WorldWideScience

Sample records for collection element shapes

  1. Adaptive finite element method for shape optimization

    KAUST Repository

    Morin, Pedro

    2012-01-16

    We examine shape optimization problems in the context of inexact sequential quadratic programming. Inexactness is a consequence of using adaptive finite element methods (AFEM) to approximate the state and adjoint equations (via the dual weighted residual method), update the boundary, and compute the geometric functional. We present a novel algorithm that equidistributes the errors due to shape optimization and discretization, thereby leading to coarse resolution in the early stages and fine resolution upon convergence, and thus optimizing the computational effort. We discuss the ability of the algorithm to detect whether or not geometric singularities such as corners are genuine to the problem or simply due to lack of resolution - a new paradigm in adaptivity. © EDP Sciences, SMAI, 2012.

  2. Emotional collectives: How groups shape emotions and emotions shape groups.

    Science.gov (United States)

    van Kleef, Gerben A; Fischer, Agneta H

    2016-01-01

    Group settings are epicentres of emotional activity. Yet, the role of emotions in groups is poorly understood. How do group-level phenomena shape group members' emotional experience and expression? How are emotional expressions recognised, interpreted and shared in group settings? And how do such expressions influence the emotions, cognitions and behaviours of fellow group members and outside observers? To answer these and other questions, we draw on relevant theoretical perspectives (e.g., intergroup emotions theory, social appraisal theory and emotions as social information theory) and recent empirical findings regarding the role of emotions in groups. We organise our review according to two overarching themes: how groups shape emotions and how emotions shape groups. We show how novel empirical approaches break important new ground in uncovering the role of emotions in groups. Research on emotional collectives is thriving and constitutes a key to understanding the social nature of emotions.

  3. Recurring part arrangements in shape collections

    KAUST Repository

    Zheng, Youyi

    2014-05-01

    Extracting semantically related parts across models remains challenging, especially without supervision. The common approach is to co-analyze a model collection, while assuming the existence of descriptive geometric features that can directly identify related parts. In the presence of large shape variations, common geometric features, however, are no longer sufficiently descriptive. In this paper, we explore an indirect top-down approach, where instead of part geometry, part arrangements extracted from each model are compared. The key observation is that while a direct comparison of part geometry can be ambiguous, part arrangements, being higher level structures, remain consistent, and hence can be used to discover latent commonalities among semantically related shapes. We show that our indirect analysis leads to the detection of recurring arrangements of parts, which are otherwise difficult to discover in a direct unsupervised setting. We evaluate our algorithm on ground truth datasets and report advantages over geometric similarity-based bottom-up co-segmentation algorithms. © 2014 The Author(s) Computer Graphics Forum © 2014 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  4. Emotional collectives : How groups shape emotions and emotions shape groups

    NARCIS (Netherlands)

    van Kleef, G.A.; Fischer, A.H.

    2016-01-01

    Group settings are epicentres of emotional activity. Yet, the role of emotions in groups is poorly understood. How do group-level phenomena shape group members’ emotional experience and expression? How are emotional expressions recognised, interpreted and shared in group settings? And how do such

  5. Exploration of continuous variability in collections of 3D shapes

    KAUST Repository

    Ovsjanikov, Maks

    2011-07-01

    As large public repositories of 3D shapes continue to grow, the amount of shape variability in such collections also increases, both in terms of the number of different classes of shapes, as well as the geometric variability of shapes within each class. While this gives users more choice for shape selection, it can be difficult to explore large collections and understand the range of variations amongst the shapes. Exploration is particularly challenging for public shape repositories, which are often only loosely tagged and contain neither point-based nor part-based correspondences. In this paper, we present a method for discovering and exploring continuous variability in a collection of 3D shapes without correspondences. Our method is based on a novel navigation interface that allows users to explore a collection of related shapes by deforming a base template shape through a set of intuitive deformation controls. We also help the user to select the most meaningful deformations using a novel technique for learning shape variability in terms of deformations of the template. Our technique assumes that the set of shapes lies near a low-dimensional manifold in a certain descriptor space, which allows us to avoid establishing correspondences between shapes, while being rotation and scaling invariant. We present results on several shape collections taken directly from public repositories. © 2011 ACM.

  6. Collective properties and shapes of nuclei at very high spins

    International Nuclear Information System (INIS)

    Johnson, N.R.

    1991-01-01

    A topic which has been of major interest to us for some years now involves the evolution of nuclear collectivity at high rotational frequencies and the accompanying changes in the shapes of nuclei in these extreme conditions. We carry out these studies by determining the dynamic electromagnetic multipole moments which are a reflection of the collective aspects of the nuclear wave functions. The most direct way to get these multipole moments is by measurements of excited-state lifetimes which provide the transition matrix elements in a fairly straightforward fashion. Although the primary emphasis of this paper is on the collectivity of the high-spin states in 160 Yb and 164 Yb, it is important to review briefly some work we began about ten years ago lifetime studies of moderately high spins in nuclei near N=90 using the recoil-distance (RD) method. These nuclei are just at the onset of permanent deformation and are known to be very soft with respect to deformation changes. This softness is clearly illustrated in contour diagrams of their potential-energy surfaces. For example, the potential energy surface of 160 Yb reveals that the minimum in the potential occurs around var-epsilon ∼ 0.2 and that it is very shallow in the γ degree of freedom. Because of their γ softness, we have studied several nuclei near N=90 to assess to what extent the polarization effects induced by rotation alignment of high-j quasiparticles affect their collectivity

  7. Reliability-Based Shape Optimization using Stochastic Finite Element Methods

    DEFF Research Database (Denmark)

    Enevoldsen, Ib; Sørensen, John Dalsgaard; Sigurdsson, G.

    1991-01-01

    stochastic fields (e.g. loads and material parameters such as Young's modulus and the Poisson ratio). In this case stochastic finite element techniques combined with FORM analysis can be used to obtain measures of the reliability of the structural systems, see Der Kiureghian & Ke (6) and Liu & Der Kiureghian...... (7). In this paper a reliability-based shape optimization problem is formulated with the total expected cost as objective function and some requirements for the reliability measures (element or systems reliability measures) as constraints, see section 2. As design variables sizing variables...

  8. An Optimization Approach to Improving Collections of Shape Maps

    DEFF Research Database (Denmark)

    Nguyen, Andy; Ben‐Chen, Mirela; Welnicka, Katarzyna

    2011-01-01

    us replace a “bad” pairwise map with the composition of a few “good” maps between shapes that in some sense interpolate the original ones. We show how, given a collection of pairwise shape maps, to define an optimization problem whose output is a set of alternative maps, compositions of those given...

  9. Shape Optimization of Unconstrained Viscoelastic Layers Using Continuum Finite Elements

    Science.gov (United States)

    Lumsdaine, A.; Scott, R. A.

    1998-09-01

    Of the many methods available for achieving effective vibration damping, adding viscoelastic lamina is a significant technique for vibration and reduction. Recently, the desire to apportion this material in a way that will take the greatest advantage of its dissipative characteristics has led to studies in optimization. Optimal design for viscoelastically damped laminated beams and plates undergoing harmonic excitation has been examined in the literature, both for constrained and unconstrained damping layers. However to the authors' knowledge, previous optimization studies have not used continuum based finite elements to model the structure, as is done here. The problem examined is the shape optimization of an unconstrained damping layer on an elastic structure, assuming a constant volume of damping material as a design constraint. The objective is to minimize the peak displacement. Several boundary conditions are examined for beam and plate type structures. The peak displacement and the loss factor of the optimized structure are compared with the uniform layer structure. Also, results obtained using realistic (frequency dependent) and constant viscoelastic material data are compared. The structures are modelled using continuum based elements in the ABAQUS Finite Element Code. The optimization code uses a Sequential Quadratic Programming algorithm. For most of the structures examined, order of magnitude improvement is seen as a result of optimizing the shape of the damping layer. Peak displacements are reduced by up to 98%. These results are quite robust, with the optimized damping layer achieving significantly better damping performance for a wide variety of cases examined.

  10. FINITE-ELEMENT MODELING OF WELDED X-SHAPED JOINT

    Directory of Open Access Journals (Sweden)

    V. V. Kyzniatsova

    2014-01-01

    Full Text Available The paper presents a modeling of non-stationary processes while making arc welding in the shielding gas medium of X-shaped joints which consist of re-bars having various diameters. Changes and specific features of stress-strain state in the X-shaped joint have been considered in the paper. Calculations are as much as possible approximated to a real situation: a 3D-geometrical and finite-element model is used, the problem is considered as elastic and contact one with due account of power loading. An analysis of the welded assembly consisting of re-bars with diameter of 4-10 mm has been performed using a finite element method. Computation of a welded connection with due consideration of geometrical nonlinearity has been done in the paper. It has been shown that tensile of re-bars under load causes uneven stress distribution in a welded joint and their significant concentration is observed at crossing points from the welded joint to a base metal. An analysis of the obtained equivalent stresses at nodes and details of the welded joint structure has shown that they did not exceed permissible values for all diameters in case of the considered loading conditions. A comparison of stress values calculated has been carried out in accordance with the proposed method and experimentally obtained data. It has been revealed that application of tensile load (determined experimentally to the connection stress values at the connection and welded joint boundary reach an yield strength and subsequently it causes destruction of the connection. It has been established that the margin of safety for such type of connections is averagely equal from 30 to 60 %. The submitted calculated data are in full agreement with experimental data that proves correctness in selection of calculation schemes and loads.

  11. Prolate non-collective shape- a rare shape phase around Z = 50

    International Nuclear Information System (INIS)

    Aggarwal, Mamta

    2009-01-01

    The search for rare shape-phase transition in hot and rotating nuclei is one of the very active field in nuclear physics research. According to universally known features of the evolution of equilibrium shapes with temperature and spin, heating a deformed nonrotating nucleus leads to a shape transition from deformed to spherical at a certain temperature. At high temperatures T≅ 2 MeV, the shell effects melt and the nucleus resembles a classical liquid drop. Rotation of the hot nucleus generates an oblate shape rotating noncollectively. But it has been shown by A. Goodman that nuclei with two critical temperatures can rotate with a rare non-collective prolate shape phase which has been caused directly by rotation at angular momentum values around (5-30h) which creates a residual quantum shell effect as shown by A. L. Goodman. Search for such exotic shape-phase around Z = 50 region is the aim of present work. We consider N = 60 isotones 108 Cd, 109 In, 110 Sn

  12. Impact of detector-element active-area shape and fill factor on super-resolution

    Directory of Open Access Journals (Sweden)

    Russell Craig Hardie

    2015-05-01

    Full Text Available In many undersampled imaging systems, spatial integration from the individual detector elements is the dominant component of the system point spread function (PSF. Conventional focal plane arrays (FPAs utilize square detector elements with a nearly 100% fill factor, where fill factor is defined as the fraction of the detector element area that is active in light detection. A large fill factor is generally considered to be desirable because more photons are collected for a given pitch, and this leads to a higher signal-to-noise-ratio (SNR. However, the large active area works against super-resolution (SR image restoration by acting as an additional low pass filter in the overall PSF when modeled on the SR sampling grid. A high fill factor also tends to increase blurring from pixel cross-talk. In this paper, we study the impact of FPA detector-element shape and fill factor on SR. A detailed modulation transfer function analysis is provided along with a number of experimental results with both simulated data and real data acquired with a midwave infrared (MWIR imaging system. We demonstrate the potential advantage of low fill factor detector elements when combined with SR image restoration. Our results suggest that low fill factor circular detector elements may be the best choice. New video results are presented using robust adaptive Wiener filter SR processing applied to data from a commercial MWIR imaging system with both high and low detector element fill factors.

  13. ShapePheno: unsupervised extraction of shape phenotypes from biological image collections.

    Science.gov (United States)

    Karaletsos, Theofanis; Stegle, Oliver; Dreyer, Christine; Winn, John; Borgwardt, Karsten M

    2012-04-01

    Accurate large-scale phenotyping has recently gained considerable importance in biology. For example, in genome-wide association studies technological advances have rendered genotyping cheap, leaving phenotype acquisition as the major bottleneck. Automatic image analysis is one major strategy to phenotype individuals in large numbers. Current approaches for visual phenotyping focus predominantly on summarizing statistics and geometric measures, such as height and width of an individual, or color histograms and patterns. However, more subtle, but biologically informative phenotypes, such as the local deformation of the shape of an individual with respect to the population mean cannot be automatically extracted and quantified by current techniques. We propose a probabilistic machine learning model that allows for the extraction of deformation phenotypes from biological images, making them available as quantitative traits for downstream analysis. Our approach jointly models a collection of images using a learned common template that is mapped onto each image through a deformable smooth transformation. In a case study, we analyze the shape deformations of 388 guppy fish (Poecilia reticulata). We find that the flexible shape phenotypes our model extracts are complementary to basic geometric measures. Moreover, these quantitative traits assort the observations into distinct groups and can be mapped to polymorphic genetic loci of the sample set. Code is available under: http://bioweb.me/GEBI CONTACT: theofanis.karaletsos@tuebingen.mpg.de; oliver.stegle@tuebingen.mpg.de Supplementary data are available at Bioinformatics online.

  14. Analysis of Essential and Toxic Elements in Jujube Fruits Collected ...

    African Journals Online (AJOL)

    Purpose: To develop a simple and precise method for the determination of the levels of both essential and toxic elements in jujube collected from different locations in China. Methods: Dried jujube fruits collected were digested by optimized microwave procedure. Inductively coupled plasma atomic emission spectrometry ...

  15. Reliability-Based Shape Optimization using Stochastic Finite Element Methods

    DEFF Research Database (Denmark)

    Enevoldsen, Ib; Sørensen, John Dalsgaard; Sigurdsson, G.

    1991-01-01

    stochastic fields (e.g. loads and material parameters such as Young's modulus and the Poisson ratio). In this case stochastic finite element techniques combined with FORM analysis can be used to obtain measures of the reliability of the structural systems, see Der Kiureghian & Ke (6) and Liu & Der Kiureghian...

  16. Finite Element Modeling and Optimization of Tube-Shaped Ultrasonic Motors

    National Research Council Canada - National Science Library

    Bouchilloux, P

    2003-01-01

    .... Then, we show how the finite element method (ATILA) can be used, in combination with genetic optimization procedures, to design tube-shaped motors in various dimensions and for different performance objectives. Several design examples are presented and discussed.

  17. Element shape design of 2-D CMUT arrays for reducing grating lobes.

    Science.gov (United States)

    Bavaro, Vito; Caliano, Giosuè; Pappalardo, Massimo

    2008-02-01

    Fully populated two-dimensional (2-D) arrays are needed to produce high quality ultrasonic volumetric images for real-time applications, but they present many challenges for their physical realization because of the large number of elements. In fact, lambda/2 and lambda minimum spacing between elements is required, respectively, for pyramidal and rectilinear scanning in order to avoid unwanted grating lobes (GLs). However, in past years, capacitive micromachined ultrasonic transducer (CMUT) technology has made possible the production of arrays with large flexibility in element shape and size. In this paper, this property is analyzed, and a new element shape, based on the concept of spatial interpenetration of adjacent elements, is proposed in order to design fully populated 2-D CMUT arrays with a low number of elements, whose beam characteristics are valid for volumetric imaging. Through the use of simulations, it is demonstrated that arrays with pitch larger than lambda (up to 3lambda) used for rectilinear scanning, have notably lower GLs than the equivalent standard arrays designed according to the classical squared element shape. As consequence, the proposed geometry has the advantage of reducing the number of elements (up to a factor of 9) and of enlarging the element size, implying an increase of the SNR relative to the single element. When beam steering is required, arrays can be designed with pitch equal to lambda, reducing the number of elements by a factor of 4 if the maximum steering angle is limited to +/-15 degrees .

  18. A Novel Shape-Free Plane Quadratic Polygonal Hybrid Stress-Function Element

    Directory of Open Access Journals (Sweden)

    Pei-Lei Zhou

    2015-01-01

    Full Text Available A novel plane quadratic shape-free hybrid stress-function (HS-F polygonal element is developed by employing the principle of minimum complementary energy and the fundamental analytical solutions of the Airy stress function. Without construction of displacement interpolation function, the formulations of the new model are much simpler than those of the displacement-based polygonal elements and can be degenerated into triangular or quadrilateral elements directly. In particular, it is quite insensitive to various mesh distortions and even can keep precision when element shape is concave. Furthermore, the element does not show any spurious zero energy modes. Numerical examples show the excellent performance of the new element, denoted by HSF-AP-19β, in both displacement and stress solutions.

  19. Two-dimensional finite element neutron diffusion analysis using hierarchic shape functions

    International Nuclear Information System (INIS)

    Carpenter, D.C.

    1997-01-01

    Recent advances have been made in the use of p-type finite element method (FEM) for structural and fluid dynamics problems that hold promise for reactor physics problems. These advances include using hierarchic shape functions, element-by-element iterative solvers and more powerful mapping techniques. Use of the hierarchic shape functions allows greater flexibility and efficiency in implementing energy-dependent flux expansions and incorporating localized refinement of the solution space. The irregular matrices generated by the p-type FEM can be solved efficiently using element-by-element conjugate gradient iterative solvers. These solvers do not require storage of either the global or local stiffness matrices and can be highly vectorized. Mapping techniques based on blending function interpolation allow exact representation of curved boundaries using coarse element grids. These features were implemented in a developmental two-dimensional neutron diffusion program based on the use of hierarchic shape functions (FEM2DH). Several aspects in the effective use of p-type analysis were explored. Two choices of elemental preconditioning were examined--the proper selection of the polynomial shape functions and the proper number of functions to use. Of the five shape function polynomials tested, the integral Legendre functions were the most effective. The serendipity set of functions is preferable over the full tensor product set. Two global preconditioners were also examined--simple diagonal and incomplete Cholesky. The full effectiveness of the finite element methodology was demonstrated on a two-region, two-group cylindrical problem but solved in the x-y coordinate space, using a non-structured element grid. The exact, analytic eigenvalue solution was achieved with FEM2DH using various combinations of element grids and flux expansions

  20. Flow shapes and higher harmonics in anisotropic transverse collective flow

    Energy Technology Data Exchange (ETDEWEB)

    Argintaru, Danut; Baban, Valerica [Constanta Maritime University, Faculty of Navigation and Naval Transport, Constanta (Romania); Besliu, Calin; Jipa, Alexandru; Grossu, Valeriu [University of Bucharest, Faculty of Physics, Bucharest (Romania); Esanu, Tiberiu; Cherciu, Madalin [Institute of Space Sciences Bucharest-Magurele, Bucharest (Romania)

    2017-01-15

    In this paper we show that by using a jet-finder algorithm (the Anti-k{sub T} one) on UrQMD/C simulated (Au+Au at 4, 10 and 15A GeV) collisions, we can identify different flow shape structures (single flow stream events, two flow streams events, three flow streams events, etc.) and order the bulk of events in equivalence flow shape classes. Considering these flow streams as the main directions of anisotropic transverse flow, we show that the Fourier coefficients v{sub n} of anisotropic flow are better emphasized when we analyze the different event flow shape classes than when the events are mixed. Also, if we do not know the real orientation of the reaction plane, we can use as reference the Flow stream 1 - the main particle flow stream - orientation (Ψ{sub Flowstream} {sub 1}) to highlight the initial shape of the participant nuclear matter in a central to peripheral collision, and the orientation of the participant plane of order n. (orig.)

  1. Analysis of Shape Nonconformity between Embroidered Element and Its Digital Image

    Directory of Open Access Journals (Sweden)

    Svetlana RADAVIČIENĖ

    2014-04-01

    Full Text Available Embroidery technologies are widely applied for developing decorative elements of original design in garments, for integrating threads intended for protection into garments and other articles. Nonconformity of the shape and dimensions of the embroidered element with the designed digital image is influenced by properties of embroidery threads and fibres, by the filling type, density of stitches and other technological parameters. The objective of the paper is to explore the influence made by properties of fabrics and by the direction of stitches of the actual embroidered element on conformity of the shape with one of the designed digital image. For the research, embroidery threads of different purpose as well as three woven fabrics have been selected. For preparation of test samples, round digital images have been designed filling the embroidery area in different stitch directions. Analysis of the results of the investigations has demonstrated that the shape and dimensions of the embroidered element failed to conform to the shape and dimensions of the designed digital image in most cases. In certain cases, e.g. when the stitch direction goes towards the middle of the embroidered element, a defect, i. e. hole, is observed due to considerable concentration of stitches in the centre of the element.DOI: http://dx.doi.org/10.5755/j01.ms.20.1.2911

  2. Simultaneous Topology, Shape, and Sizing Optimisation of Plane Trusses with Adaptive Ground Finite Elements Using MOEAs

    Directory of Open Access Journals (Sweden)

    Norapat Noilublao

    2013-01-01

    Full Text Available This paper proposes a novel integrated design strategy to accomplish simultaneous topology shape and sizing optimisation of a two-dimensional (2D truss. An optimisation problem is posed to find a structural topology, shape, and element sizes of the truss such that two objective functions, mass and compliance, are minimised. Design constraints include stress, buckling, and compliance. The procedure for an adaptive ground elements approach is proposed and its encoding/decoding process is detailed. Two sets of design variables defining truss layout, shape, and element sizes at the same time are applied. A number of multiobjective evolutionary algorithms (MOEAs are implemented to solve the design problem. Comparative performance based on a hypervolume indicator shows that multiobjective population-based incremental learning (PBIL is the best performer. Optimising three design variable types simultaneously is more efficient and effective.

  3. Non-linear shape functions over time in the space-time finite element method

    Directory of Open Access Journals (Sweden)

    Kacprzyk Zbigniew

    2017-01-01

    Full Text Available This work presents a generalisation of the space-time finite element method proposed by Kączkowski in his seminal of 1970’s and early 1980’s works. Kączkowski used linear shape functions in time. The recurrence formula obtained by Kączkowski was conditionally stable. In this paper, non-linear shape functions in time are proposed.

  4. Crystal plasticity finite element simulation of NiTi shape memory alloy based on representative volume element

    Science.gov (United States)

    Hu, Li; Jiang, Shuyong; Zhang, Yanqiu; Sun, Dong

    2017-11-01

    Crystal plasticity finite element method based on a representative volume element model, which includes the effect of grain shape and size, is combined with electron backscattered diffraction experiment in order to investigate plastic deformation of NiTi shape memory alloy during uniaxial compression at 400 °C. Simulation results indicate that the constructed representation of the polycrystal microstructure is able to effectively simulate macroscopically global stress-strain response and microscopically inhomogeneous microstructure evolution in the case of various loading directions. According to slip activity and Schmid factor in {110}, {010} and {110} slip modes, slip modes are found to play a dominant role in plastic deformation, while slip mode is found to be a secondary slip mode. In addition, the simulation results are supported well by the experimental ones. With the progression of plastic deformation, the (001) [0\\bar 10] texture component gradually disappears, while the γ-fiber () texture is increasingly enhanced.

  5. A Review of Discrete Element Method (DEM) Particle Shapes and Size Distributions for Lunar Soil

    Science.gov (United States)

    Lane, John E.; Metzger, Philip T.; Wilkinson, R. Allen

    2010-01-01

    As part of ongoing efforts to develop models of lunar soil mechanics, this report reviews two topics that are important to discrete element method (DEM) modeling the behavior of soils (such as lunar soils): (1) methods of modeling particle shapes and (2) analytical representations of particle size distribution. The choice of particle shape complexity is driven primarily by opposing tradeoffs with total number of particles, computer memory, and total simulation computer processing time. The choice is also dependent on available DEM software capabilities. For example, PFC2D/PFC3D and EDEM support clustering of spheres; MIMES incorporates superquadric particle shapes; and BLOKS3D provides polyhedra shapes. Most commercial and custom DEM software supports some type of complex particle shape beyond the standard sphere. Convex polyhedra, clusters of spheres and single parametric particle shapes such as the ellipsoid, polyellipsoid, and superquadric, are all motivated by the desire to introduce asymmetry into the particle shape, as well as edges and corners, in order to better simulate actual granular particle shapes and behavior. An empirical particle size distribution (PSD) formula is shown to fit desert sand data from Bagnold. Particle size data of JSC-1a obtained from a fine particle analyzer at the NASA Kennedy Space Center is also fitted to a similar empirical PSD function.

  6. Characterization of NiTi Shape Memory Damping Elements designed for Automotive Safety Systems

    Science.gov (United States)

    Strittmatter, Joachim; Clipa, Victor; Gheorghita, Viorel; Gümpel, Paul

    2014-07-01

    Actuator elements made of NiTi shape memory material are more and more known in industry because of their unique properties. Due to the martensitic phase change, they can revert to their original shape by heating when subjected to an appropriate treatment. This thermal shape memory effect (SME) can show a significant shape change combined with a considerable force. Therefore such elements can be used to solve many technical tasks in the field of actuating elements and mechatronics and will play an increasing role in the next years, especially within the automotive technology, energy management, power, and mechanical engineering as well as medical technology. Beside this thermal SME, these materials also show a mechanical SME, characterized by a superelastic plateau with reversible elongations in the range of 8%. This behavior is based on the building of stress-induced martensite of loaded austenite material at constant temperature and facilitates a lot of applications especially in the medical field. Both SMEs are attended by energy dissipation during the martensitic phase change. This paper describes the first results obtained on different actuator and superelastic NiTi wires concerning their use as damping elements in automotive safety systems. In a first step, the damping behavior of small NiTi wires up to 0.5 mm diameter was examined at testing speeds varying between 0.1 and 50 mm/s upon an adapted tensile testing machine. In order to realize higher testing speeds, a drop impact testing machine was designed, which allows testing speeds up to 4000 mm/s. After introducing this new type of testing machine, the first results of vertical-shock tests of superelastic and electrically activated actuator wires are presented. The characterization of these high dynamic phase change parameters represents the basis for new applications for shape memory damping elements, especially in automotive safety systems.

  7. Simple Methods to Approximate CPC Shape to Preserve Collection Efficiency

    Directory of Open Access Journals (Sweden)

    David Jafrancesco

    2012-01-01

    Full Text Available The compound parabolic concentrator (CPC is the most efficient reflective geometry to collect light to an exit port. Anyway, to allow its actual use in solar plants or photovoltaic concentration systems, a tradeoff between system efficiency and cost reduction, the two key issues for sunlight exploitation, must be found. In this work, we analyze various methods to model an approximated CPC aimed to be simpler and more cost-effective than the ideal one, as well as to preserve the system efficiency. The manufacturing easiness arises from the use of truncated conic surfaces only, which can be realized by cheap machining techniques. We compare different configurations on the basis of their collection efficiency, evaluated by means of nonsequential ray-tracing software. Moreover, due to the fact that some configurations are beam dependent and for a closer approximation of a real case, the input beam is simulated as nonsymmetric, with a nonconstant irradiance on the CPC internal surface.

  8. An optimization approach for extracting and encoding consistent maps in a shape collection

    KAUST Repository

    Huang, Qi-Xing

    2012-11-01

    We introduce a novel approach for computing high quality point-topoint maps among a collection of related shapes. The proposed approach takes as input a sparse set of imperfect initial maps between pairs of shapes and builds a compact data structure which implicitly encodes an improved set of maps between all pairs of shapes. These maps align well with point correspondences selected from initial maps; they map neighboring points to neighboring points; and they provide cycle-consistency, so that map compositions along cycles approximate the identity map. The proposed approach is motivated by the fact that a complete set of maps between all pairs of shapes that admits nearly perfect cycleconsistency are highly redundant and can be represented by compositions of maps through a single base shape. In general, multiple base shapes are needed to adequately cover a diverse collection. Our algorithm sequentially extracts such a small collection of base shapes and creates correspondences from each of these base shapes to all other shapes. These correspondences are found by global optimization on candidate correspondences obtained by diffusing initial maps. These are then used to create a compact graphical data structure from which globally optimal cycle-consistent maps can be extracted using simple graph algorithms. Experimental results on benchmark datasets show that the proposed approach yields significantly better results than state-of-theart data-driven shape matching methods. © 2012 ACM.

  9. The Research on the Width of the Closed-Circuit Square-shaped Embroidery Element

    Directory of Open Access Journals (Sweden)

    Žaneta JUCHNEVIČIENĖ

    2017-08-01

    Full Text Available In modern manufacturing embroidered elements are used in such areas as implant production, rehabilitation (e.g., embroidered sensors, medical diagnostics, production of smart garments etc., where high accuracy is required to maintain the functionality of the product. Due to the influence of mechanical forces taking part in the embroidery process, the embroidery system is deformed, resulting in noncompliance of the embroidery element with the digitally designed one. Three fabrics have been selected as the objects of the research with the fiber composition of 65 % polyester and 35 % cotton, differing by weave and density. 60 × 60 mm and 6 mm wide closed circuit square-shaped embroidery elements have been used for the research. According to the performed analysis of the results, the dimensions of the closed-circuit square-shaped embroidery element have changed in comparison to that of the digitally designed one. The width of the embroidery element, which was the most adequate to the digitally designed one, was achieved in the direction of warp. The obtained results have shown that in the corners the width of the embroidery element in the directions of warp and weft is bigger than the one in the centers of the segments.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.16095

  10. Shape and Stress Sensing of Multilayered Composite and Sandwich Structures Using an Inverse Finite Element Method

    Science.gov (United States)

    Cerracchio, Priscilla; Gherlone, Marco; Di Sciuva, Marco; Tessler, Alexander

    2013-01-01

    The marked increase in the use of composite and sandwich material systems in aerospace, civil, and marine structures leads to the need for integrated Structural Health Management systems. A key capability to enable such systems is the real-time reconstruction of structural deformations, stresses, and failure criteria that are inferred from in-situ, discrete-location strain measurements. This technology is commonly referred to as shape- and stress-sensing. Presented herein is a computationally efficient shape- and stress-sensing methodology that is ideally suited for applications to laminated composite and sandwich structures. The new approach employs the inverse Finite Element Method (iFEM) as a general framework and the Refined Zigzag Theory (RZT) as the underlying plate theory. A three-node inverse plate finite element is formulated. The element formulation enables robust and efficient modeling of plate structures instrumented with strain sensors that have arbitrary positions. The methodology leads to a set of linear algebraic equations that are solved efficiently for the unknown nodal displacements. These displacements are then used at the finite element level to compute full-field strains, stresses, and failure criteria that are in turn used to assess structural integrity. Numerical results for multilayered, highly heterogeneous laminates demonstrate the unique capability of this new formulation for shape- and stress-sensing.

  11. Optically Controlled Reconfigurable Antenna Array Based on E-Shaped Elements

    Directory of Open Access Journals (Sweden)

    Arismar Cerqueira Sodré Junior

    2014-01-01

    Full Text Available This work presents the development of optically controlled reconfigurable antenna arrays. They are based on two patch elements with E-shaped slots, a printed probe, and a photoconductive switch made from an intrinsic silicon die. Numerical simulations and experiments have been shown to be in agreement, and both demonstrate that the frequency response of the antenna arrays can be efficiently reconfigured over two different frequency ISM bands, namely, 2.4 and 5 GHz. A measured gain of 12.5 dBi has been obtained through the use of two radiating elements printed in a low-cost substrate and a dihedral corner reflector.

  12. Nonlinear finite element formulation for analyzing shape memory alloy cylindrical panels

    International Nuclear Information System (INIS)

    Mirzaeifar, R; Shakeri, M; Sadighi, M

    2009-01-01

    In this paper, a general incremental displacement based finite element formulation capable of modeling material nonlinearities based on first-order shear deformation theory (FSDT) is developed for cylindrical shape memory alloy (SMA) shells. The Boyd–Lagoudas phenomenological model with polynomial hardening in conjunction with 3D incremental convex cutting plane explicit algorithm is implemented for preparing the SMA constitutive model in the finite element formulation. Several numerical examples are presented for demonstrating the performance of the proposed formulation in stress, deflection and phase transformation analysis of pseudoelastic behavior of shape memory cylindrical panels with various boundary conditions. Also, it is shown that the presented formulation can be implemented for studying plates and beams with rectangular cross section

  13. Optimal Shape for Forces and Moments on a Multi-Element Hydrofoil

    Science.gov (United States)

    2007-10-01

    Hydrofoil DISTRIBUTION: Approved for public release; distribution is unlimited. This paper is part of the following report: TITLE: International...Michigan, 5-8 August 2007 Optimal Shape for Forces and Moments on a Multi-Element Hydrofoil Yu-Tai Lee1, Vineet Ahuja 2, Ashvin Hosangadi 2 and Michael...forces and The Tab Assisted Control (TAC) foil used for moments acting on the hydrofoil with adequate underwater control surfaces, shown in Fig. la, was

  14. Simulation of crack propagation in anisotropic structures using the boundary element shape sensitivities and optimisation techniques

    OpenAIRE

    Tafreshi, Azam

    2011-01-01

    Using the boundary element shape sensitivities of multi-region domains coupled with an optimisation algorithm and an automatic mesh generator, the crack kink angle and propagation path in anisotropic elastic solids are predicted. The maximum strain energy release rate criterion, best suited for the composite structures, has been employed. In contrast to the J-integral method, which would require the computation of stresses and strains at a series of internal points, here by direct differentia...

  15. Control of Gas Tungsten Arc welding pool shape by trace element addition to the weld pool

    Science.gov (United States)

    Heiple, C.R.; Burgardt, P.

    1984-03-13

    An improved process for Gas Tungsten Arc welding maximizes the depth/width ratio of the weld pool by adding a sufficient amount of a surface active element to insure inward fluid flow, resulting in deep, narrow welds. The process is especially useful to eliminate variable weld penetration and shape in GTA welding of steels and stainless steels, particularly by using a sulfur-doped weld wire in a cold wire feed technique.

  16. An explanation for the shape of nanoindentation unloading curves based on finite element simulation

    International Nuclear Information System (INIS)

    Bolshakov, A.; Pharr, G.M.

    1995-01-01

    Current methods for measuring hardness and modulus from nanoindentation load-displacement data are based on Sneddon's equations for the indentation of an elastic half-space by an axially symmetric rigid punch. Recent experiments have shown that nanoindentation unloading data are distinctly curved in a manner which is not consistent with either the flat punch or the conical indenter geometries frequently used in modeling, but are more closely approximated by a parabola of revolution. Finite element simulations for conical indentation of an elastic-plastic material are presented which corroborate the experimental observations, and from which a simple explanation for the shape of the unloading curve is derived. The explanation is based on the concept of an effective indenter shape whose geometry is determined by the shape of the plastic hardness impression formed during indentation

  17. Beam shaping for multicolour light-emitting diodes with diffractive optical elements

    KAUST Repository

    Yu, Chao

    2016-10-06

    An improved particle swarm optimization method is proposed for the design of ultra-thin diffractive optical elements (DOEs) enabling multicolour beam shaping functionality. We employ pre-optimized initial structures and adaptive weight strategy in the algorithm to achieve better and identical shaping performance for multiple colours. Accordingly, a DOE for shaping light from green and blue LEDs has been designed and fabricated. Both experiment and numerical simulations have been conducted and the results agree well with each other. 15.66% average root mean square error (RMSE) and 0.22% RMSE difference are achieved. In addition, the parameters closely related to the performance of the optimization are analysed, which can provide insights for future application designs.

  18. Analysis on the geometrical shape of T-honeycomb structure by finite element method (FEM)

    Science.gov (United States)

    Zain, Fitri; Rosli, Muhamad Farizuan; Effendi, M. S. M.; Abdullah, Mohamad Hariri

    2017-09-01

    Geometric in design is much related with our life. Each of the geometrical structure interacts with each other. The overall shape of an object contains other shape inside, and there shapes create a relationship between each other in space. Besides that, how geometry relates to the function of the object have to be considerate. In this project, the main purpose was to design the geometrical shape of modular furniture with the shrinking of Polyethylene Terephthalate (PET) jointing system that has good strength when applied load on it. But, the goal of this paper is focusing on the analysis of Static Cases by FEM of the hexagonal structure to obtain the strength when load apply on it. The review from the existing product has many information and very helpful to finish this paper. This project focuses on hexagonal shape that distributed to become a shelf inspired by honeycomb structure. It is very natural look and simple in shape and its modular structure more easily to separate and combine. The method discusses on chapter methodology are the method used to analysis the strength when the load applied to the structure. The software used to analysis the structure is Finite Element Method from CATIA V5R21 software. Bending test is done on the jointing part between the edges of the hexagonal shape by using Universal Tensile Machine (UTM). The data obtained have been calculate by bending test formulae and sketch the graph between flexural strains versus flexural stress. The material selection of the furniture is focused on wood. There are three different types of wood such as balsa, pine and oak, while the properties of jointing also be mentioned in this thesis. Hence, the design structural for honeycomb shape already have in the market but this design has main objective which has a good strength that can withstand maximum load and offers more potentials in the form of furniture.

  19. Shape matters: Near-field fluid mechanics dominate the collective motions of ellipsoidal squirmers.

    Science.gov (United States)

    Kyoya, K; Matsunaga, D; Imai, Y; Omori, T; Ishikawa, T

    2015-12-01

    Microswimmers show a variety of collective motions. Despite extensive study, questions remain regarding the role of near-field fluid mechanics in collective motion. In this paper, we describe precisely the Stokes flow around hydrodynamically interacting ellipsoidal squirmers in a monolayer suspension. The results showed that various collective motions, such as ordering, aggregation, and whirls, are dominated by the swimming mode and the aspect ratio. The collective motions are mainly induced by near-field fluid mechanics, despite Stokes flow propagation over a long range. These results emphasize the importance of particle shape in collective motion.

  20. [Three-dimensional Finite Element Analysis to T-shaped Fracture of Pelvis in Sitting Position].

    Science.gov (United States)

    Fan, Yanping; Lei, Jianyin; Liu, Haibo; Li, Zhiqiang; Cai, Xianhua; Chen, Weiyi

    2015-10-01

    We developed a three-dimensional finite element model of the pelvis. According to Letournel methods, we established a pelvis model of T-shaped fracture with its three different fixation systems, i. e. double column reconstruction plates, anterior column plate combined with posterior column screws and anterior column plate combined with quadrilateral area screws. It was found that the pelvic model was effective and could be used to simulate the mechanical behavior of the pelvis. Three fixation systems had great therapeutic effect on the T-shaped fracture. All fixation systems could increase the stiffness of the model, decrease the stress concentration level and decrease the displacement difference along the fracture line. The quadrilateral area screws, which were drilled into cortical bone, could generate beneficial effect on the T-type fracture. Therefore, the third fixation system mentioned above (i. e. the anterior column plate combined with quadrilateral area screws) has the best biomechanical stability to the T-type fracture.

  1. Modification of Ni-Mn-Ga ferromagnetic shape memory alloy by addition of rare earth elements

    International Nuclear Information System (INIS)

    Tsuchiya, Koichi; Tsutsumi, Akinori; Ohtsuka, Hideyuki; Umemoto, Minoru

    2003-01-01

    Effect of addition of rare earth elements, such as, Nd, Sm and Tb, was investigated on various properties of Ni-Mn-Ga ferromagnetic shape memory alloys (SMAs). The solubility of the rare earth in the L2 1 phase was found to be very low, most likely less than 0.1 mol%. Insolvable rare earth segregated into subgrain boundaries or grain boundaries to form precipitates. Phase transformation behavior and the structure of martensite phase exhibit a similar dependence on valence electron concentration to those in ternary Ni-Mn-Ga alloys. It was revealed that the addition of rare earth significantly improves the compressive ductility of the alloy

  2. Roughness’s shapes comparative analysis of some reinforced earth elements under monotonous loading

    Directory of Open Access Journals (Sweden)

    Mohamed Khemissa

    2015-09-01

    Full Text Available This paper presents and analyzes the experimental and numerical results of a series of pullout tests under monotonous loading performed on five steel strips presenting various forms of roughness (smooth, ribbed, punched, W-shaped, chain and embedded in the same dry sand massif constituting the backfill. The pullout tests were conducted by means of a small-scale model and the calculations carried out by using a finite elements computer program. Obtained results show a good agreement between the experimental and numerical data. They show in addition that the rough strips are more advantageous than the smooth strip. Among the rough strips considered, chain is most relevant.

  3. Finite Element Analysis of a Copper Single Crystal Shape Memory Alloy-Based Endodontic Instruments

    Science.gov (United States)

    Vincent, Marin; Thiebaud, Frédéric; Bel Haj Khalifa, Saifeddine; Engels-Deutsch, Marc; Ben Zineb, Tarak

    2015-10-01

    The aim of the present paper is the development of endodontic Cu-based single crystal Shape Memory Alloy (SMA) instruments in order to eliminate the antimicrobial and mechanical deficiencies observed with the conventional Nickel-Titane (NiTi) SMA files. A thermomechanical constitutive law, already developed and implemented in a finite element code by our research group, is adopted for the simulation of the single crystal SMA behavior. The corresponding material parameters were identified starting from experimental results for a tensile test at room temperature. A computer-aided design geometry has been achieved and considered for a finite element structural analysis of the endodontic Cu-based single crystal SMA files. They are meshed with tetrahedral continuum elements to improve the computation time and the accuracy of results. The geometric parameters tested in this study are the length of the active blade, the rod length, the pitch, the taper, the tip diameter, and the rod diameter. For each set of adopted parameters, a finite element model is built and tested in a combined bending-torsion loading in accordance with ISO 3630-1 norm. The numerical analysis based on finite element procedure allowed purposing an optimal geometry suitable for Cu-based single crystal SMA endodontic files. The same analysis was carried out for the classical NiTi SMA files and a comparison was made between the two kinds of files. It showed that Cu-based single crystal SMA files are less stiff than the NiTi files. The Cu-based endodontic files could be used to improve the root canal treatments. However, the finite element analysis brought out the need for further investigation based on experiments.

  4. Automated Identification and Shape Analysis of Chorus Elements in the Van Allen Radiation Belts

    Science.gov (United States)

    Sen Gupta, Ananya; Kletzing, Craig; Howk, Robin; Kurth, William; Matheny, Morgan

    2017-12-01

    An important goal of the Van Allen Probes mission is to understand wave-particle interaction by chorus emissions in terrestrial Van Allen radiation belts. To test models, statistical characterization of chorus properties, such as amplitude variation and sweep rates, is an important scientific goal. The Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instrumentation suite provides measurements of wave electric and magnetic fields as well as DC magnetic fields for the Van Allen Probes mission. However, manual inspection across terabytes of EMFISIS data is not feasible and as such introduces human confirmation bias. We present signal processing techniques for automated identification, shape analysis, and sweep rate characterization of high-amplitude whistler-mode chorus elements in the Van Allen radiation belts. Specifically, we develop signal processing techniques based on the radon transform that disambiguate chorus elements with a dominant sweep rate against hiss-like chorus. We present representative results validating our techniques and also provide statistical characterization of detected chorus elements across a case study of a 6 s epoch.

  5. Effects of shape distortions and imperfections on mode frequencies and collective linewidths in nanomagnets

    Science.gov (United States)

    Nembach, H. T.; Shaw, Justin M.; Silva, T. J.; Johnson, W. L.; Kim, S. A.; McMichael, R. D.; Kabos, P.

    2011-03-01

    Brillouin light scattering shows that shape distortions in Ni80Fe20 nanomagnets can have a dramatic effect on the measured collective linewidth of certain spin-wave modes. The intentional introduction of quantifiable asymmetric egglike shape distortion to an ideal elliptical structure lifts the degeneracy of end modes with concentrated amplitude at the nanomagnet edges. In contrast, modes with concentrated amplitude at the interior are significantly less affected by the distortion. The splitting of end modes by asymmetric distortions explains the large inhomogeneous linewidth broadening in end modes found in large ensembles of nanomagnets that contain a relatively small statistical variation in the degree of distortion.

  6. Finite element analysis of Al 2024/Cu-Al-Ni shape memory alloy composites with defects/cracks

    Science.gov (United States)

    Kotresh, M.; Benal, M. M., Dr; Siddalinga Swamy, N. H., Dr

    2018-02-01

    In this work, a numerical approach to predict the stress field behaviour of defect/crack in shape memory alloy (SMA) particles reinforced composite known as the adaptive composite is presented. Simulation is based on the finite element method. The critical stress field approach was used to determine the stresses around defect/crack. Thereby stress amplification issue is being resolved. In this paper, the effect volume % of shape memory alloy and shape memory effect of reinforcement for as-cast and SME trained composites are examined and discussed. Shape memory effect known as training is achieved by pre-straining of reinforcement particles by equivalent changes in their expansion coefficients.

  7. Finite element model of size, shape and blood pressure on rupture of intracranial saccular aneurysms

    Science.gov (United States)

    Rica Nabong, Jennica; David, Guido

    2017-10-01

    Rupture of intracranial saccular aneurysms is a primary concern for neurologists and patients because it leads to stroke and permanent disability. This paper examines the role of blood pressure, in connection with size of and wall thickness, in the rupture of saccular aneurysms. A bulb-shaped geometry of a saccular aneurysm is obtained from angiographic images of a patient and modeled using Finite Elements based on the principle of virtual work under the Fung stress-strain relationship. The numerical model is subjected to varying levels of systolic blood pressure. Rupture is assumed to occur when the wall stress exceeded its mechanical strength. The results show which sizes of this class of aneurysms are at high risk of rupture for varying levels of blood pressure.

  8. Modeling of Sensor Placement Strategy for Shape Sensing and Structural Health Monitoring of a Wing-Shaped Sandwich Panel Using Inverse Finite Element Method

    Directory of Open Access Journals (Sweden)

    Adnan Kefal

    2017-11-01

    Full Text Available This paper investigated the effect of sensor density and alignment for three-dimensional shape sensing of an airplane-wing-shaped thick panel subjected to three different loading conditions, i.e., bending, torsion, and membrane loads. For shape sensing analysis of the panel, the Inverse Finite Element Method (iFEM was used together with the Refined Zigzag Theory (RZT, in order to enable accurate predictions for transverse deflection and through-the-thickness variation of interfacial displacements. In this study, the iFEM-RZT algorithm is implemented by utilizing a novel three-node C°-continuous inverse-shell element, known as i3-RZT. The discrete strain data is generated numerically through performing a high-fidelity finite element analysis on the wing-shaped panel. This numerical strain data represents experimental strain readings obtained from surface patched strain gauges or embedded fiber Bragg grating (FBG sensors. Three different sensor placement configurations with varying density and alignment of strain data were examined and their corresponding displacement contours were compared with those of reference solutions. The results indicate that a sparse distribution of FBG sensors (uniaxial strain measurements, aligned in only the longitudinal direction, is sufficient for predicting accurate full-field membrane and bending responses (deformed shapes of the panel, including a true zigzag representation of interfacial displacements. On the other hand, a sparse deployment of strain rosettes (triaxial strain measurements is essentially enough to produce torsion shapes that are as accurate as those of predicted by a dense sensor placement configuration. Hence, the potential applicability and practical aspects of i3-RZT/iFEM methodology is proven for three-dimensional shape-sensing of future aerospace structures.

  9. Modeling of Sensor Placement Strategy for Shape Sensing and Structural Health Monitoring of a Wing-Shaped Sandwich Panel Using Inverse Finite Element Method.

    Science.gov (United States)

    Kefal, Adnan; Yildiz, Mehmet

    2017-11-30

    This paper investigated the effect of sensor density and alignment for three-dimensional shape sensing of an airplane-wing-shaped thick panel subjected to three different loading conditions, i.e., bending, torsion, and membrane loads. For shape sensing analysis of the panel, the Inverse Finite Element Method (iFEM) was used together with the Refined Zigzag Theory (RZT), in order to enable accurate predictions for transverse deflection and through-the-thickness variation of interfacial displacements. In this study, the iFEM-RZT algorithm is implemented by utilizing a novel three-node C°-continuous inverse-shell element, known as i3-RZT. The discrete strain data is generated numerically through performing a high-fidelity finite element analysis on the wing-shaped panel. This numerical strain data represents experimental strain readings obtained from surface patched strain gauges or embedded fiber Bragg grating (FBG) sensors. Three different sensor placement configurations with varying density and alignment of strain data were examined and their corresponding displacement contours were compared with those of reference solutions. The results indicate that a sparse distribution of FBG sensors (uniaxial strain measurements), aligned in only the longitudinal direction, is sufficient for predicting accurate full-field membrane and bending responses (deformed shapes) of the panel, including a true zigzag representation of interfacial displacements. On the other hand, a sparse deployment of strain rosettes (triaxial strain measurements) is essentially enough to produce torsion shapes that are as accurate as those of predicted by a dense sensor placement configuration. Hence, the potential applicability and practical aspects of i3-RZT/iFEM methodology is proven for three-dimensional shape-sensing of future aerospace structures.

  10. Fast ion collective Thomson scattering diagnostic for ITER: Design elements

    DEFF Research Database (Denmark)

    Tsakadze, Erekle; Bindslev, Henrik; Korsholm, Søren Bang

    2008-01-01

    The proposed fast ion collective Thomson scattering (CTS) diagnostic system for ITER provides the unique capability of measuring the temporally and spatially resolved velocity distribution of the confined fast ions and fusion alpha particles in a burning ITER plasma. The present paper describes t...... in the studies, and new HFS receiver mock-up measurements are presented as well as neutron flux calculations of the influence of the increased slot height....

  11. Implementation of a finite element analysis procedure for structural analysis of shape memory behaviour of fibre reinforced shape memory polymer composites

    Science.gov (United States)

    Azzawi, Wessam Al; Epaarachchi, J. A.; Islam, Mainul; Leng, Jinsong

    2017-12-01

    Shape memory polymers (SMPs) offer a unique ability to undergo a substantial shape deformation and subsequently recover the original shape when exposed to a particular external stimulus. Comparatively low mechanical properties being the major drawback for extended use of SMPs in engineering applications. However the inclusion of reinforcing fibres in to SMPs improves mechanical properties significantly while retaining intrinsic shape memory effects. The implementation of shape memory polymer composites (SMPCs) in any engineering application is a unique task which requires profound materials and design optimization. However currently available analytical tools have critical limitations to undertake accurate analysis/simulations of SMPC structures and slower derestrict transformation of breakthrough research outcomes to real-life applications. Many finite element (FE) models have been presented. But majority of them require a complicated user-subroutines to integrate with standard FE software packages. Furthermore, those subroutines are problem specific and difficult to use for a wider range of SMPC materials and related structures. This paper presents a FE simulation technique to model the thermomechanical behaviour of the SMPCs using commercial FE software ABAQUS. Proposed technique incorporates material time-dependent viscoelastic behaviour. The ability of the proposed technique to predict the shape fixity and shape recovery was evaluated by experimental data acquired by a bending of a SMPC cantilever beam. The excellent correlation between the experimental and FE simulation results has confirmed the robustness of the proposed technique.

  12. Constitutive model for shape memory alloys and its use in design and finite element analysis

    Science.gov (United States)

    Bose, Sudip; Santhanam, Sridhar

    2002-07-01

    A constitutive model for predicting the thermomechanical behavior of Shape Memory Alloys (SMAs) has been developed and validated. The model uses an approach similar to Brinson, Liang and Rogers, and Tanaka. It links key thermomechanical variables: stress, strain, temperature, and martensite fraction. A basic differential form for the SMA constitutive behavior, developed by Tanaka, forms the foundation of the model. The model is completed with a definition of the rules governing the behavior of martensite fraction. Like Brinson, the model distinguishes between de-twinned and twinned martensite. The phase transition temperatures are assumed to be a linear function of applied stress. The forward and reverse phase transformations are described by piecewise exponential functions. There are a number of parameters in the model that need to be determined using experimental data. The critical transformation temperatures are determined by resistivity measurements. All other parameters are determined by mechanical tension testing followed by nonlinear least-squares estimations. Mechanical testing consisted of displacement controlled, tension tests on Nitinol wires at several temperatures. The effectiveness of this model is demonstrated by its use in the design of an SMA actuated robotic arm. The constitutive model is used in conjunction with a lumped heat transfer model, a kinematic model, and a dynamic model to predict the behavior of the arm. Comparison between predictions and experimentally observed behavior is very good indicating a sound constitutive model. The model is also built into a finite element code that simulates pseudoelastic SMA behavior. The code considers geometric and material nonlinearities. The behavior of a simple pseudoelastic device is shown to be well predicted by the finite element code.

  13. Tetrathionate and Elemental Sulfur Shape the Isotope Composition of Sulfate in Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Nurgul Balci

    2017-08-01

    , acid production, and mixed valence state sulfur species generated by the oxidation of the two different substrates suggests a metabolic flexibility in response to sulfur substrate availability. Our results demonstrate that microbial processing of mixed-valence-state sulfur species generates a significant sulfur isotope fractionation in acidic environments and oxidation of mixed-valence state sulfur species may produce sulfate with characteristic sulfur and oxygen isotope signatures. Elemental sulfur and tetrathionate are not only intermediate-valence state sulfur compounds that play a central role in sulfur oxidation pathways, but also key factors in shaping these isotope patterns.

  14. Proton radioactivity at non-collective prolate shape in high spin state of 94Ag

    International Nuclear Information System (INIS)

    Aggarwal, Mamta

    2010-01-01

    We predict proton radioactivity and structural transitions in high spin state of an excited exotic nucleus near proton drip line in a theoretical framework and investigate the nature and the consequences of the structural transitions on separation energy as a function of temperature and spin. It reveals that the rotation of the excited exotic nucleus 94 Ag at excitation energies around 6.7 MeV and angular momentum near 21h generates a rarely seen prolate non-collective shape and proton separation energy becomes negative which indicates proton radioactivity in agreement with the experimental results of Mukha et al. for 94 Ag.

  15. Proton radioactivity at non-collective prolate shape in high spin state of {sup 94}Ag

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Mamta, E-mail: mamta.a4@gmail.co [UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Kalina Campus, Mumbai 400 098 (India)

    2010-10-11

    We predict proton radioactivity and structural transitions in high spin state of an excited exotic nucleus near proton drip line in a theoretical framework and investigate the nature and the consequences of the structural transitions on separation energy as a function of temperature and spin. It reveals that the rotation of the excited exotic nucleus {sup 94}Ag at excitation energies around 6.7 MeV and angular momentum near 21h generates a rarely seen prolate non-collective shape and proton separation energy becomes negative which indicates proton radioactivity in agreement with the experimental results of Mukha et al. for {sup 94}Ag.

  16. Determination of trace elements concentrations in Grewia tenax plants collected from Darfur Region-Sudan

    International Nuclear Information System (INIS)

    Alzain, H. A; Ebrahim, A. M; Salih, A. M; Ali Altom, M. S.

    2016-01-01

    This study is aimed to determine trace elements concentrations (Ca, Cu, Cr, K,Fe, Mn, Ni, Sr and Zn) in Grewia tenax collected from Darfur state western of Sudan. X- ray fluorescence (X RF) technique was used to determine elements concentration. A series of plant standard reference materials(ISE 2012-1) were used to check the reliability of employed technique by comparing the obtained results with the certified values, to estimate possible factors for correcting the concentration of some elements. The results showed that, X RF is a suitable method for measuring Ca, Cu, K, Fe, Mn, Sr and Zn elements. On the other hand, X RF for Cr and Ni determination in plant samples, these elements have showed a deviation from their certified values. Concentration of Fe was about 35 mg/kg in Grewia tenax samples where as K and Ca showed maximum levels about 16000 and 8500 mg/kg respectively, Cu showed minimum concentration about 10 mg/kg. The effect of geographical location on trace elements concentration in plants has been examined through determination of element in different species of Grewia tenax that collected from different locations in Darfur region. Most of the measured elements showed that there is no significant impact of locations on the difference of element contents.(Author)

  17. The Atlas of Chinese World Wide Web Ecosystem Shaped by the Collective Attention Flows.

    Directory of Open Access Journals (Sweden)

    Xiaodan Lou

    Full Text Available The web can be regarded as an ecosystem of digital resources connected and shaped by collective successive behaviors of users. Knowing how people allocate limited attention on different resources is of great importance. To answer this, we embed the most popular Chinese web sites into a high dimensional Euclidean space based on the open flow network model of a large number of Chinese users' collective attention flows, which both considers the connection topology of hyperlinks between the sites and the collective behaviors of the users. With these tools, we rank the web sites and compare their centralities based on flow distances with other metrics. We also study the patterns of attention flow allocation, and find that a large number of web sites concentrate on the central area of the embedding space, and only a small fraction of web sites disperse in the periphery. The entire embedding space can be separated into 3 regions(core, interim, and periphery. The sites in the core (1% occupy a majority of the attention flows (40%, and the sites (34% in the interim attract 40%, whereas other sites (65% only take 20% flows. What's more, we clustered the web sites into 4 groups according to their positions in the space, and found that similar web sites in contents and topics are grouped together. In short, by incorporating the open flow network model, we can clearly see how collective attention allocates and flows on different web sites, and how web sites connected each other.

  18. The Atlas of Chinese World Wide Web Ecosystem Shaped by the Collective Attention Flows.

    Science.gov (United States)

    Lou, Xiaodan; Li, Yong; Gu, Weiwei; Zhang, Jiang

    2016-01-01

    The web can be regarded as an ecosystem of digital resources connected and shaped by collective successive behaviors of users. Knowing how people allocate limited attention on different resources is of great importance. To answer this, we embed the most popular Chinese web sites into a high dimensional Euclidean space based on the open flow network model of a large number of Chinese users' collective attention flows, which both considers the connection topology of hyperlinks between the sites and the collective behaviors of the users. With these tools, we rank the web sites and compare their centralities based on flow distances with other metrics. We also study the patterns of attention flow allocation, and find that a large number of web sites concentrate on the central area of the embedding space, and only a small fraction of web sites disperse in the periphery. The entire embedding space can be separated into 3 regions(core, interim, and periphery). The sites in the core (1%) occupy a majority of the attention flows (40%), and the sites (34%) in the interim attract 40%, whereas other sites (65%) only take 20% flows. What's more, we clustered the web sites into 4 groups according to their positions in the space, and found that similar web sites in contents and topics are grouped together. In short, by incorporating the open flow network model, we can clearly see how collective attention allocates and flows on different web sites, and how web sites connected each other.

  19. Trace element analysis of soil type collected from the Manjung and central Perak

    Energy Technology Data Exchange (ETDEWEB)

    Azman, Muhammad Azfar, E-mail: m-azfar@nuclearmalaysia.gov.my; Hamzah, Suhaimi; Rahman, Shamsiah Abdul; Elias, Md Suhaimi; Abdullah, Nazaratul Ashifa; Hashim, Azian; Shukor, Shakirah Abd; Kamaruddin, Ahmad Hasnulhadi Che [Blok 18, Makmal Analisis Kimia (Aca/Bas), Agensi Nuklear Malaysia, 43000 Kajang, Selangor (Malaysia)

    2015-04-29

    Trace elements in soils primarily originated from their parent materials. Parents’ material is the underlying geological material that has been undergone different types of chemical weathering and leaching processes. Soil trace elements concentrations may be increases as a result of continuous input from various human activities, including power generation, agriculture, mining and manufacturing. This paper describes the Neutron Activation Analysis (NAA) method used for the determination of trace elements concentrations in part per million (ppm) present in the terrestrial environment soil in Perak. The data may indicate any contamination of trace elements contributed from human activities in the area. The enrichment factors were used to check if there any contamination due to the human activities (power plants, agricultural, mining, etc.) otherwise the values would serve as a baseline data for future study. The samples were collected from 27 locations of different soil series in the area at two different depths: the top soil (0-15cm) and the sub soil (15-30cm). The collected soil samples were air dried at 60°C and passed through 2 µm sieve. Instrumental Neutron Activation Analysis (NAA) has been used for the determination of trace elements. Samples were activated in the Nuclear Malaysia TRIGA Mark II reactor followed by gamma spectrometric analysis. By activating the stable elements in the samples, the elements can be determined from the intensities of gamma energies emitted by the respected radionuclides.

  20. Elemental analysis of airborne fine particles collected at the roadside of an arterial road

    International Nuclear Information System (INIS)

    Hirabayashi, M.

    2008-01-01

    Airborne particulate matter was collected at the intersection of Industrial Road in Kawasaki-city, Kanagawa, Japan using a 12-stage low-pressure impactor. High concentrations of airborne particulate matter have been observed in this area. The collected samples were analyzed for 34 elements by instrumental neutron activation analysis (INAA), and data on the elemental concentrations were obtained. High concentrations of fine particles of As, Br, Sb, V, and Zn were observed. It was further observed that these fine particles were originated predominantly from the wear of tires and brakes, and not from automobile exhaust emissions. (author)

  1. Survey of elemental concentrations in lichen samples collected from Sao Paulo State

    International Nuclear Information System (INIS)

    Saiki, M.; Horimoto, L.K.; Vasconcellos, M.B.A.; Coccaro, D.M.B.; Marcelli, M.P.

    2001-01-01

    Samples of the lichen Canoparmelia texana collected in seven different sites of Sao Paulo State and one site of the Parana State were analysed by neutron activation analysis in order to obtain information on the air quality in these regions and also to select a region of interest for the evaluation of baseline level of elements in lichen species. Concentrations of the elements Al, As, Br, Ca, Cd, Cl, Co, Cs, Fe, Hf, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Ti, Th, U, V, Zn and lanthanides were determined and a preliminary comparisons was made between the results obtained for samples collected in different sites. (author)

  2. Biomechanical implications of intraspecific shape variation in chimpanzee crania: moving towards an integration of geometric morphometrics and finite element analysis

    Science.gov (United States)

    Smith, Amanda L.; Benazzi, Stefano; Ledogar, Justin A.; Tamvada, Kelli; Smith, Leslie C. Pryor; Weber, Gerhard W.; Spencer, Mark A.; Dechow, Paul C.; Grosse, Ian R.; Ross, Callum F.; Richmond, Brian G.; Wright, Barth W.; Wang, Qian; Byron, Craig; Slice, Dennis E.; Strait, David S.

    2014-01-01

    In a broad range of evolutionary studies, an understanding of intraspecific variation is needed in order to contextualize and interpret the meaning of variation between species. However, mechanical analyses of primate crania using experimental or modeling methods typically encounter logistical constraints that force them to rely on data gathered from only one or a few individuals. This results in a lack of knowledge concerning the mechanical significance of intraspecific shape variation that limits our ability to infer the significance of interspecific differences. This study uses geometric morphometric methods (GM) and finite element analysis (FEA) to examine the biomechanical implications of shape variation in chimpanzee crania, thereby providing a comparative context in which to interpret shape-related mechanical variation between hominin species. Six finite element models (FEMs) of chimpanzee crania were constructed from CT scans following shape-space Principal Component Analysis (PCA) of a matrix of 709 Procrustes coordinates (digitized onto 21 specimens) to identify the individuals at the extremes of the first three principal components. The FEMs were assigned the material properties of bone and were loaded and constrained to simulate maximal bites on the P3 and M2. Resulting strains indicate that intraspecific cranial variation in morphology is associated with quantitatively high levels of variation in strain magnitudes, but qualitatively little variation in the distribution of strain concentrations. Thus, interspecific comparisons should include considerations of the spatial patterning of strains rather than focus only their magnitude. PMID:25529239

  3. A three-dimensional acoustic Boundary Element Method formulation with viscous and thermal losses based on shape function derivatives

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; Andersen, Peter Risby

    2018-01-01

    then be modeled with numerical methods that include losses. In recent years, versions of both the Finite Element Method (FEM) and the Boundary Element Method (BEM) including viscous and thermal losses have been developed. This paper deals with an improved formulation in three dimensions of the BEM with losses...... which avoids the calculation of tangential derivatives on the surface by finite differences used in a previous BEM implementation. Instead, the tangential derivatives are obtained from the element shape functions. The improved implementation is demonstrated using an oscillating sphere, where......Sound waves in fluids are subject to viscous and thermal losses, which are particularly relevant in the so-called viscous and thermal boundary layers at the boundaries, with thicknesses in the micrometer range at audible frequencies. Small devices such as acoustic transducers or hearing aids must...

  4. Essential and non-essential element concentrations in two sleeper shark species collected in arctic waters

    Energy Technology Data Exchange (ETDEWEB)

    McMeans, Bailey C. [Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4 (Canada); Borga, Katrine [Norwegian Institute for Water Research, P.O. Box 173, Kjelsas, N-0411 Oslo (Norway); Bechtol, William R. [Alaska Department of Fish and Game, Division of Commercial Fisheries, Anchorage, AK 99518-1599 (United States); Higginbotham, David [Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602-2152 (United States); Fisk, Aaron T. [Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4 (Canada)]. E-mail: afisk@uwindsor.ca

    2007-07-15

    A number of elements/metals have increased in arctic biota and are of concern due to their potential toxicity. Most studies on elements in the Arctic have focused on marine mammals and seabirds, but concentrations in the Greenland shark (Somniosus microcephalus) and Pacific sleeper shark (Somniosus pacificus), the only two shark species known to regularly inhabit arctic waters, have never been reported. To address this data gap, concentrations and patterns of 25 elements were analyzed in liver of Greenland sharks collected about Cumberland Sound (n = 24) and Pacific sleeper sharks collected about Prince William Sound (n = 14). Several non-essential elements differed between species/locations, which could suggest geographical exposure differences or ecological (e.g., diet) differences between the species. Certain essential elements also differed between the two sleeper sharks, which may indicate different physiological requirements between these closely related shark species, although information on such relationships are lacking for sharks and fish. - Patterns of essential and non-essential elements provide insight into sleeper shark biology and physiology.

  5. Essential and non-essential element concentrations in two sleeper shark species collected in arctic waters

    International Nuclear Information System (INIS)

    McMeans, Bailey C.; Borga, Katrine; Bechtol, William R.; Higginbotham, David; Fisk, Aaron T.

    2007-01-01

    A number of elements/metals have increased in arctic biota and are of concern due to their potential toxicity. Most studies on elements in the Arctic have focused on marine mammals and seabirds, but concentrations in the Greenland shark (Somniosus microcephalus) and Pacific sleeper shark (Somniosus pacificus), the only two shark species known to regularly inhabit arctic waters, have never been reported. To address this data gap, concentrations and patterns of 25 elements were analyzed in liver of Greenland sharks collected about Cumberland Sound (n = 24) and Pacific sleeper sharks collected about Prince William Sound (n = 14). Several non-essential elements differed between species/locations, which could suggest geographical exposure differences or ecological (e.g., diet) differences between the species. Certain essential elements also differed between the two sleeper sharks, which may indicate different physiological requirements between these closely related shark species, although information on such relationships are lacking for sharks and fish. - Patterns of essential and non-essential elements provide insight into sleeper shark biology and physiology

  6. Trace element analysis in ants collected in Japan, Finland and Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Kitao, K. [National Inst. of Radiological Sciences, Chiba (Japan)

    1992-12-31

    Particle induced x-ray emission has been used to determine the concentration of trace elements in ants (Formicidae). Scanning PIXE analysis was also used to determine the distribution of these elements. Samples of ants were collected from gardens, buildings or from the roadway in Japan. Finland and Sweden. The only pre-treatments were dusting and washing. In each run of experiments we used only one individual ant and have obtained the analytical results of a reasonable accuracy. We have detected chemical minor elements, i.e., Mn, Fe, Cu, Zn, Rb, Br and Sr. The PIXE, and scanning PIXE method proved to be useful and sensitive enough to measure trace elements in such small insects as ants. (author).

  7. Trace element analysis in ants collected in Japan, Finland and Sweden

    International Nuclear Information System (INIS)

    Kitao, K.

    1992-01-01

    Particle induced x-ray emission has been used to determine the concentration of trace elements in ants (Formicidae). Scanning PIXE analysis was also used to determine the distribution of these elements. Samples of ants were collected from gardens, buildings or from the roadway in Japan. Finland and Sweden. The only pre-treatments were dusting and washing. In each run of experiments we used only one individual ant and have obtained the analytical results of a reasonable accuracy. We have detected chemical minor elements, i.e., Mn, Fe, Cu, Zn, Rb, Br and Sr. The PIXE, and scanning PIXE method proved to be useful and sensitive enough to measure trace elements in such small insects as ants. (author)

  8. An investigation of shape memory alloys as actuating elements in aerospace morphing applications

    DEFF Research Database (Denmark)

    Karagiannis, Dimitrios; Stamatelos, Dimtrios; Kappatos, Vasileios

    2017-01-01

    Two innovative actuating concepts for aerospace morphing applications, based on Shape Memory Alloys (SMAs), are proposed. The first concept investigates a composite plate incorporating embedded SMA wires. A Nonlinear Auto Regressive with eXogenous excitation (NARX) model is proposed for controlling...

  9. Contribution of Shape Memory Alloys Elements in Designing Underwater Smart Structures

    Directory of Open Access Journals (Sweden)

    Daniel Amariei

    2007-10-01

    Full Text Available Shape memory alloys (SMA have generated a lot of new ideas in engineering. Application is however so far limited to clamps and springs. With respect to smart structures sensing as well as control has to be included. While sensing looks to be relatively feasible control is the big challenge. This paper describes some related a smart structure idea using SMAs and discusses the challenges which need to be solved before these ideas can be realised.

  10. Finite element analysis of the effect of loading curve shape on brain injury predictors

    OpenAIRE

    Post, Andrew; Hoshizaki, Thomas Blaine; Gilchrist, M. D.

    2012-01-01

    Prediction of traumatic and mild traumatic brain injury is an important factor in managing their prevention. Currently, the prediction of these injuries is limited to peak linear and angular acceleration loading curves derived from laboratory reconstructions. However it remains unclear as to what aspect of these loading curves contributes to brain tissue damage. This research will use the University College Dublin Brain Trauma Model (UCDBTM) to analyze three distinct loading curve shapes mean...

  11. Optimization of Linear Permanent Magnet (PM Generator with Triangular-Shaped Magnet for Wave Energy Conversion using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Aamir Hussain

    2016-06-01

    Full Text Available This paper presents the design optimization of linear permanent magnet (PM generator for wave energy conversion using finite element method (FEM. A linear PM generator with triangular-shaped magnet is proposed, which has higher electromagnetic characteristics, superior performance and low weight as compared to conventional linear PM generator with rectangular shaped magnet. The Individual Parameter (IP optimization technique is employed in order to optimize and achieve optimum performance of linear PM generator. The objective function, optimization variables; magnet angle,M_θ(∆ (θ, the pole-width ratio, P_w ratio(τ_p/τ_mz,, and split ratio between translator and stator, δ_a ratio(R_m/R_e, and constraints are defined. The efficiency and its main parts; copper and iron loss are computed using time-stepping FEM. The optimal values after optimization are presented which yields highest efficiency. Key

  12. Collection and preparation of bottom sediment samples for analysis of radionuclides and trace elements

    International Nuclear Information System (INIS)

    2003-07-01

    The publication is the first in a series of TECDOCs on sampling and sample handling as part of the IAEA support to improve reliability of nuclear analytical techniques (NATs) in Member State laboratories. The purpose of the document is to provide information on the methods for collecting sediments, the equipment used, and the sample preparation techniques for radionuclide and elemental analysis. The most appropriate procedures for defining the strategies and criteria for selecting sampling locations, for sample storage and transportation are also given. Elements of QA/QC and documentation needs for sampling and sediment analysis are discussed. Collection and preparation of stream and river bottom sediments, lake bottom sediments, estuary bottom sediments, and marine (shallow) bottom sediments are covered. The document is intended to be a comprehensive manual for the collection and preparation of bottom sediments as a prerequisite to obtain representative and meaningful results using NATs. Quality assurance and quality control (QA/QC) is emphasized as an important aspect to ensure proper collection, transportation, preservation, and analysis since it forms the basis for interpretation and legislation. Although there are many approaches and methods available for sediment analyses, the scope of the report is limited to sample preparation for (1) analysis of radionuclides (including sediment dating using radionuclides such as Pb-210 and Cs-137) and (2) analysis of trace, minor and major elements using nuclear and related analytical techniques such as NAA, XRF and PIXE

  13. Dielectric response of arbitrary-shaped clusters studied by the finite element method

    Czech Academy of Sciences Publication Activity Database

    Rychetský, Ivan; Klíč, Antonín

    2012-01-01

    Roč. 427, č. 1 (2012), s. 143-147 ISSN 0015-0193 R&D Projects: GA ČR GA202/09/0430 Institutional research plan: CEZ:AV0Z10100520 Keywords : effective permittivity * two-component composite * integral representation * finite element analysis Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.415, year: 2012

  14. Finite Element Analysis of the Random Response Suppression of Composite Panels at Elevated Temperatures using Shape Memory Alloy Fibers

    Science.gov (United States)

    Turner, Travis L.; Zhong, Z. W.; Mei, Chuh

    1994-01-01

    A feasibility study on the use of shape memory alloys (SMA) for suppression of the random response of composite panels due to acoustic loads at elevated temperatures is presented. The constitutive relations for a composite lamina with embedded SMA fibers are developed. The finite element governing equations and the solution procedures for a composite plate subjected to combined acoustic and thermal loads are presented. Solutions include: 1) Critical buckling temperature; 2) Flat panel random response; 3) Thermal postbuckling deflection; 4) Random response of a thermally buckled panel. The preliminary results demonstrate that the SMA fibers can completely eliminate the thermal postbuckling deflection and significantly reduce the random response at elevated temperatures.

  15. Reducing aberration effect of Fourier transform lens by modifying Fourier spectrum of diffractive optical element in beam shaping optical system.

    Science.gov (United States)

    Zhang, Fang; Zhu, Jing; Song, Qiang; Yue, Weirui; Liu, Jingdan; Wang, Jian; Situ, Guohai; Huang, Huijie

    2015-10-20

    In general, Fourier transform lenses are considered as ideal in the design algorithms of diffractive optical elements (DOEs). However, the inherent aberrations of a real Fourier transform lens disturb the far field pattern. The difference between the generated pattern and the expected design will impact the system performance. Therefore, a method for modifying the Fourier spectrum of DOEs without introducing other optical elements to reduce the aberration effect of the Fourier transform lens is proposed. By applying this method, beam shaping performance is improved markedly for the optical system with a real Fourier transform lens. The experiments carried out with a commercial Fourier transform lens give evidence for this method. The method is capable of reducing the system complexity as well as improving its performance.

  16. Composite Elements for Biomimetic Aerospace Structures with Progressive Shape Variation Capabilities

    Directory of Open Access Journals (Sweden)

    Alessandro Airoldi

    2016-07-01

    Full Text Available The paper presents some engineering solutions for the development of innovative aerodynamic surfaces with the capability of progressive shape variation. A brief introduction of the most significant issues related to the design of such morphing structures is provided. Thereafter, two types of structural solutions are presented for the design of internal compliant structures and flexible external skins. The proposed solutions exploit the properties and the manufacturing techniques of long fibre reinforced plastic in order to fulfil the severe and contradictory requirements related to the trade-off between morphing performance and load carrying capabilities.

  17. Determination of trace and toxic elements in marine sediments collected from the strait of Malacca, Malaysia

    International Nuclear Information System (INIS)

    Wee Boon Siong; Abdul Khalik Hj. Wood

    2007-01-01

    The Strait of Malacca has been a major route for international trade with heavy traffic of large vessels navigating through the narrow waterway everyday. Beside, the Strait of Malacca has some natural ecosystem which requires proper protection from human activities. Therefore, the Malaysian government has initiated a project to monitor the pollution level at the Strait of Malacca. As a result, sampling expeditions had been conducted to collect marine samples to be analyzed for trace and toxic elements as well as organic pollutions and radionuclides. The focus of this report is to determine trace and toxic element concentration in surface sediment samples collected from 18 sampling locations at the Strait of Malacca was reported. (author)

  18. Dragon bridge - the world largest dragon-shaped (ARCH steel bridge as element of smart city

    Directory of Open Access Journals (Sweden)

    Chinh Luong Minh

    2016-01-01

    Full Text Available Dragon Bridge - The world’s largest dragon-shaped steel bridge, with an installation cost of $85 million USD, features 6 lanes for two separate directions, 666 meters of undulating steel in the shape of a dragon in the Ly Dynasty, the symbol of prosperity in Vietnamese culture. This unique and beautifully lit bridge, which also breathes fire and sprays water. It’s the purposeful integration of the lighting hardware articulates the dragon’s form, and the fire-breathing dragon head. This project transcends the notion of monumental bridge with dynamic colour-changing lighting, creating an iconic sculpture in the skyline that is both reverent and whimsical. The signature feature of the bridge was the massive undulating support structure resembling a dragon flying over the river. The dragon is prominent in Vietnamese culture as a symbol of power and nobility. Dragon Bridge stands out as a model of innovation. It has received worldwide attention in the design community and from the global media for its unique arch support system. Dragon Bridge serves as an example of how aesthetic quality of a design can serve cultural, economic and functional purposes. The article presents design solutions of the object and the evaluation of the technical condition before putting the facility into service.

  19. Multi-element composition of historical lichen collections and bark samples, indicators of changing atmospheric conditions

    Science.gov (United States)

    Purvis, O. W.; Chimonides, P. D. J.; Jeffries, T. E.; Jones, G. C.; Rusu, A.-M.; Read, H.

    Thirty six element signatures were compared in historical Parmelia sulcata samples from the Natural History Museum herbarium collected over the period 1797-1967 with those recorded in the same species and tree bark sampled in 2000 from Burnham Beeches, lying 40 km west of London. Nineteen elements reached highest concentrations in herbarium samples, consistent with a pollution legacy and dust contamination in the herbarium. Healthy Parmelia sampled east and down-wind of London at a farm during peak SO 2 emissions in 1967 contained highest V, Ni, Zn, Cd, Se, Ge contents, supporting derivation from fuel combustion; the same sample was previously determined as having a low δ34S and high S and N contents. Lowest V, Co, Ni, Cu, Zn, Sn, Ba, Pb, Mo, Sb, Li, B, Cs, U, Th, Ga contents were recorded in a sample with a high δ34S and low S content collected in 1887 from a remote region from Ross-shire, Scotland. Se and Cd enrichment, never-the-less suggest a transboundary pollution influence. Lichen Pb concentrations from Burnham Beeches were amongst the lowest recorded in spite of lichens being collected close to roads. Herbarium samples help interpret changes in element deposition where few data exist, in spite of dust contamination.

  20. Simulation of Fluid Flow and Collection Efficiency for an SEA Multi-element Probe

    Science.gov (United States)

    Rigby, David L.; Struk, Peter M.; Bidwell, Colin

    2014-01-01

    Numerical simulations of fluid flow and collection efficiency for a Science Engineering Associates (SEA) multi-element probe are presented. Simulation of the flow field was produced using the Glenn-HT Navier-Stokes solver. Three-dimensional unsteady results were produced and then time averaged for the heat transfer and collection efficiency results. Three grid densities were investigated to enable an assessment of grid dependence. Simulations were completed for free stream velocities ranging from 85-135 meters per second, and free stream total pressure of 44.8 and 93.1 kilopascals (6.5 and 13.5 pounds per square inch absolute). In addition, the effect of angle of attack and yaw were investigated by including 5 degree deviations from straight for one of the flow conditions. All but one of the cases simulated a probe in isolation (i.e. in a very large domain without any support strut). One case is included which represents a probe mounted on a support strut within a finite sized wind tunnel. Collection efficiencies were generated, using the LEWICE3D code, for four spherical particle sizes, 100, 50, 20, and 5 micron in diameter. It was observed that a reduction in velocity of about 20% occurred, for all cases, as the flow entered the shroud of the probe. The reduction in velocity within the shroud is not indicative of any error in the probe measurement accuracy. Heat transfer results are presented which agree quite well with a correlation for the circular cross section heated elements. Collection efficiency results indicate a reduction in collection efficiency as particle size is reduced. The reduction with particle size is expected, however, the results tended to be lower than the previous results generated for isolated two-dimensional elements. The deviation from the two-dimensional results is more pronounced for the smaller particles and is likely due to the reduced flow within the protective shroud. As particle size increases differences between the two

  1. Study of magnetic field distribution in anisotropic single twin-boundary magnetic shape memory (MSM) element in actuators

    Science.gov (United States)

    Gabdullin, N.; Khan, S. H.

    2017-10-01

    Magnetic shape memory effect exhibited by certain alloys at room temperature is known for almost 20 years. The most studied MSM alloys are Ni-Mn-Ga alloys which exhibit up to 12% magnetic field-induced strain (change in shape) depending on microstructure. A multibillion cycle operation without malfunction along with their “smart” properties make them very promising for application in electromagnetic (EM) actuators and sensors. However, considerable twinning stress of MSM crystals resulting in magneto-mechanical hysteresis decreases the efficiency and output force of MSM actuators. Whereas twinning stress of conventional MSM crystals has been significantly decreased over the years, novel crystals with Type II twin boundaries (TBs) possess even lower twinning stress. Unfortunately, the microstructure of MSM crystals with very low twinning stress tends to be unstable leading to their rapid crack growth. Whilst this phenomenon has been studied experimentally, the magnetic field distribution in anisotropic single twin-boundary MSM elements has not been considered yet. This paper analyses the magnetic field distribution in two-variant single twin-boundary MSM elements and discusses its effects on magnetic field-induced stress acting on the twin boundary.

  2. Pancharatnam-Berry phase optical elements fabricated by 3D printing for shaping terahertz beams

    Science.gov (United States)

    Hernandez-Serrano, Arturo I.; Castro-Camus, Enrique; Lopez-Mago, Dorilian

    2017-08-01

    The design, fabrication and characterization of space-variant Pancharatnam-Berry phase optical elements is presented for the terahertz regime (THz). These PBOEs are made out of polystyrene and were fabricated by commercially available three-dimensional printers, providing a simple and inexpensive solution for the generation of THz vector beams. The polarization structure was characterized by using a THz time-domain imaging system. These devices can find applications in future THz technologies and provide new tools for the study of polarization morphologies

  3. The role of size constancy for the integration of local elements into a global shape

    Directory of Open Access Journals (Sweden)

    Johannes eRennig

    2013-07-01

    Full Text Available Visual perception depends on the visual context and is likely to be influenced by size constancy, which predicts a size and distance invariant perception of objects. However, size constancy can also result in optical illusions that allow the manipulation of the perceived size. We thus asked whether the integration of local elements into a global object can be influenced by manipulations of the visual context and size constancy? A set of stimuli was applied in healthy individuals that took advantage of the ‘Kanizsa’ illusion, in which three circles with open wedges oriented towards a center point are placed to form an illusionary perception of a triangle. In addition, a 3D-perspective view was implemented in which the global target (‘Kanizsa’ triangle was placed in combination with several distractor circles either in a close or a distant position. Subjects were engaged in a global recognition task on the location of the ‘Kanizsa’ triangle. Global recognition of ‘Kanizsa’ triangles improved with a decreasing length of the illusory contour. Interestingly, recognition of ‘Kanizsa’ triangles decreased when they were perceived as if they were located further away. We conclude that the integration of local elements into a global object is dependent on the visual context and dominated by size constancy.

  4. Mercury and trace elements in cloud water and precipitation collected on Mt. Mansfield, Vermont.

    Science.gov (United States)

    Malcolm, Elizabeth G; Keeler, Gerald J; Lawson, Sean T; Sherbatskoy, Timothy D

    2003-08-01

    The lack of high quality measurements of Hg and trace elements in cloud and fog water led to the design of a new collector for clean sequential sampling of cloud and fog water. Cloud water was collected during nine non-precipitating cloud events on Mt. Mansfield, VT in the northeastern USA between August 1 and October 31, 1998. Sequential samples were collected during six of these events. Mercury cloud water concentrations ranged from 7.5 to 71.8 ng l(-1), with a mean of 24.8 ng l(-1). Liquid water content explained about 60% of the variability in Hg cloud concentrations. Highest Hg cloud water concentrations were found to be associated with transport from the Mid-Atlantic and Ohio River Valley, and lowest concentrations with transport from the north of Mt. Mansfield out of Canada. Twenty-nine event precipitation samples were collected during the ten-week cloud sampling period near the base of Mt. Mansfield as part of a long-term deposition study. The Hg concentrations of cloud water were similar to, but higher on average (median of 12.5 ng l(-1)) than Hg precipitation concentrations (median of 10.5 ng l(-1)). Cloud and precipitation samples were analyzed for fifteen trace elements including Mg, Cu, Zn, As, Cd and Pb by ICP-MS. Mean concentrations were higher in cloud water than precipitation for elements with predominately anthropogenic, but not crustal origin in samples from the same source region. One possible explanation is greater in-cloud scavenging of crustal elements in precipitating than non-precipitating clouds, and greater below-cloud scavenging of crustal than anthropogenic aerosols.

  5. Common data elements collected among universities for sport-related concussion studies.

    Science.gov (United States)

    Yang, Jingzhen; Peek-Asa, Corinne; Noble, James M; Torner, James; Schmidt, Paul; Cooper, Martha L

    2018-02-12

    Universities are increasingly implementing programs to effectively respond to and manage sport-related concussions (SRCs). One such effort is to develop common data elements (CDEs) and standardize data collection methods. The objectives of this study were to describe CDEs currently collected by Big Ten and Ivy League universities for SRC studies, and to compare the data collected with the core CDEs recommended by the National Institute of Neurological Disorders and Stroke (NINDS). We conducted an anonymous cross-sectional online survey among medical staff at the 14 Big Ten and 8 Ivy League universities (one per university) between September and October 2015. The survey instrument, including 9 questions corresponding to the concussion data collected before, during, and after a concussion, was developed and pilot-tested before field use. We analyzed patterns of the concussion CDEs being collected, including when, what, and how the data were collected and stored, and compared them with the NINDS' recommended core CDEs. A total of 19 out of 22 universities were included, with 13 from Big Ten and 6 from Ivy-League universities. All 19 participating universities currently collected concussion data with athletes before, during, and after a concussion. Great similarities in data collection were observed at baseline and acutely post-concussion across participating universities. All 19 universities collected at least one of the ten recommended acute symptoms checklists, and 18 universities collected one of the four recommended core neuropsychological function cognitive measures. However, CDEs in the sub-acute and chronic timeframes were limited, with only 9 (47%) universities collecting post-concussion short to long term outcome data. While over 60% of universities collected and stored concussion data electronically, only 17% to 42% of data collected were readily available for research. Significant inter-institutional similarities in acute concussion CDEs were found. Further

  6. Clostridium botulinum group III: a group with dual identity shaped by plasmids, phages and mobile elements

    Directory of Open Access Journals (Sweden)

    Håfström Therese

    2011-04-01

    Full Text Available Abstract Background Clostridium botulinum strains can be divided into four physiological groups that are sufficiently diverged to be considered as separate species. Here we present the first complete genome of a C. botulinum strain from physiological group III, causing animal botulism. We also compare the sequence to three new draft genomes from the same physiological group. Results The 2.77 Mb chromosome was highly conserved between the isolates and also closely related to that of C. novyi. However, the sequence was very different from the human C. botulinum group genomes. Replication-directed translocations were rare and conservation of synteny was high. The largest difference between C. botulinum group III isolates occurred within their surprisingly large plasmidomes and in the pattern of mobile elements insertions. Five plasmids, constituting 13.5% of the total genetic material, were present in the completed genome. Interestingly, the set of plasmids differed compared to other isolates. The largest plasmid, the botulinum-neurotoxin carrying prophage, was conserved at a level similar to that of the chromosome while the medium-sized plasmids seemed to be undergoing faster genetic drift. These plasmids also contained more mobile elements than other replicons. Several toxins and resistance genes were identified, many of which were located on the plasmids. Conclusions The completion of the genome of C. botulinum group III has revealed it to be a genome with dual identity. It belongs to the pathogenic species C. botulinum, but as a genotypic species it should also include C. novyi and C. haemolyticum. The genotypic species share a conserved chromosomal core that can be transformed into various pathogenic variants by modulation of the highly plastic plasmidome.

  7. Clostridium botulinum group III: a group with dual identity shaped by plasmids, phages and mobile elements.

    Science.gov (United States)

    Skarin, Hanna; Håfström, Therese; Westerberg, Josefina; Segerman, Bo

    2011-04-12

    Clostridium botulinum strains can be divided into four physiological groups that are sufficiently diverged to be considered as separate species. Here we present the first complete genome of a C. botulinum strain from physiological group III, causing animal botulism. We also compare the sequence to three new draft genomes from the same physiological group. The 2.77 Mb chromosome was highly conserved between the isolates and also closely related to that of C. novyi. However, the sequence was very different from the human C. botulinum group genomes. Replication-directed translocations were rare and conservation of synteny was high. The largest difference between C. botulinum group III isolates occurred within their surprisingly large plasmidomes and in the pattern of mobile elements insertions. Five plasmids, constituting 13.5% of the total genetic material, were present in the completed genome. Interestingly, the set of plasmids differed compared to other isolates. The largest plasmid, the botulinum-neurotoxin carrying prophage, was conserved at a level similar to that of the chromosome while the medium-sized plasmids seemed to be undergoing faster genetic drift. These plasmids also contained more mobile elements than other replicons. Several toxins and resistance genes were identified, many of which were located on the plasmids. The completion of the genome of C. botulinum group III has revealed it to be a genome with dual identity. It belongs to the pathogenic species C. botulinum, but as a genotypic species it should also include C. novyi and C. haemolyticum. The genotypic species share a conserved chromosomal core that can be transformed into various pathogenic variants by modulation of the highly plastic plasmidome.

  8. [Impact of specimen collection and storage consumable products on trace element quantitative analysis].

    Science.gov (United States)

    Song, Yan-shuang; Gu, Yong-en; Ba, Te; Zhai, Min; Pu, Ji; Shen, Zhen-lin; Tang, Shi-chuan; Jia, Guang

    2012-07-01

    This study aimed to explore the impact of specimen collection and storage consumable products on trace element quantitative analysis. Devices and consumable products of different brands used in specimen collection or storage were selected and treated separately as below:urine collection and storage tubes (Brand A, B, C and D, 2 samples for each brand) were treated with 1% of HNO(3) volume fraction for 2 - 4 h; blood taking device (Brand O, P and Q, 3 samples for each brand) were used for ultra-pure water samples collecting as simulation of blood sampling;dust sampling filters (Brand X, Y and Z, 2 samples for each brand) were cold digested by nitric acid for 12 h, followed by microwave digestion. Then cadmium, cobalt, chromium, copper, iron, manganese, molybdenum, nickel, lead, selenium, stannum, titanium, vanadium and zinc concentrations in the solutions obtained during the course of collect or storage were quantified by inductively coupled plasma mass spectrometer. For the urine collection and storage consumable products, background values of elements were described as mean of parellel samples. The consentration of 14 quantified elements were relatively low for 5 ml cryogenic vials (brand B) with background values range of 0.001 - 0.350 ng/ml. The background values of copper of 50 ml centrifuge tubes (brand A), chromium of 5 ml cryogenic vials (brand C) and zinc of 1.5 ml centrifuge tubes (brand D) were relatively high, which were 1.900, 1.095 and 1.368 ng/ml, respectively. Background values of elements in blood sampling devices were described as x(-) ± s. Background values of chromium for brand O, P and Q were (0.120 ± 0.017), (0.337 ± 0.093) and (0.360 ± 0.035) ng/ml; for copper were (0.050 ± 0.001), (0.017 ± 0.012) and (0.103 ± 0.015) ng/ml; for lead were (0.057 ± 0.072), (0.183 ± 0.118) and (0.347 ± 0.006) ng/ml; for titanium were (7.883 ± 0.145), (8.863 ± 0.190) and (8.613 ± 0.274) ng/ml; zinc were (2.240 ± 0.573), (42.140 ± 22.756) and (8

  9. Trace Elements Speciation of Submicron Particulate Matter (PM1 Collected in the Surroundings of Power Plants

    Directory of Open Access Journals (Sweden)

    Elwira Zajusz-Zubek

    2015-10-01

    Full Text Available This study reports the concentrations of PM1 trace elements (As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Sb and Se content in highly mobile (F1, mobile (F2, less mobile (F3 and not mobile (F4 fractions in samples that were collected in the surroundings of power plants in southern Poland. It also reports source identification by enrichment factors (EF and a principal component analysis (PCA. There is limited availability of scientific data concerning the chemical composition of dust, including fractionation analyses of trace elements, in the surroundings of power plants. The present study offers important results in order to fill this data gap. The data collected in this study can be utilized to validate air quality models in this rapidly developing area. They are also crucial for comparisons with datasets from similar areas all over the world. Moreover, the identification of the bioavailability of selected carcinogenic and toxic elements in the future might be used as output data for potential biological and population research on risk assessment. This is important in the context of air pollution being hazardous to human health.

  10. Trace Elements Speciation of Submicron Particulate Matter (PM1) Collected in the Surroundings of Power Plants.

    Science.gov (United States)

    Zajusz-Zubek, Elwira; Kaczmarek, Konrad; Mainka, Anna

    2015-10-16

    This study reports the concentrations of PM1 trace elements (As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Sb and Se) content in highly mobile (F1), mobile (F2), less mobile (F3) and not mobile (F4) fractions in samples that were collected in the surroundings of power plants in southern Poland. It also reports source identification by enrichment factors (EF) and a principal component analysis (PCA). There is limited availability of scientific data concerning the chemical composition of dust, including fractionation analyses of trace elements, in the surroundings of power plants. The present study offers important results in order to fill this data gap. The data collected in this study can be utilized to validate air quality models in this rapidly developing area. They are also crucial for comparisons with datasets from similar areas all over the world. Moreover, the identification of the bioavailability of selected carcinogenic and toxic elements in the future might be used as output data for potential biological and population research on risk assessment. This is important in the context of air pollution being hazardous to human health.

  11. Shaping skeletal growth by modular regulatory elements in the Bmp5 gene.

    Directory of Open Access Journals (Sweden)

    Catherine Guenther

    2008-12-01

    Full Text Available Cartilage and bone are formed into a remarkable range of shapes and sizes that underlie many anatomical adaptations to different lifestyles in vertebrates. Although the morphological blueprints for individual cartilage and bony structures must somehow be encoded in the genome, we currently know little about the detailed genomic mechanisms that direct precise growth patterns for particular bones. We have carried out large-scale enhancer surveys to identify the regulatory architecture controlling developmental expression of the mouse Bmp5 gene, which encodes a secreted signaling molecule required for normal morphology of specific skeletal features. Although Bmp5 is expressed in many skeletal precursors, different enhancers control expression in individual bones. Remarkably, we show here that different enhancers also exist for highly restricted spatial subdomains along the surface of individual skeletal structures, including ribs and nasal cartilages. Transgenic, null, and regulatory mutations confirm that these anatomy-specific sequences are sufficient to trigger local changes in skeletal morphology and are required for establishing normal growth rates on separate bone surfaces. Our findings suggest that individual bones are composite structures whose detailed growth patterns are built from many smaller lineage and gene expression domains. Individual enhancers in BMP genes provide a genomic mechanism for controlling precise growth domains in particular cartilages and bones, making it possible to separately regulate skeletal anatomy at highly specific locations in the body.

  12. Analysis of trace elements in airborne particulate matters collected in Ankara, Turkey by TXRF

    Directory of Open Access Journals (Sweden)

    Durukan I.

    2013-04-01

    Full Text Available The main focus point of the presented study was the assessment of atmospheric burden of particulate matter and toxic trace metals in the atmosphere of Ankara, Turkey. For this purpose, outdoor samplings were accomplished in the capital city, Ankara. The types of filters, sample collection and sample preparation methods were investigated and optimized. Analyses were provided by the total reflection X-ray fluorescence (TXRF spectroscopic technique in Germany. Spatial and temporal variations of air particulate matter (APM levels in the city were examined. In some stations, APM sampled in according to their size distribution such as PM10 and PM2.5. Elemental characterization of size distributed PM were achieved and evaluated. It was detected that the elements mainly originated from soil in Beytepe station, from soil and solid fuel usage in Kayas station and from traffic and a variety of human activities in Sıhhiye station in air samplings. While the elements of natural origin observed in PM10 fraction, the elements from traffic and human activities were in PM2.5. Eventually, enrichment calculations were performed in order to identify the pollution sources.

  13. Collective strong coupling with homogeneous Rabi frequencies using a 3D lumped element microwave resonator

    Energy Technology Data Exchange (ETDEWEB)

    Angerer, Andreas, E-mail: andreas.angerer@tuwien.ac.at; Astner, Thomas; Wirtitsch, Daniel; Majer, Johannes, E-mail: johannes.majer@tuwien.ac.at [Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna (Austria); Sumiya, Hitoshi [Sumitomo Electric Industries Ltd., Itami 664-001 (Japan); Onoda, Shinobu [Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Isoya, Junichi [Research Centre for Knowledge Communities, University of Tsukuba, 1-2 Kasuga, Tsukuba, Ibaraki 305-8550 (Japan); Putz, Stefan [Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna (Austria); Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)

    2016-07-18

    We design and implement 3D-lumped element microwave cavities that spatially focus magnetic fields to a small mode volume. They allow coherent and uniform coupling to electron spins hosted by nitrogen vacancy centers in diamond. We achieve large homogeneous single spin coupling rates, with an enhancement of more than one order of magnitude compared to standard 3D cavities with a fundamental resonance at 3 GHz. Finite element simulations confirm that the magnetic field distribution is homogeneous throughout the entire sample volume, with a root mean square deviation of 1.54%. With a sample containing 10{sup 17} nitrogen vacancy electron spins, we achieve a collective coupling strength of Ω = 12 MHz, a cooperativity factor C = 27, and clearly enter the strong coupling regime. This allows to interface a macroscopic spin ensemble with microwave circuits, and the homogeneous Rabi frequency paves the way to manipulate the full ensemble population in a coherent way.

  14. Elemental composition of atmospheric aerosols collected during episodic air pollution events in Japan

    International Nuclear Information System (INIS)

    Kasahara, M.; Choi, K.C.; Takahashi, K.

    1992-01-01

    More than 3,000 aerosol samples have been collected since 1986 in Kyoto under various meteorological and environmental conditions, including episodic air pollution events such as heavy air pollution, Kosa dust, very clean air, etc. The elemental concentrations of these aerosol samples were determined by PIXE techniques, and elemental concentration data were used to estimate a source contribution of aerosols by applying a receptor model. The concentrations of Si, K, Ca, Ti and Fe in both coarse and fine fractions increased tremendously at Kosa event. The maximum source contribution of soil dust amounted to 140 μg/m 3 for a six hour average during a Kosa event. On the other hand, the concentrations of S, Zn, Pb and Cu in the fine fraction increased remarkably during heavy air pollution and photochemical smog events. (author)

  15. Bioaccumulation of Some Metallic Elements in Eddible Textrue of Shrimp Penaeus semisulcatus Collected from Persian Gulf

    Directory of Open Access Journals (Sweden)

    Behrooz Akbari-adergani

    2014-08-01

    Full Text Available Background: Today the consequences of taking metal ions especially heavy metals on human health and the environment is of great interest, especially for aquatic food products. The main aim of this scientific and applied research was to measure, some ionic metals’ concentration (i.e. Ni, Fe, V, Co, Cr, Ag, Cd, Li and Ba in Shrimp Penaeus semisulcatus collected from Persian Gulf. Materials and Methods: In this research twenty one samples of Shrimp Penaeus semisulcatus from seven regional fishing ports in Bandar Bushehr, Bandar Mahshahr and Bandar Abbass were collected and transferred to the laboratory in an ice box immediately. After sample preparation according to the AOAC method, each sample was introduced into the inductively coupled plasma atomic emission spectrometer (ICP-OES for determination of the metallic elements’ concentration. Results: The results showed that the average concentration of all elements except of vanadium in the muscle of shrimp was higher than the skin. Statistical analysis showed significant differences in the mean of cobalt and lithium accumulation in the skin and muscle of shrimp (P <0/05. Also mean concentration of metals measured in the muscle and skin of shrimps collected from Bushehr have the highest amount of metallic pollution compared to the other two fishing regions which could be a sign of potential contamination of this aquatic area. Conclusion : The comparison of mean concentration in muscle of collected shrimps from Persian Gulf with the WHO recommended guidlines showed that the concentration of metallic elements are lower than the WHO allowable limits and there is no concern regarding consumption of these products.

  16. Trace element analysis of the Otani Collection's Dunhuang and Turfan manuscripts by PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Kohno, M.; Yoshida, K.; Moritani, K.; Norizawa, K. [Department of Nuclear Engineering, Kyoto Univ., Sakyo, Kyoto (Japan); Enami, K.; Kasajima, H. [Ryukoku Univ., Department of Mechanical and System Engineering, Otsu, Shiga (Japan); Ueyama, D. [Ryukoku Univ., Faculty of Intercultural Communication, Otsu, Shiga (Japan); Takada, J.; Matsushita, R. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst

    1999-07-01

    In order to classify the Otani Collection's Dunhuang and Turfan manuscripts, their trace elements were analyzed by PIXE. The paper samples of these manuscripts were fallen off when they were photographed for a CD-ROM catalog. These samples were very small and their size was less than several millimeters. In addition, some paper fragments dating from the late Edo-era of Japan and the late Qing Dynasty of China, and modern Japanese handmade paper were analyzed using PIXE and NAA. Quite interesting results were obtained when analyzing the trace elements - Na, Mg, Al, Si, S, Cl, K, Ca, Sc, Mn, Fe, Cu, Zn, As, Br, Sr, Ba, Pb, La, Sm. It was found that Dunhuang and Turfan papers of the Otani Collection were characterized by its highest iron and bromine content. The reason of the highest iron content probably originates in their making process and/or depends on their preservative environment. On the other hand, it became clear as for the highest bromine content that the origin is from fumigation of methyl bromide. (author)

  17. Trace element concentrations in barramundi (Lates calcarifer) collected along the coast of Vietnam

    International Nuclear Information System (INIS)

    Tu, Nguyen Phuc Cam; Ha, Nguyen Ngoc; Haruta, Shinsuke; Takeuchi, Ichiro

    2014-01-01

    Highlights: • We analyzed 23 trace elements in barramundi collected along the coast of Vietnam. • Isotope signatures (δ 15 N and δ 13 C) helped us track the feeding habitats of barramundi. • We found clear geographic zone-dependent differences for Mn, As, Sr and Tl. • Consumption of barramundi may be safe for Vietnamese people. - Abstract: We determined concentrations of 23 trace elements (TEs), and stable carbon and nitrogen isotope (δ 13 C and δ 15 N) signatures in barramundi (Lates calcarifer) specimens collected along the coast of Vietnam in the Northern (NCZ), Central (CCZ) and Southern (SCZ) zones in the period 2007–2010. A combination of δ 13 C and δ 15 N signatures provided insight into ontogenetic shifts in barramundi foraging choices. There were clear zone-dependent differences in Mn, As, Sr and Tl concentrations; levels of Tl were highest in the NCZ, As in the CCZ, and Mn and Sr in the SCZ. Lowest concentrations of Rb occurred in the NCZ, Bi was lowest in the CCZ, and Cd and Cs were lowest in the SCZ. δ 15 N values significantly increased with increasing Zn, Se, Sn and Cs. Concentrations of TEs in barramundi from Vietnam were below worldwide guidelines for human consumption

  18. Heat Transfer Enhancement in a Solar Air Heater with Roughened Duct Having Arc-Shaped Elements as Roughness Element on the Absorber Plate

    Science.gov (United States)

    Singh, Anil Prakash; Goel, Varun; Vashishtha, Siddhartha; Kumar, Amit

    2016-07-01

    An experimental study has been carried out for the heat transfer and friction characteristics for arc shaped roughness element used in solar air heaters. Duct has an aspect ratio (W/H) of 11, relative roughness pitch (p/e) range of 4-16, relative roughness height (e/D) range of 0.027-0.045, Reynolds number ( Re) range of 2200-22,000 and arc angle (α) was kept constant at 60°. The effects of Re, relative roughness pitch (p/e) and relative roughness height (e/D) on heat transfer and friction factor have been discussed. The results obtained for Nusselt number and friction factor has been compared with smooth solar air heater to see the enhancement in heat transfer and friction factor and it is found out that considerable enhancement takes place in case of heat transfer as well as in friction factor. Correlations were also developed for Nusselt number and friction factor. Thermo-hydraulic performance parameter is also calculated for the same.

  19. 78 FR 13350 - Proposed Collection; Comment Request Healthy Communities Study: How Communities Shape Children's...

    Science.gov (United States)

    2013-02-27

    ... Use of Information Collection: The HCS will address the need for a cross-cutting national study of... programs/policies related to nutrition, physical activity, and weight of children), food service personnel...

  20. Metadata Effectiveness in Internet Discovery: An Analysis of Digital Collection Metadata Elements and Internet Search Engine Keywords

    Science.gov (United States)

    Yang, Le

    2016-01-01

    This study analyzed digital item metadata and keywords from Internet search engines to learn what metadata elements actually facilitate discovery of digital collections through Internet keyword searching and how significantly each metadata element affects the discovery of items in a digital repository. The study found that keywords from Internet…

  1. Concentrations of radiocesium and stable elements in different parts of pine tree collected in Chernobyl area

    International Nuclear Information System (INIS)

    Yoshida, Satoshi; Watanabe, Masumi; Suzuki, Akira; Linkov, Igor; Dvornik, Alexander; Zhuchenko, Tatiana

    2007-01-01

    Radial distributions of 137 Cs and related stable elements in a pine tree collected in Chernobyl contaminated area in Belarus were determined, in order to get basic information for dose estimation of pine tree. The concentration of 137 Cs in annual tree rings was the highest in cambium, and decreased sharply toward inside. The highest concentration of 137 Cs in cambium suggests the highest radiation dose to growing part of wood. Distribution of stable Cs was similar as that of 137 Cs, and the 137 Cs/stable Cs ratio was almost constant, indicating the equilibrium of Chernobyl 137 Cs with stable Cs in the pine wood. The similar distributions as Cs were observed for K and Rb. (author)

  2. An investigation of fabric and of particle shape in railway ballast using X-ray CT and the discrete element method

    OpenAIRE

    Ahmed, S.

    2014-01-01

    The mechanical behaviour of uncemented granular matter is influenced by the grain shape (i.e. form, angularity and concavity) and the material’s fabric (i.e. the spatial arrangement of particles and contacts). Discrete element modelling has been used in the past to compare different shaped particles (e.g. spheres, ellipsoids, etc.) but without any clear quantitative link to the shape of real materials. Existing methods of direct observation of fabric are restricted to sands (i.e. in the sub-m...

  3. The collective diffusion coefficient as a shape detector of the surface energy landscape

    Science.gov (United States)

    Mińkowski, Marcin; Załuska–Kotur, Magdalena A.

    2018-01-01

    The general expression for the diffusion coefficient for a dense, interacting particle system moving through a one-dimensional non-homogeneous energy potential is derived. Based on this expression, it is shown that the diffusion coefficient as a function of density depends to a great extent on the shape of the energy landscape. The presence of other particles affects the diffusion coefficient in another way as they pass through the same energy barriers, but set in a different order. The obtained result comes from a variational approach to diffusion and the interactions are taken into account using the transfer-matrix method. Interactions impact on the dynamics of the system, both by changing the equilibrium probabilities of the occupied states and by changing the barriers for the particle jumps. Several examples of diffusion in different energy potentials are presented and the dependence of the diffusion coefficient on potential and interactions is discussed.

  4. Reconstructing or Deconstructing Labor Archives? Shaping Labor Collection Development in an Uncertain Future

    Science.gov (United States)

    Quigel, James P., Jr.

    2005-01-01

    Labor archival programs confront numerous challenges to remain viable in a changing academic environment and institutional culture. The marketing of higher education, the anti-union stance of some university administrations, and the transition of labor studies programs create a less-than-benign environment for labor collection development…

  5. Tree resin composition, collection behavior and selective filters shape chemical profiles of tropical bees (Apidae: Meliponini).

    Science.gov (United States)

    Leonhardt, Sara D; Schmitt, Thomas; Blüthgen, Nico

    2011-01-01

    The diversity of species is striking, but can be far exceeded by the chemical diversity of compounds collected, produced or used by them. Here, we relate the specificity of plant-consumer interactions to chemical diversity applying a comparative network analysis to both levels. Chemical diversity was explored for interactions between tropical stingless bees and plant resins, which bees collect for nest construction and to deter predators and microbes. Resins also function as an environmental source for terpenes that serve as appeasement allomones and protection against predators when accumulated on the bees' body surfaces. To unravel the origin of the bees' complex chemical profiles, we investigated resin collection and the processing of resin-derived terpenes. We therefore analyzed chemical networks of tree resins, foraging networks of resin collecting bees, and their acquired chemical networks. We revealed that 113 terpenes in nests of six bee species and 83 on their body surfaces comprised a subset of the 1,117 compounds found in resins from seven tree species. Sesquiterpenes were the most variable class of terpenes. Albeit widely present in tree resins, they were only found on the body surface of some species, but entirely lacking in others. Moreover, whereas the nest profile of Tetragonula melanocephala contained sesquiterpenes, its surface profile did not. Stingless bees showed a generalized collecting behavior among resin sources, and only a hitherto undescribed species-specific "filtering" of resin-derived terpenes can explain the variation in chemical profiles of nests and body surfaces from different species. The tight relationship between bees and tree resins of a large variety of species elucidates why the bees' surfaces contain a much higher chemodiversity than other hymenopterans.

  6. Tree Resin Composition, Collection Behavior and Selective Filters Shape Chemical Profiles of Tropical Bees (Apidae: Meliponini)

    Science.gov (United States)

    Leonhardt, Sara D.; Schmitt, Thomas; Blüthgen, Nico

    2011-01-01

    The diversity of species is striking, but can be far exceeded by the chemical diversity of compounds collected, produced or used by them. Here, we relate the specificity of plant-consumer interactions to chemical diversity applying a comparative network analysis to both levels. Chemical diversity was explored for interactions between tropical stingless bees and plant resins, which bees collect for nest construction and to deter predators and microbes. Resins also function as an environmental source for terpenes that serve as appeasement allomones and protection against predators when accumulated on the bees' body surfaces. To unravel the origin of the bees' complex chemical profiles, we investigated resin collection and the processing of resin-derived terpenes. We therefore analyzed chemical networks of tree resins, foraging networks of resin collecting bees, and their acquired chemical networks. We revealed that 113 terpenes in nests of six bee species and 83 on their body surfaces comprised a subset of the 1,117 compounds found in resins from seven tree species. Sesquiterpenes were the most variable class of terpenes. Albeit widely present in tree resins, they were only found on the body surface of some species, but entirely lacking in others. Moreover, whereas the nest profile of Tetragonula melanocephala contained sesquiterpenes, its surface profile did not. Stingless bees showed a generalized collecting behavior among resin sources, and only a hitherto undescribed species-specific “filtering” of resin-derived terpenes can explain the variation in chemical profiles of nests and body surfaces from different species. The tight relationship between bees and tree resins of a large variety of species elucidates why the bees' surfaces contain a much higher chemodiversity than other hymenopterans. PMID:21858119

  7. Accumulation of radiocesium and trace elements in mushrooms collected from Japanese forests

    International Nuclear Information System (INIS)

    Yoshida, S.; Muramatsu, Y.; Ban-Nai, T.

    1996-01-01

    Concentrations of 137 Cs, 134 Cs and 40 K for 124 mushroom species (284 samples) collected from Japanese forests during 1989 to 1991 were studied. The levels of 137 Cs m mushrooms varied very widely ranging from 40 K were relatively constant. The median concentrations of 137 Cs and 40 K were 53 and 1180 Bq/kg (dry wt), respectively. The 134 Cs discharged through the Chernobyl accident was detected only in 33 mushroom samples. The proportions of 137 Cs originating from the Chernobyl accident m these mushrooms were in the range 137 Cs concentrations in mycorrhizal fungi tended to be higher than those in saprophytes. The concentrations in many mushrooms reflected the layers m which their mycelia were growing. In addition to the radionuclides, many stable elements including stable Cs in mushroom and soil samples were determined. A good correlation between 137 Cs and stable Cs was observed for 33 mushrooms collected from a pine forest on sandy soil near coast in Tokai-mura, Ibaraki, indicating that mushroom available Cs is recycling in the pine forest with the constant 137 Cs/stable Cs ratio. Accumulations from soil to mushrooms were observed for Cd, Rb, Zn, Cu. Cs, K, Mg, Mn, Ni and Tl. Through cultivation experiments in flasks using radiotracers, 137 Cs, 65 Zn and 54 Mn were observed to be accumulated in mushrooms. (author)

  8. A coupled kinetic Monte Carlo–finite element mesoscale model for thermoelastic martensitic phase transformations in shape memory alloys

    International Nuclear Information System (INIS)

    Chen, Ying; Schuh, Christopher A.

    2015-01-01

    A mesoscale modeling framework integrating thermodynamics, kinetic Monte Carlo (KMC) and finite element mechanics (FEM) is developed to simulate displacive thermoelastic transformations between austenite and martensite in shape memory alloys (SMAs). The model is based on a transition state approximation for the energy landscape of the two phases under loading or cooling, which leads to the activation energy and rate for transformation domains incorporating local stress states. The evolved stress state after each domain transformation event is calculated by FEM, and is subsequently used in the stochastic KMC algorithm to determine the next domain to transform. The model captures transformation stochasticity, and predicts internal phase and stress distributions and evolution throughout the entire incubation, nucleation and growth process. It also relates the critical transformation stresses or temperatures to internal activation energies. It therefore enables quantitative exploration of transformation dynamics and transformation–microstructure interactions. The model is used to simulate superelasticity (mechanically induced transformation) under both load control and strain control in single-crystal SMAs under uniaxial tension

  9. Imaging with a single-element forward-looking steerable IVUS catheter using optical shape sensing (Conference Presentation)

    Science.gov (United States)

    Janjic, Jovana; Mastik, Frits; Leistikow, Merel; Bosch, Johannes G.; van der Steen, Antonius F. W.; van Soest, Gijs

    2017-03-01

    Complex intravascular lesions, such as chronic total occlusions (CTOs), require forward-looking imaging. We propose to use a 25 MHz single-element transducer and an optical shape sensing (OSS) fiber integrated into a steerable catheter to achieve intravascular imaging in a forward-looking approach. A tissue-mimicking phantom with three hollow channels (3, 2 and 1 mm in diameter) and two steel spheres (1.5 mm in diameter) is used as imaging target. Ultrasound data and OSS data are simultaneously acquired while steering and rotating a 8.5 F catheter with bidirectional tip flexion. The obtained ultrasound data are reconstructed in 3D space using the position and direction information from the OSS data. Afterwards, the sparsely sampled ultrasound data are projected on a 2D plane and interpolated using normalized convolution (NC), which has been shown previously to perform well on irregularly sampled data [1]. The front surface of the phantom together with the location of two of the three channels and the two steel spheres are successfully reconstructed. The ability to reconstruct different components and their location in space is very important during CTOs crossing. This type of information can aid the crossing procedure providing insights about the best entry point, such as channels location, and helping in avoiding highly calcified areas, which usually are displayed in ultrasound imaging as highly scattering regions.

  10. A finite element analysis of the effects of geometrical shape on the elastic properties of chemical vapor deposited diamond nanowire

    Directory of Open Access Journals (Sweden)

    Garuma Abdisa Denu

    2017-01-01

    Full Text Available We report the effect of geometrical shape of diamond nanowire on its mechanical properties. Finite element modeling using COMSOL Multiphysics software is used to simulate various diamond nanowire with circular, square, rectangular, hexagonal and triangular cross-sections. A bending test under concentrated load applied at one of the free ends is simulated using FEM. The force response of the nanowire under different loading is studied for the various cross-sections. The dimensions of each cross-section is chosen so that material properties such as Young’s modulus can be kept constant for comparison in all the cross-sections. It is found out that the bending capability of a triangular nanowire is higher compared to other cross-sections due to its lowest second moment. Circular and hexagonal cross-section show highest stiffness. The study of mechanical property of diamond nanowires is useful for optimal nanomechanical designs where the effect of cross-section has to be taken into account.

  11. When algorithms shape collective action: Social media and the dynamics of cloud protesting

    OpenAIRE

    Milan, S.

    2015-01-01

    How does the algorithmically mediated environment of social media restructure social action? This article combines social movement studies and science and technology studies to explore the role of social media in the organization, unfolding, and diffusion of contemporary protests. In particular, it examines how activists leverage the technical properties of social media to develop a joint narrative and a collective identity. To this end, it offers the notion of cloud protesting as a theoretic...

  12. When Algorithms Shape Collective Action: Social Media and the Dynamics of Cloud Protesting

    Directory of Open Access Journals (Sweden)

    Stefania Milan

    2015-12-01

    Full Text Available How does the algorithmically mediated environment of social media restructure social action? This article combines social movement studies and science and technology studies to explore the role of social media in the organization, unfolding, and diffusion of contemporary protests. In particular, it examines how activists leverage the technical properties of social media to develop a joint narrative and a collective identity. To this end, it offers the notion of cloud protesting as a theoretical approach and framework for empirical analysis. Cloud protesting indicates a specific type of mobilization that is grounded on, modeled around, and enabled by social media platforms and mobile devices and the virtual universes they identify. The notion emphasizes both the productive mediation of social and mobile media and the importance of activists’ sense-making activities. It also acknowledges that social media set in motion a process that is sociotechnical in nature rather than merely sociological or communicative, and thus can be understood only by intersecting the material and the symbolic dimensions of contemporary digitally mediated collective action. The article shows how the specific materiality of social media intervenes in the actors’ meaning work by fostering four mechanisms—namely performance, interpellation, temporality, and reproducibility—which concur to create a “politics of visibility” that alters traditional identity dynamics. In addition, it exposes the connection between organizational patterns and the role of individuals, explaining how the politics of visibility is the result of a process that originates and ends within the individual—which ultimately creates individuals-in-the-group rather than groups.

  13. Evaluation of design parameters of dental implant shape, diameter and length on stress distribution: a finite element analysis.

    Science.gov (United States)

    Mohammed Ibrahim, M; Thulasingam, C; Nasser, K S G A; Balaji, V; Rajakumar, M; Rupkumar, P

    2011-09-01

    The aim was to evaluate the design parameters of dental implants shape, diameter and length on stress distribution by finite element analysis (FEA).The objectives of the study was to compare the influence of stress distribution in the implants of screw-vent tapered and parallel design by varying the implant diameter with a standard implant length. Six dental implant models have been simulated three-dimensionally. The influence of diameter and length on stress distribution was evaluated by Group I: for screw-vent tapered design (Zimmer Dental Implant Carlsbad, CA, USA) (1) Dental implant model with diameter 3.7 mm and length 13 mm. (2) Dental implant model with diameter 4.1 mm and length 13 mm. (3) Dental implant model with diameter 4.7 mm and length 13 mm. Group II: for parallel design (Zimmer Dental Implant Carlsbad, CA, USA) (4) Dental implant model with diameter 3.7 mm and length 13 mm. (5) Dental implant model with diameter 4.1 mm and length 13 mm. (6) Dental implant model with diameter 4.7 mm and length 13 mm. The 3-D model of the implant was created in the pro-e wildfire 4.0 software by giving various commands. This model was imported to the ANSYS software through IGES (initial graphic exchange specification) file for further analysis. All six models were loaded with a force of 17.1, 114.6 and 23.4 N in a lingual, an axial and disto-mesial direction respectively, simulating average masticatory force in a natural oblique direction, to analyze the stress distribution on these implants. The increase in implant diameter in Group I and Group II from 3.7 to 4.1 mm and from 4.1 to 4.7 mm with constant 13 mm length for screw-vent tapered and parallel design implant resulted in a reduction in maximum value of Von Mises stress in the bone surrounding the implant was statistically significant at 5% level done by student "t" test. The overall maximum value of Von Mises stress was decreased in parallel design implant diameter of 4.7 mm with constant

  14. Investigation of Elemental Concentrations of Some Medicinal Herbs Collected from Kachin State

    International Nuclear Information System (INIS)

    Tint Lwin; Soe Myint; Tun Khin

    2006-06-01

    Five medicinal herbs, which are traditionally used in the Kachin State for the treatment of tuberculosis, different types of cancers, malaria and indigestion problem, were analyzed by the EDXRF techinque to determine the relative concentrations of elements contained in them. The major elements and the trace elements were thoroughly investigated for a comparison purpose

  15. NIH/NCATS/GRDR® Common Data Elements: A leading force for standardized data collection.

    Science.gov (United States)

    Rubinstein, Yaffa R; McInnes, Pamela

    2015-05-01

    The main goal of the NIH/NCATS GRDR® program is to serve as a central web-based global data repository to integrate de-identified patient clinical data from rare disease registries, and other data sources, in a standardized manner, to be available to researchers for conducting various biomedical studies, including clinical trials and to support analyses within and across diseases. The aim of the program is to advance research for many rare diseases. One of the first tasks toward achieving this goal was the development of a set of Common Data Elements (CDEs), which are controlled terminologies that represent collected data. A list of 75 CDEs was developed by a national committee and was validated and implemented during a period of 2 year proof of concept. Access to GRDR CDEs is freely available at: https://grdr.ncats.nih.gov/index.php?option=com_content&view=article&id=3&Itemid=5. The GRDR CDEs have been the cornerstone of the GRDR repository, as well as of several other national and international patient registries. The establishment of the GRDR program has elevated the issue of data standardization and interoperability for rare disease patient registries, to international attention, resulting in a global dialog and significant change in the mindset of registry developers, patient advocacy groups, and other national and international organizations. Published by Elsevier Inc.

  16. Bioconcentration factors and trace elements bioaccumulation in sporocarps of fungi collected from quartzite acidic soils.

    Science.gov (United States)

    Campos, Juan Antonio; Tejera, Noel Amaurys

    2011-10-01

    The content of 19 metals (Al, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Zr, Nb, Cs, Ba, Ce, Pb, Th, U and Nd) was investigated in 15 edible species of phylum Basidiomycota collected in an area with quartzite acidic soils in a province of the central Spain. The study explores the differences in metal accumulation in relation to fungal species, and the results were related to metal content in soil through the determination of bioconcentration factors. Regarding the highest concentrations, Zn, Al, Cu and Rb were the metals more accumulated in the sporocarps. Notable concentrations were also found in Sr, Zr, Ba, Cs and Ce. The major bioconcentration factors were found for Cu and Zn in sporocarps of Agaricus silvicola and Lepista nuda. Regarding the different species, Tricholoma equestre and Cantharellus cibarius were those with the greatest capacity to absorb trace elements, and in contrast, Amanita caesarea and Agaricus campestris showed the lowest values. The cluster analysis shows that there are some species with the same nutritive physiology that share similarities in the absorptive behaviour. Lactarius sanguifluus and Lactarius deliciosus, both ectomycorrhizas of the genus Pinus, are closely related, and Clitocybe gibba, L. nuda and Marasmius oreades, all of them saprobes on soil organic matter, are very close too.

  17. Finite element modeling of shell shape in the freshwater turtle Pseudemys concinna reveals a trade-off between mechanical strength and hydrodynamic efficiency.

    Science.gov (United States)

    Rivera, Gabriel; Stayton, C Tristan

    2011-10-01

    Aquatic species can experience different selective pressures on morphology in different flow regimes. Species inhabiting lotic regimes often adapt to these conditions by evolving low-drag (i.e., streamlined) morphologies that reduce the likelihood of dislodgment or displacement. However, hydrodynamic factors are not the only selective pressures influencing organismal morphology and shapes well suited to flow conditions may compromise performance in other roles. We investigated the possibility of morphological trade-offs in the turtle Pseudemys concinna. Individuals living in lotic environments have flatter, more streamlined shells than those living in lentic environments; however, this flatter shape may also make the shells less capable of resisting predator-induced loads. We tested the idea that "lotic" shell shapes are weaker than "lentic" shell shapes, concomitantly examining effects of sex. Geometric morphometric data were used to transform an existing finite element shell model into a series of models corresponding to the shapes of individual turtles. Models were assigned identical material properties and loaded under identical conditions, and the stresses produced by a series of eight loads were extracted to describe the strength of the shells. "Lotic" shell shapes produced significantly higher stresses than "lentic" shell shapes, indicating that the former is weaker than the latter. Females had significantly stronger shell shapes than males, although these differences were less consistent than differences between flow regimes. We conclude that, despite the potential for many-to-one mapping of shell shape onto strength, P. concinna experiences a trade-off in shell shape between hydrodynamic and mechanical performance. This trade-off may be evident in many other turtle species or any other aquatic species that also depend on a shell for defense. However, evolution of body size may provide an avenue of escape from this trade-off in some cases, as changes in

  18. How group-based emotions are shaped by collective emotions: evidence for emotional transfer and emotional burden.

    Science.gov (United States)

    Goldenberg, Amit; Saguy, Tamar; Halperin, Eran

    2014-10-01

    Extensive research has established the pivotal role that group-based emotions play in shaping intergroup processes. The underlying implicit assumption in previous work has been that these emotions reflect what the rest of the group feels (i.e., collective emotions). However, one can experience an emotion in the name of her or his group, which is inconsistent with what the collective feels. The current research investigated this phenomenon of emotional nonconformity. Particularly, we proposed that when a certain emotional reaction is perceived as appropriate, but the collective is perceived as not experiencing this emotion, people would experience stronger levels of group-based emotion, placing their emotional experience farther away from that of the collective. We provided evidence for this process across 2 different emotions: group-based guilt and group-based anger (Studies 1 and 2) and across different intergroup contexts (Israeli-Palestinian relations in Israel, and Black-White relations in the United States). In Studies 3 and 4, we demonstrate that this process is moderated by the perceived appropriateness of the collective emotional response. Studies 4 and 5 further provided evidence for the mechanisms underlying this effect, pointing to a process of emotional burden (i.e., feeling responsible for carrying the emotion in the name of the group) and of emotional transfer (i.e., transferring negative feelings one has toward the ingroup, toward the event itself). This work brings to light processes that were yet to be studied regarding the relationship between group members, their perception of their group, and the emotional processes that connect them. 2014 APA, all rights reserved

  19. A new way to parameterize hydraulic conductances of pore elements: A step towards creating pore-networks without pore shape simplifications

    Science.gov (United States)

    Miao, Xiuxiu; Gerke, Kirill M.; Sizonenko, Timofey O.

    2017-07-01

    Pore-network models were found useful in describing important flow and transport mechanisms and in predicting flow properties of different porous media relevant to numerous fundamental and industrial applications. Pore-networks provide very fast computational framework and permit simulations on large volumes of pores. This is possible due to significant pore space simplifications and linear/exponential relationships between effective properties and geometrical characteristics of the pore elements. To make such relationships work, pore-network elements are usually simplified by circular, triangular, square and other basic shapes. However, such assumptions result in inaccurate prediction of transport properties. In this paper, we propose that pore-networks can be constructed without pore shape simplifications. To test this hypothesize we extracted 3292 2D pore element cross-sections from 3D X-ray microtomography images of sandstone and carbonate rock samples. Based on the circularity, convexity and elongation of each pore element we trained neural networks to predict the dimensionless hydraulic conductance. The optimal neural network provides 90% of predictions lying within the 20% error bounds compared against direct numerical simulation results. Our novel approach opens a new way to parameterize pore-networks and we outlined future improvements to create a new class of pore-network models without pore shape simplifications.

  20. Elemental and iron isotopic composition of aerosols collected in a parking structure

    International Nuclear Information System (INIS)

    Majestic, Brian J.; Anbar, Ariel D.; Herckes, Pierre

    2009-01-01

    The trace metal contents and iron isotope composition of size-resolved aerosols were determined in a parking structure in Tempe, AZ, USA. Particulate matter (PM) 2.5 μm were collected. Several air toxics (e.g., arsenic, cadmium, and antimony) were enriched above the crustal average, implicating automobiles as an important source. Extremely high levels of fine copper (up to 1000 ng m -3 ) were also observed in the parking garage, likely from brake wear. The iron isotope composition of the aerosols were found to be + 0.15 ± 0.03 per mille and + 0.18 ± 0.03 per mille for the PM 2.5 μm fractions, respectively. The similarity of isotope composition indicates a common source for each size fraction. To better understand the source of iron in the parking garage, the elemental composition in four brake pads (two semi-metallic and two ceramic), two tire tread samples, and two waste oil samples were determined. Striking differences in the metallic and ceramic brake pads were observed. The ceramic brake pads contained 10-20% copper by mass, while the metallic brake pads contained about 70% iron, with very little copper. Both waste oil samples contained significant amounts of calcium, phosphorous, and zinc, consistent with the composition of some engine oil additives. Differences in iron isotope composition were observed between the source materials; most notably between the tire tread (average = + 0.02 per mille ) and the ceramic brake linings (average = + 0.65 per mille ). Differences in isotopic composition were also observed between the metallic (average = + 0.18 per mille ) and ceramic brake pads, implying that iron isotope composition may be used to resolve these sources. The iron isotope composition of the metallic brake pads was found to be identical to the aerosols, implying that brake dust is the dominant source of iron in a parking garage.

  1. Chemical Composition and Amounts of Mineral Elements in Honeybee-Collected Pollen in Relation to Botanical Origin

    OpenAIRE

    Taha El-Kazafy Abdou

    2015-01-01

    This study was conducted at the apiary of the Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Ahsa, Saudi Arabia. The purpose was to study the relationship between the botanical origin and chemical composition of bee-collected pollen. The amount of mineral elements present in bee-collected pollen was also studied. The composition of pollen loads showed the maximum contents of dry matter, ash, glucose, fructose, magnesium (Mg), phosphorus (P), and manganes...

  2. End-Fire Phased Array 5G Antenna Design Using Leaf-Shaped Bow-Tie Elements for 28/38 GHz MIMO Applications

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert F.

    2016-01-01

    In this paper, a new design of mm-Wave phased array 5G antenna for multiple-input multiple-output (MIMO) applications has been introduced. Two identical linear phased arrays with eight leaf-shaped bow-tie antenna elements have been used at different sides of the mobile-phone PCB. An Arlon AR 350 ...... at 28 and 38 GHz which both are powerful candidates to be the carrier frequency of the future 5G cellular networks.......In this paper, a new design of mm-Wave phased array 5G antenna for multiple-input multiple-output (MIMO) applications has been introduced. Two identical linear phased arrays with eight leaf-shaped bow-tie antenna elements have been used at different sides of the mobile-phone PCB. An Arlon AR 350...

  3. A finite element analysis of the morphology of the twinned-to-detwinned interface observed in microstructure of the Cu-Al-Ni shape memory alloy

    Czech Academy of Sciences Publication Activity Database

    Seiner, Hanuš; Glatz, O.; Landa, Michal

    2011-01-01

    Roč. 48, č. 13 (2011), s. 2005-2014 ISSN 0020-7683 R&D Projects: GA ČR(CZ) GP202/09/P164; GA MŠk(CZ) 1M06031 Institutional research plan: CEZ:AV0Z20760514 Keywords : shape- memory alloys * finite element method * microstructure * energy minimization Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.857, year: 2011 http://www.sciencedirect.com/science/article/pii/S002076831100103X

  4. Development of collection precedes targeted reaching: resting shapes of the hands and digits in 1-6-month-old human infants.

    Science.gov (United States)

    Sacrey, Lori-Ann R; Whishaw, Ian Q

    2010-12-06

    Hand shaping is an important part of many skilled hand movements and includes a number of hand shapes prominent amongst which is collection. In collection, the hand is held with the digits lightly closed and flexed. It occurs when the hand is at rest and it occurs as the hand is transported to a target in behaviors such as reaching for an object, crawling, and climbing a ladder. Collection also frequently precedes hand gestures associated with speaking. The development of collection in infancy has not been described but it might be predicted that collection should develop before grasping and reaching movements. The present study examines the development of collection and arm position during the first 6 months of infant development. Infants were filmed while awake and photographed while asleep and hand shape and the hands location relative to the torso was documented. Collection associated with a relaxed position of the arm became increasingly prominent over the first 4 weeks of life in both awake and sleeping infants. It replaces a clenched (spastic) fist that was typically held proximal to the upper torso. The results are discussed in relation to the idea that the development of collection is an important antecedent to other hand shaping movements, especially skilled movements of grasping and reaching. Copyright 2010 Elsevier B.V. All rights reserved.

  5. Elemental and iron isotopic composition of aerosols collected in a parking structure

    Energy Technology Data Exchange (ETDEWEB)

    Majestic, Brian J., E-mail: brian.majestic@asu.edu [Department of Chemistry and Biochemistry, Arizona State University, PO Box 871604, Tempe, AZ 85287-1604 (United States); Anbar, Ariel D. [Department of Chemistry and Biochemistry, Arizona State University, PO Box 871604, Tempe, AZ 85287-1604 (United States); School of Earth and Space Exploration, Arizona State University, PO Box 871604, Tempe, AZ 85287-1604 (United States); Herckes, Pierre [Department of Chemistry and Biochemistry, Arizona State University, PO Box 871604, Tempe, AZ 85287-1604 (United States)

    2009-09-01

    The trace metal contents and iron isotope composition of size-resolved aerosols were determined in a parking structure in Tempe, AZ, USA. Particulate matter (PM) < 2.5 {mu}m in diameter (the fine fraction) and PM > 2.5 {mu}m were collected. Several air toxics (e.g., arsenic, cadmium, and antimony) were enriched above the crustal average, implicating automobiles as an important source. Extremely high levels of fine copper (up to 1000 ng m{sup -3}) were also observed in the parking garage, likely from brake wear. The iron isotope composition of the aerosols were found to be + 0.15 {+-} 0.03 per mille and + 0.18 {+-} 0.03 per mille for the PM < 2.5 {mu}m and PM > 2.5 {mu}m fractions, respectively. The similarity of isotope composition indicates a common source for each size fraction. To better understand the source of iron in the parking garage, the elemental composition in four brake pads (two semi-metallic and two ceramic), two tire tread samples, and two waste oil samples were determined. Striking differences in the metallic and ceramic brake pads were observed. The ceramic brake pads contained 10-20% copper by mass, while the metallic brake pads contained about 70% iron, with very little copper. Both waste oil samples contained significant amounts of calcium, phosphorous, and zinc, consistent with the composition of some engine oil additives. Differences in iron isotope composition were observed between the source materials; most notably between the tire tread (average = + 0.02 per mille ) and the ceramic brake linings (average = + 0.65 per mille ). Differences in isotopic composition were also observed between the metallic (average = + 0.18 per mille ) and ceramic brake pads, implying that iron isotope composition may be used to resolve these sources. The iron isotope composition of the metallic brake pads was found to be identical to the aerosols, implying that brake dust is the dominant source of iron in a parking garage.

  6. The Element of Surprise: Preparing for the Possibility of Hazardous Materials within Archival Collections

    Science.gov (United States)

    Wiener, Judith A.

    2007-01-01

    Unprocessed archival collections can contain unknown and potentially hazardous materials that can be harmful to other collections and staff. Archival literature largely focuses on collection and personnel dangers posed by environmental hazards such as mold and insect infestation but not on pharmaceutical and chemical hazards. In this article, the…

  7. Finite Element Simulation of NiTi Umbrella-Shaped Implant Used on Femoral Head under Different Loadings

    Directory of Open Access Journals (Sweden)

    Reza Mehrabi

    2017-03-01

    Full Text Available In this study, an umbrella-shaped device that is used for osteonecrosis treatment is simulated. The femoral head is subjected to various complex loadings as a result of a person’s daily movements. Implant devices used in the body are made of shape memory alloy materials because of their remarkable resistance to wear and corrosion, good biocompatibility, and variable mechanical properties. Since this NiTi umbrella-shaped implant is simultaneously under several loadings, a 3-D model of shape memory alloy is utilized to investigate the behavior of the implant under different conditions. Shape memory and pseudo-elasticity behavior of NiTi is analyzed using a numerical model. The simulation is performed within different temperatures and in an isothermal condition with varied and complex loadings. The objective of this study is to evaluate the performance of the device under thermal and multi-axial forces via numerically study. Under tensile loading, the most critical points are on the top part of the implant. It is also shown that changes in temperature have a minor effect on the Von Mises stress. Applied forces and torques have significant influence on the femoral head. Simulations results indicate that the top portion of the umbrella is under the most stress when embedded in the body. Consequently, the middle, curved portion of the umbrella is under the least amount of stress.

  8. Finite element modeling of the human kidney for probabilistic occupant models: Statistical shape analysis and mesh morphing.

    Science.gov (United States)

    Yates, Keegan M; Untaroiu, Costin D

    2018-04-16

    Statistical shape analysis was conducted on 15 pairs (left and right) of human kidneys. It was shown that the left and right kidney were significantly different in size and shape. In addition, several common modes of kidney variation were identified using statistical shape analysis. Semi-automatic mesh morphing techniques have been developed to efficiently create subject specific meshes from a template mesh with a similar geometry. Subject specific meshes as well as probabilistic kidney meshes were created from a template mesh. Mesh quality remained about the same as the template mesh while only taking a fraction of the time to create the mesh from scratch or morph with manually identified landmarks. This technique can help enhance the quality of information gathered from experimental testing with subject specific meshes as well as help to more efficiently predict injury by creating models with the mean shape as well as models at the extremes for each principal component. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. U-Shaped Fiber-Optic Detection Elements for Investigation of Photocatalytic Decomposition of Toluene Dissolved in Water

    Czech Academy of Sciences Publication Activity Database

    Matějec, Vlastimil; Bartoň, Ivo; Mrázek, Jan; Podrazký, Ondřej

    2014-01-01

    Roč. 27, May (2014), s. 244-252 ISSN 2306-8515 R&D Projects: GA ČR GAP102/12/2361 Institutional support: RVO:67985882 Keywords : Toluene detection * Photocatalytic decomposition * U-Shaped fiber Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  10. Variations in Element Levels Accumulated in Different Parts of Boletus edulis Collected from Central Yunnan Province, China

    Directory of Open Access Journals (Sweden)

    Xue-Mei Wang

    2015-01-01

    Full Text Available ICP-AES and microwave assisted digestion were applied to determine P, Mg, Ca, Zn, Na, Cu, Ba, Ni, V, Cd, Sr, Co, and Li in the caps and stipes of Boletus edulis collected from six spatially distant sites in Yunnan province, China. Fruiting bodies of King Bolete are abundant in P, Mg, Ca, Zn, Cu, and Na, followed by Ba, Cd, Ni, V, Li, Sr, and Co. Contents of P, Mg, Zn, and Cu are more abundant in caps than in stipes of King Bolete. However, elements such as Na, Ba, Cd, Ni, V, Li, Sr, and Co prefer to accumulate in stipes of mushrooms from Yaoan, Chuxiong. The results of this study indicate that spatial variations of elements between caps and stipes are mainly related to different bedrock soil geochemistry and enrichment capability for various elements.

  11. Mechanical behaviour of umbrella-shaped, Ni-Ti memory alloy femoral head support device during implant operation: a finite element analysis study.

    Directory of Open Access Journals (Sweden)

    Wei Yi

    Full Text Available A new instrument used for treating femoral head osteonecrosis was recently proposed: the umbrella-shaped, Ni-Ti memory femoral head support device. The device has an efficacy rate of 82.35%. Traditional radiographic study provides limited information about the mechanical behaviour of the support device during an implant operation. Thus, this study proposes a finite element analysis method, which includes a 3-step formal head model construction scheme and a unique material assignment strategy for evaluating mechanical behaviour during an implant operation. Four different scenarios with different constraints, initial positions and bone qualities are analyzed using the simulation method. The max radium of the implanted device was consistent with observation data, which confirms the accuracy of the proposed method. To ensure that the device does not unexpectedly open and puncture the femoral head, the constraint on the impact device should be strong. The initial position of sleeve should be in the middle to reduce the damage to the decompression channel. The operation may fail because of poor bone quality caused by severe osteoporosis. The proposed finite element analysis method has proven to be an accurate tool for studying the mechanical behaviour of umbrella-shaped, Ni-Ti memory alloy femoral head support device during an implant operation. The 3-step construct scheme can be implemented with any kind of bone structure meshed with multiple element types.

  12. Finite element analysis in defining the optimal shape and safety factor of retentive clasp arms of removable partial denture

    Directory of Open Access Journals (Sweden)

    Šćepanović Miodrag

    2013-01-01

    Full Text Available Bacground/Aim. Retentive force of removable partial denture (RPD directly depends on elastic force of stretched retentive clasp arms (RCAs. During deflection RCA must have even stress distribution. Safety factor is the concept which can be applied in estimating durability and functionality of RCAs. This study was based on analyzing properties of clasps designed by conventional clasp wax profiles and defining the optimal shapes of RCAs for stress distribution and safety factor aspects. Methods. Computer-aided-design (CAD models of RCAs with simulated properties of materials used for fabrication of RPD cobalt-chromium-molybdenum (CoCrMo alloy, commercially pure titanium (CPTi and polyacetale were analyzed. Results. The research showed that geometrics of Rapidflex profiles from the BIOS concept are defined for designing and modeling RCAs from CoCrMo alloys. I-Bar and Bonihard clasps made from CPTi might have the same design as Co- CrMo clasp only by safety factor aspect, but it is obvious that CPTi are much more flexible, so their shape must be more massive. Polyacetale clasps should not be fabricated by BIOS concept for CoCrMo alloy. A proof for that is the low value of safety factor. Conclusion. The BIOS concept should be used only for RCAs made of CoCrMo alloy and different wax profiles should be used for fabricating clasps of other investigated materials. The contribution of this study may be the improvement of present systems for defining the clasps shapes made from CoCrMo alloys. The more significant application is possibility of creating new concepts in defining shapes of RCA made from CPTi and polyacetale.

  13. Microtubules as key cytoskeletal elements in cellular transport and shape changes: their expected responses to space environments

    Science.gov (United States)

    Conrad, G. W.; Conrad, A. H.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    Application of reference standard reagents to alternatively depolymerize or stabilize microtubules in a cell that undergoes very regular cytoskeleton-dependent shape changes provides a model system in which some expected components of the environments of spacecraft and space can be tested on Earth for their effects on the cytoskeleton. The fertilized eggs of Ilyanassa obsoleta undergo polar lobe formation by repeated, dramatic, constriction and relaxation of a microfilamentous band localized in the cortical cytoplasm and activated by microtubules.

  14. Finite element analysis of optimized H shape spring in a nuclear fuel spacer grid by using contact definition

    International Nuclear Information System (INIS)

    Kim, Jae-Yong; Yoon, Kyung-Ho

    2007-01-01

    The primary role of the grid springs in spacer grid is to hold the fuel rods in an appropriate position using friction force and to prevent the fuel rods dropping during reactor operation. The spring force decreases as the fuel burn-up increases since the spring stiffness is degraded due to the high temperature and the irradiation effect in the reactor core. So this phenomenon has to be considered when the initial spring force of grid spring is designed. To check whether the spring have suitable spring force, the characterization test of spring is conducted. In this paper, finite element analysis using contact definition is established for prediction the spring stiffness without test. The test and analysis results are compared to check the availability of finite element model for investing the spring characteristics in assembly condition. (author)

  15. Coupled thermomechanical finite element analysis to improve press formability for camera shape using AZ31B magnesium alloy sheet

    Science.gov (United States)

    Duc-Toan, Nguyen; Young-Suk, Kim; Dong-Won, Jung

    2012-08-01

    In this study, a finite element analysis aimed at predicting and improving the press formability for a camera casing made of AZ31B magnesium alloy sheet was conducted. First, stress-strain curves and forming limit curves (FLDs) for warm temperatures were obtained. The data from these curves and the ductile fracture criterion of FLDs were then input into ABAQUS/Explicit finite element code to predict the failure occurrence of the camera casing. In the finite element method (FEM) simulation, for investigating the effect of reduced temperature during the punch cooling process on the formability of the camera casing, coupled thermomechanical computational modeling was considered and verified by comparison with experimental results. Based on the good agreement between the simulation and the experimental results, three parameters-blank holding force, elevated temperature, and friction coefficient-were selected to improve the press formability of the camera casing in the coupling of the FEM simulations and Taguchi's orthogonal array experiment. The optimum simulation case was confirmed through an experiment.

  16. Microparticles and human health: particulate materials, trace metals elements and black carbon in aerosols collected at Andravoahangy-Antananarivo, Madagascar

    International Nuclear Information System (INIS)

    Rasoazanany, E. O.; Andriamahenina, N. N.; Harinoely, M.; Ravoson, H. N.; Randriamanivo, L. V.; Raoelina Andriambololona; Ramaherison, H.

    2013-01-01

    The present work is to determine the concentrations of microparticles having diameter inferior to 10 μm (PM 10 ), the metal trace elements and the black carbon in the aerosols sampled in Andravoahangy-Antananarivo, Madagascar in 2008. The air sampler GENT is used to collect aerosol samples. The total reflection X-ray fluorescence spectrometer is used for qualitative and quantitative analysis of simultaneous way all metallic trace elements contained in the aerosols. The M43D reflectometer permits to measure the reflectances in order to determine the black carbon concentrations. The results show that the average concentrations of the particulate matters PM 2,5-10 are higher than those of PM 2,5 . The average concentrations of PM 10 in the aerosols are exceeding the World Health Organisation (WHO) and European Union guidelines, set at 50 μg.m -3 and those of PM 2,5 are higher than the 2005 WHO (25 μg.m-3) and the United States Environment Protection Agency (35 μg.m -3 ) guidelines. Consequently, air quality in Andravoahangy does not respect these daily guidelines. The identified metallic trace elements in the aerosols are Ti, Cr, Mn, Fe, Ni, Cu, Zn and Pb. The average concentrations of these elements are also higher in the coarse particles than in the fine particles. The concentrations of black carbon are higher in the fine particles. The maximum value is 9.12 μg.m -3 . [fr

  17. Determination of multi-element in marine sediment samples collected in Angola by the k0-NAA technique

    International Nuclear Information System (INIS)

    Teixeira, M.C.P.; Ho Manh Dung; Cao Dong Vu; Nguyen Thi Sy; Nguyen Thanh Binh; Vuong Huu Tan

    2006-01-01

    The marine sediment samples were designed to collect in Angola for marine environmental pollution study. The k 0 -standardization method of neutron activation analysis (k 0 -NAA) on Dalat research reactor has been developed to determine of multi-element in the Angola marine sediment samples. The samples were irradiated in cell 7-1 for short- and middle-lived nuclides and rotary specimen rack for long-lived nuclides. The irradiation facilities were characterized for neutron spectrum parameters and post-activated samples were measured on the calibrated gamma-ray spectrometers using HPGe detectors. The analytical results for 9 marine sediment samples with 27 elements: Al, As, Br, Ca, Ce,Cl, Co, Cs, Dy, Fe, Hf, I, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Sm, Th, Ti, U, V and Zn in term of mean concentration, standard deviation and their content range are shown in the report. The analytical quality assurance was done by analysis of a Japan's certified reference material namely marine sediment NMIJ-CRM-7302a. These preliminary results revealed that the k 0 -NAA technique on the Dalat research reactor is a good analytical technique for determination of multi-element in the marine sediment samples. Some heavy metals and trace elements determined in this work possibly connected to the human activities at the sampling region. (author)

  18. The Instability Improvement of the Symmetric Angle-Ply and Cross-Ply Composite Plates with Shape Memory Alloy Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Zainudin A. Rasid

    2014-02-01

    Full Text Available Shape memory alloy (SMA wires were embedded within laminated composite plates to take advantage of the shape memory effect property of the SMA in improving post-buckling behavior of composite plates. A nonlinear finite element formulation was developed for this study. The plate-bending formulation used in this study was developed based on the first order shear deformation theory, where the von Karman's nonlinear moderate strain terms were added to the strain equations. The effect of the SMA was captured by adding recovery stress term in the constitutive equation of the SMA composite plates. Values of the recovery stress of the SMA were determined using Brinson's model. Using the principle of virtual work and the total Lagrangian approach, the final finite element nonlinear governing equation for the post-buckling of SMA composite plates was derived. Buckling and post-buckling analyses were then conducted on the symmetric angle-ply and cross-ply SMA composite plates. The effect of several parameters such as the activation temperature, volume fraction, and the initial strain of the SMA on the post-buckling behavior of the SMA composite plates were studied. It was found that significant improvements in the post-buckling behavior for composite plates can be attained.

  19. An approach to measure trace elements in particles collected on fiber filters using EDXRF.

    Science.gov (United States)

    Oztürk, Fatma; Zararsiz, Abdullah; Kirmaz, Ridvan; Tuncel, Gürdal

    2011-01-15

    A method developed for analyzes of large number of aerosol samples using Energy Dispersive X-Ray Fluorescence (EDXRF) and its performance were discussed in this manuscript. Atmospheric aerosol samples evaluated in this study were collected on cellulose fiber (Whatman-41) filters, employing a Hi-Vol sampler, at a monitoring station located on the Mediterranean coast of Turkey, between 1993 and 2001. Approximately 1700 samples were collected in this period. Six-hundred of these samples were analyzed by instrumental neutron activation (INAA), and the rest were archived. EDXRF was selected as an analytical technique to analyze 1700 aerosol samples because of its speed and non-destructive nature. However, analysis of aerosol samples collected on fiber filters with a surface technique such as EDXRF was a challenge. Penetration depth calculation performed in this study revealed that EDXRF can obtain information from top 150μm of our fiber filter material. Calibration of the instrument with currently available thin film standards caused unsatisfactory results since the actual penetration depth of particles into fiber filters were much deeper than 150μm. A method was developed in this manuscript to analyze fiber filter samples quickly with XRF. Two hundred samples that were analyzed by INAA were divided into two equal batches. One of these batches was used to calibrate the XRF and the second batch was used for verification. The results showed that developed method can be reliably used for routine analysis of fiber samples loaded with ambient aerosol. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Beyond data collection in digital mapping: interpretation, sketching and thought process elements in geological map making

    Science.gov (United States)

    Watkins, Hannah; Bond, Clare; Butler, Rob

    2016-04-01

    Geological mapping techniques have advanced significantly in recent years from paper fieldslips to Toughbook, smartphone and tablet mapping; but how do the methods used to create a geological map affect the thought processes that result in the final map interpretation? Geological maps have many key roles in the field of geosciences including understanding geological processes and geometries in 3D, interpreting geological histories and understanding stratigraphic relationships in 2D and 3D. Here we consider the impact of the methods used to create a map on the thought processes that result in the final geological map interpretation. As mapping technology has advanced in recent years, the way in which we produce geological maps has also changed. Traditional geological mapping is undertaken using paper fieldslips, pencils and compass clinometers. The map interpretation evolves through time as data is collected. This interpretive process that results in the final geological map is often supported by recording in a field notebook, observations, ideas and alternative geological models explored with the use of sketches and evolutionary diagrams. In combination the field map and notebook can be used to challenge the map interpretation and consider its uncertainties. These uncertainties and the balance of data to interpretation are often lost in the creation of published 'fair' copy geological maps. The advent of Toughbooks, smartphones and tablets in the production of geological maps has changed the process of map creation. Digital data collection, particularly through the use of inbuilt gyrometers in phones and tablets, has changed smartphones into geological mapping tools that can be used to collect lots of geological data quickly. With GPS functionality this data is also geospatially located, assuming good GPS connectivity, and can be linked to georeferenced infield photography. In contrast line drawing, for example for lithological boundary interpretation and sketching

  1. Identifying shared and contested elements in climate plans as part of shaping transitions towards a Danish low carbon society

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard

    2011-01-01

    The Danish government's vision about Denmark as a society independent of fossil energy has initiated several Danish energy and climate action plans during 2009-2010 with visions and measures for a 30-40 year time perspective. The paper analyses differences and similarities in action plans from...... the Danish Society of Engineers, a renewable energy NGO, an environmental NGO and a national climate change commission. The aim is to identify shared and contested elements, which need to be addressed in attempts to establish alignment around transition efforts towards a fossil free Danish society....... The analyses are conducted as part of a project about sustainable transitions towards a low carbon society. The plan from the renewable energy NGO is an energy plan, while the other plans are climate plans, which include non-energy related greenhouse gasses from land use changes and use of fertilizers...

  2. The image of a research institution as an important element in shaping the level of competitiveness of the organisation

    Directory of Open Access Journals (Sweden)

    Świeczak Witold

    2017-06-01

    Full Text Available The primary objective of the publication is defining the factors and processes affecting the efficient course of actions undertaken around building a positive image of the organisation. The study raises key aspects of this issue. The diagnosis providing that the recipient is guided in his/her purchasing decisions by the opinions about a given product or service that reach them through all the available content distribution channels is appearing increasingly often in subsequent study findings. The same studies have also confirmed that an inherent feature of a knowledge-based economy is the level of the intangible asset share as regards determining the position of an organisation (brand, reputation. The unbridled increase in competition has led to the generation of a growing volume of advertising offers for buyers, as a result of which standing out among other market players has now become more of an issue. One of the ways to enhance an organisation’s presence in a changing environment includes measures promoting its positive image creation and shaping of favourable (valuable opinions about it. The selection of the appropriate image concept to a constantly changing business environment in terms of competing or consumer preferences requires an effective response to their experiences in the cognitive, emotional and behavioural dimensions. If they are positive, they will contribute to building a favourable mindset among consumers, which in turn will facilitate the formation of a positive image of the organisation.

  3. A subspace thermodynamic model for shape memory alloy wire elements undergoing combined thermo-mechanical axial and torsional loads

    Science.gov (United States)

    Sumanth, D.; Preetish, K. L.; Srinivasan, S. M.

    2014-08-01

    Given that most applications of shape memory alloys (SMA) are in the wire form, a reduced order model and analysis has been attempted in this paper. It takes into account the fact that the predominant actions are axial (bending inclusive) and torsional. A thermodynamic framework is first developed to simulate the behaviour of the SMA material under thermo-mechanical loading that is a combination of axial and shear stresses arising at a point in a wire due to axial and torsional loads applied to the wire. Since only a few variants relevant to axial-torsion are going to be active in transformation under this kind of loading, a reduced order model that tracks the evolution of four martensite variants and an austenite variant is proposed. It is shown through simulations that these five model parameters amply form a minimal set of model parameters sufficient for simulating response under tension-torsion loading excursions. The model is further applied to the structural member, in this case, a wire of circular cross-section subject to a twist and an axial extension and the capability of the model to simulate the kind of response expected in wires. Incorporation of this model into a large deformation space frame nonlinear analysis will help in the design and analysis of several applications where SMA wire forms are used.

  4. A subspace thermodynamic model for shape memory alloy wire elements undergoing combined thermo-mechanical axial and torsional loads

    International Nuclear Information System (INIS)

    Sumanth, D; Preetish, K L; Srinivasan, S M

    2014-01-01

    Given that most applications of shape memory alloys (SMA) are in the wire form, a reduced order model and analysis has been attempted in this paper. It takes into account the fact that the predominant actions are axial (bending inclusive) and torsional. A thermodynamic framework is first developed to simulate the behaviour of the SMA material under thermo-mechanical loading that is a combination of axial and shear stresses arising at a point in a wire due to axial and torsional loads applied to the wire. Since only a few variants relevant to axial-torsion are going to be active in transformation under this kind of loading, a reduced order model that tracks the evolution of four martensite variants and an austenite variant is proposed. It is shown through simulations that these five model parameters amply form a minimal set of model parameters sufficient for simulating response under tension–torsion loading excursions. The model is further applied to the structural member, in this case, a wire of circular cross-section subject to a twist and an axial extension and the capability of the model to simulate the kind of response expected in wires. Incorporation of this model into a large deformation space frame nonlinear analysis will help in the design and analysis of several applications where SMA wire forms are used. (paper)

  5. An X-ray fluorescence method for the determination of small quantities el elements collected on filters

    International Nuclear Information System (INIS)

    Diaz-Guerra, J.P.; Bayon, A.

    1981-01-01

    An X-ray fluorescence method for the determination of As, Ba, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, U, V and Zn collected on P.V.C. filters in concentration ranges from 0,6 to 1000μg, depending on the element, is described. A sequential automatic spectrometer with a chromium tube is used for tho Ba determination, while As, Hg, Pb, Se and U are bottler determined with a molybdenum one. For the rest of the elements a tungsten target is preferred. The interferences between AsK α 1 ,2- PbL α 1 ,2 and CrK α 1 ,2-Vkβ 1 ,3 lines are corrected by applying specific coefficients. The radial variation of the primary X-ray beam intensity on the irradiated surface has been specially studied with chromium, gold, molybdenum and tungsten tubes. For that purpose different x-ray wavelengths in the range 9,89 A to 0,56 A have been selected. The curves obtained show a rather high heterogeneity for the excitation source. This conclusion implies the need for an homogeneous distribution of elements on the filter. (Author) 7 refs

  6. The effect of addition of various elements on properties of NiTi-based shape memory alloys for biomedical application

    Science.gov (United States)

    Kök, Mediha; Ateş, Gonca

    2017-04-01

    In biomedical applications, NiTi and NiTi-based alloys that show their shape memory effects at body temperature are preferred. In this study, the purpose is to produce NiTi and NiTi-based alloys with various chemical rates and electron concentrations and to examine their various physical properties. N45Ti55, Ni45Ti50Cr2.5Cu2.5, Ni48Ti51X (X=Mn, Sn, Co) alloys were produced in an arc melter furnace in this study. After the homogenization of these alloys, the martensitic phase transformation temperatures were determined with differential-scanner calorimeter. The transformation temperature was found to be below the 37 ° C (body temperature) in Ni45Ti50Cr2.5Cu2.5, Ni48Ti51X (X=Mn, Co) alloys; and the transformation temperature of the N45Ti55, Ni48Ti51Sn alloys was found to be over 37 ° C . Then, the micro and crystal structure analyses of the alloys were made, and it was determined that Ni45Ti50Cr2.5Cu2.5, Ni48Ti51X (X=Mn, Co) alloys, which were in austenite phase at room temperature, included B2 (NiTi) phase and Ti2Ni precipitation phase, and the alloys that were in the martensite phase at room temperature included B19ı (NiTi) phase and Ti2Ni phase. The common phase in both alloy groups is the Ti2Ni phase, and this type of phase is generally seen in NiTi alloys that are rich in titanium (Ti-rich).

  7. [A radiological case collection with interactive character as a new element in the education of medical students].

    Science.gov (United States)

    Heye, T; Kurz, P; Eiers, M; Kauffmann, G W; Schipp, A

    2008-04-01

    Evaluation of an interactive, multimedia case-based learning platform for the radiological education of medical students. An interactive electronic learning platform for the education of medical students was built in HTML format independent of the operating system in the context of the Heidelberg Curriculum Medicinale (HeiCuMed). A case collection of 30 common and authentic clinical cases is used as the central theme and clinical background. The user has to work on each case by making decisions regarding a selection of diagnostic modalities and by analyzing the chosen studies. After a reasonable selection and sequence of diagnostic radiological modalities and their interpretation, a diagnosis has to be made. An extensive collection of normal findings for any modality is available for the user as a reference in correlation with the pathology at anytime within each case. The case collection consists of 2053 files with 1109 Internet pages (HTML) and 869 image files (.jpeg) with approximately 10 000 crosslinks (links). The case collection was evaluated by a questionnaire (scale 1 - 5) at the end of the radiological student course. The development of the results of the radiological course exam was analyzed to investigate any effect on the learning performance after the case collection was introduced. 97.6 % of the course participants would use the case collection beyond the radiological student course to learn radiology in their medical studies. The handling of the case collection was rated excellent in 36.9 %, good in 54.6 %, satisfactory in 8 % and unsatisfactory in 0.4 %. 41 % felt that the case collection was overall excellent, 49.2 % good, 7.8 % satisfactory, 1.6 % unsatisfactory and 0.4 % poor. A positive trend in the development of the results in the radiological course exam with less variance after the introduction of the case collection was found but failed statistical significance. A platform-independent, interactive, multimedia learning platform with

  8. Toxicologically important trace elements and organic compounds investigated in size-fractionated urban particulate matter collected near the Prague highway

    International Nuclear Information System (INIS)

    Sysalová, Jiřina; Sýkorová, Ivana; Havelcová, Martina; Száková, Jiřina; Trejtnarová, Hana; Kotlík, Bohumil

    2012-01-01

    Urban particulate matter was collected in the most exposed area of Prague, near a busy highway, in order to provide petrographic and chemical characterization useful for health impact assessment in that locality or other applications. Samples were collected from filters of the air conditioning system in two years, 2009 and 2010, and sieved into four grain-size fractions: 0.507–0.119 mm, 0.119–0.063 mm, 3 extracted solutions. A composition of inorganic and carbonaceous particles of natural and anthropogenic origin and their morphology were studied by optical and electron microscopy. Organic solvent extracts of the samples were analyzed using gas chromatography to compare the organic compound distribution in fractions. Only slight differences between 2009 and 2010 years are visible. The relatively high extractable part of most investigated elements confirms mobility and potential availability to organisms. The changes can be recognized in the petrographic and organic composition in samples from both years, which were likely the result of various inputs of source materials. Specific organic marker compounds indicate contribution from fossil fuels, plant materials and bacteria. -- Highlights: ► Uncommon urban particulate matter collected near the highway in years 2009 and 2010 was deeply characterized. ► Harmful organic compounds and toxic analytes were tested in grain-size fractions and completed with electron microscopy studies. ► Very similar concentration levels were found in elemental composition in samples from two years. ► Petrographic and organic compositions were different in both samples. ► Relatively high mobility of selected analytes was found in 2M HNO 3 extracted solutions.

  9. Chemical Composition and Amounts of Mineral Elements in Honeybee-Collected Pollen in Relation to Botanical Origin

    Directory of Open Access Journals (Sweden)

    Taha El-Kazafy Abdou

    2015-06-01

    Full Text Available This study was conducted at the apiary of the Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Ahsa, Saudi Arabia. The purpose was to study the relationship between the botanical origin and chemical composition of bee-collected pollen. The amount of mineral elements present in bee-collected pollen was also studied. The composition of pollen loads showed the maximum contents of dry matter, ash, glucose, fructose, magnesium (Mg, phosphorus (P, and manganese (Mn for the date palm; the maximum contents of protein, calcium (Ca, and zinc (Zn for alfalfa; the maximum contents of fiber, and copper (Cu for the sunflower; the maximum contents of the lipids and iron (Fe for summer squash; and the maximum contents of sodium (Na, and potassium (K for rape. Calcium was found to be correlated in a significantly (p<0.01 positive way with K, Na, Mg, P, Mn, and Zn. Copper, though, was correlated in a significantly (p<0.01 negative way with Ca, Mg, P, Mn, and Zn. The high levels of protein, ash, glucose, and fructose, and low lipid content found in bee-pollen from the date palm and from alfalfa, mean that pollen from the date palm and from alfalfa make an excellent food supplement. It was concluded, that the chemical composition of beecollected pollen can be correlated with the plant species from which pollen was collected.

  10. Comparison of forces generated during root canal shaping and residual stresses of three nickel-titanium rotary files by using a three-dimensional finite-element analysis.

    Science.gov (United States)

    Kim, Hyeon-Cheol; Cheung, Gary Shun-Pan; Lee, Chan-Joo; Kim, Byung-Min; Park, Jeong-Kil; Kang, Soon-Il

    2008-06-01

    The study was aimed to compare the stress distribution during simulated root canal shaping and to estimate the residual stress thereafter for some nickel-titanium rotary instruments. Three brands of instruments (ProFile, ProTaper, and ProTaper Universal; Dentsply Maillefer) were scanned with micro-computed tomography to produce a real-size, 3-dimensional model for each. The stresses on the instrument during simulated shaping of a root canal were analyzed numerically by using a 3-dimensional finite-element package, taking into account the nonlinear mechanical behavior of the nickel-titanium material. From the simulation, the original ProTaper design showed the greatest pull in the apical direction and the highest reaction torque from the root canal wall, whereas ProFile showed the least. In ProTaper, stresses were concentrated at the cutting edge, and the residual stress reached a level close to the critical stress for phase transformation of the material. The residual stress was highest in ProTaper followed by ProTaper Universal and ProFile.

  11. Influence of slip system combination models on crystal plasticity finite element simulation of NiTi shape memory alloy undergoing uniaxial compression

    Directory of Open Access Journals (Sweden)

    Li Hu

    2017-10-01

    Full Text Available The influence of various slip system combination models on crystal plasticity finite element simulation of NiTi shape memory alloy subjected to uniaxial compression deformation is investigated according to three combinations of slip systems, including combination of {010}〈100〉 and {110}〈111〉 slip modes, combination of {110}〈100〉 and {110}〈111〉 slip modes and combination of {110}〈100〉, {010}〈100〉 and {110}〈111〉 slip modes, which consist of 18, 18 and 24 slip systems, respectively. By means of simulating mechanical response, strain distribution, stress distribution and Schmid factor, it can be found that in terms of simulation accuracy, combination of {110}〈100〉 and {110}〈111〉 slip modes is in good agreement with combination of {110}〈100〉, {010}〈100〉 and {110}〈111〉 slip modes. The contribution of {110}〈100〉 slip mode to plastic strain is primary in plastic deformation of NiTi shape memory alloy, whereas {010}〈100〉 slip mode, which makes small contribution to plastic deformation, can be regarded as the unfavorable slip mode. In the case of large plastic strain, the {010}〈100〉 slip mode contributes to the formation of (001 [01¯0] texture component, while {110}〈100〉 and {110}〈111〉 slip modes facilitate the formation of γ-fibre (〈111〉 texture. Keywords: Shape memory alloy, Plastic deformation, Crystal plasticity, Finite element method, Texture

  12. Levels of trace elements in green turtle eggs collected from Hong Kong: Evidence of risks due to selenium and nickel

    International Nuclear Information System (INIS)

    Lam, James C.W.; Tanabe, Shinsuke; Chan, Simon K.F.; Lam, Michael H.W.; Martin, Michael; Lam, Paul K.S.

    2006-01-01

    Concentrations of 22 trace elements were determined in green turtle (Chelonia mydas) eggs collected from Hong Kong. Concentrations of selenium, lead and nickel in these eggs were generally higher than those reported in other studies. The predicted no effect concentrations (PNEC; ng/g wet weight) of Pb (1000), Se (340 and 6000 for the worst-case and best-case scenarios, respectively) and Ni (17) in the green turtle eggs were estimated. Hazard quotients (HQs) estimate that Se (HQs: 0.2-24.5) and Ni (HQs: 4.0-26.4) may pose some risks to the turtles. Our study also found that concentrations of Ag, Se, Zn, Hg and Pb in the shell of the turtle eggs were significantly correlated with levels in the whole egg contents (yolk + albumen). Once the precise relationships of specific elements are established, egg-shell concentrations may be used as a non-lethal, non-invasive, surrogate for predicting whole egg burden of certain contaminants in marine turtles. - Concentrations of selenium and nickel in green turtle eggs from Hong Kong might pose some risks to the turtles

  13. Levels of trace elements in green turtle eggs collected from Hong Kong: Evidence of risks due to selenium and nickel

    Energy Technology Data Exchange (ETDEWEB)

    Lam, James C.W. [Center for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China); Tanabe, Shinsuke [Center for Marine Environmental Studies, Ehime University, Tarumi 3-5-7, Matsuyama 790-8556 (Japan); Chan, Simon K.F. [Agriculture, Fisheries and Conservation Department, Hong Kong SAR Government, Hong Kong, (China); Lam, Michael H.W. [Center for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China); Martin, Michael [Center for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China); Lam, Paul K.S. [Center for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China)]. E-mail: bhpksl@cityu.edu.hk

    2006-12-15

    Concentrations of 22 trace elements were determined in green turtle (Chelonia mydas) eggs collected from Hong Kong. Concentrations of selenium, lead and nickel in these eggs were generally higher than those reported in other studies. The predicted no effect concentrations (PNEC; ng/g wet weight) of Pb (1000), Se (340 and 6000 for the worst-case and best-case scenarios, respectively) and Ni (17) in the green turtle eggs were estimated. Hazard quotients (HQs) estimate that Se (HQs: 0.2-24.5) and Ni (HQs: 4.0-26.4) may pose some risks to the turtles. Our study also found that concentrations of Ag, Se, Zn, Hg and Pb in the shell of the turtle eggs were significantly correlated with levels in the whole egg contents (yolk + albumen). Once the precise relationships of specific elements are established, egg-shell concentrations may be used as a non-lethal, non-invasive, surrogate for predicting whole egg burden of certain contaminants in marine turtles. - Concentrations of selenium and nickel in green turtle eggs from Hong Kong might pose some risks to the turtles.

  14. Migration in the Anthropocene: how collective navigation, environmental system and taxonomy shape the vulnerability of migratory species.

    Science.gov (United States)

    Hardesty-Moore, Molly; Deinet, Stefanie; Freeman, Robin; Titcomb, Georgia C; Dillon, Erin M; Stears, Keenan; Klope, Maggie; Bui, An; Orr, Devyn; Young, Hillary S; Miller-Ter Kuile, Ana; Hughey, Lacey F; McCauley, Douglas J

    2018-05-19

    Recent increases in human disturbance pose significant threats to migratory species using collective movement strategies. Key threats to migrants may differ depending on behavioural traits (e.g. collective navigation), taxonomy and the environmental system (i.e. freshwater, marine or terrestrial) associated with migration. We quantitatively assess how collective navigation, taxonomic membership and environmental system impact species' vulnerability by (i) evaluating population change in migratory and non-migratory bird, mammal and fish species using the Living Planet Database (LPD), (ii) analysing the role of collective navigation and environmental system on migrant extinction risk using International Union for Conservation of Nature (IUCN) classifications and (iii) compiling literature on geographical range change of migratory species. Likelihood of population decrease differed by taxonomic group: migratory birds were more likely to experience annual declines than non-migrants, while mammals displayed the opposite pattern. Within migratory species in IUCN, we observed that collective navigation and environmental system were important predictors of extinction risk for fishes and birds, but not for mammals, which had overall higher extinction risk than other taxa. We found high phylogenetic relatedness among collectively navigating species, which could have obscured its importance in determining extinction risk. Overall, outputs from these analyses can help guide strategic interventions to conserve the most vulnerable migrations.This article is part of the theme issue 'Collective movement ecology'. © 2018 The Author(s).

  15. Laser Direct Writing of Tree-Shaped Hierarchical Cones on a Superhydrophobic Film for High-Efficiency Water Collection.

    Science.gov (United States)

    Wang, Meng; Liu, Qian; Zhang, Haoran; Wang, Chuang; Wang, Lei; Xiang, Bingxi; Fan, Yongtao; Guo, Chuan Fei; Ruan, Shuangchen

    2017-08-30

    Directional water collection has stimulated a great deal of interest because of its potential applications in the field of microfluidics, liquid transportation, fog harvesting, and so forth. There have been some bio or bioinspired structures for directional water collection, from one-dimensional spider silk to two-dimensional star-like patterns to three-dimensional Nepenthes alata. Here we present a simple way for the accurate design and highly controllable driving of tiny droplets: by laser direct writing of hierarchical patterns with modified wettability and desired geometry on a superhydrophobic film, the patterned film can precisely and directionally drive tiny water droplets and dramatically improve the efficiency of water collection with a factor of ∼36 compared with the original superhydrophobic film. Such a patterned film might be an ideal platform for water collection from humid air and for planar microfluidics without tunnels.

  16. [How does collective violence shape the health status of its victims? Conceptual model and design of the ISAVIC study].

    Science.gov (United States)

    Larizgoitia, Itziar; Izarzugaza, Isabel; Markez, Iñaki; Fernández, Itziar; Iraurgi, Ioseba; Larizgoitia, Arantza; Ballesteros, Javier; Fernández-Liria, Alberto; Moreno, Florentino; Retolaza, Ander; Páez, Darío; Martín-Beristaín, Carlos; Alonso, Jordi

    2011-01-01

    Epidemiologic research on collective violence (violence exerted by and within groups in pursuit of political, social or economic goals) is very scarce despite its growing recognition as a major public health issue. This paper describes the conceptual model and design of one of the first research studies conducted in Spain aiming to assess the impact of collective violence in the health status of its victims (study known as ISAVIC, based on its Spanish title Impacto en la SAlud de la VIolencia Colectiva). Starting with a comprehensive but non-systematic review of the literature, the authors describe the sequelae likely produced by collective violence and propose a conceptual model to explain the nature of the relationships between collective violence and health status. The conceptual model informed the ISAVIC study design and its measurement instruments. The possible sequelae of collective violence, in the physical, emotional and social dimensions of health, are described. Also, the review distinguishes the likely impact in primary and secondary victims, as well as the interplay with the social environment. The mixed methodological design of the ISAVIC study supports the coherence of the conceptual model described. The ISAVIC study suggests that collective violence may affect the main dimensions of the health status of its victims, in intimate relation to the societal factors where it operates. It is necessary to validate these results with new studies. Copyright © 2010 SESPAS. Published by Elsevier Espana. All rights reserved.

  17. Toxicologically important trace elements and organic compounds investigated in size-fractionated urban particulate matter collected near the Prague highway.

    Science.gov (United States)

    Sysalová, Jiřina; Sýkorová, Ivana; Havelcová, Martina; Száková, Jiřina; Trejtnarová, Hana; Kotlík, Bohumil

    2012-10-15

    Urban particulate matter was collected in the most exposed area of Prague, near a busy highway, in order to provide petrographic and chemical characterization useful for health impact assessment in that locality or other applications. Samples were collected from filters of the air conditioning system in two years, 2009 and 2010, and sieved into four grain-size fractions: 0.507-0.119 mm, 0.119-0.063 mm, origin and their morphology were studied by optical and electron microscopy. Organic solvent extracts of the samples were analyzed using gas chromatography to compare the organic compound distribution in fractions. Only slight differences between 2009 and 2010 years are visible. The relatively high extractable part of most investigated elements confirms mobility and potential availability to organisms. The changes can be recognized in the petrographic and organic composition in samples from both years, which were likely the result of various inputs of source materials. Specific organic marker compounds indicate contribution from fossil fuels, plant materials and bacteria. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Honey bee foraging ecology: Season but not landscape diversity shapes the amount and diversity of collected pollen.

    Science.gov (United States)

    Danner, Nadja; Keller, Alexander; Härtel, Stephan; Steffan-Dewenter, Ingolf

    2017-01-01

    The availability of pollen in agricultural landscapes is essential for the successful growth and reproduction of honey bee colonies (Apis mellifera L.). The quantity and diversity of collected pollen can influence the growth and health of honey bee colonies, but little is known about the influence of landscape structure on pollen diet. In a field experiment, we rotated 16 honey bee colonies across 16 agricultural landscapes, used traps to collect samples of collected pollen and observed intra-colonial dance communication to gain information about foraging distances. DNA metabarcoding was applied to analyze mixed pollen samples. Neither the amount of collected pollen nor pollen diversity was related to landscape diversity. However, we found a strong seasonal variation in the amount and diversity of collected pollen in all sites independent of landscape diversity. The observed increase in foraging distances with decreasing landscape diversity suggests that honey bees compensated for lower landscape diversity by increasing their pollen foraging range in order to maintain pollen amount and diversity. Our results underscore the importance of a diverse pollen diet for honey bee colonies. Agri-environmental schemes aiming to support pollinators should focus on possible spatial and temporal gaps in pollen availability and diversity in agricultural landscapes.

  19. Honey bee foraging ecology: Season but not landscape diversity shapes the amount and diversity of collected pollen.

    Directory of Open Access Journals (Sweden)

    Nadja Danner

    Full Text Available The availability of pollen in agricultural landscapes is essential for the successful growth and reproduction of honey bee colonies (Apis mellifera L.. The quantity and diversity of collected pollen can influence the growth and health of honey bee colonies, but little is known about the influence of landscape structure on pollen diet. In a field experiment, we rotated 16 honey bee colonies across 16 agricultural landscapes, used traps to collect samples of collected pollen and observed intra-colonial dance communication to gain information about foraging distances. DNA metabarcoding was applied to analyze mixed pollen samples. Neither the amount of collected pollen nor pollen diversity was related to landscape diversity. However, we found a strong seasonal variation in the amount and diversity of collected pollen in all sites independent of landscape diversity. The observed increase in foraging distances with decreasing landscape diversity suggests that honey bees compensated for lower landscape diversity by increasing their pollen foraging range in order to maintain pollen amount and diversity. Our results underscore the importance of a diverse pollen diet for honey bee colonies. Agri-environmental schemes aiming to support pollinators should focus on possible spatial and temporal gaps in pollen availability and diversity in agricultural landscapes.

  20. Do Strong Unions Shape District Policies? Collective Bargaining, Teacher Contract Restrictiveness, and the Political Power of Teachers' Unions

    Science.gov (United States)

    Strunk, Katharine O.; Grissom, Jason A.

    2010-01-01

    A substantial amount of school district policy is set in the collective bargaining agreements (CBAs) negotiated between teachers' unions and districts. Although previous studies have assumed that CBA provisions bargained by unions are a primary mechanism connecting union strength to outcomes for teachers and students, research has not yet…

  1. High temperature collecting performance of a new all-glass evacuated tubular solar air heater with U-shaped tube heat exchanger

    International Nuclear Information System (INIS)

    Wang, Pin-Yang; Guan, Hong-Yang; Liu, Zhen-Hua; Wang, Guo-San; Zhao, Feng; Xiao, Hong-Sheng

    2014-01-01

    Highlights: • A novel solar air heater with simplified CPC and U-type heat exchanger is designed and tested. • The system is made up of 10 linked collecting panels. • Simplified CPC has a much lower cost at the expense of slight efficiency loss. • The air heater can propose the heated air exceeding 200 °C with great air flow rate. - Abstract: Experiment and simulation are conducted on a new-type all-glass evacuated tubular solar air heater with simplified compound parabolic concentrator (CPC). The system is made up of 10 linked collecting panels and each panel includes a simplified CPC and an all-glass evacuated tube with a U-shaped copper tube heat exchanger installed inside. Air is gradually heated when passing through each U-shaped copper tube. The heat transfer model of the solar air heater is established and the outlet air temperature, the heat power and heat efficiency are calculated. Calculated and experimental results show that the present experimental system can provide the heated air exceeding 200 °C. The whole system has an outstanding high-temperature collecting performance and the present heat transfer model can meet the general requirements of engineering calculations

  2. Elemental analysis of aerosols collected at the Pierre Auger Cosmic Ray Observatory with PIXE technique complemented with SEM/EDX

    Energy Technology Data Exchange (ETDEWEB)

    Micheletti, M.I., E-mail: micheletti@ifir-conicet.gov.ar [Instituto de Fisica Rosario (IFIR) - CONICET/UNR, Bv. 27 de Febrero 210 bis (2000), Rosario (Argentina); Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, UNR, Suipacha 531 (2000), Rosario (Argentina); CONICET (Consejo Nacional de Investigaciones Cientificas y Tecnicas), Avda. Rivadavia 1917 (C1033AAJ), Ciudad Autonoma de Buenos Aires (Argentina); Murruni, L.G. [Servicio Geologico Minero Argentino (SEGEMAR), Buenos Aires (Argentina); Debray, M.E. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499 (1650), San Martin, Buenos Aires (Argentina); Universidad Nacional de Gral. San Martin, M. de Irigoyen 3100 (1650), San Martin, Buenos Aires (Argentina); Rosenbusch, M. [CONICET (Consejo Nacional de Investigaciones Cientificas y Tecnicas), Avda. Rivadavia 1917 (C1033AAJ), Ciudad Autonoma de Buenos Aires (Argentina); Graf, M. [Instituto de Fisica Rosario (IFIR) - CONICET/UNR, Bv. 27 de Febrero 210 bis (2000), Rosario (Argentina); and others

    2012-10-01

    The aim of this work is to characterize surface aerosols at the Pierre Auger Cosmic Ray Observatory located at Pampa Amarilla, near Malarguee city, in the Andes region of Argentina, with experimental sampling techniques used for the first time in a cosmic ray observatory, adding to information provided by the existing Auger aerosol monitors. A good knowledge of the optical attenuation due to aerosols is crucial for a good reconstruction of the signals from cosmic ray showers detected by the fluorescence detectors of the Observatory. Aerosols were collected in filters, during the Southern Hemisphere winter and spring in 2008. Concentrations in PM2.5 and PM2.5-10 filters were determined by gravimetric analysis and their elemental composition by the PIXE technique, complemented with SEM/EDX. Low aerosol concentrations were measured during the sampling period. The mean total mass PM10 (=PM2.5 + PM2.5-10 fractions) value was [mean(se)] 9.8(1.0) {mu}g/m{sup 3} [sd = 5.9 {mu}g/m{sup 3}]. The mean PM10 value during winter was 7(1.1) {mu}g/m{sup 3} [sd = 4.5 {mu}g/m{sup 3}], about half of the 13.1(1.5) [sd = 5.7 {mu}g/m{sup 3}] measured during springtime. The PM2.5 fraction was approximately 30% of the PM10 fraction. PIXE results gave levels of S, Cl, K, Ca, Ti, Mn, Fe in the analyzed aerosol samples, showing that these elements correspond to 25% and 13% of the PM2.5 and PM2.5-10 total mass respectively. The rest of the mass was due to the elements with low Z (below 16) which cannot be detected by our X-ray setup. Comparison with SEM/EDX analysis showed that most of them were Si and Al (aluminosilicates). Our results indicate that most of the aerosols at the Auger Observatory would most likely come from the soil of the region. Due to its vast atmospheric monitoring network, the Auger Observatory is an interesting reference site for further atmospheric studies.

  3. A social identity approach to person memory: group membership, collective identification, and social role shape attention and memory.

    Science.gov (United States)

    Van Bavel, Jay J; Cunningham, William A

    2012-12-01

    Evidence indicates that superior memory for own-group versus other-group faces (termed own-group bias) occurs because of social categorization: People are more likely to encode own-group members as individuals. The authors show that aspects of the perceiver's social identity shape social attention and memory over and above mere categorization. In three experiments, participants were assigned to a mixed-race minimal group and showed own-group bias toward this minimal group, regardless of race. Own-group bias was mediated by attention toward own-group faces during encoding (Experiment 1). Furthermore, participants who were highly identified with their minimal group had the largest own-group bias (Experiment 2). However, social affordances attenuated own-group bias-Memory for other-group faces was heightened among participants who were assigned to a role (i.e., spy) that required attention toward other-group members (Experiment 3). This research suggests that social identity may provide novel insights into person memory.

  4. General quadrupole shapes in the Interacting Boson Model

    International Nuclear Information System (INIS)

    Leviatan, A.

    1990-01-01

    Characteristic attributes of nuclear quadrupole shapes are investigated within the algebraic framework of the Interacting Boson Model. For each shape the Hamiltonian is resolved into intrinsic and collective parts, normal modes are identified and intrinsic states are constructed and used to estimate transition matrix elements. Special emphasis is paid to new features (e.g. rigid triaxiality and coexisting deformed shapes) that emerge in the presence of the three-body interactions. 27 refs

  5. General quadrupole shapes in the Interacting Boson Model

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A.

    1990-01-01

    Characteristic attributes of nuclear quadrupole shapes are investigated within the algebraic framework of the Interacting Boson Model. For each shape the Hamiltonian is resolved into intrinsic and collective parts, normal modes are identified and intrinsic states are constructed and used to estimate transition matrix elements. Special emphasis is paid to new features (e.g. rigid triaxiality and coexisting deformed shapes) that emerge in the presence of the three-body interactions. 27 refs.

  6. Investigation on the Cyclic Response of Superelastic Shape Memory Alloy (SMA Slit Damper Devices Simulated by Quasi-Static Finite Element (FE Analyses

    Directory of Open Access Journals (Sweden)

    Jong Wan Hu

    2014-02-01

    Full Text Available In this paper, the superelastic shape memory alloy (SMA slit damper system as an alternative design approach for steel structures is intended to be evaluated with respect to inelastic behavior simulated by refined finite element (FE analyses. Although the steel slit dampers conventionally used for aseismic design are able to dissipate a considerable amount of energy generated by the plastic yielding of the base materials, large permanent deformation may occur in the entire structure. After strong seismic events, extra damage repair costs are required to restore the original configuration and to replace defective devices with new ones. Innovative slit dampers fabricated by superelastic SMAs that automatically recover their initial conditions only by the removal of stresses without heat treatment are introduced with a view toward mitigating the problem of permanent deformation. The cyclically tested FE models are calibrated to experimental results for the purpose of predicting accurate behavior. This study also focuses on the material constitutive model that is able to reproduce the inherent behavior of superelastic SMA materials by taking phase transformation between austenite and martensite into consideration. The responses of SMA slit dampers are compared to those of steel slit dampers. Axial stress and strain components are also investigated on the FE models under cyclic loading in an effort to validate the adequacy of FE modeling and then to compare between two slit damper systems. It can be shown that SMA slit dampers exhibit many structural advantages in terms of ultimate strength, moderate energy dissipation and recentering capability.

  7. Elemental Mixing State of Aerosol Particles Collected in Central Amazonia during GoAmazon2014/15

    Energy Technology Data Exchange (ETDEWEB)

    Fraund, Matthew; Pham, Don; Bonanno, Daniel; Harder, Tristan; Wang, Bingbing; Brito, Joel; de Sá, Suzane; Carbone, Samara; China, Swarup; Artaxo, Paulo; Martin, Scot; Pöhlker, Christopher; Andreae, Meinrat; Laskin, Alexander; Gilles, Mary; Moffet, Ryan

    2017-09-01

    Two complementary techniques, Scanning Transmission X-ray Microscopy/Near Edge Fine Structure spectroscopy (STXM/NEXAFS) and Scanning Electron Microscopy/Energy Dispersive X-ray spectroscopy (SEM/EDX), have been quantitatively combined to characterize individual atmospheric particles. This pair of techniques was applied to particle samples at three sampling sites (ATTO, ZF2, and T3) in the Amazon basin as part of the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) field campaign during the dry season of 2014. The combined data was subjected to k-means clustering using mass fractions of the following elements: C, N, O, Na, Mg, P, S, Cl, K, Ca, Mn, Fe, Ni, and Zn. Cluster analysis identified 12 particle types, across different sampling sites and particle sizes. Samples from the remote Amazon Tall Tower Observatory (ATTO, also T0a) exhibited less cluster variety and fewer anthropogenic clusters than samples collected at the sites nearer to the Manaus metropolitan region, ZF2 (also T0t) or T3. Samples from the ZF2 site contained aged/anthropogenic clusters not readily explained by transport from ATTO or Manaus, possibly suggesting the effects of long range atmospheric transport or other local aerosol sources present during sampling. In addition, this data set allowed for recently established diversity parameters to be calculated. All sample periods had high mixing state indices (χ) that were >0.8. Two individual particle diversity (Di) populations were observed, with particles <0.5 μm having a Di of ~2.4 and >0.5 μm particles having a Di of ~3.6, which likely correspond to fresh and aged aerosols respectively. The diversity parameters determined by the quantitative method presented here will serve to aid in the accurate representation of aerosol mixing state, source apportionment, and aging in both less polluted and more industrialized environments in the Amazon Basin.

  8. MUC1 marks collecting tubules, renal vesicles, comma- and S-shaped bodies in human developing kidney tubules, renal vesicles, comma- and s-shaped bodies in human kidney.

    Science.gov (United States)

    Fanni, D; Iacovidou, N; Locci, A; Gerosa, C; Nemolato, S; Van Eyken, P; Monga, G; Mellou, S; Faa, G; Fanos, V

    2012-10-26

    MUC1 is a transmembrane glycoprotein, apically expressed in most epithelial cells, used in the differential diagnosis of carcinomas and for discrimination of tumors of non-epithelial origin showing epithelioid features. Little attention has been paid so far though, on its possible significance in embryonic tissues. A preliminary study from our group revealed MUC1 expression in the cap mesenchymal cells during human nephrogenesis, suggesting a role for MUC1 in the process of mesenchymal-to-epithelial transition. This study aimed at investigating the expression pattern of MUC1 in various developing structures of human fetal kidney. Expression of MUC1 was examined in kidneys of 5 human fetuses. MUC1 immunoreactivity was detected in ureteric bud tips, in collecting tubules, in cap mesenchymal cells undergoing the initial phases of mesenchymal-to-epithelial transition, in renal vesicles, comma-bodies, and S-shaped bodies. Our previous preliminary report suggested a role for MUC1 in the initial phases of the process of mesenchymal-to-epithelial transition. The present data suggest that MUC1 expression characterizes multiple structures during human nephrogenesis, from the ureteric bud, to the initial phases of mesenchymal-to-epithelial transition and that MUC1 should be added to the genes activated during the process of mesenchymal-to-epithelial transition in the cap mesenchyme of human kidney.

  9. Issues in Biological Shape Modelling

    DEFF Research Database (Denmark)

    Hilger, Klaus Baggesen

    This talk reflects parts of the current research at informatics and Mathematical Modelling at the Technical University of Denmark within biological shape modelling. We illustrate a series of generalizations, modifications, and applications of the elements of constructing models of shape or appear......This talk reflects parts of the current research at informatics and Mathematical Modelling at the Technical University of Denmark within biological shape modelling. We illustrate a series of generalizations, modifications, and applications of the elements of constructing models of shape...

  10. Determination by activation analysis of volatile metals and other elements in volcanic exhalations collected at Vulcano and Stromboli, Italy

    International Nuclear Information System (INIS)

    Bichler, M.; Platschka, R.; Poljanc, K.

    1992-01-01

    Hot gases of volcanic origin (fumaroles) were sampled by means of an activated charcoal filter. The charcoal was specially prepared by a high temperature - vacuum treatment. Mercury, arsenic, bromine, antimony and selenium were determined by activation analysis and compared with literature values. A lightweight pumping station was developed to enable transport to the crater regions of Stromboli and Vulcano. The teflon membrane pump is driven by wind. The filter unit, a specially shaped quartz glass tube, was lowered into the hot vents. The temperature of the sampled fumaroles was 100 to 330 deg C. (author) 11 refs.; 4 figs.; 2 tabs

  11. Air pollution studies in terms of particulate matters, elements and black carbon in the aerosols collected at Andravoahangy-Antananarivo

    International Nuclear Information System (INIS)

    HARINOELY, M.

    2012-01-01

    This work was performed at the Institut National des Sciences et Techniques Nucleaires (Madagascar-INSTN) in the framework of RAF/4/019 project organized by the International Atomic Energy Agency. The main objective of this work is to study the level of air pollution in terms of particulate matters, elements and black carbon in the site of Andravoahangy-Antananarivo and to transmit the results obtained to the competent authorities so that they can make decisions to reduce the impacts of air pollution on the population. The total reflection X-ray fluorescence spectrometer is used for qualitative and quantitative analyses of the elements contained in the aerosols and the reflectometer M43D for the determination of the black carbon concentrations. The results showed that the average concentrations of the particulate matters PM 2,5-10 are higher than those of PM 2,5 . The average concentrations of PM 10 in the aerosols are exceeding the World Health Organisation (WHO) and European Union guidelines, set at 50 μg.m -3 and those of PM 2,5 are higher than the 2005 WHO (25 μg.m -3 ) and the United States Environmental Protection Agency (35 μg.m -3 ) guidelines. The identified elements in the aerosols are Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr and Pb. The average concentrations of these elements are also higher in the coarse particles than in the fine particles. The concentrations of black carbon are higher in the fine particles, with a maximum value of 9.12 μg.m -3 . [fr

  12. Solubility of iron and other trace elements in rainwater collected on the Kerguelen Islands (South Indian Ocean

    Directory of Open Access Journals (Sweden)

    A. Heimburger

    2013-10-01

    Full Text Available The soluble fraction of aerosols that is deposited on the open ocean is vital for phytoplankton growth. It is believed that a large proportion of this dissolved fraction is bioavailable for marine biota and thus plays an important role in primary production, especially in HNLC oceanic areas where this production is limited by micronutrient supply. There is still much uncertainty surrounding the solubility of atmospheric particles in global biogeochemical cycles and it is not well understood. In this study, we present the solubilities of seven elements (Al, Ce, Fe, La, Mn, Nd, Ti in rainwater on the Kerguelen Islands, in the middle of the Southern Indian Ocean. The solubilities of elements exhibit high values, generally greater than 70%, and Ti remains the least soluble element. Because the Southern Indian Ocean is remote from its dust sources, only a fraction of smaller aerosols reaches the Kerguelen Islands after undergoing several cloud and chemical processes during their transport, resulting in a drastic increase in solubility. Finally, we deduced an average soluble iron deposition flux of 27 ± 6 μg m−2 d−1 (~0.5 μmol m−2 d−1 for the studied oceanic area, taking into account a median iron solubility of 82% ± 18%.

  13. Updated study reporting levels (SRLs) for trace-element data collected for the California Groundwater Ambient Monitoring and Assessment (GAMA) Priority Basin Project, October 2009-March 2013

    Science.gov (United States)

    Davis, Tracy A.; Olsen, Lisa D.; Fram, Miranda S.; Belitz, Kenneth

    2014-01-01

    Groundwater samples have been collected in California as part of statewide investigations of groundwater quality conducted by the U.S. Geological Survey for the Groundwater Ambient Monitoring and Assessment (GAMA) Priority Basin Project (PBP). The GAMA-PBP is being conducted in cooperation with the California State Water Resources Control Board to assess and monitor the quality of groundwater resources used for drinking-water supply and to improve public knowledge of groundwater quality in California. Quality-control samples (source-solution blanks, equipment blanks, and field blanks) were collected in order to ensure the quality of the groundwater sample results. Olsen and others (2010) previously determined study reporting levels (SRLs) for trace-element results based primarily on field blanks collected in California from May 2004 through January 2008. SRLs are raised reporting levels used to reduce the likelihood of reporting false detections attributable to contamination bias. The purpose of this report is to identify any changes in the frequency and concentrations of detections in field blanks since the last evaluation and update the SRLs for more recent data accordingly. Constituents analyzed were aluminum (Al), antimony (Sb), arsenic (As), barium (Ba), beryllium (Be), boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), silver (Ag), strontium (Sr), thallium (Tl), tungsten (W), uranium (U), vanadium (V), and zinc (Zn). Data from 179 field blanks and equipment blanks collected from March 2006 through March 2013 by the GAMA-PBP indicated that for trace elements that had a change in detection frequency and concentration since the previous review, the shift occurred near October 2009, in conjunction with a change in the capsule filters used by the study. Results for 89 field blanks and equipment blanks collected from October 2009 through March 2013 were

  14. Human vocal tract resonances and the corresponding mode shapes investigated by three-dimensional finite-element modelling based on CT measurement

    Czech Academy of Sciences Publication Activity Database

    Vampola, T.; Horáček, Jaromír; Laukkanen, A. M.; Švec, J. G.

    2015-01-01

    Roč. 40, č. 1 (2015), s. 14-23 ISSN 1401-5439 R&D Projects: GA ČR(CZ) GAP101/12/1306 Institutional support: RVO:61388998 Keywords : acoustic mode shapes of vibration * speaker's and singer's formant * biomechanics of human voice * voice production modelling Subject RIV: BI - Acoustics Impact factor: 0.750, year: 2015

  15. Review of Trace-Element Field-Blank Data Collected for the California Groundwater Ambient Monitoring and Assessment (GAMA) Program, May 2004-January 2008

    Science.gov (United States)

    Olsen, Lisa D.; Fram, Miranda S.; Belitz, Kenneth

    2010-01-01

    Trace-element quality-control samples (for example, source-solution blanks, field blanks, and field replicates) were collected as part of a statewide investigation of groundwater quality in California, known as the Priority Basins Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basins Project is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB) to assess and monitor the quality of groundwater resources used for drinking-water supply and to improve public knowledge of groundwater quality in California. Trace-element field blanks were collected to evaluate potential bias in the corresponding environmental data. Bias in the environmental data could result from contamination in the field during sample collection, from the groundwater coming into contact with contaminants on equipment surfaces or from other sources, or from processing, shipping, or analyzing the samples. Bias affects the interpretation of environmental data, particularly if any constituents are present solely as a result of extrinsic contamination that would have otherwise been absent from the groundwater that was sampled. Field blanks were collected, analyzed, and reviewed to identify and quantify extrinsic contamination bias. Data derived from source-solution blanks and laboratory quality-control samples also were considered in evaluating potential contamination bias. Eighty-six field-blank samples collected from May 2004 to January 2008 were analyzed for the concentrations of 25 trace elements. Results from these field blanks were used to interpret the data for the 816 samples of untreated groundwater collected over the same period. Constituents analyzed were aluminum (Al), antimony (Sb), arsenic (As), barium (Ba), beryllium (Be), boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), lithium (Li), manganese (Mn), mercury (Hg), molybdenum

  16. Fractionation of trace elements and human health risk of submicron particulate matter (PM1) collected in the surroundings of coking plants.

    Science.gov (United States)

    Zajusz-Zubek, Elwira; Radko, Tomasz; Mainka, Anna

    2017-08-01

    Samples of PM1 were collected in the surroundings of coking plants located in southern Poland. Chemical fractionation provided information on the contents of trace elements As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Sb and Se in all mobile (F1-F3) and not mobile (F4) fractions of PM1 in the vicinity of large sources of emissions related to energochemical processing of coal during the summer. The determined enrichment factors indicate the influence of anthropogenic sources on the concentration of the examined elements contained in PM1 in the areas subjected to investigation. The analysis of health risk for the assumed scenario of inhabitant exposure to the toxic effect of elements, based on the values of the hazard index, revealed that the absorption of the examined elements contained in the most mobile fractions of particulate matter via inhalation by children and adults can be considered potentially harmless to the health of people inhabiting the surroundings of coking plants during the summer (HI PM1, approximately four adults and one child out of one million people living in the vicinity of the coking plants may develop cancer.

  17. Gas cooled high temperature reactor with a heap of pebble shaped fuel elements and absorber rods which can be driven directly into the heap of pebbles

    International Nuclear Information System (INIS)

    Elter, C.; Schmitt, H.; Schoening, J.; Weicht, U.

    1980-01-01

    The absorber rod for the graphite moderated, helium cooled reactor is cylindrical and has a tip in the shape of the frustrum of a cone. It consists of three coaxially arranged sleeve tubes made of steel, the inner and centre sleeve tubes surrounding the absorber part (B4C) so as to be gastight. The inner sleeve tube represents the supporting tube and is cooled by cold gas, as is the annular gap between the centre and outer sleeve tube. (RW) [de

  18. Influence of easily ionised elements on the delayed responses of the emission intensities of an analyte in a power modulated U-shaped argon stabilised DC arc plasma with an aerosol supply

    Directory of Open Access Journals (Sweden)

    MIROSLAV KUZMANOVIC

    2005-09-01

    Full Text Available The current of a U-shaped argon stabilised DC arc was square modulated with a 40 Hz repetition frequency between 6 and 3 A. The delayed line intensity responses to the modulation of the arc current were investigated using calcium as a representative analyte. The intensities of both the atomic and ionic lines were monitored at different distances from the arc axis in the presence of various concentrations of the easily ionised element. Temporal evolutions were monitored on a millisecond time scale. It was found that the responses of the line intesity to the arc current change strongly depended on the observed radial position, especially in the vicinity of the arc axis. The obtained results showed a significant influence of even small amounts of the easily ionised element on the excitation and transport of the analyte and indicated a way of possibly improving the analytical capabilities of the excitation source.

  19. Trace Element Concentrations in Tree Leaves and Lichen Collected Along a Metal Pollution Gradient Near Olkusz (Southern Poland).

    Science.gov (United States)

    Zakrzewska, Marta; Klimek, Beata

    2018-02-01

    The aim of the study was to assess the metal pollution in the vicinity of the Bukowno smelter near Olkusz in southern Poland. Birch and oak leaves, pine needles and a lichen Hypogymnia physodes, overgrowing pine bark were collected at stands at different distances from the smelter and analysed for cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) content. Concentrations of metals in the lichen were usually higher than in the tree leaves/needles and decreased with distance from the smelter, apart from the Cu content. The strongest correlation was noticed between Cd and Pb concentrations, which indicates a common pollution source (the smelter). Our results show that birch leaves can be potentially useful as a bioindicator of Zn air pollution since this species was shown to accumulate high amounts of zinc, related to environmental pollution with that metal, in their leaves.

  20. A comprehensive study of MPI parallelism in three-dimensional discrete element method (DEM) simulation of complex-shaped granular particles

    Science.gov (United States)

    Yan, Beichuan; Regueiro, Richard A.

    2018-02-01

    A three-dimensional (3D) DEM code for simulating complex-shaped granular particles is parallelized using message-passing interface (MPI). The concepts of link-block, ghost/border layer, and migration layer are put forward for design of the parallel algorithm, and theoretical scalability function of 3-D DEM scalability and memory usage is derived. Many performance-critical implementation details are managed optimally to achieve high performance and scalability, such as: minimizing communication overhead, maintaining dynamic load balance, handling particle migrations across block borders, transmitting C++ dynamic objects of particles between MPI processes efficiently, eliminating redundant contact information between adjacent MPI processes. The code executes on multiple US Department of Defense (DoD) supercomputers and tests up to 2048 compute nodes for simulating 10 million three-axis ellipsoidal particles. Performance analyses of the code including speedup, efficiency, scalability, and granularity across five orders of magnitude of simulation scale (number of particles) are provided, and they demonstrate high speedup and excellent scalability. It is also discovered that communication time is a decreasing function of the number of compute nodes in strong scaling measurements. The code's capability of simulating a large number of complex-shaped particles on modern supercomputers will be of value in both laboratory studies on micromechanical properties of granular materials and many realistic engineering applications involving granular materials.

  1. Assessment of trace element levels in muscle tissues of fish species collected from a river, stream, lake, and sea in Sakarya, Turkey.

    Science.gov (United States)

    Küpeli, Tülay; Altundağ, Hüseyin; Imamoğlu, Mustafa

    2014-01-01

    Levels of some trace and essential elements, including Al, B, Ba, Cr, Cu, Fe, Mn, Ni, Sr, and Zn, were determined in 17 different fish species from Sakarya River, Çark Stream, Sapanca Lake, and Western Black Sea using ICP-OES after microwave (MW) digestion procedure. During preparation of samples for analysis, wet and MW digestion methods were also compared. Accuracy of the digestion methods was checked by the analysis of DORM-3 reference material (Fish Protein Certified Reference Material for Trace Metals). Concentrations of trace elements were found as Al: 6.5-48.5, B: 0.06-3.30, Ba: 0.09-2.92, Cr: 0.02-1.64, Cu: 0.13-2.28, Fe: 7.28-39.9, Mn: 0.08-11.4, Ni: 0.01-26.1, Sr: 0.17-13.5, and Zn: 11.5-52.9 µg g(-1). The obtained results were compared with other studies published in the literature. Trace element levels in various fish species collected from waters in Sakarya region were found to be below limit values provided by Turkish Food Codex (TFC), Food and Agriculture Organization (FAO), and World Health Organization (WHO).

  2. Determination of water-soluble elements in PM2.5, PM10, and PM2.5-10 collected in the surroundings of power plants

    Science.gov (United States)

    Zajusz-Zubek, Elwira; Mainka, Anna; Kaczmarek, Konrad

    2018-01-01

    The analysis reported in this study was performed to characterize the concentrations and water-soluble content of trace elements (As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Sb and Se) in PM2.5, PM10 and PM2.5-10 samples collected in the surroundings of power plants in southern Poland. The solubility of trace elements bound to PM2.5 and PM10 was higher than for PM2.5-10, and in most cases, significant differences were revealed in the relative percentage concentrations of the water-soluble fractions. The occurrence of Cd, Cr, Mn, Ni, Pb and Se in first PCA (Principal Component Analysis) factor (PC1) - indicate coal combustion processes as the potential source of these elements. Other factors indicate two further anthropogenic sources: the resuspension of road dust due to vehicular activities and waste burning in domestic sources - factor (PC2), and, soil dust sources affected by fugitive dust from the mining processes and unpaved roads, as well as transportation and deposition of coal -factor (PC3).

  3. Assessment of Trace Element Levels in Muscle Tissues of Fish Species Collected from a River, Stream, Lake, and Sea in Sakarya, Turkey

    Directory of Open Access Journals (Sweden)

    Tülay Küpeli

    2014-01-01

    Full Text Available Levels of some trace and essential elements, including Al, B, Ba, Cr, Cu, Fe, Mn, Ni, Sr, and Zn, were determined in 17 different fish species from Sakarya River, Çark Stream, Sapanca Lake, and Western Black Sea using ICP-OES after microwave (MW digestion procedure. During preparation of samples for analysis, wet and MW digestion methods were also compared. Accuracy of the digestion methods was checked by the analysis of DORM-3 reference material (Fish Protein Certified Reference Material for Trace Metals. Concentrations of trace elements were found as Al: 6.5–48.5, B: 0.06–3.30, Ba: 0.09–2.92, Cr: 0.02–1.64, Cu: 0.13–2.28, Fe: 7.28–39.9, Mn: 0.08–11.4, Ni: 0.01–26.1, Sr: 0.17–13.5, and Zn: 11.5–52.9 µg g−1. The obtained results were compared with other studies published in the literature. Trace element levels in various fish species collected from waters in Sakarya region were found to be below limit values provided by Turkish Food Codex (TFC, Food and Agriculture Organization (FAO, and World Health Organization (WHO.

  4. Common data elements for preclinical epilepsy research: Standards for data collection and reporting. A TASK3 report of the AES/ILAE Translational Task Force of the ILAE.

    Science.gov (United States)

    Harte-Hargrove, Lauren C; French, Jacqueline A; Pitkänen, Asla; Galanopoulou, Aristea S; Whittemore, Vicky; Scharfman, Helen E

    2017-11-01

    The major objective of preclinical translational epilepsy research is to advance laboratory findings toward clinical application by testing potential treatments in animal models of seizures and epilepsy. Recently there has been a focus on the failure of preclinical discoveries to translate reliably, or even to be reproduced in different laboratories. One potential cause is a lack of standardization in preclinical data collection. The resulting difficulties in comparing data across studies have led to high cost and missed opportunity, which in turn impede clinical trials and advances in medical care. Preclinical epilepsy research has successfully brought numerous antiseizure treatments into the clinical practice, yet the unmet clinical needs have prompted the reconsideration of research strategies to optimize epilepsy therapy development. In the field of clinical epilepsy there have been successful steps to improve such problems, such as generation of common data elements (CDEs) and case report forms (CRFs and standards of data collection and reporting) by a team of leaders in the field. Therefore, the Translational Task Force was appointed by the International League Against Epilepsy (ILAE) and the American Epilepsy Society (AES), in partnership with the National Institute of Neurological Disorders and Stroke (NINDS) and the National Institutes of Health (NIH) to define CDEs for animal epilepsy research studies and prepare guidelines for data collection and experimental procedures. If adopted, the preclinical CDEs could facilitate collaborative epilepsy research, comparisons of data across different laboratories, and promote rigor, transparency, and impact, particularly in therapy development. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  5. Forward problem solution as the operator of filtered and back projection matrix to reconstruct the various method of data collection and the object element model in electrical impedance tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ain, Khusnul [Engineering Physics Program, ITB, Bandung - Indonesia (Indonesia); Physics Department - Airlangga University, Surabaya – Indonesia, khusnulainunair@yahoo.com (Indonesia); Kurniadi, Deddy; Suprijanto [Engineering Physics Program, ITB, Bandung - Indonesia (Indonesia); Santoso, Oerip [Informatics Program, ITB, Bandung - Indonesia (Indonesia); Wibowo, Arif [Physics Department - Airlangga University, Surabaya – Indonesia, khusnulainunair@yahoo.com (Indonesia)

    2015-04-16

    Back projection reconstruction has been implemented to get the dynamical image in electrical impedance tomography. However the implementation is still limited in method of adjacent data collection and circular object element model. The study aims to develop the methods of back projection as reconstruction method that has the high speed, accuracy, and flexibility, which can be used for various methods of data collection and model of the object element. The proposed method uses the forward problem solution as the operator of filtered and back projection matrix. This is done through a simulation study on several methods of data collection and various models of the object element. The results indicate that the developed method is capable of producing images, fastly and accurately for reconstruction of the various methods of data collection and models of the object element.

  6. An automated method to morph finite element whole-body human models with a wide range of stature and body shape for both men and women.

    Science.gov (United States)

    Zhang, Kai; Cao, Libo; Fanta, Abeselom; Reed, Matthew P; Neal, Mark; Wang, Jenne-Tai; Lin, Chin-Hsu; Hu, Jingwen

    2017-07-26

    Field data analyses have shown that small female, obese, and/or older occupants are at increased risks of death and serious injury in motor-vehicle crashes compared with mid-size young men. The current adult finite element (FE) human models represent occupants in the same three body sizes (large male, mid-size male, and small female) as those for the contemporary adult crash dummies. Further, the time needed to develop an FE human model using the traditional method is measured in months or even years. In the current study, an improved regional mesh morphing method based on landmark-based radial basis function (RBF) interpolation was developed to rapidly morph a mid-size male FE human model into different geometry targets. A total of 100 human models with a wide range of human attributes were generated. A pendulum chest impact condition was applied to each model as an initial assessment of the resulting variability in response. The morphed models demonstrated mesh quality similar to the baseline model. The peak impact forces and chest deflections in the chest pendulum impacts varied substantially with different models, supportive of consideration of population variation in evaluating the occupant injury risks. The method developed in this study will enable future safety design optimizations targeting at various vulnerable populations that cannot be considered with the current models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Effect of Sn and Sb element on the magnetism and functional properties of Ni–Mn–Al ferromagnetic shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Sandeep, E-mail: sandeepxag@yahoo.co.in [LCMP, Department of Condensed Matter Physics and Material Sciences, SN Bose National Centre for Basic Sciences, JD Block, Salt Lake, Kolkata 700098 (India); Mukhopadhyay, P.K. [LCMP, Department of Condensed Matter Physics and Material Sciences, SN Bose National Centre for Basic Sciences, JD Block, Salt Lake, Kolkata 700098 (India)

    2016-03-15

    We have replaced Al partially with Sb and Sn in Ni–Mn–Al systems and investigated its effect on magnetism, entropy change and magnetoresistance in the vicinity of martensitic transformation. Both the samples had identical lattice parameters and Mn contents, which are mostly responsible for magnetism in these systems, yet there were marked changes in magnetic and functional properties of these systems. It was found that the magnetization increased in Sb alloy, while entropy change and magnetoresistance decreased as compared to Sn alloy. These changes are attributed to the change in antiferromagnetic interaction as a result of variation in the Ni d–Mn d hybridization arising due to presence of different sp elements. - Highlights: • Sn and Sb system has same Mn and Ni content and lattice parameter. • Both systems has disparity in magnetism, entropy change and magnetoresistance. • Difference was due to change in the Ni 3d–Mn 3d hybridization. • Sb based alloys are more suitable for mechanical devices. • Sn based alloys are more suitable for magnetocaloric effect and magnetoresistance.

  8. Shape descriptors for mode-shape recognition and model updating

    International Nuclear Information System (INIS)

    Wang, W; Mottershead, J E; Mares, C

    2009-01-01

    The most widely used method for comparing mode shapes from finite elements and experimental measurements is the Modal Assurance Criterion (MAC), which returns a single numerical value and carries no explicit information on shape features. New techniques, based on image processing (IP) and pattern recognition (PR) are described in this paper. The Zernike moment descriptor (ZMD), Fourier descriptor (FD), and wavelet descriptor (WD), presented in this article, are the most popular shape descriptors having properties that include efficiency of expression, robustness to noise, invariance to geometric transformation and rotation, separation of local and global shape features and computational efficiency. The comparison of mode shapes is readily achieved by assembling the shape features of each mode shape into multi-dimensional shape feature vectors (SFVs) and determining the distances separating them.

  9. Evolution of nuclear shapes at high spins

    International Nuclear Information System (INIS)

    Johnson, N.R.

    1985-01-01

    The dynamic electric quadrupole (E2) moments are a direct reflection of the collective aspects of the nuclear wave functions. For this, Doppler-shift lifetime measurements have been done utilizing primarily the recoil-distance technique. The nuclei with neutron number N approx. 90 possess many interesting properties. These nuclei have very shallow minima in their potential energy surfaces, and thus, are very susceptible to deformation driving influences. It is the evolution of nuclear shapes as a function of spin or rotational frequency for these nuclei that has commanded much interest in the lifetime measurements discussed here. There is growing evidence that many deformed nuclei which have prolate shapes in their ground states conform to triaxial or oblate shapes at higher spins. Since the E2 matrix elements along the yrast line are sensitive indicators of deformation changes, measurements of lifetimes of these states to provide the matrix elements has become the major avenue for tracing the evolving shape of a nucleus at high spin. Of the several nuclei we have studied with N approx. 90, those to be discussed here are /sup 160,161/Yb and 158 Er. In addition, the preliminary, but interesting and surprising results from our recent investigation of the N = 98 nucleus, 172 W are briefly discussed. 14 refs., 5 figs

  10. Major- and trace-element concentrations in rock samples collected in 2004 from the Taylor Mountains 1:250,000-scale quadrangle, Alaska

    Science.gov (United States)

    Klimasauskas, Edward P.; Miller, Marti L.; Bradley, Dwight C.; Karl, Sue M.; Baichtal, James F.; Blodgett, Robert B.

    2006-01-01

    The Kuskokwim mineral belt of Bundtzen and Miller (1997) forms an important metallogenic region in southwestern Alaska that has yielded more than 3.22 million ounces of gold and 400,000 ounces of silver. Precious-metal and related deposits in this region associated with Late Cretaceous to early Tertiary igneous complexes extend into the Taylor Mountains 1:250,000-scale quadrangle. The U.S. Geological Survey is conducting geologic mapping and a mineral resource assessment of this area that will provide a better understanding of the geologic framework, regional geochemistry, and may provide targets for mineral exploration and development. During the 2004 field season 137 rock samples were collected for a variety of purposes. The 4 digital files accompanying this report reflect the type of analysis performed and its intended purpose and are available for download as an Excel workbook, comma delimited format (*.csv), dBase 4 files (*.dbf) or as point coverages in ArcInfo interchange format (*.e00). Data values are provided in percent, pct (1gram per 100grams), or parts per million, ppm (1gram per 1,000,000grams) per the column heading in the table. All samples were analyzed for a suite of 42 trace-elements (icp42.*) to provide data for use in geochemical exploration as well as some baseline data. Selected samples were analyzed by additional methods; 104 targeted geochemical exploration samples were analyzed for gold, arsenic, and mercury (auashg.*); 21 of these samples were also analyzed to obtain concentrations of 10 loosely bound metals (icp10.*); 33 rock samples were analyzed for major element oxides to support the regional mapping program (reg.*), of which 28 sedimentary rock samples were also analyzed for total carbon, and carbonate carbon.

  11. Schapiro Shapes

    Science.gov (United States)

    O'Connell, Emily

    2009-01-01

    This article describes a lesson on Schapiro Shapes. Schapiro Shapes is based on the art of Miriam Schapiro, who created a number of works of figures in action. Using the basic concepts of this project, students learn to create their own figures and styles. (Contains 1 online resource.)

  12. Comparison of leaves of Nerium oleander collected the monitoring trace elements in environmental pollution in Rio de Janeiro and Campinas Cities using of synchrotron radiation fluorescence analysis

    International Nuclear Information System (INIS)

    Simabuco, Silvana M.; Ferreira Pinto, Jefferson; Dos Anjos, Marcelino J.

    1999-01-01

    These works describes the use of synchrotron radiation fluorescence analysis as a technique for monitoring trace elements in bio-indicators for environmental pollution control. The analyses were made on leaves of Nerium oleander collected in streets with different traffic flow in Rio de Janeiro and Campinas Cities, Brazil, with one sample from rural zone. Part of the leaves were cleaned with 0,1% v/v detergent in deionized water and than all were dry at 60o C until constant weight. The leaves were than cut in small pieces and submitted to a nitric digestion in a open system. The liquid residue was pre-concentrated with ammonium pirrrolidine dithiocarbamate and filtrated by vacuum pump in cellulose membrane. The measurement was made with a white beam of synchrotron radiation calibrated with thin film standards. The results indicate that same metals like Ti, V, Fe and Zn have major content in sample that came from places with high traffic flow even in leaves that have been washed. The levels of Mn, Co, Cu and Ni did not show significant difference between the samples. The Pb level also did not vary significantly what was expected because in Brazil the gasoline did not use plumb as a additive from many years. The results seems to indicate that the leaves from Nerium oleander absorb metals from the atmosphere and may be used as one environmental indicator

  13. Synthesis of novel chitosan resin derivatized with serine diacetic acid moiety and its application to on-line collection/concentration of trace elements and their determination using inductively coupled plasma-atomic emission spectrometry.

    Science.gov (United States)

    Hakim, Lukman; Sabarudin, Akhmad; Oshima, Mitsuko; Motomizu, Shoji

    2007-04-04

    A novel chelating resin functionalized with serine diacetic acid moiety was synthesized by using chitosan as base material, and applied to the collection/concentration of trace elements in environmental water samples, followed by the determination using inductively coupled plasma-atomic emission spectrometer (ICP-AES). The synthesized resin, crosslinked chitosan serine diacetic acid (CCTS-SDA), showed good adsorption behavior toward trace amounts of Cd, Pb, Cu, Ni, V, Ga, Sc, In, and Th in a wide pH range. Additionally, rare earth elements also can be retained on the resin at neutral pH region. The adsorbed elements can be easily eluted with 1 mol L(-1) of nitric acid, and their recoveries were found to be 90-100%. The CCTS-SDA was packed in a mini-column, which was then installed in a computer-controlled auto-pretreatment system (Auto-Pret System) for on-line trace elements collection and determination with ICP-AES. Experimental parameters which related to the improvement of sensitivity and reproducibility were optimized. The limits of detection (LOD) for 13 elements were found to be in sub-ppb level. The proposed method with CCTS-SDA resin was successfully applied to the determination of trace elements in river water samples. The method was validated by determining a certified reference material of river water, SLRS-4.

  14. Combined Shape and Topology Optimization

    DEFF Research Database (Denmark)

    Christiansen, Asger Nyman

    Shape and topology optimization seeks to compute the optimal shape and topology of a structure such that one or more properties, for example stiffness, balance or volume, are improved. The goal of the thesis is to develop a method for shape and topology optimization which uses the Deformable...... Simplicial Complex (DSC) method. Consequently, we present a novel method which combines current shape and topology optimization methods. This method represents the surface of the structure explicitly and discretizes the structure into non-overlapping elements, i.e. a simplicial complex. An explicit surface...... representation usually limits the optimization to minor shape changes. However, the DSC method uses a single explicit representation and still allows for large shape and topology changes. It does so by constantly applying a set of mesh operations during deformations of the structure. Using an explicit instead...

  15. The power of collective ambition.

    Science.gov (United States)

    Ready, Douglas A; Truelove, Emily

    2011-12-01

    In the past few years, some companies have not just weathered the economic storm: They've emerged stronger than ever. How did such players as Four Seasons, Sephora, and Standard Chartered Bank defy conventional logic? Instead of pursuing a single ambition, such as profits, employees defined a collective ambition. As a result, those organizations deepened their engagement with employees and other stakeholders and became sustainably profitable. Purpose, a company's reason for existence, is the central element of collective ambition. The other elements--vision, targets and milestones, strategic and operational priorities, brand promise, core values, and leader behaviors--must be aligned to serve the company's purpose. Articulating the elements of collective ambition can give everyone in the organization a better sense of the company's purpose and how they can contribute to it. Purpose does not have to be about saving the world; providing excellent entertainment or banking services is just as meaningful a purpose as improving health care in emerging economies--as long as it is an authentic representation of why the company exists. To shape and then achieve a collective ambition, companies must strengthen their organizational glue (the collaborative engagement that creates a unified culture) and grease (the disciplined execution that enterprisewide change initiatives require).

  16. Archaeal extrachromosomal genetic elements

    DEFF Research Database (Denmark)

    Wang, Haina; Peng, Nan; Shah, Shiraz Ali

    2015-01-01

    SUMMARY: Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes, such as spind......SUMMARY: Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes...

  17. Shape recovery and irrecoverable strain control in polyurethane shape-memory polymer

    International Nuclear Information System (INIS)

    Tobushi, Hisaaki; Ejiri, Yoshihiro; Hayashi, Syunichi; Hoshio, Kazumasa

    2008-01-01

    In shape-memory polymers, large strain can be fixed at a low temperature and thereafter recovered at a high temperature. If the shape-memory polymer is held at a high temperature for a long time, the irrecoverable strain can attain a new intermediate shape between the shape under the maximum stress and the primary shape. Irrecoverable strain control can be applied to the fabrication of a shape-memory polymer element with a complex shape in a simple method. In the present study, the influence of the strain-holding conditions on the shape recovery and the irrecoverable strain control in polyurethane shape-memory polymer is investigated by tension test of a film and three-point bending test of a sheet. The higher the shape-holding temperature and the longer the shape-holding time, the higher the irrecoverable strain rate. The equation that expresses the characteristics of the irrecoverable strain control is formulated

  18. Shape recovery and irrecoverable strain control in polyurethane shape-memory polymer

    Directory of Open Access Journals (Sweden)

    Hisaaki Tobushi et al

    2008-01-01

    Full Text Available In shape-memory polymers, large strain can be fixed at a low temperature and thereafter recovered at a high temperature. If the shape-memory polymer is held at a high temperature for a long time, the irrecoverable strain can attain a new intermediate shape between the shape under the maximum stress and the primary shape. Irrecoverable strain control can be applied to the fabrication of a shape-memory polymer element with a complex shape in a simple method. In the present study, the influence of the strain-holding conditions on the shape recovery and the irrecoverable strain control in polyurethane shape-memory polymer is investigated by tension test of a film and three-point bending test of a sheet. The higher the shape-holding temperature and the longer the shape-holding time, the higher the irrecoverable strain rate. The equation that expresses the characteristics of the irrecoverable strain control is formulated.

  19. Shaping light

    CSIR Research Space (South Africa)

    Forbes, A

    2010-01-01

    Full Text Available . The nucleus of an atom is a mixture of positively charged protons and electrically neutral neutrons. The electrons of an atom are bound to the nucleus by the electromagnetic force that is generated by the electrical charges they carry. More than 99.... The number of protons in a nucleus is the atomic number and this defines the type of element (pure chemical substance) that the atom forms. A neutron is a sub-atomic particle with no electrical charge. Its mass is slightly larger than that of a proton...

  20. Shape Synthesis in Mechanical Design

    Directory of Open Access Journals (Sweden)

    C. P. Teng

    2007-01-01

    Full Text Available The shaping of structural elements in the area of mechanical design is a recurrent problem. The mechanical designer, as a rule, chooses what is believed to be the “simplest” shapes, such as the geometric primitives: lines, circles and, occasionally, conics. The use of higher-order curves is usually not even considered, not to speak of other curves than polynomials. However, the simplest geometric shapes are not necessarily the most suitable when the designed element must withstand loads that can lead to failure-prone stress concentrations. Indeed, as mechanical designers have known for a while, stress concentrations occur, first and foremost, by virtue of either dramatic changes in curvature or extremely high values thereof. As an alternative, we propose here the use of smooth curves that can be simply generated using standard concepts such as non-parametric cubic splines. These curves can be readily used to produce either extruded surfaces or surfaces of revolution. 

  1. Z-dependence and collective analysis of M x-ray production cross sections for a wide range of elements (60≤Z≤90) by proton impact

    International Nuclear Information System (INIS)

    Deghfel, B.; Kahoul, A.; Kerai, S.; Saadaoui, M.; Dechoucha, S.; Nekkab, M.

    2013-01-01

    Based on the remarkable spread of the ratios of the experimental to theoretical M-shell x-ray production cross section, where they are usually analyzed by a function depending only on the scaled velocity parameter, we attempt to deduce new semi-empirical cross sections by introducing the dependence of these ratios on the atomic number of the target, noted as “Z-dependence”. For this effect, the ECPSSR model and the updated experimental data (from 1980 till 2009) of the M-shell x-ray production cross sections are combined to calculate the semi-empirical cross sections for a wide range of heavy elements (60≤Z≤90) by proton impact. A brief discussion of the agreement between our results and earlier theoretical as well as experimental works has been demonstrated. - Highlights: • Theoretical M x-ray production cross sections have been calculated within the ECPSSR model. • Updated database contains about 658 values for elements with 60≤Z≤90 by proton impact. • A new procedure, noted as “Z-dependence”, is followed to deduce semi-empirical cross section. • The obtained results are compared with others theoretical and experimental works. • Z-dependence cross sections are in good agreement with the experiment over the whole energy range

  2. [Analysis of 27 mineral elements in the rice samples collected from China and Japan by using ICP-OES and ICP-MS].

    Science.gov (United States)

    Wang, Xiao-ping; Li, Bai

    2010-08-01

    Based on microwave-assisted decomposition and dry ashing methods, the concentrations of Al, As, B, Ba, Ca, Cd, Co, Cr, Cs, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Se, Sr, T1, V and Zn in sixteen Chinese rice samples and eleven Japanese rice samples were analysed by using ICP-OES and ICP-MS, and a biological standard reference material rice (GBW10010) was used to verify the accuracy and the precision of analytical method. It was demonstrated that ICP-MS equipped with a collision cell technique can be successfully used for reducing polyatomic interferences in the detection of elements with low m/z ratios. Compared with those in Japanese rice samples, the concentrations of Al, S and Sr in Chinese rice samples are significantly high, and the concentrations of B, Cd, Cs, Mg, Mo, P, Pb and Zn in Chinese rice samples are much lower (P < 0.05). The Ward's method of cluster analysis applied to the concentrations of 26 elements except T1 whose concentration is below the detection limit exhibited the ability to effectively differentiate Chinese rice samples from Japanese rice samples. Moreover, it was found that the concentrations of magnesium correlate very well with the concentrations of phosphorus in all rice samples, with the correlation coefficient being as high as 0.9552.

  3. General quadrupole nuclear shapes. An algebraic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A. (Los Alamos National Lab. (LANL), NM (USA). Theoretical Div.); Shao Bin (Yale Univ., New Haven, CT (USA). Sloane Physics Lab.)

    1990-07-05

    Spherical, axial and non-axial quadrupole shapes are investigated within the algebraic interacting boson model. For each shape the hamiltonian is resolved into intrinsic and collective parts, normal modes are identified and intrinsic states are constructed. Special emphasis is paid to new features (e.g. rigid triaxiality and coexisting deformed shapes) that emerge in the presence of three-body interactions. (orig.).

  4. General quadrupole nuclear shapes. An algebraic perspective

    International Nuclear Information System (INIS)

    Leviatan, A.; Shao Bin

    1990-01-01

    Spherical, axial and non-axial quadrupole shapes are investigated within the algebraic interacting boson model. For each shape the hamiltonian is resolved into intrinsic and collective parts, normal modes are identified and intrinsic states are constructed. Special emphasis is paid to new features (e.g. rigid triaxiality and coexisting deformed shapes) that emerge in the presence of three-body interactions. (orig.)

  5. Investigation of interfacial shear stresses, shape fixity, and actuation strain in composites incorporating shape memory polymers and shape memory alloys

    Science.gov (United States)

    Park, Jungkyu; Headings, Leon; Dapino, Marcelo; Baur, Jeffery; Tandon, Gyaneshwar

    2015-03-01

    Shape memory composites (SMCs) based on shape memory alloys (SMAs) and shape memory polymers (SMPs) allow many design possibilities due to their controllable temperature-dependent mechanical properties. The complementary characteristics of SMAs and SMPs can be utilized in systems with shape recovery created by the SMA and shape fixity provided by the SMP. In this research, three SMC operating regimes are identified and the behavior of SMC structures is analyzed by focusing on composite shape fixity and interfacial stresses. Analytical models show that SMPs can be used to adequately fix the shape of SMA actuators and springs. COMSOL finite element simulations are in agreement with analytical expressions for shape fixity and interfacial stresses. Analytical models are developed for an end-coupled linear SMP-SMA two-way actuator and the predicted strain is shown to be in good agreement with experimental test results.

  6. Comparison of trace element content in marine organisms collected from the La Maddalena archipelago and other Mediterranean and Pacific ocean sites

    International Nuclear Information System (INIS)

    Boniforti, R.; Moauro, A.

    1982-01-01

    As, Sb, Zn, Hg, Fe, Co and Cs were analysed by instrumental neutron activation analysis in four fish species (Mullus surmuletus, Scorpaena porcus, Crenilabus cinereus, and Serranus scriba) and one gesteropod (Sepia officinalis). The results were compared with those obtained by other authors for fish collected both in the Mediterranean and the Pacific. The difficulty of comparing results obtained by different authors was stressed and some suggestions to overcome this difficulty were given

  7. Z-dependence and collective analysis of M x-ray production cross sections for a wide range of elements (60≤Z≤90) by proton impact

    Science.gov (United States)

    Deghfel, B.; Kahoul, A.; Kerai, S.; Saadaoui, M.; Dechoucha, S.; Nekkab, M.

    2013-11-01

    Based on the remarkable spread of the ratios of the experimental to theoretical M-shell x-ray production cross section, where they are usually analyzed by a function depending only on the scaled velocity parameter, we attempt to deduce new semi-empirical cross sections by introducing the dependence of these ratios on the atomic number of the target, noted as "Z-dependence". For this effect, the ECPSSR model and the updated experimental data (from 1980 till 2009) of the M-shell x-ray production cross sections are combined to calculate the semi-empirical cross sections for a wide range of heavy elements (60≤Z≤90) by proton impact. A brief discussion of the agreement between our results and earlier theoretical as well as experimental works has been demonstrated.

  8. Micro-PIXE analysis of trace element variation in otoliths from fish collected near acid mine tailings: Potential for monitoring contaminant dispersal

    International Nuclear Information System (INIS)

    Saquet, M.; Halden, N.M.; Babaluk, J.; Campbell, J.L.; Nejedly, Z.

    2002-01-01

    Otoliths from fish sampled proximal to acid mine tailings located near Sherridon, Manitoba contain elevated abundances of Zn, Mn, Fe and Cu. Sr is also present in amounts ranging from 250 to 1200 ppm with the actual levels dependent on the lake from which fish were taken. Previous work on analyzing Zn and Mn suggests Zn will typically vary between 50 and ∼100 ppm (in marine and non-marine species) and Mn between 10 and ∼100 ppm. Otoliths analyzed in this study contain up to ∼1000 ppm Zn and up to ∼400 ppm Mn; Fe is present, ranging between 50 and 100 ppm and Cu is typically 40-50 ppm. Water samples showed variation in these elements depending on proximity to the tailings

  9. ESR powder line shape calculations

    Energy Technology Data Exchange (ETDEWEB)

    Vitko, J. Jr.; Huddleston, R.E.

    1976-05-01

    A program has been developed for computing the ESR spectrum of a collection of randomly oriented spins subject only to an electronic Zeeman interaction and having a Lorentzian single crystal line shape. Other single crystal line shapes, including numerical solutions of the Bloch equations, can be accommodated with minor modifications. The program differs in several features from those existing elsewhere, thus enabling one to study saturation effects, over-modulation effects, both absorptive and dispersive signals, and second and higher order derivative signals.

  10. 2. Transuranic elements

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Methods of sample collection, sample storage, sample procedures and radioanalytical procedures for transuranic elements in marine environment are reviewed and recommended. Alpha spectrometry and scintillation techniques are used for measurement of isotopic content. Separation processes for samples are described

  11. Linear shaped charge

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, David; Stofleth, Jerome H.; Saul, Venner W.

    2017-07-11

    Linear shaped charges are described herein. In a general embodiment, the linear shaped charge has an explosive with an elongated arrowhead-shaped profile. The linear shaped charge also has and an elongated v-shaped liner that is inset into a recess of the explosive. Another linear shaped charge includes an explosive that is shaped as a star-shaped prism. Liners are inset into crevices of the explosive, where the explosive acts as a tamper.

  12. Nanoreinforced shape memory polyurethane

    Science.gov (United States)

    Richardson, Tara Beth

    Shape memory polymers (SMPs) are functional materials, which find applications in a broad range of temperature sensing elements and biological micro-electro-mechanical systems (MEMS). These polymers are capable of fixing a transient shape and recovering to their original shape after a series of thermo-mechanical treatments. Generally, these materials are thermoplastic segmented polyurethanes composed of soft segments, usually formed by a polyether macroglycol, and hard segments formed from the reaction of a diisocyanate with a low molecular mass diol. The hard segment content is a key parameter to control the final properties of the polymer, such as rubbery plateau modulus, melting point, hardness, and tensile strength. The long flexible soft segment largely controls the low temperature properties, solvent resistance, and weather resistance properties. The morphology and properties of polyurethanes (PU) are greatly influenced by the ratio of hard and soft block components and the average block lengths. However, in some applications, SMPs may not generate enough recovery force to be useful. The reinforcement of SMPs using nanofillers represents a novel approach of enhancing the performance of these materials. The incorporation of these fillers into SMPs can produce performance enhancements (particularly elastic modulus) at small nanoparticle loadings (˜1-2 wt %). An optimal performance of nanofiller-polymer nanocomposites requires uniform dispersion of filler in polymers and good interfacial adhesion. The addition of nanofillers like cellulose nanofibers (CNF), conductive cellulose nanofibers (C-CNF), and carbon nanotubes (CNTs) allows for the production of stiffer materials with deformation capacity comparable to that of the unfilled polymer. Additionally, the use of conductive nanoreinforcements such as C-CNF and CNTs leads to new pathways for actuation of the shape memory effect. During this work, thermoplastic shape memory polyurethanes were synthesized with

  13. Thermoviscoelastic shape memory behavior for epoxy-shape memory polymer

    International Nuclear Information System (INIS)

    Chen, Jianguo; Liu, Liwu; Liu, Yanju; Leng, Jinsong

    2014-01-01

    There are various applications for shape memory polymer (SMP) in the smart materials and structures field due to its large recoverable strain and controllable driving method. The mechanical shape memory deformation mechanism is so obscure that many samples and test schemes have to be tried in order to verify a final design proposal for a smart structure system. This paper proposes a simple and very useful method to unambiguously analyze the thermoviscoelastic shape memory behavior of SMP smart structures. First, experiments under different temperature and loading conditions are performed to characterize the large deformation and thermoviscoelastic behavior of epoxy-SMP. Then, a rheological constitutive model, which is composed of a revised standard linear solid (SLS) element and a thermal expansion element, is proposed for epoxy-SMP. The thermomechanical coupling effect and nonlinear viscous flowing rules are considered in the model. Then, the model is used to predict the measured rubbery and time-dependent response of the material, and different thermomechanical loading histories are adopted to verify the shape memory behavior of the model. The results of the calculation agree with experiments satisfactorily. The proposed shape memory model is practical for the design of SMP smart structures. (paper)

  14. The occurrence of trace elements in bed sediment collected from areas of varying land use and potential effects on stream macroinvertebrates in the conterminous western United States, Alaska, and Hawaii, 1992-2000

    Science.gov (United States)

    Paul, Angela P.; Paretti, Nicholas V.; MacCoy, Dorene E.; Brasher, Anne M.D.

    2012-01-01

    As part of the National Water-Quality Assessment Program of the U.S. Geological Survey, this study examines the occurrence of nine trace elements in bed sediment of varying mineralogy and land use and assesses the possible effects of these trace elements on aquatic-macroinvertebrate community structure. Samples of bed sediment and macroinvertebrates were collected from 154 streams at sites representative of undeveloped, agricultural, urban, mined, or mixed land-use areas and 12 intermediate-scale ecoregions within the conterminous western United States, Alaska, and Hawaii from 1992 to 2000. The nine trace elements evaluated during this study—arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn)—were selected on the basis of potential ecologic significance and availability of sediment-quality guidelines. At most sites, the occurrence of these trace elements in bed sediment was at concentrations consistent with natural geochemical abundance, and the lowest concentrations were in bed-sediment samples collected from streams in undeveloped and agricultural areas. With the exception of Zn at sampling sites influenced by historic mining-related activities, median concentrations of all nine trace elements in bed sediment collected from sites representative of the five general land-use areas were below concentrations predicted to be harmful to aquatic macroinvertebrates. The highest concentrations of As, Cd, Pb, and Zn were in bed sediment collected from mined areas. Median concentrations of Cu and Ni in bed sediment were similarly enriched in areas of mining, urban, and mixed land use. Concentrations of Cr and Ni appear to originate largely from geologic sources, especially in the western coastal states (California, Oregon, and Washington), Alaska, and Hawaii. In these areas, naturally high concentrations of Cr and Ni can exceed concentrations that may adversely affect aquatic macroinvertebrates

  15. Heavy element radionuclides (Pu, Np, U) and 137Cs in soils collected from the Idaho National Engineering and Environmental Laboratory and other sites in Idaho, Montana, and Wyoming

    International Nuclear Information System (INIS)

    Beasley, T.M.; Rivera, W. Jr.; Liszewski, M.J.; Orlandini, K.A.

    1998-10-01

    The isotopic composition of Pu in soils on and near the Idaho National Engineering and Environmental Laboratory (INEEL) has been determined in order to apportion the sources of the Pu into those derived from stratospheric fallout, regional fallout from the Nevada Test Site (NTS), and facilities on the INEEL site. Soils collected offsite in Idaho, Montana, and Wyoming were collected to further characterize NTS fallout in the region. In addition, measurements of 237 Np and 137 Cs were used to further identify the source of the Pu from airborne emissions at the Idaho Chemical Processing Plant (ICPP) or fugitive releases from the Subsurface Disposal Area (SDA) in the Radioactive Waste Management Complex (RWMC). There is convincing evidence from this study that 241 Am, in excess of that expected from weapons-grade Pu, constituted a part of the buried waste at the SDA that has subsequently been released to the environment. Measurements of 236 U in waters from the Snake River Plain aquifer and a soil core near the ICPP suggest that this radionuclide may be a unique interrogator of airborne releases from the ICPP. Neptunium-237 and 238 Pu activities in INEEL soils suggest that airborne releases of Pu from the ICPP, over its operating history, may have recently been overestimated

  16. Shape language - How people describe shapes and shape operations

    NARCIS (Netherlands)

    Wiegers, T.; Langeveld, L.H.; Vergeest, J.S.M.

    2001-01-01

    Many designers do not use CAD tools for shape ideation. They consider CAD systems not appropriate for the ideation phase. This research investigates how designers ideate shape, in particular which terms they use to exteriorize shape. The goal is to be able to propose digital tools that are useful

  17. Instance-Based Generative Biological Shape Modeling.

    Science.gov (United States)

    Peng, Tao; Wang, Wei; Rohde, Gustavo K; Murphy, Robert F

    2009-01-01

    Biological shape modeling is an essential task that is required for systems biology efforts to simulate complex cell behaviors. Statistical learning methods have been used to build generative shape models based on reconstructive shape parameters extracted from microscope image collections. However, such parametric modeling approaches are usually limited to simple shapes and easily-modeled parameter distributions. Moreover, to maximize the reconstruction accuracy, significant effort is required to design models for specific datasets or patterns. We have therefore developed an instance-based approach to model biological shapes within a shape space built upon diffeomorphic measurement. We also designed a recursive interpolation algorithm to probabilistically synthesize new shape instances using the shape space model and the original instances. The method is quite generalizable and therefore can be applied to most nuclear, cell and protein object shapes, in both 2D and 3D.

  18. Locals Collection

    Directory of Open Access Journals (Sweden)

    Stephen Hastings-King

    2010-03-01

    Full Text Available A locals collection is a set of parameters that are used to delimit data-mining operations. This piece uses a collection of locals from around Essex Massachusetts to shape and delimit an interrogation of post-reality in contemporary America. It explores the notion of crisis, the possibility of a crisis of empire that may or may not emerge in a media-space that does not allow crisis of empire to be mentioned and relations this maybe-crisis to the various levels of economic dysfunction that have become evident since late 2008. But mostly this piece explores ways in which particular stories about particular people do and do not link/link to these larger-scale narratives. This is the first of a potential series of locals collections that will mine the American post-real.

  19. Audiometric shape and presbycusis.

    Science.gov (United States)

    Demeester, Kelly; van Wieringen, Astrid; Hendrickx, Jan-jaap; Topsakal, Vedat; Fransen, Erik; van Laer, Lut; Van Camp, Guy; Van de Heyning, Paul

    2009-04-01

    The aim of this study was to describe the prevalence of specific audiogram configurations in a healthy, otologically screened population between 55 and 65 years old. The audiograms of 1147 subjects (549 males and 598 females between 55 and 65 years old) were collected through population registries and classified according to the configuration of hearing loss. Gender and noise/solvent-exposure effects on the prevalence of the different audiogram shapes were determined statistically. In our population 'Flat' audiograms were most dominantly represented (37%) followed by 'High frequency Gently sloping' audiograms (35%) and 'High frequency Steeply sloping' audiograms (27%). 'Low frequency Ascending' audiograms, 'Mid frequency U-shape' audiograms and 'Mid frequency Reverse U-shape' audiograms were very rare (together less than 1%). The 'Flat'-configuration was significantly more common in females, whereas the 'High frequency Steeply sloping'-configuration was more common in males. Exposure to noise and/or solvents did not change this finding. In addition, females with a 'Flat' audiogram had a significantly larger amount of overall hearing loss compared to males. Furthermore, our data reveal a significant association between the prevalence of 'High frequency Steeply sloping' audiograms and the degree of noise/solvent exposure, despite a relatively high proportion of non-exposed subjects showing a 'High frequency Steeply sloping' audiogram as well.

  20. An X-ray fluorescence method for the determination of small quantities el elements collected on filters; Determinacion de pequenas concentraciones de elementos en filtros por espectrometria de fluorescencia de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guerra, J. P.; Bayon, A.

    1981-07-01

    An X-ray fluorescence method for the determination of As, Ba, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, U, V and Zn collected on P.V.C. filters in concentration ranges from 0,6 to 1000{mu}g, depending on the element, is described. A sequential automatic spectrometer with a chromium tube is used for tho Ba determination, while As, Hg, Pb, Se and U are bottler determined with a molybdenum one. For the rest of the elements a tungsten target is preferred. The interferences between AsK{sup {alpha}}{sub 1},2- PbL{sup {alpha}}{sub 1},2 and CrK{sup {alpha}}{sub 1},2-Vk{beta}{sub 1},3 lines are corrected by applying specific coefficients. The radial variation of the primary X-ray beam intensity on the irradiated surface has been specially studied with chromium, gold, molybdenum and tungsten tubes. For that purpose different x-ray wavelengths in the range 9,89 A to 0,56 A have been selected. The curves obtained show a rather high heterogeneity for the excitation source. This conclusion implies the need for an homogeneous distribution of elements on the filter. (Author) 7 refs.

  1. Concentrations of alkali and alkaline earth elements in mushrooms and plants collected in a Japanese pine forest, and their relationship with 137Cs

    International Nuclear Information System (INIS)

    Yoshida, S.; Muramatsu, Y.

    1998-01-01

    137 Cs and stable Na, K, Rb, Cs, Mg, Ca, Sr, Ba and Al were determined in 29 mushrooms and 8 plants collected from a Japanese pine forest. Concentrations of 137 Cs, Cs and Rb in mushrooms were one order of magnitude higher than those in plants growing in the same forest. On the other hand, concentrations of Ca and Sr in mushrooms were obviously lower than those in plants. A good correlation (r=0·99, p 137 Cs and stable Cs concentrations was observed for mushrooms. The 137 Cs/Cs ratios were almost constant ( 137 Cs/Cs=134±36 Bq mg -1 in 1990) and were significantly higher than that in the surface soil (27 Bq mg -1 ). The ratios for plants were almost the same as those for mushrooms. In plant samples, good correlations were observed among the concentrations of K, Rb, Cs and Mg. Correlation between those of Ca and Sr was also good. In contrast, Cs was not correlated with K in mushrooms, indicating that the mechanism of Cs uptake was different from that for K. Rb showed a correlation with Cs (r=0·82). (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  2. Concentrations of alkali and alkaline earth elements in mushrooms and plants collected in a Japanese pine forest, and their relationship with 137Cs

    International Nuclear Information System (INIS)

    Yoshida, S.; Muramatsu, Y.

    1998-01-01

    137 Cs and stable Na, K, Rb, Cs, Mg, Ca, Sr, Ba and Al were determined in 29 mushrooms and 8 plants collected from a Japanese pine forest. Concentrations of 137 Cs, Cs and Rb in mushrooms were one order of magnitude higher than those in plants growing in the same forest. On the other hand, concentrations of Ca and Sr in mushrooms were obviously lower than those in plants. A good correlation (r=0·99,p 137 Cs and stable Cs concentrations was observed for mushrooms. The 137 Cs/Cs ratios were almost constant ( 137 Cs/Cs=134±36 Bq mg -1 in 1990) and were significantly higher than that in the surface soil (27 Bq mg -1 ). The ratios for plants were almost the same as those for mushrooms. In plant samples, good correlations were observed among the concentrations of K, Rb, Cs and Mg. Correlation between those of Ca and Sr was also good. In contrast, Cs was not correlated with K in mushrooms, indicating that the mechanism of Cs uptake was different from that for K. Rb showed a correlation with Cs (r=0·82)

  3. Deformation Based Curved Shape Representation.

    Science.gov (United States)

    Demisse, Girum G; Aouada, Djamila; Ottersten, Bjorn

    2017-06-02

    In this paper, we introduce a deformation based representation space for curved shapes in Rn. Given an ordered set of points sampled from a curved shape, the proposed method represents the set as an element of a finite dimensional matrix Lie group. Variation due to scale and location are filtered in a preprocessing stage, while shapes that vary only in rotation are identified by an equivalence relationship. The use of a finite dimensional matrix Lie group leads to a similarity metric with an explicit geodesic solution. Subsequently, we discuss some of the properties of the metric and its relationship with a deformation by least action. Furthermore, invariance to reparametrization or estimation of point correspondence between shapes is formulated as an estimation of sampling function. Thereafter, two possible approaches are presented to solve the point correspondence estimation problem. Finally, we propose an adaptation of k-means clustering for shape analysis in the proposed representation space. Experimental results show that the proposed representation is robust to uninformative cues, e.g. local shape perturbation and displacement. In comparison to state of the art methods, it achieves a high precision on the Swedish and the Flavia leaf datasets and a comparable result on MPEG-7, Kimia99 and Kimia216 datasets.

  4. Elemental matrices for the finite element method in electromagnetics with quadratic triangular elements

    OpenAIRE

    Cojocaru, E.

    2009-01-01

    The finite element method has become a preeminent simulation technique in electromagnetics. For problems involving anisotropic media and metamaterials, proper algorithms should be developed. It has been proved that discretizing in quadratic triangular elements may lead to an improved accuracy. Here we present a collection of elemental matrices evaluated analytically for quadratic triangular elements. They could be useful for the finite element method in advanced electromagnetics.

  5. Toxic Elements

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Shakibazadeh, Shahram; Sloth, Jens Jørgen

    2016-01-01

    Food is considered the main source of toxic element (arsenic, cadmium, lead, and mercury) exposure to humans, and they can cause major public health effects. In this chapter, we discuss the most important sources for toxic element in food and the foodstuffs which are significant contributors...... to human exposure. The occurrence of each element in food classes from different regions is presented. Some of the current toxicological risk assessments on toxic elements, the human health effect of each toxic element, and their contents in the food legislations are presented. An overview of analytical...... techniques and challenges for determination of toxic elements in food is also given....

  6. Numerical Inversion of SRNF Maps for Elastic Shape Analysis of Genus-Zero Surfaces.

    Science.gov (United States)

    Laga, Hamid; Xie, Qian; Jermyn, Ian H; Srivastava, Anuj

    2017-12-01

    Recent developments in elastic shape analysis (ESA) are motivated by the fact that it provides a comprehensive framework for simultaneous registration, deformation, and comparison of shapes. These methods achieve computational efficiency using certain square-root representations that transform invariant elastic metrics into euclidean metrics, allowing for the application of standard algorithms and statistical tools. For analyzing shapes of embeddings of in , Jermyn et al. [1] introduced square-root normal fields (SRNFs), which transform an elastic metric, with desirable invariant properties, into the metric. These SRNFs are essentially surface normals scaled by square-roots of infinitesimal area elements. A critical need in shape analysis is a method for inverting solutions (deformations, averages, modes of variations, etc.) computed in SRNF space, back to the original surface space for visualizations and inferences. Due to the lack of theory for understanding SRNF maps and their inverses, we take a numerical approach, and derive an efficient multiresolution algorithm, based on solving an optimization problem in the surface space, that estimates surfaces corresponding to given SRNFs. This solution is found to be effective even for complex shapes that undergo significant deformations including bending and stretching, e.g., human bodies and animals. We use this inversion for computing elastic shape deformations, transferring deformations, summarizing shapes, and for finding modes of variability in a given collection, while simultaneously registering the surfaces. We demonstrate the proposed algorithms using a statistical analysis of human body shapes, classification of generic surfaces, and analysis of brain structures.

  7. Shape-morphing nanocomposite origami.

    Science.gov (United States)

    Andres, Christine M; Zhu, Jian; Shyu, Terry; Flynn, Connor; Kotov, Nicholas A

    2014-05-20

    Nature provides a vast array of solid materials that repeatedly and reversibly transform in shape in response to environmental variations. This property is essential, for example, for new energy-saving technologies, efficient collection of solar radiation, and thermal management. Here we report a similar shape-morphing mechanism using differential swelling of hydrophilic polyelectrolyte multilayer inkjets deposited on an LBL carbon nanotube (CNT) composite. The out-of-plane deflection can be precisely controlled, as predicted by theoretical analysis. We also demonstrate a controlled and stimuli-responsive twisting motion on a spiral-shaped LBL nanocomposite. By mimicking the motions achieved in nature, this method offers new opportunities for the design and fabrication of functional stimuli-responsive shape-morphing nanoscale and microscale structures for a variety of applications.

  8. What shapes social decision making?

    Science.gov (United States)

    Reader, Simon M; Leris, Ioannis

    2014-02-01

    Outcome transparency and the weight given to social information both play important roles in decision making, but we argue that an overarching influence is the degree to which individuals can and do gather information. Evolution, experience, and development may shape individual specializations in social decision making that carry over across contexts, and these individual differences may influence collective behavior and cultural evolution.

  9. Collective drawing

    Directory of Open Access Journals (Sweden)

    Roberto Grossa

    2009-10-01

    Full Text Available This paper is referred to the experiences run at Iuav in the framework of the EU-FSE founded Courses of Collaborative Composition. In these courses we built up some work/game thought as meaning of a distance collaborative game. Rally around these games, we delivered specific knowledge and portions of technical knowledge referred to the issue of formal structure, shape grammar, and codify of “behaviours role” for a networked distance collaboration. The subject of this didactic experience is the composition and of a collective figurative opera (an image processed by the whole group of students. The themes of the image have been different in each Course: a figurative opera, a facade of an urban street or a small square. The students shared a repertory of figures coming from the break down of paintings or pictures of palaces and used the repertory as a source in order to compose the final collective opera. On the other side we worked on the shape grammar roles, experimented tools and protocols of communication, analysed the best practice in this field and defined evaluation systems.

  10. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Butterfield, C.E.; Waite, E.

    1982-01-01

    A nuclear reactor fuel element comprising a column of vibration compacted fuel which is retained in consolidated condition by a thimble shaped plug. The plug is wedged into gripping engagement with the wall of the sheath by a wedge. The wedge material has a lower coefficient of expansion than the sheath material so that at reactor operating temperature the retainer can relax sufficient to accommodate thermal expansion of the column of fuel. (author)

  11. Elemental Composition of Suspended Particulate Matter Collected ...

    African Journals Online (AJOL)

    High enrichment factors were observed for Cu (10.8 - 228.3), Zn (12.4 - 124.6), Pb (59.4 - 1967) and Br (152.5 - 3038.7) at both heights suggesting anthropogenic activities such as industrial, urban refuse burning, residential and vehicular emissions could be the major contributors. Pb and Br were mainly from the vehicular ...

  12. Power throttling of collections of computing elements

    Science.gov (United States)

    Bellofatto, Ralph E [Ridgefield, CT; Coteus, Paul W [Yorktown Heights, NY; Crumley, Paul G [Yorktown Heights, NY; Gara, Alan G [Mount Kidsco, NY; Giampapa, Mark E [Irvington, NY; Gooding,; Thomas, M [Rochester, MN; Haring, Rudolf A [Cortlandt Manor, NY; Megerian, Mark G [Rochester, MN; Ohmacht, Martin [Yorktown Heights, NY; Reed, Don D [Mantorville, MN; Swetz, Richard A [Mahopac, NY; Takken, Todd [Brewster, NY

    2011-08-16

    An apparatus and method for controlling power usage in a computer includes a plurality of computers communicating with a local control device, and a power source supplying power to the local control device and the computer. A plurality of sensors communicate with the computer for ascertaining power usage of the computer, and a system control device communicates with the computer for controlling power usage of the computer.

  13. Shape memory polymers

    Science.gov (United States)

    Wilson, Thomas S.; Bearinger, Jane P.

    2015-06-09

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxyl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  14. Concentrations of Platinum Group Elements (Pt, Pd, Rh in Airborne Particulate Matter (PM2.5 and PM10-2.5 Collected at Selected Canadian Urban Sites: a Case Study

    Directory of Open Access Journals (Sweden)

    Celo V.

    2013-04-01

    Full Text Available Increasing environmental concentrations of platinum group elements (PGEs, in particular platinum (Pt, palladium (Pd and rhodium (Rh, from catalytic converters has been reported worldwide. Initially it was believed that the emitted PGEs remain in the roadside environment, but recent studies have shown that fine PGE-containing particles can be transported and distributed at regional and long-range levels. Therefore, the monitoring of PGEs in airborne particulate matter (PM is important for the estimation of potential risks to human health and to the ecosystem. The aim of this study is to present the first results from an analysis on the concentration and distribution of Pt, Pd and Rh in PM collected on Teflon filters at two selected urban sites (Toronto, Ontario; Edmonton, Alberta collected within the Canadian National Air Pollution Surveillance (NAPS network. In this work, a quadruple inductively coupled plasma mass spectrometry (ICP-MS, combined with microwave assisted acid digestion using aqua regia was used. A cation exchange separation was used to alleviate the matrix-induced spectral and nonspectral interferences prior to ICP-MS analysis. To obtain sufficient material needed for PGEs analysis, fine PM (particles with aerodynamic diameter less than 2.5 mm; PM2.5 and coarse PM (with aerodynamic diameter between 2.5 and 10 mm; PM10-2.5 samples were combined into composite samples on a seasonal basis. The obtained results will be discussed and compared with literature data.

  15. Quantitative determination of selenium and mercury, and an ICP-MS semi-quantitative scan of other elements in samples of eagle tissues collected from the Pacific Northwest--Summer 2011

    Science.gov (United States)

    May, Thomas; Walther, Mike; Brumbaugh, William

    2013-01-01

    Eagle tissues from dead eagle carcasses were collected by U.S. Fish and Wildlife Service personnel at various locations in the Pacific Northwest as part of a study to document the occurrence of metal and metalloid contaminants. A group of 182 eagle tissue samples, consisting of liver, kidney, brain, talon, feather, femur, humerus, and stomach contents, were quantitatively analyzed for concentrations of selenium and mercury by atomic absorption techniques, and for other elements by semi-quantitative scan with an inductively coupled plasma-mass spectrometer. For the various tissue matrices analyzed by an ICP-MS semiquantitative scan, some elemental concentrations (micrograms per gram dry weight) were quite variable within a particular matrix; notable observations were as follows: lead concentrations ranged from 0.2 to 31 in femurs, 0.1 to 29 in humeri, 0.1 to 54 in talons, less than (<) 0.05 to 120 in livers, <0.05 to 34 in kidneys, and 0.05 to 8 in brains; copper concentrations ranged from 5 to 9 in feathers, 8 to 47 in livers, 7 to 43 in kidneys, and 7 to 28 in brains; cadmium concentrations ranged from 0.1 to 10 in kidneys. In stomach contents, concentrations of vanadium ranged from 0.08 to 5, chromium 2 to 34, manganese 1 to 57, copper 2 to 69, arsenic <0.05 to 6, rubidium 1 to 13, and barium <0.5 to 18. Selenium concentrations from highest to lowest based on the matrix mean were as follows: kidney, liver, feather, brain, stomach content, talon, femur, and humerus. For mercury, the highest to lowest concentrations were feather, liver, talon, brain, stomach content, femur, and humerus.

  16. Shape-changing interfaces:

    DEFF Research Database (Denmark)

    Rasmussen, Majken Kirkegård; Pedersen, Esben Warming; Petersen, Marianne Graves

    2015-01-01

    Shape change is increasingly used in physical user interfaces, both as input and output. Yet, the progress made and the key research questions for shape-changing interfaces are rarely analyzed systematically. We review a sample of existing work on shape-changing interfaces to address these shortc......Shape change is increasingly used in physical user interfaces, both as input and output. Yet, the progress made and the key research questions for shape-changing interfaces are rarely analyzed systematically. We review a sample of existing work on shape-changing interfaces to address...... shape-changing interfaces be used for, (b) which parts of the design space are not well understood, and (c) why studying user experience with shape-changing interfaces is important....

  17. Self-erecting shapes

    Science.gov (United States)

    Reading, Matthew W.

    2017-07-04

    Technologies for making self-erecting structures are described herein. An exemplary self-erecting structure comprises a plurality of shape-memory members that connect two or more hub components. When forces are applied to the self-erecting structure, the shape-memory members can deform, and when the forces are removed the shape-memory members can return to their original pre-deformation shape, allowing the self-erecting structure to return to its own original shape under its own power. A shape of the self-erecting structure depends on a spatial orientation of the hub components, and a relative orientation of the shape-memory members, which in turn depends on an orientation of joining of the shape-memory members with the hub components.

  18. Box-shaped halophilic bacteria.

    OpenAIRE

    Javor, B; Requadt, C; Stoeckenius, W

    1982-01-01

    Three morphologically similar strains of halophilic, box-shaped procaryotes have been isolated from brines collected in the Sinai, Baja California (Mexico), and southern California (United States). Although the isolates in their morphology resemble Walsby's square bacteria, which are a dominant morphological type in the Red Sea and Baja California brines, they are probably not identical to them. The cells show the general characteristics of extreme halophiles and archaebacteria. They contain ...

  19. Museos escolares, colecciones y la enseñanza elemental de las ciencias naturales en la Argentina de fines del siglo XIX School museums, collections, and elementary teaching of the natural sciences in late XIX century Argentina

    Directory of Open Access Journals (Sweden)

    Susana V. García

    2007-03-01

    Full Text Available En este trabajo se analiza la organización de la enseñanza de las ciencias naturales en el contexto escolar argentino a partir de las prácticas de enseñanza y los soportes materiales que se promovieron a fines del siglo XIX. En esa época, funcionarios escolares y profesores fomentaron la modernización y nacionalización de la enseñanza a partir del uso de colecciones con ejemplares del territorio nacional y la formación de museos en las escuelas. En particular, se examinan los debates oficiales sobre las colecciones mineralógicas ofrecidas en venta por el naturalista Enrique de Carlés y los "museos escolares" de los profesores Pedro Scalabrini y Guillermo Navarro que dan cuenta de las tensiones entre procurar materiales didácticos modernos, asociados a los modelos extranjeros, y la importancia de contar con elementos representativos de la naturaleza e industria nacional.In this study we analyze the organization of natural science teaching within the Argentinian school context starting with teaching practices and material support in the late XIX century. By that time, school staff and teachers fostered modernization and nationalization of teaching by using collections with national issues and the foundation of museums within the schools. In particular, we examine the official debates over the mineralogical collections offered for sale by the naturalist Enrique de Carlés, and the "school museums" by professors Pedro Scalabrini and Guillermo Navarro. These account for the tension between searching for modern didactic materials associated with foreign models, and the importance of counting on elements that represented the country nature and industry.

  20. The Hue of Shapes

    Science.gov (United States)

    Albertazzi, Liliana; Da Pos, Osvaldo; Canal, Luisa; Micciolo, Rocco; Malfatti, Michela; Vescovi, Massimo

    2013-01-01

    This article presents an experimental study on the naturally biased association between shape and color. For each basic geometric shape studied, participants were asked to indicate the color perceived as most closely related to it, choosing from the Natural Color System Hue Circle. Results show that the choices of color for each shape were not…

  1. Building with shapes

    CERN Document Server

    Mooney, Carla

    2014-01-01

    There are shapes everywhere you look. You can put shapes together or build with them. What can you build with three circles? In this title, students will explore and understand that certain attributes define what a shape is called. This title will allow students to identify the main purpose of a text, including what the author wants to answer, explain, or describe.

  2. Fuel element

    International Nuclear Information System (INIS)

    1974-01-01

    A new fuel can with a loose bottom and head is described. The fuel bar is attached to the loose bottom and head with two grid poles keeping the distance between bottom and head. A bow-shaped handle is attached to the head so that the fuel bar can be lifted from the can

  3. Alpha Shapes and Proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Sterner, Henrik; Sterner, Peter

    2009-01-01

    We provide a unified description of (weighted) alpha shapes, beta shapes and the corresponding simplicialcomplexes. We discuss their applicability to various protein-related problems. We also discuss filtrations of alpha shapes and touch upon related persistence issues.We claim that the full...... potential of alpha-shapes and related geometrical constructs in protein-related problems yet remains to be realized and verified. We suggest parallel algorithms for (weighted) alpha shapes, and we argue that future use of filtrations and kinetic variants for larger proteins will need such implementation....

  4. Minimizing tooth bending stress in spur gears with simplified shapes of fillet and tool shape determination

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2015-01-01

    by different standards, with the ISO standard probably being the most common one. Gears are manufactured using two principally different tools: rack tools and gear tools. In this work, the bending stress of involute teeth is minimized by shape optimization made directly on the final gear. This optimized shape...... is then used to find the cutting tool (the gear envelope) that can create this optimized gear shape.A simple but sufficiently flexible root parameterization is applied and emphasis is put on the importance of separating the shape parameterization from the finite element analysis of stresses. Large improvements......The strength of a gear is typically defined relative to durability (pitting) and load capacity (tooth-breakage). Tooth-breakage is controlled by the root shape and this gear part can be designed because there is no contact between gear pairs here. The shape of gears is generally defined...

  5. Transforming shape in design

    DEFF Research Database (Denmark)

    Prats, Miquel; Lim, Sungwoo; Jowers, Iestyn

    2009-01-01

    This paper is concerned with how design shapes are generated and explored by means of sketching. It presents research into the way designers transform shapes from one state to another using sketch representations. An experimental investigation of the sketching processes of designers is presented...... phenomenon of ‘subshape' and suggests that a computational mechanism for detecting sub-shapes in design sketches might augment explorative sketching by providing important opportunities for manipulating and generating shape in design........ Connections between sketches are defined in terms of shape transformations and described according to shape rules. These rules provide a formal description of the shape exploration process and develop understanding of the mechanics of sketching in design. The paper concludes by discussing the important...

  6. quadratic spline finite element method

    Directory of Open Access Journals (Sweden)

    A. R. Bahadir

    2002-01-01

    Full Text Available The problem of heat transfer in a Positive Temperature Coefficient (PTC thermistor, which may form one element of an electric circuit, is solved numerically by a finite element method. The approach used is based on Galerkin finite element using quadratic splines as shape functions. The resulting system of ordinary differential equations is solved by the finite difference method. Comparison is made with numerical and analytical solutions and the accuracy of the computed solutions indicates that the method is well suited for the solution of the PTC thermistor problem.

  7. Nuclear shapes: from earliest ideas to multiple shape coexisting structures

    International Nuclear Information System (INIS)

    Heyde, K; Wood, J L

    2016-01-01

    The concept of the atomic nucleus being characterized by an intrinsic property such as shape came as a result of high precision hyperfine studies in the field of atomic physics, which indicated a non-spherical nuclear charge distribution. Herein, we describe the various steps taken through ingenious experimentation and bold theoretical suggestions that mapped the way for later work in the early 50s by Aage Bohr, Ben Mottelson and James Rainwater. We lay out a long and winding road that marked, in the period of 50s to 70s, the way shell-model and collective-model concepts were reconciled. A rapid increase in both accelerator and detection methods (70s towards the early 2000s) opened new vistas into nuclear shapes, and their coexistence, in various regions of the nuclear mass table. Next, we outline a possible unified view of nuclear shapes: emphasizing decisive steps taken as well as questions remaining, next to the theoretical efforts that could result in an emerging understanding of nuclear shapes, building on the nucleus considered as a strongly interacting system of nucleons as the microscopic starting point. (invited comment)

  8. Groundwater quality and the relation between pH values and occurrence of trace elements and radionuclides in water samples collected from private wells in part of the Kickapoo Tribe of Oklahoma Jurisdictional Area, central Oklahoma, 2011

    Science.gov (United States)

    Becker, Carol J.

    2013-01-01

    From 1999 to 2007, the Indian Health Service reported that gross alpha-particle activities and concentrations of uranium exceeded the Maximum Contaminant Levels for public drinking-water supplies in water samples from six private wells and two test wells in a rural residential neighborhood in the Kickapoo Tribe of Oklahoma Jurisdictional Area, in central Oklahoma. Residents in this rural area use groundwater from Quaternary-aged terrace deposits and the Permian-aged Garber-Wellington aquifer for domestic purposes. Uranium and other trace elements, specifically arsenic, chromium, and selenium, occur naturally in rocks composing the Garber-Wellington aquifer and in low concentrations in groundwater throughout its extent. Previous studies have shown that pH values above 8.0 from cation-exchange processes in the aquifer cause selected metals such as arsenic, chromium, selenium, and uranium to desorb (if present) from mineral surfaces and become mobile in water. On the basis of this information, the U.S. Geological Survey, in cooperation with the Kickapoo Tribe of Oklahoma, conducted a study in 2011 to describe the occurrence of selected trace elements and radionuclides in groundwater and to determine if pH could be used as a surrogate for laboratory analysis to quickly and inexpensively identify wells that might contain high concentrations of uranium and other trace elements. The pH and specific conductance of groundwater from 59 private wells were measured in the field in an area of about 18 square miles in Lincoln and Pottawatomie Counties. Twenty of the 59 wells also were sampled for dissolved concentrations of major ions, trace elements, gross alpha-particle and gross beta-particle activities, uranium, radium-226, radium-228, and radon-222 gas. Arsenic concentrations exceeded the Maximum Contaminant Level of 10 micrograms per liter in one sample having a concentration of 24.7 micrograms per liter. Selenium concentrations exceeded the Maximum Contaminant Level of 50

  9. Nuclear fuel element

    International Nuclear Information System (INIS)

    1974-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed. A heat conducting fission product retaining metal liner of a refractory metal is incorporated in the fuel element between the cladding and the nuclear fuel to inhibit mechanical interaction between the nuclear fuel and the cladding, to isolate fission products and nuclear fuel impurities from contacting the cladding, and to improve the axial thermal peaking gradient along the length of the fuel rod. The metal liner can be in the form of a tube or hollow cylindrical column, a foil of single or multiple layers in the shape of a hollow cylindrical column, or a coating on the internal surface of the cladding. Preferred refractory metal materials are molybdenum, tungsten, rhenium, niobium and alloys of the foregoing metals

  10. PELTIER ELEMENTS

    CERN Document Server

    Tani, Laurits

    2015-01-01

    To control Peltier elements, temperature controller was used. I used TEC-1091 that was manufactured my Meerstetter Engineering. To gain control with the temperature controller, software had to be intalled on a controlling PC. There were different modes to control the Peltier: Tempererature controller to control temperature, Static current/voltage to control voltage and current and LIVE ON/OFF to auto-tune the controller respectively to the system. Also, since near the collision pipe there is much radiation, radiation-proof Peltier elements have to be used. To gain the best results, I had to find the most efficient Peltier elements and try to get their cold side to -40 degrees Celsius.

  11. Shape memory alloys

    International Nuclear Information System (INIS)

    Kaszuwara, W.

    2004-01-01

    Shape memory alloys (SMA), when deformed, have the ability of returning, in certain circumstances, to their initial shape. Deformations related to this phenomenon are for polycrystals 1-8% and up to 15% for monocrystals. The deformation energy is in the range of 10 6 - 10 7 J/m 3 . The deformation is caused by martensitic transformation in the material. Shape memory alloys exhibit one directional or two directional shape memory effect as well as pseudoelastic effect. Shape change is activated by temperature change, which limits working frequency of SMA to 10 2 Hz. Other group of alloys exhibit magnetic shape memory effect. In these alloys martensitic transformation is triggered by magnetic field, thus their working frequency can be higher. Composites containing shape memory alloys can also be used as shape memory materials (applied in vibration damping devices). Another group of composite materials is called heterostructures, in which SMA alloys are incorporated in a form of thin layers The heterostructures can be used as microactuators in microelectromechanical systems (MEMS). Basic SMA comprise: Ni-Ti, Cu (Cu-Zn,Cu-Al, Cu-Sn) and Fe (Fe-Mn, Fe-Cr-Ni) alloys. Shape memory alloys find applications in such areas: automatics, safety and medical devices and many domestic appliances. Currently the most important appears to be research on magnetic shape memory materials and high temperature SMA. Vital from application point of view are composite materials especially those containing several intelligent materials. (author)

  12. FUEL ELEMENT

    Science.gov (United States)

    Bean, R.W.

    1963-11-19

    A ceramic fuel element for a nuclear reactor that has improved structural stability as well as improved cooling and fission product retention characteristics is presented. The fuel element includes a plurality of stacked hollow ceramic moderator blocks arranged along a tubular raetallic shroud that encloses a series of axially apertured moderator cylinders spaced inwardly of the shroud. A plurality of ceramic nuclear fuel rods are arranged in the annular space between the shroud and cylinders of moderator and appropriate support means and means for directing gas coolant through the annular space are also provided. (AEC)

  13. Radiographic element

    International Nuclear Information System (INIS)

    Abbott, T.I.; Jones, C.G.

    1983-01-01

    Radiographic elements are disclosed having first and second silver halide emulsion layers comprised of a dispersing medium and radiation-sensitive silver halide grains, and a support interposed between said silver halide emulsion layers capable of transmitting radiation to which said second silver halide emulsion layer is responsive. These elements are characterized in that at least said first silver halide emulsion layer contains tabular silver halide grains and spectral sensitizing dye adsorbed to the surface of the grains. Crossover can be improved in relation to the imaging characteristics. (author)

  14. A case of impaired shape integration

    DEFF Research Database (Denmark)

    Gerlach, Christian; Marstrand, Lisbet; Habekost, Thomas

    2005-01-01

    We describe a patient, HE, who was left with a remarkably selective deficit in intermediate vision following an infarct in the right occipito-temporal region. Thus, HE was able to group elements by colour and proximity but impaired in grouping based on similarity in shape. This finding supports...

  15. Wavelength-independent laser beam shaping

    CSIR Research Space (South Africa)

    Degama, MP

    2010-07-01

    Full Text Available This paper presents a beam shaping device namely, a Diffractive Optical Element (DOE), which is used to change a beam having a Gaussian intensity profile into a beam with a uniform intensity profile. The DOE used in this work was fabricated from ZnSe...

  16. Deformable segmentation via sparse shape representation.

    Science.gov (United States)

    Zhang, Shaoting; Zhan, Yiqiang; Dewan, Maneesh; Huang, Junzhou; Metaxas, Dimitris N; Zhou, Xiang Sean

    2011-01-01

    Appearance and shape are two key elements exploited in medical image segmentation. However, in some medical image analysis tasks, appearance cues are weak/misleading due to disease/artifacts and often lead to erroneous segmentation. In this paper, a novel deformable model is proposed for robust segmentation in the presence of weak/misleading appearance cues. Owing to the less trustable appearance information, this method focuses on the effective shape modeling with two contributions. First, a shape composition method is designed to incorporate shape prior on-the-fly. Based on two sparsity observations, this method is robust to false appearance information and adaptive to statistically insignificant shape modes. Second, shape priors are modeled and used in a hierarchical fashion. More specifically, by using affinity propagation method, our deformable surface is divided into multiple partitions, on which local shape models are built independently. This scheme facilitates a more compact shape prior modeling and hence a more robust and efficient segmentation. Our deformable model is applied on two very diverse segmentation problems, liver segmentation in PET-CT images and rodent brain segmentation in MR images. Compared to state-of-art methods, our method achieves better performance in both studies.

  17. Shape-memory actuated gimbal

    Science.gov (United States)

    Carpenter, Bernie F.; Head, R. J.; Gehling, Russ

    1995-05-01

    Future spacecraft systems will require advanced positioning systems to meet stringent reliability, vibration, lightweighting, and cost requirements. Current devices employing stepping motor and gear reduction assemblies may not be able to meet future design needs. A shape memory alloy (SMA) actuated multiaxis gimbal has been developed that provides solutions to these mechanism issues. SMAs utilize a thermally activated reversible phase transformation to recover their original heat-treated shape or to generate high-recovery stresses. when heated above a critical transformation temperature. NiTiCu alloy wires have been wound into helical spring actuators to control gimbal rotation using mechanical elements to convert the linear motion of antagonistic SMA springs into rotation. Analytical models that incorporate the nonlinear hysteretic behavior of SMAs have been generated to aid in spring design and SMA conditioning. Indirect resistive hearing of SMA springs was accomplished using programmable power supplies. A potentiometer sensor attached to the output axis of the gimbal was used to provide angular feedback to a digital controller. An antagonistic approach was used to independently control heating and cooling of the opposing spring element for improved stability and bandwidth response. Proportional-integral derivative control was implemented on the active SMA spring to obtain the desired level of rotation while overcoming an external load. Mechanical testing was conducted on the gimbal to assess control system stability, dynamic response, and power requirements. Torque in excess of 3 in./lb was generated using less than 20 watts of applied power.

  18. Nuclear fuel element

    International Nuclear Information System (INIS)

    Penrose, R.T.; Thompson, J.R.

    1976-01-01

    A method of protecting the cladding of a nuclear fuel element from internal attack and a nuclear fuel element for use in the core of a nuclear reactor are disclosed. The nuclear fuel element has disposed therein an additive of a barium-containing material and the barium-containing material collects reactive gases through chemical reaction or adsorption at temperatures ranging from room temperature up to fuel element plenum temperatures. The additive is located in the plenum of the fuel element and preferably in the form of particles in a hollow container having a multiplicity of gas permeable openings in one portion of the container with the openings being of a size smaller than the size of the particles. The openings permit gases and liquids entering the plenum to contact the particles. The additive is comprised of elemental barium or a barium alloy containing one or more metals in addition to barium such as aluminum, zirconium, nickel, titanium and combinations thereof. 6 claims, 3 drawing figures

  19. Perspectives in shape analysis

    CERN Document Server

    Bruckstein, Alfred; Maragos, Petros; Wuhrer, Stefanie

    2016-01-01

    This book presents recent advances in the field of shape analysis. Written by experts in the fields of continuous-scale shape analysis, discrete shape analysis and sparsity, and numerical computing who hail from different communities, it provides a unique view of the topic from a broad range of perspectives. Over the last decade, it has become increasingly affordable to digitize shape information at high resolution. Yet analyzing and processing this data remains challenging because of the large amount of data involved, and because modern applications such as human-computer interaction require real-time processing. Meeting these challenges requires interdisciplinary approaches that combine concepts from a variety of research areas, including numerical computing, differential geometry, deformable shape modeling, sparse data representation, and machine learning. On the algorithmic side, many shape analysis tasks are modeled using partial differential equations, which can be solved using tools from the field of n...

  20. Cell-level finite element studies of viscous cells in planar aggregates.

    Science.gov (United States)

    Chen, H H; Brodland, G W

    2000-08-01

    A new cell-level finite element formulation is presented and used to investigate how epithelia and other planar collections of viscous cells might deform during events such as embryo morphogenesis and wound healing. Forces arising from cytoskeletal components, cytoplasm viscosity, and cell-cell adhesions are included. Individual cells are modeled using multiple finite elements, and cell rearrangements can occur. Simulations of cell-sheet stretching indicate that the initial stages of sheet stretching are characterized by changes in cell shape, while subsequent stages are governed by cell rearrangement. Inferences can be made from the simulations about the forces that act in real cell sheets when suitable experimental data are available.

  1. Shaping of planetary nebulae

    International Nuclear Information System (INIS)

    Balick, B.

    1987-01-01

    The phases of stellar evolution and the development of planetary nebulae are examined. The relation between planetary nebulae and red giants is studied. Spherical and nonspherical cases of shaping planetaries with stellar winds are described. CCD images of nebulae are analyzed, and it is determined that the shape of planetary nebulae depends on ionization levels. Consideration is given to calculating the distances of planetaries using radio images, and molecular hydrogen envelopes which support the wind-shaping model of planetary nebulae

  2. Shape Optimization of Cochlear Implant Electrode Array Using Genetic Algorithms

    National Research Council Canada - National Science Library

    Choi, Charles

    2001-01-01

    .... Genetic algorithms are then applied in conjunction with the finite element analysis to optimize the shape of cochlear implant electrode array based on the energy deposited in the spiral ganglion cells region...

  3. Mobile genetic elements in protozoan parasites

    Indian Academy of Sciences (India)

    Mobile genetic elements, by virtue of their ability to move to new chromosomal locations, are considered important in shaping the evolutionary course of the genome. They are widespread in the biological kingdom. Among the protozoan parasites several types of transposable elements are encountered. The largest variety ...

  4. Discriminative Shape Alignment

    DEFF Research Database (Denmark)

    Loog, M.; de Bruijne, M.

    2009-01-01

    , not taking into account that eventually the shapes are to be assigned to two or more different classes. This work introduces a discriminative variation to well-known Procrustes alignment and demonstrates its benefit over this classical method in shape classification tasks. The focus is on two...

  5. Shape from touch

    NARCIS (Netherlands)

    Kappers, A.M.L.; Bergmann Tiest, W.M.

    2014-01-01

    The shape of objects cannot only be recognized by vision, but also by touch. Vision has the advantage that shapes can be seen at a distance, but touch has the advantage that during exploration many additional object properties become available, such as temperature (Jones, 2009), texture (Bensmaia,

  6. Tunable pulse-shaping with gated graphene nanoribbons

    DEFF Research Database (Denmark)

    Prokopeva, Ludmila; Emani, Naresh K.; Boltasseva, Alexandra

    2014-01-01

    We propose a pulse-shaper made of gated graphene nanoribbons. Simulations demonstrate tunable control over the shapes of transmitted and reflected pulses using the gating bias. Initial fabrication and characterization of graphene elements is also discussed.......We propose a pulse-shaper made of gated graphene nanoribbons. Simulations demonstrate tunable control over the shapes of transmitted and reflected pulses using the gating bias. Initial fabrication and characterization of graphene elements is also discussed....

  7. Static analysis of C-shape SMA middle ear prosthesis

    Science.gov (United States)

    Latalski, Jarosław; Rusinek, Rafał

    2017-08-01

    Shape memory alloys are a family of metals with the ability to change specimen shape depending on their temperature. This unique property is useful in many areas of mechanical and biomechanical engineering. A new half-ring middle ear prosthesis design made of a shape memory alloy, that is undergoing initial clinical tests, is investigated in this research paper. The analytical model of the studied structure made of nonlinear constitutive material is solved to identify the temperature-dependent stiffness characteristics of the proposed design on the basis of the Crotti-Engesser theorem. The final integral expression for the element deflection is highly complex, thus the solution has to be computed numerically. The final results show the proposed shape memory C-shape element to behave linearly in the analysed range of loadings and temperatures. This is an important observation that significantly simplifies the analysis of the prototype structure and opens wide perspectives for further possible applications of shape memory alloys.

  8. A set of robotic building elements

    DEFF Research Database (Denmark)

    2017-01-01

    A set of building elements (900), comprising one or more building elements (101;701;901..907) with a housing (119) which is selected from a group of straight, bend, L-shaped, and T-shaped bodies with one or more end-portions (121); wherein the building elements are configured with at least one...... building element. A drive unit (114) is coupled to turn the first one of connectors (103) in response to a control signal and an energy storage unit (117) is coupled to supply operating power the drive unit. Preferably, the body members (119) are tubular or tubular with one or more branches....... or greater than a width (Wf) of the female engagement member. At least a first building element among the building elements (101;701) comprises at least a first one of the connectors (103); wherein the at least first one of the connectors (103) is rotatable mounted in a bearing (108) fixed to the first...

  9. Beam shaping element for compact fiber injection systems

    Energy Technology Data Exchange (ETDEWEB)

    Weichman, L.S.; Dickey, F.M.; Shagam, R.N.

    2000-01-05

    Injection of high power, multi-mode laser profiles into a fiber optic delivery system requires controlling a number of injection parameters to maximize throughput and minimize concerns for optical damage both at the entrance and exit faces of the fiber optic. A simple method for simultaneously achieving a compact fiber injection geometry and control of these injection parameters, independent of the input source characteristics, is provided by a refractive lenslet array and simple injection lens configuration. Design criteria together with analytical and experimental results for the refractive lenslet array and short focal length injection lens are presented. This arrangement provides a uniform spatial intensity distribution at the fiber injection plane to a large degree independent of the source mode structure, spatial profile, divergence, size, and/or alignment to the injection system. This technique has application to a number of laser systems where uniform illumination of a target or remote delivery of high peak power is desired.

  10. How to Shape Markets Through Design Elements Such as Logos?

    DEFF Research Database (Denmark)

    Kristensen, Tore; Gabrielsen, Gorm

    In this paper, we use logo design as means of showing how variation it the consumer’s perceptions can influence the effectiveness of a market. It is often assumed that consumers perceive the same message when they explore options in a market. If they actually see different things in a logo, like...... understanding the intended mission statement, the market is not working 100%. We refer to this as idiosyncratic variation which simply means that people see different things. This paper is an attempt to analyse different designs of logos to see how one can improve the common understanding of a logo and thereby...

  11. Structural Shape Optimisation by Iterative Finite Element Solution

    National Research Council Canada - National Science Library

    Kaye, R

    1997-01-01

    This report presents the development and automated numerical implementation of an iterative gradientless optimisation method for the analysis of problems relating to life extension of aircraft components...

  12. Some Issues of Biological Shape Modelling with Applications

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Hilger, Klaus Baggesen; Skoglund, Karl

    2003-01-01

    This paper illustrates current research at Informatics and Mathematical Modelling at the Technical University of Denmark within biological shape modelling. We illustrate a series of generalizations to, modifications to, and applications of the elements of constructing models of shape or appearanc...

  13. Analysis of acoustic resonator with shape deformation using finite ...

    Indian Academy of Sciences (India)

    An acoustic resonator with shape deformation has been analysed using the finite element method. The shape deformation issuch that the volume of the resonator remains constant. The effect of deformation on the resonant frequencies is studied. Deformation splits the degenerate frequencies.

  14. Shape Optimization of Revolute-Jointed Rigid-Flexible Manipulator

    Science.gov (United States)

    Mahto, S.; Dixit, U. S.

    2014-10-01

    This work illustrates the shape optimization of flexible link of revolute-jointed rigid-flexible manipulator. Flexible link is considered as Euler-Bernoulli beam and dynamic analysis is carried out by finite element based on Langrange approach. Nonlinear classical search technique (Sequential Quadratic Programming method) is applied to extremize the four different objectives. Different optimized shapes are obtained for different optimization problems. Optimized shapes improve the static and dynamic response of the system viz. fundamental frequency, hub angles, flexural vibration, etc.

  15. Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    M.H.R. Ghoreishy

    2008-02-01

    Full Text Available This research work is devoted to the footprint analysis of a steel-belted radial tyre (185/65R14 under vertical static load using finite element method. Two models have been developed in which in the first model the tread patterns were replaced by simple ribs while the second model was consisted of details of the tread blocks. Linear elastic and hyper elastic (Arruda-Boyce material models were selected to describe the mechanical behavior of the reinforcing and rubbery parts, respectively. The above two finite element models of the tyre were analyzed under inflation pressure and vertical static loads. The second model (with detailed tread patterns was analyzed with and without friction effect between tread and contact surfaces. In every stage of the analysis, the results were compared with the experimental data to confirm the accuracy and applicability of the model. Results showed that neglecting the tread pattern design not only reduces the computational cost and effort but also the differences between computed deformations do not show significant changes. However, more complicated variables such as shape and area of the footprint zone and contact pressure are affected considerably by the finite element model selected for the tread blocks. In addition, inclusion of friction even in static state changes these variables significantly.

  16. The exchangeability of shape

    Directory of Open Access Journals (Sweden)

    Kaba Dramane

    2010-10-01

    Full Text Available Abstract Background Landmark based geometric morphometrics (GM allows the quantitative comparison of organismal shapes. When applied to systematics, it is able to score shape changes which often are undetectable by traditional morphological studies and even by classical morphometric approaches. It has thus become a fast and low cost candidate to identify cryptic species. Due to inherent mathematical properties, shape variables derived from one set of coordinates cannot be compared with shape variables derived from another set. Raw coordinates which produce these shape variables could be used for data exchange, however they contain measurement error. The latter may represent a significant obstacle when the objective is to distinguish very similar species. Results We show here that a single user derived dataset produces much less classification error than a multiple one. The question then becomes how to circumvent the lack of exchangeability of shape variables while preserving a single user dataset. A solution to this question could lead to the creation of a relatively fast and inexpensive systematic tool adapted for the recognition of cryptic species. Conclusions To preserve both exchangeability of shape and a single user derived dataset, our suggestion is to create a free access bank of reference images from which one can produce raw coordinates and use them for comparison with external specimens. Thus, we propose an alternative geometric descriptive system that separates 2-D data gathering and analyzes.

  17. What shapes output of policy reform?

    DEFF Research Database (Denmark)

    Carlsen, Kirsten

    and personal benefits. Rather, the thesis shows how state actors decisions are shaped by a complex inter-relation of circumstances, interests and resources at play during the level of policy implementation. Thesis findings are based on collection and analysis of qualitative data collected from actors within...... and with a particular focus on the factors influencing reform output. The main message is that state actor decisions are central determinants for the ways in which reform output is shaped. It contests political economy theory by showing that these decisions are not only determined by state actors sole pursuit of power...

  18. Mathematical and computer modeling of component surface shaping

    Science.gov (United States)

    Lyashkov, A.

    2016-04-01

    The process of shaping technical surfaces is an interaction of a tool (a shape element) and a component (a formable element or a workpiece) in their relative movements. It was established that the main objects of formation are: 1) a discriminant of a surfaces family, formed by the movement of the shape element relatively the workpiece; 2) an enveloping model of the real component surface obtained after machining, including transition curves and undercut lines; 3) The model of cut-off layers obtained in the process of shaping. When modeling shaping objects there are a lot of insufficiently solved or unsolved issues that make up a single scientific problem - a problem of qualitative shaping of the surface of the tool and then the component surface produced by this tool. The improvement of known metal-cutting tools, intensive development of systems of their computer-aided design requires further improvement of the methods of shaping the mating surfaces. In this regard, an important role is played by the study of the processes of shaping of technical surfaces with the use of the positive aspects of analytical and numerical mathematical methods and techniques associated with the use of mathematical and computer modeling. The author of the paper has posed and has solved the problem of development of mathematical, geometric and algorithmic support of computer-aided design of cutting tools based on computer simulation of the shaping process of surfaces.

  19. Shaping light with MOEMS

    Science.gov (United States)

    Noell, W.; Weber, S.; Masson, J.; Extermann, J.; Bonacina, L.; Bich, A.; Bitterli, R.; Herzig, H. P.; Kiselev, D.; Scharf, T.; Voelkel, R.; Weible, K. J.; Wolf, J.-P.; de Rooij, N. F.

    2011-03-01

    Shaping light with microtechnology components has been possible for many years. The Texas Instruments digital micromirror device (DMD) and all types of adaptive optics systems are very sophisticated tools, well established and widely used. Here we present, however, two very dedicated systems, where one is an extremely simple MEMS-based tunable diffuser, while the second device is complex micromirror array with new capabilities for femtosecond laser pulse shaping. Showing the two systems right next to each other demonstrates the vast options and versatility of MOEMS for shaping light in the space and time domain.

  20. Reflections on collectivity

    International Nuclear Information System (INIS)

    Feshbach, H.

    1983-01-01

    Comments are made on papers presented to the International School of Nuclear Physics, Erice (1982) concerning collective bands and collectivity in nuclei. The importance of these collective modes of motion, the role of the Bohr-Mottelson model and the Interacting Boson Models (IBM-1 and IBM-2), and experimental evidence presented by a number of workers, are examined. The extensions of the models to take into account additional degrees of freedom both collective and non-collective, the discovery of new collective modes such as those corresponding to tri-axial shapes, and the possible existence of additional symmetries reported at the meeting, are discussed. Finally the importance is examined of relating the phenomenological models to a more fundamental underlying theory, which has been taken to be the nuclear shell model. (U.K.)

  1. Shape and topology optimization of enzymatic microreactors

    DEFF Research Database (Denmark)

    Pereira Rosinha, Ines

    of extensive experimental work to find the best reactor configuration.Shape optimization has been applied to an YY-microreactor with a rectangular cross-section withthe intention to investigate the shape influence on the active mixing of substances and consequently in the reaction yield. The inlet...... with a selfprogrammedMATLAB® code. ANSYS CFX® performs the discretization of the microreactorinto finite volume elements and calculates the main reactor outputs. The MATLAB® routine performs the optimization by changing the geometry. Furthermore, it includes the evaluation of the objective function, the new definition...

  2. Nuclear fuel element end fitting

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1979-01-01

    A typical embodiment of the invention has an array of sockets that are welded to the intersections of the plates that form the upper and lower end fittings of a nuclear reactor fuel element. The sockets, which are generally cylindrical in shape, are oriented in directions that enable the longitudinal axes of the sockets to align with the longitudinal axes of the fuel rods that are received in the respective sockets. Detents impressed in the surfaces of the sockets engage mating grooves that are formed in the ends of the fuel rods to provide for the structural integrity of the fuel element

  3. Shape memory polyurethane nanocomposites

    Science.gov (United States)

    Cao, Feina

    Shape memory polymers are smart materials which can remember their original shapes. However, the low recovery stress and low mechanical strength limit the commercial applications of shape memory polymers. In this study, nanoclays were introduced to shape memory polyurethanes (SMPU) to augment these properties by enhance the network of SMPU. Several factors which influence the shape recovery stress were evaluated, including the nature of polymer chain by using different monomers, type of clay particles, extent of filler dispersion, clay content and deformation conditions. It was found that only reactive clay particles were well dispersed into polyurethane matrix by the tethering between --CH2CH 2OH functional groups in clay surfactants and polyurethane chains. Two different shape memory polyurethanes (Systems I & II) prepared by bulk polymerization were compared. The shape memory effect of System I was triggered by melting of the soft segment crystals, while that of System II was by glass transition of the soft segments. It was seen that the reactive clay particles dispersed well in both polyurethane matrices and augmented the recovery stress, e.g., 20% increase with 1 wt % nanoclay in System I and 40% increase with 5 wt % nanoclay in System II were observed. In System I, clay particles interfered with soft segment crystallization, and promoted phase mixing between the hard and soft segments, thus affecting the fixity and recovery ratio. Nevertheless, the soft segment crystallinity was still enough and in some cases increased due to stretching to exhibit excellent shape fixity and shape recovery ratio. The higher loading of clay particles accelerated the stress relaxation, resulting in reduction of recovery stress. In System II, no significant effect of clay particles in phase separation was observed, so there was no influence of clay on shape fixity and recovery ratio. The recovery stress increased with reactive nanoclay content. It was also found that the recovery

  4. Shaping the Global Environment

    Science.gov (United States)

    2002-04-09

    SHAPING THE GLOBAL ENVIRONMENT BY LIEUTENANT COLONEL MICHAEL D. ELLERBE United States Army DISTRIBUTION STATEMENT A: Approved for public release...THE GLOBAL ENVIRONMENT by Lieutenant Colonel Michael D. Ellerbe United States Army Colonel Jef Troxel Project Advisor The views expressed in this...Distribution is unlimited. ii ABSTRACT AUTHOR: Michael D. Ellerbe TITLE: SHAPING THE GLOBAL ENVIRONMENT FORMAT: Strategy Research Project DATE: 09 April

  5. Shear Capacity of C-Shaped and L-Shaped Angle Shear Connectors.

    Directory of Open Access Journals (Sweden)

    Farzad Tahmasbi

    Full Text Available This paper investigates the behaviour of C-shaped and L-shaped angle shear connectors embedded in solid concrete slabs. An effective finite element model is proposed to simulate the push out tests of these shear connectors that encompass nonlinear material behaviour, large displacement and damage plasticity. The finite element models are validated against test results. Parametric studies using this nonlinear model are performed to investigate the variations in concrete strength and connector dimensions. The finite element analyses also confirm the test results that increasing the length of shear connector increases their shear strength proportionately. It is observed that the maximum stress in L-shaped angle connectors takes place in the weld attachment to the beam, whereas in the C-shaped angle connectors, it is in the attached leg. The location of maximum concrete compressive damage is rendered in each case. Finally, a new equation for prediction of the shear capacity of C-shaped angle connectors is proposed.

  6. Shape memory alloy engine

    International Nuclear Information System (INIS)

    Tanaka, M.

    1992-01-01

    This paper discusses a shape memory alloy engine, developed for the purpose of extracting the mechanical energy from a small difference in temperature. The engine is mainly composed of two pulleys (high temperature and low temperature) and single belt made of the nickel titanium shape memory alloy. The alloy memorizes a shape arcing in the direction opposite to the direction of the belt arc around the pulleys. When the temperature of the belt which is in contact with the high temperature pulley rises above the transformation temperature, a return to the memorized shape generates a force which rotates the pulleys. To make the heat transfer more effective, the engine was designed so that the lower part of the two pulleys are embedded in hot and cold water, respectively. To predict the performance of the shape memory alloy engine, the stress change of the shape memory alloy caused by temperature change has been also investigated with the bending stress test, and a torque loss of the engine system was measured. The predicted results were coincident with the output power experiment

  7. On Characterizing Particle Shape

    Science.gov (United States)

    Ennis, Bryan J.; Rickman, Douglas; Rollins, A. Brent; Ennis, Brandon

    2014-01-01

    It is well known that particle shape affects flow characteristics of granular materials, as well as a variety of other solids processing issues such as compaction, rheology, filtration and other two-phase flow problems. The impact of shape crosses many diverse and commercially important applications, including pharmaceuticals, civil engineering, metallurgy, health, and food processing. Two applications studied here include the dry solids flow of lunar simulants (e.g. JSC-1, NU-LHT-2M, OB-1), and the flow properties of wet concrete, including final compressive strength. A multi-dimensional generalized, engineering method to quantitatively characterize particle shapes has been developed, applicable to both single particle orientation and multi-particle assemblies. The two-dimension, three dimension inversion problem is also treated, and the application of these methods to DEM model particles will be discussed. In the case of lunar simulants, flow properties of six lunar simulants have been measured, and the impact of particle shape on flowability - as characterized by the shape method developed here -- is discussed, especially in the context of three simulants of similar size range. In the context of concrete processing, concrete construction is a major contributor to greenhouse gas production, of which the major contributor is cement binding loading. Any optimization in concrete rheology and packing that can reduce cement loading and improve strength loading can also reduce currently required construction safety factors. The characterization approach here is also demonstrated for the impact of rock aggregate shape on concrete slump rheology and dry compressive strength.

  8. Fuel element

    International Nuclear Information System (INIS)

    Hirose, Yasuo.

    1982-01-01

    Purpose: To increase the plenum space in a fuel element used for a liquid metal cooled reactor. Constitution: A fuel pellet is secured at one end with an end plug and at the other with a coil spring in a tubular container. A mechanism for fixing the coil spring composed of a tubular unit is mounted by friction with the inner surface of the tubular container. Accordingly, the recoiling force of the coil spring can be retained by fixing mechanism with a small volume, and since a large amount of plenum space can be obtained, the internal pressure rise in the cladding tube can be suppressed even if large quantities of fission products are discharged. (Kamimura, M.)

  9. Shapes of interacting RNA complexes

    DEFF Research Database (Denmark)

    Fu, Benjamin Mingming; Reidys, Christian

    2014-01-01

    Shapes of interacting RNA complexes are studied using a filtration via their topological genus. A shape of an RNA complex is obtained by (iteratively) collapsing stacks and eliminating hairpin loops.This shape-projection preserves the topological core of the RNA complex and for fixed topological...... genus there are only finitely many such shapes. Our main result is a new bijection that relates the shapes of RNA complexes with shapes of RNA structures. This allows to compute the shape polynomial of RNA complexes via the shape polynomial of RNA structures. We furthermore present a linear time uniform...... sampling algorithm for shapes of RNA complexes of fixed topological genus....

  10. Collection Mapping.

    Science.gov (United States)

    Harbour, Denise

    2002-01-01

    Explains collection mapping for library media collections. Discusses purposes for creating collection maps, including helping with selection and weeding decisions, showing how the collection supports the curriculum, and making budget decisions; and methods of data collection, including evaluating a collaboratively taught unit with the classroom…

  11. Nuclear reactor fuel element

    International Nuclear Information System (INIS)

    Steinke, A.

    1985-01-01

    The grid-shaped spacer for PWR fuel elements consists of flat, upright metal bars at right angles to the fuel rods. In one corner of a grid mesh it has a spring with two end parts for the fuel rod. The cut-outs for the end parts start from an end edge of the metal bar parallel to the fuel rods. The transverse metal bar is one of four outer metal bars. Both end parts of the spring have an extension parallel to this outer metal arm, which grips a grid mesh adjacent to this grid mesh at the side in one corner of the spacer and forms an end part of a spring for the fuel rod there on the inside of the outer metal bar. (HP) [de

  12. Statistical finite element analysis.

    Science.gov (United States)

    Khalaji, Iman; Rahemifar, Kaamran; Samani, Abbas

    2008-01-01

    A novel technique is introduced for tissue deformation and stress analysis. Compared to the conventional Finite Element method, this technique is orders of magnitude faster and yet still very accurate. The proposed technique uses preprocessed data obtained from FE analyses of a number of similar objects in a Statistical Shape Model framework as described below. This technique takes advantage of the fact that the body organs have limited variability, especially in terms of their geometry. As such, it is well suited for calculating tissue displacements of body organs. The proposed technique can be applied in many biomedical applications such as image guided surgery, or virtual reality environment development where tissue behavior is simulated for training purposes.

  13. Determination of toxic elements in Malaysian foodstuffs

    International Nuclear Information System (INIS)

    Hamzah, Z.; Wood, A.K.H.; Mahmood, C.S.; Hamzah, S.

    1988-01-01

    This project is concentrating on the analysis of toxic elements content in seafoods including fishes, mussel, squid and prawn. Samples were collected from various places throughout Malay Peninsular. Samples were prepared according to RCA research protocol - nuclear techniques for toxic element in foodstuffs. Techniques used for elemental analysis were neutron activation analysis (instrumental and radiochemical) and anodic stripping voltametry. (author). 9 refs, 9 tabs

  14. Shape coexistence and the role of axial asymmetry in 72Ge

    Directory of Open Access Journals (Sweden)

    A.D. Ayangeakaa

    2016-03-01

    Full Text Available The quadrupole collectivity of low-lying states and the anomalous behavior of the 02+ and 23+ levels in 72Ge are investigated via projectile multi-step Coulomb excitation with GRETINA and CHICO-2. A total of forty six E2 and M1 matrix elements connecting fourteen low-lying levels were determined using the least-squares search code, gosia. Evidence for triaxiality and shape coexistence, based on the model-independent shape invariants deduced from the Kumar–Cline sum rule, is presented. These are interpreted using a simple two-state mixing model as well as multi-state mixing calculations carried out within the framework of the triaxial rotor model. The results represent a significant milestone towards the understanding of the unusual structure of this nucleus.

  15. Nuclear quantum shape-phase transitions in odd-mass systems

    Science.gov (United States)

    Quan, S.; Li, Z. P.; Vretenar, D.; Meng, J.

    2018-03-01

    Microscopic signatures of nuclear ground-state shape-phase transitions in odd-mass Eu isotopes are explored starting from excitation spectra and collective wave functions obtained by diagonalization of a core-quasiparticle coupling Hamiltonian based on energy density functionals. As functions of the physical control parameter—the number of nucleons—theoretical low-energy spectra, two-neutron separation energies, charge isotope shifts, spectroscopic quadrupole moments, and E 2 reduced transition matrix elements accurately reproduce available data and exhibit more-pronounced discontinuities at neutron number N =90 compared with the adjacent even-even Sm and Gd isotopes. The enhancement of the first-order quantum phase transition in odd-mass systems can be attributed to a shape polarization effect of the unpaired proton which, at the critical neutron number, starts predominantly coupling to Gd core nuclei that are characterized by larger quadrupole deformation and weaker proton pairing correlations compared with the corresponding Sm isotopes.

  16. Solving the shape conundrum in $^{70}$Se

    CERN Multimedia

    We propose a multi-step Coulomb-excitation study of $^{70}$Se at HIE-ISOLDE using the $^{208}$Pb( $^{70}$Se, $^{70}$Se*)$^{208}$Pb* reaction at a safe energy of 5.0 MeV/u. We aim at a precise measurement of the $\\left \\langle 2^{+}_{1} \\hspace{0.1cm} || \\hspace{0.1cm}\\hat{E}2 \\hspace{0.1cm} || \\hspace{0.1cm}2^{+}_{ 1} \\right \\rangle$ diagonal matrix element as well as gaining information on additional matrix elements. Such information will shed light onto the shape conundrum of the 2$^{+}_{1}$ state in $^{70}$Se as well as foreseeing the opportunity for a more detailed understanding of the shape-coexistence phenomenon in this region.

  17. Element Free Lattice Boltzmann Method for Fluid-Flow Problems

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Chull; Roh, Kyung Wan; Yune, Young Gill; Kim, Hho Jhung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kwon, Young Kwon [US Naval Postgraduate School, New York (United States)

    2007-10-15

    The Lattice Boltzmann Method (LBM) has been developed for application to thermal-fluid problems. Most of the those studies considered a regular shape of lattice or mesh like square and cubic grids. In order to apply the LBM to more practical cases, it is necessary to be able to solve complex or irregular shapes of problem domains. Some techniques were based on the finite element method. Generally, the finite element method is very powerful for solving two or three-dimensional complex or irregular shapes of domains using the iso-parametric element formulation which is based on a mathematical mapping from a regular shape of element in an imaginary domain to a more general and irregular shape of element in the physical domain. In addition, the element free technique is also quite useful to analyze a complex shape of domain because there is no need to divide a domain by a compatible finite element mesh. This paper presents a new finite element and element free formulations for the lattice Boltzmann equation using the general weighted residual technique. Then, a series of validation examples are presented.

  18. Power corrections and event shapes at LEP

    CERN Document Server

    Sanders, Michiel P

    2000-01-01

    Measurements of event shape variables from hadronic events collected by the LEP experiments, corresponding to hadronic center of mass energies between 30 GeV and 202 GeV are presented. Fits are performed to extract a, and the effective infrared strong coupling o with the power correction ansatz. Universality is observed for the effective coupling and comparisons are made with fragmentation models.

  19. SHAPE selection (SHAPES) enrich for RNA structure signal in SHAPE sequencing-based probing data

    DEFF Research Database (Denmark)

    Poulsen, Line Dahl; Kielpinski, Lukasz Jan; Salama, Sofie R

    2015-01-01

    transcriptase. Here, we introduce a SHAPE Selection (SHAPES) reagent, N-propanone isatoic anhydride (NPIA), which retains the ability of SHAPE reagents to accurately probe RNA structure, but also allows covalent coupling between the SHAPES reagent and a biotin molecule. We demonstrate that SHAPES...

  20. Element Method

    Directory of Open Access Journals (Sweden)

    Fong Kah Soon

    2017-01-01

    Full Text Available The vibration of damped pipeline conveying fluid with the effect of fluid-structure interaction is known to pose challenging problems in oil and gas industry. In this study, the natural frequency of fluid-structure interaction in pipeline conveying fluid set on viscoelastic foundation is investigated by using finite element method. The governing partial differential equation is modelled based on Euler-Bernoulli beam theory. By applying Galerkin weighted residual method, the stiffness, damping, and mass matrices are obtained. For a given boundary condition which is simply supported, two components of the foundation (foundation stiffness and damping which are influencing the damped natural frequency of the pipeline are studied for different fluid velocity. The results indicate that increasing the foundation stiffness from 10 kN/m3 to 30 kN/m3 increases the natural frequency of the pipeline, while increasing the foundation damping from 1 kN.s/m3 to 3 kN.s/m3 and fluid velocity decrease the natural frequency of the pipeline. The accuracy of the results obtained is validated against data from literature.

  1. Shape memory polymer medical device

    Science.gov (United States)

    Maitland, Duncan [Pleasant Hill, CA; Benett, William J [Livermore, CA; Bearinger, Jane P [Livermore, CA; Wilson, Thomas S [San Leandro, CA; Small, IV, Ward; Schumann, Daniel L [Concord, CA; Jensen, Wayne A [Livermore, CA; Ortega, Jason M [Pacifica, CA; Marion, III, John E.; Loge, Jeffrey M [Stockton, CA

    2010-06-29

    A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.

  2. Shape memory alloys as damping materials

    International Nuclear Information System (INIS)

    Humbeeck, J. van

    2000-01-01

    Shape memory alloys are gaining an increased interest as passive as well as active damping materials. This damping ability when applied in structural elements can lead to a better noise control, improved life time and even better performance of the envisaged tools. By passive damping, it is understood that the material converts a significant part of unwanted mechanical energy into heat. This mechanical energy can be a (resonance) vibration, impact loading or shock waves. This high damping capacity finds its origin in the thermoelastic martensitic phase due to the hysteretic mobility of martensite-variants or different phase interfaces. The damping capacity increases with increasing amplitude of the applied vibration or impact and is almost frequency independent. Special interest exists moreover for damping extreme large displacements by applying the mechanical hysteresis performed during pseudoelastic loading. This aspect is nowadays very strongly studied as a tool for protecting buildings against earthquakes in seismic active regions. Active damping can be obtained in hybrid composites by controlling the recovery stresses or strains of embedded shape memory alloy wires. This controls the internal energy fo a structure which allows controlled modal modification and tuning of the dynamical properties of structural elements. But also impact damage, acoustic radiation, dynamic shape control can be actively controlled. As a consequence improved fatigue-resistance, better performance and a longer lifetime of the structural elements can be obtained. (orig.)

  3. Jet Shapes at CMS

    CERN Document Server

    Kurt, Pelin

    2008-01-01

    The CMS (Compact Muon Solenoid) detector will observe high transverse momentum jets produced in the final state of proton-proton collisions at the center of mass energy of 14 TeV. These data will allow us to measure jet shapes, defined as the fractional transverse momentum distribution as a function of the distance from the jet axis. Since jet shapes are sensitive to parton showering processes they provide a good test of Monte Carlo event simulation programs. In this note we present a study of jet shapes reconstructed using calorimeter energies. We compare the predictions of the Monte Carlo generators PYTHIA and HERWIG++. Presented results are expected for $pp$ collisions at 14 TeV assuming an integrated luminosity of 10 pb$^{-1}$.

  4. Laser beam shaping techniques

    Energy Technology Data Exchange (ETDEWEB)

    DICKEY,FRED M.; WEICHMAN,LOUIS S.; SHAGAM,RICHARD N.

    2000-03-16

    Industrial, military, medical, and research and development applications of lasers frequently require a beam with a specified irradiance distribution in some plane. A common requirement is a laser profile that is uniform over some cross-section. Such applications include laser/material processing, laser material interaction studies, fiber injection systems, optical data image processing, lithography, medical applications, and military applications. Laser beam shaping techniques can be divided into three areas: apertured beams, field mappers, and multi-aperture beam integrators. An uncertainty relation exists for laser beam shaping that puts constraints on system design. In this paper the authors review the basics of laser beam shaping and present applications and limitations of various techniques.

  5. Directions for nuclear research in the transplutonium elements

    International Nuclear Information System (INIS)

    Wilhelmy, J.B.; Chasman, R.R.; Friedman, A.M.; Ahmad, I.

    1983-01-01

    The study of the heavy nuclides has played a vital role in our understanding of the alpha decay process, nuclear fission, nuclear binding energies and the limits of nuclear stability. This study has led to the understanding of novel shape degrees of freedom, such as the very large quadrupole deformations associated with the fission isomer process, and the very recently discovered octupole deformation. The existence of these unique phenomena in the heavy element region is not accidental. Fission isomerism is due to the delicate balance between nuclear forces holding the nucleus together and Coulomb forces causing nuclear fission. Octupole deformation arises from the increasing strength of matrix elements with increasing oscillator shell. Both illustrate the unique features of the heavy element region. Fission studies have given us information about large collective aspects in nuclei and the importance that nuclear structural effects can play in altering these macro properties. A new class of atomic studies has become possible with the availability of heavy elements. With these isotopes, we are now able to produce electric fields of such magnitude that it becomes possible to spontaneously create positron-electron pairs in the vacuum. We have organized this presentation into three major sections: nuclear structure, fission studies and atomic studies of supercritical systems. In each we will try to emphasize the new directions which can benefit from the continued availability of isotopes supplied by the Trans-plutonium Production Program. 117 references

  6. AUTOMATIC RECOGNITION OF INDOOR NAVIGATION ELEMENTS FROM KINECT POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    L. Zeng

    2017-09-01

    Full Text Available This paper realizes automatically the navigating elements defined by indoorGML data standard – door, stairway and wall. The data used is indoor 3D point cloud collected by Kinect v2 launched in 2011 through the means of ORB-SLAM. By contrast, it is cheaper and more convenient than lidar, but the point clouds also have the problem of noise, registration error and large data volume. Hence, we adopt a shape descriptor – histogram of distances between two randomly chosen points, proposed by Osada and merges with other descriptor – in conjunction with random forest classifier to recognize the navigation elements (door, stairway and wall from Kinect point clouds. This research acquires navigation elements and their 3-d location information from each single data frame through segmentation of point clouds, boundary extraction, feature calculation and classification. Finally, this paper utilizes the acquired navigation elements and their information to generate the state data of the indoor navigation module automatically. The experimental results demonstrate a high recognition accuracy of the proposed method.

  7. Automatic Recognition of Indoor Navigation Elements from Kinect Point Clouds

    Science.gov (United States)

    Zeng, L.; Kang, Z.

    2017-09-01

    This paper realizes automatically the navigating elements defined by indoorGML data standard - door, stairway and wall. The data used is indoor 3D point cloud collected by Kinect v2 launched in 2011 through the means of ORB-SLAM. By contrast, it is cheaper and more convenient than lidar, but the point clouds also have the problem of noise, registration error and large data volume. Hence, we adopt a shape descriptor - histogram of distances between two randomly chosen points, proposed by Osada and merges with other descriptor - in conjunction with random forest classifier to recognize the navigation elements (door, stairway and wall) from Kinect point clouds. This research acquires navigation elements and their 3-d location information from each single data frame through segmentation of point clouds, boundary extraction, feature calculation and classification. Finally, this paper utilizes the acquired navigation elements and their information to generate the state data of the indoor navigation module automatically. The experimental results demonstrate a high recognition accuracy of the proposed method.

  8. A consistent partly cracked XFEM element for cohesive crack growth

    DEFF Research Database (Denmark)

    Asferg, Jesper L.; Poulsen, Peter Noe; Nielsen, Leif Otto

    2007-01-01

    Present extended finite element method (XFEM) elements for cohesive crack growth may often not be able to model equal stresses on both sides of the discontinuity when acting as a crack-tip element. The authors have developed a new partly cracked XFEM element for cohesive crack growth with extra...... enrichments to the cracked elements. The extra enrichments are element side local and were developed by superposition of the standard nodal shape functions for the element and standard nodal shape functions for a sub-triangle of the cracked element. With the extra enrichments, the crack-tip element becomes...... capable of modelling variations in the discontinuous displacement field on both sides of the crack and hence also capable of modelling the case where equal stresses are present on each side of the crack. The enrichment was implemented for the 3-node constant strain triangle (CST) and a standard algorithm...

  9. Shape memory effect alloys

    International Nuclear Information System (INIS)

    Koshimizu, S.

    1992-01-01

    Although the pseudo- or super-elasticity phenomena and the shape memory effect were known since the 1940's, the enormous curiosity and the great interest to their practical applications emerged with the development of the NITINOL alloy (Nickel-Titanium Naval Ordance Laboratory) by the NASA during the 1960's. This fact marked the appearance of a new class of materials, popularly known as shape memory effect alloys (SMEA). The objective of this work is to present a state-of-the-art of the development and applications for the SMEA. (E.O.)

  10. Covering folded shapes

    Directory of Open Access Journals (Sweden)

    Oswin Aichholzer

    2014-05-01

    Full Text Available Can folding a piece of paper flat make it larger? We explore whether a shape S must be scaled to cover a flat-folded copy of itself. We consider both single folds and arbitrary folds (continuous piecewise isometries \\(S\\to\\mathbb{R}^2\\. The underlying problem is motivated by computational origami, and is related to other covering and fixturing problems, such as Lebesgue's universal cover problem and force closure grasps. In addition to considering special shapes (squares, equilateral triangles, polygons and disks, we give upper and lower bounds on scale factors for single folds of convex objects and arbitrary folds of simply connected objects.

  11. Social Shaping of Innovation

    DEFF Research Database (Denmark)

    Buur, Jacob; Mack, Alexandra

    - in particular in a large corporation? This workshop explores how innovation is socially shaped in organizations. Based on our experiences with practices around innovation and collaboration, we start from three proposition about the social shaping of innovation: • Ideas don't thrive as text (i.e. we need...... to consider other media) • Ideas need socialization (ideas are linked to people, we need to be careful about how we support the social innovation context) • Ideas are local (ideas spring out of a local contingency, we need to take care in how we like them to travel)....

  12. Catalogue of fuel elements - 1. addendum October 1958

    International Nuclear Information System (INIS)

    Even, A.

    1957-01-01

    This document contains sheets presenting various characteristics of nuclear fuel elements which are distinguished with respect to their shape: cylinder bar, plate, tube. Each sheet comprises an indication of the atomic pile in which the fuel element is used, dimensions, cartridge data, data related to cooling, to combustion rate, and to fuel handling. A drawing of the fuel element is also given

  13. Collection Development.

    Science.gov (United States)

    School Libraries in Canada, 2002

    2002-01-01

    Includes 21 articles that discuss collection development in Canadian school libraries. Topics include digital collections in school library media centers; print and electronic library resources; library collections; collaborative projects; print-disabled students; informing administrators of the importance of collection development; censorship;…

  14. Shape tuning of adaptive structures for MEMS actuator applications

    Science.gov (United States)

    Ma, Zhichun; Lee, Yung-Cheng

    2005-05-01

    This paper describes a systematic shape tuning procedure of adaptive structures for MEMS actuator applications. Due to fabrication process variations, MEMS devices can have different shapes with varied deflections. Such shape variations should be corrected for specific applications. As a result, it is necessary to establish a shape tuning procedure. Finite element modeling and optimization approach were used to minimize the shape variations. The procedure integrated Python programming, ABAQUS, and optimization algorithm for engineering applications. It used the powerful Python scripts programming, the vast library of ABAQUS functions, and a robust preexisting optimization algorithm, NLPQL, which provides more efficient, flexible, and systematic tools for optimization problems. Optimization was used in the adaptive structural designs and the shape tuning procedure after the assembly. Using this approach, three bimorph, gold-on-polysilicon, samples with different initial shapes were studied for shape tuning. The shape was characterized by maximum tip deflection resulting from thermo-mechanical deformations. The standard deviation of the shape variations was reduced from 1.21 to 0.05 μm after tuning. This reduction was verified by experimental data. Another case with ten devices was studied to confirm the effectiveness of the procedure. The standard deviation of the deflections was reduced from 0.81 to 0.02 μm after tuning. These results demonstrated the effectiveness of the optimum procedure for shape tuning. This general-purpose systematic methodology can be applied to adaptive structures for a variety of aerospace applications.

  15. Trends Shaping Education 2010

    Science.gov (United States)

    OECD Publishing (NJ3), 2010

    2010-01-01

    "Trends Shaping Education 2010" brings together evidence showing the effects on education of globalisation, social challenges, changes in the workplace, the transformation of childhood, and ICT. To make the content accessible, each trend is presented on a double page, containing an introduction, two charts with brief descriptive text and a set of…

  16. Aerodynamically shaped vortex generators

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver; Velte, Clara Marika; Øye, Stig

    2016-01-01

    An aerodynamically shaped vortex generator has been proposed, manufactured and tested in a wind tunnel. The effect on the overall performance when applied on a thick airfoil is an increased lift to drag ratio compared with standard vortex generators. Copyright © 2015 John Wiley & Sons, Ltd....

  17. Shape Up Europe

    DEFF Research Database (Denmark)

    Simovska, Venka; Jensen, Bjarne Bruun

    "Shape Up: a School Community Approach to Influencing the Determinants of Childhood Overweight and Obesity, Lessons Learnt" is a report that aims to provide a synthesis of the project overall evaluation documentation, with a view to systematically review and discuss lessons learnt, and to suggest...

  18. Perceiving animacy from shape.

    Science.gov (United States)

    Schmidt, Filipp; Hegele, Mathias; Fleming, Roland W

    2017-09-01

    Superordinate visual classification-for example, identifying an image as "animal," "plant," or "mineral"-is computationally challenging because radically different items (e.g., "octopus," "dog") must be grouped into a common class ("animal"). It is plausible that learning superordinate categories teaches us not only the membership of particular (familiar) items, but also general features that are shared across class members, aiding us in classifying novel (unfamiliar) items. Here, we investigated visual shape features associated with animate and inanimate classes. One group of participants viewed images of 75 unfamiliar and atypical items and provided separate ratings of how much each image looked like an animal, plant, and mineral. Results show systematic tradeoffs between the ratings, indicating a class-like organization of items. A second group rated each image in terms of 22 midlevel shape features (e.g., "symmetrical," "curved"). The results confirm that superordinate classes are associated with particular shape features (e.g., "animals" generally have high "symmetry" ratings). Moreover, linear discriminant analysis based on the 22-D feature vectors predicts the perceived classes approximately as well as the ground truth classification. This suggests that a generic set of midlevel visual shape features forms the basis for superordinate classification of novel objects along the animacy continuum.

  19. The moon changes shape

    CERN Document Server

    Beaton, Kathryn

    2015-01-01

    "Young children are naturally curious about the world around them. The Moon Changes Shape offers answers to their most compelling questions about the lunar phases. Age-appropriate explanations and appealing photos encourage readers to continue their quest for knowledge. Additional text features and search tools, including a glossary and an index, help students locate information and learn new words."-- Provided by publisher.

  20. Bend me, shape me

    CERN Document Server

    2002-01-01

    A Japanese team has found a way to bend and shape silicon substrates by growing a thin layer of diamond on top. The technique has been proposed as an alternative to mechanical bending, which is currently used to make reflective lenses for X-ray systems and particle physics systems (2 paragraphs).

  1. How life shaped Earth.

    Science.gov (United States)

    Gross, Michael

    2015-10-05

    Earth is much more complex than all the other solar system objects that we know. Thanks to its rich and diverse geology, our planet can offer habitats to a wide range of living species. Emerging insights suggest that this is not just a happy coincidence, but that life itself has in many ways helped to shape the planet.

  2. Characterization and distribution of repetitive elements in association with genes in the human genome.

    Science.gov (United States)

    Liang, Kai-Chiang; Tseng, Joseph T; Tsai, Shaw-Jenq; Sun, H Sunny

    2015-08-01

    Repetitive elements constitute more than 50% of the human genome. Recent studies implied that the complexity of living organisms is not just a direct outcome of a number of coding sequences; the repetitive elements, which do not encode proteins, may also play a significant role. Though scattered studies showed that repetitive elements in the regulatory regions of a gene control gene expression, no systematic survey has been done to report the characterization and distribution of various types of these repetitive elements in the human genome. Sequences from 5' and 3' untranslated regions and upstream and downstream of a gene were downloaded from the Ensembl database. The repetitive elements in the neighboring of each gene were identified and classified using cross-matching implemented in the RepeatMasker. The annotation and distribution of distinct classes of repetitive elements associated with individual gene were collected to characterize genes in association with different types of repetitive elements using systems biology program. We identified a total of 1,068,400 repetitive elements which belong to 37-class families and 1235 subclasses that are associated with 33,761 genes and 57,365 transcripts. In addition, we found that the tandem repeats preferentially locate proximal to the transcription start site (TSS) of genes and the major function of these genes are involved in developmental processes. On the other hand, interspersed repetitive elements showed a tendency to be accumulated at distal region from the TSS and the function of interspersed repeat-containing genes took part in the catabolic/metabolic processes. Results from the distribution analysis were collected and used to construct a gene-based repetitive element database (GBRED; http://www.binfo.ncku.edu.tw/GBRED/index.html). A user-friendly web interface was designed to provide the information of repetitive elements associated with any particular gene(s). This is the first study focusing on the gene

  3. Finite Element Based Formulation of Lattice Boltzmann Equation

    International Nuclear Information System (INIS)

    Jo, Jong Chull; Roh, Kyung Wan; Kwon, Young W.; Kwon, Young W.

    2008-01-01

    The Lattice Boltzmann Method (LBM) has been developed for application to thermal-fluid problems. Recently, the technique was also applied to fluid-structure interaction problems. Most of those studies considered a regular shape of lattice or mesh like square and cubic grids. In order to apply the LBM to more practical cases, it is necessary to be able to solve complex or irregular shapes of problem domains. There have been different kinds of approaches to address the problems. The most common technique was using the finite volume formulation of the lattice Boltzmann equation. Another approach was a point-wise interpolation technique for irregular grids. Other techniques were based on the finite element method. Generally, the finite element method is very powerful for solving two or three-dimensional complex or irregular shapes of domains using the isoparametric element formulation which is based on a mathematical mapping from a regular shape of element in an imaginary domain to a more general and irregular shape of element in the physical domain. In addition, there are variety of choices of finite elements such as triangular or quadrilateral shapes in 2-D, or tetrahedral, triangular prism, or general six-sided solids in 3-D. As a result, the present study presents a new finite element formulation for the lattice Boltzmann equation using the general weighted residual technique. Among the weighted residual formulations, the collocation method, Galerkin method or method of moments are used to develop the finite element based LBM

  4. Collective unconscious: how gut microbes shape human behavior.

    Science.gov (United States)

    Dinan, Timothy G; Stilling, Roman M; Stanton, Catherine; Cryan, John F

    2015-04-01

    The human gut harbors a dynamic and complex microbial ecosystem, consisting of approximately 1 kg of bacteria in the average adult, approximately the weight of the human brain. The evolutionary formation of a complex gut microbiota in mammals has played an important role in enabling brain development and perhaps sophisticated social interaction. Genes within the human gut microbiota, termed the microbiome, significantly outnumber human genes in the body, and are capable of producing a myriad of neuroactive compounds. Gut microbes are part of the unconscious system regulating behavior. Recent investigations indicate that these microbes majorly impact on cognitive function and fundamental behavior patterns, such as social interaction and stress management. In the absence of microbes, underlying neurochemistry is profoundly altered. Studies of gut microbes may play an important role in advancing understanding of disorders of cognitive functioning and social interaction, such as autism. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Understanding the Structure of Large, Diverse Collections of Shapes

    Science.gov (United States)

    2013-06-01

    Scaringella, G. Zoia, and D. Mlynek. Automatic genre classification of music content: a survey. Signal Processing Magazine, IEEE, 23(2):133 –141...Hoffman, David M. Blei, and Perry R. Cook. Content-based musical sim- ilarity computation using the hierarchical dirichlet process. In Juan Pablo...Bello, Elaine Chew, and Douglas Turnbull, editors, ISMIR 2008, 9th International Con- ference on Music Information Retrieval, Drexel University

  6. Locating irregularly shaped clusters of infection intensity

    Directory of Open Access Journals (Sweden)

    Niko Yiannakoulias

    2010-05-01

    Full Text Available Patterns of disease may take on irregular geographic shapes, especially when features of the physical environment influence risk. Identifying these patterns can be important for planning, and also identifying new environmental or social factors associated with high or low risk of illness. Until recently, cluster detection methods were limited in their ability to detect irregular spatial patterns, and limited to finding clusters that were roughly circular in shape. This approach has less power to detect irregularly-shaped, yet important spatial anomalies, particularly at high spatial resolutions. We employ a new method of finding irregularly-shaped spatial clusters at micro-geographical scales using both simulated and real data on Schistosoma mansoni and hookworm infection intensities. This method, which we refer to as the “greedy growth scan”, is a modification of the spatial scan method for cluster detection. Real data are based on samples of hookworm and S. mansoni from Kitengei, Makueni district, Kenya. Our analysis of simulated data shows how methods able to find irregular shapes are more likely to identify clusters along rivers than methods constrained to fixed geometries. Our analysis of infection intensity identifies two small areas within the study region in which infection intensity is elevated, possibly due to local features of the physical or social environment. Collectively, our results show that the “greedy growth scan” is a suitable method for exploratory geographical analysis of infection intensity data when irregular shapes are suspected, especially at micro-geographical scales.

  7. Duality based contact shape optimization

    DEFF Research Database (Denmark)

    Vondrák, Vít; Dostal, Zdenek; Rasmussen, John

    2001-01-01

    An implementation of semi-analytic method for the sensitivity analysis in contact shape optimization without friction is described. This method is then applied to the contact shape optimization.......An implementation of semi-analytic method for the sensitivity analysis in contact shape optimization without friction is described. This method is then applied to the contact shape optimization....

  8. Locating irregularly shaped clusters of infection intensity

    DEFF Research Database (Denmark)

    Yiannakoulias, Niko; Wilson, Shona; Kariuki, H. Curtis

    2010-01-01

    . We employ a new method of finding irregularly-shaped spatial clusters at micro-geographical scales using both simulated and real data on Schistosoma mansoni and hookworm infection intensities. This method, which we refer to as the "greedy growth scan", is a modification of the spatial scan method...... of infection intensity identifies two small areas within the study region in which infection intensity is elevated, possibly due to local features of the physical or social environment. Collectively, our results show that the "greedy growth scan" is a suitable method for exploratory geographical analysis...... of infection intensity data when irregular shapes are suspected, especially at micro-geographical scales....

  9. Nanoparticle shape, thermodynamics and kinetics

    International Nuclear Information System (INIS)

    Marks, L D; Peng, L

    2016-01-01

    Nanoparticles can be beautiful, as in stained glass windows, or they can be ugly as in wear and corrosion debris from implants. We estimate that there will be about 70 000 papers in 2015 with nanoparticles as a keyword, but only one in thirteen uses the nanoparticle shape as an additional keyword and research focus, and only one in two hundred has thermodynamics. Methods for synthesizing nanoparticles have exploded over the last decade, but our understanding of how and why they take their forms has not progressed as fast. This topical review attempts to take a critical snapshot of the current understanding, focusing more on methods to predict than a purely synthetic or descriptive approach. We look at models and themes which are largely independent of the exact synthetic method whether it is deposition, gas-phase condensation, solution based or hydrothermal synthesis. Elements are old dating back to the beginning of the 20th century—some of the pioneering models developed then are still relevant today. Others are newer, a merging of older concepts such as kinetic-Wulff constructions with methods to understand minimum energy shapes for particles with twins. Overall we find that while there are still many unknowns, the broad framework of understanding and predicting the structure of nanoparticles via diverse Wulff constructions, either thermodynamic, local minima or kinetic has been exceedingly successful. However, the field is still developing and there remain many unknowns and new avenues for research, a few of these being suggested towards the end of the review. (topical review)

  10. Nanoparticle shape, thermodynamics and kinetics

    Science.gov (United States)

    Marks, L. D.; Peng, L.

    2016-02-01

    Nanoparticles can be beautiful, as in stained glass windows, or they can be ugly as in wear and corrosion debris from implants. We estimate that there will be about 70 000 papers in 2015 with nanoparticles as a keyword, but only one in thirteen uses the nanoparticle shape as an additional keyword and research focus, and only one in two hundred has thermodynamics. Methods for synthesizing nanoparticles have exploded over the last decade, but our understanding of how and why they take their forms has not progressed as fast. This topical review attempts to take a critical snapshot of the current understanding, focusing more on methods to predict than a purely synthetic or descriptive approach. We look at models and themes which are largely independent of the exact synthetic method whether it is deposition, gas-phase condensation, solution based or hydrothermal synthesis. Elements are old dating back to the beginning of the 20th century—some of the pioneering models developed then are still relevant today. Others are newer, a merging of older concepts such as kinetic-Wulff constructions with methods to understand minimum energy shapes for particles with twins. Overall we find that while there are still many unknowns, the broad framework of understanding and predicting the structure of nanoparticles via diverse Wulff constructions, either thermodynamic, local minima or kinetic has been exceedingly successful. However, the field is still developing and there remain many unknowns and new avenues for research, a few of these being suggested towards the end of the review.

  11. Biomedical Shape Memory Polymers

    Directory of Open Access Journals (Sweden)

    SHEN Xue-lin

    2017-07-01

    Full Text Available Shape memory polymers(SMPs are a class of functional "smart" materials that have shown bright prospects in the area of biomedical applications. The novel smart materials with multifunction of biodegradability and biocompatibility can be designed based on their general principle, composition and structure. In this review, the latest process of three typical biodegradable SMPs(poly(lactide acide, poly(ε-caprolactone, polyurethane was summarized. These three SMPs were classified in different structures and discussed, and shape-memory mechanism, recovery rate and fixed rate, response speed was analysed in detail, also, some biomedical applications were presented. Finally, the future development and applications of SMPs are prospected: two-way SMPs and body temperature induced SMPs will be the focus attension by researchers.

  12. Equilibrium-Based Nonhomogeneous Anisotropic Beam Element

    DEFF Research Database (Denmark)

    Krenk, Steen; Couturier, Philippe

    2017-01-01

    The stiffness matrix and the nodal forces associated with distributed loads are obtained for a nonhomogeneous anisotropic elastic beam element by the use of complementary energy. The element flexibility matrix is obtained by integrating the complementary-energy density corresponding to six beam...... equilibrium states, and then inverted and expanded to provide the element-stiffness matrix. Distributed element loads are represented via corresponding internal-force distributions in local equilibrium with the loads. The element formulation does not depend on assumed shape functions and can, in principle......, include any variation of cross-sectional properties and load variation, provided that these are integrated with sufficient accuracy in the process. The ability to represent variable cross-sectional properties, coupling from anisotropic materials, and distributed element loads is illustrated by numerical...

  13. Antiferroelectric Shape Memory Ceramics

    Directory of Open Access Journals (Sweden)

    Kenji Uchino

    2016-05-01

    Full Text Available Antiferroelectrics (AFE can exhibit a “shape memory function controllable by electric field”, with huge isotropic volumetric expansion (0.26% associated with the AFE to Ferroelectric (FE phase transformation. Small inverse electric field application can realize the original AFE phase. The response speed is quick (2.5 ms. In the Pb0.99Nb0.02[(Zr0.6Sn0.41-yTiy]0.98O3 (PNZST system, the shape memory function is observed in the intermediate range between high temperature AFE and low temperature FE, or low Ti-concentration AFE and high Ti-concentration FE in the composition. In the AFE multilayer actuators (MLAs, the crack is initiated in the center of a pair of internal electrodes under cyclic electric field, rather than the edge area of the internal electrodes in normal piezoelectric MLAs. The two-sublattice polarization coupling model is proposed to explain: (1 isotropic volume expansion during the AFE-FE transformation; and (2 piezoelectric anisotropy. We introduce latching relays and mechanical clampers as possible unique applications of shape memory ceramics.

  14. Reversible Shaping of Microwells by Polarized Light Irradiation

    Directory of Open Access Journals (Sweden)

    Federica Pirani

    2017-01-01

    Full Text Available In the last years, stimuli-responsive polymeric materials have attracted great interest, due to their low cost and ease of structuration over large areas combined with the possibility to actively manipulate their properties. In this work, we propose a polymeric pattern of soft-imprinted microwells containing azobenzene molecules. The shape of individual elements of the pattern can be controlled after fabrication by irradiation with properly polarized light. By taking advantage of the light responsivity of the azobenzene compound, we demonstrate the possibility to reversibly modulate a contraction-expansion of wells from an initial round shape to very narrow slits. We also show that the initial shape of the microconcavities can be restored by flipping the polarization by 90°. The possibility to reversibly control the final shape of individual elements of structured surfaces offers the opportunity to engineer surface properties dynamically, thus opening new perspectives for several applications.

  15. An Abaqus UEL implementation of the smoothed finite element method

    OpenAIRE

    Kumbhar, Pramod Y; Francis, Amrita; Swaminathan, Narasimhan; Annabattula, Ratna Kumar; Natarajan, Sundararajan

    2017-01-01

    In this paper, we discuss the implementation of a cell based smoothed finite element method (CSFEM) within the commercial finite element software Abaqus. The salient feature of the CSFEM is that it does not require an explicit form of the derivative of the shape functions and there is no isoparametric mapping. This implementation is accomplished by employing the user element subroutine (UEL) feature of the software. The details on the input data format together with the proposed user element ...

  16. Characterization and design of antagonistic shape memory alloy actuators

    International Nuclear Information System (INIS)

    Georges, T; Brailovski, V; Terriault, P

    2012-01-01

    Antagonistic shape memory actuators use opposing shape memory alloy (SMA) elements to create devices capable of producing differential motion paths and two-way mechanical work in a very efficient manner. There is no requirement for additional bias elements to ‘re-arm’ the actuators and allow repetitive actuation. The work generation potential of antagonistic shape memory actuators is determined by specific SMA element characteristics and their assembly conditions. In this study, the selected SMA wires are assembled in antagonistic configuration and characterized using a dedicated test bench to evaluate their stress–strain characteristics as a function of the number of cycles. Using these functional characteristics, a so-called ‘working envelope’ is built to assist in the design of such an actuator. Finally, the test bench is used to simulate a real application of an antagonistic actuator (case study). (paper)

  17. A study on human hair element content as monitor for trace elements pollution in Eg

    International Nuclear Information System (INIS)

    Tadros, N.; Metwally, E.

    2004-01-01

    Trace element content in human is a suitable indicator of exposure to trace element pollutants. Concentration levels of 12 trace elements in human head hair samples collected from more than 23 individuals have been determined. The collected hair samples were classified into four groups collected from workers at nuclear research center and others far away from the center. Neutron activation analysis technique was used in the preset study. The data reported for trace elements content in different hair samples were discussed. Significant differences were observed for several elements levels. comparative studies demonstrated that the concentration of some elements in hair of exposed workers, are greater than those corresponding to non exposed workers. Also, there was no clear significant correlation between the elements content of different hair samples and the age of the donors

  18. Shape evolution of a melting nonspherical particle.

    Science.gov (United States)

    Kintea, Daniel M; Hauk, Tobias; Roisman, Ilia V; Tropea, Cameron

    2015-09-01

    In this study melting of irregular ice crystals was observed in an acoustic levitator. The evolution of the particle shape is captured using a high-speed video system. Several typical phenomena have been discovered: change of the particle shape, appearance of a capillary flow of the melted liquid on the particle surface leading to liquid collection at the particle midsection (where the interface curvature is smallest), and appearance of sharp cusps at the particle tips. No such phenomena can be observed during melting of spherical particles. An approximate theoretical model is developed which accounts for the main physical phenomena associated with melting of an irregular particle. The agreement between the theoretical predictions for the melting time, for the evolution of the particle shape, and the corresponding experimental data is rather good.

  19. Shape space exploration of constrained meshes

    KAUST Repository

    Yang, Yongliang

    2011-12-12

    We present a general computational framework to locally characterize any shape space of meshes implicitly prescribed by a collection of non-linear constraints. We computationally access such manifolds, typically of high dimension and co-dimension, through first and second order approximants, namely tangent spaces and quadratically parameterized osculant surfaces. Exploration and navigation of desirable subspaces of the shape space with regard to application specific quality measures are enabled using approximants that are intrinsic to the underlying manifold and directly computable in the parameter space of the osculant surface. We demonstrate our framework on shape spaces of planar quad (PQ) meshes, where each mesh face is constrained to be (nearly) planar, and circular meshes, where each face has a circumcircle. We evaluate our framework for navigation and design exploration on a variety of inputs, while keeping context specific properties such as fairness, proximity to a reference surface, etc. © 2011 ACM.

  20. Collection Mapping and Collection Development.

    Science.gov (United States)

    Murray, William; And Others

    1985-01-01

    Describes the use of collection mapping to assess media collections of Aurora, Colorado, Public Schools. Case studies of elementary, middle, and high school media centers describe materials selection and weeding and identify philosophies that library collections should support school curriculum, and teacher-library media specialist cooperation in…

  1. Virtual and smoothed finite elements: A connection and its application to polygonal/polyhedral finite element methods

    OpenAIRE

    Natarajan, Sundararajan; Bordas, Stéphane; Ooi, Ean Tat

    2015-01-01

    We show both theoretically and numerically a connection between the smoothed finite element method (SFEM) and the virtual element method and use this approach to derive stable, cheap and optimally convergent polyhedral FEM.We show that the stiffness matrix computed with one subcell SFEM is identical to the consistency term of the virtual element method, irrespective of the topology of the element, as long as the shape functions vary linearly on the boundary. Using this connection, we propose ...

  2. Trace elements in blood collected from birds feeding in the area around Doñana National Park affected by the toxic spill from the Aznacóllar mine.

    Science.gov (United States)

    Benito, V; Devesa, V; Muñoz, O; Suñer, M A; Montoro, R; Baos, R; Hiraldo, F; Ferrer, M; Fernández, M; González, M J

    1999-12-06

    A long-term monitoring plan was established to study if bird populations around Doñana National Park were affected by the toxic spill from the Aznalcóllar mine. The concentrations of Zn, Pb, As, Cu, Sb, Co, Tl and Cd in the blood of 11 bird species feeding in the area were determined. The parameters which most affect the accumulation of trace elements in the birds studied are, firstly, species and secondly, trophic position, sex, days of exposure and weight. In some individuals, Zn and Cu occurred at higher levels than the reference values for contaminated areas. Concentrations of Pb and Cd in a considerable number of individuals were higher than those found in birds from uncontaminated areas. The present data, together with the lack of data on blood metal concentration prior to the spill, do not offer any conclusive evidence of the influence of the spill on avian blood metal concentrations.

  3. Wedding ring shaped excitation coil

    Science.gov (United States)

    MacLennan, Donald A.; Tsai, Peter

    2001-01-01

    A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and/or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency.

  4. Evolution of collectivity in nuclei

    International Nuclear Information System (INIS)

    Muralithar, S.

    2016-01-01

    Nuclear structure studies provide opportunity to understand various modes of excitations and shapes of nucleus as a function of angular momentum, excitation energy and iso-spin. Single particle and collective excitations keep competing and give rise to interesting structures. Phenomena namely back bending, band termination, shape co-existence, rotational bands with different configurations and octupole correlation were reported using gamma ray spectroscopy method. Above nuclear phenomena were studied using Gamma detector array (GDA), Plunger, Heavy Ion Recoil Analyser GDA, Indian National Gamma Array - HlRA at IUAC by various users. Some examples of evolution of collectivity in nuclear structure studies carried out will be presented. (author)

  5. Oriented active shape models.

    Science.gov (United States)

    Liu, Jiamin; Udupa, Jayaram K

    2009-04-01

    Active shape models (ASM) are widely employed for recognizing anatomic structures and for delineating them in medical images. In this paper, a novel strategy called oriented active shape models (OASM) is presented in an attempt to overcome the following five limitations of ASM: 1) lower delineation accuracy, 2) the requirement of a large number of landmarks, 3) sensitivity to search range, 4) sensitivity to initialization, and 5) inability to fully exploit the specific information present in the given image to be segmented. OASM effectively combines the rich statistical shape information embodied in ASM with the boundary orientedness property and the globally optimal delineation capability of the live wire methodology of boundary segmentation. The latter characteristics allow live wire to effectively separate an object boundary from other nonobject boundaries with similar properties especially when they come very close in the image domain. The approach leads to a two-level dynamic programming method, wherein the first level corresponds to boundary recognition and the second level corresponds to boundary delineation, and to an effective automatic initialization method. The method outputs a globally optimal boundary that agrees with the shape model if the recognition step is successful in bringing the model close to the boundary in the image. Extensive evaluation experiments have been conducted by utilizing 40 image (magnetic resonance and computed tomography) data sets in each of five different application areas for segmenting breast, liver, bones of the foot, and cervical vertebrae of the spine. Comparisons are made between OASM and ASM based on precision, accuracy, and efficiency of segmentation. Accuracy is assessed using both region-based false positive and false negative measures and boundary-based distance measures. The results indicate the following: 1) The accuracy of segmentation via OASM is considerably better than that of ASM; 2) The number of landmarks

  6. Shaping 3-D boxes

    DEFF Research Database (Denmark)

    Stenholt, Rasmus; Madsen, Claus B.

    2011-01-01

    Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data......F) docking experiment against an existing technique, which requires the user to perform the rotation and scaling of the box explicitly. The precision of the users' box construction is evaluated by a novel error metric measuring the difference between two boxes. The results of the experiment strongly indicate...

  7. Nonstationary temperature field in the fuel element

    International Nuclear Information System (INIS)

    Vehauc, A.; Spasojevic, D.

    1970-03-01

    Nonstationary temperature field in the fuel element was examined for spatial and time distribution of the specific power generated in the fuel element. Analytical method was developed for calculating the temperature variation in the fuel element of a nuclear reactor for a typical shape of the heat generation function. The method is based on series expansion of the temperature field by self functions and application of Laplace transformation in time coordinate. For numerical calculation of the temperature distribution a computer code was developed based on the proposed method and applied on the ZUSE-Z-23 computer [sr

  8. Spacer grid for fuel elements

    International Nuclear Information System (INIS)

    Hensolt, T.; Huenner, M.; Rau, P.; Veca, A.

    1978-01-01

    The spacer grid for fuel elements of a gas-cooled fast breeder reactor (but also for PWRs and BWRs) consists of a lattice field with dodecagonal meshes. These meshes are formed by three each adjacent hexagons grouped arround a central axis. The pairs of legs extending into the dodecagon and being staggered by 120 0 are designed as knubs with inclined abutting surfaces for the fuel rods. By this means there is formed a three-point bearing for centering the fuel rods. The spacer grid mentioned above is rough-worked from a single disc- resp. plate-shaped body (unfinished piece). (DG) [de

  9. Spacer grid for fuel elements

    International Nuclear Information System (INIS)

    Hensolt, T.; Huenner, M.; Rau, P.; Veca, A.

    1980-01-01

    The spacer grid for fuel elements of a gas-cooled fast breeder reactor (but also for PWRs and BWRs) consists of a lattice field with dodecagonal meshes. These meshes are formed by three each adjacent hexagons grouped arround a central axis. The pairs of legs extending into the dodecagon and being staggered by 120 are designed as knubs with inclined abutting surfaces for the fuel rods. By this means there is formed a three-point bearing for centering the fuel rods. The spacer grid mentioned above is rough-worked from a single disc- resp. plate-shaped body (unfinished piece). (orig.)

  10. Shell shape as a biomarker of marine pollution historic increase.

    Science.gov (United States)

    Márquez, F; Primost, M A; Bigatti, G

    2017-01-30

    Buccinanops globulosus is a TBT sensitive marine gastropod, classified as a good indicator of imposex incidence and used as a model to study adverse contamination effects. Population and maritime industries has incremented pollution in Nuevo gulf harbor since 1970s, promoting morphological changes in B. globulosus shell shape. We study the shell shape of the species comparing present day's specimens from the harbor zone with those collected in the same zone before the increasing of maritime activity and pre-Hispanic archaeological Middens. We demonstrated that harbor pollution produces globular shell shape in B. globulosus, an effect that probably allows gastropods to isolate themselves from the external adverse environment. On the contrary, shells from pre-Hispanic periods, unpolluted sites and those collected before the expansion of maritime activities, presented an elongated shell shape. Our study confirms that shell shape variation in marine gastropods can be used as a biomarker of harbor pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Mast Wake Reduction by Shaping

    National Research Council Canada - National Science Library

    Beauchamp, Charles H

    2005-01-01

    The present invention relates to various mast shapes, in which the mast shapes minimize the production of visible, electro-optic, infrared and radar cross section wake signatures produced by water surface piercing masts...

  12. Pairwise harmonics for shape analysis

    KAUST Repository

    Zheng, Youyi

    2013-07-01

    This paper introduces a simple yet effective shape analysis mechanism for geometry processing. Unlike traditional shape analysis techniques which compute descriptors per surface point up to certain neighborhoods, we introduce a shape analysis framework in which the descriptors are based on pairs of surface points. Such a pairwise analysis approach leads to a new class of shape descriptors that are more global, discriminative, and can effectively capture the variations in the underlying geometry. Specifically, we introduce new shape descriptors based on the isocurves of harmonic functions whose global maximum and minimum occur at the point pair. We show that these shape descriptors can infer shape structures and consistently lead to simpler and more efficient algorithms than the state-of-the-art methods for three applications: intrinsic reflectional symmetry axis computation, matching shape extremities, and simultaneous surface segmentation and skeletonization. © 2012 IEEE.

  13. Critical state in disk-shaped superconductors

    Science.gov (United States)

    Däumling, M.; Larbalestier, D. C.

    1989-11-01

    We have calculated the magnetic fields and currents occurring in a disk-shaped superconductor (radius >>thickness) in the critical state in a self-consistent way using finite-element analysis. We find that the field shielded (or trapped) in the center of the disk is roughly equal to Jcd, where d is the thickness of the disk. The shielding currents also create radial fields which are or order Jcd/2 on the disk surface. For low applied fields Happltelsa applied field. The field dependence of the calculated magnetic moment in the self-field dominated regime is independent of whether Jc is weakly or strongly (~1/H) dependent on field. The calculations were validated by comparison to both magnetic and resistive measurements on a disk-shaped section in Nb3Sn tape.

  14. Technical Note: A novel rocket-based in situ collection technique for mesospheric and stratospheric aerosol particles

    Directory of Open Access Journals (Sweden)

    W. Reid

    2013-03-01

    Full Text Available A technique for collecting aerosol particles between altitudes of 17 and 85 km is described. Spin-stabilized collection probes are ejected from a sounding rocket allowing for multi-point measurements. Each probe is equipped with 110 collection samples that are 3 mm in diameter. The collection samples are one of three types: standard transmission electron microscopy carbon grids, glass fibre filter paper or silicone gel. Collection samples are exposed over a 50 m to 5 km height range with a total of 45 separate ranges. Post-flight electron microscopy will give size-resolved information on particle number, shape and elemental composition. Each collection probe is equipped with a suite of sensors to capture the probe's status during the fall. Parachute recovery systems along with GPS-based localization will ensure that each probe can be located and recovered for post-flight analysis.

  15. Shape of the growing front of biofilms

    Science.gov (United States)

    Wang, Xin; Stone, Howard A.; Golestanian, Ramin

    2017-12-01

    The spatial organization of bacteria in dense biofilms is key to their collective behaviour, and understanding it will be important for medical and technological applications. Here we study the morphology of a compact biofilm that undergoes unidirectional growth, and determine the condition for the stability of the growing interface as a function of the nutrient concentration and mechanical tension. Our study suggests that transient behaviour may play an important role in shaping the structure of a biofilm.

  16. Mismatch-Shaped Pseudo-Passive Two-Capacitor DAC

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper; Moon, Un-Ku; Temes, Gabor C.

    1999-01-01

    interpolation filter, but arbitrary properties of the overall interpolation characteristic can be assured.Simulations indicate that the scheme can be used for the realization of DACs with 16-bit linearity and SNR performance, with only 0.1% capacitance accuracy. The DAC is pseudo-passive, i.e. an active element......A simple mismatch-shaping scheme is proposed for a two-capacitor DAC. Unlike in other mismatch-shaping systems, the shaped error is generated by direct filtering of a well-defined bounded signal, which can be generated as white noise. The operation is closely related to a specific digital...

  17. On the approximation of crack shapes found during inservice inspection

    Energy Technology Data Exchange (ETDEWEB)

    Bhate, S.R.; Chawla, D.S.; Kushwaha, H.S. [Bhabha Atomic Research Centre, Bombay (India)] [and others

    1997-04-01

    This paper addresses the characterization of axial internal flaw found during inservice inspection of a pipe. J-integral distribution for various flaw shapes is obtained using line spring finite, element method. The peak J-value and its distribution across the crack is found to be characteristic feature of each shape. The triangular shape yields peak J-value away from the center, the point of depth. The elliptic approximation results in large overestimate of J-value for unsymmetric flaws. Triangular approximation is recommended for such flaws so that further service can be obtained from the component.

  18. On the approximation of crack shapes found during inservice inspection

    International Nuclear Information System (INIS)

    Bhate, S.R.; Chawla, D.S.; Kushwaha, H.S.

    1997-01-01

    This paper addresses the characterization of axial internal flaw found during inservice inspection of a pipe. J-integral distribution for various flaw shapes is obtained using line spring finite, element method. The peak J-value and its distribution across the crack is found to be characteristic feature of each shape. The triangular shape yields peak J-value away from the center, the point of depth. The elliptic approximation results in large overestimate of J-value for unsymmetric flaws. Triangular approximation is recommended for such flaws so that further service can be obtained from the component

  19. Membership Functions for Fuzzy Focal Elements

    Directory of Open Access Journals (Sweden)

    Porębski Sebastian

    2016-09-01

    Full Text Available The paper presents a study on data-driven diagnostic rules, which are easy to interpret by human experts. To this end, the Dempster-Shafer theory extended for fuzzy focal elements is used. Premises of the rules (fuzzy focal elements are provided by membership functions which shapes are changing according to input symptoms. The main aim of the present study is to evaluate common membership function shapes and to introduce a rule elimination algorithm. Proposed methods are first illustrated with the popular Iris data set. Next experiments with five medical benchmark databases are performed. Results of the experiments show that various membership function shapes provide different inference efficiency but the extracted rule sets are close to each other. Thus indications for determining rules with possible heuristic interpretation can be formulated.

  20. Mean gust shapes

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G.C.; Bierbooms, W.; Hansen, K.S.

    2003-12-01

    The gust events described in the IEC-standard are formulated as coherent gusts of an inherent deterministic character, whereas the gusts experienced in real situation are of a stochastic nature with a limited spatial extension. This conceptual difference may cause substantial differences in the load patterns of a wind turbine when a gust event is imposed. Methods exist to embed a gust of a prescribed appearance in a stochastic wind field. The present report deals with a method to derive realistic gust shapes based only on a few stochastic features of the relevant turbulence field. The investigation is limited to investigation of the longitudinal turbulence component, and consequently no attention is paid to wind direction gusts. A theoretical expression, based on level crossing statistics, is proposed for the description of a mean wind speed gust shape. The description also allows for information on the spatial structure of the wind speed gust and relies only on conventional wind field parameters. The theoretical expression is verified by comparison with simulated wind fields as well as with measured wind fields covering a broad range of mean wind speed situations and terrain conditions. The work reported makes part of the project 'Modelling of Extreme Gusts for Design Calculations' (NEWGUST), which is co-funded through JOULEIII on contract no. JOR3-CT98-0239. (au)

  1. Flexible shaping: how learning in small steps helps.

    Science.gov (United States)

    Krueger, Kai A; Dayan, Peter

    2009-03-01

    Humans and animals can perform much more complex tasks than they can acquire using pure trial and error learning. This gap is filled by teaching. One important method of instruction is shaping, in which a teacher decomposes a complete task into sub-components, thereby providing an easier path to learning. Despite its importance, shaping has not been substantially studied in the context of computational modeling of cognitive learning. Here we study the shaping of a hierarchical working memory task using an abstract neural network model as the target learner. Shaping significantly boosts the speed of acquisition of the task compared with conventional training, to a degree that increases with the temporal complexity of the task. Further, it leads to internal representations that are more robust to task manipulations such as reversals. We use the model to investigate some of the elements of successful shaping.

  2. Generative collectives

    NARCIS (Netherlands)

    van Osch, W.; Avital, M.; Sabherwal, R.; Sumner, M.

    2010-01-01

    Analyzing generative group activities against the backdrop of an increasingly connected world, this theory development paper introduces the concept of "generative collectives" as a new framework for classifying internet-based collectives and a novel theoretical lens for explaining why some

  3. Jay's Collectibles

    Science.gov (United States)

    Cappel, James J.; Gillman, Jason R., Jr.

    2011-01-01

    There is growing interest in collectibles of many types, as indicated by the popularity of television programs such as the History Channel's "Pawn Stars" and "American Pickers" and the Public Broadcasting Service's "Antiques Road Show." The availability of online auction sites such as eBay has enabled many people to collect items of interest as a…

  4. Data collection

    NARCIS (Netherlands)

    Callaert, J.; Epping, Elisabeth; Federkeil, G.; Jongbloed, Benjamin W.A.; Kaiser, Franciscus; Tijssen, R.; van Vught, F.A.; Ziegele, F.

    2012-01-01

    This chapter describes the data collection instruments used in the development of U-Multirank. The first section is an overview of existing databases – mainly on bibliometrics and patents. The second describes the questionnaires and survey tools used for collecting data from the institutions – at

  5. Performance-based shape optimization of continuum structures

    International Nuclear Information System (INIS)

    Liang Qingquan

    2010-01-01

    This paper presents a performance-based optimization (PBO) method for optimal shape design of continuum structures with stiffness constraints. Performance-based design concepts are incorporated in the shape optimization theory to achieve optimal designs. In the PBO method, the traditional shape optimization problem of minimizing the weight of a continuum structure with displacement or mean compliance constraints is transformed to the problem of maximizing the performance of the structure. The optimal shape of a continuum structure is obtained by gradually eliminating inefficient finite elements from the structure until its performance is maximized. Performance indices are employed to monitor the performance of optimized shapes in an optimization process. Performance-based optimality criteria are incorporated in the PBO method to identify the optimum from the optimization process. The PBO method is used to produce optimal shapes of plane stress continuum structures and plates in bending. Benchmark numerical results are provided to demonstrate the effectiveness of the PBO method for generating the maximum stiffness shape design of continuum structures. It is shown that the PBO method developed overcomes the limitations of traditional shape optimization methods in optimal design of continuum structures. Performance-based optimality criteria presented can be incorporated in any shape and topology optimization methods to obtain optimal designs of continuum structures.

  6. Control volume finite element method with multidimensional edge element Scharfetter-Gummel upwinding. Part 1, formulation.

    Energy Technology Data Exchange (ETDEWEB)

    Bochev, Pavel Blagoveston

    2011-06-01

    We develop a new formulation of the Control Volume Finite Element Method (CVFEM) with a multidimensional Scharfetter-Gummel (SG) upwinding for the drift-diffusion equations. The formulation uses standard nodal elements for the concentrations and expands the flux in terms of the lowest-order Nedelec H(curl; {Omega})-compatible finite element basis. The SG formula is applied to the edges of the elements to express the Nedelec element degree of freedom on this edge in terms of the nodal degrees of freedom associated with the endpoints of the edge. The resulting upwind flux incorporates the upwind effects from all edges and is defined at the interior of the element. This allows for accurate evaluation of integrals on the boundaries of the control volumes for arbitrary quadrilateral elements. The new formulation admits efficient implementation through a standard loop over the elements in the mesh followed by loops over the element nodes (associated with control volume fractions in the element) and element edges (associated with flux degrees of freedom). The quantities required for the SG formula can be precomputed and stored for each edge in the mesh for additional efficiency gains. For clarity the details are presented for two-dimensional quadrilateral grids. Extension to other element shapes and three dimensions is straightforward.

  7. Ferromagnetic shape memory materials

    Science.gov (United States)

    Tickle, Robert Jay

    Ferromagnetic shape memory materials are a new class of active materials which combine the properties of ferromagnetism with those of a diffusionless, reversible martensitic transformation. These materials have been the subject of recent study due to the unusually large magnetostriction exhibited in the martensitic phase. In this thesis we report the results of experiments which characterize the magnetic and magnetomechanical properties of both austenitic and martensitic phases of ferromagnetic shape memory material Ni2MnGa. In the high temperature cubic phase, anisotropy and magnetostriction constants are determined for a range of temperatures from 50°C down to the transformation temperature, with room temperature values of K1 = 2.7 +/- 104 ergs/cm3 and lambda100 = -145 muepsilon. In the low temperature tetragonal phase, the phenomenon of field-induced variant rearrangement is shown to produce anomalous results when traditional techniques for determining anisotropy and magnetostriction properties are employed. The requirement of single variant specimen microstructure is explained, and experiments performed on such a specimen confirm a uniaxial anisotropy within each martensitic variant with anisotropy constant Ku = 2.45 x 106 ergs/cm3 and a magnetostriction constant of lambdasv = -288 +/- 73 muepsilon. A series of magnetomechanical experiments investigate the effects of microstructure bias, repeated field cycling, varying field ramp rate, applied load, and specimen geometry on the variant rearrangement phenomenon in the martensitic phase. In general, the field-induced strain is found to be a function of the variant microstructure. Experiments in which the initial microstructure is biased towards a single variant state with an applied load generate one-time strains of 4.3%, while those performed with a constant bias stress of 5 MPa generate reversible strains of 0.5% over a period of 50 cycles. An increase in the applied field ramp rate is shown to reduce the

  8. Culture collections.

    Science.gov (United States)

    Smith, David

    2012-01-01

    Culture collections no matter their size, form, or institutional objectives play a role in underpinning microbiology, supplying the resources for study, innovation, and discovery. Their basic roles include providing a mechanism for ex situ conservation of organisms; they are repositories for strains subject to publication, taking in safe, confidential, and patent deposits from researchers. They supply strains for use; therefore, the microorganisms provided must be authentic and preserved well, and any associated information must be valid and sufficient to facilitate the confirmation of their identity and to facilitate their use. The organisms must be collected in compliance with international conventions, international and national legislation and distributed to users indicating clearly the terms and conditions under which they are received and can be used. Collections are harmonizing approaches and characterizing strains to meet user needs. No one single collection can carry out this task alone, and therefore, it is important that output and strategy are coordinated to ensure culture collections deliver the basic resources and services microbiological innovation requires. This chapter describes the types of collection and how they can implement quality management systems and operate to deliver their basic functions. The links to information sources given not only provide support for the practitioners within collections but also provide guidance to users on accessing the huge resource available and how they can help ensure microbiology has the resources and a solid platform for future development. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Numerical Prediction of Springback Shape of Severely Bent Sheet Metal

    International Nuclear Information System (INIS)

    Iwata, Noritoshi; Murata, Atsunobu; Yogo, Yasuhiro; Tsutamori, Hideo; Niihara, Masatomo; Ishikura, Hiroshi; Umezu, Yasuyoshi

    2007-01-01

    In the sheet metal forming simulation, the shell element widely used is assumed as a plane stress state based on the Mindlin-Reissner theory. Numerical prediction with the conventional shell element is not accurate when the bending radius is small compared to the sheet thickness. The main reason is because the strain and stress formulation of the conventional shell element does not fit the actual phenomenon. In order to predict precisely the springback of a bent sheet with a severe bend, a measurement method for through-thickness strain has been proposed. The strain was formulated based on measurement results and calculation results from solid element. Through-thickness stress distribution was formulated based on the equilibrium. The proposed shell element based on the formulations was newly introduced into the FEM code. The accuracy of this method's prediction of the springback shape of two bent processes has been confirmed. As a result, it was found that the springback shape even in severe bending can be predicted with high accuracy. Moreover, the calculation time in the proposed shell element is about twice that in the conventional shell element, and has been shortened to about 1/20 compared to a solid element

  10. Shape memory heat engines

    Science.gov (United States)

    Salzbrenner, R.

    1984-06-01

    The mechanical shape memory effect associated with a thermoelastic martensitic transformation can be used to convert heat directly into mechanical work. Laboratory simulation of two types of heat engine cycles (Stirling and Ericsson) has been performed to measure the amount of work available/cycle in a Ni-45 at. pct Ti alloy. Tensile deformations at ambient temperature induced martensite, while a subsequent increase in temperature caused a reversion to the parent phase during which a load was carried through the strain recovery (i.e., work was accomplished). The amount of heat necessary to carry the engines through a cycle was estimated from calorimeter measurements and the work performed/cycle. The measured efficiency of the system tested reached a maximum of 1.4 percent, which was well below the theoretical (Carnot) maximum efficiency of 35.6 percent.

  11. Shape Bonding method

    Science.gov (United States)

    Pontius, James T. (Inventor)

    2010-01-01

    The present invention is directed to a method of bonding at least two surfaces together. The methods step of the present invention include applying a strip of adhesive to a first surface along a predefined outer boundary of a bond area and thereby defining a remaining open area there within. A second surface, or gusset plate, is affixed onto the adhesive before the adhesive cures. The strip of adhesive is allowed to cure and then a second amount of adhesive is applied to cover the remaining open area and substantially fill a void between said first and second surfaces about said bond area. A stencil may be used to precisely apply the strip of adhesive. When the strip cures, it acts as a dam to prevent overflow of the subsequent application of adhesive to undesired areas. The method results in a precise bond area free of undesired shapes and of a preferred profile which eliminate the drawbacks of the prior art bonds.

  12. Boosted Higgs Shapes

    CERN Document Server

    Schlaffer, Matthias; Takeuchi, Michihisa; Weiler, Andreas; Wymant, Chris

    2014-01-01

    The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of $H\\to 2\\ell+\\mathbf{p}\\!\\!/_T$ via $H\\to \\tau\\tau$ and $H\\to WW^*$ could be performed and demonstrate that it offers a compelling alternative to the $t\\bar t H$ channel. We discuss the sensitivity to new physics in the most challenging scenario of an exactly SM-like inclusive Higgs cross-section.

  13. Digital pulse shape discrimination

    International Nuclear Information System (INIS)

    Miller, L. F.; Preston, J.; Pozzi, S.; Flaska, M.; Neal, J.

    2007-01-01

    Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rather than the traditional, and well-established, analogous techniques. One issue that complicates PSD for neutrons in mixed fields is that the light output characteristics of typical scintillators available for PSD, such as BC501A, vary as a function of energy deposited in the detector. This behaviour is more easily accommodated with digital processing of signals than with analogous signal processing. Results illustrate the effectiveness of digital PSD. (authors)

  14. Audiovisual correspondence between musical timbre and visual shapes.

    Directory of Open Access Journals (Sweden)

    Mohammad eAdeli

    2014-05-01

    Full Text Available This article investigates the cross-modal correspondences between musical timbre and shapes. Previously, such features as pitch, loudness, light intensity, visual size, and color characteristics have mostly been used in studies of audio-visual correspondences. Moreover, in most studies, simple stimuli e.g. simple tones have been utilized. In this experiment, 23 musical sounds varying in fundamental frequency and timbre but fixed in loudness were used. Each sound was presented once against colored shapes and once against grayscale shapes. Subjects had to select the visual equivalent of a given sound i.e. its shape, color (or grayscale and vertical position. This scenario permitted studying the associations between normalized timbre and visual shapes as well as some of the previous findings for more complex stimuli. 119 subjects (31 females and 88 males participated in the online experiment. Subjects included 36 claimed professional musicians, 47 claimed amateur musicians and 36 claimed non-musicians. 31 subjects have also claimed to have synesthesia-like experiences. A strong association between timbre of envelope normalized sounds and visual shapes was observed. Subjects have strongly associated soft timbres with blue, green or light gray rounded shapes, harsh timbres with red, yellow or dark gray sharp angular shapes and timbres having elements of softness and harshness together with a mixture of the two previous shapes. Color or grayscale had no effect on timbre-shape associations. Fundamental frequency was not associated with height, grayscale or color. The significant correspondence between timbre and shape revealed by the present work allows designing substitution systems which might help the blind to perceive shapes through timbre.

  15. SHAPE Selection (SHAPES) enrich for RNA structure signal in SHAPE sequencing-based probing data.

    Science.gov (United States)

    Poulsen, Line Dahl; Kielpinski, Lukasz Jan; Salama, Sofie R; Krogh, Anders; Vinther, Jeppe

    2015-05-01

    Selective 2' Hydroxyl Acylation analyzed by Primer Extension (SHAPE) is an accurate method for probing of RNA secondary structure. In existing SHAPE methods, the SHAPE probing signal is normalized to a no-reagent control to correct for the background caused by premature termination of the reverse transcriptase. Here, we introduce a SHAPE Selection (SHAPES) reagent, N-propanone isatoic anhydride (NPIA), which retains the ability of SHAPE reagents to accurately probe RNA structure, but also allows covalent coupling between the SHAPES reagent and a biotin molecule. We demonstrate that SHAPES-based selection of cDNA-RNA hybrids on streptavidin beads effectively removes the large majority of background signal present in SHAPE probing data and that sequencing-based SHAPES data contain the same amount of RNA structure data as regular sequencing-based SHAPE data obtained through normalization to a no-reagent control. Moreover, the selection efficiently enriches for probed RNAs, suggesting that the SHAPES strategy will be useful for applications with high-background and low-probing signal such as in vivo RNA structure probing. © 2015 Poulsen et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  16. Modeling the shape of a noncircular toroidal field coil

    International Nuclear Information System (INIS)

    Shah, V.N.; Marshall, N.H.

    1983-01-01

    Operating and transient forces acting on toroidal field coils may cause conductors and insulation to slide or break and may lead to quenching of the coil. Therefore, it is essential that each individual turn of the coil be modeled for detailed analysis of the coil structure. For this, a special purpose computer program is needed. As a first step in developing such a computer program, the authors present a finite element analysis of a turn of noncircular coil subjected to electromagnetic loading. A turn of superconducting coil is represented by a thin ring modeled by curved finite elements. Of the several curved beam elements reported in the literature, the strain element with two nodes, six degrees-of-freedom, and constant radius of curvature converges fastest for thin-deep arches whose geometrical characteristics are similar to those of a turn of toroidal field coil. They present an algorithm to model a noncircular ring using the number of strain elements satisfying the continuity of slopes at their nodes. This paper verifies the finite element model of a coil shape subjected to a toroidal magnetic field by solving three problems: circular and elliptic coils with the same inner and outer radii, a D-shaped coil, and a compound coil consisting of C- and D-shaped segments. The first problem shows that the resultant vertical force in the upper half of the coil is independent of coil shape. The remaining two problems calculate stresses that represent the constant tension in the D-shaped coil and in each segment of the compound coil. The results of the three problems compare well with the analytical results

  17. A two-stage shape optimization process for cavity preparation.

    Science.gov (United States)

    Shi, Li; Fok, Alex S L; Qualtrough, Alison

    2008-11-01

    Clinical data indicate that previously restored teeth are more likely to fracture under occlusal loads. The reason for this is attributed to the high stresses at the tooth-restoration interface, especially following debonding of the restoration from the tooth. This work aims to minimise these interfacial stresses by optimizing the cavity shape using modern shape optimisation techniques. Shape optimisation methods based on the principle of biological adaptive growth were incorporated into a finite element program and used to optimize the design of cavity preparations as previous work had successfully used one such method to minimise stresses at the internal line angles of conventional restorations with defective bonds. The overall shapes of the cavity preparations were maintained while the profiles of the internal line angles were modified. In the present study, the overall shape of the cavity preparation was also subject to modification in the optimization process. A topological optimization method which placed the restorative material according to the stress distribution was first used to obtain a draft design for the cavity shape, assuming perfect bonding at the tooth-restoration interface. The draft shape was then refined using the method employed in the previous study, to allow for deterioration in the interfacial bond strength. These optimization methods were incorporated into the commercial finite element package ABAQUS as a User Material Subroutine (UMAT) to automate the optimization process. Compared with the conventional design, the stress level at the tooth-restoration interface in the optimized design was reduced significantly, irrespective of the bonding condition. Finite-element based shape optimization methods provide a useful tool for minimizing the interfacial stresses in dental restorations. The longevity of restored teeth using the optimized designs is therefore expected to be prolonged.

  18. Organizational culture shapes the adoption and incorporation of simulation into nursing curricula: a grounded theory study.

    Science.gov (United States)

    Taplay, Karyn; Jack, Susan M; Baxter, Pamela; Eva, Kevin; Martin, Lynn

    2014-01-01

    Purpose. To create a substantive mid-range theory explaining how the organizational cultures of undergraduate nursing programs shape the adoption and incorporation of mid-to high-level technical fidelity simulators as a teaching strategy within curricula. Method. A constructivist grounded theory was used to guide this study which was conducted in Ontario, Canada, during 2011-12. Semistructured interviews (n = 43) with participants that included nursing administrators, nursing faculty, and simulation leaders across multiple programs (n = 13) informed this study. Additionally, key documents (n = 67) were reviewed. Purposeful and theoretical sampling was used and data were collected and analyzed simultaneously. Data were compared among and between sites. Findings. The organizational elements that shape simulation in nursing (OESSN) model depicts five key organizational factors at the nursing program level that shaped the adoption and incorporation of simulation: (1) leaders working in tandem, (2) information exchange, (3) physical locale, (4) shared motivators, and (5) scaffolding to manage change. Conclusions. The OESSN model provides an explanation of the organizational factors that contributed to the adoption and incorporation of simulation into nursing curricula. Nursing programs that use the OESSN model may experience a more rapid or broad uptake of simulation when organizational factors that impact adoption and incorporation are considered and planned for.

  19. Organizational Culture Shapes the Adoption and Incorporation of Simulation into Nursing Curricula: A Grounded Theory Study

    Directory of Open Access Journals (Sweden)

    Karyn Taplay

    2014-01-01

    Full Text Available Purpose. To create a substantive mid-range theory explaining how the organizational cultures of undergraduate nursing programs shape the adoption and incorporation of mid-to high-level technical fidelity simulators as a teaching strategy within curricula. Method. A constructivist grounded theory was used to guide this study which was conducted in Ontario, Canada, during 2011-12. Semistructured interviews (n=43 with participants that included nursing administrators, nursing faculty, and simulation leaders across multiple programs (n=13 informed this study. Additionally, key documents (n=67 were reviewed. Purposeful and theoretical sampling was used and data were collected and analyzed simultaneously. Data were compared among and between sites. Findings. The organizational elements that shape simulation in nursing (OESSN model depicts five key organizational factors at the nursing program level that shaped the adoption and incorporation of simulation: (1 leaders working in tandem, (2 information exchange, (3 physical locale, (4 shared motivators, and (5 scaffolding to manage change. Conclusions. The OESSN model provides an explanation of the organizational factors that contributed to the adoption and incorporation of simulation into nursing curricula. Nursing programs that use the OESSN model may experience a more rapid or broad uptake of simulation when organizational factors that impact adoption and incorporation are considered and planned for.

  20. Plane-wave basis finite elements and boundary elements for three-dimensional wave scattering.

    Science.gov (United States)

    Perrey-Debain, E; Laghrouche, O; Bettess, P; Trevelyan, J

    2004-03-15

    Classical finite-element and boundary-element formulations for the Helmholtz equation are presented, and their limitations with respect to the number of variables needed to model a wavelength are explained. A new type of approximation for the potential is described in which the usual finite-element and boundary-element shape functions are modified by the inclusion of a set of plane waves, propagating in a range of directions evenly distributed on the unit sphere. Compared with standard piecewise polynomial approximation, the plane-wave basis is shown to give considerable reduction in computational complexity. In practical terms, it is concluded that the frequency for which accurate results can be obtained, using these new techniques, can be up to 60 times higher than that of the conventional finite-element method, and 10 to 15 times higher than that of the conventional boundary-element method.

  1. Fostering collective intelligence education

    Directory of Open Access Journals (Sweden)

    Jaime Meza

    2016-06-01

    Full Text Available New educational models are necessary to update learning environments to the digitally shared communication and information. Collective intelligence is an emerging field that already has a significant impact in many areas and will have great implications in education, not only from the side of new methodologies but also as a challenge for education. This paper proposes an approach to a collective intelligence model of teaching using Internet to combine two strategies: idea management and real time assessment in the class. A digital tool named Fabricius has been created supporting these two elements to foster the collaboration and engagement of students in the learning process. As a result of the research we propose a list of KPI trying to measure individual and collective performance. We are conscious that this is just a first approach to define which aspects of a class following a course can be qualified and quantified.

  2. Origin and nature of spontaneous shape fluctuations in "small" nanoparticles.

    Science.gov (United States)

    Yang, Ying; Zhang, Hao; Douglas, Jack F

    2014-07-22

    Normally chemically inert materials such as Au have been found to be catalytically active in the form of particles whose size is about 1 nm. Direct and indirect observations of various types of metal nanoparticles (NPs) in this size range, under catalytically relevant conditions for fuel-cell operation and catalysis, have indicated that such "small" particles can exhibit large spontaneous shape fluctuations and significant changes in shape and chemical activity in response to alterations in environmental conditions. NPs also normally exhibit facile coalescence when in proximity, impacting their stability and reactivity in applications. We perform molecular dynamics simulations on Ni nanoparticles, a commonly used NP in catalytic applications and carbon nanotube growth, in the ≈1 nm size regime where large-scale shape fluctuations have been observed experimentally. An analysis of the large-scale shape fluctuations observed in our simulations of these "small" NPs indicates that they are accompanied by collective motion of Ni atoms through the NP center, and we quantify these dynamic structures and their impact on NP shape. In contrast, stringlike collective atomic motion is confined to the NP interfacial region of NPs having a diameter greater than a few nanometers, and correspondingly, the overall NP shape remains roughly spherical, a case studied in our prior Ni NP simulations. Evidently, the large spontaneous NP shape fluctuations reflect a change in character of the collective atomic dynamics when the NPs become critically small in size.

  3. The Ekamanganese elements

    International Nuclear Information System (INIS)

    Noddack, W.; Tacke, I.; Berg, O.

    1988-03-01

    A recent study tends to revalidate the search for element 43 done in 1925. In ores with properties similar to the hypothetical chemical properties of the missing elements 43 and 75, the unknown elements were concentrated by chemical means. Roentgen-ray spectroscopy was applied in order to observe the characteristic Roentgen L lines for element 75 and K lines for element 43. Element 43 was observed in sperrylith, gadolinit, fergusonit and columbit. The name masurium was proposed. Similarly, element 75 was observed in tantalit, wolframit and platinit. The name rhenium was chosen. (MCB)

  4. Shape memory alloy heat engines and energy harvesting systems

    Science.gov (United States)

    Browne, Alan L; Johnson, Nancy L; Keefe, Andrew C; Alexander, Paul W; Sarosi, Peter Maxwell; Herrera, Guillermo A; Yates, James Ryan

    2013-12-17

    A heat engine includes a first rotatable pulley and a second rotatable pulled spaced from the first rotatable pulley. A shape memory alloy (SMA) element is disposed about respective portions of the pulleys at an SMA pulley ratio. The SMA element includes first spring coil and a first fiber core within the first spring coil. A timing cable is disposed about disposed about respective portions of the pulleys at a timing pulley ratio, which is different than the SMA pulley ratio. The SMA element converts a thermal energy gradient between the hot region and the cold region into mechanical energy.

  5. THE TRIAD SYMBOL-SHAPE-COLOUR IN LOGO GRAPHICS

    Directory of Open Access Journals (Sweden)

    Diana NICOLESCU Diana

    2011-11-01

    Full Text Available In this article I have presented elements of logo design, shape-colour-symbol, that represent the graphic expression of identity as well as their importance when considering conceiving a logo. Creating a logo is an important process because the logo is considered the most representative feature of visual identity.

  6. THE TRIAD SYMBOL-SHAPE-COLOUR IN LOGO GRAPHICS

    OpenAIRE

    Diana NICOLESCU Diana

    2011-01-01

    In this article I have presented elements of logo design, shape-colour-symbol, that represent the graphic expression of identity as well as their importance when considering conceiving a logo. Creating a logo is an important process because the logo is considered the most representative feature of visual identity.

  7. Thermomechanical Modeling of Shape Memory Alloys and Applications

    Science.gov (United States)

    Lexcellent, C.; Leclercq, S.

    The aim of the present paper is a general macroscopic description of the thermomechanical behavior of shape memory alloys (SMA). We use for framework the thermodynamics of irreversible processes. This model is efficient for describing the behavior of "smart" structures as a bronchial, a tentacle element and an prosthesis hybrid structure made of Ti Ni SMA wires embedded in a resin epoxy matrix.

  8. Surface shape memory in polymers

    Science.gov (United States)

    Mather, Patrick

    2012-02-01

    Many crosslinked polymers exhibit a shape memory effect wherein a permanent shape can be prescribed during crosslinking and arbitrary temporary shapes may be set through network chain immobilization. Researchers have extensively investigated such shape memory polymers in bulk form (bars, films, foams), revealing a multitude of approaches. Applications abound for such materials and a significant fraction of the studies in this area concern application-specific characterization. Recently, we have turned our attention to surface shape memory in polymers as a means to miniaturization of the effect, largely motivated to study the interaction of biological cells with shape memory polymers. In this presentation, attention will be given to several approaches we have taken to prepare and study surface shape memory phenomenon. First, a reversible embossing study involving a glassy, crosslinked shape memory material will be presented. Here, the permanent shape was flat while the temporary state consisted of embossed parallel groves. Further the fixing mechanism was vitrification, with Tg adjusted to accommodate experiments with cells. We observed that the orientation and spreading of adherent cells could be triggered to change by the topographical switch from grooved to flat. Second, a functionally graded shape memory polymer will be presented, the grading being a variation in glass transition temperature in one direction along the length of films. Characterization of the shape fixing and recovery of such films utilized an indentation technique that, along with polarizing microscopy, allowed visualization of stress distribution in proximity to the indentations. Finally, very recent research concerning shape memory induced wrinkle formation on polymer surfaces will be presented. A transformation from smooth to wrinkled surfaces at physiological temperatures has been observed to have a dramatic effect on the behavior of adherent cells. A look to the future in research and

  9. Modeling the shape memory effect of shape memory polymer

    Science.gov (United States)

    Zhou, Bo; Liu, Yanju; Wang, Zhenqing; Leng, Jin-Song

    2009-07-01

    Dynamic mechanical analysis (DMA) tests are conducted on the styrene-based shape memory polymer (SMP) to investigate its state transition behaviors. Tensile tests at various constant temperatures are carried out to reveal the stressstrain- temperature relationship of the styrene-based SMP. A new mechanical constitutive equation is developed to describe the stress-strain-temperature relationship of the styrene-based SMP. Numerical calculations illustrate the proposed theory well describes the thermo-mechanical cycle of shape memory of styrene-based SMP, such as deformation at high temperature, shape fixity, unloading at low temperature and shape recovery.

  10. Stress distributions in finite element analysis of concrete gravity dam ...

    African Journals Online (AJOL)

    Gravity dams are solid structures built of mass concrete material; they maintain their stability against the design loads from the geometric shape, the mass, and the strength of the concrete. The model was meshed with an 8-node biquadratic plane strain quadrilateral (CPE8R) elements, using ABAQUS, a finite element ...

  11. Smart materials based on shape memory alloys: examples from Europe

    International Nuclear Information System (INIS)

    Gotthardt, R.; Scherrer, P.

    2000-01-01

    Shape memory alloys (SMAs) have become increasingly attractive as embedded actuators in polymers yielding adaptive composite structures. In particular, SMA-elements have been used to actively or passively control shape, elastic modules, internal stress level and damping capacity of such smart composites. In the passive approach, copper-base SMA-plates can be used as temperature-sensitive damping elements, an interesting solution to improve the vibrational behaviour of alpine skis for example. Active materials are obtained by the integration of pre-strained Ni-Ti-base thin wires in polymer matrix composites enabling control of the vibrational behaviour through the recovery-stress tuning technique. In this paper, some results of national research programmes in Belgium and Switzerland, mainly concerning the damping capacity, are shown and a new European project entitled ''adaptive composites with embedded shape memory alloy wires'' is presented in which partners from Belgium, Germany, Greece, Great Britain and Switzerland are collaborating. (orig.)

  12. Vaccines: Shaping global health.

    Science.gov (United States)

    Pagliusi, Sonia; Ting, Ching-Chia; Lobos, Fernando

    2017-03-14

    The Developing Countries Vaccine Manufacturers' Network (DCVMN) gathered leaders in immunization programs, vaccine manufacturing, representatives of the Argentinean Health Authorities and Pan American Health Organization, among other global health stakeholders, for its 17th Annual General Meeting in Buenos Aires, to reflect on how vaccines are shaping global health. Polio eradication and elimination of measles and rubella from the Americas is a result of successful collaboration, made possible by timely supply of affordable vaccines. After decades of intense competition for high-value markets, collaboration with developing countries has become critical, and involvement of multiple manufacturers as well as public- and private-sector investments are essential, for developing new vaccines against emerging infectious diseases. The recent Zika virus outbreak and the accelerated Ebola vaccine development exemplify the need for international partnerships to combat infectious diseases. A new player, Coalition for Epidemic Preparedness Innovations (CEPI) has made its entrance in the global health community, aiming to stimulate research preparedness against emerging infections. Face-to-face panel discussions facilitated the dialogue around challenges, such as risks of viability to vaccine development and regulatory convergence, to improve access to sustainable vaccine supply. It was discussed that joint efforts to optimizing regulatory pathways in developing countries, reducing registration time by up to 50%, are required. Outbreaks of emerging infections and the global Polio eradication and containment challenges are reminders of the importance of vaccines' access, and of the importance of new public-private partnerships. Copyright © 2017.

  13. Digital Information Platform Design of Fuel Element Engineering For High Temperature Gas-cooled Reactor

    International Nuclear Information System (INIS)

    Du Yuwei

    2014-01-01

    This product line provide fuel element for high temperature gas-cooled reactor nuclear power plant which is being constructed in Shidao bay in Shandong province. Its annual productive capacity is thirty ten thousands fuel elements whose shape is spherical . Compared with pressurized water fuel , this line has the feature of high radiation .In order to reduce harm to operators, the comprehensive information platform is designed , which can realize integration of automation and management for plant. This platform include two nets, automation net using field bus technique and information net using Ethernet technique ,which realize collection ,control, storage and publish of information.By means of construction, automatization and informatization of product line can reach high level. (author)

  14. A 20-DOF hybrid stress general shell element

    Science.gov (United States)

    Kang, David S.; Pian, Theodore H. H.

    1988-01-01

    A hybrid-stress general shell element is developed based on the Hellinger-Reissner principle modified for relaxed element compatibility conditions. The element is based on a thin-shell theory with Love-Kirchhoff hypothesis. It is of quadrilateral shape with only four corner nodes and five degrees of freedom per node. The geometry of the element is approximated through a cubic polynomial surface patch. Numerical examples consisting of torsion-loaded slit cylinder and pinched cylinders with open ends and rigid diaphragmed ends demonstrate excellent performance of the present element.

  15. Mikromechanisches Element und Sensor zur Ueberwachung eines mikromechanischen Elements

    OpenAIRE

    Klose, T.; Conrad, H.; Grasshoff, T.

    2008-01-01

    DE 102008049647 A1 UPAB: 20100428 NOVELTY - The micromechanical element (100) has a mobile functional element (110) and a retaining element (120), where a retaining element and the functional element are connected at a junction (122). Another retaining element (130) and the functional element are connected at another junction (132). The former retaining element has a piezoelectric drive element (124) and the latter retaining element has another piezoelectric drive element (134). DETAILED DESC...

  16. Shape memory-based actuators and release mechanisms therefrom

    Science.gov (United States)

    Vaidyanathan, Rajan (Inventor); Snyder, Daniel W. (Inventor); Schoenwald, David K. (Inventor); Lam, Nhin S. (Inventor); Watson, Daniel S. (Inventor); Krishnan, Vinu B. (Inventor); Noebe, Ronald D. (Inventor)

    2012-01-01

    SM-based actuators (110) and release mechanisms (100) therefrom and systems (500) including one or more release mechanisms (100). The actuators (110) comprise a SM member (118) and a deformable member (140) mechanically coupled to the SM member (118) which deforms upon a shape change of the SM member triggered by a phase transition of the SM member. A retaining element (160) is mechanically coupled to the deformable member (140), wherein the retaining element (160) moves upon the shape change. Release mechanism (100) include an actuator, a rotatable mechanism (120) including at least one restraining feature (178) for restraining rotational movement of the retaining element (160) before the shape change, and at least one spring (315) that provides at least one locked spring-loaded position when the retaining element is in the restraining feature and at least one released position that is reached when the retaining element is in a position beyond the restraining feature (178). The rotatable mechanism (120) includes at least one load-bearing protrusion (310). A hitch (400) is for mechanically coupling to the load, wherein the hitch is supported on the load bearing protrusion (310) when the rotatable mechanism is in the locked spring-loaded position.

  17. A Method of Assembling Wall or Floor Elements

    DEFF Research Database (Denmark)

    2002-01-01

    as well as longitudinal side edges faces (12), wherein the elements (10), in a first step, are arranged at the site of use in mutual extension and then, in a second step, are connected with each other by means of at least one force-transferring device to form a tight connection. The invention...... is characterized in that a circular ring-shaped depression (20) is provided on the front side and/or the rear side of two adjoining elements (10) after the first step, said circular ring-shaped depression extending in the one as well as the other element (10), that the force-transferring device is a pipe (25...

  18. Shape resonances in molecular fields

    International Nuclear Information System (INIS)

    Dehmer, J.L.

    1984-01-01

    A shape resonance is a quasibound state in which a particle is temporarily trapped by a potential barrier (i.e., the shape of the potential), through which it may eventually tunnel and escape. This simple mechanism plays a prominent role in a variety of excitation processes in molecules, ranging from vibrational excitation by slow electrons to ionization of deep core levels by x-rays. Moreover, their localized nature makes shape resonances a unifying link between otherwise dissimilar circumstances. One example is the close connection between shape resonances in electron-molecule scattering and in molecular photoionization. Another is the frequent persistence of free-molecule shape resonant behavior upon adsorption on a surface or condensation into a molecular solid. The main focus of this article is a discussion of the basic properties of shape resonances in molecular fields, illustrated by the more transparent examples studied over the last ten years. Other aspects to be discussed are vibrational effects of shape resonances, connections between shape resonances in different physical settings, and examples of shape resonant behavior in more complex cases, which form current challenges in this field

  19. Women in Shape Modeling Workshop

    CERN Document Server

    Tari, Sibel

    2015-01-01

    Presenting the latest research from the growing field of mathematical shape analysis, this volume is comprised of the collaborations of participants of the Women in Shape Modeling (WiSh) workshop, held at UCLA's Institute for Pure and Applied Mathematics in July 2013. Topics include: Simultaneous spectral and spatial analysis of shape Dimensionality reduction and visualization of data in tree-spaces, such as classes of anatomical trees like airways and blood vessels Geometric shape segmentation, exploring shape segmentation from a Gestalt perspective, using information from the Blum medial axis of edge fragments in an image Representing and editing self-similar details on 3D shapes, studying shape deformation and editing techniques Several chapters in the book directly address the problem of continuous measures of context-dependent nearness and right shape models. Medical and biological applications have been a major source of motivation in shape research, and key topics are examined here in detail. All...

  20. Shaping Design Teaching

    DEFF Research Database (Denmark)

    Oxman, Rivka; Akner Koler, Cheryl; Bastos, Francisco Teixeira

    This book presents an overview of form-making as it is taught in different architecture and design programs across the world. This diverse collection of pedagogical experiences will certainly be of interest to architecture and design instructors as well as their students. With a few exceptions......, such as the emphasis on materiality in the Bauhaus curriculum, the modernist tradition emphasizes form and space at the beginning of the design process while the defi nition of materials are left to a second phase, and often to a second professional, the structural engineer. Today, material properties and the computer...

  1. The ecology of collective behavior.

    Directory of Open Access Journals (Sweden)

    Deborah M Gordon

    2014-03-01

    Full Text Available Similar patterns of interaction, such as network motifs and feedback loops, are used in many natural collective processes, probably because they have evolved independently under similar pressures. Here I consider how three environmental constraints may shape the evolution of collective behavior: the patchiness of resources, the operating costs of maintaining the interaction network that produces collective behavior, and the threat of rupture of the network. The ants are a large and successful taxon that have evolved in very diverse environments. Examples from ants provide a starting point for examining more generally the fit between the particular pattern of interaction that regulates activity, and the environment in which it functions.

  2. Two-dimensional isostatic meshes in the finite element method

    OpenAIRE

    Martínez Marín, Rubén; Samartín, Avelino

    2002-01-01

    In a Finite Element (FE) analysis of elastic solids several items are usually considered, namely, type and shape of the elements, number of nodes per element, node positions, FE mesh, total number of degrees of freedom (dot) among others. In this paper a method to improve a given FE mesh used for a particular analysis is described. For the improvement criterion different objective functions have been chosen (Total potential energy and Average quadratic error) and the number of nodes and dof's...

  3. New elements - approaching Z=114

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S.

    1998-03-01

    The search for new elements is part of the broader field of investigations of nuclei at the limits of stability. In two series of experiments at SHIP, six new elements (Z=107-112) were synthesized via fusion reactions using 1n-deexcitation channels and lead or bismuth targets. The isotopes were unambiguously identified by means of {alpha}-{alpha} correlations. Not fission, but alpha decay is the dominant decay mode. The collected decay data establish a means of comparison with theoretical data. This aids in the selection of appropriate models that describe the properties of known nuclei. Predictions based on these models are useful in the preparation of the next generation of experiments. Cross-sections decrease by two orders of magnitude from bohrium (Z=107) to element 112, for which a cross-section of 1 pb was measured. The development of intense beam currents and sensitive detection methods is essential for the production and identification of still heavier elements and new isotopes of already known elements, as well as the measurement of small {alpha}-, {beta}- and fission-branching ratios. An equally sensitive set-up is needed for the measurement of excitation functions at low cross-sections. Based on our results, it is likely that the production of isotopes of element 114 close to the island of spherical super heavy elements (SHE) could be achieved by fusion reactions using {sup 208}Pb targets. Systematic studies of the reaction cross-sections indicate that the transfer of nucleons is an important process for the initiation of fusion. The data allow for the fixing of a narrow energy window for the production of SHE using 1n-emission channels. (orig.)

  4. New elements - approaching Z=114

    International Nuclear Information System (INIS)

    Hofmann, S.

    1998-03-01

    The search for new elements is part of the broader field of investigations of nuclei at the limits of stability. In two series of experiments at SHIP, six new elements (Z=107-112) were synthesized via fusion reactions using 1n-deexcitation channels and lead or bismuth targets. The isotopes were unambiguously identified by means of α-α correlations. Not fission, but alpha decay is the dominant decay mode. The collected decay data establish a means of comparison with theoretical data. This aids in the selection of appropriate models that describe the properties of known nuclei. Predictions based on these models are useful in the preparation of the next generation of experiments. Cross-sections decrease by two orders of magnitude from bohrium (Z=107) to element 112, for which a cross-section of 1 pb was measured. The development of intense beam currents and sensitive detection methods is essential for the production and identification of still heavier elements and new isotopes of already known elements, as well as the measurement of small α-, β- and fission-branching ratios. An equally sensitive set-up is needed for the measurement of excitation functions at low cross-sections. Based on our results, it is likely that the production of isotopes of element 114 close to the island of spherical super heavy elements (SHE) could be achieved by fusion reactions using 208 Pb targets. Systematic studies of the reaction cross-sections indicate that the transfer of nucleons is an important process for the initiation of fusion. The data allow for the fixing of a narrow energy window for the production of SHE using 1n-emission channels. (orig.)

  5. A Novel Approach to a Piezoelectric Sensing Element

    Directory of Open Access Journals (Sweden)

    M. Martinez

    2010-01-01

    Full Text Available Piezoelectric materials have commonly been used in pressure and stress sensors; however, many designs consist of thin plate structures that produce small voltage signals when they are compressed or extended under a pressure field. This study used finite element methods to design a novel piezoelectric pressure sensor with a C-shaped piezoelectric element and determine if the voltage signal obtained during hydrostatic pressure application was enhanced compared to a standard thin plate piezoelectric element. The results of this study demonstrated how small deformations of this C-shaped sensor produced a large electrical signal output. It was also shown that the location of the electrodes for this sensor needs to be carefully chosen and that the electric potential distribution varies depending on the poling of the piezoelectric element. This study indicated that the utilization of piezoelectric materials of different shapes and geometries embedded in a polymer matrix for sensing applications has several advantages over thin plate solid piezoelectric structures.

  6. Social shaping of technology in TA and HTA

    DEFF Research Database (Denmark)

    Clausen, Christian; Yoshinaka, Yutaka

    2004-01-01

    The paper discusses how the social shaping of technology (SST) approach may be useful in understanding the role played by technology assessment within the context of technological development and change. It is proposed that an SST perspective on TA (or HTA) yields particular insight, regardless...... of whether or not the TA activity bases itself on a social shaping understanding of technology. This is because SST addresses the socially negotiated character of technological development, where TA itself may be construed as an element influencing the process of such negotiation. At the same time, TA...... is a construction, that is, itself a product of negotiations involving social actors. Thus, an understanding that TA is socially shaped, and is involved in the shaping of technology, opens up for a perspective on TA as both entailing constraints and enablements within the context of the particular agenda...

  7. Isogeometric Analysis and Shape Optimization in Fluid Mechanics

    DEFF Research Database (Denmark)

    Nielsen, Peter Nørtoft

    This thesis brings together the fields of fluid mechanics, as the study of fluids and flows, isogeometric analysis, as a numerical method to solve engineering problems using computers, and shape optimization, as the art of finding "best" shapes of objects based on some notion of goodness. The flow...... unites the power to solve complex engineering problems from finite element analysis (FEA) with the ability to effectively represent complex shapes from computer aided design (CAD). The methodology is appealing for flow modeling purposes also due to the inherent high regularity of velocity and pressure...... approximations, and for shape optimization purposes also due to its tight connection between the analysis and geometry models. The thesis is initiated by short introductions to fluid mechanics, and to the building blocks of isogeometric analysis. As the first contribution of the thesis, a detailed description...

  8. Global point signature for shape analysis of carpal bones

    International Nuclear Information System (INIS)

    Chaudhari, Abhijit J; Badawi, Ramsey D; Leahy, Richard M; Joshi, Anand A; Wise, Barton L; Lane, Nancy E

    2014-01-01

    We present a method based on spectral theory for the shape analysis of carpal bones of the human wrist. We represent the cortical surface of the carpal bone in a coordinate system based on the eigensystem of the two-dimensional Helmholtz equation. We employ a metric—global point signature (GPS)—that exploits the scale and isometric invariance of eigenfunctions to quantify overall bone shape. We use a fast finite-element-method to compute the GPS metric. We capitalize upon the properties of GPS representation—such as stability, a standard Euclidean (ℓ 2 ) metric definition, and invariance to scaling, translation and rotation—to perform shape analysis of the carpal bones of ten women and ten men from a publicly-available database. We demonstrate the utility of the proposed GPS representation to provide a means for comparing shapes of the carpal bones across populations. (paper)

  9. Collective Success or Collective Failure?

    DEFF Research Database (Denmark)

    Fayyaz, Anjum

    , industrial cluster, and corporate social responsibility literatures with the aim of explaining why collective cluster action through industry associations and/or public private partnerships succeed or fail in facilitating cluster-wide compliance with CSR standards. I then use this framework to analyze a case...... study of soccer village project to learn how various attempts at facilitating joint CSR action in the Pakistani football manufacturing have consistently failed in addressing international CSR compliance demands. I conclude that this form of collective failure – along with technological changes, lack...

  10. Elemental analyses of modern dust in southern Nevada and California

    Science.gov (United States)

    Reheis, M.C.; Budahn, J.R.; Lamothe, P.J.

    1999-01-01

    Selected samples of modern dust collected in marble traps at sites in southern Nevada and California (Reheis and Kihl, 1995; Reheis, 1997) have been analyzed for elemental composition using instrumental neutron activation analysis (INAA) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectroscopy (ICP-MS). For information on these analytical techniques and their levels of precision and accuracy, refer to Baedecker and McKown (1987) for INAA, to Briggs (1996) for ICP-AES, and to Briggs and Meier (1999) for ICP-MS. This report presents the elemental compositions obtained using these techniques on dust samples collected from 1991 through 1997.The dust-trap sites were established at varying times; some have been maintained since 1984, others since 1991. For details on site location, dust-trap construction, and collection techniques, see Reheis and Kihl (1995) and Reheis (1997). Briefly, the trap consists of a coated angel-food cake pan painted black on the outside and mounted on a post about 2 m above the ground. Glass marbles rest on a circular piece of galvanized hardware cloth (now replaced by stainless-steel mesh), which is fitted into the pan so that it rests 3-4 cm below the rim. The 2-m height eliminates most saltating sand-sized particles. The marbles simulate the effect of a gravelly fan surface and prevent dust that has filtered or washed into the bottom of the pan from being blown back out. The dust traps are fitted with two metal straps looped in an inverted basket shape; the top surfaces of the straps are coated with a sticky material that effectively discourages birds from roosting.

  11. Duplicated Renal System with H Shaped Ureter: An Extraordinary Anomaly

    Directory of Open Access Journals (Sweden)

    Fatih Akbulut

    2016-01-01

    Full Text Available Duplex collecting systems are the most commonly encountered anomaly of the urinary system. Complete duplex system with an H shaped ureter is a very rare situation. There are only two reported H ureter cases in the literature. Herein, we aimed to present an H shaped ureter case, which was identified while performing ureterorenoscopy to a 48-year-old female patient due to a right distal ureteral stone.

  12. Shear Behavior of Corrugated Steel Webs in H Shape Bridge Girders

    Directory of Open Access Journals (Sweden)

    Qi Cao

    2015-01-01

    Full Text Available In bridge engineering, girders with corrugated steel webs have shown good mechanical properties. With the promotion of composite bridge with corrugated steel webs, in particular steel-concrete composite girder bridge with corrugated steel webs, it is necessary to study the shear performance and buckling of the corrugated webs. In this research, by conducting experiment incorporated with finite element analysis, the stability of H shape beam welded with corrugated webs was tested and three failure modes were observed. Structural data including load-deflection, load-strain, and shear capacity of tested beam specimens were collected and compared with FEM analytical results by ANSYS software. The effects of web thickness, corrugation, and stiffening on shear capacity of corrugated webs were further discussed.

  13. Supernova Explosions Stay In Shape

    Science.gov (United States)

    2009-12-01

    At a very early age, children learn how to classify objects according to their shape. Now, new research suggests studying the shape of the aftermath of supernovas may allow astronomers to do the same. A new study of images from NASA's Chandra X-ray Observatory on supernova remnants - the debris from exploded stars - shows that the symmetry of the remnants, or lack thereof, reveals how the star exploded. This is an important discovery because it shows that the remnants retain information about how the star exploded even though hundreds or thousands of years have passed. "It's almost like the supernova remnants have a 'memory' of the original explosion," said Laura Lopez of the University of California at Santa Cruz, who led the study. "This is the first time anyone has systematically compared the shape of these remnants in X-rays in this way." Astronomers sort supernovas into several categories, or "types", based on properties observed days after the explosion and which reflect very different physical mechanisms that cause stars to explode. But, since observed remnants of supernovas are leftover from explosions that occurred long ago, other methods are needed to accurately classify the original supernovas. Lopez and colleagues focused on the relatively young supernova remnants that exhibited strong X-ray emission from silicon ejected by the explosion so as to rule out the effects of interstellar matter surrounding the explosion. Their analysis showed that the X-ray images of the ejecta can be used to identify the way the star exploded. The team studied 17 supernova remnants both in the Milky Way galaxy and a neighboring galaxy, the Large Magellanic Cloud. For each of these remnants there is independent information about the type of supernova involved, based not on the shape of the remnant but, for example, on the elements observed in it. The researchers found that one type of supernova explosion - the so-called Type Ia - left behind relatively symmetric, circular

  14. Concurrent Collections

    OpenAIRE

    Budimlić, Zoran; Burke, Michael; Cavé, Vincent; Knobe, Kathleen; Lowney, Geoff; Newton, Ryan; Palsberg, Jens; Peixotto, David; Sarkar, Vivek; Schlimbach, Frank; Taşırlar, Sağnak

    2010-01-01

    We introduce the Concurrent Collections (CnC) programming model. CnC supports flexible combinations of task and data parallelism while retaining determinism. CnC is implicitly parallel, with the user providing high-level operations along with semantic ordering constraints that together form a CnC graph. We formally describe the execution semantics of CnC and prove that the model guarantees deterministic computation. We evaluate the performance of CnC implementations on several applications an...

  15. Young Children's Concepts of Shape.

    Science.gov (United States)

    Clements, Douglas H.; Swaminathan, Sudha; Hannibal, Mary Anne Zeitler; Sarama, Julie

    1999-01-01

    Investigates, by conducting individual clinical interviews of 97 children ages 3 to 6, the criteria preschool children use to distinguish members of a class of shapes from other figures, emphasizing identification and descriptions of shapes and reasons for these identifications. Concludes that young children initially form schemas on the basis of…

  16. Element-ary Development.

    Science.gov (United States)

    Schamp, Homer W., Jr.

    1989-01-01

    Describes the historic development of the periodic table from the four-element theory to the Lavoisier's table. Presents a table listing the old and new names of chemicals and the Lavoisier's table of elements. Lists two references. (YP)

  17. Data Element Registry Services

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data Element Registry Services (DERS) is a resource for information about value lists (aka code sets / pick lists), data dictionaries, data elements, and EPA data...

  18. Analysis of intelligent hinged shell structures: deployable deformation and shape memory effect

    International Nuclear Information System (INIS)

    Shi, Guang-Hui; Yang, Qing-Sheng; He, X Q

    2013-01-01

    Shape memory polymers (SMPs) are a class of intelligent materials with the ability to recover their initial shape from a temporarily fixable state when subjected to external stimuli. In this work, the thermo-mechanical behavior of a deployable SMP-based hinged structure is modeled by the finite element method using a 3D constitutive model with shape memory effect. The influences of hinge structure parameters on the nonlinear loading process are investigated. The total shape memory of the processes the hinged structure goes through, including loading at high temperature, decreasing temperature with load carrying, unloading at low temperature and recovering the initial shape with increasing temperature, are illustrated. Numerical results show that the present constitutive theory and the finite element method can effectively predict the complicated thermo-mechanical deformation behavior and shape memory effect of SMP-based hinged shell structures. (paper)

  19. Functional and shape data analysis

    CERN Document Server

    Srivastava, Anuj

    2016-01-01

    This textbook for courses on function data analysis and shape data analysis describes how to define, compare, and mathematically represent shapes, with a focus on statistical modeling and inference. It is aimed at graduate students in analysis in statistics, engineering, applied mathematics, neuroscience, biology, bioinformatics, and other related areas. The interdisciplinary nature of the broad range of ideas covered—from introductory theory to algorithmic implementations and some statistical case studies—is meant to familiarize graduate students with an array of tools that are relevant in developing computational solutions for shape and related analyses. These tools, gleaned from geometry, algebra, statistics, and computational science, are traditionally scattered across different courses, departments, and disciplines; Functional and Shape Data Analysis offers a unified, comprehensive solution by integrating the registration problem into shape analysis, better preparing graduate students for handling fu...

  20. Pileup subtraction for jet shapes

    CERN Document Server

    Soyez, Gregory; Kim, Jihun; Dutta, Souvik; Cacciari, Matteo

    2013-01-01

    Jet shapes have the potential to play a role in many LHC analyses, for example in quark-gluon discrimination or jet substructure analyses for hadronic decays of boosted heavy objects. Most shapes, however, are significantly affected by pileup. We introduce a general method to correct for pileup effects in shapes, which acts event-by-event and jet-by-jet, and accounts also for hadron masses. It involves a numerical determination, for each jet, of a given shape's susceptibility to pileup. Together with existing techniques for determining the level of pileup, this then enables an extrapolation to zero pileup. The method can be used for a wide range of jet shapes and we show its successful application in the context of quark/gluon discrimination and top-tagging.

  1. Basic Finite Element Method

    International Nuclear Information System (INIS)

    Lee, Byeong Hae

    1992-02-01

    This book gives descriptions of basic finite element method, which includes basic finite element method and data, black box, writing of data, definition of VECTOR, definition of matrix, matrix and multiplication of matrix, addition of matrix, and unit matrix, conception of hardness matrix like spring power and displacement, governed equation of an elastic body, finite element method, Fortran method and programming such as composition of computer, order of programming and data card and Fortran card, finite element program and application of nonelastic problem.

  2. AERIAL MEASUREMENTS OF CONVECTION CELL ELEMENTS IN HEATED LAKES

    Energy Technology Data Exchange (ETDEWEB)

    Villa-Aleman, E; Saleem Salaymeh, S; Timothy Brown, T; Alfred Garrett, A; Malcolm Pendergast, M; Linda Nichols, L

    2007-12-19

    Power plant-heated lakes are characterized by a temperature gradient in the thermal plume originating at the discharge of the power plant and terminating at the water intake. The maximum water temperature discharged by the power plant into the lake depends on the power generated at the facility and environmental regulations on the temperature of the lake. Besides the observed thermal plume, cloud-like thermal cells (convection cell elements) are also observed on the water surface. The size, shape and temperature of the convection cell elements depends on several parameters such as the lake water temperature, wind speed, surfactants and the depth of the thermocline. The Savannah River National Laboratory (SRNL) and Clemson University are collaborating to determine the applicability of laboratory empirical correlations between surface heat flux and thermal convection intensity. Laboratory experiments at Clemson University have demonstrated a simple relationship between the surface heat flux and the standard deviation of temperature fluctuations. Similar results were observed in the aerial thermal imagery SRNL collected at different locations along the thermal plume and at different elevations. SRNL will present evidence that the results at Clemson University are applicable to cooling lakes.

  3. Snout shape in extant ruminants.

    Directory of Open Access Journals (Sweden)

    Jonathan P Tennant

    Full Text Available Snout shape is a prominent aspect of herbivore feeding ecology, interacting with both forage selectivity and intake rate. Previous investigations have suggested ruminant feeding styles can be discriminated via snout shape, with grazing and browsing species characterised by 'blunt' and 'pointed' snouts respectively, often with specification of an 'intermediate' sub-grouping to represent ambiguous feeding styles and/or morphologies. Snout shape morphology is analysed here using a geometric morphometric approach to compare the two-dimensional profiles of the premaxilla in ventral aspect for a large sample of modern ruminant species, for which feeding modes are known from secondary criteria. Results suggest that, when browsing and grazing ruminants are classified ecologically based on a range of feeding style indicators, they cannot be discriminated unambiguously on the basis of snout profile shape alone. Profile shapes in our sample form a continuum with substantial overlap between groupings and a diverse range of morphologies. Nevertheless, we obtained an 83.8 percent ratio of correct post hoc feeding style categorisations based on the proximity of projected profile shapes to group centroids in the discriminant space. Accordingly, this procedure for identifying species whose feeding strategy is 'unknown' can be used with a reasonable degree of confidence, especially if backed-up by additional information. Based on these results we also refine the definitions of snout shape varieties, taking advantage of the descriptive power that geometric morphometrics offers to characterize the morphological disparities observed. The shape variance exhibited by both browsing and grazing ruminants corresponds strongly to body mass, providing further evidence for an interaction between snout shape, feeding style, and body size evolution. Finally, by exploring the role of phylogenetic similarity in snout shape, we find a slight increase in successful categorisation

  4. Capturing the surface texture and shape of pollen: a comparison of microscopy techniques.

    Directory of Open Access Journals (Sweden)

    Mayandi Sivaguru

    Full Text Available Research on the comparative morphology of pollen grains depends crucially on the application of appropriate microscopy techniques. Information on the performance of microscopy techniques can be used to inform that choice. We compared the ability of several microscopy techniques to provide information on the shape and surface texture of three pollen types with differing morphologies. These techniques are: widefield, apotome, confocal and two-photon microscopy (reflected light techniques, and brightfield and differential interference contrast microscopy (DIC (transmitted light techniques. We also provide a first view of pollen using super-resolution microscopy. The three pollen types used to contrast the performance of each technique are: Croton hirtus (Euphorbiaceae, Mabea occidentalis (Euphorbiaceae and Agropyron repens (Poaceae. No single microscopy technique provided an adequate picture of both the shape and surface texture of any of the three pollen types investigated here. The wavelength of incident light, photon-collection ability of the optical technique, signal-to-noise ratio, and the thickness and light absorption characteristics of the exine profoundly affect the recovery of morphological information by a given optical microscopy technique. Reflected light techniques, particularly confocal and two-photon microscopy, best capture pollen shape but provide limited information on very fine surface texture. In contrast, transmitted light techniques, particularly differential interference contrast microscopy, can resolve very fine surface texture but provide limited information on shape. Texture comprising sculptural elements that are spaced near the diffraction limit of light (~250 nm; NDL presents an acute challenge to optical microscopy. Super-resolution structured illumination microscopy provides data on the NDL texture of A. repens that is more comparable to textural data from scanning electron microscopy than any other optical

  5. Do endothelial cells dream of eclectic shape?

    Science.gov (United States)

    Bentley, Katie; Philippides, Andrew; Ravasz Regan, Erzsébet

    2014-04-28

    Endothelial cells (ECs) exhibit dramatic plasticity of form at the single- and collective-cell level during new vessel growth, adult vascular homeostasis, and pathology. Understanding how, when, and why individual ECs coordinate decisions to change shape, in relation to the myriad of dynamic environmental signals, is key to understanding normal and pathological blood vessel behavior. However, this is a complex spatial and temporal problem. In this review we show that the multidisciplinary field of Adaptive Systems offers a refreshing perspective, common biological language, and straightforward toolkit that cell biologists can use to untangle the complexity of dynamic, morphogenetic systems. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. A comparison between different finite elements for elastic and aero-elastic analyses.

    Science.gov (United States)

    Mahran, Mohamed; ELsabbagh, Adel; Negm, Hani

    2017-11-01

    In the present paper, a comparison between five different shell finite elements, including the Linear Triangular Element, Linear Quadrilateral Element, Linear Quadrilateral Element based on deformation modes, 8-node Quadrilateral Element, and 9-Node Quadrilateral Element was presented. The shape functions and the element equations related to each element were presented through a detailed mathematical formulation. Additionally, the Jacobian matrix for the second order derivatives was simplified and used to derive each element's strain-displacement matrix in bending. The elements were compared using carefully selected elastic and aero-elastic bench mark problems, regarding the number of elements needed to reach convergence, the resulting accuracy, and the needed computation time. The best suitable element for elastic free vibration analysis was found to be the Linear Quadrilateral Element with deformation-based shape functions, whereas the most suitable element for stress analysis was the 8-Node Quadrilateral Element, and the most suitable element for aero-elastic analysis was the 9-Node Quadrilateral Element. Although the linear triangular element was the last choice for modal and stress analyses, it establishes more accurate results in aero-elastic analyses, however, with much longer computation time. Additionally, the nine-node quadrilateral element was found to be the best choice for laminated composite plates analysis.

  7. On the shape memory of red blood cells

    Science.gov (United States)

    Cordasco, Daniel; Bagchi, Prosenjit

    2017-04-01

    Red blood cells (RBCs) undergo remarkably large deformations when subjected to external forces but return to their biconcave discoid resting shape as the forces are withdrawn. In many experiments, such as when RBCs are subjected to a shear flow and undergo the tank-treading motion, the membrane elements are also displaced from their original (resting) locations along the cell surface with respect to the cell axis, in addition to the cell being deformed. A shape memory is said to exist if after the flow is stopped the RBC regains its biconcave shape and the membrane elements also return to their original locations. The shape memory of RBCs was demonstrated by Fischer ["Shape memory of human red blood cells," Biophys. J. 86, 3304-3313 (2004)] using shear flow go-and-stop experiments. Optical tweezer and micropipette based stretch-relaxation experiments do not reveal the complete shape memory because while the RBC may be deformed, the membrane elements are not significantly displaced from their original locations with respect to the cell axis. Here we present the first three-dimensional computational study predicting the complete shape memory of RBCs using shear flow go-and-stop simulations. The influence of different parameters, namely, membrane shear elasticity and bending rigidity, membrane viscosity, cytoplasmic and suspending fluid viscosity, as well as different stress-free states of the RBC is studied. For all cases, the RBCs always exhibit shape memory. The complete recovery of the RBC in shear flow go-and-stop simulations occurs over a time that is orders of magnitude longer than that for optical tweezer and micropipette based relaxations. The response is also observed to be more complex and composed of widely disparate time scales as opposed to only one time scale that characterizes the optical tweezer and micropipette based relaxations. We observe that the recovery occurs in three phases: a rapid compression of the RBC immediately after the flow is stopped

  8. Light collection and its fluctuation in Cherenkov and scintillation spectrometers

    International Nuclear Information System (INIS)

    Kitaev, D.F.; Samedov, V.V.; Stolyarova, E.L.

    1982-01-01

    The GAMMA program for calculating light collection in the Cherenkov and scintillation counters is described. Together with the shower modelling program the GAMNA program can be used for evaluating the output signal and energy resolution of shower spectrometers. Principle formulae and block diagram of the program are given. Results of test calculations performed on the example of scintillation counters of culindrical and rectangular shapes were considered. Modelling of the radiation polarization envisaged in the program permits to take account of the effect of selective discrimination of photoelectron amplifier photocathode. The program analyzes, for the present situation, calculation errors which permits to plan in advance the calculation with the given accuracy. The program permits to use additional subprograms together with it where it is possible to take account of other peculiarities of light collection, for example, the presence of outer reflectors and focusing elements of light collection systems, particle slowing down in the spectrometer radiator expressed in the change of angle of semiaperture of the Cherenkov radiation cone. It is concluded on the basis of analyzing results of test calculations that the choosen technique and algorithms of light collection coefficient calculation in spectrometer radiators are correct

  9. Collective Security

    DEFF Research Database (Denmark)

    Galster, Kjeld

    and real defence of the country’s neutrality let alone a capability to support possible League of Nations action, should such need arise. The anti-militarist ideology of one party, led to regarding the armed services as harmful to designs for developing civic society and a waste of resources generally...... disinclination to accept that the collective security concept and international treaties and accords signed by Denmark should necessitate credible and real defence of the country’s neutrality let alone a capability to support possible League of Nations action, should such need arise. The anti-militarist ideology...

  10. Concurrent Collections

    Directory of Open Access Journals (Sweden)

    Zoran Budimlić

    2010-01-01

    Full Text Available We introduce the Concurrent Collections (CnC programming model. CnC supports flexible combinations of task and data parallelism while retaining determinism. CnC is implicitly parallel, with the user providing high-level operations along with semantic ordering constraints that together form a CnC graph. We formally describe the execution semantics of CnC and prove that the model guarantees deterministic computation. We evaluate the performance of CnC implementations on several applications and show that CnC offers performance and scalability equivalent to or better than that offered by lower-level parallel programming models.

  11. Rare (Earth Elements [score

    Directory of Open Access Journals (Sweden)

    Camilo Méndez

    2014-12-01

    Full Text Available Rare (Earth Elements is a cycle of works for solo piano. The cycle was inspired by James Dillon’s Book of Elements (Vol. I-V. The complete cycle will consist of 14 pieces; one for each selected rare (earth element. The chosen elements are Neodymium, Erbium, Tellurium, Hafnium, Tantalum, Technetium, Indium, Dysprosium, Lanthanium, Cerium, Europium, Terbium, Yttrium and Darmstadtium. These elements were selected due to their special atomic properties that in many cases make them extremely valuable for the development of new technologies, and also because of their scarcity. To date, only 4 works have been completed Yttrium, Technetium, Indium and Tellurium.

  12. Characterization of the bell-shaped vibratory angular rate gyro.

    Science.gov (United States)

    Liu, Ning; Su, Zhong; Li, Qing; Fu, MengYin; Liu, Hong; Fan, JunFang

    2013-08-07

    The bell-shaped vibratory angular rate gyro (abbreviated as BVG) is a novel shell vibratory gyroscope, which is inspired by the Chinese traditional bell. It sensitizes angular velocity through the standing wave precession effect. The bell-shaped resonator is a core component of the BVG and looks like the millimeter-grade Chinese traditional bell, such as QianLong Bell and Yongle Bell. It is made of Ni43CrTi, which is a constant modulus alloy. The exciting element, control element and detection element are uniformly distributed and attached to the resonator, respectively. This work presents the design, analysis and experimentation on the BVG. It is most important to analyze the vibratory character of the bell-shaped resonator. The strain equation, internal force and the resonator's equilibrium differential equation are derived in the orthogonal curvilinear coordinate system. When the input angular velocity is existent on the sensitive axis, an analysis of the vibratory character is performed using the theory of thin shells. On this basis, the mode shape function and the simplified second order normal vibration mode dynamical equation are obtained. The coriolis coupling relationship about the primary mode and secondary mode is established. The methods of the signal processing and control loop are presented. Analyzing the impact resistance property of the bell-shaped resonator, which is compared with other shell resonators using the Finite Element Method, demonstrates that BVG has the advantage of a better impact resistance property. A reasonable means of installation and a prototypal gyro are designed. The gyroscopic effect of the BVG is characterized through experiments. Experimental results show that the BVG has not only the advantages of low cost, low power, long work life, high sensitivity, and so on, but, also, of a simple structure and a better impact resistance property for low and medium angular velocity measurements.

  13. Characterization of the Bell-Shaped Vibratory Angular Rate Gyro

    Directory of Open Access Journals (Sweden)

    Junfang Fan

    2013-08-01

    Full Text Available The bell-shaped vibratory angular rate gyro (abbreviated as BVG is a novel shell vibratory gyroscope, which is inspired by the Chinese traditional bell. It sensitizes angular velocity through the standing wave precession effect. The bell-shaped resonator is a core component of the BVG and looks like the millimeter-grade Chinese traditional bell, such as QianLong Bell and Yongle Bell. It is made of Ni43CrTi, which is a constant modulus alloy. The exciting element, control element and detection element are uniformly distributed and attached to the resonator, respectively. This work presents the design, analysis and experimentation on the BVG. It is most important to analyze the vibratory character of the bell-shaped resonator. The strain equation, internal force and the resonator's equilibrium differential equation are derived in the orthogonal curvilinear coordinate system. When the input angular velocity is existent on the sensitive axis, an analysis of the vibratory character is performed using the theory of thin shells. On this basis, the mode shape function and the simplified second order normal vibration mode dynamical equation are obtained. The coriolis coupling relationship about the primary mode and secondary mode is established. The methods of the signal processing and control loop are presented. Analyzing the impact resistance property of the bell-shaped resonator, which is compared with other shell resonators using the Finite Element Method, demonstrates that BVG has the advantage of a better impact resistance property. A reasonable means of installation and a prototypal gyro are designed. The gyroscopic effect of the BVG is characterized through experiments. Experimental results show that the BVG has not only the advantages of low cost, low power, long work life, high sensitivity, and so on, but, also, of a simple structure and a better impact resistance property for low and medium angular velocity measurements.

  14. Evaluation of CP shape correction for e-beam writing

    Science.gov (United States)

    Takizawa, Masahiro; Bunya, Keita; Isobe, Hideaki; Komami, Hideaki; Abe, Kenji; Kurokawa, Masaki; Yamada, Akio; Sakamoto, Kiichi; Nakamura, Takayuki; Kuwano, Kazusumi; Tateishi, Masahiro; Chau, Larry

    2012-11-01

    Character projection (CP) exposure has some advantages compared with variable shaped beam (VSB) system; (1) shot count reduction by printing complex patterns in one e-beam shot, (2) high pattern fidelity by using CP stencil. In this paper we address another advantage of CP exposure, namely the shape correction of CP stencil for cancelling the pattern deformation on the substrate. The deformation of CP printings is decomposed into some elements. They are CP stencil manufacturing error, proximity effect, beam blur of the e-beam writer and resist blur. The element caused by beam blur of e-beam writer can be predicted by measuring the total beam blur obtained from CD-dose curves. The pattern deformation was corrected by applying the shape correction software system of D2S. The corrected CP stencil of 22nm-node standard cell was manufactured and standard cell patterns were exposed. We confirmed that our shape correction method is the appropriate solution for correcting deformation issue of CP openings. The beam blur required for the 1X nm dimensions was predicted from the exposure results of standard cell patterns with applying shape correction and CD-dose curves. We simulated the optical system to realize the required beam blur. As a result, the next electron optics has the resolving capability of 1X nm dimension.

  15. A theory of shape identification

    CERN Document Server

    Cao, Frédéric; Morel, Jean-Michel; Musé, Pablo; Sur, Frédéric

    2008-01-01

    Recent years have seen dramatic progress in shape recognition algorithms applied to ever-growing image databases. They have been applied to image stitching, stereo vision, image mosaics, solid object recognition and video or web image retrieval. More fundamentally, the ability of humans and animals to detect and recognize shapes is one of the enigmas of perception. The book describes a complete method that starts from a query image and an image database and yields a list of the images in the database containing shapes present in the query image. A false alarm number is associated to each detection. Many experiments will show that familiar simple shapes or images can reliably be identified with false alarm numbers ranging from 10-5 to less than 10-300. Technically speaking, there are two main issues. The first is extracting invariant shape descriptors from digital images. The second is deciding whether two shape descriptors are identifiable as the same shape or not. A perceptual principle, the Helmholtz princi...

  16. Collective Robotic Assembly of Discrete Lattice Elements (CRADLE)

    Data.gov (United States)

    National Aeronautics and Space Administration — CRADLE seeks to address this need through a novel application of an integrated robot-structure-material system based on discrete lattice construction using task...

  17. 14 CFR 217.5 - Data collected (data elements).

    Science.gov (United States)

    2010-01-01

    .... This code represents the industry designator as described in the appendix to § 217.10 of this part. A common private industry source of these industry designator codes is the Official Airline Guides (OAG... reporting the data. The carrier code is assigned by DOT. The Office of Airline Information (OAI'S) will...

  18. Two and three-dimensional stress analysis of continua using the UNCLE finite element scheme

    International Nuclear Information System (INIS)

    Richardson, T.

    1982-04-01

    A description of the data requirements for the solution of stress analysis problems in bodies of complex shape using finite elements is given. The elements available include quadratic isoparametric elements in two- and three-dimensions. In addition to solving problems involving elastic deformation, calculations may be performed which involve creep or plasticity. It is also possible to carry out vibrational analysis of structures to find the natural frequencies and the corresponding modal shapes. (author)

  19. Modified 37-element bundle dryout

    Energy Technology Data Exchange (ETDEWEB)

    Tahir, A., E-mail: ab.tahir@amec.com [AMEC NSS Ltd., Fuel and Fuel Channel Safety Analysis, Ontario (Canada); Parlatan, Y., E-mail: yuksel.parlatan@opg.com [Ontario Power Generation Inc., Nuclear Safety Projects, Ontario (Canada); Kwee, M., E-mail: marc.kwee@brucepower.com [Bruce Power., Nuclear Safety Analysis and Support, Ontario (Canada); Liauw, W., E-mail: wie.kiong.liauw@opg.com [Ontario Power Generation Inc., Nuclear Safety Projects, Ontario (Canada); Hadaller, G.; Fortman, R., E-mail: ghadaller@sternlab.com, E-mail: rfortman@sternlab.com [Stern Labs Inc., Hamilton, Ontario (Canada)

    2011-07-01

    The Heat Transport Systems (HTS) of the Canadian nuclear reactors are ageing. One of the effects of ageing is the non-uniform change in the dimension of the reactor pressure tubes through the mechanism of diametral creep. The mechanism has the global effect of increasing channel flows and decreasing the reactor header-to-header pressure drop. However, the increased flow is not distributed uniformly through the fuel bundle cross-section because the bundle tends to settle at the bottom of the pressure tube leaving a crescent shaped space on the top. This portion experiences the bulk of the increased flow, as it offers the path of least hydraulic resistance. As a result of this flow bypass, the coolant flows through some of the interior-subchannels of the fuel bundle are reduced. For a given flow, inlet temperature and exit pressure, flow bypass in the top of the channel reduces flow from the interior subchannels and consequently reduces the Critical Heat Flux (CHF). To recover some of the reduction in dryout power, OPG started a program in 2004 to examine possible modifications to the reference 37-element bundles that may result in an increase in dryout powers for the uncrept and crept pressure tube. Under accident conditions, where CHF is a concern, the ideal design is one where all fuel elements reach dryout at the same time. The ASSERT subchannel code was used to explore potential modifications to the 37-element bundle that may result in increased dryout powers in an uncrept and crept pressure tube. In addition analysis of post-dryout tests in 37-element bundle were examined to explore the potential of increasing the dryout power of the reference 37-element bundle by slightly modifying the bundle geometry. A small reduction of the centre element in the bundle was selected as an approach to enhance the dryout power of the bundle. CHF tests of the modified bundle were performed. The measurement confirmed that the modified bundle has higher dryout powers than the

  20. Shape reconstruction from gradient data.

    Science.gov (United States)

    Ettl, Svenja; Kaminski, Jürgen; Knauer, Markus C; Häusler, Gerd

    2008-04-20

    We present a generalized method for reconstructing the shape of an object from measured gradient data. A certain class of optical sensors does not measure the shape of an object but rather its local slope. These sensors display several advantages, including high information efficiency, sensitivity, and robustness. For many applications, however, it is necessary to acquire the shape, which must be calculated from the slopes by numerical integration. Existing integration techniques show drawbacks that render them unusable in many cases. Our method is based on an approximation employing radial basis functions. It can be applied to irregularly sampled, noisy, and incomplete data, and it reconstructs surfaces both locally and globally with high accuracy.

  1. The earth's shape and gravity

    CERN Document Server

    Garland, G D; Wilson, J T

    2013-01-01

    The Earth's Shape and Gravity focuses on the progress of the use of geophysical methods in investigating the interior of the earth and its shape. The publication first offers information on gravity, geophysics, geodesy, and geology and gravity measurements. Discussions focus on gravity measurements and reductions, potential and equipotential surfaces, absolute and relative measurements, and gravity networks. The text then elaborates on the shape of the sea-level surface and reduction of gravity observations. The text takes a look at gravity anomalies and structures in the earth's crust; interp

  2. Finite element modeling of lipid bilayer membranes

    Science.gov (United States)

    Feng, Feng; Klug, William S.

    2006-12-01

    A numerical simulation framework is presented for the study of biological membranes composed of lipid bilayers based on the finite element method. The classic model for these membranes employs a two-dimensional-fluid-like elastic constitutive law which is sensitive to curvature, and subjects vesicles to physically imposed constraints on surface area and volume. This model is implemented numerically via the use of C1-conforming triangular Loop subdivision finite elements. The validity of the framework is tested by computing equilibrium shapes from previously-determined axisymmetric shape-phase diagram of lipid bilayer vesicles with homogeneous material properties. Some of the benefits and challenges of finite element modeling of lipid bilayer systems are discussed, and it is indicated how this framework is natural for future investigation of biologically realistic bilayer structures involving nonaxisymmetric geometries, binding and adhesive interactions, heterogeneous mechanical properties, cytoskeletal interactions, and complex loading arrangements. These biologically relevant features have important consequences for the shape mechanics of nonidealized vesicles and cells, and their study requires not simply advances in theory, but also advances in numerical simulation techniques, such as those presented here.

  3. Elemental analysis of Uranouchi bay seabed sludge using PIXE

    International Nuclear Information System (INIS)

    Kabir, M. Hasnat; Narusawa, Tadashi; Nishiyama, Fumitaka; Sumi, Katsuhiro

    2006-01-01

    Elemental analyses were carried out for the seabed sludge collected from Uranouchi bay (Kochi, Japan) using Particle Induced X-ray Emission (PIXE). Seabed-sludge contamination with heavy metals as well as toxic elements becomes one of the most serious environmental problems. The aim of the present study is to investigate the polluted areas in the bay by heavy and toxic elements. As a results of analyses of samples collected from eleven different places in the bay, seventeen elements including toxic ones were detected. The results suggest that the center region of the bay is seriously contaminated by heavy and toxic elements in comparison with the other areas in the bay. (author)

  4. Shapes of agglomerates in plasma etching reactors

    International Nuclear Information System (INIS)

    Huang, F.Y.; Kushner, M.J.

    1997-01-01

    Dust particle contamination of wafers in reactive ion etching (RIE) plasma tools is a continuing concern in the microelectronics industry. It is common to find that particles collected on surfaces or downstream of the etch chamber are agglomerates of smaller monodisperse spherical particles. The shapes of the agglomerates vary from compact, high fractal dimension structures to filamentary, low fractal dimension structures. These shapes are important with respect to the transport of particles in RIE tools under the influence electrostatic and ion drag forces, and the possible generation of polarization forces. A molecular dynamics simulation has been developed to investigate the shapes of agglomerates in plasma etching reactors. We find that filamentary, low fractal dimension structures are generally produced by smaller (<100s nm) particles in low powered plasmas where the kinetic energy of primary particles is insufficient to overcome the larger Coulomb repulsion of a compact agglomerate. This is analogous to the diffusive regime in neutral agglomeration. Large particles in high powered plasmas generally produce compact agglomerates of high fractal dimension, analogous to ballistic agglomeration of neutrals. copyright 1997 American Institute of Physics

  5. Shape Statistics for Random Domains and Particles

    Science.gov (United States)

    Stoyan, Dietrich; Davtyan, Ashot; Turetayev, Daulet

    This paper surveys ideas of statistical analysis of planar images of particles such as powder particles or sand grains, domains such as monolayer domains on water or water droplets on planar surfaces and biological cells or vesicles. For a simple and fast discrimination between collectives of particles, shape ratios or indices such as `area:perimeter' ratio are powerful tools. A more detailed description is possible by means of various functions such as radius-vector function, tangent-angle function and erosion function. A deeper understanding of particle shape and size is possible by studying the relevant physical processes which generate them, such as fracture, abrasion and growth by aggregation. The second part of the paper discusses a particular stochastic model, called Gibbs pixel-particle. It produces two-dimensional connected lattice figures, often called lattice animals, the distribution of which depends on an energy function which is controled by particle area and boundary length and roughness. These pixel-particles vary in a broad spectrum of possible shapes and sizes.

  6. Modern quantum kinetic theory and spectral line shapes

    International Nuclear Information System (INIS)

    Monchick, L.

    1991-01-01

    The modern quantum kinetic theory of spectral line shapes is outlined and a typical calculation of a Raman scattered line shape described. The distinguishing feature of this calculation is that it was completely ab initio and therefore constituted a test of modern quantum kinetic theory, the state of the art in computing molecular-scattering cross sections, and novel methods of solving kinetic equations. The computation employed a large assortment of tools: group theory, finite-element methods, classic methods of solving coupled sets of ordinary differential equations, graph methods of combining angular momenta, and matrix methods of solving integral equations. Agreement with experimental results was excellent. 13 refs

  7. A comparison between different finite elements for elastic and aero-elastic analyses

    Directory of Open Access Journals (Sweden)

    Mohamed Mahran

    2017-11-01

    Full Text Available In the present paper, a comparison between five different shell finite elements, including the Linear Triangular Element, Linear Quadrilateral Element, Linear Quadrilateral Element based on deformation modes, 8-node Quadrilateral Element, and 9-Node Quadrilateral Element was presented. The shape functions and the element equations related to each element were presented through a detailed mathematical formulation. Additionally, the Jacobian matrix for the second order derivatives was simplified and used to derive each element’s strain-displacement matrix in bending. The elements were compared using carefully selected elastic and aero-elastic bench mark problems, regarding the number of elements needed to reach convergence, the resulting accuracy, and the needed computation time. The best suitable element for elastic free vibration analysis was found to be the Linear Quadrilateral Element with deformation-based shape functions, whereas the most suitable element for stress analysis was the 8-Node Quadrilateral Element, and the most suitable element for aero-elastic analysis was the 9-Node Quadrilateral Element. Although the linear triangular element was the last choice for modal and stress analyses, it establishes more accurate results in aero-elastic analyses, however, with much longer computation time. Additionally, the nine-node quadrilateral element was found to be the best choice for laminated composite plates analysis.

  8. Aging changes in body shape

    Science.gov (United States)

    ... MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Aging changes in body shape URL of this page: // ...

  9. Shape morphing Kirigami mechanical metamaterials.

    Science.gov (United States)

    Neville, Robin M; Scarpa, Fabrizio; Pirrera, Alberto

    2016-08-05

    Mechanical metamaterials exhibit unusual properties through the shape and movement of their engineered subunits. This work presents a new investigation of the Poisson's ratios of a family of cellular metamaterials based on Kirigami design principles. Kirigami is the art of cutting and folding paper to obtain 3D shapes. This technique allows us to create cellular structures with engineered cuts and folds that produce large shape and volume changes, and with extremely directional, tuneable mechanical properties. We demonstrate how to produce these structures from flat sheets of composite materials. By a combination of analytical models and numerical simulations we show how these Kirigami cellular metamaterials can change their deformation characteristics. We also demonstrate the potential of using these classes of mechanical metamaterials for shape change applications like morphing structures.

  10. Shape Deformations in Atomic Nuclei

    OpenAIRE

    Hamamoto, Ikuko; Mottelson, Ben R.

    2011-01-01

    The ground states of some nuclei are described by densities and mean fields that are spherical, while others are deformed. The existence of non-spherical shape in nuclei represents a spontaneous symmetry breaking.

  11. Shape optimization: Good looks and acoustics too!

    Science.gov (United States)

    D'Antonio, Peter; Cox, Trevor J.; Haas, Steve

    2003-04-01

    One of the challenges in the architectural acoustic design of museums and other public spaces is to develop contemporary scattering surfaces that complement contemporary architecture in the way that statuary, coffered ceilings, columns, and relief ornamentation complemented classic architecture. Often acoustic surfaces satisfy the acoustics, but may or may not satisfy the aesthetics. One approach that has been successful employs a combination of boundary element and multidimensional optimization techniques. The architect supplies the desired shape motif and the acoustician supplies the acoustical performance requirements. The optimization program then provides an Arcousthetic surface, which simultaneously satisfies the architecture, the acoustics, and the aesthetics. The program can be used with diffusive or diffsorptive surfaces. Photos of installations using these acoustic tools and a description of the design of the National Museum of the American Indian will also be presented to illustrate the usefulness of these devices and their impact on architectural acoustics.

  12. Shape Optimization of Wind Turbine Blades

    DEFF Research Database (Denmark)

    Wang, Xudong; Shen, Wen Zhong; Zhu, Wei Jun

    2009-01-01

    of the rotor. The design variables used in the current study are the blade shape parameters, including chord, twist and relative thickness. To validate the implementation of the aerodynamic/aero-elastic model, the computed aerodynamic results are compared to experimental data for the experimental rotor used......This paper presents a design tool for optimizing wind turbine blades. The design model is based on an aerodynamic/aero-elastic code that includes the structural dynamics of the blades and the Blade Element Momentum (BEM) theory. To model the main aero-elastic behaviour of a real wind turbine...... in the European Commision-sponsored project Model Experiments in Controlled Conditions, (MEXICO) and the computed aero-elastic results are examined against the FLEX code for flow post the Tjereborg 2 MW rotor. To illustrate the optimization technique, three wind turbine rotors of different sizes (the MEXICO 25 k...

  13. Static compliance of foundations of arbitrary shape

    International Nuclear Information System (INIS)

    Hejazi, M.; Nemat-Nasser, S.

    1982-01-01

    The calculation of the compliance matric of foundations is an essential first step in the static or dynamics analysis of soil-foundation interaction problems. An effective numerical method is presented for accurate computation of the static compliance of rigid foundations with arbitrary shapes, which rest on an elastic half-space and are subjected to vertical and horizontal loads, as well as tilting and torsional moments. In this method the contacting area is subbivided into a finite number of 'equivalent' circular elements, which leads to solutions in a rather simple form that require minimal numerical computations. The results are illustrated by calculating the overall compliances of foundations of various geometries, and these are compared with results obtained by means of another, more elaborate, method. (orig.)

  14. Molecular clusters of the main group elements

    CERN Document Server

    Driess, Matthias

    2008-01-01

    ""To summarize, Molecular Clusters of the Main Group Elements is certainly not a popular science book, nor is it a textbook; it is a very good, up-to-date collection of articles for the specialist. Als Fazit bleibt: Molecular Clusters of the Main Group Elements ist sicher kein populissenschaftliches Werk, auch kein Lehrbuch, aber eine gelungene, hoch aktuelle Zusammenstellung fen interessierten Fachmann."" -Michael Ruck, TU Dresden, Angewandte Chemie, 2004 - 116/36 + International Edition 2004 - 43/36

  15. Electrochromic fiber-shaped supercapacitors.

    Science.gov (United States)

    Chen, Xuli; Lin, Huijuan; Deng, Jue; Zhang, Ye; Sun, Xuemei; Chen, Peining; Fang, Xin; Zhang, Zhitao; Guan, Guozhen; Peng, Huisheng

    2014-12-23

    An electrochromic fiber-shaped super-capacitor is developed by winding aligned carbon nanotube/polyaniline composite sheets on an elastic fiber. The fiber-shaped supercapacitors demonstrate rapid and reversible chromatic transitions under different working states, which can be directly observed by the naked eye. They are also stretchable and flexible, and are woven into textiles to display designed signals in addition to storing energy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Shape changes in 101Pd

    International Nuclear Information System (INIS)

    Dinesh, S.; Carmel Vigila Bai, G.M.; Santhosh Kumar, S.; Anusha, B.

    2001-01-01

    In heavy ion collision compound nuclei can be formed with high excitation energies and with very high angular momenta. Most of these emphasize and discuss the structure effects, yrast traps etc. The spin degree of freedom inherently involves deformation and structural or shape changes. The shape of a nucleus should be very sensitive to the increase of its temperature. The increasing temperature affects the occupations of the single particle levels near the Fermi energy are investigated

  17. Elemental analysis using a handheld X-Ray fluorescence spectrometer

    Science.gov (United States)

    Groover, Krishangi D.; Izbicki, John

    2016-06-24

    The U.S. Geological Survey is collecting geologic samples from local stream channels, aquifer materials, and rock outcrops for studies of trace elements in the Mojave Desert, southern California. These samples are collected because geologic materials can release a variety of elements to the environment when exposed to water. The samples are to be analyzed with a handheld X-ray fluorescence (XRF) spectrometer to determine the concentrations of up to 27 elements, including chromium.

  18. Impact of phase errors at the conjugate step on the propagation of intensity and phase shaped laser beams

    CSIR Research Space (South Africa)

    Litvin, IA

    2007-01-01

    Full Text Available The authors investigate the phase conjugating element of a two element Fourier transform beam shaping scheme and the impact this element has on the resulting propagation. It is shown that there are stricter limitations placed on the system when...

  19. Content, Cost, Chance, and Collection

    OpenAIRE

    Lorenzen, Mark

    2007-01-01

    This Working Paper argues that the film industry is a paradigmatic example of how the organization of the cultural economy is shaped by balancing creativity with contextual issues. In the film industry, organization is far from determined only by creative concerns for content production: Issues of cost, chance and collection also play important roles. Through analyzing creativity and its context in the film industry, the paper explains the industry’s organization, and opens up for understandi...

  20. Numerical experiments on the determination of unsteady state temperature distribution in domains of complicated boundary shape

    International Nuclear Information System (INIS)

    Laura, P.A.A.

    1978-01-01

    This paper compares analytical and finite element results for an unsteady heat-conduction problem in simply and doubly connected plates of regular polygonal shape. A numerical solution is obtained by means of the powerful finite element method and the results are shown to agree with an approximate conformal mapping-variational technique previously developed by the first author and coworkers. (Auth.)

  1. From global to local statistical shape priors novel methods to obtain accurate reconstruction results with a limited amount of training shapes

    CERN Document Server

    Last, Carsten

    2017-01-01

    This book proposes a new approach to handle the problem of limited training data. Common approaches to cope with this problem are to model the shape variability independently across predefined segments or to allow artificial shape variations that cannot be explained through the training data, both of which have their drawbacks. The approach presented uses a local shape prior in each element of the underlying data domain and couples all local shape priors via smoothness constraints. The book provides a sound mathematical foundation in order to embed this new shape prior formulation into the well-known variational image segmentation framework. The new segmentation approach so obtained allows accurate reconstruction of even complex object classes with only a few training shapes at hand.

  2. Shape analysis in medical image analysis

    CERN Document Server

    Tavares, João

    2014-01-01

    This book contains thirteen contributions from invited experts of international recognition addressing important issues in shape analysis in medical image analysis, including techniques for image segmentation, registration, modelling and classification, and applications in biology, as well as in cardiac, brain, spine, chest, lung and clinical practice. This volume treats topics such as, anatomic and functional shape representation and matching; shape-based medical image segmentation; shape registration; statistical shape analysis; shape deformation; shape-based abnormity detection; shape tracking and longitudinal shape analysis; machine learning for shape modeling and analysis; shape-based computer-aided-diagnosis; shape-based medical navigation; benchmark and validation of shape representation, analysis and modeling algorithms. This work will be of interest to researchers, students, and manufacturers in the fields of artificial intelligence, bioengineering, biomechanics, computational mechanics, computationa...

  3. The synthetic elements

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    1990-05-01

    Prior to 1940, the heaviest element known was uranium, discovered in 1789. Since that time the elements 93 through 109 have been synthesized and identified and the elements 43, 61, 85, and 87 which were missing form the periodic tables of the 1930's have been discovered. The techniques and problems involved in these discoveries and the placement of the transuranium elements in the periodic table will be discussed. The production and positive identification of elements heavier than Md (Z=101), which have very short half-lives and can only be produced an atom-at-a-time, are very difficult and there have been controversies concerning their discovery. Some of the new methods which have been developed and used in these studies will be described. The prospects for production of still heavier elements will be considered

  4. The solar element

    DEFF Research Database (Denmark)

    Kragh, Helge

    2009-01-01

    of the nineteenth century. In the modest form of a yellow spectral line known as D3, 'helium' was sometimes supposed to exist in the Sun's atmosphere, an idea which is traditionally ascribed to J. Norman Lockyer. Did Lockyer discover helium as a solar element? How was the suggestion received by chemists, physicists...... and astronomers in the period until the spring of 1895, when William Ramsay serendipitously found the gas in uranium minerals? The hypothetical element helium was fairly well known, yet Ramsay's discovery owed little or nothing to Lockyer's solar element. Indeed, for a brief while it was thought that the two...... elements might be different. The complex story of how helium became established as both a solar and terrestrial element involves precise observations as well as airy speculations. It is a story that is unique among the discovery histories of the chemical elements....

  5. A Collective Model of Baryons

    International Nuclear Information System (INIS)

    Leviatan, Amiram

    1996-01-01

    We introduce a collective model of baryons which are interpreted as rotations and vibrations of an oblate-top shaped string. The underlying algebraic structure provides a tractable computational framework for comparing single-particle and collective forms of dynamics. We derive mass formulas as well as closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electro- and photoproduction. Effects of spin-flavor symmetry breaking and of swelling of hadrons with increasing excitation energy are considered. (author)

  6. The Pulley Element

    Directory of Open Access Journals (Sweden)

    Štekbauer Hynek

    2016-12-01

    Full Text Available The pulley is used in a number of structures for the mechanical advantage it gives. This paper presents an approach for the calculation of a pulley-cable system using a special pulley element in the finite element method. The Lagrange Multiplier method and Penalty method are used to define the pulley element, as described in this paper. Both approaches are easy to implement in general FEM codes.

  7. The Pulley Element

    OpenAIRE

    Štekbauer Hynek

    2016-01-01

    The pulley is used in a number of structures for the mechanical advantage it gives. This paper presents an approach for the calculation of a pulley-cable system using a special pulley element in the finite element method. The Lagrange Multiplier method and Penalty method are used to define the pulley element, as described in this paper. Both approaches are easy to implement in general FEM codes.

  8. Elements in biological AMS

    International Nuclear Information System (INIS)

    Vogel, J.S.; McAninch, J.; Freeman, S.

    1996-08-01

    AMS (Accelerator Mass Spectrometry) provides high detection sensitivity for isotopes whose half-lives are between 10 years and 100 million years. 14 C is the most developed of such isotopes and is used in tracing natural and anthropogenic organic compounds in the Earth's biosphere. Thirty-three elements in the main periodic table and 17 lanthanides or actinides have long lived isotopes, providing potential tracers for research in elemental biochemistry. Overlap of biologically interesting heavy elements and possible AMS tracers is discussed

  9. Fuel element loading system

    International Nuclear Information System (INIS)

    Arya, S.P; s.

    1978-01-01

    A nuclear fuel element loading system is described which conveys a plurality of fuel rods to longitudinal passages in fuel elements. Conveyor means successively position the fuel rods above the longitudinal passages in axial alignment therewith and adapter means guide the fuel rods from the conveyor means into the longitudinal passages. The fuel elements are vibrated to cause the fuel rods to fall into the longitudinal passages through the adapter means

  10. Triple shape memory effect of star-shaped polyurethane.

    Science.gov (United States)

    Yang, Xifeng; Wang, Lin; Wang, Wenxi; Chen, Hongmei; Yang, Guang; Zhou, Shaobing

    2014-05-14

    In this study, we synthesized one type of star-shaped polyurethane (SPU) with star-shaped poly(ε-caprolactone) (SPCL) containing different arm numbers as soft segment and 4,4'-diphenyl methane diisocyanate (MDI) as well as chain extender 1,4-butylene glycol (BDO) as hard segment. Proton nuclear magnetic resonance (1H-NMR) confirmed the chemical structure of the material. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) results indicated that both the melting temperature (Tm) and transition temperature (Ttrans) of SPU decreased with the hard segment composition increase. X-ray diffraction (XRD) results demonstrated that the increase of the crystallinity of SPU following the raised arm numbers endowed a high shape fixity of six-arm star-shaped polyurethane (6S-PU) and a wide melting temperature range, which resulted in an excellent triple-shape memory effect of 6S-PU. The in vitro cytotoxicity assay evaluated with osteoblasts through Alamar blue assay demonstrates that this copolymer possessed good cytocompatibility. This material can be potentially used as a new smart material in the field of biomaterials.

  11. Modeling of mechanical properties for ferrous shape memory alloy

    International Nuclear Information System (INIS)

    Wada, Manabu; Ide, Yusuke; Mizote, Shinichiro; Naoi, Hisashi; Tsukimori, Kazuyuki

    2002-08-01

    In order to acquire technical data that are necessary for manufacture and design of the simulation test device for analyzing the core mechanics of Fast Breeder Reactor, ferrous shape memory alloy of Fe-28%Mn-6%Si-5%Cr is melted, forged and heat-treated. The microstructures are austenite. The specimens are deformed of up to 16% work-strain by tensile and compressive test, resulting in appearance of epsilon-martensite that is induced by stress. Then, heating at 673K for 10 minutes causes austenitic transformation from epsilon-martensite and shape memory strains are measured. We also investigate shape memory character of specimens, which are given, so called 'training treatment' of 5% pre-strain and recovery heat treatment. As a result, there is little difference between tensile and compressive test without training treatment and shape memory strain is 2% after being given 5% work-strain and recovery heat treatment. On the other hand, training treatment is remarkable and shape memory strain reaches to 3.7% after 5% work-strain. We analyze shape recovery character of this alloy specimen at three-point bending by using finite element method, and indicate possibility that its deformation behavior can be estimated from mechanical properties' data obtained at tensile and compressive test. (author)

  12. The morphing properties of a vascular shape memory composite

    International Nuclear Information System (INIS)

    Cortes, P; Kubas, G; Terzak, J; Phillips, D; Baur, J W

    2014-01-01

    This work investigates the fabrication, experimentation, testing, and modeling of shape memory composites consisting of two-way shape memory alloy (SMA) tubes embedded in a shape memory polymer (SMP) matrix. The hybrid system here investigated is thermally activated via internal transport of thermal fluids through the SMA vascular system. The resulting shape memory composite (SMC) combines the high modulus and high specific actuation force of SMAs with the strong shape fixing and variable stiffness of SMPs to create a light-weight composite capable of controllably and rapidly achieving two shape memory states. Specifically, a 25° thermally induced out-of-plane bending state is achieved with a 2% volume fraction of SMA in the composite after 2 min of being activated by an internal thermal fluid. Here, while the thermal structural design of the SMC was not optimized and the thermal cycling was significantly restricted by the low thermal conduction of the SMP, the deflection of the composite was within 20% of the expected value modeled by the thermal–mechanical finite element analysis (FEA) here performed. The close agreement between the experimental performance and the modeled composite response suggests that morphing composites based on SMAs and SMPs are promising structures for adaptive applications. (paper)

  13. Strategic design and fabrication of acrylic shape memory polymers

    Science.gov (United States)

    Park, Ju Hyuk; Kim, Hansu; Ryoun Youn, Jae; Song, Young Seok

    2017-08-01

    Modulation of thermomechanics nature is a critical issue for an optimized use of shape memory polymers (SMPs). In this study, a strategic approach was proposed to control the transition temperature of SMPs. Free radical vinyl polymerization was employed for tailoring and preparing acrylic SMPs. Transition temperatures of the shape memory tri-copolymers were tuned by changing the composition of monomers. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analyses were carried out to evaluate the chemical structures and compositions of the synthesized SMPs. The thermomechanical properties and shape memory performance of the SMPs were also examined by performing dynamic mechanical thermal analysis. Numerical simulation based on a finite element method provided consistent results with experimental cyclic shape memory tests of the specimens. Transient shape recovery tests were conducted and optical transparence of the samples was identified. We envision that the materials proposed in this study can help develop a new type of shape-memory devices in biomedical and aerospace engineering applications.

  14. Mutual Coupling Reduction of E-Shaped MIMO Antenna with Matrix of C-Shaped Resonators

    Directory of Open Access Journals (Sweden)

    Raghad Ghalib Saadallah Alsultan

    2018-01-01

    Full Text Available E-shaped multiple-input-multiple-output (MIMO microstrip antenna systems operating in WLAN and WiMAX bands (between 5 and 7.5 GHz are proposed with enhanced isolation features. The systems are comprised of two antennas that are placed parallel and orthogonal to each other, respectively. According to the simulation results, the operating frequency of the MIMO antenna system is 6.3 GHz, and mutual coupling is below −18 dB in a parallel arrangement, whereas they are 6.4 GHz and −25 dB, respectively, in the orthogonal arrangement. The 2 × 3 matrix of C-shaped resonator (CSR is proposed and placed between the antenna elements over the substrate, to reduce the mutual coupling and enhance the isolation between the antennas. More than 30 dB isolation between the array elements is achieved at the resonant frequency for both of the configurations. The essential parameters of the MIMO array such as mutual coupling, surface current distribution, envelop correlation coefficient (ECC, diversity gain (DG, and the total efficiency have been simulated to verify the reliability and the validity of the MIMO system in both parallel and orthogonal configurations. The experimental results are also provided and compared for the mutual coupling with simulated results. An adequate match between the measured and simulated results is achieved.

  15. Shape memory polymer foams for endovascular therapies

    Science.gov (United States)

    Wilson, Thomas S [Castro Valley, CA; Maitland, Duncan J [Pleasant Hill, CA

    2012-03-13

    A system for occluding a physical anomaly. One embodiment comprises a shape memory material body wherein the shape memory material body fits within the physical anomaly occluding the physical anomaly. The shape memory material body has a primary shape for occluding the physical anomaly and a secondary shape for being positioned in the physical anomaly.

  16. Shape memory polymer foams for endovascular therapies

    Science.gov (United States)

    Wilson, Thomas S.; Maitland, Duncan J.

    2015-05-26

    A system for occluding a physical anomaly. One embodiment comprises a shape memory material body wherein the shape memory material body fits within the physical anomaly occluding the physical anomaly. The shape memory material body has a primary shape for occluding the physical anomaly and a secondary shape for being positioned in the physical anomaly.

  17. Collective Success or Collective Failure?

    DEFF Research Database (Denmark)

    Fayyaz, Anjum

    In this article, I make a contribution to the literature on how industrial clusters in developing countries respond to corporate responsibility demands from international buyers in Europe and North America. I outline an analytical framework that integrates insights from the global value chain, in...... of innovation, and government failure - can partly explain why Sialkot has been marginalized in terms of its overall share of world football manufacturing in the last decade....... study of soccer village project to learn how various attempts at facilitating joint CSR action in the Pakistani football manufacturing have consistently failed in addressing international CSR compliance demands. I conclude that this form of collective failure – along with technological changes, lack...

  18. Automatic Method for Building Indoor Boundary Models from Dense Point Clouds Collected by Laser Scanners

    Directory of Open Access Journals (Sweden)

    Enrique Valero

    2012-11-01

    Full Text Available In this paper we present a method that automatically yields Boundary Representation Models (B-rep for indoors after processing dense point clouds collected by laser scanners from key locations through an existing facility. Our objective is particularly focused on providing single models which contain the shape, location and relationship of primitive structural elements of inhabited scenarios such as walls, ceilings and floors. We propose a discretization of the space in order to accurately segment the 3D data and generate complete B-rep models of indoors in which faces, edges and vertices are coherently connected. The approach has been tested in real scenarios with data coming from laser scanners yielding promising results. We have deeply evaluated the results by analyzing how reliably these elements can be detected and how accurately they are modeled.

  19. Automatic Method for Building Indoor Boundary Models from Dense Point Clouds Collected by Laser Scanners

    Science.gov (United States)

    Valero, Enrique; Adán, Antonio; Cerrada, Carlos

    2012-01-01

    In this paper we present a method that automatically yields Boundary Representation Models (B-rep) for indoors after processing dense point clouds collected by laser scanners from key locations through an existing facility. Our objective is particularly focused on providing single models which contain the shape, location and relationship of primitive structural elements of inhabited scenarios such as walls, ceilings and floors. We propose a discretization of the space in order to accurately segment the 3D data and generate complete B-rep models of indoors in which faces, edges and vertices are coherently connected. The approach has been tested in real scenarios with data coming from laser scanners yielding promising results. We have deeply evaluated the results by analyzing how reliably these elements can be detected and how accurately they are modeled. PMID:23443369

  20. Chemistry of superheavy elements

    International Nuclear Information System (INIS)

    Schaedel, M.

    2012-01-01

    The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

  1. Reflected pulse damping between charge source and shaping line

    International Nuclear Information System (INIS)

    Bukharov, V.F.; Gerasimov, A.I.; Fedotkin, A.S.

    1987-01-01

    A coaxial device to tranfer electric energy from a pulsed generator to a low-impedance shaping line whose commutation brings about powerful short voltage pulses is described. To damp pulses the internal conductor of the device is enveloped by the element of volumetrically resitant material, and controlled discharge are placed between the external conductor of the device and the element. The device operated efficiency when the radical lines were charged from the Arkadiev-Marx generator during 1 μs up to 500 kV

  2. Social transformation, collective categories and identity change

    OpenAIRE

    Todd, Jennifer

    2005-01-01

    Changes in collective categories of identity are at the core of social transformation. The causal linkages between identity change, institutional change and change in modes of practice are, however, complex. Developing and adapting ideas from Pierre Bourdieu’s work, this article shows the coexistence in tension of a plurality of elements – in particular oppositional and non-oppositional elements - within each collective identity category. On this basis, it proposes a typology of logically pos...

  3. SHAPE FROM TEXTURE USING LOCALLY SCALED POINT PROCESSES

    Directory of Open Access Journals (Sweden)

    Eva-Maria Didden

    2015-09-01

    Full Text Available Shape from texture refers to the extraction of 3D information from 2D images with irregular texture. This paper introduces a statistical framework to learn shape from texture where convex texture elements in a 2D image are represented through a point process. In a first step, the 2D image is preprocessed to generate a probability map corresponding to an estimate of the unnormalized intensity of the latent point process underlying the texture elements. The latent point process is subsequently inferred from the probability map in a non-parametric, model free manner. Finally, the 3D information is extracted from the point pattern by applying a locally scaled point process model where the local scaling function represents the deformation caused by the projection of a 3D surface onto a 2D image.

  4. Orthodontic applications of a superelastic shape-memory alloy model

    International Nuclear Information System (INIS)

    Glendenning, R.W.; Enlow, R.L.

    2000-01-01

    During orthodontic treatment, dental appliances (braces) made of shape memory alloys have the potential to provide nearly uniform low level stresses to dentitions during tooth movement over a large range of tooth displacement. In this paper we model superelastic behaviour of dental appliances using the finite element method and constitutive equations developed by F. Auricchio et al. Results of the mathematical model for 3-point bending and several promising 'closing loop' designs are compared with laboratory results for the same configurations. (orig.)

  5. Statistical models of shape optimisation and evaluation

    CERN Document Server

    Davies, Rhodri; Taylor, Chris

    2014-01-01

    Deformable shape models have wide application in computer vision and biomedical image analysis. This book addresses a key issue in shape modelling: establishment of a meaningful correspondence between a set of shapes. Full implementation details are provided.

  6. Cold Forming of Ni-Ti Shape Memory Alloy Sheet

    Science.gov (United States)

    Fann, Kaung-Jau; Su, Jhe-Yung

    2018-03-01

    Ni-Ti shape memory alloy has two specific properties, superelasiticity and shape memory effect, and thus is widely applied in diverse industries. To extend its further application, this study attempts to investigate the feasibility of cold forming its sheet blank especially under a bi-axial tensile stress state. Not only experiments but also a Finite Element Analysis (FEA) with DEFORM 2D was conducted in this study. The material data for FEA was accomplished by the tensile test. An Erichsen-like cupping test was performed as well to determine the process parameter for experiment setup. As a result of the study, the Ni-Ti shape memory alloy sheet has a low formability for cold forming and shows a relative large springback after releasing the forming load.

  7. Shape memory polymers: three-dimensional isotropic modeling

    Science.gov (United States)

    Balogun, Olaniyi; Mo, Changki

    2014-04-01

    This paper presents a comprehensive three-dimensional isotropic numerical simulation for a thermo-mechanical constitutive model of shape memory polymers (SMPs). In order to predict the thermo-mechanical behavior of SMPs, a one-dimensional rheological thermo-mechanical constitutive model is adopted, translated into a three-dimensional form and a time discrete form of the three-dimensional model is then presented. Numerical simulation of this model was developed using the UMAT subroutine capabilities of the finite element software ABAQUS. Evolution of the analysis was conducted by making use of the backward difference scheme, which was applied to all quantities within the model, including the material properties. A comparison of the numerical simulation results was carried out with the available experimental data. Numerical simulation results clearly exhibit the thermo-mechanical properties of the material which include shape fixity, shape recovery, and recovery stress. Finally, a prediction for the transverse and shear directions of the material is presented.

  8. How Positioning Shapes Opportunities for Student Agency in Schools

    Science.gov (United States)

    York, Adam; Kirshner, Ben

    2015-01-01

    This chapter shows how student positioning by adults shapes opportunities for students to learn collective systemic agency including practices such as organizing others, developing a systemic analysis, and taking action in complex institutions, such as schools. We argue that these learning opportunities are expanded when education professionals…

  9. Shape Modeling of a Concentric-tube Continuum Robot

    DEFF Research Database (Denmark)

    Bai, Shaoping; Xing, Charles Chuhao

    2012-01-01

    Concentric-tube continuum robots feature with simple and compact structures and have a great potential in medical applications. The paper is concerned with the shape modeling of a type of concentric-tube continuum robot built with a collection of super-elastic NiTiNol tubes. The mechanics...

  10. Quantum Shape-Phase Transitions in Finite Nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.

    2007-01-01

    Quantum shape-phase transitions in finite nuclei are considered in the framework of the interacting boson model. Critical-point Hamiltonians for first- and second-order transitions are identified by resolving them into intrinsic and collective parts. Suitable wave functions and finite-N estimates for observables at the critical-points are derived

  11. Quantum Shape-Phase Transitions in Finite Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)

    2007-05-15

    Quantum shape-phase transitions in finite nuclei are considered in the framework of the interacting boson model. Critical-point Hamiltonians for first- and second-order transitions are identified by resolving them into intrinsic and collective parts. Suitable wave functions and finite-N estimates for observables at the critical-points are derived.

  12. Berkeley new element program

    International Nuclear Information System (INIS)

    Ghiorso, A.

    1975-09-01

    The work done with element 106 is reviewed, and a new experiment which bears on the properties of the isotope of mass 260 with atomic number 104 is discussed. It is noted that in the case of element 106 a link is demonstrated to the granddaughter as well as the daughter

  13. Fuel element development

    Energy Technology Data Exchange (ETDEWEB)

    Muehling, G.

    1983-01-01

    The studies concerning breeders for the development of fuel elements carried out in Karlsruhe aim at: - optimization of fuel, - support of fuel rod and fuel element concepts from steady-state and field irradiation experiments and their evaluation, and - developing appropriate cladding and structural material and its adaptation to the requirements of high-output breeder reactors.

  14. Seagrass leaf element content

    NARCIS (Netherlands)

    Vonk, J.A.; Smulders, Fee O.H.; Christianen, Marjolijn J.A.; Govers, Laura L.

    2017-01-01

    Knowledge on the role of seagrass leaf elements and in particular micronutrients and their ranges is limited. We present a global database, consisting of 1126 unique leaf values for ten elements, obtained from literature and unpublished data, spanning 25 different seagrass species from 28 countries.

  15. Proceedings of transuranium elements

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The identification of the first synthetic elements was established by chemical evidence. Conclusive proof of the synthesis of the first artificial element, technetium, was published in 1937 by Perrier and Segre. An essential aspect of their achievement was the prediction of the chemical properties of element 43, which had been missing from the periodic table and which was expected to have properties similar to those of manganese and rhenium. The discovery of other artificial elements, astatine and francium, was facilitated in 1939-1940 by the prediction of their chemical properties. A little more than 50 years ago, in the spring of 1940, Edwin McMillan and Philip Abelson synthesized element 93, neptunium, and confirmed its uniqueness by chemical means. On August 30, 1940, Glenn Seaborg, Arthur Wahl, and the late Joseph Kennedy began their neutron irradiations of uranium nitrate hexahydrate. A few months later they synthesized element 94, later named plutonium, by observing the alpha particles emitted from uranium oxide targets that had been bombarded with deuterons. Shortly thereafter they proved that is was the second transuranium element by establishing its unique oxidation-reduction behavior. The symposium honored the scientists and engineers whose vision and dedication led to the discovery of the transuranium elements and to the understanding of the influence of 5f electrons on their electronic structure and bonding. This volume represents a record of papers presented at the symposium

  16. Characterization of Fine Airborne Particulate Collected in Tokyo and Major Atmospheric Emission Sources by Using Single Particle Measurement of SEM-EDX

    Science.gov (United States)

    Sato, K.; Iijima, A.; Furuta, N.

    2008-12-01

    In our long-term monitoring of size-classified Airborne Particulate Matter (APM) in Tokyo since 1995, it had been demonstrated that toxic elements such as As, Se, Cd, Sb and Pb were extremely enriched in fine APM (PM2.5). However, in that study, total sampled APM on a filter was digested with acids, and thus only averaged elemental composition in fine APM could be obtained. One of the effective methods to determine the origin of APM is single particle measurement by using SEM-EDX. By using characteristic shapes observed by SEM and marker elements contained in APM measured by EDX, detailed information for source identification can be obtained. In this study, fine APM (PM2.5) was collected at various locations such as roadside, diesel vehicle exhaust, a heavy oil combustion plant and a waste incineration plant as well as ambient atmosphere in Tokyo, and characteristics of fine particles that will be utilized for identification of emission sources are elucidated. Fine particles can be classified into 3 main characteristic shape groups; edge-shaped, cotton-like and spherical. Shape of particles collected in a heavy oil combustion plant and a waste incineration plant was mostly spherical, and these particles may be associated with thermal process. Diesel exhaust particles were predominantly cotton-like which may consist of coagulated nano-sized particles. Most of brake abrasion dusts were edge-shaped, which may be associated with mechanical abrasion of brake pads. In the elemental analysis of fine particles, high concentrations of Sb, Cu, Ti and Ba were detected in brake abrasion dusts. Since these elements are major constituents of brake pads, these can be used for marker elements of brake abrasion dusts. High concentration of C was detected in diesel exhaust particles and oil combustion particles, and thus C can be used for marker elements of their origin. Furthermore, high concentrations of C, Ca and K were detected in fly ash from a waste incineration plant, which

  17. Finite element analysis of soil-sheet pile interaction

    Science.gov (United States)

    Nyby, D. W.

    A finite element model which accurately and economically models soil-sheet pile structures was developed. The model was used to analyze cantilever and anchored sheet pile walls. The finite element model includes transition and interface elements. The transition element has the capability of conforming to the displaced shape of the sheet pile elements on one side (cubic element) and soil elements on the other sides (bilinear element). The interface element models the frictional resistance between the soil and the sheet pile. It behaves elastically below a threshold force level (Coulomb friction) and perfectly plastic above this value. The soil is modeled using nonlinear constitutive relations. These relations are used for both the transition elements and the bilinear elements. The economy of the finite element model was increased in two ways. Closed-form integration was used to reduce the computational effort and an equation solver was used which takes advantage of the banded, symmetric, and positive-definite characteristics of the global stiffness matrix.

  18. Comparison of Test and Finite Element Analysis for Two Full-Scale Helicopter Crash Tests

    Science.gov (United States)

    Annett, Martin S.; Horta,Lucas G.

    2011-01-01

    Finite element analyses have been performed for two full-scale crash tests of an MD-500 helicopter. The first crash test was conducted to evaluate the performance of a composite deployable energy absorber under combined flight loads. In the second crash test, the energy absorber was removed to establish the baseline loads. The use of an energy absorbing device reduced the impact acceleration levels by a factor of three. Accelerations and kinematic data collected from the crash tests were compared to analytical results. Details of the full-scale crash tests and development of the system-integrated finite element model are briefly described along with direct comparisons of acceleration magnitudes and durations for the first full-scale crash test. Because load levels were significantly different between tests, models developed for the purposes of predicting the overall system response with external energy absorbers were not adequate under more severe conditions seen in the second crash test. Relative error comparisons were inadequate to guide model calibration. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used for the second full-scale crash test. The calibrated parameter set reduced 2-norm prediction error by 51% but did not improve impact shape orthogonality.

  19. A Shape Memory Alloy Based Cryogenic Thermal Conduction Switch

    International Nuclear Information System (INIS)

    Krishnan, V.B.; Singh, J.D.; Woodruff, T.R.; Vaidyanathan, R.; Notardonato, W.U.

    2004-01-01

    Shape memory alloys (SMAs) can produce large strains when deformed (e.g., up to 8%). Heating results in a phase transformation and associated recovery of all the accumulated strain. This strain recovery can occur against large forces, resulting in their use as actuators. Thus an SMA element can integrate both sensory and actuation functions, by inherently sensing a change in temperature and actuating by undergoing a shape change as a result of a temperature-induced phase transformation. Two aspects of our work on cryogenic SMAs are addressed here. First - a shape memory alloy based cryogenic thermal conduction switch for operation between dewars of liquid methane and liquid oxygen in a common bulkhead arrangement is discussed. Such a switch integrates the sensor element and the actuator element and can be used to create a variable thermal sink to other cryogenic tanks for liquefaction, densification, and zero boil-off systems for advanced spaceport applications. Second - fabrication via arc-melting and subsequent materials testing of SMAs with cryogenic transformation temperatures for use in the aforementioned switch is discussed

  20. Shapes formed by interacting cracks

    Science.gov (United States)

    Daniels, Karen

    2012-02-01

    Brittle failure through multiple cracks occurs in a wide variety of contexts, from microscopic failures in dental enamel and cleaved silicon to geological faults and planetary ice crusts. In each of these situations, with complicated stress geometries and different microscopic mechanisms, pairwise interactions between approaching cracks nonetheless produce characteristically curved fracture paths. We investigate the origins of this widely observed ``en passant'' crack pattern by fracturing a rectangular slab which is notched on each long side and subjected to quasi-static uniaxial strain from the short side. The two cracks propagate along approximately straight paths until they pass each other, after which they curve and release a lens-shaped fragment. We find that, for materials with diverse mechanical properties, each curve has an approximately square-root shape, and that the length of each fragment is twice its width. We are able to explain the origins of this universal shape with a simple geometrical model.