Browsing by Author Nguyen, Van Hung

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Showing results 6 to 25 of 26
  • 102.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Nguyen, Cong Toan; Hoang, Thi Khanh Giang (2010)

  • Analytical expressions for the ratio of the root mean square fluctuation in atomic positions on the equilibrium lattice positions and the nearest neighbor distance and the mean melting cgryes of bcc binary alloys haye been derived. This melting curve provides information on Lindemann's melting temperatures of binary alloys with respect to any proportion of constituent elements and on their euctectic points. Numerical results for some bcc binary alloys are found to be in agreement with experiment.

  • 115.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Nguyen, Cong Toan; Nguyen, Bao Trung; Ngo, Hoang Giang (2008)

  • Analytical expressions for the Morse potential parameters of diamond crystals have been derived. They contain the energy of sublimation, the compressibility and the lattice constant. Numerical calculations have been carried out for Si and Sn, and the result reflect fundamental calcultion of the anharmonic correlated effective potential parameters have been used for calculation of the anharmonic correlated effective potentials of these crystals in XAFS theory showing clearly anharmonic effects.

  • 237.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Dao, Xuan Viet (2003)

  • A new procedure for calculation of the Morse potential parameters of hexagonal closed packed (hcp) crystals has been developed using the energy of sublimation, the compressibility and the lattice constant. The derived equation of state and the elastic constants computed using the obtained Morse parameters agree with the experimental ones. This shows that the Morse dunction can be applied validly to the problems involving any type of deformation and atomic interaction in the hcp crystals.

  • 49.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Trinh, Thi Hue; Nguyen, Ba Duc (2015)

  • In this work, Morse potential parameters of bcc crystals have been calculated based on the calculation of volume per atom and atomic number in each elementary cell, as well as the energy of sublimation, the compressibility and the lattice constant. They are used for studying the anharmonic interatomic effective potential, local force constant in XAFS (X-ray Absorption Fine Structure) theory. Numerical results for Fe, W and Mo are found to be in good agreement with experiment and with those of other theories.

  • 3.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Trinh, Thi Hue; Nguyen, Ba Duc (2015)

  • In this work, Morse potential parameters of bcc crystals have been calculated based on the calculation of volume per atom and atomic number in each elementary cell, as well as the energy of sublimation, the compressibility and the lattice constant. They are used for studying the anharmonic interatomic effective potential, local force constant in XAFS (X-ray Absorption Fine Structure) theory. Numerical results for Fe, W and Mo are found to be in good agreement with experiment and with those of other theories.

  • 201.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Nguyen, Thi Thu Hoai; Le, Hai Hung (2004)

  • A new procedure for calculation and evaluation of XAFS cumulants of fee crystals containing impurity atom has been developed based on the quantum statistical theory with correlated Einstein model. Analytical expressions for the effective local force constants, correlated Einstein frequency and temperature, first cumulant or net thermal expansion, second cumulant or Debye Waller factor and third cumulant of fee crystals containing impurity atom have been derived. Morse potential parameters of pure crystals and those with impurity included in the derived expressions have been calculated. Numerical results for Cu. Ni. Ni-Cu are found to be in good agreement with experiment

  • 62.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Duong, Anh Tuan; Trinh, Duc Thien; Nguyen, Dang Phu; Danh, Bich Do; Pham, Van Vinh (2012)

  • CdTe quantum dots dispersed in water were prepared successfully by the microwave irradiation method. The influence of the pH value of the solution precursor, irradiation time and microwave power on the structure, size and optical properties of CdTe quantum dots was investigated. The fluorescence of CdTe quantum dots studies were illustrated that the samples which were synthesized at pH value of 7 exhibited the best fluorescence. The absorption, fluorescence spectra and TEM images showed that the microwave power and the irradiation time influenced significantly on the size of CdTe quantum dot as well as their optical properties. The fluorescence spectra were red-shift with the increase...

  • document(38).pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Bui, Thi Viet Ha; Dinh, Thuy Hang (2016)

  • An efficient method was established for isolation of bifidobacteria from fecal samples of breast-fed infants. The method was based on the combination of Hungate technique applied on anoxic semi-liquid agar tubes, instead of double layer agar plates. Four growth media including BFM, BIM25, MRS and 385 were compared for the isolation efficiency on the basis of Hungate technique. Thus, among 30 isolates obtained from fecal samples of 14 breast fed infants of different ages under 1 year only eight bifidobacteria-like isolates were selected based on cell morphology and fermentation motif. It is revealed that Hungate technique with the use of anaerobic MRS and BFM media was more efficient f...

  • 96.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Bui, Van Loat (2009)

  • The paper resented the results of assessing internal dose for 131I by the direct method for Vietnamese objects that was issued in the Intercomparison Program of IAEA. The results on experimental measurements, caculating intake (I) or 131I to thyroid by the specializing system for measuring thyroid activity, and committed effective dose E(50) using the specializing code of LUDEP 2.0 were shown that the results carrying out at the Nuclear Research Institute were goof and were in accordance with the those of the authors in other laboratories in the world.

  • 117.pdf.jpg
  • Article


  • Authors: Bui, Van Loat; Nguyen, Van Hung; Hoang, Sy Minh Phuong (2010)

  • At present, thickness measurement of materials based on effect of backscattering gamma-ray has been widely used in industry in our country. The report presented research in measuring thickness of some materials such as paper, plastic, aluminum and steel with using the dedicated system of MYO-101, having scintillation detector of YAP(Ce) and gamma-ray of 60 keV of Am-241 source, by Monte-Carlo simulation using the code of MCNP. The simulation was checked by experimental measurements. The results were shown that they were in accordance with the range of error. This research has been useful for training activities with a view of human resowces development in the field of application of n...

  • 122.pdf.jpg
  • Article


  • Authors: Khong, Cat Cuong; Trinh, Duc Thien; Pham, Thu Nga; Nguyen, Van Minh; Nguyen, Van Hung (2009)

  • In this article, we report on the preparation of CdSe quantum dots (QDs) by sol-gel method and their optical properties. The average size of QDs is also estimated by using various ways, such as the Scherer’s formula. The Effros-Brus-Kayanum a's theoretical expression, TEM etc. The TEM images of samples show that the mean sizes of QDs are 4 nm. The mean sizes of QDs are smaller than that of other methods and arranging from 2 to 3.6 nm.

  • 132.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Tran, Trung Dung; Nguyen, Cong Toan (2006)

  • A new procedure for description and calculation of th EXAFS (Extended X-ray Absorption Fine Structure) cumulants for fee crystals containing an abitrary number n of dopant atoms have been developed. Analytical expressions for the l 8t, 2nd and 3rd cumulants have been derived.They depend on the number of dopant atoms and approach those derived by anharmonic correlated Einstein model, if all dopant atoms are taken out or replacing all the host atoms. Numerical results for Cu doped by Ni atoms based on the Morse potential show significant dependence of thermodynamic parameters of the substance on the number of dopant atoms and a reasonable agreement with experiment.

  • 209.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Tran, Trung Dung; Nguyen, Cong Toan (2004)

  • A new procedure for description and calculation of the interaction potential and force constants for fee crystals containing an arbitrary number n of impurity atoms have been developed. Analytical expressions for the effective atomic interaction potential, the single-bond and effective spring constants have been derived. They depend on the number of the impurity atoms and approach those derived by using anharmonic correlated Einstein model, if all the impurity atoms are taken out or they replace all the host atoms. Numerical results for Ni doped by Cu atoms show significant changes of the interact on potential and spring constants of the substance if the number of impurity ato...

  • 125.pdf.jpg
  • Article


  • Authors: Bui, Van Loat; Nguyen, Van Quan; Le, Tuan Anh; Tran, The Anh; Nguyen, The Nghia; Nguyen, Van Hung (2009)

  • Radioactive sources which used to study were the standardized radioactive of common monoenergetic radionuclide Cs137 and standardized multigamma Co60, Ba133, Eu152. Determination of the absolute efficiency curve and energy resolution as a function of energy of GEM40P4 HPGe spectrometer are presented in this paper.

  • 59.pdf.jpg
  • Article


  • Authors: Le, Huynh My Van; Nguyen, Van Hung (2014)

  • In this paper, we study the systems of generalized quasiequilibrium problems which includes as special cases the generalized vector quasi-equilibrium problems, vector quasiequilibrium problems, and establish the existence results for its solutions by using fixed-point theorem. Moreover, we also discuss the closedness of the solution sets of systems of generalized quasiequilibrium problems. As special cases, we also derive the existence results for vector quasiequilibrium problems and vector quasivariational inequality problems. Our results are new and improve recent existing ones in the literature.

  • TELEVISION AUDIENCE MEASUREMENT & APPLYING ON ADVERTISING ACTIVITY IN VIETNAM.pdf.jpg
  • Thesis


  • Authors: Nguyen, Van Hung;  Advisor: Nguyen, Thi Hong Hanh (2018)

  • Television Audience Measurement is a popular field of study in the world but quite new for the Vietnam. The objective of the research is introduce a new and effective approach to the study of television audience to help advertiser/media agency/broadcaster understand the audience characteristics, habits, tastes… from which they can build and develop the effective and optimal communications strategies.

  • 184.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Ho, Khac Hieu; Nguyen, Cong Toan (2006)

  • A new procedure for calculation and analysis of thermodynamic and correlation effects of bcc crystals under in fluence of dopant atom in the X-ray Absorption Fine Structure (XAFS) has been developed. Analytical expression for the Displacement-displacement Correlation Function (DCF) CR has been derived based on the derived Mean Square Relative Displacement (MSRD) 2 Ơ2 and Mean Square Displacement (MSD) u of bcc crystals containing dopant atom. Numerical calculations have been carried out for Fe doped by w and by Cr atom. They are found to be in good agreement with experiment.

  • 228.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung (2003)

  • An analytical method for calculation and evaluation of thermodynamic properties of alkali metals under the influence of impurity atom has been developed based on quantum statistical theory with correlated Einstein model. Mean square relative displacement (MSRD), effective local force constants, correlated Einstein frequency and temperature of pure alkali metals and those with impurity have been calculated and compared each to other.

Browsing by Author Nguyen, Van Hung

Jump to: 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
or enter first few letters:  
Showing results 6 to 25 of 26
  • 102.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Nguyen, Cong Toan; Hoang, Thi Khanh Giang (2010)

  • Analytical expressions for the ratio of the root mean square fluctuation in atomic positions on the equilibrium lattice positions and the nearest neighbor distance and the mean melting cgryes of bcc binary alloys haye been derived. This melting curve provides information on Lindemann's melting temperatures of binary alloys with respect to any proportion of constituent elements and on their euctectic points. Numerical results for some bcc binary alloys are found to be in agreement with experiment.

  • 115.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Nguyen, Cong Toan; Nguyen, Bao Trung; Ngo, Hoang Giang (2008)

  • Analytical expressions for the Morse potential parameters of diamond crystals have been derived. They contain the energy of sublimation, the compressibility and the lattice constant. Numerical calculations have been carried out for Si and Sn, and the result reflect fundamental calcultion of the anharmonic correlated effective potential parameters have been used for calculation of the anharmonic correlated effective potentials of these crystals in XAFS theory showing clearly anharmonic effects.

  • 237.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Dao, Xuan Viet (2003)

  • A new procedure for calculation of the Morse potential parameters of hexagonal closed packed (hcp) crystals has been developed using the energy of sublimation, the compressibility and the lattice constant. The derived equation of state and the elastic constants computed using the obtained Morse parameters agree with the experimental ones. This shows that the Morse dunction can be applied validly to the problems involving any type of deformation and atomic interaction in the hcp crystals.

  • 49.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Trinh, Thi Hue; Nguyen, Ba Duc (2015)

  • In this work, Morse potential parameters of bcc crystals have been calculated based on the calculation of volume per atom and atomic number in each elementary cell, as well as the energy of sublimation, the compressibility and the lattice constant. They are used for studying the anharmonic interatomic effective potential, local force constant in XAFS (X-ray Absorption Fine Structure) theory. Numerical results for Fe, W and Mo are found to be in good agreement with experiment and with those of other theories.

  • 3.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Trinh, Thi Hue; Nguyen, Ba Duc (2015)

  • In this work, Morse potential parameters of bcc crystals have been calculated based on the calculation of volume per atom and atomic number in each elementary cell, as well as the energy of sublimation, the compressibility and the lattice constant. They are used for studying the anharmonic interatomic effective potential, local force constant in XAFS (X-ray Absorption Fine Structure) theory. Numerical results for Fe, W and Mo are found to be in good agreement with experiment and with those of other theories.

  • 201.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Nguyen, Thi Thu Hoai; Le, Hai Hung (2004)

  • A new procedure for calculation and evaluation of XAFS cumulants of fee crystals containing impurity atom has been developed based on the quantum statistical theory with correlated Einstein model. Analytical expressions for the effective local force constants, correlated Einstein frequency and temperature, first cumulant or net thermal expansion, second cumulant or Debye Waller factor and third cumulant of fee crystals containing impurity atom have been derived. Morse potential parameters of pure crystals and those with impurity included in the derived expressions have been calculated. Numerical results for Cu. Ni. Ni-Cu are found to be in good agreement with experiment

  • 62.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Duong, Anh Tuan; Trinh, Duc Thien; Nguyen, Dang Phu; Danh, Bich Do; Pham, Van Vinh (2012)

  • CdTe quantum dots dispersed in water were prepared successfully by the microwave irradiation method. The influence of the pH value of the solution precursor, irradiation time and microwave power on the structure, size and optical properties of CdTe quantum dots was investigated. The fluorescence of CdTe quantum dots studies were illustrated that the samples which were synthesized at pH value of 7 exhibited the best fluorescence. The absorption, fluorescence spectra and TEM images showed that the microwave power and the irradiation time influenced significantly on the size of CdTe quantum dot as well as their optical properties. The fluorescence spectra were red-shift with the increase...

  • document(38).pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Bui, Thi Viet Ha; Dinh, Thuy Hang (2016)

  • An efficient method was established for isolation of bifidobacteria from fecal samples of breast-fed infants. The method was based on the combination of Hungate technique applied on anoxic semi-liquid agar tubes, instead of double layer agar plates. Four growth media including BFM, BIM25, MRS and 385 were compared for the isolation efficiency on the basis of Hungate technique. Thus, among 30 isolates obtained from fecal samples of 14 breast fed infants of different ages under 1 year only eight bifidobacteria-like isolates were selected based on cell morphology and fermentation motif. It is revealed that Hungate technique with the use of anaerobic MRS and BFM media was more efficient f...

  • 96.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Bui, Van Loat (2009)

  • The paper resented the results of assessing internal dose for 131I by the direct method for Vietnamese objects that was issued in the Intercomparison Program of IAEA. The results on experimental measurements, caculating intake (I) or 131I to thyroid by the specializing system for measuring thyroid activity, and committed effective dose E(50) using the specializing code of LUDEP 2.0 were shown that the results carrying out at the Nuclear Research Institute were goof and were in accordance with the those of the authors in other laboratories in the world.

  • 117.pdf.jpg
  • Article


  • Authors: Bui, Van Loat; Nguyen, Van Hung; Hoang, Sy Minh Phuong (2010)

  • At present, thickness measurement of materials based on effect of backscattering gamma-ray has been widely used in industry in our country. The report presented research in measuring thickness of some materials such as paper, plastic, aluminum and steel with using the dedicated system of MYO-101, having scintillation detector of YAP(Ce) and gamma-ray of 60 keV of Am-241 source, by Monte-Carlo simulation using the code of MCNP. The simulation was checked by experimental measurements. The results were shown that they were in accordance with the range of error. This research has been useful for training activities with a view of human resowces development in the field of application of n...

  • 122.pdf.jpg
  • Article


  • Authors: Khong, Cat Cuong; Trinh, Duc Thien; Pham, Thu Nga; Nguyen, Van Minh; Nguyen, Van Hung (2009)

  • In this article, we report on the preparation of CdSe quantum dots (QDs) by sol-gel method and their optical properties. The average size of QDs is also estimated by using various ways, such as the Scherer’s formula. The Effros-Brus-Kayanum a's theoretical expression, TEM etc. The TEM images of samples show that the mean sizes of QDs are 4 nm. The mean sizes of QDs are smaller than that of other methods and arranging from 2 to 3.6 nm.

  • 132.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Tran, Trung Dung; Nguyen, Cong Toan (2006)

  • A new procedure for description and calculation of th EXAFS (Extended X-ray Absorption Fine Structure) cumulants for fee crystals containing an abitrary number n of dopant atoms have been developed. Analytical expressions for the l 8t, 2nd and 3rd cumulants have been derived.They depend on the number of dopant atoms and approach those derived by anharmonic correlated Einstein model, if all dopant atoms are taken out or replacing all the host atoms. Numerical results for Cu doped by Ni atoms based on the Morse potential show significant dependence of thermodynamic parameters of the substance on the number of dopant atoms and a reasonable agreement with experiment.

  • 209.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Tran, Trung Dung; Nguyen, Cong Toan (2004)

  • A new procedure for description and calculation of the interaction potential and force constants for fee crystals containing an arbitrary number n of impurity atoms have been developed. Analytical expressions for the effective atomic interaction potential, the single-bond and effective spring constants have been derived. They depend on the number of the impurity atoms and approach those derived by using anharmonic correlated Einstein model, if all the impurity atoms are taken out or they replace all the host atoms. Numerical results for Ni doped by Cu atoms show significant changes of the interact on potential and spring constants of the substance if the number of impurity ato...

  • 125.pdf.jpg
  • Article


  • Authors: Bui, Van Loat; Nguyen, Van Quan; Le, Tuan Anh; Tran, The Anh; Nguyen, The Nghia; Nguyen, Van Hung (2009)

  • Radioactive sources which used to study were the standardized radioactive of common monoenergetic radionuclide Cs137 and standardized multigamma Co60, Ba133, Eu152. Determination of the absolute efficiency curve and energy resolution as a function of energy of GEM40P4 HPGe spectrometer are presented in this paper.

  • 59.pdf.jpg
  • Article


  • Authors: Le, Huynh My Van; Nguyen, Van Hung (2014)

  • In this paper, we study the systems of generalized quasiequilibrium problems which includes as special cases the generalized vector quasi-equilibrium problems, vector quasiequilibrium problems, and establish the existence results for its solutions by using fixed-point theorem. Moreover, we also discuss the closedness of the solution sets of systems of generalized quasiequilibrium problems. As special cases, we also derive the existence results for vector quasiequilibrium problems and vector quasivariational inequality problems. Our results are new and improve recent existing ones in the literature.

  • TELEVISION AUDIENCE MEASUREMENT & APPLYING ON ADVERTISING ACTIVITY IN VIETNAM.pdf.jpg
  • Thesis


  • Authors: Nguyen, Van Hung;  Advisor: Nguyen, Thi Hong Hanh (2018)

  • Television Audience Measurement is a popular field of study in the world but quite new for the Vietnam. The objective of the research is introduce a new and effective approach to the study of television audience to help advertiser/media agency/broadcaster understand the audience characteristics, habits, tastes… from which they can build and develop the effective and optimal communications strategies.

  • 184.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung; Ho, Khac Hieu; Nguyen, Cong Toan (2006)

  • A new procedure for calculation and analysis of thermodynamic and correlation effects of bcc crystals under in fluence of dopant atom in the X-ray Absorption Fine Structure (XAFS) has been developed. Analytical expression for the Displacement-displacement Correlation Function (DCF) CR has been derived based on the derived Mean Square Relative Displacement (MSRD) 2 Ơ2 and Mean Square Displacement (MSD) u of bcc crystals containing dopant atom. Numerical calculations have been carried out for Fe doped by w and by Cr atom. They are found to be in good agreement with experiment.

  • 228.pdf.jpg
  • Article


  • Authors: Nguyen, Van Hung (2003)

  • An analytical method for calculation and evaluation of thermodynamic properties of alkali metals under the influence of impurity atom has been developed based on quantum statistical theory with correlated Einstein model. Mean square relative displacement (MSRD), effective local force constants, correlated Einstein frequency and temperature of pure alkali metals and those with impurity have been calculated and compared each to other.