| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Haziza, Frédéric, et al.
(författare)
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Pointer Race Freedom
- 2016
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Ingår i: Verification, Model Checking, And Abstract Interpretation, VMCAI 2016. - Berlin, Heidelberg : Springer. - 9783662491225 - 9783662491218 ; , s. 393-412
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Konferensbidrag (refereegranskat)abstract
- We propose a novel notion of pointer race for concurrent programs manipulating a shared heap. A pointer race is an access to a memory address which was freed, and it is out of the accessor's control whether or not the cell has been re-allocated. We establish two results. (1) Under the assumption of pointer race freedom, it is sound to verify a program running under explicit memory management as if it was running with garbage collection. (2) Even the requirement of pointer race freedom itself can be verified under the garbage-collected semantics. We then prove analogues of the theorems for a stronger notion of pointer race needed to cope with performance-critical code purposely using racy comparisons and even racy dereferences of pointers. As a practical contribution, we apply our results to optimize a thread-modular analysis under explicit memory management. Our experiments confirm a speedup of up to two orders of magnitude.
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| 3. |
- Saini, Apurve, et al.
(författare)
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Layering of magnetic nanoparticles at amorphous magnetic templates with perpendicular anisotropy
- 2020
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Ingår i: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-683X .- 1744-6848. ; 16:33, s. 7676-7684
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Tidskriftsartikel (refereegranskat)abstract
- We reveal the assembly of magnetite nanoparticles of sizes 5 nm, 15 nm and 25 nm from dilute water-based ferrofluids onto an amorphous magnetic template with out-of-plane anisotropy. From neutron reflectometry experiments we extract density profiles and show that the particles self-assemble into layers at the magnetic surface. The layers are extremely stable against cleaning and rinsing of the substrate. The density of the layers is determined by and increases with the remanent magnetic moment of the particles.
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| 4. |
- Wiesmaier, Sebastian, et al.
(författare)
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Magmatic Differentiation in the Teide–Pico Viejo Succession : Isotope Analysis as a Key to Deciphering the Origin of Phonolite Magma
- 2013
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Ingår i: Teide Volcano. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642258923 - 9783642258930 ; , s. 173-190
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Bokkapitel (refereegranskat)abstract
- In Tenerife, lavas of the recent Teide–Pico Viejo central complex show a marked bimodality in composition from initially mafic lava (200–30 ka) to highly differentiated phonolite (30–0 ka). Groundmass Sr–Nd–Pb–O and feldspar 18O data demonstrate open system behaviour for the petrogenesis of Teide–Pico Viejo felsic lavas, but contamination by ocean sediment can be excluded due to the low 206Pb/204Pb ratios of North Atlantic sediment. Isotope mixing hyperbolae require an assimilant of predominantly felsic composition for the Teide–Pico Viejo succession. Unsystematic and heterogeneous variation of 18O in fresh and unaltered feldspars across the Teide–Pico Viejo succession indicates magmatic addition of diverse 18O assimilants, best matched by nepheline syenites that occur as fresh and altered lithic blocks in voluminous pre-Teide ignimbrite deposits. Rare earth element modelling indicates that nepheline syenite needs to be melted in bulk to form a suitable end-member composition. Energy-Constrained Assimilation Fractional Crystallisation (EC-AFC) modelling reproduces the bulk of the succession, which implies that the petrogenesis of Teide–Pico Viejo lavas is governed by the coupled assimilation of nepheline syenite during fractional crystallisation. The most differentiated (and most radiogenic) lava computes to >97.8 % assimilant, likely represented by a nepheline syenite bulk melt that formed by underplating with juvenile mafic material. These recent research developments therefore recognise a wider variability of magmatic differentiation processes at Teide–Pico Viejo than previously considered.
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| 5. |
- Wiesmaier, Sebastian, et al.
(författare)
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Open-system processes in the differentiation of mafic magma in the Teide-Pico Viejo succession, Tenerife
- 2013
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Ingår i: Journal of the Geological Society. - : Geological Society of London. - 0016-7649 .- 2041-479X. ; 170:3, s. 557-570
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Tidskriftsartikel (refereegranskat)abstract
- Oceanic island basalts are commonly thought to differentiate by fractional crystallization, yet closed-system fractionation models have so far failed to reproduce major and trace element variations observed in mafic lavas from the Teide-Pico Viejo stratovolcano complex on Tenerife. Here, new high-precision plagioclase trace element data are fed into such a fractionation model. The results confirm that fractionation of phenocrysts found in the lavas does not reproduce trace element variations, in particular enrichment of Sr and Zr observed in the Teide-Pico Viejo mafic suite. This enrichment of Sr and Zr is tested by an energy-constrained recharge, assimilation and fractional crystallization (EC-RAFC) model at high T and low Lambda T intervals, consistent with previously determined magma storage beneath Tenerife at sub-Moho depths. Published mineral-melt equilibrium relations using the plagioclase anorthite content (0.4 < X-An < 0.8) constrain the temperature during differentiation. Gabbroic xenoliths found in Tenerife lavas are assumed as contaminant. Enrichment of Sr and Zr in the Teide mafic suite is reproduced by this combined assimilation and fractional crystallization model, as assimilation causes higher degrees of enrichment in incompatible trace elements than is possible by crystal fractionation alone. Recycling of plutonic roots may thus have significantly enriched trace elements in the primitive lavas of the Teide-Pico Viejo succession.
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