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101.
Evgeniya Frantsina Nataliya Belinskaya Emiliya Ivanchina 《Korean Journal of Chemical Engineering》2018,35(2):337-347
The dehydrogenation and dewaxing of hydrocarbons of middle-distillate fractions, which proceed in the hydrogen medium, are of great importance in the petrochemical and oil refining industries. They increase oil refining depth and allow producing gasoline, kerosene, and diesel fractions used in the production of hydrocarbon fuels, polymer materials, synthetic detergents, rubbers, etc. Herewith, in the process of dehydrogenation of hydrocarbons of middle distillate fractions (C9–C14) hydrogen is formed in the reactions between hydrocarbons, and the excess of hydrogen slows the target reaction of olefin formation and causes the shift of thermodynamic equilibrium to the initial substances. Meanwhile, in the process of hydrodewaxing of hydrocarbons of middle distillate fractions (C5–C27), conversely, hydrogen is a required reagent in the target reaction of hydrocracking of long-chain paraffins, which ensures required feedstock conversion for production of low-freezing diesel fuels. Therefore, in this study we suggest the approach of intensification of the processes of dehydrogenation and dewaxing of middle distillate fractions by means of redistribution of hydrogen between the two units on the base of the influence of hydrogen on the hydrocarbon transformations using mathematical models. In this study we found that with increasing the temperature from 470 °C to 490 °C and decreasing the hydrogen/feedstock molar ratio in the range of 8.5/1.0 to 6.0/1.0 in the dehydrogenation reactor, the production of olefins increased by 1.45–1.55%wt, which makes it possible to reduce hydrogen consumption by 25,000 Nm3/h. Involvement of this additionally available hydrogen in the amount from 10,000 to 50,000 Nm3/h in the dewaxing reactor allows increasing the depth of hydrocracking of long-chain paraffins of middle distillate fractions, and, consequently improving low-temperature properties of produced diesel fraction. In such a way cloud temperature and freezing temperature of produced diesel fraction decrease by 1–4 °C and 10–25 °C (at the temperature of 300 °C and 340 °C respectively). However, when the molar ratio hydrogen/hydrocarbons decreases from 8.5/1.0 to 6.0/1.0 the yield of side products in the dehydrogenation reactor increases: the yield of diolefins increases by 0.1–0.15%wt, the yield of coke increases by 0.07–0.18%wt depending on the feedstock composition, which is due to decrease in the content of hydrogen, which hydrogenates intermediate products of condensation (the coke of amorphous structure). This effect can be compensated by additional water supply in the dehydrogenation reactor, which oxidizes the intermediate products of condensation, preventing catalyst deactivation by coke. The calculations with the use of the model showed that at the supply of water by increasing portions simultaneously with temperature rise, the content of coke on the catalyst by the end of the production cycle comprises 1.25–1.56%wt depending on the feedstock composition, which is by 0.3–0.6%wt lower that in the regime without water supply. 相似文献
102.
Structure and conductivity of yttria and scandia‐doped zirconia crystals grown by skull melting 下载免费PDF全文
Mihail A. Borik Sergey I. Bredikhin Vladimir T. Bublik Aleksej V. Kulebyakin Irina E. Kuritsyna Elena E. Lomonova Philipp O. Milovich Valentina A. Myzina Vyacheslav V. Osiko Polina A. Ryabochkina Nataliya Y. Tabachkova 《Journal of the American Ceramic Society》2017,100(12):5536-5547
In this paper a detailed study of the (ZrO2)1‐x(Y2O3)x (x=0.025–0.15), (ZrO2)1‐x(Sc2O3)x (x = 0.06 – 0.11) and (ZrO2)1‐x‐y(Sc2O3)x(Y2O3)y (x=0.07 – 0.11; y=0.01 – 0.04) solid solution crystals grown by skull melting technique is presented. The structure, phase composition, and ion conductivity of the obtained crystals were investigated by X‐ray diffraction, transmission electron microscopy, Raman scattering spectroscopy, and impedance spectroscopy. Maximum conductivity as (ZrO2)1‐x(Y2O3)x and (ZrO2)1‐x(Sc2O3)x solid solution crystals is observed for the compositions containing 10 mol% stabilizing oxide, and the conductivity of 10ScSZ is ~3 times higher than for 10YSZ. Experiments on crystal growth (ZrO2)1‐x‐y(Sc2O3)x(Y2O3)y solid solutions showed that uniform, transparent crystals 7Sc3YSZ, 7Sc4YSZ, 8Sc2YSZ, 8Sc3YSZ, 9Sc2YSZ, 9Sc3YSZ, 10Sc1YSZ, and 10Sc2YSZ are single phase crystal containing t″ phase. It is established that a necessary condition of melt growth of (ZrO2)1‐x‐y(Sc2O3)x(Y2O3)y single‐phase crystals is the total concentration of the stabilizing oxides from 10 to 12 mol%. The addition of Y2O3 affects the (ZrO2)1‐x‐y(Sc2O3)x(Y2O3)y solid solution conductivity different ways and depends on the Sc2O3 content in the starting composition. The effects of structure, phase composition, concentration, and type of stabilizing oxides on the electrical characteristics of obtained crystals are discussed. 相似文献
103.
Alexander V. Martynov Nataliya A. Makhaeva Lyudmila I. Larina 《Journal of Sulfur Chemistry》2017,38(5):510-518
An efficient method for preparation of earlier unknown S-oxide of 2(E),6(E)-bis(chloromethylidene)-4-thiomorpholinamine by oxidation of 2(E),6(E)-bis(chloromethylidene)-4-thiomorpholinamine hydrochloride with hydrogen peroxide in H2O or EtOH/H2O followed by the reaction mixture neutralization with Na2CO3 has been described. Interaction of the S-oxide with acetaldehyde, butanal, benzaldehyde, 4-methoxybenzaldehyde and 4-pyridinecarboxaldehyde in EtOH, C6H6, in the mixture of acetonitrile and ethanol or ethanol and benzene affords the unknown hydrazones, N-organylmethylidene-2(E),6(E)-bis(chloromethylidene)-4-thiomorpholinamine-1-oxides. 相似文献
104.
M. G. Astashev M. A. Novikov D. I. Panfilov P. A. Rashitov T. V. Remizevich M. I. Fedorova 《Thermal Engineering》2016,63(13):932-937
The article contains the analysis of the influence of the phase shifter (PS) on the energy processes in the power transmission line in terms of the two-unit model of the electric network. The approach to synthesis of the models regulated by the phase shifter providing for both calculation of the steady operation modes of the electric networks with the phase shifters and research of the electromagnetic processes and designing of the device itself is offered. 相似文献
105.
Rodríguez E Simoes RV Roig A Molins E Nedelko N Slawska-Waniewska A Aime S Arús C Cabañas ME Sanfeliu C Cerdán S García-Martín ML 《Magma (New York, N.Y.)》2007,20(1):27-37
A new iron-based T 1 contrast agent consisting of a complex of iron ions coordinated to phosphate and amine ligands (Fe(phos) in short) has been characterized by spectroscopic and magnetic measurements. NMR relaxation studies showed r 1 values to be dependent on the phosphate salt concentration, K2HPO4, present in the medium. r 1 reaches a maximum value of 2.5 mM?1 s?1 for measurements carried out at 7 T and 298 K. 31P MRS, Mössbauer spectroscopy and magnetic measurements of Fe(phos) solutions suggest paramagnetic Fe3+ ions present in the studied iron–phosphate complex. In vitro and in vivo toxicity experiments with C6 cells and CD1 mice, respectively, demonstrated lack of toxicity for Fe(phos) at the highest dose tested in the MRI experiments (12 mM iron for C6 cells and 0.32 mmol iron/kg for mice). Finally, T 1 weighted images of brain tumours in mice have shown positive contrast enhancement of Fe(phos) for tumour afflicted regions in the brain. 相似文献
106.
Knop M Pacyna S Voloshchuk N Kant S Müllenborn C Steiner U Kirchmair M Scherer HW Schulz M 《Journal of chemical ecology》2007,33(2):225-237
Benzoxazolinone detoxification is similar in plants grown under sulfur deficiency conditions and in control plants grown with
an optimal S supply. However, when S-deficient plants were treated with metolachlor before benzoxazolin-2(3H)-one (BOA) incubation,
detoxification was reduced, as indicated by a lower accumulation of the detoxification products BOA-6-O-glucoside and glucoside carbamate and by a loss of BOA-6-OH glucosyltransfease activity. Root colonizing microorganisms and
the endophytic fungus Fusarium verticillioides participated in benzoxazolinone detoxification by converting the compound to 2-acetamidophenol (AAP) or O-hydroxyphenyl malonamic acid (OHPMA), a process accompanied by the appearance of phenoxazinone. Maize roots, however, absorbed
AAP and OHPMA only in traces. Absorbed traces of OHPMA stimulated maize radicle growth, and traces of AAP stimulated cress.
Phenoxazinone inhibited the growth of cress radicles at concentrations higher than 500 μM, whereas maize radicles were hardly
affected. F. verticillioides did not convert benzoxazolinone to any known microbial degradation product when the medium of maize seedlings was inoculated
with the fungus under sterile condition. Plant–fungus interactions seem to be important in plant survival of allelopathic
attacks. This study points to a complicated network of allelopathic interactions that are influenced by biotic and abiotic
factors, including herbicides. 相似文献
107.
Igor Bychkov Galina Baydakova Alexandra Filatova Ochir Migiaev Andrey Marakhonov Nataliya Pechatnikova Ekaterina Pomerantseva Fedor Konovalov Maria Ampleeva Vladimir Kaimonov Mikhail Skoblov Ekaterina Zakharova 《International journal of molecular sciences》2021,22(19)
Pompe disease (OMIM#232300) is an autosomal recessive lysosomal storage disorder caused by mutations in the GAA gene. According to public mutation databases, more than 679 pathogenic variants have been described in GAA, none of which are associated with mobile genetic elements. In this article, we report a novel molecular genetic cause of Pompe disease, which could be hardly detected using routine molecular genetic analysis. Whole genome sequencing followed by comprehensive functional analysis allowed us to discover and characterize a complex mobile genetic element insertion deep in the intron 15 of the GAA gene in a patient with infantile onset Pompe disease. 相似文献
108.
Iryna Govbakh Vitalii Kyryk Alina Ustymenko Volodymyr Rubtsov Oleg Tsupykov Nataliya V. Bulgakova Danylo O. Zavodovskiy Inna Sokolowska Andriy Maznychenko 《International journal of molecular sciences》2021,22(21)
Impaired motor and sensory functions are the main features of Charcot–Marie–Tooth disease. Mesenchymal stem cell (MSCs) therapy is one of the possible treatments for this disease. It was assumed that MSCs therapy can improve the contractile properties of the triceps surae (TS) muscles in mice with hereditary peripheral neuropathy. Murine adipose-derived mesenchymal stromal cells (AD-MSCs) were obtained for transplantation into TS muscles of FVB-C-Tg(GFPU)5Nagy/J mice. Three months after AD-MSCs transplantation, animals were subjected to electrophysiological investigations. Parameters of TS muscle tension after intermittent high frequency electrical sciatic nerve stimulations were analyzed. It was found that force of TS muscle tension contraction in animals after AD-MSCs treatment was two-time higher than in untreated mice. Normalized values of force muscle contraction in different phases of electrical stimulation were 0.3 ± 0.01 vs. 0.18 ± 0.01 and 0.26 ± 0.03 vs. 0.13 ± 0.03 for treated and untreated animals, respectively. It is assumed that the two-fold increase in TS muscle strength was caused by stem cell therapy. Apparently, AD-MSCs therapy can promote nerve regeneration and partial restoration of muscle function, and thus can be a potential therapeutic agent for the treatment of peripheral neuropathies. 相似文献
109.
Kirillova I. A. Tarasova L. S. Fedorova E. N. Gusev A. O. Simakov D. A. Nagibin G. E. 《Protection of Metals and Physical Chemistry of Surfaces》2020,56(4):849-856
Protection of Metals and Physical Chemistry of Surfaces - The resistance of different TiB2 powders to oxidative degradation is studied by synchronous thermal analysis. The temperature dependence of... 相似文献
110.
Vignolini S Yufa NA Cunha PS Guldin S Rushkin I Stefik M Hur K Wiesner U Baumberg JJ Steiner U 《Advanced materials (Deerfield Beach, Fla.)》2012,24(10):OP23-OP27
Optical metamaterials have unusual optical characteristics that arise from their periodic nanostructure. Their manufacture requires the assembly of 3D architectures with structure control on the 10-nm length scale. Such a 3D optical metamaterial, based on the replication of a self-assembled block copolymer into gold, is demonstrated. The resulting gold replica has a feature size that is two orders of magnitude smaller than the wavelength of visible light. Its optical signature reveals an archetypal Pendry wire metamaterial with linear and circular dichroism. 相似文献