• 제목/요약/키워드: Research laboratory

검색결과 16,299건 처리시간 0.051초

Optical and Dielectric Properties of Chalcogenide Glasses at Terahertz Frequencies

  • Kang, Seung-Beom;Kwak, Min-Hwan;Park, Bong-Je;Kim, Sung-Il;Ryu, Han-Cheol;Chung, Dong-Chul;Jeong, Se-Young;Kang, Dae-Won;Choi, Sang-Kuk;Paek, Mun-Cheol;Cha, Eun-Jong;Kang, Kwang-Yong
    • ETRI Journal
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    • 제31권6호
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    • pp.667-674
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    • 2009
  • Terahertz time-domain spectroscopy has been used to study the optical and dielectric properties of three chalcogenide glasses: $Ge_{30}As_8Ga_2Se_{60}$, $Ge_{35}Ga_5Se_{60}$, and $Ge_{10}As_{20}S_{70}$. The absorption coefficients ${\alpha}({\nu})$, complex refractive index n(${\nu}$), and complex dielectric constants ${\varepsilon}({\nu})$ were measured in a frequency range from 0.3 THz to 1.5 THz. The measured real refractive indices were fitted using a Sellmeier equation. The results show that the Sellmeier equation fits well with the data throughout the frequency range and imply that the phonon modes of glasses vary with the glass compositions. The theory of far-infrared absorption in amorphous materials is used to analyze the results and to understand the differences in THz absorption among the sample glasses.

Transcription Analysis of Recombinant Trichoderma reesei HJ-48 to Compare the Molecular Basis for Fermentation of Glucose and Xylose

  • Huang, Jun;Lin, Mei;Liang, Shijie;Qin, Qiurong;Liao, Siming;Lu, Bo;Wang, Qingyan
    • Journal of Microbiology and Biotechnology
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    • 제30권10호
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    • pp.1467-1479
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    • 2020
  • Profiling the transcriptome changes involved in xylose metabolism by the fungus Trichoderma reesei allows for the identification of potential targets for ethanol production processing. In the present study, the transcriptome of T. reesei HJ-48 grown on xylose versus glucose was analyzed using next-generation sequencing technology. During xylose fermentation, numerous genes related to central metabolic pathways, including xylose reductase (XR) and xylitol dehydrogenase (XDH), were expressed at higher levels in T. reesei HJ-48. Notably, growth on xylose did not fully repress the genes encoding enzymes of the tricarboxylic acid and respiratory pathways. In addition, increased expression of several sugar transporters was observed during xylose fermentation. This study provides a valuable dataset for further investigation of xylose fermentation and provides a deeper insight into the various genes involved in this process.

Electron Temperature, Plasma Density and Luminous Efficiency in accordance with Discharge Time in coplanar AC PDPs

  • Jeong, S.H.;Moon, M.W.;Oh, P.Y.;Jeong, J.M.;Ko, B.D.;Park, W.B.;Lee, J.H.;Lim, J.E.;Lee, H.J.;Han, Y.G.;Son, C.G.;Lee, S.B.;Yoo, N.L.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1203-1206
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    • 2005
  • Electron temperature and plasma density in coplanar alternating-current plasma display panels (AC-PDP's) have been experimentally investigated in accordance with discharge time by a micro-probe in this experiment. The resolution of a step mortor to move in micro-Langmuir probe is 10um.[1-3] The used gas in this experiment is He-Ne-Xe (4%) mixure gas. And sustain voltage is 320V which is above of firing voltage for degradation. The electron temperature and plasma density can be obtained from current-voltage (I-V) characteristics of micro Langmuir probe, in which negative to positive bias voltage was applied to the probe. And Efficiency is calculated by formula related discharge power and light emission. Those experiments operated as various discharge time ($0{\sim}72$ Hours). As a result of this experiment, Electron Temperature was increased from 2eV to 5eV after discharge running time of 20 hours and saturates beyond 20 hours. The plasma density is inversely proportional to the square root of electron temperature. So the plasma density was decreased from $1.8{\times}10^{12}cm^{-3}$ to $8{\times}10^{11}cm^{-3}$ at above discharge running time. And the Efficiency was reduced to 70% at 60hours of discharge running time.

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Ion-induced secondary electron emission coefficient and work function for MgO thin film with $O_2$ plasma treatment

  • Jung, J.C.;Jeong, H.S.;Lee, J.H.;Oh, J.S.;Park, W.B.;Lim, J.Y.;Cho, J.W.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.525-528
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    • 2004
  • The ion-induced secondary electron emission coefficient ${\gamma}$ and work function for MgO thin film with $O_2$ plasma treatment has been investigated by ${\gamma}$ -FIB (focused ion beam) system. The MgO thin film deposited from sintered material with $O_2$ plasma treatment is found to have higher ${\gamma}$ and lower work function than those without $O_2$ plasma treatment. The energy of various ions used has been ranged from 100eV to 200eV throughout this experiment. It is found that the highest secondary electron emission coefficient ${\gamma}$ has been achieved for 10 minutes of $O_2$ plasma treatment under RF power of 50W.

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Transgene Expression of Biologically Active Human Follicle-Stimulating Hormone in Milk and Histological Analysis

  • Myoung-Ok Kim;Kil-Soo Kim;Eun-Ju Lee;Sung-Hyun Kim;Jun-Hong Park;Kyoungin-Cho;Boo-Kyung Jung;Hee-Chul Kim;Sol-ha Hwang
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2004년도 춘계학술발표대회
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    • pp.214-214
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    • 2004
  • Follicle stimulating hormone (FSH) is a pituitary glycoprotein composed of two post translationally modified subunits, which must properly assemble to be biologically active. We developed a transgenic (TG) mouse model that overexpresses the human Follicle-Stimulating hormone (FSH) -subunit under the bovine -casein promoter, displaying in females an excessive levels express in mammary gland. (omitted)

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Methylation Changes at the First Exon of Bovine oct-4 Gene in Embryos Produced Either by In Vitro Fertilization or Somatic Cell Nuclear Transfer

  • Seungeun Yeo;Park, Jung-Sun;Wee, Kap-In;Lee, Hyo-Sang;Koo, Deog-Bon;Lee, Kyung-Kwang;Han, Yong-Mahn;Kang, Yong-Kook
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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    • pp.62-62
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    • 2002
  • The relationship of Oct-4 to pluripotent cells is suggested by its tightly restricted expression pattern during embryonic development. Just prior to implantation it is limited to pluripotent cells of the inner cell mass (ICM) that will form the embryo proper but is not expressed in the trophectoderm, the structure that will form the extraembryonic tissues. (omitted)

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NbTi 관내 3연선 도체의 안정성 (Stability of Triplet NbTi Cable-In-Conduit Conductor)

  • 장현만;오상수;하동우;하홍수;배준한;김상철;류강식;왕추량
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 A
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    • pp.82-84
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    • 1998
  • The normal zone propagation velocity and minimum quench energy (MQE) of cable-in-conduit conductors (CICC) has been investigated at the different background magnetic fields and supercritical helium pressures. The sample CICC of 2 m in length was fabricated with triplet NbTi/Cu strands inserting into a round stainless-steel tube. The heat pulse disturbance with duration time about 400 ms was acted on the center region of the CICC to quench the strands. The normal zone propagation velocity increased with operating current of the CICC. The measured velocity with respect to operation current could be fitted with numerical results.

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Three Month Subacute Toxicity Study of Ginkgo Biloba Extract(EGb 761) in Rats

  • Lee, Yong-Soon;Nam, Jeong-Seok;Che, Jeong-Hwan;Lee, Suk-Man;Yang, Jae-Man;Kang, Byeong-Cheol;Lee, Hak-Mo;Park, Jae-Hak;Chai, Chan-Hee;Kang, Sung-An
    • Toxicological Research
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    • 제12권1호
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    • pp.113-119
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    • 1996
  • Group of 40 male and 40 female Sprague-Dawley rats was given daily intravenous injections of different dosage of Ginkgo biloba extract(EGb 761), 7.5 mg/kg/day (low dosage group), 15 mg/kg/day (middle dosage group), or 30 mg/kg/day (high dosage group)for 3 month by tail vein according to Established Regulation of Korean National Institute of Safety Research (1994. 4. 14). Appearance, behavior, mortality, and food consumption of rats of treated groups were not affected during the experimental periods. No significant Ginkgo biloba extract(EGb 761)-related changes were found in urinalysis, hematology, serum chemistry, and organ weight. No histopathological lesions were seen in both control and treatment groups. Our results strongly suggest that no toxic changes were found in rat treated intravenously with Ginkgo biloba extract(EGb 761)for 3 month.

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