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        검색결과 17

        1.
        2022.10 구독 인증기관·개인회원 무료
        In 2018, media reports raised issues related to radon released from building materials used as finishing materials in apartment houses. Accordingly, related ministries recommended not to use materials with a radiation index value exceeding 1. In order to calculate the radioactivity index, not only 226Ra producing radon (222Rn) but also 232Th and 40K radioactivity concentrations are required. To determine the concentration of the radionuclide, 40K is measured by a single gamma ray of 1,460.8 keV. And the 228Ac used to measure 232Th mainly utilizes gamma rays of 911.2 keV. However, 228Ac does not appear as a single peak unlike 40K, and appears as multiple peaks at various energies. Among them, gamma rays are emitted at a intensity of 0.83% at 1,459.2 keV, which is likely to interfere with 40K. Therefore, what is actually measured at 1,460.8 keV is theoretically a compound peak of 40K and 228Ac. Because the probability of emission at 1,459.2 keV (0.83%) is low, a low concentration of 232Th will result in little 40K radioactivity error. However, samples containing a high concentration of 232Th overestimate the 40K radioactive concentration, so correction is required. In this study, the IAEA standard substance (IAEA-RGTh-1) ontaining 232Th of actual high concentration was analyzed, and the results of the analysis without correction of 40K were compared and verified. As the 40K correction method, the 911.2 keV gamma-ray of 228Ac was used as the reference peak to separate the peak of 228Ac (1,459.2 keV) from the 40K (1,460.8 keV) mixed peaks. And, the coefficient value obtained by subtracting the peak of 228Ac (1,459.2 keV) from the 40K (1,460.8 keV) mixed peak was set to a pure peak of 40K and the radioactivity concentration was calculated therefrom. As a result of calculating the IAEA-RGTh-1 reference material without correction, it was confirmed that the 40K value was overestimated by about 38 times. If a measurement beyond the MDA of 40K is generated by 228Ac radioactivity because the 40K correction constant is not applied, there is an error in determining that there is 40K radioactivity. However, even if 40K radioactivity is overestimated due to the high concentration of 232Th, the degree to which this effect contributes to the radioactivity index is very small. However, as an analyst, 40K radioactivity correction should be made for more accurate analysis.
        2.
        2018.04 구독 인증기관·개인회원 무료
        The tobacco cutworm, Spodoptera litura(Fabricius) is serious pest that hurts tomato crops, actives long time of the year. Without pesticide applications, sex pheromone delta traps through experiment first and second half setting during cultural seasons in glasshouse and greenhouse. We investigated captured number of S. litura both in and out side of the two type of tomato cultivated greenhouse. As a result of investigation, captured number of S. litura showed the wave and three high peak typed graph throughout 10 months experiment. First time expression of S. litura was late April in outside installed traps and after that occurrence rate increased gradually until late August. In september, the rate decreased remarkably to middle November in both in and out side treated traps. The result also expressed that captured average number of S. litura in inside of the greenhouse were 8~10 units, and were 15~20units in outside treated traps. Simultaneous installation of internal and external sex pheromone traps succeeded in eliminating a considerable number of S. litura male moths, and the number of larvae was expected to be considerably reduced. Consequently in the experiment, captured male number of S. litura were about 220 units in outside, on the other about 80 of S. litura captured in inside installed traps.
        3.
        2017.10 구독 인증기관·개인회원 무료
        The attraction of the tomato whiteflies Trialeurodes vaporariorum, to four type of traps combined with a colored stickyboard and an light emitting lamp was investigated in 2016 in an tomato greenhouse. The colors of the sticky boardswere yellow and the peak wavelengths of the light emitting traps were 470nm(blue), 590nm(yellow) and 450~625nm(white).The type of traps was designed to directly illuminate the plants with an light emitting lamp and set along the lowerpart of the crops whose each sticky board was directed to the plants. This experiments showed that T. vaporariorumadults on average preferred (p>0.05) traps in blue lights(110±3.2adults/trap) compared to traps in yellow lights (71±1.4adults/trap)and white light traps(45±1.1adults/trap). The blue light trap(470nm) showed the most attractive to T. vaporariorum adults,followed by a similarly attraction to the yellow light trap(590nm), whereas the control (no light trap) was little attractiveto T. vaporariorum adults.
        4.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to identify milling characteristics depending on the number of a cutting roller’s air vent and blowing velocity to remove rice bran by the cutting type milling machine which can minimize the conventional milling process. The level of whiteness was found to be 38±0.5 in all the conditions, showing consistent whiteness levels during milling. The rice temperatures turned out to be 15.4 and 14.6oC which were rather low-level under the conditions of the cutting roller with 3 vents and blowing velocities of 35 and 40 m/s respectively. Cracked rice ratio was 2.13% under the conditions of the cutting roller with 3 vents and a blowing velocity of 35 m/s. Broken rice ratio showed the range of 0.762-0.869%, reflecting a low level. Turbidity after milling was decreased, as blowing velocity became faster. Energy consumption for milled rice production was decreased, as blowing velocity became faster. The optimum milling condition for cutting type milling machine depending on air vent number of cutting roller and blowing velocity was found to be 3 vents and 35 m/s.
        4,000원
        5.
        2017.04 구독 인증기관·개인회원 무료
        The tobacco cutworm, Spodoptera litura(Fabricius), is a major pest of tomato and frequently demands control measures. The timing of insecticide application is a key factor in determining its efficiency, so an experiment was designed to investigate this. Application of insecticide was based on three criteria: (i) the number of trap-caught moths in a Delta-type trap with a commercial sex pheromone lure placed in the center of the target area, soon after plant emergence; (ii) the percentage of plants exhibiting pinhole-type damage (10% or 20%) and (iii) the percentage of plants exhibiting shot hole-type damage (10% or 20%) compared to a check plot without any control measures. We found that the number of trap-caught moths was, compared to the other methods, the best means of deciding on insecticide application in tomato plant to control the tobacco cutworm. Using pheromone traps, we obtained the best performance of the insecticide Shinnago, causing > 90% larval mortality. Without insecticide application, tomato yield reduction due to the tobacco cutworm larva damage was 27%.
        6.
        2015.10 구독 인증기관·개인회원 무료
        Purpose: The study surveyed current customers’ sports sunglasses purchasing and wearing habits in order to evaluate the current situation and the ocular side effects of wearing sports sunglasses. Methods: The study surveyed 147 customers who had been using sports sunglasses. We investigated the customers’ motivations for wearing sunglasses, their vision correction method, purchasing store, brand selection, the awareness of warnings about the use of sports sunglasses, and the ocular side effects. We used SPSS version 18 (SPSS INC., Chicago, IL, USA) for the descriptive statistics, and an independent T-test and χ2 test (chi-square test) for the statistical analysis. Results: 73.5% of the customers wore sports sunglasses for glare reduction, which was the top motivation. 10.2% of them wore them for eye protection, 9.5% for visibility, 2.7% for the aesthetic effect, and 4.1% for other purposes. 43.5% usually purchased their sports sunglasses from online stores, while 25.3% bought them from optical stores, 12.2% from specialized shops for goggles, 10.2% from duty-free shops, and 4.1% from others. 44.5% of the customers who wore sports sunglasses had experienced side effects, while 55.5% had not experienced any side effects. 40.4% of the customers had read and been informed of the risks and care instructions for wearing sports sunglasses. However, 59.5% had not read or been informed of the risks and precautions by sellers. The survey shows that 53.5% of the customers who had been informed and had read the warnings about the use of sports sunglasses had purchased them from an optical store. Conclusions: Many customers had experienced side effects from the use of sports sunglasses. The majority of the customers had purchased sports sunglasses from online stores and had received insufficient information about the risks of wearing sports sunglasses. Customers who had purchased their sports sunglasses from an optical store had been informed of the risks of wearing sports sunglasses by an optician, and had experienced fewer side effects.
        16.
        2005.03 KCI 등재 서비스 종료(열람 제한)
        This experiment was conducted to investigate the soil nitrogen credit of biological nitrogen fixation (BNF) and the nitrogen balance of soybean in soybean-barley cropping systems. Soybean cultivar, Shinpaldalkong2 and barley cultivar, Olbori, were used in soybean mono-cropping (SM), barley monocropping (BM), and barley­soybean double cropping system. The barley-soybean double cropping system was treated with two different levels of nitrogen fertilizers, 0 nitrogen fertilizer (BS-F0), and standard nitrogen fertilizer (BS-F1). Nitrogen and organic matter concentrations in soil of BS-F1 plot on October, 2001 were increased 4.8~%~;and~;5.9~% , respectively, compared with those on October, 2000. The ranges of BNF rate in soybean were 69.1~~ 88.2~% in two years, and the rate was the highest in BS-F0 plot and the lowest in SM plot. The ranges of nitrogen harvest index (NHI) in all treatments were 83.9~~86.7~% . The yield was 270 kg/10a in BS­F1 plot and 215 kg/10a in BS-F0 plot. However, the nitrogen balances were +0.6 kg/10a of gain of soil nitrogen in BS-F0 plot and -0.4 kg/10a of loss of soil nitrogen in BS-F1 plot. In comparisons of SM and BS-F1 plots, although the seed yields were similar in two plots, the loss of soil nitrogen was higher in SM than BS-F1 plot. Overall, our results suggest that barley-soybean double cropping system was more effective in respect to seed productivity and soil nitrogen conservation than soybean monocropping system, and the N credit to following crops by soybean cultivation was identified in soybean double cropping system.