Recent advances in the production of γ-valerolactone from biomass-derived feedstocks via heterogeneous catalytic transfer hydrogenation

γ-valerolactone (GVL) is an important intermediate chemical with a wide range of applications as fuel, fuel additive and as a green solvent which has received a great deal of attentions from both academia and industry. This review aims to summarise the advances in conversion of renewable feedstocks into GVL through heterogeneous catalytic transfer hydrogenation (CTH) with a strong emphasis on discussing preparation, characterisation and performance of the catalysts in order to provide a better understanding of various catalytic systems and also to compare them in terms of catalytic performance

LineKing : coffee shop wait-time monitoring using smartphones

This article describes LineKing, a crowdsensing system for monitoring and forecasting coffee shop line wait times. LineKing consists of a smartphone component that provides automatic and accurate wait-time detection, and a cloud backend that uses the collected data to provide accurate wait-time estimation. LineKing is used on a daily basis by hundreds of users to monitor the wait-times of a coffee shop in the University at Buffalo, SUNY. The novel wait-time estimation algorithms of LineKing deployed at the cloud backend provide median absolute errors of less than 3 minutes

Biorefineries for biofuel upgrading: A critical review

This study reviews the biofuel valorization facilities as well as the future importance of biorefineries. Biomass can be converted into useful biofuels and bio-chemicals via biomass upgrading and biorefinery technologies. A biorefinery is a facility that integrates biomass conversion processes to produce fuels, power, and chemicals from biomass. Biomass upgrading processes include fractionation, liquefaction, pyrolysis, hydrolysis, fermentation, and gasification. Upgraded bio-oil from biomass pyrolysis can be used in vehicle engines as fuel. The benefits of an integrated biorefinery are numerous because of the diversification in feedstocks and products. There are currently several different levels of integration in biorefineries which adds to their sustainability, both economically and environmentally. Economic and production advantages increase with the level of integration in the biorefinery.Biomass Biofuel Fractionation Upgrading Biorefining

Biomass pyrolysis for liquid fuels and chemicals: A review

797-804Biomass pyrolysis produces fuels and chemicals. Pyrolysis (conventional, fast and flash) can produce solid (charcoal), liquid (tar and other organics), and gaseous products (H₂, CO₂, CO) between 625 and 775 K. Charcoal yield decreases as temperature increases. Production of liquid products is maximum between 625-725 K

Importance of algae oil as a source of biodiesel

Algae are the fastest-growing plants in the world. Industrial reactors for algal culture are open ponds, photobioreactors and closed systems. Algae are very important as a biomass source. Algae will some day be competitive as a source for biofuel. Different species of algae may be better suited for different types of fuel. Algae can be grown almost anywhere, even on sewage or salt water, and does not require fertile land or food crops, and processing requires less energy than the algae provides. Algae can be a replacement for oil based fuels, one that is more effective and has no disadvantages. Algae are among the fastest-growing plants in the world, and about 50% of their weight is oil. This lipid oil can be used to make biodiesel for cars, trucks, and airplanes. Microalgae have much faster growth-rates than terrestrial crops. the per unit area yield of oil from algae is estimated to be from 20,000 to 80,0001 per acre, per year; this is 7-31 times greater than the next best crop, palm oil. The lipid and fatty acid contents of microalgae vary in accordance with culture conditions. Most current research on oil extraction is focused on microalgae to produce biodiesel from algal oil. Algal-oil processes into biodiesel as easily as oil derived from land-based crops. (C) 2010 Elsevier Ltd. All rights reserved

Synthesis of Some New Ciprofloxacin Hybrids as Potential Antimicrobial Agents

WOS: 000422654000003A new series of ciprofloxacin hybrid compounds as new type of antimicrobial agents were synthesized and evaluated for antibacterial activity against Gram-positive and Gram-negative bacteria

Accurate Determination Of Saturation Parameters For Cr\u3csup\u3e4+\u3c/sup\u3e-Doped Solid-State Saturable Absorbers

We describe a systematic, rigorous procedure for the determination of the optical absorption saturation parameters for Cr4+:YAG and Cr4+:forsterite crystals at 1064 nm. A rate-equation approach was used to analyze the cw and pulsed transmission data of several crystals by accounting for the transverse as well as longitudinal variation of the beam intensity, saturation effects, and excited-state absorption. Use of an iterative procedure whereby the cw and pulsed data were simultaneously analyzed led to a considerable reduction in the error for the determination of cross sections. The average value of the absorption cross section σa and the normalized excited-state absorption cross section fp = σesa/σa were determined to be 6.13 × 10-19 cm2 and 0.45, respectively, for Cr4+:fersterite and 19.6 × 10-19 cm2 and 0.06, respectively, for Cr4+:YAG. Detailed comparison was also made with previous saturation measurements in the literature. Our results further show that lumped models based on the thin-length approximation should be used with caution in the determination of cross sections, especially when the pump beam is tightly focused inside the absorber. © 2006 Optical Society of America