CDA: a novel multicore scheduling for cost-aware deadline-constrained scientific workflows on the IaaS cloud

The Journal of Supercomputing - The variety of pricing models offered by cloud service providers and the availability of a wide diversity of computing resources has increased the popularity of this...     

Influence of network-based structural and power diversity on research performance

Scientometrics - With an increase in studies of actors’ collaborative activities on their performance very few have examined the role of the structural influence of actors on their...     

Characterization of corn stover, distiller grains and cattle manure for thermochemical conversion

Corn stover, distiller grains and cattle manure were characterized to evaluate their acceptability for thermochemical conversion. The energy densities of ground corn stover, distiller grains and cattle manure after totally drying were 3402, 11,813 and 10,374 MJ/m³, compared to 37,125 MJ/m³ for coal. The contents of volatiles in corn stover, distiller grains and cattle manure were 77.4, 82.6 and 82.8%, respectively, on a dry and ash-free basis compared to 43.6% for coal. About 90% of the volatiles in corn stover, distiller grains and cattle manure were released at pyrolysis temperatures of 497, 573 and 565 °C, respectively. The combustion of corn stover, distiller grains and cattle manure were completed at 620, 840 and 560 °C, respectively. The heat values of the biomass and air mixture for stoichiometric combustion were 2.64, 2.75 and 1.77 MJ/kg for dried corn stover, distiller grains and cattle manure, respectively, as compared to 2.69 MJ/kg for coal. Combustion of 1 kg of dry corn stover, distiller grains and cattle manure generated 5.33, 6.20 and 5.66 Nm³ of flue gas, respectively, compared to 8.34 Nm³ for coal. Simulation showed that gasification of 1 kg of dried corn stover, distiller grains and cattle manure at 850 °C and ER of 0.3 generated 2.02, 2.37 and 1.44 Nm³ dry syngas at a heating value of about 4.5 MJ/Nm³, compared to 3.52 Nm³ at 5.8 MJ/Nm³ for coal. The molecular ratio of H₂ to CO in the biomass-derived syngas was close to 1.0, compared to about 0.5 for the coal-derived syngas.     

Simulation of depth and wind effects on the hydraulic efficiency of sedimentation tanks

In this research, we aim to investigate the effects of the depth and wind effect on the surface of water on the hydraulic efficiency of the sedimentation tanks in water and wastewater treatments plants. A verified two‐dimensional numerical study was performed to evaluate hydraulic performance of series settling tanks by four different depths of 2.5, 3, 3.5 and 4 (m). Wind velocities of 5 and 7 (m/s) in co‐current and counter‐current direction of water flow in sedimentation tank were applied on the surface of the water. In this study, k–ε turbulent model and passive scalar tracer were used to perform the simulations. The research confirms that wind influence on the surface of water causes recirculation zones and increases the length of recirculation zones. In both windy and normal situation, the Real Hydraulic Retention Time and the effective volume of sedimentation tanks increases widely as the depth of the tank.     

Organic-inorganic nanocomposites of methylcellulose as a precursor of nanocrystalline ZnO layers

In this article, we present a sol-gel method to synthesize hybrid nanocomposite films of Zinc oxide (ZnO)/methylcellulose (MC) on microscope glass slides. The zinc/MC solutions were prepared, using different weight ratios of zinc acetate dihydrate to MC, in the presence of acetic acid. Fourier transform infrared spectroscopy (FTIR) investigation of the Zn sol/MC mixture showed coordinating interaction between zinc ions and MC. Thermal gravimetry analysis (TGA) results showed rapid decomposition of organic compounds in the composites at the temperature range of 200-450 degrees C. The UV-Vis spectroscopy was also utilized to identify ZnO nanoparticles in the MC matrix. The generation of ZnO nanoparticles in the MC matrix was then observed to proceed in situ through the annealing of the gel phase at 200 degrees C. Nanocrystalline films of ZnO/MC were subsequently obtained by the calcinations of ZnO/MC nanocomposites at 550 degrees C. The nanocomposite films were transparent in the visible light and showed a higher energy absorption edge compared with the bulk ZnO. Nanocrystallite sizes of ZnO particles were estimated from scanning electron microscopy (SEM) and the X-ray diffraction (XRD) investigations.     

SOLUBILITY OF ACETAMINOPHEN AND IBUPROFEN IN BINARY AND TERNARY MIXTURES OF POLYETHYLENE GLYCOLS 200 AND 400, PROPYLENE GLYCOL,AND WATER AT 25°C

The solubilities of acetaminophen and ibuprofen in the mixtures of propylene glycol-water, polyethylene glycols 200- and 400-propylene glycol, and polyethylene glycols 200- and 400-propylene glycol-water (122 data points) at 25°C were determined and mathematically represented by the Jouyban-Acree model. The solubilities were measured using the shake flask method, and the model was used to fit the solubility data of each drug in the solvent mixtures. The density of the solute-free solvent mixtures was measured and the density of the drug-saturated solutions was predicted. The obtained overall mean relative deviations (OMRDs) for fitting the solubility data of acetaminophen and ibuprofen in binary mixtures are 1.5% and 11.7%, respectively. The OMRDs for fitting the solubilities in ternary solvent mixtures for acetaminophen and ibuprofen are 16.3% and 42.0%, respectively, and the OMRD values for predicting all solubilities of acetaminophen and ibuprofen by these trained versions of the Jouyban-Acree model were 5.7% and 20.4%, respectively. The prediction OMRD for the density of saturated solutions was 2.5%.     

Modified covariance intersection for data fusion in distributed nonhomogeneous monitoring systems network

Monitoring networks contain monitoring nodes that observe an area of interest to detect any possible existing object and estimate its states. Each node has characteristics such as probability of detection and clutter density that may have different values for distinct nodes in nonhomogeneous monitoring networks. This paper proposes a modified covariance intersection method for data fusion in such networks. It is derived by formulating a mixed game model between neighbor monitoring nodes as players and considering the inverse of the trace of fused covariance matrix as players' utility function. Monitoring nodes estimate the states of any possible existing object by applying joint target detection and tracking filter on their own observations. Processing nodes fuse the estimated states received from neighbor monitoring nodes by the proposed modified covariance intersection. It is validated by simulating target detection and tracking problem in 2 situations: 1 target and unknown number of targets.     

Partial Oxidation and Dry Reforming of Methane Over Ca/Ni/K(Na) Catalysts

Partial oxidation and dry reforming of methane to synthesis gas over Ca/Ni/K(Na) catalysts have been studied. Effects of temperature, pressure, and oxygen/methane ratios on catalytic activity, selectivity, and carbon formation have been determined. Also reforming of ¹³CH₄ in the presence of CO₂ and Temperature-Programmed Oxidation (TPO) of deposited carbon after the reaction indicated that both methane and CO₂ contribute to carbon formation. The TPO of deposited carbon on Ca/Ni/K catalyst showed that the catalyst consumed a significant amount of oxygen, only a fraction of which was consumed by carbon species on the surface, indicating that the surface oxygen plays a significant role in oxidizing and removing carbon species from the catalyst surfaces     

Sustained drug release using supramolecular hydrogels composed of cyclodextrin inclusion complexes with PCL/PEG multiple block copolymers

Methadone hydrochloride is a narcotic drug used to relieve chronic pain and control withdrawal symptoms in people undergoing detoxification for opiate addiction, but poses some limits. To reduce the limits and increase the drug’s effectiveness, supramolecular hydrogels composed of α-CD (α-cyclodextrin) and PCL/PEG (polycaprolactone/polyethylene glycol) copolymers, which gained attention due to their advantages, were chosen in this study as controlled-release formulations. PCL/PEG/PCL and PCL/PEG copolymers were synthesized by a microwave-assisted method and then supramolecular hydrogels were prepared by mixing the solutions of copolymers/drug and α-CD to make a methadone hydrochloride sustained-release system. Effects of the drug, copolymer, and α-CD concentrations and copolymer structure on gelation time were also investigated. The systems had rheological properties that depended on copolymer construction and component concentrations. The microwave-assisted method provides an accelerated synthesis of the copolymers with yield of 57 % and low level of impurities. The supramolecular hydrogels demonstrated shear thinning and thixotropic behavior and regained their networks quickly after passing through a fine needle. Due to the porous construction of supramolecular hydrogels, they swell in the presence of fluids and absorb large quantities of water, thereby making the system comprehensively biocompatible. In this study, supramolecular hydrogels composed of α-CD with tri- and di-block copolymers were investigated and found to have rheological properties that depended on copolymer construction and component concentrations. Changing one parameter alone like copolymer or α-CD concentration or the length of blocks could not significantly affect on the drug release, but combination of these factors was efficient. Results of the present study indicated that supramolecular hydrogels composed of α-CD and PCL/PEG copolymers are appropriate drug delivery systems that can release methadone hydrochloride in a sustained manner.     

A comparative study on the effects of material blending method on the physico‐mechanical properties of WPCs made from MDF dust

The present study was carried out to investigate the effect of material ‐ blending method and filler content on the physical and mechanical properties of medium density fiberboard (MDF) dust/PP composites. In the sample tests preparation, 40, 50, and 60 wt % of MDF dust were used as lignocellulosic material. Test samples were made to measure the influence of material ‐ blending method and MDF dust content on water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), modulus of rupture (MOR), tensile strength, tensile modulus, and withdrawal strengths of fasteners. The mechanical properties of the test panels significantly decreased with increasing MDF dust contents due to the reduction of interface bond between the fiber and polymer matrix. The WA and TS values also increased by increasing the amount of MDF dust. So with the increase in the MDF dust content, there are more water residence (high hydroxyl groups (? OH) of cellulose and hemicelluloses) sites, thus more water is absorbed, so it can reduce mechanical strength. Furthermore, the results indicated that the physical and mechanical properties of samples made with melt ‐ blend method were more acceptable than those of dry ‐ blend method. Field emission scanning electron microscopy micrographs also showed that the polymer and the filler phase mixed better in the melt ‐ blend method. On the basis of the findings of this research, it appears evident that certain amount of MDF dust material with suitable material ‐ blending method can be used in manufacturing of wood–plastic composites for providing good physical and mechanical properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40513.