| 1. |
- Ahlberg, Erik, et al.
(författare)
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"Vi klimatforskare stödjer Greta och skolungdomarna"
- 2019
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Ingår i: Dagens nyheter (DN debatt). - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN DEBATT 15/3. Sedan industrialiseringens början har vi använt omkring fyra femtedelar av den mängd fossilt kol som får förbrännas för att vi ska klara Parisavtalet. Vi har bara en femtedel kvar och det är bråttom att kraftigt reducera utsläppen. Det har Greta Thunberg och de strejkande ungdomarna förstått. Därför stödjer vi deras krav, skriver 270 klimatforskare.
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| 2. |
- Molin, Nils-Erik, et al.
(författare)
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Eigenmodes of av violin body
- 1990
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Ingår i: Proceedings / Nordic Acoustical Meeting 90 - NAM 90. - Luleå : CENTEK. - 9186998390 ; , s. 421-428
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Konferensbidrag (refereegranskat)
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| 3. |
- Molin, Nils-Erik, et al.
(författare)
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Parameters of violin plates and their influence on the plate modes
- 1988
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 83:1, s. 281-291
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Tidskriftsartikel (refereegranskat)abstract
- Noncontact measuring methods and numerical calculations are used in a study of musical instruments. First, a simple method to determine the material parameters of a blank to a violin plate is presented. Eigenmodes of rectangular free-free violin wooden blanks are determined using optical nondestructive methods, Chladni patterns, or tapping. Assuming orthotropic material, the first three eigenmodes for such a blank are calculated using the finite element method (FEM). It is shown that the frequency of each eigenmode depends on separate elastic parameters. With this one variable dependence, it is a simple task to determine effective material parameters for quarter-cut standard wooden blanks when the frequencies and mass are known. Second, the violin maker's problem with the influence of material and geometrical parameters on the vibration modes is investigated. Numerical models and corresponding real violin plates are made from the spruce and the maple blanks. Good agreement between calculated and experimentally obtained plate modes is found. Calculations with a 10% variation in each parameter are thereafter used to give information about the influence of overall plate thickness variation, of local thickness variations, of changes in arch-height, and of material parameters. Third, boundary conditions for the plates when glued to the ribs are examined in a pilot experiment.
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| 4. |
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| 7. |
- Jansson, Kristofer, et al.
(författare)
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Amplifier Design Using Vertical InAs Nanowire MOSFETs
- 2016
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Ingår i: IEEE Transactions on Electron Devices. - 0018-9383. ; 63:6, s. 2353-2359
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, an amplifier design using ballistic vertical InAs nanowire (NW) transistors is investigated, focusing on a basic common-source amplifier. The maximum power gain at 90 GHz is evaluated for different NW transistor architectures together with the power dissipation. The linearity of the amplifier is evaluated by estimating the IIP3 and 1-dB compression points. Furthermore, the impact of the parasitic capacitances and resistances is quantified and it is demonstrated that the gain may be increased by a cascode design. It is concluded that a power gain exceeding 20 dB at 90 GHz may be achieved by a common-source amplifier based on an InAs NW transistor architecture. A power consumption below 1 mW is possible, while still maintaining a high power gain. Furthermore, IIP3 exceeding 10 dBm is predicted. The combination of these qualities makes the NW transistor architecture an attractive prospect for low-power amplifiers at millimeter wave frequencies.
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| 8. |
- Jansson, Kristofer, et al.
(författare)
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Ballistic modeling of InAs nanowire transistors
- 2016
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Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101. ; 115, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the intrinsic performance of InAs nanowire transistors is evaluated in the ballistic limit. A self-consistent Schrodinger-Poisson solver is utilized in the cylindrical geometry, while accounting for conduction band non-parabolicity. The transistor characteristics are derived from simulations of ballistic transport within the nanowire. Using this approach, the performance is calculated for a continuous range of nanowire diameters and the transport properties are mapped. A transconductance exceeding 4 S/mm is predicted at a gate overdrive of 0.5 V and it is shown that the performance is improved with scaling. Furthermore, the influence from including self-consistency and non-parabolicity in the band structure simulations is quantified. It is demonstrated that the effective mass approximation underestimates the transistor performance due to the highly non-parabolic conduction band in InAs. Neglecting self-consistency severely overestimates the device performance, especially for thick nanowires. The error introduced by both of these approximations gets increasingly worse under high bias conditions. (C) 2015 Elsevier Ltd. All rights reserved.
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| 9. |
- Jansson, Kristofer, et al.
(författare)
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Intrinsic Performance of InAs Nanowire Capacitors
- 2014
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Ingår i: IEEE Transactions on Electron Devices. - 0018-9383. ; 61:2, s. 452-459
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Tidskriftsartikel (refereegranskat)abstract
- The intrinsic properties of vertical InAs nanowire (NW) capacitors are investigated. The band structure is simulated using a Schrödinger-Poisson solver, taking the conduction band nonparabolicity into account. This is combined with a distributed RC model to simulate the current-voltage characteristics. It is found that the influence from the nonparabolicity is substantial for devices with a small nanowire diameter, resulting in an increased carrier concentration, a shift in the threshold voltage, and a higher intrinsic capacitance. These NW capacitors may be a suitable alternative in high frequency applications approaching 100 GHz, while maintaining a quality factor above 100.
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| 10. |
- Jansson, Kristofer, et al.
(författare)
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Performance Evaluation of III–V Nanowire Transistors
- 2012
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Ingår i: IEEE Transactions on Electron Devices. - 0018-9383. ; 59:9, s. 2375-2382
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Tidskriftsartikel (refereegranskat)abstract
- III–V nanowire (NW) transistors are an emerging technology with the prospect of high performance and low power dissipation. Performance evaluations of these devices, however, have focused mostly on the intrinsic properties of the NW, excluding any parasitic elements. In this paper, a III–V NW transistor architecture is investigated, based on a NW array with a realistic footprint. Based on scaling rules for the structural parameters, 3-D representations of the transistor are generated, and the parasitic capacitances are calculated. A complete optimization of the structure is performed based on the RF performance metrics fT and fmax, employing intrinsic transistor data combined with calculated parasitic capacitances and resistances. The result is a roadmap of optimized transistor structures for a set of technology nodes, with gate lengths down to the 10-nm-length scale. For each technology node, the performance is predicted, promising operation in the terahertz regime. The resulting roadmap has implications as a reference both for benchmarking and for device fabrication.
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