scholarly journals Mathematical Models of Unsteady Flow Distribution in Gas Transport Systems * *Supported by the Program of Russian Foundation for Basic Research 15-08-08698.

2017 ◽  
Vol 112 ◽  
pp. 1160-1167 ◽  
Author(s):  
Atlas V. Akhmetzyanov ◽  
Anton M. Salnikov
Keyword(s):  
Unsteady Flow ◽  
Mathematical Models ◽  
Gas Transport ◽  
Flow Distribution ◽  
Basic Research ◽  
Transport Systems

Liposomes with cerasome-forming lipids as gene therapy vectors

2021 ◽  
Author(s):  
Moataz Dowaidar
Keyword(s):  
Electrostatic Interactions ◽  
Membrane Surface ◽  
Immunological Response ◽  
Basic Research ◽  
Systemic Circulation ◽  
Cationic Lipids ◽  
Transport Systems ◽  
Component Selection ◽  
Polar Groups ◽  
Gene Therapy Vectors

Basic research focuses on liposome transport systems as non-viral ways of transferring genetic and therapeutic substances. Due to electrostatic interactions between positive polar groups of cationic lipids and the negatively charged cell membrane surface, nucleic acids may readily be transported into cells as part of lipoplexes. Cationic liposomes, however, have a number of well-known problems, including low stability, toxicity, and a potential for severe immunological response. Recent research has revealed, however, that by increasing the system with additional components such as cerasome-forming lipids, these problems may be solved. They aid in the prolongation of the release of a beneficial liposome load in cells by increasing vesicle stability in the systemic circulation. This circumstance broadens the applications for liposomal systems. As a consequence, using varied lipids can create numerous liposomes for use in a range of medical fields. Nonviral delivery approaches based on hybrid liposomes with suitable structural component selection may be a possible response to a number of medical concerns, and further study is urgently needed.

Kinetics and Mechanism of Gallium Arsenide Growth in Gas-Transport Systems

1986 ◽  
pp. 34-45
Author(s):  
L. G. Lavrentyeva ◽  
I. V. Ivonin ◽  
L. P. Porokhovnichenko
Keyword(s):  
Gallium Arsenide ◽  
Gas Transport ◽  
Kinetics And Mechanism ◽  
Transport Systems

Method for calculation of flow distribution in a gas transport system

1992 ◽  
Vol 60 (1) ◽  
pp. 1322-1325
Author(s):  
N. Yu. Medvedeva ◽  
V. A. Shaldyrvan
Keyword(s):  
Transport System ◽  
Gas Transport ◽  
Flow Distribution

scholarly journals Forecasting rational working modes of long-operated gas-transport systems under conditions of their incomplete loading

2021 ◽  
Vol 4 (8(112)) ◽  
pp. 6-15
Author(s):  
Volodymyr Grudz ◽  
Yaroslav Grudz ◽  
Myroslav Iakymiv ◽  
Mykola Iakymiv ◽  
Pavlo Iagoda
Keyword(s):  
Mathematical Modeling ◽  
Energy Consumption ◽  
Transport System ◽  
Gas Transport ◽  
Pressure Fluctuations ◽  
Initial Pressure ◽  
High Amplitude ◽  
Nonstationary Process ◽  
Optimality Criteria ◽  
Transport Systems

Prolonged operation of the gas-transport system in conditions of partial loading involves frequent changes in the volume of gas transportation, which necessitates prompt forecasting of system operation. When forecasting the modes of operation of the gas transport system, the main criterion of optimality implies the maximum volume of gas pumping. After all, in this case, the largest profit of the gas-transport company is achieved under the condition of full provision of consumers with energy. In conditions of incomplete loading of the gas-transport system caused by a shortage of gas supply, optimality criteria change significantly. First, the equipment is operated in ranges far from nominal ones which leads to growth of energy consumption. Secondly, changes in performance cause high-amplitude pressure fluctuations at the outlet of compressor stations. Based on mathematical modeling of nonstationary processes, amplitude and frequency of pressure fluctuations at the outlet of compressor stations which can cause the pipeline overload have been established. To prevent this, it was proposed to reduce initial pressure relative to the maximum one. Calculated dependence was obtained which connects the amplitude of pressure fluctuations with the characteristics of the gas pipeline and the nonstationary process. Reduction in energy consumption for transportation is due to the shutdown of individual compressor stations (CS). Mathematical modeling has made it possible to establish regularities of reduction of productivity of the gas-transport system and duration of the nonstationary process depending on the location of the compressor station on the route. With an increase in the number of shutdown compression stations, the degree of productivity decrease and duration of nonstationarity reduces The established patterns and proposed solutions will improve the reliability of a gas-transport system by preventing pipeline overload and reduce the cost of gas transportation by selecting running numbers of shutdown stations with a known decrease in productivity.

scholarly journals Analytical models of decision-making theory in digital transport logistics

2021 ◽  
Vol 2061 (1) ◽  
pp. 012129
Author(s):  
A Terentyev ◽  
M Karelina ◽  
E Karelina
Keyword(s):  
Mathematical Models ◽  
Analytical Models ◽  
Transport Systems ◽  
Large Set ◽  
Mathematical Methods ◽  
Large Databases ◽  
Information And Communication ◽  
High Level ◽  
High Degree ◽  
Made In

Abstract The active introduction of information and communication (digital) technologies into the modern reality of transport systems operation requires the development of modeling methods for the creation of software that allows to do the following: determine the formal efficiency of decisions made in digital transport systems (DTS); process large volumes of DTS data; perform analysis of DTS functioning environment using artificial intelligence algorithms, analytical analogues of neural networks, etc. A digital transport system, being a complex system, is determined by a large set of formalized indicators (database) and requires finding effective solutions for a sufficiently large number of criteria or signs of effectiveness. Obtaining reliable solutions in multi-criteria information situations causes difficulties, which are objective. In most cases modern mathematical models artificially reduce multi-criteria information situations to single-criteria categories. This approach, based on the use of integral criteria, has a fundamental disadvantage - the use of integral criteria to obtain estimates of the efficiency of actions or processes in complex systems is characterized by a high level of subjectivism. In this case, the obtained solution may be acceptable, but not an objective result. Therefore, it is necessary to develop mathematical models for solving multi-criteria problems applicable to the solution of problems in complex transport systems, allowing one to operate in the environment of large databases for operational reconfiguration of a management system in conditions of uncertainty and/or possible counteraction of the external environment. The article presents the results of development of mathematical methods of modeling, which allow us to construct algorithms for solving optimization tasks, formulated as multi-criteria models and in the presence of a high degree of uncertainty in the interaction of the system with the environment.

scholarly journals DETERMINATION OF THE DELAY TIME OF THE BUS DEPARTURE FROM THE STOP POINT LOCATED NEAR A REGULATED CROSSROADS

2020 ◽  
Vol 3 (156) ◽  
pp. 35-40
Author(s):  
P. Gorbachov ◽  
O. Makarichev ◽  
O. Kolii ◽  
Y. Liubyi
Keyword(s):  
Traffic Flow ◽  
Delay Time ◽  
Regression Models ◽  
Basic Research ◽  
Transport Systems ◽  
Passenger Transportation ◽  
Flow Parameters ◽  
Object Of Study ◽  
Stop Point

The article is devoted to solving scientific and applied problems of determining the rational location of stopping points at the entrance or exit from controlled intersections. Analysis of approaches and methods to the determination of rational location of stopping points showed that they are mostly based on the goals of minimizing the time for passenger transportation or maximizing the performance of transport systems functioning. With that, the question of determining the time of delay of vehicle departure from the stopping point bottleneck after the embarkation and disembarkation of passengers is paid very little attention to. Currently, there are only regression models available that cannot claim to be universal and their use in transport planning requires similar conditions of functioning with the object, where statistic data were collected. The conducted analysis allowed determining the trend of basic research, namely, assessment of the influence of traffic flow parameters on the delay time of route transport departure from the stopping point bottleneck in the area adjacent to the controlled intersection. The process of delay occurrence at the exit of route transport from the stopping point bottleneck was formalized as the object of study thanks to which there was built an analytical model to determine the time of delay of route transport departure from the stopping point bottleneck. There were investigated two options for placement of a stopping point at the entrance and exit from the intersection. According to the results of calculations, it was determined that the delay time of route transport departure from the stopping point was influenced by many factors, whose influence varies depending on the location of the stopping point at the entrance and exit from a controlled intersection. By the results of researches one can be affirm that the most expedient is the placement of a stopping point at the minimum acceptable distance from the intersection, and it is recommended to locate a stopping point at a distance of 30 m at the entrance to the intersection. Keywords: stop, route vehicles, traffic flow, regulated intersections, traffic, latency, capacity transport areas.

General Design Study on CSR1000 Structure

2013 ◽  
Author(s):  
Hong-liang Zhang ◽  
Heng Fan ◽  
Ying Luo ◽  
Xiang Li ◽  
Xiao Liu ◽  
...  
Keyword(s):  
Design Research ◽  
Flow Distribution ◽  
Basic Research ◽  
Structure Design ◽  
Research Progress ◽  
Response Analysis ◽  
Engineering Practice ◽  
Flow Induced Vibration ◽  
General Design ◽  
Supercritical Water Cooled Reactor

Based on China Supercritical-Water-Cooled Reactor 1000 (CSR1000) research project, this paper introduces the general design research progress and the structure design scheme of the two-pass reactor, of which the key technologies are studied or proposed, including reactor structure material, sealing type, flow distribution, thermal stress analysis and flow-induced vibration response analysis. Basic research methods and solutions are provided, which are meaningful for the engineering practice.

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