A mechanism for solvent extraction of first row transition metals from chloride media with the ionic liquid tetraoctylammonium oleate

The extraction mechanism of cobalt, nickel and zinc with the ionic liquid tetraoctylammonium oleate is reported.

Reverse movement and coalescence of water microdroplets in electrohydrodynamic atomization

When a high voltage is applied to a liquid pumped through a needle, charged microdroplets can be formed, which are carried along the electric field lines. This phenomenon is called electrohydrodynamic atomization (EHDA), or simply electrospray. In this work we show that in the case of water, droplets may reverse their paths flying back toward the liquid meniscus, sometimes making contact with it. Such reverse movement is caused by polarization of the water inside the strong electric field. To understand this phenomenon we developed a way to calculate the droplet charge using its trajectory obtained by high-speed imaging. The values found showed that these droplets are charged between 2.5% and 19% of their Rayleigh limit.

Electrical power from sea and river water by reverse electrodialysis: a first step from the laboratory to a real power plant

Electricity can be produced directly with reverse electrodialysis (RED) from the reversible mixing of two solutions of different salinity, for example, sea and river water. The literature published so far on RED was based on experiments with relatively small stacks with cell dimensions less than 10 × 10 cm(2). For the implementation of the RED technique, it is necessary to know the challenges associated with a larger system. In the present study we show the performance of a scaled-up RED stack, equipped with 50 cells, each measuring 25 × 75 cm(2). A single cell consists of an AEM (anion exchange membrane) and a CEM (cation exchange membrane) and therefore, the total active membrane area in the stack is 18.75 m(2). This is the largest dimension of a reverse electrodialysis stack published so far. By comparing the performance of this stack with a small stack (10 × 10 cm(2), 50 cells) it was found that the key performance parameter to maximal power density is the hydrodynamic design of the stack. The power densities of the different stacks depend on the residence time of the fluids in the stack. For the large stack this was negatively affected by the increased hydrodynamic losses due to the longer flow path. It was also found that the large stack generated more power when the sea and river water were flowing in co-current operation. Co-current flow has other advantages, the local pressure differences between sea and river water compartments are low, hence preventing leakage around the internal manifolds and through pinholes in the membranes. Low pressure differences also enable the use of very thin membranes (with low electrical resistance) as well as very open spacers (with low hydrodynamic losses) in the future. Moreover, we showed that the use of segmented electrodes increase the power output by 11%.

Significant DQw1 association in achalasia

Achalasia is a neuromuscular disorder of the esophagus with unknown etiology. There have been suggestions that this disorder is immunologically mediated. To examine this possibility, HLA phenotyping was prospectively performed on 40 patients with documented achalasia (24 Caucasian, 16 blacks). Results showed a positive association for the class II HLA antigen, DQw1, with 83% of Caucasians (P less than 0.02) and 86% of blacks having the antigen (NS). The relative risk for developing achalasia with the presence of DQw1 was 4.2 in Caucasians and 3.6 in blacks. A negative correlation for the DRw53 antigen was noted in Caucasian patients with a relative risk of 0.23. These results indicate an immunogenetic association for achalasia and provide insight into the pathogenesis of this disorder.