Kinetics of the adsorption of hemoglobin on silica adsorbents with a bimodal distribution of pores

A comparative study of the adsorption kinetics of hemoglobin on silochrome and synthetic silicas with a bimodal distribution of pores is performed. The mechanism of adsorption is established and the presence of a reversible stage is demonstrated. The rate constants of adsorption, desorption, and irreversible binding are determined from the experimental data. The effect of synthesis conditions on the kinetic patterns of the adsorption process is shown.     

Dispersion relations for the hyperbolic thermal conductivity,thermoelasticity and thermoviscoelasticity

The Maxwell–Cattaneo heat conduction theory, the Lord–Shulman theory of thermoelasticity and a hyperbolic theory of thermoviscoelasticity are studied. The dispersion relations are analyzed in the case when a solution is represented in the form of an exponential function decreasing in time. Simple formulas that quite accurately approximate the dispersion curves are obtained. Based on the results of analysis of the dispersion relations, an experimental method of determination of the heat flux relaxation time is suggested.     

Formation of phthalocyanines deprotonated forms and their interaction with Zn Ions in the system 1,8-diazabicyclo[5.4.0]undec-7-ene-acetonitrile at 298 K

The formation of deprotonated forms of tetra(t-butyl)phthalocyanine ((H₂ tButPc) and octa(pentoxy)-phthalocyanine (H₂OAmPc) in the system acetonitrile-1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) at 298 K was studied by the method of spectrophotometric titration. With increasing DBU concentration sequential formation occurs of both mono- and douby deprotonated forms. The introduction of pentoxy groups into the fused benzene rings leads to a significant decrease in the acidity of the tetrapyrrole macrocycle compared with the tert-butyl substitution. The interaction of douby deprotonated forms of the phthalocyanines with zinc diacetate leads to the formation of metal complexes, the chelation constant of the latter is shown to correlate with the acidity of NH-protons in the nucleus of the macrocycle. For the chelation of more acidic tetra(t-butyl)-phthalocyanine an equimolar concentrations of zinc diacetate is sufficient, while the less acidic octa(pentoxy)-phthalocyanine requires almost 6-fold excess.     

New experimental data on the 10B(n, αt)4He reaction

A new technique is described that makes it possible to detect reaction products with the escape of charged particles occurring on components of working gas under the action of fast neutrons. This technique is unique since it offers the possibility of studying reactions for which more than two charged particles are generated in an output channel. This work studies interactions between neutrons and ¹⁰B nuclei, where two α-particles and tritium nucleus are produced as reaction products.     

Ion-selective and complexation properties, vibrational spectra, and crystal and molecular structure of 1,5-bis[2-(hydroxyethoxyphosphoryl)phenoxy]-3-oxapentane

The ion-selective properties of 1,5-bis[2-(hydroxyethoxyphosphoryl)phenoxy]-3-oxapentane H₂R² have been described. The molecular and crystal structure of H₂R² has been determined by powder X-ray crystallography and IR spectroscopy. The molecule has the twofold symmetry axis, orthorhombic crystal system, space group Pbcn, a = 16.830(2) ?, b = 8.866(15) ?, c = 15.7190(2) ?, V = 2346.1(6) ?³, Z = 4. A new CuR² · 2H₂O complex has been synthesized and characterized.     

Method of obtaining structured hydrocarbon gels for increasing the efficiency of oil spill recovery technologies

It was found that lithium tetraalkoxyborates are highly efficient gelling agents for hydrocarbons. The viscosity of liquid hydrocarbons can be increased to a desired degree by mixing them with a gelling composition of lithium tert-butoxide Li-O-C(CH₃)₃ and trialkoxyborate B(OC₈H₁₇)₃ in equimolecular amounts. Oil gelled by this composition has a rubberlike consistency, which retains its shape; therefore, oil spills treated with the use of this method can be more efficiently recovered mechanically or by hand.     

Composition and structure of platinum-containing thin composite films prepared from silica sols

Chemical processes that can occur during aging of sols based on water–alcohol solutions of tetraethoxysilane (TEOS) and hexachloroplatinic acid and during formation of films from these sols are analyzed by the results of visible and UV spectroscopy and X-ray powder diffraction. The sizes and compositions of the platinum particles that are formed in xerogels and in thin films on the nanometer and submicron levels are estimated based on X-ray crystallography, energy dispersive spectral analysis, high-resolution scanning and transmission electron microscopy, and grazing incidence small-angle X-ray scattering studies.     

Nonstationary transversal vibrations of thermoelastic web with a constant velocity motion

We consider axial movements of elastic web performing small transversal vibrations. We take into account thermal loadings on the moving web (panel) and determine the critical temperature providing the divergence (instability) of thermoelastic panel. We perform an analysis of non-stationary vibrations of the panel. Solving dynamical problem is based on application of Galerkin’s method. As an example, we present the analytical solution to the problem of nonstationary thermoelastic panel vibrations for the case of two shape functions.     

Study of the antioxidant activity and total polyphenol concentration of medicinal plants

Infusions of medicinal plants are investigated by potentiometry using a system of K₃[Fe(CN)₆]/K₄[Fe(CN)₆]. Models of some flavonoids, phenol carbonic acids, ascorbic acid, and their mixtures are studied. The total polyphenol concentration in these samples is determined by the Folin–Ciocalteu method. Dependences of antioxidant activity on extraction time are obtained.     

Carboxylated and decarboxylated nanotubes studied by X-ray photoelectron spectroscopy

Carbon nanotubes (CNTs) of the conic and cylindrical structure were studied by X-ray photoelectron spectroscopy in the initial state and after carboxylation and decarboxylation reactions. The O=C—O and C—O groups were revealed on the surface of the chemically modified samples. It was found that both the carboxylated and decarboxylated cylindrical CNTs contain a smaller amount of oxygen than the corresponding conic CNTs apparently due to differences in their structures.