Recycling belite cement clinker from post-demolition autoclaved aerated concrete – assessing a new process

Increasing post-demolition autoclaved aerated concrete (pd-AAC) waste is mainly landfilled due to its physical properties and lacking recycling processes. A promising technology is the production of recycled belite cement clinker, which can partially substitute Portland cement clinker. This paper presents experimental data of recycled belite cement clinker production from pd-AAC that has been successfully demonstrated on technology readiness level 4–5 and its associated lifecycle assessment. Different supply chains for pd-AAC and energy are examined. The closed-loop pd-AAC recycling via the belite route that aims for Portland cement clinker substitution shows significant potential savings in environmental impacts. These savings could reach 0.77 kg CO2-Eq/kg pd-AAC compared to the status quo (landfilling) by using renewable electricity, and 0.34 kg CO2-Eq/kg pd-AAC by using natural gas. The gained reduction of around 13.5 % is significant considering that it is the result of substituting only 15.5 % of the overall input material

The (im?)possibility of a biological substrate for mental disorders

ACHTERGROND Er bestaat een tegenstelling tussen de ‘medische’ kijk op een psychiatrische aandoening (als gegevenheid van de natuur in de zin van een biologisch substraat) en de constructivistische visie. DOEL Onderzoeken hoe de constructivistische positie zich verhoudt tot deze medische kijk op psychiatrische aandoeningen. METHODE Een beschouwing gebaseerd op een conceptuele analyse, met name van het boek The social construction of what? (1999) van de Canadese wetenschapsfilosoof Ian Hacking. RESULTATEN Er blijken verschillende objecten van constructivistische analyses een rol te spelen bij psychiatrische aandoeningen, de aandoening zelf en het idee of concept van de aandoening. Deze verschillende objecten interacteren daarbij ook nog met elkaar. Deze interacties kunnen expliciet gemaakt worden door indifferente soorten te onderscheiden van interactieve soorten. Zo wordt duidelijk dat als een aandoening niet gedetermineerd wordt door een biologisch substraat, dit niet automatisch betekent dat zo’n aandoening geheel losstaat van een mensonafhankelijke natuur. CONCLUSIE Hackings filosofie biedt de mogelijkheid om voorbij te gaan aan de tegenstelling tussen de constructivistische positie en de medische kijk op psychiatrische ziekten. BACKGROUND: The constructivist position is often used for psychiatric diseases, in contrast with the general medical view. In the medical view a biological substrate is decisive for a classification as 'disease', which is not the case in the constructivist position. AIM: We investigate how both positions relate to each other in psychiatric diseases. METHOD: Analysis based on a conceptual analysis of Ian Hacking's book The Social Construction of What? (1999). RESULTS: Different objects ought to be distinguished in a constructivist analysis of psychiatric diseases; the disease itself and the idea or concept of that disease. These different objects interact with each other. These interactions can be made explicit by distinguishing interactive kinds from indifferent kinds. Doing so makes it clear that even if a disease is not determined by a biological substrate, this does not imply that a biological substrate is something completely separate from that disease. CONCLUSION: Hacking's philosophy makes it possible to move beyond the opposition between the medical and the constructivist account of psychiatric diseases by combining both accounts

Test des neuen PARIO-Gerätes zur automatisierten Schlämmkornanalyse auf Basis der ISP-Methode

Die Partikelgrößenverteilung ("particle size distribution", PSD) kennzeichnet eine der wichtigsten physikalischen Eigenschaften von Böden. Das Referenzverfahren zur Bestimmung des PSD beruht auf der durch Gravitation bedingten Sedimentation von Partikeln in einer anfänglich homogenen Suspension. Herkömmliche Methoden messen manuell (i) den Auftrieb eines schwimmenden Körpers in der Suspension zu verschiedenen Zeiten (Aräometer-Methode) oder (ii) die Feststoffmasse in extrahierten Suspensionsvolumina zu vorgegebenen Zeiten (Pipett-Methode). Beide Verfahren führen zu einer Störung des Sedimentationsprozesses und liefern nur wenige diskrete Daten der PSD. Durner et al. (2017) haben kürzlich eine neue automatisierte Methode zur Bestimmung der Partikelgrößenverteilung von Böden und Sedimenten aus Gravitationssedimentation enwickelt. Das "Integrale Suspensiondruckverfahren" (ISP) schätzt kontinuierliche Partikelgrößenverteilungen aus Sedimentationsexperimenten, indem die zeitliche Entwicklung des Suspensionsdrucks bei einer bestimmten Meßtiefe in einem Sedimentationszylinder aufgezeichnet wird. Das Verfahren erfordert keine manuelle Interaktion nach dem Start und somit keine spezialisierte Ausbildung des Laborpersonals und vermeidet jegliche Störung des Sedimentationsprozesses. Die Technik zur Durchführung dieser Experimente wurde von der Firma UMS AG, München, entwickelt und steht als Instrument mit der Bezeichnung PARIO zur Verfügung, das von der METER Group AG gehandelt wird. In diesem Vortrag wird die grundlegende Funktionsweise von PARIO aufgezeigt und Schlüsselkomponenten und Parameter der Technologie erläutert

Forests as Commons – Changing Traditions and Governance in Europe

Commons are complex institutions and exist across the world in a wide range of situations regarding locally developed governance and management systems of many different natural resources. For many people commons remain associated with Hardin’s theory concerning the “Tragedy of the Commons” (1968), in which he assumed that local users of a natural resource are unable to formulate governance and management structures concerning their own choices that took into account the long-term sustainability of the resource itself. As a result, Hardin articulated that the tragedy was that the resource would inevitably become degraded in such situations and that the solution was private or public ownership. However, across Europe many forests have for a very long period of time successfully been managed as commons, just as they have in many other parts of the world. This chapter has three main aims: It will provide an introduction to the various types of commons before going on to link the issue of commons to the traditional forest landscapes of Europe, and it will look at how the role of forests and forest landscapes has changed and how it may change further in the future

Capacity building for sustainable aquaculture and fisheries development in Myanmar

This report presents the results of a Dutch public-private capacity building (Knowledge to Knowledge or K2K) mission for fostering sustainable aquaculture and fisheries development in Myanmar. The objectives of the K2K mission were to: 1) analyse Myanmar’s aquaculture and fisheries knowledge infrastructure including a gap analysis; 2) identify future stakeholder needs and recommend improvements in terms of capacity building; 3) provide basic practical knowledge in support of a sustainable aquaculture and fisheries sector to Myanmar stakeholders; and 4) develop a Terms of Reference for a possible future programme aiming at building capacity for a sustainable fisheries and aquaculture sector in Myanmar through Dutch knowledge infrastructure (public and private)

Calorimetric study of geopolymer binders based on natural pozzolan

This paper investigates the kinetics of geopolymerisation in an inorganic polymeric binder based on a natural pozzolan. The heat released by the exothermic geopolymerisation reaction process is monitored under isothermal temperature conditions, maintained in a differential scanning calorimeter using a water circulation cell. Calorimetric data are obtained isothermally at 65, 75, and 85 °C with various Na2O/Al2O3 and SiO2/Na2O molar ratios and in the presence and absence of small amounts of calcium aluminate cement (used as an efflorescence control admixture in these binder systems). The first stage of reaction, which is rapid and strongly exothermic, is shortened as the temperature increases. The total heat of reaction increases in the mixes containing calcium aluminate cement, but the apparent activation energy calculated using a pseudo-first-order reaction model is lower than without added calcium aluminate cement. At a constant overall SiO2/Na2O molar ratio, the apparent activation energy is decreased as the Na2O/Al2O3 molar ratio increases. Calcium aluminate cement, therefore, reduces the minimum energy required to initiate geopolymerisation reactions of this natural pozzolan and facilitates the progress of the reactions which lead to formation of a cementitious product