Determination of the levels of Na, K, Ca, Mg, Fe, Zn and Cu in aerosols of the western Venezuelan savannah region

1996 ◽  
Vol 180 (2) ◽  
pp. 155-164 ◽  
Author(s):  
J MORALES ◽  
D PIRELA ◽  
J DURAN
Keyword(s):  
Zn And Cu In ◽  
Venezuelan Savannah

The use of flux-corer experiments in the determination of heavy metal re-distribution in and of potential leaching from the sediments

1998 ◽  
Vol 37 (6-7) ◽  
pp. 283-290 ◽  
Author(s):  
R. Van Ryssen ◽  
M. Alam ◽  
L. Goeyens ◽  
W. Baeyens
Keyword(s):  
Heavy Metal ◽  
Water Policy ◽  
Sediment Cores ◽  
Metal Mobility ◽  
Overlying Water ◽  
Heavy Metal Mobility ◽  
Zn And Cu In ◽  
Concentration Changes ◽  
The Impact

Metal dynamics between sediments, interstitial water and overlying water are particularly complex. The movement of metals, their availability, and possible toxicity are influenced by various chemical and physical reactions and factors such as oxygen/redox gradients, pH, grain size, etc. To study the impact of oxygen on the release from and the re-distribution of Cd, Pb, Zn and Cu in sediments, flux-corer experiments have been optimised and performed. The flux experiment was carried out using 3 identical sediment cores. The first (control) sediment core was completely characterised before, the two other cores after the experiment. Pore water extractions and sequential extractions were performed on 2 cm depth intervals throughout the 20 cm long sediment cores. In the flux experiment, the sediment cores were exposed to a small volume of overlying water, which was continuously renewed. The change of trace metal mobility was assessed by following concentration-changes in the outflow. It has been found by the use of the flux-corer experiment, that the Cd, Pb, Zn and Cu concentrations in the outflow are at least 3-6 times higher during oxic conditions. Flux-corer experiments can be useful tools to facilitate the study of the change of heavy metal mobility and distribution in the sediment induced by the change in surface water policy.

scholarly journals Multiwavelength Spectral Correction for the Simultaneous Determination of Cu(II), Fe(II), and Zn(II) with 1-(5-Bromo-2-Pyridylazo)-2-Naphthol-6-Sulfonic Acid

2001 ◽  
Vol 84 (1) ◽  
pp. 532-536 ◽  
Author(s):  
Hong-Wen Gao
Keyword(s):  
Simultaneous Determination ◽  
Analytical Method ◽  
Sulfonic Acid ◽  
Free Ligand ◽  
Spectral Correction ◽  
Relative Standard ◽  
Zn And Cu In ◽  
Matrix Formula ◽  
Standard Deviations

Abstract A new analytical method is described for the simultaneous determination of various components by multiwavelength spectrophotometry. Because of the influence of the free ligand and various complexes on spectrophotometric absorption, the spectral correction principle was used to establish the calculation matrix formula. The 3 sensitive reactions of Cu(II), Fe(II), and Zn(II), with 1-(5-bromo-2-pyridylazo)-2-naphthol-6-sulfonic acid were studied at pH 10.5. In analyses of fortified samples, the recoveries of Fe, Zn, and Cu were between 93.0 and 103%, 87.0 and 108%, and 92.5 and 108%, respectively; the relative standard deviations for 5 determinations of Fe, Zn, and Cu in unfortified ore were 3.6, 5.8, and 4.5%, respectively.

Heavy Metal Pollution in the Surface Dust from E-Waste Disposal Place and its Ecological Risk Assessment

2011 ◽  
Vol 347-353 ◽  
pp. 2360-2364 ◽  
Author(s):  
Jia Ying Wang ◽  
Hao Chen ◽  
Wen Yu Xia ◽  
Ling Chen ◽  
Jian Fu Zhao ◽  
...  
Keyword(s):  
Waste Disposal ◽  
Ecological Risk ◽  
Metal Pollution ◽  
Electronic Waste ◽  
Potential Ecological Risk ◽  
Metal Concentrations ◽  
Household Appliance ◽  
Zn And Cu In ◽  
Home Appliance

Six specific types of surface dusts were collected from different e-waste disposal areas in Shanghai, China for the determination of toxic metals including Zn, Pb, Ni, Cd, Cr and Cu. These samples were obtained from interior of home appliance, second-hand household appliance maintaining store, open manual dissembling yard, enclosed electronic waste warehouse, enclosed dissembling workshop, as well as outside yard of plant. ICP-AES analyzing results revealed that metal concentrations in dust from home appliance interior and second-hand household appliance maintaining store were obviously higher than the soil background values. And the metal concentrations of dusts from open manual dissembling yard were similar to enclosed electronic waste warehouse. The concentrations of Pb, Zn and Cu in dust from enclosed dissembling workshop were about 3646.10, 3485.23 and 4049.70 mg/kg, which were respectively 9, 19 and 45 times higher than outside yard of plant. The potential ecological risks of metal pollution in these dusts were analyzed by estimating the distribution characterization of samples and the heavy metals. The results showed that potential ecological risk of Cu was the highest, and then was the Cd, Cr was the least. The ecological risk indexes of metals in dusts from enclosed dissembling workshop, home appliance interior and second-hand household appliance maintained store were considered to be significantly healthy harm, while those from open manual dissembling yard and enclosed electronic waste warehouse were relatively less harm.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

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