Characterization of activated carbon produced from almond shell and hazelnut shell

Ammonium chloride-impregnated and untreated almond shell and hazelnut shell samples were carbonized in a flow of nitrogen at relatively low temperatures. Pore structure characterization and sorption capacities of activated carbons prepared from shells of almond and hazelnut indicated that treatment with NH₄Cl increased the total surface area and improved sorption characteristics. Chemical activation carried out at 350°C gave products with surface area values above 500 m² g^?1. On the other hand, the surface area values observed for the products obtained from untreated raw materials were about half of this value. The surface area of products obtained from NH₄Cl-impregnated samples reached values of over 700 m² g^?1 when the carbonization temperature was increased 700°C.     

Carrageenin granuloma in the plaice (Pleuronectes platessa); a histopathological study of chronic inflammation in a teleost fish

The protein component of tissue thromboplastib (Factor III) from human brain was purified by extraction of a microsomal fraction with sodium deoxycholate, gel filtration of the extract on Sephadex G-100 and preparative polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. The product, apoprotein III, was homogeneous by anayltical polyacrylamide-gel electrophoresis, and it induced monospecific antibodies in rabbits and goat as shown by immunodiffusion and immunoelectrophoresis. Amino acid- and carbohydrate-analysis data for apoprotein III are presented. The carbohydrate moiety of the protein consists of fucose, mannose, galactose, N-acetylglucosamine and N-acetylneuraminate, amounting to a total content of 6.3g/100g. The apoprotein alone had no procoagulant activity. When Factor III was reconstituted by combining the pure apoprotein with a purified lipid fraction from the deoxycholate extract of crude Factor III, a high and optimal procoagulant activity was obtained at a phospholipid/protein ratio of 1.1g/g. Phosphatidylethanolamine alone had a weak but significant ability to restore activity, whereas phosphatidylcholine and phosphatidylserine separately had almost none. Two-component mixtures were on average more effective, and three-component mixtures far more effective, than the single phospholipids. The inclusion of a small amount of phosphatidylserine was very important for high activity.     

Color-tunable properties of Eu3+- and Dy3+-codoped Y2O3 phosphor particles

Rare-earth phosphors are commonly used in display panels, security printing, and fluorescent lamps, and have potential applications in lasers and bioimaging. In the present study, Eu³⁺- and Dy³⁺-codoped uniform-shaped Y₂O₃ submicron particles were prepared using the urea homogeneous precipitation method. The structure and morphology of the resulting particles were characterized by X-ray diffraction, field emission scanning electron microscope, and field emission transmission electron microscope, whereas their optical properties were monitored by photoluminescence spectroscopy. The room-temperature luminescence color emission of the synthesized particles can be tuned from red to yellow by switching the excitation wavelength from 254 to 350 nm. The luminescence intensities of red and yellow emissions could be altered by varying the dopant concentration. Strong quenching was observed at high Eu³⁺ and Dy³⁺ concentrations in the Y₂O₃ host lattice.     

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.     

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.