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| 2. |
- Faatz, B., et al.
(författare)
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Simultaneous operation of two soft x-ray free-electron lasers driven by one linear accelerator
- 2016
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Extreme-ultraviolet to x-ray free-electron lasers (FELs) in operation for scientific applications are up to now single-user facilities. While most FELs generate around 100 photon pulses per second, FLASH at DESY can deliver almost two orders of magnitude more pulses in this time span due to its superconducting accelerator technology. This makes the facility a prime candidate to realize the next step in FELs-dividing the electron pulse trains into several FEL lines and delivering photon pulses to several users at the same time. Hence, FLASH has been extended with a second undulator line and self-amplified spontaneous emission (SASE) is demonstrated in both FELs simultaneously. FLASH can now deliver MHz pulse trains to two user experiments in parallel with individually selected photon beam characteristics. First results of the capabilities of this extension are shown with emphasis on independent variation of wavelength, repetition rate, and photon pulse length.
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| 3. |
- Aoyama, T., et al.
(författare)
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The anomalous magnetic moment of the muon in the Standard Model
- 2020
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Ingår i: Physics reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 887, s. 1-166
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Forskningsöversikt (refereegranskat)abstract
- We review the present status of the Standard Model calculation of the anomalous magnetic moment of the muon. This is performed in a perturbative expansion in the fine-structure constant α and is broken down into pure QED, electroweak, and hadronic contributions. The pure QED contribution is by far the largest and has been evaluated up to and including O(α5) with negligible numerical uncertainty. The electroweak contribution is suppressed by (mμ/MW)2 and only shows up at the level of the seventh significant digit. It has been evaluated up to two loops and is known to better than one percent. Hadronic contributions are the most difficult to calculate and are responsible for almost all of the theoretical uncertainty. The leading hadronic contribution appears at O(α2) and is due to hadronic vacuum polarization, whereas at O(α3) the hadronic light-by-light scattering contribution appears. Given the low characteristic scale of this observable, these contributions have to be calculated with nonperturbative methods, in particular, dispersion relations and the lattice approach to QCD. The largest part of this review is dedicated to a detailed account of recent efforts to improve the calculation of these two contributions with either a data-driven, dispersive approach, or a first-principle, lattice-QCD approach. The final result reads aμSM = 116 591 810(43) x 10-11 and is smaller than the Brookhaven measurement by 3.7 σ. The experimental uncertainty will soon be reduced by up to a factor four by the new experiment currently running at Fermilab, and also by the future J-PARC experiment. This and the prospects to further reduce the theoretical uncertainty in the near future - which are also discussed here - make this quantity one of the most promising places to look for evidence of new physics.
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- Tomić, I., et al.
(författare)
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Shake-table testing of a stone masonry building aggregate : overview of blind prediction study
- 2023
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Ingår i: Bulletin of Earthquake Engineering. - : Springer Science and Business Media LLC. - 1570-761X .- 1573-1456.
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Tidskriftsartikel (refereegranskat)abstract
- City centres of Europe are often composed of unreinforced masonry structural aggregates, whose seismic response is challenging to predict. To advance the state of the art on the seismic response of these aggregates, the Adjacent Interacting Masonry Structures (AIMS) subproject from Horizon 2020 project Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe (SERA) provides shake-table test data of a two-unit, double-leaf stone masonry aggregate subjected to two horizontal components of dynamic excitation. A blind prediction was organized with participants from academia and industry to test modelling approaches and assumptions and to learn about the extent of uncertainty in modelling for such masonry aggregates. The participants were provided with the full set of material and geometrical data, construction details and original seismic input and asked to predict prior to the test the expected seismic response in terms of damage mechanisms, base-shear forces, and roof displacements. The modelling approaches used differ significantly in the level of detail and the modelling assumptions. This paper provides an overview of the adopted modelling approaches and their subsequent predictions. It further discusses the range of assumptions made when modelling masonry walls, floors and connections, and aims at discovering how the common solutions regarding modelling masonry in general, and masonry aggregates in particular, affect the results. The results are evaluated both in terms of damage mechanisms, base shear forces, displacements and interface openings in both directions, and then compared with the experimental results. The modelling approaches featuring Discrete Element Method (DEM) led to the best predictions in terms of displacements, while a submission using rigid block limit analysis led to the best prediction in terms of damage mechanisms. Large coefficients of variation of predicted displacements and general underestimation of displacements in comparison with experimental results, except for DEM models, highlight the need for further consensus building on suitable modelling assumptions for such masonry aggregates.
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- Dubernet, M. L., et al.
(författare)
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The virtual atomic and molecular data centre (VAMDC) consortium
- 2016
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 49:7
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Tidskriftsartikel (refereegranskat)abstract
- The Virtual Atomic and Molecular Data Centre (VAMDC) Consortium is a worldwide consortium which federates atomic and molecular databases through an e-science infrastructure and an organisation to support this activity. About 90% of the inter-connected databases handle data that are used for the interpretation of astronomical spectra and for modelling in many fields of astrophysics. Recently the VAMDC Consortium has connected databases from the radiation damage and the plasma communities, as well as promoting the publication of data from Indian institutes. This paper describes how the VAMDC Consortium is organised for the optimal distribution of atomic and molecular data for scientific research. It is noted that the VAMDC Consortium strongly advocates that authors of research papers using data cite the original experimental and theoretical papers as well as the relevant databases.
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| 7. |
- Jain, P, et al.
(författare)
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Conjunctival melanoma treatment outcomes in 288 patients: a multicentre international data-sharing study
- 2021
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Ingår i: The British journal of ophthalmology. - : BMJ. - 1468-2079 .- 0007-1161. ; 105:10, s. 1358-1364
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Tidskriftsartikel (refereegranskat)abstract
- To relate conjunctival melanoma characteristics to local control.MethodsRetrospective, registry-based interventional study with data gathered from 10 ophthalmic oncology centres from 9 countries on 4 continents. Conjunctival melanoma patients diagnosed between January 2001 and December 2013 were enrolled in the study. Primary treatments included local excision, excision with cryotherapy and exenteration. Adjuvant treatments included topical chemotherapy, brachytherapy, proton and external beam radiotherapy (EBRT). Cumulative 5-year and 10-year Kaplan-Meier local recurrence rates were related to clinical and pathological T-categories of the eighth edition of the American Joint Committee on Cancer (AJCC) staging system.Results288 patients had a mean initial age of 59.7±16.8 years. Clinical T-categories (cT) were cT1 (n=218,75.7%), cT2 (n=34, 11.8%), cT3 (n=15, 5.2%), cTx (n=21,7.3%) with no cT4. Primary treatment included local excision (n=161/288, 55.9%) followed by excision biopsy with cryotherapy (n=108/288, 37.5%) and exenteration (n=5/288, 1.7%). Adjuvant therapies included topical mitomycin (n=107/288, 37.1%), plaque-brachytherapy (n=55/288, 19.1%), proton-beam (n=36/288, 13.5%), topical interferon (n=20/288, 6.9%) and EBRT (n=15/288, 5.2%). Secondary exenteration was performed (n=11/283, 3.9%). Local recurrence was noted in 19.1% (median=3.6 years). Cumulative local recurrence was 5.4% (3.2–8.9%), 19.3% (14.4–25.5%) and 36.9% (26.5–49.9%) at 1, 5 and 10 years, respectively. cT3 and cT2 tumors were twice as likely to recur than cT1 tumours, but only cT3 had statistically significantly greater risk of local recurrence than T1 (p=0.013). Factors such as tumour ulceration, plica or caruncle involvement and tumour thickness were not significantly associated with an increased risk of local recurrence.ConclusionThis multicentre international study showed that eighth edition of AJCC tumour staging was related to the risk of local recurrence of conjunctival melanoma after treatment. The 10-year cumulative local recurrence remains high despite current management.
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| 10. |
- Marinkovic, I., et al.
(författare)
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A basic MRI anatomy of the rat brain in coronal sections for practical guidance to neuroscientists
- 2020
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Ingår i: Brain Research. - : Elsevier BV. - 0006-8993. ; 1747
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Tidskriftsartikel (refereegranskat)abstract
- Identification of the brain structures in the magnetic resonance imaging (MRI) of the rat is very important for the experimental work of many neuroscientists. Our intention was to recognize most of the structures without overlapping the MRI sections with the histological templates. Three live rats were used for this study who were examined in a micro-MRI apparatus by performing T2-weighted sequences in serial brain sections. Most of the white matter structures were easily identified, e.g. the anterior commissure, corpus callosum with forceps minor and major, cingulum, external and internal capsules, fornix, stria medullaris and terminalis, cranial nerves, mammillothalamic tract, fasciculus retroflexus, medial and lateral lemniscus, posterior commissure, commissures of the superior and inferior colliculi, medial longitudinal fasciculus, and the cerebral peduncle. Large and small gray matter structures were recognized as well, for example, the anterior olfactory structures, nucleus accumbens, caudate putamen, claustrum, bed nucleus of the stria terminalis, pituitary gland, globus pallidus, amygdala, some midline and intralaminar thalamic nuclei, certain hypothalamic nuclei, hippocampal formation, pineal body, periaqueductal gray matter, lateral and medial geniculate bodies, superior and inferior colliculi, and cranial nerves nuclei. All in all, of the total 160 recognized brain structures, 77 were identified without using the corresponding histological atlases. We believe that our labeled MRI pictures could be an important way for quick orientation for evaluating the effects of the experimental work regarding the rat brain.
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