In the western Netherlands Neolithic axes are hardly ever found in a complete state. Flint is scarce in this area and when these axes were exhausted, or when they broke during use, they were often... Show moreIn the western Netherlands Neolithic axes are hardly ever found in a complete state. Flint is scarce in this area and when these axes were exhausted, or when they broke during use, they were often re-used as flake cores. Vlaardingen Culture (3400–2500 BC) sites often yield large quantities of flakes and retouched tools made on polished axe fragments. Using an experimental approach, we tried to better understand the importance of recycling of these objects. For the experiments we reconstructed four so-called Buren axes. The experiments provided insights into the usefulness of broken axes as flake cores. It was also demonstrated that flakes struck from axes generally do not have a remnant of a polished surface, indicating that the importance of broken axes as flake cores has so far been underestimated. Furthermore, it was concluded that micro-debitage can successfully be studied to identify areas where broken axes were flaked. Show less
Zhang, C.; Hu, M.; Meide, M. van der; Di Maio, F.; Yang, X.; Gao, X.; ... ; Li, C. 2023
Raw Materials are crucial in the development, production, and improvement of modern-day technology. Reliable access to critical, scarce, and valuable materials used in electronics is becoming a... Show moreRaw Materials are crucial in the development, production, and improvement of modern-day technology. Reliable access to critical, scarce, and valuable materials used in electronics is becoming a worldwide concern. Therefore, the quantification of material recovery from the urban mine is currently pursued worldwide. Commonly, data on (Waste) Electrical and Electronic Equipment is scattered, not harmo-nized, and uses different types of classifications and terminology. This provides a big challenge of a structured mapping of secondary raw materials in the urban mine. To address these issues, a state-of -the-art methodology has been developed and is presented by analyzing and tracking printed circuit boards in different key Electrical and Electronic Equipment over time. A total of 4051 composition data records where analyzed to extract the concentration of 19 elements in printed circuit boards between 1990 until 2020. The methodology harmonizes urban mine data, provides structured information that can be used to analyze and monitor the impact of product trends on their components and concentration of the elements in electronics. The resulting database and harmonization protocols are made freely available at the urban mine platform. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
