Fabrication of polysulfone nanocomposite membranes with silver‐doped carbon nanotubes and their antifouling performance

In this study, polysulfone (PSf)/silver‐doped carbon nanotube (Ag‐CNT) nanocomposite membranes were prepared by a phase‐inversion technique; they were characterized and evaluated for fouling‐resistant applications with bovine serum albumin (BSA) solutions. Carbon nanotubes were doped with silver nanoparticles via a wet‐impregnation technique. The prepared Ag‐CNT nanotubes were characterized with scanning electron microscopy (SEM)/energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, Raman spectroscopy, and thermogravimetric analysis. The fabricated flat‐sheet PSf/Ag‐CNT nanocomposite membranes with different Ag‐CNT loadings were examined for their surface morphology, roughness, hydrophilicity, and mechanical strength with SEM, atomic force microscopy, contact angle measurement, and tensile testing, respectively. The prepared composite membranes displayed a greater rejection of BSA solution (≥90%) and water flux stability during membrane compaction with a 10% reduction in water flux values (up to 0.4% Ag‐CNTs) than the pristine PSf membrane. The PSf nanocomposite membrane with a 0.2% Ag‐CNT loading possessed the highest flux recovery of about 80% and the lowest total membrane resistance of 56% with a reduced irreversible fouling resistance of 21%. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44688.     

Application of a radial basis function artificial neural network to seismic data inversion

We investigate here the performance and the application of a radial basis function artificial neural network (RBF-ANN) type, in the inversion of seismic data. The proposed structure has the advantage of being easily trained by means of a back-propagation algorithm without getting stuck in local minima. The effects of network architectures, i.e. the number of neurons in the hidden layer, the rate of convergence and prediction accuracy of ANN models are examined. The optimum network parameters and performance were decided as a function of testing error convergence with respect to the network training error. An adequate cross-validation test is run to ensure the performance of the network on new data sets. The application of such a network to synthetic and real data shows that the inverted acoustic impedance section was efficient.     

Influence of recycled sand and gravel on the rheological and mechanical characteristic of concrete

The objective of this paper is to investigate the influence of type and dosage of recycled sand (RS) and gravel on the fresh and mechanical properties of concrete. Experimental program was conducted on concretes made with different ratio of substitutions (15, 30, 70, and 100%) of natural sand and gravel with RS and gravel. At the fresh state, slump, air content, and density were measured at the exit of the mixer, and then at 30, 60, and 90 min after mixing. Tests were also performed for compressive strength at the age of 1, 7, and 28 days, whereas elastic modulus measurements were done at 28 days. The results indicated that maintaining the workability of recycled aggregate concrete depends on sand or gravel substitution and their rates. Up to 30 min, slump values were decreased, but after that, no substantial change in slump values was observed. Air content increased and density decreased, with increasing recycled aggregate content (sand or gravel). Mechanical properties, such as compressive strength and modulus of elasticity, were lower than those of reference concrete.     

An improved multimodal signal-image compression scheme with application to natural images and biomedical data

Multimedia Tools and Applications - In this paper, a new multimodal compression scheme is proposed with the aim of compressing jointly an image and a signal via a single codec. The key idea behind...     

Veratric acid treatment by anodic oxidation with BDD anode

BACKGROUND: Veratric acid (VA, 3,4‐dimethoxy‐benzoic acid) is representative of the polyphenolic type compounds present in olive mill wastewater (OMW). Given the bactericide factor, the inhibitor character and the anti bacteriological activity of this compound, traditional biological digestion cannot be applied and therefore new technologies, such as electrochemical oxidation using a boron‐doped diamond (BDD) anode have to be considered to avoid its accumulation in the environment. RESULTS: The electrochemical oxidation of aqueous solutions containing 1 mmol L^?1 VA has been investigated using a filter‐press reactor with a BDD anode during galvanostatic electrolysis. The influence of several operating parameters, such as applied current density, temperature, flow‐rate and supporting electrolyte concentration and type has been investigated. The experimental results showed that under the experimental conditions used the oxidation of VA was under mass‐transfer control and VA was completely degraded by the reaction with hydroxyl radicals electrogenerated at the BDD surface. The chemical oxygen demand (COD) decay kinetic followed a pseudo‐first‐order reaction and the apparent rate constant increased with flow rate and temperature. Under optimal experimental conditions of flow‐rate (300 L h^?1), temperature (35 °C) and current density (10 mA cm^?2), 99.5% of COD was removed during 2 h electrolysis, with 16.4 kWh m^?3 energy consumption. CONCLUSIONS: This study suggests that anodic oxidation with a BDD electrode is an excellent method for the treatment of effluents contaminated with VA and related polyphenols. Copyright © 2011 Society of Chemical Industry     

Effect of Processing Parameters on Physical Properties of Cadmium Stannate Thin Films Prepared by a Dip-Coating Technique

Thin films of dicadmium stannate spinel (Cd₂SnO₄) were deposited on glass substrates using a dip-coating technique. The films were transparent to visible light (90%) and electrically conductive. X-ray diffractometry showed that annealed films consisted of a single cubic spinel phase only when they were prepared from a solution with the composition of Cd:Sn = 2.5 and fired at a temperature of 400°–500°C. The Cd:Sn ratio, the firing temperature, and the post-deposition annealing sequence were crucial for the formation of a single phase, which is vital to obtain optimal optical and electrical properties. A resistivity as low as 3.3 × 10⁻⁴Ω·cm could be obtained after annealing.     

Camera calibration using court models for real-time augmenting soccer scenes

In this paper, we present a procedure to estimate the position, orientation and focal length of a camera in a soccer field. These parameters are then used in real-time overlay of graphics on a soccer pitch. The method uses court model composed by arcs and lines. A means of automatically initializing the tracking process is also presented which uses Hough transform with a combination of a non-linear least squares optimization method. For the tracking of camera parameters, two cases arise: the center of the pitch and the 18 m area. A combination of automatic court model recognition with the Kanade-Lucas-Tomasi (KLT) algorithm is also used.     

Performance study of distributed Apriori-like frequent itemsets mining

In this article, we focus on distributed Apriori-based frequent itemsets mining. We present a new distributed approach which takes into account inherent characteristics of this algorithm. We study the distribution aspect of this algorithm and give a comparison of the proposed approach with a classical Apriori-like distributed algorithm, using both analytical and experimental studies. We find that under a wide range of conditions and datasets, the performance of a distributed Apriori-like algorithm is not related to global strategies of pruning since the performance of the local Apriori generation is usually characterized by relatively high success rates of candidate sets frequency at low levels which switch to very low rates at some stage, and often drops to zero. This means that the intermediate communication steps and remote support counts computation and collection in classical distributed schemes are computationally inefficient locally, and then constrains the global performance. Our performance evaluation is done on a large cluster of workstations using the Condor system and its workflow manager DAGMan. The results show that the presented approach greatly enhances the performance and achieves good scalability compared to a typical distributed Apriori founded algorithm.