Key words: subcritical water, onion husk, bioflavоnoids, quercetin, quercetin glycosides, isorhamnetin glycosides
New method for extraction of bioflavonoids from onion husk using subcritical water was developed. The method is environmentally friendly and more effective than traditional extraction methods using of the expensive and toxic organic solvents.
To determine the quantitative and qualitative composition of obtained extracts was used high-performance liquid chromatography combined with mass-spectrometry.
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7.0.100-2018
Extraction of the bioflavonoid mixture from onion husk by subcritical water / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2012. – Т. 7. – № 4. – С. 4-15. - DOI:
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Izvlechenie bioflavonoidov iz sheluhi luka v srede subkriticheskoj vody / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2012. – Т. 7. – № 4. – S. 4-15. - DOI:
En
Extraction of the bioflavonoid mixture from onion husk by subcritical water. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 4, 4-15 (2012). https://doi.org/
Key words: bitumen, supercritical water, hydrogenation, desulphurization, ZnO nanoparticles
The composition of liquid and volatile products and residue of bitumen conversion in supercritical water (SCW) flow at 400 °C and 30 MPa with and without addition of zinc shavings to bitumen is investigated. The yield of liquid products at bitumen SCW conversion reaches 47.3 %. The data on oxygen and hydrogen balance in the initial bitumen, products, and conversion residue indicate the chemical participation of Н2О molecules in the conversion. The yield of liquid products is increased up to 62.3 % if zinc is added to the initial bitumen at simultaneous increase of Н/С atomic ratio in the products. Hydrogenation is due to a hydrogen evolution during zinc oxidation by supercritical water. Under these conditions ZnO nanoparticles of 50—100 nm size are formed. The data of transmission electronic microscopy and X-ray diffraction analysis of oxidized zinc demonstrate the presence of about 0.5 % wt. of ZnS and about 1.2 % wt. of metal zinc clusters (up to 10 nm size) in the samples. According to the sulfur atoms balance accounting products and conversion residue, 12.6 % wt. of bitumen sulfur participates in the formation of zinc sulfide.
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7.0.100-2018
Hydrogenation of bitumen in supercritical water flow and effect of zinc addition / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2012. – Т. 7. – № 4. – С. 16-28. - DOI:
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Gidrirovanie bituma v potoke sverhkriticheskoj vody i vliyanie dobavok cinka / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2012. – Т. 7. – № 4. – S. 16-28. - DOI:
En
Hydrogenation of bitumen in supercritical water flow and effect of zinc addition. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 4, 16-28 (2012). https://doi.org/
Key words: spectral analysis, hydrogen bond, fluids
The results of the investigation of isobaric heating effect on H-bonds distribution in H2O—D2O system on the basis of comparative analysis of ν(OD) and 2ν3(H2O) spectral bands are presented. In the case of analysis of spectral band assigned to the 2ν3(H2O) overtone a more detailed information on the effect of external perturbation on the structure formation can be obtained. In particular, appreciable dissimilarities in the quality of obtained data for the ν(OD) and 2ν3(H2O) bands are noticed. In the case of their low frequency regions which are determined by the presence of strong H-bonds such differences are more evident.
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7.0.100-2018
A comparative study of ν(OD) and 2ν3(H2O) spectral bands in H2O—D2O system at isobaric heating / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2012. – Т. 7. – № 4. – С. 29-51. - DOI:
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Sravnitel'nyj analiz spektral'nyh polos n(OD) i n3(H2O) sistemy H2O—D2O v usloviyah izobaricheskogo nagreva / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2012. – Т. 7. – № 4. – S. 29-51. - DOI:
En
A comparative study of ν(OD) and 2ν3(H2O) spectral bands in H2O—D2O system at isobaric heating. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 4, 29-51 (2012). https://doi.org/
Key words: 1,1-dimethylhydrazine, peat, supercritical fluid extraction
A supercritical fluid extraction of highly toxic rocket fuel component (1,1-dime- thylhydrazine, UDMH) from peaty soils with carbon dioxide is proposed as an express method of sample preparation for ion chromatographic analysis. Optimal conditions of extraction are determined. The efficiency of the UDMH extraction can be improved by basic treatments of the soil sample and by the use of proper additives to SC CO2 (co-solvents).
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7.0.100-2018
Supercritical fluid extraction of 1,1- dimethylhydrazine from peaty soils. / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2012. – Т. 7. – № 4. – С. 52-58. - DOI:
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Sverhkriticheskaya flyuidnaya ekstrakciya 1,1-dimetilgidrazina iz torfyanyh pochv / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2012. – Т. 7. – № 4. – S. 52-58. - DOI:
En
Supercritical fluid extraction of 1,1- dimethylhydrazine from peaty soils.. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 4, 52-58 (2012). https://doi.org/
Key words: supercritical fluid extraction, hyperforin, Hypericum perforatum, biotesting, bacteria, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, yeast, Candida albicans, sea urchin, embryo, infusorian
Biological activity of supercritical fluid (SCF) extract from St. John’s wort, as well as solution of hyperforin isolated from these extracts with respect to both procaryotic (standard bacteria strains) and eucaryotic (yeast and sea urchin gamets and zygotes) cells is tested. A pronounced toxicity of hyperforin solution with respect to blue pus bacillus Pseudomonas aeruginosa is observed. Antimicrobic activity of the same solution with respect to other tested bacteria and yeast is not revealed. Also toxicity of both hyperforin solution and total St. John’s wort SF extract on sperm cell and zygotes of sea urchin is registered. The addition of SCF extract to the culture of growing embryos does not affect fertilization and division, but cell development terminates at an early gastrulastage . This indicates that the extract damages agenome transcription process in zygotes.
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7.0.100-2018
Effect of st. John’s wort supercritical extract and hyperforin solution on biological subjects / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2012. – Т. 7. – № 4. – С. 59-71. - DOI:
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Vliyanie sverhkriticheskogo ekstrakta zveroboya prodyryavlennogo hypericum perforatum i rastvora giperforina na biologicheskie ob"ekty / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2012. – Т. 7. – № 4. – S. 59-71. - DOI:
En
Effect of st. John’s wort supercritical extract and hyperforin solution on biological subjects. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 4, 59-71 (2012). https://doi.org/
Key words: supercritical fluid extraction, carbon dioxide, garlic, extract, synthetic analogs, biocides
As we recently demonstrated, some individual component of CO2 supercritical (SC) garlic extract and some synthetic disulfide analogs are active as antimicrobials. In the course of this investigation six compounds (diallyl disulfide, 1-propenylallyl disulfide, methylallyl disulfide, diallyl trisulfide, 2-vinyl-4H-1,3-dithiin and 3-vinyl-4H-1,2-dithiin) were isolated from SC garlic extract and identified. Also, two novel sulfoxide-containing garlic analogs were synthesized. All isolated and synthetic substances were tested as potential antimicrobials against gram-positive bacteria Bacillus cereus, Mycobacterium smegmatis and Micrococcus luteus, аnd gram-negative bacteria Pseudomonas aurantiaca. Diallyl disulfide and diallyl trisulfide demonstrated the best activity both against gram- positive and gram-negative bacteria.
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7.0.100-2018
Sulfur-containing components of supercritical garlic extracts and their synthetic analogs as potential biocides / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2012. – Т. 7. – № 4. – С. 72-81. - DOI:
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Serasoderzhashchie komponenty sverhkriticheskih ekstraktov chesnoka i ih sinteticheskie analogi kak potencial'nye biocidy / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2012. – Т. 7. – № 4. – S. 72-81. - DOI:
En
Sulfur-containing components of supercritical garlic extracts and their synthetic analogs as potential biocides. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 4, 72-81 (2012). https://doi.org/
Key words: supercritical fluids, cellulose, acetylation, cellulose diacetate, acetic anhydride, process parameters
The possibility of cellulose diacetate production by direct acetylation of sulphite pulp with acetic anhydride in supercritical carbon dioxide (SC CO2) is demonstrated. Optimal acetic anhydride to cellulose ratio and parameters of SC CO2 are chosen.
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7.0.100-2018
The influence of the supercritical carbon dioxide parameters on the cellulose acetylization and on the cellulose acetates qualities / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2012. – Т. 7. – № 4. – С. 82-87. - DOI:
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Vliyanie parametrov sverhkriticheskogo dioksida ugleroda na process acetilirovaniya cellyulozy i svojstva poluchaemyh acetatov / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2012. – Т. 7. – № 4. – S. 82-87. - DOI:
En
The influence of the supercritical carbon dioxide parameters on the cellulose acetylization and on the cellulose acetates qualities. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 4, 82-87 (2012). https://doi.org/
Key words: supercritical fluids, micronization, water-soluble salts
Supercritical fluid micronization of water-soluble salts with supercritical carbon dioxide targeted on to fabrication of submicron and nanosized particles is experimentally studied using NaCl and NH4NO as examples. A parabolic-type size distribution of resulting salt particles on CO2 pressure at 80 °C is determined. Minima of mass-average particle sizes (0.14 rm and 0.42 rm for NaCl and NH4NO respectively) are reached at CO2 pressures in the range of 7.5—10 MPa.
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7.0.100-2018
Supercritical fluid micronization of water-soluble salts / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2012. – Т. 7. – № 4. – С. 88-94. - DOI:
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Sverhkriticheskaya flyuidnaya mikronizaciya vodorastvorimyh solej / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2012. – Т. 7. – № 4. – S. 88-94. - DOI:
En
Supercritical fluid micronization of water-soluble salts. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 4, 88-94 (2012). https://doi.org/
Key words: supercritical fluid, water, carbon dioxide, tungsten trioxide, zirconium dioxide, syngas
Oxidation of bulk samples of tungsten (923 K) and zirconium (773 and 873 K) by supercritical fluid Н20/С02 (molar ratio [CO2]/[H2O] = 0.17—0.26) at about 300 atm is studied. The formation of monoclinic WO3, monoclinic W19O55, monoclinic ZrO2, gaseous H2, CO, CH4, as well as amorphous carbon (on the surface of tungsten oxide), is observed. Certain differences in oxidation of tungsten and zirconium are revealed. Oxidation of tungsten with CO2 starts only after oxide formation in reaction with H2O. Zirconium samples can be oxidized fully, whereas oxidation of tungsten terminates due to the formation of the protective oxide layer on metal surface.
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7.0.100-2018
Combustion gas synthesis at tungsten and zirconium interaction with supercritical fluid H2O/CO2 / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2012. – Т. 7. – № 4. – С. 95-103. - DOI:
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Obrazovanie goryuchih gazov pri vzaimodejstvii vol'frama i cirkoniya so sverhkriticheskim flyuidom H2O/CO2 / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2012. – Т. 7. – № 4. – S. 95-103. - DOI:
En
Combustion gas synthesis at tungsten and zirconium interaction with supercritical fluid H2O/CO2. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 4, 95-103 (2012). https://doi.org/