• Title/Summary/Keyword: materials science

Search Result 32,411, Processing Time 0.055 seconds

Characteristics of Silk Sericin Extracted from Sericinjam

  • Kweon, Hae-Yong;Yeo, Joo-Hong;Kim, Kee-Young;Kim, Yong-Soon;Song, Ha-Seok;Kim, Su-Jin;Woo, Soon-Ok;Han, Sang-Mi;Lee, Kwang-Gill
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.18 no.2
    • /
    • pp.121-124
    • /
    • 2009
  • We investigated sericin extracted from sericinjam, which was inbred at National Academy of Agricultural Science, Suwon, Korea. Sericinjam sericin is composed of 5 fractions: 250 kDa, 120 kDa, 90 kDa, 70 kDa and 40 kDa. Amino acid analysis showed that the major amino acids of sericinjam sericin were Ser, Gly, Asp, Glu, Thr and Ala. Infrared spectra showed that sericinjam sericin has $\beta$-sheet structure. Thermal property of sericin was investigated using DSC and then they showed characteristic degradation peak at around $215{\sim}240^{\circ}C$.

Research Trends of High-entropy Alloys (고엔트로피 합금의 연구동향)

  • Park, Pureunsol;Lee, Ho Joon;Jo, Youngjun;Gu, Bonseung;Choi, Won June;Byun, Jongmin
    • Journal of Powder Materials
    • /
    • v.26 no.6
    • /
    • pp.515-527
    • /
    • 2019
  • High-entropy alloys (HEAs) are generally defined as solid solutions containing at least 5 constituent elements with concentrations between 5 and 35 atomic percent without the formation of intermetallic compounds. Currently, HEAs receive great attention as promising candidate materials for extreme environments due to their potentially desirable properties that result from their unique structural properties. In this review paper, we aim to introduce HEAs and explain their properties and related research by classifying them into three main categories, namely, mechanical properties, thermal properties, and electrochemical properties. Due to the high demand for structural materials in extreme environments, the mechanical properties of HEAs including strength, hardness, ductility, fatigue, and wear resistance are mainly described. Thermal and electrochemical properties, essential for the application of these alloys as structural materials, are also described.

Enhanced Photovoltaic Performance of Perovskite Solar Cells by Copper Chloride (CuCl2) as an Additive in Single Solvent Perovskite Precursor

  • Kayesh, Md. Emrul;Matsuishi, Kiyoto;Chowdhury, Towhid H.;Kaneko, Ryuji;Noda, Takeshi;Islam, Ashraful
    • Electronic Materials Letters
    • /
    • v.14 no.6
    • /
    • pp.712-717
    • /
    • 2018
  • In this letter, we have introduced copper chloride ($CuCl_2$) as an additive in the $CH_3NH_3PbI_3$ precursor solution to improve the surface morphology and crystallinity of $CH_3NH_3PbI_3$ films in a single solvent system. Our optimized perovskite solar cells (PSCs) with 2.5 mol% $CuCl_2$ additive showed best power conversion efficiency (PCE) of 15.22%. The PCE of the PSCs fabricated by $CuCl_2$ (2.5 mol%) additive engineering was 56% higher than the PSC fabricated with pristine $CH_3NH_3PbI_3$.