Study of Microscopic Residual Stresses in an Extruded Aluminium Alloy Sample after Thermal Treatment

Abstract: A method is proposed to calculate the microscopic residual stresses in extruded cylindrical samples of non-ageing aluminium alloy 5083 (Al–Mg), arising from quenching in fresh water from 530°C. We start from the premise that the alloy is single-phase and non-isotropic on a microscopic scale; it consists of many grains that exhibit different mechanical response depending on their crystallographic orientation and neighboring grains. Microscopic residual stresses depend on the applied heat treatment, microstructure and mechanical strength of the individual grains. The stresses were calculated from neutron diffraction data. Genetic programming algorithms were used to calculate microscopic residual stresses, considering that each diffraction peak describes the stress distribution of a group of grains having a certain orientation, size and environment. The algorithm assigns a stress value to each grain according to the distribution of the diffraction peaks and the microstructural parameters of these grains.This work was supported by the Madrid Regional Government-FEDER grant Y2018/NMT-4668 (Micro-Stress-MAP-CM) and the project MAT2017-83825-C4-1-R. We would also like to express our gratitude to FLNR-JINP for the beam time allocated on the FSD instrument, and to the HeuristicLab Software developers

Sh2-205: II. Its quiescent stellar formation activity

We present a study of active stellar forming regions in the environs of the HII region Sh2-205. The analysis is based on data obtained from point source catalogues and images extracted from 2MASS, MSX, and IRAS surveys. Complementary data are taken from CO survey. The identification of primary candidates to stellar formation activity is made following colour criteria and the correlation with molecular gas emission. A number of stellar formation tracer candidates are projected on two substructures of the HII region: SH148.83-0.67 and SH149.25-0.00. However, the lack of molecular gas related to these structures casts doubts on the nature of the sources. Additional infrared sources may be associated with the HI shell centered at (l,b) = (149\degr 0\arcmin, -1\degr 30\arcmin). The most striking active area was found in connection to the HII region LBN 148.11-0.45, where stellar formation candidates are projected onto molecular gas. The analytical model to the "collect and collapse" process shows that stellar formation activity could have been triggered by the expansion of this HII region.Comment: Accepted for publication in MNRAS, 10 pages, 5 figures, 5 table

Evolving Gaussian Process Kernels for Translation Editing Effort Estimation

In many Natural Language Processing problems the combination of machine learning and optimization techniques is essential. One of these problems is estimating the effort required to improve, under direct human supervision, a text that has been translated using a machine translation method. Recent developments in this area have shown that Gaussian Processes can be accurate for post-editing effort prediction. However, the Gaussian Process kernel has to be chosen in advance, and this choice in- fluences the quality of the prediction. In this paper, we propose a Genetic Programming algorithm to evolve kernels for Gaussian Processes. We show that the combination of evolutionary optimization and Gaussian Processes removes the need for a-priori specification of the kernel choice, and achieves predictions that, in many cases, outperform those obtained with fixed kernels.TIN2016-78365-

Candidate planetary nebulae in the IPHAS photometric catalogue

Original article can be found at: http://www.aanda.org/ Copyright European Southern Observatory. DOI: 10.1051/0004-6361/200912002Context. We have carried out a semi-automated search for planetary nebulae (PNe) in the INT photometric H-alpha survey (IPHAS) catalogue. We present the PN search and the list of selected candidates. We cross correlate the selected candidates with a number of existing infrared galactic surveys in order to gain further insight into the nature of the candidates. Spectroscopy of a subset of objects is used to estimate the number of PNe present in the entire candidate list. Aims. The overall aim of the IPHAS PN project is to carry out a deep census of PNe in the northern Galactic plane, an area where PN detections are clearly lacking. Methods. The PN search is carried out on the IPHAS photometric catalogue. The candidate selection is based on the IPHAS and 2MASS/UKIDSS colours of the objects and the final candidate selection is made visually. Results. From the original list of ~600 million IPHAS detections we have selected a total of 1005 objects. Of these, 224 are known objects, leaving us with 781 PN candidates. Based on the initial follow-up spectroscopy, we expect the list to include very young and proto-PNe in addition to genuine, normal PNe (~16%) and emission line objects other than PNe. We present additional criteria to select the most probable PN candidates from our candidate list.Peer reviewe

Globules and pillars seen in the [CII] 158 micron line with SOFIA

Molecular globules and pillars are spectacular features, found only in the interface region between a molecular cloud and an HII-region. Impacting Far-ultraviolet (FUV) radiation creates photon dominated regions (PDRs) on their surfaces that can be traced by typical cooling lines. With the GREAT receiver onboard SOFIA we mapped and spectrally resolved the [CII] 158 micron atomic fine-structure line and the highly excited 12CO J=11-10 molecular line from three objects in Cygnus X (a pillar, a globule, and a strong IRAS source). We focus here on the globule and compare our data with existing Spitzer data and recent Herschel Open-Time PACS data. Extended [CII] emission and more compact CO-emission was found in the globule. We ascribe this emission mainly to an internal PDR, created by a possibly embedded star-cluster with at least one early B-star. However, external PDR emission caused by the excitation by the Cyg OB2 association cannot be fully excluded. The velocity-resolved [CII] emission traces the emission of PDR surfaces, possible rotation of the globule, and high-velocity outflowing gas. The globule shows a velocity shift of ~2 km/s with respect to the expanding HII-region, which can be understood as the residual turbulence of the molecular cloud from which the globule arose. This scenario is compatible with recent numerical simulations that emphazise the effect of turbulence. It is remarkable that an isolated globule shows these strong dynamical features traced by the [CII]-line, but it demands more observational studies to verify if there is indeed an embedded cluster of B-stars.Comment: Letter accepted by A&A (SOFIA special issue

A SINFONI view of flies in the Spiderweb: a galaxy cluster in the making

The environment of the high-z radio galaxy PKS 1138-262 at z~2.2 is a prime example of a forming galaxy cluster. We use deep SINFONI data to perform a detailed study of the kinematics of the galaxies within 60 kpc of the radio core and we link this to the kinematics of the protocluster on the megaparsec scale. Identification of optical emission lines shows that 11 galaxies are at the redshift of the protocluster. The density of line emitters is more than an order of magnitude higher in the core of the protocluster than the larger scale environment. This implies a matter overdensity in the core of delta_m~70 which is similar to the outskirts of local galaxy clusters. The velocity distribution of the confirmed satellite galaxies shows a broad, double-peaked velocity structure with sigma=1360+/-206 km/s. A similar broad, double-peaked distribution was found in a previous study targeting the large scale protocluster structure, indicating that a common process is acting on both small and large scales. Including all spectroscopically confirmed protocluster galaxies, a velocity dispersion of 1013+/-87 km/s is found. We show that the protocluster has likely decoupled from the Hubble flow and is a dynamically evolved structure. Comparison to the Millenium simulation indicates that the protocluster velocity distribution is consistent with that of the most massive haloes at z~2, but we rule out that the protocluster is a fully virialized structure based on dynamical arguments and its X-ray luminosity. Comparison to merging haloes in the Millennium simulation shows that the structure as observed in and around the Spiderweb galaxy is best interpreted as being the result of a merger between two massive haloes. We propose that this merger can result in an increase in star formation and AGN activity in the protocluster core and is possibly an important stage in the evolution of massive cD galaxies.Comment: 12 pages, 7 figures. Accepted for publication in MNRA

Alessi 95 and the short period Cepheid SU Cassiopeiae

The parameters for the newly-discovered open cluster Alessi 95 are established on the basis of available photometric and spectroscopic data, in conjunction with new observations. Colour excesses for spectroscopically-observed B and A-type stars near SU Cas follow a reddening relation described by E(U-B)/E(B-V)=0.83+0.02*E(B-V), implying a value of R=Av/E(B-V)~2.8 for the associated dust. Alessi 95 has a mean reddening of E(B-V)_(B0)=0.35+-0.02 s.e., an intrinsic distance modulus of Vo-Mv=8.16+-0.04 s.e. (+-0.21 s.d.), d=429+-8 pc, and an estimated age of 10^8.2 yr from ZAMS fitting of available UBV, CCD BV, NOMAD, and 2MASS JHKs observations of cluster stars. SU Cas is a likely cluster member, with an inferred space reddening of E(B-V)=0.33+-0.02 and a luminosity of =-3.15+-0.07 s.e., consistent with overtone pulsation (P_FM=2.75 d), as also implied by the Cepheid's light curve parameters, rate of period increase, and Hipparcos parallaxes for cluster stars. There is excellent agreement of the distance estimates for SU Cas inferred from cluster ZAMS fitting, its pulsation parallax derived from the infrared surface brightness technique, and Hipparcos parallaxes, which all agree to within a few percent.Comment: Accepted for Publication (MNRAS

Trading-off Data Fit and Complexity in Training Gaussian Processes with Multiple Kernels

This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this recordLOD 2019: Fifth International Conference on Machine Learning, Optimization, and Data Science, 10-13 September 2019, Siena, ItalyGaussian processes (GPs) belong to a class of probabilistic techniques that have been successfully used in different domains of machine learning and optimization. They are popular because they provide uncertainties in predictions, which sets them apart from other modelling methods providing only point predictions. The uncertainty is particularly useful for decision making as we can gauge how reliable a prediction is. One of the fundamental challenges in using GPs is that the efficacy of a model is conferred by selecting an appropriate kernel and the associated hyperparameter values for a given problem. Furthermore, the training of GPs, that is optimizing the hyperparameters using a data set is traditionally performed using a cost function that is a weighted sum of data fit and model complexity, and the underlying trade-off is completely ignored. Addressing these challenges and shortcomings, in this article, we propose the following automated training scheme. Firstly, we use a weighted product of multiple kernels with a view to relieve the users from choosing an appropriate kernel for the problem at hand without any domain specific knowledge. Secondly, for the first time, we modify GP training by using a multi-objective optimizer to tune the hyperparameters and weights of multiple kernels and extract an approximation of the complete trade-off front between data-fit and model complexity. We then propose to use a novel solution selection strategy based on mean standardized log loss (MSLL) to select a solution from the estimated trade-off front and finalise training of a GP model. The results on three data sets and comparison with the standard approach clearly show the potential benefit of the proposed approach of using multi-objective optimization with multiple kernels.Natural Environment Research Council (NERC

ACCESS III: The Nature of Star Formation in the Shapley Supercluster

We present a joint analysis of panoramic Spitzer/MIPS mid-infrared and GALEX ultraviolet imaging of the Shapley supercluster at z=0.048. Combining this with spectra of 814 supercluster members and 1.4GHz radio continuum maps, this represents the largest complete census of star-formation (both obscured and unobscured) in local cluster galaxies to date, reaching SFRs~0.02Msun/yr. We take advantage of this comprehensive panchromatic dataset to perform a detailed analysis of the nature of star formation in cluster galaxies, using several quite independent diagnostics of the quantity and intensity of star formation to develop a coherent view of the types of star formation within cluster galaxies. We observe a robust bimodality in the infrared (f_24/f_K) galaxy colours, which we are able to identify as another manifestation of the broad split into star-forming spiral and passive elliptical galaxy populations seen in UV-optical surveys. This diagnostic also allows the identification of galaxies in the process of having their star formation quenched as the infrared analogue to the UV "green valley" population. The bulk of supercluster galaxies on the star-forming sequence have specific-SFRs consistent with local field specific-SFR-M* relations, and form a tight FIR-radio correlation confirming that their FIR emission is due to star formation. We show that 85% of the global SFR is quiescent star formation within spiral disks, as manifest by the observed sequence in the IRX-beta relation being significantly offset from the starburst relation of Kong et al. (2004), while their FIR-radio colours indicate dust heated by low-intensity star formation. Just 15% of the global SFR is due to nuclear starbursts. The vast majority of star formation seen in cluster galaxies comes from normal infalling spirals who have yet to be affected by the cluster environment.Comment: 17 pages, 9 figures. Accepted for publication in MNRA

Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: results of a phase II trial (AGMT MBC-6)

BACKGROUND: Bendamustine, a medication approved for the treatment of indolent non-Hodgkin lymphoma, has already shown anticancer activity in metastatic breast cancer (MBC). Here, we present the results of a phase II trial of bendamustine in combination with capecitabine in pre-treated patients with MBC. PATIENTS AND METHODS: AGMT MBC-6 is a multicentre, open-label, single-arm phase II study in HER2-negative MBC. All patients were pre-treated with anthracyclines and/or taxans and had measurable disease. Patients received per os 1000 mg/m(2) capecitabine twice daily on days 1 to 14 in combination with 80 mg/m(2) bendamustine intravenously on days 1 and 8 of a 3-week cycle for a maximum of eight cycles, followed by a capecitabine maintenance therapy. The primary endpoint was overall response rate (ORR). RESULTS: From September 2013 to May 2015, 40 patients were recruited in eight Austrian centres. The median age was 60 years (range 29-77). Twenty-five per cent of patients had triple-negative breast cancer (TNBC) and 93% showed visceral involvement. With 17 partial and one complete remission, ORR was 46%. Median progression-free survival (PFS) was 7.5 months [95% confidence interval (CI) 6.1-10.7]. The most common non-haematological adverse events (AEs) of grade 3 were hand-foot syndrome (13%), fatigue (10%), nausea (8%), and dyspnoea (8%). One grade 4 non-haematological AE (hepatic failure) and three grade 4 haematological AEs (neutropenia) were observed. One patient died of restrictive cardiomyopathy, in which a relationship to capecitabine cannot be excluded, but seems unlikely. CONCLUSION: The combination of capecitabine and bendamustine shows promising efficacy and moderate toxicity. Further evaluation of this drug combination is warranted.The clinical trial AGMT MBC-6 was registered at ClinicalTrials.gov, (https://clinicaltrials.gov/; identifier: NCT01891227)