16 research outputs found

    A comparative thermodynamic analysis of ORC and Kalina cycles for waste heat recovery: A case study for CGAM cogeneration system

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    A thermodynamic modeling and optimization is carried out to compare the advantages and disadvantages of organic Rankine cycle (ORC) and Kalina cycle (KC) as a bottoming cycle for waste heat recovery from CGAM cogeneration system. Thermodynamic models for combined CGAM/ORC and CGAM/KC systems are performed and the effects of some decision variables on the energy and exergy efficiency and turbine size parameter of the combined systems are investigated. Solving simulation equations and optimization process have been done using direct search method by EES software. It is observed that at the optimum pressure ratio of air compressor, produced power of bottoming cycles has minimum values. Also, evaporator pressure optimizes the performance of cycle, but this optimum pressure level in ORC (11 bar) is much lower than that of Kalina (46 bar). In addition, ORC's simpler configuration, higher net produced power and superheated turbine outlet flow, which leads to a reliable performance for turbine, are other advantages of ORC. Kalina turbine size parameter is lower than that of the ORC which is a positive aspect of Kalina cycle. However, by a comprehensive comparison between Kalina and ORC, it is concluded that the ORC has significant privileges for waste heat recovery in this case

    Interaction of sulforaphane with DNA and RNA.

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    Sulforaphane (SFN) is an isothiocyanate found in cruciferous vegetables with anti-inflammatory, anti-oxidant and anti-cancer activities. However, the antioxidant and anticancer mechanism of sulforaphane is not well understood. In the present research, we reported binding modes, binding constants and stability of SFN-DNA and -RNA complexes by Fourier transform infrared (FTIR) and UV-Visible spectroscopic methods. Spectroscopic evidence showed DNA intercalation with some degree of groove binding. SFN binds minor and major grooves of DNA and backbone phosphate (PO2), while RNA binding is through G, U, A bases with some degree of SFN-phosphate (PO2) interaction. Overall binding constants were estimated to be K(SFN-DNA)=3.01 (± 0.035)×10(4) M(-1) and K(SFN-RNA)= 6.63 (±0.042)×10(3) M(-1). At high SFN concentration (SFN/RNA = 1/1), DNA conformation changed from B to A occurred, while RNA remained in A-family structure

    Intensity ratio variations for several DNA and RNA in-plane vibrations as a function of SFN concentration.

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    <p>(A) Intensity ratios for DNA bands at 1714 (G, T), 1665 (T, G, A, C), 1610 (A), 1490 (C,G) and 1226 (PO2 asymmetric) referenced to the DNA band at 966 cm<sup>-1</sup>. (B) Intensity ratios for the RNA bands at 1697 (G, U), 1650 (U, G, A, C), 1610 (A), 1488 (C,G) and 1241 (PO2 asymmetric) referenced to the RNA band at 969 cm<sup>-1</sup>.</p

    Docking structure between (PDB 2R22) and SFN.

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    <p>(A) Surface representation of (PDB 2R22) complexes with SFN (Display side). (A') Close up view of (PDB 2R22) complexes with SFN. (B) Surface representation of (PDB 2R22) complexes with SFN (Display top).</p

    Docking structure between (PDB 3CZW) and SFN.

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    <p>(A) Surface representation of (PDB 3CZW) complexes with SFN (Display side). (A') Close up view of (PDB 3CZW) complexes with SFN. (B) Surface representation of (PDB 3CZW) complexes with SFN (Display top).</p

    Docking structure between d(CGCGAATTCGCG) (PDB 1BNA-DNA) and SFN.

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    <p>(A) Surface representation of d(CGCGAATTCGCG) complexes with SFN (Display side). (A') Close up view of d(CGCGAATTCGCG) complexes with SFN. (B) Surface representation of d(CGCGAATTCGCG) complexes with SFN (Display top).</p

    Ultraviolet–visible results of SFN and calf thymus DNA and its Complexes (A), and yeast RNA and its complex (B): (1) SFN–DNA and SFN–RNA complexes; (2) free DNA or free RNA (0.5 mM); (3) free SFN (0.5 mM).

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    <p>Plot of 1/(A-A<sub>0</sub>) versus (1/drug concentration) for SFN and calf thymus DNA complexes (A<sup>'</sup>), and plot of 1/(A-A<sub>0</sub>) versus (1/drug concentration) for SFN and yeast RNA complexes (B<sup>'</sup>), where A<sub>0</sub> is the initial absorbance of DNA (259 nm) or RNA at (258 nm) and A is the recorded absorbance at different SFN concentrations (5×10<sup>–6–</sup>1×10<sup>–4</sup> M) with constant DNA or RNA concentrations of 0.5 mM at pH 7.</p

    FTIR spectra in the region of 1800–800 cm<sup>-1</sup> for sulforaphane (SFN), calf thymus DNA (A) and yeast RNA adducts (B) in aqueous solution at pH = 7.

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    <p>DNA or RNA and two complexes spectra were obtained at various SFN/DNA and-RNA (phosphate) molar ratios (three two spectra); sulforaphane and two difference spectra (bottom three spectra).</p
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