The reaction of the alkyl complexes Cp*2LnCH(SiMe 3)2 (Ln = Y 1-Y, Ce 1-Ce, La 1-La; Cp* = η5-C5Me5) and Me2Si(η 5-C5Me4)2LnCH(SiMe3) 2 (Ln = Ce 5-Ce) with 1-methylalk-2-ynes CH3C≡CR (R = Me 3a, Et 3b, nPr 3c, tBu 3d, SiMe3 3e, Ph 3f, C6H4Me-2 3g, C6H3Me 2-2,6 3h, C6H3iPr2-2,6 3i, C6F5 3j) affords the corresponding η3-propargyl/allenyl complexes Cp*2LnCH 2CCR (4a-j-Ln) and Me2Si(η5-C 5Me4)2CeCH2CCR (6a-j-Ce) via propargylic metalation. The hydride complexes [Cp*2Ln(μ-H)] 2 (Ln = Y 2-Y, Ce 2-Ce, La 2-La) react rapidly with 3 to produce mixtures of insertion and propargylic metalation products, and the relative rate of these processes depends on the metal and alkyne substituent. Selected η3-propargy/allenyl complexes Cp*2YCH 2CCR (R = Me 4a-Y, Ph 4f-Y), Cp*2CeCH2CCR (R = Me 4a-Ce, Ph 4f-Ce), Cp*2CeCH(Me)CCEt (9b-Ce), Cp*2LaCH2CCR (R = Ph 4f-La, C6H 3Me2-2,6 4h-La) are obtained on a preparative scale and characterized by NMR spectroscopy, IR spectroscopy, and cryoscopy. Compounds 4f-Y and 4f-La are also characterized by single-crystal X-ray diffraction. The reactions of the η3-propargyl/allenyl complexes with Brønsted acids, such as alcohols and acetylenes, afford the corresponding substituted allenes (RCH=C=CH2) and 1-methylalk-2-ynes (CH 3C≡CR) as organic products. The reactions of 4f-Y and 4f-La with Lewis bases, such as pyridine and THF, yield die corresponding base adducts. The adduct 4f-La · py is characterized by single-crystal X-ray diffraction, revealing an η3-coordinated propargyl/allenyl ligand. © 2008 American Chemical Society.
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Het boek ‘3D Printing with biomaterials’ introduceert een manier om een duurzame en circulaire economie te realiseren; 3D printen gecombineerd met het gebruik van biomaterialen.
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In the housing market enormous challenges exist for the retrofitting of existing housing in combination with the ambition to realize new environmentally friendly and affordable dwellings. Bio-based building materials offer the possibility to use renewable resources in building and construction. The efficient use of bio-based building materials is desirable due to several potential advantages related to environmental and economic aspects e.g. CO2 fixation and additional value. The potential biodegradability of biomaterials however demands also in-novative solutions to avoid e.g. the use of environmental harmful substances. It is essential to use balanced technological solutions, which consider aspects like service life or technical per-formance as well as environmental aspects. Circular economy and biodiversity also play an im-portant role in these concepts and potential production chains. Other questions arise considering the interaction with other large biomass users e.g. food production. What will be the impact if we use more bio-based building materials with regard to biodiversity and resource availability? Does this create opportunities or risks for the increasing use of bio-based building materials or does intelligent use of biomass in building materials offer the possibility to apply still unused (bio) resources and use them as a carbon sink? Potential routes of intelligent usage of biomass as well as potential risks and disadvantages are highlighted and discussed in relation to resource efficiency and decoupling concept(s).
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The 3D Additivist Cookbook, devised and edited by Morehshin Allahyari & Daniel Rourke, is a free compendium of imaginative, provocative works from over 100 world-leading artists, activists and theorists. The 3D Additivist Cookbook contains .obj and .stl files for the 3D printer, as well as critical and fictional texts, templates, recipes, (im)practical designs and methodologies for living in this most contradictory of times.
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Martien Visser roept de politiek en de rechterlijke macht op te stoppen met het nemen van deelbesluiten en strategisch en integraal te gaan denken en doen.
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The primary purpose of this chapter is to provide insights into the body of scholarly literature on the question of magazines and sustainability—in both production and editorial content. This chapter will also discuss production-side issues for business decision-making and policy, as well as editorial-side, within publishing organizations. Drawing on recent literature on the environmental impact of both information and communication technologies, with the Internet on the one hand and digitalization of media on the other, this chapter will identify a number of important effects of new magazine production and issues of sustainability with a primary focus on reviewing the emerging body of scholarly literature that relates to the question. The sociological and anthropological literature will be examined and Cradle to Cradle (C2C) theory will be introduced, in order to lead to the discussion of research arising from these perspectives as well as methods being used to explore these questions. This is an Accepted Manuscript of a book chapter published by Routledge/CRC Press in "The Routledge Handbook of Magazine Research: The Future of the Magazine Form" in June 2015 available online: https://www.routledgehandbooks.com/doi/10.4324/9781315722283 LinkedIn: https://www.linkedin.com/in/helenkopnina/
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The project BioP2M came to a close in June 2019 after a consortium of stakeholders in the field of energy transition worked together to research the diverse role of Methane. In this report the results are presented and future plans are discussed.
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English translation of the first chapter of "Negen plagen tegelijk : hoe overleven we de toekomst?" (vert.: Marije Fresacher)
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Recent years have seen a global rise in the failure of tailings dams. Studies investigating the causes of slope failure often recognise high intensity rainfall events to significantly contribute to liquefaction, erosion and overtopping. This study aims to investigate the influence of alternative physical and geohydrological processes that, under tension saturation conditions, contribute to slope instability in tailings dams. It has been suggested that the generation of transient pressure wave mechanisms by high intensity rainfall events, surface ponding and wetting front advancement result in the formation of an induced pressure head that triggers the mobilization of pre-event water. In order to quantify these physical processes, this study included the analysis of rapid transmission conditions in a silica fines mix, with similar physical and hydraulic characteristics as platinum tailings. A tall leak-proof soil column, containing the soil sample compacted to in-situ dry bulk density, was fitted with seven observation ports. Each port consisted of a pore air pressure probe, a mini tensiometer and a time domain reflectometry probe. After set-up and initial stabilisation, three separate artificial high intensity rainfall events were applied to the surface. Monitoring of hydraulic state variables was recorded at thirty second intervals by automatic logging, thereby enabling the analysis of measured outcomes. Observations showed instant spikes in pore air pressure ahead of the wetting front, as well as a number of delayed responses. The interpretation of lab results led to the conclusion that pressure diffusion mechanisms throughout the porous medium, could result in the rapid release and mobilisation of previously stagnant antecedent moisture, thereby enabling phreatic levels to rising rapidly and in excess to the amount of surface infiltration. Also, since an increase in pore water pressure is likely to cause a reduction in shear strength, it is suggested that these physical and geohydrological processes could have an adverse impact on the stability of tailings dams.
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