Center for Nuclear Techniques

Ho Chi Minh City, Vietnam

Center for Nuclear Techniques

Ho Chi Minh City, Vietnam
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Chi C.L.,Ho Chi Minh City University of Technology | Hung S.N.,Ho Chi Minh City University of Technology | Ly N.L.,Center for Nuclear Techniques | Anh T.L.,Center for Nuclear Techniques
Proceedings - 3rd International Conference on Green Technology and Sustainable Development, GTSD 2016 | Year: 2016

X-ray diffraction has many applications in analyzing structure of crystal material, identifying chemical composition, determining phase percentage and analyzing stress. This paper presents a new method to determine the phase percentage of triple-phase hard alloy using the X-ray diffraction, based on the assumption that the measured phase diffraction energy is proportional to the phase volume in the material. Since then proposed to improve the process for determining the percentage of triple-phase materials by X-ray diffraction. This method can also be applied for multi-phase materials. © 2016 IEEE.

Tien T.M.,Ho Chi Minh City University of Technology | Phoi N.V.,Vinh University | Cuong L.C.,Ho Chi Minh City University of Technology | Tuyen L.A.,Center for Nuclear Techniques | Nguyen L.L.,Center for Nuclear Techniques
Proceedings - 3rd International Conference on Green Technology and Sustainable Development, GTSD 2016 | Year: 2016

Investigation of strain and residual stress in materials plays an important role in evaluation of the lifetime of machine components. Various methods have been also developed to determine the strains and residual stresses. X-ray diffraction is often used technique to measure the residual stress in the surface material, while layer removal method is common applied to determine the in-depth residual stress distribution. This paper will present the technique combining the X-ray diffraction with layer removal method to study of the strain and residual stress distribution in the thickness direction on JIS S45C quenched specimen. The result of the strain and residual stress distribution through the thickness direction are determined, in which the residual stress distribution is the inhomogeneous. © 2016 IEEE.

Dung T.Q.,Center for Nuclear Techniques | Lazar K.,Wakasa - Wan Energy Research Center
Radiation Physics and Chemistry | Year: 2017

Positron annihilation lifetime, Doppler broadening measurements have been used to study microporous FER and MFI structures containing framework subtituted iron in different amounts. Mesoporous SBA-15 samples without and with iron introduced to the pore walls were also investigated by these methods. Mössbauer measurements have been accompanied to prove the extent of isomorphous incorporation of iron into the different structures. The results reveal a certain dependence of lifetimes on the various pore and channel sizes. Addition of iron does not influence significantly the observed lifetimes in FER microporous systems. However a slight decrease of lifetimes can be observed in the MFI samples. The effect of addition of iron in mesoporous SBA-15 system is more expressed. Supplement of iron also has an influence on the S parameter of Doppler broadening spectra. © 2017 Elsevier Ltd

Duc D.V.,Institute of Physics | Giao N.M.,Center for Nuclear Techniques | Dung T.T.,Thu Dau Mot University
International Journal of Theoretical Physics | Year: 2014

The mass spectrum for spinor fields in extra dimensions is considered within the framework of the mass creation mechanism proposed in our previous works (Duc and Giao 2013; Duc and Giao J. Mod. Phys. 4(N7), 991, 2013; Duc et al. J. Phys Sci. Appl. (USA) 4(N1), 60, 2014; Duc and Giao J. Mod. Phys. 5(N6), 2014). It is shown that a single spinor field in the whole space-time with extradimensions corresponds to a set of multiplets of effective spinor fields in ordinary 4-dimensional space-time with masses obeying the sum rule expressed in terms of metric for extradimensions and parameter functions dictated from the periodicity conditions. © 2014 Springer Science+Business Media New York.

Duc D.V.,Institute of Physics | Giao N.M.,Center for Nuclear Techniques
International Journal of Theoretical Physics | Year: 2016

We propose a mechanism for explaining the originality of charge creation based on some specific assumptions related to space – time extra dimensions. It holds that the existence and the compactification of extra dimensions are the origin for creating the interaction charge in ordinary 4 – dimensional space – time. © 2015, Springer Science+Business Media New York.

Luan L.Q.,Center for Nuclear Techniques | Uyen N.H.P.,Center for Nuclear Techniques | Ha V.T.T.,Saigon Thuy Canh Corporation
Scientia Horticulturae | Year: 2012

The basic medium containing half-strength of MS basal medium, full-strength of vitamin MS, 20mll -1 coconut water and 2gl -1 activated charcoal supplemented with 170mgl -1 NaH 2PO 4, 10mgl -1 2,4D and 0.1mgl -1 TDZ was found to be appropriate for callus formation of Paphiopedilum delenatii and Paphiopedilum callosum. Additional supplementation with 2.0mgl -1 BA and 0.1mgl -1 TDZ in combination with NaH 2PO 4 and 50mgl -1 oligochitosan enhanced PLB multiplication. Shoot bud proliferation of tested orchids was optimally increased in a basic medium supplemented with 0.5mgl -1 TDZ and 0.1mgl -1 NAA. The basic medium supplemented with NaH 2PO 4 was suitable for plantlet regeneration. In addition, the values of LD 50 (lethal dosage of 50% irradiated samples) of protocorm like bodies, shoot buds and in vitro plantlets were determined for P. delenatii (20Gy, 23.7Gy and 38Gy, respectively) and P. callosum (23Gy, 27.1Gy and 40.4Gy, respectively). No variant line was found for both orchid samples irradiated by gamma-rays, whereas 24 variant lines (which are divided among the two tested Paphiopedilum) were screened for samples irradiated by C 6+ ion-beams (3Gy). The genetic relationships among six generated variant lines and wild types were analyzed using RAPD techniques. Irradiation-induced variation is promising for developing new mutant varieties of Paphiopedilum. © 2012 Elsevier B.V.

Dung T.Q.,Center for Nuclear Techniques
International Journal of Nuclear Energy Science and Technology | Year: 2010

A simple gamma technique based on using two identical detectors has been studied and applied to assay radwaste drums. The characterisation and performance of the measurement system are discussed for practical application. The results show that the proposed technique successfully solved the problem of assay of unusual radwaste drums (as released from Dalat Nuclear Reactor, Vietnam). © 2010 Inderscience Enterprises Ltd.

Niimura N.,Ibaraki University | Kikuchi K.,Ibaraki University | Tuyen N.D.,Ibaraki University | Tuyen N.D.,Center for Nuclear Techniques | And 2 more authors.
Journal of Environmental Radioactivity | Year: 2015

We conducted an elution experiment with contaminated soils using various aqueous reagent solutions and autoradiography measurements of contaminated bamboo shoots and shiitake mushrooms to determine the physical and chemical characteristics of radioactive Cs from the Fukushima Daiichi Nuclear Power Plant accident. Based on our study results and data in the literature, we conclude that the active Cs emitted by the accident fell to the ground as granular non-ionic materials. Therefore, they were not adsorbed or trapped by minerals in the soil, but instead physically adhere to the rough surfaces of the soil mineral particles. Granular Cs* can be transferred among media, such as soils and plants. The physical properties and dynamic behavior of the granular Cs* is expected to be helpful in considering methods for decontamination of soil, litter, and other media. © 2013 The Authors.

Luan L.Q.,Center for Nuclear Techniques | Uyen N.H.P.,Center for Nuclear Techniques
International Journal of Biological Macromolecules | Year: 2014

The (1→3)-β-d-glucan extracted from the yeast cell wall was irradiated by γ-rays from a Co-60 source at dose range of 100-300kGy in a swelling condition of 10, 15 and 20% for degradation. The water-soluble contents of irradiated samples obtained by 10% (1→3)-β-d-glucan mixture increased from 25.89 to 66.71% by the increasing of irradiation doses from 100 to 300kGy. While the molecular weight of the water-soluble (1→3)-β-d-glucan was found to be decreased from 48.13 to 10.77kDa. In the UV-spectra of irradiated water-soluble (1→3)-β-d-glucan, a new peak appeared at 265nm with the intensity increased by the increase of the dose. The IR spectra of irradiated (1→3)-β-d-glucan were recognized by a decrease of the peak intensity at 1156cm-1 indicated to COC glycosidic linkages with the increasing of irradiation dose. In addition, radiation degraded (1→3)-β-d-glucan with Mw about 18kDa prepared at the dose of 250kGy displayed a strongly promotion effect on the growth of mustard green and the optimum concentration of the degraded (1→3)-β-d-glucan was found to be about 75mgl-1. Thus, the degraded (1→3)-β-d-glucan prepared by radiation technique displayed as a promising, safety and high effective plant growth promoter for agriculture application. © 2014 Elsevier B.V.

Suc N.V.,Ho Chi Minh City University of Technology and Education | Bich T.T.,Center for Nuclear Techniques
Radiochimica Acta | Year: 2013

This paper presents a simple and accurate method for determination of uranium isotopes (234U and 238U) in seawater samples using alpha spectrometry. Uranium is pre-concentrated from seawater samples via adsorption on hydrotalcite at pH 6.5. The absorbent is dissolved into 50 ml of 8M HNO3; then filtered through a Dowex-1 column. U(VI) in the elution solution is reduced to U(IV) using zinc metal in 4M solution of HCl and then co-precipitated with LaF3. The chemical separation efficiency is found to be 97.12±2.68%, eliminating the need of using 232U tracer in other published methods. This method is validated via comparison with results obtained using inductively coupled plasma mass spectrometry (ICP-MS) and neutron activation analysis (NAA) for three seawater samples. © by Oldenbourg Wissenschaftsverlag, München.

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