A new mathematical model of the relationship between gas desorption index of drill cuttings and gas content

2014 ◽  
pp. 907-910
Author(s):  
K Shen ◽  
H Zhou
Keyword(s):  
Mathematical Model ◽  
Gas Content ◽  
Drill Cuttings ◽  
Gas Desorption ◽  
The Relationship

scholarly journals The Relationship between Mining-Induced Stress and Coal Gas under an Optimized Support Scheme: A Case Study in the Guanyinshan Coal Mine, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Tianjun Zhang ◽  
Jiaokun Wu ◽  
Yong Chen ◽  
Hong Ding ◽  
Hongyu Ma ◽  
...  
Keyword(s):  
Gas Pressure ◽  
Gas Content ◽  
Rock Support ◽  
Drill Cuttings ◽  
Coal Gas ◽  
Gas Desorption ◽  
Induced Stress ◽  
Coal And Gas Outbursts ◽  
Residual Gas ◽  
The Relationship

Stress is one of the main factors influencing coal and gas outbursts. The apparent effects of the crustal stress, the structural stress, and the mining-induced stress increase as the depth of mining increases. At present, there have been few studies of the relationship between the comprehensive analyses of the crustal stress, mining-induced stress, and coal gas. The in situ measurement of the relationship between stress-related behaviors and coal gas under the influence of mining was conducted through experimental analysis of surrounding rock support and coal and gas outburst control and optimization of surrounding rock support materials and system construction. The results showed that the mining-induced stress first increased to a peak value, then gradually decreased, and tended to stabilize as the footage progresses. Stress appears at 96 m ahead due to mining; after 57 m of advancing, there is a large increase until it passes through this area. The stress in front of the working face increases linearly, and the increase range is obviously larger than that of the coal body in a certain range on both sides. The support anchoring force gradually decreased and tended to be stable after rapidly increasing to a maximum value. The deep displacement of the roof increased linearly and tended to be stable after reaching an accumulated displacement which can reach 16-28 mm. The residual gas pressure in front of mining operations decreased rapidly, and beyond 15 m on each side of the roadway, it decreased significantly. The residual gas pressure and gas content were consistent with the gas desorption index of drill cuttings due to the influences of gas predrainage and mining. The stress along the direction of the roadway and the residual gas content, the residual gas pressure, and the gas desorption index of drill cuttings conform to the logarithmic functional relationship. The research results provide a basis for the comprehensive prevention and control of coal and gas outbursts from multiple angles considering stress, coal, and gas.

scholarly journals Experimental Study of the Characteristic Changes of Coal Resistivity during the Gas Adsorption/Desorption Process

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Zengchao Feng ◽  
Chen Wang ◽  
Dong Dong ◽  
Dong Zhao ◽  
Dong Zhou
Keyword(s):  
Gas Adsorption ◽  
Gas Content ◽  
Resistivity Change ◽  
Adsorption Experiment ◽  
Desorption Process ◽  
Continuous Adsorption ◽  
Gas Desorption ◽  
Original Figure ◽  
Adsorption Desorption ◽  
The Relationship

To study the influence of gas adsorption-desorption on the resistivity of coal, the resistivity changes in conditions of continuous adsorption/desorption and isovolumetric adsorption/desorption were tested by high-precision resistance measurement, and the relationship between coal resistivity and gas content was investigated. The results show that gas adsorption/desorption has obvious effects on the resistivity of coal. Similar behavior was observed both in continuous adsorption/desorption and in isovolumetric adsorption/desorption experiments. The coal resistivity decreased gradually at the very beginning and then tended to stabilize as the gas adsorption capacity increased; in the process of gas desorption, the resistivity demonstrated a linear relationship with gas content. When comparing resistivities for the different adsorption modes, it was found that, for the same gas content in each mode, the resistivity change in the isovolumetric adsorption experiment was more obvious than in the continuous adsorption experiment. Also, the coal resistivity in the isovolumetric experiment differed further from the original figure when the desorption ended. The results are significant for predicting gas content in the coal mining process.

A New Coal Sampling System for Measurement of Gas Content in Soft Coal Seams

2011 ◽  
Vol 121-126 ◽  
pp. 2459-2464 ◽  
Author(s):  
S. Xue ◽  
Xing S. Li ◽  
J. Xie
Keyword(s):  
Field Test ◽  
Gas Content ◽  
Coal Seams ◽  
Borehole Stability ◽  
Sampling System ◽  
Drill Cuttings ◽  
Core Samples ◽  
Soft Coal ◽  
Gas Desorption ◽  
Direct Measurements

Core samples or drill cuttings from boreholes drilled in coal seams are used in direct measurements of gas content in coal. In soft coal seams, core samples are difficult or sometimes impossible to obtain due to poor borehole stability such as large borehole deformation and borehole collapse, drill cuttings have to be taken and used. Due to their faster initial gas desorption rates, drill cuttings need to be taken rapidly and accurately at given positions during borehole drilling to ensure the accuracy of gas content measurements. To meet these sampling requirements of drill cuttings, a new sampling-while-drilling (SWD) system has been developed. The SWD system is based on a special design of double-tubing drill rods and a reversed circulation of pressurized air. A field test of the SWD system was carried out with satisfactory results. This paper presents the principle and results of the field test of the SWD system.

Temperature Influence on Performance of Oxidation Ponds

1991 ◽  
Vol 24 (5) ◽  
pp. 85-96 ◽  
Author(s):  
Qingliang Zhao ◽  
Zijie Zhang
Keyword(s):  
Mathematical Model ◽  
Temperature Influence ◽  
Field Scale ◽  
Experiment Data ◽  
Computer Technique ◽  
Oxidation Pond ◽  
Optimum Model ◽  
Oxidation Ponds ◽  
The Mathematical Model ◽  
The Relationship

By means of simulated tests of a laboratory–scale oxidation pond model, the relationship between BOD5 and temperature fluctuation was researched. Mathematical modelling for the pond's performance and K1determination were systematically described. The calculation of T–K1–CeCe/Ci) was complex but the problem was solved by utilizing computer technique in the paper, and the mathematical model which could best simulate experiment data was developed. On the basis of experiment results,the concept of plug–ratio–coefficient is also presented. Finally the optimum model recommended here was verified with the field–scale pond data.

Pulse-Width Modulated Amplifier for DC Servo System and Its Matlab Simulation

2015 ◽  
Vol 9 (1) ◽  
pp. 625-631
Author(s):  
Ma Xiaocheng ◽  
Zhang Haotian ◽  
Cheng Yiqing ◽  
Zhu Lina ◽  
Wu Dan
Keyword(s):  
Mathematical Model ◽  
Transfer Function ◽  
Input Signal ◽  
Pulse Width ◽  
Rotation Speed ◽  
Servo Motor ◽  
Matlab Simulation ◽  
Pulse Width Modulated ◽  
Signal Changes ◽  
The Relationship

This paper introduces a mathematical model for Pulse-Width Modulated Amplifier for DC Servo Motor. The relationship between pulse-width modulated (PWM) signal and reference rotation speed is specified, and a general model of motor represented by transfer function is also put forward. When the input signal changes, the rotation speed of the servo motor will change accordingly. By changing zeros and poles, transient performance of this system is discussed in detail, and optimal ranges of the parameters is recommended at the end of discussion.

Modeling the Growth of Salmonella in Cut Red Round Tomatoes as a Function of Temperature

2010 ◽  
Vol 73 (8) ◽  
pp. 1502-1505 ◽  
Author(s):  
WENJING PAN ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Mathematical Model ◽  
Growth Rates ◽  
Low Temperatures ◽  
Safety Concern ◽  
Time Intervals ◽  
Salmonella Serotypes ◽  
Increasing Temperature ◽  
Incubation Temperatures ◽  
Raw Poultry ◽  
The Relationship

Tomato-associated Salmonella outbreaks have recently become a significant food safety concern. Temperature abuse of cut tomatoes may have played a role in some of these outbreaks. The purpose of this study was to develop a mathematical model to describe the growth of Salmonella on cut tomatoes at various temperatures. Four Salmonella serotypes (Typhimurium, Newport, Javiana, and Braenderup) obtained from previous tomato-linked cases of salmonellosis were used in this study. These four serotypes were cultured separately, combined into a cocktail, and inoculated onto whole red round tomatoes and allowed to dry overnight. The tomatoes were then cut into pieces and incubated at a predetermined range of temperatures (10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, and 35°C). Salmonella concentration was measured at specified time intervals to determine the growth curve for Salmonella on cut tomatoes at each temperature. The growth rates were calculated using DMFit and used to build a mathematical model to illustrate the relationship between the growth rates of Salmonella on tomatoes and incubation temperatures from 10 to 35°C. The resulting model compared favorably with a Salmonella growth model for raw poultry developed by our laboratory. The Pathogen Modeling Program underpredicted growth at low temperatures and overpredicted growth at high temperatures. ComBase predicted consistently slower growth rates than were observed in tomatoes but showed parallel increases in growth rate with increasing temperature.

scholarly journals THE INNOVATIVE POTENTIAL OF HUMAN RESOURCES AS A FACTOR IN THE DEVELOPMENT OF THE INNOVATIVE TECHNOLOGIES MARKET IN UKRAINE

2021 ◽  
Vol 23 (1(78)) ◽  
pp. 58-74
Author(s):  
I.V. GRYSHCHENKO ◽  
V.F. GRYSHCHENKO
Keyword(s):  
Mathematical Model ◽  
Human Resources ◽  
Market Development ◽  
Short Term ◽  
Model Calculations ◽  
Innovative Technologies ◽  
Innovation Capacity ◽  
Innovative Potential ◽  
The Impact ◽  
The Relationship

Topicality. The successful operation of an economic entity, in the development of the innovative technologies market, is largely determined by the innovative potential of its human resources - by the people who work for it - their knowledge, talents, and skills. The wrong combination of these elements, lack of employees who have the necessary qualifications, lack of harmony in the relationship between employers and employees can inevitably lead to serious financial and economic problems. Improving the efficiency of the use of the innovative potential of human resources in the development of the innovative technologies market is one of the most urgent tasks for any business entity. The competitive advantages of business entities, financial and economic indicators of their activity, ensuring sustainable development of entrepreneurship in general, are depending on the degree and balance of its use. Aim and tasks. The purpose of the work is to analyze and develop on its basis recommendations for increasing the level of the innovative potential of human resources in the context of the development of the innovative technologies market in Ukraine. Research results. The article analyzes the main structural elements of the innovative potential of human resources and identifies the factors influencing its level in Ukraine. The results of the analysis allowed us to build an economic and mathematical model of the relationship between innovation capacity, as an indicator of the development of the innovative technologies market and components of the innovative potential of human resources in Ukraine. This made it possible to predict the level of innovation capacity as an indicator of the innovative technologies market development in Ukraine in the short term. The obtained results allowed us to identify problems and develop recommendations for increasing the level of the innovative potential of human resources in the context of the innovative technologies market development in Ukraine. Conclusion. Based on the developed economic and mathematical model, calculations were made that characterize the relationship between innovation capacity as an indicator of the innovative technologies market development and components of the innovative potential of human resources in Ukraine. As shown in the calculations, the proposed economic and mathematical model with high accuracy allows to assess the impact of components of the innovative potential of human resources on innovation capacity and identify major obstacles for its development, which made it possible to predict trends in innovation capacity as an indicator of the innovative technologies market development in Ukraine in the short term.

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