• Title/Summary/Keyword: Direct seed

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Agronomic Practces on Intensive Pasture Establishment (집약초지의 조성기술)

  • 김동암;조무환
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.2 no.2
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    • pp.1-15
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    • 1981
  • In reviewing of the literature concerning agronomic practices on intensive pasture establishment the following suggestions were made : (1) The seedbed preparation should be involved physical manipulation of the soil tilth and consolidation of the soil by harrows and heavy roller. (2) In terms of methods of sowing, drilling favours the first and broadcasting the second however, the apparent superiority of band sowing over the above conventional methods is to reduce the direct toxic chemical effects from fertilizers to germinating seeds. (3) The most satisfactory seeding depth for grasses and legumes is commonly agreed to be approximately 1.3cm and seeding depth greater than 2.5cm seems to be generally detrimental. (4) Autumn and spring are most common sowing periods for grasses and legumes, however, early autumn being the most generally favoured, particularly in areas not subject to severe winter kill. (5) Select nurse crop species or cultivars which make Bess demands on light, nutrients and water, and lower seed rates should be used. (6) Seeding mixtures should be simple rather than complex and aggressive species should be included to a minor extent.

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Micro patterning of conductor line by laser induced forward transfer(LIFT) (LIFT 방법에 의한 전도성 미세 패터닝 공정 연구)

  • 이제훈;한유희
    • Laser Solutions
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    • v.2 no.3
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    • pp.52-61
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    • 1999
  • The laser induced forward transfer(LIFT) technique employs a pulsed laser to transfer parts of a thin metal film from an optically transparent target onto an arbitrary substrate in close proximity to the metal film on the target. In this work, a two-step method, the combination of LIFT process, in which a Au film deposited on the $Al_2$O$_3$ substrate by Nd:YAG laser and subsequent Au electroless metal plating on the by LIFT process generated Au seed, was presented. The influence of laser parameters, wavelength, laser power, film thickness and overlap ratio of pulse tracks, on the shapes of deposit and conductor line after electroless plating is experimentally studied. As a results, the threshold power densities for ablation, deposition and metallization were determined and comparison of threshold value between the wave length 1064nm and the second harmonic generated 532nm. In odor to determine a possible application in the electronic industry, a smallest conduct spot size, line width and isolated line space were generated.

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CHARACTERISTICS OF BIOHYDROGEN PRODUCTION AND MICROBIAL COMMUNITY AS A FUNCTION OF SUBSTRATE CONCENTRATION

  • Youn, Jong-Ho;Shin, Hang-Sik
    • Environmental Engineering Research
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    • v.10 no.1
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    • pp.7-14
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    • 2005
  • The feasibility of hydrogen production with a raw seed sludge through direct acclimation of feedstock was investigated at acidogenic stage, and methane was harvested at followed methanogenic stage in an anaerobic two-stage process. Hydrogen content was higher than 57% at all tested organic loading rates (OLRs) and the yield of hydrogen ranged from 1.5 to 2.4 mol H2/mol hexose consumed and peaked at 6 gVSl-1day-1. Normal butyrate and acetate were main volatile fatty acids (VFAs), whereas the concentration of propionate was insignificant. The hydrogen-producing bacteria, Clostridium thermosaccharolyticum, was detected with strong intensity at all tested organic loading rates (OLRs) by denaturing gradient gel electrophoresis (DGGE) of the polymerase chain reaction (PCR) analysis. From COD balance in the process, the fraction of the feed-COD converted to the hydrogen-COD at acidogenic stage ranged from 7.9% to 9.3% and peaked at 6 gVSl-1day-1, whereas the fraction of feed-COD converted to the methane-COD at methanogenic stage ranged from 66.2% to 72.3% and peaked at 3 gVSl-1day-1.

The Impact of ODA·FDI·Trade on the Africa Economic Growth : Evidence from Senegal

  • Choi, Chang Hwan
    • International Area Studies Review
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    • v.20 no.1
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    • pp.127-146
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    • 2016
  • This paper investigates that the Granger-causality between ODA FDI Trade, and economic growth in Senegal over the last 50 years and ODA, FDI, Trade have a impact on the Senegal's economic growth using the Vector Error Correction Model. The empirical results do confirm a directional causality between the variables considered. It also showed that an increase of ODA in the Senegal has positive effect on GDP growth and FDI, which are important factors of economic growth for poor country like Senegal. Underdeveloped nation has been suffered from insufficient savings or capital for economic growth; therefore, developed nations have to provide enough ODA to supply initial capital formation for growth, so-called, seed money. In a nutshell, ODA as a priming the pump is required and expanded continuously for Africa country's economic growth.

Studies on Partial Revegetation of Rock Cut-Slope by Direct Seeding of Woody Species Seeds (수목종자 직파에 의한 암반절개사면 부분녹화)

  • Hong, Sung-Gak;Kim, Jong-Jin;Lee, Duck-Soo;Lee, Ki-Cheol;Yoon, Teok-Seong
    • Korean Journal of Environmental Agriculture
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    • v.18 no.3
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    • pp.265-271
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    • 1999
  • The direct seeding of seeds or the pellets of three native tree species (Pinus densiflora, Parthenocissus tricuspidata and Rhus chinensis) was tried on the rock cut-slope revegetation bed established by construction of mechanical excavation or erosion break with artificially enriched soil medium. The seed $pellet(1{\sim}2\;cubic\;cm)$ made by coating seeds(treated with proper previous pregermination treatments) with the mixture of peatmoss, clay, chemical absorbant(3.5:1.0:0.2, v/v) showed about twice better percent germination than the control seeds. The percent germination and the survival rate of the germinated seedlings were higher in the spring direct seeding than the summer or the fall. The soil medium containing the compost showed extremely low percent $germination(0{\sim}3%)$ which presumably attributed to the compost inducing damping-off disease. The survival rates were affected mainly by shading of natural herbaceous vegetation invading from outside to the revegetation bed. The planting of two year old container seedlings of P. densiflora and P. tricuspidata on August 2, 1998 was successful indicating that it could be an alternative revegetation method in case the summer direct seeding is unfavorable.

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Consequence of Floral Herbivory in Vicia cracca (Leguminosae)

  • Gang, Hye-Sun
    • Animal cells and systems
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    • v.2 no.1
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    • pp.55-63
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    • 1998
  • The effects of inflorescence herbivory and flowering time on plant architecture and reproductive yields were examined with a perennial herbacious species, Vicia cracca, occurring in Natick, Massachusetts, USA. Natural herbivory on inflorescences was observed among the total of 157 plants during a growing season. Vegetative and reproductive characters were measured in the field as well as in the lab depending on the characters. Approximately 64% of the plants were subjected to herbivory on inflorescences. Plants were classified into three groups; unbrowsed plants, partially browsed, and totally browsed plants, according to the level of herbivory on inflorescences of each plant. Plants were also categorized by their flowering time such as early vs late flowering plants. Herbivores tended to favor inflorescences on rather small plants, resulting in a pattern of totally contact or partially intact inflorescences on taller plants. The mean number of stems, which was assumed to be a direct result of severe herbivory in this population, differed among herbivory groups. There also was a tendency that plants flowering late in the season had more nodes with more leaves, suggesting that herbivory on stem tips early in the season before flowering might have induced growth of side branches or branchlets along the main stems. Comparison between unbrowsed and partially browsed plants showed that the latter compensated for browsing in terms of numbers of inflorescences, fruits, seeds and seed size (weight), though they did not compensate in flower number. The probability of fruit production (presence vs absence of fruits) and seed weight declined toward the end of the season. These results suggest that resources are deficient at the end of the season. Almost complete reproductive failure in totally browsed plants is attributed to the destruction of inflorescence display and the disadvantage of small vegetative size of those plants. After all, in this population, a moderate level of herbivory on inflorescences did not reduce the maternal fitness of the plants. However, severe herbivory on inflorescences resulted in antagonistic interactions between plants and herbivores.

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Determination of Resveratrol Content in Grapes and Wines (포도 및 포도주 함유 Resveratrol의 정량 분석)

  • Kim, Heon-Woong;Chu, Sang-Mi;Lee, Dong-Jin
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.spc1
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    • pp.259-263
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    • 2006
  • A direct HPLC method was used to analyze determination of resveratrol in grapes and wines. Content of resveratrol in different parts of 13 grape cultivars and 13 wines were quantified. The average total resveratrol content was $143.5{\mu}g/g$. Resveratrol contents in the skin, fruit, seed and fruit stem were distributed range of $0.9{\sim}104.8{\mu}g/g,\;0.1{\sim}0.5{\mu}g/g\;1.7{\sim}173.9{\mu}g/g\;2.9{\sim}247.4{\mu}g/g$, respectively. Resveratrol contents in 13 wines were distributed range of $253.3{\sim}11,271.6{\mu}g/g$.

Interconnection Processes Using Cu Vias for MEMS Sensor Packages (Cu 비아를 이용한 MEMS 센서의 스택 패키지용 Interconnection 공정)

  • Park, S.H.;Oh, T.S.;Eum, Y.S.;Moon, J.T.
    • Journal of the Microelectronics and Packaging Society
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    • v.14 no.4
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    • pp.63-69
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    • 2007
  • We investigated interconnection processes using Cu vias for MEMS sensor packages. Ag paste layer was formed on a glass substrate and used as a seed layer for electrodeposition of Cu vias after bonding a Si substrate with through-via holes. With applying electrodeposition current densities of $20mA/cm^2\;and\;30mA/cm^2$ at direct current mode to the Ag paste seed-layer, Cu vias of $200{\mu}m$ diameter and $350{\mu}m$ depth were formed successfully without electrodeposition defects. Interconnection processes for MEMS sensor packages could be accomplished with Ti/Cu/Ti line formation, Au pad electrodeposition, Sn solder electrodeposition and reflow process on the Si substrate where Cu vias were formed by Cu electrodeposition into through-via holes.

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QTL mapping of low-temperature germinability and identification of qLTG1 candidate genes in rice

  • Kim, Sun Ha;Shim, Kyu-Chan;Lee, Hyun-Sook;Le, Anh Quynh;Ahn, Sang-Nag
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.116-116
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    • 2017
  • Low-temperature is one of the environmental stress factors that affect plant growth and development and consequently limit crop productivity. The control of seed germination under low-temperature is organized by many genes which are called quantitative trait loci (QTLs). High germination rate for low-temperature is an important factor of growing rice. Previously, we identified a major QTL controlling low-temperature germinability in rice using 96 introgression lines (ILs) derived from a cross between Oryza rufipogon (Rufi) and the Korean japonica cultivar, 'Hwaseongbyeo (HS)'. A $BC_3F_7$ line (TR5) showed better low-temperature germinability than its recurrent parent. TR5 was crossed with HS to develop a segregating F2:3 populations for the target QTL. Six SSR markers polymorphic between HS and Rufi were used to screen and fine map the qLTG1. The qLTG1 on chromosome 1, which accounted for 55.5% of the total phenotypic variation, confirmed that Rufi allele enhanced the low-temperature germinability. Intervals between markers CRM16 and CRM15, four candidate genes were identified. The identified candidate genes, which are encoded by a protein of unknown function, showed their direct involvement on seed germination at low-temperature. To identify genes targeted by qLTG1, we investigated the expression profiles of these candidate genes and germination behavior of qLTG1 under different stress conditions and compared to HS, Rufi, and TR5 at $13{\pm}2^{\circ}C$ for 3 days after incubation. Furthermore, transgenic rice plants will also be developed to conduct a detailed investigation on low-temperature germinability. Hence, the QTL for low-temperature germinability would be useful in rice breeding programs especially in the development of lines possessing low-temperature germinability.

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광전자소자의 응용을 위한 산화아연 나노로드의 패터닝 형성방법

  • Go, Yeong-Hwan;Yu, Jae-Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.97-97
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    • 2011
  • 산화아연 (ZnO)은 넓은 에너지 밴드갭 (~3.37 eV), 큰 엑시톤 결합 에너지 (~60 meV) 그리고 높은 전자 이동도 (bulk~300 $cm^2Vs^{-1}$, single nanowire~1000 $cm^2Vs^{-1}$)를 갖고 있어, 광전자 소자 및 반도체소자 응용에 매우 널리 사용되고 있다. 특히, 산화아연 나노로드(ZnO nanorod)는 1차원 나노구조로써 더욱 향상된 전자 이동도와 캐리어의 direct path way를 제공하여 차세대 광전자소자 및 태양광 소자의 응용에 대한 연구가 매우 활발하게 이루어지고 있다. 한편, 이러한 산화아연 나노로드를 성장시키기 위하여 VLS (vapor-liquid-solid), 졸-겔 공정(sol-gel process), 수열합성(hydrothermal synthesis), 전기증착(electrodeposition)등 다양한 방법이 보고되었지만, 이러한 산화아연 나노로드의 성장방법은 실제적인 소자응용을 위한 패터닝 형성에 대하여 제약을 받는 문제점이 있다. 이들 중에서 수열합성법과 전극증착법은 ZnO 또는 AZO (Al doped ZnO) seed 층 표면과 성장용액의 화학반응에 의해서 선택적으로 산화아연 나노로드를 성장시킬 수 있다. 이에 본 연구에서는, 광전자소자의 응용을 위한 간단한 패터닝 공정을 위해, 산화인듐주석(ITO) 박막이 증착된 유리기판(glass substrate)위에 수열합성법과 전극증착법을 이용하여 산화아연 나노로드를 선택적으로 성장시켰다. 실험을 위해, ITO glass 위에 RF magnetron 스퍼터를 사용하여 AZO seed 층을 metal shadow mask를 이용하여 패터닝을 형성한 후, 질산아연과 헥사메틸렌테트라아민으로 혼합된 용액에 $85^{\circ}C$ 온도를 유지하여, 패터닝이 형성된 샘플에 전압을 인가하여 성장시켰다. 나노구조 분석을 위해, 전계주사현미경을 이용하여 수열합성법과 전기증착법에 의한 패터닝된 산화아연 나노로드를 비교하여 관찰하였다.

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