Portable and autonomous X-ray equipment for in-situ threat materials identification by effective atomic number high-accuracy measurement

2011 ◽  
Author(s):  
M. Iovea ◽  
M. Neagu ◽  
G. Mateiasi ◽  
O. Duliu
Keyword(s):  
Atomic Number ◽  
Effective Atomic Number ◽  
High Accuracy ◽  
X Ray ◽  
Accuracy Measurement ◽  
High Accuracy Measurement

A Spectrum-Adaptive Decomposition Method for Effective Atomic Number Estimation Using Dual Energy CT

2020 ◽  
Vol 2020 (14) ◽  
pp. 293-1-293-7
Author(s):  
Ankit Manerikar ◽  
Fangda Li ◽  
Avinash C. Kak
Keyword(s):  
Atomic Number ◽  
Decomposition Method ◽  
Traditional Approach ◽  
Effective Atomic Number ◽  
Dual Energy ◽  
Performance Comparison ◽  
Estimation Methods ◽  
Dual Energy Ct ◽  
Projection Data ◽  
X Ray

Dual Energy Computed Tomography (DECT) is expected to become a significant tool for voxel-based detection of hazardous materials in airport baggage screening. The traditional approach to DECT imaging involves collecting the projection data using two different X-ray spectra and then decomposing the data thus collected into line integrals of two independent characterizations of the material properties. Typically, one of these characterizations involves the effective atomic number (Zeff) of the materials. However, with the X-ray spectral energies typically used for DECT imaging, the current best-practice approaches for dualenergy decomposition yield Zeff values whose accuracy range is limited to only a subset of the periodic-table elements, more specifically to (Z < 30). Although this estimation can be improved by using a system-independent ρe — Ze (SIRZ) space, the SIRZ transformation does not efficiently model the polychromatic nature of the X-ray spectra typically used in physical CT scanners. In this paper, we present a new decomposition method, AdaSIRZ, that corrects this shortcoming by adapting the SIRZ decomposition to the entire spectrum of an X-ray source. The method reformulates the X-ray attenuation equations as direct functions of (ρe, Ze) and solves for the coefficients using bounded nonlinear least-squares optimization. Performance comparison of AdaSIRZ with other Zeff estimation methods on different sets of real DECT images shows that AdaSIRZ provides a higher output accuracy for Zeff image reconstructions for a wider range of object materials.

High accuracy measurement of the ground-state hyperfine splitting in a 113Cd+ microwave clock: erratum

2021 ◽  
Vol 46 (20) ◽  
pp. 5207
Author(s):  
K. Miao ◽  
J. W. Zhang ◽  
X. L. Sun ◽  
S. G. Wang ◽  
A. M. Zhang ◽  
...  
Keyword(s):  
Ground State ◽  
Hyperfine Splitting ◽  
High Accuracy ◽  
Accuracy Measurement ◽  
High Accuracy Measurement

scholarly journals High Accuracy Measurement of Total Losses in Fractional Horsepower Induction Motors

2015 ◽  
Vol 1 (2) ◽  
pp. 13
Author(s):  
Azzeddine Ferrah ◽  
Mounir Bouzguenda ◽  
Jehad M. Al-Khalaf Bani Younis
Keyword(s):  
Single Phase ◽  
Induction Motors ◽  
Data Acquisition System ◽  
High Accuracy ◽  
Industrial Applications ◽  
Motor Speed ◽  
Accuracy Measurement ◽  
Three Phase ◽  
Better Than ◽  
High Accuracy Measurement

Large and small single-phase and three-phase induction motors are commonly used in industrial applications. The present work represents an attempt towards the design of a high accuracy system for the measurement of fractional horsepower (FHP) induction motor losses and efficiency. The calorimeter designed and built is capable of measuring heat losses of up to 1 kW with an overall accuracy better than 3%. During all tests, ambient temperature, humidity, motor speed and motor frame temperature were recorded using precise digital instruments. The inlet, outlet temperatures and resulting losses were recorded automatically using a high accuracy 12-bit data acquisition system. The preliminary results obtained demonstrate the suitability of the designed calorimeter for the accurate measurement of losses in FHP induction motors.

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