In situ study on the effects of Ni and Mo on the passive film formed on Fe–20Cr alloys by photoelectrochemical and Mott–Schottky techniques

Effects of alloying elements (Ni and Mo) on the structure of passive film formed on Fe–20Cr alloys in pH 8.5 buffer solution were explored by analyzing the in situ electronic properties measured using the photoelectrochemical technique and Mott–Schottky analysis. The passive film formed on Fe–20Cr–10Ni was found to be mainly composed of Cr-substituted γ-Fe₂O₃ from similarities in photocurrent response for the passive films formed on the alloy and Fe–20Cr. On the other hand, the photocurrent spectra for the passive films of Fe–20Cr–15Ni–(0, 4)Mo alloys exhibited the spectral components associated with NiO and Mo oxide (MoO₂ and/or MoO₃) in addition to that induced by Cr-substituted γ-Fe₂O₃. Mott–Schottky plots for the passive films formed on Fe–20Cr–(10, 15)Ni and Fe–20Cr–15Ni–4Mo confirmed that the passive films on Fe–20Cr–(10, 15)Ni–(0, 4)Mo alloys have a base structure of Cr-substituted γ-Fe₂O₃ with variation of densities of shallow and deep donors depending on the Ni and Mo contents in the alloys. We suggest that the passive film formed on Fe–20Cr–(10, 15)Ni and Fe–20Cr–15Ni–4Mo alloys are composed of (Cr, Ni, Mo)-substituted γ-Fe₂O₃ when the concentrations of Ni and Mo are below critical values. However, NiO and Mo oxide (MoO₂ and/or MoO₃) would be precipitated in the passive films when the concentrations of Ni and Mo exceed critical values.     

Radioisotope excited EDXRF analysis of sediment core samples from the southern part of the Black Sea +

In all 43 sediment samples were collected as gravity cores in depthfrom 70 to 150 cm, from the 20 sampling sites of the continental slope ofthe southern part of the Black Sea, during 1978. The samples were quantitativelyanalyzed by radioisotope excited energy dispersive X-ray fluorescence spectrometry(EDXRF) using fundamental parameter technique (FTP). The investigated sedimentsamples were the organic rich-mud components of the core samples, which wereknown as rich in metals. The metal concentration ranges were as follows: Ca(3.1–12.9%), Ti (1000–2000 µg/g), V (40–150 µg/g),Cr (30–200 µg/g), Mn (200–1500 µg/g), Ni (25–100µg/g), Cu (20–70 µg/g), Zn (20–50 µg/g), Br(15–670 µg/g), Rb (5–90 µg/g), Sr (80–700 µg/g),Y (10–20 µg/g), Mo (10–111 µg/g), Zr (20–190µg/g), Cd ( <1–5 µg/g), Sb ( <1–5 µg/g),I (10–430 µg/g), Ba (100–1650 µg/g), La (5–18µg/g), Ce (12–38 µg/g) and Nd (6–17 µg/g). Thesediment cores systematically collected in 1978 by Mineral Research and ExplorationInstitute of Turkey (MTA) are the oldest available sediment samples from theTurkish coastline of the Black Sea. Therefore, the results may be used asreferences for monitoring possible future metal pollution.     

Arcutin — A new type of diterpene alkaloids

The structure of the diterpene alkaloid arcutin, which is isolated fromAconitum arcuatum Maxim. (Ranunculaceae), is solved by x-ray methods. Arcutin represents a new type of diterpene alkaloids containing a C5–C20 bond instead of the traditional C10–C20 bond in the carbon backbone.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 62–65, January–February, 2000.     

Coulometric estimation of phenyl thiourea, thioglycollic acid and cysteine

Summary Controlled-potential coulometric estimations of phenyl thiourea, thioglycollic acid and cysteine have been carried out employing 1 N hydrochloric acid, Clark and Lubs buffer and phosphate buffer pH 6.2 as electrolytes, respectively. Quantities ranging from 11–34 mg, 5–20 mg and 5–20 mg have been estimated with average errors of ± 0.55 mg, ± 0.30 mg and ± 0.38 mg, respectively. The elimination of a background in the case of phenyl thiourea has been achieved by carrying out the oxidation at low temperature.

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Zusammenfassung Eine coulometrische Bestimmung von Phenylthioharnstoff, Thioglykolsäure und Cystein wurde bei kontrolliertem Potential unter Verwendung von 1 N Salzsäure, Puffer nach Clark und Lubs bzw. Phosphatpuffer pH 6,2 als Elektrolyten durchgeführt. Bei Probeeinwaagen von 11–34 mg, 5–20 mg bzw. 5–20 mg wurden mittlere Fehler von ± 0,55 mg, ± 0,30 mg bzw. ± 0,38 mg erhalten. Ein Untergrundstrom, der bei Phenylthioharnstoff auftrat, wurde durch Arbeiten bei niedriger Temperatur eliminiert.

     

Gasometric determination of nitrogen in organic substances Communication 3. New rapid method of determining nitrogen

Summary A new and rapid method has been developed for determining nitrogen in various organic substances. One determination takes 20–30 min. The accuracy of the method is ±0.1–0.2%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1561–1564, September, 1964     

Structure of the adiabatic ground-state potential surface for the ozone molecule

Institute for Physical and Organic Chemistry, Rostov University. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 6, pp. 15–20, November–December, 1991.     

Intrinsic defects in irradiated and annealed GaAs detected by FTIR

GaAs has been subjected to fast neutron or electron irradiations up to doses of 2×10¹⁹ n cm^–2 and 10¹⁹ e^– cm^–2 respectively and subsequently annealed to temperatures of 500°C. Infrared absorption spectra (20–700 cm^–1), measured at 20 K, show that the induced one-phonon absorption depends on the nature of the radiation. Resonant modes, at 45 cm^–1 and 119 cm^–1, and a broad line at 328 cm^–1 were found in neutron irradiated material, whereas in electron irradiated material only the 45 cm^–1 feature was detected. These spectroscopic features are interpreted as vibrational modes arising from intrinsic defect centres.     

Structure and electronic spectra of 2-phenylbenzimidazoles. Quantum chemical analysis of the intramolecular hydrogen bond

Institute of High-Molecular-Weight Compounds, Russian Academy of Sciences. Leningrad State University Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 5, pp. 20–27, September–October, 1992.     

Oxygenated acids of the reserve lipids of Rumex paulsenianus

The composition of the fatty mono- and dihydroxy acids of the fruit ofRumex paulsenianus Rech. fil. (familyPolygonaceae) has been determined by a combination of IRS, UVS, GLC, and mass-spectrometric methods. (22) Monohydroxy acids of the C₁₄–C₂₀ series, including isomers and isologues, and four dihydroxy acids from C₁₈ to C₂₀, including a new isomeric 9-OH-10, 12–17:2 acid have been detected.Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 762–765, November–December, 1991.     

Activity Coefficients of Potassium Chloride in Water–Ethanol Mixtures

Activity coefficients of KCl were determined in water–ethanol solvents in the range 5–20% (w/w) ethanol, from experimental electromotive force (emf) data. The molalities varied from 0.1 mol-kg^–1 to near saturation and measurements were taken in the temperature range 25 to 45°C. The Pitzer model was used to describe the nonideal behavior of the electrolyte and the corresponding coefficients were determined for each solvent. The Pitzer–Simonson equations were also applied and found superior in the study of KCl in those nonaqueous solutions.     

Transformations of cellulose at elevated temperatures

Summary The presence of 2–20% of glucose in cellulose during its thermal degradation results in a reduction in the yield of levoglucosan from 55–60% to 30%.     

Kinetics of glucose mutarotation in aqueous isopropanol

Kinetics of glucose mutarotation was studied in the range 283–308 K in water-isopropanol mixtures with alcohol fractions of 0–20 mol %. In dilute solutions (0–6 mol % of i-PrOH), the process is catalyzed by water exclusively. The water-isopropanol system sharply differs in kinetic behavior from the water-urea system.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 9, 2004, pp. 1563–1565.Original Russian Text Copyright © 2004 by Panov, Sokolova.This revised version was published online in April 2005 with a corrected cover date.     

Neutron Activation Analysis of Bottom and Fly Oil Ash Leachates

Seven samples of oil fly and bottom ashes were leached with water using a Canadian standard test method for shake extraction of solid waste. The concentrations of 20 elements in the leachates were determined by the computerized systematic instrumental absolute neutron activation analysis. The ranges of concentrations (in ppm) found for the elements in the leachates were: Al (3–526), Ba (0.5–6), Ca (100–695), Cl (13–59), Co (1–6.3), Cr (0.2–6.6), Cs (0.03–0.4), Eu (0.003–0.01), Fe (28–690), K (42–464), La (0.3–49), Mg (214–3150), Mn (1.2–20), Na (88–4050), Sb (0.04–0.4), Sc (0.003–0.07), Sr (1.2–23), U (0.07–1), V (1.2–4540) and Zn (2.3–200). These findings were compared with the maximum concentrations allowed for these elements by Canadian regulations. The concentrations of Cr and U were found to be higher than their permissible limits on 7 occasions. The purpose of this study was to determine the background levels of different elements in oil ash leachates, in order to evaluate their potential impact on underground water.     

Quality control in the analysis of lead and cadmium in blood

Summary An extensive quality control programme has been developed within a global UNEP/WHO project on Assessment of Exposure to Lead and Cadmium through Biological Monitoring. This project was coordinated by the Karolinska Institute (Department of Environmental Hygiene) and the National (Swedish) Institute of Environmental Medicine. The project was carried out within the framework of UNEP's Global Environmental Monitoring System (GEMS) and was initiated in 1978 on the basis of recommendations from a UNEP/WHO meeting of a Government Expert Group on Health-Related Monitoring.On termination of the project in 1981 it was decided to extend the analytical QC assurance programme on a periodic basis in order to maintain the analytical capability of the participating laboratories. A QC programme was conducted by our Institute in a follow-up study of the above mentioned UNEP/WHO programme and for a National Swedish Board of Occupational Safety and Health project, as well as for a recently concluded project in which a decrease in bloodlead levels in residents of Stockholm for the period 1980–1984 was established.In the latter project decreased blood-lead levels of about 20% were found in samples stored frozen (–20 ° C) for 4 years. This finding stimulated a study of the long-term stability of our QC samples. Results of lead and cadmium analyses performed for each QC sample during 1980–1985 were computerized. The results showed that the QC samples appeared to be stable for 2–3 years when stored at –20 °C. The losses of cadmium were 5 –10% in 5–6 years of storage at –20 ° C and seem to be less than those of lead (7–15%). Analysis of several QC sets, prepared on different occasions, but analyzed on the same day, confirmed that losses occur.     

Chemical investigation of biomass of a culture of ginseng cells III. Polysaccharides of a callus culture of ginseng

A water-soluble polysaccharide fraction has been isolated from a callus culture of ginseng with a yield of 16–20%. It has been shown that it included starch a and acidic polysaccharides — arabinogalactans and a xyloglucan.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok, All-Union Scientific Research Institute of Biochemical Machinery Design, USSR Ministry of the Medical Industry, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 771–772, November–December, 1989.     

Preparation of 21-aldehydes of Δ17(20)-steroids

A method is described for the synthesis of 17(20)-unsaturated 21-aldehydes by the oxidation of 17-hydroxy-17-vinylsteroids with pyridine chlorochromate. The following compounds were obtained in the course of the investigation: 3-hydroxy-trans-pregna-5,17-dien-21-al acetate, mp 177–178°C (MeOH); trans-pregna-5,17(20)-diene-3,21-diol 3-acetate (I), mp 150–153°C (MeOH); the 21-acetate of (I), with mp 130–133°C (ether-hexane); 3-oxo-trans-pregna-4,17(20)-dien-21-al, with mp 130–132°C (MeOH); and 3-oxo-trans-pregna-4,17(20)-dien-21-cic acid, C₂₁H₂₈O₃, mp 261–263°C. The IR and NMR spectra of the substances obtained are given.All-Union Scientific-Research Institute of Pharmaceutical Chemistry, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 340–342, May–June, 1979.     

Polymerization of alkyl vinyl ethers in presence of the sulfuric acid — aluminum sulfate complex

Conclusions In presence of the sulfuric acid — aluminum sulfate complex at 20° stereoregular polymers were prepared from ethyl vinyl, propyl vinyl, isopropyl vinyl, and isobutyl vinyl ethers in yields of 80–90%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 667–670, March, 1967.     

Hydrogenation of difurfurylideneacetone on a raney nickel catalyst

1.5-Difurylpent-1-en-3-one, 1,5-difurylpentan-3-one, 1,5-ditetrahydrofurylpentan3-one, and l,5-ditetrahydrofuryl-pentan-3-ol were obtained by hydrogenation of difurfuryldieneacetone on a Raney nickel catalyst at 20–65°C and atmospheric pressure. It was established that the hydrogenation of difurfuryldieneacetone is a zero-order reaction with respect to the concentration of the starting compound. The rate constants of the reaction were found; the activation energy found for 20–65°C is 6.2±0.5 kcal/mole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 462–465, April, 1979.     

Enzymatic production of glucose syrups from cellulose-containing plant wastes

A method has been developed for obtaining glucose syrups from cellulose-containing plant wastes under the action of a complex of cellulases from a hybrid strain of fungus. Purified glucose syrups containing 19–20 mg/ml of reducing sugars have been obtained.Institute of Microbiology, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 41 71 29. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 358–361, May–June, 1997.     

Synthesis of 20-hydroxyecdysone 25-acetate

A scheme has been developed for the selective conjugation of 20-hydroxyecdysone (20E) at the 25- position, with the synthesis of 20E 25-acetate as an example. The proposed scheme also permits the selective, synthesis of 20E 22-esters from both lower and higher fatty acids, which opens up prospects for the creation from them of drugs with a prolonged action.Institute of Biology, Komi Scientific Center, Urals Division of the Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, Vol. 33, No. 1, pp. 74–78, January–February, 1977.