A straightforward one-pot synthesis of Pd–Ag supported on activated carbon as a robust catalyst toward ethanol electrooxidation

Direct Ethanol Fuel Cells (DEFCs) have fascinated remarkable attention on account of their high current density and being environmentally friendly. Developing efficient and durable catalysts with a simple and fast method is a great challenge in the practical applications of DEFCs. To this end, the bimetallic Pd–Ag with adjustable Pd:Ag ratios were synthesized via a simple and one-pot strategy on activated carbon as a support in this study. The Pd–Ag/C catalysts with different molar ratios were synthesized by simultaneous reduction of Pd and Ag ions in the presence of the ethanolic sodium hydroxide as a green reducing agent for the first time. Several different methods, including FE-SEM, HR-TEM, XRD, XPS EDX, ICP-OES, and BET were used to confirm the structure and morphology of the catalysts. The performance of catalysts was also examined in ethanol oxidation. Obtained results of electrochemical experiments revealed that the Pd₃–Ag₁/C catalyst had superior catalytic activity (2911.98 mAmg^?1_Pd), durability, and long-stability compared to the other catalysts. The excellent catalytic characteristic can be attributed to the synergistic effect between Pd and Ag. We presume that our simple method have the chance to be utilized as a proper method for the synthesis of fuel cell catalysts.     

Physical layer impairment-aware shared path protection in wavelength-routed optical networks

The Journal of Supercomputing - In this paper, physical layer impairment (PLI)-aware shared path protection (SPP) scheme for single-link failures in transparent optical WDM mesh networks is...     

An Experimental Investigation on the Effect of Cooling Rate During Combined Continuous Casting and Rolling Process on Mechanical Properties of 7075 Aluminum Alloy

When a combined continuous casting–rolling (CCCR) process is employed for making Al plates and sheets, considerable savings in both the cost and the production time are attained. In the present research, the variation and control of temperature of the material flowing through the cooling jacket during CCCR of 7075 aluminum alloy were investigated. Employing three temperature profiles for this passage, it was shown that the best mechanical properties and grain size of the finally rolled product could be attributed to the exponential profile. It was also found through a heat transfer analysis that the difference in the free convection heat transfer from the top and bottom surfaces of the slab exiting the cooling jacket can result in a temperature gradient through the thickness of the plate, and this can consequently lead to certain variations in the hardness through the thickness of the finally rolled 7075 Al plate.     

The interaction of dental cements with aqueous solutions of varying pH

A study is reported in which a series of dental cements of varying types (zinc phosphate, zinc polycarboxylate, glass-ionomer and resin-modified glass-ionomer) was exposed to aqueous solutions of differing pH for time intervals of a week, after which the pH of the storage solutions was determined. The results showed that all of the acid-base cements altered the pH of their storage solution, regardless of whether that initial solution was weakly acidic, weakly alkaline or close to neutral. All cements were found to act as buffers, because they not only increased the pH of the weakly acidic lactic acid solution, but they also decreased the pH of the weakly alkaline artificial saliva. In deionized water, the zinc polycarboxylate generally increased pH, while all other cements reduced it. In all cases, these results were shown to be repeatable on exposure to fresh-aqueous solutions of the appropriate pH for a further week, such experiments being carried out for up to six weeks. In terms of mass change, in most solutions, there was a modest increase during the first week, after which the mass remained steady. In lactic acid, zinc phosphate and zinc polycarboxylate cements showed a gradual reduction in mass throughout the six weeks, whereas the glass-ionomers showed an initial increase, followed by a much slower decrease in mass. These results confirm that glass-ionomers are the most resistant of the cements towards acid erosion.     

Modeling of thermodynamic properties of carrot product using ALO,GWO, and WOA algorithms under multi-stage semi-industrial continuous belt dryer

Engineering with Computers - In this paper, multi-stage continuous belt (MSCB) dryer was used for carrot slices drying. Experiments were performed at three air speeds (1, 1.5, and 2 m/s)...     

Enhanced sensitivity of cancer cell using one dimensional nano composite material coated photonic crystal

We theoretically analyze the detection of a cancer cell in the one-dimensional photonic crystal by infiltrating different sample cells in the cavity layer. The defect modes appear in their transmission spectra only if the nanocomposite layers are included on either side of the cavity layer. This analysis is carried out by a dielectric constant and the transmittance peak of the cancer cell is compared with the normal cell. The transmittance peak shifts are analyzed with various filling factors for optimization purposes. Through the shifting spectrum, the sensitivity of cancer cell from the normal cell is obtained from a minimum of 42 nm/RIU to a maximum of 43 nm/RIU.

     

Microstructure and Optical Bandgap of Cobalt Selenide Nanofilms

Semiconductors - The purpose of this research is to explore the properties of CoSe nanostructured thin films on glass substrates prepared by a chemical solution deposition method. Special attention...     

On the resilience of P2P botnet footprints in the presence of legitimate P2P traffic

Botnet is a distributed platform for illegal activities severely threaten the security of the Internet. Fortunately, although their complicated nature, bots leave some footprints during the C&C communication that have been utilized by security researchers to design detection mechanisms. Nevertheless, botnet designers are always trying to evade detection systems by leveraging the legitimate P2P protocol as C&C channel or even mimicking legitimate peer‐to‐peer (P2P) behavior. Consequently, detecting P2P botnet in the presence of normal P2P traffic is one of the most challenging issues in network security. However, the resilience of P2P botnet detection systems in the presence of normal P2P traffic is not investigated in most proposed schemes. In this paper, we focused on the footprint as the most essential part of a detection system and presented a taxonomy of footprints utilized in behavioral P2P botnet detection systems. Then, the resilience of mentioned footprints is analyzed using three evaluation scenarios. Our experimental and analytical investigations indicated that the most P2P botnet footprints are not resilient to the presence of legitimate P2P traffic and there is a pressing need to introduce more resilient footprints.     

Dual-wavelength transmission system using double micro-resonator system for EMI healthcare applications

Microsystem Technologies - To meet the 5G requirements for higher bandwidth, the focus has been shifted to millimeter waves paving the way to radio over fiber (RoF) in order to minimize radio...