• Title/Summary/Keyword: $B_2H_6$

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Synthesis of Boron-doped Crystalline Si Nanoparticles Synthesized by Using Inductive Coupled Plasma and Double Tube Reactor (유도결합 플라즈마와 이중관 반응기를 이용하여 제조한 보론-도핑된 결정질 실리콘 나노입자의 합성)

  • Jung, Chun-Young;Koo, Jeong-Boon;Jang, Bo-Yun;Lee, Jin-Seok;Kim, Joon-Soo;Han, Moon-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.10
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    • pp.662-667
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    • 2014
  • B-doped Si nanoparticles were synthesized by using inductive coupled plasma and specially designed double tube reactor, and their microstructures were investigated. 0~10 sccm of $B_2H_6$ gas was injected during the synthesis of Si nanoparticles from $SiH_4$ gas. Highly crystalline Si nanoparticles were synthesized, and their crystallinity did not change with increase of $B_2H_6$ flow rates. From SEM measurement, their particle sizes were approximately 30 nm regardless of $B_2H_6$ flow rates. From SIMS analysis, almost saturation of B in Si nanoparticles was detected only when 1 sccm of $B_2H_6$ was injected. When $B_2H_6$ flow rate exceeded 5 sccm, higher concentration of B than solubility limit was detected even if any secondary phase was not detected in XRD or HR-TEM results. Due to their high electronic conductivity, those heavily B-doped Si nanoparticles can be a potential candidate for an active material in Li-ion battery anode.

Synthesis of (${\pm}$)-cis-8-amino-l-2,3,4,4a,5,10b-hexahydrothiazolo[4,5-f]indeno [1,2-b][1,4]oxazine ((${\pm}$)-cis-8-Amino-2,3,4,4a,5,10b-hexahydrothiazolo[4,5-f]indeno [1,2-b][1,4]oxazine의 합성)

  • Ma, Eun-Sook
    • YAKHAK HOEJI
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    • v.52 no.6
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    • pp.488-493
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    • 2008
  • 2-Aminothiazole ring as a bioisoster of catechol in dopamine has provided with good oral availability and lipophilic property. 2-Aminoindan, is a rigid form of dopamine, was evaluated as a dopamine D3 agonist with low neurotoxicity. Dopamine D3 agonist was evaluated as selective for the treatment of Parkinson's disease. In order to develop a novel dopamine D3 agonist, we tried to synthesize the aminothiazoloindenoxazine derivative that is a hybrid structure of aminoindenoxazine and thiazole ring. cis-2-Amino-1-indanol (2) was synthesized from 1,2-indandione-2-oxime by catalytic hydrogenation and it was treated with chloroacetyl chloride and NaH in benzene solution to give (${\pm}$)-cis-4,4a,5,9b-tetrahydroindeno[1,2-b][1,4]oxazin-3(2H)-one (6). Nitration of 6 by the mixed acid gave 8-nitro compound (7) and the carbonyl group of 7 was reduced with $LiAlH_4$ to afford compound (8). 8 was reduced to form (${\pm}$)-cis-8-amino-2,3,4,4a,5,9b-hexahydroindeno[1,2-b][1,4]oxazine (9) and finally it was cyclized with KSCN in glacial acetic acid to yield (${\pm}$)-cis-8-amino-2,3,4,4a,5,10b-hexahydrothiazolo[4,5-f]indeno[1,2-b][1,4]oxazine (10).

A Case Of Circadian Sleep Disorder Improved By Acupuncture On $Zh{\grave{a}}h{\grave{a}}i$(K6, 照海) And $Sh{\bar{e}}nm{\grave{a}}i$(B62) (신지.조해혈(照海穴)의 자침(刺鍼)으로 호전(好轉)된 일교차성 수면장애 치험(治驗)1례(例))

  • Lee, Kyung-Min;Kim, Tae-Hi;Kim, Sung-Uk
    • The Journal of Korea CHUNA Manual Medicine
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    • v.2 no.1
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    • pp.169-175
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    • 2001
  • Objects : The purpose of this study is find out significant (clinical) effect of applying acupuncture on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) of ${\bar{U}m-kyo-maek$(陰?脈) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) of Yang-kyo-maek(陽?脈) to a patient of circadian sleep disorder. Methods : We apply acupuncture on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) to a patient of circadian sleep disorder during 2 weeks. We check sleeping time day and night during 14 days. Acupuncture on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) has significant effect to circadian sleep disorder patient. Results : Acupuncture on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) has significant effect to circadian sleep disorder patient. Conclusions : 1. The physio-pathologic phenomenon of sleeping is relative to ${\bar{U}m-kyo-maek$(陰?脈) and Yang-kyo-maek(陽?脈) 2. Acupuncture therapy on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) has significant effect to circadian sleep disorder.

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Surface Passivation and Heterojunction Solar Cell Characteristics Depending on p a-Si:H/c-Si Deposition (P a-Si:H 증착조건에 따른 실리콘 기판 계면특성 및 a-Si:H/c-Si 이종접합 태양전지 동작특성 분석)

  • Jeong, Dae-Young;Kim, Chan-Seok;Song, Jun-Yong;Park, Sang-Hyun;Cho, Jun-Sik;Yoon, Kyoung-Hoon;Song, Jin-Soo;Wang, Jin-Suk;Yi, Jun-Sin;Lee, Jeong-Chul
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.28-30
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    • 2009
  • 이종접합태양전지에서 p a-Si:H/c-Si의 p a-Si:H의 증착 조건인 $H_2/SiH_4$ 비율, $B_2H_6$의 농도를 변화 시키며 실험하여 이 따라 계면 특성 변화를 연구하였다. pa-Si:H의 $H_2/SiH_4$ 비율이 상승할수록 carrier lifetime이 증가하다 다시 감소하는 경향을 나타내었다. 이는 $H_2/SiH_4$의 비율 중 효과적으로 웨이퍼표면을 효과적으로 passivation하는 지점이 있는 것으로 보인다. $B_2H_6$의 농도는 상승할수록 carrier lifetime이 줄어드는 경향을 보였다. $B_2H_6$에서 농도가 올라감에 웨이퍼 표면의 defect로 작용했을 것으로 생각된다. 이에서 몇몇의 조건으로 태양전지를 제작한 결과 $H_2/SiH_4$ 비율에 따라서는 carrier lifetime은 효율에 그 영향이 미미한 것으로 조사되었고, $B_2H_6$의 농도가 낮을수록 개방전압은 상승하는 결과를 얻어 도핑 농도가 효율에 직접적인 형향을 주는 것으로 나타났다.

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Aminolysis of Benzyl 2-Pyridyl Thionocarbonate and t-Butyl 2-Pyridyl Thionocarbonate: Effects of Nonleaving Groups on Reactivity and Reaction Mechanism

  • Kim, Min-Young;Lee, Jae-In;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.34 no.4
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    • pp.1115-1119
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    • 2013
  • A kinetic study is reported for nucleophilic substitution reactions of benzyl 2-pyridyl thionocarbonate (5b) and t-butyl 2-pyridyl thionocarbonate (6b) with a series of alicyclic secondary amines in $H_2O$ at $25.0^{\circ}C$. General-base catalysis, which has often been reported to occur for aminolysis of esters possessing a C=S electrophilic center, is absent for the reactions of 5b and 6b. The Br${\o}$nsted-type plots for the reactions of 5b and 6b are linear with ${\beta}_{nuc}$ = 0.29 and 0.43, respectively, indicating that the reactions of 5b proceed through a stepwise mechanism with formation of a zwitterionic tetrahedral intermediate ($T^{\pm}$) being the rate-determining step while those of 6b proceed through a concerted mechanism. The reactivity of 5b and 6b is similar to that of their oxygen analogues (i.e., benzyl 2-pyridyl carbonate 5a and t-butyl 2-pyridyl carbonate 6a, respectively), indicating that the effect of modification of the electrophilic center from C=O to C=S (i.e., from 5a to 5b and from 6a to 6b) on reactivity is insignificant. In contrast, 6b is much less reactive than 5b, indicating that the replacement of the $PhCH_2$ in 5b by the t-Bu in 6b results in a significant decrease in reactivity as well as a change in the reaction mechanism (i.e., from a stepwise mechanism to a concerted pathway). It has been concluded that the contrasting reactivity and reaction mechanism for the reactions of 5b and 6b are not due to the electronic effects of $PhCH_2$ and t-Bu but are caused by the large steric hindrance exerted by the bulky t-Bu in 6b.

The Solvent-Independent Structure of 6-(2-pyridyl)-3, 5-hexadiyn-1-ol (6-(2-pyridyl)-3, 5-hexadiyn-1-ol의 용매 비의존 분자구조)

  • 서일환;이진호
    • Korean Journal of Crystallography
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    • v.6 no.1
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    • pp.36-42
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    • 1995
  • Two types of single crystals of the title compound [6-(2-pyridyl)-3, 5-hexadiyn-ol, PyHxD] were obtained by solution of n-hexane/CH2C12 and n-hexane/Et2O, and their molecular conformations are proved identical in spite of different of space groups; C22H18N2O2 (I), Mr=343.70, Monoclinic, Pa, a=14.595(2), b=5.413(2), c=12.218(2)Å, β=96.86(1)°, V=958.3Å3, Z=2, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=292K, R=0.104 for 756 unique observed reflections. An asymmetric unit contains a dimer connected by two N-H…O intermolecular hydrogen bonds. C11H9NO (II), Mr=171.85, Monoclinic, P21/a, a=14.611(2), b=5.423(6), c=12.191(2)Å, β=96.89(1)°, V=959.0Å3, Z=4, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=293K, R=0.066 for 824 unique observed reflection. The structural asymmetric unit contains a molecule, but two N-H…O hydrogen bonds related by controsymmetry make the molecules form a dimer. In both structure, the dihedral angle between the planar pyridyl ring and the plane defined by C(10)-C(11)-O connected by linear diyne chain is approximately normal, and the molecules are stacked along b-axis with the unit repeat of b-axis.

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Adhesion of Bifidobacteria to Caco-2 Cells and in Relation to Cell Surface Hydrophobicity (비피도박테리아의 Caco-2 세포에 대한 부착성과 세포 표면 소수성)

  • Lim, Kwang-Sei;Huh, Chul-Sung
    • Food Science of Animal Resources
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    • v.26 no.4
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    • pp.497-502
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    • 2006
  • The adhesion of 16 bifidobacterial strains, including 10 isolates from Korea infants, to Caco-2 cells and their cell surface hydrophobicity were tested. The results of adhesion and cell surface hydrophobicity of for various bifidobacterial strains were obtained and correlations between adhesion and hydrophobicity were strain-dependent properties. Any correlations between species of tested strains were not observed. Among the tested strains, Bifidobacterim longum D6, B. longum H4, B. thermophilum ATCC 25525, B. suis ATCC 27533, and B. animalis subsp. lactis BB12 had higher adherent properties and B. bifidum B3, B. longum D6, B. longum stronger hydrophobicity, respectively. Due to the strain-dependant correlation between adhesion to Caco-2 cells and cell surface hydrophobicity of bifidobacteria, these results provide a possible method for preliminary selection of bifidobacteria potentially adherent to Caco-2 cells by means of cell surface hydrophobic properties.

THE STUDY ON THE NOISE IN THE VESSEL (선박소음에 관한 연구)

  • PARK Jung-Hee;KIM Sang-Han
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.8 no.4
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    • pp.202-207
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    • 1975
  • During the term of June, 7 to August 11, the noises in the maine engine room in terms of the r. p. m. of the Pung-Yang Ho (4,500 H. P.), the Chuk-Yang Ho (3,800 H. P.), the Dong-Bang Ho (3,000 H. P.), the Oh-Dae San Ho (2,690 H, P.), the Kwan-Ak-San Ho (1,000 H. P.) and the Back-Kyung Ho (850 H. P.) (Refer to Table 1) were measured with the use of sound level meter, which has measuring range 37-140 dB and the results obtained are as follows : 1. Capacity of the engine room becomes large according to the total H. P. of the main engine, but the vessels are using of a type of engine, i.e., 6 cylinder, and thus the noise, pressure has shown a tendency to become lower except Kwan-Ak-San Ho, Chuk-Yang Ho and Dong Bang Ho where the noise pressure was higher by 3 dB than curve of mean value. 2. The maximum noise pressure appeared even before the main engine reached the maximum r. p. m. and while the percentage of the r. p. m. varied depending on the vessel, the maximum noise appeared at around the $67-75\%$ of the r. p. m. 3. The maximum of noise pressure in the respective engine room ranged between 93.5-105 dB while it was between 72-81 dB at the fish process room in the stern trawl vessel where the oral communications were possible.

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