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MATHEMATICS (647 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 538 Journals sorted alphabetically
Abakós     Open Access   (Followers: 3)
Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg     Hybrid Journal   (Followers: 2)
Academic Voices : A Multidisciplinary Journal     Open Access   (Followers: 2)
Accounting Perspectives     Full-text available via subscription   (Followers: 7)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Mathematical Software (TOMS)     Hybrid Journal   (Followers: 6)
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 21)
Acta Applicandae Mathematicae     Hybrid Journal   (Followers: 1)
Acta Mathematica     Hybrid Journal   (Followers: 11)
Acta Mathematica Hungarica     Hybrid Journal   (Followers: 2)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5)
Acta Mathematica Sinica, English Series     Hybrid Journal   (Followers: 5)
Acta Mathematica Vietnamica     Hybrid Journal  
Acta Mathematicae Applicatae Sinica, English Series     Hybrid Journal  
Advanced Science Letters     Full-text available via subscription   (Followers: 5)
Advances in Applied Clifford Algebras     Hybrid Journal   (Followers: 3)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15)
Advances in Decision Sciences     Open Access   (Followers: 4)
Advances in Difference Equations     Open Access   (Followers: 1)
Advances in Fixed Point Theory     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Linear Algebra & Matrix Theory     Open Access   (Followers: 1)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Mathematical Physics     Open Access   (Followers: 6)
Advances in Mathematics     Full-text available via subscription   (Followers: 10)
Advances in Numerical Analysis     Open Access   (Followers: 4)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Pure and Applied Mathematics     Hybrid Journal   (Followers: 5)
Advances in Pure Mathematics     Open Access   (Followers: 4)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aequationes Mathematicae     Hybrid Journal   (Followers: 2)
African Journal of Educational Studies in Mathematics and Sciences     Full-text available via subscription   (Followers: 5)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Afrika Matematika     Hybrid Journal   (Followers: 1)
Air, Soil & Water Research     Open Access   (Followers: 7)
AKSIOMA Journal of Mathematics Education     Open Access   (Followers: 1)
Algebra and Logic     Hybrid Journal   (Followers: 3)
Algebra Colloquium     Hybrid Journal   (Followers: 4)
Algebra Universalis     Hybrid Journal   (Followers: 2)
Algorithmic Operations Research     Full-text available via subscription   (Followers: 5)
Algorithms     Open Access   (Followers: 9)
Algorithms Research     Open Access   (Followers: 1)
American Journal of Biostatistics     Open Access   (Followers: 9)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 3)
American Journal of Mathematical Analysis     Open Access  
American Journal of Mathematics     Full-text available via subscription   (Followers: 7)
American Journal of Operations Research     Open Access   (Followers: 5)
American Mathematical Monthly     Full-text available via subscription   (Followers: 6)
An International Journal of Optimization and Control: Theories & Applications     Open Access   (Followers: 7)
Analele Universitatii Ovidius Constanta - Seria Matematica     Open Access   (Followers: 1)
Analysis     Hybrid Journal   (Followers: 2)
Analysis and Applications     Hybrid Journal   (Followers: 1)
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 4)
Analysis Mathematica     Full-text available via subscription  
Annales Mathematicae Silesianae     Open Access  
Annales mathématiques du Québec     Hybrid Journal   (Followers: 4)
Annales UMCS, Mathematica     Open Access   (Followers: 1)
Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica     Open Access  
Annali di Matematica Pura ed Applicata     Hybrid Journal   (Followers: 1)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 8)
Annals of Discrete Mathematics     Full-text available via subscription   (Followers: 6)
Annals of Mathematics     Full-text available via subscription  
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 6)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of the Alexandru Ioan Cuza University - Mathematics     Open Access  
Annals of the Institute of Statistical Mathematics     Hybrid Journal   (Followers: 1)
Annals of West University of Timisoara - Mathematics     Open Access  
Annuaire du Collège de France     Open Access   (Followers: 5)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applications of Mathematics     Hybrid Journal   (Followers: 1)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Mathematics     Open Access   (Followers: 3)
Applied Mathematics     Open Access   (Followers: 4)
Applied Mathematics & Optimization     Hybrid Journal   (Followers: 4)
Applied Mathematics - A Journal of Chinese Universities     Hybrid Journal  
Applied Mathematics Letters     Full-text available via subscription   (Followers: 1)
Applied Mathematics Research eXpress     Hybrid Journal   (Followers: 1)
Applied Network Science     Open Access  
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arab Journal of Mathematical Sciences     Open Access   (Followers: 2)
Arabian Journal of Mathematics     Open Access   (Followers: 2)
Archive for Mathematical Logic     Hybrid Journal   (Followers: 1)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 4)
Archive of Numerical Software     Open Access  
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
Arnold Mathematical Journal     Hybrid Journal   (Followers: 1)
Artificial Satellites : The Journal of Space Research Centre of Polish Academy of Sciences     Open Access   (Followers: 18)
Asia-Pacific Journal of Operational Research     Hybrid Journal   (Followers: 3)
Asian Journal of Algebra     Open Access   (Followers: 1)
Asian Journal of Current Engineering & Maths     Open Access  
Asian-European Journal of Mathematics     Hybrid Journal   (Followers: 2)
Australian Mathematics Teacher, The     Full-text available via subscription   (Followers: 7)
Australian Primary Mathematics Classroom     Full-text available via subscription   (Followers: 2)
Australian Senior Mathematics Journal     Full-text available via subscription   (Followers: 1)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Axioms     Open Access  
Baltic International Yearbook of Cognition, Logic and Communication     Open Access  
Basin Research     Hybrid Journal   (Followers: 3)
BIBECHANA     Open Access  
BIT Numerical Mathematics     Hybrid Journal  
BoEM - Boletim online de Educação Matemática     Open Access  
Boletim Cearense de Educação e História da Matemática     Open Access  
Boletim de Educação Matemática     Open Access  
Boletín de la Sociedad Matemática Mexicana     Hybrid Journal  
Bollettino dell'Unione Matematica Italiana     Full-text available via subscription   (Followers: 1)
British Journal of Mathematical and Statistical Psychology     Full-text available via subscription   (Followers: 21)
Bruno Pini Mathematical Analysis Seminar     Open Access  
Buletinul Academiei de Stiinte a Republicii Moldova. Matematica     Open Access   (Followers: 7)
Bulletin des Sciences Mathamatiques     Full-text available via subscription   (Followers: 4)
Bulletin of Dnipropetrovsk University. Series : Communications in Mathematical Modeling and Differential Equations Theory     Open Access   (Followers: 1)
Bulletin of Mathematical Sciences     Open Access   (Followers: 1)
Bulletin of the Brazilian Mathematical Society, New Series     Hybrid Journal  
Bulletin of the London Mathematical Society     Hybrid Journal   (Followers: 3)
Bulletin of the Malaysian Mathematical Sciences Society     Hybrid Journal  
Calculus of Variations and Partial Differential Equations     Hybrid Journal  
Canadian Journal of Science, Mathematics and Technology Education     Hybrid Journal   (Followers: 17)
Carpathian Mathematical Publications     Open Access   (Followers: 1)
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal  
CHANCE     Hybrid Journal   (Followers: 5)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
ChemSusChem     Hybrid Journal   (Followers: 7)
Chinese Annals of Mathematics, Series B     Hybrid Journal  
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Mathematics     Open Access  
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Cogent Mathematics     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Collectanea Mathematica     Hybrid Journal  
College Mathematics Journal     Full-text available via subscription   (Followers: 2)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Commentarii Mathematici Helvetici     Hybrid Journal   (Followers: 1)
Communications in Contemporary Mathematics     Hybrid Journal  
Communications in Mathematical Physics     Hybrid Journal   (Followers: 1)
Communications On Pure & Applied Mathematics     Hybrid Journal   (Followers: 3)
Complex Analysis and its Synergies     Open Access   (Followers: 2)
Complex Variables and Elliptic Equations: An International Journal     Hybrid Journal  
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 9)
Comptes Rendus Mathematique     Full-text available via subscription   (Followers: 1)
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 5)
Concrete Operators     Open Access   (Followers: 4)
Confluentes Mathematici     Hybrid Journal  
COSMOS     Hybrid Journal  
Cryptography and Communications     Hybrid Journal   (Followers: 14)
Cuadernos de Investigación y Formación en Educación Matemática     Open Access  
Cubo. A Mathematical Journal     Open Access  
Czechoslovak Mathematical Journal     Hybrid Journal   (Followers: 1)
Demographic Research     Open Access   (Followers: 12)
Demonstratio Mathematica     Open Access  
Dependence Modeling     Open Access  
Design Journal : An International Journal for All Aspects of Design     Hybrid Journal   (Followers: 29)
Developments in Clay Science     Full-text available via subscription   (Followers: 1)
Developments in Mineral Processing     Full-text available via subscription   (Followers: 3)
Dhaka University Journal of Science     Open Access  
Differential Equations and Dynamical Systems     Hybrid Journal   (Followers: 2)
Discrete Mathematics     Hybrid Journal   (Followers: 7)
Discrete Mathematics & Theoretical Computer Science     Open Access  
Discrete Mathematics, Algorithms and Applications     Hybrid Journal   (Followers: 2)
Discussiones Mathematicae Graph Theory     Open Access   (Followers: 1)
Doklady Mathematics     Hybrid Journal  
Duke Mathematical Journal     Full-text available via subscription   (Followers: 1)
Edited Series on Advances in Nonlinear Science and Complexity     Full-text available via subscription  
Electronic Journal of Graph Theory and Applications     Open Access   (Followers: 2)
Electronic Notes in Discrete Mathematics     Full-text available via subscription   (Followers: 2)
Elemente der Mathematik     Full-text available via subscription   (Followers: 3)
Energy for Sustainable Development     Hybrid Journal   (Followers: 9)
Enseñanza de las Ciencias : Revista de Investigación y Experiencias Didácticas     Open Access  
Ensino da Matemática em Debate     Open Access  
Entropy     Open Access   (Followers: 5)
ESAIM: Control Optimisation and Calculus of Variations     Full-text available via subscription   (Followers: 1)
European Journal of Combinatorics     Full-text available via subscription   (Followers: 4)
European Journal of Mathematics     Hybrid Journal   (Followers: 1)
European Scientific Journal     Open Access   (Followers: 2)
Experimental Mathematics     Hybrid Journal   (Followers: 3)
Expositiones Mathematicae     Hybrid Journal   (Followers: 2)
Facta Universitatis, Series : Mathematics and Informatics     Open Access  
Fasciculi Mathematici     Open Access  
Finite Fields and Their Applications     Full-text available via subscription   (Followers: 4)
Fixed Point Theory and Applications     Open Access   (Followers: 1)
Formalized Mathematics     Open Access   (Followers: 2)
Foundations and Trends® in Econometrics     Full-text available via subscription   (Followers: 4)

        1 2 3 4 | Last

Journal Cover Catalysis in Industry
  [SJR: 0.182]   [H-I: 7]   [1 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 2070-0555 - ISSN (Online) 2070-0504
   Published by Springer-Verlag Homepage  [2345 journals]
  • Modern hydroprocesses for the synthesis of high-quality low-viscous marine
    • Authors: N. K. Kondrasheva; D. O. Kondrashev
      Pages: 1 - 9
      Abstract: Basic physicochemical and service properties inherent in middle distillate fractions from hydrocatalytic and thermodestructive processes are studied for one Russian refinery from the viewpoint of using them as potential components for low-viscous marine fuels (LMFs) with improved environmental and low-temperature properties. A laboratory-scale flow-through setup loaded with an industrial nickel–molybdenum catalyst is used for the hydrocracking of vacuum gasoils (with T ebp ranging from 500 to 580°C) at 340–380°C and 15.0 MPa. The highest yield of the light hydrocracking gasoil (LHCG) is observed upon the processing of vacuum gasoil (T ebp, 350–500°C) at 360°C, the highest cetane index (53 points) and the lowest sulfur content (7 ppm) being characteristic of the obtained LHCG. With heavier vacuum gasoil, the total yields of target distillates and the yield of LHCG decrease. In terms of physicochemical and service properties, the obtained LHGC is a high-quality component of LMFs. Comparative properties of the hydrorefined virgin diesel fraction, light gasoils obtained via catalytic cracking, slow coking, and the promising hydrocracking process are analyzed. The physicochemical, environmental, and main service properties inherent in the middle distillate fractions of secondary processes are determined depending on their hydrocarbon and nonhydrocarbon compositions, and on the content of key components. Based on these dependences, recommendations are made for the production of optimum low-viscous marine fuels with improved environmental and low-temperature properties.
      PubDate: 2017-01-01
      DOI: 10.1134/s207005041701007x
      Issue No: Vol. 9, No. 1 (2017)
  • Modeling the reforming of straight-run gasoline (fraction 85–140°C)
           with allowance for the deactivation of Pt catalyst
    • Authors: A. A. Dyusembaeva; V. I. Vershinin
      Pages: 10 - 16
      Abstract: A kinetic model of reforming is developed that describes the chemical transformations of С6–С8 pseudocomponents over Pt catalyst. The composition of platformate is predicted in light of the activity of the metal and acid sites, and temperature profile in the reactors. Equations of mass and heat balance are used in the calculations. The rate constants and activation energies of individual reactions are determined for catalyst of the R-134 series. The stationary activity values (a s = 0.8) are calculated along with the constants of the deactivation of acid (0.0056 ± 0.0004 min−1) and metal (0.079 ± 0.003 min−1) sites at Т = 490°C. The relative error of platformate composition modeling for benzene, toluene, and xylenes does not exceed 5%. It is shown that the stability of platformate composition is due to a stepwise temperature increase in the reactors during the periods between regenerations. It is proposed that the developed model be used to select temperature regimes for the operation of aromatic-producing industrial complexes in order to obtain platformate of desired compositions.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010056
      Issue No: Vol. 9, No. 1 (2017)
  • Pilot tests of the microspherical aluminochromium KDI-M catalyst for iso
           -butane dehydrogenation
    • Authors: A. A. Lamberov; S. R. Egorova; Kh. Kh. Gilmanov; A. N. Kataev; G. E. Bekmukhamedov
      Pages: 17 - 22
      Abstract: Results from pilot tests of microspherical aluminochromium KDI-M catalyst mixed with IM-2201 in a large-scale unit (Nizhnekamskneftekhim) for iso-butane dehydrogenation are discussed. Compared to KDI catalyst, its modified analogue KDI-M is more active and selective; the optimized grain-size composition and mechanical strength ensures higher yields of iso-butylene and longer nonstop operation (up to 400 days) of the reactor unit.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010093
      Issue No: Vol. 9, No. 1 (2017)
  • Ruthenium promoted cobalt–alumina catalysts for the synthesis of
           high-molecular-weight solid hydrocarbons from CO and hydrogen
    • Authors: O. A. Kungurova; N. V. Shtertser; G. K. Chermashentseva; I. I. Simentsova; A. A. Khassin
      Pages: 23 - 30
      Abstract: The effect of the ruthenium promotion of Fischer–Tropsch (FT) cobalt–alumina catalysts on the temperature of catalyst activation reduction and catalytic properties in the FT process is studied. The addition of 0.2–1 wt % of ruthenium reduces the temperature of reduction activation from 500 to 330–350°C while preserving the catalytic activity and selectivity toward C5+ products in FT synthesis. FT ruthenium-promoted Co–Al catalysts are more selective toward higher hydrocarbons; the experimental value of parameter αASF of the distribution of paraffinic products for ruthenium-promoted catalysts is 0.93–0.94, allowing us to estimate the selectivity toward C20+ synthetic waxes to be 48 wt %, and the selectivity toward C35+ waxes to be 23 wt %. Ruthenium-promoted catalysts also exhibit high selectivity toward olefins.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010081
      Issue No: Vol. 9, No. 1 (2017)
  • Supercritical fluid CO 2 -extraction regeneration of nickel–molybdenum
           catalyst for hydrotreatment
    • Authors: Ameer Abed Jaddoa; T. R. Bilalov; F. M. Gumerov; F. R. Gabitov; Z. I. Zaripov; R. S. Yarullin; A. A. Pimerzin; P. A. Nikul’shin
      Pages: 31 - 38
      Abstract: Results from studying the supercritical fluid СО2-extraction regeneration of DN-3531 industrial nickel–molybdenum hydrotreatment catalyst in the temperature range of 323.15–383.15 K, at pressures of up to 30 MPa, and with modification of the basic extragent with such polar compounds as chloroform, methanol, ethanol, acetone, and dimethylsulfoxide (DMSO), are presented. The order of modifiers corresponds to the increase in the solubilizing ability of modified supercritical carbon dioxide (SC-СО2) with respect to catalyst- deactivating deposits. With DMSO as the most efficient modifier, however, not only are deactivating compounds removed but nickel and molybdenum as well, considerably reducing the final activity of a regenerated sample. During extraction regeneration, the content of coke in the catalyst is reduced by two-thirds, while the specific surface area and the pore volume grow. The activity of the deactivated catalyst in dibenzothiophene hydrodesulfurization (HDS) and naphthalene hydrogenation grows by several hundred per cent after one-time SC-CO2 treatment and is 2.5 times higher than for a sample regenerated using the traditional oxidative method.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010020
      Issue No: Vol. 9, No. 1 (2017)
  • A microfiber catalyst with lemniscate structural elements
    • Authors: S. A. Lopatin; P. E. Mikenin; D. A. Pisarev; S. V. Zazhigalov; D. V. Baranov; A. N. Zagoruiko
      Pages: 39 - 47
      Abstract: A new type of catalyst based on microfiber supports with microfibers twined into looped threads (lemniscate) that in turn form a structured flexible stable and geometrically regular bulk bed permeable to a reaction flow and not requiring any additional structurial elements is described. Deep toluene oxidation experiments show that the proposed platinum lemniscate glass-fiber catalyst (LGFC) considerably surpasses (by 8–10 times and more) familiar geometric types of catalysts, microfiber and otherwise, in both the specific observed activity per unit active component mass and the ratio between the observed activity and the specific hydraulic resistance. The reason for its superiority is a uniquely high efficiency of mass transfer in the external diffusion region of reactions. Among the promising fields of application for the proposed systems are fast gasphase catalytic reactions, liquid-phase catalytic reactions, and complicated reaction processes, in which the selectivity and the yield of target products are sensitive to diffusion inhibition.
      PubDate: 2017-01-01
      DOI: 10.1134/s207005041701010x
      Issue No: Vol. 9, No. 1 (2017)
  • Pt/BEA–Al 2 O 3 catalysts for the isomerization of benzene/heptane
           mixtures. I: Optimizing the support’s composition
    • Authors: E. A. Belopukhov; I. M. Kalashnikov; M. D. Smolikov; D. I. Kir’yanov; T. I. Gulyaeva; A. S. Belyi
      Pages: 48 - 53
      Abstract: Pt/BEA–Al2O3 catalysts for the hydroisomerization of benzene-containing gasoline fractions are studied using a model feedstock (20% benzene and 80% n-heptane). The catalysts are prepared by varying the zeolite content from 5 to 70 wt % at a constant Pt loading of 0.3 wt % in all samples, with an aqueous H2PtCl6 solution being used as the Pt precursor. The acid properties of the samples are studied by means of temperature-programmed desorption (TPD). The effect of the support’s zeolite/binder ratio on the activity of the catalysts is determined: an increase in the zeolite content raises the system’s acidity and shifts the range of the reaction toward lower temperatures. The optimum zeolite/binder ratio is found to be 30% BEA/70% Al2O3. Changing the SiO2/Al2O3 ratio of the zeolite from 25 to 40 is shown to have no noticeable effect on catalyst activity. The use of the catalysts supported on 30% BEA/70% Al2O3 in the hydroisomerization of benzenecontaining gasoline fractions can be recommended for improving environmental performance.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010032
      Issue No: Vol. 9, No. 1 (2017)
  • Preparing and studying Pt/WO 3 /ZrO 2 catalysts for the isomerization of n
    • Authors: M. D. Smolikov; V. A. Shkurenok; S. S. Yablokova; D. I. Kir’yanov; E. A. Paukshtis; N. N. Leont’eva; A. S. Belyi; V. A. Drozdov
      Pages: 54 - 61
      Abstract: The effect of the temperature of WO3/ZrO2 support calcination in the range of 700–1000°C on the phase composition, acid, and catalytic properties of Pt/WO3/ZrO2 catalysts is studied. Using ammonia TPD, it is found that calcination in the temperature range of 850–950°C results in the formation of strong acid sites that increase the yield of the target products of the reaction of n-heptane isomerization: high octane di- and trimethylsubstituted isomers. DRIFT is used to determine the role of catalyst calcination in an air flow plays in the formation of charged platinum atoms, which results in higher catalyst activity.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010135
      Issue No: Vol. 9, No. 1 (2017)
  • Enzymatic interesterification of sunflower oil and hydrogenated soybean
           oil with the immobilized bacterial recombinant lipase from Geobacillus
           stearothermophilus G3
    • Authors: Y. V. Samoylova; A. V. Piligaev; K. N. Sorokina; V. N. Parmon
      Pages: 62 - 70
      Abstract: In this study we discuss the properties of biocatalyst based on Geobacillus stearothermophilus G3 lipase immobilized on silica gel. Interesterification of sunflower oil and hydrogenated soybean oil (HSO) in a batch reaction was completed within 2 h, 10% biocatalyst (wt %), 70°С, and HSO: sunflower oil molar ratio of 1: 3. The physical and chemical parameters of reaction products were studied by HPLC-MS to access the composition of triacylglycerides and by slip melting point method. Biocatalyst has shown high operational stability. The estimated time of its operation in the oil mixture was 243 h that makes this catalyst promising for application in manufacturing of modified fats, including fats with high melting temperatures.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010123
      Issue No: Vol. 9, No. 1 (2017)
  • Improving the efficiency of the bioconversion of plant raw materials with
           mutant cellulases of Penicillium verruculosum
    • Authors: A. S. Dotsenko; A. M. Rozhkova; A. V. Gusakov; A. P. Sinitsyn
      Pages: 71 - 76
      Abstract: Plant biomass is the main type of organic material on Earth. The efficiency of biocatalytic conversion of plant raw materials determines the cost of their biotechnological processing to produce commercially valuable products such as organic alcohols and acids, carbohydrates, and hydrocarbons. New recombinant Penicillium canescens strains that produce not only their own enzyme complex but also heterologous cellulases (i.e., mutant and wild-type cellobiohydrolase I (CBH I) and endoglucanase II (EG II) of P. verruculosum) are constructed. Enzymatic agents (EAs) prepared on the basis of recombinant strains of P. canescens are found to be more active in the hydrolysis of crushed aspen wood. Yields of glucose and reducing sugars are observed 24–72 h after hydrolysis with EAs prepared in recombinant strains to be from 48 to 52 and 60 to 64%, respectively, higher than those for hydrolysis with EAs prepared in the initial recipient strain. The presence of N45A and N194A site-specific mutations introduced to reduce surface glycosilation thus results in a substantial increase in the yields of desired CBH I and EG II.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010044
      Issue No: Vol. 9, No. 1 (2017)
  • Effect of the milling of wheat bran on its properties and reactivity
           during biocatalytic conversion
    • Authors: D. O. Osipov; A. G. Bulakhov; O. G. Korotkova; A. M. Rozhkova; E. O. Duplyakin; A. V. Afonin; A. S. Sereda; A. P. Sinitsyn
      Pages: 77 - 84
      Abstract: The possibility of using wheat bran as a feedstock for sugar production via biocatalytic conversion is demonstrated. The relatively low reactivity of this feedstock can be doubled or quadrupled by dry milling on an AGO-2S planetary mill activator. The maximum yield of reducing sugars, 68.6 g/L (initial substrate concentration, 100 g/L; glucose is the major component of the resulting sugars, 93–95%), is achieved when wheat bran milled for 7–10 min is subjected to bicatalytic conversion using the complex enzyme preparation (EP) of Penicillium verruculosum gaBG with cellulolytic, hemicellulolytic, and amylolytic activity at a gaBG dose of 60 mg/g (supplemented with F10 β-glucosidase EP, 40 units/g). Polysaccharides comprise 62.4% of the dry weight of the wheat bran; allowing for the water incorporated during enzymatic hydrolysis, the achieved yield is close to the theoretical figure (68.6 g/L) and there is virtually complete conversion of the wheat bran carbohydrates. Lengthening the duration of milling to 7–10 min considerably reduces the size of bran particles, lowers (by 28%) their ability to bind water, nearly doubles the content of water-soluble sugar, and increases (by 12.6%) the total content of soluble components, relative to the initial material.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010111
      Issue No: Vol. 9, No. 1 (2017)
  • Enzymatic synthesis of butyrates of fusel oil
    • Authors: V. S. Gamayurova; K. L. Shnaider; M. J. Jamai
      Pages: 85 - 90
      Abstract: Many esters derived from lower aliphatic acids and alcohols have pleasant fruity aromas. These compounds are common in the plant kingdom. Some are chemically synthesized and used as fragrances. In this work, fruity flavored butyric esters are produced using lipase agents. The substrate is an alcohol-containing fraction obtained by distilling fusel oil, a waste product of the alcohol industry (T b = 120–140°С). The yield of the target products in the presence of pancreatic lipase and the lipase from the Candida rugosa yeast is ~94.0% under the determined optimum conditions.
      PubDate: 2017-01-01
      DOI: 10.1134/s2070050417010068
      Issue No: Vol. 9, No. 1 (2017)
  • Nontemplate sol–gel synthesis of catalytically active mesoporous
    • Authors: R. U. Kharrasov; M. R. Agliullin; R. R. Talipova; A. D. Badikova; B. I. Kutepov
      Pages: 287 - 292
      Abstract: A method for the nontemplate sol–gel synthesis of micro-mesoporous and mesoporous titanosilicates is developed using commercially available raw materials (a mixture of oligomer esters of orthosilicic acid (Ethylsilicate-40) and a water–alcohol solution of titanium(IV) ethoxide). The effect of the pH values of the reaction mixture on sol–gel synthesis is studied using the characteristics of the porous structure of titanosilicates. Samples of amorphous structure with different textural characteristics are obtained by varying the pH in the range of 3–10: specific surface area, 320–740 m2/g; micropore volume, 0.04–0.15 cm3/g; and mesopore volume, 0–0.92 cm3/g. It is shown that a sample of mesoporous titanosilicate obtained with alternating pH values has maximum catalytic activity in the oxidation reaction of 4-tert-butylphenol (TBP) in aqueous solutions of hydrogen peroxide. (Conversion of 4-tert-butylphenol, 45 wt %; selectivity of the formation of 4-tert-butylcatechol, 66 wt %. Conditions: 10 wt % of titanosilicate; TBP/H2O2 = 1/2; 75°C; 1 h).
      PubDate: 2016-10-01
      DOI: 10.1134/s207005041604005x
      Issue No: Vol. 8, No. 4 (2016)
  • Dehydrogenation of methanol over copper-containing catalysts
    • Authors: T. P. Minyukova; A. V. Khasin; A. A. Khassin; N. V. Shtertser; I. I. Simentsova; T. M. Yurieva
      Pages: 293 - 299
      Abstract: A comparative study of copper-containing catalysts with different chemical and phase compositions is performed to determine conditions for the implementation of the vapor phase and highly selective dehydrogenation of methanol to methyl formate or syngas. A thermodynamic analysis of the reaction is also performed. It is shown that Cu0 nanoparticles formed in the course of reductive activation reveal different selectivities with respect to the formation of methyl formate from methanol or its dehydrogenation with formation of syngas. By correctly selecting the catalyst composition and process conditions, high (90–100%) selectivity with respect to either methyl formate or syngas can be attained. Catalysts based on Cu–Zn hydrosilicate of the zincsilite type and on CuAlZn aurichalcite are highly selective in the process of methyl formate formation. An estimation based on experimental data shows that the productivity of Cu/SiO2 catalyst, the one most effective in dehydrogenation to syngas, is as high as 20 m3/h of syngas at a methanol vapor pressure of 1 atm, a temperature of 200°C, and a contact time of 0.5 s.
      PubDate: 2016-10-01
      DOI: 10.1134/s2070050416040073
      Issue No: Vol. 8, No. 4 (2016)
  • A new method for producing substituted anthraquinones via diene synthesis
    • Authors: L. L. Gogin; E. G. Zhizhina; Z. P. Pai
      Pages: 310 - 315
      Abstract: The possibilities of developing catalytic processes for the synthesis of 2-methylanthraquinone from 1,4-naphthaquinone (NQ) and isoprene, and synthesizing 2,3-dimethylanthraquinone from NQ and 2,3-dimethylbutadiene in the presence of aqueous solutions of high-vanadium heteropoly acid (HPA) as a bifunctional catalyst are examined. Two methods for catalyst regeneration are discussed: oxidation with oxygen at \({P_{o{}_2}}\) = 0.3–0.4 MPa and with concentrated nitric acid at atmosphere pressure. It is shown that regeneration with nitric acid ensures deeper oxidation of the reduced catalyst. Complete restoration of the properties of the catalyst following regeneration offers the possibility of its repeated use in the processes discussed in this work.
      PubDate: 2016-10-01
      DOI: 10.1134/s2070050416040048
      Issue No: Vol. 8, No. 4 (2016)
  • Investigating the process of heavy crude oil steam cracking in the
           presence of dispersed catalysts. II: Investigating the effect of
           Ni-containing catalyst concentration on the yield and properties of
    • Authors: P. M. Eletskii; O. O. Mironenko; G. A. Sosnin; O. A. Bulavchenko; O. A. Stonkus; V. A. Yakovlev
      Pages: 328 - 335
      Abstract: The process of heavy crude oil (HCO) steam cracking under a batch regime at 425°C in the presence of Ni-containing nanodispersed catalyst (0.3–2.0 wt % with respect to Ni) is investigated. It is established that using this catalyst facilitates the upgrading of semi-synthetic oil produced from HCO: the Н: С ratio rises (in comparison to steam cracking with no catalyst), and the sulfur content and viscosity are reduced. The Н: С ratio in the liquid products grows slightly along with the catalyst content, but the yield of liquid products falls from 81 to 76% during the process with a simultaneous increase in the yield of coke and gaseous products (from 8 to 13 and from 2 to 4 wt %, respectively). Catalyst with coke residue is investigated by means of XRD and TEM. It is shown that nanosized particles of the Ni9S8 phase with sizes of 15–40 nm form from the catalyst precursor (Ni(NO3)2 · 6H2O) under the process conditions. The selection and investigation of catalytic systems for heavy crude oil cracking in the presence of superheated steam, along with optimization of the process conditions, are required to further enhance the efficiency of the upgrading process.
      PubDate: 2016-10-01
      DOI: 10.1134/s2070050416040036
      Issue No: Vol. 8, No. 4 (2016)
  • Stability of catalysts for the oxidative chlorination of methane
    • Authors: V. N. Rozanov; Yu. A. Treger; I. S. Silina
      Pages: 336 - 340
      Abstract: The effects on the stability of catalysts for the oxidative chlorination of methane due to evaporation of the active component (copper chloride) of the catalyst are studied. The volatility of copper chloride is shown to depend mainly on the catalyst composition and temperature. At a moderate 350°C in the reactor, the evaporation of copper chlorides after 5 h is 0.45% on a catalyst containing copper and potassium chloride and 0.72% on a catalyst containing lanthanum chloride. The stability of catalyst operation can be effectively maintained not only by decreasing the volatility of copper chloride, but also by feeding hydrochloric acid with dissolved copper chloride isolated from the reaction gas of methane oxychlorination at the outlet of the reactor (for the removal of reaction heat and the recycling of unconverted hydrogen chloride) back into the reactor.
      PubDate: 2016-10-01
      DOI: 10.1134/s2070050416040085
      Issue No: Vol. 8, No. 4 (2016)
  • Methanation of the carbon supports of ruthenium ammonia synthesis
           catalysts: A review
    • Authors: P. G. Tsyrul’nikov; K. N. Iost; N. B. Shitova; V. L. Temerev
      Pages: 341 - 347
      Abstract: The propensity of carbon support for methanation in a hydrogen-containing medium is a problem for active ruthenium ammonia synthesis catalysts, since this leads to the degradation of the support and the sintering of the active component. This review analyses some key works on approaches to methanation inhibition and their results to show that, on the whole, an algorithm for solving the methanation problem has been found, i.e., the graphitization of carbon supports at high temperatures (up to 2000°C) and the introduction of ruthenium promoters, specifically alkali (Cs, K) and alkali-earth (Ba) oxides, whose role is to modify the electron state of ruthenium and block the surface of a carbon support to prevent it from interacting with active hydrogen. The most efficient catalyst not liable to methanation up to 700°C and a hydrogen pressure of 100 atm has been found. The resulting analysis can be useful in selecting and preparing Me/C catalysts in which Me represents metals of the VIII Group and others.
      PubDate: 2016-10-01
      DOI: 10.1134/s2070050416040115
      Issue No: Vol. 8, No. 4 (2016)
  • Mechanically activated enzymatic hydrolysis of yeast biomass
    • Authors: A. L. Bychkov; E. I. Ryabchikova; K. G. Korolev; T. F. Lomovskaya; O. I. Lomovskii
      Pages: 354 - 360
      Abstract: Experimental data obtained in studying processes that occur during the mechanoenzymatic hydrolysis of cell wall polymers of Saccharomyces cerevisiae yeast are presented. Special emphasis is placed on studying the reactivity of polymers contained in the supramolecular structure of cell walls, and on scaling the technology using pilot and industrial equipment. It is shown that mechanical treatment of yeast biomass allows us to alter the supramolecular structure of cell wall polymers and increase their reactivity in the enzymatic hydrolysis. Mechanical treatment disintegrates yeast cells and changes the supramolecular structure of polymers in their cell walls; the structural layers of a cell wall become disordered and diffused. A phenomenological model of mechanically activated enzymatic hydrolysis is proposed; the model is based on an autolocalization mechanism of the process. The domestic commercially available enzyme preparation CelloLux 2000 (OOO PA Sibbiopharm, Berdsk, Novosibirsk oblast) is used in this work. It is shown that changes in the supramolecular structure of yeast cell wall polymers occur during mechanically activated enzymatic hydrolysis. The yields of mannanoligosaccharides (1.1%) and mannanoproteins (2.7%) in the main extract are determined. Using pilot and industrial equipment at OOO PA Sibbiopharm, the technology is scaled and the production of a new mannanoligosaccharide product for animal husbandry is established. The pilot batch of the final product is effective against salmonellosis and is shown to increase the weight gain of experimental animals.
      PubDate: 2016-10-01
      DOI: 10.1134/s2070050416040024
      Issue No: Vol. 8, No. 4 (2016)
  • Erratum to: “Hydrocracking of Vegetable Oil on Boron-Containing
           Catalysts: Effect of the Nature and Content of a Hydrogenation
    • Authors: Yu. A. Chumachenko; A. V. Lavrenov; E. A. Buluchevskii; A. B. Arbuzov; T. I. Gulyaeva; V. A. Drozdov
      Pages: 361 - 361
      PubDate: 2016-10-01
      DOI: 10.1134/s2070050416040127
      Issue No: Vol. 8, No. 4 (2016)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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