| 1. |
- Lazaridis, Iosif, et al.
(author)
-
Ancient human genomes suggest three ancestral populations for present-day Europeans
- 2014
-
In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 513:7518, s. 409-
-
Journal article (peer-reviewed)abstract
- We sequenced the genomes of a similar to 7,000-year-old farmer from Germany and eight similar to 8,000-year-old hunter-gatherers from Luxembourg and Sweden. We analysed these and other ancient genomes(1-4) with 2,345 contemporary humans to show that most present-day Europeans derive from at least three highly differentiated populations: west European hunter-gatherers, who contributed ancestry to all Europeans but not to Near Easterners; ancient north Eurasians related to Upper Palaeolithic Siberians(3), who contributed to both Europeans and Near Easterners; and early European farmers, who were mainly of Near Eastern origin but also harboured west European hunter-gatherer related ancestry. We model these populations' deep relationships and show that early European farmers had similar to 44% ancestry from a 'basal Eurasian' population that split before the diversification of other non-African lineages.
|
|
| 2. |
- Rem, Peter C., et al.
(author)
-
The investigation of separability of particles smaller than 5 mm by eddy-current separation technology - Part II: novel design concepts
- 2000
-
In: Magnetic and Electrical Separation. - : Hindawi Limited. - 1055-6915 .- 1029-0303 .- 1477-2876. ; 10:2, s. 85-105
-
Journal article (peer-reviewed)abstract
- Separability and separation mechanisms of small particles in modern rotating type eddy-current separators (ECSs) were discussed in Part I. In order to address problems associated with this design concept, a number of novel ECSs, each with a unique design, have been developed. Part II reports on investigation into the separability and separation principles for various materials smaller than 5 mm, including fine copper wires, in three new devices: the redesigned Delft vertical ECS (VECS), prototype TNO ECS and a laboratory wet ECS (WECS). It is found that TNO ECS and WECS are more practical tools for separation of small metal particles. In particular, WECS is able to recover approximately 80% of very fine copper wires, with 0.5 mm diameter and 2 mm length. Separation principles for WECS are discussed in greater detail than other design concepts in the present study. It appears that the fledgling WECS will be most promising in the future for processing small particles. Further, aluminum separation from the -10 mm fraction of electronic scrap has been carried out using TNO ECS. It transpires that both the recovery and the grade of the aluminum concentrate are superior to those obtained with the rotary belted-drum ECS of any type.
|
|
| 3. |
- Zhang, Shunli, et al.
(author)
-
End-of-life electric and electronic equipment management towards the 21st century
- 2000
-
In: Waste Management & Research. - : Wiley. - 0734-242X .- 1096-3669 .- 1399-3070. ; 18:1, s. 73-85
-
Journal article (peer-reviewed)abstract
- With the rapid growth of the electronics industry and an evergrowing environmental awareness worldwide, an environmentally sound and economically viable management system for endoflife (EOL) electric and electronic equipment (EEE) is of great importance for sustainable development. Traditional recycling and processing of EOL electronics directed towards the recovery of copper and precious metals, will be faced with many challenges in the future. It has been recognized by the EOL EEE recycling industry that a new strategy for EOL EEE must be developed. In this paper, current status and future trends in EOL EEE management are presented. Selective dismantling of valuable and hazardous components is evaluated in terms of a graderecovery (GR) concept. It is concluded that selective dismantling and mechanical processing must be coordinated in such a way as to produce suitable materials for subsequent handling at the lowest cost. Furthermore, new developments in mechanical and thermal processing of EOL EEE are also discussed, which involve water table and eddy current separation techniques and reduction of dioxins and furans during combustion of the plastics containing halogenated flame retardants. In addition, the challenges and perspectives associated with EOL management of plastics and cathode ray tubes (CRTs) encountered in EOL EEE are highlighted in this paper. It is predicted that EEE, being designed for recycling in the 21st century, will be processed and recycled economically and ecologically on becoming obsolete.
|
|
| 4. |
- Zhang, Shunli, et al.
(author)
-
Investigation of separability of particles smaller than 5 mm by eddy current separation technology. Part I : Rotating type eddy current separators
- 1999
-
In: Magnetic and Electrical Separation. - : Hindawi Limited. - 1055-6915 .- 1029-0303 .- 1477-2876. ; 9:4, s. 233-251
-
Journal article (peer-reviewed)abstract
- Owing to the growing emergence of the end-of-life electrical and electronic products with complex material structures and an ever-diminishing particle size of the valuable metals involved, development of eddy current separators (ECS) has been targeting selective separation of small non-ferrous metal particles smaller than 5 mm. Separability of various materials smaller than 5 mm, including fine copper wires, has been investigated using ECS with various design concepts. The present research work is divided into two parts, with Part I focusing on the rotating type ECS which are today common in practice, and with Part II dedicated to the ECS with novel concepts such as wet ECS technology. In Part I, three rotating belted-drum ECS were employed, which are manufactured by Bakker Magnetics, the Netherlands, Huron Valley Steel Co., US, and Eriez Magnetics, UK respectively. It is found that the belted-drum ECS are effective for separating materials below 5 mm if the magnetic drum rotates in opposite direction to the conveyor belt. The separation principle, particularly the 'backward phenomenon' of the rotating type ECS for small particles has been unravelled in the present study. Moreover, separation of Al from the 0-10 mm fraction of electronic scrap has been conducted. The results obtained demonstrate that the belted-drum ECS with appropriate design may be applicable for separation of small aluminum particles from electronic scrap.
|
|
| 5. |
- Zhang, Shunli, et al.
(author)
-
Particle trajectory simulation of two-drum eddy current separators
- 1999
-
In: Resources, Conservation and Recycling. - 0921-3449 .- 1879-0658. ; 26:2, s. 71-90
-
Journal article (peer-reviewed)abstract
- Particle trajectories of the newly-developed two-drum eddy current separators are simulated by the ECSIM software package. The simulation results have been substantiated by measuring the horizontal displacements of the particles to be investigated under the same conditions. It is shown that the simulation results are in good agreement with the experimental ones. Further, on the basis of the simulation results obtained, the potential for improving the design of two-drum eddy current separators is discussed. It appears that the performance of two-drum eddy current separators, when processing small particles, may be enhanced by strengthening the magnetic field intensity and simultaneously increasing the maximum drum speed.
|
|
