scholarly journals Precision of determination of thawing depth of the frozen rocks

2021 ◽  
Vol 2131 (5) ◽  
pp. 052079
Author(s):  
A Galkin ◽  
V Pankov
Keyword(s):  
Melting Temperature ◽  
Functional Dependence ◽  
Underground Structures ◽  
Simple Assumption ◽  
Forecast Precision ◽  
Thawing Depth ◽  
Ice Content ◽  
Analytical Relations ◽  
Technical Solutions

Abstract An important quantity determining the choice of technical solutions in design of both surface and underground structures in the permafrost area is the thawing depth of the rocks. To obtain simple analytical relations to determine the thawing depth over time, a simple assumption is used: that the initial temperature of the rocks is equal to the melting temperature of ice. The aim of the present work was the assessment of impact of this assumption on the forecast precision. For a quantitative assessment, a simple typical formula recommended by construction norms was used. Functional dependence of the density of the rocks and their heat capacity on the fraction of ice content was considered in the formulas. A rock consisting of a combination of quartz sand and ice was used as an example.Multiple variant calculations were done according to the formulas and their results presented in the form of charts. It was shown that the relative error in determination of thawing depth depends solely on the Stefan criterion and is independent of the thawing duration, thermal conductivity coefficient of the thawing rocks and the air temperature during the thawing. A relation was obtained which allows to quickly assess at which initial values (temperature and ice content of the frozen rocks) it is possible to use the formulas obtained from the simplified calculation models with the assumption that the temperature of the rocks is equal to the melting temperature of ice.

scholarly journals RESEARCH INTO THE METHODS OF ANALYSING THE PRODUCTIVITY INDICATORS OF TRANSPORT TERMINALS

Transport ◽  
2009 ◽  
Vol 24 (3) ◽  
pp. 192-199 ◽  
Author(s):  
Ilona Jaržemskienė
Keyword(s):  
Comparative Analysis ◽  
Functional Dependence ◽  
Data Envelopment ◽  
Analysis Method ◽  
Accurate Evaluation ◽  
Feasible Alternative ◽  
Productivity Indicators ◽  
Insight Into ◽  
Regressive Analysis

The measurement of terminal productivity is the issue of extreme importance to both terminal owners and management and customers. As the sector of transport is highly intensive in terms of investments into the infrastructure, the productivity of a terminal may play a crucial role in competing with other terminals. Productivity is defined in terms of inputs and output. The majority of the available studies, wherein this issue is addressed, are generally focused on the determination of functional dependence between inputs and output using the method of regressive analysis. The present article provides an insight into the Data Envelopment Analysis method as a tool for measuring productivity. This technique enables a rather accurate evaluation of terminal productivity by means of comparative analysis, which, in fact, appears to be the only feasible alternative in cases where statistic data required for performing regressive analysis is lacking.

Determination of global kinetic parameters by optimization procedure using burning velocity measurements

2018 ◽  
Vol 13 (6) ◽  
pp. 50
Author(s):  
Gleb V. Grenkin ◽  
Alexander Yu. Chebotarev ◽  
Valeri I. Babushok ◽  
Sergey S. Minaev
Keyword(s):  
Kinetic Parameters ◽  
Equivalence Ratio ◽  
Reaction Rate ◽  
Functional Dependence ◽  
Burning Velocity ◽  
Optimization Procedure ◽  
Optimal Parameters ◽  
Velocity Measurements ◽  
Equilibrium Calculations

The optimization procedure was developed to derive the global kinetic parameters using experimental dependence of burning velocity on the equivalence ratio. The simple model of laminar premixed flame propagation with assumed constant parameters was used to demonstrate the features of the suggested procedure. The suggested method allows finding optimal parameters for the defined functional dependence of the reaction rate on the temperature and reactant concentrations. The dependence of combustion adiabatic temperature on equivalence ratio is assumed to be known from the flame equilibrium calculations. The global kinetic parameters of combustion reaction were determined for methane, ethylene and propane mixtures with air on the basis of experimental data on burning velocity as function of the equivalence ratio. The calculated overall kinetic parameters are compared with parameters obtained by other methods within similar global model.

scholarly journals Investigation of Borosilicate Glasses with Simulated HLW Components and Determination of Their Chemical Durability

2021 ◽  
Vol 8 (1) ◽  
pp. 20218105
Author(s):  
S. M. Shaydullin ◽  
E. A. Belanova ◽  
P. V. Kozlov ◽  
M. B. Remizov ◽  
E. M. Dvoryanchikova
Keyword(s):  
Chemical Durability ◽  
Current Status ◽  
Borosilicate Glasses ◽  
Radiochemical Plant ◽  
Technical Solutions

The paper discusses the current status of the HLW vitrification technology applied at the radiochemical plant of the Mayak PA. Conceptual and technical solutions proposed to develop the technology of vitrification of various types of liquid HLW at the Mayak PA are presented. Compositions of borosilicate glasses with HLW components are described, temperatures of their melting and easy pouring are determined. Chemical durability parameters obtained for the borosilicate glasses are provided.

The Gallium Melting-Point Standard: A Determination of the Liquid—Solid Equilibrium Temperature of Pure Gallium on the International Practical Temperature Scale of 1968

1977 ◽  
Vol 23 (4) ◽  
pp. 719-724 ◽  
Author(s):  
Donald D Thornton
Keyword(s):  
Melting Point ◽  
Melting Temperature ◽  
Temperature Scale ◽  
Equilibrium Temperature ◽  
Melting Range ◽  
Practical Temperature ◽  
Practical Temperature Scale ◽  
Gallium Melting Point

Abstract The sharpness and reproducibility of the gallium melting point were studied, and the melting temperature of gallium in terms of IPTS-68 was determined. Small melting-point cells designed for use with thermistors are described. Nine gallium cells including three levels of purity were used in 68 separate determinations of the melting point. The melting point of 99.99999% pure gallium in terms of IPTS-68 is found to be 29.7714 ± 0.0014 °C; the melting range is less than 0.0005 °C and is reproducible to ±0.0004 °C.

scholarly journals Studies on the Sequence Distributions of Microbial Polyester by NMR and Determination of Melting Temperature.

2002 ◽  
Vol 58 (3) ◽  
pp. 98-105 ◽  
Author(s):  
Wen-chuan Hsieh ◽  
Kimihiko Nishiwaki ◽  
Nobuyuki Tanaka ◽  
Hiroshi Mitomo
Keyword(s):  
Melting Temperature ◽  
Sequence Distributions

scholarly journals Regression model of the influence of the height of drum mixer blades on the quality of mixture

2020 ◽  
Vol 175 ◽  
pp. 05047
Author(s):  
Konstantin Fudin ◽  
Vladimir Konovalov ◽  
Vladimir Zaitsev ◽  
Vyacheslav Teryushkov
Keyword(s):  
Coefficient Of Variation ◽  
Experimental Error ◽  
Functional Dependence ◽  
Mixing Time ◽  
Computer Processing ◽  
Fourth Level ◽  
Drum Mixer ◽  
Design Factors

The aim of the research was to establish the influence of the number and height of blades of a drum mixer on the quality of the prepared mixture of concentrated feed. The research method of the drum mixer provided for the experimental determination of the coefficient of variation (unevenness) of the mixture with a three-level combination of the blades height and their number. The absence of an extremum according to the obtained data required the use of a fourth level of the number of blades. Computer processing of the results made it possible to establish a functional dependence of the influence of design factors on the quality of the mixture. The implementation of the used research methodology for the operation of the drum mixer made it possible to establish an adequate functional dependence of the influence of the number of blades and their height on the quality of the mixture. The number of blades used practically does not affect the coefficient of variation of the content of the control component. The values change less than experimental error. However, existing trends indicate a slight (about 1%) decrease in the coefficient of variation of the mixture with an increase in the number of blades from 2 to 8 pcs. For 50 kg of feed in a drum capacity of 0.26 m3, the height of the blades is about 0.15 m. The increase or decrease in the height to 0.125 m or 0.175 m affects the quality of the mixture, increasing the coefficient of variation from 20.6% to 34-50% at the proportion of the control component of 1% and the mixing time of 200 seconds.

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