Investigation of electrochromic properties of poly(3,5-bis(4-methoxyphenyl)dithieno[3,2-b;2′,3′-d]thiophene)

Electropolymerization of 3,5-bis(4-methoxyphenyl)dithieno[3,2-b;2′,3′-d]thiophene BMPhDTT, having strong electron-donating methoxy groups, was performed, utilizing potentiodynamic method. The homopolymer was characterized by cyclic voltammetry (CV), Fourier transform infrared (FTIR) and UV–vis spectroscopy. Spectroelectrochemical and electrochromic properties of the homopolymer film were investigated and a PBMPhDTT/PEDOT device was constructed to understand its characteristics in detail. It was revealed that the potential range of 0.0–2.0 V is suitable for operating the device between yellow and blue colors. It indicated a good open circuit memory and stability.     

Collaborative and Cognitive Network Platforms: Vision and Research Challenges

In this paper, we present a visionary concept referred to as Collaborative and Cognitive Network Platforms (CCNPs) as a future-proof solution for creating a dependable, self-organizing and self-managing communication substrate for effective ICT solutions to societal problems. CCNP creates a cooperative communication platform to support critical services across a range of business sectors. CCNP is based on the personal network (PN) technology which is an inherently cooperative environment prototyped in the Dutch Freeband PNP2008 and the European Union IST MAGNET projects. In CCNP, the cognitive control plane strives to exploit the resources to better satisfy the requirements of networked applications. CCNP facilitates collaboration inherently. Through cognition in the cognitive control plane, CCNP becomes a self-managed substrate. The self-managed substrate, in this paper, is defined as cognitive and collaborative middleware on which future applications run without user intervention. Endemic sensor networks may be incorporated into the CCNP concept to feed its cognitive control plane. In this paper, we present the CCNP concept and discuss the research challenges related to collaboration and cognition.     

The production of β-SiAlON ceramics with low amounts of additive,at low sintering temperature

In the present work nano-sized powder of β-SiAlON was produced using a wet milling process. Different milling times and mediums (methyl ethyl keton, ethanol and toluene as solvents, polyethyleneglicol, oleic acid, sodium tripolyphosphate and polyvinylpyrrolidon as dispersants) were performed for the determination of the most efficient milling system. The powders were produced using a conventional process (the ball to powder ratio was 1:1.5, at 300 rpm, for 1.5 h) having a few hundred nanometer particle size, and these were used as standard powders in this study. The nano-sized β-SiAlON starting powders (<100 nm) were sintered at lower temperatures than that of the conventional powders. The amount of Y₂O₃ in powders (～130 nm), produced by high energy milling process, was fewer than conventional powders (5 wt.%). The results of the powder size, sintering behavior and mechanical properties of this sample were compared to those of the standard powder and its sintered sample. This sample, produced using the nano-powder, was investigated, and densified at 150 °C lower than that of the standard sample. Even though the amount of Y₂O₃ was decreased, the hardness of the samples was better than that of the standard sample.     

Optimization of Multireservoir Systems by Genetic Algorithm

Application of optimization techniques for determining the optimal operating policy of reservoirs is a major issue in water resources planning and management. As an optimization Genetic Algorithm, ruled by evolution techniques, have become popular in diversified fields of science. The main aim of this study is to explore the efficiency and effectiveness of genetic algorithm in optimization of multi-reservoirs. A computer code has been constructed for this purpose and verified by means of a reference problem with a known global optimum. Three reservoirs in the Colorado River Storage Project were optimized for maximization of energy production. Besides, a real-time approach utilizing a blend of online and a posteriori data was proposed. The results obtained were compared to the real operational data and genetic algorithm was found to be effective and can be utilized as an alternative technique to other traditional optimization techniques.     

The influence of different circular hole perforations on interlaminar shear strength of a novel fiber metal laminates

This study characterizes surface treated classic type fiber metal laminates (FMLs) interlaminar shear strength (ILSS) based on a glass mat reinforced polyphenylene sulphide composite and an aluminum alloy. The effect of concentration of γ‐glycidoxypropyltrimethoxysilane surface treatment on ILSS of adhesive bonding between aluminum sheet and composite laminates has been investigated. After determining the silane concentration, novel FML material is manufactured using a compression moulding process which involves aluminum sheets with different circular hole perforations (Array type A and B) with two circular hole diameters (ϕ3 and ϕ5 mm) and two total hole area/closed area: 0.05 and 0.06) to develop mechanical interlocking between aluminum layers and composite laminates. Tensile tests are performed to investigate the effect of different circular hole perforations on ILSS properties of FMLs. Test results show that ILSS is improved with increasing the circular hole diameter and decreased with the number of holes as correlated with undrilled FMLs. Failure modes, damage initiation, and progression of FMLs with different open hole perforations are determined with optical microscope. POLYM. COMPOS., 37:963–973, 2016. © 2014 Society of Plastics Engineers     

Cooperative Communications in Future Home Networks

The basic idea behind cooperative communications is that mobile terminals collaborate to send data to each other. This effectively adds diversity in the system and improves the overall performance. In this paper, we investigate the potential gains of cooperative communication in future home networks. We derive analytical expressions for the error probability of binary phase shift keying (BPSK) signals over Nakagami-m fading channels in a multi relay communication network. Following to the analytical study, we analyze the contribution of cooperative relaying to the 60GHz network connectivity through simulations using a realistic indoor environment model. We compare the performance of different relay configurations under variable obstacle densities. We show that a typical 60GHz indoor network should employ either a multi-relay configuration or a single-relay configuration with a smart relay selection mechanism to achieve acceptable outage rates. In the use of multiple-relay configuration, both analytical and simulation studies indicate that increasing the number of cooperative relays does not improve the system performance significantly after a certain threshold.