New Inorganic–Organic Hybrid Materials and Their Oxides for Removal of Heavy Metal Ions: Response Surface Methodology Approach

In this paper, Cu(II), Fe(III), Pb(II), and Zn(II) heavy metal ions were removed from their aqueous solutions by using novel inorganic–organic hybrid materials, Al-GPTS-H and Al-GPTS-NaOSiMe₃-H (hybrid material-1 and 2, respectively), and their oxides (calcined-1 and 2) as adsorbents. These ions removal by adsorption was optimized by using response surface methodology (RSM). Central composite design (CCD) method was used in order to investigate the effects of initial pH, initial metal concentration of solutions and adsorbent quantity on the adsorption efficiency (R, %). As a result of the experiments under optimum conditions, the maximum % R values were obtained by hybrid material-1 for Fe(III) (99.89%) and by calcined material-1 for Pb(II) (97.14%), respectively. These quite high adsorption efficiency values have shown that these hybrid materials and their oxides are suitable to use for heavy metal ions removal from aqueous solutions.     

Lane detection and tracking using a new lane model and distance transform

Lane detection is a significant component of driver assistance systems. Highway-based lane departure warning solutions are in the market since the mid-1990s. However, improving and generalizing vision-based lane detection remains to be a challenging task until recently. Among various lane detection methods developed, strong lane models, based on the global assumption of lane shape, have shown robustness in detection results, but are lack of flexibility to various shapes of lane. On the contrary, weak lane models will be adaptable to different shapes, as well as to maintain robustness. Using a typical weak lane model, particle filtering of lane boundary points has been proved to be a robust way to localize lanes. Positions of boundary points are directly used as the tracked states in the current research. This paper introduces a new weak lane model with this particle filter-based approach. This new model parameterizes the relationship between points of left and right lane boundaries, and can be used to detect all types of lanes. Furthermore, a modified version of an Euclidean distance transform is applied on an edge map to provide information for boundary point detection. In comparison to an edge map, properties of this distance transform support improved lane detection, including a novel initialization and tracking method. This paper fully explains how the application of this distance transform greatly facilitates lane detection and tracking. Two lane tracking methods are also discussed while focusing on efficiency and robustness, respectively. Finally, the paper reports about experiments on lane detection and tracking, and comparisons with other methods.     

Generalised residual images’ effect on illumination artifact removal for correspondence algorithms

The intensity (grey value) consistency of image pixels in a sequence or stereo camera setup is of central importance to numerous computer vision applications. Most stereo matching and optical flow algorithms minimise an energy function composed of a data term and a regularity or smoothing term. To date, well performing methods rely on the intensity consistency of the image pixel values to model the data term. Such a simple model fails if the illumination is (even slightly) different between the input images. Amongst other situations, this may happen due to background illumination change over the sequence, different reflectivity of a surface, vignetting, or shading effects.In this paper, we investigate the removal of illumination artifacts and show that generalised residual images substantially improve the accuracy of correspondence algorithms. In particular, we motivate the concept of residual images and show two evaluation approaches using either ground truth correspondence fields (for stereo matching and optical flow algorithms) or errors based on a predicted view (for stereo matching algorithms).     

Thermal and mechanical properties of polypropylene nanocomposite materials reinforced with cellulose nano whiskers

We use polypropylene (PP, an apolar polymer) and cellulose nano whiskers (CNW, a polar material) to produce nano polymer composites with enhanced mechanical and thermal properties. To improve compatibility, maleic anhydride grafted PP has also been used as a coupling agent. To enhance the uniform distribution of CNW in the composite, the matrix polymer is dissolved in toluene, and sonification and magnetic stirring are applied. Good film transparency indicates uniform CNW dispersion, but CNW domains in the composite film observed under an scanning electron microscope may indicate slight agglomeration of CNW in the composite film. The tensile strength of the composite compared with neat PP improves by 70–80% with the addition of CNW. The crystallinity has also been improved by about 50% in the CNW reinforced samples. As the content of CNW increases, the composite exhibits higher thermal degradation temperature, higher hydrophilicity, and higher thermal conductivity. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of thiophene functionalized polystyrene copolymers and their electrochemical properties

Thiophene functionalized polystyrene samples (TFPS) were synthesized by atom transfer radical polymerization (ATRP) of styrene, followed by Suzuki coupling with 3‐thiophene (Th) boronic acid. Conducting graft polymer of TFPS with thiophene was achieved at 1.5 V in tetrabutylammonium tetrafluoroborate/dichloromethane (TBAFB/DM) by electrochemical methods. Spectroelectrochemical analysis of the resulting copolymers [P(TFPS‐co‐Th)] reflected electronic transitions at 449, 721 and 880 nm, revealing π ? π* transition, polaron and bipolaron band formation, respectively. We also successfully established the utilization of dual type complementary colored polymer electrochromic devices using P(TFPS‐co‐Th)/poly(3,4‐ethylenedioxythiophene (PEDOT) in sandwich configuration. The switching ability, stability and optical memory of the electrochromic device were investigated by UV–visible spectrophotometry and cyclic voltammetry. Device switches between brown and blue color with a switching time of 1.3 s were prepared with optical contrast (%ΔT) of 25 %. Copyright © 2005 Society of Chemical Industry     

A hybrid method of turbulent flow modelling in packings of complex geometry

In this work, experimental investigations and computational simulations were combined into a hybrid method of complex phenomena modelling. In particular, the thermo-anemometric technique and the multi-scale methodology of modelling were applied to investigate air turbulent flow within a rectangular container filled with spheres in cubic arrangement and different baffles alternatively inserted between the spheres. The model systems formed the complex geometric structures where three length scales were distinguished. Hence, the local fluctuations of air velocity were examined in the micro-scale determined by the size of the anemometric probe. The interstitial flow distributions, in turn, were investigated in the cell scale related to the sphere diameter. At last, the pressure drop changes caused by the superficial flow distributions were analysed in the apparatus scale. In each case, the particular experimental data were approximated by numerical modelling. However, when the information exchange between the complementary models was arranged, the significance of the flow mechanisms dominating in particular length scales could be confirmed in relation to all the experimental data determined in this work. In recapitulation, it was indicated how experimental and numerical investigations can be effectively combined in searching for a “profitable” anisotropy of the packing resistance to flow.