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Indexed at: search.filters.indexed.ScopusSubject: search.filters.subject.Spectrum analysis

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    An archaeometric assessment study of Seljuk period glazed tiles from Kılıçarslan Square (Konya, Turkey)
    (Springer Nature, 2022) Öztürk, Çetin; Kuşoğlu, İhsan Murat; N/A; Franci, Gülsu Şimşek; Researcher; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); N/A; N/A
    This study presents archaeometric analyses of glazed tiles produced with the cut-mosaic technique to reveal information about the Anatolian Seljuk period’s architecture and ceramic technology. The Persian Seljuk artists also used the same technique. For this purpose, physical, chemical, thermal, mineralogical, microstructural, and molecular analyses were carried out on the tiles from the Seljuk period unearthed in the Kılıçarslan Square excavation in Konya, the capital of the Anatolian Seljuk State from the twelfth-century to the beginning of the fourteenth-century. SEM, XRD, and Heat Microscopy analyses showed that the Seljuk period tiles were not fired at high temperatures like today’s tiles and were probably fired at temperatures below 1100 °C. WD-XRF analyses revealed that the glazes are classified into two categories, one being alkali varying the content of Na2O + K2O between 13 and 16 wt% (PbO between 0.5 and 2 wt%) and the other being lead-alkali type in which PbO content varies between 13 and 15 wt% and alkali content 10–14 wt%. The cobalt content in the blue color is around 0.2 wt%, and copper content in the turquoise-colored samples varies between 2.9 and 4.4 wt% depending on the lightness and darkness of the color (higher amount for tile 1 and tile 3, which are darker than the others). The brown color is obtained by the presence of MnO (3.3 wt%). Raman analysis showed that the difference in sintering temperature caused the color tone difference in Seljuk period tiles, and glazes were formed in the range of 800–1000 °C depending on the Ip values.
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    Two-wavelength grating interferometry for extended range MEMS metrology
    (IEEE, 2007) N/A; N/A; Department of Electrical and Electronics Engineering; Toy, Muhammed Fatih; Ferhanoğlu, Onur; Ürey, Hakan; Master Student; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 205198; 8579
    Diffraction gratings integrated with MEMS has many applications as they can offer shot noise limited sub-nm displacement detection sensitivities but are limited in range. a two-wavelength readout method is developed that maintains high sensitivity while increasing the detection range from 105nm to 1.7um assuming sensitivity is maintained at > 50% of the maximum sensitivity.
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    Vibrational spectra, force constants and quantum chemical calculations of mu-1,3-azide bridged triphenylphosphine complexes of copper(I) and silver (I)
    (Elsevier, 2022) Güven, Gökçe; Afyon, Semih; Yılmaz, Ayberk; Bölükbaşı, Olcay; N/A; Department of Chemistry; Topçu, Ahmet Umur; Somer, Mehmet Suat; N/A; Faculty Member; Department of Chemistry; N/A; College of Sciences; N/A; 178882
    The dimeric title compounds [(C6H5)(3)P]Cu-2(N-3)(2) and [C6H5)(3)P]Ag-2(N-3)(2) were synthesized and characterized by FT-Raman and IR spectroscopy. The two phases were not isotypic but possessed approximately the same molecular symmetry which was C-2/2m. The assignment of the modes was supported by quantum chemical DFT calculations coupled with TED (Total Energy Distribution) analyses. The calculated (N-N) force constants for the bridging -(NNN)- groups were directly comparable (f(N-N) = 11.75 (Cu) and 12.19 N cm(-1)(Ag)) and harmonized well with those of the free azide anion in the binary alkali azides. The (N-N) bond orders were obtained based on the calculated force constants (Siebert Bond Order, SBO) and Density-dependent electrostatic and chemical (DDEC6) method yielding SBO = 1.92 (Cu) and 1.96 (Ag) and BO = 2.00 (Cu) and 2.03 (Ag), respectively, indicating the presence of double bonds. The results underlined that the (N-N) force constants and bond orders in the bridging azide units were practically unaffected by the nature of the central metal atoms and that they could be regarded as quasi isolated anions similar to those in the binary azide compounds.