Van Thang Nguyen, Nguyen Phong Thu Huynh, Cong Hao Le
Environmental Science and Pollution Research (2020)
Abstract:
Groundwater is a major source of drinking water and agricultural water in some regions of the world. However, it contains a high level of 226Ra that is potentially hazardous to human health and the environment. Normally, the activity concentration of 226Ra in groundwater is determined to assess the quality of groundwater that can be used as drinking water. There are few studies on the accumulation of 226Ra in the agricultural soil due to irrigation with groundwater. In this study, levels of 226Ra were determined on over 60 groundwater samples collected from the public water supply wells in Phu Yen province, Vietnam. Besides assessment of the health risks to population due to drinking groundwater samples, the impact of groundwater irrigation to the maize field in the study area was studied. For this purpose, two chemical fate models were applied and the comparison of their results was performed. Based on the model assessments, we predicted that the present agricultural practices increased the 226Ra activity concentration in the maize soil, and the level of 226Ra activity concentration in the topsoil can exceed the recommended level at 11.4 years of the present agricultural practices on the maize soil.
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Trần Nhân Giang, Nguyễn Tấn Được, Nguyễn Thị Mỹ Lệ, Bùi Hoàng Minh
Tạp chí Khoa học Trường Đại học Cần Thơ Tập 56, Số chuyên đề: Khoa học tự nhiên (2020)(1):90-97
Tóm tắt:
Nghiên cứu này được thực hiện nhằm khảo sát khả năng phục hồi ảnh của thuật toán tích chập trong phương pháp chụp ảnh nhiễu xạ sử dụng tia X kết hợp không hoàn toàn. Nghiên cứu được thực hiện bằng việc sử dụng chùm tia X tới với các mức độ kết hợp khác nhau và các loại mẫu khác nhau nhằm khảo sát khả năng phục hồi ảnh của thuật toán tích chập ở những điều kiện khác nhau. Kết quả đạt được trong nghiên cứu này cho phép đánh giákhả năng áp dụng của thuật toán tích chập trong phương pháp chụp ảnh nhiễu xạ sử dụng tia X kết hợp không hoàn toàn.
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Abstract:
A first γ-ray study of 47,49Cl spectroscopy was performed at the Radioactive Isotope Beam Factory with 50Ar projectiles at 217 MeV/nucleon, impinging on the liquid hydrogen target of the MINOS device. Prompt deexcitation γ rays were measured with the NaI(Tl) array DALI2+. Through the one-proton knockout reaction 50Ar(p,2p), a spin assignment could be determined for the low-lying states of 49Cl from the momentum distribution obtained with the SAMURAI spectrometer. A spin-parity Jπ=3/2+ is deduced for the ground state of 49Cl, similar to the recently studied N=32 isotope 51K. The evolution of the energy difference E(1/21+)−E(3/21+) is compared to state-of-the-art theoretical predictions.
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Investigation of the effects of chemotherapy on trace element contents in the nails in patients with colorectal cancer
Phuong Truc Huynh, Binh Thanh Dinh, Linh Thi Truc Nguyen, Loan Thi Hong Truong, Hanh Van Nguyen, Dung Manh Ho, Dong Van Nguyen, Anh Tuan Tran
Journal of Radioanalytical and Nuclear Chemistry (2021) 328:1173–1180
Abstract:
The aim of this study was to evaluate the effects of cancer treatment with chemotherapy for the trace elements in nails of patients with colorectal cancer. The contents of trace elements in the nails of 102 patients with colorectal cancer (including treated and untreated) and 60 healthy subjects were analyzed using k0-standardization method of neutron activation analysis. All participants aged between 32 and 76. Result of this study showed that the contents of nine trace elements (As, Br, Co, Cr, Hg, Fe, Sc, Se, and Zn) in the nails were measured. Furthermore, this study showed that there was significant difference in the contents of the elements Fe, Se, and Zn in both colon and rectal cancer patient groups between untreated and treated subjects with chemotherapy. We conclude that the contents of Fe, Se, and Zn in the nail samples may be used to evaluate of the colorectal cancer risk, and they may be affected by chemotherapy.
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Investigation of prompt 𝛾-ray neutron activation spectrometer at the Dalat research reactor using Geant4 simulation
Chau Thanh Tai, Tran Thien Thanh, Pham Ngoc Son, Chau Van Tao
Radiation Physics and Chemistry 208 (2023) 110884
Abstract:
The prompt 𝛾-ray activation analysis (PGAA) detector, which has been developed at the Dalat nuclear research reactor, is investigated in this study. The Geant4 model is proposed for the PGAA detector to evaluate the Compton scattering background suppression. Based on this model, the detector efficiency in the energy range from 0.1 MeV to 11 MeV was determined using the thermal neutron capture of chlorine, titanium, nitrogen, and reference sources. The detector efficiencies in the unsuppressed and suppressed modes and the difference of efficiencies in both modes were calculated. Additionally, the suppression of additional peaks of the PGAA detector was also estimated in this work. Finally, the polynomial function for the detector efficiency and the ratio of additional peaks to corresponding full-energy peaks were determined. This work makes an essential contribution to the analysis of prompt 𝛾-ray spectrum acquired from the PGAA detector at the Dalat nuclear research reactor.
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Influences of Soil and Plant Types on The Mitigation Rateof Radium‑226 in The Cultivated Soils
Van Thang Nguyen, Nguyen Phong Thu Huynh, Cong Hao Le
Water Air Soil Pollut (2024) 235:95
Abstract
The effects of fertilizers, irrigation water, and air dust pollution on the long-term accumulation of radionuclides in surface soils have been investigated worldwide. In addition, many factors cause the removal of radionuclides from the soil. The removal rate is difficult to estimate because it is controlled by several parameters such as agricultural practices and soil properties. In this study, the mitigation rate of Ra-226 in the topsoil of agricultural soils in 20 fields in Vietnam was measured. The rate was considered two main processes that rejected radionuclides from the topsoil. Moreover, the soil-to-plant transfer factors (TF) and solid/liquid partition coefficients (Kd) for these soils have been reported. It was found that the obtained values of TF and Kd were wide and depended on the plant and soil types. The new experimental method gives the leaching rate of Ra-226 matching that based on the models, except for the rice paddy soil. For twenty considered soils, the mitigation rates of Ra-226 were from 0.1 to 0.58 Bq kg−2 y−1. The trend of Ra-226 mitigation correlated with the uptake ability of the plant (TF) and the Ra-226 concentration in pore water (Kd).
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