Fine Chemical Technologies

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Vol 12, No 1 (2017)
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5-25 558
Ultrafast laser spectral and electron diffraction methods complement each other and open up new possibilities in chemistry and physics to light up atomic and molecular motions involved in the primary processes governing structural transitions. Since the 1980s, scientific laboratories in the world have begun to develop a new field of research aimed at this goal. “Atomic-molecular movies” will allow visualizing coherent dynamics of nuclei in molecules and fast processes in chemical reactions in real time. Modern femtosecond and picosecond laser sources have made it possible to significantly change the traditional approaches using continuous electron beams, to create ultrabright pulsed photoelectron sources, to catch ultrafast processes in the matter initiated by ultrashort laser pulses and to achieve high spatio-temporal resolution in research. There are several research laboratories all over the world experimenting or planning to experiment with ultrafast electron diffraction and possessing electron microscopes adapted to operate with ultrashort electron beams. It should be emphasized that creating a new-generation electron microscope is of crucial importance, because successful realization of this project demonstrates the potential of leading national research centers and their ability to work at the forefront of modern science.
26-30 380
For the first time, a complex of bismuth(III) with iodine and etioporphyrin II is reported. It was prepared by reacting etioporphyrin II and bismuth(III) iodide in pyridine in Ar atmosphere. The prepared compound was characterized by FT-IR, 1H-NMR, UV-VIS spectroscopy and mass spectrometry. One intense line at m/z 684.990 attributed to the complex without the iodine atom is observed in the mass spectrum. This is in agreement with the data indicating that bismuthporphyrin complexes generally have low stability. Analysis of FT-IR spectra obtained at room temperature and at 145°С is reported. Priroda15 DFT package was used for optimization of complex geometry and calculation of the IR spectrum. Calculations were done using BPE functional and L1 basis set under relativistic approximation of Dyall Modified Dirac. Assignment of the vibrational frequencies is reported. Collected data indicate that the complex of bismuth(III) with iodine and etioporphyrin II is not stable and easily hydrolyses when exposed to air forming the corresponding hydroxocomplex. This transformation does not change significantly the dynamics of the porphyrin ring.
31-38 314
This article describes a new method of thermochemical synthesis of luminescent nanostructured powders of Y2O3:Eu3+ and Y2O3:Bi3+, Eu3+ based on the burning of nitrate salts in the presence of a complex organic fuel consisting of a mixture of carbamide and hexamethylenetetramine (HMTA). It is established that using a combined fuel - a mixture of carbamide and HMTA - in a thermochemical reaction followed by calcination of the precursor at 650ºC gives more friable powders than the reaction with pure carbamide as a fuel, with a large amount of cavities. It is shown that when preparing Y2O3:Eu3+powders, complex compounds of anhydrous nitrates Y(NО3)3∙3СO(NH2)2 and Eu(NO3)3∙6CO(NH2)2 with urea are formed at the gel stage. They are decomposed at a higher temperature (about 1200ºС) resulting from the combustion process. As a result, corresponding crystalline oxides are formed. The europium ions replace a part of the yttrium ions in the structure of Y2O3 favouring the formation of a luminescent powder. X-ray diffraction, scanning electron microscopy, and photoluminescence spectroscopy have been used to characterize these powders. The powders synthesized in this manner (calcination at 650ºC) show a sharp peak in the X-ray diffraction picture at 2θ = 28.94° corresponding to crystalline Y2O3 particles with average particle size 62.3 nm. However, when treatment temperature is increased to 1200ºC, and the process duration is 1 h, the average particle size increases to 0.25 microns. Measurement of photoluminescence spectra of the samples revealed a maximum in the red region (λ=612 nm) when exciting at a wavelength of 395 nm (violet radiation). Luminescence intensity increases by 15% when introducing bismuth ions into the Y2O3 matrix and decreases by 30% when calcinating the Y2O3:Eu3+ powders at 1100ºС. The nanostructured Y2O3:Bi3+, Eu3+ powders obtained by the burning method can be applied in systems for protecting valuable security and industrial products, because these powders have special luminescent characteristics allowing to make visual observation of texts and tags under the radiation of LED sources without application of UV-lamps.
39-44 330
The main stages of bismuth telluride processing comprising sintering with NaOH, leaching and precipitation were investigated. Bi2Te3 samples produced by "ADV Engineering" were used as starting compounds. The studies revealed regularities of tellurium behavior during the sintering of Bi2Te3 with NaOH and the resulting the solid residue leaching. It was noted that annealing at 350-450°C with NaOH transforms tellurium into Na2TeO3, which is an appropriate form for further dissolution and separation from bismuth. Increasing temperature results in Na2TeO3 oxidation and formation of the water-insoluble compound Na2TeO4. Thus, it decreases tellurium extraction degree during the leaching. It has been shown that increasing temperature from 8 to 25°C at the step of tellurium hydrolytic precipitation slightly affects the extraction degree, the value of which is 93.5-98.2%.


45-49 296
The method of calculation of the intensity of heat removal from the surface of the crystallizing melt droplets is presented. A comparison with the experimental fixed values representing the intensity of the heat transfer between the surface of the resulting pellet and cooling agent is carried out. The influence of heat transfer coefficient on the surface of the pellet changes on complete crystallization time, and therefore on the size of the granulation tower, is analyzed. Conditions defining the heat transfer between the granule surface and surrounding coolant, while full crystallization in conjunction with the dependence of the rate of nucleation and growth of the granules determine mechanical properties of ammonia fertilizer granules.
50-56 272
In this paper we propose an option of an energy-saving scheme for the two-stage recrystallization of substances from aqueous solutions with regeneration of the solvent from the final solutions by evaporation using a closed-type heat pump and recuperative heat exchange between the mass flows. Theoretical equations describing this process were derived. On the basis of these dependences we carried out analysis of the impact of some parameters on potassium nitrate recrystallization from aqueous solutions. It was found that the regeneration of the solvent from the final solutions allows reducing significantly the consumption of fresh solvent for the purification process. It was shown that the use of heat pumps at the stage of the solvent extraction from the final solutions combined with recuperative heat exchange between the mass flows is energetically most advantageous in most technological regimes. This is confirmed by high values of the energy conversion coefficient and low values (<1) of relative consumption of reference fuel. It was found that an additional stage of the product crystallization of from the evaporated solution allows increasing the output of refined products almost by a factor of 1.3. This has a positive effect on the technical and economic indicators of the purification process.


57-63 346
A method for the synthesis of 2-(2-(dialkylamino)ethylamino)ethanols based on the epoxide ring opening in styrene oxide by N,N-disubstituted ethylenediamines was developed. It is shown that the opening of the oxirane ring by diamines in 2-propanol at room temperature occurs mainly according to the Krasusky rule at the bond between the oxygen atom and the less substituted carbon atom. A mixture of two products with the predominance of the secondary diamino alcohol up to 82% was obtained. It was found that the separation of the products by distillation or recrystallization does not allow obtaining pure isomers. The mixture of isomers was converted into dihydrochlorides by dry HCl in dioxane and diethyl ether. Pure 2-(2-(dialkylamino)ethylamino)-1-phenylethanols and 2-(2-(dialkylamino)ethylamino)-2-phenylethanols were separated by the first fractional recrystallization of a mixture of diaminoalcohol dihydrochlorides from a mixed solvent followed by alkalization of the products with an aqueous sodium hydroxide solution. The diamino alcohols were characterized by FT-IR, 1H- and 13C-NMR and HRMS-ESI.


64-75 364
The article presents the results of the first stage of development of a new quantitative method for human chorionic gonadotropin (hCG) determination by means of ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) to uncover doping abuse by athletes. The identified tryptic peptides correspond to the most abundant hCG isoforms: the α- and β-subunits, the nicked and β-core fragment of the hormone. Identification and sequencing of specific fragments were performed with the use of nanoLC-MS/MS. A high resolution / high accuracy hybrid mass-spectrometer was applied. Optimization of mass-spectrometric determination of selected specific peptides was accomplished by UPLC-MS/MS. Quantitative evaluation of hCG using specific fragments determination by UPLC-MS/MS allows to detect corresponding hCG isoforms. This significantly increases the method specificity and decreases the probability of false-positive results.
76-82 313
The determination of cypermethrin, one of the most sought pyrethroid insecticides having a wide range of activities, by isocratic RP-HPLC is considered. The analysis of substances (technical products) with different content of both the geometrical (cis-, trans-) and optical (zetacypermethrin and alfacypermethrin) isomers of cypermethrin was carried out. Information about the content of the most active forms of cis- allows evaluating the effectiveness of the biological substance based only on RP-HPLC data, which in turn can be a decisive factor in the of the substance assessment supplier / manufacturer or ready commercial products. The optimum concentration range for determining the geometric isomers of cypermethrin in the working solution is from 0.2 to 1.0 mg/ml. The substance detection limit in working solutions/washings is 0.005 mg/ml.


83-88 281
The article considers a new class of model representations in the theory of oscillation of systems described by the classical boundary value problems for hyperbolic equations. The peculiarity of the suggested approach consists in the introduction of an additional term into the basic equation of oscillations. This term characterizes the presence of a temperature gradient in the systems. The developed theory is applicable to longitudinal oscillations of a rod, but can be extended just as well to the problem of the vibrations of strings, membranes, shaft torsional oscillations, electromagnetic waves, etc. Numerical experiments showed a significant effect of the temperature field in the rod on the nature of the vibrations and displacements of the rod cross-sections in comparison with classical solutions.
89-95 348
The article describes the main aspects concerning the development of the corporate information system for logistics management of petrochemical enterprises. The functional and conceptual models of petrochemical products supply management have been composed. The authors suggest using modular design of an information system based on ERP Galaktika. Advantages of applying the client/server architecture and object-relational data model to corporate information systems are outlined. The authors recommend using ABC/XYZ analysis as the method of classifying inventory by sales and products levels to determine the optimal inventory control strategy.

ISSN 2410-6593 (Print)
ISSN 2686-7575 (Online)