Electronic Quantum Transport in Graphene.

Graphene is a new two-dimensional material with interesting electronic properties and a wide range of applications. Graphene epitaxially grown on the Si-terminated surface of SiC is a good candidate to replace semiconductors in field-effect transistors. In this work we investigate the properties of epitaxial monolayer and bilayer graphene and develop a theoretical model used to describe the charge transfer between graphene and donors in SiC substrate. This model is then used to describe the behaviour of an epitaxial graphene-based transistor and the conditions for its operation. We also apply our model to understand the successful application of epitaxial graphene in quantum resistance metrology and to describe the effect of bilayer patches on the resistance quantization. Finally, we study how the ordering of adatoms on top of mechanically exfoliated graphene due to RKKY interaction affects the transport properties of graphene

Real-Time Long Range Trajectory Replanning for MAVs in the Presence of Dynamic Obstacles

Real-time long-range local planning is a challenging task, especially in the presence of dynamics obstacles. We propose a complete system which is capable of performing the local replanning in real-time. Desired trajectory is needed in the system initialization phase; system starts initializing sub-components of the system including point cloud processor, trajectory estimator and planner. Afterwards, the multi-rotary aerial vehicle starts moving on the given trajectory. When it detects obstacles, it replans the trajectory from the current pose to pre-defined distance incorporating the desired trajectory. Point cloud processor is employed to identify the closest obstacles around the vehicle. For replanning, Rapidly-exploring Random Trees (RRT*) is used with two modifications which allow planning the trajectory in milliseconds scales. Once we replanned the desired path, velocity components(x,y and z) and yaw rate are calculated. Those values are sent to the controller at a constant frequency to maneuver the vehicle autonomously. Finally, we have evaluated each of the components separately and tested the complete system in the simulated and real environments

Transport anomaly at the ordering transition for adatoms on graphene

We analyze a manifestation of the partial ordering transition of adatoms on graphene in resistivity measurements. We find that Kekule mosaic ordering of adatoms increases sheet resistance of graphene, due to a gap opening in its spectrum, and that critical fluctuations of the order parameter lead to a non-monotonic temperature dependence of resistivity, with a cusp-like minimum at T=T_c.Comment: 4 pages, 1 figur

Specifics of the Fuel and Energy Complex Regulation: Seeking New Opportunities for Russian and International Aspects

The goal of this article is to define the main trends and possible ways of further development of the fuel and energy complex (FEC) in the Russian economy. The following tasks were solved to achieve this goal: to determine the place of the Russian FEC in the world economy, to assess the results achieved in implementing the energy strategy, and to identify promising directions for regulating the Russian FEC. The results of the study allow to conclude that certain positive indicators were achieved in the field of improving energy security, reducing energy intensity and increasing the budgetary efficiency of the FEC as part of the ES-2030 implementation. At the moment, the regulatory and legal framework has been formed and is being further developed, measures for import substitution in the FEC sectors are being taken, tax, customs and tariff policies are being improved, measures have been developed and implemented to increase the availability of energy infrastructure, etc. Further measures of state regulation of the FEC sectors should be aimed at the development of renewable energy economy, measures to encourage investments in the FEC, and the improvement of the system of tariff setting for electricity transmission services. Keywords: energy security, energy conservation, renewable energy sources (RES). JEL Classifications: L70, P20, P2

(Strange) Meson Interferometry at RHIC

We make predictions for the kaon interferometry measurements in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). A first order phase transition from a thermalized Quark-Gluon-Plasma (QGP) to a gas of hadrons is assumed for the transport calculations. The fraction of kaons that are directly emitted from the phase boundary is considerably enhanced at large transverse momenta K_T ~ 1 GeV/c. In this kinematic region, the sensitivity of the R_out/R_side ratio to the QGP-properties is enlarged. Here, the results of the 1-dimensional correlation analysis are presented. The extracted interferometry radii, depending on $K_T$, are not unusually large and are strongly affected by momentum resolution effects.Comment: 8 pages, 6 figure

Ice winter roads and crossings work evaluation in the regions of the Far North

This article evaluates the work of ice winter roads and ice crossings on the roads of the Far North. An analysis is made of the transport and performance characteristics of seasonal routes and their impact on the transport network and socio-economic development of the Republic of Sakha (Yakutia). Limiting development factors and priority areas for improving the transport network of the Republic of Sakha (Yakutia) and the transport hub of the Arctic zone of the Far Eastern Federal District is identified, which is a strategically important issue in making managerial and geopolitical decisions. The purpose of the study of seasonal traffic routes on roads is to form a database for the subsequent increase in transport accessibility in the regions of the Far North and the formation of a stable, ensuring uninterrupted transport connection in the transport hub of the Arctic zone of the Far Eastern Federal District. The transport link will make it possible to freely pass traffic flows on sections of roads with seasonal communication routes with minimal transport and time costs. The objectives of this study are to assess the operation of ice winter roads and crossings, identify constraints to development and identify priority areas for the development of the transport network. The road network of the Republic of Sakha (Yakutia) is the central transport hub in the Arctic zone of the Far Eastern Federal District with access to neighboring regions (Krasnoyarsk Territory, Irkutsk Region, Amur Region, Magadan Region, Chukotka Autonomous Okrug) through which transit freight and passenger transportation are carried out. The uninterrupted functioning of traffic flows both within the republic and transit flows of neighboring entities in the republic is limited in the off-season, due to seasonal routes of communication. During transitional periods, the movement of vehicles is suspended on approximately 70 % of the roads of the republic. The considered options for the development of the transport network of the Republic of Sakha (Yakutia) and the transport hub of the Far Eastern Federal District should take into account the seasonality of transport links and the specifics of the region. The targets specified in the Strategy for the Development of the Arctic Zone of the Russian Federation and Ensuring National Security until 2035, taking into account the specifics of the region, will achieve the development of trunk and transit roads in the Arctic zone of the Far Eastern Federal District and the Russian Federation as a whole

Operational Control of the Feed of the Harvester

Comparison of normative and actual indicators on mining testifies to inefficient work of the excavating equipment. The results of the correlation analysis of the speed of movement of the harvester relative to the section of the support with the readings of methane sensors revealed a significant dependence. When conducting mining operations in complex geological conditions at great depths, a joint step-by-step carrying out of various technological processes is required to ensure the preparation, opening and excavation of reserves and the creation of safe conditions for mining coal seams. At the same time, efforts should be made to minimize time, human and energy resources. In this regard, of particular importance is the right choice of the program of operational management of technological processes of mining, monitoring the implementation of technological operations for the timely detection of deviations from the selected mode, adjustment of the established current modes of operation of technological processes and the development, if necessary, measures aimed at reducing the risks of accidents. A promising direction of solving this problem is the use of modeling methods. The developed models of technological processes of the mining enterprise will allow planning production and supporting decision-making in the implementation of operational management

Modelling Of Coal Transportation Technological Processes at Excavation

For efficient operation of a mining enterprise, the decisive role belongs to excavation areas forming volume of production and providing stability of support services. Taken engineering solutions to ensure permissible concentration of methane within working area depends on the nature of methane release (wall face, enclosing rocks, gob area, brokendown coal). Gas drainage operations from a working seam do not always provide reduction in methane emission to the required values and in these cases, effective and stable operation of an enterprise could be provided by the work of a shearer with an intensity that takes into account methane content in the developed seam, method of the working area preparation, ventilation scheme and vehicles characteristics. That is why modeling of broken-down coal transportation from the face, in order to determine the emitted methane, is an is an urgent task. The paper reviews issues of a mathematical model creation for coal transportation technological processes from the excavation area at the mine ‘Polysaevskaya’, JSC ‘SUEKKuzbass’

Consideration of the Influence of Local Road Network Condition on the Social, Economic and Industrial Development of Ulus, the Republic of Sakha (Yakutia)

На основе существующих в настоящее время методов оптимизации дорожной сети выявлено, что в условиях Якутии не всегда надежно может быть определена техническая категория дороги и строительство дорог с твердым покрытием. В условиях Якутии при проектировании местной дорожной сети предлагаем учитывать качество жизни населения считать главным критерием. Обоснована необходимость строительства дорог с твердым покрытием с учетом природно-климатических факторов, предложена система критериев, которая определяла бы социально равноправное развитие территорий при помощи местной дорожной сети.On the basis of currently available methods for optimizing the road network it has been revealed that in the conditions of Yakutia the technical category of the road and construction of paved roads can not be always reliably determined. Under the conditions of Yakutia it is proposed to use the population quality of life as the main criterion while developing the design of the local road network. The necessity of the construction of paved roads, taking into account the climatic factors has been justified. And also we have proposed a system of criteria that would define the social and equitable regional development with the help of the local road networ