Determining the appropriate ratio of fly ash as cement replacement in concrete and evaluating the radiation dose of the fly ash concrete
Lam Duy Nhat, Vu Tuan Minh, Ho Van Doanh, Le Huu Loi, Le Quang Vuong, Phan Long Ho, Tran Thien Thanh, Hoang Duc Tam
Journal of Radioanalytical and Nuclear Chemistry
Abstract:
This study uses fly ash (FA) as a cement replacement in concrete and evaluates the radiological safety of this concrete sample. Different fly ash mixing ratios were investigated and found that with a mixing ratio of 35%, the compressive strength of FA concrete is the highest (from 38 to 48 MPa). Next, we evaluate the radiation safety of the FA concrete by analyzing the isotopes 226Ra, 232Th, and 40K using two low background gamma spectrometers. The obtained results showed that the use of FA in concrete production is entirely feasible as it meets both construction and radiation safety-related requirements.
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Huynh Truc Phuong, Tran Pham Ngoc Trinh, Dinh Thanh Binh, Nguyen Thi Truc Linh, Truong Thi Hong Loan, Tran Tuan Anh, Ho Manh Dung, Nguyen Van Dong
Science & Technology Development Journal, 22(4):370-377
Abstract:
Introduction: Breast cancer is the most common type of cancer resulting in death. Trace elements of Fe, Se and Zn can play a key role in the onset and prevention of breast cancer. Trace elements in the fingernails may be used as bioindicators for breast cancer diagnosis. The purpose of this work is to determine the concentrations of Fe, Se, and Zn in the fingernails of women with breast cancer and healthy women, which used to find the difference and correlation of these elements in the fingernail.
Methods: This research was approved by the Ethics Committee of Dong Nai General Hospital. The fingernail collected from 29 women with breast cancer and 30 healthy women, who are the same age and living in Dong Nai province, Vietnam. The concentrations of Fe, Se, and Zn in the fingernails were determined using the k0-INAA method. The analytical data were evaluated using some statistical analysis for the correlation of trace elements in the fingernails of both groups.
Results: As a result, the mean concentrations of Fe, Se and Zn in fingernails of women with breast cancer were 102.87 ug/g, 0.75 ug/g and 65.49 ug/g, respectively, while those of healthy women were 69.74 ug/g, 0.78 ug/g and 107.75 ug/g. The assessment of these elements in fingernails for both two sample groups, including t-test and correlation coefficients, was also carried out in this study. As a result, the significant difference (p < 0.05) was found for the Fe and Zn in fingernails of women with breast cancer, while those of Se was not found. The correlation between Se and Zn was found in both groups. The correlation between Fe and Zn was found in fingernails of healthy women, but it disappears in the women with breast cancer.
Conclusions: From our finding, it can be concluded that Fe and Zn significantly associated with the risk of breast cancer, while Se is not associated.
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Determination of some elements in the nails in patients with colon cancer using total reflection X-ray fluorescence
Huynh Truc Phuong, Nguyen An Son, Nguyen Thi Nguyet Ha, Nguyen Thi Minh Sang, Nguyen Thi Truc Linh, Dinh Thanh Binh, Truong Thi Hong Loan, Ho Manh Dung, Tran Tuan Anh, Nguyen Van Dong
Spectrochimica Acta Part B: Atomic Spectroscopy 182 (2021) 106234
Abstract:
Sixty-two subjects (31 men with colon cancer) participated in this study. The analysis of elements in the nails was performed by total reflection X-ray fluorescence (TXRF) technique. The results showed that fifteen elements were quantifed, including the following: S, P, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, and Br. We have found that there were significant differences in the concentrations of elements Ca, Cr, Fe, Cu, Zn, As, and Se between normal subjects and men with colon cancer (p < 0.05). We conclude that TXRF is a technique suitable for elemental analysis in human nail samples. The concentration of elements Ca, Cr, Fe, Cu, Zn, As, and Se could be among the factors used for the diagnosis of colon cancer risk in men.
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DEPTH-DOSE DISTRIBUTION DEPENDENCE ON THE ENERGY PROFILE OF LINEAR AND LASER WAKEFIELD ACCELERATOR ELECTRON BEAMS
N.A.Tuan, C.V.Tao, R.Chary
12th Int. Particle Acc. Conf.
Abstract:
The depth-dose distributions of 10 MeV electron beams used for food irradiation and sterilization purposes at Research and Development Center for Radiation Technology, HCMC, Vietnam are measured and the results are well re-produced by the MCNP simulations. We extend the simulations to predict the dose depth distribution for 10 MeV electron beams with the energy profiles of a model Laser Wake Field accelerator (LWFA). The dosimetry and simulation results show that the maximum dose of the depth-dose curve inside the product are 1.4 times surface dose with an area density limit of 8.6 g/cm2 for two-sided irradiation with nearly mono-energetic beams from linear accelerator and the corresponding parameters for LWFA are 1.2 times surface dose and 13.0 g/cm2, respectively.
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Constraining the α-nucleus potential for α-decay calculation with nuclear rainbow scattering
Nguyen Tri Toan Phuc, Le Hoang Chien, Chau Van Tao
Science & Technology Development Journal, 25(1):1-9
Abstract:
Introduction: The emission of a particles is a powerful probe for the α-cluster structure of heavy nuclei. The α-nucleus potential is a crucial ingredient in the a-decay calculation within the preformed cluster model. One of the most reliable ways to construct this potential is the double folding model, where an effective nucleon-nucleon interaction is folded with the nuclear densities. In the folding model calculation, there are many ambiguities in the choice of the nuclear densities of the daughter nucleus for α-decay. We propose to directly constrain the α-nucleus potential for α- decay and choose the daughter nuclear density using the nuclear rainbow scattering phenomenon.
Methods: The refractive rainbow pattern in the elastic scattering cross section within the optical model can probe deep into the interior region of the α-nucleus potential. We apply this method to investigate the reliability of the nuclear potential used in the α-decay of the 212Po nucleus leading to the 208Pb daughter nucleus by examining the elastic a scattering on 208Pb. In such an approach, we perform the double-folding calculation to construct the α-nucleus potential using several common parametrizations of the daughter nuclear densities. These parametrizations include the mean-field Hartree-Fock-Bogoliubov calculations with the BSk14 and D1S interactions, the independent particle model, and the 2-parameter Fermi distributions. The obtained nuclear potentials are applied to the optical model to calculate the elastic α-208Pb scattering cross sections that are compared with the experimental data. These nuclear potentials are further used in the preformed cluster model to study thea-decay half-life of 212Po.
Results: The nuclear densities from the Hartree-Fock-Bogoliubov calculations are shown to provide the best description for both the nuclear rainbow scattering anda-decay half-life. The results indicate a strong correspondence between the capabilities of the nuclear potential to reproduce the cross section ofa scattering and the α-decay half-life. The extracteda preformation factors from the semiclassical preformed cluster model with folding potentials are in good agreement with those from other studies.
Conclusion: The nuclear rainbow scattering phenomenon can be used to provide reliable a-nucleus potential
for α-decay studies within the preformed cluster model. The nuclear densities from the mean-field Hartree-Fock-Bogoliubov method with the BSk14 and D1S interactions are the appropriate choices for the DFM calculation used in the α-decay study.
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Consistent mean-field description of the 12C+12C optical potential at low energies and the astrophysical S factor
Abstract:
The nuclear mean-field potential built up by the 12C+12C interaction at energies relevant for the carbon burning process is calculated in the double-folding model (DFM) using the realistic ground-state density of 12C and the CDM3Y3 density dependent nucleon-nucleon (NN) interaction, with the rearrangement term properly included. To validate the use of a density dependent NN interaction in the DFM calculation in the low-energy regime, an adiabatic approximation is suggested for the nucleus-nucleus overlap density. The reliability of the nuclear mean-field potential predicted by this low-energy version of the DFM is tested in a detailed optical model analysis of the elastic 12C+12C scattering data at energies below 10 MeV/nucleon. The folded mean-field potential is then used to study the astrophysical S factor of 12C+12C fusion in the barrier penetration model. Without any adjustment of the potential strength, our results reproduce very well the nonresonant behavior of the S factor of 12C+12C fusion over a wide range of energies.
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