• Korean Journal of Soil Science and Fertilizer
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• v.8 no.1
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• pp.31-35
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• 1975

In order to gain information on the plant characteristics of high yielding paddy from the point of view of mineral nutrition and to learn more about soil conditions under which high yields are produced a number of soil samples collected from the field experiment carried out in The City College of Seoul were analysed. In addition, a laboratory experiment carried out to support the field experiment was also analysed. Results obtained are as follows: 1. Generally, the higher the yield of paddy, the higher is the potassium content in flag leaves, whereas the reverse is true for the content of Ca and Mg in the leaves. From these facts it can conceivably be said that the high yielding paddy should absorb a large quantity of potassium and a lesser quantity of calcium and magnesium in the reproductive stage. 2. Leaves of paddy which produced yields over 600kg/10a (a comparatively high yield in the experiment) contained 30-35mg/100g of potassium, less than 25me/100g of calcium, and 10me/100g of magnesium which brings the ratio of $K/{\sqrt{Ca+Mg}}$ over 5. 3. Correlation studies indicated a remarkable relationship between the paddy yield and exchangeable potassium in soil samples taken after harvesting. A similar relationship was observed between the yield of paddy and $K/{\sqrt{Cae+Mge}}$ ratio of the soil samples. 4. A regression between yield of padcy (Y) and exchangeable potassium (Ke) or $K/{\sqrt{Ca+Mg}}$ in soil samples taken after harvesting was shown to be; Y=183.95+2135.86Ke $$Y=352.45+3114.454\;K/{\sqrt{Ca+Mg}}$$ 5. The regression between exchangeable potassium (Ke) in soil samples taken after harvesting and the amount of lime (L) and potassium (P) to be applied is; $$Ke=0.1246+0.00007037L+0.004444P+0.000004444L{\cdot}P$$.

• Journal of fish pathology
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• v.23 no.2
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• pp.199-209
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• 2010

This study was aimed to investigate the effects in different immersion doses of garlic, Allium sativum, juice to modulate on the nonspecific immune responses of the olive flounder, Paralichthys olivaceus, artificially prechallenged with Streptococcus iniae BS10 and Edwardsiella tarda KE-1, respectively. The nonspecific immune responses of the tested fish were assessed in term of skin mucus lysozyme activity, the change of bacterial cell counts in organs, the number of lymphocytes and neutrophils in blood, and SOD activity. Almost groups of the prechallenged with either S. iniae BS10 or E. tarda KE-1 fish which had been immersed in garlic juice showed the enhanced skin mucus lysozyme activity, the number of lymphocytes and neutrophils in blood, and SOD activity in the kidney but the decreased the number of bacterial cell in surveyed organs. RPS in the group immersed in 0.25 g/L of garlic juice was much higher than in other immersed test groups. These results suggested that the garlic juice immersion can be effective on enhancement of the nonspecific immune responses and the protective ability of olive flounder to the artificial challenge with S. iniae BS10 and E. tarda KE-1.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.34-37
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• 2017

In recent emerging industry, Display field becomes bigger and bigger, and also semiconductor technology becomes high density integration. In Flat Panel Display, there is an issue that electrostatic phenomenon results in fine dust adsorption as electrostatic capacity increases due to bigger size. Destruction of high integrated circuit and pattern deterioration occur in semiconductor and this causes the problem of weakening of thermal resistance. In order to solve this sort of electrostatic failure in this process, Soft X-ray ionizer is mainly used. Soft X-ray Ionizer does not only generate electrical noise and minute particle but also is efficient to remove electrostatic as it has a wide range of ionization. X-ray Generating efficiency has an effect on soft X-ray Ionizer affects neutralizing performance. There exist variable factors such as type of anode, thickness, tube voltage etc., and it takes a lot of time and financial resource to find optimal performance by manufacturing with actual X-ray tube source. MCNPX (Monte Carlo N-Particle Extended) is used for simulation to solve this kind of problem, and optimum efficiency of X-ray generation is anticipated. In this study, X-ray generation efficiency was measured according to target material thickness using MCNPX under the conditions that tube voltage is 5 keV, 10 keV, 15 keV and the target Material is Tungsten(W), Gold(Au), Silver(Ag). At the result, Gold(Au) shows optimum efficiency. In Tube voltage 5 keV, optimal target thickness is $0.05{\mu}m$ and Largest energy of Light flux appears $2.22{\times}10^8$ x-ray flux. In Tube voltage 10 keV, optimal target Thickness is $0.18{\mu}m$ and Largest energy of Light flux appears $1.97{\times}10^9$ x-ray flux. In Tube voltage 15 keV, optimal target Thickness is $0.29{\mu}m$ and Largest energy of Light flux appears $4.59{\times}10^9$ x-ray flux.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.2
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• pp.97-105
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• 2014

In the case of the direct measurement of $^{226}Ra$ using a HPGe gamma-ray spectrometer, the interference between gammarays with 186.21 keV of $^{226}Ra$ and 185.7 keV of $^{235}U$ should be corrected to calculate the net peak area in the energy spectrum. In general, it is very difficult to conduct peaks stripping with difference of about 0.5 keV, although a HPGe with the superior resolution is applied and the maximum channels is applied to the spectrometer. In this study, several interference correction techniques in the direct measurement were surveyed to evaluate the feasibility for the measurement of $^{226}Ra$ using the gamma-ray spectrometery. Applying the interference corrections to the analysis of raw materials and by-products, the method validation for the direct measurement of $^{226}Ra$ was conducted by evaluating the measurement uncertainty, linearity, and range. As a result, the optimum method of the interference correction was selected by comparing with the indirect measurement of which progenies of $^{226}Ra$, such as $^{214}Pb$ and $^{214}Bi$, were analyzed in the secular equilibrium state.

• Journal of Radiation Protection and Research
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• v.40 no.2
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• pp.110-117
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• 2015

Recently, Due to the increased industry using radiation inspection equipment in the semiconductor, this demand of technology research is increasing. Although semiconductor inspection equipment is using low energy X-ray from 40 keV to 120 keV, Studies of radiation damage about the low energy X-ray are lacking circumstance in our country. Therefore, It is study that BJT (bipolar junction transistor) of one type of semiconductor elements are received radiation damage by low energy X-ray. BJT were used to the NXP semiconductor company's BC817-25 (NPN type), and Used the X-ray generator for the irradiation. Radiation damage of BJT was evaluated that confirm to analyse change of collector-emitter voltage of before and after X-ray irradiation when current gain fixed to 10. X-ray generator of tube voltage was setting 40 kVp, 60 kVp, 80 kVp, 100 kVp, 120 kVp and irradiation time was setting 180s, 360s, 540s into 180s intervals. As the result, We confirmed radiation damage in BJT by low energy X-ray under 120 keV energy, and Especially the biggest radiation damage was appeared at the 80 kVp. It is expected that ELDRS (enhanced low dose rate sensitivity) phenomenon occurs on the basis of 80 kVp. This studies expect to contribute effective dose administration of semiconductor inspection equipment using low energy X-ray, Also Research and Development of X-ray filter.

• Nuclear Engineering and Technology
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• v.11 no.2
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• pp.133-136
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• 1979

In the paper it is proposed to use Ge(Li) detectors in determining fast neutron spectra. The spectrum at 691.4 KeV which is produced by the internal conversion of Ge nuclei being broadened by the coincident ionization energy deposited by recoil Ge atoms is proposed to be analysed in estimating the fast neutron spectra.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.415-418
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• 1999

It is expected that industrial accelerator having been distributed fast in domestic these days will be widely used for various fields. In this study we deal with the basic consideration for the drive characteristic of power supply system in the system of industrial accelerator installed at Dongshin University. Beam energy of this system is 34keV~40KeV, 100A. The modulator emits a 11KV-380A pulse of $4.5\mu\textrm{s}$ duration that is transformed to about 34KV-40KV pulse by a pulse transformer.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.41-42
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• 1996

A possible cosmic X-ray background(XRB) radiation related to original antimatter is considered. If the universe is made of separating domains of antimatter and matter, the photons produced by the annihilation of electron-positron and proton-antiproton on the last scattering surface would reach us in the energy $\~$0.45 keV and $\~$60 keV respectively because of the redshift. The spectrums of X-ray radiation from annihilation are deduced and a possible observational figure is described also.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.1
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• pp.23-27
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• 2005

We observed that optical properties of silicon changed under high dose electron irradiation at 250 keV. Our experimental results revealed that the optical transmission through a silicon wafer is significantly increased by electron irradiation. Transmission increase by the change in the absorption coefficient is explained through an analogy with amorphous silicon. Moreover, solar cell open-circuit voltages indicated that defects were generated by electron irradiation, and that the defects responded to annealing. Our results demonstrated that the optical properties of silicon can be controlled by a combination of electron irradiation and hydrogen annealing.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.425-426
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• 2017

본 논문은 미래 녹색에너지원으로 주목받는 핵융합에너지 개발 장치인 한국형 초전도 핵융합 연구로(KSTAR : Korea Superconducting Tokamak Advanced Research)의 가열장치인 중성입자빔(NBI : Neutral Beam Injector) 장치를 소개하고, 2016년 KSTAR 실험에서 빔 에너지 90/70/80 keV, 빔 출력 3.81 MW, 70.6초의 최대 장 펄스와 빔 에너지 95/90/90 keV, 빔 출력 5.13 MW, 10.6 초로 입사 운전한 NBI 장치 실험 결과를 정리한다.