Determination of water-soluble forms of oxalic and formic acids in soils by ion chromatography

Carboxylic acids (CA) play an important role in the chemical composition origin of soils and migration of elements. The content of these acids and their salts is one of the important characteristics for agrochemical, ecological, ameliorative and hygienic assessment of soils. The aim of the article is to determine water-soluble forms of same carboxylic acids - (oxalic and formic acids) in soils by ion chromatography with gradient elution. For the separation and determination of water-soluble carboxylic acids we used reagent-free gradient elution ion-exchange chromatography ICS-2000 (Dionex, USA), the model solutions of oxalate and formate ions, and leachates from soils of the Kola Peninsula. The optimal gradient program was established for separation and detection of oxalate and formate ions in water solutions by ion chromatography. A stability indicating method was developed for the simultaneous determination of water-soluble organic acids in soils. The method has shown high detection limits such as 0.03 mg/L for oxalate ion and 0.02 mg/L for formate ion. High signal reproducibility was achieved in wide range of intensities which correspond to the following ion concentrations: from 0.04 mg/g to 10 mg/L (formate), from 0.1 mg/g to 25 mg/L (oxalate). The concentration of formate and oxalate ions in soil samples is from 0.04 to 0.9 mg/L and 0.45 to 17 mg/L respectively

SBS 0335-052W: The Lowest-Metallicity Star-Forming Galaxy Known

We present 4-meter Kitt Peak telescope and 6.5-meter MMT spectrophotometry of the extremely low-metallicity galaxy SBS 0335-052W, the western companion of the blue compact dwarf galaxy SBS 0335-052E. These observations have been combined with published 10-meter Keck data to derive for the brightest region of SBS 0335-052W an oxygen abundance 12+logO/H=7.12+/-0.03. This makes SBS 0335-052W the lowest metallicity star-forming galaxy known in the local universe. Using a Monte Carlo technique, we fit the spectral energy distribution of SBS 0335-052W to derive the age of the oldest stars contributing to its optical light. We find that star formation in SBS 0335-052W began less than 500 Myr ago, making it a likely nearby young dwarf galaxy.Comment: 13 pages, 3 figures, accepted for publication in the Astrophysical Journa

“Showy”, “Music-hall” America: To the Centenary of Sergey Esenin’s Essay Iron Mirgorod

The article analyzes the image of America created by S.A. Esenin after his trip to the West with I. Duncan in the essay “Iron Mirgorod” (1923) and offers a comprehensive analysis of the poetics and the main sources of his text. Esenin was the first Soviet poet to visit America and create an essay about it, taking into account the rich literary tradition and his own vivid impressions. During his four month stay in America the poet lived in the New York City and visited 14 cities, in 11 states: Baltimore, Boston, Detroit, Indianapolis, Kansas City, St. Louis, Cleveland, Toledo, Toronto, Louisville, Memphis, Milwaukee, Philadelphia, Chicago. In connection with the history of the creation and publication of the essay, the article pays attention to the ambiguous semantics of its title, its connection with reality and literary sources — the cycle of essays by M. Gorky’s In America (1906) and N.V. Gogol’s works, including the collection of novellas Mirgorod (1835). The researcher analyzes the multilevel content, the correlation between the external and internal dialogue and the creation of a complex and contradictory image, in which the showy, festive, carrying the “banner of industrial culture” is contrasted with the “music hall” America. The article reveals Esenin’s polemics with the poem 150 000 000 writen by Mayakovsky “on the basis of pictures” taken from old magazines, “translating Whitman” (most of Esenin‘s attacks against Mayakovsky were not published) and his controversy with Russian urbanists (those from “Kuznitsa,” “LEF”). Esenin’s deep concern for the problems of modern spirituality and culture was expressed in categorical and sometimes shocking tone of his assessments and judgments, oddity of style and the pecularity of genre — the essay is written in an ironic manner balancing between satire and grotesque. Carrying on a dialogue with Gogol, Esenin extremely sharpens the contradictions of real America and warns against choosing the American path of development with its exceptionalism, false pride of being “cultured”, “immersion in business” and “the power of dollar.

The Choice of Conditions for the Determination of Vanadium, Chromium and Arsenic Concentration in Waters by ICP-MS Using Collision Mode

Inductively coupled plasma mass spectrometry (ICP-MS) is a popular method for the analysis of waters with various matrices and salinity. One of the difficulties of routine measurements by ICP-MS is spectral interferences conditioned by polyatomic ion formation in the plasma. The detection of the background concentration of such elements as vanadium, chromium and arsenic in natural waters by ICP-MS is complicated because of the polyatomic interferences, having the same mass-to-charge ratio. Thus, the purpose of this article is to determine the optimal rate of helium flow for the effective correction of polyatomic interferences of vanadium, chromium and arsenic and the reduction of their detection limits in Cl-rich waters. This research has been carried out using an inductively coupled plasma mass spectrometer NexION 300D with a universal cell technology (UCT) (PerkinElmer, USA) and three model solutions. For the detection of vanadium, chromium and arsenic content in chloride matrix water by ICP-MS, a collision mode is preferable for polyatomic interference correction. The optimal helium flow rate for this purpose is 2.5 ml/min. Under these conditions, the detection limit of vanadium, chromium and arsenic decreases by order of two

Innovative Approaches to Teaching Foreign Languages at the University

The article is concerned with the substantiation of innovative approaches to teaching foreign languages at the university. It is established that during the professional training of specialists at the university, the special emphasis should be given to the application of innovative forms and methods of training aimed at qualitative mastering of knowledge, abilities, and skills, developing students’ mental activities, identifying skills of critical addressing the problems, gaining experience of independent learning of training materials, conducting exploration work, and gaining qualities that will be useful in professional activities and later in life. It is proved that the effectiveness of teaching foreign languages at the university will depend on the desire and ability of teachers to take advantage of successful practices in the humanistic approach to teaching, understanding the need to abandon authoritarian and scholastic teaching methods

Innovative Approaches to Teaching Foreign Languages at the University

The article is concerned with the substantiation of innovative approaches to teaching foreign languages at the university. It is established that during the professional training of specialists at the university, the special emphasis should be given to the application of innovative forms and methods of training aimed at qualitative mastering of knowledge, abilities, and skills, developing students’ mental activities, identifying skills of critical addressing the problems, gaining experience of independent learning of training materials, conducting exploration work, and gaining qualities that will be useful in professional activities and later in life. It is proved that the effectiveness of teaching foreign languages at the university will depend on the desire and ability of teachers to take advantage of successful practices in the humanistic approach to teaching, understanding the need to abandon authoritarian and scholastic teaching methods

Size fractionation of trace elements in the surface water and groundwater of the Ganjiang River and Xiushui River basins, China

The research of trace element behaviour and size fractionation is significant to understand the processes in the water-rock system. Moreover, the aqueous speciation of trace elements is strongly related to their distribution and toxicity. In this research, trace elements behaviour and their size fractionation are investigated in the natural water (the surface water and shallow groundwater) of the Ganjiang River and Xiushui River basins. Trace element concentrations were measured by ICP-MS. The authors estimated the size fractionation of the trace elements between suspended forms (>0.45 [mu]m) and dissolved fractions, which included truly dissolved (1 kDa) and colloidal particles (0.45 [mu]m-1 kDa)), after filtration through a 0.45 [mu]m acetate cellulose membrane filter. The distinct features of the trace element size fractionation were identified. The size fractionation of the trace elements under different conditions (in the surface water and shallow groundwater) was studied

Innovative Approaches to Teaching Foreign Languages at the University

The article is concerned with the substantiation of innovative approaches to teaching foreign languages at the university. It is established that during the professional training of specialists at the university, the special emphasis should be given to the application of innovative forms and methods of training aimed at qualitative mastering of knowledge, abilities, and skills, developing students’ mental activities, identifying skills of critical addressing the problems, gaining experience of independent learning of training materials, conducting exploration work, and gaining qualities that will be useful in professional activities and later in life. It is proved that the effectiveness of teaching foreign languages at the university will depend on the desire and ability of teachers to take advantage of successful practices in the humanistic approach to teaching, understanding the need to abandon authoritarian and scholastic teaching methods