Positron Emission Particle Tracking of Granular Flows

2020 ◽  
Vol 11 (1) ◽  
pp. 367-396 ◽  
Author(s):  
C.R.K. Windows-Yule ◽  
J.P.K. Seville ◽  
A. Ingram ◽  
D.J. Parker
Keyword(s):  
Spatial Resolution ◽  
Particle Tracking ◽  
Three Dimensional ◽  
Granular Flows ◽  
Noninvasive Technique ◽  
Diverse Range ◽  
Industrial Systems ◽  
Positron Emission ◽  
Temporal And Spatial

Positron emission particle tracking (PEPT) is a noninvasive technique capable of imaging the three-dimensional dynamics of a wide variety of powders, particles, grains, and/or fluids. The PEPT technique can track the motion of particles with high temporal and spatial resolution and can be used to study various phenomena in systems spanning a broad range of scales, geometries, and physical states. We provide an introduction to the PEPT technique, an overview of its fundamental principles and operation, and a brief review of its application to a diverse range of scientific and industrial systems.

scholarly journals Successive filament eruptions within one solar breakout event

2013 ◽  
Vol 8 (S300) ◽  
pp. 231-234
Author(s):  
Yuandeng Shen
Keyword(s):  
Structural Properties ◽  
Spatial Resolution ◽  
Source Region ◽  
Three Dimensional ◽  
Magnetic Topology ◽  
Magnetic Source ◽  
Physical Linkage ◽  
Temporal And Spatial ◽  
Coronal Field

AbstractThe magnetic breakout model has been widely used to explain solar eruptive activities. Here, we apply it to explain successive filament eruptions occurred in a quadrupolar magnetic source region. Based on the high temporal and spatial resolution, multi-wavelengths observations taken by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO), we find some signatures that support the occurrence of breakout-like external reconnection just before the start of the successive filament eruptions. Furthermore, the extrapolated three-dimensional coronal field also reveals that the magnetic topology above the quadrupolar source region resembles that of the breakout model. We propose a possible mechanism within the framework of the breakout model to interpret the successive filament eruptions, in which the so-called magnetic implosion mechanism is firstly introduced to be the physical linkage of successive filament eruptions. We conclude that the structural properties of coronal fields are important for producing successive filament eruptions.

Python-Based Supercell Tracking for Coarse Temporal and Spatial Resolution Numerical Model Simulations

2021 ◽  
Author(s):  
Matthew E. Gropp ◽  
Casey E. Davenport
Keyword(s):  
Open Source ◽  
Spatial Resolution ◽  
Climate Model ◽  
Regional Climate ◽  
Three Dimensional ◽  
Model Verification ◽  
Tracking Algorithm ◽  
Data Availability ◽  
Source Tracking ◽  
Temporal And Spatial

AbstractDeep convective thunderstorm tracking methodologies and software have become useful and necessary tools across many applications, from nowcasting to model verification. Despite many available options, many of these pre-existing methods lack a customizable, fast, and flexible methodology that can track supercell thunderstorms within convective-allowing climate datasets with coarse temporal and spatial resolution. This project serves as one option to solve this issue via an all-in-one tracking methodology, built upon several open-source Python libraries, and designed to work with various temporal resolutions, including hourly. Unique to this approach is accounting for varying data availability of different model variables, while still sufficiently and accurately tracking specific convective features; in this case, supercells were the focus. To help distinguish supercells from ordinary cells, updraft helicity and other three-dimensional atmospheric data were incorporated into the tracking algorithm to confirm its supercellular status. Deviant motion from the mean wind was also used identify supercells. The tracking algorithm was tested and performed on a dynamically-downscaled regional climate model dataset with 4 km horizontal grid spacing. Each supercell was tracked for its entire lifetime over the course of 26 years of model output, resulting in a supercell climatology over the central United States. Due to the tracking configuration and dataset used, the tracking performs most consistently for long-lived and strong supercells compared to weak and short-lived supercells. This tracking methodology allows for customizable open-source tracking of supercells in any downscaled convective-allowing dataset, even with coarse temporal resolution.

scholarly journals Three-dimensional spatiotemporal tracking of fluorine-18 radiolabeled yeast cells via positron emission particle tracking

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0180503 ◽  
Author(s):  
Seth T. Langford ◽  
Cody S. Wiggins ◽  
Roque Santos ◽  
Melinda Hauser ◽  
Jeffrey M. Becker ◽  
...  
Keyword(s):  
Particle Tracking ◽  
Three Dimensional ◽  
Yeast Cells ◽  
Positron Emission

scholarly journals Time Resolved 3D MRA. Applications for Interventional Neuroradiology

2006 ◽  
Vol 12 (3) ◽  
pp. 223-231 ◽  
Author(s):  
CP Stracke ◽  
E. Spuentrup ◽  
P. Reinacher ◽  
A. Thron ◽  
T. Krings
Keyword(s):  
Spatial Resolution ◽  
Parallel Imaging ◽  
Three Dimensional ◽  
Interventional Neuroradiology ◽  
Structural Mri ◽  
Vascular Lesion ◽  
Whole Body ◽  
Time Resolved ◽  
Hemodynamic Characteristics ◽  
Temporal And Spatial

The decision for endovascular treatment of cranial dural AV fistulae and angiomas and their follow-up after treatment is usually based on conventional DSA. New techniques of magnetic resonance angiography (MRA) facilitate high temporal and spatial resolution images. The purpose of this study was to evaluate the applicability and clinical use of a newly developed 3D dynamic MRA protocol on a 3T scanner for neurointerventional planning and decision-making. Using a 3T whole body scanner, a three-dimensional dynamic contrast enhanced MRA sequence with parallel imaging, and intelligent k-space readout (Keyhole and “CENTRA” k-space filling) was added to structural MRI and time-of-flight MRA in seven patients. DSA was performed in each patient following MR examination. In all patients MRA allowed the identification and correct classification of the vascular lesion. Hemodynamic characteristics and venous architecture were clearly demonstrated. Larger feeding arteries could be identified in all cases. Smaller feeding vessels were overlooked in dynamic MRA and only depicted in conventional DSA High temporal and spatial resolution 3D MRA may correctly identify and classify fistulae and angiomas and help to reduce the number of pre- or post-interventional invasive diagnostic angiograms.

Recent Advances in Positron Emission Particle Tracking: A Comparative Review

2021 ◽  
Author(s):  
Christopher R. K. Windows-Yule ◽  
Matthew Herald ◽  
Leonard Nicusan ◽  
Cody Wiggins ◽  
Guillem Pratx ◽  
...  
Keyword(s):  
High Resolution ◽  
Open Source ◽  
Particle Tracking ◽  
Quantitative Assessment ◽  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Positron Emission ◽  
Comparative Review ◽  
Multiphase Systems ◽  
First Time

Abstract Positron emission particle tracking (PEPT) is a technique which allows the high-resolution, three-dimensional imaging of particulate and multiphase systems, including systems which are large, dense, and/or optically opaque, and thus difficult to study using other methodologies. In this work, we bring together researchers from the world's foremost PEPT facilities not only to give a balanced and detailed overview and review of the technique but, for the first time, provide a rigorous, direct, quantitative assessment of the relative strengths and weaknesses of all contemporary PEPT methodologies. We provide detailed explanations of the methodologies explored, including also interactive code examples allowing the reader to actively explore, edit and apply the algorithms discussed. The suite of benchmarking tests performed and described within the document is made available in an open-source repository for future researchers.

Visualisation of three-dimensional flows in rotating cans using positron emission particle tracking (PEPT)

2003 ◽  
Vol 60 (3) ◽  
pp. 229-240 ◽  
Author(s):  
P.W. Cox ◽  
S. Bakalis ◽  
H. Ismail ◽  
R. Forster ◽  
D.J. Parker ◽  
...  
Keyword(s):  
Particle Tracking ◽  
Three Dimensional ◽  
Positron Emission

scholarly journals Semi-automated classification of colonial Microcystis by FlowCAM imaging flow cytometry in mesocosm experiment reveals high heterogeneity during seasonal bloom

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yersultan Mirasbekov ◽  
Adina Zhumakhanova ◽  
Almira Zhantuyakova ◽  
Kuanysh Sarkytbayev ◽  
Dmitry V. Malashenkov ◽  
...  
Keyword(s):  
Machine Learning ◽  
Flow Cytometry ◽  
Spatial Resolution ◽  
Mesocosm Experiment ◽  
Imaging Flow Cytometry ◽  
Leibler Divergence ◽  
Temporal And Spatial ◽  
High Level ◽  
Training Sets

AbstractA machine learning approach was employed to detect and quantify Microcystis colonial morphospecies using FlowCAM-based imaging flow cytometry. The system was trained and tested using samples from a long-term mesocosm experiment (LMWE, Central Jutland, Denmark). The statistical validation of the classification approaches was performed using Hellinger distances, Bray–Curtis dissimilarity, and Kullback–Leibler divergence. The semi-automatic classification based on well-balanced training sets from Microcystis seasonal bloom provided a high level of intergeneric accuracy (96–100%) but relatively low intrageneric accuracy (67–78%). Our results provide a proof-of-concept of how machine learning approaches can be applied to analyze the colonial microalgae. This approach allowed to evaluate Microcystis seasonal bloom in individual mesocosms with high level of temporal and spatial resolution. The observation that some Microcystis morphotypes completely disappeared and re-appeared along the mesocosm experiment timeline supports the hypothesis of the main transition pathways of colonial Microcystis morphoforms. We demonstrated that significant changes in the training sets with colonial images required for accurate classification of Microcystis spp. from time points differed by only two weeks due to Microcystis high phenotypic heterogeneity during the bloom. We conclude that automatic methods not only allow a performance level of human taxonomist, and thus be a valuable time-saving tool in the routine-like identification of colonial phytoplankton taxa, but also can be applied to increase temporal and spatial resolution of the study.

Potential of Arabic documentary sources for reconstructing past climate in the western Mediterranean region from AD 680 to 1815

The Holocene ◽  
2021 ◽  
pp. 095968362110332
Author(s):  
Yassin Meklach ◽  
Chantal Camenisch ◽  
Abderrahmane Merzouki ◽  
Ricardo Garcia Herrera
Keyword(s):  
Spatial Resolution ◽  
Mediterranean Region ◽  
Climate Extremes ◽  
Western Mediterranean ◽  
Historical Documents ◽  
Atmospheric Conditions ◽  
Documentary Sources ◽  
Drought Conditions ◽  
Temporal And Spatial ◽  
Climate Proxies

Archival records and historical documents offer direct observation of weather and atmospheric conditions and have the highest temporal and spatial resolution, and precise dating, of the available climate proxies. They also provide information about variables such as temperature, precipitation and climate extremes, as well as floods, droughts and storms. The present work studied Arab-Islamic documentary sources covering the western Mediterranean region (documents written by Arab-Islamic historians that narrate social, political and religious history) available for the period AD 680–1815. They mostly provide information on hydrometeorological events. In Iberia the most intense droughts were reported during AD 747–753, AD 814–822, AD 846–847, AD 867–874 and AD 914–915 and in the Maghreb AD 867–873, AD 898–915, AD 1104–1147, AD 1280–1340 and AD 1720–1815 had prevalent drought conditions. Intense rain episodes are also reported.

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