On the mean particle size and water content of polar mesospheric clouds

1985 ◽  
Vol 33 (10) ◽  
pp. 1209-1224 ◽  
Author(s):  
Gary E. Thomas ◽  
Christopher P. McKay
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Mean Particle Size ◽  
Polar Mesospheric Clouds ◽  
The Mean ◽  
Mesospheric Clouds

scholarly journals Albedo-Ice Regression method for determining ice water content of polar mesospheric clouds using ultraviolet observations from space

2019 ◽  
Vol 12 (3) ◽  
pp. 1755-1766 ◽  
Author(s):  
Gary E. Thomas ◽  
Jerry Lumpe ◽  
Charles Bardeen ◽  
Cora E. Randall
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Average Error ◽  
Polar Mesospheric Clouds ◽  
Mode Of Operation ◽  
Ice Water Content ◽  
Mesospheric Clouds ◽  
Using Data ◽  
Ultraviolet Observations ◽  
Ice Water

Abstract. High spatial resolution images of polar mesospheric clouds (PMCs) from a camera array on board the Aeronomy of Ice in the Mesosphere (AIM) satellite have been obtained since 2007. The Cloud Imaging and Particle Size Experiment (CIPS) detects scattered ultraviolet (UV) radiance at a variety of scattering angles, allowing the scattering phase function to be measured for every image pixel. With well-established scattering theory, the mean particle size and ice water content (IWC) are derived. In the nominal mode of operation, approximately seven scattering angles are measured per cloud pixel. However, because of a change in the orbital geometry in 2016, a new mode of operation was implemented such that one scattering angle, or at most two, per pixel are now available. Thus particle size and IWC can no longer be derived from the standard CIPS algorithm. The Albedo-Ice Regression (AIR) method was devised to overcome this obstacle. Using data from both a microphysical model and from CIPS in its normal mode, we show that the AIR method provides sufficiently accurate average IWC so that PMC IWC can be retrieved from CIPS data into the future, even when albedo is not measured at multiple scattering angles. We also show from the model that 265 nm UV scattering is sensitive only to ice particle sizes greater than about 20–25 nm in (effective) radius and that the operational CIPS algorithm has an average error in retrieving IWC of -13±17 %.

scholarly journals Albedo-Ice regression method for determining ice water content of Polar Mesospheric Clouds using ultraviolet observations from space

2018 ◽  
Author(s):  
Gary E. Thomas ◽  
Jerry Lumpe ◽  
Charles Bardeen ◽  
Cora E. Randall
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Average Error ◽  
Polar Mesospheric Clouds ◽  
Mode Of Operation ◽  
Ice Water Content ◽  
Mesospheric Clouds ◽  
Using Data ◽  
Ultraviolet Observations ◽  
Ice Water

Abstract. High spatial-resolution images of Polar Mesospheric Clouds (PMC) from a camera array onboard the Aeronomy of Ice in the Mesosphere Satellite have been obtained since 2007. The Cloud Imaging and Particle Size Experiment (CIPS) detects scattered ultraviolet (UV) radiance at a variety of scattering angles, allowing the scattering phase function to be measured for every image pixel. With well-established scattering theory, the mean particle size and ice water content (IWC) are derived. In the nominal mode of operation, approximately seven scattering angles are measured per cloud pixel. However, because of a change in the orbital geometry in 2016, a new mode of operation was implemented such that one, or at most two, scattering angles per pixel are now available. Thus particle size and IWC can no longer be derived from the standard CIPS algorithm. The Albedo-Ice Regression (AIR) method was devised to overcome this obstacle. Using data from both a microphysical model and from CIPS in its normal mode, we show that the AIR method provides sufficiently accurate average IWC so that PMC IWC can be retrieved from CIPS data into the future, even when albedo is not measured at multiple scattering angles. We also show from the model that 265 nm UV scattering is sensitive only to ice particle sizes greater than about 20–25 nm in (effective) radius, and that the operational CIPS algorithm has an average error in retrieving IWC of −13 ± 17 %.

Effect of Ag addition in Sn on growth of SnTe compound during reaction between molten solder and tellurium

2010 ◽  
Vol 25 (2) ◽  
pp. 391-395 ◽  
Author(s):  
Chien-Neng Liao ◽  
Yen-Chun Huang
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Electrical Properties ◽  
Bismuth Telluride ◽  
Molten Solder ◽  
Thermoelectric Modules ◽  
Ag Addition ◽  
Mean Particle Size ◽  
Mechanical And Electrical Properties ◽  
The Mean

SnTe is the most common compound formed at the bismuth telluride/metal soldered junction of thermoelectric modules. It affects the mechanical and electrical properties of the soldered junction. In the study we investigate the growth of SnTe compound during reaction between molten Sn–3.5Ag solder and tellurium at 250 °C. We found that the growth of SnTe is suppressed by Ag–Te bilayer compounds that block further reaction between liquid Sn and Te. With increasing reaction time, the SnTe morphology becomes rough as a result of coarsening of SnTe grains. The growth of SnTe grains follows the conservative ripening kinetics with the mean particle size proportional to one-third power of reaction time.

Microstructure and Thermodynamic Analysis of Graphene-Reinforced Coating Surface

2021 ◽  
Vol 1033 ◽  
pp. 56-60
Author(s):  
He Ping Liu ◽  
Heng Zhe Yang ◽  
Lang Lang Liu ◽  
Feng Er Sun ◽  
Xiao Min Yang ◽  
...  
Keyword(s):  
Particle Size ◽  
Thermodynamic Analysis ◽  
Induction Coil ◽  
Mean Particle Size ◽  
Substrate Distance ◽  
Cladding Layer ◽  
Coating Surface ◽  
The Mean ◽  
Graphene Content

The microstructure of coatings with different graphene content and the hardness of cladding layer under different distance between coil and samples were investigated. The results showed that with the increase of graphene, the mean particle size of the powder did not get significantly coarser. The defects and oxides were appeared in the cladding layer and graphene diffused into the substrate. Distance between induction coil and sample has great impact on the hardness of coating, the higher hardness was measured in the distance between 6-8cm. The thermodynamic analysis of coating nucleation was carried out.

Preparation of Nanocrystalline Fe2O3 Powder by Cryomilling with Liquid Nitrogen and its Magnetic Property

2020 ◽  
Vol 993 ◽  
pp. 806-810
Author(s):  
Zhi Wei Zhang ◽  
Bing Wei Luo ◽  
Hai Tao Zhou ◽  
Fen Wang
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Magnetic Property ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Single Phase ◽  
Rapid Preparation ◽  
Mean Particle Size ◽  
Milling Temperature ◽  
The Mean

Rapid preparation of nanocrystalline γ-Fe2O3 powder with superparamagnetism was realized by cryomilling commercial Fe2O3 powder using liquid nitrogen. The effects of milling temperature and duration on the grain size, phase and microstructure of the nanocrystalline Fe2O3 powder were analyzed. Magnetic property of the nanocrystalline γ-Fe2O3 powder was also tested by magnetometer at room temperature. The results demonstrate that nanocrystalline γ-Fe2O3 powder with single phase can be prepared rapidly by cryomilling with liquid nitrogen. The mean particle size of γ-Fe2O3 powder can be reduced from 300 nm to 13 nm by cryomilling at −130 °C within 3 hours. The nanocrystalline γ-Fe2O3 powder shows superparamagnetism at room temperature.

Preparation and Research of Oil in Water Microemulsion

2020 ◽  
Vol 1001 ◽  
pp. 110-114
Author(s):  
Xiao Qi Chen ◽  
Meng Meng Zhou ◽  
Zheng Zheng Wang ◽  
Hai Jun Zhou ◽  
Shu Lan Yang ◽  
...  
Keyword(s):  
Particle Size ◽  
Constant Temperature ◽  
Polydispersity Index ◽  
Stable System ◽  
Mass Ratio ◽  
Drop Method ◽  
Mean Particle Size ◽  
Oil In Water ◽  
The Mean ◽  
The Stability

A series of oil in water (O/W) microemulsions were prepared through drop by drop method at constant temperature, taking Span80/Tween80 as a composite emulsifying system and Macol-52 as oil phase. Effects of the mass ratio of composite emulsifying system and oil/emulsifier ratio on the particle size were studied. Finally, the best technological conditions were selected and the stability of the microemulsion was also researched. Results showed that the most suitable Span80/Tween80 mass ratio was 1:1 and the oil/emulsifier ratio is 1:1. Under this condition, the mean particle size of the o/w microemulsion was 71.1 nm and the polydispersity index was 0.151. Moreover, the microemulsion maintain a bright and uniform stable system after 20minutes’ centrifugation at the speed of 4000r/min and the particle size increased slightly.

The State of Polydispersion of Hevea Latex. II.

1947 ◽  
Vol 20 (2) ◽  
pp. 409-415
Author(s):  
J. H. E. Hessels
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
Degree Of Polymerization ◽  
The State ◽  
Rubber Industry ◽  
Mean Particle Size ◽  
Degree Of Dispersion ◽  
The Mean ◽  
In The Beginning

Abstract The influence of the degree of dispersion in latex on the composition and properties of the rubber was studied in detail by means of a series of latices, the mean particle size of which ranged from 1.1 to 0.15µ in diameter. These fractions were first obtained by centrifugation of preserved latex, and the degree of distribution was measured by photomicrographic analysis and by sedimentation. This method of fractionation yields latices and rubbers with compositions which differ widely. With decrease in the size of the particles, their surface area per unit of rubber increases, and the percentage of nonrubber components which is adsorbed irreversibly or which is dissolved in the serum increases greatly. On the contrary, the degree of polymerization decreases with decrease in the diameter of the particles. This may be explained by the fact that, in the beginning, the polymerization of the globules is relatively low, and that it progresses under the influence of a catalyst present in the serum. In brief, then, systematic dispersoidal analysis of Hevea latex is of prime importance in the plantation rubber industry.

Sign in / Sign up

Export Citation Format

Share Document