• 한국전기전자재료학회논문지
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• 제16권7호
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• pp.604-610
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• 2003

The effects of sintering additives such as B $i_2$ $O_3$ and $V_2$ $O_{5}$ on the microwave dielectric and sintering properties of (Z $n_1$$_{-xM}$ $g_{x}$)Ti $O_3$ system were investigated. Highly dense samples were obtained for (Z $n_{0.8}$M $g_{0.2}$)Ti $O_3$ at the sintering temperature range of 870~90$0^{\circ}C$ with B $i_2$ $O_3$ and $V_2$ $O_{5}$ additions of 〈1 wt.%, respectively. The microwave dielectric properties of (Z $n_{0.8}$M $g_{0.2}$)Ti $O_3$ with 0.45 wt.%B $i_2$ $O_3$ and 0.55 wt.% $V_2$ $O_{5}$ sintered at 90$0^{\circ}C$ were as follows : Q$\times$ $f_{o}$ = 50,800 GHz, $\varepsilon$$_{r}$ = 22, and $\tau$$_{f}$ = -53 ppm/$^{\circ}C$. In order to improve temperature coefficient of resonant frequency, Ti $O_2$ was added to the above system. The optimum amount of Ti $O_2$ was 15 moi.% when sintered at 87$0^{\circ}C$, at which we could obtain following results: Q$\times$ $f_{o}$ = 32,800 GHz, $\varepsilon$$_{r}$ = 26, and$\tau$$_{f}$ = 0 ppm/$^{\circ}C$.EX>.EX>.EX>.EX>.EX>.EX>.EX>.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.133-133
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• 2015

Recently, it has been shown that the ${\omega}B97X-D/aVTZ$ method is strongly recommended as the best practical density functional theory(DFT) for rigorous and extensive studies of saturated or unsaturated $C_4F_8$ species because of its high performance and reliability especially for van der Waals interactions. All the feasible isomerization and dissociation paths of $C_4F_8$ molecules were investigated at this theoretical level and rate constants of their chemical reactions were computed by using variational transition-state theory for a deep insight into $C_4F_8$ reaction mechanisms. Fates and roles of C4F8 molecules and their fragments in plasma phases could be clearly explained based on our computational results.

• 한국동물학회지
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• 제34권3호
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• pp.389-393
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• 1991

To obtain monozygotic multiplets from 8-cell mouse embryos, we artificially constructed chimeric embryos by introducing one blastomere (donor) of 8-cell embryos of Fl hybrid (C57BL/6 X CBA) mice into 4-cell ICR mouse embryos (carrier) of which one blastomere had been previously removed with a micromanipulator. After 42 h of culture, the developmental frequency of chimeric embryos to normal morula and blastocyst was 95% (310/328). When chimeric embryos at morula or blastocvst stage were transferred to pseudopregnant mice,39%, (70/180) of them were born. Most of the offspring (56/70) were the carrier type in coat color, whereas only three of them were the donor type, of which ho were assumed to be derived from single 8-cell donor embryo. Because the two donor type mice Ivere the same sex and produced only the donor type offspring from a testcross, they are probably monozvgotic multiplets of 8-cell mouse embryos. However, since their internal chimerism was not able to be examined, it remains to be determined if their genetic constitutions are identical.

• 한국의학물리학회지:의학물리
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• 제23권2호
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• pp.114-122
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• 2012

선형가속기의 출력선량의 평가는 표준선원에 의한 조사선량교정인수 $N_x$나 공기커마교정인수 $N_k$또는 더 나아가 물흡수 선량교정인수를 가진 공동전리함을 이용하여 이루어지며, 선량프로토콜에 따라 교정인수가 다르다. $N_x$를 사용하는 TG-21 프로토콜은 Bragg-Gray 공동이론에 근거하여 기체흡수교정인수를 구하고 공동전리함의 내경과 벽재질과 두께, 공동길이 등에 따라 보정인수가 정해지므로 다소 복잡한 계산절차를 가지므로 누적오차가 발생할 수 있다. TG-51은 물 흡수선량교정인수를 이용하므로써 복잡한 절차를 크게 줄여 계산오차를 피할 수 있게 되었다. 대개 1차표준국에서는 $N_x$나 $N_k$ 및 $N_{dw}{^{Co-60}}$을 제공하여 왔으므로, $N_{dw}$가 정해지지 않은 TM31010 계열의 공동전리함에 대해 $N_x$ 또는 $N_k$로 TG-21을 이용하여 $N_{dw}$를 결정하는 프로그램을 준비했으며, 기존 $N_x$와 $N_{dw}$가 제공된 IC-15 전리함의 것과 비교하여 좋은 일치결과를 얻었다. 반면에 TM31010은 이차표준국(SSDL, Secondary Standard Dosimetry Laboratory)에서 제공된 $N_k$로 $N_{dw}$를 구한 결과 우송형 열형광소자(TLD, Thermo Luminescence Device)에 의한 출력선량모니터 결과 불안정한 결과를 계기로 한국 표준과학연구원의 1차 표준선량시험(PSDL)의 교정인수와 비교한 결과 0.4%와 -2.8%로 각각 나타나 SSDL의 교정인수와 차이를 보여, $N_{dw}$가 정해져 있지 않거나 평가선량이 의심스러울 때는 선량프로토콜의 절차에 과한 세밀한 검토와 전리함의 교정계수에 대한 교차점검이 필요함을 알았다.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2703-2706
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• 2012

New C60 fullerenes derivatives [G1]-C60 (1) and [G2]-C60 (2) comprising of phenylenevinylene bridges and phenylquinoline peripheral surface groups were synthesized by 1,3-dipolar cycloaddition reaction of fullerene C60 with azomethine ylide in situ generated from [Gx]-CHO dendrons (x = 1 and 2) and sarcosine.

• Bulletin of the Korean Chemical Society
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• 제29권8호
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• pp.1572-1574
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• 2008

• Journal of Chest Surgery
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• 제23권2호
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• pp.366-369
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• 1990

Primary choriocarcinoma of the lung is extremely rare. The patient was 28-year-old female and had no specific signs and symptoms except right chest pain for 5 years. On simple chest film, 8X8 cm sized, well demarcated, homogeneous ovoid mass was found on right lower lung field. The qualitative urine \ulcorner-HCG was 17140 mIU/ml. The result of percutaneous needle biopsy highly suggested choriocarcinoma. Under the impression of primary choriocarcinoma of the lung, right middle and lower lobectomy was done. On 33 postoperative days, serum \ulcorner-HCG level was within normal limit, the patient was discharged without complications after one-cycle chemotherapy.

• 대한의용생체공학회:의공학회지
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• 제2권1호
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• pp.39-46
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• 1981

Microstructural phases of the dental amalgams have been studied by optical microscope, scanning electron microprobe and X-ray diffractometer. r1 ($Ag_2Hg_3$) phase and r2 ($Sn_{7-8}Hg$) phase are found on conventional compositioned alloys. On high copper single compositioned alloy, rl ($Ag_2Hg_3$) phase and V ($Cu_6Sn_5$) phase are found but brittle r2 ($Sn_(7-8)Hg$) phase.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2761-2764
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• 2011

A new Ruddlesden-Popper phase $NdSr_2MnCrO_7$ has been prepared by the standard ceramic method. The powder X-ray diffraction studies suggest that the phase crystallizes with tetragonal unit cell in the space group I4/mmm. The electrical transport properties show that the phase is an electrical insulator and the electrical conduction in the phase occurs by a 3D variable range hopping mechanism. The magnetic studies suggest that the ferromagnetic interactions are dominant.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1986년도 추계학술발표회 논문집
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• pp.8-11
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• 1986

Data acquisition system is needed in signal analysis and processing by using computer. This paper realizes the high speed data acquisition system by using 8bit, 20MHZ refresh A/D converter and 18 x 64 Byte high speed memory. The high speed data acquisition system provides converted data to IBM-PC XT micro computer.