Sharif Digital Repository

Nickel-dimethylglyoxime complex (NiDMG) modified nickel electrode (Ni/NiDMG) showed a catalytic activity towards methanol oxidation in NaOH solution. The modified electrode prepared by the dimethylglyoxime anodic deposition on Ni electrode in the solution containing 0.20 mol L-1 NH4Cl + NH4OH (pH 9.50) and 1.0 × 10-4 mol L-1 dimethylglyoxime. The modified electrode conditioned by potential recycling in a potential range of 100-700 mV (vs. SCE) by cyclic voltammetry in alkaline medium (0.10 M NaOH). The results show that the NiODMG film on the electrode behaves as an efficient catalyst for the electrooxidation of methanol in alkaline medium via Ni(III) species formed on the electrode with the... 

One of the main challenges in arid and semi-arid regions is the lack of water for various purposes such as industrial and agricultural applications. The problem is even more significant in traditional agriculture. The geographical location, climatic conditions, average annual rainfall, vegetation, air pollution and turbidity, and canopy of plants are important and lead to different water consumption in plants. Therefore, proper water consumption in agriculture in most countries leads to food security and a better supply of crops. In this research, we propose a fuzzy system that has eight inputs and seven outputs. Inputs include soil moisture, relative humidity, air temperature, wind speed,... 

In this research, synthesis of lanthanum oxide nanoparticles using supercritical water as a reaction medium in batch type reactor was studied. The crystallographic identity and morphology of the synthesized nanoparticles were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns indicate that the well-crystallized lanthanum oxide nanocrystals can be easily obtained under the current synthetic conditions. The effect of four parameters includes temperature, reaction time; primary concentration of aqueous solution of lanthanum (III) nitrate and pH of starting solution on reaction efficiency, particle size and the BET surface area were investigated... 

Many research works have been done in face recognition during the last years that indicates the importance of face recognition systems in many applications including identity authentication. In this paper we propose an approach for face recognition which is suitable for unconstrained image acquisition and has a low computational cost. Since in practical applications such as in smartphones, imaging conditions are not limited to existing images in the database, robustness of the recognition algorithm is very important. Here a sparse representation framework is proposed which achieves some degree of robustness. Using double sparse representation the high computational cost of sparsity-based... 

Radiation-induced multiple event transients (METs) are expected to become more frequent than single event transients (SETs) at nanoscale CMOS technology nodes. In this paper, a fast and accurate layout-based soft error rate (SER) assessment technique with consideration of both SET and MET fault models is presented. Despite existing techniques in which the adjacent MET sites are extracted from a logic-level netlist, we conduct a comprehensive layout analysis to obtain MET adjacent cells. Experimental results reveal that the layout-based technique is the only viable solution for identification of the adjacent cells as netlist-based techniques considerably underestimate the overall SER.... 

Frequent instruction cache (L1-I) misses pose a significant performance bottleneck in modern processors, especially for applications with large instruction footprints, such as server applications. To address the L1-I misses, there have been various proposals for L1-I prefetching over the past two decades. The designers of L1-I prefetchers primarily focused on enhancing performance while minimizing the area overhead. However, they paid little attention to the resulting increase in energy consumption due to incorporating an L1-I prefetcher. Furthermore, prior works assume L1-I prefetcher's energy consumption is mainly due to its area overhead. In this work, we demonstrate that a substantial... 

Electrocatalytic oxidation of methanol on a nickel disc electrode coated with nickel dimethyglyoxime complex (NiDMG), conditioned by potential recycling in a potential range of 100-700 mV (versus SCE) is studied by cyclic voltammetry in alkaline medium (0.10 M NaOH). The results show that the NiODMG layer formed at the surface of electrode behaves as an efficient electrocatalyst for the oxidation of methanol in alkaline medium via Ni(III) species with the cross exchange reaction occurring through out the layer at a low concentration of methanol. A plausible mechanism was proposed for catalytic oxidation of methanol at this modified electrode. Moreover, the effects of various parameters such... 

In this paper, we propose a very fast analytical approach to measure the overall circuit Soft Error Rate (SER) and to identify the most vulnerable gates and flip-flops. In the proposed approach, we first compute the error propagation probability from an error site to primary outputs as well as system bistables. Then, we perform a multi-cycle error propagation analysis in the sequential circuit. The results show that the proposed approach is four to five orders of magnitude faster than the Monte Carlo (MC) simulation-based fault injection approach with 92% accuracy. This makes the proposed approach applicable to industrial-scale circuits  

A different approach in the calculation of two-dimensional local density of states has been presented for a two-dimensional finite rectangular-lattice photonic crystal with a separable profile of permittivity. Approximate staircase structures are already shown to be useful for their ability to reproduce actual properties of practical square lattice photonic crystals. Using the effective resonance approach in a Fabry-Perot resonator and transfer matrix method an analytical expression for calculating a two-dimensional local density of states can be derived for both polarisations in the structure. It is shown that for this geometry one can resolve the modes as a product of two separate... 

Patterns formed by the flow of an inhomogeneous fluid (suspension) over a smooth inclined surface were studied. It was observed that fractal patterns are formed. There exists a threshold angle for the inclination above which global fractal patterns are formed. This angle depends on the particle size of the suspension. We observed that there are two fractal dimensions for these patterns, depending on the area from which the pattern is extracted. If the pattern is taken from the top which only consists of the beginning steps of the pattern forming, one finds two fractal dimensions, i.e. 1.35-1.45 and 1.6-1.7, in which the first one is dominant. And if the entire pattern is taken, then fractal... 

Patterns formed by the flow of an inhomogeneous fluid (suspension) over a smooth inclined surface were studied. It was observed that fractal patterns form. There exists a threshold angle for the inclination above which global fractal patterns are formed. This angle depends on the particle size of the suspension. We observed that there are two fractal dimensions for these patterns, depending on the area from which the pattern is extracted. If the pattern is taken from the top which only consists of the beginning steps of the pattern forming, one finds two fractal dimensions, i.e. 1.35-1.45 and 1.6-1.7, in which the first one is dominant while, if the entire pattern is taken, then a fractal...