A parallel algorithm for generating chain code of objects in binary images

This paper addresses parallel execution of chain code generation on a linear array architecture. The contours in the proposed algorithm are viewed as a set of edges (or contour segments) that can be traced by a top-down contour tracing method to generate the chain codes for the outer and inner object contours. A parallel algorithm that contains the chain code generating rules and operations needed is also described, and the algorithm is mapped onto a one-dimensional systolic array containing processing elements (PEs) to devise this architecture. The architecture extracts the contours of objects and quickly generates the corresponding chain codes after the image data in all rows are inputted in a linear fashion. The total processing time for generating the chain codes in an N×N image is O(3N). By doing so, the real-time requirement is fulfilled and its execution time is independent of the image content. In addition, a partition method is developed to process an image when the parallel architecture has a fixed number of PEs; say two or more. The total execution time for an N×N image by employing a fixed number of PEs is N(N+1)/M+2(M−1), when M is the fixed number of PEs.     

Catalytic wet air oxidation of phenol by CeO2 catalyst--effect of reaction conditions

The effect of catalyst loading, oxygen pressure, reaction temperature and phenol concentration on phenol conversion and total organic carbon (TOC) conversion, using CeO(2) as the catalyst, was investigated. There appeared a maximum rate of phenol conversion and TOC conversion as the catalyst loading increased. With phenol concentrations in the range of 400-2500 mg/L and oxygen pressure of 0.5 or 1.0 MPa, the optimal catalyst loading was 1.0 g/L, while it was 2.0 g/L at an oxygen pressure of 1.5 MPa. With a phenol concentration of 5000 mg/L, the optimal loading was 2.0 g/L for all oxygen pressures tested. Catalyst loading influences the reaction via the free-radical chain reaction involved in the catalytic wet air oxidation of phenol. Regarding oxygen pressures, at a phenol concentration of 400mg/L, the influence of the tested pressures (0.5, 1.0 and 1.5 MPa) on the 3h conversion of phenol was negligible, while the effect was significant for higher concentrations of phenol. The effect of oxygen pressure on TOC conversion was more profound, especially at a higher phenol concentration. At a pressure of 0.5 MPa, except for concentration of 400mg/L, the CO(2) selectivity barely exceed 80% at best, and was less than 25% with a phenol concentration of 5000 mg/L. At a pressure of 1.5 MPa, the selectivity was as high as 90% even for a concentration of 5000 mg/L. As was expected, increase of reaction temperature shortened the time taken to reach 50% phenol conversion. In addition, TOC conversion also increased with reaction temperature. Working from these observed results, optimal operating conditions were proposed.     

Improving the quality of fresh‐cut pineapples with ascorbic acid/sucrose pretreatment and modified atmosphere packaging

The effects of pretreatment and modified atmosphere packaging (MAP) on the quality of fresh‐cut pineapples stored at 4°C were evaluated for 7 days. The pretreatment was conducted by immersing the pineapple slices in a solution containing 0.25% ascorbic acid and 10% sucrose for 2min. MAP contained 4% oxygen, 10% carbon dioxide and 86% nitrogen. Both the pretreatment and MAP could reduce the respiration rate, ethylene production, textural and colour deteriorations, as well as the overall sensory deterioration in fresh‐cut pineapples. MAP could restrain the growth of microbes, but the pretreatment showed little effect. Fresh‐cut pineapples exhibited wet surface and off‐flavour after storage at 4°C for 3 days, while the pretreatment and MAP maintained the quality for up to 7 days. Copyright © 2007 John Wiley & Sons, Ltd.     

Decoupling the Direct and Indirect Biological Effects of ZnO Nanoparticles Using a Communicative Dual Cell‐Type Tissue Construct

While matter at the nanoscale can be manipulated, the knowledge of the interactions between these nanoproducts and the biological systems remained relatively laggard. Current nanobiology study is rooted on in vitro study using conventional 2D cell culture model. A typical study employs monolayer cell culture that simplifies the real context of which to measure any nanomaterial effect; unfortunately, this simplification also demonstrated the limitations of 2D cell culture in predicting the actual biological response of some tissues. In fact, some of the characteristics of tissue such as spatial arrangement of cells and cell–cell interaction, which are simplified in 2D cell culture model, play important roles in how cells respond to a stimulus. To more accurately recapitulate the features and microenvironment of tissue for nanotoxicity assessments, an improved organotypic‐like in vitro multicell culture system to mimic the kidney endoepithelial bilayer is introduced. Results showed that important nano‐related parameters such as the diffusion, direct and indirect toxic effects of ZnO nanoparticles can be studied by combining this endoepithelial bilayer tissue model and traditional monolayer culture setting.     

Prediction of fiber orientation distribution in injection molded parts using Moldex3D simulation

In the automotive industry, glass‐filled thermoplastics are used in air intake manifolds, radiator tanks, and many other parts. However, widespread application of glass‐filled thermoplastic materials has been limited in many cases by the inability to accurately predict performance and durability. Since a more accurate fiber orientation prediction will lead to more accurate local mechanical property predictions, this work investigated a recently proposed mathematic model of fiber suspension rheology, which considers the anisotropic fiber diffusion and fiber–matrix interaction from a microscopic viewpoint. The new model proved able to predict many details of the fiber orientation distribution and could be applied advantageously as part of the product and manufacturing development processes. POLYM. COMPOS., 35:671–680, 2014. © 2013 Society of Plastics Engineers     

Efficient Dispersants for TiO2 Nanopowder in Organic Suspensions

This article discusses the appropriate dispersant for titania (TiO₂) nanopowder in organic‐based suspensions. Four types of oleyl‐based dispersants, namely, oleyl alcohol, oleic acid, oleylamine, and oleyl phosphate, which have the functional groups hydroxyl (–OH), carboxyl (–COOH), amino (–NH₂), and phosphorous [–P(=O)(OH)₂], respectively, were compared for their ability to disperse TiO₂. Experimental results for zeta potential, adsorption, FT‐IR spectroscopy, and rheology, as well as theoretical calculations, indicate that dispersants with –P(=O)(OH)₂ and –NH₂ were more efficient than those with –COOH or –OH. The primary reason for this difference is related to the different interactions of TiO₂ with various dispersants and to different dispersion mechanisms. In addition to the major functional groups, –OH in the chemical structure of dispersants was important, as it might have other effects such as destabilization of the suspensions.     

Rattle‐Structured Ag/TiO2 Nanocomposite Capsules with Bactericide and Photocatalysis Activities

A structural design featuring rattle‐type silver/titania (Ag/TiO₂) core/shell, that is, Ag@TiO₂, composite microcapsules is produced. The TiO₂ shell protects the encapsulated, movable Ag nanoparticles from breaking away under moderate loading, minimizing hence adverse environmental and biological exposure due to the metal loss, whereas the mesoporous shell serves as conduits for Ag ions released from the caged Ag nanoparticles to kill Escherichia coli in aqueous solutions under dark condition. The anatase TiO₂ shell imparts an additional, synergistic photocatalysis activity under ultraviolet irradiation. A pronouncedly enhanced photocatalysis activity results when the Ag@TiO₂ composite capsules were thermally annealed under vacuum. This “rattle‐in‐ball” hybrid architecture enables bifunctional bactericide and photocatalysis capability under both light and dark conditions, as well as mitigated environmental and biological impact in practical use.     

A novel two-layer compact electromagnetic bandgap (EBG) structure and its applications in microwave circuits

Recently, photonic bandgap (PBG) structures have become one of the most interesting areas of research. These structures consist of one-, two- or three-dimensional finite periodically perforated dielectric/metallic material or ground planes that forbid the propagation of all electromagnetic waves within a particular frequency band (called the bandgap). This property permits additional control over the behaviour of electromagnetic waves. The research work was originally done in optical region, …     

Structural Basis for the Improved Potency of Peroxisome Proliferator‐Activated Receptor (PPAR) Agonists

The need to develop safer and more effective antidiabetic drugs is essential owing to the growth worldwide of the diabetic population. Targeting the PPAR receptor is one strategy for the treatment of diabetes; the PPAR agonists rosiglitazone and pioglitazone are already on the market. Here we report the identification of a potent PPAR agonist, 15 , whose PPARγ activation was more than 20 times better than that of rosiglitazone. Compound 15 was designed to incorporate an indole head with a carboxylic acid group, and 4‐phenylbenzophenone tail to achieve a PPARγ EC₅₀ of 10 nM . Compound 15 showed the most potent PPARγ agonist activity among the compounds we investigated. To gain molecular insight into the improved potency of 15 , a structural biology study and binding energy calculations were carried out. Superimposition of the X‐ray structures of 15 and agonist 10 revealed that, even though they have the same indole head part, they adopt different conformations. The head part of 15 showed stronger interactions toward PPARγ; this could be due to the presence of the novel tail part 4‐phenylbenzophenone, which could enhance the binding efficiency of 15 to PPARγ.     

A continuous ultrasound‐assisted packed‐bed bioreactor for the lipase‐catalyzed synthesis of caffeic acid phenethyl ester

BACKGROUND: The focus of this paper is the ultrasound‐assisted synthesis of caffeic acid phenethyl ester (CAPE) from caffeic acid and phenyl ethanol in a continuous packed‐bed bioreactor. Immobilized Novozym^® 435 (from Candida antarctica) is used as the catalyst. A three‐level–three‐factor Box–Behnken design and a response surface methodology (RSM) are employed to evaluate the effects of temperature, flow rate, and ultrasonic power on the percentage molar conversion of CAPE. RESULTS: Based on ridge max analysis, it is concluded that the optimum condition for synthesis is reaction temperature 72.66 °C, flow rate 0.046 mL min^?1, and ultrasonic power 1.64 W cm^?2. The expected molar conversion value is 97.84%. An experiment performed under these optimal conditions resulted in a molar conversion of 92.11 ± 0.75%. The enzyme in the bioreactor was found to be stable for at least 6 days. CONCLUSIONS: The lipase‐catalyzed synthesis of CAPE by an ultrasound‐assisted packed‐bed bioreactor uses mild reaction conditions. Enzymatic synthesis of CAPE is suitable for use in the nutraceutical and food production industries. Copyright © 2011 Society of Chemical Industry