scholarly journals In-Situ Monitoring and Diagnosing for Fused Filament Fabrication Process Based on Vibration Sensors

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2589 ◽  
Author(s):  
Yongxiang Li ◽  
Wei Zhao ◽  
Qiushi Li ◽  
Tongcai Wang ◽  
Gong Wang
Keyword(s):  
Product Quality ◽  
Real Time ◽  
Case Studies ◽  
Complex Geometry ◽  
Identification Accuracy ◽  
In Situ Monitoring ◽  
Support Vector ◽  
Fused Filament Fabrication ◽  
Vibration Sensors

Fused filament fabrication (FFF) is one of the most widely used additive manufacturing (AM) technologies and it has great potential in fabricating prototypes with complex geometry. For high quality manufacturing, monitoring the products in real time is as important as maintaining the FFF machine in the normal state. This paper introduces an approach that is based on the vibration sensors and data-driven methods for in-situ monitoring and diagnosing the FFF process. The least squares support vector machine (LS-SVM) algorithm has been applied for identifying the normal and filament jam states of the FFF machine, besides fault diagnosis in real time. The identification accuracy for the case studies explored here using LS-SVM is greater than 90%. Furthermore, to ensure the product quality during the FFF process, the back-propagation neural network (BPNN) algorithm has been used to monitor and diagnose the quality defects, as well as the warpage and material stack caused by abnormal leakage for the products in-situ. The diagnosis accuracy for the case studies explored here using BPNN is greater than 95%. Results from the experiments show that the proposed approach can accurately recognize the machine failures and quality defects during the FFF process, thus effectively assuring the product quality.

scholarly journals A sample cell for the study of enzyme-induced carbonate precipitation at the grain-scale and its implications for biocementation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jennifer Zehner ◽  
Anja Røyne ◽  
Pawel Sikorski
Keyword(s):  
Real Time ◽  
Laser Scanning Microscopy ◽  
In Situ Monitoring ◽  
Confocal Laser ◽  
Precipitation Process ◽  
Successful Implementation ◽  
Detailed Knowledge ◽  
Carbonate Precipitation ◽  
Sample Cell

AbstractBiocementation is commonly based on microbial-induced carbonate precipitation (MICP) or enzyme-induced carbonate precipitation (EICP), where biomineralization of $$\text {CaCO}_{3}$$ CaCO 3 in a granular medium is used to produce a sustainable, consolidated porous material. The successful implementation of biocementation in large-scale applications requires detailed knowledge about the micro-scale processes of $$\text {CaCO}_{3}$$ CaCO 3 precipitation and grain consolidation. For this purpose, we present a microscopy sample cell that enables real time and in situ observations of the precipitation of $$\text {CaCO}_{3}$$ CaCO 3 in the presence of sand grains and calcite seeds. In this study, the sample cell is used in combination with confocal laser scanning microscopy (CLSM) which allows the monitoring in situ of local pH during the reaction. The sample cell can be disassembled at the end of the experiment, so that the precipitated crystals can be characterized with Raman microspectroscopy and scanning electron microscopy (SEM) without disturbing the sample. The combination of the real time and in situ monitoring of the precipitation process with the possibility to characterize the precipitated crystals without further sample processing, offers a powerful tool for knowledge-based improvements of biocementation.

scholarly journals Sensitive In Situ Monitoring of a Recombinant Bioluminescent Yersinia enterocolitica Reporter Mutant in Real Time on Camembert Cheese

2002 ◽  
Vol 68 (11) ◽  
pp. 5737-5740 ◽  
Author(s):  
Ariel Maoz ◽  
Ralf Mayr ◽  
Geraldine Bresolin ◽  
Klaus Neuhaus ◽  
Kevin P. Francis ◽  
...  
Keyword(s):  
Real Time ◽  
Yersinia Enterocolitica ◽  
Photon Emission ◽  
Photon Counting ◽  
In Situ Monitoring ◽  
Charge Coupled Device ◽  
Reading Frame ◽  
Intensified Charge Coupled Device ◽  
Camembert Cheese

ABSTRACT Bioluminescent mutants of Yersinia enterocolitica were generated by transposon mutagenesis using a promoterless, complete lux operon (luxCDABE) derived from Photorhabdus luminescens, and their production of light in the cheese environment was monitored. Mutant B94, which had the lux cassette inserted into an open reading frame of unknown function was used for direct monitoring of Y. enterocolitica cells on cheeses stored at 10°C by quantifying bioluminescence using a photon-counting, intensified charge-coupled device camera. The detection limit on cheese was 200 CFU/cm2. Bioluminescence of the reporter mutant was significantly regulated by its environment (NaCl, temperature, and cheese), as well as by growth phase, via the promoter the lux operon had acquired upon transposition. At low temperatures, mutant B94 did not exhibit the often-reported decrease of photon emission in older cells. It was not necessary to include either antibiotics or aldehyde in the food matrix in order to gain quantitative, reproducible bioluminescence data. As far as we know, this is the first time a pathogen has been monitored in situ, in real time, in a “real-product” status, and at a low temperature.

Fast, Real-Time, In Situ Monitoring of Solar Ultraviolet Radiation Using Sunlight-Driven Photoresponsive Liquid Crystals

2018 ◽  
Vol 6 (6) ◽  
pp. 1701337 ◽  
Author(s):  
Jiajun Tian ◽  
Yanrong He ◽  
Juntao Li ◽  
Jie Wei ◽  
Gangqiang Li ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Ultraviolet Radiation ◽  
Real Time ◽  
In Situ Monitoring ◽  
Solar Ultraviolet Radiation ◽  
Solar Ultraviolet

Multifunctional 3D electrode platform for real-time in situ monitoring and stimulation of cardiac tissues

2018 ◽  
Vol 112 ◽  
pp. 149-155 ◽  
Author(s):  
Ning Zhang ◽  
Flurin Stauffer ◽  
Benjamin R. Simona ◽  
Feng Zhang ◽  
Zhao-Ming Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
In Situ Monitoring ◽  
Cardiac Tissues ◽  
3D Electrode ◽  
Stimulation Of

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.

Comparative, real-time in situ monitoring of galvanic corrosion in Mg-Mg2Ca and Mg-MgZn2 couples in Hank’s solution

2019 ◽  
Vol 161 ◽  
pp. 108185 ◽  
Author(s):  
Yang Liu ◽  
Xiao Liu ◽  
Zechuan Zhang ◽  
Nicholas Farrell ◽  
Dafu Chen ◽  
...  
Keyword(s):  
Real Time ◽  
Galvanic Corrosion ◽  
In Situ Monitoring ◽  
Hank’S Solution

Real-time in situ monitoring of signal molecules’ evolution in apoptotic pathway via Au–Se bond constructed nanoprobe

2020 ◽  
Vol 147 ◽  
pp. 111755 ◽  
Author(s):  
Xiaonan Gao ◽  
Jia Li ◽  
Mingming Luan ◽  
Yanhua Li ◽  
Wei Pan ◽  
...  
Keyword(s):  
Real Time ◽  
In Situ Monitoring ◽  
Signal Molecules ◽  
Apoptotic Pathway
Sign in / Sign up

Export Citation Format

Share Document