• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.4
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• pp.144-148
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• 2005

In this study, the microwave dielectric properties of $0-6TiTe_3O_8-0.4MgTiO_3$ ceramic with $H_3BO_3$ and SnO were investigated to reduce the sintering time for the LTCC application. According to the X-ray diffraction patterns, both of $0-6TiTe_3O_8-0.4MgTiO_3$ ceramic with $H_3BO_3$ and SnO had the columbite structure of $TiTe_3O_8$ Phase, the ilmenite structure of $MgTiO_3$ phase. The density and dielectric constant of the $0-6TiTe_3O_8-0.4MgTiO_3$ ceramics with $H_3BO_3$ sintered at $830^{\circ}C$ for 1 hour were decreased but the quality factor was not changed with addition of $H_3BO_3$. Also the temperature coefficient of resonant frequency was not changed hardly. In the case of addition of SnO, the density and dielectric constant were increased but the quality factor was decreased and the temperature coefficient of resonant frequency was shifted to the negative(-) direction.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.79-79
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• 2002

본 연구에서는 in vitro에서 성숙된 난자의 핵성숙(Polar Body extrusion)에 소요되는 시간과 배반포 단계로의 발달능력 사이의 관계를 비교하여 조기에 발달능력을 가진 embryo를 선발할 수 있는 IVP 체계를 개발하고자 하였으며 in vitro maturation(IVM)에 따른 first polar body(PB) 형성, IVM과 IVF 시간이 oocyte의 발달에 미치는 영향과 생산된 배반포의 세포수를 평가하였다. IVM은 TCM199 배양액을 사용하였고 in vitro fertilization(IVF)은 Fer -TALP용액을 사용하였으며 in vitro culture(IVC)는 CRlaa 배양액을 사용하여 2일까지는 0.3% BSA를 3일 부터는 10%FBS와 bovine oviduct epithelial cell을 첨가하여 배양하였다. IVM 시간에 따른 PB의 출현율은 0hr(0%), 6hr(0%), 12hr(0%), 14hr(8.7%), 16hr(40.5%), 18hr(48.0%), 20hr(65%), 22(68%) 그리고 24hr(74.5%)을 보였으며 IVM 시간에 따른 cleavage 및 8cell 발달율 사이에는 유의적인 차이가 없었으나 배반포(BL) 및 8cell에서 배반포로 발달률은 18시간(BL 31$\pm$6, BL/8cell 82 $\pm$5%)에서 가장 높게 나타났으며 24시간(BL 17$\pm$2, BL/8cell 60$\pm$8%)과 유의적인 차이를 보였다(P<0.05). IVC 7일째 배반포의 총세포수와 trophoblast(TE) 세포수는 IVM 18시간(mean$\pm$S.E.; total: 131.1$\pm$34.0, TE: 97.6$\pm$29.6)에서 24시간(total: 112.2$\pm$17.5, TE: 80.1$\pm$15.6)보다 유의하게 많은 것으로 나왔으나(P<0.05) 7일째의 inner cell mass(ICM) 숫자(18hr 33.5$\pm$12.8 vs 24hr 32.1$\pm$12.0)와 8일째 ICM, TE 그리고 총 세포수에는 유의성 있는 차이가 없었다. IVM 18시간에서 PB 형성과 8cell 발달률 사이에 높은 상관성을 보였고 배반포 및 8cell에서 배반포 단계로 높은 발달률을 보였으며 생산된 배반포의 TE 숫자와 총 세포수가 유의하게 많은 것으로 나타났다. 따라서 IVM 18시간 실시하였을 경우 보다 많은 세포수를 가진 배반포 발달 가능성이 높은 embryo를 조기에 선발 가능할 것으로 사료된다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.1
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• pp.25-36
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• 1995

We have investigated the structure and the conductivity of the $Cd_{1-y}Zn_{y}$ Te films evaporated on the glass substrates (Corning 7059) by Electron Beam Evaporator (EBE) in pressure of approximately $1 {\times} 10^{-6}$ torr.The structure temperatures were held at both room temperature and $300^{\circ}C$, and the samples have annealed for an hour at $300^{\circ}C$ The survace com-position of the as-prepared films were slightly different from those of CdZn Te source material.Cd losses on the CdZnTe surface was measured about 4% of atomic ratio at room temperature substrate, whereas Zn atomic ratio was nearly constant, relatively. The strure is observed to be polycrystalline whose phase is mainly cubic phase. Thermal expansion coefficient was $6.30 {\times} 10^{-5}/^{\circ}C$ which was calculated from the variation of lattice parameter by X-ray powder pat-terns measured at $400^{\circ}C$.Diffraction peaks were slightly increased by annealing for an hour at $300^{\circ}C $, but they werey highly affected by substrate temperature during evaporation.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.6-8
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• 2004

A big boom in nanocomposites research has landed also in Japan. As a virtual 'center of excellence' in composites technology there, ACE TeC of ISTA/JAXA has led pioneering portions of nanocomposites research particularly in mechanical properties oriented applications. An overview of research activities based on nano-technologies in ACE TeC/JAXA will be given first and some remarkable results will be introduced briefly.

• Journal of the Korean Vacuum Society
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• v.3 no.3
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• pp.309-315
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• 1994

순간증착법으로 p형(Bi0.5Sb1.5Te3)과 n형(Bi2Te24Se0.6)열전박막을 제조하여 상온에서 Seebeck 계 수, 전기전도도 및 열전성능지수를 측정하였다. 또한 금속재 mask를 이용하여 다중접점 박막형 열전소 자를 제작하고 그 작동특성을 조사하였다. 이때 소자의 고온부와 저온부의 온도를 직접측정하기 위하여 copper/constantan 박막을 접점부에 증착하여 열전쌍이 되게 하였다. p/n 접점이 5쌍이 소자의 경우 Peltier 효과에 의해 생성된 최대온도차는 22K이었다.

• Solar Energy
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• v.17 no.3
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• pp.51-57
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• 1997

Cu-doped ZnTe thin films have been grown by hot-wall evaporation. The electrical conductivity of the intrinsic ZnTe film was of p-type and as low as $10^{-6}({\Omega}{\cdot}cm)^{-1}$. As the doped Cu concentration was increased, the electrical conductivity was increased. up to $10^2({\Omega}{\cdot}cm)^{-1}$, but the mobility was decreased a little. The heavily doped sample shows the metal-like electrical resistivity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.347-351
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• 2003

A p-$CdIn_2Te_4$ single crystal has been grown by the Bridgman method without a seed crystal in a tree-stage vertical electric furnace. From photocurrent measurements, it was found that three peaks, A, B, and C, corresponded to an intrinsic transition due to the band-to-band transition from the valence band states ${\Gamma}_7(A),\;{\Gamma}_6(B),\;and\;{\Gamma}_7(C)$ to the conduction band state ${\Gamma}_6$, respectively. Also, the valence band splitting of the $CdIn_2Te_4$ crystal has been confirmed by photocurrent spectroscopy. The crystal field splitting and the spin orbit splitting were obtained to be 0.2360 and 0.1119 eV, respectively. Also, the temperature dependence of the band gap energy of the $CdIn_2Te_4$ crystal has been driven as the following equation of $E_g(T)\;=E_g(0)\;-\;(9.43\;{\times}\;10^{-3})T^2/(2676\;+\;T)$. In this equation, the Eg(0) was estimated to be 1.4750, 1.7110, and 1.8229 eV at the valence band state A, B, and C, respectively. The band gap energy of the p-$CdIn_2Te_4$ at room temperature was determined to be 1.2023 eV.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.2
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• pp.267-276
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• 1999

A 2 stage 6-pole bandpass filter (BPF) is designed and implemented by using K-band triple-mode cavity. The BPF has an 100MHz bandwidth at the center frequency of 18.5GHz and the response of the filter is Chebyshev function. The cavity filter uses two orthogonal $TE_{113}$ modes and one $TM_{012}$ mode. To obtain a Chebyshev response, the intercavity coupling between the adjacent cavities is accomplished by H-field component of TE modes parallel to slot plate. In this paper, the size and location of intercavity slot are determined by the detailed coupling equation from H-field of TE resonant modes in circular cavity. The measured results agree well with the theoretical one.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.535-541
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• 1998

A 2 stage 6-pole bandpass filter(BPF) is designed and implemented by using triple-mode cavity for satellite payload system. The BPF has an 100 MHz bandwidth at the center frequency of 14.5 GHz, Ku-band. The cavity filter uses two orthogonal $TE_{113}$ modes and one $TM_{012}$ mode. The intercavity coupling between the adjacent cavities results in a Chebyshev response and is accomplished by H-field component of TE modes. The size and location of intercavity slot are determined by the coupling equation from H-field of TE resonant modes in circular cavity. The measured filter response agrees well with the theoretical data.

• Journal of Ceramic Processing Research
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• v.20 no.6
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• pp.582-588
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• 2019

FeVSb1-xTex (0.02 ≤ x ≤ 0.10) half-Heusler alloys were fabricated by mechanical alloying process and subsequent vacuum hot pressing. Near single half-Heusler phases are formed in vacuum hot pressed samples but a second phase of FeSb2 couldn't be avoided. After doping, the lattice thermal conductivity in the system was shown to decrease with increasing Te concentration and with increasing temperature. The lowest thermal conductivity was achieved for FeVSb0.94Te0.06 sample at about 657 K. This considerable reduction of thermal conductivities is attributed to the increased phonon scattering enhanced by defect structure, which is formed by doping of Te at Sb site. The phonon scattering might also increase at grain boundaries due to the formation of fine grain structure. The Seebeck coefficient increased considerably as well, consequently optimizing the thermoelectric figure of merit to a peak value of ~0.24 for FeVSb0.94Te0.06. Thermoelectric properties of various Te concentrations were investigated in the temperature range of around 300~973 K.