scholarly journals A Study of Cirrus Ice Particle Size Distribution Using TC4 Observations

2010 ◽  
Vol 67 (1) ◽  
pp. 195-216 ◽  
Author(s):  
Lin Tian ◽  
Gerald M. Heymsfield ◽  
Lihua Li ◽  
Andrew J. Heymsfield ◽  
Aaron Bansemer ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Size Spectra ◽  
Lognormal Distributions ◽  
Characteristic Particle ◽  
In Situ Observations

Abstract An analysis of two days of in situ observations of ice particle size spectra, in convectively generated cirrus, obtained during NASA’s Tropical Composition, Cloud, and Climate Coupling (TC4) mission is presented. The observed spectra are examined for their fit to the exponential, gamma, and lognormal function distributions. Characteristic particle size and concentration density scales are determined using two (for the exponential) or three (for the gamma and lognormal functions) moments of the spectra. It is shown that transformed exponential, gamma, and lognormal distributions should collapse onto standard curves. An examination of the transformed spectra, and of deviations of the transformed spectra from the standard curves, shows that the lognormal function provides a better fit to the observed spectra.

Particle Size Distribution and Morphology of in Situ Suspension Polymerized Toner

2003 ◽  
Vol 42 (22) ◽  
pp. 5568-5575 ◽  
Author(s):  
Jun Yang ◽  
Ting-Jie Wang ◽  
Hong He ◽  
Fei Wei ◽  
Yong Jin
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution

scholarly journals X-Ray Tomography Study on Porosity and Particle Size Distribution in In Situ Al-4.5Cu-5TiB2 Semisolid Rolled Composites

JOM ◽  
2019 ◽  
Vol 71 (11) ◽  
pp. 4050-4058 ◽  
Author(s):  
Swapnil Morankar ◽  
Monalisa Mandal ◽  
Nadia Kourra ◽  
Mark A. Williams ◽  
Rahul Mitra ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
X Ray

scholarly journals Influence of Particle Charge and Size Distribution on Triboelectric Separation—New Evidence Revealed by In Situ Particle Size Measurements

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 381 ◽  
Author(s):  
Johann Landauer ◽  
Petra Foerst
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Starch Content ◽  
Dynamics Simulation ◽  
Height Distribution ◽  
Particle Charge ◽  
Separation Chamber ◽  
Triboelectric Charging

Triboelectric charging is a potentially suitable tool for separating fine dry powders, but the charging process is not yet completely understood. Although physical descriptions of triboelectric charging have been proposed, these proposals generally assume the standard conditions of particles and surfaces without considering dispersity. To better understand the influence of particle charge on particle size distribution, we determined the in situ particle size in a protein–starch mixture injected into a separation chamber. The particle size distribution of the mixture was determined near the electrodes at different distances from the separation chamber inlet. The particle size decreased along both electrodes, indicating a higher protein than starch content near the electrodes. Moreover, the height distribution of the powder deposition and protein content along the electrodes were determined in further experiments, and the minimum charge of a particle that ensures its separation in a given region of the separation chamber was determined in a computational fluid dynamics simulation. According to the results, the charge on the particles is distributed and apparently independent of particle size.

scholarly journals Normalized Hail Particle Size Distributions from the T-28 Storm-Penetrating Aircraft

2019 ◽  
Vol 58 (2) ◽  
pp. 231-245 ◽  
Author(s):  
Paul R. Field ◽  
Andrew J. Heymsfield ◽  
Andrew G. Detwiler ◽  
Jonathan M. Wilkinson
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Size Distribution ◽  
Optical Probe ◽  
Particle Size Distributions ◽  
South Dakota School ◽  
Significant Damage ◽  
In Situ Observations ◽  
Cloud Evolution

AbstractHail and graupel are linked to lightning production and are important components of cloud evolution. Hail can also cause significant damage when it precipitates to the surface. The accurate prediction of the amount and location of hail and graupel and the effects on the other hydrometeor species depends upon the size distribution assumed. Here, we use ~310 km of in situ observations from flights of the South Dakota School of Mines and Technology T-28 storm-penetrating aircraft to constrain the representation of the particle size distribution (PSD) of hail. The maximum ~1-km hail water content encountered was 9 g m−3. Optical probe PSD measurements are normalized using two-moment normalization relations to obtain an underlying exponential shape. By linking the two normalizing moments through a power law, a parameterization of the hail PSD is provided based on the hail water content only. Preliminary numerical weather simulations indicate that the new parameterization produces increased radar reflectivity relative to commonly used PSD representations.

Observations of the Particle Size Distribution and Concentration in a Coastal System using an In Situ Laser Analyzer

2002 ◽  
Vol 36 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Teresa Serra ◽  
Xavier Casamitjana ◽  
Jordi Colomer ◽  
Timothy C. Granata
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Water Column ◽  
Size Distribution ◽  
Posidonia Oceanica ◽  
High Energy ◽  
Suspended Particles ◽  
Energy Conditions ◽  
Coastal System

An in situ laser particle size analyzer (LISST-100, Sequoia Scientific, Inc.) has been used to study the particle size distribution and concentration of biological and non biological particles in the water column of a Mediterranean coastal system. Two field campaigns have been carried out during low and high energy conditions of the flow, caused by the passage of a storm front. For the low energy period, the water column remained stratified, whereas for the high energetic period the water column was warmer and well mixed. The first study dealt with the distribution of particles near the bottom of the coastal area. Here, two regions were taken into account. The first region was a sea-grass meadow of Posidonia oceanica and the second region was a barren sand area. The second study dealt with the determination of the vertical distribution of suspended particles in the whole water column of the system. The results showed a decrease in the vertical concentration of suspended particles in the water column with the passage of the storm front, which was associated with advection of warm water mass rather than by vertical mixing. In contrast, vertical resuspension determined the fate of suspended particles at the bottom of the water column and an increase of their concentration was found.

Particle size distribution of river-suspended sediments determined by in situ measured remote-sensing reflectance

2015 ◽  
Vol 54 (20) ◽  
pp. 6367 ◽  
Author(s):  
Yuanzhi Zhang ◽  
Zhaojun Huang ◽  
Chuqun Chen ◽  
Yijun He ◽  
Tingchen Jiang
Keyword(s):  
Remote Sensing ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Suspended Sediments ◽  
Remote Sensing Reflectance

scholarly journals X-ray tomography studies on porosity and particle size distribution in cast in-situ Al-Cu-TiB2 semi-solid forged composites

2016 ◽  
Vol 118 ◽  
pp. 57-64 ◽  
Author(s):  
James Mathew ◽  
Animesh Mandal ◽  
Jason Warnett ◽  
Mark A. Williams ◽  
Madhusudan Chakraborty ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
X Ray ◽  
Semi Solid

scholarly journals The Spectral Aerosol Extinction Monitoring System (SǼMS): setup, observational products, and comparisons

2014 ◽  
Vol 7 (3) ◽  
pp. 701-712 ◽  
Author(s):  
A. Skupin ◽  
A. Ansmann ◽  
R. Engelmann ◽  
H. Baars ◽  
T. Müller
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Monitoring System ◽  
Aerosol Extinction ◽  
Extinction Coefficients ◽  
Spectrally Resolved ◽  
Automated Instrument ◽  
Statistical Results

Abstract. The Spectral Aerosol Extinction Monitoring System (SǼMS) is presented that allows us to continuously measure the spectral extinction coefficient of atmospheric aerosol particles along an approximately 2.7 km long optical path at 30–50 m height above ground in Leipzig (51.3° N, 12.4° E), Germany. The fully automated instrument measures the ambient aerosol extinction coefficients from 300 to 1000 nm. The main goal of SǼMS observations are long-term studies of the relationship between particle extinction and relative humidity from below 40% to almost 100%. The setup is presented and observations (a case study and statistical results for 2009) are discussed in terms of time series of 550 nm particle optical depth, Ångström exponent, and particle size distribution retrieved from the spectrally resolved extinction. The SǼMS measurements are compared with simultaneously performed EARLINET (European Aerosol Research Lidar Network) lidar, AERONET (Aerosol Robotic Network) sun photometer, and in situ aerosol observations of particle size distribution and related extinction coefficients on the roof of our institute. Consistency between the different measurements is found, which corroborates the quality of the SǼMS observations. Statistical results of a period of 1 yr (2009) show mode extinction values of 0.09 km−1 (SǼMS), 0.075 km−1 (AERONET), and 0.03 km−1 (in situ). Ångström exponents for this period are 0.19 (390–880 nm, SǼMS) and 1.55 (440–870 nm, AERONET).

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