Model Based Capability Assessment of an Automated Eddy Current Inspection Procedure on Flat Surfaces

The probability of detection (POD) of a well-controlled, automated eddy current (EC) procedure is evaluated in a numerical model and compared with experiments. The procedure is applied in laboratory environment with a single absolute probe which is positioned for raster scan over flat surfaces containing fatigue cracks. The variability of the signal amplitude, due to small fatigue cracks in the Titanium alloy Ti-6Al-4 V, is expected to mainly originate from crack characteristics and the index distance of the raster scan. The POD model is based on the signal versus crack size ( versus a) result. The presented procedure provides a well-defined basis for a comparison between a simulated and an experimentally based POD assessment. Finite element analysis is used to model the EC method. A simplified fatigue crack model is first introduced and evaluated experimentally. Numerical computations are then used to build the corresponding model-based POD curve which shows good agreement with the experimental result. The model-based POD curve is generated both by means of a parametric and a nonparametric approach. Differences between model-based and experimental POD are discussed as well as the delta POD approach using transfer functions

Recent survey and application of the simSUNDT software

The simSUNDT software is based on a previous developed program (SUNDT). The latest version has been customized in order to generate realistic synthetic data (including a grain noise model), compatible with a number of off-line analysis software. The software consists of a Windows®-based preprocessor and postprocessor together with a mathematical kernel (UTDefect), dealing with the actual mathematical modeling. The model employs various integral transforms and integral equation and enables simulations of the entire ultrasonic testing situation. The model is completely three-dimensional though the simulated component is two-dimensional, bounded by the scanning surface and a planar back surface as an option. It is of great importance that inspection methods that are applied are proper validated and that their capability of detection of cracks and defects are quantified. In order to achieve this, statistical methods such as Probability of Detection (POD) often are applied, with the ambition to estimate the detectability as a function of defect size. Despite the fact that the proposed procedure with the utilization of test pieces is very expensive, it also tends to introduce a number of possible misalignments between the actual NDT situation that is to be performed and the proposed experimental simulation. The presentation will describe the developed model that will enable simulation of a phased array NDT inspection and the ambition to use this simulation software to generate POD information. The paper also includes the most recent developments of the model including some initial experimental validation of the phased array probe model. © 2010 American Institute of Physics

POD GENERATED BY MONTE CARLO SIMULATION USING A META-MODEL BASED ON THE simSUNDT SOFTWARE

A recent developed numerical procedure for simulation of POD is used to identify the most influential parameters and test the effect of their interaction and variability with different statistical distributions. With a multi-parameter prediction model, based on the NDT simulation software simSUNDT, a qualified ultrasonic procedure of personnel within Swedish nuclear power plants is investigated. The stochastical computations are compared to experimentally based POD and conclusions are drawn for both fatigue and stress corrosion cracks

Comparison between three mathematical models of three well defined ultrasonic NDT cases

Ultrasonic nondestructive testing (NDT) is commonly used for in-service inspection in different areas. But reliability of NDT method is highly dependent on the equipment and crack features. Although, it is possible to use thoroughly validated mathematical models to avoid complicated and costly experimental work, when it is necessary to qualify new procedures. Finite Element Model (FEM) is a powerful tool, which is commonly used for such cases. In this paper three mathematical models of three well defined cases will be compared with each other

Case depth evaluation of induction-hardened camshaft by using magnetic Barkhausen noise (MBN) method

Magnetic Barkhausen noise (MBN) method is one of the non-destructive\ua0evaluating (NDE) techniques used in industry to monitor the quality of ferromagnetic products during manufacture. In this article, case depth evaluation of the camshaft lobes by this means after induction hardening is described. A\ua0routine industrial monitoring practice is found to have limitation to evaluate the thickness of this process-hardened\ua0layer. With the aid of metallography on selected samples, this uppermost layer is found to have one, or more than one microconstituents. This infers that each type possesses different physical properties in response to the MBN measurement. Consequently, the interpretation of the MBN signal/data for case depth evaluation is not straight-forward.\ua0From metallography, a\ua0qualified component should have a\ua0uniform layer of martensite with grains ≤ 50\ua0\ub5m and the thickness around\ua03.0–5.0\ua0mm. This gives the magnetoelastic parameter (i.e. mp) in a\ua0range of\ua020–70 in industrial MBN measurement. The mp outside this range corresponds to either a\ua0non-martensitic\ua0type or a\ua0martensitic type with grains > 50\ua0\ub5m. In fact, the characteristic features of a\ua0Barkhausen burst like peak intensity, width and position can be used to categorise different microstructural conditions. Then, the case depth of the qualified components, or the thickness of the qualified martensite, can be estimated. Statistical regression decision tree model helps to divide this qualified group into three sub-groups\ua0between 3.0 and\ua06.0\ua0mm, and each can be identified by the decision criteria based on the specific ranges of the mp reading, the RMS of peak intensity and the peak position. In the end, a\ua0physical model is used to show how the difference of microstructures is influencing the magnetic flux, and thus the mp. Nevertheless, more information is needed to improve the model for this application.

Rehabilitation provided to patients with rheumatoid arthritis: A comparison of three different rheumatology clinics in Austria, Sweden and the UK from the perspectives of patients and health professionals

© 2015 The Authors. © 2015 Foundation of Rehabilitation Information. Objective: To explore patients' and health professionals' views of outpatient rehabilitation services for patients with rheumatoid arthritis in 3 different rheumatology sites across Europe. Methods: A qualitative multi-method study was conducted with patients and health professionals in Vienna (Austria), Gothenburg (Sweden) and Leeds (UK). Data collection was carried out during focus groups with patients and health professionals. Patients' hospital records were integrated into the analysis. Data were analysed for site and findings were compared across sites. Results: A total of 20 patients and 20 health professionals participated in 12 focus groups. Although the 3 sites were all publicly funded university clinics, there were differences between sites regarding the structure and content of rehabilitation services. The themes that emerged in the focus groups were: referrals; continuity in rehabilitation; information provided to patients; patients' organizations; documentation and communication amongst health professionals; interface between primary and specialist care; and prescription practices. Most themes were addressed at all 3 sites, but there were variations in the specifics within themes. Conclusion: Integration of patients' and health professionals' views on how rehabilitation services are coordinated and how (parts of) processes are set up elsewhere provide valuable information for the further optimization of rehabilitation services

The transcription factor Zeb2 regulates development of conventional and plasmacytoid DCs by repressing Id2

Plasmacytoid dendritic cells (DCs [pDCs]) develop from pre-pDCs, whereas two lineages of conventional DCs (cDCs; cDC1s and cDC2s) develop from lineage-committed pre-cDCs. Several transcription factors (TFs) have been implicated in regulating the development of pDCs (E2-2 and Id2) and cDC1s (Irf8, Id2, and Batf3); however, those required for the early commitment of pre-cDCs toward the cDC2 lineage are unknown. Here, we identify the TF zinc finger E box-binding homeobox 2 (Zeb2) to play a crucial role in regulating DC development. Zeb2 was expressed from the pre-pDC and pre-cDC stage onward and highly expressed in mature pDCs and cDC2s. Mice conditionally lacking Zeb2 in CD11c(+) cells had a cell-intrinsic reduction in pDCs and cDC2s, coupled with an increase in cDC1s. Conversely, mice in which CD11c(+) cells overexpressed Zeb2 displayed a reduction in cDC1s. This was accompanied by altered expression of Id2, which was up-regulated in cDC2s and pDCs from conditional knock-out mice. Zeb2 chromatin immunoprecipitation analysis revealed Id2 to be a direct target of Zeb2. Thus, we conclude that Zeb2 regulates commitment to both the cDC2 and pDC lineages through repression of Id2

Emergence of fractal geometries in the evolution of a metabolic enzyme

Fractals are patterns that are self-similar across multiple length-scales. Macroscopic fractals are common in nature; however, so far, molecular assembly into fractals is restricted to synthetic systems. Here we report the discovery of a natural protein, citrate synthase from the cyanobacterium Synechococcus elongatus, which self-assembles into Sierpiński triangles. Using cryo-electron microscopy, we reveal how the fractal assembles from a hexameric building block. Although different stimuli modulate the formation of fractal complexes and these complexes can regulate the enzymatic activity of citrate synthase in vitro, the fractal may not serve a physiological function in vivo. We use ancestral sequence reconstruction to retrace how the citrate synthase fractal evolved from non-fractal precursors, and the results suggest it may have emerged as a harmless evolutionary accident. Our findings expand the space of possible protein complexes and demonstrate that intricate and regulatable assemblies can evolve in a single substitution

Is it possible to assess the effects of dynamic arm supports on upper extremity range of motion during activities of daily living in the domestic setting using a portable motion capturing device? - A pilot study

BACKGROUND: Understanding how dynamic arm supports affect the ability to perform activities of daily living (ADL) in daily life situations is essential for improved prescription. OBJECTIVE: To determine whether the newly developed MMAAS is a useful tool to assess the RoM at home. Secondly, to investigate differences in RoM and ADL performance with and without dynamic arm support. METHODS: Five dynamic arm support users performed nine activities with and without dynamic arm support at home. A reference group of five participants was included. Shoulder and elbow RoM were assessed for the three most difficult tasks. RESULTS: The measurement of the elbow joint RoM appeared unreliable. In most participants shoulder RoM increased with dynamic arm support, but the magnitude of change differed. Variation was also found regarding whether people could perform ADL with and without support. CONCLUSIONS: In its current state the MMAAS is not regarded a useful tool for assessing the RoM in the domestic setting. The ability to perform ADL and RoM seem influenced by the environment, users' needs and abilities. Future studies investigating effects and benefits of dynamic arm supports should be conducted in a broader daily life context

Select strengths and biases of models in representing the Arctic winter boundary layer over sea ice: the Larcform 1 single column model intercomparison

Weather and climate models struggle to represent lower tropospheric temperature and moisture profiles and surface fluxes in Arctic winter, partly because they lack or misrepresent physical processes that are specific to high latitudes. Observations have revealed two preferred states of the Arctic winter boundary layer. In the cloudy state, cloud liquid water limits surface radiative cooling, and temperature inversions are weak and elevated. In the radiatively clear state, strong surface radiative cooling leads to the build-up of surface-based temperature inversions. Many large-scale models lack the cloudy state, and some substantially underestimate inversion strength in the clear state. Here, the transformation from a moist to a cold dry air mass is modeled using an idealized Lagrangian perspective. The trajectory includes both boundary layer states, and the single-column experiment is the first Lagrangian Arctic air formation experiment (Larcform 1) organized within GEWEX GASS (Global atmospheric system studies). The intercomparison reproduces the typical biases of large-scale models: some models lack the cloudy state of the boundary layer due to the representation of mixed-phase microphysics or to the interaction between micro- and macrophysics. In some models, high emissivities of ice clouds or the lack of an insulating snow layer prevent the build-up of surface-based inversions in the radiatively clear state. Models substantially disagree on the amount of cloud liquid water in the cloudy state and on turbulent heat fluxes under clear skies. Observations of air mass transformations including both boundary layer states would allow for a tighter constraint of model behavior