Assessing the opportunities of landfill mining

Long-term estimates make clear that the amount of solid waste to be processed at landfills in the Netherlands will sharply decline in coming years. Major reasons can be found in the availability of improved technologies for waste recycling and government regulations aiming at waste reduction. Consequently, market size for companies operating landfills shrinks. Among the companies facing the problem is the Dutch company Essent. Given the expected market conditions, it looks for alternative business opportunities. Landfill mining, i.e., the recycling of existing landfills, is considered one of them. Proceeds of landfill mining are related to, for example, recycled materials available for re-use, regained land, and possibilities for a more efficient operation of a landfill. The market for landfill mining is of a considerable size – there are about 3800 landfills located in the Netherlands. Given market size Essent faces the dilemma of how to explore this market, i.e., select the most profitable landfills in a fast and efficient way. No existing methods or tools could be found to do so. Therefore, to answer to the problem posed, we propose a step-wise research method for market exploration. The basic idea behind the method is to provide an adequate, cost-saving and timely answer by relying on a series of quick scans. The method has been tested for its practical use in a pilot study. The pilot study addressed 147 landfills located in the Dutch Province of Noord-Brabant. The study made clear how method application resulted in the selection of a limited number of high potential landfills in a few weeks, involving minimal research costs.

Wireless Power Transfer to Biomedical Implants Using a Class-E Inverter and a Class-DE Rectifier

In this article, we propose a strategy for the design of a wireless power transfer system consisting of a class-E inverter, a half-bridge class-DE rectifier, and two coupled coils. The system is optimized for maximum power transfer efficiency. The design is validated via a case study, for which a wireless power transfer link to a neuroprosthesis was designed. After circuit simulations, a prototype was realized and measured. There is a good agreement between the calculated, simulated and measured voltages and currents. The prototype delivers 80 mW, 7 V to a biomedical implant at 6.78 MHz, the transfer efficiency is 52 to 68%, depending on the alignment. The end-to-end efficiency, with the controller and gate driver also taken into account, is 39 to 57%. Electromagnetic and thermal simulations were performed to verify compliance with relevant safety regulations on specific absorption rate (SAR) levels, magnetic field strength, and heat generation in the implant, for separation distances between the coils of 8 to 15 mm, and transverse misalignment from 0 to 15 mm.</p

Effect meerjarige toepassing groenbemester en organische mest op bodemkwaliteit bij continuteelt maïs : 2e rapport project Zorg voor Zand

In 2005 is onderzoek gedaan naar het effect van meerjarige toepassing van groenbemester en organische bemesting op diverse bodemkwaliteitskenmerken bij continuteelt van snijmaïs op zandgrond. De conclusie is dat het effect op de bodemkwaliteit en gewasopbrengst van organische bemesting wat groter was dan van groenbemester. De biologische activiteit werd nauwelijks beïnvloed door beide behandelingen

Paardenhouderijen vergeleken: out of the box

In deze brochure worden verschillende paardenhouderijsystemen vergeleken op belangrijke duurzaamheidsaspecten. In de afgelopen jaren zijn er enkele nieuwe paardenhouderijsystemen op de markt gekomen, zoals de ‘Hit actief stal’ (bewegingsstal) en ‘Paddockparadijs’. Deze nieuwe systemen claimen duurzamer te zijn, waarbij het welzijn van de paarden voorop staat. Daarnaast zijn bij een aantal systemen een hogere arbeidsefficiëntie en lagere investeringskosten belangrijke uitgangspunten. Om de systemen te kunnen vergelijken en vast te stellen of deze systemen bijdragen aan een verduurzaming van de paardenhouderij is allereerst een beschrijving nodig van de traditionele systemen en de nieuwe systemen. In deze brochure worden de traditionele- en nieuwe paardenhouderijsystemen beschreven en vergeleken

CFU-S(11) activity does not localize solely with the aorta in the aorta-gonad-mesonephros region

The aorta-gonad-mesonephros (AGM) region is a potent hematopoietic site in the midgestation mouse conceptus and first contains colony-forming units-spleen day 11 (CFU-S(11)) at embryonic day 10 (E10). Because CFU-S(11) activity is present in the AGM region before the onset of hematopoietic stem cell (HSC) activity, CFU-S(11) activity in the complex developing vascular and urogenital regions of the AGM was localized. From E10 onward, CFU-S(11) activity is associated with the aortic vasculature, and is found also in the urogenital ridges (UGRs). Together with data obtained from organ explant cultures, in which up to a 16-fold increase in CFU-S(11) activity was observed, it was determined that CFU-S(11) can be increased autonomously both in vascular sites and in UGRs. Furthermore, CFU-S(11) activity is present in vitelline and umbilical vessels. This, together with the presence of CFU-S(11) in the UGRs 2 days before HSC activity, suggests both temporally and spatially distinct emergent sources of CFU-S(11). (Blood. 2000;96:2902-2904

Insights into the fabrication and structure of plutonium pyrochlores

Rare earth zirconates, such as Nd2Zr2O7, crystallise with the pyrochlore structure and are a group of materials which have been suggested as potential nuclear waste forms for actinide immobilisation. In this work, a new hydroxide co-precipitation route is presented to investigate the incorporation of Pu into Nd2Zr2O7. The plutonium content was varied between 5 and 10 mol% and the structural uptake and Pu oxidation state were probed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray absorption spectroscopy (XAS). The experimental findings were complemented by DFT ab initio calculations. For all the incorporation mechanisms studied PuO2 was used as the reference reactant state to allow for a direct comparison between the possible Pu uptake scenarios. Analysis of the experimental data suggests that Pu(IV) cations substitute for Nd(III) cations leading to structural distortion of the pyrochlore A-sites. The computed solution energies and bond-distances corroborate the experimental findings and indicate that the excess charge is balanced via the introduction of oxygen at formerly vacant sites