| 61. |
- Dencker, Kerstin, 1972-, et al.
(författare)
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Proactive Assembly Systems – realizing the potential of human collaboration with automation
- 2009
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Ingår i: Annual Reviews in Control. - : Elsevier. - 1367-5788 .- 1872-9088. ; 33:2, s. 230-237
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Forskningsöversikt (refereegranskat)abstract
- Manufacturing competitiveness frequently relies on company ability to rapidly reconfigure their assembly systems. This paper introduces assembly system proactivity, a concept based on interrelated levels of automation, human competence, and information handling. Increased and structured human involvement contributes to increased system ability to proactively address predicted and unpredicted events. Correct involvement of human operators will utilize the combined potential of human and technical capabilities, providing cost-efficient assembly system solutions. The ProAct project is developing proactive assembly system models and evaluates proactive, feature-based solutions. Focus is on realising the potential of cost-efficient and semi-automated systems with relevant human involvement, i.e. highly skilled operators who add flexibility and functionality.
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| 62. |
- Deppert, Knut, et al.
(författare)
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Epitaxielle Kristallnadeln und -bäume
- 2005
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Ingår i: Book of abstracts: DGKK-Jahrestagung, Köln, Germany (2005).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 63. |
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| 64. |
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| 65. |
- Dick Thelander, Kimberly, et al.
(författare)
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Failure of the vapor-liquid-solid mechanism in Au-assisted MOVPE growth of InAs nanowires
- 2005
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 5:4, s. 761-764
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Tidskriftsartikel (refereegranskat)abstract
- We report the temperature dependence of the Au-assisted growth of InAs nanowires in MOVPE. Extensive studies of the growth of such nanowires have attributed growth to the so-called vapor-liquid-solid (VLS) mechanism, with a liquid Au-In alloy particle. We assert here that growth is instead assisted by a solid particle and does not occur at all when the particle is a liquid. Thus the temperature range of InAs nanowire growth is limited by the melting of the Au-In alloy. Comparison with growth of InAs nanowires in the same system assisted by a layer of SiOx is used to support this conclusion.
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| 66. |
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| 67. |
- Dick Thelander, Kimberly, et al.
(författare)
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Growth of GaP nanotree structures by sequential seeding of 1D nanowires
- 2004
-
Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 272:1-4, s. 131-137
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Tidskriftsartikel (refereegranskat)abstract
- Complex nanostructures are becoming increasingly important for the development of nanoscale devices and functional nanomaterials. Precise control of size and morphology of these structures is critical to their fabrication and exploitation. We have developed a method for stepwise growth of tree-like nanostructures via the vapour liquid-solid (VLS) growth mode, demonstrated for III-V semiconductor materials. This method uses the initial seeding of nanowires by catalytic aerosol nanoparticles to form the trunk, followed by sequential seeding of branching structures. Here we present a detailed study of the growth of these complex structures using Gap. Diameter of each level of nanowires is directly determined by seed particle diameters, and number of branches is determined by seed particle density. Growth rate is shown to increase with temperature to a maximum corresponding to the temperature of complete decomposition of the Group-III precursor material, and subsequently decrease due to competition with bulk growth. Growth rate also depends on flow of the Group-III precursor, but not on the Group-V precursor. Finally, there is a relationship between the number of branches and their growth rate, suggesting that material diffusion plays a role in nanowire branch growth. (C) 2004 Elsevier B.V. All rights reserved.
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| 68. |
- Dick Thelander, Kimberly, et al.
(författare)
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Self-assembled InAs nanowire networks
- 2005
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Ingår i: Book of extended abstracts: MRS Fall Meet, Boston, Ma, USA, 2005.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 69. |
- Dick Thelander, Kimberly, et al.
(författare)
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Synthesis of branched 'nanotrees' by controlled seeding of multiple branching events
- 2004
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Ingår i: Nature Materials. - : Springer Science and Business Media LLC. - 1476-4660 .- 1476-1122. ; 3:6, s. 380-384
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Tidskriftsartikel (refereegranskat)abstract
- The formation of nanostructures with controlled size and morphology has been the focus of intensive research in recent years(1-10). Such nanostructures are important in the development of nanoscale devices and in the exploitation of the properties of nanomaterials(9). Here we show how tree-like nanostructures ('nanotrees') can be formed in a highly controlled way. The process involves the self-assembled growth of semiconductor nanowires via the vapour-liquid-solid(11) growth mode. This bottom-up method uses initial seeding by catalytic nanoparticles(12) to form the trunk, followed by the sequential seeding of branching structures. Each level of branching is controlled in terms of branch length, diameter and number, as well as chemical composition. We show, by high-resolution transmission electron microscopy, that the branching mechanism gives continuous crystalline (monolithic) structures throughout the extended and complex tree-like structures. The controlled seeding method that we report here has potential as a generic means of forming complex branching structures, and may also offer opportunities for applications, such as the mimicking of photosynthesis in nanotrees.
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| 70. |
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