• 원예과학기술지
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• 제31권5호
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• pp.544-551
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• 2013

The effect of different silicon (Si) sources and methods of application on the growth of two chrysanthemum cultivars grown in a soilless substrate was investigated. Rooted terminal cuttings of Dendranthema grandiflorum 'Lemmon Eye' and 'Pink Eye' were transplanted into pots containing a coir-based substrate. A nutrient solution containing 0 or $50mg{\cdot}L^{-1}$ Si from calcium silicate ($CaSiO_3$), potassium silicate ($K_2SiO_3$) or sodium silicate ($Na_2SiO_3$) was supplied once a day through an ebb-and-flood sub irrigation system. A foliar spray of 0 or $50mg{\cdot}L^{-1}$ Si was applied twice a week. Cultivar and application method had a significant effect on plant height. Cultivar, application method, and Si source had a significant effect on plant width. Of the three Si sources studied, $K_2SiO_3$ was found to be the best for the increasing number of flowers, followed by $CaSiO_3$ and $Na_2SiO_3$. In both the cultivars, sub irrigational supply of Si developed necrotic lesions in the older leaves at the beginning of the flowering stage as compared to the control and foliar spray of Si. Cultivar, application method, Si source, and their interactions had significant influence on leaf tissue concentrations of calcium (Ca), potassium (K), phosphorus (P), magnesium (Mg), sulfur (S), sodium (Na), boron (B), iron (Fe), and zinc (Zn). The addition of Si to the nutrient solution decreased leaf tissue concentrations of Ca, Mg, S, Na, B, Cu, Fe, and Mn in both cultivars. The greatest Si concentration in leaf tissue was found in 'Lemmon Eye' ($1420{\mu}g{\cdot}g^{-1}$) and 'Pink Eye' ($1683{\mu}g{\cdot}g^{-1}$) when $K_2SiO_3$ was applied through a sub irrigation system and by foliar spray, respectively.

• 한국식생활문화학회지
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• 제27권1호
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• pp.66-74
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• 2012

It is well known that sunflower (SF) sprout has more beneficial effects than SF seed due to increased levels of phytochemical components such as vitamins, total phenolics, and isoflavones during germination. This study investigated the physicochemical properties and antioxidative activities of SF seed during both germination and cultivation. In a proximate analysis, the water content of SF groat was 9.17% and then increased to 15.32% on the 11th day after seeding. On a dry weight basis, crude fat content decreased while the contents of carbohydrates, crude protein, and crude ash increased. As cultivation proceeded, the contents of minerals were in decreasing order of K, Mg, Ca, Na, Zn, Fe, Mn, and Cu, in which SF sprout cultivated for 9 or 11 days contained the highest mineral contents. Though vitamin C was not detected on SF groat, the content of vitamin C continuously increased up to the 5th day of cultivation and then decreased gradually. Vitamin E content in SF groat was higher than that in SF sprout. It was also found that the vitamin E content in SF sprout was the highest on the 5th day of cultivation. Daidzin was not detected in SF groat, but its concentration reached a maximum on the 5th day of cultivation in SF sprouts. Furthermore, higher amounts of daidzein were observed on the 3rd, 5th, and 9th days of cultivation. The highest total isoflavone content was observed on either the 3rd or 5th day of cultivation. The highest content of total phenolics was observed on the 5th of cultivation. When DPPH radical and peroxyl radical scavenging activities of SF sprout were measured in order to measure antioxidant efficacy, it was found that 5 day-cultivated SF sprout had the highest scavenging activities. In conclusion, SF sprout cultivated for 9 or 11 days was found to be a good source of minerals. Furthermore, the fifth-day after seeding was the optimal time for the production of SF sprout with effective natural antioxidant activity and high amounts of functional components such as vitamins, total phenolics, and isoflavones.

• E2M - 전기 전자와 첨단 소재
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• 제12권7호
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• pp.7-11
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• 1999

Fully sealed field emission display in size of 4.5 inch has been fabricated using single-wall carbon nanotubes-organic vehicle com-posite. The fabricated display were fully scalable at low temperature below 415$^{\circ}C$ and CNTs were vertically aligned using paste squeeze and surface rubbing techniques. The turn-on fields of 1V/${\mu}{\textrm}{m}$ and field emis-sion current of 1.5mA at 3V/${\mu}{\textrm}{m}$ (J=90${\mu}{\textrm}{m}$/$\textrm{cm}^2$)were observed. Brightness of 1800cd/$m^2$ at 3.7V/${\mu}{\textrm}{m}$ was observed on the entire area of 4.5-inch panel from the green phosphor-ITO glass. The fluctuation of the current was found to be about 7% over a 4.5-inch cath-ode area. This reliable result enables us to produce large area full-color flat panel dis-play in the near future. Carbon nanotubes (CNTs) have attracted much attention because of their unique elec-trical properties and their potential applica-tions [1, 2]. Large aspect ratio of CNTs together with high chemical stability. ther-mal conductivity, and high mechanical strength are advantageous for applications to the field emitter [3]. Several results have been reported on the field emissions from multi-walled nanotubes (MWNTs) and single-walled nanotubes (SWNTs) grown from arc discharge [4, 5]. De Heer et al. have reported the field emission from nan-otubes aligned by the suspension-filtering method. This approach is too difficult to be fully adopted in integration process. Recently, there have been efforts to make applications to field emission devices using nanotubes. Saito et al. demonstrated a car-bon nanotube-based lamp, which was oper-ated at high voltage (10KV) [8]. Aproto-type diode structure was tested by the size of 100mm $\times$ 10mm in vacuum chamber [9]. the difficulties arise from the arrangement of vertically aligned nanotubes after the growth. Recently vertically aligned carbon nanotubes have been synthesized using plasma-enhanced chemical vapor deposition(CVD) [6, 7]. Yet, control of a large area synthesis is still not easily accessible with such approaches. Here we report integra-tion processes of fully sealed 4.5-inch CNT-field emission displays (FEDs). Low turn-on voltage with high brightness, and stabili-ty clearly demonstrate the potential applica-bility of carbon nanotubes to full color dis-plays in near future. For flat panel display in a large area, car-bon nanotubes-based field emitters were fabricated by using nanotubes-organic vehi-cles. The purified SWNTs, which were syn-thesized by dc arc discharge, were dispersed in iso propyl alcohol, and then mixed with on organic binder. The paste of well-dis-persed carbon nanotubes was squeezed onto the metal-patterned sodalime glass throuhg the metal mesh of 20${\mu}{\textrm}{m}$ in size and subse-quently heat-treated in order to remove the organic binder. The insulating spacers in thickness of 200${\mu}{\textrm}{m}$ are inserted between the lower and upper glasses. The Y\ulcornerO\ulcornerS:Eu, ZnS:Cu, Al, and ZnS:Ag, Cl, phosphors are electrically deposited on the upper glass for red, green, and blue colors, respectively. The typical sizes of each phosphor are 2~3 micron. The assembled structure was sealed in an atmosphere of highly purified Ar gas by means of a glass frit. The display plate was evacuated down to the pressure level of 1$\times$10\ulcorner Torr. Three non-evaporable getters of Ti-Zr-V-Fe were activated during the final heat-exhausting procedure. Finally, the active area of 4.5-inch panel with fully sealed carbon nanotubes was pro-duced. Emission currents were character-ized by the DC-mode and pulse-modulating mode at the voltage up to 800 volts. The brightness of field emission was measured by the Luminance calorimeter (BM-7, Topcon).

• 한국패류학회지
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• 제22권2호
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• pp.157-165
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• 2006

바지락의 중금속의 농축 방식 및 해독기작을 연구하기 위해 소화선, 소화관 및 아가미등 세 기관을 선택하여 면역조직화학적 방법, 미세구조적 연구 그리고 SEM-EDS를 사용한 MT와 중금속의 분포 양상을 지역별로 채집한 샘플과 Cd-Cu에 시간별로 노출시킨 샘플에서 각각 살펴보았다. 중금속에 의해 유도된 MT 단백질이 면역조직화학적인 방법에 의해 붉은 색으로 표지되었다. 노출시간이 길어질수록 간췌장에서는 diverticula의 외곽으로 강한 반응을 보였으며, 아가미에서는 중금속의 노출시간이 길어질수록 노출되지 않은 조직에 비해 전반적으로 더 넓은 지역에서 강하게 반응을 보였다. 간췌장과 아가미를 투과전자현미경으로 관찰한 결과 중금속(Cd) 에 더 오래 노출될수록 세포질에서 inclusion body와 중금속으로 추정되는 과립들을 다수 관찰할 수 있었으며, 핵막이 swelling 되는 현상을 관찰할 수 있었다. 또한 발달된 조면 소포체와 미토콘드리아가 관찰되었다. SEM-EDS 결과 중금속의 분포 양상이 지역별로 상당히 상이한 결과를 나타났는데, 이는 지역별로 중금속의 오염정도와 오염원이 되는 중금속의 종류가 다르기 때문으로 추측된다. 그리고 지역별로 채집한 바지락을 이용한 실험과 S와 Zn의 수치가 높게 나타나는 것으로 보아 MT가 관여하고 있음을 간접적으로 확인할 수 있었다.

• 원예과학기술지
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• 제33권1호
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• pp.39-46
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• 2015

'설향' 딸기를 재배하는 동안 비료의 종류와 농도를 변화시켜 시비하고 작물 생장과 양분 흡수량 변화에 미치는 영향을 구명하여 시비를 위한 기초자료를 확보하고자 본 연구를 수행하였다. 증류수를 원수로 산성, 중성 및 알칼리성 비료를 조제한 후 N 농도를 기준으로 $100mg{\cdot}L^{-1}$ 및 $200mg{\cdot}L^{-1}$로 그리고 처리용액의 pH를 약 6.0-6.3으로 조절하여 100일간 시비하였다. 동일한 시비농도에서 시비 100일 후 '설향' 딸기의 생체중 및 건물중은 산성비료를 시비한 처리가 가장 가벼웠고 알칼리비료 처리가 무거웠다. 또한 알칼리비료의 $100mg{\cdot}L^{-1}$보다 $200mg{\cdot}L^{-1}$로 시비한 처리의 생체중과 건물중이 더 무거웠다. 식물체 무기원소 함량을 분석한 결과 N, P 및 Na은 중성비료 $200mg{\cdot}L^{-1}$ 처리에서 각각 3.08, 0.54 및 0.10%로, K은 산성비료 $200mg{\cdot}L^{-1}$ 처리에서 2.83%로, Ca과 Mg은 알칼리비료 $100mg{\cdot}L^{-1}$ 처리에서 0.98 및 0.42%로 다른 처리들보다 유의하게 식물체 내 함량이 높았다. Fe, Mn, Zn 및 Cu 함량은 산성비료를 시비한 처리에서 높았고, 알칼리비료를 시비한 처리에서 뚜렷하게 낮았다. 근권부 pH는 산성비료 $100mg{\cdot}L^{-1}$ 및 $200mg{\cdot}L^{-1}$, 그리고 중성비료 $200mg{\cdot}L^{-1}$으로 시비한 처리에서 지속적으로 낮아졌다. 근권부 무기원소 농도는 산성비료 $200mg{\cdot}L^{-1}$, 중성비료 $200mg{\cdot}L^{-1}$, 그리고 산성비료를 $100mg{\cdot}L^{-1}$으로 시비한 처리 순으로 $NH_4$ 농도가 낮아졌다. 근권부 K 농도는 시비 42일 후부터 모든 처리에서 지속적으로 상승하였으며, Ca 및 Mg 농도는 시비 84일 후 까지는 알칼리비료를 시비한 처리의 농도가 가장 낮고 중성 비료 및 산성 비료 순으로 높아지는 경향이었다. $NO_3$는 산성비료에서 낮았고, 중성 및 알칼리비료의 순으로 높아졌다. 세 종류 비료를 동일한 농도로 시비한 경우 $PO_4$ 농도가 유사한 경향을 보이며 변화하였고, $SO_4$은 시비 70일 후까지 산성 비료가 중성이나 알칼리성 비료를 시비한 처리들보다 높았다. 이상의 연구결과는 '설향' 딸기 재배에서 알칼리성 비료를 시비해야 함을 의미하며, 알칼리 원소의 농도가 상승하도록 관비용액의 조성을 변화시켜야 한다고 판단하였다.

• 자원환경지질
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• 제2권3호
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• pp.1-25
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• 1969

In considering the mining industry, it is necessary to study the production, consumption and price of ore and metals in every country of the world in order to determine the trend of the industry in the present and for the future. This study is necessary especially for exporting domestically produced are which is in excess of domestic consumption and for importing are, or metal where local production does not meet domestic demand. It will be treated of Au, Ag, Cu, Pb, Zn, W, Mo, which are the most important non-ferrous metals, and which greatly affect the mining industry of Korea. The presentation will concern itself only with the free world. About 1, 200 ton of gold are produced annually with little fluctiation in recent years. Most of the gold produced is consumed by advanced countries for industrial uses as well as for producing precious objects. The U.S.A. expends yearly about four times its domestic production and Japan about three times its domestic production for industry and arts. Because of the instability of the currency of the U.S.A., England and France, recently, the price of gold has been $ 41-42 per ounce, whereas the official price is $35.00 per ounce. It will be expected that the official price will be raised in the near future. As for silver, about 6,500 tons are produced annually with no special fluctuation change in recent years. However, the annual consumption is about 14,000 ton, so the supply and demand is extremely unbalanced. The shortage is made up by the sale of the U.S. treasury's reserve stock and the reclaiminig of silver from coins and other scrap. As the Treasury'S reserves will be exhausted in a year or two, the price of silver which is $1. 64 per ounce, will go up drastically in about a year. As for copper, 5,257,000 ton's were mined in 1966. It's production is being increased about 5% annually. However, consumption exceeds production by about 100,000 ton a year. The recent Foreign refinery copper price in the U.S.A is $ 60 per pound. The supply of copper being insufficient to meet international demands, the price will go up and with no prospect of being lowered in the near future even with the slight annual increase in production. About 2,100,000 to 2,200,000 tons of lead are produced annually. Consumption exceeds production by about 50,000-60,000 tons annually. The current price of lead in New York is $ 155 per pound. As the supply of lead is internationally stable, It will be believed that there will be no significant change in its price in the near future. In 1967, 3,926,000 tons of Zinc were produced. There is annual increase of 4-7% in production. The annual consumption exceeds production by 100,000 to 200,000 tons. The current zinc price in the St. Louis market inthe U.S.A. is $ 145 per pound. Even though its supply is stable and sufficient world wide, the consumption rate will increase at a faster pace than before; hence, the price will slowly go up. Tungsten mines yield about 11,000 tons a year. Its production has been relatively constant in the past few years. The amount of its consumption increases slowly world wide, but in the free world· there has been a slight annual decrease. However, since Red China has not been exporting their tungsten to other countries for several months, the price on the London market of S.T.U. of $Wo_3$ has increased to $ 44~46. Should Red China begin to export actively again the price will drop to $ 40~42. In 1967, 56,000 tons of Molybdenum were produced. Production exceeds consumption by 200,000 -30,000 tons annually. The current price in the U.S.A. is $ 1.72 per Mo pound. Since the rate of production in the U.S.A. is on the increase with large amounts of ore reserve, the price of molubdenum should not go up.

• 한국지구과학회지
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• 제24권7호
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• pp.635-649
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• 2003

마산만의 오염과정을 파악하기 위하여 3개 정점의 코어 퇴적물에서 중금속 함량과 저서성 유공충의 분포를 조사하였다. 마산만의 퇴적속도는 마산항 0.33 cm/yr, 덕동 하수종말 처리장 앞 0.20 cm/yr, 마산만 입구 0.33 cm/yr로 나타났다. 퇴적물 깊이 약 15 cm부터 표층까지 Cu, Zn, Pb 함량이 뚜렷하게 증가하는 것은 1940년대 이후 점진적으로 축적되던 오염물질이 1960년대 이후 산업폐기물에 의해 급격하게 증가했기 때문인 것으로 해석된다. 코어 퇴적물에서 나타나는 저서성 유공충의 수직적인 분포는 오염에 따른 유공충의 반응을 잘 나타내고 있다. 퇴적물 상부로 중금속 함량이 증가함에 따라 개체수와 종 다양성은 감소하고 사질유공충의 비율은 증가하였다. 이러한 현상은 오염이 증가함에 따라 몇몇 내성종들 만이 존재함으로써 결과적으로 종 다양성이 감소하였음을 반영한다. 기회종인 Eggerella advena와 Trochammina pacifica는 오염퇴적물에서 뚜렷한 증가를 보였다. 이러한 종들은 마산만의 현생 오염 환경을 평가할 수 있는 유용한 환경 지시자로 사용될 수 있을 것이다.

• 분석과학
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• 제25권6호
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• pp.441-446
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• 2012

본 연구에서는 안동호 퇴적물 중의 총 수은, 메틸수은, 중금속 농도를 조사하고 퇴적물과 수체간의 수은 이동량을 산정하였다. 안동호 퇴적물 중 수은 농도는 2009~2011 년에 각각 $155.0{\pm}71.9$ ng/g, $211{\pm}62$ ng/g 및 $198{\pm}6.88$ ng/g이었으며, 메틸수은은 2009 년 및 2011 년에 각각 $1.85{\pm}1.09$ ng/g, $3.49{\pm}1.79$ ng/g이었고, 총수은에 대한 메틸수은의 분율인 %메틸수은은 $1.17{\pm}0.39%$ 및 $1.77{\pm}0.94%$로 나타났다. 퇴적물 중 아연, 카드뮴, 납, 구리의 농도는 644 mg/kg, 7.3 mg/kg, 67 mg/kg, 42 mg/kg 으로 모두 미국 국립해양대기청(NOAA, National Oceanic and Atmospheric Administration)에서 제시한 퇴적물 기준(SQGs, Sediment Quality Guidelines)중의 최소 무영향 농도(ERL, Effect Range Low) 수준을 초과하는 수준이었다. 안동호에서 퇴적물로의 수은 이동량은 83.7 $ng/cm^2{\cdot}$년, 퇴적물에서부터 수체로의 수은 확산속도는 1.24 $ng/cm^2{\cdot}$년으로 추정되었다.

• 미생물학회지
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• 제20권3호
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• pp.125-133
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• 1982

Mutational experiments were performed to imporve the cellulase productivity of Aspergillus phoenicis KU175, isolated from the southern part of Korea, as a high cellulase producer. By treatment ultra-violet light nad 4-NQO(4-Nitroquinoline-N-Oxide), mutation waas induced, and treatment ultra-violet light and 4-NQO (4-Nitroquinoline-N-Oxide), mutation was induced, and A.phoenicis KU175-115 was finally selected for its highest avicelase production. Avicelase production of the mutant was increased about 2 times compared with those of the wild strain. However, activities of other hydrolytic enzymes, such as amylase, protease and nuclease, of the mutant strain didn't show a marked difference compared with those of the nuclease, of the mutant strain didn't show a marked difference compared with the wild strain, except slight increase in ribonuclease activity and slight decrease in glucoamylase activity. Avicelases from the mutant strain selected were purified from wheat bran culture by successive salting out, followed by dialysis and column chromatography, and their charcteristics were compared with thosw of the wild strain. Avicelase was separated into three peaks in the mutant strain as well as in the case of wild strain. Avicelase II activity of the mutant strain was prominently higher than that of the wild strain, while avicelase I and III activities of those were equivalent. The optimal pH ranges and stability of avicelase II from the mutant strain were pH4-5 and pH3.5-6.0, respectively, as well as in the case of the wild strain. The optimal temperature and thermal stability of avicelase II from the mutant strain were $40{\sim}50^{\circ}C\;and\;20{\sim}55^{\circ}C$, respectively. These results were same as those of the wild strain. By the using of Eadie-Hofastee plot, $K_m\;and\;V_{max}$ of avicelase II from the mutant and the wild strain were calculated to be 2.29mg/ml and $4.84{\mu}g$ reducing sugar as glucose per min equally, from the line fitted to the data by the least square method. Activity of avicelase II from the mutant strain was slightly activated by $Mg^{++}\;but\;inhibited\;by\;Cu^{++}, \;Mn^{++}\;and\;Zn^{++}$, as well as in the case of the wild strain. Therefore, it was concluded that the mutant didn't induce the formation of another avicelase isozyme, or the changes in the properties of avicelase, but induce the changes in the productively of the same avicelase II by the action of regulatory gane.

• 한국식품영양과학회지
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• 제14권3호
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• pp.274-279
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• 1985

년근별(年根別)에 따른 더덕의 일반성분(一般成分), 무기질(無機質) 및 단백질(蛋白質) 성분(成分)을 atomic absorption spectro-photometer, spectrophotometer 및 disc gel electrophoresis에 의한 분석(分析) 결과(結果)는 다음과 같았다. 일반성분(一般成分)은 재배더덕이나 야생더덕에 관계없이 총당(건물중)이 가장 많이 함유된 성분이고 1년근이 68.76%, 5년근이 66.54%로써 재배 년령이 높아짐에 따라 다소 함량이 감소되는 경향이었다. 그 다음 조단백질, 조섬유, 조지방, 회분의 순으로 함유되었고 조섬유를 재외하고는 재배더덕이 야생더덕 보다 그 성분함량이 다소 높았고 재배 년령이 높아짐에 따라 함량이 높아졌으나 조섬유는 별로 증가가 없었다. 무기성분은 K의 함량이 $208.7{\sim}327.9ppm$으로 가장 높았고 Mg, Ca가 그 다음으로 비슷한 함량을 보여 주었고 전반적으로 재배더덕이 야생더덕보다 무기질 함량이 높았으며 Fe를 제외하고는 대체적으로 재배 년근(年根)의 년령이 높아짐에 따라 무기성분 함량이 높아졌다. 그리고 중금속(重金屬)인 Pb와 Cd의 함량은 허용기준량보다 낮게 함유되어 있었다. P는 재배더덕이 야생더덕보다 함량이 3배 정도 높았다. 더덕의 단백질 분획중 가장 많이 함유된 것은 재배와 야생더덕에 상관없이 albumin이 었고 재배년령이 높아질수록 다소 함량이 감소되는 경향이었다. 그 다음 globulin, prolamin 및 glutelin의 순서로 함유되었고 대체로 년근(年根)의 년령이 높아감에 따라 그 함량이 증가되는 경향을 보여주었고 prolamin함량이 $19.74{\sim}22.90%$로 비교적 함량이 높았다. 더덕 단백질의 용해도는 pH 4에서 최소, pH 10에서 최대를 나타냈으며 disc gel 전기영동 패턴은 재배년령이나 재배와 야생더덕에 관계 없이 band의 형태와 수에 별 차이를 인지할 수 없었고 7개의 band로 나타났으며 이들의 주단백질(主蛋白質)의 분자량(分子量)은 약 90,000이었다.