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Electrons and Holes in Semiconductors
Published in Jeffrey Olafsen, Sturge’s Statistical and Thermal Physics, 2019
Equations (14.6) through (14.8) hold only if ζ is within the band gap, and not so close to a band edge that Maxwell-Boltzmann statistics cease to apply. This is true for a pure semiconductor so long as kBT≪Eg, as is usually the case, but we shall find in Section 14.5 that ζ depends critically on the chemical purity of the semiconductor, and that Maxwell-Boltzmann statistics only apply if the impurity concentration is much less than nc or nv.
Radionuclide Generators for Biomedical Applications: Advent of Nanotechnology
Published in Feng Chen, Weibo Cai, Hybrid Nanomaterials, 2017
Rubel Chakravarty, Ramu Ram, Ashutosh Dash
The development of a 68Ge/68Ga generator which could directly be used for preparation of radiopharmaceuticals without the need for post-elution processing of 68Ga was first reported in 2010 (Chakravarty et al. 2010b). CeO2- PAN was used as the sorbent matrix in this generator, which was synthesized by decomposition of a cerium oxalate precursor to cerium oxide and its subsequent incorporation in PAN matrix. A 370 MBq (10 mCi) 68Ge/68Ga generator was prepared and its performance was evaluated for 7 months. Gallium-68 could be regularly eluted from this generator with > 70% elution yield with high radionuclidic purity (< 1 × 10–5% of 68Ge impurity), chemical purity (< 0.1 ppm of Ce, Fe and Mn ions) and was directly amenable for the preparation of 68Ga-labeled radiopharmaceuticals (Chakraborty et al. 2013). The generator gave a consistent performance with respect to the elution yield and purity of 68Ga throughout the period of investigation. Subsequently, the generator was scaled-up to 740 MBq (20 mCi) activity level and its performance was evaluated for 1 year (Chakravarty et al. 2013b). The 68Ge/68Ga generator was able to provide a 68Ga activity with consistent yields (> 70%) and having acceptable radionuclidic, radiochemical and chemical purities over this period of time. In another similar study, a 740 MBq (20 mCi) 68Ge/68Ga generator was developed using t-ZrO2 as the sorbent (Chakravarty et al. 2011a). The generator also gave a consistent performance with respect to the elution yield and purity of 68Ga over a period of 1 year and 68Ga availed from this generator was directly suitable for radiopharmaceutical preparation.
Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
Steam quality - Percent of saturated steam by weight in a steam/water mixture. Sometimes imporperly used for chemical purity and water and steam chemistry. Steam tables - Properties of steam (pressure, temperature, volume, enthalpy, entropy, etc.) shown in tabular or electronic form [13].
Dielectric properties of liquid crystals from the thioester series with a terminal polar group*
Published in Phase Transitions, 2019
M. D. Ossowska-Chruściel, A. Rudzki, J. Chruściel
The compounds 4-chlorophenyl-4'-pentyloxythiobenzoate (5OSCl), 4-chlorophenyl-4'-hexyloxythiobenzoate (6OSCl), and 4-nitrophenyl-4′-undecyloxythiobenzoate (11OSONO2) were synthesised in the Institute of Chemistry, Siedlce University of Natural Science and Humanities, Poland. The purity and chemical structures of all the compounds were confirmed by elemental analysis EA, IR, 1H NMR, and 13C NMR. FTIR spectra were recorded on an FTIR Nicolet Magna 760 spectrometer in the range of 4000–400 cm−1 using 64 co-added scans at the resolution of 1 cm−1. The NMR spectra were obtained on a VARIAN Unity Plus spectrometer operating at 500 MHz (CDCl3), using TMS as internal standard. The chemical purity was checked by thin layer chromatography (TLC) and further confirmed by elemental analysis using a Perkin-Elmer 2400 spectrometer.