) Each armed security officer onboard an aircraft operating into or out of DCA...substances. An armed security officer onboard an aircraft operating into or out...

2010-10-01

312

49 CFR 234.255 - Gate arm and gate mechanism.  

Science.gov (United States)

...Transportation 4 2010-10-01 2010-10-01 false Gate arm and gate mechanism. 234.255 Section 234.255 Transportation...and Testing Inspections and Tests § 234.255 Gate arm and gate mechanism. (a) Each gate arm and...

2010-10-01

313

Self-Reconfigurable Two-Arm Manipulator With Bracing  

Science.gov (United States)

Proposed two-arm robotic manipulator capable of changing its mechanical structure to fit given task. No reassembly or replacement in conventional sense: instead, arms commanded during operation to assume any of number of alternative configurations, described briefly in "Dynamic Coordination of a Two-Arm Robotic Manipulator" (NPO-18816), NASA Tech Briefs.

Lee, Sukhan; Kim, Sungbok

1994-01-01

314

49 CFR 234.255 - Gate arm and gate mechanism.  

Science.gov (United States)

...2010-10-01 false Gate arm and gate mechanism. 234.255 Section 234.255 Transportation...and Tests § 234.255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each...

2010-10-01

315

Teaching on Science, Technology and the Nuclear Arms Race.  

Science.gov (United States)

Describes a course focusing on science, technology, and the nuclear arms race. Two sample homework exercises and course topics are provided. Topics, with lists of questions that might be addressed, focus on nuclear weapons, alternatives to deterrence, and arms control. Approaches to teaching about the nuclear arms race are also provided. (JN)

Schroeer, Dietrich

1983-01-01

316

78 FR 701 - 36(b)(1) Arms Sales Notification  

Science.gov (United States)

...of a section 36(b)(1) arms sales notification. This is...Section 36(b)(1) of the Arms Export Control Act, as amended...defined in Section 47(6) of the Arms Export Control Act. (iii...Consideration for Purchase: Very Small Aperture Terminal (VSAT)...

2013-01-04

317

The synthesis and activities of novel mononuclear or dinuclear cyclen complexes bearing azole pendants as antibacterial and antifungal agents.  

Science.gov (United States)

A series of novel compounds containing 1,4,7,10-tetraazacyclododecane and azoles were synthesized and characterized by (1)H NMR, MS and elemental analysis. Bioactive assay manifested that some target compounds, such as 11a, 11b and 11d, displayed good and broad spectrum antimicrobial activities with relative low MIC values against most of tested strains. These dinuclear complexes gave comparable or even better antimicrobial efficiencies than the reference drugs Fluconazole and Chloromycin. The result showed that the metal ions were the key factors to enhance the antimicrobial activities for mononuclear or dinuclear complexed in varying degrees. The interaction evaluation of compound 11b with bovine serum albumin (BSA) as an example was tested by fluorescence method. The thermodynamic parameters indicated that the hydrogen bonds and van der waals forces played the major roles in the strong association between dinuclear compound and BSA. The CCK-8 tests also confirmed the safeties of these dinuclear compounds in vitro. PMID:25064345

Li, Shuo; Chen, Jia-Xuan; Xiang, Qing-Xiang; Zhang, Li-Qun; Zhou, Cheng-He; Xie, Jia-Qing; Yu, Lan; Li, Fang-Zhen

2014-09-12

318

Syntheses and studies of organosilicon compounds  

Energy Technology Data Exchange (ETDEWEB)

The syntheses of polycarbosilanes and polysilanes as silicon carbide ceramic precursors have been active research areas in the Barton Research Group. In this thesis, the work is focused on the preparation of polycarbosilanes and polysilanes as stoichiometric silicon carbide precursor polymers. The syntheses of the precursor polymers are discussed and the conversions of these precursors to silicon carbide via pyrolysis are reported. The XRD pattern and elemental analyses of the resulting silicon carbide ceramics are presented. Silicon monoxide is an important intermediate in the production of silicon metal. The existence of silicon monoxide in gap phase has been widely accepted. In the second part of this thesis, the generation of gaseous silicon monoxide in four different reactors and the reactions of gaseous silicon monoxide towards organic compounds are discussed.

Xie, R.

1999-02-12

319

Syntheses and biological evaluation of vinblastine congeners.  

Science.gov (United States)

Sixty-two congeners of vinblastine (VLB), primarily with modifications of the piperidine ring in the carbomethoxycleavamine moiety of the binary alkaloid, were synthesized and evaluated for cytotoxicity against murine L1210 leukemia and RCC-2 rat colon cancer cells, and for their ability to inhibit polymerization of microtubular protein at 10(7) M concentrations was found for L1210 inhibition by these compounds, with the most active 1000x as potent as vinblastine. PMID:12945903

Kuehne, Martin E; Bornmann, William G; Markó, Istvan; Qin, Yong; LeBoulluec, Karen L; Frasier, Deborah A; Xu, Feng; Mulamba, Tshilundu; Ensinger, Carol L; Borman, Linda S; Huot, Anne E; Exon, Christopher; Bizzarro, Fred T; Cheung, Julia B; Bane, Susan L

2003-06-21

320

Porous oxides synthesized by the combustion method  

International Nuclear Information System (INIS)

was studied the morphology of the synthesized materials and the semiquantitative elemental composition. 4. Realization of a sorption experiment type Batch with non radioactive Co2+ to simulate the sorption of 60 Co and determination of the sorption capacity by means of neutron activation of the non radioactive cobalt. 5. Determination of the surface area by the (BET) technique of the inorganic oxides with better sorption properties. (Author)

 
 
 
 
321

Mechanical properties of bacterially synthesized nanocellulose hydrogels  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The mechanical characteristics of bacterially synthesized nano-cellulose (BNC) were studied with uniaxial compression and tensile tests. Compressive loads result in a release of water and the deformation of the water-saturated network corresponds approximately to the volume of released water. The BNC hydrogel exhibits a mainly viscous response under compression. The strain response under tensile loads has an elastic and a viscous component. This can be described with a Maxwell model, where th...

Frensemeier, M.; Koplin, C.; Jaeger, R.; Kramer, F.; Klemm, D.

2010-01-01

322

SYNTHESES OF METHYLENEDIANILINES OVER THE ZEOLITE CATALYSTS  

Directory of Open Access Journals (Sweden)

Full Text Available Syntheses of methylenedianilines over zeolites with various structures were studied. It was foundout that the most selective catalyst for the synthesis of 4,4´-methylenedianiline isomer was zeoliteY. Further, the kinetic data showed that initial N,N´-diphenylmethylenediamine reacted over zeolitecatalysts by even one order of magnitude faster that the intermediate product 4-amino-N-benzylaniline.The most suitable temperature range

Ji?í Trejbal

2010-12-01

323

Synthese und Charakterisierung von molekularen Nanostrukturen  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this thesis, bulk and local scale spectroscopic and microscopic tools have been applied to investigate the purified raw material of SWCNT and synthesized MWBNNT, BN-nanocapsules, B-doped SWCNT and SiC nanostructures. Using bulk scale sensitive techniques, including optical absorption spectroscopy, Raman spectroscopy, high-resolution electron energy-loss spectroscopy, the average response of the whole sample is obtained. On the other hand, on a local scale transmission and scanning electron...

Borowiak-palen, Ewa

2004-01-01

324

Molecular trees: from syntheses towards applications  

International Nuclear Information System (INIS)

Molecular trees, also called dendrimers, arborols, cauliflowers, cascades or hyperbranched molecules, have been synthesized since their first observation in 1978 by divergent, convergent or combined methods, with various functions on the branches. The potential applications of these nanoscopic molecules are in the fields of biology (gene therapy, virus mimicking an vectorization) and molecular materials sciences (new polymers, adhesion, liquid crystals, etc). (authors). 236 refs., 6 figs., 2 tabs., 8 schemes

325

A Global Obstacle-avoidance Map for Anthropomorphic Arms  

Directory of Open Access Journals (Sweden)

Full Text Available More and more humanoid robots are used in human society, and they face a wide variety of complicated manipulation tasks, which are mainly to be achieved by their anthropomorphic arms. Obstacle avoidance for the anthropomorphic arm must be a fundamental consideration to guarantee the successful implementation of these tasks. Different from traditional methods searching for feasible or optimal collision-free solutions for the anthropomorphic arm, a global obstacle- avoidance map for the whole arm is proposed to indicate the complete set of feasible solutions. In this map, the motion of the arm can be appropriately planned to intuitively control the configuration of the arm in motion. First, the cubic spline function is adopted to interpolate some well-chosen path points to generate a smooth collision-free path for the wrist of the anthropomorphic arm. Second, based on the path function of the wrist, the time and the self-rotation angle of the arm about the “shoulder-wrist” axis are used to parameterize all possible configurations of the arm so that a global two- dimensional map considering the obstacle avoidance can be established. Subsequently, a collision-free self-rotation angle profile of the arm can be well planned. Finally, the joint trajectories of a specific anthropomorphic arm, which correspond to the planned path of the wrist and self-rotation angle profile of the arm, can be solved on the basis of the general kinematic analysis of the anthropomorphic arm, and the specific structure. Several simulations are conducted to verify that the proposed collision-free motion planning method for anthropomorphic arms has some advantages and can be regarded as a convenient and intuitive tool to control the configuration of the anthropomorphic arm in motion, without collision with obstacles in its surroundings.

Cheng Fang

2014-07-01

326

A Synthesizer based on square waves  

CERN Document Server

One of the most widely employed technique for the sound synthesis is based on the Fourier theorem that states that any signal can be obtained as a sum of sinusoids. Unfortunately this algorithm, when applied to synthesizers, requires some peculiar operations, as the addressing of a Look Up Table, that are not easily built-in in standard processors, thus requiring specially designed architectures. The aim of this paper is to show that, when using a new method for the analysis and polar coordinates, a much broader class of functions can be employed as a basis, and it turns out that the square wave is just one of such functions. When the synthesis of signals is carried out by summing square waves, the additive synthesizer architecture results much more simplified, allowing for example to synthesize complex signals simply in software, using general purpose microprocessors, even in real-time. Firstly it will be proven that when using a novel method for the analysis phase, the L2 function space admits a broad class...

Vergara, Sossio

2008-01-01

327

Syntheses and studies of acetylenic polymers  

Energy Technology Data Exchange (ETDEWEB)

Based on new diiodo aryl compounds a series of novel soluble polymers, poly(2,5-dialkoxy-1,4-phenyleneethynylene)s (PPE polymers) were synthesized using palladium-catalysis. The molecular weights (MW) range from 8,000 to 40,000. Properties such as absorption, fluorescence, and conductivity were studied. A PPE polymer with butoxy side chain exhibits a weak electrical conductivity ({sigma} = 10{sup {minus}3} S/cm) after doping with AsF{sub 5}. Absorption spectra in THF solution at room temperature (RT) show a maximum at 440 nm. However, absorption spectra of PPE polymers in the film state at (RT) show a maximum at 480 nm. PPE polymer-based light emitting diode (LED) devices have been prepared; greenish light from these LED devices can be observed. Poly(ethynylene-p-arylene-ethynylene-silylene)s were synthesized through the same palladium-catalyzed polymerization; MWs are between 6,000 and 82,000. Absorption and fluorescence were studied. Some of these polymers exhibit thermotropic liquid crystalline properties. In addition, nonlinear optical properties were briefly examined. Poly(silylene-ethynylene) homopolymers as well as alternating copolymers were synthesized through a novel palladium-catalyzed polymerization; MWs range from 56 {times} 10{sup 3} to 5.3 {times} 10{sup 3}. Thermal stability of these was also investigated; char yields range from 56 to 83%. One of these polymers exhibits thermotropic liquid crystalline properties.

Yiwei, Ding

1994-03-03

328

Magnesioferrite synthesized from magnesian-magnetites  

Directory of Open Access Journals (Sweden)

Full Text Available Magnesioferrite is an important mineral due to its use in different scientific fields and by the fact that the soil through the action of weathering, can be a source of nutrients essential for plant development by the fact that in the soil. Its use in pure form or associated with other minerals is only possible through the synthesis in laboratory conditions. This study aimed to synthesize magnesioferrite and hematite from magnesian-magnetite by a co-precipitation procedure. The methodology used is an adaptation of the method of synthesis of pure magnetite, partially replacing the soluble salts of iron with soluble magnesium salts in the proportion of 30.0 mol% of Fe for Mg. The characterization of the synthetic minerals used x-rays diffraction, total chemical analysis and mass specific magnetic susceptibility. The results showed that besides the magnesian-magnetite an unprecedented muskoxita was synthesized, which upon annealing was converted to magnesioferrite and hematite and in the proportion of 93.1% and 6.9% respectively. The isomorphous substitution of Fe for Mg enhanced the thermal stability of the ferrimagnetic mineral synthesized.

Marcelo Hidemassa Anami

2014-02-01

329

Thermoelectric n-type silicon germanium synthesized by unidirectional solidification in microgravity  

International Nuclear Information System (INIS)

Highlights: ? Thermoelectric n-type SiGe was synthesized by unidirectional solidification. ? SiGe had dendrite structure aligned along the solidification direction. ? SiGe solidified unidirectionally in microgravity had crystalline orientation. ? Anisotropy of electric conductivity was seen in orthogonal solidification directions. ? ZT of Si0.7Ge0.3-1at%P solidified in microgravity at 1000 K was 1.19. - Abstract: Thermoelectric n-type Si0.2Ge0.8 and Si0.7Ge0.3 added 1at%P for Si–Ge were synthesized by unidirectional solidification in microgravity. Microgravity with ±10?2 g for 0.46 s was obtained in free fall using a 2 m-drop tower. The microstructure of the sample solidified in microgravity and 1 g was dendrite on the surface that contacted a Cu chill block. The microstructure of the cross section along the cooling direction was dendrite and the columnar dendrite structure was mainly aligned along the solidification direction. The dendrite became larger with depth from the surface that contacted the Cu chill block, and the width of the primary dendrite arm solidified in microgravity exceeded that in 1 g. Ge was segregated to the secondary arm of columnar dendrite. The Si/Ge atomic ratio in the primary and secondary arm of Si0.7Ge0.3-1at%P solidified in 1 g and microgravity was slightly higher than that of solidified Si0.8Ge0.2-1at%P in 1 g and microgravity. The secondary arm of solidified Si0.7Ge0.3-1at%P was wider than that of solidified Si0.8Ge0.2-1at%P. P was distributed uniformly in Si–Ge solidified in microgravity. The electrical conductivities of Si0.8Ge0.2-1at%P and Si0.7Ge0.3-1at%P were anisotropic in directions along and perpendicular to the solidification direction. The dimensionless Figure of Merit, ZT, of the direction along the solidification direction at 1000 K was estimated from thermal conductivity, electrical conductivity adjusted by the anisotropy, and the Seebeck coefficient in 1 g and microgravity. The ZT of the sample solidified in microgravity at 1000 K along the solidification direction was 1.19.

330

Cardiopulmonary exercise testing: arm crank vs cycle ergometry.  

Science.gov (United States)

This pilot study compared oxygen consumption during arm crank and cycle ergometer tests in 15 women. The mean (SD) peak oxygen consumption was less with arm cranking (25 (5) ml.kg(-1) .min(-1)) than with cycling (40 (7) ml.kg(-1) .min(-1)), p arm cranking (13 (2) ml.kg(-1) .min(-1)) than with cycling (20 (4) ml.kg(-1) .min(-1)), p arm and leg exercise, p = 0.0007. This study suggests that arm crank cardiopulmonary exercise testing could be used for pre-operative assessment in those unable to cycle. PMID:23573845

Orr, J L; Williamson, P; Anderson, W; Ross, R; McCafferty, S; Fettes, P

2013-05-01

331

The Norma Arm Region Chandra Survey Catalog: X-Ray Populations in the Spiral Arms  

Science.gov (United States)

We present a catalog of 1415 X-ray sources identified in the Norma Arm Region Chandra Survey (NARCS), which covers a 2° × 0.°8 region in the direction of the Norma spiral arm to a depth of ?20 ks. Of these sources, 1130 are point-like sources detected with >=3? confidence in at least one of three energy bands (0.5-10, 0.5-2, and 2-10 keV), five have extended emission, and the remainder are detected at low significance. Since most sources have too few counts to permit individual classification, they are divided into five spectral groups defined by their quantile properties. We analyze stacked spectra of X-ray sources within each group, in conjunction with their fluxes, variability, and infrared counterparts, to identify the dominant populations in our survey. We find that ~50% of our sources are foreground sources located within 1-2 kpc, which is consistent with expectations from previous surveys. Approximately 20% of sources are likely located in the proximity of the Scutum-Crux and near Norma arm, while 30% are more distant, in the proximity of the far Norma arm or beyond. We argue that a mixture of magnetic and nonmagnetic cataclysmic variables dominates the Scutum-Crux and near Norma arms, while intermediate polars and high-mass stars (isolated or in binaries) dominate the far Norma arm. We also present the cumulative number count distribution for sources in our survey that are detected in the hard energy band. A population of very hard sources in the vicinity of the far Norma arm and active galactic nuclei dominate the hard X-ray emission down to fX ? 10–14 erg cm–2 s–1, but the distribution curve flattens at fainter fluxes. We find good agreement between the observed distribution and predictions based on other surveys.

Fornasini, Francesca M.; Tomsick, John A.; Bodaghee, Arash; Krivonos, Roman A.; An, Hongjun; Rahoui, Farid; Gotthelf, Eric V.; Bauer, Franz E.; Stern, Daniel

2014-12-01

332

Dual arm robotic system with sensory input  

Science.gov (United States)

The need for dual arm robots in space station assembly and satellite maintainance is of increasing significance. Such robots will be in greater demand in the future when numerous tasks will be assigned to them to relieve the direct intervention of humans in space. Technological demands from these robots will be high. They will be expected to perform high speed tasks with a certain degree of autonomy. Various levels of sensing will have to be used in a sophisticated control scheme. Ongoing research in control, sensing and real-time software to produce a two-arm robotic system than can accomplish generic assembly tasks is discussed. The control hierarchy and the specific control approach are discussed. A decentralized implementation of model-reference adaptive control using Variable Structure controllers and the incorporation of tactile feedback is considered.

Ozguner, U.

1987-01-01

333

MAGIC: Marine ARM GPCI Investigation of Clouds  

Energy Technology Data Exchange (ETDEWEB)

The second Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF2) will be deployed aboard the Horizon Lines cargo container ship merchant vessel (M/V) Spirit for MAGIC, the Marine ARM GPCI1 Investigation of Clouds. The Spirit will traverse the route between Los Angeles, California, and Honolulu, Hawaii, from October 2012 through September 2013 (except for a few months in the middle of this time period when the ship will be in dry dock). During this field campaign, AMF2 will observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. There will also be two intensive observational periods (IOPs), one in January 2013 and one in July 2013, during which more detailed measurements of the atmospheric structure will be made.

Lewis, ER; Wiscombe, WJ; Albrecht, BA; Bland, GL; Flagg, CN; Klein, SA; Kollias, P; Mace, G; Reynolds, RM; Schwartz, SE; Siebesma, AP; Teixeira, J; Wood, R; Zhang, M

2012-10-03

334

Implementation of Multilayer AHB Busmatrix for ARM  

Directory of Open Access Journals (Sweden)

Full Text Available The multi-layer AHB busmatrix (ML-AHBbusmatrix proposed by ARM is a highly efficient on chip bus thatallows parallel access paths between multiple masters and slavesin a system. However, the ML-AHB busmatrix of ARM offers onlytransfer-based fixed-priority and round-robin arbitrationschemes. In this paper, we present one way to improve the arbiterimplementation of the ML-AHB busmatrix. The proposed arbiter,which is Self-motivated (SM, selects one of the nine possiblearbitration schemes based upon the priority-level and the desiredtransfer length from the masters so that arbitration leads to themaximum performance.Our SM arbitration scheme has the following advantages: 1 Itcan adjust the processed data unit; 2 it changes the prioritypolicies during runtime; and 3 it is easy to tune the arbitrationscheme according to the characteristics of the target application.

E. Raja

2011-11-01

335

Parametric instabilities in the LCGT arm cavity  

International Nuclear Information System (INIS)

We evaluated the parametric instabilities of LCGT (Japanese interferometric gravitational wave detector project) arm cavity. The number of unstable modes of LCGT is 10-times smaller than that of Advanced LIGO (USA). Since the strength of the instabilities of LCGT depends on the mirror curvature more weakly than that of Advanced LIGO, the requirement of the mirror curvature accuracy is easier to be achieved. The difference in the parametric instabilities between LCGT and Advanced LIGO is because of the thermal noise reduction methods (LCGT, cooling sapphire mirrors; Advanced LIGO, fused silica mirrors with larger laser beams), which are the main strategies of the projects. Elastic Q reduction by the barrel surface (0.2 mm thickness Ta2O5) coating is effective to suppress instabilities in the LCGT arm cavity. Therefore, the cryogenic interferometer is a smart solution for the parametric instabilities in addition to thermal noise and thermal lensing

336

Embedded Ethernet Controller using ARM LPC2138  

Directory of Open Access Journals (Sweden)

Full Text Available — With the development of network technology and communication technology needs that industrial control can be completed via network has become a trend. Here the proposed system consists of an ARM processor LPC2148 with an external Ethernet interface controller WIZ810MJ and the whole system can function as a web server. In the system the data can be transmitted transparently between host and serial device. The host can communicate with any serial device connected Ethernet without knowing each other’s physical location. Since ARM processor has fast execution capability and Ethernet standard can provide internet access with reasonable speed, this system is suitable for enhancing security in industrial conditions by remotely monitoring various industrial appliances where high safety and care is a necessity. There is no doubt that this system will be useful for a wide variety of industrial applications.

S.P.Magadum

2013-05-01

337

Diversity in the Danish Armed Forces  

DEFF Research Database (Denmark)

The Danish Armed Forces face the functional imperative of becoming a smaller, professional expeditionary force and the societal imperative of including women and ethnic minorities. It currently lags behind its NATO partners in gender and ethnic diversity. Lessons to be learned from NATO members with more diverse militaries, such as the United States, Great Britain, and Canada, include recognition of diversity as a societal imperative to sustain the legitimacy of the armed forces, the necessity of systematically collecting and reporting personnel data to guide policy, the necessity of patience and realistic goals, systematically developing recruitment, development, and retention policies, and the superiority of an all-volunteer force over conscription in fulfilling this societal imperative.

Schaub Jr, Gary John; Pradhan-Blach, Flemming

2012-01-01

338

Parametric instabilities in the LCGT arm cavity  

CERN Document Server

We evaluated the parametric instabilities of LCGT (Japanese interferometric gravitational wave detector project) arm cavity. The number of unstable modes of LCGT is 10-times smaller than that of Advanced LIGO (U.S.A.). Since the strength of the instabilities of LCGT depends on the mirror curvature more weakly than that of Advanced LIGO, the requirement of the mirror curvature accuracy is easier to be achieved. The difference in the parametric instabilities between LCGT and Advanced LIGO is because of the thermal noise reduction methods (LCGT, cooling sapphire mirrors; Advanced LIGO, fused silica mirrors with larger laser beams), which are the main strategies of the projects. Elastic Q reduction by the barrel surface (0.2 mm thickness Ta$_2$O$_5$) coating is effective to suppress instabilities in the LCGT arm cavity. Therefore, the cryogenic interferometer is a smart solution for the parametric instabilities in addition to thermal noise and thermal lensing.

Yamamoto, K; Miyoki, S; Ohashi, M; Kuroda, K; Numata, K

2008-01-01

339

Diaminoalkane as Spacer Arm between Polystyrene and ?- Cylodextrin in Affinity Chromatography for ?-Amylase Separation  

Directory of Open Access Journals (Sweden)

Full Text Available Stationary phase design in affinity chromatography has to fulfill at least two requirements: non-specific interaction between solid support and or spacer arm and protein target or others is minimal and specific interaction between ligand and protein target is maximal. In this study, stationary phases that consist of polystyrene (PS as solid support, diaminoalkane as spacer arm and with and without ?CD as a ligand are performed in ?-amylase separation. Therefore, the research was carried out in two steps; stationary phase preparation and adsorption parameter determination towards ?-amylase. Stationary phases that consist of PS, 1,6-diaminohexane and ?CD (PS–DAH–?CD and without ?CD (PS–DAH were synthesized. Stationary phase structure was confirmed by FTIR, 13C NMR solid, 13C dan 1H NMR liquid spectroscopy. Other stationary phases, PS–DAP–?CD and PS–DAP that consist of 1,2-diaminopropane (DAP as spacer arm was synthesized in the previous research. Dynamic ?-amylase adsorption isotherm on PS–DAP and PS–DAH shows that both of them did not fix any adsorption isotherm model. The average binding capacity are 0.071 and 0.31 mg/0.1 g resin, respectively. In another hand, PS–DAP–?CD and PS–DAH–?CD fix isotherm adsorption Langmuir model and the adsorption parameters; the maximum binding capacity (qm are 5.5 and 2.1 mg/0.1 g resin, adsorption equilibrium constant (KA are 0.01965 and 0.01925 ?L—1 and desorption rate constant (k2 are 0.201 and 0.774 mg s—1 , respectively. Due to adsorption parameters, PS–DAP–?CD offer the best adsorption capacity and selectivity as stationary phase in affinity chromatography for ?-amylase separation.

Sri Widarti* ,

2014-02-01

340

Constrained trajectory optimization for kinematically redundant arms  

Science.gov (United States)

Two velocity optimization schemes for resolving redundant joint configurations are compared. The Extended Moore-Penrose Technique minimizes the joint velocities and avoids obstacles indirectly by adjoining a cost gradient to the solution. A new method can incorporate inequality constraints directly to avoid obstacles and singularities in the workspace. A four-link arm example is used to illustrate singularity avoidance while tracking desired end-effector paths.

Carignan, Craig R.; Tarrant, Janice M.

1990-01-01

 
 
 
 
341

Future combat systems armed robotic vehicle  

Science.gov (United States)

The Armed Robotic Vehicle (ARV) is a medium unmanned ground vehicle with semi-autonomous and operator-controlled capability. Two different variants provide Intelligence, Surveillance, Reconnaissance/Target Acquisition (ISR/TA) and direct/indirect fires in support of mounted and dismounted operations. This paper will describe the current system engineering studies proceeding on the ARV and provide insight into key characteristics of the ARV concept.

Larson, John C.; McTamaney, Lou

2004-09-01

342

JPRS report: Arms control, [February 12, 1991  

Energy Technology Data Exchange (ETDEWEB)

This report contains translations/transcriptions of articles and/or broadcasts on arms control. Titles include: Foreign Minister Opens Regional Disarmament Workshop; North Korea Heavily Involved in Missile Production; Ministry Spokesman on Soviet Troop Withdrawal; Foreign Minister on Soviet Troops, Baltics; Soviet Role in Iraqi Scud Acquisition Viewed; Churkin on Comprehensive Test Ban, New York Conference; GDR Supported Iraq`s Chemical Weapons Armament; and others.

NONE

1991-02-12

343

Multi-Armed Bandits in Metric Spaces  

CERN Document Server

In a multi-armed bandit problem, an online algorithm chooses from a set of strategies in a sequence of trials so as to maximize the total payoff of the chosen strategies. While the performance of bandit algorithms with a small finite strategy set is quite well understood, bandit problems with large strategy sets are still a topic of very active investigation, motivated by practical applications such as online auctions and web advertisement. The goal of such research is to identify broad and natural classes of strategy sets and payoff functions which enable the design of efficient solutions. In this work we study a very general setting for the multi-armed bandit problem in which the strategies form a metric space, and the payoff function satisfies a Lipschitz condition with respect to the metric. We refer to this problem as the "Lipschitz MAB problem". We present a complete solution for the multi-armed problem in this setting. That is, for every metric space (L,X) we define an isometry invariant which bounds f...

Kleinberg, Robert; Upfal, Eli

2008-01-01

344

Large LED Display Design using ARM9  

Directory of Open Access Journals (Sweden)

Full Text Available LED displays are widely employed for advertisements, sports, transportation, Stock markets, traffic signs in public transportation systems, shopping malls, schools, railways etc., The conventional LED display system uses traditional microcontrollers so that many problems such as poor reliability, flickering and more hardware requirement can be seen in display system. This article presents an efficient architecture for controlling LED displays which has the ability to expose monochrome movies and animations. Implementing the LED display screen using 32-bit ARM9 (S3C2440 processor reduces the hardware requirement and also provide the speed of refreshing the screen will be high so that we can avoid the flickering in the display. In this article, a new way is implemented to increase the speed of the monochrome display is by scanning 8 rows at a time(row byte scanning rather than single row(pixel by pixel. Therefore, the speed of refreshing of LED display will be increased. By allowing constant current through the LEDs in the display will increase the reliability of the display. The 8 GPIO lines of ARM processor are connected to the 8 rows of the LED display via 8 bit latches connected to implement row-byte scanning. Unlike in traditional LED display, rather than many microcontrollers a single ARM processor is enough to refresh the screen. A software tool using JAVA is present in PC to draw animations and send it to the LED display.

Sweta G, K Satyashree

2011-08-01

345

Landsat observations in support of ARM  

Energy Technology Data Exchange (ETDEWEB)

Compare results from state-of-the-art 3D radiative transfer techniques on a variety of input cloud fields with a wide degree of complexity. The goal of this proposal is to compare results from state-of-the-art 3D radiative transfer techniques on a variety of input cloud fields with a wide degree of complexity. This effort will complement ongoing cloud-related efforts of the GCSS working groups, and DoE-ARM Single Column Modeling and Cloud working groups. The intercomparison will be beneficial in delineating the limits and merits of the various approaches currently used to treat 3D radiative transfer theory and will create a broader consensus on what are the most serious remote sensing errors due to 3D effects. Realistic cloud water distributions used as input for many of the experiments will come directly from the ARM archive or from ARM-related modeling activities (such as those in progress as part of GCSS).

Cahalan, R.

2003-06-04

346

ARM9 Based Navigation System for Vehicles  

Directory of Open Access Journals (Sweden)

Full Text Available Vehicle Navigation System is one of the most challenging works today. If any accidents happen then if we know nearest hospital, route to reach hospital then we can have more chance to rescue people. Our project is an attempt to develop Vehicle Navigation System using ARM9 Processor, GPS and Electronic Compass. Usage of our project can be to guide the sailor in ocean, guide tourists and guide taxi drivers in major and metropolitan cities. Here using the ARM processor and the embedded operating system WindowsCE as a development platform for designing navigation systems. The system uses GPS systems to obtain the latitude and longitude of the vehicles, by conversion and map-matching to get the actual location on the map, and then the user enter the destination, calculated the shortest path by A* shortest path algorithm and showed on the ARM processor. At the same time, direct of vehicle is extracted from electronic compass providing the direction of vehicle and displayed on the screen.

S. Lokesh*1,

2014-05-01

347

Continuum robot arms inspired by cephalopods  

Science.gov (United States)

In this paper, we describe our recent results in the development of a new class of soft, continuous backbone ("continuum") robot manipulators. Our work is strongly motivated by the dexterous appendages found in cephalopods, particularly the arms and suckers of octopus, and the arms and tentacles of squid. Our ongoing investigation of these animals reveals interesting and unexpected functional aspects of their structure and behavior. The arrangement and dynamic operation of muscles and connective tissue observed in the arms of a variety of octopus species motivate the underlying design approach for our soft manipulators. These artificial manipulators feature biomimetic actuators, including artificial muscles based on both electro-active polymers (EAP) and pneumatic (McKibben) muscles. They feature a "clean" continuous backbone design, redundant degrees of freedom, and exhibit significant compliance that provides novel operational capacities during environmental interaction and object manipulation. The unusual compliance and redundant degrees of freedom provide strong potential for application to delicate tasks in cluttered and/or unstructured environments. Our aim is to endow these compliant robotic mechanisms with the diverse and dexterous grasping behavior observed in octopuses. To this end, we are conducting fundamental research into the manipulation tactics, sensory biology, and neural control of octopuses. This work in turn leads to novel approaches to motion planning and operator interfaces for the robots. The paper describes the above efforts, along with the results of our development of a series of continuum tentacle-like robots, demonstrating the unique abilities of biologically-inspired design.

Walker, Ian D.; Dawson, Darren M.; Flash, Tamar; Grasso, Frank W.; Hanlon, Roger T.; Hochner, Binyamin; Kier, William M.; Pagano, Christopher C.; Rahn, Christopher D.; Zhang, Qiming M.

2005-05-01

348

Humanoid Robot Arm Adaptive Control: Experimental Implementation  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, a partially model based adaptive control of humanoid robot arm is presented. The aim of the adaptive control scheme is to deal with the uncertain parameters in its own dynamic model such as link masses or actuators inertias as well as to cope with changing dynamics in the tasks like passing objects between a human and a robot. The main idea here is to derive a dynamic model of the robot’s arm via a software package and parameterized it. Then, employ the adaptive control scheme to identify uncertain parameters such as link masses and actuator inertias online. This scheme will also be suitable for the tasks where robot is lifting weight and or passing an object to a human or vice versa (which is the ultimate goal of this work. The adaptive scheme is simulated and experimentally tested on the Bristol Robotics Laboratory humanoid Bristol- Elumotion-Robot-Torso (BERT Arm. Humanoid BERT robot is developed as a collaboration between Bristol Robotics Laboratory and Elumotion (a Bristol based robotic company.

Said G. Khan

2014-01-01

349

Small change in structure leads to large difference in protein photocleavage: two porphyrins bearing rhodanine-based pendants.  

Science.gov (United States)

Two 5,10,15,20-tetraphenylporphyrins with one phenyl group anchored to a rhodanine-terminated side chain, RhD-TPP and RhDCOOH-TPP, were designed and synthesized, and their protein photocleavage activities were investigated using bovine serum albumin (BSA) as a model protein. Both porphyrins exhibit similar absorption spectra, fluorescence spectra, fluorescence quantum yields, and singlet oxygen ((1)O(2)) quantum yields in organic solvents due to their structure similarity. They also show similar binding affinities and binding sites toward BSA. However, RhD-TPP is nearly inactive in protein photocleavage while RhDCOOH-TPP can lead to distinct photocleavage of BSA under the same experimental conditions. Such a difference may be attributed to the different binding modes of the two porphyrin derivatives toward BSA, though the apparent binding affinities and the binding sites are similar, and consequently a great difference in the (1)O(2) quantum yields of the two porphyrins bound on BSA. The presence of the COOH group in RhDCOOH is proposed to play an important role, leading to less hydrophobic character and additional interactions towards BSA. PMID:22327540

Jiang, Guo-Yu; Lei, Wan-Hua; Zhou, Qian-Xiong; Hou, Yuan-Jun; Wang, Xue-Song

2012-04-01

350

New LED in synthesized InP  

International Nuclear Information System (INIS)

This paper discusses new light emitting diodes at 1.00 ?m obtained from synthesized InP:Yb bulk crystal. The n-type Yb doped bulk material was grown by gradient freeze method. Mg+ ions were implanted in this material for p-type layer. The in depth localization of the junction is not critical. Photoluminescence and electroluminescence spectra are performed from 77 K to 300 K. Two peaks are observed : band edge emission (0.88 ?m) and intra shell 4f-4f for Yb ions. The 40 times higher than band edge emission. No influence of temperature is observed on Yb3+ peak linewidth and wavelength

351

Biocompatibility of poly allylamine synthesized by plasma  

International Nuclear Information System (INIS)

A study of the electric and hydrophilic properties of poly allylamine (PAI) synthesized by plasma whose structure contains N-H, C-H, C-O and O-H bonds is presented, that promote the biocompatibility with the human body. To study the PAI hydrolytic affinity, solutions of salt concentration similar to those of the human body were used. The results indicate that the solutions modify the charge balance in the surfaces reducing the hydrophobicity in the poly allylamine whose contact angle oscillates among 10 and 16 degrees and the liquid-solid surface tension between 4 and 8 dina/cm. (Author)

352

A new approach to synthesize nano WC  

Science.gov (United States)

Tungsten carbide (WC) is extensively used in cutting and mining tools, dies and in wear resistance parts. The recent application of WC as electrocatalyst in fuel cells to replace costly nobel metal platinum (Pt) has further increased its demand. Its catalytic and mechanical properties are improved with the reduction of particle size in a nanometric range. The nano WC is synthesized from the pure precursor(s) which makes its production costly. In this work, we report a new process to get nano WC directly from the scheelite (CaWO4) ore. The powders were characterized by XRD, SEM and HRTEM.

Singh, Harjinder; Pandey, O. P.

2013-06-01

353

Synthesis of poly(p-phenylene-vinylene) derivatives containing an oxadiazole pendant group and their applications to organic electronic devices.  

Science.gov (United States)

Poly(p-phenylene vinylene) (PPV) derivatives with 2,5-diphenyl-1,3,4-oxadiazole-diyl (OXD) as the side chain, poly[2-{4-[5-(4-(heptyloxy)phenyl)-1,3,4-oxadiazole-2-yI]phenyl-oxy}-1,4-phenylene-vinylene] (OXH-PPV), poly[2-{4-[5-(4-(heptyloxy)phenyl)-1,3,4-oxadia-zole-2-yl]phenyl-oxy}-1,4-phenylenevinylene-co-2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (OXH-PPV-co-MEH-PPV), and poly[2-methoxy-5-(2'-ethylhexyl-oxy)-p-phenylene vinylene] (MEH-PPV), were synthesized via a modified Gilch route. The electron-deficient oxadiazole moiety was introduced on the side chain of the polymer backbone to increase the electron-affinity of the polymers. The electroluminescent (EL) properties of the resulting polymers as an active layer, were investigated by the fabrication of single-layer LEDs and the devices using OXH-PPV-co-MEH-PPV showed better EL properties than those using pure MEH-PPV. Also, to investigate the switching properties of the resulting polymers as an active layer, OFET devices were fabricated in a top-contact/bottom-gate configuration. The resulting FETs exhibited typical p-channel characteristics, field-effect mobility of 6.5 x 10(-4) - 7.0 x 10(-5) cm2 V(-1) s(-1), and on-off ratio of about 10(4)-10(5). PMID:23858852

Lee, Hyemi; Vak, Doojin; Baeg, Kang-Jun; Nah, Yoon-Chae; Kim, Dong-Yu; Noh, Yong-Young

2013-05-01

354

Génotypage du virus de la rougeole par PCR en temps réel: Cas des souches virales isolées au Maroc pendant la saison 2004-2005  

Directory of Open Access Journals (Sweden)

Full Text Available Le génotypage du virus de la rougeole (VR est un outil important dans la surveillance de la rougeole. Il permet d’identifier l’origine du virus, ses voies de transmission et d’évaluer les programmes de vaccination. Vu l’importance du génotypage du VR dans le programme de l’élimination de la rougeole, une technique rapide a été développée. Cette technique se base sur l’identification des génotypes par PCR en temps réel, les différents génotypes sont distingués par leur température de fusion (Tm. Cette méthode constitue une alternative efficace pour l’investigation des épidémies de rougeole dans les pays en phase d’élimination.Les souches du virus de la rougeole isolées pendant la saison 2004-2005 ont été identifiées par PCR en temps réel puis confirmées par le séquençage des gènes H et N. cette étude, a permis de montrer une rapide diversification des génotypes qui circulent au Maroc. Parmi ces génotypes, certains sont importés de l’Afrique de l’Ouest et de l’Europe, d’autres correspondent à la souche autochtone. Ces résultats montrent la nécessité de renforcer la couverture vaccinale et d’introduire une nouvelle stratégie de vaccination dans le but d’éliminer la maladie.

Diane Waku-Kouomou

2007-04-01

355

Chiral 3,3?-disubstituted BINOL derivatives: Syntheses, characterizations and X-ray structure analyses  

Science.gov (United States)

Two chiral 3,3'-disubstituted BINOL derivatives 3a and 3b have been synthesized and their crystal structures have been reported. Their direct evidence of the solid-state conformations and their structural details of the unique 2D supramolecular architectures have been obtained. The intramolecular hydrogen bonds of both compounds lock two substituents at 3,3'-positions (like two arms) towards exterior around naphthyl backbones in an extended conformations. In the ( R)- 3a crystals, the uniform hand-to-hand intermolecular hydrogen bonds of O sbnd H sbnd N link the adjacent molecules into the infinite chainlike structure, and the ?-? stacking interactions and the inter-aggregate Cl/Cl close connections result in forming the higher-order 2D supramolecular crossbedded self-adhesive architecture. For ( R)- 3b, the structural characteristics of the self-assembly is to form supramolecular crossbedded self-adhesive structure through the cooperative hydrogen bonding.

Liu, Guo-Hua; Xue, Yun-Ning; Yao, Mei; Fang, Hai-Bing; Yu, Han; Yang, Shi-Ping

2008-03-01

356

Controlled synthesis of multi-arm star polyether-polycarbonate polyols based on propylene oxide and CO2.  

Science.gov (United States)

Multi-arm star copolymers based on a hyperbranched poly(propylene oxide) polyether-polyol (hbPPO) as a core and poly(propylene carbonate) (PPC) arms are synthesized in two steps from propylene oxide (PO), a small amount of glycidol and CO2 . The PPC arms are prepared via carbon dioxide (CO2 )/PO copolymerization, using hbPPO as a multifunctional macroinitiator and the (R,R)-(salcy)CoOBzF5 catalyst. Star copolymers with 14 and 28 PPC arms, respectively, and controlled molecular weights in the range of 2700-8800 g mol(-1) are prepared (Mw /Mn = 1.23-1.61). Thermal analysis reveals lowered glass transition temperatures in the range of -8 to 10 °C for the PPC star polymers compared with linear PPC, which is due to the influence of the flexible polyether core. Successful conversion of the terminal hydroxyl groups with phenylisocyanate demonstrates the potential of the polycarbonate polyols for polyurethane synthesis. PMID:24214125

Hilf, Jeannette; Schulze, Patricia; Seiwert, Jan; Frey, Holger

2014-01-01

357

Syntheses and radiobrominations of some trimethylsilylphenethylamines  

Energy Technology Data Exchange (ETDEWEB)

Studies of the applications of arylsilane intermediates to radiobrominations have continued with the syntheses of four trimethylsilyl(TMS) substituted phenethylamines. Initial radiobromination studies have involved the nonprotected amines to determine if the ipso electrophilic substitution reactions would occur prior to reaction of the halogen with the amine. Indeed, radiobrominations of 1,2,and4 using carrier-added bromine-77 and stoichiometric amounts of N-chlorosuccinimide (NCS) gave the desired products in good yields. Radiobrominations of 3 under identical reaction conditions yielded a product which was consistent with compound 9 by chromatographic and spectroscopic analyses. When the oxidizing agent was used in excess of bromide ion, a significant amount of a more lipophlic radiobrominated compound was also observed by radio HPLC. The lipophilic compound was the major product when t-BuOCl was used as the oxidant, but was only a minor product when NCS was used. The syntheses of the phenethylamines, 1-8, was accomplished via standard methods (e.g. Knoevenagel Reaction), and is described.

Wilbur, D.S.

1984-01-01

358

Syntheses and radiobrominations of some trimethylsilylphenethylamines  

International Nuclear Information System (INIS)

Studies of the applications of arylsilane intermediates to radiobrominations have continued with the syntheses of four trimethylsilyl(TMS) substituted phenethylamines. Initial radiobromination studies have involved the nonprotected amines to determine if the ipso electrophilic substitution reactions would occur prior to reaction of the halogen with the amine. Indeed, radiobrominations of 1,2,and4 using carrier-added bromine-77 and stoichiometric amounts of N-chlorosuccinimide (NCS) gave the desired products in good yields. Radiobrominations of 3 under identical reaction conditions yielded a product which was consistent with compound 9 by chromatographic and spectroscopic analyses. When the oxidizing agent was used in excess of bromide ion, a significant amount of a more lipophlic radiobrominated compound was also observed by radio HPLC. The lipophilic compound was the major product when t-BuOCl was used as the oxidant, but was only a minor product when NCS was used. The syntheses of the phenethylamines, 1-8, was accomplished via standard methods (e.g. Knoevenagel Reaction), and is described

359

Recent advances in chemoenzymatic peptide syntheses.  

Science.gov (United States)

Chemoenzymatic peptide synthesis is the hydrolase-catalyzed stereoselective formation of peptide bonds. It is a clean and mild procedure, unlike conventional chemical synthesis, which involves complicated and laborious protection-deprotection procedures and harsh reaction conditions. The chemoenzymatic approach has been utilized for several decades because determining the optimal conditions for conventional synthesis is often time-consuming. The synthesis of poly- and oligopeptides comprising various amino acids longer than a dipeptide continues to pose a challenge owing to the lack of knowledge about enzymatic mechanisms and owing to difficulty in optimizing the pH, temperature, and other reaction conditions. These drawbacks limit the applications of the chemoenzymatic approach. Recently, a variety of enzymes and substrates produced using recombinant techniques, substrate mimetics, and optimal reaction conditions (e.g., frozen aqueous media and ionic liquids) have broadened the scope of chemoenzymatic peptide syntheses. In this review, we highlight the recent advances in the chemoenzymatic syntheses of various peptides and their use in developing new materials and biomedical applications. PMID:25191871

Yazawa, Kenjiro; Numata, Keiji

2014-01-01

360

Recent Advances in Chemoenzymatic Peptide Syntheses  

Directory of Open Access Journals (Sweden)

Full Text Available Chemoenzymatic peptide synthesis is the hydrolase-catalyzed stereoselective formation of peptide bonds. It is a clean and mild procedure, unlike conventional chemical synthesis, which involves complicated and laborious protection-deprotection procedures and harsh reaction conditions. The chemoenzymatic approach has been utilized for several decades because determining the optimal conditions for conventional synthesis is often time-consuming. The synthesis of poly- and oligopeptides comprising various amino acids longer than a dipeptide continues to pose a challenge owing to the lack of knowledge about enzymatic mechanisms and owing to difficulty in optimizing the pH, temperature, and other reaction conditions. These drawbacks limit the applications of the chemoenzymatic approach. Recently, a variety of enzymes and substrates produced using recombinant techniques, substrate mimetics, and optimal reaction conditions (e.g., frozen aqueous media and ionic liquids have broadened the scope of chemoenzymatic peptide syntheses. In this review, we highlight the recent advances in the chemoenzymatic syntheses of various peptides and their use in developing new materials and biomedical applications.

Kenjiro Yazawa

2014-09-01

 
 
 
 
361

Effects of age, sex and arm on the accuracy of arm position sense – Left-arm superiority in healthy right-handers  

Directory of Open Access Journals (Sweden)

Full Text Available Position sense is an important proprioceptive ability. Disorders of arm position sense (APS often occur after unilateral stroke, and are associated with a negative functional outcome. In the present study we assessed horizontal APS by measuring angular deviations from a visually defined target separately for each arm in a large group of healthy subjects. We analyzed the accuracy and instability of horizontal APS as a function of age, sex and arm. Subjects were required to specify verbally the position of their unseen arm on a 0-90° circuit by comparing the current position with the target position indicated by a LED lamp, while the arm was passively moved by the examiner. Eighty-seven healthy subjects participated in the study, ranging from 20 to 77 years, subdivided into three age groups. The results revealed that APS was not a function of age or sex, but was significantly better in the non-dominant (left arm in absolute but not in constant errors across all age groups of right-handed healthy subjects. This indicates a right-hemisphere superiority for left arm position sense in right-handers and neatly fits to the more frequent and more severe left-sided body-related deficits in patients with unilateral stroke (i.e. impaired arm position sense in left spatial neglect, somatoparaphrenia or in individuals with abnormalities of the right cerebral hemisphere. These clinical issues will be discussed.

LenaSchmidt

2013-12-01

362

Limitation and reduction of conventional arms  

International Nuclear Information System (INIS)

We are living at a time when war between East and West---not only nuclear but also conventional war--- is totally senseless. It cannot solve any problem---political, economic, or other. From the military point of view, war between East and West is madness. Calculations show that after 20 days of conventional warfare Europe could become another Hiroshima. Therefore we must work out forms of long-term cooperation. Before it is too late, we must radically reduce our military potentials and rethink our military doctrines. The reduction by 500,000 men is for the USSR no simple solution. But that step may become a model for further actions by East and West. The West's proposal that armed forces should be reduced to the level of 95 percent of NATO's armed forces is not a solution. Both sides---the Warsaw Treaty Organization and NATO---must be deprived of the capacity to launch a sudden attack; they must be deprived of their attack potential. The USSR initiative shows the true way toward that goal. What is happening in connection with our decision is not always correctly interpreted in the West, and so I should like to draw attention to some distinctive features of the Soviet armed forces reductions and, first of all, their scale (equivalent to the Bundeswehr of the Federal Republic of Germany). With respect to Europe, Soviet troops are to be reduced in the German Democratic Republic, Czechoslovakia, Hungary, Poland, and the European part of the Soviet Union---a total of 240,000 men, 10,000 tanks, 9,500 artillery systems, and 800 combat aircraft

363

Teeth clenching reduces arm abduction force.  

Science.gov (United States)

It has been reported that the 90° arm abduction force counteracting external adduction loads appeared to be smaller under teeth clenching condition than under non-clenching condition. To elucidate the physiological mechanism underlying the possible inhibitory effect of teeth clenching on the arm abduction, we have attempted to quantify the difference in the force induced against the fast and slow ramp load between the arm abductions under teeth non-clenching and clenching conditions. When the load of adduction moment was linearly increased, the abductor force increased to a maximal isometric contraction force (MICF) and further increased to a maximal eccentric contraction force (MECF) with forced adduction. The MICF measured under teeth clenching was significantly lower than that under non-clenching, despite no significant difference in the MECF between the two conditions. The reduction in MICF caused by teeth clenching was enhanced by increasing the velocity of the load. These results suggest that clenching inhibits abduction force only during isometric contraction phase. The invariability of MECF would indicate the lack of involvement of fatigue in such inhibitory effects of clenching. To discover the source of the inhibition, we have examined the effects of teeth clenching on the stretch reflex in the deltoid muscle. The stretch reflex of deltoid muscles was inhibited during clenching, contrary to what was expected from the Jendrassik maneuver. Taken together, our results suggest that the teeth clenching reduced the MICF by depressing the recruitment of deltoid motoneurones presumably via the presynaptic inhibition of spindle afferent inputs onto those motoneurones. PMID:24687460

Sato, Hajime; Kawano, Tsutomu; Saito, Mitsuru; Toyoda, Hiroki; Maeda, Yoshinobu; Türker, Kemal Sitki; Kang, Youngnam

2014-07-01

364

The globalization of the arms industry: The next proliferation challenge  

Energy Technology Data Exchange (ETDEWEB)

The globalization of the arms industry entails a significant shift away from traditional, single-country patterns of weapons production toward internationalization of the development, production, and marketing of arms. While wholly indigenous armaments production may be on the decline, multinational arms production - through collaboration on individual weapon systems and increasingly via interfirm linkages across the international arms industry - appears actually to be expanding. In several instances, in fact, multinational armaments production is increasingly supplementing or even supplanting indigenous or autonomous weapons production or arms imports. The emergence of an increasingly transnational defense technology and industrial base is fundamentally affecting the shape and content of much of the global arms trade. This changing defense market, in turn, will have a profound impact on a number of national security issues concerning the Western industrialized nations. 3 figs., 2 tabs.

Bitzinger, R.A.

1994-12-31

365

Defense, Armed Forces and Spanish Public Opinión  

Directory of Open Access Journals (Sweden)

Full Text Available Despite all the efforts made for adapting and modernizing our Armed Forces and thenew kind of missions they face, the Spaniards do not show much interest neither inquestions related to security and defense nor in supporting an increase in the defensebudget. This paper examines the reasons for the reported low level of culture of defenseexisting among the Spanish citizenry and the possibilities to act on this sort of causes inorder to offset its effects. Likewise, this report analyzes the measures adopted by theSpanish authorities in order to promote the culture of defense and highlights which aretheir main deficiencies and weaknesses

Inmaculada C. Marrero Rocha

2009-01-01

366

Nurse education in the British armed forces.  

Science.gov (United States)

Defence nurses form the largest registered specialty in the UK defence medical services. Once qualified, defence nurses maintain and develop their nursing and clinical skills in appropriate healthcare settings, and can be deployed in operational environments such as Afghanistan. Workforce planning and staffing establishment levels are defined to meet the needs of British armed forces, allies and, potentially, local populations. Since the workforce is geographically dispersed, deployed or undertaking non-clinical duties, there are constraints on nurses' attempts to maintain basic skills and access continuing professional development. This article explores the concept and the developing role of defence nurse lecturers in improving educational support for defence nurses. PMID:25315568

Carter, Chris; Finnegan, Alan P

2014-10-15

367

Interstellar extinction in the Perseus arm  

International Nuclear Information System (INIS)

Individual UV extinction curves for nine stars located in the direction of h and chi Persei in the distance range 0.6 to 4.4 kpc are presented. The observations were made with the International Ultraviolet Explorer (IUE) in the low dispersion mode with large aperture. The sample has been enlarged by the use of available UV and visible data for 32 reddened stars with distances r >= 2 kpc located in the same direction. It is found that the mean interstellar extinction curve for the stars located in the Perseus arm shows significantly higher extinction shortward of 2000 A than the galactic mean. (author)

368

Critical configurations of planar robot arms  

CERN Document Server

It is known that a closed polygon P is a critical point of the oriented area function if and only if P is a cyclic polygon, that is, $P$ can be inscribed in a circle. Moreover, there is a short formula for the Morse index. Going further in this direction, we extend these results to the case of open polygonal chains, or robot arms. We introduce the notion of the oriented area for an open polygonal chain, prove that critical points are exactly the cyclic configurations with antipodal endpoints and derive a formula for the Morse index of a critical configuration.

Khimshiashvili, G; Siersma, D; Zhukova, A

2012-01-01

369

The Multi-Armed Bandit, with Constraints  

CERN Document Server

The early sections of this paper present an analysis of a Markov decision model that is known as the multi-armed bandit under the assumption that the utility function of the decision maker is either linear or exponential. The analysis includes efficient procedures for computing the expected utility associated with the use of a priority policy and for identifying a priority policy that is optimal. The methodology in these sections is novel, building on the use of elementary row operations. In the later sections of this paper, the analysis is adapted to accommodate constraints that link the bandits.

Denardo, Eric V; Rothblum, Uriel G

2012-01-01

370

TRIGGERED STAR FORMATION IN SPIRAL ARMS  

Directory of Open Access Journals (Sweden)

Full Text Available We present the status of our research, relative to the triggering of star formation by large-scale galactic shocks associated with spiral density waves. Around a third of the galaxies in our sample do not seem suitable for this kind of study, because they present an e ect, probably due to opacity, that is not well understood. The remaining objects seem to favor the idea of density wave triggering of star formation in the arms. The comparison with stellar population synthesis models, and the orbital resonance positions for these galaxies (derived by means of spiral pattern angular speeds corroborate this hypothesis.

E. E. Mart\\u00EDnez-Garc\\u00EDa

2009-01-01

371

HS06 Benchmark for an ARM Server  

Science.gov (United States)

We benchmarked an ARM cortex-A9 based server system with a four-core CPU running at 1.1 GHz. The system used Ubuntu 12.04 as operating system and the HEPSPEC 2006 (HS06) benchmarking suite was compiled natively with gcc-4.4 on the system. The benchmark was run for various settings of the relevant gcc compiler options. We did not find significant influence from the compiler options on the benchmark result. The final HS06 benchmark result is 10.4.

Kluth, Stefan

2014-06-01

372

Algorithm That Synthesizes Other Algorithms for Hashing  

Science.gov (United States)

An algorithm that includes a collection of several subalgorithms has been devised as a means of synthesizing still other algorithms (which could include computer code) that utilize hashing to determine whether an element (typically, a number or other datum) is a member of a set (typically, a list of numbers). Each subalgorithm synthesizes an algorithm (e.g., a block of code) that maps a static set of key hashes to a somewhat linear monotonically increasing sequence of integers. The goal in formulating this mapping is to cause the length of the sequence thus generated to be as close as practicable to the original length of the set and thus to minimize gaps between the elements. The advantage of the approach embodied in this algorithm is that it completely avoids the traditional approach of hash-key look-ups that involve either secondary hash generation and look-up or further searching of a hash table for a desired key in the event of collisions. This algorithm guarantees that it will never be necessary to perform a search or to generate a secondary key in order to determine whether an element is a member of a set. This algorithm further guarantees that any algorithm that it synthesizes can be executed in constant time. To enforce these guarantees, the subalgorithms are formulated to employ a set of techniques, each of which works very effectively covering a certain class of hash-key values. These subalgorithms are of two types, summarized as follows: Given a list of numbers, try to find one or more solutions in which, if each number is shifted to the right by a constant number of bits and then masked with a rotating mask that isolates a set of bits, a unique number is thereby generated. In a variant of the foregoing procedure, omit the masking. Try various combinations of shifting, masking, and/or offsets until the solutions are found. From the set of solutions, select the one that provides the greatest compression for the representation and is executable in the minimum amount of time. Given a list of numbers, try to find one or more solutions in which, if each number is compressed by use of the modulo function by some value, then a unique value is generated.

James, Mark

2010-01-01

373

Improvements to GOES Twilight Cloud Detection over the ARM SGP  

Science.gov (United States)

The current ARM satellite cloud products derived from Geostationary Operational Environmental Satellite (GOES) data provide continuous coverage of many cloud properties over the ARM Southern Great Plains domain. However, discontinuities occur during daylight near the terminator, a time period referred to here as twilight. This poster presentation will demonstrate the improvements in cloud detection provided by the improved cloud mask algorithm as well as validation of retrieved cloud properties using surface observations from the Atmospheric Radiation Measurement Southern Great Plains (ARM SGP) site.

Yost, c. R.; Trepte, Q.; Khaiyer, M. M.; Palikonda, R.; Nguyen, L.

2007-01-01

374

“ONE-POT” SYNTHESES OF MALONDIALDEHYDE ADDUCTS OF NUCLEOSIDES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Short, “one-pot” syntheses of malondialdehyde adducts of deoxyguanosine, deoxyadenosine, and deoxycytidine are described. These syntheses proceed in improved yield and easier purification than previous syntheses and are well suited for the preparation of isotopically labeled nucleoside adducts for biomarker and metabolic studies.

Szekely, Jozsef; Wang, Hao; Peplowski, Katherine M.; Knutson, Charles G.; Marnett, Lawrence J.; Rizzo, Carmelo J.

2008-01-01

375

Computer code ARM1 for solving the inverse kinematics of a six-link manipulator arm  

International Nuclear Information System (INIS)

ARM1 is a FORTRAN 77 program for the numerical solutions of the inverse kinematics problems. This paper is a detailed description of the current program (version 1). The code is simple enough for practical use and besides has no particular restrictions except for the specification of memory size. Incorporated checking statements or routine are useful in identifying the accuracies of solutions obtained. (author)

376

Structure of the enzymatically synthesized fructan inulin  

Energy Technology Data Exchange (ETDEWEB)

Construction, purification and characterization of a fusion protein of maltose-binding protein of Escherichia coli and the fructosyltransferase of Streptococcus mutans is described. With the purified protein, in vitro synthesis of inulin was performed. The obtained polysaccharide was characterized by high-performance size-exclusion chromatography (HPSEC) and static light scattering (SLS) in dilute aqueous and dimethyl sulfoxide solution. For all samples very high molecular weights between 60x10{sup 6} and 90x10{sup 6} g/mol and a remarkable small polydispersity index of 1.1 have been determined. Small root-mean-square radii of gyration point to a compact conformation in dilute solution. No difference between native and enzymatically synthesized inulin was observed by X-ray powder diffraction and thermoanalysis of solid samples. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Heyer, A.G.; Schroeer, B. [Max-Planck-Institut fuer Molekulare Pflanzenphysiologie, Karl-Liebknecht-Str. 25, 14476 Golm (Germany); Radosta, S. [Fraunhofer-Institut fuer Angewandte Polymerforschung, Postfach 126, 14504 Teltow (Germany); Wolff, D.; Czapla, S.; Springer, J. [Technische Universitaet Berlin, FG Makromolekulare Chemie, Str. des 17. Juni 135, 10623 Berlin (Germany)

1998-12-15

377

PZT Powders Synthesized by Hydrothermal Method  

Directory of Open Access Journals (Sweden)

Full Text Available Lead zirconate titanate (PZT) powders with single―phase, cubic morphology and average size of 1 ?m were synthesized using hydrothermal methods. Effects of KOH concentration, hydrothermal treatment time and Pb excess were investigated. The results show that KOH concentration has an important influence on the solid solubility of Pb ion in A―site of PZT perovskite structure. The concentration of Pb2+ vacancies increased with the increase of OH― concentration. However, this kind of deficiency could be compensated by adding more Pb ions in the raw materials, and more Pb ions were needed to add with higher alkaline concentration in the starting solution. But excessive compensation of Pb ions would result in the appearance of the second phase.

ZHU Kong-Jun, ZHU Ren-Qiang, DONG Na-Na, GU Hong-Hui, QIU Jin-Hao, JI Hong-Li

2012-05-01

378

Syntheses and structures of terminal arylalumylene complexes.  

Science.gov (United States)

Terminal arylalumylene complexes of platinum [Ar-Al-Pt(PCy3 )2 ] (Ar=2,6-[CH(SiMe3 )2 ]2 C6 H3 (Bbp) or 2,6-[CH(SiMe3 )2 ]2 -4-(tBu)C6 H2 (Tbb)) have been synthesized either by the reaction of a dialumene-benzene adduct with [Pt(PCy3 )2 ], or by the reduction of 1,2-dibromodialumanes Ar(Br)Al-Al(Br)Ar in the presence of [Pt(PCy3 )2 ]. X-Ray crystallographic analysis reveals that the Al?Pt bond lengths of these arylalumylene complexes are shorter than the previously reported shortest Al?Pt distance. DFT calculations suggest that the Al?Pt bonds in the arylalumylene complexes have a significantly high electrostatic character. PMID:24616148

Nagata, Koichi; Agou, Tomohiro; Tokitoh, Norihiro

2014-04-01

379

[Facultative and obligate aerobic methylobacteria synthesize cytokinins].  

Science.gov (United States)

The presence and expression of genes controlling the synthesis and secretion of cytokinins by the pink-pigmented facultative methylotroph Methylobacterium mesophilicum VKM B-2143 with the serine pathway and nonpigmented obligate methylotroph Methylovorus mays VKM B-2221 with the ribulose monophosphate pathway of C1 metabolism were shown using the polymerase chain reaction (PCR) and reverse transcription-PCR methods. The presence of the corresponding mRNA in M. mesophilicum cells grown on methanol or succinate suggests that the expression of these genes is constitutive. The cytokinin activity of culture liquid and its fractions was determined by a biotest with Amarantus caudatus L. seedlings. Using enzyme-linked immunosorbent analysis, we detected zeatin (riboside) in the culture liquid of both bacteria studied. The data obtained show that the aerobic methylobacteria are phytosymbionts that are able to utilize the single- and polycarbon compounds secreted by symbiotic plants and to synthesize cytokinins. PMID:11195573

Ivanova, E G; Doronina, N V; Shepeliakovskaia, A O; Laman, A G; Brovko, F A; Trotsenko, Iu A

2000-01-01

380

Synthesizing Fault Tolerant Safety Critical Systems  

Directory of Open Access Journals (Sweden)

Full Text Available To keep pace with today’s nanotechnology, safety critical embedded systems are becoming less tolerant to errors. Research into techniques to cope with errors in these systems has mostly focused on transformational approach, replication of hardware devices, parallel program design, component based design and/or information redundancy. It would be better to tackle the issue early in the design process that a safety critical system never fails to satisfy its strict dependability requirements. A novel method is outlined in this paper that proposes an efficient approach to synthesize safety critical systems. The proposed method outperforms dominant existing work by introducing the technique of run time detection and completion of proper execution of the system in the presence of faults.

Seemanta Saha

2014-08-01

 
 
 
 
381

Structure of the enzymatically synthesized fructan inulin  

International Nuclear Information System (INIS)

Construction, purification and characterization of a fusion protein of maltose-binding protein of Escherichia coli and the fructosyltransferase of Streptococcus mutans is described. With the purified protein, in vitro synthesis of inulin was performed. The obtained polysaccharide was characterized by high-performance size-exclusion chromatography (HPSEC) and static light scattering (SLS) in dilute aqueous and dimethyl sulfoxide solution. For all samples very high molecular weights between 60x106 and 90x106 g/mol and a remarkable small polydispersity index of 1.1 have been determined. Small root-mean-square radii of gyration point to a compact conformation in dilute solution. No difference between native and enzymatically synthesized inulin was observed by X-ray powder diffraction and thermoanalysis of solid samples. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

382

Synthesizing plant phenological indicators from multispecies datasets  

Science.gov (United States)

Changes in the seasonality of life cycles of plants from phenological observations are traditionally analysed at the species level. Trends and correlations with main environmental driving variables show a coherent picture across the globe. The question arises whether there is an integrated phenological signal across species that describes common interannual variability. Is there a way to express synthetic phenological indicators from multispecies datasets that serve decision makers as usefull tools? Can these indicators be derived in such a robust way that systematic updates yield necessary information for adaptation measures? We address these questions by analysing multi-species phenological data sets with leaf-unfolding and flowering observations from 30 sites across Europe between 40° and 63°N including data from PEP725, the Swiss Plant Phenological Observation Network and one legacy data set. Starting in 1951 the data sets were synthesized by multivariate analysis (Principal Component Analysis). The representativeness of the site specific indicator was tested against subsets including only leaf-unfolding or flowering phases, and by a comparison with a 50% random sample of the available phenophases for 500 time steps. Results show that a synthetic indicators explains up to 79% of the variance at each site - usually 40-50% or more. Robust linear trends over the common period 1971-2000 indicate an overall change of the indicator of -0.32 days/year with lower uncertainty than previous studies. Advances were more pronounced in southern and northern Europe. The indicator-based analysis provides a promising tool for synthesizing site-based plant phenological records and is a companion to, and validating data for, an increasing number of phenological measurements derived from phenological models and satellite sensors.

Rutishauser, This; Peñuelas, Josep; Filella, Iolanda; Gehrig, Regula; Scherrer, Simon C.; Röthlisberger, Christian

2014-05-01

383

National Gas Survey. Synthesized gaseous hydrocarbon fuels  

Energy Technology Data Exchange (ETDEWEB)

The supply-Technical Advisory Task Force-Synthesized Gaseous Hydrocarbon Fuels considered coal, hydrocarbon liquids, oil shales, tar sands, and bioconvertible materials as potential feedstocks for gaseous fuels. Current status of process technology for each feedstock was reviewed, economic evaluations including sensitivity analysis were made, and constraints for establishment of a synthesized gaseous hydrocarbon fuels industry considered. Process technology is presently available to manufacture gaseous hydrocarbon fuels from each of the feedstocks. In 1975 there were eleven liquid feedstock SNG plants in the United States having a capacity of 1.1 billion SCFD. There can be no contribution of SNG before 1982 from plants using feedstocks other than liquids because there are no plants in operation or under construction as of 1977. Costs for SNG are higher than current regulated prices for U.S. natural gas. Because of large reserves, coal is a prime feedstock candidate although there are major constraints in the area of coal leases, mining and water permits, and others. Commercial technology is available and several new gasification processes are under development. Oil shale is also a feedstock in large supply and commercial process technology is available. There are siting and permit constraints, and water availability may limit the ultimate size of an oil shale processing industry. Under projected conditions, bioconvertible materials are not expected to support the production of large quantities of pipeline quality gas during the next decade. Production of low or medium Btu gas from municipal solid wastes can be expected to be developed in urban areas in conjunction with savings in disposal costs. In the economic evaluations presented, the most significant factor for liquid feedstock plants is the anticipated cost of feedstock and fuel. The economic viability of plants using other feedstocks is primarily dependent upon capital requirements.

None

1978-06-01

384

Impedance control of a dual-arm robot  

Science.gov (United States)

Intensive research efforts are currently directed toward special robotic applications. One of the largest international projects with a focus on this research is the Space Station Freedom. Canada's contribution to this project is a Mobile Servicing System (MSS). This system will be used for assembly and maintenance of the space station. The MSS will consist of a long single arm with a dual-arm robot attached to its end. They require a hierarchical controller to coordinate the arms while executing such tasks as trajectory generation, arm-arm collision avoidance, arm-obstacle collision avoidance, and the manipulation of solid and flexible body payloads. This thesis presents the research work for building a functional hardware and software model of a test-bed dual-arm robot with flexible object handling capabilities using impedance control. It addresses issues such as input-output linearization, perturbation observer, sensor fusion, and provides the experimental results of a dual-arm manipulator using the proposed techniques. To date, no work exists which shows that the application of a dual-arm robot handling flexible payloads in space applications is possible.

Jassemi-Zargani, Rahim

1998-12-01

385

Homework On The Moment Of Inertia Of A Human Arm  

Science.gov (United States)

Homework on the moment of inertia of a human arm was set to the first-year students in a dynamics class in a university. In this homework students must measure the sizes of several parts of their arm and calculate the moment of inertia of the arm and so on. They are requested to measure the period of swinging arm motion and compare it with that of calculated value in the case that it is assumed as a rigid body pendulum. The impressions of the students to the homework and the effects of the homework to the students were also examined.

Hirayama, Osamu

2010-07-01

386

SIPRI's new conceptual approach to arms control and disarmament  

International Nuclear Information System (INIS)

The end of the cold war deprioritized arms control and disarmament, and progress in the field was no longer a measure of relations among the major powers. In that context, the future of arms control and disarmament was discussed at the Nobel Symposium in October 1999. Stockholm International Peace Research Institute (SIPRI) views arms control as an instrument for shaping a new inclusive and cooperative security order. The author questions whether arms control challenges today can and should be resolved in the institutions established and the procedures elaborated in the bipolar framework. (author)

387

Poly(glycolide multi-arm star polymers: Improved solubility via limited arm length  

Directory of Open Access Journals (Sweden)

Full Text Available Due to the low solubility of poly(glycolic acid (PGA, its use is generally limited to the synthesis of random copolyesters with other hydroxy acids, such as lactic acid, or to applications that permit direct processing from the polymer melt. Insolubility is generally observed for PGA when the degree of polymerization exceeds 20. Here we present a strategy that allows the preparation of PGA-based multi-arm structures which significantly exceed the molecular weight of processable oligomeric linear PGA (<1000 g/mol. This was achieved by the use of a multifunctional hyperbranched polyglycerol (PG macroinitiator and the tin(II-2-ethylhexanoate catalyzed ring-opening polymerization of glycolide in the melt. With this strategy it is possible to combine high molecular weight with good molecular weight control (up to 16,000 g/mol, PDI = 1.4–1.7, resulting in PGA multi-arm star block copolymers containing more than 90 wt % GA. The successful linkage of PGA arms and PG core via this core first/grafting from strategy was confirmed by detailed NMR and SEC characterization. Various PG/glycolide ratios were employed to vary the length of the PGA arms. Besides fluorinated solvents, the materials were soluble in DMF and DMSO up to an average arm length of 12 glycolic acid units. Reduction in the Tg and the melting temperature compared to the homopolymer PGA should lead to simplified processing conditions. The findings contribute to broadening the range of biomedical applications of PGA.

Florian K. Wolf

2010-06-01

388

Structured Molecular Gas Reveals Galactic Spiral Arms  

CERN Document Server

We explore the development of structures in molecular gas in the Milky Way by applying the analysis of the brightness distribution function (BDF) and the brightness distribution index (BDI) in the archival data from the Boston University-Five College Radio Astronomy Observatory 13CO J=1-0 Galactic Ring Survey. The BDI measures the fractional contribution of spatially confined bright molecular emission over faint emission extended over large areas. This relative quantity is largely independent of the amount of molecular gas and of any conventional, pre-conceived structures, such as cores, clumps, or giant molecular clouds. The structured molecular gas traced by higher BDI is located continuously along the spiral arms in the Milky Way in the longitude-velocity diagram. This clearly indicates that molecular gas changes its structure as it flows through the spiral arms. Although the high-BDI gas generally coincides with H II regions, there is also some high-BDI gas with no/little signature of ongoing star formati...

Sawada, Tsuyoshi; Koda, Jin

2012-01-01

389

Characterizing Truthful Multi-Armed Bandit Mechanisms  

CERN Document Server

We consider a multi-round auction setting motivated by pay-per-click auctions for Internet advertising. In each round the auctioneer selects an advertiser and shows her ad, which is then either clicked or not. An advertiser derives value from clicks; the value of a click is her private information. Initially, neither the auctioneer nor the advertisers have any information about the likelihood of clicks on the advertisements. The auctioneer's goal is to design a (dominant strategies) truthful mechanism that (approximately) maximizes the social welfare. If the advertisers bid their true private values, our problem is equivalent to the "multi-armed bandit problem", and thus can be viewed as a strategic version of the latter. In particular, for both problems the quality of an algorithm can be characterized by "regret", the difference in social welfare between the algorithm and the benchmark which always selects the same "best" advertisement. We investigate how the design of multi-armed bandit algorithms is affect...

Babaioff, Moshe; Slivkins, Aleksandrs

2008-01-01

390

Boundary Layer Cloudiness Parameterizations Using ARM Observations  

Energy Technology Data Exchange (ETDEWEB)

This study used DOE ARM data and facilities to: (1) study macroscopic properties of continental stratus clouds at SGP and the factors controlling these properties, (2) develop a scientific basis for understanding the processes responsible for the formation of boundary layer clouds using ARM observations in conjunction with simple parametric models and LES, and (3) evaluate cumulus cloud characteristics retrieved from the MMCR operating at TWP-Nauru. In addition we have used high resolution 94 GHz observations of boundary layer clouds and precipitation to: (1) develop techniques for using high temporal resolution Doppler velocities to study large-eddy circulations and turbulence in boundary layer clouds and estimate the limitations of using current and past MMCR data for boundary layer cloud studies, (2) evaluate the capability and limitations of the current MMCR data for estimating reflectivity, vertical velocities, and spectral under low- signal-to-noise conditions associated with weak no n-precipitating clouds, (3) develop possible sampling modes for the new MMCR processors to allow for adequate sampling of boundary layer clouds, and (4) retrieve updraft and downdraft structures under precipitating conditions.

Bruce Albrecht

2004-09-15

391

ARM 7 BASED MP3 PLAYER  

Directory of Open Access Journals (Sweden)

Full Text Available MP3 is a patented encoding format for digital audio which uses a form of lossy data compression. It is a common audio format for consumer audio streaming or storage, as well as a de facto standard of digital audio compression for the transfer and playback of music on most digital audio players. Since the MPEG-1 Layer III encoding technology is nowadays widely used it might be interesting to gain knowledge of how this powerful compression/decompression scheme actually functions. The MPEG-1 Layer III is capable of reducing the bit rate with a factor of 12 without almost any audible degradation. Arm7 lpc2148 is arm7tdmi-s core board microcontroller that uses 16/32-bit 64 pin (lqfp microcontroller no.lpc2148 from Philips (nxp.The hardware system of lpc2148 includes the necessary devices within only one mcu has such as usb, adc, dac, timer/counter, pwm, capture, i2c, spi, uart, and etc.

Ashiq V Mehta

2014-02-01

392

Double arm handling device for nuclear reactor  

International Nuclear Information System (INIS)

The invention concerns a machine which, inside a liquid sodium cooled reactor, makes it possible to transfer fuel assemblies forming the core, between the positions that these assemblies fill inside the core to a storage position for these fuel assemblies inside the vessel. These operations are carried out when the reactor plug is in position and when the vessel is filled with liquid sodium, hence they are carried out without being seen. The improved charging system enables the handling time to be cut to a minimum and to diminish the number of positioning operations of the handling system inside the reactor vessel to effect the various charging and discharging operations. It includes a vertically positioned drum of which the top end crosses the plug; a first truck guided in vertical translation by guiding facilities integral with the drum and a second truck guided in vertical translation by other guiding facilities also integral with the drum, each truck being fitted with a horizontal arm at the free end of which is placed a grab hook for holding the fuel assemblies, the guiding facilities being such that the arms remain parallel to each other; gear for moving the trucks vertically and separately; facilities for controlling the opening and closing of the grabs and gear for turning the drum vertically about its centre line

393

On ergodic two-armed bandits  

CERN Document Server

A device has two arms with unknown deterministic payoffs, and the aim is to asymptotically identify the best one without spending too much time on the other. The Narendra algorithm offers a stochastic procedure to this end. We show under weak ergodic assumptions on these deterministic payoffs that the procedure eventually chooses the best arm (i.e. with greatest Cesaro limit) with probability one, for appropriate step sequences of the algorithm. In the case of i.i.d. payoffs, this implies a "quenched" version of the "annealed" result of Lamberton, Pages and Tarres in 2004 by the law of iterated logarithm, thus generalizing it. More precisely, if $(\\eta_{l,i})_{i\\in\\N}\\in\\{0,1\\}^\\N$, $l\\in\\{A,B\\}$, are the deterministic reward sequences we would get if we played at time $i$, we obtain infallibility with the same assumption on nonincreasing step sequences on the payoffs as in the result mentioned above, replacing the i.i.d. assumption by the hypothesis that the empirical averages $\\sum_{i=1}^n\\eta_{A,i}/n$ and$...

Tarrès, Pierre

2009-01-01

394

ARM Climate Research Facility Annual Report 2004  

Energy Technology Data Exchange (ETDEWEB)

Like a rock that slowly wears away beneath the pressure of a waterfall, planet earth?s climate is almost imperceptibly changing. Glaciers are getting smaller, droughts are lasting longer, and extreme weather events like fires, floods, and tornadoes are occurring with greater frequency. Why? Part of the answer is clouds and the amount of solar radiation they reflect or absorb. These two factors clouds and radiative transfer represent the greatest source of error and uncertainty in the current generation of general circulation models used for climate research and simulation. The U.S. Global Change Research Act of 1990 established an interagency program within the Executive Office of the President to coordinate U.S. agency-sponsored scientific research designed to monitor, understand, and predict changes in the global environment. To address the need for new research on clouds and radiation, the U.S. Department of Energy (DOE) established the Atmospheric Radiation Measurement (ARM) Program. As part of the DOE?s overall Climate Change Science Program, a primary objective of the ARM Program is improved scientific understanding of the fundamental physics related to interactions between clouds and radiative feedback processes in the atmosphere.

Voyles, J.

2004-12-31

395

Europe, arms control and American security  

International Nuclear Information System (INIS)

What has come to be called the Revolution of 1989 has swept away longstanding political and economic arrangements in Eastern Europe. Perhaps more important, it has also called into question the fundamental underpinnings of European security created during the nonpeace that followed World War II. In June 1990, the Warsaw Treaty Organization abandoned the notion that NATO was the ideological enemy. At the same time, NATO ministers agreed at Tunberry, Scotland, to consider defining the Atlantic Alliance as more of a partner of the Soviet Union than as an enemy. The Washington summit of May 1990 between president Mikhail Gorbachev and president George Bush further highlighted the recent changes in the Soviet Union and its former satellites. Issues going to the heart of the viability of the Soviet Union and the communist system of political and economic organization competed with German reunification as central themes. Arms control issues, particularly as they pertain in European military stability, became contingent and dependent on the development of a broader political and economic framework for a new Europe. Whether this framework is viable remains an open question as Gorbachev's role is challenged more and more within the Soviet Union. This paper deals with European arms control issues from the point of view of the United States and its own security interests. The United States involved its security inextricably with that of Western Europe as a conscious decision in testern Europe as a conscious decision in the turmoil following World War II

396

Porting Android on Arm Based Platform  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract:Today Android operating system (OS is HOT in market for entertainment devices like mobile phones and tablet and TV and industry is exploring the ability of Android within other embedded platforms. Some industries replace with exiting operating system with Android because main reason is open source operating system (OS. Today industries select Android OS reason behind this big application market and easy to available to application development tools and also available many on-line group to resolve your issue. In this paper, we will explain the concept of porting android to any arm based devices. We will explain the basics of kernel, how to make android specific, how to compile kernel for ARM. In Android section, we will explain architecture of Android, how to compile android for specific board. For understanding, we will use Linux 2.6.32 kernel version and android 2.3.7 (Gingerbread. We will port android to d2plug board which is product of Marvell Semiconductor.

KALPIK M. PATEL, CHIRAG K. PATEL

2013-05-01

397

Two Pathways for Electrocatalytic Oxidation of Hydrogen by a Nickel Bis(diphosphine) Complex with Pendant Amines in the Second Coordination Sphere  

Energy Technology Data Exchange (ETDEWEB)

A nickel bis(diphosphine) complex containing pendant amines in the second coordination sphere, [Ni(PCy2Nt-Bu2)2](BF4)2 (PCy2Nt-Bu2 = 1,5-di(tert-butyl)-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane), is an electrocatalyst for hydrogen oxidation. Under 1.0 atm H2 using NEt3 as a base and with added water, a turnover frequency of 45 s-1 is observed at 23 °C; this is the fastest observed for a molecular catalyst. The addition of hydrogen to the NiII complex gives thee isomers of the doubly protonated Ni0 complex [Ni(PCy2HNt-Bu2)2](BF4)2; these complexes have been studied by 1H and 31P NMR spectroscopy, and for one isomer, an X-ray diffraction study. Using the pKa values and NiII/I and NiI/0 redox potentials in a thermochemical cycle, the free energy of hydrogen addition to [Ni(PCy2Nt-Bu2)2]2+ was determined to be -7.9 kcal mol-1. The catalytic rate observed in dry acetonitrile for the oxidation of H2 at the NiII/I couple depends on base size, with larger bases (NEt3, tert-BuNH2) resulting in slower catalysis than n-BuNH2. Addition of water accelerates the rate of catalysis, especially for the larger bases. The results of these studies provide important insights into the design of catalysts for hydrogen oxidation that facilitate proton movement and operate at moderate potentials. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Yang, Jenny Y.; Smith, Stuart E.; Liu, Tianbiao L.; Dougherty, William G.; Hoffert, Wesley A.; Kassel, W. S.; Rakowski DuBois, Mary; DuBois, Daniel L.; Bullock, R. Morris

2013-07-03

398

Measurement of the Surface Dilatational Viscosity of an Insoluble Surfactant Monolayer at the Air/Water Interface Using a Pendant Drop Apparatus  

Science.gov (United States)

When a fluid interface with surfactants is at rest, the interfacial stress is isotropic (as given by the equilibrium interfacial tension), and is described by the equation of state which relates the surface tension to the surfactant surface concentration. When surfactants are subjected to shear and dilatational flows, flow induced interaction of the surfactants; can create interfacial stresses apart from the equilibrium surface tension. The simplest relationship between surface strain rate and surface stress is the Boussinesq-Scriven constitutive equation completely characterized by three coefficients: equilibrium interfacial tension, surface shear viscosity, and surface dilatational viscosity Equilibrium interfacial tension and surface shear viscosity measurements are very well established. On the other hand, surface dilatational viscosity measurements are difficult because a flow which change the surface area also changes the surfactant surface concentration creating changes in the equilibrium interfacial tension that must be also taken into account. Surface dilatational viscosity measurements of existing techniques differ by five orders of magnitude and use spatially damped surface waves and rapidly expanding bubbles. In this presentation we introduce a new technique for measuring the surface dilatational viscosity by contracting an aqueous pendant drop attached to a needle tip and having and insoluble surfactant monolayer at the air-water interface. The isotropic total tension on the surface consists of the equilibrium surface tension and the tension due to the dilation. Compression rates are undertaken slow enough so that bulk hydrodynamic stresses are small compared to the surface tension force. Under these conditions we show that the total tension is uniform along the surface and that the Young-Laplace equation governs the drop shape with the equilibrium surface tension replaced by the constant surface isotropic stress. We illustrate this technique using DPPC as the insoluble surfacant monolayer and measured for it a surface dilatational viscosity in the LE phase that is 20 surface poise.

Lorenzo, Jose; Couzis, Alex; Maldarelli, Charles; Singh, Bhim S. (Technical Monitor)

2000-01-01

399

The potential of transferrin-pendant-type polyethyleneglycol liposomes encapsulating decahydrodecaborate-1B (GB-10) as 1B-carriers for boron neutron capture therapy  

International Nuclear Information System (INIS)

Purpose: To evaluate GB-10-encapsulating transferrin (TF)-pendant-type polyethyleneglycol (PEG) liposomes as tumor-targeting 1B-carriers for boron neutron capture therapy. Methods and Materials: A free mercaptoundecahydrododecaborate-1B (BSH) or decahydrodecaborate-1B (GB-10) solution, bare liposomes, PEG liposomes, or TF-PEG liposomes were injected into SCC VII tumor-bearing mice, and 1B concentrations in the tumors and normal tissues were measured by ?-ray spectrometry. Meanwhile, tumor-bearing mice were continuously given 5-bromo-2'-deoxyuridine (BrdU) to label all intratumor proliferating cells, then injected with these 1B-carriers containing BSH or GB-10 in the same manner. Right after thermal neutron irradiation, the response of quiescent (Q) cells was assessed in terms of the micronucleus frequency using immunofluorescence staining for BrdU. The frequency in the total tumor cells was determined from the BrdU nontreated tumors. Results: Transferrin-PEG liposomes showed a prolonged retention in blood circulation, low uptake by reticuloendothelial system, and the most enhanced accumulation of 1B in solid tumors. In general, the enhancing effects were significantly greater in total cells than Q cells. In both cells, the enhancing effects of GB-10-containing 1B-carriers were significantly greater than BSH-containing 1B-carriers, whether loaded in free solution or liposomes. In boaded in free solution or liposomes. In both cells, whether BSH or GB-10 was employed, the greatest enhancing effect was observed with TF-PEG liposomes followed in decreasing order by PEG liposomes, bare liposomes, and free BSH or GB-10 solution. In Q cells, the decrease was remarkable between PEG and bare liposomes. Conclusions: In terms of biodistribution characteristics and tumor cell-killing effect as a whole, including Q cells, GB-10 TF-PEG liposomes were regarded as promising 1B-carriers

400

Methyltriethoxysilane: New precursor for synthesizing silica aerogels  

International Nuclear Information System (INIS)

Traditionally, silica aerogels are synthesized using three silicon alkoxides, namely, tetraethoxysilane (TEOS), tetramethoxysilane (TMOS) and methyltrimethoxysilane (MTMS) for various applications in science as well as in technology. Among all these precursors, only MTMS-based silica aerogels are inherently superhydrophobic with so far reported, the highest contact angle of 173 deg. In the present paper, we reported a new precursor, namely, methyltriethoxysilane (MTES) for synthesizing the silica aerogels having the novel properties as that of MTMS-based aerogels. The aerogels have been prepared using the MTES by two-stage acid-base catalyzed sol-gel process followed by supercritical drying. The solvent and catalysts used for the synthesis were methanol (MeOH), oxalic acid (C2H2O4) and ammonium hydroxide (NH4OH), respectively. The aerogels of different densities were obtained by varying the molar ratio of MeOH/MTES (S) from 6.45 to 19.35. In order to get good quality aerogels in terms of low density, high contact angle and less volume shrinkage, the oxalic acid (A) and NH4OH (B) concentrations were varied from 0 to 1 and from 2 to 13.36 M, respectively. Monolithic aerogels have been obtained for the values of A = 0.01 M and B = 13.36 M. Simultaneously, the aerogels are superhydrophobic with contact angle as high as 163 deg. Furthermore, the effects of molar ratio of H2O/MTES (W1), i.e. acidic water and 2O/MTES (W1), i.e. acidic water and H2O/MTES (W2), i.e. basic water on the physical properties of the aerogels have also been studied. The molar ratio of MTES:MeOH:acidic water:basic water was optimized at 1:19.35:3.57:3.57, respectively. The aerogel thermal stability was studied by TGA-DTA while the hydrophobicity was quantified in terms of the contact angle measurements and FTIR studies. The as-prepared aerogels have been characterized by bulk density, porosity, volume shrinkage, thermal conductivity, contact angle measurements, transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The physical properties of the aerogels have been explained by taking into account of sol-gel reactions and the gel network formation

 
 
 
 
401

Efficacy of some synthesized thiazoles against dermatophytes.  

Science.gov (United States)

Twelve thiazoles and their fused derivatives were tested for their antimicrobial activity against Trichophyton rubrum, T. terrestre, Epidermophyton floccosum, and Microsporum gypseum. Most of the synthesized compounds were inhibitory to the tested fungi. The most effective compound was 5-(4-ethoxybenzylidene-4,5-dihydro-4-oxothiazol-2-yl)-N,3-diphenylbut-2-namide (3c) followed by 2-(4-oxo-4,5-dihydrothiazol-2-yl)-3-phenyl-but-2-enoic acid-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-amide (2b). These compounds were more efficacious than terbinafine, the reference drug. The tested compounds caused variable reduction in the activity of keratinase of the dermatophytes, depending on the azole derivative and the test fungus. Thiazole derivatives (2b) and (3c) exhibited the highest efficacy in decreasing ergosterol biosynthesis of the tested dermatophytes. The treatment of guinea pigs with compound (3c) induced complete curing in the case of all the test dermatophytes 30days post-treatment. The percent curing for compounds (3c) and (2b) was better than the reference drug. PMID:24129248

Ouf, S A; Taleb, A M Abu; Tharwat, N A; Geweely, N S

2013-12-01

402

Why can't vertebrates synthesize trehalose?  

Science.gov (United States)

The non-reducing disaccharide trehalose is a singular molecule, which has been strictly conserved throughout evolution in prokaryotes (bacteria and archaea), lower eukaryotes, plants, and invertebrates, but is absent in vertebrates and-more specifically-in mammals. There are notable differences regarding the pivotal roles played by trehalose among distantly related organisms as well as in the specific metabolic pathways of trehalose biosynthesis and/or hydrolysis, and the regulatory mechanisms that control trehalose expression genes and enzymatic activities. The success of trehalose compared with that of other structurally related molecules is attributed to its exclusive set of physical properties, which account for its physiological roles and have also promoted important biotechnological applications. However, an intriguing question still remains: why are vertebrates in general, and mammals in particular, unable (or have lost the capacity) to synthesize trehalose? The search for annotated genomes of vertebrates reveals the absence of any functional trehalose synthase gene. Indeed, this is also true for the human genome, which contains, however, two genes encoding for isoforms of the hydrolytic activity (trehalase). Although we still lack a convincing answer, this striking difference might reflect the divergent evolutionary lineages followed by invertebrates and vertebrates. Alternatively, some clinical data point to trehalose as a toxic molecule when stored inside the human body. PMID:25230776

Argüelles, Juan-Carlos

2014-10-01

403

Ethics and nuclear arms: European and American perspectives  

Energy Technology Data Exchange (ETDEWEB)

This book presents papers on the ethical and moral aspects of nuclear weapons. Topics considered include the development of a nuclear policy, war and peace in the nuclear age, the viewpoint of the German churches, the US Catholic bishops and nuclear arms, nuclear pacifism, NATO and ''first use,'' and Christian morality with regard to nuclear arms.

English, R.

1985-01-01

404

Stellar dynamics around transient co-rotating spiral arms  

Directory of Open Access Journals (Sweden)

Full Text Available Spiral density wave theory attempts to describe the spiral pattern in spiral galaxies in terms of a long-lived wave structure with a constant pattern speed in order to avoid the winding dilemma. The pattern is consequently a rigidly rotating, long-lived feature. We run an N-body/SPH simulation of a Milky Way-sized barred disk, and find that the spiral arms are transient features whose pattern speeds decrease with radius, in such a way that the pattern speed is almost equal to the rotation curve of the galaxy. We trace particle motion around the spiral arms. We show that particles from behind and in front of the spiral arm are drawn towards and join the arm. Particles move along the arm in the radial direction and we find a clear trend that they migrate toward the outer (inner radii on the trailing (leading side of the arm. Our simulations demonstrate that tat all radii where there is a co-rotating spiral arm the particles continue to be accelerated (decelerated by the spiral arm for long periods, which leads to strong migration.

Cropper M.

2012-02-01

405

Kinematic feedback control laws for generating natural arm movements.  

Science.gov (United States)

We propose a stochastic optimal feedback control law for generating natural robot arm motions. Our approach, inspired by the minimum variance principle of Harris and Wolpert (1998 Nature 394 780-4) and the optimal feedback control principles put forth by Todorov and Jordan (2002 Nature Neurosci. 5 1226-35) for explaining human movements, differs in two crucial respects: (i) the endpoint variance is minimized in joint space rather than Cartesian hand space, and (ii) we ignore the dynamics and instead consider only the second-order differential kinematics. The feedback control law generating the motions can be straightforwardly obtained by backward integration of a set of ordinary differential equations; these equations are obtained exactly, without any linear-quadratic approximations. The only parameters to be determined a priori are the variance scale factors, and for both the two-DOF planar arm and the seven-DOF spatial arm, a table of values is constructed based on the given initial and final arm configurations; these values are determined via an optimal fitting procedure, and consistent with existing findings about neuromuscular motor noise levels of human arm muscles. Experiments conducted with a two-link planar arm and a seven-DOF spatial arm verify that the trajectories generated by our feedback control law closely resemble human arm motions, in the sense of producing nearly straight-line hand trajectories, having bell-shaped velocity profiles, and satisfying Fitts Law. PMID:24343165

Kim, Donghyun; Jang, Cheongjae; Park, Frank C

2014-03-01

406

A Molecular Spiral Arm in the Far Outer Galaxy  

CERN Document Server

We have identified a spiral arm lying beyond the Outer Arm in the first Galactic quadrant ~15 kpc from the Galactic center. After tracing the arm in existing 21 cm surveys, we searched for molecular gas using the CfA 1.2 meter telescope and detected CO at 10 of 220 positions. The detections are distributed along the arm from l = 13 deg, v = -21 km/s to l = 55 deg, v = -84 km/s and coincide with most of the main H I concentrations. One of the detections was fully mapped to reveal a large molecular cloud with a radius of 47 pc and a molecular mass of ~50,000 Mo. At a mean distance of 21 kpc, the molecular gas in this arm is the most distant yet detected in the Milky Way. The new arm appears to be the continuation of the Scutum-Centaurus Arm in the outer Galaxy, as a symmetric counterpart of the nearby Perseus Arm.

Dame, T M

2011-01-01

407

Dynamic Coordination Of A Two-Arm Robotic Manipulator  

Science.gov (United States)

Report presents study of dynamical and kinematical considerations guiding selection of configuration of self-reconfigurable, two-arm robotic manipulator. Two multiple-link arms cooperate in manipulating single object, reconfiguring their mutual, cooperative structure according to changing task requirements.

Lee, Sukhan; Kim, Sungbok

1994-01-01

408

ARM tõestab, et ka analüütikud eksivad / Fredy-Edwin  

Index Scriptorium Estoniae

Apple'i iPadidele ja iPhone'idele kiipe tootva Suurbritannia firma ARM Holdings aktsia on kõige suurem tõusja Londoni FTSE 100 indeksi kuue kuu, 12 kuu, 18 kuu, kahe aasta ja kolme aasta lõikes, samas on analüütikud kõigist indeksi aktsiatest kõige negatiivsemalt meelestatud just ARM Holdingsi suhtes. Graafik

Esse, Fredy-Edwin

2011-01-01

409

Are the arms and legs in competition for cardiac output?  

Science.gov (United States)

Oxygen transport to working skeletal muscles is challenged during whole-body exercise. In general, arm-cranking exercise elicits a maximal oxygen uptake (VO2max) corresponding to approximately 70% of the value reached during leg exercise. However, in arm-trained subjects such as rowers, cross-country skiers, and swimmers, the arm VO2max approaches or surpasses the leg value. Despite this similarity between arm and leg VO2max, when arm exercise is added to leg exercise, VO2max is not markedly elevated, which suggests a central or cardiac limitation. In fact, when intense arm exercise is added to leg exercise, leg blood flow at a given work rate is approximately 10% less than during leg exercise alone. Similarly, when intense leg exercise is added to arm exercise, arm blood flow and muscle oxygenation are reduced by approximately 10%. Such reductions in regional blood flow are mainly attributed to peripheral vasoconstriction induced by the arterial baroreflex to support the prevailing blood pressure. This putative mechanism is also demonstrated when the ability to increase cardiac output is compromised; during exercise, the prevailing blood pressure is established primarily by an increase in cardiac output, but if the contribution of the cardiac output is not sufficient to maintain the preset blood pressure, the arterial baroreflex increases peripheral resistance by augmenting sympathetic activity and restricting blood flow to working skeletal muscles. PMID:17019302

Secher, Niels H; Volianitis, Stefanos

2006-10-01

410

AGRICULTURAL RUNOFF MANAGEMENT (ARM) MODEL VERSION II: REFINEMENT AND TESTING  

Science.gov (United States)

The Agricultural Runoff Management (ARM) Model has been refined and tested on small agricultural watersheds in Georgia and Michigan. The ARM Model simulates the hydrologic, sediment production, pesticide, and nutrient processes on the land surface and in the soil profile that det...

411

Risk factors of arm lymphedema in breast cancer patients  

DEFF Research Database (Denmark)

Chronic lymphedema is a life-long, potential complication of axillary treatment for breast cancer patients. In this article we focus on risk factors in the development of arm lymphedema and also discuss definition, type and stage, and incidence of arm edema.

Kocak, Z; Overgaard, J

2000-01-01

412

Extravehicular activity translation arm (EVATA) study  

Science.gov (United States)

The preliminary design of a deployable Extravehicular Activity Translation Arm (EVATA) assembly which will allow an EVA crewman to perform tasks in the vicinity of the External TNK (ET) umbilical doors and to inspect most of the underside of the shuttle spacecraft is reported. The concept chosen for the boom structure was the Astro Extendable Support Structure (ESS) which formed the main structure for the Synthetic Aperture Radar (SAR) Antenna System on the SEASAT A spacecraft. This structure is a deployable triangular truss. A comparison of the EVATA and the SEASAT A ESS is shown. The development of status of the ESS is shown. The satellite configuration, the stowed truss load path, and the envelope deployment sequence for the ESS are also shown.

Preiswerk, P. R.; Stammreich, J. R.

1978-01-01

413

Homeobox genes expressed during echinoderm arm regeneration.  

Science.gov (United States)

Regeneration in echinoderms has proved to be more amenable to study in the laboratory than the more classical vertebrate models, since the smaller genome size and the absence of multiple orthologs for different genes in echinoderms simplify the analysis of gene function during regeneration. In order to understand the role of homeobox-containing genes during arm regeneration in echinoderms, we isolated the complement of genes belonging to the Hox class that are expressed during this process in two major echinoderm groups: asteroids (Echinaster sepositus and Asterias rubens) and ophiuroids (Amphiura filiformis), both of which show an extraordinary capacity for regeneration. By exploiting the sequence conservation of the homeobox, putative orthologs of several Hox genes belonging to the anterior, medial, and posterior groups were isolated. We also report the isolation of a few Hox-like genes expressed in the same systems. PMID:24309817

Ben Khadra, Yousra; Said, Khaled; Thorndyke, Michael; Martinez, Pedro

2014-04-01

414

ARM Surface Meteorology Systems Instrument Handbook  

Energy Technology Data Exchange (ETDEWEB)

The ARM Surface Meteorology Systems consist mainly of conventional in situ sensors that obtain a defined “core” set of measurements. The core set of measurements is: Barometric Pressure (kPa), Temperature (°C), Relative Humidity (%), Arithmetic-Averaged Wind Speed (m/s), Vector-Averaged Wind Speed (m/s), and Vector-Averaged Wind Direction (deg). The sensors that collect the core variables are mounted at the standard heights defined for each variable: • Winds: 10 meters • Temperature and Relative Humidity: 2 meters • Barometric Pressure: 1 meter. Depending upon the geographical location, different models and types of sensors may be used to measure the core variables due to the conditions experienced at those locations. Most sites have additional sensors that measure other variables that are unique to that site or are well suited for the climate of the location but not at others.

Ritsche, MT

2011-03-08

415

Cloud and Star Formation in Spiral Arms  

CERN Document Server

We present the results from simulations of GMC formation in spiral galaxies. First we discuss cloud formation by cloud-cloud collisions, and gravitational instabilities, arguing that the former is prevalent at lower galactic surface densities and the latter at higher. Cloud masses are also limited by stellar feedback, which can be effective before clouds reach their maximum mass. We show other properties of clouds in simulations with different levels of feedback. With a moderate level of feedback, properties such as cloud rotations and virial parameters agree with observations. Without feedback, an unrealistic population of overly bound clouds develops. Spiral arms are not found to trigger star formation, they merely gather gas into more massive GMCs. We discuss in more detail interactions of clouds in the ISM, and argue that these are more complex than early ideas of cloud-cloud collisions. Finally we show ongoing work to determine whether the Milky Way is a flocculent or grand design spiral.

Dobbs, Clare

2014-01-01

416

'Great power' intervention in African armed conflicts  

DEFF Research Database (Denmark)

This paper asks why the United States (US), China and the European Union (EU) have intervened in a number of armed conflicts in Africa in the twenty-first century. Scrutiny and comparison of the motivations and interests of the three non-African actors in intervening in African crises are assumed to contribute to understanding the changing geopolitical environment and the current conditions for conflict management in Africa. The focus is not on trade and aid. The paper launches the hypothesis that the explanations why the US, China and the EU have intervened are basically identical. In spite of different evaluations of the specific crisis situations, the interventions have been about taking care of the ‘national interest’ of each of the three non-African actors. National interest is defined as either ‘hard core’ (security) or ‘core’ concerns (security and economic wealth).

Olsen, Gorm Rye

2014-01-01

417

ARMED FORCES AND INTERVENTION IN TROPICAL AFRICA  

Directory of Open Access Journals (Sweden)

Full Text Available "The Ghana Armed Forces, in co-operation with the police, have thought it necessary to take over the reins of power and to dismiss the former President, Kwame Nkrumah, the Presidential Commission and all Ministers, and to suspend the Constitution and to dissolve Parliament. This act has been necessitated by the political and economic situation in the country. The concentration of power in the hands of one man has led to the abuse of individual rights and liberty. Power has been exercised by the former President capriciously. The operation of the laws has been suspended to the advantage of his favourites and he has been running the country as his own personal property. "

L. Steyn

2012-02-01

418

Object Sorting System Using Robotic Arm  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents a smart approach for a real time inspection and selection of objects in continuous flow. Image processing in today’s world grabs massive attentions as it leads to possibilities of broaden application in many fields of high technology. The real challenge is how to improve existing sorting system in the modular processing system which consists of four integrated stations of identification, processing, selection and sorting with a new image processing feature. Existing sorting method uses a set of inductive, capacitive and optical sensors do differentiate object color. This paper presents a mechatronics color sorting system solution with the application of image processing. Image processing procedure senses the objects in an image captured in real-time by a webcam and then identifies color and information out of it. This information is processed by image processing for pick-and-place mechanism. The sorting process is based on a 2 phase operative methodology defined 1 a self-learning step where the apparatus learns to identify objects ; 2 an operative selection process where objects are detected, classified using a decisional algorithm and selected in real time. The Project deals with an automated material handling system. It aims in classifying the colored objects by colour, size, which are coming on the conveyor by picking and placing the objects in its respective pre-programmed place. Thereby eliminating the monotonous work done by human, achieving accuracy and speed in the work. The project involve sensors that senses the object’s colour, size and sends the signal to the microcontroller. The microcontroller sends signal to circuit which drives the various motors of the robotic arm to grip the object and place it in the specified location. Based upon the detection, the robotic arm moves to the specified location, releases the object and comes back to the original position [1] [2].

VISHNU R.KALE, V.A.KULKARNI

2013-07-01

419

Nuclear arms race gearing for speedup  

International Nuclear Information System (INIS)

To probe the rationale behind the big buildup in US strategic arms that is presaged by the current enhanced R and D effort - and to explore the broader, more long-term role of science and technology in the nuclear arms race - C and EN in recent months spoke with a host of experts both within and outside the defense establishment. It is a topic of incredible complexity, high controversy, and of the highest stakes imaginable - the survival of civilization. This buildup will include over the next decade, apart from the MX, a new, highly accurate, submarine-launched ballistic missile and a fleet of very large submarines to carry it; an air-launched cruise missile; a new long-range bomber; a new intermediate-range missile and a new ground-launched cruise missile, both capable of hitting targets in the Soviet Union from proposed bases in Western Europe; and a new sea-launched cruise missile that can be fired from conventional submarines or other naval vessels. To spokesmen for, and members of, the defense establishment the US buildup is prudent, even minimal. According to them, it is needed to keep the US at least on a par with the growth of Soviet strategic might which was very substantial in the 1970's and which will carry over into the 1980's with further major gains. It also is needed to keep the lid on Soviet expansionism; and it is the best way to prevent a nuclear war. To critics, the proposed buildup is the height of lunacy. According to them, the US strategic arsen According to them, the US strategic arsenal is more than adequate today. And it can continue to serve its only legitimate purpose - to deter nuclear war, no matter how much the Soviets may choose to build up their nuclear forces - with a much-more-modest modernization program

420

Cambrian stalked echinoderms show unexpected plasticity of arm construction.  

Science.gov (United States)

Feeding arms carrying coelomic extensions of the theca are thought to be unique to crinoids among stemmed echinoderms. However, a new two-armed echinoderm from the earliest Middle Cambrian of Spain displays a highly unexpected morphology. X-ray microtomographic analysis of its arms shows they are polyplated in their proximal part with a dorsal series of uniserial elements enclosing a large coelomic lumen. Distally, the arm transforms into the more standard biserial structure of a blastozoan brachiole. Phylogenetic analysis demonstrates that this taxon lies basal to rhombiferans as sister-group to pleurocystitid and glyptocystitid blastozoans, drawing those clades deep into the Cambrian. We