• Title/Summary/Keyword: High-$T_{c}$

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Poly-Si Thin Film Solar Cells by Hot-wire CVD

  • Lee, J.C.;Chung, Y.S.;Kim, S.K.;Yoon, K.H.;Song, J.S.;Park, I.J.;Kwon, S.W.;Lim, K.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.1034-1037
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    • 2003
  • Microcrystalline silicon(c-Si:H) thin-film solar cells are prepared with intrinsic Si-layer by hot wire CVD. The operating parameters of solar cells are strongly affected by the filament temperature ($T_f$) during intrinsic layer. Jsc and efficiency abruptly decreases with elevated $T_f$ to $1400^{\circ}C$. This deterioration of solar cell parameters are resulted from increase of crystalline volume fraction and corresponding defect density at high $T_f$. The heater temperature ($T_h$) are also critical parameter that controls device operations. Solar cells prepared at low $T_h$ ($<200^{\circ}C$) shows a similar operating properties with devices prepared at high $T_f$, i.e. low Jsc, Voc and efficiency. The origins for this result, however, are different with that of inferior device performances at high $T_f$. In addition the phase transition of the silicon films occurs at different silane concentration (SC) by varying filament temperature, by which highest efficiency with SC varies with $T_f$.

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Characterization of ${\mu}c$-Si:H Thin-film Solar Cells by Hot-wire CVD

  • Lee, J.C.;Chung, Y.S.;Kim, S.K.;Youn, K.H.;Song, J.S.;Park, I.J.;Kwon, S.W.;Lim, K.S.
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1598-1600
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    • 2003
  • Microcrystalline silicon(c-Si:H) thin-film solar cells are prepared with intrinsic Si-layer by hot wire CVD. The operating parameters of solar cells are strongly affected by the filament temperature ($T_f$) during intrinsic layer. Jsc and efficiency abruptly decreases with elevated $T_f$ to $1400^{\circ}C$. This deterioration of solar cell parameters are resulted from increase of crystalline volume fraction and corresponding defect density at high $T_f$ The heater temperature ($T_h$) are also critical parameter that controls device operations. Solar cells prepared at low $T_h$ (<$200^{\circ}C$) shows a similar operating properties with devices prepared at high $T_f$, i.e. low Jsc, Voc and efficiency. The origins for this result, however, are different with that of inferior device performances at high $T_f$. In addition the phase transition of the silicon films occurs at different silane concentration (SC) by varying filament temperature, by which highest efficiency with SC vanes with $T_f$.

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A Review on AC Loss Characteristics of High $T_c$ Superconductors

  • Amemiya, N.;Jiang, Z.
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.4
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    • pp.1-7
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    • 2006
  • This paper reviews AC loss characteristics of high $T_c$ superconductors. The mechanisms of AC loss generation are explained briefly, and AC losses are classified by the magnetic field components which generate them. A couple of analytical formulae of AC losses, which are useful for simple and rough AC loss estimations, are presented. AC loss characteristics of single BSCCO multifilamentary conductors and single YBCO coated conductors are reviewed based on previous experimental and numerical studies. AC loss characteristics of those two types of practical high $T_c$ superconductors are compared with each other.

Josephson Tunneling and Pairing Symmetry of High Tc Superconductor

  • Shin, E.J.;Nahm, Kyun;Chung, M.H;Kim, M.D.;Kim, C.K.;Noh, H.S.
    • Progress in Superconductivity
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    • v.1 no.2
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    • pp.85-88
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    • 2000
  • The temperature dependent Josephson critical current $J_c(T)/J_c(0)$ between high $T_c$ superconductors along the a-axis is theoretically studied. The interface influence on the wave functions of quasi-particles is included in the theory within the framework of the two-dimensional t-J model. It is found that the experimental results can be satisfactorily explained by the present model with d wave pairing symmetry.

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BRCA1 Gene Mutation Screening for the Hereditary Breast and/or Ovarian Cancer Syndrome in Breast Cancer Cases: a First High Resolution DNA Melting Analysis in Indonesia

  • Mundhofir, Farmaditya EP;Wulandari, Catharina Endah;Prajoko, Yan Wisnu;Winarni, Tri Indah
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1539-1546
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    • 2016
  • Specific patterns of the hereditary breast and ovarian cancer (HBOC) syndrome are related to mutations in the BRCA1 gene. One hundred unrelated breast cancer patients were interviewed to obtain clinical symptoms and signs, pedigree and familial history of HBOC syndrome related cancer. Subsequently, data were calculated using the Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) risk prediction model. Patients with high score of BOADICEA were offered genetic testing. Eleven patients with high score of BOADICEA, 2 patients with low score of BOADICEA, 2 patient's family members and 15 controls underwent BRCA1 genetic testing. Mutation screening using PCR-HRM was carried out in 22 exons (41 amplicons) of BRCA1 gene. Sanger sequencing was subjected in all samples with aberrant graph. This study identified 10 variants in the BRCA1 gene, consisting of 6 missense mutations (c.1480C>A, c.2612C>T, c.2566T>C, c.3113A>G, c.3548 A>G, c.4837 A>G), 3 synonymous mutations (c.2082 C>T, c.2311 T>C and c.4308T>C) and one intronic mutation (c.134+35 G>T). All variants tend to be polymorphisms and unclassified variants. However, no known pathogenic mutations were found.

The influence of atomosphere on high temperature crystal growth

  • Klimm, D.;Schroder, W.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.4
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    • pp.360-364
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    • 1999
  • The growth of crystals with high melting point$t_{fus}$$\geq$$1600^{\circ}C$ faces the researcher with experimental problems, as the choice of materials that withstand such high t is rather limited. Many metallic construction materials are in this high t range already molten or exhibit at least a drastically reduced mechanical strength. The very few materials with$t_{fus}$$1600^{\circ}C$ as e.g. W, Mo, and partially even Ir are more or less sensitive against oxygen upon heating. Whenever possible, high t crystal growth is performed under inert atmosphere (noble gases). Unfortunately, many oxides are not thermodynamically stable under such conditions, as reduction takes place within such atmosphere. A thoroughly search for suitable growth conditions has to be performed, that are on the one side "oxidative enough" to keep the oxides stable and on the other side "reductive enough" to avoid destruction of constructive parts of the crystal growth assembly. The relevant parameters are t and the oxygen partial pressure${po}_{2}$. The paper discusses quantitatively relevant properties of interesting oxides and construction materials and wasy to forecast theri behavior under growth conditions.

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Effect of the Cultivation Method and Cutting Time on the Growth Characteristics, Dry Matter Yield and Voluntary Intake in Sorghum X Sudangrass Hybrid (재배방식과 예취시기가 수수 X 수단그라스 교잡종의 생육특성, 건물수량 및 사일리지 채식성에 미치는 영향)

  • Lee Sang Moo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.25 no.1
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    • pp.7-16
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    • 2005
  • This experiments were carried out to determine growth characteristics, dry matter yield and voluntary intake of silage according to growth stage of Sorghum$\times$sudangrass(SSH) hybrid in mono-cropping and inter-cropping(C; com, T1; cutting of SSH at milk stage. T2; cutting of SSH at dough stage, T3; cutting of SSH at yellow ripe stage, T4; cutting of SSH and soybean at milk stage, T5; cutting of SSH and soybean at dough stage, T6: cutting of SSH and soybean at yellow ripe stage). Results obtained from these experiments are as follows; Plant length and leaf length of SSH(T2, T3, T4. T5 and T6)) were higher than C. T1 treatment was lower than it. C showed $2.3\~2.9$ times higher stem diameter as 29.5mm compare to SSH(T1, T2, T3, T4, T5 and T6). soybean(T4, T5 and T6) was lower in $4.3\~5.4$ times. But SSH of inter-cropping treatment(T4, T5 and T6) showed highly comparing with mono-cropping(T1, T2 and T3) at the same maturity. Leaf rate and stem hardness of SSH(T1, T2, T3, T4, T5 and T6) were lower than C. The fresh yield was high line with T2(72,320kg/ha), T1(69,103kg/ha), T3(68,333kg/ha) and C(57,988kg/ha), dry matter yield was high in line with T3(22.413kg/ha), T2(21,479kg/ha), C(19,252kg/ha) and T6(18,175kg/ha), (P<0.05). Protein dry matter yield was higher in T3(1,434kg/ha), C(1,386kg/ha)T5 and T6(1,345kg/ha) it was lower in T1(872kg/ha), (P<0.05). Crude protein of silage of T4 and T5 was higher than C, T2 and T3 were lower than it(P<0.05), while NDF content was not different. ADF content of T6 was higher than those of the other treatment. The highest hemi-cellulose among treatments was shown in T1 whereas T6 showed the lowest. Fresh intake of silge was 160.4, 155.8, 168.7, 172.9, 132.9, 158.7 and 185.2 g/BW for C, T1, T2, T3, T4, T5 and T6, respectively. Dry matter intake was high in line with T6(60.3g), C(153.8g), T3(53.6g), T5(47.8g), T2(46.8g), T4(35.2g) and T1(34.48g/BW), (P<0.05). Crude protein intake was high in line with T6(3.9g), T5(3.4g), C(3.4g), T2(2.9g), T3(2.9g), T4(2.6g) and T1(2.3g/BW), (P<0.05). As mentioned above the results, mono-cropping(T3) and inter-cropping(T5 and T6) could be recommended as increasing method of sorghum $\times$ sudangrass hybrid silage utilization when silage intake of dry matter and crude protein were considered.

Revival of Phonons in High Tc Superconductors

  • Bang, Yun-Kyu
    • Progress in Superconductivity
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    • v.9 no.2
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    • pp.127-135
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    • 2008
  • We study the effects of phonon interaction on the superconducting pairing in the high $T_c$ superconductors (HTSC). Using coupled BCS gap equations, we found that phonon interaction can induce a s-wave component to the d-wave gap, mediated by Antiferromagnetic (AFM) spin fluctuations, in the (D+iS) form. However, $T_c$ is not enhanced compared to the pure d-wave pairing without phonon interaction. On the other hand, anisotropic phonon interaction can dramatically enhance the d-wave pairing and $T_c$ itself, together with the AFM spin fluctuation interaction. This ($D_{AFM}+D_{ph}$) type pairing exhibits strongly reduced isotope coefficient despite the large enhancement of $T_c$ by phonon interaction.

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