Nonlinear imaging of damage in composite structures using sparse ultrasonic sensor arrays

2016 ◽  
Vol 24 (5) ◽  
pp. e1911 ◽  
Author(s):  
F. Ciampa ◽  
Simon G. Pickering ◽  
Gennaro Scarselli ◽  
M. Meo
Keyword(s):  
Composite Structures ◽  
Sensor Arrays ◽  
Ultrasonic Sensor ◽  
Nonlinear Imaging

UNDERWATER GROUND MAPPING FOR FLOOD DISASTER USING ULTRASONIC SENSOR

2016 ◽  
Vol 78 (7-4) ◽  
Author(s):  
Salman Sayyidi Hamzah ◽  
Mohd Hafiz Fazalul Rahiman ◽  
Mohd Hajazi Mustafa ◽  
Mohd Azrul Amat ◽  
Lean Thiam Siow ◽  
...  
Keyword(s):  
Current Flow ◽  
Sensor Arrays ◽  
Current Method ◽  
Ultrasonic Sensor ◽  
Flood Disaster ◽  
Depth Information ◽  
Water Tank ◽  
Guide Line ◽  
Flood Current ◽  
The Right

Search and Rescue (SAR) team used dip stick to measure the water depth and identify the badly eroded area and a guide line will be placed to assist them. However, ground erosion is unpredictable coupled with unknown sizes make the SAR task more difficult thus posing grave danger to SAR team in action. Therefore, this current method is no longer reliable because the flood current will swipe it away and rendered the guide line to be unfeasible over time consuming. A system proposed in this study was developed using ultrasonic sensor array to reconstruct the ground map in flood area. It consists of several sensor arrays to collect the underwater depth information and convert them into mapping data before relaying them to ground station. The results then will help the SAR team to identify the safe path to reach for the flood victims. The factor to focus on is the depth of the flood, the current flow and the medium that the wave will go through. The current flow will be the main threat because the sensor needs to be on the right angle to get the accurate reading. The data then will be transfer to excel to start the mapping for underwater ground. Based on the result from the prototype testing conducted using water tank, sensors can be installed to get wider map view and mapping can be improved by using multi-angle shapes for it to be more accurate in flood disaster. 

scholarly journals Space-Filling Curve Resistor on Ultra-Thin Polyetherimide Foil for Strain Impervious Temperature Sensing

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6479 ◽  
Author(s):  
Korbinian Rager ◽  
David Jaworski ◽  
Chresten von der Heide ◽  
Alexander Kyriazis ◽  
Michael Sinapius ◽  
...  
Keyword(s):  
Temperature Sensor ◽  
Composite Structures ◽  
Sensor Arrays ◽  
Operational Reliability ◽  
Space Filling ◽  
Initial Product ◽  
Space Filling Curve ◽  
Structural Health ◽  
Filling Curve ◽  
Foil Substrate

Monitoring process parameters in the manufacture of composite structures is key to ensuring product quality and safety. Ideally, this can be done by sensors that are embedded during production and can remain as devices to monitor structural health. Extremely thin foil-based sensors weaken the finished workpiece very little. Under ideal conditions, the foil substrate bonds with the resin in the autoclaving process, as is the case when polyetherimide is used. Here, we present a temperature sensor as part of an 8 µm thick multi-sensor node foil for monitoring processing conditions during the production and structural health during the lifetime of a construction. A metallic thin film conductor was shaped in the form of a space-filling curve to suppress the influences of resistance changes due to strain, which could otherwise interfere with the measurement of the temperature. FEM simulations as well as experiments confirm that this type of sensor is completely insensitive to the direction of strain and sufficiently insensitive to the amount of strain, so that mechanical strains that can occur in the composite curing process practically do not interfere with the temperature measurement. The temperature sensor is combined with a capacitive sensor for curing monitoring based on impedance measurement and a half-bridge strain gauge sensor element. All three types are made of the same materials and are manufactured together in one process flow. This is the key to cost-effective distributed sensor arrays that can be embedded during production and remain in the workpiece, thus ensuring not only the quality of the initial product but also the operational reliability during the service life of light-weight composite constructions.

The design and test of MEMS piezoresistive ultrasonic sensor arrays

2013 ◽  
Vol 34 (3) ◽  
pp. 034007 ◽  
Author(s):  
Deqin Lian ◽  
Changde He ◽  
Hui Zhang ◽  
Jiaqi Yu ◽  
Kejing Yuan ◽  
...  
Keyword(s):  
Sensor Arrays ◽  
Ultrasonic Sensor

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Image formation analysis of thick biological specimens using three-dimensional power-spectra of through focus series

1994 ◽  
Vol 52 ◽  
pp. 124-125
Author(s):  
Karen F. Han
Keyword(s):  
Inelastic Scattering ◽  
Imaging Techniques ◽  
Mass Density ◽  
Relative Proportion ◽  
Three Dimensional ◽  
Power Spectra ◽  
Image Formation ◽  
Energy Filtering ◽  
Ewald Sphere ◽  
Nonlinear Imaging

The primary focus in our laboratory is the study of higher order chromatin structure using three dimensional electron microscope tomography. Three dimensional tomography involves the deconstruction of an object by combining multiple projection views of the object at different tilt angles, image intensities are not always accurate representations of the projected object mass density, due to the effects of electron-specimen interactions and microscope lens aberrations. Therefore, an understanding of the mechanism of image formation is important for interpreting the images. The image formation for thick biological specimens has been analyzed by using both energy filtering and Ewald sphere constructions. Surprisingly, there is a significant amount of coherent transfer for our thick specimens. The relative amount of coherent transfer is correlated with the relative proportion of elastically scattered electrons using electron energy loss spectoscopy and imaging techniques.Electron-specimen interactions include single and multiple, elastic and inelastic scattering. Multiple and inelastic scattering events give rise to nonlinear imaging effects which complicates the interpretation of collected images.

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