• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.157-163
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• 2004

Nitrogen ion implantation and ion plating techniques were applied for improvement of the wear resistance of metallic implant materials. In this work, the wear dissolution behaviour of a nitrogen ion implanted super stainless steel (S.S.S, 22Cr-20Ni-6Mo-0.25N) was compared with those of S.S.S, 316L SS and TiN coated 316L SS. The amounts of Cr and Ni ions worn-out from the specimens were Investigated using an electrothermal atomic absorption spectrometry. Furthermore, the Ti(Grade 2) disks were coated with TiN, ZrN and TiCN by use of low temperature arc vapor deposition and the wear resistance of the coating layers was compared with that of titanium. The chemical compositions of the nitrogen ion implanted and nitride coated layers were examined with a scanting auger electron spectroscopy. It wat observed that the metal ions released from the nitrogen ion implanted S.S.S surface were significantly reduced. From the results obtained, it was shown that the nitrogen ion implanted zone obtained with 100 KeV ion energy was easily removed within 200,000 revolutions from a wear dissolution testing under a similar load condition when applied to artificial hip joint. The remarkable improvement in wear resistance weir confirmed by the nitrides coated Ti materials and the wear properties differ greatly according to the chemical composition of the coating layers. for specimens with the same coating thickness of about 3$\mu\textrm{m}$, TiCN coated Ti showed the highest wear resistance. However, after removing the coating layers, the wear rates of all nitrides coated Ti reverted to their normal rates of below 10,000 revolutions from Ti-disk-on-disk wear testing under the same load condition. From the results obtained, it is suggested that the insufficient depth of the 100 Kel N$\^$＋/ ion implanted zone and of the nitrides coated layers of 3$\mu\textrm{m}$ are subject to restriction when used as frictional parts of load bearing implants.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.307-307
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• 2009

우리나라에서 농가단위 경축순환농업 모델에 대한 조사와 농장내 순환구조에서 양분수지를 조사한 사례도는 미미한 실정이다. 이에 경축연계 자원순환 유기농업농가의 실천사례 발굴하고, 실천모델별 축산형태 및 경종형태를 조사하여 경종부분의 양분순환과 양분수지를 조사하고자 하였다. 발굴된 농가단위 경축순환농업 사례는 3가지 형태로 모두 한우를 11~21두 범위에서 사육하는 동시에 $15,510m^2$의 밭농사를 수행하는 농가, $8,019m^2$의 밭농사와 $8,250m^2$ 논농사를 동시에 수행하는 농가, $26,400m^2$의 논농사만 수행하는 농가들이었다. 각 모델에서 배합사료는 모두 외부에서 구입하고 있었으며 조사료의 자급율은 25 ~ 100%인 것으로 조사되었다. 특히, 한우 20두와 논농사 $26,400m^2$를 경영하는 농가에서 조사료(볏짚)의 100%를 자급하였고 동시에 한우사육과정에서 발생한 자급퇴비를 전량 논농사에 사용하여 유기농 벼농사를 유지하고 있었다. 밭농사를 함께 수행하는 농가에서는 자급퇴비 외에 외부로부터 유박비료 및 발효유기질비료를 구입하여 양분을 충당하고 있었다. 각 농가의 토양이화학성을 분석한 결과 pH는 5.49~7.61, 유기물 함량은 1.37~1.40%, 유효인산 함량 253.32~329.63 mg/kg, 칼륨 0.24~0.3, 칼슘 3.97~10.1, 마그네슘 0.89~1.77 $Cmol^+$/kg, CEC는 7.92~11 $Cmol^+$/kg 이었므며 토양내 잔류농약은 검출되지 않았다. 농가별로 발생한 우분퇴비의 성분 분석결과는 전질소 0.68 ~ 0.73%, 전인산 0.68 ~ 0.86%, 칼륨 0.70~0.78% 수준이었다. 각 사례농가별 투입한 실제시비량, 토양분석결과와 사용된 자재의 성분 분석결과를 이용한 시비처방법에 따른 시비량 및 표준시비법에 따른 시비량을 산출하여 3요소의 양분수지를 계산하였다. 이와 함께 유기질비료의 무기화율을 감안한 시비량도 산출하였다. 양분수지를 분석한 결과 3농가 모두 실제시비량은 3요소 모두 초과 되는 것으로 나타났으며, 특히 인산과 칼륨이 2배정도 초과되는 경향을 보였다. 그러나 투입된 자급퇴비 및 유기질비료의 무기화율을 감안한 시비량으로 환산할 경우에는 질소성분이 3농가 모두 부족한 것으로 산출되었으며, 인산과 가리 성분은 충분하거나 초과되는 것으로 계산되었다. 농장내 축산경영을 통해 발생하는 자급퇴비만을 이용할 경우에 경종부문의 양분수지를 산출한 결과를 보면 실제시비량 기준으로 질소는 56~186%, 인산은 90~346%, 칼륨은41~221%로 양분수지가 달라졌으며, 무기화를 감안한 기준으로는 질소는 16~53%, 인산은 52~197%, 칼륨은 41~221%로 양분수지가 달라졌다. 소규모 유기농가단위 경축연계 자원순환 모델 연구를 통해 유기경종농업이 유지될 수 있으나, 3요소별 양분수지의 불균형이 발생할 수 있는 것으로 조사되었으며, 유기질비료의 특성상 무기화율을 감안한 시비량을 적용할 경우에는 질소 성분의 부족과 동시에 인산, 칼륨 성분의 과다가 예측되었다. 따라서 이러한 성분의 불균형을 조정할 시비체계 연구가 필요한 것으로 판단되었다. 본 연구는 농촌진흥청의 "유기가축사양 및 유기 순환체계모델" 연구사업의 세부과제로 수행한 1년차 결과입니다.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.08a
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• pp.150-151
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• 2005

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.362-370
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• 2013

The coconut shell based activated carbon was applied for EDLC (electric double layer capacitor) electrode with the post treatments. The electrochemical properties were evaluated with a coin cell using the activated carbon as electrode. The initial gravimetric and volumetric capacitance of the coconut shell based activated carbon electrode s were 66 F/g and 39 F/cc, and these values decreased to 54 F/g and 32 F/cc after 100 cycles, respectively showing 82% of charge-discharge efficiency. The properties of CV graph with the commercial activated carbon electrodes showed the serious polarization as the result of additional reaction between electrolyte and impurities of the electrode materials. In order to remove impurities efficiently, the commercial activated carbon was treated by alkali and acid solutions consecutively, and then heat treated to control the pore size distribution and the content of surface functional groups. The surface functional groups decreased with the increased heat temperature and the specific capacitance increased with the decreased surface functional groups. The initial capacitance of coconut shell based activated carbon elec trode which was treated with NaOH and HNO3, and then heat treated at $800^{\circ}C$ was 44 F/cc, and the value turned out to be 42 F/cc after 100 cycles, showing over 95% of charge-discharge efficiency.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.384-392
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• 2022

The objective of this study was to estimated nitrogen content and chlorophyll using RGB, Hyperspectral sensors to diagnose of nitrogen nutrition in apple tree leaves. Spectral data were acquired through image processing after shooting with high resolution RGB and hyperspectral sensor for two-year-old 'Hongro/M.9' apple. Growth data measured chlorophyll and leaf nitrogen content (LNC) immediately after shooting. The growth model was developed by using regression analysis (simple, multi, partial least squared) with growth data (chlorophyll, LNC) and spectral data (SPAD meter, color vegetation index, wavelength). As a result, chlorophyll and LNC showed a statistically significant difference according to nitrogen fertilizer level regardless of date. Leaf color became pale as the nutrients in the leaf were transferred to the fruit as over time. RGB sensor showed a statistically significant difference at the red wavelength regardless of the date. Also hyperspectral sensor showed a spectral difference depend on nitrogen fertilizer level for non-visible wavelength than visible wavelength at June 10th and July 14th. The estimation model performance of chlorophyll, LNC showed Partial least squared regression using hyperspectral data better than Simple and multiple linear regression using RGB data (Chlorophyll R²: 81%, LNC: 81%). The reason is that hyperspectral sensor has a narrow Full Half at Width Maximum (FWHM) and broad wavelength range (400-1,000 nm), so it is thought that the spectral analysis of crop was possible due to stress cause by nitrogen deficiency. In future study, it is thought that it will contribute to development of high quality and stable fruit production technology by diagnosis model of physiology and pest for all growth stage of tree using hyperspectral imagery.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.1
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• pp.38-46
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• 2002

Chrysanthemum boreale M. (hereafter, C. boreale M.), a perennial flower, has been historically used as a natural medicine in Korea. With increasing concerns for health-improving foods, the demand for C. boreale M. has become higher than ever. Howevr, the amount of wild C. boreale M. collected from mountainous areas is not enough to cover all demands. The cultivation system and fertilization strategy are required to meet increasing demand on C. boreale M. with a good quality. We investigated the effects of nitrogen application on plant growth and effective components of C. boreale M. to suggest optimum rate of nitrogen fertilization. C. boreale M. was cultivated in a pot scale (1/2000a scale), and nitrogen applied with rate of 0(N0), 50(N50), 100(N100), 150(N150), 200(N200), and $250(N250)kg\;ha^{-1}$. Phosphate and potassium were applied at the same level ($P_2O_5-K_2O=80-80kg\;ha^{-1}$) in all treatments. Maximum yield achieved in 246 and $226kg\;ha^{-1}$ N treatment on the whole plant and the flower part, a valuable part as a herbal medicine, respectively. Proline was the most abundant amino acid in the flower of C boreal M. and the contents of amino acids increased with increasing nitrogen application rate in flower. Nitrogen recovery efficiency was high more than 41% in all nitrogen treatments and increased to 61.8% in nitrogen N100 treatment. From the nitrogen content, the high nitrogen uptake, the low residue of mineral N and the reasonably good apparent fertilizer recovery, it can be inferred that C. boreale M. made efficient use of the available nitrogen. In flower, contents of Cumambrin A. which is a sesquiterpene compound and has the effect of blood-pressure reduction, decreased with increasing nitrogen application. However, the amount of Cumambrin A in flower increased as nitrogen rate increased, because of increasing flower yield. Conclusively, nitrogen fertilization could increase yields and enhance quality. The optimum nitrogen application rate might be on the range of $225{\sim}250kg\;ha^{-1}$ in a mountainous soil.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.310-311
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• 2009

농업현장에서 활용되는 농업용미생물의 효능을 평가하고 현장실용화를 제고할 목적으로 본 시험을 수행하였다. 8개 지자체를 대상으로 친환경농업 특성화 지원사업 현황을 조사하고, 지자체별 미생물 활용수준을 평가하였으며, 각 지자체별로 활용되는 미생물을 수집하여 항균활성, siderophore 생성, IAA 생성, 질소고정, 인산가용화 능력 및 작물생육에 미치는 영향을 분석하였다. 지자체에서 활용하는 미생물은 주로 유산균, 고초균, Bacillus속 세균, 광합성균, 효모 및 EM 등으로 몇가지 종류의 미생물을 활요하는 것으로 조사되었고, 배양을 위한 배지는 대부분 균주를 개발한 대학 또는 산업체에서 공급받는 것으로 나타났으며, 배양기술 측면에서 볼 때 단순 배양 보급하는 지자체가 2개소, 산-학-연간 공급네트워크 및 대량배양체계를 구축하여 미생물을 활용하는 지자체가 7개소, 미생물 대량배양체계를 구축하고 병해충 관리연구를 수행하는 지자체가 1개소 그리고 미생물 선발, 특성검정 및 효과 평가 등 개발 및 응용을 추진하는 지자체가 1개소인 것으로 나타나 지자체에 따라 활용기술 수준은 큰 차이를 보였다. 지자체 공급 농업미생물의 항균활성을 조사한 결과, 고초균, 효모, 유산균, 광합성균, Bacillus속 세균 모두에서 균주에 따라 항균활성을 보였는데, 특히 Bacillus 속 세균이 높은 빈도로 황균활성을 보이는 것으로 나타났다. 철 킬레이트 능력 (Siderophore 형성능)에 있어서는 5개 광합성 균주 중 1균주가, 5종의 효모 중 1균주만이 활성을 보인 반면, Bacillus속 세균(고초균 포함)의 경우에는 11개 균주 모두 활성을 보였다. 작물 생육과 밀접한 관계가 있는 IAA(Indole acetic acid)의 생성능에 있어서는 광합성균이 5균주 중 4균주가 활성을 보여 비교적 생성능이 높은 것으로 나타났으며, Bacillus 속 세균의 경우에는 11균주 중 8개 균주가 활성을 보여 광합성균 다음으로 높은 반도를 나타냈다. 효모의 경우에는 5균주 중 1개 균주가 IAA를 생성하는 것으로 나타났다. 질소고정능에 있어서는 광합성균은 5균주 중 3균주, Bacillus 속세균 11균주 중 6균주가, 효모는 5균중 1균주가 활성을 보인 반면, 유산균 중에는 단 한 균주도 질소 고정능을 보이지 않았다. 연작재배에 따라 토양 내에 축적되는 인산의 가용화능을 분석한 결과, 수집한 대부분의 유산균은 높은 활성을 보인 반면 기타 미생물은 인산가용화능이 거의 없는 것으로 나타났다. 결론적으로 Bacillus 속 세균은 항균활성이 높고, 작물생육과 밀접한 IAA 생성 및 질소고정능력을 보유 하고 있는 것으로 나타나 친환경 작물재배시 병 발생을 줄이고 작물생장을 촉진할 수 있는 미생물로 평가되었다. 농업현장에서 기능성 및 효능을 고려하여 미생물을 잘 활용하면 병 발생 관리 및 생산성 향상에 도움이 되리라 판단된다.

• Korean Journal of Organic Agriculture
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• v.24 no.3
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• pp.557-570
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• 2016

Growth of 6-year old 'Niitaka' pear (Pyrus pyrifolia Nakai) trees and control of insect and disease occurrences were compared between fermented soybean extracts and rain-shelter system for two years. Foliar application of fermented soybean extracts was applied at 6 times as a pre-experiment in the open-field in 2013, with a rain-shelter system in 2014. Fermented soybean extract treatment increased foliar concentrations of approximately 0.46% T-N, 0.17% K, 0.19% Ca, and 0.06% Mg in 2013 compared to the control, with similar macro-nutrients between the control and soybean extract treatment observed in 2014. Rain-shelter system increased foliar concentrations of T-N, Ca, and Mg compared to the open-field. There were no significantly different between the control and soybean extract treatment for number of leaves per fruit, leaf dry weight, phytotoxicity, and completed shoot growth on August during the two years. Rain-shelter system increased leaf dry weight and did not affect phytotoxicity in the leaves. Fruit quality parameters were mostly similar to control and soybean extract treatment for two years, with higher fruit firmness observed for soybean extract treatment. Rain-shelter system advanced 4 days of harvest dates, and increased approximately 7.0 ton fruit yield per ha, 20 g mean fruit weight, and fruit soluble solid contents compared to open-field in 2014. Soybean extract treatment little suppressed occurrence of disease and insect on the leaves and fruits in both years. Rain-shelter system increased occurrence of Venturia nashicola on the leaves and to 63.8% of Gymnosporangium asiaticum on the fruits in 2014. Strong winds and storms in May elevated relative humidity in the rain-shelter system and caused high infection of the disease occurrence, requiring for an additional green control method. Soybean extract treatment little affected tree growth and would have initiated for a long-term study to evaluate tree physiological characteristics. Rain-shelter system improved fruit productivity and advanced harvest dates, which could have been more effective facility at a Thanks Giving Day between middle and end of September.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.408-419
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• 2006

A pot experiment was conducted for two years to evaluate the effects of purified Si fertilization combined with $^{15}N$ on the nutrient uptake, plant growth characteristics, and photosynthetic characteristics of rice in water melon cultivated soil. In 2002, plant height was positively affected at 25 DAT (Day After Transplanting) by Si fertilization in 100%N treatment. However, in 2003, plant height at 25 DAT was negatively affected by Si fertilization in low N level but it was reversed in high N level with initial increase of plant height. Tiller number per pot was positively affected by N and Si fertilization level, especially for high N fertilized treatment. Leaf color was positively affected by Si fertilizatlon in no N fertilized pots, however, Si was not effected in 50%N and 100%N fertilized treatments. N harvest index (NHI) increased with increased Si fertilization in no N plots, however it decreased with increasing of N fertilization level. Nitrogen use efficiency (NUE) decreased with increasing of fertilized N but Si fertilization increased NUE in 50%N plots, however, it was not different by the Si fertilization level in 100%N plots. In 50%N+200%Si plots, NUE was greatest with 130 and shoot N content was $16.2g-N/m^{2}$. N content ($g/m^{2}$) in rice plant increased with increasing Si fertilization in no N plots at panicle initiation stage, 50 and 100%N plots at heading stage and all N treatment at harvesting time. This was mostly more efficient in late growth stage than early growth stage. The concentration (%) of P and K increased with increasing N fertilization level at heading and harvesting but it was not significantly different by the Si fertilization treatment except a little decreasing with increasing Si fertilization level at heading. Potassium content was also not significantly related with N fertilization level except increasing with Si fertilization level at panicle initiation stage. Plant Ca content (%) decreased with increasing of Si fertilization at heading stage and Si fertilization increased Ca content at panicle initiation stage and heading stage and it increased with increasing of Si fertilization level. Photosynthetic activity was not directly related with Si fertilization amount, however, Fluorescent factors, Fv'/Fm' and PsII, were positively affected by Si fertilization level. In conclusion, N fertilization in Si 200% fertilized condition should be reduced by about 50% level of recommended N fertilization for rice cropping in green-house water-melon cultivated paddy field. However, improvement of Ps by Si fertilization could not be attributed to Ps activity in the same leaf area but because of increased total leaf area per pot improved fluorescent characteristics.

• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.151-153
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• 1992

We have successfully cryopreserved free-living amoebae in order to maintain them feasibly under the conditions in our laboratory. The viability of trophozoites was higher when frozen by slow cooling (overall $0.7^{\circ}C$/min) than by fast cooling (overall $1.3^{\circ}C$/min). Glycerol and dimethylsulfoxide at the final concentration of 7.5% each was used for cryopreservation of free-living amoebae trophosoites. The survival rate was 2∼39% after storage in the liquid nitrogen for 60 days. Gross cultural or morphological changes were not noted in trophozoites thawed from frozen suspensions.