• Title/Summary/Keyword: fixing

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Effects of Rice Straw Application on the Biological Nitrogen Fixation of Paddy Fields. -I. Effects of Application Method of Rice Straw on the Nitrogen Fixing Activity (논 토양(土壤)의 생물적(生物的) 질소고정(窒素固定)에 미치는 볏짚 시용효과(施用効果) -I. 볏짚 시용방법(施用方法)이 질소고정활성(窒素固定活性)에 미치는 영향(影響))

  • Yoo, Ick-Dong;Matsuguchi, Tatsuhiko
    • Korean Journal of Soil Science and Fertilizer
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    • v.16 no.1
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    • pp.77-83
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    • 1983
  • Effects of rice straw application (particularly application method; surface placement and deep placement) on the biological nitrogen fixing activity of paddy fields and on the growth of rice plant have been investigated by the lysimeter experiment with Aragawa alluvial soil and Tochigi ando soil. 1. Nitrogen fixing activity of plow layer (0~1cm) was increased by the rice straw application, notably by the phototrophs, both deep placement and surface placement, between 1 and 2 months of initial growth stage of rice plant. 2. Surface placement method stimulated the nitrogen fixing activity more significantly them the deep placement method, and also showed good effects on the growth of rice plant. 3. The increased of effect on the nitrogen fixing activity of surface placed area was found to be originated from the applied rice straw and its neigh bouring area. 4. Nitrogen fixing activity of surface placed rice straw was rather promoted by the application of herbicides (2, 4, 6-arichlorophenyl ether) than the non-applicated plot.

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A Study on the Fixing Effects of Several Fixatives on Oral Epithelial Cell (수종 고정액의 상피세포에 대한 고정효과에 관한 연구)

  • Hong, Ran
    • Journal of Oral Medicine and Pain
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    • v.3 no.1
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    • pp.23-27
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    • 1977
  • The author thought that the results of cytologic tests could be changed according to the fixative methods. So the author has studied several methods of fixing exfolaiative cells collected from normal adult cheek mucosa with a solution of equal parts of ether and 95% ethylalcohol, 95 ethylalcohol and Isoprophyl alcohol, and compared the results with each other. The results were as follows : The effects of fixation, and staining efficiency of nucleus and protoplasm are similar in each method, but the staining efficiency of cytoplasm and the conversation of cytoplasmic membrane were best in 95% ethylalcohol.

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A Study on Development of Compressive End-Bracket for External Prestressing Method (외부강선 보강을 위한 압축형 단부 브라켓의 개발 연구)

  • 한만엽;정문연
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.697-700
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    • 1999
  • Strengthening existing structure using the exterior steel wire is utilized because of their high adaptability and strengthening efficiency. In the practical aspect, the fixing methods, which are generally adopted have caused problems. A new method is not easily designed because of the weak points, a limit of tension stress, and complex transmit processes. To make up for the weak points in the current fixing method, tensile end bracket similar to a supporting plate has been developed, but the tensile end bracket was relatively big because of increasing length welded between the end plate and the resisting plate.

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Studies on the Nitrogen-fixing Symbiosis in Actinorhizal Plants I. Survey of the actinorhizal root nodules and collection the root nodules (목본식물에 있어서 질소고정 공생관계 (Actinorhizal symbiosis)에 관한 연구)

  • 안정선
    • Journal of Plant Biology
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    • v.29 no.2
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    • pp.109-115
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    • 1986
  • Actinorhizal plants being capable of fixing atmospheric nitrogen in symbiotic association with Frankia were surveyed for their root nodules, and the root nodules were collected for further studies. Three species of Alnus and Elaeagnus (A. hirsuta, a. firma, A. japonica; E. glabra, e. umbellata, E. macrophylla) and one species of Myrica (M. rubura) were confirmed to bear the root nodules of typical external shape. Morphological studies using light microscope and scanning electron microscope revealed the presence of vesicle clusters in the cortex region of the root. Two tentative endophyte colonies were isolated from the root nodule of A. hirsuta.

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Design of WDM holographic demultiplexer using a High-Low thermal fixing (High-Low 열정착 기법을 이용한 WDM 홀로그래픽 역다중화기의 설계)

  • Park, Jung-Ho;Jeon, Seok-Hee;Jung, Sang-Hyuk;Jung, Jae-Won;Lee, Kwon-Yeon;Kim, Nam
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.110-111
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    • 2003
  • Holographic demultiplexer for the wavelength-division multiplexing optical communication system is proposed, and some experimental results are presented. To record the multiple holographic grating channels in the Fe:LiNbO$_3$ crystal, angular multiplexing and High-Low thermal fixing method are used.

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Enrichment of $CO_2$-Fixing Bacteria in Cylinder-Type Electrochemical Bioreactor with Built-In Anode Compartment

  • Jeon, Bo-Young;Jung, Il-Lae;Park, Doo-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.21 no.6
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    • pp.590-598
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    • 2011
  • Bacterial assimilation of $CO_2$ into stable biomolecules using electrochemical reducing power may be an effective method to reduce atmospheric $CO_2$ without fossil fuel combustion. For the enrichment of the $CO_2$-fixing bacteria using electrochemical reducing power as an energy source, a cylinder-type electrochemical bioreactor with a built-in anode compartment was developed. A graphite felt cathode modified with neutral red (NR-graphite cathode) was used as a solid electron mediator to induce bacterial cells to fix $CO_2$ using electrochemical reducing power. Bacterial $CO_2$ consumption was calculated based on the variation in the ratio of $CO_2$ to $N_2$ in the gas reservoir. $CO_2$ consumed by the bacteria grown in the electrochemical bioreactor (2,000 ml) reached a maximum of approximately 1,500 ml per week. Time-coursed variations in the bacterial community grown with the electrochemical reducing power and $CO_2$ in the mineral-based medium were analyzed via temperature gradient gel electrophoresis (TGGE) of the 16S rDNA variable region. Some of the bacterial community constituents noted at the initial time disappeared completely, but some of them observed as DNA signs at the initial time were clearly enriched in the electrochemical bioreactor during 24 weeks of incubation. Finally, Alcaligenes sp. and Achromobacter sp., which are capable of autotrophically fixing $CO_2$, were enriched to major constituents of the bacterial community in the electrochemical bioreactor.

Contents Change Aspect on Fixing Process of Local Festival Case of the Yeongsangang Culture Festival in Naju (지역축제 정착화 과정에서의 콘텐츠 변화양상 -나주 영산강문화축제 사례를 중심으로-)

  • Lim, Eun-Mi
    • The Journal of the Korea Contents Association
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    • v.9 no.12
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    • pp.438-447
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    • 2009
  • Korean local festival had grown rapidly quantitatively and qualitatively for past 10 year. And also problems of domestic local festival had been indicated much by specialists and researchers who plan festival. But most precedent researches are stopping in problem presentation that is based in one point of time. In the meantime, most the very best culture tourism festivals are meeting fixing step through trial and error in historic process more than 10 years. It is important to solve fundamental problem that understand process so much. This research analyzed festival contents change aspect on fixing process as local representative festival by time-series analys, Yeongsangang culture festival to example. By the result, the biggest problem is that unclearness of festival subject by wide festival theme establishment is connected by losing festival's identity.

Optimal Growth Conditions for the Two Euryhaline Cyanobacterial Clones, Anabaena sp. CB-MAL21 and CB-MAL22 Isolated from Mankyeong Estuary, Korea

  • Kim, Young-Geel;Myung, Geum-Og;Yih, Won-Ho;Shin, Yoon-Keun
    • ALGAE
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    • v.19 no.2
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    • pp.145-148
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    • 2004
  • As a result of the 2-year monthly monitoring of the phytoplankton community at 3 stations in Mankyeong Estuary, Korea, we learned that cyan bacterial species of the genus Anabaena occurred at most sampling points with huge salinity differences (0.1-32.5 psu). We isolated several clones of Anabaena spp. from the monitoring stations, and screen out two euryhaline and nitrogen-fixing Anabaena clones, CB-MAL21 and CB-MAL22. The two clones were grown under various environmental gradients such as temperature (20, 30, 35 and 40$^{\circ}C$), salinity (0, 2, 5, 15 and 30psu), and $PO_4^{3-}$-P concentration (0, 1.6, 8.0, 40 and 200 ${\mu}M$M). Growth of CB-MAL21 and CB-MAL22 was measured by daily monitoring of chlorophyll fluorescence from each experimental culture for more than three serial transfers. Both the two experimental clones did not grow at 0psu. Maximal growth rates of the two clones were markedly reduced at lower $PO_4^{3-}$-P concentrations showing negligible growth at 0 and 1.6 ${\mu}M$M. However, growth of CB-MAL21 was not affected by low $NO_3^--$ concentration in culture media, showing the nitrogen-fixing ability. Maximum biomass yields of the two clones decreased dramatically at 35 and 40$^{\circ}C$. Optimal growth conditions for the two experimental clones were determined to be 20-30$^{\circ}C$, 40 ${\mu}M$M $PO_4^{3-}$-P, and wide salinity range from 5.0 to over 30psu. Best growth of CB-MAL21 was shown at (20$^{\circ}C$-15psu), which is less saline and cooler condition than those (i.e., 30$^{\circ}C$-30psu) for the best growth of CB-MAL22. The euryhaline and nitrogen-fixing CB-MAL21 strain thus can be a candidate laboratory culture for the future cyan bacterial marine biotechnology in temperate coastal waters.

Ammonium Production During the Nitrogen-Fixing Process by Wild Paenibacillus Strains and Cell-Free Extract Adsorbed on Nano $TiO_2$ Particles

  • Shokri, Dariush;Emtiazi, Giti
    • Journal of Microbiology and Biotechnology
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    • v.20 no.8
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    • pp.1251-1258
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    • 2010
  • During the nitrogen-fixing process, ammonia ($NH_3$) is incorporated into glutamate to yield glutamine and is generally not secreted. However, in this study, $NH_3$-excreting strains of nitrogen-fixing Paenibacillus were isolated from soil. The ammonium production by the Paenibacillus strains was assayed in different experiments (dry biomass, wet biomass, cell-free extract, and cell-free extract adsorbed on nano $TiO_2$ particles) inside an innovative bioreactor containing capsules of $N_2$ and $H_2$. In addition, the effects of different $N_2$ and $H_2$ treatments on the formation of $NH_3$ were assayed. The results showed that the dry biomass of the strains produced the most $NH_3$. The dry biomass of the Paenibacillus strain E produced the most $NH_3$ at 1.50, 0.34, and 0.27 ${\mu}M$ $NH_3$/mg biomass/h in the presence of $N_2$ + $H_2$, $N_2$, and $H_2$, respectively, indicating that a combined effluent of $N_2$ and $H_2$ was vital for $NH_3$ production. Notwithstanding, a cell-free extract (CFE) adsorbed on nano $TiO_2$ particles produced the most $NH_3$ and preserved the enzyme activities for a longer period of time, where the $NH_3$ production was 2.45 ${\mu}M$/mg CFE/h over 17 h. Therefore, the present study provides a new, simple, and inexpensive method of $NH_3$ production.

Position Fixing Accuracy of TDOA Direction Finding Method (TDOA 방위탐지방식의 위치표정 정확도)

  • Lim, Joong-Soo;Chae, Gyoo-Soo
    • Journal of Digital Convergence
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    • v.12 no.11
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    • pp.373-378
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    • 2014
  • The technology of direction finding is very important to make high position fixing accuracy. TDOA(time difference of arrival) direction finding technology is a high accuracy technology and is used in RF system from 1990. The principle of TDOA is to receive an emitter signal with two antennas, measure the time difference of received signal and then convert the time differences to azimuth angle. For high DF(direction finding) accuracy long basis line and high SNR at receiving system are needed. The DF accuracy and position fixing accuracy are simulated with different SNRs and antenna base lines. We obtain the DF accuracy of $0.51^{\circ}$ at $0^{\circ}$ incident azimuth angle in case of 50m base line and 40dB SNR.