Automated Analysis of Time-resolved X-ray data using Optical Flow Methods

We develop a general-purpose framework for analysis of time-resolved X-ray data based on optical flow. We perform a systematic evaluation of state-of-the-art optical flow techniques and their components. On the top of motion estimation we provide an extensive data analysis toolkit. All the devised techniques can be applied in 4D (3D + time). The implementation employs advanced numerical schemes and computations on GPU. We present the application of the optical flow methods to a number of scientific problems from various research fields

Mixing instabilities during shearing of metals

Severe plastic deformation of solids is relevant to many materials processing techniques as well as tribological events such as wear. It results in microstructural refinement, redistribution of phases, and ultimately even mixing. However, mostly due to inability to experimentally capture the dynamics of deformation, the underlying physical mechanisms remain elusive. Here, we introduce a strategy that reveals details of morphological evolution upon shearing up to ultrahigh strains. Our experiments on metallic multilayers find that mechanically stronger layers either fold in a quasi-regular manner and subsequently evolve into periodic vortices, or delaminate into finer layers before mixing takes place. Numerical simulations performed by treating the phases as nonlinear viscous fluids reproduce the experimental findings and reveal the origin for emergence of a wealth of morphologies in deforming solids. They show that the same instability that causes kilometer-thick rock layers to fold on geological timescales is acting here at micrometer level

Zoning methodology for estimating the service life of the vehicle

The article presents a comprehensive method for removing uncertainty when solving multicriteria problems of vehicle maintenance. The task of the control system for the service life of the car is formed, and its characteristics are also highlighted. The main provisions of the zoning method are formulated from the point of view of the hierarchical correlation of the probabilities of the state of the external environment. The dynamics of changes in the quality indicators of cars in a multicriteria setting is estimated

Methods of systemic management of the service life of vehicles

The article discusses the methods of multi-criteria assessment of the efficiency of vehicle operation according to their properties. The main difficulties in solving the issue of technical operation of vehicles when introducing these methods into the assessment process are highlighted. Algorithms of decision-making related to the choice of a vehicle in conditions of uncertainty of the external environment are analyzed. Their advantages and disadvantages are substantiated. A methodology for calculating weight coefficients for the optimization and development of the transport system is proposed

Development of an Array of Compound Refractive Lenses for Sub-Pixel Resolution, Large Field of View, and Time-Saving in Scanning Hard X-ray Microscopy

A two-dimensional array of compound refractive lenses (2D array of CRLs) designed for hard X-ray imaging with a 3.5 mm$^{2}$ large field of view is presented. The array of CRLs consists of 2D polymer biconcave parabolic 34 × 34 multi-lenses fabricated via deep X-ray lithography. The developed refractive multi-lens array was applied for sub-pixel resolution scanning transmission X–ray microscopy; a raster scan with only 55 × 55 steps provides a 3.5 megapixel image. The optical element was experimentally characterized at the Diamond Light Source at 34 keV. An array of point foci with a 55 µm period and an average size of ca. 2.1 µm × 3.6 µm was achieved. In comparison with the conventional scanning transmission microscopy using one CRL, sub-pixel resolution scanning transmission hard X-ray microscopy enables a large field of view and short scanning time while keeping the high spatial resolution

Interpr\'etation de l'Arithm\'etique dans certains groupes de permutations affines par morceaux d'un intervalle

The Arithmetic is interpreted in all the groups of Richard Thompson and Graham Higman, as well as in other groups of piecewise affine permutations of an interval which generalize the groups of Thompson and Higman. In particular, the elementary theories of all these groups are undecidable. Moreover, Thompson's group $F$ and some of its generalizations interpret the Arithmetic without parameters.Comment: v3: French, 29 pages, 3 figures, minor corrections; v2: 29 pages, 3 figures, corrections, added references, no essential changes; v1: 28 pages, 3 figure

Parameterized Picard-Vessiot extensions and Atiyah extensions

Generalizing Atiyah extensions, we introduce and study differential abelian tensor categories over differential rings. By a differential ring, we mean a commutative ring with an action of a Lie ring by derivations. In particular, these derivations act on a differential category. A differential Tannakian theory is developed. The main application is to the Galois theory of linear differential equations with parameters. Namely, we show the existence of a parameterized Picard-Vessiot extension and, therefore, the Galois correspondence for many differential fields with, possibly, non-differentially closed fields of constants, that is, fields of functions of parameters. Other applications include a substantially simplified test for a system of linear differential equations with parameters to be isomonodromic, which will appear in a separate paper. This application is based on differential categories developed in the present paper, and not just differential algebraic groups and their representations.Comment: 90 pages, minor correction

Efficiency of Finding Muon Track Trigger Primitives in CMS Cathode Strip Chambers

In the CMS Experiment, muon detection in the forward direction is accomplished by cathode strip chambers~(CSC). These detectors identify muons, provide a fast muon trigger, and give a precise measurement of the muon trajectory. There are 468 six-plane CSCs in the system. The efficiency of finding muon trigger primitives (muon track segments) was studied using~36 CMS CSCs and cosmic ray muons during the Magnet Test and Cosmic Challenge~(MTCC) exercise conducted by the~CMS experiment in~2006. In contrast to earlier studies that used muon beams to illuminate a very small chamber area ($< \! 0.01$~m$^2$), results presented in this paper were obtained by many installed CSCs operating {\em in situ} over an area of $\approx \! 23$~m$^2$ as a part of the~CMS experiment. The efficiency of finding 2-dimensional trigger primitives within 6-layer chambers was found to be~$99.93 \pm 0.03\%$. These segments, found by the CSC electronics within $800$~ns after the passing of a muon through the chambers, are the input information for the Level-1 muon trigger and, also, are a necessary condition for chambers to be read out by the Data Acquisition System

Zu den Wurzeln der Modernen Architektur, Teil I

Modern emerging technologies, such as additive manufacturing, bioprinting, and new material production, require novel metrology tools to probe fundamental high-speed dynamics happening in such systems. Here we demonstrate the application of the megahertz (MHz) European X-ray Free-Electron Laser (EuXFEL) to image the fast stochastic processes induced by a laser on water-filled capillaries with micrometer-scale spatial resolution. The EuXFEL provides superior contrast and spatial resolution compared to equivalent state-of-the-art synchrotron experiments. This work opens up new possibilities for the characterization of MHz stochastic processes on the nanosecond to microsecond time scales with object velocities up to a few kilometers per second using XFEL sources

Design, Performance, and Calibration of the CMS Hadron-Outer Calorimeter

The CMS hadron calorimeter is a sampling calorimeter with brass absorber and plastic scintillator tiles with wavelength shifting fibres for carrying the light to the readout device. The barrel hadron calorimeter is complemented with an outer calorimeter to ensure high energy shower containment in the calorimeter. Fabrication, testing and calibration of the outer hadron calorimeter are carried out keeping in mind its importance in the energy measurement of jets in view of linearity and resolution. It will provide a net improvement in missing \et measurements at LHC energies. The outer hadron calorimeter will also be used for the muon trigger in coincidence with other muon chambers in CMS