| 1. |
- Khosropanah, Pourya, 1971, et al.
(författare)
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Analysis of NbN Hot Electron Bolometer Receiver Noise Temperatures Above 2 THz With a Quantum Noise Model
- 2009
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Ingår i: IEEE Transactions on Applied Superconductivity. - 1558-2515 .- 1051-8223. ; 19:3, s. 274-277
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Tidskriftsartikel (refereegranskat)abstract
- This paper summarizes our receiver noise temperature data of NbN HEB mixers obtained at a number of local oscillator frequencies between 1.9 to 4.3 THz in order to verify the role of quantum noise. The experimental data show that the receiver noise temperature increases roughly linearly with frequency. At 4.3 THz, we measured a receiver noise temperature of 1300 K, which is about 6 times (hf/k B) . The noise data at different frequencies are compared to a prediction of a noise model including the contribution of quantum noise and making use of a hot-spot model for mixing. We draw a preliminary conclusion that at 4.3 THz roughly 30% of the receiver noise temperature can be ascribed to the quantum noise. However, more dedicated measurements are required in order to further support the quantum noise model for HEB mixers.
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| 2. |
- Rotoli, G., et al.
(författare)
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Eck-Like Resonances in High-T-c Long Faceted Josephson Junctions
- 2009
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Ingår i: IEEE Transactions on Applied Superconductivity. - 1558-2515 .- 1051-8223. ; 19:3, s. 911-915
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Tidskriftsartikel (refereegranskat)abstract
- By means of numerical simulations we study the dynamics of the phase difference in faceted long Josephson junctions. We compare our simulations with experiments on a sample of high quality high-Tc biepitaxial junctions. Adjusting junction length and dissipation to reproduce the observed data we found a significant agreement, which permits to identify the observed resonances mostly as Eck steps. Some considerations are also made on the requirements to observe flux-flow or Fiske resonances in these junctions.
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| 3. |
- Stornaiuolo, D, et al.
(författare)
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Sub-Micron YBa2Cu3O7-x Biepitaxial Junctions
- 2009
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Ingår i: IEEE Transactions on Applied Superconductivity. - 1558-2515 .- 1051-8223. ; 19:3, s. 174-177
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Tidskriftsartikel (refereegranskat)abstract
- We report on the fabrication and properties of sub-micron YBa2Cu3O7-x off-axis biepitaxial junctions. The vision behind this work is to set up a reliable nanotechnology processing to improve junctions' performances and reproducibility through the reduction of their size. We will illustrate the fabrication procedure employed and show the results obtained on samples where the transport parameters were tuned in a predictable way. Also, proofs of a clean barrier structure with few facets and low disorder were obtained.
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| 7. |
- Mandev, Ahmet, 1991, et al.
(författare)
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Factors impacting real-world fuel economy of plug-in hybrid electric vehicles in Europe - an empirical analysis
- 2024
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Ingår i: Environmental Research Communications. - 2515-7620. ; 6:5
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Tidskriftsartikel (refereegranskat)abstract
- Plug-in hybrid electric vehicles (PHEVs) combine an electric motor with an internal combustion engine and can reduce greenhouse gas emissions from transport if mainly driven on electricity. The environmental benefit of PHEVs strongly depends on its usage and charging behavior. Several studies have demonstrated low electric driving shares (EDS) of many PHEVs. However, there is limited evidence on which vehicle properties affect the EDS of PHEVs to which extent. Here, we provide an empirical and quantitative analysis of real-world EDS and fuel consumption and look at how they are impacted by factors related to vehicle properties such as range, system power and mass. We complement previous studies on real-world EDS and fuel consumption of PHEVs by combining two different data sets, with almost 100,000 vehicles in total, over 150 models in 41 countries, which is combined the largest PHEV sample in Europe to date to be analyzed in the literature. We find that an increase of 10 km of type approval range leads on average to 13%-17% fuel consumption decrease and 1%-4% EDS increase. Furthermore, a 1 kW increase in system power per 100 kg of vehicle mass is associated with an average increase of 7%-9% in fuel consumption and a decrease of up to 2% in EDS. We also find that long-distance driving and charging behavior are the largest non-technical factors for the deviation between type-approval and real-world data. Furthermore, PHEV fuel consumption and related tail-pipe emissions in Europe are on average higher than official EU values.
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| 8. |
- Mandev, Ahmet, 1991, et al.
(författare)
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The effect of plug-in hybrid electric vehicle charging on fuel consumption and tail-pipe emissions
- 2021
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Ingår i: Environmental Research Communications. - : IOP Publishing. - 2515-7620. ; 3:8
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Plug-in hybrid electric vehicles (PHEV) have an electric motor and an internal combustion engine and can reduce greenhouse gas emissions (GHG) from transport. However, their environmental benefit strongly depends on the charging behaviour. Several studies have analysed the GHG emissions from upstream electricity production, yet the impact of individual charging behaviour on PHEV tail-pipe carbon emissions has not been quantified from empirical data so far. Here, we use daily driving data from 7,491 Chevrolet Volt PHEV with a total 3.4 million driving days in the US and Canada to fill this gap. We quantify the effect of daily charging on the electric driving share and the individual fuel consumption. We find that even a minor deviation from charging every driving day significantly increases fuel consumption and thus tail-pipe emissions. Our results show that reducing charging from every day to 9 out of 10 days, increases fuel consumption on average by 1.85 +/- 0.03 l/100 km or 42.7 +/- 0.8 gCO(2) km(-1) tail-pipe emissions (+/- on standard error). Charging more than once per driving day has less impact in our sample, this must occur during at least 20% of driving days to have a noteworthy effect. Even then, a 10% increase in frequency only has moderate effect of decreasing fuel consumption on average by 0.08 +/- 0.02 l/100 km or 1.86 +/- 0.46 gCO(2) km(-1) tail-pipe emissions. Our results illustrate the importance of providing adequate charging infrastructure and incentives for PHEV users to charge their vehicles on a regular basis in order to ensure that their environmental impact is small as even long-range PHEVs can have a noteworthy share of conventional fuel use when not regularly charged.
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| 9. |
- Pietrow, Alexander, 1991-, et al.
(författare)
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Inverse Chop Addition : Thermal IR Background Subtraction without Nodding
- 2019
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Ingår i: Research Notes of the AAS. - : American Astronomical Society. - 2515-5172. ; 3:2
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Due to the large size and mass of the secondary mirror on next generation extremely large telescopes it will not be possible to provide classical chopping and nodding as is used during mid-IR observations today. As a solution to this we propose an alternative approach to thermal background reduction called `inverse chop addition`. Here we use the symmetries of the thermal background to replace nodding, which allows us to get nearly identical background reductions while only using a special chopping pattern. The performance of this method was tested during technical time observations on VLT/VISIR. With this method, a higher observational efficiency can be obtained than with `classical chopping and nodding`, while achieving equally good reduction results. These results suggest that `inverse chop addition` could be a good alternative for classical chopping and nodding on both current and next generation ground-based facilities.
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| 10. |
- Mason, Elliot C., 1991-
(författare)
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Thing : A Fugitive In( )Operation
- 2020
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Ingår i: Journal of Italian Philosophy. - 2515-6039. ; 3, s. 163-189
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Tidskriftsartikel (refereegranskat)abstract
- ‘Thing’ conducts an antiracist intervention in Agamben’s “inoperativity”, operating contemporary Black studies into Agamben’s Heideggerian absences. Opening the subject to the impotentiality of Bartleby the Scrivener’s preference not to, Agamben seeks to disable the mechanisms of the world for a new politics. However, this poetics leaves the internal constitution of the subject, allowing the forces of operativity to maintain their operation as the constitutive ontology of subjectivity. Into this troubling remnant in Agamben I bring Hortense Spillers, who explores the constitution of the non- or anti-subject, constructed through the racializing operation of subjectivity that allows Agamben’s subject to remain intact throughout the process of being rendered inoperative. The Black non-subject, Spillers theorizes, is not constituted by the body that Agamben’s (White) subject requires; instead, she is formed of flesh, which is antecedent to subjectivity’s hegemonic form. Flesh is the materiality of racialization in the operativity of world. Fred Moten’s numerous works on Blackness and otherwise ontologies allow this deep aporia in Agamben’s thinking to open into a radical poetics of antiracist inoperativity, disavowing its constitutive subjectivity. In this essay, I closely read Agamben and Heidegger, with the thinking of Hortense Spillers, Sianne Ngai, C. Riley Snorton, Alexander Weheliye and Fred Moten, arriving somewhere closer to the Black beyond of inoperativity’s antiracist refusal.
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