Dual Reinforcement Research Articles

Dual Reinforcement Effect of Nanoclay and Jute Fiber on the Mechanical Properties of Polyester Resin

The research work aims in analysing the effect of minimal loading of nanoclay in altering the mechanical properties of jute fiber reinforced polyester (JFRP) composites. Nanoclay content of 0.5 Wt.% has been constantly maintained for polyester composites containing 5 and 7.5 Wt.% jute fibers. Nanoclay was incorporated in polyester resin by magnetic stirring at 80°C for 3 hours. Further, the JFRP composites were fabricated by a conventional method known as hand lay-up method. Nanoclay filled polyester-jute fiber composites showed enhancement in tensile, flexural, impact strength and modulus of elasticity compared to pure, fiber reinforced polyester and nanoclay filled resin. Uniform distribution of nanoclay in the polyester matrix may form a strong physical interaction at the interface between the fiber and matrix. Surface morphology of the tensile fractured surface viewed through scanning electron microscopy (SEM) proved less fiber pull-out due to presence of nanoclay.

Effect of Ceramic Content on the Compression Properties of TiB2-Ti2AlC/TiAl Composites

In situ synthesized TiB2-reinforced TiAl composites usually possess high strength. However, it is very expensive to use B powder to synthesize TiB2 particles. Moreover, the strength enhancement of TiB2/TiAl composite is generally at the cost of plasticity. In this study, in situ dual reinforcement TiB2-Ti2AlC/TiAl composites were fabricated by using B4C powder as the B and C source, which greatly reduces the potential production cost. The 6 vol. % TiB2-Ti2AlC/TiAl composite fabricated by using the Ti-Al-B4C system shows greatly improved compressive properties, i.e., 316 MPa and 234 MPa higher than those of TiAl alloy and with no sacrifice in plasticity.

Microstructure and erosion wear of LM-13 alloy composites with dual reinforcement by silicon carbide and zircon sand in fine silica quartz slurry

Microstructure and erosion wear of LM-13 alloy composites with dual reinforcement by silicon carbide and zircon sand in fine silica quartz slurry

Adaptive load balancing in learning-based approaches for many-core embedded systems

Adaptive routing algorithms improve network performance by distributing traffic over the whole network. However, they require congestion information to facilitate load balancing. To provide local and global congestion information, we propose a learning method based on dual reinforcement learning approach. This information can be dynamically updated according to the changing traffic condition in the network by propagating data and learning packets. We utilize a congestion detection method which updates the learning rate according to the congestion level. This method calculates the average number of free buffer slots in each switch at specific time intervals and compares it with maximum and minimum values. Based on the comparison result, the learning rate sets to a value between 0 and 1. If a switch gets congested, the learning rate is set to a high value, meaning that the global information is more important than local. In contrast, local is more emphasized than global information in non-congested switches. Results show that the proposed approach achieves a significant performance improvement over the traditional Q-routing, DRQ-routing, DBAR and Dynamic XY algorithms.

Effect of dual reinforced ceramic particles on high temperature tribological properties of aluminum composites

Abstract The nature and distribution of hard ceramic particles in composite materials influences the properties to greater extent. In the present work, the role of hard ceramic reinforced particles on the tribological behaviour of aluminum metal matrix composites consisting of single (SRP) and dual reinforced particles (DRP) is studied at different temperatures. Zircon sand and silicon carbide particles of size 20–32 μm were used as reinforcement in commercial grade LM13 piston alloy. Composites of dual reinforced particles in aluminum matrix (DRP-AMCs) were developed by mixing 15 wt% reinforced particles by two step stir casting technique. The wear behaviour of DRP-AMCs and SRP-AMCs (single reinforced particles aluminum matrix composite) was investigated using a pin-on-disc method at high temperatures under dry sliding condition. The microstructural examination of developed composites shows globular and finely distributed eutectic silicon in the vicinity of the reinforced particles. Metallographic investigation revealed that the wear zone of the SRP composite consisted of a hardened layer, which is responsible for high wear loss observed in the SRP composite. The results further indicate a transition in the wear mode that occurs after 150 °C for all composites. Study reveals that the dual reinforcement of particles enhances the wear resistance as compared to single reinforced particles if mixed in a definite ratio. A combination of 3% zircon sand and 12% silicon carbide particle reinforced composite exhibits better wear resistance as compared to other combinations at all the temperatures for low and high loads both.

Microstructural and wear behavior of dual reinforced particle (DRP) aluminum alloy composite

The present investigations are a comparative study of single and dual reinforcement particles on microstructural features and wear behavior in LM-13 aluminum–silicon alloy. Silicon carbide and zircon sand particles of 20–32 μm are reinforced in the alloy by two-step stir casting method. Wear study reveals that the dual particle reinforcement enhances the wear resistance as compared to single particle reinforcement if mixed in a definite proportion. Study also indicate that a combination of 15 % reinforcement of zircon sand and silicon carbide particles in the ratio of 1:3 into the composite exhibits better wear resistance as compared to other combination.

Hybrid bio-composite from talc, wood fiber and bioplastic: Fabrication and characterization

This investigation deals with the development of hybrid composites from wood fiber, talc and a bioplastic i.e., polyhydroxybutyrate-co-valerate (PHBV) using the extrusion–injection molding. Synergistic improvement in the mechanical properties of PHBV–wood fiber composites were obtained with the additional reinforcement of micro sized talc in it. The compositional design of hybrid green composites primarily focuses to create a balance among the cost effectiveness, the environment friendliness and the characteristics of the hybrid composites. The hybrid green composites showed a pronounced leap of 200% in the Young’s and flexural modulus with the dual reinforcement of 20 wt.% talc and 20 wt.% wood fiber in PHBV matrix. The dynamic-mechanical and thermo-mechanical properties of the composite were experimentally determined and show similar trend. The theoretical reasoning based on the surface energy parameters of the interacting components in the composite is elaborated to explain the reinforcing effect of talc and wood fiber. The Morphological analysis of the hybrid composite was carried out using the scanning electron microscopy (SEM), to study the interfacial interactions among the different components in the hybrid composite. The quantitative decrease of 36% in coefficient of linear thermal expansion, and the improvement in heat deflection temperature of the hybrid composite was also observed. This investigation was based on the structure–property-processing, co-relationships of the three components in order to obtain hybrid composites.

Effect of Dual Reinforcement on Wear Resistance by Aluminum Compacts Reinforce by SiC, Al2O3

Effect of Dual Reinforcement on Wear Resistance by Aluminum Compacts Reinforce by SiC, Al2O3

PP/LCP composites: effects of shear flow, extensional flow and nanofillers

PP/LCP composites moulded under shear flow and extensional flows were prepared in this work. It was observed that the predominating shear flow during injection moulding was unable to induce in-situ reinforcements in the Rodrun LC5000/PP blend. With the introduction of an additional drawing process, fibrous LCP was developed. The fibrillation of the LCP phase was found to increase with the draw speed and the formation of LCP fibrils was manifested as higher strength and stiffness. However, due to the poor adhesion between the pre-generated LCP fibrils and PP matrix, the strength of the extensional PP/LCP composites was lower than that of direct injection moulded LCP/PP blend. In another approach, silica fillers were introduced to the LCP/PP blend and the LCP fibrillation was found to improve. The nanosilica was believed to behave as a viscosity thickening agent and was able to promote the LCP droplet-fibril transition effectively. The nanofiller/LCP/thermoplastic system possessed dual reinforcements which imparted good properties to the composite.

Algoritmo de roteamento adaptativo para o balanceamento de carga em redes de telecomunicações

Este trabalho apresenta um algoritmo de roteamento adaptativo, denominado Agentes-Q, baseado na integração de três estratégias de aprendizagem combinadas com alguns mecanismos para aumentar sua velocidade de adaptação. As três estratégias são: aprendizagem-Q, aprendizagem por reforço dual e aprendizagem baseada no comportamento de colônias de formigas. O algoritmo proposto é composto por um conjunto de agentes móveis simples, que se comunicam indiretamente e cooperam na busca dos melhores caminhos na rede. Os agentes selecionam as rotas de forma distribuída e atualizam incrementalmente as informações utilizadas na escolha dos caminhos. Agentes-Q foi aplicado a uma rede telefônica da British Telecom e a porcentagem média de chamadas perdidas por ele foi comparada a de dois algoritmos baseados no comportamento de colônias de formigas. Os experimentos envolveram variações nos padrões de tráfego, nível de carga e topologia da rede e a utilização de ruído na informação usada na seleção das rotas. Agentes-Q obteve melhor desempenho que seus competidores, apresentando maior capacidade de adaptação às situações consideradas.

外的・自己強化の二重強化における学習効果と消去抵抗について

Learning and resistance to extinction in external-self dual reinforcement (ESR) were compared with those in external reinforcement (ER). delta ESR (delta: extinction process) was also compared with the corresponding process of other two conditions; 1) discontinuation of self reinforcement after external-self dual reinforcement (delta SR), 2) discontinuation of external reinforcement following the dual reinforcement (delta ER). Undergraduates (n = 58 in Experiment I, n = 74 in Experiment II) were randomly assigned to one of the four conditions. Subjects were given association learning in Exp. I and memory task in Exp. II, respectively. Those who responded successfully were then shifted to extinction session for testing. Effects of ESR on learning were same as those of ER in the two experiments. Resistance to extinction in Exp. I was significantly higher for delta SR and delta ESR as compared with delta ER and *ER (extinction switched from external reinforcement). Resistance for delta SR in Exp. II was significantly higher than for the remaining conditions. Based on these findings, high level of the resistance for delta ESR was discussed by attributing it to the internalization of ESR.

The conditioned place preference is affected by two independent reinforcement processes

The conditioned place preference method for measuring the affective properties of reinforcing events was studied using treatments of known affective value. The size of the place aversion observed increased with dose when the reinforcer was injections of lithium chloride. The size of the place preference observed increased with concentration when the reinforcer was drinking sucrose solutions. However, when the reinforcer was solutions of saccharin (that were consumed in the same amounts as the sucrose solutions) no place preferences were observed. This finding was explained in terms of the dual reinforcement hypothesis [20] which postulates that although sucrose and saccharin both have positive affective properties (based on their tastes) only sucrose has memory improving properties (based on its post-ingestive action). It was therefore proposed that conditioned place preferences depend on the activation of both affective and memory improving processes. This hypothesis was confirmed by the observation of place preferences with a saccharin solution as the reinforcer when the pairing trials were followed by non-contingent, post-pairing injections of glucose or amphetamine (both of which are known to improve memory). Therefore, behavior in the place preference method depends upon both the affective and the memory improving properties of the reinforcers under test.