• Journal of the Korean Chemical Society
• /
• v.40 no.3
• /
• pp.161-166
• /
• 1996

6-ethyl-5,6-dihydrouracil($C_6H_10N_2O_2$) is monoclinic, space group $$P2_{1}c}$$ with a=10.302(2), b=10.419(3), $c=7.095(1)\AA$, $\beta=106.6(0)$, Z=4, $V=729.7(3)\AA$^3$$, $D_c=1.29 g/cm^3,\;{\lambda}(MoK\alpha)=0.71073\AA$, $\mu=0.010cm^{-1}$, F(000)=304, and R=0.054 for 1070 unique observed reflection with F>4.0 $\sigma(F).$ The structure was solved by direct methods and refined by full-matrix least-squares refinement with the fixed C-H bond length at $0.96\AA.$ The hydrouracil molecule makes an envelope conformation with the ethyl substituent oriented to an axial position attainable to a varying degree of steric strain. There are two intermolecular hydrogen-bondings via N-H---O interactions, being nearly parallel to the 100 plane. The shortest distance between molecules is $3.187\AA$ of C(4) and O(8) (-x,-y, 1-z).

• Journal of the Korean Chemical Society
• /
• v.42 no.2
• /
• pp.184-189
• /
• 1998

Tris(pentafluorophenyl)indium acetonitrile complexes have been prepared from the reaction of Indium trihalides (halogen=Cl, Br) and bis(pentafluorophenyl)cadmium in acetonitrile, and characterized by elementary analysis, $^13C{^1H}-,\; ^1H-\;and\; ^{19}F-NMR$ spectroscopy and mass spectrometry. The Indium (III) compounds were formed stable 1:1 adducts with acetonitrile. $In(C_6F_5)_3{\cdot}DMAP$ has been prepared from the ligand exchange reaction of In$(C_6F_5)_3 {\cdot} CH_3CN$ with DMAP in $CH_2Cl_2 {\cdot} DMAP$ has higher donating character and replaced the $CH_3CN$ through the ligand transfer reaction.

• Korean Journal of Microbiology
• /
• v.27 no.4
• /
• pp.342-347
• /
• 1989

by use of HCl-Giemsa technique and light microscope, dividing vegetative nuclei in hyphae of Fusarium species were observed and the results are summerized. The chromosome number of these fungi was ranged 4 to 8. Of the 20 strains, the highest haploid chromosome number is 8 in F. solani S Hongchun K4, F. moniliforme (from banana) and F. raphani (from radish). The lowest is 4 in F. sporotrichioides NRRL 3510 and F. equiseti KFCC 11843 IFO 30198. F. solani 7468 (from Sydney), F. solani 7475 (from Sydney), F. oxysporum(from tomato). F. roseum (from rice), F. sporotrichioides C Jngsun 1, F. equiseti C Kosung 1 and F. avenaceum 46039 are n=7. F. moniliforme (from rice) F. graminearum, F. proliferatum 6787 (from Syndey), F. proliferatum 7459 (from Synder) and F. anguioides ATCC 20351 are n=6. F. moniliforme NRRL 2284, F. poae NRRL 3287 and F. trincinctum NRRL 3299 are n=5. From these results, it may be concluded that the basic haploid chromosome number of the genus Fusarium is 4 and mat have been evolutionary variation of chromosome number through aneuploidy and polyploidy.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.328-329
• /
• 2012

$SF_6$ gas는 반도체 및 디스플레이 제조공정 중 Dry etch과정에서 널리 사용되는 gas로 자연적으로 존재하는 것이 아닌 사용 목적에 맞춰 인위적으로 제조된 gas이다. 디스플레이 산업에서 $SF_6$ gas가 사용되는 Dry etch 공정은 주로 ${\alpha}$-Si, $Si_3N_4$ 등 Si계열의 박막을 etch하는데 사용된다. 이러한 Si 계열의 박막을 식각하기 위해서는 fluorine, Chlorine 등이 사용된다. fluorine계열의 gas로는 $SF_6$ gas가 대표적이다. 하지만 $SF_6$ gas는 대표적인 온실가스로 지구 온난화의 주범으로 주목받고 있다. 세계적으로 온실가스의 규제에 대한 움직임이 활발하고, 대한민국은 2020년까지 온실가스 감축목표를 '배출전망치(BAU)대비 30% 감축으로' 발표하였다. 따라서 디스플레이 및 반도체 공정에는 GWP (Global warming Potential)에 적용 가능한 대체 가스의 연구가 필요한 상황이다. 온실가스인 $SF_6$를 대체하기 위한 방법으로 GWP가 낮은 $C_3F_6$가스를 이용하여 $Si_3N_4$를 Dry etching 방법인 RIE (Reactive Ion Etching)공정을 한 후 배출되는 가스를 측정하였다. 4인치 P-type 웨이퍼 위에 PECVD (Plasma Enhanced Chemical Vapor Deposition)장비를 이용하여 $Si_3N_4$를 200 nm 증착하였고, Photolithography공정을 통해 Patterning을 한 후 RIE공정을 수행하였다. RIE는 Power : 300 W, Flow rate : 30 sccm, Time : 15 min, Temperature : $15^{\circ}C$, Pressure : Open과 같은 조건으로 공정을 수행하였다. 그리고 SEM (Scanning Electron Microscope)장비를 이용하여 Etching된 단면을 관찰하여 단차를 확인하였다. 또한 Etching 전후 배출가스를 포집하여 GC-MS (Gas Chromatograph-Mass Spectrophotometry)를 측정 및 비교하였다. Etching 전의 경우에는 $N_2$, $O_2$ 등의 가스가 검출되었고, $C_3F_6$ 가스를 이용해 etching 한 후의 경우에는 $C_3F_6$ 계열의 가스가 검출되었다.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.11
• /
• pp.1619-1625
• /
• 2012

The purpose of this study is to determine long-term storage conditions for winter kimchi. Kimchi was stored in a kimchi refrigerator for 6 months with or without fermentation. Four different temperature systems used were as follows: 5 days at $10^{\circ}C$ followed by storage at $-2.5^{\circ}C$ (F1), 1 day at $15^{\circ}C$ followed by storage at $-2.5^{\circ}C$ (F2), storage at $-1^{\circ}C$ (S1), or at $-2.5^{\circ}C$ (S2). Time periods required for F1, F2, S1, or S2 kimchi to reach pH 4.4 and acidity 0.6% were 2, 8, 12, and 22 weeks, respectively. Lactobacillus spp. growth on F1 and F2 kimchi was faster and greater than that on S1 and S2 kimchi, revealing a maximum concentration of 8~9 verses 6.8 log CFU/mL, respectively. However, Leuconostoc spp. were fully grown (8~9 log CFU/mL) on all four kimchi samples regardless of temperature, even at $-2.5^{\circ}C$, although the times required to reach maximum growth were different. Growth of Lactobacillus and Leuconostoc spp. both decreased after reaching maximum levels, except for F1 kimchi. Sensory evaluation results for 3 month storage showed that F1 kimchi was the best among kimchi samples in terms of appearance, acidic taste, carbonated taste, crispiness, and moldy smell. For 6 months of storage, F1 and S1 kimchi were the most highly evaluated among the kimchi samples. Sensory evaluation result for S1 kimchi stored at $-1^{\circ}C$ was comparable to that of F1 kimchi due to fully grown Leuconostoc spp. Acidities of F1 and S1 kimchi after 6 months of storage were 0.8 and 0.7%, respectively. Taken together, fermentation of kimchi at $10^{\circ}C$ for 5 days followed by storage at $-2.5^{\circ}C$ for 6 months was optimal for high quality kimchi. Sensory properties of winter kimchi were significantly influenced by the degree of fermentation.

• Journal of the Korean Vacuum Society
• /
• v.7 no.4
• /
• pp.368-373
• /
• 1998

As device dimensions approach submicrometer size in ULSI, the demand for interlayer dielectric materials with very low dielectric constant is increased to solve problems of RC delay caused by increase in parasitic resistance and capacitance in multilevel interconnectins. Fluorinated amorphous carbon in one of the promising materials in ULSI for the interlayer dielectric films with low dielectric constant. However, poor thermal stability and adhesion with Si substrates have inhibited its use. Recently, amorphous hydrogenated carbon (a-C:H) film as a buffer layer between the Si substrate and a-C:F has been introduced because it improves the adhesion with Si substrate. In this study, therfore, a-C:F/a-C:H films were deposited on p-type Si(100) by ECRCVD from $C_2F_6, CH_4$and $H_2$gas source and investigated the effect of forward power and composition on the thickness, chemical bonding state, dielectric constant, surface morphology and roughness of a-C:F films as an interlayer dielectric for ULSI. SEM, FT-IR, XPS, C-V meter and AFM were used for determination of each properties. The dielectric constant in the a-C:F/a-C:H films were found to decrease with increasing fluorine content. However, the dielectric constant increased after furnace annealing in $N_2$atomosphere at $400^{\circ}C$ for 1hour due to decreasing of flurorine content. However, the dielectric constant increased after furnace annealing in $N_2$atmosphere at $400^{\circ}C$ for 1hour due to decreasing of fluorine concentration.

• Korean Journal of Crystallography
• /
• v.6 no.1
• /
• pp.27-35
• /
• 1995

The crystal structure of 1-tert-butoxycarbonyl-4-[N-(tert-butoxycarbonyl)-N-(ethoxycarbonylmethyl)amino]-3-phenylsulfonylpyrrolidind [C24H36O8N2S] has been from single crystal x-ray diffraction study ; C24H36O8N2S triclinic, p1, a=11.363(8)Å, b=11.589(6)Å, c=11.013(10)Å,α=95.32(6)°,β=98.64(7)°,γ=79.57(5)°,V=1406.8(18)Å3, t=293K, Z=2, CuKα(λ=1.5418Å). The molecular structure was solved by diredt method and refined by full-matrix least squares to a final R=9.78% for 3621 unique observed [F≥4σ(F)] reflections and 703 paramenters.

• Korean journal of applied entomology
• /
• v.37 no.1
• /
• pp.53-58
• /
• 1998

Comparative studies on some ecological characteristics of three phytoseiid mitespecies (one native; Arnblyseius womersleyi Schica, and two introduced species; A. fallacis Garmanand Typhlodromus occidentalis Nesbit) were carried out. The two-spotted spider mite (Tetranychusurticae Koch) was supplied as prey. Under four constant temperatures of 20, 23, 25 and 30f OS$^{\circ}$C,duration of growth from egg to adult for A. womer.vleyi was 11.5, 7.7, 6.7 and 5.6 days. While twoother species needed slightly shorter time but not significantly different. Critical temperature andeffective degree-days (DD) of A. womerslevi females were 83$^{\circ}$C and 1 1 1.6 DD, whereas those of A..fallacis were 10.7"C and 86.0 DD, and those of 7: occidentalis were 10.7"C and 94.1 DD. Also, thoseof males were similar to their females. Average longevity of females of A. womersleyi, A. fallucisand 7: occidentalis were 18.2 k 8.67, 19.6 3~7.18 and 13.0f5.66 days, total fecundity were 34.3 $-11.93, 39.8k 12.64 and 23.6k8.86, respectively. Under four constant temperatures of 20, 23, 25 and30-t0.S$^{\circ}$C, A. womersleyi consumed 9.1 f2.49, 9.7 k2.00, 9.7 f 2.61, and 10.3 k2.33 eggs of 7:urticae throughout their development. A. ,fizlluc~i.sc onsumed 10.2 k 2.52, 9.7 f2.29, 10.7 f 2.37 and10.1 k2.62 eggs, while, 7: occidentalis consumed 1 1.9 k3.43, 14.2 f4.50, 14.8 k 3.2 1 and 12.7 f2.95 eggs, respectively. Gravid females of A. womersleyi, A. f~zllacis and 7: occidentalis consumed11.4f1.59, 12.5k1.43 and 11.7k3.07 eggs, or consumed 11.9f 2.63, 12.4k3.82, and 12.5f 3.73protonymphs of 7: urticae in a day at 25-30$^{\circ}$C.e in a day at 25-30$^{\circ}$C.

• IMMUNE NETWORK
• /
• v.13 no.6
• /
• pp.295-300
• /
• 2013

Der f 2 is the group 2 major allergen of a house dust mite (Dermatophagoides farinae) and its function has been recently suggested. To determine the optimal condition of sensitization to recombinant Der f 2 (rDer f 2) in murine model of asthma, we compared the effectiveness with different adjuvants in BALB/c and C57BL/6 mice. Mice from both strains sensitized with rDer f 2 by intraperitoneal injection or subcutaneous injection on days 1 and 14. The dosage was $20{\mu}g$. Freund's adjuvants with pertussis toxin (FP) or alum alone were used as adjuvants. On days 28, 29, and 30, mice were challenged intranasally with 0.1% rDer f 2. We evaluated airway hyperresponsivenss, eosinophil proportion in lung lavage, airway inflammation, and serum allergen specific antibody responses. Naive mice were used as controls. Airway hyperresponsiveness was increased in C57BL/6 with FP, and BALB/c with alum (PC200: $13.5{\pm}6.3$, $13.2{\pm}6.7$ vs. >50 mg/ml, p<0.05). The eosinophil proportion was increased in all groups; C57BL/6 with FP, BALB/c with FP, C57BL/6 with alum, BALB/c with alum ($24.8{\pm}3.6$, $20.3{\pm}10.3$, $11.0{\pm}6.9$, $5.7{\pm}2.8$, vs. $0.0{\pm}0.0$%, p<0.05). The serum allergen specific IgE levels were increased in C57BL/6 with FP or alum (OD: $0.8{\pm}1.4$, $1.1{\pm}0.8$, vs. $0.0{\pm}0.0$). C57BL/6 mice were better responders to rDer f 2 and as for adjuvants, Freund's adjuvant with pertussis toxin was better.

• Korean Journal of Materials Research
• /
• v.7 no.11
• /
• pp.934-941
• /
• 1997

C $r_{3}$ $C_{2}$-20wt% NiCr 이 크래드된 분말을 이용하여 HVOF 용사층의 특성(미세조직, 결정상, 경도 그리고 erosion rate)에 미치는 연료/산소 비(=3.2,3.0,2.8,2.6)의 영향을 조사했다. 실험범위 내에서 F/O=3.0의 경우가 C $r_{3}$ $C_{2}$-20wt%(NiCr)크래드 분말의 최적용사조건 이었다. XRD분석결과 F/O비에 관계없이 카바이드분해는 일어 났다. C $r_{3}$ $C_{2}$에서C $r_{7}$ $C_{3}$로의 상변화는 F/O비가 감소함에 따라 증가했다. 열처리 온도가 높아짐에 따라 C $r_{7}$ $C_{3}$분율은 증가 하였으며, 100$0^{\circ}C$에서 50시간 열처리후 용사층의 주된상은 C $r_{7}$ $C_{3}$이였다. 용사상태에서 경도값은 F/O=3.0조건으로 용사된 코팅층이 $H_{v300}$-1040으로 가장 높았으며, 공기중에서 $600^{\circ}C$, 50시간 열처리한 후, 경도값은 1340으로 증가하였다. 그리고 80$0^{\circ}C$열처리 후 경도값은 약간 감소하였다. 그러나 100$0^{\circ}C$ 열처리 후에도 1060정도로 용사상태의 경우 보다는 높은 경도값을 유지하였다. 이와같이 경도값이 증가하는 이유는 열처리에 따라 용사층이 치밀하게 되고 또한 C $r_{2}$ $O_{3}$의 산화물이 C $r_{3}$ $C_{2}$/C $r_{7}$ $C_{3}$ 내에 생성되어 탄화물/산화물 복합체를 이루기 때문으로 생각된다. 용사상태에서 drosion rate는 F/O비에 따라 2.6-3.05x$10^{-4}$mg/g까지 변화하였다. 또한 $600^{\circ}C$열처리 후에는 2.15-2.3 x $10^{-4}$mg/g이였으며, 80$0^{\circ}C$에서 열처리한 후에는 2.3-2.4x$10^{-4}$mg/g으로 $600^{\circ}C$열처리후 보다 약간 높은 결과를 보였다.결과를 보였다.