Green and friendly media transmission algorithms for wireless body sensor networks

Multimedia Tools and Applications - Video transmission is considered as a quite significant step towards health monitoring of the emergency patients during any critical incident. However, the...     

Identification of pyrazine derivatives in a typical maple syrup using headspace solid-phase microextraction with gas chromatography–mass spectrometry

Headspace solid-phase microextraction combined with gas chromatography–mass spectrometry was applied to identify pyrazines in a typical maple syrup characterised by plant ligneous or sawdust flavour. Carboxen/polydimethylsiloxane (85 μm) fibre and Supelcowax 10 column were selected instead of Carbowax/divinylbenzene (65 μm) fibre and VF-5ms column, respectively, because of their high capacity to extract and separate pyrazines. A total of 27 pyrazines were identified. To our knowledge, about half of these compounds had not previously been detected in maple syrup and 15 pyrazines were flavour components.     

Anhydride production as an additional mechanism of poly(3‐hydroxybutyrate) pyrolysis

Anhydrides production is newly proposed as an additional pyrolysis mechanism of a biopolymer, poly(3‐hydroxybutyrate) (PHB). In spite of many suggestions of multiple degradation mechanisms, simple random chain scission by β‐elimination has been accepted as an exclusive mechanism of the thermal degradation of PHB. However, a wide range of activation energy value of the degradation and the deviation from the random chain scission statistics have suggested the presence of other kinds of mechanism out of the random scission. To confirm other mechanisms out of the random scission, minor pyrolyzates from PHB were characterized with ¹H/¹³C‐NMR, Fourier transform infrared spectroscopy, and fast atom bombardment mass spectrometry. As a result, crotonic anhydride and its oligomers were detected as minor products from condensation reactions between carboxyl groups. The anhydrides production must be one reaction out of the conforming process to the random degradation statistics and contribute to the complexity of PHB pyrolysis. An expected thermal degradation pathway of PHB was proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

A PSO-ANFIS framework for prediction of density of bitumen diluted with solvents

One of the important properties in petroleum engineering calculations in heavy oil reservoirs is the density of bitumen diluted with solvents. It is required in newly developed solvent based enhanced oil recovery methods. Hence, developing accurate models for prediction of this parameter is essential. To tackle this issue, this study presents an accurate model based on adaptive neuro-fuzzy inference system trained by particle swarm optimization (PSO-ANFIS) for estimation of density of bitumen diluted with solvents and hydrocarbon mixtures using experimental data from literature. The accuracy and reliability of results were evaluated by utilizing various statistical and graphical approaches and comparing the predictions of the developed model with literature models. The analysis showed that the PSO-ANFIS model is capable to predict the experimental data with acceptable error and high accuracy. The predictions of the PSO-ANFIS model were also better than the literature models.     

Poly(vinylidene fluoride)‐Based Membranes for Microalgae Filtration

Two poly(vinylidene fluoride) (PVDF) membrane modification approaches, i.e., poly(vinylpyrrolidone) (PVP) modification and sulfonation, were applied and investigated to produce a fouling‐resistant membrane for microalgae filtration. Both methods were able to alter the membrane surface to become more hydrophilic. However, clean water permeance increased only for the PVP‐modified membranes, while the sulfonated membranes underwent a significant morphology transformation to a denser membrane and thus lower permeance. Microalgae filtration with PVP‐modified membranes showed less fouling compared to the pristine one, particularly in the beginning of the filtration, indicating that fouling reduction on these membranes mainly occurs in the initial fouling stage. Fouling is also found to be influenced by the microalgae species, possibly due to the different properties of the formed cake layer.     

Scene text detection using enhanced Extremal region and convolutional neural network

Multimedia Tools and Applications - Text in scene images usually contains significant information. Text detection and recognition in the scene is important for a variety of advanced machine vision...     

Sample-specific late classifier fusion for speaker verification

Multimedia Tools and Applications - Due to the mismatch between training and test conditions, speaker verification in real environments, continues to be a challenging problem. An effective way of...     

“Dialdehyde Cellulose” Nanofibers by Electrospinning as Polyvinyl Alcohol Blends: Manufacture and Product Characterization

A nanofiber was obtained by electrospinning of “dialdehyde cellulose” (periodate-oxidized cellulose, DAC) and polyvinyl alcohol (PVA), using only water as the solvent. Celluloses of four different origins were fully oxidized with sodium periodate to water-soluble DAC. Aqueous solution of DAC showed inadequate spinnability regardless of the polymer concentration and the electrospinning conditions used. Addition of PVA improved the solution's viscoelasticity and, consequently, the solution's spinnability. We examined the effects of DAC/PVA composition and electrospinning parameters on fiber morphology. Highly homogeneous nanofibers were prepared from 1:1 up to 2:1 (weight) DAC/PVA blends while samples of lower viscosity or higher relative DAC contents resulted in continuous, beaded fiber networks. Characterization of the electrospun fabrics revealed a highly crosslinked DAC structure reinforced with PVA, strongly interacting through hemiacetal bonds and hydrogen bonding. Fluorescence labeling confirmed the presence of reactive aldehyde functionalities in the electrospun web. The versatile properties of DAC as reactive material can now be imparted on electrospun fiber and nanofiber material – which was not possible so far –further widening the application scope of this interesting cellulose derivative.     

Preparation and characterisation of aluminium zirconium oxide for metal-oxide-semiconductor capacitor

A functional type metal-oxide-semiconductor (MOS) based capacitor was fabricated and studied by using aluminium zirconium oxide (Al_xZr_yO_z) as a potential high dielectric constant (k) gate oxide, which was transformed from as-sputtered Al-Zr alloy after undergoing a wet oxidation at 400°C, 600°C, 800°C, and 1000°C in the presence of nitrogen as a carrier gas. A mixture of tetragonal ZrO₂-monoclinic Al_xZr_yO_z phases were present at 600°C while stablized tetragonal Al_xZr_yO_z phases were detected at higher temperatures with a minute micro strain change. The largest k value (21) was obtained by the film oxidised at 600°C, followed by 800°C while the lowest one at 1000°C. The discrepancy was due to the absence of tetragonal ZrO₂ in the latter films. The attainment of a k value closer to the reported value for ZrO₂ at 600°C suggested that the tetragonal ZrO₂ phase was one of the factors yielding a high k value at 600°C. However, further investigation was required for this sample because the slow trap density and total interface trap density was high despite a high k value, mainly attributed to the presence of negatively charged traps as the scattering centre in the film. The film obtained at 1000°C was not encourageable to be deployed as a passivation layer for Si MOS device due to its low k controlled by the thick interfacial layer.     

Effect of sulfur addition and nanocrystallization on the transport properties of lithium–vanadium–phosphate glasses

The glasses defined by the formula 37.5Li₂O–25V₂O₅–37.5P₂O₅ mol% containing different sulfur (0, 10, 50 and 100 mol%) content were studied before and after nanocrystallization. X-ray diffraction and transmission electron micrograph of the heat treated samples indicated nanocrystals embedded in the glass matrix. The average crystallite size was found between 18 and 37 nm. Sulfur (S) behaved as a reducing agent for redox reaction during preparation of glass and affected the conductivity, i.e., the V⁴⁺–V⁵⁺ or V³⁺–V⁴⁺ion pairs increased with increasing S content and led to increasing conductivity of glasses. After creation of the nanocrystalline phase, S-free glass–ceramic nanocomposite exhibited improvement in electrical conductivity around three orders of magnitude than initial glass. This great improvement of electrical conductivity is related to increase in a concentration of V⁴⁺–V⁵⁺or V³⁺–V⁴⁺ ion pairs and also, forming of defective and well-conducting regions along the crystallite/glass interfaces. The decrease in electrical conductivity in the 50S glass–ceramic nanocomposite, which possessed the highest crystallite size, could be related to the increase of grain boundaries scattering because of the increasing crystallite size. The conduction was attributed to non-adiabatic small polaron hopping and mostly determined by hopping carrier mobility.