scholarly journals Nondestructive Measurement of Emissivity of Damaged Parts of Coatings

Surfaces ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 257-267
Author(s):  
Dikai Jiang ◽  
Yiwen Li ◽  
Weizhuo Hua ◽  
Peng Kuang ◽  
Bo Xu
Keyword(s):  
Small Diameter ◽  
Thermal Imager ◽  
Application Process ◽  
Large Area ◽  
Nondestructive Measurement ◽  
Coating Surface ◽  
Measurement Results ◽  
Wear Damage ◽  
Damage Types ◽  
Emissivity Measurements

Low Infrared emissivity coating (LIREC) is prone to generating some problems such as bulges, degumming, and abrasion. In order to study whether the performance of LIREC under different damages can meet the work needs, it is essential to timely measure and evaluate the performance state of LIREC in the application process. The existing methods for measuring the damage of LIREC have some disadvantages such as expensive equipment, complex operation, and inaccurate measurement results. In this paper, a measurement method of LIREC damage capability based on thermal imager is proposed. The radiation temperature is measured by thermal imager, the real temperature and ambient temperature of coating surface are measured by thermocouple, and the emittance of coating surface is calculated. Non-contact and continuous large-area emissivity measurements are carried out on the damaged parts of the coating and verified by experiments. The measurement results show that the different damage types and damage degrees directly affect the measurement results of LIREC. Wear damage increases the emissivity of the coating while debonding damage basically does not change the coating emissivity. Shedding damage of small diameter forms voids, which causes the increase of the damage parts of emittance. In addition, bulge damage impedes temperature transfer and reduces emissivity. This method can timely and accurately measure and evaluate the performance state of LIREC and can provide a new idea for the accurate measurement of damage emissivity of LIREC.

EXPERIMENTAL STUDIES OF THE HEATING TEMPERATURE OF THE GREENHOUSE RADIATOR INSTALLATIONS

2020 ◽  
Vol 15 (1) ◽  
pp. 76-80
Author(s):  
Nadezhda Kondrat'eva ◽  
Dmitriy Filatov ◽  
Pavel Terent'ev ◽  
Bulat Ziganshin
Keyword(s):  
Energy Efficiency ◽  
Supply Voltage ◽  
Heating Temperature ◽  
Experimental Studies ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
Voltage Level ◽  
Radiation Sources ◽  
Measurement Results ◽  
Nominal Mode

The thermal regime of plants determines the temperature of the environment, the evaporation of moisture by plants, and the heating of plants by radiation from irradiation plants. Today, induction and LED greenhouse irradiators are promising for replacing irradiators with sodium lamps in terms of energy efficiency. Experimental studies were performed to assess the possibility of proximity of irradiators with induction lamps and LED irradiators to plants to increase their level of irradiation, in comparison with sodium radiation sources. When setting up the experiment, a complex was used, including a Fluke ti32 thermal imager, PHO-250-2-M linear autotransformer, 220V power supply, and a greenhouse irradiator. Processing of the measurement results was carried out in the Fluke SmartView 3.1 program. The heating temperature was determined when reaching the nominal mode, with the nominal mode of operation of the irradiators, with a change in the supply voltage level. Sodium and induction irradiators heat up to a maximum temperature 10 times faster than LED ones. The heating temperature of optical radiation sources with sodium lamps is 5 times higher than LED and 2.5 times higher than induction. A change in the supply voltage level affects the heating temperature of the sodium irradiator with electromagnetic ballasts, the heating temperature of sodium and induction irradiators with electronic ballasts, as well as LED irradiators, remains unchanged and equal to the nominal value at a supply voltage level of ± 10% of Unom.. Low heating temperatures of induction and LED irradiators can reduce the height of their suspension and bring them closer to plants, which will increase the irradiation of plants by increasing the level of illumination or reduce the power of irradiators, that is, increase the energy efficiency of irradiation systems

Modeling and Characterization of the Hydrogenated Amorphous Silicon Metal Insulator Semiconductor Photosensors for Digital Radiography

2007 ◽  
Vol 989 ◽  
Author(s):  
Nader Safavian ◽  
Y. Vygranenko ◽  
J. Chang ◽  
Kyung Ho Kim ◽  
J. Lai ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Spectral Response ◽  
Large Area ◽  
Metal Insulator ◽  
Active Matrix ◽  
High Uniformity ◽  
Measurement Results ◽  
Temperature Deposition ◽  
Hydrogenated Amorphous

AbstractBecause of the inherent desired material and technological attributes such as low temperature deposition and high uniformity over large area, the amorphous silicon (a-Si:H) technology has been extended to digital X-ray diagnostic imaging applications. This paper reports on design, fabrication, and characterization of a MIS-type photosensor that is fully process-compatible with the active matrix a-Si:H TFT backplane. We discuss the device operating principles, along with measurement results of the transient dark current, linearity and spectral response.

scholarly journals Development of a Machine Learning-Based Damage Identification Method Using Multi-Point Simultaneous Acceleration Measurement Results

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2780 ◽  
Author(s):  
Pang-jo Chun ◽  
Tatsuro Yamane ◽  
Shota Izumi ◽  
Naoya Kuramoto
Keyword(s):  
Machine Learning ◽  
Random Forest ◽  
Damage Identification ◽  
Supervised Machine Learning ◽  
Damage Evaluation ◽  
Acceleration Measurement ◽  
Multiple Points ◽  
Measurement Results ◽  
Logarithmic Decay ◽  
Damage Types

It is necessary to assess damage properly for the safe use of a structure and for the development of an appropriate maintenance strategy. Although many efforts have been made to measure the vibration of a structure to determine the degree of damage, the accuracy of evaluation is not high enough, so it is difficult to say that a damage evaluation based on vibrations in a structure has not been put to practical use. In this study, we propose a method to evaluate damage by measuring the acceleration of a structure at multiple points and interpreting the results with a Random Forest, which is a kind of supervised machine learning. The proposed method uses the maximum response acceleration, standard deviation, logarithmic decay rate, and natural frequency to improve the accuracy of damage assessment. We propose a three-step Random Forest method to evaluate various damage types based on the results of these many measurements. Then, the accuracy of the proposed method is verified based on the results of a cross-validation and a vibration test of an actual damaged specimen.

Physically Based Compact Model for Segmented a-Si:H n-i-p Photodiodes

2008 ◽  
Vol 1066 ◽  
Author(s):  
Jeff Hsin Chang ◽  
Timothy Tredwell ◽  
Gregory Heiler ◽  
Yuri Vygranenko ◽  
Denis Striakhilev ◽  
...  
Keyword(s):  
Current Source ◽  
Measurement Data ◽  
Parameter Extraction ◽  
Extraction Process ◽  
Compact Model ◽  
Design Environment ◽  
Large Area ◽  
Measurement Results ◽  
Physically Based ◽  
Flat Panel Detectors

ABSTRACTHydrogenated amorphous silicon (a–Si:H) n–i–p photodiodes are used as pixel sensor elements in large-area flat-panel detectors for medical imaging diagnostics. Accurate model of the sensor plays an imperative role in determining the performances of the detector systems as well as ascertaining design issues prior to production. This work presents the formulation of a compact model for segmented a–Si:H n–i–p photodiodes suitable for circuit-level simulation. The underlining equations of the model are based on device physics where the parameters are extracted from pertinent measurement results of previously fabricated a–Si:H n–i–p photodiodes. Furthermore, the implemented model allows photoresponse simulation with the addition of an external current source. Results of the simulation demonstrated excellent matching with measurement data for different photodiode sizes at various temperatures. The model is implemented in Verilog-A and simulated under Cadence Virtuoso design environment using device geometry and extracted parameters as inputs. The model formulation and parameter extraction process, as well as measurements and simulation results are presented.

Scalable production of ultrafine polyaniline fibres for tactile organic electrochemical transistors

2021 ◽  
Author(s):  
Bo Fang ◽  
Jianmin Yan ◽  
Dan Chang ◽  
Jinli Piao ◽  
Kit Ming Ma ◽  
...  
Keyword(s):  
Conducting Polymer ◽  
Large Scale ◽  
Mechanical Performance ◽  
Small Diameter ◽  
High Energy ◽  
Drawing Ratio ◽  
Driving Voltage ◽  
Large Area ◽  
Friction Forces ◽  
Electrochemical Transistor

Abstract The development of continuous conducting polymer fibres is essential for applications ranging from advanced fibrous devices to frontier fabric electronics. The use of continuous conducting polymer fibres requires a small diameter to maximize their electroactive surfaces, microstructural orientations, and mechanical strengths. However, regularly used wet spinning techniques have rarely achieved this goal due primarily to the insufficient slenderization of rapidly solidified conducting polymer molecules in poor solvents. Here we report a good solvent exchange strategy to wet spin the ultrafine polyaniline fibres at the large scale. The slow diffusion between good solvents distinctly decreases the viscosity of gel protofibers, which undergo an impressive drawing ratio. The continuously collected polyaniline fibres have a previously unattained diameter below 5 µm, high energy and charge storage capacities, and favorable mechanical performance. We demonstrated an ultrathin all-solid organic electrochemical transistor based on ultrafine polyaniline fibres, which substantially amplified microampere drain-source electrical signals with less one volt driving voltage and effectively operated as a tactile sensor detecting pressure and friction forces at different levels. The aggressive electronical and electrochemical merits of ultrafine polyaniline fibres and their great potentials to prepare on industrial scale offer new opportunities for high-performance soft electronics and large-area electronic textiles.

Abrasive-Waterjet Drilling of High Temperature Jet Engine Parts

2009 ◽  
Author(s):  
Mohamed Hashish
Keyword(s):  
Small Diameter ◽  
Substrate Material ◽  
Abrasive Waterjet ◽  
Future Research ◽  
Jet Engines ◽  
Drop Shape ◽  
Drilling Parameters ◽  
Measurement Results ◽  
Additional Processing ◽  
Drilling Time

An experimental investigation was performed to demonstrate the AWJ process capability for precision drilling of small diameter cooling holes in TBC-coated samples and full scale parts used in jet engines. All holes were drilled from the TBC side. Both qualitative and quantitative hole results issues were addressed. These include chipping of TBC, gouging inside the hole at the ceramic-metal interface, feathering at the exit side of the hole, tear drop shape, hole size and its consistency, overall drilling time, and potential systems productivity. It was observed that the AWJ produces high quality holes free from chipping or gouging. However, feathering may occur depending primarily on whether the substrate material is cast or rolled and can be substantially reduced or eliminated by adjusting the drilling parameters. It was also demonstrated that holes of about 0.025-ich can be drilled at 30 with less than 0.001-inch standard deviation. Air flow measurement results have also confirmed that less than 6% variation can be obtained from one set of holes (270 holes) to another. Drilling times below 10 seconds hole to hole were observed for drilling 0.060-inch thick metal substrates with 0.020-inch thick TBC thickness at 30 degrees. This time can be reduced to 3–4 seconds with improved systems. Although AWJ is still slower than laser, produced holes are of superior quality and do not need any additional processing. Future research efforts will focus on improving the drilling time.

scholarly journals Thermal and Multispectral Remote Sensing for the Detection and Analysis of Archaeologically Induced Crop Stress at a UK Site

Drones ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 61
Author(s):  
Katherine James ◽  
Caroline J. Nichol ◽  
Tom Wade ◽  
Dave Cowley ◽  
Simon Gibson Poole ◽  
...  
Keyword(s):  
Data Collection ◽  
Vegetation Index ◽  
Agricultural Practices ◽  
Archaeological Site ◽  
Electromagnetic Spectrum ◽  
Thermal Imager ◽  
Thermal Sensors ◽  
Large Area ◽  
Normalised Difference Vegetation Index

In intensively cultivated landscapes, many archaeological remains are buried under the ploughed soil, and detection depends on crop proxies that express subsurface features. Traditionally these proxies have been documented in visible light as contrasting areas of crop development commonly known as cropmarks. However, it is recognised that reliance on the visible electromagnetic spectrum has inherent limitations on what can be documented, and multispectral and thermal sensors offer the potential to greatly improve our ability to detect buried archaeological features in agricultural fields. The need for this is pressing, as ongoing agricultural practices place many subsurface archaeological features increasingly under threat of destruction. The effective deployment of multispectral and thermal sensors, however, requires a better understanding of when they may be most effective in documenting archaeologically induced responses. This paper presents the first known use of the FLIR Vue Pro-R thermal imager and Red Edge-M for exploring crop response to archaeological features from two UAV surveys flown in May and June 2019 over a known archaeological site. These surveys provided multispectral imagery, which was used to create vegetation index (VI) maps, and thermal maps to assess their effectiveness in detecting crop responses in the temperate Scottish climate. These were visually and statistically analysed using a Mann Whitney test to compare temperature and reflectance values. While the study was compromised by unusually damp conditions which reduced the potential for cropmarking, the VIs (e.g., Normalised Difference Vegetation Index, NDVI) did show potential to detect general crop stress across the study site when they were statistically analysed. This demonstrates the need for further research using multitemporal data collection across case study sites to better understand the interactions of crop responses and sensors, and so define appropriate conditions for large-area data collection. Such a case study-led multitemporal survey approach is an ideal application for UAV-based documentation, especially when “perfect” conditions cannot be guaranteed.

THE HYBRID TRACKING SYSTEM OF ATLAS

2010 ◽  
Vol 25 (08) ◽  
pp. 1519-1540
Author(s):  
LEONARDO ROSSI
Keyword(s):  
Pattern Recognition ◽  
Tracking System ◽  
Radiation Detection ◽  
Small Diameter ◽  
Performance Ratio ◽  
Large Area ◽  
Proton Proton ◽  
Space Resolution ◽  
End Caps ◽  
The Cost

The central tracker of the ATLAS experiment is built using both silicon and gaseous detectors immersed in a 2 T solenoidal magnetic field. To better match the topology of the tracks emerging from the proton–proton collisions, the tracker is separated into a central barrel part (measuring below pseudorapidity |η|≈1.2) and two end-caps (measuring from ≈1.2 to 2.5). Different technologies are used at different radii to optimize the cost–performance ratio. The innermost part, immediately surrounding the beam pipe and up to ≈15 cm , is made up of silicon pixels for best pattern recognition and maximal radiation resistance. The intermediate region (radii from 30 to 60 cm) uses microstrip detectors and provides excellent space resolution over a large area. The outer layer (radii from 60 to 95 cm) is made up of a large number of small diameter drift tubes (straws) which provide good space resolution in the track bending plane and greatly contribute to pattern recognition with multiple measurements. The transition radiation detection capability of this gaseous detector also helps in electron identification.

In-Flight Analysis of Particles in Plasma Spraying

2015 ◽  
Vol 0 (0) ◽  
Author(s):  
Yong Zhang ◽  
Zhi-jiu Ai ◽  
Yan Wu
Keyword(s):  
Flow Field ◽  
Plasma Spraying ◽  
Nozzle Exit ◽  
Initial Conditions ◽  
Small Diameter ◽  
Flight Behavior ◽  
Particle Analysis ◽  
Field Calculation ◽  
Application Process ◽  
Supersonic Plasma

AbstractIn-flight behavior of particles is a key factor that affects the quality of coating. There are some problems such as jet instability and poor coating quality in practical application process. This study focused on internal and external flow characteristics of supersonic plasma spray gun based on the analysis of plasma spraying multi-physical fields. Drag, thermophoretic, and pressure-gradient forces were considered. Flow field calculation and particle analysis were separated. The flow field calculation results were used as the initial conditions of particle computation. Heating and acceleration behavior of particles in the flow field were analyzed. In-flight particles were monitored by Spray Watch and compared with calculated values. Results show that particle velocity and temperature reach the maximum at 80–100 mm away from the nozzle exit. Particles in supersonic plasma spraying are more likely to refine near the nozzle exit, which conforms to experimental observations. The velocity calculation of particles with small diameter is consistent with the measurements.

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