In situ resuspension rate monitoring method in the littoral zone with multi-ecotypes of a shallow wind-disturbed lake

2019 ◽  
Vol 26 (8) ◽  
pp. 7476-7485 ◽  
Author(s):  
Chuang Qi ◽  
Xiao-guang Xu ◽  
Kuan Shi ◽  
Li-min Zhang ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Littoral Zone ◽  
Monitoring Method ◽  
Resuspension Rate

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 A Methodology for Estimating the Parameters in Three-Dimensional Cohesive Sediment Transport Models by Assimilating In Situ Observations with the Adjoint Method

2017 ◽  
Vol 34 (7) ◽  
pp. 1469-1482 ◽  
Author(s):  
Daosheng Wang ◽  
Jicai Zhang ◽  
Ya Ping Wang ◽  
Xianqing Lv ◽  
Yang Yang ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Adjoint Method ◽  
Settling Velocity ◽  
Transport Model ◽  
Three Dimensional ◽  
Temporal Variations ◽  
Cohesive Sediment ◽  
Cohesive Sediment Transport ◽  
Resuspension Rate

AbstractThe model parameters in the suspended cohesive sediment transport model are quite important for the accurate simulation of suspended sediment concentrations (SSCs). Based on a three-dimensional cohesive sediment transport model and its adjoint model, the in situ observed SSCs at four stations are assimilated to simulate the SSCs and to estimate the parameters in Hangzhou Bay in China. Numerical experimental results show that the adjoint method can efficiently improve the simulation results, which can benefit the prediction of SSCs. The time series of the modeled SSCs present a clear semidiurnal variation, in which the maximal SSCs occur during the flood tide and near the high water level due to the large current speeds. Sensitivity experiments prove that the estimated results of the settling velocity and resuspension rate, especially the temporal variations, are robust to the model settings. The temporal variations of the estimated settling velocity are negatively correlated with the tidal elevation. The main reason is that the mean size of the suspended sediments can be reduced during the flood tide, which consequently decreases the settling velocity according to Stokes’s law, and it is opposite in the ebb tide. The temporal variations of the estimated resuspension rate and the current speeds have a significantly positive correlation, which accords with the dynamics of the resuspension rate. The temporal variations of the settling velocity and resuspension rate are reasonable from the viewpoint of physics, indicating the adjoint method can be an effective tool for estimating the parameters in the sediment transport models.

Advances in Wear Measurement by Acoustic Emission Analysis Compared to Radionuclide Technique

2011 ◽  
Author(s):  
A. Albers ◽  
S. G. Kelemen
Keyword(s):  
Particle Size ◽  
Acoustic Emission ◽  
Noise Analysis ◽  
Wear Volume ◽  
Friction Behavior ◽  
Emission Analysis ◽  
Monitoring Method ◽  
Solid Friction ◽  
First Time

Online analysis of a tribological contact without changing the conditions of the system is a challenging exercise until today. Yet, it is not possible to detect wear and the particle size ith one method. Numerous works study different phenomena of the behavior of ultrasonic structure-borne noise in dry friction contacts. However all these experiments are limited to basic pin-disc experiments without any concrete reference to an application. A new application for detecting real contact-geometry, wear and particle size with one in-situ condition monitoring method on a test rigs is presented in this paper. The method of structure-born noise analysis has proven to be suitable for detecting the occurrence of solid friction [1]–[4]. By using a broadband piezoelectric acoustic emission sensor to detect ultrasonic structure-born noise, caused by metal-to-metal contact it is now possible to study different types of phenomena during their time of appearance. The Radionuclide Technology (RNT) was used the first time at dry running friction systems. With the RNT it is possible to correlate ultrasonic structure-borne noise with wear volume in dry running friction systems. The application is used for deeper understanding of the friction behavior and wear phenomena in dry running contacts.

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.

A New Automatic In Situ Sampling and Monitoring Method for Water

2012 ◽  
Vol 7 (1) ◽  
pp. 261-266
Author(s):  
Jingtao Liu ◽  
Jichao Sun ◽  
Guanxing Huang ◽  
Jincui Wang ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Monitoring Method

Theoretical Study on Coal Mine In Situ Stress’s Monitoring Method

2013 ◽  
Vol 446-447 ◽  
pp. 1113-1117 ◽  
Author(s):  
Hong Biao Wang ◽  
Chao An ◽  
Shan Dong Zhang
Keyword(s):  
Coal Mine ◽  
In Situ Stress ◽  
Mining Engineering ◽  
Stress Monitoring ◽  
Working Process ◽  
Monitoring Method ◽  
Deformation And Failure ◽  
The Stability ◽  
Dynamic Phenomena

For mine mining, In-situ stress is the fundamental force that causes the deformation and failure of surrounding rock in the mining engineering and supporting, and produces mine dynamic phenomena. Among many factors which affecting the stability of mining engineering, In-situ stress is the main and one of the most fundamental factors. According to the In-situ stress monitoring method some coal mine adopted, this paper introduces the concrete principle and working process.

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.

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.

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