Development of a product design and supply-chain fulfillment system for discontinuous innovation

Given the lengthy product development lifecycle process, high cost, and low success rate, many firms avoid considering discontinuous innovation strategies, in spite of their increase in frequency and importance in many markets. Even with advances in automation and technology, many of the techniques being utilised in product development are relatively unchanged, and the definition of discontinuous innovation itself lacks a structural component. To address this problem, the authors developed a methodology for generative customisation to implement discontinuous innovation. Using the emerging technologies of generative design and agent-based modelling, the authors developed a methodology to create product inventions and measure product innovations using a complex adaptive system (CAS) model. This appears to be the first model that represents a complex adaptive system environment to measure the success of discontinuous innovation in the development of a market equilibrium agent model.     

OXIDATIVE COUPLING OF METHANE ON SUPERCONDUCTOR-TYPE CATALYTIC MATERIALS

Oxidative coupling of methane to higher hydrocarbons was investigated using alkali and rare earth cuprates such as YBa₂Cu₃O_7-x, La_1.8Ba_0.2CuO and La₂CuO₄. Oxygen and methane in helium were fed to the reactor in a cofeed mode. Approximately, 5 g of catalyst in powder form was placed in a quartz flow reactor in all experiments. Oxygen partial pressure was changed as a parameter (P₀ = 0.5 to 9.1 kPa) while keeping methane partial pressure and temperature constant at 18kPa and 1023 K respectively. Investigation of catalytic activity in terms of overall methane conversion and C₂ + (C₂H₄+C₂H₆) product selectivity indicated that higher conversions and lower selectivities were obtained as O₂ partial pressure was increased at a constant methane partial pressure of 8kPa. In comparing the performance of the two catalysts, La_1.8Ba_0.2CuO and La₂CuO₄; the selectivity results indicated a positive influence of incorporation of Ba into La₂CuO₄ structure. Similarly, selectivity values substantially increased teaching 86.3% at a reaction temperature of 1023 K and at P_CH4./P_O3, = 6 when La was replaced by Y and Ba.     

Stress calculations on diamond surfaces

Calculations were carried out to evaluate stresses for atoms located in the top several layers of the (100)-(1 × 1), (100)-(2 × 1) and (111)-(1 × 1) surfaces of diamond. Only equilibrated surfaces were taken into consideration in this investigation. Stress values in the direction perpendicular to the exposed surface vanish. In lateral directions, however, stresses have non-vanishing values, in general. For the (100) surfaces calculated stress values are anisotropic. While the (2 × 1) reconstructed surface is under compression in both directions, calculations for the unreconstructed (1 × 1) plane produced a compressive stress in one direction and a slight tension in the other. On the (111) surface, isotropic and relatively low compressive stress values were found. Present calculations indicate that atoms located only in a few top layers have lateral excess stresses which vanish very quickly for the atoms of interior layers as depart form the exposed surface.     

An ant colony optimization algorithm for load balancing in parallel machines with sequence-dependent setup times

This study introduces the problem of minimizing average relative percentage of imbalance (ARPI) with sequence-dependent setup times in a parallel-machine environment. A mathematical model that minimizes ARPI is proposed. Some heuristics, and two metaheuristics, an ant colony optimization algorithm and a genetic algorithm are developed and tested on various random data. The proposed ant colony optimization method outperforms heuristics and genetic algorithm. On the other hand, heuristics using the cumulative processing time obtain better results than heuristics using setup avoidance and a hybrid rule in assignment.     

Oxidative coupling of methane over NbO (p-type) and Nb2O5 (n-type) semiconductor materials

Oxidative coupling of methane to higher hydrocarbons was investigated using two types of semiconductor catalysts, NbO (p-type) and Nb₂O₅ (n-type) at 1 atm pressure. The ratio of methane partial pressure to oxygen partial pressure was changed from 2 to 112 and the temperature was kept at 1023 K in the experiments conducted in a cofeed mode. The results indicated a strong correlation between C₂₊ selectivity performance and the electronic properties of the catalyst in terms of p-vs. n-type conductivity. The p-type semiconductor catalyst, NbO, had a larger selectivity (e.g. 95.92%) over the n-type Nb₂O₅ catalyst (23.08%) both at the same methane conversion of 0.64%. Catalyst characterization via X-ray diffraction, TGA and reaction studies indicated that NbO was transformed to Nb₂O₅ during the course of the reaction which limits catalyst life.     

Automatic expression spotting in videos

In this paper, we propose a novel solution for the problem of segmenting macro- and micro-expression frames (or retrieving the expression intervals) in video sequences, which is a prior step for many expression recognition algorithms. The proposed method exploits the non-rigid facial motion that occurs during facial expressions by capturing the optical strain corresponding to the elastic deformation of facial skin tissue. The method is capable of spotting both macro-expressions which are typically associated with expressed emotions and rapid micro- expressions which are typically associated with semi-suppressed macro-expressions. We test our algorithm on several datasets, including a newly released hour-long video with two subjects recorded in a natural setting that includes spontaneous facial expressions. We also report results on a dataset that contains 75 feigned macro-expressions and 37 feigned micro-expressions. We achieve over a 75% true positive rate with a 1% false positive rate for macro-expressions, and a nearly 80% true positive rate for spotting micro-expressions with a .3% false positive rate.     

Plasmon-enhanced solar water splitting with metal oxide nanostructures: A brief overview of recent trends

In the last decade, the surface plasmon resonance-enhanced solar water splitting (SWS) has been actively investigated for improved hydrogen production. In this mini-review, we briefly introduce the mechanisms for plasmon-enhanced SWS and then review some representative studies related to these mechanisms. In addition, we also briefly discuss how metal oxide geometry affects the SWS activity in combined metal-semiconductor nanostructures. Finally, we summarize the recent discoveries and proposed a future vision for plasmon-enhanced SWS with metal oxide nanostructures.     

Effect of pH,flow rate and concentration on the sorption of Pb and Cd on montmorillonite: I. Experimental

Continuous column adsorption of lead (Pb) and cadmium (Cd) was studied using pH adjustment and calcium‐saturated montmorillonite in a short stainless steel column. Changing either pH or flow rate, while keeping inlet concentration of the ions constant, led to considerable changes in effluent concentrations and breakthrough curves (BTCs). At low pH values (2–4), H⁺ ions competed strongly with lead and cadmium ions; at intermediate pH (4–6), ionic size played the major role in adsorption and ion exchange and at high pH (6–9) precipitation was the major process taking place especially for lead sorption. At low flow rates less than 0.5 cm³ min⁻¹, sorption of both lead and cadmium increased due to the long retention time in the column. When both lead and cadmium ions were present in the feed, adsorption remained the same while that of cadmium decreased compared with single ion experiments. © 1999 Society of Chemical Industry     

Implementation of an electrolysis system with DC/DC synchronous buck converter

A synchronous buck DC–DC converter that can be used to produce hydrogen through electrolysis by using the energy generated from renewable energy sources has been designed and implemented. The reason for selecting this topology is that the voltage level at the output of renewable sources, such as solar cells and storage batteries, is about 12 V DC, and the voltage level required for electrolysis is about 2 V DC. Traditional buck converters have low efficiencies at low output voltages since the voltage drops on the components are comparable to the output voltage. The converter has been designed and tested at 25 A output current. Two different electrodes were used for electrolysis and the effect of electrode opening on the operation was observed. In addition, the stability analysis of non-linear electrolysis system load has been performed.