The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform
Massao Ionashiro - One of the best experts on this subject based on the ideXlab platform.
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thermal behavior of malonic acid Sodium Malonate and its compounds with some bivalent transition metal ions in dynamic n2 and co2 atmospheres
Brazilian Journal of Thermal Analysis, 2014Co-Authors: Flavio Junior Caires, L S Lima, D J C Gomes, A C Gigante, Claudio Teodoro De Carvalho, Massao IonashiroAbstract:Thermal stability and thermal decomposition of malonic acid, Sodium Malonate and its compounds with Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) were investigated employing simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC) in N 2 and CO 2 atmospheres and TG-FTIR in N 2 atmosphere. The thermal decomposition of malonic acid occurs with decarboxylation followed by the formation of acetic acid in both atmospheres. For Sodium Malonate the thermal decomposition occurs with formation of Sodium carbonate, and for the transition metal Malonates the final residue was: MnO (N 2 , CO 2 ),FeO (N 2 ), Fe 3 O 4 (CO 2 ), Co + CoO (N 2 ), CoO (CO 2 ), Ni (N 2 , CO 2 ), Cu (N 2 , CO 2 ) and ZnO (N 2 , CO 2 ).
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thermal behaviour of malonic acid Sodium Malonate and its compounds with some bivalent transition metal ions
Thermochimica Acta, 2010Co-Authors: Flavio Junior Caires, L S Lima, Claudio Antonio Talge Carvalho, R J Giagio, Massao IonashiroAbstract:Abstract Solid-state M(L)2·nH2O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its Sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the Sodium nicotinate, the final residue up to 765 °C is Sodium carbonate and for the transition metal nicotinates, the final residues are Mn3O4, Fe2O3, Co3O4, NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds.
Flavio Junior Caires - One of the best experts on this subject based on the ideXlab platform.
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thermal behavior of malonic acid Sodium Malonate and its compounds with some bivalent transition metal ions in dynamic n2 and co2 atmospheres
Brazilian Journal of Thermal Analysis, 2014Co-Authors: Flavio Junior Caires, L S Lima, D J C Gomes, A C Gigante, Claudio Teodoro De Carvalho, Massao IonashiroAbstract:Thermal stability and thermal decomposition of malonic acid, Sodium Malonate and its compounds with Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) were investigated employing simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC) in N 2 and CO 2 atmospheres and TG-FTIR in N 2 atmosphere. The thermal decomposition of malonic acid occurs with decarboxylation followed by the formation of acetic acid in both atmospheres. For Sodium Malonate the thermal decomposition occurs with formation of Sodium carbonate, and for the transition metal Malonates the final residue was: MnO (N 2 , CO 2 ),FeO (N 2 ), Fe 3 O 4 (CO 2 ), Co + CoO (N 2 ), CoO (CO 2 ), Ni (N 2 , CO 2 ), Cu (N 2 , CO 2 ) and ZnO (N 2 , CO 2 ).
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thermal behaviour of malonic acid Sodium Malonate and its compounds with some bivalent transition metal ions
Thermochimica Acta, 2010Co-Authors: Flavio Junior Caires, L S Lima, Claudio Antonio Talge Carvalho, R J Giagio, Massao IonashiroAbstract:Abstract Solid-state M(L)2·nH2O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its Sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the Sodium nicotinate, the final residue up to 765 °C is Sodium carbonate and for the transition metal nicotinates, the final residues are Mn3O4, Fe2O3, Co3O4, NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds.
Biswajit Sinha - One of the best experts on this subject based on the ideXlab platform.
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volumetric and viscometric studies of nicotinic acid in aqueous solutions of Sodium Malonate at t 298 15 318 15 k
The Journal of Chemical Thermodynamics, 2016Co-Authors: Bijan Kumar Pandit, Abhijit Sarkar, Biswajit SinhaAbstract:Abstract Densities and viscosities for the solutions of nicotinic acid in aqueous Sodium Malonate solutions with several molalities ( m Sodium Malonate = 0.000, 0.005, 0.010, 0.015 and 0.020 mol · kg - 1 ) of Sodium Malonate were determined at T = (298.15–318.15) K and at pressure p = 101 kPa. Apparent molar volume ( ϕ V standard partial molar volume ( ϕ V 0 the slope ( S V ∗ ), standard isobaric partial molar expansibility ( ϕ E 0 ) and its temperature dependence ( ∂ ϕ E 0 / ∂ T ) P , the viscosity B-coefficient and solvation number ( S n ), etc., were determined. Using the experimental data viscosity B-coefficients were further utilized to obtain the free energies of activation of viscous flow per mole of the solvents ( Δ μ 1 0 ≠ ) and of the solute ( Δ μ 2 0 ≠ ). Effects of molality, solute structure and temperature on all these parameters were analyzed in term of ion–ion and ion–solvent interactions; results revealed that the solutions are characterized predominantly by ion–solvent interactions and nicotinic acid behaves as a long-range structure maker.
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effect of paracetamol in aqueous Sodium Malonate solutions with reference to volumetric and viscometric measurements
The Journal of Chemical Thermodynamics, 2016Co-Authors: Abhijit Sarkar, Bijan Kumar Pandit, Biswajit SinhaAbstract:Abstract Apparent molar volumes and viscosity B-coefficients for paracetamol in aqueous Sodium Malonate solutions were determined from solution densities and viscosities measured at T = (298.15 to 318.15) K and at pressure p = 101 kPa as a function of paracetamol concentrations. The standard partial molar volumes ( ϕ V 0 ) and slopes ( S V ∗ ) obtained from Masson equation were interpreted in terms of (solute + solvent) and (solute + solute) interactions, respectively. Solution viscosities were analyzed using Jones–Dole equation and the viscosity A and B coefficients discussed in terms of (solute + solute) and (solute + solvent) interactions, respectively. The standard volume of transfer ( Δ t ϕ V 0 ) and viscosity B-coefficients of transfer ( Δ t B ) of paracetamol from water to aqueous Sodium Malonate solutions were derived to understand various interactions in the ternary solutions. The activation parameters of viscous flow for the studied solutions were discussed in terms of transition state theory. The structure making or breaking ability of Paracetamol was discussed in terms of the sign of ( d ϕ E 0 / dT ) P .
Alexander Mcpherson - One of the best experts on this subject based on the ideXlab platform.
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crystallization of brome mosaic virus and t 1 brome mosaic virus particles following a structural transition
Virology, 2001Co-Authors: Robert W. Lucas, Yurii G. Kuznetsov, Steven B. Larson, Alexander McphersonAbstract:Brome mosaic virus (BMV), a T = 3 icosahedral plant virus, can be dissociated into coat protein subunits and subunit oligomers at pH 7.5 in the presence of concentrated salts. We have found that during the course of this treatment the coat protein subunits are cleaved, presumably by plant cell proteases still present in the preparation, between amino acids 35 and 36. The truncated protein subunits will then reorganize into T = 1 icosahedral particles and can be crystallized from Sodium Malonate. Quasi elastic light scattering and atomic force microscopy results suggest that the transition from T = 3 to T = 1 particles can occur by separate pathways, dissociation into coat protein subunits and oligomers and reassembly into T = 1 particles, or direct condensation of the T = 3 virions to T = 1 particles with the shedding of hexameric capsomeres. The latter process has been directly visualized using atomic force microscopy. Native T = 3 virions have been crystallized in several different crystal forms, but neither a rhombohedral form nor either of two orthorhombic forms diffract beyond about 3.4 A. Tetragonal crystals of the T = 1 particles, however, diffract to at least 2.5 A resolution. Evidence suggests that the T = 1 particles are more structurally uniform and ordered than are native T = 3 virions. A variety of anomalous virus particles having diverse sizes have been visualized in preparations of BMV used for crystallization. In some cases these aberrant particles are incorporated into growing crystals where they are frequently responsible for defect formation.
Mitsuo Sawamoto - One of the best experts on this subject based on the ideXlab platform.
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selective single monomer addition in living cationic polymerization sequential double end functionalization in combination with capping agent
Journal of Polymer Science Part A, 2010Co-Authors: Takaya Terashima, Makoto Ouchi, Mitsuo SawamotoAbstract:Amine-functionalized and amine-carboxylate double-functionalized polymers (I and II, respectively) have been synthesized by a selective single addition of a protected 2-aminoethyl vinyl ether (BocVE) {CH 2 = CH[OCH 2 CH 2 N(Boc) 2 ]; Boc = t-butoxyearbonyl} onto a living cationic poly(n-butyl vinyl ether) [poly (NBVE)] initiated with the SnCl 4 /n-Bu 4 NCl system: (I) -(NBVE) n -CH 2C H(OCH 2 CH 2 NH 2 )-H ; (II) -(NBVE) n -CH 2 CH(OCH 2 CH 2 NH 2 )CH 2 CO 2 H. The single addition was examined with a set of alkene monomers less reactive than NBVE, including BocVE, 2-chloroethyl vinyl ether, 2-vinyloxyethylphtalimide, and styrene (St). Upon addition of 10 molar excess of these alkenes onto the living ends, only BocVE led to the intended single adduct, and this was attributed to a chelating interaction of the two carboxylate groups in the terminal BocVE unit with the growing poly(NBVE) terminal, thus sterically hampering further propagation. A simple acid-catalyzed Boc-deprotection led to the amino-functionalized version I. Alternatively, an additional quenching the BocVE-capped living end (the precursor of I) with Sodium Malonate, followed by double deprotection of the Boc and the Malonate groups gave the double-functionalized version II. The selective addition of a single monomer molecule is thus a new method for addressable or site-specific introduction of functional groups along polymer chains.
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selective single monomer addition in living cationic polymerization sequential double end functionalization in combination with capping agent part a polymer chemistry
Journal of Polymer Science, 2010Co-Authors: Shohei Ida, Takaya Terashima, Makoto Ouchi, Mitsuo SawamotoAbstract:Amine-functionalized and amine-carboxylate double-functionalized polymers (I and II, respectively) have been synthesized by a selective single addition of a protected 2-aminoethyl vinyl ether (BocVE) {CH₂ = CH[OCH₂CH₂N(Boc)₂]; Boc = t-butoxycarbonyl} onto a living cationic poly(n-butyl vinyl ether) [poly(NBVE)] initiated with the SnCl₄/n-Bu₄NCl system: (I) -(NBVE)n- CH₂CH(OCH₂CH₂NH₂)-H; (II) -(NBVE)n-CH₂CH(OCH₂CH₂NH₂)-CH₂CO₂H. The single addition was examined with a set of alkene monomers less reactive than NBVE, including BocVE, 2-chloroethyl vinyl ether, 2-vinyloxyethylphtalimide, and styrene (St). Upon addition of 10 molar excess of these alkenes onto the living ends, only BocVE led to the intended single adduct, and this was attributed to a chelating interaction of the two carboxylate groups in the terminal BocVE unit with the growing poly(NBVE) terminal, thus sterically hampering further propagation. A simple acid-catalyzed Boc-deprotection led to the amino-functionalized version I. Alternatively, an additional quenching the BocVE-capped living end (the precursor of I) with Sodium Malonate, followed by double deprotection of the Boc and the Malonate groups gave the double-functionalized version II. The selective addition of a single monomer molecule is thus a new method for addressable or site-specific introduction of functional groups along polymer chains.