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- Rathsman, Karin, et al.
(författare)
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The RF power source for the high beta elliptical cavities of the ESS linac
- 2011
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Ingår i: ; , s. 397-399
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The European Spallation Source (ESS) is an intergovernmental project building amultidisciplinary research laboratory based upon the worlds most powerful neutron source. The main facility will be built in Lund, Sweden. Construction is expected to start around 2013 and the first neutrons will be produced in 2019. The ESS linac will deliver 5 MW of power to the target at 2.5 GeV, with a nominal current of 50 mA. The 120 high beta elliptical cavities, which operate at a frequency of 704 MHz and accelerate protons from 600 MeV to 2.5 GeV, account for more than half of the total number of RF cavities in the ESS linac and three quarters of the total beam power needed. Because of the large number of RF power sources and the high power level needed, all the design and development efforts for the RF power source have so far been focused on this part of the accelerator. The design and development status of the RF power source is reported in this paper with emphasis on reliability, maintainability, safety, power efficiency, investment cost and production capacity.
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2. |
- Hill, Victoria C R, et al.
(författare)
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Particle-in-cell simulation of the third harmonic cavity F-Tube klystron
- 2016
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Ingår i: 2016 IEEE International Vacuum Electronics Conference, IVEC 2016. - 9781467392167
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Konferensbidrag (refereegranskat)abstract
- Use of a second harmonic and third harmonic cavity within a klystron to increase efficiency has been studied using particle-in-cell (PIC) code, MAGIC 2D. The six cavity device has a drive frequency of 1GHz, a predicted efficiency of 88%, 39 dB gain and an output power of 833 kW. The preliminary simulation results have revealed indications of bunching with bunch core oscillations. The initial results and analysis of the F-Tube PIC study are presented.
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3. |
- Mylvaganam, M, et al.
(författare)
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Interaction of the verotoxin 1B subunit with soluble aminodeoxy analogues of globotriaosyl ceramides
- 2002
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Ingår i: Biochemical Journal. - 0264-6021. ; 368, s. 769-776
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Tidskriftsartikel (refereegranskat)abstract
- Specific hydroxy groups of the terminal disaccharide unit of globotriaosyl ceramide (Gb(3)Cer) were identified from binding studies with deoxyGb(3)Cer and verotoxins (VTs) [Nyholm, Magnusson, Zheng, Norel, Birmington-Boyd and Lingwood (1996) Chem. Biol. 3, 263-275]. Four such hydroxy groups (2", 4", 6" and 6') were each substituted with an amino group and the corresponding deoxyamino globotrioses were conjugated to a ceramide-like aglycone which contained an adamantyl group instead of an acyl chain. Such aglycone modification significantly enhanced the water-solubility of the glycoconjugates [Mylvaganam and Lingwood (1999) Biochem. Biophys. Res. Commun. 257, 391-394]. The inhibitory potential of these soluble aminodeoxy conjugates on the binding of VT1 to Gb(3)Cer immobilized on an ELISA plate was evaluated. Only the 2" and the 6' deoxyamino conjugates were effective inhibitors (IC50 10 muM); the 4" and 6" conjugates were ineffective up to 10 mM. To evaluate the importance of incorporating a rigid adamantyl hydrocarbon group into the ceramide aglycone, globotriaose was conjugated to a t-butylacetamido or an adamantaneacetamido aglycone. By similar ELISAs, only the adamantaneacetamido conjugate inhibited the binding of VT1 to Gb(3)Cer. When deoxyamino conjugates were adsorbed to silica on TLC plates, only the 2" and 6" conjugates bound VT1 and VT2. By a similar TLC assay, acetamido derivatives of 2" and 6' deoxyamino conjugates showed less binding to VT1 and VT2. Neither the crystallographically determined structure of the VT1- globotriaose complex nor modelling studies fully explain the binding patterns shown by these deoxyamino glycoconjugates. Enhanced solvation of the ammonium group of the deoxyamino conjugate could enforce greater constraints in the binding interactions.
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4. |
- Seoane, Fernando, et al.
(författare)
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Automated criterion-based analysis for Cole parameters assessment from cerebral neonatal electrical bioimpedance spectroscopy measurements
- 2012
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Ingår i: Physiological Measurement. - : IOP Publishing. - 0967-3334 .- 1361-6579. ; 33:8, s. 1363-1377
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Tidskriftsartikel (refereegranskat)abstract
- Hypothermia has been proven as an effective rescue therapy for infants with moderate or severe neonatal hypoxic ischemic encephalopathy. Hypoxiaischemia alters the electrical impedance characteristics of the brain in neonates; therefore, spectroscopic analysis of the cerebral bioimpedance of the neonate may be useful for the detection of candidate neonates eligible for hypothermia treatment. Currently, in addition to the lack of reference bioimpedance data obtained from healthy neonates, there is no standardized approach established for bioimpedance spectroscopy data analysis. In this work, cerebral bioimpedance measurements (12 h postpartum) in a cross-section of 84 term and near-term healthy neonates were performed at the bedside in the post-natal ward. To characterize the impedance spectra, Cole parameters (R-0, R-infinity, f(C) and alpha) were extracted from the obtained measurements using an analysis process based on a best measurement and highest likelihood selection process. The results obtained in this study complement previously reported work and provide a standardized criterion-based method for data analysis. The availability of electrical bioimpedance spectroscopy reference data and the automatic criterion-based analysis method might support the development of a non-invasive method for prompt selection of neonates eligible for cerebral hypothermic rescue therapy.
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