scholarly journals Real Time In-situ Detection System Research for Methane in Offshore Shallow Gas based on Thin Film Interface

2018 ◽  
Vol 232 ◽  
pp. 04053
Author(s):  
Cheng-xing Miao ◽  
Qing Li ◽  
Sheng-yao Jia

In order to get ridded of the non real-time detection methods of artificial site sampled and laboratory instrument analyzed in the field of methane detection in the offshore shallow gas, real-time in-situ detection system for methane in offshore shallow gas was designed by the film interface.The methane in the offshore shallow gas through the gas-liquid separation membrane of polymer permeation into the system internal detection probe, analog infrared micro gas sensor sensed the methane concentration and the corresponded output value, data acquisition and communication node fitted into standard gas concentration.Based on the experimental data compared with the traditional detection method, and further analyzed the causes of error produced by the case experiment. The application results show that the system can achieve a single borehole layout, long-term on-line in-situ on-line detection, and improve the detection efficiency and the timeliness of the detection data.

2021 ◽  
Vol 11 (11) ◽  
pp. 5210
Author(s):  
Sujung Min ◽  
Hara Kang ◽  
Bumkyung Seo ◽  
Changhyun Roh ◽  
Sangbum Hong ◽  
...  

The highly reliable and direct detection of radioactive cesium has gained potential interest due to in-situ detection and monitoring in environments. In this study, we elucidated an integrated and portable probe based on functional plastic scintillator for detection of radioactive cesium. A functional plastic scintillator with improved detection efficiency was fabricated including CdTe (cadmium telluride) material. Monolith-typed functional plastic scintillator having a diameter of 50 mm and a thickness of 30 mm was manufactured by adding 2,5-diphenyloxazole (PPO, 0.4 wt%), 1,4 di[2-(5phenyloxazolyl)]benzene (POPOP, 0.01 wt%), and CdTe (0.2 wt%) materials in a styrene-based matrix. To evaluate the applicability of the plastic scintillator manufactured to in-situ radiological measurement, an integrated plastic detection system was created, and the measurement experiment was performed using the Cs-137 radiation source. Additionally, detection efficiency was compared with a commercial plastic scintillator. As results, the efficiency and light yield of a functional plastic scintillator including CdTe were higher than a commercial plastic scintillator. Furthermore, the remarkable performance of the functional plastic scintillator was confirmed through comparative analysis with Monte Carlo simulation.


Optik ◽  
2021 ◽  
pp. 167711
Author(s):  
Enlai Wan ◽  
Zhongmou Sun ◽  
Yuzhu Liu

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1937 ◽  
Author(s):  
Adam Stawiarski ◽  
Aleksander Muc

In this paper, the elastic wave propagation method was used in damage detection in thin structures. The effectiveness and accuracy of the system based on the wave propagation phenomenon depend on the number and localization of the sensors. The utilization of the piezoelectric (PZT) transducers makes possible to build a low-cost damage detection system that can be used in structural health monitoring (SHM) of the metallic and composite structures. The different number and localization of transducers were considered in the numerical and experimental analysis of the wave propagation phenomenon. The relation of the sensors configuration and the damage detection capability was demonstrated. The main assumptions and requirements of SHM systems of different levels were discussed with reference to the damage detection expectations. The importance of the damage detection system constituents (sensors number, localization, or damage index) in different levels of analysis was verified and discussed to emphasize that in many practical applications introducing complicated procedures and sophisticated data processing techniques does not lead to improving the damage detection efficiency. Finally, the necessity of the appropriate formulation of SHM system requirements and expectations was underlined to improve the effectiveness of the detection methods in particular levels of analysis and thus to improve the safety of the monitored structures.


2020 ◽  
Vol 8 (9) ◽  
pp. 642
Author(s):  
Chao Ji ◽  
Cynthia Juyne Beegle-Krause ◽  
James D. Englehardt

Submerged oil, oil in the water column (neither at the surface nor on the bottom), was found in the form of oil droplet layers in the mid depths between 900–1300 m in the Gulf of Mexico during and following the Deepwater Horizon oil spill. The subsurface peeling layers of submerged oil droplets were released from the well blowout plume and moved along constant density layers (also known as isopycnals) in the ocean. The submerged oil layers were a challenge to locate during the oil spill response. To better understand and find submerged oil layers, we review the mechanisms of submerged oil formation, along with detection methods and modeling techniques. The principle formation mechanisms under stratified and cross-current conditions and the concepts for determining the depths of the submerged oil layers are reviewed. Real-time in situ detection methods and various sensors were used to reveal submerged oil characteristics, e.g., colored dissolved organic matter and dissolved oxygen levels. Models are used to locate and to predict the trajectories and concentrations of submerged oil. These include deterministic models based on hydrodynamical theory, and probabilistic models exploiting statistical theory. The theoretical foundations, model inputs and the applicability of these models during the Deepwater Horizon oil spill are reviewed, including the pros and cons of these two types of models. Deterministic models provide a comprehensive prediction on the concentrations of the submerged oil and may be calibrated using the field data. Probabilistic models utilize the field observations but only provide the relative concentrations of the submerged oil and potential future locations. We find that the combination of a probabilistic integration of real-time detection with trajectory model output appears to be a promising approach to support emergency response efforts in locating and tracking submerged oil in the field.


Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2536 ◽  
Author(s):  
Jian He ◽  
Yongfei Guo ◽  
Hangfei Yuan

Efficient ship detection is essential to the strategies of commerce and military. However, traditional ship detection methods have low detection efficiency and poor reliability due to uncertain conditions of the sea surface, such as the atmosphere, illumination, clouds and islands. Hence, in this study, a novel ship target automatic detection system based on a modified hypercomplex Flourier transform (MHFT) saliency model is proposed for spatial resolution of remote-sensing images. The method first utilizes visual saliency theory to effectively suppress sea surface interference. Then we use OTSU methods to extract regions of interest. After obtaining the candidate ship target regions, we get the candidate target using a method of ship target recognition based on ResNet framework. This method has better accuracy and better performance for the recognition of ship targets than other methods. The experimental results show that the proposed method not only accurately and effectively recognizes ship targets, but also is suitable for spatial resolution of remote-sensing images with complex backgrounds.


2009 ◽  
Vol 2 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Craig Baker-Austin ◽  
Anthony Gore ◽  
James D. Oliver ◽  
Rachel Rangdale ◽  
J Vaun McArthur ◽  
...  

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