Sutherlandfitzpatrick8802

In this study, the effect by Iron with nickel-based catalyst for the combined steam and carbon dioxide reforming of methane was investigated. Fe-promoted and un-promoted Ni-Mg-Ce/γ-Al2O3 catalysts were prepared by co-impregnation and evaluated in a quartz fixed-bed reactor at H₂OCO₂CH₄ ratios of 0.911 and a temperature of 1073 K under atmospheric pressure. The physicochemical properties of the catalysts were investigated by N₂ adsorption-desorption, XRD, H₂-TPR, CO₂-TPD, TGA and FE-SEM. The iron-supported catalysts showed improved resistance to carbon deposition and suppressed sintering of nickel. As a result, NMC-Fe(5) showed the lowest coke and high stability over 70 h among all other catalysts.A Co₂MnSi Heusler alloy has been prepared by mechanical alloying (MA) method successfully using a mixture of elemental Co50Mn25Si25 powders. A two-phase mixture of amorphous phase and remaining Mn were obtained after 5 hours of MA without any evidence for the formation of Co₂MnSi alloys. The saturation magnetization of MA powders decreased with MA time due to the magnetic dilution by alloying with nonmagnetic Mn and Si elements to 48 emu/g after 5 hours of MA. On the other hand, a Co₂MnSi single phase was obtained by MA after 3 hours and subsequently heat treated up to 650 °C. X-ray diffraction result showed that the average grain size of Co₂MnSi Heusler alloys prepared by MA for 5 hours and heat treatment to be in the range of 85 nm. The saturation magnetization of Co₂MnSi Heusler alloys prepared by MA and heat treatment reached a maximum value of 112 emu/g for 5 hours MA sample. It was also observed that the coercivity of 5 hours MA sample annealed at 650 °C was fairly low value of 27 Oe.In this study, we investigated the electrochemical effects of morphological changes using BaSnO₃ (BSO) of various shapes (columns, hollow rods, spheres) as anode materials for Li-ion batteries. The BSOs were prepared by hydrothermal method and their electrochemical properties were evaluated using galvanostataic charge/discharge and CV test. As a results, columnar BSO exhibits the best electrochemical properties, as an inert material, BaO can contribute to Li storage because of higher electrical conductivity. This results suggest that the formation of column shape can lead to improved electrochemical properties as anode materials of secondary battery.Perovskite solar cells (PSCs) represent the third generation of solar cells that comprise a semiconductor electrode, a counter electrode, and an electrolyte. Perovskite solar cells (PSCs) have been comprehensively researched and led to an impressive improvement in a short period of time as cheaper alternatives to silicon solar cells due to their high energy-conversion efficiency and low production cost. Tin oxide (SnO₂) has attracted attention as a promising candidate for electron transport material of perovskite solar cells, because it can be easily processed by low annealing temperature and solution processing method. However, in the fabrication of SnO₂ electron transfer layer (ETL) via the conventional solution method, it is greatly difficult to increase the size of the substrate by the solution treatment method or to commercialize it. In this work, we report the photovoltaic characteristics of SnO₂ based electron transport layer for perovskite solar cells (PSCs) fabricated by the thermal-evaporation processing method. The deposited SnO₂ layer with the thermal evaporator is known to be not crystallographically stable. To solve this problem, we performed the annealing process at relatively low temperature (below 200 °C). As a result, we could confirm the optimum annealing temperature and we could demonstrate PSCs with thermally deposited SnO₂ as the compact electron transport layer through a low-temperature annealing process. It would contribute to new opportunities in commercialization and development of perovskite solar cells.We explore the effect of high-speed blade coating on electrical characteristics of conjugated polymer-based thin-film transistors (TFTs). As the blade-coating speed increased, the thickness of the polymer thin-film was naturally increased while the surface roughness was found to be unchanged. Polymer TFTs show two remarkable tendencies on the magnitude of field-effect mobility with increasing blade-coating speed. As the blade-coating speed increased up to 2 mm/s, the fieldeffect mobility increased to 4.72 cm²V-1s-1. However, when the coating speed reached 6 mm/s beyond 2 mm/s, the field-effect mobility rather decreased to 3.18 cm²V-1s-1. The threshold voltage was positively shifted from 2.09 to 8.29 V with respect to increase in blade-coating speed.Compared with conventional semiconductor quantum dots, hybrid SiO₂ coated CdTe QDs exhibited high stability, long fluorescent lifetime, high photoluminescence quantum yields, and well biocompatibility. In this paper, CdTe QDs with tunable PL from green to red emitting were prepared by an aqueous synthesis. A sol-gel process resulted in CdTe QDs coated with a hybrid SiO₂ shell contained CdS-like clusters to obtain red-shifted PL spectra, increased PL efficiency and high stability. The clusters were formed by the reaction of Cd2+ and S2- ions generated via the decomposition of thioglycolic acid. The clusters around CdTe cores created a core-shell structure which is very similar with traditional semiconductor core-shell QDs. After being coated with a hybrid SiO₂ shell, the PL of green-emitting naked CdTe QDs was red-shifted largely (~30 nm) while the PL of yellowemitting CdTe QDs revealed a small red-shifted (~20 nm). Furthermore, The PL of red-emitting naked CdTe QDs was red-shifted much small (less than 10 nm). This phenomenon is ascribed to the change of band gap of CdTe cores with sizes. The red-shift of PL spectra is attributed to the CdS-like clusters around the core rather than the thickness of the hybrid SiO₂ shell.Gas hydrates are nonstoichiometric nano-structured crystalline compounds which are stabilized by gas molecules incorporated in the cages made of hydrogen bonding of water molecules at suitable thermodynamic conditions. The gas hydrate as a technology has been successful for several potential applications in various engineering fields, such as, gas separation, carbon dioxide sequestration, gas storage and transportation, desalination of salt water and wastewater treatment. Recently, metal-based nanofluids are considered as interesting kinetic promoter candidates for accelerating formation of gas hydrates. Although organic-based kinetic promoters are widely studied for the rapid formation of gas hydrates, research of a new material system is still a challenge. In this study, Silver (Ag) nanofluids as kinetic promoter of sulfur hexafluoride (SF6) hydrate were prepared by electrical explosion of pure metal wire in deionized water. The kinetics of SF6 gas hydrates were evaluated with different concentration of Ag nanofluids at condition of 276 K and 0.7 MPa, respectively. The Ag nanofluids, as kinetic nano-prompter, showed excellent effect on the formation of SF6 hydrates.The most critical issue on flexible electronics such as organic solar cell, OLED, and flexible displays, is the protection of core active materials from the degradation by water and oxygen. The water vapor transmission rate (WVTR), the main characteristics of barrier films, is closely related to defect density in inorganic layers constructed in the film. In this study, a calcein fluorescent probe is used to examine the relationship between the water vapor transmission rate (WVTR) and the defect density of the film coated the inorganic oxide layer. By using the fluorescence characteristics of calcein dye molecules, the calcein can be used for the evaluation of water vapor transmission rate. The result shows that the defect density is linearly increasing with the water vapor transmission rate of barrier films. Furthermore, it is shown that the defect density is inversely proportional to the thickness of the inorganic layer of Al₂O₃. Based on these results, it is suggested that the defect density measurement of the inorganic layer can predict the water vapor transmission rate of the barrier film.Gold nanoparticles (AuNPs) can provide a simple, easy-to-use, inexpensive, at hand point-of-care (POC) fast to diagnose; however, AuNPs have the predisposition to form aggregations. Since the nanoparticles stability is an important issue, this article is aiming to study the long-term stability associated with the development of an immunosensor for clinical diagnosis. Here, we assessed two previous methods commonly described in the literature to prevent the formation of aggregate by studying pH and Tween® 20 (polysorbates) addition as surfactant. AuNPs were characterized through ultraviolet-visible (UV-Vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM) and through analysis in the ImageJ software. We found that the Tween® 20 provided more than stable condition in aqueous solution in comparison to pH dependence. The fabricated AuNPs were further used to detect dengue virus and demonstrating that its use at pH 7.2 did not maintain reproducibility in the detection of dengue virus after one year. Unlike, the Tween® 20 modified AuNPs that detected dengue virus soon after the synthesis and over the course of one year demonstrating the high sensitivity of immunosensor. Finally, our result showed excellent dispersity throughout the year when using Tween® 20 to avoid aggregation.Nanostructure materials are of interest in last few decades due to their unique size-dependent physio-chemical properties. In this paper, zinc oxide (ZnO) and barium doped ZnO nanodisks (NDs) were synthesized using sonochemical method and characterized by various techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), UV-vis absorption and dielectric measurements. The XRD and FTIR studies confirm the crystalline nature of ZnO NDs, and the average crystallite size was found to be ~25 nm for pure ZnO and ~22 nm for Ba doped ZnO NDs. SEM study confirmed the spherical shaped ZnO NDs with average sizes in the range of 20-30 nm. The maximum absorbance was obtained in the 200-500 nm regions with a prominent peak absorbance were observed by UV-vis spectra. The corresponding band gap for ZnO NDs and Ba doped ZnO NDs were calculated using Tauc's plot and was found to be 3.12 and 3.04, respectively. The conductivity and dielectric measurements as a function of frequency have been studied.g-C₃N₄ and graphene oxide (GO) are simultaneously introduced into electrospun polyacrylonitrile (PAN) nanofibers to form a nested structure. By Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), g-C₃N₄ has been perfectly introduced into the PAN@GO nanofiber membrane and affects the porosity of the fiber itself. check details Comparison of nested electrospinning PAN/PAN@GO and different proportions of PAN@g-C₃N₄/PAN@GO nanofibers has a different effect on reducing the concentration and absorption of rhodamine B (RhB) dye in the visible region. Combined with the advantages of g-C₃N₄ and GO and the performance of fibers in the photocatalytic process, the optimal nested PAN@g-C₃N₄/PAN@GO nanofibers were selected. These results indicate that the nested PAN@g-C₃N₄/PAN@GO nanofibers with high photocatalytic activity have great potential in the treatment of printing and dyeing wastewater.