| 1. |
- Atac Nyberg, Ayse, et al.
(författare)
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Discrimination of gamma rays due to inelastic neutron scattering in AGATA
- 2009
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 607:3, s. 554-563
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Tidskriftsartikel (refereegranskat)abstract
- Possibilities of discriminating neutrons and gamma rays in the AGATA gamma-ray tracking spectrometer have been investigated with the aim of reducing the background due to inelastic scattering of neutrons in the high-purity germanium crystals. This background may become a serious problem especially in experiments with neutron-rich radioactive ion beams. Simulations using the GEANT4 toolkit and a tracking program based on the forward tracking algorithm were carried out by emitting neutrons and gamma rays from the center of AGATA. Three different methods were developed and tested in order to find "fingerprints" of the neutron interaction points in the detectors. In a simulation with simultaneous emission of six neutrons with energies in the range 1-5 MeV and 10 gamma rays with energies between 150 and 1450 keV, the peak-to-background ratio at a gamma-ray energy of 1.0 MeV was improved by a factor of 2.4 after neutron rejection with a reduction of the photopeak efficiency at 1.0 MeV of only a factor of 1.25. (C) 2009 Elsevier B.V. All rights reserved.
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| 2. |
- Liu, Johan, 1960, et al.
(författare)
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Stem Cell Growth and Migration on Nanofibrous Polymer Scaffolds and Micro-Fluidic Channels on Silicon-Chip
- 2009
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Ingår i: Proceedings of the 2009 Electronic Components and Technology Conference. - 0569-5503. - 9781424444762 ; , s. 1080-1085
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Konferensbidrag (refereegranskat)abstract
- Stem cell growth and migration on nanofibrous scaffolds and micro-fluidic channels on Silicon-Chip were studied by using neural stem cells isolated from adult rats' brain. Electrospinning and lithographic technique were used for developing nanofibrous-polylactic acid (PLA) and polyurethane (PU) based-scaffolds and micro-fluidic channels on Si-Chips respectively. Immunocytochemical and morphological analysis showed better cell-matrix interaction with profound adhesion, proliferation and migration on the developed scaffolds. Cell culture assay with microfluidic channel revealed the ability of developed channel system in guiding neuronal stem cell growth towards specified directions. These studies extend the possibility of using developed nanofibrous scaffolds and micro-fluidic channel system for future electrical signal transmission based on living neural stem cells.
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| 3. |
- Widell, Niklas, et al.
(författare)
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Gateway-based call admission in distributed object oriented systems
- 2000
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Ingår i: Proceedings fifteenth Nordic Teletraffic Seminar, NTS-15, Lund University, August 22-24, 2000.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Many applications in telecommunications will depend on distributed systems to provide enough capacity. In a distributed system a service is split up into a number of modules (often called objects) that can be placed at different nodes or processors in a network. A service can be seen as a number of invocations of the objects in a certain order. There are a number of performance problems which have to be solved. How shall objects be distributed on the nodes? How shall the load be distributed among the nodes for a given object distribution? How shall the distributed system be protected from temporary overload situations? In our paper we investigate these questions for distributed systems where requests for service arrive to a gateway from which they distributed to the nodes of the system. We assume that the object distribution is given and we concentrate on protecting the system using three different external load control mechanisms: Percent Thinning, Call Gapping and Tokens. Using simulations, we nd that Tokens provide the best system protection.
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| 4. |
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| 5. |
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| 6. |
- Andgren, Karin, et al.
(författare)
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Low-spin collective behavior in the transitional nuclei Mo-86,Mo-88
- 2007
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 76:1, s. 014307-
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Tidskriftsartikel (refereegranskat)abstract
- Low-spin structures in Mo-86,Mo-88 were populated using the Ni-58(Ar-36, x alpha yp) heavy-ion fusion-evaporation reaction at a beam energy of 111 MeV. Charged particles and gamma rays were emitted in the reactions and detected by the DIAMANT CsI ball and the EXOGAM Ge array, respectively. In addition to the previously reported low-to-medium spin states in these nuclei, new low-spin structures were observed. Angular correlation and linear polarization measurements were performed in order to unambiguously determine the spins and parities of intensely populated states in Mo-88. Quasiparticle Random Phase Approximation (QRPA) calculations were performed for the first and second excited 2(+) states in Mo-86 and Mo-88. The results are in qualitative agreement with the experimental results, supporting a collective interpretation of the low-spin states for these transitional nuclei.
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| 7. |
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| 8. |
- Annersten Gershater, Magdalena, et al.
(författare)
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Complexity of factors related to outcome of neuropathic and neuroischaemic/ischaemic diabetic foot ulcers: a cohort study
- 2009
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 52:3, s. 398-407
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Tidskriftsartikel (refereegranskat)abstract
- We sought to identify factors related to short-term outcome of foot ulcers in patients with diabetes treated in a multidisciplinary system until healing was achieved. Consecutively presenting patients with diabetes and worst foot ulcer (Wagner grade 1-5, below ankle) (n = 2,511) were prospectively followed and treated according to a standardised protocol until healing was achieved or until death. The number of patients lost to dropout was 31. The characteristics of the remaining 2,480 patients were: 1,465 men, age 68 +/- 15 years (range 18-96), type 1 diabetes 18%, type 2 diabetes 82% and insulin-treated 62%. The healing rate without major amputation in surviving patients was 90.6% (n = 1,867). Sixty-five per cent (n = 1,617) were healed primarily, 9% (n = 250) after minor amputation and 8% after major amputation; 17% (n = 420) died unhealed. Out of 2,060 surviving patients, 1,007 were neuroischaemic (48.8%). In a multiple regression analysis, primary healing was related to co-morbidity, duration of diabetes, extent of peripheral vascular disease and type of ulcer. In neuropathic ulcers, deep foot infection, site of ulcer and co-morbidity were related to amputation. Amputation in neuroischaemic ulcers was related to co-morbidity, peripheral vascular disease and type of ulcer. Age, sex, duration of diabetes, neuropathy, deformity and duration of ulcer or site of ulcer did not have an evident influence on probability of amputation. Patients with diabetic foot ulcer suffer from multi-organ disease. Factors related to outcome are correspondingly complex.
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| 9. |
- Assié, M., et al.
(författare)
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Neutron correlations in 6He viewed through nuclear break-up
- 2009
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 42:3, s. 441-446
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Tidskriftsartikel (refereegranskat)abstract
- The nuclear break-up of He-6 on a Pb-208 target was studied at 20 A MeV using a secondary beam of He-6 produced by the SPIRAL facility at GANIL. alpha-particles were detected in coincidence with two neutrons with a large angular coverage and the reaction mechanism was identified. From the distribution of the relative angles between the two neutrons the correlation function was extracted. It shows a strong correlation at small relative angles attributed to the contribution of the di-neutron configuration of He-6.
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| 10. |
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