Abstract: This article reports the first results on stress induced pseudo-Hall effect in single crystal n-type 3C-SiC(100) grown by LPCVD process. After the growth process, Hall devices were fabricated by standard photolithography and dry etching processes. The bending beam method was employed to study the stress induced changes in the electrical response of the fabricated Hall devices. It has been observed that when stress is applied to the 3C-SiC(100) Hall devices, the offset voltage of the Hall devices varies linearly with the applied compressive and tensile stresses which is called, the pseudo-Hall effect. The variation of the offset voltage of these Hall devices is also proportional to the applied input current. This variation of the offset voltage with the applied compressive and tensile stresses shows that single crystal n-type 3C-SiC(100) can be used for stress sensing applications.
Abstract: Polypyrrole (PPy) and manganese (Mn) due their remarkable properties offers a good performance for electrochemical capacitors. Manganese modified polypyrole (Mn-modified PPy) thin films were chronoamperometically (CA) deposited on the platinum-titanium crystal resonator as a part of the electrochemical quartz crystal microbalance (EQCM). The performances of the thin films were then examined for performance using cyclic voltammetry (CV). The effects of pyrrole monomer and manganese oxides concentrations were also investigated in this study.
Abstract: One of the coal combustion ashes is coal bottom ash. Low rank coal bottom ash can act as TiO2 catalyst’s support which was calcined at varying temperature, has been created. The low rank coal bottom ash model was collected from low rank coal which burned in muffle furnace at 800 °C for 2 h. Subsequently, the low rank coal bottom ash was impregnated with titanium (IV) isopropoxide (Ti (PrO)4) 500 μmol, and then calcined at variation temperature of 300, 400, 500, 600 and 700 °C. The modified physiochemical property of catalysts were determined UV-vis spectroscopy, N2 adsorption-desorption and hydrophobicity test. The performances of the catalysts were tested for styrene oxidation with H2O2 aqueous as oxidant. It is found that the low rank coal bottom ash was as good catalyst support, whereby TiO2 supported low rank coal bottom ash which calcined at 400 °C possessed the best catalytic activity with styrene conversion 45% and selectivity 87%.
Abstract: For organic solar cells (OSC) such as dye-sensitized cell (DSSC) to compete with silicon-based cells in terms of stability, there is a need to further improve components which causes degradation. To answer the stability issue with liquid electrolyte, solid state dye-sensitized solar cell (SS-DSSC) was introduced. SS-DSSC promises performance consistency due to less power degradation compared to standard DSSC that uses liquid-based electrolyte. Pentacene (PEN), a semiconductor usually used on field-effect transistors is a material that has a higher hole and electron mobility when compared to amorphous silicon and also has a band gap suitable for solar energy conversion. In this study, PEN used as hole transporting layer in SS-DSSC was fabricated through spin coating and heating using a precursor and through vapour transport using powder. The PEN samples were then doped with bromine through different methods - immersion and vaporization. Characterization of the PEN samples through X-ray Diffraction, Energy Dispersive X-ray Fluorescence, and Atomic Force Microscopy reveal orthorhombic, thin film, and crystalline bulk phases present on different fabricated PEN samples as well as confirmed successful doping. Furthermore, the light harvesting parameters are analysed through SolarTM Light LS1000 Solar Simulator (AM 1.5, 100 mW/cm2) which confirm correlation between the increased efficiency, PEN layer growing methods, and bromine doping methods.
Abstract: A study on the refining of nickel sulfate solution from sulfuric acid leached solution of spent lithium ion battery and fabrication of nickel nanopowders from the nickel sulfate solution was investigated. the nickel sulfate solution with high purity (>99.9%) was refined by precipitation method and solvent extraction method. the nickel nanopowders were synthesized by liquid phase reduction method with hydrazine and sodium hydroxide. the purity of nickel sulfate solution and nickel nanopowders were measured by EDTA(ethylenediaminetetraacetic) titration method with ICP-OES(inductively coupled plasma optical emission spectrometer). morphology, particle size and crystal structure of the nickel nanopowder was observed using transmission electron microscopy and x-ray diffraction spectroscopy.
Abstract: The electrochemical properties of carbon-coated FeS2 were investigated as a positive electrode material for lithium secondary batteries. The carbon-coated FeS2 powders were synthesized by ball-milling using polyaniline as the carbon source. The particles in the carbon-coated FeS2 samples were smaller than those in the pristine FeS2 samples. The electrochemical performance, including capacity, of these batteries was improved by carbon-coating by ball-milling. However, the initial coulombic efficiency decreased because of the reduction of the oxidized products on FeS2 surface. The reduction in particle size provides a larger contact area for the electrolyte. Larger quantities of oxidation products were formed by the reduction of FeS2 in the presence of air and water after carbon-coating. Therefore, the poor initial coulombic efficiencies of carbon-coated FeS2 electrodes were caused by the reduction of the oxidized products on the FeS2 surface.
Abstract: In this paper, we propose and experiment the application of self-cleaning Nano coating on solar panels. We have measured an important increase of water droplet contact angle on a Nano coated surface. We found beneficial effects on light transmittance and Open Circuit Voltage (Voc) for the photovoltaic modules. Experimentally, we have shown a higher Transmission coefficient (T) in case of treated glass. In addition, from Thermal Camera analysis, we have shown that the Nano coated Photovoltaic module became cooler and cleaner comparatively to untreated module.
Abstract: In this study, esterification of lactic acid and ethanol to produce ethyl lactate using different cation-exchange resin catalysts was performed at 100 °C. The catalysts used for the esterification process were amberlyst 16 and dowex 50W8x cation-exchange resins. Two simplified mechanisms based on Langmuir-Hinshelwood model were employed to describe the components that adsorbed most on the surface of the catalysts. Fourier Transform Infrared (Nicolet iS10 FTIR) was employed to verify the rationality of the mechanisms. FTIR of the esterification product reflected C=O, H=O and C=C bonds on the spectra confirming water and ethanol as the most adsorbed components. The kinetic study of the retention time and the peak areas of the esterification produced with the different catalysts were compared using an autosampler gas chromatography/mass spectrometry (autosampler GC-MS). The chromatogram of the esterification product catalysed by amberlyst 16 showed a faster elution at 1.503 mins with the peak area of 1229816403 m2 in contrast to the dowex 50W8x. The BET surface area and BJH pore size distribution of the resin catalysts were determined using liquid nitrogen adsorption (Quantachrome, 2013) at 77 K. The BET surface area results of amberlyst 16 resin catalysts was found to be 1.659m2/g compared to 0.1m2/g for the dowex 50W8x. The BJH results of the catalysts exhibited a type IV isotherm with hysteresis confirming that the materials were mesoporous with pore size in the region of 2 – 50 nm.
Abstract: Shuttle tankers are becoming more widely used in deep water installations as a means of transporting crude oil to storage plants and refineries. The emissions of hydrocarbon vapours arise mainly during loading and offloading operations. Experiments have been carried out on the use of polyurethane/zeolite membrane on an alumina support for the separation of methane from carbon dioxide and oxygen. The physical properties of the membrane were investigated by FTIR. Single gas permeation tests with methane, propane, oxygen and carbon dioxide at a temperature of 293 K and pressure ranging from 0.1 to 1.0 x 10-5 Pa were carried out. The molar flux of the gases through the membrane was in the range of 3 x 10-2 to 1 x 10-1 molm-2s-1. The highest separation factor of CH4/CO2 and CH4/O2 and CH4/C3H8 was determined to be 1.7, 1.7 and 1.6 respectively.