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| 2. |
- Swarén, Mikael, et al.
(författare)
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Testing method for objective evaluation of cross-country ski poles
- 2013
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Ingår i: Sports Engineering. - : Springer Science and Business Media LLC. - 1369-7072 .- 1460-2687. ; 16:4, s. 255-264
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to develop an objective classification method for cross-country ski poles. A test device was designed to expose different pole models to maximal loading and impact tests. A load cell measured the axial forces in the pole shafts, and a laser distance meter measured shaft deflection when a load was applied via the wrist strap. In the loading tests, each shaft reached a plateau where no more force could be transferred. This maximal force transfer (MFT) value was a characteristic measure for flexural rigidity and thereby also strength. The developed test method enables a loading that is more similar to real-life skiing than a standard three-point bending test. Results show that the introduction of shaft indices for buckling strength is beneficial for comparison purposes. The MFT is a relevant parameter used in the characterization of poles.
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| 3. |
- Andreasson, Jakob, et al.
(författare)
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Franck-Condon higher order lattice excitations in the LaFe1-xCrxO3 (x=0, 0.1, 0.5, 0.9, 1.0) perovskites due to Fe-Cr charge transfer effects
- 2007
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 75
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Tidskriftsartikel (refereegranskat)abstract
- First and higher order lattice excitations in the B-site disordered perovskites LaFe1-xCrxO3 (x=0, 0.1, 0.5, 0.9, and 1) and La0.835Sr0.165Fe0.5Cr0.5O3-delta are investigated using temperature dependent and polarized inelastic light scattering [lambda=515 nm (2.41 eV) and 676 nm (1.83 eV)] on oriented crystallites. A peak at approximately 2.4 eV in the imaginary part of the dielectric function of LaFe0.5Cr0.5O3 is assigned to a charge transfer from Fe3+ (d(5)) to Cr3+ (d(3)) ions, coupled with the appearance of an intense A(g)-like mode at approximately 700 cm(-1) in the Raman data. This excitation is identified as a symmetric oxygen breathing mode activated by the Fe-Cr charge transfer through an orbital coupling mechanism. Higher order scattering (up to seventh order) of the intrinsic Raman active symmetric breathing mode is also explained by an orbital-mediated electron-phonon coupling, similar to the Franck-Condon effect observed in the Jahn-Teller active-perovskite-structured manganite LaMaO(3). These results show that the Franck-Condon mechanism is a more common mechanism for resonant higher order scattering in solids than previously believed and propose the LaFe1-xCrxO3 system as a model system for electron-phonon coupling and higher order Raman scattering in solids.
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| 5. |
- Eriksson, Bengt Erik, et al.
(författare)
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Att studera eliter
- 2018
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Ingår i: Eliter i Sverige. - Lund : Studentlitteratur AB. - 9789144116365 ; , s. 11-26
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Eriksson, Oskar, et al.
(författare)
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On Hybrid ARQ Adaptive Forward Error Correction in Wireless Sensor Networks
- 2011
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Ingår i: IECON 2011. - : IEEE conference proceedings. - 9781612849720 ; , s. 3004-3010
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Konferensbidrag (refereegranskat)abstract
- The use of wireless technology in the process industry is becoming increasingly important to obtain fast deployment at low cost. However, poor channel quality often leads to retransmissions, which are governed by Automatic Repeat Request (ARQ) schemes. While ARQ is a simple and useful tool to alleviate packet errors, it has considerable disadvantages: retransmissions lead to an increase in energy expenditure and latency. The use of Forward Error Correction (FEC) however offers several advantages. We consider a Hybrid-ARQ-Adaptive-FEC scheme (HAF) based on BCH codes and Channel State Information. This scheme is evaluated on AWGN and fading channels. It is shown that HAF offers significantly improved performance both in terms of energy efficiency and latency, as compared to ARQ.
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| 7. |
- Gidlund, Mikael, et al.
(författare)
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Wireless Communication between two temporarily connected devices
- 2011
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Patent (populärvet., debatt m.m.)abstract
- A system for setting up a wireless connection between two temporarily connected devices (10, 12) comprises a device interconnector (14) having a first end (19) provided with a first wireless communication identifier and a second end (21) provided with a second wireless communication identifier, a first device (10) having a first interconnector mating unit (23), a first wireless communication unit (28) and a first reading unit (26) and a second device (12) having a second interconnector mating unit (31), a second wireless communication unit (34) and a second reading unit (32). The wireless communication units of each device is configured to receive an identifier being read by the corresponding reading unit as the device interconnector is attached to the corresponding mating unit and the wireless communication unit is configured to employ this identifier in setting up, together with the other wireless communication unit, a wireless connection between the two devices.
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| 8. |
- Jonas, Örtegren, et al.
(författare)
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Cone motion viscosity and optical second harmonic generation of ferroelectric liquid crystalline dendrimers
- 2001
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Ingår i: Liquid crystals (Print). - : Informa UK Limited. - 0267-8292 .- 1366-5855. ; 28:6, s. 861-868
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Tidskriftsartikel (refereegranskat)abstract
- We report second harmonic generation in a ferroelectric liquid crystalline trimer and ferroelectric liquid crystalline dendrimers of first, second and third generation. Thin cells were filled with the compounds by capillary forces at elevated temperature, and cooled from the surface stabilized ferroelectric state to below the glass transition temperature, while kept in an electric field. The cone motion viscosity and the threshold electric field for unwinding of the helix axis of the chiral tilted smectic mesophases were studied separately at elevated temperature, and these data were used to optimize the preparation of the films. The measured response time was between 0.3 and 3 ms, which corresponds to a cone motion viscosity between 0.5 and 50 Pa s. Second harmonic generation was studied both at elevated temperature with an electric field and at room temperature with and without electric field. The first generation dendrimer exhibited a strong increase in the second order non-linear optical response with time at room temperature. The d(23)-coefficient of this dendrimer was approximately four times larger than for the other macromolecules and was 0.045 pm V-1. The relatively large d-coefficient of the first generation dendrimer is ascribed to crystallization, which improved the orientation of the molecular dipoles.
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