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Koskinas MF, Moreira DS, Yamazaki IM, Colonno M, Semmler R, Morais TSL, Dias MS. Primary standardization and Monte Carlo modeling of ( 243Am + 239Np) by means of a 4π(PC)-γ coincidence counting system. Appl Radiat Isot 2023; 202:111070. [PMID: 37837831 DOI: 10.1016/j.apradiso.2023.111070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/14/2023] [Accepted: 10/09/2023] [Indexed: 10/16/2023]
Abstract
The procedure followed by the Nuclear Metrology Laboratory (LMN) at the IPEN for the primary standardization of a (243Am + 239Np) solution, in secular equilibrium, is described. The measurement was carried out in a 4π(PC) (α,β)-γ coincidence system. The total activity per unit mass of the solution was determined by the extrapolation technique, using a software coincidence counting systsem. The extrapolation curves were compared with Monte Carlo calculations by means of Code ESQUEMA, used in previous works, which, was improved and applied in order to calculate the alpha, beta, gamma, X-rays and coincidence spectra.
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Affiliation(s)
- Marina F Koskinas
- Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000, São Paulo, SP, Brazil
| | - Denise S Moreira
- Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000, São Paulo, SP, Brazil
| | - Ione M Yamazaki
- Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000, São Paulo, SP, Brazil
| | - Marcelo Colonno
- Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000, São Paulo, SP, Brazil
| | - Renato Semmler
- Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000, São Paulo, SP, Brazil
| | - Thales S L Morais
- Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000, São Paulo, SP, Brazil
| | - Mauro S Dias
- Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000, São Paulo, SP, Brazil.
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Nsabimana G, Hong L, Yuhai B, de Dieu Nambajimana J, Jinlin L, Ntacyabukura T, Xiubin H. Soil aggregate disintegration effects on soil erodibility in the water level fluctuation zone of the Three Gorges Reservoir, China. Environ Res 2023; 217:114928. [PMID: 36435488 DOI: 10.1016/j.envres.2022.114928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 11/03/2022] [Accepted: 11/22/2022] [Indexed: 06/16/2023]
Abstract
Spatial hydrological alterations can affect soil structural stability. Over time, forces induced by water weaken soil aggregates and this has a negative implication to soil health. The Three Gorges Reservoir (TGR) in particular, experienced a long-term hydrological condition and repetitive seasonal water level fluctuations that could affect soil health. The present study was conducted to investigate the effects of different water levels on soil aggregate disintegration rate over time and its relation to soil erosion susceptibility in water reservoirs. Samples from different elevations (155 m, 160 m, 163 m, 166 m, 172 m, and 180 m) in the water level fluctuation zone (WLFZ) were exposed to continuous wet-shaking for 3, 9, 27, 54, and 81 min resulted to different WLF intensity accordingly. The results showed a comparative difference between aggregates size before and after the experiment where micro-aggregates (<0.25 mm) increased with respect to elevations increase. The exponential prediction proved that aggregate stability decreased with the increase of WLF intensity, insisting the effects of continuous hydrological stress to aggregate break-down. A couple of factors definitely confirmed that soil erodibility (k) is primarily determined by disintegration of soil aggregates for the surface soil of the TGR. Despite the fact that Disintegration rate (Dr) and k showed a positive relationship, R2 = 0.73 (p < 0.05), the results showed that the soil properties decreasing Dr also decreases soil erodibility in the study area. Non-effective role of soil organic matter (SOM) for stabilizing soil aggregates was primarily related to water level fluctuations inhibiting decomposition. Relying on the present findings, environmental problems mostly soil erosion in the TGR could be therefore linked to excessive destabilization of soil aggregates. Therefore, the results of this study should play a major role in determining the factors primarily inducing soil erosion in river reservoirs.
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Affiliation(s)
- Gratien Nsabimana
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, PR China; University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Li Hong
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, PR China; University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Bao Yuhai
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, PR China.
| | - Jean de Dieu Nambajimana
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, PR China; University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Li Jinlin
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, PR China; University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Tite Ntacyabukura
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, PR China; University of Chinese Academy of Sciences, 100049, Beijing, China
| | - He Xiubin
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, PR China
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