209 research outputs found
Mild disintegration of the green microalgae Chlorella vulgaris using bead milling
No full textIn this work, the mild disintegration of the microalgae Chlorella vulgaris for the release of intracellular products has been studied. By means of bead milling the microalgae suspensions were successfully disintegrated at different biomass concentrations (25–145 gDW kg-1) over a range of agitator speeds (6–12 m s-1). In all cases over 97% of cell disintegration was achieved resulting in a release of water soluble proteins. A clear optimum rate of disintegration and protein release was observed at an agitator speed of 9–10 m s-1 regardless of the biomass concentration. Selective extraction of water soluble proteins was observed as proteins released sooner than cell disintegration took place. Proteins could be released at 85% lower energy input than for cell disintegration resulting in specific energy consumptions well below 2.5 kWh kgDW-1
Archeoldienst Rapport 4
No full textArcheologisch onderzoeksbureau Archeodienst Gelderland heeft in januari 2009 een Inventariserend Veldonderzoek (IVO) verkennende fase uitgevoerd aan de Oude Kluizeweg in Arnhem, gemeente Arnhem. De aanleiding voor dit onderzoek is het voornemen om een nieuw appartementencomplex op de locatie te gaan bouwen. Het grootste deel van het appartementencomplex zal onderkelderd gaan worden. Graafwerkzaamheden ten behoeve van deze ontwikkeling zullen zorgen voor een bodemverstoring tot een diepte van maximaal 4,0 m beneden maaiveld. De kans bestaat dat eventueel aanwezige archeologische waarden hierdoor verstoord dan wel vernietigd zullen worden.
Op basis van de resultaten van het Inventariserend Veldonderzoek wordt geadviseerd om geen vervolgonderzoek uit te laten voeren.
Ter hoogte van de boring met een intact bodemprofiel gaat de gemeente zelf en waarneming verrichten, vanwege de nabijheid van grafheuvels en prehistorische vondsten die zich boringen moeilijk laten duiden
THE TRANSITION OF MOLECULAR OXYGEN
No full textAuthor Institution: Research School of Physical Sciences and Engineering, The Australian National University; Molecular Physics Laboratory, SRI InternationalThe origin of the intensity of the transition of molecular oxygen, first observed recently by Eppink et al. [J. Chem. Phys. 108, 1305 (1998).], is discussed. It is shown that the transition borrows its intensity principally from the dipole-allowed transition, through spin-orbit mixing between the and states. Estimated continuum photoabsorption cross sections and discrete oscillator strengths for the system are presented
Understanding the salinity effect on cationic polymers in inducing flocculation of the microalga Neochloris oleoabundans
No full textA mechanistic study was performed to evaluate the effect of salinity on cationic polymeric flocculants, that are used for the harvesting of microalgae. The polyacrylamide Synthofloc 5080H and the polysaccharide Chitosan were employed for the flocculation of Neochloris oleoabundans. In seawater conditions, a maximum biomass recovery of 66% was obtained with a dosage of 90 mg/L Chitosan. This recovery was approximately 25% lower compared to Synthofloc 5080H reaching recoveries greater than 90% with dosages of 30 mg/L. Although different recoveries were obtained with both flocculants, the polymers exhibit a similar apparent polymer length, as was evaluated from viscosity measurements. While both flocculants exhibit similar polymer lengths in increasing salinity, the zeta potential differs. This indicates that polymeric charge dominates flocculation. With increased salinity, the effectivity of cationic polymeric flocculants decreases due to a reduction in cationic charge. This mechanism was confirmed through a SEM analysis and additional experiments using flocculants with various charge densities
Magasins Culturels
No full textRedesign of an industrial building northeast of Paris.RMITArchitectureArchitecture and The Built Environmen
Effect of temperature and energy input on PEF processing of the green microalgae Chlorella vulgaris
No full textMicroalgae are a promising source for proteins, lipids and carbohydrates for the cosmetic, nutraceutical, chemical, food/feed and biofuel industry. Biorefinery comprises the downstream processing of all products produced by microal-gae after cultivation. However severe conditions can affect the properties of some components. To preventthis, focus needs to be put on biorefinery techniques which are mild and effective. Among the cell disruption techniques, in the last 5 years PEF has been claimed to be promising for opening the cell and improving the extraction of intracellular compo-nents/organelles.
In this study the microalgaeChlorella vulgaris was treated in a lab-scale continuous flow PEF unit.Biomass concentration was set at 25 g/L and PEF treated at 20 kV/cm.The effects of inlet temperature (25-65oC) and energy input (50-100 kJ/kg) on the release of proteins, sugars, antioxidants and pigments in the aqueous phase was investigated. With respect to the con-trol experiments carried out without electrical pulses, up to 2 g/L of carbohydrates and 1 g/L of protein were released in the aqueous phase when PEF was carried out at both the highest temperature and highest energy input
Passend strategisch denken: over tegenstellingen in de theorie en modieuze opvattingen in de praktijk
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