| 1. |
- Alijagic, Andi, 1992-, et al.
(författare)
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Particle Safety Assessment in Additive Manufacturing : From Exposure Risks to Advanced Toxicology Testing.
- 2022
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Ingår i: Frontiers in Toxicology. - : Frontiers Media S.A.. - 2673-3080. ; 4
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Forskningsöversikt (refereegranskat)abstract
- Additive manufacturing (AM) or industrial three-dimensional (3D) printing drives a new spectrum of design and production possibilities; pushing the boundaries both in the application by production of sophisticated products as well as the development of next-generation materials. AM technologies apply a diversity of feedstocks, including plastic, metallic, and ceramic particle powders with distinct size, shape, and surface chemistry. In addition, powders are often reused, which may change the particles' physicochemical properties and by that alter their toxic potential. The AM production technology commonly relies on a laser or electron beam to selectively melt or sinter particle powders. Large energy input on feedstock powders generates several byproducts, including varying amounts of virgin microparticles, nanoparticles, spatter, and volatile chemicals that are emitted in the working environment; throughout the production and processing phases. The micro and nanoscale size may enable particles to interact with and to cross biological barriers, which could, in turn, give rise to unexpected adverse outcomes, including inflammation, oxidative stress, activation of signaling pathways, genotoxicity, and carcinogenicity. Another important aspect of AM-associated risks is emission/leakage of mono- and oligomers due to polymer breakdown and high temperature transformation of chemicals from polymeric particles, both during production, use, and in vivo, including in target cells. These chemicals are potential inducers of direct toxicity, genotoxicity, and endocrine disruption. Nevertheless, understanding whether AM particle powders and their byproducts may exert adverse effects in humans is largely lacking and urges comprehensive safety assessment across the entire AM lifecycle-spanning from virgin and reused to airborne particles. Therefore, this review will detail: 1) brief overview of the AM feedstock powders, impact of reuse on particle physicochemical properties, main exposure pathways and protective measures in AM industry, 2) role of particle biological identity and key toxicological endpoints in the particle safety assessment, and 3) next-generation toxicology approaches in nanosafety for safety assessment in AM. Altogether, the proposed testing approach will enable a deeper understanding of existing and emerging particle and chemical safety challenges and provide a strategy for the development of cutting-edge methodologies for hazard identification and risk assessment in the AM industry.
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| 2. |
- Brentel, Jonas, et al.
(författare)
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Single-wavelength 40 Gb/s soliton field transmission experiments over 400 km fibre without in-line control
- 1999
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Ingår i: OFC/IOOC 1999 - Optical Fiber Communication Conference and the International Conference on Integrated Optics and Optical Fiber Communication. - 155752582X ; 3, s. 121-124
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Konferensbidrag (refereegranskat)abstract
- We report single-wavelength 40-Gbit/s soliton transmission over 400-km installed fiber lines in Sweden. Both polarization-division multiplexed and parallel solitons were transmitted. The system performance is dominated by the polarization-mode dispersion.
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| 3. |
- Kolltveit, Erling, et al.
(författare)
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Single-wavelength 40 Gbit/s soliton field transmission experiment over 400 km of installed fibre
- 1999
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 35:1, s. 75-76
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Tidskriftsartikel (refereegranskat)abstract
- 40Gbit/s soliton transmission over 400km (57km amplifier spacing) of installed lines without in-line control has been achieved. The maximum transmission penalties for parallel polarised and polarisation division multiplexed soliton transmission were ∼4 and 1dB, respectively. The transmission distance is the longest ever reported for a field trial with a single wavelength bit rate > 20Gbit/s for any optical transmission format. The polarisation mode dispersion was numerically found to completely dominate the system performance.
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| 4. |
- Hedekvist, Per Olof E, 1967, et al.
(författare)
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Fiber four-wave mixing demultiplexing with inherent parametric amplification
- 1997
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 15:11, s. 2051-2058
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Tidskriftsartikel (refereegranskat)abstract
- We present an all-optical time-division demultiplexer with 22 dB conversion efficiency, using four-wave mixing (FWM) at 1550 nm in a single-mode dispersion-shifted fiber. Error-free demultiplexing of 20 Gb/s data to 10 Gb/s is obtained, with 1.4 dB power penalty at BER = 10-9. We also derive theoretical expressions for the conversion efficiency, the maximum bit rate that is possible to demux and the shape of the switching window. In particular we emphasize the importance of phase-matching in order to achieve a flat switching window. Furthermore the pump must remain undepleted to avoid a detrimental reduction of the extinction ratio due to instantaneous parametric gain saturation.
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| 5. |
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| 6. |
- Björk, Magnus, 1977, et al.
(författare)
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Exposed Datapath for Efficient Computing
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We introduce FlexCore, which is the first exemplar of a processor based on the FlexSoC processor paradigm. TheFlexCore utilizes an exposed datapath for increased performance. Microbenchmarks yield a performance boost of a factor of two over a traditional five-stage pipeline with the same functional units as the FlexCore.We describe our approach to compiling for the FlexCore.A flexible interconnect allows the FlexCore datapath to bedynamically reconfigured as a consequence of code generation. Additionally, specialized functional units may be introduced and utilized within the same architecture and compilation framework. The exposed datapath requires a wide control word. The conducted evaluation of two micro benchmarks confirms that this increases the instruction bandwidth and memory footprint. This calls for an efficient instruction decoding as proposed in the FlexSoC paradigm.
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| 7. |
- Börjeson, Erik, 1984, et al.
(författare)
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Circuit Implementation of Pilot-Based Dynamic MIMO Equalization for Coupled-Core Fibers
- 2024
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Ingår i: Optical Fiber Communication Conference, OFC 2024. - 9781957171326
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Konferensbidrag (refereegranskat)abstract
- We explore ASIC implementation for pilot-based MIMO equalizers for coupled-core transmission, considering chip area scaling trends and performance impact of time-dependent drift. For a system with 28-GBd subcarriers, an equalizer for 8 × 8 is 5.3 times larger than for 2 × 2.
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| 8. |
- Ebenhag, Sven-Christian, 1976, et al.
(författare)
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Two-way coherent frequency transfer in a commercial DWDM communication network in Sweden
- 2015
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Ingår i: 2015 Joint Conference of the IEEE International Frequency Control Symposium and the European Frequency and Time Forum, FCS 2015 - Proceedings. - 1075-6787. - 9781479988662 ; , s. 276-279
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Konferensbidrag (refereegranskat)abstract
- An experimental fiber link is being established between SP Technical Research Institute of Sweden in Boras and Chalmers University of Gothenburg in Sweden. The one way fiber length is about 60 km and implemented in SUNET (Swedish University Network). The aim of the project is to evaluate the signal quality when sending a stable optical frequency utilizing a wavelength in a DWDM (Dense Wavelength Division Multiplexing) system fiber pair. The experiment uses a channel in the DWDM with the wavelength of 1542.14 nm. This wavelength is within the C band and is therefore compatible with common Erbium doped amplifiers in this network. Another aim of the system is to be ultra-stable which corresponds to a stability of 1×10-13 for τ = 1 s as well as providing the ability to distribute monitored ultra-stable frequency with a future traceability to UTC (SP) (National realization of Universal Time Coordinated within Sweden) to multiple users within the network. Measurements of an optical frequency transfer using a fiber-link based on unidirectional light signals in parallel fibers have shown promising results in a free-running setup and in a lab environment. The fractional frequency stability, analyzed as the Overlapping Allan deviation, is approximately 3×10-13 at τ = 10 s and almost 1×10-14 at 105 s.
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| 9. |
- Hedekvist, Per Olof E, 1967, et al.
(författare)
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Polarization dependence and efficiency in a fiber four-wave mixing phase conjugator with orthogonal pump waves
- 1996
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Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 8:6, s. 776-778
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Tidskriftsartikel (refereegranskat)abstract
- We study the influence of pump separation on polarization dependence and on conversion efficiency in a fiberbased optical phase-conjugator with two orthogonal pump waves at different wavelengths. The polarization dependence is found to be minimized when the pump wavelength separation is small. Furthermore, both theory and experiments show that the efficiency is maximized if the signal wavelength is located close to one of the pumps.
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| 10. |
- Zhang, Renyun, et al.
(författare)
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Soap-film coating : High-speed deposition of multilayer nanofilms
- 2013
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Ingår i: Scientific Reports. - Nature Publishing Group : Springer Science and Business Media LLC. - 2045-2322. ; 3, s. Art. no. 1477-
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Tidskriftsartikel (refereegranskat)abstract
- The coating of thin films is applied in numerous fields and many methods are employed for the deposition of these films. Some coating techniques may deposit films at high speed; for example, ordinary printing paper is coated with micrometre-thick layers of clay at a speed of tens of meters per second. However, to coat nanometre thin films at high speed, vacuum techniques are typically required, which increases the complexity of the process. Here, we report a simple wet chemical method for the high-speed coating of films with thicknesses at the nanometre level. This soap-film coating technique is based on forcing a substrate through a soap film that contains nanomaterials. Molecules and nanomaterials can be deposited at a thickness ranging from less than a monolayer to several layers at speeds up to meters per second. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology.
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