• Journal of Magnetics
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• 제13권4호
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• pp.149-152
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• 2008

In this report, we present the results of a study on the effects of the particle size on the properties of the Prussian blue (PB) analog $Na_xMn_y[Fe(CN){_6}]$. A novel synthesis method of the $Na_xMn_y[Fe(CN){_6}]$ nano-particles using an organic solvent, formamide, is employed. The size of the PB particles is found to be 100-150 nm for the samples prepared in the formamide solvent, which is much smaller than that of the samples prepared using water only. The broadening of the X-ray diffraction peaks of the nano-sized PB samples is attributed to the lattice disorder and a dramatic reduction in the particle size. The compositions of the samples are confirmed by an energy-dispersive X-ray analysis (EDAX), and the result proves that the samples are actually $Na_xMn_y[Fe(CN){_6}]$ Prussian blue. The UV-vis spectra show a broad intervalence charge-transfer (CT) band in the visible region between 400 and 700 nm, and the absorption decreases abruptly in the green region for the nano-sized PB sample. A divergence between the field cooled (FC) and zero field cooled (ZFC) magnetization curves is observed for the nano-sized PB sample at 11 K, indicating that nanoparticles in the sample are single domain superparamagnets with a blocking temperature of 11 K. Our results reveal that the nano-sized PB samples show significantly different optical and magnetic properties than those of the bulk PB samples.

• 식물병연구
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• 제10권4호
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• pp.231-240
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• 2004

2002년 노지 및 시설재배 고추를 대상으로 전국적인 규모의 바이러스병 발생실태를 조사하였다. 시설(155시료) 및 노지포장(227시료)에서 바이러스 감염주를 채집하여 전자현미경과 RT-PCR로 분석하였다. 시설 및 노지재배 고추에서 수집한 시료에서 TMV, RMV, PVY, AMV, TSWV에 감염된 것은 없었다. 그러나 CMV, BBWV, PepMoV, PMMoV, ToMV, TMGMV는 RT-PCR에 의해 검출되었다. 시설 및 노지재배 포장에서 바이러스 발병율은 상당히 다르게 나타났다. 시설재배에서는 10%의 발병율을 보였으나, 노지재배에서는 약 30%의 발병율을 나타냈다. 복합감염율은 시설 및 노지재배에서 각각 16%와 61%로 나타났다. 시설재배에서는 PMMoV가 우점하는 것으로 보아, 바이러스에 오염된 종자와 재배지에서의 바이러스 감염잔재물이 중요한 전염원이 된 것으로 보인다. 반대로 노지재배에서는 CMV와 BBWV가 우점하였다. 이것으로 보아 바이러스를 보독한 매개충의 이동이 가장 중요한 전염원으로 나타났다. 또한 이 연구에서 BBWV2는 우리나라에서 방제해야 할 새로운 바이러스로 대두되었다. 노지 및 시설재배에서 바이러스병의 발병율과 분포의 차이로 볼 때 연작에 따른 전염원의 축적 및 분포상과 재배지로의 바이러스 보독매개충의 이동이 바이러스 발생을 결정하는 중요한 요소로 보인다. 그러므로 식물병 역학과 고추의 새로운 육종 프로그램에 대한 진전된 연구가 바이러스 병을 줄이는데 필수적일 것이다.

• Applied Biological Chemistry
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• 제3권
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• pp.17-18
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• 1962

A study on fungus flora of 8 paddy field soil samples including 5 AKIOCHI soils has been made. Samples were taken from Chung-nam area. Fungi of 5 Genera and 19 species were identified; Aspergillus, Penicillium, Spicaria, Curvularia, Trichodema, were the 5 genera and the 19 speciec consristed of 4 Aspergilli, 12 Penicilli, and the each one of the others. Variations of fungus flora among those soil samples were noticed without the ecologieal explanation.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권4호
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• pp.153-158
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• 2003

This thesis deal with ferroelectric and ferromagnetic materials. PZT/Ferrite ceramics were made by the making process using PZT powder and garnet ferrite powder. PZT and ferrite are mixed as much 90%-10%, 50%-50%, and so on. After making samples, we are polishing samples until thickness is 0.1~0.2mm. We measured all kinds of samples in room temperature and applied magnetic field from -4500 to 4500 Oersted and conducted test of magnetical and electrical measurement using VSM and lpC resolution electrometer calibrated with RT66A pulsed tester. From this measurement, we can calculate tunability of these samples using C value obtained from P-E loop. As a result, it was able to measure magnetic characteristic when two matter had each other component ratio, and it was compound. However, it confirmed the possibility that was able to have ferroelectric characteristic with you in PZT 90% and ferrite 10%. Therefore, If this thing comes for PZT 50% and ferrite 50% have ferroelectric characteristic as him in a compound sample ore, can use this in an oscillator, supersonic waves detector in addition to a piezoelectric element. It may contribute to multipurpose of an element and demands such as a miniaturization of equipment, efficiency, reduce of a price which can use a characteristic of two components.

• Environmental Engineering Research
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• 제10권3호
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• pp.112-121
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• 2005

The effectiveness of quicklime-based stabilization/solidification (S/S) in immobilizing lead (Pb) was assessed by performing semi-dynamic leaching tests (ANS16.1). In order to simulate landfill leaching conditions, the ANS 16.1 test was modified by using 0.014 N acetic acid (pH = 3.25) instead of distilled water. Artificial soil samples as well as field soil samples contaminated with Pb were tested. The effectiveness of quicklime treatment was evaluated by determining diffusion coefficients ($D_e$) and leachability indices (LX). A model developed by de Groot and van der Sloat was used to elucidate the controlling Pb leaching mechanisms. Overall, upon quicklime treatment Pb leachability was significantly reduced in a]l of the samples tested. The mean LX values were higher than 9 for an artificial soil sample containing 30% kaolinite treated with 10% quicklime and for a field soil sample treated with 10% quicklime, which suggests that S/S treated soils can be considered acceptable for "controlled utilization". Moreover, quicklime treatment was more effective in artificially contaminated soil with high kaolinite content (30%), indicating the amount of clay plays an important role in the success of the treatment. The controlling Pb leaching mechanism was found to be diffusion, in all quicklime treated samples.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1996년도 The 9th KACG Technical Annual Meeting and the 3rd Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.522-522
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• 1996

An investigation of the effects of transverse magnetic field and Peltier effect on melt convection and macrosegregation in vertical Bridgman crystal grosth of Te doped InSb was been carried out by means of microstructure observation, Hall measurement, electrical resistivity measurement and X-ray analysis. Before the experiments, Interface stability, convective instability and suppression of convection by magnetic field were calculated theoretically. After doping 1018, 1019 cm-3 Te in InSb, the temperature of Bridgman furnace was set up at $650^{\circ}C$. The samples were grown in I.D. 11mm, 100mm high quartz tube. The velocity of growth was about 2${\mu}{\textrm}{m}$/sec. In order to obtain the suppression of convection by magnetic field in the middle of growth, 2-4KG magnetic field was set on the melt. For searching of the shape of solid-liquid interface and the actual velocity of crystal growth, let 2A current flow from solid to liquid for 1second every 50seconds repeatedly (Peltier effect). The grown InSb was polycrystal, and each grain was very sharp. There was no much difference between the sample with and without magnetic field at a point of view of microstructure. For the sample with Peltier effect, the Peltier marks(striation) were observed regularly as expected. Through these marks, it was found that the solid-liquid interface was flat and the actual growth velocity was about 1-2${\mu}{\textrm}{m}$/sec. On the ground of theoretical calculation, there is thermosolutal convection in the Te doped InSb melt without magnetic field in this growth condition. and if there is more than 1KG magnetic field, the convection is suppressed. Through this experiments, the effective distribution coefficients, koff, were 0.35 in the case of no magnetic field, and 0.45 when the magnetic field is 2KG, 0.7 at 4KG. It was found that the more magnetic field was applied, the more convection was suppressed. But there was some difference between the theoretical calculation and the experiment, the cause of the difference was thought due to the use of some approximated values in theoretical calculation. In addition to these results, the sample with Peltier effect showed unexpected result about the Te distribution in InSb. It looked like no convection and no macrosegregation. It was thought that the unexpected behavior was due to Peltier mark. that is, when the strong current flew the growing sample, the mark was formed by catching Te. As a result of the phenomena, the more Te containing thin layer was made. The layer ruled the Hall measurement. The values of resistivity and mobility of these samples were just a little than those of other reference. It was thought that the reason of this result was that these samples were due to polycrystal, that is, grain boundaries had an influence on this result.

• Journal of the Korean Data and Information Science Society
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• 제9권1호
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• pp.57-62
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• 1998

The minimum number of samples for the measurement of plant characteristics of major crops were calculated from the data obtained from the field experiments on rice, barley, wheat, soybean and sweet potato conducted by Kyungpuk Rural Development Administration.

• Journal of Biosystems Engineering
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• 제36권2호
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• pp.96-108
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• 2011

Several methods of in-field measurements of Nitrogen and other soil properties using cores extracted by a hydraulic soil sampler were evaluated. A prototype core scanner was built to accommodate Veris Technologies commercial Vis-NIRS equipment. The testing result for pH, P and Mg were close to RPD (Ratio of Prediction to Deviation = Standard deviation/RMSE) of 2, however the scanner could not achieve the goal of RPD of 2 on some other properties, especially on nitrate nitrogen ($NO_3$) and potassium (K). In situ NIRS/EC probe showed similar results to the core scanner; pH, P and Mg were close to RPD of 2, while $NO_3$ and K were RPD of 1.5 and 1.2, respectively. Correlations between estimations using the probe and the core scanner were strong, with $r^2$ > 0.7 for P, Mg, Total N, Total C and CEC. Preliminary results for mid-IR spectroscopy showed an $r^2$ of 0.068 and an RMSE for nitrate (N) of 18 ppm, even after the removal of calcareous samples and possible N outlier. After removal of calcareous samples on a larger sample set, results improved considerably with an $r^2$ of 0.64 and RMSE of 6 ppm. However, this was only possible after carbonate samples were detected and eliminated, which would not be feasible under in-field measurements. Testing of $NO_3$ and K ion-selective electrodes (ISEs) revealed promising results, with acceptable errors measuring soil solutions containing nitrate and potassium levels that are typical of production agriculture fields.

• 환경영향평가
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• 제22권2호
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• pp.135-145
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• 2013

The recycling of coal bottom ash generated from coal power plants in Korea has been limited due to heterogenous characteristics of the materials. The most common management option for the ash is disposal in landfills (i.e. ash pond) near ocean. The presence of large coarse and fine materials in the ash has prompted the desire to beneficially use it in an application such as fill materials. Prior to reuse application as fill materials, the potential risks to the environment must be assessed with regard to the impacts. In this study, a total of nine test cells with bottom ash samples collected from pretreated bottom ash piles and coal ash pond in a coal-fired power plant were constructed and operated under the field conditions to evaluate the leachability over a period of 210 days. Leachate samples from the test cells were analyzed for a number of chemical parameters (e.g., pH, salinity, electrical conductance, anions, and metals). The concentrations of chemicals detected in the leachate were compared to appropriate standards (drinking water standard) with dilution attenuation factor, if possible, to assess potential leaching risks to the surrounding area. Based on the leachate analysis, most of the samples showed slightly high pH values for the coal ash contained test cells, and contained several ions such as sodium, potassium, calcium, magnesium, chloride, sulfate, and nitrate in relatively large quantities. Three elements (aluminum, boron, and barium) were commonly detected above their respective detection limits in a number of leachate samples, especially in the early leaching period of time. The results of the test cell study indicate that the pollutants in the leachate from the coal ash test cells were not of a major concern in terms of leaching risk to surface water and groundwater under field conditions as fill materials. However, care must be taken in extending these results to actual applications because the results presented in this study are based on the limited field test settings and time frame. Structural characteristics and analysis for coal bottom ash may be warranted to apply the materials to actual field conditions.

• Pediatric Infection and Vaccine
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• 제19권3호
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• pp.149-156
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• 2012

목 적 : 소아청소년을 대상으로 2010-2011 인플루엔자 백신의 야외 효능을 확인하고자 하였다. 방 법 : 2010년 9월에서 2011년 2월까지 소아 청소년을 대상으로 서울 경기지역의 7개 병원과 1개 초등학교에서 인플루엔자 백신을 접종한 시험군과 접종하지 않은 대조군을 모집하였다. 급성 발열성 호흡기 질환 증상이 있을시 임상시험기관에 방문하도록 하여 검체를 채취하여 감염여부를 확인하였다. 결 과 : 시험 군 407명 중 3명(0.74%)에서 3건의 신종 H1N1 인플루엔자 바이러스가 검출되었고, 대조군 230명 중 10명(4.35%)에서 12건을 검출하여 9명(3.91%)에서 9건의 신종 H1N1, 3명(1.30%)에서 3건의 H3N2 인플루엔자 바이러스를 검출하였다. 시험군에서의 인플루엔자 발생률은 0.74%, 대조군에서 4.35%였다. 백신의 야외 효능은 83.2%였다. 결 론 : 소아청소년을 대상으로 2010-2011년 인플루엔자 백신의 야외효능은 우수하였음을 확인하였다.