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TRƯỜNG ĐẠI HỌC KHOA HỌC TỰ NHIÊN, ĐẠI HỌC QUỐC GIA THÀNH PHỐ HỒ CHÍ MINH

KHOA VẬT LÝ - VẬT LÝ KỸ THUẬT

BỘ MÔN VẬT LÝ HẠT NHÂN - NGÀNH KỸ THUẬT HẠT NHÂN - NGÀNH VẬT LÝ Y KHOA

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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Consistent mean-field description of the 12C+12C optical potential at low energies and the astrophysical S factor

Le Hoang Chien, Dao T. Khoa, Do Cong Cuong, and Nguyen Hoang Phuc

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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Consistency test of coincidence-summing calculation methods for extended sources

O.Sima, A.De Vismes Ott, M.S.Dias, P.Dryak, L.Ferreux, D.Gurau,  S.Hurtado, P.Jodlowski, K.Karfopoulos, M.F.Koskinas, M.Laubenstein, Y.K.Lee, M.C.Lépy, A.Luca, M.O.Menezes, D.S.Moreira, J.Nikolič, V.Peyres, P.Saganowski, M.I.Savva, R.Semmler, J.Solc, T.T.Thanh, K.Tyminska, Z.Tyminski, T.Vidmar, I.Vukanac, H.Yucel

Abstract:

An internal consistency test of the calculation of coincidence-summing correction factors FC for volume sources is presented. The test is based on exact equations relating the values of FC calculated for three ideal measurement configurations. The test is applied to a number of 33 sets of FC values sent by 21 teams. Most sets passed the test, but not the results obtained using the quasi-point source approximation; in the latter case the test qualitatively indicated the magnitude of the bias of FC.

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The COMET Collaboration

Abstract:

The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminum nucleus (μe conversion, μN eN); a lepton flavor- violating process. The experimental sensitivity goal for this process in the Phase-I experiment is 3.1 × 1015, or 90% upper limit of a branching ratio of 7 × 1015, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the μe conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described.

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Trần Thiện Thanh, Văn Tấn Phát, Lê Hoàng Minh, Huỳnh Đình Chương, Võ Hoàng Nguyên, Nguyễn Trí Toàn Phúc, Lê Quang Vương, Nguyễn Duy Thông, Châu Văn Tạo
 
Sci. Tech. Dev. J. - Nat. Sci.; 4(2):Online-First
 
TÓM TẮT: 
Các thông số đặc trưng của vật liệu liên quan đến tương tác của bức xạ photon như: hệ số suy giảm khối, số nguyên tử hiệu dụng, mật độ electron là những dữ liệu cần thiết được yêu cầu trong nhiều công việc như chẩn đoán và xạ trị ung thư, chiếu xạ công nghiệp, tính liều lượng bức xạ, che chắn phóng xạ, phân tích hàm lượng nguyên tố và đồng vị phóng xạ. Trong bài báo này, các mô hình lý thuyết như tham số dạng phi tương đối tính (NRFF), tham số dạng tương đối tính (RFF), tham số dạng hiệu chỉnh (MFF) được sử dụng để tính toán tỉ số Rayleigh-Compton đối với các nguyên tố có 6<=Z<=82 tại năng lượng 59,5 keV. Kết quả chỉ ra rằng có sự khác biệt lớn giữa các mô hình tính toán đối với bia có số nguyên tử lớn. Giá trị trung bình của tỉ số Rayleigh-Compton theo số nguyên tử Z được làm khớp hàm bậc hai mô tả khá tốt quy luật phụ thuộc này với hệ số tương quan R2 =0,996. Bên cạnh đó, hệ đo thực nghiệm cũng được thiết kế và thực nghiệm đo đạc đối với một số bia như nhôm, đồng và chì tại góc tán xạ 150o sử dụng nguồn 241Am bằng đầu dò Si(Li) để kiểm chứng với kết quả tính toán lý thuyết. Kết quả thực nghiệm ban đầu đã chỉ ra rằng có sự phù hợp tốt giữa các mô hình lý thuyết với các bia nhôm, đồng và chì với độ sai biệt dưới 20%. Trong tương lai, chúng tôi sẽ tiến hành thực nghiệm với nhiều dạng bia khác nhau để đánh giá chi tiết hơn.
Từ khoá: NRFF, RFF, MFF, Tỉ số Rayleigh-Compton, đầu dò Si(Li)
 
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Nguyen Anh TUAN and Chau Van TAO

Nuclear Technology & Radiation Protection: Year 2020, Vol. 35, No. 1, pp. 36-41

Abstract:

An electron beam from the UELR-10-15S2 accelerator (average energy of 9.92 ± 0.48 MeV) was applied to irradiate food and medical items at the Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute, Vietnam. The materials are under an electron beam window, such as irradiation products, conveyor, magnet and shielding mate- rial for the magnet coil, bombarded by electrons and generated X-ray (bremsstrahlung effect). In this article, X-ray conversion efficiency from polypropylene, aluminum, iron, and lead bombarded by an electron beam from the UELR-10-15S2 accelerator is measured by the film dosimeter and simulated by the MCNP4c2 code, and there is good agreement between the calculation and measurement results. The results show that X-ray conversion efficiency is the highest from lead (4.3 %), so the gamma - neutron reaction (Q-value of –6.74 MeV for 207Pb) has to be studied in food and medical items irradiated by a 10 MeV eelectron beam.

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