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Voronezh region is one of the most important areas of agriculture and crop production. The purpose of the study was to study the patterns of accumulation of the most dangerous heavy metals in wild medicinal plant raw materials of various ecotopes of the Voronezh region. The accumulation of heavy metals (lead, mercury, cadmium, nickel, copper, zinc, cobalt, chromium) and arsenic was studied, using an example of 10 types of medicinal plant raw materials, which were produced in 51 ecotopes of the Voronezh region. When analyzing the average values of the accumulation coeffi cients of heavy metals and arsenic by all studied types of medicinal plant raw materials, it is possible to build up a series of decreases in the total average accumulation effi ciency of the determined elements for these plants, which is as follows: zinc> copper > cadmium > cobalt > nickel > arsenic > chromium > lead > mercury. When analyzing the values of accumulation coeffi cients, rows of decreasing effi ciency of accumulation of elements in all types of medicinal plant raw materials studied are constructed. A detailed analysis of the characteristics of the accumulation of heavy metals and arsenic from soils in medicinal plant raw materials showed the presence of aclose positive relationship between concentrations in soil and plants for most of the determined elements, which indicates the predominant contamination of plant raw materials through the soil.

The authors of the given article have studied the changes in structural and mechanical properties of Remanium GM 700 alloy caused by its consecutive smelting. To carry out mechanical testing the initial alloy pattern has been consecutively smelted 6 times according to the mode indicated by the producer, namely at melting temperature 13700 С and holding time of 10 minutes. Three types of coupons were produced at each smelting: 1. Coupon for the examination of microhardness in the form of flat parallel plate measuring 10х10х2 mm3 . 2. Coupon for the measurement of compliance modulus in the form of cylinder 36 mm high and 3mm in diameter. 3. 10 coupons for stretching in the form of bilateral spades with the body measuring 0.4х5х25 mm3 . Stretching stress-strain curves were registered with the deformation machine MRK-1 at the speed of 0.2 millimeters per minute. Conventional plasticity limit δ0,2, lasting quality limit δпр and maximum failure strain Σmax were determined on the basis of the received curves. Initial Remanium GM 700 coupon and consecutively smelted ones were studied in scanning electronic microscope JSM-820 with X-ray microanalysis system Link AN10/85S. Statistical analysis of the received data demonstrated considerable changes in the composition of coupons increasing with the number of smelting. On the one hand, this can be explained with the two-phase nature of the studied alloy. The most significant differences from the nameplate data are fixed for the value of maximum failure strain, since Σmax for the studied coupons remained lower than 1%, while the producer guarantees this value at 4% level. In case of δ0,2 and δпр indices high correspondence of the measured and nameplate values is fixed at least at the primary smelting. Correlation between the abovementioned stretching stress-strain curves and strain type is of great interest. Primary smelting features only type 1 curves, while type 2 curve appears after the third smelting with dominating sixth one. The research involved testing of 10 coupons after each smelting. Presented results of complex studies of mechanical properties of dental casting alloy Remanium GM 700 show their lowering with the increase of smelting quantity. While some coupons after the third smelting demonstrate crumbly features accompanied with significant reduction of strength properties. It should be noted here that the expectation of such alloy behavior is growing with the increase of smelting quantity. It proves the need for careful second use of the alloy for denture casting. No doubt, the reasons of such behavior can be found in structural changes caused by smelting

Based on mathematical and physicochemical modeling a studied the effect of alloying elements (chromium, molybdenum, vanadium) in the formation of the mechanical properties of steel. The intervals of the content of alloying elements that ensure the fulfillment of the required norms are determined. Dependences of the change in the mechanical properties of doped rolled steel from the index of the structural state d are constructed.

Background. From the analysis of exploitation of heat-resistant details of thermal power and metallurgical equipment, it was found that the basic characteristic of metallic materials working under extreme conditions is oxidation resistance. However, the choice of materials for work in the conditions of high temperatures and aggressive environments should be made taking into account not only its oxidation resistance but also the possibility of this material to work long time in the conditions of thermal cycling without being damaged, thus thinking about its heat-resistance. Consequently, it is tremendously important to determine the oxidation resistance of iron-based alloys in extreme conditions depending on the presence of main elements – chrome and aluminium – in their content on the basis of study of formation processes on the item surface of high-quality protective oxides films. Objective. The aim of the paper is to establish the selection rules of heat-resistant iron-based alloys for work in extreme conditions depending on temperatures and aggressive environments and to accumulate some information on their oxidation resistance for the creation of a database and development of methodology how to forecast special properties of alloys. Methods. Models with 10 mm in diameter and 20 mm in length were tested in a tubular stove at the temperature of 1200 and 1250 °C during 100 hours. Oxidation resistance was determined by a weight method. Phase composition and structure were explored by modern X-ray structural and metallographic methods. Results. Processes and mechanisms of formation of oxide scale in the conditions of exploitation of items under the temperature 1250 °C in different aggressive environments are established. The optimum boundaries of concentration of basic chemical elements – chrome and aluminium – in heat-resistant alloys for work in extreme conditions depending on temperatures and environments are determined. A database for development of methodology for forecasting of the special properties of Cr-Al steels depending on their chemical composition is created. Conclusions. Optimal concentration of chrome in heat-resistant Cr steels for work of items at temperatures up to 1100 °C can be considered 25–30 %. To provide high oxidation resistance of items working at temperatures up to 1250 °C in aggressive gas environments, the concentration of Cr in a metal should be within the limits of 25–30 %, and aluminium – from 2.0 to 3.5 %, the relation [% Cr]/[% Al] = 7–10 must be executed. Various gas environments differently effect on oxidation resistance of steels. At the temperatures of 1200 °C items in the water steam environment oxidize faster, and slower in the carbon dioxide environment.

The results of analysis of the systematics of Cr, Co and rare earth elements (REE) in ice-rafted sediments (IRS) of the northern part of the Beaufort Cycle (Arctic Ocean) are considered in the article. The IRS was assembled on the ARK-XIV-1/a cruise of the NIS Polarstern in 1998. The exact position of the sources of the IRS present in the ice has not been established to date. This is due, on the one hand, to the complex ice cycle in the Arctic Basin, on the other - a relatively small amount of data on the actual composition of the IRS. According to the views of most researchers, the main IRS supplier is the wide and shallow Siberian Arctic shelf. In the Beaufort Sea, the distinctive features of which are a much narrower shelf and almost constant presence of ice in the summer period, the conditions for the formation of the IRS are not so favorable. The contents of rare and scattered elements in the IRS samples were determined with the help of INAA at GEOKHI RAS. As a result of the research it was established that variations (La/Yb)N in the IRS from the northern part of the Beaufort cycle are characterized by the values 8.5-15.5. They fully correspond to the average value of this parameter in the suspension of pp. Mackenzie and the Arctic-Red River (8.6 and 8.5) and the mean (La/Yb)N for the crystalline formations of the Canadian Shield (14.4). In the same range are included, the values of (La/Yb)N for the suspension of Yana and Lena rivers (8.7 and 12.4), which may indicate the possibility of the presence in the IRS of material borrowed on the shelf of the eastern Laptev Sea. In the Co-Cr diagram, there is no overlapping of the fields of the compositions of the present bottom sediments of the estuary of Yenisei River, on the one hand, and the eastern part of the East Siberian and Chukchi seas, on the other. Although the sediments of the delta of the Mackenzie River, comparable to the precipitation of the estuary of the Yenisei River. by the content of Cr and differ from them by a noticeably lower content of Co. In the Cr-La diagram, the IRS field occupies an essentially isolated position, yet still has a certain overlap with the precipitation fields of the Chukchi Sea and the delta of Mackenzie River. In the diagram (La/Yb)N-La/Co, the field of IRS composition has a ≈50% overlap with the field of the present bottom sediments composition of the Chukchi Sea. The middle point of the suspension also gravitates towards Lena River, and the point of the Canadian Shield is relatively close, as well as the points of suspension of Mackenzie and Arctic-Red rivers and PAAS. Overlapping of the IRS fields and modern bottom sediments of the Ob and Yenisei estuaries, as well as the east of the East Siberian Sea, on the contrary, is not observed. The data given in the article allow us to conclude that the IRS in the area of the North Pole contains sedimentary material, borrowed both on the shelf of the Beaufort Sea and on the shelves of the eastern part of the Laptev Sea and the Chukchi Sea.

Chromium is an element belonging to micronutrients, which is about 0.012% of the coating earth. Chrome Latin language. chromium was discovered in 1798 by the French researcher Louis Nicolas Vauquelin in the periodic table element belongs to the group VI A transition having an atomic number of 24 and an atomic weight of 51.996, chrome "Chroma" in Greek means "color". It owes its name to chemical compounds, which element is formed on all oxidation; +1 to + 6 [4,7,8]. Chromium is an element which, in the environment occurs in two forms as Cr (III) and Cr (VI) [4,5,6,8]. The role of the element in the human body primarily is seen in the metabolism of carbohydrates, proteins, lipids, and especially cholesterol levels [1]. Chromium as a chemical compound in the oxidation of Cr (III) is part of enzymes, ribonucleic acids, accelerates blood coagulation and also increases the activity of B-glucuronidase. The properties element plays a key role in the antioxidant during the synthesis of RNA and DNA immune response affects the synthesis of certain vitamins and hormones. In adult women for the correct standard daily intake of chromium with the diet I recognize the value of 25 µg in men 35 µg [7,8]. Keywords: chrome, diabetes, cardiovascular disease, hypoglycemia, supplementation

Objective: To assess mid-term and long-term results of metal-on-metal total hip arthroplasty., Material and Methods: There were 349 operations for the period 2006-2012 in our clinic. Sixty-four patients underwent a full examination. All patients underwent X-ray examination of the pelvis, MRI of hip joint with metal artifact reduction sequence (MARS). The concentration of cobalt and chromium metal ions was determined in blood serum. Each patient completed a questionnaire (Harris, Oxford, Womac, SF-36). 'Survival' of endoprostheses was calculated using the Kaplan-Meier method., Results: According to the Oxford scale, 76.6% of patients had excellent clinical and functional outcomes, 10.9% - good, 9.4% - satisfactory, 3.1% - unsatisfactory. According to the Harris scale, 57.9% of patients had excellent results, 15.6% - good, 7.8% - satisfactory, 18.7% - unsatisfactory. Inclination less than 45 degrees was noted in 77.2% of acetabular components. It is optimal installation angle. According to MRI data, effusion was the main type of periprosthetic changes (16 cases). There were no periprosthetic changes in 33 cases. Pseudotumor was diagnosed in 5 cases. Mean concentrations of cobalt and chromium ions were 1.27 (13.57-0.12) and 0.59 (0.4-0.87) µg/l, respectively. Normal concentration of chromium ions was observed in all cases. Kaplan-Meier survival rate of endoprostheses was 89% (80-97%)., Conclusion: There was no correlation between female sex, young age of patients and incidence of complications. It is necessary to exclude pseudotumor in case of pain syndrome and no signs of aseptic loosening of the components of the endoprosthesis.