The UO₂ ex-ADU powder preparation and pellet sintering for optimum efficiency: experimental and modeling studies

Hung, Nguyen Trong,Thuan, Le Ba,Van Tung, Nguyen,Thuy, Nguyen Thanh,Lee, Jin-Young,Jyothi, Rajesh Kumar ELSEVIER 2017 JOURNAL OF NUCLEAR MATERIALS Vol.496 No.-

<P><B>Abstract</B></P> <P>The UO<SUB>2</SUB> nuclear fuel pellet process for light water reactors (LWR) includes the conversion of uranium hexafluoride (UF<SUB>6</SUB>) into UO<SUB>2</SUB> powder and the fabrication of UO<SUB>2</SUB> pellets from such UO<SUB>2</SUB> powder. In the paper, studies on UO<SUB>2</SUB> pellet process from ammonium diuranate-derived uranium dioxide powder (UO<SUB>2</SUB> ex-ADU powder) were reported. The UO<SUB>2</SUB> ex-ADU powders were converted from ADU at various temperatures of 973 K, 1023 K and 1073 K and then UO<SUB>2</SUB> pellets prepared from the powders were sintered at temperatures of 1923 K, 1973 K and 2023 K for times of 4 h, 6 h and 8 h. Response surface methodology (RSM) based on quadratic central composite design (CCD) type of face centered (CCF) improved by Box and Hunter was used to model the UO<SUB>2</SUB> pellet process, using MODDE 5.0 software as an assessing tool. On the base of the proposed model, the relationship between the technological parameters and density of the UO<SUB>2</SUB> pellet product was suggested to control the UO<SUB>2</SUB> ex-ADU pellet process as desired levels.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Modeling and experimental studies were made on UO<SUB>2</SUB> ex-ADU powder preparation. </LI> <LI> Time, temperature studies made on UO<SUB>2</SUB> ex-ADU powder. </LI> <LI> Parameters were optimized through modeling the UO<SUB>2</SUB> pellet processes using RSM based CCD. </LI> <LI> The quadratic mathematical model for the pellet density was determined. </LI> <LI> The proposed model was shown a good agreement with the experimental data. </LI> </UL> </P>

Spatial Interpolation of Meteorologic Variables in Vietnam using the Kriging Method

( Xuan Thanh Nguyen ),( Ba Tung Nguyen ),( Khac Phong Do ),( Quang Hung Bui ),( Thi Nhat Thanh Nguyen ),( Van Quynh Vuong ),( Thanh Ha Le ) 한국정보처리학회 2015 Journal of information processing systems Vol.11 No.1

This paper presents the applications of Kriging spatial interpolation methods for meteorologic variables, including temperature and relative humidity, in regions of Vietnam. Three types of interpolation methods are used, which are as follows: Ordinary Kriging, Universal Kriging, and Universal Kriging plus Digital Elevation model correction. The input meteorologic data was collected from 98 ground weather stations throughout Vietnam and the outputs were interpolated temperature and relative humidity gridded fields, along with their error maps. The experimental results showed that Universal Kriging plus the digital elevation model correction method outperformed the two other methods when applied to temperature. The interpolation effectiveness of Ordinary Kriging and Universal Kriging were almost the same when applied to both temperature and relative humidity.

Spatial Interpolation and Assimilation Methods for Satellite and Ground Meteorological Data in Vietnam

Do, Khac Phong,Nguyen, Ba Tung,Nguyen, Xuan Thanh,Bui, Quang Hung,Tran, Nguyen Le,Nguyen, Thi Nhat Thanh,Vuong, Van Quynh,Nguyen, Huy Lai,Le, Thanh Ha Korea Information Processing Society 2015 Journal of information processing systems Vol.11 No.4

This paper presents the applications of spatial interpolation and assimilation methods for satellite and ground meteorological data, including temperature, relative humidity, and precipitation in regions of Vietnam. In this work, Universal Kriging is used for spatially interpolating ground data and its interpolated results are assimilated with corresponding satellite data to anticipate better gridded data. The input meteorological data was collected from 98 ground weather stations located all over Vietnam; whereas, the satellite data consists of the MODIS Atmospheric Profiles product (MOD07), the ASTER Global Digital Elevation Map (ASTER DEM), and the Tropical Rainfall Measuring Mission (TRMM) in six years. The outputs are gridded fields of temperature, relative humidity, and precipitation. The empirical results were evaluated by using the Root mean square error (RMSE) and the mean percent error (MPE), which illustrate that Universal Kriging interpolation obtains higher accuracy than other forms of Kriging; whereas, the assimilation for precipitation gradually reduces RMSE and significantly MPE. It also reveals that the accuracy of temperature and humidity when employing assimilation that is not significantly improved because of low MODIS retrieval due to cloud contamination.

Spatial Interpolation and Assimilation Methods for Satellite and Ground Meteorological Data in Vietnam

( Khac Phong Do ),( Ba Tung Nguyen ),( Xuan Thanh Nguyen ),( Quang Hung Bui ),( Nguyen Le Tran ),( Thi Nhat Thanh Nguyen ),( Van Quynh Vuong ),( Huy Lai Nguyen ),( Thanh Ha Le ) 한국정보처리학회 2015 Journal of information processing systems Vol.11 No.4

This paper presents the applications of spatial interpolation and assimilation methods for satellite and ground meteorological data, including temperature, relative humidity, and precipitation in regions of Vietnam. In this work, Universal Kriging is used for spatially interpolating ground data and its interpolated results are assimilated with corresponding satellite data to anticipate better gridded data. The input meteorological data was collected from 98 ground weather stations located all over Vietnam; whereas, the satellite data consists of the MODIS Atmospheric Profiles product (MOD07), the ASTER Global Digital Elevation Map (ASTER DEM), and the Tropical Rainfall Measuring Mission (TRMM) in six years. The outputs are gridded fields of temperature, relative humidity, and precipitation. The empirical results were evaluated by using the Root mean square error (RMSE) and the mean percent error (MPE), which illustrate that Universal Kriging interpolation obtains higher accuracy than other forms of Kriging; whereas, the assimilation for precipitation gradually reduces RMSE and significantly MPE. It also reveals that the accuracy of temperature and humidity when employing assimilation that is not significantly improved because of low MODIS retrieval due to cloud contamination.

Knowledge Sharing Influence on Innovation: A Case of Textile and Garment Enterprises in Vietnam

HOA, Nguyen Dinh,THANH, Vu Ba,MAI, Vu Thanh,TUNG, Le Van,QUYEN, Huynh Vo Thuc Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.7

The study seeks to investigate the relationship between knowledge sharing and innovation in garment and textile enterprises. While previous research has found many factors influencing knowledge sharing, little research has been done about the influence of knowledge sharing on innovation in enterprises in developing countries like Vietnam. In particular, the textile industry plays an important role in export, but outsourcing is accounting for a high proportion of trade; it is necessary to increase innovation in order to increase the competitive advantage by internal capacity. The data is collected from a survey of 245 employees at 20 textile and garment enterprises in Vietnam to study the knowledge sharing influence on innovation. The methodology includes pilot study and quantitative method. The pilot study tests the questionnaire on the respondents. The quantitative method applies SEM analysis to measure the knowledge sharing influence on innovation. The results identify eight factors that positively impact knowledge sharing: rewarding, teamwork, management support, joy of knowledge sharing, communication, trust, commitment, and information technology. This study also shows that knowledge sharing affects innovation. The main findings are discussed for textile and garment enterprises to apply innovative capacity in the context of increasing global integration.

Quality Evaluation of Moutan Cortex Radicis Using Multiple Component Analysis by High Performance Liquid Chromatography

Yan Ding,Enqi Wu,Jianbo Chen,Huu Tung Nguyen,Thi Ha Do,Kyung Lae Park,KiHwan Ba,Young Ho Kim,강종성 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.10

A simple high performance liquid chromatographic method was developed to evaluate the quality of Moutan Cortex Radicis based on chromatographic fingerprints that characterize eight pharmacological compounds, namely, gallic acid, paeoniflorin, galloyl paeoniflorin, benzoic acid, quercetin, benzoylpaeoniflorin, paeoniflorigenone, and paeonol. These compounds were identified by their characteristic UV profiles and the mass spectroscopy data, and their contents were determined by HPLC. The chromatographic separation was performed on a C18 column by gradient elution with 0.05% formic acid in water and acetonitrile. The methodological validation gave acceptable linearities (r = 0.9996) and recoveries (ranging from 99.4∼103.1%). The limits of detection (LOD) of these compounds ranged from 10 to 30 μg/mL. The representative chromatographic fingerprints of Moutan Cortex Radicis were obtained by analyzing 20 batches of samples collected from markets in Korea and China. For the efficient evaluation of quality for the commercial Moutan Cortex Radicis it is recommended that the total content of the six characteristic compounds should contain more than a minimum of 2% and that the content of total paeoniflorin and paeonol should exceed a minimum of 1.5% of dry weight of Moutan Cortex Radicis.