Soil, Climate, and Atmospheric Deposition Relationships with Elemental Concentrations in Annual Rings of Tuliptree

1993 ◽  
Vol 22 (1) ◽  
pp. 23-32 ◽  
Author(s):  
J. R. McClenahen ◽  
J. P. Vimmerstedt
2021 ◽  
Vol 50 (6) ◽  
pp. 1531-1541
Author(s):  
N.A. Son ◽  
L.H. Khiem ◽  
N.T.M. Sang ◽  
D.P.T. Tien ◽  
H.H. Thang

In this paper, two multielement analysis techniques, Neutron Activation Analysis (NAA) and Total Reflection X-ray Fluorescence (TXRF), are combined to detect elemental concentrations in Barbula indica moss collected at Dalat, Vietnam. Combining these two techniques has improved the qualitative detection of elements due to atmospheric deposition on moss samples. The concentrations of 40 elements, including Na, Mg, Al, Si, P, S, Cl, K, Ar, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Kr, Rb, Y, Sb, I, Cs, Ba, La, Ce, Sm, Eu, Tb, Dy, Yb, Hf, Ta, Pb, Th, and U in the Barbula indicamoss samples collected at 19 locations at Dalat have been determined. It is shown that the air in Dalat is suspected of contamination by Na, Mg, Si, P, S, V, Mn, Cu, Se, Br, and U; slightly contaminated by Mg, Cl, K, Cr, Ni, S, and Ni; moderately contaminated by Sc, Fe, Co, Zn, As, Kr, Rb, Y, Sb, Cs, Ba, La, Ce, Sm, Eu, Dy, Yb, Ta, Pb, and Th; and seriously contaminated by Tb. Factor analysis has been used to explain the contamination sources of these elements, including V, As, Fe, Zn, Se, Rb, Sb, Cs, Al, Cu, and Pb in the investigated area. Four factors have been extracted that can explain 86% of the total variance, and the results suggest that the main sources of atmospheric pollution in Dalat originate from traffic and windblown dust.


2000 ◽  
Vol 179 ◽  
pp. 193-196
Author(s):  
V. I. Makarov ◽  
A. G. Tlatov

AbstractA possible scenario of polar magnetic field reversal of the Sun during the Maunder Minimum (1645–1715) is discussed using data of magnetic field reversals of the Sun for 1880–1991 and the14Ccontent variations in the bi-annual rings of the pine-trees in 1600–1730 yrs.


Author(s):  
John C. Russ ◽  
Nicholas C. Barbi

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.


2003 ◽  
Vol 107 ◽  
pp. 1427-1427 ◽  
Author(s):  
J. Frank ◽  
M. Krachler ◽  
W. Shotyk

Reproduction ◽  
2000 ◽  
pp. 331-336 ◽  
Author(s):  
L Holm ◽  
H Ekwall ◽  
GJ Wishart ◽  
Y Ridderstrale

Sperm storage tubules from the utero-vaginal junction of chickens, quails and turkeys were analysed for calcium and zinc using X-ray microanalysis of ultra-rapidly frozen tissue in a scanning electron microscope. This technique enabled the tubular fluid surrounding the stored spermatozoa and the intracellular content of the cells of the sperm storage tubules to be analysed separately and, by using standards with known concentrations, their elemental concentrations were estimated. The mean (+/- SEM) concentration of calcium in the tubular fluid from chickens, quails and turkeys was 17 +/- 3, 19 +/- 3 and 17 +/- 4 mmol kg(-1) wet weight, respectively. The intracellular calcium concentration of the cells of the tubules did not differ significantly from these values and was also similar in the mucosal epithelial cells of the utero-vaginal junction. Zinc was localized in the cells of turkey sperm storage tubules and tubular fluid, but at low concentrations. No zinc could be detected in corresponding structures from chickens and quails. The concentration of calcium in the tubular fluid is within the range known to inhibit the motility of spermatozoa, supporting this function for calcium during storage. Zinc is known to depress turkey sperm metabolism and it may also be involved in inducing quiescence of spermatozoa during storage in this species.


2019 ◽  
Author(s):  
Chem Int

Public concern over the deleterious effects of atmospheric deposition (AD) has grown rapidly due to its adverse effects (teratogenicity, toxicity, and carcinogenicity) to human, animals, and materials. The aim of this review is to describe the effect of the AD on sculptures, measures for its reduction, and case studies on maintenances of sculptures against the AD. To this end, a step-by-step review is outlined to discuss the harmful effect of AD contamination on many important sculptures. The review paper is also extended to describe preventive steps to reduce AD on sculptures to help reduce the risks associated with AD.


Sign in / Sign up

Export Citation Format

Share Document