• 생태와환경
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• 제34권2호통권94호
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• pp.106-118
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• 2001

대청호내 3개 지점에서 저토의 영양염을 조사하여 수층과 식물플랑크톤에 대한 생장 잠재력에 미치는 영향을 파악하였다. 저토-수층의 경계면에서 DO는 0.5 mg $O_{2}$/l 이하로서 무산소 상태였다. 공극수의 전기전도도는 저토보다 1.9${\sim}$2.6배 더 높았고 수심이 얕을수록 변동폭이 컸다. Eh는 -12${\sim}$-148mV 범위였고 가비중은 1.17${\sim}$1.30g/cm$^{3}$ 범위로서 지역간에 차이가 크지 않았다. 함수율과 유기물 함량은 각각 58%${\sim}$72%, 8${\sim}$13% 범위로서 댐 부근에서 높았고 옥천천에서 낮았다. 저토의 입도 조성은 사질이 97%를 차지하였다. 저토내 총세균수와 규조류의 세포밀도는 수심이 깊은 하류에서 높았다. 공극수와 치환성의 질소와 인 함량에서 입자성이 용존성보다 풍부하였고, 무기 질소로는 NH$_{4}$가 대부분이었다. 또한 유기와 무기 질소 형태로 볼 때, 공극수내 질소함량은 무기 질소가 많았고, 치환성 질소는 유기 질소가 많았다. 공극수 인 함량에서 용존 유기 인이 많았고 치환성은 무기 인이 많았다. 저토내 규소는 치환성이 최대 63%로서 공극수보다 훨씬 많았다. 대청호의 저토는 유기물이 풍부한 부영양 상태로 평가되었다.

• 한국토양비료학회지
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• 제48권5호
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• pp.456-463
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• 2015

The objective of this study was to determine the effects of granular type of silicate fertilizer on watermelon growth, yield, and characteristics of soil in the greenhouse. Four different levels of silicate fertilizer, 0(control), 600, 1,200, $1,800kg\;ha^{-1}$ were applied for experiment. The silicate fertilizer was applied as a basal fertilization before transplanting watermelon. Compost and basal fertilizers were applied based on the standard fertilizer recommendation rate with soil testing. All of the recommended $P_2O_5$ and 50% of N and $K_2O$ were applied as a basal fertilization. The N and $K_2O$ as additional fertilization was split-applied twice by fertigation method. Watermelon (Citrullus lanatus Thunb.) cultivar was 'Sam-Bok-KKuol and main stem was from rootstock (bottle gourd: Lagenaria leucantha Standl.) 'Bul-Ro-Jang-Sang'. The watermelon was transplanted on April, 15. Soil chemical properties, such as soil pH, EC, available phosphate and exchangeable K, Mg, and available $SiO_2$ levels increased compared to the control, while EC was similar and the concentrations of soil organic matter decreased. Physical properties of soils, such as soil bulk density and porosity were not different among treatments. The growth characteristics of watermelon, such as stem diameter, fresh and dry weight of watermelon at harvest were thicker and heavier for silicate treatment than the control, while number of node was shorter than the control. Merchantable watermelon increased by 3-5% compared to the control and sugar content was 0.4 to $0.7^{\circ}Brix$ higher than the control. These results suggest that silicate fertilizer application in the greenhouse can improve some chemical properties of soils and watermelon stem diameter and dry weight, which are contributed to watermelon quality and marketable watermelon production.

• Journal of Ginseng Research
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• 제37권3호
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• pp.315-323
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• 2013

Ginseng is known to have antistress effects. Previously, red ginseng (RG) was shown to repress stress-induced peptidyl arginine deiminase type IV (PADI4) via estrogen receptor ${\beta}$ ($ER{\beta}$) in the brain, thus inhibiting brain cell apoptosis. Moreover, tumor necrosis factor (TNF)-${\alpha}$ plays a critical role in immobilization (IMO) stress. However, the signaling pathway of RG-mediated repressesion of inflammation is not completely understood. In this study, we determined how RG modulated gene expression in stressed brain cells. Since secretion of TNF-${\alpha}$ is modulated via TNF-${\alpha}$ converting enzyme (TACE) and nuclear factor (NF)-${\kappa}B$, we examined the inflammatory pathway in stressed brain cells. Immunohistochemistry revealed that TACE was induced by IMO stress, but RG repressed TACE induction. Moreover, PADI4 siRNA repressed TACE expression compared to the mock transfected control suggesting that PADI4 was required for TACE expression. A reporter assay also revealed that $H_2O_2$ oxidative stress induced NF-${\kappa}B$ in neuroblastoma SK-N-SH cells, however, RG pretreatment repressed NF-${\kappa}B$ induction. These findings were supported by significant induction of nitric oxide and reactive oxygen species (ROS) by oxidative stress, which could be repressed by RG administration. Taken together, RG appeared to repress stress-induced PADI4 via TACE and NF-${\kappa}B$ in brain cells thus preventing production of ROS and subsequently protecting brain cells from apoptosis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.139-141
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• 2005

It is possble to study charge transfer property which is caused by height variation because we can see the organic materials barrier height and STM tip by organic materials energy band gap. Here, we investigated the negative differential resistance(NDR) and charge transfer property of self-assembled 4,4-Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene, which has been well known as a conducting molecule. Self-assembly monolayers(SAMs) were prepared on Au(111), which had been thermally deposited onto pre-treatment($H_{2}SO_{4}:H_{2}O_{2}$=3:1) Si. The Au substrate was exposed to a 1 mM/l solution of 1-dodecanethiol in ethanol for 24 hours to form a monolayer. After thorough rinsing the sample, it was exposed to a $0.1{\mu}M/1$ solution of 4,4-Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene in dimethylformamide(DMF) for 30 min and kept in the dark during immersion to avoid photo-oxidation. After the assembly, the samples were removed from the solutions, rinsed thoroughly with methanol, acetone, and $CH_{2}Cl_{2}$, and finally blown dry with $N_2$. Under these conditions, we measured electrical properties of self-assembly monolayers(SAMs) using ultra high vacuum scanning tunneling microscopy(UHV-STM). The applied voltages were from -1.50 V to -1.20 V with 298 K temperature. The vacuum condition is $6{\times}10^{-8}$ Torr. As a result, we found that NDR and charge transfer property by a little change of height when the voltage is applied between STM tip and electrode.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.1844-1846
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• 2005

The characteristic of negative differential resistance(NDR) is decreased current when the applied voltage is increased. The NDR is potentially very useful in molecular electronics device schemes. Here, we investigated the NDR property of self-assembled 4,4- Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene, which has been well known as a conducting molecule. Self-assembly monolayers(SAMs) were prepared on Au(111), which had been thermally deposited onto pre-treatment$(H_2SO_4:H_2O_2=3:1)$ Si. The Au substrate was exposed to a 1mM/l solution of 1-dodecanethiol in ethanol for 24 hours to form a monolayer. After thorough rinsing the sample, it was exposed to a $0.1{\mu}M/l$ solution of 4,4-Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene in dimethylformamide(DMF) for 30 min and kept in the dark during immersion to avoid photo-oxidation. After the assembly, the samples were removed from the solutions, rinsed thoroughly with methanol, acetone, and $CH_2Cl_2$, and finally blown dry with $N_2$. Under these conditions, we measured electrical properties of self-assembly monolayers(SAMs) using ultra high vacuum scanning tunneling microscopy(UHV-STM). The applied voltages were from -2V to +2V with 299K temperature. The vacuum condition is $6{\times}10^{-8}$ Torr. As a result, we found the NDR voltage of the nitro-benzene is $-1.61{\pm}0.26$ V(negative region) and $1.84{\pm}0.33$ (positive region), respectively.

• 한국토양비료학회지
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• 제11권1호
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• pp.17-24
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• 1978

아연결핍(亞鉛欠乏)에 의한 적고발생답(赤枯發生畓)에 대(對)하여 함아연입상용인(含亞鉛粒狀熔燐)과 함아연복합비료(含亞鉛複合肥料)를 시용(施用)하여 효과를 살펴본 바 그 결과(結果)는 다음과 같다. 1. 적고발생답토양(赤枯發生畓土壤)의 석회함량(石灰含量)은 10.5me/100g로서 많았고, pH는 7.03으로서 중성(中性)이었으며, 유효아연은 평균(平均) 3.35ppm, 유효규산은 67.7ppm로서 매우 낮았다. 2. 아연무처리구(亞鉛無處理區)에서의 수도체중(水稻體中)의 아연함량(亞鉛含量)은 이앙후(移秧後) 20일(日)과 출수기(出穗期)에 있어서는 22~23ppm로서 아연흠핍증(亞鉛欠乏症) 발생한계농도(發生限界濃度)인 20ppm를 약간(若干) 상회(上廻)하고 있으나 수확기(收穫期)에는 15ppm로서 훨씬 낮은 값을 보였다. 3. 수도체중(水稻體中)의 N/Zn와 $P_2O_5/Zn$의 비(比)는 아연시용량(亞鉛施用量)이 많을수록 아연무시용구(亞鉛無施用區)($G_0$, $C_0$)에 비(比)해서 낮아지는 경향(傾向)이었다. 4. 초장(草長)과 분벽경수(分蘗莖數)는 아연시용량(亞鉛施用量)의 증가(增加)에 따라 증대(增大)하는 경향(傾向)이었고 출수(出穗)는 아연시용구(亞鉛施用區)가 무시용구(無施用區)에 비해서 약(約 )2주일(週日) 빨랐다. 5. 아연시용구(亞鉛施用區)는 무시용구(無施用區)에 비(比)해서 수량구성요소(收量構成要素)의 제형질(諸形質)을 크게 증대(增大)시켰으며, 특(特)히 정조수량(精粗收量)과 현미수량(玄米收量)에 있어서는 고도(高度)의 유의차(有意差)를 보였으나 아연시용(亞鉛施用) 구간(區間)에는 유의차(有意差)가 인정(認定)되지 않았다.

• 한국토양비료학회지
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• 제19권4호
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• pp.321-325
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• 1986

유효규산함량이 61 ppm 사양토(砂壤土)에서 규회석(硅灰石) 및 규산질비료시용(珪酸質肥料施用)에 의한 규산용출(珪酸溶出)의 변화(變化)에 관(關)해서 실내(室內) 시험(試驗)을 수행(遂行)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 규회석(硅灰石) 및 규산질비료(珪酸質肥料)를 토양(土壤)에 처리(處理)하고 증류수(蒸溜水) 및 1N-NaOAc(pH 4.0)로 연속침출(連續浸出)했을 때 각(各) 침출용액중(浸出溶液中)의 규산용출농도(珪酸溶出濃度)는 규회석(硅灰石)보다 규산질비료(珪酸質肥料) 처리(處理)에서 높았다. 2. 규회석(硅灰石) 및 규산질비료(珪酸質肥料)를 토양(土壤)에 처리(處理)하고 증류수(蒸溜水)로 연속침출(連續浸出)했을 때 pH는 규산질비료(珪酸質肥料)보다 규회석처리(硅灰石處理)에서 높았다. 3. 규회석(硅灰石) 및 규산질비료(珪酸質肥料)를 토양(土壤)에 처리(處理)하고 항온(恒溫)했을 때 규회석처리(硅灰石處理)는 시용량(施用量)이 많아짐에 따라 수용액중(水溶液中)의 $SiO_2$ 및 K 농도(濃度)는 낮아졌고 규산질비료(珪酸質肥料)에서는 높아졌으며 pH, Ca 및 Mg 농도(濃度)은 두비종(肥種) 모두 높아졌다. 4. 토양(土壤)에 pH를 달리하여 규산용액(珪酸溶液)을 흡착(吸着)시킨 결과(結果) pH 9.4 정도(程度)에서 최대(最大)로 흡착(吸着)되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.66-66
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• 2008

Most of the properties of ITO films depend on their substrate nature, deposition techniques and ITO film composition. For the display panel application, it is normally deposited on the glass substrate which has high strain point (>575 degree) and must be deposited at a temperature higher than $250^{\circ}C$ and then annealed at a temperature higher than $300^{\circ}C$ in order to high optical transmittance in the visible region, low reactivity and chemical duration. But the high strain point glass (HSPG) used as FPDs is blocking popularization of large sizes FPDs because it is more expensive than a soda lime glass (SLG). If the SLG could be used as substrate for FPDs, then diffusion of Na ion from the substrate occurs into the ITO films during annealing or heat treatment on manufacturing process and it affects the properties. Therefore proper care should be followed to minimize Na ion diffusion. In this study, we investigate the electrical, optical and structural properties of ITO films deposited on the SLG and the Asahi glass(PD200) substrate by rf magnetron sputtering using a ceramic target ($In_2O_3:SnO_2$, 90:10wt.%). These films were annealed in $N_2$ and air atmosphere at $400^{\circ}C$ for 20min, 1hr, and 2hrs. ITO films deposited on the SLG show a high electrical resistivity and structural defect as compared with those deposited on the PD200 due to the Na ion from the SLG on diffuse to the ITO film by annealing. However these properties can be improved by introducing a barrier layer of $SiO_2$ or $Al_2O_3$ between ITO film and the SLG substrate. The characteristics of films were examined by the 4-point probe, FE-SEM, UV-VIS spectrometer, and X-ray diffraction. SIMS analysis confirmed that barrier layer inhibited Na ion diffusion from the SLG.

• Tuberculosis and Respiratory Diseases
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• 제48권4호
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• pp.530-542
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• 2000

연구배경 : 특발성 폐섬유화증은 병리조직학 소견이 usual interstitial pneumonia(UIP)이면서 치료반응과 예후가 좋지 않은 질환이지만 1994년 처음 보고된 nonspecific interstitial pneumonia(NSIP)는 UIP와는 달리 치료반응 및 예후가 매우 좋아 정확한 감별 진단 및 적극적인 치료가 필요하지만 아직 특발성 NSIP의 임상적 특징 및 치료경과에 대한 보고가 별로 없어 UIP와의 감별이 쉽지 않은 실정이다. 방 법 : 1996년 7월부터 2000년 3월까지 성균관의대 삼성서울병원에서 외과적 폐생검을 통해 미만성 간질성 폐질환으로 확진된 120명 중 총 18례의 특발성 NSIP에 대한 임상적 특징 및 치료 경과를 의무기록 조사 및 방사선학적 분석을 통해 후향적으로 평가하였다. 결 과 : 1) 진단당시의 임상적 특징 18명의 환자중 17명이 여자였고 평균 연령은 $55.2{\pm}8.4$세(44~73세)였으며 호흡곤란 및 기침 이외에 발열이 6명의 환자에서 판정되었다. 이학적검사상 곤봉지는 1명에서만 관찰되었고 증상 발현후 병원을 찾기까지의 기간은 $7.3{\pm}16.9$개월, 외과적 폐생검까지의 기간은 $9.9{\pm}17.1$개월이었다. BAL 검사상 림프구가 $23.0{\pm}13.1%$로 증가되어 있었고 흉부 HRCT 소견상 봉와양 음영은 전혀 관찰되지 않으면서 간유리 음영 및 불규칙 선상 음영이 주로 관찰되었다. 2) 치료약제 및 부작용 13명이 스테로이드로 먼저 치료를 시작하였고 5명은 경구 cyclophosphamide 단독으로 치료를 시작하였다. 스테로이드로 치료를 시작한 13명 종 3명은 치료개시 1달 이내에 심각한 부작용으로 스테로이드 복용을 중단하여 2명은 경구 cyclophosphamide로 전환하여 치료를 계속할 수 있었으나 스테로이드 유발성 정신병이 유발된 1명은 향후 모든 치료를 포기하였다. 스테로이드로 치료를 계속 받은 10명에서는 대상포진 3례, 백내장 2례, 결핵 1례, 대퇴골 허혈 괴사 1례, 당뇨 1례 등이 유발되었고 7명의 경구 cyclophosphamide 복용 환자에서는 출혈성 방광염 1례, 대상포진 1례, 반복성 질염 1례 등이 부작용으로 나타났다. 3) 약물 치료후 반응 치료 시작후 $24.1{\pm}11.2$개월간 추적 관찰한 결과, 스테로이드를 복용한 10명 중 9명이 호전, 1명이 안정 상태를 보였고 경구 cyclophosphamide를 복용한 7명에서는 5명이 호전, 2명이 안전 상태를 보였다. 폐기능검사상 FVC(n=15)는 예측치 절대값으로 $20.2{\pm}11.2%$가 증가하였고 흉부 HRCT 소견상 간유리 음영의 면적(n=15)은 절대값으로 $15.7{\pm}14.7%$가 감소하였으며 추적검사상 봉와양 음영이 나타난 환자는 전혀 없었다. 4) 약물 치료 중단후 재발 호전후 약물 치료를 중단하였던 14명 중 5명이 재발하였고 2명은 스테로이드 감량중 악화되었다. 재발한 4명은 치료 중단 6개월 이내에, 1명은 10개월째에 재발하였고 치료 중단 1년내에 재발이 없었던 4명의 환자는 이후에도 재발의 증거가 전혀 없었다. 추적 관찰 기간($24.1{\pm}11.2$개월)중에 사망한 환자는 1명도 없었다. 결 론 : NSIP는 뚜렷한 임상적 특징과 좋은 치료 반응을 보이므로 예후가 좋지 않은 UIP와 적극적으로 감별하여 치료를 시행해야 할 것으로 사료된다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2000년도 추계학술발표회 초록집
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• pp.3-4
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• 2000

Many researchers are interested in the synthesis and characterization of carbon nitride and diamond-like carbon (DLq because they show excellent mechanical properties such as low friction and high wear resistance and excellent electrical properties such as controllable electical resistivity and good field electron emission. We have deposited amorphous carbon nitride (a-C:N) thin films and DLC thin films by shielded arc ion plating (SAIP) and evaluated the structural and tribological properties. The application of appropriate negative bias on substrates is effective to increase the film hardness and wear resistance. This paper reports on the deposition and tribological OLC films in relation to the substrate bias voltage (Vs). films are compared with those of the OLC films. A high purity sintered graphite target was mounted on a cathode as a carbon source. Nitrogen or argon was introduced into a deposition chamber through each mass flow controller. After the initiation of an arc plasma at 60 A and 1 Pa, the target surface was heated and evaporated by the plasma. Carbon atoms and clusters evaporated from the target were ionized partially and reacted with activated nitrogen species, and a carbon nitride film was deposited onto a Si (100) substrate when we used nitrogen as a reactant gas. The surface of the growing film also reacted with activated nitrogen species. Carbon macropartic1es (0.1 -100 maicro-m) evaporated from the target at the same time were not ionized and did not react fully with nitrogen species. These macroparticles interfered with the formation of the carbon nitride film. Therefore we set a shielding plate made of stainless steel between the target and the substrate to trap the macropartic1es. This shielding method is very effective to prepare smooth a-CN films. We, therefore, call this method "shielded arc ion plating (SAIP)". For the deposition of DLC films we used argon instead of nitrogen. Films of about 150 nm in thickness were deposited onto Si substrates. Their structures, chemical compositions and chemical bonding states were analyzed by using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and infrared spectroscopy. Hardness of the films was measured with a nanointender interfaced with an atomic force microscope (AFM). A Berkovich-type diamond tip whose radius was less than 100 nm was used for the measurement. A force-displacement curve of each film was measured at a peak load force of 250 maicro-N. Load, hold and unload times for each indentation were 2.5, 0 and 2.5 s, respectively. Hardness of each film was determined from five force-displacement curves. Wear resistance of the films was analyzed as follows. First, each film surface was scanned with the diamond tip at a constant load force of 20 maicro-N. The tip scanning was repeated 30 times in a 1 urn-square region with 512 lines at a scanning rate of 2 um/ s. After this tip-scanning, the film surface was observed in the AFM mode at a constant force of 5 maicro-N with the same Berkovich-type tip. The hardness of a-CN films was less dependent on Vs. The hardness of the film deposited at Vs=O V in a nitrogen plasma was about 10 GPa and almost similar to that of Si. It slightly increased to 12 - 15 GPa when a bias voltage of -100 - -500 V was applied to the substrate with showing its maximum at Vs=-300 V. The film deposited at Vs=O V was least wear resistant which was consistent with its lowest hardness. The biased films became more wear resistant. Particularly the film deposited at Vs=-300 V showed remarkable wear resistance. Its wear depth was too shallow to be measured with AFM. On the other hand, the DLC film, deposited at Vs=-l00 V in an argon plasma, whose hardness was 35 GPa was obviously worn under the same wear test conditions. The a-C:N films show higher wear resistance than DLC films and are useful for wear resistant coatings on various mechanical and electronic parts.nic parts.