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Sample records for bearing pendant amine

  1. Electronic and steric influences of pendant amine groups on the protonation of molybdenum bis (dinitrogen) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Labios, Liezel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heiden, Zachariah M. [Washington State Univ., Pullman, WA (United States); Mock, Michael T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-05-04

    The synthesis of a series of PEtPNRR' (PEtPNRR' = Et₂PCH₂CH₂P(CH₂NRR')₂, R = H, R' = Ph or 2,4-difluorophenyl; R = R' = Ph or iPr) diphosphine ligands containing mono- and disubstituted pendant amine groups, and the preparation of their corresponding molybdenum bis(dinitrogen) complexes trans-Mo(N₂)₂(PMePh₂)₂(PEtPNRR') is described. In situ IR and multinuclear NMR spectroscopic studies monitoring the stepwise addition of (HOTf) to trans-Mo(N₂)₂(PMePh₂)₂(PEtPNRR') complexes in THF at -40 °C show that the electronic and steric properties of the R and R' groups of the pendant amines influence whether the complexes are protonated at Mo, a pendant amine, a coordinated N2 ligand, or a combination of these sites. For example, complexes containing mono-aryl substituted pendant amines are protonated at Mo and pendant amine to generate mono- and dicationic Mo–H species. Protonation of the complex containing less basic diphenyl-substituted pendant amines exclusively generates a monocationic hydrazido (Mo(NNH₂)) product, indicating preferential protonation of an N₂ ligand. Addition of HOTf to the complex featuring more basic diisopropyl amines primarily produces a monocationic product protonated at a pendant amine site, as well as a trace amount of dicationic Mo(NNH₂) product that contain protonated pendant amines. In addition, trans-Mo(N₂)₂(PMePh₂)₂(depe) (depe = Et₂PCH₂CH₂PEt₂) without a pendant amine was synthesized and treated with HOTf, generating a monocationic Mo(NNH₂) product. Protonolysis experiments conducted on select complexes in the series afforded trace amounts of NH₄⁺. Computational analysis of the series of trans-Mo(N₂)₂(PMePh₂)₂(PEtPNRR') complexes provides further insight into the proton affinity values of the metal center, N

  2. Well-defined (co)polypeptides bearing pendant alkyne groups

    KAUST Repository

    Zhao, Wei

    2016-03-18

    A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of acetylene-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups. This method provides an efficient way to synthesize novel alkyne-functionalized homopolypeptides (A) and copolypeptides, such as AB diblock (B: non-functionalized), ABA triblock and star-AB diblock, as well as linear and star random copolypeptides, precursors of a plethora complex macromolecular architectures by click chemistry.

  3. Well-defined (co)polypeptides bearing pendant alkyne groups

    KAUST Repository

    Zhao, Wei; Gnanou, Yves; Hadjichristidis, Nikolaos

    2016-01-01

    A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of acetylene-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups. This method provides an efficient way to synthesize novel alkyne-functionalized homopolypeptides (A) and copolypeptides, such as AB diblock (B: non-functionalized), ABA triblock and star-AB diblock, as well as linear and star random copolypeptides, precursors of a plethora complex macromolecular architectures by click chemistry.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-01

    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 νN2 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.

  5. Exploring the role of pendant amines in transition metal complexes for the reduction of N2 to hydrazine and ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Papri; Prokopchuk, Demyan E.; Mock, Michael T.

    2017-03-01

    This review examines the synthesis and acid reactivity of transition metal dinitrogen complexes bearing diphosphine ligands containing pendant amine groups in the second coordination sphere. This manuscript is a review of the work performed in the Center for Molecular Electrocatalysis. 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 (U.S. DOE), Office of Science, Office of Basic Energy Sciences. EPR studies on Fe were performed using EMSL, a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at PNNL. 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 the U.S. DOE.

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

    Science.gov (United States)

    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

    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 ΔG(‡) = 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

  7. Redox reactions of [FeFe]-hydrogenase models containing an internal amine and a pendant phosphine.

    Science.gov (United States)

    Zheng, Dehua; Wang, Mei; Chen, Lin; Wang, Ning; Sun, Licheng

    2014-02-03

    A diiron dithiolate complex with a pendant phosphine coordinated to one of the iron centers, [(μ-SCH2)2N(CH2C6H4-o-PPh2){Fe2(CO)5}] (1), was prepared and structurally characterized. The pendant phosphine is dissociated together with a CO ligand in the presence of excess PMe3, to afford [(μ-SCH2)2N(CH2C6H4-o-PPh2){Fe(CO)2(PMe3)}2] (2). Redox reactions of 2 and related complexes were studied in detail by in situ IR spectroscopy. A series of new Fe(II)Fe(I) ([3](+) and [6](+)), Fe(II)Fe(II) ([4](2+)), and Fe(I)Fe(I) (5) complexes relevant to Hox, Hox(CO), and Hred states of the [FeFe]-hydrogenase active site were detected. Among these complexes, the molecular structures of the diferrous complex [4](2+) with the internal amine and the pendant phosphine co-coordinated to the same iron center and the triphosphine diiron complex 5 were determined by X-ray crystallography. To make a comparison, the redox reactions of an analogous complex, [(μ-SCH2)2N(CH2C6H5){Fe(CO)2(PMe3)}2] (7), were also investigated by in situ IR spectroscopy in the absence or presence of extrinsic PPh3, which has no influence on the oxidation reaction of 7. The pendant phosphine in the second coordination sphere makes the redox reaction of 2 different from that of its analogue 7.

  8. Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups

    Science.gov (United States)

    Moszner, Norbert; Lukáč, Ivan

    2012-01-01

    Summary (±)-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 (λ > 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. PMID:22509202

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-10

    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.

  10. Synthesis of polynorbornene with pendant moiety bearing azide and terminal alkyne groups

    Institute of Scientific and Technical Information of China (English)

    Ze Zhang; Zhi Wei Peng; Kun Zeng Fan

    2011-01-01

    A powerful approach to the synthesis of an unprecedented polynorbornene with pendant moiety bearing azide and terminal alkyne groups is developed. Two key intermediates, namely, 3-azido-5-(2-(trimethylsilyl)ethynyl) benzyl alcohol and 4-(4-aza-tricyclo [5.2.1.02.6]dec-8-en-4-yl) benzoic acid, were optimally synthesized for convergent synthesis of the corresponding monomer.

  11. Synthesis, characterization and fluorescent properties of water-soluble glycopolymer bearing curcumin pendant residues.

    Science.gov (United States)

    Zhang, Haisong; Yu, Meng; Zhang, Hailei; Bai, Libin; Wu, Yonggang; Wang, Sujuan; Ba, Xinwu

    2016-08-01

    Curcumin is a potential natural anticancer drug with low oral bioavailability because of poor water solubility. The aqueous solubility of curcumin is enhanced by means of modification with the carbohydrate units. Polymerization of the curcumin-containing monomer with carbohydrate-containing monomer gives the water-soluble glycopolymer bearing curcumin pendant residues. The obtained copolymers (P1 and P2) having desirable water solubility were well-characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), UV-Vis absorption spectroscopy, and photoluminescence spectroscopy. The copolymer P2 with a molar ratio of 1:6 (curcumin/carbohydrate) calculated from the proton NMR results exhibits a similar anticancer activity compared to original curcumin, which may serve as a potential chemotherapeutic agent in the field of anticancer medicine.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Gaicen; Fan, Xiaoshan; Xu, Bingcan; Zhang, Delong; Hu, Zhiguo, E-mail: zghu@htu.cn

    2014-10-01

    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 {sup 1}H nuclear magnetic resonance ({sup 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{sup −4} mg/mL and 3.9 × 10{sup −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. - Highlights: • The method to synthesize PLA-b–PHMTYO-b–PLA is relatively facile and efficient. • PLA-b–PHMTYO-b–PLA self-assembles into spherical micelles with low CMC in water. • PLA-b–PHMTYO-b–PLA exhibits better biocompatibility and biodegradability.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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. - Highlights: • The method to synthesize PLA-b–PHMTYO-b–PLA is relatively facile and efficient. • PLA-b–PHMTYO-b–PLA self-assembles into spherical micelles with low CMC in water. • PLA-b–PHMTYO-b–PLA exhibits better biocompatibility and biodegradability

  14. Synthesis, X-ray crystal structures, and phosphate ester cleavage properties of bis(2-pyridylmethyl)amine copper(II) complexes with guanidinium pendant groups.

    Science.gov (United States)

    Belousoff, Matthew J; Tjioe, Linda; Graham, Bim; Spiccia, Leone

    2008-10-06

    Three new derivatives of bis(2-pyridylmethyl)amine (DPA) featuring ethylguanidinium (L (1)), propylguanidinium (L (2)), or butylguanidinium (L (3)) pendant groups have been prepared by the reaction of N, N- bis(2-pyridylmethyl)alkane-alpha,omega-diamines with 1 H-pyrazole-1-carboxamidine hydrochloride. The corresponding mononuclear copper(II) complexes were prepared by reacting the ligands with copper(II) nitrate and were isolated as [Cu(LH (+))(OH 2)](ClO 4) 3. xNaClO 4. yH 2O ( C1: L = L (1), x = 2, y = 3; C2: L = L (2), x = 2, y = 4; C3: L = L (3), x = 1, y = 0) following cation exchange purification. Recrystallization yielded crystals of composition [Cu(LH (+))(X)](ClO 4) 3.X ( C1': L = L (1), X = MeOH; C2': L = L (2), X = H 2O; C3': L = L (3), X = H 2O), which were suitable for X-ray crystallography. The crystal structures of C1', C2', and C3' indicate that the DPA moieties of the ligands coordinate to the copper(II) centers in a meridional fashion, with a water or methanol molecule occupying the fourth basal position. Weakly bound perchlorate anions located in the axial positions complete the distorted octahedral coordination spheres. The noncoordinating, monoprotonated guanidinium groups project away from the Cu(II)-DPA units and are involved in extensive charge-assisted hydrogen-bonding interactions with cocrystallized water/methanol molecules and perchlorate anions within the crystal lattices. The copper(II) complexes were tested for their ability to promote the cleavage of two model phosphodiesters, bis( p-nitrophenyl)phosphate (BNPP) and uridine-3'- p-nitrophenylphosphate (UpNP), as well as supercoiled plasmid DNA (pBR 322). While the presence of the guanidine pendants was found to be detrimental to BNPP cleavage efficiency, the functionalized complexes were found to cleave plasmid DNA and, in some cases, the model ribose phosphate diester, UpNP, at a faster rate than the parent copper(II) complex of DPA.

  15. Two pathways for electrocatalytic oxidation of hydrogen by a nickel bis(diphosphine) complex with pendant amines in the second coordination sphere.

    Science.gov (United States)

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

    2013-07-03

    A nickel bis(diphosphine) complex containing pendant amines in the second coordination sphere, [Ni(P(Cy)2N(t-Bu)2)2](BF4)2 (P(Cy)2N(t-Bu)2 = 1,5-di(tert-butyl)-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane), is an electrocatalyst for hydrogen oxidation. The addition of hydrogen to the Ni(II) complex gives three isomers of the doubly protonated Ni(0) complex [Ni(P(Cy)2N(t-Bu)2H)2](BF4)2. Using the pKa values and Ni(II/I) and Ni(I/0) redox potentials in a thermochemical cycle, the free energy of hydrogen addition to [Ni(P(Cy)2N(t-Bu)2)2](2+) was determined to be -7.9 kcal mol(-1). The catalytic rate observed in dry acetonitrile for the oxidation of H2 depends on base size, with larger bases (NEt3, t-BuNH2) resulting in much slower catalysis than n-BuNH2. The addition of water accelerates the rate of catalysis by facilitating deprotonation of the hydrogen addition product before oxidation, especially for the larger bases NEt3 and t-BuNH2. This catalytic pathway, where deprotonation occurs prior to oxidation, leads to an overpotential that is 0.38 V lower compared to the pathway where oxidation precedes proton movement. Under the optimal conditions of 1.0 atm H2 using n-BuNH2 as a base and with added water, a turnover frequency of 58 s(-1) is observed at 23 °C.

  16. Data on synthesis and thermo-mechanical properties of stimuli-responsive rubber materials bearing pendant anthracene groups.

    Science.gov (United States)

    Manhart, Jakob; Ayalur-Karunakaran, Santhosh; Radl, Simone; Oesterreicher, Andreas; Moser, Andreas; Ganser, Christian; Teichert, Christian; Pinter, Gerald; Kern, Wolfgang; Griesser, Thomas; Schlögl, Sandra

    2016-12-01

    The photo-reversible [4πs+4πs] cycloaddition reaction of pendant anthracene moieties represents a convenient strategy to impart wavelength dependent properties into hydrogenated carboxylated nitrile butadiene rubber (HXNBR) networks. The present article provides the 1 H NMR data on the reaction kinetics of the side chain functionalization of HXNBR. 2-(Anthracene-9-yl)oxirane with reactive epoxy groups is covalently attached to the polymer side chain of HXNBR via ring opening reaction between the epoxy and the carboxylic groups. Along with the identification, 1 H NMR data on the quantification of the attached functional groups are shown in dependence on reaction time and concentration of 2-(anthracene-9-yl)oxirane. Changes in the modification yield are reflected in the mechanical properties and DMA data of photo-responsive elastomers are illustrated in dependence on the number of attached anthracene groups. DMA curves over repeated cycles of UV induced crosslinking ( λ >300 nm) and UV induced cleavage ( λ =254 nm) are further depicted, demonstrating the photo-reversibility of the thermo-mechanical properties. Interpretation and discussion of the data are provided in "Design and application of photo-reversible elastomer networks by using the [4πs+4πs] cycloaddition reaction of pendant anthracene groups" (Manhart et al., 2016) [1].

  17. Data on synthesis and thermo-mechanical properties of stimuli-responsive rubber materials bearing pendant anthracene groups

    Directory of Open Access Journals (Sweden)

    Jakob Manhart

    2016-12-01

    Full Text Available The photo-reversible [4πs+4πs] cycloaddition reaction of pendant anthracene moieties represents a convenient strategy to impart wavelength dependent properties into hydrogenated carboxylated nitrile butadiene rubber (HXNBR networks. The present article provides the 1H NMR data on the reaction kinetics of the side chain functionalization of HXNBR. 2-(Anthracene-9-yloxirane with reactive epoxy groups is covalently attached to the polymer side chain of HXNBR via ring opening reaction between the epoxy and the carboxylic groups. Along with the identification, 1H NMR data on the quantification of the attached functional groups are shown in dependence on reaction time and concentration of 2-(anthracene-9-yloxirane. Changes in the modification yield are reflected in the mechanical properties and DMA data of photo-responsive elastomers are illustrated in dependence on the number of attached anthracene groups. DMA curves over repeated cycles of UV induced crosslinking (λ>300 nm and UV induced cleavage (λ=254 nm are further depicted, demonstrating the photo-reversibility of the thermo-mechanical properties. Interpretation and discussion of the data are provided in “Design and application of photo-reversible elastomer networks by using the [4πs+4πs] cycloaddition reaction of pendant anthracene groups” (Manhart et al., 2016 [1].

  18. Synthesis, physico-chemical and antimicrobial screening studies on 14 and 16-membered hexaazamacrocyclic complexes bearing pendant amine groups

    Directory of Open Access Journals (Sweden)

    Shakir Mohammad

    2006-01-01

    Full Text Available The synthesis and characterization of a series of 14 and 16-membered hexaazamacrocyclic complexes, which were obtained via template condensation of 1,2- diaminoethane or 1,3-diaminopropane, formaldehyde and hydrazine hydrate in the presence of first row transition metal salts are reported. Complexes of the types, [ML¹(NO32]; [CuL¹](NO32 and [ML²Cl2]; [CuL²]Cl2 (where M = Co(II, Ni(II and Zn(II, were obtained. Elemental analyses, IR spectra, ¹H NMR, EPR, UV-Vis, magnetic susceptibility and conductivity measurements have ascertained the overall geometry and stereochemistry of the complexes. An octahedral geometry has been suggested for all the complexes, except for copper compounds, in which the metal centre coordinates to the four nitrogen atoms of macrocyclic ligand in a square planar fashion. These complexes were screened against different fungi and bacteria in vitro and were found to be potentially active in the concentration 5 mg mL-1.

  19. Novel Synthetic Monothiourea Aspirin Derivatives Bearing Alkylated Amines as Potential Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Norsyafikah Asyilla Nordin

    2017-01-01

    Full Text Available A new series of aspirin bearing alkylated amines moieties 1–12 were synthesised by reacting isothiocyanate with a series of aniline derivatives in overall yield of 16–56%. The proposed structures of all the synthesised compounds were confirmed using elemental analysis, FTIR, and 1H and  13C NMR spectroscopy. All compounds were evaluated for antibacterial activities against E. coli and S. aureus via turbidimetric kinetic and Kirby Bauer disc diffusion method. Compound 5 bearing meta -CH3 substituent showed the highest relative inhibition zone diameter against tested bacteria compared to ortho and para substituent. Furthermore, aspirin derivatives bearing shorter chains exhibited better bacterial inhibition than longer alkyl chains.

  20. Thermo- and pH-Responsive Copolymers Bearing Cholic Acid and Oligo(ethylene glycol) Pendants: Self-Assembly and pH-Controlled Release.

    Science.gov (United States)

    Jia, Yong-Guang; Zhu, X X

    2015-11-11

    A family of block and random copolymers of norbornene derivatives bearing cholic acid and oligo(ethylene glycol) pendants were prepared in the presence of Grubbs' catalyst. The phase transition temperature of the copolymers in aqueous solutions may be tuned by the variation of comonomer ratios and pH values. Both types of copolymers formed micellar nanostructures with a hydrophilic poly(ethylene glycol) shell and a hydrophobic core containing cholic acid residues. The micellar size increased gradually with increasing pH due to the deprotonation of the carboxylic acid groups. These micelles were capable of encapsulating hydrophobic compounds such as Nile Red (NR). A higher hydrophobicity/hydrophilicity ratio in both copolymers resulted in a higher loading capacity for NR. With similar molecular weights and monomer compositions, the block copolymers showed a higher loading capacity for NR than the random copolymers. The NR-loaded micelles exhibited a pH-triggered release behavior. At pH 7.4 within 96 h, the micelles formed by the block and random of copolymers released 56 and 97% NR, respectively. Therefore, these micelles may have promise for use as therapeutic nanocarriers in drug delivery systems.

  1. Cu(ll) mediated ATRP of MMA by using a novel tetradentate amine ligand with oligo(ethylene glycol) pendant groups

    NARCIS (Netherlands)

    Becer, C.R.; Hoogenboom, R.; Founier, D.; Schubert, U.S.

    2007-01-01

    A novel tetradentate amine ligand namely N,N,N,N,N;,N;-hexaoligo(ethylene glycol) triethylenetetramine (HOEGTETA) was employed in the homogenous ATRP of MMA in anisole using CuBr and CuBr2 as the catalyst and ethyl 2-bromoisobutyrate (EBiB) as an initiator. The effect of the polymerization

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

    Directory of Open Access Journals (Sweden)

    K. S. SIDDIQI

    2004-09-01

    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.

  3. Effect of pendant group length upon metal ion complexation in acetonitrile by di-ionized calix[4]arenes bearing two dansyl fluorophores.

    Science.gov (United States)

    Ocak, Ummühan; Ocak, Miraç; Shen, Xin; Surowiec, Kazimierz; Bartsch, Richard A

    2009-11-01

    A series of three di-ionizable calix[4]arenes with two pendant dansyl (1-dimethylaminonaphthalene-5-sulfonyl) groups linked to the lower rims was synthesized. Structures of the three ligands were identical except for the length of the spacers which connected the two dansyl groups to the calix[4]arene scaffold. Following conversion of the ligands into their di-ionized di(tetramethylammonium) salts, absorption and emission spectrophotometry were utilized to probe the influence of metal cation (Li+, Na+, K+, Rb+, Cs+, Mg2+, Ca2+, Sr2+, Ba2+, Ag+, Cd2+, Co2+, Fe2+, Hg2+, Mn2+, Pb2+, Zn2+ and Fe3+) complexation in acetonitrile. Upon complexation with these metal cations, emission spectra underwent marked red shifts and quenching of the dansyl group fluorescence for the di-ionized ligand with the shortest spacer. A similar effect was noted for the di-ionized ligand with an intermediate spacer for all of the metal ions, except Ba2+. For the di-ionized ligand with the longest spacer, the metal cations showed different effects on the emission spectrum. Li+, Mg2+, Ca2+ and Ba2+ caused enhancement of emission intensity with a red shift. Other metal cations produce quenching with red shifts in the emission spectra. Transition metal cations interacted strongly with all three di-ionized ligands. In particular, Fe3+ and Hg2+ caused greater than 99% quenching of the dansyl fluorescence in the di-ionized ligands.

  4. 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)

    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

    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.)

  5. The Activity of [60]Fullerene Derivatives Bearing Amine and Carboxylic Solubilizing Groups against Escherichia coli: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Dmitry G. Deryabin

    2014-01-01

    Full Text Available We report a comparative investigation of the antibacterial activity of two water-soluble fullerene derivatives bearing protonated amine (AF and deprotonated carboxylic (CF groups appended to the fullerene cage via organic linkers. The negatively charged fullerene derivative CF showed no tendency to bind to the bacterial cells and, consequently, no significant antibacterial activity. In contrast, the compound AF loaded with cationic groups showed strong and partially irreversible binding to the negatively charged Escherichia coli K12 TG1 cells and to human erythrocytes, also possessing negative zeta potential. Adsorption of AF on the bacterial surface was visualized by atomic force microscopy revealing the formation of specific clusters (AF aggregates surrounding the bacterial cell. Incubation of E. coli K12 TG1 with AF led to a dose-dependent bactericidal effect with LD50 = 79.1 µM. The presence of human erythrocytes in the test medium decreased the AF antibacterial activity. Thus we reveal that the water-soluble cationic fullerene derivative AF possesses promising antibacterial activity, which might be utilized in the development of novel types of chemical disinfectants.

  6. Peptidyl prolyl isomerase Pin1-inhibitory activity of D-glutamic and D-aspartic acid derivatives bearing a cyclic aliphatic amine moiety.

    Science.gov (United States)

    Nakagawa, Hidehiko; Seike, Suguru; Sugimoto, Masatoshi; Ieda, Naoya; Kawaguchi, Mitsuyasu; Suzuki, Takayoshi; Miyata, Naoki

    2015-12-01

    Pin1 is a peptidyl prolyl isomerase that specifically catalyzes cis-trans isomerization of phosphorylated Thr/Ser-Pro peptide bonds in substrate proteins and peptides. Pin1 is involved in many important cellular processes, including cancer progression, so it is a potential target of cancer therapy. We designed and synthesized a novel series of Pin1 inhibitors based on a glutamic acid or aspartic acid scaffold bearing an aromatic moiety to provide a hydrophobic surface and a cyclic aliphatic amine moiety with affinity for the proline-binding site of Pin1. Glutamic acid derivatives bearing cycloalkylamino and phenylthiazole groups showed potent Pin1-inhibitory activity comparable with that of known inhibitor VER-1. The results indicate that steric interaction of the cyclic alkyl amine moiety with binding site residues plays a key role in enhancing Pin1-inhibitory activity. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Polyethene with pendant fullerene moieties

    NARCIS (Netherlands)

    Zhang, XC; Sieval, AB; Hummelen, JC; Hessen, B; Zhang, Xiaochun

    2005-01-01

    Polyethene with fullerene moieties pendant on short-chain branches was prepared by the catalytic copolymerisation of ethene and a fullerene-containing vinylic comonomer, yielding polyethene copolymers containing up to 25 wt% of C-60.

  8. Synthesis and Reactivity of Tripodal Complexes Containing Pendant Bases

    Energy Technology Data Exchange (ETDEWEB)

    Blacquiere, Johanna M.; Pegis, Michael L.; Raugei, Simone; Kaminsky, Werner; Forget, Amelie; Cook, Sarah; Taguchi, Taketo; Borovik, Andrew S.; Mayer, James M.

    2014-09-02

    The synthesis of a new tripodal ligand family is reported, with tertiary-amine groups in the second-coordination sphere. The ligands are tris(amido)amine derivatives, with the pendant amines attached via a peptide coupling strategy. They were designed to be used in new catalysts for the oxygen reduction reaction (ORR), in which the pendant acid/base group could improve catalyst performance. Two members of the new ligand family were each metallated with Co(II) and Zn(II) to afford trigonal monopyramidal complexes. Reaction of the cobalt complexes, [Co(L)]-, with dioxygen reversibly generates a small amount of a Co(III)-superoxo species, which was characterized by EPR. Protonation of the zinc complex Zn[N{CH2CH2NC(O)CH2N(CH2Ph)2}3)-– ([Zn(TNBn)]-) with one equivalent of acid occurs with displacement and dissociation of an amide ligand. Addition of excess acid to the any of the complexes [M(L)]- results in complete proteolysis and formation of the ligands H3L. This decomposition limits the use of these complexes as catalysts for the ORR. An alternative ligand with two pyridyl arms was also prepared but could not be metallated. These studies highlight the importance of stability of the primary-coordination sphere of ORR electrocatalysts to both oxidative and acidic conditions. 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.

  9. Novel polyketones with pendant imidazolium groups as nanodispersants of hydrophobic antibiotics

    NARCIS (Netherlands)

    Araya-Hermosilla, Esteban; Orellana, Sandra L.; Toncelli, Claudio; Picchioni, Francesco; Moreno-Villoslada, Ignacio

    2015-01-01

    In this work, we present a new method to nanodisperse the pH-sensitive antibiotics oxolinic acid and flumequine by the use of a pH-sensitive synthetic polyketone derivative with amphiphilic characteristics. The pH-sensitive polymer bears imidazolium residues on pendant groups as weak acids, and its

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

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    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...

  11. Electroactive Polyurea Bearing Oligoaniline Pendants: Electrochromic and Anticorrosive Properties

    Science.gov (United States)

    2014-12-26

    3] Cheng YJ, Yang SH, Hsu CS. Chem Rev 2009;109:5868e923. [4] Gu H, Guo J, Yan X, Wei H, Zhang X, Liu J, et al. Polymer 2014;55:4405e19. [5] Bigg DM...Reddy KN. Modern electrochemistry. New York: John Wiley and Sons; 1976. p. 622. [57] Bockris JOM, Reddy AK. Modern electrochemistry: an introduction to

  12. Amine synergism in uranium extraction

    International Nuclear Information System (INIS)

    Rinelli, G.; Abbruzzese, C.

    1977-01-01

    Commercial products based on C 8 to C 12 tertiary amine mixtures are now widely used in the solvent extraction of uranium from sulphuric pregnant solutions. The satisfactory results generally obtained have never required an analysis of the synergistic effects of amine combinations similar to that carried out for the organo-phosphorus compounds. In the research described the increase in the extraction power of an organic phase composed of an amine binary mixture was studied with regard to an aqueous solution from the sulphuric acid treatment of uranium ore. On the basis of the experimental results obtained, it is possible to select the best composition of the amine mixture to ensure a percentage increase in uranium recovery. Bearing in mind the tendency for the yellow-cake price to rise, the study is considered to be a useful contribution in the context of commercial products currently available on the market. (author)

  13. In situ Generated Ruthenium Catalyst Systems Bearing Diverse N-Heterocyclic Carbene Precursors for Atom-Economic Amide Synthesis from Alcohols and Amines.

    Science.gov (United States)

    Cheng, Hua; Xiong, Mao-Qian; Cheng, Chuan-Xiang; Wang, Hua-Jing; Lu, Qiang; Liu, Hong-Fu; Yao, Fu-Bin; Chen, Cheng; Verpoort, Francis

    2018-02-16

    The transition-metal-catalyzed direct synthesis of amides from alcohols and amines is herein demonstrated as a highly environmentally benign and atom-economic process. Among various catalyst systems, in situ generated N-heterocyclic carbene (NHC)-based ruthenium (Ru) halide catalyst systems have been proven to be active for this transformation. However, these existing catalyst systems usually require an additional ligand to achieve satisfactory results. In this work, through extensive screening of a diverse variety of NHC precursors, we discovered an active in situ catalyst system for efficient amide synthesis without any additional ligand. Notably, this catalyst system was found to be insensitive to the electronic effects of the substrates, and various electron-deficient substrates, which were not highly reactive with our previous catalyst systems, could be employed to afford the corresponding amides efficiently. Furthermore, mechanistic investigations were performed to provide a rationale for the high activity of the optimized catalyst system. NMR-scale reactions indicated that the rapid formation of a Ru hydride intermediate (signal at δ=-7.8 ppm in the 1 H NMR spectrum) after the addition of the alcohol substrate should be pivotal in establishing the high catalyst activity. Besides, HRMS analysis provided possible structures of the in situ generated catalyst system. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. The shape, stability and breakage of pendant liquid bridges

    Science.gov (United States)

    Padday, J. F.; Pétré, G.; Rusu, C. G.; Gamero, J.; Wozniak, G.

    1997-12-01

    Pendant liquid bridges are defined as pendant drops supporting a solid axisymmetric endplate at their lower end. The stability and shape properties of such bridges are defined in terms of the capillary properties of the system and of the mass and radius of the lower free-floating endplate. The forces acting in the pendant liquid bridge are defined exactly and expressed in dimensionless form. Numerical analysis has been used to derive the properties of a given bridge and it is shown that as the bridge grows by adding more liquid to the system a maximum volume is reached. At this maximum volume, the pendant bridge becomes unstable with the length of the bridge increasing spontaneously and irreversibly at constant volume. Finally the bridge breaks with the formation of a satellite drop or an extended thread. The bifurcation and breakage processes have been recorded using a high-speed video camera with a digital recording rate of up to 6000 frames per second. The details of the shape of the bridge bifurcation and breakage for many pendant bridge systems have been recorded and it is shown that satellite drop formation after rupture is not always viscosity dependent. Bifurcation and breakage in simulated low gravity demonstrated that breakage was very nearly symmetrical about a plane through the middle of the pendant bridge.

  15. Enantioselective Direct α-Amination of Aldehydes via a Photoredox Mechanism: A Strategy for Asymmetric Amine Fragment Coupling

    OpenAIRE

    Cecere, Giuseppe; Koenig, Christian M.; Alleva, Jennifer L.; MacMillan, David W. C.

    2013-01-01

    The direct, asymmetric α-amination of aldehydes has been accomplished via a combination of photoredox and organocatalysis. Photon-generated, nitrogen-centered radicals undergo enantioselective α-addition to catalytically formed chiral enamines to directly produce stable α-amino aldehyde adducts bearing synthetically useful amine substitution patterns. Incorporation of a photolabile group on the amine precursor obviates the need to employ a photoredox catalyst in this transformation. Important...

  16. Polythiophenes Comprising Conjugated Pendants for Polymer Solar Cells: A Review

    Directory of Open Access Journals (Sweden)

    Hsing-Ju Wang

    2014-03-01

    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.

  17. Amines, Astrocytes and Arousal

    OpenAIRE

    Bazargani, N.; Attwell, D.

    2017-01-01

    Amine neurotransmitters, such as noradrenaline, mediate arousal, attention, and reward in the CNS. New data suggest that, from flies to mammals, a major mechanism for amine transmitter action is to raise astrocyte [Ca2+]i and release gliotransmitters that modulate neuronal activity and behavior.

  18. Amine Functionalized Porous Network

    KAUST Repository

    Eddaoudi, Mohamed; Guillerm, Vincent; Weselinski, Lukasz Jan; Alkordi, Mohamed H.; Mohideen, Mohamed Infas Haja; Belmabkhout, Youssef

    2015-01-01

    Amine groups can be introduced in porous materials by a direct (one pot) or post-synthetic modification (PSM) process on aldehyde groups, and the resulting porous materials have increased gas affinity.

  19. Amine Functionalized Porous Network

    KAUST Repository

    Eddaoudi, Mohamed

    2015-05-28

    Amine groups can be introduced in porous materials by a direct (one pot) or post-synthetic modification (PSM) process on aldehyde groups, and the resulting porous materials have increased gas affinity.

  20. Incorporation of Cyclotriphosphazene as Pendant Groups to the Sago Network

    International Nuclear Information System (INIS)

    Zainab Ngaini; Khairul Aidil Azlin Abd Rahman; Nazlina Shaari; Hasnain Hussain; Norhaizat Sundin; Jingxin, T.

    2012-01-01

    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)

  1. Nickel-Catalyzed Synthesis of Primary Aryl and Heteroaryl Amines via C–O Bond Cleavage

    KAUST Repository

    Yue, Huifeng

    2017-03-13

    A nickel-catalyzed protocol for the conversion of aryl and heteroaryl alcohol derivatives to primary and secondary aromatic amines via C(sp2)-O bond cleavage is described. The new amination protocol can be applied to a range of substrates bearing diverse functional groups and uses readily available benzophenone imines as an effective nitrogen source.

  2. Nickel-Catalyzed Synthesis of Primary Aryl and Heteroaryl Amines via C–O Bond Cleavage

    KAUST Repository

    Yue, Huifeng; Guo, Lin; Liu, Xiangqian; Rueping, Magnus

    2017-01-01

    A nickel-catalyzed protocol for the conversion of aryl and heteroaryl alcohol derivatives to primary and secondary aromatic amines via C(sp2)-O bond cleavage is described. The new amination protocol can be applied to a range of substrates bearing diverse functional groups and uses readily available benzophenone imines as an effective nitrogen source.

  3. Bearing system

    Science.gov (United States)

    Kapich, Davorin D.

    1987-01-01

    A bearing system includes backup bearings for supporting a rotating shaft upon failure of primary bearings. In the preferred embodiment, the backup bearings are rolling element bearings having their rolling elements disposed out of contact with their associated respective inner races during normal functioning of the primary bearings. Displacement detection sensors are provided for detecting displacement of the shaft upon failure of the primary bearings. Upon detection of the failure of the primary bearings, the rolling elements and inner races of the backup bearings are brought into mutual contact by axial displacement of the shaft.

  4. Effect of thiol pendant conjugates on plasmid DNA binding, release, and stability of polymeric delivery vectors.

    Science.gov (United States)

    Bacalocostantis, Irene; Mane, Viraj P; Kang, Michael S; Goodley, Addison S; Muro, Silvia; Kofinas, Peter

    2012-05-14

    Polymers have attracted much attention as potential gene delivery vectors due to their chemical and structural versatility. However, several challenges associated with polymeric carriers, including low transfection efficiencies, insufficient cargo release, and high cytotoxicity levels have prevented clinical implementation. Strong electrostatic interactions between polymeric carriers and DNA cargo can prohibit complete cargo release within the cell. As a result, cargo DNA never reaches the cell's nucleus where gene expression takes place. In addition, highly charged cationic polymers have been correlated with high cytotoxicity levels, making them unsuitable carriers in vivo. Using poly(allylamine) (PAA) as a model, we investigated how pH-sensitive disulfide cross-linked polymer networks can improve the delivery potential of cationic polymer carriers. To accomplish this, we conjugated thiol-terminated pendant chains onto the primary amines of PAA using 2-iminothiolane, developing three new polymer vectors with 5, 13, or 20% thiol modification. Unmodified PAA and thiol-conjugated polymers were tested for their ability to bind and release plasmid DNA, their capacity to protect genetic cargo from enzymatic degradation, and their potential for endolysosomal escape. Our results demonstrate that polymer-plasmid complexes (polyplexes) formed by the 13% thiolated polymer demonstrate the greatest delivery potential. At high N/P ratios, all thiolated polymers (but not unmodified counterparts) were able to resist decomplexation in the presence of heparin, a negatively charged polysaccharide used to mimic in vivo polyplex-protein interactions. Further, all thiolated polymers exhibited higher buffering capacities than unmodified PAA and, therefore, have a greater potential for endolysosomal escape. However, 5 and 20% thiolated polymers exhibited poor DNA binding-release kinetics, making them unsuitable carriers for gene delivery. The 13% thiolated polymers, on the other hand

  5. Synthesis and Catalytic Activity of [Cp′Co(COD)] Complexes Bearing Pendant N-Containing Groups

    Czech Academy of Sciences Publication Activity Database

    Thiel, I.; Lamač, Martin; Jiao, H.; Spannenberg, A.; Hapke, M.

    2013-01-01

    Roč. 32, č. 11 (2013), s. 3415-3418 ISSN 0276-7333 R&D Projects: GA ČR GPP207/10/P200 Institutional support: RVO:61388955 Keywords : FUNCTIONALIZED CYCLOPENTADIENYL LIGANDS * SANDWICH COBALT COMPLEXES * METALLOCENE COMPLEXES Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.253, year: 2013

  6. Tris{2-[(2-aminobenzylideneamino]ethyl}amine

    Directory of Open Access Journals (Sweden)

    Perla Elizondo Martínez

    2010-12-01

    Full Text Available The title Schiff base, C27H33N7, is a tripodal amine displaying C3 symmetry, with the central tertiary N atom lying on the threefold crystallographic axis. The N—CH2—CH2—N conformation of the pendant arms is gauche [torsion angle = 76.1 (3°], which results in a claw-like molecule, with the terminal aniline groups wrapped around the symmetry axis. The lone pair of the apical N atom is clearly oriented inwards towards the cavity, and should thus be chemically inactive. The amine NH2 substituents lie in the plane of the benzene ring to which they are bonded. With such an arrangement, one amine H atom forms an S(6 motif through a weak N—H...N hydrogen bond with the imine N atom, while the other is engaged in an intermolecular N—H...π contact involving the benzene ring of a neighbouring molecule related by inversion. The benzene rings also participate in an intramolecular C—H...π contact of similar strength. In the crystal structure, molecules are separated by empty voids (ca 5% of the crystal volume, although the crystal seems to be unsolvated.

  7. Fluorinated Amine Stereotriads via Allene Amination.

    Science.gov (United States)

    Liu, Lu; Gerstner, Nels C; Oxtoby, Lucas J; Guzei, Ilia A; Schomaker, Jennifer M

    2017-06-16

    The incorporation of fluorine into organic scaffolds often improves the bioactivity of pharmaceutically relevant compounds. C-F/C-N/C-O stereotriad motifs are prevalent in antivirals, neuraminidase inhibitors, and modulators of androgen receptors, but are challenging to install. An oxidative allene amination strategy using Selectfluor rapidly delivers triply functionalized triads of the form C-F/C-N/C-O, exhibiting good scope and diastereoselectivity for all syn products. The resulting stereotriads are readily transformed into fluorinated pyrrolidines and protected α-, β-, and γ-amino acids.

  8. Nitrile-functionalized tertiary amines as highly efficient and reversible SO2 absorbents

    International Nuclear Information System (INIS)

    Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk; Lee, Hyunjoo; Kim, Hoon Sik; Lee, Je Seung

    2014-01-01

    Highlights: • Nitrile-functionalized tertiary amines physically and reversibly absorb SO 2 . • Tertiary alkanolamines chemically and irreversibly absorb SO 2 through OH group. • SO 2 absorption modes were studied by spectroscopy and computational calculations. -- Abstract: Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO 2 absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption–desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO 2 through oxygen atom, forming an ionic compound with a covalently bound -OSO 2 − group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO 2 through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities

  9. Nitrile-functionalized tertiary amines as highly efficient and reversible SO{sub 2} absorbents

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Lee, Hyunjoo [Clean Energy Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Kim, Hoon Sik, E-mail: khs2004@khu.ac.kr [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Lee, Je Seung, E-mail: leejs70@khu.ac.kr [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

    2014-01-15

    Highlights: • Nitrile-functionalized tertiary amines physically and reversibly absorb SO{sub 2}. • Tertiary alkanolamines chemically and irreversibly absorb SO{sub 2} through OH group. • SO{sub 2} absorption modes were studied by spectroscopy and computational calculations. -- Abstract: Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO{sub 2} absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption–desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO{sub 2} through oxygen atom, forming an ionic compound with a covalently bound -OSO{sub 2}{sup −} group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO{sub 2} through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities.

  10. Modular functionalization of allenes to aminated stereotriads.

    Science.gov (United States)

    Adams, Christopher S; Boralsky, Luke A; Guzei, Ilia A; Schomaker, Jennifer M

    2012-07-04

    Nitrogen-containing stereotriads, compounds with three adjacent stereodefined carbons, are commonly found in biologically important molecules. However, the preparation of molecules bearing these motifs can be challenging. Herein, we describe a modular oxidation protocol which converts a substituted allene to a triply functionalized amine of the form C-X/C-N/C-Y. The key step employs a Rh-catalyzed intramolecular conversion of the allene to a strained bicyclic methylene aziridine. This reactive intermediate is further elaborated to the target products, often in one reaction vessel and with effective transfer of the axial chirality of the allene to point chirality in the stereotriad.

  11. Controlled Synthesis of Fluorinated Copolymers with Pendant Sulfonates

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2008-01-01

    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 ...

  12. Characterization of particulate amines

    International Nuclear Information System (INIS)

    Gundel, L.A.; Chang, S.G.; Clemenson, M.S.; Markowitz, S.S.; Novakov, T.

    1979-01-01

    The reduced nitrogen compounds associated with ambient particulate matter are chemically characterized by means of ESCA and proton activation analysis. Ambient particulate samples collected on silver filters in Berkeley, California were washed with water and organic solvents, and ESCA and proton activation analysis were performed in order to determine the composition of various nitrogen compounds and the total nitrogen content. It is found that 85% of the amines originally present in ambient particulate matter can be removed by water extraction, whereas the ammonium and nitrate are completely removed. An observed increase in ammonium ion in the extract, compared with its concentration in the original sample, coupled with the commensurate decrease in amine concentration, is attributed to the hydrolysis of amide groups, which may cause analytical methods based on extraction to yield erroneous results

  13. Nitrile-functionalized tertiary amines as highly efficient and reversible SO2 absorbents.

    Science.gov (United States)

    Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk; Lee, Hyunjoo; Kim, Hoon Sik; Lee, Je Seung

    2014-01-15

    Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO2 absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption-desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO2 through oxygen atom, forming an ionic compound with a covalently bound OSO2(-) group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO2 through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Evolution des acides aminés libres dans le moût de raisin sous l'action des levures de fleur

    Directory of Open Access Journals (Sweden)

    M.C. POLO

    1974-03-01

    La plus grande partie des travaux qui existent dans la bibliographie sur la teneur en acides aminés du raisin pendant l'évolution de la maturation ainsi que sur les teneurs des moûts et des vins de différents pays, ont été réalisés par chromatographie sur papier ou en utilisant des méthodes microbiologiques ou colorimétriques.

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

    International Nuclear Information System (INIS)

    Fish, D.

    1996-01-01

    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

  16. The economics of amine usage

    International Nuclear Information System (INIS)

    Fountain, M.J.

    1994-01-01

    The EPRI computer programm, 'Aminemod', a PWR chemistry model, has been used to compare the technical advantages of the 'advanced' amines, ethanolamine, 1,2 diaminoethane and 5 aminopentanol over morpholine in generating an elevated pH in the moisture separator and the economics of using these amines has been assessed by using an MS Excel spreadsheet in conjunction with Aminemod. The advanced amines are capable of achieving 1 pH unit above neutrality, the EPRI target for prevention of erosion-corrison, at acceptable cost and, compared with 'conventional' amines, at considerably reduced ionic load on the condensate polisher. The exercise demonstrates that it is essential to evaluate the effect of an amine dosing regime on the total operating cost and that it is not possible to prejudge the economic outcome on the basis of an amine's purchase price. (orig.)

  17. Journal bearing

    Science.gov (United States)

    Menke, John R.; Boeker, Gilbert F.

    1976-05-11

    1. An improved journal bearing comprising in combination a non-rotatable cylindrical bearing member having a first bearing surface, a rotatable cylindrical bearing member having a confronting second bearing surface having a plurality of bearing elements, a source of lubricant adjacent said bearing elements for supplying lubricant thereto, each bearing element consisting of a pair of elongated relatively shallowly depressed surfaces lying in a cylindrical surface co-axial with the non-depressed surface and diverging from one another in the direction of rotation and obliquely arranged with respect to the axis of rotation of said rotatable member to cause a flow of lubricant longitudinally along said depressed surfaces from their distal ends toward their proximal ends as said bearing members are rotated relative to one another, each depressed surface subtending a radial angle of less than 360.degree., and means for rotating said rotatable bearing member to cause the lubricant to flow across and along said depressed surfaces, the flow of lubricant being impeded by the non-depressed portions of said second bearing surface to cause an increase in the lubricant pressure.

  18. Polystyrene with pendant mixed functional ruthenium(II)-terpyridine complexes

    NARCIS (Netherlands)

    Heller, M.; Schubert, U.S.

    2002-01-01

    A vinyl substituted 2,2:6,2-terpyridine and a mixed, bifunctional ruthenium(II)-terpyridine complex bearing a vinyl and a hydroxymethyl group are utilized as comonomers for radical copolymerization with styrene. The resulting polymers are characterized by means of UV-vis spectroscopy and gel

  19. GAS BEARING

    Science.gov (United States)

    Skarstrom, C.W.

    1960-09-01

    A gas lubricated bearing for a rotating shaft is described. The assembly comprises a stationary collar having an annular member resiliently supported thereon. The collar and annular member are provided with cooperating gas passages arranged for admission of pressurized gas which supports and lubricates a bearing block fixed to the rotatable shaft. The resilient means for the annular member support the latter against movement away from the bearing block when the assembly is in operation.

  20. Grizzly bear

    Science.gov (United States)

    Schwartz, C.C.; Miller, S.D.; Haroldson, M.A.; Feldhamer, G.; Thompson, B.; Chapman, J.

    2003-01-01

    The grizzly bear inspires fear, awe, and respect in humans to a degree unmatched by any other North American wild mammal. Like other bear species, it can inflict serious injury and death on humans and sometimes does. Unlike the polar bear (Ursus maritimus) of the sparsely inhabited northern arctic, however, grizzly bears still live in areas visited by crowds of people, where presence of the grizzly remains physically real and emotionally dominant. A hike in the wilderness that includes grizzly bears is different from a stroll in a forest from which grizzly bears have been purged; nighttime conversations around the campfire and dreams in the tent reflect the presence of the great bear. Contributing to the aura of the grizzly bear is the mixture of myth and reality about its ferocity. unpredictable disposition, large size, strength, huge canines, long claws, keen senses, swiftness, and playfulness. They share characteristics with humans such as generalist life history strategies. extended periods of maternal care, and omnivorous diets. These factors capture the human imagination in ways distinct from other North American mammals. Precontact Native American legends reflected the same fascination with the grizzly bear as modern stories and legends (Rockwell 1991).

  1. Les trotskystes grecs pendant la seconde guerre Mondiale

    Directory of Open Access Journals (Sweden)

    Alexis Hen

    2011-11-01

    Full Text Available Comment les deux courants du trotskysme grec, pourchassés dès les années 30, ont-ils réagi face à l'occupation de leur pays et à la résistance d'obédience communiste ?Les trotskystes en Grèce étaient divisés, malgré des discussions d’unification dans les camps de Metaxas. Ils refusèrent de soutenir la Grèce contre l’intervention italo-allemande en 1940-1941 et s’opposèrent aux illusions dans les démocraties alliées. Fin 1942 ils reprirent une activité clandestine, refusant de se joindre à la Résistance mais aussi de choisir un côté militaire dans les affrontements avec l’occupant et ses supplétifs. En octobre 1944, les trotskystes s'agitèrent contre les Britanniques pendant que l’EAM les laissait entrer dans Athènes. Le KKE exécuta des dizaines de trotskystes. Ceux-ci restèrent neutres dans la guerre civile de décembre 1944. Leur sectarisme contribua à les stériliser lorsque, après les accords de Varkiza en février 1945, la direction du KKE était vulnérable aux accusations qu’elle avait conduit la révolution à la défaite.Trotskyists in Greece were divided, despite unification discussions in Metaxas’ concentration camps. They refused to support Greece against the 1940-41 Italo-German intervention and opposed illusions in Allied democracies. At the end of 1942 they resumed underground activity, refusing to join the Resistance but also to take a military side in the fighting against the occupiers and their local proxy forces. In October 1944 the Trotskyists agitated against the British while the EAM let them into Athens. The KKE executed dozens of Trotskyists. The Trotskyists remained neutral in the December 1944 civil war. Their sectarianism contributed to sterilize them when, after the February 1945 Varkiza Agreement, the KKE leadership was vulnerable to accusations of having led the revolution to defeat.

  2. Azobisisobutyronitrile initiated aerobic oxidative transformation of amines: coupling of primary amines and cyanation of tertiary amines.

    Science.gov (United States)

    Liu, Lianghui; Wang, Zikuan; Fu, Xuefeng; Yan, Chun-Hua

    2012-11-16

    In the presence of a catalytic amount of radical initiator AIBN, primary amines are oxidatively coupled to imines and tertiary amines are cyanated to α-aminonitriles. These "metal-free" aerobic oxidative coupling reactions may find applications in a wide range of "green" oxidation chemistry.

  3. Thermal and Dielectric Behavior Studies of Poly(Arylene Ether Sulfones with Sulfonated and Phosphonated Pendants

    Directory of Open Access Journals (Sweden)

    Shimoga D. Ganesh

    2016-01-01

    Full Text Available The present paper discusses the aspects of the synthesizing valeric acid based poly(ether sulfones with active carboxylic acid pendants (VALPSU from solution polymerization technique via nucleophilic displacement polycondensation reaction among 4,4′-dichlorodiphenyl sulfone (DCDPS and 4,4′-bis(4-hydroxyphenyl valeric acid (BHPA. The conditions necessary to synthesize and purify the polymer were investigated in some detail. The synthesized poly(ether sulfones comprise sulfone and ether linkages in addition to reactive carboxylic acid functionality; these active carboxylic acid functional groups were exploited to hold the phenyl sulphonic acid and phenyl phosphonic acid pendants. The phenyl sulphonic acid pendants in VALPSU were easily constructed by altering active carboxylic acid moieties by sulfanilic acid using N,N′-dicyclohexylcarbodiimide (DCC mediated mild synthetic route, whereas the latter one was built in two steps. Initially, polyphosphoric acid condensation with VALPSU by 4-bromoaniline and next straightforward palladium catalyzed synthetic route, in both of which acidic pendants are clenched by polymer backbone via amide linkage. Without impairing the primary polymeric backbone modified polymers were prepared by varying the stoichiometric ratios of respective combinations. All the polymers were physicochemically characterized and pressed into tablets; electrical contacts were established to study the dielectric properties. Finally, the influence of the acidic pendants on the dielectric properties was examined.

  4. The economics of amine usage

    International Nuclear Information System (INIS)

    Fountain, M.J.

    1994-01-01

    Research carried out over the past decade in the USA (funded by EPRI) and by the CEGB/Nuclear Electric in the UK has identified several thermally stable, low-toxicity 'advanced' amines with good high-temperature basicity and low steam-water distribution ratio. As a direct result of this work several US PWR stations are now evaluating monoethanolamine (ETA) and Nuclear Electric's Wylfa Power Station (magnox) now doses 5 aminopentanol (5AP) instead of AMP, which had successfully combated erosion-corrosion for the past nine years. It has recently been stated that the use of 5AP ''...could save Nuclear Electric up to 1.5M pounds per year''. To provide US power station chemists with a tool for tailoring amine dosage to their own plant requirements EPRI has developed a computer model, Aminmod, which can, with user-defined circuit parameters and amine feed concentrations, calculate amine concentrations and pH(t) values at various points around the circuit. To complement this model a user-friendly spreadsheet program is being developed which will work in conjunction with Aminmod, via active links, to calculate the total operating cost associated with the selected amine dosing regime and compare alternative scenarios. This paper discusses the relationship between the technical and economic aspects of choosing an amine dosing regime and draws on combined Aminmod/spreadsheet results to illustrate how differences in amine properties can influence the optimum economic solution for a typical PWR. (author). 3 figs., 2 tabs., 5 refs

  5. Pendant unit effect on electron tunneling in U-shaped molecules

    International Nuclear Information System (INIS)

    Liu Min; Chakrabarti, Subhasis; Waldeck, David H.; Oliver, Anna M.; Paddon-Row, Michael N.

    2006-01-01

    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

  6. Oxidation of amines by flavoproteins.

    Science.gov (United States)

    Fitzpatrick, Paul F

    2010-01-01

    Many flavoproteins catalyze the oxidation of primary and secondary amines, with the transfer of a hydride equivalent from a carbon-nitrogen bond to the flavin cofactor. Most of these amine oxidases can be classified into two structural families, the D-amino acid oxidase/sarcosine oxidase family and the monoamine oxidase family. This review discusses the present understanding of the mechanisms of amine and amino acid oxidation by flavoproteins, focusing on these two structural families. Copyright 2009 Elsevier Inc. All rights reserved.

  7. PREPARATION AND PROPERTY OF POLYMERIC PENDANT Ru(bpy)32+ COMPLEXES

    Institute of Scientific and Technical Information of China (English)

    HOU Xiaohuai; Masao Kaneko; Akira Yamada

    1984-01-01

    Polymeric pendant Ru(bpy)32+ complexes were prepared from homopolymer and copolymers of 4-methyl-4'-vinyl-2,2'-bipyridine (Vbpy). Vbpy was prepared from 4-methylpyridine. The comonomers were styrene (St), acrylic acid (AA), N-vinylpyrrolidone (Pyr), 4-vinylpyridine (Vpy), methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), acrylonitrile (AN) and N-ethyl-4-vinylpyridium bromide (EQ-Vpy). The fraction of the pendant Ru(bpy)32+ repeating unit in the polymeric complex was 0.022 to 0.052. Absorption maximum, molar extinction coefficient, emission maximum and relative emission intensity of the polymeric complexes were studied.

  8. Ordering non-bipartite unicyclic graphs with pendant vertices by the least Q-eigenvalue

    Directory of Open Access Journals (Sweden)

    Shu-Guang Guo

    2016-05-01

    Full Text Available Abstract A unicyclic graph is a connected graph whose number of edges is equal to the number of vertices. Fan et al. (Discrete Math. 313:903-909, 2013 and Liu et al. (Electron. J. Linear Algebra 26:333-344, 2013 determined, independently, the unique unicyclic graph whose least Q-eigenvalue attains the minimum among all non-bipartite unicyclic graphs of order n with k pendant vertices. In this paper, we extend their results and determine the first three non-bipartite unicyclic graphs of order n with k pendant vertices ordering by least Q-eigenvalue.

  9. Chemoselective organocatalytic aerobic oxidation of primary amines to secondary imines.

    Science.gov (United States)

    Wendlandt, Alison E; Stahl, Shannon S

    2012-06-01

    Biomimetic aerobic oxidation of primary benzylic amines has been achieved by using a quinone catalyst. Excellent selectivity is observed for primary, unbranched benzylic amines relative to secondary/tertiary amines, branched benzylic amines, and aliphatic amines. The exquisite selectivity for benzylic amines enables oxidative self-sorting within dynamic mixtures of amines and imines to afford high yields of cross-coupled imine products.

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

    Energy Technology Data Exchange (ETDEWEB)

    Li Wei, E-mail: liwei-b09@mails.gucas.ac.c [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049 (China); Department of Physics, Beihang University, Beijing 100191 (China); Gong Shoushu [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049 (China); Chen Ziyu [Department of Physics, Beihang University, Beijing 100191 (China); Zhao Yang [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049 (China); Su Gang, E-mail: gsu@gucas.ac.c [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049 (China)

    2010-05-31

    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.

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

    International Nuclear Information System (INIS)

    Li Wei; Gong Shoushu; Chen Ziyu; Zhao Yang; Su Gang

    2010-01-01

    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.

  12. Comparison of the lateral retention forces on sessile and pendant water drops on a solid surface

    Science.gov (United States)

    de la Madrid, Rafael; Whitehead, Taylor; Irwin, George M.

    2015-06-01

    We present a simple experiment that demonstrates how a water drop hanging from a Plexiglas surface (pendant drop) experiences a lateral retention force that is comparable to, and in some cases larger than, the lateral retention force on a drop resting on top of the surface (sessile drop). The experiment also affords a simple demonstration of the Coriolis effect in two dimensions.

  13. Phosphoric acid doped polysulfone membranes with aminopyridine pendant groups and imidazole cross-links

    DEFF Research Database (Denmark)

    Hink, Steffen; Elsøe, Katrine; Cleemann, Lars Nilausen

    2015-01-01

    Udel polysulfone based membranes with 4-aminopyridine pendant groups and cross-linking imidazole units are synthesized in a simple two step reaction. The ratio of 4-aminopyridine and imidazole is varied and the materials are extensively characterized. The average phosphoric acid uptake (in 85 wt%...

  14. Sulfonated copolyimide membranes derived from a novel diamine monomer with pendant benzimidazole groups for fuel cells

    DEFF Research Database (Denmark)

    Li, Wei; Guo, Xiaoxia; Aili, David

    2015-01-01

    . A series of sulfonated copolyimides (SPI) are prepared via random copolymerizatio of 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) with a new diamine monomer with pendant benzimidazole groups, 2,2'-bis(4-(1H-benzo[d]imidazol-2-yl)phenoxy)benzidine (BIPOB), and a sulfonated diamine monomer 4,4'-bis...

  15. Organocatalytic asymmetric allylic amination of Morita–Baylis–Hillman carbonates of isatins

    Directory of Open Access Journals (Sweden)

    Hang Zhang

    2012-08-01

    Full Text Available The investigation of a Lewis base catalyzed asymmetric allylic amination of Morita–Baylis–Hillman carbonates derived from isatins afforded an electrophilic pathway to access multifunctional oxindoles bearing a C3-quaternary stereocenter, provided with good to excellent enantioselectivity (up to 94% ee and in high yields (up to 97%.

  16. Charge-delocalized κ2 C, N-NHC-amine complexes of rhodium, iridium, and ruthenium

    NARCIS (Netherlands)

    Jansen, Eveline; Lutz, Martin; Bruin, Bas De; Elsevier, Cornelis J.

    2014-01-01

    The development of a novel set of complexes bearing an NHC-amine ligand (CNHC-NH2) is described. M(cod) complexes (M = Ir, Rh) and a Ru complex have been synthesized in which three different coordination modes of the ligand were established: monodentate, neutral bidentate, and anionic bidentate. The

  17. Amine Swingbed Payload Project Management

    Science.gov (United States)

    Walsch, Mary; Curley, Su

    2013-01-01

    The International Space Station (ISS) has been designed as a laboratory for demonstrating technologies in a microgravity environment, benefitting exploration programs by reducing the overall risk of implementing such technologies in new spacecraft. At the beginning of fiscal year 2010, the ISS program manager requested that the amine-based, pressure-swing carbon dioxide and humidity absorption technology (designed by Hamilton Sundstrand, baselined for the Orion Multi-Purpose Crew Vehicle, and tested at the Johnson Space Center in relevant environments, including with humans, since 2005) be developed into a payload for ISS Utilization. In addition to evaluating the amine technology in a flight environment before the first launch of the Orion vehicle, the ISS program wanted to determine the capability of the amine technology to remove carbon dioxide from the ISS cabin environment at the metabolic rate of the full 6 ]person crew. Because the amine technology vents the absorbed carbon dioxide and water vapor to space vacuum (open loop), additional hardware needed to be developed to minimize the amount of air and water resources lost overboard. Additionally, the payload system would be launched on two separate Space Shuttle flights, with the heart of the payload-the swingbed unit itself-launching a full year before the remainder of the payload. This paper discusses the project management and challenges of developing the amine swingbed payload in order to accomplish the technology objectives of both the open -loop Orion application as well as the closed-loop ISS application.

  18. Hydrodynamic bearings

    CERN Document Server

    Bonneau, Dominique; Souchet, Dominique

    2014-01-01

    This Series provides the necessary elements to the development and validation of numerical prediction models for hydrodynamic bearings. This book describes the rheological models and the equations of lubrication. It also presents the numerical approaches used to solve the above equations by finite differences, finite volumes and finite elements methods.

  19. Bacterial degradation of monocyclic aromatic amines

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-08-01

    Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

  20. Sodium Perborate Oxidation of an Aromatic Amine

    Science.gov (United States)

    Juestis, Laurence

    1977-01-01

    Describes an experiment involving the oxidation of aromatic primary amines to the corresponding azo compound; suggests procedures for studying factors that influence the yield of such a reaction, including the choice of solvent and the oxidant-amine ratio. (MLH)

  1. Deposition of stable amine coating onto polycaprolactone nanofibers by low pressure cyclopropylamine plasma polymerization

    International Nuclear Information System (INIS)

    Manakhov, Anton; Nečas, David; Čechal, Jan; Pavliňák, David; Eliáš, Marek

    2015-01-01

    Amine-rich films are of high interest for the bio-applications including drug delivery and tissue engineering thanks to their high reactivity allowing the formation of the covalent linkages between biomolecules and a surface. However, the bio-applications of amine-rich films require their good stability in water which is often achieved at large expenses of the amine concentration. Recently, non-toxic cyclopropylamine (CPA) has been applied for the plasma polymerization of films bearing high NH x environment combined with the moderate thickness loss (20%) after water immersion for 48 h. In this work, the amine-rich film with the NH x concentration over 7 at.% was deposited on Si substrates and polycaprolactone nanofiber meshes by using CPA plasma polymerization (pulsed mode) in a vertically oriented stainless steel reactor. The substrates were placed at the radio frequency electrode and the ion bombardment caused by direct-current self-bias was suppressed by using high pressure of 50 Pa. Analysis of samples by scanning electron microscopy did not reveal any cracks in the deposited layer formed during a sample immersion in water. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed a slight oxidation of amine groups in water but the film still contained 5 at.% of NH x (according to the N1s XPS fitting) after the immersion. The rapid oxidation of amine groups was observed during the aging experiment carried out in air at room temperature because FTIR revealed an increase of amide peaks that increased progressively with aging time. However, this oxidation was significantly reduced if the plasma polymer was stored at − 20 °C. Since the films exhibit high amine concentration and very good water stability they have great potential for applications as biocompatible functional coatings. - Highlights: • Cyclopropylamine plasma polymers deposited on polycaprolactone nanofibers • Amine-rich films with high water stability

  2. Bearing structures

    International Nuclear Information System (INIS)

    Lee, A.S.; Preece, G.E.

    1988-01-01

    A hydrostatic bearing for the lower end of the vertical shaft of a sodium pump comprises a support shell encircling the shaft and a bush located between the shell and shaft. Liquid sodium is fed from the pump outlet to the bush/shaft and bush/shell interfaces to provide hydrostatic support. The bush outer surface and the shell inner surface are of complementary part-spherical shape and the bush floats relative to the shaft so that the bush can align itself with the shaft axis. Monitoring of the relative rotational speed of the bush with respect to the shaft (such rotation being induced by the viscous drag forces present) is also performed for the purposes of detecting abnormal operation of the bearing or partial seizure, at least one magnet is rotatable with the bush, and a magnetic sensor provides an output having a frequency related to the speed of the bush. (author)

  3. Tris[2-(2H-indazol-2-ylethyl]amine

    Directory of Open Access Journals (Sweden)

    Saúl Ovalle

    2012-06-01

    Full Text Available The title tertiary amine, C27H27N7, a potential tripodal ligand for coordination chemistry, crystallizes with the central N atom located on a threefold axis of a trigonal cell. The gauche conformation of the N(amime—CH2—CH2—N(indazole chain [torsion angle = −64.2 (2°] places the pendant 2H-indazole heterocycles surrounding the symmetry axis, affording a claw-like shaped molecule. Two symmetry-related indazole planes in the molecule make an acute angle of 60.39 (4°. The lone pair of the tertiary N atom is located inside the cavity, and should thus be inactive (as a ligand. In the crystal, neither significant π–π nor C—H...π interactions between molecules are found.

  4. Journal Bearings

    Directory of Open Access Journals (Sweden)

    Renato Brancati

    1999-01-01

    determined after acquiring and analysing the orbits described by the journal axis for assigned unbalance values in different operating conditions. Analysis of the results shows some particular operating features that were not entirely predicted by the theoretical model and which may give rise to malfunctions in the rotor-tilting pad bearings system. The tests were carried out in the rotor dynamics laboratory of the Dipartimento di Ingegneria Meccanica per l'Energetica at the University of Naples.

  5. Camshaft bearing arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Aoi, K.; Ozawa, T.

    1986-06-10

    A bearing arrangement is described for the camshaft of an internal combustion engine or the like which camshaft is formed along its length in axial order with a first bearing surface, a first cam lobe, a second bearing surface, a second cam lobe, a third bearing surface, a third cam lobe and a fourth bearing surface, the improvement comprising first bearing means extending around substantially the full circumference of the first bearing surface and journaling the first bearing surface, second bearing means extending around substantially less than the circumference of the second bearing surface and journaling the second bearing surface, third bearing means extending around substantially less than the circumference of the third bearing surface and journaling the third bearing surface, and fourth bearing means extending around substantially the full circumference of the fourth bearing surface and journaling the first bearing surface.

  6. Sensing system for detection and control of deposition on pendant tubes in recovery and power boilers

    Science.gov (United States)

    Kychakoff, George [Maple Valley, WA; Afromowitz, Martin A [Mercer Island, WA; Hogle, Richard E [Olympia, WA

    2008-10-14

    A system for detection and control of deposition on pendant tubes in recovery and power boilers includes one or more deposit monitoring sensors operating in infrared regions of about 4 or 8.7 microns and directly producing images of the interior of the boiler, or producing feeding signals to a data processing system for information to enable a distributed control system by which the boilers are operated to operate said boilers more efficiently. The data processing system includes an image pre-processing circuit in which a 2-D image formed by the video data input is captured, and includes a low pass filter for performing noise filtering of said video input. It also includes an image compensation system for array compensation to correct for pixel variation and dead cells, etc., and for correcting geometric distortion. An image segmentation module receives a cleaned image from the image pre-processing circuit for separating the image of the recovery boiler interior into background, pendant tubes, and deposition. It also accomplishes thresholding/clustering on gray scale/texture and makes morphological transforms to smooth regions, and identifies regions by connected components. An image-understanding unit receives a segmented image sent from the image segmentation module and matches derived regions to a 3-D model of said boiler. It derives a 3-D structure the deposition on pendant tubes in the boiler and provides the information about deposits to the plant distributed control system for more efficient operation of the plant pendant tube cleaning and operating systems.

  7. Highly efficient and diastereoselective gold(I)-catalyzed synthesis of tertiary amines from secondary amines and alkynes: substrate scope and mechanistic insights.

    Science.gov (United States)

    Liu, Xin-Yuan; Guo, Zhen; Dong, Sijia S; Li, Xiao-Hua; Che, Chi-Ming

    2011-11-11

    An efficient method for the synthesis of tertiary amines through a gold(I)-catalyzed tandem reaction of alkynes with secondary amines has been developed. In the presence of ethyl Hantzsch ester and [{(tBu)(2)(o-biphenyl)P}AuCl]/AgBF(4) (2 mol %), a variety of secondary amines bearing electron-deficient and electron-rich substituents and a wide range of alkynes, including terminal and internal aryl alkynes, aliphatic alkynes, and electron-deficient alkynes, underwent a tandem reaction to afford the corresponding tertiary amines in up to 99 % yield. For indolines bearing a preexisting chiral center, their reactions with alkynes in the presence of ethyl Hantzsch ester catalyzed by [{(tBu)(2)(o-biphenyl)P}AuCl]/AgBF(4) (2 mol %) afforded tertiary amines in excellent yields and with good to excellent diastereoselectivity. All of these organic transformations can be conducted as a one-pot reaction from simple and readily available starting materials without the need of isolation of air/moisture-sensitive enamine intermediates, and under mild reaction conditions (mostly room temperature and mild reducing agents). Mechanistic studies by NMR spectroscopy, ESI-MS, isotope labeling studies, and DFT calculations on this gold(I)-catalyzed tandem reaction reveal that the first step involving a monomeric cationic gold(I)-alkyne intermediate is more likely than a gold(I)-amine intermediate, a three-coordinate gold(I) intermediate, or a dinuclear gold(I)-alkyne intermediate. These studies also support the proposed reaction pathway, which involves a gold(I)-coordinated enamine complex as a key intermediate for the subsequent transfer hydrogenation with a hydride source, and reveal the intrinsic stereospecific nature of these transformations observed in the experiments. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Synthesis of Ethylene or Propylene/1,3-Butadiene Copolymers Possessing Pendant Vinyl Groups with Virtually No Internal Olefins

    OpenAIRE

    Kenji Michiue; Makoto Mitani; Terunori Fujita

    2015-01-01

    In general, ethylene/1,3-butadiene copolymerizations provides copolymers possessing both pendant vinyls and vinylenes as olefinic moieties. We, at MCI, studied the substituent effects of C2-symmetric zirconocene complexes, rac-[Me2Si(Indenyl’)2]ZrCl2 (Indenyl’ = generic substituted indenyl), after activation on the ratio of the pendant vinyls and vinylenes of the resultant copolymers. Complexes examined in this study were rac-dimethylsilylbis (1-indenyl)zirconium dichloride (1), rac-dimethyls...

  9. Biogenic Amines in Insect Antennae

    Directory of Open Access Journals (Sweden)

    Marianna I. Zhukovskaya

    2017-06-01

    Full Text Available Insect antenna is a multisensory organ, each modality of which can be modulated by biogenic amines. Octopamine (OA and its metabolic precursor tyramine (TA affect activity of antennal olfactory receptor neurons. There is some evidence that dopamine (DA modulates gustatory neurons. Serotonin can serve as a neurotransmitter in some afferent mechanosensory neurons and both as a neurotransmitter and neurohormone in efferent fibers targeted at the antennal vessel and mechanosensory organs. As a neurohormone, serotonin affects the generation of the transepithelial potential by sensillar accessory cells. Other possible targets of biogenic amines in insect antennae are hygro- and thermosensory neurons and epithelial cells. We suggest that the insect antenna is partially autonomous in the sense that biologically active substances entering its hemolymph may exert their effects and be cleared from this compartment without affecting other body parts.

  10. Synthesis and Preliminary Properties of Novel Poly(aryl ethers Containing β-Naphthalene Pendant Group

    Directory of Open Access Journals (Sweden)

    L. Wang

    2014-01-01

    Full Text Available Two novel poly(aryl ethers containing β-naphthalene pendant group were synthesized and the structures of these polymers were confirmed by 1HNMR spectroscopy. The polymers exhibited good thermal stabilities with high Tg of 256°C and 274°C, respectively. The polymers are soluble in common organic solvents, such as DMAc, DMSO, CH2Cl2, and CHCl3, and can be electrospun into microfiber (1–5 µm with lots of nanopores (<100 nm from CHCl3 solution. These fibers showed high hydrophobicity, and the contact angle of fibers is above 120°.

  11. Nano-anisotropic surface coating based on drug immobilized pendant polymer to suppress macrophage adhesion response.

    Science.gov (United States)

    Kaladhar, K; Renz, H; Sharma, C P

    2015-04-01

    Exploring drug molecules for material design, to harness concepts of nano-anisotropy and ligand-receptor interactions, are rather elusive. The aim of this study is to demonstrate the bottom-up design of a single-step and bio-interactive polymeric surface coating, based on drug based pendant polymer. This can be applied on to polystyrene (PS) substrates, to suppress macrophage adhesion and spreading. The drug molecule is used in this coating for two purposes. The first one is drug as a "pendant" group, to produce nano-anisotropic properties that can enable adhesion of the coatings to the substrate. The second purpose is to use the drug as a "ligand", to produce ligand-receptor interaction, between the bound ligand and receptors of albumin, to develop a self-albumin coat over the surface, by the preferential binding of albumin in biological environment, to reduce macrophage adhesion. Our in silico studies show that, diclofenac (DIC) is an ideal drug based "ligand" for albumin. This can also act as a "pendant" group with planar aryl groups. The combination of these two factors can help to harness, both nano-anisotropic properties and biological functions to the polymeric coating. Further, the drug, diclofenac (DIC) is immobilized to the polyvinyl alcohol (PVA), to develop the pendant polymer (PVA-DIC). The interaction of bound DIC with the albumin is a ligand-receptor based interaction, as per the studies by circular dichroism, differential scanning calorimetry, and SDS-PAGE. The non-polar π-π* interactions are regulating; the interactions between PVA bound DIC-DIC interactions, leading to "nano-anisotropic condensation" to form distinct "nano-anisotropic segments" inside the polymeric coating. This is evident from, the thermo-responsiveness and uniform size of nanoparticles, as well as regular roughness in the surface coating, with similar properties as that of nanoparticles. In addition, the hydrophobic DIC-polystyrene (PS) interactions, between the PVA

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

    Science.gov (United States)

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

    2011-01-01

    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.

  13. Iridium-Catalyzed Condensation of Primary Amines To Form Secondary Amines

    DEFF Research Database (Denmark)

    Lorentz-Petersen, Linda Luise Reeh; Jensen, Paw; Madsen, Robert

    2009-01-01

    Symmetric secondary amines are readily obtained by heating a neat primary amine with 0.5 mol% of bis(dichloro[eta(5)-pentamethylcyclopentadienyl]iridium). The products are isolated by direct distillation in good yields.......Symmetric secondary amines are readily obtained by heating a neat primary amine with 0.5 mol% of bis(dichloro[eta(5)-pentamethylcyclopentadienyl]iridium). The products are isolated by direct distillation in good yields....

  14. Charge-Delocalized κC-2,N-NHC-Amine Complexes of Rhodium, Iridium, and Ruthenium

    NARCIS (Netherlands)

    Jansen, E.; Lutz, M.; de Bruin, B.; Elsevier, C.J.

    2014-01-01

    The development of a novel set of complexes bearing an NHC-amine ligand (C-NHC-NH2) is described. M(cod) complexes (M = 1r, Rh) and a Ru complex have been synthesized in which three different coordination modes of the ligand were established: monodentate, neutral bidentate, and anionic bidentate.

  15. Novel bioreducible poly(amido amine)s for highly efficient gene delivery

    NARCIS (Netherlands)

    Lin, C.; Zhong, Zhiyuan; Lok, Martin C.; Jiang, Xulin; Hennink, Wim E.; Feijen, Jan; Engbersen, Johannes F.J.

    2007-01-01

    A series of novel bioreducible poly(amido amine)s containing multiple disulfide linkages (SS-PAAs) were synthesized and evaluated as nonviral gene vectors. These linear SS-PAAs could be easily obtained by Michael-type polyaddition of various primary amines to the disulfide-containing cystamine

  16. Fluorinated poly(ether sulfone) ionomers with disulfonated naphthyl pendants for proton exchange membrane applications

    Science.gov (United States)

    Hu, Zhaoxia; Lu, Yao; Zhang, Xulve; Yan, Xiaobo; Li, Na; Chen, Shouwen

    2018-06-01

    Proton exchange membranes based on fluorinated poly(ether sulfone)s with disulfonated naphthyl pendants (sSPFES) have been successfully prepared by post functionalization through polymeric SNAr reaction. Copolymer structure was confirmed by H-nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy, the physico-chemical properties of the sSPFES membranes were evaluated by thermogravimetric analysis, gel permeation chromatography, electro-chemical impedance spectroscopy, atomic force microscopy, Fenton, water-swelling and fuel cell test. The pendant grafting degree was controlled by varying the feeding amount of the disulfonaphthols, resulting in the ion exchange capacity about 1.28-1.73 mmol/g. The obtained sSPFES membranes were thermal stable, mechanical ductile, and exhibited dimensional change less than 17%, water uptake below 70%, and proton conductivity as high as 0.17-0.28 S/cm at 90°C in water. In a single H2/O2 fuel cell test at 80°C, the sSPFES-B-3.2 membrane (1.61 mmol/g) showed the maximum power output of 593-658 mW/cm2 at 60%-80% relative humidity, indicating their rather promising potential for fuel cell applications.

  17. Proton Transfer in Perfluorosulfonic Acid Fuel Cell Membranes with Differing Pendant Chains and Equivalent Weights.

    Science.gov (United States)

    Thomaz, Joseph E; Lawler, Christian M; Fayer, Michael D

    2017-05-04

    Proton transfer in the nanoscopic water channels of polyelectrolyte fuel cell membranes was studied using a photoacid, 8-hydroxypyrene-1,3,6-trisulfonic acid sodium salt (HPTS), in the channels. The local environment of the probe was determined using 8-methoxypyrene-1,3,6-trisulfonic acid sodium salt (MPTS), which is not a photoacid. Three fully hydrated membranes, Nafion (DuPont) and two 3M membranes, were studied to determine the impact of different pendant chains and equivalent weights on proton transfer. Fluorescence anisotropy and excited state population decay data that characterize the local environment of the fluorescent probes and proton transfer dynamics were measured. The MPTS lifetime and anisotropy results show that most of the fluorescent probes have a bulk-like water environment with a relatively small fraction interacting with the channel wall. Measurements of the HPTS protonated and deprotonated fluorescent bands' population decays provided information on the proton transport dynamics. The decay of the protonated band from ∼0.5 ns to tens of nanoseconds is in part determined by dissociation and recombination with the HPTS, providing information on the ability of protons to move in the channels. The dissociation and recombination is manifested as a power law component in the protonated band fluorescence decay. The results show that equivalent weight differences between two 3M membranes resulted in a small difference in proton transfer. However, differences in pendant chain structure did significantly influence the proton transfer ability, with the 3M membranes displaying more facile transfer than Nafion.

  18. Intracellular drug delivery nanocarriers of glutathione-responsive degradable block copolymers having pendant disulfide linkages.

    Science.gov (United States)

    Khorsand, Behnoush; Lapointe, Gabriel; Brett, Christopher; Oh, Jung Kwon

    2013-06-10

    Self-assembled micelles of amphiphilic block copolymers (ABPs) with stimuli-responsive degradation (SRD) properties have a great promise as nanotherapeutics exhibiting enhanced release of encapsulated therapeutics into targeted cells. Here, thiol-responsive degradable micelles based on a new ABP consisting of a pendant disulfide-labeled methacrylate polymer block (PHMssEt) and a hydrophilic poly(ethylene oxide) (PEO) block were investigated as effective intracellular nanocarriers of anticancer drugs. In response to glutathione (GSH) as a cellular trigger, the cleavage of pendant disulfide linkages in hydrophobic PHMssEt blocks of micellar cores caused the destabilization of self-assembled micelles due to change in hydrophobic/hydrophilic balance. Such GSH-triggered micellar destabilization changed their size distribution with an appearance of large aggregates and led to enhanced release of encapsulated anticancer drugs. Cell culture results from flow cytometry and confocal laser scanning microscopy for cellular uptake as well as cell viability measurements for high anticancer efficacy suggest that new GSH-responsive degradable PEO-b-PHMssEt micelles offer versatility in multifunctional drug delivery applications.

  19. Monitoring protein phosphorylation by acrylamide pendant Phos-Tag™ in various plants

    Directory of Open Access Journals (Sweden)

    Slavka eBekesova

    2015-05-01

    Full Text Available The aim of the present study is to rationalize acrylamide pendant Phos-Tag™ in-gel discrimination of phosphorylated and non-phosphorylated plant protein species with standard immunoblot analysis, and optimize sample preparation, efficient electrophoretic separation and transfer. We tested variants of the method including extraction buffers suitable for preservation of phosphorylated protein species in crude extracts from plants and we addressed the importance of the cation (Mn2+ or Zn2+ used in the gel recipe for efficient transfer to PVDF membranes for further immunoblot analysis. We demonstrate the monitoring of Medicago sativa stress-induced mitogen activated protein kinase (SIMK in stress-treated wild type plants and transgenic SIMKK RNAi line. We further show the hyperosmotically-induced phosphorylation of the previously uncharacterized HvMPK4 of barley. The method is validated using inducible phosphorylation of barley and wheat α-tubulin and of Arabidopsis MPK6. Acrylamide pendant Phos-Tag™ offers a flexible tool for studying protein phosphorylation in crops and Arabidopsis circumventing radioactive labeling and the use of phosphorylation specific antibodies.

  20. Intolerance to dietary biogenic amines: A review

    NARCIS (Netherlands)

    Jansen, S.C.; Dusseldorp, M. van; Bottema, K.C.; Dubois, A.E.J.

    2003-01-01

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and

  1. Intolerance to dietary biogenic amines : a review

    NARCIS (Netherlands)

    Jansen, SC; van Dusseldorp, M; Bottema, KC; Dubois, AEJ

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allergen intoler*, and

  2. Method for the production of primary amines

    NARCIS (Netherlands)

    Baldenius, Kai-Uwe; Ditrich, Klaus; Breurer, Michael; Navickas, Vaidotas; Janssen, Dick; Crismaru, Ciprian; Bartsch, Sebastian

    2014-01-01

    The present invention relates to a novel enzymatically catalyzed method for the production of aliphatic primary amines, which method comprises the enzymatic oxidation of a primary aliphatic alcohol catalyzed by an alcohol dehydrogenase, amination of the resulting oxocompound catalyzed by a

  3. Sillica Gel-Amine from Geothermal Sludge

    Science.gov (United States)

    Muljani, S.; Pujiastuti, C.; Wicaksono, P.; Lutfianingrum, R.

    2018-01-01

    Silica Gel-Amine (SGA) has been made from geothermal sludge by grafting amine method. Sodium silicate solution is prepared by extracted geothermal sludge powder using sodium hidroxide solution then acidification in the range of pH 5 - 9 by using tartaric acid 1N. The grafting process uses 1 ml of ammonia solution and 10 ml of toluene at a rate of 0.1 ml min-1 accompanied by a reflux process. The amine grafting is done in two methods. The first method is grafting amine in silicate solution and the second method is grafting amine in washed gel. Product SGA was confirmed by FTIR, TGA-DTG and BET characterization. The results show that the pH affects the amount of amine that is grafted onto silica gel. Differences in grafting method affect the size of the pore and surface area. SGA product prepared by grafting washed gel at pH 8 have pore diameter of 12.06 nm, surface area of 173.44 m2g-1, and mass of decomposed amine compound 0.4 mg. In the presence of amine groups on the silica gel surface, these adsorbents may be able to selectively adsorb CO2 gas from natural gas.

  4. Amine Measurements in Boreal Forest Air

    Science.gov (United States)

    Hemmilä, Marja; Hellén, Heidi; Makkonen, Ulla; Hakola, Hannele

    2015-04-01

    Amines are reactive, volatile bases in the air with a general formula of RNH2, R2NH or R3N. Especially small amines can stabilize sulphuric acid clusters and hence affect nucleation. Amines react rapidly with hydroxyl radical (OH˙) thus affecting oxidative capacity of the atmosphere. The amine concentrations are higher in forest air than in urban air (Hellén et al., 2014), but the sources are not known. In order to get more information concerning amine sources, we conducted a measurement campaign in a boreal forest. At SMEAR II station at Hyytiälä, Southern Finland (61°510'N, 24°170'E, 180 m a.s.l.) The measurements cover seven months, from June to December 2014. For sampling and measuring we used MARGA (The instrument for Measuring AeRosols and Gases in Ambient air) which is an on-line ion chromatograph (IC) connected to a sampling system. The IC component of the MARGA system was coupled to an electrospray ionization quadrupole mass spectrometer (MS) to improve sensitivity of amine measurements. This new set-up enabled amine concentration measurements in ambient air both in aerosol and gas phases with a time resolution of only 1 hour. With MARGA-MS we analysed 7 different amines: monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), propylamine (PA) and butylamine (BA). In preliminary data-analysis we found out, that in June and July most of the measured amines were in gas phase, and particle phase amine concentrations were mostly under detection limits (<1.7 pptv). In June the gaseous amine concentrations were higher than in July. The measured concentrations of gaseous amines followed temperature variation, which could indicate that amines are produced and emitted from the environment or re-emitted from the surfaces as temperature rises after deposition during night-time. All measured amines had similar diurnal variation with maxima during afternoon and minima during night. Results from other months will also

  5. Extraction of sulphates by long chain amines

    International Nuclear Information System (INIS)

    Boirie, Ch.

    1959-05-01

    The extraction of sulphuric acid by long chain amines in organic solution has been studied with a view to determining the value of the stability constants of the amine sulphates and bi-sulphates formed. We have concentrated chiefly on uranium sulphate and thorium sulphate. The formulae of the complexes extractable with amines have been established, as well as the corresponding dissociation constants. We have observed that for uranium sulphate the formula of the complex depends only on the nature of the amine, whereas for thorium this formula varies with the amine structure. From the formulae determined and the value of the constants calculated, we have been able to establish the best conditions for uranium and thorium extraction and also for a separation of these two elements. Finally we propose an application of this study to the determination of uranium in ores, where the separation of uranium by this method is particularly easy and complete. (author) [fr

  6. Thermodynamics of mixtures containing amines

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)], E-mail: jagl@termo.uva.es; Mozo, Ismael; Garcia de la Fuente, Isaias; Cobos, Jose Carlos [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Riesco, Nicolas [Department of Chemical Engineering, Loughborough University, Loughborough, LE113TU Leicestershire (United Kingdom)

    2008-01-30

    Mixtures with dimethyl or trimethylpyridines and alkane, aromatic compound or 1-alkanol have been examined using different theories: DISQUAC, Flory, the concentration-concentration structure factor, S{sub CC}(0), or the Kirkwood-Buff formalism. DISQUAC represents fairly well the available experimental data, and improves theoretical calculations from Dortmund UNIFAC. Two important effects have been investigated: (i) the effect of increasing the number of methyl groups attached to the aromatic ring of the amine; (ii) the effect of modifying the position of the methyl groups in this ring. The molar excess enthalpy, H{sup E}, and the molar excess volume, V{sup E}, decrease in systems with alkane or methanol as follows: pyridine > 3-methylpyridine > 3,5-dimethylpyridine and pyridine > 2-methylpyridine > 2,4-dimethylpyridine > 2,4,6-trimethylpyridine, which has been attributed to a weakening of the amine-amine interactions in the same sequences. This is in agreement with the relative variation of the effective dipole moment, {mu}-bar, and of the differences between the boiling temperature of a pyridine base and that of the homomorphic alkane. For heptane solutions, the observed H{sup E} variation, H{sup E} (3,5-dimethylpyridine) > H{sup E} (2,4-dimethylpyridine) > H{sup E} (2,6-dimethylpyridine), is explained similarly. Calculations on the basis of the Flory model confirm that orientational effects become weaker in systems with alkane in the order: pyridine > methylpyridine > dimethylpyridine > trimethylpyridine. S{sub CC}(0) calculations show that steric effects increase with the number of CH{sub 3}- groups in the pyridine base, and that the steric effects exerted by methyl groups in positions 2 and 6 are higher than when they are placed in positions 3 and 5. The hydrogen bond energy in methanol mixtures is independent of the pyridine base, and it is estimated to be -35.2 kJ mol{sup -1}. Heterocoordination in these solutions is due in part to size effects. Their

  7. Passive magnetic bearing configurations

    Science.gov (United States)

    Post, Richard F [Walnut Creek, CA

    2011-01-25

    A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

  8. Synthesis and in vivo antimalarial activity of novel naphthoquine derivatives with linear/cyclic structured pendants.

    Science.gov (United States)

    Tang, Ling; Bei, Zhuchun; Song, Yabin; Xu, Likun; Wang, Hong; Zhang, Dongna; Dou, Yuanyuan; Lv, Kai; Wang, Hongquan

    2017-07-01

    Naphthoquine (NQ) was discovered by our institute as an antimalarial candidate in 1980s, and currently employed as an artemisinin-based combination therapy partner drug. Resistance to NQ was found in mouse model in laboratory, and might emerge in future as widely used. We herein report the design and synthesis of NQ derivatives by replacing t-butyl moiety with linear/cyclic structured pendants. All the target compounds 6a-l and intermediates 5a-h were tested for their in vivo antimalarial activity against Plasmodium berghei K173 strain in mice. Compounds 6a and 6j were found to have a comparable or slightly more potent activity (the 50% effective dose [ED 50 ], which is required to decrease parasitemia by 50%: 0.38-0.43 mg/kg) than NQ (ED 50 : 0.48 mg/kg). The newly designed compounds 6a and 6j might be promising antimalarial candidates for further research.

  9. Measurement of interfacial tension by use of pendant drop video techniques

    Science.gov (United States)

    Herd, Melvin D.; Thomas, Charles P.; Bala, Gregory A.; Lassahn, Gordon D.

    1993-09-01

    This report describes an instrument to measure the interfacial tension (IFT) of aqueous surfactant solutions and crude oil. The method involves injection of a drop of fluid (such as crude oil) into a second immiscible phase to determine the IFT between the two phases. The instrument is composed of an AT-class computer, optical cell, illumination, video camera and lens, video frame digitizer board, monitor, and software. The camera displays an image of the pendant drop on the monitor, which is then processed by the frame digitizer board and non-proprietary software to determine the IFT. Several binary and ternary phase systems were taken from the literature and used to measure the precision and accuracy of the instrument in determining IFT's. A copy of the software program is included in the report. A copy of the program on diskette can be obtained from the Energy Science and Technology Software Center, P.O. Box 1020, Oak Ridge, TN 37831-1020. The accuracy and precision of the technique and apparatus presented is very good for measurement of IFT's in the range from 72 to 10(exp -2) mN/m, which is adequate for many EOR applications. With modifications to the equipment and the numerical techniques, measurements of ultralow IFT's (less than 10(exp -3) mN/m) should be possible as well as measurements at reservoir temperature and pressure conditions. The instrument has been used at the Idaho National Engineering Laboratory to support the research program on microbial enhanced oil recovery. Measurements of IFT's for several bacterial supernatants and unfractionated acid precipitates of microbial cultures containing biosurfactants against medium to heavy crude oils are reported. These experiments demonstrate that the use of automated video imaging of pendant drops is a simple and fast method to reliably determine interfacial tension between two immiscible liquid phases, or between a gas and a liquid phase.

  10. The influence of pendant carboxylic acid loading on surfaces of statistical poly(4-hydroxystyrene)-co-styrene)s

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Hvilsted, Søren

    2008-01-01

    . In particular, aliphatic and aromatic pendant groups differ by 92°C in Tg• Contact angle measurements onspin coated films have shown a maximum effect of the functional groups in the advancing contact angle at a 75/100 copolymer loading. In addition to this, X-ray photoelectron spectroscopy shows the presence...

  11. Tunable, chemoselective amination via silver catalysis.

    Science.gov (United States)

    Rigoli, Jared W; Weatherly, Cale D; Alderson, Juliet M; Vo, Brian T; Schomaker, Jennifer M

    2013-11-20

    Organic N-containing compounds, including amines, are essential components of many biologically and pharmaceutically important molecules. One strategy for introducing nitrogen into substrates with multiple reactive bonds is to insert a monovalent N fragment (nitrene or nitrenoid) into a C-H bond or add it directly to a C═C bond. However, it has been challenging to develop well-defined catalysts capable of promoting predictable and chemoselective aminations solely through reagent control. Herein, we report remarkable chemoselective aminations that employ a single metal (Ag) and a single ligand (phenanthroline) to promote either aziridination or C-H insertion by manipulating the coordination geometry of the active catalysts.

  12. Biogenic amines and radiosensitivity of solitary cells

    International Nuclear Information System (INIS)

    Goncharenko, E.N.

    1978-01-01

    Different stability of cells to ionizing radiation is considered from a position of the ''elevated biochemical radioresistance background'' concept. Experimental evidence presented indicates an important role of endogenic amines (serotonin and histamine) possessing radioprotector properties in the cell radioresistance formation. The concept about their effect as being solely a result of circulatory hypoxia is critically discussed. The experimental results favor the existence of a ''cellular'' component, along with the ''hypoxic'' one, in the mechanism of action of biogenic amines. These compounds can affect the initial stages of peroxide oxidation of lipids, thereby favoring a less intensive oxidation induced by radiation. Biogenic amines can also exert influence on the cyclic nucleotide system

  13. Water-bearing explosive containing nitrogen-base salt

    Energy Technology Data Exchange (ETDEWEB)

    Dunglinson, C.; Lyerly, W.M.

    1968-10-21

    A water-bearing explosive composition consists of an oxidizing salt component, a fuel component, and water. A sensitizer is included having an oxygen balance more positive than -150%, and consisting of a salt of an inorganic oxidizing acid and of an acyclic nitrogen base having no more than 2 hydrogen atoms bonded to the basic nitrogen and up to 3 carbons per basic nitrogen, and/or of a phenyl amine. 41 claims.

  14. Deposition of stable amine coating onto polycaprolactone nanofibers by low pressure cyclopropylamine plasma polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Manakhov, Anton [Plasma Technologies, CEITEC — Central European Institute of Technology, Masaryk University, Kotlářská 2, Brno 61137 (Czech Republic); Nečas, David [Plasma Technologies, CEITEC — Central European Institute of Technology, Masaryk University, Kotlářská 2, Brno 61137 (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 2, Brno 61137 (Czech Republic); Čechal, Jan [CEITEC — Central European Institute of Technology, Brno University of Technology, Technická 3058/10, 616 00 Brno (Czech Republic); Pavliňák, David [Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 2, Brno 61137 (Czech Republic); Eliáš, Marek [Plasma Technologies, CEITEC — Central European Institute of Technology, Masaryk University, Kotlářská 2, Brno 61137 (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 2, Brno 61137 (Czech Republic); and others

    2015-04-30

    Amine-rich films are of high interest for the bio-applications including drug delivery and tissue engineering thanks to their high reactivity allowing the formation of the covalent linkages between biomolecules and a surface. However, the bio-applications of amine-rich films require their good stability in water which is often achieved at large expenses of the amine concentration. Recently, non-toxic cyclopropylamine (CPA) has been applied for the plasma polymerization of films bearing high NH{sub x} environment combined with the moderate thickness loss (20%) after water immersion for 48 h. In this work, the amine-rich film with the NH{sub x} concentration over 7 at.% was deposited on Si substrates and polycaprolactone nanofiber meshes by using CPA plasma polymerization (pulsed mode) in a vertically oriented stainless steel reactor. The substrates were placed at the radio frequency electrode and the ion bombardment caused by direct-current self-bias was suppressed by using high pressure of 50 Pa. Analysis of samples by scanning electron microscopy did not reveal any cracks in the deposited layer formed during a sample immersion in water. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed a slight oxidation of amine groups in water but the film still contained 5 at.% of NH{sub x} (according to the N1s XPS fitting) after the immersion. The rapid oxidation of amine groups was observed during the aging experiment carried out in air at room temperature because FTIR revealed an increase of amide peaks that increased progressively with aging time. However, this oxidation was significantly reduced if the plasma polymer was stored at − 20 °C. Since the films exhibit high amine concentration and very good water stability they have great potential for applications as biocompatible functional coatings. - Highlights: • Cyclopropylamine plasma polymers deposited on polycaprolactone nanofibers • Amine-rich films with high

  15. Anodic selective functionalization of cyclic amine derivatives

    OpenAIRE

    Onomura, Osamu

    2012-01-01

    Anodic reactions are desirable methods from the viewpoint of Green Chemistry, since no toxic oxidants are necessary for the oxidation of organic molecules. This review introduces usefulness of anodic oxidation and successive reaction for selective functionalization of cyclic amine derivatives.

  16. Transition metals in the amination of chloroarenes

    Energy Technology Data Exchange (ETDEWEB)

    Serdyuk, O V [Leibniz-Institut fuer Katalyse an der Universitaet Rostock (Germany); Abaev, Vladimir T [North-Ossetia State University, Vladikavkaz (Russian Federation)

    2009-11-30

    The review is devoted to the catalytic amination of chloroarenes and chlorohetarenes. Examples of the formation of the C-N bond in the presence of iron-, nickel- and copper-based catalytic systems are given.

  17. Selective N-alkylation of amines using nitriles under hydrogenation conditions: facile synthesis of secondary and tertiary amines.

    Science.gov (United States)

    Ikawa, Takashi; Fujita, Yuki; Mizusaki, Tomoteru; Betsuin, Sae; Takamatsu, Haruki; Maegawa, Tomohiro; Monguchi, Yasunari; Sajiki, Hironao

    2012-01-14

    Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH(4)OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.

  18. General Dialdehyde Click Chemistry for Amine Bioconjugation.

    Science.gov (United States)

    Elahipanah, Sina; O'Brien, Paul J; Rogozhnikov, Dmitry; Yousaf, Muhammad N

    2017-05-17

    The development of methods for conjugating a range of molecules to primary amine functional groups has revolutionized the fields of chemistry, biology, and material science. The primary amine is a key functional group and one of the most important nucleophiles and bases used in all of synthetic chemistry. Therefore, tremendous interest in the synthesis of molecules containing primary amines and strategies to devise chemical reactions to react with primary amines has been at the core of chemical research. In particular, primary amines are a ubiquitous functional group found in biological systems as free amino acids, as key side chain lysines in proteins, and in signaling molecules and metabolites and are also present in many natural product classes. Due to its abundance, the primary amine is the most convenient functional group handle in molecules for ligation to other molecules for a broad range of applications that impact all scientific fields. Because of the primary amine's central importance in synthetic chemistry, acid-base chemistry, redox chemistry, and biology, many methods have been developed to efficiently react with primary amines, including activated carboxylic acids, isothiocyanates, Michael addition type systems, and reaction with ketones or aldehydes followed by in situ reductive amination. Herein, we introduce a new traceless, high-yield, fast click-chemistry method based on the rapid and efficient trapping of amine groups via a functionalized dialdehyde group. The click reaction occurs in mild conditions in organic solvents or aqueous media and proceeds in high yield, and the starting dialdehyde reagent and resulting dialdehyde click conjugates are stable. Moreover, no catalyst or dialdehyde-activating group is required, and the only byproduct is water. The initial dialdehyde and the resulting conjugate are both straightforward to characterize, and the reaction proceeds with high atom economy. To demonstrate the broad scope of this new click

  19. Synthesis and bioelectrochemical behavior of aromatic amines.

    Science.gov (United States)

    Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Bolte, Michael; McKee, Vickie

    2017-12-01

    Four aromatic amines 1-amino-4-phenoxybenzene (A 1 ), 4-(4-aminophenyloxy) biphenyl (A 2 ), 1-(4-aminophenoxy) naphthalene (A 3 ) and 2-(4-aminophenoxy) naphthalene (A 4 ) were synthesized and characterized by elemental, spectroscopic (FTIR, NMR), mass spectrometric and single crystal X-ray diffraction methods. The compounds crystallized in monoclinic crystal system with space group P2 1 . Intermolecular hydrogen bonds were observed between the amine group and amine/ether acceptors of neighboring molecules. Electrochemical investigations were done using cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV). CV studies showed that oxidation of aromatic amines takes place at about 0.9 V (vs. Ag/AgCl) and the electron transfer (ET) process has irreversible nature. After first scan reactive intermediate were generated electrochemically and some other cathodic and anodic peaks also appeared in the succeeding scans. DPV study revealed that ET process is accompanied by one electron. DNA binding study of aromatic amines was performed by CV and UV-visible spectroscopy. These investigations revealed groove binding mode of interaction of aromatic amines with DNA. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Enhancing amine terminals in an amine-deprived collagen matrix.

    LENUS (Irish Health Repository)

    Tiong, William H C

    2008-10-21

    Collagen, though widely used as a core biomaterial in many clinical applications, is often limited by its rapid degradability which prevents full exploitation of its potential in vivo. Polyamidoamine (PAMAM) dendrimer, a highly branched macromolecule, possesses versatile multiterminal amine surface groups that enable them to be tethered to collagen molecules and enhance their potential. In this study, we hypothesized that incorporation of PAMAM dendrimer in a collagen matrix through cross-linking will result in a durable, cross-linked collagen biomaterial with free -NH 2 groups available for further multi-biomolecular tethering. The aim of this study was to assess the physicochemical properties of a G1 PAMAM cross-linked collagen matrix and its cellular sustainability in vitro. Different amounts of G1 PAMAM dendrimer (5 or 10 mg) were integrated into bovine-derived collagen matrices through a cross-linking process, mediated by 5 or 25 mM 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) in 5 mM N-hydroxysuccinimide (NHS) and 50 mM 2-morpholinoethane sulfonic acid buffer at pH 5.5. The physicochemical properties of resultant matrices were investigated with scanning electron microscopy (SEM), collagenase degradation assay, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectra, and ninhydrin assay. Cellular sustainability of the matrices was assessed with Alamar Blue assay and SEM. There was no significant difference in cellular behavior between the treated and nontreated groups. However, the benefit of incorporating PAMAM in the cross-linking reaction was limited when higher concentrations of either agent were used. These results confirm the hypothesis that PAMAM dendrimer can be incorporated in the collagen cross-linking process in order to modulate the properties of the resulting cross-linked collagen biomaterial with free -NH 2 groups available for multi-biomolecular tethering.

  1. Teddy Bear Stories

    DEFF Research Database (Denmark)

    van Leeuwen, Theo; Caldas-Coulthardt, Carmen

    2014-01-01

    This paper presents a semiotic analysis of a key cultural artefact, the teddy bear. After introducing the iconography of the teddy bear, it analyses different kinds of stories to show how teddy bears are endowed with meaning in everyday life: stories from children's books, reminiscenses by adults...... bears have traditionally centred on interpersonal relations within the nuclear family, but have recently been institutionalized and commercialized....

  2. No 129-L'exercice physique pendant la grossesse et le postpartum.

    Science.gov (United States)

    Davies, Gregory A L; Wolfe, Larry A; Mottola, Michelle F; MacKinnon, Catherine

    2018-02-01

    Énoncer une directive canadienne visant à informer les fournisseurs de soins obstétricaux des répercussions, pour la mère, le fœtus et le nouveau-né, des exercices de conditionnement aerobique et musculaire pendant la grossesse. RéSULTATS ATTENDUS: Effets sur la morbidité maternelle, fœtale et néonatale et mesures de la forme physique maternelle. Une recherche sur MEDLINE des articles, publiés en anglais de 1966 à 2002, appartenant aux catégories suivantes : études sur le conditionnement aérobique et musculaire chez des femmes ne faisant pas jusque-là d'exercice et chez des femmes actives avant leur grossesse, ainsi que des études sur les répercussions du conditionnement aérobique et musculaire sur les issues précoces et tardives de la grossesse ou sur les issues néonatales; rapports de synthèse et méta-analyses portant sur l'exercice pendant la grossesse. Les résultats recueillis ont été revus par la Société des obstétriciens et gynécologues du Canada (Comité de la pratique clinique - obstétrique), avec la participation de la Société canadienne de physiologie de l'exercice, et ils ont été classés suivant les critères d'évaluation des preuves établis par le Groupe de travail canadien sur l'examen de santé périodique. VALIDATION: Cette directive a été approuvée par le Comité de pratique clinique - obstétrique de la SOGC, par le Comité exécutif et par le Conseil de la SOGC, ainsi que par le Conseil d'administration de la Société canadienne de physiologie de l'exercice. PARRAINé PAR: la Société des obstétriciens et gynécologues du Canada et par la Société canadienne de physiologie de l'exercice. Copyright © 2018. Published by Elsevier Inc.

  3. Bioreducible poly(amido amine)s for non-viral gene delivery

    NARCIS (Netherlands)

    Lin, C.

    2008-01-01

    This thesis describes the design and development of bioreducible poly(amido amine)s as non-viral vectors for gene delivery in vitro and in vivo. The structural influences of these polymers on their physico-chemical properties and gene delivery properties, transfection capability and cytotoxicity in

  4. BIOGENIC AMINES CONTENT IN DIFFERENT WINE SAMPLES

    Directory of Open Access Journals (Sweden)

    Attila Kántor

    2015-02-01

    Full Text Available Twenty-five samples of different Slovak wines before and after filtration were analysed in order to determine the content of eight biogenic amines (tryptamine, phenylalanine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine. The method involves extraction of biogenic amines from wine samples with used dansyl chloride. Ultra-high performance liquid chromatography (UHPLC was used for determination of biogenic amines equipped with a Rapid Resolution High Definition (RRHD, DAD detectors and Extend-C18 LC column (50 mm x 3.0 mm ID, 1.8 μm particle size. In this study the highest level of biogenic amine in all wine samples represent tryptamine (TRM with the highest content 170.9±5.3 mg/L in Pinot Blanc wine. Phenylalanine (PHE cadaverine (CAD, histamine (HIS and spermidine (SPD were not detected in all wines; mainly SPD was not detected in 16 wines, HIS not detected in 14 wines, PHE and CAD not detected in 2 wines. Tyramine (TYR, spermine (SPN and putrescine (PUT were detected in all wines, but PUT and SPN in very low concentration. The worst wine samples with high biogenic amine content were Saint Laurent (BF, Pinot Blanc (S and Pinot Noir (AF.

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

    International Nuclear Information System (INIS)

    Sayyed, Maheboob M.; Maldar, Noormahmad N.

    2010-01-01

    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.

  6. Local coordination of Eu(III) in organic/inorganic amine functionalized hybrids

    International Nuclear Information System (INIS)

    Carlos, L.D.; Sa Ferreira, R.A.; Goncalves, M.C.; Zea Bermudez, V. de

    2004-01-01

    The sol-gel method was used to prepare two families of organic/inorganic hybrids incorporating europium triflate, classed as di-urethanesils and aminosils. A siliceous network to which short polyether chains are covalently bonded through urethane linkages, composes the di-urethanesil host. A siliceous network containing pendant amine terminated propyl chains, forms the aminosils. The xerogels were investigated by photoluminescence, particularly the local interaction between the Eu 3+ ions and the host matrix. The Eu 3+ local coordination was modelled in terms of a local-field perturbation representing the ion's nearest ligands interaction potential. While for the aminosils the Eu 3+ ions occupy one low-symmetry local site--crystal-field strength of ca. 760.5 cm -1 and 5 D 0 lifetime of 0.6-0.7 ms--two local Eu 3+ environments with distinct point symmetry group, 5 D 0 lifetimes (ca. 0.2-0.3 and 1.4-1.8 ms, respectively) and covalent nature--crystal-field strengths of ca. 540 and 740-780 cm -1 , respectively--were identified in the di-urethanesils

  7. Extraction of some acids using aliphatic amines

    International Nuclear Information System (INIS)

    Matutano, L.

    1964-06-01

    Hydrochloric, nitric, sulphuric, perchloric, phosphoric, acetic and formic acids in aqueous solution (0.05 to 10 M) are extracted by amberlite LA2 and trilaurylamine in solution, 5 per cent by volume, in kerosene and xylene respectively. The extraction process consists of: neutralization of the amine salt; a 'molecular extraction', i.e. an extraction using an excess of acid with respect to the stoichiometry of the amine salt. According to the behaviour of the acid during the extraction, three groups may be distinguished: completely dissociated acids, carboxylic acids, phosphoric acid. This classification is also valid for the extraction of the water which occurs simultaneously with that of the acid. An extraction mechanism is put forward for formic acid and the formation constant of its amine salt is calculated. (author) [fr

  8. Base metal dehydrogenation of amine-boranes

    Science.gov (United States)

    Blacquiere, Johanna Marie [Ottawa, CA; Keaton, Richard Jeffrey [Pearland, TX; Baker, Ralph Thomas [Los Alamos, NM

    2009-06-09

    A method of dehydrogenating an amine-borane having the formula R.sup.1H.sub.2N--BH.sub.2R.sup.2 using base metal catalyst. The method generates hydrogen and produces at least one of a [R.sup.1HN--BHR.sup.2].sub.m oligomer and a [R.sup.1N--BR.sup.2].sub.n oligomer. The method of dehydrogenating amine-boranes may be used to generate H.sub.2 for portable power sources, such as, but not limited to, fuel cells.

  9. Catalyst for hydrogen-amine D exchange

    International Nuclear Information System (INIS)

    Holtslander, W.J.; Johnson, R.E.

    1976-01-01

    A process is claimed for deuterium isotopic enrichment (suitable for use in heavy water production) by amine-hydrogen exchange in which the exchange catalyst comprises a mixture of alkyl amides of two metals selected from the group consisting of the alkali metals. Catalyst mixtures comprising at least one of the alkali amides of lithium and potassium are preferred. At least one of the following benefits are obtained: decreased hydride formation, decreased thermal decomposition of alkyl amide, increased catalyst solubility in the amine phase, and increased exchange efficiency. 11 claims

  10. Corrosion inhibition of brass by aliphatic amines

    International Nuclear Information System (INIS)

    Taha, K. K.; Sheshadri, B. S; Ahmed, M. F.

    2005-01-01

    Aliphatic amines hexylamine (HCA), octylamine (OCA) and decylamine (DCA) have been used as corrosion inhibitors for (70/30) brass in 0.I M HCIO 4 . The inhibitor efficiency (%P) calculated using weight loss, Tafel extrapolation, linear polarization and impedance methods was found to be in the order DCA> OCA> HCA. These adsorb on brass surface following bockris-swinkels' isotherm. DCA, OCA and HCA displaced 4, 3 and 2 molecules of water from interface respectively. Displacement of water molecules brought a great reorganization of double layer at the interface. These amines during corrosion form complexes with dissolved zinc and copper ions.(Author)

  11. Extraction of uranyl sulfate with primary amine

    International Nuclear Information System (INIS)

    Mrnka, M.; Bizek, V.; Nekovar, P.; Cizevska, S.; Schroetterova, D.

    1984-01-01

    PRIMENE JM-T was used for extraction. Its composition was found to approach the general formula C 21 H 43 NH 2 . It was found that the extraction of uranyl sulfate is lower in case of a higher steady-state concentration of sulfuric acid in the aqueous phase. Extraction is accompanied with coextraction of water. The results obtained showed that uranyl sulfate passes into the organic phase by two mechanisms: extraction with amine sulfate and extraction with free amine. A mathematical description of the process was made based on the obtained results. (E.S.)

  12. Enantioselective catalytic syntheses of alpha-branched chiral amines

    DEFF Research Database (Denmark)

    Brase, S.; Baumann, T.; Dahmen, S.

    2007-01-01

    Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials.......Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials....

  13. SEDIMENT-ASSOCIATED REACTIONS OF AROMATIC AMINES. 2. QSAR DEVELOPMENT

    Science.gov (United States)

    The fate of aromatic amines in soils and sediments is dominated by irreversible binding through nucleophilic addition and oxidative radical coupling. Despite the common occurrence of the aromatic amine functional group in organic chemicals, the molecular properties useful for pr...

  14. Ionic solubility and solutal advection governed augmented evaporation kinetics of salt solution pendant droplets

    Science.gov (United States)

    Jaiswal, Vivek; Harikrishnan, A. R.; Khurana, Gargi; Dhar, Purbarun

    2018-01-01

    The presence of dispersed inclusions is known to modify the interfacial characteristics in liquids by adsorption-desorption of the ions at interfaces. The present article reports the influencing role of dissolved ions in a polar fluid on its evaporation dynamics. The evaporation dynamics of pendant droplets of aqueous solutions of variant simple salts and concentrations have been experimentally studied. The presence of salts is observed to enhance the evaporation rate (obeying the classical D2 law), and the enhancement has been found to hold a direct proportionality to the concentration of the dissolved salt. Furthermore, it is observed that the degree of enhancement in the evaporation rate is also directly proportional to the solubility of the salt in question. The phenomenon is explained based on the chemical kinetics and thermodynamics of hydration of the ionic species in the polar fluid. The classical evaporation rate constant formulation is found to be inadequate in modeling the enhanced species transport. Additional probing via particle image velocimetry reveals augmented internal circulation within the evaporating salt based drops compared to pure water. Mapping the dynamic surface tension reveals that a salt concentration gradient is generated between the bulk and periphery of the droplet and it could be responsible for the internal advection cells visualized. A thermo-solutal Marangoni and Rayleigh convection based mathematical formulation has been put forward, and it is shown that the enhanced solute-thermal convection could play a major role in enhanced evaporation. The internal circulation mapped from experiments is found to be in good quantitative agreement with the model predictions. Scaling analysis further reveals that the stability of the solutal Marangoni convection surpasses the thermal counterpart with higher salt concentration and solubility. The present article sheds insight into the possible domineering role of conjugate thermohydraulic and

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

    International Nuclear Information System (INIS)

    Wang Dong; Li Hua; Li Najun; Zhao Ying; Zhou Qianhao; Xu Qingfeng; Lu Jianmei; Wang Lihua

    2012-01-01

    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 10 5 . ► 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 10 5 and can endure 10 8 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 the mechanism of the DRAM performance may be attributed to the weak electron withdrawing ability of the molecule.

  16. Polar bears, Ursus maritimus

    Science.gov (United States)

    Rode, Karyn D.; Stirling, Ian

    2017-01-01

    Polar bears are the largest of the eight species of bears found worldwide and are covered in a pigment-free fur giving them the appearance of being white. They are the most carnivorous of bear species consuming a high-fat diet, primarily of ice-associated seals and other marine mammals. They range throughout the circumpolar Arctic to the southernmost extent of seasonal pack ice.

  17. EcoBears

    DEFF Research Database (Denmark)

    Nielsen, Nick; Pedersen, Sandra Bleuenn; Sørensen, Jens Ager

    2015-01-01

    In this paper, we introduce the EcoBears concept that aims to augment household appliances with functional and aesthetic features to promote their "use'' and "longevity of use'' to prevent their disposal. The EcoBears also aim to support the communication of environmental issues in the home setting....... We present our initial design and implementation of the EcoBears that consist of two bear modules (a mother and her cub). We also present our preliminary concept validations and lessons learned to be considered for future directions....

  18. Bearing restoration by grinding

    Science.gov (United States)

    Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

    1976-01-01

    A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

  19. Polar bears at risk

    Energy Technology Data Exchange (ETDEWEB)

    Norris, S.; Rosentrater, L.; Eid, P.M. [WWF International Arctic Programme, Oslo (Norway)

    2002-05-01

    Polar bears, the world's largest terrestrial carnivore, spend much of their lives on the arctic sea ice. This is where they hunt and move between feeding, denning, and resting areas. The world population, estimated at 22,000 bears, is made up of 20 relatively distinct populations varying in size from a few hundred to a few thousand animals. About 60 per cent of all polar bears are found in Canada. In general, the status of this species is stable, although there are pronounced differences between populations. Reductions in the extent and thickness of sea ice has lead the IUCN Polar Bear Specialist Group to describe climate change as one of the major threats facing polar bears today. Though the long-term effects of climate change will vary in different areas of the Arctic, impacts on the condition and reproductive success of polar bears and their prey are likely to be negative. Longer ice-free periods resulting from earlier break-up of sea ice in the spring and later formation in the fall is already impacting polar bears in the southern portions of their range. In Canada's Hudson Bay, for example, bears hunt on the ice through the winter and into early summer, after which the ice melts completely, forcing bears ashore to fast on stored fat until freeze-up in the fall. The time bears have on the ice to hunt and build up their body condition is cut short when the ice melts early. Studies from Hudson Bay show that for every week earlier that ice break-up occurs, bears will come ashore 10 kg lighter and in poorer condition. It is likely that populations of polar bears dividing their time between land and sea will be severely reduced and local extinctions may occur as greenhouse gas emissions continue to rise and sea ice melts. Expected changes in regional weather patterns will also impact polar bears. Rain in the late winter can cause maternity dens to collapse before females and cubs have departed, thus exposing occupants to the elements and to predators. Such

  20. Reductive amination with zinc powder in aqueous media

    Directory of Open Access Journals (Sweden)

    Giovanni B. Giovenzana

    2011-08-01

    Full Text Available Zinc powder in aqueous alkaline media was employed to perform reductive amination of aldehydes with primary amines. The corresponding secondary amines were obtained in good yields along with minor amounts of hydrodimerization byproducts. The protocol is a green alternative to the use of complex hydrides in chlorinated or highly flammable solvents.

  1. Direct electrochemical imidation of aliphatic amines via anodic oxidation.

    Science.gov (United States)

    Zhang, Li; Su, Ji-Hu; Wang, Sujing; Wan, Changfeng; Zha, Zhenggen; Du, Jiangfeng; Wang, Zhiyong

    2011-05-21

    Direct electrochemical synthesis of sulfonyl amidines from aliphatic amines and sulfonyl azides was realized with good to excellent yields. Traditional tertiary amine substrates were broadened to secondary and primary amines. The reaction intermediates were observed and a reaction mechanism was proposed and discussed. © The Royal Society of Chemistry 2011

  2. The Synthesis of Methyl Salicylate: Amine Diazotization.

    Science.gov (United States)

    Zanger, Murray; McKee, James R.

    1988-01-01

    Notes that this experiment takes safety and noncarcinogenic reactants into account. Demonstrates the use of diazonium salts for the replacement of an aromatic amine group by a phenolic hydroxyl. Involves two pleasant-smelling organic compounds, methyl anthranilate (grape) and methyl salicylate (oil of wintergreen). (MVL)

  3. Microbiological, physicochemical properties and biogenic amine ...

    African Journals Online (AJOL)

    Thirty three strained yoghurt samples were collected from local open markets in different provinces of Turkey (Afyon [AF], Aydın [AY], Burdur [B], Isparta [I] and Muğla [M]). Physicochemical and microbiological properties, as well as biogenic amine content, were examined in each of the samples. The dry matter (17.90 to ...

  4. Direct amination of secondary alcohols using Ammonia

    NARCIS (Netherlands)

    Pingen, D.L.L.; Müller, C.; Vogt, D.

    2010-01-01

    Hydrogen shuttle: For the first time secondary alcohols and ammonia can be directly converted into primary amines with a selectivity of up to 99¿% by using a simple ruthenium/phosphine catalyst (see scheme; R1, R2= alkyl, aryl, alkenyl; M=[Ru3(CO)12]; and L=phosphine ligand).

  5. Direct Amination of alpha-Hydroxy Amides

    NARCIS (Netherlands)

    Chandgude, Ajay L.; Dömling, Alexander

    A TiCl4-mediated reaction for the direct amination of alpha-hydroxy amides has been developed. This simple, general, additive/base/ligand-free reaction is mediated by economical TiCl4. The reaction runs under mild conditions. This highly efficient C-N bond formation protocol is valid for diverse

  6. Uranium diphosphonates templated by interlayer organic amines

    International Nuclear Information System (INIS)

    Nelson, Anna-Gay D.; Alekseev, Evgeny V.; Albrecht-Schmitt, Thomas E.; Ewing, Rodney C.

    2013-01-01

    The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a variety of amines (2,2-dipyridyl, triethylenediamine, ethylenediamine, and 1,10-phenanthroline) at 200 °C results in the crystallization of a series of layered uranium diphosphonate compounds, [C 10 H 9 N 2 ]{UO 2 (H 2 O)[CH 2 (PO 3 )(PO 3 H)]} (Ubip2), [C 6 H 14 N 2 ]{(UO 2 ) 2 [CH 2 (PO 3 )(PO 3 H)] 2 ·2H 2 O} (UDAB), [C 2 H 10 N 2 ] 2 {(UO 2 ) 2 (H 2 O) 2 [CH 2 (PO 3 ) 2 ] 2 ·0.5H 2 O} (Uethyl), and [C 12 H 9 N 2 ]{UO 2 (H 2 O)[CH 2 (PO 3 )(PO 3 H)]} (Uphen). The crystal structures of the compounds are based on UO 7 units linked by methylenediphosphonate molecules to form two-dimensional anionic sheets in Ubip2 and UDAB, and one-dimensional anionic chains in Uethyl and Uphen, which are charge balanced by protonated amine molecules. Interaction of the amine molecules with phosphonate oxygens and water molecules results in extensive hydrogen bonding in the interlayer. These amine molecules serve both as structure-directing agents and charge-balancing cations for the anionic uranium phosphonate sheets and chains in the formation of the different coordination geometries and topologies of each structure. Reported herein are the syntheses, structural and spectroscopic characterization of the synthesized compounds. - Graphical abstract: The Raman spectra of the synthesized compounds and an illustration of the stacking of the layers with the diprotonated triethylenediamine molecules in [C 6 H 14 N 2 ]{(UO 2 ) 2 [CH 2 (PO 3 )(PO 3 H)] 2 ·2H 2 O} UDAB. Solvent water molecules are removed for clarity. The corresponding Raman spectra for the complexes synthesized is also shown. The structure is constructed from UO 7 pentagonal bipyramids (yellow), oxygen=red, phosphorus=magenta, carbon=black, and nitrogen=blue. Highlights: ► Organic amines act both as charge-balancing and as structure-directing agents. ► Extensive hydrogen bonding interactions with solvent water molecules and amines

  7. Intolerance to dietary biogenic amines: a review.

    Science.gov (United States)

    Jansen, Sophia C; van Dusseldorp, Marijke; Bottema, Kathelijne C; Dubois, Anthony E J

    2003-09-01

    To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and adverse. Additionally, the keywords histamine, tyramine, and phenylethylamine were combined with headache, migraine, urticaria, oral challenge, and oral provocation. Articles were also selected from references in relevant literature. Only oral challenge studies in susceptible patients were considered. Studies with positive results (ie, studies in which an effect was reported) were only eligible when a randomized, double-blind, placebo-controlled design was used. Eligible positive result studies were further evaluated according to a number of scientific criteria. Studies with negative results (ie, studies in which no effect was reported) were examined for factors in their design or methods that could be responsible for a false-negative outcome. Results of methodologically weak or flawed studies were considered inconclusive. A total of 13 oral challenge studies (5 with positive results and 8 with negative results) were found. Three of them (all with positive results) were considered ineligible. By further evaluation of the 10 eligible studies, 6 were considered inconclusive. The 4 conclusive studies all reported negative results. One conclusive study showed no relation between biogenic amines in red wine and wine intolerance. Two conclusive studies found no effect of tyramine on migraine. One conclusive study demonstrated no relation between the amount of phenylethylamine in chocolate and headache attacks in individuals with headache. The current scientific literature shows no relation between the oral ingestion of biogenic amines and food intolerance reactions. There is therefore no scientific basis for dietary recommendations concerning biogenic amines in such patients.

  8. Reprint of: Pendant allyl crosslinking as a tunable shape memory actuator for vascular applications.

    Science.gov (United States)

    Boire, Timothy C; Gupta, Mukesh K; Zachman, Angela L; Lee, Sue Hyun; Balikov, Daniel A; Kim, Kwangho; Bellan, Leon M; Sung, Hak-Joon

    2016-04-01

    Thermo-responsive shape memory polymers (SMPs) can be programmed to fit into small-bore incisions and recover their functional shape upon deployment in the body. This property is of significant interest for developing the next generation of minimally-invasive medical devices. To be used in such applications, SMPs should exhibit adequate mechanical strengths that minimize adverse compliance mismatch-induced host responses (e.g. thrombosis, hyperplasia), be biodegradable, and demonstrate switch-like shape recovery near body temperature with favorable biocompatibility. Combinatorial approaches are essential in optimizing SMP material properties for a particular application. In this study, a new class of thermo-responsive SMPs with pendant, photocrosslinkable allyl groups, x%poly(ε-caprolactone)-co-y%(α-allyl carboxylate ε-caprolactone) (x%PCL-y%ACPCL), are created in a robust, facile manner with readily tunable material properties. Thermomechanical and shape memory properties can be drastically altered through subtle changes in allyl composition. Molecular weight and gel content can also be altered in this combinatorial format to fine-tune material properties. Materials exhibit highly elastic, switch-like shape recovery near 37 °C. Endothelial compatibility is comparable to tissue culture polystyrene (TCPS) and 100%PCL in vitro and vascular compatibility is demonstrated in vivo in a murine model of hindlimb ischemia, indicating promising suitability for vascular applications. With the ongoing thrust to make surgeries minimally-invasive, it is prudent to develop new biomaterials that are highly compatible and effective in this workflow. Thermo-responsive shape memory polymers (SMPs) have great potential for minimally-invasive applications because SMP medical devices (e.g. stents, grafts) can fit into small-bore minimally-invasive surgical devices and recover their functional shape when deployed in the body. To realize their potential, it is imperative to devise

  9. Pendant allyl crosslinking as a tunable shape memory actuator for vascular applications.

    Science.gov (United States)

    Boire, Timothy C; Gupta, Mukesh K; Zachman, Angela L; Lee, Sue Hyun; Balikov, Daniel A; Kim, Kwangho; Bellan, Leon M; Sung, Hak-Joon

    2015-09-01

    Thermo-responsive shape memory polymers (SMPs) can be programmed to fit into small-bore incisions and recover their functional shape upon deployment in the body. This property is of significant interest for developing the next generation of minimally-invasive medical devices. To be used in such applications, SMPs should exhibit adequate mechanical strengths that minimize adverse compliance mismatch-induced host responses (e.g. thrombosis, hyperplasia), be biodegradable, and demonstrate switch-like shape recovery near body temperature with favorable biocompatibility. Combinatorial approaches are essential in optimizing SMP material properties for a particular application. In this study, a new class of thermo-responsive SMPs with pendant, photocrosslinkable allyl groups, x%poly(ε-caprolactone)-co-y%(α-allyl carboxylate ε-caprolactone) (x%PCL-y%ACPCL), are created in a robust, facile manner with readily tunable material properties. Thermomechanical and shape memory properties can be drastically altered through subtle changes in allyl composition. Molecular weight and gel content can also be altered in this combinatorial format to fine-tune material properties. Materials exhibit highly elastic, switch-like shape recovery near 37°C. Endothelial compatibility is comparable to tissue culture polystyrene (TCPS) and 100%PCL in vitro and vascular compatibility is demonstrated in vivo in a murine model of hindlimb ischemia, indicating promising suitability for vascular applications. With the ongoing thrust to make surgeries minimally-invasive, it is prudent to develop new biomaterials that are highly compatible and effective in this workflow. Thermo-responsive shape memory polymers (SMPs) have great potential for minimally-invasive applications because SMP medical devices (e.g. stents, grafts) can fit into small-bore minimally-invasive surgical devices and recover their functional shape when deployed in the body. To realize their potential, it is imperative to devise

  10. Synthesis of Ethylene or Propylene/1,3-Butadiene Copolymers Possessing Pendant Vinyl Groups with Virtually No Internal Olefins

    Directory of Open Access Journals (Sweden)

    Kenji Michiue

    2015-11-01

    Full Text Available In general, ethylene/1,3-butadiene copolymerizations provides copolymers possessing both pendant vinyls and vinylenes as olefinic moieties. We, at MCI, studied the substituent effects of C2-symmetric zirconocene complexes, rac-[Me2Si(Indenyl’2]ZrCl2 (Indenyl’ = generic substituted indenyl, after activation on the ratio of the pendant vinyls and vinylenes of the resultant copolymers. Complexes examined in this study were rac-dimethylsilylbis (1-indenylzirconium dichloride (1, rac-dimethylsilyl-bis[1-(2-methyl-4,5-benzoindenyl] zirconium dichloride (2, rac-dimethylsilyl-bis[l-(2-methyl -4-phenylindenyl]zirconium dichloride (3, rac-dimethy1si1y1- bis(2-ethyl-4-phenylindenyl zirconium dichloride (4, rac-dimethylsilyl-bis[l-(2-n-propyl -4-(1-naphthylindenyl]zirconium dichloride (5, rac-dimethylsilyl-[1-(2-ethyl-4-(5-(2,2-dimethyl-2,3-dihydro-1H-cyclopenta [a]naphthalenylindenyl][1-(2-n-propyl-4-(5-(2,2-dimethyl-2,3-dihydro-1H-cyclopenta[a] naphthalenylindenyl]zirconium dichloride (6, rac-dimethylsilyl-bis[1-(2-ethyl-4-(9-phenanthrylindenyl]zirconium dichloride (7, and rac-dimethylsilyl-bis[l-(2-n-propyl-4-(9-phenanthrylindenyl]zirconium dichloride (8. We found that the ratio of the pendant vinyls and vinylenes is strongly affected by the bulkiness of the substituent on the complexes examined. The vinyl content increased linearly in the following order, 8 > 7 > 6 > 5 > 4 > 3 > 2 > 1. Notably, complex 8/DMAO formed ethylene/1,3-butadiene copolymers possessing predominant vinyl groups, which can be crucial precursors for functionalized polyolefins. Likewise, complex 8/DMAO afforded propylene/1,3-butadiene copolymers with predominant vinyl groups.

  11. Extraction of sulphates by long chain amines; Extraction des sulfates par les amines a longues chaines

    Energy Technology Data Exchange (ETDEWEB)

    Boirie, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-05-15

    The extraction of sulphuric acid by long chain amines in organic solution has been studied with a view to determining the value of the stability constants of the amine sulphates and bi-sulphates formed. We have concentrated chiefly on uranium sulphate and thorium sulphate. The formulae of the complexes extractable with amines have been established, as well as the corresponding dissociation constants. We have observed that for uranium sulphate the formula of the complex depends only on the nature of the amine, whereas for thorium this formula varies with the amine structure. From the formulae determined and the value of the constants calculated, we have been able to establish the best conditions for uranium and thorium extraction and also for a separation of these two elements. Finally we propose an application of this study to the determination of uranium in ores, where the separation of uranium by this method is particularly easy and complete. (author) [French] L'extraction de l'acide sulfurique par des amines a longues chaines en solution organique a ete etudiee en vue de la determination de la valeur des constantes de stabilite des sulfates et bisulfates d'amines formes. Parmi les sulfates, nous nous sommes particulierement interesses au sulfate d'uranium et au sulfate de thorium. Nous avons determine les formules des complexes extractibles avec les amines, ainsi que les constantes de dissociation correspondantes. Nous avons remarque que pour le sulfate d'uranium, la formule du complexe ne depend que de la nature de l'amine, alors que pour le thorium cette formule varie avec la structure de l'amine. Les formules determinees et la valeur des constantes calculees, nous ont permis de decrire les meilleures conditions d'extraction de l'uranium et du thorium ainsi que celles d'une separation de ces deux elements. Nous proposons enfin une application de cette etude au dosage de l'uranium dans les minerais, ou la separation de l'uranium par cette methode est

  12. A cluster randomized trial to determine the effectiveness of a novel, digital pendant and voice reminder platform on increasing infant immunization adherence in rural Udaipur, India.

    Science.gov (United States)

    Nagar, Ruchit; Venkat, Preethi; Stone, Logan D; Engel, Kyle A; Sadda, Praneeth; Shahnawaz, Mohammed

    2017-11-18

    Five hundred thousand children under the age of 5 die from vaccine preventable diseases in India every year. More than just improving coverage, increasing timeliness of immunizations is critical to ensuring infant health in the first year of life. Novel, culturally appropriate community engagement strategies are worth exploring to close the immunization gap. In our study, a digital NFC (Near Field Communication) pendant worn on black thread and voice call reminder system was tested for the effectiveness in improving DTP3 adherence within 2 monthly camps from DTP1 administration. A cluster randomized controlled trial was conducted in which 96 village health camps were randomized to 3 arms: NFC sticker, NFC pendant, and NFC pendant with voice call reminder in local dialect. Randomization was done across 5 blocks in the Udaipur District serviced by Seva Mandir from August 2015 to April 2016. In terms of our three primary outcomes related to DTP3 adherence, point estimates show conflicting results. Two outcomes presented adherence in the control. DTP3 completion within two camps after DTP1 showed higher adherence in the Control (Sticker) (74.2%) arm compared to the Pendant (67.2%) and Pendant and Voice arms (69.3%). Likewise, the estimate for DTP3 completion within 180 days of birth in the Control (Sticker) (69.4%) arm was higher than estimates in the Pendant (57.4%) and Pendant and Voice arms (58.7%). However, one outcome displayed higher adherence in the intervention. DTP3 completion within two months from the time of registration was higher in the Pendant (37.7%) and Pendant and Voice arms (38.7%) compared to the Control (Sticker) arm (27.4%). In all primary outcomes, differences in adherence were statistically insignificant both before and after controlling for confounding factors. In terms of secondary outcomes, our results suggest that providing a necklace generated significant community discussion (H = 8.8796, df = 2, p = .0118), had strong

  13. Extraction of some acids using aliphatic amines; Extraction de quelques acides par des amines aliphatiques

    Energy Technology Data Exchange (ETDEWEB)

    Matutano, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-06-01

    Hydrochloric, nitric, sulphuric, perchloric, phosphoric, acetic and formic acids in aqueous solution (0.05 to 10 M) are extracted by amberlite LA2 and trilaurylamine in solution, 5 per cent by volume, in kerosene and xylene respectively. The extraction process consists of: neutralization of the amine salt; a 'molecular extraction', i.e. an extraction using an excess of acid with respect to the stoichiometry of the amine salt. According to the behaviour of the acid during the extraction, three groups may be distinguished: completely dissociated acids, carboxylic acids, phosphoric acid. This classification is also valid for the extraction of the water which occurs simultaneously with that of the acid. An extraction mechanism is put forward for formic acid and the formation constant of its amine salt is calculated. (author) [French] Les acides chlorhydrique, nitrique, sulfurique, perchlorique, phosphorique, acetique et formique, en solution aqueuse - 0,05 a 10 M - sont extraits par l'amberlite LA2 et la trilaurylamine en solution, a 5 pour cent en volume, dans le kerosene et le xylene respectivement. L'extraction comprend: une neutralisation de l'amine par l'acide avec formation d'un sel d'amine; une 'extraction moleculaire', c'est-a-dire une extraction d'acide en exces par rapport a la stoechiometrie du sel d'amine. Suivant le comportement des acides au cours de l'extraction nous distinguons trois groupes: acides entierement dissocies, acides carboxyliques, acide phosphorique. Cette classification est egalement valable pour l'extraction de l'eau qui est simultanee a celle de l'acide. Un mecanisme d'extraction pour l'acide formique est propose et nous calculons la constante de formation de son sel d'amine. (auteur)

  14. Metabolism and Biomarkers of Heterocyclic Aromatic Amines in Molecular Epidemiology Studies: Lessons Learned from Aromatic Amines

    Science.gov (United States)

    2011-01-01

    Aromatic amines and heterocyclic aromatic amines (HAAs) are structurally related classes of carcinogens that are formed during the combustion of tobacco or during the high-temperature cooking of meats. Both classes of procarcinogens undergo metabolic activation by N-hydroxylation of the exocyclic amine group, to produce a common proposed intermediate, the arylnitrenium ion, which is the critical metabolite implicated in toxicity and DNA damage. However, the biochemistry and chemical properties of these compounds are distinct and different biomarkers of aromatic amines and HAAs have been developed for human biomonitoring studies. Hemoglobin adducts have been extensively used as biomarkers to monitor occupational and environmental exposures to a number of aromatic amines; however, HAAs do not form hemoglobin adducts at appreciable levels and other biomarkers have been sought. A number of epidemiologic studies that have investigated dietary consumption of well-done meat in relation to various tumor sites reported a positive association between cancer risk and well-done meat consumption, although some studies have shown no associations between well-done meat and cancer risk. A major limiting factor in most epidemiological studies is the uncertainty in quantitative estimates of chronic exposure to HAAs and, thus, the association of HAAs formed in cooked meat and cancer risk has been difficult to establish. There is a critical need to establish long-term biomarkers of HAAs that can be implemented in molecular epidemioIogy studies. In this review article, we highlight and contrast the biochemistry of several prototypical carcinogenic aromatic amines and HAAs to which humans are chronically exposed. The biochemical properties and the impact of polymorphisms of the major xenobiotic-metabolizing enzymes on the biological effects of these chemicals are examined. Lastly, the analytical approaches that have been successfully employed to biomonitor aromatic amines and HAAs, and

  15. Ultra-precision bearings

    CERN Document Server

    Wardle, F

    2015-01-01

    Ultra-precision bearings can achieve extreme accuracy of rotation, making them ideal for use in numerous applications across a variety of fields, including hard disk drives, roundness measuring machines and optical scanners. Ultraprecision Bearings provides a detailed review of the different types of bearing and their properties, as well as an analysis of the factors that influence motion error, stiffness and damping. Following an introduction to basic principles of motion error, each chapter of the book is then devoted to the basic principles and properties of a specific type of bearin

  16. Deuterium exchange between hydrofluorocarbons and amines

    International Nuclear Information System (INIS)

    Hammond, W.B.; Bigeleisen, J.; Tuccio, S.A.

    1983-01-01

    The invention consists of a process for obtaining a compound enriched in deuterium which comprises the known method of exposing a gaseous hydrofluorocarbon to infrared laser radiation of a predetermined frequency to selectively cause a chemical reaction involving hydrofluorocarbon molecules containing deuterium without substantially affecting hydrofluorocarbon molecules not containing deuterium, thereby producing, as reaction products, a compound enriched in deuterium and hydrofluorocarbon depleted in deuterium; combined with a new method, which comprises enriching the deuterium content of the depleted hydrofluorocarbon by contacting the depleted hydrofluorocarbon with an alkali metal amide and an amine having a concentration of deuterium at least that which will yield an increase in deuterium concentration of the hydrofluorocarbon upon equilibration, whereby the amine becomes depleted in deuterium

  17. Amine chemistry. Update on impact on resin

    International Nuclear Information System (INIS)

    Bachman, Gregory; Kellogg, Douglas; Wilkes, Marty

    2012-01-01

    Impurity removal in the steam cycle and the associated prevention of corrosion and/or fouling of system components are the goals of ion exchange resins. However, in many instances (such as a switch to amine chemistry or a change in product specifications), resins do not remove, and, in fact, contribute impurities to the steam cycle. This paper reviews recent data compiled to determine the direct and indirect effects of amines on ion exchange resins used in the power industry. Water chemistries have improved in recent years, in large part due to changes in chemistry and resins, but it is necessary to continue to develop products, processes and techniques to reduce impurities and improve overall water chemistry in power plant systems. (orig.)

  18. Amine chemistry. Update on impact on resin

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, Gregory; Kellogg, Douglas [Siemens Industry, Inc., Rockford, IL (United States). Technology and Lab Services; Wilkes, Marty [Siemens Industry, Inc., Rockford, IL (United States). Water Technologies Div.

    2012-03-15

    Impurity removal in the steam cycle and the associated prevention of corrosion and/or fouling of system components are the goals of ion exchange resins. However, in many instances (such as a switch to amine chemistry or a change in product specifications), resins do not remove, and, in fact, contribute impurities to the steam cycle. This paper reviews recent data compiled to determine the direct and indirect effects of amines on ion exchange resins used in the power industry. Water chemistries have improved in recent years, in large part due to changes in chemistry and resins, but it is necessary to continue to develop products, processes and techniques to reduce impurities and improve overall water chemistry in power plant systems. (orig.)

  19. Ruthenium-Catalyzed Aerobic Oxidation of Amines.

    Science.gov (United States)

    Ray, Ritwika; Hazari, Arijit Singha; Lahiri, Goutam Kumar; Maiti, Debabrata

    2018-01-18

    Amine oxidation is one of the fundamental reactions in organic synthesis as it leads to a variety of value-added products such as oximes, nitriles, imines, and amides among many others. These products comprise the key N-containing building blocks in the modern chemical industry, and such transformations, when achieved in the presence of molecular oxygen without using stoichiometric oxidants, are much preferred as they circumvent the production of unwanted wastes. In parallel, the versatility of ruthenium catalysts in various oxidative transformations is well-documented. Herein, this review focuses on aerobic oxidation of amines specifically by using ruthenium catalysts and highlights the major achievements in this direction and challenges that still need to be addressed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Rate phenomena in uranium extraction by amines

    International Nuclear Information System (INIS)

    Coleman, C.F.; McDowell, W.J.

    1979-01-01

    Kinetics studies and other rate measurements are reviewed in the amine extraction of uranium and of some other related and associated metal ions. Equilibration is relatively fast in the uranium sulfate systems most important to uranium hydrometallurgy. Significantly slow equilibration has been encountered in some other systems. Most of the recorded rate information, both qualitative and quantitative, has come from exploratory and process-development work, while some kinetics studies have been directed specifically toward elucidation of extraction mechanisms. 71 references

  1. η6-Arene complexes of ruthenium and osmium with pendant donor functionalities

    KAUST Repository

    Reiner, Thomas

    2010-11-01

    Conversion of 4′-(2,5-dihydrophenyl)butanol or N-trifluoroacetyl-2,5- dihydrobenzylamine with MCl3·n H2O (M = Ru, Os) affords the corresponding dimeric η6-arene complexes in good to excellent yields. Under similar reaction conditions, the amine functionalized arene precursor 2,5-dihydrobenzylamine yields the corresponding Ru(II) complex. For osmium, HCl induced oxidation leads to formation of [OsCl6] 2- salts. However, under optimized reaction conditions, conversion of the precursor 2,5-dihydrobenzylamine chloride results in clean formation of η6-arene Os(II) complex. X-ray structures of [(η6- benzyl ammonium)(dmso)RuCl2] and (2,5-dihydrobenzyl ammonium) 4[OsCl6]2confirm the spectroscopic data. High stability towards air and acid as well as enhanced solubility in water is observed for all η6-arene complexes. © 2010 Elsevier B.V. All rights reserved.

  2. Roller bearing geometry design

    Science.gov (United States)

    Savage, M.; Pinkston, B. H. W.

    1976-01-01

    A theory of kinematic stabilization of rolling cylinders is extended and applied to the design of cylindrical roller bearings. The kinematic stabilization mechanism puts a reverse skew into the rolling elements by changing the roller taper. Twelve basic bearing modification designs are identified amd modeled. Four have single transverse convex curvature in their rollers while eight have rollers which have compound transverse curvature made up of a central cylindrical band surrounded by symmetric bands with slope and transverse curvature. The bearing designs are modeled for restoring torque per unit axial displacement, contact stress capacity, and contact area including dynamic loading, misalignment sensitivity and roller proportion. Design programs are available which size the single transverse curvature roller designs for a series of roller slopes and load separations and which design the compound roller bearings for a series of slopes and transverse radii of curvature. The compound rollers are proportioned to have equal contact stresses and minimum size. Design examples are also given.

  3. DW_BEAR

    Data.gov (United States)

    Department of Homeland Security — Subset of BEAR (Bi-Weekly Examination Analysis and Reporting) data used for financial audit remediation reporting within the Coast Guard Business Intelligence (CGBI)...

  4. Thermometric titrations of amines with nitrosyl perchlorate in acetonitrile solvent.

    Science.gov (United States)

    Gündüz, T; Kiliç, E; Cakirer, O

    1996-05-01

    Thirteen aliphatic and four aromatic amines, namely diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-butylamine, isopropylamine, di-isopropylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, aniline, N,N-dimethylaniline, 2-nitroaniline and 4-nitroaniline were titrated thermometrically with nitrosyl perchlorate in acetonitrile solvent. All the aliphatic amines gave very well-shaped thermometric titration curves. The calculated recovery values of the amines were very good. In comparison, the aromatic amines, aniline and N,N-dimethylaniline gave rather well-shaped titration curves, but the recovery values were fairly low. 2-Nitro- and 4-nitro anilines gave no thermometric response at all. The heats of reaction of the amines with nitrosyl perchlorate are rather high. However, the average heat of reaction of the aromatic amines is approximately two-thirds that of the average heat of the aliphatic amines. To support this method all the amines were also titrated potentiometrically and very similar results to those obtained with the thermometric method are seen. The nitrosyl ion is a Lewis acid, strong enough to titrate quantitatively aliphatic amines in acetonitrile solvent, but not strong enough to titrate aromatic amines at the required level in the same solvent.

  5. Synthesis and photochemical properties of a novel iron-sulfur-nitrosyl cluster derivatized with the pendant chromophore protoporphyrin IX.

    Science.gov (United States)

    Conrado, Christa L; Wecksler, Stephen; Egler, Christian; Magde, Douglas; Ford, Peter C

    2004-09-06

    The novel Roussin red-salt ester (PPIX-RSE) with a pendant porphyrin chromophore was prepared and investigated as a precursor for the photochemical generation of nitric oxide. PPIX-RSE has the general formula Fe(2)(NO)(4)[(mu-S,mu-S')P] (where (S,S')P is the bis(2-thiolatoethyl) diester of protoporphyrin IX. The photoexcitation of PPIX-RSE with 436- or 546-nm light in an aerated chloroform solution led to the photodecomposition of the cluster with the respective quantum yields (5.2 +/- 0.7) x 10(-4) and (2.5 +/- 0.5 x 10(-4)) and the concomitant release of NO. PPIX-RSE is a significantly more effective NO generator at longer wavelength excitation than are other Fe(2)(mu-SR)(2)(NO)(4) esters for which R is a simple alkyl group such as CH(3)CH(2)- because of the much higher absorptivity of the pendant PPIX chromophore at these wavelengths and a modestly higher quantum yield. Fluorescence intensity and lifetime data indicate that the photoexcited porphyrin of PPIX-RSE is largely quenched by the energy transfer to the Fe(2)S(2)(NO)(4) cluster's core. However, a small fraction of this emission is not quenched, and it is proposed that PPIX-RSE may exist in solution as two conformers.

  6. Rolling bearing analysis

    CERN Document Server

    Harris, Tedric A

    2001-01-01

    One of the most well-known experts in the field brings cutting-edge research to practitioners in the new edition of this important reference. Covers the improved mathematical calculations for rolling bearing endurance developed by the American Society of Mechanical Engineers and the Society of Lubrication and Tribology Engineers. Updated with new material on Condition-Based Maintenance, new testing methods, and new bearing materials.

  7. Gear bearing drive

    Science.gov (United States)

    Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor); Weinberg, Brian (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  8. Load responsive hydrodynamic bearing

    Science.gov (United States)

    Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

    2002-01-01

    A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

  9. Investigation on Al(III) and Zn(II) complexes containing a calix[4]arene bearing two 8-oxyquinoline pendant arms used as emitting materials for OLEDs

    International Nuclear Information System (INIS)

    Bagatin, Izilda A.; Legnani, Cristiano; Cremona, Marco

    2009-01-01

    A comparison between [Al·1] 3+ and [Zn·1] 2+ complexes (1 = 5,11,17,23-tetra-tert-butyl-25,27-bis[(quinoline-8-oxy)propyloxy]-26, 28-dihydroxy-calix[4]arene) has been made using electrochemical techniques and the experimental results obtained in the fabrication of organic light emitting devices (OLEDs). The electrochemically determined values of the ionization potential I p and electron affinity E a parameters for the [Al·1] 3+ (I p = 5.82eV, E a = 2.80eV) and [Zn·1] 2+ (I p = 5.67eV, E a = 2.32eV) evidenced that the [Al·1] 3+ complex is a better electron transporting layer with respect to the Zn complex one. The fabricated OLEDs based on these supramolecular complexes show a superior quality with the [Al·1] 3+ systems expected from the energy level diagrams

  10. Titanocene Dihalides and Ferrocenes Bearing a Pendant α-D-Xylofuranos-5-yl or α-D-Ribofuranos-5-yl Moiety. Synthesis, Characterization, and Cytotoxic Activity

    Czech Academy of Sciences Publication Activity Database

    Hodík, Tomáš; Lamač, Martin; Červenková Šťastná, Lucie; Karban, Jindřich; Koubková, L.; Hrstka, R.; Císařová, I.; Pinkas, Jiří

    2014-01-01

    Roč. 33, č. 8 (2014), s. 2059-2070 ISSN 0276-7333 R&D Projects: GA ČR(CZ) GAP207/12/2368 Institutional support: RVO:61388955 ; RVO:67985858 Keywords : BENZYL-SUBSTITUTED TITANOCENE S * POTENTIAL ANTIMALARIAL AGENTS * CYCLIC ALKYLAMMONIUM GROUPS Subject RIV: CF - Physical ; Theoretical Chemistry; CC - Organic Chemistry (UCHP-M) Impact factor: 4.126, year: 2014

  11. Unexpectedly Facile Rh(I) Catalyzed Polymerization of Ethynylbenzaldehyde Type Monomers: Synthesis of Polyacetylenes Bearing Reactive and Easy Transformable Pendant Carbaldehyde Groups

    Czech Academy of Sciences Publication Activity Database

    Sedláček, J.; Havelková, L.; Zedník, J.; Coufal, R.; Faukner, T.; Balcar, Hynek; Brus, Jiří

    2017-01-01

    Roč. 38, č. 8 (2017), č. článku 1600792. ISSN 1022-1336 R&D Projects: GA ČR(CZ) GA15-09637S Institutional support: RVO:61388955 ; RVO:61389013 Keywords : Ethynylbenzaldehydes * Inhibition of polymerization * Polyacetylenes Subject RIV: CF - Physical ; Theoretical Chemistry; CD - Macromolecular Chemistry (UMCH-V) OBOR OECD: Physical chemistry; Polymer science (UMCH-V) Impact factor: 4.265, year: 2016

  12. Uranium diphosphonates templated by interlayer organic amines

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Anna-Gay D., E-mail: nelsoa@umich.edu [Department of Civil Engineering and Geological Sciences, University of Notre Dame, IN 46556 (United States); Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Alekseev, Evgeny V. [Institute of Energy and Climate Research (IEK-6), Forschungszentrum Juelich Wilhelm-Johnen-Strasse, 52428 Juelich (Germany); Institut fuer Kristallographie, RWTH Aachen University, D-52066 Aachen (Germany); Albrecht-Schmitt, Thomas E. [Department of Civil Engineering and Geological Sciences, University of Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, IN 46556 (United States); Ewing, Rodney C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States)

    2013-02-15

    The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a variety of amines (2,2-dipyridyl, triethylenediamine, ethylenediamine, and 1,10-phenanthroline) at 200 Degree-Sign C results in the crystallization of a series of layered uranium diphosphonate compounds, [C{sub 10}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Ubip2), [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} (UDAB), [C{sub 2}H{sub 10}N{sub 2}]{sub 2}{l_brace}(UO{sub 2}){sub 2}(H{sub 2}O){sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{sub 2}{center_dot}0.5H{sub 2}O{r_brace} (Uethyl), and [C{sub 12}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Uphen). The crystal structures of the compounds are based on UO{sub 7} units linked by methylenediphosphonate molecules to form two-dimensional anionic sheets in Ubip2 and UDAB, and one-dimensional anionic chains in Uethyl and Uphen, which are charge balanced by protonated amine molecules. Interaction of the amine molecules with phosphonate oxygens and water molecules results in extensive hydrogen bonding in the interlayer. These amine molecules serve both as structure-directing agents and charge-balancing cations for the anionic uranium phosphonate sheets and chains in the formation of the different coordination geometries and topologies of each structure. Reported herein are the syntheses, structural and spectroscopic characterization of the synthesized compounds. - Graphical abstract: The Raman spectra of the synthesized compounds and an illustration of the stacking of the layers with the diprotonated triethylenediamine molecules in [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} UDAB. Solvent water molecules are removed for clarity. The corresponding Raman spectra for the complexes synthesized is also

  13. Amine promoted, metal enhanced degradation of Mirex under high temperature conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jallad, Karim N. [American University of Sharjah, Department of Chemistry, P.O. Box 26666, Sharjah (United Arab Emirates)]. E-mail: kjallad@runbox.com; Lynn, Bert C. [University of Kentucky, Department of Chemistry, Lexington, KY 40506-055 (United States); Alley, Earl G. [Mississippi State University, Department of Chemistry, MS State, MS 39762 (United States)

    2006-07-31

    In this study, zero-valent metal dehalogenation of mirex was conducted with amine solvents at high temperatures. Mirex was treated with excess amine in sealed glass tube reactors under nitrogen. The amines used were n-butyl amine (l), ethyl amine (l), dimethyl amine (g), diethyl amine (l), triethyl amine (l), trimethyl amine (g) and ammonia (g). The metals used were copper, zinc, magnesium, aluminum and calcium. The most suitable amine solvent and metal were selected by running a series of reactions with different amines and different zero-valent metals, in order to optimize the conditions under which complete degradation of mirex takes place. These dehalogenation reactions illustrated the role of zero-valent metals as reductants, whereas the amine solvents acted as proton donors. In this study, we report that mirex was completely degraded with diethyl amine (l) in the presence of copper at 100 deg. C and the hydrogenated products accounted for more than 94 of the degraded mirex.

  14. Protein covalent immobilization via its scarce thiol versus abundant amine groups: Effect on orientation, cell binding domain exposure and conformational lability.

    Science.gov (United States)

    Ba, O M; Hindie, M; Marmey, P; Gallet, O; Anselme, K; Ponche, A; Duncan, A C

    2015-10-01

    Quantity, orientation, conformation and covalent linkage of naturally cell adhesive proteins adsorbed or covalently linked to a surface, are known to influence the preservation of their subsequent long term cell adhesion properties and bioactivity. In the present work, we explore two different strategies for the covalent linking of plasma fibronectin (pFN) - used as a cell adhesive model protein, onto a polystyrene (PS) surface. One is aimed at tethering the protein to the surface in a semi-oriented fashion (via one of the 4 free thiol reactive groups on the protein) with a heterofunctional coupling agent (SSMPB method). The other aims to immobilize the protein in a more random fashion by reaction between the abundant pendant primary amine bearing amino acids of the pFN and activated carboxylic surface functions obtained after glutaric anhydride surface treatment (GA method). The overall goal will be to verify the hypothesis of a correlation between covalent immobilization of a model cell adhesive protein to a PS surface in a semi-oriented configuration (versus randomly oriented) with promotion of enhanced exposure of the protein's cell binding domain. This in turn would lead to enhanced cell adhesion. Ideally the goal is to elaborate substrates exhibiting a long term stable protein monolayer with preserved cell adhesive properties and bioactivity for biomaterial and/or cell adhesion commercial plate applications. However, the initial restrictive objective of this paper is to first quantitatively and qualitatively investigate the reversibly (merely adsorbed) versus covalently irreversibly bound protein to the surface after the immobilization procedure. Although immobilized surface amounts were similar (close to the monolayer range) for all immobilization approaches, covalent grafting showed improved retention and stronger "tethering" of the pFN protein to the surface (roughly 40%) after SDS rinsing compared to that for mere adsorption (0%) suggesting an added value

  15. Tandem catalytic allylic amination and [2,3]-Stevens rearrangement of tertiary amines.

    Science.gov (United States)

    Soheili, Arash; Tambar, Uttam K

    2011-08-24

    We have developed a catalytic allylic amination involving tertiary aminoesters and allylcarbonates, which is the first example of the use of tertiary amines as intermolecular nucleophiles in metal-catalyzed allylic substitution chemistry. This process is employed in a tandem ammonium ylide generation/[2,3]-rearrangement reaction, which formally represents a palladium-catalyzed Stevens rearrangement. Low catalyst loadings and mild reaction conditions are compatible with an unprecedented substrate scope for the ammonium ylide functionality, and products are generated in high yields and diastereoselectivities. Mechanistic studies suggested the reversible formation of an ammonium intermediate.

  16. Climate Drives Polar Bear Origins

    Science.gov (United States)

    In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

  17. Watchable Wildlife: The Black Bear

    Science.gov (United States)

    Lynn L. Rogers

    1992-01-01

    Black bears are the bears people most often encounter. Black bears live in forests over much of North America, unlike grizzlies that live only in Alaska, northern and western Canada, and the northern Rocky Mountains. This brochure presents the latest information on black bear life and how this species responds to an ever-increasing number of campers, hikers, and...

  18. New potential of the reductive alkylation of amines

    International Nuclear Information System (INIS)

    Gusak, K N; Ignatovich, Zh V; Koroleva, E V

    2015-01-01

    Available data on the reductive alkylation of amines with carbonyl compounds — a key method for the preparation of secondary and tertiary amines — are described systematically. The review provides information on the relevant reducing agents and catalysts and on the use of chiral catalysts in stereo- and enantiocontrolled reactions of amine synthesis. The effect of the reactant and catalyst structures on the reaction rates and chemo- and stereo(enantio)selectivity is considered. The bibliography includes 156 references

  19. Fluorescence quenching of Rhodamine B base by two amines

    Science.gov (United States)

    Bakkialakshmi, S.; Selvarani, P.; Chenthamarai, S.

    2013-03-01

    Fluorescence quenching of Rhodamine B base (RhB) in DMF solution has been studied at different concentrations of the amine Triethyl amine (TEA) and n-butyl amine (NBA) at room temperature. It has been observed that the fluorescence intensity of RhB decrease with increase in the concentration of the TEA and NBA. It has been observed that the quenching due to amines proceeds via dynamic quenching process. The rate constants for the quenching process have been calculated using Stern-Volmer equation. Time resolved fluorescence study and 1H NMR spectral study have also been carried out and discussed.

  20. Evaluation of amine inhibitors for suitability as crevice buffering agents

    International Nuclear Information System (INIS)

    Jayaweera, P.; Hettiarachchi, S.

    1994-03-01

    This report describes the results of a research effort to evaluate the suitability of some selected amines and amino acids as a crevice-buffering agents in pressurized water reactor (PWR) steam generators. The amines may be useful for buffering acid crevices, and the amino acids, because they contain both acidic and basic groups, may be useful for acidic and caustic crevices. Five commercially available amines and two amino acids were studied during this research. The study involved (1) the hydrolysis of these commercially available amines and amino acids, including measurement of their kinetics of decomposition, in simulated steam generator bulk water at 290 C, and (2) determination of their thermal stability in a simulated crevice environment. The study showed that, although the high-molecular-weight amines undergo hydrothermal decomposition, they have a better buffering capacity than their low-molecular-weight counterparts at 290 C. The amines provide effective crevice buffering by increasing the pH of the crevice solution by as much as 2.84 and to 4.24 units in the experimental setup used in this program. It was concluded that polyamines provide excellent buffering of the simulated crevice environment at 290 C and morpholine remains the best low-molecular-weight amine investigated. However, detailed volatility studies of the amines were not considered in this work. Such data would be needed before in-plant testing to ensure that the amines can concentrate in steam generator crevices to the levels assumed in this study

  1. Tribology of alternative bearings.

    Science.gov (United States)

    Fisher, John; Jin, Zhongmin; Tipper, Joanne; Stone, Martin; Ingham, Eileen

    2006-12-01

    The tribological performance and biological activity of the wear debris produced has been compared for highly cross-linked polyethylene, ceramic-on-ceramic, metal-on-metal, and modified metal bearings in a series of in vitro studies from a single laboratory. The functional lifetime demand of young and active patients is 10-fold greater than the estimated functional lifetime of traditional polyethylene. There is considerable interest in using larger diameter heads in these high demand patients. Highly cross-linked polyethylene show a four-fold reduction in functional biological activity. Ceramic-on-ceramic bearings have the lowest wear rates and least reactive wear debris. The functional biological activity is 20-fold lower than with highly cross-linked polyethylene. Hence, ceramic-on-ceramic bearings address the tribological lifetime demand of highly active patients. Metal-on-metal bearings have substantially lower wear rates than highly cross-linked polyethylene and wear decreases with head diameter. Bedding in wear is also lower with reduced radial clearance. Differential hardness ceramic-on-metal bearings and the application of ceramic-like coatings reduce metal wear and ion levels.

  2. Flotation of copper-bearing shale in solutions of inorganic salts and organic reagents

    Directory of Open Access Journals (Sweden)

    Ratajczak Tomasz

    2017-01-01

    Full Text Available Flotation data on copper-bearing shale in aqueous solutions of inorganic electrolytes (NaCl, Na2SO4, KPF6, NH4Cl and organic reagents (ethylamine, propylamine as frothers were presented and discussed. The relationships between shale flotation, surface tension of aqueous solution and foam height during bubbling with air in the flotation system were presented. It has been found that flotation of shale in the presence of inorganic salts the yield was directly proportional to the surface tension of the aqueous solution of salt and inversely proportional to the height of the foam. On the other hand, for organic reagents solutions (short chain amines, a reverse effect has been observed in relation to the inorganic compounds studied, that is the yield of copper-bearing shale flotation and the foam height were inversely proportional to the surface tension of the amine solution.

  3. Partial tooth gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  4. Poly(Amido Amine)s containing agmatine and butanol side chains as efficient gene carriers

    NARCIS (Netherlands)

    Won, Young-Wook; Ankone, Martinus J.K.; Engbersen, Johannes F.J.; Feijen, Jan; Kim, S.W.

    2016-01-01

    A new type of bioreducible poly(amido amine) copolymer is synthesized by the Michael addition polymerization of cystamine bisacrylamide (CBA) with 4-aminobutylguanidine (agmatine, AGM) and 4-aminobutanol (ABOL). Since the positively charged guanidinium groups of AGM and the hydroxybutyl groups of

  5. Amine reactivity with charged sulfuric acid clusters

    Directory of Open Access Journals (Sweden)

    B. R. Bzdek

    2011-08-01

    Full Text Available The distribution of charged species produced by electrospray of an ammonium sulfate solution in both positive and negative polarities is examined using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS. Positively-charged ammonium bisulfate cluster composition differs significantly from negatively-charged cluster composition. For positively-charged clusters all sulfuric acid is neutralized to bisulfate, whereas for negatively-charged clusters the degree of sulfuric acid neutralization is cluster size-dependent. With increasing cluster size (and, therefore, a decreasing role of charge, both positively- and negatively-charged cluster compositions converge toward ammonium bisulfate. The reactivity of negatively-charged sulfuric acid-ammonia clusters with dimethylamine and ammonia is also investigated by FTICR-MS. Two series of negatively-charged clusters are investigated: [(HSO4(H2SO4x] and [(NH4x(HSO4x+1(H2SO43]. Dimethylamine substitution for ammonia in [(NH4 x(HSO4 x+1(H2SO43] clusters is nearly collision-limited, and subsequent addition of dimethylamine to neutralize H2SO4 to bisulfate is within one order of magnitude of the substitution rate. Dimethylamine addition to [(HSO4 (H2SO4 x] clusters is either not observed or very slow. The results of this study indicate that amine chemistry will be evident and important only in large ambient negative ions (>m/z 400, whereas amine chemistry may be evident in small ambient positive ions. Addition of ammonia to unneutralized clusters occurs at a rate that is ~2–3 orders of magnitude slower than incorporation of dimethylamine either by substitution or addition

  6. Interaction of biogenic amines with ethanol.

    Science.gov (United States)

    Smith, A A

    1975-01-01

    Ethanol through its primary catabolite, acetaldehyde, competitively inhibits oxidation of aldehyde dehydrogenase substrates. As a consequence biogenic amines form increased quantities of alcohols rather than the corresponding acids. During this biotransformation, condensation reactions between deaminated and intact amines may occur which can yield tetrahydropapaverolines. These compounds are closely related to precursors of opioids which is cause to link ethanol abuse to morphine addiction. There is, however, no pharmacological or clinical evidence suggesting similarities between ethanol dependence or opiod addiction. Acetaldehyde plays an additional role in alkaloidal formation in vitro. Biogenic amines may react with acetaldehyde to form isoquinoline or carboline compounds. Some of these substances have significant pharmacological activity. Furthermore, they may enter neural stores and displace the natural neurotransmitter. Thus, they can act as false neurotransmitters. Some investigators believe that chronic ethanol ingestion leads to significant formation of such aberrant compounds which may then upset autonomic nervous system balance. This disturbance may explain the abnormal sympathetic activity seen in withdrawal. While these ideas about the etiology of alcohol abuse have a definite appeal, they are naturally based on in vitro preliminary work. Much study of the quantitative pharmacology of these compounds in animals is required before judgement can be made as to the merits of the proposed hypotheses. In the meantime, pharmacological studies on the ability of ethanol to depress respiration in the mouse has revealed that unlike opioids or barbituates, respiratory depression induced by ethanol requires the presence in brain of serotonin. This neurotransmitter also mediates the respiratory effects of several other alcohols but curiously, not chloral hydrate, yet this compound is purported to alter biogenic amine metabolism much like ethanol. Thus, the response

  7. Controlling Nitrosamines, Nitramines, and Amines in Amine-Based CO₂ Capture Systems with Continuous Ultraviolet and Ozone Treatment of Washwater.

    Science.gov (United States)

    Dai, Ning; Mitch, William A

    2015-07-21

    Formation of nitrosamines and nitramines from reactions between flue gas NOx and the amines used in CO2 capture units has arisen as a significant concern. Washwater scrubbers can capture nitrosamines and nitramines. They can also capture amines, preventing formation of nitrosamines and nitramines downwind by amine reactions with ambient NOx. The continuous application of UV alone, or a combination of UV and ozone to the return line of a washwater treatment unit was evaluated to control the accumulation of nitrosamines, nitramines and amines in a laboratory-scale washwater unit. With model secondary amine solvents ranging from nonvolatile diethanolamine to volatile morpholine, application of 272-537 mJ/cm(2) UV incident fluence alone reduced the accumulation of nitrosamines and nitramines by approximately an order of magnitude. Modeling indicated that the gains achieved by UV treatment should increase over time, because UV treatment converts the time dependence of nitrosamine accumulation from a quadratic to a linear function. Ozone (21 mg/L) maintained low steady-state concentrations of amines in the washwater. While modeling indicated that more than 80% of nitrosamine accumulation in the washwater was associated with reaction of washwater amines with residual NOx, a reduction in nitrosamine accumulation rates due to ozone oxidation of amines was not fully realized because the ozonation products of amines reduced nitrosamine photolysis rates by competing for photons.

  8. Synthesis and characterization of novel polyamide-ethers based on bis-imidazole containing bulky aryl pendant groups

    Directory of Open Access Journals (Sweden)

    Seyed Mahdi Saadati

    2013-01-01

    Full Text Available A series of novel polyamide-ethers (PAEs based on bis-imidazole containing bulky aryl pendant groups was prepared by direct polycondensation of a diamine, 4-(1-(4-(4-(2-(4-aminophenyl-4,5-diphenyl-1H-imidazol-1-ylphenoxyphenyl-4,5-diphenyl-1H-imidazol-2-ylbenzenamine (DABI, and various dicarboxylic acids. All the resulting polyamide-ethers were amorphous with inherent viscosities ranged from 0.52 to 0.61 dL/g and were readily soluble in many organic solvents which could be solution-cast into transparent and tough films. The glass transition temperatures (Tg of these polymers were affected considerably by their chemical structure and ranged from 230 to 310 ºC. They had useful levels of thermal stability associated with relatively high temperatures of 10% weight loss (T10 in the range of 329-399 ºC in air atmosphere.

  9. Consommation de caféine pendant la grossesse : retentissements maternels, foetaux, néonatals et infantiles

    OpenAIRE

    ALTIERI, Marie

    2015-01-01

    Introduction : La caféine, essentiellement présente dans le café, le thé, les boissons énergisantes, le cola, le cacao et certains médicaments, est la substance psychoactive la plus consommée pendant la grossesse. Elle traverse la barrière placentaire et présente une élimination ralentie chez la femme enceinte, le foetus et le nourrisson. Les études animales ont mis en évidence sa tératogénicité et sa toxicité pour la gestation et la santé des progénitures. Qu’en est-il du déroulement de la g...

  10. Trace Amines and the Trace Amine-Associated Receptor 1: Pharmacology, Neurochemistry and Clinical Implications

    Directory of Open Access Journals (Sweden)

    Yue ePei

    2016-04-01

    Full Text Available Biogenic amines are a collection of endogenous molecules that play pivotal roles as neurotransmitters and hormones. In addition to the classical biogenic amines resulting from decarboxylation of aromatic acids, including dopamine (DA, norepinephrine, epinephrine, serotonin (5-HT and histamine, other biogenic amines, present at much lower concentrations in the central nervous system (CNS, and hence referred to as trace amines (TAs, are now recognized to play significant neurophysiological and behavioural functions. At the turn of the century, the discovery of the trace amine-associated receptor 1 (TAAR1, a phylogenetically conserved G protein-coupled receptor that is responsive to both TAs, such as β-phenylethylamine, octopamine and tyramine, and structurally-related amphetamines, unveiled mechanisms of action for TAs other than interference with aminergic pathways, laying the foundations for deciphering the functional significance of TAs and its mammalian CNS receptor, TAAR1. Although its molecular interactions and downstream targets have not been fully elucidated, TAAR1 activation triggers accumulation of intracellular cAMP, modulates PKA and PKC signalling and interferes with the β-arrestin2-dependent pathway via G protein-independent mechanisms. TAAR1 is uniquely positioned to exert direct control over DA and 5-HT neuronal firing and release, which has profound implications for understanding the pathophysiology of, and therefore designing more efficacious therapeutic interventions for, a range of neuropsychiatric disorders that involve aminergic dysregulation, including Parkinson’s disease, schizophrenia, mood disorders and addiction. Indeed, the recent development of novel pharmacological tools targeting TAAR1 has uncovered the remarkable potential of TAAR1-based medications as new generation pharmacotherapies in neuropsychiatry. This review summarizes recent developments in the study of TAs and TAAR1, their intricate neurochemistry and

  11. Bifunctional (cyclopentadienone)iron-tricarbonyl complexes: Synthesis, computational studies and application in reductive amination

    KAUST Repository

    Moulin, Solenne; Dentel, Hé lè ne; Pagnoux-Ozherelyeva, Anastassiya; Gaillard, Sylvain; Poater, Albert; Cavallo, Luigi; Lohier, Jean Franç ois; Renaud, Jean Luc

    2013-01-01

    . Festival of amination: Two series of modified Knölker's complexes were synthesised and applied in the reductive amination of various carbonyl derivatives with primary or secondary amines (see scheme, TIPS = triisopropylsilyl). For a mechanistic insight

  12. New photoresponsive (meth)acrylate (co)polymers containing azobenzene pendant sidegroups with carboxylic and dimethylamino substituents .2. Synthesis and characterization of polymers and copolymers

    NARCIS (Netherlands)

    Haitjema, HJ; Buruma, R; VanEkenstein, GORA; Tan, YY; Challa, G

    1996-01-01

    The title (co)polymers, used for our investigations on their photoresponsive behaviour were obtained by free radical (co)polymerization. The monomer was either an acrylate or a methacrylate to which an azobenzene group, modified with a para-placed dimethylamino or a carboxylic pendant group, was

  13. Erratum to : Modeling of complex interfaces for pendant drop experiments (Rheologica Acta, , 55, 10, (801-822), 10.1007/s00397-016-0956-1)

    NARCIS (Netherlands)

    Balemans, C.; Hulsen, M.A.; Tervoort, T.A.; Anderson, P.D.

    2017-01-01

    The original version of this article unfortunately contained mistakes. Theo A. Tervoort was not listed among the authors. The correct information is given above. In Balemans et al. (2016), an axisymmetric finite element model is presented to study the behaviour of complex interfaces in pendant drop

  14. Thermodynamics of organic mixtures containing amines

    International Nuclear Information System (INIS)

    Gonzalez, Juan Antonio; Mozo, Ismael; Fuente, Isaias Garcia de la; Cobos, Jose Carlos

    2006-01-01

    Binary mixtures containing pyridine (PY), or 2-methylpyridine (2MPY) or 3-methylpyridine (3MPY) or 4-methylpyridine (4MPY) and an organic solvent as benzene, toluene, alkane, or 1-alkanol are investigated in the framework of DISQUAC. The corresponding interaction parameters are reported. The model describes accurately a whole set of thermodynamic properties: vapor-liquid equilibria (VLE), liquid-liquid equilibria (LLE), solid-liquid equilibria (SLE), molar excess Gibbs energies (G E ), molar excess enthalpies (H E ), molar excess heat capacities at constant pressure (C P E ) and the concentration-concentration structure factor (S CC (0)). It is remarkable that DISQUAC correctly predicts the W-shaped curve of the C P E of the pyridine + n-hexadecane system. The model can be applied successfully to mixtures with strong positive or negative deviations from the Raoult's law. DISQUAC improves the theoretical results from UNIFAC (Dortmund version). The replacement of pyridine by a methylpyridine leads to a weakening of the amine-amine interactions, ascribed to the steric effect caused by the methyl group attached to the aromatic ring. This explains that for a given solvent (alkane, 1-alkanol) H E (pyridine)>H E (methylpyridine)

  15. Reducing tube bundle deposition with alternative amines

    International Nuclear Information System (INIS)

    Turner, C.W.; Klimas, S.J.; Frattini, P.L.

    1998-01-01

    Particle deposition rates have been measured in a high-temperature loop for magnetite and hematite depositing onto Inconel-600 under flow-boiling conditions with pH controlled using one of the following amines: morpholine, ammonia, ethanolamine, or dimethylamine. Hematite particles deposited at rates an order of magnitude greater than those measured for magnetite, although the hematite deposition rate dropped when the loop was operated under reducing conditions. The magnetite deposition rate was influenced by the amine used to control the pH, with the relative rate decreasing in the following series: morpholine (1) : ethanolamine (0.72) ammonia (0.51) : dimethylamine (0.25). These trends in deposition rate are discussed in terms of the surface chemistry of the corrosion products. Deposition rates for both magnetite and hematite increased significantly once the mixture quality exceeded about 0.3, which may be related to a change in the heat transfer mechanism from nucleate boiling to two-phase forced convection through a thin film. (author)

  16. Reducing tube bundle deposition using alternative amines

    International Nuclear Information System (INIS)

    Turner, C.W.; Klimas, S.J.; Frattini, P.L.

    1999-07-01

    Particle deposition rates were measured in a high-temperature loop for magnetite and hematite depositing onto Inconel-600 under flow-boiling conditions with pH controlled, using one of the following amines: morpholine, ammonia, ethanolamine, or dimethylamine. Hematite particles deposited at rates 10 times greater than those measured for magnetite although the hematite deposition rate dropped when the loop was operated under reducing conditions. The magnetite deposition rate was influenced by the amine used to control the pH, with the relative rate decreasing in the following series: morpholine (1) : ethanolamine (0.72) : ammonia (0.51) dimethylamine (0.25). These trends in deposition rate are discussed in terms of the surface chemistry of the corrosion products. Deposition rates for both magnetite and hematite increased significantly once the mixture quality exceeded about 0.3, which may be related to a change in the heat-transfer mechanism from nucleate boiling to 2-phase forced-convection through a thin film. (author)

  17. Magnetically leviated superconducting bearing

    Science.gov (United States)

    Weinberger, Bernard R.; Lynds, Jr., Lahmer

    1993-01-01

    A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

  18. Conditions allowing the formation of biogenic amines in cheese

    NARCIS (Netherlands)

    Joosten, H.M.L.J.

    1988-01-01

    A study was undertaken to reveal the conditions that allow the formation of biogenic amines in cheese.

    The starters most commonly used in the Dutch cheese industry do not have decarboxylative properties. Only if the milk or curd is contaminated with non-starter bacteria, amine

  19. Amine-selective bioconjugation using arene diazonium salts.

    Science.gov (United States)

    Diethelm, Stefan; Schafroth, Michael A; Carreira, Erick M

    2014-08-01

    A novel bioconjugation strategy is presented that relies on the coupling of diazonium terephthalates with amines in proteins. The diazonium captures the amine while the vicinal ester locks it through cyclization, ensuring no reversibility. The reaction is highly efficient and proceeds under mild conditions and short reaction times. Densely functionalized, complex natural products were directly coupled to proteins using low concentrations of coupling partners.

  20. Effects of dietary amines on the gut and its vasculature.

    Science.gov (United States)

    Broadley, Kenneth J; Akhtar Anwar, M; Herbert, Amy A; Fehler, Martina; Jones, Elen M; Davies, Wyn E; Kidd, Emma J; Ford, William R

    2009-06-01

    Trace amines, including tyramine and beta-phenylethylamine (beta-PEA), are constituents of many foods including chocolate, cheeses and wines and are generated by so-called 'friendly' bacteria such as Lactobacillus, Lactococcus and Enterococcus species, which are found in probiotics. We therefore examined whether these dietary amines could exert pharmacological effects on the gut and its vasculature. In the present study we examined the effects of tyramine and beta-PEA on the contractile activity of guinea-pig and rat ileum and upon the isolated mesenteric vasculature and other blood vessels. Traditionally, these amines are regarded as sympathomimetic amines, exerting effects through the release of noradrenaline from sympathetic nerve endings, which should relax the gut. A secondary aim was therefore to confirm this mechanism of action. However, contractile effects were observed in the gut and these were independent of noradrenaline, acetylcholine, histamine and serotonin receptors. They were therefore probably due to the recently described trace amine-associated receptors. These amines relaxed the mesenteric vasculature. In contrast, the aorta and coronary arteries were constricted, a response that was also independent of a sympathomimetic action. From these results, we propose that after ingestion, trace amines could stimulate the gut and improve intestinal blood flow. Restriction of blood flow elsewhere diverts blood to the gut to aid digestion. Thus, trace amines in the diet may promote the digestive process through stimulation of the gut and improved gastrointestinal circulation.

  1. Mesoporous amine-bridged polysilsesquioxane for CO2 capture

    KAUST Repository

    Qi, Genggeng; Fu, Liling; Duan, Xiaonan; Choi, Brian Hyun; Abraham, Michael; Giannelis, Emmanuel P.

    2011-01-01

    A novel class of amine-supported sorbents based on amine-bridged mesoporous polysilsesquioxane was developed via a simple one-pot sol-gel process. The new sorbent allows the incorporation of a large amount of active groups without sacrificing

  2. Astramol polypropyleneimine dendrimers as Norrish Type II amine synergists

    NARCIS (Netherlands)

    Jansen, J.F.G.A.; Dias, A.A.; Hartwig, H.; Janssen, R.A.J.

    2000-01-01

    UV-curable coatings for various applications . In most of these applications they serve a dual role ie as initiator and as oxygen scavenger. Dimethylethanolamine is one of the more frequently employed aliphatic amines. However, this amine is a highly volatile . AstramolTM polypropyleneimine

  3. Biogenic amines degradation by microorganisms isolated from cheese

    Directory of Open Access Journals (Sweden)

    Irena Butor

    2017-01-01

    Full Text Available The aim of this study was the isolation and characterization of microorganisms able to degrade biogenic amines and their identification. Individual microorganisms were obtained by isolation from commercially available foodstuffs and food produced in the technological laboratories of Faculty of Technology, Tomas Bata University in Zlín and subsequently identified by MALDI-TOF MS. The results of MALDI-TOF MS identification were verified by 16S rRNA sequenation. In this work was studied the ability of 5 bacterial strains positive to biogenic amines degradation isolated from dairy products to decrease biogenic amines content in vitro and quantified reduction in the concentration of biogenic amines tryptamine, β-phenylethylamine, putrescine, cadaverine, histamine and tyramine. The level of degradation (decrease of biogenic amines was determined on the base of the ability to grow in media with biogenic amines as the sole source carbon and nitrogen. The isolated strains with the ability of degradation of one or more biogenic amines were cultured in medium supplemented with relevant biogenic amines, the media derivatized with dansyl chloride and these amines separated by HPLC at a wavelength of 254 nm. From five tested strains identified as Bacillus subtilis, Bacillus pumilus, Enterobacter cloacae, Rhizobium radiobacter and Acinetobacter pitii, isolated from gouda type cheese, the greatest ability of degradation was observed in Bacillus subtilis, which was capable to degrade almost all amount of histamine, cadaverine and putrescine. Other four strains showed a lower rate of degradation than Bacillus subtilis, but the ability to degrade biogenic amines with these microorganisms was still significant.

  4. A versatile family of degradable non-viral gene carriers based on hyperbranched poly(ester amine)s

    NARCIS (Netherlands)

    Zhong, Zhiyuan; Song, Y.; Engbersen, Johannes F.J.; Lok, Martin C.; Hennink, Wim E.; Feijen, Jan

    2005-01-01

    A variety of degradable hyperbranched poly(ester amine)s containing primary, secondary and tertiary amino groups, were synthesized and evaluated as non-viral gene carriers. The polymers were obtained in high yields through a Michael-type conjugate addition of diacrylate monomers with trifunctional

  5. Dual C-H functionalization of N-aryl amines: synthesis of polycyclic amines via an oxidative Povarov approach.

    Science.gov (United States)

    Min, Chang; Sanchawala, Abbas; Seidel, Daniel

    2014-05-16

    Iminium ions generated in situ via copper(I) bromide catalyzed oxidation of N-aryl amines readily undergo [4 + 2] cycloadditions with a range of dienophiles. This method involves the functionalization of both a C(sp(3))-H and a C(sp(2))-H bond and enables the rapid construction of polycyclic amines under relatively mild conditions.

  6. Actuators for Active Magnetic Bearings

    Directory of Open Access Journals (Sweden)

    Eric H. Maslen

    2017-10-01

    Full Text Available The literature of active magnetic bearing (AMB technology dates back to at least 1937 when the earliest work that clearly describes an active magnetic bearing system was published by Jesse Beams [...

  7. Production of Primary Amines by Reductive Amination of Biomass-Derived Aldehydes/Ketones.

    Science.gov (United States)

    Liang, Guanfeng; Wang, Aiqin; Li, Lin; Xu, Gang; Yan, Ning; Zhang, Tao

    2017-03-06

    Transformation of biomass into valuable nitrogen-containing compounds is highly desired, yet limited success has been achieved. Here we report an efficient catalyst system, partially reduced Ru/ZrO 2 , which could catalyze the reductive amination of a variety of biomass-derived aldehydes/ketones in aqueous ammonia. With this approach, a spectrum of renewable primary amines was produced in good to excellent yields. Moreover, we have demonstrated a two-step approach for production of ethanolamine, a large-market nitrogen-containing chemical, from lignocellulose in an overall yield of 10 %. Extensive characterizations showed that Ru/ZrO 2 -containing multivalence Ru association species worked as a bifunctional catalyst, with RuO 2 as acidic promoter to facilitate the activation of carbonyl groups and Ru as active sites for the subsequent imine hydrogenation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Delayed child-bearing.

    Science.gov (United States)

    Johnson, Jo-Ann; Tough, Suzanne

    2012-01-01

    To provide an overview of delayed child-bearing and to describe the implications for women and health care providers. Delayed child-bearing, which has increased greatly in recent decades, is associated with an increased risk of infertility, pregnancy complications, and adverse pregnancy outcome. This guideline provides information that will optimize the counselling and care of Canadian women with respect to their reproductive choices. Maternal age is the most important determinant of fertility, and obstetric and perinatal risks increase with maternal age. Many women are unaware of the success rates or limitations of assisted reproductive technology and of the increased medical risks of delayed child-bearing, including multiple births, preterm delivery, stillbirth, and Caesarean section. This guideline provides a framework to address these issues. Studies published between 2000 and August 2010 were retrieved through searches of PubMed and the Cochrane Library using appropriate key words (delayed child-bearing, deferred pregnancy, maternal age, assisted reproductive technology, infertility, and multiple births) and MeSH terms (maternal age, reproductive behaviour, fertility). The Internet was also searched using similar key words, and national and international medical specialty societies were searched for clinical practice guidelines and position statements. Data were extracted based on the aims, sample, authors, year, and results. The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). The Society of Obstetricians and Gynaecologists of Canada. RECOMMENDATIONS 1. Women who delay child-bearing are at increased risk of infertility. Prospective parents, especially women, should know that their fecundity and fertility begin to decline significantly after 32 years of age. Prospective parents should know that assisted reproductive technologies cannot guarantee a live birth or completely

  9. Government Risk-Bearing

    CERN Document Server

    1993-01-01

    The u.s. government bulks large in the nation's financial markets. The huge volume of government-issued and -sponsored debt affects the pricing and volume ofprivate debt and, consequently, resource allocation between competing alternatives. What is often not fully appreciated is the substantial influence the federal government wields overresource allocation through its provisionofcreditandrisk-bearing services to the private economy. Because peopleand firms generally seekto avoid risk, atsomeprice they are willing to pay another party to assume the risk they would otherwise face. Insurance companies are a class of private-sector firms one commonly thinks of as providing these services. As the federal government has expanded its presence in the U.S. economy during this century, it has increasingly developed programs aimed at bearing risks that the private sector either would not take on at any price, or would take on but atapricethoughtto besogreatthatmostpotentialbeneficiarieswouldnotpurchase the coverage. To...

  10. Passive magnetic bearing system

    Science.gov (United States)

    Post, Richard F.

    2014-09-02

    An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.

  11. Stacked magnet superconducting bearing

    International Nuclear Information System (INIS)

    Rigney, T.K. II; Saville, M.P.

    1993-01-01

    A superconducting bearing is described, comprising: a plurality of permanent magnets magnetized end-to-end and stacked side-by-side in alternating polarity, such that flux lines flow between ends of adjacent magnets; isolating means, disposed between said adjacent magnets, for reducing flux leakage between opposing sides of said adjacent magnets; and a member made of superconducting material having at least one surface in communication with said flux lines

  12. Radium bearing waste disposal

    International Nuclear Information System (INIS)

    Tope, W.G.; Nixon, D.A.; Smith, M.L.; Stone, T.J.; Vogel, R.A.; Schofield, W.D.

    1995-01-01

    Fernald radium bearing ore residue waste, stored within Silos 1 and 2 (K-65) and Silo 3, will be vitrified for disposal at the Nevada Test Site (NTS). A comprehensive, parametric evaluation of waste form, packaging, and transportation alternatives was completed to identify the most cost-effective approach. The impacts of waste loading, waste form, regulatory requirements, NTS waste acceptance criteria, as-low-as-reasonably-achievable principles, and material handling costs were factored into the recommended approach

  13. Electrochemical characterization of aminated acrylic conducting polymer

    International Nuclear Information System (INIS)

    Rashid, Norma Mohammad; Heng, Lee Yook; Ling, Tan Ling

    2015-01-01

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study

  14. Electrochemical characterization of aminated acrylic conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Norma Mohammad [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Heng, Lee Yook [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ling, Tan Ling [Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  15. Magnetic translator bearings

    Science.gov (United States)

    Hockney, Richard L. (Inventor); Downer, James R. (Inventor); Eisenhaure, David B. (Inventor); Hawkey, Timothy J. (Inventor); Johnson, Bruce G. (Inventor)

    1990-01-01

    A magnetic bearing system for enabling translational motion includes a carriage and a shaft for movably supporting the carriage; a first magnetic bearing fixed to one of the carriage and shaft and slidably received in a first channel of the other of the carriage and shaft. The first channel is generally U shaped with two side walls and a back wall. The magnetic bearing includes a pair of spaced magnetic pole pieces, each pole piece having a pair of electromagnetic coils mounted on poles on opposite ends of the pole piece proximate the side walls, and a third electromagnetic coil mounted on a pole of the pole piece proximate the backwall; a motion sensor for sensing translational motion along two axes and rotationally about three axes of the carriage and shaft relative to each other; and a correction circuit responsive to the sensor for generating a correction signal to drive the coils to compensate for any misalignment sensed between the carriage and the shaft.

  16. Poly(Amido Amine)s Containing Agmatine and Butanol Side Chains as Efficient Gene Carriers.

    Science.gov (United States)

    Won, Young-Wook; Ankoné, Marc; Engbersen, Johan F J; Feijen, Jan; Kim, Sung Wan

    2016-04-01

    A new type of bioreducible poly(amido amine) copolymer is synthesized by the Michael addition polymerization of cystamine bisacrylamide (CBA) with 4-aminobutylguanidine (agmatine, AGM) and 4-aminobutanol (ABOL). Since the positively charged guanidinium groups of AGM and the hydroxybutyl groups of ABOL in the side chains have shown to improve the overall transfection efficiency of poly(amido amine)s, it is hypothesized that poly(CBA-ABOL/AGM) synthesized at the optimal ratio of both components would result in high transfection efficiency and minimal toxicity. In this study, a series of the poly(CBA-ABOL/AGM) copolymers is synthesized as gene carriers. The polymers are characterized and luciferase transfection efficiencies of the polymers in various cell lines are investigated to select the ideal ratio between AGM and ABOL. The poly(CBA-ABOL/AGM) containing 80% AGM and 20% ABOL has shown the best transfection efficiency with the lowest cytotoxicity, indicating that this polymer is very promising as a potent and nontoxic gene carrier. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Surface modification of GC and HOPG with diazonium, amine, azide, and olefin derivatives.

    Science.gov (United States)

    Tanaka, Mutsuo; Sawaguchi, Takahiro; Sato, Yukari; Yoshioka, Kyoko; Niwa, Osamu

    2011-01-04

    Surface modification of glassy carbon (GC) and highly oriented pyrolytic graphite (HOPG) was carried out with diazonium, amine, azide, and olefin derivatives bearing ferrocene as an electroactive moiety. Features of the modified surfaces were evaluated by surface concentrations of immobilized molecule, blocking effect of the modified surface against redox reaction, and surface observation using cyclic voltammetry and electrochemical scanning tunneling microscope (EC-STM). The measurement of surface concentrations of immobilized molecule revealed the following three aspects: (i) Diazonium and olefin derivatives could modify substrates with the dense-monolayer concentration. (ii) The surface concentration of immobilized amine derivative did not reach to the dense-monolayer concentration reflecting their low reactivity. (iii) The surface modification with the dense-monolayer concentration was also possible with azide derivative, but the modified surface contained some oligomers produced by the photoreaction of azides. Besides, the blocking effect against redox reaction was observed for GC modified with diazonium derivative and for HOPG modified with diazonium and azide derivatives, suggesting fabrication of a densely modified surface. Finally, the surface observation for HOPG modified with diazonium derivative by EC-STM showed a typical monolayer structure, in which the ferrocene moieties were packed densely at random. On the basis of those results, it was demonstrated that surface modification of carbon substrates with diazonium could afford a dense monolayer similar to the self-assembled monolayer (SAM) formation.

  18. Solvent-free functionalization of carbon nanotube buckypaper with amines

    International Nuclear Information System (INIS)

    Basiuk, Elena V.; Ramírez-Calera, Itzel J.; Meza-Laguna, Victor; Abarca-Morales, Edgar; Pérez-Rey, Luis A.; Re, Marilena; Prete, Paola; Lovergine, Nico

    2015-01-01

    Graphical abstract: - Abstract: We demonstrate the possibility of fast and efficient solvent-free functionalization of buckypaper (BP) mats prefabricated from oxidized multiwalled carbon nanotubes (MWCNTs-ox), by using three representative amines of different structure: one monofunctional aliphatic amine, octadecylamine (ODA), one monofunctional aromatic amine, 1-aminopyrene (AP), and one aromatic diamine, 1,5-diaminonaphthalene (DAN). The functionalization procedure, which relies on the formation of amide bonds with carboxylic groups of MWCNTs-ox, is performed at 150–180 °C under reduced pressure and takes about 4 h including auxiliary degassing. The amine-treated BP samples (BP-ODA, BP-AP and BP-DAN, respectively) were characterized by means of a variety of analytical techniques such as Fourier-transform infrared and Raman spectroscopy, thermogravimetric and differential thermal analysis, scanning and transmission electron microscopy, scanning helium ion microscopy, and atomic force microscopy. The highest amine content was found for BP-ODA, and the lowest one was observed for BP-DAN, with a possible contribution of non-covalently bonded amine molecules in all three cases. Despite of some differences in spectral and morphological characteristics for amine-functionalized BP samples, they have in common a dramatically increased stability in water as compared to pristine BP and, on the other hand, a relatively invariable electrical conductivity.

  19. Ozone Promotes Chloropicrin Formation by Oxidizing Amines to Nitro Compounds.

    Science.gov (United States)

    McCurry, Daniel L; Quay, Amanda N; Mitch, William A

    2016-02-02

    Chloropicrin formation has been associated with ozonation followed by chlorination, but the reaction pathway and precursors have been poorly characterized. Experiments with methylamine demonstrated that ozonation converts methylamine to nitromethane at ∼100% yield. Subsequent chlorination converts nitromethane to chloropicrin at ∼50% yield under the conditions evaluated. Similarly high yields from other primary amines were limited to those with functional groups on the β-carbon (e.g., the carboxylic acid in glycine) that facilitate carbon-carbon bond cleavage to release nitromethyl anion. Secondary amines featuring these reactive primary amines as functional groups (e.g., secondary N-methylamines) formed chloropicrin at high yields, likely by facile dealkylation to release the primary nitro compound. Chloropicrin yields from tertiary amines were low. Natural water experiments, including derivatization to transform primary and secondary amines to less reactive carbamate functional groups, indicated that primary and secondary amines were the dominant chloropicrin precursors during ozonation/chlorination. Ozonation followed by chlorination of the primary amine side chain of lysine demonstrated low yields (∼0.2%) of chloropicrin, but high yields (∼17%) of dichloronitrolysine, a halonitroalkane structural analogue to chloropicrin. However, chloropicrin yields increased and dichloronitrolysine yields decreased in the absence of hydroxyl radical scavengers, suggesting that future research should characterize the potential occurrence of such halonitroalkane analogues relative to natural radical scavenger (e.g., carbonate) concentrations.

  20. Monoanionic 99mTc-tricarbonyl-aminopolycarboxylate complexes with uncharged pendant groups: Radiosynthesis and evaluation as potential renal tubular tracers

    International Nuclear Information System (INIS)

    Lipowska, Malgorzata; Klenc, Jeffrey; Jarkas, Nashwa; Marzilli, Luigi G.; Taylor, Andrew T.

    2017-01-01

    Introduction: 99m Tc(CO) 3 -nitrilotriacetic acid, 99m Tc(CO) 3 (NTA), is a new renal tubular agent with pharmacokinetic properties comparable to those of 131 I-OIH but the clearance of 99m Tc(CO) 3 (NTA) and 131 I-OIH is still less than the clearance of PAH, the gold standard for the measurement of effective renal plasma flow. At physiological pH, dianionic 99m Tc(CO) 3 (NTA) has a mononegative inner metal-coordination sphere and a mononegative uncoordinated carboxyl group. To evaluate alternate synthetic approaches, we assessed the importance of an uncoordinated carboxyl group, long considered essential for tubular transport, by evaluating the pharmacokinetics of three analogs with the 99m Tc(CO) 3 (NTA) metal-coordination sphere but with uncharged pendant groups. Methods: 99m Tc(CO) 3 complexes with N-(2-acetamido)iminodiacetic acid (ADA), N-(2-hydroxyethyl)iminodiacetic acid (HDA) and N-(fluoroethyl)iminodiacetic acid (FEDA) were prepared using a tricarbonyl kit and isolated by HPLC. The pharmacokinetics were evaluated in Sprague–Dawley rats, with 131 I-OIH as an internal control; urine was analyzed for metabolites. Plasma protein binding and erythrocyte uptake were determined from the 10 min blood samples. Re(CO) 3 (FEDA), the analog of 99m Tc(CO) 3 (FEDA), was prepared and characterized. Results: 99m Tc(CO) 3 (ADA), 99m Tc(CO) 3 (HDA) and 99m Tc(CO) 3 (FEDA) were efficiently prepared as a single species with high radiochemical purities (>99%). These new monoanionic 99m Tc(CO) 3 tracers with uncharged dangling groups all showed rapid blood clearance and high specificity for renal excretion. Activity in the urine, as a percent of 131 I-OIH at 10 and 60 min, was 96% and 99% for ADA, 96% and 100% for HDA, and 100% and 99% for FEDA, respectively. Each new tracer was excreted unchanged in the urine. The Re(CO) 3 (FEDA) structure adds compelling evidence that such 99m Tc(CO) 3 (NTA) analogs have metal-coordination spheres identical to that of 99m Tc(CO) 3 (NTA

  1. Bearing for liquid metal pump

    International Nuclear Information System (INIS)

    Dickinson, R.J.; Pennell, W.E.; Wasko, J.

    1984-01-01

    A liquid metal pump bearing support comprises a series of tangentially oriented spokes that connect the bearing cylinder to the pump internals structure. The spokes may be arranged in a plurality of planes extending from the bearing cylinder to the pump internals with the spokes in one plane being arranged alternately with those in the next plane. The bearing support structure provides the pump with sufficient lateral support for the bearing structure together with the capability of accommodating differential thermal expansion without adversely affecting pump performance

  2. Amine functionalized nanodiamond promotes cellular adhesion, proliferation and neurite outgrowth

    International Nuclear Information System (INIS)

    Hopper, A P; Dugan, J M; Gill, A A; Haycock, J W; Claeyssens, F; Fox, O J L; May, P W

    2014-01-01

    In this study, we report the production of amine functionalized nanodiamond. The amine functionalized nanodiamond forms a conformal monolayer on a negatively charged surface produced via plasma polymerization of acrylic acid. Nanodiamond terminated surfaces were studied as substrates for neuronal cell culture. NG108-15 neuroblastoma-glyoma hybrid cells were successfully cultured upon amine functionalized nanodiamond coated surfaces for between 1 and 7 d. Additionally, primary dorsal root ganglion (DRG) neurons and Schwann cells isolated from Wistar rats were also successfully cultured over a period of 21 d illustrating the potential of the coating for applications in the treatment of peripheral nerve injury. (paper)

  3. BIOGENIC AMINES CONTENT IN SELECTED WINES DURING WINEMAKING

    Directory of Open Access Journals (Sweden)

    Radka Flasarová

    2012-02-01

    Full Text Available The aim of this study was to describe the development of selected biogenic amines (histamine; tyramine; phenylethylamine; putrescine; agmatine; and cadaverine during the winemaking in 10 selected species grown in Central Europe in 2008. The analysis was performed using ion-exchange chromatography by the sodium-citrate buffers with the post-column ninhydrin derivatization and photometric detection. A comparison of the content of biogenic amines in red and wine varieties showed that red wines have higher concentrations of biogenic amines.

  4. Bearing construction for refrigeration compresssor

    Science.gov (United States)

    Middleton, Marc G.; Nelson, Richard T.

    1988-01-01

    A hermetic refrigeration compressor has a cylinder block and a crankshaft rotatable about a vertical axis to reciprocate a piston in a cylinder on the cylinder block. A separate bearing housing is secured to the central portion of the cylinder block and extends vertically along the crankshaft, where it carries a pair of roller bearings to journal the crankshaft. The crankshaft has a radially extending flange which is journaled by a thrust-type roller bearing above the bearing housing to absorb the vertical forces on the crankshaft so that all three of the roller bearings are between the crankshaft and the bearing housing to maintain and control the close tolerances required by such bearings.

  5. 77 FR 70423 - Black Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC...

    Science.gov (United States)

    2012-11-26

    ... Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC; Notice of..., 2012, Black Bear Hydro Partners, LLC, sole licensee (transferor) and Black Bear Development Holdings, LLC and Black Bear SO, LLC (transferees) filed an application for the partial the transfer of licenses...

  6. Introgressive hybridization: brown bears as vectors for polar bear alleles.

    Science.gov (United States)

    Hailer, Frank

    2015-03-01

    The dynamics and consequences of introgression can inform about numerous evolutionary processes. Biologists have therefore long been interested in hybridization. One challenge, however, lies in the identification of nonadmixed genotypes that can serve as a baseline for accurate quantification of admixture. In this issue of Molecular Ecology, Cahill et al. (2015) analyse a genomic data set of 28 polar bears, eight brown bears and one American black bear. Polar bear alleles are found to be introgressed into brown bears not only near a previously identified admixture zone on the Alaskan Admiralty, Baranof and Chichagof (ABC) Islands, but also far into the North American mainland. Elegantly contrasting admixture levels at autosomal and X chromosomal markers, Cahill and colleagues infer that male-biased dispersal has spread these introgressed alleles away from the Late Pleistocene contact zone. Compared to a previous study on the ABC Island population in which an Alaskan brown bear served as a putatively admixture-free reference, Cahill et al. (2015) utilize a newly sequenced Swedish brown bear as admixture baseline. This approach reveals that brown bears have been impacted by introgression from polar bears to a larger extent (up to 8.8% of their genome), than previously known, including the bear that had previously served as admixture baseline. No evidence for introgression of brown bear into polar bear is found, which the authors argue could be a consequence of selection. Besides adding new exciting pieces to the puzzle of polar/brown bear evolutionary history, the study by Cahill and colleagues highlights that wildlife genomics is moving from analysing single genomes towards a landscape genomics approach. © 2015 John Wiley & Sons Ltd.

  7. Atmospheric chemistry and environmental impact of the use of amines in carbon capture and storage (CCS).

    Science.gov (United States)

    Nielsen, Claus J; Herrmann, Hartmut; Weller, Christian

    2012-10-07

    This critical review addresses the atmospheric gas phase and aqueous phase amine chemistry that is relevant to potential emissions from amine-based carbon capture and storage (CCS). The focus is on amine, nitrosamine and nitramine degradation, and nitrosamine and nitramine formation processes. A comparison between the relative importance of the various atmospheric sinks for amines, nitrosamines and nitramines is presented.

  8. Bioinspired organocatalytic aerobic C-H oxidation of amines with an ortho-quinone catalyst.

    Science.gov (United States)

    Qin, Yan; Zhang, Long; Lv, Jian; Luo, Sanzhong; Cheng, Jin-Pei

    2015-03-20

    A simple bioinspired ortho-quinone catalyst for the aerobic oxidative dehydrogenation of amines to imines is reported. Without any metal cocatalysts, the identified optimal ortho-quinone catalyst enables the oxidations of α-branched primary amines and cyclic secondary amines. Mechanistic studies have disclosed the origins of different performances of ortho-quinone vs para-quinone in biomimetic amine oxidations.

  9. Transmissive-to-black fast electrochromic switching from a long conjugated pendant group and a highly dispersed polymer/SWNT

    KAUST Repository

    Zhang, Qiang

    2018-01-03

    In this study, a novel conjugated polymer, denoted as ECPblack, is synthesized. ECPblack demonstrated a unique electrochromic behavior with an ultrahigh contrast ratio (over 80%) in most of the visible regions, boasting an ultrahigh integrated contrast ratio of 71.8% between 380 nm and 880 nm. The long conjugated pendant group (pyrene) in ECPblack enhances the absorption in the blue region in its second oxidized state and results in transmissive-to-black electrochromic switching between the neutral state and the oxidized state. The transmissive-to-black electrochromic switching polymer with an ultrahigh contrast ratio could be especially attractive for applications in electronic displays. In addition, when polytriarylamine/nanotube (SWNT/P2) dispersion is doped in ECPblack, the response time of its electrochemical and electrochromic behaviors is further reduced. The electrochromic switching and bleaching time of SWNT/P2/ECPblack decreased by 73% and 80%, respectively. The improvement is caused by the phase separation of the rigid SWNT and the flexible polymer, which generates a rough surface morphology and provides more pathways for faster diffusion of counterions (ClO4-). The polymer/SWNT doping technique provides a simple way to accelerate ion diffusion in anodically coloring materials.

  10. Difluorobenzothiadiazole based two-dimensional conjugated polymers with triphenylamine substituted moieties as pendants for bulk heterojunction solar cells

    Directory of Open Access Journals (Sweden)

    W. H. Lee

    2017-11-01

    Full Text Available Three donor/acceptor (D/A-type two-dimensional polythiophenes (PTs; PBTFA13, PBTFA12, PBTFA11 featuring difluorobenzothiadiazole (DFBT derivatives as the conjugated (acceptor units in the polymer backbone and tertbutyl–substituted triphenylamine (tTPA-containing moieties as (donor pendants have been synthesized and characterized. These PTs exhibited good thermal stabilities, broad absorption spectra, and narrow optical band gaps. The cutoff wavelength of the UV–Vis absorption band was red-shifted upon increasing the content of the DFBT units in the PTs. Bulk heterojunction solar cells having an active layer comprising blends of the PTs and fullerene derivatives [6,6] phenyl-C61/71-butyric acid methyl ester (PC61BM/PC71BM were fabricated; their photovoltaic performance was strongly dependent on the content of the DFBT derivative in the PT. Incorporating a suitable content of the DFBT derivative in the polymer backbone enhanced the solar absorption ability and conjugation length of the PTs. The photovoltaic properties of the PBTFA13-based solar cells were superior to those of the PBTFA11- and PBTFA12-based solar cells.

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

    Science.gov (United States)

    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.

    2014-01-01

    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

  12. Transmissive-to-black fast electrochromic switching from a long conjugated pendant group and a highly dispersed polymer/SWNT

    KAUST Repository

    Zhang, Qiang; Tsai, Chou-Yi; Abidin, Taufik; Jiang, Jyh-Chiang; Shie, Wan-Ru; Li, Lain-Jong; Liaw, Der-Jang

    2018-01-01

    In this study, a novel conjugated polymer, denoted as ECPblack, is synthesized. ECPblack demonstrated a unique electrochromic behavior with an ultrahigh contrast ratio (over 80%) in most of the visible regions, boasting an ultrahigh integrated contrast ratio of 71.8% between 380 nm and 880 nm. The long conjugated pendant group (pyrene) in ECPblack enhances the absorption in the blue region in its second oxidized state and results in transmissive-to-black electrochromic switching between the neutral state and the oxidized state. The transmissive-to-black electrochromic switching polymer with an ultrahigh contrast ratio could be especially attractive for applications in electronic displays. In addition, when polytriarylamine/nanotube (SWNT/P2) dispersion is doped in ECPblack, the response time of its electrochemical and electrochromic behaviors is further reduced. The electrochromic switching and bleaching time of SWNT/P2/ECPblack decreased by 73% and 80%, respectively. The improvement is caused by the phase separation of the rigid SWNT and the flexible polymer, which generates a rough surface morphology and provides more pathways for faster diffusion of counterions (ClO4-). The polymer/SWNT doping technique provides a simple way to accelerate ion diffusion in anodically coloring materials.

  13. Self lubricating fluid bearings

    International Nuclear Information System (INIS)

    Kapich, D.D.

    1980-01-01

    The invention concerns self lubricating fluid bearings, which are used in a shaft sealed system extending two regions. These regions contain fluids, which have to be isolated. A first seal is fluid tight for the first region between the carter shaft and the shaft. The second seal is fluid tight between the carter and the shaft, it communicates with the second region. The first fluid region is the environment surrounding the shaft carter. The second fluid region is a part of a nuclear reactor which contains the cooling fluid. The shaft is conceived to drive a reactor circulating and cooling fluid [fr

  14. Efficient acetylation of primary amines and amino acids in ...

    Indian Academy of Sciences (India)

    bDepartment of Clinical and Experimental Pharmacology, School of Tropical Medicine ... As a result ... methods of acetylation of amines are known using ace- ... vents we report here, environmentally benign, eco- ... It was filtered under suction,.

  15. Preparation and adsorption property of aminated cross linking ...

    Indian Academy of Sciences (India)

    Administrator

    city and blood compatible and biocompatible. The preliminary study on the ... der reduced pressure before being used. Polyvinyl .... above, the difference of the amount of amine groups ... varying of connecting arm in length. Bilirubin mole-.

  16. Two simple amine hydrochlorides from the soft coral Lobophytum strictum

    Digital Repository Service at National Institute of Oceanography (India)

    Parameswaran, P.S.; Naik; Das, B.; Kamat, S.Y.

    Two simple amine hydrochlorides, viz., 1-amino-1, 1-dimethyl-3-oxo-butane hydrochloride (1) (Diacetonamine) and 2, 2, 6, 6-tetramethylpiperidone hydrochloride (2) have been isolated from the fraction of the methanolic extract of the soft coral...

  17. Next Generation Life Support (NGLS): Rapid Cycle Amine Swing Bed

    Data.gov (United States)

    National Aeronautics and Space Administration — The Rapid Cycle Amine (RCA) swingbed has been identified as a technology with high potential to meet the stringent requirements for the next generation spacesuit's...

  18. Structure and activity of Aspergillus nidulans copper amine oxidase

    DEFF Research Database (Denmark)

    McGrath, Aaron P; Mithieux, Suzanne M; Collyer, Charles A

    2011-01-01

    Aspergillus nidulans amine oxidase (ANAO) has the unusual ability among the family of copper and trihydroxyphenylalanine quinone-containing amine oxidases of being able to oxidize the amine side chains of lysine residues in large peptides and proteins. We show here that in common with the related...... enzyme from the yeast Pichia pastoris, ANAO can promote the cross-linking of tropoelastin and oxidize the lysine residues in α-casein proteins and tropoelastin. The crystal structure of ANAO, the first for a fungal enzyme in this family, has been determined to a resolution of 2.4 Å. The enzyme is a dimer...... with the archetypal fold of a copper-containing amine oxidase. The active site is the most open of any of those of the structurally characterized enzymes in the family and provides a ready explanation for its lysine oxidase-like activity....

  19. Extraction separation studies of uranium(VI) by amine oxides

    International Nuclear Information System (INIS)

    Ejaz, M.

    1975-01-01

    The extraction of uranium(VI) by two amine oxides, 4-(5-nonyl)pyridine oxide and trioctylamine oxide has been studied. The extraction behavior of these two N-oxides is compared. The dependence of extraction on the type of amine oxide and acid, nature of organic diluent, and amine oxide concentration has been investigated. The influence of the concentration of the metal and salting-out agents is described. The possible mechanism of extraction is discussed in the light of the results of extraction isotherms, loading radiodata, and log-log plots of amine oxide concentration vs distribution ratio. The separation factors for a number of metal ions are reported, and the separation of uranium from some fission elements has also been achieved

  20. Silver-catalyzed synthesis of amides from amines and aldehydes

    Science.gov (United States)

    Madix, Robert J; Zhou, Ling; Xu, Bingjun; Friend, Cynthia M; Freyschlag, Cassandra G

    2014-11-18

    The invention provides a method for producing amides via the reaction of aldehydes and amines with oxygen adsorbed on a metallic silver or silver alloy catalyst. An exemplary reaction is shown in Scheme 1: (I), (II), (III). ##STR00001##

  1. Amine-oxide hybrid materials for acid gas separations

    KAUST Repository

    Bollini, Praveen; Didas, Stephanie A.; Jones, Christopher W.

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams

  2. Solvent extraction of cerium (III) with high molecular weight amines

    International Nuclear Information System (INIS)

    Chatterjee, A.; Basu, S.

    1992-01-01

    The use of high molecular weight amines in the extraction of cerium (III) as EDTA complex from neutral aqueous medium is reported. The extraction condition was optimised from the study of effects of several variables like concentration of amine and EDTA pH nature of diluents etc. The method has been applied for the determination of cerium in few mineral samples. (author). 7 refs., 5 tabs

  3. Effects of dietary amines on the gut and its vasculature

    OpenAIRE

    Broadley, Kenneth John; Anwar, Mohammad Akhtar; Herbert, Amy Angharad; Fehler, Martina; Jones, Elen M.; Davies, W. E.; Kidd, Emma Jane; Ford, William Richard

    2009-01-01

    Trace amines, including tyramine and β-phenylethylamine (β-PEA), are constituents of many foods including chocolate, cheeses and wines and are generated by so-called ‘friendly’ bacteria such as Lactobacillus, Lactococcus and Enterococcus species, which are found in probiotics. We therefore examined whether these dietary amines could exert pharmacological effects on the gut and its vasculature. In the present study we examined the effects of tyramine and β-PEA on the contractile activity of gu...

  4. Biogenic amines in dry fermented sausages: a review.

    Science.gov (United States)

    Suzzi, Giovanna; Gardini, Fausto

    2003-11-15

    Biogenic amines are compounds commonly present in living organisms in which they are responsible for many essential functions. They can be naturally present in many foods such as fruits and vegetables, meat, fish, chocolate and milk, but they can also be produced in high amounts by microorganisms through the activity of amino acid decarboxylases. Excessive consumption of these amines can be of health concern because their not equilibrate assumption in human organism can generate different degrees of diseases determined by their action on nervous, gastric and intestinal systems and blood pressure. High microbial counts, which characterise fermented foods, often unavoidably lead to considerable accumulation of biogenic amines, especially tyramine, 2-phenylethylamine, tryptamine, cadaverine, putrescine and histamine. However, great fluctuations of amine content are reported in the same type of product. These differences depend on many variables: the quali-quantitative composition of microbial microflora, the chemico-physical variables, the hygienic procedure adopted during production, and the availability of precursors. Dry fermented sausages are worldwide diffused fermented meat products that can be a source of biogenic amines. Even in the absence of specific rules and regulations regarding the presence of these compounds in sausages and other fermented products, an increasing attention is given to biogenic amines, especially in relation to the higher number of consumers with enhanced sensitivity to biogenic amines determined by the inhibition of the action of amino oxidases, the enzymes involved in the detoxification of these substances. The aim of this paper is to give an overview on the presence of these compounds in dry fermented sausages and to discuss the most important factors influencing their accumulation. These include process and implicit factors as well as the role of starter and nonstarter microflora growing in the different steps of sausage production

  5. Facile and Green Synthesis of Saturated Cyclic Amines

    Directory of Open Access Journals (Sweden)

    Arruje Hameed

    2017-10-01

    Full Text Available Single-nitrogen containing saturated cyclic amines are an important part of both natural and synthetic bioactive compounds. A number of methodologies have been developed for the synthesis of aziridines, azetidines, pyrrolidines, piperidines, azepanes and azocanes. This review highlights some facile and green synthetic routes for the synthesis of unsubstituted, multisubstituted and highly functionalized saturated cyclic amines including one-pot, microwave assisted, metal-free, solvent-free and in aqueous media.

  6. Calcium(ii)-catalyzed enantioselective conjugate additions of amines.

    Science.gov (United States)

    Uno, Brice E; Dicken, Rachel D; Redfern, Louis R; Stern, Charlotte M; Krzywicki, Greg G; Scheidt, Karl A

    2018-02-14

    The direct enantioselective chiral calcium(ii)·phosphate complex (Ca[CPA] 2 )-catalyzed conjugate addition of unprotected alkyl amines to maleimides was developed. This mild catalytic system represents a significant advance towards the general convergent asymmetric amination of α,β-unsaturated electrophiles, providing medicinally relevant chiral aminosuccinimide products in high yields and enantioselectivities. Furthermore, the catalyst can be reused directly from a previously chromatographed reaction and still maintain both high yield and selectivity.

  7. Catalyst Deactivation Reactions : The Role of Tertiary Amines Revisited

    NARCIS (Netherlands)

    Novarino, Elena; Rios, Itzel Guerrero; van der Veer, Siebe; Meetsma, Auke; Hessen, Bart; Bouwkamp, Marco W.

    2011-01-01

    Decamethylzirconocene cation [Cp*2ZrMe](+) (2) decomposes in bromobenzene-d(5) solution to generate sigma-aryl species [Cp*Zr-2(2-C6H4Br-kappa Br,C)][B(C6F5)(4)] (3). This a-bond metathesis reaction is catalyzed by tertiary amines via a two-step mechanism, in which the amine acts as a proton relay.

  8. Nanoprecipitation in bearing steels

    International Nuclear Information System (INIS)

    Barrow, A.T.W.; Rivera-Diaz-del-Castillo, P.E.J.

    2011-01-01

    θ-phase is the main hardening species in bearing steels and appears in both martensitically and bainitically hardened microstructures. This work presents a survey of the microstrucural features accompanying nanoprecipitation in bearing steels. Nanoprecipitate structures formed in 1C-1.5Cr wt.% with additions of Cr, Mn, Mo, Si and Ni are studied. The work is combined with thermodynamic calculations and neural networks to predict the expected matrix composition, and whether this will transform martensitically or bainitically. Martensite tetragonality, composition and the amount of retained austenite are related to hardness and the type of nanoprecipitate structures in martensitic grades. The θ-phase volume fraction, the duration of the bainite to austenite transformation and the amount of retained austenite are related to hardness and a detailed quantitative description of the precipitate nanostructures. Such description includes compositional studies using energy-dispersive spectroscopy, which shows that nanoprecipitate formation takes place under paraequilibrium. Special attention is devoted to a novel two-step bainite tempering process which shows maximum hardness; we prove that this is the most effective process for incorporating solute into the precipitates, which are finer than those resulting from one-step banitic transformation processes.

  9. Superconducting bearings in flywheels

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, T.A.; Campbell, A.M.; Ganney, I.; Lo, W. [Cambridge Univ. (United Kingdom). Interdisciplinary Research Centre in Superconductivity (IRC); Twardowski, T. [International Energy Systems, Chester High Road, Neston, South Wirral (United Kingdom); Dawson, B. [British Nuclear Fuels, Capenhurst, South Wirral (United Kingdom)

    1998-05-01

    Investigations are being carried out into the use of superconducting magnetic bearings to levitate energy storage flywheels. In a planned program of work, Cambridge University are aiming to produce a practical bearing system for Pirouette(TM). The Pirouette(TM) system is designed to provide 5 kWh of recoverable energy which is currently recoverable at a rate of 5 kW (future revisions will provide up to 50 kW). IES (a British Nuclear Fuels subsidiary) the owners of the Pirouette(TM) machine have supplied Cambridge with a flywheel. This flywheel weighs >40 kg and is being levitated using an Evershed-type arrangement in which the superconductor is being used to stabilize the interaction between two magnets. To date we have demonstrated stable levitation in static and low speed tests in a rig designed for low speeds of rotation in air. A second rig which is currently under construction at BNFL will run in vacuum at speeds of up to 50 (orig.) 5 refs.

  10. Production of biogenic amines in "Salamini italiani alla cacciatora PDO".

    Science.gov (United States)

    Coı X0308 Sson, Jean Daniel; Cerutti, Caterina; Travaglia, Fabiano; Arlorio, Marco

    2004-06-01

    Various fermented and seasoned foods such as cheese, sauerkraut, wine, beer and meat products may contain biogenic amines. The aim of this paper was to describe the presence of some biogenic amines (histamine, tyramine, tryptamine, 2-phenylethylamine) in "Salamini italiani alla cacciatora PDO", a typical fermented-ripened dry sausage widely consumed in Italy. Total level of biogenic amines in commercial samples ranged from 71 to 586 mg kg(-1). The amine recovered in higher concentrations was tyramine (372 mg kg(-1)) followed by histamine (165 mg kg(-1)). The second aim of this work was the quality control of the production in order to determine the parameters influencing the presence of biogenic amines in ripened salami. Sausages sampled for analysis during production, manipulation and ripening showed the presence of tyramine (64.4 mg kg(-1)) only after 15 days of fermentation. All investigated biogenic amines were detected in "Salamini" after 21 days of fermentation. We suggest the control of biogenic as important tool to establish the better condition of preservation of "Salamini italiani alla cacciatore PDO" during their shelf-life.

  11. STUDIES ON VINYL POLYMERIZATION WITH INITIATION SYSTEM CONTAINING AMINE DERIVATIVES

    Institute of Scientific and Technical Information of China (English)

    QIU Kunyuan; ZHANG Jingyi; FENG Xinde(S. T. Voong)

    1983-01-01

    Two main types of amine-containing initiation systems were studied in this work. In the case of MMA polymerization initiated by BPO-amine (DMT, DHET, DMA) redox systems, it was found that the polymerization rate and colour stability of the polymer for different amine systems were in the following order: DMT≈DHET>DMA. Accordingly, BPO-DMT and BPO-DHET are effective initiators. In the case of MEMA polymerization by amine (DMT, DHET, DMA) alone, it was found that the polymerization rate and the percentage of conversion for these different amine systems were in the following order: DMT≥DHET>DMA. The polymerization rate and the percentage of conversion also increased with the increase of DMT concentration. From the kinetic investigation the rate equation of Rp=K [DMT]1/2 [MEMA]3/2 was obtained, and the overall activation energy of polymerization was calculated to be 34.3 KJ/mol (8.2 Kcal/mol). Moreover, the polymerization of MEMA in the presence of DMT was strongly inhibited by hydroquinone, indicating the polymerization being free radical in nature. From these results, the mechanism of MEMA polymerization initiated by amine was proposed.

  12. Biogenic amine formation and bacterial contribution in Natto products.

    Science.gov (United States)

    Kim, Bitna; Byun, Bo Young; Mah, Jae-Hyung

    2012-12-01

    Twenty-one Natto products currently distributed in Korea were analysed for biogenic amine contents and tested to determine physicochemical and bacterial contributions to biogenic amine formation. Among them, nine products (about 43%) had β-phenylethylamine or tyramine contents greater than the toxic dose (30mg/kg and 100mg/kg, respectively) of each amine, although no products showed total amounts of biogenic amines above the harmful level (1000mg/kg), which indicates that the amounts of biogenic amines in some Natto products are not within the safe level for human health. From four different Natto products, that contained noticeable levels of β-phenylethylamine and tyramine, 80 bacterial strains were isolated. All the strains were identified to be Bacillus subtilis and highly capable of producing β-phenylethylamine and tyramine. Therefore, it seems likely that the remarkable contents of β-phenylethylamine and tyramine in Natto predominantly resulted from the strains highly capable of producing those amines present in the food. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Heterocyclic amines in meat and meat products

    Directory of Open Access Journals (Sweden)

    Aliye BULGAN

    2013-06-01

    Full Text Available Heterocyclic amines (HA are the mutagenic/carcinogenic compounds which generate as a result of cooking of red meat, poultry meat and fish fillets at high temperatures. Up to 20 different HAs were detected and classified in the researches that conducted on these types of meats cooked at high temperatures. HAs are the products of Maillard reactions and the Strecker degredation of main precursors such as creatine/creatinine, aminoacid and the polysaccharides. Many physical and chemical factors effect the formation of HAs. Thus, it was reported by many researchers that utilizing coating and marination processes in addition to using natural and synthetic antioxidants and seasonings-plant extracts were effective on inhibiting/decreasing the formation of HAs. Additionally, boiling/steaming and microwave cooking methodologies were recommended instead of barbecuing, grilling or frying to inhibit/decrease the formation of HAs. The HAs formed in meat and meat products and the factors which have effects on the formation of HAs are presented in this review.

  14. Brain perfusion imaging with iodinated amines

    International Nuclear Information System (INIS)

    Kung, H.F.

    1989-01-01

    Traditional nuclear medicine brain study using 99m Tc pertechnetate, glucoheptonate or diethlenetriaminepentacetic acid (DTPA) and planar imaging has experienced a significant decline in the past 10 years. This is mainly due to the introduction of X-ray CT and more recently the nuclear magnetic resonance (NMR) imaging, by which detailed morphology of the brain, including the detection of breakdown of the blood-brain barrier, can be obtained. The nuclear medicine brain imaging is only prescribed as a complementary test when X-ray CT is negative or equivocal and clinical suspicion remains. The attention of nuclear medicine brain imaging has been shifted from the detection of the breakdown of the blood-brain barrier to the study of brain function-perfusion, metabolism, and receptor binding, etc. The functional brain imaging provides diagnostic information usually unattainable by other radiological techniques. In this article, the iodinated amines as brain perfusion imaging agents are reviewed. Potential clinical application of these agents is discussed

  15. Computational design of rolling bearings

    CERN Document Server

    Nguyen-Schäfer, Hung

    2016-01-01

    This book comprehensively presents the computational design of rolling bearings dealing with many interdisciplinary difficult working fields. They encompass elastohydrodynamics (EHD), Hertzian contact theory, oil-film thickness in elastohydrodynamic lubrication (EHL), bearing dynamics, tribology of surface textures, fatigue failure mechanisms, fatigue lifetimes of rolling bearings and lubricating greases, Weibull distribution, rotor balancing, and airborne noises (NVH) in the rolling bearings. Furthermore, the readers are provided with hands-on essential formulas based on the up-to-date DIN ISO norms and helpful examples for computational design of rolling bearings. The topics are intended for undergraduate and graduate students in mechanical and material engineering, research scientists, and practicing engineers who want to understand the interactions between these working fields and to know how to design the rolling bearings for automotive industry and many other industries.

  16. Development of I-123-labeled amines for brain studies: localization of I-123 iodophenylalkyl amines in rat brain

    International Nuclear Information System (INIS)

    Winchell, H.S.; Baldwin, R.M.; Lin, T.H.

    1980-01-01

    Localization in rat brain of forty iodophenylalkyl amines labeled with I-123 was evaluated in an attempt to develop I-123-labeled amines useful for brain studies. For the amines studied, the highest activity in brain and the brain-to-blood activity ratios ranked p > m > o as related to iodine position on the benzene ring: for alkyl groups the rank order was α-methylethyl > ethyl > methyl > none; for N additions it was single lipophilic group > H > two lipophilic groups. It is suggested that introduction of a halogen into the ring structure of many amines results in greater concentration of the agent in brain than is seen with the nonhalogenated parent compound. The agent N-isopropyl-p-iodoamphetamine was chosen for further study because, in the rat, it showed high brain activity (1.57%/g) and brain-blood ratio (12.6) at 5 min

  17. Grease lubrication in rolling bearings

    CERN Document Server

    Lugt, Piet M

    2012-01-01

    The definitive book on the science of grease lubrication for roller and needle bearings in industrial and vehicle engineering. Grease Lubrication in Rolling Bearings provides an overview of the existing knowledge on the various aspects of grease lubrication (including lubrication systems) and the state of the art models that exist today. The book reviews the physical and chemical aspects of grease lubrication, primarily directed towards lubrication of rolling bearings. The first part of the book covers grease composition, properties and rheology, including thermal

  18. Hydrostatic and hybrid bearing design

    CERN Document Server

    Rowe, W B

    1983-01-01

    Hydrostatic and Hybrid Bearing Design is a 15-chapter book that focuses on the bearing design and testing. This book first describes the application of hydrostatic bearings, as well as the device pressure, flow, force, power, and temperature. Subsequent chapters discuss the load and flow rate of thrust pads; circuit design, flow control, load, and stiffness; and the basis of the design procedures and selection of tolerances. The specific types of bearings, their design, dynamics, and experimental methods and testing are also shown. This book will be very valuable to students of engineering des

  19. Transition Metal Free C-N Bond Forming Dearomatizations and Aryl C-H Aminations by in Situ Release of a Hydroxylamine-Based Aminating Agent.

    Science.gov (United States)

    Farndon, Joshua J; Ma, Xiaofeng; Bower, John F

    2017-10-11

    We outline a simple protocol that accesses directly unprotected secondary amines by intramolecular C-N bond forming dearomatization or aryl C-H amination. The method is dependent on the generation of a potent electrophilic aminating agent released by in situ deprotection of O-Ts activated N-Boc hydroxylamines.

  20. Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C−O and C−C Bond Activation

    KAUST Repository

    Yue, Huifeng

    2017-03-15

    An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.

  1. Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C−O and C−C Bond Activation

    KAUST Repository

    Yue, Huifeng; Guo, Lin; Liao, Hsuan-Hung; Cai, Yunfei; Zhu, Chen; Rueping, Magnus

    2017-01-01

    An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.

  2. Monoanionic 99mTc-tricarbonyl-aminopolycarboxylate complexes with uncharged pendant groups: Radiosynthesis and evaluation as potential renal tubular tracers.

    Science.gov (United States)

    Lipowska, Malgorzata; Klenc, Jeffrey; Jarkas, Nashwa; Marzilli, Luigi G; Taylor, Andrew T

    2017-04-01

    99m Tc(CO) 3 -nitrilotriacetic acid, 99m Tc(CO) 3 (NTA), is a new renal tubular agent with pharmacokinetic properties comparable to those of 131 I-OIH but the clearance of 99m Tc(CO) 3 (NTA) and 131 I-OIH is still less than the clearance of PAH, the gold standard for the measurement of effective renal plasma flow. At physiological pH, dianionic 99m Tc(CO) 3 (NTA) has a mononegative inner metal-coordination sphere and a mononegative uncoordinated carboxyl group. To evaluate alternate synthetic approaches, we assessed the importance of an uncoordinated carboxyl group, long considered essential for tubular transport, by evaluating the pharmacokinetics of three analogs with the 99m Tc(CO) 3 (NTA) metal-coordination sphere but with uncharged pendant groups. 99m Tc(CO) 3 complexes with N-(2-acetamido)iminodiacetic acid (ADA), N-(2-hydroxyethyl)iminodiacetic acid (HDA) and N-(fluoroethyl)iminodiacetic acid (FEDA) were prepared using a tricarbonyl kit and isolated by HPLC. The pharmacokinetics were evaluated in Sprague-Dawley rats, with 131 I-OIH as an internal control; urine was analyzed for metabolites. Plasma protein binding and erythrocyte uptake were determined from the 10min blood samples. Re(CO) 3 (FEDA), the analog of 99m Tc(CO) 3 (FEDA), was prepared and characterized. 99m Tc(CO) 3 (ADA), 99m Tc(CO) 3 (HDA) and 99m Tc(CO) 3 (FEDA) were efficiently prepared as a single species with high radiochemical purities (>99%). These new monoanionic 99m Tc(CO) 3 tracers with uncharged dangling groups all showed rapid blood clearance and high specificity for renal excretion. Activity in the urine, as a percent of 131 I-OIH at 10 and 60min, was 96% and 99% for ADA, 96% and 100% for HDA, and 100% and 99% for FEDA, respectively. Each new tracer was excreted unchanged in the urine. The Re(CO) 3 (FEDA) structure adds compelling evidence that such 99m Tc(CO) 3 (NTA) analogs have metal-coordination spheres identical to that of 99m Tc(CO) 3 (NTA). New tracers lacking the negatively

  3. Donor-π-bridge-acceptor type polymeric materials with pendant electron-withdrawing groups for electrochromic applications

    International Nuclear Information System (INIS)

    Du, Qing; Wei, Youxiu; Zheng, Jianming; Xu, Chunye

    2014-01-01

    Highlights: • Donor-π-bridge-acceptor copolymers with different electrophilic groups were synthesized. • Electrochromic devices composed of PBDTTPAs layers, as the working electrode, and vanadium pentoxide, as the counter electrode, were fabricated and evaluated. • The PBDTTPA-CHO film and device show multicolor electrochromic behavior which exhibited vivid yellow, green, and gray with better electrochromic performance than PBDTTPA-COOH. - Abstract: A novel donor-π-bridge-acceptor copolymer, PBDTTPA-CHO, containing 4-(Bis(4-bromophenyl)-amino)benzaldehyde (TPA-CHO) and 4,8-bis-(2-ethyl- hexyloxy)-oxybenzo-[1,2-b:3,4-b’]dithiophene (BDT), was successfully synthesized using Stille coupling polymerization, and the pendant aldehyde group was modified with cyanoacetic acid to synthesize another polymer, PBDTTPA-COOH. Each of these new polymers are soluble in organic solvents and can be cast onto rigid or flexible substrates. The polymers with different electrophilic groups exhibit different electrochromic behaviors, including different colors, driving voltages and transmittances. The polymer film of PBDTTPA-CHO manifests reversible electrochemical oxidation and reduction accompanied by multicolor changes from its yellow neutral state to a highly absorbent green semi-oxidized state and a gray fully oxidized state, its transmittance change at 601 nm is 43%. PBDTTPA-COOH switches between orange and light green. We fabricated and evaluated electrochromic devices using a PBDTTPA layer as the working electrode and vanadium pentoxide as the counter electrode. With the contribution of counter electrodes, devices of both polymers show similar color changes but higher transmittance than their films

  4. Ristripatsid Eesti 12.–13. sajandi laibakalmistutes: kas ehted või usu tunnused? / The cross-shaped pendants of inhumation burials in 12th-13th century Estonia: adornments or signs of belief?

    Directory of Open Access Journals (Sweden)

    Tuuli Kurisoo

    2012-01-01

    Full Text Available Cross-shaped pendants are one of the most discussed symbolically laden artefacts among Estonian archaeological material. The beginning of the distribution of cross-shaped pendants dates back to 11th century when the artefacts, though scarce, appear. The number of such pendants increases noticeably at the very end of the Iron Age. Due to the ambiguous entity of cross and time context, cross-pendants have been interpreted either as symbols of Christian faith, as pieces of adornment not affiliated with Christianity, or as objects with magical qualities. In this paper I study pendants found in the inhumation cemeteries of Estonia. Only those provide us with an archaeological context which shows precisely who could have worn them and how. The analyzed cross-pendants were found at Pada, Kaberla, Kukruse, Haimre and Tammiku cemeteries and from the early burials in Viru-Nigula churchyard. As artefacts, the cross pendants are more or less stylized Greek crosses. In most cases the pendants were either used as a part of jewellery or worn singularly around the neck area. From the total of 48 analyzed cross-pendants one fourth could be interpreted as locally produced items. Of local origin are probably lead pendants from Pada cemetery, heads of decorative pins worn as cross-shaped pendants from Viru-Nigula and Kaberla cemeteries, and obvious scrap and unfinished pendant crosses. In addition, I would like to draw attention that cross-pendants from inhumation burials do not contain many widespread forms, such as ‘Scandinavian’ and some other widespread Russian origin types, which have been found in hoards, from hill-forts and cremation burials. This observation could confirm that cross pendants from 12th–13th century inhumation burials were communally recognized and some of them were locally manufactured. As the next stage of my investigation I studied different occurrence contexts of cross pendants in cemeteries and burials: the location of burials with

  5. Determination of rate constants of N-alkylation of primary amines by 1H NMR spectroscopy.

    Science.gov (United States)

    Li, Chenghong

    2013-09-05

    Macromolecules containing N-diazeniumdiolates of secondary amines are proposed scaffolds for controlled nitrogen oxide (NO) release medical applications. Preparation of these compounds often involves converting primary amine groups to secondary amine groups through N-alkylation. However, N-alkylation results in not only secondary amines but tertiary amines as well. Only N-diazeniumdiolates of secondary amines are suitable for controlled NO release; therefore, the yield of secondary amines is crucial to the total NO load of the carrier. In this paper, (1)H NMR spectroscopy was used to estimate the rate constants for formation of secondary amine (k1) and tertiary amine (k2) for alkylation reagents such as propylene oxide (PO), methyl acrylate (MA), and acrylonitrile (ACN). At room temperature, the ratio of k2/k1 for the three reactions was found to be around 0.50, 0.026, and 0.0072.

  6. Detection of cometary amines in samples returned by Stardust

    Science.gov (United States)

    Glavin, D. P.; Dworkin, J. P.; Sandford, S. A.

    2008-02-01

    The abundances of amino acids and amines, as well as their enantiomeric compositions, were measured in samples of Stardust comet-exposed aerogel and foil using liquid chromatography with UV fluorescence detection and time of flight mass spectrometry (LC-FD/ToF-MS). A suite of amino acids and amines including glycine, L-alanine, β-alanine (BALA), γ-amino-n-butyric acid (GABA), ɛ-amino-n-caproic acid (EACA), ethanolamine (MEA), methylamine (MA), and ethylamine (EA) were identified in acid-hydrolyzed, hot-water extracts of these Stardust materials above background levels. With the exception of MA and EA, all other primary amines detected in cometexposed aerogel fragments C2054,4 and C2086,1 were also present in the flight aerogel witness tile that was not exposed to the comet, indicating that most amines are terrestrial in origin. The enhanced relative abundances of MA and EA in comet-exposed aerogel compared to controls, coupled with MA to EA ratios (C2054,4: 1.0 ± 0.2; C2086,1: 1.8 ± 0.2) that are distinct from preflight aerogels (E243-13C and E243-13F: 7 ± 3), suggest that these volatile amines were captured from comet Wild 2. MA and EA were present predominantly in an acid-hydrolyzable bound form in the aerogel, rather than as free primary amines, which is consistent with laboratory analyses of cometary ice analog materials. It is possible that Wild 2 MA and EA were formed on energetically processed icy grains containing ammonia and approximately equal abundances of methane and ethane. The presence of cometary amines in Stardust material supports the hypothesis that comets were an important source of prebiotic organic carbon and nitrogen on the early Earth.

  7. The ozonolysis of primary aliphatic amines in fine particles

    Science.gov (United States)

    Zahardis, J.; Geddes, S.; Petrucci, G. A.

    2008-02-01

    The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2- and NO3- ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3- (HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10-7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10-3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

  8. The ozonolysis of primary aliphatic amines in fine particles

    Directory of Open Access Journals (Sweden)

    J. Zahardis

    2008-02-01

    Full Text Available The oxidative processing by ozone of the particulate amines octadecylamine (ODA and hexadecylamine (HDA is reported. Ozonolysis of these amines resulted in strong NO2 and NO3 ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3 (HNO3. For ozonized mixed particles containing ODA or HDA + oleic acid (OL, with pO3≥3×10–7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines and stabilized Criegee intermediates (SCI or secondary ozonides (for amides from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10−3 atm for 17 s. This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3, formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

  9. Biogenic amines in Italian Pecorino cheese

    Directory of Open Access Journals (Sweden)

    Maria eSchirone

    2012-05-01

    Full Text Available The quality of distinctive artisanal cheeses is closely associated with the territory of production and its traditions. Pedoclimatic characteristics, genetic autochthonous variations and anthropic components create an environment so specific that it would be extremely difficult to reproduce elsewhere. Pecorino cheese is included in this sector of the market and is widely diffused in Italy (approximately 53.727t of production. Pecorino is a common name given to indicate Italian cheeses made exclusively from pure ewes' milk characterized by a high content of fat matter and it is mainly produced in the middle and south of Italy by traditional procedures from raw or thermized milk. The microbiota plays a major role in the development of the organoleptic characteristics of the cheese but it can also be responsible for the accumulation of undesirable substances, such as biogenic amines (BA. Several factors can contribute to the qualitative and quantitative profiles of BA’s in Pecorino cheese such as environmental hygienic conditions, pH, salt concentration, aw, fat content, pasteurization of milk, decarboxylase microorganisms, starter cultures, temperature and time of ripening, storage, part of the cheese (core, edge and the presence of cofactor. Generally, the total content of BA’s can range from about 100-2400 mg/kg, with a prevalence of toxicologically important BA’s, tyramine and histamine. The presence of BA in Pecorino cheeses is becoming increasingly important to consumers and cheese-maker alike, due to the potential threats of toxicity to humans and consequent trade implications.

  10. Superconducting bearings for flywheel applications

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamsen, Asger Bech

    2001-05-01

    A literature study on the application of superconducting bearings in energy storage flywheel systems. The physics of magnetic levitation and superconductors are presented in the first part of the report, followed by a discussion of the literature found on the applications of superconducting bearings in flywheels. (au)

  11. Superconducting bearings for flywheel applications

    DEFF Research Database (Denmark)

    Abrahamsen, A.B.

    2001-01-01

    A literature study on the application of superconducting bearings in energy storage flywheel systems. The physics of magnetic levitation and superconductors are presented in the first part of the report, followed by a discussion of the literature found onthe applications of superconducting bearings...

  12. Space Station alpha joint bearing

    Science.gov (United States)

    Everman, Michael R.; Jones, P. Alan; Spencer, Porter A.

    1987-01-01

    Perhaps the most critical structural system aboard the Space Station is the Solar Alpha Rotary Joint which helps align the power generation system with the sun. The joint must provide structural support and controlled rotation to the outboard transverse booms as well as power and data transfer across the joint. The Solar Alpha Rotary Joint is composed of two transition sections and an integral, large diameter bearing. Alpha joint bearing design presents a particularly interesting problem because of its large size and need for high reliability, stiffness, and on orbit maintability. The discrete roller bearing developed is a novel refinement to cam follower technology. It offers thermal compensation and ease of on-orbit maintenance that are not found in conventional rolling element bearings. How the bearing design evolved is summarized. Driving requirements are reviewed, alternative concepts assessed, and the selected design is described.

  13. Flywheel Challenge: HTS Magnetic Bearing

    International Nuclear Information System (INIS)

    Werfel, F N; Floegel-Delor, U; Riedel, T; Rothfeld, R; Wippich, D; Goebel, B

    2006-01-01

    A 200 mm cylindrical engineering prototype high temperature superconducting (HTS) was designed and fabricated. Measurements show that the 17 kg PM rotor can suspend safely 1000 kg in axial direction and 470 kg radially. The rationale for the bearing performance is to stabilize a 400 kg rotor of a new compact 5 kWh/280 kW flywheel energy storage system (COM - FESS). Measurements of the magnetic bearing force, stiffness and drag-torque are presented indicated the successful targeting a milestone in the HTS bearing technology. The influence of the PM configuration and the YBCO temperature on the bearing performance was experimentally studied, providing high-force or high-stiffness behaviour. The axial stiffness 5 kN/mm at 0.5 mm displacement is the highest value of a HTS bearing we know

  14. Journal bearing impedance descriptions for rotordynamic applications

    NARCIS (Netherlands)

    Childs, D.W.; Moes, H.; Leeuwen, van H.J.

    1977-01-01

    Bearing impedance vectors are introduced for plain journal bearings which define the bearing reaction force components as a function of the bearing motion. Impedance descriptions are developed directly for the approximate Ocvirk (short) and Sommerfeld (long) bearing solutions. The impedance vector

  15. Yb(OTf){sub 3}-catalyzed one-pot three component synthesis for tertiary amines

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bum Seok; Kim, Ji Hye; Nam, Tae Kyu; Jang, Doo Ok [Dept. of Chemistry, Yonsei University, Wonju (Korea, Republic of)

    2015-07-15

    Tertiary amine functionality is found in many natural bioactive products such as alkaloids, amino acids, nucleic acids, pharmaceuticals, and agrochemicals. Tertiary amines have also been used as building blocks for nitrogen-containing organic compounds and synthetic polymers. A one-pot method for direct reductive amination of aldehydes has been developed to synthesize tertiary amines using HMDS as a nitrogen source in the presence of Yb(OTf ){sub 3}. With a stoichiometric amount of HMDS, the reaction afforded the desired tertiary amines without competitive reduction of the parent carbonyl compounds. This reaction offers a convenient and efficient protocol for synthesizing aromatic and aliphatic tertiary amines under mild reaction conditions.

  16. The chemistry of amine radical cations produced by visible light photoredox catalysis

    Directory of Open Access Journals (Sweden)

    Jie Hu

    2013-10-01

    Full Text Available Amine radical cations are highly useful reactive intermediates in amine synthesis. They have displayed several modes of reactivity leading to some highly sought-after synthetic intermediates including iminium ions, α-amino radicals, and distonic ions. One appealing method to access amine radical cations is through one-electron oxidation of the corresponding amines under visible light photoredox conditions. This approach and subsequent chemistries are emerging as a powerful tool in amine synthesis. This article reviews synthetic applications of amine radical cations produced by visible light photocatalysis.

  17. Chromosomal localization of the human vesicular amine transporter genes

    Energy Technology Data Exchange (ETDEWEB)

    Peter, D.; Finn, P.; Liu, Y.; Roghani, A.; Edwards, R.H.; Klisak, I.; Kojis, T.; Heinzmann, C.; Sparkes, R.S. (UCLA School of Medicine, Los Angeles, CA (United States))

    1993-12-01

    The physiologic and behavioral effects of pharmacologic agents that interfere with the transport of monoamine neurotransmitters into vesicles suggest that vesicular amine transport may contribute to human neuropsychiatric disease. To determine whether an alteration in the genes that encode vesicular amine transport contributes to the inherited component of these disorders, the authors have isolated a human cDNA for the brain transporter and localized the human vesciular amine transporter genes. The human brain synaptic vesicle amine transporter (SVAT) shows unexpected conservation with rat SVAT in the regions that diverge extensively between rat SVAT and the rat adrenal chromaffin granule amine transporter (CGAT). Using the cloned sequences with a panel of mouse-human hybrids and in situ hybridization for regional localization, the adrenal CGAT gene (or VAT1) maps to human chromosome 8p21.3 and the brain SVAT gene (or VAT2) maps to chromosome 10q25. Both of these sites occur very close to if not within previously described deletions that produce severe but viable phenotypes. 26 refs., 3 figs., 1 tab.

  18. Metal and base free synthesis of primary amines via ipso amination of organoboronic acids mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA).

    Science.gov (United States)

    Chatterjee, Nachiketa; Goswami, Avijit

    2015-08-07

    A metal and base free synthesis of primary amines has been developed at ambient temperature through ipso amination of diversely functionalized organoboronic acids, employing a combination of [bis(trifluoroacetoxy)iodo]benzene (PIFA)-N-bromosuccinimide (NBS) and methoxyamine hydrochloride as the aminating reagent. The amines were primarily obtained as their trifluoroacetate salts which on subsequent aqueous alkaline work up provided the corresponding free amines. The combination of PIFA-NBS is found to be the mildest choice compared to the commonly used strong bases (e.g. n-BuLi, Cs2CO3) for activating the aminating agent. The reaction is expected to proceed via activation of the aminating reagent followed by B-N 1,2-aryl migration.

  19. Detection of amines with extended distyrylbenzenes by strip assays.

    Science.gov (United States)

    Kumpf, Jan; Freudenberg, Jan; Fletcher, Katharyn; Dreuw, Andreas; Bunz, Uwe H F

    2014-07-18

    We herein describe the synthesis and property evaluation of three novel aldehyde-substituted pentameric phenylenevinylenes carrying branched oligo(ethylene glycol) (swallowtail, Sw) substituents. The targets were synthesized by a combination of Heck coupling and Wittig or Horner reactions of suitable precursor modules. If the pentameric phenylenevinylene carries only two of these Sw substituents, it is no longer water-soluble. When six of the Sw substituents are attached, regardless of their position, the pentameric phenylenevinylenes are well water-soluble. The dialdehydes were investigated with respect to their amine-sensing capabilities both in water as well as in the solid state, sprayed onto thin layer chromatography (TLC) plates (alox, silica gel, reversed phase silica gel). The recognition of amine vapors using the sprayed-on phenylenevinylene dialdehydes is superb and allows the identification of different amines on regular silica TLC plates via color changes, analyzed by a statistical tool, the multivariate analysis of variance (MANOVA) protocol.

  20. Clustering of amines and hydrazines in atmospheric nucleation

    Science.gov (United States)

    Li, Siyang; Qu, Kun; Zhao, Hailiang; Ding, Lei; Du, Lin

    2016-06-01

    It has been proved that the presence of amines in the atmosphere can enhance aerosol formation. Hydrazine (HD) and its substituted derivatives, monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH), which are organic derivatives of amine and ammonia, are common trace atmospheric species that may contribute to the growth of nucleation clusters. The structures of the hydrazine and amine clusters containing one or two common nucleation molecules (ammonia, water, methanol and sulfuric acid) have been optimized using density functional theory (DFT) methods. The clusters growth mechanism has been explored from the thermochemistry by calculating the Gibbs free energies of adding an ammonia, water, methanol or sulfuric acid molecule step by step at room temperature, respectively. The results show that hydrazine and its derivatives could enhance heteromolecular homogeneous nucleation in the earth's atmosphere.

  1. Enzymatic network for production of ether amines from alcohols

    DEFF Research Database (Denmark)

    Palacio, Cyntia M.; Crismaru, Ciprian G.; Bartsch, Sebastian

    2016-01-01

    We constructed an enzymatic network composed of three different enzymes for the synthesis of valuable ether amines. The enzymatic reactions are interconnected to catalyze the oxidation and subsequent transamination of the substrate and to provide cofactor recycling. This allows production...... of the desired ether amines from the corresponding ether alcohols with inorganic ammonium as the only additional substrate. To examine conversion, individual and overall reaction equilibria were established. Using these data, it was found that the experimentally observed conversions of up to 60% observed...... for reactions containing 10mM alcohol and up to 280mM ammonia corresponded well to predicted conversions. The results indicate that efficient amination can be driven by high concentrations of ammonia and may require improving enzyme robustness for scale-up....

  2. Eastern slopes grizzly bear project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-01

    The cumulative effects of human activities on the grizzly bears in the central Canadian Rockies are not well known. As a result, a project was initiated in 1994 to address the urgent requirement for accurate scientific information on the habitat and populations of grizzly bears in the area of the Banff National Park and Kananaskis Country. This area is probably the most heavily used and developed area where the grizzly still survives. The information gathered throughout the course of this study will be used to better protect and manage the bears and other sensitive carnivores in the region. Using telemetry, researchers are monitoring 25 grizzly bears which were radio-collared in a 22,000 square-kilometer area in the upper Bow Valley drainage of the eastern Alberta slopes. The researchers involved in the project are working with representatives from Husky Oil and Talisman Energy on the sound development of the Moose Mountain oil and gas field without adversely affecting the grizzly bear population. Information collected over seven years indicated that the grizzly bears have few and infrequent offspring. Using the information gathered so far, the location of the Moose Mountain to Jumping Pound pipeline was carefully selected, since the bears recover very slowly from high mortality, and also considering that the food and cover had already been compromised by the high number of roads, trails and other human activities in the area. The status of the population and habitat of the grizzly bear will be assessed upon the conclusion of the field research phase in 2001. Models will be updated using the data obtained during eight years and will assist in the understanding of complex variables that affect grizzly bears.

  3. EFFECT OF BEARING MACROGEOMETRY ON BEARING PERFORMANCE IN ELASTOHYDRODYNAMIC LUBRICATION

    Directory of Open Access Journals (Sweden)

    Emin GÜLLÜ

    2000-01-01

    Full Text Available During manufacturing, ideal dimension and mutual positioning of machine elements proposed in project desing can be achieved only within certain range of tolerances. These tolerances, being classified in two groups, related to micro and macro geometry of machine elements, don't have to effect the functioning of these elements. So, as for all machine elements, investigation of the effects of macro and micro tolerances for journal bearings is important. In this study, we have investigated the effect of macro geometric irregularities of journal bearings on performance characteristics. In this regard, we have studied the change of bearing performance in respect to deviation from ideal circle for an elliptic shaft with small ovality rolling in circular journal bearing.

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

    Science.gov (United States)

    Singh, Ashok K; Singh, Prerna; Banerjee, Shibdas; Mehtab, Sameena

    2009-02-02

    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 (L(1)) 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 (L(2)) 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 L(1): PVC:1-CN:NaTPB in the ratio of 6: 32: 58: 4 (w/w; mg). The performance of the membrane based on L(1) was compared with polymeric membrane electrode (PME) as well as with coated graphite electrode (CGE). The electrodes exhibit Nernstian slope for Tb(3+) 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 10s and 8s, 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 months. The CGE was used as indicator electrode in the potentiometric titration of Tb(3+) ions with EDTA and in determination of fluoride ions in various samples. It can also be used in direct determination of Tb(3+) ions in tap water and various binary mixtures with quantitative results.

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

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Ashok K. [Department of Chemistry, Indian Institute of Technology-Roorkee, Roorkee 247 667 (India)], E-mail: akscyfcy@iitr.ernet.in; Singh, Prerna; Banerjee, Shibdas; Mehtab, Sameena [Department of Chemistry, Indian Institute of Technology-Roorkee, Roorkee 247 667 (India)

    2009-02-02

    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 (L{sub 1}) 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 (L{sub 2}) 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 L{sub 1}: PVC:1-CN:NaTPB in the ratio of 6: 32: 58: 4 (w/w; mg). The performance of the membrane based on L{sub 1} was compared with polymeric membrane electrode (PME) as well as with coated graphite electrode (CGE). The electrodes exhibit Nernstian slope for Tb{sup 3+} ions with limits of detection of 3.4 x 10{sup -8} mol L{sup -1} for PME and 5.7 x 10{sup -9} mol L{sup -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 months. The CGE was used as indicator electrode in the potentiometric titration of Tb{sup 3+} ions with EDTA and in determination of fluoride ions in various samples. It can also be used in direct determination of Tb{sup 3+} ions in tap water and various binary mixtures with quantitative results.

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

    International Nuclear Information System (INIS)

    Singh, Ashok K.; Singh, Prerna; Banerjee, Shibdas; Mehtab, Sameena

    2009-01-01

    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 (L 1 ) 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 (L 2 ) 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 L 1 : PVC:1-CN:NaTPB in the ratio of 6: 32: 58: 4 (w/w; mg). The performance of the membrane based on L 1 was compared with polymeric membrane electrode (PME) as well as with coated graphite electrode (CGE). The electrodes exhibit Nernstian slope for Tb 3+ 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 months. The CGE was used as indicator electrode in the potentiometric titration of Tb 3+ ions with EDTA and in determination of fluoride ions in various samples. It can also be used in direct determination of Tb 3+ ions in tap water and various binary mixtures with quantitative results

  7. Non-contacting "snubber bearing" for passive magnetic bearing systems

    Science.gov (United States)

    Post, Richard F

    2017-08-22

    A new non-contacting magnetic "snubber" bearing is provided for application to rotating systems such as vehicular electromechanical battery systems subject to frequent accelerations. The design is such that in the equilibrium position the drag force of the snubber is very small (milliwatts). However in a typical case, if the rotor is displaced by as little as 2 millimeters a large restoring force is generated without any physical contact between the stationary and rotating parts of the snubber bearing.

  8. Bears, Big and Little. Young Discovery Library Series.

    Science.gov (United States)

    Pfeffer, Pierre

    This book is written for children 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume describes: (1) the eight species of bears, including black bear, brown bear, grizzly bear, spectacled bear, sun bear, sloth bear, polar bear, and giant panda; (2) geographical habitats of bears; (3)…

  9. Molecular recognition of chromophore molecules to amine terminated surfaces

    International Nuclear Information System (INIS)

    Flores-Perez, Rosangelly; Ivanisevic, Albena

    2007-01-01

    We report the design and characterization of quartz surfaces that can bind to three retinal based chromophores. The amine terminated surfaces were engineered in order to mimic the environment of the opsin protein that accommodates binding of chromophore molecules in the human eye. Each surface coupling step was characterized by water contact angle measurements, ellipsometry, atomic force microscopy, X-ray photoelectron spectroscopy, and transmission infrared spectroscopy. The spectroscopic techniques confirmed that the three chromophore molecules can bind to the surface using a Schiff base mode. Our data suggests that the availability of the amine groups on the surface is critical in the accommodation of the binding of different chromophores

  10. Determination of Biogenic Amines in Different Shrimp Species for Export

    International Nuclear Information System (INIS)

    Myat Myat Thaw; Oo Aung; Aung Myint; Bisswanger, Hans

    2004-06-01

    This study is part of the project on the ''Quality Assurance of Different Shrimp Species for Export''. Local shrimp samples were collected from Ministry of Livestock and Fisheries and various private enterprises. Contents of biogenic amines were determined by using benzoyl chloride derivatization method with HPLC (reverse phase high performance liquid chromatography). Based on the biogenic amines, quality index of shrimps were correlated with freshness index so that the grade of shrimp samples can be classified as excellent, good, and acceptable. All sizes of shrimps such as extra large, large, medium were found to excceptable respectively

  11. Mesoporous amine-bridged polysilsesquioxane for CO2 capture

    KAUST Repository

    Qi, Genggeng

    2011-01-01

    A novel class of amine-supported sorbents based on amine-bridged mesoporous polysilsesquioxane was developed via a simple one-pot sol-gel process. The new sorbent allows the incorporation of a large amount of active groups without sacrificing surface area or pore volume available for CO2 capture, leading to a CO2 capture capacity of 3.2 mmol g−1 under simulated flue gas conditions. The sorbent is readily regenerated at 100°C and exhibits good stability over repetitive adsorption-desorption cycling.

  12. A Catalyst-Free Amination of Functional Organolithium Reagents by Flow Chemistry.

    Science.gov (United States)

    Kim, Heejin; Yonekura, Yuya; Yoshida, Jun-Ichi

    2018-04-03

    Reported is the electrophilic amination of functional organolithium intermediates with well-designed aminating reagents under mild reaction conditions using flow microreactors. The aminating reagents were optimized to achieve efficient C-N bond formation without using any catalyst. The electrophilic amination reactions of functionalized aryllithiums were successfully conducted under mild reaction conditions, within 1 minute, by using flow microreactors. The aminating reagent was also prepared by the flow method. Based on stopped-flow NMR analysis, the reaction time for the preparation of the aminating reagent was quickly optimized without the necessity of work-up. Integrated one-flow synthesis consisting of the generation of an aryllithium, the preparation of an aminating reagent, and their combined reaction was successfully achieved to give the desired amine within 5 minutes of total reaction time. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Monomers for thermosetting and toughening epoxy resins. [glycidyl amine derivatives, propargyl-containing amines, and mutagenic testing of aromatic diamines

    Science.gov (United States)

    Pratt, J. R.

    1981-01-01

    Eight glycidyl amines were prepared by alkylating the parent amine with epichlorohydrin to form chlorohydrin, followed by cyclization with aqueous NaOH. Three of these compounds contained propargyl groups with postcuring studies. A procedure for quantitatively estimating the epoxy content of these glycidyl amines was employed for purity determination. Two diamond carbonates and several model propargly compounds were prepared. The synthesis of three new diamines, two which contain propargyloxy groups, and another with a sec-butyl group is in progress. These materials are at the dinitro stage ready for the final hydrogenation step. Four aromatic diamines were synthesized for mutagenic testing purposes. One of these compounds rapidly decomposes on exposure to air.

  14. Water-bearing explosive compositions

    Energy Technology Data Exchange (ETDEWEB)

    Gay, G M

    1970-12-21

    An explosive water-bearing composition, with high detonation velocity, comprises a mixture of (1) an inorganic oxidizer salt; (2) nitroglycerine; (3) nitrocellulose; (4) water; and (5) a water thickening agent. (11 claims)

  15. A protocol for amide bond formation with electron deficient amines and sterically hindered substrates

    DEFF Research Database (Denmark)

    Due-Hansen, Maria E; Pandey, Sunil K; Christiansen, Elisabeth

    2016-01-01

    A protocol for amide coupling by in situ formation of acyl fluorides and reaction with amines at elevated temperature has been developed and found to be efficient for coupling of sterically hindered substrates and electron deficient amines where standard methods failed.......A protocol for amide coupling by in situ formation of acyl fluorides and reaction with amines at elevated temperature has been developed and found to be efficient for coupling of sterically hindered substrates and electron deficient amines where standard methods failed....

  16. Failure analysis of superconducting bearings

    Energy Technology Data Exchange (ETDEWEB)

    Rastogi, Amit; Campbell, A M; Coombs, T A [Department of Engineering, University of Cambridge, Cambridge CB2 1PZ (United Kingdom)

    2006-06-01

    The dynamics of superconductor bearings in a cryogenic failure scenario have been analyzed. As the superconductor warms up, the rotor goes through multiple resonance frequencies, begins to slow down and finally touches down when the superconductor goes through its transition temperature. The bearing can be modelled as a system of springs with axial, radial and cross stiffness. These springs go through various resonant modes as the temperature of the superconductor begins to rise. We have presented possible explanations for such behavio0008.

  17. Superconducting composite for magnetic bearings

    International Nuclear Information System (INIS)

    Rigney, T.K. II.

    1995-01-01

    A composite includes granules of Type II superconducting material and granules of rare-earth permanent magnets that are distributed in a binder. The composite is a two-phase structure that combines the properties of the superconductor and magnets with the flexibility and toughness of a polymeric material. A bearing made from this composite has the load capacity and stiffness of a permanent magnet bearing with added stability from a Type II superconducting material. 7 figs

  18. The geochronology of uranium deposits in the Great Bear batholith, Northwest Territories

    International Nuclear Information System (INIS)

    Miller, R.G.

    1982-01-01

    The oldest uranium mineralisation found in the Great Bear batholith during this study may be hydrothermal pitchblende-hematite veins at Hottah Lake. Their apparent age of 2058 +- 34 Ma can also be explained by the contamination of deposits only 440 +- 57 Ma old, which is the age of pitchblende veins nearby. Numerous pendants of metamorphosed, uraninite-bearing 'black sand' placers in a north-trending belt west of the Wopmay Fault are 1860 +- 20 Ma old, the age of the granites that intrude them. Mineralisation at Echo Bay is from 1500 +- 10 to 1424 +- 29 Ma old, and extends up to 30 km north and 40 km south of Echo Bay. The JD claims contain small quartz vein deposits dated at 535 +- 164 and 1092 +- 115 Ma. At Mountain Lake, pitchblende in Helikian sandstones overlying the batholith is 1076 +- 96 Ma old. Polymetallic veinlets at Mazenod Lake are 457 +- 26 Ma old. Pitchblende in a giant quartz vein at the Rayrock mine is 511 +- 86 Ma old. Small pitchblende veins east of the batholith along the Coppermine River are between 400 and 660 Ma old. All the deposits are either between approximately 395 and 660 Ma old, or indicate remobilization during this interval. These events may be related to a marine transgression and regression approximately 600 and 350 Ma ago, respectively

  19. Thermal properties of wood reacted with a phosphorus pentoxide–amine system

    Science.gov (United States)

    Hong-Lin Lee; George C. Chen; Roger M. Rowell

    2004-01-01

    The objective of this research was to improve the fire-retardant properties of wood in one treatment using a phosphorus pentoxide–amine system. Phosphorus pentoxide and 16 amines including alkyl, halophenyl, and phenyl amines were compounded in N,N-dimethylformamide and the resulting solutions containing phosphoramides were reacted with wood. The characteristics of...

  20. Copper(II)-catalyzed electrophilic amination of quinoline N-oxides with O-benzoyl hydroxylamines.

    Science.gov (United States)

    Li, Gang; Jia, Chunqi; Sun, Kai; Lv, Yunhe; Zhao, Feng; Zhou, Kexiao; Wu, Hankui

    2015-03-21

    Copper acetate-catalyzed C-H bond functionalization amination of quinoline N-oxides was achieved using O-benzoyl hydroxylamine as an electrophilic amination reagent, thereby affording the desired products in moderate to excellent yields. Electrophilic amination can also be performed in good yield on a gram scale.

  1. Blue Chitin columns for the extraction of heterocyclic amines from urine samples

    DEFF Research Database (Denmark)

    Bang, J.; Frandsen, Henrik Lauritz; Skog, K.

    2004-01-01

    During normal cooking of meat, a class of mutagenic/carcinogenic compounds called heterocyclic amines is formed. Heterocyclic amines are rapidly absorbed and metabolised in the human body, and for estimation of the intake of heterocyclic amines, it is useful to determinate their levels in the uri...

  2. 40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid amine condensate... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts. (a... a fatty acid amine condensate, polycarboxylic acid salts. (PMN P-92-445) is subject to reporting...

  3. METALCOMPLEXES OF TELLURIUM-CONTAINING AMINES AND AZOMETINES

    Directory of Open Access Journals (Sweden)

    G. M. Abakarov

    2014-01-01

    Full Text Available In this article methods of synthesis and reactionary ability of metalcomplexes of tellurium-containing amines, azometines, of a problem of competitive coordination with use of the principle of "soft" and "rigid" acids and the bases (R. Pearson.

  4. Cloud condensation nuclei activity of aliphatic amine secondary aerosol

    Science.gov (United States)

    Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical). The resulting particle composition can contain both secondary organic aerosol (SOA) and inorganic salts. The fraction of organic to inorganic materials in the particulate ...

  5. Cytocompatibility of amine functionalized carbon nanoparticles grafted on polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Žáková, Pavlína, E-mail: pavlina.zakova@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Slepičková Kasálková, Nikola [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Kolská, Zdeňka [Faculty of Science, J. E. Purkyně University, Ústí nad Labem (Czech Republic); Leitner, Jindřich [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Karpíšková, Jana; Stibor, Ivan [Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec (Czech Republic); Slepička, Petr; Švorčík, Václav [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic)

    2016-03-01

    Five types of amide–amine Carbon Nano-Particles (CNPs) were prepared by functionalization of CNPs and characterized by several analytical methods. The successful grafting of amines on CNPs was verified by X-ray photoelectron spectroscopy (XPS), organic elemental analysis and electrokinetic analysis. The size and morphology of CNPs were determined from transmission electron microscopy. The surface area and porosity of CNPs were examined by adsorption and desorption isotherms. Differential scanning calorimetry was used to investigate thermal stability of CNPs. The amount of bonded amine depends on its dimensionality arrangement. Surface area and pore volumes of CNPs decrease several times after individual amino-compound grafting. Selected types of functionalized CNPs were grafted onto a plasma activated surface of HDPE. The successful grafting of CNPs on the polymer surface was verified by XPS. Wettability was determined by contact angle measurements. Surface morphology and roughness were studied by atomic force microscopy. A dramatic decrease of contact angle and surface morphology was observed on CNP grafted polymer surface. Cytocompatibility of modified surfaces was studied in vitro, by determination of adhesion, proliferation and viability of vascular smooth muscle cells (VSMCs). Grafting of CNPs onto the polymer surface has a positive effect on the adhesion, proliferation and viability of VSMCs. - Highlights: • Amine functionalized CNPs were successfully grafted on HDPE surface. • Significant change to the positive zeta potential for grafted CNPs was induced. • Grafting of CNPs significantly enhanced cell cytocompatibility and viability. • Homogeneous distribution of cells with correct size was achieved.

  6. Effects of amine fluoride on biofilm growth and salivary pellicles

    NARCIS (Netherlands)

    Van der Mei, HC; Engels, E; de Vries, Jacob; Busscher, HJ

    2008-01-01

    The amine fluoride (AmF) N'-octadecyltrimethylendiamine-N, N,N'-tris(2-ethanol)-dihydrofluoride is a cationic antimicrobial which can have beneficial effects on plaque formation. Here, we determine changes in pellicle and bacterial cell surface properties of the strains Actinomyces naeslundii HM1,

  7. 40 CFR 721.6140 - Dialkyldithiophosphoric acid, aliphatic amine salt.

    Science.gov (United States)

    2010-07-01

    ... methods for protecting against such risk, into an MSDS as described in § 721.72(c) within 90 days from the..., aliphatic amine salt. 721.6140 Section 721.6140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... manner or method of manufacture, import, or processing associated with any use of this substance without...

  8. Efficient acetylation of primary amines and amino acids in ...

    Indian Academy of Sciences (India)

    This effort represents the first efficient use of this most reactive but cheap acetylating agent to acetylate amines in excellent yields in aqueous medium. This is a potentially useful green chemical transformation where reaction takes place in environment-friendly brine solution leading to easy work-up and isolation of the ...

  9. Electrochemical degradation of aromatic amines on BDD electrodes

    International Nuclear Information System (INIS)

    Pacheco, M.J.; Santos, V.; Ciriaco, L.; Lopes, A.

    2011-01-01

    The electrochemical oxidation of four aromatic amines, with different substituent groups, 3-amino-4-hydroxy-5-nitrobenzenesulfonic acid (A1), 5-amino-2-methoxybenzenesulfonic acid (A2), 2,4-dihydroxyaniline hydrochloride (A3) and benzene-1,4-diamine (A4), was performed using as anode a boron-doped diamond electrode, commercially available at Adamant Technologies. Tests were run at room temperature with model solutions of the different amines, with concentrations of 200 ppm, using as electrolyte 0.035 M Na 2 SO 4 aqueous solutions, in a batch cell with recirculation, at different current densities (200 and 300 A m -2 ). The following analyses were performed with the samples collected during the assays: UV-Vis spectrophotometry, chemical oxygen demand (COD), total organic carbon (TOC), total Kjeldahl nitrogen, ammonia nitrogen, nitrates and HPLC. Results have shown a good electrodegradation of all the amines tested, with COD removals, after 6 h assays, higher than 90% and TOC removals between 60 and 80%. Combustion efficiency (η C ), which measures the tendency to convert organic carbon to CO 2 , was also determined for all the amines, being η CA1 CA2 CA3 CA4 = 0.99.

  10. Electrodeposition of amine-terminatedpoly(ethylene glycol) to titanium surface

    International Nuclear Information System (INIS)

    Tanaka, Yuta; Doi, Hisashi; Iwasaki, Yasuhiko; Hiromoto, Sachiko; Yoneyama, Takayuki; Asami, Katsuhiko; Imai, Hachiro; Hanawa, Takao

    2007-01-01

    The immobilization of poly(ethylene glycol), PEG, to a solid surface is useful to functionalize the surface, e.g., to prevent the adsorption of proteins. No successful one-stage technique for the immobilization of PEG to base metals has ever been developed. In this study, PEG in which both terminals or one terminal had been modified with amine bases was immobilized onto a titanium surface using electrodeposition. PEG was dissolved in a NaCl solution, and electrodeposition was carried out at 310 K with - 5 V for 300 min. The thickness of the deposited PEG layer was evaluated using ellipsometry, and the bonding manner of PEG to the titanium surface was characterized using X-ray photoelectron spectroscopy after electrodeposition. The results indicated that a certain amount of PEG was adsorbed on titanium through both electrodeposition and immersion when PEG was terminated by amine. However, terminated amines existed at the surface of titanium and were combined with titanium oxide as N-HO by electrodeposition, while amines randomly existed in the molecule and showed an ionic bond with titanium oxide by immersion. The electrodeposition of PEG was effective for the inhibition of albumin adsorption. This process is useful for materials that have electroconductivity and a complex morphology

  11. Enzymatic network for production of ether amines from alcohols

    NARCIS (Netherlands)

    Palacio, Cyntia M.; Crismaru, Gica Ciprian; Bartsch, Sebastian; Navickas, Vaidotas; Ditrich, Klaus; Breuer, Michael; Abu, Rohana; Woodley, John; Baldenius, Kai-Uwe; Wu, Bian; Janssen, Dick

    We constructed an enzymatic network composed of three different enzymes for the synthesis of valuable ether amines. The enzymatic reactions are interconnected to catalyze the oxidation and subsequent transamination of the substrate and to provide cofactor recycling. This allows production of the

  12. Amides and Hydrazides from Amine and Hydrazine Hydrochlorides.

    Science.gov (United States)

    Shama, Sami A.; Tran, Thuan L.

    1978-01-01

    This safe and efficient procedure for the synthesis of N-substituted amides and hydrazides is a modification of the Schotten-Bausmann procedure in which the amine or hydrazide is replaced by the corresponding hydrochloride salt, and the use of alkali is eliminated. (Author/BB)

  13. Hydrothermal synthesis and characterisation of amine-templated ...

    African Journals Online (AJOL)

    Hydrothermal synthesis and characterisation of amine-templated metal phosphate framework. ... The complexes were thermally stable up to 3000C, after which the organic components starts decomposing. The solubility test in a wide spectrum of solvents (at room temperature) showed that the complexes were insoluble in ...

  14. Products of tungstate ion interaction with primary aliphatic amines

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Sejfullina, I.I.; Purich, A.N.; Babinets, S.K.

    1982-01-01

    Using the methods of conductometric titration, IR-spectroscopic and thermographic analyses precipitates formed in the process of interaction of diluted aqueous solutions of sodium tungstate with alcoholic solutions of dodecyl-, tetradecyl- and octadecylamine have been studied. It is shown that as a result of interaction tungstates of corresponding amines are formed. The structure and thermal stability of singled out products are determined

  15. Understanding the political economy of contemporary Africa | Amin ...

    African Journals Online (AJOL)

    Further readings, offering a critique of 'post modernist' sociology and cultural studies (see, for instance, Samir Amin, The Liberal Virus, Pluto 2004, pages 19 et seq.) complete the picture of the ongoing intellectual disaster. CODESRIA constitutes an important intellectual locus conducting real open debates with a strong ...

  16. Maillard reaction of lactose and fluoxetine hydrochloride, a secondary amine.

    Science.gov (United States)

    Wirth, D D; Baertschi, S W; Johnson, R A; Maple, S R; Miller, M S; Hallenbeck, D K; Gregg, S M

    1998-01-01

    Analysis of commercially available generic formulations of fluoxetine HCl revealed the presence of lactose as the most common excipient. We show that such formulations are inherently less stable than formulations with starch as the diluent due to the Maillard reaction between the drug, a secondary amine hydrochloride, and lactose. The Amadori rearrangement product was isolated and characterized; the characterization was aided by reduction with sodium borohydride and subsequent characterization of this reduced adduct. The lactose-fluoxetine HCl reaction was examined in aqueous ethanol and in the solid state, in which factors such as water content, lubricant concentration, and temperature were found to influence the degradation. N-Formylfluoxetine was identified as a major product of this Maillard reaction and it is proposed that N-formyl compounds be used as markers for this drug-excipient interaction since they are easy to prepare synthetically. Many characteristic volatile products of the Maillard reaction have been identified by GC/MS, including furaldehyde, maltol, and 2,3-dihydro-3,5-dihydroxy-6-methyl-4 H-pyran-4-one. Close similarity between the degradation products of simple mixtures and formulated generic products was found; however, at least one product decomposed at a rate nearly 10 times that predicted from the simple models. Maillard products have also been identified in unstressed capsules. The main conclusion is that drugs which are secondary amines (not just primary amines as sometimes reported) undergo the Maillard reaction with lactose under pharmaceutically relevant conditions. This finding should be considered during the selection of excipients and stability protocols for drugs which are secondary amines or their salts, just as it currently is for primary amines.

  17. Regularities of synthesis and mechanism of polycondensation of aromatic amines

    International Nuclear Information System (INIS)

    Matnishyan, Hagob

    2002-01-01

    Full text.Aniline polymers and its derivatives are widely used in modern electronics, electrical engineering and manufacturing of various appliances. They are used for production of electrical power sources, probes and sensors, composite materials absorbing high frequency radiations, anticorrosion coatings, nonlinear optical devices-such as lasers, cathode ray tubes, photodiodes etc. Such a wide usage of aromatic amine polymers brings up new demands to their structure and properties, which is dependent on conditions of synthesis and forming of the hard phase. The presented article describes regularities and mechanisms of oxidative polycondensation of aromatic amines. Several types of polymers have been synthesized by chemical and electrochemical oxidation of aniline and its chlor-, brom-, iodo-, nitro-, p-substituted derivatives; diphenylamine, benzidine and phenylenediamines in nonwater media. On the basis of kinetic and electrochemical studies and literature analysis we suggested a mechanism of polycondensation of aromatic amines. According to it, oxidation of amines starts with the electron transfer with cation-radical formation on the first stage, which stabilizes in acid environments due to complex formation with initial amine. Dimer formation and further growth of chain takes place upon another electron transfer from formed complex, which results in forming of macromolecules. We also suggested a scheme for obtaining of structures defect in media assisting in deprotonizing of cation radicals and formation of arylamine radical centers. Those processes lead to formation of azo- and diphenyl fragments in the main chain of the polymer and predetermine the possibility of chain disruption. We also considered reactions leading to formation of branched polymers and cyclic structures, such as phenazine in particular. The peculiarity of electrochemical process lies in regulation of concentration of active centres on the positive electrode surface

  18. Transglutaminase-catalyzed amination of pea protein peptides using the biogenic amines histamine and tyramine.

    Science.gov (United States)

    Lu, Xinyao; Hrynets, Yuliya; Betti, Mirko

    2017-06-01

    Biogenic amines (BAs) are produced by the enzymatic decarboxylation of amino acids, and are well-known for their toxicity to humans. This study describes a new method using microbial transglutaminase (MTGase) to covalently link BAs such as histamine (HIS) and tyramine (TYR) to the glutamine residues of alcalase-hydrolyzed pea protein (PPH). The incubation of PPH and HIS and TYR in the presence of MTGase at 37 °C led to the formation of conjugates, as determined by liquid chromatography, after derivatization with dansyl chloride. Seventy-six % of HIS and 65% of TYR were covalently incorporated to PPH by MTGase. The incubation of PPH and TYR in the presence of MTGase exhibited a 52% DPPH radical scavenging activity at 10 mg mL -1 . Conjugation via MTGase improved the antioxidant status by reducing lipid peroxidation. This study emphasizes that the application of MTGase can effectively reduce histamine and tyramine content while simultaneously enhancing antioxidative capacity of PPH. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. 49 CFR 229.69 - Side bearings.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Side bearings. 229.69 Section 229.69....69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not have more than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in...

  20. Analysis of a Buchwald-Hartwig amination: reaction for pharmaceutical production

    DEFF Research Database (Denmark)

    Christensen, Henrik

    The Buchwald-Hartwig amination reaction is widely used in the production of N-arylated amines in the pharmaceutical industry. The reaction is betweenan aryl halogen and a primary or secondary amine in the presence of a base and a homogeneous catalyst giving the desired N-arylated amine. Due to mild...... is to increase the understanding of the chem­ical reaction mechanisms and kinetics for the Buchwald-Hartwig amination reaction. Also, to develop methods for application of these mechanisms and kinetics to optimize and scale up an organic synthesis to an industrial phar­maceutical production. The Buchwald...

  1. Analysis of a Buckwald-Hartwig amination: reaction for pharmaceutical production

    DEFF Research Database (Denmark)

    Christensen, Henrik; Kiil, Søren; Dam-Johansen, Kim

    The Buchwald-Hartwig amination reaction is widely used in the production of N-arylated amines in the pharmaceutical industry. The reaction is betweenan aryl halogen and a primary or secondary amine in the presence of a base and a homogeneous catalyst giving the desired N-arylated amine. Due to mild...... is to increase the understanding of the chem­ical reaction mechanisms and kinetics for the Buchwald-Hartwig amination reaction. Also, to develop methods for application of these mechanisms and kinetics to optimize and scale up an organic synthesis to an industrial phar­maceutical production. The Buchwald...

  2. Superconductor bearings, flywheels and transportation

    International Nuclear Information System (INIS)

    Werfel, F N; Floegel-Delor, U; Rothfeld, R; Riedel, T; Goebel, B; Wippich, D; Schirrmeister, P

    2012-01-01

    This paper describes the present status of high temperature superconductors (HTS) and of bulk superconducting magnet devices, their use in bearings, in flywheel energy storage systems (FESS) and linear transport magnetic levitation (Maglev) systems. We report and review the concepts of multi-seeded REBCO bulk superconductor fabrication. The multi-grain bulks increase the averaged trapped magnetic flux density up to 40% compared to single-grain assembly in large-scale applications. HTS magnetic bearings with permanent magnet (PM) excitation were studied and scaled up to maximum forces of 10 kN axially and 4.5 kN radially. We examine the technology of the high-gradient magnetic bearing concept and verify it experimentally. A large HTS bearing is tested for stabilizing a 600 kg rotor of a 5 kWh/250 kW flywheel system. The flywheel rotor tests show the requirement for additional damping. Our compact flywheel system is compared with similar HTS–FESS projects. A small-scale compact YBCO bearing with in situ Stirling cryocooler is constructed and investigated for mobile applications. Next we show a successfully developed modular linear Maglev system for magnetic train operation. Each module levitates 0.25t at 10 mm distance during one-day operation without refilling LN 2 . More than 30 vacuum cryostats containing multi-seeded YBCO blocks are fabricated and are tested now in Germany, China and Brazil.

  3. Noise estimation of oil lubricated journal bearings

    International Nuclear Information System (INIS)

    Rho, Byoung Hoo; Kim, Kyung Woong

    2003-01-01

    Noise estimating procedures of oil lubricated journal bearings are presented. Nonlinear analysis of rotor-bearing system including unbalance mass of the rotor is performed in order to obtain acoustical properties of the bearing. Acoustical properties of the bearing are investigated through frequency analysis of the pressure fluctuation of the fluid film calculated from the nonlinear analysis. Noise estimating procedures presented in this paper could aid in the evaluation and understanding of acoustical properties of oil lubricated journal bearings

  4. Factors influencing the regioselectivity of the oxidation of asymmetric secondary amines with singlet oxygen.

    Science.gov (United States)

    Ushakov, Dmitry B; Plutschack, Matthew B; Gilmore, Kerry; Seeberger, Peter H

    2015-04-20

    Aerobic amine oxidation is an attractive and elegant process for the α functionalization of amines. However, there are still several mechanistic uncertainties, particularly the factors governing the regioselectivity of the oxidation of asymmetric secondary amines and the oxidation rates of mixed primary amines. Herein, it is reported that singlet-oxygen-mediated oxidation of 1° and 2° amines is sensitive to the strength of the α-C-H bond and steric factors. Estimation of the relative bond dissociation energy by natural bond order analysis or by means of one-bond C-H coupling constants allowed the regioselectivity of secondary amine oxidations to be explained and predicted. In addition, the findings were utilized to synthesize highly regioselective substrates and perform selective amine cross-couplings to produce imines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Changes in plain bearing technology

    CERN Document Server

    Koring, Rolf

    2012-01-01

    A unique fusion of theoretical and practical knowledge, Changes in Plain Bearing Technology, by Rolf Koring, covers a meaningful range of expertise in this field.Drawing from years of experience in design development, materials selection, and their correlation to real-life part failure, this title, co-published by SAE International and expert Verlag (Germany), concentrates on hydrodynamic bearings lined with white metals, also known as Babbits.Written under the assumption that even the most mature body of knowledge can be revisited and improved, Changes in Plain Bearing Technology is a courageous and focused approach to questioning accepted test results and looking at alternative material compounds, and their application suitability.The process, which leads to innovative answers on how the technology is transforming itself to respond to new market requirements, shows how interdisciplinary thinking can recognize new potential in long-established industrial modus operandi.Tackling the highly complex issue of co...

  6. 'Dodo' and 'Baby Bear' Trenches

    Science.gov (United States)

    2008-01-01

    NASA's Phoenix Mars Lander's Surface Stereo Imager took this image on Sol 11 (June 5, 2008), the eleventh day after landing. It shows the trenches dug by Phoenix's Robotic Arm. The trench on the left is informally called 'Dodo' and was dug as a test. The trench on the right is informally called 'Baby Bear.' The sample dug from Baby Bear will be delivered to the Phoenix's Thermal and Evolved-Gas Analyzer, or TEGA. The Baby Bear trench is 9 centimeters (3.1 inches) wide and 4 centimeters (1.6 inches) deep. 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.

  7. Pendant chain engineering to fine-tune the nanomorphologies and solid state luminescence of naphthalimide AIEEgens: application to phenolic nitro-explosive detection in water.

    Science.gov (United States)

    Meher, Niranjan; Iyer, Parameswar Krishnan

    2017-06-08

    Strategically, a series of five angular "V" shaped naphthalimide AIEEgens with varying pendant chains (butyl, hexyl, octyl, cyclohexyl and methylcyclohexyl) have been synthesized to fine-tune their nanomorphological and photophysical properties. With similar aromatic cores and electronic states, unexpected tuning of the condensed state emission colors and nanomorphologies (reproducible on any kind of surface) of naphthalimides has been achieved for the first time simply by varying their side chains. Conclusive analysis by various spectroscopic techniques (SC-XRD, powder-XRD, DLS, FESEM) and DFT computational studies confirmed the full control of the pendant chain (in terms of bulkiness around the naphthalimide core, which restricts the ease of intermolecular π-π interactions) over the nanoaggregate morphology and solid state emissive properties of the AIEEgens; this can be rationalized to all aggregation-prone systems. These comprehensive studies establish a conceptually unique yet simple and effective method to precisely tune the nanomorphologies and the emission colors of aggregation-prone small organic molecules by judicious choice of the non-conjugated pendant chain. Thus, considering the prime role of the active layer nanomorphology in all organic optoelectronic devices, this methodology may emerge as a promising tool to improve device performance. Among all the congeners, the hexyl chain-containing congener (HNQ) forms well-defined nanoribbons with smaller diameters (as confirmed from DLS: 166 nm and FESEM: 150 nm) and provides a larger surface area. Consequently, the HNQ-nanoribbons were employed as a fluorescent sensor for the discriminative detection of trinitrophenol (TNP) in pure aqueous media. FE-SEM images revealed that, upon gradual addition of TNP (10 nM to 100 μM), these nanoribbons undergo an aggregation/disaggregation process, forming non-fluorescent co-aggregates with TNP, and provide highly enhanced sensitivity compared to existing state

  8. Oxidations of N-(3-indoleethyl) cyclic aliphatic amines by horseradish peroxidase: the indole ring binds to the enzyme and mediates electron-transfer amine oxidation.

    Science.gov (United States)

    Ling, Ke-Qing; Li, Wen-Shan; Sayre, Lawrence M

    2008-01-23

    Although oxidations of aromatic amines by horseradish peroxidase (HRP) are well-known, typical aliphatic amines are not substrates of HRP. In this study, the reactions of N-benzyl and N-methyl cyclic amines with HRP were found to be slow, but reactions of N-(3-indoleethyl) cyclic amines were 2-3 orders of magnitude faster. Analyses of pH-rate profiles revealed a dominant contribution to reaction by the amine-free base forms, the only species found to bind to the enzyme. A metabolic study on a family of congeneric N-(3-indoleethyl) cyclic amines indicated competition between amine and indole oxidation pathways. Amine oxidation dominated for the seven- and eight-membered azacycles, where ring size supports the change in hybridization from sp3 to sp2 that occurs upon one-electron amine nitrogen oxidation, whereas only indole oxidation was observed for the six-membered ring congener. Optical difference spectroscopic binding data and computational docking simulations suggest that all the arylalkylamine substrates bind to the enzyme through their aromatic termini with similar binding modes and binding affinities. Kinetic saturation was observed for a particularly soluble substrate, consistent with an obligatory role of an enzyme-substrate complexation preceding electron transfer. The significant rate enhancements seen for the indoleethylamine substrates suggest the ability of the bound indole ring to mediate what amounts to medium long-range electron-transfer oxidation of the tertiary amine center by the HRP oxidants. This is the first systematic investigation to document aliphatic amine oxidation by HRP at rates consistent with normal metabolic turnover, and the demonstration that this is facilitated by an auxiliary electron-rich aromatic ring.

  9. Debromination of endo-(+)-3-bromocamphor with primary amines

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, Svetlana; Markovic, Violeta; Joksovic, Milan D.; Joksovic, Ljubinka, E-mail: ljubinka@kg.ac.rs [Department of Chemistry, Faculty of Science, University of Kragujevac (Serbia); Todorovic, Nina [Institute for Chemistry, Technology and Metallurgy, Belgrade (Serbia); Divjakovic, Vladimir [Department of Physics, University of Novi Sad (Serbia); Trifunovic, Snezana [Faculty of Chemistry, University of Belgrade, Belgrade, (Serbia)

    2013-07-15

    Reductive debromination of endo-(+)-3-bromocamphor with different primary amines followed by imine formation was investigated. This reaction requires simple experimental procedure without any organic solvent, metal or conventional reducing agent. A strong influence of amine polarity on the efficacy of debromination process was observed, and ethanolamine and ethylene diamine having sufficiently high boiling points can debrominate 3-bromocamphor giving corresponding camphanimines in good isolated yields. The mechanisms of debromination of 3-bromocamphor with ethanolamine and n-hexylamine were investigated at the B3LYP/6-311+G(d,p) level of theory. The radical mechanism was revealed, and it was shown that the reaction with more polar ethanolamine is energetically more favorable. (author)

  10. Nanoscale assembly of amine-functionalized colloidal iron oxide

    Energy Technology Data Exchange (ETDEWEB)

    Barick, K.C. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076 (India); Aslam, M. [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Centre for Research in Nanotechnology and Science, Indian Institute of Technology Bombay, Mumbai 400076 (India); Prasad, Pottumarthi V. [Department of Radiology, Evanston Northwestern Healthcare, Evanston, IL 60201 (United States); Dravid, Vinayak P. [Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208 (United States)], E-mail: v-dravid@northwestern.edu; Bahadur, Dhirendra [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076 (India); Centre for Research in Nanotechnology and Science, Indian Institute of Technology Bombay, Mumbai 400076 (India)], E-mail: dhirenb@iitb.ac.in

    2009-05-15

    We demonstrate a single-step facile approach for highly water-stable assembly of amine-functionalized Fe{sub 3}O{sub 4} nanoparticles using thermal decomposition of Fe-chloride precursors in ethylene glycol medium in the presence of ethylenediamine. The average size of nanoassemblies is 40{+-}1 nm, wherein the individual nanoparticles are about 6 nm. Amine-functionalized properties are evident from Fourier transform infrared spectrometer (FTIR), thermal and elemental analyses. The saturation magnetization and spin-echo r{sub 2} of the nanoassemblies were measured to be 64.3 emu/g and 314.6 mM{sup -1} s{sup -1}, respectively. The higher value of relaxivity ratio (r{sub 2}/r{sub 1}=143) indicates that nanoassemblies are a promising high-efficiency T2 contrast agent platform.

  11. Nanoscale assembly of amine-functionalized colloidal iron oxide

    International Nuclear Information System (INIS)

    Barick, K.C.; Aslam, M.; Prasad, Pottumarthi V.; Dravid, Vinayak P.; Bahadur, Dhirendra

    2009-01-01

    We demonstrate a single-step facile approach for highly water-stable assembly of amine-functionalized Fe 3 O 4 nanoparticles using thermal decomposition of Fe-chloride precursors in ethylene glycol medium in the presence of ethylenediamine. The average size of nanoassemblies is 40±1 nm, wherein the individual nanoparticles are about 6 nm. Amine-functionalized properties are evident from Fourier transform infrared spectrometer (FTIR), thermal and elemental analyses. The saturation magnetization and spin-echo r 2 of the nanoassemblies were measured to be 64.3 emu/g and 314.6 mM -1 s -1 , respectively. The higher value of relaxivity ratio (r 2 /r 1 =143) indicates that nanoassemblies are a promising high-efficiency T2 contrast agent platform.

  12. Structural Influence on Excited State Dynamics in Simple Amines

    DEFF Research Database (Denmark)

    Klein, Liv Bærenholdt

    experiments with calculations, provides new insight into the nature of the internal conversion processes that mediate the dynamical evolution between Rydberg states, and how structural variations in simple amine system have a large impact on the non-adiabatic processes. The experimental method of choice...... is femtosecond time-resolved photoelectron velocity map imaging (VMI), which is a newtechnique in the Copenhagen lab. The design, building and implementation of the VMI spectrometer has been a very substantial part of the thesis work. This techniques oers enhanced information content in the form of ecient...... and sensitive collection of photoelectron spectra. In particular, the angleresolved data available from the VMI approach provides highly detailed mechanistic insight about the relaxation pathways. One striking novel nding is that for tertiary amines, the critical factor driving the non-adiabatic dynamics...

  13. Extraction of beryllium sulfate by a long chain amine

    International Nuclear Information System (INIS)

    Etaix, E.S.

    1968-01-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [fr

  14. Berkelium (4) and cerium (4) extraction with tertiary amines

    International Nuclear Information System (INIS)

    Milyukova, M.S.; Malikov, D.A.; Myasoedov, B.V.

    1978-01-01

    Oxidation of indicator quantities of berkelium and cerium by a mixture of silver nitrate and ammonium persulfate in the solutions of nitric and sulfuric acid has been examined. The stability of the elements in a tetravalent state and their extraction by the solutions of ternary amines have been investigated. It has been established that berkelium and cerium oxidation under these conditions occurs under the effect of ions of divalent silver which is formed owing to oxidation of monovalent silver by peroxide sulfate ions. The following supposition has been put forward: a difference in the behaviour of tetravalent berkelium and cerium during their extraction by ternary amines is explained by their different stability in this state, but not by the formation of complex compounds with nitrate ions

  15. The correct "ball bearings" data.

    Science.gov (United States)

    Caroni, C

    2002-12-01

    The famous data on fatigue failure times of ball bearings have been quoted incorrectly from Lieblein and Zelen's original paper. The correct data include censored values, as well as non-fatigue failures that must be handled appropriately. They could be described by a mixture of Weibull distributions, corresponding to different modes of failure.

  16. Little Bear Fire Summary Report

    Science.gov (United States)

    Sarah McCaffrey; Melanie Stidham; Hannah. Brenkert-Smith

    2013-01-01

    In June 2012, immediately after the Little Bear Fire burned outside Ruidoso, New Mexico, a team of researchers interviewed fire managers, local personnel, and residents to understand perceptions of the event itself, communication, evacuation, and pre-fire preparedness. The intensity of fire behavior and resulting loss of 242 homes made this a complex fire with a...

  17. Satellite monitoring of black bear.

    Science.gov (United States)

    Craighead, J. J.; Craighead, F. C., Jr.; Varney, J. R.; Cote, C. E.

    1971-01-01

    Description of a feasibility experiment recently performed to test the use of a satellite system for telemetering environmental and physiological data from the winter den of a 'hibernating' black bear, Ursus americanus. The instrumentation procedure and evaluations of the equipment performance and sensory data obtained are discussed in detail.

  18. Genomic evidence of geographically widespread effect of gene flow from polar bears into brown bears

    OpenAIRE

    Cahill, James A; Stirling, Ian; Kistler, Logan; Salamzade, Rauf; Ersmark, Erik; Fulton, Tara L; Stiller, Mathias; Green, Richard E; Shapiro, Beth

    2015-01-01

    © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd. Polar bears are an arctic, marine adapted species that is closely related to brown bears. Genome analyses have shown that polar bears are distinct and genetically homogeneous in comparison to brown bears. However, these analyses have also revealed a remarkable episode of polar bear gene flow into the population of brown bears that colonized the Admiralty, Baranof and Chichagof islands (ABC islands) of Alaska. Here, we...

  19. Electrophysiological effects of trace amines on mesencephalic dopaminergic neurons

    Directory of Open Access Journals (Sweden)

    Ada eLedonne

    2011-07-01

    Full Text Available Trace amines (TAs are a class of endogenous compounds strictly related to classic monoamine neurotransmitters with regard to their structure, metabolism and tissue distribution. Although the presence of TAs in mammalian brain has been recognized for decades, until recently they were considered to be by-products of amino acid metabolism or as ‘false’ neurotransmitters. The discovery in 2001 of a new family of G protein-coupled receptors (GPCRs, namely trace amines receptors, has re-ignited interest in TAs. In particular, two members of the family, trace amine receptor 1 (TA1 and trace amine receptor 2 (TA2, were shown to be highly sensitive to these endogenous compounds. Experimental evidence suggests that TAs modulate the activity of catecholaminergic neurons and that TA dysregulation may contribute to neuropsychiatric disorders, including schizophrenia, attention deficit hyperactivity disorder, depression and Parkinson’s disease, all of which are characterised by altered monoaminergic networks. Here we review recent data concerning the electrophysiological effects of TAs on the activity of mesencephalic dopaminergic neurons. In the context of recent data obtained with TA1 receptor knockout mice, we also discuss the mechanisms by which the activation of these receptors modulates the activity of these neurons. Three important new aspects of TAs action have recently emerged: (a inhibition of firing due to increased release of dopamine; (b reduction of D2 and GABAB receptor-mediated inhibitory responses (excitatory effects due to dysinhibition; and (c a direct TA1 receptor-mediated activation of GIRK channels which produce cell membrane hyperpolarization. While the first two effects have been well documented in our laboratory, the direct activation of GIRK channels by TA1 receptors has been reported by others, but has not been seen in our laboratory (Geracitano et al., 2004. Further research is needed to address this point, and to further

  20. Biotinylated dextran amine anterograde tracing of the canine corticospinal tract?

    OpenAIRE

    Han, Xiao; Lv, Guangming; Wu, Huiqun; Ji, Dafeng; Sun, Zhou; Li, Yaofu; Tang, Lemin

    2012-01-01

    In this study, biotinylated dextran amine (BDA) was microinjected into the left cortical motor area of the canine brain. Fluorescence microscopy results showed that a large amount of BDA-labeled pyramidal cells were visible in the left cortical motor area after injection. In the left medulla oblongata, the BDA-labeled corticospinal tract was evenly distributed, with green fluorescence that had a clear boundary with the surrounding tissue. The BDA-positive corticospinal tract entered into the ...

  1. Amides derived from heteroaromatic amines and selected steryl hemiesters

    Czech Academy of Sciences Publication Activity Database

    Bildziukevich, Uladzimir; Rárová, L.; Šaman, David; Havlíček, Libor; Drašar, P.; Wimmer, Zdeněk

    2013-01-01

    Roč. 78, č. 14 (2013), s. 1347-1352 ISSN 0039-128X R&D Projects: GA ČR(CZ) GAP503/11/0616 Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional support: RVO:61389030 ; RVO:61388963 Keywords : Heteroaromatic amine * Cholesterol * Lanosterol Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 2.716, year: 2013

  2. OXIDATION OF CYCLIC AMINES BY MOLYBDENUM(II) AND ...

    African Journals Online (AJOL)

    Preferred Customer

    metal is in formal oxidation state +2. Since no reduction can take place without oxidation and vice versa, we can reasonably say the reduction of Mo(II) and W(II) species is accompanied by oxidation of the amine. At this juncture, we should point out that C=N bonds are also known to absorb IR radiation in the same spectral ...

  3. Thermoresponsive Poly(2-oxazoline) Molecular Brushes by Living Ionic Polymerization: Kinetic Investigations of Pendant Chain Grafting and Cloud Point Modulation by Backbone and Side Chain Length Variation

    KAUST Repository

    Zhang, Ning

    2012-04-17

    Molecular brushes of poly(2-oxazoline)s were prepared by living anionic polymerization of 2-iso-propenyl-2-oxazoline to form the backbone and subsequent living cationic ring-opening polymerization of 2-n- or 2-iso-propyl-2-oxazoline for pendant chain grafting. In situ kinetic studies indicate that the initiation efficiency and polymerization rates are independent from the number of initiator functions per initiator molecule. This was attributed to the high efficiency of oxazolinium salt and the stretched conformation of the backbone, which is caused by the electrostatic repulsion of the oxazolinium moieties along the macroinitiator. The resulting molecular brushes showed thermoresponsive properties, that is, having a defined cloud point (CP). The dependence of the CP as a function of backbone and side chain length as well as concentration was studied. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Dicationic and zwitterionic catalysts for the amine-initiated, immortal ring-opening polymerisation of rac-lactide: facile synthesis of amine-terminated, highly heterotactic PLA

    NARCIS (Netherlands)

    Clark, L.; Cushion, M.G.; Dyer, H.E.; Schwarz, A.D.; Duchateau, R.; Mountford, P.

    2010-01-01

    Dicationic, zwitterionic and conventional yttrium compounds act as catalysts for the primary or secondary amine-initiated immortal ROP of rac-lactide; amine-terminated, highly heterotactic poly(rac-lactides) with narrow polydispersities and well-controlled molecular weights are prepared in this

  5. TOOL ASSEMBLY WITH BI-DIRECTIONAL BEARING

    Science.gov (United States)

    Longhurst, G.E.

    1961-07-11

    A two-direction motion bearing which is incorporated in a refueling nuclear fuel element trsnsfer tool assembly is described. A plurality of bi- directional bearing assembliesare fixed equi-distantly about the circumference of the transfer tool assembly to provide the tool assembly with a bearing surface- for both axial and rotational motion. Each bi-directional bearing assembly contains a plurality of circumferentially bulged rollers mounted in a unique arrangement which will provide a bearing surface for rotational movement of the tool assembly within a bore. The bi-direc tional bearing assembly itself is capable of rational motion and thus provides for longitudinal movement of the tool assembly.

  6. Estimating Wear Of Installed Ball Bearings

    Science.gov (United States)

    Keba, John E.; Mcvey, Scott E.

    1993-01-01

    Simple inspection and measurement technique makes possible to estimate wear of balls in ball bearing, without removing bearing from shaft on which installed. To perform measurement, one observes bearing cage while turning shaft by hand to obtain integral number of cage rotations and to measure, to nearest 2 degrees, number of shaft rotations producing cage rotations. Ratio between numbers of cages and shaft rotations depends only on internal geometry of bearing and applied load. Changes in turns ratio reflect changes in internal geometry of bearing provided measurements made with similar bearing loads. By assuming all wear occurs on balls, one computes effective value for this wear from change in turns ratio.

  7. Metabolism and genotoxicity of aromatic amines in aquatic organisms

    International Nuclear Information System (INIS)

    Knezovich, J.P.; Krauter, P.W.; Lawton, M.P.; Harrison, F.L.

    1987-01-01

    Marine mussels (Mytilus edulis) and bullfrog tadpoles (Rana catesbeiana) were used to investigate the comparative metabolism and genotoxicity of aromatic amines in vivo. These organisms were selected because they possess distinctly different metabolic capabilities: mussels lack an active mixed-function-oxidase enzyme system that is present in most other organisms, including amphibians. Using 14 C-labeled chemical probes (o- and p-toluidine, 2-aminofluorene (2-AF), and 2-acetylaminofluorene (2-AAF)), mussels and tadpoles well dosed with individual compounds by direct immersion in aqueous solutions. The identities of metabolites were then determined by HPLC and GC/MS methods. Results indicate that the N-conjugating pathways used by mussels result primarily in the detoxification of aromatic amines by limiting the amount of primary amine available for activation. The tadpoles excreted a number of 2-AAF metabolites but did form DNA and protein adducts in the liver. Induction of micronuclei in the peripheral red blood cells was also demonstrated. The tadpole was shown to be a sensitive biological indicator of pollution in aquatic ecosystems

  8. Role of amine structure on carbon dioxide adsorption from ultradilute gas streams such as ambient air.

    Science.gov (United States)

    Didas, Stephanie A; Kulkarni, Ambarish R; Sholl, David S; Jones, Christopher W

    2012-10-01

    A fundamental study on the adsorption properties of primary, secondary, and tertiary amine materials is used to evaluate what amine type(s) are best suited for ultradilute CO(2) capture applications. A series of comparable materials comprised of primary, secondary, or tertiary amines ligated to a mesoporous silica support via a propyl linker are used to systematically assess the role of amine type. Both CO(2) and water adsorption isotherms are presented for these materials in the range relevant to CO(2) capture from ambient air and it is demonstrated that primary amines are the best candidates for CO(2) capture from air. Primary amines possess both the highest amine efficiency for CO(2) adsorption as well as enhanced water affinity compared to other amine types or the bare silica support. The results suggest that the rational design of amine adsorbents for the extraction of CO(2) from ambient air should focus on adsorbents rich in primary amines. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Concentration, size distribution and dry deposition of amines in atmospheric particles of urban Guangzhou, China

    Science.gov (United States)

    Liu, Fengxian; Bi, Xinhui; Zhang, Guohua; Peng, Long; Lian, Xiufeng; Lu, Huiying; Fu, Yuzhen; Wang, Xinming; Peng, Ping'an; Sheng, Guoying

    2017-12-01

    Size-segregated PM10 samples were collected in Guangzhou, China during autumn of 2014. Nine amines, including seven aliphatic amines and two heterocyclic amines, were detected using a gas chromatography-mass spectrometer after derivatization by benzenesulfonyl chloride. The total concentration of the nine aminesamines) was 79.6-140.9 ng m-3 in PM10. The most abundant species was methylamine (MA), which had a concentration of 29.2-70.1 ng m-3. MA, dimethylamine (DMA), diethylamine (DEA) and dibutylamine (DBA) were the predominant amines in the samples and accounted for approximately 80% of Ʃamines in each size segment. Two heterocyclic amines, pyrrolidine (PYR) and morpholine (MOR), were detected in all samples and had average concentrations of 1.14 ± 0.37 and 1.89 ± 0.64 ng m-3, respectively, in particles with aerodynamic diameters ammonium ranged from 0.0068 to 0.0107 in particles with diameters <1.5 μm, and the maximum ratio occurred in the smallest particles (diameter< 0.49 μm). The average dry deposition flux and velocity of Ʃamines in PM10 were 7.9 ± 1.6 μg m-2 d-1 and 0.084 ± 0.0021 cm s-1, respectively. The results of this study provide essential information on the contribution of amines to secondary organic aerosols and dry removal mechanisms in urban areas.

  10. Redox reactions of Cu(II)-amine complexes in aqueous solutions

    International Nuclear Information System (INIS)

    Kumbhar, A.G.; Kishore, Kamal

    2003-01-01

    A number of amines can be employed for all volatile treatment (AVT) of steam generator (SG) systems of nuclear power reactors. These amines form complexes with Cu 2+ and Ni 2+ ions which come into water due to corrosion. The redox reactions of a number of Cu(II)-AVT amine complexes and the stability of the transient species formed have been studied by pulse radiolysis technique. Rate constants for the reaction of e aq - with a number of Cu(II)-amine complexes have been determined by following the decay of e aq - absorption. Stability of Cu(I)-amine complexes was studied by following the kinetics of the bleaching signal formed at the λ max of the Cu(II) amine complex. Except for Cu(I)-triethanolamine complex all other Cu(I)-amine complexes were found to be stable. One-electron oxidation of Cu(II) amine complexes was studied using azidyl radicals for the oxidation reaction as OH radicals react with the alcohol groups present in the amines used in this study. Cu(III)-amine complexes were found to be unstable and decayed by second-order kinetics

  11. Potential occupational risk of amines in carbon capture for power generation.

    Science.gov (United States)

    Gentry, P Robinan; House-Knight, Tamara; Harris, Angela; Greene, Tracy; Campleman, Sharan

    2014-08-01

    While CO2 capture and storage (CCS) technology has been well studied in terms of its efficacy and cost of implementation, there is limited available data concerning the potential for occupational exposure to amines, mixtures of amines, or degradation of by-products from the CCS process. This paper is a critical review of the available data concerning the potential effects of amines and CCS-degradation by-products. A comprehensive review of the occupational health and safety issues associated with exposure to amines and amine by-products at CCS facilities was performed, along with a review of the regulatory status and guidelines of amines, by-products, and CCS process vapor mixtures. There are no specific guidelines or regulations regarding permissible levels of exposure via air for amines and degradation products that could form atmospheric oxidation of amines released from post-combustion CO2 capture plants. While there has been a worldwide effort to develop legal and regulatory frameworks for CCS, none are directly related to occupational exposures. By-products of alkanolamine degradation may pose the most significant health hazard to workers in CCS facilities, with several aldehydes, amides, nitramines, and nitrosamines classified as either known or potential/possible human carcinogens. The absence of large-scale CCS facilities; absence and unreliability of reported data in the literature from pilot facilities; and proprietary amine blends make it difficult to estimate potential amine exposures and predict formation and exposure to degradation products.

  12. ToF-SIMS analysis of a polymer microarray composed of poly(meth)acrylates with C6 derivative pendant groups.

    Science.gov (United States)

    Hook, Andrew L; Scurr, David J

    2016-04-01

    Surface analysis plays a key role in understanding the function of materials, particularly in biological environments. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides highly surface sensitive chemical information that can readily be acquired over large areas and has, thus, become an important surface analysis tool. However, the information-rich nature of ToF-SIMS complicates the interpretation and comparison of spectra, particularly in cases where multicomponent samples are being assessed. In this study, a method is presented to assess the chemical variance across 16 poly(meth)acrylates. Materials are selected to contain C 6 pendant groups, and ten replicates of each are printed as a polymer microarray. SIMS spectra are acquired for each material with the most intense and unique ions assessed for each material to identify the predominant and distinctive fragmentation pathways within the materials studied. Differentiating acrylate/methacrylate pairs is readily achieved using secondary ions derived from both the polymer backbone and pendant groups. Principal component analysis (PCA) is performed on the SIMS spectra of the 16 polymers, whereby the resulting principal components are able to distinguish phenyl from benzyl groups, mono-functional from multi-functional monomers and acrylates from methacrylates. The principal components are applied to copolymer series to assess the predictive capabilities of the PCA. Beyond being able to predict the copolymer ratio, in some cases, the SIMS analysis is able to provide insight into the molecular sequence of a copolymer. The insight gained in this study will be beneficial for developing structure-function relationships based upon ToF-SIMS data of polymer libraries. © 2016 The Authors Surface and Interface Analysis Published by John Wiley & Sons Ltd.

  13. EFFECT OF CLEARANCE THE BALL BEARINGS ON INCORRECT WORK OF THREE-SUPORT BEARING SHAFT

    Directory of Open Access Journals (Sweden)

    Jarosław KACZOR

    2014-06-01

    Full Text Available Durability deep groove ball bearings depends on factors (called attributes design, technological and operational. Among the design features one of the most important is play in the bearings. Polish Norm shows five groups of looseness in the bearings, in which the play range from 0 to 105 microns. Manufacturers of rolling bearings they only play group, which has a bearing data, without giving the exact value of the slack. Aim of this study is to determine how it affects the play in the bearings to work three-bearing shafts, including elasticity and resilience three-bearing shafts.

  14. Identification of amines in wintertime ambient particulate material using high resolution aerosol mass spectrometry

    Science.gov (United States)

    Bottenus, Courtney L. H.; Massoli, Paola; Sueper, Donna; Canagaratna, Manjula R.; VanderSchelden, Graham; Jobson, B. Thomas; VanReken, Timothy M.

    2018-05-01

    Significant amounts of amines were detected in fine particulate matter (PM) during ambient wintertime conditions in Yakima, WA, using a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Positive matrix factorization (PMF) of the organic aerosol (OA) signal resulted in a six-factor solution that included two previously unreported amine OA factors. The contributions of the amine factors were strongly episodic, but the concentration of the combined amine factors was as high as 10-15 μg m-3 (2-min average) during those episodes. In one occasion, the Amine-II component was 45% of total OA signal. The Amine-I factor was dominated by spectral peaks at m/z 86 (C5H12N+) and m/z 100 (C6H14N+), while the Amine-II factor was dominated by spectral peaks at m/z 58 (C3H8N+ and C2H6N2+) and m/z 72 (C4H10N+ and C3H8N2+). The ions dominating each amine factor showed distinct time traces, suggesting different sources or formation processes. Investigation into the chemistry of the amine factors suggests a correlation with inorganic anions for Amine-I, but no evidence that the Amine-II was being neutralized by the same inorganic ions. We also excluded the presence of organonitrates (ON) in the OA. The presence of C2H4O2+ at m/z 60 (a levoglucosan fragment) in the Amine-I spectrum suggests some influence of biomass burning emissions (more specifically residential wood combustion) in this PMF factor, but wind direction suggested that the most likely sources of these amines were agricultural activities and feedlots to the S-SW of the site.

  15. The mysterious trace amines: protean neuromodulators of synaptic transmission in mammalian brain.

    Science.gov (United States)

    Burchett, Scott A; Hicks, T Philip

    2006-08-01

    The trace amines are a structurally related group of amines and their isomers synthesized in mammalian brain and peripheral nervous tissues. They are closely associated metabolically with the dopamine, noradrenaline and serotonin neurotransmitter systems in mammalian brain. Like dopamine, noradrenaline and serotonin the trace amines have been implicated in a vast array of human disorders of affect and cognition. The trace amines are unique as they are present in trace concentrations, exhibit high rates of metabolism and are distributed heterogeneously in mammalian brain. While some are synthesized in their parent amine neurotransmitter systems, there is also evidence to suggest other trace amines may comprise their own independent neurotransmitter systems. A substantial body of evidence suggests that the trace amines may play very significant roles in the coordination of biogenic amine-based synaptic physiology. At high concentrations, they have well-characterized presynaptic "amphetamine-like" effects on catecholamine and indolamine release, reuptake and biosynthesis; at lower concentrations, they possess postsynaptic modulatory effects that potentiate the activity of other neurotransmitters, particularly dopamine and serotonin. The trace amines also possess electrophysiological effects that are in opposition to these neurotransmitters, indicating to some researchers the existence of receptors specific for the trace amines. While binding sites or receptors for a few of the trace amines have been advanced, the absence of cloned receptor protein has impeded significant development of their detailed mechanistic roles in the coordination of catecholamine and indolamine synaptic physiology. The recent discovery and characterization of a family of mammalian G protein-coupled receptors responsive to trace amines such as beta-phenylethylamine, tyramine, and octopamine, including socially ingested psychotropic drugs such as amphetamine, 3,4-methylenedioxymethamphetamine, N

  16. Methemoglobin Formation and Characterization of Hemoglobin Adducts of Carcinogenic Aromatic Amines and Heterocyclic Aromatic Amines.

    Science.gov (United States)

    Pathak, Khyatiben V; Chiu, Ting-Lan; Amin, Elizabeth Ambrose; Turesky, Robert J

    2016-03-21

    Arylamines (AAs) and heterocyclic aromatic amines (HAAs) are structurally related carcinogens formed during the combustion of tobacco or cooking of meat. They undergo cytochrome P450 mediated N-hydroxylation to form metabolites which bind to DNA and lead to mutations. The N-hydroxylated metabolites of many AAs also can undergo a co-oxidation reaction with oxy-hemolgobin (HbO2) to form methemoglobin (met-Hb) and the arylnitroso intermediates, which react with the β-Cys(93) chain of Hb to form Hb-arylsulfinamide adducts. The biochemistry of arylamine metabolism has been exploited to biomonitor certain AAs through their Hb arylsulfinamide adducts in humans. We examined the reactivity of HbO2 with the N-hydroxylated metabolites of 4-aminobiphenyl (ABP, HONH-ABP), aniline (ANL, HONH-ANL), and the HAAs 2-amino-9H-pyrido[2,3-b]indole (AαC, HONH-AαC), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP, HONH-PhIP), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx, HONH-MeIQx). HONH-ABP, HO-ANL, and HONH-AαC induced methemoglobinemia and formed Hb sulfinamide adducts. However, HONH-MeIQx and HONH-PhIP did not react with the oxy-heme complex, and met-Hb formation and chemical modification of the β-Cys(93) residue were negligible. Molecular modeling studies showed that the distances between the H-ON-AA or H-ON-HAA substrates and the oxy-heme complex of HbO2 were too far away to induce methemoglobinemia. Different conformational changes in flexible helical and loop regions around the heme pocket induced by the H-ON-AA or H-ON-HAAs may explain the different proclivities of these chemicals to induce methemoglobinemia. Hb-Cys(93β) sulfinamide and sulfonamide adducts of ABP, ANL, and AαC were identified, by Orbitrap MS, following the proteolysis of Hb with trypsin, Glu-C, or Lys-C. Hb sulfinamide and sulfonamide adducts of ABP were identified in the blood of mice exposed to ABP, by Orbitrap MS. This is the first report of the identification of intact Hb

  17. Journal and Wave Bearing Impedance Calculation Software

    Science.gov (United States)

    Hanford, Amanda; Campbell, Robert

    2012-01-01

    The wave bearing software suite is a MALTA application that computes bearing properties for user-specified wave bearing conditions, as well as plain journal bearings. Wave bearings are fluid film journal bearings with multi-lobed wave patterns around the circumference of the bearing surface. In this software suite, the dynamic coefficients are outputted in a way for easy implementation in a finite element model used in rotor dynamics analysis. The software has a graphical user interface (GUI) for inputting bearing geometry parameters, and uses MATLAB s structure interface for ease of interpreting data. This innovation was developed to provide the stiffness and damping components of wave bearing impedances. The computational method for computing bearing coefficients was originally designed for plain journal bearings and tilting pad bearings. Modifications to include a wave bearing profile consisted of changing the film thickness profile given by an equation, and writing an algorithm to locate the integration limits for each fluid region. Careful consideration was needed to implement the correct integration limits while computing the dynamic coefficients, depending on the form of the input/output variables specified in the algorithm.

  18. From caffeine to fish waste: amine compounds present in food and drugs and their interactions with primary amine oxidase.

    LENUS (Irish Health Repository)

    Olivieri, Aldo

    2011-07-01

    Tissue bound primary amine oxidase (PrAO) and its circulating plasma-soluble form are involved, through their catalytic activity, in important cellular roles, including the adhesion of lymphocytes to endothelial cells during various inflammatory conditions, the regulation of cell growth and maturation, extracellular matrix deposition and maturation and glucose transport. PrAO catalyses the oxidative deamination of several xenobiotics and has been linked to vascular toxicity, due to the generation of cytotoxic aldehydes. In this study, a series of amines and aldehydes contained in food and drugs were tested via a high-throughput assay as potential substrates or inhibitors of bovine plasma PrAO. Although none of the compounds analyzed were found to be substrates for the enzyme, a series of molecules, including caffeine, the antidiabetics phenformin and tolbutamide and the antimicrobial pentamidine, were identified as PrAO inhibitors. Although the inhibition observed was in the millimolar and micromolar range, these data show that further work will be necessary to elucidate whether the interaction of ingested biogenic or xenobiotic amines with PrAO might adversely affect its biological roles.

  19. Oxidation of aromatic amines and diamines by OH radicals. Formation and ionization constants of amine cation radicals in water

    International Nuclear Information System (INIS)

    Hayon, E.; Rao, P.S.

    1975-01-01

    The one-electron oxidation by hydroxyl radicals of aromatic amines and diamines in water was studied using the fast-reaction technique of pulse radiolysis and kinetic absorption spectrophotometry. The following compounds were examined: N,N,N 1 ,N 1 - tetramethyl-p-phenylenediamine (TMPD), p-phenylenediamine (PD), N,N-dimethyl-p-phenylenediamene (DMPD), N,N,N 1 ,N 1 -tetramethylbenzidine (TMB), and diphenylamine (DPA). The main initial reaction of the OH radicals is suggested to be an addition to these compounds to give absorption spectra which absorb strongly in the visible and uv regions. These OH radical adducts decay by first-order kinetics and have lifetimes of approximately 5-50 μsec, dependent on the pH, buffer concentration, and the nature of the aromatic amines and diamines. They decay to give species with somewhat similar absorption spectra and extinction coefficients, which are very long lived in the absence of oxygen. The latter species are assigned to the cation radicals TMPD. + , PD. + , DMPD. + , TMB. + , and DPA. + . The OH radical adducts and the cation radicals have acid-base properties. The pK/sub a/ values of the cation radicals TMPDH. 2+ , PDH. 2+ , DMPDH. 2+ , TMBH. 2+ , and DPAH. 2+ were found to be 5.3, 5.9, 6.1, 5.1, and 4.2, respectively. The results indicate that these aromatic amines and diamines can be oxidized by free radicals to yield the corresponding cation radicals. (U.S.)

  20. Effect of donor orientation on ultrafast intermolecular electron transfer in coumarin-amine systems

    International Nuclear Information System (INIS)

    Singh, P. K.; Nath, S.; Bhasikuttan, A. C.; Kumbhakar, M.; Mohanty, J.; Sarkar, S. K.; Mukherjee, T.; Pal, H.

    2008-01-01

    Effect of donor amine orientation on nondiffusive ultrafast intermolecular electron transfer (ET) reactions in coumarin-amine systems has been investigated using femtosecond fluorescence upconversion measurements. Intermolecular ET from different aromatic and aliphatic amines used as donor solvents to the excited coumarin-151 (C151) acceptor occurs with ultrafast rates such that the shortest fluorescence lifetime component (τ 1 ) is the measure of the fastest ET rate (τ 1 =τ ET fast =(k ET fast ) -1 ), assigned to the C151-amine contact pairs in which amine donors are properly oriented with respect to C151 to maximize the acceptor-donor electronic coupling (V el ). It is interestingly observed that as the amine solvents are diluted by suitable diluents (either keeping solvent dielectric constant similar or with increasing dielectric constant), the τ 1 remains almost in the similar range as long as the amine dilution does not cross a certain critical limit, which in terms of the amine mole fraction (x A ) is found to be ∼0.4 for aromatic amines and ∼0.8 for aliphatic amines. Beyond these dilutions in the two respective cases of the amine systems, the τ 1 values are seen to increase very sharply. The large difference in the critical x A values involving aromatic and aliphatic amine donors has been rationalized in terms of the largely different orientational restrictions for the ET reactions as imposed by the aliphatic (n-type) and aromatic (π-type) nature of the amine donors [A. K. Satpati et al., J. Mol. Struct. 878, 84 (2008)]. Since the highest occupied molecular orbital (HOMO) of the n-type aliphatic amines is mostly centralized at the amino nitrogen, only some specific orientations of these amines with respect to the close-contact acceptor dye [also of π-character; A. K. Satpati et al., J. Mol. Struct. 878, 84 (2008) and E. W. Castner et al., J. Phys. Chem. A 104, 2869 (2000)] can give suitable V el and thus ultrafast ET reaction. In contrary, the

  1. Stable isotopes to detect food-conditioned bears and to evaluate human-bear management

    Science.gov (United States)

    Hopkins, John B.; Koch, Paul L.; Schwartz, Charles C.; Ferguson, Jake M.; Greenleaf, Schuyler S.; Kalinowski, Steven T.

    2012-01-01

    We used genetic and stable isotope analysis of hair from free-ranging black bears (Ursus americanus) in Yosemite National Park, California, USA to: 1) identify bears that consume human food, 2) estimate the diets of these bears, and 3) evaluate the Yosemite human–bear management program. Specifically, we analyzed the isotopic composition of hair from bears known a priori to be food-conditioned or non-food-conditioned and used these data to predict whether bears with an unknown management status were food-conditioned (FC) or non-food-conditioned (NFC). We used a stable isotope mixing model to estimate the proportional contribution of natural foods (plants and animals) versus human food in the diets of FC bears. We then used results from both analyses to evaluate proactive (population-level) and reactive (individual-level) human–bear management, and discussed new metrics to evaluate the overall human–bear management program in Yosemite. Our results indicated that 19 out of 145 (13%) unknown bears sampled from 2005 to 2007 were food-conditioned. The proportion of human food in the diets of known FC bears likely declined from 2001–2003 to 2005–2007, suggesting proactive management was successful in reducing the amount of human food available to bears. In contrast, reactive management was not successful in changing the management status of known FC bears to NFC bears, or in reducing the contribution of human food to the diets of FC bears. Nine known FC bears were recaptured on 14 occasions from 2001 to 2007; all bears were classified as FC during subsequent recaptures, and human–bear management did not reduce the amount of human food in the diets of FC bears. Based on our results, we suggest Yosemite continue implementing proactive human–bear management, reevaluate reactive management, and consider removing problem bears (those involved in repeated bear incidents) from the population.

  2. A one-pot chemoselective synthesis of secondary amines by using a biomimetic electrocatalytic system

    International Nuclear Information System (INIS)

    Largeron, Martine

    2009-01-01

    A one-pot electrochemically induced oxidation-imine formation-reduction route to secondary amines is described in detail. The key step of the process consists of the o-iminoquinone-mediated chemoselective catalytic oxidation of a primary aliphatic amine substrate, in the presence of a second amine used as the alkylating agent. Through the examination of the scope of the reaction by systematically varying both amine substrate and amine alkylating agent, it can be shown that this reaction sequence, leaving ammonia as the sole by-product, allows the rapid synthesis of various secondary amines in moderate to good yields. This process, that highlights the pre-eminent green advantages of electrochemical synthesis, especially the utilization of electricity as energy instead of chemical reagents, high atom economy as well as ambient temperature and pressure, could be a mild alternative to already reported synthetic methods.

  3. A one-pot chemoselective synthesis of secondary amines by using a biomimetic electrocatalytic system

    Energy Technology Data Exchange (ETDEWEB)

    Largeron, Martine [UMR CNRS 8638, Synthese et Structure de Molecules d' nteret Pharmacologique, Universite Paris Descartes, Faculte des Sciences Pharmaceutiques et Biologiques, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France)], E-mail: martine.largeron@parisdescartes.fr

    2009-09-01

    A one-pot electrochemically induced oxidation-imine formation-reduction route to secondary amines is described in detail. The key step of the process consists of the o-iminoquinone-mediated chemoselective catalytic oxidation of a primary aliphatic amine substrate, in the presence of a second amine used as the alkylating agent. Through the examination of the scope of the reaction by systematically varying both amine substrate and amine alkylating agent, it can be shown that this reaction sequence, leaving ammonia as the sole by-product, allows the rapid synthesis of various secondary amines in moderate to good yields. This process, that highlights the pre-eminent green advantages of electrochemical synthesis, especially the utilization of electricity as energy instead of chemical reagents, high atom economy as well as ambient temperature and pressure, could be a mild alternative to already reported synthetic methods.

  4. Sponges with covalently tethered amines for high-efficiency carbon capture

    KAUST Repository

    Qi, Genggeng

    2014-12-12

    © 2014 Macmillan Publishers Limited. All rights reserved. Adsorption using solid amine sorbents is an attractive emerging technology for energy-efficient carbon capture. Current syntheses for solid amine sorbents mainly based on physical impregnation or grafting-to methods (for example, aminosilane-grafting) lead to limited sorbent performance in terms of stability and working capacity, respectively. Here we report a family of solid amine sorbents using a grafting-from synthesis approach and synthesized by cationic polymerization of oxazolines on mesoporous silica. The sorbent with high amount of covalently tethered amines shows fast adsorption rate, high amine efficiency and sorbent capacity well exceeding the highest value reported to date for lowerature carbon dioxide sorbents under simulated flue gas conditions. The demonstrated efficiency of the new amine-immobilization chemistry may open up new avenues in the development of advanced carbon dioxide sorbents, as well as other nitrogen-functionalized systems.

  5. Carbon Dioxide-Mediated C(sp3)-H Arylation of Amine Substrates.

    Science.gov (United States)

    Kapoor, Mohit; Liu, Daniel; Young, Michael C

    2018-05-25

    Elaborating amines via C-H functionalization has been an important area of research over the past decade but has generally relied on an added directing group or sterically hindered amine approach. Since free-amine-directed C(sp 3 )-H activation is still primarily limited to cyclization reactions and to improve the sustainability and reaction scope of amine-based C-H activation, we present a strategy using CO 2 in the form of dry ice that facilitates intermolecular C-H arylation. This methodology has been used to enable an operationally simple procedure whereby 1° and 2° aliphatic amines can be arylated selectively at their γ-C-H positions. In addition to potentially serving as a directing group, CO 2 has also been demonstrated to curtail the oxidation of sensitive amine substrates.

  6. Direct α-C-H bond functionalization of unprotected cyclic amines

    Science.gov (United States)

    Chen, Weijie; Ma, Longle; Paul, Anirudra; Seidel, Daniel

    2018-02-01

    Cyclic amines are ubiquitous core structures of bioactive natural products and pharmaceutical drugs. Although the site-selective abstraction of C-H bonds is an attractive strategy for preparing valuable functionalized amines from their readily available parent heterocycles, this approach has largely been limited to substrates that require protection of the amine nitrogen atom. In addition, most methods rely on transition metals and are incompatible with the presence of amine N-H bonds. Here we introduce a protecting-group-free approach for the α-functionalization of cyclic secondary amines. An operationally simple one-pot procedure generates products via a process that involves intermolecular hydride transfer to generate an imine intermediate that is subsequently captured by a nucleophile, such as an alkyl or aryl lithium compound. Reactions are regioselective and stereospecific and enable the rapid preparation of bioactive amines, as exemplified by the facile synthesis of anabasine and (-)-solenopsin A.

  7. Conversion of alcohols to enantiopure amines through dual-enzyme hydrogen-borrowing cascades.

    Science.gov (United States)

    Mutti, Francesco G; Knaus, Tanja; Scrutton, Nigel S; Breuer, Michael; Turner, Nicholas J

    2015-09-25

    α-Chiral amines are key intermediates for the synthesis of a plethora of chemical compounds at industrial scale. We present a biocatalytic hydrogen-borrowing amination of primary and secondary alcohols that allows for the efficient and environmentally benign production of enantiopure amines. The method relies on a combination of two enzymes: an alcohol dehydrogenase (from Aromatoleum sp., Lactobacillus sp., or Bacillus sp.) operating in tandem with an amine dehydrogenase (engineered from Bacillus sp.) to aminate a structurally diverse range of aromatic and aliphatic alcohols, yielding up to 96% conversion and 99% enantiomeric excess. Primary alcohols were aminated with high conversion (up to 99%). This redox self-sufficient cascade possesses high atom efficiency, sourcing nitrogen from ammonium and generating water as the sole by-product. Copyright © 2015, American Association for the Advancement of Science.

  8. Decomposition of some amines and amino acids in steam generator environments

    International Nuclear Information System (INIS)

    Jayaweera, P.; Hettiarachchi, S.; Millett, P.J.

    1994-01-01

    Hydrothermal decomposition rate constants and high temperature pH values of some selected high-molecular weight amines and amino acids were measured under simulated steam generator conditions. These amines and amino acids were evaluated as potential crevice buffering agents for steam generator applications in pressurized water reactors. The study showed that, although the high molecular weight amines undergo hydrothermal decomposition, they have a better buffer capacity than their low molecular weight counterparts at 290 C. The amines provide effective crevice buffering by increasing the pH of the simulated crevice solution by as much as 2.84 to 4.24 units. However, volatility data for the amines and amino acids are needed before in-plant testing to ensure that amines can concentrate sufficiently in steam generator crevices to provide effective buffering

  9. Technology development for indigenous water lubricated bearings

    International Nuclear Information System (INIS)

    Limaye, P.K.; Soni, N.L.; Agrawal, R.G.

    2010-01-01

    Water Lubricated Bearings (WLB) are used in various mechanisms of fuel handling systems of PHWRs and AHWR. Availability and random failures of these bearings was a major factor in refuelling operations. Indigenous development of these bearings was taken up and 7 types of antifriction bearings in various sizes (totaling 37 variants) for PHWR, AHWR and Dhruva applications were successfully developed. This paper deals with various aspects of WLB development. (author)

  10. Research In Diagnosing Bearing Defects From Vibrations

    Science.gov (United States)

    Zoladz, T.; Earhart, E.; Fiorucci, T.

    1995-01-01

    Report describes research in bearing-defect signature analysis - use of vibration-signal analysis to diagnose defects in roller and ball bearings. Experiments performed on bearings in good condition and other bearings in which various parts scratched to provide known defects correlated with vibration signals. Experiments performed on highly instrumented motor-driven rotor assembly at speeds up to 10,050 r/min, using accelerometers, velocity probes, and proximity sensors mounted at various locations on assembly to measure vibrations.

  11. Cool Polar Bears: Dabbing on the Texture

    Science.gov (United States)

    O'Connell, Jean

    2011-01-01

    In this article, the author describes how her second-graders created their cool polar bears. The students used the elements of shape and texture to create the bears. They used Monet's technique of dabbing paint so as to give the bear some texture on his fur.

  12. 49 CFR 229.64 - Plain bearings.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to the...

  13. Bearing-Mounting Concept Accommodates Thermal Expansion

    Science.gov (United States)

    Nespodzany, Robert; Davis, Toren S.

    1995-01-01

    Pins or splines allow radial expansion without slippage. Design concept for mounting rotary bearing accommodates differential thermal expansion between bearing and any structure(s) to which bearing connected. Prevents buildup of thermal stresses by allowing thermal expansion to occur freely but accommodating expansion in such way not to introduce looseness. Pin-in-slot configuration also maintains concentricity.

  14. Bears and pipeline construction in Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Follmann, E.H.; Hechtel, J.L. (Univ. of Alaska Fairbanks, AK (USA))

    1990-06-01

    Serious problems were encountered with bears during construction of the 1274-km trans-Alaska oil pipeline between Prudhoe Bay and Valdez. This multi-billion-dollar project traversed both black bear (Ursus americanus Pallas) and grizzly bear (U. arctos L.) habitat throughtout its entire length. Plans for dealing with anticipated problems with bears were often inadequate. Most (71%) problems occurred north of the Yukon River in a previously roadless wilderness where inadequate refuse disposal and widespread animal feeding created dangerous situations. Of the 192 officially reported bear problems associated with the Trans-Alaska Pipeline System (TAPS) (1971-1979), about 65% involved the presence of bears in camps or dumps, 13% the feeding of bears on garbage or handouts, 10% property damage or economic loss, 7% bears under and in buildings, and only 5% charges by bears. Remarkably, no bear-related injuries were reported, suggesting that bears became accustomed to people and did not regard them as a threat. Following construction of the TAPS there have been proposals for pipelines to transport natural gas from Prudhoe Bay to southern and Pacific-rim markets. Based on past experience, some animal control measures were developed during the planning phase for the authorized gas pipeline route in Alaska. Fences installed around 100-person survey camps were found to be effective in deterring bears in two traditionally troublesome areas. 16 refs., 7 figs., 1 tab.

  15. Fractal analysis of polar bear hairs

    Directory of Open Access Journals (Sweden)

    Wang Qing-Li

    2015-01-01

    Full Text Available Hairs of a polar bear (Ursus maritimus are of superior properties such as the excellent thermal protection. Why do polar bears can resist such cold environment? The paper concludes that its fractal porosity plays an important role, and its fractal dimensions are very close to the golden mean, 1.618, revealing the possible optimal structure of polar bear hair.

  16. 36 CFR 13.1236 - Bear orientation.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Bear orientation. 13.1236 Section 13.1236 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR... Developed Area § 13.1236 Bear orientation. All persons visiting the BCDA must receive an NPS-approved Bear...

  17. 14 CFR 29.623 - Bearing factors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 29.623 Section 29.623... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.623 Bearing factors. (a... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

  18. 14 CFR 27.623 - Bearing factors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 27.623 Section 27.623... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction General § 27.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

  19. 14 CFR 25.623 - Bearing factors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 25.623 Section 25.623... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

  20. 14 CFR 23.623 - Bearing factors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 23.623 Section 23.623... Bearing factors. (a) Each part that has clearance (free fit), and that is subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of normal relative motion. (b) For...

  1. Study on synthesis, application and mechanism of benzophenone/amine initiator

    International Nuclear Information System (INIS)

    Xiong Wei; Liu Jinshui; Wen Yinjun; Wan Qizhong; Zhou Xianyan; Xiao Hanling; Yang Jianwen

    1999-01-01

    Through Michael addition reaction of trimethylolpropane triacrylate (TMPTA) with diethylamine (DEA), a new kind of tertiary amine derivative was synthesized and its structure was identified by 'H-NMR. When used in combination with benzophenone, this amine presented excellent curing speed and could be a substitute for initiator Darocur R 1173, which is effective but expensive. If so, the cost of UV-curable coatings can descend apparently. The functioning mechanism of benzophenone/amine bimolecular initiator was studied

  2. Synthesis of propargylic and allenic carbamates via the C-H amination of alkynes.

    Science.gov (United States)

    Grigg, R David; Rigoli, Jared W; Pearce, Simon D; Schomaker, Jennifer M

    2012-01-06

    Propargylic amines are important intermediates for the synthesis of nitrogen-containing heterocycles. The insertion of a nitrene into a propargylic C-H bond has not been explored, despite the attention directed toward the Rh-catalyzed amination of other types of C-H bonds. In this communication, the conversion of a series of homopropargylic carbamates to propargylic carbamates and aminated allenes is described. © 2011 American Chemical Society

  3. Analysis of Biogenic Amines by GC/FID and GC/MS

    OpenAIRE

    Nakovich, Laura

    2003-01-01

    Low levels of biogenic amines occur naturally, but high levels (FDA sets 50 ppm of histamine in fish as the maximum allowable level) can lead to scombroid poisoning. Amines in general are difficult to analyze by Gas Chromatography (GC) due to their lack of volatility and their interaction with the GC column, often leading to significant tailing and poor reproducibility. Biogenic amines need to be derivatized before both GC and HPLC analyses. The objective of this research was to devel...

  4. The BEAR Beamline at Elettra

    International Nuclear Information System (INIS)

    Nannarone, S.; Pasquali, L.; Selvaggi, G.; Borgatti, F.; DeLuisa, A.; Doyle, B.P.; Gazzadi, G.C.; Giglia, A.; Finetti, P.; Pedio, M.; Mahne, N.; Naletto, G.; Pelizzo, M.G.; Tondello, G.

    2004-01-01

    The BEAR (Bending Magnet for Emission Absorption and Reflectivity) beamline is installed at the right exit of the 8.1 bending magnet at ELETTRA. The beamline - in operation since January 2003 - delivers linear and circularly polarized radiation in the 5 - 1600 eV energy range. The experimental station is composed of a UHV chamber for reflectivity, absorption, fluorescence and angle resolved photoemission measurements and a UHV chamber for in-situ sample preparation

  5. BEAR

    DEFF Research Database (Denmark)

    Houmøller, Sabina Storbjerg; Wolff, Anne; Hougaard, Dan Dupont

    2017-01-01

    profiling and fitting strategies. Data from 2000 patients are collected from the departments of Audiology in Odense and Aalborg University Hospital. Some of the registered variables include gender, age, and health related questions, noise exposure and whether they are suffering from tinnitus. The database...... subgroups of HA users, including experienced versus new HA users will be made. Previous noise exposure and the relation to the occurrence of tinnitus will be investigated as well....

  6. Control of Biogenic Amines in Fermented Sausages: Role of Starter Cultures

    Science.gov (United States)

    Latorre-Moratalla, M.L.; Bover-Cid, Sara; Veciana-Nogués, M.T.; Vidal-Carou, M.C.

    2012-01-01

    Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed. PMID:22586423

  7. Control of biogenic amines in fermented sausages: role of starter cultures

    Directory of Open Access Journals (Sweden)

    Mariluz eLatorre-Moratalla

    2012-05-01

    Full Text Available Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed.

  8. Catalyst- and Reagent-free Electrochemical Azole C-H Amination.

    Science.gov (United States)

    Qiu, Youai; Struwe, Julia; Meyer, Tjark H; Oliveira, Joao Carlos Agostinho Carlos Agostinho; Ackermann, Lutz

    2018-06-14

    Catalyst-, and chemical oxidant-free electrochemical azole C-H aminations were accomplished via cross-dehydrogenative C-H/N-H functionalization. The catalyst-free electrochemical C-H amination proved feasible on azoles with high levels of efficacy and selectivity, avoiding the use of stoichiometric oxidants under ambient conditions. Likewise, the C(sp3)-H nitrogenation proved viable under otherwise identical conditions. The dehydrogenative C-H amination featured ample scope, including cyclic and acyclic aliphatic amines as well as anilines, and employed sustainable electricity as the sole oxidant. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Mechanism of the N-Hydroxylation of Primary and Secondary Amines by Cytochrome P450

    DEFF Research Database (Denmark)

    Seger, Signe T.; Rydberg, Patrik; Olsen, Lars

    2015-01-01

    Cytochrome P450 enzymes (CYPs) metabolize alkyl- and arylamines, generating several different products. For the primary and secondary amines, some of these reactions result in hydroxylated amines, which may be toxic. Thus, when designing new drugs containing amine groups, it is important to be able...... to predict if a given compound will be a substrate for CYPs, in order to avoid toxic metabolites, and hence to understand the mechanism that is utilized by CYPs. Two possible mechanisms, for the N-hydroxylation of primary and secondary amines mediated by CYPs, are studied by density functional theory (DFT...

  10. Chemical and Molecular Descriptors for the Reactivity of Amines with CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Anita S.; Kitchin, John R.

    2012-10-24

    Amine-based solvents are likely to play an important role in CO{sub 2} capture applications in the future, and the identification of amines with superior performance will facilitate their use in CO{sub 2} capture. While some improvements in performance will be achieved through process modifications, modifying the CO{sub 2} capture performance of an amine also implies in part an ability to modify the reactions between the amine and CO{sub 2} through development of new functionalized amines. We present a computational study of trends in the reactions between CO{sub 2} and functionalized amines with a focus on identifying molecular descriptors that determine trends in reactivity. We examine the formation of bicarbonate and carbamate species on three classes of functionalized amines: alkylamines, alkanolamines, and fluorinated alkylamines including primary, secondary and tertiary amines in each class. These functional groups span electron-withdrawing to donating behavior, hydrogen-bonding, extent of functionalization, and proximity effects of the functional groups. Electron withdrawing groups tend to destabilize CO{sub 2} reaction products, whereas electron-donating groups tend to stabilize CO{sub 2} reaction products. Hydrogen bonding stabilizes CO{sub 2} reaction products. Electronic structure descriptors based on electronegativity were found to describe trends in the bicarbonate formation energy. A chemical correlation was observed between the carbamate formation energy and the carbamic acid formation energy. The local softness on the reacting N in the amine was found to partially explain trends carbamic acid formation energy.

  11. Mechanistic insights into the oxidative dehydrogenation of amines to nitriles in continuous flow

    DEFF Research Database (Denmark)

    Corker, Emily C.; Ruiz-Martínez, Javier; Riisager, Anders

    2015-01-01

    The oxidative dehydrogenation of various aliphatic amines to their corresponding nitrile compounds using RuO2/Al2O3 catalysts in air was successfully applied to a continuous flow reaction. Conversions of amines (up to >99%) and yields of nitriles (up to 77%) varied depending on reaction conditions...... and the amine utilised. The presence of water was found to be important for the activity and stability of the RuO2/Al2O3 catalyst. The Hammett relationship and in situ infrared spectroscopy were applied to divulge details about the catalytic mechanism of the oxidative dehydrogenation of amines over RuO2/Al2O3...

  12. Impact of thiol and amine functionalization on photoluminescence properties of ZnO films

    International Nuclear Information System (INIS)

    Jayalakshmi, G.; Saravanan, K.; Balasubramanian, T.

    2013-01-01

    In the present study, we have investigated surface functionalization of ZnO films with dodecanethiol (Thiol) and trioctylamine (amine) by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), contact angle (CA) and photoluminescence (PL) measurements. The chemical bondings of thiol and amine with ZnO have been confirmed via the formation of Zn–S and Zn–N bonds by XPS measurements. AFM measurements on ZnO films before and after surface functionalization with thiol and amine provide evidence for the successful functionalization of thiol and amine on ZnO surfaces without any island formation. The CA measurements on ZnO films before and after surface functionalization with thiol and amine show the hydrophobic nature. PL measurements of thiol and amine functionalized ZnO show enhancements of UV emission and quenching of visible emission. The enhanced UV emissions in thiol and amine functionalized ZnO films suggest that the surface defects such as oxygen vacancies are passivated by thiol and amine functionalization. -- Highlights: ► Surface functionalization is a new approach to reduce surface dependent non-radiative process. ► Oxygen vacancies are passivated on surface functionalization. ► Thiol and amine functionalized ZnO show enhancements of UV emission

  13. Ligand-Enabled γ-C(sp(3))-H Olefination of Amines: En Route to Pyrrolidines.

    Science.gov (United States)

    Jiang, Heng; He, Jian; Liu, Tao; Yu, Jin-Quan

    2016-02-17

    Pd(II)-catalyzed olefination of γ-C(sp(3))-H bonds of triflyl (Tf) and 4-nitrobenzenesulfonyl (Ns) protected amines is achieved. Subsequent aza-Wacker oxidative cyclization or conjugate addition of the olefinated intermediates provides a variety of C-2 alkylated pyrrolidines. Three pyridine- and quinoline-based ligands are developed to match different classes of amine substrates, demonstrating a rare example of ligand-enabled C(sp(3))-H olefination reactions. The use of Ns protecting group to direct C(sp(3))-H activation of alkyl amines is also a significant step toward practical C-H functionalizations of alkyl amines.

  14. Amines as extracting agents for the quantitative determinations of actinides in biological samples

    International Nuclear Information System (INIS)

    Singh, N.P.

    1987-01-01

    The use of amines (primary, secondary and tertiary chains and quaternary ammonium salts) as extracting agents for the quantitative determination of actinides in biological samples is reviewed. Among the primary amines, only Primene JM-T is used to determine Pu in urine and bone. No one has investigated the possibility of using secondary amines to quantitatively extract actinides from biological samples. Among the tertiary amines, tri-n-octylamine, tri-iso-octylamine, tyricaprylamine (Alamine) and trilaurylamine (tridodecylamine) are used extensively to extract and separate the actinides from biological samples. Only one quaternary ammonium salt, methyltricapryl ammonium chloride (Aliquat-336), is used to extract Pu from biological samples. (author) 28 refs

  15. Scaling laws for radial foil bearings

    Science.gov (United States)

    Honavara Prasad, Srikanth

    The effects of fluid pressurization, structural deformation of the compliant members and heat generation in foil bearings make the design and analysis of foil bearings very complicated. The complex fluid-structural-thermal interactions in foil bearings also make modeling efforts challenging because these phenomena are governed by highly non-linear partial differential equations. Consequently, comparison of various bearing designs require detailed calculation of the flow fields (velocities, pressures), bump deflections (structural compliance) and heat transfer phenomena (viscous dissipation in the fluid, frictional heating, temperature profile etc.,) resulting in extensive computational effort (time/hardware). To obviate rigorous computations and aid in feasibility assessments of foil bearings of various sizes, NASA developed the "rule of thumb" design guidelines for estimation of journal bearing load capacity. The guidelines are based on extensive experimental data. The goal of the current work is the development of scaling laws for radial foil bearings to establish an analytical "rule of thumb" for bearing clearance and bump stiffness. The use of scale invariant Reynolds equation and experimentally observed NASA "rule of thumb" yield scale factors which can be deduced from first principles. Power-law relationships between: a. Bearing clearance and bearing radius, and b. bump stiffness and bearing radius, are obtained. The clearance and bump stiffness values obtained from scaling laws are used as inputs for Orbit simulation to study various cases. As the clearance of the bearing reaches the dimensions of the material surface roughness, asperity contact breaks the fluid film which results in wear. Similarly, as the rotor diameter increases (requiring larger bearing diameters), the load capacity of the fluid film should increase to prevent dry rubbing. This imposes limits on the size of the rotor diameter and consequently bearing diameter. Therefore, this thesis aims

  16. Improvement of journal bearing operation at heavy misalignment using bearing flexibility and compliant liners

    DEFF Research Database (Denmark)

    Thomsen, Kim; Klit, Peder

    2012-01-01

    A flexure journal bearing design is proposed that will improve operational behaviour of a journal bearing at pronounced misalignment. Using a thermoelastohydrodynamic model, it is shown that the proposed flexure journal bearing has vastly increased the hydrodynamic performance compared to the stiff...... bearing when misaligned. The hydrodynamic performance is evaluated on lubricant film thickness, pressure and temperature. Furthermore, the influence of a compliant bearing liner is investigated and it is found that it increases the hydrodynamic performance when applied to a stiff bearing, whereas...... the liner has practically no influence on the flexure journal bearing's performance....

  17. A motor with superconducting magnetic bearings

    International Nuclear Information System (INIS)

    Gladun, A.; Stoye, P.; Verges, P.; Gawalek, W.; Habisreuther, T.; Goernert, P.

    1993-01-01

    Superconducting bearings may be one of the most promising near term applications of HTSC. For use at liquid nitrogen temperature and below, they offer the advantage of lower energy consumption and higher reliability. Different bearing configurations have been proposed. But in order to substitute for conventional bearings a further increase in the critical current density of the superconductor and improved bearing concepts are necessary. For this it is necessary to take into account the peculiarities of the interaction between permanent magnets and bulk superconductors. As a contribution to this programme we present the model of a motor with superconducting magnetic bearings. (orig.)

  18. [Advances in studies on bear bile powder].

    Science.gov (United States)

    Zhou, Chao-fan; Gao, Guo-jian; Liu, Ying

    2015-04-01

    In this paper, a detailed analysis was made on relevant literatures about bear bile powder in terms of chemical component, pharmacological effect and clinical efficacy, indicating bear bile powder's significant pharmacological effects and clinical application in treating various diseases. Due to the complex composition, bear bile powder is relatively toxic. Therefore, efforts shall be made to study bear bile powder's pharmacological effects, clinical application, chemical composition and toxic side-effects, with the aim to provide a scientific basis for widespread reasonable clinical application of bear bile powder.

  19. Valve assembly having remotely replaceable bearings

    International Nuclear Information System (INIS)

    Johnson, E.R.; Tanner, D.E.

    1980-01-01

    A valve assembly having remotely replaceable bearings is disclosed wherein a valve disc is supported within a flow duct for rotation about a pair of axially aligned bearings, one of which is carried by a spindle received within a diametral bore in the valve disc, and the other of which is carried by a bearing support block releasably mounted on the duct circumferentially of an annular collar on the valve disc coaxial with its diametrical bore. The spindle and bearing support block are adapted for remote removal to facilitate servicing or replacement of the valve disc support bearings

  20. Ball Bearing Analysis with the ORBIS Tool

    Science.gov (United States)

    Halpin, Jacob D.

    2016-01-01

    Ball bearing design is critical to the success of aerospace mechanisms. Key bearing performance parameters, such as load capability, stiffness, torque, and life all depend on accurate determination of the internal load distribution. Hence, a good analytical bearing tool that provides both comprehensive capabilities and reliable results becomes a significant asset to the engineer. This paper introduces the ORBIS bearing tool. A discussion of key modeling assumptions and a technical overview is provided. Numerous validation studies and case studies using the ORBIS tool are presented. All results suggest the ORBIS code closely correlates to predictions on bearing internal load distributions, stiffness, deflection and stresses.

  1. Servo Reduces Friction In Flexure Bearing

    Science.gov (United States)

    Clingman, W. Dean

    1991-01-01

    Proposed servocontrol device reduces such resistive torques as stiction, friction, ripple, and cogging in flexure bearing described in LAR-14348, "Flexure Bearing Reduces Startup Friction". Reduces frictional "bump" torque encountered when bearing ball runs into buildup of grease on bearing race. Also used as cable follower to reduce torque caused by cable and hoses when they bend because of motion of bearing. New device includes torquer across ball race. Torquer controlled by servo striving to keep flexure at null, removing torque to outer ring. In effect, device is inner control loop reducing friction, but does not control platforms or any outer-control-loop functions.

  2. Synthesis, Structure Optimization and Antifungal Screening of Novel Tetrazole Ring Bearing Acyl-Hydrazones

    Directory of Open Access Journals (Sweden)

    Manzoor A. Malik

    2012-08-01

    Full Text Available Azoles are generally fungistatic, and resistance to fluconazole is emerging in several fungal pathogens. In an attempt to find novel azole antifungal agents with improved activity, a series of tetrazole ring bearing acylhydrazone derivatives were synthesized and screened for their in vitro antifungal activity. The mechanism of their antifungal activity was assessed by studying their effect on the plasma membrane using flow cytometry and determination of the levels of ergosterol, a fungal-specific sterol. Propidium iodide rapidly penetrated a majority of yeast cells when they were treated with the synthesized compounds at concentrations just above MIC, implying that fungicidal activity resulted from extensive lesions of the plasma membrane. Target compounds also caused a considerable reduction in the amount of ergosterol. The results also showed that the presence and position of different substituents on the phenyl ring of the acylhydrazone pendant seem to play a role on the antifungal activity as well as in deciding the fungistatic and fungicidal nature of the compounds.

  3. Supported polytertiary amines: highly efficient and selective SO2 adsorbents.

    Science.gov (United States)

    Tailor, Ritesh; Abboud, Mohamed; Sayari, Abdelhamid

    2014-01-01

    Tertiary amine containing poly(propyleneimine) second (G2) and third (G3) generation dendrimers as well as polyethyleneimine (PEI) were developed for the selective removal of SO2. N-Alkylation of primary and secondary amines into tertiary amines was confirmed by FTIR and NMR analysis. Such modified polyamines were impregnated on two nanoporous supports, namely, SBA-15PL silica with platelet morphology and ethanol-extracted pore-expanded MCM-41 (PME) composite. In the presence of 0.1% SO2/N2 at 23 °C, the uptake of modified PEI, G2, and G3 supported on SBA-15PL was 2.07, 2.35, and 1.71 mmol/g, respectively; corresponding to SO2/N ratios of 0.22, 0.4, and 0.3. Under the same conditions, the SO2 adsorption capacity of PME-supported modified PEI and G3 was significantly higher, reaching 4.68 and 4.34 mmol/g, corresponding to SO2/N ratios of 0.41 and 0.82, respectively. The working SO2 adsorption capacity decreased with increasing temperature, reflecting the exothermic nature of the process. The adsorption capacity of these materials was enhanced dramatically in the presence of humidity in the gas mixture. FTIR data before SO2 adsorption and after adsorption and regeneration did not indicate any change in the materials. Nonetheless, the SO2 working capacity decreased in consecutive adsorption/regeneration cycles due to evaporation of impregnated polyamines, rather than actual deactivation. FTIR and (13)C and (15)N CP-MAS NMR of fresh and SO2 adsorbed modified G3 on PME confirmed the formation of a complexation adduct.

  4. Solid-phase reductive amination for glycomic analysis.

    Science.gov (United States)

    Jiang, Kuan; Zhu, He; Xiao, Cong; Liu, Ding; Edmunds, Garrett; Wen, Liuqing; Ma, Cheng; Li, Jing; Wang, Peng George

    2017-04-15

    Reductive amination is an indispensable method for glycomic analysis, as it tremendously facilitates glycan characterization and quantification by coupling functional tags at the reducing ends of glycans. However, traditional in-solution derivatization based approach for the preparation of reductively aminated glycans is quite tedious and time-consuming. Here, a simpler and more efficient strategy termed solid-phase reductive amination was investigated. The general concept underlying this new approach is to streamline glycan extraction, derivatization, and purification on non-porous graphitized carbon sorbents. Neutral and sialylated standard glycans were utilized to test the feasibility of the solid-phase method. As results, almost complete labeling of those glycans with four common labels of aniline, 2-aminobenzamide (2-AB), 2-aminobenzoic acid (2-AA) and 2-amino-N-(2-aminoethyl)-benzamide (AEAB) was obtained, and negligible desialylation occurred during sample preparation. The labeled glycans derived from glycoproteins showed excellent reproducibility in high performance liquid chromatography (HPLC) and matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Direct comparisons based on fluorescent absorbance and relative quantification using isotopic labeling demonstrated that the solid-phase strategy enabled 20-30% increase in sample recovery. In short, the solid-phase strategy is simple, reproducible, efficient, and sensitive for glycan analysis. This method was also successfully applied for N-glycan profiling of HEK 293 cells with MALDI-TOF MS, showing its attractive application in the high-throughput analysis of mammalian glycome. Published by Elsevier B.V.

  5. Processing method for drained water containing ethanol amine

    International Nuclear Information System (INIS)

    Wakuta, Kuniharu; Ogawa, Naoki; Sagawa, Hiroshi; Kamiyoshi, Hideki; Fukunaga, Kazuo; Iwamoto, Ken; Miki, Tsuyoshi; Hirata, Toshio

    1998-01-01

    Drained water containing ethanol amine is processed with microorganisms such as hydrazine resistant denitrification bacteria in a biodegrading vessel (A) in the coexistence of nitrous ions and/or nitric ions under an anaerobic condition, and then it is processed with microorganisms such as nitrification bacteria in another biotic oxidation vessel (B) under an aerobic condition to generate the coexistent nitrate ion and/or nitric ion, and returned to the biodegrading vessel (A). Further, they are exposed to air or incorporated with an oxidant and optionally a copper compound such as copper sulfate as a catalyst is added in a step of removing hydrazine. (T.M.)

  6. Economic Considerations for Selecting an Amine Donor in Biocatalytic Transamination

    DEFF Research Database (Denmark)

    Tufvesson, Pär; Nordblad, Mathias; Krühne, Ulrich

    2015-01-01

    the process, in particular the choice of amine donor. This paper discusses these constraints and demonstrates, through simple thermodynamic and economic models, the process targets that need to be set and achieved for a process dependent on allowed process costs and quality targets....... in industry. The technology has been demonstrated in a few selected cases, but widespread implementation and for a broader range of target molecules requires a deeper understanding of the underlying thermodynamic as well as economic constraints for the different choices that can be made in designing...

  7. Phenols and aromatic amines as thermal stabilizers in polyolefin processing

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Jan; Habicher, W. D.; Al-Malaika, S.; Zweifel, H.; Nešpůrek, Stanislav

    2001-01-01

    Roč. 176, - (2001), s. 55-63 ISSN 1022-1360. [International Conference on Polymer Modification, Degradation and Stabilization /1./. Palermo , 03.09.2000-07.09.2000] R&D Projects: GA AV ČR IAA1050901; GA MŠk ME 184; GA MŠk ME 372; GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : thermal stabilizers * phenols * aromatic amines Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.634, year: 2001

  8. Reaction of nitriles intercalation in tantalum pentachloride complexes with amines

    International Nuclear Information System (INIS)

    Glushkova, M.A.; Chumaevskij, N.A.; Khmelevskaya, L.V.; Ershova, M.M.; Buslaev, Yu.A.

    1987-01-01

    Data on the study of aceto-, propio- and benzonitrile intercalation in TaCl 5 complexes with diethyl- and triethylamines in CCl 4 solution are discussed. Using the methods of IR and Raman spectroscopy it has been established that it is the nature of ligand, and not nitrile intercalated in the complex, that affects greatly the composition of final products. In contrast to acetonitrile, intercalation in the complex of propio- and benzonitriles is observed already at room temperature. On the basis of spectral data a supposition is made that carbon tetrachloride used as a solvent accelerates the reaction of nitrile intercalation and promotes their deprotonation in the presence of aprotonic amine

  9. The repertoire of trace amine G-protein-coupled receptors

    DEFF Research Database (Denmark)

    Gloriam, David E.; Bjarnadóttir, Thóra K; Yan, Yi-Lin

    2005-01-01

    eukaryotic species for receptors similar to the mammalian trace amine (TA) receptor subfamily. We identified 18 new receptors in rodents that are orthologous to the previously known TA-receptors. Remarkably, we found 57 receptors (and 40 pseudogenes) of this type in the zebrafish (Danio rerio), while fugu...... (Takifugu rubripes) had only eight receptors (and seven pseudogenes). We mapped 47 of the zebrafish TA-receptors on chromosomes using radiation hybrid panels and meiotic mapping. The results, together with the degree of conservation and phylogenetic relationships displayed among the zebrafish receptors...

  10. Theoretical study on perylene derivatives as fluorescent sensors for amines

    Science.gov (United States)

    Lathiotakis, Nektarios N.; Kerkines, Ioannis S. K.; Theodorakopoulos, Giannoula; Petsalakis, Ioannis D.

    2018-01-01

    A theoretical study is presented on perylene diimide (PDI) and perylene monoimide (PMI) and their action as sensors of amines in solution. Density functional theory (DFT) and Time dependent DFT (TDDFT) calculations are carried out on complexes of PDI and PMI with aniline in THF solution. The optimized geometries for the complexes have aniline lying parallel above the perylene at 3.15 Å and with binding energy of 0.53 eV in the ground state. The results on the excited states are consistent with a photoinduced electron transfer (PET) mechanism. The effective aniline-perylene distance resulting from a Mulliken's approach is 3.61 Å.

  11. Carbon nanomaterial based electrochemical sensors for biogenic amines

    International Nuclear Information System (INIS)

    Yang, Xiao; He, Xiulan; Li, Fangping; Fei, Junjie; Feng, Bo; Ding, Yonglan

    2013-01-01

    This review describes recent advances in the use of carbon nanomaterials for electroanalytical detection of biogenic amines (BAs). It starts with a short introduction into carbon nanomaterials such as carbon nanotubes, graphene, nanodiamonds, carbon nanofibers, fullerenes, and their composites. Next, electrochemical sensing schemes are discussed for various BAs including dopamine, serotonin, epinephrine, norepinephrine, tyramine, histamine and putrescine. Examples are then given for methods for simultaneous detection of various BAs. Finally, we discuss the current and future challenges of carbon nanomaterial-based electrochemical sensors for BAs. The review contains 175 references. (author)

  12. Pulmonary extraction of biogenic amines during septic shock

    International Nuclear Information System (INIS)

    Kerstein, M.D.; Kohler, J.; Gould, S.; Moseley, P.

    1982-01-01

    The effect of live Escherichia coli on the pulmonary extraction of the biogenic amines 14 C 5-hydroxytryptamine, (5-HT) and 3 H-epinephrine was investigated. The labeled isotopes were injected into a central venous catheter and collected from an aortic catheter. One hundred per cent of the labeled epinephrine was recovered in the control and septic state. Only 32.8 +/- 3.6% SEM of the 5-hydroxytryptamine was recovered before sepsis and 42.5 +/- 4.9% SEM after sepsis. During sepsis, mean arterial pressure fell to 58 mm Hg from 121 mm Hg. Pulmonary shunt increased from .7 +/- .05 SEM to .33 +/- .09 SEM

  13. The application experience of ethanol amine at KORI unit 4

    International Nuclear Information System (INIS)

    Lee, Sang-hak; Park, Jong-il; Lee, Jae-won; Kim, Guem-Soo

    2004-01-01

    The secondary system water chemistry in the KORI PWR units has been well controlled by reducing the corrosion in the tubes of the steam generators; the pH agent has been changing from ammonia to ethanol amine (ETA) (1.8 to 2.0 ppm). For example, the iron concentration in the system was reduced by 40 to 70% compared with ammonia treatment. The paper presents the detailed information, such as ETA injection concentration and the variation of pH, concentration of organic acid products, and irons in the system, and a significant change on sludge after ETA application. (S. Ohno)

  14. Identification of Bearing Failure Using Signal Vibrations

    Science.gov (United States)

    Yani, Irsyadi; Resti, Yulia; Burlian, Firmansyah

    2018-04-01

    Vibration analysis can be used to identify damage to mechanical systems such as journal bearings. Identification of failure can be done by observing the resulting vibration spectrum by measuring the vibration signal occurring in a mechanical system Bearing is one of the engine elements commonly used in mechanical systems. The main purpose of this research is to monitor the bearing condition and to identify bearing failure on a mechanical system by observing the resulting vibration. Data collection techniques based on recordings of sound caused by the vibration of the mechanical system were used in this study, then created a database system based bearing failure due to vibration signal recording sounds on a mechanical system The next step is to group the bearing damage by type based on the databases obtained. The results show the percentage of success in identifying bearing damage is 98 %.

  15. A prototype construction of bearing heater system

    International Nuclear Information System (INIS)

    Firman Silitonga

    2007-01-01

    A bearing heater system has been successfully constructed using transformer-like method of 1000 VA power, 220 V primary voltage, and 50 Hz electrical frequency. The bearing heater consists of primary coil 230 turns, U type and bar-type iron core with 36 cm 2 , 9 cm 2 ,and 3 cm 2 cross-section, and electrical isolation. The bearing heater is used to enlarge the diameter of the bearing so that it can be easily fixed on an electric motor shaft during replacement because the heating is conducted by treated the bearing as a secondary coil of a transformer. This bearing heater can be used for bearing with 3 and 6 cm of inner diameter and 12 cm of maximum outside diameter. (author)

  16. Noise of oil lubricated journal bearings

    International Nuclear Information System (INIS)

    Rho, Byoung Hoo; Kim, Kyung Woong

    2002-01-01

    The purpose of the paper is to provide a procedure to calculate the noise of oil lubricated journal bearings. To do this, the nonlinear transient analysis of rotor-bearing system including rotor imbalance is performed. Acoustical properties of the bearing are investigated through frequency analysis of the pressure fluctuation of the fluid film calculated from the nonlinear analysis. Furthermore, a transmission theory of plane waves on a boundary of the outer surface of the bearing is used to obtain the sound pressure level of the bearing. Results show that the sound pressure level of the bearing can be increased with the rotational speed of the rotor although the whirl amplitude of the rotor is decreased at high speed. Noise estimating procedures presented in this paper could be an aid in the evaluation and understanding of acoustical properties of oil lubricated journal bearings

  17. Genomic evidence of geographically widespread effect of gene flow from polar bears into brown bears.

    Science.gov (United States)

    Cahill, James A; Stirling, Ian; Kistler, Logan; Salamzade, Rauf; Ersmark, Erik; Fulton, Tara L; Stiller, Mathias; Green, Richard E; Shapiro, Beth

    2015-03-01

    Polar bears are an arctic, marine adapted species that is closely related to brown bears. Genome analyses have shown that polar bears are distinct and genetically homogeneous in comparison to brown bears. However, these analyses have also revealed a remarkable episode of polar bear gene flow into the population of brown bears that colonized the Admiralty, Baranof and Chichagof islands (ABC islands) of Alaska. Here, we present an analysis of data from a large panel of polar bear and brown bear genomes that includes brown bears from the ABC islands, the Alaskan mainland and Europe. Our results provide clear evidence that gene flow between the two species had a geographically wide impact, with polar bear DNA found within the genomes of brown bears living both on the ABC islands and in the Alaskan mainland. Intriguingly, while brown bear genomes contain up to 8.8% polar bear ancestry, polar bear genomes appear to be devoid of brown bear ancestry, suggesting the presence of a barrier to gene flow in that direction. © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  18. Development and Evaluation of Titanium Spacesuit Bearings

    Science.gov (United States)

    Rhodes, Richard; Battisti, Brian; Ytuarte, Raymond, Jr.; Schultz, Bradley

    2016-01-01

    The Z-2 Prototype Planetary Extravehicular Space Suit Assembly is a continuation of NASA's Z-series of spacesuits, designed with the intent of meeting a wide variety of exploration mission objectives, including human exploration of the Martian surface. Incorporating titanium bearings into the Z-series space suit architecture allows us to reduce mass by an estimated 23 lbs per suit system compared to the previously used stainless steel bearing race designs, without compromising suit functionality. There are two obstacles to overcome when using titanium for a bearing race- 1) titanium is flammable when exposed to the oxygen wetted environment inside the space suit and 2) titanium's poor wear properties are often challenging to overcome in tribology applications. In order to evaluate the ignitability of a titanium space suit bearing, a series of tests were conducted at White Sands Test Facility (WSTF) that introduced the bearings to an extreme test profile, with multiple failures imbedded into the test bearings. The testing showed no signs of ignition in the most extreme test cases; however, substantial wear of the bearing races was observed. In order to design a bearing that can last an entire exploration mission (approx. 3 years), design parameters for maximum contact stress need to be identified. To identify these design parameters, bearing test rigs were developed that allow for the quick evaluation of various bearing ball loads, ball diameters, lubricants, and surface treatments. This test data will allow designers to minimize the titanium bearing mass for a specific material and lubricant combination and design around a cycle life requirement for an exploration mission. This paper reviews the current research and testing that has been performed on titanium bearing races to evaluate the use of such materials in an enriched oxygen environment and to optimize the bearing assembly mass and tribological properties to accommodate for the high bearing cycle life for an

  19. Les femmes et les enfants, prisonniers politiques ou déportés à titre préventif pendant la guerre civile grecque

    Directory of Open Access Journals (Sweden)

    Christina Alexopoulos

    2011-12-01

    Full Text Available Les conditions et stratégies de survie des milliers de femmes condamnées ou déportées de la guerre civile grecque permettent d'établir une typologie.Pendant la guerre civile grecque (1946-1949 des milliers de personnes sont emprisonnées, déportées dans des camps de concentration ou exilées dans des îles, une population hétéroclite d’hommes et de femmes, persécutés pour leurs idées, leurs origines ou même des liens de parenté avec les communistes. Dans la présente étude, nous nous intéresserons à un groupe lui-même peu homogène, les femmes et les enfants, prisonniers politiques ou déportés à titre préventif pendant le conflit. Après un bref rappel de la pratique de la déportation et une esquisse de typologie de la réclusion, nous étudierons les conditions de détention et les stratégies de survie des femmes, souvent emprisonnées avec leurs enfants, leur statut au sein des prisonniers politiques ainsi que le sens de l'engagement politique dans leur système de valeurs.During the Greek Civil War (1946-1949 thousands of persons were imprisoned, deported to concentration camps or exiled on the islands, a heteroclite population of men and women, persecuted for their ideas, their origins or even their association with the Communists. In the present study, we are interested in a not particularly homogeneous group of women and children, political prisoners or deportees who had been detained for preventive reasons during the conflict. Following a brief summary of the practice of deportation and a typological sketch of the imprisonment, we shall study the detention conditions and the survival strategies of the women, often imprisoned with their children, their status vis-à-vis the political prisoners as well as the meaning of political commitment in their value system.

  20. Effect of pendant isophthalic acid moieties on the adsorption properties of light hydrocarbons in HKUST-1-like tbo -MOFs: Application to methane purification and storage

    KAUST Repository

    Belmabkhout, Youssef

    2014-01-01

    Equilibrium adsorption of methane (CH4), C2+ gases (ethane (C2H6), ethylene (C2H4), propane (C3H8), and propylene (C3H6)), and carbon dioxide (CO2) was measured on a series of tbo-MOFs (topological analogues of the prototypical MOF, HKUST-1, correspondingly dubbed tbo-MOF-1), which were developed via the supermolecular building layer (SBL) pillaring strategy. Specifically, tbo-MOF-2 and its isoreticular, functionalized analogue, tbo-MOF-2-{CH2O[Ph(CO2H)2]}2 (or tbo-MOF-3), which is characterized by pendant isophthalic acid moieties freely pointing into the cavities, were evaluated on the basis of potential use in methane storage and C2+/CH4 separation. The parent, tbo-MOF-2, showed high gravimetric and volumetric CH4 uptake, close to the U.S. Department of Energy (DOE) target for methane storage at 35 bar and room temperature. Though the presence of the pendant isophthalic acid moiety in the analogous compound, tbo-MOF-3, led to a decrease in total CH4 uptake, due mainly to the reduced size of the cavities, interestingly, it increased the affinity of the SBL-based tbo-MOF platform for propane, propene, ethane, and ethylene at low pressures compared with CH4, due additionally to the enhanced interactions of the highly polarizable light hydrocarbons with the isophthalic acid moiety. Using Ideal Adsorption Solution Theory (IAST), the predicted mixture adsorption equilibria for the C3H8/CH4, C3H6/CH4, C2H6/CH4, C2H4/CH4, and C3H8/CO2 systems showed high adsorption selectivity for C2+ over methane for tbo-MOF-3 compared with tbo-MOF-2. The high working storage capacity of tbo-MOF-2 and the high affinity of tbo-MOF-3 for C2+ over CH4 and CO2 make tbo-MOF an ideal platform for studies in gas storage and separation.

  1. Conditioning of alpha bearing wastes

    International Nuclear Information System (INIS)

    1991-01-01

    Alpha bearing wastes are generated during the reprocessing of spent fuel, mixed oxide fuel fabrication, decommissioning and other activities. The safe and effective management of these wastes is of particular importance owing to the radiotoxicity and long lived characteristics of certain transuranic (TRU) elements. The management of alpha bearing wastes involves a number of stages which include collection, characterization, segregation, treatment, conditioning, transport, storage and disposal. This report describes the currently available matrices and technologies for the conditioning of alpha wastes and relates them to their compatibility with the other stages of the waste management process. The selection of a specific immobilization process is dependent on the waste treatment state and the subsequent handling, transport, storage and disposal requirements. The overall objectives of immobilization are similar for all waste producers and processors, which are to produce: (a) Waste forms with sufficient mechanical, physical and chemical stability to satisfy all stages of handling, transport and storage (referred to as the short term requirements), and (b) Waste forms which will satisfy disposal requirements and inhibit the release of radionuclides to the biosphere (referred to as the long term requirements). Cement and bitumen processes have already been successfully applied to alpha waste conditioning on the industrial scale in many of the IAEA Member States. Cement systems based on BFS and pozzolanic cements have emerged as the principal encapsulation matrices for the full range of alpha bearing wastes. Alternative technologies, such as polymers and ceramics, are being developed for specific waste streams but are unlikely to meet widespread application owing to cost and process complexity. The merits of alpha waste conditioning are improved performance in transport, storage and disposal combined with enhanced public perception of waste management operations. These

  2. Extraction of beryllium sulfate by a long chain amine; Extraction du sulfate de beryllium par une amine a longue chaine

    Energy Technology Data Exchange (ETDEWEB)

    Etaix, E S [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1968-06-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [French] L'etude de l'extraction de l'acide sulfurique en solution aqueuse par une amine primaire en solution dans le benzene, le diethyl-3,9 amino-6 tridecane (D.E.T.) - autre nom americain 1-3 (ethylpentyl) - 4-ethyloctylamine (E.P.O.) a permis de calculer les constantes de formation du sulfate et de l'hydrogenosulfate d'alkyl-ammonium. La formule du complexe de sulfate de beryllium et d'alkyl-ammonium forme en solution benzenique a ete ensuite determinee pour diverses acidites initiales de la solution aqueuse. Enfin, l'influence de la concentration des ions sulfate de la phase aqueuse sur l'extraction du beryllium a mis en evidence la formation en solution aqueuse de complexes anioniques de sulfate et de beryllium dont la constante de formation a ete evaluee. (auteur)

  3. Extraction of beryllium sulfate by a long chain amine; Extraction du sulfate de beryllium par une amine a longue chaine

    Energy Technology Data Exchange (ETDEWEB)

    Etaix, E.S. [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1968-06-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [French] L'etude de l'extraction de l'acide sulfurique en solution aqueuse par une amine primaire en solution dans le benzene, le diethyl-3,9 amino-6 tridecane (D.E.T.) - autre nom americain 1-3 (ethylpentyl) - 4-ethyloctylamine (E.P.O.) a permis de calculer les constantes de formation du sulfate et de l'hydrogenosulfate d'alkyl-ammonium. La formule du complexe de sulfate de beryllium et d'alkyl-ammonium forme en solution benzenique a ete ensuite determinee pour diverses acidites initiales de la solution aqueuse. Enfin, l'influence de la concentration des ions sulfate de la phase aqueuse sur l'extraction du beryllium a mis en evidence la formation en solution aqueuse de complexes anioniques de sulfate et de beryllium dont la constante de formation a ete evaluee. (auteur)

  4. Factors Influencing Biogenic Amines Accumulation in Dairy Products

    Science.gov (United States)

    Linares, Daniel M.; del Río, Beatriz; Ladero, Victor; Martínez, Noelia; Fernández, María; Martín, María Cruz; Álvarez, Miguel A.

    2012-01-01

    Fermented foods are among the food products more often complained of having caused episodes of biogenic amines (BA) poisoning. Concerning milk-based fermented foods, cheese is the main product likely to contain potentially harmful levels of BA, specially tyramine, histamine, and putrescine. Prompted by the increasing awareness of the risks related to dietary uptake of high biogenic amine loads, in this review we report all those elaboration and processing technological aspects affecting BA biosynthesis and accumulation in dairy foods. Improved knowledge of the factors involved in the synthesis and accumulation of BA should lead to a reduction in their incidence in milk products. Synthesis of BA is possible only when three conditions converge: (i) availability of the substrate amino acids; (ii) presence of microorganisms with the appropriate catabolic pathway activated; and (iii) environmental conditions favorable to the decarboxylation activity. These conditions depend on several factors such as milk treatment (pasteurization), use of starter cultures, NaCl concentration, time, and temperature of ripening and preservation, pH, temperature, or post-ripening technological processes, which will be discussed in this chapter. PMID:22783233

  5. Analysis of irradiated biogenic amines by computational chemistry and spectroscopy

    International Nuclear Information System (INIS)

    Oliveira, Jorge L.S.P.; Borges Junior, Itamar; Cardozo, Monique; Souza, Stefania P.; Lima, Antonio L.S.; Lima, Keila S.C.

    2011-01-01

    Biogenic Amines (B A) are nitrogenous compounds able to cause food poisoning. In this work, we studied the tyramine, one of the most common BA present in foods by combining experimental measured IR (Infrared) and GC/MS (Gas Chromatograph / Mass Spectrometry) spectra and computational quantum chemistry. Density Functional Theory (DFT) and the Deformed Atoms in Molecules (DMA) method was used to compute the partition the electronic densities in a chemically-intuitive way and electrostatic potentials of molecule to identify the acid and basic sites. Trading pattern was irradiated using a Cs 137 radiator, and each sample was identified by IR and GC/MS. Calculated and experimental IR spectra were compared. We observed that ionizing gamma irradiation was very effective in decreasing the population of standard amine, resulting in fragments that could be rationalized through the quantum chemistry calculations. In particular, we could locate the acid and basic sites of both molecules and identify possible sites of structural weaknesses, which allowed to propose mechanistic schemes for the breaking of chemical bonds by the irradiation. Moreover, from this work we hope it will be also possible to properly choose the dose of gamma irradiation which should be provided to eliminate each type of contamination. (author)

  6. Novel primary amine diazeniumdiolates-Chemical and biological characterization.

    Science.gov (United States)

    Puglisi, Melany P; Bradaric, Michael J; Pontikis, John; Cabai, Jonathan; Weyna, Theodore; Tednes, Patrick; Schretzman, Robert; Rickert, Karl; Cao, Zhao; Andrei, Daniela

    2018-05-02

    Hit, Lead & Candidate Discovery Diazeniumdiolates, also known as NONOates, are extensively used in biochemical, physiological, and pharmacological studies due to their ability to release nitric oxide (NO . ) and/or their congeneric nitroxyl (HNO). The purpose of this work was to synthesize a series of primary amine-based diazeniumdiolates as HNO/NO donors and to determine their efficacy as anticancer and antifungal agents in vivo. The seven compounds (3a-3g) were successfully synthesized and characterized, one of which had been previously reported in the literature (3g). Two compounds showed anti-proliferative effects against ovarian (ES2 and SKOV3) and AML monocyte-derived cancer cells (THP-1) when tested with standard MTT assays. Compounds 3a and 3g demonstrated reduced ovarian cancer cell proliferation when treated at doses from 0.033 to 1.0 mg/mL at the 24 hr time point. These compounds also exhibited moderate and selective antifungal activity against Fusarium oxysporum f.sp. lycopersici, one cause of opportunistic infections of immunocompromised patients, inhibiting the growth of the fungi at LD 50 at 10 mg/mL. A third compound (3e) did not exhibit similar activities, possibly due to the alkyl chain. Our results suggest that the primary amine diazeniumdiolates may offer a versatile platform for the development of HNO/NO donors for biomedical applications. © 2018 Wiley Periodicals, Inc.

  7. Technological factors affecting biogenic amine content in foods: a review

    Directory of Open Access Journals (Sweden)

    Fausto Gardini

    2016-08-01

    Full Text Available Biogenic amines (BAs are molecules which can be present in foods and, due to their toxicity, can cause adverse effects on the consumers. BAs are generally produced by microbial decarboxylation of amino acids in food products. The most significant BAs occurring in foods are histamine, tyramine, putrescine, cadaverine, tryptamine, 2-phenylethylamine, spermine, spermidine and agmatine. The importance of preventing the excessive accumulation of BAs in food is related to their impact on human health and food quality. Quality criteria in connection with the presence of BAs in food and food products are necessary from a toxicological point of view. This is particularly important in fermented foods in which the massive microbial proliferation required for obtaining specific products is often relater with BA accumulation. In this review, up-to-date information and recent discoveries about technological factors affecting biogenic amine content in foods are reviewed. Specifically, BA forming-microorganism and decarboxylation activity, genetic and metabolic organization of decarboxylases, risk associated to BAs (histamine, tyramine toxicity and other BAs, environmental factors influencing BA formation (temperature, salt concentration, pH. In addition, the technological factors for controlling BA production (use of starter culture, technological additives, effects of packaging, other non-thermal treatments, metabolising BA by microorganisms, effects of pressure treatments on BA formation and antimicrobial substances are addressed.

  8. Amine-oxide hybrid materials for acid gas separations

    KAUST Repository

    Bollini, Praveen

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams. In particular, these materials are being extensively studied for the adsorption of CO 2 from simulated flue gas streams, with an eye towards utilizing these materials as part of a post-combustion carbon capture process at large flue gas producing installations, such as coal-fired electricity-generating power plants. In this Application Article, the utilization of amine-modified organic-inorganic hybrid materials is discussed, focusing on important attributes of the materials, such as (i) CO 2 adsorption capacities, (ii) adsorption and desorption kinetics, and (iii) material stability, that will determine if these materials may one day be useful adsorbents in practical CO 2 capture applications. Specific research needs and limitations associated with the current body of work are identified. © 2011 The Royal Society of Chemistry.

  9. Palladium-catalysed anti-Markovnikov selective oxidative amination

    Science.gov (United States)

    Kohler, Daniel G.; Gockel, Samuel N.; Kennemur, Jennifer L.; Waller, Peter J.; Hull, Kami L.

    2018-03-01

    In recent years, the synthesis of amines and other nitrogen-containing motifs has been a major area of research in organic chemistry because they are widely represented in biologically active molecules. Current strategies rely on a multistep approach and require one reactant to be activated prior to the carbon-nitrogen bond formation. This leads to a reaction inefficiency and functional group intolerance. As such, a general approach to the synthesis of nitrogen-containing compounds from readily available and benign starting materials is highly desirable. Here we present a palladium-catalysed oxidative amination reaction in which the addition of the nitrogen occurs at the less-substituted carbon of a double bond, in what is known as anti-Markovnikov selectivity. Alkenes are shown to react with imides in the presence of a palladate catalyst to generate the terminal imide through trans-aminopalladation. Subsequently, olefin isomerization occurs to afford the thermodynamically favoured products. Both the scope of the transformation and mechanistic investigations are reported.

  10. Comparison of Alignment Correction Angles Between Fixed-Bearing and Mobile-Bearing UKA.

    Science.gov (United States)

    Inoue, Atsuo; Arai, Yuji; Nakagawa, Shuji; Inoue, Hiroaki; Yamazoe, Shoichi; Kubo, Toshikazu

    2016-01-01

    Good outcomes have been reported with both fixed-bearing and mobile-bearing unicompartmental knee arthroplasty (UKA). However, overcorrected alignment could induce the progression of arthritis on the non-arthroplasty side. Changes of limb alignment after UKA with both types of bearings (fixed bearing: 24 knees, mobile bearing: 28 knees) were investigated. The mean difference between the preoperative standing femoral-tibial angle (FTA) and postoperative standing FTA was significantly larger in mobile bearing UKA group. In fixed-bearing UKA, there must be some laxity in MCL tension so that a 2-mm tension gauge can be inserted. In mobile-bearing UKA, appropriate MCL tension is needed to prevent bearing dislocation. This difference in MCL tension may have caused the difference in the correction angle between the groups. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Seismic isolation rubber bearings for nuclear facilities

    International Nuclear Information System (INIS)

    Fujita, Takafumi

    1991-01-01

    This paper describes results of biaxial breaking tests by compression and shear and by tension and shear for seismic isolation rubber bearings with bolted-type connections. The bearings used in the tests were low-damping rubber bearings, high-damping rubber bearings, and lead-rubber bearings. Three modes of failure of the bolted-type bearings were observed in the tests. They are the breaking failure by tension and shear; the breaking failure by compression and shear; and the buckling failure by compression and shear. The first and the second modes of failures are almost independent of the types and the sizes of the bearings. The breaking conditions of those failure modes are described in the axial-stress-shear-strain plane. This expression is useful for the evaluation of safety margins of the bearings. The paper outlines the basic design of the nuclear-grade bearings which were used for large-scale rubber bearing tests in a research project for seismic isolation of FBR plants. It also discusses the protection method against aging and the quality control which are important for implementation. (orig./HP)

  12. Seismic isolation rubber bearings for nuclear facilities

    International Nuclear Information System (INIS)

    Fujita, Takafumi

    1989-01-01

    This paper describes results of biaxial breaking tests by compression and shear and by tension and shear for seismic isolation rubber bearings with bolted-type connections. The bearings used in the tests were low-damping rubber bearings, high-damping rubber bearings, and lead-rubber bearings. Three modes of failure of the bolted-type bearings were observed in the tests. They are the breaking failure by tension and shear; the breaking failure by compression and shear; and the buckling failure by compression and shear. The first and the second modes of failures are almost independent of the types and the sizes of the bearings. The breaking conditions of those failure modes are described in the axial stress-shear strain plane. This expression is useful for the evaluation of safety margins of the bearings. The paper outlines the basic design of the nuclear-grade bearings which were used for large-scale rubber bearing tests in a research project for seismic isolation of fast breeder reactor (FBR) plants. The paper also discusses the protection method against aging and the quality control which are important for implementation

  13. Reduction-Induced Cyclization and Redox Reactions of Fully Methylated Titanocene Dichlorides Bearing Pendant Alkenyldimethylsilyl Groups, [TiCl2{.eta.5-C5Me4(SiMe2R)}2] (R=Vinyl, and Allyl)

    Czech Academy of Sciences Publication Activity Database

    Lukešová, Lenka; Štěpnička, P.; Fejfarová, K.; Gyepes, R.; Císařová, I.; Horáček, Michal; Kubišta, Jiří; Mach, Karel

    2002-01-01

    Roč. 21, - (2002), s. 2639-2653 ISSN 0276-7333 R&D Projects: GA AV ČR IAA4040004; GA ČR GA203/02/0436 Institutional research plan: CEZ:AV0Z4040901 Keywords : titanocene * reduction-induced * dichlorides Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.215, year: 2002

  14. Diazotisation of Weakly Basic Aromatic and Heterocyclic Amines in Strongly Acid Media

    Science.gov (United States)

    Godovikova, Tamara I.; Rakitin, Oleg A.; Khmel'nitskii, Lenor I.

    1983-05-01

    The review is devoted to the diazotisation of weakly basic aromatic amines. The methods of synthesis of diazonium salts based on these amines by non-traditional methods are examined. Data on the mechanism of the diazotisation reaction in strongly acid media are surveyed. Reactions of diazonium salts leading to the synthesis of new compounds are presented. The bibliography includes 75 references.

  15. Nucleophilic addition of amines to the activated ethylene bond in non-aqueous media

    International Nuclear Information System (INIS)

    Perepichka, Igor F.; Popov, Anatolii F.

    1995-01-01

    The kinetics of addition of a number of primary and secondary aliphatic amines to trans-(2-furyl) nitro ethylene (1) has been studied in solvents of various polarities (from acetonitrile, ε 37.5, to heptane, ε 1.89). It has been shown that the reaction is catalysed both by the amine reagent and by tertiary amines. On the basis of analyzing the observed kinetic regularities a stepwise reaction mechanism has been proposed which involves formation of zwitterionic intermediate (3) at the first equilibrium step (k 1 , K 1 ) which is then converted into the reaction product by means of proton transfer in parallel routes, the non-catalytic one (k 2 ) and that catalysed by the initial (K 3 ) or tertiary (K 4 ) amine. The observed high values of the deuterium isotope effects in the reaction (K H /K D ∼ 2.3 - 8.9) confirm that proton transfer occurs in the rate-limiting step of the reaction (primary kinetic isotope effect). The third order by amine kinetic route is observed in low polar media which is due to participation of amine dimers (R 2 NH HNR 2 ) in the reaction. The observed kinetic regularities are compared with those for the nucleophilic aromatic substitution reactions in low-polar media, and the conclusion has been made that the reaction route of the third order by amine proceeds as reversible nucleophilic attack by amine dimer and following base-catalysed transformation of the intermediate into the product. (author)

  16. Copper-Catalyzed Electrophilic Amination of Organoaluminum Nucleophiles with O-Benzoyl Hydroxylamines.

    Science.gov (United States)

    Zhou, Shuangliu; Yang, Zhiyong; Chen, Xu; Li, Yimei; Zhang, Lijun; Fang, Hong; Wang, Wei; Zhu, Xiancui; Wang, Shaowu

    2015-06-19

    A copper-catalyzed electrophilic amination of aryl and heteroaryl aluminums with N,N-dialkyl-O-benzoyl hydroxylamines that affords the corresponding anilines in good yields has been developed. The catalytic reaction proceeds very smoothly under mild conditions and exhibits good substrate scope. Moreover, the developed catalytic system is also well suited for heteroaryl aluminum nucleophiles, providing facile access to heteroaryl amines.

  17. Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes

    Science.gov (United States)

    Seral-Ascaso, A.; Metel, S.; Pokle, A.; Backes, C.; Zhang, C. J.; Nerl, H. C.; Rode, K.; Berner, N. C.; Downing, C.; McEvoy, N.; Muñoz, E.; Harvey, A.; Gholamvand, Z.; Duesberg, G. S.; Coleman, J. N.; Nicolosi, V.

    2016-06-01

    We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01663d

  18. Development of a GC-MS-SPME Method for the Determination of Amines in Meteorites

    Science.gov (United States)

    Hilts, R. W.; Skelhorne, A. W.; Simkus, D.; Herd, C. D. K.

    2016-08-01

    A GC-MS-SPME analytical method for the direct determination of amines in aqueous solution has been developed. The key step in the procedure is the conversion of the amines into their non-volatile ammonium salts by protonation with HCl.

  19. N-heterocyclic carbene copper(I) catalysed N-methylation of amines using CO2

    KAUST Repository

    Santoro, Orlando

    2015-09-30

    The N-methylation of amines using CO2 and PhSiH3 as source of CH3 was efficiently performed using a N-heterocyclic carbene copper(I) complex. The methodology was found compatible with aromatic and aliphatic primary and secondary amines. Synthetic and computational studies have been carried out to support the proposed reaction mechanism for this transformation.

  20. Amine metabolism in the human brain : evaluation of the probenecid test

    NARCIS (Netherlands)

    Korf, Jacob

    1971-01-01

    There are indirect indications, that biogenic amines in the brain are concerned with pathological states such as depression (serotonin, 5HT and noradrenaline, NA) and Parkonsonism (dopamine, DA). These indications were obtained from measurements of amines and their metabolites in pe - ripheral

  1. Biogenic amine content, histamine-forming bacteria, and adulteration of pork in tuna sausage products.

    Science.gov (United States)

    Kung, Hsien-Feng; Tsai, Yung-Hsiang; Chang, Shih-Chih; Hong, Tang-Yao

    2012-10-01

    Twenty-five tuna sausage products were purchased from retail markets in Taiwan. The rates of occurrence of biogenic amines, histamine-forming bacteria, and adulteration by pork and poultry were determined. The average content of various biogenic amines in all tested samples was less than 2.0 mg/100 g (Makaira nigricans (blue marlin).

  2. Renewable glycolaldehyde isolation from pyrolysis oil-derived aqueous solution by reactive extraction with primary amines

    NARCIS (Netherlands)

    Vitasari, C.R.; Meindersma, G.W.; Haan, de A.B.

    2012-01-01

    Glycolaldehyde can be separated from a pyrolysis oil-derived aqueous phase by reactive extraction employing primary amines dissolved in organic diluents. This work investigates the occurrence of solid imine formation from glycolaldehyde and amines and the competitive reactions in the organic extract

  3. Amine-terminated silicon nanoparticles: synthesis, optical properties and their use in bioimaging

    NARCIS (Netherlands)

    Rosso-Vasic, M.; Spruijt, E.; Popovic, Z.; Overgaag, K.; Lagen, van B.; Grandidier, B.; Vanmaekelbergh, D.; Domínguez-Gutiérrez, D.; Cola, de L.; Zuilhof, H.

    2009-01-01

    Very stable and bright emitting amine-terminated Si nanoparticles (NPs) with different alkyl chain lengths between the Si core and amine end-group are synthesized. The obtained NPs have a spherical shape and homogeneous size distribution (1.57 ± 0.24 nm). Their emission can be tuned from the UV to

  4. Extension of the cubic-plus-association (CPA) equation of state to amines

    DEFF Research Database (Denmark)

    Kaarsholm, Mads Kristian; Derawi, Samer; Michelsen, Michael Locht

    2005-01-01

    The cubic-plus-association (CPA) equation of state has been extended to modeling mixtures containing amines. Special focus was given to primary and secondary amines, which are known to self-associate, thus forming hydrogen bonds in mixtures with alkanes. Pure-compound parameters have been determi...

  5. Elaboration and characterisation of acids catalyst for the obtention of amines

    International Nuclear Information System (INIS)

    Khemaissia, S.; Zaoui, B.; Nibou, D.

    1997-04-01

    The nuclear energy has shown the interest of aminated substances as solvents for removal and purification. These extractants are generally used in uranium ores treatment processes and several technology fields, specially, in organic and pharmaceutical industries. The present work deals with elaboration and characterization of acidic solid catalyst used in aminated extractants obtaining

  6. Industrial Process Design for the Production of Aniline by Direct Amination

    NARCIS (Netherlands)

    Driessen, Rick T.; Kamphuis, Peter; Mathijssen, Lydwien; Zhang, Ruo; van der Ham, Louis G.J.; van den Berg, Henk; Zeeuw, Arend Jan

    2017-01-01

    The objective is to design a plant from raw material to product for the production of aniline by direct amination of benzene. The process design is started on a conceptual level and ended on a basic engineering level as well as a techno-economical evaluation. The amination of benzene by

  7. Mastocytosis and adverse reactions to biogenic amines and histamine-releasing foods : what is the evidence?

    NARCIS (Netherlands)

    Viieg-Boerstra, BJ; van der Heide, S; Elberink, JNGO; Kluin-Nelemans, JC; Dubois, AEJ

    2005-01-01

    Background: It has been suggested that normal concentrations of biogenic amines and 'histamine-releasing foods' may exacerbate symptoms in mastocytosis. The purpose of this study was to look for scientific evidence in the literature on diets restricted in biogenic amines and histamine-releasing

  8. Mechanistic investigation of the iridium-catalysed alkylation of amines with alcohols

    DEFF Research Database (Denmark)

    Fristrup, Peter; Tursky, Matyas; Madsen, Robert

    2012-01-01

    where the intermediate aldehyde stays coordinated to the iridium catalyst and reacts with the amine to give a hemiaminal which is also bound to the catalyst. Dehydration to the imine and reduction to the product amine also takes place without breaking the coordination to the catalyst. The fact...

  9. N-formylation of amines via the aerobic oxidation of methanol over supported gold nanoparticles.

    Science.gov (United States)

    Ishida, Tamao; Haruta, Masatake

    2009-01-01

    Dress code: formyl. Gold nanoparticles supported on NiO catalyze the one-pot N-formylation of amines with methanol and molecular oxygen to produce formamide at a selectivity of 90 %. This process generates methyl formate in situ, followed by reaction with amines.

  10. Inhibition of Microbial Growth by Fatty Amine Catalysts from Polyurethane Foam Test Tube Plugs

    Science.gov (United States)

    Bach, John A.; Wnuk, Richard J.; Martin, Delano G.

    1975-01-01

    When polyurethane foam test tube plugs are autoclaved, they release volatile fatty amines that inhibit the growth of some microorganisms. The chemical structures of these amines were determined by the use of a gas chromatographmass spectrometer. They are catalysts used to produce the foam. The problem of contaminating growth media with toxic substances released from polymeric materials is discussed. PMID:1096816

  11. N-heterocyclic carbene copper(I) catalysed N-methylation of amines using CO2

    KAUST Repository

    Santoro, Orlando; Lazreg, Faï ma; Minenkov, Yury; Cavallo, Luigi; Cazin, Catherine S. J.

    2015-01-01

    The N-methylation of amines using CO2 and PhSiH3 as source of CH3 was efficiently performed using a N-heterocyclic carbene copper(I) complex. The methodology was found compatible with aromatic and aliphatic primary and secondary amines. Synthetic and computational studies have been carried out to support the proposed reaction mechanism for this transformation.

  12. Enhanced reactivities toward amines by introducing an imine arm to the pincer ligand: Direct coupling of two amines to form an imine without oxidant

    KAUST Repository

    He, Lipeng

    2012-07-23

    Dehydrogenative homocoupling of primary alcohols to form esters and coupling of amines to form imines was accomplished using a class of novel pincer ruthenium complexes. The reactivities of the ruthenium pincer complexes for the direct coupling of amines to form imines were enhanced by introducing an imine arm to the pincer ligand. Selective oxidation of benzylamines to imines was achieved using aniline derivatives as the substrate and solvent. © 2012 American Chemical Society.

  13. Thermodynamic study of (heptane + amine) mixtures. III: Excess and partial molar volumes in mixtures with secondary, tertiary, and cyclic amines at 298.15 K

    International Nuclear Information System (INIS)

    Lepori, Luciano; Gianni, Paolo; Spanedda, Andrea; Matteoli, Enrico

    2011-01-01

    Graphical abstract: Highlights: → Excess volumes of (sec., tert., or cyclic amines + heptane) mixtures. → Excess volumes are positive for small size amines and decrease as the size increases. → Group contributions to predict the partial molar volumes of amines in heptane. → The void volume is larger for sec. and tert. than for linear amines in heptane. → The void volume is much smaller for cyclic than for linear amines in heptane. - Abstract: Excess molar volumes V E at 298.15 K were determined by means of a vibrating tube densimeter for binary mixtures of {heptane + open chain secondary (diethyl to dibutyl) and tertiary (triethyl to tripentyl) amines} as well as for cyclic imines (C 2 , C 3 , C 4 , C 6 , and C 7 ) and primary cycloalkylamines (C 5 , C 6 , C 7 , and C 12 ). The V E values were found positive for mixtures involving small size amines, with V E decreasing as the size increases. Negative V E 's were found for tributyl- and tripentylamine, heptamethylenimine, and cyclododecylamine. Mixtures of heptane with cycloheptylamine showed an s-shaped curve. Partial molar volumes V 0 of amines at infinite dilution in heptane were obtained from V E and compared with V 0 of hydrocarbons and other classes of organic compounds taken from literature. An additivity scheme, based on the intrinsic volume approach, was applied to estimate group (CH 3 , CH 2 , CH, C, NH 2 , NH, N, OH, O, CO, and COO) contributions to V 0 . These contributions, the effect of cyclization on V 0 , and the limiting slope of the apparent excess molar volumes were discussed in terms of solute-solvent and solute-solute interactions.

  14. Enhanced reactivities toward amines by introducing an imine arm to the pincer ligand: Direct coupling of two amines to form an imine without oxidant

    KAUST Repository

    He, Lipeng; Chen, Tao; Gong, Dirong; Lai, Zhiping; Huang, Kuo-Wei

    2012-01-01

    Dehydrogenative homocoupling of primary alcohols to form esters and coupling of amines to form imines was accomplished using a class of novel pincer ruthenium complexes. The reactivities of the ruthenium pincer complexes for the direct coupling of amines to form imines were enhanced by introducing an imine arm to the pincer ligand. Selective oxidation of benzylamines to imines was achieved using aniline derivatives as the substrate and solvent. © 2012 American Chemical Society.

  15. Post-synthesis amine borane functionalization of metal-organic framework and its unusual chemical hydrogen release phenomenon

    KAUST Repository

    Berke, Heinz; Barman, Smair; Remhof, Arndt; Koitz, Ralph; Iannuzzi, Marcella; Blacque, Olivier; Yan, Yigang; Fox, Thomas; Hutter, Jü rg; Zü ttel, Andreas

    2017-01-01

    We report a novel strategy for post-synthesis amine borane functionalization of MOFs under gas-solid phase transformation utilizing gaseous diborane. The covalently confined amine borane derivative decorated on the framework backbone is stable when

  16. A review of bear farming and bear trade in Lao People's Democratic Republic

    Directory of Open Access Journals (Sweden)

    E. Livingstone

    2018-01-01

    Full Text Available This study reviews the bear farming industry in Lao PDR with the objective of documenting the current number of commercial bear facilities (i.e. captive bear facilities judged to be trading in bear bile and/or bears and bear parts and the number of bears contained within these facilities, noting changes since it was last examined between 2000 and 2012 by Livingstone and Shepherd (2014. We surveyed all known commercial bear facilities and searched for previously unrecorded facilities. We compared our records with Livingstone and Shepherd (2014 and corrected some duplicate records from their study. In 2017, we recorded seven commercial facilities; four dedicated bear farms, and three tiger farms that were reportedly also keeping bears. We found that between 2012 and 2017 the recorded number of dedicated bear farms reduced by two, and the recorded number of tiger farms also keeping bears increased by one. Within the same period, the total number of captive bears among all facilities in Lao PDR hardly changed (+one, but the number of bears within each facility did. The northern facilities, owned by ethnic Chinese, have expanded since 2012, and central and southern facilities have downsized or closed. While bear farming appears to be downsizing in Lao PDR overall, efforts to phase it out are undermined by the expansion of foreign owned facilities in the north, within Special and Specific Economic Zones that largely cater to a Chinese market, and where the Lao government's efforts to enforce laws and protect wildlife appear to be lacking. Closing the facilities in the north will require political will and decisive law enforcement. Keywords: Bear farms, Bear bile, Gall bladder, Urso-deoxycholic acid, Bear bile extraction facilities, Lao PDR, Ursus thibetanus

  17. Application of ultraviolet, ozone, and advanced oxidation treatments to washwaters to destroy nitrosamines, nitramines, amines, and aldehydes formed during amine-based carbon capture.

    Science.gov (United States)

    Shah, Amisha D; Dai, Ning; Mitch, William A

    2013-03-19

    Although amine-based CO(2) absorption is a leading contender for full-scale postcombustion CO(2) capture at power plants, concerns have been raised about the potential release of carcinogenic N-nitrosamines and N-nitramines formed by reaction of exhaust gas NO(x) with the amines. Experiments with a laboratory-scale pilot unit suggested that washwater units meant to scrub contaminants from absorber unit exhaust could potentially serve as a source of N-nitrosamines via reactions of residual NO(x) with amines accumulating in the washwater. Dosage requirements for the continuous treatment of the washwater recycle line with ultraviolet (UV) light for destruction of N-nitrosamines and N-nitramines, and with ozone or hydroxyl radical-based advanced oxidation processes (AOPs) for destruction of amines and aldehydes, were evaluated. Although amine destruction. Ozone achieved 90% amine removal in washwaters at 5-12 molar excess of ozone, indicating transferred dosage levels of ∼100 mg/L for 90% removal in a first-stage washwater unit, but likely only ∼10 mg/L if applied to a second-stage washwater. Accurate dosage and cost estimates would require pilot testing to capture synergies between UV and ozone treatments.

  18. Study of sulfonated polyether ether ketone with pendant lithiated fluorinated sulfonic groups as ion conductive binder in lithium-ion batteries

    Science.gov (United States)

    Wei, Zengbin; Xue, Lixin; Nie, Feng; Sheng, Jianfang; Shi, Qianru; Zhao, Xiulan

    2014-06-01

    In an attempt to reduce the Li+ concentration polarization and electrolyte depletion from the electrode porous space, sulfonated polyether ether ketone with pendant lithiated fluorinated sulfonic groups (SPEEK-FSA-Li) is prepared and attempted as ionic conductivity binder. Sulfonated aromatic poly(ether ether ketone) exhibits strong adhesion and chemical stability, and lithiated fluorinated sulfonic side chains help to enhance the ionic conductivity and Li+ ion diffusion due to the charge delocalization over the sulfonic chain. The performances are evaluated by cyclic voltammetry, electrochemical impedance spectroscopy, charge-discharge cycle testing, 180° peel testing, and compared with the cathode prepared with polyvinylidene fluoride binder. The electrode prepared with SPEEK-FSA-Li binder forms the relatively smaller resistances of both the SEI and the charge transfer of lithium ion transport. This is beneficial to lithium ion intercalation and de-intercalation of the cathode during discharging-charging, therefore the cell prepared with SPEEK-FSA-Li shows lower charge plateau potential and higher discharge plateau potential. Compared with PVDF, the electrode with ionic binder shows smaller decrease in capacity with the increasing of cycle rate. Meanwhile, adhesion strength of electrode prepared with SPEEK-FSA-Li is more than five times greater than that with PVDF.

  19. After Arizona: Military Musicians in the Second World War Après Arizona: les musiciens dans la marine américaine pendant la Seconde Guerre mondiale

    Directory of Open Access Journals (Sweden)

    Rosemary Peters

    2012-03-01

    Full Text Available Cet article traite du rôle des musiciens dans la marine américaine pendant la Seconde Guerre mondiale. L’histoire de l’USS Arizona — et de son orchestre, noyé avec le cuirassé lors de l’attaque surprise des forces japonaises — étant bien connue, je m’appuie sur cet exemple comme point de départ afin de contextualiser la situation des musiciens militaires après les événements de Pearl Harbor, en décembre 1941. Dans le sillage de ce grand moment de l’Histoire, j’évoque ici des histoires à une autre échelle, celle de la « micro-histoire »— celle d’un militaire seul au milieu d’autres militaires. À travers les lettres échangées entre des recrues ayant suivi ensemble la même formation, je trace ici leurs expériences de guerre en tant qu’artistes, ainsi que les divers conflits pratiques et idéologiques qui se manifestent dans la tension entre l’art musical et l’art martial.

  20. Factors influencing phase-disengagement rates in solvent-extraction systems employing tertiary amine extractants

    International Nuclear Information System (INIS)

    Moyer, B.A.; McDowell, W.J.

    1981-01-01

    The primary purpose of the present investigation was to examine the effects of amine size and structure on phase disengagement. Nine commercial tertiary amines were tested together with four laboratory-quality amines for uranium extraction and both organic-continuous (OC) and aqueous-continuous (AC) phase disengagement under Amex-type conditions. Synthetic acid sulfate solutions with and without added colloidal silica and actual ore leach solutions were used as the aqueous phases. Phase disengagement results were correlated with amine size and branching and solution wetting behavior on a silicate (glass) surface. The results suggest that the performance of some Amex systems may be improved by using branched chain tertiary amine extractants of higher molecular weight than are now normally used

  1. Amine functionalized cubic mesoporous silica nanoparticles as an oral delivery system for curcumin bioavailability enhancement

    Science.gov (United States)

    Budi Hartono, Sandy; Hadisoewignyo, Lannie; Yang, Yanan; Meka, Anand Kumar; Antaresti; Yu, Chengzhong

    2016-12-01

    In the present work, a simple method was used to develop composite curcumin-amine functionalized mesoporous silica nanoparticles (MSN). The nanoparticles were used to improve the bioavailability of curcumin in mice through oral administration. We investigated the effect of particle size on the release profile, solubility and oral bioavailability of curcumin in mice, including amine functionalized mesoporous silica micron-sized-particles (MSM) and MSN (100-200 nm). Curcumin loaded within amine functionalized MSN (MSN-A-Cur) had a better release profile and a higher solubility compared to amine MSM (MSM-A-Cur). The bioavailability of MSN-A-Cur and MSM-A-Cur was considerably higher than that of ‘free curcumin’. These results indicate promising features of amine functionalized MSN as a carrier to deliver low solubility drugs with improved bioavailability via the oral route.

  2. Biogenic Amines as Quality Marker in Organic and Fair-Trade Cocoa-Based Products

    Directory of Open Access Journals (Sweden)

    Donatella Restuccia

    2016-08-01

    Full Text Available In this study, the quantitative determination of eight biogenic amines (cadaverine, serotonin, histamine, spermidine, spermine, tyramine, putrescine and β-phenylethylamine by an liquid chromatography method with evaporative light scattering detection was performed. The analysis of several samples of conventional, organic and fair trade cocoa-derivatives showed that organic and fair trade samples always contain much lower amine concentrations in comparison with their conventional counterparts, supporting the idea that biogenic amines can be regarded as cocoa quality markers. Irrespective of the kind of sample, results also showed that the most abundant amines were histamine, tyramine, spermidine, putrescine and spermine while β-phenylethylamine, cadaverine and serotonine have been found more rarely, all the amines never reaching dangerous amounts for consumer health. With the aim to confirm the experimental results, clustering analysis was performed on samples and instrumental results using principal component analysis.

  3. Amine oxidase from lentil seedlings: energetic domains and effect of temperature on activity.

    Science.gov (United States)

    Moosavi-Nejad, S Z; Rezaei-Tavirani, M; Padiglia, A; Floris, G; Moosavi-Movahedi, A A

    2001-07-01

    Copper/TPQ amine oxidases from mammalian and plant sources have shown many differences in substrate specificity and molecular properties. In this work the activity of lentil seedling amine oxidase was followed at various temperatures in 100 mM potassium phosphate buffer, pH 7, using benzylamine as substrate. The discontinuous Arrhenius plot of lentil amine oxidase showed two distinct phases with a jump between them. Thermal denaturation of the enzyme, using differential scanning calorimetry under the same experimental conditions, showed a transition at the same temperature ranges in the absence of substrate, indicating the occurrence of conformational changes, with an enthalpy change of about 175.9 kJ/mole. The temperature-induced changes of the activity of lentil amine oxidase are compared with those of bovine serum amine oxidase (taken from the literature).

  4. Functional expression of amine oxidase from Aspergillus niger (AO-I) in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kolaríková, Katerina; Galuszka, Petr; Sedlárová, Iva; Sebela, Marek; Frébort, Ivo

    2009-01-01

    The aim of this work was to prepare recombinant amine oxidase from Aspergillus niger after overexpressing in yeast. The yeast expression vector pDR197 that includes a constitutive PMA1 promoter was used for the expression in Saccharomyces cerevisiae. Recombinant amine oxidase was extracted from the growth medium of the yeast, purified to homogeneity and identified by activity assay and MALDI-TOF peptide mass fingerprinting. Similarity search in the newly published A. niger genome identified six genes coding for copper amine oxidase, two of them corresponding to the previously described enzymes AO-I a methylamine oxidase and three other genes coding for FAD amine oxidases. Thus, A. niger possesses an enormous metabolic gear to grow on amine compounds and thus support its saprophytic lifestyle.

  5. A practical and catalyst-free trifluoroethylation reaction of amines using trifluoroacetic acid

    Science.gov (United States)

    Andrews, Keith G.; Faizova, Radmila; Denton, Ross M.

    2017-06-01

    Amines are a fundamentally important class of biologically active compounds and the ability to manipulate their physicochemical properties through the introduction of fluorine is of paramount importance in medicinal chemistry. Current synthesis methods for the construction of fluorinated amines rely on air and moisture sensitive reagents that require special handling or harsh reductants that limit functionality. Here we report practical, catalyst-free, reductive trifluoroethylation reactions of free amines exhibiting remarkable functional group tolerance. The reactions proceed in conventional glassware without rigorous exclusion of either moisture or oxygen, and use trifluoroacetic acid as a stable and inexpensive fluorine source. The new methods provide access to a wide range of medicinally relevant functionalized tertiary β-fluoroalkylamine cores, either through direct trifluoroethylation of secondary amines or via a three-component coupling of primary amines, aldehydes and trifluoroacetic acid. A reduction of in situ-generated silyl ester species is proposed to account for the reductive selectivity observed.

  6. In Situ Preparation of Polyether Amine Functionalized MWCNT Nanofiller as Reinforcing Agents

    Directory of Open Access Journals (Sweden)

    Ayber Yıldrım

    2014-01-01

    Full Text Available In situ preparation of polyether amine functionalized cross-linked multiwalled carbon nanotube (MWCNT nanofillers may improve the thermal and mechanical properties of the composites in which they are used as reinforcing agents. The reduction and functionalization of MWCNT using ethylenediamine in the presence of polyether amine produced stitched MWCNT's due to the presence of two amine (–NH2 functionalities on both sides of the polymer. Polyether amine was chosen to polymerize the carboxylated MWCNT due to its potential to form bonds with the amino groups and carboxyl groups of MWCNT which produces a resin used as polymeric matrix for nanocomposite materials. The attachment of the polyether amine (Jeffamine groups was verified by TGA, FT-IR, XRD, SEM, and Raman spectroscopy. The temperature at which the curing enthalpy is maximum, observed by DSC, was shifted to higher values by adding functionalized MWCNT. SEM images show the polymer formation between MWCNT sheets.

  7. Metal-Mediated Couplings of Primary Alcohols with Amines and Carbohydrates

    DEFF Research Database (Denmark)

    Maggi, Agnese; Madsen, Robert

    . The reaction is proposed to proceed by initial dehydrogenation of the alcohol to the aldehyde, which stays coordinated to the ruthenium centre. Then, nucleophilic attack of the amine affords the hemiaminal, which is released from ruthenium and converted into the imine. Project 2: Tin-mediated regioselective 6...... from alcohols and amines catalyzed by a ruthenium N-heterocyclic carbene complex. The successful method development and application of a convenient and direct (one step) synthesis of imines from alcohols and amines is described. The developed method provides quick andextended access to structurally...... and amines have been coupled in the presence of the catalyst to afford the corresponding imines in moderate to good yields. Optically pure amines gave the corresponding imines without any sign of racemization. Moreover, the one-pot diastereoselective addition of different organometallic reagents to the imine...

  8. Determination of oxyfluorfen herbicide and oxyfluorfen amine residues in garbanzo beans by liquid chromatography.

    Science.gov (United States)

    Zhou, M; Miles, C J

    1991-01-01

    Oxyfluorfen and oxyfluorfen amine were determined by liquid chromatography (LC) with ultraviolet (UV) and photoconductivity detection (PCD). A simple extraction procedure acceptably recovered both analytes from garbanzo beans over a wide range of fortifications (0.05 to 20 ppm) (83 +/- 4 for oxyfluorfen; 85 +/- 4 for oxyfluorfen amine). Percent recoveries decreased slightly as the fortification level decreased. Both analytes could be determined simultaneously at a concentration greater than 0.2 ppm in garbanzo beans. Detection limits were 3 ng for oxyfluorfen and 100 ng for oxyfluorfen amine using LC/UV, and 12 ng for both oxyfluorfen and oxyfluorfen amine with LC/PCD. Different knitted reaction coils and photoreactors were evaluated. Photoproduct yields and identification were determined by ion chromatography. The LC/PCD method measures oxyfluorfen and oxyfluorfen amine separately and has a shorter analysis time, while the standard method using gas chromatography measures total residues and is more sensitive.

  9. Platinum-Catalyzed, Terminal-Selective C(sp(3))-H Oxidation of Aliphatic Amines.

    Science.gov (United States)

    Lee, Melissa; Sanford, Melanie S

    2015-10-14

    This Communication describes the terminal-selective, Pt-catalyzed C(sp(3))-H oxidation of aliphatic amines without the requirement for directing groups. CuCl2 is employed as a stoichiometric oxidant, and the reactions proceed in high yield at Pt loadings as low as 1 mol%. These transformations are conducted in the presence of sulfuric acid, which reacts with the amine substrates in situ to form ammonium salts. We propose that protonation of the amine serves at least three important roles: (i) it renders the substrates soluble in the aqueous reaction medium; (ii) it limits binding of the amine nitrogen to Pt or Cu; and (iii) it electronically deactivates the C-H bonds proximal to the nitrogen center. We demonstrate that this strategy is effective for the terminal-selective C(sp(3))-H oxidation of a variety of primary, secondary, and tertiary amines.

  10. Bioinspired aerobic oxidation of secondary amines and nitrogen heterocycles with a bifunctional quinone catalyst.

    Science.gov (United States)

    Wendlandt, Alison E; Stahl, Shannon S

    2014-01-08

    Copper amine oxidases are a family of enzymes with quinone cofactors that oxidize primary amines to aldehydes. The native mechanism proceeds via an iminoquinone intermediate that promotes high selectivity for reactions with primary amines, thereby constraining the scope of potential biomimetic synthetic applications. Here we report a novel bioinspired quinone catalyst system consisting of 1,10-phenanthroline-5,6-dione/ZnI2 that bypasses these constraints via an abiological pathway involving a hemiaminal intermediate. Efficient aerobic dehydrogenation of non-native secondary amine substrates, including pharmaceutically relevant nitrogen heterocycles, is demonstrated. The ZnI2 cocatalyst activates the quinone toward amine oxidation and provides a source of iodide, which plays an important redox-mediator role to promote aerobic catalytic turnover. These findings provide a valuable foundation for broader development of aerobic oxidation reactions employing quinone-based catalysts.

  11. Environmentally friendly chemoselective oxidation of primary aliphatic amines by using a biomimetic electrocatalytic system.

    Science.gov (United States)

    Largeron, Martine; Chiaroni, Angèle; Fleury, Maurice-Bernard

    2008-01-01

    Environmentally friendly oxidation of primary aliphatic amines to imines has been successfully achieved, under metal-free conditions, by the use of diverse electrogenerated o-azaquinone mediators. High catalytic performance, together with high chemoselectivity, were observed with electron-poor o-azaquinone catalysts generated from 2-aminoresorcinol derivatives. Similar to copper amine oxidase enzymes, these mediators exhibited lower reactivity toward alpha-branched primary amines and no reactivity toward secondary amines. In the case of 3,4-aminophenol derivatives lacking a 2-hydroxy group, the generated o-azaquinone species failed to catalyze the oxidation of the amine to the corresponding imine. Further mechanistic considerations allowed a rationalization of the crucial role of the 2-hydroxy group in converting a catalytically inert species into a highly effective biomimetic catalyst.

  12. Extraction and purification of plutonium by a tertiary amine; Extraction et purification du plutonium par une amine tertiaire

    Energy Technology Data Exchange (ETDEWEB)

    Trentinian, M de; Chesne, A [Commissariat a l' Energie Atomique, Fontenay aux Roses, Section de Chimie des Actimides (France).Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Trilaurylamine diluted with a paraffinic solvent (dodecane) was studied as part of the research dealing with the separation and purification of plutonium. The physical properties (solubility of nitrates in the amine as a function of temperature) and the resistance to radiations of this substance were examined. The extraction characteristics of nitric solutions of plutonium, uranium and certain fission products are given as a function of the following factors: concentration of the various ions in solution, valency states. A method of plutonium purification based on these results is presented. (author) [French] La trilaurylamine diluee par un solvant paraffinique (dodecane) a ete etudiee dans le cadre des recherches concernant la separation et la purification du plutonium. Une etude des caracteres physiques (solubilite des nitrates dans l'amine en fonction de la temperature) s'ajoute a celle de la tenue aux radiations de ce corps. Les caracteristiques d'extraction de solutions nitriques de plutonium, uranium, et certains produits de fission, sont donnes en fonction des facteurs suivants: concentration des differents ions en solution, etats de valence. On presente une methode de purification du plutonium basee sur ces resultats. (auteur)

  13. Electron beam melting of bearing materials

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmied, G.; Schuler, A. (Technische Univ., Vienna (Austria). Inst. fuer Allgemeine Elektrotechnik); Elsinger, G.; Koroschetz, F. (MIBA Gleitlager AG, Laakirchen (Austria)); Tschegg, E.K. (Technische Univ., Vienna (Austria). Inst. fuer Angewandte und Technische Physik)

    1990-06-01

    This paper reports on a surface treatment method for the bearing materials AlSn6 which permits the use of this material without the overlay usually required. Microstructural refinement is achieved by means of a surface melting technique using an electron beam with successive rapid solidification. Extremely fine tin precipitates are formed in the melted surface layer which lead to significantly better tribological properties of the bearing material. Tests compared the tribological properties for AlSn6 bearings treated by the surface melting technique with those of untreated bearings. Whereas all untreated bearings failed by seizure after only 2 h of testing, 30% of the tested bearings which had been surface melted survived the entire testing program without damage.

  14. Bearing Health Assessment Based on Chaotic Characteristics

    Directory of Open Access Journals (Sweden)

    Chen Lu

    2013-01-01

    Full Text Available Vibration signals extracted from rotating parts of machinery carry a lot of useful information about the condition of operating machine. Due to the strong non-linear, complex and non-stationary characteristics of vibration signals from working bearings, an accurate and reliable health assessment method for bearing is necessary. This paper proposes to utilize the selected chaotic characteristics of vibration signal for health assessment of a bearing by using self-organizing map (SOM. Both Grassberger-Procaccia algorithm and Takens' theory are employed to calculate the characteristic vector which includes three chaotic characteristics, such as correlation dimension, largest Lyapunov exponent and Kolmogorov entropy. After that, SOM is used to map the three corresponding characteristics into a confidence value (CV which represents the health state of the bearing. Finally, a case study based on vibration datasets of a group of testing bearings was conducted to demonstrate that the proposed method can reliably assess the health state of bearing.

  15. Effect of foamability index of short chain alkyl amines on flotation of quartz

    Directory of Open Access Journals (Sweden)

    Szczerkowska Sabina

    2016-01-01

    Full Text Available Amines can be used for flotation of various minerals, especially quartz. The flotation efficiency of quartz depends on the amine type and dose. It was proved that the shorter alkyl amine, higher amine concentration has to be used to recover quartz at the same level. In flotation amines play a role of both collectors and frothers. The ability of a amine to collect particles can be expressed in the form of contact angle, while the foaming properties by different parameters including dynamic foamability index (DFI and critical coalescence concentration (CCC. Determination of DFI and CCC requires advanced techniques and methods. Therefore, in this paper a rapid and facile method for determination of foaming properties of amines and also other surfactants was used. It was based on measuring the initial foam and froth heights in a conventional flotation machine at different concentrations of surfactants. The foam height-concentration curve was described by utilizing an empirical equation which was based on one-adjustable parameter called the foamability index (FI. In this work the foamability index was determined for butylamine (ButNH2, hexylamine (HexNH2 and octylamine (OctNH2 as examples of short chain alkyl amines. The determined foamability indices were 92, 12 and 4 mg/dm3 for ButNH2, HexNH2 and OctNH2, respectively. It was shown that when the flotation results of quartz were presented in the form of recovery versus normalized amine concentration in relation to the foamability index (c/FI, all the experimental data points converged to one curve. It indicates that amines act similarly but at different concentrations expressed as FI. The foamability index seems to be a useful parameter for characterizing any flotation frother.

  16. Multi-Objective Optimization for Solid Amine CO2 Removal Assembly in Manned Spacecraft

    Directory of Open Access Journals (Sweden)

    Rong A

    2017-07-01

    Full Text Available Carbon Dioxide Removal Assembly (CDRA is one of the most important systems in the Environmental Control and Life Support System (ECLSS for a manned spacecraft. With the development of adsorbent and CDRA technology, solid amine is increasingly paid attention due to its obvious advantages. However, a manned spacecraft is launched far from the Earth, and its resources and energy are restricted seriously. These limitations increase the design difficulty of solid amine CDRA. The purpose of this paper is to seek optimal design parameters for the solid amine CDRA. Based on a preliminary structure of solid amine CDRA, its heat and mass transfer models are built to reflect some features of the special solid amine adsorbent, Polyethylenepolyamine adsorbent. A multi-objective optimization for the design of solid amine CDRA is discussed further in this paper. In this study, the cabin CO2 concentration, system power consumption and entropy production are chosen as the optimization objectives. The optimization variables consist of adsorption cycle time, solid amine loading mass, adsorption bed length, power consumption and system entropy production. The Improved Non-dominated Sorting Genetic Algorithm (NSGA-II is used to solve this multi-objective optimization and to obtain optimal solution set. A design example of solid amine CDRA in a manned space station is used to show the optimal procedure. The optimal combinations of design parameters can be located on the Pareto Optimal Front (POF. Finally, Design 971 is selected as the best combination of design parameters. The optimal results indicate that the multi-objective optimization plays a significant role in the design of solid amine CDRA. The final optimal design parameters for the solid amine CDRA can guarantee the cabin CO2 concentration within the specified range, and also satisfy the requirements of lightweight and minimum energy consumption.

  17. Characterization of molybdenum interfacial crud in a uranium mill that employs tertiary-amine solvent extraction

    International Nuclear Information System (INIS)

    Moyer, B.; McDowell, W.J.

    1983-01-01

    In the present work, samples of a molybdenum-caused green gummy interfacial crud from an operating western US uranium mill have been physically and chemically examined. Formaton of cruds of this description has been a long-standing problem in the use of tertiary amine solvent extraction for the recovery of uranium from low-grade ores (Amex Process). The crud is essentially an organic-continuous dispersion containing about 10 wt % aqueous droplets and about 37 wt % greenish-yellow crystalline solids suspended in kerosene-amine process solvent. The greenish-yellow crystals were found to be a previously unknown double salt of tertiary amine molybdophosphate with three tertiary amine chlorides having the empirical formula (R 3 NH) 3 [PMo 12 O 40 ].3(R 3 NH)Cl. To confirm the identification of the compound, a pure trioctylamine (TOA) analog was synthesized. In laboratory extraction experiments, it was demonstrated that organic-soluble amine molydophosphate forms slowly upon contact of TOA solvent with dilute sulfuric acid solutions containing low concentrations of molybdate and phosphate. If the organic solutions of amine molybdophosphate were then contacted with aqueous NaCl solutions, a greenish-yellow precipitate of (TOAH) 3 [PMo 12 O 40 ].3(TOAH)Cl formed at the interface. The proposed mechanism for the formation of the crud under process conditions involves build up of molybdenum in the solvent, followed by reaction with extracted phosphate to give dissolved amine molybdophosphate. The amine molybdophosphate then co-crystallizes with amine chloride, formed during the stripping cycle, to give the insoluble double salt, which precipitates as a layer of small particles at the interface. The proposed solution to the problem is the use of branched-chain, instead of straight-chain, tertiary amine extractants under the expectation that branching would increase the solubility of the double salt. 2 figures, 5 tables

  18. Trends in Controllable Oil Film Bearings

    DEFF Research Database (Denmark)

    Santos, Ilmar

    2011-01-01

    This work gives an overview about the theoretical and experimental achievements of mechatronics applied to oil film bearings, with the aim of: controlling the lateral vibration of flexible rotating shafts; modifying bearing dynamic characteristics, as stiffness and damping properties; increasing......" components and be applied to rotating machines with the goal of avoiding unexpected stops of plants, performing rotordynamic tests and identifying model parameters "on site". Emphasis is given to the controllable lubrication (active lubrication) applied to different types of oil film bearings, i...

  19. Binding Constant of Amines to Water/AOT/n-Hexene Reverse Micelles. Influence of the Chemical Structure

    Directory of Open Access Journals (Sweden)

    J. J. Silber

    2000-03-01

    Full Text Available The distribution of different amines between n-hexane bulk and the micellar pseudophase of AOT reverse micelles were measured by a fluorometric method. An independent method was used to corroborate the incorporation of the amines to the interface. The effect of the amine structure on the binding constant was analysed.

  20. Structure-activity relationships of lipopolysaccharide sequestration in guanylhydrazone-bearing lipopolyamines.

    Science.gov (United States)

    Wu, Wenyan; Sil, Diptesh; Szostak, Michal L; Malladi, Subbalakshmi S; Warshakoon, Hemamali J; Kimbrell, Matthew R; Cromer, Jens R; David, Sunil A

    2009-01-15

    The toxicity of gram-negative bacterial endotoxin (lipopolysaccharide, LPS) resides in its structurally highly conserved glycolipid component called lipid A. Our major goal has been to develop small-molecules that would sequester LPS by binding to the lipid A moiety, so that it could be useful for the prophylaxis or adjunctive therapy of gram-negative sepsis. We had previously identified in rapid-throughput screens several guanylhydrazones as potent LPS binders. We were desirous of examining if the presence of the guanylhydrazone (rather than an amine) functionality would afford greater LPS sequestration potency. In evaluating a congeneric set of guanylhydrazone analogues, we find that C(16) alkyl substitution is optimal in the N-alkylguanylhydrazone series; a homospermine analogue with the terminal amine N-alkylated with a C(16) chain with the other terminus of the molecule bearing an unsubstituted guanylhydrazone moiety is marginally more active, suggesting very slight, if any, steric effects. Neither C(16) analogue is significantly more active than the N-C(16)-alkyl or N-C(16)-acyl compounds that we had characterized earlier, indicating that basicity of the phosphate-recognizing cationic group, is not a determinant of LPS sequestration activity.

  1. Technical Development Path for Gas Foil Bearings

    Science.gov (United States)

    Dellacorte, Christopher

    2016-01-01

    Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

  2. Gearbox Reliability Collaborative Bearing Calibration

    Energy Technology Data Exchange (ETDEWEB)

    van Dam, J.

    2011-10-01

    NREL has initiated the Gearbox Reliability Collaborative (GRC) to investigate the root cause of the low wind turbine gearbox reliability. The GRC follows a multi-pronged approach based on a collaborative of manufacturers, owners, researchers and consultants. The project combines analysis, field testing, dynamometer testing, condition monitoring, and the development and population of a gearbox failure database. At the core of the project are two 750kW gearboxes that have been redesigned and rebuilt so that they are representative of the multi-megawatt gearbox topology currently used in the industry. These gearboxes are heavily instrumented and are tested in the field and on the dynamometer. This report discusses the bearing calibrations of the gearboxes.

  3. Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage.

    Science.gov (United States)

    Hailer, Frank; Kutschera, Verena E; Hallström, Björn M; Klassert, Denise; Fain, Steven R; Leonard, Jennifer A; Arnason, Ulfur; Janke, Axel

    2012-04-20

    Recent studies have shown that the polar bear matriline (mitochondrial DNA) evolved from a brown bear lineage since the late Pleistocene, potentially indicating rapid speciation and adaption to arctic conditions. Here, we present a high-resolution data set from multiple independent loci across the nuclear genomes of a broad sample of polar, brown, and black bears. Bayesian coalescent analyses place polar bears outside the brown bear clade and date the divergence much earlier, in the middle Pleistocene, about 600 (338 to 934) thousand years ago. This provides more time for polar bear evolution and confirms previous suggestions that polar bears carry introgressed brown bear mitochondrial DNA due to past hybridization. Our results highlight that multilocus genomic analyses are crucial for an accurate understanding of evolutionary history.

  4. New insights into controlling tube-bundle fouling using alternative amines

    Energy Technology Data Exchange (ETDEWEB)

    Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Fruzzetti, K. [Atomic Energy of Canada Ltd. (Canada); Frattini, P.L. [Electric Power Research Inst. (United States)

    2002-07-01

    A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of deposit consolidation result in a low rate of deposit removal and a high fouling rate. Conversely, amines that tend to inhibit deposit consolidation produce a higher rate of deposit removal and a lower fouling rate. Dimethyl-amine and dodecyl-amine have been identified as two amines that inhibit the rate of deposit consolidation and, consequently, result in fouling rates that are up to 5 times lower than rates measured for amines that promote consolidation. A significant difference between morpholine (high fouling rate) and dimethyl-amine (low fouling rate) is that the latter desorbs more slowly from the surface of magnetite. How to account for a correlation between slow desorption kinetics and lower rate constants for deposition and

  5. New insights into controlling tube-bundle fouling using alternative amines

    International Nuclear Information System (INIS)

    Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Frattini, P.L.; Fruzzetti, K.

    2002-01-01

    A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. Atomic Energy of Canada Limited (AECL) and Electric Power Research Institute (EPRI) have been collaborating in an extensive investigation of the effectiveness of amines at controlling the rate of tube-bundle fouling under SG operating conditions. Tests have been performed using a radiotracing technique in a high-temperature fouling loop facility at Chalk River Laboratories operated by AECL. This investigation has provided new insights into the role played by the amine in determining the rate of tube-bundle fouling in the SG. These insights are being used by AECL and EPRI to develop criteria for the selection of an amine that has optimum properties for both corrosion control and deposit control in the secondary heat transport system. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of

  6. New insights into controlling tube-bundle fouling using alternative amines

    International Nuclear Information System (INIS)

    Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Fruzzetti, K.; Frattini, P.L.

    2002-01-01

    A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of deposit consolidation result in a low rate of deposit removal and a high fouling rate. Conversely, amines that tend to inhibit deposit consolidation produce a higher rate of deposit removal and a lower fouling rate. Dimethyl-amine and dodecyl-amine have been identified as two amines that inhibit the rate of deposit consolidation and, consequently, result in fouling rates that are up to 5 times lower than rates measured for amines that promote consolidation. A significant difference between morpholine (high fouling rate) and dimethyl-amine (low fouling rate) is that the latter desorbs more slowly from the surface of magnetite. How to account for a correlation between slow desorption kinetics and lower rate constants for deposition and

  7. Treatment of alpha bearing wastes

    International Nuclear Information System (INIS)

    1988-01-01

    This report deals with the current state of the art of alpha waste treatment, which is an integral part of the overall nuclear waste management system. The International Atomic Energy Agency (IAEA) defines alpha bearing waste as 'waste containing one or more alpha emitting radionuclides, usually actinides, in quantities above acceptable limits'. The limits are established by national regulatory bodies. The limits above which wastes are considered as alpha contaminated refer to the concentrations of alpha emitters that need special consideration for occupational exposures and/or potential safety, health, or environmental impact during one or more steps from generation through disposal. Owing to the widespread use of waste segregation by source - that is, based upon the 'suspect origin' of the material - significant volumes of waste are being handled as alpha contaminated which, in fact, do not require such consideration by reason of risk or environmental concern. The quantification of de minimis concepts by national regulatory bodies could largely contribute to the safe reduction of waste volumes and associated costs. Other factors which could significantly contribute to the reduction of alpha waste arisings are an increased application of assaying and sorting, instrumentation and the use of feedback mechanisms to control or modify the processes which generate these wastes. Alpha bearing wastes are generated during fabrication and reprocessing of nuclear fuels, decommissioning of alpha contaminated facilities, and other activities. Most alpha wastes are contact handled, but a small portion may require shielding or remote handling because of high levels of neutron (n), beta (β), or gamma (γ) emissions associated with the waste material. This report describes the sources and characteristics of alpha wastes and strategies for alpha waste management. General descriptions of treatment processes for solid and liquid alpha wastes are included. 71 refs, 14 figs, 9 tabs

  8. Highly Aminated Mesoporous Silica Nanoparticles with Cubic Pore Structure

    KAUST Repository

    Suteewong, Teeraporn

    2011-01-19

    Mesoporous silica with cubic symmetry has attracted interest from researchers for some time. Here, we present the room temperature synthesis of mesoporous silica nanoparticles possessing cubic Pm3n symmetry with very high molar ratios (>50%) of 3-aminopropyl triethoxysilane. The synthesis is robust allowing, for example, co-condensation of organic dyes without loss of structure. By means of pore expander molecules, the pore size can be enlarged from 2.7 to 5 nm, while particle size decreases. Adding pore expander and co-condensing fluorescent dyes in the same synthesis reduces average particle size further down to 100 nm. After PEGylation, such fluorescent aminated mesoporous silica nanoparticles are spontaneously taken up by cells as demonstrated by fluorescence microscopy.

  9. Preparation and reactivity studies of maleimidophenyl glycidylether with amines

    Directory of Open Access Journals (Sweden)

    B. Lakshmi

    2011-04-01

    Full Text Available The hybrid thermosetting maleimido epoxy compound 4-(N-maleimidophenyl glycidylether (N-MPGE was prepared by reacting N-(4-hydroxyphenyl maleimide (HPM with epichlorohydrin by using benzyltrimethylammonium chloride as a catalyst. The resulting compound possessed both the oxirane ring and maleimide group. The curing reaction of N-MPGE with amines as curing agents such as tetraethylenepentamine (TEPA, bishexamethylenetriamine (BHMT, 2-methyl pentamethylenediamine (2-MPMDA and 2,2,4-trimethy diamines (2,2,4-TMDA was studied. The cured samples exhibited good thermal stability and excellent chemical (acid/alkali/solvent and water absorption resistance. Morphological studies by the SEM technique further confirmed the phase homogeneity network of the cured systems.

  10. Thermodynamics of organic mixtures containing amines. VIII. Systems with quinoline

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio [G.E.T.E.F., Grupo Especializado en Termodinamica de Equilibrio entre Fases, Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, E-47071 Valladolid (Spain)], E-mail: jagl@termo.uva.es; Domanska, Urszula; Zawadzki, Maciej [Physical Chemistry Division, Faculty of Chemistry, Warsaw University of Technology, 00-664 Warsaw (Poland)

    2008-08-15

    (Solid + liquid) equilibrium temperatures for mixtures containing quinoline and 1-dodecanol, 1-hexadecanol, or 1-octadecanol have been measured using a dynamic method. (Quinoline + benzene, +alkane, or +1-alkanol) systems were investigated using DISQUAC. The corresponding interaction parameters are reported. The model yields a good representation of molar excess Gibbs free energies, G{sup E}, molar excess enthalpies, H{sup E}, and of the (solid + liquid) equilibria, SLE. Interactional and structural effects were analysed comparing H{sup E} and the molar excess internal energy at constant volume, U{sub V}{sup E}. It was encountered that structural effects are very important in systems involving alkanes or 1-alkanols. Interactions between amine molecules are stronger in mixtures with quinoline than in those containing pyridine, which was ascribed to the higher polarizability of quinoline.

  11. Recyclable surfaces for amine conjugation chemistry via redox reaction

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Inseong; Yeo, Woon Seok [Dept. of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul (Korea, Republic of); Bae, Se Won [Green Materials and Process Group, Research Institute of Sustainable Manufacturing System, Korea Institute of Industrial Technology, Cheonan (Korea, Republic of)

    2017-02-15

    In this study, we extended this strategy to present a switchable surface that allows surface functionalization and removal of functional groups repeatedly. The substrate presenting a benzoquinone acid group is first used to immobilize with an amine-containing (bio)molecule using well-known conjugation chemistry. The benzoquinone group is then converted to the corresponding hydroquinone by treating with a reducing agent. We have described a strategy for the dynamic control of surface properties with recyclability via a simple reduction/ oxidation reaction. A stimuli-responsive quinone derivative was harnessed for the repeated immobilization and release of (bio)molecules, and thus, for the repeated dynamic change of the surface properties according to the characteristics of the immobilized (bio)molecules.

  12. Highly Aminated Mesoporous Silica Nanoparticles with Cubic Pore Structure

    KAUST Repository

    Suteewong, Teeraporn; Sai, Hiroaki; Cohen, Roy; Wang, Suntao; Bradbury, Michelle; Baird, Barbara; Gruner, Sol M.; Wiesner, Ulrich

    2011-01-01

    Mesoporous silica with cubic symmetry has attracted interest from researchers for some time. Here, we present the room temperature synthesis of mesoporous silica nanoparticles possessing cubic Pm3n symmetry with very high molar ratios (>50%) of 3-aminopropyl triethoxysilane. The synthesis is robust allowing, for example, co-condensation of organic dyes without loss of structure. By means of pore expander molecules, the pore size can be enlarged from 2.7 to 5 nm, while particle size decreases. Adding pore expander and co-condensing fluorescent dyes in the same synthesis reduces average particle size further down to 100 nm. After PEGylation, such fluorescent aminated mesoporous silica nanoparticles are spontaneously taken up by cells as demonstrated by fluorescence microscopy.

  13. Purification and characterization of amine oxidase from soybean seedlings.

    Science.gov (United States)

    Vianello, F; Di Paolo, M L; Stevanato, R; Gasparini, R; Rigo, A

    1993-11-15

    A simple and rapid procedure for purification of soybean seedling amine oxidase is reported. The crude enzyme, obtained by ammonium sulfate fractionation was purified by ion-exchange chromatography on a cellulose phosphate column and batch affinity chromatography on 6-aminohexyl-Sepharose. Cyclohexylamine, a competitive inhibitor, was utilized to elute the enzyme. A homogeneous enzyme was obtained with a yield higher than 25%, the content of minor components being lauryl sulfate-polyacrylamide gel electrophoresis. The enzyme is a dimer and contains two Cu2+ ion per molecule. Its EPR spectrum is typical of Cu2+ in a tetragonal symmetry. The enzyme oxidizes cadaverine at high rate, the specific activity being 4.3 mukat/mg. Molecular, spectroscopic, and kinetic properties of this enzyme are reported.

  14. Synthesis of allyl amine on glass by continuous plasma

    International Nuclear Information System (INIS)

    Morales, J.; Olayo, R.; Vasquez, M.; OLayo, M.G.; Cruz, G.

    2003-01-01

    In this work the synthesis by plasma of thin films of polyallyl amine under continuous plasma conditions for possible use in biomaterials is presented. It is shown that the thickness of the film depends so much of the time of synthesis like of the used power. The polymers were analyzed by X-ray photoelectron spectroscopy (XPS) and angle of contact before and after of being immersed in distilled water by 10 days. The allylamine shows lost of nitrogen and an increase in the content of oxygen with the immersion time due to the interaction among the water and the polymer. The angle of contact shows an increase of approximately 10 degrees, what indicates a change in the surface energy of the polymer. (Author)

  15. Evaluation of bearing configurations using the single bearing tester in liquid nitrogen

    Science.gov (United States)

    Jett, T.; Hall, P.; Thom, R.

    1991-01-01

    Various bearing configurations were tested using the Marshall Space Flight Center single bearing tester with LN2 as the cryogenic coolant. The baseline was one Rocketdyne phase one high pressure oxidizer turbopump (HPOTP) pump end 45-mm bore bearing. The bearing configurations that were tested included a Salox/M cage configuration, a silicon nitride ball configuration, an elongated cage configuration, and a Bray 601 grease configuration.

  16. Rolling Bearing Life Prediction, Theory, and Application

    Science.gov (United States)

    Zaretsky, Erwin V.

    2016-01-01

    A tutorial is presented outlining the evolution, theory, and application of rolling-element bearing life prediction from that of A. Palmgren, 1924; W. Weibull, 1939; G. Lundberg and A. Palmgren, 1947 and 1952; E. Ioannides and T. Harris, 1985; and E. Zaretsky, 1987. Comparisons are made between these life models. The Ioannides-Harris model without a fatigue limit is identical to the Lundberg-Palmgren model. The Weibull model is similar to that of Zaretsky if the exponents are chosen to be identical. Both the load-life and Hertz stress-life relations of Weibull, Lundberg and Palmgren, and Ioannides and Harris reflect a strong dependence on the Weibull slope. The Zaretsky model decouples the dependence of the critical shear stress-life relation from the Weibull slope. This results in a nominal variation of the Hertz stress-life exponent. For 9th- and 8th-power Hertz stress-life exponents for ball and roller bearings, respectively, the Lundberg-Palmgren model best predicts life. However, for 12th- and 10th-power relations reflected by modern bearing steels, the Zaretsky model based on the Weibull equation is superior. Under the range of stresses examined, the use of a fatigue limit would suggest that (for most operating conditions under which a rolling-element bearing will operate) the bearing will not fail from classical rolling-element fatigue. Realistically, this is not the case. The use of a fatigue limit will significantly overpredict life over a range of normal operating Hertz stresses. (The use of ISO 281:2007 with a fatigue limit in these calculations would result in a bearing life approaching infinity.) Since the predicted lives of rolling-element bearings are high, the problem can become one of undersizing a bearing for a particular application. Rules had been developed to distinguish and compare predicted lives with those actually obtained. Based upon field and test results of 51 ball and roller bearing sets, 98 percent of these bearing sets had acceptable

  17. Trace amine-associated receptor 1-Family archetype or iconoclast?

    Science.gov (United States)

    Grandy, David K

    2007-12-01

    Interest has recently been rekindled in receptors that are activated by low molecular weight, noncatecholic, biogenic amines that are typically found as trace constituents of various vertebrate and invertebrate tissues and fluids. The timing of this resurgent focus on receptors activated by the "trace amines" (TA) beta-phenylethylamine (PEA), tyramine (TYR), octopamine (OCT), synephrine (SYN), and tryptamine (TRYP) is the direct result of 2 publications that appeared in 2001 describing the cloning of a novel G protein-coupled receptor (GPCR) referred to by their discoverers Borowsky et al. as TA1 and Bunzow et al. as TA receptor 1 (TAR1). When heterologously expressed in Xenopus laevis oocytes and various eukaryotic cell lines, recombinant rodent and human TAR dose-dependently couple to the stimulation of adenosine 3',5'-monophosphate (cAMP) production. Structure-activity profiling based on this functional response has revealed that in addition to the TA, other biologically active compounds containing a 2-carbon aliphatic side chain linking an amino group to at least 1 benzene ring are potent and efficacious TA receptor agonists with amphetamine (AMPH), methamphetamine, 3-iodothyronamine, thyronamine, and dopamine (DA) among the most notable. Almost 100 years after the search for TAR began, numerous TA1/TAR1-related sequences, now called TA-associated receptors (TAAR), have been identified in the genome of every species of vertebrate examined to date. Consequently, even though heterologously expressed TAAR1 fits the pharmacological criteria established for a bona fide TAR, a major challenge for those working in the field is to discern the in vivo pharmacology and physiology of each purported member of this extended family of GPCR. Only then will it be possible to establish whether TAAR1 is the family archetype or an iconoclast.

  18. Unbalance Response Prediction for Rotors on Ball Bearings Using Speed and Load Dependent Nonlinear Bearing Stiffness

    Science.gov (United States)

    Fleming, David P.; Poplawski, J. V.

    2003-01-01

    Rolling-element bearing forces vary nonlinearly with bearing deflection. Thus an accurate rotordynamic analysis requires that bearing forces corresponding to the actual bearing deflection be utilized. For this work bearing forces were calculated by COBRA-AHS, a recently developed rolling-element bearing analysis code. Bearing stiffness was found to be a strong function of bearing deflection, with higher deflection producing markedly higher stiffness. Curves fitted to the bearing data for a range of speeds and loads were supplied to a flexible rotor unbalance response analysis. The rotordynamic analysis showed that vibration response varied nonlinearly with the amount of rotor imbalance. Moreover, the increase in stiffness as critical speeds were approached caused a large increase in rotor and bearing vibration amplitude over part of the speed range compared to the case of constant bearing stiffness. Regions of bistable operation were possible, in which the amplitude at a given speed was much larger during rotor acceleration than during deceleration. A moderate amount of damping will eliminate the bistable region, but this damping is not inherent in ball bearings.

  19. Phylogeography of mitochondrial DNA variation in brown bears and polar bears

    Science.gov (United States)

    Shields, Gerald F.; Adams, Deborah; Garner, Gerald W.; Labelle, Martine; Pietsch, Jacy; Ramsay, Malcolm; Schwartz, Charles; Titus, Kimberly; Williamson, Scott

    2000-01-01

    We analyzed 286 nucleotides of the middle portion of the mitochondrial cytochrome b gene of 61 brown bears from three locations in Alaska and 55 polar bears from Arctic Canada and Arctic Siberia to test our earlier observations of paraphyly between polar bears and brown bears as well as to test the extreme uniqueness of mitochondrial DNA types of brown bears on Admiralty, Baranof, and Chichagof (ABC) islands of southeastern Alaska. We also investigated the phylogeography of brown bears of Alaska's Kenai Peninsula in relation to other Alaskan brown bears because the former are being threatened by increased human development. We predicted that: (1) mtDNA paraphyly between brown bears and polar bears would be upheld, (2) the mtDNA uniqueness of brown bears of the ABC islands would be upheld, and (3) brown bears of the Kenai Peninsula would belong to either clade II or clade III of brown bears of our earlier studies of mtDNA. All of our predictions were upheld through the analysis of these additional samples.

  20. Phylogeography of mitochondrial DNA variation in brown bears and polar bears.

    Science.gov (United States)

    Shields, G F; Adams, D; Garner, G; Labelle, M; Pietsch, J; Ramsay, M; Schwartz, C; Titus, K; Williamson, S

    2000-05-01

    We analyzed 286 nucleotides of the middle portion of the mitochondrial cytochrome b gene of 61 brown bears from three locations in Alaska and 55 polar bears from Arctic Canada and Arctic Siberia to test our earlier observations of paraphyly between polar bears and brown bears as well as to test the extreme uniqueness of mitochondrial DNA types of brown bears on Admiralty, Baranof, and Chichagof (ABC) islands of southeastern Alaska. We also investigated the phylogeography of brown bears of Alaska's Kenai Peninsula in relation to other Alaskan brown bears because the former are being threatened by increased human development. We predicted that: (1) mtDNA paraphyly between brown bears and polar bears would be upheld, (2) the mtDNA uniqueness of brown bears of the ABC islands would be upheld, and (3) brown bears of the Kenai Peninsula would belong to either clade II or clade III of brown bears of our earlier studies of mtDNA. All of our predictions were upheld through the analysis of these additional samples. Copyright 2000 Academic Press.