Chitosan을 Bacillus pumilus BN-262 유래의 chitosanase로 처리한 경우에는 tnmer, tetramer, pentamer가 전체 올리고당 중 64.3%에 달하는 비교적 저분자의 chitooligosaccharides로 구성된 chitooligosaccharidesⅠ을 얻을 수 있었다 그러나 Trichoderma viride 유래의 chellulase로 처리한 경우에는 중합도 7 이상의 것이 전체 올리고당 중 49.3%에 달하는 상대적으로 분자량이 큰 chitooligosaccharides로 구성된 chitooligosaccharideⅡ를 얻을 수 있었다. 따라서 생리적 기능성이 높은 hexamer 이상의 chitooligosaccharides를 얻기 위해서는 chitosanase의 처리 조건을 달리하여 분해가 덜 일어나도록 하거나 cellulase와 같은 효소를 처리함으로써 chitosan의 부분적인 분해를 유도하는 것이 필요하다고 판단되었다. Chitin과 chitooligosaccharides의 응집성에 대하여 조사하였다 고분자의 chitosan은 2가 음이온을 함유하는 무기화합물 및 고분자의 유기화합물과 반응하여 응집이 일어났다. 분해가 많이 일어난 chitooligosaccharideⅠ은 무기물질과는 침전하지 않았으나 고분자화합물을 함유하는 유기화합물과는 반응하여 침전이 일어났다. 분해가 적게 일어난 chitooligosaccharideⅡ는 2가 음이온을 함유하는 무기화합물 및 고분자의 유기화합물과 반응하여 침전이 일어났다
The transportation of spent nuclear fuel between management stages is expected, and the transportation workers may be exposed to radiation. When transporting spent nuclear fuel, the ALARA principle must be observed for the workers. The objective of this study is to assess a radiation dose for workers transporting spent nuclear fuel using metal overpacks. For this objective, the cask to be handled was selected and the radiation source term was set. Then, the radiation exposure scenario for the transportation workers was defined. Finally, the dose rates for each location of operation were assessed using Monte Carlo simulations, and collective doses were derived for each operation considering the radiation exposure scenario. Each worker performed 11 operations to transport spent nuclear fuel to other facilities and was exposed to a total of 1.138 man-mSv. The operation of removing the bottom shield ring resulted in the highest radiation exposure at 0.503 man-mSv. In contrast, the operation of installing the impact limiter resulted in the lowest radiation exposure at 0.0009 man-mSv. The results of this study can be used to strengthen radiation protection measures for workers transporting spent nuclear fuel in dry storage facilities using metal overpacks.
In Korea, most temporary storage facilities for spent nuclear fuel are nearing saturation. As an alternative to this, the 2nd basic plan for high-level radioactive waste management specified the operation plan of dry interim storage facility. Meanwhile, the NSSC No. 2021-19 stipulates that it is necessary to evaluate the possibility and potential effect of accident before operating interim storage facility. Therefore, this study analyzed the categories of accident scenarios that may occur in dry storage facility as part of prior research on this. We investigated the case of categorization of dry storage facility accident scenarios of IAEA, NRC, KAREI, and KINS. The IAEA presented accident scenarios that could occur in on-site dry storage facility operated with silo and cask method. NRC has classified accident scenarios in dry storage facility and estimated the probability of accidents for each. KAERI and KINS selected major accident scenarios and analyzed the processes for each, in preparation for the introduction of dry storage facility in Korea in the future. Overall, a total of 10 accident scenarios were considered, and the scenarios considered by each institution were different. Among 10 scenarios, cask drop and aircraft collision were included in the categorization of most institutions. The results of this study can be used as basic data for cataloging accidents subject to safety evaluation when introducing dry interim storage facility in Korea in the future.
In Korea, the construction of dry storage facilities for spent nuclear fuel is being promoted through the 2nd basic plan for high-level radioactive waste management. When operating dry storage facilities, exposure dose assessment for workers should be performed, and for this, exposure scenarios based on work procedures should be derived prior. However, the dry storage method has not yet been sufficiently established in Korea, so the work procedure has not been established. Therefore, research is needed to apply it domestically based on the analysis of spent nuclear fuel management methods in major overseas leading countries. In this study, the procedure for receiving and storing spent nuclear fuel in a concrete overpack-based storage facility was analyzed. Among the various spent nuclear fuel management systems, the metal overpack-based HI-STAR 100 system and the concrete overpackbased HI-STORM 100 system are quite common methods in the United States. Therefore, in this study, work procedures were analyzed based on each final safety analysis report. First, the HI-STAR 100 overpack enters the facility and is placed in the transfer area. Remove the impact limiter of the overpack and install the alignment device on the top of the overpack. Place the HI-TRAC, an on-site transfer device, on top of the alignment unit and remove the lids of the two devices to insert the canister into the HI-TRAC. When the canister transfer is complete, reseat the lid to seal it, and disconnect the HI-TRAC from the HI-STAR 100. Raise the canister-loaded HI-TRAC over the alignment device on the top of the HI-STORM 100 overpack and remove the lids of the two devices that are in contact. Insert the canister into the HI-STORM 100 and reseat the lid. The HI-STORM 100 loaded with spent nuclear fuel is transferred to the designated storage area. In this study, the procedure for receiving and storing spent nuclear fuel in a concrete overpack-based storage facility was analyzed. The main procedure was the transfer of canisters between overpacks, and it was confirmed that HI-TRAC was used in the work procedure. The results of this study can be used as basic data for evaluating the exposure dose of operating workers for the construction of dry storage facilities in Korea.
This paper designed modular agricultural robotic platform capable of a variety of agricultural tasks to address the problems caused by a decline in agricultural populations and an increase in average age. We propose a modular robotic platform that can perform many tasks required in field farming by replacing only work modules with common robotic platforms. This platform is capable of steering while driving on four wheels in an upland environment where farm work is performed, and an attitude control module is attached to each drive module to control the attitude of the platform. In addition, the width of the platform is designed to be variable in order to operate in various ridges according to the crop cultivation method. Finally, we evaluated five items: variable width, gradient, attitude control angle, step and road speed in order to carry out the farming industry while maintaining a stable posture.
치과 콘빔 전산화단층 검사 시 갑상선 부위의 방사선 피폭선량을 최소화하기 위하여 보루스 (Bolus)를 이용한 차폐체를 제작하고, 방사선 차폐 효과와 영상의 적정성을 평가하였다. 치과용 콘빔 전산화단층검사 장비를 사용하여 치과방사선 두부 팬텀을 대상으로 갑상선의 좌, 우측 부위에 유리선량계를 부착시켜 방사선량을 측정하였다. 차폐체의 두께를 각각 10 mm, 20 mm, 30 mm로 다르게 하여 각 차폐체별로 흡수선량을 측정하여 차폐체를 사용하지 않았을 경우와 비교하였다. 8명의 평가자가 진료영상의 적정성을 여부를 평가하였다. 왼쪽 갑상선 부위에 30 mm Bolus 차폐체를 사용한 경우에는 결과값이 평균 342.67 μ㏉로 Bolu s 차폐체를 사용하지 않고 측정한 결과값의 평균 431.22 μ㏉보다 20.7% 감소하였고, 오른쪽 갑상선 부위에 30 mm Bolus 차폐체를 사용한 경우에는 평균 424.56 μ㏉로 21.9%의 선량감소효과를 보였다. 진료 영상의 적정성은 평가자 모두 사용 가능하다 판단하였다. 결론적으로, 치과 콘빔 전산화단층검사 시 갑상선 부위의 방사선 피폭선량을 최소화하기 위해 제작된 Bolus 차폐체는 장해음영 없이 적정한 진단 영상 처리가 가능하고, 방사선차폐 효과가 있어 유용한 차폐체로 적용 가능할 것으로 사료된다.
Numerical Weather Prediction (NWP) models such as the Weather Research and Forecasting (WRF) model are essential for forecasting one-day-ahead solar irradiance. In order to evaluate the performance of the WRF in forecasting solar irradiance over the Korean Peninsula, we compared WRF prediction data from 2008 to 2010 corresponding to weather observation data (OBS) from the Korean Meteorological Administration (KMA). The WRF model showed poor performance at polluted regions such as Seoul and Suwon where the relative Root Mean Square Error (rRMSE) is over 30%. Predictions by the WRF model alone had a large amount of potential error because of the lack of actual aerosol radiative feedbacks. For the purpose of reducing this error induced by atmospheric particles, i.e., aerosols, the WRF model was coupled with the Community Multiscale Air Quality (CMAQ) model. The coupled system makes it possible to estimate the radiative feedbacks of aerosols on the solar irradiance. As a result, the solar irradiance estimated by the coupled system showed a strong dependence on both the aerosol spatial distributions and the associated optical properties. In the NF (No Feedback) case, which refers to the WRF-only stimulated system without aerosol feedbacks, the GHI was overestimated by 50–200 W m-2 compared with OBS derived values at each site. In the YF (Yes Feedback) case, in contrast, which refers to the WRF–CMAQ two-way coupled system, the rRMSE was significantly improved by 3.1–3.7% at Suwon and Seoul where the Particulate Matter (PM) concentrations, specifically, those related to the PM10 size fraction, were over 100 g m-3. Thus, the coupled system showed promise for acquiring more accurate solar irradiance forecasts.
This study was conducted with the aim of evaluating the antibiotic effects of leaves, stems, and roots in yacon (Smallanthus sonchifolius). Antibacterial activity of leaf extract by disk diffusion method with Bacillus subtilis and Escherichia coli respectively showed 13.3 and 13.75mm diameters of clear zone. There was no significant difference between the stems and leaves. The minimum inhibitory concentration of leaves’ heating and agitation extraction showed a restrain of strain at 1mg/ml, but the stems and root extract did not appear. Yacon is a functional antibacterial material, and methanol extraction is more effective than water. This research was to investigate the growth stage of collection has the most effective antibacterial effects. It has collected yacon's leaves from June to October, which is an appropriate time for collection right before reaping. Yacon leaf has antibacterial effects on Bacillus subtilis, Escherichia coli, Enterococcus faecium, and Salmonella enteritifis. There were no significant differences by the growth stage of collection. Leaves collected in July are high in phenol which helps in sulfating activity works well considering the high scavenging capability of DPPH. Leaves collected in September are high in total flavonoid.
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 : 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.
Atrial fibrillation (AF) is a common, benign, and transient type of supraventricular arrhythmia encountered during the early postoperative period after a pulmonary resection. However, it sometimes might result in hemodynamic deterioration. We report on a case of new-onset atrial fibrillation in a 74-year-old male patient after right lower lobectomy, which was not controlled with intermittent bolus injection of esmolol and diltiazem. Successful pharmacological cardioversion was achieved with intravenous (6 mg/hr for 2 hours) followed by oral (90 mg q day) diltiazem 20 hours after this treatment. The literature on the risk factors and management of atrial fibrillation after pulmonary resection is reviewed.
TiO2- and SiO2-supported Co3O4, Pt and Co3O4-Pt catalysts have been studied for CO and C3H8 oxidations at temperatures less than 250℃ which is a lower limit of light-off temperatures to oxidize them during emission test cycles of gasoline-fueled automotives with TWCs (three-way catalytic converters) consisting mainly of Pt, Pd and Rh. All the catalysts after appropriate activation such as calcination at 350℃ and reduction at 400℃ exhibited significant dependence on both their preparation techniques and supports upon CO oxidation at chosen temperatures. A Pt/TiO2 catalyst prepared by using an ion-exchange method (IE) has much better activity for such CO oxidation because of smaller Pt nanoparticles, compared to a supported Pt obtained via an incipient wetness (IW). Supported Co3O4-only catalysts are very active for CO oxidation even at 100℃, but the use of TiO2 as a support and the IW technique give the best performances. These effects on supports and preparation methods were indicated for Co3O4-Pt catalysts. Based on activity profiles of CO oxidation at 100℃ over a physical mixture of supported Pt and Co3O4 after activation under different conditions, and typical light-off temperatures of CO and unburned hydrocarbons in common TWCs as tested for C3H8 oxidation at 250℃ with a Pt-exchanged SiO2 catalyst, this study may offer an useful approach to substitute Co3O4 for a part of platinum group metals, particularly Pt, thereby lowering the usage of the precious metals.
This study was carried out to determine the optimum harvest date of unshelled immature peanuts and dried kernels from 60 to 120 days after flowering. Fresh pod yield of spanish-type variety, 'Shaedl-tangkong(SD)' reached a peak of 9,140kg/ ha at 70 (days after flowering(Aug. 13) while that of virginia-type variety, 'Daepoongtangkong(DP)' reached a peak of 8,820kg/ha at 90 days(Sept. 11) after flowering. SD and DP showed maximum fresh kernel yield of 6,090 and 6,470kg/ha at 90 days after flowering (Sept. 11), respectively, while dry kernel yield reached a peak of 3,300 and 3,720kg/ha at 110 days(Oct. 1), respectively. Oil content of SD and DP were the highest at 90 days and 100 days after flowering, respectively and the oil content of two varieties increased rapidly from 60 to 90 days. Tannin content of the seed hull of SD increased continuously until 110 days after flowering while that of DP maximized at 100 days. The tannin content of the two varieties increased rapidly from 60 to 100 days. Total sugar of SD and DP showed highest content at 60 days and 70 days after flowering, respectively and suger content decreased very rapidly until 80 days and after that sugar content kept nearly constant. Oil, tannin and total sugar content of spanish-type SD were higher than those of virginia-type DP.