PIEZOQUARTZ GAS SENSORRESPONSE TO SOME HYDROCARBONS
S.S. Ryasenskii,N.V. Melnikov
Tver state University
Chair of inorganic and analytical chemistry
Proposed the design of the gas sensor based on quartz resonator. Shows the possibility of using it for defining the content of isooctane and hexane in the air.
Keywords:sensor, resonator, quartz micro balances.
ION-SELECTIVE ELECTRODE FOR DETERMINATION
OF DROTAVERIN DRUGS
G. I. Mantrov, I. V. Kobelinskii, S. S. Ryasenskii
TverStateUniversity
Chair of inorganic and analytical chemistry
The construction and electroanalytical characteristics of ion-selective electrode (ISE) for drotaverine hydrochloride are described. Ion association complexes of the drug were tested as electroactive materials for ionometric sensor controls. The ISE was used for direct potentiometry of drotaverine hydrochloride.
Keywords: ion-selective electrode, complexes, sensor, potentiometry.
WAYSOF LIGNIN PROCESSINGWITH BIO OIL OBTAINING
E.I.Shimanskaya,E.M.Sulman, A.AStepacheva, Yu.М. Lugovoy,
L.Zh.Nikoshvili
Tver State Technical University
Department ofBiotechnology andChemistry
This article examines theprocesses ofhydrogenolysisand oxidationas an alternative tothe pyrolysisof ligninduring processingto producebio.
Keywords:lingnin, hydrogenolysis, hydrotreating, oxidation, pyrolysis.
ЕFFECTS OF STRESS ON THE SKIN (OVERVIEW)
V.V.Zhigulina
Tver State Medical Academy
Department of Biochemistry with the Course of Clinical Laboratory Diagnostics
The article presents a survey of the literature relevant to the influence of stress on the structural changes in tissues, including the skin, and development of skin diseases. The present paper analyzes the data on stress proteins, provides the results of the changes in protein, carbohydrate and lipid indices of the skin under stress and during the post-stress period. New evidence has been received that under stressful conditions the number of common lipids and common phospholipids in the skin increases. Special attention is paid to the «delay» of the changes in the skin lipid components under water and immobilization stress, i.e. the first significant parameter changes occur approximately 24–48 h after stress.
Key words: stress, stress proteins, skin disorders, oxidative stress, immobilization stress
ELEMENTS OF PREVENTIVE DENTISTRY. IMPACT
OF FLUORIDE ON ORAL HEALTH PROMOTION AND SYSTEMIC FLUOROSIS PREVENTION
Yu.N. Borinsky1, B.N. Davydov2, E.Yu. Borinskaya1, N.V.Borinskaya3, V.V. Zhigulina1
Tver State Medical Academy
1 Department of Biochemistry with the Course of Clinical Laboratory Diagnostics Faculty of Postgraduate Studies
2 Department of Pediatric Dentistry
3 Women's consultation number 3
The objective of the study was to assess actual fluoride intake by exclusively breast-fed and mixed-fed infants, and offer a method of its correction for formula-fed infants to prevent systemic fluorosis.The study aimed at identifying sources of fluoride and its amount that a fetus receives during prenatal development and an infant receives after birth during exclusive breastfeeding, mixed feeding or formula feeding, and developing a method of fluoride intake correction for formula-fed infants.Results. The study reveals excessive (tens to hundreds of times higher than the safe level) fluoride intake in infants receiving formula feeding that eventually leads to high prevalence of systemic fluorosis in children and adults.Conclusion. Controlling fluoride intake by children based on their age is the best preventive oral health measure.
Keywords: fluoride, dental caries, fluorosis.
VALUE liquid complex Microelement additives. MODERNIZATION PROCESS FOR PRODUCING
FEED with its participation
V.V. Lebedev, G.Yu. Rabinovich
TSTU, Tver
Illustrates the use of the preparation of feed additives patented complex liquid containing succinic acid chelate with trace elements - iron, manganese, zinc, copper, cobalt, selenium, iodine, and methionine. Proven process and designed equipment allow you to enter the feed additive with a given concentration and the required performance.
Keywords:liquid complex additive, trace elements, technological scheme and equipment for the preparation of feed.
PROPERTIESOF CATIONICSURFACTANTS INTHE SOLUTION OF CHEMICALCOPPER PLATING
L.I.Voronchikhina,O.E. Zhuravlev,N.V. Verolaynen,N.I. Krotova,
I.A.Presnyakov
Tver State University
The properties ofthe cationicsurfactantspyridiniumserieswhich differin lengthand structure ofthe hydrocarbonradical.It has been establishedthat the testedsaltsresistantto hydrolysisplatingsolution. The presence ofcomponentsof copper platingsolutionhas no effect onthe colloid-chemical properties examinedsalts.
Keywords:surfactants, plating,copper plating.
SYNTHESIS, SPECTRALCHARACTERISTICS
ANDPHYSICOCHEMICALPROPERTIES
OF TETRACHLOROFERRATE (III) N-DETSILPIRIDINIUM
O.E. Zhuravlev, L.I. Voronchihina, N.I. Krotova
Tver State University
Synthesizedlow-temperatureionic liquidtetrachloroferrate(III) N-detsilpiridinium. The dependence ofdensity andabsolute viscositywith temperature.Investigated the thermalstability andmagnetic properties of ionic liquid.Quantum-chemicalcalculations of the structuredensity functionalDFTlibraryB3LYBusing the basis6-31G (d, p) .
Keywords:ionic liquids, paramagnetism, quantum-chemical calculations, thermal stability, physicochemical properties, tetrachloroferrate.
STUDY OF FREE RADICALS ELECTRONIC STRUCTURE
IN FRAMEWORK quantum theory
of atoms in molecule. 1-alken-1-ils.
V.N. Sitnikov1, E. M. Chernova1, V. V. Turovtsev1.2, Yu. D. Orlov1
1Tver state university
2Tver state medical academy
Equilibrium structures of CH3(CH2)nCH=CH free radicals were found by method B3LYP/6-311++G(3df, 3pd), and their electronic density distributions were studied in framework of «quantum theory of atoms in molecule» (QTAIM).
Keywords: quantum theory of atoms in molecule, electron density distribution, inductive effect, charges at atoms, spin density, relation «structure - property».
STUDY OF FREE RADICALS ELECTRONIC STRUCTURE
IN FRAMEWORK QTAIM. 1-alken-2-ils
V.N. Sitnikov1, E. M. Chernova1, V. V. Turovtsev1.2, Yu. D. Orlov1
1Tver state university
2Tver state medical academy
Equilibrium structures of CH3(CH2)nC=CH2 free radicals were found by method B3LYP/6-311++G(3df, 3pd), and their electronic density distributions were studied in framework of «quantum theory of atoms in molecule» (QTAIM).
Keywords: quantum theory of atoms in molecule, electron density distribution, inductive effect, charges at atoms, spin density, relation «structure - property».
Self-assembly in Thin Block Copolymer Films
I. Neratova
Ulm University, Ulm, Germany
Leibniz Institute of Polymer Research, Dresden, Germany
Solvent evaporation from symmetric diblock copolymer solution was simulated by dissipative particle dynamics. The kinetics of lamella phase formation upon solvent evaporation process was compared with the self-assembly in a diblock copolymer melt. The role of a solvent during the evaporation process is discussed. It was found that during the solvent evaporation process the equilibrium morphology is reached escaping local energy minima, whereas the self-assembly of diblock copolymers in a melt is following different kinetic paths with many metastable states.
Keywords:dissipative particle dynamics, diblock copolymer film, lamellar phase, solvent evaporation.
RAPIDMETHODASSESSINGRATIOOFENANTIOMERES
OFLACTICACIDCYCLICDIMERS
L.E. Karpukhin, V.M. Spiridonova, E.A. Brovina, T.I. Samsonova,
A.G. Petrov, S.I. Shkurenko
AO «VNIISV», Tver
The formation ofself-crystalline phaseof the racemic mixture of optically active isomers of lactide was discovered.The crystals of this phase is significantly different from the crystals of optically pure enantiomers, which allows the use of optical microscopy as a rapid method for assessing the quality of lactide.
Keywords: lactic acid, microscopy, lactide.
COLDcuring OFVInylester resins
and meaning of postcure process
I.I. Spiridonov1,2, E.I. Laguseva1
1TSTU, Tver
2JSC "Tverstekloplastik", Tver
The mechanism of curing vinyl ester resins has been reviewed as an irreversible process.The change of the surface hardness of the samples as a function of time and temperature of postcure has been studied. The study is important in the manufacture of large and thick-walled composite products and constructions.
Keywords: vynil ester resin, surface hardness, postcure.
APPLICATION OF ELECTROLYTE MODELS
FOR CORRELATION OF VAPOR-LIQUID EQUILIBRIUM DATA
IN THE TERNARY SYSTEMS
«METHANOL – ACETONE – ALKYLPYRIDINIUM SALT»
A.N. Evdokimov, A.V. Kurzin, A.D. Trifonova, M.A. Radin,
O.V. Fedorova
Saint-Petersburg State Technological University of Plant Polymers
Institute of Technology
Electrolyte models NRTL, UNIQUAC и UNIFAC were used for correlation of vapor-liquid equilibrium data in the systems methanol – acetone – N-butylpyridinium hexafluorophosphate and methanol – acetone – N-benzylpyridinium tetrafluoroborate. These models represent the experimental data with required accuracy. Average mean absolute deviations of mole fraction of solvents in vapor phase were 0,006–0,008.
Keywords:vapor-liquid equilibrium, methanol, acetone, N-butylpyridinium hexafluorophosphate, N-benzylpyridinium tetrafluoroborate, electrolyte models, NRTL, UNIQUAC, UNIFAC.
INFLUENCEOFimmersionliquidonUVspectraofporouspolymericmaterials
V.E. Sitnikova, S.D. Khizhnyk, I. S. Kuryndin, G. K. Elyashevich,
P.M. Pakhomov
1Tver State University, Tver
2 Institute of Macromolecular Compounds, Russian Academy of Science, St. Petersburg
The effect of immersion liquid on the scattering in the UV spectra of porous films of polyethylene, track membranes of PP and PET with different pore sizes was investigated using a spectroscopic approach. It is shown that for the leveling effect of scattering, can be used an immersion liquids with a refractive index close to the value of the refractive index of the sample and with affinity between the liquid and the sample.
Keywords: porous PE film, the spectroscopic approach, total porosity, pore size distribution
InvestIgation of the electron structure
of La(Fe1-хCoх)Siy COMPOUNDS BY MEANS OF Hall effect
D.Yu. Karpenkov1, F.O.Denisov1, K.P.Skokov2, E.L.Airiyan1,
A.Yu.Karpenkov1, Yu.G.Pastushenkov 1
1Tver State University
Department of Magnetism
2 Technical University of Darmstadt, Darmstadt, Germany
Investigation the electron structure of La(Fe1-хCoх)Siy compounds was studied by means of anomalous and normal Hall effect in a wide range of magnetic field and temperatures. It was found that for alloys, characterized with the first order transition from ferromagnetic state to paramagnetic state, the main mechanism of conductivity is hole conductivity. In the vicinity of the Curie point the sign of normal Hall effect coefficient tends to change. With the substitution of iron atoms with cobalt in these compounds together with change of order of phase transition a change to the electron conductivity is observed. Anomalous Hall effect in these compounds is mainly determined by the contribution from the external skew scattering mechanism.
Keywords: anomalous and normal Hall effect, the electronic structure, materials for magnetic refrigeration.
Microstructureandmagneticdomain
structureofСо3В
O.V. Zhdanova, M.B. Lyakhova, E.M. Semenova, D.Yu. Karpenkov, A.Yu. Karpenkov
Tver State University
The microstructures and magnetic domain structures of coarse-grained Co-B alloy were examined with optical microscopy and scanning electron microscopy. It was shownthat Co3B phase contain stripe domain structure and branching of magnetic domains. Co3B magnetic domain structure is typical for orthorhombic ferromagnetic.
Keywords:metallography, microstructure, magnetic domain structure, ferromagnetic