Browsing by Author "Kivrak, H.D."

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Carbon Nano Tube Assisted Triple Metal Electrode and High-Impact Electro Sensor for Preservative Detection in Food Samples
(Taylor and Francis Ltd., 2024) Yayla, M.; Çelik Kazıcı, H.; Kivrak, H.D.
In this study, the electrode surface was modified with ternary metal supported by carbon nanotubes and for this purpose, PdRuCr-based sensor was developed that determines the preservatives in different food. The surfaces electronic and chemical properties were determined by methods such as SEM-EDX (scanning electron microscopy, Energy-Emitting X-ray analysis) and XRD (X ray diffraction). The activities of the electrocatalyzers were carried out using electrochemical measurements such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. The lowest limit ranges (LOD) were determined. For benzoic acid (BA) and potassium sorbate (PS), the specification limit values of the sensors were calculated as 0.82 µM (0.1 mgL−1 in ppm) and and 11.9 µM (1.78 mgL−1 in ppm) respectively. The sensitivity of the sensor was calculated as 1123,944 µA/mM.cm2 for BA and 2363,38 µA/mM.cm2 for PS and linear concentration range were determined as 2.5–200 µM for BA and 35–140 µM for PS, respectively. © 2023 Informa UK Limited, trading as Taylor & Francis Group.
Direct Formic Acid and Formate Fuel Cells (Df
(Elsevier, 2020) Ulas, B.; Kivrak, H.D.
Among the direct liquid fuel cells, the direct methanol fuel cells (DMFCs) are the fuel cells closest to commercialization. However, direct formic acid fuel cells (DFAFCs) and direct formate fuel cells (DFFCs) are also promising energy conversion devices for portable applications. It is important to choose the appropriate anode catalyst, cathode catalyst and membrane to achieve high power density for these fuel cells. In particular, the mechanisms of reactions at the anode side are extensively studied by researchers. In this chapter, the mechanisms of the reactions taking place at the anode and cathode sides, and the reported anode catalysts for DFAFC and DFFC in recent years are presented. © 2021 Elsevier Inc. All rights reserved.
Introduction To Other Organic Fuel-Based Fuel Cells
(Elsevier, 2020) Ulas, B.; Kivrak, H.D.
Fuel cells are good alternative energy conversion systems that convert chemical energy directly into electrical energy to meet energy needs in the near future. Among the direct liquid fuel cells, direct alcohol fuel cells (DAFCs) are the widely studied organic-based fuel type; however, there are also other organic-based fuels that have a wide potential for use in fuel cells. Direct formic acid fuel cells (DFAFCs), direct dimethyl ether fuel cells (DDMEFCs), and direct formate fuel cells (DFFCs) are of interest to researchers because of their particular characteristics. These fuel cells have an important advantage in terms of storage and transportion compared to hydrogen-fed polymer electrolyte fuel cells (H2-PEMFC) similar to other DLFCs. While formic acid is preferred due to its high energy density, DME and formate attract attention with their low fuel crossover and high electrooxidation kinetics. This chapter gives an overview particularly of DFAFC, DFFC, and DDMEFC technology and stresses the barriers to commercialization of these types of fuel cells. © 2021 Elsevier Inc. All rights reserved.