Conformal geometry and quasiregular mappings
Vuorinen, Matti
1988-01-01
This book is an introduction to the theory of spatial quasiregular mappings intended for the uninitiated reader. At the same time the book also addresses specialists in classical analysis and, in particular, geometric function theory. The text leads the reader to the frontier of current research and covers some most recent developments in the subject, previously scatterd through the literature. A major role in this monograph is played by certain conformal invariants which are solutions of extremal problems related to extremal lengths of curve families. These invariants are then applied to prove sharp distortion theorems for quasiregular mappings. One of these extremal problems of conformal geometry generalizes a classical two-dimensional problem of O. Teichmüller. The novel feature of the exposition is the way in which conformal invariants are applied and the sharp results obtained should be of considerable interest even in the two-dimensional particular case. This book combines the features of a textbook an...
Differential geometry curves, surfaces, manifolds
Kohnel, Wolfgang
2002-01-01
This carefully written book is an introduction to the beautiful ideas and results of differential geometry. The first half covers the geometry of curves and surfaces, which provide much of the motivation and intuition for the general theory. Special topics that are explored include Frenet frames, ruled surfaces, minimal surfaces and the Gauss-Bonnet theorem. The second part is an introduction to the geometry of general manifolds, with particular emphasis on connections and curvature. The final two chapters are insightful examinations of the special cases of spaces of constant curvature and Einstein manifolds. The text is illustrated with many figures and examples. The prerequisites are undergraduate analysis and linear algebra.
Geometry of surfaces a practical guide for mechanical engineers
Radzevich, Stephen P
2012-01-01
Presents an in-depth analysis of geometry of part surfaces and provides the tools for solving complex engineering problems Geometry of Surfaces: A Practical Guide for Mechanical Engineers is a comprehensive guide to applied geometry of surfaces with focus on practical applications in various areas of mechanical engineering. The book is divided into three parts on Part Surfaces, Geometry of Contact of Part Surfaces and Mapping of the Contacting Part Surfaces. Geometry of Surfaces: A Practical Guide for Mechanical Engineers combines differential geometry and gearing theory and presents new developments in the elementary theory of enveloping surfaces. Written by a leading expert of the field, this book also provides the reader with the tools for solving complex engineering problems in the field of mechanical engineering. Presents an in-depth analysis of geometry of part surfaces Provides tools for solving complex engineering problems in the field of mechanical engineering Combines differential geometry an...
Geometry and topology of wild translation surfaces
Randecker, Anja
2016-01-01
A translation surface is a two-dimensional manifold, equipped with a translation structure. It can be obtained by considering Euclidean polygons and identifying their edges via translations. The vertices of the polygons form singularities if the translation structure can not be extended to them. We study translation surfaces with wild singularities, regarding the topology (genus and space of ends), the geometry (behavior of the singularities), and how the topology and the geometry are related.
Impact damage reduction by structured surface geometry
DEFF Research Database (Denmark)
Kusano, Yukihiro; Fedorov, Vladimir; McGugan, Malcolm
2018-01-01
performance was observed for polyurethane-coated fibre composites with structured geometries at the back surfaces. Repeated impacts by rubber balls on the coated side caused damage and delamination of the coating. The laminates with structured back surfaces showed longer durability than those with a flat back...
Geometry of curves and surfaces with Maple
Rovenski, Vladimir
2000-01-01
This concise text on geometry with computer modeling presents some elementary methods for analytical modeling and visualization of curves and surfaces. The author systematically examines such powerful tools as 2-D and 3-D animation of geometric images, transformations, shadows, and colors, and then further studies more complex problems in differential geometry. Well-illustrated with more than 350 figures---reproducible using Maple programs in the book---the work is devoted to three main areas: curves, surfaces, and polyhedra. Pedagogical benefits can be found in the large number of Maple programs, some of which are analogous to C++ programs, including those for splines and fractals. To avoid tedious typing, readers will be able to download many of the programs from the Birkhauser web site. Aimed at a broad audience of students, instructors of mathematics, computer scientists, and engineers who have knowledge of analytical geometry, i.e., method of coordinates, this text will be an excellent classroom resource...
Geometry of infinite planar maps with high degrees
DEFF Research Database (Denmark)
Budd, Timothy George; Curien, Nicolas
2017-01-01
We study the geometry of infinite random Boltzmann planar maps with vertices of high degree. These correspond to the duals of the Boltzmann maps associated to a critical weight sequence (qk)k≥0 for the faces with polynomial decay k-ɑ with ɑ ∈ (3/2,5/2)which have been studied by Le Gall & Miermont...
Intrinsic geometry of biological surface growth
Todd, Philip H
1986-01-01
1.1 General Introduction The work which comprises this essay formed part of a multidiscip linary project investigating the folding of the developing cerebral cortex in the ferret. The project as a whole combined a study, at the histological level, of the cytoarchitectural development concom itant with folding and a mathematical study of folding viewed from the perspective of differential geometry. We here concentrate on the differential geometry of brain folding. Histological results which have some significance to the geometry of the cortex are re ferred to, but are not discussed in any depth. As with any truly multidisciplinary work, this essay has objectives which lie in each of its constituent disciplines. From a neuroana tomical point of view, the work explores the use of the surface geo metry of the developing cortex as a parameter for the underlying growth process. Geometrical parameters of particular interest and theoretical importance are surface curvatures. Our experimental portion reports...
Differential geometry of curves and surfaces
Banchoff, Thomas F
2010-01-01
Students and professors of an undergraduate course in differential geometry will appreciate the clear exposition and comprehensive exercises in this book that focuses on the geometric properties of curves and surfaces, one- and two-dimensional objects in Euclidean space. The problems generally relate to questions of local properties (the properties observed at a point on the curve or surface) or global properties (the properties of the object as a whole). Some of the more interesting theorems explore relationships between local and global properties. A special feature is the availability of accompanying online interactive java applets coordinated with each section. The applets allow students to investigate and manipulate curves and surfaces to develop intuition and to help analyze geometric phenomena.
Capillary condensation in a square geometry with surface fields.
Zubaszewska, M; Gendiar, A; Drzewiński, A
2012-12-01
We study the influence of wetting on capillary condensation for a simple fluid in a square geometry with surface fields, where the reference system is an infinitely long slit. The corner transfer matrix renormalization group method has been extended to study a two-dimensional Ising model confined in an L × L geometry with equal surface fields. Our results have confirmed that in both geometries the coexistence line shift is governed by the same scaling powers, but their prefactors are different.
Replication of micro and nano surface geometries
DEFF Research Database (Denmark)
Hansen, Hans Nørgaard; Hocken, R.J.; Tosello, Guido
2011-01-01
The paper describes the state-of-the-art in replication of surface texture and topography at micro and nano scale. The description includes replication of surfaces in polymers, metals and glass. Three different main technological areas enabled by surface replication processes are presented......: manufacture of net-shape micro/nano surfaces, tooling (i.e. master making), and surface quality control (metrology, inspection). Replication processes and methods as well as the metrology of surfaces to determine the degree of replication are presented and classified. Examples from various application areas...... are given including replication for surface texture measurements, surface roughness standards, manufacture of micro and nano structured functional surfaces, replicated surfaces for optical applications (e.g. optical gratings), and process chains based on combinations of repeated surface replication steps....
Costa, Manuel F.; Almeida, Jose B.
1989-02-01
We will describe in this communication a noncont act method of measuring surface profile, it does not require any surface preparation, and it can be used with a very large range of surfaces from highly reflecting to non reflecting ones and as complex as textile surfaces. This method is reasonably immune to dispersion and diffraction, which usually make very difficult the application of non contact profilometry methods to a wide range of materials and situations, namely on quality control systems in industrial production lines. The method is based on the horizontal shift of the bright spot on a horizontal surface when this is illuminated with an oblique beam and moved vertically. in order to make the profilometry the sample is swept by an oblique light beam and the bright spot position is compared with a reference position. The bright spot must be as small as possible, particularly in very irregular surfaces; so the light beam diameter must be as small as possible and the incidence angle must not be too small. The sensivity of a system based on this method will be given, mostly, by the reception optical system.
Stabilizing embedology: Geometry-preserving delay-coordinate maps
Eftekhari, Armin; Yap, Han Lun; Wakin, Michael B.; Rozell, Christopher J.
2018-02-01
Delay-coordinate mapping is an effective and widely used technique for reconstructing and analyzing the dynamics of a nonlinear system based on time-series outputs. The efficacy of delay-coordinate mapping has long been supported by Takens' embedding theorem, which guarantees that delay-coordinate maps use the time-series output to provide a reconstruction of the hidden state space that is a one-to-one embedding of the system's attractor. While this topological guarantee ensures that distinct points in the reconstruction correspond to distinct points in the original state space, it does not characterize the quality of this embedding or illuminate how the specific parameters affect the reconstruction. In this paper, we extend Takens' result by establishing conditions under which delay-coordinate mapping is guaranteed to provide a stable embedding of a system's attractor. Beyond only preserving the attractor topology, a stable embedding preserves the attractor geometry by ensuring that distances between points in the state space are approximately preserved. In particular, we find that delay-coordinate mapping stably embeds an attractor of a dynamical system if the stable rank of the system is large enough to be proportional to the dimension of the attractor. The stable rank reflects the relation between the sampling interval and the number of delays in delay-coordinate mapping. Our theoretical findings give guidance to choosing system parameters, echoing the tradeoff between irrelevancy and redundancy that has been heuristically investigated in the literature. Our initial result is stated for attractors that are smooth submanifolds of Euclidean space, with extensions provided for the case of strange attractors.
Cloaking of 2D particle geometries in a surface medium
Energy Technology Data Exchange (ETDEWEB)
Alexopoulos, A., E-mail: Aris.Alexopoulos@dsto.defence.gov.au [Electronic Warfare and Radar Division, Defence Science and Technology Organisation (DSTO), PO Box 1500, Edinburgh 5111 (Australia); Yau, K.S.B. [Electronic Warfare and Radar Division, Defence Science and Technology Organisation (DSTO), PO Box 1500, Edinburgh 5111 (Australia)
2013-06-17
We theoretically examine the cloaking condition for two-dimensional particles with varying geometry embedded inside a surface medium. General solutions are obtained for multi-layer particle configurations with either all positive or partially negative constitutive parameters respectively. Cloaking of particle geometries that are large relative to the incident wavelength is demonstrated. Theoretical predictions are compared to full-wave numerical simulations for arrays of particles consisting of different geometries.
Mapping stellar surface features
International Nuclear Information System (INIS)
Noah, P.V.
1987-01-01
New photometric and spectroscopic observations of the RS Canum Venaticorum binaries Sigma Geminorum and UX Arietis are reported along with details of the Doppler-imaging program SPOTPROF. The observations suggest that the starspot activity on Sigma Gem has decreased to 0.05 magnitude in two years. A photometric spot model for September 1984 to January 1985 found that a single spot covering 2% of the surface and 1000 K cooler than the surrounding photosphere could model the light variations. Equivalent-width observations contemporaneous with the photometric observations did not show any significant variations. Line-profile models from SPOTPROF predict that the variation of the equivalent width of the 6393 A Fe I line should be ∼ 1mA. Photometric observations of UX Ari from January 1984 to March 1985 show an 0.3 magnitude variation indicating a large spot group must cover the surface. Contemporaneous spectroscopic observations show asymmetric line profiles. The Doppler imaging and the photometric light-curve models were used in an iterative method to describe the stellar surface-spot distribution and successfully model both the photometric and the spectroscopic variations
Differential geometry of curves and surfaces
Tapp, Kristopher
2016-01-01
This is a textbook on differential geometry well-suited to a variety of courses on this topic. For readers seeking an elementary text, the prerequisites are minimal and include plenty of examples and intermediate steps within proofs, while providing an invitation to more excursive applications and advanced topics. For readers bound for graduate school in math or physics, this is a clear, concise, rigorous development of the topic including the deep global theorems. For the benefit of all readers, the author employs various techniques to render the difficult abstract ideas herein more understandable and engaging. Over 300 color illustrations bring the mathematics to life, instantly clarifying concepts in ways that grayscale could not. Green-boxed definitions and purple-boxed theorems help to visually organize the mathematical content. Color is even used within the text to highlight logical relationships. Applications abound! The study of conformal and equiareal functions is grounded in its application to carto...
GPU-accelerated depth map generation for X-ray simulations of complex CAD geometries
Grandin, Robert J.; Young, Gavin; Holland, Stephen D.; Krishnamurthy, Adarsh
2018-04-01
Interactive x-ray simulations of complex computer-aided design (CAD) models can provide valuable insights for better interpretation of the defect signatures such as porosity from x-ray CT images. Generating the depth map along a particular direction for the given CAD geometry is the most compute-intensive step in x-ray simulations. We have developed a GPU-accelerated method for real-time generation of depth maps of complex CAD geometries. We preprocess complex components designed using commercial CAD systems using a custom CAD module and convert them into a fine user-defined surface tessellation. Our CAD module can be used by different simulators as well as handle complex geometries, including those that arise from complex castings and composite structures. We then make use of a parallel algorithm that runs on a graphics processing unit (GPU) to convert the finely-tessellated CAD model to a voxelized representation. The voxelized representation can enable heterogeneous modeling of the volume enclosed by the CAD model by assigning heterogeneous material properties in specific regions. The depth maps are generated from this voxelized representation with the help of a GPU-accelerated ray-casting algorithm. The GPU-accelerated ray-casting method enables interactive (> 60 frames-per-second) generation of the depth maps of complex CAD geometries. This enables arbitrarily rotation and slicing of the CAD model, leading to better interpretation of the x-ray images by the user. In addition, the depth maps can be used to aid directly in CT reconstruction algorithms.
Intrinsic and extrinsic geometry of random surfaces
International Nuclear Information System (INIS)
Jonsson, T.
1992-01-01
We prove that the extrinsic Hausdorff dimension is always greater than or equal to the intrinsic Hausdorff dimension in models of triangulated random surfaces with action which is quadratic in the separation of vertices. We furthermore derive a few naive scaling relations which relate the intrinsic Hausdorff dimension to other critical exponents. These relations suggest that the intrinsic Hausdorff dimension is infinite if the susceptibility does not diverge at the critical point. (orig.)
Self-dual geometry of generalized Hermitian surfaces
International Nuclear Information System (INIS)
Arsen'eva, O E; Kirichenko, V F
1998-01-01
Several results on the geometry of conformally semiflat Hermitian surfaces of both classical and hyperbolic types (generalized Hermitian surfaces) are obtained. Some of these results are generalizations and clarifications of already known results in this direction due to Koda, Itoh, and other authors. They reveal some unexpected beautiful connections between such classical characteristics of conformally semiflat (generalized) Hermitian surfaces as the Einstein property, the constancy of the holomorphic sectional curvature, and so on. A complete classification of compact self-dual Hermitian RK-surfaces that are at the same time generalized Hopf manifolds is obtained. This provides a complete solution of the Chen problem in this class of Hermitian surfaces
Investigation of Surface Phenomena in Shocked Tin in Converging Geometry
Energy Technology Data Exchange (ETDEWEB)
Rousculp, Christopher L. [Los Alamos National Laboratory; Oro, David Michael [Los Alamos National Laboratory; Griego, Jeffrey Randall [Los Alamos National Laboratory; Turchi, Peter John [Los Alamos National Laboratory; Reinovsky, Robert Emil [Los Alamos National Laboratory; Bradley, Joseph Thomas [Los Alamos National Laboratory; Cheng, Baolian [Los Alamos National Laboratory; Freeman, Matthew Stouten [Los Alamos National Laboratory; Patten, Austin Randall [Los Alamos National Laboratory
2016-03-21
There is great interest in the behavior of the free surface of tin under shock loading. While it is known that meso-scale surface imperfections can seed the Richtmyer- Meshkov Instability (RMI) for a surface that is melted on release, much less is known about a tin surface that is solid, but plastically deforming. Here material properties such as shear and yield strength come into play especially in converging geometry. Previous experiments have been driven by direct contact HE. Usually a thin, flat target coupon is fielded with various single-mode, sinusoidal, machined, profiles on the free surface. The free surface is adjacent to either vacuum or an inert receiver gas. Most of these previous driver/target configurations have been nominal planer geometry. With modern HE it has been straightforward to shock tin into melt on release. However it has been challenging to achieve a low enough pressure for solid state on release. Here we propose to extend the existing base of knowledge to include the behavior of the free surface of tin in cylindrical converging geometry. By shock loading a cylindrical tin shell with a magnetically driven cylindrical liner impactor, the free surface evolution can be diagnosed with proton radiography. With the PHELIX capacitor bank, the drive can easily be varied to span the pressure range to achieve solid, mixed, and liquid states on release. A conceptual cylindrical liner and target is shown in Figure 1.
Corrected body surface potential mapping.
Krenzke, Gerhard; Kindt, Carsten; Hetzer, Roland
2007-02-01
In the method for body surface potential mapping described here, the influence of thorax shape on measured ECG values is corrected. The distances of the ECG electrodes from the electrical heart midpoint are determined using a special device for ECG recording. These distances are used to correct the ECG values as if they had been measured on the surface of a sphere with a radius of 10 cm with its midpoint localized at the electrical heart midpoint. The equipotential lines of the electrical heart field are represented on the virtual surface of such a sphere. It is demonstrated that the character of a dipole field is better represented if the influence of the thorax shape is reduced. The site of the virtual reference electrode is also important for the dipole character of the representation of the electrical heart field.
Sossinsky, A B
2012-01-01
The book is an innovative modern exposition of geometry, or rather, of geometries; it is the first textbook in which Felix Klein's Erlangen Program (the action of transformation groups) is systematically used as the basis for defining various geometries. The course of study presented is dedicated to the proposition that all geometries are created equal--although some, of course, remain more equal than others. The author concentrates on several of the more distinguished and beautiful ones, which include what he terms "toy geometries", the geometries of Platonic bodies, discrete geometries, and classical continuous geometries. The text is based on first-year semester course lectures delivered at the Independent University of Moscow in 2003 and 2006. It is by no means a formal algebraic or analytic treatment of geometric topics, but rather, a highly visual exposition containing upwards of 200 illustrations. The reader is expected to possess a familiarity with elementary Euclidean geometry, albeit those lacking t...
Indian Academy of Sciences (India)
. In the previous article we looked at the origins of synthetic and analytic geometry. More practical minded people, the builders and navigators, were studying two other aspects of geometry- trigonometry and integral calculus. These are actually ...
Prasolov, V V
2015-01-01
This book provides a systematic introduction to various geometries, including Euclidean, affine, projective, spherical, and hyperbolic geometries. Also included is a chapter on infinite-dimensional generalizations of Euclidean and affine geometries. A uniform approach to different geometries, based on Klein's Erlangen Program is suggested, and similarities of various phenomena in all geometries are traced. An important notion of duality of geometric objects is highlighted throughout the book. The authors also include a detailed presentation of the theory of conics and quadrics, including the theory of conics for non-Euclidean geometries. The book contains many beautiful geometric facts and has plenty of problems, most of them with solutions, which nicely supplement the main text. With more than 150 figures illustrating the arguments, the book can be recommended as a textbook for undergraduate and graduate-level courses in geometry.
Surface geometry of 5D black holes and black rings
International Nuclear Information System (INIS)
Frolov, Valeri P.; Goswami, Rituparno
2007-01-01
We discuss geometrical properties of the horizon surface of five-dimensional rotating black holes and black rings. Geometrical invariants characterizing these 3D geometries are calculated. We obtain a global embedding of the 5D rotating black horizon surface into a flat space. We also describe the Kaluza-Klein reduction of the black ring solution (along the direction of its rotation) which, though it is nakedly singular, relates this solution to the 4D metric of a static black hole distorted by the presence of external scalar (dilaton) and vector ('electromagnetic') fields. The properties of the reduced black hole horizon and its embedding in E 3 are briefly discussed
Integrable mappings via rational elliptic surfaces
International Nuclear Information System (INIS)
Tsuda, Teruhisa
2004-01-01
We present a geometric description of the QRT map (which is an integrable mapping introduced by Quispel, Roberts and Thompson) in terms of the addition formula of a rational elliptic surface. By this formulation, we classify all the cases when the QRT map is periodic; and show that its period is 2, 3, 4, 5 or 6. A generalization of the QRT map which acts birationally on a pencil of K3 surfaces, or Calabi-Yau manifolds, is also presented
Nonabelian Jacobian of projective surfaces geometry and representation theory
Reider, Igor
2013-01-01
The Jacobian of a smooth projective curve is undoubtedly one of the most remarkable and beautiful objects in algebraic geometry. This work is an attempt to develop an analogous theory for smooth projective surfaces - a theory of the nonabelian Jacobian of smooth projective surfaces. Just like its classical counterpart, our nonabelian Jacobian relates to vector bundles (of rank 2) on a surface as well as its Hilbert scheme of points. But it also comes equipped with the variation of Hodge-like structures, which produces a sheaf of reductive Lie algebras naturally attached to our Jacobian. This constitutes a nonabelian analogue of the (abelian) Lie algebra structure of the classical Jacobian. This feature naturally relates geometry of surfaces with the representation theory of reductive Lie algebras/groups. This work’s main focus is on providing an in-depth study of various aspects of this relation. It presents a substantial body of evidence that the sheaf of Lie algebras on the nonabelian Jacobian is an effic...
Mapped Fourier Methods for stiff problems in toroidal geometry
Guillard , Herve
2014-01-01
Fourier spectral or pseudo-spectral methods are usually extremely efficient for periodic problems. However this efficiency is lost if the solutions have zones of rapid variations or internal layers. For these cases, a large number of Fourier modes are required and this makes the Fourier method unpractical in many cases. This work investigates the use of mapped Fourier method as a way to circumvent this problem. Mapped Fourier method uses instead of the usual Fourier interpolant the compositio...
Influence of slip-surface geometry on earth-flow deformation, Montaguto earth flow, southern Italy
Guerriero, L.; Coe, Jeffrey A.; Revellio, P.; Grelle, G.; Pinto, F.; Guadagno, F.
2016-01-01
We investigated relations between slip-surface geometry and deformational structures and hydrologic features at the Montaguto earth flow in southern Italy between 1954 and 2010. We used 25 boreholes, 15 static cone-penetration tests, and 22 shallow-seismic profiles to define the geometry of basal- and lateral-slip surfaces; and 9 multitemporal maps to quantify the spatial and temporal distribution of normal faults, thrust faults, back-tilted surfaces, strike-slip faults, flank ridges, folds, ponds, and springs. We infer that the slip surface is a repeating series of steeply sloping surfaces (risers) and gently sloping surfaces (treads). Stretching of earth-flow material created normal faults at risers, and shortening of earth-flow material created thrust faults, back-tilted surfaces, and ponds at treads. Individual pairs of risers and treads formed quasi-discrete kinematic zones within the earth flow that operated in unison to transmit pulses of sediment along the length of the flow. The locations of strike-slip faults, flank ridges, and folds were not controlled by basal-slip surface topography but were instead dependent on earth-flow volume and lateral changes in the direction of the earth-flow travel path. The earth-flow travel path was strongly influenced by inactive earth-flow deposits and pre-earth-flow drainages whose positions were determined by tectonic structures. The implications of our results that may be applicable to other earth flows are that structures with strikes normal to the direction of earth-flow motion (e.g., normal faults and thrust faults) can be used as a guide to the geometry of basal-slip surfaces, but that depths to the slip surface (i.e., the thickness of an earth flow) will vary as sediment pulses are transmitted through a flow.
Magnethohydrodynamic surface and body waves in rectangular and cylindrical geometries
International Nuclear Information System (INIS)
Donnelly, I.J.
1982-03-01
Low frequency magnetohydrodynamic (MHD) waves are studied in both rectangular slab and cylindrical geometry cavities containing low β plasmas. The plasma density distribution is modelled by an inner region of constant density surrounded by an outer region of lower density and a conducting boundary. The wave frequencies and fields are obtained as functions of the density distribution and the wavenumber components k(parall) and k(perp). The lowest frequency wave mode is a surface wave in which the wave fields decrease in magnitude with distance from the interface between the two plasma densities. It has the properties of a shear wave when k(perp)/k(parall) is either small or large but is compressive when k(perp) is approximately equal to k(parall). The surface wave does not exist when k(perp) = 0. Higher frequency modes have the properties of fast magnetosonic waves, at least in the inner density region
Pedoe, Dan
1988-01-01
""A lucid and masterly survey."" - Mathematics Gazette Professor Pedoe is widely known as a fine teacher and a fine geometer. His abilities in both areas are clearly evident in this self-contained, well-written, and lucid introduction to the scope and methods of elementary geometry. It covers the geometry usually included in undergraduate courses in mathematics, except for the theory of convex sets. Based on a course given by the author for several years at the University of Minnesota, the main purpose of the book is to increase geometrical, and therefore mathematical, understanding and to he
A nodal expansion method using conformal mapping for hexagonal geometry
International Nuclear Information System (INIS)
Chao, Y.A.; Shatilla, Y.A.
1993-01-01
Hexagonal nodal methods adopting the same transverse integration process used for square nodal methods face the subtle theoretical problem that this process leads to highly singular nonphysical terms in the diffusion equation. Lawrence, in developing the DIF3D-N code, tried to approximate the singular terms with relatively simple polynomials. In the HEX-NOD code, Wagner ignored the singularities to simplify the diffusion equation and introduced compensating terms in the nodal equations to restore the nodal balance relation. More recently developed hexagonal nodal codes, such as HEXPE-DITE and the hexagonal version of PANTHER, used methods similar to Wagner's. It will be shown that for light water reactor applications, these two different approximations significantly degraded the accuracy of the respective method as compared to the established square nodal methods. Alternatively, the method of conformal mapping was suggested to map a hexagon to a rectangle, with the unique feature of leaving the diffusion operator invariant, thereby fundamentally resolving the problems associated with transverse integration. This method is now implemented in the Westinghouse hexagonal nodal code ANC-H. In this paper we report on the results of comparing the three methods for a variety of problems via benchmarking against the fine-mesh finite difference code
Mapping Shape Geometry And Emotions Using Fuzzy Logic
DEFF Research Database (Denmark)
Achiche, Sofiane; Ahmed, Saeema
2008-01-01
An important aspect of artifact/product design is defining the aesthetic and emotional value. The success of a product is not only dependent on its functionality but also on the emotional value that it creates to its user. However, if several designers are faced with a task to create an object...... that would evoke a certain emotion (aggressive, soft, heavy, friendly, etc.), each would most likely interpret the emotion with a different set of geometric features and shapes. In this paper the authors propose an approach to formalize the relationship between geometric information of a 3D object...... and the intended emotion using fuzzy logic. To achieve this; 3D objects (shapes) created by design engineering students to match a set of words/emotions were analyzed. The authors identified geometric information as inputs of the fuzzy model and developed a set of fuzzy if/then rules to map the relationships...
Directory of Open Access Journals (Sweden)
Vakilabadi K.A.
2017-08-01
Full Text Available In this paper, infrared radiation exiting plain surfaces with different geometries is numerically simulated. Surfaces under consideration are assumed to have steady uniform heat generation inside. Moreover, the boundaries of the surfaces are considered to be at the surroundings temperature. Infrared radiation is calculated based on the temperature profile determined for the surface. The temperature profile of the surface is determined assuming the two dimensional heat conduction equations to govern the problem. The physical domain is transformed into the appropriate computational domain and the governing equation is mapped into the suitable forms in the new coordinate system of variables. After that the temperature profile of the surface is computed, the infrared radiation distribution of the surface is evaluated based on the equations given in the manuscript. The temperature profile as well as the IR images are given in the results section. It is concluded that the maximum value of infrared radiation of the surface occurs at the center. Moreover, it is concluded that among surfaces with equal areas, the one having the largest perimeter has the least value of IR at its center.
Quasilocal energy and surface geometry of Kerr spacetime
Yu, Chengjie; Liu, Jian-Liang
2017-04-01
We study the quasilocal energy (QLE) and the surface geometry for Kerr spacetime in the Boyer-Lindquist coordinates without taking the slow rotation approximation. We also consider in the region r ≤2 m , which is inside the ergosphere. For a certain region, r >rk(a ) , the Gaussian curvature of the surface with constant t , r is positive, and for r >√{3 }a the critical value of the QLE is positive. We found that the three curves: the outer horizon r =r+(a ), r =rk(a ) and r =√{3 }a intersect at the point a =√{3 }m /2 , which is the limit for the horizon to be isometrically embedded into R3. The numerical result indicates that the Kerr QLE is monotonically decreasing to the ADM m from the region inside the ergosphere to large r . Based on the second law of black hole dynamics, the QLE is increasing with respect to the irreducible mass Mir. From the results of Chen-Wang-Yau, we conclude that in a certain region, r >rh(a ), the critical value of the Kerr QLE is a global minimum.
Conformal mapping on Riemann surfaces
Cohn, Harvey
2010-01-01
The subject matter loosely called ""Riemann surface theory"" has been the starting point for the development of topology, functional analysis, modern algebra, and any one of a dozen recent branches of mathematics; it is one of the most valuable bodies of knowledge within mathematics for a student to learn.Professor Cohn's lucid and insightful book presents an ideal coverage of the subject in five pans. Part I is a review of complex analysis analytic behavior, the Riemann sphere, geometric constructions, and presents (as a review) a microcosm of the course. The Riemann manifold is introduced in
Filtering Color Mapped Textures and Surfaces
Heitz , Eric; Nowrouzezahrai , Derek; Poulin , Pierre; Neyret , Fabrice
2013-01-01
International audience; Color map textures applied directly to surfaces, to geometric microsurface details, or to procedural functions (such as noise), are commonly used to enhance visual detail. Their simplicity and ability to mimic a wide range of realistic appearances have led to their adoption in many rendering problems. As with any textured or geometric detail, proper filtering is needed to reduce aliasing when viewed across a range of distances, but accurate and efficient color map filt...
Complete Surface Mapping of ICF Shells
International Nuclear Information System (INIS)
Stephens, R.B.; Olson, D.; Huang, H.; Gibson, J.B.
2004-01-01
Inertial confinement fusion shells have previously been evaluated on the basis of microscopic examination for local defects and limited surface profiling to represent their average fluctuation power. Since defects are local, and don't always have visible edges, this approach both misses some important fluctuations and doesn't properly represent the spatially dependent surface fluctuation power. We have taken the first step toward correcting this problem by demonstrating the capability to completely map the surface of a NIF shell with the resolution to account for all modes. This allows complete accounting of all the surface fluctuations. In the future this capability could be used for valuable shells to generate a complete r(θ, φ) surface map for accurate 3-D modeling of a shot
COMPLETE SURFACE MAPPING OF ICF SHELLS
International Nuclear Information System (INIS)
STEPHENS, R.B.; OLSON, D.; HUANG, H.; GIBSON, J.B.
2003-09-01
OAK-B135 Inertial confinement fusion shells have previously been evaluated on the basis of microscopic examination for local defects and limited surface profiling to represent their average fluctuation power. Since defects are local, and don't always have visible edges, this approach both misses some important fluctuations and doesn't properly represent the spatially dependent surface fluctuation power. they have taken the first step toward correcting this problem by demonstrating the capability to completely map the surface of a NIF shell with the resolution to account for all modes. This allows complete accounting of all the surface fluctuations. In the future this capability could be used for valuable shells to generate a complete r(θ,ψ) surface map for accurate 3-D modeling of a shot
Effect of Geometry on Electrokinetic Characterization of Solid Surfaces.
Kumar, Abhijeet; Kleinen, Jochen; Venzmer, Joachim; Gambaryan-Roisman, Tatiana
2017-08-01
An analytical approach is presented to describe pressure-driven streaming current (I str ) and streaming potential (U str ) generation in geometrically complex samples, for which the classical Helmholtz-Smoluchowski (H-S) equation is known to be inaccurate. The new approach is valid under the same prerequisite conditions that are used for the development of the H-S equation, that is, the electrical double layers (EDLs) are sufficiently thin and surface conductivity and electroviscous effects are negligible. The analytical methodology is developed using linear velocity profiles to describe liquid flow inside of EDLs and using simplifying approximations to describe macroscopic flow. At first, a general expression is obtained to describe the I str generated in different cross sections of an arbitrarily shaped sample. Thereafter, assuming that the generated U str varies only along the pressure-gradient direction, an expression describing the variation of generated U str along the sample length is obtained. These expressions describing I str and U str generation constitute the theoretical foundation of this work, which is first applied to a set of three nonuniform cross-sectional capillaries and thereafter to a square array of cylindrical fibers (model porous media) for both parallel and transverse fiber orientation cases. Although analytical solutions cannot be obtained for real porous substrates because of their random structure, the new theory provides useful insights into the effect of important factors such as fiber orientation, sample porosity, and sample dimensions. The solutions obtained for the model porous media are used to device strategies for more accurate zeta potential determination of porous fiber plugs. The new approach could be thus useful in resolving the long-standing problem of sample geometry dependence of zeta potential measurements.
Low-dimensional geometry from euclidean surfaces to hyperbolic knots
Bonahon, Francis
2009-01-01
The study of 3-dimensional spaces brings together elements from several areas of mathematics. The most notable are topology and geometry, but elements of number theory and analysis also make appearances. In the past 30 years, there have been striking developments in the mathematics of 3-dimensional manifolds. This book aims to introduce undergraduate students to some of these important developments. Low-Dimensional Geometry starts at a relatively elementary level, and its early chapters can be used as a brief introduction to hyperbolic geometry. However, the ultimate goal is to describe the very recently completed geometrization program for 3-dimensional manifolds. The journey to reach this goal emphasizes examples and concrete constructions as an introduction to more general statements. This includes the tessellations associated to the process of gluing together the sides of a polygon. Bending some of these tessellations provides a natural introduction to 3-dimensional hyperbolic geometry and to the theory o...
Regional surface geometry of the rat stomach based on three-dimensional curvature analysis
Energy Technology Data Exchange (ETDEWEB)
Liao Donghua [Center of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital, DK-9100 Aalborg (Denmark); Zhao Jingbo [Center of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital, DK-9100 Aalborg (Denmark); Gregersen, Hans [Center of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital, DK-9100 Aalborg (Denmark)
2005-01-21
A better understanding of gastric accommodation and gastric perception requires knowledge of regional gastric geometry and local gastric tension throughout the stomach. An analytic method based on medical imaging data was developed in this study to describe the three-dimensional (3D) rat stomach geometry and tension distribution. The surface principal radii of curvatures were simulated and the surface tension was calculated in the glandular and non-glandular region of the stomach at pressures from 0 Pa to 800 Pa. The radii of curvature and tension distribution in the stomach were non-homogeneous. The radii of curvature in the glandular stomach were larger than those in the non-glandular region at pressures less than 100 Pa (P < 0.001). When the pressure increased to more than 200 Pa, the radii of curvature in the non-glandular stomach was larger than in the glandular stomach (P < 0.05). The curvature and tension distribution mapping using medical imaging technology and 3D models can be used to characterize and distinguish the physical behaviour in separate regions of the stomach.
Regional surface geometry of the rat stomach based on three-dimensional curvature analysis
International Nuclear Information System (INIS)
Liao Donghua; Zhao Jingbo; Gregersen, Hans
2005-01-01
A better understanding of gastric accommodation and gastric perception requires knowledge of regional gastric geometry and local gastric tension throughout the stomach. An analytic method based on medical imaging data was developed in this study to describe the three-dimensional (3D) rat stomach geometry and tension distribution. The surface principal radii of curvatures were simulated and the surface tension was calculated in the glandular and non-glandular region of the stomach at pressures from 0 Pa to 800 Pa. The radii of curvature and tension distribution in the stomach were non-homogeneous. The radii of curvature in the glandular stomach were larger than those in the non-glandular region at pressures less than 100 Pa (P < 0.001). When the pressure increased to more than 200 Pa, the radii of curvature in the non-glandular stomach was larger than in the glandular stomach (P < 0.05). The curvature and tension distribution mapping using medical imaging technology and 3D models can be used to characterize and distinguish the physical behaviour in separate regions of the stomach
Surfaces in classical geometries a treatment by moving frames
Jensen, Gary R; Nicolodi, Lorenzo
2016-01-01
Designed for intermediate graduate studies, this text will broaden students' core knowledge of differential geometry providing foundational material to relevant topics in classical differential geometry. The method of moving frames, a natural means for discovering and proving important results, provides the basis of treatment for topics discussed. Its application in many areas helps to connect the various geometries and to uncover many deep relationships, such as the Lawson correspondence. The nearly 300 problems and exercises range from simple applications to open problems. Exercises are embedded in the text as essential parts of the exposition. Problems are collected at the end of each chapter; solutions to select problems are given at the end of the book. Mathematica®, Matlab™, and Xfig are used to illustrate selected concepts and results. The careful selection of results serves to show the reader how to prove the most important theorems in the subject, which may become the foundation of future progress...
Investigation of Surface Phenomena in Shocked Tin in Converging Geometry
Energy Technology Data Exchange (ETDEWEB)
Rousculp, Christopher L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Oro, David Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Griego, Jeffrey Randall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Turchi, Peter John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reinovsky, Robert Emil [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bradley, Joseph Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cheng, Baolian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Freeman, Matthew Stouten [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Patten, Austin Randall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-04-14
There is a great interest in RMI as source of ejecta from metal shells. Previous experiments have explored wavelength amplitude (kA) variation but they have a small range of drive pressures and are in planer geometry. Simulations, both MD and hydro, have explored RMI in planer geometry. The ejecta source model from RMI is an area of active algorithm and code development in ASCI-IC Lagrangian Applications Project. PHELIX offers precise, reproducible variable driver for Hydro and material physics diagnoses with proton radiography.
International Nuclear Information System (INIS)
Kim, Jong Woon; Lee, Young Ouk
2016-01-01
When we use MCNP code for a deep shielding problem, we prefer to use variance reduction technique such as geometry splitting, or weight window, or source biasing to have relative error within reliable confidence interval. To generate importance map for geometry splitting in MCNP calculation, we should know the track entering number and previous importance on each cells since a new importance is calculated based on these information. If a problem is deep shielding problem such that we have zero tracks entering on a cell, we cannot generate new importance map. In this case, discrete ordinates code can provide information to generate importance map easily. In this paper, we use AETIUS code as a discrete ordinates code. Importance map for MCNP is generated based on a zone average flux of AETIUS calculation. The discretization of space, angle, and energy is not necessary for MCNP calculation. This is the big merit of MCNP code compared to the deterministic code. However, deterministic code (i.e., AETIUS) can provide a rough estimate of the flux throughout a problem relatively quickly. This can help MCNP by providing variance reduction parameters. Recently, ADVANTG code is released. This is an automated tool for generating variance reduction parameters for fixed-source continuous-energy Monte Carlo simulations with MCNP5 v1.60
Fermi surface mapping: Techniques and visualization
International Nuclear Information System (INIS)
Rotenberg, E.; Denlinger, J.D.; Kevan, S.D.
1997-01-01
Angle-resolved photoemission (ARP) of valence bands is a mature technique that has achieved spectacular success in band-mapping metals, semiconductors, and insulators. The purpose of the present study was the development of experimental and analytical techniques in ARP which take advantage of third generation light sources. Here the authors studied the relatively simple Cu surface in preparation for other metals. Copper and related metals themselves are of current interest, especially due to its role as an interlayer in spin valves and other magnetic heterostructures. A major goal of this study was the development of a systematic technique to quickly (i.e. in a few hours of synchrotron beamtime) measure the FS and separate it into bulk and surface FS's. Often, one needs to avoid bulk features altogether, which one can achieve by carefully mapping their locations in k-space. The authors will also show how they systematically map Fermi surfaces throughout large volumes of k-space, and, by processing the resulting volume data sets, provide intuitive pictures of FS's, both bulk and surface
ABOUT THE GEOMETRY AND THE APPLICATIONS OF THE TWISTED SURFACES
Directory of Open Access Journals (Sweden)
MÂRZA Carmen
2015-06-01
Full Text Available The helical and spiral surfaces are used in various fields. These surfaces are obtained by rotating a segment line called generatrix around directrices lines, respectively the spiral surfaces are obtained by composing simultaneously the movements of translation and rotation of a plane figure around an axis - which can be a straight line or a curved line, or around a real or imaginary surface - called core. After an overview of these surfaces, the attention of the authors will be focused on the geometrical and graphical analysis of the twisted surfaces in civil engineering branch, such as: columns, helical ramps and stairs, respectively buildings having a futuristic design.
Highly accurate surface maps from profilometer measurements
Medicus, Kate M.; Nelson, Jessica D.; Mandina, Mike P.
2013-04-01
Many aspheres and free-form optical surfaces are measured using a single line trace profilometer which is limiting because accurate 3D corrections are not possible with the single trace. We show a method to produce an accurate fully 2.5D surface height map when measuring a surface with a profilometer using only 6 traces and without expensive hardware. The 6 traces are taken at varying angular positions of the lens, rotating the part between each trace. The output height map contains low form error only, the first 36 Zernikes. The accuracy of the height map is ±10% of the actual Zernike values and within ±3% of the actual peak to valley number. The calculated Zernike values are affected by errors in the angular positioning, by the centering of the lens, and to a small effect, choices made in the processing algorithm. We have found that the angular positioning of the part should be better than 1?, which is achievable with typical hardware. The centering of the lens is essential to achieving accurate measurements. The part must be centered to within 0.5% of the diameter to achieve accurate results. This value is achievable with care, with an indicator, but the part must be edged to a clean diameter.
Euclid Mission: Mapping the Geometry of the Dark Universe. Mission and Consortium Status
Rhodes, Jason
2011-01-01
Euclid concept: (1) High-precision survey mission to map the geometry of the Dark Universe (2) Optimized for two complementary cosmological probes: (2a) Weak Gravitational Lensing (2b) Baryonic Acoustic Oscillations (2c) Additional probes: clusters, redshift space distortions, ISW (3) Full extragalactic sky survey with 1.2m telescope at L2: (3a) Imaging: (3a-1) High precision imaging at visible wavelengths (3a-2) Photometry/Imaging in the near-infrared (3b) Near Infrared Spectroscopy (4) Synergy with ground based surveys (5) Legacy science for a wide range of in astronomy
Rotating optical geometry sensor for inner pipe-surface reconstruction
Ritter, Moritz; Frey, Christan W.
2010-01-01
The inspection of sewer or fresh water pipes is usually carried out by a remotely controlled inspection vehicle equipped with a high resolution camera and a lightning system. This operator-oriented approach based on offline analysis of the recorded images is highly subjective and prone to errors. Beside the subjective classification of pipe defects through the operator standard closed circuit television (CCTV) technology is not suitable for detecting geometrical deformations resulting from e.g. structural mechanical weakness of the pipe, corrosion of e.g. cast-iron material or sedimentations. At Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB) in Karlsruhe, Germany, a new Rotating Optical Geometry Sensor (ROGS) for pipe inspection has been developed which is capable of measuring the inner pipe geometry very precisely over the whole pipe length. This paper describes the developed ROGS system and the online adaption strategy for choosing the optimal system parameters. These parameters are the rotation and traveling speed dependent from the pipe diameter. Furthermore, a practicable calibration methodology is presented which guarantees an identification of the several internal sensor parameters. ROGS has been integrated in two different systems: A rod based system for small fresh water pipes and a standard inspection vehicle based system for large sewer Pipes. These systems have been successfully applied to different pipe systems. With this measurement method the geometric information can be used efficiently for an objective repeatable quality evaluation. Results and experiences in the area of fresh water pipe inspection will be presented.
International Nuclear Information System (INIS)
Stoeger, W.R.; Whitman, A.P.; Knill, R.J.
1985-01-01
After showing that Rosen's bimetric theory of gravity is a harmonic map, the geometry of the ten-dimensional harmonic mapping space (HMS), and of its nine-dimensional symmetric submanifolds, which are the leaves of the codimension one foliation of the HMS, is detailed. Both structures are global affinely symmetric spaces. For each, the metric, connections, and Riemann, Ricci, and scalar curvatures are given. The Killing vectors in each case are also worked out and related to the ''conserved quantities'' naturally associated with the harmonic mapping character of the theory. The structure of the Rosen HMS is very much like that determined by the DeWitt metric on the six-dimensional Wheeler superspace of all positive definite three-dimensional metrics. It is clear that a slight modification of the Rosen HMS metric will yield the corresponding metric on the space of all four-dimensional metrics of Lorentz signature. Finally, interesting avenues of further research are indicated, particularly with respect to the structure and comparison of Lagrangian-based gravitational theories which are similar to Einstein's general relativity
Geometry, charge distribution, and surface speciation of phosphate on goethite.
Rahnemaie, R.; Hiemstra, T.; Riemsdijk, van W.H.
2007-01-01
The surface speciation of phosphate has been evaluated with surface complexation modeling using an interfacial charge distribution (CD) approach based on ion adsorption and ordering of interfacial water. In the CD model, the charge of adsorbed ions is distributed over two electrostatic potentials in
Impedance deduction for vegetated roof surfaces : multiple geometry strategy
Liu, C.; Hornikx, M.
2016-01-01
The transfer function method is an efficient procedure to deduce the ground surface impedance from short-range propagation measurements using one point source. It is able to provide a reasonable prediction of the surface impedance of a vegetated roof as well, and the characteristics of the vegetated
Three dimensional imaging of surface geometry in SEM
International Nuclear Information System (INIS)
Slowko, W.
1997-01-01
A great advantage of scanning electron microscopy (SEM) is its ability of the surface topography in the way as a human eye is accustomed to see lights and shadows on macroobjects. However, SEM's can hardly display vertical dimensions of the structures. One of possible solutions is reconstruction of the surface profiles by directional detection of secondary electrons and proper signal processing. However, the surface profile still gives two dimensional information and the method should be extended to obtain fully three dimensional imaging. The extension consists in a simultaneous reconstruction of the surface profiles in two perpendicular directions (x and y) and their superposition. The solution proposed is based on a quadrupole detector system and a computer or analogue system for signal processing. Quantitative data of the surface topography can be displayed in many manners in the system of two or three co-ordinates with use of pseudo-colour for the altitude coding. (author)
Two process chains for creating functional surfaces on mold for 3D geometry
DEFF Research Database (Denmark)
Zhang, Yang; Hansen, Hans Nørgaard; Pedersen, David Bue
. This paper describes and compares 2 approaches for fabricating micro- structured surfaces suitable for patterning of 3D shape cavity for injection moulding. The application investigated for the research is a part of a fixture for electrodes to be implanted inside human body. It is a ring with four wings......Polymer products with functional surfaces are applied in many fields such as medical and bio technology [1][2]. It is believed that certain types of micro- or nano- structured surfaces can enhance tissue anchoring [3]. However, most technologies for the fabrication of micro-structured functional...... surfaces are still limited to flat geometries or geometries with constant curvature [4] . Typically products that need micro structuring on the surface have a three dimensional and complex geometry. There are huge demand for investigation in establishing the micro structures on the surface of a 3D mold...
Bryant, N. A.; Zobrist, A. L.; Walker, R. E.; Gokhman, B.
1985-01-01
Performance requirements regarding geometric accuracy have been defined in terms of end product goals, but until recently no precise details have been given concerning the conditions under which that accuracy is to be achieved. In order to achieve higher spatial and spectral resolutions, the Thematic Mapper (TM) sensor was designed to image in both forward and reverse mirror sweeps in two separate focal planes. Both hardware and software have been augmented and changed during the course of the Landsat TM developments to achieve improved geometric accuracy. An investigation has been conducted to determine if the TM meets the National Map Accuracy Standards for geometric accuracy at larger scales. It was found that TM imagery, in terms of geometry, has come close to, and in some cases exceeded, its stringent specifications.
Diffusion accessibility as a method for visualizing macromolecular surface geometry.
Tsai, Yingssu; Holton, Thomas; Yeates, Todd O
2015-10-01
Important three-dimensional spatial features such as depth and surface concavity can be difficult to convey clearly in the context of two-dimensional images. In the area of macromolecular visualization, the computer graphics technique of ray-tracing can be helpful, but further techniques for emphasizing surface concavity can give clearer perceptions of depth. The notion of diffusion accessibility is well-suited for emphasizing such features of macromolecular surfaces, but a method for calculating diffusion accessibility has not been made widely available. Here we make available a web-based platform that performs the necessary calculation by solving the Laplace equation for steady state diffusion, and produces scripts for visualization that emphasize surface depth by coloring according to diffusion accessibility. The URL is http://services.mbi.ucla.edu/DiffAcc/. © 2015 The Protein Society.
Geometry of surfaces associated to Grassmannian sigma models
International Nuclear Information System (INIS)
Delisle, L; Hussin, V; Zakrzewski, W J
2015-01-01
We investigate the geometric characteristics of constant Gaussian curvature surfaces obtained from solutions of the G(m, n) sigma model. Most of these solutions are related to the Veronese sequence. We show that we can distinguish surfaces with the same Gaussian curvature using additional quantities like the topological charge and the mean curvature. The cases of G(1,n) = CP n-1 and G(2,n) are used to illustrate these characteristics. (paper)
Mapping the fine structure of cortical activity with different micro-ECoG electrode array geometries
Wang, Xi; Gkogkidis, C. Alexis; Iljina, Olga; Fiederer, Lukas D. J.; Henle, Christian; Mader, Irina; Kaminsky, Jan; Stieglitz, Thomas; Gierthmuehlen, Mortimer; Ball, Tonio
2017-10-01
Objective. Innovations in micro-electrocorticography (µECoG) electrode array manufacturing now allow for intricate designs with smaller contact diameters and/or pitch (i.e. inter-contact distance) down to the sub-mm range. The aims of the present study were: (i) to investigate whether frequency ranges up to 400 Hz can be reproducibly observed in µECoG recordings and (ii) to examine how differences in topographical substructure between these frequency bands and electrode array geometries can be quantified. We also investigated, for the first time, the influence of blood vessels on signal properties and assessed the influence of cortical vasculature on topographic mapping. Approach. The present study employed two µECoG electrode arrays with different contact diameters and inter-contact distances, which were used to characterize neural activity from the somatosensory cortex of minipigs in a broad frequency range up to 400 Hz. The analysed neural data were recorded in acute experiments under anaesthesia during peripheral electrical stimulation. Main results. We observed that µECoG recordings reliably revealed multi-focal cortical somatosensory response patterns, in which response peaks were often less than 1 cm apart and would thus not have been resolvable with conventional ECoG. The response patterns differed by stimulation site and intensity, they were distinct for different frequency bands, and the results of functional mapping proved independent of cortical vascular. Our analysis of different frequency bands exhibited differences in the number of activation peaks in topographical substructures. Notably, signal strength and signal-to-noise ratios differed between the two electrode arrays, possibly due to their different sensitivity for variations in spatial patterns and signal strengths. Significance. Our findings that the geometry of µECoG electrode arrays can strongly influence their recording performance can help to make informed decisions that maybe
Sorption Energy Maps of Clay Mineral Surfaces
International Nuclear Information System (INIS)
Cygan, Randall T.; Kirkpatrick, R. James
1999-01-01
A molecular-level understanding of mineral-water interactions is critical for the evaluation and prediction of the sorption properties of clay minerals that may be used in various chemical and radioactive waste disposal methods. Molecular models of metal sorption incorporate empirical energy force fields, based on molecular orbital calculations and spectroscopic data, that account for Coulombic, van der Waals attractive, and short-range repulsive energies. The summation of the non-bonded energy terms at equally-spaced grid points surrounding a mineral substrate provides a three dimensional potential energy grid. The energy map can be used to determine the optimal sorption sites of metal ions on the exposed surfaces of the mineral. By using this approach, we have evaluated the crystallographic and compositional control of metal sorption on the surfaces of kaolinite and illite. Estimates of the relative sorption energy and most stable sorption sites are derived based on a rigid ion approximation
Geometry- and rate-dependent adhesive failure of micropatterned surfaces
Bakker, H.; Lindstrom, S.B.; Sprakel, J.H.B.
2012-01-01
The dynamic nature of adhesive interface failure remains poorly understood, especially when the contact between the two surfaces is localized in microscopic points of adhesion. Here, we explore the dynamic failure of adhesive interfaces composed of a large number of micron-sized pillars against
Plateau diffusion coefficient for arbitrary flux surface geometry
International Nuclear Information System (INIS)
Meier, H.K.; Hirshman, S.P.; Sigmar, D.J.; Lao, L.L.
1981-03-01
A relatively simple but accurate representation has been developed for magnetic flux surfaces; it is valid for finite β and it describes configurations with both ellipticity and D-shape. This representation has been applied to the computation of the diffusion coefficient in the plateau regime
Majeed, Khaqan; Sorour, Sameh; Al-Naffouri, Tareq Y.; Valaee, Shahrokh
2015-01-01
The Received Signal Strength (RSS) based fingerprinting approaches for indoor localization pose a need for updating the fingerprint databases due to dynamic nature of the indoor environment. This process is hectic and time-consuming when the size of the indoor area is large. The semi-supervised approaches reduce this workload and achieve good accuracy around 15% of the fingerprinting load but the performance is severely degraded if it is reduced below this level. We propose an indoor localization framework that uses unsupervised manifold alignment. It requires only 1% of the fingerprinting load, some crowd sourced readings and plan coordinates of the indoor area. The 1% fingerprinting load is used only in perturbing the local geometries of the plan coordinates. The proposed framework achieves less than 5m mean localization error, which is considerably better than semi-supervised approaches at very small amount of fingerprinting load. In addition, the few location estimations together with few fingerprints help to estimate the complete radio map of the indoor environment. The estimation of radio map does not demand extra workload rather it employs the already available information from the proposed indoor localization framework. The testing results for radio map estimation show almost 50% performance improvement by using this information as compared to using only fingerprints.
Majeed, Khaqan
2015-12-22
The Received Signal Strength (RSS) based fingerprinting approaches for indoor localization pose a need for updating the fingerprint databases due to dynamic nature of the indoor environment. This process is hectic and time-consuming when the size of the indoor area is large. The semi-supervised approaches reduce this workload and achieve good accuracy around 15% of the fingerprinting load but the performance is severely degraded if it is reduced below this level. We propose an indoor localization framework that uses unsupervised manifold alignment. It requires only 1% of the fingerprinting load, some crowd sourced readings and plan coordinates of the indoor area. The 1% fingerprinting load is used only in perturbing the local geometries of the plan coordinates. The proposed framework achieves less than 5m mean localization error, which is considerably better than semi-supervised approaches at very small amount of fingerprinting load. In addition, the few location estimations together with few fingerprints help to estimate the complete radio map of the indoor environment. The estimation of radio map does not demand extra workload rather it employs the already available information from the proposed indoor localization framework. The testing results for radio map estimation show almost 50% performance improvement by using this information as compared to using only fingerprints.
About the geometry of the Earth geodetic reference surfaces
Husár, Ladislav; Švaral, Peter; Janák, Juraj
2017-10-01
The paper focuses on the comparison of metrics of three most common reference surfaces of the Earth used in geodesy (excluding the plane which also belongs to reference surfaces used in geodesy when dealing with small areas): a sphere, an ellipsoid of revolution and a triaxial ellipsoid. The two latter surfaces are treated in a more detailed way. First, the mathematical form of the metric tensors using three types of coordinates is derived and the lengths of meridian and parallel arcs between the two types of ellipsoids are compared. Three kinds of parallels, according to the type of latitude, can be defined on a triaxial ellipsoid. We show that two types of parallels are spatial curves and one is represented by ellipses. The differences of curvature of both kinds of ellipsoid are analysed using the normal curvature radii. Priority of the chosen triaxial ellipsoid is documented by its better fit with respect to the high-degree geoid model EIGEN6c4 computed up to degree and order 2160.
Spinning geometry = Twisted geometry
International Nuclear Information System (INIS)
Freidel, Laurent; Ziprick, Jonathan
2014-01-01
It is well known that the SU(2)-gauge invariant phase space of loop gravity can be represented in terms of twisted geometries. These are piecewise-linear-flat geometries obtained by gluing together polyhedra, but the resulting geometries are not continuous across the faces. Here we show that this phase space can also be represented by continuous, piecewise-flat three-geometries called spinning geometries. These are composed of metric-flat three-cells glued together consistently. The geometry of each cell and the manner in which they are glued is compatible with the choice of fluxes and holonomies. We first remark that the fluxes provide each edge with an angular momentum. By studying the piecewise-flat geometries which minimize edge lengths, we show that these angular momenta can be literally interpreted as the spin of the edges: the geometries of all edges are necessarily helices. We also show that the compatibility of the gluing maps with the holonomy data results in the same conclusion. This shows that a spinning geometry represents a way to glue together the three-cells of a twisted geometry to form a continuous geometry which represents a point in the loop gravity phase space. (paper)
The structure of spectral problems and geometry: hyperbolic surfaces in E sup 3
Cieslinski, J L
2003-01-01
Working in the framework of Sym's soliton surfaces approach we point out that some simple assumptions about the structure of linear (spectral) problems of the theory of solitons lead uniquely to the geometry of some special immersions. In this paper we consider general su(2) spectral problems. Under some very weak assumptions they turn out to be associated with hyperbolic surfaces (surfaces of negative Gaussian curvature) immersed in three-dimensional Euclidean space, and especially with the so-called Bianchi surfaces.
Functionalized Surface Geometries Induce: “Bone: Formation by Autoinduction”
Directory of Open Access Journals (Sweden)
Ugo Ripamonti
2018-02-01
Full Text Available The induction of tissue formation, and the allied disciplines of tissue engineering and regenerative medicine, have flooded the twenty-first century tissue biology scenario and morphed into high expectations of a fulfilling regenerative dream of molecularly generated tissues and organs in assembling human tissue factories. The grand conceptualization of deploying soluble molecular signals, first defined by Turing as forms generating substances, or morphogens, stemmed from classic last century studies that hypothesized the presence of morphogens in several mineralized and non-mineralized mammalian matrices. The realization of morphogens within mammalian matrices devised dissociative extractions and chromatographic procedures to isolate, purify, and finally reconstitute the cloned morphogens, found to be members of the transforming growth factor-β (TGF-β supergene family, with insoluble signals or substrata to induce de novo tissue induction and morphogenesis. Can we however construct macroporous bioreactors per se capable of inducing bone formation even without the exogenous applications of the osteogenic soluble molecular signals of the TGF-β supergene family? This review describes original research on coral-derived calcium phosphate-based macroporous constructs showing that the formation of bone is independent of the exogenous application of the osteogenic soluble signals of the TGF-β supergene family. Such signals are the molecular bases of the induction of bone formation. The aim of this review is to primarily describe today's hottest topic of biomaterials' science, i.e., to construct and define osteogenetic biomaterials' surfaces that per se, in its own right, do initiate the induction of bone formation. Biomaterials are often used to reconstruct osseous defects particularly in the craniofacial skeleton. Edentulism did spring titanium implants as tooth replacement strategies. No were else that titanium surfaces require functionalized
Geometry Laboratory (GEOLAB) surface modeling and grid generation technology and services
Kerr, Patricia A.; Smith, Robert E.; Posenau, Mary-Anne K.
1995-01-01
The facilities and services of the GEOmetry LABoratory (GEOLAB) at the NASA Langley Research Center are described. Included in this description are the laboratory functions, the surface modeling and grid generation technologies used in the laboratory, and examples of the tasks performed in the laboratory.
Surface complexation of selenite on goethite: MO/DFT geometry and charge distribution
Hiemstra, T.; Rietra, R.P.J.J.; Riemsdijk, van W.H.
2007-01-01
The adsorption of selenite on goethite (alpha-FeOOH) has been analyzed with the charge distribution (CD) and the multi-site surface complexation (MUSIC) model being combined with an extended Stem (ES) layer model option. The geometry of a set of different types of hydrated iron-selenite complexes
Parkes, Stephen
2016-10-25
Crop height measured from UAVs fitted with commercially available RGB cameras provide an affordable alternative to retrieve field scale high resolution estimates. The study presents an assessment of between flight reproducibility of Crop Surface Maps (CSM) extracted from Digital Surface Maps (DSM) generated by Structure from Motion (SfM) algorithms. Flights were conducted over a centre pivot irrigation system covered with an alfalfa crop. An important step in calculating the absolute crop height from the UAV derived DSM is determining the height of the underlying terrain. Here we use automatic thresholding techniques applied to RGB vegetation index maps to classify vegetated and soil pixels. From interpolation of classified soil pixels, a terrain map is calculated and subtracted from the DSM. The influence of three different thresholding techniques on CSMs are investigated. Median Alfalfa crop heights determined with the different thresholding methods varied from 18cm for K means thresholding to 13cm for Otsu thresholding methods. Otsu thresholding also gave the smallest range of crop heights and K means thresholding the largest. Reproducibility of median crop heights between flight surveys was 4-6cm for all thresholding techniques. For the flight conducted later in the afternoon shadowing caused soil pixels to be classified as vegetation in key locations around the domain, leading to lower crop height estimates. The range of crop heights was similar for both flights using K means thresholding (35-36cm), local minimum thresholding depended on whether raw or normalised RGB intensities were used to calculate vegetation indices (30-35cm), while Otsu thresholding had a smaller range of heights and varied most between flights (26-30cm). This study showed that crop heights from multiple survey flights are comparable, however, they were dependent on the thresholding method applied to classify soil pixels and the time of day the flight was conducted.
Parkes, Stephen; McCabe, Matthew; Al-Mashhawari, Samir K.; Rosas, Jorge
2016-01-01
Crop height measured from UAVs fitted with commercially available RGB cameras provide an affordable alternative to retrieve field scale high resolution estimates. The study presents an assessment of between flight reproducibility of Crop Surface Maps (CSM) extracted from Digital Surface Maps (DSM) generated by Structure from Motion (SfM) algorithms. Flights were conducted over a centre pivot irrigation system covered with an alfalfa crop. An important step in calculating the absolute crop height from the UAV derived DSM is determining the height of the underlying terrain. Here we use automatic thresholding techniques applied to RGB vegetation index maps to classify vegetated and soil pixels. From interpolation of classified soil pixels, a terrain map is calculated and subtracted from the DSM. The influence of three different thresholding techniques on CSMs are investigated. Median Alfalfa crop heights determined with the different thresholding methods varied from 18cm for K means thresholding to 13cm for Otsu thresholding methods. Otsu thresholding also gave the smallest range of crop heights and K means thresholding the largest. Reproducibility of median crop heights between flight surveys was 4-6cm for all thresholding techniques. For the flight conducted later in the afternoon shadowing caused soil pixels to be classified as vegetation in key locations around the domain, leading to lower crop height estimates. The range of crop heights was similar for both flights using K means thresholding (35-36cm), local minimum thresholding depended on whether raw or normalised RGB intensities were used to calculate vegetation indices (30-35cm), while Otsu thresholding had a smaller range of heights and varied most between flights (26-30cm). This study showed that crop heights from multiple survey flights are comparable, however, they were dependent on the thresholding method applied to classify soil pixels and the time of day the flight was conducted.
International Nuclear Information System (INIS)
Dokukin, M E; Sokolov, I; Guz, N V; Woodworth, C D
2015-01-01
Despite considerable advances in understanding the molecular nature of cancer, many biophysical aspects of malignant development are still unclear. Here we study physical alterations of the surface of human cervical epithelial cells during stepwise in vitro development of cancer (from normal to immortal (premalignant), to malignant). We use atomic force microscopy to demonstrate that development of cancer is associated with emergence of simple fractal geometry on the cell surface. Contrary to the previously expected correlation between cancer and fractals, we find that fractal geometry occurs only at a limited period of development when immortal cells become cancerous; further cancer progression demonstrates deviation from fractal. Because of the connection between fractal behaviour and chaos (or far from equilibrium behaviour), these results suggest that chaotic behaviour coincides with the cancer transformation of the immortalization stage of cancer development, whereas further cancer progression recovers determinism of processes responsible for cell surface formation. (paper)
International Nuclear Information System (INIS)
Chen, C.-K.; Su, C.-R.
2008-01-01
This study provides an inverse analysis to estimate the boundary thermal behavior of a furnace with two layer walls. The unknown temperature distribution of the outer surface and the geometry of the inner surface were estimated from the temperatures of a small number of measured points within the furnace wall. The present approach rearranged the matrix forms of the governing differential equations and then combined the reversed matrix method, the linear least squares error method and the concept of virtual area to determine the unknown boundary conditions of the furnace system. The dimensionless temperature data obtained from the direct problem were used to simulate the temperature measurements. The influence of temperature measurement errors upon the precision of the estimated results was also investigated. The advantage of this approach is that the unknown condition can be directly solved by only one calculation process without initially guessed temperatures, and the iteration process of the traditional method can be avoided in the analysis of the heat transfer. Therefore, the calculation in this work is more rapid and exact than the traditional method. The result showed that the estimation error of the geometry increased with increasing distance between measured points and inner surface and in preset error, and with decreasing number of measured points. However, the geometry of the furnace inner surface could be successfully estimated by only the temperatures of a small number of measured points within and near the outer surface under reasonable preset error
Finsler Geometry Modeling of an Orientation-Asymmetric Surface Model for Membranes
Proutorov, Evgenii; Koibuchi, Hiroshi
2017-12-01
In this paper, a triangulated surface model is studied in the context of Finsler geometry (FG) modeling. This FG model is an extended version of a recently reported model for two-component membranes, and it is asymmetric under surface inversion. We show that the definition of the model is independent of how the Finsler length of a bond is defined. This leads us to understand that the canonical (or Euclidean) surface model is obtained from the FG model such that it is uniquely determined as a trivial model from the viewpoint of well definedness.
Surface geometry of a rotating black hole in a magnetic field
International Nuclear Information System (INIS)
Kulkarni, R.; Dadhich, N.
1986-01-01
We study the intrinsic geometry of the surface of a rotating black hole in a uniform magnetic field, using a metric discovered by Ernst and Wild. Rotating black holes are analogous to material rotating bodies according to Smarr since black holes also tend to become more oblate on being spun up. Our study shows that the presence of a strong magnetic field ensures that a black hole actually becomes increasingly prolate on being spun up. Studying the intrinsic geometry of the black-hole surface also gives rise to an interesting embedding problem. Smarr shows that a Kerr black hole cannot be globally isometrically embedded in R 3 if its specific angular momentum a exceeds (√3 /2)mapprox.0.866. . .m. We show that in the presence of a magnetic field of strength B, satisfying 2- √3 2 m 2 3 for all values of the angular momentum
3D silicon breast surface mapping via structured light profilometry
Vairavan, R.; Ong, N. R.; Sauli, Z.; Kirtsaeng, S.; Sakuntasathien, S.; Shahimin, M. M.; Alcain, J. B.; Lai, S. L.; Paitong, P.; Retnasamy, V.
2017-09-01
Digital fringe projection technique is one of the promising optical methods for 3D surface imaging as it demonstrates non contact and non invasive characteristics. The potential of this technique matches the requirement for human body evaluation, as it is vital for disease diagnosis and for treatment option selection. Thus, the digital fringe projection has addressed this requirement with its wide clinical related application and studies. However, the application of this technique for 3D surface mapping of the breast is very minimal. Hence, in this work, the application of digital fringe projection for 3D breast surface mapping is reported. Phase shift fringe projection technique was utilized to perform the 3D breast surface mapping. Maiden results have confirmed the feasibility of using the digital fringe projection method for 3D surface mapping of the breast and it can be extended for breast cancer detection.
Molecular surface mesh generation by filtering electron density map.
Giard, Joachim; Macq, Benoît
2010-01-01
Bioinformatics applied to macromolecules are now widely spread and in continuous expansion. In this context, representing external molecular surface such as the Van der Waals Surface or the Solvent Excluded Surface can be useful for several applications. We propose a fast and parameterizable algorithm giving good visual quality meshes representing molecular surfaces. It is obtained by isosurfacing a filtered electron density map. The density map is the result of the maximum of Gaussian functions placed around atom centers. This map is filtered by an ideal low-pass filter applied on the Fourier Transform of the density map. Applying the marching cubes algorithm on the inverse transform provides a mesh representation of the molecular surface.
Molecular Surface Mesh Generation by Filtering Electron Density Map
Directory of Open Access Journals (Sweden)
Joachim Giard
2010-01-01
Full Text Available Bioinformatics applied to macromolecules are now widely spread and in continuous expansion. In this context, representing external molecular surface such as the Van der Waals Surface or the Solvent Excluded Surface can be useful for several applications. We propose a fast and parameterizable algorithm giving good visual quality meshes representing molecular surfaces. It is obtained by isosurfacing a filtered electron density map. The density map is the result of the maximum of Gaussian functions placed around atom centers. This map is filtered by an ideal low-pass filter applied on the Fourier Transform of the density map. Applying the marching cubes algorithm on the inverse transform provides a mesh representation of the molecular surface.
Perez-Alday, Erick A; Thomas, Jason A; Kabir, Muammar; Sedaghat, Golriz; Rogovoy, Nichole; van Dam, Eelco; van Dam, Peter; Woodward, William; Fuss, Cristina; Ferencik, Maros; Tereshchenko, Larisa G
We conducted a prospective clinical study (n=14; 29% female) to assess the accuracy of a three-dimensional (3D) photography-based method of torso geometry reconstruction and body surface electrodes localization. The position of 74 body surface electrocardiographic (ECG) electrodes (diameter 5mm) was defined by two methods: 3D photography, and CT (marker diameter 2mm) or MRI (marker size 10×20mm) imaging. Bland-Altman analysis showed good agreement in X (bias -2.5 [95% limits of agreement (LoA) -19.5 to 14.3] mm), Y (bias -0.1 [95% LoA -14.1 to 13.9] mm), and Z coordinates (bias -0.8 [95% LoA -15.6 to 14.2] mm), as defined by the CT/MRI imaging, and 3D photography. The average Hausdorff distance between the two torso geometry reconstructions was 11.17±3.05mm. Thus, accurate torso geometry reconstruction using 3D photography is feasible. Body surface ECG electrodes coordinates as defined by the CT/MRI imaging, and 3D photography, are in good agreement. Copyright © 2017 Elsevier Inc. All rights reserved.
Lundh, Torbjörn; Suh, Ga-Young; DiGiacomo, Phillip; Cheng, Christopher
2018-03-03
Vascular morphology characterization is useful for disease diagnosis, risk stratification, treatment planning, and prediction of treatment durability. To quantify the dynamic surface geometry of tubular-shaped anatomic structures, we propose a simple, rigorous Lagrangian cylindrical coordinate system to monitor well-defined surface points. Specifically, the proposed system enables quantification of surface curvature and cross-sectional eccentricity. Using idealized software phantom examples, we validate the method's ability to accurately quantify longitudinal and circumferential surface curvature, as well as eccentricity and orientation of eccentricity. We then apply the method to several medical imaging data sets of human vascular structures to exemplify the utility of this coordinate system for analyzing morphology and dynamic geometric changes in blood vessels throughout the body. Graphical abstract Pointwise longitudinal curvature of a thoracic aortic endograft surface for systole and diastole, with their absolute difference.
International Nuclear Information System (INIS)
Carvalho-Santos, V.L.; Apolonio, F.A.; Oliveira-Neto, N.M.
2013-01-01
We study the Heisenberg model on cylindrically symmetric curved surfaces. Two kinds of excitations are considered. The first is given by the isotropic regime, yielding the sine-Gordon equation and π solitons are predicted. The second one is given by the XY model, leading to a vortex turning around the surface. Helical states are also considered, however, topological arguments cannot be used to ensure its stability. The energy and the anisotropy parameter which stabilizes the vortex state are explicitly calculated for two surfaces: catenoid and hyperboloid. The results show that the anisotropy and the vortex energy depends on the underlying geometry. -- Highlights: •Applying the anisotropic Heisenberg model on curved surfaces. •Appearance of topological solitons on curved surfaces with cylindrical symmetry. •Calculus of the vortex energy, which depends on curvature. •Discussion on features of non-topological helical-like states. •Vortex stability ensured by the anisotropy parameter value
Air transport pilots' information priorities for surface moving maps
2003-10-13
The use of a surface map display for operations on or near the airport surface (taxi out, takeoff, final approach and landing, taxi in) is expected to enhance safety. There is a lack of research, however, detailing how the airport surface should be d...
Craidon, C. B.
1975-01-01
A computer program that uses a three-dimensional geometric technique for fitting a smooth surface to the component parts of an aircraft configuration is presented. The resulting surface equations are useful in performing various kinds of calculations in which a three-dimensional mathematical description is necessary. Programs options may be used to compute information for three-view and orthographic projections of the configuration as well as cross-section plots at any orientation through the configuration. The aircraft geometry input section of the program may be easily replaced with a surface point description in a different form so that the program could be of use for any three-dimensional surface equations.
Observation of sagittal X-ray diffraction by surface acoustic waves in Bragg geometry.
Vadilonga, Simone; Zizak, Ivo; Roshchupkin, Dmitry; Evgenii, Emelin; Petsiuk, Andrei; Leitenberger, Wolfram; Erko, Alexei
2017-04-01
X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La 3 Ga 5 SiO 14 ) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasonic superlattice. Experimental results are compared with the corresponding theoretical model that exploits the kinematical diffraction theory. This experiment shows that the propagation of the surface acoustic waves creates a dynamical diffraction grating on the crystal surface, and this can be used for space-time modulation of an X-ray beam.
Biofilm formation in geometries with different surface curvature and oxygen availability
International Nuclear Information System (INIS)
Chang, Ya-Wen; Fragkopoulos, Alexandros A; Kim, Harold D; Fernández-Nieves, Alberto; Marquez, Samantha M; Angelini, Thomas E
2015-01-01
Bacteria in the natural environment exist as interface-associated colonies known as biofilms . Complex mechanisms are often involved in biofilm formation and development. Despite the understanding of the molecular mechanisms involved in biofilm formation, it remains unclear how physical effects in standing cultures influence biofilm development. The topology of the solid interface has been suggested as one of the physical cues influencing bacteria-surface interactions and biofilm development. Using the model organism Bacillus subtilis, we study the transformation of swimming bacteria in liquid culture into robust biofilms in a range of confinement geometries (planar, spherical and toroidal) and interfaces (air/water, silicone/water, and silicone elastomer/water). We find that B. subtilis form submerged biofilms at both solid and liquid interfaces in addition to air-water pellicles. When confined, bacteria grow on curved surfaces of both positive and negative Gaussian curvature. However, the confinement geometry does affect the resulting biofilm roughness and relative coverage. We also find that the biofilm location is governed by oxygen availability as well as by gravitational effects; these compete with each other in some situations. Overall, our results demonstrate that confinement geometry is an effective way to control oxygen availability and subsequently biofilm growth. (paper)
Simultaneous beam geometry and intensity map optimization in intensity-modulated radiation therapy
International Nuclear Information System (INIS)
Lee, Eva K.; Fox, Tim; Crocker, Ian
2006-01-01
angles returned appear to be nonintuitive, and depend on PTV size and geometry and the s patial relationship between the tumor and critical structures. Conclusions: The MIP model described allows simultaneous optimization over the space of beamlet fluence weights and beam and couch angles. Based on experiments with tumor data, this approach can return good plans that are clinically acceptable and practical. This work distinguishes itself from recent IMRT research in several ways. First, in previous methods beam angles are selected before intensity map optimization. Herein, we employ 0/1 variables to model the set of candidate beams, and thereby allow the optimization process itself to select optimal beams. Second, instead of incorporating dose-volume criteria within the objective function as in previous work, herein, a combination of discrete and continuous variables associated with each voxel provides a mechanism to strictly enforce dose-volume criteria within the constraints. Third, using the construct of critical-normal-tissue-ring within the objective function can enhance the achievement of conformal plans. Based on the three tumor sites considered, it appears that volume and spatial geometry with respect to the PTV are important factors to consider when selecting objectives to optimize, and in estimating how well suited a particular model is for achieving a specified goal
International Nuclear Information System (INIS)
Christodoulakis, T; Doulis, G; Terzis, Petros A; Melas, E; Grammenos, Th; Papadopoulos, G O; Spanou, A
2010-01-01
The canonical decomposition of all 3+1 geometries admitting two-dimensional space-like surfaces is exhibited as a generalization of a previous work. A proposal, consisting of a specific renormalization Assumption and an accompanying Requirement, which has been put forward in the 2+1 case is now generalized to 3+1 dimensions. This enables the canonical quantization of these geometries through a generalization of Kuchar's quantization scheme in the case of infinite degrees of freedom. The resulting Wheeler-DeWitt equation is based on a renormalized manifold parameterized by three smooth scalar functionals. The entire space of solutions to this equation is analytically given, a fact that is entirely new to the present case. This is made possible through the exploitation of the residual freedom in the choice of the third functional, which is left by the imposition of the Requirement, and is proven to correspond to a general coordinate transformation in the renormalized manifold.
Surface geometry of protoplanetary disks inferred from near-infrared imaging polarimetry
International Nuclear Information System (INIS)
Takami, Michihiro; Hasegawa, Yasuhiro; Gu, Pin-Gao; Karr, Jennifer L.; Chapillon, Edwige; Tang, Ya-Wen; Muto, Takayuki; Dong, Ruobing; Hashimoto, Jun; Kusakabe, Nobuyuki; Akiyama, Eiji; Kwon, Jungmi; Itoh, Youchi; Carson, Joseph; Follette, Katherine B.; Mayama, Satoshi; Sitko, Michael; Janson, Markus; Grady, Carol A.; Kudo, Tomoyuki
2014-01-01
We present a new method of analysis for determining the surface geometry of five protoplanetary disks observed with near-infrared imaging polarimetry using Subaru-HiCIAO. Using as inputs the observed distribution of polarized intensity (PI), disk inclination, assumed properties for dust scattering, and other reasonable approximations, we calculate a differential equation to derive the surface geometry. This equation is numerically integrated along the distance from the star at a given position angle. We show that, using these approximations, the local maxima in the PI distribution of spiral arms (SAO 206462, MWC 758) and rings (2MASS J16042165-2130284, PDS 70) are associated with local concave-up structures on the disk surface. We also show that the observed presence of an inner gap in scattered light still allows the possibility of a disk surface that is parallel to the light path from the star, or a disk that is shadowed by structures in the inner radii. Our analysis for rings does not show the presence of a vertical inner wall as often assumed in studies of disks with an inner gap. Finally, we summarize the implications of spiral and ring structures as potential signatures of ongoing planet formation.
Surface geometry of protoplanetary disks inferred from near-infrared imaging polarimetry
Energy Technology Data Exchange (ETDEWEB)
Takami, Michihiro; Hasegawa, Yasuhiro; Gu, Pin-Gao; Karr, Jennifer L.; Chapillon, Edwige; Tang, Ya-Wen [Institute of Astronomy and Astrophysics, Academia Sinica, PO Box 23-141, Taipei 10617, Taiwan, ROC (China); Muto, Takayuki [Division of Liberal Arts, Kogakuin University, 1-24-2, Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-8677 (Japan); Dong, Ruobing [Nuclear Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Hashimoto, Jun [H. L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St. Norman, OK 73019 (United States); Kusakabe, Nobuyuki; Akiyama, Eiji; Kwon, Jungmi [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Itoh, Youchi [Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2 Nishigaichi, Sayo, Sayo, Hyogo 679-5313 (Japan); Carson, Joseph [Department of Physics and Astronomy, College of Charleston, 58 Coming Street, Charleston, SC 29424 (United States); Follette, Katherine B. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Mayama, Satoshi [The Center for the Promotion of Integrated Sciences, The Graduate University for Advanced Studies (SOKENDAI), Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0193 (Japan); Sitko, Michael [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States); Janson, Markus [Astrophysics Research Center, Queen' s University Belfast, BT7 1NN (United Kingdom); Grady, Carol A. [Eureka Scientific, 2452 Delmer Suite 100, Oakland, CA 96402 (United States); Kudo, Tomoyuki, E-mail: hiro@asiaa.sinica.edu.tw [Subaru Telescope, 650 North Aohoku Place, Hilo, HI 96720 (United States); and others
2014-11-01
We present a new method of analysis for determining the surface geometry of five protoplanetary disks observed with near-infrared imaging polarimetry using Subaru-HiCIAO. Using as inputs the observed distribution of polarized intensity (PI), disk inclination, assumed properties for dust scattering, and other reasonable approximations, we calculate a differential equation to derive the surface geometry. This equation is numerically integrated along the distance from the star at a given position angle. We show that, using these approximations, the local maxima in the PI distribution of spiral arms (SAO 206462, MWC 758) and rings (2MASS J16042165-2130284, PDS 70) are associated with local concave-up structures on the disk surface. We also show that the observed presence of an inner gap in scattered light still allows the possibility of a disk surface that is parallel to the light path from the star, or a disk that is shadowed by structures in the inner radii. Our analysis for rings does not show the presence of a vertical inner wall as often assumed in studies of disks with an inner gap. Finally, we summarize the implications of spiral and ring structures as potential signatures of ongoing planet formation.
Pseudo-periodic maps and degeneration of Riemann surfaces
Matsumoto, Yukio
2011-01-01
The first part of the book studies pseudo-periodic maps of a closed surface of genus greater than or equal to two. This class of homeomorphisms was originally introduced by J. Nielsen in 1944 as an extension of periodic maps. In this book, the conjugacy classes of the (chiral) pseudo-periodic mapping classes are completely classified, and Nielsen’s incomplete classification is corrected. The second part applies the results of the first part to the topology of degeneration of Riemann surfaces. It is shown that the set of topological types of all the singular fibers appearing in one-parameter holomorphic families of Riemann surfaces is in a bijective correspondence with the set of conjugacy classes of the pseudo-periodic maps of negative twists. The correspondence is given by the topological monodromy.
Geometry of GLP on silver surface by surface-enhanced Raman spectroscopy
Bao, PeiDi; Bao, Lang; Huang, TianQuan; Liu, XinMing; Wu, GuoFeng
2000-05-01
Leptospirosis is one of the most harmful zoonosis, it is a serious public health issue in some area of Sichuan province. Surface-Enhance Raman Scattering (SERS) Spectroscopy is an effective approach for the study of biomolecular adsorption on metal surface and provides information about the adsorbed species. Two samples of Leptospiral Glycolipoprotein (GLP-1) and GLP-2 which have different toxic effects have been obtained and investigated.
Panter, J. R.; Kusumaatmaja, H.
2017-03-01
The fundamental impacts of surface geometry on the stability of wetting states, and the transitions between them are elucidated for square posts and reentrant structures in three dimensions. We identify three principal outcomes of particular importance for future surface design of liquid-repellent surfaces. Firstly, we demonstrate and quantify how capillary condensation and vapour cavitation affect wetting state stabilities. At high contact angles, cavitation is enhanced about wide, closely-spaced square posts, leading to the existence of suspended states without an associated collapsed state. At low contact angles, narrow reentrant pillars suppress condensation and enable the suspension of even highly wetting liquids. Secondly, two distinct collapse mechanisms are observed for 3D reentrant geometries, base contact and pillar contact, which are operative at different pillar heights. As well as morphological differences in the interface of the penetrating liquid, each mechanism is affected differently by changes in the contact angle with the solid. Finally, for highly-wetting liquids, condensates are shown to critically modify the transition pathways in both the base contact and pillar contact modes.
Multiple patterns of diblock copolymer confined in irregular geometries with soft surface
Li, Ying; Sun, Min-Na; Zhang, Jin-Jun; Pan, Jun-Xing; Guo, Yu-Qi; Wang, Bao-Feng; Wu, Hai-Shun
2015-12-01
The different confinement shapes can induce the formation of various interesting and novel morphologies, which might inspire potential applications of materials. In this paper, we study the directed self-assembly of diblock copolymer confined in irregular geometries with a soft surface by using self-consistent field theory. Two types of confinement geometries are considered, namely, one is the concave pore with one groove and the other is the concave pore with two grooves. We obtain more novel and different structures which could not be produced in other two-dimensional (2D) confinements. Comparing these new structures with those obtained in regular square confinement, we find that the range of ordered lamellae is enlarged and the range of disordered structure is narrowed down under the concave pore confinement. We also compare the different structures obtained under the two types of confinement geometries, the results show that the effect of confinement would increase, which might induce the diblock copolymer to form novel structures. We construct the phase diagram as a function of the fraction of B block and the ratio of h/L of the groove. The simulation reveals that the wetting effect of brushes and the shape of confinement geometries play important roles in determining the morphologies of the system. Our results improve the applications in the directed self-assembly of diblock copolymer for fabricating the irregular structures. Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20121404110004), the Research Foundation for Excellent Talents of Shanxi Provincial Department of Human Resources and Social Security, China, and the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province, China.
The abstract geometry modeling language (AgML): experience and road map toward eRHIC
International Nuclear Information System (INIS)
Webb, Jason; Lauret, Jerome; Perevoztchikov, Victor
2014-01-01
The STAR experiment has adopted an Abstract Geometry Modeling Language (AgML) as the primary description of our geometry model. AgML establishes a level of abstraction, decoupling the definition of the detector from the software libraries used to create the concrete geometry model. Thus, AgML allows us to support both our legacy GEANT 3 simulation application and our ROOT/TGeo based reconstruction software from a single source, which is demonstrably self- consistent. While AgML was developed primarily as a tool to migrate away from our legacy FORTRAN-era geometry codes, it also provides a rich syntax geared towards the rapid development of detector models. AgML has been successfully employed by users to quickly develop and integrate the descriptions of several new detectors in the RHIC/STAR experiment including the Forward GEM Tracker (FGT) and Heavy Flavor Tracker (HFT) upgrades installed in STAR for the 2012 and 2013 runs. AgML has furthermore been heavily utilized to study future upgrades to the STAR detector as it prepares for the eRHIC era. With its track record of practical use in a live experiment in mind, we present the status, lessons learned and future of the AgML language as well as our experience in bringing the code into our production and development environments. We will discuss the path toward eRHIC and pushing the current model to accommodate for detector miss-alignment and high precision physics.
Ray-map migration of transmitted surface waves
Li, Jing
2016-08-25
Near-surface normal faults can sometimes separate two distinct zones of velocity heterogeneity, where the medium on one side of the fault has a faster velocity than on the other side. Therefore, the slope of surface-wave arrivals in a common-shot gather should abruptly change near the surface projection of the fault. We present ray-map imaging method that migrates transmitted surface waves to the fault plane, and therefore it roughly estimates the orientation, depth, and location of the near-surface fault. The main benefits of this method are that it is computationally inexpensive and robust in the presence of noise.
A surface evolution scheme to identify nanoscale intrinsic geometry from AFM experimental data
International Nuclear Information System (INIS)
Jang, Hong-Lae; Kim, Hyun-Seok; Park, Youmie; Cho, Seonho
2013-01-01
The geometrical properties of metallic nanoparticles such as the size and morphology have significant impacts on the structure and stability of the adsorbed biological entities as well as the nanoscale structural performances. To identify the nanoscale intrinsic geometry from the height images by atomic force microscopy (AFM), we developed a curvature-dependent evolution scheme that can eliminate the noise and smoothen the surfaces. The principal curvatures are computed directly from the first and second derivatives of the discrete AFM height data. The principal curvatures and directions correspond to the eigenvalues and eigenvectors of shape operator matrix, respectively. The evolution equation using the principal curvature flows smoothens the images in the corresponding principal directions. For an idealized model, κ 2 flow successfully identifies the major valley lines to represent the boundary of nanoparticles without referring to the phase information, whereas the mean curvature flow eliminates all the minor ones leaving only the major feature of the boundary. To demonstrate the capability of noise removal, smoothing surfaces, the identification of ridge and valley lines, and the extraction of intrinsic geometry, the developed numerical scheme is applied to real AFM data that include the silver nanoparticles of 24 nm diameter and the gold nanoparticles of 33–56 nm diameters
Kelly, Debbie M; Bischof, Walter F
2008-10-01
We investigated how human adults orient in enclosed virtual environments, when discrete landmark information is not available and participants have to rely on geometric and featural information on the environmental surfaces. In contrast to earlier studies, where, for women, the featural information from discrete landmarks overshadowed the encoding of the geometric information, Experiment 1 showed that when featural information is conjoined with the environmental surfaces, men and women encoded both types of information. Experiment 2 showed that, although both types of information are encoded, performance in locating a goal position is better if it is close to a geometrically or featurally distinct location. Furthermore, although features are relied upon more strongly than geometry, initial experience with an environment influences the relative weighting of featural and geometric cues. Taken together, these results show that human adults use a flexible strategy for encoding spatial information.
Influence of Surface Geometry of Grating Substrate on Director in Nematic Liquid Crystal Cell
International Nuclear Information System (INIS)
Ye Wenjiang; Xing Hongyu; Yang Guochen; Zhang Zhidong; Sun Yubao; Chen Guoying; Xuan Li
2011-01-01
The director in nematic liquid crystal cell with a weak anchoring grating substrate and a strong anchoring planar substrate is relative to the coordinates x and z. The influence of the surface geometry of the grating substrate in the cell on the director profile is numerically simulated using the two-dimensional finite-difference iterative method under the condition of one elastic constant approximation and zero driven voltage. The deepness of groove and the cell gap affect the distribution of director. For the relatively shallow groove and the relatively thick cell gap, the director is only dependent on the coordinate z. For the relatively deep groove and the relatively thin cell gap, the director must be dependent on the two coordinates x and z because of the increased elastic strain energy induced by the grating surface. (condensed matter: structural, mechanical, and thermal properties)
Elementary excitations of biomembranes: Differential geometry of undulations in elastic surfaces
Energy Technology Data Exchange (ETDEWEB)
Hemmen, J. Leo van [Physik Department, Technical University of Munich, 85747 Garching (Germany)]. E-mail: lvh@tum.de; Leibold, Christian [Physik Department, Technical University of Munich, 85747 Garching (Germany)
2007-06-15
Biomembrane undulations are elementary excitations in the elastic surfaces of cells and vesicles. As such they can provide surprising insights into the mechanical processes that shape and stabilize biomembranes. We explain how naturally these undulations can be described by classical differential geometry. In particular, we apply the analytical formalism of differential-geometric calculus to the surfaces generated by a cell membrane and underlying cytoskeleton. After a short derivation of the energy due to a membrane's elasticity, we show how undulations arise as elementary excitations originating from the second derivative of an energy functional. Furthermore, we expound the efficiency of classical differential-geometric formalism to understand the effect of differential operators that characterize processes involved in membrane physics. As an introduction to concepts the paper is self-contained and rarely exceeds calculus level.
Elementary excitations of biomembranes: Differential geometry of undulations in elastic surfaces
International Nuclear Information System (INIS)
Hemmen, J. Leo van; Leibold, Christian
2007-01-01
Biomembrane undulations are elementary excitations in the elastic surfaces of cells and vesicles. As such they can provide surprising insights into the mechanical processes that shape and stabilize biomembranes. We explain how naturally these undulations can be described by classical differential geometry. In particular, we apply the analytical formalism of differential-geometric calculus to the surfaces generated by a cell membrane and underlying cytoskeleton. After a short derivation of the energy due to a membrane's elasticity, we show how undulations arise as elementary excitations originating from the second derivative of an energy functional. Furthermore, we expound the efficiency of classical differential-geometric formalism to understand the effect of differential operators that characterize processes involved in membrane physics. As an introduction to concepts the paper is self-contained and rarely exceeds calculus level
Surface mineral maps of Afghanistan derived from HyMap imaging spectrometer data, version 2
Kokaly, Raymond F.; King, Trude V.V.; Hoefen, Todd M.
2013-01-01
This report presents a new version of surface mineral maps derived from HyMap imaging spectrometer data collected over Afghanistan in the fall of 2007. This report also describes the processing steps applied to the imaging spectrometer data. The 218 individual flight lines composing the Afghanistan dataset, covering more than 438,000 square kilometers, were georeferenced to a mosaic of orthorectified Landsat images. The HyMap data were converted from radiance to reflectance using a radiative transfer program in combination with ground-calibration sites and a network of cross-cutting calibration flight lines. The U.S. Geological Survey Material Identification and Characterization Algorithm (MICA) was used to generate two thematic maps of surface minerals: a map of iron-bearing minerals and other materials, which have their primary absorption features at the shorter wavelengths of the reflected solar wavelength range, and a map of carbonates, phyllosilicates, sulfates, altered minerals, and other materials, which have their primary absorption features at the longer wavelengths of the reflected solar wavelength range. In contrast to the original version, version 2 of these maps is provided at full resolution of 23-meter pixel size. The thematic maps, MICA summary images, and the material fit and depth images are distributed in digital files linked to this report, in a format readable by remote sensing software and Geographic Information Systems (GIS). The digital files can be downloaded from http://pubs.usgs.gov/ds/787/downloads/.
SPICE: A Geometry Information System Supporting Planetary Mapping, Remote Sensing and Data Mining
Acton, C.; Bachman, N.; Semenov, B.; Wright, E.
2013-01-01
SPICE is an information system providing space scientists ready access to a wide assortment of space geometry useful in planning science observations and analyzing the instrument data returned therefrom. The system includes software used to compute many derived parameters such as altitude, LAT/LON and lighting angles, and software able to find when user-specified geometric conditions are obtained. While not a formal standard, it has achieved widespread use in the worldwide planetary science community
Ronsky, J L; Boyd, S K; Lichti, D D; Chapman, M A; Salkauskas, K
1999-04-01
Three-dimensional joint models are important tools for investigating mechanisms related to normal and pathological joints. Often these models necessitate accurate three-dimensional joint surface geometric data so that reliable model results can be obtained; however, in models based on small joints, this is often problematic due to limitations of the present techniques. These limitations include insufficient measurement precision the requirement of contact for the measurement process, and lack of entire joint description. This study presents a new non-contact method for precise determination of entire joint surfaces using multistation digital photogrammetry (MDPG) and is demonstrated by determining the cartilage and subchondral bone surfaces of the cat patellofemoral (PF) joint. The digital camera-lens setup was precisely calibrated using 16 photographs arranged to achieve highly convergent geometry to estimate interior and distortion parameters of the camera-lens setup. Subsequently, six photographs of each joint surface were then acquired for surface measurement. The digital images were directly imported to a computer and newly introduced semi-automatic computer algorithms were used to precisely determine the image coordinates. Finally, a rigorous mathematical procedure named the bundle adjustment was used to determine the three-dimensional coordinates of the joint surfaces and to estimate the precision of the coordinates. These estimations were validated by comparing the MDPG measurements of a cylinder and plane to an analytical model. The joint surfaces were successfully measured using the MDPG method with mean precision estimates in the least favorable coordinate direction being 10.3 microns for subchondral bone and 17.9 microns for cartilage. The difference in measurement precision for bone and cartilage primarily reflects differences in the translucent properties of the surfaces.
Estrada, T; Zhang, B; Cicotti, P; Armen, R S; Taufer, M
2012-07-01
We present a scalable and accurate method for classifying protein-ligand binding geometries in molecular docking. Our method is a three-step process: the first step encodes the geometry of a three-dimensional (3D) ligand conformation into a single 3D point in the space; the second step builds an octree by assigning an octant identifier to every single point in the space under consideration; and the third step performs an octree-based clustering on the reduced conformation space and identifies the most dense octant. We adapt our method for MapReduce and implement it in Hadoop. The load-balancing, fault-tolerance, and scalability in MapReduce allow screening of very large conformation spaces not approachable with traditional clustering methods. We analyze results for docking trials for 23 protein-ligand complexes for HIV protease, 21 protein-ligand complexes for Trypsin, and 12 protein-ligand complexes for P38alpha kinase. We also analyze cross docking trials for 24 ligands, each docking into 24 protein conformations of the HIV protease, and receptor ensemble docking trials for 24 ligands, each docking in a pool of HIV protease receptors. Our method demonstrates significant improvement over energy-only scoring for the accurate identification of native ligand geometries in all these docking assessments. The advantages of our clustering approach make it attractive for complex applications in real-world drug design efforts. We demonstrate that our method is particularly useful for clustering docking results using a minimal ensemble of representative protein conformational states (receptor ensemble docking), which is now a common strategy to address protein flexibility in molecular docking. Copyright © 2012 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Mikdam Jamal
2017-12-01
Full Text Available Metal additive manufacturing (AM is increasingly used to create complex 3D components at near net shape. However, the surface finish (SF of the metal AM part is uneven, with surface roughness being variable over the facets of the design. Standard post-processing methods such as grinding and linishing often meet with major challenges in finishing parts of complex shape. This paper reports on research that demonstrated that mass finishing (MF processes are able to deliver high-quality surface finishes (Ra and Sa on AM-generated parts of a relatively complex geometry (both internal features and external facets under select conditions. Four processes were studied in this work: stream finishing, high-energy (HE centrifuge, drag finishing and disc finishing. Optimisation of the drag finishing process was then studied using a structured design of experiments (DOE. The effects of a range of finishing parameters were evaluated and optimal parameters and conditions were determined. The study established that the proposed method can be successfully applied in drag finishing to optimise the surface roughness in an industrial application and that it is an economical way of obtaining the maximum amount of information in a short period of time with a small number of tests. The study has also provided an important step in helping understand the requirements of MF to deliver AM-generated parts to a target quality finish and cycle time.
Impact of electrode geometry on an atmospheric pressure surface barrier discharge
Hasan, M. I.; Morabit, Y.; Dickenson, A.; Walsh, J. L.
2017-06-01
Several of the key characteristics of an atmospheric pressure surface barrier discharge (SBD) are heavily dependent on the geometrical configuration of the plasma generating electrodes. This paper reveals that increasing the surface area of an SBD device by reducing the gaps within the electrodes can have major and unforeseen consequence on the discharge properties. It is experimentally demonstrated that a critical limit exists when reducing the diameter of a circular electrode gap below 5 mm, beyond which the required breakdown voltage increases exponentially and the power deposited in the discharge is impeded. Using a numerical model, it is shown that a reduced electrode gap diameter yields a decrease in the voltage difference between the electrode and dielectric surface, thus lowering the maximum electric field. This study indicates a link between the electrode geometry and the nature of the reactive chemistry produced in the plasma, findings which have wide-reaching implications for many applications where multiple closely packed surface barrier discharges are employed to achieve uniform and large area plasma processing.
Kim, Youngdeuk; Kim, Wooseung
2011-01-01
The quantitative correlations between workpiece volume and melt pool geometry, as well as the flow and thermal features of the melt pool are established. Thermocapillary convections in melt pool with a deformable free surface are investigated
Multi-Beam Surface Lidar for Lunar and Planetary Mapping
Bufton, Jack L.; Garvin, James B.
1998-01-01
Surface lidar techniques are now being demonstrated in low Earth orbit with a single beam of pulsed laser radiation at 1064 nm that profiles the vertical structure of Earth surface landforms along the nadir track of a spacecraft. In addition, a profiling laser altimeter, called MOLA, is operating in elliptical Martian orbit and returning surface topography data. These instruments form the basis for suggesting an improved lidar instrument that employs multiple beams for extension of sensor capabilities toward the goal of true, 3-dimensional mapping of the Moon or other similar planetary surfaces. In general the lidar waveform acquired with digitization of a laser echo can be used for laser distance measurement (i.e. range-to-the-surface) by time-of-flight measurement and for surface slope and shape measurements by examining the detailed lidar waveform. This is particularly effective when the intended target is the lunar surface or another planetary body free of any atmosphere. The width of the distorted return pulse is a first order measure of the surface incidence angle, a combination of surface slope and laser beam pointing. Assuming an independent and absolute (with respect to inertial space) measurement of laser beam pointing on the spacecraft, it is possible to derive a surface slope with-respect-to the mean planetary surface or its equipotential gravity surface. Higher-order laser pulse distortions can be interpreted in terms of the vertical relief of the surface or reflectivity variations within the area of the laser beam footprint on the surface.
Geometry and surface damage in micro electrical discharge machining of micro-holes
Ekmekci, Bülent; Sayar, Atakan; Tecelli Öpöz, Tahsin; Erden, Abdulkadir
2009-10-01
Geometry and subsurface damage of blind micro-holes produced by micro electrical discharge machining (micro-EDM) is investigated experimentally to explore the relational dependence with respect to pulse energy. For this purpose, micro-holes are machined with various pulse energies on plastic mold steel samples using a tungsten carbide tool electrode and a hydrocarbon-based dielectric liquid. Variations in the micro-hole geometry, micro-hole depth and over-cut in micro-hole diameter are measured. Then, unconventional etching agents are applied on the cross sections to examine micro structural alterations within the substrate. It is observed that the heat-damaged segment is composed of three distinctive layers, which have relatively high thicknesses and vary noticeably with respect to the drilling depth. Crack formation is identified on some sections of the micro-holes even by utilizing low pulse energies during machining. It is concluded that the cracking mechanism is different from cracks encountered on the surfaces when machining is performed by using the conventional EDM process. Moreover, an electrically conductive bridge between work material and debris particles is possible at the end tip during machining which leads to electric discharges between the piled segments of debris particles and the tool electrode during discharging.
Geometry and surface damage in micro electrical discharge machining of micro-holes
International Nuclear Information System (INIS)
Ekmekci, Bülent; Sayar, Atakan; Öpöz, Tahsin Tecelli; Erden, Abdulkadir
2009-01-01
Geometry and subsurface damage of blind micro-holes produced by micro electrical discharge machining (micro-EDM) is investigated experimentally to explore the relational dependence with respect to pulse energy. For this purpose, micro-holes are machined with various pulse energies on plastic mold steel samples using a tungsten carbide tool electrode and a hydrocarbon-based dielectric liquid. Variations in the micro-hole geometry, micro-hole depth and over-cut in micro-hole diameter are measured. Then, unconventional etching agents are applied on the cross sections to examine micro structural alterations within the substrate. It is observed that the heat-damaged segment is composed of three distinctive layers, which have relatively high thicknesses and vary noticeably with respect to the drilling depth. Crack formation is identified on some sections of the micro-holes even by utilizing low pulse energies during machining. It is concluded that the cracking mechanism is different from cracks encountered on the surfaces when machining is performed by using the conventional EDM process. Moreover, an electrically conductive bridge between work material and debris particles is possible at the end tip during machining which leads to electric discharges between the piled segments of debris particles and the tool electrode during discharging
Retrieval Algorithms for Road Surface Modelling Using Laser-Based Mobile Mapping
Directory of Open Access Journals (Sweden)
Antero Kukko
2008-09-01
Full Text Available Automated processing of the data provided by a laser-based mobile mapping system will be a necessity due to the huge amount of data produced. In the future, vehiclebased laser scanning, here called mobile mapping, should see considerable use for road environment modelling. Since the geometry of the scanning and point density is different from airborne laser scanning, new algorithms are needed for information extraction. In this paper, we propose automatic methods for classifying the road marking and kerbstone points and modelling the road surface as a triangulated irregular network. On the basis of experimental tests, the mean classification accuracies obtained using automatic method for lines, zebra crossings and kerbstones were 80.6%, 92.3% and 79.7%, respectively.
Sea surface temperature mapping using a thermal infrared scanner
Digital Repository Service at National Institute of Oceanography (India)
RameshKumar, M.R; Pandya, R; Mathur, K.M.; Charyulu, R; Rao, L.V.G.
1 metre water column below the sea surface. A thermal infrared scanner developed by the Space Applications Centre (ISRO), Ahmedabad was operated on board R.V. Gaveshani in April/May 1984 for mapping SST over the eastern Arabian Sea. SST values...
Groupoid extensions of mapping class representations for bordered surfaces
DEFF Research Database (Denmark)
Andersen, Jørgen Ellegaard; Bene, Alex; Penner, Robert
2009-01-01
by explicit formulae depending upon six essential cases, and the kernel and image of the groupoid representation are computed. Furthermore, this provides groupoid extensions of any representation of the mapping class group that factors through its action on the fundamental group of the surface including...
Use of roughness maps in visualisation of surfaces
DEFF Research Database (Denmark)
Seitavuopio, Paulus; Rantanen, Jukka; Yliruusi, Jouko
2005-01-01
monohydrate, theophylline anhydrate, sodium chloride and potassium chloride. The roughness determinations were made by a laser profilometer. The new matrix method gives detailed roughness maps, which are able to show local variations in surface roughness values and provide an illustrative picture...
International Nuclear Information System (INIS)
Booth, Ivan; Fairhurst, Stephen
2007-01-01
We study the geometry and dynamics of both isolated and dynamical trapping horizons by considering the allowed variations of their foliating two-surfaces. This provides a common framework that may be used to consider both their possible evolutions and their deformations as well as derive the well-known flux laws. Using this framework, we unify much of what is already known about these objects as well as derive some new results. In particular we characterize and study the ''almost isolated'' trapping horizons known as slowly evolving horizons. It is for these horizons that a dynamical first law holds and this is analogous and closely related to the Hawking-Hartle formula for event horizons
Korsten, Maarten J.; Houkes, Z.
1990-01-01
A method is given to estimate the geometry and motion of a moving body surface from image sequences. To this aim a parametric model of the surface is used, in order to reformulate the problem to one of parameter estimation. After linearization of the model standard linear estimation methods can be
Modelling and analysis of flux surface mapping experiments on W7-X
Lazerson, Samuel; Otte, Matthias; Bozhenkov, Sergey; Sunn Pedersen, Thomas; Bräuer, Torsten; Gates, David; Neilson, Hutch; W7-X Team
2015-11-01
The measurement and compensation of error fields in W7-X will be key to the device achieving high beta steady state operations. Flux surface mapping utilizes the vacuum magnetic flux surfaces, a feature unique to stellarators and heliotrons, to allow direct measurement of magnetic topology, and thereby allows a highly accurate determination of remnant magnetic field errors. As will be reported separately at this meeting, the first measurements confirming the existence of nested flux surfaces in W7-X have been made. In this presentation, a synthetic diagnostic for the flux surface mapping diagnostic is presented. It utilizes Poincaré traces to construct an image of the flux surface consistent with the measured camera geometry, fluorescent rod sweep plane, and emitter beam position. Forward modeling of the high-iota configuration will be presented demonstrating an ability to measure the intrinsic error field using the U.S. supplied trim coil system on W7-X, and a first experimental assessment of error fields in W7-X will be presented. This work has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy.
Habash, Jarjis; Boggon, Titus J; Raftery, James; Chayen, Naomi E; Zagalsky, Peter F; Helliwell, John R
2003-07-01
Models of apocrustacyanin C(1) were refined against X-ray data recorded on Bending Magnet 14 at the ESRF to resolutions of 1.85 and 2 A from a space-grown and an earth-grown crystal, respectively, both using vapour-diffusion crystal-growth geometry. The space crystals were grown in the APCF on the NASA Space Shuttle. The microgravity crystal growth showed a cyclic nature attributed to Marangoni convection, thus reducing the benefits of the microgravity environment, as reported previously [Chayen et al. (1996), Q. Rev. Biophys. 29, 227-278]. A subsequent mosaicity evaluation, also reported previously, showed only a partial improvement in the space-grown crystals over the earth-grown crystals [Snell et al. (1997), Acta Cryst. D53, 231-239], contrary to the case for lysozyme crystals grown in space with liquid-liquid diffusion, i.e. without any major motion during growth [Snell et al. (1995), Acta Cryst. D52, 1099-1102]. In this paper, apocrustacyanin C(1) electron-density maps from the two refined models are now compared. It is concluded that the electron-density maps of the protein and the bound waters are found to be better overall for the structures of apocrustacyanin C(1) studied from the space-grown crystal compared with those from the earth-grown crystal, even though both crystals were grown using vapour-diffusion crystal-growth geometry. The improved residues are on the surface of the protein, with two involved in or nearby crystal lattice-forming interactions, thus linking an improved crystal-growth mechanism to the molecular level. The structural comparison procedures developed should themselves be valuable for evaluating crystal-growth procedures in the future.
SU-E-J-128: 3D Surface Reconstruction of a Patient Using Epipolar Geometry
Energy Technology Data Exchange (ETDEWEB)
Kotoku, J; Nakabayashi, S; Kumagai, S; Ishibashi, T; Kobayashi, T [Teikyo University, Itabashi-ku, Tokyo (Japan); Haga, A; Saotome, N [University of Tokyo Hospital, Bunkyo-ku, Tokyo (Japan); Arai, N [Teikyo University Hospital, Itabashi-ku, Tokyo (Japan)
2014-06-01
Purpose: To obtain a 3D surface data of a patient in a non-invasive way can substantially reduce the effort for the registration of patient in radiation therapy. To achieve this goal, we introduced the multiple view stereo technique, which is known to be used in a 'photo tourism' on the internet. Methods: 70 Images were taken with a digital single-lens reflex camera from different angles and positions. The camera positions and angles were inferred later in the reconstruction step. A sparse 3D reconstruction model was locating by SIFT features, which is robust for rotation and shift variance, in each image. We then found a set of correspondences between pairs of images by computing the fundamental matrix using the eight-point algorithm with RANSAC. After the pair matching, we optimized the parameter including camera positions to minimize the reprojection error by use of bundle adjustment technique (non-linear optimization). As a final step, we performed dense reconstruction and associate a color with each point using the library of PMVS. Results: Surface data were reconstructed well by visual inspection. The human skin is reconstructed well, althogh the reconstruction was time-consuming for direct use in daily clinical practice. Conclusion: 3D reconstruction using multi view stereo geometry is a promising tool for reducing the effort of patient setup. This work was supported by JSPS KAKENHI(25861128)
SU-E-J-128: 3D Surface Reconstruction of a Patient Using Epipolar Geometry
International Nuclear Information System (INIS)
Kotoku, J; Nakabayashi, S; Kumagai, S; Ishibashi, T; Kobayashi, T; Haga, A; Saotome, N; Arai, N
2014-01-01
Purpose: To obtain a 3D surface data of a patient in a non-invasive way can substantially reduce the effort for the registration of patient in radiation therapy. To achieve this goal, we introduced the multiple view stereo technique, which is known to be used in a 'photo tourism' on the internet. Methods: 70 Images were taken with a digital single-lens reflex camera from different angles and positions. The camera positions and angles were inferred later in the reconstruction step. A sparse 3D reconstruction model was locating by SIFT features, which is robust for rotation and shift variance, in each image. We then found a set of correspondences between pairs of images by computing the fundamental matrix using the eight-point algorithm with RANSAC. After the pair matching, we optimized the parameter including camera positions to minimize the reprojection error by use of bundle adjustment technique (non-linear optimization). As a final step, we performed dense reconstruction and associate a color with each point using the library of PMVS. Results: Surface data were reconstructed well by visual inspection. The human skin is reconstructed well, althogh the reconstruction was time-consuming for direct use in daily clinical practice. Conclusion: 3D reconstruction using multi view stereo geometry is a promising tool for reducing the effort of patient setup. This work was supported by JSPS KAKENHI(25861128)
International Nuclear Information System (INIS)
Kurihara, Kazuyoshi; Otomo, Akira; Syouji, Atsushi; Takahara, Junichi; Suzuki, Koji; Yokoyama, Shiyoshi
2007-01-01
Analytic solutions to the superfocusing modes of surface plasmon polaritons in a conical geometry are theoretically studied using an ingenious method called the quasi-separation of variables. This method can be used to look for fundamental solutions to the wave equation for a field that must satisfy boundary conditions at all points on the continuous surface of tapered geometries. The set of differential equations exclusively separated from the wave equation can be consistently solved in combination with perturbation methods. This paper presents the zeroth-order perturbation solution of conical superfocusing modes with azimuthal symmetry and graphically represents them in electric field-line patterns
A cost-effective laser scanning method for mapping stream channel geometry and roughness
Lam, Norris; Nathanson, Marcus; Lundgren, Niclas; Rehnström, Robin; Lyon, Steve
2015-04-01
In this pilot project, we combine an Arduino Uno and SICK LMS111 outdoor laser ranging camera to acquire high resolution topographic area scans for a stream channel. The microprocessor and imaging system was installed in a custom gondola and suspended from a wire cable system. To demonstrate the systems capabilities for capturing stream channel topography, a small stream (< 2m wide) in the Krycklan Catchment Study was temporarily diverted and scanned. Area scans along the stream channel resulted in a point spacing of 4mm and a point cloud density of 5600 points/m2 for the 5m by 2m area. A grain size distribution of the streambed material was extracted from the point cloud using a moving window, local maxima search algorithm. The median, 84th and 90th percentiles (common metrics to describe channel roughness) of this distribution were found to be within the range of measured values while the largest modelled element was approximately 35% smaller than its measured counterpart. The laser scanning system captured grain sizes between 30mm and 255mm (coarse gravel/pebbles and boulders based on the Wentworth (1922) scale). This demonstrates that our system was capable of resolving both large-scale geometry (e.g. bed slope and stream channel width) and small-scale channel roughness elements (e.g. coarse gravel/pebbles and boulders) for the study area. We further show that the point cloud resolution is suitable for estimating ecohydraulic parameters such as Manning's n and hydraulic radius. Although more work is needed to fine-tune our system's design, these preliminary results are encouraging, specifically for those with a limited operational budget.
Dragt, A. J.; Roberts, P.; Stasevich, T. J.; Dragt, A. Bodoh-Creed A. J.; Roberts, P.; Stasevich, T. J.; Bodoh-Creed, A.; Walstrom, P. L.
2010-01-01
Three-dimensional field distributions from realistic beamline elements can be obtained only by measurement or by numerical solution of a boundary-value problem. In numerical charged-particle map generation, fields along a reference trajectory are differentiated multiple times. Any attempt to differentiate directly such field data multiple times is soon dominated by "noise" due to finite meshing and/or measurement errors. This problem can be overcome by the use of field data on a surface outsi...
Multi-channel Analysis of Passive Surface Waves (MAPS)
Xia, J.; Cheng, F. Mr; Xu, Z.; Wang, L.; Shen, C.; Liu, R.; Pan, Y.; Mi, B.; Hu, Y.
2017-12-01
Urbanization is an inevitable trend in modernization of human society. In the end of 2013 the Chinese Central Government launched a national urbanization plan—"Three 100 Million People", which aggressively and steadily pushes forward urbanization. Based on the plan, by 2020, approximately 100 million people from rural areas will permanently settle in towns, dwelling conditions of about 100 million people in towns and villages will be improved, and about 100 million people in the central and western China will permanently settle in towns. China's urbanization process will run at the highest speed in the urbanization history of China. Environmentally friendly, non-destructive and non-invasive geophysical assessment method has played an important role in the urbanization process in China. Because human noise and electromagnetic field due to industrial life, geophysical methods already used in urban environments (gravity, magnetics, electricity, seismic) face great challenges. But humanity activity provides an effective source of passive seismic methods. Claerbout pointed out that wavefileds that are received at one point with excitation at the other point can be reconstructed by calculating the cross-correlation of noise records at two surface points. Based on this idea (cross-correlation of two noise records) and the virtual source method, we proposed Multi-channel Analysis of Passive Surface Waves (MAPS). MAPS mainly uses traffic noise recorded with a linear receiver array. Because Multi-channel Analysis of Surface Waves can produces a shear (S) wave velocity model with high resolution in shallow part of the model, MPAS combines acquisition and processing of active source and passive source data in a same flow, which does not require to distinguish them. MAPS is also of ability of real-time quality control of noise recording that is important for near-surface applications in urban environment. The numerical and real-world examples demonstrated that MAPS can be
van Dessel, Pascal F.; van Hemel, Norbert M.; Groenewegen, Arne Sippens; de Bakker, Jacques M.; Linnebank, André C.; Defauw, Jo J.
2002-01-01
This article investigates the influence of body surface mapping on outcome of ventricular antiarrhythmic surgery. Preoperative mapping is advocated to optimize map-guided antiarrhythmic surgery of postinfarction ventricular tachycardia. We sequentially analyzed the results of catheter activation
Dynamic Corneal Surface Mapping with Electronic Speckle Pattern Interferometry
Iqbal, S.; Gualini, M. M. S.
2013-06-01
In view of the fast advancement in ophthalmic technology and corneal surgery, there is a strong need for the comprehensive mapping and characterization techniques for corneal surface. Optical methods with precision non-contact approaches have been found to be very useful for such bio measurements. Along with the normal mapping approaches, elasticity of corneal surface has an important role in its characterization and needs to be appropriately measured or estimated for broader diagnostics and better prospective surgical results, as it has important role in the post-op corneal surface reconstruction process. Use of normal corneal topographic devices is insufficient for any intricate analysis since these devices operate at relatively moderate resolution. In the given experiment, Pulsed Electronic Speckle Pattern Interferometry has been utilized along with an excitation mechanism to measure the dynamic response of the sample cornea. A Pulsed ESPI device has been chosen for the study because of its micron-level resolution and other advantages in real-time deformation analysis. A bovine cornea has been used as a sample in the subject experiment. The dynamic response has been taken on a chart recorder and it is observed that it does show a marked deformation at a specific excitation frequency, which may be taken as a characteristic elasticity parameter for the surface of that corneal sample. It was seen that outside resonance conditions the bovine cornea was not that much deformed. Through this study, the resonance frequency and the corresponding corneal deformations are mapped and plotted in real time. In these experiments, data was acquired and processed by FRAMES plus computer analysis system. With some analysis of the results, this technique can help us to refine a more detailed corneal surface mathematical model and some preliminary work was done on this. Such modelling enhancements may be useful for finer ablative surgery planning. After further experimentation
Directory of Open Access Journals (Sweden)
Matthew R. McCurry
2015-06-01
Full Text Available The reliability of finite element analysis (FEA in biomechanical investigations depends upon understanding the influence of model assumptions. In producing finite element models, surface mesh resolution is influenced by the resolution of input geometry, and influences the resolution of the ensuing solid mesh used for numerical analysis. Despite a large number of studies incorporating sensitivity studies of the effects of solid mesh resolution there has not yet been any investigation into the effect of surface mesh resolution upon results in a comparative context. Here we use a dataset of crocodile crania to examine the effects of surface resolution on FEA results in a comparative context. Seven high-resolution surface meshes were each down-sampled to varying degrees while keeping the resulting number of solid elements constant. These models were then subjected to bite and shake load cases using finite element analysis. The results show that incremental decreases in surface resolution can result in fluctuations in strain magnitudes, but that it is possible to obtain stable results using lower resolution surface in a comparative FEA study. As surface mesh resolution links input geometry with the resulting solid mesh, the implication of these results is that low resolution input geometry and solid meshes may provide valid results in a comparative context.
A shock surface geometry: The February 15--16, 1967, event
International Nuclear Information System (INIS)
Lepping, R.P.; Chao, J.K.
1976-01-01
The flare-associated interplanetary (IP) shock of February 15--16, 1967, observed by Explorer 33 and Pioneer 7 is analyzed to yield an estimation of the ecliptic plane geometry of the shock surface near 1 AU. These spacecraft were separated by 23degree in heliocentric longitude, and Pioneer 7 was at a distance of 1.12 AU from the sun. There was an 18.9-hour delay between the two observations. The estimated shock normal, obtained by using a least squares shock parameter fitting procedure for the Explorer 33 data, is found to be theta/subS//subE/=-53degree and phi/subS//subE/=198degree. The error cone angle for the shock normal of the Explorer 33 observation was approximately 7degree. This severely inclined shock normal is not typical of IP shocks. The shock normal at the Pioneer 7 position is found to be theta/subn/=-14degree and phi/subn/=161degree. However, the uncertainty is large (approx. =25degree for a 1sigma cone angle). Although a data gap occurred at the apparent time of passage of the disturbance at Pioneer 6,the recovered data did not suggest such a passage. A consistent picture of the shock propagation is given. The average shock speed from the sun to each spacecraft and the local speed at Explorer 33 and their relations to the position of the initiating solar flare are obtained and discussed. In the region of space between the earth and Pioneer 7 the shock surface radius of curvature in the ecliptic plane appears to have been 0.4 AU or less
International Nuclear Information System (INIS)
2005-01-01
Nature of physical problem solved: AUTOJOM is a computer program that will generate the coefficients of any quadratic equation used to define conic volumes and also the coefficients of the planes needed to define parallelepipeds, wedges, and pyramids. JOMREAD is a computer code to check any 3D geometry composed of and constructed with quadratic surfaces
International Nuclear Information System (INIS)
Streli, C.; Wobrauschek, P.; Kregsamer, P.; Pepponi, G.; Pianetta, P.; Pahlke, S.; Fabry, L.
2000-01-01
The determination of low Z elements, like Na and Al at ultra trace levels on Si wafer surfaces is demanded by semiconductor industry. SR-TXRF is a promising method to fulfill the task, if a special energy dispersive detector with an ultra thin window is used. Synchrotron radiation is the ideal suited excitation source for TXRF of low Z elements due to its intensive, natural collimated and linear polarized radiation with wide spectral range down to low energies even below 1 keV. TXRF offers some advantages for wafer surface analysis like nondestructive investigation and mapping capability. Experiments have been performed at SSRL beamline 3-4, a bending magnet beamline using white (<3 keV) and monochromatic radiation, as well as on beamline 3-3, using a crystal monochromator as well as a multilayer monochromator. A comparison of excitation detection geometries was performed, using a sidelooking detector with vertical positioned wafer as well as a downlooking detector with a horizontally arranged wafer. The advantages and disadvantages of the various geometries and excitation conditions are presented and the results compared. Detection limits are in the 100 fg range for Na, determined with droplet samples on Si wafer surfaces. (author)
Band mapping of surface states vs. adsorbate coverage
International Nuclear Information System (INIS)
Rotenberg, E.; Kevan, S.D.; Denlinger, J.D.; Chung, Jin-Wook
1997-01-01
The theory of electron bands, which arises from basic quantum mechanical principles, has been the cornerstone of solid state physics for over 60 years. Simply put, an energy band is an electron state in a solid whose energy varies with its momentum (similar to, but with a more complicated dependence than, how a free electron's energy is proportional to its momentum squared). Much attention over the last 15 years has been given to the study of band structure of surfaces and interfaces, especially as the applications of these two-dimensional systems have become increasingly important to industry and science. The ultraESCA endstation at beamline 7.01 at the Advanced Light Source was developed for very high-energy - (∼50 meV) and angular - ( 12 photons/sec) makes the detailed study of the evolution of bands possible. The authors are interested in learning how, when one forms a chemical bond between a metal and an overlaying atom or molecule, the resulting charge transfer to or from the adsorbate affects the surface bands. In some cases of interest, intermediate coverages lead to different band structure than at the extremes of clean and saturated surfaces. Surfaces of tungsten are particularly interesting, as their atomic geometry has been shown to be exquisitely sensitive to both the surface vibrational and electronic properties. In this study, the authors looked at the surface bands of tungsten ((110) surface), as a function both of coverage and mass of overlaying atoms. The adsorbed atoms were hydrogen and the alkali atoms lithium and cesium
Surface Mineralogy Mapping of Ceres from the Dawn Mission
McCord, T. B.; Zambon, F.
2017-12-01
Ceres' surface composition is of special interest because it is a window into the interior state and the past evolution of this dwarf planet. Disk-integrated telescopic spectral observations indicated that Ceres' surface is hydroxylated, similar to but not exactly the same as some of the carbonaceous chondrite classes of meteorites. Furthermore, Ceres' bulk density is low, indicating significant water content. The Dawn mission in orbit around Ceres, provided a new and larger set of observations on the mineralogy, molecular and elemental composition, and their distributions in association with surface features and geology. A set of articles was prepared, from which this presentation is derived, that is the first treatment of the entire surface composition of Ceres using the complete High Altitude Mapping Orbit (HAMO) Dawn Ceres data set and the calibrations from all the Dawn instruments. This report provides a current and comprehensive view of Ceres' surface composition and integrates them into general conclusions. Ceres' surface composition shows a fairly uniform distribution of NH4- and Mg-phyllosilicates, carbonates, mixed with a dark component. The widespread presence of phyllosilicates, and salts on Ceres' surface is indicative of the presence of aqueous alteration processes, which involved the whole dwarf planet. There is also likely some contamination by low velocity infall, as seen on Vesta, but it is more difficult to distinguish this infall from native Ceres material, unlike for the Vesta case.
Mapping the global land surface using 1 km AVHRR data
Lauer, D.T.; Eidenshink, J.C.
1998-01-01
The scientific requirements for mapping the global land surface using 1 km advanced very high resolution radiometer (AVHRR) data have been set forth by the U.S. Global Change Research Program; the International Geosphere Biosphere Programme (IGBP); The United Nations; the National Oceanic and Atmospheric Administration (NOAA); the Committee on Earth Observations Satellites; and the National Aeronautics and Space Administration (NASA) mission to planet Earth (MTPE) program. Mapping the global land surface using 1 km AVHRR data is an international effort to acquire, archive, process, and distribute 1 km AVHRR data to meet the needs of the international science community. A network of AVHRR receiving stations, along with data recorded by NOAA, has been acquiring daily global land coverage since April 1, 1992. A data set of over 70,000 AVHRR images is archived and distributed by the United States Geological Survey (USGS) EROS Data Center, and the European Space Agency. Under the guidance of the IGBP, processing standards have been developed for calibration, atmospheric correction, geometric registration, and the production of global 10-day maximum normalized difference vegetation index (NDVI) composites. The major uses of the composites are for the study of surface vegetation condition, mapping land cover, and deriving biophysical characteristics of terrestrial ecosystems. A time-series of 54 10-day global vegetation index composites for the period of April 1, 1992 through September 1993 has been produced. The production of a time-series of 33 10-day global vegetation index composites using NOAA-14 data for the period of February 1, 1995 through December 31, 1995 is underway. The data products are available from the USGS, in cooperation with NASA's MTPE program and other international organizations.
DEFF Research Database (Denmark)
Mosegaard, Jesper; Sørensen, Thomas Sangild
2005-01-01
Modern graphics processing units (GPUs) can be effectively used to solve physical systems. To use the GPUoptimally, the discretization of the physical system is often restricted to a regular grid. When grid values representspatial positions, a direct visualization can result in a jagged appearance....... In this paper we propose todecouple computation and visualization of such systems. We define mappings that enable the deformation of ahigh-resolution surface based on a physical simulation on a lower resolution uniform grid. More specifically weinvestigate new approaches for the visualization of a GPU based...
Explorations in topology map coloring, surfaces and knots
Gay, David
2013-01-01
Explorations in Topology, Second Edition, provides students a rich experience with low-dimensional topology (map coloring, surfaces, and knots), enhances their geometrical and topological intuition, empowers them with new approaches to solving problems, and provides them with experiences that will help them make sense of future, more formal topology courses. The book's innovative story-line style models the problem-solving process, presents the development of concepts in a natural way, and engages students in meaningful encounters with the material. The updated end-of-chapter investigation
Mapping gullies, dunes, lava fields, and landslides via surface roughness
Korzeniowska, Karolina; Pfeifer, Norbert; Landtwing, Stephan
2018-01-01
Gully erosion is a widespread and significant process involved in soil and land degradation. Mapping gullies helps to quantify past, and anticipate future, soil losses. Digital terrain models offer promising data for automatically detecting and mapping gullies especially in vegetated areas, although methods vary widely measures of local terrain roughness are the most varied and debated among these methods. Rarely do studies test the performance of roughness metrics for mapping gullies, limiting their applicability to small training areas. To this end, we systematically explored how local terrain roughness derived from high-resolution Light Detection And Ranging (LiDAR) data can aid in the unsupervised detection of gullies over a large area. We also tested expanding this method for other landforms diagnostic of similarly abrupt land-surface changes, including lava fields, dunes, and landslides, as well as investigating the influence of different roughness thresholds, resolutions of kernels, and input data resolution, and comparing our method with previously published roughness algorithms. Our results show that total curvature is a suitable metric for recognising analysed gullies and lava fields from LiDAR data, with comparable success to that of more sophisticated roughness metrics. Tested dunes or landslides remain difficult to distinguish from the surrounding landscape, partly because they are not easily defined in terms of their topographic signature.
Mapping surface properties of sinusoidal roughness standards by TPM
International Nuclear Information System (INIS)
Liu, X; Rubert, P
2005-01-01
We report our investigation on the surface properties of sinusoidal roughness standards made from pure electroformed nickel. Two specimens having a sinusoidal profile with nominal R a of 0.36 μm and a peak spacing of 25 μm are chosen for this investigation. One specimen is further treated with a hard protective coating of nickel-boron. The surface topography, friction, hardness and Young's modulus of the specimens were measured by a novel instrument, the multi-function Tribological Probe Microscope (TPM). The results show that hardness of these two specimens is 14.1 GPa for uncoated specimen and 25.7 GPa for the coated one, while the Young's modulus is 188 GPa and 225 GPa, respectively. The ramping force was set to 3mN for both the specimens and the effect of the tip penetration was investigated by comparing the topography measurements before and after hardness mapping. It has been found out that there is no significant change in the averaged profiles over the scanned area, which indicates the topography distortion seen in the multi-function mapping, is recoverable. Cross correlation between topography and its corresponding hardness/Young's modulus has been carried out and the result will be discussed in the paper
Potentiometric-surface map, 1993, Yucca Mountain and vicinity, Nevada
International Nuclear Information System (INIS)
Tucci, P.; Burkhardt, D.J.
1995-01-01
The revised potentiometric surface map here, using mainly 1993 average water levels, updates earlier maps of this area. Water levels are contoured with 20-m intervals, with additional 0.5-m contours in the small-gradient area SE of Yucca Mountain. Water levels range from 728 m above sea level SE of Yucca to 1,034 m above sea level north of Yucca. Potentiometric levels in the deeper parts of the volcanic rock aquifer range from 730 to 785 m above sea level. The potentiometric surface can be divided into 3 regions: A small gradient area E and SE of Yucca, a moderate-gradient area on the west side of Yucca, and a large-gradient area to the N-NE of Yucca. Water levels from wells at Yucca were examined for yearly trends (1986-93) using linear least-squares regression. Of the 22 wells, three had significant positive trends. The trend in well UE-25 WT-3 may be influenced by monitoring equipment problems. Tends in USW WT-7 and USW WTS-10 are similar; both are located near a fault west of Yucca; however another well near that fault exhibited no significant trend
Surface registration technique for close-range mapping applications
Habib, Ayman F.; Cheng, Rita W. T.
2006-08-01
Close-range mapping applications such as cultural heritage restoration, virtual reality modeling for the entertainment industry, and anatomical feature recognition for medical activities require 3D data that is usually acquired by high resolution close-range laser scanners. Since these datasets are typically captured from different viewpoints and/or at different times, accurate registration is a crucial procedure for 3D modeling of mapped objects. Several registration techniques are available that work directly with the raw laser points or with extracted features from the point cloud. Some examples include the commonly known Iterative Closest Point (ICP) algorithm and a recently proposed technique based on matching spin-images. This research focuses on developing a surface matching algorithm that is based on the Modified Iterated Hough Transform (MIHT) and ICP to register 3D data. The proposed algorithm works directly with the raw 3D laser points and does not assume point-to-point correspondence between two laser scans. The algorithm can simultaneously establish correspondence between two surfaces and estimates the transformation parameters relating them. Experiment with two partially overlapping laser scans of a small object is performed with the proposed algorithm and shows successful registration. A high quality of fit between the two scans is achieved and improvement is found when compared to the results obtained using the spin-image technique. The results demonstrate the feasibility of the proposed algorithm for registering 3D laser scanning data in close-range mapping applications to help with the generation of complete 3D models.
Mochalskyy, S.; Wünderlich, D.; Ruf, B.; Franzen, P.; Fantz, U.; Minea, T.
2014-02-01
Decreasing the co-extracted electron current while simultaneously keeping negative ion (NI) current sufficiently high is a crucial issue on the development plasma source system for ITER Neutral Beam Injector. To support finding the best extraction conditions the 3D Particle-in-Cell Monte Carlo Collision electrostatic code ONIX (Orsay Negative Ion eXtraction) has been developed. Close collaboration with experiments and other numerical models allows performing realistic simulations with relevant input parameters: plasma properties, geometry of the extraction aperture, full 3D magnetic field map, etc. For the first time ONIX has been benchmarked with commercial positive ions tracing code KOBRA3D. A very good agreement in terms of the meniscus position and depth has been found. Simulation of NI extraction with different e/NI ratio in bulk plasma shows high relevance of the direct negative ion extraction from the surface produced NI in order to obtain extracted NI current as in the experimental results from BATMAN testbed.
Sredar, Nripun; Ivers, Kevin M.; Queener, Hope M.; Zouridakis, George; Porter, Jason
2013-01-01
En face adaptive optics scanning laser ophthalmoscope (AOSLO) images of the anterior lamina cribrosa surface (ALCS) represent a 2D projected view of a 3D laminar surface. Using spectral domain optical coherence tomography images acquired in living monkey eyes, a thin plate spline was used to model the ALCS in 3D. The 2D AOSLO images were registered and projected onto the 3D surface that was then tessellated into a triangular mesh to characterize differences in pore geometry between 2D and 3D images. Following 3D transformation of the anterior laminar surface in 11 normal eyes, mean pore area increased by 5.1 ± 2.0% with a minimal change in pore elongation (mean change = 0.0 ± 0.2%). These small changes were due to the relatively flat laminar surfaces inherent in normal eyes (mean radius of curvature = 3.0 ± 0.5 mm). The mean increase in pore area was larger following 3D transformation in 4 glaucomatous eyes (16.2 ± 6.0%) due to their more steeply curved laminar surfaces (mean radius of curvature = 1.3 ± 0.1 mm), while the change in pore elongation was comparable to that in normal eyes (−0.2 ± 2.0%). This 3D transformation and tessellation method can be used to better characterize and track 3D changes in laminar pore and surface geometries in glaucoma. PMID:23847739
DEFF Research Database (Denmark)
Baruffi, Federico; Parenti, Paolo; Cacciatore, Francesco
2017-01-01
the replica molding technology. The method consists of obtaining a replica of the feature that is inaccessible for standard measurement devices and performing its indirect measurement. This paper examines the performance of a commercial replication media applied to the indirect measurement of micromilled...... components. Two specifically designed micromilled benchmark samples were used to assess the accuracy in replicating both surface texture and geometry. A 3D confocal microscope and a focus variation instrument were employed and the associated uncertainties were evaluated. The replication method proved...... to be suitable for characterizing micromilled surface texture even though an average overestimation in the nano-metric level of the Sa parameter was observed. On the other hand, the replicated geometry generally underestimated that of the master, often leading to a different measurement output considering...
Application of Volta potential mapping to determine metal surface defects
International Nuclear Information System (INIS)
Nazarov, A.; Thierry, D.
2007-01-01
As a rule, stress or fatigue cracks originate from various surface imperfections, such as pits, inclusions or locations showing a residual stress. It would be very helpful for material selection to be able to predict the likelihood of environment-assisted cracking or pitting corrosion. By using Scanning Kelvin Probe (the vibrating capacitor with a spatial resolution of 80 μm) the profiling of metal electron work function (Volta potential) in air is applied to the metal surfaces showing residual stress, MnS inclusions and wearing. The Volta potential is influenced by the energy of electrons at the Fermi level and drops generally across the metal/oxide/air interfaces. Inclusions (e.g. MnS) impair continuity of the passive film that locally decreases Volta potential. The stress applied gives rise to dislocations, microcracks and vacancies in the metal and the surface oxide. The defects decrease Volta and corrosion potentials; reduce the overvoltage for processes of passivity breakdown and anodic metal dissolution. These 'anodic' defects can be visualized in potential mapping that can help us to predict locations with higher risk of pitting corrosion or cracking
Photoinduced surface voltage mapping study for large perovskite single crystals
Energy Technology Data Exchange (ETDEWEB)
Liu, Xiaojing; Liu, Yucheng; Gao, Fei; Yang, Zhou [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Laboratory for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi' an 710062 (China); Liu, Shengzhong, E-mail: liusz@snnu.edu.cn [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Laboratory for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi' an 710062 (China); Dalian Institute of Chemical Physics, iChEM, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023 (China)
2016-05-02
Using a series of illumination sources, including white light (tungsten-halogen lamp), 445-nm, 532-nm, 635-nm, and 730-nm lasers, the surface photovoltage (SPV) images were mapped for centimeter-sized CH{sub 3}NH{sub 3}PbX{sub 3} (X = Cl, Br, I) perovskite single crystals using Kelvin probe force microscopy. The significant SPV signals were observed to be wavelength-dependent. We attribute the appreciable SPV to the built-in electric field in the space charge region. This study shines light into the understanding of photoinduced charge generation and separation processes at nanoscale to help advance the development of perovskite solar cells, optoelectronics, laser, photodetector, and light-emitting diode (LED).
Revised potentiometric-surface map, Yucca Mountain and vicinity, Nevada
International Nuclear Information System (INIS)
Ervin, E.M.; Luckey, R.R.; Burkhardt, D.J.
1994-01-01
The revised potentiometric-surface map presented in this report updates earlier maps of the Yucca Mountain area using mainly 1988 average water levels. Because of refinements in the corrections to the water-level measurements, these water levels have increased accuracy and precision over older values. The small-gradient area to the southeast of Yucca Mountain is contoured with a 0.25-meter interval and ranges in water-level altitude from 728.5 to 73 1.0 meters. Other areas with different water levels, to the north and west of Yucca Mountain, are illustrated with shaded patterns. The potentiometric surface can be divided into three regions: (1) A small-gradient area to the southeast of Yucca Mountain, which may be explained by flow through high-transmissivity rocks or low ground-water flux through the area; (2) A moderate-gradient area, on the western side of Yucca Mountain, where the water-level altitude ranges from 775 to 780 meters, and appears to be impeded by the Solitario Canyon Fault and a splay of that fault; and (3) A large-gradient area, to the north-northeast of Yucca Mountain, where water level altitude ranges from 738 to 1,035 meters, possibly as a result of a semi-perched groundwater system. Water levels from wells at Yucca Mountain were examined for yearly trends using linear least-squares regression. Data from five wells exhibited trends which were statistically significant, but some of those may be a result of slow equilibration of the water level from drilling in less permeable rocks. Adjustments for temperature and density changes in the deep wells with long fluid columns were attempted, but some of the adjusted data did not fit the surrounding data and, thus, were not used
Developments in special geometry
International Nuclear Information System (INIS)
Mohaupt, Thomas; Vaughan, Owen
2012-01-01
We review the special geometry of N = 2 supersymmetric vector and hypermultiplets with emphasis on recent developments and applications. A new formulation of the local c-map based on the Hesse potential and special real coordinates is presented. Other recent developments include the Euclidean version of special geometry, and generalizations of special geometry to non-supersymmetric theories. As applications we discuss the proof that the local r-map and c-map preserve geodesic completeness, and the construction of four- and five-dimensional static solutions through dimensional reduction over time. The shared features of the real, complex and quaternionic version of special geometry are stressed throughout.
Hely, Clement
During the past 50 years, the use of composite materials drastically increase, mainly thanks to the interest of aeronautical industries for these strong and lightweight materials. To improve the productivity of composite materials manufacturing some of the largest aeronautics companies began to develop automated processes such as Automated Fibre Placement (AFP). The AFP workcells currently used by the industry were mainly developed for production of large, nearly flat, plates with low curvatures such as aircraft fuselages. However, the fields of aeronautics and sport goods production begin nowadays to show an interest for manufacturing of smaller and more complex parts. The aim of the project in which this research takes place is to design a new AFP workcell and to develop new techniques allowing production of parts with small size and complex geometry. The work presented in this thesis focuses on the path planning on multi-axial revolution surfaces, e.g. Y-shaped tubes of constant circular cross section. Several path planning algorithms will be presented aiming at the exhaustive coverage of a mandrel with pre-impregnated (prepreg) composite tape. The methodology used in two of these algorithms is to individually cover each branch of the Y-shaped part with paths deriving from a helix. In the first one, the helix will be cut at the boundary between a branch and the junction region (algorithm HD) while in the second (algorithm HA) the pseudo-helix path can be adjusted to follow this boundary. These two methods were shown to have some drawbacks compromising their practical use and possibly leading to parts with diminished mechanical properties. To avoid these drawbacks, two others algorithms were developed with a new methodology. With them, the aim is to cover two branches of the Y-shape with a continuous course (i.e. without cut). The first one uses a well known strategy which defines plies with a constant fibre orientation. Parallel paths are then computed to
Kim, Youngdeuk
2011-04-15
The quantitative correlations between workpiece volume and melt pool geometry, as well as the flow and thermal features of the melt pool are established. Thermocapillary convections in melt pool with a deformable free surface are investigated with respect to surface shape and laser intensity. When the contact angle between the tangent to the top surface and the vertical wall at the hot center is acute, the free surface flattens, compared with that of the initial free surface. Otherwise, the free surface forms a bowl-like shape with a deep crater and a low peripheral rim when the contact angle at the hot center is obtuse. Increasing the workpiece volume at a fixed laser intensity and a negative radial height gradient cause linear decreases in the geometric size and magnitude of flow and temperature of the melt pool. Conversely, linear increases are observed with a positive radial height gradient. © 2011 American Institute of Chemical Engineers (AIChE).
Detailed mapping of surface units on Mars with HRSC color data
Combe, J.-Ph.; Wendt, L.; McCord, T. B.; Neukum, G.
2008-09-01
Introduction: Making use of HRSC color data Mapping outcrops of clays, sulfates and ferric oxides are basis information to derive the climatic, tectonic and volcanic evolution of Mars, especially the episodes related to the presence of liquid water. The challenge is to resolve spatially the outcrops and to distinguish these components from the globally-driven deposits like the iron oxide-rich bright red dust and the basaltic dark sands. The High Resolution Stereo Camera (HRSC) onboard Mars-Express has five color filters in the visible and near infrared that are designed for visual interpretation and mapping various surface units [1]. It provides also information on the topography at scale smaller than a pixel (roughness) thanks to the different geometry of observation for each color channel. The HRSC dataset is the only one that combines global coverage, 200 m/pixel spatial resolution or better and filtering colors of light. The present abstract is a work in progress (to be submitted to Planetary and Space Science) that shows the potential and limitations of HRSC color data as visual support and as multispectral images. Various methods are described from the most simple to more complex ones in order to demonstrate how to make use of the spectra, because of the specific steps of processing they require [2-4]. The objective is to broaden the popularity of HRSC color data, as they could be used more widely by the scientific community. Results prove that imaging spectrometry and HRSC color data complement each other for mapping outcrops types. Example regions of interest HRSC is theoretically sensitive to materials with absorption features in the visible and near-infrared up to 1 μm. Therefore, oxide-rich red dust and basalts (pyroxenes) can be mapped, as well as very bright components like water ice [5, 6]. Possible detection of other materials still has to be demonstrated. We first explore regions where unusual mineralogy appears clearly from spectral data. Hematite
(3+1)-dimensional topological phases and self-dual quantum geometries encoded on Heegaard surfaces
Energy Technology Data Exchange (ETDEWEB)
Dittrich, Bianca [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada)
2017-05-22
We apply the recently suggested strategy to lift state spaces and operators for (2+1)-dimensional topological quantum field theories to state spaces and operators for a (3+1)-dimensional TQFT with defects. We start from the (2+1)-dimensional Turaev-Viro theory and obtain a state space, consistent with the state space expected from the Crane-Yetter model with line defects. This work has important applications for quantum gravity as well as the theory of topological phases in (3+1) dimensions. It provides a self-dual quantum geometry realization based on a vacuum state peaked on a homogeneously curved geometry. The state spaces and operators we construct here provide also an improved version of the Walker-Wang model, and simplify its analysis considerably. We in particular show that the fusion bases of the (2+1)-dimensional theory lead to a rich set of bases for the (3+1)-dimensional theory. This includes a quantum deformed spin network basis, which in a loop quantum gravity context diagonalizes spatial geometry operators. We also obtain a dual curvature basis, that diagonalizes the Walker-Wang Hamiltonian. Furthermore, the construction presented here can be generalized to provide state spaces for the recently introduced dichromatic four-dimensional manifold invariants.
DEFF Research Database (Denmark)
Torralba, Marta; Jiménez, Roberto; Yagüe-Fabra, José A.
2018-01-01
micro-geometries as well (i.e., in the sub-mm dimensional range). However, there are different factors that may influence the CT process performance, being one of them the surface extraction technique used. In this paper, two different extraction techniques are applied to measure a complex miniaturized......The number of industrial applications of computed tomography (CT) for dimensional metrology in 100–103 mm range has been continuously increasing, especially in the last years. Due to its specific characteristics, CT has the potential to be employed as a viable solution for measuring 3D complex...... dental file by CT in order to analyze its contribution to the final measurement uncertainty in complex geometries at the mm to sub-mm scales. The first method is based on a similarity analysis: the threshold determination; while the second one is based on a gradient or discontinuity analysis: the 3D...
International Nuclear Information System (INIS)
Noordin, M.Y.; Kurniawan, D.; Sharif, S.
2007-01-01
Hard turning has been explored to be the finish machining operation for parts made of hardened steel. Its feasibility is determined partially by the quality of the resulting machined surface. This study evaluates the surface integrity of martensitic stainless steel (48 HRC) resulting from hard turning using coated carbide tool with wiper geometry at various cutting speed and feed and compares to that obtained using coated carbide tool with conventional geometry. The wiper coated carbide tool is able to produce machined surface which is of finer finish (Ra is finer than 0.4 μm at most cutting parameters) and yet is similarly inducing only minor microstructural alteration compared to its conventional counterpart. From the view of the chip morphology where continuous type of chip is desired rather than sawtooth chip type, the wiper tool generates continuous chip at almost similar range of cutting parameters compared to the case when using conventional tool. Additionally, the use of wiper tool also induces the preferred compressive residual stress at the machined surface. (author)
Kainulainen, J.; Juvela, M.; Alves, J.
2007-06-01
The giant molecular clouds (GMCs) of external galaxies can be mapped with sub-arcsecond resolution using multiband observations in the near-infrared. However, the interpretation of the observed reddening and attenuation of light, and their transformation into physical quantities, is greatly hampered by the effects arising from the unknown geometry and the scattering of light by dust particles. We examine the relation between the observed near-infrared reddening and the column density of the dust clouds. In this paper we particularly assess the feasibility of deriving the mass function of GMCs from near-infrared color excess data. We perform Monte Carlo radiative transfer simulations with 3D models of stellar radiation and clumpy dust distributions. We include the scattered light in the models and calculate near-infrared color maps from the simulated data. The color maps are compared with the true line-of-sight density distributions of the models. We extract clumps from the color maps and compare the observed mass function to the true mass function. For the physical configuration chosen in this study, essentially a face-on geometry, the observed mass function is a non-trivial function of the true mass function with a large number of parameters affecting its exact form. The dynamical range of the observed mass function is confined to 103.5dots 105.5 M_⊙ regardless of the dynamical range of the true mass function. The color maps are more sensitive in detecting the high-mass end of the mass function, and on average the masses of clouds are underestimated by a factor of ˜ 10 depending on the parameters describing the dust distribution. A significant fraction of clouds is expected to remain undetected at all masses. The simulations show that the cloud mass function derived from JHK color excess data using simple foreground screening geometry cannot be regarded as a one-to-one tracer of the underlying mass function.
Mapping of local argon impingement on a virtual surface: an insight for gas injection during FEBID
Energy Technology Data Exchange (ETDEWEB)
Wanzenboeck, H.D.; Hochleitner, G.; Mika, J.; Shawrav, M.M.; Gavagnin, M.; Bertagnolli, E. [Vienna University of Technology, Institute for Solid State Electronics, Vienna (Austria)
2014-12-15
During the last decades, focused electron beam induced deposition (FEBID) has become a successful approach for direct-write fabrication of nanodevices. Such a deposition technique relies on the precursor supply to the sample surface which is typically accomplished by a gas injection system using a tube-shaped injector nozzle. This precursor injection strategy implies a position-dependent concentration gradient on the surface, which affects the geometry and chemistry of the final nanodeposit. Although simulations already proposed the local distribution of nozzle-borne gas molecules impinging on the surface, this isolated step in the FEBID process has never been experimentally measured yet. This work experimentally investigates the local distribution of impinging gas molecules on the sample plane, isolating the direct impingement component from surface diffusion or precursor depletion by deposition. The experimental setup used in this work maps and quantifies the local impinging rate of argon gas over the sample plane. This setup simulates the identical conditions for a precursor molecule during FEBID. Argon gas was locally collected with a sniffer tube, which is directly connected to a residual gas analyzer for quantification. The measured distribution of impinging gas molecules showed a strong position dependence. Indeed, a 300-μm shift of the deposition area to a position further away from the impingement center spot resulted in a 50 % decrease in the precursor impinging rate on the surface area. With the same parameters, the precursor distribution was also simulated by a Monte Carlo software by Friedli and Utke and showed a good correlation between the empirical and the simulated precursor distribution. The results hereby presented underline the importance of controlling the local precursor flux conditions in order to obtain reproducible and comparable deposition results in FEBID. (orig.)
Mapping of local argon impingement on a virtual surface: an insight for gas injection during FEBID
International Nuclear Information System (INIS)
Wanzenboeck, H.D.; Hochleitner, G.; Mika, J.; Shawrav, M.M.; Gavagnin, M.; Bertagnolli, E.
2014-01-01
During the last decades, focused electron beam induced deposition (FEBID) has become a successful approach for direct-write fabrication of nanodevices. Such a deposition technique relies on the precursor supply to the sample surface which is typically accomplished by a gas injection system using a tube-shaped injector nozzle. This precursor injection strategy implies a position-dependent concentration gradient on the surface, which affects the geometry and chemistry of the final nanodeposit. Although simulations already proposed the local distribution of nozzle-borne gas molecules impinging on the surface, this isolated step in the FEBID process has never been experimentally measured yet. This work experimentally investigates the local distribution of impinging gas molecules on the sample plane, isolating the direct impingement component from surface diffusion or precursor depletion by deposition. The experimental setup used in this work maps and quantifies the local impinging rate of argon gas over the sample plane. This setup simulates the identical conditions for a precursor molecule during FEBID. Argon gas was locally collected with a sniffer tube, which is directly connected to a residual gas analyzer for quantification. The measured distribution of impinging gas molecules showed a strong position dependence. Indeed, a 300-μm shift of the deposition area to a position further away from the impingement center spot resulted in a 50 % decrease in the precursor impinging rate on the surface area. With the same parameters, the precursor distribution was also simulated by a Monte Carlo software by Friedli and Utke and showed a good correlation between the empirical and the simulated precursor distribution. The results hereby presented underline the importance of controlling the local precursor flux conditions in order to obtain reproducible and comparable deposition results in FEBID. (orig.)
Mapping of local argon impingement on a virtual surface: an insight for gas injection during FEBID
Wanzenboeck, H. D.; Hochleitner, G.; Mika, J.; Shawrav, M. M.; Gavagnin, M.; Bertagnolli, E.
2014-12-01
During the last decades, focused electron beam induced deposition (FEBID) has become a successful approach for direct-write fabrication of nanodevices. Such a deposition technique relies on the precursor supply to the sample surface which is typically accomplished by a gas injection system using a tube-shaped injector nozzle. This precursor injection strategy implies a position-dependent concentration gradient on the surface, which affects the geometry and chemistry of the final nanodeposit. Although simulations already proposed the local distribution of nozzle-borne gas molecules impinging on the surface, this isolated step in the FEBID process has never been experimentally measured yet. This work experimentally investigates the local distribution of impinging gas molecules on the sample plane, isolating the direct impingement component from surface diffusion or precursor depletion by deposition. The experimental setup used in this work maps and quantifies the local impinging rate of argon gas over the sample plane. This setup simulates the identical conditions for a precursor molecule during FEBID. Argon gas was locally collected with a sniffer tube, which is directly connected to a residual gas analyzer for quantification. The measured distribution of impinging gas molecules showed a strong position dependence. Indeed, a 300-µm shift of the deposition area to a position further away from the impingement center spot resulted in a 50 % decrease in the precursor impinging rate on the surface area. With the same parameters, the precursor distribution was also simulated by a Monte Carlo software by Friedli and Utke and showed a good correlation between the empirical and the simulated precursor distribution. The results hereby presented underline the importance of controlling the local precursor flux conditions in order to obtain reproducible and comparable deposition results in FEBID.
Burdette, A C
1971-01-01
Analytic Geometry covers several fundamental aspects of analytic geometry needed for advanced subjects, including calculus.This book is composed of 12 chapters that review the principles, concepts, and analytic proofs of geometric theorems, families of lines, the normal equation of the line, and related matters. Other chapters highlight the application of graphing, foci, directrices, eccentricity, and conic-related topics. The remaining chapters deal with the concept polar and rectangular coordinates, surfaces and curves, and planes.This book will prove useful to undergraduate trigonometric st
Berger, Marcel
2010-01-01
Both classical geometry and modern differential geometry have been active subjects of research throughout the 20th century and lie at the heart of many recent advances in mathematics and physics. The underlying motivating concept for the present book is that it offers readers the elements of a modern geometric culture by means of a whole series of visually appealing unsolved (or recently solved) problems that require the creation of concepts and tools of varying abstraction. Starting with such natural, classical objects as lines, planes, circles, spheres, polygons, polyhedra, curves, surfaces,
Energy Technology Data Exchange (ETDEWEB)
Ono, K [Mie Univ., Mie (Japan). Faculty of Biological and Resources
1991-12-01
In case a landslide occurs on a slope, grasping the area of influence (location and shape of the slip surface) is required to take a countermeasure against landslides. This paper describes a method developed by the author for predicting a slip surface by utilizing fuzzy theory. The method predicts a slip surface from observations on ground surface displacement vectors, and the validity of the method has been verified through slip experiments conducted on slopes with a centrifugal model experiment device. The developed method for predicting the location of a slip surface well matches the experiment results, indicating the validity of the method. It has been found that the difference between the predicted and observed locations of a slip surface mainly is due to the error of the prediction in the starting and ending locations of the slip surface. It is also pointed out that, in order to improve the prediction of the shape of a slip surface, the observation density must be increased at the location where the shape of the slip surface strongly varies, since the direction of the slip surface is determined by the direction of the ground surface displacement vectors. 4 refs., 7 figs.
A statistical model for the wettability of surfaces with heterogeneous pore geometries
Brockway, Lance; Taylor, Hayden
2016-10-01
We describe a new approach to modeling the wetting behavior of micro- and nano-textured surfaces with varying degrees of geometrical heterogeneity. Surfaces are modeled as pore arrays with a Gaussian distribution of sidewall reentrant angles and a characteristic wall roughness. Unlike conventional wettability models, our model considers the fraction of a surface’s pores that are filled at any time, allowing us to capture more subtle dependences of a liquid’s apparent contact angle on its surface tension. The model has four fitting parameters and is calibrated for a particular surface by measuring the apparent contact angles between the surface and at least four probe liquids. We have calibrated the model for three heterogeneous nanoporous surfaces that we have fabricated: a hydrothermally grown zinc oxide, a film of polyvinylidene fluoride (PVDF) microspheres formed by spinodal decomposition, and a polytetrafluoroethylene (PTFE) film with pores defined by sacrificial polystyrene microspheres. These three surfaces show markedly different dependences of a liquid’s apparent contact angle on the liquid’s surface tension, and the results can be explained by considering geometric variability. The highly variable PTFE pores yield the most gradual variation of apparent contact angle with probe liquid surface tension. The PVDF microspheres are more regular in diameter and, although connected in an irregular manner, result in a much sharper transition from non-wetting to wetting behavior as surface tension reduces. We also demonstrate, by terminating porous zinc oxide with three alternative hydrophobic molecules, that a single geometrical model can capture a structure’s wetting behavior for multiple surface chemistries and liquids. Finally, we contrast our results with those from a highly regular, lithographically-produced structure which shows an extremely sharp dependence of wettability on surface tension. This new model could be valuable in designing and
International Nuclear Information System (INIS)
Fujii, A; Hayashi, S; Fujii, S; Yanagi, K
2014-01-01
This paper deals with the functional performance of optical surface texture measuring instruments on the market. It is well known that their height response curves against certain referential geometry are not always identical to each other. So, a more precise study on the optical instrument's characteristics is greatly needed. Firstly, we developed a new simulation tool using a finite-difference time-domain technique, which enables the prediction of the height response curve against the fundamental surface geometry in the case of the confocal laser scanning microscope. Secondly, by utilizing this new simulation tool, measurement results, including outliers, were compared with the analytical simulation results. The comparison showed the consistency, which indicates that necessary conditions of surface measurement standards for verifying the instrument performance can be established. Consequently, we suggest that the maximum measurable slope angle must be added to evaluation subjects as significant metrological characteristics of measuring instruments, along with the lateral period limit. Finally, we propose a procedure to determine the lateral period limit in an ISO standard. (paper)
Heat capacity mapping mission (HCMM) thermal surface water mapping and its correlation to LANDSAT
International Nuclear Information System (INIS)
Colvocoresses, A.P.
1980-03-01
Graphics are presented which show HCMM mapped water-surface temperature in Lake Anna, a 13,000 dendrically-shaped lake which provides cooling for a nuclear power plant in Virginia. The HCMM digital data, produced by NASA were processed by NOAA/NESS into image and line-printer form. A LANDSAT image of the lake illustrates the relationship between MSS band 7 data and the HCMM data as processed by the NASA image processing facility which transforms the data to the same distortion-free hotline oblique Mercator projection. Spatial correlation of the two images is relatively simple by either digital or analog means and the HCMM image has a potential accuracy approaching the 80 m of the original LANDSAT data. While it is difficult to get readings that are not diluted by radiation from cooler adjacent land areas in narrow portions of the lake, digital data indicated by the line-printer display five different temperatures for open-water areas. Where the water surface response was not diluted by land areas, the temperature difference recorded by HCMM corresponds to in situ readings with rsme on the order of 1 C
Indian Academy of Sciences (India)
algebraic geometry but also in related fields like number theory. ... every vector bundle on the affine space is trivial. (equivalently ... les on a compact Riemann surface to unitary rep- ... tial geometry and topology and was generalised in.
Cancer Risk Map for the Surface of Mars
Kim, Myung-Hee Y.; Cucinotta, Francis A.
2011-01-01
We discuss calculations of the median and 95th percentile cancer risks on the surface of Mars for different solar conditions. The NASA Space Radiation Cancer Risk 2010 model is used to estimate gender and age specific cancer incidence and mortality risks for astronauts exploring Mars. Organ specific fluence spectra and doses for large solar particle events (SPE) and galactic cosmic rays (GCR) at various levels of solar activity are simulated using the HZETRN/QMSFRG computer code, and the 2010 version of the Badhwar and O Neill GCR model. The NASA JSC propensity model of SPE fluence and occurrence is used to consider upper bounds on SPE fluence for increasing mission lengths. In the transport of particles through the Mars atmosphere, a vertical distribution of Mars atmospheric thickness is calculated from the temperature and pressure data of Mars Global Surveyor, and the directional cosine distribution is implemented to describe the spherically distributed atmospheric distance along the slant path at each elevation on Mars. The resultant directional shielding by Mars atmosphere at each elevation is coupled with vehicle and body shielding for organ dose estimates. Astronaut cancer risks are mapped on the global topography of Mars, which was measured by the Mars Orbiter Laser Altimeter. Variation of cancer risk on the surface of Mars is due to a 16-km elevation range, and the large difference is obtained between the Tharsis Montes (Ascraeus, Pavonis, and Arsia) and the Hellas impact basin. Cancer incidence risks are found to be about 2-fold higher than mortality risks with a disproportionate increase in skin and thyroid cancers for all astronauts and breast cancer risk for female astronauts. The number of safe days on Mars to be below radiation limits at the 95th percent confidence level is reported for several Mission design scenarios.
A coastal surface seawater analyzer for nitrogenous nutrient mapping
Masserini, Robert T.; Fanning, Kent A.; Hendrix, Steven A.; Kleiman, Brittany M.
2017-11-01
Satellite-data-based modeling of chlorophyll indicates that ocean waters in the mesosphere category are responsible for the majority of oceanic net primary productivity. Coastal waters, which frequently have surface chlorophyll values in the mesosphere range and have strong horizontal chlorophyll gradients and large temporal variations. Thus programs of detailed coastal nutrient surveys are essential to the study of the dynamics of oceanic net primary productivity, along with land use impacts on estuarine and coastal ecosystems. The degree of variability in these regions necessitates flexible instrumentation capable of near real-time analysis to detect and monitor analytes of interest. This work describes the development of a portable coastal surface seawater analyzer for nutrient mapping that can simultaneously elucidate with high resolution the distribution of nitrate, nitrite, and ammonium - the three principal nitrogenous inorganic nutrients in coastal systems. The approach focuses on the use of pulsed xenon flash lamps to construct an analyzer which can be adapted to any automated chemistry with fluorescence detection. The system has two heaters, on-the-fly standardization, on-board data logging, an independent 24 volt direct current power supply, internal local operating network, a 12 channel peristaltic pump, four rotary injection/selection valves, and an intuitive graphical user interface. Using the methodology of Masserini and Fanning (2000) the detection limits for ammonium, nitrite, and nitrate plus nitrite were 11, 10, and 22 nM, respectively. A field test of the analyzer in Gulf of Mexico coastal waters demonstrated its ability to monitor and delineate the complexity of inorganic nitrogen nutrient enrichments within a coastal system.
IRAS surface brightness maps of reflection nebulae in the Pleiades
Castelaz, Michael W.; Werner, M. W.; Sellgren, K.
1987-01-01
Surface brightness maps at 12, 25, 60, and 100 microns were made of a 2.5 deg x 2.5 deg area of the reflection nebulae in the Pleiades by coadding IRAS scans of this region. Emission is seen surrounding 17 Tau, 20 Tau, 23 Tau, and 25 Tau in all four bands, coextensive with the visible reflection nebulosity, and extending as far as 30 arcminutes from the illuminating stars. The infrared energy distributions of the nebulae peak in the 100 micron band, but up to 40 percent of the total infrared power lies in the 12 and 25 micron bands. The brightness of the 12 and 25 micron emission and the absence of temperature gradients at these wavelengths are inconsistent with the predictions of equilibrium thermal emission models. The emission at these wavelengths appears to be the result of micron nonequilibrium emission from very small grains, or from molecules consisting of 10-100 carbon atoms, which have been excited by ultraviolet radiation from the illuminating stars.
Control of bacterial biofilm growth on surfaces by nanostructural mechanics and geometry
International Nuclear Information System (INIS)
Epstein, A K; Hochbaum, A I; Kim, Philseok; Aizenberg, J
2011-01-01
Surface-associated communities of bacteria, called biofilms, pervade natural and anthropogenic environments. Mature biofilms are resistant to a wide range of antimicrobial treatments and therefore pose persistent pathogenic threats. The use of surface chemistry to inhibit biofilm growth has been found to only transiently affect initial attachment. In this work, we investigate the tunable effects of physical surface properties, including high-aspect-ratio (HAR) surface nanostructure arrays recently reported to induce long-range spontaneous spatial patterning of bacteria on the surface. The functional parameters and length scale regimes that control such artificial patterning for the rod-shaped pathogenic species Pseudomonas aeruginosa are elucidated through a combinatorial approach. We further report a crossover regime of biofilm growth on a HAR nanostructured surface versus the nanostructure effective stiffness. When the 'softness' of the hair-like nanoarray is increased beyond a threshold value, biofilm growth is inhibited as compared to a flat control surface. This result is consistent with the mechanoselective adhesion of bacteria to surfaces. Therefore by combining nanoarray-induced bacterial patterning and modulating the effective stiffness of the nanoarray—thus mimicking an extremely compliant flat surface—bacterial mechanoselective adhesion can be exploited to control and inhibit biofilm growth.
Orientational Order on Surfaces: The Coupling of Topology, Geometry, and Dynamics
Nestler, M.; Nitschke, I.; Praetorius, S.; Voigt, A.
2018-02-01
We consider the numerical investigation of surface bound orientational order using unit tangential vector fields by means of a gradient flow equation of a weak surface Frank-Oseen energy. The energy is composed of intrinsic and extrinsic contributions, as well as a penalization term to enforce the unity of the vector field. Four different numerical discretizations, namely a discrete exterior calculus approach, a method based on vector spherical harmonics, a surface finite element method, and an approach utilizing an implicit surface description, the diffuse interface method, are described and compared with each other for surfaces with Euler characteristic 2. We demonstrate the influence of geometric properties on realizations of the Poincaré-Hopf theorem and show examples where the energy is decreased by introducing additional orientational defects.
OPUS - Outer Planets Unified Search with Enhanced Surface Geometry Parameters - Not Just for Rings
Gordon, Mitchell; Showalter, Mark Robert; Ballard, Lisa; Tiscareno, Matthew S.; Heather, Neil
2016-10-01
In recent years, with the massive influx of data into the PDS from a wide array of missions and instruments, finding the precise data you need has been an ongoing challenge. For remote sensing data obtained from Jupiter to Pluto, that challenge is being addressed by the Outer Planets Unified Search, more commonly known as OPUS.OPUS is a powerful search tool available at the PDS Ring-Moon Systems Node (RMS) - formerly the PDS Rings Node. While OPUS was originally designed with ring data in mind, its capabilities have been extended to include all of the targets within an instrument's field of view. OPUS provides preview images of search results, and produces a zip file for easy download of selected products, including a table of user specified metadata. For Cassini ISS and Voyager ISS we have generated and include calibrated versions of every image.Currently OPUS supports data returned by Cassini ISS, UVIS, VIMS, and CIRS (Saturn data through June 2010), New Horizons Jupiter LORRI, Galileo SSI, Voyager ISS and IRIS, and Hubble (ACS, WFC3 and WFPC2).At the RMS Node, we have developed and incorporated into OPUS detailed geometric metadata, based on the most recent SPICE kernels, for all of the bodies in the Cassini Saturn observations. This extensive set of geometric metadata is unique to the RMS Node and enables search constraints such as latitudes and longitudes (Saturn, Titan, and icy satellites), viewing and illumination geometry (phase, incidence and emission angles), and distances and resolution.Our near term plans include adding the full set of Cassini CIRS Saturn data (with enhanced geometry), New Horizons MVIC Jupiter encounter images, New Horizons LORRI and MVIC Pluto data, HST STIS observations, and Cassini and Voyager ring occultations. We also plan to develop enhanced geometric metadata for the New Horizons LORRI and MVIC instruments for both the Jupiter and the Pluto encounters.OPUS: http://pds-rings.seti.org/search/
Lechmann, Alessandro; Mair, David; Nishiyama, Ryuichi; Ariga, Akitaka; Ariga, Tomoko; Ereditato, Antonio; Scampoli, Paola; Vladymyrov, Mykhailo; Schlunegger, Fritz
2016-04-01
In recent years, muon radiography has been successfully applied to tackle geological issues and has enjoyed an increasing interest, mainly because this methodology enriches the geophysical arsenal by another shallow subsurface imaging tool that may give independent constraints on material density. Muons that originate from the collision of cosmic particles with Earth's atmosphere are able to penetrate the material in question and can finally be recorded by a detector. The irradiation intensity can then be inverted to the density of the traversed material. Various successful two-dimensional attempts have already been made to image e.g. magma chambers inside volcanoes (Lesparre et al., 2012; Nishiyama et al., 2014; Tanaka et al., 2005), but this method has yet to be applied for mapping the base of glaciers, where the density contrasts between ice and underlying bedrock are even greater than those between magma and host rock. While a high Alpine setup limits the possibilities to deploy traditional geophysical methods for surveying the base of glaciers (because of inaccessible terrain, poor infrastructure or the presence of water in the ice), muon radiography might prove to be a promising alternative. The muon intensity data from stereo observation can be related to the three-dimensional geometry of the interface between the glacier and its bedrock. Given a suitable input model, this relation can be solved within the framework of geophysical inverse problems. The final model then gives geologists invaluable information on erosional mechanisms underneath active glaciers, as this has not yet been observed. We test this methodology for a site within the Jungfrau region, situated in the central Swiss Alps. Our first goal is to demonstrate the feasibility of the method through a case study at the Eiger glacier, starting from a toy model in a first phase and continuing with real data in a second phase. For this purpose, we installed cosmic-ray detectors at two sites inside
Simultaneous Localization and Mapping for Planetary Surface Mobility, Phase I
National Aeronautics and Space Administration — ProtoInnovations, LLC and Carnegie Mellon University have formed a partnership to commercially develop localization and mapping technologies for planetary rovers....
Junwei Ma; Han Yuan; Sunderam, Sridhar; Besio, Walter; Lei Ding
2017-07-01
Neural activity inside the human brain generate electrical signals that can be detected on the scalp. Electroencephalograph (EEG) is one of the most widely utilized techniques helping physicians and researchers to diagnose and understand various brain diseases. Due to its nature, EEG signals have very high temporal resolution but poor spatial resolution. To achieve higher spatial resolution, a novel tri-polar concentric ring electrode (TCRE) has been developed to directly measure Surface Laplacian (SL). The objective of the present study is to accurately calculate SL for TCRE based on a realistic geometry head model. A locally dense mesh was proposed to represent the head surface, where the local dense parts were to match the small structural components in TCRE. Other areas without dense mesh were used for the purpose of reducing computational load. We conducted computer simulations to evaluate the performance of the proposed mesh and evaluated possible numerical errors as compared with a low-density model. Finally, with achieved accuracy, we presented the computed forward lead field of SL for TCRE for the first time in a realistic geometry head model and demonstrated that it has better spatial resolution than computed SL from classic EEG recordings.
Effects of the divertor tile geometries and magnetic field angles on the heat fluxes to the surface
Energy Technology Data Exchange (ETDEWEB)
Hu, Wanpeng; Sang, Chaofeng; Sun, Zhenyue; Wang, Dezhen, E-mail: wangdez@dlut.edu.cn
2017-03-15
Highlights: • Simulation of the plasma behaviors in the divertor gap region is done by using a 2d3 v Particle-In-Cell code. • Heat fluxes on the wall surface in different gap geometries are studied. • The effect of the magnetic field angle on the heat flux is investigated. - Abstract: A two dimension-in-space and three dimension-in-velocity (2d3v) Particle-In-Cell (PIC) code is applied to investigate the plasma behaviors at the divertor gaps region in this work. Electron and D{sup +} ion fluxes to the tile surface in the poloidal and toroidal gaps for different shaped edges are compared to demonstrate the optimized tile geometry. For poloidal gap, shaped edge in the shadowing side makes more ions penetrate into the gap, while shaped edge in the wetted side can mitigate the peak flux value. For toroidal gap, most ions entering the gap impinge on the side tile mainly due to the E × B drift, and shaped wetted edges also can mitigate the peak heat fluxes. In addition, effects of magnetic field inclination angle from toroidal direction on the plasma behaviors are simulated for poloidal and toroidal gaps, respectively. It is found that the magnetic field angles don’t influence the plasma behaviors in poloidal gap; while significant changes have been observed in the toroidal gap.
Symplectic geometry on moduli spaces of holomorphic bundles over complex surfaces
Khesin, Boris; Rosly, Alexei
2000-01-01
We give a comparative description of the Poisson structures on the moduli spaces of flat connections on real surfaces and holomorphic Poisson structures on the moduli spaces of holomorphic bundles on complex surfaces. The symplectic leaves of the latter are classified by restrictions of the bundles to certain divisors. This can be regarded as fixing a "complex analogue of the holonomy" of a connection along a "complex analogue of the boundary" in analogy with the real case.
International Nuclear Information System (INIS)
Bosimini, E.; Galli, M.; Guagliumi, G.; Giubbini, R.; Tavazzi, L.
1991-01-01
In patients with coronary artery disease, radionuclide investigations have documented a high incidence of mental stress-induced myocardial ischemia in the absence of significant electrocardiographic changes and/or angina. To investigate the causes of the low electrocardiographic sensitivity, we recorded body surface maps during mental arithmetic in 22 normal volunteers and 37 postinfarction patients with residual exercise ischemia. Myocardial perfusion was studied with thallium-201 or technetium-99 (SESTAMIBI) planar scans. In 14 patients, body surface maps were also recorded during atrial pacing at the heart rate values achieved during mental stress. While taking the body surface maps, the area from J point to 80 msec after this point (ST-80) was analyzed by integral maps, difference maps, and departure maps. The body surface mapping criteria for ischemia were a new negative area on the integral maps, a negative potential of more than 2 SD from mean normal values on the difference maps, and a negative departure index of more than 2. Scintigraphy showed asymptomatic myocardial hypoperfusion in 33 patients. Eight patients had significant ST segment depression. The ST-80 integral and difference maps identified 17 ischemic patients. Twenty-four patients presented abnormal departure maps. One patient presented ST depression and abnormal body surface maps without reversible tracer defect. In 14 of 14 patients, atrial pacing did not reproduce the body surface map abnormalities. The analyses of the other electrocardiographic variables showed that in patients with mental stress-induced perfusion defects, only changes of T apex-T offset (aT-eT) interval in Frank leads and changes of maximum negative potential value of aT-eT integral maps significantly differed from those of normal subjects
Mapping the global depth to bedrock for land surface modelling
Shangguan, W.; Hengl, T.; Yuan, H.; Dai, Y. J.; Zhang, S.
2017-12-01
Depth to bedrock serves as the lower boundary of land surface models, which controls hydrologic and biogeochemical processes. This paper presents a framework for global estimation of Depth to bedrock (DTB). Observations were extracted from a global compilation of soil profile data (ca. 130,000 locations) and borehole data (ca. 1.6 million locations). Additional pseudo-observations generated by expert knowledge were added to fill in large sampling gaps. The model training points were then overlaid on a stack of 155 covariates including DEM-based hydrological and morphological derivatives, lithologic units, MODIS surfacee reflectance bands and vegetation indices derived from the MODIS land products. Global spatial prediction models were developed using random forests and Gradient Boosting Tree algorithms. The final predictions were generated at the spatial resolution of 250m as an ensemble prediction of the two independently fitted models. The 10-fold cross-validation shows that the models explain 59% for absolute DTB and 34% for censored DTB (depths deep than 200 cm are predicted as 200 cm). The model for occurrence of R horizon (bedrock) within 200 cm does a good job. Visual comparisons of predictions in the study areas where more detailed maps of depth to bedrock exist show that there is a general match with spatial patterns from similar local studies. Limitation of the data set and extrapolation in data spare areas should not be ignored in applications. To improve accuracy of spatial prediction, more borehole drilling logs will need to be added to supplement the existing training points in under-represented areas.
Remote compositional mapping of lunar titanium and surface maturity
Johnson, J. R.; Larson, S. M.; Singer, Robert B.
1991-01-01
Lunar ilmenite (FeTiO3) is a potential resource capable of providing oxygen for life support and spacecraft propellant for future lunar bases. Estimates of TiO2 content in mature mare soils can be made using an empirical relation between the 400/500 nm reflectance ratio and TiO2 wt percent. A TiO2 abundance map was constructed for the entire near-side lunar maria accurate to + or - 2 wt percent TiO2 using CCD images obtained at the Tumamoc Hill 0.5 m telescope in Tucson, employing bandpass filters centered at 400 and 560 nm. Highest TiO2 regions in the maria are located in western Mare Tranquillitatis. Greater contrast differences between regions on the lunar surface can be obtained using 400/730 nm ratio images. The relation might well be refined to accommodate this possibly more sensitive indicator of TiO2 content. Another potential lunar resource is solar wind-implanted He-3 which may be used as a fuel for fusion reactors. Relative soil maturity, as determined by agglutinate content, can be estimated from 950/560 nm ration images. Immature soils appear darker in this ratio since such soils contain abundant pyroxene grains which cause strong absorption centered near 950 nm due Fe(2+) crystal field transitions. A positive correlation exists between the amount of He-3 and TiO2 content in lunar soils, suggesting that regions high in TiO2 should also be high in He-3. Reflectance spectrophotometry in the region 320 to 870 nm was also obtained for several regions. Below about 340 nm, these spectra show variations in relative reflectance that are caused by as yet unassigned near-UV absorptions due to compositional differences.
Raman mapping of intact biofilms on stainless steel surfaces
Each slide under the Raman Microscope was mapped for approximately 18.5 hours with a dimension of 36x36 that provides a greater result compared to doing a smaller dimension scan. The results from the Raman Mapping show the location and position of how the bacteria are growing scattered or straight a...
Critical coupling of surface plasmons in graphene attenuated total reflection geometry
Energy Technology Data Exchange (ETDEWEB)
Cuevas, Mauro, E-mail: cuevas@df.uba.ar [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Facultad de Ingeniería y Tecnología Informática, Universidad de Belgrano, Villanueva 1324, C1426BMJ, Buenos Aires (Argentina); Grupo de Electromagnetismo Aplicado, Departamento de Física, FCEN, Universidad de Buenos Aires and IFIBA, Ciudad Universitaria, Pabellón I, C1428EHA, Buenos Aires (Argentina)
2016-12-09
We study the optical response of an attenuated total reflection (ATR) structure in Otto configuration with graphene sheet, paying especial attention to the occurrence of total absorption. Our results show that due to excitation of surface plasmons on the graphene sheet, two different conditions of total absorption may occur. At these conditions, the energy loss of the surface plasmon by radiation is equal to its energy loss by absorption into the graphene sheet. We give necessary conditions on ATR parameters for the existence of total absorption. - Highlights: • Attenuated total reflection (ATR) structure with graphene sheet. • Surface plasmons and power matched condition. • Necessary conditions on ATR parameters for the existence of total absorption.
Critical coupling of surface plasmons in graphene attenuated total reflection geometry
International Nuclear Information System (INIS)
Cuevas, Mauro
2016-01-01
We study the optical response of an attenuated total reflection (ATR) structure in Otto configuration with graphene sheet, paying especial attention to the occurrence of total absorption. Our results show that due to excitation of surface plasmons on the graphene sheet, two different conditions of total absorption may occur. At these conditions, the energy loss of the surface plasmon by radiation is equal to its energy loss by absorption into the graphene sheet. We give necessary conditions on ATR parameters for the existence of total absorption. - Highlights: • Attenuated total reflection (ATR) structure with graphene sheet. • Surface plasmons and power matched condition. • Necessary conditions on ATR parameters for the existence of total absorption.
Global aspects of complex geometry
Catanese, Fabrizio; Huckleberry, Alan T
2006-01-01
Present an overview of developments in Complex Geometry. This book covers topics that range from curve and surface theory through special varieties in higher dimensions, moduli theory, Kahler geometry, and group actions to Hodge theory and characteristic p-geometry.
Method for Pre-Conditioning a Measured Surface Height Map for Model Validation
Sidick, Erkin
2012-01-01
This software allows one to up-sample or down-sample a measured surface map for model validation, not only without introducing any re-sampling errors, but also eliminating the existing measurement noise and measurement errors. Because the re-sampling of a surface map is accomplished based on the analytical expressions of Zernike-polynomials and a power spectral density model, such re-sampling does not introduce any aliasing and interpolation errors as is done by the conventional interpolation and FFT-based (fast-Fourier-transform-based) spatial-filtering method. Also, this new method automatically eliminates the measurement noise and other measurement errors such as artificial discontinuity. The developmental cycle of an optical system, such as a space telescope, includes, but is not limited to, the following two steps: (1) deriving requirements or specs on the optical quality of individual optics before they are fabricated through optical modeling and simulations, and (2) validating the optical model using the measured surface height maps after all optics are fabricated. There are a number of computational issues related to model validation, one of which is the "pre-conditioning" or pre-processing of the measured surface maps before using them in a model validation software tool. This software addresses the following issues: (1) up- or down-sampling a measured surface map to match it with the gridded data format of a model validation tool, and (2) eliminating the surface measurement noise or measurement errors such that the resulted surface height map is continuous or smoothly-varying. So far, the preferred method used for re-sampling a surface map is two-dimensional interpolation. The main problem of this method is that the same pixel can take different values when the method of interpolation is changed among the different methods such as the "nearest," "linear," "cubic," and "spline" fitting in Matlab. The conventional, FFT-based spatial filtering method used to
Lu, Yang; Steele-Dunne, Susan C.; Farhadi, Leila; van de Giesen, Nick
2017-12-01
Surface heat fluxes play a crucial role in the surface energy and water balance. In situ measurements are costly and difficult, and large-scale flux mapping is hindered by surface heterogeneity. Previous studies have demonstrated that surface heat fluxes can be estimated by assimilating land surface temperature (LST) and soil moisture to determine two key parameters: a neutral bulk heat transfer coefficient (CHN) and an evaporative fraction (EF). Here a methodology is proposed to estimate surface heat fluxes by assimilating Soil Moisture Active Passive (SMAP) soil moisture data and Geostationary Operational Environmental Satellite (GOES) LST data into a dual-source (DS) model using a hybrid particle assimilation strategy. SMAP soil moisture data are assimilated using a particle filter (PF), and GOES LST data are assimilated using an adaptive particle batch smoother (APBS) to account for the large gap in the spatial and temporal resolution. The methodology is implemented in an area in the U.S. Southern Great Plains. Assessment against in situ observations suggests that soil moisture and LST estimates are in better agreement with observations after assimilation. The RMSD for 30 min (daytime) flux estimates is reduced by 6.3% (8.7%) and 31.6% (37%) for H and LE on average. Comparison against a LST-only and a soil moisture-only assimilation case suggests that despite the coarse resolution, assimilating SMAP soil moisture data is not only beneficial but also crucial for successful and robust flux estimation, particularly when the uncertainties in the model estimates are large.
Characterization and extraction of the synaptic apposition surface for synaptic geometry analysis
Morales, Juan; Rodríguez, Angel; Rodríguez, José-Rodrigo; DeFelipe, Javier; Merchán-Pérez, Angel
2013-01-01
Geometrical features of chemical synapses are relevant to their function. Two critical components of the synaptic junction are the active zone (AZ) and the postsynaptic density (PSD), as they are related to the probability of synaptic release and the number of postsynaptic receptors, respectively. Morphological studies of these structures are greatly facilitated by the use of recent electron microscopy techniques, such as combined focused ion beam milling and scanning electron microscopy (FIB/SEM), and software tools that permit reconstruction of large numbers of synapses in three dimensions. Since the AZ and the PSD are in close apposition and have a similar surface area, they can be represented by a single surface—the synaptic apposition surface (SAS). We have developed an efficient computational technique to automatically extract this surface from synaptic junctions that have previously been three-dimensionally reconstructed from actual tissue samples imaged by automated FIB/SEM. Given its relationship with the release probability and the number of postsynaptic receptors, the surface area of the SAS is a functionally relevant measure of the size of a synapse that can complement other geometrical features like the volume of the reconstructed synaptic junction, the equivalent ellipsoid size and the Feret's diameter. PMID:23847474
A DFT study on benzene adsorption over tungsten sulfides: surface model and adsorption geometries
Koide, R.; Hensen, E.J.M.; Paul, J.F.; Cristol, S.; Payen, E.; Nakamura, H.; Santen, van R.A.
2007-01-01
Benzene adsorption on a WS2(100) surface was studied by ab initio periodic DFT computations. Benzene adsorption is facile on the bridge site of the bare W edge via ¿2 or ¿3 coordination. Taking into account the stable configuration at the W edge under typical hydrotreating reaction conditions (623
International Nuclear Information System (INIS)
Jarvis, P.D.; Thompson, G.
1987-04-01
We establish the equivalence between the extended BRST invariances, and the conventional Slavnov-Taylor transformations together with a new ''dual'' analogue. However, the latter (a non-local gauge transformation, generating an A-dependent translation of the gauge-fixing surface) is not an invariance of the Faddeev-Popov determinant, contrary to the published claim. (author)
Ciarlet, Philippe G
2007-01-01
This book gives the basic notions of differential geometry, such as the metric tensor, the Riemann curvature tensor, the fundamental forms of a surface, covariant derivatives, and the fundamental theorem of surface theory in a selfcontained and accessible manner. Although the field is often considered a classical one, it has recently been rejuvenated, thanks to the manifold applications where it plays an essential role. The book presents some important applications to shells, such as the theory of linearly and nonlinearly elastic shells, the implementation of numerical methods for shells, and
Surface geometry of three packable and one hybrid composite after polishing.
Jung, Martin; Bruegger, Hilka; Klimek, Joachim
2003-01-01
This study evaluated the surface quality of four composite materials after polishing with six different polishing techniques. Eighty specimens were made using three packable composites (Definite/Degussa, SureFil/ Dentsply and Solitaire/Heraeus-Kulzer) and one hybrid composite (Herculite XRV/Kerr). Five specimens of each material were polished using flexible Sof-Lex discs. The remaining 75 specimens of each composite were prepared using three finishing protocols: a single 30 microm diamond (n = 25), two finishing diamonds (30/20 microm; n = 25) and a 30 microm diamond followed by a tungsten carbide finishing bur (n = 25). Final polishing of each of the three finishing groups was accomplished with SuperBuff, Diafix-oral, OneGloss, Astropol and HaWe Composite Polishers (n = 5, each). Surface roughness was evaluated quantitatively by laser-stylus profilometry. Average roughness (R(a)) was calculated; statistical analysis of the data was performed with two-way ANOVA and Scheffé post-hoc tests. The polished surfaces were examined qualitatively by SEM. The results showed significant effects on surface roughness from the different composites (p = 0.011) and polishing systems (p < 0.001). After polishing, the Solitaire surfaces (R(a) = 0.72 microm) were smoother than Definite (R(a) = 0.87 microm) and SureFil (R(a) = 0.89 microm) and significantly smoother than Herculite (R(a) = 0.92 microm; p = 0.011). Three of the polishing methods (SuperBuff, Diafix-oral and Astropol) achieved lower R(a)-values than Sof-Lex discs. The polishing quality of the one-step systems SuperBuff and Diafix-oral was strongly affected by the initial finishing protocol.
Surface Geometry and Chemistry of Hydrothermally Synthesized Single Crystal Thorium Dioxide
2015-03-01
Atmospheric Adsorbents ...............61 4.2.3 Heating Changes the Quantity of Charge on the ThO2 Surface ..................63 4.2.4 Humidity ...The Th peaks at 675 K during the heating phase of the 2nd sequence.. .................... 68 29. Adhesion force as a function of relative humidity ...The crystal used in this experiment was grown by hydrothermal growth techniques via spontaneous nucleation . The experiment was conducted on crystal
Czech Academy of Sciences Publication Activity Database
Šimek, Milan; Prukner, Václav; Schmidt, Jiří
2008-01-01
Roč. 53, č. 10 (2008), s. 60-60 ISSN 0003-0503. [The 61st Annual Gaseous Electronic Conference. Dallas, Texas , 13.10.2008-17.10.2008] R&D Projects: GA ČR GA202/08/1106 Institutional research plan: CEZ:AV0Z20430508 Keywords : dielectric barrier surface discharge * nitrogen * spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics
Devi, Koijam Monika; Porsezian, K.; Sarma, Amarendra K.
2018-05-01
We report Akhmediev Breather solutions in a nonlinear multilayer structure comprising of a metal sandwiched between two semi-infinite dielectric layers with subwavelength thickness. These nonlinear solutions inherit the properties of Surface plasmon polaritons and its dynamics is governed by the Nonlinear Schrodinger equation. The breather evolution is studied for specific values of nonlinear and dispersion parameters. An experimental scheme to observe these breathers is also proposed.
Preliminary Correlation Map of Geomorphic Surfaces in North-Central Frenchman Flat, Nevada Test Site
International Nuclear Information System (INIS)
Bechtel Nevada
2005-01-01
This correlation map (scale = 1:12,000) presents the results of a mapping initiative that was part of the comprehensive site characterization required to operate the Area 5 Radioactive Waste Management Site, a low-level radioactive waste disposal facility located in northern Frenchman Flat at the Nevada Test Site. Eight primary map units are recognized for Quaternary surfaces: remnants of six alluvial fan or terrace surfaces, one unit that includes colluvial aprons associated with hill slopes, and one unit for anthropogenically disturbed surfaces. This surficial geology map provides fundamental data on natural processes for reconstruction of the Quaternary history of northern Frenchman Flat, which in turn will aid in the understanding of the natural processes that act to develop the landscape, and the time-frames involved in landscape development. The mapping was conducted using color and color-infrared aerial photographs and field verification of map unit composition and boundaries. Criteria for defining the map unit composition of geomorphic surface units are based on relative geomorphic position, landform morphology, and degree of preservation of surface morphology. The bedrock units identified on this map were derived from previous published mapping efforts and are included for completeness
Comparison of Flow Characteristics of Different Sphere Geometries Under the Free Surface Effect
Directory of Open Access Journals (Sweden)
Sahin B.
2013-04-01
Full Text Available Comparison of the experimental results of turbulent flow structures between a smooth sphere and a sphere with a vent hole, roughened, and o-ring is presented in the presence of a free-surface. Dye visualization and particle image velocimetry (PIV techniques were performed to examine effects of passive control methods on the sphere wake for Reynolds number Re = 5000 based on the sphere diameter with a 42.5mm in an open water channel. Instantaneous and time-averaged flow patterns in the wake region of the sphere were examined from point of flow physics for the different sphere locations in the range of 0≤h/D≤2.0 where h was the space between the top point of the sphere and the free surface. The ratio of ventilation hole to sphere diameter was 0.15, o-ring was located at 55° with a 2 mm from front stagnation point of the sphere and roughened surface was formed by means of totally 410 circular holes with a 3 mm diameter and around 2 mm depth in an equilateral triangle arrangement. The flow characteristics of instantaneous velocity vectors, vorticity contours, time-averaged streamline patterns, Reynolds stress correlations and streamwise and cross-stream velocity fluctuations for both the smooth and passively controlled sphere were interpreted.
Directory of Open Access Journals (Sweden)
С. А. Игнатьев
2016-08-01
Full Text Available The paper addresses an issue of creating an environment favorable for the life in megacities by planting vegetation on the rooftops. It also provides information about rooftop greening practices adopted in other countries. The issues of ‘green roof’ building in climatic conditions of Saint Petersburg and roof vegetation impact on the urban ecosystem are examined. Vegetation composition quality- and quantity-wise has been proposed for the roof under research and a 3D model of this roof reflecting its geometric properties has been developed. A structure of roof covering and substrate qualitative composition is presented. An effect of rooftop geometry on the substrate temperature is explored. The annual substrate temperature and moisture content in different parts of the roof have been analyzed. Results of thermal imaging monitoring and insolation modelling for different parts of green roof surface are presented.
Camacho, A. G.; Fernández, J.; Cannavò, F.
2018-02-01
We present a software package to carry out inversions of surface deformation data (any combination of InSAR, GPS, and terrestrial data, e.g., EDM, levelling) as produced by 3D free-geometry extended bodies with anomalous pressure changes. The anomalous structures are described as an aggregation of elementary cells (whose effects are estimated as coming from point sources) in an elastic half space. The linear inverse problem (considering some simple regularization conditions) is solved by means of an exploratory approach. This software represents the open implementation of a previously published methodology (Camacho et al., 2011). It can be freely used with large data sets (e.g. InSAR data sets) or with data coming from small control networks (e.g. GPS monitoring data), mainly in volcanic areas, to estimate the expected pressure bodies representing magmatic intrusions. Here, the software is applied to some real test cases.
Lepping, R. P.; Chao, J. K.
1976-01-01
An estimated shape is presented for the surface of the flare-associated interplanetary shock of February 15-16, 1967, as seen in the ecliptic-plane cross section. The estimate is based on observations by Explorer 33 and Pioneers 6 and 7. The estimated shock normal at the Explorer 33 position is obtained by a least-squares shock parameter-fitting procedure for that satellite's data; the shock normal at the Pioneer 7 position is found by using the magnetic coplanarity theorem and magnetic-field data. The average shock speed from the sun to each spacecraft is determined along with the local speed at Explorer 33 and the relations between these speeds and the position of the initiating solar flare. The Explorer 33 shock normal is found to be severely inclined and not typical of interplanetary shocks. It is shown that the curvature of the shock surface in the ecliptic plane near the earth-Pioneer 7 region is consistent with a radius of not more than 0.4 AU.
Self-organizing adaptive map: autonomous learning of curves and surfaces from point samples.
Piastra, Marco
2013-05-01
Competitive Hebbian Learning (CHL) (Martinetz, 1993) is a simple and elegant method for estimating the topology of a manifold from point samples. The method has been adopted in a number of self-organizing networks described in the literature and has given rise to related studies in the fields of geometry and computational topology. Recent results from these fields have shown that a faithful reconstruction can be obtained using the CHL method only for curves and surfaces. Within these limitations, these findings constitute a basis for defining a CHL-based, growing self-organizing network that produces a faithful reconstruction of an input manifold. The SOAM (Self-Organizing Adaptive Map) algorithm adapts its local structure autonomously in such a way that it can match the features of the manifold being learned. The adaptation process is driven by the defects arising when the network structure is inadequate, which cause a growth in the density of units. Regions of the network undergo a phase transition and change their behavior whenever a simple, local condition of topological regularity is met. The phase transition is eventually completed across the entire structure and the adaptation process terminates. In specific conditions, the structure thus obtained is homeomorphic to the input manifold. During the adaptation process, the network also has the capability to focus on the acquisition of input point samples in critical regions, with a substantial increase in efficiency. The behavior of the network has been assessed experimentally with typical data sets for surface reconstruction, including suboptimal conditions, e.g. with undersampling and noise. Copyright © 2012 Elsevier Ltd. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Du, Jiangtao; Sharples, Steve [School of Architecture, University of Sheffield, Crookesmoor Building, Conduit Road, Sheffield S10 1FL (United Kingdom)
2010-07-15
This study investigated the impacts of different diffuse reflectance distributions and well geometries on vertical daylight factors and vertical internally reflected components in atria. Two forms of reflectance distribution patterns of wall surface were examined: horizontal and vertical reflectance band variation. The square atrium models studied have a broader WI range of 0.25-2.0, which represent shallow, medium and high atria. Radiance, a powerful package based on backward ray tracing technique, was used for the simulations of vertical daylight levels. The results show that different reflectance distributions of square atrium walls do have an impact on the vertical daylight factors and vertical internally reflected components under overcast sky condition. The impact relates to the orientation of the band with different reflectance distributions on the wall. Compared with the vertical band surface, the horizontal band surface has a much more complicated effect. The horizontal distributions of the reflectances significantly affects the vertical daylight levels at the locations more than 30% atrium height on the wall. For an atrium with a height more than 1/2 the width, the effect tends to increase with the increasing well index. The vertical distributions of the reflectance, nevertheless, do not substantially take effect on the vertical daylight levels in atria except for some special reflectance distribution patterns. (author)
International Nuclear Information System (INIS)
Siewert, E; Schein, J; Forster, G
2013-01-01
The metal transfer is a fundamental process in gas metal arc welding, which substantially determines the shape of the weld seam and strongly influences arc formation and stability. In this investigation the material transfer from the wire electrode (anode) to the workpiece (cathode) is analysed experimentally with high accuracy using various innovative diagnostic techniques for a pulsed gas metal arc welding (PGMAW) process. A high-speed two-colour pyrometer, a calorimeter, thermocouples, a stereo optical setup and a droplet oscillation technique are used to analyse a precisely defined PGMAW process. Thus, results obtained are verified by different measurement techniques and enable a comprehensive description of the material transfer procedure. The surface temperature of both electrodes as well as the droplet temperature, enthalpy and surface tension were determined. Furthermore, the geometry of the arc, wire, droplets and weld pool were extracted in three dimensions in order to describe the interaction between the material transfer and the formation of the weld seam. The experiments are performed using argon as shielding gas and pure iron as filler and base material to reduce complex chemical processes. It turned out that the wire feed rate has the biggest influence on droplet temperature and detachment. A correlation between weld pool formation and weld pool surface temperature gradient was observed, which is mainly a function of welding speed and wire feed rate. The experimental results obtained provide a detailed data pool for use in modelling. (paper)
International Nuclear Information System (INIS)
Orantin, N.
2007-09-01
The 2-matrix model has been introduced to study Ising model on random surfaces. Since then, the link between matrix models and arrangement of discrete surfaces has strongly tightened. This manuscript aims to investigate these deep links and extend them beyond the matrix models, following my work's evolution. First, I take care to define properly the hermitian 2 matrix model which gives rise to generating functions of discrete surfaces equipped with a spin structure. Then, I show how to compute all the terms in the topological expansion of any observable by using algebraic geometry tools. They are obtained as differential forms on an algebraic curve associated to the model: the spectral curve. In a second part, I show how to define such differentials on any algebraic curve even if it does not come from a matrix model. I then study their numerous symmetry properties under deformations of the algebraic curve. In particular, I show that these objects coincide with the topological expansion of the observable of a matrix model if the algebraic curve is the spectral curve of this model. Finally, I show that the fine tuning of the parameters ensures that these objects can be promoted to modular invariants and satisfy the holomorphic anomaly equation of the Kodaira-Spencer theory. This gives a new hint that the Dijkgraaf-Vafa conjecture is correct. (author)
Sensing (un)binding events via surface plasmons: effects of resonator geometry
Antosiewicz, Tomasz J.; Claudio, Virginia; Käll, Mikael
2016-04-01
The resonance conditions of localized surface plasmon resonances (LSPRs) can be perturbed in any number ways making plasmon nanoresonators viable tools in detection of e.g. phase changes, pH, gasses, and single molecules. Precise measurement via LSPR of molecular concentrations hinge on the ability to confidently count the number of molecules attached to a metal resonator and ideally to track binding and unbinding events in real-time. These two requirements make it necessary to rigorously quantify relations between the number of bound molecules and response of plasmonic sensors. This endeavor is hindered on the one hand by a spatially varying response of a given plasmonic nanosensor. On the other hand movement of molecules is determined by stochastic effects (Brownian motion) as well as deterministic flow, if present, in microfluidic channels. The combination of molecular dynamics and the electromagnetic response of the LSPR yield an uncertainty which is little understood and whose effect is often disregarded in quantitative sensing experiments. Using a combination of electromagnetic finite-difference time-domain (FDTD) calculations of the plasmon resonance peak shift of various metal nanosensors (disk, cone, rod, dimer) and stochastic diffusion-reaction simulations of biomolecular interactions on a sensor surface we clarify the interplay between position dependent binding probability and inhomogeneous sensitivity distribution. We show, how the statistical characteristics of the total signal upon molecular binding are determined. The proposed methodology is, in general, applicable to any sensor and any transduction mechanism, although the specifics of implementation will vary depending on circumstances. In this work we focus on elucidating how the interplay between electromagnetic and stochastic effects impacts the feasibility of employing particular shapes of plasmonic sensors for real-time monitoring of individual binding reactions or sensing low concentrations
Pure Surface Texture Mapping Technology and it's Application for Mirror Image
Directory of Open Access Journals (Sweden)
Wei Feng Wang
2013-02-01
Full Text Available Based on the study of pure surface texture mapping technology, pure texture surface rendering method is proposed. The method is combined pure surface texture rendering and view mirror, real-time rendering has an index of refraction, reflection, and the flow of water ripple effect. Through the experimental verification of the validity of the algorithm.
Calibration and Industrial Application of Instrument for Surface Mapping based on AFM
DEFF Research Database (Denmark)
Hansen, Hans Nørgaard; Kofod, Niels; De Chiffre, Leonardo
2002-01-01
The paper describes the calibration and application of an integrated system for topographic characterisation of fine surfaces on large workpieces. The system, consisting of an atomic force microscope mounted on a coordinate measuring machine, was especially designed for surface mapping, i.e., mea...... consisting of a steel sphere with a polished surface having 3 nm roughness....
Geomorphic Surface Maps of Northern Frenchman Flat, Nevada Test Site, Southern Nevada
International Nuclear Information System (INIS)
Bechtel Nevada
2005-01-01
Large-scale (1:6000) surficial geology maps of northern Frenchman Flat were developed in 1995 as part of comprehensive site characterization required to operate a low-level radioactive waste disposal facility in that area. Seven surficial geology maps provide fundamental data on natural processes and are the platform needed to reconstruct the Quaternary history of northern Frenchman Flat. Reconstruction of the Quaternary history provides an understanding of the natural processes that act to develop the landscape, and the time-frames involved in landscape development. The mapping was conducted using color and color-infrared aerial photographs and field verification of map unit composition and boundaries. Criteria for defining the map unit composition of geomorphic surface units are based on relative geomorphic position, landform morphology, and degree of preservation of surface morphology. Seven geomorphic surfaces (Units 1 through 7) are recognized, spanning from the early Quaternary to present time
Surface Geophysical Measurements for Locating and Mapping Ice-Wedges
DEFF Research Database (Denmark)
Ingeman-Nielsen, Thomas; Tomaskovicova, Sonia; Larsen, S.H.
2012-01-01
to test the applicability of DC electrical resistivity tomography (ERT) and Ground Penetrating Radar (GPR) to identifying and mapping ice-wedge occurrences. The site is located in Central West Greenland, and the ice-wedges are found in a permafrozen peat soil with an active layer of about 30 cm. ERT...
Sullivan, F.; Palace, M. W.; Ducey, M. J.; David, O.; Cook, B. D.; Lepine, L. C.
2014-12-01
Harvard Forest in Petersham, MA, USA is the location of one of the temperate forest plots established by the Center for Tropical Forest Science (CTFS) as a joint effort with Harvard Forest and the Smithsonian Institute's Forest Global Earth Observatory (ForestGEO) to characterize ecosystem processes and forest dynamics. Census of a 35 ha plot on Prospect Hill was completed during the winter of 2014 by researchers at Harvard Forest. Census data were collected according to CTFS protocol; measured variables included species, stem diameter, and relative X-Y locations. Airborne lidar data were collected over the censused plot using the high spatial resolution Goddard LiDAR, Hyperspectral, and Thermal sensor package (G-LiHT) during June 2012. As part of a separate study, 39 variable radius plots (VRPs) were randomly located and sampled within and throughout the Prospect Hill CTFS/ForestGEO plot during September and October 2013. On VRPs, biometric properties of trees were sampled, including species, stem diameter, total height, crown base height, crown radii, and relative location to plot centers using a 20 Basal Area Factor prism. In addition, a terrestrial-based lidar scanner was used to collect one lidar scan at plot center for 38 of the 39 VRPs. Leveraging allometric equations of crown geometry and tree height developed from 374 trees and 16 different species sampled on 39 VRPs, a 3-dimensional stem map will be created using the Harvard Forest ForestGEO Prospect Hill census. Vertical and horizontal structure of 3d field-based stem maps will be compared to terrestrial and airborne lidar scan data. Furthermore, to assess the quality of allometric equations, a 2d canopy height raster of the field-based stem map will be compared to a G-LiHT derived canopy height model for the 35 ha census plot. Our automated crown delineation methods will be applied to the 2d representation of the census stem map and the G-LiHT canopy height model. For future work related to this study
Pre-LBA CABARE Mapped Land Surface and Vegetation Characteristics, Rondonia, Brazil
National Aeronautics and Space Administration — Surface parameter digital maps of vegetation, soil, and topography were obtained for Rondonia, Brazil, covering the 5x5 degree region bounded by 13-8 degrees S and...
Pre-LBA CABARE Mapped Land Surface and Vegetation Characteristics, Rondonia, Brazil
National Aeronautics and Space Administration — ABSTRACT: Surface parameter digital maps of vegetation, soil, and topography were obtained for Rondonia, Brazil, covering the 5x5 degree region bounded by 13-8...
International Nuclear Information System (INIS)
Tonooka, I.; Kubota, I.; Watanabe, Y.; Tsuiki, K.; Yasui, S.
1983-01-01
To estimate the location and size of myocardial infarction (MI), an isointegral mapping technique was adopted from among various body surface electrocardiographic mapping techniques. QRS isointegral and departure maps were made in 35 patients with MI. These patients were separated into 3 groups, based on the location of MI: anterior, inferior, and anterior plus inferior. The severity and location of MI were estimated by thallium-201 myocardial perfusion imaging and the degree of scintigraphic defect was represented by a defect score. The extent of MI was expected to be reflected on the QRS isointegral maps as a distribution of negative QRS complex time-integral values. However, the extent and the location of MI were hardly detectable by the original maps. A departure mapping technique was then devised to observe the distribution of departure index on the body surface. Particular attention was given to the area where the departure index was less than -2, and this area was expected to reflect the location and size of specific abnormality of isointegral map due to MI. There were strong correlations between departure area and defect score in the anterior and inferior MI cases (r . 0.88 and r . 0.79, respectively). However, patients with anterior MI plus inferior MI showed no such correlation. Q-wave mapping was compared with QRS isointegral mapping, and QRS isointegral mapping was found to be more accurate in the estimation of the location and size of MI than Q wave mapping. Thus, QRS isointegral mapping, especially departure mapping, is more useful and convenient for detecting the location and size of MI than methods such as isopotential and Q wave mapping
Ray-map migration of transmitted surface waves
Li, Jing; Schuster, Gerard T.
2016-01-01
Near-surface normal faults can sometimes separate two distinct zones of velocity heterogeneity, where the medium on one side of the fault has a faster velocity than on the other side. Therefore, the slope of surface-wave arrivals in a common
Surface kinetic temperature mapping using satellite spectral data in ...
African Journals Online (AJOL)
The result revealed that despite the limited topographic differences of the rift lakes and their proximity, the surface kinetic temperature difference is high, mainly due to groundwater and surface water fluxes. From thermal signature analysis two hot springs below the lake bed of Ziway were discovered. The various hot springs ...
Wang, Yalin; Zhang, Jie; Gutman, Boris; Chan, Tony F; Becker, James T; Aizenstein, Howard J; Lopez, Oscar L; Tamburo, Robert J; Toga, Arthur W; Thompson, Paul M
2010-02-01
Here we developed a new method, called multivariate tensor-based surface morphometry (TBM), and applied it to study lateral ventricular surface differences associated with HIV/AIDS. Using concepts from differential geometry and the theory of differential forms, we created mathematical structures known as holomorphic one-forms, to obtain an efficient and accurate conformal parameterization of the lateral ventricular surfaces in the brain. The new meshing approach also provides a natural way to register anatomical surfaces across subjects, and improves on prior methods as it handles surfaces that branch and join at complex 3D junctions. To analyze anatomical differences, we computed new statistics from the Riemannian surface metrics-these retain multivariate information on local surface geometry. We applied this framework to analyze lateral ventricular surface morphometry in 3D MRI data from 11 subjects with HIV/AIDS and 8 healthy controls. Our method detected a 3D profile of surface abnormalities even in this small sample. Multivariate statistics on the local tensors gave better effect sizes for detecting group differences, relative to other TBM-based methods including analysis of the Jacobian determinant, the largest and smallest eigenvalues of the surface metric, and the pair of eigenvalues of the Jacobian matrix. The resulting analysis pipeline may improve the power of surface-based morphometry studies of the brain. Copyright (c) 2009 Elsevier Inc. All rights reserved.
International Nuclear Information System (INIS)
Moreau, Eric; Sosa, Roberto; Artana, Guillermo
2008-01-01
Active flow control is a rapidly developing topic because the associated industrial applications are of immense importance, particularly for aeronautics. Among all the flow control methods, such as the use of mechanical flaps or wall jets, plasma-based devices are very promising devices. The main advantages of such systems are their robustness, their simplicity, their low-power consumption and that they allow a real-time control at high frequency. This paper deals with an experimental study about the electric wind produced by a surface discharge based on a three-electrode geometry. This new device is composed of a typical two-electrode surface barrier discharge excited by an AC high voltage, plus a third electrode at which a DC high voltage is applied in order to extend the discharge region and to accelerate the ion drift velocity. In the first part the electrical current of these different surface discharges is presented and discussed. This shows that the current behaviour depends on the DC component polarity. The second part is dedicated to analysing the electric wind characteristics through Schlieren visualizations and to measuring its time-averaged velocity with a Pitot tube sensor. The results show that an excitation of the electrodes with an AC voltage plus a positive DC component can significantly modify the topology of the electric wind produced by a single DBD. In practice, this DC component allows us to increase the value of the maximum induced velocity (up to +150% at a few centimetres downstream of the discharge) and the plasma extension, to enhance the depression occurring above the discharge region and to increase the discharge-induced mass flow rate (up to +100%), without increasing the electrical power consumption
An atlas of the smaller maps in orientable and nonorientable surfaces
Jackson, David
2000-01-01
Maps are beguilingly simple structures with deep and ubiquitous properties. They arise in an essential way in many areas of mathematics and mathematical physics, but require considerable time and computational effort to generate. Few collected drawings are available for reference, and little has been written, in book form, about their enumerative aspects. An Atlas of the Smaller Maps in Orientable and Nonorientable Surfaces is the first book to provide complete collections of maps along with their vertex and face partitions, number of rootings, and an index number for cross referencing. It provides an explanation of axiomatization and encoding, and serves as an introduction to maps as a combinatorial structure. The Atlas lists the maps first by genus and number of edges, and gives the embeddings of all graphs with at most five edges in orientable surfaces, thus presenting the genus distribution for each graph. Exemplifying the use of the Atlas, the authors explore two substantial conjectures with origins in ...
Functional and structural mapping of human cerebral cortex: solutions are in the surfaces
Van Essen, D. C.; Drury, H. A.; Joshi, S.; Miller, M. I.
1998-01-01
The human cerebral cortex is notorious for the depth and irregularity of its convolutions and for its variability from one individual to the next. These complexities of cortical geography have been a chronic impediment to studies of functional specialization in the cortex. In this report, we discuss ways to compensate for the convolutions by using a combination of strategies whose common denominator involves explicit reconstructions of the cortical surface. Surface-based visualization involves reconstructing cortical surfaces and displaying them, along with associated experimental data, in various complementary formats (including three-dimensional native configurations, two-dimensional slices, extensively smoothed surfaces, ellipsoidal representations, and cortical flat maps). Generating these representations for the cortex of the Visible Man leads to a surface-based atlas that has important advantages over conventional stereotaxic atlases as a substrate for displaying and analyzing large amounts of experimental data. We illustrate this by showing the relationship between functionally specialized regions and topographically organized areas in human visual cortex. Surface-based warping allows data to be mapped from individual hemispheres to a surface-based atlas while respecting surface topology, improving registration of identifiable landmarks, and minimizing unwanted distortions. Surface-based warping also can aid in comparisons between species, which we illustrate by warping a macaque flat map to match the shape of a human flat map. Collectively, these approaches will allow more refined analyses of commonalities as well as individual differences in the functional organization of primate cerebral cortex.
Large area optical mapping of surface contact angle.
Dutra, Guilherme; Canning, John; Padden, Whayne; Martelli, Cicero; Dligatch, Svetlana
2017-09-04
Top-down contact angle measurements have been validated and confirmed to be as good if not more reliable than side-based measurements. A range of samples, including industrially relevant materials for roofing and printing, has been compared. Using the top-down approach, mapping in both 1-D and 2-D has been demonstrated. The method was applied to study the change in contact angle as a function of change in silver (Ag) nanoparticle size controlled by thermal evaporation. Large area mapping reveals good uniformity for commercial Aspen paper coated with black laser printer ink. A demonstration of the forensic and chemical analysis potential in 2-D is shown by uncovering the hidden CsF initials made with mineral oil on the coated Aspen paper. The method promises to revolutionize nanoscale characterization and industrial monitoring as well as chemical analyses by allowing rapid contact angle measurements over large areas or large numbers of samples in ways and times that have not been possible before.
Measurement system for special surface mapping using miniature displacement sensors
Directory of Open Access Journals (Sweden)
Zowade Martyna
2018-01-01
Full Text Available The aim of the work was to design a special system for measurements of elements with repetitive geometry or assemblies with repeating components, set in a linear patterns. The main focus was based on developing a computer program for signal analysis from variable number of miniature displacement sensors. It was set that the response for displacement of measuring tip from each sensor was a 0-5 V voltage signal with possibility of using different type of sensors. Requirements were determined based on projected measurement method. A special design of sensor was made for testing the computer program. If the characteristics of the sensor is known, it is possible to compute the type A evaluation of uncertainty. The results are presented in XY chart on computer screen. The program allows the user to choose any number of the sensors and determine the distance between them. Also, the possibility of calibration of sensors’ set was provided. The test were conducted on a prototype handle for sensors, made on a 3D printer.
Eldridge, Jeffrey I.; Shyam, Vikram; Wroblewski, Adam C.; Zhu, Dongming; Cuy, Michael D.; Wolfe, Douglas E.
2016-01-01
It has been recently shown that the high luminescence intensity from a Cr-doped GdAlO3 (Cr:GdAlO3) thermographic phosphor enables non-rastered full-field temperature mapping of thermal barrier coating (TBC) surfaces to temperatures above 1000C. In this presentation, temperature mapping by Cr:GdAlO3 based phosphor thermometry of air film-cooled TBC-coated surfaces is demonstrated for both scaled-up cooling hole geometries as well as for actual components in a burner rig test environment. The effects of thermal background radiation and flame chemiluminescence on the measurements are investigated, and advantages of this method over infrared thermography as well as the limitations of this method for studying air film cooling are discussed.
Mapping physicochemical surface modifications of flame-treated polypropylene
Directory of Open Access Journals (Sweden)
S. Farris
2014-04-01
Full Text Available The aim of this work was to investigate how the surface morphology of polypropylene (PP is influenced by the surface activation mediated by a flame obtained using a mixture of air and propane under fuel-lean (equivalence ratio φ = 0.98 conditions. Morphological changes observed on flamed samples with smooth (S, medium (M, and high (H degree of surface roughness were attributed to the combined effect of a chemical mechanism (agglomeration and ordering of partially oxidized intermediate-molecular-weight material with a physical mechanism (flattening of the original roughness by the flame’s high temperature. After two treatments, the different behavior of the samples in terms of wettability was totally reset, which made an impressive surface energy of ~43 mJ•m–2 possible, which is typical of more hydrophilic polymers (e.g., polyethylene terephthalate – PET. In particular, the polar component was increased from 1.21, 0.08, and 0.32 mJ•m–2 (untreated samples to 10.95, 11.20, and 11.17 mJ•m–2 for the flamed samples S, M, and H, respectively, an increase attributed to the insertion of polar functional groups (hydroxyl and carbonyl on the C–C backbone, as demonstrated by the X-ray photoelectron spectroscopy results.
Face recognition based on depth maps and surface curvature
Gordon, Gaile G.
1991-09-01
This paper explores the representation of the human face by features based on the curvature of the face surface. Curature captures many features necessary to accurately describe the face, such as the shape of the forehead, jawline, and cheeks, which are not easily detected from standard intensity images. Moreover, the value of curvature at a point on the surface is also viewpoint invariant. Until recently range data of high enough resolution and accuracy to perform useful curvature calculations on the scale of the human face had been unavailable. Although several researchers have worked on the problem of interpreting range data from curved (although usually highly geometrically structured) surfaces, the main approaches have centered on segmentation by signs of mean and Gaussian curvature which have not proved sufficient in themselves for the case of the human face. This paper details the calculation of principal curvature for a particular data set, the calculation of general surface descriptors based on curvature, and the calculation of face specific descriptors based both on curvature features and a priori knowledge about the structure of the face. These face specific descriptors can be incorporated into many different recognition strategies. A system that implements one such strategy, depth template comparison, giving recognition rates between 80% and 90% is described.
Titan's Surface Temperatures Maps from Cassini - CIRS Observations
Cottini, Valeria; Nixon, C. A.; Jennings, D. E.; Anderson, C. M.; Samuelson, R. E.; Irwin, P. G. J.; Flasar, F. M.
2009-09-01
The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 μm (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the instrument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature profile by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). In future, application of our methodology over wide areas should greatly increase the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp. 1136-1150, 2008. Rodgers, C. D.: "Inverse Methods For Atmospheric Sounding: Theory and Practice". World Scientific, Singapore, 2000. Jennings, D.E., et al.: "Titan's Surface Brightness Temperatures." Ap. J. L., Vol. 691, pp. L103-L
Bhunia, Snehasis; Forster, Stefan; Vyas, Nidhi; Schmitt, Hans-Christian; Ojha, Animesh K
2015-12-05
Fourier transform Raman (FT-Raman) spectra of neat pyridine (Py) and surface enhanced Raman scattering (SERS) spectra of Py with silver nanoparticles (AgNPs) solution at different molar concentrations (X=1.5M, 1.0M, 0.50 M, 0.25 M, and 0.125 M) were recorded using 1064 nm excitation wavelength. The intensity of Raman bands at ∼1003 (ν11) and ∼1035 (ν21) cm(-1) of Py is enhanced in the SERS spectra. Two new Raman bands were observed at ∼1009 (ν12) and ∼1038 (ν22) cm(-1) in the SERS spectra. These bands correspond to the ring breathing vibrations of Py molecules adsorbed at the AgNPs surface. The value of intensity ratios (I12/I11) and (I21/I22) is increased with dilution and attains a maximum value at X=0.5M and upon further dilution (0.25 and 0.125 M) it drops gradually. The theoretically calculated Raman spectra were found to be in good agreement with experimentally observed Raman spectra. Both, experimental and theoretical investigations have confirmed that the Py interacts with AgNPs via the end-on geometry. Copyright © 2015 Elsevier B.V. All rights reserved.
Arithmetic noncommutative geometry
Marcolli, Matilde
2005-01-01
Arithmetic noncommutative geometry denotes the use of ideas and tools from the field of noncommutative geometry, to address questions and reinterpret in a new perspective results and constructions from number theory and arithmetic algebraic geometry. This general philosophy is applied to the geometry and arithmetic of modular curves and to the fibers at archimedean places of arithmetic surfaces and varieties. The main reason why noncommutative geometry can be expected to say something about topics of arithmetic interest lies in the fact that it provides the right framework in which the tools of geometry continue to make sense on spaces that are very singular and apparently very far from the world of algebraic varieties. This provides a way of refining the boundary structure of certain classes of spaces that arise in the context of arithmetic geometry, such as moduli spaces (of which modular curves are the simplest case) or arithmetic varieties (completed by suitable "fibers at infinity"), by adding boundaries...
DEFF Research Database (Denmark)
Ade, P. A. R.; Aghanim, N.; Alves, M. I. R.
2016-01-01
of the filaments and therefore to provide insight into the structure of their magnetic field (B). We present the polarization maps of three nearby (several parsecs long) star-forming filaments of moderate column density (N-H about 1022 cm-2): Musca, B211, and L1506. These three filaments are detected above...... angles in the three filaments (ψfil) are coherent along their lengths and not the same as in their backgrounds (ψbg). The differences between ψfil and ψbg are 12 degrees and 54 degrees for Musca and L1506, respectively, and only 6 degrees in the case of B211. These differences for Musca and L1506...... (by, e. g., radiative torques) and the structure of the B-field in causing variations in p, but we argue that the decrease in p from the backgrounds to the filaments results in part from depolarization associated with the 3D structure of the B-field: both its orientation in the POS and with respect...
On the Gauss Map of Surfaces of Revolution with Lightlike Axis in Minkowski 3-Space
Directory of Open Access Journals (Sweden)
Minghao Jin
2013-01-01
Full Text Available By studying the Gauss map G and Laplace operator Δh of the second fundamental form h, we will classify surfaces of revolution with a lightlike axis in 3-dimensional Minkowski space and also obtain the surface of Enneper of the 2nd kind, the surface of Enneper of the 3rd kind, the de Sitter pseudosphere, and the hyperbolic pseudosphere that satisfy condition ΔhG=ΛG, Λ being a 3×3 real matrix.
Developing Coastal Surface Roughness Maps Using ASTER and QuickBird Data Sources
Spruce, Joe; Berglund, Judith; Davis, Bruce
2006-01-01
This viewgraph presentation regards one element of a larger project on the integration of NASA science models and data into the Hazards U.S. Multi-Hazard (HAZUS-MH) Hurricane module for hurricane damage and loss risk assessment. HAZUS-MH is a decision support tool being developed by the National Institute of Building Sciences for the Federal Emergency Management Agency (FEMA). It includes the Hurricane Module, which employs surface roughness maps made from National Land Cover Data (NLCD) maps to estimate coastal hurricane wind damage and loss. NLCD maps are produced and distributed by the U.S. Geological Survey. This presentation discusses an effort to improve upon current HAZUS surface roughness maps by employing ASTER multispectral classifications with QuickBird "ground reference" imagery.
Re-discovering surface mass spectrometry: chemical mapping from micro to macro
Energy Technology Data Exchange (ETDEWEB)
Lloyd, K.G.; O' Keefe, D.P
2004-06-15
New developments in electronics, devices, micro-encapsulation, and other areas demand the ability to acquire molecularly-specific information from smaller and smaller features. ToF-SIMS provides molecularly-specific mass spectral data, but sufficient high-mass signal has historically been difficult to obtain from organic/polymeric surfaces in the point-mapping mode of operation. Use of chemometric data reduction methods and the development of heavier primary ion sources enhance and extend the chemical information in the mapping data. Large-area chemical mapping via sample stage rastering has also opened up new applications. This capability allows single-experiment mapping of large or multiple features, provides information on surface uniformity over end-use-relevant areas, and offers potential for combinatorial and other screening applications. Examples of these applications are presented.
Mapping visual cortex in monkeys and humans using surface-based atlases
Van Essen, D. C.; Lewis, J. W.; Drury, H. A.; Hadjikhani, N.; Tootell, R. B.; Bakircioglu, M.; Miller, M. I.
2001-01-01
We have used surface-based atlases of the cerebral cortex to analyze the functional organization of visual cortex in humans and macaque monkeys. The macaque atlas contains multiple partitioning schemes for visual cortex, including a probabilistic atlas of visual areas derived from a recent architectonic study, plus summary schemes that reflect a combination of physiological and anatomical evidence. The human atlas includes a probabilistic map of eight topographically organized visual areas recently mapped using functional MRI. To facilitate comparisons between species, we used surface-based warping to bring functional and geographic landmarks on the macaque map into register with corresponding landmarks on the human map. The results suggest that extrastriate visual cortex outside the known topographically organized areas is dramatically expanded in human compared to macaque cortex, particularly in the parietal lobe.
International Nuclear Information System (INIS)
Gervais, J.L.
1993-01-01
By analyzing the extrinsic geometry of two dimensional surfaces chirally embedded in C P n (the C P n W-surface), we give exact treatments in various aspects of the classical W-geometry in the conformal gauge: First, the basis of tangent and normal vectors are defined at regular points of the surface, such that their infinitesimal displacements are given by connections which coincide with the vector potentials of the (conformal) A n -Toda Lax pair. Since the latter is known to be intrinsically related with the W symmetries, this gives the geometrical meaning of the A n W-Algebra. Second, W-surfaces are put in one-to-one correspondence with solutions of the conformally-reduced WZNW model, which is such that the Toda fields give the Cartan part in the Gauss decomposition of its solutions. Third, the additional variables of the Toda hierarchy are used as coordinates of C P n . This allows us to show that W-transformations may be extended as particular diffeomorphisms of this target-space. Higher-dimensional generalizations of the WZNW equations are derived and related with the Zakharov-Shabat equations of the Toda hierarchy. Fourth, singular points are studied from a global viewpoint, using our earlier observation that W-surfaces may be regarded as instantons. The global indices of the W-geometry, which are written in terms of the Toda fields, are shown to be the instanton numbers for associated mappings of W-surfaces into the Grassmannians. The relation with the singularities of W-surface is derived by combining the Toda equations with the Gauss-Bonnet theorem. (orig.)
Mapping Hfq-RNA interaction surfaces using tryptophan fluorescence quenching
Robinson, Kirsten E.; Orans, Jillian; Kovach, Alexander R.; Link, Todd M.; Brennan, Richard G.
2014-01-01
Hfq is a posttranscriptional riboregulator and RNA chaperone that binds small RNAs and target mRNAs to effect their annealing and message-specific regulation in response to environmental stressors. Structures of Hfq-RNA complexes indicate that U-rich sequences prefer the proximal face and A-rich sequences the distal face; however, the Hfq-binding sites of most RNAs are unknown. Here, we present an Hfq-RNA mapping approach that uses single tryptophan-substituted Hfq proteins, all of which retain the wild-type Hfq structure, and tryptophan fluorescence quenching (TFQ) by proximal RNA binding. TFQ properly identified the respective distal and proximal binding of A15 and U6 RNA to Gram-negative Escherichia coli (Ec) Hfq and the distal face binding of (AA)3A, (AU)3A and (AC)3A to Gram-positive Staphylococcus aureus (Sa) Hfq. The inability of (GU)3G to bind the distal face of Sa Hfq reveals the (R-L)n binding motif is a more restrictive (A-L)n binding motif. Remarkably Hfq from Gram-positive Listeria monocytogenes (Lm) binds (GU)3G on its proximal face. TFQ experiments also revealed the Ec Hfq (A-R-N)n distal face-binding motif should be redefined as an (A-A-N)n binding motif. TFQ data also demonstrated that the 5′-untranslated region of hfq mRNA binds both the proximal and distal faces of Ec Hfq and the unstructured C-terminus. PMID:24288369
A chord diagrammatic presentation of the mapping class group of a once bordered surface
DEFF Research Database (Denmark)
Bene, Alex
2010-01-01
of Teichmüller space with a discrete set objects. In particular, it leads to an infinite, but combinatorially simple, presentation of the mapping class group of an orientable surface. In this note, we give a presentation of a full mapping class group equivariant subgroupoid of the Ptolemy groupoid......The Ptolemy groupoid is a combinatorial groupoid generated by elementary moves on marked trivalent fatgraphs with three types of relations. Through the fatgraph decomposition of Teichmüller space, the Ptolemy groupoid is a mapping class group equivariant subgroupoid of the fundamental path groupoid...
A Chord Diagrammatic Presentation of the Mapping Class Group of a Once Bordered Surface
DEFF Research Database (Denmark)
Bene, Alex
groupoid of Teichm\\"uller space with a discrete set objects. In particular, it leads to an infinite, but combinatorially simple, presentation of the mapping class group of an orientable surface. In this note, we give a presentation of a full mapping class group equivariant subgroupoid of the Ptolemy......The Ptolemy groupoid is a combinatorial groupoid generated by elementary moves on marked trivalent fatgraphs with three types of relations. Through the fatgraph decomposition of Teichm\\"uller space, the Ptolemy groupoid is a mapping class group equivariant subgroupoid of the fundamental path...
Regional quantitative analysis of cortical surface maps of FDG PET images
Protas, H D; Hayashi, K M; Chin Lung, Yu; Bergsneider, M; Sung Cheng, Huang
2006-01-01
Cortical surface maps are advantageous for visualizing the 3D profile of cortical gray matter development and atrophy, and for integrating structural and functional images. In addition, cortical surface maps for PET data, when analyzed in conjunction with structural MRI data allow us to investigate, and correct for, partial volume effects. Here we compared quantitative regional PET values based on a 3D cortical surface modeling approach with values obtained directly from the 3D FDG PET images in various atlas-defined regions of interest (ROIs; temporal, parietal, frontal, and occipital lobes). FDG PET and 3D MR (SPGR) images were obtained and aligned to ICBM space for 15 normal subjects. Each image was further elastically warped in 2D parameter space of the cortical surface, to align major cortical sulci. For each point within a 15 mm distance of the cortex, the value of the PET intensity was averaged to give a cortical surface map of FDG uptake. The average PET values on the cortical surface map were calcula...
Waste-surface mapping of the Fernald K-65 silos using a structured light measurement system
International Nuclear Information System (INIS)
Burks, B.L.; DePiero, F.W.; Dinkins, M.A.; Rowe, J.C.; Selleck, C.B.; Jacoboski, D.L.
1992-10-01
A remotely operated surface-mapping measurement system was developed by the Robotics ampersand Process Systems Division at Oak Ridge National Laboratory for use in the K-65 waste-storage silos at Fernald, Ohio. The mapping system used three infrared line-generating laser diodes as illumination sources and three high-resolution, low-lux, calibrated, black-and-white, charge-coupled-device video cameras as receivers. These components were combined to form structured light source range and direction sensors with six different possible emitter-receiver pairs. A technology demonstration and predeployment tests were performed at Fernald using the empty Silo 4 into which was placed rectangular objects of known dimensions. These objects were scanned by the structured light sources to demonstrate functionality and verify that the system was giving sufficiently accurate range data in three dimensions. The structured light sources were deployed in Silos 1 and 2 to scan the waste surfaces. The resulting data were merged to create three-dimensional maps of those surfaces. A bentonite clay cap was placed over the waste surfaces and surface maps were obtained. The change in surface height before and after bentonite addition was utilized as a measure of clay cap thickness
Iversen, Birger
1992-01-01
Although it arose from purely theoretical considerations of the underlying axioms of geometry, the work of Einstein and Dirac has demonstrated that hyperbolic geometry is a fundamental aspect of modern physics
Ochiai, T.; Nacher, J. C.
2011-09-01
Recently, the application of geometry and conformal mappings to artificial materials (metamaterials) has attracted the attention in various research communities. These materials, characterized by a unique man-made structure, have unusual optical properties, which materials found in nature do not exhibit. By applying the geometry and conformal mappings theory to metamaterial science, it may be possible to realize so-called "Harry Potter cloaking device". Although such a device is still in the science fiction realm, several works have shown that by using such metamaterials it may be possible to control the direction of the electromagnetic field at will. We could then make an object hidden inside of a cloaking device. Here, we will explain how to design invisibility device using differential geometry and conformal mappings.
Mapping 2000 2010 Impervious Surface Change in India Using Global Land Survey Landsat Data
Wang, Panshi; Huang, Chengquan; Brown De Colstoun, Eric C.
2017-01-01
Understanding and monitoring the environmental impacts of global urbanization requires better urban datasets. Continuous field impervious surface change (ISC) mapping using Landsat data is an effective way to quantify spatiotemporal dynamics of urbanization. It is well acknowledged that Landsat-based estimation of impervious surface is subject to seasonal and phenological variations. The overall goal of this paper is to map 200-02010 ISC for India using Global Land Survey datasets and training data only available for 2010. To this end, a method was developed that could transfer the regression tree model developed for mapping 2010 impervious surface to 2000 using an iterative training and prediction (ITP) approach An independent validation dataset was also developed using Google Earth imagery. Based on the reference ISC from the validation dataset, the RMSE of predicted ISC was estimated to be 18.4%. At 95% confidence, the total estimated ISC for India between 2000 and 2010 is 2274.62 +/- 7.84 sq km.
Surface peptide mapping of protein I and protein III of four strains of Neisseria gonorrhoeae
International Nuclear Information System (INIS)
Judd, R.C.
1982-01-01
Whole cells and isolated outer membranes (OMs) of four strains of gonococci were surface radioiodinated with either lactoperoxidase or Iodogen (Pierce Chemical Co., Rockford, Ill.). These preparations were solubilized in sodium dodecyl sulfate and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Surface-radioiodinated protein I (PI) and PIII bands were excised from the sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels and digested with alpha-chymotrypsin, and the resultant 125 I-peptide fragments were resolved by high-voltage electrophoresis and thin-layer chromatography (i.e., surface peptide mapping). Radioemitting peptidic fragments were visualized by autoradiography. Results demonstrated that the PI molecule of each gonococcal strain studied had unique iodinatable peptides exposed on the surface of whole cells and OMs, whereas PIIIs appeared to have the same portion of the molecule exposed on the surface of bacteria or OMs, regardless of the gonococcal strain from which they were isolated. Many more radiolabeled peptides were seen in surface peptide maps of PIs from radiolabeled OMs than in those from radioiodinated whole cells, whereas different peptidic fragments were seen in the surface peptide maps of PIIIs from radiolabeled OMs than were seen in those from radiolabeled whole cells. These data suggest that PI may contribute strain-specific antigenic determinants and PIII may contribute cross-reactive determinants and that the surface exposure of PI and PIII is different in isolated OMs than in the OM of intact gonococci
Eastern Denali Fault surface trace map, eastern Alaska and Yukon, Canada
Bender, Adrian M.; Haeussler, Peter J.
2017-05-04
We map the 385-kilometer (km) long surface trace of the right-lateral, strike-slip Denali Fault between the Totschunda-Denali Fault intersection in Alaska, United States and the village of Haines Junction, Yukon, Canada. In Alaska, digital elevation models based on light detection and ranging and interferometric synthetic aperture radar data enabled our fault mapping at scales of 1:2,000 and 1:10,000, respectively. Lacking such resources in Yukon, we developed new structure-from-motion digital photogrammetry products from legacy aerial photos to map the fault surface trace at a scale of 1:10,000 east of the international border. The section of the fault that we map, referred to as the Eastern Denali Fault, did not rupture during the 2002 Denali Fault earthquake (moment magnitude 7.9). Seismologic, geodetic, and geomorphic evidence, along with a paleoseismic record of past ground-rupturing earthquakes, demonstrate Holocene and contemporary activity on the fault, however. This map of the Eastern Denali Fault surface trace complements other data sets by providing an openly accessible digital interpretation of the location, length, and continuity of the fault’s surface trace based on the accompanying digital topography dataset. Additionally, the digitized fault trace may provide geometric constraints useful for modeling earthquake scenarios and related seismic hazard.
van den Broek, P.M.
1984-01-01
The aim of this paper is to give a detailed exposition of the relation between the geometry of twistor space and the geometry of Minkowski space. The paper has a didactical purpose; no use has been made of differential geometry and cohomology.
Kulczycki, Stefan
2008-01-01
This accessible approach features two varieties of proofs: stereometric and planimetric, as well as elementary proofs that employ only the simplest properties of the plane. A short history of geometry precedes a systematic exposition of the principles of non-Euclidean geometry.Starting with fundamental assumptions, the author examines the theorems of Hjelmslev, mapping a plane into a circle, the angle of parallelism and area of a polygon, regular polygons, straight lines and planes in space, and the horosphere. Further development of the theory covers hyperbolic functions, the geometry of suff
Almansa, Julio; Salvat-Pujol, Francesc; Díaz-Londoño, Gloria; Carnicer, Artur; Lallena, Antonio M.; Salvat, Francesc
2016-02-01
The Fortran subroutine package PENGEOM provides a complete set of tools to handle quadric geometries in Monte Carlo simulations of radiation transport. The material structure where radiation propagates is assumed to consist of homogeneous bodies limited by quadric surfaces. The PENGEOM subroutines (a subset of the PENELOPE code) track particles through the material structure, independently of the details of the physics models adopted to describe the interactions. Although these subroutines are designed for detailed simulations of photon and electron transport, where all individual interactions are simulated sequentially, they can also be used in mixed (class II) schemes for simulating the transport of high-energy charged particles, where the effect of soft interactions is described by the random-hinge method. The definition of the geometry and the details of the tracking algorithm are tailored to optimize simulation speed. The use of fuzzy quadric surfaces minimizes the impact of round-off errors. The provided software includes a Java graphical user interface for editing and debugging the geometry definition file and for visualizing the material structure. Images of the structure are generated by using the tracking subroutines and, hence, they describe the geometry actually passed to the simulation code.
Vasilkov, Alexander; Qin, Wenhan; Krotkov, Nickolay; Lamsal, Lok; Spurr, Robert; Haffner, David; Joiner, Joanna; Yang, Eun-Su; Marchenko, Sergey
2017-01-01
The Ozone Monitoring Instrument (OMI) cloud and NO2 algorithms use a monthly gridded surface reflectivity climatology that does not depend upon the observation geometry. In reality, reflection of incoming direct and diffuse solar light from land or ocean surfaces is sensitive to the sun sensor geometry. This dependence is described by the bidirectional reflectance distribution function (BRDF). To account for the BRDF, we propose to use a new concept of geometry-dependent Lambertian equivalent reflectivity (GLER). Implementation within the existing OMI cloud and NO2 retrieval infrastructure requires changes only to the input surface reflectivity database. GLER is calculated using a vector radiative transfer model with high spatial resolution BRDF information from MODIS over land and the Cox Munk slope distribution over ocean with a contribution from water-leaving radiance. We compare GLER and climatological LER at 466 nm, which is used in the OMI O2-O2cloud algorithm to derive effective cloud fractions. A detailed comparison of the cloud fractions and pressures derived with climatological and GLERs is carried out. GLER and corresponding retrieved cloud products are then used as input to the OMI NO2 algorithm. We find that replacing the climatological OMI-based LERs with GLERs can increase NO2 vertical columns by up to 50 % in highly polluted areas; the differences include both BRDF effects and biases between the MODIS and OMI-based surface reflectance data sets. Only minor changes to NO2 columns (within 5 %) are found over unpolluted and overcast areas.
Adhesion mapping of chemically modified and poly(ethylene oxide)-grafted glass surfaces
Jogikalmath, G.; Stuart, J.K.; Pungor, A.; Hlady, V.
1999-01-01
Two-dimensional mapping of the adhesion pull-off forces was used to study the origin of surface heterogeneity in the grafted poly(ethylene oxide) (PEO) layer. The variance of the pull-off forces measured over the μm-sized regions after each chemical step of modifying glass surfaces was taken to be a measure of the surface chemical heterogeneity. The attachment of γ-glycidoxypropyltrimethoxy silane (GPS) to glass decreased the pull-off forces relative to the clean glass and made the surface mo...
CIME-CIRM course Rationality Problems in Algebraic Geometry
Pirola, Gian
2016-01-01
Providing an overview of the state of the art on rationality questions in algebraic geometry, this volume gives an update on the most recent developments. It offers a comprehensive introduction to this fascinating topic, and will certainly become an essential reference for anybody working in the field. Rationality problems are of fundamental importance both in algebra and algebraic geometry. Historically, rationality problems motivated significant developments in the theory of abelian integrals, Riemann surfaces and the Abel–Jacobi map, among other areas, and they have strong links with modern notions such as moduli spaces, Hodge theory, algebraic cycles and derived categories. This text is aimed at researchers and graduate students in algebraic geometry.
Liu, Xinran; Kofman, Jonathan
2017-07-10
A new fringe projection method for surface-shape measurement was developed using four high-frequency phase-shifted background modulation fringe patterns. The pattern frequency is determined using a new fringe-wavelength geometry-constraint model that allows only two corresponding-point candidates in the measurement volume. The correct corresponding point is selected with high reliability using a binary pattern computed from intensity background encoded in the fringe patterns. Equations of geometry-constraint parameters permit parameter calculation prior to measurement, thus reducing measurement computational cost. Experiments demonstrated the ability of the method to perform 3D shape measurement for a surface with geometric discontinuity, and for spatially isolated objects.
Czech Academy of Sciences Publication Activity Database
Boudík, F.; Anger, Z.; Aschermann, M.; Vojáček, J.; Tomečková, Marie
2002-01-01
Roč. 35, č. 3 (2002), s. 181-191 ISSN 0022-0736 R&D Projects: GA MZd IZ4038 Keywords : body surface potential mapping * dipyridamole * coronary artery disease * syndrome X Subject RIV: BD - Theory of Information Impact factor: 0.599, year: 2002
Sun, Jingya
2016-02-25
Selectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser’s relatively large penetration depth and consequently they record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and sub-picosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample’s surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystals and its powder film. We also provide the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces.
Sun, Jingya; Adhikari, Aniruddha; Shaheen, Basamat; Yang, Haoze; Mohammed, Omar F.
2016-01-01
Selectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser’s relatively large penetration depth and consequently they record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and sub-picosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample’s surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystals and its powder film. We also provide the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces.
Active and Passive Remote Sensing Data Time Series for Flood Detection and Surface Water Mapping
Bioresita, Filsa; Puissant, Anne; Stumpf, André; Malet, Jean-Philippe
2017-04-01
As a consequence of environmental changes surface waters are undergoing changes in time and space. A better knowledge of the spatial and temporal distribution of surface waters resources becomes essential to support sustainable policies and development activities. Especially because surface waters, are not only a vital sweet water resource, but can also pose hazards to human settlements and infrastructures through flooding. Floods are a highly frequent disaster in the world and can caused huge material losses. Detecting and mapping their spatial distribution is fundamental to ascertain damages and for relief efforts. Spaceborne Synthetic Aperture Radar (SAR) is an effective way to monitor surface waters bodies over large areas since it provides excellent temporal coverage and, all-weather day-and-night imaging capabilities. However, emergent vegetation, trees, wind or flow turbulence can increase radar back-scatter returns and pose problems for the delineation of inundated areas. In such areas, passive remote sensing data can be used to identify vegetated areas and support the interpretation of SAR data. The availability of new Earth Observation products, for example Sentinel-1 (active) and Sentinel-2 (passive) imageries, with both high spatial and temporal resolution, have the potential to facilitate flood detection and monitoring of surface waters changes which are very dynamic in space and time. In this context, the research consists of two parts. In the first part, the objective is to propose generic and reproducible methodologies for the analysis of Sentinel-1 time series data for floods detection and surface waters mapping. The processing chain comprises a series of pre-processing steps and the statistical modeling of the pixel value distribution to produce probabilistic maps for the presence of surface waters. Images pre-processing for all Sentinel-1 images comprise the reduction SAR effect like orbit errors, speckle noise, and geometric effects. A modified
Rodger, Alison
1995-01-01
Molecular Geometry discusses topics relevant to the arrangement of atoms. The book is comprised of seven chapters that tackle several areas of molecular geometry. Chapter 1 reviews the definition and determination of molecular geometry, while Chapter 2 discusses the unified view of stereochemistry and stereochemical changes. Chapter 3 covers the geometry of molecules of second row atoms, and Chapter 4 deals with the main group elements beyond the second row. The book also talks about the complexes of transition metals and f-block elements, and then covers the organometallic compounds and trans
Globalland30 Mapping Capacity of Land Surface Water in Thessaly, Greece
Directory of Open Access Journals (Sweden)
Ioannis Manakos
2014-12-01
Full Text Available The National Geomatics Center of China (NGCC produced Global Land Cover (GlobalLand30 maps with 30 m spatial resolution for the years 2000 and 2009–2010, responding to the need for harmonized, accurate, and high-resolution global land cover data. This study aims to assess the mapping accuracy of the land surface water layer of GlobalLand30 for 2009–2010. A representative Mediterranean region, situated in Greece, is considered as the case study area, with 2009 as the reference year. The assessment is realized through an object-based comparison of the GlobalLand30 water layer with the ground truth and visually interpreted data from the Hellenic Cadastre fine spatial resolution (0.5 m orthophoto map layer. GlobCover 2009, GlobCorine 2009, and GLCNMO 2008 corresponding thematic layers are utilized to show and quantify the progress brought along with the increment of the spatial resolution, from 500 m to 300 m and finally to 30 m with the newly produced GlobalLand30 maps. GlobalLand30 detected land surface water areas show a 91.9% overlap with the reference data, while the coarser resolution products are restricted to lower accuracies. Validation is extended to the drainage network elements, i.e., rivers and streams, where GlobalLand30 outperforms the other global map products, as well.
Surface materials map of Afghanistan: iron-bearing minerals and other materials
King, Trude V.V.; Kokaly, Raymond F.; Hoefen, Todd M.; Dudek, Kathleen B.; Livo, Keith E.
2012-01-01
This map shows the distribution of selected iron-bearing minerals and other materials derived from analysis of HyMap imaging spectrometer data of Afghanistan. Using a NASA (National Aeronautics and Space Administration) WB-57 aircraft flown at an altitude of ~15,240 meters or ~50,000 feet, 218 flight lines of data were collected over Afghanistan between August 22 and October 2, 2007. The HyMap data were converted to apparent surface reflectance, then further empirically adjusted using ground-based reflectance measurements. The reflectance spectrum of each pixel of HyMap data was compared to the spectral features of reference entries in a spectral library of minerals, vegetation, water, ice, and snow. This map shows the spatial distribution of iron-bearing minerals and other materials having diagnostic absorptions at visible and near-infrared wavelengths. These absorptions result from electronic processes in the minerals. Several criteria, including (1) the reliability of detection and discrimination of minerals using the HyMap spectrometer data, (2) the relative abundance of minerals, and (3) the importance of particular minerals to studies of Afghanistan's natural resources, guided the selection of entries in the reference spectral library and, therefore, guided the selection of mineral classes shown on this map. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated. Minerals having similar spectral features were less easily discriminated, especially where the minerals were not particularly abundant and (or) where vegetation cover reduced the absorption strength of mineral features. Complications in reflectance calibration also affected the detection and identification of minerals.
Kokaly, Raymond F.; King, Trude V.V.; Hoefen, Todd M.; Dudek, Kathleen B.; Livo, Keith E.
2012-01-01
This map shows the distribution of selected carbonates, phyllosilicates, sulfates, altered minerals, and other materials derived from analysis of HyMap imaging spectrometer data of Afghanistan. Using a NASA (National Aeronautics and Space Administration) WB-57 aircraft flown at an altitude of ~15,240 meters or ~50,000 feet, 218 flight lines of data were collected over Afghanistan between August 22 and October 2, 2007. The HyMap data were converted to apparent surface reflectance, then further empirically adjusted using ground-based reflectance measurements. The reflectance spectrum of each pixel of HyMap data was compared to the spectral features of reference entries in a spectral library of minerals, vegetation, water, ice, and snow. This map shows the spatial distribution of minerals that have diagnostic absorption features in the shortwave infrared wavelengths. These absorption features result primarily from characteristic chemical bonds and mineralogical vibrations. Several criteria, including (1) the reliability of detection and discrimination of minerals using the HyMap spectrometer data, (2) the relative abundance of minerals, and (3) the importance of particular minerals to studies of Afghanistan's natural resources, guided the selection of entries in the reference spectral library and, therefore, guided the selection of mineral classes shown on this map. Minerals occurring abundantly at the surface and those having unique spectral features were easily detected and discriminated. Minerals having similar spectral features were less easily discriminated, especially where the minerals were not particularly abundant and (or) where vegetation cover reduced the absorption strength of mineral features. Complications in reflectance calibration also affected the detection and identification of minerals.
Lectures on Symplectic Geometry
Silva, Ana Cannas
2001-01-01
The goal of these notes is to provide a fast introduction to symplectic geometry for graduate students with some knowledge of differential geometry, de Rham theory and classical Lie groups. This text addresses symplectomorphisms, local forms, contact manifolds, compatible almost complex structures, Kaehler manifolds, hamiltonian mechanics, moment maps, symplectic reduction and symplectic toric manifolds. It contains guided problems, called homework, designed to complement the exposition or extend the reader's understanding. There are by now excellent references on symplectic geometry, a subset of which is in the bibliography of this book. However, the most efficient introduction to a subject is often a short elementary treatment, and these notes attempt to serve that purpose. This text provides a taste of areas of current research and will prepare the reader to explore recent papers and extensive books on symplectic geometry where the pace is much faster. For this reprint numerous corrections and cl...
International Nuclear Information System (INIS)
Robinson, I.; Trautman, A.
1988-01-01
The geometry of classical physics is Lorentzian; but weaker geometries are often more appropriate: null geodesics and electromagnetic fields, for example, are well known to be objects of conformal geometry. To deal with a single null congruence, or with the radiative electromagnetic fields associated with it, even less is needed: flag geometry for the first, optical geometry, with which this paper is chiefly concerned, for the second. The authors establish a natural one-to-one correspondence between optical geometries, considered locally, and three-dimensional Cauchy-Riemann structures. A number of Lorentzian geometries are shown to be equivalent from the optical point of view. For example the Goedel universe, the Taub-NUT metric and Hauser's twisting null solution have an optical geometry isomorphic to the one underlying the Robinson congruence in Minkowski space. The authors present general results on the problem of lifting a CR structure to a Lorentz manifold and, in particular, to Minkowski space; and exhibit the relevance of the deviation form to this problem
Lee, Cholyoung; Kim, Kyehyun; Lee, Hyuk
2018-01-15
Impervious surfaces are mainly artificial structures such as rooftops, roads, and parking lots that are covered by impenetrable materials. These surfaces are becoming the major causes of nonpoint source (NPS) pollution in urban areas. The rapid progress of urban development is increasing the total amount of impervious surfaces and NPS pollution. Therefore, many cities worldwide have adopted a stormwater utility fee (SUF) that generates funds needed to manage NPS pollution. The amount of SUF is estimated based on the impervious ratio, which is calculated by dividing the total impervious surface area by the net area of an individual land parcel. Hence, in order to identify the exact impervious ratio, large-scale impervious surface maps (ISMs) are necessary. This study proposes and assesses various methods for generating large-scale ISMs for urban areas by using existing GIS data. Bupyeong-gu, a district in the city of Incheon, South Korea, was selected as the study area. Spatial data that were freely offered by national/local governments in S. Korea were collected. First, three types of ISMs were generated by using the land-cover map, digital topographic map, and orthophotographs, to validate three methods that had been proposed conceptually by Korea Environment Corporation. Then, to generate an ISM of higher accuracy, an integration method using all data was proposed. Error matrices were made and Kappa statistics were calculated to evaluate the accuracy. Overlay analyses were performed to examine the distribution of misclassified areas. From the results, the integration method delivered the highest accuracy (Kappa statistic of 0.99) compared to the three methods that use a single type of spatial data. However, a longer production time and higher cost were limiting factors. Among the three methods using a single type of data, the land-cover map showed the highest accuracy with a Kappa statistic of 0.91. Thus, it was judged that the mapping method using the land
Hayashi, Shigehiko; Uchida, Yoshihiro; Hasegawa, Taisuke; Higashi, Masahiro; Kosugi, Takahiro; Kamiya, Motoshi
2017-05-05
Many remarkable molecular functions of proteins use their characteristic global and slow conformational dynamics through coupling of local chemical states in reaction centers with global conformational changes of proteins. To theoretically examine the functional processes of proteins in atomic detail, a methodology of quantum mechanical/molecular mechanical (QM/MM) free-energy geometry optimization is introduced. In the methodology, a geometry optimization of a local reaction center is performed with a quantum mechanical calculation on a free-energy surface constructed with conformational samples of the surrounding protein environment obtained by a molecular dynamics simulation with a molecular mechanics force field. Geometry optimizations on extensive free-energy surfaces by a QM/MM reweighting free-energy self-consistent field method designed to be variationally consistent and computationally efficient have enabled examinations of the multiscale molecular coupling of local chemical states with global protein conformational changes in functional processes and analysis and design of protein mutants with novel functional properties.
Aspects of differential geometry II
Gilkey, Peter
2015-01-01
Differential Geometry is a wide field. We have chosen to concentrate upon certain aspects that are appropriate for an introduction to the subject; we have not attempted an encyclopedic treatment. Book II deals with more advanced material than Book I and is aimed at the graduate level. Chapter 4 deals with additional topics in Riemannian geometry. Properties of real analytic curves given by a single ODE and of surfaces given by a pair of ODEs are studied, and the volume of geodesic balls is treated. An introduction to both holomorphic and Kähler geometry is given. In Chapter 5, the basic properties of de Rham cohomology are discussed, the Hodge Decomposition Theorem, Poincaré duality, and the Künneth formula are proved, and a brief introduction to the theory of characteristic classes is given. In Chapter 6, Lie groups and Lie algebras are dealt with. The exponential map, the classical groups, and geodesics in the context of a bi-invariant metric are discussed. The de Rham cohomology of compact Lie groups an...
Directory of Open Access Journals (Sweden)
Płocica Mieczysław
2014-08-01
Full Text Available The paper describes the possibilities of bevel gears kinematics design on the basis of the motion graph and improving modifications to cut the pinion teeth flanks. The result is the ability to increase the accuracy of the kinematic transmission. The issue of changing the geometry of the pinion gear is considered in respect of a gear intended for the use in aviation, which requires the cooperation of high quality meshing. The basic geometric features that have been modified include the profile angle, the angle of tooth line, crowning trans-verse and longitudinal and lateral surface twist angle of the tooth. The modification of each of the selected geometrical parameters has had a different effect on the chart of transmission. It has been shown that the effect of the intended changes in the geometry of the pinion may reduce the deviation of motion delays gear and an improve the gear transmission chart.
Wide-Baseline Stereo-Based Obstacle Mapping for Unmanned Surface Vehicles
Mou, Xiaozheng; Wang, Han
2018-01-01
This paper proposes a wide-baseline stereo-based static obstacle mapping approach for unmanned surface vehicles (USVs). The proposed approach eliminates the complicated calibration work and the bulky rig in our previous binocular stereo system, and raises the ranging ability from 500 to 1000 m with a even larger baseline obtained from the motion of USVs. Integrating a monocular camera with GPS and compass information in this proposed system, the world locations of the detected static obstacles are reconstructed while the USV is traveling, and an obstacle map is then built. To achieve more accurate and robust performance, multiple pairs of frames are leveraged to synthesize the final reconstruction results in a weighting model. Experimental results based on our own dataset demonstrate the high efficiency of our system. To the best of our knowledge, we are the first to address the task of wide-baseline stereo-based obstacle mapping in a maritime environment. PMID:29617293
Gahm, Jin Kyu; Shi, Yonggang
2018-05-01
Surface mapping methods play an important role in various brain imaging studies from tracking the maturation of adolescent brains to mapping gray matter atrophy patterns in Alzheimer's disease. Popular surface mapping approaches based on spherical registration, however, have inherent numerical limitations when severe metric distortions are present during the spherical parameterization step. In this paper, we propose a novel computational framework for intrinsic surface mapping in the Laplace-Beltrami (LB) embedding space based on Riemannian metric optimization on surfaces (RMOS). Given a diffeomorphism between two surfaces, an isometry can be defined using the pullback metric, which in turn results in identical LB embeddings from the two surfaces. The proposed RMOS approach builds upon this mathematical foundation and achieves general feature-driven surface mapping in the LB embedding space by iteratively optimizing the Riemannian metric defined on the edges of triangular meshes. At the core of our framework is an optimization engine that converts an energy function for surface mapping into a distance measure in the LB embedding space, which can be effectively optimized using gradients of the LB eigen-system with respect to the Riemannian metrics. In the experimental results, we compare the RMOS algorithm with spherical registration using large-scale brain imaging data, and show that RMOS achieves superior performance in the prediction of hippocampal subfields and cortical gyral labels, and the holistic mapping of striatal surfaces for the construction of a striatal connectivity atlas from substantia nigra. Copyright © 2018 Elsevier B.V. All rights reserved.
Pottmann, Helmut; Eigensatz, Michael; Vaxman, Amir; Wallner, Johannes
2014-01-01
Around 2005 it became apparent in the geometry processing community that freeform architecture contains many problems of a geometric nature to be solved, and many opportunities for optimization which however require geometric understanding. This area of research, which has been called architectural geometry, meanwhile contains a great wealth of individual contributions which are relevant in various fields. For mathematicians, the relation to discrete differential geometry is significant, in particular the integrable system viewpoint. Besides, new application contexts have become available for quite some old-established concepts. Regarding graphics and geometry processing, architectural geometry yields interesting new questions but also new objects, e.g. replacing meshes by other combinatorial arrangements. Numerical optimization plays a major role but in itself would be powerless without geometric understanding. Summing up, architectural geometry has become a rewarding field of study. We here survey the main directions which have been pursued, we show real projects where geometric considerations have played a role, and we outline open problems which we think are significant for the future development of both theory and practice of architectural geometry.
Pottmann, Helmut
2014-11-26
Around 2005 it became apparent in the geometry processing community that freeform architecture contains many problems of a geometric nature to be solved, and many opportunities for optimization which however require geometric understanding. This area of research, which has been called architectural geometry, meanwhile contains a great wealth of individual contributions which are relevant in various fields. For mathematicians, the relation to discrete differential geometry is significant, in particular the integrable system viewpoint. Besides, new application contexts have become available for quite some old-established concepts. Regarding graphics and geometry processing, architectural geometry yields interesting new questions but also new objects, e.g. replacing meshes by other combinatorial arrangements. Numerical optimization plays a major role but in itself would be powerless without geometric understanding. Summing up, architectural geometry has become a rewarding field of study. We here survey the main directions which have been pursued, we show real projects where geometric considerations have played a role, and we outline open problems which we think are significant for the future development of both theory and practice of architectural geometry.
Mapping surface charge density of lipid bilayers by quantitative surface conductivity microscopy
DEFF Research Database (Denmark)
Klausen, Lasse Hyldgaard; Fuhs, Thomas; Dong, Mingdong
2016-01-01
Local surface charge density of lipid membranes influences membrane-protein interactions leading to distinct functions in all living cells, and it is a vital parameter in understanding membrane-binding mechanisms, liposome design and drug delivery. Despite the significance, no method has so far...
Surface strain rate colour map of the Tatra Mountains region (Slovakia based on GNSS data
Directory of Open Access Journals (Sweden)
Bednárik Martin
2016-12-01
Full Text Available The surface deformation of the Tatra Mountains region in Western Carpathians can nowadays be studied directly thanks to precise geodetic measurements using the GNSS. The strain or stress tensor field is, however, a rather complex “data structure” difficult to present legibly and with sufficient resolution in the form of a classical map. A novel and promising approach to the solution of this problem is coding the three principal strain or stress values into the three colour channels (red, green, blue of an RGB colour. In our previous study, the colour depended on the stress tensor shape descriptors. In the current study, the adapted colouring scheme uses a subset of shape descriptors common to stress and strain, which differ only in the scaling factor. In this manner, we generate the colour map of the surface strain rate field, where the colour of each grid point carries the information about the shape of the strain rate tensor at that point. The resulting strain rate colour map can be displayed simultaneously with the map of the faults or elevations and be easily checked for the data or interpolation method errors and incompatibility with the geophysical and geological expectations.
Maor, Eli
2014-01-01
If you've ever thought that mathematics and art don't mix, this stunning visual history of geometry will change your mind. As much a work of art as a book about mathematics, Beautiful Geometry presents more than sixty exquisite color plates illustrating a wide range of geometric patterns and theorems, accompanied by brief accounts of the fascinating history and people behind each. With artwork by Swiss artist Eugen Jost and text by acclaimed math historian Eli Maor, this unique celebration of geometry covers numerous subjects, from straightedge-and-compass constructions to intriguing configur
Note: Electron energy spectroscopy mapping of surface with scanning tunneling microscope.
Li, Meng; Xu, Chunkai; Zhang, Panke; Li, Zhean; Chen, Xiangjun
2016-08-01
We report a novel scanning probe electron energy spectrometer (SPEES) which combines a double toroidal analyzer with a scanning tunneling microscope to achieve both topography imaging and electron energy spectroscopy mapping of surface in situ. The spatial resolution of spectroscopy mapping is determined to be better than 0.7 ± 0.2 μm at a tip sample distance of 7 μm. Meanwhile, the size of the field emission electron beam spot on the surface is also measured, and is about 3.6 ± 0.8 μm in diameter. This unambiguously demonstrates that the spatial resolution of SPEES technique can be much better than the size of the incident electron beam.
Note: Electron energy spectroscopy mapping of surface with scanning tunneling microscope
Energy Technology Data Exchange (ETDEWEB)
Li, Meng; Xu, Chunkai, E-mail: xuck@ustc.edu.cn, E-mail: xjun@ustc.edu.cn; Zhang, Panke; Li, Zhean; Chen, Xiangjun, E-mail: xuck@ustc.edu.cn, E-mail: xjun@ustc.edu.cn [Hefei National Laboratory for Physical Science at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026 (China)
2016-08-15
We report a novel scanning probe electron energy spectrometer (SPEES) which combines a double toroidal analyzer with a scanning tunneling microscope to achieve both topography imaging and electron energy spectroscopy mapping of surface in situ. The spatial resolution of spectroscopy mapping is determined to be better than 0.7 ± 0.2 μm at a tip sample distance of 7 μm. Meanwhile, the size of the field emission electron beam spot on the surface is also measured, and is about 3.6 ± 0.8 μm in diameter. This unambiguously demonstrates that the spatial resolution of SPEES technique can be much better than the size of the incident electron beam.
Note: Electron energy spectroscopy mapping of surface with scanning tunneling microscope
International Nuclear Information System (INIS)
Li, Meng; Xu, Chunkai; Zhang, Panke; Li, Zhean; Chen, Xiangjun
2016-01-01
We report a novel scanning probe electron energy spectrometer (SPEES) which combines a double toroidal analyzer with a scanning tunneling microscope to achieve both topography imaging and electron energy spectroscopy mapping of surface in situ. The spatial resolution of spectroscopy mapping is determined to be better than 0.7 ± 0.2 μm at a tip sample distance of 7 μm. Meanwhile, the size of the field emission electron beam spot on the surface is also measured, and is about 3.6 ± 0.8 μm in diameter. This unambiguously demonstrates that the spatial resolution of SPEES technique can be much better than the size of the incident electron beam.
A Novel Sensory Mapping Design for Bipedal Walking on a Sloped Surface
Directory of Open Access Journals (Sweden)
Chiao-Min Wu
2012-10-01
Full Text Available This paper presents an environment recognition method for bipedal robots using a time-delay neural network. For a robot to walk in a varying terrain, it is desirable that the robot can adapt to any environment encountered in real-time. This paper aims to develop a sensory mapping unit to recognize environment types from the input sensory data based on an artificial neural network approach. With the proposed sensory mapping design, a bipedal walking robot can obtain real-time environment information and select an appropriate walking pattern accordingly. Due to the time-dependent property of sensory data, the sensory mapping is realized by using a time-delay neural network. The sensory data of earlier time sequences combined with current sensory data are sent to the neural network. The proposed method has been implemented on the humanoid robot NAO for verification. Several interesting experiments were carried out to verify the effectiveness of the sensory mapping design. The mapping design is validated for the uphill, downhill and flat surface cases, where three types of environment can be recognized by the NAO robot online.
Directory of Open Access Journals (Sweden)
Ying Qu
2015-01-01
Full Text Available Surface albedo is one of the key controlling geophysical parameters in the surface energy budget studies, and its temporal and spatial variation is closely related to the global climate change and regional weather system due to the albedo feedback mechanism. As an efficient tool for monitoring the surfaces of the Earth, remote sensing is widely used for deriving long-term surface broadband albedo with various geostationary and polar-orbit satellite platforms in recent decades. Moreover, the algorithms for estimating surface broadband albedo from satellite observations, including narrow-to-broadband conversions, bidirectional reflectance distribution function (BRDF angular modeling, direct-estimation algorithm and the algorithms for estimating albedo from geostationary satellite data, are developed and improved. In this paper, we present a comprehensive literature review on algorithms and products for mapping surface broadband albedo with satellite observations and provide a discussion of different algorithms and products in a historical perspective based on citation analysis of the published literature. This paper shows that the observation technologies and accuracy requirement of applications are important, and long-term, global fully-covered (including land, ocean, and sea-ice surfaces, gap-free, surface broadband albedo products with higher spatial and temporal resolution are required for climate change, surface energy budget, and hydrological studies.
Adhesion mapping of chemically modified and poly(ethylene oxide)-grafted glass surfaces.
Jogikalmath, G; Stuart, J K; Pungor, A; Hlady, V
1999-08-01
Two-dimensional mapping of the adhesion pull-off forces was used to study the origin of surface heterogeneity in the grafted poly(ethylene oxide) (PEO) layer. The variance of the pull-off forces measured over the μm-sized regions after each chemical step of modifying glass surfaces was taken to be a measure of the surface chemical heterogeneity. The attachment of γ-glycidoxypropyltrimethoxy silane (GPS) to glass decreased the pull-off forces relative to the clean glass and made the surface more uniform. The subsequent hydrolysis of the terminal epoxide groups resulted in a larger surface heterogeneity which was modeled by two populations of the terminal hydroxyl groups, each with its own distribution of adhesion forces and force variance. The activation of the hydroxyls with carbonyldiimmidazole (CDI) healed the surface and lowered its adhesion, however, the force variance remained rather large. Finally, the grafting of the α,ω-diamino poly(ethyleneoxide) chains to the CDI-activated glass largely eliminated adhesion except at a few discrete regions. The adhesion on the PEO grafted layer followed the Poisson distribution of the pull-off forces. With the exception of the glass surface, a correlation between the water contact angles and the mean pull-off forces measured with the Si(3)N(4) tip surfaces was found for all modified glass surfaces.
Directory of Open Access Journals (Sweden)
Pervov Alexey
2016-01-01
Full Text Available Modern theoretical understanding of colloidal and suspended matter membrane fouling mechanisms are presented and discussed. State-of-the-art simulation models of concentration polarization calculations for different channel conditions are described and influence of the fouling layers on the flux and rejection decrease are evaluated. Results of experimental investigations are presented that suggest a quantitative evaluation of fouling rates and membrane flux prognosis due to colloidal fouling with time. The influence of channel geometry on fouling is demonstrated and discussed. The main disadvantage of spiral wounded membrane modules which is attributed to the presence of a separation spacer mesh in the feed channel is discussed.
[Application Progress of Three-dimensional Laser Scanning Technology in Medical Surface Mapping].
Zhang, Yonghong; Hou, He; Han, Yuchuan; Wang, Ning; Zhang, Ying; Zhu, Xianfeng; Wang, Mingshi
2016-04-01
The booming three-dimensional laser scanning technology can efficiently and effectively get spatial three-dimensional coordinates of the detected object surface and reconstruct the image at high speed,high precision and large capacity of information.Non-radiation,non-contact and the ability of visualization make it increasingly popular in three-dimensional surface medical mapping.This paper reviews the applications and developments of three-dimensional laser scanning technology in medical field,especially in stomatology,plastic surgery and orthopedics.Furthermore,the paper also discusses the application prospects in the future as well as the biomedical engineering problems it would encounter with.
Exercise body surface potential mapping in single and multiple coronary artery disease
International Nuclear Information System (INIS)
Montague, T.J.; Witkowski, F.X.; Miller, R.M.; Johnstone, D.E.; MacKenzie, R.B.; Spencer, C.A.; Horacek, B.M.
1990-01-01
Body surface ST integral maps were recorded in 36 coronary artery disease (CAD) patients at: rest; peak, angina-limited exercise; and, 1 and 5 min of recovery. They were compared to maps of 15 CAD patients who exercised to fatigue, without angina, and eight normal subjects. Peak exercise heart rates were similar (NS) in all groups. With exercise angina, patients with two and three vessel CAD had significantly (p less than 0.05) greater decrease in the body surface sum of ST integral values than patients with single vessel CAD. CAD patients with exercise fatigue, in the absence of angina, had decreased ST integrals similar (NS) to patients with single vessel CAD who manifested angina and the normal control subjects. There was, however, considerable overlap among individuals; some patients with single vessel CAD had as much exercise ST integral decrease as patients with three vessel CAD. All CAD patients had persistent ST integral decreases at 5 min of recovery and there was a direct correlation of the recovery and peak exercise ST changes. Exercise ST changes correlated, as well, with quantitative CAD angiographic scores, but not with thallium perfusion scores. These data suggest exercise ST integral body surface mapping allows quantitation of myocardium at ischemic risk in patients with CAD, irrespective of the presence or absence of ischemic symptoms during exercise. A major potential application of this technique is selection of CAD therapy guided by quantitative assessment of ischemic myocardial risk
Du, Jia; Younes, Laurent; Qiu, Anqi
2011-01-01
This paper introduces a novel large deformation diffeomorphic metric mapping algorithm for whole brain registration where sulcal and gyral curves, cortical surfaces, and intensity images are simultaneously carried from one subject to another through a flow of diffeomorphisms. To the best of our knowledge, this is the first time that the diffeomorphic metric from one brain to another is derived in a shape space of intensity images and point sets (such as curves and surfaces) in a unified manner. We describe the Euler–Lagrange equation associated with this algorithm with respect to momentum, a linear transformation of the velocity vector field of the diffeomorphic flow. The numerical implementation for solving this variational problem, which involves large-scale kernel convolution in an irregular grid, is made feasible by introducing a class of computationally friendly kernels. We apply this algorithm to align magnetic resonance brain data. Our whole brain mapping results show that our algorithm outperforms the image-based LDDMM algorithm in terms of the mapping accuracy of gyral/sulcal curves, sulcal regions, and cortical and subcortical segmentation. Moreover, our algorithm provides better whole brain alignment than combined volumetric and surface registration (Postelnicu et al., 2009) and hierarchical attribute matching mechanism for elastic registration (HAMMER) (Shen and Davatzikos, 2002) in terms of cortical and subcortical volume segmentation. PMID:21281722
Kemnitz, Arnfried
Der Grundgedanke der Analytischen Geometrie besteht darin, dass geometrische Untersuchungen mit rechnerischen Mitteln geführt werden. Geometrische Objekte werden dabei durch Gleichungen beschrieben und mit algebraischen Methoden untersucht.
Lefschetz, Solomon
2005-01-01
An introduction to algebraic geometry and a bridge between its analytical-topological and algebraical aspects, this text for advanced undergraduate students is particularly relevant to those more familiar with analysis than algebra. 1953 edition.
Ay, Nihat; Lê, Hông Vân; Schwachhöfer, Lorenz
2017-01-01
The book provides a comprehensive introduction and a novel mathematical foundation of the field of information geometry with complete proofs and detailed background material on measure theory, Riemannian geometry and Banach space theory. Parametrised measure models are defined as fundamental geometric objects, which can be both finite or infinite dimensional. Based on these models, canonical tensor fields are introduced and further studied, including the Fisher metric and the Amari-Chentsov tensor, and embeddings of statistical manifolds are investigated. This novel foundation then leads to application highlights, such as generalizations and extensions of the classical uniqueness result of Chentsov or the Cramér-Rao inequality. Additionally, several new application fields of information geometry are highlighted, for instance hierarchical and graphical models, complexity theory, population genetics, or Markov Chain Monte Carlo. The book will be of interest to mathematicians who are interested in geometry, inf...
Real-space Mapping of Surface Trap States in CIGSe Nanocrystals using 4D Electron Microscopy
Bose, Riya
2016-05-26
Surface trap states in semiconductor copper indium gallium selenide nanocrystals (NCs) which serve as undesirable channels for non-radiative carrier recombination, remain a great challenge impeding the development of solar and optoelectronics devices based on these NCs. In order to design efficient passivation techniques to minimize these trap states, a precise knowledge about the charge carrier dynamics on the NCs surface is essential. However, selective mapping of surface traps requires capabilities beyond the reach of conventional laser spectroscopy and static electron microscopy; it can only be accessed by using a one-of-a-kind, second-generation four-dimensional scanning ultrafast electron microscope (4D S-UEM) with sub-picosecond temporal and nanometer spatial resolutions. Here, we precisely map the surface charge carrier dynamics of copper indium gallium selenide NCs before and after surface passivation in real space and time using S-UEM. The time-resolved snapshots clearly demonstrate that the density of the trap states is significantly reduced after zinc sulfide (ZnS) shelling. Furthermore, removal of trap states and elongation of carrier lifetime are confirmed by the increased photocurrent of the self-biased photodetector fabricated using the shelled NCs.
Real-space Mapping of Surface Trap States in CIGSe Nanocrystals using 4D Electron Microscopy
Bose, Riya; Bera, Ashok; Parida, Manas R.; Adhikari, Aniruddha; Shaheen, Basamat; Alarousu, Erkki; Sun, Jingya; Wu, Tao; Bakr, Osman; Mohammed, Omar F.
2016-01-01
Surface trap states in semiconductor copper indium gallium selenide nanocrystals (NCs) which serve as undesirable channels for non-radiative carrier recombination, remain a great challenge impeding the development of solar and optoelectronics devices based on these NCs. In order to design efficient passivation techniques to minimize these trap states, a precise knowledge about the charge carrier dynamics on the NCs surface is essential. However, selective mapping of surface traps requires capabilities beyond the reach of conventional laser spectroscopy and static electron microscopy; it can only be accessed by using a one-of-a-kind, second-generation four-dimensional scanning ultrafast electron microscope (4D S-UEM) with sub-picosecond temporal and nanometer spatial resolutions. Here, we precisely map the surface charge carrier dynamics of copper indium gallium selenide NCs before and after surface passivation in real space and time using S-UEM. The time-resolved snapshots clearly demonstrate that the density of the trap states is significantly reduced after zinc sulfide (ZnS) shelling. Furthermore, removal of trap states and elongation of carrier lifetime are confirmed by the increased photocurrent of the self-biased photodetector fabricated using the shelled NCs.
Map of natural gamma radiation in Spain: radiometric characterization of different types of surfaces
International Nuclear Information System (INIS)
Suarez Mahou, E.; Fernandez Amigot, J.A.; Botas Medina, J.
1997-01-01
The gamma radioactivity flowing from ground and rocks is due to the presence in these of uranium, thorium and potassium-40. The method of radiometric characterization depends on the purpose of the undertaking. Radiometric characterization can be realized on big surfaces (tens or hundreds of square kilometres studied on a national scale), medium size surfaces (50 to 1000 square kilometres, for example, in epidemiological or biological studies in areas with a determined radiometric background) small surfaces of less than 50 square kilometres (industrial sites, pre-operational studies, etc.). This article considers aspects of radiometric characterization on surfaces of interest and describes the contribution of the MARNA (Natural Provisional Radiation Map of Spain) Project selection and radiometric characterization
Fasnacht, Zachary; Qin, Wenhan; Haffner, David P.; Loyola, Diego; Joiner, Joanna; Krotkov, Nickolay; Vasilkov, Alexander; Spurr, Robert
2017-01-01
Surface Lambertian-equivalent reflectivity (LER) is important for trace gas retrievals in the direct calculation of cloud fractions and indirect calculation of the air mass factor. Current trace gas retrievals use climatological surface LER's. Surface properties that impact the bidirectional reflectance distribution function (BRDF) as well as varying satellite viewing geometry can be important for retrieval of trace gases. Geometry Dependent LER (GLER) captures these effects with its calculation of sun normalized radiances (I/F) and can be used in current LER algorithms (Vasilkov et al. 2016). Pixel by pixel radiative transfer calculations are computationally expensive for large datasets. Modern satellite missions such as the Tropospheric Monitoring Instrument (TROPOMI) produce very large datasets as they take measurements at much higher spatial and spectral resolutions. Look up table (LUT) interpolation improves the speed of radiative transfer calculations but complexity increases for non-linear functions. Neural networks perform fast calculations and can accurately predict both non-linear and linear functions with little effort.
Flores-McLaughlin, John
2017-08-01
Planetary bodies and spacecraft are predominantly exposed to isotropic radiation environments that are subject to transport and interaction in various material compositions and geometries. Specifically, the Martian surface radiation environment is composed of galactic cosmic radiation, secondary particles produced by their interaction with the Martian atmosphere, albedo particles from the Martian regolith and occasional solar particle events. Despite this complex physical environment with potentially significant locational and geometric dependencies, computational resources often limit radiation environment calculations to a one-dimensional or slab geometry specification. To better account for Martian geometry, spherical volumes with respective Martian material densities are adopted in this model. This physical description is modeled with the PHITS radiation transport code and compared to a portion of measurements from the Radiation Assessment Detector of the Mars Science Laboratory. Particle spectra measured between 15 November 2015 and 15 January 2016 and PHITS model results calculated for this time period are compared. Results indicate good agreement between simulated dose rates, proton, neutron and gamma spectra. This work was originally presented at the 1st Mars Space Radiation Modeling Workshop held in 2016 in Boulder, CO. Copyright © 2017. Published by Elsevier Ltd.
Directory of Open Access Journals (Sweden)
Sara Shafaie
Full Text Available In vitro cell based models have been invaluable tools for studying cell behaviour and for investigating drug disposition, toxicity and potential adverse effects of administered drugs. Within this drug discovery pipeline, the ability to assess and prioritise candidate compounds as soon as possible offers a distinct advantage. However, the ability to apply this approach to a cell culture study is limited by the need to provide an accurate, in vitro-like, microenvironment in conjunction with a low cost and high-throughput screening (HTS methodology. Although the geometry and/or alignment of cells has been reported to have a profound influence on cell growth and differentiation, only a handful of studies have directly compared the growth of a single cell line on different shaped multiwell plates the most commonly used substrate for HTS, in vitro, studies. Herein, the impact of various surface geometries (flat, round and v-shaped 96 well plates, as well as fixed volume growth media and fixed growth surface area have been investigated on the characteristics of three commonly used human cell lines in biopharmaceutical research and development, namely ARPE-19 (retinal epithelial, A549 (alveolar epithelial and Malme-3M (dermal fibroblastic cells. The effect of the surface curvature on cells was characterised using a combination of a metabolic activity assay (CellTiter AQ/MTS, LDH release profiles (CytoTox ONE and absolute cell counts (Guava ViaCount, respectively. In addition, cell differentiation and expression of specific marker proteins were determined using flow cytometry. These in vitro results confirmed that surface topography had a significant effect (p < 0.05 on cell activity and morphology. However, although specific marker proteins were expressed on day 1 and 5 of the experiment, no significant differences were seen between the different plate geometries (p < 0.05 at the later time point. Accordingly, these results highlight the impact of
Pedrera, Antonio; Marín-Lechado, Carlos; Galindo-Zaldívar, Jesús; García-Lobón, José Luis
2014-07-01
We have determined, for the first time, the 3D geometry of a sector of the eastern Internal Prebetic comprised between Parcent and Altea diapirs, combining structural, borehole and multichannel seismic reflection data. The tectonic structure of the Jurassic-Cretaceous carbonate series is characterized by regional ENE-WSW fold-and-thrusts that interact with oblique N-S and WNW-ESE folds, detached over Triassic evaporites and clays. The structural style comprises box-shape anticlines, and N-vergent anticlines with vertical to overturned limbs frequently bordered by reverse and strike-slip faults. The anticlines surround a triangular broad synclinal structure, the Tárbena basin, filled by a late Oligocene to Tortonian sedimentary sequence that recorded folding and thrusting history. The location and geometrical characteristics of fold-and-thrusts may be controlled by the positive inversion of pre-existing Mesozoic normal faults, and by the position and shape of near-surface diapirs composed of Triassic rocks. Therefore, we propose an initial near-surface diapir emplacement of Triassic evaporitic rocks driven by late Jurassic to early Cretaceous rifting of the southern Iberian paleomargin. Thrusting and folding started during the latest Oligocene (∼28-23 Ma) roughly orthogonal to the NW-directed shortening. Deformation migrated to the south during Aquitanian (∼23-20 Ma), when tectonic inversion implied the left-lateral transpressive reactivation of N-S striking former normal faults and right-lateral/reverse reactivation of inherited WNW-ESE faults. We show two mechanisms driving the extrusion of the diapirs during contraction: lateral migration of a pre-existing near-surface diapir associated with dextral transpression; and squeezing of a previous near-surface diapir at the front of an anticline. Our study underlines the value of 3D geological modeling to characterize geometry and kinematics of complex fold-and-thrust belts influenced by preexisting faults and
Accuracy Analysis of a Robotic Radionuclide Inspection and Mapping System for Surface Contamination
International Nuclear Information System (INIS)
Mauer, Georg F.; Kawa, Chris
2008-01-01
The mapping of localized regions of radionuclide contamination in a building can be a time consuming and costly task. Humans moving hand-held radiation detectors over the target areas are subject to fatigue. A contamination map based on manual surveys can contain significant operator-induced inaccuracies. A Fanuc M16i light industrial robot has been configured for installation on a mobile aerial work platform, such as a tall forklift. When positioned in front of a wall or floor surface, the robot can map the radiation levels over a surface area of up to 3 m by 3 m. The robot's end effector is a commercial alpha-beta radiation sensor, augmented with range and collision avoidance sensors to ensure operational safety as well as to maintain a constant gap between surface and radiation sensors. The accuracy and repeatability of the robotically conducted contamination surveys is directly influenced by the sensors and other hardware employed. This paper presents an in-depth analysis of various non-contact sensors for gap measurement, and the means to compensate for predicted systematic errors that arise during the area survey scans. The range sensor should maintain a constant gap between the radiation counter and the surface being inspected. The inspection robot scans the wall surface horizontally, moving down at predefined vertical intervals after each scan in a meandering pattern. A number of non-contact range sensors can be employed for the measurement of the gap between the robot end effector and the wall. The nominal gap width was specified as 10 mm, with variations during a single scan not to exceed ± 2 mm. Unfinished masonry or concrete walls typically exhibit irregularities, such as holes, gaps, or indentations in mortar joints. These irregularities can be sufficiently large to indicate a change of the wall contour. The responses of different sensor types to the wall irregularities vary, depending on their underlying principles of operation. We explored
A wafer mapping technique for residual stress in surface micromachined films
International Nuclear Information System (INIS)
Schiavone, G; Murray, J; Smith, S; Walton, A J; Desmulliez, M P Y; Mount, A R
2016-01-01
The design of MEMS devices employing movable structures is crucially dependant on the mechanical behaviour of the deposited materials. It is therefore important to be able to fully characterize the micromachined films and predict with confidence the mechanical properties of patterned structures. This paper presents a characterization technique that enables the residual stress in MEMS films to be mapped at the wafer level by using microstructures released by surface micromachining. These dedicated MEMS test structures and the associated measurement techniques are used to extract localized information on the strain and Young’s modulus of the film under investigation. The residual stress is then determined by numerically coupling this data with a finite element analysis of the structure. This paper illustrates the measurement routine and demonstrates it with a case study using electrochemically deposited alloys of nickel and iron, particularly prone to develop high levels of residual stress. The results show that the technique enables wafer mapping of film non-uniformities and identifies wafer-to-wafer differences. A comparison between the results obtained from the mapping technique and conventional wafer bow measurements highlights the benefits of using a procedure tailored to films that are non-uniform, patterned and surface-micromachined, as opposed to simple standard stress extraction methods. The presented technique reveals detailed information that is generally unexplored when using conventional stress extraction methods such as wafer bow measurements. (paper)
Directory of Open Access Journals (Sweden)
A. Turiel
2009-10-01
Full Text Available Nowadays Earth observation satellites provide information about many relevant variables of the ocean-climate system, such as temperature, moisture, aerosols, etc. However, to retrieve the velocity field, which is the most relevant dynamical variable, is still a technological challenge, specially in the case of oceans. New processing techniques, emerged from the theory of turbulent flows, have come to assist us in this task. In this paper, we show that multifractal techniques applied to new Sea Surface Temperature satellite products opens the way to build maps of ocean currents with unprecedented accuracy. With the application of singularity analysis, we show that global ocean circulation patterns can be retrieved in a daily basis. We compare these results with high-quality altimetry-derived geostrophic velocities, finding a quite good correspondence of the observed patterns both qualitatively and quantitatively; and this is done for the first time on a global basis, even for less active areas. The implications of this findings from the perspective both of theory and of operational applications are discussed.
International Nuclear Information System (INIS)
Fuentes, Nestor O.; Faybishenko, B.
2003-01-01
In order to determine the geometric patterns of the fracture surfaces that imposes conditions on the fluid flow through fractured porous media, a series a fracture models have been analyzed using the RIMAPS technique and the variogram method. Results confirm that the main paths followed by the fluid channels are determined by the surface topography and remain constant during water seepage evolution. Characteristics scale lengths of both situations: fracture surface and the flow of water, are also found. There exists a relationship between the scale lengths corresponding to each situation. (author)
Kollár, János
1997-01-01
This volume contains the lectures presented at the third Regional Geometry Institute at Park City in 1993. The lectures provide an introduction to the subject, complex algebraic geometry, making the book suitable as a text for second- and third-year graduate students. The book deals with topics in algebraic geometry where one can reach the level of current research while starting with the basics. Topics covered include the theory of surfaces from the viewpoint of recent higher-dimensional developments, providing an excellent introduction to more advanced topics such as the minimal model program. Also included is an introduction to Hodge theory and intersection homology based on the simple topological ideas of Lefschetz and an overview of the recent interactions between algebraic geometry and theoretical physics, which involve mirror symmetry and string theory.
Directory of Open Access Journals (Sweden)
Painter Page R
2005-08-01
Full Text Available Abstract Background A prominent theoretical explanation for 3/4-power allometric scaling of metabolism proposes that the nutrient exchange surface of capillaries has properties of a space-filling fractal. The theory assumes that nutrient exchange surface area has a fractal dimension equal to or greater than 2 and less than or equal to 3 and that the volume filled by the exchange surface area has a fractal dimension equal to or greater than 3 and less than or equal to 4. Results It is shown that contradicting predictions can be derived from the assumptions of the model. When errors in the model are corrected, it is shown to predict that metabolic rate is proportional to body mass (proportional scaling. Conclusion The presence of space-filling fractal nutrient exchange surfaces does not provide a satisfactory explanation for 3/4-power metabolic rate scaling.
International Nuclear Information System (INIS)
Miguel, V.; Martinez-Conesa, E. J.; Segura, F.; Manjabacas, M. C.; Abellan, E.
2012-01-01
The geometry of the weld beads is characterized by the overhead, the width and the penetration. These values are indices of the behavior of the welded joint and therefore, they can be considered as factors that control the process. This work is performed to optimize the GMAW process of the aluminum alloy AA 6063-T5 by means of the response surface methodology (RSM). The variables herein considered are the arc voltage, the welding speed, the wire feed speed and the separation between surfaces in butt joints. The response functions that are herein studied are the overhead, the width, the penetration and the angle of the bead. The obtained results by RSM show high grade of agreement with the experimental values. The procedure is experimentally validated by welding for the theoretically obtained optimized technological conditions and a wide agreement between theoretical and experimental values is found. (Author) 16 refs.
Discrete differential geometry. Consistency as integrability
Bobenko, Alexander I.; Suris, Yuri B.
2005-01-01
A new field of discrete differential geometry is presently emerging on the border between differential and discrete geometry. Whereas classical differential geometry investigates smooth geometric shapes (such as surfaces), and discrete geometry studies geometric shapes with finite number of elements (such as polyhedra), the discrete differential geometry aims at the development of discrete equivalents of notions and methods of smooth surface theory. Current interest in this field derives not ...
Flexible intuitions of Euclidean geometry in an Amazonian indigene group
Izard, Véronique; Pica, Pierre; Spelke, Elizabeth S.; Dehaene, Stanislas
2011-01-01
Kant argued that Euclidean geometry is synthesized on the basis of an a priori intuition of space. This proposal inspired much behavioral research probing whether spatial navigation in humans and animals conforms to the predictions of Euclidean geometry. However, Euclidean geometry also includes concepts that transcend the perceptible, such as objects that are infinitely small or infinitely large, or statements of necessity and impossibility. We tested the hypothesis that certain aspects of nonperceptible Euclidian geometry map onto intuitions of space that are present in all humans, even in the absence of formal mathematical education. Our tests probed intuitions of points, lines, and surfaces in participants from an indigene group in the Amazon, the Mundurucu, as well as adults and age-matched children controls from the United States and France and younger US children without education in geometry. The responses of Mundurucu adults and children converged with that of mathematically educated adults and children and revealed an intuitive understanding of essential properties of Euclidean geometry. For instance, on a surface described to them as perfectly planar, the Mundurucu's estimations of the internal angles of triangles added up to ∼180 degrees, and when asked explicitly, they stated that there exists one single parallel line to any given line through a given point. These intuitions were also partially in place in the group of younger US participants. We conclude that, during childhood, humans develop geometrical intuitions that spontaneously accord with the principles of Euclidean geometry, even in the absence of training in mathematics. PMID:21606377
Robinson, Gilbert de B
2011-01-01
This brief undergraduate-level text by a prominent Cambridge-educated mathematician explores the relationship between algebra and geometry. An elementary course in plane geometry is the sole requirement for Gilbert de B. Robinson's text, which is the result of several years of teaching and learning the most effective methods from discussions with students. Topics include lines and planes, determinants and linear equations, matrices, groups and linear transformations, and vectors and vector spaces. Additional subjects range from conics and quadrics to homogeneous coordinates and projective geom
Connes, Alain
1994-01-01
This English version of the path-breaking French book on this subject gives the definitive treatment of the revolutionary approach to measure theory, geometry, and mathematical physics developed by Alain Connes. Profusely illustrated and invitingly written, this book is ideal for anyone who wants to know what noncommutative geometry is, what it can do, or how it can be used in various areas of mathematics, quantization, and elementary particles and fields.Key Features* First full treatment of the subject and its applications* Written by the pioneer of this field* Broad applications in mathemat
Peinsipp-Byma, E.; Geisler, Jürgen; Bader, Thomas
2009-05-01
System concepts for network enabled image-based ISR (intelligence, surveillance, reconnaissance) is the major mission of Fraunhofer IITB's applied research in the area of defence and security solutions. For the TechDemo08 as part of the NATO CNAD POW Defence against terrorism Fraunhofer IITB advanced a new multi display concept to handle the shear amount and high complexity of ISR data acquired by networked, distributed surveillance systems with the objective to support the generation of a common situation picture. Amount and Complexity of ISR data demands an innovative man-machine interface concept for humans to deal with it. The IITB's concept is the Digital Map & Situation Surface. This concept offers to the user a coherent multi display environment combining a horizontal surface for the situation overview from the bird's eye view, an attached vertical display for collateral information and so-called foveatablets as personalized magic lenses in order to obtain high resolved and role-specific information about a focused areaof- interest and to interact with it. In the context of TechDemo08 the Digital Map & Situation Surface served as workspace for team-based situation visualization and analysis. Multiple sea- and landside surveillance components were connected to the system.
Landing Site Selection and Surface Traverse Planning using the Lunar Mapping & Modeling Portal
Law, E.; Chang, G.; Bui, B.; Sadaqathullah, S.; Kim, R.; Dodge, K.; Malhotra, S.
2013-12-01
Introduction: The Lunar Mapping and Modeling Portal (LMMP), is a web-based Portal and a suite of interactive visualization and analysis tools for users to access mapped lunar data products (including image mosaics, digital elevation models, etc.) from past and current lunar missions (e.g., Lunar Reconnaissance Orbiter, Apollo, etc.), and to perform in-depth analyses to support lunar surface mission planning and system design for future lunar exploration and science missions. It has been widely used by many scientists mission planners, as well as educators and public outreach (e.g., Google Lunar XPRICE teams, RESOLVE project, museums etc.) This year, LMMP was used by the Lunar and Planetary Institute (LPI)'s Lunar Exploration internship program to perform lighting analysis and local hazard assessments, such as, slope, surface roughness and crater/boulder distribution to research landing sites and surface pathfinding and traversal. Our talk will include an overview of LMMP, a demonstration of the tools as well as a summary of the LPI Lunar Exploration summer interns' experience in using those tools.
Indian Academy of Sciences (India)
mathematicians are trained to use very precise language, and so find it hard to simplify and state .... thing. If you take a plane on which there are two such triangles which enjoy the above ... within this geometry to simplify things if needed.
Geometry -----------~--------------RESONANCE
Indian Academy of Sciences (India)
Parallel: A pair of lines in a plane is said to be parallel if they do not meet. Mathematicians were at war ... Subsequently, Poincare, Klein, Beltrami and others refined non-. Euclidean geometry. ... plane divides the plane into two half planes and.
International Nuclear Information System (INIS)
Calahonra, C; De Las Heras, E; De La Serena, F; Corengia, P; Ybarra, G; Svoboda, H
2004-01-01
Steel AISI 4140 pieces containing cylindrical pinholes with different diameters and depths were nitrited by plasma, in an atmosphere of 25% N 2 + 75% H 2 under a DC-pulsed glow discharge for 15 h. The samples were nitrited to study the influence of the sizes of the pinholes on the uniformity of the compound layer, on the depth of the zone of diffusion and on the surface and subsurface micro-hardness. The results showed that nitriding pieces with pinholes introduces variations in the electric parameters and modifies the uniformity of the coat of compounds formed, altering the mechanical properties of the surface and subsurface (CW)
International Nuclear Information System (INIS)
Barna, B.A.; Johnson, J.A.
1981-01-01
Improvements in ultrasonic imaging that can be obtained using algorithms that map the surface of targets are evaluated. This information is incorporated in the application of synthetic-aperture focusing techniques which also have the potential to improve image resolution. Images obtained using directed-beam (flat) transducers and the focused transducers normally used for synthetic-aperture processing are quantitatively compared by using no processing, synthetic-aperture processing with no corrections for surface variations, and synthetic-aperture processing with surface mapping. The unprocessed images have relatively poor lateral resolutions because echoes from two adjacent reflectors show interference effects which prevent their identification even if the spacing is larger than the single-hole resolution. The synthetic-aperture-processed images show at least a twofold improvement in lateral resolution and greatly reduced interference effects in multiple-hole images compared to directed-beam images. Perhaps more importantly, in images of test blocks with substantial surface variations portions of the image are displaced from their actual positions by several wavelengths. To correct for this effect an algorithm has been developed for calculating the surface variations. The corrected images produced using this algorithm are accurate within the experimental error. In addition, the same algorithm, when applied to the directed-beam data, produced images that are not only accurately positioned, but that also have a resolution comparable to conventional synthetic-aperture-processed images obtained from focused-transducer data. This suggests that using synthetic-aperture processing on the type of data normally collected during directed-beam ultrasonic inspections would eliminate the need to rescan for synthetic-aperture enhancement
Analytical Retrieval of Global Land Surface Emissivity Maps at AMSR-E passive microwave frequencies
Norouzi, H.; Temimi, M.; Khanbilvardi, R.
2009-12-01
Land emissivity is a crucial boundary condition in Numerical Weather Prediction (NWP) modeling. Land emissivity is also a key indicator of land surface and subsurface properties. The objective of this study, supported by NOAA-NESDIS, is to develop global land emissivity maps using AMSR-E passive microwave measurements along with several ancillary data. The International Satellite Cloud Climatology Project (ISCCP) database has been used to obtain several inputs for the proposed approach such as land surface temperature, cloud mask and atmosphere profile. The Community Radiative Transfer Model (CRTM) has been used to estimate upwelling and downwelling atmospheric contributions. Although it is well known that correction of the atmospheric effect on brightness temperature is required at higher frequencies (over 19 GHz), our preliminary results have shown that a correction at 10.7 GHz is also necessary over specific areas. The proposed approach is based on three main steps. First, all necessary data have been collected and processed. Second, a global cloud free composite of AMSR-E data and corresponding ancillary images is created. Finally, monthly composting of emissivity maps has been performed. AMSR-E frequencies at 6.9, 10.7, 18.7, 36.5 and 89.0 GHz have been used to retrieve the emissivity. Water vapor information obtained from ISCCP (TOVS data) was used to calculate upwelling, downwelling temperatures and atmospheric transmission in order to assess the consistency of those derived from the CRTM model. The frequent land surface temperature (LST) determination (8 times a day) in the ISCCP database has allowed us to assess the diurnal cycle effect on emissivity retrieval. Differences in magnitude and phase between thermal temperature and low frequencies microwave brightness temperature have been noticed. These differences seem to vary in space and time. They also depend on soil texture and thermal inertia. The proposed methodology accounts for these factors and
DEFF Research Database (Denmark)
Pedersen, D. B.; Hansen, H. N.; Nielsen, J. S.
2014-01-01
The layered nature of Additive Manufactured parts, specifically those given from the Fused Deposition Modelling (FDM) process, exhibit a distinct surface definition. The origin of this is from the 2.5D deposition scheme, which leaves the seam between the individual layers clearly visible.[1...
International Nuclear Information System (INIS)
Chadderton, L.T.
1977-01-01
It is widely believed that the phenomenon responsible for the familiar peak in the angular dependence of sputtered yields also gives rise to characteristic semiangles α of conical protruberances on sputtered surfaces. It is shown that α corresponds to the process giving rise to the minimum rather than the maximum. No accurate measurements of the minimum have yet been made. (Auth.)
Airport surface moving map displays: OpEval-2 evaluation results and future plans
Livack, Garret; McDaniel, James I.; Battiste, Vernol
2001-08-01
The Federal Aviation Administration (FAA), in cooperation with the Cargo Airline Association (CAA) and three of its member airlines (Airborne Express, Federal Express, and United Parcel Service), have embarked upon an aggressive yet phased approach to introduce new Free Flight-enabling technologies into the U.S. National Airspace System (NAS). General aviation is also actively involved, represented primarily by the Aircraft Owners and Pilots Association (AOPA). These new technologies being evaluated include advanced cockpit avionics and a complimentary ground infrastructure. In support of this initiative, a series of operational evaluations (OpEvals) have been conducted or are planned. The OpEvals have evaluated in-flight as well as airport surface movement applications. Results from the second OpEval, conducted at Louisville, Kentucky in October 2000, indicated that runway incursions might be significantly reduced with the introduction of a cockpit-based moving map system derived from emerging technologies. An additional OpEval is planned to evaluate the utility of an integrated cockpit and airport surface architecture that provides enhanced pilot and controller awareness of airport surface operations. It is believed that the combination of such an airborne and a ground-based system best addresses many of the safety issues surrounding airport surface operations. Such a combined system would provide both flight crews and controllers with a common awareness, or shared picture of airport surface operations.
Mapping Global Ocean Surface Albedo from Satellite Observations: Models, Algorithms, and Datasets
Li, X.; Fan, X.; Yan, H.; Li, A.; Wang, M.; Qu, Y.
2018-04-01
Ocean surface albedo (OSA) is one of the important parameters in surface radiation budget (SRB). It is usually considered as a controlling factor of the heat exchange among the atmosphere and ocean. The temporal and spatial dynamics of OSA determine the energy absorption of upper level ocean water, and have influences on the oceanic currents, atmospheric circulations, and transportation of material and energy of hydrosphere. Therefore, various parameterizations and models have been developed for describing the dynamics of OSA. However, it has been demonstrated that the currently available OSA datasets cannot full fill the requirement of global climate change studies. In this study, we present a literature review on mapping global OSA from satellite observations. The models (parameterizations, the coupled ocean-atmosphere radiative transfer (COART), and the three component ocean water albedo (TCOWA)), algorithms (the estimation method based on reanalysis data, and the direct-estimation algorithm), and datasets (the cloud, albedo and radiation (CLARA) surface albedo product, dataset derived by the TCOWA model, and the global land surface satellite (GLASS) phase-2 surface broadband albedo product) of OSA have been discussed, separately.
Mapping Impervious Surfaces Globally at 30m Resolution Using Landsat Global Land Survey Data
Brown de Colstoun, E.; Huang, C.; Wolfe, R. E.; Tan, B.; Tilton, J.; Smith, S.; Phillips, J.; Wang, P.; Ling, P.; Zhan, J.; Xu, X.; Taylor, M. P.
2013-12-01
Impervious surfaces, mainly artificial structures and roads, cover less than 1% of the world's land surface (1.3% over USA). Regardless of the relatively small coverage, impervious surfaces have a significant impact on the environment. They are the main source of the urban heat island effect, and affect not only the energy balance, but also hydrology and carbon cycling, and both land and aquatic ecosystem services. In the last several decades, the pace of converting natural land surface to impervious surfaces has increased. Quantitatively monitoring the growth of impervious surface expansion and associated urbanization has become a priority topic across both the physical and social sciences. The recent availability of consistent, global scale data sets at 30m resolution such as the Global Land Survey from the Landsat satellites provides an unprecedented opportunity to map global impervious cover and urbanization at this resolution for the first time, with unprecedented detail and accuracy. Moreover, the spatial resolution of Landsat is absolutely essential to accurately resolve urban targets such a buildings, roads and parking lots. With long term GLS data now available for the 1975, 1990, 2000, 2005 and 2010 time periods, the land cover/use changes due to urbanization can now be quantified at this spatial scale as well. In the Global Land Survey - Imperviousness Mapping Project (GLS-IMP), we are producing the first global 30 m spatial resolution impervious cover data set. We have processed the GLS 2010 data set to surface reflectance (8500+ TM and ETM+ scenes) and are using a supervised classification method using a regression tree to produce continental scale impervious cover data sets. A very large set of accurate training samples is the key to the supervised classifications and is being derived through the interpretation of high spatial resolution (~2 m or less) commercial satellite data (Quickbird and Worldview2) available to us through the unclassified
A new method for automated discontinuity trace mapping on rock mass 3D surface model
Li, Xiaojun; Chen, Jianqin; Zhu, Hehua
2016-04-01
This paper presents an automated discontinuity trace mapping method on a 3D surface model of rock mass. Feature points of discontinuity traces are first detected using the Normal Tensor Voting Theory, which is robust to noisy point cloud data. Discontinuity traces are then extracted from feature points in four steps: (1) trace feature point grouping, (2) trace segment growth, (3) trace segment connection, and (4) redundant trace segment removal. A sensitivity analysis is conducted to identify optimal values for the parameters used in the proposed method. The optimal triangular mesh element size is between 5 cm and 6 cm; the angle threshold in the trace segment growth step is between 70° and 90°; the angle threshold in the trace segment connection step is between 50° and 70°, and the distance threshold should be at least 15 times the mean triangular mesh element size. The method is applied to the excavation face trace mapping of a drill-and-blast tunnel. The results show that the proposed discontinuity trace mapping method is fast and effective and could be used as a supplement to traditional direct measurement of discontinuity traces.
Agriculture pest and disease risk maps considering MSG satellite data and land surface temperature
Marques da Silva, J. R.; Damásio, C. V.; Sousa, A. M. O.; Bugalho, L.; Pessanha, L.; Quaresma, P.
2015-06-01
Pest risk maps for agricultural use are usually constructed from data obtained from in-situ meteorological weather stations, which are relatively sparsely distributed and are often quite expensive to install and difficult to maintain. This leads to the creation of maps with relatively low spatial resolution, which are very much dependent on interpolation methodologies. Considering that agricultural applications typically require a more detailed scale analysis than has traditionally been available, remote sensing technology can offer better monitoring at increasing spatial and temporal resolutions, thereby, improving pest management results and reducing costs. This article uses ground temperature, or land surface temperature (LST), data distributed by EUMETSAT/LSASAF (with a spatial resolution of 3 × 3 km (nadir resolution) and a revisiting time of 15 min) to generate one of the most commonly used parameters in pest modeling and monitoring: "thermal integral over air temperature (accumulated degree-days)". The results show a clear association between the accumulated LST values over a threshold and the accumulated values computed from meteorological stations over the same threshold (specific to a particular tomato pest). The results are very promising and enable the production of risk maps for agricultural pests with a degree of spatial and temporal detail that is difficult to achieve using in-situ meteorological stations.
Descriptive Characteristics of Surface Water Quality in Hong Kong by a Self-Organising Map
Directory of Open Access Journals (Sweden)
Yan An
2016-01-01
Full Text Available In this study, principal component analysis (PCA and a self-organising map (SOM were used to analyse a complex dataset obtained from the river water monitoring stations in the Tolo Harbor and Channel Water Control Zone (Hong Kong, covering the period of 2009–2011. PCA was initially applied to identify the principal components (PCs among the nonlinear and complex surface water quality parameters. SOM followed PCA, and was implemented to analyze the complex relationships and behaviors of the parameters. The results reveal that PCA reduced the multidimensional parameters to four significant PCs which are combinations of the original ones. The positive and inverse relationships of the parameters were shown explicitly by pattern analysis in the component planes. It was found that PCA and SOM are efficient tools to capture and analyze the behavior of multivariable, complex, and nonlinear related surface water quality data.
Descriptive Characteristics of Surface Water Quality in Hong Kong by a Self-Organising Map.
An, Yan; Zou, Zhihong; Li, Ranran
2016-01-08
In this study, principal component analysis (PCA) and a self-organising map (SOM) were used to analyse a complex dataset obtained from the river water monitoring stations in the Tolo Harbor and Channel Water Control Zone (Hong Kong), covering the period of 2009-2011. PCA was initially applied to identify the principal components (PCs) among the nonlinear and complex surface water quality parameters. SOM followed PCA, and was implemented to analyze the complex relationships and behaviors of the parameters. The results reveal that PCA reduced the multidimensional parameters to four significant PCs which are combinations of the original ones. The positive and inverse relationships of the parameters were shown explicitly by pattern analysis in the component planes. It was found that PCA and SOM are efficient tools to capture and analyze the behavior of multivariable, complex, and nonlinear related surface water quality data.
Energy Technology Data Exchange (ETDEWEB)
Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E. [Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)
2014-06-15
An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label.
Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E.
2014-06-01
An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label.
International Nuclear Information System (INIS)
Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E.
2014-01-01
An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label
Finn, S.; Liberty, L. M.; Haeussler, P. J.; Northrup, C.; Pratt, T. L.
2010-12-01
We interpret regionally extensive, active faults beneath Prince William Sound (PWS), Alaska, to be structurally linked to deeper megathrust splay faults, such as the one that ruptured in the 1964 M9.2 earthquake. Western PWS in particular is unique; the locations of active faulting offer insights into the transition at the southern terminus of the previously subducted Yakutat slab to Pacific plate subduction. Newly acquired high-resolution, marine seismic data show three seismic facies related to Holocene and older Quaternary to Tertiary strata. These sediments are cut by numerous high angle normal faults in the hanging wall of megathrust splay. Crustal-scale seismic reflection profiles show splay faults emerging from 20 km depth between the Yakutat block and North American crust and surfacing as the Hanning Bay and Patton Bay faults. A distinct boundary coinciding beneath the Hinchinbrook Entrance causes a systematic fault trend change from N30E in southwestern PWS to N70E in northeastern PWS. The fault trend change underneath Hinchinbrook Entrance may occur gradually or abruptly and there is evidence for similar deformation near the Montague Strait Entrance. Landward of surface expressions of the splay fault, we observe subsidence, faulting, and landslides that record deformation associated with the 1964 and older megathrust earthquakes. Surface exposures of Tertiary rocks throughout PWS along with new apatite-helium dates suggest long-term and regional uplift with localized, fault-controlled subsidence.
International Nuclear Information System (INIS)
Landman, U.
1984-01-01
Since the beginning of this project, our group has been involved in theoretical studies of surface phenomena and processes, aimed toward increasing our understanding of fundamental processes which govern the properties of material surfaces. Our studies cover a wide spectrum of surface phenomena: surface reactivity, surface crystallography, electronic and vibrational structure, dynamical processes, phase transformations and phase change, the properties of interfaces and investigations of material processing and novel materials preparation techniques. In these investigations we develop and employ analytical and novel numerical, simulation, methods for the study of complex surface phenomena. Our recent surface molecular dynamics studies and simulations of laser annealing phenomena opened new avenues for the investigation of the microscopic dynamics and evolution of equilibrium and non-equilibrium processes at surfaces and interfaces. Our current studies of metallic glasses using a new langrangian formulation which includes all components of the total energy (density dependent electron gas, single particle and pair interactions) of the system, represents a novel approach for theoretical studies of this important class of systems
Vasilkov, Alexander; Qin, Wenhan; Krotkov, Nickolay; Lamsal, Lok; Spurr, Robert; Haffner, David; Joiner, Joanna; Yang, Eun-Su; Marchenko, Sergey
2017-01-01
Most satellite nadir ultraviolet and visible cloud, aerosol, and trace-gas algorithms make use of climatological surface reflectivity databases. For example, cloud and NO2 retrievals for the Ozone Monitoring Instrument (OMI) use monthly gridded surface reflectivity climatologies that do not depend upon the observation geometry. In reality, reflection of incoming direct and diffuse solar light from land or ocean surfaces is sensitive to the sun-sensor geometry. This dependence is described by the bidirectional reflectance distribution function (BRDF). To account for the BRDF, we propose to use a new concept of geometry-dependent Lambertian equivalent reflectivity (LER). Implementation within the existing OMI cloud and NO2 retrieval infrastructure requires changes only to the input surface reflectivity database. The geometry-dependent LER is calculated using a vector radiative transfer model with high spatial resolution BRDF information from the Moderate Resolution Imaging Spectroradiometer (MODIS) over land and the Cox-Munk slope distribution over ocean with a contribution from water-leaving radiance. We compare the geometry-dependent and climatological LERs for two wavelengths, 354 and 466 nm, that are used in OMI cloud algorithms to derive cloud fractions. A detailed comparison of the cloud fractions and pressures derived with climatological and geometry-dependent LERs is carried out. Geometry-dependent LER and corresponding retrieved cloud products are then used as inputs to our OMI NO2 algorithm. We find that replacing the climatological OMI-based LERs with geometry-dependent LERs can increase NO2 vertical columns by up to 50% in highly polluted areas; the differences include both BRDF effects and biases between the MODIS and OMI-based surface reflectance data sets. Only minor changes to NO2 columns (within 5 %) are found over unpolluted and overcast areas.
Vasilkov, Alexander; Qin, Wenhan; Krotkov, Nickolay; Lamsal, Lok; Spurr, Robert; Haffner, David; Joiner, Joanna; Yang, Eun-Su; Marchenko, Sergey
2017-01-01
Most satellite nadir ultraviolet and visible cloud, aerosol, and trace-gas algorithms make use of climatological surface reflectivity databases. For example, cloud and NO2 retrievals for the Ozone Monitoring Instrument (OMI) use monthly gridded surface reflectivity climatologies that do not depend upon the observation geometry. In reality, reflection of incoming direct and diffuse solar light from land or ocean surfaces is sensitive to the sun-sensor geometry. This dependence is described by the bidirectional reflectance distribution function (BRDF). To account for the BRDF, we propose to use a new concept of geometry-dependent Lambertian equivalent reflectivity (LER). Implementation within the existing OMI cloud and NO2 retrieval infrastructure requires changes only to the input surface reflectivity database. The geometry-dependent LER is calculated using a vector radiative transfer model with high spatial resolution BRDF information from the Moderate Resolution Imaging Spectroradiometer (MODIS) over land and the Cox-Munk slope distribution over ocean with a contribution from water-leaving radiance. We compare the geometry-dependent and climatological LERs for two wavelengths, 354 and 466 nm, that are used in OMI cloud algorithms to derive cloud fractions. A detailed comparison of the cloud fractions and pressures derived with climatological and geometry-dependent LERs is carried out. Geometry-dependent LER and corresponding retrieved cloud products are then used as inputs to our OMI NO2 algorithm. We find that replacing the climatological OMI-based LERs with geometry-dependent LERs can increase NO2 vertical columns by up to 50 % in highly polluted areas; the differences include both BRDF effects and biases between the MODIS and OMI-based surface reflectance data sets. Only minor changes to NO2 columns (within 5 %) are found over unpolluted and overcast areas.
Petersen, Peter
2016-01-01
Intended for a one year course, this text serves as a single source, introducing readers to the important techniques and theorems, while also containing enough background on advanced topics to appeal to those students wishing to specialize in Riemannian geometry. This is one of the few Works to combine both the geometric parts of Riemannian geometry and the analytic aspects of the theory. The book will appeal to a readership that have a basic knowledge of standard manifold theory, including tensors, forms, and Lie groups. Important revisions to the third edition include: a substantial addition of unique and enriching exercises scattered throughout the text; inclusion of an increased number of coordinate calculations of connection and curvature; addition of general formulas for curvature on Lie Groups and submersions; integration of variational calculus into the text allowing for an early treatment of the Sphere theorem using a proof by Berger; incorporation of several recent results about manifolds with posit...
International Nuclear Information System (INIS)
Strominger, A.
1990-01-01
A special manifold is an allowed target manifold for the vector multiplets of D=4, N=2 supergravity. These manifolds are of interest for string theory because the moduli spaces of Calabi-Yau threefolds and c=9, (2,2) conformal field theories are special. Previous work has given a local, coordinate-dependent characterization of special geometry. A global description of special geometries is given herein, and their properties are studied. A special manifold M of complex dimension n is characterized by the existence of a holomorphic Sp(2n+2,R)xGL(1,C) vector bundle over M with a nowhere-vanishing holomorphic section Ω. The Kaehler potential on M is the logarithm of the Sp(2n+2,R) invariant norm of Ω. (orig.)
A Surface Soil Radioactivity Mapping Has Been Carried Out at Muria Peninsula, Central Java
International Nuclear Information System (INIS)
Soepradto-Tjokrokardono; Nasrun-Syamsul; Supardjo-AS; Djodi-R-Mappa; Kurnia-Setyawan W
2004-01-01
The air of this mapping is to gain exposure dose value of the soil surface of Muria Peninsula. Central Java, in the area of 75 km radius from Ujung Lemah Abang. Lemah Abang is the proposed site of the first indonesian nuclear Power Plant. A radioactivity data obtained in 1995/1996 to 1998/1999 researches has been used for input data. For further analysis, a conversation factor multiplication is applied. This conversation factor is obtained from linear regression equation of the relationship between radioactivity and exposure values gained from re-measured randomly 44 points which are representative for high, medium, and low radiation areas obtained in 1995/1996 to 1998/1999 activities and it taking soil samples. The conversation data result is being constructed of the Surface Exposure Dose Map of Muria Peninsula. Those data show that the exposure dose of northern slope of Muria Volcano is relatively higher than that of southern slope, it means be harmonizing to the soil sample radioactivity values. The maximum radioactivity value of the soil samples is 3,56.10 -2 Bq/gram (α radiation), 8,22.10 -1 Bq/gram (β radiation) and 6,20.10 -1 Bq/gram (γ radiation) and the minimum values are 4,44 10 -3 Bq/gram (α radiation), 1,50. 10 -1 Bq/gram (β radiation) and 4,09. 10 -2 Bq/gram (γ radiation). (author)
A new capture fraction method to map how pumpage affects surface water flow
Leake, S.A.; Reeves, H.W.; Dickinson, J.E.
2010-01-01
All groundwater pumped is balanced by removal of water somewhere, initially from storage in the aquifer and later from capture in the form of increase in recharge and decrease in discharge. Capture that results in a loss of water in streams, rivers, and wetlands now is a concern in many parts of the United States. Hydrologists commonly use analytical and numerical approaches to study temporal variations in sources of water to wells for select points of interest. Much can be learned about coupled surface/groundwater systems, however, by looking at the spatial distribution of theoretical capture for select times of interest. Development of maps of capture requires (1) a reasonably well-constructed transient or steady state model of an aquifer with head-dependent flow boundaries representing surface water features or evapotranspiration and (2) an automated procedure to run the model repeatedly and extract results, each time with a well in a different location. This paper presents new methods for simulating and mapping capture using three-dimensional groundwater flow models and presents examples from Arizona, Oregon, and Michigan. Journal compilation ?? 2010 National Ground Water Association. No claim to original US government works.
Pardo-Montero, Juan; Fenwick, John D
2010-06-01
comprising two regions: One where the dose to the target is close to prescription and trade-offs can be made between doses to the organs at risk and (small) changes in target dose, and one where very substantial rectal sparing is achieved at the cost of large target underdosage. Plans computed following the approach using a conformal arc and four blocked arcs generally lie close to the Pareto front, although distances of some plans from high gradient regions of the Pareto front can be greater. Only around 12% of plans lie a relative Euclidean distance of 0.15 or greater from the Pareto front. Using the alternative distance measure of Craft ["Calculating and controlling the error of discrete representations of Pareto surfaces in convex multi-criteria optimization," Phys. Medica (to be published)], around 2/5 of plans lie more than 0.05 from the front. Computation of blocked arcs is quite fast, the algorithms requiring 35%-80% of the running time per iteration needed for conventional inverse plan computation. The geometry-based arc approach to multicriteria optimization of rotational therapy allows solutions to be obtained that lie close to the Pareto front. Both the image-reconstruction type and gradient-descent algorithms produce similar modulated arcs, the latter one perhaps being preferred because it is more easily implementable in standard treatment planning systems. Moderate unblocking provides a good way of dealing with OARs which abut the PTV. Optimization of geometry-based arcs is faster than usual inverse optimization of treatment plans, making this approach more rapid than an inverse-based Pareto front reconstruction.
Shearer, Melinda J.
2018-02-01
Nanomaterials are interesting for a variety of applications, such as optoelectronics and photovoltaics. However, they often have spatial heterogeneity, i.e. composition change or physical change in the topography or structure, which can lead to varying properties that would influence their applications. New techniques must be developed to understand and correlate spatial heterogeneity with changes in electronic properties. Here we highlight the technique of surface photovoltage-Kelvin probe force microscopy (SPV-KFM), which is a modified version of non-contact atomic force microscopy capable of imaging not only the topography and surface potential, but also the surface photovoltage on the nanoscale. We demonstrate its utility in probing monolayer WSe2-MoS2 lateral heterostructures, which form an ultrathin p-n junction promising for photovoltaic and optoelectronic applications. We show surface photovoltage maps highlighting the different photoresponse of the two material regions as a result of the effective charge separation across this junction. Additionally, we study the variations between different heterostructure flakes and emphasize the importance of controlling the synthesis and transfer of these materials to obtain consistent properties and measurements.
Magnetic surface mapping with highly transparent screens on the Auburn Torsatron
International Nuclear Information System (INIS)
Hartwell, G.J.; Gandy, R.F.; Henderson, M.A.; Hanson, J.D.; Swanson, D.G.; Bush, C.J.; Colchin, R.J.; England, A.C.; Lee, D.K.
1987-01-01
In stellarator-type magnetic confinement devices (of which the torsatron is one), the magnetic field is produced entirely by external, current-carrying coils. Two methods for mapping magnetic surfaces in the Auburn Torsatron were tested and compared, both of which involve the use of highly transparent screens. The first method consists of coating the screen with a phosphor that emits light when struck by electrons emitted by an electron gun. A pattern representative of a magnetic surface is formed on the screen, and this pattern is recorded photographically. The second method uses an uncoated screen to collect electrons emitted from an emissive probe, which is scanned over a poloidal cross section of the torus. Under certain conditions, the collected current is a constant over a particular magnetic surface so that a contour plot of the current versus position is equivalent to a plot of the magnetic surfaces. Parametric studies of the two methods are presented, and the effectiveness of each technique is discussed
Shearer, Melinda J.; Li, Ming-yang; Li, Lain-Jong; Jin, Song; Hamers, Robert J
2018-01-01
Nanomaterials are interesting for a variety of applications, such as optoelectronics and photovoltaics. However, they often have spatial heterogeneity, i.e. composition change or physical change in the topography or structure, which can lead to varying properties that would influence their applications. New techniques must be developed to understand and correlate spatial heterogeneity with changes in electronic properties. Here we highlight the technique of surface photovoltage-Kelvin probe force microscopy (SPV-KFM), which is a modified version of non-contact atomic force microscopy capable of imaging not only the topography and surface potential, but also the surface photovoltage on the nanoscale. We demonstrate its utility in probing monolayer WSe2-MoS2 lateral heterostructures, which form an ultrathin p-n junction promising for photovoltaic and optoelectronic applications. We show surface photovoltage maps highlighting the different photoresponse of the two material regions as a result of the effective charge separation across this junction. Additionally, we study the variations between different heterostructure flakes and emphasize the importance of controlling the synthesis and transfer of these materials to obtain consistent properties and measurements.
General Geometry and Geometry of Electromagnetism
Shahverdiyev, Shervgi S.
2002-01-01
It is shown that Electromagnetism creates geometry different from Riemannian geometry. General geometry including Riemannian geometry as a special case is constructed. It is proven that the most simplest special case of General Geometry is geometry underlying Electromagnetism. Action for electromagnetic field and Maxwell equations are derived from curvature function of geometry underlying Electromagnetism. And it is shown that equation of motion for a particle interacting with electromagnetic...
The effect of TWD estimation error on the geometry of machined surfaces in micro-EDM milling
DEFF Research Database (Denmark)
Puthumana, Govindan; Bissacco, Giuliano; Hansen, Hans Nørgaard
In micro EDM (electrical discharge machining) milling, tool electrode wear must be effectively compensated in order to achieve high accuracy of machined features [1]. Tool wear compensation in micro-EDM milling can be based on off-line techniques with limited accuracy such as estimation...... and statistical characterization of the discharge population [3]. The TWD based approach permits the direct control of the position of the tool electrode front surface. However, TWD estimation errors will generate a self-amplifying error on the tool electrode axial depth during micro-EDM milling. Therefore....... The error propagation effect is demonstrated through a software simulation tool developed by the authors for determination of the correct TWD for subsequent use in compensation of electrode wear in EDM milling. The implemented model uses an initial arbitrary estimation of TWD and a single experiment...
Energy Technology Data Exchange (ETDEWEB)
Zhang, K. F.; Yang, Fang; Song, Y. R. [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang, Xiaole [Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240 (China); The State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Chen, Xianfeng [The State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Canhua; Qian, Dong; Gao, C. L., E-mail: clgao@sjtu.edu.cn; Jia, Jin-Feng [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing (China); Luo, Weidong, E-mail: wdluo@sjtu.edu.cn [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing (China)
2016-02-08
Antiferromagnetic semiconductors gain increasing interest due to their possible application in spintronics. Using spin polarized scanning tunneling microscopy operating in a vector field, we mapped the noncollinear antiferromagnetic spin structure of a semiconducting hexagonal FeSe surface on the atomic scale. The surface possesses an in-plane compensated Néel structure which is further confirmed by first-principles calculations.
International Nuclear Information System (INIS)
Zhang, K. F.; Yang, Fang; Song, Y. R.; Zhang, Xiaole; Chen, Xianfeng; Liu, Canhua; Qian, Dong; Gao, C. L.; Jia, Jin-Feng; Luo, Weidong
2016-01-01
Antiferromagnetic semiconductors gain increasing interest due to their possible application in spintronics. Using spin polarized scanning tunneling microscopy operating in a vector field, we mapped the noncollinear antiferromagnetic spin structure of a semiconducting hexagonal FeSe surface on the atomic scale. The surface possesses an in-plane compensated Néel structure which is further confirmed by first-principles calculations
Surface density mapping of natural tissue by a scanning haptic microscope (SHM).
Moriwaki, Takeshi; Oie, Tomonori; Takamizawa, Keiichi; Murayama, Yoshinobu; Fukuda, Toru; Omata, Sadao; Nakayama, Yasuhide
2013-02-01
To expand the performance capacity of the scanning haptic microscope (SHM) beyond surface mapping microscopy of elastic modulus or topography, surface density mapping of a natural tissue was performed by applying a measurement theory of SHM, in which a frequency change occurs upon contact of the sample surface with the SHM sensor - a microtactile sensor (MTS) that vibrates at a pre-determined constant oscillation frequency. This change was mainly stiffness-dependent at a low oscillation frequency and density-dependent at a high oscillation frequency. Two paragon examples with extremely different densities but similar macroscopic elastic moduli in the range of natural soft tissues were selected: one was agar hydrogels and the other silicon organogels with extremely low (less than 25 mg/cm(3)) and high densities (ca. 1300 mg/cm(3)), respectively. Measurements were performed in saline solution near the second-order resonance frequency, which led to the elastic modulus, and near the third-order resonance frequency. There was little difference in the frequency changes between the two resonance frequencies in agar gels. In contrast, in silicone gels, a large frequency change by MTS contact was observed near the third-order resonance frequency, indicating that the frequency change near the third-order resonance frequency reflected changes in both density and elastic modulus. Therefore, a density image of the canine aortic wall was subsequently obtained by subtracting the image observed near the second-order resonance frequency from that near the third-order resonance frequency. The elastin-rich region had a higher density than the collagen-rich region.
Directory of Open Access Journals (Sweden)
McCullagh Paul J
2005-09-01
Full Text Available Abstract Background In body surface potential mapping, increased spatial sampling is used to allow more accurate detection of a cardiac abnormality. Although diagnostically superior to more conventional electrocardiographic techniques, the perceived complexity of the Body Surface Potential Map (BSPM acquisition process has prohibited its acceptance in clinical practice. For this reason there is an interest in striking a compromise between the minimum number of electrocardiographic recording sites required to sample the maximum electrocardiographic information. Methods In the current study, several techniques widely used in the domains of data mining and knowledge discovery have been employed to mine for diagnostic information in 192 lead BSPMs. In particular, the Single Variable Classifier (SVC based filter and Sequential Forward Selection (SFS based wrapper approaches to feature selection have been implemented and evaluated. Using a set of recordings from 116 subjects, the diagnostic ability of subsets of 3, 6, 9, 12, 24 and 32 electrocardiographic recording sites have been evaluated based on their ability to correctly asses the presence or absence of Myocardial Infarction (MI. Results It was observed that the wrapper approach, using sequential forward selection and a 5 nearest neighbour classifier, was capable of choosing a set of 24 recording sites that could correctly classify 82.8% of BSPMs. Although the filter method performed slightly less favourably, the performance was comparable with a classification accuracy of 79.3%. In addition, experiments were conducted to show how (a features chosen using the wrapper approach were specific to the classifier used in the selection model, and (b lead subsets chosen were not necessarily unique. Conclusion It was concluded that both the filter and wrapper approaches adopted were suitable for guiding the choice of recording sites useful for determining the presence of MI. It should be noted however
An improved method for Multipath Hemispherical Map (MHM) based on Trend Surface Analysis
Wang, Zhiren; Chen, Wen; Dong, Danan; Yu, Chao
2017-04-01
Among various approaches developed for detecting the multipath effect in high-accuracy GNSS positioning, Only MHM (Multipath Hemispherical Map) and SF (Sidereal Filtering) can be implemented to real-time GNSS data processing. SF is based on the time repeatability of satellites which just suitable for static environment, while the spatiotemporal repeatability-based MHM is applicable not only for static environment but also for dynamic carriers with static multipath environment such as ships and airplanes, and utilizes much smaller number of parameters than ASF. However, the MHM method also has certain defects. Since the MHM take the mean of residuals from the grid as the filter value, it is more suitable when the multipath regime is medium to low frequency. Now existing research data indicate that the newly advanced Sidereal Filtering (ASF) method perform better with high frequency multipath reduction than MHM by contrast. To solve the above problem and improve MHM's performance on high frequency multipath, we combined binary trend surface analysis method with original MHM model to effectively analyze particular spatial distribution and variation trends of multipath effect. We computed trend surfaces of the residuals within a grid by least-square procedures, and chose the best results through the moderate successive test. The enhanced MHM grid was constructed from a set of coefficients of the fitted equation instead of mean value. According to the analysis of the actual observation, the improved MHM model shows positive effect on high frequency multipath reduction, and significantly reduced the root mean square (RMS) value of the carrier residuals. Keywords: Trend Surface Analysis; Multipath Hemispherical Map; high frequency multipath effect
On organizing principles of discrete differential geometry. Geometry of spheres
International Nuclear Information System (INIS)
Bobenko, Alexander I; Suris, Yury B
2007-01-01
Discrete differential geometry aims to develop discrete equivalents of the geometric notions and methods of classical differential geometry. This survey contains a discussion of the following two fundamental discretization principles: the transformation group principle (smooth geometric objects and their discretizations are invariant with respect to the same transformation group) and the consistency principle (discretizations of smooth parametrized geometries can be extended to multidimensional consistent nets). The main concrete geometric problem treated here is discretization of curvature-line parametrized surfaces in Lie geometry. Systematic use of the discretization principles leads to a discretization of curvature-line parametrization which unifies circular and conical nets.
Zheng, Fangyang
2002-01-01
The theory of complex manifolds overlaps with several branches of mathematics, including differential geometry, algebraic geometry, several complex variables, global analysis, topology, algebraic number theory, and mathematical physics. Complex manifolds provide a rich class of geometric objects, for example the (common) zero locus of any generic set of complex polynomials is always a complex manifold. Yet complex manifolds behave differently than generic smooth manifolds; they are more coherent and fragile. The rich yet restrictive character of complex manifolds makes them a special and interesting object of study. This book is a self-contained graduate textbook that discusses the differential geometric aspects of complex manifolds. The first part contains standard materials from general topology, differentiable manifolds, and basic Riemannian geometry. The second part discusses complex manifolds and analytic varieties, sheaves and holomorphic vector bundles, and gives a brief account of the surface classifi...
EVALUATION MODEL FOR PAVEMENT SURFACE DISTRESS ON 3D POINT CLOUDS FROM MOBILE MAPPING SYSTEM
Directory of Open Access Journals (Sweden)
K. Aoki
2012-07-01
Full Text Available This paper proposes a methodology to evaluate the pavement surface distress for maintenance planning of road pavement using 3D point clouds from Mobile Mapping System (MMS. The issue on maintenance planning of road pavement requires scheduled rehabilitation activities for damaged pavement sections to keep high level of services. The importance of this performance-based infrastructure asset management on actual inspection data is globally recognized. Inspection methodology of road pavement surface, a semi-automatic measurement system utilizing inspection vehicles for measuring surface deterioration indexes, such as cracking, rutting and IRI, have already been introduced and capable of continuously archiving the pavement performance data. However, any scheduled inspection using automatic measurement vehicle needs much cost according to the instruments’ specification or inspection interval. Therefore, implementation of road maintenance work, especially for the local government, is difficult considering costeffectiveness. Based on this background, in this research, the methodologies for a simplified evaluation for pavement surface and assessment of damaged pavement section are proposed using 3D point clouds data to build urban 3D modelling. The simplified evaluation results of road surface were able to provide useful information for road administrator to find out the pavement section for a detailed examination and for an immediate repair work. In particular, the regularity of enumeration of 3D point clouds was evaluated using Chow-test and F-test model by extracting the section where the structural change of a coordinate value was remarkably achieved. Finally, the validity of the current methodology was investigated by conducting a case study dealing with the actual inspection data of the local roads.
Surface geometry of BaO on W(100): A surface-extended x-ray-absorption fine-structure study
International Nuclear Information System (INIS)
Shih, A.; Hor, C.; Elam, W.; Kirkland, J.; Mueller, D.
1991-01-01
A surface-extended x-ray-absorption fine-structure study of ordered monolayers of coadsorbed barium and oxygen on a single-crystal W(100) surface is described. A (√2 x √2 )R45 degree structure with a stoichiometric barium-to-oxygen ratio, and a (2 √2 x √2 )R45 degree structure with a nearly 1:2 barium-to-oxygen atomic ratio both form on W(100). The surface-extended x-ray-absorption fine-structure results indicate that all the barium and oxygen atoms are nearly coplanar in the (√2 x √2 )R45 degree overlayer. The Ba-to-O distance in this overlayer is 3.20 ±0.05 A and β=82 degree ±5 degree, where β is the angle between the Ba-O internuclear axis and the surface normal. For the (2 √2 x √2 )R45 degree overlayer, there are two types of oxygen sites. Oxygen atoms nearly coplanar with the barium atoms are also present in these films with a Ba-to-O distance of 3.27±0.05 A and β=75±4 degree. Additional oxygen atoms lie outside the barium plane at a distance 2.03±0.05 A and β=23±10 degree from the nearest barium atoms
Mapping the surface of Escherichia coli peptide deformylase by NMR with organic solvents.
Byerly, Douglas W; McElroy, Craig A; Foster, Mark P
2002-07-01
Identifying potential ligand binding sites on a protein surface is an important first step for targeted structure-based drug discovery. While performing control experiments with Escherichia coli peptide deformylase (PDF), we noted that the organic solvents used to solubilize some ligands perturbed many of the same resonances in PDF as the small molecule inhibitors. To further explore this observation, we recorded (15)N HSQC spectra of E. coli peptide deformylase (PDF) in the presence of trace quantities of several simple organic solvents (acetone, DMSO, ethanol, isopropanol) and identified their sites of interaction from local perturbation of amide chemical shifts. Analysis of the protein surface structure revealed that the ligand-induced shift perturbations map to the active site and one additional surface pocket. The correlation between sites of solvent and inhibitor binding highlights the utility of organic solvents to rapidly and effectively validate and characterize binding sites on proteins prior to designing a drug discovery screen. Further, the solvent-induced perturbations have implications for the use of organic solvents to dissolve candidate ligands in NMR-based screens.
International Nuclear Information System (INIS)
Castelaz, M.W.; Werner, M.W.; Sellgren, K.
1986-01-01
Surface brightness maps at 12, 25, 60, and 100 microns of 16 visible reflection nebulae were extracted from the Infrared Astronomy Satellite (IRAS) database. The maps were produced by coadding IRAS survey scans over areas centered on the illuminating stars, and have spatial resolutions of 0.9' x 4' at 12 and 25 microns, 1.8' x 4.5' at 60 microns, and 3.6' x 5' at 100 microns. Extended emission in the four IRAS bandpasses was detected in fourteen of the reflection nebulae. The IRAS data were used to measure the flux of the infrared emission associated with each source. The energy distributions show that the 12 micron flux is greater than the 25 micron flux in 11 of the nebulae, and the peak flux occurs in the 60 or 100 micron bandpass in all 16 nebular. The 60 and 100 micron flux can be approximated by blackbodies with temperatures between 30 and 50 K, consistent with temperatures expected from extrapolation of greybody fits to the 60 and 100 micron data. The excess 12 and 25 micron emission is attributed to a nonequilibrium process such as emission from thermal fluctuations of very small grains excited by single ultraviolet photons, or emission from polycyclic aromatic hydrocarbons (PAHs) excited by ultraviolet radiation. The common features of the energy distributions of the 16 reflection nebulae, also seen in the reflection nebulae associated with the Pleiades, suggest that PAHs or very small grains may be found in most reflection nebulae
Kwon, Joong-Ho; Bélanger, Jacqueline M R; Paré, J R Jocelyn
2003-03-26
Response surface methodology (RSM) was applied to predict optimum conditions for microwave-assisted extraction-a MAP technology-of saponin components from ginseng roots. A central composite design was used to monitor the effect of ethanol concentration (30-90%, X(1)) and extraction time (30-270 s, X(2)) on dependent variables, such as total extract yield (Y(1)), crude saponin content (Y(2)), and saponin ratio (Y(3)), under atmospheric pressure conditions when focused microwaves were applied at an emission frequency of 2450 MHz. In MAP under pre-established conditions, correlation coefficients (R (2)) of the models for total extract yield and crude saponin were 0.9841 (p extraction conditions were predicted for each variable as 52.6% ethanol and 224.7 s in extract yield and as 77.3% ethanol and 295.1 s in crude saponins, respectively. Estimated maximum values at predicted optimum conditions were in good agreement with experimental values.
Energy Technology Data Exchange (ETDEWEB)
Dosch, J
1991-12-31
The aim of this work is the development of a numerical process independent of the geometry of the flow space. The temperature, concentration and speed fields set up with double diffusive convection should be determined by this and their effect on heat transfer should be determined. The numerical process should be used for non-steady state double diffusive convection in various geometries. The results should be verified experimentally with the aid of holographic interferometry. (orig./IHL) [Deutsch] Ziel der vorliegenden Arbeit ist die Entwicklung eines von der Geometrie des Stroemungsraumes unabhaengigen numerischen Verfahrens. Mit ihm sollen die sich bei doppelt diffusiver Konvektion einstellenden Temperatur-, Konzentrations- und Geschwindigkeitsfelder bestimmt und deren Einfluss auf die Waermeuebertragung ermittelt werden. Das numerische Verfahren soll auf die instationaere doppelt diffusive Konvektion in verschiedenen Geometrien angewendet werden. Die Ergebnisse sollen experimentell mit Hilfe der holographischen Interferometrie verifiziert werden. (orig./IHL)
International Nuclear Information System (INIS)
Staggs, M.C.; Kozlowski, M.R.; Siekhaus, W.J.; Balooch, M.
1992-10-01
Atomic force microscopy (AFM) was used to determine in-situ the correlation between the surface dimensions of defects in dielectric multilayer optical coatings and their susceptibility to damage by pulsed laser illumination. The primary surface defects studied were μm-scale domes associated with the classic nodule defect. The optical film studied was a highly reflective dielectric multilayer consisting of pairs of alternating HfO 2 and SiO 2 layers of quarter wave thickness at 1.06 μm. Nodule defect height and width dimensions were measured prior to laser illumination on two different samples. Correlation between these dimensions supported a simple model for the defect geometry. Defects with high nodule heights (> 0.6 μm) were found to be most susceptible to laser damage over a range of fluences between 0-35 J/cm 2 (1.06 μm, 10 ns, and 1/e 2 diam. of 1.3 mm). Crater defects, formed by nodules ejected from the coating prior to illumination, were also studied. None of the crater defects damaged when illuminated over the same range of fluences that the nodule defects were subjected to
An introduction to differential geometry
Willmore, T J
2012-01-01
This text employs vector methods to explore the classical theory of curves and surfaces. Topics include basic theory of tensor algebra, tensor calculus, calculus of differential forms, and elements of Riemannian geometry. 1959 edition.
International Nuclear Information System (INIS)
Nakajima, T.; Kawakubo, K.; Toda, I.; Mashima, S.; Ohtake, T.; Iio, M.; Sugimoto, T.
1988-01-01
ST-T isointegral analysis of body surface mapping was used in an attempt to localize ischemic areas on exercise tests. In 28 patients with angina pectoris and 10 healthy subjects, body surface potential was recorded with 87 leads, and ST isopotential and ST-T isointegral maps were constructed. In all 10 healthy subjects, the basic pattern of the ST-T isointegral map showed no significant change after exercise. In 23 of 28 patients with angina pectoris (82%), alterations in the ST-T isointegral map after exercise were observed. They were divided into four types (anterior, inferoposterior, lateral, and global) according to the distribution of negative values, which were well correlated with the extent of ischemic area determined by thallium myocardial scintigraphy and coronary angiography. The postexercise ST-T isointegral map was normalized after administration of nitroglycerin in four of five patients. In five patients (18%) who did not show abnormalities on the postexercise ST-T isointegral map, the magnitude of maximal ST depression was significantly smaller than that observed in the other 23 patients with angina pectoris (0.14 vs 0.23 mV on the average, p less than 0.05). It was concluded that the exercise test with ST-T isointegral mapping is a new method for noninvasive detection of location and severity of ischemic regions
Drury, H. A.; Van Essen, D. C.; Anderson, C. H.; Lee, C. W.; Coogan, T. A.; Lewis, J. W.
1996-01-01
We present a new method for generating two-dimensional maps of the cerebral cortex. Our computerized, two-stage flattening method takes as its input any well-defined representation of a surface within the three-dimensional cortex. The first stage rapidly converts this surface to a topologically correct two-dimensional map, without regard for the amount of distortion introduced. The second stage reduces distortions using a multiresolution strategy that makes gross shape changes on a coarsely sampled map and further shape refinements on progressively finer resolution maps. We demonstrate the utility of this approach by creating flat maps of the entire cerebral cortex in the macaque monkey and by displaying various types of experimental data on such maps. We also introduce a surface-based coordinate system that has advantages over conventional stereotaxic coordinates and is relevant to studies of cortical organization in humans as well as non-human primates. Together, these methods provide an improved basis for quantitative studies of individual variability in cortical organization.
Anders, A. M.; Brandon, M. T.
2008-12-01
Available data indicate that large and persistent precipitation gradients are tied to topography at scales down to a few kilometers, but precipitation patterns in the majority of mountain ranges are poorly constrained at scales less than tens of kilometers. A lack of knowledge of precipitation patterns hampers efforts to understand the processes of orographic precipitation and identify the relationships between geomorphic evolution and climate. A new method for mapping precipitation using the stable isotopic composition of surface waters is tested in the Olympic Mountains of Washington State. Measured δD and δ18O of 97 samples of surface water are linearly related and nearly inseparable from the global meteoric water line. A linear orographic precipitation model extended to include in effects of isotopic fractionation via Rayleigh distillation predicts precipitation patterns and isotopic composition of surface water. Seven parameters relating to the climate and isotopic composition of source water are used. A constrained random search identifies the best-fitting parameter set. Confidence intervals for parameter values are defined and precipitation patterns are determined. Average errors for the best-fitting model are 4.8 permil in δD. The difference between the best fitting model and other models within the 95% confidence interval was less than 20%. An independent high-resolution precipitation climatology documents precipitation gradients similar in shape and magnitude to the model derived from surface water isotopic composition. This technique could be extended to other mountain ranges, providing an economical and fast assessment of precipitation patterns requiring minimal field work.
Kreutzer, Ingrid; Chwatal, Werner; Häusler, Hermann; Scheibz, Jürgen; Steirer, Fritz
2014-05-01
In the transition zone between the southern Vienna Basin and the Eisenstadt basin, close to Wr. Neustadt, spectacular fold structures are exposed in the former sand pit of Steinbrunn. The succession of Upper Pannonian age consists of decimetre to meter thick sandy, silty and clayey beds, which are overlain by sandstone beds (Grundtner et al., 2009). The anticline and syncline structures were interpreted as of gravitational origin by Exner et al. (2009), and reinterpreted as of tectonic origin by Häusler (2012a). In order to gain a more detailed insight to the three dimensional distribution and orientation of the folds high resolution geophysics such as electrical resistivity tomography (ERT), ground penetrating radar (GPR) and electromagnetics (EM) were applied to map the surroundings of the sandpit. The ERT- and EM-profiles show that the uppermost layer is more clayey northwest and sandier southeast of the sandpit. This is important for the GPR because clay attenuates the radar signals and therefore no clear layering of the subsurface could be mapped in these areas. In order to directly compare ERT and GPR results with the lithology of the fold structures observed in the sandpit, a reference profile on top of the 140 m long wall of the sandpit was performed. Both methods clearly reveal fold structures paralleling the folded Pannonian strata of the outcrop. While the GPR data displays boundaries and their geometry in the succession, the resistivities in the ERT portrays a more smoothened image of the observed fold structure. In almost all GPR profiles wavelike structures are visible with axes in northern direction and dome-shaped structures with axes in eastern direction, deepening towards the west. In conclusion this pattern is comparable to sections of rounded buckle folds. Although there are clayey areas wave-like and dome-like reflections can be followed in the GPR profiles over a distance of several hundred meters. This is confirmed by the ERT profiles
Guided asteroid deflection by kinetic impact: Mapping keyholes to an asteroid's surface
Chesley, S.; Farnocchia, D.
2014-07-01
range from around 1 for a porous, compressible body producing negligible ejecta, to 2 when the ejecta momentum matches the spacecraft momentum, and as high as 5--10 for rocky bodies that produce large, high-velocity ejecta fragments. If the impactor hits the centerpoint of a spherical asteroid the momentum of the escaping ejecta directly adds to the momentum of the impacting asteroid, but if the impact is oblique then the ejecta and spacecraft momenta are added to the asteroid in vector sum. This suggests the possibility that for a given intercept trajectory the asteroid deflection could include guidance by targeting an oblique impact that could steer the asteroid Δ V to a more optimal direction that is different from the relative velocity direction of the spacecraft. An oblique impact decreases the net Δ V magnitude, and yet could significantly increase the net deflection at the time of the threatening Earth encounter. We use asteroid (101955) Bennu, which is the target of the OSIRIS-REx asteroid sample return mission and which has a series of potential Earth impacts in the years from 2175--2196, as an example to demonstrate the effectiveness of the oblique impact. These future potential impacts will occur if the asteroid passes through one of a series of keyholes when the asteroid passes the Earth at roughly the lunar distance from the Earth in 2135. To study the Bennu deflection problem we simulate a hypervelocity spacecraft impact on Bennu in March 2021, after the OSIRIS-REx mission is complete. In our example, the spacecraft arrives from approximately the sunward direction, and targeting ahead or behind the center of the asteroid allows non-negligible transverse accelerations for modest values of β. A given impact location on the asteroid surface yields a given Δ V vector, and our approach starts by mapping the net Δ V components on the surface for an assumed value of β. Knowing the mapping from impact location to Δ V and also the mapping from Δ V to the
3D Surface Mapping of Capsule Fill-Tube Assemblies used in Laser-Driven Fusion Targets
Energy Technology Data Exchange (ETDEWEB)
Buice, E S; Alger, E T; Antipa, N A; Bhandarkar, S D; Biesiada, T A; Conder, A D; Dzenitis, E G; Flegel, M S; Hamza, A V; Heinbockel, C L; Horner, J; Johnson, M A; Kegelmeyer, L M; Meyer, J S; Montesanti, R C; Reynolds, J L; Taylor, J S; Wegner, P J
2011-02-18
This paper presents the development of a 3D surface mapping system used to measure the surface of a fusion target Capsule Fill-Tube Assembly (CFTA). The CFTA consists of a hollow Ge-doped plastic sphere, called a capsule, ranging in outer diameter between 2.2 mm and 2.6 mm and an attached 150 {micro}m diameter glass-core fill-tube that tapers down to a 10{micro} diameter at the capsule. The mapping system is an enabling technology to facilitate a quality assurance program and to archive 3D surface information of each capsule used in fusion ignition experiments that are currently being performed at the National Ignition Facility (NIF). The 3D Surface Mapping System is designed to locate and quantify surface features with a height of 50 nm and 300 nm in width or larger. Additionally, the system will be calibrated such that the 3D measured surface can be related to the capsule surface angular coordinate system to within 0.25 degree (1{sigma}), which corresponds to approximately 5 {micro}m linear error on the capsule surface.
3D Surface Mapping of Capsule Fill-Tube Assemblies used in Laser-Driven Fusion Targets
International Nuclear Information System (INIS)
Buice, E.S.; Alger, E.T.; Antipa, N.A.; Bhandarkar, S.D.; Biesiada, T.A.; Conder, A.D.; Dzenitis, E.G.; Flegel, M.S.; Hamza, A.V.; Heinbockel, C.L.; Horner, J.; Johnson, M.A.; Kegelmeyer, L.M.; Meyer, J.S.; Montesanti, R.C.; Reynolds, J.L.; Taylor, J.S.; Wegner, P.J.
2011-01-01
This paper presents the development of a 3D surface mapping system used to measure the surface of a fusion target Capsule Fill-Tube Assembly (CFTA). The CFTA consists of a hollow Ge-doped plastic sphere, called a capsule, ranging in outer diameter between 2.2 mm and 2.6 mm and an attached 150 (micro)m diameter glass-core fill-tube that tapers down to a 10(micro) diameter at the capsule. The mapping system is an enabling technology to facilitate a quality assurance program and to archive 3D surface information of each capsule used in fusion ignition experiments that are currently being performed at the National Ignition Facility (NIF). The 3D Surface Mapping System is designed to locate and quantify surface features with a height of 50 nm and 300 nm in width or larger. Additionally, the system will be calibrated such that the 3D measured surface can be related to the capsule surface angular coordinate system to within 0.25 degree (1σ), which corresponds to approximately 5 (micro)m linear error on the capsule surface.
In situ mapping of radionuclides in subsurface and surface soils: 1994 Summary report
International Nuclear Information System (INIS)
Schilk, A.J.; Hubbard, C.W.; Knopf, M.A.; Abel, K.H.
1995-04-01
Uranium production and support facilities at several DOE sites occasionally caused local contamination of some surface and subsurface soils. The thorough cleanup of these sites is a major public concern and a high priority for the US Department of Energy, but before any effective remedial protocols can be established, the three-dimensional distributions of target contaminants must be characterized. Traditional means of measuring radionuclide activities in soil are cumbersome, expensive, time-consuming, and often do not accurately reflect conditions over very large areas. New technologies must be developed, or existing ones improved, to allow cheaper, faster, and safer characterization of radionuclides in soils at these sites. The Pacific Northwest Laboratory (PNL) was tasked with adapting, developing, and demonstrating technologies to measure uranium in surface and subsurface soils. In partial completion of this effort, PNL developed an improved in situ gamma-ray spectrometry system to satisfy the technical requirements. This document summarizes fiscal-year 1994 efforts at PNL to fulfill requirements for TTP number-sign 321103 (project number-sign 19307). These requirements included (a) developing a user-friendly software package for reducing field-acquired gamma-ray spectra, (b) constructing an improved data-acquisition hardware system for use with high-purity germanium detectors, (c) ensuring readiness to conduct field mapping exercises as specified by the sponsor, (d) evaluating the in situ gamma-ray spectrometer for the determination of uranium depth distribution, and (e) documenting these efforts
Du, J.; Kimball, J. S.; Galantowicz, J. F.; Kim, S.; Chan, S.; Reichle, R. H.; Jones, L. A.; Watts, J. D.
2017-12-01
A method to monitor global land surface water (fw) inundation dynamics was developed by exploiting the enhanced fw sensitivity of L-band (1.4 GHz) passive microwave observations from the Soil Moisture Active Passive (SMAP) mission. The L-band fw (fwLBand) retrievals were derived using SMAP H-polarization brightness temperature (Tb) observations and predefined L-band reference microwave emissivities for water and land endmembers. Potential soil moisture and vegetation contributions to the microwave signal were represented from overlapping higher frequency Tb observations from AMSR2. The resulting fwLBand global record has high temporal sampling (1-3 days) and 36-km spatial resolution. The fwLBand annual averages corresponded favourably (R=0.84, pretrievals showed favourable classification accuracy for water (commission error 31.84%; omission error 28.08%) and land (commission error 0.82%; omission error 0.99%) and seasonal wet and dry periods when compared to independent water maps derived from Landsat-8 imagery. The new fwLBand algorithms and continuing SMAP and AMSR2 operations provide for near real-time, multi-scale monitoring of global surface water inundation dynamics, potentially benefiting hydrological monitoring, flood assessments, and global climate and carbon modeling.
High-Resolution Mapping of Urban Surface Water Using ZY-3 Multi-Spectral Imagery
Directory of Open Access Journals (Sweden)
Fangfang Yao
2015-09-01
Full Text Available Accurate information of urban surface water is important for assessing the role it plays in urban ecosystem services under the content of urbanization and climate change. However, high-resolution monitoring of urban water bodies using remote sensing remains a challenge because of the limitation of previous water indices and the dark building shadow effect. To address this problem, we proposed an automated urban water extraction method (UWEM which combines a new water index, together with a building shadow detection method. Firstly, we trained the parameters of UWEM using ZY-3 imagery of Qingdao, China. Then we verified the algorithm using five other sub-scenes (Aksu, Fuzhou, Hanyang, Huangpo and Huainan ZY-3 imagery. The performance was compared with that of the Normalized Difference Water Index (NDWI. Results indicated that UWEM performed significantly better at the sub-scenes with kappa coefficients improved by 7.87%, 32.35%, 12.64%, 29.72%, 14.29%, respectively, and total omission and commission error reduced by 61.53%, 65.74%, 83.51%, 82.44%, and 74.40%, respectively. Furthermore, UWEM has more stable performances than NDWI’s in a range of thresholds near zero. It reduces the over- and under-estimation issues which often accompany previous water indices when mapping urban surface water under complex environmental conditions.
Laser electro-optic system for rapid three-dimensional /3-D/ topographic mapping of surfaces
Altschuler, M. D.; Altschuler, B. R.; Taboada, J.
1981-01-01
It is pointed out that the generic utility of a robot in a factory/assembly environment could be substantially enhanced by providing a vision capability to the robot. A standard videocamera for robot vision provides a two-dimensional image which contains insufficient information for a detailed three-dimensional reconstruction of an object. Approaches which supply the additional information needed for the three-dimensional mapping of objects with complex surface shapes are briefly considered and a description is presented of a laser-based system which can provide three-dimensional vision to a robot. The system consists of a laser beam array generator, an optical image recorder, and software for controlling the required operations. The projection of a laser beam array onto a surface produces a dot pattern image which is viewed from one or more suitable perspectives. Attention is given to the mathematical method employed, the space coding technique, the approaches used for obtaining the transformation parameters, the optics for laser beam array generation, the hardware for beam array coding, and aspects of image acquisition.
Energy Technology Data Exchange (ETDEWEB)
Groll, Nickolas; Pellin, Michael J. [Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States); Zasadzinksi, John F. [Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Proslier, Thomas, E-mail: prolier@anl.gov [Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States); High Energy Physics Division, Argonne National Laboratory, Lemont, Illinois 60439 (United States)
2015-09-15
We describe the design and testing of a point contact tunneling spectroscopy device that can measure material surface superconducting properties (i.e., the superconducting gap Δ and the critical temperature T{sub C}) and density of states over large surface areas with size up to mm{sup 2}. The tip lateral (X,Y) motion, mounted on a (X,Y,Z) piezo-stage, was calibrated on a patterned substrate consisting of Nb lines sputtered on a gold film using both normal (Al) and superconducting (PbSn) tips at 1.5 K. The tip vertical (Z) motion control enables some adjustment of the tip-sample junction resistance that can be measured over 7 orders of magnitudes from a quasi-ohmic regime (few hundred Ω) to the tunnel regime (from tens of kΩ up to few GΩ). The low noise electronic and LabVIEW program interface are also presented. The point contact regime and the large-scale motion capabilities are of particular interest for mapping and testing the superconducting properties of macroscopic scale superconductor-based devices.
International Nuclear Information System (INIS)
Morgan, M.A.
1989-07-01
Potential energy surfaces for photorotamerization of two intramolecularly hydrogen-bonded molecules, o-hydroxybenzaldehyde (OHBA) and methyl salicylate (MS), isolated in cryogenic matrices have been spectroscopically mapped. In addition, the external heavy atom effect of krypton and xenon matrices on the coupling between the S 1 and T 1 surfaces of 4-(dimethylamino)benzonitrile has been examined. Heavy atom matrices are known to increase rates of spin-forbidden processes. The phosphorescence intensity of DMABN increases in krypton and xenon matrices, while the fluorescence intensity, and phosphorescence and fluorescence lifetimes, decrease. These effects are interpreted in terms of a model in which the phosphorescence rate constant increases 300-fold in xenon compared to argon, while the rate constants for intersystem crossing and nonradiative relaxation from the triplet state increase by factors of less than 5. Lifetime measurements in argon matrices doped with heavy atoms indicate that even one heavy atom neighbor has a significant effect on both singlet and triplet lifetimes. 78 refs., 35 figs., 15 tabs
Estimating surface soil erosion losses and mapping erosion risk for Yusufeli micro-catchment (Artvin
Directory of Open Access Journals (Sweden)
Mustafa Tüfekçioğlu
2016-10-01
Full Text Available Sheet erosion, one of the most important types of water erosion, takes place on the top soil as tiny soil layer movement that affects lake and stream ecosystem. This type of erosion is very important because the productive soil layer on the top soil can be lost in a very short period of time. The goal of this study was to quantify the amount of surface (sheet and rill soil erosion, and to identify areas under high erosion risk within the study area at Yusufeli province in Artvin by using RUSLE erosion methodology. As a result of the study it was found that the average annual potential soil loss by surface erosion was 3.6 ton ha-1yr-1. Additionally, the maps produced and conclusions reached by the study revealed that the areas of high erosion risk were identified spatially and measures to control erosion on some of these high risk areas can be possible with appropriate erosion control techniques.
International Nuclear Information System (INIS)
Yan Shi-Chao; Xie Nan; Gong Hui-Qi; Guo Yang; Shan Xin-Yan; Lu Xing-Hua; Sun Qian
2012-01-01
The adsorption and diffusion behaviors of benzene molecules on an Au(111) surface are investigated by low-temperature scanning tunneling microscopy. A herringbone surface reconstruction of the Au(111) surface is imaged with atomic resolution, and significantly different behaviors are observed for benzene molecules adsorbed on step edges and terraces. The electric field induced modification in the molecular diffusion potential is revealed with a 2D molecular gas model, and a new method is developed to map the diffusion potential over the reconstructed Au(111) surface at the nanometer scale. (condensed matter: structure, mechanical and thermal properties)
Cumbrera, Ramiro; Millán, Humberto; Martín-Sotoca, Juan Jose; Pérez Soto, Luis; Sanchez, Maria Elena; Tarquis, Ana Maria
2016-04-01
methods for mapping geochemical anomalies caused by buried sources and for predicting undiscovered mineral deposits in covered areas. Journal of Geochemical Exploration, 122, 55-70. Cumbrera, R., Ana M. Tarquis, Gabriel Gascó, Humberto Millán (2012) Fractal scaling of apparent soil moisture estimated from vertical planes of Vertisol pit images. Journal of Hydrology (452-453), 205-212. Martin Sotoca; J.J. Antonio Saa-Requejo, Juan Grau and Ana M. Tarquis (2016). Segmentation of singularity maps in the context of soil porosity. Geophysical Research Abstracts, 18, EGU2016-11402. Millán, H., Cumbrera, R. and Ana M. Tarquis (2016) Multifractal and Levy-stable statistics of soil surface moisture distribution derived from 2D image analysis. Applied Mathematical Modelling, 40(3), 2384-2395.
Lazzari, M.; Loperte, A.; Perrone, A.
2009-04-01
This work, carried out with an integrated methodological approach, focuses on the use of near surface geophysics techniques, such as ground penetrating radar GPR and electrical resistivity tomography (ERT), and geomorphological analysis, in order to reconstruct the cave distribution and geometry in a urban context and, in particular, in historical centres. In fact, there are a lot of historical Mediterranean sites born on an original rupestrian settlement, of which often the new generations forgot the memory and new urban areas built on them burying any marks. The interaction during recent centuries between human activity (caves excavation, birth and growth of an urban area) and the characters of the natural environment were the reasons of a progressive increase in hazard and vulnerability levels of several sites. The reconstruction of a detailed cave map distribution is the first step to define the anthropic and geomorphological hazard in urban areas, fundamental basis for planning and assessing the risk. The integrated near surface geophysics and geomorphological techniques have been applied to the case study of Tursi hilltop town and its older nucleus called Rabatana, located in the south-western sector of the Basilicata (southern Italy), representing an interesting example of the deep bond between natural and man-made environments such as precious cultural heritage. The history of this settlement has always been deeply connected with the characteristics of the neighbouring environment and it seems possible that the first settlement was built by excavating the slopes of the sandy relief. It was a typical rupestrian settlement, where meteoric water was stored inside some cisterns excavated on the slopes. During recent centuries, the increase in territory development by humans produced an increase in cave excavation in the Tursi-Rabatana urban area. To reconstruct the extremely complex near-surface hypogeal environment excavated in the sandy layers, a geophysical
A surface plasmon resonance assay for characterisation and epitope mapping of anti-GLP-1 antibodies.
Thomsen, Lasse; Gurevich, Leonid
2018-04-19
The incretin hormone glucagon-like peptide-1 (GLP-1) has been subject to substantial pharmaceutical research regarding the treatment of type 2 diabetes mellitus. However, quantification of GLP-1 levels remains complicated due to the low circulation concentration and concurrent existence of numerous metabolites, homologous peptides, and potentially introduced GLP-1 receptor agonists. Surface plasmon resonance (SPR) facilitates real-time monitoring allowing a more detailed characterisation of the interaction compared with conventional enzyme-linked immunosorbent assays (ELISA). In this paper, we describe the development of the first SPR assays for characterisation of anti-GLP-1 antibodies for ELISA purposes. Binding responses were obtained on covalently immobilised anti-GLP-1 antibodies at 12°C, 25°C, and 40°C and fitted to a biomolecular (1:1) interaction model showing association rates of 1.01 × 10 3 to 4.54 × 10 3 M -1 s -1 and dissociation rates of 3.56 × 10 -5 to 1.56 × 10 -3 s -1 leading to affinities of 35.2 to 344 nM, depending on the temperature. Determination of thermodynamic properties revealed an enthalpy driven interaction (ΔH polar amino acids (ΔC p < 0). Pair-wise epitope mapping was performed on captured anti-GLP-1 antibodies followed by subsequent interaction with GLP-1 (7-36) and other anti-GLP-1 antibodies. A global evaluation of every binding response led to an epitope map elucidating the potential of various anti-GLP-1 antibody pairs for sandwich ELISA and hence pinpointing the optimal antibody combinations. The SPR assays proved capable of providing vital information for ELISA development endorsing it as a useful optimisation tool. Copyright © 2018 John Wiley & Sons, Ltd.
International Nuclear Information System (INIS)
Shum, D.K.; Bryson, J.W.; Merkle, J.G.
1993-09-01
This study presents preliminary estimates on whether an shallow, axially oriented, inner-surface finite-length flaw in a PWR-RPV would tend to elongate in the axial direction and/or deepen into the wall of the vessel during a postulated PTS transient. Analysis results obtained based on the assumptions of (1) linear-elastic material response, and (2) cladding with same toughness as the base metal, indicate that a nearly semicircular flaw would likely propagate in the axial direction followed by propagation into the wall of the vessel. Note that these results correspond to initiation within the lower-shelf fracture toughness temperature range, and that their general validity within the lower-transition temperature range remains to be determined. The sensitivity of the numerical results aid conclusions to the following analysis assumptions are evaluated: (1) reference flaw geometry along the entire crack front and especially within the cladding region; (2) linear-elastic vs elastic-plastic description of material response; and (3) base-material-only vs bimaterial cladding-base vessel-model assumption. The sensitivity evaluation indicates that the analysis results are very sensitive to the above assumptions
Stationary metrics and optical Zermelo-Randers-Finsler geometry
International Nuclear Information System (INIS)
Gibbons, G. W.; Warnick, C. M.; Herdeiro, C. A. R.; Werner, M. C.
2009-01-01
We consider a triality between the Zermelo navigation problem, the geodesic flow on a Finslerian geometry of Randers type, and spacetimes in one dimension higher admitting a timelike conformal Killing vector field. From the latter viewpoint, the data of the Zermelo problem are encoded in a (conformally) Painleve-Gullstrand form of the spacetime metric, whereas the data of the Randers problem are encoded in a stationary generalization of the usual optical metric. We discuss how the spacetime viewpoint gives a simple and physical perspective on various issues, including how Finsler geometries with constant flag curvature always map to conformally flat spacetimes and that the Finsler condition maps to either a causality condition or it breaks down at an ergo surface in the spacetime picture. The gauge equivalence in this network of relations is considered as well as the connection to analogue models and the viewpoint of magnetic flows. We provide a variety of examples.
Hopkins, Kristina G.; Bain, Daniel J.
2018-01-01
Identifying areas where deteriorating sewer infrastructure is in close proximity to surface waterways is needed to map likely connections between sewers and streams. We present a method to estimate sewer installation year and deterioration status using historical maps of the sewer network, parcel-scale property assessment data, and pipe material. Areas where streams were likely buried into the sewer system were mapped by intersecting the historical stream network derived from a 10-m resolution digital elevation model with sewer pipe locations. Potential sewer leakage hotspots were mapped by identifying where aging sewer pipes are in close proximity (50-m) to surface waterways. Results from Pittsburgh, Pennsylvania (USA), indicated 41% of the historical stream length was lost or buried and the potential interface between sewers and streams is great. The co-location of aging sewer infrastructure (>75 years old) near stream channels suggests that 42% of existing streams are located in areas with a high potential for sewer leakage if sewer infrastructure fails. Mapping the sewer-stream interface provides an approach to better understand areas were failing sewers may contribute a disproportional amount of nutrients and other pathogens to surface waterways.
Mars, John L.; Garrity, Christopher P.; Houseknecht, David W.; Amoroso, Lee; Meares, Donald C.
2007-01-01
Introduction The northeastern part of the National Petroleum Reserve in Alaska (NPRA) has become an area of active petroleum exploration during the past five years. Recent leasing and exploration drilling in the NPRA requires the U.S. Bureau of Land Management (BLM) to manage and monitor a variety of surface activities that include seismic surveying, exploration drilling, oil-field development drilling, construction of oil-production facilities, and construction of pipelines and access roads. BLM evaluates a variety of permit applications, environmental impact studies, and other documents that require rapid compilation and analysis of data pertaining to surface and subsurface geology, hydrology, and biology. In addition, BLM must monitor these activities and assess their impacts on the natural environment. Timely and accurate completion of these land-management tasks requires elevation, hydrologic, geologic, petroleum-activity, and cadastral data, all integrated in digital formats at a higher resolution than is currently available in nondigital (paper) formats. To support these land-management tasks, a series of maps was generated from remotely sensed data in an area of high petroleum-industry activity (fig. 1). The maps cover an area from approximately latitude 70?00' N. to 70?30' N. and from longitude 151?00' W. to 153?10' W. The area includes the Alpine oil field in the east, the Husky Inigok exploration well (site of a landing strip) in the west, many of the exploration wells drilled in NPRA since 2000, and the route of a proposed pipeline to carry oil from discovery wells in NPRA to the Alpine oil field. This map area is referred to as the 'Fish Creek area' after a creek that flows through the region. The map series includes (1) a color shaded-relief map based on 5-m-resolution data (sheet 1), (2) a surface-classification map based on 30-m-resolution data (sheet 2), and (3) a 5-m-resolution shaded relief-surface classification map that combines the shaded
Takagi, Kentaro; Nair, Selvakumar V.; Watanabe, Ryosuke; Seto, Keisuke; Kobayashi, Takayoshi; Tokunaga, Eiji
2017-12-01
Surface plasmon polariton (SPP) resonance spectra for noble metals (Au, Ag, and Cu) were comprehensively studied in the Kretschmann attenuated total reflection (ATR) geometry, in the wavelength (λ) range from 300 to 1000 nm with the angle of incidence (θ) ranging from 45 to 60° and the film thickness (d) ranging from 41 to 76 nm. The experimental plasmon resonance spectra were reproduced by a calculation that included the broadening effects as follows: (1) the imaginary part of the bulk dielectric constant, (2) the thickness-dependent radiative coupling of the SPP at the metal-air interface to the prism, (3) the lack of conservation of the wavevector parallel to the interface kx(k||) caused by the surface roughness, (4) scanning λ at a fixed θ (changing both energy and kx at the same time) over the SPP dispersion relation. For Au and Ag, the experimental results were in good agreement with the calculated results using the bulk dielectric constants, showing no film thickness dependence of the plasmon resonance energy. A method to extract the true width of the plasmon resonance from raw ATR spectra is proposed and the results are rigorously compared with those expected from the bulk dielectric function given in the literature. For Au and Ag, the width increases with energy, in agreement with that expected from the relaxation of bulk free electrons including the electron-electron interaction, but there is clear evidence of extra broadening, which is more significant for thinner films, possibly due to relaxation pathways intrinsic to plasmons near the interface. For Cu, the visibility of the plasmon resonance critically depends on the evaporation conditions, and low pressures and fast deposition rates are required. Otherwise, scattering from the surface roughness causes considerable broadening of the plasmon resonance, resulting in an apparently fixed resonance energy without clear incident angle dependence. For Cu, the observed plasmon dispersion agrees well with
Global Distribution of Shallow Water on Mars: Neutron Mapping of Summer-Time Surface by HEND/Odyssey
Mitrofanov, I. G.; Litvak, M. L.; Kozyrev, A. S.; Sanin, A. B.; Tretyakov, V. I.; Boynton, W.; Hamara, D.; Shinohara, C.; Saunders, R. S.; Drake, D.
2003-01-01
Orbital mapping of induced neutrons and gamma-rays by Odyssey has recently successfully proven the applicability of nuclear methods for studying of the elementary composition of Martian upper-most subsurface. In particular, the suite of Gamma-Ray Spectrometer (GRS) has discovered the presence of large water-ice rich regions southward and northward on Mars. The data of neutron mapping of summer-time surface are presented below from the Russian High Energy Neutron Spectrometer (HEND), which is a part of GRS suite. These maps represent the content of water in the soil for summer season at Southern and Northern hemispheres, when the winter deposit of CO2 is absent on the surface. The seasonal evolution of CO2 coverage on Mars is the subject of the complementary paper.
Global 30m 2000-2014 Surface Water Dynamics Map Derived from All Landsat 5, 7, and 8
Hudson, A.; Hansen, M.
2015-12-01
Water is critical for human life, agriculture, and ecosystems. A better understanding of where it is and how it is changing will enable better management of this valuable resource and guide protection of sensitive ecological areas. Global water maps have typically been representations of surface water at one given time. However, there is both seasonal and interannual variability: rivers meander, lakes disappear, floods arise. To address this ephemeral nature of water, in this study University of Maryland has developed a method that analyzes every Landsat 5, 7, and 8 scene from 1999-2015 to produce global seasonal maps (Winter, Spring, Summer, Fall) of surface water dynamics from 2000-2014. Each Landsat scene is automatically classified into land, water, cloud, haze, shadow, and snow via a decision tree algorithm. The land and water observations are aggregated per pixel into percent occurrence of water in a 3 year moving window for each meteorological season. These annual water percentages form a curve for each season that is discretized into a continuous 3 band RGB map. Frequency of water observation and type of surface water change (loss, gain, peak, or dip) is clearly seen through brightness and hue respectively. Additional data layers include: the year the change began, peak year, minimum year, and the year the change process ended. Currently these maps have been created for 18 1°x1° test tiles scattered around the world, and a portion of the September-November map over Bangladesh is shown below. The entire Landsat archive from 1999-2015 will be processed through a partnership with Google Earth Engine to complete the global product in the coming months. In areas where there is sufficient satellite data density (e.g. the United States), this project could be expanded to 1984-2015. This study provides both scientific researchers and the public an understandable, temporally rich, and globally consistent map showing surface water changes over time.
Global affine differential geometry of hypersurfaces
Li, An-Min; Zhao, Guosong; Hu, Zejun
2015-01-01
This book draws a colorful and widespread picture of global affine hypersurface theory up to the most recent state. Moreover, the recent development revealed that affine differential geometry- as differential geometry in general- has an exciting intersection area with other fields of interest, like partial differential equations, global analysis, convex geometry and Riemann surfaces.
Daffara, C.; Parisotto, S.; Mariotti, P. I.
2015-06-01
Cultural Heritage is discovering how precious is thermal analysis as a tool to improve the restoration, thanks to its ability to inspect hidden details. In this work a novel dual mode imaging approach, based on the integration of thermography and thermal quasi-reflectography (TQR) in the mid-IR is demonstrated for an effective mapping of surface materials and of sub-surface detachments in mural painting. The tool was validated through a unique application: the "Monocromo" by Leonardo da Vinci in Italy. The dual mode acquisition provided two spatially aligned dataset: the TQR image and the thermal sequence. Main steps of the workflow included: 1) TQR analysis to map surface features and 2) to estimate the emissivity; 3) projection of the TQR frame on reference orthophoto and TQR mosaicking; 4) thermography analysis to map detachments; 5) use TQR to solve spatial referencing and mosaicking for the thermal-processed frames. Referencing of thermal images in the visible is a difficult aspect of the thermography technique that the dual mode approach allows to solve in effective way. We finally obtained the TQR and the thermal maps spatially referenced to the mural painting, thus providing the restorer a valuable tool for the restoration of the detachments.
Emergent geometry of membranes
Energy Technology Data Exchange (ETDEWEB)
Badyn, Mathias Hudoba de; Karczmarek, Joanna L.; Sabella-Garnier, Philippe; Yeh, Ken Huai-Che [Department of Physics and Astronomy, University of British Columbia,6224 Agricultural Road, Vancouver (Canada)
2015-11-13
In work http://dx.doi.org/10.1103/PhysRevD.86.086001, a surface embedded in flat ℝ{sup 3} is associated to any three hermitian matrices. We study this emergent surface when the matrices are large, by constructing coherent states corresponding to points in the emergent geometry. We find the original matrices determine not only shape of the emergent surface, but also a unique Poisson structure. We prove that commutators of matrix operators correspond to Poisson brackets. Through our construction, we can realize arbitrary noncommutative membranes: for example, we examine a round sphere with a non-spherically symmetric Poisson structure. We also give a natural construction for a noncommutative torus embedded in ℝ{sup 3}. Finally, we make remarks about area and find matrix equations for minimal area surfaces.
Robichaud, Alain; Ménard, Richard; Zaïtseva, Yulia; Anselmo, David
2016-01-01
Air quality, like weather, can affect everyone, but responses differ depending on the sensitivity and health condition of a given individual. To help protect exposed populations, many countries have put in place real-time air quality nowcasting and forecasting capabilities. We present in this paper an optimal combination of air quality measurements and model outputs and show that it leads to significant improvements in the spatial representativeness of air quality. The product is referred to as multi-pollutant surface objective analyses (MPSOAs). Moreover, based on MPSOA, a geographical mapping of the Canadian Air Quality Health Index (AQHI) is also presented which provides users (policy makers, public, air quality forecasters, and epidemiologists) with a more accurate picture of the health risk anytime and anywhere in Canada and the USA. Since pollutants can also behave as passive atmospheric tracers, they provide information about transport and dispersion and, hence, reveal synoptic and regional meteorological phenomena. MPSOA could also be used to build air pollution climatology, compute local and national trends in air quality, and detect systematic biases in numerical air quality (AQ) models. Finally, initializing AQ models at regular time intervals with MPSOA can produce more accurate air quality forecasts. It is for these reasons that the Canadian Meteorological Centre (CMC) in collaboration with the Air Quality Research Division (AQRD) of Environment Canada has recently implemented MPSOA in their daily operations.
Mapping cellular hierarchy by single-cell analysis of the cell surface repertoire.
Guo, Guoji; Luc, Sidinh; Marco, Eugenio; Lin, Ta-Wei; Peng, Cong; Kerenyi, Marc A; Beyaz, Semir; Kim, Woojin; Xu, Jian; Das, Partha Pratim; Neff, Tobias; Zou, Keyong; Yuan, Guo-Cheng; Orkin, Stuart H
2013-10-03
Stem cell differentiation pathways are most often studied at the population level, whereas critical decisions are executed at the level of single cells. We have established a highly multiplexed, quantitative PCR assay to profile in an unbiased manner a panel of all commonly used cell surface markers (280 genes) from individual cells. With this method, we analyzed over 1,500 single cells throughout the mouse hematopoietic system and illustrate its utility for revealing important biological insights. The comprehensive single cell data set permits mapping of the mouse hematopoietic stem cell differentiation hierarchy by computational lineage progression analysis. Further profiling of 180 intracellular regulators enabled construction of a genetic network to assign the earliest differentiation event during hematopoietic lineage specification. Analysis of acute myeloid leukemia elicited by MLL-AF9 uncovered a distinct cellular hierarchy containing two independent self-renewing lineages with different clonal activities. The strategy has broad applicability in other cellular systems. Copyright © 2013 Elsevier Inc. All rights reserved.
Project CONVERGE: Initial Results From the Mapping of Surface Currents in Palmer Deep
Statscewich, H.; Kohut, J. T.; Winsor, P.; Oliver, M. J.; Bernard, K. S.; Cimino, M. A.; Fraser, W.
2016-02-01
The Palmer Deep submarine canyon on the Western Antarctic Peninsula provides a conduit for upwelling of relatively warm, nutrient rich waters which enhance local primary production and support a food web productive enough to sustain a large top predator biomass. In an analysis of ten years of satellite-tagged penguins, Oliver et al. (2013) showed that circulation features associated with tidal flows may be a key driver of nearshore predator distributions. During diurnal tides, the penguins feed close to their breeding colonies and during semi-diurnal tides, the penguins make foraging trips to the more distant regions of Palmer Deep. It is hypothesized that convergent features act to concentrate primary producers and aggregate schools of krill that influence the behavior of predator species. The initial results from a six month deployment of a High Frequency Radar network in Palmer Deep are presented in an attempt to characterize and quantify convergent features. During a three month period from January through March 2015, we conducted in situ sampling consisting of multiple underwater glider deployments, small boat acoustic surveys of Antarctic krill, and penguin ARGOS-linked satellite telemetry and time-depth recorders (TDRs). The combination of real-time surface current maps with adaptive in situ sampling introduces High Frequency Radar to the Antarctic in a way that allows us to rigorously and efficiently test the influence of local tidal processes on top predator foraging ecology.
International Nuclear Information System (INIS)
Gardner, J.N.; Lavine, A.; Vaniman, D.; WoldeGabriel, G.
1998-06-01
In this report the authors document results of high-precision geologic mapping in the vicinity of TA-55 that has been done to identify parts of the southern portion of the Rendija Canyon Fault, or any other faults, with the potential for seismic surface rupture. To assess the potential for surface rupture at TA-55, an area of approximately 3 square miles that includes the Los Alamos County Landfill and Twomile, Mortandad, and Sandia Canyons has been mapped in detail. Map units are mostly cooling or flow units within the Tshirege Member (1.2 Ma) of the Bandelier Tuff. Stratigraphic markers that are useful for determining offsets in the map area include a distinct welding break at or near the cooling Unit 2-Unit 3 contact, and the Unit 3-Unit 4 contact. At the County Landfill the contact between the Tshirege Member of the Bandelier Tuff and overlying Quaternary alluvium has also been mapped. The mapping indicates that there is no faulting in the near-surface directly below TA-55, and that the closest fault is about 1500 feet west of the Plutonium Facility. Faulting is more abundant on the western edge of the map area, west of TA-48 in uppermost Mortandad Canyon, upper Sandia Canyon, and at the County Landfill. Measured vertical offsets on the faults range from 1 to 8 feet on mapped Bandelier Tuff contacts. Faulting exposed at the Los Alamos County Landfill has deformed a zone over 1000 feet wide, and has a net vertical down-to-the-west displacement of at least 15 feet in the Bandelier Tuff. Individual faults at the landfill have from less than 1 foot to greater than 15 feet of vertical offset on the Bandelier Tuff. Most faults in the landfill trend N-S, N20W, or N45E. Results of the mapping indicate that the Rendija Canyon Fault does not continue directly south to TA-55. At present, the authors have insufficient data to connect faulting they have mapped to areas of known faulting to the north or south of the study area
Cornish, Sam; Searle, Mike
2017-08-01
The Wadi Mayh sheath fold in north-eastern Oman is one of the largest and best-exposed sheath folds known, and presents a unique opportunity to better understand this somewhat enigmatic style of deformation. We undertook high-resolution photographic surveying along Wadi Mayh to document the sheath fold in 61 georeferenced panoramic photomerges. Here we present ten such images that provide a structural interpretation of the sheath fold and surrounding structure. We resolve this structure in a simplified three-dimensional model and in two orthogonal cross sections, and propose a kinematic evolution to explain the geometry. The Wadi Mayh sheath fold is the most prominent example within what we suggest is a composite sequence of sheath folds, which is itself enclosed within a SSW-closing recumbent syncline at the base of the major Saih Hatat nappe. Sheath folding is accommodated within Permian Saiq Formation limestones showing carpholite assemblages (6-8 kbar; 275-375 °C). A major discontinuity separates this sequence from enveloping older rock units. The sequence formed during progressive top-to-north, ductile shearing as the overlying nappe migrated northwards with respect to the underthrusting Hulw unit. This process occurred during SSW-directed exhumation of partially subducted continental crust in NE Oman, approximately 15 Ma after obduction of the Oman ophiolite initiated.
Multivariate calculus and geometry
Dineen, Seán
2014-01-01
Multivariate calculus can be understood best by combining geometric insight, intuitive arguments, detailed explanations and mathematical reasoning. This textbook has successfully followed this programme. It additionally provides a solid description of the basic concepts, via familiar examples, which are then tested in technically demanding situations. In this new edition the introductory chapter and two of the chapters on the geometry of surfaces have been revised. Some exercises have been replaced and others provided with expanded solutions. Familiarity with partial derivatives and a course in linear algebra are essential prerequisites for readers of this book. Multivariate Calculus and Geometry is aimed primarily at higher level undergraduates in the mathematical sciences. The inclusion of many practical examples involving problems of several variables will appeal to mathematics, science and engineering students.
Advances in discrete differential geometry
2016-01-01
This is one of the first books on a newly emerging field of discrete differential geometry and an excellent way to access this exciting area. It surveys the fascinating connections between discrete models in differential geometry and complex analysis, integrable systems and applications in computer graphics. The authors take a closer look at discrete models in differential geometry and dynamical systems. Their curves are polygonal, surfaces are made from triangles and quadrilaterals, and time is discrete. Nevertheless, the difference between the corresponding smooth curves, surfaces and classical dynamical systems with continuous time can hardly be seen. This is the paradigm of structure-preserving discretizations. Current advances in this field are stimulated to a large extent by its relevance for computer graphics and mathematical physics. This book is written by specialists working together on a common research project. It is about differential geometry and dynamical systems, smooth and discrete theories, ...
CosmoQuest - Mapping Surface Features Across the Inner Solar System
Grier, Jennifer A.; Richardson, Matthew; Gay, Pamela L.; Lehan, Cory; Owens, Ryan; Robbins, Stuart J.; DellaGiustina, Daniella; Bennett, Carina; Runco, Susan; Graff, Paige
2017-10-01
The CosmoQuest Virtual Research Facility allows research scientists to work together with citizen scientists in ‘big data’ investigations. Some research requires the examination of vast numbers of images - partnering with engaged and trained citizen scientists allows for that research to be completed in a thorough and timely manner. The techniques used by CosmoQuest to collect impact crater data have been validated to ensure robustness (Robbins et al., 2014), and include software tools that accurately identify crater clusters, and multiple crater identifications. CosmoQuest has current or up-and-coming projects that span much of the inner solar system. “Moon Mappers” gives the public a chance to learn about the importance of cratered surfaces, and investigate factors that effect the identification and measurement of impact craters such as incidence angle. In the “Mars Mappers” program citizens map small craters in valley networks. These will be used to estimate times of ancient water flow. In “Mercury Mappers” the public learns about other issues related to crater counting, such as secondaries. On Mercury, secondaries appear to dominate counts up to 10km. By mapping these craters, we will be able to better understand the maximum diameter of secondaries relative to the parent primary. The public encounters Vesta in “Vesta Mappers,” a project that contributes data to the overall crater counting efforts on that body. Asteroid investigations do not end there - the OSIRIS-REx team is collaborating with CosmoQuest to create a science campaign to generate boulder and crater counting datasets of the asteroid Bennu. This “Bennu Mappers” project will inform the final selection of the sample return site. The Earth is the target for the “Image Detective” project, which uses the 2 million images returned from crewed space flight. These images are rich in information about our changing Earth, as well as phenomena like aurora. Citizens tag these images
Surface Water Mapping from Suomi NPP-VIIRS Imagery at 30 m Resolution via Blending with Landsat Data
Directory of Open Access Journals (Sweden)
Chang Huang
2016-07-01
Full Text Available Monitoring the dynamics of surface water using remotely sensed data generally requires both high spatial and high temporal resolutions. One effective and popular approach for achieving this is image fusion. This study adopts a widely accepted fusion model, the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM, for blending the newly available coarse-resolution Suomi NPP-VIIRS data with Landsat data in order to derive water maps at 30 m resolution. The Pan-sharpening technique was applied to preprocessing NPP-VIIRS data to achieve a higher-resolution before blending. The modified Normalized Difference Water Index (mNDWI was employed for mapping surface water area. Two fusion alternatives, blend-then-index (BI or index-then-blend (IB, were comparatively analyzed against a Landsat derived water map. A case study of mapping Poyang Lake in China, where water distribution pattern is complex and the water body changes frequently and drastically, was conducted. It has been revealed that the IB method derives more accurate results with less computation time than the BI method. The BI method generally underestimates water distribution, especially when the water area expands radically. The study has demonstrated the feasibility of blending NPP-VIIRS with Landsat for achieving surface water mapping at both high spatial and high temporal resolutions. It suggests that IB is superior to BI for water mapping in terms of efficiency and accuracy. The finding of this study also has important reference values for other blending works, such as image blending for vegetation cover monitoring.
Maps of surface activity of 137Cs of Slovakia on scale 1:200 000
International Nuclear Information System (INIS)
Gluch, A.
2005-05-01
The present set of maps (13 maps) arose from the geological project 'Re-ambulation of 137 Cs radioactivity map of Slovakia at scales 1:200 000 and 1:500 000' in phase of indicative geological survey of environmental factors. Maps document the state of contamination of the territory of Slovakia by one of the radioisotopes cesium-137 at the reference date 01.01.2005. In solving of geological tasks were used all available relevant data on measurements of 137 Cs activity from the whole territory of the Slovak Republic for the period from 1990 to 2003 from results of air and ground gamma spectrometric measurements. (authors)
Chen, I.-Ting; Chang, Li-Chiu; Chang, Fi-John
2018-01-01
In this study, we propose a soft-computing methodology to visibly explore the spatio-temporal groundwater variations of the Kuoping River basin in southern Taiwan. The self-organizing map (SOM) is implemented to investigate the interactive mechanism between surface water and groundwater over the river basin based on large high-dimensional data sets coupled with their occurrence times. We find that extracting the occurrence time from each 30-day moving average data set in the clustered neurons of the SOM is a crucial step to learn the spatio-temporal interaction between surface water and groundwater. We design 2-D Topological Bubble Map to summarize all the groundwater values of four aquifers in a neuron, which can visibly explore the major features of the groundwater in the vertical direction. The constructed SOM topological maps nicely display that: (1) the groundwater movement, in general, extends from the eastern area to the western, where groundwater in the eastern area can be easily recharged from precipitation in wet seasons and discharged into streams during dry seasons due to the high permeability in this area; (2) the water movements in the four aquifers of the study area are quite different, and the seasonal variations of groundwater in the second and third aquifers are larger than those of the others; and (3) the spatial distribution and seasonal variations of groundwater and surface water are comprehensively linked together over the constructed maps to present groundwater characteristics and the interrelation between groundwater and surface water. The proposed modeling methodology not only can classify the large complex high-dimensional data sets into visible topological maps to effectively facilitate the quantitative status of regional groundwater resources but can also provide useful elaboration for future groundwater management.
Simonyi, Gábor; Kirschner, Róbert; Szűcs, Endre; Préda, István; Duray, Gábor; Medvegy, Nóra; Horvath, Bálint; Medvegy, Mihály
2016-03-01
In coronary artery disease (CAD), body surface potential mapping (BSPM) may reveal minor electrical potential changes appearing in the depolarization phase even if pathological changes are absent on the conventional 12-lead ECG. We hypothesized that a simple BSPM parameter, Max/Min signifies successful percutaneous coronary intervention (PCI). Ninety-two adult Caucasian patients with stable CAD and positive exercise test underwent coronary angiography. Seventy patients (age, 59 ± 8; 46 males) were revascularized by PCI (left anterior descending [LAD] in 38, right [RCA] in 17 and left circumflex [LCX] coronary artery in 15). Control groups contained 22 patients (age, 60 ± 8; 14 males) without intervention and 35 healthy subjects (age, 58 ± 2; 15 males). Left ventricular ejection fraction (LVEF, transthoracic echocardiography) and Max/Min BSPM parameter (63-lead Montreal system) were evaluated before and 4-40 days following coronary angiography. Max/Min was defined by the ratio of the highest maximum to the deepest minimum potential of all leads recorded by BSPM. Before PCI, Max/Min value of patients with LAD lesion (0.83 [0.74; 0.93]) was significantly lower while that with RCA lesion (1.63 [1.35; 1.99]) was significantly higher than that of healthy group (1.01 [0.970; 1.13]) (P intervention. LVEF significantly increased (from 46.50% [43.00; 51.00] to 49.00% [46.00; 51.00]) only after LAD PCI. Max/Min parameter is suitable to follow patients after LAD and RCA PCI. © 2015 Wiley Periodicals, Inc.
SU-E-J-193: Application of Surface Mapping in Detecting Swallowing for Head-&-Neck Cancer
Energy Technology Data Exchange (ETDEWEB)
Cao, D; Xie, X; Mehta, V; Shepard, D [Swedish Cancer Institute, Seattle, WA (United States)
2015-06-15
Purpose: Recent evidence is emerging that long term swallowing function may be improved after radiotherapy for head-&-neck cancer if doses are limited to certain swallowing structures. Immobilization of patients with head-&-neck cancer is typically done with a mask. This mask, however, doesn’t limit patient swallowing. Patient voluntary or involuntary swallowing may introduce significant tumor motion, which can lead to suboptimal delivery. In this study, we have examined the feasibility of using surface mapping technology to detect patient swallowing during treatment and evaluated its magnitude. Methods: The C-RAD Catalyst system was used to detect the patient surface map. A volunteer lying on the couch was used to simulate the patient under treatment. A virtual marker was placed near the throat and was used to monitor the swallowing action. The target motion calculated by the Catalyst system through deformable registration was also collected. Two treatment isocenters, one placed close to the throat and the other placed posterior to the base-of-tongue, were used to check the sensitivity of surface mapping technique. Results: When the patient’s throat is not in the shadow of the patient’s chest, the Catalyst system can clearly identify the swallowing motion. In our tests, the vertical motion of the skin can reach to about 5mm. The calculated target motion can reach up to 1 cm. The magnitude of this calculated target motion is more dramatic when the plan isocenter is closer to the skin surface, which suggests that the Catalyst motion tracking technique is more sensitive to the swallowing motion with a shallower isocenter. Conclusion: Surface mapping can clearly identify patient swallowing during radiation treatment. This information can be used to evaluate the dosimetric impact of the involuntary swallowing. It may also be used to potentially gate head-&-neck radiation treatments. A prospective IRB approved study is currently enrolling patients in our
2015-01-01
This stimulating volume offers a broad collection of the principles of geometry and trigonometry and contains colorful diagrams to bring mathematical principles to life. Subjects are enriched by references to famous mathematicians and their ideas, and the stories are presented in a very comprehensible way. Readers investigate the relationships of points, lines, surfaces, and solids. They study construction methods for drawing figures, a wealth of facts about these figures, and above all, methods to prove the facts. They learn about triangle measure for circular motion, sine and cosine, tangent
Fast, V G; Kléber, A G
1995-05-01
Unidirectional conduction block (UCB) and reentry may occur as a consequence of an abrupt tissue expansion and a related change in the electrical load. The aim of this study was to evaluate critical dimensions of the tissue necessary for establishing UCB in heart cell culture. Neonatal rat heart cell cultures with cell strands of variable width emerging into a large cell area were grown using a technique of patterned cell growth. Action potential upstrokes were measured using a voltage sensitive dye (RH-237) and a linear array of 10 photodiodes with a 15 microns resolution. A mathematical model was used to relate action potential wave shapes to underlying ionic currents. UCB (block of a single impulse in anterograde direction - from a strand to a large area - and conduction in the retrograde direction) occurred in narrow cell strands with a width of 15(SD 4) microns (1-2 cells in width, n = 7) and there was no conduction block in strands with a width of 31(8) microns (n = 9, P multiple rising phases. Mathematical modelling showed that two rising phases were caused by electronic current flow, whereas local ionic current did not coincide with the rising portions of the upstrokes. (1) High resolution optical mapping shows multiphasic action potential upstrokes at the region of abrupt expansion. At the site of the maximum decrement in conduction, these peaks were largely determined by the electrotonus and not by the local ionic current. (2) Unidirectional conduction block occurred in strands with a width of 15(4) microns (1-2 cells).
Silva, Alessandro
1993-01-01
The papers in this wide-ranging collection report on the results of investigations from a number of linked disciplines, including complex algebraic geometry, complex analytic geometry of manifolds and spaces, and complex differential geometry.
Eisenhart, Luther Pfahler
2005-01-01
This concise text by a prominent mathematician deals chiefly with manifolds dominated by the geometry of paths. Topics include asymmetric and symmetric connections, the projective geometry of paths, and the geometry of sub-spaces. 1927 edition.
SAFARI 2000 AVHRR-derived Land Surface Temperature Maps, Africa, 1995-2000
National Aeronautics and Space Administration — Land Surface Temperature (LST) is a key indicator of land surface states, and can provide information on surface-atmosphere heat and mass fluxes, vegetation water...
SAFARI 2000 AVHRR-derived Land Surface Temperature Maps, Africa, 1995-2000
National Aeronautics and Space Administration — ABSTRACT: Land Surface Temperature (LST) is a key indicator of land surface states, and can provide information on surface-atmosphere heat and mass fluxes,...
International Nuclear Information System (INIS)
Gurevich, L.Eh.; Gliner, Eh.B.
1978-01-01
Problems of investigating the Universe space-time geometry are described on a popular level. Immediate space-time geometries, corresponding to three cosmologic models are considered. Space-time geometry of a closed model is the spherical Riemann geonetry, of an open model - is the Lobachevskij geometry; and of a plane model - is the Euclidean geometry. The Universe real geometry in the contemporary epoch of development is based on the data testifying to the fact that the Universe is infinitely expanding
The Development of 3d Sub-Surface Mapping Scheme and its Application to Martian Lobate Debris Aprons
Baik, H.; Kim, J.
2017-07-01
The Shallow Subsurface Radar (SHARAD), a sounding radar equipped on the Mars Reconnaissance Orbiter (MRO), has produced highly valuable information about the Martian subsurface. In particular, the complicated substructures of Mars such as polar deposit, pedestal crater and the other geomorphic features involving possible subsurface ice body has been successfully investigated by SHARAD. In this study, we established a 3D subsurface mapping strategy employing the multiple SHARAD profiles. A number of interpretation components of SHARAD signals were integrated into a subsurface mapping scheme using radargram information and topographic data, then applied over a few mid latitude Lobate Debris Aprons (LDAs). From the identified subsurface layers of LDA, and the GIS data base incorporating the other interpretation outcomes, we are expecting to trace the origin of LDAs. Also, the subsurface mapping scheme developed in this study will be further applied to other interesting Martian geological features such as inter crater structures, aeolian deposits and fluvial sediments. To achieve higher precision sub-surface mapping, the clutter simulation employing the high resolution topographic data and the upgraded clustering algorithms assuming multiple sub-surface layers will be also developed.
Directory of Open Access Journals (Sweden)
Ramanathan Sugumaran
2008-08-01
Full Text Available The goal of this project was to map the surface temperature of the University of Northern Iowa campus using high-resolution thermal infrared aerial imageries. A thermal camera with a spectral bandwidth of 3.0-5.0 ÃŽÂ¼m was flown at the average altitude of 600 m, achieving ground resolution of 29 cm. Ground control data was used to construct the pixelto-temperature conversion model, which was later used to produce temperature maps of the entire campus and also for validation of the model. The temperature map then was used to assess the building rooftop conditions and steam line faults in the study area. Assessment of the temperature map revealed a number of building structures that may be subject to insulation improvement due to their high surface temperatures leaks. Several hot spots were also identified on the campus for steam pipelines faults. High-resolution thermal infrared imagery proved highly effective tool for precise heat anomaly detection on the campus, and it can be used by university facility services for effective future maintenance of buildings and grounds.
Savelyev, Alexander; Sugumaran, Ramanathan
2008-01-01
The goal of this project was to map the surface temperature of the University of Northern Iowa campus using high-resolution thermal infrared aerial imageries. A thermal camera with a spectral bandwidth of 3.0-5.0 μm was flown at the average altitude of 600 m, achieving ground resolution of 29 cm. Ground control data was used to construct the pixel- to-temperature conversion model, which was later used to produce temperature maps of the entire campus and also for validation of the model. The temperature map then was used to assess the building rooftop conditions and steam line faults in the study area. Assessment of the temperature map revealed a number of building structures that may be subject to insulation improvement due to their high surface temperatures leaks. Several hot spots were also identified on the campus for steam pipelines faults. High-resolution thermal infrared imagery proved highly effective tool for precise heat anomaly detection on the campus, and it can be used by university facility services for effective future maintenance of buildings and grounds. PMID:27873800
Differential geometry and topology with a view to dynamical systems
Burns, Keith
2005-01-01
MANIFOLDSIntroductionReview of topological conceptsSmooth manifoldsSmooth mapsTangent vectors and the tangent bundleTangent vectors as derivationsThe derivative of a smooth mapOrientationImmersions, embeddings and submersionsRegular and critical points and valuesManifolds with boundarySard's theoremTransversalityStabilityExercisesVECTOR FIELDS AND DYNAMICAL SYSTEMSIntroductionVector fieldsSmooth dynamical systemsLie derivative, Lie bracketDiscrete dynamical systemsHyperbolic fixed points and periodic orbitsExercisesRIEMANNIAN METRICSIntroductionRiemannian metricsStandard geometries on surfacesExercisesRIEMANNIAN CONNECTIONS AND GEODESICSIntroductionAffine connectionsRiemannian connectionsGeodesicsThe exponential mapMinimizing properties of geodesicsThe Riemannian distanceExercisesCURVATUREIntroductionThe curvature tensorThe second fundamental formSectional and Ricci curvaturesJacobi fieldsManifolds of constant curvatureConjugate pointsHorizontal and vertical sub-bundlesThe geodesic flowExercisesTENSORS AND DI...
DEFF Research Database (Denmark)
Bording, Thue Sylvester; Fiandaca, Gianluca; Maurya, Pradip Kumar
Traditional methods for mapping possible flowpaths of contaminants in sedimentary environments by boreholes may often be insufficient. Additional information may be acquired by geophysical methods. In the present study, cross-borehole and surface measurements were performed using time-domain indu......-domain induced polarization (TDIP). After measurements the entire test site was dug out, and the geology was described. A 2D spectral inversion of the combined dataset is presented, which is in great correspondence with the observed geology....
Instanton strings and hyper-Kaehler geometry
International Nuclear Information System (INIS)
Dijkgraaf, Robbert
1999-01-01
We discuss two-dimensional sigma models on moduli spaces of instantons on K3 surfaces. These N = (4, 4) superconformal field theories describe the near-horizon dynamics of the D1-D5-brane system and are dual to string theory on AdS 3 . We derive a precise map relating the moduli of the K3 type 1113 string compactification to the moduli of these conformal field theories and the corresponding classical hyper-Kahler geometry. We conclude that in the absence of background gauge fields, the metric on the instanton moduli spaces degenerates exactly to the orbifold symmetric product of K3. Turning on a self-dual NS B-field deforms this symmetric product to a manifold that is diffeomorphic to the Hilbert scheme. We also comment on the mathematical applications of string duality to the global issues of deformations of hyper-Kaehler manifolds
Map showing selected surface-water data for the Nephi 30 x 60-minute quadrangle, Utah
Price, Don
1984-01-01
This is one of a series of maps that describe the geology and related natural resources of the Nephi 30 x 60 minute quadrangle, Utah. Streamflow records used to compile this map were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Transportation. The principal runoff-producing areas shown on the map were delineated from a work map (scale 1:250,000) compiled to estimate water yields in Utah (Bagley and others, 1964). Sources of information about recorded floods resulting from cloudbursts included Woolley (1946) and Butler and Marsell (1972); sources of information about the chemical quality of streamflow included Hahl and Cabell (1965) Mundorff (1972 and 1974), and Waddell and others (1982).
Map showing selected surface-water data for the Huntington 30 x 60-minute quadrangle, Utah
Price, Don
1984-01-01
This is one of a series of maps that describe the geology and related natural resources of the Huntington 30 x 60-minute quadrangle, Utah. Streamflow records used to compile this map were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Transportation. The principal runoff-producing area shown on the map was delineated from a work map (scale 1:250,000) compiled to estimate water yields in Utah (Bagley and others, 1964). Sources of information about recorded floods resulting from cloudbursts included Woolley (1946) and Butler and Marsell (1972); sources of information about the chemical quality of streamflow included Mundorff (1972) and Mundorff and Thompson (1982).
Map showing selected surface-water data for the Manti 30 x 60-minute Quadrangle, Utah
Price, Don
1984-01-01
This is one of a series of maps that describe the geology and related natural resources of the Manti 30 x 60 minute quadrangle. Streamflow records used to compile this map were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Transportation. The principal runoff-producing areas shown on the map were delineated from a work map (scale 1:250,000) compiled to estimate water yields in Utah (Bagley and others, 1964). Sources of information about recorded floods resulting from cloudbursts included Woolley (1946) and Butler and Marsell (1972); sources of information about the chemical quality of streamflow included Hahl and Cabell (1965) and Mundorff and Thompson (1982).
Map showing selected surface-water data for the Price 30 x 60-minute Quadrangle, Utah
Price, Don
1984-01-01
This is one of a series of maps that describe the geology and related natural resources of the Price 30 x 60-minute quadrangle, Utah. Streamflow records used to compile this map were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Transportation. The principal runoff-producing areas shown on the map were delineated from a work map (scale 1:250,000) compiled to estimate water yields in Utah (Bagley and others, 1964). Sources of information about recorded floods resulting from cloudbursts included Woolley (1946) and Butler and Marsell (1972); sources of information about the chemical quality of streamflow included Mundorff (1972; 1977), and Waddell and others (1982).
GEOMETRY – AN IMPORTANT MEANS OF EDUCATION IN THE CIVILISATION SCOPE
Liliana TOCARIU, PhD
2017-01-01
Geometry (from the Greek: γεωμετρία; geo = earth, metria = measure) is a genuine science, rooted in mathematics, which studies the plane and spatial forms of bodies from the objective or conceptual reality and the nature of the relationship that exists between them. Due to its complexity, geometry is divided into: Euclidian geometry, analytical geometry, descriptive geometry, projective geometry, kinematic geometry, surface and curve differential geometry, axiomatic geometry,...
Euclidean geometry and its subgeometries
Specht, Edward John; Calkins, Keith G; Rhoads, Donald H
2015-01-01
In this monograph, the authors present a modern development of Euclidean geometry from independent axioms, using up-to-date language and providing detailed proofs. The axioms for incidence, betweenness, and plane separation are close to those of Hilbert. This is the only axiomatic treatment of Euclidean geometry that uses axioms not involving metric notions and that explores congruence and isometries by means of reflection mappings. The authors present thirteen axioms in sequence, proving as many theorems as possible at each stage and, in the process, building up subgeometries, most notably the Pasch and neutral geometries. Standard topics such as the congruence theorems for triangles, embedding the real numbers in a line, and coordinatization of the plane are included, as well as theorems of Pythagoras, Desargues, Pappas, Menelaus, and Ceva. The final chapter covers consistency and independence of axioms, as well as independence of definition properties. There are over 300 exercises; solutions to many of the...
Farhadi, Leila; Entekhabi, Dara; Salvucci, Guido
2016-04-01
In this study, we develop and apply a mapping estimation capability for key unknown parameters that link the surface water and energy balance equations. The method is applied to the Gourma region in West Africa. The accuracy of the estimation method at point scale was previously examined using flux tower data. In this study, the capability is scaled to be applicable with remotely sensed data products and hence allow mapping. Parameters of the system are estimated through a process that links atmospheric forcing (precipitation and incident radiation), surface states, and unknown parameters. Based on conditional averaging of land surface temperature and moisture states, respectively, a single objective function is posed that measures moisture and temperature-dependent errors solely in terms of observed forcings and surface states. This objective function is minimized with respect to parameters to identify evapotranspiration and drainage models and estimate water and energy balance flux components. The uncertainty of the estimated parameters (and associated statistical confidence limits) is obtained through the inverse of Hessian of the objective function, which is an approximation of the covariance matrix. This calibration-free method is applied to the mesoscale region of Gourma in West Africa using multiplatform remote sensing data. The retrievals are verified against tower-flux field site data and physiographic characteristics of the region. The focus is to find the functional form of the evaporative fraction dependence on soil moisture, a key closure function for surface and subsurface heat and moisture dynamics, using remote sensing data.
DEFF Research Database (Denmark)
Fredenslund Levinsen, Joanna; Howat, I. M.; Tscherning, C. C.
2013-01-01
We combine the complementary characteristics of laser altimeter data and stereoscopic digital elevation models (DEMs) to construct high-resolution (_100 m) maps of surface elevations and elevation changes over rapidly changing outlet glaciers in Greenland. Measurements from spaceborne and airborne...... laser altimeters have relatively low errors but are spatially limited to the ground tracks, while DEMs have larger errors but provide spatially continuous surfaces. The principle of our method is to fit the DEM surface to the altimeter point clouds in time and space to minimize the DEM errors and use...... that surface to extrapolate elevations away from altimeter flight lines. This reduces the DEM registration errors and fills the gap between the altimeter paths. We use data from ICESat and ATM as well as SPOT 5 DEMs from 2007 and 2008 and apply them to the outlet glaciers Jakobshavn Isbræ (JI...
XML-BSPM: an XML format for storing Body Surface Potential Map recordings.
Bond, Raymond R; Finlay, Dewar D; Nugent, Chris D; Moore, George
2010-05-14
The Body Surface Potential Map (BSPM) is an electrocardiographic method, for recording and displaying the electrical activity of the heart, from a spatial perspective. The BSPM has been deemed more accurate for assessing certain cardiac pathologies when compared to the 12-lead ECG. Nevertheless, the 12-lead ECG remains the most popular ECG acquisition method for non-invasively assessing the electrical activity of the heart. Although data from the 12-lead ECG can be stored and shared using open formats such as SCP-ECG, no open formats currently exist for storing and sharing the BSPM. As a result, an innovative format for storing BSPM datasets has been developed within this study. The XML vocabulary was chosen for implementation, as opposed to binary for the purpose of human readability. There are currently no standards to dictate the number of electrodes and electrode positions for recording a BSPM. In fact, there are at least 11 different BSPM electrode configurations in use today. Therefore, in order to support these BSPM variants, the XML-BSPM format was made versatile. Hence, the format supports the storage of custom torso diagrams using SVG graphics. This diagram can then be used in a 2D coordinate system for retaining electrode positions. This XML-BSPM format has been successfully used to store the Kornreich-117 BSPM dataset and the Lux-192 BSPM dataset. The resulting file sizes were in the region of 277 kilobytes for each BSPM recording and can be deemed suitable for example, for use with any telemonitoring application. Moreover, there is potential for file sizes to be further reduced using basic compression algorithms, i.e. the deflate algorithm. Finally, these BSPM files have been parsed and visualised within a convenient time period using a web based BSPM viewer. This format, if widely adopted could promote BSPM interoperability, knowledge sharing and data mining. This work could also be used to provide conceptual solutions and inspire existing formats
Ardalan, A.; Safari, A.; Grafarend, E.
2003-04-01
An operational algorithm for computing the ellipsoidal terrain correction based on application of closed form solution of the Newton integral in terms of Cartesian coordinates in the cylindrical equal area map projected surface of a reference ellipsoid has been developed. As the first step the mapping of the points on the surface of a reference ellipsoid onto the cylindrical equal area map projection of a cylinder tangent to a point on the surface of reference ellipsoid closely studied and the map projection formulas are computed. Ellipsoidal mass elements with various sizes on the surface of the reference ellipsoid is considered and the gravitational potential and the vector of gravitational intensity of these mass elements has been computed via the solution of Newton integral in terms of ellipsoidal coordinates. The geographical cross section areas of the selected ellipsoidal mass elements are transferred into cylindrical equal area map projection and based on the transformed area elements Cartesian mass elements with the same height as that of the ellipsoidal mass elements are constructed. Using the close form solution of the Newton integral in terms of Cartesian coordinates the potential of the Cartesian mass elements are computed and compared with the same results based on the application of the ellipsoidal Newton integral over the ellipsoidal mass elements. The results of the numerical computations show that difference between computed gravitational potential of the ellipsoidal mass elements and Cartesian mass element in the cylindrical equal area map projection is of the order of 1.6 × 10-8m^2/s^2 for a mass element with the cross section size of 10 km × 10 km and the height of 1000 m. For a 1 km × 1 km mass element with the same height, this difference is less than 1.5 × 10-4 m^2}/s^2. The results of the numerical computations indicate that a new method for computing the terrain correction based on the closed form solution of the Newton integral in
Canonical differential geometry of string backgrounds
International Nuclear Information System (INIS)
Schuller, Frederic P.; Wohlfarth, Mattias N.R.
2006-01-01
String backgrounds and D-branes do not possess the structure of Lorentzian manifolds, but that of manifolds with area metric. Area metric geometry is a true generalization of metric geometry, which in particular may accommodate a B-field. While an area metric does not determine a connection, we identify the appropriate differential geometric structure which is of relevance for the minimal surface equation in such a generalized geometry. In particular the notion of a derivative action of areas on areas emerges naturally. Area metric geometry provides new tools in differential geometry, which promise to play a role in the description of gravitational dynamics on D-branes
Germaine, Stephen S.; O'Donnell, Michael S.; Aldridge, Cameron L.; Baer, Lori; Fancher, Tammy; McBeth, Jamie; McDougal, Robert R.; Waltermire, Robert; Bowen, Zachary H.; Diffendorfer, James; Garman, Steven; Hanson, Leanne
2012-01-01
We evaluated how well three leading information-extraction software programs (eCognition, Feature Analyst, Feature Extraction) and manual hand digitization interpreted information from remotely sensed imagery of a visually complex gas field in Wyoming. Specifically, we compared how each mapped the area of and classified the disturbance features present on each of three remotely sensed images, including 30-meter-resolution Landsat, 10-meter-resolution SPOT (Satellite Pour l'Observation de la Terre), and 0.6-meter resolution pan-sharpened QuickBird scenes. Feature Extraction mapped the spatial area of disturbance features most accurately on the Landsat and QuickBird imagery, while hand digitization was most accurate on the SPOT imagery. Footprint non-overlap error was smallest on the Feature Analyst map of the Landsat imagery, the hand digitization map of the SPOT imagery, and the Feature Extraction map of the QuickBird imagery. When evaluating feature classification success against a set of ground-truthed control points, Feature Analyst, Feature Extraction, and hand digitization classified features with similar success on the QuickBird and SPOT imagery, while eCognition classified features poorly relative to the other methods. All maps derived from Landsat imagery classified disturbance features poorly. Using the hand digitized QuickBird data as a reference and making pixel-by-pixel comparisons, Feature Extraction classified features best overall on the QuickBird imagery, and Feature Analyst classified features best overall on the SPOT and Landsat imagery. Based on the entire suite of tasks we evaluated, Feature Extraction performed best overall on the Landsat and QuickBird imagery, while hand digitization performed best overall on the SPOT imagery, and eCognition performed worst overall on all three images. Error rates for both area measurements and feature classification were prohibitively high on Landsat imagery, while QuickBird was time and cost prohibitive for
Energy Technology Data Exchange (ETDEWEB)
Bertemann, David [Erlangen-Nuernberg Univ., Erlangen (DE). Lehrstuhl fuer Geologie (Exogene Dynamik); Psyk, Mario [REHAU AG and CO, Erlangen-Eltersdorf (Germany)
2012-07-01
The project ThermoMap funded by the European Commission enables a comprehensive assessment of the near-surface geothermal energy potential from already existing geoscientific data sets. Currently, twelve partners from nine EU Member States are involved.
Energy Technology Data Exchange (ETDEWEB)
Kashiwagi, Toshiya; Suto, Yasushi; Taruya, Atsushi; Yahata, Kazuhiro [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Kayo, Issha [Department of Physics, Toho University, Funabashi, Chiba 274-8510 (Japan); Nishimichi, Takahiro, E-mail: kashiwagi@utap.phys.s.u-tokyo.ac.jp [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan)
2015-02-01
The most widely used Galactic extinction map is constructed assuming that the observed far-infrared (FIR) fluxes come entirely from Galactic dust. According to the earlier suggestion by Yahata et al., we consider how FIR emission of galaxies affects the SFD map. We first compute the surface number density of Sloan Digital Sky Survey (SDSS) DR7 galaxies as a function of the r-band extinction, A {sub r,} {sub SFD}. We confirm that the surface densities of those galaxies positively correlate with A {sub r,} {sub SFD} for A {sub r,} {sub SFD} < 0.1, as first discovered by Yahata et al. for SDSS DR4 galaxies. Next we construct an analytical model to compute the surface density of galaxies, taking into account the contamination of their FIR emission. We adopt a log-normal probability distribution for the ratio of 100 μm and r-band luminosities of each galaxy, y ≡ (νL){sub 100} {sub μm}/(νL) {sub r}. Then we search for the mean and rms values of y that fit the observed anomaly, using the analytical model. The required values to reproduce the anomaly are roughly consistent with those measured from the stacking analysis of SDSS galaxies. Due to the limitation of our statistical modeling, we are not yet able to remove the FIR contamination of galaxies from the extinction map. Nevertheless, the agreement with the model prediction suggests that the FIR emission of galaxies is mainly responsible for the observed anomaly. Whereas the corresponding systematic error in the Galactic extinction map is 0.1-1 mmag, it is directly correlated with galaxy clustering and thus needs to be carefully examined in precision cosmology.
Energy Technology Data Exchange (ETDEWEB)
Stephens, Michael B.; Bergman, Torbjoern (Geological Survey of Sweden, Uppsala (Sweden)); Isaksson, Hans (GeoVista AB, Luleaa (Sweden)); Petersson, Jesper (SwedPower AB, Stockholm (Sweden))
2008-12-15
A description of the bedrock geological map of the ground surface at the Forsmark site is presented here. This map is essentially a 2D model for the distribution of different types of rock unit on this surface. Besides showing the distribution of these rock units, the bedrock geological map also displays the distribution of some deformation zones that intersect the ground surface. It also presents information bearing on the position and form of outcrops, the location and projection of boreholes drilled during the site investigation programme, subordinate rock types, the occurrence of abandoned mines or exploration prospects, measurements of ductile structures in outcrops, inferred form lines, key minerals, and the occurrence of mylonite and cataclastic rock. Bedrock data from outcrops and excavations, airborne and ground magnetic data and information from the uppermost part of boreholes have all been used in the construction of the geological map. The description has also made use of complementary analytical data bearing on the composition and age of the rocks as well gamma-ray spectrometry and gravity data. Uncertainty in the position of the boundaries between rock units over the mapped area are addressed in a qualitative manner. Four model versions of the bedrock geological map have been delivered to SKB's GIS database (bedrock geological map, Forsmark, versions 1.1, 1.2, 2.2 and 2.3) at different times during the site investigation programme. The Forsmark area is situated along the coast of the Baltic Sea in northern Uppland, Sweden, in a region where the overall level of ductile strain in the bedrock is high. This high-strain region extends several tens of kilometres across the WNW-ENE to NW-SE strike of the rocks in this part of the Fennoscandian Shield. At Forsmark, the coastal region is composed partly of high-strain belts, which formed under amphibolite-facies metamorphic conditions, and partly of tectonic lenses, where the bedrock is also affected by
International Nuclear Information System (INIS)
Stephens, Michael B.; Bergman, Torbjoern; Isaksson, Hans; Petersson, Jesper
2008-12-01
A description of the bedrock geological map of the ground surface at the Forsmark site is presented here. This map is essentially a 2D model for the distribution of different types of rock unit on this surface. Besides showing the distribution of these rock units, the bedrock geological map also displays the distribution of some deformation zones that intersect the ground surface. It also presents information bearing on the position and form of outcrops, the location and projection of boreholes drilled during the site investigation programme, subordinate rock types, the occurrence of abandoned mines or exploration prospects, measurements of ductile structures in outcrops, inferred form lines, key minerals, and the occurrence of mylonite and cataclastic rock. Bedrock data from outcrops and excavations, airborne and ground magnetic data and information from the uppermost part of boreholes have all been used in the construction of the geological map. The description has also made use of complementary analytical data bearing on the composition and age of the rocks as well gamma-ray spectrometry and gravity data. Uncertainty in the position of the boundaries between rock units over the mapped area are addressed in a qualitative manner. Four model versions of the bedrock geological map have been delivered to SKB's GIS database (bedrock geological map, Forsmark, versions 1.1, 1.2, 2.2 and 2.3) at different times during the site investigation programme. The Forsmark area is situated along the coast of the Baltic Sea in northern Uppland, Sweden, in a region where the overall level of ductile strain in the bedrock is high. This high-strain region extends several tens of kilometres across the WNW-ENE to NW-SE strike of the rocks in this part of the Fennoscandian Shield. At Forsmark, the coastal region is composed partly of high-strain belts, which formed under amphibolite-facies metamorphic conditions, and partly of tectonic lenses, where the bedrock is also affected by
High-density surface EMG maps from upper-arm and forearm muscles
Directory of Open Access Journals (Sweden)
Rojas-Martínez Monica
2012-12-01
Full Text Available Abstract Background sEMG signal has been widely used in different applications in kinesiology and rehabilitation as well as in the control of human-machine interfaces. In general, the signals are recorded with bipolar electrodes located in different muscles. However, such configuration may disregard some aspects of the spatial distribution of the potentials like location of innervation zones and the manifestation of inhomogineties in the control of the muscular fibers. On the other hand, the spatial distribution of motor unit action potentials has recently been assessed with activation maps obtained from High Density EMG signals (HD-EMG, these lasts recorded with arrays of closely spaced electrodes. The main objective of this work is to analyze patterns in the activation maps, associating them with four movement directions at the elbow joint and with different strengths of those tasks. Although the activation pattern can be assessed with bipolar electrodes, HD-EMG maps could enable the extraction of features that depend on the spatial distribution of the potentials and on the load-sharing between muscles, in order to have a better differentiation between tasks and effort levels. Methods An experimental protocol consisting of isometric contractions at three levels of effort during flexion, extension, supination and pronation at the elbow joint was designed and HD-EMG signals were recorded with 2D electrode arrays on different upper-limb muscles. Techniques for the identification and interpolation of artifacts are explained, as well as a method for the segmentation of the activation areas. In addition, variables related to the intensity and spatial distribution of the maps were obtained, as well as variables associated to signal power of traditional single bipolar recordings. Finally, statistical tests were applied in order to assess differences between information extracted from single bipolar signals or from HD-EMG maps and to analyze
Lai, Dakun; Sun, Jian; Li, Yigang; He, Bin
2013-06-01
As radio frequency (RF) catheter ablation becomes increasingly prevalent in the management of ventricular arrhythmia in patients, an accurate and rapid determination of the arrhythmogenic site is of important clinical interest. The aim of this study was to test the hypothesis that the inversely reconstructed ventricular endocardial current density distribution from body surface potential maps (BSPMs) can localize the regions critical for maintenance of a ventricular ectopic activity. Patients with isolated and monomorphic premature ventricular contractions (PVCs) were investigated by noninvasive BSPMs and subsequent invasive catheter mapping and ablation. Equivalent current density (CD) reconstruction (CDR) during symptomatic PVCs was obtained on the endocardial ventricular surface in six patients (four men, two women, years 23-77), and the origin of the spontaneous ectopic activity was localized at the location of the maximum CD value. Compared with the last (successful) ablation site (LAS), the mean and standard deviation of localization error of the CDR approach were 13.8 and 1.3 mm, respectively. In comparison, the distance between the LASs and the estimated locations of an equivalent single moving dipole in the heart was 25.5 ± 5.5 mm. The obtained CD distribution of activated sources extending from the catheter ablation site also showed a high consistency with the invasively recorded electroanatomical maps. The noninvasively reconstructed endocardial CD distribution is suitable to predict a region of interest containing or close to arrhythmia source, which may have the potential to guide RF catheter ablation.
D'Amore, M.; Le Scaon, R.; Helbert, J.; Maturilli, A.
2017-12-01
Machine-learning achieved unprecedented results in high-dimensional data processing tasks with wide applications in various fields. Due to the growing number of complex nonlinear systems that have to be investigated in science and the bare raw size of data nowadays available, ML offers the unique ability to extract knowledge, regardless the specific application field. Examples are image segmentation, supervised/unsupervised/ semi-supervised classification, feature extraction, data dimensionality analysis/reduction.The MASCS instrument has mapped Mercury surface in the 400-1145 nm wavelength range during orbital observations by the MESSENGER spacecraft. We have conducted k-means unsupervised hierarchical clustering to identify and characterize spectral units from MASCS observations. The results display a dichotomy: a polar and equatorial units, possibly linked to compositional differences or weathering due to irradiation. To explore possible relations between composition and spectral behavior, we have compared the spectral provinces with elemental abundance maps derived from MESSENGER's X-Ray Spectrometer (XRS).For the Vesta application on DAWN Visible and infrared spectrometer (VIR) data, we explored several Machine Learning techniques: image segmentation method, stream algorithm and hierarchical clustering.The algorithm successfully separates the Olivine outcrops around two craters on Vesta's surface [1]. New maps summarizing the spectral and chemical signature of the surface could be automatically produced.We conclude that instead of hand digging in data, scientist could choose a subset of algorithms with well known feature (i.e. efficacy on the particular problem, speed, accuracy) and focus their effort in understanding what important characteristic of the groups found in the data mean. [1] E Ammannito et al. "Olivine in an unexpected location on Vesta's surface". In: Nature 504.7478 (2013), pp. 122-125.
Energy Technology Data Exchange (ETDEWEB)
Plomp, M; Malkin, A J
2008-06-02
Atomic force microscopy provides a unique capability to image high-resolution architecture and structural dynamics of pathogens (e.g. viruses, bacteria and bacterial spores) at near molecular resolution in native conditions. Further development of atomic force microscopy in order to enable the correlation of pathogen protein surface structures with specific gene products is essential to understand the mechanisms of the pathogen life cycle. We have applied an AFM-based immunolabeling technique for the proteomic mapping of macromolecular structures through the visualization of the binding of antibodies, conjugated with nanogold particles, to specific epitopes on Bacillus spore surfaces. This information is generated while simultaneously acquiring the surface morphology of the pathogen. The immunospecificity of this labeling method was established through the utilization of specific polyclonal and monoclonal antibodies that target spore coat and exosporium epitopes of Bacillus atrophaeus and Bacillus anthracis spores.
Algebraic methods in random matrices and enumerative geometry
Eynard, Bertrand
2008-01-01
We review the method of symplectic invariants recently introduced to solve matrix models loop equations, and further extended beyond the context of matrix models. For any given spectral curve, one defined a sequence of differential forms, and a sequence of complex numbers Fg . We recall the definition of the invariants Fg, and we explain their main properties, in particular symplectic invariance, integrability, modularity,... Then, we give several example of applications, in particular matrix models, enumeration of discrete surfaces (maps), algebraic geometry and topological strings, non-intersecting brownian motions,...
Institute of Scientific and Technical Information of China (English)
YIN Ya-jun; WU Ji-ye; HUANG Ke-zhi; FAN Qin-shan
2008-01-01
By combining of the second gradient operator, the second class of integral theorems, the Gaussian-curvature-based integral theorems and the Gaussian (or spherical) mapping, a series of invariants or geometric conservation quantities under Gaussian (or spherical) mapping are revealed. From these mapping invariants important transformations between original curved surface and the spherical surface are derived. The potential applications of these invariants and transformations to geometry are discussed.
Mapping surface flow in low gradient areas with thermal remote sensing
DEFF Research Database (Denmark)
Prinds, Christian; Petersen, Rasmus Jes; Greve, Mogens Humlekrog
of drainage input into the buffer system and 2) the flow path of the water. The TIR imagery was collected by a UAV (eBee from SenseFly) with a thermal camera (ThermoMap from SenseFly) at early spring in 2016 and 2017. The surveys are conducted in cold periods where discharging drainage water (and groundwater...
New geometries for black hole horizons
Energy Technology Data Exchange (ETDEWEB)
Armas, Jay [Physique Théorique et Mathématique,Université Libre de Bruxelles and International Solvay Institutes, ULB-Campus Plaine CP231, B-1050 Brussels (Belgium); Blau, Matthias [Albert Einstein Center for Fundamental Physics, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland)
2015-07-10
We construct several classes of worldvolume effective actions for black holes by integrating out spatial sections of the worldvolume geometry of asymptotically flat black branes. This provides a generalisation of the blackfold approach for higher-dimensional black holes and yields a map between different effective theories, which we exploit by obtaining new hydrodynamic and elastic transport coefficients via simple integrations. Using Euclidean minimal surfaces in order to decouple the fluid dynamics on different sections of the worldvolume, we obtain local effective theories for ultraspinning Myers-Perry branes and helicoidal black branes, described in terms of a stress-energy tensor, particle currents and non-trivial boost vectors. We then study in detail and present novel compact and non-compact geometries for black hole horizons in higher-dimensional asymptotically flat space-time. These include doubly-spinning black rings, black helicoids and helicoidal p-branes as well as helicoidal black rings and helicoidal black tori in D≥6.
Chabrillat, Sabine; Foerster, Saskia; Steinberg, Andreas; Stevens, Antoine; Segl, Karl
2016-04-01
There is a renewed awareness of the finite nature of the world's soil resources, growing concern about soil security, and significant uncertainties about the carrying capacity of the planet. As a consequence, soil scientists are being challenged to provide regular assessments of soil conditions from local through to global scales. However, only a few countries have the necessary survey and monitoring programs to meet these new needs and existing global data sets are out-of-date. A particular issue is the clear demand for a new area-wide regional to global coverage with accurate, up-to-date, and spatially referenced soil information as expressed by the modeling scientific community, farmers and land users, and policy and decision makers. Soil spectroscopy from remote sensing observations based on studies from the laboratory scale to the airborne scale has been shown to be a proven method for the quantitative prediction of key soil surface properties in local areas for exposed soils in appropriate surface conditions such as low vegetation cover and low water content. With the upcoming launch of the next generation of hyperspectral satellite sensors in the next 3 to 5 years (EnMAP, HISUI, PRISMA, SHALOM), a great potential for the global mapping and monitoring of soil properties is appearing. Nevertheless, the capabilities to extend the soil properties current spectral modeling from local to regional scales are still to be demonstrated using robust methods. In particular, three central questions are at the forefront of research nowadays: a) methodological developments toward improved algorithms and operational tools for the extraction of soil properties, b) up scaling from the laboratory into space domain, and c) demonstration of the potential of upcoming satellite systems and expected accuracy of soil maps. In this study, airborne imaging spectroscopy data from several test sites are used to simulate EnMAP satellite images at 30 m scale. Then, different soil
Mwakanyamale, Kisa; Day-Lewis, Frederick D.; Slater, Lee D.
2013-01-01
Fiber-optic distributed temperature sensing (FO-DTS) increasingly is used to map zones of focused groundwater/surface-water exchange (GWSWE). Previous studies of GWSWE using FO-DTS involved identification of zones of focused GWSWE based on arbitrary cutoffs of FO-DTS time-series statistics (e.g., variance, cross-correlation between temperature and stage, or spectral power). New approaches are needed to extract more quantitative information from large, complex FO-DTS data sets while concurrently providing an assessment of uncertainty associated with mapping zones of focused GSWSE. Toward this end, we present a strategy combining discriminant analysis (DA) and spectral analysis (SA). We demonstrate the approach using field experimental data from a reach of the Columbia River adjacent to the Hanford 300 Area site. Results of the combined SA/DA approach are shown to be superior to previous results from qualitative interpretation of FO-DTS spectra alone.
Zhang, Geli; Xiao, Xiangming; Dong, Jinwei; Kou, Weili; Jin, Cui; Qin, Yuanwei; Zhou, Yuting; Wang, Jie; Menarguez, Michael Angelo; Biradar, Chandrashekhar
2015-08-01
Knowledge of the area and spatial distribution of paddy rice is important for assessment of food security, management of water resources, and estimation of greenhouse gas (methane) emissions. Paddy rice agriculture has expanded rapidly in northeastern China in the last decade, but there are no updated maps of paddy rice fields in the region. Existing algorithms for identifying paddy rice fields are based on the unique physical features of paddy rice during the flooding and transplanting phases and use vegetation indices that are sensitive to the dynamics of the canopy and surface water content. However, the flooding phenomena in high latitude area could also be from spring snowmelt flooding. We used land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to determine the temporal window of flooding and rice transplantation over a year to improve the existing phenology-based approach. Other land cover types (e.g., evergreen vegetation, permanent water bodies, and sparse vegetation) with potential influences on paddy rice identification were removed (masked out) due to their different temporal profiles. The accuracy assessment using high-resolution images showed that the resultant MODIS-derived paddy rice map of northeastern China in 2010 had a high accuracy (producer and user accuracies of 92% and 96%, respectively). The MODIS-based map also had a comparable accuracy to the 2010 Landsat-based National Land Cover Dataset (NLCD) of China in terms of both area and spatial pattern. This study demonstrated that our improved algorithm by using both thermal and optical MODIS data, provides a robust, simple and automated approach to identify and map paddy rice fields in temperate and cold temperate zones, the northern frontier of rice planting.
Geometry Dependence of Stellarator Turbulence
International Nuclear Information System (INIS)
Mynick, H.E.; Xanthopoulos, P.; Boozer, A.H.
2009-01-01
Using the nonlinear gyrokinetic code package GENE/GIST, we study the turbulent transport in a broad family of stellarator designs, to understand the geometry-dependence of the microturbulence. By using a set of flux tubes on a given flux surface, we construct a picture of the 2D structure of the microturbulence over that surface, and relate this to relevant geometric quantities, such as the curvature, local shear, and effective potential in the Schrodinger-like equation governing linear drift modes
Martínez, G.; Vanderlinden, K.; Giraldez, J. V.; Espejo, A. J.; Muriel, J. L.
2009-12-01
Soil moisture plays an important role in a wide variety of biogeochemical fluxes in the soil-plant-atmosphere system and governs the (eco)hydrological response of a catchment to an external forcing such as rainfall. Near-surface electromagnetic induction (EMI) sensors that measure the soil apparent electrical conductivity (ECa) provide a fast and non-invasive means for characterizing this response at the field or catchment scale through high-resolution time-lapse mapping. Here we show how ECa maps, obtained before and after an intense rainfall event of 125 mm h-1, elucidate differences in soil moisture patterns and hydrologic response of an experimental field as a consequence of differed soil management. The dryland field (Vertisol) was located in SW Spain and cropped with a typical wheat-sunflower-legume rotation. Both, near-surface and subsurface ECa (ECas and ECad, respectively), were measured using the EM38-DD EMI sensor in a mobile configuration. Raw ECa measurements and Mean Relative Differences (MRD) provided information on soil moisture patterns while time-lapse maps were used to evaluate the hydrologic response of the field. ECa maps of the field, measured before and after the rainfall event showed similar patterns. The field depressions where most of water and sediments accumulated had the highest ECa and MRD values. The SE-oriented soil, which was deeper and more exposed to sun and wind, showed the lowest ECa and MRD. The largest differences raised in the central part of the field where a high ECa and MRD area appeared after the rainfall event as a consequence of the smaller soil depth and a possible subsurface flux concentration. Time-lapse maps of both ECa and MRD were also similar. The direct drill plots showed higher increments of ECa and MRD as a result of the smaller runoff production. Time-lapse ECa increments showed a bimodal distribution differentiating clearly the direct drill from the conventional and minimum tillage plots. However this kind
Lambot, S.; Minet, J.; Slob, E.; Vereecken, H.; Vanclooster, M.
2008-12-01
Measuring soil surface water content is essential in hydrology and agriculture as this variable controls important key processes of the hydrological cycle such as infiltration, runoff, evaporation, and energy exchanges between the earth and the atmosphere. We present a ground-penetrating radar (GPR) method for automated, high-resolution, real-time mapping of soil surface dielectric permittivity and correlated water content at the field scale. Field scale characterization and monitoring is not only necessary for field scale management applications, but also for unravelling upscaling issues in hydrology and bridging the scale gap between local measurements and remote sensing. In particular, such methods are necessary to validate and improve remote sensing data products. The radar system consists of a vector network analyzer combined with an off-ground, ultra-wideband monostatic horn antenna, thereby setting up a continuous-wave steeped-frequency GPR. Radar signal analysis is based on three-dimensional electromagnetic inverse modelling. The forward model accounts for all antenna effects, antenna-soil interactions, and wave propagation in three-dimensional multilayered media. A fast procedure was developed to evaluate the involved Green's function, resulting from a singular, complex integral. Radar data inversion is focused on the surface reflection in the time domain. The method presents considerable advantages compared to the current surface characterization methods using GPR, namely, the ground wave and common reflection methods. Theoretical analyses were performed, dealing with the effects of electric conductivity on the surface reflection when non-negligible, and on near-surface layering, which may lead to unrealistic values for the surface dielectric permittivity if not properly accounted for. Inversion strategies are proposed. In particular the combination of GPR with electromagnetic induction data appears to be promising to deal with highly conductive soils
Mapping wetlands and surface water in the Prairie Pothole Region of North America: Chapter 16
Rover, Jennifer R.; Mushet, David M.
2015-01-01
The Prairie Pothole Region (PPR) is one of the most highly productive wetland regions in the world. Prairie Pothole wetlands serve as a primary feeding and breeding habitat for more than one-half of North America’s waterfowl population, as well as a variety of songbirds, waterbirds, shorebirds, and other wildlife. During the last century, extensive land conversions from grassland with wetlands to cultivated cropland and grazed pastureland segmented and reduced wetland habitat. Inventorying and characterizing remaining wetland habitat is critical for the management of wetland ecosystem services. Remote sensing technologies are often utilized for mapping and monitoring wetlands. This chapter presents background specific to the PPR and discusses approaches employed in mapping its wetlands before presenting a case study.
Bonacuse, Peter J.; Kantzos, Peter T.
2002-01-01
An automated two-degree-of-freedom specimen positioning stage has been developed at the NASA Glenn Research Center to map and monitor defects in fatigue specimens. This system expedites the examination of the entire gauge section of fatigue specimens so that defects can be found using scanning electron microscopy (SEM). Translation and rotation stages are driven by microprocessor-based controllers that are, in turn, interfaced to a computer running custom-designed software. This system is currently being used to find and record the location of ceramic inclusions in powder metallurgy materials. The mapped inclusions are periodically examined during interrupted fatigue experiments. The number of cycles to initiate cracks from these inclusions and the rate of growth of initiated cracks can then be quantified. This information is necessary to quantify the effect of this type of defect on the durability of powder metallurgy materials. This system was developed with support of the Ultra Safe program.
Mapping atomic contact between pentacene and a Au surface using scanning tunneling spectroscopy.
Song, Young Jae; Lee, Kyuho; Kim, Seong Heon; Choi, Byoung-Young; Yu, Jaejun; Kuk, Young
2010-03-10
We mapped spatially varying intramolecular electronic structures on a pentacene-gold interface using scanning tunneling spectroscopy. Along with ab initio calculations based on density functional theory, we found that the directional nature of the d orbitals of Au atoms plays an important role in the interaction at the pentacene-gold contact. The gold-induced interface states are broadened and shifted by various pentacene-gold distances determined by the various registries of a pentacene molecule on a gold substrate.
Mapping surface tension induced menisci with application to tensiometry and refractometry.
Mishra, Avanish; Kulkarni, Varun; Khor, Jian-Wei; Wereley, Steve
2015-07-28
In this work, we discuss an optical method for measuring surface tension induced menisci. The principle of measurement is based upon the change in the background pattern produced by the curvature of the meniscus acting as a lens. We measure the meniscus profile over an inclined glass plate and utilize the measured meniscus for estimation of surface tension and refractive index.
Krabbenborg, Sven; Nicosia, Carlo; Chen, P.; Huskens, Jurriaan
2013-01-01
Studying and controlling reactions at surfaces is of great fundamental and applied interest in, among others, biology, electronics and catalysis. Because reaction kinetics is different at surfaces compared with solution, frequently, solution-characterization techniques cannot be used. Here we report
Moho map of South America from receiver functions and surface waves
Lloyd, Simon; van der Lee, Suzan; FrançA, George Sand; AssumpçãO, Marcelo; Feng, Mei
2010-11-01
We estimate crustal structure and thickness of South America north of roughly 40°S. To this end, we analyzed receiver functions from 20 relatively new temporary broadband seismic stations deployed across eastern Brazil. In the analysis we include teleseismic and some regional events, particularly for stations that recorded few suitable earthquakes. We first estimate crustal thickness and average Poisson's ratio using two different stacking methods. We then combine the new crustal constraints with results from previous receiver function studies. To interpolate the crustal thickness between the station locations, we jointly invert these Moho point constraints, Rayleigh wave group velocities, and regional S and Rayleigh waveforms for a continuous map of Moho depth. The new tomographic Moho map suggests that Moho depth and Moho relief vary slightly with age within the Precambrian crust. Whether or not a positive correlation between crustal thickness and geologic age is derived from the pre-interpolation point constraints depends strongly on the selected subset of receiver functions. This implies that using only pre-interpolation point constraints (receiver functions) inadequately samples the spatial variation in geologic age. The new Moho map also reveals an anomalously deep Moho beneath the oldest core of the Amazonian Craton.
DEFF Research Database (Denmark)
Yang, Jaeyoung; Palla, Mirko; Bosco, Filippo
2013-01-01
Surface-enhanced Raman spectroscopy (SERS) has been used in a variety of biological applications due to its high sensitivity and specificity. Here, we report a SERS-based biosensing approach for quantitative detection of biomolecules. A SERS substrate bearing gold-decorated silicon nanopillars......-to-spot variation in conventional SERS quantification. Furthermore, we have developed an analytical model capable of predicting experimental intensity distributions on the substrates for reliable quantification of biomolecules. Lastly, we have calculated the minimum needed area of Raman mapping for efficient...
Lectures on Algebraic Geometry I
Harder, Gunter
2012-01-01
This book and the following second volume is an introduction into modern algebraic geometry. In the first volume the methods of homological algebra, theory of sheaves, and sheaf cohomology are developed. These methods are indispensable for modern algebraic geometry, but they are also fundamental for other branches of mathematics and of great interest in their own. In the last chapter of volume I these concepts are applied to the theory of compact Riemann surfaces. In this chapter the author makes clear how influential the ideas of Abel, Riemann and Jacobi were and that many of the modern metho
Marutschke, Christoph; Walters, Deron; Walters, Deron; Hermes, Ilka; Bechstein, Ralf; Kühnle, Angelika
2014-08-22
Calcite, the most stable modification of calcium carbonate, is a major mineral in nature. It is, therefore, highly relevant in a broad range of fields such as biomineralization, sea water desalination and oil production. Knowledge of the surface structure and reactivity of the most stable cleavage plane, calcite (10.4), is pivotal for understanding the role of calcite in these diverse areas. Given the fact that most biological processes and technical applications take place in an aqueous environment, perhaps the most basic - yet decisive - question addresses the interaction of water molecules with the calcite (10.4) surface. In this work, amplitude modulation atomic force microscopy is used for three-dimensional (3D) mapping of the surface structure and the hydration layers above the surface. An easy-to-use scanning protocol is implemented for collecting reliable 3D data. We carefully discuss a comprehensible criterion for identifying the solid-liquid interface within our data. In our data three hydration layers form a characteristic pattern that is commensurate with the underlying calcite surface.
International Nuclear Information System (INIS)
Marutschke, Christoph; Hermes, Ilka; Bechstein, Ralf; Kühnle, Angelika; Walters, Deron; Cleveland, Jason
2014-01-01
Calcite, the most stable modification of calcium carbonate, is a major mineral in nature. It is, therefore, highly relevant in a broad range of fields such as biomineralization, sea water desalination and oil production. Knowledge of the surface structure and reactivity of the most stable cleavage plane, calcite (10.4), is pivotal for understanding the role of calcite in these diverse areas. Given the fact that most biological processes and technical applications take place in an aqueous environment, perhaps the most basic—yet decisive—question addresses the interaction of water molecules with the calcite (10.4) surface. In this work, amplitude modulation atomic force microscopy is used for three-dimensional (3D) mapping of the surface structure and the hydration layers above the surface. An easy-to-use scanning protocol is implemented for collecting reliable 3D data. We carefully discuss a comprehensible criterion for identifying the solid–liquid interface within our data. In our data three hydration layers form a characteristic pattern that is commensurate with the underlying calcite surface. (paper)
Pizarro, Patricia; Ferrarese, Francesco; Loddo, Donato; Eugenio Pappalardo, Salvatore; Varotto, Mauro
2016-04-01
Intensive cropping systems today represent a paramount issue in terms of environmental impacts, since agricultural pollutants can constitute a potential threat to surface water, non-target organisms and aquatic ecosystems. Levels of pesticide concentrations in surface waters are indeed unquestionably correlated to crop and soil management practices at field-scale. Due to the numerous applications of pesticides required, orchards and vineyards can represent relevant non-point sources for pesticide contamination of water bodies, mainly prompted by soil erosion, surface runoff and spray drift. To reduce risks of pesticide contamination of surface water, the Directive 2009/128/CET imposed the local implementation of agricultural good practices and mitigation actions such as the use of vegetative buffer filter strips and hedgerows along river and pond banks. However, implementation of mitigation actions is often difficult, especially in extremely fragmented agricultural landscapes characterized by a complex territorial matrix set up on urban sprawling, frequent surface water bodies, important geomorphological processes and protected natural areas. Typically, such landscape matrix is well represented by the, Prosecco-DOCG vineyards area (NE of Italy, Province of Treviso) which lays on hogback hills of conglomerate, marls and sandstone that ranges between 50 and 500 m asl. Moreover such vineyards landscape is characterized by traditional and non-traditional agricultural terraces The general aim of this paper is to identify areas of surface water bodies with high potential risk of pesticide contamination from surrounding vineyards in the 735 ha of Lierza river basin (Refrontolo, TV), one of the most representative terraced landscape of the Prosecco-DOCG area. Specific aims are i) mapping terraced Prosecco-DOCG vineyards, ii) classifying potential risk from pesticide of the different areas. Remote sensing technologies such as four bands aerial photos (RGB+NIR) and Light
Schwartz, Richard Evan
2011-01-01
This book presents a number of topics related to surfaces, such as Euclidean, spherical and hyperbolic geometry, the fundamental group, universal covering surfaces, Riemannian manifolds, the Gauss-Bonnet Theorem, and the Riemann mapping theorem. The main idea is to get to some interesting mathematics without too much formality. The book also includes some material only tangentially related to surfaces, such as the Cauchy Rigidity Theorem, the Dehn Dissection Theorem, and the Banach-Tarski Theorem. The goal of the book is to present a tapestry of ideas from various areas of mathematics in a clear and rigorous yet informal and friendly way. Prerequisites include undergraduate courses in real analysis and in linear algebra, and some knowledge of complex analysis.
Meyer, Walter J
2006-01-01
Meyer''s Geometry and Its Applications, Second Edition, combines traditional geometry with current ideas to present a modern approach that is grounded in real-world applications. It balances the deductive approach with discovery learning, and introduces axiomatic, Euclidean geometry, non-Euclidean geometry, and transformational geometry. The text integrates applications and examples throughout and includes historical notes in many chapters. The Second Edition of Geometry and Its Applications is a significant text for any college or university that focuses on geometry''s usefulness in other disciplines. It is especially appropriate for engineering and science majors, as well as future mathematics teachers.* Realistic applications integrated throughout the text, including (but not limited to): - Symmetries of artistic patterns- Physics- Robotics- Computer vision- Computer graphics- Stability of architectural structures- Molecular biology- Medicine- Pattern recognition* Historical notes included in many chapters...
International Nuclear Information System (INIS)
Sloane, Peter
2007-01-01
We adapt the spinorial geometry method introduced in [J. Gillard, U. Gran and G. Papadopoulos, 'The spinorial geometry of supersymmetric backgrounds,' Class. Quant. Grav. 22 (2005) 1033 [ (arXiv:hep-th/0410155)
Energy Technology Data Exchange (ETDEWEB)
Sloane, Peter [Department of Mathematics, King' s College, University of London, Strand, London WC2R 2LS (United Kingdom)
2007-09-15
We adapt the spinorial geometry method introduced in [J. Gillard, U. Gran and G. Papadopoulos, 'The spinorial geometry of supersymmetric backgrounds,' Class. Quant. Grav. 22 (2005) 1033 [ (arXiv:hep-th/0410155)
Flinchum, B. A.; Holbrook, W. S.; Grana, D.; Parsekian, A.; Carr, B.; Jiao, J.
2017-12-01
Porosity is generated by chemical, physical and biological processes that work to transform bedrock into soil. The resulting porosity structure can provide specifics about these processes and can improve understanding groundwater storage in the deep critical zone. Near-surface geophysical methods, when combined with rock physics and drilling, can be a tool used to map porosity over large spatial scales. In this study, we estimate porosity in three-dimensions (3D) across a 58 Ha granite catchment. Observations focus on seismic refraction, downhole nuclear magnetic resonance logs, downhole sonic logs, and samples of core acquired by push coring. We use a novel petrophysical approach integrating two rock physics models, a porous medium for the saprolite and a differential effective medium for the fractured rock, that drive a Bayesian inversion to calculate porosity from seismic velocities. The inverted geophysical porosities are within about 0.05 m3/m3 of lab measured values. We extrapolate the porosity estimates below seismic refraction lines to a 3D volume using ordinary kriging to map the distribution of porosity in 3D up to depths of 80 m. This study provides a unique map of porosity on scale never-before-seen in critical zone science. Estimating porosity on these large spatial scales opens the door for improving and understanding the processes that shape the deep critical zone.
The Geometry of the Universe: Part 2
Francis, Stephanie
2009-01-01
Hyperbolic geometry occurs on hyperbolic planes--the most commonly cited one being a saddle shape. In this article, the author explores negative hyperbolic curvature, and provides a detailed description of how she constructed two hyperbolic paraboloids. Hyperbolic geometry occurs on surfaces that have negative curvature. (Contains 11 figures and 4…
Mapping the Qademah Fault with Traveltime, Surface-wave, and Resistivity Tomograms
Hanafy, Sherif M.
2015-08-19
Traveltime, surface-wave, and resistivity tomograms are used to track the buried Qademah fault located near King Abdullah Economic City (KAEC), Saudi Arabia. The fault location is confirmed by the 1) resistivity tomogram obtained from an electrical resistivity experiment, 2) the refraction traveltime tomogram, 3) the reflection image computed from 2D seismic data set recorded at the northern part of the fault, and 4) the surface-wave tomogram.
Mapping the Qademah Fault with Traveltime, Surface-wave, and Resistivity Tomograms
Hanafy, Sherif M.
2015-01-01
Traveltime, surface-wave, and resistivity tomograms are used to track the buried Qademah fault located near King Abdullah Economic City (KAEC), Saudi Arabia. The fault location is confirmed by the 1) resistivity tomogram obtained from an electrical resistivity experiment, 2) the refraction traveltime tomogram, 3) the reflection image computed from 2D seismic data set recorded at the northern part of the fault, and 4) the surface-wave tomogram.
Busemann, Herbert
2008-01-01
This exploration of convex surfaces focuses on extrinsic geometry and applications of the Brunn-Minkowski theory. It also examines intrinsic geometry and the realization of intrinsic metrics. 1958 edition.
Guide to Computational Geometry Processing
DEFF Research Database (Denmark)
Bærentzen, Jakob Andreas; Gravesen, Jens; Anton, François
be processed before it is useful. This Guide to Computational Geometry Processing reviews the algorithms for processing geometric data, with a practical focus on important techniques not covered by traditional courses on computer vision and computer graphics. This is balanced with an introduction...... to the theoretical and mathematical underpinnings of each technique, enabling the reader to not only implement a given method, but also to understand the ideas behind it, its limitations and its advantages. Topics and features: Presents an overview of the underlying mathematical theory, covering vector spaces......, metric space, affine spaces, differential geometry, and finite difference methods for derivatives and differential equations Reviews geometry representations, including polygonal meshes, splines, and subdivision surfaces Examines techniques for computing curvature from polygonal meshes Describes...
Machine learning spatial geometry from entanglement features
You, Yi-Zhuang; Yang, Zhao; Qi, Xiao-Liang
2018-02-01
Motivated by the close relations of the renormalization group with both the holography duality and the deep learning, we propose that the holographic geometry can emerge from deep learning the entanglement feature of a quantum many-body state. We develop a concrete algorithm, call the entanglement feature learning (EFL), based on the random tensor network (RTN) model for the tensor network holography. We show that each RTN can be mapped to a Boltzmann machine, trained by the entanglement entropies over all subregions of a given quantum many-body state. The goal is to construct the optimal RTN that best reproduce the entanglement feature. The RTN geometry can then be interpreted as the emergent holographic geometry. We demonstrate the EFL algorithm on a 1D free fermion system and observe the emergence of the hyperbolic geometry (AdS3 spatial geometry) as we tune the fermion system towards the gapless critical point (CFT2 point).
Special metrics and group actions in geometry
Fino, Anna; Musso, Emilio; Podestà, Fabio; Vezzoni, Luigi
2017-01-01
The volume is a follow-up to the INdAM meeting “Special metrics and quaternionic geometry” held in Rome in November 2015. It offers a panoramic view of a selection of cutting-edge topics in differential geometry, including 4-manifolds, quaternionic and octonionic geometry, twistor spaces, harmonic maps, spinors, complex and conformal geometry, homogeneous spaces and nilmanifolds, special geometries in dimensions 5–8, gauge theory, symplectic and toric manifolds, exceptional holonomy and integrable systems. The workshop was held in honor of Simon Salamon, a leading international scholar at the forefront of academic research who has made significant contributions to all these subjects. The articles published here represent a compelling testimony to Salamon’s profound and longstanding impact on the mathematical community. Target readership includes graduate students and researchers working in Riemannian and complex geometry, Lie theory and mathematical physics.
Piman, T.; Schellekens, J.; Haag, A.; Donchyts, G.; Apirumanekul, C.; Hlaing, K. T.
2017-12-01
River morphology changes is one of the key issues in Ayeyarwady River in Myanmar which cause impacts on navigation, riverine habitats, agriculture lands, communities and livelihoods near the bank of the river. This study is aimed to track the changes in river morphology in the middle reach of Ayeyarwady River over last 30 years from 1984-2014 to improve understanding of riverbank dynamic, erosion and deposition procress. Earth observations including LandSat-7, LandSat-8, Digital Elevation Model from SRTM Plus and, ASTER-2 GoogleMap and Open Street Map were obtained for the study. GIS and remote sensing tools were used to analyze changes in river morphology while surface water mapping tool was applied to determine how the dynamic behaviour of the surface river and effect of river morphology changes. The tool consists of two components: (1) a Google Earth Engine (GEE) javascript or python application that performs image analysis and (2) a user-friendly site/app using Google's appspot.com that exposes the application to the users. The results of this study shown that the fluvial morphology in the middle reach of Ayeyarwady River is continuously changing under the influence of high water flows in particularly from extreme flood events and land use change from mining and deforestation. It was observed that some meandering sections of the riverbank were straightened, which results in the movement of sediment downstream and created new sections of meandering riverbank. Several large islands have formed due to the stabilization by vegetation and is enforced by sedimentation while many small bars were formed and migrated dynamically due to changes in water levels and flow velocity in the wet and dry seasons. The main channel was changed to secondary channel in some sections of the river. This results a constant shift of the navigation route. We also found that some villages were facing riverbank erosion which can force villagers to relocate. The study results demonstrated
Denny, J. F.; O'Brien, T. F.; Bergeron, E.; Twichell, D.; Worley, C. R.; Danforth, W. W.; Andrews, B. A.; Irwin, B.
2006-12-01
The U.S. Geological Survey (USGS) has been heavily involved in geological mapping of the seafloor since the 1970s. Early mapping efforts such as GLORIA provided broad-scale imagery of deep waters (depths > 400 meters) within the Exclusive Economic Zone (EEZ). In the early 1990's, the USGS research emphasis shifted from deep- to shallow-water environments (inner continental shelf, nearshore, estuaries) to address pertinent coastal issues such as erosion, sediment availability, sediment transport, vulnerability of coastal areas to natural and anthropogenic hazards, and resource management. Geologic framework mapping in these shallow- water environments has provided valuable data used to 1) define modern sediment distribution and thickness, 2) determine underlying stratigraphic and structural controls on shoreline behavior, and 3) enable onshore-to- offshore geologic mapping within the coastal zone when coupled with subaerial techniques such as GPR and topographic LIDAR. Research in nearshore areas presents technological challenges due to the dynamics of the environment, high volume of data collected, and the geophysical limitations of operating in very shallow water. In 2004, the USGS, in collaboration with NOAA's Coastal Services Center, began a multi-year seafloor mapping effort to better define oyster habitats within Apalachicola Bay, Florida, a shallow water estuary along the northern Gulf of Mexico. The bay poses a technological challenge due to its shallow depths (turbidity that prohibits the use of bathymetric LIDAR. To address this extreme shallow water setting, the USGS incorporated an Autonomous Surface Vessel (ASV) into seafloor mapping operations, in June 2006. The ASV is configured with a chirp sub-bottom profiler (4 24 kHz), dual-frequency chirp sidescan-sonar (100/500 kHz), single-beam echosounder (235 kHz), and forward-looking digital camera, and will be used to delineate the distribution and thickness of surficial sediment, presence of oyster beds
Directory of Open Access Journals (Sweden)
Márcio Luiz da Silva
2013-10-01
Full Text Available Peatlands are soil environments that store carbon and large amounts of water, due to their composition (90 % water, low hydraulic conductivity and a sponge-like behavior. It is estimated that peat bogs cover approximately 4.2 % of the Earth's surface and stock 28.4 % of the soil carbon of the planet. Approximately 612 000 ha of peatlands have been mapped in Brazil, but the peat bogs in the Serra do Espinhaço Meridional (SdEM were not included. The objective of this study was to map the peat bogs of the northern part of the SdEM and estimate the organic matter pools and water volume they stock. The peat bogs were pre-identified and mapped by GIS and remote sensing techniques, using ArcGIS 9.3, ENVI 4.5 and GPS Track Maker Pro software and the maps validated in the field. Six peat bogs were mapped in detail (1:20,000 and 1:5,000 by transects spaced 100 m and each transect were determined every 20 m, the UTM (Universal Transverse Mercator coordinates, depth and samples collected for characterization and determination of organic matter, according to the Brazilian System of Soil Classification. In the northern part of SdEM, 14,287.55 ha of peatlands were mapped, distributed over 1,180,109 ha, representing 1.2 % of the total area. These peatlands have an average volume of 170,021,845.00 m³ and stock 6,120,167 t (428.36 t ha-1 of organic matter and 142,138,262 m³ (9,948 m³ ha-1 of water. In the peat bogs of the Serra do Espinhaço Meridional, advanced stages of decomposing (sapric organic matter predominate, followed by the intermediate stage (hemic. The vertical growth rate of the peatlands ranged between 0.04 and 0.43 mm year-1, while the carbon accumulation rate varied between 6.59 and 37.66 g m-2 year-1. The peat bogs of the SdEM contain the headwaters of important water bodies in the basins of the Jequitinhonha and San Francisco Rivers and store large amounts of organic carbon and water, which is the reason why the protection and preservation
Geometric Transformations in Engineering Geometry
Directory of Open Access Journals (Sweden)
I. F. Borovikov
2015-01-01
Full Text Available Recently, for business purposes, in view of current trends and world experience in training engineers, research and faculty staff there has been a need to transform traditional courses of descriptive geometry into the course of engineering geometry in which the geometrical transformations have to become its main section. On the basis of critical analysis the paper gives suggestions to improve a presentation technique of this section both in the classroom and in academic literature, extend an application scope of geometrical transformations to solve the position and metric tasks and simulation of surfaces, as well as to design complex engineering configurations, which meet a number of pre-specified conditions.The article offers to make a number of considerable amendments to the terms and definitions used in the existing courses of descriptive geometry. It draws some conclusions and makes the appropriate proposals on feasibility of coordination in teaching the movement transformation in the courses of analytical and descriptive geometry. This will provide interdisciplinary team teaching and allow students to be convinced that a combination of analytical and graphic ways to solve geometric tasks is useful and reasonable.The traditional sections of learning courses need to be added with a theory of projective and bi-rational transformations. In terms of application simplicity and convenience it is enough to consider the central transformations when solving the applied tasks. These transformations contain a beam of sub-invariant (low-invariant straight lines on which the invariant curve induces non-involution and involution projectivities. The expediency of nonlinear transformations application is shown in the article by a specific example of geometric modeling of the interfacing surface "spar-blade".Implementation of these suggestions will contribute to a real transformation of a traditional course of descriptive geometry to the engineering geometry
Mapping of Synaptic-Neuronal Impairment on the Brain Surface through Fluctuation Analysis
International Nuclear Information System (INIS)
Musha, Toshimitsu; Kurachi, Takayoshi; Suzuki, Naohoro; Kosugi, Yukio
2005-01-01
Increase of demented population year by year is becoming a serious social problem to be solved urgently. The most effective way to block this increase is in its early detection by means of an inexpensive, non-invasive, sensitive, reliable and easy-to-operate diagnosis method. We have developed a method satisfying these requirements by using scalp potential fluctuations. We have collected 21ch EEG and SPECT data of 25 very mild Alzheimer's disease (AD) (MMSE=26±1.8), moderately severe AD (MMSE=15.3±6.4) and age-matched normal controls. As AD progresses, local synaptic-neuronal activity becomes abnormal, either more unstable or more inactive than in normal state. Such abnormality is detected in terms of normalized power variance (NPV) of a scalp potential recorded with a scalp electrode. The z-score is defined by z = ((NPV of a subject) - (mean NPV of normal subjects))/(standard deviation of NPV of normal subjects). Correlation of a measured z-score map with the mean z-score map for AD patients characterizes likelihood to AD, in terms of which AD is discriminated from normal with 75% of true positive and 25% false negative probability. By introducing two thresholds, we have 90% of true positive and 10% of false negative discrimination
Bonk, Mario
2017-01-01
This monograph is devoted to the study of the dynamics of expanding Thurston maps under iteration. A Thurston map is a branched covering map on a two-dimensional topological sphere such that each critical point of the map has a finite orbit under iteration. It is called expanding if, roughly speaking, preimages of a fine open cover of the underlying sphere under iterates of the map become finer and finer as the order of the iterate increases. Every expanding Thurston map gives rise to a fractal space, called its visual sphere. Many dynamical properties of the map are encoded in the geometry of this visual sphere. For example, an expanding Thurston map is topologically conjugate to a rational map if and only if its visual sphere is quasisymmetrically equivalent to the Riemann sphere. This relation between dynamics and fractal geometry is the main focus for the investigations in this work.
Mapping Hydrophobicity on the Protein Molecular Surface at Atom-Level Resolution
Nicolau Jr., Dan V.; Paszek, Ewa; Fulga, Florin; Nicolau, Dan V.
2014-01-01
A precise representation of the spatial distribution of hydrophobicity, hydrophilicity and charges on the molecular surface of proteins is critical for the understanding of the interaction with small molecules and larger systems. The representation of hydrophobicity is rarely done at atom-level, as this property is generally assigned to residues. A new methodology for the derivation of atomic hydrophobicity from any amino acid-based hydrophobicity scale was used to derive 8 sets of atomic hydrophobicities, one of which was used to generate the molecular surfaces for 35 proteins with convex structures, 5 of which, i.e., lysozyme, ribonuclease, hemoglobin, albumin and IgG, have been analyzed in more detail. Sets of the molecular surfaces of the model proteins have been constructed using spherical probes with increasingly large radii, from 1.4 to 20 Å, followed by the quantification of (i) the surface hydrophobicity; (ii) their respective molecular surface areas, i.e., total, hydrophilic and hydrophobic area; and (iii) their relative densities, i.e., divided by the total molecular area; or specific densities, i.e., divided by property-specific area. Compared with the amino acid-based formalism, the atom-level description reveals molecular surfaces which (i) present an approximately two times more hydrophilic areas; with (ii) less extended, but between 2 to 5 times more intense hydrophilic patches; and (iii) 3 to 20 times more extended hydrophobic areas. The hydrophobic areas are also approximately 2 times more hydrophobicity-intense. This, more pronounced “leopard skin”-like, design of the protein molecular surface has been confirmed by comparing the results for a restricted set of homologous proteins, i.e., hemoglobins diverging by only one residue (Trp37). These results suggest that the representation of hydrophobicity on the protein molecular surfaces at atom-level resolution, coupled with the probing of the molecular surface at different geometric resolutions
Mapping chemical elements on the surface of orthodontic appliance by SEM-EDX.
Mikulewicz, Marcin; Wołowiec, Paulina; Michalak, Izabela; Chojnacka, Katarzyna; Czopor, Wojciech; Berniczei-Royko, Adam; Vegh, Andras; Gedrange, Thomas
2014-05-25
During orthodontic treatment, the various elements that constitute the fixed appliance undergo different processes. As a result of a change of the surface, elution/coverage of metals on the surface can be observed in the process of corrosion/passivation. Scanning electron microscopy with an energy-dispersive X-ray analytical system (SEM-EDX) was used to analyze the composition of stainless steel elements of orthodontic fixed appliances (before and after orthodontic treatment), to obtain the composition of the surface of the elements. The analyzed elements were: brackets (Victory Series APC PLUS 022, 3M Unitek, Monrovia, CA, USA); wires (0.017×0.025, 3M Unitek, Monrovia, CA, USA); and bands (37+, 3M Unitek, Monrovia, CA, USA). The results showed a decrease of chromium and iron contribution to the surface, with increase of oxygen content in used vs. new elements of the appliance. Our results confirm the formation of oxides (passivation layer) on the surface of stainless steel as a result of the presence of the orthodontic appliance in patients' oral cavities.
Geometry of the local equivalence of states
Energy Technology Data Exchange (ETDEWEB)
Sawicki, A; Kus, M, E-mail: assawi@cft.edu.pl, E-mail: marek.kus@cft.edu.pl [Center for Theoretical Physics, Polish Academy of Sciences, Al Lotnikow 32/46, 02-668 Warszawa (Poland)
2011-12-09
We present a description of locally equivalent states in terms of symplectic geometry. Using the moment map between local orbits in the space of states and coadjoint orbits of the local unitary group, we reduce the problem of local unitary equivalence to an easy part consisting of identifying the proper coadjoint orbit and a harder problem of the geometry of fibers of the moment map. We give a detailed analysis of the properties of orbits of 'equally entangled states'. In particular, we show connections between certain symplectic properties of orbits such as their isotropy and coisotropy with effective criteria of local unitary equivalence. (paper)
Geometry essentials for dummies
Ryan, Mark
2011-01-01
Just the critical concepts you need to score high in geometry This practical, friendly guide focuses on critical concepts taught in a typical geometry course, from the properties of triangles, parallelograms, circles, and cylinders, to the skills and strategies you need to write geometry proofs. Geometry Essentials For Dummies is perfect for cramming or doing homework, or as a reference for parents helping kids study for exams. Get down to the basics - get a handle on the basics of geometry, from lines, segments, and angles, to vertices, altitudes, and diagonals Conque
DEFF Research Database (Denmark)
Jørgensen, Anders Stuhr; Andreasen, Frank
2007-01-01
Kangerlussuaq Airport is located at 67°N and 51°W in the zone of continuous permafrost in western Greenland. Its proximity to the Greenlandic ice sheet results in a dry sub-arctic climate with a mean annual temperature of −5.7 °C. The airport is built on a river terrace mostly consisting of fluvial......, in autumn 2000, three test areas were painted white in order to reduce further development of depressions in the asphalt pavement. GPR profiles crossing the white areas show a distinct difference in depth to the permafrost surface under the painted areas compared to the natural black asphalt surface. GPR...... of the permafrost surface and the formation of several depressions in the pavement of the southern parking area. The depressions can be clearly seen after rainfall. To calibrate the GPR survey, sediment samples from a borehole were analyzed with respect to water content, grain size and content of organic material...
Energy Technology Data Exchange (ETDEWEB)
Du, J.; Davis, E.J.; Roadarmel, W.H.; Wolhart, S.L.; Marsic, S.; Gusek, R.; Wright, C.A. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Pinnacle Technologies Inc., Houston, TX (United States); Brissenden, S.J.; McGillivray, P. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre; Bourne, S.; Hofstra, P. [Shell International E and P, Calgary, AB (Canada)
2005-11-01
Surface deformation measurements have been effectively used to monitor production, waterflooding, waste injection and steam flooding in oil fields, and in cyclic steam stimulation (CSS) applications. It was shown that further information can be obtained from this technique by inverting the surface deformation for the volumetric deformation at the reservoir level, so that the aerial distribution of volumetric distribution can be identified. A poroelastic model calculated deformation resulting from volumetric changes in the reservoir. A linear geophysical model was then formulated to invert the reservoir volumetric deformation from the measured surface deformation. Constraints were applied to resolve the inversion problem. Theoretical surface deformation was calculated after each inversion from the inverted volumetric deformation distribution which best fit the measured information data, or tilt, at the surface. The technique was then applied to real data from a CSS injection project at Shell Canada's Peace River development in northern Alberta, where several pads of horizontal wells have been developed. A total of 50 tiltmeters were used to monitor half of Pad A and 70 tiltmeters were used to monitor Pad B. Monitoring was used to identify and characterize any hydraulic fracturing that was contributing to injection mechanisms in the reservoir. It was noted that inverting the measured surface tilt for the volumetric change at reservoir levels improved the ability to interpret reservoir processes. It was observed that volumetric changes can be non-uniform with some pad areas deforming more than others. It was concluded that deformation-based, reservoir-level monitoring has proven helpful in ongoing efforts to optimize such variables as the length of well laterals, injection rates, lateral spacing and cycle times. 10 refs., 32 figs.
Schmitt, Rainer M.; Scott, W. Guy; Irving, Richard D.; Arnold, Joe; Bardons, Charles; Halpert, Daniel; Parker, Lawrence
2004-09-01
A new type of fingerprint sensor is presented. The sensor maps the acoustic impedance of the fingerprint pattern by estimating the electrical impedance of its sensor elements. The sensor substrate, made of 1-3 piezo-ceramic, which is fabricated inexpensively at large scales, can provide a resolution up to 50 μm over an area of 20 x 25 mm2. Using FE modeling the paper presents the numerical validation of the basic principle. It evaluates an optimized pillar aspect ratio, estimates spatial resolution and the point spread function for a 100 μm and 50 μm pitch model. In addition, first fingerprints obtained with the prototype sensor are presented.
Donaldson invariants in algebraic geometry
International Nuclear Information System (INIS)
Goettsche, L.
2000-01-01
In these lectures I want to give an introduction to the relation of Donaldson invariants with algebraic geometry: Donaldson invariants are differentiable invariants of smooth compact 4-manifolds X, defined via moduli spaces of anti-self-dual connections. If X is an algebraic surface, then these moduli spaces can for a suitable choice of the metric be identified with moduli spaces of stable vector bundles on X. This can be used to compute Donaldson invariants via methods of algebraic geometry and has led to a lot of activity on moduli spaces of vector bundles and coherent sheaves on algebraic surfaces. We will first recall the definition of the Donaldson invariants via gauge theory. Then we will show the relation between moduli spaces of anti-self-dual connections and moduli spaces of vector bundles on algebraic surfaces, and how this makes it possible to compute Donaldson invariants via algebraic geometry methods. Finally we concentrate on the case that the number b + of positive eigenvalues of the intersection form on the second homology of the 4-manifold is 1. In this case the Donaldson invariants depend on the metric (or in the algebraic geometric case on the polarization) via a system of walls and chambers. We will study the change of the invariants under wall-crossing, and use this in particular to compute the Donaldson invariants of rational algebraic surfaces. (author)
Energy Technology Data Exchange (ETDEWEB)
Koumoulos, Elias P.; Charitidis, C.A., E-mail: charitidis@chemeng.ntua.gr
2017-02-28
Highlights: • Structure and wall numbers are identified through TEM. • Static contact angle measurements revealed a super-hydrophobic behavior. • Hysteresis was observed (loading–unloading) due to the local stress distribution. • Hardness and modulus mapping for a grid of 70 μm{sup 2} is conducted. • Resistance is clearly divided in 2 regions (MWCNT and MWCNT – MWCNT) interface. - Abstract: Carbon nanotube (CNT) based architectures have increased the scientific interest owning to their exceptional performance rendering them promising candidates for advanced industrial applications in the nanotechnology field. Despite individual CNTs being considered as one of the most known strong materials, much less is known about other CNT forms, such as CNT arrays, in terms of their mechanical performance (integrity). In this work, thermal chemical vapor deposition (CVD) method is employed to produce vertically aligned multiwall (VA-MW) CNT carpets. Their structural properties were studied by means of scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Raman spectroscopy, while their hydrophobic behavior was investigated via contact angle measurements. The resistance to indentation deformation of VA-MWCNT carpets was investigated through nanoindentation technique. The synthesized VA-MWCNTs carpets consisted of well-aligned MWCNTs. Static contact angle measurements were performed with water and glycerol, revealing a rather super-hydrophobic behavior. The structural analysis, hydrophobic behavior and indentation response of VA-MWCNTs carpets synthesized via CVD method are clearly demonstrated. Additionally, cycle indentation load-depth curve was applied and hysteresis loops were observed in the indenter loading–unloading cycle due to the local stress distribution. Hardness (as resistance to applied load) and modulus mapping, at 200 nm of displacement for a grid of 70 μm{sup 2} is presented. Through trajection, the resistance is clearly divided in 2
DEFF Research Database (Denmark)
Palla, Mirkó; Bosco, Filippo; Yang, Jaeyoung
2015-01-01
Surface-enhanced Raman spectroscopy (SERS) based on nanostructured platforms is a promising technique for quantitative and highly sensitive detection of biomolecules in the field of analytical biochemistry. Here, we report a mathematical model to predict experimental SERS signal (or hotspot) inte...
Choloniewski, J.; Valentijn, E. A.
A new method for the determination of the extinction in the Galaxy is proposed. The method uses surface brightnesses of external galaxies in the B and R-bands. The observational data have been taken from the ESO-LV galaxy catalog. As a first application of our model we derive the ratio of R-band to
Mapping the Agulhas Current from space: an assessment of ASAR surface current velocities
CSIR Research Space (South Africa)
Rouault, MJ
2010-10-01
Full Text Available Over 2 years of surface current information collected in the Agulhas Current region and derived from the Doppler centroid anomalies of Envisat’s advanced synthetic aperture radar (ASAR) are examined. The sources of errors and potential use of ASAR...
Mapping surface temperature variability on a debris-covered glacier with an unmanned aerial vehicle
Kraaijenbrink, P. D. A.; Litt, M.; Shea, J. M.; Treichler, D.; Koch, I.; Immerzeel, W.
2016-12-01
Debris-covered glacier tongues cover about 12% of the glacier surface in high mountain Asia and much of the melt water is generated from those glaciers. A thin layer of supraglacial debris enhances ice melt by lowering the albedo, while thicker debris insulates the ice and reduces melt. Data on debris thickness is therefore an important input for energy balance modelling of these glaciers. Thermal infrared remote sensing can be used to estimate the debris thickness by using an inverse relation between debris surface temperature and thickness. To date this has only been performed using coarse spaceborne thermal imagery, which cannot reveal small scale variation in debris thickness and its influence on the heterogeneous melt patterns on debris-covered glaciers. We deployed an unmanned aerial vehicle mounted with a thermal infrared sensor over the debris-covered Lirung Glacier in Nepal three times in May 2016 to reveal the spatial and temporal variability of surface temperature in high detail. The UAV survey matched a Landsat 8 overpass to be able to make a comparison with spaceborne thermal imagery. The UAV-acquired data is processed using Structure from Motion photogrammetry and georeferenced using DGPS-measured ground control points. Different surface types were distinguished by using data acquired by an additional optical UAV survey in order to correct for differences in surface emissivity. In situ temperature measurements and incoming solar radiation data are used to calibrate the temperature calculations. Debris thicknesses derived are validated by thickness measurements of a ground penetrating radar. Preliminary analysis reveals a spatially highly heterogeneous pattern of surface temperature over Lirung Glacier with a range in temperature of over 40 K. At dawn the debris is relatively cold and its temperature is influenced strongly by the ice underneath. Exposed to the high solar radiation at the high altitude the debris layer heats up very rapidly as sunrise
Directory of Open Access Journals (Sweden)
Šárka Nedomová
2013-01-01
Full Text Available Precise quantification of the profile of egg can provide a powerful tool for the analysis of egg shape for various biological problems. A new approach to the geometry of a Ostrich’s egg profile is presented here using an analysing the egg’s digital photo by edge detection techniques. The obtained points on the eggshell counter are fitted by the Fourier series. The obtained equations describing an egg profile have been used to calculate radii of curvature. The radii of the curvature at the important point of the egg profile (sharp end, blunt end and maximum thickness are independent on the egg shape index. The exact values of the egg surface and the egg volume have been obtained. These quantities are also independent on the egg shape index. These quantities can be successively estimated on the basis of simplified equations which are expressed in terms of the egg length, L¸ and its width, B. The surface area of the eggshells also exhibits good correlation with the egg long circumference length. Some limitations of the most used procedures have been also shown.
Multiscale radar mapping of surface melt over mountain glaciers in High Mountain Asia
Steiner, N.; McDonald, K. C.
2017-12-01
Glacier melt dominates input for many hydrologic systems in the Himalayan Hindukush region that feed rivers that are critical for downstream ecosystems and hydropower generation in this highly populated area. Deviation in seasonal surface melt timing and duration with a changing climate has the potential to affect up to a billion people on the Indian Subcontinent. Satellite-borne microwave remote sensing has unique capabilities that allow monitoring of numerous landscape processes associated with snowmelt and freeze/thaw state, without many of the limitations in optical-infrared sensors such as solar illumination or atmospheric conditions. The onset of regional freeze/thaw and surface melting transitions determine important surface hydrologic variables like river discharge. Theses regional events are abrupt therefore difficult to observe with low-frequency observation sensors. Recently launched synthetic aperture radar (SAR) onboard the Sentinel-1 A and B satellites from the European Space Agency (ESA) provide wide-swath and high spatial resolution (50-100 m) C-Band SAR observations with observations frequencies not previously available, on the order of 8 to 16 days. The Sentinel SARs provide unique opportunity to study freeze/thaw and mountain glacier melt dynamics at process level scales, spatial and temporal. The melt process of individual glaciers, being fully resolved by imaging radar, will inform on the radiometric scattering physics associated with surface hydrology during the transition from melted to thawed state and during refreeze. Backscatter observations, along with structural information about the surface will be compared with complimentary coarse spatial resolution C-Band radar scatterometers, Advanced Scatterometer (ASCAT Met Op A+B), to understand the sub-pixel contribution of surface melting and freeze/thaw signals. This information will inform on longer-scale records of backscatter from ASCAT, 2006-2017. We present a comparison of polarimetric C
Energy Technology Data Exchange (ETDEWEB)
Pierce, Eric M [ORNL
2014-01-01
Quantitative Nanomechanical Peak Force (PF-QNM) TappingModeTM atomic force microscopy measurements are presented for the first time on polished glass surfaces. The PF-QNM technique allows for topography and mechanical property information to be measured simultaneously at each pixel. Results for the international simple glass which represents a simplified version of SON68 glass suggests an average Young s modulus of 78.8 15.1 GPa is within the experimental error of the modulus measured for SON68 glass (83.6 2 GPa) with conventional approaches. Application of the PF-QNM technique will be extended to in situ glass corrosion experiments with the goal of gaining atomic-scale insights into altered layer development by exploiting the mechanical property differences that exist between silica gel (e.g., altered layer) and pristine glass surface.
A Combined EOF/Variational Approach for Mapping Radar-Derived Sea Surface Currents
2011-01-01
gaps in the gridded SST images, which was successfully applied in Adriatic ( Alvera - Azcarate et al., 2005). Kondrashov and Chil (2006) developed...velocities. Similar to SST analysis (Beckers and Rixen, 2003: Alvera -Azcarate et al.. 2005), these modes are used to fill the gaps in HFR...and selection of the time interval for estimating the covariances becomes important. In the present study the sea surface velocity Alvera -Azcarate
Mapping Cellular Hierarchy by Single-Cell Analysis of the Cell Surface Repertoire
Guo, Guoji; Luc, Sidinh; Marco, Eugenio; Lin, Ta-Wei; Peng, Cong; Kerenyi, Marc A.; Beyaz, Semir; Kim, Woojin; Xu, Jian; Das, Partha Pratim; Neff, Tobias; Zou, Keyong; Yuan, Guo-Cheng; Orkin, Stuart H.
2013-01-01
Stem cell differentiation pathways are most often studied at the population level, whereas critical decisions are executed at the level of single cells. We have established a highly multiplexed, quantitative PCR assay to profile in an unbiased manner a panel of all commonly used cell surface markers (280 genes) from individual cells. With this method we analyzed over 1500 single cells throughout the mouse hematopoietic system, and illustrate its utility for revealing important biological insi...
Mapping Deep Low Velocity Zones in Alaskan Arctic Coastal Permafrost using Seismic Surface Waves
Dou, S.; Ajo Franklin, J. B.; Dreger, D. S.
2012-12-01
Permafrost degradation may be an important amplifier of climate change; Thawing of near-surface sediments holds the potential of increasing greenhouse gas emissions due to microbial decomposition of preserved organic carbon. Recently, the characterization of "deep" carbon pools (several meters below the surface) in circumpolar frozen ground has increased the estimated amount of soil carbon to three times higher than what was previously thought. It is therefore potentially important to include the characteristics and processes of deeper permafrost strata (on the orders of a few to tens of meters below surface) in climate models for improving future predictions of accessible carbon and climate feedbacks. This extension is particularly relevant if deeper formations are not completely frozen and may harbor on-going microbial activity despite sub-zero temperatures. Unfortunately, the characterization of deep permafrost systems is non-trivial; logistics and drilling constraints often limit direct characterization to relatively shallow units. Geophysical measurements, either surface or airborne, are often the most effective tools for evaluating these regions. Of the available geophysical techniques, the analysis of seismic surface waves (e.g. MASW) has several unique advantages, mainly the ability to provide field-scale information with good depth resolution as well as penetration (10s to 100s of m with small portable sources). Surface wave methods are also able to resolve low velocity regions, a class of features that is difficult to characterize using traditional P-wave refraction methods. As part of the Department of Energy (DOE) Next-Generation Ecosystem Experiments (NGEE-Arctic) project, we conducted a three-day seismic field survey (May 12 - 14, 2012) at the Barrow Environmental Observatory, which is located within the Alaskan Arctic Coastal Plain. Even though permafrost at the study site is continuous, ice-rich and thick (>= 350m), our Multichannel Analysis of
Zam, Azhar; Dsouza, Roshan; Subhash, Hrebesh M; O'Connell, Marie-Louise; Enfield, Joey; Larin, Kirill; Leahy, Martin J
2013-09-01
We propose the use of correlation mapping optical coherence tomography (cmOCT) to deliver additional biometrics associated with the finger that could complement existing fingerprint technology for law enforcement applications. The current study extends the existing fingerprint paradigm by measuring additional biometrics associated with sub-surface finger tissue such as sub-surface fingerprints, sweat glands, and the pattern of the capillary bed to yield a user-friendly cost effective and anti-spoof multi-mode biometric solution associated with the finger. To our knowledge no other method has been able to capture sub-surface fingerprint, papillary pattern and horizontal vessel pattern in a single scan or to show the correspondence between these patterns in live adult human fingertip. Unlike many current technologies this approach incorporates 'liveness' testing by default. The ultimate output is a biometric module which is difficult to defeat and complements fingerprint scanners that currently are used in border control and law enforcement applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
McClintock, Carlee S; Hettich, Robert L
2013-01-02
Oxidative protein surface mapping has become a powerful approach for measuring the solvent accessibility of folded protein structures. A variety of techniques exist for generating the key reagent (i.e., hydroxyl radicals) for these measurements; however, these approaches range significantly in their complexity and expense of operation. This research expands upon earlier work to enhance the controllability of boron-doped diamond (BDD) electrochemistry as an easily accessible tool for producing hydroxyl radicals in order to oxidize a range of intact proteins. Efforts to modulate the oxidation level while minimizing the adsorption of protein to the electrode involved the use of relatively high flow rates to reduce protein residence time inside the electrochemical flow chamber. Additionally, a different cell activation approach using variable voltage to supply a controlled current allowed us to precisely tune the extent of oxidation in a protein-dependent manner. In order to gain perspective on the level of protein adsorption onto the electrode surface, studies were conducted to monitor protein concentration during electrolysis and gauge changes in the electrode surface between cell activation events. This report demonstrates the successful use of BDD electrochemistry for greater precision in generating a target number of oxidation events upon intact proteins.
Topics in modern differential geometry
Verstraelen, Leopold
2017-01-01
A variety of introductory articles is provided on a wide range of topics, including variational problems on curves and surfaces with anisotropic curvature. Experts in the fields of Riemannian, Lorentzian and contact geometry present state-of-the-art reviews of their topics. The contributions are written on a graduate level and contain extended bibliographies. The ten chapters are the result of various doctoral courses which were held in 2009 and 2010 at universities in Leuven, Serbia, Romania and Spain.
International Nuclear Information System (INIS)
Buescher, R.
2005-01-01
Casimir interactions are interactions induced by quantum vacuum fluctuations and thermal fluctuations of the electromagnetic field. Using a path integral quantization for the gauge field, an effective Gaussian action will be derived which is the starting point to compute Casimir forces between macroscopic objects analytically and numerically. No assumptions about the independence of the material and shape dependent contributions to the interaction are made. We study the limit of flat surfaces in further detail and obtain a concise derivation of Lifshitz' theory of molecular forces. For the case of ideally conducting boundaries, the Gaussian action will be calculated explicitly. Both limiting cases are also discussed within the framework of a scalar field quantization approach, which is applicable for translationally invariant geometries. We develop a non-perturbative approach to calculate the Casimir interaction from the Gaussian action for periodically deformed and ideally conducting objects numerically. The obtained results reveal two different scaling regimes for the Casimir force as a function of the distance between the objects, their deformation wavelength and -amplitude. The results confirm that the interaction is non-additive, especially in the presence of strong geometric deformations. Furthermore, the numerical approach is extended to calculate lateral Casimir forces. The results are consistent with the results of the proximity-force approximation for large deformation wavelengths. A qualitatively different behaviour between the normal and lateral force is revealed. We also establish a relation between the boundary induced change of the of the density of states for the scalar Helmholtz equation and the Casimir interaction using the path integral method. For statically deformed boundaries, this relation can be expressed as a novel trace formula, which is formally similar to the so-called Krein-Friedel-Lloyd formula. While the latter formula describes the
Planetary Image Geometry Library
Deen, Robert C.; Pariser, Oleg
2010-01-01
The Planetary Image Geometry (PIG) library is a multi-mission library used for projecting images (EDRs, or Experiment Data Records) and managing their geometry for in-situ missions. A collection of models describes cameras and their articulation, allowing application programs such as mosaickers, terrain generators, and pointing correction tools to be written in a multi-mission manner, without any knowledge of parameters specific to the supported missions. Camera model objects allow transformation of image coordinates to and from view vectors in XYZ space. Pointing models, specific to each mission, describe how to orient the camera models based on telemetry or other information. Surface models describe the surface in general terms. Coordinate system objects manage the various coordinate systems involved in most missions. File objects manage access to metadata (labels, including telemetry information) in the input EDRs and RDRs (Reduced Data Records). Label models manage metadata information in output files. Site objects keep track of different locations where the spacecraft might be at a given time. Radiometry models allow correction of radiometry for an image. Mission objects contain basic mission parameters. Pointing adjustment ("nav") files allow pointing to be corrected. The object-oriented structure (C++) makes it easy to subclass just the pieces of the library that are truly mission-specific. Typically, this involves just the pointing model and coordinate systems, and parts of the file model. Once the library was developed (initially for Mars Polar Lander, MPL), adding new missions ranged from two days to a few months, resulting in significant cost savings as compared to rewriting all the application programs for each mission. Currently supported missions include Mars Pathfinder (MPF), MPL, Mars Exploration Rover (MER), Phoenix, and Mars Science Lab (MSL). Applications based on this library create the majority of operational image RDRs for those missions. A
Bárány, Imre; Vilcu, Costin
2016-01-01
This volume presents easy-to-understand yet surprising properties obtained using topological, geometric and graph theoretic tools in the areas covered by the Geometry Conference that took place in Mulhouse, France from September 7–11, 2014 in honour of Tudor Zamfirescu on the occasion of his 70th anniversary. The contributions address subjects in convexity and discrete geometry, in distance geometry or with geometrical flavor in combinatorics, graph theory or non-linear analysis. Written by top experts, these papers highlight the close connections between these fields, as well as ties to other domains of geometry and their reciprocal influence. They offer an overview on recent developments in geometry and its border with discrete mathematics, and provide answers to several open questions. The volume addresses a large audience in mathematics, including researchers and graduate students interested in geometry and geometrical problems.
Energy Technology Data Exchange (ETDEWEB)
Sexton, Joshua L [JL Sexton and Son; Fryar, Alan E [Dept of Earth and Geoligical Sciences, Univ of KY,; Greb, s F [Univ of KY, KY Geological Survey
2006-04-01
POSTER: The Jackson Purchase region of western Kentucky consists of Coastal Plain sediments near the northern margin of the Mississippi Embayment. Within this region is the Paducah Gaseous Diffusion Plant (PGDP), a uranium enrichment facility operated by the US Department of Energy. At PGDP, a Superfund site, soil and groundwater studies have provided subsurface lithologic data from hundreds of monitoring wells and borings. Despite preliminary efforts by various contractors, these data have not been utilized to develop detailed stratigraphic correlations of sedimentary units across the study area. In addition, sedimentary exposures along streams in the vicinityof PGDP have not been systematically described beyond the relatively simple geologic quadrangle maps published by the US Geological Survey in 1966-67. This study integrates lithologic logs, other previous site investigation data, and outcrop mapping to provide a compilation of near-surface lithologic and stratigraphic data for the PGDP area. A database of borehole data compiled during this study has been provided to PGDP for future research and archival.
DEFF Research Database (Denmark)
Palla, Mirko; Kumar, Shiv; Li, Zengmin
2016-01-01
We describe here a novel surface-enhanced Raman spectroscopy (SERS) based technique for monitoring the conjugation of small molecules by the well-known click reaction between an alkyne and azido moiety on the partner molecules. The monitoring principle is based on the loss of the characteristic...... alkyne/azide Raman signal with triazole formation in the reaction as a function of time. Since these universal Raman reporter groups are specific for click reactions, this method may facilitate a broad range of applications for monitoring the conjugation efficiency of molecules in diverse areas...
An imaging system for quantitive surface temperature mapping using two-color thermographic phosphors
Buck, Gregory M.
1988-01-01
A technique for obtaining detailed quantitative temperature distributions on test models in hypersonic wind tunnels is presented. This technique is based on the ratio of blue to green (450, 520 nm) emission from an UV (365 nm) excited phosphor coating. Separately filtered images are recorded from a three-tube color camera, utilizing off-the-shelf front-end video optics to discriminate wavelengths. Two demonstration studies in a 31-inch Mach 10 tunnel are discussed. One study presents the windward surface temperature-time history for a transatmospheric vehicle, and the other illustrates nosetip heating on a spherically blunted slender cone.
Boutron, Olivier; Margoum, Christelle; Chovelon, Jean-Marc; Guillemain, CéLine; Gouy, VéRonique
2011-08-01
Pesticides, which have been extensively used in agriculture, have become a major environmental issue, especially regarding surface and groundwater contamination. Of particular importance are vegetated farm drainage ditches, which can play an important role in the mitigation of pesticide contamination by adsorption onto ditch bed substrates. This role is, however, poorly understood, especially regarding the influence of hydrodynamic parameters, which make it difficult to promote best management practice of these systems. We have assessed the influence of three of these parameters (speed of the surface water flow, submergence, and geometrical characteristics of the bed forms) on the transfer and adsorption of selected pesticides (isoproturon, diuron, tebuconazole, and azoxystrobin) into the bed substrate by performing experiments with a tilted experimental flume, using hemp fibers as a standard of natural organic substrates that are found at the bottom of agricultural ditches. Results show the transfer of pesticides from surface water flow into bed substrate is favored, both regarding the amounts transferred into the bed substrate and the kinetics of the transfer, when the surface water speed and the submergence increase and when the bed forms are made of rectangular shapes. Extrapolation of flume data over a distance of several hundred meters suggests that an interesting possibility for improving the mitigation of pesticides in ditches would be to increase the submergence and to favor bed forms that tend to enhance perturbations and subsequent infiltration of the surface water flow.
POLE PHOTOGRAMMETRY WITH AN ACTION CAMERA FOR FAST AND ACCURATE SURFACE MAPPING
Directory of Open Access Journals (Sweden)
J. A. Gonçalves
2016-06-01
Full Text Available High resolution and high accuracy terrain mapping can provide height change detection for studies of erosion, subsidence or land slip. A UAV flying at a low altitude above the ground, with a compact camera, acquires images with resolution appropriate for these change detections. However, there may be situations where different approaches may be needed, either because higher resolution is required or the operation of a drone is not possible. Pole photogrammetry, where a camera is mounted on a pole, pointing to the ground, is an alternative. This paper describes a very simple system of this kind, created for topographic change detection, based on an action camera. These cameras have high quality and very flexible image capture. Although radial distortion is normally high, it can be treated in an auto-calibration process. The system is composed by a light aluminium pole, 4 meters long, with a 12 megapixel GoPro camera. Average ground sampling distance at the image centre is 2.3 mm. The user moves along a path, taking successive photos, with a time lapse of 0.5 or 1 second, and adjusting the speed in order to have an appropriate overlap, with enough redundancy for 3D coordinate extraction. Marked ground control points are surveyed with GNSS for precise georeferencing of the DSM and orthoimage that are created by structure from motion processing software. An average vertical accuracy of 1 cm could be achieved, which is enough for many applications, for example for soil erosion. The GNSS survey in RTK mode with permanent stations is now very fast (5 seconds per point, which results, together with the image collection, in a very fast field work. If an improved accuracy is needed, since image resolution is 1/4 cm, it can be achieved using a total station for the control point survey, although the field work time increases.
Pole Photogrammetry with AN Action Camera for Fast and Accurate Surface Mapping
Gonçalves, J. A.; Moutinho, O. F.; Rodrigues, A. C.
2016-06-01
High resolution and high accuracy terrain mapping can provide height change detection for studies of erosion, subsidence or land slip. A UAV flying at a low altitude above the ground, with a compact camera, acquires images with resolution appropriate for these change detections. However, there may be situations where different approaches may be needed, either because higher resolution is required or the operation of a drone is not possible. Pole photogrammetry, where a camera is mounted on a pole, pointing to the ground, is an alternative. This paper describes a very simple system of this kind, created for topographic change detection, based on an action camera. These cameras have high quality and very flexible image capture. Although radial distortion is normally high, it can be treated in an auto-calibration process. The system is composed by a light aluminium pole, 4 meters long, with a 12 megapixel GoPro camera. Average ground sampling distance at the image centre is 2.3 mm. The user moves along a path, taking successive photos, with a time lapse of 0.5 or 1 second, and adjusting the speed in order to have an appropriate overlap, with enough redundancy for 3D coordinate extraction. Marked ground control points are surveyed with GNSS for precise georeferencing of the DSM and orthoimage that are created by structure from motion processing software. An average vertical accuracy of 1 cm could be achieved, which is enough for many applications, for example for soil erosion. The GNSS survey in RTK mode with permanent stations is now very fast (5 seconds per point), which results, together with the image collection, in a very fast field work. If an improved accuracy is needed, since image resolution is 1/4 cm, it can be achieved using a total station for the control point survey, although the field work time increases.
Zhang, L.; Lu, Zhong; Ding, X.; Jung, H.-S.; Feng, G.; Lee, C.-W.
2012-01-01
Multi-temporal interferometric synthetic aperture radar (InSAR) is an effective tool to detect long-term seismotectonic motions by reducing the atmospheric artifacts, thereby providing more precise deformation signal. The commonly used approaches such as persistent scatterer InSAR (PSInSAR) and small baseline subset (SBAS) algorithms need to resolve the phase ambiguities in interferogram stacks either by searching a predefined solution space or by sparse phase unwrapping methods; however the efficiency and the success of phase unwrapping cannot be guaranteed. We present here an alternative approach – temporarily coherent point (TCP) InSAR (TCPInSAR) – to estimate the long term deformation rate without the need of phase unwrapping. The proposed approach has a series of innovations including TCP identification, TCP network and TCP least squares estimator. We apply the proposed method to the Los Angeles Basin in southern California where structurally active faults are believed capable of generating damaging earthquakes. The analysis is based on 55 interferograms from 32 ERS-1/2 images acquired during Oct. 1995 and Dec. 2000. To evaluate the performance of TCPInSAR on a small set of observations, a test with half of interferometric pairs is also performed. The retrieved TCPInSAR measurements have been validated by a comparison with GPS observations from Southern California Integrated GPS Network. Our result presents a similar deformation pattern as shown in past InSAR studies but with a smaller average standard deviation (4.6 mm) compared with GPS observations, indicating that TCPInSAR is a promising alternative for efficiently mapping ground deformation even from a relatively smaller set of interferograms.
Gowthaman, Ragul; Miller, Sven A; Rogers, Steven; Khowsathit, Jittasak; Lan, Lan; Bai, Nan; Johnson, David K; Liu, Chunjing; Xu, Liang; Anbanandam, Asokan; Aubé, Jeffrey; Roy, Anuradha; Karanicolas, John
2016-05-12
Protein-protein interactions represent an exciting and challenging target class for therapeutic intervention using small molecules. Protein interaction sites are often devoid of the deep surface pockets presented by "traditional" drug targets, and crystal structures reveal that inhibitors typically engage these sites using very shallow binding modes. As a consequence, modern virtual screening tools developed to identify inhibitors of traditional drug targets do not perform as well when they are instead deployed at protein interaction sites. To address the need for novel inhibitors of important protein interactions, here we introduce an alternate docking strategy specifically designed for this regime. Our method, termed DARC (Docking Approach using Ray-Casting), matches the topography of a surface pocket "observed" from within the protein to the topography "observed" when viewing a potential ligand from the same vantage point. We applied DARC to carry out a virtual screen against the protein interaction site of human antiapoptotic protein Mcl-1 and found that four of the top-scoring 21 compounds showed clear inhibition in a biochemical assay. The Ki values for these compounds ranged from 1.2 to 21 μM, and each had ligand efficiency comparable to promising small-molecule inhibitors of other protein-protein interactions. These hit compounds do not resemble the natural (protein) binding partner of Mcl-1, nor do they resemble any known inhibitors of Mcl-1. Our results thus demonstrate the utility of DARC for identifying novel inhibitors of protein-protein interactions.
Phillips, N.; Crosson, E.; Down, A.; Hutyra, L.; Jackson, R. B.; McKain, K.; Rella, C.; Raciti, S. M.; Wofsy, S. C.
2012-12-01
Lost and unaccounted natural gas can amount to over 6% of Massachusetts' total annual greenhouse gas inventory (expressed as equivalent CO2 tonnage). An unknown portion of this loss is due to natural gas leaks in pipeline distribution systems. The objective of the Boston Methane Project is to estimate the overall leak rate from natural gas systems in metropolitan Boston, and to compare this flux with fluxes from the other primary methane emissions sources. Companion talks at this meeting describe the atmospheric measurement and modeling framework, and chemical and isotopic tracers that can partition total atmospheric methane flux into natural gas and non-natural gas components. This talk focuses on estimation of surface emissions that inform the atmospheric modeling and partitioning. These surface emissions include over 3,300 pipeline natural gas leaks in Boston. For the state of Massachusetts as a whole, the amount of natural gas reported as lost and unaccounted for by utility companies was greater than estimated landfill emissions by an order of magnitude. Moreover, these landfill emissions were overwhelmingly located outside of metro Boston, while gas leaks are concentrated in exactly the opposite pattern, increasing from suburban Boston toward the urban core. Work is in progress to estimate spatial distribution of methane emissions from wetlands and sewer systems. We conclude with a description of how these spatial data sets will be combined and represented for application in atmospheric modeling.
Mapping the surface of MNKr2 and CopZ - identification of residues critical for metallotransfer
International Nuclear Information System (INIS)
Jones, C.E.; Cobine, P.A.; Dameron, C.T.
2001-01-01
Full text: Cells utilise a network of proteins that include CPx-type ATPases and metallochaperones to balance intracellular copper concentration. The Menkes ATPase has six N-terminal domains which bind Cu(I) and are critical for ATPase function. The NMR solution structure of the second domain (MNKr2) shows that the structure adopts an 'open-faced β-sandwich' fold, in which two α-helices lie over a single four stranded β-sheet. The global fold is identical to the bacterial copper chaperone CopZ MNKr2 is unable to substitute for CopZ in copper transfer to the cop operon represser, CopY. To investigate how structure affects function we have analysed the surface features of MNKr2 and CopZ Despite having the same global fold, MNKr2 and CopZ have contrasting electrostatic surfaces, which may partially explain the inability of MNKr2 to transfer copper to CopY
Neutron-induced gamma-ray spectroscopy: simulations for chemical mapping of planetary surfaces
International Nuclear Information System (INIS)
Brueckner, J.; Waenke, H.; Reedy, R.C.
1986-01-01
Cosmic rays interact with the surface of a planetary body and produce a cascade of secondary particles, such as neutrons. Neutron-induced scattering and capture reactions play an important role in the production of discrete gamma-ray lines that can be measured by a gamma-ray spectrometer on board of an orbiting spacecraft. These data can be used to determine the concentration of many elements in the surface of a planetary body, which provides clues to its bulk composition and in turn to its origin and evolution. To investigate the gamma rays made by neutron interactions, thin targets were irradiated with neutrons having energies from 14 MeV to 0.025 eV. By means of foil activation technique the ratio of epithermal to thermal neutrons was determined to be similar to that in the Moon. Gamma rays emitted by the targets and the surrounding material were detected by a high-resolution germanium detector in the energy range of 0.1 to 8 MeV. Most of the gamma-ray lines that are expected to be used for planetary gamma-ray spectroscopy were found in the recorded spectra and the principal lines in these spectra are presented. 58 refs., 7 figs., 9 tabs
Algorithms in Algebraic Geometry
Dickenstein, Alicia; Sommese, Andrew J
2008-01-01
In the last decade, there has been a burgeoning of activity in the design and implementation of algorithms for algebraic geometric computation. Some of these algorithms were originally designed for abstract algebraic geometry, but now are of interest for use in applications and some of these algorithms were originally designed for applications, but now are of interest for use in abstract algebraic geometry. The workshop on Algorithms in Algebraic Geometry that was held in the framework of the IMA Annual Program Year in Applications of Algebraic Geometry by the Institute for Mathematics and Its
O'Leary, Michael
2010-01-01
Guides readers through the development of geometry and basic proof writing using a historical approach to the topic. In an effort to fully appreciate the logic and structure of geometric proofs, Revolutions of Geometry places proofs into the context of geometry's history, helping readers to understand that proof writing is crucial to the job of a mathematician. Written for students and educators of mathematics alike, the book guides readers through the rich history and influential works, from ancient times to the present, behind the development of geometry. As a result, readers are successfull
Fundamental concepts of geometry
Meserve, Bruce E
1983-01-01
Demonstrates relationships between different types of geometry. Provides excellent overview of the foundations and historical evolution of geometrical concepts. Exercises (no solutions). Includes 98 illustrations.