사용후핵연료 금속전환체의 저장 안정성을 높이기 위해 금속전환체의 주성분인 금속우라늄과 산화 안정화물질로 알려져 있는 Nb을 첨가하여 모의 금속전환체 합금을 제작하였다. 모의 금속전환체 합금을 온도구간에서 순수 산소분위기로 산화시험을 수행하고 무게증가를 열중량 분석기(TGA)로 측정하였다. 산화 실험결과 U-Nb 모의 금속전환체는 순수 금속우라늄에 비하여 상당한 산화 저항성을 가졌다. U-Nb 합금의 경우 Nb의 함량 에 따라 각각 온도가 일 경우에는 1.61, 7.78, 11.76, 20.14배 , 에서 1.45, 5.98, 10.08, 11.15배, 에서 1.33, 4.82, 8.87, 6.84배 순수 금속우라늄에 비해 산화저항성이 향상되는 것으로 나타났다. 또한 Nb 합금에 대한 활성화에너지는 kcal/mol 로 나타났다.

The Pt-Ru/Carbon as an anode catalyst supported on the commercial activated carbon (AC) having high surface area and micropore was characterized for application of Direct Methanol Fuel Cell (DMFC). The Pt-Ru/AC anode catalyst used in this experiment showed the performance of 600 mA/cm2 current density at 0.3 V. The borohydride reduction process using NaBH4, denoted as a process A, showed much higher current and power densities than process B prepared by changing the reduction and washing process of process A. The particle sizes are strongly affected by the reduction process than the specific surface area of raw active carbon and the sizes are almost constant when the specific surface area of carbon are over than the 1200 m2/g. Smaller particle size of catalyst and more narrow intercrystalite distance increased the performance of DMFC.

Composite adsorbents were prepared by mixing water plant sludge with phenolic resin having the ratio of 1 : 1, 1 : 2, and 1 : 3 respectively, curing from 100℃ to 170℃ under N2 atmosphere, and then activating with N2 at 700℃. Thermal property, specific surface area and morphology of the composite adsorbents as well as their precursors were measured by TGA, BET and SEM respectively. Removal efficiency of the composite adsorbents to NH4+ and TOC was compared with those of commercial zeolite and activated carbon. The adsorbents presented very promising TOC removal efficiency of 98%, which was identical level to that of commercial activated carbon while they displayed removal efficiency, only 32%, of NH4+. Therefore, this composite adsorbent considered as the alternative material of commercial activated carbon, used as an expensive removal agent of organic substances and THM in water treatment plant and it also suggested a possibility of practical application in other processes.

The paper focuses on understanding fintech and the application of fintech in the banking sector in Vietnam. To solve this research objective, the authors analyze fintech development trends, especially the fintech application in the banking sector in Vietnam. To improve the quality of fintech services at banks, the authors conducted consideration of factors affecting customers’ intention to use fintech services. To accomplish this, the authors collected data through a survey of 620 customers of the banks located in Ho Chi Minh City – the largest economic center in Vietnam. For the analytical method, the authors used multivariate regression to estimate the research model. Research results show that fintech service is very important for the banking sector in Vietnam. Moreover, this paper has achieved great success by identifying the factors that influence customers’ intention to use fintech services. Accordingly, the intention to use fintech (INT) services is positively affected by the perception of usefulness (PU), social impact (SI), customer trust (TRU), and perceived ease of use (PEU). Based on the results of this study, bank managers will have a basis to improve the quality of fintech services. Not only that, the results of this study are also valuable for policymakers and researchers.

The objective of this study is to enrich the literature by investigating the impact of introduction of index future trading on spot market returns and trading volume in Vietnam. Data used in this study mainly consist of daily VN30-Index and market trading volume series during the period from February 6th, 2012 to December 31st, 2019. Using OLS, GARCH(1,1) and EGARCH(1,1) models, the empirical findings consistently confirm that the introduction of index future trading has no impact on the spot market returns. In addition, the results of the EGARCH(1,1) model indicate that the leverage effect on the spot market volatility is existence in HOSE. Specifically, bad news has a greater effect on the market volatility than good news of the same size. Moreover, our empirical findings reveal that the introduction of index future contracts has the positive impact on the underlying market trading volume. Specifically, the trading volume of the post-index futures introduction increases by 7.5 percent compared with the pre-index futures introduction. Finally, the results obtained from the Granger causality test for the relationship between the spot market returns and the future trading activity confirm that only uni-directional causality running from the market returns to the future trading activity exists in HOSE.

The purpose of this study was to investigate the main source of contamination of dried red pepper by assessing microbial loads on red peppers, washing water, washing machines, harvesting containers, and worker gloves that had come in contact with the dried red pepper. To estimate microbial loads, indicator bacteria (total bacteria, coliform bacteria and Escherichia coli) and pathogenic bacteria (E. coli O157:H7, Salmonella spp., Listeria monocytogenes, and Clostridium perfringens) were enumerated. The results showed that the numbers of indicator bacteria increased significantly after washing red peppers compared with that before washing (p<0.05). Moreover, E. coli and Listeria spp. were recovered from the red peppers after washing and from the ground water used in the washing process. The number of indicator bacteria on red peppers dried in the green house was lower than that on red peppers dried in a dry oven (p<0.05). However, E. coli O157:H7, Salmonella spp., L. monocytogenes, and C. perfringens were not detected. These results suggested that a disinfection technique may be needed during the washing step in order to prevent potential contamination. In addition, hygienic practices during the drying step using the dry oven, such as establishment of an optimal temperature, should be developed to enhance the safety of dried red pepper.

Background : Ginseng is a perennial plant and damaged by various diseases and insect pests. The damage lowers harvest and quality. Accordingly, a chemical control system was made with the aim of effectively control gray mold, anthrax, and spotting disease which occur during growth period. fungicide resistance of gray mold rot was examined to find out whether the chemical control system can be used over the long term. Methods and Results : This experiment was conducted in three areas including Geumsan-gun, Yesan-gun, and Sejong city. The chemical control system was done to the plants of two years old or older. As for the order of the treatment, from the end of April to May Fludioxonil (A) and Pyraclostrobin (B) were used; from the mid-May to the end of July of growth stages Difenoconazole (C), Iminoctadinetris (albesilate) (D), Cyprodinil (E), Metconazole (F), Fluazinam (G) and Pyrimethanil (H); from August to September nonresidualizing polyoxinB + mancozeb (K); in November of hibernating period, Fenhexamid (I) and Carbendazim/diethofencarb (J) were used. As for the interval, from the end of April to the end of July the interval was 10 days, in August and September once a month, and twice in every ten days in November. The isolation of Botrytis cinerea for examination into mycelial growth inhibition rate was conducted to 4-year old ginseng in Geumsan, 5-year old in Yesan, and 3-year old in Sejong. In Geumsan, the mycelial growth inhibition rate to Botrytis cinerea was 75.5% - 100%. Every fungicides showed good rate of mycelial growth inhibition. The lowest rate was seen in fungicide B at 75.5%. K showed the prevention rate at 76.8%, D at 82.7%, and I at 82.2%, and other fungicides at 100%. In Sejong area, the hyphal prevention rate of Botrytis cinerea was 71.0% - 100%, indicating all fungicides show good rate of mycelial growth inhibition. The lowest rate was recorded by fungicide B at 71.1%, D at 81.1%, K at 85.4%, and I at 95.4%. Yesan area also showed similar results to those of Geumsan and Sejong. Conclusion : Botrytis cinerea was isolated from ginseng and mycelial growth inhibition effect was examined in concentration of 11 kinds of fungicides. In all three areas where chemical control system were applied, resistance was not found, suggesting that the chemical control system can be applied to control diseases of ginseng.

Background : Ginseng is a perennial plant and damaged by various diseases and insect pests. The damage lowers harvest and quality. In particular, gray mold rot occurs to plants of every year, growth duration, and hibernating stage, and decays leaves, stems, and roots, lowering the amount of harvest. This experiment was conducted with the aim of effectively preventing gray mold rot, and other major diseases such as anthrax and spotting disease, and establishing chemical control system. Methods and Results : This experiment was conducted in three areas including Geunsan-gun, Yesan-gun, and Sejong city. As for the procedure of medical treatment, from the end of April to early May of germination period, Fludioxonil and Pyraclostrobin were used. From the mid-May to the end of July of growth period, Difenoconazole, Iminoctadine tris (albesilate), Cyprodinil, Metconazole, Fluazinam, and Pyrimethanil were used. From August to September, non residualizing polyoxinB + mancozeb was used. In November of hibernating stage, Fenhexamid and Carbendazim/diethofencarb were used. As for the interval, from the end of April to the end of July the interval was 10 days, in August and September once a month, and twice in every ten days in November. The chemical control system effect was compared with conventional prevention. When chemical control system was used, stem spotting disease occurred at a lower rate of 0.34% than 1.2% of the conventional method. Leaf spotting disease occurred at a lower rate of 1.4% compared with 7.1% of the conventional method, and anthrax occurred at a lower rate by more than 10% than the conventional method. Stem gray mold rot occurred at a rate of 4.1% when the conventional method was used, but the rate stood at 5.3% in Geumsan, 8.9% in Yesan, 2.3% in Sejong when the prevention method was used, which suggest the chemical control system was effective. Conclusion : When chemical control system was applied to prevent major diseases of ginseng, spotting disease, anthrax, and gray mold occurred at lower rates compared with the case where the conventional method was used. The finding is that the chemical control system can be utilized to prevent major diseases of ginseng.

Background : The most problematic disease in Boxthorn is Anthracnose. New variety with Anthracnose-resistant is good for high yield and Safe fruit production in open field. Therefore it is necessary to develop a New variety with Anthracnose -resistant and high yield. Methods and Results : The new boxthorn line, CB10511-104 was selected from the cross between Cheongun (IT232599) and CB08456-113 to breed new variety with high yield and Anthracnose-resistant in 2011. Its preliminary yield test was performed from 2012 to 2013 and the selected line was named Cheongyang 25. Its regional yield trials were carried out in Cheongyang, Yesan and Jindo for 3 years, from 2014 to 2016. Cheongyang 25 was registered as the new variety, Cheonggeum, in 2016. The specific characteristics were summarized as follows; Tree shape is open type and the leaf is round-lanceolate. The flowers are normal size and purple. The fruit is large size, round oval and yellowish red. The flowering was June 19 with medium flowering. Number of sprout branch by pruning was generated more than the check variety, Cheongmeong. The infection rates on leaves to Eriophys macrodonis Keifer was as strong as 39.6 percent. Anthracnose on fruits in open field was slightly similare compared to the check variety, but check variety was Anthracnose-resistant. The content of betaine and free sugar in dried-fruits were higher than that of the check variety. The dried-fruit yield was decreased about 17 percent in open field. Conclusion : This variety ‘Cheonggeum’ was suitable for cultivation in open field because of Anthracnose-resistant. It is necessary the companion variety, Cheonghong, because of self-incompatible.

사이클로트론에서 발생되는 핵반응은 불필요한 중성자를 발생시키며, 이로 인해 주변 물질들이 방사화 되게 된다. 방사화된 물질은 방사선피폭의 원인으로, 공기가 방사화 되었을 경우 인체에 흡입되어 내부피폭을 발생 시킨다. 이에 본 연구에서는 16.5 MeV의 초소형 사이클로트론의 운영에 따른 내부 공기의 방사화를 분석하고자 하였다. 실험결과 초소형 사이클로트론의 핵반응으로 발생되는 방사화는 종사자에게 매우 낮은 내부피폭을 발생시키는 것을 확인할 수 있었으며, 방사화로 인하여 발생된 방사능을 법적 기준치와 비교하여 보았을 때 기준치 이하로 법적 관리의 대상에서 제외 될 수 있음을 알 수 있었다. 하지만, 사이클로트론의 에너지가 높아짐에 따라 내부피폭의 위험성은 더욱 높아질 우려가 있으며, 이에 따라 국내에 정립 되어 있지 않는 방사선 관련 시설의 환기설비에 대한 기준이 필요할 것으로 사료되었다.

Background : Panax ginseng C. A. Meyer is a slow-growing perennial herb that is cultivated in shading condition. Climate change occur around the world that make a lot of problem such as damage of high temperature, drought, salinity and disease. The problems lower the ginseng productivity that cause income reduction of farmers. To achieve stable ginseng production, development of elite varieities resistant to abiotic and biotic stresses is consistently required. It is very time consuming process in order to develop new ginseng varieties because ginseng flowers after 3 years of growth. So, early selection system of elite line must be established. This study was conducted to develope efficient ginseng breeding techniques for early identification of heat or salinity resistance. Methods and Results : Ginseng petioles was soaked in mixed salts solution consisting of KNO3, KH2PO4, MgSO4․H2O in order to test resistant or susceptible salinity. The degree of resistance was quantified according to damage size. Also, ginseng lines transplanted in pot were treated 46℃ for 1 hour and then chlorophyll fluorescence reaction were measured in order to test resistant or susceptible high-temperature. The measured values such as Fm/Fo, Fv/Fm, Rfd were differentiated between resistant and susceptible line. Conclusion : Several lines showed that they are resistance to high temperature or salinity. The selected lines will be utilized for parents to develop new varieties.

Background : Water uptake and flow across cellular membranes is a fundamental requirement for plant growth and development, and plant water status is important not only for plant growth under favorable conditions but also for ability of a plant to tolerate adverse environmental conditions. Thus identification of plasma membrane water channel genes (aquaporins) in ginseng provides extensive information for functional studies and the development of markers for salinity stress tolerance. Methods and Results : For salinity treatment, the plants were grown for 4 weeks in culture medium gelled with 0.8% Phytoagar, and the old media were replaced with the fresh medium containing NaCl at 0, 50, 100, 200 and 400 mM, respectively. The samples for stress treated and non-stressed plants were collected from 6h to 72h, and frozen immediately into liquid nitrogen. According to the sequence information from the assembled transcripts, four primer pairs were designed from the aquaporin gene regions. In order to determine the pattern of aquaporins expression in ginseng seedlings to salinity stress, we conducted semi-quantitative RT-PCR. Conclusion : A tonoplast intrinsic protein 1 (TIP1)-type aquaporin is not only believed to be essential for plant life, but also to be beneficial for growth under salinity stress. Therefore, a deeper understanding of aquaporin genes in ginseng will be essential for crop improvement, which could help us to understand the molecular genetic basis for the ginseng genetic improvement and also provide the functional genetic resources for selective breeding and transgenic research.

Background : This study was carried out to understand the effect of seedling weight (SW) on growth and flowering in Panax ginseng. Methods and Results : The testing materials were Chunpoong (CP), Yunpoong (YP) and Jakyeongjong (JK). The increase of seedling (1yr) weight led to an increase in ratio of flowering plant and in number of flower per plant. The seed setting rate of two year-old plant (CP, YP, JK) increased with increase of SW at the planting time (PT) and number of flower per plant of three year-old plant (CP, YP) increased also. In the two year-old plant (JK), the ratio of three leaves per plant was 8.8, 19.6, 31.0, 42.0, 44.7 and 58.2%, respectively, in the SW of >0.6, 0.6~0.8, 0.8~1.0, 1.02~1.2, 1.2~1.4 and 1.4g<. The growth of ginseng plant was good with increase of SW at the PT. Conclusion : There was a highly positive correlation between seedling weight and flowering characteristics.

Background : Due to immature development of embryo in ripened berries, dehiscence process is required for the proper germination of ginseng seeds. Such process involves the preparation of the container with alternating layers of seed and moist sand. In order to make sand fully moist, water sprayer has been usually used by farmers, which is labor intensive, time consuming and causing uneven sand moisture. Methods and Results : In this study, we investigated the effects of different stratification methods on dehiscence ratio of ginseng seeds. Ginseng seeds were stratified for 90 days in a total of 12 different treatments and the dehiscence ratios were compared; drainage methods, drainage time, the ratio between ginseng seeds and sand, and etc. Seed stratification process was performed according to the guideline of ginseng GAP. One thousand ginseng seeds were used for each treatment. It was found that the average of dehiscence of the 12 treatments was 84.6 %. The highest dehiscence ratio (90.3 %) was observed in the seeds that were treated with water soaking, immediately followed by drainage. Higher ratio was also observed in the seeds that were soaked for 60 min, followed by drainage. Therefore, our findings indicate that ginseng seeds soaked in water less than 60 min could dehisce more efficiently than traditional method. Conclusion : Our study demonstrated that ginseng seeds that are subjected to water soaking and then drainage showed better ration of dehiscence. This method will eventually decrease the time and labor used for seed stratification.