Measurement accuracy and Cerenkov removal for high performance, high spatial resolution scintillation dosimetry

2005 ◽  
Vol 33 (1) ◽  
pp. 128-135 ◽  
Author(s):  
Louis Archambault ◽  
A. Sam Beddar ◽  
Luc Gingras ◽  
René Roy ◽  
Luc Beaulieu
Keyword(s):  
Spatial Resolution ◽  
High Performance ◽  
Measurement Accuracy ◽  
High Spatial Resolution

scholarly journals High Performance Molecular Imaging with MALDI Trapped Ion Mobility Time-of-Flight (timsTOF) Mass Spectrometry

2019 ◽  
Author(s):  
Jeffrey Spraggins ◽  
Katerina Djambazova ◽  
Emilio Rivera ◽  
Lukasz Migas ◽  
Elizabeth Neumann ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Imaging ◽  
Spatial Resolution ◽  
Ion Mobility ◽  
Measurement Errors ◽  
High Performance ◽  
High Spatial Resolution ◽  
Biological Tissues ◽  
Whole Body ◽  
Trapped Ion

Imaging mass spectrometry (IMS) enables the spatially targeted molecular assessment of biological tissues at cellular resolutions. New developments and technologies are essential for uncovering the molecular drivers of native physiological function and disease. Instrumentation must maximize spatial resolution, throughput, sensitivity, and specificity, because tissue imaging experiments consist of thousands to millions of pixels. Here, we report the development and application of a matrix-assisted laser desorption/ionization (MALDI) trapped ion mobility spectrometry imaging platform. This prototype MALDI timsTOF instrument is capable of 10 µm spatial resolutions and 20 pixels/s throughput molecular imaging. The MALDI source utilizes a Bruker SmartBeam 3-D laser system that can generate a square burn pattern of <10 x 10 µm at the sample surface. General image performance was assessed using murine kidney and brain tissues and demonstrate that high spatial resolution imaging data can be generated rapidly with mass measurement errors < 5 ppm and ~40,000 resolving power. Initial TIMS-based imaging experiments were performed on whole body mouse pup tissue demonstrating the separation of closely isobaric [PC(32:0)+Na]<sup>+</sup>and [PC(34:3)+H]<sup>+</sup>(3 mDa mass difference) in the gas-phase. We have shown that the MALDI timsTOF platform can maintain reasonable data acquisition rates (>2 pixels/s) while providing the specificity necessary to differentiate components in complex mixtures of lipid adducts. The combination of high spatial resolution and throughput imaging capabilities with high-performance TIMS separations provides a uniquely tunable platform to address many challenges associated with advanced molecular imaging applications.

High Performance Molecular Imaging with MALDI Trapped Ion Mobility Time-of-Flight (timsTOF) Mass Spectrometry

2019 ◽  
Author(s):  
Jeffrey Spraggins ◽  
Katerina Djambazova ◽  
Emilio Rivera ◽  
Lukasz Migas ◽  
Elizabeth Neumann ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Imaging ◽  
Spatial Resolution ◽  
Ion Mobility ◽  
Measurement Errors ◽  
High Performance ◽  
High Spatial Resolution ◽  
Biological Tissues ◽  
Whole Body ◽  
Trapped Ion

Imaging mass spectrometry (IMS) enables the spatially targeted molecular assessment of biological tissues at cellular resolutions. New developments and technologies are essential for uncovering the molecular drivers of native physiological function and disease. Instrumentation must maximize spatial resolution, throughput, sensitivity, and specificity, because tissue imaging experiments consist of thousands to millions of pixels. Here, we report the development and application of a matrix-assisted laser desorption/ionization (MALDI) trapped ion mobility spectrometry imaging platform. This prototype MALDI timsTOF instrument is capable of 10 µm spatial resolutions and 20 pixels/s throughput molecular imaging. The MALDI source utilizes a Bruker SmartBeam 3-D laser system that can generate a square burn pattern of <10 x 10 µm at the sample surface. General image performance was assessed using murine kidney and brain tissues and demonstrate that high spatial resolution imaging data can be generated rapidly with mass measurement errors < 5 ppm and ~40,000 resolving power. Initial TIMS-based imaging experiments were performed on whole body mouse pup tissue demonstrating the separation of closely isobaric [PC(32:0)+Na]<sup>+</sup>and [PC(34:3)+H]<sup>+</sup>(3 mDa mass difference) in the gas-phase. We have shown that the MALDI timsTOF platform can maintain reasonable data acquisition rates (>2 pixels/s) while providing the specificity necessary to differentiate components in complex mixtures of lipid adducts. The combination of high spatial resolution and throughput imaging capabilities with high-performance TIMS separations provides a uniquely tunable platform to address many challenges associated with advanced molecular imaging applications.

scholarly journals Using LiF crystals for high-performance neutron imaging with micron-scale resolution

2015 ◽  
Vol 3 ◽  
Author(s):  
A. Faenov ◽  
M. Matsubayashi ◽  
T. Pikuz ◽  
Y. Fukuda ◽  
M. Kando ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Linear Response ◽  
High Performance ◽  
Dynamic Range ◽  
High Spatial Resolution ◽  
Neutron Imaging ◽  
Optically Stimulated Luminescence ◽  
Plasma Sources ◽  
Imaging Detector ◽  
Z Pinch

This paper describes an overview of our recent discovery – clear demonstration that LiF crystals can be efficiently used as a high-performance neutron imaging detector based on optically stimulated luminescence of color centers generated by neutron irradiation. It is shown that the neutron images we have obtained are almost free from granular noise, have a spatial resolution of ${\sim}5.4~{\rm\mu}\text{m}$ and a linear response with a dynamic range of at least $10^{3}$ . The high contrast and good sensitivity of LiF crystals allow us to distinguish two holes with less than 2% transmittance difference. We propose to use such detectors in areas where high spatial resolution with high image gradation resolution is needed, including diagnostics of different plasma sources such as laser and z-pinch produced plasmas.

scholarly journals Improving GNSS-R Sea Surface Altimetry Precision Based on the Novel Dual Circularly Polarized Phased Array Antenna Model

2021 ◽  
Vol 13 (15) ◽  
pp. 2974
Author(s):  
Zhen Cui ◽  
Wei Zheng ◽  
Fan Wu ◽  
Xiaoping Li ◽  
Cheng Zhu ◽  
...  
Keyword(s):  
High Precision ◽  
Spatial Resolution ◽  
Measurement Accuracy ◽  
Phased Array ◽  
High Spatial Resolution ◽  
Beam Width ◽  
Sea Surface ◽  
Antenna Gain ◽  
Phased Array Antenna ◽  
Circularly Polarized

Antenna is one of the key payloads of the GNSS-R system, and the gain is an important performance parameter. The signal-to-noise ratio (SNR) of the received signal can be improved by increasing the gain of the GNSS-R antenna, therefore the measurement accuracy is improved. However, the antenna gain and its beam width, these two performance parameters, are contradictory. If the gain of the antenna is increased, its beam width will inevitably become narrower. This narrowed beam width will affect the width of the survey strip for the GNSS-R system, which cannot meet the requirement of the high-precision and high-spatial resolution spaceborne GNSS-R sea surface altimetry in the future. In this paper, a novel dual circularly polarized phased array antenna (NDCPPA) is proposed and investigated. First, the GNSS-R satellites currently operating in orbit are all cGNSS-R systems, which use the traditional element antenna (TEA) method for measurement. The antenna used in this method is with low gain, which limits the improvement of sea surface measurement accuracy. In response to this problem, this paper establishes an NDCPPA model of iGNSS-R measurement system based on the theory of coherent signal processing on the sea surface. This model uses the high-gain scanning beam to increase the gain of the iGNSS-R antenna without affecting its coverage area, thereby improving the sea surface altimetry precision. Second, in order to verify the gain improvement effect brought by adopting the NDCPPA model, an NDCPPA model verification prototype for iGNSS-R sea surface altimetry was designed and fabricated, and then measured in a microwave anechoic chamber. The measurement results show that, compared with the TEA method, the antenna gain of our proposed verification prototype is enhanced by 9.5 dB. And the measured and designed value of the gain of the verification prototype matches well. Third, based on the GPS L1 signal, the NDCPPA model is used to analyze the effect of improving the precision of sea surface altimetry. Compared with the TEA method, the proposed model can increase the altimetric precision of the nadir point from 7.27 m to 0.21 m, which effectively improves the performance of the iGNSS-R altimetry. The NDCPPA model proposed in this article can provide the theoretical method basis and the crucial technical support for the future high-precision and high-spatial-resolution GNSS-R sea surface altimetry verification satellite.

High Performance Molecular Imaging with MALDI Trapped Ion Mobility Time-of-Flight (timsTOF) Mass Spectrometry

2019 ◽  
Author(s):  
Jeffrey Spraggins ◽  
Katerina Djambazova ◽  
Emilio Rivera ◽  
Lukasz Migas ◽  
Elizabeth Neumann ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Imaging ◽  
Spatial Resolution ◽  
Ion Mobility ◽  
Measurement Errors ◽  
High Performance ◽  
High Spatial Resolution ◽  
Biological Tissues ◽  
Whole Body ◽  
Trapped Ion

Imaging mass spectrometry (IMS) enables the spatially targeted molecular assessment of biological tissues at cellular resolutions. New developments and technologies are essential for uncovering the molecular drivers of native physiological function and disease. Instrumentation must maximize spatial resolution, throughput, sensitivity, and specificity, because tissue imaging experiments consist of thousands to millions of pixels. Here, we report the development and application of a matrix-assisted laser desorption/ionization (MALDI) trapped ion mobility spectrometry imaging platform. This prototype MALDI timsTOF instrument is capable of 10 µm spatial resolutions and 20 pixels/s throughput molecular imaging. The MALDI source utilizes a Bruker SmartBeam 3-D laser system that can generate a square burn pattern of <10 x 10 µm at the sample surface. General image performance was assessed using murine kidney and brain tissues and demonstrate that high spatial resolution imaging data can be generated rapidly with mass measurement errors < 5 ppm and ~40,000 resolving power. Initial TIMS-based imaging experiments were performed on whole body mouse pup tissue demonstrating the separation of closely isobaric [PC(32:0)+Na]<sup>+</sup>and [PC(34:3)+H]<sup>+</sup>(3 mDa mass difference) in the gas-phase. We have shown that the MALDI timsTOF platform can maintain reasonable data acquisition rates (>2 pixels/s) while providing the specificity necessary to differentiate components in complex mixtures of lipid adducts. The combination of high spatial resolution and throughput imaging capabilities with high-performance TIMS separations provides a uniquely tunable platform to address many challenges associated with advanced molecular imaging applications.

scholarly journals Deep Convolutional Neural Networks for Automated Characterization of Arctic Ice-Wedge Polygons in Very High Spatial Resolution Aerial Imagery

2018 ◽  
Vol 10 (9) ◽  
pp. 1487 ◽  
Author(s):  
Weixing Zhang ◽  
Chandi Witharana ◽  
Anna Liljedahl ◽  
Mikhail Kanevskiy
Keyword(s):  
Spatial Resolution ◽  
High Performance ◽  
High Spatial Resolution ◽  
Global Climate ◽  
Machine Learning Techniques ◽  
Deep Convolutional Neural Networks ◽  
Very High Spatial Resolution ◽  
Ice Wedge ◽  
Arctic Ice ◽  
Very High

The microtopography associated with ice-wedge polygons governs many aspects of Arctic ecosystem, permafrost, and hydrologic dynamics from local to regional scales owing to the linkages between microtopography and the flow and storage of water, vegetation succession, and permafrost dynamics. Wide-spread ice-wedge degradation is transforming low-centered polygons into high-centered polygons at an alarming rate. Accurate data on spatial distribution of ice-wedge polygons at a pan-Arctic scale are not yet available, despite the availability of sub-meter-scale remote sensing imagery. This is because the necessary spatial detail quickly produces data volumes that hamper both manual and semi-automated mapping approaches across large geographical extents. Accordingly, transforming big imagery into ‘science-ready’ insightful analytics demands novel image-to-assessment pipelines that are fueled by advanced machine learning techniques and high-performance computational resources. In this exploratory study, we tasked a deep-learning driven object instance segmentation method (i.e., the Mask R-CNN) with delineating and classifying ice-wedge polygons in very high spatial resolution aerial orthoimagery. We conducted a systematic experiment to gauge the performances and interoperability of the Mask R-CNN across spatial resolutions (0.15 m to 1 m) and image scene contents (a total of 134 km2) near Nuiqsut, Northern Alaska. The trained Mask R-CNN reported mean average precisions of 0.70 and 0.60 at thresholds of 0.50 and 0.75, respectively. Manual validations showed that approximately 95% of individual ice-wedge polygons were correctly delineated and classified, with an overall classification accuracy of 79%. Our findings show that the Mask R-CNN is a robust method to automatically identify ice-wedge polygons from fine-resolution optical imagery. Overall, this automated imagery-enabled intense mapping approach can provide a foundational framework that may propel future pan-Arctic studies of permafrost thaw, tundra landscape evolution, and the role of high latitudes in the global climate system.

scholarly journals Dimension Reduction Using Quantum Wavelet Transform on a High-Performance Reconfigurable Computer

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Naveed Mahmud ◽  
Esam El-Araby
Keyword(s):  
Wavelet Transform ◽  
High Resolution ◽  
Spatial Resolution ◽  
Particle Tracking ◽  
High Performance ◽  
High Energy Physics ◽  
High Spatial Resolution ◽  
High Energy ◽  
Resolution Data ◽  
Energy Physics

The high resolution of multidimensional space-time measurements and enormity of data readout counts in applications such as particle tracking in high-energy physics (HEP) is becoming nowadays a major challenge. In this work, we propose combining dimension reduction techniques with quantum information processing for application in domains that generate large volumes of data such as HEP. More specifically, we propose using quantum wavelet transform (QWT) to reduce the dimensionality of high spatial resolution data. The quantum wavelet transform takes advantage of the principles of quantum mechanics to achieve reductions in computation time while processing exponentially larger amount of information. We develop simpler and optimized emulation architectures than what has been previously reported, to perform quantum wavelet transform on high-resolution data. We also implement the inverse quantum wavelet transform (IQWT) to accurately reconstruct the data without any losses. The algorithms are prototyped on an FPGA-based quantum emulator that supports double-precision floating-point computations. Experimental work has been performed using high-resolution image data on a state-of-the-art multinode high-performance reconfigurable computer. The experimental results show that the proposed concepts represent a feasible approach to reducing dimensionality of high spatial resolution data generated by applications such as particle tracking in high-energy physics.

High spatial resolution AEM observations of yttrium segregation in chromia scales grown on Co-45%Cr

1986 ◽  
Vol 44 ◽  
pp. 518-519
Author(s):  
K. Przybylski ◽  
A. J. Garratt-Reed ◽  
G. J. Yurek
Keyword(s):  
Spatial Resolution ◽  
Outer Surface ◽  
Maximum Concentration ◽  
High Spatial Resolution ◽  
Reactive Elements ◽  
Chromia Scales

The addition of so-called “reactive” elements such as yttrium to alloys is known to enhance the protective nature of Cr2O3 or Al2O3 scales. However, the mechanism by which this enhancement is achieved remains unclear. An A.E.M. study has been performed of scales grown at 1000°C for 25 hr. in pure O2 on Co-45%Cr implanted at 70 keV with 2x1016 atoms/cm2 of yttrium. In the unoxidized alloys it was calculated that the maximum concentration of Y was 13.9 wt% at a depth of about 17 nm. SIMS results showed that in the scale the yttrium remained near the outer surface.

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