1,720,970 research outputs found
A PRELIMINARY SURVEY OF THE ANALYSIS OF NATURAL AND ARTIFICIAL RADIONUCLIDES IN SAMPLES COLLECTED IN ROSS BAY, ANTARCTICA
No full text137Cs distribution was determined by high resolution gamma-ray spectroscopy in sediment and soil samples from Terra Nova Bay , Antarctic
DISTRIBUTION OF CS-137 IN LAKE-SEDIMENTS AND SURROUNDING SOILS AT TERRA-NOVA BAY ANTARCTICA
No full textRadioactivity data (Bq/kg) from sea bottom and lake sediment samples collected in the 1987-88, 1988-89 and 1989-90 Italian expeditions in Antarctica are presented. Vertical distribution of Cs-137 in lake sediment cores and soil pits collected in the 1989-90 Expedition are discussed, together with the resulting inventories of the radionuclide; comparisons with literature data concerning both specific activities and inventories are also reported
HEAVY-METALS, IN WASTE MATERIALS - LEACHING OF BOTTOM ASHES BY COAL POWER-PLANTS
No full textBottom ash of a coal electric power plant has been studied for heavy metal release and its behavior has been compare with that of fly ash coming from the same combustible material.It has been shown that, during leaching, the grater part of metals passes into solution together with the soluble part of the matrix in which they are contained, but metallic ions also come from the insoluble fraction of the ash
Preliminary investigations on7Be as a tracer in the study of environmental processes
No full textThe usefulness of cosmogenic7Be as a tracer in a terrestrial environment has been investigated. Atmospheric fluxes and inventories of the radionuclide in grassland have been determined. Environmental behavior in connection with foliar interception and possibility of subsequent release has been studied. © 1995 Akadémiai Kiadó
Marine sediments and snow from ross sea region (Antarctica) dating by 210 Pb method
No full text210Pb is widely used to determine accumulation rates in order to obtain a time scale in environmental samples. The most accurate method uses the determination of 210Pb via its grand-daughter 210Po by alpha spectrometry. Unfortunately this method requires a complex wet-chemistry procedure to achieve the separation of 210Po from its matrix. In this work a simplified procedure for the chemical separation of 210Po is proposed and applied to three marine sediment cores and a 10 m snow core collected in Antarctica. The calculated sedimentation rates for marine sediments range from 0.053 to 0.071 cm y-1. The mean annual accumulation rate for the snow is 16.6 cm y-1 w.e.. A comparison with literature data in the same region is given
THE RECYCLING OF CERAMIC SLUDGES IN THE PRODUCTION PROCESS - AN OPTION FOR CERAMIC TILE FACTORIES TO REACH ZERO POLLUTION
No full textThe paper considers a way of minimizing the pollution due to ceramic sludges, by rationalizing the addition of waste waters and sludges in tile production processes. The analytical and rheological results, obtained on the body slips used for white gres tile production in waste or purified waters, demonstrate that the addition of dried sludges up to 5% wt (in place of the < 2% wt amount till now used) makes the slip completely compatible with industrial requirements. This paper evidences the possibility of direct use of waste waters, containing sludges, in the wet grinding process, making purification treatments of waters unnecessary and greatly reducing the economical engagement
Distribution of 226Ra in the Ross Sea-Antarctica
No full textAn improved procedure for the determination of 222Rn and 226Ra in seawater developed for easier on-board operations is presented. Data on the radioactive disequilibrium between the mentioned radionuclides as directly determined in the field can be greatly helpful in the study of the gas-exchange processes at the air-sea interface, especially as far as the Antarctic Ocean is concerned. The method employed has been preliminarly tested in laboratory on a set of seawater samples collected in the Ross Sea and 226Ra data collected are discussed and compared to literature data
Assessment of summer trends of tropospheric radon isotopes in a coastal Antarctic station (Terra Nova Bay)
No full textThis work reports the first results of atmospheric radon measurements performed at the Italian Antarctic station located at Terra Nova Bay (74.69°S; 164.12°E) during summer campaigns of 1995-96, 1996-97 and 1997-98. Mean 222Rn concentrations was 0.51±0.43 Bq m-3(median = 0.37 Bq m-3), and ranged from 0.01 to 2.74 Bq m-3. On the average, these values were considered high, in comparison to results reported for other sites in Antarctica at equivalent latitudes. This could be explained by two causes: radon data for Terra Nova Bay were only for the summer period, when the ice-free area is at its maximum and thus the radon emission to the atmosphere; and by the larger ice-free area at Terra Nova Bay compared, for example, to measurements taken at another Antarctic site by the same technique (Ferraz station-62°05′S; 058°23.5′W). The mean 222Rn to 220Rn activitty ratio was 4.4±4.2, ranging between 0.1 and 45.3. The highest ratios indicated that some of observed surges of concentration of222Rn could be attributed to not local sources. Lower radon concentrations were observed during katabatic wind events. The diurnal radon variation followed the general trend observed for continental areas located at lower latitudes
- …
