• 한국작물학회지
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• 제62권1호
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• pp.1-8
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• 2017

벼 직파재배에서 새 피해, 발아 및 입모불량 그리고 도복피해 등 기술보급저해요인을 해소하기 위하여 개발된 규산 코팅볍씨의 이앙용 상자육묘에서 건묘육성과 벼키다리병 발병 경감을 구명하기 위하여 호기조건인 상자육묘조건과 혐기조건인 Pot이앙조건으로 수행한 결과는 다음과 같다. 1. 코팅볍씨에서 묘의 출현은 무코팅볍씨에서 보다 2-3일 빨랐고 입고병과 벼키다리병 발생이 현저히 경감되었다. 2. 파종후 45일 생체중은 건전묘에서 11%, 이병묘에서 2.01배로 규산코팅볍씨의 건묘 육성효과가 뚜렷하였다. 3. 육묘 중 파종후 80일까지 벼키다리병 발생은 무코팅볍씨 91.6%에 비하여 7.8%로 현저하게 경감되었다. 4. 최대발병률을 보인 파종 후 45일에 이앙된 코팅볍씨에서 무코팅볍씨에 비하여 건전묘의 추가발병이 거의 없었고 이병묘의 정상생육 회복도 가능하였다. 5. 코팅볍씨에서 육묘된 토양과 식물체의 뿌리와 엽초기부조직에서 활동성 소형포자와 대형포자의 분포가 무코팅에서보다 현저하게 줄었다. 특히 코팅볍씨의 육묘토양과 이병묘/건전묘에서는 무코팅볍씨에서 나타난 전형적인 대형포자(3-7개의 격막과 양끝이 낫처럼 굽은)와는 다른 격막이 없고 두터운 세포벽을 갖는 장방형 미성숙 대형포자 출현이 발병 경감원인으로 주목되었다. 6. 이상의 결과를 종합하여 보면 코팅볍씨의 육묘 중 벼키다리병 발병경감과 이앙 후 이병묘의 정상생육 회복 그리고 건전묘의 이병화경감은 강알칼리성 수용성 규산과 다공성 지오라이트 그리고 종피 잠복 병원균 간의 물리화학적 특성과 건전묘의 균에 대한 저항성에 기인되었을 것으로 판단되었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.268-268
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• 2017

Common sowing method of italian ryegrass (IRG) has been using the backpack seed sprayer (BSS) in Korea. It has weak point including a hard work and a little sowing area. This study was conducted to find out the effects of sowing IRG using unmanned helicopter (UH) under the established rice field. We checked the labour saving of sowing IRG and the growth and yield of rice after using IRG as forage crop. Two sowing implements(using by UH and backpack seed sprayer (BSS)) were tested for the ability of sowing IRG. For proper pretreatment of IRG seeds for aerial sowing using with UH, we tested one-day soaking seeds, iron-coated seeds, coated seeds sold in stores and untreated seeds. Aerial sowing of IRG seeds using UH was tested under the speed 10 km/h and flying altitude 3~4m. We tried to confirm the effects on rice growth in a paddy field after IRG had been used as forage in mid May. In 6 hours of seeding per day, UH had a seeding area of 21.8 hectares, three times wider than BSS. UH had a decrease of about 63 percent of sowing-seed cost in comparison with BSS. In the IRG aerial sowing using UH, coating seeds had the wider sowing width of 5~6 meter than 3~4 meter untreated seeds. Residual dry matter of IRG after using forage had 4.5 ton per hectare and 20 percent of top dry matter. The amount of nitrogen remaining in residual IRG in the soil was 12 kg per hectare, and the other nutrients such as calcium and potassium was incorporated into the soil with less than 10 kg/ha. The rice yield after the harvesting IRG was 5 percent higher than that of rice single cropping. Consequently, IRG sowing using UH was effective in reducing sowing time and sowing cost compared with conventional methods and, it is considered that there is a positive effect on the rice cultivation compared to rice single cropping.

• Journal of Microbiology
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• 제41권3호
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• pp.252-258
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• 2003

The carbon utilizations of Bacillus species and Pythium species were investigated by using a Biolog$^{(R)}$ microplate assay to determine if there are differences in the carbon utilizations of selected strains of these species. It may be possible to afford a competitive advantage to bacterial biological control agents by providing them with a substrate that they can readily use as a carbon source, for example, in a seed coating formulation. Microplates, identified as SFP, SFN and YT were used to identify spore-forming bacteria, nonspore-forming bacteria, and yeast, respectively. Bacterial and mycelial suspensions were adjusted to turbidities of 0.10 to 0.11 at 600 nm. One hundred microliters of each of the bacterial and mycelial suspension were inoculated into each well of each of the three types of microplates. L-arabinose, D-galactose, D-melezitose and D-melibiose of the 147 carbohydrates tested were found to be utilized only by bacteria, and not by Pythium species, by Biolog$^{(R)}$ microplate assay, and this was confirmed by traditional shake flask culture. Thus, it indicated that the Biolog$^{(R)}$ microplate assay could be readily used to search for specific carbon sources that could be utilized to increase the abilities of bacterial biological control agents to adapt to contrived environments.

• 한국결정성장학회지
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• 제15권6호
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• pp.260-262
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• 2005

Thickness optimization of heavily doped p-type seeding layer was studied to improve performance of thin film silicon solar cell. We used liquid phase epitaxy (LPE) to grow active layer of $25{\mu}m$ thickness on $p^+$ seeding layer. The cells with $p^+$ seeding layer of $10{\mu}m\;to\;50{\mu}m$ thickness were fabricated. The highest efficiency of a cell is 12.95%, with $V_{oc}=633mV,\;J_{sc}=26.5mA/cm^2$, FF = 77.15%. The $p^+$ seeding layer of the cell is $20{\mu}m$ thick. As thicker seeding layer than $20{\mu}m$, the performance of the cell was degraded. The results demonstrate that the part of the recombination current is due to the heavily doped seeding layer. Thickness of heavily doped p-type seeding layer was optimized to $20{\mu}m$. The performance of solar cell is expected to improve with the incorporation of light trapping as texturing and AR coating.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.168-171
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• 2005

Thickness optimization of heavily doped p-type seeding layer was studied to improve performance of thin film silicon solar cell. We used liquid phase epitaxy (LPE) to grow active layer of $25{\MU}m$ thickness on p+ seeding layer. The cells with p+ seeding layer of $10{\mu}m\;to\;50{\mu}m$ thickness were fabricated. The highest efficiency of a cell is $12.95\%$, with Voc=633mV, $Jsc=26.5mA/cm^2,\;FF=77.15\%$. The $P^+$ seeding layer of the cell is $20{\mu}m$, thick. As thicker seeding layer than $20{\mu}m$, the performance of the cell was degraded. The results demonstrate that the part of the recombination current is due to the heavily doped seeding layer. Thickness of heavily doped p-type seeding layer was optimized to $20{\mu}m$. The performance of solar cell is expected to improve with the incorporation of light trapping as texturing and AR coating.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.211-211
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• 2003

PbTiO$_3$ 씨앗층을 이용하여 완화형 강유전체 Pb(Mg$_{1}$3/Ta$_{2}$3/)O$_3$ (PMT) 박막의 페로브스카이트 상안정화와 열처리 조건에 따른 미세구조변화, 이에 따른 전기적 특성 변화에 관하여 조사하였다. PbTiO$_3$ 박막을 스핀코팅법으로 3000 rpm에서 20초간(111) 방향으로 배향된 Pt / Ti / SiO$_2$/ Si 기판에 증착하여 안정화된 페로브스카이트 박막을 얻었다. 이렇게 제조된 PbTiO$_3$를 Buffer 층으로 사용하고 그 위에 Pb(Mg$_{1}$3/Ta$_{2}$3/)O$_3$를 박막을 Spin coating방법으로 증착한 후, 급속열처리 방법(RTA)으로 550- $650^{\circ}C$ 사이에서 열처리하였다. 제조된 박막의 열처리 온도에 따른 미세구조 변화와 결정성을 XRD, SEM, TEM으로 분석하였고 박막의 저온 강유전 특성을 RT66A를 이용하여 평가하였다. Pb(Mg$_{1}$3/Ta$_{2}$3/)O$_3$ 박막의 경우 씨앗층이 없는 경우에는 pyrochlore상이 주상이었지만 씨앗층을 사용한 경우 페로브스카이트 상이 주상임을 확인하였고 열처리 온도가 증가할수록 페로브스카이트상의 상대적 양이 증가함을 확인하였다. 미세구조와 상의 변화에 따른 전기적 특성 변화에 관하여 자세하게 논의할 것이다.

• Journal of Applied Biological Chemistry
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• 제48권4호
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• pp.161-166
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• 2005

Among 24 isolates of fluorescent Pseudomonads, 5 isolates named as LPT1, LPT2, LPT3, LPT4 and LPT5 were screened in vitro for their nematicidal activity against cyst forming nematode, Heterodera cajani causing patchiness, poor and stunting growth besides discoloration in Sesamum indicum. Second stage juveniles of H. cajani hatched from egg masses were collected from roots of host plant and subjected to fresh and heat-treated culture filtrate of isolates for 24 h. Mortality of H. cajani was recorded on the basis of parameters used for test organism bioassay. Among these isolates, Pseudomonas aeruginosa LPT5 caused maximum mortality towards second stage juvenile of H. cajani in vitro. Five isolates were used as seed coating for the management of cyst forming nematode H. cajani on sesame in green house condition. The strains LPT5 was better than the other strains in reducing the population of H. cajani both in vitro and in vivo. The reduction in cyst and juveniles population was found to be 49 and 60%, respectively when seeds were coated with strain LPT5. Among other strains, LPT4 was also found to inhibit the cyst and juveniles population 12 and 36% respectively. Increases in early vegetative plant growth parameters recorded in both in vitro and in vivo further revealed the significance of indigenous bacteria in comparison to introduced strain.

• 한국세라믹학회지
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• 제34권4호
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• pp.406-412
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• 1997

Al2O3/SiC hybrid-composite has been fabricated by the conventional powder process. The addition of $\alpha$-Al2O3 as seed particles in the transformation of ${\gamma}$-Al2O3 to $\alpha$-Al2O3 provided a homogeneity of the microstructure. The grain growth of Al2O3 are significantly surpressed by the addition of nano-size SiC particles. Dislocation were produced due to the difference of thermal expansion coefficient between Al2O3 and SiC and piled up on SiC particles in Al2O3 matrix, resulting in transgranular fracture. The high fracture strength of the composite was contributed to the grain refinement and the transgranular fracture mode. The addition of SiC platelets to Al2O3/SiC nano-composite decreased the fracture strength, but increased the fracture toughness. Coated SiC platelets with nitrides such as BN and Si3N4 enhanced fracture toughness much more than non-coated SiC platelets by enhancing crack deflection.

• 한국염색가공학회지
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• 제22권1호
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• pp.77-82
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• 2010

Highly conductive yarn was successfully obtained using electroless nickel plating method with palladium activation. In the presence of palladium seed on surface of fibers as a catalyst, continuos nickel layer produced on surface of fibers by reducing $Ni${2+}$ ion in the electroless plating bath to $Ni^0$. It was found that the Pd-activation using $SnCl_2$ and $PdCl_2$ to deposit palladium seeds on the surface of fibers plays a key role in the subsequent electroless plating of nickel. It also found that electroless nickel plating on the fibers can induce the nickel-plated $ELEX^{(R)}$ fibers to improve the electrical conductivity of the fibers. The thickness of nickel coating layer on the Pd-activated $ELEX^{(R)}$ fibers and specific conductivity of the fiber were increased through electroless plating time. The temperature of nickel plating bath was very effective to enhance the nickel deposition rate.

• 한국분말재료학회지
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• 제22권6호
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• pp.391-395
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• 2015

We report on the successful fabrication of ZnO nanorod (NR)/polystyrene (PS) nanosphere hybrid nanostructure by combining drop coating and hydrothermal methods. Especially, by adopting an atomic layer deposition method for seed layer formation, very uniform ZnO NR structure is grown on the complicated PS surfaces. By using zinc nitrate hexahydrate $[Zn(NO_3)_2{\cdot}6H_2O]$ and hexamine $[(CH_2)_6N_4]$ as sources for Zn and O in hydrothermal process, hexagonal shaped single crystal ZnO NRs are synthesized without dissolution of PS in hydrothermal solution. X-ray diffraction results show that the ZnO NRs are grown along c-axis with single crystalline structure and there is no trace of impurities or unintentionally formed intermetallic compounds. Photoluminescence spectrum measured at room temperature for the ZnO NRs on flat Si and PS show typical two emission bands, which are corresponding to the band-edge and deep level emissions in ZnO crystal. Based on these structural and optical investigations, we confirm that the ZnO NRs can be grown well even on the complicated PS surface morphology to form the chestnut-shaped hybrid nanostructures for the energy generation and storage applications.