scholarly journals Chemical composition of dust storms in Beijing and implications for the mixing of mineral aerosol with pollution aerosol on the pathway

2005 ◽  
Vol 110 (D24) ◽  
Author(s):  
Yele Sun ◽  
Guoshun Zhuang ◽  
Ying Wang ◽  
Xiujuan Zhao ◽  
Jie Li ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Dust Storms

The chemical composition of aerosols settling in Israel following dust storms

1991 ◽  
Vol 25 (12) ◽  
pp. 2665-2670 ◽  
Author(s):  
E. Ganor ◽  
H.A. Foner ◽  
S. Brenner ◽  
E. Neeman ◽  
N. Lavi
Keyword(s):  
Chemical Composition ◽  
Dust Storms

A comparative evaluation of water uptake on several mineral dust sources

2010 ◽  
Vol 7 (2) ◽  
pp. 162 ◽  
Author(s):  
Juan G. Navea ◽  
Haihan Chen ◽  
Min Huang ◽  
Gregory R. Carmichel ◽  
Vicki H. Grassian
Keyword(s):  
Chemical Composition ◽  
Relative Humidity ◽  
Dust Particle ◽  
Water Uptake ◽  
Mineral Dust ◽  
Dust Storms ◽  
Dust Aerosol ◽  
Dust Particles ◽  
Particle Interactions ◽  
Dust Sources

Environmental context. Dust particles produced from wind blown soils are of global significance as these dust particles not only impact visibility, as evident in the recent 2009 Australian dust storm, but also atmospheric chemistry, climate and biogeochemical cycles. The amount of water vapour in the atmosphere (relative humidity) can play a role in these global processes yet there are few studies and little quantitative data on water-dust particle interactions. The focus of this research is on quantifying water-dust particle interactions for several dust sources including Asia and Africa where dust storms are most prevalent. Abstract. Mineral dust aerosol provides a reactive surface in the troposphere. The reactivity of mineral dust depends on the source region as chemical composition and mineralogy of the aerosol affects its interaction with atmospheric gases. Furthermore, the impact of mineral dust aerosol in atmospheric processes and climate is a function of relative humidity. In this study, we have investigated water uptake of complex dust samples. In particular, water uptake as a function of relative humidity has been measured on three different dust sources that have been characterised using a variety of bulk and surface techniques. For these well-characterised dust samples, it is shown that although there are variations in chemical composition and mineralogy, on a per mass basis, water uptake capacities for the three dusts are very similar and are comparable to single component clay samples. These results suggest that the measured uptake of water of these bulk samples is dominated by the clay component.

Chemical composition of PM2.5 in an urban environment in Chengdu, China: Importance of springtime dust storms and biomass burning

2013 ◽  
Vol 122 ◽  
pp. 270-283 ◽  
Author(s):  
Jun Tao ◽  
Leiming Zhang ◽  
Guenter Engling ◽  
Renjian Zhang ◽  
Yihong Yang ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Urban Environment ◽  
Biomass Burning ◽  
Dust Storms

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

On the Inhomogeneity of Chemical Composition over the Surface of 21 Per

1976 ◽  
Vol 32 ◽  
pp. 343-349
Author(s):  
Yu.V. Glagolevsky ◽  
K.I. Kozlova ◽  
V.S. Lebedev ◽  
N.S. Polosukhina
Keyword(s):  
Chemical Composition ◽  
Spectral Line ◽  
Variable Star ◽  
Radial Velocities ◽  
Crimean Astrophysical Observatory ◽  
Line Intensities ◽  
Magnetic Variable

SummaryThe magnetic variable star 21 Per has been studied from 4 and 8 Å/mm spectra obtained with the 2.6 - meter reflector of the Crimean Astrophysical Observatory. Spectral line intensities (Wλ) and radial velocities (Vr) have been measured.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

Applications of Photoelectron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 506-507
Author(s):  
William J. Baxter
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Chemical Composition ◽  
Ultraviolet Radiation ◽  
Thin Layer ◽  
Edge Effects ◽  
Electron Optics ◽  
Surface Layers ◽  
Crystalline Orientation ◽  
Fluorescent Screen

In this form of electron microscopy, photoelectrons emitted from a metal by ultraviolet radiation are accelerated and imaged onto a fluorescent screen by conventional electron optics. image contrast is determined by spatial variations in the intensity of the photoemission. The dominant source of contrast is due to changes in the photoelectric work function, between surfaces of different crystalline orientation, or different chemical composition. Topographical variations produce a relatively weak contrast due to shadowing and edge effects.Since the photoelectrons originate from the surface layers (e.g. ∼5-10 nm for metals), photoelectron microscopy is surface sensitive. Thus to see the microstructure of a metal the thin layer (∼3 nm) of surface oxide must be removed, either by ion bombardment or by thermal decomposition in the vacuum of the microscope.

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