794 research outputs found

    A fuzzy clustering model of information appliance

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    The purpose of this study is to propose a fuzzy clustering model of information appliances (IA). There are two sub-models, saying information appliance cluster engine (IACE) and user interactive model (UIM), in this model. The function of IACE is to process the users’ recognitions of IA devices. The UIM is the interface of IACE with the IA intelligent agents (IAIA). Via the proposed model, the IAIA can be more humanistic, and convenient for user. Also, via the implementation of this model, we can have the analysis of the optimal effectiveness

    FIRE RETARDANT BEHAVIOR OF KENAF FIBRE REINFORCED FLOREON COMPOSITE

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    According to the report, more than 41% of fatalities in flight were to find to be caused by fire. In recent years, composites used in aircrafts are carbon fibre/ glass fibre reinforced epoxy, due to light weights and high strength properties. However, these composites are known as highly flammable. Serious fire incident will be created in a short time after a spark of fire. Furthermore, ingredients for fibre and epoxies are, toxic and resulting in the release of toxic gases during fire, and cutting off fresh air to survivors and hindering their escape. In the meantime, biopolymers have attracted considerable attention due to their environmentally friendly and sustainable nature, Kenaf Fibre (KF) is one of the most famous natural fibre used as a reinforcement in Polymer Matrix Composites (PMC). Kenaf is also known as Hibiscus Cannabimus L., and is an herbaceous annual plant that is grown in a wide range of weather conditions, growing more than 3 meters within 3 months. However, the inherent drawbacks associated with Floreon (FLO) based composites include brittleness, lower strength and high moisture sensitivity, which in turn limit their application in the aircraft industry. In order to overcome such drawbacks, two modification techniques were employed in this study: (1) incorporated kenaf fibre into polypropylene polymer with magnesium hydroxide flame retardant and (2) reinforces kenaf fibre and magnesium hydroxide by different combination of volume. Consequently, KF reinforced FLO or polypropylene (PP) composites with magnesium hydroxide (MH) flame retardant specimens were successfully developed using extrusion followed by hot pressing. The increment of KF contents in PP composites had shown higher tensile modulus and decomposed mass loss at onset temperature, but lower values in tensile strength, elongation, flexural strength and onset temperature. In the meantime, 25 wt% KF contented PP composite shown a slightly higher flexural strength, while the higher volume of MH filler in composites caused lower strength, tensile modulus, elongation, but with higher onset temperature and the 2nd peak temperature in thermogravimetric analysis (TGA) testing. Furthermore, increasing the KF contents in PP matrix has found lower mass residue. However, increasing of KF contents in MH contented composite had increased the mass residue at the end of the testing. On the other hand, the increment of the melt flow properties (MVR and MFR) was found for the KF or MH insertion, due to the hydrolytic degradation of the polylactic acid (PLA) in FLO. The deterioration of the entanglement density at high temperature, shear thinning and wall slip velocity were the possible causes for the higher melt flow properties. In the meantime, increasing the KF loadings caused the higher melt flow properties while the FLO composites with higher MH contents created stronger bonding for higher macromolecular chain flow resistance, hence, recorded lower melt flow properties. However, the complicated melt flow behavior of the KF reinforced FLO/MH biocomposites was found in this study. The high probability of KF-KF and KF-MH collisions was expected and there were more collisions for higher fibre and filler loading, causing lower melt flow properties. Besides that, insufficient resin for fibre wetting, hydrolytic degradation on the biopolymer and poor interfacial bonding were attributed to low strength profile. Yet, further addition of KF increased the tensile strength and flexural. Nevertheless, inserting KF and MH filler have shown positive outcome on flexural modulus. Insertion of KF and MH showed the deterioration of impact strength, while the addition of KF increased the impact strength. Meanwhile, FLO is a hydrophobic biopolymer which showed only a little of total water absorption. In this regard, for the first 24 hours, the water absorption rates were high for all bio-composites. Hence, it is worth mentioning that the high contents of KF in bio-composites shown higher saturation period and higher total amount of water absorption while MH caused shorter saturation period but lower total amount of water absorption. However, interface bonding incompatibility has increased the water absorption of KF/FLO/MH composites. Moreover, some synergistic effect was located in char formation, Tg reduction and a lower tan δ peak shown in the three-phase system (KF/FLO/MH). The MH filler was found to be more significant in enhancing mass residual. The Tg were show deterioration for all samples compared to pure FLO biopolymer. The melting temperature has found no meaningful change for either insertion of KF or MH or both. The values of co-coefficient, C recorded decreasing as increasing the fibre loading. This showing the fibres transfer the loading effectively. As conclusion, although 10KF5MH specimen does not have the best performance in mechanical properties, a higher flame retardancy shall provide KF reinforced FLO composite with MH filler for more applications in advanced sector especially, in hazardous environment

    Interfacial debonding force and shear strength of sugar palm (Arenga pinnata) fiber reinforced composites by pull-out test

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    An experimental investigation was performed to understand the pulling out behaviour of sugar palm (Arenga pinnata) fibers from unsaturated polyester (UP) composites. The effect of embedded length on the fiber-matrix interface was studied. Fibers were treated with UP and phenol formaldehyde (PF). Untreated fibers were used as the control. Single fiber pull-out tests were carried out for 360 specimens to determine the debonding force and interfacial shear strength (IFSS). Significant increase in debonding force of untreated fiber and UP-impregnated fiber was observed from embedded length of 2 mm to 3 mm. However, no significant increase was observed for the embedded length of more than 3 mm. Debonding force showed remarkable improvement with ascending order of untreated fibers, PF-impregnated fibers, and UP-impregnated fibers. The optimum embedded lengths of untreated fibers and UP fibers were determined. Additional finding showed that the interfacial shear strength decreased as the embedded length increased. However, UP-impregnated fibers showed the highest IFSS value, followed by PF fibers and untreated fibers. Analysis using Scanning Electron Microscope (SEM) was also included to justify the result

    A Modification Artificial Bee Colony Algorithm for Optimization Problems

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    Simulation study for the compressed BMC materials of kenaf/coir reinforced unsaturated polyester: flow behaviour and the effects of charges shapes studies

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    This study provides predictable flow behavior of a hybrid biocomposites made from kenaf/coir reinforced unsaturated polyester using the Moldflow software. A medium size electrical part has been chosen as a mold having multi-wall thicknesses and complex surfaces. Three different shapes of charges of the bulk molding materials were used and compressed into the mold part. The shapes of charges would be rectangular, cubic and cylindrical shapes. The results showed that rectangular charge took 0.2 seconds to fill up the part while the cubic and the cylindrical charges took 1.911 and 2.898 seconds respectively. After 70 seconds the conversion at nodes was more than 98% for all charges. On the other hand, the final densities were 1.88 ± 0.08 g/cm3 for all charges. The cubic charges showed a better temperatures distribution at flow front followed by rectangular, the last being the cylindrical charge, and the average shrinkage was 5-7% for the charges. The cubic shape showed good fibers orientation to the flow direction of the bulk materials followed by cylindrical charge while the rectangular charge showed poor orientation of fibers affected on the deflections, weld lines and air traps in the internal part. For the rectangular, the charge showed more critical weld lines and more air traps especially on the surface of the molded part and more deflections on the corner edges. But, the cubic charge showed the lowest deflections rate, air traps and weld lines defects

    What determines misallocation in innovation? A study of regional innovation in China

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    This paper sounds an alarm about disparate efficiencies among China’s regions in the allocation of innovation inputs. A theoretical measure of misallocation is adopted to gauge the distortions that exacerbate the inefficiency of resource allocations across geographic innovation units; these units’ usage of innovative inputs reveals the level of misallocations prevalent within the Chinese economy. The measure of innovation misallocation is computed by utilizing a micro dataset based on information from the China Statistical Yearbook for Science and Technology (CSYST) from 1999 to 2012. In addition, this paper probes the factors that co-move with China’s innovation resource misallocations. We find that, although an advanced financial market is beneficial to innovation efficiency in China, both the government’s extensive development of transportation infrastructure and the preferential treatment given to state-owned enterprises (SOEs) and foreign-invested enterprises (FIEs) negatively correlate with innovation efficiency. We conclude that emerging economies that are experiencing R&D input expansion, such as China, should be cautious in ensuring efficient resource allocations

    Particleboard manufactured from rubberwood RRIM 2002 clone planted with different fertilizer treatment

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    This work focus on the effects of SRF (Slow Release Fertilizer) + NPK fertilizer rates on the properties of rubberwood particleboards produced. The particleboards were fabricated using rubber tree trial clone RRIM 2002. RRIM 2002 clone still in trial plot with age of 4-year old and classified as Latex Timber Clone which estimated to produce large wood volume and also better latex yield. The properties of particleboard were categorized and evaluated based on fertilizer treatment applied on RRIM 2002 clone tree: T1 (SRF + NPK at normal rate), T2 (SRF + 1.5 x NPK at normal rate), T3 (SRF + 2.0 x NPK at normal rate) and T4 (SRF + 2.5 x NPK at normal rate, control (NPK at normal rate). The resin used for particleboard fabrication was urea formaldehyde (UF) (63.9% solid) type E1. The resin content is 10%. The thickness of board is 10 mm with density 700 kgm-3. The particleboards were fabricated and assessed in accordance to Japanese Industrial Standard for Particleboard (JIS A 5908-2003). The properties that been assessed were on modulus of elasticity (MOE), modulus of rupture (MOR), internal bonding (IB), thickness swelling (TS) and water absorption (WA). From this study, it is found that fertilizer treatment influences the particle recovery and performance of particleboard especially on dimensional stability and internal bonding properties which significantly affected. The MOR and MOE of particleboard made from rubber trees that treated with SRF-NPK fertilizer showed better performance compared to that of with NPK fertilizer alone (control), however, the differences were not significant. In term of IB, no specific trend was observed. Lastly, for dimensional stability (TS and WA), particleboard produced from SRF-NPK fertilizer reduced the board stability when subjected to cold water soak

    Characterization Study of Empty Fruit Bunch (EFB) Fibers Reinforcement in Poly(Butylene) Succinate (PBS)/Starch/Glycerol Composite Sheet

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    In this study, a mixture of thermoplastic polybutylene succinate (PBS), tapioca starch, glycerol and empty fruit bunch fiber was prepared by a melt compounding method using an industrial extruder. Generally, insertion of starch/glycerol has provided better strength performance, but worse thermal and water uptake to all specimens. The effect of fiber loading on mechanical, morphological, thermal and physical properties was studied in focus. Low interfacial bonding between fiber and matrix revealed a poor mechanical performance. However, higher fiber loadings have improved the strength values. This is because fibers regulate good load transfer mechanisms, as confirmed from SEM micrographs. Tensile and flexural strengths have increased 6.0% and 12.2%, respectively, for 20 wt% empty fruit bunch (EFB) fiber reinforcements. There was a slightly higher mass loss for early stage thermal decomposition, whereas regardless of EFB contents, insignificant changes on decomposition temperature were recorded. A higher lignin constituent in the composite (for high natural fiber volume) resulted in a higher mass residue, which would turn into char at high temperature. This observation indirectly proves the dimensional integrity of the composite. However, as expected, with higher EFB fiber contents in the composite, higher values in both the moisture uptake and moisture loss analyses were found. The hydroxyl groups in the EFB absorbed water moisture through formation of hydrogen bonding
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