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Article Citation - WoS: 1Hedging Effectiveness of Gold: an Analysis for the Banking Sector With Different Dynamic Portfolio Approaches(Economic and Financial Research Assoc - Efad, 2022) Ozdemir, HuseyinIn this study, we construct portfolios including gold and six major stock exchanges (& Idot;sbank, Garanti Bank, Akbank, Yap & imath; Kredi Bank, Halkbank, Aand Vak & imath;fbank) by using three different dynamic portfolio approaches (i.e., minimum variance, minimum correlation, and minimum connectedness approaches). The aim of the study is to investigate whether gold can be used as a hedge against six major banks operating in Turkey. Further, this study also aims to measure the hedging effectiveness of gold. We adopt a fully time- varying parameter vector auto-regression (TVP-VAR) econometric framework, applied to daily data spanning June 2018 to November 2022. Empirical results show that the optimal ratio of gold in bank stocks varies between 39% and 53%, depending on time and portfolio construction approach. It is observed that the volatility of bank stocks in the portfolios has decreased by approximately 75%. According to the MCP and MCoP approaches, the highest return was obtained from the portfolio constructed with the MVP approach. In addition, the empirical findings show that gold can be used as a hedging instrument against banking stocks in bear market conditions.Article Citation - WoS: 125Citation - Scopus: 130Pdau-mnox< Nanoparticles Supported on Amine-Functionalized Sio2 for the Room Temperature Dehydrogenation of Formic Acid in the Absence of Additives(Elsevier Science Bv, 2016) Karatas, Yasar; Bulut, Ahmet; Yurderi, Mehmet; Ertas, Ilknur Efecan; Alal, Orhan; Gulcan, Mehmet; Zahmakiran, MehmetFormic acid (HCOOH) has recently been suggested as a promising hydrogen carrier for fuel cell applications. However efficient hydrogen production through the decomposition of formic acid in the absence of additives under mild thermodynamic conditions constitutes a major challenge because of the ease poisoning of active metals with CO formed as intermediate during formic acid decomposition. Recently, we have reported (App. Catal. B: Env. 164 (2015) 324) our discovery that the separately nucleated MnOx nanoparticles act as CO-sponge around catalytically active Pd nanoparticles exist on the same support and enhances both the activity and CO-resistivity of Pd nanoparticles. Using this important finding, herein, we present a new catalyst system consists of the physical mixture of PdAu alloy and MnOx nanoparticles supported on amine-grafted silica (PdAu-MnOx/N-SiO2) for the room temperature dehydrogenation of formic acid in the absence of any additives. PdAu-MnOx/N-SiO2 catalyst was simply prepared by deposition-reduction technique in water at room temperature with high reproducibility and characterized by the combination of various spectroscopic tools including ICP-OES, P-XRD, DR/UV-vis, XPS, BFTEM, STEM-EDX, STEM-line analysis and CO-stripping voltammetry techniques. The sum of their results shows that the formation of physical mixture of PdAu alloy and MnOx (dmean=2.2 nm) nanoparticles on the surface of support material. This new catalytic material facilitates the hydrogen liberation through the additive-free formic acid dehydrogenation at room temperature with previously unprecedented activity (TOF=785 mol H-2 mol catalyst(-1) h(-1)), converging to that of the existing state of the art homogenous catalysts. This new superior catalytic system enables facile catalyst recovery and very high stability against agglomeration, leaching and CO poisoning, which make it highly reusable catalyst (retains >92% activity and 85% conversion at the 5th catalytic reuse) in the additive-free formic acid dehydrogenation at room temperature. (C) 2015 Elsevier B.V. All rights reserved.
