scholarly journals In-situ formation compaction monitoring in deep reservoirs by use of fiber optics

2015 ◽  
Vol 372 ◽  
pp. 393-394 ◽  
Author(s):  
H. Ikeda ◽  
S. Kunisue ◽  
D. Nohara ◽  
K. Ooba ◽  
T. Kokubo
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
In Situ Monitoring ◽  
Monitoring Methods ◽  
Observation Well ◽  
Monitoring Method ◽  
In Situ Formation ◽  
Several Intervals ◽  
Sensor Assembly

Abstract. We have devised a new in situ monitoring method for the amount of stratified compaction in borehole drilled several hundred meters underground. This newly developed epoch-making monitoring system differs from conventional monitoring methods for land subsidence in that it is designed to continuously monitor the amounts of displacement in several intervals separately, using optical fibers fitted in the sensor assembly. This report presents results from a deep observation well. This is a continued report from the previous one on EISOLS 2010.

Measuring floating ice thickness with optical fibers and DAS, a test case study on a frozen moutain lake.

2021 ◽  
Author(s):  
Olivier Coutant ◽  
Ludovic Moreau ◽  
Pierre Boué ◽  
Eric Larose ◽  
Arnaud Cimolino
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Ambient Noise ◽  
Seismic Waves ◽  
Safety Issue ◽  
Seismic Survey ◽  
Ice Thickness ◽  
Test Case ◽  
Monitoring Method

<p>Accurate monitoring of floating ice thickness is an important safety issue for northern countries where lakes, fjords, and coasts are covered with ice in winter, and used by people to travel. For example in Finland, 15-20 fatal accidents occur every year due to ice-related drowning. We have explored the potential of fiber optics to measure the propagation of seismic waves guided in the ice layer, in order to infer its thickness via the inversion of the dispersion curves. An optical fiber was deployed on a frozen lake at Lacs Roberts (2400m) above Grenoble and we measured with a DAS the signal generated by active sources (hammer) and ambient noise. We demonstrate that we can retrieve the ice thickness. This monitoring method could be of interest since the deployment of a fiber on ice is quite simple (e.g. using a drone) compared to other techniques for ice thickness estimation such as seismic survey or manual drilling.</p>

In-Situ Monitoring of Laser Powder Bed Fusion Process Anomalies via a Comprehensive Analysis of Off-Axis Camera Data

2020 ◽  
Author(s):  
Chaitanya Krishna Prasad Vallabh ◽  
Yubo Xiong ◽  
Xiayun Zhao
Keyword(s):  
Real Time ◽  
Network Architecture ◽  
Video Data ◽  
In Situ Monitoring ◽  
Process Efficiency ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Monitoring Method ◽  
Powder Bed

Abstract In-situ monitoring of a Laser Powder-Bed Fusion (LPBF) additive manufacturing process is crucial in enhancing the process efficiency and ensuring the built part integrity. In this work, we present an in-situ monitoring method using an off-axis camera for monitoring layer-wise process anomalies. The in-situ monitoring is performed with a spatial resolution of 512 × 512 pixels, with each pixel representing 250 × 250 μm and a relatively high data acquisition rate of 500 Hz. An experimental study is conducted by using the developed in-situ off-axis method for monitoring the build process for a standard tensile bar. Real-time video data is acquired for each printed layer. Data analytics methods are developed to identify layer-wise anomalies, observe powder bed characteristics, reconstruct 3D part structure, and track the spatter dynamics. A deep neural network architecture is trained using the acquired layer-wise images and tested by images embedded with artificial anomalies. The real-time video data is also used to perform a preliminary spatter analysis along the laser scan path. The developed methodology is aimed to extract as much information as possible from a single set of camera video data. It will provide the AM community with an efficient and capable process monitoring tool for process control and quality assurance while using LPBF to produce high-standard components in industrial (such as, aerospace and biomedical industries) applications.

Analysis of nonlinear optical phenomena: perspective of in-situ monitoring method of the semiconductor-film crystal-structure

1990 ◽  
Author(s):  
Valery V. Balaniuk ◽  
Victor F. Krasnov ◽  
Nikolai A. Kul'chitzkii ◽  
Semion L. Musher ◽  
Vasily I. Proc' ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nonlinear Optical ◽  
In Situ Monitoring ◽  
Semiconductor Film ◽  
Monitoring Method ◽  
Optical Phenomena ◽  
Nonlinear Optical Phenomena

scholarly journals Monitoring Method of Longitudinal Land Subsidence and Deformation in Seismic Geological Disasters

2020 ◽  
Vol 24 (3) ◽  
pp. 259-266
Author(s):  
Aimei Xu ◽  
Hojatallah Azarkhosh ◽  
Erjun Wu
Keyword(s):  
Optical Fibers ◽  
Land Subsidence ◽  
Confining Pressure ◽  
Ground Subsidence ◽  
Correction Coefficient ◽  
Geological Hazards ◽  
Distributed Monitoring ◽  
Monitoring Methods ◽  
Monitoring Method ◽  
Geological Disasters

Monitoring of longitudinal land subsidence and deformation in seismic and geological hazards plays an important role in preventing and curing land collapse, land subsidence, and ground cracks. In this paper, a distributed monitoring model experiment on vertical land subsidence and deformation of seismic and geological hazards is carried out by Brillouin optical frequency-domain analysis technology (BOTDA). By using the self-made indoor longitudinal land subsidence and deformation simulation box, different intensity seismic ground is simulated by air bag. Distributed optical fibers are used to monitor the longitudinal land subsidence and deformation during different intensity seismic and geological disasters. According to different intensity seismic and geological disasters, distributed sensing optical fibers cooperate with the ground to compress or stretch longitudinally and obtain the data of longitudinal land subsidence and deformation. The correction coefficient is introduced to modify the monitoring data of confining pressure-sensing optical fiber and complete the precise monitoring of vertical land subsidence and deformation in seismic and geological hazards. The experimental results show that this method can monitor the vertical ground subsidence and deformation of seismic and geological hazards under different conditions, and the monitoring efficiency and cost are superior to GPS and inertial monitoring methods, and the practical application value is high.

scholarly journals In-Situ Monitoring of a Filament Wound Pressure Vessel by the MWCNT Sensor under Hydraulic Fatigue Cycling and Pressurization

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1396 ◽  
Author(s):  
Biao Xiao ◽  
Bin Yang ◽  
Fu-Zhen Xuan ◽  
Yun Wan ◽  
Chaojie Hu ◽  
...  
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessels ◽  
In Situ Monitoring ◽  
Measured Signal ◽  
Monitoring Method ◽  
Fatigue Cycling ◽  
Filament Wound ◽  
Composite Pressure Vessel ◽  
Composite Pressure Vessels

As a result of the high specific strength/stiffness to mass ratio, filament wound composite pressure vessels are extensively used to contain gas or fluid under pressure. The ability to in-situ monitor the composite pressure vessels for possible damage is important for high-pressure medium storage industries. This paper describes an in-situ monitoring method to permanently monitor composite pressure vessels for their structural integrity. The sensor is made of a multi-walled carbon nanotube (MWCNT) that can be embedded in the composite skin of the pressure vessels. The sensing ability of the sensor is firstly evaluated in various mechanical tests, and in-situ monitoring experiments of a full-scale composite pressure vessel during hydraulic fatigue cycling and pressurization are performed. The monitoring results of the MWCNT sensor are compared with the strains measured by the strain gauges. The results show that the measured signal by the developed sensor matches the mechanical behavior of the composite laminates under various load conditions. In the hydraulic fatigue test, the relationship between the resistance and the strain is built, and could be used to quantitative monitor the filament wound pressure vessel. The bursting of the pressure vessel can be detected by the sharp increase of the MWCNT sensor resistance. Embedding the MWCNT sensor into the composite pressure vessel is successfully demonstrated as a promising method for structural health monitoring.

scholarly journals In situ monitoring of the formation of nanoscale polyelectrolyte coatings on optical fibers using Surface Plasmon Resonances

2010 ◽  
Vol 18 (19) ◽  
pp. 20409 ◽  
Author(s):  
Yanina Shevchenko ◽  
Nur Uddin Ahamad ◽  
Anatoli Ianoul ◽  
Jacques Albert
Keyword(s):  
Surface Plasmon ◽  
Optical Fibers ◽  
In Situ Monitoring ◽  
Surface Plasmon Resonances ◽  
Plasmon Resonances

Online Prediction and Verification of Cured Quality of Advanced Composites in Autoclave Process

2016 ◽  
Vol 703 ◽  
pp. 3-10
Author(s):  
Yong An Zhang ◽  
Li Hua Zhan
Keyword(s):  
In Situ Monitoring ◽  
Metallographic Analysis ◽  
Resin Flow ◽  
Composite Part ◽  
Monitoring Method ◽  
Verification Method ◽  
Part Quality ◽  
Ultrasonic Phased Array

The strain in curing process of composite part would be influenced by curing compaction, resin flow, curing action and tool-part interaction, meanwhile these factors would also influence the final cured quality of composite part. In this paper, FBG(fiber Bragg grating) sensors are used to in-situ monitoring the strain of composite parts, which are cured in four different pressure situation by autoclave: 0.0Mpa,0.2Mpa,0.4Mpa,0.6MPa. by analyzing the strain change rule, the part quality is predicted, then the predictive result is compared with some verification method: measurement of part’s boundary dimension, ultrasonic phased array scanning, metallographic analysis. The result shows that, the prediction is consistent with verification, the in-situ monitoring method by using FBG sensor is available for predicting cured quality of composite parts accurately: increase curing pressure is benefit of part compaction, resin flow, and reduce delamination,pores in composite part, finally improving the part quality dramatically.

Precision fabrication of D-shaped single-mode optical fibers by in situ monitoring

1994 ◽  
Vol 12 (9) ◽  
pp. 1524-1531 ◽  
Author(s):  
M.H. Cordaro ◽  
D.L. Rode ◽  
T.S. Barry ◽  
R.R. Krchnavek
Keyword(s):  
Optical Fibers ◽  
Single Mode ◽  
In Situ Monitoring
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