| 1. |
- Santala, M. I. K., et al.
(författare)
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Proton-triton nuclear reaction in ICRF heated plasmas in JET
- 2006
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 0741-3335 .- 1361-6587. ; 48:8, s. 1233-1253
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Tidskriftsartikel (refereegranskat)abstract
- Fast protons can react with tritons in an endothermic nuclear reaction which can act as a source of neutrons in magnetically confined fusion plasmas. We have performed an experiment to systematically study this reaction in low tritium concentration (approximate to 1%) plasmas in the Joint European Torus. A linear dependence is found between excess neutron rate and tritium concentration when the DT fusion rate is low. We discuss the properties of the neutron emission, including anisotropy, from the proton-triton reaction in a fusion reactor environment and derive simple models for the calculation of the neutron yield from this reaction in terms of tritium density, fast ion temperature and fast ion energy content.
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| 2. |
- Sökjer-Petersen, Marianne
(författare)
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Network, growth and women, entrepreneurs
- 2002
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Ingår i: Women, Work & Health. Book of abstracts. III international congress in Stockholm 2002. - 9170456402 ; , s. 299-299
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Konferensbidrag (refereegranskat)
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| 3. |
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| 4. |
- Sonagara, Abhishek Maganbhai, et al.
(författare)
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Ultra-Thin Flexible Uniplanar Antenna Based on SSPP for B5G Radio Stripe Network
- 2023
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1536-1225 .- 1548-5757. ; 22:8, s. 1947-1951
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Tidskriftsartikel (refereegranskat)abstract
- In this letter, a flexible and ultra-thin uniplanar end fire antenna employing spoof surface plasmon polariton (SSPP) is proposed. The single-metal layered groundless structure is an inherent advantage of the SSPP. At the SSPP transmission line's end, a metallic strip is added asymmetrically for wideband radiation, resulting in an observed tilting of the main lobe in the azimuthal plane. Three C-shaped directors are used to enhance the directivity. The proposed antenna is fabricated and measured over flat and curved surfaces of brick wall and wood with two different radii. The proposed antenna has a low profile of 0.001710 and a small volume of 0.0058?(3)(0), where 10 is the free-space wavelength at the center frequency of the operating bandwidth. The antenna has an impedance bandwidth of 33.7% with a peak gain of 8.5 dBi. Measurements indicate no significant degradation in the proposed antenna's performance in different scenarios. Due to features like flexibility, ultra-thin profile, very low volume, tilted beam with high gain, and wideband operation, the proposed antenna is highly suitable for beyond fifth-generation (B5G) radio stripe applications.
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| 5. |
- Issa, Mohamed Mahmoud, 1974-
(författare)
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Linear and Branched Chitosan Oligomers as Delivery Systems for pDNA and siRNA In Vitro and In Vivo
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, chitosan, a biocompatible polysaccharide that has been approved as a food additive was selected as a platform for the development of safe, efficient non-viral gene delivery systems to mammalian cells. Previously, chitosan-based gene formulations had been generally associated with high molecular weight chitosans, which were poorly characterised in terms of molecular weight distribution and degree of acetylation. Therefore, in order to improve the properties of chitosan-based gene formulations, the research associated with this thesis focused on establishing the structure-property relationships of well-defined, low molecular weight chitosans (chitosan oligomers) as delivery systems for nucleic acids (pDNA and siRNA) in vitro and after lung administration in vivo. pDNA dissociated more easily from chitosan oligomers than from conventional high molecular weight chitosans, resulting in a faster onset and higher levels of in vivo gene expression, comparable to those mediated by polyethyleneimine (PEI), one of the most efficient non-viral delivery systems. Coupling of a trisaccharide branch to the chitosan oligomers so as to target extracellular lectins resulted in a significant improvement in transfection efficiency because of enhanced cellular uptake and colloidal stability. In contrast to pDNA, longer linear chitosan oligomers were required to form physically-stable nanoparticles with siRNA that mediated efficient, sustained gene silencing in vitro. Finally, the use of an optimised catheter device for the nebulisation of small volumes of pDNA formulations resulted in improved dose precision and lung distribution in vivo compared with conventional intratracheal instillation. In conclusion, chitosan oligomers are interesting and viable alternatives to other non-viral gene delivery systems.
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| 6. |
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| 7. |
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| 8. |
- Akiyama, J, et al.
(författare)
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Benign and precursor lesions in the esophagus
- 2014
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Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 1749-6632 .- 0077-8923. ; 1325, s. 226-241
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Akiyama, Kazunori, et al.
(författare)
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First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
- 2019
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 875:1
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Tidskriftsartikel (refereegranskat)abstract
- We present the calibration and reduction of Event Horizon Telescope (EHT) 1.3 mm radio wavelength observations of the supermassive black hole candidate at the center of the radio galaxy M87 and the quasar 3C 279, taken during the 2017 April 5-11 observing campaign. These global very long baseline interferometric observations include for the first time the highly sensitive Atacama Large Millimeter/submillimeter Array (ALMA); reaching an angular resolution of 25 μas, with characteristic sensitivity limits of ∼1 mJy on baselines to ALMA and ∼10 mJy on other baselines. The observations present challenges for existing data processing tools, arising from the rapid atmospheric phase fluctuations, wide recording bandwidth, and highly heterogeneous array. In response, we developed three independent pipelines for phase calibration and fringe detection, each tailored to the specific needs of the EHT. The final data products include calibrated total intensity amplitude and phase information. They are validated through a series of quality assurance tests that show consistency across pipelines and set limits on baseline systematic errors of 2% in amplitude and 1° in phase. The M87 data reveal the presence of two nulls in correlated flux density at ∼3.4 and ∼8.3 Gλ and temporal evolution in closure quantities, indicating intrinsic variability of compact structure on a timescale of days, or several light-crossing times for a few billion solar-mass black hole. These measurements provide the first opportunity to image horizon-scale structure in M87.
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| 10. |
- Akiyama, Kazunori, et al.
(författare)
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First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
- 2019
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 875:1
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Tidskriftsartikel (refereegranskat)abstract
- We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of similar to 40 mu as, consistent with the size and shape of the lensed photon orbit encircling the "shadow" of a supermassive black hole. The ring is persistent across four observing nights and shows enhanced brightness in the south. To assess the reliability of these results, we implemented a two-stage imaging procedure. In the first stage, four teams, each blind to the others' work, produced images of M87 using both an established method (CLEAN) and a newer technique (regularized maximum likelihood). This stage allowed us to avoid shared human bias and to assess common features among independent reconstructions. In the second stage, we reconstructed synthetic data from a large survey of imaging parameters and then compared the results with the corresponding ground truth images. This stage allowed us to select parameters objectively to use when reconstructing images of M87. Across all tests in both stages, the ring diameter and asymmetry remained stable, insensitive to the choice of imaging technique. We describe the EHT imaging procedures, the primary image features in M87, and the dependence of these features on imaging assumptions.
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