Search results for "Names"

showing 10 items of 6843 documents

Fluorescence and color as markers for the Maillard reaction in milk–cereal based infant foods during storage

2007

Abstract Free and total fluorescence compounds and color formation were measured in three different milk–cereal based infant foods stored at 25, 30 and 37 °C for 9 months to evaluate the advanced and final stages of the Maillard reaction. Milk–cereal infant foods containing honey (B) or fruits (C) had fluorescent values higher than sample (A) without them. This difference could be ascribed to the higher monosaccharide (fructose and/or glucose) content of (B) and (C), which could increase susceptibility to the Maillard reaction. However, for color increase (ΔE), no significant differences (p

chemistry.chemical_classificationdigestive oral and skin physiologyFood preservationfood and beveragesFructoseGeneral MedicineFluorescenceAnalytical Chemistrychemistry.chemical_compoundMaillard reactionsymbols.namesakechemistrysymbolsMonosaccharideColor formationFood scienceFood ScienceFood Chemistry
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The Nonlocal Correlation Density Functional VV10

2015

Abstract In this chapter, we review the most relevant attempts to merge the Vydrov and van Voorhis nonlocal density-dependent functional kernel (VV10) with modern density functionals to accurately describe van der Waals interactions with a reasonable computational cost. The chapter is organized by providing first an introduction of the relevance of van der Waals interactions and the difficulties of common density functionals to describe these forces. Second, the historical developments that eventually give rise to the most modern formulation of the nonlocal density functional VV10 are briefly addressed. Then, an overview of its technical formulation, adjustable parameters, and implementatio…

chemistry.chemical_classificationsymbols.namesakeChemistryQuantum mechanicssymbolsNon-covalent interactionsDensity functional theoryStatistical physicsvan der Waals forceMerge (version control)
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Intrinsic Viscosities of Polyelectrolytes: Determination and Modeling of the Effects of Extra Salt

2011

Based on early measurements of J. J. Hermans and co-workers (D. T. F. Pals, J. J. Hermans, Recl. Trav. Chim. Pays-Bas 1952, 71, 513-520; D. T. F. Pals, J. J. Hermans, J. Polym. Sci. 1950, 5, 733-734; D. T. F. Pals, J. J. Hermans, J. Polym. Sci. 1948, 3, 897-898), the present contribution demonstrates how primary data should be evaluated in order to obtain reliable intrinsic viscosities. This procedure yields detailed information on the changes of the intrinsic viscosities and of the corresponding viscometric interaction parameters caused by an increasing salinity of water. Both quantities decline from a maximum value in the pure solvent to a minimum value, which is approached in the limit o…

chemistry.chemical_classificationsymbols.namesakechemistryBoltzmann constantSalt effectsymbolsSalt (chemistry)ThermodynamicsPhysical and Theoretical ChemistryAtomic and Molecular Physics and OpticsPolyelectrolyteDilutionChemPhysChem
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Effect of pulsed electric field on Maillard reaction and hydroxymethylfurfural production

2020

Abstract As an emerging nonthermal processing technology, the application of pulsed electric field (PEF) has received increasing attention not only for its capability to inactivate enzymes and microorganisms or to enhance mass transfer during the extraction process but also for its potential to inhibit the formation of chemical contaminants during processing, such as the formation of hydroxymethylfurfural (HMF). HMF is a potential carcinogen to humans that can be produced via the Maillard reaction (MR). Compared with thermal treatment, PEF can minimize the extent of MR, reducing the contents of HMF. However, in some cases, MR and HMR may be promoted, closely associated with PEF conditions a…

chemistry.chemical_compoundMaillard reactionsymbols.namesakechemistryFood productsElectric fieldsymbolsChemical contaminantsFood sciencerespiratory systemHydroxymethylfurfuralcirculatory and respiratory physiologyrespiratory tract diseases
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Low-lying Rydberg states of HCl.

2008

Vertical excitation energies belonging to some different Rydberg series of hydrogen chloride have been determined with a coupled-cluster theoretical approach. These excitation energies have allowed us to calculate electric dipole transition intensities in HCl and allow additional assessment of the calculation approach presently used to provide an adequate description of the valence and Rydberg states of HCl. The molecular quantum defect orbital has been applied to the calculation of oscillator strengths. In particular, new insight is given on the assignment of states as the R1Pi, the 1Delta(4dpi and 5ppi), the 1Sigma+(4dpi), and the nddelta(1Pi, 1Phi) and 4f states.

chemistry.chemical_compoundQuantum defectsymbols.namesakeValence (chemistry)chemistryRydberg atomRydberg formulasymbolsPhysical and Theoretical ChemistryElectric dipole transitionAtomic physicsHydrogen chlorideExcitationThe journal of physical chemistry. A
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Inelastic Neutron Scattering Experiments on Van der Waals Glasses - A Test of Recent Microscopic Theories of the Glass Transition

1989

Etude realisee sur un verre d'o-terphenyle afin de montrer l'existence d'une relaxation secondaire presentant des caracteristiques inhabituelles et le comportement Kohbrausch de la fonction de correlation de densite decrivant la relaxation structurale

chemistry.chemical_compoundsymbols.namesakeCondensed matter physicsChemistryGeneral Chemical EngineeringTerphenylCritical phenomenasymbolsInelastic scatteringNeutron scatteringvan der Waals forceGlass transitionInelastic neutron scatteringBerichte der Bunsengesellschaft für physikalische Chemie
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Towards a converged barrier height for the entrance channel transition state of the N(2D)+CH4 reaction and its implication for the chemistry in Titan…

2011

Abstract The N( 2 D) + CH 4 reaction appears to be a key reaction for the chemistry of Titan’s atmosphere, opening the door to nitrile formation as recently observed by the Cassini–Huygens mission. Faced to the controversy concerning the existence or not of a potential barrier for this reaction, we have carried out accurate ab initio calculations by means of multi-state multi-reference configuration interaction (MS-MR-SDCI) method. These calculations have been partially corrected for the size-consistency errors (SCE) by Davidson, Pople or AQCC corrections. We suggest a barrier height of 3.86 ± 0.84 kJ/mol, including ZPE, for the entrance transition state, in good agreement with the experime…

chemistry.chemical_compoundsymbols.namesakeNitrilechemistryAb initio quantum chemistry methodssymbolsGeneral Physics and AstronomyRectangular potential barrierPhysical and Theoretical ChemistryAtomic physicsConfiguration interactionTitan (rocket family)Entrance channelChemical Physics Letters
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Gold assisted oxygen dissociation on a molybdenum-doped CaO(001) surface

2016

Using density functional theory (DFT) calculations, we address the adsorption of O2 and the coadsorption of gold species and oxygen molecules on a Mo-doped CaO(001) surface with 1.25% impurity concentration. With the help of the Born–Haber thermodynamic cycle, the enhanced binding of an oxygen molecule on Ca(Mo)O is attributed to energy gain owing to simultaneous electron transfer from the dopant to the molecule and lattice relaxations. We consider three coadsorption structures for an Au atom and O2 molecule with different Au–O2 distances. The calculations demonstrate that the coadsorption structures take one electron from the dopant and the O–Au–O chain structure is thermodynamically more …

chemistry.chemical_element010402 general chemistry01 natural sciencesOxygenCatalysisDissociation (chemistry)oxygen dissociationCondensed Matter::Materials Sciencesymbols.namesakeElectron transferAdsorptionComputational chemistry0103 physical sciencesPhysics::Atomic and Molecular ClustersMoleculePhysics::Chemical Physics010306 general physicsta116ta114DopantChemistrygold0104 chemical sciencesGibbs free energyChemical physicssymbolsDensity functional theoryCatalysis Science & Technology
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Non-covalent graphene nanobuds from mono- and tripodal binding motifs.

2017

Graphene nanobuds were prepared via the non-covalent anchoring of C60-based molecules endowed with one or three pyrene units, respectively. TGA, FTIR, UV-Vis and TEM investigations confirmed the formation of nanohybrids. For the two molecular derivatives, striking differences were determined in their interaction with graphene or carbon surfaces by Raman, cyclic voltammetry and molecular mechanics calculations, revealing the important role of pyrene adsorption in modulating the electronic properties of the nanohybrids.

chemistry.chemical_element02 engineering and technology010402 general chemistry01 natural sciencesCatalysislaw.inventionsymbols.namesakechemistry.chemical_compoundAdsorptionlawMaterials ChemistryOrganic chemistryMoleculeFourier transform infrared spectroscopyGrapheneMetals and Alloystechnology industry and agricultureQuímica orgánicaGeneral Chemistry021001 nanoscience & nanotechnology0104 chemical sciences3. Good healthSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsCrystallographychemistryCeramics and CompositessymbolsPyreneCyclic voltammetry0210 nano-technologyRaman spectroscopyCarbonChemical communications (Cambridge, England)
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Growth, characterization, and high-pressure optical studies of CuWO4

2008

Copper tungstate (CuWO4) crystals grown by the top-seeded solution growth method were characterized by X-ray diffraction, Raman scattering, and optical measurements. CuWO4 has a triclinic structure (P 1¯) with a = 4.709 A, b = 5.845 A, c = 4.884 A, α = 88.3°, β = 92.5°, and γ = 97.2°. It consists of corner-linked CuO6 and WO6 octahedra, the former having a pseudo-tetragonally elongated geometry caused by the Cu2+ Jahn–Teller effect. Fifteen out of the eighteen Raman modes of CuWO4 are reported, discussed, and compared with those of other tungstates. We also determined the indirect band-gap energy of CuWO4 (2.3 eV) and its negative pressure coefficient up to 25 GPa. The pressure evolution of…

chemistry.chemical_elementElectronic structureCrystal structureTriclinic crystal systemCondensed Matter PhysicsCoppersymbols.namesakeCrystallographychemistry.chemical_compoundOctahedronchemistryTungstatesymbolsRaman spectroscopyRaman scatteringHigh Pressure Research
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