• Title/Summary/Keyword: Vacant Ho

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Hydroacylation of 1,5-Hexadiene through C-H Bond Activation (탄소-수소 결합 활성을 이용한 1,5-헥사디엔의 하이드로아실화반응 연구)

  • Jeon, Cheol Ho;Han, Jong Su;Kim, Seon Il
    • Journal of the Korean Chemical Society
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    • v.38 no.11
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    • pp.833-840
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    • 1994
  • 8-Quinolinecarboxaldehyde (1) reacted with 1,5-hexadiene (2) in THF under Wilkinson's catalyst(3) and $AgBF_4(8)$ to give a mixture of 8-quinolinyl 5-hexenyl ketone (4) and 8-quinolinyl 5-hexen-2-yl ketone (9) at initial reaction stage. The reason for the formation of the branched alkenyl ketone 9 is supposed to be that the vacant coordination site, generated from Wilkinson's catalyst and $AgBF_4(8)$, makes it possible to form the 5.5 membered ring metallacycle intermediate. The higher the concentration of $AgBF_4(8)$ was used, the greater the ratio of 9 to 4 was observed. Longer reaction time and high temperature induced isomerization of 9 and 4 to 10 and 5. Especially the high reaction temperature increased the possibility of cyclization of the 5-hexenyl metal intermediate to give 8-quinolinyl cyclopentylmethyl ketone (11).

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Mitigation of Membrane Biofouling in MBR Using a Cellulolytic Bacterium, Undibacterium sp. DM-1, Isolated from Activated Sludge

  • Nahm, Chang Hyun;Lee, Seonki;Lee, Sang Hyun;Lee, Kibaek;Lee, Jaewoo;Kwon, Hyeokpil;Choo, Kwang-Ho;Lee, Jung-Kee;Jang, Jae Young;Lee, Chung-Hak;Park, Pyung-Kyu
    • Journal of Microbiology and Biotechnology
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    • v.27 no.3
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    • pp.573-583
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    • 2017
  • Biofilm formation on the membrane surface results in the loss of permeability in membrane bioreactors (MBRs) for wastewater treatment. Studies have revealed that cellulose is not only produced by a number of bacterial species but also plays a key role during formation of their biofilm. Hence, in this study, cellulase was introduced to a MBR as a cellulose-induced biofilm control strategy. For practical application of cellulase to MBR, a cellulolytic (i.e., cellulase-producing) bacterium, Undibacterium sp. DM-1, was isolated from a lab-scale MBR for wastewater treatment. Prior to its application to MBR, it was confirmed that the cell-free supernatant of DM-1 was capable of inhibiting biofilm formation and of detaching the mature biofilm of activated sludge and cellulose-producing bacteria. This suggested that cellulase could be an effective anti-biofouling agent for MBRs used in wastewater treatment. Undibacterium sp. DM-1-entrapping beads (i.e., cellulolytic-beads) were applied to a continuous MBR to mitigate membrane biofouling 2.2-fold, compared with an MBR with vacant-beads as a control. Subsequent analysis of the cellulose content in the biofilm formed on the membrane surface revealed that this mitigation was associated with an approximately 30% reduction in cellulose by cellulolytic-beads in MBR.

Influence of Annealing Temperature on Structural and Thermoelectrical Properties of Bismuth-Telluride-Selenide Ternary Compound Thin Film

  • Kim, Youngmoon;Choi, Hyejin;Kim, Taehyeon;Cho, Mann-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.304.2-304.2
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    • 2014
  • Chalcogenides (Te,Se) and pnictogens(Bi,Sb) materials have been widely investigated as thermoelectric materials. Especially, Bi2Te3 (Bismuth telluride) compound thermoelectric materials in thin film and nanowires are known to have the highest thermoelectric figure of merit ZT at room temperature. Currently, the thermoelectric material research is mostly driven in two directions: (1) enhancing the Seebeck coefficient, electrical conductivity using quantum confinement effects and (2) decreasing thermal conductivity using phonon scattering effect. Herein we demonstrated influence of annealing temperature on structural and thermoelectrical properties of Bismuth-telluride-selenide ternary compound thin film. Te-rich Bismuth-telluride-selenide ternary compound thin film prepared co-deposited by thermal evaporation techniques. After annealing treatment, co-deposited thin film was transformed amorphous phase to Bi2Te3-Bi2Te2Se1 polycrystalline thin film. In the experiment, to investigate the structural and thermoelectric characteristics of Bi2Te3-i2Te2Se1 films, we measured Rutherford Backscattering spectrometry (RBS), X-ray diffraction (XRD), Raman spectroscopy, Scanning eletron microscopy (SEM), Transmission electron microscopy (TEM), Seebeck coefficient measurement and Hall measurement. After annealing treatment, electrical conductivity and Seebeck coefficient was increased by defect states dominated by selenium vacant sites. These charged selenium vacancies behave as electron donors, resulting in carrier concentration was increased. Moreover, Thermal conductivity was significantly decreased because phonon scattering was enhanced through the grain boundary in Bi2Te3-Bi2Te2Se1 polycrystalline compound. As a result, The enhancement of thermoelectric figure-of-merit could be obtained by optimal annealing treatment.

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A Study on the Ordering of Na ions in N $a_x$W $O_3$(0.5$\leq$TEX>$\chi$$\leq$1.0) (N $a_x$W $O_3$(0.5$\leq$TEX>$\chi$$\leq$1.0)의 Na ion의 규칙화에 관한 연구)

  • Na, Jong-Chul;Nahm, Sahn;Byun, Jae-Dong;Kim, Myong-Ho;Lee, Hwack-Joo;Ryu, Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.49-53
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    • 1996
  • Crystal structures of N $a_{x}$W $O_3$(0.5$\leq$x$\leq$1.0) were investigated. Transmission electron microscopy (TEM) studies indicate that there is an ordering of sodium ions when x=0.75. The direction of ordering is [110] and the wavelength of ordering is twice of the interplanar distance of (110) plane. It has been confirmed that a superlattice containing eight N $a_{0.75}$W $O_3$is the unit cell of ordered structure. In this unit cell, Na sites at (100) and ($\frac{1}{2}$$\frac{1}{2}$$\frac{1}{2}$) are vacant. The ordered phase was preserved after the annealing at $600^{\circ}C$ in the air. In reduced N $a_{x}$W $O_3$with x=0.5 and 1.0, extra phases were found to coexist with the partially ordered perovskite phase. After annealing at $600^{\circ}C$, theses phases were transformed into the phases found in calcined specimens.ens.s.

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Geomagnetic Anomalies by Underground Fracture Zones and Vacant Spaces (파쇄대와 지하의 빈 공간에 의한 지자기이상)

  • Lee, Moon-Ho
    • Journal of the Korean Magnetics Society
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    • v.20 no.2
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    • pp.52-60
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    • 2010
  • The changes of magnetic flux density distribution and the degree of magnetic anomaly on the ground surface by underground fracture zones and empty spaces had been investigated through the variations of the measuring heights. The magnetic flux density distributions were monitored for the ground surfaces of fracture zones, empty spaces and tunnels by fluxgate-type magnetometer. The fracture zones showed the magnetic anomaly with (+) and (-) peak-pairs in the magnetic flux distribution measured at 0.15 m height from the ground surface, and this anomaly disappeared at the height of 1.15 m. The underground empty spaces and tunnels showed the decrease of magnetic flux densities, where the degree of this density decrease diminished with the increase of the underground depth. And, the existence and size of underground empty spaces, such as tunnels and sink holes, could be monitored by the phenomena of this decreasing flux density.

Effects of Solvent Viscosity on Conformational Dynamics of Heme-pocket in Myoglobin and Hemoglobin

  • Kim, Seong-Heun;Lim, Man-Ho
    • Bulletin of the Korean Chemical Society
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    • v.27 no.11
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    • pp.1825-1831
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    • 2006
  • The influence of solvent viscosity on conformational dynamics of the heme-pocket, a small vacant site near the binding site of myoglobin (Mb) and hemoglobin (Hb), and playing a functionally important role by serving as a station in ligand binding and escape, was studied by probing time-resolved vibrational spectra of CO photodissociated from MbCO and HbCO in $D_2O$, 75 wt% glycerol/$D_2O$, and trehalose at 283 K. Two absorption bands ($B_1$ and $B_2$) of the sample in viscous solvents, arising from CO in the heme pocket, are very similar to those in $D_2O$. Two bands in Mb and Hb under all three solvents exhibit very similar nonexponential spectral evolution ($B_1$ band; blue shifting and broadening, $B_2$ band; narrowing with a negligible shifting), suggesting that in the present experimental time window of 100 ps, the extents of the spectral shift and narrowing is much influenced neither by the viscosity of solvent nor by the quaternary contact of Hb. Spectral evolution can be described by a biexponential function with a fast universal time constant of 0.52 ps and a slow time constant ranging from 13 to 32 ps. For both proteins in all three solvents majority of spectral evolution occurs with the fast universal time constant. The magnitude of the slow rate in the spectral shift of B1 band decreases with increasing solvent viscosity, indicating that it is influenced by global conformational change which is retarded in viscous solvent, thereby serve as a reporter of global conformational change of heme proteins after deligation.

Experiment Study on the Flexural-Axial Capacity of Steel-Concrete Composite Column composed of Non-Compact Section (비조밀단면을 가진 SC 합성 기둥의 휨-압축 내력에 관한 실험 연구)

  • Oh, Myoung Ho;Kim, Bum Rae;Kim, Myeong Han;Kim, Dae Joong;Kim, Sang Dae
    • Journal of Korean Society of Steel Construction
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    • v.17 no.4 s.77
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    • pp.431-438
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    • 2005
  • A steel-concrete composite column is a recently developed composite system in which the two opposite flanges of the H-shape section are connected by welded links, and the vacant space enclosed by the flanges, web, and links is filled with concrete. Previous experiments on the SC composite column were performed to evaluate its compression and bending and shear strengths, respectively, and they showed fairly good results. In addition to thesestudies, it may be necessary to evaluate the flexural-axial capacity of an SC composite column, because itscolumn members are generally subjected to axial force and bending moment at the same time. In this study, the bending strength of an SC composite column subjected to axial compression force was investigated experimentally. The results of the study showed that the AISC-LRFD provisions representedexcessively low values compared with those of the ACI, Eurocode-4, and Japan Code provisions. The Eurocode-4 provisions represented reasonable evaluations of the strength of the SC composite column composed of a non-compact section.

Study on High Degree of Efficiency Chemical Reactor for Air Purification Using the Glow Discharge (글로우 방전을 이용한 고효율 공기 정화용 화학 반응기의 특성관찰에 관한 연구)

  • Kim, Gi-Ho;Bu, Min-Ho;Lee, Sang-Cheon
    • Journal of the Korean Chemical Society
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    • v.50 no.1
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    • pp.14-22
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    • 2006
  • the basic model of chemical reactor using glow discharge, we used cathode discharge cell with vacant cavity in the middle. Currently glow discharge is widely studied as a radiation source or atomization device in atomic spectroscopy and remarkable technological achievements are made through the graft with other analysis devices such as microanalysis and steel analysis.1 Additionally, as the characteristics of basic glow discharge and radiation have been reviewed many times, those results could be used in this experiment.2-3 In 1993, an article regarding the treatment of poisonous gas in the air using low temperature plasma was published. According to this article, if DC Glow Discharge is used under continuous atmospheric flow, poisonous gases such as SO2 and NO can be removed.4 Based on those findings, we designed highly efficient reactor where stable air plasma is composed and all air flow pass the negative glow area passing through the tube. It was observed that the cathode tube type glow discharge developed in this study would be economical, easy to use and could be used as radiation source as well.

Forecasting Vacant Technology of Patent Analysis System using Self Organizing Map and Matrix Analysis (자기조직화 지도와 매트릭스분석을 이용한 특허분석시스템의 공백기술 예측)

  • Jun, Sung-Hae;Park, Sang-Sung;Shin, Young-Geun;Jang, Dong-Sik;Chung, Ho-Seok
    • The Journal of the Korea Contents Association
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    • v.10 no.2
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    • pp.462-480
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    • 2010
  • Patent analysis is the extracting knowledge which is needed for the company's research and development strategy through accumulated worldwide patent database. In order to set the future direction of corresponding technology which is scheduled to be developed, the technology trends and deployment processes are identified by analyzing results of present patent applications. The patent analysis provides the required results for analyzing present patent applications. In this paper, we will carry out technology classification for related patent analysis methods and systems. Moreover we will investigate and analyze related domestic patents, U.S. patents and IEEE papers. Due to the characteristics of technology sector, not only patents are applied but also research papers are released actively about patent analysis system. We will analyze patents according to the technology classification by using the final searching results which come from the selected search words in this study. To find necessary niche technology which is needed for patent analysis system, matrix analysis was performed to all of valid patents and papers. Identifying the technology development trends of registered patent analysis systems, and presenting the future direction of technology development which is related to patent analysis system. To figure out the technology which is developed relatively weak based on domestic patents, U.S patent and research papers by analyzing the valid patents and papers with statistical test and self-organizing map quantitatively. Then, presenting the necessity of this technology development.

A Study on the Method of Rural Rental Housing Management by Analysis of Rural-Fishing New Town Rental Housing (농어촌 뉴타운 공공임대주택 관리 분석을 통한 농촌형 임대주택 관리방안에 관한 연구)

  • Park, Mi-Lan;Park, Heon-Choon;Kim, Jin-Wook;Ryoo, Yeon-Su
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.3
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    • pp.55-62
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    • 2015
  • Recently as return farmers has been increased rapidly, the introduction of a system of rental housing is being considerated in order to induce regional fixation. It was examined organizational management, business scope of rural type rental housing, management role, through the analysis about the management realities of the business of similar form Rural-Fishing New Town project. Jangseonggun and Hwasungun have maneged rental housing 280ho in Rural-Fishing New Town project. It is large village among Rural Rental Housing. And these counties have organized the complex on a large scale among the rental housing. Local governments have managed and operated directly, also these governments have two different methods for the co-management, and the way of making payment. Rental housing management services are divided into rental management, housing management, tenant management. Rental management services such as residents of recruitment, tenants and retreat, rent collection and the storage, management and leasing promotion of the cantilever, surveys of residents. Housing management services such as check of various facilities, maintenance and maintenance work, security and cleaning and daily facility management. Tenant management is life management in connection with housing welfare. In the rural type of rental housing, there are few cases to operate a management office. It is often supplied by rental housing to buy a house or vacant land within the existing village. In this case, by utilizing community facilities within the existing village instead of establishment of extra facilities,It doesn't need to make payment for maintenance fee. In the smaller complex than No. 20, it is self-managed by the tenants in order to reduce the administrative costs and specify the necessary municipal manager. Organization form can be maneged directly from local governments and part of for the management of the building can be employed a mixed management system to delegate management to private organizations such as non-profit organizations or neighborhood association. Tenant management helps people who move in a rental house live on stable circumstance in there area by connection with the program of life support.