scholarly journals Measurement of aerosol sulfuric acid: 2. Pronounced layering in the free troposphere during the second Aerosol Characterization Experiment (ACE 2)

2001 ◽  
Vol 106 (D23) ◽  
pp. 31975-31990 ◽  
Author(s):  
J. Curtius ◽  
B. Sierau ◽  
F. Arnold ◽  
M. de Reus ◽  
J. Ström ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Free Troposphere ◽  
Aerosol Characterization

scholarly journals Charged and neutral binary nucleation of sulfuric acid in free troposphere conditions

2013 ◽  
Author(s):  
Jonathan Duplissy ◽  
Joonas Merikanto ◽  
Karine Sellegri ◽  
Clemence Rose ◽  
Eija Asmi ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Free Troposphere ◽  
Binary Nucleation

scholarly journals Rapid sulfuric acid–dimethylamine nucleation enhanced by nitric acid in polluted regions

2021 ◽  
Vol 118 (35) ◽  
pp. e2108384118
Author(s):  
Ling Liu ◽  
Fangqun Yu ◽  
Lin Du ◽  
Zhi Yang ◽  
Joseph S. Francisco ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Atmospheric Boundary Layer ◽  
High Temperatures ◽  
Cluster Formation ◽  
Particle Formation ◽  
Nucleation Mechanism ◽  
Free Troposphere ◽  
Particulate Pollution

Recent research [Wang et al., Nature 581, 184–189 (2020)] indicates nitric acid (NA) can participate in sulfuric acid (SA)–ammonia (NH3) nucleation in the clean and cold upper free troposphere, whereas NA exhibits no obvious effects at the boundary layer with relatively high temperatures. Herein, considering that an SA–dimethylamine (DMA) nucleation mechanism was detected in megacities [Yao et al., Science 361, 278–281 (2018)], the roles of NA in SA-DMA nucleation are investigated. Different from SA-NH3 nucleation, we found that NA can enhance SA-DMA–based particle formation rates in the polluted atmospheric boundary layer, such as Beijing in winter, with the enhancement up to 80-fold. Moreover, we found that NA can promote the number concentrations of nucleation clusters (up to 27-fold) and contribute 76% of cluster formation pathways at 280 K. The enhancements on particle formation by NA are critical for particulate pollution in the polluted boundary layer with relatively high NA and DMA concentrations.

Preparation of Thin Cadmium Telluride Samples for Electron Microscope Studies

1974 ◽  
Vol 32 ◽  
pp. 548-549
Author(s):  
T. J. Magee ◽  
J. Peng ◽  
J. Bean
Keyword(s):  
Electron Microscope ◽  
Sulfuric Acid ◽  
Solid State ◽  
Sample Preparation ◽  
Cadmium Telluride ◽  
Potassium Dichromate ◽  
Optical Components ◽  
The Past ◽  
Solid State Devices

Cadmium telluride has become increasingly important in a number of technological applications, particularly in the area of laser-optical components and solid state devices, Microstructural characterizations of the material have in the past been somewhat limited because of the lack of suitable sample preparation and thinning techniques. Utilizing a modified jet thinning apparatus and a potassium dichromate-sulfuric acid thinning solution, a procedure has now been developed for obtaining thin contamination-free samples for TEM examination.

Physical, Chemical, and Crystallographic Characterization of Anodic Coatings on High Strength Aluminum Base Alloys

1976 ◽  
Vol 34 ◽  
pp. 636-637
Author(s):  
R. E. Herfert ◽  
N. T. McDevitt
Keyword(s):  
Sulfuric Acid ◽  
Salt Spray ◽  
High Strength ◽  
Environmental Stability ◽  
Anodic Films ◽  
Sodium Dichromate ◽  
Corrosion Resistant ◽  
Aerospace Applications ◽  
Bond Strengths ◽  
Adhesive Bonded Joints

Durability of adhesive bonded joints in moisture and salt spray environments is essential to USAF aircraft. Structural bonding technology for aerospace applications has depended for many years on the preparation of aluminum surfaces by a sulfuric acid/sodium dichromate (FPL etch) treatment. Recently, specific thin film anodizing techniques, phosphoric acid, and chromic acid anodizing have been developed which not only provide good initial bond strengths but vastly improved environmental durability. These thin anodic films are in contrast to the commonly used thick anodic films such as the sulfuric acid or "hard" sulfuric acid anodic films which are highly corrosion resistant in themselves, but which do not provide good initial bond strengths, particularly in low temperature peel.The objective of this study was to determine the characteristics of anodic films on aluminum alloys that make them corrosion resistant. The chemical composition, physical morphology and structure, and mechanical properties of the thin oxide films were to be defined and correlated with the environmental stability of these surfaces in humidity and salt spray. It is anticipated that anodic film characteristics and corrosion resistance will vary with the anodizing processing conditions.

82. 24-HR Ambient and Residential Aerosol Characterization Using Automated Piezoelectric Cascade Impactors

2002 ◽  
Author(s):  
C. Marcham ◽  
D. Johnson ◽  
N. Esmen ◽  
R. Clinkenbeard ◽  
R. Lynch
Keyword(s):  
Cascade Impactors ◽  
Aerosol Characterization
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