Optimal matching by the transiently chaotic neural network

Dynamic programming matching (DPM) is a technique that finds an optimal match between two sequences of feature vectors allowing for stretched and compressed sections of the sequence. The purpose of this study is to formulate the matching problem as an optimization task and carry out this optimization problem by means of a chaotic neural network. The proposed method uses TCNN, a Hopfield neural network with decaying self-feedback, to find the best-matching (i.e., the lowest global distance) path between an input and a template. Experimental results show a very good performance for the proposed algorithm in pattern recognition tasks.     

Two-Photon Polymerized Shape Memory Microfibers: A New Mechanical Characterization Method in Liquid

Two-photon polymerization (TPP) is widely used to create 3D micro- and nanoscale scaffolds for biological and mechanobiological studies, which often require the mechanical characterization of the TPP fabricated structures. To satisfy physiological requirements, most of the mechanical characterizations need to be conducted in liquid. However, previous characterizations of TPP fabricated structures are all conducted in air due to the limitation of conventional micro- and nanoscale mechanical testing methods. In this study, a new experimental method is reported for testing the mechanical properties of TPP-printed microfibers in liquid. The experiments show that the mechanical behaviors of the microfibers tested in liquid are significantly different from those tested in air. By controlling the TPP writing parameters, the mechanical properties of the microfibers can be tailored over a wide range to meet a variety of mechanobiology applications. In addition, it is found that, in water, the plasticly deformed microfibers can return to their predeformed shape after tensile strain is released. The shape recovery time is dependent on the size of microfibers. The experimental method represents a significant advancement in mechanical testing of TPP fabricated structures and may help release the full potential of TPP fabricated 3D tissue scaffolds for mechanobiological studies.     

Pervaporation study of ethylene glycol dehydration through synthesized (PVA–4A)/polypropylene mixed matrix composite membranes

Poly(vinyl alcohol) (PVA)/zeolite 4A mixed matrix composite membranes supported on polypropylene microfiltration membranes were prepared by solution casting method and crosslinked with glutaraldehyde to investigate their pervaporation (PV) separation properties of water–ethylene glycol mixtures. Scanning electron microscopy images showed homogeneous distribution of zeolite nanoparticles within the polymer matrix without any visible macroscopic voids at the zeolite–polymer interface. The PV experiments were accomplished to investigate the effects of water concentration (10–40 wt%) and temperature (60–80°C) on separation performance of the membranes. It was found out that 5 wt% loading of the 4A nanoparticles into the PVA matrix is optimal to obtain the best separation performance. The experimental results revealed that loading of zeolite 4A enhanced the membrane performance [both permeation flux (5%) and separation factor (32%) at 5 wt% zeolite loading]. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Screening alternatives for producing paraffinic phase change materials for thermal energy storage in buildings

Screening alternatives for producing paraffinic phase change materials (PCMs) from natural gas‐based products was investigated. Based on the quality and cost of these PCMs, two sources were identified: (i) hydrogenated gas‐to‐liquid (GTL) products such as heavy detergent feedstocks; and (ii) linear alpha olefins. Fractionation of a typical hydrogenated GTL mixture, containing C₁₄ – C₁₈ alkene and alkane hydrocarbons, has been experimentally conducted to produce five paraffinic PCMs with melting points between 3 and 28 °C. ChemCAD simulation has been proved to be a valid tool for predicting the behaviour of the GTL fractionation, including optimum experimental conditions and compositions of products. Also, hydrogenation of technical 1‐octadecene was experimentally carried out in order to evaluate the quality of PCM produced from one of the available technical alpha‐olefins. All PCMs produced in this work were analysed by gas chromatography equipped with flame ionization detector to determine their compositions and by differential scanning calorimetry to determine their latent heats. The results showed that the PCM with a melting temperature in the range 22 to 25 °C can be technically produced through hydrogenation of commercial 1‐octadecene showing a higher latent heat compared to the PCM produced from fractionation of hydrogenated GTL mixture. Copyright © 2017 John Wiley & Sons, Ltd.     

A Demand-Based Structure for the Architecture of Wireless Networks on Chip

Wireless Personal Communications - Wireless networks on chip (WiNoC) are considered to be a novel approach for designing efficient and scalable systems. The rationale behind this new approach is to...     

A tiny EBG‐based structure multiband MIMO antenna with high isolation for LTE/WLAN and C/X bands applications

This article proposes a compact multiple‐input multiple‐output (MIMO) antenna with the electromagnetic band gap (EBG) structures for mobile terminals. The proposed MIMO antenna is composed of two radiation patches in which diagonal and folded microstrip lines are utilized to control the frequency bands. The radiation patch, one EBG structure and a rectangular‐shaped ground plane are etched on both sides of the antenna. The EBG structures have been employed for reducing the mutual coupling between the antenna elements. As a result of the effect of these structures, the mutual coupling between the two elements is reduced by less than ?30 dB. The proposed antenna is implemented on an FR4 substrate with dimensions 20 × 10 × 1 mm³. According to measured results, frequency ranges of 2.2 to 3.6 GHz and 5.1 to 5.9 GHz with S₁₁ < ?10 dB and also 3.7 to 5 GHz and 8 to 12 GHz with S₂₂ < ?10 dB have been obtained. Moreover, measured S₁₂ and S₂₁ with values of less than ?30 dB for both Ports have been realized. Additionally, the envelope correlation and radiation efficiency of the purposed antenna are less than 0.09 and more than 82%, respectively.