Development of an aluminium matrix composite material with the addition of dispersed particles of graphite, operating under conditions of increased friction

The paper proposes a method for obtaining a composite material based on aluminum with the introduction of dispersed particles of graphite powder at the stage of obtaining samples. On the obtained experimental samples, which are cylinders with a diameter of 20 mm. and a height of 10 mm, and the properties of this material, namely hardness and wear resistance

ANALYSIS OF POSSIBLE ENHANCEMENT OF PROPERTIES OF VK15 MATERIAL USED FOR DRILLING TOOLS

Traditionally, when drilling hard and abrasive rocks, it is recommended to use a tungsten-cobalt hard alloy VK15. The analysis of information on the possibility of improving the potential of the material has demonstrated the existence of mechanisms that provide structural transformations that enhance its strength, hardness and toughness. The use of such technology instead of traditional methods will lead to an increase in the operating efficiency and durability of the tool. During the work, experimental samples of alloy VK15 were obtained by sintering in four different modes. Then their properties were analyzed. The results of the metallographic study carried out on the «Carl Zeiss» microscope made it possible to estimate the distribution of tungsten carbide grains in cobalt bon and show the grinding of the carbide phase. Thus, with traditional sintering, the amount of tungsten carbide grains with an average size of less than 1 μm in diameter from the entire size range reaches 19.5 %, while after additional heat treatment with a holding time of 1280 °C, the value was 41.5 %; 900 °C – 59.1 %; 600 °С – 54.5 %. The maximum improvement results were the following: hardness by 18 %, a coercive force by 49 %, and crack resistance by 11 % of the traditional alloy, there were achieved at 900-1280 °C. A hypothesis has been put forward on the formation of additional structural elements not detected by the methods of optical metallography. Studies of the topology and structure of the samples on an atomic force microscope confirmed the presence of nanoscale inclusions from 20 to 40 nm (presumably tungsten carbide) in a cobalt bond. For VK15, comparative studies of properties and analysis of the microstructure of experimental samples obtained by the traditional sintering and modified technology have shown that the sintering mode at 900 °C is a priority. Thus, the developed technology, including the sintering of powders in a hydrogen stream up to 750 °C, from 750 to 1450 °C in vacuum, feeding at a maximum temperature of 1450 °C for 15 minutes of argon at a pressure of 60 bar, subsequent cooling to 900 °C and 1 hour exposure, can be recommended as the most rational conditions for revealing the potential of the material and providing an enhanced level of properties of the drilling tool

Possible association between corneal infections and contact lenses wearing to correct ametropia in children

Possible association between corneal infections and contact lenses (CLs) wearing of various design to correct ametropia in children was analyzed. Between 2011 and April 2014, 20 children (7 boys, 13 girls) aged 9‑17 years which were diagnosed with traumatic keratitis were admitted to Morozov Children’s Hospital. All patients used CLs (rigid, n = 1; soft, n = 9; orthokeratology, n = 10) to correct ametropia for 6‑48 months. There are pretty strong evidences that CLs (including orthokeratology ones) provide better quality of vision and life as compared with spectacles, reduce myopia progression, and promote better accommodation. However, in spite of these advantages, CLs have disadvantages as well. People who wear CLs may require frequent eye care specialist follow-up due to the higher risk of corneal disorders. Even nearly perfect CL represents a foreign body (especially for a children eye) that may provoke numerous complications including severe ones. With accurate fitting, proper care, and careful monitoring of the cornea, CLs should be safe and effective

PRIORITY DIRECTIONS AND STRATEGIES IN THE FIELD OF ENERGY SAVING AND RESOURCE CONSERVATION IN SAMARA REGION

The paper discusses the basic perspective directions of development of energy saving and resource conservation in Samara region. The authors analyzed the existing methods for producing energy, the most effective identified for the region to date. The directions and the results of the Samara leading scientific schools in the field of energy, the main problems of the region, ways to solve them.В работе рассмотрены основные перспективные направления развития энерго- и ресурсосбережения в Самарской области. Авторами проанализированы существующие способы получения энергии, выявлены наиболее эффективные для региона на сегодняшний день. Рассмотрены направления и результаты работы ведущих самарских научных школ в области энергетики, выявлены основные проблемы региона, предложены пути их решения

Concerning Preventive Activities Providing Control over Morbidity Rates in Reference to Flue, ARVI, and Community-Acquired Pneumonia in the Amur Region in the Post-Flooding Period

It is supposed that after exposure to impacts of the large-scale high water on the background of chronic persistent stress, immune activity of the organism is decreased, which may lead to sanitary-epidemiological implications and contribute to morbidity rate increment as regards a number of relevant nosological entities among the population of the devastated territory. Statistically community-acquired pneumonias are still one of the key factors for infectious morbidity, hospitalization and mortality rate in the region. They are indicators for organization of medical assistance to the population. Therewith, evaluated has been morbidity rate in reference to acute respiratory viral infections and community-acquired pneumonias in the Amur Region for the past three years, assessed has been epidemiological situation throughout 2013. Morbidity rate as regards community-acquired pneumonias in the Amur Region over the surveyed period (2010-2013) has turned out to be two times higher than the national one, and 60-70 % - than that throughout the Far Eastern Federal district. In order to avoid distribution of the acute respiratory viral infections, flue, and community-acquired pneumonias and epidemic foci formation in the territory of the Amur Region in the post-flooding period, established is a complex of sanitary-anti-epidemic (prophylactic) and remedial measures. Besides of that, identified are the main areas of activities aimed at stabilization of the situation as a long term strategy

Retrospective Analysis of Enterovirus Infection Morbidity Rate in the Territory of the Amur Region and Peculiarities of Epidemic Process in the Period of Large-Scale Flood

There has been observed a tendency to increment of enterovirus morbidity rate over the past seven years. Foci of this infection have been formed in the area from time to time, with minor forms of the disease being predominant in clinical findings. Genetically enteroviruses circulating in the Amur Region have been characterized as homogenous; however there is a genetic relation among them with and, consequently, epidemiologic connection to enteroviruses originated from China. However, since May, 2013 there has been detected a boost activation of epidemic process as regards enteroviral infection, followed by the formation of two major foci with clustered infection, due to importation from Thailand as well. Emergency situation under conditions of flood (August-September, 2013) has contributed to aggravation of epidemiological situation on enteroviral infection. It has led to the increase in numbers of the exposed up to the maximum level for the past few years. In the territory of the temporal accommodation sites, where affected by high water and exposed to the infection population was placed, registered have been the cases of clustered enterovirus infection

Цимолы. 4. Получение крезолов и их применение

Methods of cresols obtaining and the main directions of their applications were analysed. It was concluded that the synthesis of cresols on the basis of cymenes is most perspective nowadays.Проанализированы методы получения крезолов и основные направления их применения. Сделан вывод о том, что наиболее перспективным способом получения крезолов на сегодняшний день является синтез на основе цимолов

Цимолы. 1. Современное состояние процессов получения цимолов

The article analyzes methods for the preparation of cymenes based on using petrochemical raw materials: toluene and propylene/isopropanol. It is concluded that at present advanced technologies for the production of individual cymenes are absent, and the heterogeneous catalytic processes require significant improvement.Проанализированы методы получения цимолов, базирующиеся на использовании нефтехими-ческого сырья - толуола, пропилена/изопропилового спирта. Сделан вывод о том, что в настоящее время отсутствуют совершенные технологии получения индивидуальных цимолов, а гетерогенно-каталитические процессы требуют серьезной доработки

Sanitary-Hygienic and Microbiological Monitoring over the Water Supply Sources and Surface Water Reservoirs during Natural Disaster in the Amur-River Territory

Emergency situation in summer 2013 due to flooding of extensive areas of the Russian Amur-River territories (including residential areas with different level of development of public services and amenities, agricultural land, sites of cattle grazing and stock-keeping) resulted in the increased microbiological, virologic and physical-chemical load upon water reservoir ecosystems. The results of monitoring over water supply sources, quality of drinking water and surface reservoir waters in the devastated territories were analyzed by the specialists from Rospotrebnadzor and specialized anti-epidemic teams No. 1 and 2. Complex approach presuming increase in extent and frequency of the examinations, performance of operative epidemiological analysis along with daily adequation of preventive and anti-epidemic measures allowed for taking control over the situation and to avoid epidemic complications as regards acute water-borne intestinal infections