EBSD characterization of cryogenically rolled type 321 austenitic stainless steel

Electron backscatter diffraction was applied to investigate microstructure evolution during cryogenic rolling of type 321 metastable austenitic stainless steel. As expected, rolling promoted deformation-induced martensitic transformation which developed preferentially in deformation bands. Because a large fraction of the imposed strain was accommodated by deformation banding, grain refinement in the parent austenite phase was minima

Quest for Methods to Increase Aerobic Capacity in Cyclic Sports

Quest for new techniques to increase the aerobic training of the athletes, attempts to apply the methodology of training for semi-skilled athletes based on increasing of VO2 max (Maximal Oxygen Consumption) in slow twitch muscle fibersВ статье рассмотрены поиски новых методик повышения аэробной подготовки легкоатлетов, попытка применить методику тренировки на спортсменах средней квалификации, основанную на повышении МПК в отдельно взятых медленных мышечных волокна

EBSD investigation of microstructure evolution during cryogenic rolling of type 321 metastable austenitic steel

Electron backscatter diffraction (EBSD) was employed to establish microstructure evolution in type 321 metastable austenitic stainless steel during rolling at a near-liquid-nitrogen temperature. A particular emphasis was given to evaluation of microstructure-strength relationship.As expected, cryogenic rolling promoted strain-induced martensite transformation. The transformation was dominated by the γ→α′ sequence but clear evidence of the γ→ε→α′ transformation path was also found. The martensitic reactions were found to occur almost exclusively within deformation bands, i.e., the most-highly strained areas in the austenite. This prevented a progressive development of deformation-induced boundaries and thus suppressed the normal grain-subdivision process in this phase. On the other hand, the preferential nucleation of martensite within the deformation bands implied a close relationship between the transformation process and slip activity in parent austenite grains. Indeed, the martensite reactions were found to occur preferentially in austenite grains with crystallographic orientations close to Goss {110} and Brass {110}. Moreover, the martensitic transformations were governed by preferential variant selection which was most noticeable in ε-martensite. The sensitivity of the martensitic reactions to the crystallographic orientation of the austenite grains resulted in re-activation of the transformation process after development of a deformation-induced texture in the austenitic phase at high strains. Both martensitic phases were concluded to experience plastic strain which resulted in measurable changes in misorientation distributions. Cryogenic rolling imparted dramatic strengthening resulting in a more-than-sixfold increase in yield strength. The main source of hardening was the martensitic transformation with lesser contributions from dislocations and subboundary strengthening of the austenite

СОВРЕМЕННЫЕ ТЕНДЕНЦИИ WEB-РАЗРАБОТКИ

This paper reviews and analyzes popular website designs to identify trends and changes in the emergence of Internet resources. Some current trends that have been observed in web development over the past year were reviewed.В данной работе рассматриваются и анализируются популярные разработки веб-сайтов для выявления тенденций и изменений в появлении интернет-ресурсов. Рассмотрены некоторые текущие тенденции, которые наблюдались в веб-разработке за последний год

АНАЛИЗ ФУНКЦИОНИРОВАНИЯ СИСТЕМЫ ОЦЕНКИ ЗНАНИЙ ОБУЧАЮЩИХСЯ

This research work revealed the advantages of a score-rating system (BRS) in a higher educational institution and proved that BRS can be applied in the educational process as a knowledge assessment system and one of the means to increase academic motivation, develop independent activity skills, develop initiative, leadership qualities of students.Данная исследовательская работа позволила выявить преимущества балльно-рейтинговой системы (БРС) в высшем учебном заведении и доказала, что БРС может быть применима в учебном процессе как система оценки знаний и одно из средств повышения учебной мотивации, формирования навыка самостоятельной деятельности, развития инициативности, лидерских качеств у студентов

Electrocatalytic determination of dithiocarbamate-based pesticides using electrodes modified with metal phthalocyanines

An electrocatalytic method has been proposed for determining dithiocarbamate-based pesticides (carbathion, nabam, ferbam, thiram, and thiuram) using a carbon-paste electrode modified with iron(II) and cobalt(II) phthalocyanines. The first wave of carbathion oxidation in botli aqueous and organic solutions does not change compared to an unmodified carbon-paste electrode; for the second stage of oxidation, a decrease by 100 mV in the overpotential and a significant increase in the current are observed. The electrochemical signal is observed in the range of potentials characteristic for the oxidation of metal phtlialocyanines, and the metal phthalocyanine serves as the electron carrier. A similar effect is observed for the electrochemical oxidation of nabam. The catalytic activity of the metal phtlialocyanines to ferbam, thiram, and thiuram in acetone has been determined. In the case of the electrochemical oxidation of ziram and zineb, the electrocatalytic effect is not observed. The dependence of the peak current on the pesticide concentration is linear within the range from 1 × 10-3 to 1 × 10-7 M. The adsorption preconcentration of pesticides decreases the limit of detection by an order of magnitude. © 2001 MAIK "Nauka/Interperiodica"

Magnetic microstructure of oxygen-deficient perovskites

Samples of oxygen-deficient perovskites were studied by means of Mossbauer spectroscopy. The Mossbauer spectra were obtained at room temperature. X-ray data confirmed the ordered distribution of iron and copper deduced from Mossbauer spectroscopy data

Mössbauer study of some perovskite-related oxides

Complex perovskite-related oxides with various structure types: orthoferrites, 4-1-5, 8-8-20, and 1-2-3 were studied using Mössbauer spectroscopy. Correlations between magnetic ordering of iron atoms and their structural coordination, as well as between oxygen deficiency and iron ion valence, were found. © 2006 by Allerton Press, Inc