| 11. |
- Alam, Syed Bahauddin, et al.
(författare)
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Small modular reactor core design for civil marine propulsion using micro-heterogeneous duplex fuel. Part I: Assembly-level analysis
- 2019
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Ingår i: Nuclear Engineering and Design. - : Elsevier BV. - 0029-5493 .- 1872-759X. ; 346, s. 157-175
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Tidskriftsartikel (refereegranskat)abstract
- In an effort to de-carbonise commercial freight shipping, there is growing interest in the possibility of using nuclear propulsion systems. In this reactor physics study, we seek to design a soluble-boron-free (SBF) and low-enriched uranium (LEU) (<20% U-235 enrichment) civil nuclear marine propulsion small modular reactor (SMR) core that provides at least 15 effective full-power-years (EFPY) life at 333 MWth using 18% U-235 enriched micro-heterogeneous ThO2-UO2 duplex fuel and 15% U-235 enriched homogeneously mixed all-UO2 fuel. We use WIMS to develop subassembly designs and PANTHER to examine whole-core arrangements.The assembly-level behaviours of candidate burnable poison (BP) materials and control rods are investigated. We examine gadolinia (Gd2O3), erbia (Er2O3) and ZrB2 integral fuel burnable absorber (IFBA) as BPs. We arrive at a design with the candidate fuels loaded into 13 x 13 assemblies using IFBA pins for reactivity control. Taking advantage of self-shielding effects, this design maintains low and stable assembly reactivity with relatively little burnup penalty. Thorium-based duplex fuel offers better performance than all-UO2 fuel with all BP options considered. Duplex fuel has similar to 20% lower reactivity swing and, in consequence, lower initial reactivity than all-UO2 fuel. The lower initial reactivity and smaller reactivity swing make the task of reactivity control through BP design easier in the thorium-rich duplex core. For control rod design, we examine boron carbide (B4C), hafnium, and Ag-In-Cd alloy. All the candidate materials exhibit greater rod worth for the duplex design. For both fuels, B4C has the highest rod worth. In particular, one of the major objectives of this study is to offer/explore a thorium-based candidate alternative fuel platform for the proposed marine core. It is proven by literature reviews that the ability of the duplex fuel was never explored in the context of a single-batch, LEU, SBF, long-life SMR core. In this regard, the motivation of this paper is to observe the neutronic performance of the proposed duplex fuel with respect to the UO2 fuel and 'open the option' of designing the functional cores with both the duplex and UO2 fuel cores.
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| 12. |
- Bhattacharya, S., et al.
(författare)
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Evolution of collectivity and evidence of octupole correlations in Br 73
- 2019
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Ingår i: Physical Review C. - 2469-9985. ; 100:1
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in the Br73 nucleus have been populated via the Cr50(Si28,αp)Br73 fusion evaporation reaction with a beam energy of 90 MeV. The deexciting gamma rays were detected using the Indian National Gamma Array (INGA). Using the γ-γ coincidence technique, two new bands and eight new interconnecting transitions have been added. The strong interconnecting E1 transitions, between positive and negative parity bands, ensure the existence of octupole correlations at low spin. Line shapes have been observed for 17 transitions, which were analyzed by the Doppler-shift attenuation method to determine the lifetime of excited states of the yrast negative parity band and its signature partner band along with the positive parity band. The deduced transitional quadrupole moments Qt for the ground state band decrease with increasing spin, with their values ranging from 2.88 to 1.00 eb. A similar trend in the quadrupole moment has also been observed for the signature partner as well as for the positive parity band. This decrease in Qt with increasing spin for these bands is interpreted in terms of the cranked Nilsson-Strutinsky model and total Routhian surface calculations, which indicate possible band termination at higher spin.
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| 13. |
- Kumar, S., et al.
(författare)
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Band structures in Rh-99
- 2014
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Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 41:10
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Tidskriftsartikel (refereegranskat)abstract
- Excited states in the Rh-99 nucleus were populated using the fusion-evaporation reaction As-75(Si-28,2p2n) at E-lab = 120 MeV and the de-excitations were investigated through in-beam gamma-ray spectroscopic techniques using the INGA spectrometer consisting of 18 clover detectors. The observed band structures are discussed in the framework of tilted axis cranking shell-model calculations. Level structures at low energies are identified as resulting from the rotational bands based on the pi p(1/2) and pi g(9/2) configurations. The Delta I = 1 coupled bands are observed at higher excitation energies and have been interpreted as based on the pi g(9/2) circle times nu g(7/2) circle times nu d(5/2), pi p(1/2) circle times nu h(11/2) circle times nu d(5/2) and pi g(9/2) circle times nu h(11/2) circle times nu g(7/2) configurations. Calculations based on cranked Nilsson- Strutinsky (CNS) formalism have been performed to interpret the favoured states with I-pi = (41/2(-), 43/2(-)) and (51/2(-), 53/2(-)) as maximal spin aligned states built on the valence space nu(d(5/2)g(7/2))(15/2)(3), (17/2)(h(11/2))(11/2)(1) configuration combined with the fully-aligned pi(g(9/2))(25/2)(5) configuration and the pi(g(9/2))(15/2)(5) configuration with one anti-aligned g(9/2) proton, respectively.
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| 14. |
- Lombardo, Teo, et al.
(författare)
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Artificial Intelligence Applied to Battery Research: Hype or Reality?
- 2022
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Ingår i: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 122:12, s. 10899 -10969
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Forskningsöversikt (refereegranskat)abstract
- This is a critical review of artificial intelligence/machine learning (AI/ML) methods applied to battery research. It aims at providing a comprehensive, authoritative, and critical, yet easily understandable, review of general interest to the battery community. It addresses the concepts, approaches, tools, outcomes, and challenges of using AI/ML as an accelerator for the design and optimization of the next generation of batteries - a current hot topic. It intends to create both accessibility of these tools to the chemistry and electrochemical energy sciences communities and completeness in terms of the different battery RD aspects covered.
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| 15. |
- Pervjakova, Natalia, et al.
(författare)
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Multi-ancestry genome-wide association study of gestational diabetes mellitus highlights genetic links with type 2 diabetes
- 2022
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 31:19, s. 3377-3391
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Tidskriftsartikel (refereegranskat)abstract
- Gestational diabetes mellitus (GDM) is associated with increased risk of pregnancy complications and adverse perinatal outcomes. GDM often reoccurs and is associated with increased risk of subsequent diagnosis of type 2 diabetes (T2D). To improve our understanding of the aetiological factors and molecular processes driving the occurrence of GDM, including the extent to which these overlap with T2D pathophysiology, the GENetics of Diabetes In Pregnancy (GenDIP) Consortium assembled genome-wide association studies (GWAS) of diverse ancestry in a total of 5485 women with GDM and 347 856 without GDM. Through multi-ancestry meta-analysis, we identified five loci with genome-wide significant association (p < 5x10-8) with GDM, mapping to/near MTNR1B (p = 4.3x10-54), TCF7L2 (p = 4.0x10-16), CDKAL1 (p = 1.6 × 10-14), CDKN2A-CDKN2B (p = 4.1x10-9) and HKDC1 (p = 2.9x10-8). Multiple lines of evidence pointed to the shared pathophysiology of GDM and T2D: (i) four of the five GDM loci (not HKDC1) have been previously reported at genome-wide significance for T2D; (ii) significant enrichment for associations with GDM at previously reported T2D loci; (iii) strong genetic correlation between GDM and T2D; and (iv) enrichment of GDM associations mapping to genomic annotations in diabetes-relevant tissues and transcription factor binding sites. Mendelian randomisation analyses demonstrated significant causal association (5% false discovery rate) of higher body mass index on increased GDM risk. Our results provide support for the hypothesis that GDM and T2D are part of the same underlying pathology but that, as exemplified by the HKDC1 locus, there are genetic determinants of GDM that are specific to glucose regulation in pregnancy.
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| 16. |
- Ulrich, Anke S., et al.
(författare)
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Pt accelerated coarsening of A15 precipitates in Cr-Si alloys
- 2022
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Ingår i: Materials and Design. - : Elsevier BV. - 1873-4197 .- 0264-1275. ; 218
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Tidskriftsartikel (refereegranskat)abstract
- The effect of alloying Cr-rich Cr-Si alloys with Pt was investigated by a combination of complementary experimental methods and atomic scale modelling. The investigated Cr-Si and Cr-Si-Pt (Cr ⩾86 at.%) alloys developed a two-phase microstructure consisting of Cr solid solution (Crss) matrix and strengthened by A15 precipitates during annealing at 1200°C. It was found that additions of 2 at.% Pt increase the coarsening rate by almost five times considering annealing times up to 522 h. Pt was found to change the precipitate matrix orientation relationship, despite its low influence on the Crss matrix/A15 precipitate misfit. Through this experimental and modelling approach new insight has been gained into mechanisms of enhanced coarsening by Pt addition. The increased coarsening is principally attributed to a change in interface composition and structure resulting in different thermodynamic stabilities: Pt-containing A15 phase was found to have a broader compositional range if both elements, Pt and Si, are present compared to only Si. Additionally, the Crss phase was found to have a higher solubility of Pt and Si over just Si. Both factors additionally facilitated Ostwald ripening.
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