Fiber optic control system for geotechnical parameters of mine

In the article a fiber-optic method for monitoring rock pressure is considered, as well as the magnitude of the displacement of the layers of the stope hanging wall is measured. The authors analyze the applied rock pressure testing methods. The reasons for the need to create a safe system are given, the main requirement of which is the condition of compliance with all safety requirements during mining operations. The developed quasi-distributed fiber-optic system is capable of measuring with high accuracy changes in rock pressure and displacement of roof rocks in an explosive environment, also does not require expensive equipment associated with the use of a range of analyzers and reflectometers. A scheme has been proposed to simplify the testing process. The results of dependences of additional optical losses on the applied force are obtained

Download Full-text

Optimization of sol-gel based fibre-optic cholinesterase biosensor for the determination of organophosphorus pesticides

Water Science & Technology ◽

10.2166/wst.2000.0580 ◽

2000 ◽

Vol 42 (7-8) ◽

pp. 283-290 ◽

Cited By ~ 8

Author(s):

H.-C. Tsai ◽

R.-A. Doong

Keyword(s):

Fiber Optic ◽

Ph Value ◽

Rapid Determination ◽

Organophosphorus Pesticides ◽

Sol Gel ◽

Neutral Red ◽

Fluorescent Indicators ◽

Low Leakage ◽

Fiber Optic System

A sol-gel based fiber-optic biosensor with acetylcholinesterase as the biorecognition element has been developed for the rapid determination of organophosphorus pesticides. Nine fluorescent indicators, acridine, acridine orange, neutral red, DAPI, rhodamine B, fluorescein, umbelliferone, FITC on celite and FITC-dextran, have been examined to optimize the fiber-optic system. Results showed that acridine and FITCs were sensitive to the change of pH value caused by the enzyme-substrate catalysis reaction. However, the sensitivity of acridine was 260 times lower than that of FITCs. Higher toxicity of acridine to acetylcholinesterase than FITC was also observed. Moreover, the high-molecular-weight FITC-dextran showed low leakage rate when immobilizing using sol-gel technology, showing that the FITC-dextran was a suitable pH sensitive fluorescent indicator for the OPPs biosensor. The response of the fiber-optic biosensor to the substrate, acetylcholine, was highly reproducible (RSD=3.5%). A good linearity of acetylcholine in the range from 0.5 to 20 mM was also obtained (R2=0.98). Furthermore, a 30% inhibition can be achieved in 30min when 152 ppb paraoxon was added into the system. The results show the possibility for real-time determination of organophosphorus pesticides by using the biosensor developed in this study.

Download Full-text

Multifunctional fiber optic system for microwave signals transmitting in frequency range from 0.135 to 40 GHz

Journal of Physics Conference Series ◽

10.1088/1742-6596/1745/1/012014 ◽

2021 ◽

Vol 1745 (1) ◽

pp. 012014

Author(s):

G A Pchelkin ◽

V Yu Rud ◽

V V Davydov

Keyword(s):

Fiber Optic ◽

Frequency Range ◽

Optic System ◽

Microwave Signals ◽

Fiber Optic System

Download Full-text

Fluorescent Organofilms for Oxygen Sensing in Organic Solvents Using a Fiber Optic System

The Analyst ◽

10.1039/a703655h ◽

1997 ◽

Vol 122 (11) ◽

pp. 1405-1410 ◽

Cited By ~ 28

Author(s):

N. Velasco-García ◽

M. J. Valencia-González ◽

M. E. Díaz-García

Keyword(s):

Organic Solvents ◽

Fiber Optic ◽

Oxygen Sensing ◽

Optic System ◽

Fiber Optic System

Download Full-text

Study of a construction opportunity fiber optic system telecommunications for the analysis of the turbojet engine serviceability

10.1117/12.634558 ◽

2005 ◽

Author(s):

Tatiana P. Andreeva ◽

Sergey L. Vinogradov

Keyword(s):

Fiber Optic ◽

Optic System ◽

Turbojet Engine ◽

Fiber Optic System

Download Full-text

Assessment of instability initiation in exposed salt rock roofs

Gornyi Zhurnal ◽

10.17580/gzh.2021.04.04 ◽

2021 ◽

pp. 34-38

Author(s):

D. N. Shkuratskiy ◽

D. S. Chernopazov ◽

I. B. Vaulina

Keyword(s):

Damage Zone ◽

Shear Plane ◽

Plane Elasticity ◽

Mining Operations ◽

Support Design ◽

Salt Rocks ◽

Main Requirement ◽

Potash Salt ◽

Failure Conditions ◽

Coulomb Criterion

Stability of rocks is the main requirement for the safe operation of mines. For this purpose, certain measures are applied for the protection and support of underground openings, including roof support design and roof arrangement in the most stable rocks. Stability assessment of underground excavations is largely related to their roof stability. Determination of possible instability conditions in mine roofs governs the choice of support system design and parameters of mine excavations. The Upper Kama Potash Salt Deposit represents a stratified layer of solid salt rocks. Roof instability develops as stratification and roof collapse. The Mohr–Coulomb criterion of coherent rocks is currently used to estimate parameters of a possible damage zone in the exposed roof. This criterion allows evaluating shear plane angles in roof rocks and, as a result, finding parameters of the possible collapse zone. The experience of mining operations in the Upper Kama deposit shows different failure conditions as against the Mohr–Coulomb criterion as the stress state is scarcely included in the criterion used. This study is an attempt to assess parameters of rock exposures by solving a Lame problem in terms of a single mine excavation. The analytical results were compared with the parameters obtained from the plane elasticity solutions by the finite element method. Based on the implemented studies, an engineering approach is developed for the assessment of anticipated instability parameters in exposed roofs in horizontal excavations driven in salt rocks.

Download Full-text