Influence of polymerization conditions on the template free synthesis of nanoparticles of poly (1-naphthylamine)

The present article highlights some preliminary investigations on the role of oxidant and medium on the nanostructured morphology of poly (1-naphthylamine) (PNA) prepared via chemical oxidative polymerization. Results revealed that the nano morphology can be controlled under appropriate preparative conditions. The particle sizes were obtained in the range of 5–50 nm exhibiting a much smaller range than polyaniline (PANI) nanoparticles synthesized under similar conditions.     

Microscopic image analysis for quantitative measurement and featureidentification of normal and cancerous colonic mucosa

The development of an automated algorithm for the categorization of normal and cancerous colon mucosa is reported. Six features based on texture analysis were studied. They were derived using the co-occurrence matrix and were angular second moment, entropy, contrast, inverse difference moment, dissimilarity, and correlation. Optical density was also studied. Forty-four normal images and 58 cancerous images from sections of the colon were analyzed. These two groups were split equally into two subgroups: one set was used for supervised training and the other to test the classification algorithm. A stepwise selection procedure showed that correlation and entropy were the features that discriminated most strongly between normal and cancerous tissue (P<0.0001). A parametric linear-discriminate function was used to determine the classification rule. For the training set, a sensitivity and specificity of 93.1% and 81.8%, respectively, were achieved, with an overall accuracy of 88.2%. These results mere confirmed with the test set, with a sensitivity and specificity of 93.1% and 86.4%, respectively, and an overall accuracy of 90.2%     

APPARATUS FOR THE MEASUREMENT OF DECOMPRESSION WAVE FRONT VELOCITY BASED SOUND SPEEDS AND OF ASSOCIATED DENSITIES AND ISOTHERMAL COMPRESSIBILITY COEFFICIENTS IN MODERATELY DENSE GASES

An apparatus containing a T-shaped tube fitted with a rupture diaphragm was developed in order to generate simultaneously two decompression waves traveling in opposite directions through a gas. The speeds of decompression wave fronts observed at ideal gas densities were found to be precisely equal to the calculated values of the speed of sound of equilibrium thermodynamics. Accordingly, the observed speed of the wave front is adopted as the speed of sound at all gas densities. Wave front speeds are determined from transit-times between two piezoelectric transducers mounted face-on to the waves and average speed of the two wave fronts is recorded at the speed of sound at a chosen pressure and temperature. The gas density is determined by discharging the contents of a small side-chamber filled with the gas at this state into a pre-evacuated chamber sufficiently large that the mass of discharged gas is provided with precision by the ideal gas law. The compressibility coefficient is measured at slightly higher pressures and is determined from the isothermal decrease in pressure resulting from a controlled leak of the gas in the T-tube to the small side-chamber. All gas-containing vessels were maintained at constant temperature to within ±0,1°C by immersion in a suitable bath.     

Novel computational methods for high‐dimensional stochastic sensitivity analysis

This paper presents three new computational methods for calculating design sensitivities of statistical moments and reliability of high‐dimensional complex systems subject to random input. The first method represents a novel integration of the polynomial dimensional decomposition (PDD) of a multivariate stochastic response function and score functions. Applied to the statistical moments, the method provides mean‐square convergent analytical expressions of design sensitivities of the first two moments of a stochastic response. The second and third methods, relevant to probability distribution or reliability analysis, exploit two distinct combinations built on PDD: the PDD‐saddlepoint approximation (SPA) or PDD‐SPA method, entailing SPA and score functions; and the PDD‐Monte Carlo simulation (MCS) or PDD‐MCS method, utilizing the embedded MCS of the PDD approximation and score functions. For all three methods developed, the statistical moments or failure probabilities and their design sensitivities are both determined concurrently from a single stochastic analysis or simulation. Numerical examples, including a 100‐dimensional mathematical problem, indicate that the new methods developed provide not only theoretically convergent or accurate design sensitivities, but also computationally efficient solutions. A practical example involving robust design optimization of a three‐hole bracket illustrates the usefulness of the proposed methods. Copyright © 2014 John Wiley & Sons, Ltd.     

An efficient memetic algorithm for 3D shape matching problems

Shape representation plays a vital role in any shape optimization exercise. The ability to identify a shape with good functional properties is dependent on the underlying shape representation scheme, the morphing mechanism and the efficiency of the optimization algorithm. This article presents a novel and efficient methodology for morphing 3D shapes via smart repair of control points. The repaired sequence of control points are subsequently used to define the 3D object using a B-spline surface representation. The control points are evolved within the framework of a memetic algorithm for greater efficiency. While the authors have already proposed an approach for 2D shape matching, this article extends it further to deal with 3D shape matching problems. Three 3D examples and a real customized 3D earplug design have been used as examples to illustrate the performance of the proposed approach and the effectiveness of the repair scheme. Complete details of the problems are presented for future work in this direction.     

Reducing the greenhouse gas footprint of primary metal production: Where should the focus be?

The mineral processing and metal production sector is endeavouring to identify opportunities to improve the sustainability of its operations and reduce its greenhouse gas footprint, with improved energy efficiency receiving increased attention. However, if truly sustainable outcomes are to be obtained it is essential that a life cycle approach be adopted in evaluating these opportunities. In this paper, life cycle assessment methodology is used to indicate where in the metal production life cycle this focus on energy efficiency should be and to evaluate a number of potential opportunities for reducing the greenhouse gas footprint of primary metal production.Results from life cycle assessments of the main primary metal production processes, together with current and predicted global metal production rates, ore grades and grind or liberation size, have been used in a broad analysis to indicate that endeavours to improve the energy efficiency of primary metal production should focus mainly on the metal extraction stage, particularly for steel and aluminium. Declining ore grades and more complex ore bodies anticipated in the future can be expected to significantly increase the energy required for comminution of the main metal ores and will present opportunities for improving the energy efficiency of primary metal production. However, these opportunities will still be appreciably less than potential energy efficiency improvements in the extraction stage for these metals.     

In-vitro antioxidant and antibacterial activities of pumpkin,quince, muskmelon and bottle gourd seeds

Ethanol and chloroform extracts of pumpkin, quince, muskmelon, and bottle gourd seeds were studied for in-vitro antioxidant and antibacterial activities. Crude protein and fat contents of all the seeds compared favorably with high protein legumes and high oil containing oilseeds. Ethanol and chloroform extracts of bottle gourd seeds had highest phenolic content. A direct positive relationship between antioxidant activities and extract concentration was observed with the relationship being more pronounced in chloroform extract of quince seeds (R²?=?0.9685 and 0.9829) followed by ethanol extract of pumpkin seeds (R²?=?0.9666 and 0.9685) as per 1,1-diphenyl-2-picrylhydrazyl and hydrogen peroxide (H₂O₂) method, respectively. Seed extracts were also studied for in-vitro antibacterial activity against Salmonella typhii, Enterococcus sp., Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Ethanol extract of pumpkin seeds inhibited the growth of all bacteria; however, both the extracts of quince seeds did not show any activity against S. typhii, E. coli and S. aureus.