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J. A numerical model of flow in sedimentation tanks in Slovakia , Pollack Periodica , Vol. 3 , No. 2 , 2008 , pp. 59 – 73 . [4] Deiningera

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–75. Kris J., Ghawi A. H. Design and optimization of sedimentation tank in Slovakia with CFD modeling, Proceedings of the 10th International Symposium on Water Management and Hydraulic Engineering 2007 (with special emphasis on the impact of hydraulic

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Abstract  

Sedimentation rates in Guanabara Bay were determined by applying the210Pb CRS method to sediment cores collected at five different stations. The results showed a pronounced increase from 0.1–0.2 cm·year−1 to 1–2 cm·year−1, in sedimentation rate, over the last 40–50 years. Observed heavy metal profiles in sediment could also be explained on the basis210Pb dating and local industrial history.

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Abstract  

In order to assess the effect of marine and terrestrial environmental change in the last decades on the sedimentation environment in Ariake Bay, we collected three sediment cores. The concentrations of natural and anthropogenic radionuclides, major elements, and rare-earth elements were measured using gamma-spectrometry and neutron activation analysis. Vertical distributions of both radionuclides and sedimentation rates, determined using Cs-137 and Pb-210ex dating methods, varied significantly among the sites.

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Abstract  

A total of eight sediment cores with 50 cm length were taken in the Sabah and Sarawak coastal waters using a gravity corer in 2004 to estimate sedimentation rates using four mathematical models of CIC, Shukla-CIC, CRS and ADE. The average of sedimentation rate ranged from 0.24 to 0.48 cm year−1, which is calculated based on the vertical profile of 210Pbex in sediment core. The finding also showed that the sedimentation rates derived from four models were generally shown in good agreement with similar or comparable value at some stations. However, based on statistical analysis of paired sample t-test indicated that CIC model was the most accurate, reliable and suitable technique to determine the sedimentation rate in the coastal area.

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Summary  

Sediment core samples were collected in the largest urban Lake Donghu (Stations I and II) in China, and the activities of 210Pb, 226Ra and 137Cs were measured by gamma-ray spectrometry. The sedimentation rates, calculated by 210Pb constant rate of supply (CRS) model, ranged from 0.11 to 0.65 (average 0.39) cm. y-1at Station I, and from 0.21 to 0.78 (average 0.46) cm. y-1at Station II. Sedimentation rate calculated by 137Cs as a time marker was 0.55 cm. y-1at Station II. Based on the average sedimentation rate, we obtained 769 and 147 t. y-1for nitrogen and phosphorus retentions in Lake Donghu sediments, respectively.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: R. Aliev, V. Bobrov, St. Kalmykov, M. Melgunov, I. Vlasova, V. Shevchenko, A. Novigatsky, and A. Lisitzin

Abstract  

Natural 210Pb and artificial 137Cs were applied for estimation of sedimentation rates for 14 cores collected in the White Sea, Franz Victoria and Novaya Zemlya troughs. Vertical profiles of 137Cs with high resolution (0.5–1 cm) are presented for 18 cores. The agreement between sedimentation rates obtained from 210Pb age-dating and 137Cs vertical profiles was found. Two maxima of 137Cs specific activity were observed in the cores near the North Dvina and Onega mouths, which may be correspond to the Chernobyl accident and global fallouts in early 1960-s.

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Summary  

In order to clarify the sedimentation rate of 210Pbexcess and 137Cs in brackish Lake Obuchi, bordered by nuclear fuel facilities in Rokkasho Village, Aomori, Japan, sediment core samples were collected at three points in the lake, and the rates were calculated by the chronological measurement method using 210Pb and 137Cs. The sedimentation rates were 0.29±0.04 g . cm-2 . y-1 in the estuary of the Futamata River (water depth of 1.2 m), 0.13±0.02 g . cm-2 . y-1 in the 3 m water depth area, and 0.11±0.02 g . cm-2 . y-1 at the center point (water depth of 4.5 m), respectively. The Futamata River estuary was found to be greatly affected by land erosion.

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Abstract  

For six sediment cores collected from Yamuna river (tributary of Ganges) around Delhi, rate of sedimentation was determined by the226Ra–210Pb method. While an average rate of 42 mm/y is obtained, there are variations core to core. A clear-cut downstream increase in the rate, from 5 mm/y when the river enters Delhi, to 80 mm/y when it leaves Delhi, indicates solid waste contribution from the urban areas. The sediment flux of 4000 mg/cm2/y is not balanced by the calculated rate of erosion (40 tonnes/km2/y) in the river. Thus, much of the sediment flux is of local origin.

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Abstract  

The Rio Grande reservoir lies southeast of the Metropolitan Area of São Paulo. In order to evaluate if the sediments contain a historical registration of anthropogenic activity, four sediment cores were sampled from the reservoir. In these cores the Hg concentration was determined by the CV AAS technique, major and trace elements by instrumental neutron activation analysis and the sedimentation rates by the 210Pb method. The results obtained for Hg are much higher than expected, showing an anthropogenic contribution. As a general trend, the elemental concentration decreases with depth, indicating recent contamination.

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