A High Speed Particle Phase Discriminator (PPD-HS) for the classification of airborne particles, as tested in a continuous flow diffusion chamber by Mahrt et al.

Abstract. A new instrument, the High Speed Particle Phase Discriminator (PPD-HS) developed at the University of Hertfordshire, for sizing individual cloud hydrometeors and determining their phase is described herein. PPD-HS performs an in-situ analysis of the spatial intensity distribution of near forward scattered light for individual hydrometeors yielding shape properties. Discrimination of spherical and aspherical particles is based on an analysis of the symmetry of the recorded scattering patterns. Scattering patterns are collected onto two linear detector arrays, reducing the complete 2D scattering pattern to scattered light intensities captured onto two linear, one dimensional strips of light sensitive pixels. Using this reduced scattering information, we calculate symmetry indicators that are used for particle shape and ultimately phase analysis. This reduction of information allows for detection rates of a few hundred particles per second. Here, we present a comprehensive analysis of instrument performance using both spherical and aspherical particles, generated in a well-controlled laboratory setting using a Vibrating Orifice Aerosol Generator (VOAG) and covering a size range of approximately 3–32 micron. We use supervised machine learning to train a random forest model on the VOAG data sets that can be used to classify any particles detected by PPD-HS. Classification results show that the PPD-HS can successfully discriminate between spherical and aspherical particles, with misclassification below 5 % for diameters > 3 micro meter. This phase discrimination method is subsequently applied to classify simulated cloud particles produced in a continuous flow diffusion chamber setup. We report observations of small, near-spherical ice crystals at early stages of the ice nucleation experiments, where shape analysis fails to correctly determine the particle phase. Nevertheless, in case of simultaneous presence of cloud droplets and ice crystals, the introduced particle shape indicators allow for a clear distinction between these two classes independent of optical particle size. We conclude that PPD-HS constitutes a powerful new instrument to size and discriminate phase of cloud hydrometeors and thus study microphysical properties of mixed-phase clouds, that represent a major source of uncertainty in aerosol indirect effect for future climate projections.

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A high-speed particle phase discriminator (PPD-HS) for the classification of airborne particles, as tested in a continuous flow diffusion chamber

Atmospheric Measurement Techniques ◽

10.5194/amt-12-3183-2019 ◽

2019 ◽

Vol 12 (6) ◽

pp. 3183-3208 ◽

Cited By ~ 1

Author(s):

Fabian Mahrt ◽

Jörg Wieder ◽

Remo Dietlicher ◽

Helen R. Smith ◽

Chris Stopford ◽

...

Keyword(s):

Particle Shape ◽

Continuous Flow ◽

High Speed ◽

Scattered Light ◽

Diffusion Chamber ◽

Ice Crystals ◽

Supervised Machine Learning ◽

Particle Phase ◽

New Instrument ◽

Phase Discriminator

Abstract. A new instrument, the High-speed Particle Phase Discriminator (PPD-HS), developed at the University of Hertfordshire, for sizing individual cloud hydrometeors and determining their phase is described herein. PPD-HS performs an in situ analysis of the spatial intensity distribution of near-forward scattered light for individual hydrometeors yielding shape properties. Discrimination of spherical and aspherical particles is based on an analysis of the symmetry of the recorded scattering patterns. Scattering patterns are collected onto two linear detector arrays, reducing the complete 2-D scattering pattern to scattered light intensities captured onto two linear, one-dimensional strips of light sensitive pixels. Using this reduced scattering information, we calculate symmetry indicators that are used for particle shape and ultimately phase analysis. This reduction of information allows for detection rates of a few hundred particles per second. Here, we present a comprehensive analysis of instrument performance using both spherical and aspherical particles generated in a well-controlled laboratory setting using a vibrating orifice aerosol generator (VOAG) and covering a size range of approximately 3–32 µm. We use supervised machine learning to train a random forest model on the VOAG data sets that can be used to classify any particles detected by PPD-HS. Classification results show that the PPD-HS can successfully discriminate between spherical and aspherical particles, with misclassification below 5 % for diameters >3 µm. This phase discrimination method is subsequently applied to classify simulated cloud particles produced in a continuous flow diffusion chamber setup. We report observations of small, near-spherical ice crystals at early stages of the ice nucleation experiments, where shape analysis fails to correctly determine the particle phase. Nevertheless, in the case of simultaneous presence of cloud droplets and ice crystals, the introduced particle shape indicators allow for a clear distinction between these two classes, independent of optical particle size. From our laboratory experiments we conclude that PPD-HS constitutes a powerful new instrument to size and discriminate the phase of cloud hydrometeors. The working principle of PPD-HS forms a basis for future instruments to study microphysical properties of atmospheric mixed-phase clouds that represent a major source of uncertainty in aerosol-indirect effect for future climate projections.

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Investigating particle phase velocity in a 3D spouted bed by a novel fiber high speed photography method

10.1063/1.4816878 ◽

2013 ◽

Author(s):

Long Qian ◽

Yong Lu ◽

Wenqi Zhong ◽

Xi Chen ◽

Bing Ren ◽

...

Keyword(s):

Phase Velocity ◽

High Speed ◽

High Speed Photography ◽

Particle Phase ◽

Spouted Bed ◽

Photography Method

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High-speed electro-fusion and electro-transfection of plant protoplasts by a continuous flow electro-manipulator

Plant Cell Reports ◽

10.1007/bf00269311 ◽

1988 ◽

Vol 7 (3) ◽

pp. 153-157 ◽

Cited By ~ 17

Author(s):

T. Hibi ◽

H. Kano ◽

M. Sugiura ◽

T. Kazami ◽

S. Kimura

Keyword(s):

Continuous Flow ◽

High Speed ◽

Plant Protoplasts

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Chemical and Clinical Evaluation of the Continuous-flow Analyzer "SMAC"

Clinical Chemistry ◽

10.1093/clinchem/20.8.1062 ◽

1974 ◽

Vol 20 (8) ◽

pp. 1062-1070 ◽

Cited By ~ 10

Author(s):

Morton K Schwartz ◽

Victor G Bethune ◽

Martin Fleisher ◽

Gina Pennacchia ◽

Celia J Menendez-Botet ◽

...

Keyword(s):

Continuous Flow ◽

High Speed ◽

Total Bilirubin ◽

Carbon Dioxide Content ◽

Protein Matrix ◽

Sodium Potassium ◽

Calcium Phosphorus ◽

Matrix Reference Material ◽

Computer Controlled ◽

Speed Computer

Abstract "SMAC" (Sequential Multiple Analyzer plus Computer) is a high-speed computer-controlled multitest analyzer. A 20-channel prototype SMAC (glucose, urea nitrogen, creatinine, carbon dioxide content, total bilirubin, calcium, phosphorus, cholesterol, iron, uric acid, chloride, sodium, potassium, total protein, albumin, creatine kinase, alkaline phosphatase, lactate dehydrogenase, and aspartate and alanine aminotransferases) has been evaluated for: (a) method precision during within-day runs and on a day-to-day basis over a period of time; (b) method linearity over a range established on a chemical basis and related to clinical requirements, with use of both aqueous standards and protein matrix reference material; and (c) correlation of SMAC values with those obtained by the methods routinely in use in our department.

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US Navy High Speed Craft – Comparison of ABS and DNV Structural Requirements

10.5957/smc-2005-d26 ◽

2005 ◽

Author(s):

Raymond H. Kramer

Keyword(s):

High Speed ◽

Recent Experience ◽

Hull Girder ◽

Structural Modifications ◽

Allowable Stresses ◽

The Us ◽

Us Navy ◽

Rule Sets ◽

Littoral Combat Ship

Recent experience with the Littoral Combat Ship (LCS), Focused Mission Ship, Ship Structure Committee (SSC) Project SR 1437 and other programs for the US Navy has required the development of structural designs for the unique loads that occur on high speed craft. Using the ABS Rules for Building and Classing High Speed Naval Craft (ABS HSNC) and the DNV Rules for Classification of High Speed, Light Craft and Naval Surface Craft, (DNV HSLC&NSC) the hull girder, slamming and vehicle deck loads required for the design of a US Navy High Speed craft/combatant are reviewed herein. Materials and allowable stresses associated with each of the class society’s rules are summarized along with the required loads and resulting structural modifications for SSC Project SR 1437, which used each of the two rule sets to determine the structural modifications for converting a commercial, high speed ferry into a high speed military transport capable of unrestricted (i.e., open ocean) operation.

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Development and Evaluation of a High-Speed Continuous-Flow Analyzer

Clinical Chemistry ◽

10.1093/clinchem/18.9.1013 ◽

1972 ◽

Vol 18 (9) ◽

pp. 1013-1018

Author(s):

M A Evenson ◽

M A Olson

Keyword(s):

Continuous Flow ◽

High Speed ◽

High Performance ◽

Operating Characteristics ◽

Raw Data ◽

Automatic Computer ◽

Carry Over ◽

First Time

Abstract A high-speed, high-performance, continuous-flow analyzer is described that operates at two to three times the usual analysis rate without necessitating corrections of the raw data and with no decrease in accuracy or precision. At faster speeds (180-300 samples/h) inductive sample interaction (%Ii), opposite in direction to carry-over, is for the first time quantitatively measured. A correction equation for %Ii was developed, and when it is applied to raw data, the accuracy of the results are significantly improved. Operating characteristics of the high-speed analyzer are described and the desirability of automatic computer corrections is discussed for the high-speed system.

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Design and Performance of a Miniaturized High-Speed Continuous-Flow Analyzer

Clinical Chemistry ◽

10.1093/clinchem/20.4.424 ◽

1974 ◽

Vol 20 (4) ◽

pp. 424-427 ◽

Cited By ~ 6

Author(s):

William E Neeley ◽

Stephen C Wardlaw ◽

Helen C Sing

Keyword(s):

Sample Size ◽

Continuous Flow ◽

High Speed ◽

Clinical Laboratory ◽

Small Animal ◽

Sample Volume ◽

Small Sample ◽

Reagent Consumption ◽

And Performance ◽

Made In

Abstract Design features and performance of a miniaturized high-speed continuous-flow analyzer are described. Special emphasis is made in the design towards a system that is free from the operational and mechanical complexities found in most of today’s advanced systems. Depending on the particular analyses, sample size varies from 3 to 25 µl and reagent consumption is less than 180 µl per sample. Analyses are performed under steady-state conditions at sampling rates of 150 samples per hour with a 2:1 or 3:1 sample-to-wash ratio. The marked reduction in sample size makes the system ideal for microanalyses, especially in the pediatric clinical laboratory, in small animal research, and in any other cases where small sample volume is especially important.

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Dielectrophoretic classification of fibres: principles and application to glass fibres suspended in air

EPJ Web of Conferences ◽

10.1051/epjconf/201921302053 ◽

2019 ◽

Vol 213 ◽

pp. 02053

Author(s):

Frantisek Lizal ◽

Milan Maly ◽

Jakub Elcner ◽

Arpad Farkas ◽

Ondrej Pech ◽

...

Keyword(s):

Electric Field ◽

High Speed ◽

Deposition Velocity ◽

Uniform Electric Field ◽

Electrical Mobility ◽

Mobility Separation ◽

Neutral Particles ◽

Naturally Occurring ◽

Two Parameters

Particles exposed to an electric field experience forces that influence their movement. This effect can be used for filtration of air, or for size classification of aerosols. The motion of charged particles in a non-uniform electric field is called electrophoresis. Two processes are involved in this phenomenon: 1) charging of particles and 2) electrical mobility separation. If fibres are exposed to electrophoresis, they are separated on the basis of two parameters: diameter and length. Regrettably, as naturally occurring fibres are polydisperse both in diameter and length, the electrophoresis is not very efficient in length classification. In contrast, dielectrophoresis is the motion of electrically neutral particles in a non-uniform electric field due to the induced charge separation within the particles. As deposition velocity of fibres induced by dielectrophoretic force strongly depends on length and only weakly on diameter, it can be used for efficient length classification. Principles of length classification of conducting and non-conducting fibres are presented together with design of a fibre classifier. Lastly, images of motion of fibres recorded by high-speed camera are depicted.

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