Исследование игровой задачи торможения диска в случае постоянных управлений

The process of braking a disk in the form of a differential game is studied. The dynamic system is based on the Coulomb friction model. The existence of a game value in the case of constant controls of the players is analyzed for different values of initial velocities and parameters of the disk. The aim is to minimize the braking distance. For each case, the guarantees of the first and second players are examined, and a statement about the existence or nonexistence of a game value is formulated. For example, it is shown that in the case of slip-free braking, there exists a game value, and it is attained when the first player applies the greatest possible control allowing him not to slip and the second player minimizes the friction. In the conclusion of the paper, we prove a final theorem stating that the slip-free mode is the best braking mode for the first player under constant controls. © 2019 Krasovskii Institute of Mathematics and Mechanics. All rights reserved

Возрастная и сезонная изменчивость состава эфирного масла ели европейской

An essential oil from foliage of Picea abies growing at territories removed from technogenic influence, has been obtained by the hydrodistillation method. The essential oil content in foliage has been determined. The composition of the oil has been studied by gas chromatography, and 19 main components with content 1% w/w or higher, have been identified. It has been established that the yield of essential oil depends on age and sampling time of the green mass. Age and seasonal variability of the oil composition has been studied.Методом гидродистилляции получено эфирное масло хвои ели европейской, произрастающей на территории, удаленной от техногенного воздействия. Определено содержание эфирного масла в хвое ели европейской в расчете на а.с.с. Газохроматографическим методом исследован компонентный состав масел. Идентифицировано 19 основных компонентов эфирного масла, содержание которых превышает 1 мас.%. Установлено изменение выхода эфирного масла с возрастом и временем отбора древесной зелени. Изучена возрастная и сезонная изменчивость состава елового масла

Вариабельность основных компонентов эфирного масла пихты одноцветной ( Abies concolor), произрастающей в условиях урбанизированной среды

The chemical composition of essential oil from A. Concolor growing in urban environment has been studied, 48 ingredients being identified and their content measured. The results obtained demonstrate the relationship between certain ingredients’ content and envuironment pollution by toxic elements, that can be used as an indicator of the environment condition.Исследования позволили детально рассмотреть химический состав эфирного масла пихты A. Concolor , произрастающей в условиях урбанизированной среды, идентифицировать и количественно измерить содержание 48 компонентов. Представленные результаты наглядно демонстрируют зависимость содержания отдельных компонентов в масле от степени загрязненности территории произрастания токсичными элементами и могут использоваться в качестве индикатора состояния окружающей среды

Метастатическое поражение кожи при меланоме

In order to evaluate the incidence, clinical features and prognosis of cutaneous tumor metastases, the records of adult patients with melanoma treated over a thirteen year period were examined. The diagnosis of Melanoma skin metastases was established in 221 (11,3%) of 1,948 patients. Each diagnosis was histologically confirmed by evaluation of both the primary tumor and the skin. Metastatic cutaneous melanoma presented with a wide variety of lesions: satellite, thrombophlebitis-like, inflammatory and nodular. In some cases the combination of satellite and nodular metastases was observed. Cancer patients with cutaneous metastases have a poor prognosis: the median survival of these patients is reduced by almost a half in comparison with cancer patients without cutaneous metastases.Для оценки частоты, клинических особенностей и прогноза кожных метастазов опухоли был произведен анализ данных за 13-летний период. Под наблюдением находилось 1948 пациентов с морфологически верифицированной меланомой, из которых у 221 (11,3%) пациентов были выявлены метастазы в кожу. В зависимости от клинической картины кожных метастазов меланомы и путей их метастазирования мы выделили следующие формы: сателлитная, тромбофлебическая, рожеподобная и узловая. В некоторых случаях диагностировали одновременно сателлитную и узловую формы. Медиана выживаемости больных меланомой с метастазами в кожу снижается почти вдвое по сравнению с пациентами с меланомой без кожных метастазов

Application of NMR spectroscopy in predicting hydrogel matrix stability by “stress” testing method

The results of the study of hydrogel matrix stability by means of nuclear magnetic resonance spectroscopy are described in the article. Ionizing radiation effect on auxiliary substances and active ingredients of hydrogel polymeric matrixes have been studied. It has been proved that under the influence of high-velocity electrons at absorbed doses 25–35 kGy the formation of a three-dimensional polymeric structure of the matrix occurs. It has been ascertained that active ingredients of hydrogels miramistin and gentamycin are stable under absorbed radiation doses in the range 5–35 kGy

Project of method developing of quality control of spruce essential oil by gas-liquid chromatography

Conditions of the chromatography analyses of essential oils providing the yield of all components with the contents over 0.01% were selected. Essential oils of 10 samples of Norway spruce growing in the same edaphic-climatic conditions of the park UE “Brovki” were obtained by hydrodistillation. Qualitative and quantitative analyses of the received essential oils were performed. More than 50 components composing the essential oil were identified. The obtained statistic data allowed to calculate standard deviation of repeatability, standard deviation of intermediate precision with a variable factor “time + operator”, expanded uncertainty of measurement results for the confidence level P = 0,95

Development of a new shampoo type with fir essential oil additive

Samples of 6 shampoos with the addition of experimentally developed fir fragrances were developed in the laboratory. Softwood essential oil of fi r (20%) and synthetic fragrances were used as the main component for the development of new fragrances. Physical-chemical tests have been carried out in order to confirm the quality and safety of new types of shampoos. Consumer evaluation of the developed samples of shampoos was carried out by organoleptic method. The sample of shampoo was de-fined, its development is reasonable as a tast ing item, and in terms of quality and safety

Influence of the constituent composition on antimicrobial and perfume properties of fir essential oils

The essential oils of 7 kinds of spruces by the method of steam distillation were obtained. The qualitative and quantitative composition of the received essential oils was studied by gas-liquid chromatography. Antimicrobial activity of essential oils on substances Staphilococcus aureusATSS 6538 P, Pseudomonas aeruginosaATSS 9027, Bacillus subtilisATSS 6633, Candida albicansATSS 885-653 was defined. Perfume tasting evaluation of the essential oils was made

New functional food fat and oil products with a balanced fatty acid composition

New functional mayonnaises with a balanced composition ω -3 and ω -6 fatty acids were developed. Raw vegetable oils (sunflower, linseed, rape seed and corn) were selected and their compositions are investigated by using gas-liquid chromatography at the first stage. The investigation, fatty acid composition of natural oils showed that none of them can’t to provide introduction of essential fatty acids into the human organism in the required quantity and right proportion. The blends of vegetable oils with a balanced composition of polyunsaturated fatty acids was calculated in the second stage. Basic physico-chemical properties of the obtained samples of blends of vegetable oils were established. In the third step, the functional mayonnaise recipes using obtained blends of vegetable oils have been developed. development types of mayonnaise were produced in the laboratory of JSC “Minsk Margarine Plant”, it was defined their physico-chemical and organoleptic ch aracteristics. It was found that the physico-chemical and organoleptic quality ratings, obtained mayonnaises meet requirements imposed on them in the fullest extent. In the fourth stage, the fatty acid composition of the obtained mayonnaises was investigated. It is found that the mayonnaise retained their fatty acid composition during manufacture and storage, and consequently their functional properties. The results of the research confirmed the possibility of the release of mayonnaise on the base of proposed blends, because they are fully meet by the physico-chemical and organoleptic quality ratings are established in the requirements of the standard STB 2286 “Mayonnaise and mayonnaise sauces. General specifications

Identification of the plant oil composition by chromatographic and spectral methods

This article presents the results of research by chromatographic and spectroscopic methods of fatty acid composition of vegetable oils which sold in the trading network of the Republic of Belarus, it also presents an assessment of their quality characteristics from the standpoint of modern views on food hygiene. It was found, that the vegetable oils include both saturated and unsaturated fatty acids with one or two double bonds. Two samples of sunflower oil was found in the analysis that do not meet the requirements of the quantitative content of oleic and linoleic acids. Quality counterfeits were also found among the tested olive oils. Fatty acid composition must be controlled continuously during production and use of vegetable oils, and especially mixtures thereof. The combination of spectroscopic and chromatographic methods allows obtaining detailed picture of analysis of the fatty acid content in oils