Applied Mechanics and Materials Vol. 679

Abstract: Research in speech recognition has produced different approaches that have been used for the classification of speech utterances in the back-end of an automatic speech recognition (ASR) system. As speech recognition is a pattern recognition problem, classification is an important part of any speech recognition system. This paper proposes a new back-end classifier that is based on artificial life (ALife) and describes how the proposed classifier can be used in a speech recognition system.

Abstract: The thermo-catalytic decomposition (TCD) of methane has attracted the attention of numerous researchers’ around the world as an ideal approach for hydrogen production, which in turns, can be used as an appropriate feeding gas in fuel cells operating at low temperatures. The TCD of methane is capable to produce a valuable by–product, pure carbon, which can excessively alleviate the total cost of the process. In this study, we report TCD of methane over 30% Ni supported Y zeolite catalyst at 550 and 600 °C was conducted in a fixed bed reactor and the yield of hydrogen from the reactor was analyzed by GC. As can be observed that, the TCD of methane over Ni-supported Y zeolite showed maximum conversion (31 and 15.90 % at 600 and 550 °C, respectively) at the initial stages and on stream of reaction time, it decreased gradually; and ultimately, deactivated the catalyst completely. The cause for this is the formation of encapsulating carbon on Ni active sites which deactivates the catalyst over the course of reaction time. Hydrogen production rate, carbon accumulation (CA) and carbon formation rate (CFR) were investigated at three representative times for both temperatures. The CFR analysis showed that the growth of filamentous carbon was steady-state at the first stage and then reduced to a relic activity and it remains constant during the rest of the reaction. The descriptive dissemination of methane TCD over Ni-supported Y zeolite has been speculated in this paper.

Abstract: In general, transformer is one of the most important equipment in the power system, the reliability of a transformer is commonly determined by its insulation condition. The insulation liquid that has been used for decades is petroleum based mineral oil which has a very good cooling performance. However, it is insidious to the environment. Hence, vegetable oils such as coconut oil and palm oil are used as the alternative to replace the mineral oil. In this paper, it presents the comparative studies from previous experiments on dielectric strength, moisture content, viscosity, pour point and flash point of both vegetable oils.

Abstract: The effect of recycled silicone catheter (rSC) on tensile properties (tensile strength, modulus at 100% elongation and elongation at break) and morphology of recycled silicone catheter filled epoxidised natural rubber (ENR 50/rSC) vulcanizates were studied in loading range of 0 to 50 phr with two different size; fine (300-600μm) and coarse (1-2 cm). For tensile properties, tensile strength, modulus at 100% elongation (M₁₀₀) and elongation at break (E_B) for both ENR 50/rSC fine and coarse vulcanizates show increment up to 15 phr but then decreased as the rSC content increased. Comparison between ENR 50/rSC fine and coarse vulcanizates indicates that ENR 50/rSC fine vulcanizates has better tensile properties than ENR 50/rSC coarse vulcanizates due to better dispersion and filler-rubber interaction as proven in morphological study. The results indicate that the morphology of ENR 50/rSC fine vulcanizate is better than that of ENR 50/rSC coarse vulcanizates in which fine rSC well bonded with ENR 50.

Abstract: Micromixer can be divided into two categories which are active micromixer and passive micromixer. Due to the simple fabrication technology and ease of implementation in a complex microfluidic system, obstacle-based passive micromixers will be the focus in this work. A passive micromixer is depends on low Reynolds number and the channel geometry for mixing effectiveness. In this work, three designs of obstacle based micromixer were designed and evaluated. These micromixers has 237μm channel length, 30μm inlet length, 900 between inlets ports, width and depth are 30μm each. The fluids used for mixing were blood which has 3.0 × 10-3 kg/μms of viscosity and glycerin which has high viscosity than blood (1.49 × 10-3 kg/μms). The fluids used to evaluate the differences in term of their visual performance based image’s standard deviation by plotting the graph and mixing efficiency by calculation. Based on these evaluations, the Y shape with meander structure obstacle design has the best mixing efficiency at the outlet of the channel.

Abstract: This paper reviews current literature in terms of the effect of slope walking on vertical pedestrian loading. In this review the gait style, gait parameters, and vertical pedestrian loading is reviewed. The reason why such a study was conducted is explained; and the force profiles from the authors own experimental studies are presented. From that study, two contrasting vertical force profiles exist; one for rigid walking and one for flexible walking; here possible reasons for such differences are explored.

Abstract: The effect of three different types of rice husk ash which distinguish by color, pink, grey and white ashes were used as admixture to ordinary Portland cement paste was studied. Six batches of cement paste was prepared by adding 0-50 wt % RHA. The chemical and mineralogical characteristics of RHA were first analyzed. The characteristic of cement paste was investigated using IR, TGA and XRD. Hydration temperature also recorded. Chemical analysis shows higher amount of silica in RHA which is in range of 95-98wt. %. XRD and IR confirmed the white RHA is amorphous silica. The optimum amount of RHA addition was 10 wt. % which produced comparable properties with cement paste control. Based on Calorimetery Studied, IR, TG and hydration temperature results, white silica was found the most reactive silica but plays limited role as admixture in OPC paste.Keywords: rice husk ash, ordinary Portland cement, cement paste, hydration temperature

Abstract: Malaysia has an abundance of renewable energy resources. However, the implementation proved to be difficult, as many factors have to be considered, mainly economical factor. Furthermore, currently there is no known framework to establish the feasibility study of renewable energy technology implementation. This paper serves as an initial study on the application of fit-viability framework for the implementation of RE technology, focussing in Malaysia. A simple case study has been performed based on the Feed-in Tariff mechanism, an the fit-viability framework proved to be useful in RE technology consideration.

Abstract: – This paper presents the comparison induced voltage between 0.35 mm and 0.50 mm thicknesses 3% SiFe (NG) with different frequency which are 45 Hz, 50 Hz and 60 Hz by using Single Sheet Tester (SST). This experiment used to measure the search coil voltage L1N1 and L2N2 at two positions (1st position and 2nd position) and harmonic content. The analysis shows, at different frequency for both thicknesses, the value of search coil voltage L1N1 is higher than the search coil voltage L2N2 for both positions. It shows the easy direction is single sheet tester direction at the 1st position for 0.35 mm and 0.50 mm thickness with different frequency. For harmonic content, at 0.6 T with different frequency for both thicknesses, the 3rd order harmonic factor of 0.35 mm is lower than 0.50 mm thickness 3% SiFe (NG). It is because the higher losses can increase the harmonic of the materials. It means that harmonic is affected by ingredient and thicknesses in core material.

Abstract: Different rotor bars type, lower in iron loss, total loss and thicknesses of steel sheets will increase the efficiency of the induction motor. In this paper, the 3-phase 0.5 Hp AC induction motor have been thoroughly investigated and analyzed in term of efficiency, torque, iron loss, total loss and loss field. The comparison is done by software simulation named MotorSolve (IM) that enable user to produces more design of induction motor with result in a short time. Based on simulation, it shows that the Round Bars (RO.B) have more efficient compared to Round Outer and Inner Bars (ROIB) type.