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SciPy is an open source scientific computing library for the Python programming language. SciPy 1.0 was released in late 2017, about 16 years after the original version 0.1 release. SciPy has become a de facto standard for leveraging scientific algorithms in the Python programming language, with more than 600 unique code contributors, thousands of dependent packages, over 100,000 dependent repositories, and millions of downloads per year. This includes usage of SciPy in almost half of all machine learning projects on GitHub, and usage by high profile projects including LIGO gravitational wave analysis and creation of the first-ever image of a black hole (M87). The library includes functionality spanning clustering, Fourier transforms, integration, interpolation, file I/O, linear algebra, image processing, orthogonal distance regression, minimization algorithms, signal processing, sparse matrix handling, computational geometry, and statistics. In this work, we provide an overview of the capabilities and development practices of the SciPy library and highlight some recent technical developments., Comment: Article source data is available here: https://github.com/scipy/scipy-articles

Methods sections adopt a common practice of past-tense narrative using passive voice. Here, we discuss issues with current and historical writing conventions in materials science literature and propose a structured way to facilitate reproducibility, clarity, and machine readability.

4 pages; International audience; The giant magnetostriction observed in rare-earth transition-metal compounds such as Terfenol-D (Tb0.3Dy0.7Fe2) is commonly associated with the huge anisotropy of the 4f electron cloud. We report here the experimental observation of this phenomenon at the atomic scale, in amorphous matter. By using extended x-ray absorption fine structure spectroscopy in a differential mode, the bond strains resulting from the coupling between the anisotropic shape of the Tb 4f charge density and the environment crystalline electric field are measured. In a-TbFe2 we measure Fe-Fe and Fe-Tb bond contractions equal to 6(1)x10−4 Å and of 9(2) x10−4 Å, respectively. These are the smallest atomic displacements ever detected in amorphous matter.

The structural changes exhibited by materials in response to their surroundings is of fundamental importance across countless disciplines in science and engineering. In the field of transducer technologies, strain-inducing phenomena (such as magnetostriction) are utilised in their own right, and form the physical foundation for sensor and actuator devices. Knowledge of their origin, and how they manifest themselves in different materials, underpins the development of new transducers and the optimisation of existing technologies. Yet in spite of this, direct measurement of a material’s intrinsic magnetostriction – the strain induced between individual atoms at a microscopic level – has proven elusive. This has essentially been due to the difficulty in measuring atomic motion with sufficient precision. In most materials, magnetostrictive atomic displacements saturate at just a few femtometres. Here, even sensitive atomic probes, such as x-ray absorption spectroscopy (XAS), lack the resolution to observe this motion by some two orders of magnitude. As a result, common experiments employ strain gauges on macroscopic samples, where the strain is easier to detect, but where atomic information is lost. However, with the recent development of differential XAS (DiffXAS) at the European Synchrotron Radiation Facility (ESRF), such atomic-scale measurements have become possible [1,2]. Initial studies into the magnetostriction of FeCo thin films demonstrated a sensitivity to femtometre scale motion [1]. Subsequent work extended this study to investigate the magnetoelastic coupling of FeCo under applied hydrostatic pressure [3], and new experiments looked into the behaviour of FePt, and rare-earth iron alloys such as Fe2Tb. But the most significant study conducted to date has been that of the Fe-Ga system [4,5]. In recent years, binary metal alloys such as Fe-Al or Fe-Ga, have attracted considerable interest [6]. It is well known that pure Fe exhibits only an extremely small magnetostriction, but when alloyed with certain nonmagnetic metallic elements, it can be enhanced by over an order of magnitude. Compositions of Fe-Ga with around 19at% Ga have reported strains of up to 400 ppm [7]. Although this doesn’t constitute a truly ‘giant’ magnetostriction, it is of interest for device applications since Fe-Ga is devoid of expensive rare-earth components, saturates in fields of only several hundred Oersteds, and possesses more desirable mechanical properties than, say, the much studied Terfenol-D alloy. In order to identify the origin of this enhancement, we took a splat-cooled foil of Fe81Ga19 and measured its Joule saturation magnetostriction with DiffXAS [4]. Unlike conventional macroscopic measurements that describe the sample as a whole, magnetostriction coefficients provided by DiffXAS describe the strain of just the first two or three atomic coordination shells surrounding a photo-excited atom. Furthermore, since it is possible to tune the x-ray energy, and so select which atom in the material is excited, it is possible to look at the strain in the local environment of each atomic species separately. Contributions from different types of bond within the structure may then be decoupled and analysed. Such fundamental information has immense value when attempting to verify theoretical models. In 2002, Wu [8] proposed a model for the magnetostriction of FexGa(1-x) that suggested a tetragonal “B2-like” structure in the vicinity of the Ga atoms was responsible for the observed enhancement. More recently, Cullen et al. [9] reached a similar conclusion, and stated that such a structure could be formed by Ga pairs randomly arranged throughout the material. Conventional XAS studies have confirmed the presence of these Ga pairs [5], but it is DiffXAS that describes how they influence the magnetostriction. From our DiffXAS spectra, we extracted the strain present in different types of bond, and with a subsequent analysis, solved the magnetostriction tensor for the material. This provided two sets of magnetostriction coefficients. In the environment around Fe, (3/2)100 = 40ppm and (3/2)111 = -32ppm, and in the environment around Ga, (3/2)100 = 390ppm and (3/2)111 ~0ppm. This demonstrates that the observed enhancement is dominated by strain in the vicinity of the Ga atoms. Furthermore, our analysis revealed that the strain in the Ga pairs was negligible, indicating that they do not contribute directly to the enhanced magnetostriction, but rather mediate the enhancement in the surrounding Ga-Fe bonds. Further experiments are planned to examine the full range of compositions over which magnetostriction enhancement is observed in this system, and, with the use of single crystal samples, investigate how the microscopic magnetostriction scales up to that seen macroscopically. [1] R.F. Pettifer, O. Mathon, S. Pascarelli, M.D. Cooke, M.R. J. Gibbs, Nature 435, 79 (2005) [2] M. P. Ruffoni, R.F. Pettifer, S. Pascarelli et al., AIP Conf. Proc. No. 882, 838 (2007) [3] S. Pascarelli, M. P. Ruffoni, A. Trapananti et al., Phys. Rev. Lett. 99, 237204 (2007) [4] M. P. Ruffoni, S. Pascarelli, R. Grössinger et al., Phys. Rev. Lett. 101, 147202 (2008) [5] S. Pascarelli, M. P. Ruffoni, R. Sato-Turtelli et al., Phys. Rev. B 77, 184406 (2008) [6] E. M. Summers, T. A. Lograsso, M. Wun-Fogle, J. Mater. Sci. 42, 9582 (2007) [7] A. E. Clark, A. B. Hathaway, M. Wun-Fogle et al., J. Appl. Phys. 93, 8621 (2003) [8] R. Wu, J. Appl. Phys. 91, 7358 (2002) [9] J. Cullen, P. Zhao, M. Wuttig, J. Appl. Phys. 101, 123922 (2007) Submitted version

A random sample of 177 individuals from the Italian population was typed for eight HLA-DR antigens. Gene frequencies and linkage disequilibria were calculated. The most different frequencies, when compared with other european populations, are those of DR5 and DRw6. Most of the linkage disequilibria observed are the same found in other european populations, but some disequilibria present only in Italian population were also observed.

Human histocompatibility (HLA) gene frequencies were studied in the Italian population. A random sample of healthy individuals born in several Italian regions and provinces was studied to estimate HLA-A, -B, -C and -DR gene frequencies using the maximum likelihood method. The goodness of fit to Hardy-Weinberg proportions was evaluated by the likelihood ratio statistics. Different Italian regions and provinces show significant differences in the HLA alleles, providing further evidence for the genetic heterogeneity in the Italian population. This heterogeneity is also displayed by a synthetic geographical representation which uses colour to map the most informative gene differences. Statistically significant gametic associations between HLA-A, -B, -C and -DR loci are reported. The difference between northern and southern Italy and between continental Italy and Sardegna is clearly shown also by their heterogeneous linkage disequilibria.

Barium hexaferrites are well-known materials suitable for a variety of applications. In this contribution we present the possibility of applying spraying technologies in the preparation of electromagnetic absorbers based on barium hexaferrites. Thick barium hexaferrite coatings with the compositions BaFel2019 and BaCoTiFelOOl9were deposited by high-velocity oxygen-fuel (HVOF) and atmospheric plasma-spraying (APS) technologies. The coatings were prepared from pre-reacted powders of the desired composition. The crystallization of the hexaferrites was studied by X-ray powder diffractometry, electron microscopy, including microanalysis, which was also combined with thermal analyses and magnetic measurements. The as-deposited coatings were poorly crystallized because of the phase changes induced in the powders "in-flight" in the HVOF and the APS flames and during their quenchingwhile fonning the coating. The coatings produced by APS showed a higher crystallinity than those prepared with HVOF. The largest amount of the hexaferrite phase was obtained in the APS-sprayed BaCoTiFelOOl9coating. In general, the crystallinity of the coatings and their magnetic properties were improved by a subsequent annealing. Fig. I and Table 1 are presented as examples of the annealing studies. Fig. 1 shows the crystallization of the BaCoTiFelOOl9produced by APS followed by annealing. The evolution of the magnetic properties; of the BaFe12019prepared with HVOF depending on the annealing temperatures is presented in Table 1. Similar results were also achieved for the other coatings. Single-phase hexaferrite coatings were obtained at 900°C or at 1000°C, depending on the chemical composition and on the spraying technology. The absorption characteristics were calculated from the electromagnetic properties measured· at 0.4-60 GHz. For tile BaFe12019coatings with thicknesses of 0.15-0.4 mm an enhanced absorption was predicted for mm-waves, while for the BaCoTiFelOOl9coatings with thicknesses of 1-4 mm, enhanced absorption was predicted for microwaves.

A wide data collection on blood group gene frequencies in Italian regions and provinces is presented. This report is the result of a joint collaboration of human geneticists and forensic haematologists started in 1979 and updates a previous work by the same group. The following genetic polymorphisms have been examined: red-cell antigens (ABO, FY, Kell, Kidd, Lewis, Lutheran, MNSs, P, Rhesus), red-cell enzymes (ACP1, ADA, AK1, ESD, GLO1, GPT, PGD, PGM1), plasma proteins (BF, C3, GC, HP, IGK, PI, TF). Data have been classified according to genetic systems, Italian regions and provinces. Gene frequencies were estimated by the maximum likelihood method. The goodness of fit to Hardy-Weinberg proportions has been evaluated by the likelihood ratio statistics. Genetic heterogeneity of provinces and regions is reported.

As one quarter of global energy use serves the production of materials, the more efficient use of these materials presents a significant opportunity for the mitigation of greenhouse gas (GHG) emissions. With the renewed interest of policy makers in the circular economy, material efficiency (ME) strategies such as light-weighting and downsizing of and lifetime extension for products, reuse and recycling of materials, and appropriate material choice are being promoted. Yet, the emissions savings from ME remain poorly understood, owing in part to the multitude of material uses and diversity of circumstances and in part to a lack of analytical effort. We have reviewed emissions reductions from ME strategies applied to buildings, cars, and electronics. We find that there can be a systematic trade-off between material use in the production of buildings, vehicles, and appliances and energy use in their operation, requiring a careful life cycle assessment of ME strategies. We find that the largest potential emission reductions quantified in the literature result from more intensive use of and lifetime extension for buildings and the light-weighting and reduced size of vehicles. Replacing metals and concrete with timber in construction can result in significant GHG benefits, but trade-offs and limitations to the potential supply of timber need to be recognized. Repair and remanufacturing of products can also result in emission reductions, which have been quantified only on a case-by-case basis and are difficult to generalize. The recovery of steel, aluminum, and copper from building demolition waste and the end-of-life vehicles and appliances already results in the recycling of base metals, which achieves significant emission reductions. Higher collection rates, sorting efficiencies, and the alloy-specific sorting of metals to preserve the function of alloying elements while avoiding the contamination of base metals are important steps to further reduce emissions.

The environmental life cycle impacts of conceptual rare earth production processes were assessed. An average greenhouse gas emission of 65.4 kg CO2e/kg was estimated for the 15 rare earths produced from monazite, ranging from 21.3 kg CO2e/kg for europium to 197.9 kg CO2e/kg for yttrium. The average water consumption of rare earth production was 11,170 kg/kg ranging from 3,803 kg/kg for samarium and gadolinium to 29,902 kg/kg for yttrium. The average gross energy requirement for production was 917 MJ/kg, ranging from 311 MJ/kg for samarium and gadolinium to 3,401 MJ/kg for yttrium. Given the low concentration of HREE in monazite, the high impacts across all categories for yttrium and other HREE are not necessarily representative of HREE sourced from all rare earth resources. Further studies into other rare earth mineral resources (e.g. bastnasite and xenotime) are recommended to improve the overall understanding of environmental impacts from rare earth production.

International audience; Bricks, fine pottery, ceramic gears and tiles are among the human-made objects routinely recovered in archaeological documentation. Sites associated with early civilizations can provide thousands of samples from a single excavation. They come in endless varieties according to economic and social circumstances and, as debris can last almost forever, provide important clues about the past behaviours in human societies. Any information about the provenance of ceramics is highly valuable in archaeological analysis. In the case of Roman brick-making, the provenance and manufacture of clayey materials are usually interpreted only by studying stamps imprinted on the artefacts, when available. In this paper, the making of bricks, tiles and other ceramics for building purposes is investigated, in relation to the possible sources of raw materials used for the industry. The major questions to be solved relate to the sites from where the Romans collected the raw materials, the technologies they applied to make bricks and other clayey building materials, and how far have they transported raw resources and final products - i.e. mainly bricks and tiles - after furnace treatments, considering that a crucial point was the nearby availability of timber, water, and sandy soils without stones. Some achievements to classify artefacts with identical provenance have been obtained, using the structural transformations induced in the material by thermal treatments of pottery. Comparisons have been made of the trace elements chemical composition in ICP-MS and some physical properties, including magnetic, VSM hysteresis loops, and mineralogical features with XRD and IR analysis, have been identified as proxies to elucidate the possible provenance of rough materials, and appreciate the technologies used by the Roman brick-making industry.

The distribution of atrial electrogram types has been proposed to characterise human atrial fibrillation. The aim of this study was to provide computer procedures for evaluating the local organisation of intracardiac recordings during AF as an alternative to off-line manual classification. Principal components analysis (PCA) reduced the data set to a few representative activations, and cluster analysis (CA) measured the average dissimilarity between consecutive activations of an intracardiac signal. The data set consisted of 106 bipolar signals recorded on 11 patients during electrophysiological studies for catheter ablation. Performances of PCA and CA in distinguishing between organised (type I) and disorganised (type II/III, Wells criteria) were assessed, in comparison with manual reading, by evaluating the predictive parameters of the classification analysis. Both methods gave high accuracy (92% for PCA and 89% for CA), confirming the feasibility of on-line characterisation of AF. Sensitivity was lower than specificity (81% against 98% for PCA, and 77% against 97% for CA), with seven out of eight misclassifications of PCA in common with CA. Differences between manual and computer analysis may be related to the higher resolution of PCA and CA in the measurement of the organisation of atrial activations. These procedures are suitable for providing automatic (by CA) or semi-automatic (by PCA) measures of the extent of local organisation of AF in the pre-ablation treatment phase.

We investigate the chemical, electronic, and magnetic structure of the magnetocaloric LaFeCoSi compound with bulk and surface sensitive techniques. We put in evidence that the surface retains a soft ferromagnetic behavior at temperatures higher than the Curie temperature of the bulk due to the presence of Fe clusters at the surface only. This peculiar magnetic surface effect is attributed to the exchange interaction between the ferromagnetic Fe clusters located at the surface and the bulk magnetocaloric alloy, and it is used here to monitor the magnetic properties of the alloy itself. (C) 2014 AIP Publishing LLC.

The rate of success of radio-frequency catheter ablation in the treatment of atrial fibrillation may be significantly improved by evaluating the local electrical properties of the atrial tissue. The aim of this study is the development of an automatic procedure for the characterisation of the local electrical activity during atrial fibrillation and the comparison of its performance with the manual analysis. The adopted procedures were the semi-automatic measurement of the local fibrillation intervals (A-A intervals) and the manual electrogram classification following the criteria suggested by Wells (1978) or Konings (1997). Two methods have been used: Principal Component Analysis and Cluster Analysis. Cross-validation of automatic results with manual analysis (percentage of type I activations in 90 sec) gives nearly 90% of accuracy for both methods. A larger database is needed to improve the clinical value of the authors' approach.