Physical solvent extraction of levulinic acid from dilute aqueous solution with 2-methyltetrahydrofuran

The results of the present investigation reveal that 2-methyltetrahydrofuran is a potential solvent for the extraction of levulinic acid from dilute aqueous solution. This conclusion is based on the relatively high values of distribution coefficient K_d (1.3-1.6) measured for the system of levulinic acid – water – 2-methyltetrahydrofuran at temperatures 298.2 K, 313.2 K, and 328.2 K, as well as encouraging performance of the continuous counter current Kühni column. The results give reason to believe, that 2-methyltetrahydrofuran can be considered for the extraction of other low molecular weight acids, such as formic or lactic acid, as well.     

Real-time effective density monitor (DENSMO) for aerosol nanoparticle production

A new instrument, density monitor (DENSMO), for aerosol particle size distribution characterization and monitoring has been developed. DENSMO is operationally simple and capable of measuring the effective density as well as the aerodynamic and the mobility median diameters with a time resolution of 1 s, from unimodal particle size distributions. The characterization is performed with a zeroth order mobility analyzer in series with a low pressure impactor and a filter stage. The operation of DENSMO was investigated with sensitivity analysis and, based on the results, optimal operation parameters were determined. DENSMO was also compared, in lab test measurements, against a reference method with several particle materials with bulk densities from 0.92 to 10.5 g/cm³. The results show that the deviation from the reference method was less than 25% for suitable materials.

Copyright © 2016 American Association for Aerosol Research     

Total hordatine content in different types of beers

Hordatines are phenolic secondary metabolites typical of barley. Hordatines withstand at least moderate processing, and thus they are also found in barley malts and beer. So far, no published data on the hordatine content has been available in beers or different styles of beer. The aim of this study was to produce information on the total hordatine content in beers and statistically compare the hordatine content of different beer types. In the current study, hordatines were analysed in 208 beers by high‐performance liquid chromatography equipped with a diode array detector (HPLC‐DAD). The average total hordatine content of all beer samples was 5.6 ± 3.1 mg L^?1 as p‐coumaric acid equivalents (PCAE), with a minimum values 0 to a maximum value 18.7 mg L^?1 PCAE. The total hordatine content correlated positively to the alcohol content in lagers, ales, stouts and porters, but not in wheat beers. There was no statistically significant difference in hordatine content in different types of beer, excluding the non‐alcoholic group of beers. It is noteworthy that non‐alcoholic beers also contained hordatines. More research would be needed to understand how parameters, such as mashing, should be chosen in order to achieve maximum recovery of hordatines in wort and beer.     

EOC: Electronic Building Blocks for Embedded Systems

The embedded-object concept, EOC, applies common object-oriented software methods to Lego-like hardware-software entities. These modular entities, representing objects in object-oriented design, function as electronic building blocks that can be assembled into new embedded systems. The goal of the EOC is to make embedded-system design faster and easier while preserving the commercial applicability of the resulting devices.     

Influence of wind power,plug-in electric vehicles,and heat storages on power system investments

Due to rising fuel costs, the substantial price for CO₂ emissions and decreasing wind power costs, wind power might become the least expensive source of power for an increasing number of power systems. This poses the questions of how wind power might change optimal investments in other forms of power production and what kind of means could be used to increase power system flexibility in order to incorporate the variable power production from wind power in a cost-effective manner.