Effect of sponge volume fraction on the performance

A novel fluidized bed bioreactor (FBBR) was designed by integration of anaerobic granular activated carbon and aerobic sponge reactors. This FBBR was evaluated at different sponge volume fractions for treating a synthetic wastewater. Polyester urethane sponge with cube size of 1 × 1 × 1 cm and density of 28-30 kg/m3 with 90 cells per 25 mm was used as biomass carrier. The results indicate that the FBBR could remove more than 93% of dissolved organic carbon (DOC). The highest nutrient removal efficiencies (58.2% PO4 -P and 75.4% NH4-N) were achieved at 40% sponge volume fraction. The system could provide a good condition for biomass growth (e.g. 186.2 mg biomass/g sponge). No significant different performance in specific oxygen uptake rate was observed between 30, 40, and 50% sponge volume fractions. © IWA Publishing 2013 Water

A current assessment of the Hamburg rules

Trade has been booming. The WTO ( World Trade Organisation) estimated that world trade in goods grew 8 % in volume terms last year, this being four times the growth of world GDP (Gross Domestic Products). During the 1990s international trade has grown far faster than world output, showing that national economies are becoming more closely linked. Foreign direct investment, another gauge of international economies integration, is also soaring: last year, estimated the United Nations Conference on Trade and Development, cross border investment increased by 40%, to $315 billion

Migration Paradigm Shifts and Transformation of Migrant Communities: The Case of Dutch Kiwis

This paper explores the dynamics of Dutch community change in New Zealand since 1950. The Netherlands has been the largest source country of migrants from continental Europe to New Zealand, but by 2006 40 percent of the Netherlands born were aged 65 or older. We find that there are three distinct cohorts of these migrants, each covering roughly 20 years of arrivals: a large cohort of post-war migrants (those who arrived in the 1950s and 1960s), and much smaller cohorts of skilled migrants (those who arrived in the 1970s and 1980s), and transnational professionals (those who arrived in the 1990s or more recently). Early migrants were mostly younger arrival, more religious, less educated and had more children than the subsequent cohorts. More recent migrants are increasingly highly qualified and in high-skill occupations. "Dutch Kiwis" are more geographically dispersed than other immigrants, and more recent arrivals are relatively more often located in rural areas. This transformation of the Dutch community in New Zealand can be linked to global and New Zealand/Netherlands specific changes that have conditioned the character and volume of the migrant flows and the dynamics of migrant community development.globalisation, push and pull factors of migration, ageing of migrant communities, migrant integration, cohort analysis

Optical sensing in microchip capillary electrophoresis by femtosecond laser written waveguides

Capillary electrophoresis separation in an on-chip integrated microfluidic channel is typically monitored with bulky, bench-top optical excitation/detection instrumentation. Optical waveguides allow confinement and transport of light in the chip directing it to a small volume of the microfluidic channel and collecting the emitted/transmitted radiation. However, the fabrication of optical waveguides or more complex photonic components integrated with the microfluidic channels is not a straightforward process, since it requires a localized increase of the refractive index of the substrate.\ud Recently, a novel technique has emerged for the direct writing of waveguides and photonic circuits in transparent glass substrates by focused femtosecond laser pulses.\ud In this work we demonstrate the integration of femtosecond laser written optical waveguides into a commercial microfluidic chip. We fabricate high quality waveguides intersecting the microchannels at arbitrary positions and use them to optically address with high spatial selectivity their content. In particular, we apply our technique to integrate optical detection in microchip capillary electrophoresis. Waveguides are inscribed at the end of the separation channel in order to optically excite the different plugs reaching that point; fluorescence from the labelled biomolecules crossing the waveguide output is efficiently collected at a 90° angle by a high numerical aperture optical fiber. The sensitivity of the integrated optical detection system was first evaluated filling the chip with a dye solution, obtaining a minimum detectable concentration of 40 pM. \ud After dynamic coating of the microchannels with an EPDMA polymer we demonstrate electrophoresis of an oligonucleotide plug with concentration down to 1 nM and wavelength-selective monitoring of on-chip separation of three fluorescent dyes. Work is in progress on separation and detection of fluorescent-labeled DNA fragments, targeting specific, diagnostically relevant regions of a template DNA, for application to the detection of chromosome aberrations