Materials Science and Engineering / Malzeme Bilimi ve Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4719

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  • Article
    Citation - WoS: 10
    Citation - Scopus: 7
    Assessment of Melt Cleanliness of Secondary 5000 Aluminum Alloy Via Non-Metallic Inclusions Characterization
    (Springer, 2023) Li, Cong; Gökelma, Mertol; Dang, Thien; Huang, Jinxian; Huang, Chunfa; Li, Jianguo; Friedrich, Bernd; Gökelma, Mertol; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The extensive energy consumption of primary aluminum production stimulates increasing need of producing primary-quality alloys with secondary sources, during which process amount of non-metallic inclusions (NMIs) in the alloy must be strictly controlled. In the present study funded by AMAP Open Innovation Research Cluster, NMIs generated during remelting a 5000 Al-Mg alloy was investigated to offer benchmarking characters of NMIs with respect to type, morphology, size, composition, and concentration. Under different remelting conditions NMIs formed in the melt ahead of solidification were concentrated using Porous Disc Filtration Apparatus (PoDFA) and characterized microstructurally and quantitatively. Investigated conditions included heating cycle, organic contaminations, and refractory materials. Results suggested oxide films and cuboid particles as typical oxides with, respectively, different compositions. The amount of formed oxides declined with the increase of heating rate. With respect to aluminum carbide (Al4C3), organic contaminations were confirmed to lead to an increased amount of its formation. The carbon-containing refractory material contributed more significantly than organic contaminations on the formation of Al4C3 at melt temperatures over 760 & DEG;C. Formulas were derived based on trial results to enable translation of NMIs PoDFA value [mm(2)/kg] into their mass fraction [ppm] in the melt.
  • Article
    Citation - WoS: 17
    Citation - Scopus: 19
    Strong Coupling of Carbon Quantum Dots in Liquid Crystals
    (American Chemical Society, 2022) Sarısözen, Sema; Polat, Nahit; Balcı, Fadime Mert; Güvenç, Çetin Meriç; Kocabaş, Çoşkun; Balcı, Sinan; Balcı, Sinan; Polat, Nahit; 04.04. Department of Photonics; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    Carbon quantum dots (CDs) have recently received a tremendous amount of interest owing to their attractive optical properties. However, CDs have broad absorption and emission spectra limiting their application ranges. We herein, for the first time, show synthesis of water-soluble red emissive CDs with a very narrow line width (∼75 meV) spectral absorbance and hence demonstrate strong coupling of CDs and plasmon polaritons in liquid crystalline mesophases. The excited state dynamics of CDs has been studied by ultrafast transient absorption spectroscopy, and CDs display very stable and strong photoluminescence emission with a quantum yield of 35.4% and a lifetime of ∼2 ns. More importantly, we compare J-aggregate dyes with CDs in terms of their absorption line width, photostability, and ability to do strong coupling, and we conclude that highly fluorescent CDs have a bright future in the mixed light-matter states for emerging applications in future quantum technologies.