Excitability of Vascular Smooth Muscle

Regulation of pressure and local blood flow occurs at the level of resistance arteries and arterioles. Under physiological conditions, these small vessels exist in a state of partial constriction, termed myogenic tone. Myogenic tone is considered to be an intrinsic property of arteriolar smooth muscle cells, which membranes depolarize in response to increase in the intraluminal pressure. Oscillations of membrane potential in smooth muscles are mediated by the activity of voltage-gated L-type Ca2+ channels, which provide an influx of Ca2+ to activate various voltage-gated and Ca2+-sensitive channels of smooth muscle cells and to initiate endothelial Ca2+ signaling needed for vasodilation. Although a relationship between change in membrane potential and myogenic response is considered to be universal throughout various smooth muscle tissues, it may be regulated differently based on autoregulatory responses and channels expression. Here we review electrophysiological signature of arteriolar smooth muscle in various tissues, with an emphases and specific examples of the excitability of 4th order arterioles isolated from skeletal muscle

Commodity and Financial Networks in Regional Economics

The article discusses the relationship between commodity-production and financial network structures in the regional economy as dual conjugate systems. Material flows (raw materials, goods and so on) circulate in the commodity network as shown by Leontiev’s input-output balance model. Nonmaterial flows of property rights, money, and so on circulate in the financial network and reflect the movement of material objects in commodity networks. A network structure comprises closed and open circuits, which have fundamentally different characteristics: locally closed circuits meet local demand by supplying locally produced goods, thus ensuring self-reproduction of the local economy; open (or transit) circuits provide export-import flows. The article describes the mechanism of ‘internal’ money generation in closed circuits of commodity-production networks. The results of the theoretical study are illustrated by the calculations of closed and open circuit flows in the municipal economy model. Mutual settlements between the population and manufacturing enterprises are given in matrix form. It was found that the volume of the turnover in closed circuits of the municipal economic network model is about 28.5 % of the total turnover and can be provided by ‘internal’ non-inflationary money. The remaining 71.5 % of the total turnover correspond to the flows in the network’s open circuits providing export and import. The conclusion is made that in the innovation-driven economy, main attention should be given to the projects oriented towards domestic consumption rather than export supplies. The economy is based on internal production cycles in closed circuits. Thus, it is necessary to find the chains in the inter-industrial and inter-production relations which could become the basis of the production cycle. Money investments will complete such commodity chains and ‘launch’ the production cycle.The work has been prepared with the supprot of the Ural Federal University within the UrFU Program for the winners of the competition “Young Scientists of UrFU” No. 2.1.1.1-14/43

The Chinese diaspora and security issues in Southeast Asia

В статье рассматривается положение китайских диаспор в Юго-Восточной Азии и их влияние на формирование мирной обстановки в странах региона. Раскрыты основные виды конфликтов и определены факторы, формирующие комплекс противоречий между сообществами зарубежных китайцев в Юго-Восточной Азии и местным населением на государственном и муниципальном уровнях.The article deals with the position of the Chinese diaspora in Southeast Asia and their effect on the formation of a peaceful environment in the region. The author reveals the main types of conflicts and determine the factors that shape the complex contradictions between communities of overseas Chinese in Southeast Asia and the local population on the state and municipal levels

Estimating the demand parameters for single period problem, Markov-modulated Poisson demand, large lot size, and unobserved lost sales

We consider a single-period single-item problem when the demand is a Markov-modulated Poisson process with hidden states, unknown intensities and continuous batch size distribution. The number of customers and lot size are assumed to be large enough. The estimators of demand mean and standard deviation for unobservable lost sales in the steady state are considered. The procedures are based on two censored samples: observed selling durations and the demands over the period. Numerical results are given

Approaches of Russian oil companies to optimal capital structure

Oil companies play a vital role in Russian economy. Demand for hydrocarbon products will be increasing for the nearest decades simultaneously with the population growth and social needs. Change of raw-material orientation of Russian economy and the transition to the innovative way of the development do not exclude the development of oil industry in future. Moreover, society believes that this sector must bring the Russian economy on to the road of innovative development due to neo-industrialization. To achieve this, the government power as well as capital management of companies are required. To make their optimal capital structure, it is necessary to minimize the capital cost, decrease definite risks under existing limits, and maximize profitability. The capital structure analysis of Russian and foreign oil companies shows different approaches, reasons, as well as conditions and, consequently, equity capital and debt capital relationship and their cost, which demands the effective capital management strategy

Development of engineering solutions for air drilling at Dulisminsk oilfield, Irkutsk oblast

The article presents the analysis of disastrous mud loss achieved during casing at Dulisminsk oil and gas condensate field (DOGCF) and comparative evaluation of geological structure of DOGCF and Naryksko-Ostashkinsk area of Kemerovo oblast, where the same problem was solved successfully. On the basis of the analysis, an engineering solution is proposed to prevent mud loss in the conditions of DOGCF

Vertical section construction of wells at Kuyumbinsky oil field via percussive-rotary drilling with DTH hammer

The article presents the analysis of sequential use of mobile percussive-rotary drilling sets with DTH hammer and bottom-hole cleaning by foam mud in construction of vertical sections along with at Kuyumbinsky oil field. On the basis of the analysis, an engineering solution is proposed to prevent disastrous mud loss that is the key factor of efficiency in implementation of resource-saving technologies

Experimental research of drilling mud influence on mud motor mechanical rubber components

The paper describes the experimental research of drilling mud influence on engineering parameters of mud motor mechanical rubber components. It is believed to be urgent due to increase in using mud motors in oil and gas well construction now, and, consequently, the issue of increasing their exploitation is becoming current. The development test results of elastomer IRP-1226 dependent on the mud type (alkaline, hydrocarbon or salt-saturated ones) and the temperature are shown in the paper. It is proved that the type of drilling mud and the temperature in bottom-hole zone have an influence on wear of mud motors elastomers

Methods of study in the characteristics of elastomers' samples of mud motors at modeling the conditions of their operation

The paper describes the development of the methods of experimental research on rubber elastomers parameters of mud motors at modeling the conditions of their operation. The specific features of mud motors operation as well as main aggressive agents affecting the state and parameters of elastomers, such as drilling mud type, ambient temperature, and mechanical action of the rotor on the plate of the stator are shown in the paper. Due to described agents, new methods of investigations and new units of experimental bed are developed

Impact of hydrocarbon drilling mud on mud motor elastomers at different temperatures

The paper describes the experimental research of hydrocarbon drilling mud impact on engineering parameters of mud motor elastomer samples. It is believed to be urgent due to an increase in using mud motors in oil and gas well construction now, and the issue of intense exploitation is currently topical. The test results of elastomer IRP- 1226 dependent on the temperature are shown in the paper. It is proved that the hydrocarbon drilling muds have a significant impact on wearing of mud motors elastomers under the condition of a temperature increase