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Fabrication and Post-Annealing Effects of Ferroelectric $Sr_xBi_yTa_2O_{9+\alpha}$(SBT) Thin Films by MOD Process (MOD법에 의한 강유전성 $Sr_xBi_yTa_2O_{9+\alpha}$(SBT) 박막의 제조 및 후열처리 효과에 관한 연구)

  • 정병직;신동석;윤희성;김병호
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.3
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    • pp.229-236
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    • 1998
  • Ferroelectric $Sr_xBi_yTa_2O_{9+\alpha}$/(0.7$\leqSr\leq1.0,\; 2.0\leqBi\leq2.6)$ solutions were prepared by MOD (Metalorganic Deposition) process. These solutions were made into thin films with thickness ranging from 1500~2000${\AA}$ by spin coating. The phase transformation of the SBT thin films by variation of annealing temperature and annealing time were observed using high temperature XRD and SEM. The crystallization and grain growth of SBT thin film were accomplished at $800^{\circ}C$ for 30 minutes after deposition of Pt top electrode by sputtering to prevent electrical breakdown. Ferroelectric properties of the SBT thin films were measured in the range of $\pm$3V\; and\; \pm5V$. The specimen with composition ratio of Sr/Bi/Ta (0.8/2.4/2.0) has the excellent ferroelectric properties ; $2P_r = 10.5,\; 13.2\muC/cm^2 \;at\; \pm3V\; and\; \pm5V$ respectively. Observing the post annealed Pt/SBT/Pt interface by SEM, it was found that Pt electrode sputtered on to the SBT thin film penetrated into the hollow on the SBT thin film, thus decreasing the effective insulation thickness. The effective insulation thickness recovered by post annealing, and this was confirmed by leakage current density measurement.

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Nutrient and Water Uptake of Cucumber Plant by Growth Stage in Closed Perlite Culture (순환식 펄라이트재배에서 생육단계에 따른 오이의 양수분 흡수 특성)

  • 김형준;김진한;우영회;남윤일
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2001.04b
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    • pp.73-74
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    • 2001
  • 순환식 펄라이트 재배에서 오이의 양액흡수는 일사량 변화와 관계없이 단위 일사량당 흡수량이 80-100mgㆍMJ$^{-1}$까지 증가 후 일정하게 유지되어 양액흡수 지표는 전체 양액흡수량보다 단위일사량당 양액흡수량이 더 적합하였다(Fig. 1). 오이의 엽장$\times$엽폭 수치와 실측 엽면적과의 관계는 Y=-16.87+0.987x+5E-5x$^2$의 회귀식을 구할 수 있었으며 $r^2$=0.89의 높은 정의 상관을 보였다. NO$_3$$^{-}$ -N의 흡수량은 초기에 3mgㆍMJ$^{-1}$에서 후기 16mgㆍMJ$^{-1}$로 상승하였고 Ca는 초기에 3mgㆍMJ$^{-1}$에서 후기에 14mgㆍMJ$^{-1}$로, Mg는 초기에 1mgㆍMJ$^{-1}$에서 후기에 5mgㆍMJ$^{-1}$로 증가되었으나, 정식 후 62일 이후의 증가세가 둔화되었다. K는 초기에 5.0mgㆍMJ$^{-1}$에서 후기 18mgㆍMJ$^{-1}$로 증가되었으나 지속적인 증가를 보여주지 못하였는데 이것은 오이의 하엽 제거로 인한 결과로 생각되어진다. 그러나 P는 초기에 0.5mgㆍMJ$^{-1}$에서 후기에 3.2mgㆍMJ$^{-1}$로 지속적으로 증가되었다. S는 초기에 0.5mgㆍMJ$^{-1}$에서 중기에 6.5mgㆍMJ$^{-1}$까지 증가되다가 후기에 2.7mgㆍMJ$^{-1}$로 감소되었다(Fig. 2). 오이의 각각의 무기이온 흡수량과 가장 상관이 높았던 요소는 정식일수와 엽면적이었으며 이 두 요소와 단위일사량당 양액흡수량과는 $r^2$=0.92, 0.97로 높은 상관을 보였다(Table 1). 단위일사량당 양액흡수량을 이용한 각각의 무기이온 흡수량 회귀식은 $r^2$=0.8 이상으로 높은 상관관계를 보여 실용적 이용이 가능할 것으로 보였다(Fig. 3).

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The Crystal and Molecular Structure of N-Acetyl-L-cysteine (N-Acetyl-L-cysteine의 결정 및 분자구조)

  • Young Ja Lee;Il-Hwan Suh
    • Journal of the Korean Chemical Society
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    • v.24 no.3
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    • pp.193-200
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    • 1980
  • The crystal structure of N-acetyl-L-cysteine, $C_5H_9NO_3S,$ has been determined from three dimensional photographic intensity data $(CuK{\alpha}$ radiation) by single crystal X-ray diffraction analysis. There is one formula unit in the triclinic unit cell with a = 7.04(3), b = 5.14(2), c = 8.25(3) ${\AA}$, ${\alpha}$ = 106(2), ${\beta}$ = 51(1), ${\gamma}$ = 124(2)$^{\circ}$ and space group P$_1$, The structure was solved by the direct method and refined by the full matrix least-squares method. The final R value is 12.3% for 629 observed reflections. The C-carboxyl group and the N-acetyl group are very neary planar. The molecule appears to form with neighboring molecules a hydrogen bond, $O-H{\cdot}{\cdot}{\cdot}O(3)$ of length 2.59${\AA}$.

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Crystal Structure of Byakangelicin ($C_{17}H_{18}O_{7}$)

  • Kim, Yang-Bae;Oh, Yong-Ho;Park, Il-Yeung;Shin, Kuk-Hyun
    • Archives of Pharmacal Research
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    • v.25 no.3
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    • pp.275-279
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    • 2002
  • The crystal structure of byakangelicin, one of furanocoumarin aldose reductase inhibitors, was determined by X-ray diffraction method. The crystal is triclinic, with a=8.114(1), b=10.194(1), $c=11.428(1)\AA,{\;}{\alpha}=111.50(1),{\}{\beta}=95.57(1),{\}{\gamma}=112.52(1)^{circ},{\;}D_x=1.41,{\;}D_m=1.39{\;}g/cm^3$, space group P1 and Z=2. The intensity data were collected by ${\omega}-2{\theta}$ scan method with $CuK_{a}$ radiations. The structure was solved by direct method and refined by full matrix least-squares procedure to the final R-value of 0.056. There are two molecules with different conformations in an asymmetric unit. The molecules are kept by two intermolecular O-HO type hydrogen bonds and van der Waal's forces in the crystal. The absolute configuration of the molecules was estimated to S-form by the 'Eta refinement' procedure.

A GaAs MMIC Multi-Function Chip with a Digital Serial-to-Parallel Converter for an X-band Active Phased Array Radar System (X-대역 능동 위상 배열 레이더 시스템용 디지털 직병렬 변환기를 포함한 GaAs MMIC 다기능 칩)

  • Jeong, Jin-Cheol;Shin, Dong-Hwan;Ju, In-Kwon;Yom, In-Bok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.6
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    • pp.613-624
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    • 2011
  • An MMIC multi-function chip for an X-band active phased array radar system has been designed and fabricated using a 0.5 ${\mu}m$ GaAs p-HEMT commercial process. A digital serial-to-parallel converter is included in this chip in order to reduce the number of the control interface. The multi-function chip provides several functions: 6-bit phase shifting, 6-bit attenuation, transmit/receive switching, and signal amplification. The fabricated multi-function chip with a relative compact size of 24 $mm^2$(6 mm${\times}$4 mm) exhibits a transmit/receive gain of 24/15 dB and a P1dB of 21 dBm from 8.5 GHz to 10.5 GHz. The RMS errors for the 64 states of the 6-bit phase shift and attenuation were measured to $7^{\circ}$ and 0.3 dB, respectively over the frequency.

The Evvalution of Different Factors Influencing the Quality of Silage (Silago 품질에 영향을 미치는 각종요인의 평가)

  • 한정대;윤익석
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.1 no.1
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    • pp.18-28
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    • 1978
  • To study about the effect of harvested stage and physical treatment such as wilting or chopping of plant material on the quality of silage, Italian ryegrass(Lolium multiflorum) harvested at pre-headed or heading stage and Seombadi(Dystaenia takesimana Nakai) harvested at pre-flowering stage, were used for the purpose. The materials were treated in four different ways which were a) non-treated, b) one day-wilted, c) chopped with 1 to 2cm length and d) wilted and chopped, and those were ensiled in plastic containers and stored at room temperature for three months. After three months of storage, it was investigated and obtained the following results. 1) Having 6.31 of NFE/CP ratio and low content of crude fiber, Seombadi contained more suitable constituents for silage than Italian ryegrass. 2) Under the non-treated or chopped condition, the loss of NFE was higher, and lower with wilted material. 3) Wilting or chopping improved DM digestibility. 4) Compared with Italian ryegrass harvested at pre-headed stage, the storage amount per unit volume of heading stage-Italian ryegrass and Seombadi were higher 8% and 69% respectively, and wilting and/or chopping increased the storage amount 41 to 134%. 5) The majority of weight loss during storage was observed at 1st week after ensiling, it continued slightly until 4th week. The highest loss in 8th week were 3.76% of nontreated material. 6) One day wilting increased DM content of silage 23 to 131%. Wilting and chopping increased pH and lactic acid improved the quality considerably. 7) The correlation between $NH_3$ and butyric acid, and between lactic acid and DM were r=0.782**, r=0.634** respectively. The regression equation were y=12.853X+4.908 (X=butyric acid), y=0.016X+1.309(X=DM content), respectively. 8. The above results indicate that it is necessary to wilt or chop material to make good quality silage from Italian ryegrass, and such treatment can improve the quality of silage with Seombadi also.

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Cloning and Expression of B. Aphaericus insecticidal toxin gene in E. coli

  • Lim, Pyong-Ok;Lee, Hong-Sup;Lee, Hyung-Hoan
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1986.12a
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    • pp.515.2-515
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    • 1986
  • B. sphaericus 1593 K-5 synthesize a potent entomicidal toxin against mosquito larvae. B. sphaericus EcoRl DNA fragment carrying the biocidal activity was clonied and expression in E. coli JM83. For the construction of a recombinant plasmid bearing the toxin activity the DNA of B. sphaericus was partially digested by the EcoRl. The EcoRl DNA fragments were ligated to plasmid pUC 8-EcoR1 site. The transformants were selected on LB plates containing X-gall and ampicilline. The transformants were bioassayed against mosquito larvae of which two clones showed biocidal activity. The two clones were redigested with Eco R1 and analyzed by 0.7% agarose gel electrophorsis.

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A Study for the Body Image, Self-esteem and Sociability of Elementary Students related on Obesity (남녀 초등학생들의 비만과 관련된 신체상, 자아존중감, 사회성에 대한 연구)

  • Park, Pil-Nam
    • Journal of the Korean Society of School Health
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    • v.20 no.2
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    • pp.13-21
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    • 2007
  • Purpose: The study was for researching the body image, self esteem and sociability of elementary students related on obesity. Methods: As the method, a convenience sample had been consisted of both 83 boys and 81 girls on 6th grade in elementary schools in Taebaek city. The data were collected through a self-report questionnaire between June 4th and June 8th, 2007. Then x2 test, One-way ANOVA, Scheff Test, and Pearson Correlation worked on the data using SPSS program. Results: On the result, 6th grade students have been perceived less on their overweight and obesity than the actual. On the research, 38.6% of the girls and 19.7% of the boys were actually obesity on their weight. However, 22.9% of the boys and 16.0% of the girls only has been recognized their obesity on the weight. Meantime 37.3% of the boys and 54.3% of the girl wanted to lose their weight. Body image has relatively a positive correlation by moderate level with self-esteem (r =.552. p<.01) and sociability(r=.509, p<.01) as well. Conclusion: As a conclusion of this study, health educators in elementary school need to lead for elementary students to improve their self-esteem and sociability through keeping normal weight. I would like to suggest that the educators need to develop a program for students to perceive the value of health and keep on normal weight.

Preparation of Alkyl and Aryl-thionocarbamate and their Anthelmintic action (Alkyl 급 Aryl thionocarbamate 류의 합성과 그 구충작용에 관한 연구)

  • 국채호
    • YAKHAK HOEJI
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    • v.7 no.2_3
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    • pp.58-66
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    • 1963
  • Alkyl-phenylthionocarbamates already have been investigated as anthelmintics. Especially ethyl-phenylthionocarbamate is noted for its anthelmintic action. Author studied methods for synthesizing Alkyl-phenylthionocarbamates, Alkyl-p-phenetyl thionocarbamates, Alkyl-cyclohexylthionocarbamates, 5 kinds for each. For alkyl radical $-CH_{3}$, $-C_{2}H_{5}$, -n-propyl, -isobuthyl, -n-buthyl, being chosen. Compounds VIII, X, XIII, XIV, and XV are new compounds. At the sametime author prepared 4 kinds of Arylthionocarbamates, among which XVII, and XIX being new compounds. (Table I) The anthelmintic action of these thionocarbamates has been examined through kymographic records indicating the action of neuromuscular preparation of Eisenia foetida Savigny in the various concentration fo above compounds: -Trendelenburg method. Santonine as the criterion of the estimation. (Table. II) 1. Compounds I-X could be prepared by method A or method B. method A in sealed tube brought on better yield and purity. 2. Compounds XI-XV couldn't be prepared by method A but by method B. 3. Arylthionocarbamates XVI, XVII, XVIII, and XIX couldn't be prepared by method A or method B but by method C. 4. Analyzed N. contained in all compounds. Analyzed C.H. and N. contained in unknown compounds, VIII, X, XIII, XIV, XV, XVII, and XIX. 5. Examination of anthelmintic action has been done under the advice of Prof. J.S.Oh medical college, Seoul Nat. University. 6. Compounds VI-X showed little action. 7. Compounds XVI-XIX showed almost no action. 8. Compounds XI-XV showed stronger action than compounds I-V, which was reported already as a usable anthelmintics. 9. Compounds XI, XII, XIII and XIV showed strongest actions, stronger than santonine as recorded on kymographion of the Trendelenburg method. Provided that, the toxity of these compounds found mild enough for human system, these compounds will serve as anthelmintics of greater powers than compounds I-V. 10. In Alkylthionocarbamates, R'NH-radical more influence on the anthelmintic action than ester radical(-OR).

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Refinement of the crystal structure of $>(Na, Ca)(Al, Si)_4O_8$ ($>(Na, Ca)(Al, Si)_4O_8$의 불안정상의 결정구조 정산)

  • 정수진
    • Korean Journal of Crystallography
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    • v.1 no.1
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    • pp.49-56
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    • 1990
  • The crystallizied Inactions of the two metastable phases in the glasses of plagioclase compositions were estimated by x-ray diffraction method. The orthorhombic metastable phase is easily drystaliized in the composition range of 70 to 80 mol% of albite, whereas the hexagonal metastable phase is mostly crystallized in the anonhite-rich side. For the purpose of refining the orthorhombic metastable structure some single crystal fragments of the composition Na,17ca‥‥All Isi2 nn were separated Som the crystallized glasses. The cell parameters of this crystal are a=8.237(1)A. b=8.644(1)A c=4.818(1)A. The space group of this crystal is Pn,2, Final atomic coordinates give R value of 0.040 and Rw of 0.028 with anisotropic thermal parameters. The position of Na and Ca atoms statistically distributed is splitted in two points with the occupancy of 0.5. The Si and Al atoms are statistically distributed in the six-membered ring of the Immm-type framework.

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