• Title/Summary/Keyword: C3H

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Preparation and Structure of $Re(≡NC_6H_5)(DPPE)CI_3$, $[DPPE=Ph_2PCH_2CH_2PPh_2]$ ($Re(≡NC_6H_5)(DPPE)CI_3$화합물의 합성 및 구조)

  • 박병규;정건수
    • Korean Journal of Crystallography
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    • v.6 no.2
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    • pp.93-97
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    • 1995
  • Re(≡NC6H5)(PPh3)2CI3, I, reacted with, 1,2-bis(diphenylphosphino)ethane (DPPE) to give fac-Re(≡NC6H5)(DPPE)CI3, II. The product has been characterized by 1H-NMR, elemental analysis, and X-ray crystallography. II Crystalizes in the monoclinic space group Pc, with cell parameters a=11.083(3)Å, b=10.930(1)Å, c=14.081(2)Å, β=108.37(2)°, Z=2. Least-squares refinement of the structure led to a R(wR2)factor of 0.0254(0.0607) for 2888 unique reflections of I>2σ(I) and for 352 variables.

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Analysis of Nanostructural Deformation Behavior of Cement Clinker Substituting High-volume Fly ash by Pair Distribution Function (원자짝 분포 함수를 이용한 플라이애시를 대량 치환한 시멘트 클링커의 나노 구조 변형 거동 해석)

  • Jee, Hyeon-Seok;Park, Jae-Yeon;Bae, Sung-Chul
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.112-113
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    • 2019
  • Recently, supplementary cementitious materials such as blast-furnace slag, fly ash and silica fume have been widely used as substitutes for cementitious materials. In this study, the deformation behavior of compressive loading of C3S paste with 50% fly ash was analyzed by X-ray scattering data and pair distribution function analysis. The obtained results were compared with 131-day-old pure C3S paste. The Ca(OH)2 of the C3S-FA paste showed almost complete elastic behavior, consistent with the deformation behavior of the r-range of 20 to 40, and the C-S-H phase contributed to the range of PDF r-range of less than 20. In addition, C-S-H of C3S-FA showed greater deformation resistance than C3S paste.

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Preparation of Functional Beverage by Using Dandelion (Taraxacum mongolicum H.) Extracts and Its Functional Components (민들레(Taraxacum mongolicum H.) 추출액을 이용한 기능성 음료 개발 및 기능성 성분)

  • Song, Nho-Eul;Yoo, Hyang-Duk;Baik, Sang-Ho
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.6
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    • pp.733-741
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    • 2013
  • The objective of this study is to prepare functional beverages with dandelion (Taraxacum mongolicum H.) extracts. As a result of sensory evaluation, 10% water extracts of dandelion containing beverage, which was the highest value of overall preference, was chosen for further examinations. Moisture content of developed beverage was $99.6{\pm}0.5%$ and sugar content decreased from 0.8 to $0.7^{\circ}Brix$ whereas pH increased from 3.4 to 3.7 by addition of 10% dandelion extracts. Total phenolic and flavonoid contents of beverage were $295.8{\pm}5.8mg/L$ and $122.8{\pm}18.4mg/L$, respectively. The developed beverage showed higher DPPH radical scavenging activity of $98.2{\pm}0.6%$ than the beverage without extract. Moreover, concentration of silibinin in the T. mongolicum H. beverage was $0.3{\pm}0.04mg/L$.

Studies on antimicrobial agent produced by lactobacillus acidophilus (Lactobacillus acidophilus가 생산한 항균물질(抗菌物質)에 관한 연구(硏究))

  • Kim, Dong-shin
    • Korean Journal of Veterinary Research
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    • v.24 no.2
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    • pp.149-162
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    • 1984
  • The research was conducted(1) to confirm the agent(s) responsible for the antimicrobial activity contained in the fermented tomato juice with L. acidophilus(2) to extract and purify the antimicrobial agent(s)(3) to find the biological, physical and chemical properties of the agent(s). The following results were obtained and summarized as followings; 1. The agent responsible for the inhibitory activity was confirmed by both well assay method using fermented tomato juice with L. acidophilus and turbidimetric technique using the cell-free filtrate or neutralized filtrate of tomato acidohilus culture and found exerted antimicrobial agent other than lactic acid. 2. The procedures of purification : The isolation and purification of antimicrobial agent from the lyophilized acidophilus tomato culture were carried out by (1) methanol extraction (2) acetone extraction, (3) Sephadex G-50 gel filtration (4) paper chromatography and (5) thin layer chromatography. 3. The biological, physical and chemical properties of antimicrobial agent: The biological, physical, chemical properties of the purified antimicrobial agent were: (1) The antimicrobial activity was strong against test organisms; Bacillus subtilis(ATCC 6633), Escheichia coli(ATCC 25922), Staphylococcus aureus(ATCC 167), Pseudomonas fluorescens(KFCC 32394), Proteus vulgaris and Shigella dysenteriae. (2) The pH value of the agent was 2.0 and the inhibitory activity was lost when it was neutralized at 7.0 of pH and the agent was heat stable at $121^{\circ}C$ for 60 minutes. (3) The ultraviolet light absorption spectra of methanol-acetone extract and TLC fraction exhibited a maximum absorption at 260nm and 224nm respectively. (4) The most purified agent from TLC plate increased about 130-fold in activity. (5) The agent isolated from TLC plate was free from $H_2O_2$ or lactic acid. 4. Bioautographic assy: By means of bioautography of the agent on silica gel of TLC plate a strong inhibitory activity against B. subtilis was demonstrated. 5. Mass spectrometry: The agent obtained from TLC plate was analyzed by mass spectrometry which show the parent peak at m/e 264 suggesting the molecular weight of the compound and molecular group such as [$C_2H{^+}_4$], [CO], [CH=NH], [$C_3{H^}4_7$], [$\begin{array}{rcl}O\\{\parallel}\\CH_3-C\\\end{array}$], [$C_6-H{^+}_{11}$], [$C_5H{^+}_{11}$], [$\begin{array}{rcl}O\\{\parallel}\\C_5H_7-C^+\\\end{array}$] were suggested.

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Comparisons of Handling Practices of Culled Sheep Meat for Production of Mutton Curry

  • Mendiratta, S.K.;Kondaiah, N.;Anjaneyulu, A.S.R.;Sharma, B.D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.5
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    • pp.738-744
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    • 2008
  • In most developing countries consumers purchase retail cuts from hot carcasses and prepare traditional meat products as per their convenience and requirements. In this study, effects of different post mortem handling practices on quality of meat curry from culled sheep meat have been studied. After slaughter, leg cuts were subjected to nine commonly prevalent handling conditions in India viz. deboning (boning out) and cooking within 2-3 h (1), deboning immediately and cooking after 5-6 h (2), deboning after 5-6 h and cooking (3), deboning immediately, storage at $4^{\circ}C$ for 24 h and cooking (4), chilling for 24 h at $4^{\circ}C$, deboning and cooking (5), deboning after 5-6 h, storage for 24 h at $4^{\circ}C$, and cooking (6), deboning after 5-6 h, storage for 48 h at 4??C and cooking (7), deboning after 5-6 h, freezing and cooking (8), deboning after 5-6 h, storage for 24 h at $4^{\circ}C$, freezing and cooking (9). Significant differences were observed in pH, water-holding capacity, cooking loss and shear force values. Sensory scores were significantly higher in conditions (1), (5) and (9), and significantly lower in conditions (4) and (6). From the results, it was concluded that, to have the best quality product, meat should be cooked either immediately after slaughter or should be deboned just before cooking. Storage of deboned meat at refrigerated temperature must be avoided.

Thermal Stability and High Exchange Coupling Field of Bottom Type IrMn-Pinned Spin Valve (Bottom형 IrMn 스핀밸브 박막의 열적안정성과 높은 교환결합력)

  • Hwang, J.Y.;Kim, M.Y.;Rhee, J.R.
    • Journal of the Korean Magnetics Society
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    • v.12 no.2
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    • pp.64-67
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    • 2002
  • IrMn pinned spin valve (SV) films with stacks of Ta/NiFe/IrMn/CoFe/Cu/CoFe/NiFe/Ta were prepared by dc sputtering onto thermally oxidized Si (111) substrates at room temperature under a magnetic field of about 100 Oe. The annealing cycle number and temperature dependence of exchange coupling field (H$_{ex}$), magnetoresistance (MR) ratio, and coercivity (H$_{c}$) were investigated. By optimizing the process of deposition and post thermal annealing condition, we obtained the IrMn based SV films with MR ratio of 3.6%, H$_{ex}$ of 1180 Oe for the pinned layer. The H$_{ex}$ is stabilized after the second annealing cycle and it is thought that this SV reveals high thermal stability. The H$_{ex}$ maintained its strength of 600 Oe in operation up to 24$0^{\circ}C$ and decreased monotonically to zero at 27$0^{\circ}C$.

Low Resistance 3.3kV 4H-SiC Trench Shielded DMOSFET (Trench Shield 구조를 갖는 3.3kV급 저저항 4H-SiC DMOSFET)

  • Cha, Kyu-hyun;Kim, Kwang-su
    • Journal of IKEEE
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    • v.24 no.2
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    • pp.619-625
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    • 2020
  • In this paper, we propose a TS-DMOSFET(Trench Shielded DMOSFET) structure in which P+ shielding region is formed in a deeper region than C-DMOSFET(Conventional DMOSFET) and S-DMOSFET(Shielded DMOSFET). Using TCAD simulation to compare the static characteristics of TS-DMOSFET with C- and S-DMOSFET. As for the structure proposed, the doping is followed by the source trench process. Despite the fact that it is a SiC material, this allows it to form a P+ shielding region in a deep area. Followed by completely suppressing the reach-through effect. As a result, when the breakdown voltage of the three structures is 3.3kV, the Ron of TS-DMOSFET is 9.7mΩ㎠. Thus, it is 68% and 54% smaller than the Ron of C-DMOSFET and S-DMOSFET respectively.

Varistor Characteristics of ZPCCL-Based Ceramics Doped with $La_{2}o_{3}$ ($La_{2}o_{3}$가 첨가된 ZPCCL계 세라믹스의 바리스터 특성)

  • 정영철;류정선;남춘우
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.415-418
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    • 2001
  • The I-V characteristics and its stability of ZPCCL-based ceramic varistors doped with La$_2$O$_3$in the range of 0.0~4.0 mol% were investigated. The density of ceramics was increased in the range of 4.7~5.8 g/cm$^3$ with increasing La$_2$O$_3$content. As La$_2$O$_3$content is increased, the varistor voltage was decreased in the range of 503.49-9.42 V/mm up to 2.0 mol%, whereas increasing La$_2$O$_3$content further caused it to increase. The ZPCCL-based varistors were characterized by nonlinearity, in which the nonlinear exponent is in the range of 3.05~82.43 and leakage current is in the range of 0.24-100.22 $\mu$A. Among ZPCCL-based varistors, 0.5 mol% added-varistors exhibited an excellent nonlinearity, in which the nonlinear exponent is 82.43 and the leakage current is 0.24 $\mu$A. Furthermore, they exhibited a high stability, in which the variation rate of the varistor voltage and the nonlinear exponent was -1.11% and -6.72%, respectively, under DC stress, such as (0.80 V$_{1mA}$9$0^{\circ}C$/12h)+(0.85 V$_{1mA}$115$^{\circ}C$//12h) +(0.90 V$_{1mA}$12$0^{\circ}C$//12h)+(0.95 V$_{1mA}$1$25^{\circ}C$//12h)+(0.95 V$_{1mA}$15$0^{\circ}C$//12h). Consequently, it was estimated that ZPCCL-based ceramics will be applied to development of Pr$_{6}$O$_{11}$ based ZnO varistors having a high performance.e.rformance.e.

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Practical Utilization of Entomopathogenic Nematodes, Steinernema carpocapsae Pocheon Strain and Heterorhabditis bacteriophora Hamyang Strain for Control of Chestnut Insect Pests (밤 종실해충 방제를 위한 곤충병원성 선충, Steinernema carpocapsae 포천 계통과 Heterorhabditis bacteriophora함양 계통의 실용적 활용)

  • 추호렬;김형환;이동운;이상명;박선호;추영무;김종갑
    • Korean journal of applied entomology
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    • v.40 no.1
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    • pp.69-76
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    • 2001
  • The entomopathogenic nematodes, Steinernema carpocapsae Pocheon strain (ScP) and Heterorhabditis bacteriophora Hamyang strain (HbH) were evaluated against chestnut insect pests, The farmers'handling methods of chestnuts were taken into consideration to develop practical biological control with entomopathogenic nematodes . The major insect pests found with chestnuts were Curculio sikkimensis, Seichocrocis punctiferalis, and Cydia kurokoi. Although individual chestnut contained one species of insect was 58% representing 18% by C. sikkimensis, 27.7% by D. punctiferalis and 12.3% by C. kurokoi. The percentage of co-infection of C. sikkimensis with D. punctiferalis was 3.3%, C. sikkimensis with C. kurokoi 5.0%, D. punctiferalis with C. kurokoi 7.7%, and C. sikkimensis with D. punctiferalis and C. kurokoi 5.0%. The entomopathogenic nematodes, ScP and HbH were effective against all the species of chestnut insect pests. The $LC_{50}$ of ScP was 14.6 for C. sikkimensis, 4.6 for D. punctiferalis, and 5.6 for C. kurokoi and that of HbH was 49.2 for C. sikkimensis, 5.8 for D. punctiferalis, and 13.9 for C. kurokoi, respectively. When ScP was applied into pot including harvested chestnuts at the rate of 4,813 infective juveniles (Ijs)/pot $(=1\times10^9/ha)$, mortality of C. sikkimensis, D. punctiferalis, and C. kurokoi was 85.3%, 96.9%, and 68.1%, respectively. The mortality of C. sikkimensis, D. punctiferalis, and C. kurokoi was 60.73%, 96.5%, and 66.8%, respectively when HbH was applied at the same rate. Combination of two nematode species produced similar effects and insects were more infected by ScP than HbH. When chestnuts were soaked in the suspension of ScP at the rate of 300, 3,000, and 30,000 Ijs for 10 minutes or 30 minutes, mortalities of all chestnut insects were high irrespective of soaking time, concentration , and nematode species.

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Study on Photoelectrochemical Etching of Single Crystal 6H-SiC (단결정 6H-SiC의 광전화학습식식각에 대한 연구)

  • 송정균;정두찬;신무환
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.2
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    • pp.117-122
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    • 2001
  • In this paper, we report on photoelectrochemical etching process of 6H-SiC semiconductor wafer. The etching was performed in two-step process; anodization of SiC surface to form a deep porous layer and thermal oxidation followed by an HF dip. Etch rate of about 615${\AA}$/min was obtained during the anodization using a dilute HF(1.4wt% in H$_2$O) electrolyte with the etching potential of 3.0V. The etching rate was increased with the bias voltage. It was also found out that the adition of appropriate portion of H$_2$O$_2$ into the HF solution improves the etching rate. The etching process resulted in a higherly anisotropic etching characteristics and showed to have a potential for the fabrication of SiC devices with a novel design.

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