| 1. |
- Bickham, S., et al.
(författare)
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Low cutoff G.657-compatible fiber for data center interconnects operating in the 1064 and 1310 nm windows
- 2020
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 11286
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Konferensbidrag (refereegranskat)abstract
- Optical interconnects in data centers have traditionally used 850 nm GaAs-based vertical-cavity surface-emitting lasers (VCSELs) in combination with multimode fiber, having a reach up to 100 m in length. Longer links typically use standard single-mode fiber in conjunction with either InP-based edge-emitting lasers or silicon photonic transmitters operating in the 1310 nm or 1550 nm window. Single-mode GaAs-based VCSELs operating at 1064 nm offer another path for achieving longer system reach. Potential advantages of these VCSELs include better power efficiency, modulation speeds reaching 50 Gbps and large-scale fabrication volumes. The longer wavelength is also beneficial due to the lower attenuation and chromatic dispersion of optical fibers at that wavelength. However, one practical issue for single-mode transmission is that the G.657 standard for single-mode fiber requires that the 22-meter cable cutoff wavelength be less than 1260 nm, and these fibers are typically few-moded at 1064 nm. The large differences between the group velocities of the LP01 and LP11 modes can lead to degradation of the system performance due to multi-path interference if the higher order modes are present. To resolve this quandary, we have designed and validated the performance of a new optical fiber which is single-moded at wavelengths less than 1064 nm, but also has G.657-compliant mode field diameter and dispersion characteristics that enable it to be used in the 1310 nm window.
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| 2. |
- Voitsekhovitch, I., et al.
(författare)
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Recent EUROfusion Achievements in Support of Computationally Demanding Multiscale Fusion Physics Simulations and Integrated Modeling
- 2018
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Ingår i: Fusion Science and Technology. - : Informa UK Limited. - 1536-1055 .- 1943-7641. ; 74:3, s. 186-197
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Tidskriftsartikel (refereegranskat)abstract
- © 2018, © 2018 The Authors. Published with license by Taylor & Francis Group, LLC. Integrated modeling (IM) of present experiments and future tokamak reactors requires the provision of computational resources and numerical tools capable of simulating multiscale spatial phenomena as well as fast transient events and relatively slow plasma evolution within a reasonably short computational time. Recent progress in the implementation of the new computational resources for fusion applications in Europe based on modern supercomputer technologies (supercomputer MARCONI-FUSION), in the optimization and speedup of the EU fusion-related first-principle codes, and in the development of a basis for physics codes/modules integration into a centrally maintained suite of IM tools achieved within the EUROfusion Consortium is presented. Physics phenomena that can now be reasonably modelled in various areas (core turbulence and magnetic reconnection, edge and scrape-off layer physics, radio-frequency heating and current drive, magnetohydrodynamic model, reflectometry simulations) following successful code optimizations and parallelization are briefly described. Development activities in support to IM are summarized. They include support to (1) the local deployment of the IM infrastructure and access to experimental data at various host sites, (2) the management of releases for sophisticated IM workflows involving a large number of components, and (3) the performance optimization of complex IM workflows.
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| 3. |
- Dehlin, S., et al.
(författare)
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Practical application of a newly developed automated building energy-analysis software module prototype
- 2012
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Ingår i: eWork and eBusiness in Architecture, Engineering and Construction. - Boca Raton : CRC Press, Taylor & Francis Group. - 9780415621281 ; , s. 45-49
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Konferensbidrag (refereegranskat)abstract
- One key challenge when it comes to developing industrial building concepts for the housing industry is improving the energy performance of buildings, while at the same time ensuring that the end product remains affordable and attractive to customers. This paper summarises the findings from the application of a newly developed prototype for an automated energy-analysis software module in a real-life project.The prototype is used for the energy analysis of the low-energy, multi-family residential P303 concept developed by NCC Construction Sverige AB - a leading construction and development company in the Nordic region. A building concept is based on continuity and repetitions of most of the building components. Most of its characteristics are known and defined beforehand and only a few parameters vary due to the adaptation of the concept, for example, the configuration or site location. In energy performance calculations, the proposed energy-analysis software module prototype processes the known parameters as constants and only varies the unknown parameters. The energy calculations are then carried out by the calculation kernel from the dynamic building simulation software module, VIP Energy, and the result is exported to an Excel spreadsheet where it is presented in a table. This makes it possible, in a practical manner, to execute a larger number of performance analyses in a shorter time, investigating different design alternatives and configurations and thereby facilitating optimisation towards the best possible design solution. The case study presented in this paper simulated energy losses through the building envelope of a real P303 building. The parameters that were varied are the location and orientation of the building and various energy characteristics of windows/glazing.
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| 4. |
- Weaver, Jamie L., et al.
(författare)
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Pre‐Viking Swedish Hillfort Glass : A Prospective Long‐Term Alteration Analogue for Vitrified Nuclear Waste
- 2018
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Ingår i: The International Journal of Applied Glass Science (IJAGS). - : John Wiley & Sons. - 2041-1294 .- 2041-1286. ; 9:4, s. 540-554
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Tidskriftsartikel (refereegranskat)abstract
- Models for long‐term glass alteration are required to satisfy performance predictions of vitrified nuclear waste in various disposal scenarios. Durability parameters are usually extracted from short‐term laboratory tests, and sometimes checked with long‐term natural experiments on glasses, termed analogues. In this paper, a unique potential ancient glass analogue from Sweden is discussed. The hillfort glass found at Broborg represents a unique case study as a vitrified waste glass analogue to compare to Low Activity Waste glass to be emplaced in near surface conditions at Hanford (Washington State). Glasses at Broborg have similar and dissimilar compositions to LAW glass, allowing the testing of long‐term alteration of different glass chemistries. Additionally, the environmental history of the site is reasonably well documented. Initial investigations on previously collected samples established methodologies for handling and characterizing these artifacts by laboratory methods while preserving their alteration layers and cultural context. Evidence of possible biologically influenced glass alteration, and differential alteration in the two types of glass found at the Broborg site is presented.
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