scholarly journals Innovative transformations of a model for flow distribution in gas systems and their new properties

2019 ◽  
Vol 102 ◽  
pp. 02004
Author(s):  
Nikolay I. Ilkevich ◽  
Tatyana.V. Dzyubina ◽  
Zhanna.V. Kalinina
Keyword(s):  
Network Analysis ◽  
Flow Distribution ◽  
Supply System ◽  
Distribution Model ◽  
Gas Flows ◽  
Modern Development ◽  
Gas System ◽  
Gas Supply

The methods of network analysis are widely used in mathematical modelling of optimal gas flows to solve the problems of long-term planning and development of gas systems. However, the modern development of gas systems, their renovation and modernization require that the new trends in innovative transformation should be taken into account in the mathematical models for their research as well. This paper is focused on the proposals for considering the new properties of gas system in the mathematical flow distribution model as compared to the traditional formulation. Case study involves the calculation of gas flows for an aggregated unified gas supply system for the period up to 2030. This calculation allows for the edge coefficients and a gain in the transmission capacities of the edges.

scholarly journals Transformation of a mathematical model of gas flow distribution to solve the problems of gas supply system development

2020 ◽  
Vol 219 ◽  
pp. 02001
Author(s):  
Nikolay Ilkevich ◽  
Tatyana Dzyubina ◽  
Zhanna Kalinina
Keyword(s):  
Mathematical Model ◽  
Gas Flow ◽  
System Development ◽  
Flow Distribution ◽  
Supply System ◽  
Economic Environment ◽  
Gas Flows ◽  
Supply Systems ◽  
New Criteria ◽  
Gas Supply

This paper proposes taking into account new properties of gas supply systems in a mathematical model of flow distribution in comparison with the traditional formulation. The approach suggests introducing an arc coefficient, which allows for changes in the magnitude of gas flow passing along the arc, a vector of an increase in the arc throughput, and lower constraints on the gas flow along the arc. We also propose considering a new economic environment, namely, new criteria for optimizing the flow distribution and setting fictitious gas prices for consumers. These criteria enable us to take account of the priority gas supply to a definite group of consumers. As an example, the calculation of gas flows for the aggregated Unified Gas Supply System (UGSS) for 2030 is considered. This calculation takes into account the arc coefficients and the increase in the throughput of arcs.

scholarly journals Mining disposal erosion evaluation: A case study

2021 ◽  
Vol 882 (1) ◽  
pp. 012050
Author(s):  
Y S Novianti ◽  
U Saismana ◽  
Y Yuhanes ◽  
H N Fikri
Keyword(s):  
Land Cover ◽  
Soil Loss ◽  
Flow Distribution ◽  
Mining Activity ◽  
Distribution Model ◽  
Mining Activities ◽  
The Third ◽  
Soil Loss Equation ◽  
Reclamation Process

Abstract Mining disposal (dumping overburden) area is the primary consideration in the reclamation process in mining activities, especially in mining activity. The current study aims to determine the rate of erosion and the level of erosion hazard at mine disposal using water flow distribution. This research was conducted in a coal mine in Kalimantan. Based on the structure of the runoff flow distribution model, this study divides disposal into three land units. The universal soil loss equation in three land units was obtained for erosion values. The value for each land unit is 76 tons/ha/year, 134 tons/ha/year, and 50 tons/ha/year. These three land units are under the level of moderate and light danger of erosion. Afterward, three recommendations were made to the three land units. The first recommendation is the condition of land cover does not change, and conservation changes; the second recommendation is with changes in land cover, but conservation does not change; and the third recommendation is with conditions of land cover and conservation change. The second recommendation shows the best results compared to the other recommendations.

Failure Analysis and Transformation of Hydrogen Compressor Dry Gas Seal

2013 ◽  
Vol 331 ◽  
pp. 98-101 ◽  
Author(s):  
Hui Cao ◽  
Yan Liu ◽  
Chang Ji Lin
Keyword(s):  
Labyrinth Seal ◽  
Supply System ◽  
Gas Oil ◽  
Dry Gas Seal ◽  
Term Operation ◽  
The Core ◽  
Coker Gas Oil ◽  
Tandem Structure ◽  
Gas Supply

Recycle hydrogen compressor group is the core equipment of heavy coker gas oil hydrotreater unit of refinery. This compressor adopts tandem structure with intermediate labyrinth seal as its dry gas seal type. The compressor dry gas seal has officially been put into operation for six months, it damaged twice and caused the device to unplanned shutdown, seriously affected the long term operation of the device. During research and analysis on the seal of the unit, a series of problems were found, such as gas anti-channeling, sealing gas with oil etc. After transformation on the sealed gas supply system, the compressor achieved the purpose of long term stable running.

Caregivers' Perceptions of Speech-Language Pathologist Talk About Child Language and Literacy Disorders

2020 ◽  
Vol 29 (4) ◽  
pp. 2049-2067
Author(s):  
Karmen L. Porter ◽  
Janna B. Oetting ◽  
Loretta Pecchioni
Keyword(s):  
Language And Literacy ◽  
Collective Case Study ◽  
Study Approach ◽  
School Aged Children ◽  
Speech Language Pathologist ◽  
Therapy Goals ◽  
Semistructured Interviews ◽  
Types Of Information

Purpose This study examined caregiver perceptions of their child's language and literacy disorder as influenced by communications with their speech-language pathologist. Method The participants were 12 caregivers of 10 school-aged children with language and literacy disorders. Employing qualitative methods, a collective case study approach was utilized in which the caregiver(s) of each child represented one case. The data came from semistructured interviews, codes emerged directly from the caregivers' responses during the interviews, and multiple coding passes using ATLAS.ti software were made until themes were evident. These themes were then further validated by conducting clinical file reviews and follow-up interviews with the caregivers. Results Caregivers' comments focused on the types of information received or not received, as well as the clarity of the information. This included information regarding their child's diagnosis, the long-term consequences of their child's disorder, and the connection between language and reading. Although caregivers were adept at describing their child's difficulties and therapy goals/objectives, their comments indicated that they struggled to understand their child's disorder in a way that was meaningful to them and their child. Conclusions The findings showed the value caregivers place on receiving clear and timely diagnostic information, as well as the complexity associated with caregivers' understanding of language and literacy disorders. The findings are discussed in terms of changes that could be made in clinical practice to better support children with language and literacy disorders and their families.

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