scholarly journals Estimate of intrinsic safety of capacitive circuits

2019 ◽  
Vol 109 ◽  
pp. 00027
Author(s):  
Oleksandr Hladkov ◽  
Anatolii Mnukhin ◽  
Rishard Stasevich
Keyword(s):  
Coal Mine ◽  
Regression Equation ◽  
Universal Method ◽  
Discharge Time ◽  
Safety Parameters ◽  
Comparison Of The Results ◽  
Contact Closure ◽  
Intrinsic Safety

A universal method has been developed and tested for computer estimate of intrinsic safety of inductive capacitive circuits, which takes into account the most hazardous discharge type by contact closure and the regression dependences are obtained of minimal igniting energy on discharge time in a capacitive circuit and the comparison is made of results with available experimental dependences. A regression equation is received which connects minimal igniting energy and discharge time as well as voltage of a capacitive circuit. The comparison of the results with available experimental dependencies is made. The intrinsic safety parameters are defined which leads to decrease of risk for explosion and freely burning fire in a coal mine.

Explosion-Proof Design for Coal Mine Rescue Robots

2011 ◽  
Vol 211-212 ◽  
pp. 1194-1198 ◽  
Author(s):  
Yun Wang Li ◽  
Shi Rong Ge ◽  
Hua Zhu
Keyword(s):  
Coal Mine ◽  
Mobile Systems ◽  
Mine Environment ◽  
Environment Exploration ◽  
Rescue Robots ◽  
Mine Rescue ◽  
Intrinsic Safety

The explosion-proof design for coal mine robots that are used to explore environment and rescue after coal mine disaster must be adopted. In order to carry out the explosion-proof design for coal mine robots reasonably, based on the analysis of coal mine robots and their explosion-proof design, the explosion-proof types for robots are studied on. The conclusions are as follows: (1) the mixed explosion-proof design including integrated and partial explosion-proof design can be adopted in the robots design; (2) protection types for robots mainly include flameproof enclosure, pressurized enclosure, intrinsic safety, and combination of them. Based on this, the explosion-proof structures of the mobile systems of a track-type robot and a rocker-type robot for coal mine environment exploration are introduced. According to the different structure of the two robots, the concentrated and dispersed flameproof enclosures are respectively designed for the track-type robot and a rocker-type robot. This paper can provide reference for the explosion-proof design for coal mine robots.

scholarly journals MINING LAND SUBSIDENCE MONITORING USING SENTINEL-1 SAR DATA

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 655-658 ◽  
Author(s):  
W. Yuan ◽  
Q. Wang ◽  
J. Fan ◽  
H. Li
Keyword(s):  
Law Enforcement ◽  
Land Subsidence ◽  
Coal Mine ◽  
Underground Mining ◽  
Mining Area ◽  
Mine Area ◽  
Optical Images ◽  
Sar Data ◽  
Comparison Of The Results ◽  
Subsidence Monitoring

In this paper, DInSAR technique was used to monitor land subsidence in mining area. The study area was selected in the coal mine area located in Yuanbaoshan District, Chifeng City, and Sentinel-1 data were used to carry out DInSAR techniqu. We analyzed the interferometric results by Sentinel-1 data from December 2015 to May 2016. Through the comparison of the results of DInSAR technique and the location of the mine on the optical images, it is shown that DInSAR technique can be used to effectively monitor the land subsidence caused by underground mining, and it is an effective tool for law enforcement of over-mining.

Studies of Fibrinogen Metabolism in Healthy and Hypertensive Female Subjects with the Use of Autologous I-125-Fibrinogen

1978 ◽  
Vol 39 (01) ◽  
pp. 039-045 ◽  
Author(s):  
Y Takeda ◽  
T Takeuchi
Keyword(s):  
Steady State ◽  
Regression Equation ◽  
Plasma Fibrinogen ◽  
Synthesis Rate ◽  
Fibrinogen Concentration ◽  
Catabolic Rate ◽  
Healthy Female ◽  
Altered Metabolism ◽  
Comparison Of The Results ◽  
Female Subjects

Summary10 healthy female subjects and 15 female patients with essential hypertension were studied with respect to fibrinogen metabolism in a steady state. Autologous I-125-labeled fibrinogen (I-125-fibrinogen) was used as a tracer. Comparison of the results showed that plasma volume, t½ of plasma I-125-fibrinogen and fractional catabolic rate (j3p) of plasma fibrinogen were not appreciably different in both groups of subjects, but plasma fibrinogen concentration, and catabolic flux of (synthesis rate) were significantly higher in hypertensive subjects, whereas extravascular fibrinogen and fractional transcapillary transfer rate (j1) of were significantly decreased in the patients. Further analyses of the data in both groups showed that there were significant correlations between diastolic blood pressure (P) and j1 with a regression equation of j1 = e−0.0285P, between 1 and between and j1 with a regression equation of 1. These results indicate that the observed decrease of j1 triggered the transition from normal to pathological steady state and is responsible for the altered metabolism and distribution of fibrinogen in hypertensive subjects.

Experimental Study on the Compression Rebound Modulus of Coal Gangue Mixture

2012 ◽  
Vol 608-609 ◽  
pp. 1759-1763
Author(s):  
Xian Hai Xu ◽  
Ya Peng Zhang ◽  
Zhi Fei Zhang ◽  
Ju Jun Zhang
Keyword(s):  
Experimental Study ◽  
Regression Analysis ◽  
Fly Ash ◽  
Coal Mine ◽  
Uniform Design ◽  
Regression Equation ◽  
Coal Gangue ◽  
Analysis Model ◽  
Mix Proportion ◽  
Cement Mixture

This experiment was designed by making a coal gangue with coal gangue, fly ash, lime power and a small amount of cement mixture selected from Dongpang coal mine in Hanxing area.We tested the compressive rebound modulus strength of the mixture, and according to the method of uniform design, 8 groups mix ratio were designed and the experiments on the coal gangue mixture in various mix proportion have been conducted. The experimental results were analyzed by regression analysis model, and the regression equation between the compression rebound modulus of coal gangue mixture and the blending amount of each admixture was established. Finally, using this regression analysis model, the influence of the fly ash, calces, cement to strength on the compression rebound modulus of coal gangue mixture was analyzed.

Design and Study on Intrinsically Safe Circuit of Portable Infrared Methane Alarming Device

2011 ◽  
Vol 328-330 ◽  
pp. 1930-1934
Author(s):  
Xiao Hui Wang ◽  
Jing Yu Wang ◽  
Jing Lin Zhang ◽  
Ting Liang
Keyword(s):  
Infrared Absorption ◽  
Coal Mine ◽  
Detection Accuracy ◽  
Calculation Results ◽  
Gas Environment ◽  
Intrinsic Safety

Based on the theory of infrared absorption, a new kind of portable methane alarming device has been developed with the advantages that cost-low, maintenance-free, miniaturization, and integration. Intrinsically safe circuit is absolutely necessary, because the device is installed in the explosive gas environment. To improve the detection accuracy and increase the safety of the coal mine, the device’s intrinsically safe circuit has been designed. All parameters of the circuit are designed in accordance with IEC 60079-0-2007 Explosive atmospheres-Part 0: Equipment - General requirements and IEC 60079-11-2006 Explosive atmospheres-Part 11: Equipment protection by intrinsic safety “i”. The related analyses and calculation results show that this intrinsically safe circuit is workable and reliable.

Maintenance and Safety Requirements of Flameproof and Intrinsically Safe Equipment for Coal Mines

2017 ◽  
Vol 6 (1) ◽  
pp. 9
Author(s):  
B. Ahirwal ◽  
Arvind Kumar Singh ◽  
Rajendra Kumar Vishwakarm
Keyword(s):  
New Technology ◽  
Electrical Equipment ◽  
Basic Knowledge ◽  
System Efficiency ◽  
Ignition Energy ◽  
Safe Operation ◽  
Safety Requirements ◽  
Safety Parameters ◽  
Inspection And Maintenance ◽  
Intrinsic Safety

<span lang="EN-US">In the generation of the new technology segment, new explosionproof (Ex) equipment are being installed to make systems suitable for use in hazardous areas of mines. Generally, 80-90% equipment having flameproof (Exd) and intrinsic safety (Exi) methodology of protection are used in the mines for safe operation. The maintenance and safety are two vital parameters to improve the system efficiency of installation in the mines. These parameters are also responsible for the productivity of the mines. The minimum breakdown and maximum safety are the prime concerns of the mines to increase the production. Many observations and basic knowledge are necessary of safety parameters of Ex protections while doing maintenance because micro joules energy is sufficient to ignite the hazardous areas of mines. Trained and skilled personals having good knowledge of Ex protections are required to maintain the limitations of ignition energy sources of Ex equipment to prevent explosion in the mines. A regular and organized scheme of inspection and maintenance may ensure continued, satisfactory and safe operation of Ex electrical equipment in mines. The important points for safety and maintenance of Exd and Exi equipment are pondered in this paper.</span>

FTA-Based Human Unsafe Behavior Control in Coal Mine Intrinsic Safety Management

2011 ◽  
Vol 291-294 ◽  
pp. 3207-3211 ◽  
Author(s):  
Tian Bao Sheng ◽  
Yan Liang Zhang ◽  
Qing Yun Wei
Keyword(s):  
Coal Mine ◽  
Safety Management ◽  
Fault Tree Analysis ◽  
Safety Hazard ◽  
Safety Control ◽  
Organization Management ◽  
Short Period ◽  
Unsafe Behavior ◽  
Skills Education ◽  
Intrinsic Safety

The demand for coal keeps on increasing with the development of economy. However the short period of mine construction is apt to formulate safety hazard, the quality is easily neglected in construction process. Based on intrinsic safety management in ZhaoGu coal mine, workers’ unsafe behavior is analyzed from two aspects, i.e. construction workers and management, utilizing the fault tree analysis. Then some measures to guarantee security management are proposed, such as: (1) safety control on behavior and psychology. (2) strengthening on skills education. (3) optimizing organization management. (4) respecting workers’ psychological and physical cycle and enhancing their safety consciousness.

scholarly journals On the method of calculating the energy density of laser radiation in a metal surface modification

2021 ◽  
Vol 2124 (1) ◽  
pp. 012014
Author(s):  
E S Trushin ◽  
M R Dasaev ◽  
O V Kalakutskaya ◽  
A P Voloshenko
Keyword(s):  
Surface Modification ◽  
Laser Radiation ◽  
Laser Ablation ◽  
Energy Density ◽  
Metal Surface ◽  
Radiation Effect ◽  
Universal Method ◽  
Unified Approach ◽  
Geometric Characteristics ◽  
Comparison Of The Results

Abstract Today, modification of metal surfaces using laser radiation (laser ablation) is one of the most common processing methods in various scientific studies. At the same time, there is no unified approach to estimating the energy of laser radiation impact on the metal surface, which significantly complicates the comparison of the results of studies performed at different parameters of laser radiation. In the present work, a universal method of calculating the energy density of laser radiation impact on the surface is presented. The formation of relief with identical geometric characteristics at different parameters of laser radiation, but with the same energy density of radiation effect on the surface being modified, was experimentally confirmed.

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