rigid square inclusion: Topics by WorldWideScience.org

Sample records for rigid square inclusion

Effect of rigid inclusions on sintering

International Nuclear Information System (INIS)

Rahaman, M.N.; De Jonghe, L.C.

1988-01-01

The predictions of recent theoretical studies on the effect of inert, rigid inclusions on the sintering of ceramic powder matrices are examined and compared with experimental data. The densification of glass matrix composites with inclusion volume fractions of ≤0.15 can be adequately explained by Scherer's theory for viscous sintering with rigid inclusions. Inclusions cause a vast reduction in the densification rates of polycrystalline matrix composites even at low inclusion volume fractions. Models put forward to explain the sintering of polycrystalline matrix composites are discussed
Soft soils reinforced by rigid vertical inclusions

Directory of Open Access Journals (Sweden)

Iulia-Victoria NEAGOE

2013-12-01

Full Text Available Reinforcement of soft soils by rigid vertical inclusions is an increasingly used technique over the last few years. The system consists of rigid or semi-rigid vertical inclusions and a granular platform for the loads transfer from the structure to the inclusions. This technique aims to reduce the differential settlements both at ground level as below the structure. Reinforcement by rigid inclusions is mainly used for foundation works for large commercial and industrial platforms, storage tanks, wastewater treatment plants, wind farms, bridges, roads, railway embankments. The subject is one of interest as it proves the recently concerns at international level in research and design; however, most studies deal more with the static behavior and less with the dynamic one.
Rigid inclusions-Comparison between analytical and numerical methods

International Nuclear Information System (INIS)

Gomez Perez, R.; Melentijevic, S.

2014-01-01

This paper compares different analytical methods for analysis of rigid inclusions with finite element modeling. First of all, the load transfer in the distribution layer is analyzed for its different thicknesses and different inclusion grids to define the range between results obtained by analytical and numerical methods. The interaction between the soft soil and the inclusion in the estimation of settlements is studied as well. Considering different stiffness of the soft soil, settlements obtained analytical and numerically are compared. The influence of the soft soil modulus of elasticity on the neutral point depth was also performed by finite elements. This depth has a great importance for the definition of the total length of rigid inclusion. (Author)
Superplastic flow of two-phase ceramics containing rigid inclusions-zirconia/mullite composites

International Nuclear Information System (INIS)

Yoon, C.K.; Chen, I.W.

1990-01-01

A continuum theory for non-newtonian flow of a two-phase composite containing rigid inclusions is presented. It predicts flow suppression by a factor of (1 - V) q , where V is the volume fraction of the rigid inclusion and q depends on the stress exponent and the inclusion shape. Stress concentrations in the rigid inclusion have also been evaluated. As the stress exponent increases, flow suppression is more pronounced even though stress concentration is less severe. To test this theory, superplastic flow of zirconia/mullite composites, in which zirconia is a soft, non-Newtonian super-plastic matrix and mullite is a rigid phase of various size, shape, and amount, is studied. The continuum theory is found to describe the two-phase superplastic flow reasonably well
A rigid-body least-squares program with angular and translation scan facilities

CERN Document Server

Kutschabsky, L

1981-01-01

The described computer program, written in CERN Fortran, is designed to enlarge the convergence radius of the rigid-body least-squares method by allowing a stepwise change of the angular and/or translational parameters within a chosen range. (6 refs).
A coated rigid elliptical inclusion loaded by a couple in the presence of uniform interfacial and hoop stresses

Science.gov (United States)

Wang, Xu; Schiavone, Peter

2018-06-01

We consider a confocally coated rigid elliptical inclusion, loaded by a couple and introduced into a remote uniform stress field. We show that uniform interfacial and hoop stresses along the inclusion-coating interface can be achieved when the two remote normal stresses and the remote shear stress each satisfy certain conditions. Our analysis indicates that: (i) the uniform interfacial tangential stress depends only on the area of the inclusion and the moment of the couple; (ii) the rigid-body rotation of the rigid inclusion depends only on the area of the inclusion, the coating thickness, the shear moduli of the composite and the moment of the couple; (iii) for given remote normal stresses and material parameters, the coating thickness and the aspect ratio of the inclusion are required to satisfy a particular relationship; (iv) for prescribed remote shear stress, moment and given material parameters, the coating thickness, the size and aspect ratio of the inclusion are also related. Finally, a harmonic rigid inclusion emerges as a special case if the coating and the matrix have identical elastic properties.
Rigid inclusions-Comparison between analytical and numerical methods; Inclusiones rigidas-Analisis comparativo de los metodos analiticos y numericos

Energy Technology Data Exchange (ETDEWEB)

Gomez Perez, R.; Melentijevic, S.

2014-07-01

This paper compares different analytical methods for analysis of rigid inclusions with finite element modeling. First of all, the load transfer in the distribution layer is analyzed for its different thicknesses and different inclusion grids to define the range between results obtained by analytical and numerical methods. The interaction between the soft soil and the inclusion in the estimation of settlements is studied as well. Considering different stiffness of the soft soil, settlements obtained analytical and numerically are compared. The influence of the soft soil modulus of elasticity on the neutral point depth was also performed by finite elements. This depth has a great importance for the definition of the total length of rigid inclusion. (Author)
Thermal stresses in an orthotropic rectangular plate with a rigid ribbonlike inclusion

International Nuclear Information System (INIS)

Sumi, N.

1981-01-01

On the basis of the complex variable method for determining the stationary two-dimensional thermal stresses, the thermal stresses in an orthotropic rectangular plate with a rigid ribbonlike inclusion under a steady state temperature field is considered. The solution is found by the analytic continuation argument and the modified mapping-collocation technique. Numerical results indicate a dependence of the orthotropic stress intensity factors on the thermal, elastic and geometrical constants over a certain parameter range. (orig.)
Forces and torques on rigid inclusions in an elastic environment: Resulting matrix-mediated interactions, displacements, and rotations

Science.gov (United States)

Puljiz, Mate; Menzel, Andreas M.

2017-05-01

Embedding rigid inclusions into elastic matrix materials is a procedure of high practical relevance, for instance, for the fabrication of elastic composite materials. We theoretically analyze the following situation. Rigid spherical inclusions are enclosed by a homogeneous elastic medium under stick boundary conditions. Forces and torques are directly imposed from outside onto the inclusions or are externally induced between them. The inclusions respond to these forces and torques by translations and rotations against the surrounding elastic matrix. This leads to elastic matrix deformations, and in turn results in mutual long-ranged matrix-mediated interactions between the inclusions. Adapting a well-known approach from low-Reynolds-number hydrodynamics, we explicitly calculate the displacements and rotations of the inclusions from the externally imposed or induced forces and torques. Analytical expressions are presented as a function of the inclusion configuration in terms of displaceability and rotateability matrices. The role of the elastic environment is implicitly included in these relations. That is, the resulting expressions allow a calculation of the induced displacements and rotations directly from the inclusion configuration, without having to explicitly determine the deformations of the elastic environment. In contrast to the hydrodynamic case, compressibility of the surrounding medium is readily taken into account. We present the complete derivation based on the underlying equations of linear elasticity theory. In the future, the method will, for example, be helpful to characterize the behavior of externally tunable elastic composite materials, to accelerate numerical approaches, as well as to improve the quantitative interpretation of microrheological results.
The cumulative measure of a force: A unified kinetic theory for rigid-sphere and inverse-square force law interactions

Directory of Open Access Journals (Sweden)

Yongbin Chang

2011-09-01

Full Text Available By introducing a cutoff on the cumulative measure of a force, a unified kinetic theory is developed for both rigid-sphere and inverse-square force laws. The difference between the two kinds of interactions is characterized by a parameter, γ, which is 1 for rigid-sphere interactions and -3 for inverse-square force law interactions. The quantities governed by γ include the specific reaction rates, kernels, collision frequencies, arbitrarily high orders of transition moments, arbitrarily high orders of Fokker-Planck expansion (also called Kramers-Moyal expansion coefficients, and arbitrarily high orders of energy exchange rates. The cutoff constants are shown to be incomplete gamma functions of different orders. The widely used cutoff constant in plasma physics (usually known as Coulomb logarithm is found to be exactly the zeroth order of the incomplete gamma function. The well known Arrhenius reaction rate formula comes from the first order of the incomplete gamma functions, while the negative first order can be used for fitting the fusion reaction rate between deuterium and tritium.
Controlling elastic waves with small phononic crystals containing rigid inclusions

KAUST Repository

Peng, Pai

2014-05-01

We show that a two-dimensional elastic phononic crystal comprising rigid cylinders in a solid matrix possesses a large complete band gap below a cut-off frequency. A mechanical model reveals that the band gap is induced by negative effective mass density, which is affirmed by an effective medium theory based on field averaging. We demonstrate, by two examples, that such elastic phononic crystals can be utilized to design small devices to control low-frequency elastic waves. One example is a waveguide made of a two-layer anisotropic elastic phononic crystal, which can guide and bend elastic waves with wavelengths much larger than the size of the waveguide. The other example is the enhanced elastic transmission of a single-layer elastic phononic crystal loaded with solid inclusions. The effective mass density and reciprocal of the modulus of the single-layer elastic phononic crystal are simultaneously near zero. © CopyrightEPLA, 2014.
Fluidelastic instability of a flexible tube in a rigid normal square array subjected to uniform two-phase cross-flows

International Nuclear Information System (INIS)

Axisa, F.; Villard, B.; Antunes, J.

1989-01-01

During the last decade several researchers, investigated fluidelastic instability in tube arrays by restricting the problem to a single degree of freedom system. This is a very attractive idea because of obvious theoretical and experimental simplifications. Nevertheless, it has still to be clarified how far such results can be applied to fully flexible arrays. This paper is presenting a few experimental data obtained on a rigid normal square array subjected to uniform air-water cross flows, at various homogeneous void fractions α H from O to 1. Fluidelastic instability was clearly observed in air and in water. However instability was progressively vanishing in two-phase flow, when α H was increased. Such a result is contrasting with those obtained on fully flexible arrays
Identifying Floppy and Rigid Regions in Proteins

Science.gov (United States)

Jacobs, D. J.; Thorpe, M. F.; Kuhn, L. A.

1998-03-01

In proteins it is possible to separate hard covalent forces involving bond lengths and bond angles from other weak forces. We model the microstructure of the protein as a generic bar-joint truss framework, where the hard covalent forces and strong hydrogen bonds are regarded as rigid bar constraints. We study the mechanical stability of proteins using FIRST (Floppy Inclusions and Rigid Substructure Topography) based on a recently developed combinatorial constraint counting algorithm (the 3D Pebble Game), which is a generalization of the 2D pebble game (D. J. Jacobs and M. F. Thorpe, ``Generic Rigidity: The Pebble Game'', Phys. Rev. Lett.) 75, 4051-4054 (1995) for the special class of bond-bending networks (D. J. Jacobs, "Generic Rigidity in Three Dimensional Bond-bending Networks", Preprint Aug (1997)). This approach is useful in identifying rigid motifs and flexible linkages in proteins, and thereby determines the essential degrees of freedom. We will show some preliminary results from the FIRST analysis on the myohemerythrin and lyozyme proteins.
Standard and inverse bond percolation of straight rigid rods on square lattices

Science.gov (United States)

Ramirez, L. S.; Centres, P. M.; Ramirez-Pastor, A. J.

2018-04-01

Numerical simulations and finite-size scaling analysis have been carried out to study standard and inverse bond percolation of straight rigid rods on square lattices. In the case of standard percolation, the lattice is initially empty. Then, linear bond k -mers (sets of k linear nearest-neighbor bonds) are randomly and sequentially deposited on the lattice. Jamming coverage pj ,k and percolation threshold pc ,k are determined for a wide range of k (1 ≤k ≤120 ). pj ,k and pc ,k exhibit a decreasing behavior with increasing k , pj ,k →∞=0.7476 (1 ) and pc ,k →∞=0.0033 (9 ) being the limit values for large k -mer sizes. pj ,k is always greater than pc ,k, and consequently, the percolation phase transition occurs for all values of k . In the case of inverse percolation, the process starts with an initial configuration where all lattice bonds are occupied and, given that periodic boundary conditions are used, the opposite sides of the lattice are connected by nearest-neighbor occupied bonds. Then, the system is diluted by randomly removing linear bond k -mers from the lattice. The central idea here is based on finding the maximum concentration of occupied bonds (minimum concentration of empty bonds) for which connectivity disappears. This particular value of concentration is called the inverse percolation threshold pc,k i, and determines a geometrical phase transition in the system. On the other hand, the inverse jamming coverage pj,k i is the coverage of the limit state, in which no more objects can be removed from the lattice due to the absence of linear clusters of nearest-neighbor bonds of appropriate size. It is easy to understand that pj,k i=1 -pj ,k . The obtained results for pc,k i show that the inverse percolation threshold is a decreasing function of k in the range 1 ≤k ≤18 . For k >18 , all jammed configurations are percolating states, and consequently, there is no nonpercolating phase. In other words, the lattice remains connected even when
Analysis of the Main Access Municipal Project Free and Free Internet in Public Squares: Digital Inclusion in the Present Corporate Information Globalized

Directory of Open Access Journals (Sweden)

Anderson Nogueira Oliveira

2015-12-01

Full Text Available The present study has as its theme the role of municipalities in the current global information society. So it has the general objective analysis on the free access to the internet in public places as a means of digital inclusion, with such spaces known as digital o hotspots squares. In this case we will present concepts, definitions and brief historical development of the objects of study of this research, namely, globalization, the information society and digital inclusion. We emphasize that this research will analyze recent data on internet access in Brazil, and will check the key municipal projects freely and free internet access in public squares. For this research we use the hypothetical-deductive method by the methodology of analysis of books, scientific papers and official data by renamed institutions to present a scientifically valid conclusion.
BIOMECHANICS. Why the seahorse tail is square.

Science.gov (United States)

Porter, Michael M; Adriaens, Dominique; Hatton, Ross L; Meyers, Marc A; McKittrick, Joanna

2015-07-03

Whereas the predominant shapes of most animal tails are cylindrical, seahorse tails are square prisms. Seahorses use their tails as flexible grasping appendages, in spite of a rigid bony armor that fully encases their bodies. We explore the mechanics of two three-dimensional-printed models that mimic either the natural (square prism) or hypothetical (cylindrical) architecture of a seahorse tail to uncover whether or not the square geometry provides any functional advantages. Our results show that the square prism is more resilient when crushed and provides a mechanism for preserving articulatory organization upon extensive bending and twisting, as compared with its cylindrical counterpart. Thus, the square architecture is better than the circular one in the context of two integrated functions: grasping ability and crushing resistance. Copyright © 2015, American Association for the Advancement of Science.
Child- and elder-friendly urban public places in Fatahillah Square Historical District

Science.gov (United States)

Srinaga, F.; LKatoppo, M.; Hidayat, J.

2018-03-01

Fatahillah square as an important historical urban square in Jakarta has problems in eye level area integrative processing. Visitors cannot enjoy their time while in the square regarding their visuals, feelings, space, and bodies comfort. These also lead to other problems in which the square is lack of friendly and convenient places for children, the elderly and also the disabled, especially people with limited moving space. The research will attempt in proposing design inception for the Fatahillah Square that is using inclusive user-centered design approach, while in the same time incorporate theoretical studies of children and elderly-design considerations. The first stage of this research was building inclusive design parameter; begin with a context-led research which assesses the quality of Fatahillah square through three basic components of urban space: hardware, software and orgware. The second stage of this research is to propose inclusive design inception for the Fatahillah square.
On removing interpolation and resampling artifacts in rigid image registration.

Science.gov (United States)

Aganj, Iman; Yeo, Boon Thye Thomas; Sabuncu, Mert R; Fischl, Bruce

2013-02-01

We show that image registration using conventional interpolation and summation approximations of continuous integrals can generally fail because of resampling artifacts. These artifacts negatively affect the accuracy of registration by producing local optima, altering the gradient, shifting the global optimum, and making rigid registration asymmetric. In this paper, after an extensive literature review, we demonstrate the causes of the artifacts by comparing inclusion and avoidance of resampling analytically. We show the sum-of-squared-differences cost function formulated as an integral to be more accurate compared with its traditional sum form in a simple case of image registration. We then discuss aliasing that occurs in rotation, which is due to the fact that an image represented in the Cartesian grid is sampled with different rates in different directions, and propose the use of oscillatory isotropic interpolation kernels, which allow better recovery of true global optima by overcoming this type of aliasing. Through our experiments on brain, fingerprint, and white noise images, we illustrate the superior performance of the integral registration cost function in both the Cartesian and spherical coordinates, and also validate the introduced radial interpolation kernel by demonstrating the improvement in registration.
Origami-Inspired Folding of Thick, Rigid Panels

Science.gov (United States)

Trease, Brian P.; Thomson, Mark W.; Sigel, Deborah A.; Walkemeyer, Phillip E.; Zirbel, Shannon; Howell, Larry; Lang, Robert

2014-01-01

To achieve power of 250 kW or greater, a large compression ratio of stowed-to-deployed area is needed. Origami folding patterns were used to inspire the folding of a solar array to achieve synchronous deployment; however, origami models are generally created for near-zero-thickness material. Panel thickness is one of the main challenges of origami-inspired design. Three origami-inspired folding techniques (flasher, square twist, and map fold) were created with rigid panels and hinges. Hinge components are added to the model to enable folding of thick, rigid materials. Origami models are created assuming zero (or near zero) thickness. When a material with finite thickness is used, the panels are required to bend around an increasingly thick fold as they move away from the center of the model. The two approaches for dealing with material thickness are to use membrane hinges to connect the panels, or to add panel hinges, or hinges of the same thickness, at an appropriate width to enable folding.
Longitudinal double-spin asymmetry and cross section for inclusive jet production in polarized proton collisions at square root of s = 200 GeV.

Science.gov (United States)

Abelev, B I; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Benedosso, F; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, S-L; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Burton, T P; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Sánchez, M Calderón de la Barca; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Dash, S; Daugherity, M; de Moura, M M; Dedovich, T G; Dephillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Mazumdar, M R Dutta; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Ganti, M S; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D; Guertin, S M; Guimaraes, K S F F; Gupta, N; Gutierrez, T D; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Kocoloski, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; LaPointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnick, Yu; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Poljak, N; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ray, R L; Razin, S V; Reinnarth, J; Relyea, D; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sugarbaker, E; Sumbera, M; Sun, Z; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Buren, G Van; van der Kolk, N; van Leeuwen, M; Molen, A M Vander; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

2006-12-22

We report a measurement of the longitudinal double-spin asymmetry A(LL) and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at square root of s = 200 GeV. The cross section data cover transverse momenta 5 < pT < 50 GeV/c and agree with next-to-leading order perturbative QCD evaluations. The A(LL) data cover 5 < pT < 17 GeV/c and disfavor at 98% C.L. maximal positive gluon polarization in the polarized nucleon.

Rigidity of complete generic shrinking Ricci solitons

Science.gov (United States)

Chu, Yawei; Zhou, Jundong; Wang, Xue

2018-01-01

Let (Mn , g , X) be a complete generic shrinking Ricci soliton of dimension n ≥ 3. In this paper, by employing curvature inequalities, the formula of X-Laplacian for the norm square of the trace-free curvature tensor, the weak maximum principle and the estimate of the scalar curvature of (Mn , g) , we prove some rigidity results for (Mn , g , X) . In particular, it is showed that (Mn , g , X) is isometric to Rn or a finite quotient of Sn under a pointwise pinching condition. Moreover, we establish several optimal inequalities and classify those shrinking solitons for equalities.
Vortex statistics for turbulence in a container with rigid boundaries

DEFF Research Database (Denmark)

Clercx, H.J.H.; Nielsen, A.H.

2000-01-01

The evolution of vortex statistics for decaying two-dimensional turbulence in a square container with rigid no-slip walls is compared with a few available experimental results and with the scaling theory of two-dimensional turbulent decay as proposed by Carnevale et al. Power-law exponents......, computed from an ensemble average of several numerical runs, coincide with some experimentally obtained values, but not with data obtained from numerical simulations of decaying two-dimensional turbulence with periodic boundary conditions....
Understanding geological processes: Visualization of rigid and non-rigid transformations

Science.gov (United States)

Shipley, T. F.; Atit, K.; Manduca, C. A.; Ormand, C. J.; Resnick, I.; Tikoff, B.

2012-12-01

Visualizations are used in the geological sciences to support reasoning about structures and events. Research in cognitive sciences offers insights into the range of skills of different users, and ultimately how visualizations might support different users. To understand the range of skills needed to reason about earth processes we have developed a program of research that is grounded in the geosciences' careful description of the spatial and spatiotemporal patterns associated with earth processes. In particular, we are pursuing a research program that identifies specific spatial skills and investigates whether and how they are related to each other. For this study, we focus on a specific question: Is there an important distinction in the geosciences between rigid and non-rigid deformation? To study a general spatial thinking skill we employed displays with non-geological objects that had been altered by rigid change (rotation), and two types of non-rigid change ("brittle" (or discontinuous) and "ductile" (or continuous) deformation). Disciplinary scientists (geosciences and chemistry faculty), and novices (non-science faculty and undergraduate psychology students) answered questions that required them to visualize the appearance of the object before the change. In one study, geologists and chemists were found to be superior to non-science faculty in reasoning about rigid rotations (e.g., what an object would look like from a different perspective). Geologists were superior to chemists in reasoning about brittle deformations (e.g., what an object looked like before it was broken - here the object was a word cut into many fragments displaced in different directions). This finding is consistent with two hypotheses: 1) Experts are good at visualizing the types of changes required for their domain; and 2) Visualization of rigid and non-rigid changes are not the same skill. An additional important finding is that there was a broad range of skill in both rigid and non-rigid
The effect of rigid and non-rigid connections between implants and teeth on biological and technical complications: a systematic review and a meta-analysis.

Science.gov (United States)

Tsaousoglou, Phoebus; Michalakis, Konstantinos; Kang, Kiho; Weber, Hans-Peter; Sculean, Anton

2017-07-01

To assess survival, as well as technical and biological complication rates of partial fixed dental prostheses (FDPs) supported by implants and teeth. An electronic Medline search was conducted to identify articles, published in dental journals from January 1980 to August 2015, reporting on partial FDPs supported by implants and teeth. The search terms were categorized into four groups comprising the PICO question. Manual searches of published full-text articles and related reviews were also performed. The initial database search produced 3587 relevant titles. Three hundred and eighty-six articles were retrieved for abstract review, while 39 articles were selected for full-text review. A total of 10 studies were selected for inclusion. Overall survival rate for implants ranged between 90% and 100%, after follow-up periods with a mean range of 18-120 months. The survival of the abutment teeth was 94.1-100%, while the prostheses survival was 85-100% for the same time period. The most frequent complications were "periapical lesions" (11.53%). The most frequent technical complication was "porcelain occlusal fracture" (16.6%), followed by "screw loosening" (15%). According to the meta-analysis, no intrusion was noted on the rigid connection group, while five teeth (8.19%) were intruded in the non-rigid connection group [95% CI (0.013-0.151)]. The tooth-implant FDP seems to be a possible alternative to an implant-supported FDP. There is limited evidence that rigid connection between teeth and implants presents better results when compared with the non-rigid one. The major drawback of non-rigidly connected FDPs is tooth intrusion. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Preferential states of rotating turbulent flows in a square container with a step topography

NARCIS (Netherlands)

Tenreiro, M.; Trieling, R.R.; Zavala Sansón, L.; Heijst, van G.J.F.

2013-01-01

The self-organization of confined, quasi-two-dimensional turbulent flows in a rotating square container with a step-like topography is investigated by means of laboratory experiments and numerical simulations based on a rigid lid, shallow-water formulation. The domain is divided by a bottom
Rigid multibody system dynamics with uncertain rigid bodies

Energy Technology Data Exchange (ETDEWEB)

Batou, A., E-mail: anas.batou@univ-paris-est.fr; Soize, C., E-mail: christian.soize@univ-paris-est.fr [Universite Paris-Est, Laboratoire Modelisation et Simulation Multi Echelle, MSME UMR 8208 CNRS (France)

2012-03-15

This paper is devoted to the construction of a probabilistic model of uncertain rigid bodies for multibody system dynamics. We first construct a stochastic model of an uncertain rigid body by replacing the mass, the center of mass, and the tensor of inertia by random variables. The prior probability distributions of the stochastic model are constructed using the maximum entropy principle under the constraints defined by the available information. The generators of independent realizations corresponding to the prior probability distribution of these random quantities are further developed. Then several uncertain rigid bodies can be linked to each other in order to calculate the random response of a multibody dynamical system. An application is proposed to illustrate the theoretical development.
A Galerkin least squares approach to viscoelastic flow.

Energy Technology Data Exchange (ETDEWEB)

Rao, Rekha R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schunk, Peter Randall [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-10-01

A Galerkin/least-squares stabilization technique is applied to a discrete Elastic Viscous Stress Splitting formulation of for viscoelastic flow. From this, a possible viscoelastic stabilization method is proposed. This method is tested with the flow of an Oldroyd-B fluid past a rigid cylinder, where it is found to produce inaccurate drag coefficients. Furthermore, it fails for relatively low Weissenberg number indicating it is not suited for use as a general algorithm. In addition, a decoupled approach is used as a way separating the constitutive equation from the rest of the system. A Pressure Poisson equation is used when the velocity and pressure are sought to be decoupled, but this fails to produce a solution when inflow/outflow boundaries are considered. However, a coupled pressure-velocity equation with a decoupled constitutive equation is successful for the flow past a rigid cylinder and seems to be suitable as a general-use algorithm.
Measurement of inclusive jet cross sections in Z/gamma*(-->e+e-) + jets production in pp[over ] collisions at square root s = 1.96 TeV.

Science.gov (United States)

Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'orso, M; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Gerberich, H; Gerdes, D; Giagu, S; Giakoumopolou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyria, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S

2008-03-14

Inclusive jet cross sections in Z/gamma* events, with Z/gamma* decaying into an electron-positron pair, are measured as a function of jet transverse momentum and jet multiplicity in pp[over ] collisions at square root s = 1.96 TeV with the upgraded Collider Detector at Fermilab in run II, based on an integrated luminosity of 1.7 fb(-1). The measurements cover the rapidity region |y(jet)|30 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.
Measurement of the inclusive jet cross section using the kT algorithm in pp collisions at (square root s)=1.96 TeV.

Science.gov (United States)

Abulencia, A; Acosta, D; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Bachacou, H; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Ben Haim, E; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bishai, M; Blair, R E; Blocker, C; Bloom, K; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Bourov, S; Boveia, A; Brau, B; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chapman, J; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Chu, P H; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Connolly, A; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Cruz, A; Cuevas, J; Culbertson, R; Cyr, D; DaRonco, S; D'Auria, S; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Demers, S; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Dionisi, C; Dittmann, J R; Dituro, P; Dörr, C; Dominguez, A; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Ebina, K; Efron, J; Ehlers, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Flores-Castillo, L R; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Fujii, Y; Furic, I; Gajjar, A; Gallinaro, M; Galyardt, J; Garcia, J E; Garcia Sciveres, M; Garfinkel, A F; Gay, C; Gerberich, H; Gerchtein, E; Gerdes, D; Giagu, S; di Giovanni, G P; Giannetti, P; Gibson, A; Gibson, K; Ginsburg, C; Giokaris, N; Giolo, K; Giordani, M; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Haber, C; Hahn, S R; Hahn, K; Halkiadakis, E; Hamilton, A; Han, B-Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hatakeyama, K; Hauser, J; Hays, C; Hayward, H; Heijboer, A; Heinemann, B; Heinrich, J; Hennecke, M; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Huston, J; Ikado, K; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Kang, J; Karagoz-Unel, M; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, M S; Kim, S B; Kim, S H; Kim, Y K; Kirby, M; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kobayashi, H; Kondo, K; Kong, D J; Konigsberg, J; Kordas, K; Korytov, A; Kotwal, A V; Kovalev, A; Kraus, J; Kravchenko, I; Kreps, M; Kreymer, A; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kuhlmann, S E; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecci, C; Lecompte, T; Lee, J; Lee, J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Li, K; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Liu, Y; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Maksimovic, P; Manca, G; Margaroli, F; Marginean, R; Marino, C; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McGivern, D; McIntyre, P; McNamara, P; McNulty, R; Mehta, A; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; von der Mey, M; Miao, T; Miladinovic, N; Miles, J; Miller, R; Miller, J S; Mills, C; Milnik, M; Miquel, R; Miscetti, S; Mitselmakher, G; Miyamoto, A; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Mulhearn, M; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nahn, S; Nakano, I; Napier, A; Naumov, D; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Ogawa, T; Oh, S H; Oh, Y D; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Paoletti, R; Papadimitriou, V; Papikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pitts, K; Plager, C; Pondrom, L; Pope, G; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Rakitin, A; Rappoccio, S; Ratnikov, F; Reisert, B; Rekovic, V; van Remortel, N; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Rinnert, K; Ristori, L; Robertson, W J; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Rott, C; Ruiz, A; Russ, J; Rusu, V; Ryan, D; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sanchez, C; Santi, L; Sarkar, S; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Semeria, F; Sexton-Kennedy, L; Sfiligoi, I; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sill, A; Sinervo, P; Sisakyan, A; Sjolin, J; Skiba, A; Slaughter, A J; Sliwa, K; Smirnov, D; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sumorok, K; Sun, H; Suzuki, T; Taffard, A; Tafirout, R; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Tether, S; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Tönnesmann, M; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vacavant, L; Vaiciulis, A; Vallecorsa, S; Varganov, A; Vataga, E; Velev, G; Veramendi, G; Veszpremi, V; Vickey, T; Vidal, R; Vila, I; Vilar, R; Vollrath, I; Volobouev, I; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wallny, R; Walter, T; Wan, Z; Wang, M J; Wang, S M; Warburton, A; Ward, B; Waschke, S; Waters, D; Watts, T; Weber, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Worm, S; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, Y; Yang, C; Yang, U K; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zetti, F; Zhang, X; Zhou, J; Zucchelli, S

2006-03-31

We report on a measurement of the inclusive jet production cross section as a function of the jet transverse momentum in pp collisions at (square root s)=1.96 TeV using data collected with the upgraded Collider Detector at Fermilab in run II, corresponding to an integrated luminosity of 385 pb-1. The measurement is carried out for jets with rapidity 0.1
Perspectives of Teachers Regarding Inclusive Education in Ghana

Science.gov (United States)

Deku, Prosper; Vanderpuye, Irene

2017-01-01

The study explored teachers' perspectives on the curriculum, the physical environment and their preparation for the inclusive education programme. Data was collected using questionnaires. A sample of 120 teachers from schools identified as inclusive was used for the study. The t-test of independent samples and chi-square test were used to analyse…
The two-body problem of a pseudo-rigid body and a rigid sphere

DEFF Research Database (Denmark)

Kristiansen, Kristian Uldall; Vereshchagin, M.; Gózdziewski, K.

2012-01-01

n this paper we consider the two-body problem of a spherical pseudo-rigid body and a rigid sphere. Due to the rotational and "re-labelling" symmetries, the system is shown to possess conservation of angular momentum and circulation. We follow a reduction procedure similar to that undertaken...... in the study of the two-body problem of a rigid body and a sphere so that the computed reduced non-canonical Hamiltonian takes a similar form. We then consider relative equilibria and show that the notions of locally central and planar equilibria coincide. Finally, we show that Riemann's theorem on pseudo......-rigid bodies has an extension to this system for planar relative equilibria....
Rigid Body Sampling and Individual Time Stepping for Rigid-Fluid Coupling of Fluid Simulation

Directory of Open Access Journals (Sweden)

Xiaokun Wang

2017-01-01

Full Text Available In this paper, we propose an efficient and simple rigid-fluid coupling scheme with scientific programming algorithms for particle-based fluid simulation and three-dimensional visualization. Our approach samples the surface of rigid bodies with boundary particles that interact with fluids. It contains two procedures, that is, surface sampling and sampling relaxation, which insures uniform distribution of particles with less iterations. Furthermore, we present a rigid-fluid coupling scheme integrating individual time stepping to rigid-fluid coupling, which gains an obvious speedup compared to previous method. The experimental results demonstrate the effectiveness of our approach.
Rigidity and resistance of larval- and adult schistosomes-medium interface

Energy Technology Data Exchange (ETDEWEB)

Migliardo, Federica, E-mail: fmigliardo@unime.it [Department of Physics and Earth Sciences, University of Messina, 98166 Messina (Italy); Tallima, Hatem; El Ridi, Rashika [Zoology Department, Faculty of Science, Cairo University, Cairo 12613 (Egypt)

2014-03-28

Graphical abstract: - Highlights: • Schistosoma larvae and worms are studied by neutron scattering. • Measurements on larvae were repeated after one day and by increasing temperature. • The flexibility properties of larvae and adult parasites are compared. • The parasite rigidity is related to their resistance to the hostile environment. • Insight into the parasite defense mechanisms to the immune system attack is achieved. - Abstract: Schistosomiasis is second only to malaria in prevalence and severity, and is still a major health problem in many tropical countries worldwide with about 200–300 million cases and with more than 800 million people at risk of infection. Based on these data, the World Health Organization recommends fostering research efforts for understanding at any level the mechanisms of the infection and then decreasing the social and economical impact of schistosomiasis. A key role is played by the parasite apical lipid membrane, which is entirely impervious to the surrounding elements of the immune system. We have previously demonstrated that the interaction between schistosomes and surrounding medium is governed by a parasite surface membrane sphingomyelin-based hydrogen barrier. In the present article, the elastic contribution to the total motion as a function of the exchanged wave-vector Q and the mean square displacement values for Schistosoma mansoni larvae and worms and Schistosomahaematobium worms have been evaluated by quasi elastic neutron scattering (QENS). The results point out that S. mansoni larvae show a smaller mean square displacement in comparison to S. mansoni and S. haematobium worms. These values increased by repeating the measurements after one day. These differences, which are analogous to those observed for the diffusion coefficient we previously evaluated, are interpreted in terms of rigidity of the parasite-medium interaction. S. mansoni larvae are the most rigid systems, while S. haematobium worms are the most
Effects of shape and size of inclusions on the sintering of ZnO-ZrO2 composites

International Nuclear Information System (INIS)

Nakada, Yohsuke; Kimura, Toshio

1997-01-01

The densification behavior and microstructure development of ZnO matrices containing rigid ZrO 2 inclusions were studied, with special emphasis on the effect of inclusion shape and size. The inclusions retarded the densification of the matrix, regardless of the inclusion shape and size. For large inclusions with diameter of > 10 microm, dense regions developed between inclusion particles. The inclusion particles and dense regions formed a continuous network, which constrained the densification of the composites. The inclusion shape had a small effect on the development of dense regions. Severe retardation in densification was observed for compacts containing inclusions with diameters of < 10 microm. In these cases, dense regions between inclusion particles did not develop. The formation of the continuous network cannot be applicable to small inclusions as an origin of retardation of densification
Efficient Constrained Local Model Fitting for Non-Rigid Face Alignment.

Science.gov (United States)

Lucey, Simon; Wang, Yang; Cox, Mark; Sridharan, Sridha; Cohn, Jeffery F

2009-11-01

Active appearance models (AAMs) have demonstrated great utility when being employed for non-rigid face alignment/tracking. The "simultaneous" algorithm for fitting an AAM achieves good non-rigid face registration performance, but has poor real time performance (2-3 fps). The "project-out" algorithm for fitting an AAM achieves faster than real time performance (> 200 fps) but suffers from poor generic alignment performance. In this paper we introduce an extension to a discriminative method for non-rigid face registration/tracking referred to as a constrained local model (CLM). Our proposed method is able to achieve superior performance to the "simultaneous" AAM algorithm along with real time fitting speeds (35 fps). We improve upon the canonical CLM formulation, to gain this performance, in a number of ways by employing: (i) linear SVMs as patch-experts, (ii) a simplified optimization criteria, and (iii) a composite rather than additive warp update step. Most notably, our simplified optimization criteria for fitting the CLM divides the problem of finding a single complex registration/warp displacement into that of finding N simple warp displacements. From these N simple warp displacements, a single complex warp displacement is estimated using a weighted least-squares constraint. Another major advantage of this simplified optimization lends from its ability to be parallelized, a step which we also theoretically explore in this paper. We refer to our approach for fitting the CLM as the "exhaustive local search" (ELS) algorithm. Experiments were conducted on the CMU Multi-PIE database.
Soft inclusion in a confined fluctuating active gel

Science.gov (United States)

Singh Vishen, Amit; Rupprecht, J.-F.; Shivashankar, G. V.; Prost, J.; Rao, Madan

2018-03-01

We study stochastic dynamics of a point and extended inclusion within a one-dimensional confined active viscoelastic gel. We show that the dynamics of a point inclusion can be described by a Langevin equation with a confining potential and multiplicative noise. Using a systematic adiabatic elimination over the fast variables, we arrive at an overdamped equation with a proper definition of the multiplicative noise. To highlight various features and to appeal to different biological contexts, we treat the inclusion in turn as a rigid extended element, an elastic element, and a viscoelastic (Kelvin-Voigt) element. The dynamics for the shape and position of the extended inclusion can be described by coupled Langevin equations. Deriving exact expressions for the corresponding steady-state probability distributions, we find that the active noise induces an attraction to the edges of the confining domain. In the presence of a competing centering force, we find that the shape of the probability distribution exhibits a sharp transition upon varying the amplitude of the active noise. Our results could help understanding the positioning and deformability of biological inclusions, e.g., organelles in cells, or nucleus and cells within tissues.
Rigidly foldable origami gadgets and tessellations

Science.gov (United States)

Evans, Thomas A.; Lang, Robert J.; Magleby, Spencer P.; Howell, Larry L.

2015-01-01

Rigidly foldable origami allows for motion where all deflection occurs at the crease lines and facilitates the application of origami in materials other than paper. In this paper, we use a recently discovered method for determining rigid foldability to identify existing flat-foldable rigidly foldable tessellations, which are also categorized. We introduce rigidly foldable origami gadgets which may be used to modify existing tessellations or to create new tessellations. Several modified and new rigidly foldable tessellations are presented. PMID:26473037
On the mean square displacements (MSD) of Hg and Te in HgTe

International Nuclear Information System (INIS)

Madhavan, Y.; Ramachandran, K.

1989-01-01

The mean square displacements (MSD) of Hg and Te in the perfect system of HgTe are worked out in the modified rigid ion model of Plumelle and Vandevyver. Also the MSD of Hg and Te neighbours around anion and cation vacancies in HgTe are worked out giving an active role for the vacancy following the theory of Maradudin et al. The results are compared with experimental values. (author)
Tile-based rigidization surface parametric design study

Science.gov (United States)

Giner Munoz, Laura; Luntz, Jonathan; Brei, Diann; Kim, Wonhee

2018-03-01

Inflatable technologies have proven useful in consumer goods as well as in more recent applications including civil structures, aerospace, medical, and robotics. However, inflatable technologies are typically lacking in their ability to provide rigid structural support. Particle jamming improves upon this by providing structures which are normally flexible and moldable but become rigid when air is removed. Because these are based on an airtight bladder filled with loose particles, they always occupy the full volume of its rigid state, even when not rigidized. More recent developments in layer jamming have created thin, compact rigidizing surfaces replacing the loose volume of particles with thinly layered surface materials. Work in this area has been applied to several specific applications with positive results but have not generally provided the broader understanding of the rigidization performance as a function of design parameters required for directly adapting layer rigidization technology to other applications. This paper presents a parametric design study of a new layer jamming vacuum rigidization architecture: tile-based vacuum rigidization. This form of rigidization is based on layers of tiles contained within a thin vacuum bladder which can be bent, rolled, or otherwise compactly stowed, but when deployed flat, can be vacuumed and form a large, flat, rigid plate capable of supporting large forces both localized and distributed over the surface. The general architecture and operation detailing rigidization and compliance mechanisms is introduced. To quantitatively characterize the rigidization behavior, prototypes rigidization surfaces are fabricated and an experimental technique is developed based on a 3-point bending test. Performance evaluation metrics are developed to describe the stiffness, load-bearing capacity, and internal slippage of tested prototypes. A set of experimental parametric studies are performed to better understand the impact of
Transition to chaos in a square enclosure containing internal heat sources

Energy Technology Data Exchange (ETDEWEB)

Baytas, A.C. [Institute For Nuclear Energy, Istanbul (Turkey)

1995-09-01

A numerical investigation is performed to study the transition from steady to chaotic flow of a fluid confined in a two-dimensional square cavity. The cavity has rigid walls of constant temperature containing uniformly distributed internal heat source. Effects of the Rayleigh number of flow and heat transfer rates are studied. In addition to, same problem is solved for sinusoidally changing internal heat source to show its effect on the flow model and heat transfer of the enclosures. Details of oscillatory solutions and flow bifurcations are presented.

Résistance d'un composite à renforts rigides : le cas d'une matrice de Drucker Prager avec règle d'écoulement plastique non associée

Science.gov (United States)

Dormieux, Luc; Barthélémy, Jean-François; Maghous, Samir

2006-02-01

A rigid plastic behavior characterized by a failure criterion of the Drucker-Prager type and a non associated flow rule is considered. The latter can be viewed formally as the limit of a sequence of viscous behaviors with isotropic prestress. The limit states of a composite made up of such a material reinforced by rigid inclusions are then determined. The latter lie on a Drucker-Prager cone which friction coefficient is greater than that of the matrix and depends on the characteristics of the strength and of the flow rule of the matrix, as well as on the volume fraction of the inclusions. To cite this article: L. Dormieux et al., C. R. Mecanique 334 (2006).
Dimensionality controls cytoskeleton assembly and metabolism of fibroblast cells in response to rigidity and shape.

Directory of Open Access Journals (Sweden)

Mirjam Ochsner

2010-03-01

Full Text Available Various physical parameters, including substrate rigidity, size of adhesive islands and micro-and nano-topographies, have been shown to differentially regulate cell fate in two-dimensional (2-D cell cultures. Cells anchored in a three-dimensional (3-D microenvironment show significantly altered phenotypes, from altered cell adhesions, to cell migration and differentiation. Yet, no systematic analysis has been performed that studied how the integrated cellular responses to the physical characteristics of the environment are regulated by dimensionality (2-D versus 3-D.Arrays of 5 or 10 microm deep microwells were fabricated in polydimethylsiloxane (PDMS. The actin cytoskeleton was compared for single primary fibroblasts adhering either to microfabricated adhesive islands (2-D or trapped in microwells (3-D of controlled size, shape, and wall rigidity. On rigid substrates (Young's Modulus = 1 MPa, cytoskeleton assembly within single fibroblast cells occurred in 3-D microwells of circular, rectangular, square, and triangular shapes with 2-D projected surface areas (microwell bottom surface area and total surface areas of adhesion (microwell bottom plus wall surface area that inhibited stress fiber assembly in 2-D. In contrast, cells did not assemble a detectable actin cytoskeleton in soft 3-D microwells (20 kPa, regardless of their shapes, but did so on flat, 2-D substrates. The dependency on environmental dimensionality was also reflected by cell viability and metabolism as probed by mitochondrial activities. Both were upregulated in 3-D cultured cells versus cells on 2-D patterns when surface area of adhesion and rigidity were held constant.These data indicate that cell shape and rigidity are not orthogonal parameters directing cell fate. The sensory toolbox of cells integrates mechanical (rigidity and topographical (shape and dimensionality information differently when cell adhesions are confined to 2-D or occur in a 3-D space.
Interaction between a punch and an arbitrary crack or inclusion in a transversely isotropic half-space

Science.gov (United States)

Fabrikant, I.; Karapetian, E.; Kalinin, S. V.

2018-02-01

We consider the problem of an arbitrary shaped rigid punch pressed against the boundary of a transversely isotropic half-space and interacting with an arbitrary flat crack or inclusion, located in the plane parallel to the boundary. The set of governing integral equations is derived for the most general conditions, namely the presence of both normal and tangential stresses under the punch, as well as general loading of the crack faces. In order to verify correctness of the derivations, two different methods were used to obtain governing integral equations: generalized method of images and utilization of the reciprocal theorem. Both methods gave the same results. Axisymmetric coaxial case of interaction between a rigid inclusion and a flat circular punch both centered along the z-axis is considered as an illustrative example. Most of the final results are presented in terms of elementary functions.
Inclusive charged particle production at large angles at the CERN ISR

CERN Document Server

Alper, B; Booth, P; Bulos, F; Carroll, L J; Damgaard, G; Duff, Brian G; Heymann, Franz F; Jackson, J N; Jarlskog, G; Jönsson, L B; Klovning, A; Leistam, L; Lillethun, E; Lynch, G; Manning, Geoffrey; Prentice, M; Quarrie, D; von Dardel, Guy F; Weiss, J M

1973-01-01

Three different sets of results are presented: 1. Data on the inclusive production of pi /sup +or-/, K/sup +or-/, p, and p, at low transverse momenta over an angular range of 29 degrees to 90 degrees in the centre-of-mass system and for centre-of-mass energies square root s=31 and 53 GeV. 2. Results from a search for massive particles at 62.5 degrees in the laboratory, square root s=53 GeV-in particular, cross-sections for the production of deuterons and antideuterons are given. 3. Data on inclusive charged particle production of high transverse momentum P/sub T/ between 1.5 and 4.4 GeV/c, at centre-of- mass angles 59.4 degrees and 90 degrees , square root s=44 and 53 GeV. In addition, preliminary measurements have been made at square root s =31 and 44 GeV of pi /sup +or-/, K/sup +or-/, p, and p production ratios at 90 degrees for p/sub T/ between 2.0 and 3.5 GeV.c. (14 refs) .
Rigidity and symmetry

CERN Document Server

Weiss, Asia; Whiteley, Walter

2014-01-01

This book contains recent contributions to the fields of rigidity and symmetry with two primary focuses: to present the mathematically rigorous treatment of rigidity of structures, and to explore the interaction of geometry, algebra, and combinatorics. Overall, the book shows how researchers from diverse backgrounds explore connections among the various discrete structures with symmetry as the unifying theme. Contributions present recent trends and advances in discrete geometry, particularly in the theory of polytopes. The rapid development of abstract polytope theory has resulted in a rich theory featuring an attractive interplay of methods and tools from discrete geometry, group theory, classical geometry, hyperbolic geometry and topology. The volume will also be a valuable source as an introduction to the ideas of both combinatorial and geometric rigidity theory and its applications, incorporating the surprising impact of symmetry. It will appeal to students at both the advanced undergraduate and gradu...
Birationally rigid varieties

CERN Document Server

Pukhlikov, Aleksandr

2013-01-01

Birational rigidity is a striking and mysterious phenomenon in higher-dimensional algebraic geometry. It turns out that certain natural families of algebraic varieties (for example, three-dimensional quartics) belong to the same classification type as the projective space but have radically different birational geometric properties. In particular, they admit no non-trivial birational self-maps and cannot be fibred into rational varieties by a rational map. The origins of the theory of birational rigidity are in the work of Max Noether and Fano; however, it was only in 1970 that Iskovskikh and Manin proved birational superrigidity of quartic three-folds. This book gives a systematic exposition of, and a comprehensive introduction to, the theory of birational rigidity, presenting in a uniform way, ideas, techniques, and results that so far could only be found in journal papers. The recent rapid progress in birational geometry and the widening interaction with the neighboring areas generate the growing interest ...
Occupation probabilities and fluctuations in the asymmetric simple inclusion process

Science.gov (United States)

Reuveni, Shlomi; Hirschberg, Ori; Eliazar, Iddo; Yechiali, Uri

2014-04-01

The asymmetric simple inclusion process (ASIP), a lattice-gas model of unidirectional transport and aggregation, was recently proposed as an "inclusion" counterpart of the asymmetric simple exclusion process. In this paper we present an exact closed-form expression for the probability that a given number of particles occupies a given set of consecutive lattice sites. Our results are expressed in terms of the entries of Catalan's trapezoids—number arrays which generalize Catalan's numbers and Catalan's triangle. We further prove that the ASIP is asymptotically governed by the following: (i) an inverse square-root law of occupation, (ii) a square-root law of fluctuation, and (iii) a Rayleigh law for the distribution of interexit times. The universality of these results is discussed.
Jammed packings of deformable and rigid 2D spherocylinders and spheropolygons

Science.gov (United States)

Shattuck, Mark

We study mechanically stable packings of deformable and rigid 2D spheropolygons using computer simulation. A 2D sphereopolygon is a particle shape formed by the collection of all points within a perpendicular distance r from the edge of a polygon. It is a generalization of the 2D spherocylinder and a circle, which are the collection of all points within a distance r from a line and a point. In our model, the spheropolygon can be deformable. The lengths of the sides are fixed, but the angles are only constrained by the requirement that the shape factor, S = 4 πA /p2 is fixed, where A is the area of the polygon and p is the perimeter. The particles can be made rigid by requiring that the shape factor is the maximum possible for the edge length ratios. For example, the maximum for a square is S = π /4. We present densities and average contact numbers for collections of mono- and bi-disperse packings of spheropolygons for a range of shape factors, edge numbers, and system sizes. We find mechically stable packings with fewer than isostatic contacts.
Rigidity of Glasses and Macromolecules

Science.gov (United States)

Thorpe, M. F.

1998-03-01

The simple yet powerful ideas of percolation theory have found their way into many different areas of research. In this talk we show how RIGIDITY PERCOLATION can be studied at a similar level of sophistication, using a powerful new program THE PEBBLE GAME (D. J. Jacobs and M. F. Thorpe, Phys. Rev. E) 53, 3682 (1996). that uses an integer algorithm. This program can analyse the rigidity of two and three dimensional networks containing more than one million bars and joints. We find the total number of floppy modes, and find the critical behavior as the network goes from floppy to rigid as more bars are added. We discuss the relevance of this work to network glasses, and how it relates to experiments that involve the mechanical properties like hardness and elasticity of covalent glassy networks like Ge_xAs_ySe_1-x-y and dicuss recent experiments that suggest that the rigidity transition may be first order (Xingwei Feng, W. J.Bresser and P. Boolchand, Phys. Rev. Lett 78), 4422 (1997).. This approach is also useful in macromolecules and proteins, where detailed information about the rigid domain structure can be obtained.
Rigidity-tuning conductive elastomer

Science.gov (United States)

Shan, Wanliang; Diller, Stuart; Tutcuoglu, Abbas; Majidi, Carmel

2015-06-01

We introduce a conductive propylene-based elastomer (cPBE) that rapidly and reversibly changes its mechanical rigidity when powered with electrical current. The elastomer is rigid in its natural state, with an elastic (Young’s) modulus of 175.5 MPa, and softens when electrically activated. By embedding the cPBE in an electrically insulating sheet of polydimethylsiloxane (PDMS), we create a cPBE-PDMS composite that can reversibly change its tensile modulus between 37 and 1.5 MPa. The rigidity change takes ˜6 s and is initiated when a 100 V voltage drop is applied across the two ends of the cPBE film. This magnitude of change in elastic rigidity is similar to that observed in natural skeletal muscle and catch connective tissue. We characterize the tunable load-bearing capability of the cPBE-PDMS composite with a motorized tensile test and deadweight experiment. Lastly, we demonstrate the ability to control the routing of internal forces by embedding several cPBE-PDMS ‘active tendons’ into a soft robotic pneumatic bending actuator. Selectively activating the artificial tendons controls the neutral axis and direction of bending during inflation.
Rigidity-tuning conductive elastomer

International Nuclear Information System (INIS)

Shan, Wanliang; Diller, Stuart; Tutcuoglu, Abbas; Majidi, Carmel

2015-01-01

We introduce a conductive propylene-based elastomer (cPBE) that rapidly and reversibly changes its mechanical rigidity when powered with electrical current. The elastomer is rigid in its natural state, with an elastic (Young’s) modulus of 175.5 MPa, and softens when electrically activated. By embedding the cPBE in an electrically insulating sheet of polydimethylsiloxane (PDMS), we create a cPBE–PDMS composite that can reversibly change its tensile modulus between 37 and 1.5 MPa. The rigidity change takes ∼6 s and is initiated when a 100 V voltage drop is applied across the two ends of the cPBE film. This magnitude of change in elastic rigidity is similar to that observed in natural skeletal muscle and catch connective tissue. We characterize the tunable load-bearing capability of the cPBE–PDMS composite with a motorized tensile test and deadweight experiment. Lastly, we demonstrate the ability to control the routing of internal forces by embedding several cPBE–PDMS ‘active tendons’ into a soft robotic pneumatic bending actuator. Selectively activating the artificial tendons controls the neutral axis and direction of bending during inflation. (paper)
On flexible and rigid nouns

DEFF Research Database (Denmark)

Rijkhoff, Jan

2010-01-01

classes. Finally this article wants to claim that the distinction between rigid and flexible noun categories (a) adds a new dimension to current classifications of parts of speech systems, (b) correlates with certain grammatical phenomena (e.g. so-called number discord), and (c) helps to explain the parts......This article argues that in addition to the major flexible lexical categories in Hengeveld’s classification of parts of speech systems (Contentive, Non-Verb, Modifier), there are also flexible word classes within the rigid lexical category Noun (Set Noun, Sort Noun, General Noun). Members...... by the flexible item in the external world. I will then argue that flexible word classes constitute a proper category (i.e. they are not the result of a merger of some rigid word classes) in that members of flexible word categories display the same properties regarding category membership as members of rigid word...
CT-3DRA registration for radiosurgery treatments: a comparison among rigid, affine and non rigid approaches

International Nuclear Information System (INIS)

Stancanello, J.; Loeckx, D.; Francescon, P.; Calvedon, C.; Avanzo, M.; Cora, S.; Scalchi, P.; Cerveri, P.; Ferrigno, G.

2004-01-01

This work aims at comparing rigid, affine and Local Non Rigid (LNR) CT-3D Rotational Angiography (CT-3DRA) registrations based on mutual information. 10 cranial and 1 spinal cases have been registered by rigid and affine transformations; while LNR has been applied to the cases where residual deformation must be corrected. An example of CT-3DRA registration without regularization term and an example of LNR using the similarity criterion and the regularization term as well as 3D superposition of the 3DRA before and after the registration without the regularization term are presented. All the registrations performed by rigid transformation converged to an acceptable solution. The results about the robustness test in axial direction are reported. Conclusions: For cranial cases, affine transformation endowed with threshold-segmentation pre-processing can be considered the most favourable solution for almost all registrations; for some cases, LNR provides more accurate results. For the spinal case rigid transformation is the most suitable when immobilizing patient during examinations; in this case the increase of accuracy by using LNR registrations seems to be not significant
Torsional Rigidity of Minimal Submanifolds

DEFF Research Database (Denmark)

Markvorsen, Steen; Palmer, Vicente

2006-01-01

We prove explicit upper bounds for the torsional rigidity of extrinsic domains of minimal submanifolds $P^m$ in ambient Riemannian manifolds $N^n$ with a pole $p$. The upper bounds are given in terms of the torsional rigidities of corresponding Schwarz symmetrizations of the domains in warped...
Flexible and rigid cystoscopy in women.

Science.gov (United States)

Gee, Jason R; Waterman, Bradley J; Jarrard, David F; Hedican, Sean P; Bruskewitz, Reginald C; Nakada, Stephen Y

2009-01-01

Previous studies have evaluated the tolerability of rigid versus flexible cystoscopy in men. Similar studies, however, have not been performed in women. We sought to determine whether office-based flexible cystoscopy was better tolerated than rigid cystoscopy in women. Following full IRB approval, women were prospectively randomized in a single-blind manner. Patients were randomized to flexible or rigid cystoscopy and draped in the lithotomy position to maintain blinding of the study. Questionnaires evaluated discomfort before, during, and after cystoscopy. Thirty-six women were randomized to flexible (18) or rigid (18) cystoscopy. Indications were surveillance (16), hematuria (15), recurrent UTIs (2), voiding dysfunction (1), and other (2). All questionnaires were returned by 31/36 women. Using a 10-point visual analog scale (VAS), median discomfort during the procedure for flexible and rigid cystoscopy were 1.4 and 1.8, respectively, in patients perceiving pain. Median recalled pain 1 week later was similar at 0.8 and 1.15, respectively. None of these differences were statistically significant. Flexible and rigid cystoscopy are well tolerated in women. Discomfort during and after the procedure is minimal in both groups. Urologists should perform either procedure in women based on their preference and skill level.
Analysis of Switched-Rigid Floating Oscillator

Directory of Open Access Journals (Sweden)

Prabhakar R. Marur

2009-01-01

Full Text Available In explicit finite element simulations, a technique called deformable-to-rigid (D2R switching is used routinely to reduce the computation time. Using the D2R option, the deformable parts in the model can be switched to rigid and reverted back to deformable when needed during the analysis. The time of activation of D2R however influences the overall dynamics of the system being analyzed. In this paper, a theoretical basis for the selection of time of rigid switching based on system energy is established. A floating oscillator problem is investigated for this purpose and closed-form analytical expressions are derived for different phases in rigid switching. The analytical expressions are validated by comparing the theoretical results with numerical computations.
Torsional rigidity, isospectrality and quantum graphs

International Nuclear Information System (INIS)

Colladay, Don; McDonald, Patrick; Kaganovskiy, Leon

2017-01-01

We study torsional rigidity for graph and quantum graph analogs of well-known pairs of isospectral non-isometric planar domains. We prove that such isospectral pairs are distinguished by torsional rigidity. (paper)
A method for measuring the inertia properties of rigid bodies

Science.gov (United States)

Gobbi, M.; Mastinu, G.; Previati, G.

2011-01-01

A method for the measurement of the inertia properties of rigid bodies is presented. Given a rigid body and its mass, the method allows to measure (identify) the centre of gravity location and the inertia tensor during a single test. The proposed technique is based on the analysis of the free motion of a multi-cable pendulum to which the body under consideration is connected. The motion of the pendulum and the forces acting on the system are recorded and the inertia properties are identified by means of a proper mathematical procedure based on a least square estimation. After the body is positioned on the test rig, the full identification procedure takes less than 10 min. The natural frequencies of the pendulum and the accelerations involved are quite low, making this method suitable for many practical applications. In this paper, the proposed method is described and two test rigs are presented: the first is developed for bodies up to 3500 kg and the second for bodies up to 400 kg. A validation of the measurement method is performed with satisfactory results. The test rig holds a third part quality certificate according to an ISO 9001 standard and could be scaled up to measure the inertia properties of huge bodies, such as trucks, airplanes or even ships.
Rigidity of monodromies for Appell's hypergeometric functions

Directory of Open Access Journals (Sweden)

Yoshishige Haraoka

2015-01-01

Full Text Available For monodromy representations of holonomic systems, the rigidity can be defined. We examine the rigidity of the monodromy representations for Appell's hypergeometric functions, and get the representations explicitly. The results show how the topology of the singular locus and the spectral types of the local monodromies work for the study of the rigidity.
Binary circular inclusions in an effective medium approximation

Energy Technology Data Exchange (ETDEWEB)

Alexopoulos, A. [Electronic Warfare and Radar Division, Defence Science and Technology Organisation (DSTO), P.O. Box 1500, Edinburgh 5111 (Australia)]. E-mail: aris.alexopoulos@dsto.defence.gov.au

2005-05-02

We investigate the second order interactions of perfectly-conducting circular inclusions embedded in a medium of dielectric constant {epsilon}{sub 0} under the influence of an electric field E{sub 0}. Using dipole theory we show that the potential difference for the composite system is written in terms of complicated continued fractions. The form of these continued fractions is rederived in terms of simple square matrices which simplify the computationally intense interaction terms between the two inclusions. Asymptotic expressions are derived from the continued fractions that are then used to calculate the conductance of the medium.

From Wage Rigidities to Labour Market Rigidities: A Turning-Point in Explaining Equilibrium Unemployment?

OpenAIRE

Marco Guerrazzi; Nicola Meccheri

2009-01-01

This paper offers a critical discussion of the concept of labour market rigidity relevant to explaining unemployment. Starting from Keynes’s own view, we discuss how the concept of labour market flexibility has changed over time, involving nominal or real wage flexibility, contract flexibility or labour market institution flexibility. We also provide a critical assessment of the factors that lead the search framework highlighting labour market rigidities (frictions) to challenge the more wide...
Experimental demonstrations in audible frequency range of band gap tunability and negative refraction in two-dimensional sonic crystal.

Science.gov (United States)

Pichard, Hélène; Richoux, Olivier; Groby, Jean-Philippe

2012-10-01

The propagation of audible acoustic waves in two-dimensional square lattice tunable sonic crystals (SC) made of square cross-section infinitely rigid rods embedded in air is investigated experimentally. The band structure is calculated with the plane wave expansion (PWE) method and compared with experimental measurements carried out on a finite extend structure of 200 cm width, 70 cm depth and 15 cm height. The structure is made of square inclusions of 5 cm side with a periodicity of L = 7.5 cm placed inbetween two rigid plates. The existence of tunable complete band gaps in the audible frequency range is demonstrated experimentally by rotating the scatterers around their vertical axis. Negative refraction is then analyzed by use of the anisotropy of the equi-frequency surface (EFS) in the first band and of a finite difference time domain (FDTD) method. Experimental results finally show negative refraction in the audible frequency range.
Creating Magic Squares.

Science.gov (United States)

Lyon, Betty Clayton

1990-01-01

One method of making magic squares using a prolongated square is illustrated. Discussed are third-order magic squares, fractional magic squares, fifth-order magic squares, decimal magic squares, and even magic squares. (CW)
The effect of the lateral interactions on the critical behavior of long straight rigid rods on two-dimensional lattices

Directory of Open Access Journals (Sweden)

A. J. Ramirez-Pastor

2009-09-01

Full Text Available Using Monte Carlo simulations and finite-size scaling analysis, the critical behavior of attractive rigid rods of length $k$ ($k$-mers on square lattices at intermediate density has been studied. A nematic phase, characterized by a big domain of parallel $k$-mers, was found. This ordered phase is separated from the isotropic state by a continuous transition occurring at a intermediate density $heta_c$, which increases linearly with the magnitude of the lateral interactions.
Using Squares to Sum Squares

Science.gov (United States)

DeTemple, Duane

2010-01-01

Purely combinatorial proofs are given for the sum of squares formula, 1[superscript 2] + 2[superscript 2] + ... + n[superscript 2] = n(n + 1) (2n + 1) / 6, and the sum of sums of squares formula, 1[superscript 2] + (1[superscript 2] + 2[superscript 2]) + ... + (1[superscript 2] + 2[superscript 2] + ... + n[superscript 2]) = n(n + 1)[superscript 2]…
Bending and splitting of spoof surface acoustic waves through structured rigid surface

Directory of Open Access Journals (Sweden)

Sujun Xie

2018-03-01

Full Text Available In this paper, we demonstrated that a 90°-bended imaging of spoof surface acoustic waves with subwavelength resolution of 0.316λ can be realized by a 45° prism-shaped surface phononic crystal (SPC, which is composed of borehole arrays with square lattice in a rigid plate. Furthermore, by combining two identical prism-shaped phononic crystal to form an interface (to form a line-defect, the excited spoof surface acoustic waves can be split into bended and transmitted parts. The power ratio between the bended and transmitted surface waves can be tuned arbitrarily by adjusting the defect size. This acoustic system is believed to have potential applications in various multifunctional acoustic solutions integrated by different acoustical devices.
Simulations of ferrofluid dynamics: Rigid dipoles model versus particles with internal degrees of freedom

International Nuclear Information System (INIS)

Berkov, D.V.; Gorn, N.L.; Stock, D.

2007-01-01

For numerical studies of a ferrofluid dynamics we have developed a model which includes internal magnetic degrees of freedom of ferrofluid particles. Contrary to standard models, we take into account that the magnetocrystalline anisotropy of a ferrofluid particle material is finite, so that the particle moment is allowed to rotate with respect to the particle itself. Simulating magnetization relaxation of a ferrofluid after switching off the external field and comparing results with those obtained for rigid dipoles model, we demonstrate that for anisotropy typical for commonly used ferrofluid materials inclusion of 'magnetic' degrees of freedom is essential for a correct description of ferrofluid dynamics
Nonlinear behavior of matrix-inclusion composites under high confining pressure: application to concrete and mortar

Science.gov (United States)

Le, Tuan Hung; Dormieux, Luc; Jeannin, Laurent; Burlion, Nicolas; Barthélémy, Jean-François

2008-08-01

This paper is devoted to a micromechanics-based simulation of the response of concrete to hydrostatic and oedometric compressions. Concrete is described as a composite made up of a cement matrix in which rigid inclusions are embedded. The focus is put on the role of the interface between matrix and inclusion which represent the interfacial transition zone (ITZ). A plastic behavior is considered for both the matrix and the interfaces. The effective response of the composite is derived from the modified secant method adapted to the situation of imperfect interfaces. To cite this article: T.H. Le et al., C. R. Mecanique 336 (2008).
Large scale Brownian dynamics of confined suspensions of rigid particles

Science.gov (United States)

Sprinkle, Brennan; Balboa Usabiaga, Florencio; Patankar, Neelesh A.; Donev, Aleksandar

2017-12-01

We introduce methods for large-scale Brownian Dynamics (BD) simulation of many rigid particles of arbitrary shape suspended in a fluctuating fluid. Our method adds Brownian motion to the rigid multiblob method [F. Balboa Usabiaga et al., Commun. Appl. Math. Comput. Sci. 11(2), 217-296 (2016)] at a cost comparable to the cost of deterministic simulations. We demonstrate that we can efficiently generate deterministic and random displacements for many particles using preconditioned Krylov iterative methods, if kernel methods to efficiently compute the action of the Rotne-Prager-Yamakawa (RPY) mobility matrix and its "square" root are available for the given boundary conditions. These kernel operations can be computed with near linear scaling for periodic domains using the positively split Ewald method. Here we study particles partially confined by gravity above a no-slip bottom wall using a graphical processing unit implementation of the mobility matrix-vector product, combined with a preconditioned Lanczos iteration for generating Brownian displacements. We address a major challenge in large-scale BD simulations, capturing the stochastic drift term that arises because of the configuration-dependent mobility. Unlike the widely used Fixman midpoint scheme, our methods utilize random finite differences and do not require the solution of resistance problems or the computation of the action of the inverse square root of the RPY mobility matrix. We construct two temporal schemes which are viable for large-scale simulations, an Euler-Maruyama traction scheme and a trapezoidal slip scheme, which minimize the number of mobility problems to be solved per time step while capturing the required stochastic drift terms. We validate and compare these schemes numerically by modeling suspensions of boomerang-shaped particles sedimented near a bottom wall. Using the trapezoidal scheme, we investigate the steady-state active motion in dense suspensions of confined microrollers, whose
Thermostability in rubredoxin and its relationship to mechanical rigidity

Science.gov (United States)

Rader, A. J.

2010-03-01

The source of increased stability in proteins from organisms that thrive in extreme thermal environments is not well understood. Previous experimental and theoretical studies have suggested many different features possibly responsible for such thermostability. Many of these thermostabilizing mechanisms can be accounted for in terms of structural rigidity. Thus a plausible hypothesis accounting for this remarkable stability in thermophilic enzymes states that these enzymes have enhanced conformational rigidity at temperatures below their native, functioning temperature. Experimental evidence exists to both support and contradict this supposition. We computationally investigate the relationship between thermostability and rigidity using rubredoxin as a case study. The mechanical rigidity is calculated using atomic models of homologous rubredoxin structures from the hyperthermophile Pyrococcus furiosus and mesophile Clostridium pasteurianum using the FIRST software. A global increase in structural rigidity (equivalently a decrease in flexibility) corresponds to an increase in thermostability. Locally, rigidity differences (between mesophilic and thermophilic structures) agree with differences in protection factors.
Thermostability in rubredoxin and its relationship to mechanical rigidity

International Nuclear Information System (INIS)

Rader, A J

2010-01-01

The source of increased stability in proteins from organisms that thrive in extreme thermal environments is not well understood. Previous experimental and theoretical studies have suggested many different features possibly responsible for such thermostability. Many of these thermostabilizing mechanisms can be accounted for in terms of structural rigidity. Thus a plausible hypothesis accounting for this remarkable stability in thermophilic enzymes states that these enzymes have enhanced conformational rigidity at temperatures below their native, functioning temperature. Experimental evidence exists to both support and contradict this supposition. We computationally investigate the relationship between thermostability and rigidity using rubredoxin as a case study. The mechanical rigidity is calculated using atomic models of homologous rubredoxin structures from the hyperthermophile Pyrococcus furiosus and mesophile Clostridium pasteurianum using the FIRST software. A global increase in structural rigidity (equivalently a decrease in flexibility) corresponds to an increase in thermostability. Locally, rigidity differences (between mesophilic and thermophilic structures) agree with differences in protection factors
IFACEwat: the interfacial water-implemented re-ranking algorithm to improve the discrimination of near native structures for protein rigid docking.

Science.gov (United States)

Su, Chinh; Nguyen, Thuy-Diem; Zheng, Jie; Kwoh, Chee-Keong

2014-01-01

Protein-protein docking is an in silico method to predict the formation of protein complexes. Due to limited computational resources, the protein-protein docking approach has been developed under the assumption of rigid docking, in which one of the two protein partners remains rigid during the protein associations and water contribution is ignored or implicitly presented. Despite obtaining a number of acceptable complex predictions, it seems to-date that most initial rigid docking algorithms still find it difficult or even fail to discriminate successfully the correct predictions from the other incorrect or false positive ones. To improve the rigid docking results, re-ranking is one of the effective methods that help re-locate the correct predictions in top high ranks, discriminating them from the other incorrect ones. Our results showed that the IFACEwat increased both the numbers of the near-native structures and improved their ranks as compared to the initial rigid docking ZDOCK3.0.2. In fact, the IFACEwat achieved a success rate of 83.8% for Antigen/Antibody complexes, which is 10% better than ZDOCK3.0.2. As compared to another re-ranking technique ZRANK, the IFACEwat obtains success rates of 92.3% (8% better) and 90% (5% better) respectively for medium and difficult cases. When comparing with the latest published re-ranking method F2Dock, the IFACEwat performed equivalently well or even better for several Antigen/Antibody complexes. With the inclusion of interfacial water, the IFACEwat improves mostly results of the initial rigid docking, especially for Antigen/Antibody complexes. The improvement is achieved by explicitly taking into account the contribution of water during the protein interactions, which was ignored or not fully presented by the initial rigid docking and other re-ranking techniques. In addition, the IFACEwat maintains sufficient computational efficiency of the initial docking algorithm, yet improves the ranks as well as the number of the near
49 CFR 587.18 - Dimensions of fixed rigid barrier.

Science.gov (United States)

2010-10-01

... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) DEFORMABLE BARRIERS Offset Deformable Barrier § 587.18 Dimensions of fixed rigid barrier. (a) The fixed rigid barrier has a mass of not... 49 Transportation 7 2010-10-01 2010-10-01 false Dimensions of fixed rigid barrier. 587.18 Section...
RIGIDITY, SENSITIVITY AND QUALITY OF ATTACHMENT - THE ROLE OF MATERNAL RIGIDITY IN THE EARLY SOCIOEMOTIONAL DEVELOPMENT OF PREMATURE-INFANTS

NARCIS (Netherlands)

BUTCHER, PR; KALVERBOER, A; MINDERAA, RB; VANDOORMAAL, EF; TENWOLDE, Y

1993-01-01

The associations between a mother's rigidity, her sensitivity in early (3 month) interaction and the quality of her premature infant's attachment at 13 months were investigated. Rigidity as a personality characteristic was not found to be significantly associated with sensitivity or quality of
Experimental observations of the coupling between induced currents and mechanical motion in torsionally supported square loops and plates. Part 2. Data inventory

International Nuclear Information System (INIS)

Weissenburger, D.W.; Bialek, J.M.; Cargulia, G.J.; Ulrickson, M.; Knott, M.J.; Turner, L.R.; Wehrle, R.B.

1984-12-01

A series of experiments was successfully conducted to investigate the coupling between induced currents and rigid body rotation in square loops and plates. The experiments were performed with the Fusion Electromagnetic Induction Experiment (FELIX) facility at the Argonne National Laboratory. The observed data exhibited the magnetic damping and magnetic stiffness effects ehich arise in coupled systems and agreed very well with previous analytic calculations
Cracking of open traffic rigid pavement

Directory of Open Access Journals (Sweden)

Niken Chatarina

2017-01-01

Full Text Available The research is done by observing the growth of real structure cracking in Natar, Lampung, Indonesia compared to C. Niken’s et al research and literature study. The rigid pavement was done with open traffic system. There are two main crack types on Natar rigid pavement: cracks cross the road, and cracks spreads on rigid pavement surface. The observation of cracks was analyzed by analyzing material, casting, curing, loading and shrinkage mechanism. The relationship between these analysis and shrinkage mechanism was studied in concrete micro structure. Open traffic make hydration process occur under vibration; therefore, fresh concrete was compressed and tensioned alternately since beginning. High temperature together with compression, cement dissociation, the growth of Ca2+ at very early age leads abnormal swelling. No prevention from outside water movement leads hydration process occur with limited water which caused spreads fine cracks. Limited water improves shrinkage and plastic phase becomes shorter; therefore, rigid pavement can’t accommodate the abnormal swelling and shrinking alternately and creates the spread of cracks. Discontinuing casting the concrete makes both mix under different condition, the first is shrink and the second is swell and creates weak line on the border; so, the cracks appear as cracks across the road.
Reversible Rigidity Control Using Low Melting Temperature Alloys

Science.gov (United States)

Shan, Wanliang; Lu, Tong; Majidi, Carmel

2013-03-01

Inspired by nature, materials able to achieve rapid rigidity changes have important applications for human body protection in military and many other areas. This talk presents the fabrication and design of soft-matter technologies that exhibit rapid reversible rigidity control. Fabricated with a masked deposition technique, the soft-matter composite contains liquid-phase and phase-changing metal alloys embedded in a soft and highly stretchable elastomer. The composite material can reversibly change its rigidity by three orders of magnitude and sustain large deformation.
Determination of Weight Suspension Rigidity in the Transport-Erector Aggregates

Directory of Open Access Journals (Sweden)

V. A. Zverev

2016-01-01

Full Text Available The aim is to determine weight suspension rigidity in aggregates designed to perform technological transport-erector operations at the miscellaneous launch complexes.We consider the weight suspension comprising the following distinctive structural components: the executive weight-lowering mechanism, polyspast mechanism, rope, traverse, and rods. A created structural dynamic model of suspension allowed us to define weight suspension rigidity. Within the framework of design analysis of a dynamic model we determined the rigidity of its structural units, i.e. traverse, rope, and polyspast.Known analytical relationships were used to calculate the rope rigidity. To determine rigidity of polyspast and traverse have been created special models based on the finite element method. For each model deformation in the specific points under the test load have been defined. Data obtained were used to determine trigidity of traverses and polyspast, and also rigidity of suspension in total. The rigidity models of polispast mechanism and traverse have been developed and calculated using the software complex "Zenit-95".As the research results, the paper presents a dynamic model of the weight suspension of the transport-erector aggregate, the finite element models of the polispast mechanism and traverse, an algorithm for determining the weight suspension rigidity and relevant analytical relationships.Independent calculation of weight suspension rigidity enables us to simplify further dynamic calculation of the aggregate-weight system because it allows attaining a simpler model of the aggregate-weight system that uses the weight suspension model as an element of equivalent rigidity. Despite this simplification the model allows us to determine correctly weight movement parameters and overloads in the aggregate-weight system in the process of technical operations.
Influence of flock coating on bending rigidity of woven fabrics

Science.gov (United States)

Ozdemir, O.; Kesimci, M. O.

2017-10-01

This work presents the preliminary results of our efforts that focused on the effect of the flock coating on the bending rigidity of woven fabrics. For this objective, a laboratory scale flocking unit is designed and flocked samples of controlled flock density are produced. Bending rigidity of the samples with different flock densities are measured on both flocked and unflocked sides. It is shown that the bending rigidity depends on both flock density and whether the side to be measured is flocked or not. Adhesive layer thickness on the bending rigidity is shown to be dramatic. And at higher basis weights, flock density gets less effective on bending rigidity.
Soft-matter composites with electrically tunable elastic rigidity

International Nuclear Information System (INIS)

Shan, Wanliang; Lu, Tong; Majidi, Carmel

2013-01-01

We use a phase-changing metal alloy to reversibly tune the elastic rigidity of an elastomer composite. The elastomer is embedded with a sheet of low-melting-point Field’s metal and an electric Joule heater composed of a serpentine channel of liquid-phase gallium–indium–tin (Galinstan ® ) alloy. At room temperature, the embedded Field’s metal is solid and the composite remains elastically rigid. Joule heating causes the Field’s metal to melt and allows the surrounding elastomer to freely stretch and bend. Using a tensile testing machine, we measure that the effective elastic modulus of the composite reversibly changes by four orders of magnitude when powered on and off. This dramatic change in rigidity is accurately predicted with a model for an elastic composite. Reversible rigidity control is also accomplished by replacing the Field’s metal with shape memory polymer. In addition to demonstrating electrically tunable rigidity with an elastomer, we also introduce a new technique to rapidly produce soft-matter electronics and multifunctional materials in several minutes with laser-patterned adhesive film and masked deposition of liquid-phase metal alloy. (paper)

Soft-matter composites with electrically tunable elastic rigidity

Science.gov (United States)

Shan, Wanliang; Lu, Tong; Majidi, Carmel

2013-08-01

We use a phase-changing metal alloy to reversibly tune the elastic rigidity of an elastomer composite. The elastomer is embedded with a sheet of low-melting-point Field’s metal and an electric Joule heater composed of a serpentine channel of liquid-phase gallium-indium-tin (Galinstan®) alloy. At room temperature, the embedded Field’s metal is solid and the composite remains elastically rigid. Joule heating causes the Field’s metal to melt and allows the surrounding elastomer to freely stretch and bend. Using a tensile testing machine, we measure that the effective elastic modulus of the composite reversibly changes by four orders of magnitude when powered on and off. This dramatic change in rigidity is accurately predicted with a model for an elastic composite. Reversible rigidity control is also accomplished by replacing the Field’s metal with shape memory polymer. In addition to demonstrating electrically tunable rigidity with an elastomer, we also introduce a new technique to rapidly produce soft-matter electronics and multifunctional materials in several minutes with laser-patterned adhesive film and masked deposition of liquid-phase metal alloy.
Rigid body motion in stereo 3D simulation

International Nuclear Information System (INIS)

Zabunov, Svetoslav

2010-01-01

This paper addresses the difficulties experienced by first-grade students studying rigid body motion at Sofia University. Most quantities describing the rigid body are in relations that the students find hard to visualize and understand. They also lose the notion of cause-result relations between vector quantities, such as the relation between torque and angular momentum. Consequently, the understanding of physical laws and conservation principles in free rigid body motion is hampered. This paper presents the capabilities of a 3D simulation, which aims to clarify these questions to the students, who are taught mechanics in the general physics course. The rigid body motion simulations may be observed at http://ialms.net/sim/, and are intended to complement traditional learning practices, not replace them, as the author shares the opinion that no simulation may fully resemble reality.
Vortex-Induced Vibrations of a Square Cylinder with Damped Free-End Conditions

Directory of Open Access Journals (Sweden)

S. Manzoor

2013-01-01

Full Text Available The authors report the results of vortex-induced vibrations of a square cylinder in a wind tunnel. This constitutes a high mass ratio environment. The square cylinder is mounted in the wind tunnel in such a fashion that it only performs rigid body oscillations perpendicular to the flow direction with damped free-end conditions. This physical situation allows a direct evaluation for analytical models relying on simplified 2D assumptions. The results are also compared with two-dimensional fluid-structure (CFD-CSD numerical simulations. The comparison shows that despite having one-dimensional motion, the analytical model does not predict the VIV region with correctness. Results show that the numerical simulations and experimental results differ from the analytical model for the prediction of reduced velocity corresponding to peak amplitude. Also the analytical reduced velocity envelope is underpredicted compared to both numerical simulations and experimental data despite the structure being lightly damped. The findings are significant as the experimental results for freely oscillating high mass ratio body show differences from the low mass ratio especially in the transition between VIV and galloping regions. However the numerical simulations show comparatively close agreement.
Does financial inclusion affect monetary policy in SAARC countries?

Directory of Open Access Journals (Sweden)

Sanjaya Kumar Lenka

2016-12-01

Full Text Available Alike the role of heart for human body, finance is the focal point of an economy, whereas savings and investment are its tubes and vessels. Hence, a solid financial system is a fundamental character of an enduring economy. The frozen financial system endures longer if its foundation is concrete and subsists in the people of grass-root level. They are those, who live in villages and small towns, earn meager income, work in primary sector, spend more on food, and have lesser social securities. In this setting, the process of bringing these people into the main stream of financial activities is called financial inclusion. This study describes the impact of financial inclusion on monetary policy of South Asian Association for Regional Cooperation (SAARC countries from 2004–2013. The study uses principal component analysis (PCA to construct a Financial Inclusion Index that serves as a proxy variable for the accessibility of financial inclusion in the SAARC countries. Adding to it, three different models like FEM, REM, and Panel-corrected standard errors are used for the analysis. In this study, an empirical result of generalized least square(GLS estimation shows that financial inclusion, exchange rate, and interest rate are negatively associated with inflation in SAARC countries.
Sensing of substratum rigidity and directional migration by fast-crawling cells

Science.gov (United States)

Okimura, Chika; Sakumura, Yuichi; Shimabukuro, Katsuya; Iwadate, Yoshiaki

2018-05-01

Living cells sense the mechanical properties of their surrounding environment and respond accordingly. Crawling cells detect the rigidity of their substratum and migrate in certain directions. They can be classified into two categories: slow-moving and fast-moving cell types. Slow-moving cell types, such as fibroblasts, smooth muscle cells, mesenchymal stem cells, etc., move toward rigid areas on the substratum in response to a rigidity gradient. However, there is not much information on rigidity sensing in fast-moving cell types whose size is ˜10 μ m and migration velocity is ˜10 μ m /min . In this study, we used both isotropic substrata with different rigidities and an anisotropic substratum that is rigid on the x axis but soft on the y axis to demonstrate rigidity sensing by fast-moving Dictyostelium cells and neutrophil-like differentiated HL-60 cells. Dictyostelium cells exerted larger traction forces on a more rigid isotropic substratum. Dictyostelium cells and HL-60 cells migrated in the "soft" direction on the anisotropic substratum, although myosin II-null Dictyostelium cells migrated in random directions, indicating that rigidity sensing of fast-moving cell types differs from that of slow types and is induced by a myosin II-related process.
Elastic Model Transitions Using Quadratic Inequality Constrained Least Squares

Science.gov (United States)

Orr, Jeb S.

2012-01-01

A technique is presented for initializing multiple discrete finite element model (FEM) mode sets for certain types of flight dynamics formulations that rely on superposition of orthogonal modes for modeling the elastic response. Such approaches are commonly used for modeling launch vehicle dynamics, and challenges arise due to the rapidly time-varying nature of the rigid-body and elastic characteristics. By way of an energy argument, a quadratic inequality constrained least squares (LSQI) algorithm is employed to e ect a smooth transition from one set of FEM eigenvectors to another with no requirement that the models be of similar dimension or that the eigenvectors be correlated in any particular way. The physically unrealistic and controversial method of eigenvector interpolation is completely avoided, and the discrete solution approximates that of the continuously varying system. The real-time computational burden is shown to be negligible due to convenient features of the solution method. Simulation results are presented, and applications to staging and other discontinuous mass changes are discussed
Rigid body formulation in a finite element context with contact interaction

Science.gov (United States)

Refachinho de Campos, Paulo R.; Gay Neto, Alfredo

2018-03-01

The present work proposes a formulation to employ rigid bodies together with flexible bodies in the context of a nonlinear finite element solver, with contact interactions. Inertial contributions due to distribution of mass of a rigid body are fully developed, considering a general pole position associated with a single node, representing a rigid body element. Additionally, a mechanical constraint is proposed to connect a rigid region composed by several nodes, which is useful for linking rigid/flexible bodies in a finite element environment. Rodrigues rotation parameters are used to describe finite rotations, by an updated Lagrangian description. In addition, the contact formulation entitled master-surface to master-surface is employed in conjunction with the rigid body element and flexible bodies, aiming to consider their interaction in a rigid-flexible multibody environment. New surface parameterizations are presented to establish contact pairs, permitting pointwise interaction in a frictional scenario. Numerical examples are provided to show robustness and applicability of the methods.
Rigid-Plastic Post-Buckling Analysis of Columns and Quadratic Plates

DEFF Research Database (Denmark)

Jönsson, Jeppe

2008-01-01

the compressive load as a function of the transverse displacement. An estimate of the magnitude of the transverse displacement prior to the forming of the collapse mechanism is introduced into the compressive load function, determined by the virtual work equation, thereby revealing a qualified estimate...... yield lines accommodate differential rotations of rigid parts and the area “collapse” yield lines accommodate local area changes of the rigid parts thereby preserving compatibility of the rigid parts of a plate. The approach will be illustrated for rigid plastic column analysis and for a quadratic plate...
Trajectory Correction and Locomotion Analysis of a Hexapod Walking Robot with Semi-Round Rigid Feet

Science.gov (United States)

Zhu, Yaguang; Jin, Bo; Wu, Yongsheng; Guo, Tong; Zhao, Xiangmo

2016-01-01

Aimed at solving the misplaced body trajectory problem caused by the rolling of semi-round rigid feet when a robot is walking, a legged kinematic trajectory correction methodology based on the Least Squares Support Vector Machine (LS-SVM) is proposed. The concept of ideal foothold is put forward for the three-dimensional kinematic model modification of a robot leg, and the deviation value between the ideal foothold and real foothold is analyzed. The forward/inverse kinematic solutions between the ideal foothold and joint angular vectors are formulated and the problem of direct/inverse kinematic nonlinear mapping is solved by using the LS-SVM. Compared with the previous approximation method, this correction methodology has better accuracy and faster calculation speed with regards to inverse kinematics solutions. Experiments on a leg platform and a hexapod walking robot are conducted with multi-sensors for the analysis of foot tip trajectory, base joint vibration, contact force impact, direction deviation, and power consumption, respectively. The comparative analysis shows that the trajectory correction methodology can effectively correct the joint trajectory, thus eliminating the contact force influence of semi-round rigid feet, significantly improving the locomotion of the walking robot and reducing the total power consumption of the system. PMID:27589766
About deformation and rigidity in relativity

International Nuclear Information System (INIS)

Coll, Bartolome

2007-01-01

The notion of deformation involves that of rigidity. In relativity, starting from Born's early definition of rigidity, some other ones have been proposed, offering more or less interesting aspects but also accompanied of undesired or even pathological properties. In order to clarify the origin of these difficulties presented by the notion of rigidity in relativity, we analyze with some detail significant aspects of the unambiguous classical, Newtonian, notion. In particular, the relative character of its kinetic definition is pointed out, allowing to predict and to understand the limitations imposed by Herglotz-Noether theorem. Also, its equivalent dynamic definition is obtained and, in contrast, its absolute character is shown. But in spite of this absolute character, the dynamic definition is shown to be not extensible to relativity. The metric deformation of Minkowski space by the presence of a gravitational field is interpreted as a universal deformation, and it is shown that, under natural conditions, only a simple deformation law is possible, relating locally, but in an one-to-one way, gravitational fields and gauge classes of two-forms. We argue that fields of unit vectors associated to the internal gauge class of two-forms of every space-time (and, in particular, of Minkowski space-time) are the relativistic analogues of the classical accelerated observers, i.e. of the classical rigid motions. Some other consequences of the universal law of gravitational deformation are commented
Genus Ranges of 4-Regular Rigid Vertex Graphs.

Science.gov (United States)

Buck, Dorothy; Dolzhenko, Egor; Jonoska, Nataša; Saito, Masahico; Valencia, Karin

2015-01-01

A rigid vertex of a graph is one that has a prescribed cyclic order of its incident edges. We study orientable genus ranges of 4-regular rigid vertex graphs. The (orientable) genus range is a set of genera values over all orientable surfaces into which a graph is embedded cellularly, and the embeddings of rigid vertex graphs are required to preserve the prescribed cyclic order of incident edges at every vertex. The genus ranges of 4-regular rigid vertex graphs are sets of consecutive integers, and we address two questions: which intervals of integers appear as genus ranges of such graphs, and what types of graphs realize a given genus range. For graphs with 2 n vertices ( n > 1), we prove that all intervals [ a, b ] for all a genus ranges. For graphs with 2 n - 1 vertices ( n ≥ 1), we prove that all intervals [ a, b ] for all a genus ranges. We also provide constructions of graphs that realize these ranges.
Dual Quaternion Variational Integrator for Rigid Body Dynamic Simulation

OpenAIRE

Xu, Jiafeng; Halse, Karl Henning

2016-01-01

In rigid body dynamic simulations, often the algorithm is required to deal with general situations where both reference point and inertia matrix are arbitrarily de- fined. We introduce a novel Lie group variational integrator using dual quaternion for simulating rigid body dynamics in all six degrees of freedom. Dual quaternion is used to represent rigid body kinematics and one-step Lie group method is used to derive dynamic equations. The combination of these two becomes the first Lie group ...
Motions of deformable inclusions in a horizontally oscillating vessel with a compressible fluid

DEFF Research Database (Denmark)

Demidov, I.V.; Sorokin, Vladislav

2016-01-01

The paper is concerned with the analysis of rigid particle and compressible gas bubble motion in a horizontally oscillating vessel with a compressible fluid. A nonlinear differential equation describing motion of inclusions with respect to the vessel is derived and solved by the method of direct...... of the bubbles which are affected by the negligible vibrational force is found. Also an approximate expression has been obtained for the average velocity of bubble׳s motion in the fluid; relationship between this velocity and bubble radius and vibration parameters has been revealed. A simple physical explanation...
The Almost Periodic Rigidity of Crystallographic Bar-Joint Frameworks

Directory of Open Access Journals (Sweden)

Ghada Badri

2014-04-01

Full Text Available A crystallographic bar-joint framework, C in Rd, is shown to be almost periodically infinitesimally rigid if and only if it is strictly periodically infinitesimally rigid and the rigid unit mode (RUM spectrum, Ω (C, is a singleton. Moreover, the almost periodic infinitesimal flexes of C are characterised in terms of a matrix-valued function, ΦC(z, on the d-torus, Td, determined by a full rank translation symmetry group and an associated motif of joints and bars.
Wobbling motion: A γ-rigid or γ-soft mode?

International Nuclear Information System (INIS)

Casten, R.F.; McCutchan, E.A.; Beausang, C.W.; Zamfir, N.V.; Zhang Jingye

2003-01-01

For even-even nuclei, it is shown that the predicted B(E2) values from the odd spin states of the quasi-γ band in a γ-soft nucleus to the yrast band are quite similar to those predicted for the one-phonon wobbling mode of a rigidly triaxial nucleus. This suggests that the observation of wobbling points to axial asymmetry, but not necessarily to rigid triaxiality. However, another observable that does distinguish γ-soft from γ-rigid structure is identified
Torsion of a Cosserat elastic bar with square cross section: theory and experiment

Science.gov (United States)

Drugan, W. J.; Lakes, R. S.

2018-04-01

An approximate analytical solution for the displacement and microrotation vector fields is derived for pure torsion of a prismatic bar with square cross section comprised of homogeneous, isotropic linear Cosserat elastic material. This is accomplished by analytical simplification coupled with use of the principle of minimum potential energy together with polynomial representations for the desired field components. Explicit approximate expressions are derived for cross section warp and for applied torque versus angle of twist of the bar. These show that torsional rigidity exceeds the classical elasticity value, the difference being larger for slender bars, and that cross section warp is less than the classical amount. Experimental measurements on two sets of 3D printed square cross section polymeric bars, each set having a different microstructure and four different cross section sizes, revealed size effects not captured by classical elasticity but consistent with the present analysis for physically sensible values of the Cosserat moduli. The warp can allow inference of Cosserat elastic constants independently of any sensitivity the material may have to dilatation gradients; warp also facilitates inference of Cosserat constants that are difficult to obtain via size effects.
Rigid Spine Syndrome among Children in Oman

Directory of Open Access Journals (Sweden)

Roshan Koul

2015-08-01

Full Text Available Objectives: Rigidity of the spine is common in adults but is rarely observed in children. The aim of this study was to report on rigid spine syndrome (RSS among children in Oman. Methods: Data on children diagnosed with RSS were collected consecutively at presentation between 1996 and 2014 at the Sultan Qaboos University Hospital (SQUH in Muscat, Oman. A diagnosis of RSS was based on the patient’s history, clinical examination, biochemical investigations, electrophysiological findings, neuro-imaging and muscle biopsy. Atrophy of the paraspinal muscles, particularly the erector spinae, was the diagnostic feature; this was noted using magnetic resonance imaging of the spine. Children with disease onset in the paraspinal muscles were labelled as having primary RSS or rigid spinal muscular dystrophy. Secondary RSS was classified as RSS due to the late involvement of other muscle diseases. Results: Over the 18-year period, 12 children were included in the study, with a maleto- female ratio of 9:3. A total of 10 children were found to have primary RSS or rigid spinal muscular dystrophy syndrome while two had secondary RSS. Onset of the disease ranged from birth to 18 months of age. A family history was noted, with two siblings from one family and three siblings from another (n = 5. On examination, children with primary RSS had typical features of severe spine rigidity at onset, with the rest of the neurological examination being normal. Conclusion: RSS is a rare disease with only 12 reported cases found at SQUH during the study period. Cases of primary RSS should be differentiated from the secondary type.
Measurement of two-particle semi-inclusive rapidity distributions at the CERN ISR

CERN Document Server

Amendolia, S R; Bosisio, L; Braccini, Pier Luigi; Bradaschia, C; Castaldi, R; Cavasinni, V; Cerri, C; Del Prete, T; Finocchiaro, G; Foà, L; Giromini, P; Grannis, P; Green, D; Jöstlein, H; Kephart, R; Laurelli, P; Menzione, A; Ristori, L; Sanguinetti, G; Thun, R; Valdata, M

1976-01-01

Data are presented on the semi-inclusive distributions of rapidities of secondary particles produced in pp collisions at very high energies. The experiment was performed at the CERN Intersecting Storage Rings (ISR). The data given, at centre-of-mass energies of square root s=23 and 62 GeV, include the single-particle distributions and two-particle correlations. The semi-inclusive correlations show pronounced short-range correlation effects which have a width considerably narrower than in the case of inclusive correlations. It is shown that these short-range effects can be understood empirically in terms of three parameters whose energy and multiplicity dependence are studied. The data support the picture of multiparticle production in which clusters of small multiplicity and small dispersion are emitted with subsequent decay into hadrons. (32 refs).
Monte Carlo simulations of increased/decreased scattering inclusions inside a turbid slab

International Nuclear Information System (INIS)

Dagdug, Leonardo; Chernomordik, Victor; Weiss, George H; Gandjbakhche, Amir H

2005-01-01

We analyse the effect on scattered photons of anomalous optical inclusions in a turbid slab with otherwise uniform properties. Our motivation for doing so is that inclusions affect scattering contrast used to quantify optical properties found from transmitted light intensity measured in transillumination experiments. The analysis is based on a lattice random walk formalism which takes into account effects of both positive and negative deviations of the scattering coefficient from that of the bulk. Our simulations indicate the existence of a qualitative difference between the effects of these two types of perturbations. In the case of positive perturbations the time delay is found to be proportional to the square of the size of the inclusion while for negative perturbations the time delay is a linear function of its volume
Quantum mechanics of a generalised rigid body

International Nuclear Information System (INIS)

Gripaios, Ben; Sutherland, Dave

2016-01-01

We consider the quantum version of Arnold’s generalisation of a rigid body in classical mechanics. Thus, we quantise the motion on an arbitrary Lie group manifold of a particle whose classical trajectories correspond to the geodesics of any one-sided-invariant metric. We show how the derivation of the spectrum of energy eigenstates can be simplified by making use of automorphisms of the Lie algebra and (for groups of type I) by methods of harmonic analysis. We show how the method can be extended to cosets, generalising the linear rigid rotor. As examples, we consider all connected and simply connected Lie groups up to dimension 3. This includes the universal cover of the archetypical rigid body, along with a number of new exactly solvable models. We also discuss a possible application to the topical problem of quantising a perfect fluid. (paper)

Customizable rigid head fixation for infants: technical note.

Science.gov (United States)

Udayakumaran, Suhas; Onyia, Chiazor U

2016-01-01

The need and advantages of rigid fixation of the head in cranial surgeries are well documented (Berryhill et al., Otolaryngol Head Neck Surg 121:269-273, 1999). Head fixation for neurosurgical procedures in infants and in early years has been a challenge and is fraught with risk. Despite the fact that pediatric pins are designed, rigid head fixation involving direct application of pins to the head of infants and slightly older children is still generally not safe (Agrawal and Steinbok, Childs Nerv Syst 22:1473-1474, 2006). Yet, there are some surgeries in which some form of rigid fixation is required (Agrawal and Steinbok, Childs Nerv Syst 22:1473-1474, 2006). We describe a simple technique to achieve rigid fixation of the head in infants for neurosurgical procedures. This involves applying a head band made of Plaster of Paris (POP) around the head and then applying the fixation pins of the fixation frame directly on to the POP. We have used this technique of head fixation successfully for infants with no complications.
"Mind the trap": mindfulness practice reduces cognitive rigidity.

Directory of Open Access Journals (Sweden)

Jonathan Greenberg

Full Text Available Two experiments examined the relation between mindfulness practice and cognitive rigidity by using a variation of the Einstellung water jar task. Participants were required to use three hypothetical jars to obtain a specific amount of water. Initial problems were solvable by the same complex formula, but in later problems ("critical" or "trap" problems solving was possible by an additional much simpler formula. A rigidity score was compiled through perseverance of the complex formula. In Experiment 1, experienced mindfulness meditators received significantly lower rigidity scores than non-meditators who had registered for their first meditation retreat. Similar results were obtained in randomized controlled Experiment 2 comparing non-meditators who underwent an eight meeting mindfulness program with a waiting list group. The authors conclude that mindfulness meditation reduces cognitive rigidity via the tendency to be "blinded" by experience. Results are discussed in light of the benefits of mindfulness practice regarding a reduced tendency to overlook novel and adaptive ways of responding due to past experience, both in and out of the clinical setting.
Rigidity of outermost MOTS: the initial data version

Science.gov (United States)

Galloway, Gregory J.

2018-03-01

In the paper Commun Anal Geom 16(1):217-229, 2008, a rigidity result was obtained for outermost marginally outer trapped surfaces (MOTSs) that do not admit metrics of positive scalar curvature. This allowed one to treat the "borderline case" in the author's work with R. Schoen concerning the topology of higher dimensional black holes (Commun Math Phys 266(2):571-576, 2006). The proof of this rigidity result involved bending the initial data manifold in the vicinity of the MOTS within the ambient spacetime. In this note we show how to circumvent this step, and thereby obtain a pure initial data version of this rigidity result and its consequence concerning the topology of black holes.
APPLICATION OF RIGID LINKS IN STRUCTURAL DESIGN MODELS

Directory of Open Access Journals (Sweden)

Sergey Yu. Fialko

2017-09-01

Full Text Available A special finite element modelling rigid links is proposed for the linear static and buckling analysis. Unlike the classical approach based on the theorems of rigid body kinematics, the proposed approach preserves the similarity between the adjacency graph for a sparse matrix and the adjacency graph for nodes of the finite element model, which allows applying sparse direct solvers more effectively. Besides, the proposed approach allows significantly reducing the number of nonzero entries in the factored stiffness matrix in comparison with the classical one, which greatly reduces the duration of the solution. For buckling problems of structures containing rigid bodies, this approach gives correct results. Several examples demonstrate its efficiency.
High frequency permeameter with semi-rigid pick-up coil

International Nuclear Information System (INIS)

Shin, Sung-Yong; Shin, Kwang-Ho . E-mail : khshin@star.ks.ac.kr; Kim, Jong-sung; Kim, Young-Hak; Lim, Sang-Ho; Sa-gong, Geon

2006-01-01

In this study, we propose the application of semi-rigid cable loop as a single turn shielded loop pick-up coil for the high frequency permeameter. Since the semi-rigid cable pick-up coil has simple structure, it is very easy to make the pick-up coil with bending and conventional soldering. The permeability of cobalt base amorphous ribbon was investigated using the developed permeameter for demonstrating its performance. The permeability of the amorphous ribbon was driven from the S-parameters measured using a network analyzer and permameter having the semi-rigid pick-up coil
Durable bistable auxetics made of rigid solids

Science.gov (United States)

Shang, Xiao; Liu, Lu; Rafsanjani, Ahmad; Pasini, Damiano

2018-02-01

Bistable Auxetic Metamaterials (BAMs) are a class of monolithic perforated periodic structures with negative Poisson's ratio. Under tension, a BAM can expand and reach a second state of equilibrium through a globally large shape transformation that is ensured by the flexibility of its elastomeric base material. However, if made from a rigid polymer, or metal, BAM ceases to function due to the inevitable rupture of its ligaments. The goal of this work is to extend the unique functionality of the original kirigami architecture of BAM to a rigid solid base material. We use experiments and numerical simulations to assess performance, bistability and durability of rigid BAMs at 10,000 cycles. Geometric maps are presented to elucidate the role of the main descriptors of BAM architecture. The proposed design enables the realization of BAM from a large palette of materials, including elastic-perfectly plastic materials and potentially brittle materials.
Utility of semi-rigid thoracoscopy in undiagnosed exudative pleural effusion.

Science.gov (United States)

Nattusamy, Loganathan; Madan, Karan; Mohan, Anant; Hadda, Vijay; Jain, Deepali; Madan, Neha Kawatra; Arava, Sudheer; Khilnani, Gopi C; Guleria, Randeep

2015-01-01

Semi-rigid thoracoscopy is a safe and efficacious procedure in patients with undiagnosed pleural effusion. Literature on its utility from developing countries is limited. We herein describe our initial experience on the utility of semi-rigid thoracoscopy from a tertiary care teaching and referral center in north India. We also perform a systematic review of studies reporting the utility of semi-rigid thoracoscopy from India. The primary objective was to evaluate the diagnostic utility of semi-rigid thoracoscopy in patients with undiagnosed exudative pleural effusion. Semi-rigid thoracoscopy was performed under local anesthesia and conscious sedation in the bronchoscopy suite. A total of 48 patients underwent semi-rigid thoracoscopy between August 2012 and December 2013 for undiagnosed pleural effusion. Mean age was 50.9 ± 14.1 years (range: 17-78 years). Pre-procedure clinico-radiological diagnoses were malignant pleural effusion [36 patients (75%)], tuberculosis (TB) [10 (20.83%) patients], and empyema [2 patients (4.17%)]. Patients with empyema underwent the procedure for pleural biopsy, optimal placement of intercostal tube and adhesiolysis. Thoracoscopic pleural biopsy diagnosed pleural malignancy in 30 (62.5%) patients and TB in 2 (4.17%) patients. Fourteen (29.17%) patients were diagnosed with non-specific pleuritis and normal pleura was diagnosed on a pleural biopsy in 2 (4.17%) patients. Overall, a definitive diagnosis of either pleural malignancy or TB was obtained in 32 (66.7%) patients. Combined overall sensitivity, specificity, positive predictive value and negative predictive value of thoracoscopic pleural biopsy for malignant pleural effusion were 96.77%, 100%, 100% and 66.67%, respectively. There was no procedure-related mortality. On performing a systematic review of literature, four studies on semi-rigid thoracoscopy from India were identified. Semi-rigid thoracoscopy is a safe and efficacious procedure in patients with undiagnosed exudative
Algebraic Methods for Counting Euclidean Embeddings of Rigid Graphs

NARCIS (Netherlands)

I.Z. Emiris; E.P. Tsigaridas; A. Varvitsiotis (Antonios); E.R. Gasner

2009-01-01

textabstract The study of (minimally) rigid graphs is motivated by numerous applications, mostly in robotics and bioinformatics. A major open problem concerns the number of embeddings of such graphs, up to rigid motions, in Euclidean space. We capture embeddability by polynomial systems
Rigid body dynamics of mechanisms

CERN Document Server

Hahn, Hubert

2003-01-01

The second volume of Rigid Body Dynamics of Mechanisms covers applications via a systematic method for deriving model equations of planar and spatial mechanisms. The necessary theoretical foundations have been laid in the first volume that introduces the theoretical mechanical aspects of mechatronic systems. Here the focus is on the application of the modeling methodology to various examples of rigid-body mechanisms, simple planar ones as well as more challenging spatial problems. A rich variety of joint models, active constraints, plus active and passive force elements is treated. The book is intended for self-study by working engineers and students concerned with the control of mechanical systems, i.e. robotics, mechatronics, vehicles, and machine tools. The examples included are a likely source from which to choose models for university lectures.
On Inclusion-Matrix Interfacial Stresses in Composites Containing Phase-Transforming Phases

International Nuclear Information System (INIS)

Wang, Y.-C.; Ko, C.-C.

2010-01-01

Recent development in composites containing phase-transforming particles, such as vanadium dioxide or barium titanate, reveals the overall stiffness and viscoelastic damping of the composites may be unbounded. Negative stiffness is induced from phase transformation predicted by the Landau phase transformation theory. Although this unbounded phenomenon is theoretically supported with the composite homogenization theory, detailed stress analyses of the composites are still lacking. In this work, we analyze the two-dimensional plane stress elasticity problem of a square plate containing a circular inclusion, under the assumption that the Young's modulus of the inclusion is negative. Assumption of negative stiffness is a priori in the present analysis. A static loading condition is adopted to estimate the effective modulus of the composites by the ratio of applied stress to averaged strain on the loading edges. It is found that the interfacial stresses between the circular inclusion and matrix increase dramatically when the negative stiffness is so tuned that overall stiffness is unbounded. Furthermore, it is found that stress distributions in the inclusion are not uniform, contrary to Eshelby's theorem, which states, for two-phase, infinite composites, the inclusion's stress distribution is uniform when the shape of the inclusion has higher symmetry than an ellipse. The rationale for this nonuniform stress distributions is due to nonlocal effects induced from negative stiffness.
Associative memory through rigid origami

Science.gov (United States)

Murugan, Arvind; Brenner, Michael

2015-03-01

Mechanisms such as Miura Ori have proven useful in diverse contexts since they have only one degree of freedom that is easily controlled. We combine the theory of rigid origami and associative memory in frustrated neural networks to create structures that can ``learn'' multiple generic folding mechanisms and yet can be robustly controlled. We show that such rigid origami structures can ``recall'' a specific learned mechanism when induced by a physical impulse that only need resemble the desired mechanism (i.e. robust recall through association). Such associative memory in matter, seen before in self-assembly, arises due to a balance between local promiscuity (i.e., many local degrees of freedom) and global frustration which minimizes interference between different learned behaviors. Origami with associative memory can lead to a new class of deployable structures and kinetic architectures with multiple context-dependent behaviors.
Functionally rigid bistable [2]rotaxanes

DEFF Research Database (Denmark)

Nygaard, Sune; Leung, Ken C-F; Aprahamian, Ivan

2007-01-01

defines an unambiguous distance of 1.5 nm over which the ring moves between the MPTTF and NP units. The degenerate NP/NP [2]rotaxane was used to investigate the shuttling barrier by dynamic 1H NMR spectroscopy for the movement of the CBPQT4+ ring across the new rigid spacer. It is evident from...... better control over the position of the ring component in the ground state but also for control over the location of the CBPQT4+ ring during solution-state switching experiments, triggered either chemically (1H NMR) or electrochemically (cyclic voltammetry). In this instance, the use of the rigid spacer......Two-station [2]rotaxanes in the shape of a degenerate naphthalene (NP) shuttle and a nondegenerate monopyrrolotetrathiafulvalene (MPTTF)/NP redox-controllable switch have been synthesized and characterized in solution. Their dumbbell-shaped components are composed of polyether chains interrupted...
Rigid external maxillary distraction and rhinoplasty for pyknodysostosis.

Science.gov (United States)

Varol, Altan; Sabuncuoglu, Fidan Alakus; Sencimen, Metin; Akcam, Timur; Olmez, Hüseyin; Basa, Selçuk

2011-05-01

This article reports the treatment of an 33-year-old female patient with pyknodysostosis by rigid external distraction II midface distraction system. The patient with pyknodysostosis described in this report had severe midfacial hypoplasia. Correction of this by use of routine orthognathic surgery would require osteosynthesis and bone grafting. Risk of infection and/or nonunion after such a surgical procedure was considered too great, and therefore the possibility of treatment by distraction osteogenesis of the maxilla was evaluated. The rigid external distraction II midface distraction system was used to relocate the hypoplastic maxilla at anterior-inferior projection. Distraction osteogenesis should be considered as the primary reconstructive method for maxillofacial deformities in patients with sclerosing bone dysplasias, since this is the second reported case treated successfully with rigid external distraction.
The diagnostic role of thoracoscope in undiagnosed pleural effusion: Rigid versus flexible

Directory of Open Access Journals (Sweden)

Mostafa Mahmoud Abdel Mageid Shaheen

2014-07-01

Conclusions: Thoracoscopy using either fibreoptic bronchoscope or rigid thoracoscope is safe and well tolerated. Rigid thoracoscope has a higher diagnostic yield, easier handling, better orientation and is less expensive. Nevertheless, fibreoptic bronchoscope is an alternative technique if rigid thoracoscopy is not available.
Social inclusion and inclusive education

Directory of Open Access Journals (Sweden)

Marsela Robo

2014-07-01

In line with global debate on social inclusion and exclusion, the author brings the way this debate has now pervaded both the official and development policy discourse in Albania.Social inclusion is considered as one of the priorities of the current government, with poverty reduction as its main focus, which will be ensured not only through economic development. In the end, the article focuses on the role of education as a very important and useful tool for ensuring social inclusion.Social inclusion through education, in particular through vocational education, considered by the author as the only way towards sustainable development of Albanian society.
Rigid origami vertices: conditions and forcing sets

Directory of Open Access Journals (Sweden)

Zachary Abel

2016-04-01

Full Text Available We develop an intrinsic necessary and sufficient condition for single-vertex origami crease patterns to be able to fold rigidly. We classify such patterns in the case where the creases are pre-assigned to be mountains and valleys as well as in the unassigned case. We also illustrate the utility of this result by applying it to the new concept of minimal forcing sets for rigid origami models, which are the smallest collection of creases that, when folded, will force all the other creases to fold in a prescribed way.
Type number and rigidity of fibred surfaces

International Nuclear Information System (INIS)

Markov, P E

2001-01-01

Infinitesimal l-th order bendings, 1≤l≤∞, of higher-dimensional surfaces are considered in higher-dimensional flat spaces (for l=∞ an infinitesimal bending is assumed to be an analytic bending). In terms of the Allendoerfer type number, criteria are established for the (r,l)-rigidity (in the terminology of Sabitov) of such surfaces. In particular, an (r,l)-infinitesimal analogue is proved of the classical theorem of Allendoerfer on the unbendability of surfaces with type number ≥3 and the class of (r,l)-rigid fibred surfaces is distinguished
Evaluating a method for automated rigid registration

DEFF Research Database (Denmark)

Darkner, Sune; Vester-Christensen, Martin; Larsen, Rasmus

2007-01-01

to point distance. T-test for common mean are used to determine the performance of the two methods (supported by a Wilcoxon signed rank test). The performance influence of sampling density, sampling quantity, and norms is analyzed using a similar method.......We evaluate a novel method for fully automated rigid registration of 2D manifolds in 3D space based on distance maps, the Gibbs sampler and Iterated Conditional Modes (ICM). The method is tested against the ICP considered as the gold standard for automated rigid registration. Furthermore...
Two Phase Non-Rigid Multi-Modal Image Registration Using Weber Local Descriptor-Based Similarity Metrics and Normalized Mutual Information

Directory of Open Access Journals (Sweden)

Feng Yang

2013-06-01

Full Text Available Non-rigid multi-modal image registration plays an important role in medical image processing and analysis. Existing image registration methods based on similarity metrics such as mutual information (MI and sum of squared differences (SSD cannot achieve either high registration accuracy or high registration efficiency. To address this problem, we propose a novel two phase non-rigid multi-modal image registration method by combining Weber local descriptor (WLD based similarity metrics with the normalized mutual information (NMI using the diffeomorphic free-form deformation (FFD model. The first phase aims at recovering the large deformation component using the WLD based non-local SSD (wldNSSD or weighted structural similarity (wldWSSIM. Based on the output of the former phase, the second phase is focused on getting accurate transformation parameters related to the small deformation using the NMI. Extensive experiments on T1, T2 and PD weighted MR images demonstrate that the proposed wldNSSD-NMI or wldWSSIM-NMI method outperforms the registration methods based on the NMI, the conditional mutual information (CMI, the SSD on entropy images (ESSD and the ESSD-NMI in terms of registration accuracy and computation efficiency.
Shape fabric development in rigid clast populations under pure shear: The influence of no-slip versus slip boundary conditions

Science.gov (United States)

Mulchrone, Kieran F.; Meere, Patrick A.

2015-09-01

Shape fabrics of elliptical objects in rocks are usually assumed to develop by passive behavior of inclusions with respect to the surrounding material leading to shape-based strain analysis methods belonging to the Rf/ϕ family. A probability density function is derived for the orientational characteristics of populations of rigid ellipses deforming in a pure shear 2D deformation with both no-slip and slip boundary conditions. Using maximum likelihood a numerical method is developed for estimating finite strain in natural populations deforming for both mechanisms. Application to a natural example indicates the importance of the slip mechanism in explaining clast shape fabrics in deformed sediments.

Lateral rigidity of cracked concrete structures

International Nuclear Information System (INIS)

Castellani, A.; Chesi, C.

1979-01-01

Numerical results are discussed on the lateral rigidity of reinforced concrete structures with a given crack distribution. They have been favourably checked with experimental results for cylindrical shells under the effect of a thermal gradient producing vertical cracking or vertical plus horizontal cracking. The main effects characterizing the concrete behaviour are: (1) The shear transfer across a crack; (2) The shear transfer degradation after cyclic loading; (3) The tension stiffening provided by the concrete between crack and crack, in the normal stress transfer; (4) The temperature effect on the elastic moduli of concrete, when cracks are of thermal origin. Only the 1st effect is discussed on an experimental basis. Two broad cathegories of reinforced concrete structures have been investigated in this respect: shear walls of buildings and cylindrical containment structures. The main conclusions so far reached are: (1) Vertical cracks are unlikely to decrease the lateral rigidity to less than 80% of the original one, and to less than 90% when they do not involve the entire thickness of the wall; (2) The appearence of horizontal cracks can reduce the lateral rigidity by some 30% or more; (3) A noticeable but not yet evaluated influence is shown by cyclic loading. (orig.)
Connections rigidity effect on probability of fracture in steel moment frames

Directory of Open Access Journals (Sweden)

Gholamreza Abdollahzadeh

2017-08-01

Full Text Available Connections in steel moment frames are idealized in full pinned and full rigid conditions. Because with this assumption, in spite of real behavior of connection, real story drifts are less anticipated and maybe frame is designed without performance of bracing. There are several methods for modeling actual behavior of semi rigid connections. In this method a connection with certain rigidity is modeled by a rotational spring with corresponding stiffness. This stiffness is achieved by certain formula. In other words, each percent of rigidity corresponds to one rotational spring stiffness. In this research in order to evaluate the real behavior of connection in analysis and designing process and fracture probability one frame including four stories and one bay with three types of connection has been modeled and designed in ETABS. Each model has an individual rigidity which is equal to 10, 75 and 90 percent. With respect to maximum drift and different PGA in roof, probabilities of low, medium, high and complete fracture were calculated. For this purpose, with applying different PGA to modeled frames, amounts of drift in the roof are achieved. Then these values are compared with given values in American code. Finally, investigation showed that when rigidity in frame connections increases, the probability of frame fracture decreases. In other words, fully rigid assumption of connection in analysis process leads to decreasing in real probability of fracture in frames which is a noticeable risk in building designing processes.
Rigid-plastic seismic design of reinforced concrete structures

DEFF Research Database (Denmark)

Costa, Joao Domingues; Bento, R.; Levtchitch, V.

2007-01-01

structural strength with respect to a pre-defined performance parameter using a rigid-plastic response spectrum, which is characteristic of the ground motion alone. The maximum strength demand at any point is solely dependent on the intensity of the ground motion, which facilitates the task of distributing......In this paper a new seismic design procedure for Reinforced Concrete (R/C) structures is proposed-the Rigid-Plastic Seismic Design (RPSD) method. This is a design procedure based on Non-Linear Time-History Analysis (NLTHA) for systems expected to perform in the non-linear range during a lifetime...... earthquake event. The theoretical background is the Theory of Plasticity (Rigid-Plastic Structures). Firstly, a collapse mechanism is chosen and the corresponding stress field is made safe outside the regions where plastic behaviour takes place. It is shown that this allows the determination of the required...
Unified Creep Plasticity Damage (UCPD) Model for Rigid Polyurethane Foams.

Energy Technology Data Exchange (ETDEWEB)

Neilsen, Michael K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lu, Wei-Yang [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Scherzinger, William M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hinnerichs, Terry D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lo, Chi S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-06-01

Numerous experiments were performed to characterize the mechanical response of several different rigid polyurethane foams (FR3712, PMDI10, PMDI20, and TufFoam35) to large deformation. In these experiments, the effects of load path, loading rate, and temperature were investigated. Results from these experiments indicated that rigid polyurethane foams exhibit significant volumetric and deviatoric plasticity when they are compressed. Rigid polyurethane foams were also found to be very strain-rate and temperature dependent. These foams are also rather brittle and crack when loaded to small strains in tension or to larger strains in compression. Thus, a new Unified Creep Plasticity Damage (UCPD) model was developed and implemented into SIERRA with the name Foam Damage to describe the mechanical response of these foams to large deformation at a variety of temperatures and strain rates. This report includes a description of recent experiments and experimental findings. Next, development of a UCPD model for rigid, polyurethane foams is described. Selection of material parameters for a variety of rigid polyurethane foams is then discussed and finite element simulations with the new UCPD model are compared with experimental results to show behavior that can be captured with this model.
Elasticity of Relativistic Rigid Bodies?

Science.gov (United States)

Smarandache, Florentin

2013-10-01

In the classical Twin Paradox, according to the Special Theory of Relativity, when the traveling twin blasts off from the Earth to a relative velocity v =√{/3 } 2 c with respect to the Earth, his measuring stick and other physical objects in the direction of relative motion shrink to half their lengths. How is that possible in the real physical world to have let's say a rigid rocket shrinking to half and then later elongated back to normal as an elastic material when it stops? What is the explanation for the traveler's measuring stick and other physical objects, in effect, return to the same length to their original length in the Stay-At-Home, but there is no record of their having shrunk? If it's a rigid (not elastic) object, how can it shrink and then elongate back to normal? It might get broken in such situation.
On flexible and rigid nouns

DEFF Research Database (Denmark)

Rijkhoff, Jan

2008-01-01

Studies in Language 32-3 (2008), 727-752. Special issue: Parts of Speech: Descriptive tools, theoretical constructs Jan Rijkhoff - On flexible and rigid nouns This article argues that in addition to the flexible lexical categories in Hengeveld’s classification of parts-of-speech systems (Contentive......, Non-Verb, Modifier), there are also flexible word classes within the rigid lexical category Noun (Set Noun, Sort Noun, General Noun). Members of flexible word classes are characterized by their vague semantics, which in the case of nouns means that values for the semantic features Shape...... and Homogeneity are either left undetermined or they are specified in such a way that they do not quite match the properties of the kind of entity denoted by the flexible item in the external world. I will then argue that flexible word classes constitute a proper category (i.e. they are not the result of a merger...
Rigidity spectrum of Forbush decrease

International Nuclear Information System (INIS)

Sakakibara, S.; Munakata, K.; Nagashima, K.

1985-01-01

Using data from neutron monitors and muon telescopes at surface and underground stations, the average rigidity spectrum of Forbush decreases (Fds) during the period of 1978-1982 were obtained. Thirty eight Ed-events are classified into two groups, Hard Fd and Soft FD according to size of Fd at the Sakashita station. It is found that a spectral form of a fractional-power type (P to the-gamma sub 1 (P+P sub c) to the -gamma sub2) is more suitable than that of a power-exponential type or of a power type with an upper limiting rigidity. The best fitted spectrum of the fractional-power type is expressed by gamma sub1 = 0.37, gamma sub2 = 0.89 and P subc = 10 GV for Hard Fd and gamma sub1 = 0.77, gamma sub2 = 1.02 and P sub c - 14GV for Soft Fd
An evaluation of canonical forms for non-rigid 3D shape retrieval

OpenAIRE

Pickup, David; Liu, Juncheng; Sun, Xianfang; Rosin, Paul L.; Martin, Ralph R.; Cheng, Zhiquan; Lian, Zhouhui; Nie, Sipin; Jin, Longcun; Shamai, Gil; Sahillioğlu, Yusuf; Kavan, Ladislav

2018-01-01

Canonical forms attempt to factor out a non-rigid shape’s pose, giving a pose-neutral shape. This opens up the\\ud possibility of using methods originally designed for rigid shape retrieval for the task of non-rigid shape retrieval.\\ud We extend our recent benchmark for testing canonical form algorithms. Our new benchmark is used to evaluate a\\ud greater number of state-of-the-art canonical forms, on five recent non-rigid retrieval datasets, within two different\\ud retrieval frameworks. A tota...
Blast wave interaction with a rigid surface

International Nuclear Information System (INIS)

Josey, T.; Whitehouse, D.R.; Ripley, R.C.; Dionne, J.P.

2004-01-01

A simple model used to investigate blast wave interactions with a rigid surface is presented. The model uses a constant volume energy source analogue to predict pressure histories at gauges located directly above the charge. A series of two-dimensional axi-symmetric CFD calculations were performed, varying the height of the charge relative to the ground. Pressure histories, along with isopycnic plots are presented to evaluate the effects of placing a charge in close proximity to a rigid surface. When a charge is placed near a solid surface the pressure histories experienced at gauges above the charge indicate the presence of two distinct pressure peaks. The first peak is caused by the primary shock and the second peak is a result of the wave reflections from the rigid surface. As the distance from the charge to the wall is increased the magnitude of the second pressure peak is reduced, provided that the distance between the charge and the gauge is maintained constant. The simple model presented is able to capture significant, predictable flow features. (author)
Digital squares

DEFF Research Database (Denmark)

Forchhammer, Søren; Kim, Chul E

1988-01-01

Digital squares are defined and their geometric properties characterized. A linear time algorithm is presented that considers a convex digital region and determines whether or not it is a digital square. The algorithm also determines the range of the values of the parameter set of its preimages....... The analysis involves transforming the boundary of a digital region into parameter space of slope and y-intercept...
Hydrodynamics of a flexible plate between pitching rigid plates

Science.gov (United States)

Kim, Junyoung; Kim, Daegyoum

2017-11-01

The dynamics of a flexible plate have been studied as a model problem in swimming and flying of animals and fluid-structure interaction of plants and flags. Motivated by fish schooling and an array of sea grasses, we investigate the dynamics of a flexible plate closely placed between two pitching rigid plates. In most studies on passive deformation of the flexible plate, the plate is immersed in a uniform flow or a wavy flow. However, in this study, the flexible plate experiences periodic deformation by the oscillatory flow generated by the prescribed pitching motion of the rigid plates. In our model, the pitching axes of the rigid plates and the clamping position of the flexible plate are aligned on the same line. The flexible plate shows various responses depending on length and pitching frequency of rigid plates, thickness of a flexible plate, and free-stream velocity. To find the effect of each variable on the response of the flexible plate, amplitude of a trailing edge and modal contribution of a flapping motion are compared, and flow structure around the flexible plate is examined.
A new method for synthesizing fluid inclusions in fused silica capillaries containing organic and inorganic material

Science.gov (United States)

Chou, I.-Ming; Song, Yucai; Burruss, R. C.

2008-11-01

Considerable advances in our understanding of physicochemical properties of geological fluids and their roles in many geological processes have been achieved by the use of synthetic fluid inclusions. We have developed a new method to synthesize fluid inclusions containing organic and inorganic material in fused silica capillary tubing. We have used both round (0.3 mm OD and 0.05 or 0.1 mm ID) and square cross-section tubing (0.3 × 0.3 mm with 0.05 × 0.05 mm or 0.1 × 0.1 mm cavities). For microthermometric measurements in a USGS-type heating-cooling stage, sample capsules must be less than 25 mm in length. The square-sectioned capsules have the advantage of providing images without optical distortion. However, the maximum internal pressure ( P; about 100 MPa at 22 °C) and temperature ( T; about 500 °C) maintained by the square-sectioned capsules are less than those held by the round-sectioned capsules (about 300 MPa at room T, and T up to 650 °C). The fused silica capsules can be applied to a wide range of problems of interest in fluid inclusion and hydrothermal research, such as creating standards for the calibration of thermocouples in heating-cooling stages and frequency shifts in Raman spectrometers. The fused silica capsules can also be used as containers for hydrothermal reactions, especially for organic samples, including individual hydrocarbons, crude oils, and gases, such as cracking of C 18H 38 between 350 and 400 °C, isotopic exchanges between C 18H 38 and D 2O and between C 19D 40 and H 2O at similar temperatures. Results of these types of studies provide information on the kinetics of oil cracking and the changes of oil composition under thermal stress. When compared with synthesis of fluid inclusions formed by healing fractures in quartz or other minerals or by overgrowth of quartz at elevated P- T conditions, the new fused-silica method has the following advantages: (1) it is simple; (2) fluid inclusions without the presence of water can be
Rigidity of the magic pentagram game

Science.gov (United States)

Kalev, Amir; Miller, Carl A.

2018-01-01

A game is rigid if a near-optimal score guarantees, under the sole assumption of the validity of quantum mechanics, that the players are using an approximately unique quantum strategy. Rigidity has a vital role in quantum cryptography as it permits a strictly classical user to trust behavior in the quantum realm. This property can be traced back as far as 1998 (Mayers and Yao) and has been proved for multiple classes of games. In this paper we prove ridigity for the magic pentagram game, a simple binary constraint satisfaction game involving two players, five clauses and ten variables. We show that all near-optimal strategies for the pentagram game are approximately equivalent to a unique strategy involving real Pauli measurements on three maximally-entangled qubit pairs.
Rigidity of the magic pentagram game.

Science.gov (United States)

Kalev, Amir; Miller, Carl A

2018-01-01

A game is rigid if a near-optimal score guarantees, under the sole assumption of the validity of quantum mechanics, that the players are using an approximately unique quantum strategy. Rigidity has a vital role in quantum cryptography as it permits a strictly classical user to trust behavior in the quantum realm. This property can be traced back as far as 1998 (Mayers and Yao) and has been proved for multiple classes of games. In this paper we prove ridigity for the magic pentagram game, a simple binary constraint satisfaction game involving two players, five clauses and ten variables. We show that all near-optimal strategies for the pentagram game are approximately equivalent to a unique strategy involving real Pauli measurements on three maximally-entangled qubit pairs.
Elastic properties of rigid fiber-reinforced composites

Science.gov (United States)

Chen, J.; Thorpe, M. F.; Davis, L. C.

1995-05-01

We study the elastic properties of rigid fiber-reinforced composites with perfect bonding between fibers and matrix, and also with sliding boundary conditions. In the dilute region, there exists an exact analytical solution. Around the rigidity threshold we find the elastic moduli and Poisson's ratio by decomposing the deformation into a compression mode and a rotation mode. For perfect bonding, both modes are important, whereas only the compression mode is operative for sliding boundary conditions. We employ the digital-image-based method and a finite element analysis to perform computer simulations which confirm our analytical predictions.
Rigid pricing and rationally inattentive consumer

Czech Academy of Sciences Publication Activity Database

Matějka, Filip

158 B, July (2015), s. 656-678 ISSN 0022-0531 Institutional support: RVO:67985998 Keywords : rational inattention * imperfect information * nominal rigidity Subject RIV: AH - Economics Impact factor: 1.097, year: 2015
Initial Development of an Electronic Testis Rigidity Tester

Directory of Open Access Journals (Sweden)

Petros Mirilas

2011-01-01

Full Text Available We aimed to develop our previously presented mechanical device, the Testis Rigidity Tester (TRT, into an electronic system (Electronic Testis Rigidity Tester, ETRT by applying tactile imaging, which has been used successfully with other solid organs. A measuring device, located at the front end of the ETRT incorporates a tactile sensor comprising an array of microsensors. By application of a predetermined deformation of 2 mm, increased pressure alters linearly the resistance of each microsensor, producing changes of voltage. These signals were amplified, filtered, and digitized, and then processed by an electronic collector system, which presented them as a color-filled contour plot of the area of the testis coming into contact with the sensor. Testis models of different rigidity served for initial evaluation of ETRT; their evacuated central spaces contained different, increasing glue masses. An independent method of rigidity measurement, using an electric weight scale and a micrometer, showed that the more the glue injected, the greater the force needed for a 2-mm deformation. In a preliminary test, a single sensor connected to a multimeter showed similar force measurement for the same deformation in these phantoms. For each of the testis models compressed in the same manner, the ETRT system offered a map of pressures, represented by a color scale within the contour plot of the contact area with the sensor. ETRT found certain differences in rigidity between models that had escaped detection by a blind observer. ETRT is easy to use and provides a color-coded “insight“ of the testis internal structure. After experimental testing, it could be valuable in intraoperative evaluation of testes, so that the surgeon can decide about orchectomy or orcheopexy.
Signature of Thermal Rigidity Percolation

International Nuclear Information System (INIS)

Huerta, Adrián

2013-01-01

To explore the role that temperature and percolation of rigidity play in determining the macroscopic properties, we propose a model that adds translational degrees of freedom to the spins of the well known Ising hamiltonian. In particular, the Ising model illustrate the longstanding idea that the growth of correlations on approach to a critical point could be describable in terms of the percolation of some sort of p hysical cluster . For certain parameters of this model we observe two well defined peaks of C V , that suggest the existence of two kinds of p hysical percolation , namely connectivity and rigidity percolation. Thermal fluctuations give rise to two different kinds of elementary excitations, i.e. droplets and configuron, as suggested by Angell in the framework of a bond lattice model approach. The later is reflected in the fluctuations of redundant constraints that gives stability to the structure and correlate with the order parameter
Rigid pricing and rationally inattentive consumer

Czech Academy of Sciences Publication Activity Database

Matějka, Filip

158 B, July (2015), s. 656-678 ISSN 0022-0531 Institutional support: PRVOUK-P23 Keywords : rational inattention * imperfect information * nominal rigidity Subject RIV: AH - Economics Impact factor: 1.097, year: 2015
Accuracy limit of rigid 3-point water models

Science.gov (United States)

Izadi, Saeed; Onufriev, Alexey V.

2016-08-01

Classical 3-point rigid water models are most widely used due to their computational efficiency. Recently, we introduced a new approach to constructing classical rigid water models [S. Izadi et al., J. Phys. Chem. Lett. 5, 3863 (2014)], which permits a virtually exhaustive search for globally optimal model parameters in the sub-space that is most relevant to the electrostatic properties of the water molecule in liquid phase. Here we apply the approach to develop a 3-point Optimal Point Charge (OPC3) water model. OPC3 is significantly more accurate than the commonly used water models of same class (TIP3P and SPCE) in reproducing a comprehensive set of liquid bulk properties, over a wide range of temperatures. Beyond bulk properties, we show that OPC3 predicts the intrinsic charge hydration asymmetry (CHA) of water — a characteristic dependence of hydration free energy on the sign of the solute charge — in very close agreement with experiment. Two other recent 3-point rigid water models, TIP3PFB and H2ODC, each developed by its own, completely different optimization method, approach the global accuracy optimum represented by OPC3 in both the parameter space and accuracy of bulk properties. Thus, we argue that an accuracy limit of practical 3-point rigid non-polarizable models has effectively been reached; remaining accuracy issues are discussed.

Inclusive measurements on diffractive processes in ep collisions

International Nuclear Information System (INIS)

Janssen, Xavier

2007-01-01

Measurements from the H1 and ZEUS collaborations of the diffractive deep-inelastic scattering process, ep → eXY, where Y is a proton or a low mass proton excitation, are presented for photon virtualities in the range 2.2 2 2 and squared four-momentum transfer at the proton vertex satisfying | t | 2 . Diffractive parton distribution functions and their uncertainties are determined from a next-to-leading order DGLAP QCD analysis. Combining measurements of the inclusive diffractive deep-inelastic scattering process with an analysis of diffractive di jet production allows a very sensitive determination of both quark and gluon distributions. (author)
Verification of the Rigidity of the Coulomb Field in Motion

Science.gov (United States)

Blinov, S. V.; Bulyzhenkov, I. É.

2018-06-01

Laplace, analyzing the stability of the Solar System, was the first to calculate that the velocity of the motion of force fields can significantly exceed the velocity of light waves. In electrodynamics, the Coulomb field should rigidly accompany its source for instantaneous force action in distant regions. Such rigid motion was recently inferred from experiments at the Frascati Beam Test Facility with short beams of relativistic electrons. The comments of the authors on their observations are at odds with the comments of theoreticians on retarded potentials, which motivates a detailed study of the positions of both sides. Predictions of measurements, based on the Lienard-Wiechert potentials, are used to propose an unambiguous scheme for testing the rigidity of the Coulomb field. Realization of the proposed experimental scheme could independently refute or support the assertions of the Italian physicists regarding the rigid motion of Coulomb fields and likewise the nondual field approach to macroscopic reality.
Financial Constraints and Nominal Price Rigidities

DEFF Research Database (Denmark)

Menno, Dominik Francesco; Balleer, Almut; Hristov, Nikolay

This paper investigates how financial market imperfections and the frequency of price adjustment interact. Based on new firm-level evidence for Germany, we document that financially constrained firms adjust prices more often than their unconstrained counterparts, both upwards and downwards. We show...... that these empirical patterns are consistent with a partial equilibrium menu-cost model with a working capital constraint. We then use the model to show how the presence of financial frictions changes profits and the price distribution of firms compared to a model without financial frictions. Our results suggest...... that tighter financial constraints are associated with higher nominal rigidities, higher prices and lower output. Moreover, in response to aggregate shocks, aggregate price rigidity moves substantially, the response of inflation is dampened, while output reacts more in the presence of financial frictions...
Rigid supersymmetry with boundaries

Energy Technology Data Exchange (ETDEWEB)

Belyaev, D.V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Van Nieuwenhuizen, P. [State Univ. of New York, Stony Brook, NY (United States). C.N. Yang Inst. for Theoretical Physics

2008-01-15

We construct rigidly supersymmetric bulk-plus-boundary actions, both in x-space and in superspace. For each standard supersymmetric bulk action a minimal supersymmetric bulk-plus-boundary action follows from an extended F- or D-term formula. Additional separately supersymmetric boundary actions can be systematically constructed using co-dimension one multiplets (boundary superfields). We also discuss the orbit of boundary conditions which follow from the Euler-Lagrange variational principle. (orig.)
Frontal Tasks and Behavior in Rigid or Tremor-Dominant Parkinson Disease.

Science.gov (United States)

Moretti, Rita; Milner, Vera; Caruso, Paola; Gazzin, Silvia; Rumiati, Raffaella

2017-08-01

Parkinson disease (PD) is not an unambiguous entity, and there is a general consensus for the statement that an akinetic-rigid dominant type of presentation has a worse prognosis, in the follow-up. The aim of our study was to examine the differences in frontal tasks and behavior, in 2 PD naive groups: the rigid and the tremor-dominant types of presentation, according to motor scores. Our study has showed some important differences in frontal tasks and in behavior, performing more apathy, aggressiveness, and irritability in the rigid type, and more depression and anxiety in the tremor-dominant type. The former group causes the caregiver more distress and has a very rapid disease progression. It can be argued that rigid type PD presentation needs specific dedicated cares and more strong clinical attention.
Pharmacological targeting of membrane rigidity: implications on cancer cell migration and invasion

International Nuclear Information System (INIS)

Braig, Simone; Stoiber, Katharina; Zahler, Stefan; Vollmar, Angelika M

2015-01-01

The invasive potential of cancer cells strongly depends on cellular stiffness, a physical quantity that is not only regulated by the mechanical impact of the cytoskeleton but also influenced by the membrane rigidity. To analyze the specific role of membrane rigidity in cancer progression, we treated cancer cells with the Acetyl-CoA carboxylase inhibitor Soraphen A and revealed an alteration of the phospholipidome via mass spectrometry. Migration, invasion, and cell death assays were employed to relate this alteration to functional consequences, and a decrease of migration and invasion without significant impact on cell death has been recorded. Fourier fluctuation analysis of giant plasma membrane vesicles showed that Soraphen A increases membrane rigidity of carcinoma cell membranes. Mechanical measurements of the creep deformation response of whole intact cells were performed using the optical stretcher. The increase in membrane rigidity was observed in one cell line without changing the creep deformation response indicating no restructuring of the cytoskeleton. These data indicate that the increase of membrane rigidity alone is sufficient to inhibit invasiveness of cancer cells, thus disclosing the eminent role of membrane rigidity in migratory processes. (paper)
Non-rigid image registration using bone growth model

DEFF Research Database (Denmark)

Bro-Nielsen, Morten; Gramkow, Claus; Kreiborg, Sven

1997-01-01

Non-rigid registration has traditionally used physical models like elasticity and fluids. These models are very seldom valid models of the difference between the registered images. This paper presents a non-rigid registration algorithm, which uses a model of bone growth as a model of the change...... between time sequence images of the human mandible. By being able to register the images, this paper at the same time contributes to the validation of the growth model, which is based on the currently available medical theories and knowledge...
Acoustic scattering of a Bessel vortex beam by a rigid fixed spheroid

Science.gov (United States)

Mitri, F. G.

2015-12-01

Partial-wave series representation of the acoustic scattering field of high-order Bessel vortex beams by rigid oblate and prolate spheroids using the modal matching method is developed. The method, which is applicable to slightly elongated objects at low-to-moderate frequencies, requires solving a system of linear equations which depends on the partial-wave index n and the order of the Bessel vortex beam m using truncated partial-wave series expansions (PWSEs), and satisfying the Neumann boundary condition for a rigid immovable surface in the least-squares sense. This original semi-analytical approach developed for Bessel vortex beams is demonstrated for finite oblate and prolate spheroids, where the mathematical functions describing the spheroidal geometry are written in a form involving single angular (polar) integrals that are numerically computed. The transverse (θ = π / 2) and 3D scattering directivity patterns are evaluated in the far-field for both prolate and oblate spheroids, with particular emphasis on the aspect ratio (i.e., the ratio of the major axis over the minor axis of the spheroid) not exceeding 3:1, the half-cone angle β and order m of the Bessel vortex beam, as well as the dimensionless size parameter kr0. Periodic oscillations in the magnitude plots of the far-field scattering form function are observed, which result from the interference of the reflected waves with the circumferential (Franz') waves circumnavigating the surface of the spheroid in the surrounding fluid. Moreover, the 3D directivity patterns illustrate the far-field scattering from the spheroid, that vanishes in the forward (θ = 0) and backward (θ = π) directions. Particular applications in underwater acoustics and scattering, acoustic levitation and the detection of submerged elongated objects using Bessel vortex waves to name a few, would benefit from the results of the present investigation.
Measurement of inclusive jet production in deep-inelastic scattering at high Q and determination of the strong coupling

Science.gov (United States)

H1 Collaboration; Aktas, A.; Alexa, C.; Andreev, V.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Cantun Avila, K. B.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J. G.; Coughlan, J. A.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Daum, K.; Deak, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; de Roeck, A.; de Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkiewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Grell, B. R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Heinzelmann, G.; Helebrant, C.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Jacquet, M.; Janssen, M. E.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knutsson, A.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laštovička-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G. D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Plačakytė, R.; Polifka, R.; Povh, B.; Preda, T.; Prideaux, P.; Radescu, V.; Rahmat, A. J.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Sloan, T.; Smiljanic, I.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Staykova, Z.; Steder, M.; Stella, B.; Stiewe, J.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Toll, T.; Tomasz, F.; Tran, T. H.; Traynor, D.; Trinh, T. N.; Truöl, P.; Tsakov, I.; Tseepeldorj, B.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Utkin, D.; Valkárová, A.; Vallée, C.; van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wissing, Ch.; Wolf, R.; Wünsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

2007-09-01

Inclusive jet production is studied in neutral current deep-inelastic positron proton scattering at large four momentum transfer squared Q>150GeV with the H1 detector at HERA. Single and double differential inclusive jet cross sections are measured as a function of Q and of the transverse energy E of the jets in the Breit frame. The measurements are found to be well described by calculations at next-to-leading order in perturbative QCD. The running of the strong coupling is demonstrated and the value of α(M) is determined. The ratio of the inclusive jet cross section to the inclusive neutral current cross section is also measured and used to extract a precise value for α(M)=0.1193±0.0014(exp.)-0.0030+0.0047(th.)±0.0016(pdf).
Lax-pair operators for squared-sum and squared-difference eigenfunctions

International Nuclear Information System (INIS)

Ichikawa, Yoshihiko; Iino, Kazuhiro.

1984-10-01

Inter-relationship between various representations of the inverse scattering transformation is established by examining eigenfunctions of Lax-pair operators of the sine-Gordon equation and the modified Korteweg-de Vries equation. In particular, it is shown explicitly that there exists Lax-pair operators for the squared-sum and squared-difference eigenfunctions of the Ablowitz-Kaup-Newell-Segur inverse scattering transformation. (author)
Singular solutions for the rigid plastic double slip and rotation model under plane strain

Science.gov (United States)

Alexandrov, S.; Lyamina, E.

2018-02-01

In the mechanics of granular and other materials the system of equations comprising the rigid plastic double slip and rotation model together with the stress equilibrium equations under plane strain conditions forms a hyperbolic system. Boundary value problems for this system of equations can involve a frictional interface. An envelope of characteristics may coincide with this interface. In this case, the solution is singular. In particular, some components of the strain rate tensor approach infinity in the vicinity of the frictional interface. Such behavior of solutions is in qualitative agreement with experimental data that show that a narrow layer of localized plastic deformation is often generated near frictional interfaces. The present paper deals with asymptotic analysis of the aforementioned system of equations in the vicinity of an envelope of characteristics. It is shown that the shear strain rate and the spin component in a local coordinate system connected to the envelope follow an inverse square root rule in its vicinity.
Towards Sub-Microarsecond Rigid Earth Nutation Series in the Hamiltonian Theory

National Research Council Canada - National Science Library

Souchay, Jean; Folgueira, M

2000-01-01

...) are based on the works of Kinoshita (1977) and Wahr (1979). In Kinoshita's work, the rigid Earth nutation series were calculated by the application of the Hamiltonian canonical equations to the rotation of the rigid and elliptical Earth...
Forward and inverse viscoelastic wave scattering by irregular inclusions for shear wave elastography.

Science.gov (United States)

Bernard, Simon; Cloutier, Guy

2017-10-01

Inversion methods in shear wave elastography use simplifying assumptions to recover the mechanical properties of soft tissues. Consequently, these methods suffer from artifacts when applied to media containing strong stiffness contrasts, and do not provide a map of the viscosity. In this work, the shear wave field recorded inside and around an inclusion was used to estimate the viscoelastic properties of the inclusion and surrounding medium, based on an inverse problem approach assuming local homogeneity of both media. An efficient semi-analytical method was developed to model the scattering of an elastic wave by an irregular inclusion, based on a decomposition of the field by Bessel functions and on a decomposition of the boundaries as Fourier series. This model was validated against finite element modeling. Shear waves were experimentally induced by acoustic radiation force in soft tissue phantoms containing stiff and soft inclusions, and the displacement field was imaged at a high frame rate using plane wave imaging. A nonlinear least-squares algorithm compared the model to the experimental data and adjusted the geometrical and mechanical parameters. The estimated shear storage and loss moduli were in good agreement with reference measurements, as well as the estimated inclusion shape. This approach provides an accurate estimation of geometry and viscoelastic properties for a single inclusion in a homogeneous background in the context of radiation force elastography.
A DNA Origami Mechanical Device for the Regulation of Microcosmic Structural Rigidity.

Science.gov (United States)

Wan, Neng; Hong, Zhouping; Wang, Huading; Fu, Xin; Zhang, Ziyue; Li, Chao; Xia, Han; Fang, Yan; Li, Maoteng; Zhan, Yi; Yang, Xiangliang

2017-11-01

DNA origami makes it feasible to fabricate a tremendous number of DNA nanostructures with various geometries, dimensions, and functionalities. Moreover, an increasing amount of research on DNA nanostructures is focused on biological and biomedical applications. Here, the reversible regulation of microcosmic structural rigidity is accomplished using a DNA origami device in vitro. The designed DNA origami monomer is composed of an internal central axis and an external sliding tube. Due to the external tube sliding, the device transforms between flexible and rigid states. By transporting the device into the liposome, the conformational change of the origami device induces a structural change in the liposome. The results obtained demonstrate that the programmed DNA origami device can be applied to regulate the microcosmic structural rigidity of liposomes. Because microcosmic structural rigidity is important to cell proliferation and function, the results obtained potentially provide a foundation for the regulation of cell microcosmic structural rigidity using DNA nanostructures. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Irrational Square Roots

Science.gov (United States)

Misiurewicz, Michal

2013-01-01

If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?
Botulinum toxin in myotonia congenita: it does not help against rigidity and pain.

Science.gov (United States)

Dressler, Dirk; Adib Saberi, Fereshte

2014-05-01

Botulinum toxin (BT) is a potent local muscle relaxant with analgetic properties. Myotonia congenita (MC) is a genetic disorder producing muscle rigidity and pain. BT injected into the trapezius produced mild paresis, but no effect on rigidity and pain. There were no signs of systemic effects. Lack of BT efficacy on MC rigidity confirms its origin from muscle membrane dysfunction rather than from inappropriate neuromuscular activation. Lack of BT efficacy on pain could be caused by lack of anti-rigidity effect. It could also be due to separate non-muscular pain mechanisms unresponsive to BT.
Calculating ensemble averaged descriptions of protein rigidity without sampling.

Science.gov (United States)

González, Luis C; Wang, Hui; Livesay, Dennis R; Jacobs, Donald J

2012-01-01

Previous works have demonstrated that protein rigidity is related to thermodynamic stability, especially under conditions that favor formation of native structure. Mechanical network rigidity properties of a single conformation are efficiently calculated using the integer body-bar Pebble Game (PG) algorithm. However, thermodynamic properties require averaging over many samples from the ensemble of accessible conformations to accurately account for fluctuations in network topology. We have developed a mean field Virtual Pebble Game (VPG) that represents the ensemble of networks by a single effective network. That is, all possible number of distance constraints (or bars) that can form between a pair of rigid bodies is replaced by the average number. The resulting effective network is viewed as having weighted edges, where the weight of an edge quantifies its capacity to absorb degrees of freedom. The VPG is interpreted as a flow problem on this effective network, which eliminates the need to sample. Across a nonredundant dataset of 272 protein structures, we apply the VPG to proteins for the first time. Our results show numerically and visually that the rigidity characterizations of the VPG accurately reflect the ensemble averaged [Formula: see text] properties. This result positions the VPG as an efficient alternative to understand the mechanical role that chemical interactions play in maintaining protein stability.
Experimental consequences of predicted charge rigidity of superconductors

Energy Technology Data Exchange (ETDEWEB)

Hirsch, J.E., E-mail: jhirsch@ucsd.edu [Department of Physics, University of California, San Diego, La Jolla, CA 92093-0319 (United States)

2012-08-15

The theory of hole superconductivity predicts that in superconductors the charged superfluid is about a million times more rigid than the normal electron fluid. We point out that this physics should give rise to large changes in the bulk and surface plasmon dispersion relations of metals entering the superconducting state, that have not yet been experimentally detected and would be in stark contradiction with the expected behavior within conventional BCS-London theory. We also propose that this explains the puzzling experimental observations of Avramenko et al. on electron sound propagation in superconductors and the puzzling experiments of de Heer et al. detecting large electric dipole moments in small metal clusters, as well as the Tao effect on aggregation of superconducting microparticles in an electric field. Associated with the enhanced charge rigidity is a large increase in the electric screening length of superconductors at low temperatures that has not yet been experimentally detected. The physical origin of the enhanced charge rigidity and its relation to other aspects of the theory of hole superconductivity is discussed.
Use of Terrestrial Laser Scanner for Rigid Airport Pavement Management

Directory of Open Access Journals (Sweden)

Maurizio Barbarella

2017-12-01

Full Text Available The evaluation of the structural efficiency of airport infrastructures is a complex task. Faulting is one of the most important indicators of rigid pavement performance. The aim of our study is to provide a new method for faulting detection and computation on jointed concrete pavements. Nowadays, the assessment of faulting is performed with the use of laborious and time-consuming measurements that strongly hinder aircraft traffic. We proposed a field procedure for Terrestrial Laser Scanner data acquisition and a computation flow chart in order to identify and quantify the fault size at each joint of apron slabs. The total point cloud has been used to compute the least square plane fitting those points. The best-fit plane for each slab has been computed too. The attitude of each slab plane with respect to both the adjacent ones and the apron reference plane has been determined by the normal vectors to the surfaces. Faulting has been evaluated as the difference in elevation between the slab planes along chosen sections. For a more accurate evaluation of the faulting value, we have then considered a few strips of data covering rectangular areas of different sizes across the joints. The accuracy of the estimated quantities has been computed too.
Use of Terrestrial Laser Scanner for Rigid Airport Pavement Management.

Science.gov (United States)

Barbarella, Maurizio; D'Amico, Fabrizio; De Blasiis, Maria Rosaria; Di Benedetto, Alessandro; Fiani, Margherita

2017-12-26

The evaluation of the structural efficiency of airport infrastructures is a complex task. Faulting is one of the most important indicators of rigid pavement performance. The aim of our study is to provide a new method for faulting detection and computation on jointed concrete pavements. Nowadays, the assessment of faulting is performed with the use of laborious and time-consuming measurements that strongly hinder aircraft traffic. We proposed a field procedure for Terrestrial Laser Scanner data acquisition and a computation flow chart in order to identify and quantify the fault size at each joint of apron slabs. The total point cloud has been used to compute the least square plane fitting those points. The best-fit plane for each slab has been computed too. The attitude of each slab plane with respect to both the adjacent ones and the apron reference plane has been determined by the normal vectors to the surfaces. Faulting has been evaluated as the difference in elevation between the slab planes along chosen sections. For a more accurate evaluation of the faulting value, we have then considered a few strips of data covering rectangular areas of different sizes across the joints. The accuracy of the estimated quantities has been computed too.

Bang-Bang Practical Stabilization of Rigid Bodies

Science.gov (United States)

Serpelloni, Edoardo

In this thesis, we study the problem of designing a practical stabilizer for a rigid body equipped with a set of actuators generating only constant thrust. Our motivation stems from the fact that modern space missions are required to accurately control the position and orientation of spacecraft actuated by constant-thrust jet-thrusters. To comply with the performance limitations of modern thrusters, we design a feedback controller that does not induce high-frequency switching of the actuators. The proposed controller is hybrid and it asymptotically stabilizes an arbitrarily small compact neighborhood of the target position and orientation of the rigid body. The controller is characterized by a hierarchical structure comprising of two control layers. At the low level of the hierarchy, an attitude controller stabilizes the target orientation of the rigid body. At the high level, after the attitude controller has steered the rigid body sufficiently close to its desired orientation, a position controller stabilizes the desired position. The size of the neighborhood being stabilized by the controller can be adjusted via a proper selection of the controller parameters. This allows us to stabilize the rigid body to virtually any degree of accuracy. It is shown that the controller, even in the presence of measurement noise, does not induce high-frequency switching of the actuators. The key component in the design of the controller is a hybrid stabilizer for the origin of double-integrators affected by bounded external perturbations. Specifically, both the position and the attitude stabilizers consist of multiple copies of such a double-integrator controller. The proposed controller is applied to two realistic spacecraft control problems. First, we apply the position controller to the problem of stabilizing the relative position between two spacecraft flying in formation in the vicinity of the L2 libration point of the Sun-Earth system as a part of a large space telescope
Square through tube

International Nuclear Information System (INIS)

Akita, Junji; Honma, Toei.

1975-01-01

Object: To provide a square through tube involving thermal movement in pipelines such as water supply pump driving turbine exhaust pipe (square-shaped), which is wide in freedom with respect to shape and dimension thereof for efficient installation at site. Structure: In a through tube to be airtightly retained for purpose of decontamination in an atomic power plant, comprising a seal rubber plate, a band and a bolt and a nut for securing said plate, the seal rubber plate being worked into the desired shape so that it may be placed in intimate contact with the concrete floor surface by utilization of elasticity of rubber, thereby providing airtightness at a corner portion of the square tube. (Kamimura, M.)
Evaluation for rigidity of box construction of nuclear reactor building

International Nuclear Information System (INIS)

Yamakawa, Tetsuo

1979-01-01

A huge box-shaped structure (hereafter, called box construction) of reinforced concrete is presently utilized as the reactor building structure in nuclear power plants. Evaluation of the rigidity of the huge box construction is required for making a vibration analysis model of nuclear reactor buildings. It is necessary to handle the box construction as the plates to which the force in plane is applied. This paper describes that the bending theory in elementary beam theory is equivalent to a peculiar, orthogonally anisotropic plate, the shearing rigidity and film rigidity in y direction of which are put to infinity and the Poisson's ratio is put to zero, viewed from the two-dimensional theory of elasticity. The form factor of 1.2 for shearing deformation in rectangular cross section was calculated from the parabolic distribution of shearing stress intensity, and it is the maximum value. The factor is equal to 1.2 for slender beams, but smaller than 1.2 for short and thick beams, having tendency to converge to 1.0. The non-conformity of boundary conditions regarding the shearing force at the both ends of cantilevers does not affect very seriously the evaluation of shearing rigidity. From the above results, it was found that the application of the theory to the box construction was able to give the rigidity evaluation with sufficient engineering accuracy. The theory can also be applied to the evaluation of tube type ultrahigh buildings. (Wakatsuki, Y.)
All 36 exactly solvable solutions of eigenvalues for nuclear electric quadrupole interaction Hamiltonian and equivalent rigid asymmetric rotor with expanded characteristic equation listing

Energy Technology Data Exchange (ETDEWEB)

Menke, Lorenz Harry, E-mail: lnz2004@mindspring.com [University of Pittsburgh (United States)

2012-05-15

This paper derives all 36 analytical solutions of the energy eigenvalues for nuclear electric quadrupole interaction Hamiltonian and equivalent rigid asymmetric rotor for polynomial degrees 1 through 4 using classical algebraic theory. By the use of double-parameterization the full general solution sets are illustrated in a compact, symmetric, structural, and usable form that is valid for asymmetry parameter {eta} is an element of (- {infinity}, + {infinity}). These results are useful for code developers in the area of Perturbed Angular Correlation (PAC), Nuclear Quadrupole Resonance (NQR) and rotational spectroscopy who want to offer exact solutions whenever possible, rather that resorting to numerical solutions. In addition, by using standard linear algebra methods, the characteristic equations of all integer and half-integer spins I from 0 to 15, inclusive are represented in a compact and naturally parameterized form that illustrates structure and symmetries. This extends Nielson's listing of characteristic equations for integer spins out to I = 15, inclusive.
Frictionless contact of a rigid punch indenting a transversely isotropic elastic layer

Directory of Open Access Journals (Sweden)

Rajesh Patra

2016-03-01

Full Text Available This article is concerned with the study of frictionless contact between a rigid punch and a transversely isotropic elastic layer. The rigid punch is assumed to be axially symmetric and is being pressed towards the layer by an applied concentrated load. The layer is resting on a rigid base and is assumed to be ufficiently thick in comparison with the amount of indentation by the rigid punch. The relationship between the applied load $P$ and the contact area is obtained by solving the mathematically formulated problem through use of Hankel transform of different order. Effect of indentation on the distribution of normal stress at the surface as well as the relationship between the applied load and the area of contact have been shown graphically.
Weighted conditional least-squares estimation

International Nuclear Information System (INIS)

Booth, J.G.

1987-01-01

A two-stage estimation procedure is proposed that generalizes the concept of conditional least squares. The method is instead based upon the minimization of a weighted sum of squares, where the weights are inverses of estimated conditional variance terms. Some general conditions are given under which the estimators are consistent and jointly asymptotically normal. More specific details are given for ergodic Markov processes with stationary transition probabilities. A comparison is made with the ordinary conditional least-squares estimators for two simple branching processes with immigration. The relationship between weighted conditional least squares and other, more well-known, estimators is also investigated. In particular, it is shown that in many cases estimated generalized least-squares estimators can be obtained using the weighted conditional least-squares approach. Applications to stochastic compartmental models, and linear models with nested error structures are considered
Matrix rigidity regulates cancer cell growth and cellular phenotype.

Directory of Open Access Journals (Sweden)

Robert W Tilghman

2010-09-01

Full Text Available The mechanical properties of the extracellular matrix have an important role in cell growth and differentiation. However, it is unclear as to what extent cancer cells respond to changes in the mechanical properties (rigidity/stiffness of the microenvironment and how this response varies among cancer cell lines.In this study we used a recently developed 96-well plate system that arrays extracellular matrix-conjugated polyacrylamide gels that increase in stiffness by at least 50-fold across the plate. This plate was used to determine how changes in the rigidity of the extracellular matrix modulate the biological properties of tumor cells. The cell lines tested fall into one of two categories based on their proliferation on substrates of differing stiffness: "rigidity dependent" (those which show an increase in cell growth as extracellular rigidity is increased, and "rigidity independent" (those which grow equally on both soft and stiff substrates. Cells which grew poorly on soft gels also showed decreased spreading and migration under these conditions. More importantly, seeding the cell lines into the lungs of nude mice revealed that the ability of cells to grow on soft gels in vitro correlated with their ability to grow in a soft tissue environment in vivo. The lung carcinoma line A549 responded to culture on soft gels by expressing the differentiated epithelial marker E-cadherin and decreasing the expression of the mesenchymal transcription factor Slug.These observations suggest that the mechanical properties of the matrix environment play a significant role in regulating the proliferation and the morphological properties of cancer cells. Further, the multiwell format of the soft-plate assay is a useful and effective adjunct to established 3-dimensional cell culture models.
Matrix Rigidity Regulates Cancer Cell Growth and Cellular Phenotype

Science.gov (United States)

Tilghman, Robert W.; Cowan, Catharine R.; Mih, Justin D.; Koryakina, Yulia; Gioeli, Daniel; Slack-Davis, Jill K.; Blackman, Brett R.; Tschumperlin, Daniel J.; Parsons, J. Thomas

2010-01-01

Background The mechanical properties of the extracellular matrix have an important role in cell growth and differentiation. However, it is unclear as to what extent cancer cells respond to changes in the mechanical properties (rigidity/stiffness) of the microenvironment and how this response varies among cancer cell lines. Methodology/Principal Findings In this study we used a recently developed 96-well plate system that arrays extracellular matrix-conjugated polyacrylamide gels that increase in stiffness by at least 50-fold across the plate. This plate was used to determine how changes in the rigidity of the extracellular matrix modulate the biological properties of tumor cells. The cell lines tested fall into one of two categories based on their proliferation on substrates of differing stiffness: “rigidity dependent” (those which show an increase in cell growth as extracellular rigidity is increased), and “rigidity independent” (those which grow equally on both soft and stiff substrates). Cells which grew poorly on soft gels also showed decreased spreading and migration under these conditions. More importantly, seeding the cell lines into the lungs of nude mice revealed that the ability of cells to grow on soft gels in vitro correlated with their ability to grow in a soft tissue environment in vivo. The lung carcinoma line A549 responded to culture on soft gels by expressing the differentiated epithelial marker E-cadherin and decreasing the expression of the mesenchymal transcription factor Slug. Conclusions/Significance These observations suggest that the mechanical properties of the matrix environment play a significant role in regulating the proliferation and the morphological properties of cancer cells. Further, the multiwell format of the soft-plate assay is a useful and effective adjunct to established 3-dimensional cell culture models. PMID:20886123
Calculating ensemble averaged descriptions of protein rigidity without sampling.

Directory of Open Access Journals (Sweden)

Luis C González

Full Text Available Previous works have demonstrated that protein rigidity is related to thermodynamic stability, especially under conditions that favor formation of native structure. Mechanical network rigidity properties of a single conformation are efficiently calculated using the integer body-bar Pebble Game (PG algorithm. However, thermodynamic properties require averaging over many samples from the ensemble of accessible conformations to accurately account for fluctuations in network topology. We have developed a mean field Virtual Pebble Game (VPG that represents the ensemble of networks by a single effective network. That is, all possible number of distance constraints (or bars that can form between a pair of rigid bodies is replaced by the average number. The resulting effective network is viewed as having weighted edges, where the weight of an edge quantifies its capacity to absorb degrees of freedom. The VPG is interpreted as a flow problem on this effective network, which eliminates the need to sample. Across a nonredundant dataset of 272 protein structures, we apply the VPG to proteins for the first time. Our results show numerically and visually that the rigidity characterizations of the VPG accurately reflect the ensemble averaged [Formula: see text] properties. This result positions the VPG as an efficient alternative to understand the mechanical role that chemical interactions play in maintaining protein stability.
Square-root measurement for pure states

International Nuclear Information System (INIS)

Huang Siendong

2005-01-01

Square-root measurement is a very useful suboptimal measurement in many applications. It was shown that the square-root measurement minimizes the squared error for pure states. In this paper, the least squared error problem is reformulated and a new proof is provided. It is found that the least squared error depends only on the average density operator of the input states. The properties of the least squared error are then discussed, and it is shown that if the input pure states are uniformly distributed, the average probability of error has an upper bound depending on the least squared error, the rank of the average density operator, and the number of the input states. The aforementioned properties help explain why the square-root measurement can be effective in decoding processes
Extracting a Purely Non-rigid Deformation Field of a Single Structure

Science.gov (United States)

Demirci, Stefanie; Manstad-Hulaas, Frode; Navab, Nassir

During endovascular aortic repair (EVAR) treatment, the aortic shape is subject to severe deformation that is imposed by medical instruments such as guide wires, catheters, and the stent graft. The problem definition of deformable registration of images covering the entire abdominal region, however, is highly ill-posed. We present a new method for extracting the deformation of an aneurysmatic aorta. The outline of the procedure includes initial rigid alignment of two abdominal scans, segmentation of abdominal vessel trees, and automatic reduction of their centerline structures to one specified region of interest around the aorta. Our non-rigid registration procedure then only computes local non-rigid deformation and leaves out all remaining global rigid transformations. In order to evaluate our method, experiments for the extraction of aortic deformation fields are conducted on 15 patient datasets from endovascular aortic repair (EVAR) treatment. A visual assessment of the registration results were performed by two vascular surgeons and one interventional radiologist who are all experts in EVAR procedures.
Automatic identification of mobile and rigid substructures in molecular dynamics simulations and fractional structural fluctuation analysis.

Directory of Open Access Journals (Sweden)

Leandro Martínez

Full Text Available The analysis of structural mobility in molecular dynamics plays a key role in data interpretation, particularly in the simulation of biomolecules. The most common mobility measures computed from simulations are the Root Mean Square Deviation (RMSD and Root Mean Square Fluctuations (RMSF of the structures. These are computed after the alignment of atomic coordinates in each trajectory step to a reference structure. This rigid-body alignment is not robust, in the sense that if a small portion of the structure is highly mobile, the RMSD and RMSF increase for all atoms, resulting possibly in poor quantification of the structural fluctuations and, often, to overlooking important fluctuations associated to biological function. The motivation of this work is to provide a robust measure of structural mobility that is practical, and easy to interpret. We propose a Low-Order-Value-Optimization (LOVO strategy for the robust alignment of the least mobile substructures in a simulation. These substructures are automatically identified by the method. The algorithm consists of the iterative superposition of the fraction of structure displaying the smallest displacements. Therefore, the least mobile substructures are identified, providing a clearer picture of the overall structural fluctuations. Examples are given to illustrate the interpretative advantages of this strategy. The software for performing the alignments was named MDLovoFit and it is available as free-software at: http://leandro.iqm.unicamp.br/mdlovofit.
Strategic rigidity and foresight for technology adoption among electric utilities

International Nuclear Information System (INIS)

Shah, Arsalan Nisar; Palacios, Miguel; Ruiz, Felipe

2013-01-01

The variation in the adoption of a technology as a major source of competitive advantage has been attributed to the wide-ranging strategic foresight and the integrative capability of a firm. These possible areas of competitive advantage can exist in the periphery of the firm's strategic vision and can get easily blurred as a result of rigidness and can permeate in the decision-making process of the firm. This article explores how electric utility firms with a renewable energy portfolio can become strategically rigid in terms of adoption of newer technologies. The reluctance or delay in the adoption of new technology can be characterized as strategic rigidness, brought upon as a result of a firm's core competence or core capability in the other, more conventional technology arrangement. This paper explores the implications of such rigidness on the performance of a firm and consequently on the energy eco-system. The paper substantiates the results by emphasizing the case of Iberdrola S.A., an incumbent firm as a wind energy developer and its adoption decision behavior. We illustrate that the very routines that create competitive advantage for firms in the electric utility industry are vulnerable as they might also develop as sources of competitive disadvantage, when firms confront environmental change and uncertainty. - Highlights: • Present a firm-level perspective on technology adoption behavior among electric utilities. • Firms with mature technology can become rigid towards newer technologies. • Case study analysis of a major electric utility firm. • Implications of ‘technology rigidness’ on the energy eco-system
Rigid pricing and rationally inattentive consumer

Czech Academy of Sciences Publication Activity Database

Matějka, Filip

2010-01-01

Roč. 20, č. 2 (2010), s. 1-40 ISSN 1211-3298 R&D Projects: GA MŠk LC542 Institutional research plan: CEZ:AV0Z70850503 Keywords : rational inattention * nominal rigidity Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp409.pdf
Dimensional Metrology of Non-rigid Parts Without Specialized Inspection Fixtures =

Science.gov (United States)

Sabri, Vahid

Quality control is an important factor for manufacturing companies looking to prosper in an era of globalization, market pressures and technological advances. Functionality and product quality cannot be guaranteed without this important aspect. Manufactured parts have deviations from their nominal (CAD) shape caused by the manufacturing process. Thus, geometric inspection is a very important element in the quality control of mechanical parts. We will focus here on the geometric inspection of non-rigid (flexible) parts which are widely used in the aeronautic and automotive industries. Non-rigid parts can have different forms in a free-state condition compared with their nominal models due to residual stress and gravity loads. To solve this problem, dedicated inspection fixtures are generally used in industry to compensate for the displacement of such parts for simulating the use state in order to perform geometric inspections. These fixtures and the installation and inspection processes are expensive and time-consuming. Our aim in this thesis is therefore to develop an inspection method which eliminates the need for specialized fixtures. This is done by acquiring a point cloud from the part in a free-state condition using a contactless measuring device such as optical scanning and comparing it with the CAD model for the deviation identification. Using a non-rigid registration method and finite element analysis, we numerically inspect the profile of a non-rigid part. To do so, a simulated displacement is performed using an improved definition of displacement boundary conditions for simulating unfixed parts. In addition, we propose a numerical method for dimensional metrology of non-rigid parts in a free-state condition based on the arc length measurement by calculating the geodesic distance using the Fast Marching Method (FMM). In this thesis, we apply our developed methods on industrial non-rigid parts with free-form surfaces simulated with different types of
Multiscale multiphysics and multidomain models—Flexibility and rigidity

International Nuclear Information System (INIS)

Xia, Kelin; Opron, Kristopher; Wei, Guo-Wei

2013-01-01

The emerging complexity of large macromolecules has led to challenges in their full scale theoretical description and computer simulation. Multiscale multiphysics and multidomain models have been introduced to reduce the number of degrees of freedom while maintaining modeling accuracy and achieving computational efficiency. A total energy functional is constructed to put energies for polar and nonpolar solvation, chemical potential, fluid flow, molecular mechanics, and elastic dynamics on an equal footing. The variational principle is utilized to derive coupled governing equations for the above mentioned multiphysical descriptions. Among these governing equations is the Poisson-Boltzmann equation which describes continuum electrostatics with atomic charges. The present work introduces the theory of continuum elasticity with atomic rigidity (CEWAR). The essence of CEWAR is to formulate the shear modulus as a continuous function of atomic rigidity. As a result, the dynamics complexity of a macromolecular system is separated from its static complexity so that the more time-consuming dynamics is handled with continuum elasticity theory, while the less time-consuming static analysis is pursued with atomic approaches. We propose a simple method, flexibility-rigidity index (FRI), to analyze macromolecular flexibility and rigidity in atomic detail. The construction of FRI relies on the fundamental assumption that protein functions, such as flexibility, rigidity, and energy, are entirely determined by the structure of the protein and its environment, although the structure is in turn determined by all the interactions. As such, the FRI measures the topological connectivity of protein atoms or residues and characterizes the geometric compactness of the protein structure. As a consequence, the FRI does not resort to the interaction Hamiltonian and bypasses matrix diagonalization, which underpins most other flexibility analysis methods. FRI's computational complexity is of O
Public policies targeting labour market rigidities

Directory of Open Access Journals (Sweden)

Andreea Claudia ŞERBAN

2013-02-01

Full Text Available Labour market rigidity becomes an issue of increasing importance under conditions of shocks associated with the economic crisis due to the need to increase the adaptability and responsiveness to them. Thus, labour market policies must be directed towards mitigating rigidities caused by institutional or demographic factors or certain mismatch between demand and supply of education qualifications. This paper highlights the major role of the active labour market policies targeting the increase of labour flexibility, stressing the importance and impact on the ability to adapt quickly and effectively to macroeconomic shocks. Located on a declining trend in the years preceding the crisis, spending on labour market policies increased in 2009 in all the Member States of the European Union. Spending differences are significant between countries, Romania being at the lowest end of the European Union. This requires special attention because the increased adaptability of workers through training, as active measure, is of major importance considering the increased speed of changes in the labour market.
Rigid cohomology over Laurent series fields

CERN Document Server

Lazda, Christopher

2016-01-01

In this monograph, the authors develop a new theory of p-adic cohomology for varieties over Laurent series fields in positive characteristic, based on Berthelot's theory of rigid cohomology. Many major fundamental properties of these cohomology groups are proven, such as finite dimensionality and cohomological descent, as well as interpretations in terms of Monsky-Washnitzer cohomology and Le Stum's overconvergent site. Applications of this new theory to arithmetic questions, such as l-independence and the weight monodromy conjecture, are also discussed. The construction of these cohomology groups, analogous to the Galois representations associated to varieties over local fields in mixed characteristic, fills a major gap in the study of arithmetic cohomology theories over function fields. By extending the scope of existing methods, the results presented here also serve as a first step towards a more general theory of p-adic cohomology over non-perfect ground fields. Rigid Cohomology over Laurent Series Fields...
The Versatile Magic Square.

Science.gov (United States)

Watson, Gale A.

2003-01-01

Demonstrates the transformations that are possible to construct a variety of magic squares, including modifications to challenge students from elementary grades through algebra. Presents an example of using magic squares with students who have special needs. (YDS)
H infinity controller design to a rigid-flexible satellite with two vibration modes

International Nuclear Information System (INIS)

De Souza, A G; De Souza, L C G

2015-01-01

The satellite attitude control system (ACS) design becomes more complex when the satellite structure has components like, flexible solar panels, antennas and mechanical manipulators. These flexible structures can interact with the satellite rigid parts during translational and/or rotational manoeuvre damaging the ACS pointing accuracy. Although, a well-designed controller can suppress such disturbances quickly, the controller error pointing may be limited by the minimum time necessary to suppress such disturbances thus affecting the satellite attitude acquisition. This paper deals with the rigid-flexible satellite ACS design using the H infinity method. The rigid-flexible satellite is represented by a beam connected to a central rigid hub at one end and free at the other one. The equations of motions are obtained considering small flexible deformations and the Euler-Bernoulli hypothesis. The results of the simulations have shown that the H-infinity controller was able to control the rigid motion and suppress the vibrations. (paper)

Use of beam probes for rigidity calibration of the A1900 fragment separator

Energy Technology Data Exchange (ETDEWEB)

Ginter, T.N. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Farinon, F. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Baumann, T. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Hausmann, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Kwan, E.; Naviliat Cuncic, O. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Portillo, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Rogers, A.M.; Stetson, J.; Sumithrarachchi, C. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Villari, A.C.C. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Williams, S.J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

2016-06-01

Use of a beam-based approach is presented for establishing a rigidity calibration for the A1900 fragment separator located at the National Superconducting Cyclotron Laboratory. Also presented is why an alternative approach to the rigidity calibration – using detailed field maps of individual magnetic components – is not a feasible basis for deriving an accurate calibration. The level of accuracy achieved for the rigidity calibration is ±0.1%.
Measurement of Inclusive Jet Production in Deep-Inelastic Scattering at High Q$^{2}$ and Determination of the Strong Coupling

CERN Document Server

Aktas, A.; Andreev, V.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cantun Avila, K.B.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J.G.; Coughlan, J.A.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Daum, K.; Deak, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkiewicz, A.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Gayler, J.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Grell, B.R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Heinzelmann, G.; Helebrant, C.; Henderson, R.C.W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Jacquet, M.; Janssen, M.E.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, Andreas Werner; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knutsson, A.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martisikova, M.; Martyn, H.-U.; Maxfield, S.J.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G.D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Placakyte, R.; Polifka, R.; Povh, B.; Preda, T.; Prideaux, P.; Radescu, V.; Rahmat, A.J.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R.N.; Sheviakov, I.; Shtarkov, L.N.; Sloan, T.; Smiljanic, Ivan; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Staykova, Z.; Steder, M.; Stella, B.; Stiewe, J.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P.D.; Toll, T.; Tomasz, F.; Tran, T.H.; Traynor, D.; Trinh, T.N.; Truol, P.; Tsakov, I.; Tseepeldorj, B.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Utkin, D.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wissing, Ch.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y.C.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

2007-01-01

Inclusive jet production is studied in neutral current deep-inelastic positron-proton scattering at large four momentum transfer squared Q^2>150 GeV^2 with the H1 detector at HERA. Single and double differential inclusive jet cross sections are measured as a function of Q^2 and of the transverse energy E_T of the jets in the Breit frame. The measurements are found to be well described by calculations at next-to-leading order in perturbative QCD. The running of the strong coupling is demonstrated and the value of alpha_s(M_Z) is determined. The ratio of the inclusive jet cross section to the inclusive neutral current cross section is also measured and used to extract a precise value for alpha_s(M_Z)=0.1193+/-0.0014(exp.)^{+0.0047}_{-0.0030}(th.)+/-0.0016(pdf).
Non-rigid connector: The wand to allay the stresses on abutment

OpenAIRE

Banerjee, Saurav; Khongshei, Arlingstone; Gupta, Tapas; Banerjee, Ardhendu

2011-01-01

The use of rigid connectors in 5-unit fixed dental prosthesis with a pier abutment can result in failure of weaker retainer in the long run as the pier abutment acts as a fulcrum. Non-rigid connector placed on the distal aspect of pier seems to reduce potentially excess stress concentration on the pier abutment.
Confronting New Demands : Inclusive Growth, Inclusive Trade ...

International Development Research Centre (IDRC) Digital Library (Canada)

Confronting New Demands : Inclusive Growth, Inclusive Trade. Policymakers, businesspeople and civil society advocates need evidence-based research to react ... understood implications, such as labour standards and intellectual property; ...
Rigid particle revisited: Extrinsic curvature yields the Dirac equation

Energy Technology Data Exchange (ETDEWEB)

Deriglazov, Alexei, E-mail: alexei.deriglazov@ufjf.edu.br [Depto. de Matemática, ICE, Universidade Federal de Juiz de Fora, MG (Brazil); Laboratory of Mathematical Physics, Tomsk Polytechnic University, 634050 Tomsk, Lenin Ave. 30 (Russian Federation); Nersessian, Armen, E-mail: arnerses@ysu.am [Yerevan State University, 1 Alex Manoogian St., Yerevan 0025 (Armenia); Laboratory of Mathematical Physics, Tomsk Polytechnic University, 634050 Tomsk, Lenin Ave. 30 (Russian Federation)

2014-03-01

We reexamine the model of relativistic particle with higher-derivative linear term on the first extrinsic curvature (rigidity). The passage from classical to quantum theory requires a number of rather unexpected steps which we report here. We found that, contrary to common opinion, quantization of the model in terms of so(3.2)-algebra yields massive Dirac equation. -- Highlights: •New way of canonical quantization of relativistic rigid particle is proposed. •Quantization made in terms of so(3.2) angular momentum algebra. •Quantization yields massive Dirac equation.
Topology-Preserving Rigid Transformation of 2D Digital Images.

Science.gov (United States)

Ngo, Phuc; Passat, Nicolas; Kenmochi, Yukiko; Talbot, Hugues

2014-02-01

We provide conditions under which 2D digital images preserve their topological properties under rigid transformations. We consider the two most common digital topology models, namely dual adjacency and well-composedness. This paper leads to the proposal of optimal preprocessing strategies that ensure the topological invariance of images under arbitrary rigid transformations. These results and methods are proved to be valid for various kinds of images (binary, gray-level, label), thus providing generic and efficient tools, which can be used in particular in the context of image registration and warping.
Developing a financial inclusion index and inclusive growth in India

OpenAIRE

Susanta Kumar SETHY

2016-01-01

Financial inclusion is one of the systems through which Inclusive Growth can be achieved in developing countries like India where large sections are unable or hopeless to contribute in the financial system. An inclusive financial system mobilizes more resources for productive purposes leading to higher economic growth, better opportunities and reduction of poverty. This study, proposed an Index of financial inclusion – a multidimensional measure. The Financial Inclusion Index c...
Applications of square-related theorems

Science.gov (United States)

Srinivasan, V. K.

2014-04-01

The square centre of a given square is the point of intersection of its two diagonals. When two squares of different side lengths share the same square centre, there are in general four diagonals that go through the same square centre. The Two Squares Theorem developed in this paper summarizes some nice theoretical conclusions that can be obtained when two squares of different side lengths share the same square centre. These results provide the theoretical basis for two of the constructions given in the book of H.S. Hall and F.H. Stevens , 'A Shorter School Geometry, Part 1, Metric Edition'. In page 134 of this book, the authors present, in exercise 4, a practical construction which leads to a verification of the Pythagorean theorem. Subsequently in Theorems 29 and 30, the authors present the standard proofs of the Pythagorean theorem and its converse. In page 140, the authors present, in exercise 15, what amounts to a geometric construction, whose verification involves a simple algebraic identity. Both the constructions are of great importance and can be replicated by using the standard equipment provided in a 'geometry toolbox' carried by students in high schools. The author hopes that the results proved in this paper, in conjunction with the two constructions from the above-mentioned book, would provide high school students an appreciation of the celebrated theorem of Pythagoras. The diagrams that accompany this document are based on the free software GeoGebra. The author formally acknowledges his indebtedness to the creators of this free software at the end of this document.
Impact of Macroeconomic Policies on Poverty and Unemployment Rates in Nigeria, Implications for Attaining Inclusive Growth

Directory of Open Access Journals (Sweden)

Philip Nwosa

2016-04-01

Full Text Available This paper examined the effect of macroeconomic policies on unemployment and poverty rates in Nigeria from 1980 to 2013 with implication to achieving inclusive growth. The inability of macroeconomic policies in addressing the rising issues unemployment and poverty rates in Nigeria despite the impressive economic growth experience over the last decades has increasingly called for the need for the pursuance of inclusive growth to address the social issues of unemployment and poverty rate. Previous studies have not considered the extent to which macroeconomic policies affects unemployment and poverty rate in Nigeria, and the implication of this relationship to the attainment of inclusive growth in Nigeria. The study adopts the Ordinary Least Square (OLS technique. The study observed that among macroeconomic policy variables only exchange rate significantly influenced unemployment rate while only fiscal policy significantly influenced and poverty rate. This implies that present macroeconomic policies in Nigeria do not guarantee the attainment of inclusive growth in Nigeria. The contribution of the paper is that to achieve inclusive growth that guarantees high employment and reduced poverty rate, there is the need for a re-examination of macroeconomic policy management in Nigeria.
Emotional rigidity negatively impacts remission from anxiety and recovery of well-being.

Science.gov (United States)

Wiltgen, Anika; Shepard, Christopher; Smith, Ryan; Fowler, J Christopher

2018-08-15

Emotional rigidity is described in clinical literature as a significant barrier to recovery; however, few there are few empirical measures of the construct. The current study had two aims: Study 1 aimed to identify latent factors that may bear on the construct of emotional rigidity while Study 2 assessed the potential impact of the latent factor(s) on anxiety remission rates and well-being. This study utilized data from 2472 adult inpatients (1176 females and 1296 males) with severe psychopathology. Study 1 utilized exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to identify latent factors of emotional rigidity. Study 2 utilized hierarchical logistic regression analyses to assess the relationships among emotional rigidity factors and anxiety remission and well-being recovery at discharge. Study 1 yielded a two-factor solution identified in EFA was confirmed with CFA. Factor 1 consisted of neuroticism, experiential avoidance, non-acceptance of emotions, impaired goal-directed behavior, impulse control difficulties and limited access to emotion regulation strategies when experiencing negative emotions. Factor 2 consisted of lack of emotional awareness and lack of emotional clarity when experiencing negative emotions. Results of Study 2 indicated higher scores on Factor 1 was associated with lower remission rates from anxiety and poorer well-being upon discharge. Factor 2 was not predictive of outcome. Emotional rigidity appears to be a latent construct that negatively impacts remission rates from anxiety. Limitations of the present study include its retrospective design, and inefficient methods of assessing emotional rigidity. Copyright © 2018. Published by Elsevier B.V.
Modeling the Flexural Rigidity of Rod Photoreceptors

Science.gov (United States)

Haeri, Mohammad; Knox, Barry E.; Ahmadi, Aphrodite

2013-01-01

In vertebrate eyes, the rod photoreceptor has a modified cilium with an extended cylindrical structure specialized for phototransduction called the outer segment (OS). The OS has numerous stacked membrane disks and can bend or break when subjected to mechanical forces. The OS exhibits axial structural variation, with extended bands composed of a few hundred membrane disks whose thickness is diurnally modulated. Using high-resolution confocal microscopy, we have observed OS flexing and disruption in live transgenic Xenopus rods. Based on the experimental observations, we introduce a coarse-grained model of OS mechanical rigidity using elasticity theory, representing the axial OS banding explicitly via a spring-bead model. We calculate a bending stiffness of ∼105 nN⋅μm2, which is seven orders-of-magnitude larger than that of typical cilia and flagella. This bending stiffness has a quadratic relation to OS radius, so that thinner OS have lower fragility. Furthermore, we find that increasing the spatial frequency of axial OS banding decreases OS rigidity, reducing its fragility. Moreover, the model predicts a tendency for OS to break in bands with higher spring number density, analogous to the experimental observation that transgenic rods tended to break preferentially in bands of high fluorescence. We discuss how pathological alterations of disk membrane properties by mutant proteins may lead to increased OS rigidity and thus increased breakage, ultimately contributing to retinal degeneration. PMID:23442852
Psychological Prices and Price Rigidity in Grocery Retailing: Analysis of German Scanner Data

OpenAIRE

Herrmann, Roland; Moeser, Anke

2005-01-01

A substantial degree of price rigidity has been reported for branded foods in various studies with scanner data. One possible explanation for price rigidity is the existence of psychological pricing points. We analyze to which extent psychological pricing plays a role in grocery retailing and whether it contributes to price rigidity of branded foods in Germany. Psychological pricing defined here as just-below-the-round-figure-pricing is empirically analyzed with scanner data of weekly prices ...
A viscoplastic strain gradient analysis of materials with voids or inclusions

DEFF Research Database (Denmark)

Borg, Ulrik; Niordson, Christian Frithiof; Fleck, N. A.

2006-01-01

-2454] of the strain gradient plasticity theory proposed by Fleck and Hutchinson (2001) [Journal of the Mechanics and Physics of Solids 49, 2245-2271]. The formulation is based on a viscoplastic potential that enables the formulation of the model so that it reduces to the strain gradient plasticity theory...... in the absence of viscous effects. The numerical implementation uses increments of the effective plastic strain rate as degrees of freedom in addition to increments of displacement. To illustrate predictions of the model, results are presented for materials containing either voids or rigid inclusions......A finite strain viscoplastic nonlocal plasticity model is formulated and implemented numerically within a finite element framework. The model is a viscoplastic generalisation of the finite strain generalisation by Niordson and Redanz (2004) [Journal of the Mechanics and Physics of Solids 52, 2431...
Graphs whose complement and square are isomorphic

DEFF Research Database (Denmark)

Pedersen, Anders Sune

2014-01-01

We study square-complementary graphs, that is, graphs whose complement and square are isomorphic. We prove several necessary conditions for a graph to be square-complementary, describe ways of building new square-complementary graphs from existing ones, construct infinite families of square-compl...
GENERAL THEORY OF THE ROTATION OF THE NON-RIGID EARTH AT THE SECOND ORDER. I. THE RIGID MODEL IN ANDOYER VARIABLES

International Nuclear Information System (INIS)

Getino, J.; Miguel, D.; Escapa, A.

2010-01-01

This paper is the first part of an investigation where we will present an analytical general theory of the rotation of the non-rigid Earth at the second order, which considers the effects of the interaction of the rotation of the Earth with itself, also named as the spin-spin coupling. Here, and as a necessary step in the development of that theory, we derive complete, explicit, analytical formulae of the rigid Earth rotation that account for the second-order rotation-rotation interaction. These expressions are not provided in this form by any current rigid Earth model. Working within the Hamiltonian framework established by Kinoshita, we study the second-order effects arising from the interaction of the main term in the Earth geopotential expansion with itself, and with the complementary term arising when referring the rotational motion to the moving ecliptic. To this aim, we apply a canonical perturbation method to solve analytically the canonical equations at the second order, determining the expressions that provide the nutation-precession, the polar motion, and the length of day. In the case of the motion of the equatorial plane, nutation-precession, we compare our general approach with the particular study for this motion developed by Souchay et al., showing the existence of new terms whose numerical values are within the truncation level of 0.1 μas adopted by those authors. These terms emerge as a consequence of not assuming in this work the same restrictive simplifications taken by Souchay et al. The importance of these additional contributions is that, as the analytical formulae show, they depend on the Earth model considered, in such a way that the fluid core resonance could amplify them significatively when extending this theory to the non-rigid Earth models.
Green waste cooking oil-based rigid polyurethane foam

Science.gov (United States)

Enderus, N. F.; Tahir, S. M.

2017-11-01

Polyurethane is a versatile polymer traditionally prepared using petroleum-based raw material. Petroleum, however, is a non-renewable material and polyurethane produced was found to be non-biodegradable. In quest for a more environmentally friendly alternative, wastecooking oil, a highly abundant domestic waste with easily derivatized structure, is a viable candidate to replace petroleum. In this study,an investigation to determine physical and chemical properties of rigid polyurethane (PU) foam from waste cooking oil (WCO) was carried out. WCO was first adsorbed by using coconut husk activated carbon adsorbent prior to be used for polyol synthesis. The purified WCO was then used to synthesize polyol via transesterification reaction to yield alcohol groups in the WCO chains structure. Finally, the WCO-based polyol was used to prepare rigid PU foam. The optimum formulation for PU formation was found to be 90 polyol: 60 glycerol: 54 water: 40 diethanolamine: 23 diisocyanate. The rigid PU foam has density of 208.4 kg/m3 with maximum compressive strength and capability to receive load at 0.03 MPa and 0.09 kN, respectively. WCO-based PU can potentially be used to replace petroleum-based PU as house construction materials such as insulation panels.
Almost-global tracking for a rigid body with internal rotors

OpenAIRE

Nayak, Aradhana; Banavar, Ravi N.

2017-01-01

Almost-global orientation trajectory tracking for a rigid body with external actuation has been well studied in the literature, and in the geometric setting as well. The tracking control law relies on the fact that a rigid body is a simple mechanical system (SMS) on the $3-$dimensional group of special orthogonal matrices. However, the problem of designing feedback control laws for tracking using internal actuation mechanisms, like rotors or control moment gyros, has received lesser attention...
Mitral stenosis due to pannus overgrowth after rigid ring annuloplasty.

Science.gov (United States)

Oda, Takeshi; Kato, Seiya; Tayama, Eiki; Fukunaga, Shuji; Akashi, Hidetoshi; Aoyagi, Shigeaki

2010-03-01

Although mitral stenosis (MS) due to pannus overgrowth after mitral valve repair for rheumatic mitral regurgitation (MR) is not uncommon, it is extremely rare in relation to non-rheumatic mitral regurgitation. Whilst it has been suggested that the rigid annuloplasty ring induces pannus overgrowth in the same manner as the flexible ring, to date only in cases using the flexible ring has pannus formation been confirmed by a pathological examination after redo surgery. The case is described of a woman who had undergone mitral valve repair using a 28 mm rigid ring three years previously because of non-rheumatic MR, and subsequently suffered from MS due to pannus formation over the annuloplasty ring. To the present authors' knowledge, this is the first report of MS due to pannus formation after mitral valve repair using a rigid annuloplasty ring to treat non-rheumatic MR documented at reoperation.
Authoritarianism, cognitive rigidity, and the processing of ambiguous visual information.

Science.gov (United States)

Duncan, Lauren E; Peterson, Bill E

2014-01-01

Intolerance of ambiguity and cognitive rigidity are unifying aspects of authoritarianism as defined by Adorno, Frenkel-Brunswik, Levinson, and Sanford (1982/1950), who hypothesized that authoritarians view the world in absolute terms (e.g., good or evil). Past studies have documented the relationship between authoritarianism and intolerance of ambiguity and rigidity. Frenkel-Brunswik (1949) hypothesized that this desire for absolutism was rooted in perceptual processes. We present a study with three samples that directly tests the relationship between right wing authoritarianism (RWA) and the processing of ideologically neutral but ambiguous visual stimuli. As hypothesized, in all three samples we found that RWA was related to the slower processing of visual information that required participants to recategorize objects. In a fourth sample, RWA was unrelated to speed of processing visual information that did not require recategorization. Overall, results suggest a relationship between RWA and rigidity in categorization.
Three-dimensional formulation of rigid-flexible multibody systems with flexible beam elements

International Nuclear Information System (INIS)

Garcia-Vallejo, D.; Mayo, J.; Escalona, J. L.; Dominguez, J.

2008-01-01

Multibody systems generally contain solids with appreciable deformations and which decisively influence the dynamics of the system. These solids have to be modeled by means of special formulations for flexible solids. At the same time, other solids are of such a high stiffness that they may be considered rigid, which simplifies their modeling. For these reasons, for a rigid-flexible multibody system, two types of formulations coexist in the equations of the system. Among the different possibilities provided in the literature on the material, the formulation in natural coordinates and the formulation in absolute nodal coordinates are utilized in this paper to model the rigid and flexible solids, respectively. This paper contains a mixed formulation based on the possibility of sharing coordinates between a rigid solid and a flexible solid. The global mass matrix of the system is shown to be constant and, in addition, many of the constraint equations obtained upon utilizing these formulations are linear and can be eliminated

Self-diffusion of particles interacting through a square-well or square-shoulder potential

NARCIS (Netherlands)

Wilbertz, H.; Michels, J.; Beijeren, H. van; Leegwater, J.A.

1988-01-01

The diffusion coefficient and velocity autocorrelation function for a fluid of particles interacting through a square-well or square-shoulder potential are calculated from a kinetic theory similar to the Davis-Rice-Sengers theory and the results are compared to those of computer simulations. At low
Extremal surfaces and the rigidity of null geodesic incompleteness

International Nuclear Information System (INIS)

Silva, I P Costa e; Flores, J L

2015-01-01

An important, if relatively less well known aspect of the singularity theorems in Lorentzian geometry, is to understand how their conclusions fare upon weakening or suppression of one or more of their hypotheses. Then, theorems with modified conclusion may arise, showing that those conclusions will fail only in special cases, at least some of which may be described. These are the so-called rigidity theorems, and have many important examples in the specialized literature. In this paper, we prove rigidity results for generalized plane waves and certain globally hyperbolic spacetimes in the presence of extremal compact surfaces. (paper)
XAFS study of copper(II) complexes with square planar and square pyramidal coordination geometries

Science.gov (United States)

Gaur, A.; Klysubun, W.; Nitin Nair, N.; Shrivastava, B. D.; Prasad, J.; Srivastava, K.

2016-08-01

X-ray absorption fine structure of six Cu(II) complexes, Cu2(Clna)4 2H2O (1), Cu2(ac)4 2H2O (2), Cu2(phac)4 (pyz) (3), Cu2(bpy)2(na)2 H2O (ClO4) (4), Cu2(teen)4(OH)2(ClO4)2 (5) and Cu2(tmen)4(OH)2(ClO4)2 (6) (where ac, phac, pyz, bpy, na, teen, tmen = acetate, phenyl acetate, pyrazole, bipyridine, nicotinic acid, tetraethyethylenediamine, tetramethylethylenediamine, respectively), which were supposed to have square pyramidal and square planar coordination geometries have been investigated. The differences observed in the X-ray absorption near edge structure (XANES) features of the standard compounds having four, five and six coordination geometry points towards presence of square planar and square pyramidal geometry around Cu centre in the studied complexes. The presence of intense pre-edge feature in the spectra of four complexes, 1-4, indicates square pyramidal coordination. Another important XANES feature, present in complexes 5 and 6, is prominent shoulder in the rising part of edge whose intensity decreases in the presence of axial ligands and thus indicates four coordination in these complexes. Ab initio calculations were carried out for square planar and square pyramidal Cu centres to observe the variation of 4p density of states in the presence and absence of axial ligands. To determine the number and distance of scattering atoms around Cu centre in the complexes, EXAFS analysis has been done using the paths obtained from Cu(II) oxide model and an axial Cu-O path from model of a square pyramidal complex. The results obtained from EXAFS analysis have been reported which confirmed the inference drawn from XANES features. Thus, it has been shown that these paths from model of a standard compound can be used to determine the structural parameters for complexes having unknown structure.
Risk of perforation using rigid oesophagoscopy in the distal part of oesophagus

DEFF Research Database (Denmark)

Wennervaldt, Kasper; Melchiors, Jacob

2012-01-01

Endoscopic examination and treatment of disorders in the oesophagus have been a part of the otolaryngological specialty since the introduction of the rigid endoscope. Today, both flexible and rigid oesophagoscopy (RO) is used to that end. The aim of this study was to evaluate the safety of the RO....
On the rigidity of rank gradient in a group of intermediate growth

OpenAIRE

Grigorchuk, Rostislav; Kravchenko, Rostyslav

2018-01-01

We introduce and investigate the rigidity property of rank gradient in the case of the group $\\mathcal G$ of intermediate growth constructed by the first author. We show that $\\mathcal G$ is normally $(f,g)$-RG rigid where $f(n)=\\log(n)$ and $g(n) =\\log(\\log(n)).$
A study of semi-rigid support on ankle supination sprain kinematics.

Science.gov (United States)

Tang, Y M; Wu, Z H; Liao, W H; Chan, K M

2010-12-01

Ankle sprain injury is very common in sports and the use of ankle support is crucial. This research investigated the effect of an ankle brace in reducing the ankle angular displacement and angular velocity during sudden supination. In the experiment, 11 healthy males were tested. The bracing condition, semi-rigid ankle braces were investigated. The angular displacement and angular velocity of the ankle were computed. The motion-capture system was adopted to capture the three-dimensional coordinates of the reflective markers. The coordinates of the reflective markers were used to compute the ankle kinematics during simulated ankle supination. A mechanical supination platform was used to simulate the sprain motions. Experimental results showed that the semi-rigid brace tested significantly reduced the ankle angular displacement and angular velocity compared with control conditions during sudden supination. In conclusion, the semi-rigid-type brace can provide significant restriction to reduce the magnitudes of the angular displacement and angular velocity of the ankle during sudden supination sprain. The semi-rigid-type brace is suggested as the prophylactic bracing for the ankle. © 2009 John Wiley & Sons A/S.
Diffusion-accomodated rigid-body translations along grain boundaries in nanostructured materials

International Nuclear Information System (INIS)

Bachurin, D.V.; Nazarov, A.A.; Shenderova, O.A.; Brenner, D.W.

2003-01-01

A model for the structural relaxation of grain boundaries (GBs) in nanostructured materials (NSMs) by diffusion-accommodated rigid body translations along GBs is proposed. The model is based on the results of recent computer simulations that have demonstrated that the GBs in NSMs retain a high-energy structure with random translational states due to severe geometrical constraints applied from neighboring grains (J. Appl. Phys. 78 (1995) 847; Scripta Metall. Mater. 33 (1995) 1245). The shear stresses within a GB caused by non-optimized rigid-body translations (RBTs) can be accommodated by diffusive flow of atoms along a GB. This mechanism is particularly important for low-angle and vicinal GBs, the energy of which noticeably depends on the rigid body translations. At moderate and high temperatures the model yields relaxation times that are very short and therefore GBs in NSMs can attain an equilibrium structure with optimized rigid body translations. In contrast, at room temperature the model predicts that in some metals non-equilibrium structures can be preserved for a long time, which may result in the observation of grain boundary structures different from those in coarse grained polycrystals
Calculations of critical micelle concentration by dissipative particle dynamics simulations: the role of chain rigidity.

Science.gov (United States)

Lee, Ming-Tsung; Vishnyakov, Aleksey; Neimark, Alexander V

2013-09-05

Micelle formation in surfactant solutions is a self-assembly process governed by complex interplay of solvent-mediated interactions between hydrophilic and hydrophobic groups, which are commonly called heads and tails. However, the head-tail repulsion is not the only factor affecting the micelle formation. For the first time, we present a systematic study of the effect of chain rigidity on critical micelle concentration and micelle size, which is performed with the dissipative particle dynamics simulation method. Rigidity of the coarse-grained surfactant molecule was controlled by the harmonic bonds set between the second-neighbor beads. Compared to flexible molecules with the nearest-neighbor bonds being the only type of bonded interactions, rigid molecules exhibited a lower critical micelle concentration and formed larger and better-defined micelles. By varying the strength of head-tail repulsion and the chain rigidity, we constructed two-dimensional diagrams presenting how the critical micelle concentration and aggregation number depend on these parameters. We found that the solutions of flexible and rigid molecules that exhibited approximately the same critical micelle concentration could differ substantially in the micelle size and shape depending on the chain rigidity. With the increase of surfactant concentration, primary micelles of more rigid molecules were found less keen to agglomeration and formation of nonspherical aggregates characteristic of flexible molecules.
Rigidity spectrum of Forbush decrease calculated by neutron monitors data corrected and uncorrected for geomagnetic disturbances

International Nuclear Information System (INIS)

Alania, M V; Wawrzynczak, A; Sdobnov, V E; Kravtsova, M V

2013-01-01

Forbush decreases (Fd) of the galactic cosmic ray (GCR) intensity and geomagnetic storms are observed almost at the same time. Geomagnetic storm is a reason of significant disturbances of the magnetic cut off rigidity causing the distortion of the time profile of the Fd of the GCR intensity. We show some differences in the temporal changes of the rigidity spectra of Fd calculated by neutron monitors experimental data corrected and uncorrected for the changes of the geomagnetic cut off rigidity. Nevertheless, the general features of the temporal changes of the rigidity spectrum of Fd maintain as it was found in our previous investigations. Namely, at the beginning phase of Fd rigidity spectrum is relatively soft and gradually becomes hard up to reaching the minimum level of the GCR intensity; then the rigidity spectrum gradually becomes soft during the recovery phase of Fd. We also confirm that for the established temporal profiles of the rigidity spectrum of Fd a structural changes of the interplanetary magnetic field turbulence in the range of frequencies, 10 −-6 ÷10 −-5 Hz are responsible.
Dynamic Multi-Rigid-Body Systems with Concurrent Distributed Contacts: Theory and Examples

International Nuclear Information System (INIS)

TRINKLE, JEFFREY C.; TZITZOURIS, J.A.; PANG, J.S.

2001-01-01

Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigid-body contact problem is to predict the accelerations of the bodies and the normal friction loads acting at the contacts. This paper presents theoretical results for the multi-rigid-body contact problem under the assumptions that one or more contacts occur over locally planar, finite regions and that friction forces are consistent with the maximum work inequality. Existence and uniqueness results are presented for this problem under mild assumptions on the system inputs. In addition, the performance of two different time-stepping methods for integrating the dynamics are compared on two simple multi-body systems
Fluctuations and rigidities in local labor markets. Part 2: reinterpreting contracts

OpenAIRE

G L Clark

1983-01-01

Local labor markets are characterized by rigidities in their patterns of adjustment to short-run fluctuations. With or without unions, fluctuations in employment, hours worked, and money wages are unlike the patterns predicted by conventional discrete-exchange labor-market theories. Moreover there are distinct geographical and industrial patterns in the observed rigidities. Neoclassical implicit contract theory has been vindicated. Or has it? Obvious empirical difficulties remain, especially ...
Truncated exponential-rigid-rotor model for strong electron and ion rings

International Nuclear Information System (INIS)

Larrabee, D.A.; Lovelace, R.V.; Fleischmann, H.H.

1979-01-01

A comprehensive study of exponential-rigid-rotor equilibria for strong electron and ion rings indicates the presence of a sizeable percentage of untrapped particles in all equilibria with aspect-ratios R/a approximately <4. Such aspect-ratios are required in fusion-relevant rings. Significant changes in the equilibria are observed when untrapped particles are excluded by the use of a truncated exponential-rigid-rotor distribution function. (author)
Rigid body displacement fields of an in-plane-deformable curved beam based on conventional strain definition

International Nuclear Information System (INIS)

Moon, Won Joo; Min, Oak Key; Kim, Yong Woo

1998-01-01

To improve the convergence and the accuracy of a finite element, the finite element has to describe not only displacement and stress distributions in a static analysis but also rigid body displacements. In this paper, we consider the in-plane-deformable curved beam element to understand the descriptive capability of rigid body displacements of a finite element. We derive the rigid body displacement fields of a single finite element under various essential boundary conditions when the nodal displacements are caused by the rigid body displacement. We also examine the rigid body displacement fields of a quadratic curved beam element by employing the reduced minimization theory
Pediatric mandibular fractures treated by rigid internal fixation.

Science.gov (United States)

Wong, G B

1993-09-01

Mandibular fractures in the pediatric patient population are relatively uncommon. These patients present with their own unique treatment requirements. Most fractures have been treated conservatively by dental splints. Closed reduction techniques with maxillomandibular fixation (MMF) in very young children can pose several concerns, including cooperation, compliance and adequate nutritional intake. Rigid internal fixation of unstable mandibular fractures using miniplates and screws circumvents the need for MMF and allows immediate jaw mobilization. At major pediatric trauma institutions, there has been an increasing trend toward the use of this treatment when open reduction is necessary. This article presents a report of a five-year-old child who presented with bilateral mandibular fractures and was treated by rigid internal fixation and immediate mandibular mobilization.
Rigidity of complete noncompact bach-flat n-manifolds

Science.gov (United States)

Chu, Yawei; Feng, Pinghua

2012-11-01

Let (Mn,g) be a complete noncompact Bach-flat n-manifold with the positive Yamabe constant and constant scalar curvature. Assume that the L2-norm of the trace-free Riemannian curvature tensor R∘m is finite. In this paper, we prove that (Mn,g) is a constant curvature space if the L-norm of R∘m is sufficiently small. Moreover, we get a gap theorem for (Mn,g) with positive scalar curvature. This can be viewed as a generalization of our earlier results of 4-dimensional Bach-flat manifolds with constant scalar curvature R≥0 [Y.W. Chu, A rigidity theorem for complete noncompact Bach-flat manifolds, J. Geom. Phys. 61 (2011) 516-521]. Furthermore, when n>9, we derive a rigidity result for R<0.
Stresses in Circular Plates with Rigid Elements

Science.gov (United States)

Velikanov, N. L.; Koryagin, S. I.; Sharkov, O. V.

2018-05-01

Calculations of residual stress fields are carried out by numerical and static methods, using the flat cross-section hypothesis. The failure of metal when exposed to residual stresses is, in most cases, brittle. The presence in the engineering structures of rigid elements often leads to the crack initiation and structure failure. This is due to the fact that rigid elements under the influence of external stresses are stress concentrators. In addition, if these elements are fixed by welding, the residual welding stresses can lead to an increase in stress concentration and, ultimately, to failure. The development of design schemes for such structures is a very urgent task for complex technical systems. To determine the stresses in a circular plate with a welded circular rigid insert under the influence of an external load, one can use the solution of the plane stress problem for annular plates in polar coordinates. The polar coordinates of the points are the polar radius and the polar angle, and the stress state is determined by normal radial stresses, tangential and shearing stresses. The use of the above mentioned design schemes, formulas, will allow more accurate determination of residual stresses in annular welded structures. This will help to establish the most likely directions of failure and take measures at the stages of designing, manufacturing and repairing engineering structures to prevent these failures. However, it must be taken into account that the external load, the presence of insulation can lead to a change in the residual stress field.
Resin Infusion Rigidized Inflatable Concept Development and Demonstration

Data.gov (United States)

National Aeronautics and Space Administration — A novel concept utilizing resin infusion to rigidize inflatable structures was developed at JSC ES. This ICA project intends to complete manufacturing of a prototype...
A concise introduction to mechanics of rigid bodies multidisciplinary engineering

CERN Document Server

Huang, L

2017-01-01

This updated second edition broadens the explanation of rotational kinematics and dynamics — the most important aspect of rigid body motion in three-dimensional space and a topic of much greater complexity than linear motion. It expands treatment of vector and matrix, and includes quaternion operations to describe and analyze rigid body motion which are found in robot control, trajectory planning, 3D vision system calibration, and hand-eye coordination of robots in assembly work, etc. It features updated treatments of concepts in all chapters and case studies. The textbook retains its comprehensiveness in coverage and compactness in size, which make it easily accessible to the readers from multidisciplinary areas who want to grasp the key concepts of rigid body mechanics which are usually scattered in multiple volumes of traditional textbooks. Theoretical concepts are explained through examples taken from across engineering disciplines and links to applications and more advanced courses (e.g. industrial rob...
Heat Transfer Measurement and Modeling in Rigid High-Temperature Reusable Surface Insulation Tiles

Science.gov (United States)

Daryabeigi, Kamran; Knutson, Jeffrey R.; Cunnington, George R.

2011-01-01

Heat transfer in rigid reusable surface insulations was investigated. Steady-state thermal conductivity measurements in a vacuum were used to determine the combined contribution of radiation and solid conduction components of heat transfer. Thermal conductivity measurements at higher pressures were then used to estimate the effective insulation characteristic length for gas conduction modeling. The thermal conductivity of the insulation can then be estimated at any temperature and pressure in any gaseous media. The methodology was validated by comparing estimated thermal conductivities with published data on a rigid high-temperature silica reusable surface insulation tile. The methodology was also applied to the alumina enhanced thermal barrier tiles. Thermal contact resistance for thermal conductivity measurements on rigid tiles was also investigated. A technique was developed to effectively eliminate thermal contact resistance on the rigid tile s cold-side surface for the thermal conductivity measurements.
Molecular modeling of proteinlike inclusions in lipid bilayers: lipid-mediated interactions.

Science.gov (United States)

Kik, Richard A; Leermakers, Frans A M; Kleijn, J Mieke

2010-02-01

We investigated the insertion of transmembrane structures in a lipid bilayer and their interactions using self-consistent field theory. The lipids are coarse-grained on a united-atom level and consist of a phosphatidylcholinelike headgroup and two hydrophobic tails. The inclusions, acting as simple models for proteins that span biological membranes, are rigid rods (radius R ) with a hydrophobic surface and hydrophilic end caps. The insertion free energy Omega of an individual rod is strongly regulated by the affinity between its hydrophobic surface and the lipid tails. This affinity also controls the best match of the hydrophobic length of the rod with that of the bilayer. The line tension tau(=Omega/2piR) is practically independent of R . The perturbations in the bilayer as a function of distance from the inclusion, have the shape of a damped oscillation. The wavelength and decay length are related to the elastic properties of the bilayer and do not depend on R . These results are used to analyze how the lipid matrix affects the interaction between transmembrane objects, for computational reasons considering the limit of R-->infinity . Contributions on different length scales can be distinguished: (i) a long-range elastic interaction, which is an exponentially decaying oscillation; (ii) an exponentially decaying repulsion on an intermediate length scale, resulting from the loss of conformational entropy of the lipid tails; and (iii) a short-range interaction due to the finite compressibility of the lipid tails, which manifests either as a depletion attraction if there is no affinity between the tails and the inclusions' surface or, otherwise, as an oscillatory structural force.

A rigidity transition and glassy dynamics in a model for confluent 3D tissues

Science.gov (United States)

Merkel, Matthias; Manning, M. Lisa

The origin of rigidity in disordered materials is an outstanding open problem in statistical physics. Recently, a new type of rigidity transition was discovered in a family of models for 2D biological tissues, but the mechanisms responsible for rigidity remain unclear. This is not just a statistical physics problem, but also relevant for embryonic development, cancer growth, and wound healing. To gain insight into this rigidity transition and make new predictions about biological bulk tissues, we have developed a fully 3D self-propelled Voronoi (SPV) model. The model takes into account shape, elasticity, and self-propelled motion of the individual cells. We find that in the absence of self-propulsion, this model exhibits a rigidity transition that is controlled by a dimensionless model parameter describing the preferred cell shape, with an accompanying structural order parameter. In the presence of self-propulsion, the rigidity transition appears as a glass-like transition featuring caging and aging effects. Given the similarities between this transition and jamming in particulate solids, it is natural to ask if the two transitions are related. By comparing statistics of Voronoi geometries, we show the transitions are surprisingly close but demonstrably distinct. Furthermore, an index theorem used to identify topologically protected mechanical modes in jammed systems can be extended to these vertex-type models. In our model, residual stresses govern the transition and enter the index theorem in a different way compared to jammed particles, suggesting the origin of rigidity may be different between the two.
Chiral Orientation of Skeletal Muscle Cells Requires Rigid Substrate

Directory of Open Access Journals (Sweden)

Ninghao Zhu

2017-06-01

Full Text Available Reconstitution of tissue morphology with inherent left–right (LR asymmetry is essential for tissue/organ functions. For skeletal muscle, the largest tissue in mammalian organisms, successful myogenesis requires the regulation of the LR asymmetry to form the appropriate muscle alignment. However, the key factor for reproducing the LR asymmetry of skeletal tissues in a controllable, engineering context remains largely unknown. Recent reports indicate that cell chirality may underlie the LR development in tissue morphogenesis. Here, we report that a rigid substrate is required for the chirality of skeletal muscle cells. By using alternating micropatterned cell-adherent and cell-repellent stripes on a rigid substrate, we found that C2C12 skeletal muscle myoblasts exhibited a unidirectional tilted orientation with respect to the stripe boundary. Importantly, such chiral orientation was reduced when soft substrates were used instead. In addition, we demonstrated the key role of actin stress fibers in the formation of the chiral orientation. This study reveals that a rigid substrate is required for the chiral pattern of myoblasts, paving the way for reconstructing damaged muscle tissue with inherent LR asymmetry in the future.
ANALYTIC EVALUATION OF RECTILINEARITY OF LOW RIGIDITY SHAFT DURING HARDENING PROCESS

Directory of Open Access Journals (Sweden)

Antoni Świć

2013-03-01

Full Text Available The essential influence of the unevenness of temperature distribution while heating in the technological process on dimensions stability of low rigidity elements was shown. The new approach was applied to formulate mathematical models, which describe the elastic and inelastic behaviour of piece using transfer functions and block diagrams, allowing to use frequency method for evaluation of the behaviour of dynamic semi-finished element as the rigid body.
Birationally rigid varieties. I. Fano varieties

International Nuclear Information System (INIS)

Pukhlikov, A V

2007-01-01

The theory of birational rigidity of rationally connected varieties generalises the classical rationality problem. This paper gives a survey of the current state of this theory and traces its history from Noether's theorem and the Lueroth problem to the latest results on the birational superrigidity of higher-dimensional Fano varieties. The main components of the method of maximal singularities are considered.
Rigid Residue Scan Simulations Systematically Reveal Residue Entropic Roles in Protein Allostery.

Directory of Open Access Journals (Sweden)

Robert Kalescky

2016-04-01

Full Text Available Intra-protein information is transmitted over distances via allosteric processes. This ubiquitous protein process allows for protein function changes due to ligand binding events. Understanding protein allostery is essential to understanding protein functions. In this study, allostery in the second PDZ domain (PDZ2 in the human PTP1E protein is examined as model system to advance a recently developed rigid residue scan method combining with configurational entropy calculation and principal component analysis. The contributions from individual residues to whole-protein dynamics and allostery were systematically assessed via rigid body simulations of both unbound and ligand-bound states of the protein. The entropic contributions of individual residues to whole-protein dynamics were evaluated based on covariance-based correlation analysis of all simulations. The changes of overall protein entropy when individual residues being held rigid support that the rigidity/flexibility equilibrium in protein structure is governed by the La Châtelier's principle of chemical equilibrium. Key residues of PDZ2 allostery were identified with good agreement with NMR studies of the same protein bound to the same peptide. On the other hand, the change of entropic contribution from each residue upon perturbation revealed intrinsic differences among all the residues. The quasi-harmonic and principal component analyses of simulations without rigid residue perturbation showed a coherent allosteric mode from unbound and bound states, respectively. The projection of simulations with rigid residue perturbation onto coherent allosteric modes demonstrated the intrinsic shifting of ensemble distributions supporting the population-shift theory of protein allostery. Overall, the study presented here provides a robust and systematic approach to estimate the contribution of individual residue internal motion to overall protein dynamics and allostery.
Re-analysis of exponential rigid-rotor astron equilibria

International Nuclear Information System (INIS)

Lovelace, R.V.; Larrabee, D.A.; Fleischmann, H.H.

1978-01-01

Previous studies of exponential rigid-rotor astron equilibria include particles which are not trapped in the self-field of the configuration. The modification of these studies required to exclude untrapped particles is derived
Approaching Inclusion as Social Practice: Processes of Inclusion and Exclusion

DEFF Research Database (Denmark)

Molbæk, Mette; Hansen, Janne Hedegaard; Lassen, Mikkel

2018-01-01

The article presents the results of a review of international research investigating mechanisms and processes of inclusion and exclusion as an ongoing part of social practice in a school context. The review forms part of a research project investigating the social practices of inclusive education...... in primary and lower-secondary education (age 6–16) in public schools as constituted by processes of inclusion and exclusion. The project aims to shift the scientific focus of research in inclusive education from the development of pedagogical and didactic practice to the importance of community construction...... through inclusion and exclusion processes. The project arises in context of Danish education policy, while the review looked for international research findings on the limits between inclusion and exclusion: how they are drawn, by whom, for what reasons, and for whose benefit? On the background...
Effect of local perturbations of the geomagnetic field on cosmic ray cutoff rigidities at Jungfraujoch and Kiel

International Nuclear Information System (INIS)

Flueckiger, E.O.; Smart, D.F.; Shea, M.A.

1983-01-01

We have investigated the effect of local perturbations of the geomagnetic field on the vertical cosmic ray cutoff rigidities at Jungfraujoch and Kiel as representative mid-latitude neutron monitor stations. The main, effective, and Stoermer vertical cutoff rigidities and their changes were determined by utilizing the trajectory-tracing technique in a magnetic field which is modeled as a simple dipole field to which the disturbance field is superposed. It was found that the cosmic ray cutoff rigidities are most sensitive to variations of the z component of the geomagnetic field at geomagnetic latitudes -20 0 0 and at longitudes within 90 0 to the east of these northern hemisphere stations. Furthermore, cutoff rigidity variations at Kiel are predominantly due to changes of the geomagnetic field within geocentric distances 2.5R/sub E/< r<6R/sub E/, whereas at Jungfraujoch changes in cutoff rigidities are caused almost exclusively by magnetic disturbances within 1R/sub E/< r<4.5R/sub E/. For both locations the dependence of the main, effective, and Stoermer vertical cutoff rigidities on the radial, latitudinal and longitudinal structure of the magnetic perturbations is given explicitly. The results are discussed with respect to the theory by Treiman (1953) describing the effect of a ring current on cosmic ray cutoff rigidities. It is also shown that for the analysis of the characteristic properties of the correlation between cutoff rigidity variations and specific geomagnetic perturbations the rigidity corresponding to the first ''discontinuity band'' of the rigidity spectrum is an extremely useful parameter
Limits to Inclusion

Science.gov (United States)

Hansen, Janne Hedegaard

2012-01-01

In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…
Statistical Analysis of Bending Rigidity Coefficient Determined Using Fluorescence-Based Flicker-Noise Spectroscopy.

Science.gov (United States)

Doskocz, Joanna; Drabik, Dominik; Chodaczek, Grzegorz; Przybyło, Magdalena; Langner, Marek

2018-06-01

Bending rigidity coefficient describes propensity of a lipid bilayer to deform. In order to measure the parameter experimentally using flickering noise spectroscopy, the microscopic imaging is required, which necessitates the application of giant unilamellar vesicles (GUV) lipid bilayer model. The major difficulty associated with the application of the model is the statistical character of GUV population with respect to their size and the homogeneity of lipid bilayer composition, if a mixture of lipids is used. In the paper, the bending rigidity coefficient was measured using the fluorescence-enhanced flicker-noise spectroscopy. In the paper, the bending rigidity coefficient was determined for large populations of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phosphocholine vesicles. The quantity of obtained experimental data allows to perform statistical analysis aiming at the identification of the distribution, which is the most appropriate for the calculation of the value of the membrane bending rigidity coefficient. It has been demonstrated that the bending rigidity coefficient is characterized by an asymmetrical distribution, which is well approximated with the gamma distribution. Since there are no biophysical reasons for that we propose to use the difference between normal and gamma fits as a measure of the homogeneity of vesicle population. In addition, the effect of a fluorescent label and types of instrumental setups on determined values has been tested. Obtained results show that the value of the bending rigidity coefficient does not depend on the type of a fluorescent label nor on the type of microscope used.
Rigid-beam model of a high-efficiency magnicon

International Nuclear Information System (INIS)

Rees, D.E.; Tallerico, P.J.; Humphries, S.J. Jr.

1993-01-01

The magnicon is a new type of high-efficiency deflection-modulated amplifier developed at the Institute of Nuclear Physics in Novosibirsk, Russia. The prototype pulsed magnicon achieved an output power of 2.4 MW and an efficiency of 73% at 915 MHz. This paper presents the results of a rigid-beam model for a 700-MHz, 2.5-MW 82%-efficient magnicon. The rigid-beam model allows for characterization of the beam dynamics by tracking only a single electron. The magnicon design presented consists of a drive cavity; passive cavities; a pi-mode, coupled-deflection cavity; and an output cavity. It represents an optimized design. The model is fully self-consistent, and this paper presents the details of the model and calculated performance of a 2.5-MW magnicon
36 CFR 910.67 - Square guidelines.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Square guidelines. 910.67... GUIDELINES AND UNIFORM STANDARDS FOR URBAN PLANNING AND DESIGN OF DEVELOPMENT WITHIN THE PENNSYLVANIA AVENUE DEVELOPMENT AREA Glossary of Terms § 910.67 Square guidelines. Square Guidelines establish the Corporation's...
A Note on Magic Squares

Science.gov (United States)

Williams, Horace E.

1974-01-01

A method for generating 3x3 magic squares is developed. A series of questions relating to these magic squares is posed. An invesitgation using matrix methods is suggested with some questions for consideration. (LS)
Maxwell rigidity and topological constraints in amorphous phase-change networks

International Nuclear Information System (INIS)

Micoulaut, M.; Otjacques, C.; Raty, J.-Y.; Bichara, C.

2011-01-01

By analyzing first-principles molecular-dynamics simulations of different telluride amorphous networks, we develop a method for the enumeration of radial and angular topological constraints, and show that the phase diagram of the most popular system Ge-Sb-Te can be split into two compositional elastic phases: a tellurium rich flexible phase and a stressed rigid phase that contains most of the materials used in phase-change applications. This sound atomic scale insight should open new avenues for the understanding of phase-change materials and other complex amorphous materials from the viewpoint of rigidity.
Democracy Squared

DEFF Research Database (Denmark)

Rose, Jeremy; Sæbø, Øystein

2005-01-01

On-line political communities, such as the Norwegian site Demokratitorget (Democracy Square), are often designed according to a set of un-reflected assumptions about the political interests of their potential members. In political science, democracy is not taken as given in this way, but can...... be represented by different models which characterize different relationships between politicians and the citizens they represent. This paper uses quantitative and qualitative content analysis to analyze the communication mediated by the Democracy Square discussion forum in the first ten months of its life......-Republican model. In the qualitative analysis the discourse is analysed as repeating genres – patterns in the communication form which also reflect the conflict of interest between citizens and politicians. Though the analysis gives insight into the nature of the discourse the site supports, little is known about...
Oscillations of rigid bar in the special relativity

International Nuclear Information System (INIS)

Paiva, F.M.; Teixeira, A.F.F.

2011-12-01

In the special relativity, a rigid bar slides on herself, with a extreme oscillating harmonically. We have discovered at the movement amplitude and in the bar length, indispensable for the elimination of non physical solutions
A geometrically controlled rigidity transition in a model for confluent 3D tissues

Science.gov (United States)

Merkel, Matthias; Manning, M. Lisa

2018-02-01

The origin of rigidity in disordered materials is an outstanding open problem in statistical physics. Previously, a class of 2D cellular models has been shown to undergo a rigidity transition controlled by a mechanical parameter that specifies cell shapes. Here, we generalize this model to 3D and find a rigidity transition that is similarly controlled by the preferred surface area S 0: the model is solid-like below a dimensionless surface area of {s}0\\equiv {S}0/{\\bar{V}}2/3≈ 5.413 with \\bar{V} being the average cell volume, and fluid-like above this value. We demonstrate that, unlike jamming in soft spheres, residual stresses are necessary to create rigidity. These stresses occur precisely when cells are unable to obtain their desired geometry, and we conjecture that there is a well-defined minimal surface area possible for disordered cellular structures. We show that the behavior of this minimal surface induces a linear scaling of the shear modulus with the control parameter at the transition point, which is different from the scaling observed in particulate matter. The existence of such a minimal surface may be relevant for biological tissues and foams, and helps explain why cell shapes are a good structural order parameter for rigidity transitions in biological tissues.
Connect-disconnect coupling for preadjusted rigid shafts

Science.gov (United States)

Bajkowski, F. W.; Holmberg, A.

1969-01-01

Coupling device enables a rigid shaft to be connected to or disconnected from a fixed base without disturbing the point of adjustment of the shaft in a socket or causing the shaft to rotate. The coupling consists of an externally threaded, internally slotted boss extending from the fixed base.
Rigid polyurethane and kenaf core composite foams

Science.gov (United States)

Rigid polyurethane foams are valuable in many construction applications. Kenaf is a bast fiber plant where the surface stem skin provides bast fibers whose strength-to-weight ratio competes with glass fiber. The higher volume product of the kenaf core is an under-investigated area in composite appli...
Inclusive Business - What It Is All About? Managing Inclusive Companies

Directory of Open Access Journals (Sweden)

Tea Golja

2012-01-01

Full Text Available Following the challenges we face today, the inclusive business models are future business models through which the Millennium Development Goals can be fostered and strengthen. These are the models which, through their strategic orientation on inclusivity, include low income communities in their value chain. This can be done through combining variety of strategies which all have two common points – recognition of stakeholders and adjustment of the product to the target market. The paper presents the analysis of inclusive markets. Hence, the research results show the dispersion of inclusive businesses worldwide, type of the organization, sector coverage, and contribution to MDGs as well as the particular way of inclusion of low income communities in their value chain. The aim is to present how inclusive business benefits not only the low income societies, but the companies that operate in this way as well.

Designing Inclusive Systems Designing Inclusion for Real-world Applications

CERN Document Server

Clarkson, John; Robinson, Peter; Lazar, Jonathan; Heylighen, Ann

2012-01-01

The Cambridge Workshops on Universal Access and Assistive Technology (CWUAAT) are a series of workshops held at a Cambridge University College every two years. The workshop theme: “Designing inclusion for real-world applications” refers to the emerging potential and relevance of the latest generations of inclusive design thinking, tools, techniques, and data, to mainstream project applications such as healthcare and the design of working environments. Inclusive Design Research involves developing tools and guidance enabling product designers to design for the widest possible population, for a given range of capabilities. There are five main themes: •Designing for the Real-World •Measuring Demand And Capabilities •Designing Cognitive Interaction with Emerging Technologies •Design for Inclusion •Designing Inclusive Architecture In the tradition of CWUAAT, we have solicited and accepted contributions over a wide range of topics, both within individual themes and also across the workshop’s scope. ...
Mental set and creative thought in social conflict : Threat rigidity versus motivated focus

NARCIS (Netherlands)

De Dreu, Carsten K. W.; Nijstad, Bernard A.

According to the traditional threat-rigidity reasoning, people in social conflict will be less flexible, less creative, more narrow-minded, and more rigid in their thinking when they adopt a conflict rather than a cooperation mental set. The authors propose and test an alternative, motivated focus
Body fixed frame, rigid gauge rotations and large N random fields in QCD

International Nuclear Information System (INIS)

Levit, S.

1995-01-01

The ''body fixed frame'' with respect to local gauge transformations is introduced. Rigid gauge ''rotations'' in QCD and their Schroedinger equation are studied for static and dynamic quarks. Possible choices of the rigid gauge field configuration corresponding to a non-vanishing static colormagnetic field in the ''body fixed'' frame are discussed. A gauge invariant variational equation is derived in this frame. For large number N of colors the rigid gauge field configuration is regarded as random with maximally random probability distribution under constraints on macroscopic-like quantities. For the uniform magnetic field the joint probability distribution of the field components is determined by maximizing the appropriate entropy under the area law constraint for the Wilson loop. In the quark sector the gauge invariance requires the rigid gauge field configuration to appear not only as a background but also as inducing an instantaneous quark-quark interaction. Both are random in the large N limit. (orig.)
Testing non-rigid registration of nuclear medicine data using synthetic derived SPECT images

International Nuclear Information System (INIS)

Todd-Pokropek, A.

2002-01-01

Aim: Non-rigid registration is needed to build atlas data to make statistical tests of significance of uptake in nuclear medicine (NM). Non-rigid registration is much more difficult than rigid registration to validate since some kind of matching function must be defined throughout the volume being registered, and no suitable gold standards exist. The aim here has been to assess non-rigid methods of registration and deformation for NM to NM and NM to MRI data. An additional aim has been to derive good synthetic SPECT images from other NM and MRI data to be used after as reference standards. Material and Methods: Phantom and patient test images have been acquired for both NM and MRI, which are then used to generate projections, where the characteristics of the images are modified to change both signal and noise properties. These derived images are different in character but perfectly registered with the original data, and can then be deformed in a known manner. The registration algorithm is then run backwards to re-register the modified deformed data with the original images. A technique has been developed to assess the vector fields of the original deformation to the reverse non-rigid registration field. Results: The main purpose of this paper is to describe a methodology for optimising algorithms, not to develop the algorithms themselves. Two different algorithms based on optic flow and thin plate spline interpolation have been intercompared and in particular the constraints imposed tested. Considerable differences in matching can be observed in different regions for example edge and centre of brain. Conclusions: Quadratic distance between known makers is a bad estimate to use to assess non-rigid registration. A robust statistic has been developed which can be used to optimise non-rigid algorithms based on the use of synthetic SPECT reference datasets. While the task being tested is simpler than the real clinical task, it is the first essential step in the
Blind source separation based on time-frequency morphological characteristics for rigid acoustic scattering by underwater objects

Science.gov (United States)

Yang, Yang; Li, Xiukun

2016-06-01

Separation of the components of rigid acoustic scattering by underwater objects is essential in obtaining the structural characteristics of such objects. To overcome the problem of rigid structures appearing to have the same spectral structure in the time domain, time-frequency Blind Source Separation (BSS) can be used in combination with image morphology to separate the rigid scattering components of different objects. Based on a highlight model, the separation of the rigid scattering structure of objects with time-frequency distribution is deduced. Using a morphological filter, different characteristics in a Wigner-Ville Distribution (WVD) observed for single auto term and cross terms can be simplified to remove any cross-term interference. By selecting time and frequency points of the auto terms signal, the accuracy of BSS can be improved. An experimental simulation has been used, with changes in the pulse width of the transmitted signal, the relative amplitude and the time delay parameter, in order to analyzing the feasibility of this new method. Simulation results show that the new method is not only able to separate rigid scattering components, but can also separate the components when elastic scattering and rigid scattering exist at the same time. Experimental results confirm that the new method can be used in separating the rigid scattering structure of underwater objects.
Non-rigid registration by geometry-constrained diffusion

DEFF Research Database (Denmark)

Andresen, Per Rønsholt; Nielsen, Mads

1999-01-01

Assume that only partial knowledge about a non-rigid registration is given so that certain point, curves, or surfaces in one 3D image map to certain points, curves, or surfaces in another 3D image. We are facing the aperture problem because along the curves and surfaces, point correspondences...
Nonlinear mechanics of non-rigid origami: an efficient computational approach

Science.gov (United States)

Liu, K.; Paulino, G. H.

2017-10-01

Origami-inspired designs possess attractive applications to science and engineering (e.g. deployable, self-assembling, adaptable systems). The special geometric arrangement of panels and creases gives rise to unique mechanical properties of origami, such as reconfigurability, making origami designs well suited for tunable structures. Although often being ignored, origami structures exhibit additional soft modes beyond rigid folding due to the flexibility of thin sheets that further influence their behaviour. Actual behaviour of origami structures usually involves significant geometric nonlinearity, which amplifies the influence of additional soft modes. To investigate the nonlinear mechanics of origami structures with deformable panels, we present a structural engineering approach for simulating the nonlinear response of non-rigid origami structures. In this paper, we propose a fully nonlinear, displacement-based implicit formulation for performing static/quasi-static analyses of non-rigid origami structures based on `bar-and-hinge' models. The formulation itself leads to an efficient and robust numerical implementation. Agreement between real models and numerical simulations demonstrates the ability of the proposed approach to capture key features of origami behaviour.
Different catalysts for new polyols for rigid PUR-PIR foams

Directory of Open Access Journals (Sweden)

Liszkowska Joanna

2015-12-01

Full Text Available New polyols were synthesized with 2-hydroxypropane-1.2.3-tricarboxylic acid and butane-1,4-diol (1.4-BD. The synthesis was performed using different catalysts in the amount of 0.1%. Used catalyst: Tyzor TPT, tin(II acetate, sulfuric(IV acid. The fourth reaction was conducted without the use of a catalyst. The polyols’ properties were evaluated with regards to the usefulness in rigid polyurethane-polyisocyanurate (PUR-PIR foams (acid value, density, pH and solubility, FTIR spectra. Based on the research, it was evaluated that only the polyol synthesized using Tyzor TPT (E6 was useful in production of rigid PUR-PIR foams. Its hydroxyl number was 496 mgKOH/g and its viscosity was about 14 552 mPa · s. A series of five foams P6.1–P6.5 was produced with this polyol. Rigid foams test results indicated that the amount of this compound in the foam substantially affects its compressive strength, density and their retention. The foams have low brittleness values.
Some Theoretical Essences of Lithuania Squares Formation

Directory of Open Access Journals (Sweden)

Gintautas Tiškus

2016-04-01

Full Text Available In the Lithuanian acts of law and in the scientific literature there are no clear criteria and notions to define a square. The unbuilt city space places or the gaps between buildings are often defined as the squares, which do not have clear limits or destination. The mandatory attributes of the place which is called the square are indicated in the article, the notion of square is defined. The article deals with Lithuanian squares theme, analyses the differences between representation and representativeness. The article aims to indicate an influence of city environmental context and monument in the square on its function. The square is an independent element of city plan structure, but it is not an independent element of city spatial structure. The space and environment of the square are related to each other not only by physical, aesthetical relations, but as well as by causalities, which may be named as the essences of squares’ formation. The interdisciplinary discourse analysis method is applied in the article.
Tidal Evolution of Asteroidal Binaries. Ruled by Viscosity. Ignorant of Rigidity

OpenAIRE

Efroimsky, Michael

2015-01-01

The rate of tidal evolution of asteroidal binaries is defined by the dynamical Love numbers divided by quality factors. Common is the (often illegitimate) approximation of the dynamical Love numbers with their static counterparts. As the static Love numbers are, approximately, proportional to the inverse rigidity, this renders a popular fallacy that the tidal evolution rate is determined by the product of the rigidity by the quality factor: $\\,k_l/Q\\propto 1/(\\mu Q)\\,$. In reality, the dynami...
Latin Squares

Indian Academy of Sciences (India)

Admin

2012-09-07

Sep 7, 2012 ... must first talk of permutations and Latin squares. A permutation of a finite set of objects is a linear arrange- ment of ... with a special element 1 ... Of course, this has .... tion method to disprove Euler's conjecture for infinitely.
21 CFR 178.3790 - Polymer modifiers in semirigid and rigid vinyl chloride plastics.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polymer modifiers in semirigid and rigid vinyl...: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3790 Polymer modifiers in semirigid and rigid vinyl chloride plastics. The polymers identified in paragraph (a) of this...
Rheology of multiphase polymer systems using novel "melt rigidity" evaluation approach

Science.gov (United States)

Kracalik, Milan

2015-04-01

Multiphase polymer systems like blends, composites and nanocomposites exhibit complex rheological behaviour due to physical and also possibly chemical interactions between individual phases. Up to now, rheology of heterogeneous polymer systems has been usually described by evaluation of viscosity curve (shear thinning phenomenon), storage modulus curve (formation of secondary plateau) or plotting information about damping behaviour (e.g. Van Gurp-Palmen-plot). On the contrary to evaluation of damping behaviour, "melt rigidity" approach has been introduced for description of physical network of rigid particles in polymer matrix as relation of ∫G'/∫G" over specific frequency range. This approach has been experimentally proved for polymer nanocomposites in order to compare shear flow characteristics with elongational flow field. In this contribution, LDPE-clay nanocomposites with different dispersion grades (physical networks) have been prepared and characterized by both conventional as well as novel "melt rigidity" approach.
Field dependent cosmic ray streaming at high rigidities

International Nuclear Information System (INIS)

Swinson, D.B.

1976-01-01

Data from underground μ meson telescopes at depths of 25, 40, and 80 mwe covering the period 1965--1973 have been analyzed as a function of interplanetary magnetic field direction. Cosmic ray streaming both in and perpendicular to the ecliptic plane, with directions dependent on the sense of the interplanetary magnetic field, is observed throughout the period at all depths. The field dependent streaming in the ecliptic plane exhibits some variability in amplitude and phase but contains a component in the direction perpendicular to the interplanetary magnetic field direction which is consistent with B x delN streaming due to a perpendicular cosmic ray density gradient pointing southward (higher density below the ecliptic plane than above it). In the case of the field dependent streaming perpendicular to the ecliptic plane the direction of the streaming has remained remarkably consistent over the 9-year period. One possible source of this streaming is B x delN streaming due to a radial heliocentric cosmic ray density gradient; this possibility is discussed along with other possible sources. There does not appear to be an obvious variation in the amplitude of the field dependent streaming either in or perpendicular to the ecliptic plane with increasing rigidity; both effects are still apparent at rigidities well above the 52-GV threshold rigidity of the Socorro 80-mwe telescope. The amplitudes of both anisotropies appear larger at solar maximum than at solar minimum
Network rigidity and properties of SiO2 and GeO2 glasses under pressure.

Science.gov (United States)

Trachenko, Kostya; Dove, Martin T; Brazhkin, Vadim; El'kin, F S

2004-09-24

We report in situ studies of SiO2 glass under pressure and find that temperature-induced densification takes place in a pressure window. To explain this effect, we study how rigidity of glasses changes under pressure, with rigidity percolation affecting the dynamics of local relaxation events. We link rigidity percolation in glasses to other effects, including a large increase of crystallization temperature and logarithmic relaxation under pressure.
Magnetism and magnetostriction in a degenerate rigid band

International Nuclear Information System (INIS)

Kulakowski, K.; Barbara, B.

1990-09-01

We investigate the influence of the spin-orbit coupling on the magnetic and magnetoelastic phenomena in ferromagnetic band systems. The description is within the Stoner model of a degenerate rigid band, for temperature T = O. (author). 14 refs
Estimating the angular velocity of a rigid body moving in the plane from tangential and centripetal acceleration measurements

International Nuclear Information System (INIS)

Cardou, Philippe; Angeles, Jorge

2008-01-01

Two methods are available for the estimation of the angular velocity of a rigid body from point-acceleration measurements: (i) the time-integration of the angular acceleration and (ii) the square-rooting of the centripetal acceleration. The inaccuracy of the first method is due mainly to the accumulation of the error on the angular acceleration throughout the time-integration process, which does not prevent that it be used successfully in crash tests with dummies, since these experiments never last more than one second. On the other hand, the error resulting from the second method is stable through time, but becomes inaccurate whenever the rigid body angular velocity approaches zero, which occurs in many applications. In order to take advantage of the complementarity of these two methods, a fusion of their estimates is proposed. To this end, the accelerometer measurements are modeled as exact signals contaminated with bias errors and Gaussian white noise. The relations between the variables at stake are written in the form of a nonlinear state-space system in which the angular velocity and the angular acceleration are state variables. Consequently, a minimum-variance-error estimate of the state vector is obtained by means of extended Kalman filtering. The performance of the proposed estimation method is assessed by means of simulation. Apparently, the resulting estimation method is more robust than the existing accelerometer-only methods and competitive with gyroscope measurements. Moreover, it allows the identification and the compensation of any bias error in the accelerometer measurements, which is a significant advantage over gyroscopes
INCLUSION OF CHILDREN WITH INTELLECTUAL AND MULTIPLE DISABILITIES: A COMMUNITY-BASED REHABILITATION APPROACH, INDIA

Directory of Open Access Journals (Sweden)

Ram LAKHAN

2013-03-01

Full Text Available Background: Inclusion of children with intellectual disabilities (ID and multiple disabilities (MD in regular schools in India is extremely poor. One of the key objectives of community-based rehabilitation (CBR is to include ID & MD children in regular schools. This study attempted to find out association with age, ID severity, poverty, gender, parent education, population, and multiple disabilities comprising one or more disorders cerebral palsy, epilepsy and psychiatric disorders with inclusion among 259 children in Barwani Block of Barwani District in the state of Madhya Pradesh, India.Aim: Inclusion of children with intellectual and multiple disabilities in regular schools through CBR approach in India.Method: Chi square test was conducted to investigate association between inclusion and predictor variables ID categories, age, gender, poverty level, parent education, population type and multiple disabilities. Result: Inclusion was possible for borderline 2(66.4%, mild 54(68.3%, moderate 18(18.2%, and age range from 5 to 12 years 63 (43%. Children living in poor families 63 (30.6%, not poor 11(18.9%, parental education none 52 (26%, primary level 11 (65%, middle school 10 (48% high school 0 (0% and bachelor degree 1(7%, female 34 (27.9%, male 40 (29.2%, tribal 40 (28.7%, non-tribal 34(28.3% and multiple disabled with cerebral palsy 1(1.2%, epilepsy 3 (4.8% and psychiatry disorders 12 (22.6% were able to receive inclusive education. Significant difference in inclusion among ID categories (c2=99.8, p < 0.001, poverty (c2=3.37, p 0.044, parental education (c2=23.7, p < 0.001, MD CP (c2=43.9, p < 0.001 and epilepsy (c2=22.4, p < 0.001 were seen.Conclusion: Inclusion through CBR is feasible and acceptable in poor rural settings in India. CBR can facilitate inclusion of children with borderline, mild and moderate categories by involving their parents, teachers and community members.
Orangutans (Pongo spp.) may prefer tools with rigid properties to flimsy tools.

Science.gov (United States)

Walkup, Kristina R; Shumaker, Robert W; Pruetz, Jill D

2010-11-01

Preference for tools with either rigid or flexible properties was explored in orangutans (Pongo spp.) through an extension of D. J. Povinelli, J. E. Reaux, and L. A. Theall's (2000) flimsy-tool problem. Three captive orangutans were presented with three unfamiliar pairs of tools to solve a novel problem. Although each orangutan has spontaneously used tools in the past, the tools presented in this study were novel to the apes. Each pair of tools contained one tool with rigid properties (functional) and one tool with flimsy properties (nonfunctional). Solving the problem required selection of a rigid tool to retrieve a food reward. The functional tool was selected in nearly all trials. Moreover, two of the orangutans demonstrated this within the first test trials with each of the three tool types. Although further research is required to test this statistically, it suggests either a preexisting preference for rigid tools or comprehension of the relevant features required in a tool to solve the task. The results of this study demonstrate that orangutans can recognize, or learn to recognize, relevant tool properties and can choose an appropriate tool to solve a problem. (PsycINFO Database Record (c) 2010 APA, all rights reserved).
Observation of the Identical Rigidity Dependence of He, C, and O Cosmic Rays at High Rigidities by the Alpha Magnetic Spectrometer on the International Space Station

Science.gov (United States)

Aguilar, M.; Ali Cavasonza, L.; Alpat, B.; Ambrosi, G.; Arruda, L.; Attig, N.; Aupetit, S.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Başeǧmez-du Pree, S.; Battarbee, M.; Battiston, R.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bindel, K. F.; Bindi, V.; de Boer, W.; Bollweg, K.; Bonnivard, V.; Borgia, B.; Boschini, M. J.; Bourquin, M.; Bueno, E. F.; Burger, J.; Burger, W. J.; Cadoux, F.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Castellini, G.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, G. M.; Chen, H. S.; Cheng, L.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Creus, W.; Crispoltoni, M.; Cui, Z.; Dadzie, K.; Dai, Y. M.; Datta, A.; Delgado, C.; Della Torre, S.; Demakov, O.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Dong, F.; Donnini, F.; Duranti, M.; D'Urso, D.; Egorov, A.; Eline, A.; Eronen, T.; Feng, J.; Fiandrini, E.; Fisher, P.; Formato, V.; Galaktionov, Y.; Gallucci, G.; García-López, R. J.; Gargiulo, C.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; Giovacchini, F.; Gómez-Coral, D. M.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guo, K. H.; Haino, S.; Han, K. C.; He, Z. H.; Heil, M.; Hoffman, J.; Hsieh, T. H.; Huang, H.; Huang, Z. C.; Huh, C.; Incagli, M.; Ionica, M.; Jang, W. Y.; Jia, Yi; Jinchi, H.; Kang, S. C.; Kanishev, K.; Khiali, B.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Konak, C.; Kounina, O.; Kounine, A.; Koutsenko, V.; Kulemzin, A.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. S.; Li, J. Q.; Li, Q.; Li, T. X.; Li, Y.; Li, Z. H.; Li, Z. Y.; Lim, S.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, Hu; Lordello, V. D.; Lu, S. Q.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lyu, S. S.; Machate, F.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mikuni, V. M.; Mo, D. C.; Mott, P.; Nelson, T.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Oliva, A.; Orcinha, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Pauluzzi, M.; Pensotti, S.; Perrina, C.; Phan, H. D.; Picot-Clemente, N.; Pilo, F.; Pizzolotto, C.; Plyaskin, V.; Pohl, M.; Poireau, V.; Quadrani, L.; Qi, X. M.; Qin, X.; Qu, Z. Y.; Räihä, T.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Schael, S.; Schmidt, S. M.; Schulz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shan, B. S.; Shi, J. Y.; Siedenburg, T.; Son, D.; Song, J. W.; Tacconi, M.; Tang, X. W.; Tang, Z. C.; Tescaro, D.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Türkoǧlu, C.; Urban, T.; Vagelli, V.; Valente, E.; Valtonen, E.; Vázquez Acosta, M.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Vitale, V.; Vitillo, S.; Wang, L. Q.; Wang, N. H.; Wang, Q. L.; Wang, X.; Wang, X. Q.; Wang, Z. X.; Wei, C. C.; Weng, Z. L.; Whitman, K.; Wu, H.; Wu, X.; Xiong, R. Q.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Yang, Y.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zannoni, M.; Zeissler, S.; Zhang, C.; Zhang, F.; Zhang, J.; Zhang, J. H.; Zhang, S. W.; Zhang, Z.; Zheng, Z. M.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.; AMS Collaboration

2017-12-01

We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90 ×106 helium, 8.4 ×106 carbon, and 7.0 ×106 oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.

Geometric integrators for stochastic rigid body dynamics

KAUST Repository

Tretyakov, Mikhail

2016-01-05

Geometric integrators play an important role in simulating dynamical systems on long time intervals with high accuracy. We will illustrate geometric integration ideas within the stochastic context, mostly on examples of stochastic thermostats for rigid body dynamics. The talk will be mainly based on joint recent work with Rusland Davidchak and Tom Ouldridge.
Combinatorial and Algorithmic Rigidity: Beyond Two Dimensions

Science.gov (United States)

2012-12-01

44]. Theorems of Maxwell- Laman type were ob- tained in [9, 15, 43]. 2 3. Counting and Enumeration. As anticipated in the project, we relied on methods...decompositions. Graphs and Combinatorics, 25:219–238, 2009. [43] I. Streinu and L. Theran. Slider-pinning rigidity: a Maxwell- Laman -type theorem. Discrete and
Rigidity Sensing Explained by Active Matter Theory

OpenAIRE

Marcq, Philippe; Yoshinaga, Natsuhiko; Prost, Jacques

2011-01-01

The magnitude of traction forces exerted by living animal cells on their environment is a monotonically increasing and approximately sigmoidal function of the stiffness of the external medium. We rationalize this observation using active matter theory, and propose that adaptation to substrate rigidity results from an interplay between passive elasticity and active contractility.
Geometric integrators for stochastic rigid body dynamics

KAUST Repository

Tretyakov, Mikhail

2016-01-01

Geometric integrators play an important role in simulating dynamical systems on long time intervals with high accuracy. We will illustrate geometric integration ideas within the stochastic context, mostly on examples of stochastic thermostats for rigid body dynamics. The talk will be mainly based on joint recent work with Rusland Davidchak and Tom Ouldridge.
Rigidity theorem for Willmore surfaces in a sphere

Indian Academy of Sciences (India)

Home; Journals; Proceedings – Mathematical Sciences; Volume 126; Issue 2. Rigidity ... Center of Mathematical Sciences, Zhejiang University, Hangzhou 310027, People's Republic of China; College of Mathematics and Information Science, Jiangxi Normal University, Nanchang 330022, People's Republic of China ...
Mixed Volume and Distance Geometry Techniques for Counting Euclidean Embeddings of Rigid Graphs

NARCIS (Netherlands)

I.Z. Emiris; E.P. Tsigaridas; A. Varvitsiotis (Antonios); A. Mucherino (Antonio); C. Lavor; L. Liberti; N. Maculan

2013-01-01

htmlabstractA graph G is called generically minimally rigid in Rd if, for any choice of sufficiently generic edge lengths, it can be embedded in Rd in a finite number of distinct ways, modulo rigid transformations. Here, we deal with the problem of determining tight bounds on the number of such
Discrete least squares polynomial approximation with random evaluations − application to parametric and stochastic elliptic PDEs

KAUST Repository

Chkifa, Abdellah

2015-04-08

Motivated by the numerical treatment of parametric and stochastic PDEs, we analyze the least-squares method for polynomial approximation of multivariate functions based on random sampling according to a given probability measure. Recent work has shown that in the univariate case, the least-squares method is quasi-optimal in expectation in [A. Cohen, M A. Davenport and D. Leviatan. Found. Comput. Math. 13 (2013) 819–834] and in probability in [G. Migliorati, F. Nobile, E. von Schwerin, R. Tempone, Found. Comput. Math. 14 (2014) 419–456], under suitable conditions that relate the number of samples with respect to the dimension of the polynomial space. Here “quasi-optimal” means that the accuracy of the least-squares approximation is comparable with that of the best approximation in the given polynomial space. In this paper, we discuss the quasi-optimality of the polynomial least-squares method in arbitrary dimension. Our analysis applies to any arbitrary multivariate polynomial space (including tensor product, total degree or hyperbolic crosses), under the minimal requirement that its associated index set is downward closed. The optimality criterion only involves the relation between the number of samples and the dimension of the polynomial space, independently of the anisotropic shape and of the number of variables. We extend our results to the approximation of Hilbert space-valued functions in order to apply them to the approximation of parametric and stochastic elliptic PDEs. As a particular case, we discuss “inclusion type” elliptic PDE models, and derive an exponential convergence estimate for the least-squares method. Numerical results confirm our estimate, yet pointing out a gap between the condition necessary to achieve optimality in the theory, and the condition that in practice yields the optimal convergence rate.
Oxygen permeability (Dk) of thirty-seven rigid contact lens materials.

Science.gov (United States)

Benjamin, William J; Cappelli, Quido A

2002-02-01

Oxygen permeability (Dk) was determined for 37 available rigid contact lens materials in a masked fashion. The results were compared with those of an earlier study that included different lots of 14 test materials assessed in the current study. Six lenses of different thicknesses in each test and reference material were obtained. Test materials were arranged in sets of six to eight materials per set. Each set of materials, with inclusion of at least two reference materials for the purpose of simultaneous calibration, was measured to obtain preliminary amperages. Four preliminary measures were performed per thickness, resulting in 24 per material, in a schedule designed to spread the potential effects of machine drift and other factors. The mean preliminary amperages were used to derive corrected Dk values according to American National Standards Institute (ANSI) Z80.20-1998, and the values were linearly calibrated using the measured and established Dk values of the reference materials. The resistance (t/Dk) vs. thickness (t) plots for the 37 test and seven reference materials were approximated linearly. In 54 of 57 linear regressions, the coefficients of determination (R2) were >0.96, and in 48 instances were >0.98. Fourteen Dk values from the current study and an earlier study were linearly correlated (R2 = 0.9846), with a slope close to unity (+1.056) and intercept close to zero (-0.292). Ten of the current values fell within 10% of their corresponding earlier values. Only three current Dk values fell outside of the ANSI Z80.20-1998 tolerance for Dk (+/-20%). Two of these Dk values met the product tolerance when an obvious outlying point was graphically identified and omitted from the linear resistance (t/Dk) vs. thickness (t) regression. Omission of a single outlying point from a linear resistance vs. thickness regression can help provide a more valid Dk value. The ANSI Z80.20-1998 tolerance of +/-20% on Dk and the measurement reproducibility of +/-10% were
Thermal gradient brine inclusion migration in salt study: gas-liquid inclusions, preliminary model

International Nuclear Information System (INIS)

Olander, D.R.; Machiels, A.J.

1979-10-01

Natural salt deposits contain small cubical inclusions of brine distributed through the salt. Temperature gradients, resulting from storing heat-generating wastes in the salt, can cause the inclusions to move through the salt. Prediction of the rate and amount of brine-inclusion migration is necessary for the evaluation of bedded or domed salts as possible media for waste repositories. Inclusions filled exclusively with liquid migrate up the temperature gradient towards the heat source. The solubility of salt in the brine inclusion increases with temperature. Consequently, salt dissolves into the inclusion across the hot surface and crystallizes out at the cold surface. Diffusion of salt within the liquid phase from the hot to the cold faces causes the inclusions to move in the opposite direction. In so doing, they change shape and eventually become rectangular parallelipipeds with a width (dimension perpendicular to the thermal gradient) much larger than the thickness (dimension in the direction of the thermal gradient). The inclusions may also contain a gas phase predominantly consisting of water vapor. These entities are termed two-phase or gas-liquid inclusions. The two-phase inclusions usually migrate down the temperature gradient away from the heat source remaining more-or-less cubical. A two-phase inclusion also forms when an all-liquid inclusion reaches the waste package; upon opening up at the salt-package interface, the brine partially evaporates and the inclusion reseals with some insoluble gas trapped inside. These gas-liquid inclusions proceed to move down the temperature gradient, in the opposite sense of the all-liquid inclusions. The gas-liquid inclusions phenomenon provides a pathway by which radionuclides leached from the wasteform by the brine can be transported away from the waste package and thus might have greater access to the biosphere
Computing the Free Energy along a Reaction Coordinate Using Rigid Body Dynamics.

Science.gov (United States)

Tao, Peng; Sodt, Alexander J; Shao, Yihan; König, Gerhard; Brooks, Bernard R

2014-10-14

The calculations of potential of mean force along complex chemical reactions or rare events pathways are of great interest because of their importance for many areas in chemistry, molecular biology, and material science. The major difficulty for free energy calculations comes from the great computational cost for adequate sampling of the system in high-energy regions, especially close to the reaction transition state. Here, we present a method, called FEG-RBD, in which the free energy gradients were obtained from rigid body dynamics simulations. Then the free energy gradients were integrated along a reference reaction pathway to calculate free energy profiles. In a given system, the reaction coordinates defining a subset of atoms (e.g., a solute, or the quantum mechanics (QM) region of a quantum mechanics/molecular mechanics simulation) are selected to form a rigid body during the simulation. The first-order derivatives (gradients) of the free energy with respect to the reaction coordinates are obtained through the integration of constraint forces within the rigid body. Each structure along the reference reaction path is separately subjected to such a rigid body simulation. The individual free energy gradients are integrated along the reference pathway to obtain the free energy profile. Test cases provided demonstrate both the strengths and weaknesses of the FEG-RBD method. The most significant benefit of this method comes from the fast convergence rate of the free energy gradient using rigid-body constraints instead of restraints. A correction to the free energy due to approximate relaxation of the rigid-body constraint is estimated and discussed. A comparison with umbrella sampling using a simple test case revealed the improved sampling efficiency of FEG-RBD by a factor of 4 on average. The enhanced efficiency makes this method effective for calculating the free energy of complex chemical reactions when the reaction coordinate can be unambiguously defined by a
Inclusive Education in Italy: Description and Reflections on Full Inclusion

Science.gov (United States)

Anastasiou, Dimitris; Kauffman, James M.; Di Nuovo, Santo

2015-01-01

Inclusion of students with disabilities when appropriate is an important goal of special education for students with special needs. Full inclusion, meaning no education for any child in a separate setting, is held to be desirable by some, and Italy is likely the nation with an education system most closely approximating full inclusion on the…
Adsorption of asymmetric rigid rods or heteronuclear diatomic moleculeson homogeneous surfaces

Science.gov (United States)

Engl, W.; Courbin, L.; Panizza, P.

2004-10-01

We treat the adsorption on homogeneous surfaces of asymmetric rigid rods (like for instance heteronuclear diatomic molecules). We show that the n→0 vector spin formalism is well suited to describe such a problem. We establish an isomorphism between the coupling constants of the magnetic Hamiltonian and the adsorption parameters of the rigid rods. By solving this Hamiltonian within a mean-field approximation, we obtain analytical expressions for the densities of the different rod’s configurations, both isotherm and isobar adsorptions curves. The most probable configurations of the molecules (normal or parallel to the surface) which depends on temperature and energy parameters are summarized in a diagram. We derive that the variation of Qv , the heat of adsorption at constant volume, with the temperature is a direct signature of the adsorbed molecules configuration change. We show that this formalism can be generalized to more complicated problems such as for instance the adsorption of symmetric and asymmetric rigid rods mixtures in the presence or not of interactions.
Modyfication of the Rigid Polyurethane-Polyisocyanurate Foams

Directory of Open Access Journals (Sweden)

Bogusław Czupryński

2014-01-01

Full Text Available The effect of polyethylene glycol 1500 on physicomechanical properties of rigid polyurethane-polyisocyanurate (PUR-PIR foams has been studied. It was found that application of polyethylene glycol 1500 for synthesis of foams in amount from 0% to 20% w/w had an effect on reduction of brittleness and softening point, while the greater the increase in compressive strength the higher its content in foam composition was. Wastes from production of these foams were ground and subjected to glycolysis in diethylene glycol with the addition of ethanolamine and zinc stearate. Liquid brown products were obtained. Properties of the resulting products were defined in order to determine their suitability for synthesis of new foams. It was found that glycolysate 6 was the most suitable for reuse and its application in different amounts allowed us to prepare 4 new foams (nos. 25, 26, 27, and 28. Properties of foams prepared in this manner were determined and, on their basis, the suitability of glycolysates for production of rigid PUR-PIR foams was evaluated.
Least-squares model-based halftoning

Science.gov (United States)

Pappas, Thrasyvoulos N.; Neuhoff, David L.

1992-08-01

A least-squares model-based approach to digital halftoning is proposed. It exploits both a printer model and a model for visual perception. It attempts to produce an 'optimal' halftoned reproduction, by minimizing the squared error between the response of the cascade of the printer and visual models to the binary image and the response of the visual model to the original gray-scale image. Conventional methods, such as clustered ordered dither, use the properties of the eye only implicitly, and resist printer distortions at the expense of spatial and gray-scale resolution. In previous work we showed that our printer model can be used to modify error diffusion to account for printer distortions. The modified error diffusion algorithm has better spatial and gray-scale resolution than conventional techniques, but produces some well known artifacts and asymmetries because it does not make use of an explicit eye model. Least-squares model-based halftoning uses explicit eye models and relies on printer models that predict distortions and exploit them to increase, rather than decrease, both spatial and gray-scale resolution. We have shown that the one-dimensional least-squares problem, in which each row or column of the image is halftoned independently, can be implemented with the Viterbi's algorithm. Unfortunately, no closed form solution can be found in two dimensions. The two-dimensional least squares solution is obtained by iterative techniques. Experiments show that least-squares model-based halftoning produces more gray levels and better spatial resolution than conventional techniques. We also show that the least- squares approach eliminates the problems associated with error diffusion. Model-based halftoning can be especially useful in transmission of high quality documents using high fidelity gray-scale image encoders. As we have shown, in such cases halftoning can be performed at the receiver, just before printing. Apart from coding efficiency, this approach
Polyelectrolyte Complex Inclusive Biohybrid Microgels for Tailoring Delivery of Copigmented Anthocyanins.

Science.gov (United States)

Tan, Chen; B Celli, Giovana; Lee, Michelle; Licker, Jonathan; Abbaspourrad, Alireza

2018-05-14

This study fabricated a novel biohybrid microgel containing polysaccharide-based polyelectrolyte complexes (PECs) for anthocyanins. Herein, anthocyanins were encapsulated into PECs composed of chondroitin sulfate and chitosan, followed by incorporation into alginate microgels using emulsification/internal gelation method. We demonstrated that PECs incorporation strongly affected the properties of microgels, dependent on the polysaccharide concentration and pH in which they were fabricated. The dense internal network surrounded by an alginate shell was clearly visualized in cross-sectioned PECs-microgels. Stability studies carried out under varying ionic strength and pH conditions demonstrated the stimuli-responsiveness of the PECs-microgels. Additionally, the presence of PECs conferred microgels with high rigidity during freeze-drying and excellent reconstitution capacity upon rehydration. These observations were attributed to the modulation of electrostatic and hydrogen-bonding cross-linking between PECs and the alginate gel matrix and suggest the PECs inclusive microgels hold promise as delivery vehicles for the controlled release of hydrophilic bioactive compounds.
Delimiting Inclusive Design

DEFF Research Database (Denmark)

Herriott, Richard

2014-01-01

This paper was written as an answer to the question raised by my PhD dissertation on accessibility through user-centred and Inclusive Design (ID) methods: can Inclusive Design be delimited? The literature on Inclusive Design deals almost entrirely with consumer product design and assistive...
Handedness in shearing auxetics creates rigid and compliant structures

Science.gov (United States)

Lipton, Jeffrey Ian; MacCurdy, Robert; Manchester, Zachary; Chin, Lillian; Cellucci, Daniel; Rus, Daniela

2018-05-01

In nature, repeated base units produce handed structures that selectively bond to make rigid or compliant materials. Auxetic tilings are scale-independent frameworks made from repeated unit cells that expand under tension. We discovered how to produce handedness in auxetic unit cells that shear as they expand by changing the symmetries and alignments of auxetic tilings. Using the symmetry and alignment rules that we developed, we made handed shearing auxetics that tile planes, cylinders, and spheres. By compositing the handed shearing auxetics in a manner inspired by keratin and collagen, we produce both compliant structures that expand while twisting and deployable structures that can rigidly lock. This work opens up new possibilities in designing chemical frameworks, medical devices like stents, robotic systems, and deployable engineering structures.
Exotic distributions of rigid unit modes in the reciprocal spaces of framework aluminosilicates

International Nuclear Information System (INIS)

Dove, Martin T; Pryde, Alexandra K A; Heine, Volker; Hammonds, Kenton D

2007-01-01

Until recently it was assumed that rigid unit modes, defined as the zero-frequency solutions to the dynamical equations for an infinite framework of rigid corner-linked tetrahedra, were confined to a small set of normal modes with wavevectors on lines or planes of special symmetry in reciprocal space. Using a search method that explores the full three-dimensional reciprocal space, we have located rigid unit modes with wavevectors on exotic curved surfaces in reciprocal space for a range of silicate minerals. This has led to the realization that the crystal structures of these minerals contain rather more topological floppiness than had previously been realized. The origin of the exotic RUM surfaces remains to be understood
Analysis on the resistive force in penetration of a rigid projectile

Directory of Open Access Journals (Sweden)

Xiao-wei Chen

2014-09-01

Full Text Available According to the dimensionless formulae of DOP (depth of penetration of a rigid projectile into different targets, the resistive force which a target exerts on the projectile during the penetration of rigid projectile is theoretically analyzed. In particular, the threshold Vc of impact velocity applicable for the assumption of constant resistive force is formulated through impulse analysis. The various values of Vc corresponding to different pairs of projectile-target are calculated, and the consistency of the relative test data and numerical results is observed.
Social imaginaries and inclusion

DEFF Research Database (Denmark)

Hansen, Janne Hedegaard

2016-01-01

that inclusion on the one hand may be seen to be about human rights, solidarity, and democracy, and on the other hand, it is about ensuring the cohesion of neoliberal society by means of every person’s obligation to realize one’s potential through learning, development, and education regardless of one’s needs......, the development of inclusive schools and inclusive learning environments will involve both inclusion and exclusion processes. With this starting point, international educational research knowledge about inclusive schools and inclusive learning environments in general will be related to the fundamental dilemma...

Rigid or flexible sigmoidoscopy in colorectal clinics? Appraisal through a systematic review and meta-analysis.

LENUS (Irish Health Repository)

Ahmad, Nasir Zaheer

2012-06-01

Rigid sigmoidoscopy is sometimes performed at first presentation in colorectal clinics. We assessed the feasibility of flexible sigmoidoscopy in similar situations by comparing it with rigid sigmoidoscopy as a first investigative tool.
Remifentanil-based total intravenous anesthesia for pediatric rigid bronchoscopy: comparison of adjuvant propofol and ketamine

Directory of Open Access Journals (Sweden)

Mefkur Bakan

2014-06-01

Full Text Available OBJECTIVE:Laryngoscopy and stimuli inside the trachea cause an intense sympatho-adrenal response. Remifentanil seems to be the optimal opioid for rigid bronchoscopy due to its potent and short-acting properties. The purpose of this study was to compare bolus propofol and ketamine as an adjuvant to remifentanil-based total intravenous anesthesia for pediatric rigid bronchoscopy.MATERIALS AND METHODS:Forty children under 12 years of age who had been scheduled for a rigid bronchoscopy were included in this study. After midazolam premedication, a 1 µg/kg/min remifentanil infusion was started, and patients were randomly allocated to receive either propofol (Group P or ketamine (Group K as well as mivacurium for muscle relaxation. Anesthesia was maintained with a 1 µg/kg/min remifentanil infusion and bolus doses of propofol or ketamine. After the rigid bronchoscopy, 0.05 µg/kg/min of remifentanil was maintained until extubation. Hemodynamic parameters, emergence characteristics, and adverse events were evaluated.RESULTS:The demographic variables were comparable between the two groups. The decrease in mean arterial pressure from baseline values to the lowest values during rigid bronchoscopy was greater in Group P (p= 0.049, while the reduction in the other parameters and the incidence of adverse events were comparable between the two groups. The need for assisted or controlled mask ventilation after extubation was higher in Group K.CONCLUSION:Remifentanil-based total intravenous anesthesia with propofol or ketamine as an adjuvant drug along with controlled ventilation is a viable technique for pediatric rigid bronchoscopy. Ketamine does not provide a definite advantage over propofol with respect to hemodynamic stability during rigid bronchoscopy, while propofol seems more suitable during the recovery period.
Herbal Prescriptions and Medicinal Herbs for Parkinson-Related Rigidity in Korean Medicine: Identification of Candidates Using Text Mining.

Science.gov (United States)

Park, So Hyun; Hwang, Min Seob; Park, Hye Jin; Shin, Hwa Kyoung; Baek, Jin Ung; Choi, Byung Tae

2018-03-27

Dongeuibogam (DongYiBaoGian), one of the most important books in Korean medicine, comprises a comprehensive summary of all traditional medicines of North-East Asia before the 17th century. This medicinal literature was mined to establish a list of candidate herbs to treat Parkinson-related rigidity. A systematic search for terms describing Parkinson-related rigidity and candidate prescriptions for the treatment of Parkinson-related rigidity in the Dongeuibogam was performed. A high-frequency medicinal herb combination group and candidates for the treatment of Parkinson-related rigidity were also selected through an analysis of medicinal herb combination frequencies. The existing literature pertaining to the potential effects of candidate herbs for Parkinson-related rigidity was reviewed. Ten medicinal herb candidates for the treatment of Parkinson-related rigidity were selected, and their respective precedent studies were analyzed.
Inclusive Discourse? Local Media Coverage of the Terri Schiavo Case.

Science.gov (United States)

Rohlinger, Deana A; Pederson, JoEllen; Valle, Giuseppina

2015-01-01

This article contributes to a more systematic understanding of the role of mainstream media in deliberative processes by analyzing how inclusive local newspapers are of diverse perspectives on the Terri Schiavo case. Using both Pearson's chi-square test and multinomial logistic regression, we assess how ownership, state political ideology, geographic location, and news format affect what ideas are included in the debate over whether Terri Schiavo's hydration and nutrition tubes should be removed as well as the tone with which these ideas are discussed. We find that mainstream newspapers are relatively inclusive of diverse ideas and perspectives-regardless of whether the newspaper is independently or corporately owned, the political leanings of the target audience, and the geographic location of the outlet. However, we also find that local newspapers do significantly differ from one another in terms of the frequency and tone with which they include diverse viewpoints. Our research suggests that local outlets downplay ideas that are likely to be regarded as controversial by their target audiences. We conclude with a discussion of the implications of this research for understanding the role of media in deliberative democratic processes in the United States.
Phenotypic variability within the inclusion body spectrum of basophilic inclusion body disease and neuronal intermediate filament inclusion disease in frontotemporal lobar degenerations with FUS-positive inclusions.

Science.gov (United States)

Gelpi, Ellen; Lladó, Albert; Clarimón, Jordi; Rey, Maria Jesús; Rivera, Rosa Maria; Ezquerra, Mario; Antonell, Anna; Navarro-Otano, Judith; Ribalta, Teresa; Piñol-Ripoll, Gerard; Pérez, Anna; Valldeoriola, Francesc; Ferrer, Isidre

2012-09-01

Basophilic inclusion body disease and neuronal intermediate filament inclusion disease (NIFID) are rare diseases included among frontotemporal lobar degenerations with FUS-positive inclusions (FTLD-FUS). We report clinical and pathologic features of 2 new patients and reevaluate neuropathologic characteristics of 2 previously described cases, including an early-onset case of basophilic inclusion body disease (aged 38 years) with a 5-year disease course and abundant FUS-positive inclusion bodies and 3 NIFID cases. One NIFID case (aged 37 years) presented with early-onset psychiatric disturbances and rapidly progressive cognitive decline. Two NIFID cases had later onset (aged 64 years and 70 years) and complex neurologic deficits. Postmortem neuropathologic studies in late-onset NIFID cases disclosed α-internexin-positive "hyaline conglomerate"-type inclusions that were positive with 1 commercial anti-FUS antibody directed to residues 200 and 250, but these were negative to amino acids 90 and 220 of human FUS. Early-onset NIFID had similar inclusions that were positive with both commercial anti-FUS antibodies. Genetic testing performed on all cases revealed no FUS gene mutations. These findings indicate that phenotypic variability in NIFID, including clinical manifestations and particular neuropathologic findings, may be related to the age at onset and individual differences in the evolution of lesions.
Flexible (Polyactive®) versus rigid (hydroxyapatite) dental implants

NARCIS (Netherlands)

Meijer, G.J.; Heethaar, J.; Cune, M.S.; de Putter, C.; van Blitterswijk, Clemens

1997-01-01

In a beagle dog study, the peri-implant bone changes around flexible (Polyactive®) and rigid hydroxyapatite (HA) implants were investigated radiographically by quantitative digital subtraction analysis and by assessment of marginal bone height, with the aid of a computerized method. A loss of
Effect of chain rigidity on network architecture and deformation behavior of glassy polymer networks

Science.gov (United States)

Knowles, Kyler Reser

Processing carbon fiber composite laminates creates molecular-level strains in the thermoset matrix upon curing and cooling which can lead to failures such as geometry deformations, micro-cracking, and other issues. It is known strain creation is attributed to the significant volume and physical state changes undergone by the polymer matrix throughout the curing process, though storage and relaxation of cure-induced strains remain poorly understood. This dissertation establishes two approaches to address the issue. The first establishes testing methods to simultaneously measure key volumetric properties of a carbon fiber composite laminate and its polymer matrix. The second approach considers the rigidity of the polymer matrix in regards to strain storage and relaxation mechanisms which ultimately control composite performance throughout manufacturing and use. Through the use of a non-contact, full-field strain measurement technique known as digital image correlation (DIC), we describe and implement useful experiments which quantify matrix and composite parameters necessary for simulation efforts and failure models. The methods are compared to more traditional techniques and show excellent correlation. Further, we established relationships which represent matrix-fiber compatibility in regards to critical processing constraints. The second approach involves a systematic study of epoxy-amine networks which are chemically-similar but differ in chain segment rigidity. Prior research has investigated the isomer effect of glassy polymers, showing sizeable differences in thermal, volumetric, physical, and mechanical properties. This work builds on these themes and shows the apparent isomer effect is rather an effect of chain rigidity. Indeed, it was found that structurally-dissimilar polymer networks exhibit very similar properties as a consequence of their shared average network rigidity. Differences in chain packing, as a consequence of chain rigidity, were shown to
Studies on inclusive meson resonance and particle production

International Nuclear Information System (INIS)

Saarikko, Heimo

1978-01-01

Production and decay of meson resonances are studied in medium energy meson-proton collisions. Strong evidence is found that hadronic collisions are dominated by resonance production. Especially the vector mesons have often large inclusive cross sections, typically of the order of few millibarns at the present energies. In all, a majority of pions and kaons appear to be decay products of resonances or other unstable particles. The detailed kinematics of the parent resonance's decays is found to play an important role in determining inclusive pion spectra. The squared transverse momentum distributions of hadrons heavier than the pion appear to have in common an exponential behaviour, with a universal slope for the esponential fall-off. The observed vector meson yields suggest that only a small fraction of the direct lepton production observed at large transverse momentum in nucleon-nucleon interactions is accounted for by the ''old'' vector mesons. An attempt has been made to separate out the central production and fragmentation components of the meson production. Both the central production and the fragmentation of the incoming meson are found to be important mechanisms in the non-strange meson production whereas the central production of strange meson resonances is rare at our energies. The ratios of the observed meson yields are found to be generally in good agreement with a simple quark-counting model. (author)
Design of semi-rigid type of flexible pavements

Directory of Open Access Journals (Sweden)

Pranshoo Solanki

2017-03-01

Full Text Available The primary objective of the study presented in this paper is to develop design curves for performance prediction of stabilized layers and to compare semi-rigid flexible pavement designs between the empirical AASHTO 1993 and the mechanistic-empirical pavement design methodologies. Specifically, comparisons were made for a range of different sections consisting of cementitious layers stabilized with different types and percentages of additives. It is found that the design thickness is influenced by the type of soil, additive, selection of material property and design method. Cost comparisons of sections stabilized with different percentage and type of additives showed that CKD-stabilization provides economically low cost sections as compared to lime- and CFA-stabilized sections. Knowledge gained from the parametric analysis of different sections using AASHTO 1993 and MEPDG is expected to be useful to pavement designers and others in implementation of the new MEPDG for future pavement design. Keywords: Semi-rigid, Mechanistic, Resilient modulus, Fatigue life, Reliability, Traffic
Synthesis of rigid polyurethane foams from phosphorylated biopolyols.

Science.gov (United States)

de Haro, Juan Carlos; López-Pedrajas, Daniel; Pérez, Ángel; Rodríguez, Juan Francisco; Carmona, Manuel

2017-08-18

Renewable resources are playing a key role on the synthesis of biodegradable polyols. Moreover, the incorporation of covalently linked additives is increasing in importance in the polyurethane (PU) market. In this work, previously epoxidized grape seed oil and methyl oleate were transformed into phosphorylated biopolyols through an acid-catalyzed ring-opening hydrolysis in the presence of H 3 PO 4 . The formation of phosphate polyesters was confirmed by FT-IR and 31 P-NMR. However, the synthesis of a high-quality PU rigid foam was not possible using exclusively these polyols attending to their low hydroxyl value. In that way, different rigid PU foams were prepared from the phosphorylated biopolyols and the commercial polyol Alcupol R4520. It was observed that phosphorylated biopolyols can be incorporated up to a 57 wt.% in the PU synthesis without significant structural changes with respect to the commercial foam. Finally, thermogravimetric and EDAX analyses revealed an improvement of thermal stability by the formation of a protective phosphorocarbonaceous char layer.
From Square Dance to Mathematics

Science.gov (United States)

Bremer, Zoe

2010-01-01

In this article, the author suggests a cross-curricular idea that can link with PE, dance, music and history. Teacher David Schmitz, a maths teacher in Illinois who was also a square dance caller, had developed a maths course that used the standard square dance syllabus to teach mathematical principles. He presents an intensive, two-week course…
Lagrange’s Four-Square Theorem

Directory of Open Access Journals (Sweden)

Watase Yasushige

2015-02-01

Full Text Available This article provides a formalized proof of the so-called “the four-square theorem”, namely any natural number can be expressed by a sum of four squares, which was proved by Lagrange in 1770. An informal proof of the theorem can be found in the number theory literature, e.g. in [14], [1] or [23].
Geometry, rigidity, and group actions

CERN Document Server

Farb, Benson; Zimmer, Robert J

2011-01-01

The study of group actions is more than a hundred years old but remains to this day a vibrant and widely studied topic in a variety of mathematic fields. A central development in the last fifty years is the phenomenon of rigidity, whereby one can classify actions of certain groups, such as lattices in semi-simple Lie groups. This provides a way to classify all possible symmetries of important spaces and all spaces admitting given symmetries. Paradigmatic results can be found in the seminal work of George Mostow, Gergory Margulis, and Robert J. Zimmer, among others.The p
Numerical algorithm for rigid body position estimation using the quaternion approach

Science.gov (United States)

Zigic, Miodrag; Grahovac, Nenad

2017-11-01

This paper deals with rigid body attitude estimation on the basis of the data obtained from an inertial measurement unit mounted on the body. The aim of this work is to present the numerical algorithm, which can be easily applied to the wide class of problems concerning rigid body positioning, arising in aerospace and marine engineering, or in increasingly popular robotic systems and unmanned aerial vehicles. Following the considerations of kinematics of rigid bodies, the relations between accelerations of different points of the body are given. A rotation matrix is formed using the quaternion approach to avoid singularities. We present numerical procedures for determination of the absolute accelerations of the center of mass and of an arbitrary point of the body expressed in the inertial reference frame, as well as its attitude. An application of the algorithm to the example of a heavy symmetrical gyroscope is presented, where input data for the numerical procedure are obtained from the solution of differential equations of motion, instead of using sensor measurements.
Rigidity, Chaos and Integration: Hemispheric Interaction and Individual Differences in Metaphor Comprehension

Directory of Open Access Journals (Sweden)

Miriam eFaust

2014-07-01

Full Text Available Neurotypical individuals cope flexibly with the full range of semantic relations expressed in human language, including metaphoric relations. This impressive semantic ability may be associated with distinct and flexible patterns of hemispheric interaction, including higher right hemisphere (RH involvement for processing novel metaphors. However, this ability may be impaired in specific clinical conditions, such as Asperger syndrome and schizophrenia. The impaired semantic processing is accompanied by different patterns of hemispheric interaction during semantic processing, showing either reduced (in Asperger or excessive (in schizophrenia RH involvement. This paper interprets these individual differences using the terms Rigidity, Chaos and Integration, which describe patterns of semantic memory network states that either lead to semantic well-being or are disruptive of it. We argue that these semantic network states lie on a rigidity-chaos semantic continuum. We define these terms via network science terminology and provide network, cognitive and neural evidence to support our claim. This continuum includes LH hyper-rigid semantic memory state on one end (e.g., in persons with Asperger syndrome, and RH chaotic and over-flexible semantic memory state on the other end (e.g., in persons with schizophrenia. In between these two extremes lie different states of semantic memory structure which are related to individual differences in semantic creativity. We suggest that efficient semantic processing is achieved by semantic integration, a balance between semantic rigidity and semantic chaos. Such integration is achieved via intra-hemispheric communication. However, impairments to this well-balanced and integrated pattern of hemispheric interaction, e.g., when one hemisphere dominates the other, may lead to either semantic rigidity or semantic chaos, moving away from semantic integration and thus impairing the processing of metaphoric language.
Partial update least-square adaptive filtering

CERN Document Server

Xie, Bei

2014-01-01

Adaptive filters play an important role in the fields related to digital signal processing and communication, such as system identification, noise cancellation, channel equalization, and beamforming. In practical applications, the computational complexity of an adaptive filter is an important consideration. The Least Mean Square (LMS) algorithm is widely used because of its low computational complexity (O(N)) and simplicity in implementation. The least squares algorithms, such as Recursive Least Squares (RLS), Conjugate Gradient (CG), and Euclidean Direction Search (EDS), can converge faster a
Statistical thermodynamics of aligned rigid rods with attractive lateral interactions: Theory and Monte Carlo simulations

Science.gov (United States)

dos Santos, G. J.; Linares, D. H.; Ramirez-Pastor, A. J.

2018-04-01

The phase behaviour of aligned rigid rods of length k (k-mers) adsorbed on two-dimensional square lattices has been studied by Monte Carlo (MC) simulations and histogram reweighting technique. The k-mers, containing k identical units (each one occupying a lattice site) were deposited along one of the directions of the lattice. In addition, attractive lateral interactions were considered. The methodology was applied, particularly, to the study of the critical point of the condensation transition occurring in the system. The process was monitored by following the fourth order Binder cumulant as a function of temperature for different lattice sizes. The results, obtained for k ranging from 2 to 7, show that: (i) the transition coverage exhibits a decreasing behaviour when it is plotted as a function of the k-mer size and (ii) the transition temperature, Tc, exhibits a power law dependence on k, Tc ∼k 0 , 4, shifting to higher values as k increases. Comparisons with an analytical model based on a generalization of the Bragg-Williams approximation (BWA) were performed in order to support the simulation technique. A significant qualitative agreement was obtained between BWA and MC results.
Patient satisfaction related to rigid external distraction osteogenesis

NARCIS (Netherlands)

van Eggermont, Bas; Jansma, J.; Bierman, M. W. J.; Stegenga, B.

2007-01-01

The aim of this study was to evaluate satisfaction with treatment among cleft lip and palate patients who underwent maxillary advancement using a rigid external distraction (RED) device. Nine patients (four boys, five girls), mean age 17.7 years (SD 4.0), were included in the study. Outcome measures
Short Communication: Statistical determination of the rigidity in ...

African Journals Online (AJOL)

From the graph of load against displacement, the rigidity in flexion at different moisture levels was determined from which the Young modulus was calculated. Linear regression models were fitted to the data and the results showed significant correlation coefficients between the Young modulus and moisture content for each ...
Optimized imaging using non-rigid registration

International Nuclear Information System (INIS)

Berkels, Benjamin; Binev, Peter; Blom, Douglas A.; Dahmen, Wolfgang; Sharpley, Robert C.; Vogt, Thomas

2014-01-01

The extraordinary improvements of modern imaging devices offer access to data with unprecedented information content. However, widely used image processing methodologies fall far short of exploiting the full breadth of information offered by numerous types of scanning probe, optical, and electron microscopies. In many applications, it is necessary to keep measurement intensities below a desired threshold. We propose a methodology for extracting an increased level of information by processing a series of data sets suffering, in particular, from high degree of spatial uncertainty caused by complex multiscale motion during the acquisition process. An important role is played by a non-rigid pixel-wise registration method that can cope with low signal-to-noise ratios. This is accompanied by formulating objective quality measures which replace human intervention and visual inspection in the processing chain. Scanning transmission electron microscopy of siliceous zeolite material exhibits the above-mentioned obstructions and therefore serves as orientation and a test of our procedures. - Highlights: • Developed a new process for extracting more information from a series of STEM images. • An objective non-rigid registration process copes with distortions. • Images of zeolite Y show retrieval of all information available from the data set. • Quantitative measures of registration quality were implemented. • Applicable to any serially acquired data, e.g. STM, AFM, STXM, etc

The inverse square law of gravitation

International Nuclear Information System (INIS)

Cook, A.H.

1987-01-01

The inverse square law of gravitation is very well established over the distances of celestial mechanics, while in electrostatics the law has been shown to be followed to very high precision. However, it is only within the last century that any laboratory experiments have been made to test the inverse square law for gravitation, and all but one has been carried out in the last ten years. At the same time, there has been considerable interest in the possibility of deviations from the inverse square law, either because of a possible bearing on unified theories of forces, including gravitation or, most recently, because of a possible additional fifth force of nature. In this article the various lines of evidence for the inverse square law are summarized, with emphasis upon the recent laboratory experiments. (author)
Vertebral Column Resection for Rigid Spinal Deformity.

Science.gov (United States)

Saifi, Comron; Laratta, Joseph L; Petridis, Petros; Shillingford, Jamal N; Lehman, Ronald A; Lenke, Lawrence G

2017-05-01

Broad narrative review. To review the evolution, operative technique, outcomes, and complications associated with posterior vertebral column resection. A literature review of posterior vertebral column resection was performed. The authors' surgical technique is outlined in detail. The authors' experience and the literature regarding vertebral column resection are discussed at length. Treatment of severe, rigid coronal and/or sagittal malalignment with posterior vertebral column resection results in approximately 50-70% correction depending on the type of deformity. Surgical site infection rates range from 2.9% to 9.7%. Transient and permanent neurologic injury rates range from 0% to 13.8% and 0% to 6.3%, respectively. Although there are significant variations in EBL throughout the literature, it can be minimized by utilizing tranexamic acid intraoperatively. The ability to correct a rigid deformity in the spine relies on osteotomies. Each osteotomy is associated with a particular magnitude of correction at a single level. Posterior vertebral column resection is the most powerful posterior osteotomy method providing a successful correction of fixed complex deformities. Despite meticulous surgical technique and precision, this robust osteotomy technique can be associated with significant morbidity even in the most experienced hands.
MRS2016: Rigid Moon Rotation Series in the Relativistic Approximation

Science.gov (United States)

Pashkevich, V. V.

2017-03-01

The rigid Moon rotation problem is studied for the relativistic (kinematical) case, in which the geodetic perturbations in the Moon rotation are taken into account. As the result of this research the high-precision Moon Rotation Series MRS2016 in the relativistic approximation was constructed for the first time and the discrepancies between the high-precision numerical and the semi-analytical solutions of the rigid Moon rotation were investigated with respect to the fixed ecliptic of epoch J2000, by the numerical and analytical methods. The residuals between the numerical solution and MRS2016 in the perturbing terms of the physical librations do not exceed 80 mas and 10 arc seconds over 2000 and 6000 years, respectively.
First Case of Glufosinate-Resistant Rigid Ryegrass (Lolium rigidum Gaud. in Greece

Directory of Open Access Journals (Sweden)

Ilias S. Travlos

2018-03-01

Full Text Available Repeated applications of the same herbicide(s, which are characterized by the same mode of action, increase selection pressure, which in turn favours the evolution of herbicide-resistant weeds. Glufosinate is a broad-spectrum non-selective herbicide being used for weed control for many years around the world. Rigid ryegrass (Lolium rigidum Gaud. is an economically important grass weed in Greece. Recent complaints by growers about control failure of rigid ryegrass with glufosinate require further investigation and have been the basis of this study. The objectives of this study were to confirm the existence of glufosinate-resistant L. rigidum in Greece and evaluate the effect of L. rigidum growth stage on glufosinate efficacy. Twenty populations of rigid ryegrass from Greece were sampled from five regions, and whole plant dose–response studies were conducted for five populations under controlled conditions with eight rates of glufosinate (0.0, 0.098, 0.187, 0.375, 0.75, 1.5, 3.0, and 6.0 kg a.i. ha−1. Glufosinate resistance was confirmed in three out of five populations with the level of resistance ranging from three-to seven-fold compared with the susceptible populations based on above-ground biomass reduction. Results also revealed that the level of glufosinate-resistance of rigid ryegrass was dependent on the growth stage at which it was applied.
Rigid aromatic linking moiety in cationic lipids for enhanced gene transfection efficiency.

Science.gov (United States)

Wang, Bing; Zhao, Rui-Mo; Zhang, Ji; Liu, Yan-Hong; Huang, Zheng; Yu, Qing-Ying; Yu, Xiao-Qi

2017-08-18

Although numerous cationic lipids have been developed as non-viral gene vectors, the structure-activity relationship (SAR) of these materials remains unclear and needs further investigation. In this work, a series of lysine-derived cationic lipids containing linkages with different rigidity were designed and synthesized. SAR studies showed that lipids with rigid aromatic linkage could promote the formation of tight liposomes and enhance DNA condensation, which is essential for the gene delivery process. These lipids could give much higher transfection efficiency than those containing more flexible aliphatic linkage in various cell lines. Moreover, the rigid aromatic linkage also affords the material higher serum tolerance ability. Flow cytometry assay revealed that the target lipids have good cellular uptake, while confocal microscopy observation showed weaker endosome escape than Lipofectamine 2000. To solve such problem and further increase the transfection efficiency, some lysosomotropic reagents were used to improve the endosome escape of lipoplex. As expected, higher transfection efficiency than Lipofectamine 2000 could be obtained via this strategy. Cytotoxicity assay showed that these lipids have lower toxicity in various cell lines than Lipofectamine 2000, suggesting their potential for further application. This work demonstrates that a rigid aromatic linkage might distinctly improve the gene transfection abilities of cationic lipids and affords information to construct safe and efficient gene vector towards practical application. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Positive solution of non-square fully Fuzzy linear system of equation in general form using least square method

Directory of Open Access Journals (Sweden)

Reza Ezzati

2014-08-01

Full Text Available In this paper, we propose the least square method for computing the positive solution of a non-square fully fuzzy linear system. To this end, we use Kaffman' arithmetic operations on fuzzy numbers \\cite{17}. Here, considered existence of exact solution using pseudoinverse, if they are not satisfy in positive solution condition, we will compute fuzzy vector core and then we will obtain right and left spreads of positive fuzzy vector by introducing constrained least squares problem. Using our proposed method, non-square fully fuzzy linear system of equations always has a solution. Finally, we illustrate the efficiency of proposed method by solving some numerical examples.
Effect of graded inclusion of dietary soybean meal on nutrient digestibility, health, and metabolic indices of adult dogs.

Science.gov (United States)

Menniti, M F; Davenport, G M; Shoveller, A K; Cant, J P; Osborne, V R

2014-05-01

Two studies were conducted using adult dogs to evaluate the effect of increasing the inclusion of soybean meal (SBM) in an adult dog food on body composition, hematological and biochemical blood analyses, and total tract nutrient digestibility. Nutritionally complete and balanced diets were formulated with commercial-grade SBM (48% CP) to replace 0, 10, 20, or 30% of the protein provided by dried chicken protein resulting in final SBM inclusion of 0, 6.0, 11.5, and 17.0% (as-fed basis), respectively. In study 1, diets were fed during a 24-wk feeding trial using 36 female (spayed), adult hounds to evaluate food intake, BW, body composition, and blood measurements. There were no diet-related differences in food intake or BW. Body composition responded in a quadratic manner to increased dietary SBM inclusion with the percentage (%) of lean mass responding positively (P dogs. Serum concentrations of C-reactive protein and IGF-1 were similar among diets. In study 2, diets were evaluated in a digestibility study using 12 adult dogs in a 4 × 4 Latin square design. Increased SBM inclusion was associated with linear increases in the digestibility of CP (P dogs.
Single-particle inclusive spectra of charged particles in anti- pp-interactions at 22.4 GeV/c

International Nuclear Information System (INIS)

Boos, E.G.; Samojlov, V.V.; Takibaev, Zh.S.

1976-01-01

The inclusive spectra for inelastic anti-pp-interactions are investigated. Distributions of the transverse momentum squared for negative and positive particles as well as for identified protons have been obtained. The missing mass-squared distributions to the identified protons have been determined for different topologies of the experiment. The rapidity and target fragmentation cross-sections distributions have been obtained for the anti-pp → π - (π + )+X reactions in the center-of-mass-system. Average characteristics of the transverse momentum distribution show similar features as well as those obtained at higher than 22.4 GeV/c elsewhere. The upper limit of the antiproton diffraction dissociation cross section is 3.68+-0.45 mb. In the central region a charge asymmetry has been observed, the asymmetry parameter being equal to 0.15+-0.01
Non-rigid ultrasound image registration using generalized relaxation labeling process

Science.gov (United States)

Lee, Jong-Ha; Seong, Yeong Kyeong; Park, MoonHo; Woo, Kyoung-Gu; Ku, Jeonghun; Park, Hee-Jun

2013-03-01

This research proposes a novel non-rigid registration method for ultrasound images. The most predominant anatomical features in medical images are tissue boundaries, which appear as edges. In ultrasound images, however, other features can be identified as well due to the specular reflections that appear as bright lines superimposed on the ideal edge location. In this work, an image's local phase information (via the frequency domain) is used to find the ideal edge location. The generalized relaxation labeling process is then formulated to align the feature points extracted from the ideal edge location. In this work, the original relaxation labeling method was generalized by taking n compatibility coefficient values to improve non-rigid registration performance. This contextual information combined with a relaxation labeling process is used to search for a correspondence. Then the transformation is calculated by the thin plate spline (TPS) model. These two processes are iterated until the optimal correspondence and transformation are found. We have tested our proposed method and the state-of-the-art algorithms with synthetic data and bladder ultrasound images of in vivo human subjects. Experiments show that the proposed method improves registration performance significantly, as compared to other state-of-the-art non-rigid registration algorithms.
Mathematical Construction of Magic Squares Utilizing Base-N Arithmetic

Science.gov (United States)

O'Brien, Thomas D.

2006-01-01

Magic squares have been of interest as a source of recreation for over 4,500 years. A magic square consists of a square array of n[squared] positive and distinct integers arranged so that the sum of any column, row, or main diagonal is the same. In particular, an array of consecutive integers from 1 to n[squared] forming an nxn magic square is…
Comparison and Implementation of a Rigid and a Flexible Multibody Planetary Gearbox Model

DEFF Research Database (Denmark)

Jørgensen, Martin Felix; Pedersen, Niels Leergaard; Sørensen, Jens Nørkær

2014-01-01

We propose algorithms for developing (1) a rigid (constrained) and (2) a flexible planetary gearbox model. The two methods are compared against each other and advantages/disadvantages of each method are discussed. The rigid model (1) has gear tooth reaction forces expressed by Lagrange multipliers...... between one and two gear teeth in mesh. The final results are from modelling the planetary gearbox in a 500 kW wind turbine which we also described in Jørgensen et al. (2013)........ The flexible approach (2) is being compared with the gear tooth forces from the rigid approach, first without damping and second the influence of damping is examined. Variable stiffness as a function of base circle arc length is implemented in the flexible approach such that it handles the realistic switch...
Student understanding of the application of Newton's second law to rotating rigid bodies

Science.gov (United States)

Close, Hunter G.; Gomez, Luanna S.; Heron, Paula R. L.

2013-06-01

We report on an investigation of student understanding of rigid body dynamics in which we asked students in introductory calculus-based physics to compare the translational motions of identical rigid bodies subject to forces that differed only in the point of contact at which they were applied. There was a widespread tendency to claim that forces that cause rotational motion have a diminished effect on translational motion. A series of related problems was developed to examine whether similar errors would be made in other contexts, and interviews were conducted to probe student thinking in greater depth. In this paper, we describe the results of our investigation and also describe a series of different interventions that culminated in the development of a tutorial that improves student ability to apply Newton's second law to rotating rigid bodies.
Technical characteristics of rigid sprayed PUR and PIR foams used in construction industry

Science.gov (United States)

Gravit, Marina; Kuleshin, Aleksey; Khametgalieva, Elina; Karakozova, Irina

2017-10-01

The article describes the distinctive properties of rigid polyurethane foam and polyisocyanurate (PUR and PIR). A brief review of the research was carried out on their modification with an objective to improve the thermal insulation properties and reducing the combustibility. A comparative analysis of the technical characteristics of rigid PUR and PIR foams of various manufacturers is presented. The problems of the state of the market for the production of polyurethane foam and polyisocyanurate in Russia have been marked. It is established that the further development of the fabrication technology of heat-insulating sprayed rigid PUR and PIR foams requires uniformity of technical characteristics of original components and finished products. Moreover, it requires the creation of unified information base for raw materials and auxiliary materials used in the production of PUR and PIR foam.
Crack identification for rigid pavements using unmanned aerial vehicles

Science.gov (United States)

Bahaddin Ersoz, Ahmet; Pekcan, Onur; Teke, Turker

2017-09-01

Pavement condition assessment is an essential piece of modern pavement management systems as rehabilitation strategies are planned based upon its outcomes. For proper evaluation of existing pavements, they must be continuously and effectively monitored using practical means. Conventionally, truck-based pavement monitoring systems have been in-use in assessing the remaining life of in-service pavements. Although such systems produce accurate results, their use can be expensive and data processing can be time consuming, which make them infeasible considering the demand for quick pavement evaluation. To overcome such problems, Unmanned Aerial Vehicles (UAVs) can be used as an alternative as they are relatively cheaper and easier-to-use. In this study, we propose a UAV based pavement crack identification system for monitoring rigid pavements’ existing conditions. The system consists of recently introduced image processing algorithms used together with conventional machine learning techniques, both of which are used to perform detection of cracks on rigid pavements’ surface and their classification. Through image processing, the distinct features of labelled crack bodies are first obtained from the UAV based images and then used for training of a Support Vector Machine (SVM) model. The performance of the developed SVM model was assessed with a field study performed along a rigid pavement exposed to low traffic and serious temperature changes. Available cracks were classified using the UAV based system and obtained results indicate it ensures a good alternative solution for pavement monitoring applications.
Rigid Body Energy Minimization on Manifolds for Molecular Docking.

Science.gov (United States)

Mirzaei, Hanieh; Beglov, Dmitri; Paschalidis, Ioannis Ch; Vajda, Sandor; Vakili, Pirooz; Kozakov, Dima

2012-11-13

Virtually all docking methods include some local continuous minimization of an energy/scoring function in order to remove steric clashes and obtain more reliable energy values. In this paper, we describe an efficient rigid-body optimization algorithm that, compared to the most widely used algorithms, converges approximately an order of magnitude faster to conformations with equal or slightly lower energy. The space of rigid body transformations is a nonlinear manifold, namely, a space which locally resembles a Euclidean space. We use a canonical parametrization of the manifold, called the exponential parametrization, to map the Euclidean tangent space of the manifold onto the manifold itself. Thus, we locally transform the rigid body optimization to an optimization over a Euclidean space where basic optimization algorithms are applicable. Compared to commonly used methods, this formulation substantially reduces the dimension of the search space. As a result, it requires far fewer costly function and gradient evaluations and leads to a more efficient algorithm. We have selected the LBFGS quasi-Newton method for local optimization since it uses only gradient information to obtain second order information about the energy function and avoids the far more costly direct Hessian evaluations. Two applications, one in protein-protein docking, and the other in protein-small molecular interactions, as part of macromolecular docking protocols are presented. The code is available to the community under open source license, and with minimal effort can be incorporated into any molecular modeling package.
Centrifuge modelling of rigid piles in soft clay

DEFF Research Database (Denmark)

Klinkvort, R.T.; Poder, M.; Truong, P.

2016-01-01

of this study is to employ centrifuge modelling in order to derive experimental p-y curves for rigid piles embedded in over-consolidated soft clay. A kaolin clay sample was prepared and pre-consolidated by applying a constant pressure at the soil surface, while different over-consolidation ratios were achieved...
Anti-synchronization of the rigid body exhibiting chaotic dynamics ...

African Journals Online (AJOL)

Based on a method derived from nonlinear control theory, we present a ... In this framework, the active control technique is modified and employed to design control ... state space of the two rigid bodies was verified by numerical simulations.
Therapeutic rigid bronchoscopy at a tertiary care center in North India: Initial experience and systematic review of Indian literature

Directory of Open Access Journals (Sweden)

Karan Madan

2014-01-01

Full Text Available Background and Aim: Rigid bronchoscopy is often an indispensable procedure in the therapeutic management of a wide variety of tracheobronchial disorders. However, it is performed at only a few centers in adult patients in India. Herein, we report our initial 1-year experience with this procedure. Materials and Methods: A prospective observational study on the indications, outcomes, and safety of various rigid bronchoscopy procedures performed between November 2009 and October 2010. Improvement in dyspnea, cough, and the overall quality of life was recorded on a visual analog scale from 0 to 100 mm. A systematic review of PubMed was performed to identify studies reporting the use of rigid bronchoscopy from India. Results: Thirty-eight rigid bronchoscopies (50 procedures were performed in 19 patients during the study period. The commonest indication was benign tracheal stenosis followed by central airway tumor, and the procedures performed were rigid bronchoplasty, tumor debulking, and stent placement. The median procedure duration was 45 (range, 30-65 min. There was significant improvement in quality of life associated with therapeutic rigid bronchoscopy. Minor procedural complications were encountered in 18 bronchoscopies, and there was no procedural mortality. The systematic review identified 15 studies, all on the role of rigid bronchoscopy in foreign body removal. Conclusions: Rigid bronchoscopy is a safe and effective modality for treatment of a variety of tracheobronchial disorders. There is a dire need of rigid bronchoscopy training at teaching hospitals in India.
Experiment and numerical simulation on the characteristics of fluid–structure interactions of non-rigid airships

Directory of Open Access Journals (Sweden)

Xiaocui Wu

2015-11-01

Full Text Available Fluid–structure interaction is an important issue for non-rigid airships with inflated envelopes. In this study, a wind tunnel test is conducted, and a loosely coupled procedure is correspondingly established for numerical simulation based on computational fluid dynamics and nonlinear finite element analysis methods. The typical results of the numerical simulation and wind tunnel experiment, including the overall lift and deformation, are in good agreement with each other. The results obtained indicate that the effect of fluid–structure interaction is noticeable and should be considered for non-rigid airships. Flow-induced deformation can further intensify the upward lift force and pitching moment, which can lead to a large deformation. Under a wind speed of 15 m/s, the lift force of the non-rigid model is increased to approximately 60% compared with that of the rigid model under a high angle of attack.
Delayed ripple counter simplifies square-root computation

Science.gov (United States)

Cliff, R.

1965-01-01

Ripple subtract technique simplifies the logic circuitry required in a binary computing device to derive the square root of a number. Successively higher numbers are subtracted from a register containing the number out of which the square root is to be extracted. The last number subtracted will be the closest integer to the square root of the number.

Unevenness of Sliding Surface of Overhead Rigid Conductor Lines and Method for Reducing Unevenness

Science.gov (United States)

Aboshi, Mitsuo; Shimizu, Masashi

Rigid conductor lines are used in many subways, because the use of such conductor lines reduces the risk of accidents and because less space is required for their installation. However, as the unevenness of the sliding surface of the rigid conductor lines significantly influences the fluctuations in the contact force between pantographs and contact lines, it is necessary to decrease the unevenness at the construction as well as the maintenance stages. In order to investigate the installation accuracy of overhead rigid conductor lines, we have developed a device that accurately and continuously measures the unevenness of the sliding surface. By using this measuring device, we have confirmed that the unevenness of the sliding surface depends on various factors such as the sag between the support points, the deformation of the aluminum base or the conductive rail in the case of a long wavelength, the slight sagging unevenness between the bolts of the long ear, the undulating wear etc. This paper describes the actual unevenness conditions and the technical methods for decreasing the unevenness of the sliding surface of overhead rigid conductor lines.
PRICE RIGIDITY AND MONETARY NON-NEUTRALITY IN DEVELOPING COUNTRIES: EVIDENCE FROM NIGERIA

Directory of Open Access Journals (Sweden)

Nathaniel E. Urama

2013-04-01

Full Text Available In an attempt to find out the degree of monetary non-neutrality in Nigeria we started from finding out the size of price rigidity in the country. Computation with Ball and Romer method showed that price rigidity is optimal decision for firms in Nigeria only when the menu cost is well above 2.28% of the firm’s revenue which is on the high side, showing the likelihood of weak price rigidity in the country. Confirming this, the IRFs of the SVAR shows that the response of inflation to nominal shock has only one period lag. These combined results led to a small though persistent response of output to the nominal shock. The result of the study therefore points towards large nominal and small real effect of monetary policy in Nigeria and conclude that monetary policy will be a better option for contractionary plan but not for an expansionary plan.
Vertical bending strength and torsional rigidity analysis of formula student car chassis

Science.gov (United States)

Hazimi, Hashfi; Ubaidillah, Setiyawan, Adi Eka Putra; Ramdhani, Hanief Cahya; Saputra, Murnanda Zaesy; Imaduddin, Fitrian

2018-02-01

Formula Society of Automotive Engineers (FSAE) is a competition for students to construct formula student car. One of an essential part of a formula student car is its chassis. Chassis is an internal vehicle frame which holds all another part of the vehicle and secures the driver. The team have to design their chassis and tests their design to achieve the best chassis that fulfill the regulation. This paper contains chassis design from Bengawan FSAE Team and some FEA tests to find out the Tensile Strength, Torsional Rigidity, and Von Misses Stress of Formula SAE car. Torsional rigidity was found by applying the static torsional test. The results from torsional rigidity test are a maximum deformation of 9.9512 mm with 1.7064 safety factor, and 35.935 MPa maximum Von Misses Stress. Moreover, then the result of the vertical bending strength test is 8.1214 mm max deformation with safety factor 4.2717, and 29.226 MPa maximum Von Misses Stress.
Inclusive and semi-inclusive analysis from polarised deep-inelastic muon scattering

International Nuclear Information System (INIS)

Kageya, T.

1999-01-01

We present new results for the spin-dependent structure function on the proton and for the polarised quark distributions in the nucleon from semi-inclusive spin asymmetries. With the inclusive asymmetry from deep inelastic scattering of polarised muons on polarised protons, it is found that the Ellis-Jaffe sum rule is violated. Using our results for Γ d 1 , the Bjorken sum rule is confirmed with an accuracy of about 15%. From semi-inclusive spin asymmetries and SMC inclusive spin asymmetries, we determine the polarised quark distributions of valence u and d quarks to be positive and negative, respectively, while the non-strange sea distribution to be consistent with zero
Rigidity theorem for Willmore surfaces in a sphere

Indian Academy of Sciences (India)

(Math. Sci.) Vol. 126, No. 2, May 2016, pp. 253–260. c Indian Academy of Sciences. Rigidity theorem for Willmore surfaces in a sphere. HONGWEI XU1 and DENGYUN YANG2,∗. 1Center of Mathematical Sciences, Zhejiang University, Hangzhou 310027,. People's Republic of China. 2College of Mathematics and ...
Simplified neural networks for solving linear least squares and total least squares problems in real time.

Science.gov (United States)

Cichocki, A; Unbehauen, R

1994-01-01

In this paper a new class of simplified low-cost analog artificial neural networks with on chip adaptive learning algorithms are proposed for solving linear systems of algebraic equations in real time. The proposed learning algorithms for linear least squares (LS), total least squares (TLS) and data least squares (DLS) problems can be considered as modifications and extensions of well known algorithms: the row-action projection-Kaczmarz algorithm and/or the LMS (Adaline) Widrow-Hoff algorithms. The algorithms can be applied to any problem which can be formulated as a linear regression problem. The correctness and high performance of the proposed neural networks are illustrated by extensive computer simulation results.
Rigidity and bradykinesia reduce interlimb coordination in Parkinsonian gait

NARCIS (Netherlands)

Winogrodzka, Ania; Wagenaar, Robert C.; Booij, Jan; Wolters, Eric C.

2005-01-01

Objective: To assess the influence of rigidity and bradykinesia and the extent of dopaminergic degeneration on interlimb coordination during walking in early, drug-naive patients with Parkinson's disease (PD). Design: The interlimb coordination was examined during a systematic manipulation of
Coupling characteristics of rigid body motion and elastic deformation of a 3-PRR parallel manipulator with flexible links

International Nuclear Information System (INIS)

Zhang Xuping; Mills, James K.; Cleghorn, William L.

2009-01-01

Modeling of multibody dynamics with flexible links is a challenging task, which not only involves the effect of rigid body motion on elastic deformations, but also includes the influence of elastic deformations on rigid body motion. This paper presents coupling characteristics of rigid body motions and elastic motions of a 3-PRR parallel manipulator with three flexible intermediate links. The intermediate links are modeled as Euler-Bernoulli beams with pinned-pinned boundary conditions based on the assumed mode method (AMM). Using Lagrange multipliers, the fully coupled equations of motions of the flexible parallel manipulator are developed by incorporating the rigid body motions with elastic motions. The mutual dependence of elastic deformations and rigid body motions are investigated from the analysis of the derived equations of motion. Open-loop simulation without joint motion controls and closed-loop simulation with joint motion controls are performed to illustrate the effect of elastic motion on rigid body motions and the coupling effect amongst flexible links. These analyses and results provide valuable insight to the design and control of the parallel manipulator with flexible intermediate links
Can deformation of a polymer film with a rigid coating model geophysical processes?

Science.gov (United States)

Volynskii, A. L.; Bazhenov, S. L.

2007-12-01

The structural and mechanical behavior of polymer films with a thin rigid coating is analyzed. The behavior of such systems under applied stress is accompanied by the formation of a regular wavy surface relief and by regular fragmentation of the coating. The above phenomena are shown to be universal. Both phenomena (stress-induced development of a regular wavy surface relief and regular fragmentation of the coating) are provided by the specific features of mechanical stress transfer from a compliant soft support to a rigid thin coating. The above phenomena are associated with a specific structure of the system, which is referred to as “a rigid coating on a soft substratum” system (RCSS). Surface microrelief in RCSS systems is similar to the ocean floor relief in the vicinity of mid-oceanic ridges. Thus, the complex system composed of a young oceanic crust and upper Earth's mantle may be considered as typically “a solid coating on a soft substratum” system. Specific features of the ocean floor relief are analyzed in terms of the approach advanced for the description of the structural mechanical behavior of polymer films with a rigid coating. This analysis allowed to estimate the strength of an ocean floor.
Inclusive pedagogy

DEFF Research Database (Denmark)

Korsgaard, Morten Timmermann; Skov Mortensen, Stig

This article will present a case for a shift in perspective in inclusive education research towards a continentally inspired approach. Drawing on the age old distinction between continental and Anglo-American educational research the aim is to flesh out what a shift to a continental approach...... will entail, and why it might be beneficial to research in inclusive education...
The Role of Rigidity in Adaptive and Maladaptive Families Assessed by FACES IV: The Points of View of Adolescents.

Science.gov (United States)

Everri, Marina; Mancini, Tiziana; Fruggeri, Laura

Previous studies using Olson's Circumplex Model and FACES IV, the self-report assessing family functioning, did not clarify the role of rigidity, a dimension of this model. Rigidity emerged as ambiguous: it was considered either as a functional or as a dysfunctional dimension. Building upon the results of previous studies, we provided a contribution intended to disambiguate the role of rigidity considering adolescents' perceptions and using a non-a priori classification analysis. 320 Italian adolescents (13-21 years) participated in this study and responded to a questionnaire containing scales of the study variables. A latent class analysis was performed to identify the association of rigidity with the other dimensions of Olson's model and with indicators of adaptive family functioning in adolescence: parental monitoring and family satisfaction. We found six clusters corresponding to family typologies and having different levels of functioning. Rigidity emerged as adaptive in the typologies named rigidly balanced and flexibly oscillating; it was associated with positive dimensions of family functioning, i.e. flexibility, cohesion, parental monitoring, and high levels of family satisfaction. Differently, when rigidity was associated with disengagement, low cohesion and flexibility, and lack of parental supervision, emerged as maladaptive. This was the case of two typologies: the rigidly disengaged and the chaotically disengaged. Adolescents of these families reported the lowest levels of satisfaction. In the two last typologies, the flexibly chaotic and the cohesively disorganized, rigidity indicated a mid-range functionality as these families were characterized by emotional connectedness but lack of containment. Clinical implications are discussed.
Tidal Evolution of Asteroidal Binaries. Ruled by Viscosity. Ignorant of Rigidity.

Science.gov (United States)

Efroimsky, Michael

2015-10-01

This is a pilot paper serving as a launching pad for study of orbital and spin evolution of binary asteroids. The rate of tidal evolution of asteroidal binaries is defined by the dynamical Love numbers kl divided by quality factors Q. Common in the literature is the (oftentimes illegitimate) approximation of the dynamical Love numbers with their static counterparts. Since the static Love numbers are, approximately, proportional to the inverse rigidity, this renders a popular fallacy that the tidal evolution rate is determined by the product of the rigidity by the quality factor: {k}l/Q\\propto 1/(μ Q). In reality, the dynamical Love numbers depend on the tidal frequency and all rheological parameters of the tidally perturbed body (not just rigidity). We demonstrate that in asteroidal binaries the rigidity of their components plays virtually no role in tidal friction and tidal lagging, and thereby has almost no influence on the intensity of tidal interactions (tidal torques, tidal dissipation, tidally induced changes of the orbit). A key quantity that overwhelmingly determines the tidal evolution is a product of the effective viscosity η by the tidal frequency χ . The functional form of the torque’s dependence on this product depends on who wins in the competition between viscosity and self-gravitation. Hence a quantitative criterion, to distinguish between two regimes. For higher values of η χ , we get {k}l/Q\\propto 1/(η χ ), {while} for lower values we obtain {k}l/Q\\propto η χ . Our study rests on an assumption that asteroids can be treated as Maxwell bodies. Applicable to rigid rocks at low frequencies, this approximation is used here also for rubble piles, due to the lack of a better model. In the future, as we learn more about mechanics of granular mixtures in a weak gravity field, we may have to amend the tidal theory with other rheological parameters, ones that do not show up in the description of viscoelastic bodies. This line of study provides
ANALYSIS OF A RIGID WALL IN AN ELASTIC WEIGHTY HALF-PLANE

Directory of Open Access Journals (Sweden)

K. V. Dmitrieva

2016-01-01

Full Text Available The analysis of stress-strain state of a rigid wall in an elastic weighty half-plane with a broken outline is carried out. To this end, the auxiliary problem of displacements definition in an elastic weighty quarter-plane was solved. Ritz method derived a formula to determine the displacements of elastic flat wedge boundaries in view of its own weight. On the basis of the received expressions the algorithm of displacements definition of a crack in an elastic weighty half-plane with a broken outline is developed. Analytical calculation of a rigid vertical wall located in an elastic weighty half-plane under the influence of a horizontal load, carried out by two methods: by Zhemochkin's method and finite difference method. In the problem statement an elastic half-plane is considered a model of the soil medium, therefore, only compressive normal stresses can arise on the connection of the wall with the elastic base. This assumption implies occurrence of discontinuities soil medium, and leads for the wall to an emergence of two dividing points of boundary conditions. The determination of the boundaries contact of the wall with the elastic half-plane, are not known in advance, is performed by iteratively way at each step set the position of dividing points of boundary conditions and the system of canonical equations of a corresponding method is written. If tensile stresses appear in wall-base contact and/or there is overlap of the crack edges occurs, then proceeds to the next iteration. Analysis of the results shows that the bending moment and shear forces in sections of the rigid wall in a broken weighty half-plane differ slightly from the same diagrams constructed for a rigid wall in an elastic weightless half-plane. The verification of the results of analytical calculation with the results received by using the LIRA 9.6 that implements the finite element method is obtained. The calculation results for the rigid wall in an elastic weighty half
Robust non-rigid point set registration using student's-t mixture model.

Directory of Open Access Journals (Sweden)

Zhiyong Zhou

Full Text Available The Student's-t mixture model, which is heavily tailed and more robust than the Gaussian mixture model, has recently received great attention on image processing. In this paper, we propose a robust non-rigid point set registration algorithm using the Student's-t mixture model. Specifically, first, we consider the alignment of two point sets as a probability density estimation problem and treat one point set as Student's-t mixture model centroids. Then, we fit the Student's-t mixture model centroids to the other point set which is treated as data. Finally, we get the closed-form solutions of registration parameters, leading to a computationally efficient registration algorithm. The proposed algorithm is especially effective for addressing the non-rigid point set registration problem when significant amounts of noise and outliers are present. Moreover, less registration parameters have to be set manually for our algorithm compared to the popular coherent points drift (CPD algorithm. We have compared our algorithm with other state-of-the-art registration algorithms on both 2D and 3D data with noise and outliers, where our non-rigid registration algorithm showed accurate results and outperformed the other algorithms.
Rigidity percolation in dispersions with a structured viscoelastic matrix

NARCIS (Netherlands)

Wilbrink, M.W.L.; Michels, M.A.J.; Vellinga, W.P.; Meijer, H.E.H.

2005-01-01

This paper deals with rigidity percolation in composite materials consisting of a dispersion of mineral particles in a microstructured viscoelastic matrix. The viscoelastic matrix in this specific case is a hydrocarbon refinery residue. In a set of model random composites the mean interparticle
The Square Light Clock and Special Relativity

Science.gov (United States)

Galli, J. Ronald; Amiri, Farhang

2012-01-01

A thought experiment that includes a square light clock is similar to the traditional vertical light beam and mirror clock, except it is made up of four mirrors placed at a 45[degree] angle at each corner of a square of length L[subscript 0], shown in Fig. 1. Here we have shown the events as measured in the rest frame of the square light clock. By…
Properties of the histogram location approach and the extent and change of downward nominal wage rigidity in the EU

Directory of Open Access Journals (Sweden)

Andreas Behr

2006-06-01

Full Text Available The histogram location approach has been proposed by Kahn (1997 to estimate the fraction of wage cuts prevented by downward nominal wage rigidity. In this paper, we analyze the validity of the approach by means of a simulation study which yielded evidence of unbiasedness but also of potential underestimation of rigidity parameter uncertainty and therefore of potential anticonservative inference. We apply the histogram location approach to estimate the extent of downward nominal wage rigidity across the EU for 1995-2001. Our data base is the User Data Base (UDB of the European Community Household Panel (ECHP. The results show wide variation in the fraction of wage cuts prevented by nominal wage rigidity across the EU. The lowest rigidity parameters are found for the UK, Spain and Ireland, the largest for Portugal and Italy. Analyzing the change of rigidity between sub periods 1995-1997 and 1999-2001 even shows an widening of the differences in nominal wage rigidity. Due to the finding of large differences across the EU, the results imply that the costs of low inflation policies across the EU differ substantially.
Role of Rigid Endoscopic Detorsion in the Management of Sigmoid ...

African Journals Online (AJOL)

had emergency surgery, with gangrenous bowel noted in 43 (72%) ... of any stable patient with clinical and radiological features ... peritonitis, underwent repeat rigid sigmoidoscopy. ... endoscopic detorsion was successful in all six cases.
High precision NC lathe feeding system rigid-flexible coupling model reduction technology

Science.gov (United States)

Xuan, He; Hua, Qingsong; Cheng, Lianjun; Zhang, Hongxin; Zhao, Qinghai; Mao, Xinkai

2017-08-01

This paper proposes the use of dynamic substructure method of reduction of order to achieve effective reduction of feed system for high precision NC lathe feeding system rigid-flexible coupling model, namely the use of ADAMS to establish the rigid flexible coupling simulation model of high precision NC lathe, and then the vibration simulation of the period by using the FD 3D damper is very effective for feed system of bolt connection reduction of multi degree of freedom model. The vibration simulation calculation is more accurate, more quickly.
Spectrum unfolding by the least-squares methods

International Nuclear Information System (INIS)

Perey, F.G.

1977-01-01

The method of least squares is briefly reviewed, and the conditions under which it may be used are stated. From this analysis, a least-squares approach to the solution of the dosimetry neutron spectrum unfolding problem is introduced. The mathematical solution to this least-squares problem is derived from the general solution. The existence of this solution is analyzed in some detail. A chi 2 -test is derived for the consistency of the input data which does not require the solution to be obtained first. The fact that the problem is technically nonlinear, but should be treated in general as a linear one, is argued. Therefore, the solution should not be obtained by iteration. Two interpretations are made for the solution of the code STAY'SL, which solves this least-squares problem. The relationship of the solution to this least-squares problem to those obtained currently by other methods of solving the dosimetry neutron spectrum unfolding problem is extensively discussed. It is shown that the least-squares method does not require more input information than would be needed by current methods in order to estimate the uncertainties in their solutions. From this discussion it is concluded that the proposed least-squares method does provide the best complete solution, with uncertainties, to the problem as it is understood now. Finally, some implications of this method are mentioned regarding future work required in order to exploit its potential fully

Elmo bumpy square plasma confinement device

Science.gov (United States)

Owen, L.W.

1985-01-01

The invention is an Elmo bumpy type plasma confinement device having a polygonal configuration of closed magnet field lines for improved plasma confinement. In the preferred embodiment, the device is of a square configuration which is referred to as an Elmo bumpy square (EBS). The EBS is formed by four linear magnetic mirror sections each comprising a plurality of axisymmetric assemblies connected in series and linked by 90/sup 0/ sections of a high magnetic field toroidal solenoid type field generating coils. These coils provide corner confinement with a minimum of radial dispersion of the confined plasma to minimize the detrimental effects of the toroidal curvature of the magnetic field. Each corner is formed by a plurality of circular or elliptical coils aligned about the corner radius to provide maximum continuity in the closing of the magnetic field lines about the square configuration confining the plasma within a vacuum vessel located within the various coils forming the square configuration confinement geometry.
Quantized kernel least mean square algorithm.

Science.gov (United States)

Chen, Badong; Zhao, Songlin; Zhu, Pingping; Príncipe, José C

2012-01-01

In this paper, we propose a quantization approach, as an alternative of sparsification, to curb the growth of the radial basis function structure in kernel adaptive filtering. The basic idea behind this method is to quantize and hence compress the input (or feature) space. Different from sparsification, the new approach uses the "redundant" data to update the coefficient of the closest center. In particular, a quantized kernel least mean square (QKLMS) algorithm is developed, which is based on a simple online vector quantization method. The analytical study of the mean square convergence has been carried out. The energy conservation relation for QKLMS is established, and on this basis we arrive at a sufficient condition for mean square convergence, and a lower and upper bound on the theoretical value of the steady-state excess mean square error. Static function estimation and short-term chaotic time-series prediction examples are presented to demonstrate the excellent performance.
Cohomological rigidity of manifolds defined by 3-dimensional polytopes

Science.gov (United States)

Buchstaber, V. M.; Erokhovets, N. Yu.; Masuda, M.; Panov, T. E.; Park, S.

2017-04-01

A family of closed manifolds is said to be cohomologically rigid if a cohomology ring isomorphism implies a diffeomorphism for any two manifolds in the family. Cohomological rigidity is established here for large families of 3-dimensional and 6-dimensional manifolds defined by 3-dimensional polytopes. The class \\mathscr{P} of 3-dimensional combinatorial simple polytopes P different from tetrahedra and without facets forming 3- and 4-belts is studied. This class includes mathematical fullerenes, that is, simple 3- polytopes with only 5-gonal and 6-gonal facets. By a theorem of Pogorelov, any polytope in \\mathscr{P} admits in Lobachevsky 3-space a right-angled realisation which is unique up to isometry. Our families of smooth manifolds are associated with polytopes in the class \\mathscr{P}. The first family consists of 3-dimensional small covers of polytopes in \\mathscr{P}, or equivalently, hyperbolic 3-manifolds of Löbell type. The second family consists of 6-dimensional quasitoric manifolds over polytopes in \\mathscr{P}. Our main result is that both families are cohomologically rigid, that is, two manifolds M and M' from either family are diffeomorphic if and only if their cohomology rings are isomorphic. It is also proved that if M and M' are diffeomorphic, then their corresponding polytopes P and P' are combinatorially equivalent. These results are intertwined with classical subjects in geometry and topology such as the combinatorics of 3-polytopes, the Four Colour Theorem, aspherical manifolds, a diffeomorphism classification of 6-manifolds, and invariance of Pontryagin classes. The proofs use techniques of toric topology. Bibliography: 69 titles.
Sets of Mutually Orthogonal Sudoku Latin Squares

Science.gov (United States)

Vis, Timothy; Petersen, Ryan M.

2009-01-01

A Latin square of order "n" is an "n" x "n" array using n symbols, such that each symbol appears exactly once in each row and column. A set of Latin squares is c ordered pairs of symbols appearing in the cells of the array are distinct. The popular puzzle Sudoku involves Latin squares with n = 9, along with the added condition that each of the 9…
Stabilization of Rigid Body Dynamics by Internal and External Torques

National Research Council Canada - National Science Library

Bloch, A. M; Krishnaprasad, P. S; Marsden, J. E; Sanchez de Alvarez, G

1990-01-01

...] with quadratic feedback torques for internal rotors. We show that with such torques, the equations for the rigid body with momentum wheels are Hamiltonian with respect to a Lie-Poisson bracket structure. Further...
Inclusion: Conceptualization and measurement

NARCIS (Netherlands)

Jansen, W.S.; Otten, S.; Van der Zee, K.I.; Jans, L.

2014-01-01

n the present research, we introduced a conceptual framework of inclusion and subsequently used this as a starting point to develop and validate a scale to measure perceptions of inclusion. Departing from existing work on inclusion and complementing this with theoretical insights from optimal
Inclusion : Conceptualization and measurement

NARCIS (Netherlands)

Jansen, Wiebren S.; Otten, Sabine; van der Zee, Karen I.; Jans, Lise

In the present research, we introduced a conceptual framework of inclusion and subsequently used this as a starting point to develop and validate a scale to measure perceptions of inclusion. Departing from existing work on inclusion and complementing this with theoretical insights from optimal
Inclusion: Conceptualization and measurement

NARCIS (Netherlands)

Jansens, Wiebren S.; Otten, Sabine; van der Zee, Karen; Jans, Lise

2014-01-01

In the present research, we introduced a conceptual framework of inclusion and subsequently used this as a starting point to develop and validate a scale to measure perceptions of inclusion. Departing from existing work on inclusion and complementing this with theoretical insights from optimal
On square-free edge colorings of graphs

DEFF Research Database (Denmark)

Barat, Janos; Varju, P.P.

2008-01-01

An edge coloring of a graph is called square-free, if the sequence of colors on certain walks is not a square, that is not of the form x(1,)...,x(m), x(1),...,x(m), for any m epsilon N. Recently, various classes of walks have been suggested to be considered in the above definition. We construct...... graphs, for which the minimum number of colors needed for a square-free coloring is different if the considered set of walks vary, solving a problem posed by Bre ar and Klav2ar. We also prove the following: if an edge coloring of G is not square-free (even in the most general sense), then the length...
[Doppler ultrasound evaluation of aortic insufficiency using half-pressure time. Absence of arterial rigidity influence].

Science.gov (United States)

Kalotka-Bratek, H; Drobinski, G; Klimczak, K; Busquet, P; Fraysse, J B; Bejean-Lebuisson, A; Grosgogeat, Y

1989-02-01

In 20 patients with pure aortic regurgitation we studied the relationship between the severity of regurgitation, as assessed haemodynamically by the percentage of leakage (%L), and the half-pressure (T 1/2 P) and half-velocity (T 1/2 V) times, as obtained from doppler aortic blood velocity curves, taking into account the rigidity of the systemic vascular circuit characterized by the pressure wave propagation velocity (PWPV). The systemic arterial circuit was supple in 14 patients (PWPV less than 7.5 m/sec) and rigid in 6 patients (PWPV greater than 7.5 m/sec). The regression slopes between %L and T 1/2 P and between %L and T 1/2 V were calculated with their confidence limits in the 14 patients with supple arteries. The 6 patients with rigid arteries fitted into this nomogram, thus demonstrating that systemic arterial rigidity makes no difference in the relationship between %L and doppler indices. The half-velocity and half-pressure times measured by doppler ultrasound were acquired from a velocity signal directly determined by the aortic regurgitation, without any detectable effect of vascular circuit rigidity. Being equivalent by nature to the signal decrease time constant, they are independent of the absolute protodiastolic value of diastolic pressure gradient or blood flow velocity. For this reason these two doppler parameters are reliable to evaluate the severity of aortic regurgitation.
All SQUARE

CERN Multimedia

1972-01-01

With the existing Systems for using the accelerated protons, it is possible to supply only one slow ejected beam (feeding the East Hall) and, at the same time, to have only a small percentage of the beam on an internal target (feeding the South Hall). The arrangement will be replaced by a new System called SQUARE (Semi- QUAdrupole Resonant Extraction) which will give greater flexibility in supplying the three areas.
[Non-rigid medical image registration based on mutual information and thin-plate spline].

Science.gov (United States)

Cao, Guo-gang; Luo, Li-min

2009-01-01

To get precise and complete details, the contrast in different images is needed in medical diagnosis and computer assisted treatment. The image registration is the basis of contrast, but the regular rigid registration does not satisfy the clinic requirements. A non-rigid medical image registration method based on mutual information and thin-plate spline was present. Firstly, registering two images globally based on mutual information; secondly, dividing reference image and global-registered image into blocks and registering them; then getting the thin-plate spline transformation according to the shift of blocks' center; finally, applying the transformation to the global-registered image. The results show that the method is more precise than the global rigid registration based on mutual information and it reduces the complexity of getting control points and satisfy the clinic requirements better by getting control points of the thin-plate transformation automatically.
Evidence on Inclusion

DEFF Research Database (Denmark)

Dyssegaard, Camilla Brørup; Larsen, Michael Søgaard

The purpose of this publication is to examine existing research on inclusion to identify strategies of inclusion that have generated positive effects. To do so it is necessary to understand the effect of the applied strategies. One approach, which is being discussed, is to use evidence to determine...... which methods have proven more effective than others. The desire to gain insight into research on inclusion forms the basis of the current systematic review. The task was to determine which strategies primary research has found to be most effective for inclusion purposes. We have solved this task...... by addressing the existing research with the following question: What is the effect of including children with special needs in mainstream teaching in basic school, and which of the applied educational methods have proved to have a positive effect?...
Matrix rigidity regulates cancer cell growth by modulating cellular metabolism and protein synthesis.

Directory of Open Access Journals (Sweden)

Robert W Tilghman

Full Text Available Tumor cells in vivo encounter diverse types of microenvironments both at the site of the primary tumor and at sites of distant metastases. Understanding how the various mechanical properties of these microenvironments affect the biology of tumor cells during disease progression is critical in identifying molecular targets for cancer therapy.This study uses flexible polyacrylamide gels as substrates for cell growth in conjunction with a novel proteomic approach to identify the properties of rigidity-dependent cancer cell lines that contribute to their differential growth on soft and rigid substrates. Compared to cells growing on more rigid/stiff substrates (>10,000 Pa, cells on soft substrates (150-300 Pa exhibited a longer cell cycle, due predominantly to an extension of the G1 phase of the cell cycle, and were metabolically less active, showing decreased levels of intracellular ATP and a marked reduction in protein synthesis. Using stable isotope labeling of amino acids in culture (SILAC and mass spectrometry, we measured the rates of protein synthesis of over 1200 cellular proteins under growth conditions on soft and rigid/stiff substrates. We identified cellular proteins whose syntheses were either preferentially inhibited or preserved on soft matrices. The former category included proteins that regulate cytoskeletal structures (e.g., tubulins and glycolysis (e.g., phosphofructokinase-1, whereas the latter category included proteins that regulate key metabolic pathways required for survival, e.g., nicotinamide phosphoribosyltransferase, a regulator of the NAD salvage pathway.The cellular properties of rigidity-dependent cancer cells growing on soft matrices are reminiscent of the properties of dormant cancer cells, e.g., slow growth rate and reduced metabolism. We suggest that the use of relatively soft gels as cell culture substrates would allow molecular pathways to be studied under conditions that reflect the different mechanical
Non-spill control squared cascade

International Nuclear Information System (INIS)

Kai, Tsunetoshi; Inoue, Yoshiya; Oya, Akio; Suemori, Nobuo.

1974-01-01

Object: To reduce a mixed loss thus enhancing separating efficiency by the provision of a simple arrangement wherein a reflux portion in a conventional spill control squared cascade is replaced by a special stage including centrifugal separators. Structure: Steps in the form of a square cascade, in which a plurality of centrifugal separators are connected by pipe lines, are accumulated in multistage fashion to form a squared cascade. Between the adjoining steps is disposed a special stage including a centrifugal separator which receives both lean flow from the upper step and rich flow from the lower step. The centrifugal separator in the special stage has its rich side connected to the upper step and its lean side connected to the lower step. Special stages are each disposed at the upper side of the uppermost step and at the lower side of the lowermost step. (Kamimura, M.)
Spontaneous breaking of N=2 to N=1 in rigid and local supersymmetric theories

CERN Document Server

Ferrara, Sergio; Porrati, Massimo

1996-01-01

We analyze the relation between rigid and local supersymmetric N=2 field theories, when half of the supersymmetries are spontaneously broken. In particular, we show that the recently found partial supersymmety breaking induced by electric and magnetic Fayet-Iliopoulos terms in rigid theories can be obtained by a suitable flat limit of previously constructed N=2 supergravity models with partial super-Higgs in the observable sector.
Method of control of machining accuracy of low-rigidity elastic-deformable shafts

Directory of Open Access Journals (Sweden)

Antoni Świć

Full Text Available The paper presents an analysis of the possibility of increasing the accuracy and stability of machining of low-rigidity shafts while ensuring high efficiency and economy of their machining. An effective way of improving the accuracy of machining of shafts is increasing their rigidity as a result of oriented change of the elastic-deformable state through the application of a tensile force which, combined with the machining force, forms longitudinal-lateral strains. The paper also presents mathematical models describing the changes of the elastic-deformable state resulting from the application of the tensile force. It presents the results of experimental studies on the deformation of elastic low-rigidity shafts, performed on a special test stand developed on the basis of a lathe. An estimation was made of the effectiveness of the method of control of the elastic-deformable state with the use, as the regulating effects, the tensile force and eccentricity. It was demonstrated that controlling the two parameters: tensile force and eccentricity, one can improve the accuracy of machining, and thus achieve a theoretically assumed level of accuracy.
Reconstruction of thin electromagnetic inclusions by a level-set method

International Nuclear Information System (INIS)

Park, Won-Kwang; Lesselier, Dominique

2009-01-01

In this contribution, we consider a technique of electromagnetic imaging (at a single, non-zero frequency) which uses the level-set evolution method for reconstructing a thin inclusion (possibly made of disconnected parts) with either dielectric or magnetic contrast with respect to the embedding homogeneous medium. Emphasis is on the proof of the concept, the scattering problem at hand being so far based on a two-dimensional scalar model. To do so, two level-set functions are employed; the first one describes location and shape, and the other one describes connectivity and length. Speeds of evolution of the level-set functions are calculated via the introduction of Fréchet derivatives of a least-square cost functional. Several numerical experiments on noiseless and noisy data as well illustrate how the proposed method behaves
Temporal changes in serum creatine kinase concentration and degree of muscle rigidity in 24 patients with neuroleptic malignant syndrome

Directory of Open Access Journals (Sweden)

Nisijima K

2013-06-01

Full Text Available Koichi Nisijima, Katutoshi ShiodaDepartment of Psychiatry, Jichi Medical University, Tochigi, JapanAbstract: Neuroleptic malignant syndrome (NMS is a dangerous adverse response to antipsychotic drugs. It is characterized by the four major clinical symptoms of hyperthermia, severe muscle rigidity, autonomic dysfunction, and altered mental state. Serum creatine kinase (CK elevation occurs in over 90% of NMS cases. In the present study, the detailed temporal changes in serum CK and degree of muscle rigidity, and the relationship between CK concentration and degree of muscle rigidity over the time course from fever onset, were evaluated in 24 affected patients. The results showed that serum CK peaked on day 2 after onset of fever and returned to within normal limits at day 12. Mild muscle rigidity was observed before the onset of fever in 17 of 24 cases (71%. Muscle rigidity was gradually exacerbated and worsened until day 4 after onset of fever. These findings confirm physicians' empirical understanding of serum CK concentrations and muscle rigidity in NMS based on data accumulated from numerous patients with the syndrome, and they indicate that serum CK may contribute to the early detection of NMS.Keywords: neuroleptic malignant syndrome, creatine kinase, muscle rigidity
Viscoelastic materials with anisotropic rigid particles: stress-deformation behavior

NARCIS (Netherlands)

Sagis, L.M.C.; Linden, van der E.

2001-01-01

In this paper we have derived constitutive equations for the stress tensor of a viscoelastic material with anisotropic rigid particles. We have assumed that the material has fading memory. The expressions are valid for slow and small deformations from equilibrium, and for systems that are nearly

Multiplier less high-speed squaring circuit for binary numbers

Science.gov (United States)

Sethi, Kabiraj; Panda, Rutuparna

2015-03-01

The squaring operation is important in many applications in signal processing, cryptography etc. In general, squaring circuits reported in the literature use fast multipliers. A novel idea of a squaring circuit without using multipliers is proposed in this paper. Ancient Indian method used for squaring decimal numbers is extended here for binary numbers. The key to our success is that no multiplier is used. Instead, one squaring circuit is used. The hardware architecture of the proposed squaring circuit is presented. The design is coded in VHDL and synthesised and simulated in Xilinx ISE Design Suite 10.1 (Xilinx Inc., San Jose, CA, USA). It is implemented in Xilinx Vertex 4vls15sf363-12 device (Xilinx Inc.). The results in terms of time delay and area is compared with both modified Booth's algorithm and squaring circuit using Vedic multipliers. Our proposed squaring circuit seems to have better performance in terms of both speed and area.
Rocking Rotation of a Rigid Disk Embedded in a Transversely Isotropic Half-Space

Directory of Open Access Journals (Sweden)

Seyed Ahmadi

2014-06-01

Full Text Available The asymmetric problem of rocking rotation of a circular rigid disk embedded in a finite depth of a transversely isotropic half-space is analytically addressed. The rigid disk is assumed to be in frictionless contact with the elastic half-space. By virtue of appropriate Green's functions, the mixed boundary value problem is written as a dual integral equation. Employing further mathematical techniques, the integral equation is reduced to a well-known Fredholm integral equation of the second kind. The results related to the contact stress distribution across the disk region and the equivalent rocking stiffness of the system are expressed in terms of the solution of the obtained Fredholm integral equation. When the rigid disk is located on the surface or at the remote boundary, the exact closed-form solutions are presented. For verification purposes, the limiting case of an isotropic half-space is considered and the results are verified with those available in the literature. The jump behavior in the results at the edge of the rigid disk for the case of an infinitesimal embedment is highlighted analytically for the first time. Selected numerical results are depicted for the contact stress distribution across the disk region, rocking stiffness of the system, normal stress, and displacement components along the radial axis. Moreover, effects of anisotropy on the rocking stiffness factor are discussed in detail.
Analysis of the Behaviour of Semi Rigid Steel End Plate Connections

Directory of Open Access Journals (Sweden)

Bahaz A.

2018-01-01

Full Text Available The analysis of steel-framed building structures with full strength beam to column joints is quite standard nowadays. Buildings utilizing such framing systems are widely used in design practice. However, there is a growing recognition of significant benefits in designing joints as partial strength/semi-rigid. The design of joints within this partial strength/semi-rigid approach is becoming more and more popular. This requires the knowledge of the full nonlinear moment-rotation behaviour of the joint, which is also a design parameter. The rotational behaviour of steel semi rigid connections can be studied using the finite element method for the following three reasons: i such models are inexpensive; ii they allow the understanding of local effects, which are difficult to measure accurately physically, and iii they can be used to generate extensive parametric studies. This paper presents a three-dimensional finite element model using ABAQUS software in order to identify the effect of different parameters on the behaviour of semi rigid steel beam to column end plate connections. Contact and sliding between different elements, bolt pretension and geometric and material non-linearity are included in this model. A parametric study is conducted using a model of two end-plate configurations: flush and extended end plates. The studied parameters were as follows: bolts type, end plate thickness and column web stiffener. Then, the model was calibrated and validated with experimental results taken from the literature and with the model proposed by Eurocode3. The procedure for determining the moment–rotation curve using finite element analysis is also given together with a brief explanation of how the design moment resistance and the initial rotational stiffness of the joint are obtained.
Footstep towards Inclusive Education

Science.gov (United States)

Abbas, Faiza; Zafar, Aneeka; Naz, Tayyaba

2016-01-01

Inclusive education is a rising trend in the world. The first step towards inclusive education is providing the awareness to the general education teachers. This study focused to investigate the general education teachers of primary and secondary level awareness about the special education and inclusive education. This study is descriptive method…
More Policies, Greater Inclusion? Exploring the Contradictions of New Labour Inclusive Education Policy

Science.gov (United States)

Roulstone, Alan; Prideaux, Simon

2008-01-01

The era of New Labour government has witnessed unprecedented growth in inclusive education policies. There is, however, limited evidence that policies have increased disabled children's inclusion. This article explores reasons for this contradiction. Drawing on sociological insights, it is argued that New Labour policies on inclusive education…
Inclusive LAMBDA production in sigma-proton collisions at 23 GeV/c

International Nuclear Information System (INIS)

Arik, E.

1976-01-01

Inclusive Λ 0 production resulting from Σ - -proton collisions was studied in the Brookhaven National Laboratory -AGS negative hyperon beam. The experiment consisted of scattering Σ - particles of momentum equal to 23 Gev/c on a liquid hydrogen target. The differential cross section was obtained as a function of missing mass squared and four-momentum transfer from the Σ - to the Λ 0 . The fit made to the predicted form of the differential cross section in the triple-Regge region indicates that this reaction is mediated by a virtual pion emission between the Σ - and p. The combination of Σ - Λ 0 π and Σ - Σ 0 π coupling constants was also determined
Designing heavy metal oxide glasses with threshold properties from network rigidity.

Science.gov (United States)

Chakraborty, Shibalik; Boolchand, P; Malki, M; Micoulaut, M

2014-01-07

Here, we show that a new class of glasses composed of heavy metal oxides involving transition metals (V2O5-TeO2) can surprisingly be designed from very basic tools using topology and rigidity of their underlying molecular networks. When investigated as a function of composition, such glasses display abrupt changes in network packing and enthalpy of relaxation at Tg, underscoring presence of flexible to rigid elastic phase transitions. We find that these elastic phases are fully consistent with polaronic nature of electronic conductivity at high V2O5 content. Such observations have new implications for designing electronic glasses which differ from the traditional amorphous electrolytes having only mobile ions as charge carriers.
Influence of the terrestrial magnetic field geometry on the cutoff rigidity of cosmic ray particles

International Nuclear Information System (INIS)

Herbst, K.; Kopp, A.; Heber, B.

2013-01-01

Studies of the propagation of charged energetic particles in the Earth's magnetic field go back to Carl Stoermer. In the end, his investigations finally lead to the definition of the so-called cutoff rigidity RC; that is, the minimum momentum per charge a particle must have in order to reach a certain geographical location. Employing Monte Carlo simulations with the PLANETOCOSMICS code we investigate the correlation between the geomagnetic field structure and the cutoff rigidity. We show that the geometry of the magnetic field has a considerable influence on the resulting cutoff rigidity distribution. Furthermore, we will present a simple geometry-based parameter, δB, which is able to reflect the location-dependent cutoff rigidity. We show that this correlation is also visible in the temporal evolution of the Earth's magnetic field, at least over the last 100 yr. Using latitude scans with neutron monitors, changes of the relative counting rates at different positions are calculated, showing small variations for, e.g., Kiel and Moscow, while large ones occur at Mexico City as well as on the British Virgin Islands.
Linguistic Diversity and Social Inclusion

Science.gov (United States)

Piller, Ingrid; Takahashi, Kimie

2011-01-01

This introduction provides the framework for the special issue by describing the social inclusion agenda of neoliberal market democracies. While the social inclusion agenda has been widely adopted, social inclusion policies are often blind to the ways in which language proficiency and language ideologies mediate social inclusion in linguistically…
Psychological prices of branded foods and price rigidity : evidence from German scanner data

OpenAIRE

Herrmann, Roland; Möser, Anke

2004-01-01

There is increasing evidence from scanner data that branded foods in the grocery retailing sector contain a substantial amount of price rigidity (HERRMANN/MÖSER 2003). One of the many alternative explanations for price rigidity is the existence of psychological pricing points. The economic literature has been most hesitant against this theory and, in a survey, BLINDER et al. (1998) found no confirmation at all based on the views of business managers. In that study, however, retail trade is un...
Inclusive pedagogy

DEFF Research Database (Denmark)

Korsgaard, Morten Timmermann; Mortensen, Stig Skov

of education. The article explores the relationship between Continental and Anglo-American educational theory, and why they seem to have developed in such distinct directions. Beginning with the Anglo-American perspective it is outlined how pedagogy and the so called educational interest became replaced...... and the politicisation of inclusive education, and a positive aim in the form of an argument for a move towards constructing a pedagogical ideal of inclusion....
Sums of squares of integers

CERN Document Server

Moreno, Carlos J

2005-01-01

Introduction Prerequisites Outline of Chapters 2 - 8 Elementary Methods Introduction Some Lemmas Two Fundamental Identities Euler's Recurrence for Sigma(n)More Identities Sums of Two Squares Sums of Four Squares Still More Identities Sums of Three Squares An Alternate Method Sums of Polygonal Numbers Exercises Bernoulli Numbers Overview Definition of the Bernoulli Numbers The Euler-MacLaurin Sum Formula The Riemann Zeta Function Signs of Bernoulli Numbers Alternate The von Staudt-Clausen Theorem Congruences of Voronoi and Kummer Irregular Primes Fractional Parts of Bernoulli Numbers Exercises Examples of Modular Forms Introduction An Example of Jacobi and Smith An Example of Ramanujan and Mordell An Example of Wilton: t (n) Modulo 23 An Example of Hamburger Exercises Hecke's Theory of Modular FormsIntroduction Modular Group ? and its Subgroup ? 0 (N) Fundamental Domains For ? and ? 0 (N) Integral Modular Forms Modular Forms of Type Mk(? 0(N);chi) and Euler-Poincare series Hecke Operators Dirichlet Series and ...
Inclusion in the East: Chinese Students' Attitudes towards Inclusive Education

Science.gov (United States)

Malinen, Olli-Pekka; Savolainen, Hannu

2008-01-01

A sample of 523 Chinese university students was given a questionnaire on their attitudes towards the inclusion of children with disabilities into regular classrooms. Factor analysis, analysis of variance, t-test and correlations were used to assess the respondents' general attitude towards inclusion, the factor structure of the attitudes, the…
Rigidity of Nominal Wages of Non-Production Workers in Industrial Sector

Directory of Open Access Journals (Sweden)

Bambang Sulistiyono

2016-06-01

Full Text Available Excess supply of labor leads to low the levels of nominal wages received by workers. The amount of minimum wage rate exceeds the market wage rate. The determination of minimum wage is a factor manifested in the institutional and regulatory Provincial Minimum Wage or a District Minimum Wage. Unfortunately, it has made nominal wages difficult to drop below the minimum wage level. High or low level of nominal wages are associated with worker productivity. Further, nominal wages are rigid to go down. If they have increased, they can not be dropped in the future even though the company's performance is declined. Knowing that condition, in designing the remuneration system, an employer should pay attention to the rigidity of nominal wages, so that when company's performance declines, the company will not be interfered because of the wages burden. Furthermore, unions and government should consider the rigidity impact of nominal wages that go down. Thus, when macroeconomic conditions deteriorate and company's performance drops, the company will not go bankrupt due to high labor costs. If the company goes bankrupt, the workers will loose their jobs as a result of employment termination, while the government will face the unemployment problem.
Dynamic Non-Rigid Objects Reconstruction with a Single RGB-D Sensor

Directory of Open Access Journals (Sweden)

Sen Wang

2018-03-01

Full Text Available This paper deals with the 3D reconstruction problem for dynamic non-rigid objects with a single RGB-D sensor. It is a challenging task as we consider the almost inevitable accumulation error issue in some previous sequential fusion methods and also the possible failure of surface tracking in a long sequence. Therefore, we propose a global non-rigid registration framework and tackle the drifting problem via an explicit loop closure. Our novel scheme starts with a fusion step to get multiple partial scans from the input sequence, followed by a pairwise non-rigid registration and loop detection step to obtain correspondences between neighboring partial pieces and those pieces that form a loop. Then, we perform a global registration procedure to align all those pieces together into a consistent canonical space as guided by those matches that we have established. Finally, our proposed model-update step helps fixing potential misalignments that still exist after the global registration. Both geometric and appearance constraints are enforced during our alignment; therefore, we are able to get the recovered model with accurate geometry as well as high fidelity color maps for the mesh. Experiments on both synthetic and various real datasets have demonstrated the capability of our approach to reconstruct complete and watertight deformable objects.
Modyfication of the Rigid Polyurethane-Polyisocyanurate Foams

OpenAIRE

Bogusław Czupryński; Joanna Liszkowska; Joanna Paciorek-Sadowska

2014-01-01

The effect of polyethylene glycol 1500 on physicomechanical properties of rigid polyurethane-polyisocyanurate (PUR-PIR) foams has been studied. It was found that application of polyethylene glycol 1500 for synthesis of foams in amount from 0% to 20% w/w had an effect on reduction of brittleness and softening point, while the greater the increase in compressive strength the higher its content in foam composition was. Wastes from production of these foams were ground and subjected to glycolysis...
Estimating the orientation of a rigid body moving in space using inertial sensors

Energy Technology Data Exchange (ETDEWEB)

He, Peng, E-mail: peng.he.1@ulaval.ca; Cardou, Philippe, E-mail: pcardou@gmc.ulaval.ca [Université Laval, Robotics Laboratory, Department of Mechanical Engineering (Canada); Desbiens, André, E-mail: andre.desbiens@gel.ulaval.ca [Université Laval, Department of Electrical and Computer Engineering (Canada); Gagnon, Eric, E-mail: Eric.Gagnon@drdc-rddc.gc.ca [RDDC Valcartier (Canada)

2015-09-15

This paper presents a novel method of estimating the orientation of a rigid body moving in space from inertial sensors, by discerning the gravitational and inertial components of the accelerations. In this method, both a rigid-body kinematics model and a stochastic model of the human-hand motion are formulated and combined in a nonlinear state-space system. The state equation represents the rigid body kinematics and stochastic model, and the output equation represents the inertial sensor measurements. It is necessary to mention that, since the output equation is a nonlinear function of the state, the extended Kalman filter (EKF) is applied. The absolute value of the error from the proposed method is shown to be less than 5 deg in simulation and in experiments. It is apparently stable, unlike the time-integration of gyroscope measurements, which is subjected to drift, and remains accurate under large accelerations, unlike the tilt-sensor method.
Estimating the orientation of a rigid body moving in space using inertial sensors

International Nuclear Information System (INIS)

He, Peng; Cardou, Philippe; Desbiens, André; Gagnon, Eric

2015-01-01

This paper presents a novel method of estimating the orientation of a rigid body moving in space from inertial sensors, by discerning the gravitational and inertial components of the accelerations. In this method, both a rigid-body kinematics model and a stochastic model of the human-hand motion are formulated and combined in a nonlinear state-space system. The state equation represents the rigid body kinematics and stochastic model, and the output equation represents the inertial sensor measurements. It is necessary to mention that, since the output equation is a nonlinear function of the state, the extended Kalman filter (EKF) is applied. The absolute value of the error from the proposed method is shown to be less than 5 deg in simulation and in experiments. It is apparently stable, unlike the time-integration of gyroscope measurements, which is subjected to drift, and remains accurate under large accelerations, unlike the tilt-sensor method
Homogenisation of sulphide inclusions within diamonds: A new approach to diamond inclusion geochemistry

Science.gov (United States)

McDonald, Iain; Hughes, Hannah S. R.; Butler, Ian B.; Harris, Jeffrey W.; Muir, Duncan

2017-11-01

Base metal sulphide (BMS) inclusions in diamonds provide a unique insight into the chalcophile and highly siderophile element composition of the mantle. Entombed within their diamond hosts, these provide a more robust (closed system) sample, from which to determine the trace element, Re-Os and S-isotopic compositions of the mantle than mantle xenoliths or orogenic peridotites, as they are shielded from alteration during ascent to the Earth's crust and subsequent surface weathering. However, at temperatures below 1100 °C some BMS inclusions undergo subsolidus re-equilibration from an original monosulphide solid solution (Mss) and this causes fractionation of the major and trace elements within the inclusions. Thus to study the subjects noted above, current techniques require the entire BMS inclusion to be extracted for analyses. Unfortunately, 'flaking' of inclusions during break-out is a frequent occurrence and hence the risk of accidentally under-sampling a portion of the BMS inclusion is inherent in current practices. This loss may have significant implications for Re-Os isotope analyses where incomplete sampling of a Re-rich phase, such as chalcopyrite that typically occurs at the outer margins of BMS inclusions, may induce significant bias in the Re-Os and 187Os/188Os measurements and resulting model and isochron ages. We have developed a method for the homogenisation of BMS inclusions in diamond prior to their break-out from the host stone. Diamonds are heated to 1100 °C and then quenched to chemically homogenise any sulphide inclusions for both major and trace elements. Using X-ray Computed Microtomography (μCT) we determine the shape and spatial setting of multiple inclusions within a host stone and crucially show that the volume of a BMS inclusion is the same both before and after homogenisation. We show that the homogenisation process significantly reduces the inherent variability of in situ analysis when compared with unhomogenised BMS, thereby
Study on the effect of testing machine rigidity on strength and ductility temperature dependences obtained

International Nuclear Information System (INIS)

Krashchenko, V.P.; Statsenko, V.E.; Rudnitskij, N.P.

1984-01-01

Investigation procedures are described for rigidity of testing machines and mechanical properties of tantalum and nickel in the temperature range 293-1873K. Temperature dependences are presented for strength characteristics of the investigated materials obtained with the use of installations of different rigidity. Dependence analysis is carried out and recommendations are given as to the characteristics application

Limitations of inclusive fitness.

Science.gov (United States)

Allen, Benjamin; Nowak, Martin A; Wilson, Edward O

2013-12-10

Until recently, inclusive fitness has been widely accepted as a general method to explain the evolution of social behavior. Affirming and expanding earlier criticism, we demonstrate that inclusive fitness is instead a limited concept, which exists only for a small subset of evolutionary processes. Inclusive fitness assumes that personal fitness is the sum of additive components caused by individual actions. This assumption does not hold for the majority of evolutionary processes or scenarios. To sidestep this limitation, inclusive fitness theorists have proposed a method using linear regression. On the basis of this method, it is claimed that inclusive fitness theory (i) predicts the direction of allele frequency changes, (ii) reveals the reasons for these changes, (iii) is as general as natural selection, and (iv) provides a universal design principle for evolution. In this paper we evaluate these claims, and show that all of them are unfounded. If the objective is to analyze whether mutations that modify social behavior are favored or opposed by natural selection, then no aspect of inclusive fitness theory is needed.
Vertical dimensional stability and rigidity of occlusal registration materials.

Science.gov (United States)

Walker, Mary P; Wu, Edis; Heckman, M Elizabeth; Alderman, Nicholas

2009-01-01

Dimensionally accurate occlusal registration records are essential for restorative dentistry; moreover, since records are not used immediately or may be used more than once, the registration material should exhibit accuracy over time (a concept known as dimensional stability). It has been speculated that materials with increased hardness or rigidity should produce more accurate registration records due to an increased resistance to distortion. This study compared the rigidity and associated dimensional accuracy of a recently marketed bisacrylic occlusal registration material and a vinyl polysiloxane (VPS). Maxillary and mandibular typodont arches were mounted on a plasterless articulator from which teeth No. 3, 13, and 15 had been removed to simulate edentulous spaces. After preparing teeth No. 2, 4, 12, and 14 as bridge abutments, the remaining teeth were equilibrated selectively to produce even anterior contact. Four digital photographs were taken to make vertical interarch measurements at four locations (teeth No. 3, 7, 10, and 14). Following initial photos (controls), 10 interocclusal records were made using each registration material, with material placed only in the segments in which teeth were prepared. The records were used for mounting the maxillary arch against the mandibular arch after 48, 72, and 120 hours. There were significant effects on vertical dimensional change related to arch location, material, and mounting time. Both materials demonstrated significantly larger posterior vertical openings than anterior vertical openings, while the bisacrylate produced a larger posterior opening than VPS at 48 and 72 hours and a larger anterior opening at all mounting times. There also was a significant difference in hardness/rigidity due to material and measurement time; at all measurement times, bisacrylate exhibited a significantly higher hardness number.
Does Semi-Rigid Instrumentation Using Both Flexion and Extension Dampening Spacers Truly Provide an Intermediate Level of Stabilization?

Directory of Open Access Journals (Sweden)

Dilip Sengupta

2013-01-01

Full Text Available Conventional posterior dynamic stabilization devices demonstrated a tendency towards highly rigid stabilization approximating that of titanium rods in flexion. In extension, they excessively offload the index segment, making the device as the sole load-bearing structure, with concerns of device failure. The goal of this study was to compare the kinematics and intradiscal pressure of monosegmental stabilization utilizing a new device that incorporates both a flexion and extension dampening spacer to that of rigid internal fixation and a conventional posterior dynamic stabilization device. The hypothesis was the new device would minimize the overloading of adjacent levels compared to rigid and conventional devices which can only bend but not stretch. The biomechanics were compared following injury in a human cadaveric lumbosacral spine under simulated physiological loading conditions. The stabilization with the new posterior dynamic stabilization device significantly reduced motion uniformly in all loading directions, but less so than rigid fixation. The evaluation of adjacent level motion and pressure showed some benefit of the new device when compared to rigid fixation. Posterior dynamic stabilization designs which both bend and stretch showed improved kinematic and load-sharing properties when compared to rigid fixation and when indirectly compared to existing conventional devices without a bumper.
Real-time motion compensated patient positioning and non-rigid deformation estimation using 4-D shape priors.

Science.gov (United States)

Wasza, Jakob; Bauer, Sebastian; Hornegger, Joachim

2012-01-01

Over the last years, range imaging (RI) techniques have been proposed for patient positioning and respiration analysis in motion compensation. Yet, current RI based approaches for patient positioning employ rigid-body transformations, thus neglecting free-form deformations induced by respiratory motion. Furthermore, RI based respiration analysis relies on non-rigid registration techniques with run-times of several seconds. In this paper we propose a real-time framework based on RI to perform respiratory motion compensated positioning and non-rigid surface deformation estimation in a joint manner. The core of our method are pre-procedurally obtained 4-D shape priors that drive the intra-procedural alignment of the patient to the reference state, simultaneously yielding a rigid-body table transformation and a free-form deformation accounting for respiratory motion. We show that our method outperforms conventional alignment strategies by a factor of 3.0 and 2.3 in the rotation and translation accuracy, respectively. Using a GPU based implementation, we achieve run-times of 40 ms.
Collisions of Constrained Rigid Body Systems with Friction

Directory of Open Access Journals (Sweden)

Haijun Shen

1998-01-01

Full Text Available A new approach is developed for the general collision problem of two rigid body systems with constraints (e.g., articulated systems, such as massy linkages in which the relative tangential velocity at the point of contact and the associated friction force can change direction during the collision. This is beyond the framework of conventional methods, which can give significant and very obvious errors for this problem, and both extends and consolidates recent work. A new parameterization and theory characterize if, when and how the relative tangential velocity changes direction during contact. Elastic and dissipative phenomena and different values for static and kinetic friction coefficients are included. The method is based on the explicitly physical analysis of events at the point of contact. Using this method, Example 1 resolves (and corrects a paradox (in the literature of the collision of a double pendulum with the ground. The method fundamentally subsumes other recent models and the collision of rigid bodies; it yields the same results as conventional methods when they would apply (Example 2. The new method reformulates and extends recent approaches in a completely physical context.
Mechanical Characterization of Rigid Polyurethane Foams

Energy Technology Data Exchange (ETDEWEB)

Lu, Wei-Yang [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Mechanics of Materials

2014-12-01

Foam materials are used to protect sensitive components from impact loading. In order to predict and simulate the foam performance under various loading conditions, a validated foam model is needed and the mechanical properties of foams need to be characterized. Uniaxial compression and tension tests were conducted for different densities of foams under various temperatures and loading rates. Crush stress, tensile strength, and elastic modulus were obtained. A newly developed confined compression experiment provided data for investigating the foam flow direction. A biaxial tension experiment was also developed to explore the damage surface of a rigid polyurethane foam.
Partial ring currents and cosmic ray magnetic cutoff rigidity variations

International Nuclear Information System (INIS)

Arens, M.

1978-01-01

A short introduction on cosmic ray modulation and a description of the magnetosphere, and of some physical processes occurring within its boundaries are presented. 20 geomagnetic storms are analysed together with the cosmic ray intensities during these storms as measured by Neutron Monitors. Using a semi-empirical method, the variations in the magnetic cutoff rigidity for the mountain stations Pic du Midi and Jungfraujoch are deduced. These stations are the most sensitive for measuring these variations. The analysis shows that all analyzed storms have an asymmetric development phase. Often the asymmetry even continues during part of the recovery phase. It is shown that variations in magnetic cutoff rigidity occur only during the asymmetric phase of the storm. The largest variations are found when the cosmic ray station is located in the late afternoon-midnight sector. (Auth.)
Vapor-liquid equilibrium and critical asymmetry of square well and short square well chain fluids.

Science.gov (United States)

Li, Liyan; Sun, Fangfang; Chen, Zhitong; Wang, Long; Cai, Jun

2014-08-07

The critical behavior of square well fluids with variable interaction ranges and of short square well chain fluids have been investigated by grand canonical ensemble Monte Carlo simulations. The critical temperatures and densities were estimated by a finite-size scaling analysis with the help of histogram reweighting technique. The vapor-liquid coexistence curve in the near-critical region was determined using hyper-parallel tempering Monte Carlo simulations. The simulation results for coexistence diameters show that the contribution of |t|(1-α) to the coexistence diameter dominates the singular behavior in all systems investigated. The contribution of |t|(2β) to the coexistence diameter is larger for the system with a smaller interaction range λ. While for short square well chain fluids, longer the chain length, larger the contribution of |t|(2β). The molecular configuration greatly influences the critical asymmetry: a short soft chain fluid shows weaker critical asymmetry than a stiff chain fluid with same chain length.
Inclusive innovation: a research project on the inclusion of social responsibility

NARCIS (Netherlands)

Nijhof, A.H.J.; Fisscher, O.A.M.; de Bakker, F.G.A.

2001-01-01

The research project 'Inclusive Innovation' aims at stimulating dialogue about inclusion of social responsibility based on universal human rights in the conduct of business. This dialogue concerns both the communication within the organisation and between the organisation and interested parties in
Phase transition in a modified square Josephson-junction array

CERN Document Server

Han, J

1999-01-01

We study the phase transition in a modified square proximity-coupled Josephson-junction array with small superconducting islands at the center of each plaquette. We find that the modified square array undergoes a Kosterlitz-Thouless-Berezinskii-like phase transition, but at a lower temperature than the simple square array with the same single-junction critical current. The IV characteristics, as well as the phase transition, resemble qualitatively those of a disordered simple square array. The effects of the presence of the center islands in the modified square array are discussed.
INVESTIGATION OF REPRESENTATIVE CHARACTERISTICS OF LUKIŠKIŲ SQUARE IN VILNIUS

Directory of Open Access Journals (Sweden)

Gintautas TIŠKUS

2018-05-01

Full Text Available Representative squares are sites where ideological monuments or monuments are built, or squares to important state or municipal buildings. Representation square is a mark or sign system that is intended to provide some relevant information. This information may include events or actors that are important and desirable to commemorate, ideological - political motives that want to be given exclusive importance. In determining the structure of the area’s representative area, causal relationships with the represented object are identified. The original key information is the name. Subsequently, the type of object represented – an event or personality, a connection to the square, the importance of the mark on the square (dominant, noticeable or invisible, and the interaction between the label and the environment are determined. After examining the structure of the square of the square and writing the values in the matrix, we can determine the representation level of the square. In the representation square we can name the square, for which the context of the environment and the level of representational marks for the purpose of the square have a decisive or significant influence.
A Weighted Least Squares Approach To Robustify Least Squares Estimates.

Science.gov (United States)

Lin, Chowhong; Davenport, Ernest C., Jr.

This study developed a robust linear regression technique based on the idea of weighted least squares. In this technique, a subsample of the full data of interest is drawn, based on a measure of distance, and an initial set of regression coefficients is calculated. The rest of the data points are then taken into the subsample, one after another,…
Composite Sliding Mode Control for a Free-Floating Space Rigid-Flexible Coupling Manipulator System

OpenAIRE

Congqing, Wang; Pengfei, Wu; Xin, Zhou; Xiwu, Pei

2013-01-01

The flexible space manipulator is a highly nonlinear and coupled dynamic system. This paper proposes a novel composite sliding mode control to deal with the vibration suppression and trajectory tracking of a free-floating space rigid-flexible coupling manipulator with a rigid payload. First, the dynamic equations of this system are established by using Lagrange and assumed mode methods and in the meantime this dynamic modelling allows consideration of the modelling errors, the external distur...
Financial inclusion: Policies and practices

Directory of Open Access Journals (Sweden)

Thankom Arun

2015-12-01

Full Text Available As a key enabler for development, financial inclusion is firmly placed on the agenda of most governments as a key policy priority. Against this background, this round table provides a global and regional perspective on the policies and practices of financial inclusion. Using macro data, the collection reveals the diversity in the efforts towards achieving financial inclusion and the need for a progressive approach in financial inclusion. Further to this, the round table provides the regional perspectives on the policies and practices of financial inclusion in India, South Africa, and Australia.
Rapid maxillary distraction protocol utilizing the halo distraction system and rigid internal fixation.

Science.gov (United States)

Baker, Stephen B; Reid, Russell R; Burkey, Brooke; Bartlett, Scott P

2007-09-01

To shorten head frame wear time associated with external halo distraction (HD), we have adapted a protocol for maxillary distraction with the halo system that integrates plate fixation. All patients had a history of cleft lip and/or palate and maxillary retrusion > or = 8 mm. Five patients treated with this protocol and followed for at least 1 year were included in this study. The protocol included a 3-day latency period, variable maxillary distraction, and removal of the halo device with simultaneous rigid internal fixation. Two patients had a variable period of maxillomandibular fixation (MMF), which maintained the maxillary advancement and idealized intercuspal position while permitting further callus maturation. Cephalographs were obtained preoperatively, immediately following distractor removal, and 1 year after rigid internal fixation. The mean age at time of surgery was 18.7 years. The maxillary deficiency ranged from 8 to 15 mm (mean = 10.6 mm). All five patients demonstrated excellent occlusion. Cephalometric analysis 1-year post rigid internal fixation revealed minimal (maxillary distraction followed by MMF to maintain maxillary advancement may reduce halo device wear to 1 to 2 weeks. MMF optimizes occlusion by forcing the maxillary teeth into maximal intercuspal position. Rigid fixation is not only associated with less long-term relapse compared to nonrigid forms of fixation, but also minimizes the incidence of nonunion. This treatment protocol provides the advancement possible with distraction osteogenesis and the accuracy of orthognathic surgery, thereby minimizing external head frame wear.
Laparoscopic - assisted transpyelic rigid nephroscopy - simple alternative when flexible ureteroscopy is not available

Directory of Open Access Journals (Sweden)

Marcos Tobias-Machado

Full Text Available ABSTRACT Introduction: In special situations such as malrotated or ectopic kidneys and UPJ stenosis treatment of renal lithiasis can be challenging. In these rare cases laparoscopy can be indicated. Objective: Describe the Laparoscopic-assisted rigid nephroscopy performed via transpyelic approach and report the feasibility. Patients and methods: We present two cases of caliceal lithiasis. The first is a patient that ESWL and previous percutaneous lithotripsy have failed, with pelvic kidney where laparoscopic dissection of renal pelvis was carried out followed by nephroscopy utilizing the 30 Fr rigid nephroscope to remove the calculus. Ideal angle between the major axis of renal pelvis and the rigid nephroscope to allow success with this technique was 60-90 grades. In the second case, the kidney had a dilated infundibulum. Results: The operative time was 180 minutes for both procedures. No significant blood loss or perioperative complications occurred. The bladder catheter was removed in the postoperative day 1 and Penrose drain on day 2 when patients were discharged. The convalescence was completed after 3 weeks. Patients were stone free without symptons in one year of follow-up. Conclusions: Laparoscopic-assisted rigid nephroscopy performed via tranpyelic approach can be done safely with proper patient selection and adherence to standard laparoscopic surgical principles. This approach is an alternative in cases where flexible endoscope is not available and when standard procedure is unlikely to produce a stone-free status.
A survey on stability and rigidity results for Lie algebras

NARCIS (Netherlands)

Crainic, Marius; Schätz, Florian; Struchiner, Ivan

2014-01-01

We give simple and unified proofs of the known stability and rigidity results for Lie algebras, Lie subalgebras and Lie algebra homomorphisms. Moreover, we investigate when a Lie algebra homomorphism is stable under all automorphisms of the codomain (including outer automorphisms).
INCLUSIVE CULTURE IN PRE-SCHOOL INSTITUTIONS

Directory of Open Access Journals (Sweden)

Irena NOVACHEVSKA

2011-04-01

Full Text Available Inclusive education is a rational concept that refers to the overall and long-term transformation of institutional systems in society, especially in education. Along with the transformation, a number of important and unresolved issues still appear in both theory and practice, as the duty of pre-school institutions and schools is to educate every student in the mainstream education system. One of the most important aspects of inclusion is the inclusive culture. Regardless of the good inclusive policy and practice, one cannot talk about successful inclusion without a properly developed inclusive institutional culture.This paper is a contribution to the research considering the development of inclusive culture in three preschool institutions. It is based on the thinking and attitudes of the preschool staff toward the necessity of developing and nurturing an inclusive culture. Successful inclusion of pupils with special needs in the mainstream school system cannot be conceived without an inclusive culture.
Topological classification of the Goryachev integrable case in rigid body dynamics

International Nuclear Information System (INIS)

Nikolaenko, S S

2016-01-01

A topological analysis of the Goryachev integrable case in rigid body dynamics is made on the basis of the Fomenko-Zieschang theory. The invariants (marked molecules) which are obtained give a complete description, from the standpoint of Liouville classification, of the systems of Goryachev type on various level sets of the energy. It turns out that on appropriate energy levels the Goryachev case is Liouville equivalent to many classical integrable systems and, in particular, the Joukowski, Clebsch, Sokolov and Kovalevskaya-Yehia cases in rigid body dynamics, as well as to some integrable billiards in plane domains bounded by confocal quadrics -- in other words, the foliations given by the closures of generic solutions of these systems have the same structure. Bibliography: 15 titles
21 CFR 886.5916 - Rigid gas permeable contact lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rigid gas permeable contact lens. 886.5916 Section 886.5916 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... against the cornea of the eye to correct vision conditions. The device is made of various materials, such...

Around and Beyond the Square of Opposition

CERN Document Server

Béziau, Jean-Yves

2012-01-01

aiThe theory of oppositions based on Aristotelian foundations of logic has been pictured in a striking square diagram which can be understood and applied in many different ways having repercussions in various fields: epistemology, linguistics, mathematics, psychology. The square can also be generalized in other two-dimensional or multi-dimensional objects extending in breadth and depth the original theory of oppositions of Aristotle. The square of opposition is a very attractive theme which has been going through centuries without evaporating. Since 10 years there is a new growing interest for
Comparison of numerical results between related shapes using a non-rigid mapping with statistical quantication of uncertainty

CSIR Research Space (South Africa)

Jansen van Rensburg, Gerhardus J

2011-10-01

Full Text Available In the present study, numerical results obtained on different but related shapes are compared by using a non-rigid mapping. Non-rigid registration is employed to obtain mesh representations of different human skull geometries with the same mesh...
Deformation analysis with Total Least Squares

Directory of Open Access Journals (Sweden)

M. Acar

2006-01-01

Full Text Available Deformation analysis is one of the main research fields in geodesy. Deformation analysis process comprises measurement and analysis phases. Measurements can be collected using several techniques. The output of the evaluation of the measurements is mainly point positions. In the deformation analysis phase, the coordinate changes in the point positions are investigated. Several models or approaches can be employed for the analysis. One approach is based on a Helmert or similarity coordinate transformation where the displacements and the respective covariance matrix are transformed into a unique datum. Traditionally a Least Squares (LS technique is used for the transformation procedure. Another approach that could be introduced as an alternative methodology is the Total Least Squares (TLS that is considerably a new approach in geodetic applications. In this study, in order to determine point displacements, 3-D coordinate transformations based on the Helmert transformation model were carried out individually by the Least Squares (LS and the Total Least Squares (TLS, respectively. The data used in this study was collected by GPS technique in a landslide area located nearby Istanbul. The results obtained from these two approaches have been compared.
Prediction of flexible/rigid regions from protein sequences using k-spaced amino acid pairs

Directory of Open Access Journals (Sweden)

Ruan Jishou

2007-04-01

Full Text Available Abstract Background Traditionally, it is believed that the native structure of a protein corresponds to a global minimum of its free energy. However, with the growing number of known tertiary (3D protein structures, researchers have discovered that some proteins can alter their structures in response to a change in their surroundings or with the help of other proteins or ligands. Such structural shifts play a crucial role with respect to the protein function. To this end, we propose a machine learning method for the prediction of the flexible/rigid regions of proteins (referred to as FlexRP; the method is based on a novel sequence representation and feature selection. Knowledge of the flexible/rigid regions may provide insights into the protein folding process and the 3D structure prediction. Results The flexible/rigid regions were defined based on a dataset, which includes protein sequences that have multiple experimental structures, and which was previously used to study the structural conservation of proteins. Sequences drawn from this dataset were represented based on feature sets that were proposed in prior research, such as PSI-BLAST profiles, composition vector and binary sequence encoding, and a newly proposed representation based on frequencies of k-spaced amino acid pairs. These representations were processed by feature selection to reduce the dimensionality. Several machine learning methods for the prediction of flexible/rigid regions and two recently proposed methods for the prediction of conformational changes and unstructured regions were compared with the proposed method. The FlexRP method, which applies Logistic Regression and collocation-based representation with 95 features, obtained 79.5% accuracy. The two runner-up methods, which apply the same sequence representation and Support Vector Machines (SVM and Naïve Bayes classifiers, obtained 79.2% and 78.4% accuracy, respectively. The remaining considered methods are
Evolution of motions of a rigid body about its center of mass

CERN Document Server

Chernousko, Felix L; Leshchenko, Dmytro D

2017-01-01

The book presents a unified and well-developed approach to the dynamics of angular motions of rigid bodies subjected to perturbation torques of different physical nature. It contains both the basic foundations of the rigid body dynamics and of the asymptotic method of averaging. The rigorous approach based on the averaging procedure is applicable to bodies with arbitrary ellopsoids of inertia. Action of various perturbation torques, both external (gravitational, aerodynamical, solar pressure) and internal (due to viscous fluid in tanks, elastic and visco-elastic properties of a body) is considered in detail. The book can be used by researchers, engineers and students working in attitude dynamics of spacecraft.
Nonlinear static analysis of steel frames with semi rigid beam to column connections using cruciform element

Directory of Open Access Journals (Sweden)

Vahid Reza Afkhami

2017-12-01

Full Text Available In the steel frames, beam-column connections are traditionally assumed to be rigid or pinned, but in the steel frames, most types of beam-column connections are semi-rigid. Recent studies and some new codes, especially EC3 and EC4, include methods and formulas to estimate the resistance and stiffness of the panel zone. Because of weaknesses of EC3 and EC4 in some cases, Bayo et al. proposed a new component-based method (cruciform element method to model internal and external semi-rigid connections that revived and modified EC methods. The nonlinear modelling of structures plays an important role in the analysis and design of structures and nonlinear static analysis is a rather simple and efficient technique for analysis of structures. This paper presents nonlinear static (pushover analysis technique by new nonlinearity factor and Bayo et al. model of two types of semi-rigid connections, end plate connection and top and seat angles connection. Two types of lateral loading, uniform and triangular distributions are considered. Results show that the frames with top and seat angles connection have fewer initial stiffness than frames with semi-rigid connection and P-Δ effect more decreases base shear capacity in the case of top and seat angles connection. P-Δ effect in decrease of base shear capacity increases with the increase of number of stories.
Least-squares reverse time migration of multiples

KAUST Repository

Zhang, Dongliang; Schuster, Gerard T.

2013-01-01

The theory of least-squares reverse time migration of multiples (RTMM) is presented. In this method, least squares migration (LSM) is used to image free-surface multiples where the recorded traces are used as the time histories of the virtual
Mechanical design for the Evryscope: a minute cadence, 10,000-square-degree FoV, gigapixel-scale telescope

Science.gov (United States)

Ratzloff, Jeff; Law, Nicholas M.; Fors, Octavi; Wulfken, Philip J.

2015-01-01

We designed, tested, prototyped and built a compact 27-camera robotic telescope that images 10,000 square degrees in 2-minute exposures. We exploit mass produced interline CCD Cameras with Rokinon consumer lenses to economically build a telescope that covers this large part of the sky simultaneously with a good enough pixel sampling to avoid the confusion limit over most of the sky. We developed the initial concept into a 3-d mechanical design with the aid of computer modeling programs. Significant design components include the camera assembly-mounting modules, the hemispherical support structure, and the instrument base structure. We simulated flexure and material stress in each of the three main components, which helped us optimize the rigidity and materials selection, while reducing weight. The camera mounts are CNC aluminum and the support shell is reinforced fiberglass. Other significant project components include optimizing camera locations, camera alignment, thermal analysis, environmental sealing, wind protection, and ease of access to internal components. The Evryscope will be assembled at UNC Chapel Hill and deployed to the CTIO in 2015.
How soft is that pillow? The perceptual localization of the hand and the haptic assessment of contact rigidity.

Science.gov (United States)

Pressman, Assaf; Karniel, Amir; Mussa-Ivaldi, Ferdinando A

2011-04-27

A new haptic illusion is described, in which the location of the mobile object affects the perception of its rigidity. There is theoretical and experimental support for the notion that limb position sense results from the brain combining ongoing sensory information with expectations arising from prior experience. How does this probabilistic state information affect one's tactile perception of the environment mechanics? In a simple estimation process, human subjects were asked to report the relative rigidity of two simulated virtual objects. One of the objects remained fixed in space and had various coefficients of stiffness. The other virtual object had constant stiffness but moved with respect to the subjects. Earlier work suggested that the perception of an object's rigidity is consistent with a process of regression between the contact force and the perceived amount of penetration inside the object's boundary. The amount of penetration perceived by the subject was affected by varying the position of the object. This, in turn, had a predictable effect on the perceived rigidity of the contact. Subjects' reports on the relative rigidity of the object are best accounted for by a probabilistic model in which the perceived boundary of the object is estimated based on its current location and on past observations. Therefore, the perception of contact rigidity is accounted for by a stochastic process of state estimation underlying proprioceptive localization of the hand.
Fluid inclusion geothermometry

Science.gov (United States)

Cunningham, C.G.

1977-01-01

Fluid inclusions trapped within crystals either during growth or at a later time provide many clues to the histories of rocks and ores. Estimates of fluid-inclusion homogenization temperature and density can be obtained using a petrographic microscope with thin sections, and they can be refined using heating and freezing stages. Fluid inclusion studies, used in conjunction with paragenetic studies, can provide direct data on the time and space variations of parameters such as temperature, pressure, density, and composition of fluids in geologic environments. Changes in these parameters directly affect the fugacity, composition, and pH of fluids, thus directly influencing localization of ore metals. ?? 1977 Ferdinand Enke Verlag Stuttgart.
Becoming Inclusive: A Code of Conduct for Inclusion and Diversity.

Science.gov (United States)

Schmidt, Bonnie J; MacWilliams, Brent R; Neal-Boylan, Leslie

There are increasing concerns about exclusionary behaviors and lack of diversity in the nursing profession. Exclusionary behaviors, which may include incivility, bullying, and workplace violence, discriminate and isolate individuals and groups who are different, whereas inclusive behaviors encourage diversity. To address inclusion and diversity in nursing, this article offers a code of conduct. This code of conduct builds on existing nursing codes of ethics and applies to nursing students and nurses in both educational and practice settings. Inclusive behaviors that are demonstrated in nurses' relationships with patients, colleagues, the profession, and society are described. This code of conduct provides a basis for measureable change, empowerment, and unification of the profession. Recommendations, implications, and a pledge to action are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.
Quantum charged rigid membrane

Energy Technology Data Exchange (ETDEWEB)

Cordero, Ruben [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del I.P.N., Unidad Adolfo Lopez Mateos, Edificio 9, 07738 Mexico, D.F. (Mexico); Molgado, Alberto [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, Zacatecas Zac. (Mexico); Rojas, Efrain, E-mail: cordero@esfm.ipn.mx, E-mail: amolgado@fisica.uaz.edu.mx, E-mail: efrojas@uv.mx [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico)

2011-03-21

The early Dirac proposal to model the electron as a charged membrane is reviewed. A rigidity term, instead of the natural membrane tension, involving linearly the extrinsic curvature of the worldvolume swept out by the membrane is considered in the action modeling the bubble in the presence of an electromagnetic field. We set up this model as a genuine second-order derivative theory by considering a non-trivial boundary term which plays a relevant part in our formulation. The Lagrangian in question is linear in the bubble acceleration and by means of the Ostrogradski-Hamiltonian approach, we observed that the theory comprises the management of both first- and second-class constraints. We thus show that our second-order approach is robust allowing for a proper quantization. We found an effective quantum potential which permits us to compute bounded states for the system. We comment on the possibility of describing brane world universes by invoking this kind of second-order correction terms.
Quantum charged rigid membrane

International Nuclear Information System (INIS)

Cordero, Ruben; Molgado, Alberto; Rojas, Efrain

2011-01-01

The early Dirac proposal to model the electron as a charged membrane is reviewed. A rigidity term, instead of the natural membrane tension, involving linearly the extrinsic curvature of the worldvolume swept out by the membrane is considered in the action modeling the bubble in the presence of an electromagnetic field. We set up this model as a genuine second-order derivative theory by considering a non-trivial boundary term which plays a relevant part in our formulation. The Lagrangian in question is linear in the bubble acceleration and by means of the Ostrogradski-Hamiltonian approach, we observed that the theory comprises the management of both first- and second-class constraints. We thus show that our second-order approach is robust allowing for a proper quantization. We found an effective quantum potential which permits us to compute bounded states for the system. We comment on the possibility of describing brane world universes by invoking this kind of second-order correction terms.
Matrix rigidity induces osteolytic gene expression of metastatic breast cancer cells.

Directory of Open Access Journals (Sweden)

Nazanin S Ruppender

Full Text Available Nearly 70% of breast cancer patients with advanced disease will develop bone metastases. Once established in bone, tumor cells produce factors that cause changes in normal bone remodeling, such as parathyroid hormone-related protein (PTHrP. While enhanced expression of PTHrP is known to stimulate osteoclasts to resorb bone, the environmental factors driving tumor cells to express PTHrP in the early stages of development of metastatic bone disease are unknown. In this study, we have shown that tumor cells known to metastasize to bone respond to 2D substrates with rigidities comparable to that of the bone microenvironment by increasing expression and production of PTHrP. The cellular response is regulated by Rho-dependent actomyosin contractility mediated by TGF-ß signaling. Inhibition of Rho-associated kinase (ROCK using both pharmacological and genetic approaches decreased PTHrP expression. Furthermore, cells expressing a dominant negative form of the TGF-ß receptor did not respond to substrate rigidity, and inhibition of ROCK decreased PTHrP expression induced by exogenous TGF-ß. These observations suggest a role for the differential rigidity of the mineralized bone microenvironment in early stages of tumor-induced osteolysis, which is especially important in metastatic cancer since many cancers (such as those of the breast and lung preferentially metastasize to bone.
A new stabilized least-squares imaging condition

International Nuclear Information System (INIS)

Vivas, Flor A; Pestana, Reynam C; Ursin, Bjørn

2009-01-01

The classical deconvolution imaging condition consists of dividing the upgoing wave field by the downgoing wave field and summing over all frequencies and sources. The least-squares imaging condition consists of summing the cross-correlation of the upgoing and downgoing wave fields over all frequencies and sources, and dividing the result by the total energy of the downgoing wave field. This procedure is more stable than using the classical imaging condition, but it still requires stabilization in zones where the energy of the downgoing wave field is small. To stabilize the least-squares imaging condition, the energy of the downgoing wave field is replaced by its average value computed in a horizontal plane in poorly illuminated regions. Applications to the Marmousi and Sigsbee2A data sets show that the stabilized least-squares imaging condition produces better images than the least-squares and cross-correlation imaging conditions
SUPPORT IN INCLUSIVE EDUCATION

OpenAIRE

Belma Čičkušić; Ševala Tulumović; Selma Bakić; Salem Bakić

2016-01-01

In order for inclusive class to be successful, associates are of great help to teachers. Besides associates, teachers' specialization can be accomplished through educational seminars on the inclusion topic. However, information about inclusion, working with children with special needs, can also be found in scientific journals that offer more information on methods of working with children with special needs, didactic materials customized according to abilities of children. Aim of ...
Heat Transfer Modeling for Rigid High-Temperature Fibrous Insulation

Science.gov (United States)

Daryabeigi, Kamran; Cunnington, George R.; Knutson, Jeffrey R.

2012-01-01

Combined radiation and conduction heat transfer through a high-temperature, high-porosity, rigid multiple-fiber fibrous insulation was modeled using a thermal model previously used to model heat transfer in flexible single-fiber fibrous insulation. The rigid insulation studied was alumina enhanced thermal barrier (AETB) at densities between 130 and 260 kilograms per cubic meter. The model consists of using the diffusion approximation for radiation heat transfer, a semi-empirical solid conduction model, and a standard gas conduction model. The relevant parameters needed for the heat transfer model were estimated from steady-state thermal measurements in nitrogen gas at various temperatures and environmental pressures. The heat transfer modeling methodology was evaluated by comparison with standard thermal conductivity measurements, and steady-state thermal measurements in helium and carbon dioxide gases. The heat transfer model is applicable over the temperature range of 300 to 1360 K, pressure range of 0.133 to 101.3 x 10(exp 3) Pa, and over the insulation density range of 130 to 260 kilograms per cubic meter in various gaseous environments.
Non-rigid registration of tomographic images with Fourier transforms

International Nuclear Information System (INIS)

Osorio, Ar; Isoardi, Ra; Mato, G

2007-01-01

Spatial image registration of deformable body parts such as thorax and abdomen has important medical applications, but at the same time, it represents an important computational challenge. In this work we propose an automatic algorithm to perform non-rigid registration of tomographic images using a non-rigid model based on Fourier transforms. As a measure of similarity, we use the correlation coefficient, finding that the optimal order of the transformation is n = 3 (36 parameters). We apply this method to a digital phantom and to 7 pairs of patient images corresponding to clinical CT scans. The preliminary results indicate a fairly good agreement according to medical experts, with an average registration error of 2 mm for the case of clinical images. For 2D images (dimensions 512x512), the average running time for the algorithm is 15 seconds using a standard personal computer. Summarizing, we find that intra-modality registration of the abdomen can be achieved with acceptable accuracy for slight deformations and can be extended to 3D with a reasonable execution time
Quantum theory of gauge fields and rigid processes calculation

International Nuclear Information System (INIS)

Andreev, I.V.

1981-01-01

Elementary statement of the basic data on the nature of quark interactions and their role in the high energy processes is presented in the first part of the paper. The second part of the paper deals with gauge theory (GT) of strong interactions (chromodynamics (CD)) and its application in calculation of rigid processes with quark participation. It is based on the method of functional integration (MFI). A comparatively simple representation of the MFI in the quantum theory and formulation of the perturbation theory for gauge fields are given. A derivation of the rules of diagram technique is presented. Renormalization invariance of the theory and the basic for CD phenomenon of asymptotical freedom are discussed. Theory application in calculation of certain effects at high energies is considered. From the CD view point considered is a parton model on the base of which ''rigid'' stage of evolution of quark and gluon jets produced at high energies can be quantitatively described and some quantitative experimental tests of the CD are suggested [ru
Measurement of Spindle Rigidity by using a Magnet Loader

Science.gov (United States)

Yamazaki, Taku; Matsubara, Atsushi; Fujita, Tomoya; Muraki, Toshiyuki; Asano, Kohei; Kawashima, Kazuyuki

The static rigidity of a rotating spindle in the radial direction is investigated in this research. A magnetic loading device (magnet loader) has been developed for the measurement. The magnet loader, which has coils and iron cores, generates the electromagnetic force and attracts a dummy tool attached to the spindle. However, the eddy current is generated in the dummy tool with the spindle rotation and reduces the attractive force at high spindle speed. In order to understand the magnetic flux and eddy current in the dummy tool, the electromagnetic field analysis by FEM was carried out. Grooves on the attraction surface of the dummy tool were designed to cut the eddy current flow. The dimension of the groove were decided based on the FEM analysis, and the designed tool were manufactured and tested. The test result shows that the designed tool successfully reduces the eddy current and recovers the attractive force. By using the magnet loader and the grooved tool, the spindle rigidity can be measured when the spindle rotates with a speed up to 10,000 min-1.

Iterative CT reconstruction with correction for known rigid motion

Energy Technology Data Exchange (ETDEWEB)

Nuyts, Johan [Katholieke Univ. Leuven (Belgium). Dept. of Nuclear Medicine; Kim, Jung-Ha; Fulton, Roger [Sydney Univ., NSW (Australia). School of Physics; Westmead Hospital, Sydney (Australia). Medical Physics

2011-07-01

In PET/CT brain imaging, correction for motion may be needed, in particular for children and psychiatric patients. Motion is more likely to occur in the lengthy PET measurement, but also during the short CT acquisition patient motion is possible. Rigid motion of the head can be measured independently from the PET/CT system with optical devices. In this paper, we propose a method and some preliminary simulation results for iterative CT reconstruction with correction for known rigid motion. We implemented an iterative algorithm for fully 3D reconstruction from helical CT scans. The motion of the head is incorporated in the system matrix as a view-dependent motion of the CT-system. The first simulation results indicate that some motion patterns may produce loss of essential data. This loss precludes exact reconstruction and results in artifacts in the reconstruction, even when motion is taken into account. However, by reducing the pitch during acquisition, the same motion pattern no longer caused artifacts in the motion corrected image. (orig.)
Rapidity correlations in inclusive two-particle production at storage ring energies

CERN Document Server

Dibon, Heinz; Gottfried, Christian; Nefkens, B M K; Neuhofer, G; Niebergall, F; Regler, Meinhard; Schmidt-Parzefall, W; Schubert, K R; Schumacher, P E; Winter, Klaus

1973-01-01

Inclusive two-particle production in the reaction pp to gamma +ch+ (anything) has been measured at the CERN ISR for four energies ( square root s=23, 30.5, 45, and 53 GeV) at two production angles of the charged particles (ch) and at eight production angles of the gamma -rays. The rapidity correlation of the two particles is weak and of short range. The peak correlation is sigma /sub inel/(d/sup 2/ sigma /sub gamma ch//d sigma /sub gamma /d sigma /sub ch/)-1=0.62+or-0.08, the correlation range (y/sub gamma /-y/sub ch/)=1.17+or-0.05, independently of s. The phi correlation extends over a wide gap in rapidity; its strength is increasing with increasing transverse momentum. (7 refs).
Bio-based rigid polyurethane foam from liquefied products of wood in the presence of polyhydric alcohols

Science.gov (United States)

Zhifeng Zheng; Hui Pan; Yuanbo Huang; Chung Y. Hse

2011-01-01

Rigid polyurethane foams were prepared from the liquefied wood polyols, which was obtained by the liquefaction of southern pine wood in the presence of polyhydric alcohols with sulfuric acid catalyst by using microwave-assistant as an energy source. The properties of liquefied biomass-based polyols and the rigid polyurethane foams were investigated. The results...
Stiffening solids with liquid inclusions

Science.gov (United States)

Style, Robert W.; Boltyanskiy, Rostislav; Allen, Benjamin; Jensen, Katharine E.; Foote, Henry P.; Wettlaufer, John S.; Dufresne, Eric R.

2015-01-01

From bone and wood to concrete and carbon fibre, composites are ubiquitous natural and synthetic materials. Eshelby’s inclusion theory describes how macroscopic stress fields couple to isolated microscopic inclusions, allowing prediction of a composite’s bulk mechanical properties from a knowledge of its microstructure. It has been extended to describe a wide variety of phenomena from solid fracture to cell adhesion. Here, we show experimentally and theoretically that Eshelby’s theory breaks down for small liquid inclusions in a soft solid. In this limit, an isolated droplet’s deformation is strongly size-dependent, with the smallest droplets mimicking the behaviour of solid inclusions. Furthermore, in opposition to the predictions of conventional composite theory, we find that finite concentrations of small liquid inclusions enhance the stiffness of soft solids. A straightforward extension of Eshelby’s theory, accounting for the surface tension of the solid-liquid interface, explains our experimental observations. The counterintuitive stiffening of solids by fluid inclusions is expected whenever inclusion radii are smaller than an elastocapillary length, given by the ratio of the surface tension to Young’s modulus of the solid matrix. These results suggest that surface tension can be a simple and effective mechanism to cloak the far-field elastic signature of inclusions.
Inclusive education and social exclusion

Directory of Open Access Journals (Sweden)

Maria Luisa Bissoto

2013-01-01

Full Text Available The aim of this paper is critically examining assumptions underlying the Inclusive Education concept, arguing that this can only be effectively considered when understood in a broader context of social inclusion and exclusion. Methodologically, this article relies on international documents and bibliographic references about Inclusive Education, that have been chosen by systematize and characterize different social and educational inclusive practices, encouraging the elaboration of a general overview on this topic. The results of this analysis conclude that it is essential for Inclusive Education that educational institutions review their goals and reasons of social existence. In the concluding remarks it is argued that education is better understood as the act of encouraging and welcoming the efforts of individuals in their attempts to engage in social networking, which sustains life. This includes the acceptance of other reality interpretations and understanding that educational action cannot be restricted by the walls of institutions. It requires the participation of the whole community. Action perspectives likely to promote social inclusion and inclusive education are suggested.
Entrywise Squared Transforms for GAMP Supplementary Material

DEFF Research Database (Denmark)

2016-01-01

Supplementary material for a study on Entrywise Squared Transforms for Generalized Approximate Message Passing (GAMP). See the README file for the details.......Supplementary material for a study on Entrywise Squared Transforms for Generalized Approximate Message Passing (GAMP). See the README file for the details....
Distribution of squares modulo a composite number

OpenAIRE

Aryan, Farzad

2015-01-01

In this paper we study the distribution of squares modulo a square-free number $q$. We also look at inverse questions for the large sieve in the distribution aspect and we make improvements on existing results on the distribution of $s$-tuples of reduced residues.
Coherent distributions for the rigid rotator

Energy Technology Data Exchange (ETDEWEB)

Grigorescu, Marius [CP 15-645, Bucharest 014700 (Romania)

2016-06-15

Coherent solutions of the classical Liouville equation for the rigid rotator are presented as positive phase-space distributions localized on the Lagrangian submanifolds of Hamilton-Jacobi theory. These solutions become Wigner-type quasiprobability distributions by a formal discretization of the left-invariant vector fields from their Fourier transform in angular momentum. The results are consistent with the usual quantization of the anisotropic rotator, but the expected value of the Hamiltonian contains a finite “zero point” energy term. It is shown that during the time when a quasiprobability distribution evolves according to the Liouville equation, the related quantum wave function should satisfy the time-dependent Schrödinger equation.
Conformational properties of rigid-chain amphiphilic macromolecules : The phase diagram

NARCIS (Netherlands)

Markov, V. A.; Vasilevskaya, V. V.; Khalatur, P. G.; ten Brinke, G.; Khokhlov, A. R.

The coil-globule transition in rigid-chain amphiphilic macromolecules was studied by means of computer simulation, and the phase diagrams for such molecules in the solvent quality-persistence length coordinates were constructed. It was shown that the type of phase diagram depends to a substantial
RISKS OF INCLUSIVE EDUCATION

Directory of Open Access Journals (Sweden)

M. R. Husnutdinova

2017-01-01

Full Text Available Introduction. Inclusion is a new and unfamiliar phenomenon for most of the Russians which is treated as ensuring equal access to education for all students taking into account a variety of their special educational needs and individual capabilities. Inclusive educational model began to take root in Russia without a broad public debate and today’s parents and teachers were not ready to the cardinal changes caused by transition to the new model of education. In this regard, the studying of directly educational process by consequences of inclusive training and education is urgent now.The aims of the research are the following: to identify the major risks that characterize the current stage of the implementation process of inclusion in the Russian educational organizations; to consider the main causes that lead to their occurrence; to present a comparative analysis of the views of respondents in comprehensive, inclusive and correctional schools. Methodology and research methods. The Sector Monitoring Studies of Moscow State University of Psychology & Education in 2010 and 2014 implemented a sociological study on the process of introduction of inclusion in the Russian schools. 200 teachers and 244 parents were interviewed in 2010; in 2014, in addition, 178 teachers and 386 parents were interviewed; 47 senior students including those with disabilities were interviewed too.Results. According to the results, the main concerns of the parents of students of comprehensive, inclusive and correctional schools are reduced to a few basic risks: lack of individual approach while teaching children with different educational needs, increased emotional pressure on the child, and child’s perception of the complexity of disability as an equal. These risks arise primarily because of the acute shortage of especially prepared-governmental teachers and socio-cultural, psychological unpreparedness of most contemporary children with disabilities to the perception of
Study of rigidity of semiconducting vanadate glasses and its ...

Indian Academy of Sciences (India)

These parameters along with the coordination number of the glasses affect the glass transition temperature. The correlation between the elastic moduli and thermal properties of these samples showed that 0.25MoO3–0.25PbO–0.5V2O5 glass is the most rigid and has an applicable glass transition temperature for coating.
Rigid rod spaced fullerene as building block for nanoclusters

Indian Academy of Sciences (India)

By using phenylacetylene based rigid-rod linkers (PhA), we have successfully synthesized two fullerene derivatives, C60-PhA and C60-PhA-C60. The absorption spectral features of C60, as well as that of the phenylacetylene moiety are retained in the monomeric forms of these fullerene derivatives, ruling out the possibility ...
Knowledge-In-Action: An Example with Rigid Body Motion

Science.gov (United States)

Da Costa, Sayonara Salvador Cabral; Moreira, Marco Antonio

2005-01-01

This paper reports the analysis of the resolution of a paper-and-pencil problem, by eight undergraduate students majoring in engineering (six) and physics (two) at the Pontifcia Universidade Catlica do Rio Grande do Sul, in Porto Alegre, Brazil. The problem concerns kinetics of a rigid body, and the analysis was done in the light of Johnson-Lairds…
Foresighting for Inclusive Development

DEFF Research Database (Denmark)

Andersen, Allan Dahl; Andersen, Per Dannemand

2017-01-01

of policymaking processes affects the actual process with a focus on inclusion, and we discuss how it affects policy effectiveness and innovation system transformation. Our argument is that processes of policymaking must be inclusive to affect and transform innovation systems because a set of distributed actors...... in foresight cases in two emerging economies: Brazil and South Korea. We conclude that better systemic and innovation oriented foresight is needed to enhance inclusive development....
Analyses of polycyclic aromatic hydrocarbon (PAH) and chiral-PAH analogues-methyl-β-cyclodextrin guest-host inclusion complexes by fluorescence spectrophotometry and multivariate regression analysis.

Science.gov (United States)

Greene, LaVana; Elzey, Brianda; Franklin, Mariah; Fakayode, Sayo O

2017-03-05

The negative health impact of polycyclic aromatic hydrocarbons (PAHs) and differences in pharmacological activity of enantiomers of chiral molecules in humans highlights the need for analysis of PAHs and their chiral analogue molecules in humans. Herein, the first use of cyclodextrin guest-host inclusion complexation, fluorescence spectrophotometry, and chemometric approach to PAH (anthracene) and chiral-PAH analogue derivatives (1-(9-anthryl)-2,2,2-triflouroethanol (TFE)) analyses are reported. The binding constants (K b ), stoichiometry (n), and thermodynamic properties (Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS)) of anthracene and enantiomers of TFE-methyl-β-cyclodextrin (Me-β-CD) guest-host complexes were also determined. Chemometric partial-least-square (PLS) regression analysis of emission spectra data of Me-β-CD-guest-host inclusion complexes was used for the determination of anthracene and TFE enantiomer concentrations in Me-β-CD-guest-host inclusion complex samples. The values of calculated K b and negative ΔG suggest the thermodynamic favorability of anthracene-Me-β-CD and enantiomeric of TFE-Me-β-CD inclusion complexation reactions. However, anthracene-Me-β-CD and enantiomer TFE-Me-β-CD inclusion complexations showed notable differences in the binding affinity behaviors and thermodynamic properties. The PLS regression analysis resulted in square-correlation-coefficients of 0.997530 or better and a low LOD of 3.81×10 -7 M for anthracene and 3.48×10 -8 M for TFE enantiomers at physiological conditions. Most importantly, PLS regression accurately determined the anthracene and TFE enantiomer concentrations with an average low error of 2.31% for anthracene, 4.44% for R-TFE and 3.60% for S-TFE. The results of the study are highly significant because of its high sensitivity and accuracy for analysis of PAH and chiral PAH analogue derivatives without the need of an expensive chiral column, enantiomeric resolution, or use of a polarized
Contact point generation for convex polytopes in interactive rigid body dynamics

DEFF Research Database (Denmark)

Silcowitz-Hansen, Morten; Abel, Sarah Maria Niebe; Erleben, Kenny

When computing contact forces in rigid body dynamics systems, most state-of-the-art solutions use iterative methods such as the projected Gauss–Seidel (PGS) method. Methods such as the PGS method are preferred for their robustness. However, the time-critical nature of interactive applications...... combined with the linear convergence rates of such methods, will often result in visual artifacts in the final simulation. With this paper, we address an issue which is of major impact on the animation quality, when using methods such as the PGS method. The issue is robust generation of contact points...... for convex polytopes. A novel contact point generation method is presented, which is based on growth distances and Gauss maps. We demonstrate improvements when using our method in the context of interactive rigid body simulation...
Efficient time-symmetric simulation of torqued rigid bodies using Jacobi elliptic functions

International Nuclear Information System (INIS)

Celledoni, E; Saefstroem, N

2006-01-01

If the three moments of inertia are distinct, the solution to the Euler equations for the free rigid body is given in terms of Jacobi elliptic functions. Using the arithmetic-geometric mean algorithm (Abramowitz and Stegun 1992 Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables (New York: Dover)), these functions can be calculated efficiently and accurately. Compared to standard numerical ODE and Lie-Poisson solvers, the overall approach yields a faster and more accurate numerical solution to the Euler equations. This approach is designed for mass asymmetric rigid bodies. In the case of symmetric bodies, the exact solution is available in terms of trigonometric functions, see Dullweber et al (1997 J. Chem. Phys. 107 5840-51), Reich (1996 Fields Inst. Commun. 10 181-91) and Benettin et al (2001 SIAM J. Sci. Comp. 23 1189-203) for details. In this paper, we consider the case of asymmetric rigid bodies subject to external forces. We consider a strategy similar to the symplectic splitting method proposed in Reich (1996 Fields Inst. Commun. 10 181-91) and Dullweber et al (1997 J. Chem. Phys. 107 5840-51). The method proposed here is time-symmetric. We decompose the vector field of our problem into a free rigid body (FRB) problem and another completely integrable vector field. The FRB problem consists of the Euler equations and a differential equation for the 3 x 3 orientation matrix. The Euler equations are integrated exactly while the matrix equation is approximated using a truncated Magnus series. In our experiments, we observe that the overall numerical solution benefits greatly from the very accurate solution of the Euler equations. We apply the method to the heavy top and the simulation of artificial satellite attitude dynamics
Time Scale in Least Square Method

Directory of Open Access Journals (Sweden)

Özgür Yeniay

2014-01-01

Full Text Available Study of dynamic equations in time scale is a new area in mathematics. Time scale tries to build a bridge between real numbers and integers. Two derivatives in time scale have been introduced and called as delta and nabla derivative. Delta derivative concept is defined as forward direction, and nabla derivative concept is defined as backward direction. Within the scope of this study, we consider the method of obtaining parameters of regression equation of integer values through time scale. Therefore, we implemented least squares method according to derivative definition of time scale and obtained coefficients related to the model. Here, there exist two coefficients originating from forward and backward jump operators relevant to the same model, which are different from each other. Occurrence of such a situation is equal to total number of values of vertical deviation between regression equations and observation values of forward and backward jump operators divided by two. We also estimated coefficients for the model using ordinary least squares method. As a result, we made an introduction to least squares method on time scale. We think that time scale theory would be a new vision in least square especially when assumptions of linear regression are violated.
Plane-wave Least-squares Reverse Time Migration

KAUST Repository

Dai, Wei

2012-11-04

Least-squares reverse time migration is formulated with a new parameterization, where the migration image of each shot is updated separately and a prestack image is produced with common image gathers. The advantage is that it can offer stable convergence for least-squares migration even when the migration velocity is not completely accurate. To significantly reduce computation cost, linear phase shift encoding is applied to hundreds of shot gathers to produce dozens of planes waves. A regularization term which penalizes the image difference between nearby angles are used to keep the prestack image consistent through all the angles. Numerical tests on a marine dataset is performed to illustrate the advantages of least-squares reverse time migration in the plane-wave domain. Through iterations of least-squares migration, the migration artifacts are reduced and the image resolution is improved. Empirical results suggest that the LSRTM in plane wave domain is an efficient method to improve the image quality and produce common image gathers.
Anomalous structural transition of confined hard squares.

Science.gov (United States)

Gurin, Péter; Varga, Szabolcs; Odriozola, Gerardo

2016-11-01

Structural transitions are examined in quasi-one-dimensional systems of freely rotating hard squares, which are confined between two parallel walls. We find two competing phases: one is a fluid where the squares have two sides parallel to the walls, while the second one is a solidlike structure with a zigzag arrangement of the squares. Using transfer matrix method we show that the configuration space consists of subspaces of fluidlike and solidlike phases, which are connected with low probability microstates of mixed structures. The existence of these connecting states makes the thermodynamic quantities continuous and precludes the possibility of a true phase transition. However, thermodynamic functions indicate strong tendency for the phase transition and our replica exchange Monte Carlo simulation study detects several important markers of the first order phase transition. The distinction of a phase transition from a structural change is practically impossible with simulations and experiments in such systems like the confined hard squares.

Competence of Inclusive Practices: ICT and Inclusive Education in Professional Teacher Development

Directory of Open Access Journals (Sweden)

Erika Viviana Laiton Zarate

2017-06-01

Full Text Available The objective of this study was to design the “Competence of Inclusive Practices” which was articulated to the route of the “ICT Competences for Professional Teacher Development,” of the Ministry of Education of Colombia (2013, and thus to fully evaluate 30 teachers of an educational institution in the city of Bucaramanga, in order to recognize their individual or collective training needs, and to formulate appropriate interventions. The research was supported theoretically in guidelines offered by the Ministry of Education of Colombia, the Index for Inclusive Education (Booth and Ainscow, 2011, and empirical researches developed in Latin American countries, including Colombia. The research approach was quantitative, with a descriptive design, which allowed to establish that Inclusive Practices Competence integrated pertinently postures of inclusive education and criteria of the functional framework of Information and Communication Technologies (ICT in education; in addition, it made it possible to know teachers’ perception of the level of competence in relation to the competence level they were (placed; they stated to be located at a low level (explorer in the development of skills for Inclusive Practices Competence.
Finite-difference analysis of shells impacting rigid barriers

International Nuclear Information System (INIS)

Pirotin, S.D.; Witmer, E.A.

1977-01-01

Nuclear power plants must be protected from the adverse effects of missile impacts. A significant category of missile impact involves deformable structures (pressure vessel components, whipping pipes) striking relatively rigid targets (concrete walls, bumpers) which act as protective devices. The response and interaction of these structures is needed to assess the adequacy of these barriers for protecting vital safety related equipment. The present investigation represents an initial attempt to develop an efficient numerical procedure for predicting the deformations and impact force time-histories of shells which impact upon a rigid target. The general large-deflection equations of motion of the shell are expressed in finite-difference form in space and integrated in time through application of the central-difference temporal operator. The effect of material nonlinearities is treated by a mechanical sublayer material model which handles the strain-hardening, Bauschinger, and strain-rate effects. The general adequacy of this shell treatment has been validated by comparing predictions with the results of various experiments in which structures have been subjected to well-defined transient forcing functions (typically high-explosive impulse loading). The 'new' ingredient addressed in the present study involves an accounting for impact interaction and response of both the target structure and the attacking body. (Auth.)
Dynamic response and stability of semi-rigid frames

Science.gov (United States)

Abu-Yasein, Omar Ali

This dissertation presents a method to determine the load capacity as well as end member forces and deformations of frames with partial rigid joint connections by using the direct stiffness method. The connections are modeled as rotational springs attached at the ends of framed members. The lumped mass method, which is an approximate method, and the distributed mass method, which is an exact method, are also presented to compute the natural frequency of frames. The effects of the axial forces and the flexibility of joint connections are both included. Furthermore, the time-dependent response of semi-rigid frames subjected to periodic axial forces is formulated. The harmonic function is approximated by dividing the periodic function into n intervals and the periodic axial forces are evaluated at each time interval as constant forces using 'piecewise approximation'. The regions of instability of frames with different joint stiffness were determined using the characteristic equation method. The time-dependent part of the differential equation for free vibration of a framed member subjected to a harmonic force can be written in the form of the Mathieu-Hill equation where all characteristics of the Mathieu-Hill equation solutions can be used to determine the boundaries of instability regions.
Recent HERMES results from inclusive and semi-inclusive hadron production

Directory of Open Access Journals (Sweden)

Van Hulse Charlotte

2015-01-01

Full Text Available Hermes collected a wealth of data using the 27.6 GeV polarized Hera lepton beam and various pure, polarized and unpolarized, gaseous targets. This unique data set opens the door to various measurements sensitive to the multi-dimensional structure of the nucleon. Among them are two-hadron production in semi-inclusive deep-inelastic scattering on a transversely polarized target, providing access to different transverse-momentum-dependent distribution and fragmentation functions in a way complementary to single-hadron production. Also transverse-target single-spin asymmetries in inclusive electroproduction of charged pions and kaons have been recently extracted, complementing data from proton-proton collisions, where large, so far unexplained, asymmetries have been observed. From inclusive measurements on various nuclear targets, the Λ polarization is extracted, also here complementing measurements in proton-proton collisions.
Least Squares Data Fitting with Applications

DEFF Research Database (Denmark)

Hansen, Per Christian; Pereyra, Víctor; Scherer, Godela

As one of the classical statistical regression techniques, and often the first to be taught to new students, least squares fitting can be a very effective tool in data analysis. Given measured data, we establish a relationship between independent and dependent variables so that we can use the data....... In a number of applications, the accuracy and efficiency of the least squares fit is central, and Per Christian Hansen, Víctor Pereyra, and Godela Scherer survey modern computational methods and illustrate them in fields ranging from engineering and environmental sciences to geophysics. Anyone working...... with problems of linear and nonlinear least squares fitting will find this book invaluable as a hands-on guide, with accessible text and carefully explained problems. Included are • an overview of computational methods together with their properties and advantages • topics from statistical regression analysis...
Removal of inclusions from silicon

Science.gov (United States)

Ciftja, Arjan; Engh, Thorvald Abel; Tangstad, Merete; Kvithyld, Anne; Øvrelid, Eivind Johannes

2009-11-01

The removal of inclusions from molten silicon is necessary to satisfy the purity requirements for solar grade silicon. This paper summarizes two methods that are investigated: (i) settling of the inclusions followed by subsequent directional solidification and (infiltration by ceramic foam filters. Settling of inclusions followed by directional solidification is of industrial importance for production of low-cost solar grade silicon. Filtration is reported as the most efficient method for removal of inclusions from the top-cut silicon scrap.
Financial inclusion: Policies and practices

OpenAIRE

Thankom Arun; Rajalaxmi Kamath

2015-01-01

As a key enabler for development, financial inclusion is firmly placed on the agenda of most governments as a key policy priority. Against this background, this round table provides a global and regional perspective on the policies and practices of financial inclusion. Using macro data, the collection reveals the diversity in the efforts towards achieving financial inclusion and the need for a progressive approach in financial inclusion. Further to this, the round table provides the regional ...
Supporting Teachers in Inclusive Education

Directory of Open Access Journals (Sweden)

Alekhina S.V.

2015-03-01

Full Text Available The article regards the issues of support provision to teachers involved in inclusive education as the main requirement for successful realization of inclusion. The methodological framework used in the study is a resource approach. The article describes the ways of extending the means of supporting teachers. The article also arguments for consolidating all the educators of inclusive schools into inclusive teams equally interested in joint work of administration and educators of intervention programs.
Human epithelial cells increase their rigidity with ageing in vitro: direct measurements

International Nuclear Information System (INIS)

Berdyyeva, Tamara K; Woodworth, Craig D; Sokolov, Igor

2005-01-01

The decrease in elasticity of epithelial tissues with ageing contributes to many human diseases. This change was previously attributed to increased crosslinking of extracellular matrix proteins. Here we show that individual human epithelial cells also become significantly more rigid during ageing in vitro. Using atomic force microscopy (AFM), we found that the Young's modulus of viable cells was consistently increased two- to four-fold in older versus younger cells. Direct visualization of the cytoskeleton using a novel method involving the AFM suggested that increased rigidity of ageing cells was due to a higher density of cytoskeletal fibres. Our results identify a unique mechanism that might contribute to the age-related loss of elasticity in epithelial tissues
Wave energy absorption by a submerged air bag connected to a rigid float

DEFF Research Database (Denmark)

Kurniawan, Adi; Chaplin, J. R.; Hann, M. R.

2017-01-01

A new wave energy device features a submerged ballasted air bag connected at the top to a rigid float. Under wave action, the bag expands and contracts, creating a reciprocating air flow through a turbine between the bag and another volume housed within the float. Laboratory measurements are gene......A new wave energy device features a submerged ballasted air bag connected at the top to a rigid float. Under wave action, the bag expands and contracts, creating a reciprocating air flow through a turbine between the bag and another volume housed within the float. Laboratory measurements...
INCLUSIVE EDUCATION IN ITALY

OpenAIRE

Voitkāne, Vita

2017-01-01

European member States implement Inclusive Education policies thus contributing to a sustainable, inclusive society, although each country is at a different stage in this process. Italy, one of the first countries to launch integrative learning, has set an example since the 1970s, although the quality of inclusive education is unpredictable due to many issues. Authors Cantoni and Panetta (2006) emphasize that, although the culture of integration in Italy exists, much needs to be done to impro...
Inclusion-Body Myositis: Diagnosis

Science.gov (United States)

... for MDA Blog Donate Search MDA.org Close Inclusion-Body Myositis (IBM) Diagnosis As with other muscle diseases, a doctor diagnoses inclusion-body myositis (IBM) by considering the individual’s personal ...
Lending a Helping Hand at Work: A Multilevel Investigation of Prosocial Motivation, Inclusive Climate and Inclusive Behavior.

Science.gov (United States)

Nelissen, Philippe T J H; Hülsheger, Ute R; van Ruitenbeek, Gemma M C; Zijlstra, Fred R H

2017-09-01

Purpose People with disabilities often encounter difficulties at the workplace such as exclusion or unfair treatment. Researchers have therefore pointed to the need to focus on behavior that fosters inclusion as well as variables that are antecedents of such 'inclusive behavior'. Therefore the purpose of this study was to research the relationship between prosocial motivation, team inclusive climate and employee inclusive behavior. Method A survey was conducted among a sample of 282 paired employees and colleagues, which were nested in 84 teams. Employees self-rated prosocial motivation and team inclusive climate, their inclusive behavior was assessed by colleagues. Hypotheses were tested using multilevel random coefficient modeling. Results Employees who are prosocially motivated will display more inclusive behavior towards people with disabilities, and this relationship is moderated by team inclusive climate in such a way that the relationship is stronger when the inclusive climate is high. Conclusion This study shows that inclusive organizations, which value a diverse workforce, need to be aware of not only individual employee characteristics, but also team level climate to ensure the smooth integrations of people with disabilities into regular work teams.
Inclusion control in high-performance steels

International Nuclear Information System (INIS)

Holappa, L.E.K.; Helle, A.S.

1995-01-01

Progress of clean steel production, fundamentals of oxide and sulphide inclusions as well as inclusion morphology in normal and calcium treated steels are described. Effects of cleanliness and inclusion control on steel properties are discussed. In many damaging constructional and engineering applications the nonmetallic inclusions have a quite decisive role in steel performance. An example of combination of good mechanical properties and superior machinability by applying inclusion control is presented. (author)
NOLB: Nonlinear Rigid Block Normal Mode Analysis Method

OpenAIRE

Hoffmann , Alexandre; Grudinin , Sergei

2017-01-01

International audience; We present a new conceptually simple and computationally efficient method for nonlinear normal mode analysis called NOLB. It relies on the rotations-translations of blocks (RTB) theoretical basis developed by Y.-H. Sanejouand and colleagues. We demonstrate how to physically interpret the eigenvalues computed in the RTB basis in terms of angular and linear velocities applied to the rigid blocks and how to construct a nonlinear extrapolation of motion out of these veloci...
Soft-rigid interaction mechanism towards a lobster-inspired hybrid actuator

Science.gov (United States)

Chen, Yaohui; Wan, Fang; Wu, Tong; Song, Chaoyang

2018-01-01

Soft pneumatic actuators (SPAs) are intrinsically light-weight, compliant and therefore ideal to directly interact with humans and be implemented into wearable robotic devices. However, they also pose new challenges in describing and sensing their continuous deformation. In this paper, we propose a hybrid actuator design with bio-inspirations from the lobsters, which can generate reconfigurable bending movements through the internal soft chamber interacting with the external rigid shells. This design with joint and link structures enables us to exactly track its bending configurations that previously posed a significant challenge to soft robots. Analytic models are developed to illustrate the soft-rigid interaction mechanism with experimental validation. A robotic glove using hybrid actuators to assist grasping is assembled to illustrate their potentials in safe human-robot interactions. Considering all the design merits, our work presents a practical approach to the design of next-generation robots capable of achieving both good accuracy and compliance.
Jet Ventilation during Rigid Bronchoscopy in Adults: A Focused Review

Directory of Open Access Journals (Sweden)

Laurie Putz

2016-01-01

Full Text Available The indications for rigid bronchoscopy for interventional pulmonology have increased and include stent placements and transbronchial cryobiopsy procedures. The shared airway between anesthesiologist and pulmonologist and the open airway system, requiring specific ventilation techniques such as jet ventilation, need a good understanding of the procedure to reduce potentially harmful complications. Appropriate adjustment of the ventilator settings including pause pressure and peak inspiratory pressure reduces the risk of barotrauma. High frequency jet ventilation allows adequate oxygenation and carbon dioxide removal even in cases of tracheal stenosis up to frequencies of around 150 min−1; however, in an in vivo animal model, high frequency jet ventilation along with normal frequency jet ventilation (superimposed high frequency jet ventilation has been shown to improve oxygenation by increasing lung volume and carbon dioxide removal by increasing tidal volume across a large spectrum of frequencies without increasing barotrauma. General anesthesia with a continuous, intravenous, short-acting agent is safe and effective during rigid bronchoscopy procedures.
Dynamics of parallel robots from rigid bodies to flexible elements

CERN Document Server

Briot, Sébastien

2015-01-01

This book starts with a short recapitulation on basic concepts, common to any types of robots (serial, tree structure, parallel, etc.), that are also necessary for computation of the dynamic models of parallel robots. Then, as dynamics requires the use of geometry and kinematics, the general equations of geometric and kinematic models of parallel robots are given. After, it is explained that parallel robot dynamic models can be obtained by decomposing the real robot into two virtual systems: a tree-structure robot (equivalent to the robot legs for which all joints would be actuated) plus a free body corresponding to the platform. Thus, the dynamics of rigid tree-structure robots is analyzed and algorithms to obtain their dynamic models in the most compact form are given. The dynamic model of the real rigid parallel robot is obtained by closing the loops through the use of the Lagrange multipliers. The problem of the dynamic model degeneracy near singularities is treated and optimal trajectory planning for cro...
Inclusion in a Polarised World

OpenAIRE

Freeman, Alan

2005-01-01

This paper on inclusion was presented to the at the 2005 summer school of DEEEP (Development Education Exchange in Europe Project), Härnösand - Sweden, 5 - 12 June 2005. It addresses the significance of the concept of world civilisation. It assesses how meaning may be attached to the concept of inclusion in an economically polarised world. It develops a critique of the conception of economic inclusion, by means of an exploration of linguistic inclusion and the notion of ‘disability’. ‘...
Modeling of a light elastic beam by a system of rigid bodies

Directory of Open Access Journals (Sweden)

Šalinić Slaviša

2004-01-01

Full Text Available This paper has shown that a light elastic beam, in the case of small elastic deformations, can be modeled by a kinematic chain without branching composed of rigid bodies which are connected by passive revolute or prismatic joints with corresponding springs in them. Elastic properties of the beam are modeled by the springs introduced. The potential energy of the elastic beam is expressed as a function of components of the vector of elastic displacement and the vector of elastic rotation calculated for the elastic centre of the beam, which results in the diagonal stiffness matrix of the beam. As the potential energy of the introduced system of bodies with springs is expressed in the function of relative joint displacements, the diagonal stiffness matrix is obtained. In addition, these two stiffness matrices are equal. The modeling process has been demonstrated on the example of an elastic beam rotating about a fixed vertical axis, with a rigid body whose mass is considerably larger than the beam mass fixed to its free end. Differential equations of motion have been formed for this mechanical system. The modeling technique described here aims at expanding of usage of well developed methods of dynamics of systems of rigid bodies to the analysis of systems with elastic bodies. .

Influence of RNA Strand Rigidity on Polyion Complex Formation with Block Catiomers.

Science.gov (United States)

Hayashi, Kotaro; Chaya, Hiroyuki; Fukushima, Shigeto; Watanabe, Sumiyo; Takemoto, Hiroyasu; Osada, Kensuke; Nishiyama, Nobuhiro; Miyata, Kanjiro; Kataoka, Kazunori

2016-03-01

Polyion complexes (b-PICs) are prepared by mixing single- or double-stranded oligo RNA (aniomer) with poly(ethylene glycol)-b-poly(L-lysine) (PEG-PLL) (block catiomer) to clarify the effect of aniomer chain rigidity on association behaviors at varying concentrations. Here, a 21-mer single-stranded RNA (ssRNA) (persistence length: 1.0 nm) and a 21-mer double-stranded RNA (small interfering RNA, siRNA) (persistence length: 62 nm) are compared. Both oligo RNAs form a minimal charge-neutralized ionomer pair with a single PEG-PLL chain, termed unit b-PIC (uPIC), at low concentrations (<≈ 0.01 mg mL(-1)). Above the critical association concentration (≈ 0.01 mg mL(-1)), ssRNA b-PICs form secondary associates, PIC micelles, with sizes up to 30-70 nm, while no such multimolecular assembly is observed for siRNA b-PICs. The entropy gain associated with the formation of a segregated PIC phase in the multimolecular PIC micelles may not be large enough for rigid siRNA strands to compensate with appreciably high steric repulsion derived from PEG chains. Chain rigidity appears to be a critical parameter in polyion complex association. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Closure of the squared Zakharov--Shabat eigenstates

International Nuclear Information System (INIS)

Kaup, D.J.

1976-01-01

By solution of the inverse scattering problem for a third-order (degenerate) eigenvalue problem, the closure of the squared eigenfunctions of the Zakharov--Shabat equations is found. The question of the completeness of squared eigenstates occurs in many aspects of ''inverse scattering transforms'' (solving nonlinear evolution equations exactly by inverse scattering techniques), as well as in various aspects of the inverse scattering problem. The method used here is quite suggestive as to how one might find the closure of the squared eigenfunctions of other eigenvalue equations, and the strong analogy between these results and the problem of finding the closure of the eigenvectors of a nonself-adjoint matrix is pointed out
Integrating NOE and RDC using sum-of-squares relaxation for protein structure determination.

Science.gov (United States)

Khoo, Y; Singer, A; Cowburn, D

2017-07-01

We revisit the problem of protein structure determination from geometrical restraints from NMR, using convex optimization. It is well-known that the NP-hard distance geometry problem of determining atomic positions from pairwise distance restraints can be relaxed into a convex semidefinite program (SDP). However, often the NOE distance restraints are too imprecise and sparse for accurate structure determination. Residual dipolar coupling (RDC) measurements provide additional geometric information on the angles between atom-pair directions and axes of the principal-axis-frame. The optimization problem involving RDC is highly non-convex and requires a good initialization even within the simulated annealing framework. In this paper, we model the protein backbone as an articulated structure composed of rigid units. Determining the rotation of each rigid unit gives the full protein structure. We propose solving the non-convex optimization problems using the sum-of-squares (SOS) hierarchy, a hierarchy of convex relaxations with increasing complexity and approximation power. Unlike classical global optimization approaches, SOS optimization returns a certificate of optimality if the global optimum is found. Based on the SOS method, we proposed two algorithms-RDC-SOS and RDC-NOE-SOS, that have polynomial time complexity in the number of amino-acid residues and run efficiently on a standard desktop. In many instances, the proposed methods exactly recover the solution to the original non-convex optimization problem. To the best of our knowledge this is the first time SOS relaxation is introduced to solve non-convex optimization problems in structural biology. We further introduce a statistical tool, the Cramér-Rao bound (CRB), to provide an information theoretic bound on the highest resolution one can hope to achieve when determining protein structure from noisy measurements using any unbiased estimator. Our simulation results show that when the RDC measurements are
Diverse Perspectives on Inclusive School Communities

Science.gov (United States)

Tsokova, Diana; Tarr, Jane

2012-01-01

What is an inclusive school community? How do stakeholders perceive their roles and responsibilities towards inclusive school communities? How can school communities become more inclusive through engagement with individual perspectives? "Diverse Perspectives on Inclusive School Communities" captures and presents the voices of a wide…
Análise comparativa da resistência de fêmures de cães após a confecção de janelas ósseas circular e quadrada Comparative analysis of dog femur resistance after receiving circular and square holes

Directory of Open Access Journals (Sweden)

Olavo Pires de Camargo

2002-06-01

Full Text Available Com o objetivo de avaliar o enfraquecimento causado pela confecção de janela óssea cortical, os autores confeccionaram uma janela circular no osso cortical da diáfise de oito fêmures de carcaças de cães e uma janela quadrada nos oito pares destes fêmures, com diagonal semelhante ao diâmetro da janela circular contralateral. As peças anatômicas foram submetidas a teste de tensão torcional em uma máquina de ensaios mecânicos; obtendo-se o torque máximo e a rigidez à torção. Os resultados mostraram que, para o fêmur com janela circular, o torque máximo médio foi de 13,65 ± 5,12 Nm, e a rigidez média foi de 1,18 ± 0,45 Nm/grau, enquanto que para a janela quadrada o torque máximo médio foi de 13, 39 ± 5,23 Nm, e a rigidez média foi de 1,05 ± 0,41 Nm/grau. A resistência nos ossos com janela circular e quadrada submetidos à tensão torcional foi praticamente igual, fato este corroborado pela análise estatística que não revelou diferença significante (p = 0,05.With the purpose of evaluating the weakness caused by holes in the cortical bone, the authors performed circular holes in the diaphysis cortical bone of eight femurs from dog carcasses, and square holes in the diaphysis cortical bone of the contralateral femurs, the diagonals being similar to the diameters. The specimens were submitted to torsion stress test in a mechanical test machine to determine maximum torque and rigidity to torsion. Maximum mean torque for the femurs with circular holes was 13.65 ± 5.12 Nm and mean rigidity was 1.18 ± 0.45 Nm/degree, while the femurs with square holes showed maximum mean torque of 13.39 ± 5.23 Nm and mean rigidity of 1.05 ± 0.41 Nm/degree. The resistance to torsion stress in femurs with circular or square holes was very similar and the statistical analysis did not show a significant difference (p = 0.05.
The evaluation of cutoff rigidities and reentrant albedo calculations for Palestine, Dallas, and Midland, Texas

International Nuclear Information System (INIS)

Shea, M.A.; Smart, D.F.

1975-01-01

By using the trajectory-tracing technique, cutoff rigidities for Palestine, Dallas, and Midland, Texas, have been calculated as a function of various zenith and azimuth angles. Extensive analysis of the trajectory calculations shows that there is a systematic uncertainty involved in computing the lowest allowed rigidity, and this uncertainty may be a significant fraction of the penumbral width. Continuation of the trajectory-tracing process below the Stormer cutoff allows an evaluation of the reentrant albedo, showing that the average invariant latitude of the guiding center of the trajectory at the albedo origin is the same as the average invariant latitude of the guiding center of the particle trajectory at the detection point. No significant difference in the cutoff rigidities for these locations is found when the external magnetic fields present in the magnetosphere are added to the geomagnetic field of internal origin
Thermal insulating materials consisting of polyurethane rigid foam. Production - application - properties. 2. ed.; Waermedaemmstoffe aus Polyurethan-Hartschaum. Herstellung - Anwendung - Eigenschaften

Energy Technology Data Exchange (ETDEWEB)

Endres, Edmund; Kleser, Joachim

2008-02-15

Using rigid polyurethane (PU) / polyisocyanurate (PIR) foam as a thermal insulation material enables a conservation of resources and energy conservation. Environmentally harmful emissions significantly are reduced. Under this aspect, the authors of the contribution report on the production, application, technical and physical properties of rigid polyurethane foams. Sustainable construction with rigid polyurethane foam, quality assurance and product certification are further topics of this paper.
Hierarchical and successive approximate registration of the non-rigid medical image based on thin-plate splines

Science.gov (United States)

Hu, Jinyan; Li, Li; Yang, Yunfeng

2017-06-01

The hierarchical and successive approximate registration method of non-rigid medical image based on the thin-plate splines is proposed in the paper. There are two major novelties in the proposed method. First, the hierarchical registration based on Wavelet transform is used. The approximate image of Wavelet transform is selected as the registered object. Second, the successive approximation registration method is used to accomplish the non-rigid medical images registration, i.e. the local regions of the couple images are registered roughly based on the thin-plate splines, then, the current rough registration result is selected as the object to be registered in the following registration procedure. Experiments show that the proposed method is effective in the registration process of the non-rigid medical images.
Teachers becoming inclusive practitioners

African Journals Online (AJOL)

, construct their identities in the light of inclusive education, and how they negotiate the tensions and contradictions emerging from the processof becoming inclusive practitioners. Central to this discussion is the understanding that teachers' ...
A review of social inclusion measures.

Science.gov (United States)

Coombs, Tim; Nicholas, Angela; Pirkis, Jane

2013-10-01

Social inclusion is crucial to mental health and well-being and is emphasised in Australia's Fourth National Mental Health Plan. There is a recognition that a measure of social inclusion would complement the suite of outcome measures that is currently used in public sector mental health services. This paper is an initial scope of candidate measures of social inclusion and considers their suitability for this purpose. We identified potential measures through searches of PsycINFO and Medline and a more general Internet search. We extracted descriptive and evaluative information on each measure identified and compared this information with a set of eight criteria. The criteria related to the measure's inclusion of four domains of social inclusion outlined in Australia's Fourth National Mental Health Plan, its usability within the public mental health sector and its psychometric properties. We identified 10 candidate measures of social inclusion: the Activity and Participation Questionnaire (APQ-6); the Australian Community Participation Questionnaire (ACPQ); the Composite Measure of Social Inclusion (CMSI); the EMILIA Project Questionnaire (EPQ); the Evaluating Social Inclusion Questionnaire (ESIQ); the Inclusion Web (IW); the Social and Community Opportunities Profile (SCOPE); the Social Inclusion Measure (SIM); the Social Inclusion Questionnaire (SIQ); and the Staff Survey of Social Inclusion (SSSI). After comparison with the eight review criteria, we determined that the APQ-6 and the SCOPE-short form show the most potential for further testing. Social inclusion is too important not to measure. This discussion of individual-level measures of social inclusion provides a springboard for selecting an appropriate measure for use in public sector mental health services. It suggests that there are two primary candidates, but neither of these is quite fit-for-purpose in their current form. Further exploration will reveal whether one of these is suitable, whether another
Inclusão digital via acessibilidade web | Digital inclusion via web accessibility

Directory of Open Access Journals (Sweden)

Cesar Augusto Cusin

2009-03-01

Full Text Available Resumo A natureza atual da web, que destaca a participação colaborativa dos usuários em diversos ambientes informacionais digitais, conduz ao desenvolvimento de diretrizes que enfocam a arquitetura da informação digital inclusiva para diferentes públicos nas mais diversas ambiências informacionais. A pesquisa propõe e objetiva um ambiente informacional digital inclusivo, visando apontar os elementos de acessibilidade que permitam a promoção da inclusão informacional digital, de forma a destacar os referenciais da Arquitetura da Informação Digital, de recomendações internacionais, com o olhar da Ciência da Informação e das novas tecnologias de informação e comunicação (TIC. Palavras-chave inclusão digital; web; acessibilidade; ciência da informação; arquitetura da informação. Abstract The current nature of the web, which highlights the collaborative participation of users in various digital informational environments, leads to the development of guidelines that focus on the digital inclusive information architecture for different audiences in diverse informational environments. The study proposes an inclusive digital information environment, aiming to establish the elements of accessibility that enable the promotion of digital inclusion information in order to highlight the references of digital information architecture, the international recommendations, with the perspective of Information Science and the new information and communication technologies (ICT. Keywords digital inclusion; web; accessibility; information science; information architecture.
An Arendtian perspective on inclusive education

DEFF Research Database (Denmark)

Korsgaard, Morten Timmermann

2016-01-01

Inclusive education currently appears to be undergoing a crisis and re- examination. This paper presents a new approach to thinking about inclusiveness in the school context. Many positions within inclusive education seem to take political, social and ethical perspectives as a starting point, which...... has allowed inclusive movements and initiatives around the world to succumb to neo-liberal policy-making and has neglected the development of an educational vocabulary that is theoretically and conceptually appropriate for confronting teachers’ central concerns regarding inclusive practices....... The concepts of suspension, bearing with strangers and enlarged thought inspired by Hannah Arendt provide a basis for a re-imagining of inclusive education and for outlining a future school in which inclusiveness is embedded in the very way we think and position ourselves as teachers and pupils...
Elucidating fluctuating diffusivity in center-of-mass motion of polymer models with time-averaged mean-square-displacement tensor

Science.gov (United States)

Miyaguchi, Tomoshige

2017-10-01

There have been increasing reports that the diffusion coefficient of macromolecules depends on time and fluctuates randomly. Here a method is developed to elucidate this fluctuating diffusivity from trajectory data. Time-averaged mean-square displacement (MSD), a common tool in single-particle-tracking (SPT) experiments, is generalized to a second-order tensor with which both magnitude and orientation fluctuations of the diffusivity can be clearly detected. This method is used to analyze the center-of-mass motion of four fundamental polymer models: the Rouse model, the Zimm model, a reptation model, and a rigid rodlike polymer. It is found that these models exhibit distinctly different types of magnitude and orientation fluctuations of diffusivity. This is an advantage of the present method over previous ones, such as the ergodicity-breaking parameter and a non-Gaussian parameter, because with either of these parameters it is difficult to distinguish the dynamics of the four polymer models. Also, the present method of a time-averaged MSD tensor could be used to analyze trajectory data obtained in SPT experiments.
Adapting Evidence-Based Teen Pregnancy Programs to Be LGBT-Inclusive: Lessons Learned.

Science.gov (United States)

Boyce, Karen Stradford; Travers, Madeline; Rothbart, Betty; Santiago, Vivian; Bedell, Jane

2018-05-01

Lesbian, gay, bisexual, and transgender (LGBT) youth show higher rates of sexual risk behaviors than heterosexual and cisgender youth; yet, most school-based sexual health education is largely heteronormative and cisnormative and does not recognize the spectrum of sexual and gender identity. New York City's Departments of Health and Education collaborated to create an LGBT-inclusive supplement to the Reducing the Risk curriculum and implement it in 21 South Bronx high schools. Teachers completed an electronic survey to report the number of students reached and an online log to measure curriculum adherence. Students were administered an anonymous 74-item pre- and posttest to measure demographics, sexual health knowledge, and student satisfaction with the curriculum. Chi-square and t tests were used to assess differences in student demographics and changes in knowledge scores. Reducing the Risk was implemented in 21 schools reaching 230 classes and 5,673 students; with 161 classes receiving the supplement. Teachers reported completing an average of 70% of LGBT supplement activities. Students who received the supplement reported higher satisfaction and greater knowledge scores than students who did not. New York City experience shows that being more inclusive of LGBT teens while implementing preexisting evidence-based sexual and reproductive health programs is possible and replicable.
Fiber Optic Systems for Light Curing Rigidization of Inflatable Structures, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Light (UV and visible) curing composite matrix resins are being explored as an attractive means for rigidizing inflatable spacecraft for large space-deployed...
Analysis of the spatial structure of rigid polyphenylene dendrimers by small-angle neutron scattering

International Nuclear Information System (INIS)

Rosenfeldt, S.; Dingenouts, N.; Poetschke, D.; Ballauff, M.; Berresheim, A.J.; Muellen, K.; Lindner, P.; Saalwaechter, K.

2005-01-01

The analysis of the spatial structure of a rigid polyphenylene dendrimer G4-M of fourth generation by small-angle neutron scattering (SANS) is presented. This dendrimer is composed of phenyl units and is therefore devoid of any flexible unit. The scattering intensity of dilute solutions of the dendrimer was measured by SANS at different contrast which was adjusted by mixtures of protonated and deuterated toluene. Hence, the method of contrast variation could be applied and the data yield the scattering function extrapolated to infinite contrast. The comparison of this data with simulations demonstrates that the scaffold of the dendrimer is rigid as expected from its chemical structure. The positions of the various units setting up consecutive shells of the dendrimer are relatively well localized and the entire structure cannot be modeled in terms of spherically symmetric models. No backfolding of the terminal groups can occur and the model calculations demonstrate that higher generations of this dendritic scaffold must exhibit a dense shell and a congestion of the terminal groups. This finding is directly corroborated by recent solid-state NMR data. All results show that the rigid dendrimer investigated here presents the first example for a dendritic structure whose segment density does not have its maximum at the center. Rigid scaffolds are therefore the only way to achieve the goal of a 'dense-shell' dendrimer whereas flexible scaffolds leads invariably to the 'dense-core' case
Inclusive Education under Collectivistic Culture

Science.gov (United States)

Futaba, Yasuko

2016-01-01

This paper addresses how inclusive education under collective culture is possible. Inclusive education, which more-or-less involves changing the current schools, has been denied, doubted or distorted by both policy-makers and practitioners of general and special education in Japan. Main reason for the setback in inclusive education can be…
In situ Neutron Diffraction during Casting: Determination of Rigidity Point in Grain Refined Al-Cu Alloys.

Science.gov (United States)

Drezet, Jean-Marie; Mireux, Bastien; Szaraz, Zoltan; Pirling, Thilo

2014-02-12

The rigidity temperature of a solidifying alloy is the temperature at which the solid plus liquid phases are sufficiently coalesced to transmit long range tensile strains and stresses. It determines the point at which thermally induced deformations start to generate internal stresses in a casting. As such, it is a key parameter in numerical modelling of solidification processes and in studying casting defects such as solidification cracking. This temperature has been determined in Al-Cu alloys using in situ neutron diffraction during casting in a dog bone shaped mould. In such a setup, the thermal contraction of the solidifying material is constrained and stresses develop at a hot spot that is irradiated by neutrons. Diffraction peaks are recorded every 11 s using a large detector, and their evolution allows for the determination of the rigidity temperatures. We measured rigidity temperatures equal to 557 °C and 548 °C, depending on cooling rate, for a grain refined Al-13 wt% Cu alloy. At high cooling rate, rigidity is reached during the formation of the eutectic phase and the solid phase is not sufficiently coalesced, i.e. , strong enough, to avoid hot tear formation.
In situ Neutron Diffraction during Casting: Determination of Rigidity Point in Grain Refined Al-Cu Alloys

Directory of Open Access Journals (Sweden)

Jean-Marie Drezet

2014-02-01

Full Text Available The rigidity temperature of a solidifying alloy is the temperature at which the solid plus liquid phases are sufficiently coalesced to transmit long range tensile strains and stresses. It determines the point at which thermally induced deformations start to generate internal stresses in a casting. As such, it is a key parameter in numerical modelling of solidification processes and in studying casting defects such as solidification cracking. This temperature has been determined in Al-Cu alloys using in situ neutron diffraction during casting in a dog bone shaped mould. In such a setup, the thermal contraction of the solidifying material is constrained and stresses develop at a hot spot that is irradiated by neutrons. Diffraction peaks are recorded every 11 s using a large detector, and their evolution allows for the determination of the rigidity temperatures. We measured rigidity temperatures equal to 557 °C and 548 °C, depending on cooling rate, for a grain refined Al-13 wt% Cu alloy. At high cooling rate, rigidity is reached during the formation of the eutectic phase and the solid phase is not sufficiently coalesced, i.e., strong enough, to avoid hot tear formation.
Multiplicity and pseudorapidity distributions of photons in Au+Au collisions at square root of (S(NN)) = 62.4 GeV.

Science.gov (United States)

Adams, J; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Badyal, S K; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Billmeier, A; Bland, L C; Blyth, C O; Blyth, S; Bonner, B E; Botje, M; Boucham, A; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; de la Barca Sánchez, M Calderón; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; de Moura, M M; Dedovich, T G; Derevschikov, A A; Didenko, L; Dietel, T; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Mazumdar, M R Dutta; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fornazier, K S F; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Gos, H; Grachov, O; Grebenyuk, O; Grosnick, D; Guertin, S M; Guo, Y; Gupta, A; Gutierrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horner, M; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Jedynak, M; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kowalik, K L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lehocka, S; Levine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Miller, M L; Minaev, N G; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Reinnarth, J; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimanskiy, S S; Sichtermann, E; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Swanger, M; Symons, T J M; de Toledo, A Szanto; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Buren, G Van; van Leeuwen, M; Molen, A M Vander; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, G; Wang, X L; Wang, Y; Wang, Y; Wang, Z M; Ward, H; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zborovsky, I; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N

2005-08-05

We present the first measurement of pseudorapidity distribution of photons in the region 2.3 < or = eta < or = 3.7 for different centralities in Au+Au collisions at square root of (S(NN)) = 62.4 GeV. We find that the photon yield scales with the number of participating nucleons at all collision centralities studied. The pseudorapidity distribution of photons, dominated by pi0 decays, has been compared to those of charged pions, photons, and inclusive charged particles from heavy-ion and nucleon-nucleon collisions at various energies. The photon production has been shown to be consistent with the energy and centrality independent limiting fragmentation scenario.

A model for an acoustically driven microbubble inside a rigid tube

KAUST Repository

Qamar, Adnan; Samtaney, Ravi

2014-01-01

A theoretical framework to model the dynamics of acoustically driven microbubble inside a rigid tube is presented. The proposed model is not a variant of the conventional Rayleigh-Plesset category of models. It is derived from the reduced Navier
Positive semidefinite matrix completion, universal rigidity and the Strong Arnold Property

NARCIS (Netherlands)

M. Laurent (Monique); A. Varvitsiotis (Antonios)

2014-01-01

htmlabstractThis paper addresses the following three topics: positive semidefinite (psd) matrix completions, universal rigidity of frameworks, and the Strong Arnold Property (SAP). We show some strong connections among these topics, using semidefinite programming as unifying theme. Our main
Inclusive Education in South Korea

Science.gov (United States)

Kim, Yong-Wook

2014-01-01

The purpose of this paper is to examine the current implementation of inclusive education in South Korea and discuss its challenges. The history of special education is first described followed by an introduction to policies relevant to special and inclusive education. Next, a critical discussion of the state of inclusive education follows built…
Roadmap for Inclusive Innovation

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Roadmap for Inclusive Innovation data set shares the status of action items under the Roadmap for Inclusive Innovation. Each action or project has been assigned...
Oscillations of manometric tubular springs with rigid end

Science.gov (United States)

Cherentsov, D. A.; Pirogov, S. P.; Dorofeev, S. M.; Ryabova, Y. S.

2018-05-01

The paper presents a mathematical model of attenuating oscillations of manometric tubular springs (MTS) taking into account the rigid tip. The dynamic MTS model is presented in the form of a thin-walled curved rod oscillating in the plane of curvature of the central axis. Equations for MTS oscillations are obtained in accordance with the d’Alembert principle in projections onto the normal and tangential. The Bubnov-Galerkin method is used to solve the equations obtained.
Gas-induced friction and diffusion of rigid rotors

Science.gov (United States)

Martinetz, Lukas; Hornberger, Klaus; Stickler, Benjamin A.

2018-05-01

We derive the Boltzmann equation for the rotranslational dynamics of an arbitrary convex rigid body in a rarefied gas. It yields as a limiting case the Fokker-Planck equation accounting for friction, diffusion, and nonconservative drift forces and torques. We provide the rotranslational friction and diffusion tensors for specular and diffuse reflection off particles with spherical, cylindrical, and cuboidal shape, and show that the theory describes thermalization, photophoresis, and the inverse Magnus effect in the free molecular regime.
MAGIC MOORE-PENROSE INVERSES AND PHILATELIC MAGIC SQUARES WITH SPECIAL EMPHASIS ON THE DANIELS–ZLOBEC MAGIC SQUARE

Directory of Open Access Journals (Sweden)

Ka Lok Chu

2011-02-01

Full Text Available We study singular magic matrices in which the numbers in the rows and columns and in the two main diagonals all add up to the same sum. Our interest focuses on such magic matrices for which the Moore–Penrose inverse is also magic. Special attention is given to the “Daniels–Zlobec magic square’’ introduced by the British magician and television performer Paul Daniels (b. 1938 and considered by Zlobec (2001; see also Murray (1989, pp. 30–32. We introduce the concept of a “philatelic magic square” as a square arrangement of images of postage stamps so that the associated nominal values form a magic square. Three philatelic magic squares with stamps especially chosen for Sanjo Zlobec are presented in celebration of his 70th birthday; most helpful in identifying these stamps was an Excel checklist by Männikkö (2009.
Square Stent: A New Self-Expandable Endoluminal Device and Its Applications

International Nuclear Information System (INIS)

Pavcnik, Dusan; Uchida, Barry; Timmermans, Hans; Keller, Frederick S.; Roesch, Josef

2001-01-01

The square stent is a new, simply constructed, self-expanding device that has recently been described. Compared with other stents, the square stent has a minimal amount of metal and thus requires a smaller-diameter catheter for introduction. Despite the small amount of metal present, the square stent has adequate expansile force. We have been evaluating the square stent for various interventional applications. In addition to the basic square stent, combinations of square stents and coverings for square stents were developed and evaluated to expand its uses and indications. One of the coverings tested is a new biomaterial: small intestinal submucosa (SIS). This paper will discuss the various applications of the square stent, which include a retrievable inferior vena cava filter, vascular occluder, graft adapter, and venous and aortic valves. In addition, we will review the important properties of SIS as a covering for the square stent
Enumeration of self-avoiding walks on the square lattice

International Nuclear Information System (INIS)

Jensen, Iwan

2004-01-01

We describe a new algorithm for the enumeration of self-avoiding walks on the square lattice. Using up to 128 processors on a HP Alpha server cluster we have enumerated the number of self-avoiding walks on the square lattice to length 71. Series for the metric properties of mean-square end-to-end distance, mean-square radius of gyration and mean-square distance of monomers from the end points have been derived to length 59. An analysis of the resulting series yields accurate estimates of the critical exponents γ and ν confirming predictions of their exact values. Likewise we obtain accurate amplitude estimates yielding precise values for certain universal amplitude combinations. Finally we report on an analysis giving compelling evidence that the leading non-analytic correction-to-scaling exponent Δ 1 = 3/2
49 CFR 178.925 - Standards for rigid plastic Large Packagings.

Science.gov (United States)

2010-10-01

... manufacture of the tested design type, retesting may be omitted if changes in the carbon black content, the... or chemical properties of the material of construction. (3) No used material other than production residues or regrind from the same manufacturing process may be used in the manufacture of rigid plastic...
Physical properties of aqueous mixtures of the ionic 1-ethl-3-methyl imidazolium octyl sulfate: A new ionic rigid gel

International Nuclear Information System (INIS)

Cabeza, O.; Vila, J.; Rilo, E.; Domínguez-Pérez, M.; Otero-Cernadas, L.; López-Lago, E.; Méndez-Morales, T.; Varela, L.M.

2014-01-01

Graphical abstract: Phase diagram indicating three transitions temperatures: (liquid + gel) (dot symbols), (liquid + crystal) (square symbols) and (crystal + liquid) (triangle symbols) for the aqueous EMIM-OS mixtures. - Highlights: • We present the phase diagram of the system EMIM-octyl sulfate + water. • We show that a rigid gel phase appears for certain concentrations and temperatures. • That gel presents a smectic-like phase, being really a rigid gel crystal. • The gel is as electrical conductive as the liquid in spite of the viscosity change. • Density does not change at the (liquid + gel) transition. - Abstract: We report the existence of hydrophobically driven lyotropic rigid gel phase in aqueous mixtures of the ionic liquid (IL) 1-ethyl-3-methyl imidazolium octyl sulfate (EMIM-OS), and we characterize the physical properties of the gel phase by means of density, electrical conductivity and viscosity measurements. Also we include polarized microscopy images, showing the existence of a crystalline-like gel phase with the cations and anions (mainly the alkyl chain of this last ones) ordered in a fashion similar to a liquid crystal, which is induced by the presence of the water molecules. As was pointed out briefly in a previous paper, some of the mixtures of that system under goes a (liquid + gel) phase transition only in a quite narrow concentration interval: for ionic liquid molar fraction, x IL , from 0.09 to 0.5. Below x IL = 0.09 and above x IL = 0.5, the mixtures crystallize at low temperature becoming a hard solid crystal. Here we report the complete phase diagram of this binary system, as well as measurements of the temperature behavior of several physical properties around the (liquid + gel) and (liquid + crystal) transitions. Curiously enough, we did not detect any change in the temperature dependence of the measured magnitudes at the (liquid + gel) phase transition, but for viscosity, even in the case of the electrical conductivity
Politics of Inclusion and Empowerment

DEFF Research Database (Denmark)

Andersen, John; Siim, Birte

2004-01-01

identities. Politics of empowerment has to do with the agency and mobilisation dimension of social and political change. The title of the book "Politics of Inclusion and Empowerment" address the leitmotiv: namely to discuss plussumgame between politics of inclusion and politics of empowerment......The objective of the book is to analyse different politics of inclusion and empowerment and the different paradigms of inclusion/exclusion in order to underline the close link between politics of scoial equality and politics of recognition of ciultural difference. Politics of inclusion is thus...... theproductive/innovative linkage of politics of redistributuin and politics og resognition, whnich over a longer time span creates sustainable paths of democratic and social development, which increases the capacity to handle both conflicts about economic resources and life-chances and conflicts about...
Normalized inverse characterization of sound absorbing rigid porous media.

Science.gov (United States)

Zieliński, Tomasz G

2015-06-01

This paper presents a methodology for the inverse characterization of sound absorbing rigid porous media, based on standard measurements of the surface acoustic impedance of a porous sample. The model parameters need to be normalized to have a robust identification procedure which fits the model-predicted impedance curves with the measured ones. Such a normalization provides a substitute set of dimensionless (normalized) parameters unambiguously related to the original model parameters. Moreover, two scaling frequencies are introduced, however, they are not additional parameters and for different, yet reasonable, assumptions of their values, the identification procedure should eventually lead to the same solution. The proposed identification technique uses measured and computed impedance curves for a porous sample not only in the standard configuration, that is, set to the rigid termination piston in an impedance tube, but also with air gaps of known thicknesses between the sample and the piston. Therefore, all necessary analytical formulas for sound propagation in double-layered media are provided. The methodology is illustrated by one numerical test and by two examples based on the experimental measurements of the acoustic impedance and absorption of porous ceramic samples of different thicknesses and a sample of polyurethane foam.
Combined Measurement and QCD Analysis of the Inclusive ep Scattering Cross Sections at HERA

CERN Document Server

Aaron, F.D.; Abt, I.; Adamczyk, L.; Adamus, M.; Aldaya Martin, M.; Alexa, C.; Andreev, V.; Antonelli, S.; Antonioli, P.; Antonov, A.; Antunovic, B.; Arneodo, M.; Aushev, V.; Bachynska, O.; Backovic, S.; Baghdasaryan, A.; Bamberger, A.; Barakbaev, A.N.; Barbagli, G.; Bari, G.; Barreiro, F.; Barrelet, E.; Bartel, W.; Bartsch, D.; Basile, M.; Begzsuren, K.; Behnke, O.; Behr, J.; Behrens, U.; Bellagamba, L.; Belousov, A.; Bertolin, A.; Bhadra, S.; Bindi, M.; Bizot, J.C.; Blohm, C.; Bold, T.; Boos, E.G.; Borodin, M.; Borras, K.; Boscherini, D.; Bot, D.; Boudry, V.; Boutle, S.K.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Brock, I.; Brownson, E.; Brugnera, R.; Brummer, N.; Bruncko, D.; Bruni, A.; Bruni, G.; Brzozowska, B.; Bunyatyan, A.; Buschhorn, G.; Bussey, P.J.; Butterworth, J.M.; Bylsma, B.; Bystritskaya, L.; Caldwell, A.; Campbell, A.J.; Cantun Avila, K.B.; Capua, M.; Carlin, R.; Catterall, C.D.; Cerny, K.; Cerny, V.; Chekanov, S.; Chekelian, V.; Cholewa, A.; Chwastowski, J.; Ciborowski, J.; Ciesielski, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; Contreras, J.G.; Cooper-Sarkar, A.M.; Coppola, N.; Corradi, M.; Corriveau, F.; Costa, M.; Coughlan, J.A.; Cozzika, G.; Cvach, J.; D'Agostini, G.; Dainton, J.B.; Dal Corso, F.; Daum, K.; Deak, M.; de Favereau, J.; Delcourt, B.; del Peso, J.; Delvax, J.; Dementiev, R.K.; De Pasquale, S.; Derrick, M.; Devenish, R.C.E.; De Wolf, E.A.; Diaconu, C.; Dobur, D.; Dodonov, V.; Dolgoshein, B.A.; Dossanov, A.; Doyle, A.T.; Drugakov, V.; Dubak, A.; Durkin, L.S.; Dusini, S.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eisenberg, Y.; Eliseev, A.; Elsen, E.; Ermolov, P.F.; Eskreys, A.; Falkiewicz, A.; Fang, S.; Favart, L.; Fazio, S.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Ferrando, J.; Ferrero, M.I.; Figiel, J.; Fischer, D.J.; Fleischer, M.; Fomenko, A.; Forrest, M.; Foster, B.; Fourletov, S.; Gabathuler, E.; Galas, A.; Gallo, E.; Garfagnini, A.; Gayler, J.; Geiser, A.; Ghazaryan, S.; Gialas, I.; Gladilin, L.K.; Gladkov, D.; Glasman, C.; Glazov, A.; Glushkov, I.; Goerlich, L.; Gogitidze, N.; Golubkov, Yu.A.; Gottlicher, P.; Gouzevitch, M.; Grab, C.; Grabowska-Bold, I.; Grebenyuk, J.; Greenshaw, T.; Gregor, I.; Grell, B.R.; Grigorescu, G.; Grindhammer, G.; Grzelak, G.; Gwenlan, C.; Haas, T.; Habib, S.; Haidt, D.; Hain, W.; Hamatsu, R.; Hart, J.C.; Hartmann, H.; Hartner, G.; Helebrant, C.; Henderson, R.C.W.; Hennekemper, E.; Henschel, H.; Herbst, M.; Herrera, G.; Hildebrandt, M.; Hilger, E.; Hiller, K.H.; Hochman, D.; Hoffmann, D.; Holm, U.; Hori, R.; Horisberger, R.; Horton, K.; Hreus, T.; Huttmann, A.; Iacobucci, G.; Ibrahim, Z.A.; Iga, Y.; Ingbir, R.; Ishitsuka, M.; Jacquet, M.; Jakob, H.P.; Janssen, X.; Januschek, F.; Jimenez, M.; Jones, T.W.; Jonsson, L.; Jung, A.W.; Jung, H.; Jungst, M.; Kadenko, I.; Kahle, B.; Kamaluddin, B.; Kananov, S.; Kanno, T.; Kapichine, M.; Karshon, U.; Karstens, F.; Katkov, I.I.; Katzy, J.; Kaur, M.; Kaur, P.; Kenyon, I.R.; Keramidas, A.; Khein, L.A.; Kiesling, C.; Kim, J.Y.; Kisielewska, D.; Kitamura, S.; Klanner, R.; Klein, M.; Klein, U.; Kleinwort, C.; Kluge, T.; Knutsson, A.; Koffeman, E.; Kogler, R.; Kollar, D.; Kooijman, P.; Korol, Ie.; Korzhavina, I.A.; Kostka, P.; Kotanski, A.; Kotz, U.; Kowalski, H.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kulinski, P.; Kuprash, O.; Kutak, K.; Kuze, M.; Kuzmin, V.A.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Lee, A.; Lendermann, V.; Levchenko, B.B.; Levonian, S.; Levy, A.; Li, G.; Libov, V.; Limentani, S.; Ling, T.Y.; Lipka, K.; Liptaj, A.; Lisovyi, M.; List, B.; List, J.; Lobodzinska, E.; Lohmann, W.; Lohr, B.; Lohrmann, E.; Loizides, J.H.; Loktionova, N.; Long, K.R.; Longhin, A.; Lontkovskyi, D.; Lopez-Fernandez, R.; Lubimov, V.; Lukasik, J.; Lukina, O.Yu.; Luzniak, P.; Maeda, J.; Magill, S.; Makankine, A.; Makarenko, I.; Malinovski, E.; Malka, J.; Mankel, R.; Marage, P.; Margotti, A.; Marini, G.; Marti, Ll.; Martin, J.F.; Martyn, H.U.; Mastroberardino, A.; Matsumoto, T.; Mattingly, M.C.K.; Maxfield, S.J.; Mehta, A.; Melzer-Pellmann, I.A.; Meyer, A.B.; Meyer, H.; Meyer, H.; Meyer, J.; Miglioranzi, S.; Mikocki, S.; Milcewicz-Mika, I.; Mohamad Idris, F.; Monaco, V.; Montanari, A.; Moreau, F.; Morozov, A.; Morris, J.D.; Morris, J.V.; Mozer, M.U.; Mudrinic, M.; Muller, K.; Murin, P.; Musgrave, B.; Nagano, K.; Namsoo, T.; Nania, R.; Naumann, Th.; Newman, P.R.; Nicholass, D.; Niebuhr, C.; Nigro, A.; Nikiforov, A.; Nikitin, D.; Ning, Y.; Noor, U.; Notz, D.; Nowak, G.; Nowak, K.; Nowak, R.J.; Nuncio-Quiroz, A.E.; Oh, B.Y.; Okazaki, N.; Oliver, K.; Olkiewicz, K.; Olsson, J.E.; Onishchuk, Yu.; Osman, S.; Ota, O.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Papageorgiu, K.; Parenti, A.; Pascaud, C.; Patel, G.D.; Paul, E.; Pawlak, J.M.; Pawlik, B.; Pejchal, O.; Pelfer, P.G.; Pellegrino, A.; Perez, E.; Perlanski, W.; Perrey, H.; Petrukhin, A.; Picuric, I.; Piec, S.; Piotrzkowski, K.; Pitzl, D.; Placakyte, R.; Plucinski, P.; Pokorny, B.; Pokrovskiy, N.S.; Polifka, R.; Polini, A.; Povh, B.; Proskuryakov, A.S.; Przybycien, M.; Radescu, V.; Rahmat, A.J.; Raicevic, N.; Raspiareza, A.; Raval, A.; Ravdandorj, T.; Reeder, D.D.; Reimer, P.; Reisert, B.; Ren, Z.; Repond, J.; Ri, Y.D.; Rizvi, E.; Robertson, A.; Robmann, P.; Roland, B.; Roloff, P.; Ron, E.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Rubinsky, I.; Ruiz Tabasco, J.E.; Rusakov, S.; Ruspa, M.; Sacchi, R.; Salek, D.; Salii, A.; Samson, U.; Sankey, D.P.C.; Sartorelli, G.; Sauter, M.; Sauvan, E.; Savin, A.A.; Saxon, D.H.; Schioppa, M.; Schlenstedt, S.; Schleper, P.; Schmidke, W.B.; Schmitt, S.; Schneekloth, U.; Schoeffel, L.; Schonberg, V.; Schoning, A.; Schorner-Sadenius, T.; Schultz-Coulon, H.C.; Schwartz, J.; Sciulli, F.; Sefkow, F.; Shaw-West, R.N.; Shcheglova, L.M.; Shehzadi, R.; Shimizu, S.; Shtarkov, L.N.; Shushkevich, S.; Singh, I.; Skillicorn, I.O.; Sloan, T.; Slominski, W.; Smiljanic, I.; Smith, W.H.; Sola, V.; Solano, A.; Soloviev, Y.; Son, D.; Sopicki, P.; Sorokin, Iu.; Sosnovtsev, V.; South, D.; Spaskov, V.; Specka, A.; Spiridonov, A.; Stadie, H.; Stanco, L.; Staykova, Z.; Steder, M.; Stella, B.; Stern, A.; Stewart, T.P.; Stifutkin, A.; Stoicea, G.; Stopa, P.; Straumann, U.; Suchkov, S.; Sunar, D.; Susinno, G.; Suszycki, L.; Sykora, T.; Sztuk, J.; Szuba, D.; Szuba, J.; Tapper, A.D.; Tassi, E.; Tchoulakov, V.; Terron, J.; Theedt, T.; Thompson, G.; Thompson, P.D.; Tiecke, H.; Tokushuku, K.; Toll, T.; Tomasz, F.; Tomaszewska, J.; Tran, T.H.; Traynor, D.; Trinh, T.N.; Truol, P.; Tsakov, I.; Tseepeldorj, B.; Tsurugai, T.; Turcato, M.; Turnau, J.; Tymieniecka, T.; Urban, K.; Uribe-Estrada, C.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vazquez, M.; Verbytskyi, A.; Viazlo, V.; Vinokurova, S.; Vlasov, N.N.; Volchinski, V.; Volynets, O.; von den Driesch, M.; Walczak, R.; Wan Abdullah, W.A.T.; Wegener, D.; Whitmore, J.J.; Whyte, J.; Wiggers, L.; Wing, M.; Wissing, Ch.; Wlasenko, M.; Wolf, G.; Wolfe, H.; Wrona, K.; Wunsch, E.; Yagues-Molina, A.G.; Yamada, S.; Yamazaki, Y.; Yoshida, R.; Youngman, C.; Zacek, J.; Zalesak, J.; Zarnecki, A.F.; Zawiejski, L.; Zeniaev, O.; Zeuner, W.; Zhang, Z.; Zhautykov, B.O.; Zhokin, A.; Zhou, C.; Zichichi, A.; Zimmermann, T.; Zohrabyan, H.; Zolko, M.; Zomer, F.; Zotkin, D.S.

2010-01-01

A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised ep scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q^2, and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions HERAPDF1.0 with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result.
Determination of calibration equations by means of the generalized least squares method

International Nuclear Information System (INIS)

Zijp, W.L.

1984-12-01

For the determination of two-dimensional calibration curves (e.g. in tank calibration procedures) or of three dimensional calibration equations (e.g. for the calibration of NDA equipment for enrichment measurements) one performs measurements under well chosen conditions, where all observables of interest (inclusive the values of the standard material) are subject to measurement uncertainties. Moreover correlations in several measurements may occur. This document describes the mathematical-statistical approach to determine the values of the model parameters and their covariance matrix, which fit best to the mathematical model for the calibration equation. The formulae are based on the method of generalized least squares where the term generalized implies that non-linear equations in the unknown parameters and also covariance matrices of the measurement data of the calibration can be taken into account. In the general case an iteration procedure is required. No iteration is required when the model is linear in the parameters and the covariance matrices for the measurements of co-ordinates of the calibration points are proportional to each other
Positive semidefinite matrix completion, universal rigidity and the Strong Arnold Property

NARCIS (Netherlands)

Laurent, Monique; Varvitsiotis, A.

This paper addresses the following three topics: positive semidefinite (psd) matrix completions, universal rigidity of frameworks, and the Strong Arnold Property (SAP). We show some strong connections among these topics, using semidefinite programming as unifying theme. Our main contribution is a
Convergent Synthesis of Rigid Macrocycles Containing One and Two Tetrathiafulvalene Units

DEFF Research Database (Denmark)

Simonsen, Klaus B.; Thorup, Niels; Becher, Jan

1997-01-01

The synthesis of rigid tetrathiafulvalenophanes containing one or two tetrathiafulvalene units is presented, together with a stepwise convergent synthesis of macrocyclic bis-tetrathiafulvalenes via several open dimeric tetrathiafulvalenes. These systems were investigated by cyclic voltammetry...... and by X-ray crystallography....
A least-squares computational ''tool kit''

International Nuclear Information System (INIS)

Smith, D.L.

1993-04-01

The information assembled in this report is intended to offer a useful computational ''tool kit'' to individuals who are interested in a variety of practical applications for the least-squares method of parameter estimation. The fundamental principles of Bayesian analysis are outlined first and these are applied to development of both the simple and the generalized least-squares conditions. Formal solutions that satisfy these conditions are given subsequently. Their application to both linear and non-linear problems is described in detail. Numerical procedures required to implement these formal solutions are discussed and two utility computer algorithms are offered for this purpose (codes LSIOD and GLSIOD written in FORTRAN). Some simple, easily understood examples are included to illustrate the use of these algorithms. Several related topics are then addressed, including the generation of covariance matrices, the role of iteration in applications of least-squares procedures, the effects of numerical precision and an approach that can be pursued in developing data analysis packages that are directed toward special applications
Inclusive differentiated instruction

Directory of Open Access Journals (Sweden)

Jerković Ljiljana S.

2017-01-01

Full Text Available Inclusive differentiated instruction is a new model of didactic instruction, theoretically described and established in this paper for the first time, after being experimentally verified through teaching of the mother tongue (instruction in reading and literature. Inclusive individually planned instruction is based on a phenomenological and constructivist didactic instructional paradigm. This type of teaching is essentially developmental and person-oriented. The key stages of inclusive differentiated instruction of literature are: 1 recognition of individual students' potential and educational needs regarding reading and work on literary texts; 2 planning and preparation of inclusive individually planned instruction in reading and literature; 3 actual class teaching of lessons thus prepared; and 4 evaluation of the student achievement following inclusive differentiated instruction in reading and literature. A highly important element of the planning and preparation of inclusive differentiated instruction is the creation of student profiles and inclusive individualized syllabi. Individualized syllabi specify the following: 1. a brief student profile; 2. the student position on the continuum of the learning outcomes of instruction in the Serbian language; 3. reverse-engineered macro-plan stages of instruction in the Serbian language (3.1. identifying expected outcomes and fundamental qualities of learners' work, 3.2. defining acceptable proofs of their realisation, 3.3. planning learning and teaching experiences, and 3.4. providing material and technical requisites for teaching; 4 the contents and procedure of individualized lessons targeting the student; 5 a plan of syllabus implementation monitoring and evaluation. The continuum of the learning outcomes of inclusive differentiated instruction in literature exists at three main levels, A, B and C. The three levels are: A reading techniques and learning about the main literary theory concepts; B
Testing and Inclusive Schooling

DEFF Research Database (Denmark)

Morin, Anne; Hamre, Bjørn; Ydesen, Christian

Testing and Inclusive Schooling provides a comparative on seemingly incompatible global agendas and efforts to include all children in the general school system, Thus reducing exclusion. With an examination of the international testing culture and the politics of inclusion currently permeating...

Some links on this page may take you to non-federal websites. Their policies may differ from this site.