Relativistic collapse using Regge calculus: Pt. 1

International Nuclear Information System (INIS)

Dubal, M.R.; Leicester Univ.

1989-01-01

Regge calculus is used to simulate the dynamical collapse of model stars. In this paper we describe the general methodology of including a perfect fluid in dynamical Regge calculus spacetimes. The Regge-Einstein equations for spherical collapse are obtained and are then specialised to mimic a particular continuum gauge. The equivalent continuum problem is also set up. This is to be solved using standard numerical techniques (i.e. the method of finite difference). A subsequent paper will consider the solution of the equations presented here and will use the continuum problem for comparison purposes in order to check the Regge calculus results. (author)

Area Regge calculus and continuum limit

International Nuclear Information System (INIS)

Khatsymovsky, V.M.

2002-01-01

Encountered in the literature generalisations of general relativity to independent area variables are considered, the discrete (generalised Regge calculus) and continuum ones. The generalised Regge calculus can be either with purely area variables or, as we suggest, with area tensor-connection variables. Just for the latter, in particular, we prove that in analogy with corresponding statement in ordinary Regge calculus (by Feinberg, Friedberg, Lee and Ren), passing to the (appropriately defined) continuum limit yields the generalised continuum area tensor-connection general relativity

Regge calculus from discontinuous metrics

International Nuclear Information System (INIS)

Khatsymovsky, V.M.

2003-01-01

Regge calculus is considered as a particular case of the more general system where the linklengths of any two neighbouring 4-tetrahedra do not necessarily coincide on their common face. This system is treated as that one described by metric discontinuous on the faces. In the superspace of all discontinuous metrics the Regge calculus metrics form some hypersurface defined by continuity conditions. Quantum theory of the discontinuous metric system is assumed to be fixed somehow in the form of quantum measure on (the space of functionals on) the superspace. The problem of reducing this measure to the Regge hypersurface is addressed. The quantum Regge calculus measure is defined from a discontinuous metric measure by inserting the δ-function-like phase factor. The requirement that continuity conditions be imposed in a 'face-independent' way fixes this factor uniquely. The term 'face-independent' means that this factor depends only on the (hyper)plane spanned by the face, not on it's form and size. This requirement seems to be natural from the viewpoint of existence of the well-defined continuum limit maximally free of lattice artefacts

Classical models for Regge trajectories

International Nuclear Information System (INIS)

Biedenharn, L.C.; Van Dam, H.; Marmo, G.; Morandi, G.; Mukunda, N.; Samuel, J.; Sudarshan, E.C.G.

1987-01-01

Two classical models for particles with internal structure and which describe Regge trajectories are developed. The remarkable geometric and other properties of the two internal spaces are highlighted. It is shown that the conditions of positive time-like four-velocity and energy momentum for the classical system imply strong and physically reasonable conditions on the Regge mass-spin relationship

Three-plus-one formulation of Regge calculus

International Nuclear Information System (INIS)

Piran, T.; Williams, R.M.

1986-01-01

Following the work of Lund and Regge for homogeneous spaces, we construct the action for Regge calculus in its three-plus-one form for general space-times. This is achieved in two ways: a first-order formalism and a second-order formalism. We describe the Regge-calculus analogue of solving the initial-value equations using conformal transformations. The second-order formalism is used to study the time development of two simple model universes

Non-Regge and hyper-Regge effects in pion-nucleon charge exchange scattering at high energies

International Nuclear Information System (INIS)

Joynson, D.; Leader, E.; Nicolescu, B.; Paris-6 Univ., 75; Lopez, C.

1975-04-01

The experimental data on the charge exchange differential cross-section and on the difference on the π + p and π - p total cross-sections between 5GeV/c to 200GeV/c are shown to be incompatible with conventional Regge asymptotic behavior. It is shown that an additional term is required which grows in importance with energy. The precise form of the new term cannot be ascertained, but it is shown that it corresponds to a singularity at J=1 in the complex angular momentum plane. Amongst the possible types of additional term there are two which have been closely analysed: a non-Regge behavior, a hyper-Regge term which have allowed very striking predictions in particular for the charge exchange polarisation [fr

Regge calculus: applications to classical and quantum gravity

International Nuclear Information System (INIS)

Lewis, S.M.

1983-01-01

Regge calculus is a simplicial approximation to general relativity which preserves many topological and geometrical properties of the exact theory. After discussing the foundations of this technique and deriving some basic identities, specific solutions to Regge calculus are analyzed. In particular, the flat Friedmann-Robertson-Walker (FRW) model is shown. This particular model is used in the discussion of the initial value problem for Regge calculus. An Arnowitt-Deser-Misner type of 3 + 1 decomposition is possible only under very special circumstances; solutions with a non-spatially constant lapse can not generally be decomposed. The flat FRW model is also used to compute the accuracy of this approximation method developed by Regge. A three-dimensional toy model of quantum gravity is discussed that was originally formulated by Ponzano and Regge. A more thorough calculation is performed that takes into account additional terms. The renormalization properties of this model are shown. Finally, speculations are made on the interaction of the geometry, topology and quantum effects using Regge calculus, which, because of its simplicial nature, makes these effects more amenable to calculation and intuition

Regge cuts in γγ scattering

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Jackson, C.P.

1976-01-01

It is shown that the Pomeron-Pomeron cut in γγ scattering has natural C parity and conspires, in contrast to the Pomeron pole which is evasive, and has natural parity and C parity. The constraints this places upon the invariant amplitudes are analyzed

Quantum geometry in dynamical Regge calculus

International Nuclear Information System (INIS)

Hagura, Hiroyuki

2002-01-01

We study geometric properties of dynamical Regge calculus which is a hybridization of dynamical triangulation and quantum Regge calculus. Lattice diffeomorphisms are generated by certain elementary moves on a simplicial lattice in the hybrid model. At the semiclassical level, we discuss a possibility that the lattice diffeomorphisms give a simple explanation for the Bekenstein-Hawking entropy of a black hole. At the quantum level, numerical calculations of 3D pure gravity show that a fractal structure of the hybrid model is the same as that of dynamical triangulation in the strong-coupling phase. In the weak-coupling phase, on the other hand, space-time becomes a spiky configuration, which often occurs in quantum Regge calculus

The Bethe roots of Regge cuts in strongly coupled N=4 SYM theory

International Nuclear Information System (INIS)

Bartels, J.; Schomerus, V.; Sprenger, M.

2015-01-01

We describe a general algorithm for the computation of the remainder function for n-gluon scattering in multi-Regge kinematics for strongly coupled planar N=4 super Yang-Mills theory. This regime is accessible through the infrared physics of an auxiliary quantum integrable system describing strings in AdS 5 ×S 5 . Explicit formulas are presented for n=6 and n=7 external gluons. Our results are consistent with expectations from perturbative gauge theory. This paper comprises the technical details for the results announced in http://dx.doi.org/10.1007/JHEP10(2014)067.

Affine connection form of Regge calculus

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Khatsymovsky, V. M.

2016-12-01

Regge action is represented analogously to how the Palatini action for general relativity (GR) as some functional of the metric and a general connection as independent variables represents the Einstein-Hilbert action. The piecewise flat (or simplicial) spacetime of Regge calculus is equipped with some world coordinates and some piecewise affine metric which is completely defined by the set of edge lengths and the world coordinates of the vertices. The conjugate variables are the general nondegenerate matrices on the three-simplices which play the role of a general discrete connection. Our previous result on some representation of the Regge calculus action in terms of the local Euclidean (Minkowsky) frame vectors and orthogonal connection matrices as independent variables is somewhat modified for the considered case of the general linear group GL(4, R) of the connection matrices. As a result, we have some action invariant w.r.t. arbitrary change of coordinates of the vertices (and related GL(4, R) transformations in the four-simplices). Excluding GL(4, R) connection from this action via the equations of motion we have exactly the Regge action for the considered spacetime.

Construction of multi-Regge amplitudes by the Van Hove--Durand method

International Nuclear Information System (INIS)

Morrow, R.A.

1978-01-01

The Van Hove--Durand method of deriving Regge amplitudes by summing Feynman tree diagrams is extended to the multi-Regge domain. Using previously developed vertex functions for particles of arbitrary spins, single-, double-, and triple-Regge amplitudes incorporating signature are obtained. Criteria necessary to arrive at unique Regge-pole terms are found. It is also shown how external spins can be included

The perturbative Regge-calculus regime of loop quantum gravity

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Bianchi, Eugenio; Modesto, Leonardo

2008-01-01

The relation between loop quantum gravity and Regge calculus has been pointed out many times in the literature. In particular the large spin asymptotics of the Barrett-Crane vertex amplitude is known to be related to the Regge action. In this paper we study a semiclassical regime of loop quantum gravity and show that it admits an effective description in terms of perturbative area-Regge-calculus. The regime of interest is identified by a class of states given by superpositions of four-valent spin networks, peaked on large spins. As a probe of the dynamics in this regime, we compute explicitly two- and three-area correlation functions at the vertex amplitude level. We find that they match with the ones computed perturbatively in area-Regge-calculus with a single 4-simplex, once a specific perturbative action and measure have been chosen in the Regge-calculus path integral. Correlations of other geometric operators and the existence of this regime for other models for the dynamics are briefly discussed

Area Regge calculus and discontinuous metrics

International Nuclear Information System (INIS)

Wainwright, Chris; Williams, Ruth M

2004-01-01

Taking the triangle areas as independent variables in the theory of Regge calculus can lead to ambiguities in the edge lengths, which can be interpreted as discontinuities in the metric. We construct solutions to area Regge calculus using a triangulated lattice and find that on a spacelike or timelike hypersurface no such discontinuity can arise. On a null hypersurface however, we can have such a situation and the resulting metric can be interpreted as a so-called refractive wave

Discrete Quantum Gravity in the Regge Calculus Formalism

International Nuclear Information System (INIS)

Khatsymovsky, V.M.

2005-01-01

We discuss an approach to the discrete quantum gravity in the Regge calculus formalism that was developed in a number of our papers. The Regge calculus is general relativity for a subclass of general Riemannian manifolds called piecewise flat manifolds. The Regge calculus deals with a discrete set of variables, triangulation lengths, and contains continuous general relativity as a special limiting case where the lengths tend to zero. In our approach, the quantum length expectations are nonzero and of the order of the Plank scale, 10 -33 cm, implying a discrete spacetime structure on these scales

Discrete quantum gravitation in formalism of Regge calculus

International Nuclear Information System (INIS)

Khatsimovskij, V.M.

2005-01-01

One deals with approach to the discrete quantum gravitation in terms of the Regge calculus formalism. The Regge calculus represents the general relativity theory for the Riemann varieties - the piecewise planar varieties. The Regge calculus makes use of the discrete set of variables, triangulation lengths, and contains the continuous general relativity theory serving as a limiting special case when lengths tend to zero. In terms of our approach the quantum mean values of the mentioned lengths differ from zero and 10 -33 cm Planck length and it implies the discrete structure of space-time at the mentioned scales [ru

On the two-dimensional model of quantum Regge gravity

International Nuclear Information System (INIS)

Khatsimovskij, V.M.

1991-01-01

The Ashtekar-like variables are introduced in the Regge calculus. A simplified model of the resulting theory is quantized canonically. The consequences related to quantization of Regge areas are obtained. 10 refs

Length expectation values in quantum Regge calculus

International Nuclear Information System (INIS)

Khatsymovsky, V.M.

2004-01-01

Regge calculus configuration superspace can be embedded into a more general superspace where the length of any edge is defined ambiguously depending on the 4-tetrahedron containing the edge. Moreover, the latter superspace can be extended further so that even edge lengths in each the 4-tetrahedron are not defined, only area tensors of the 2-faces in it are. We make use of our previous result concerning quantization of the area tensor Regge calculus which gives finite expectation values for areas. Also our result is used showing that quantum measure in the Regge calculus can be uniquely fixed once we know quantum measure on (the space of the functionals on) the superspace of the theory with ambiguously defined edge lengths. We find that in this framework quantization of the usual Regge calculus is defined up to a parameter. The theory may possess nonzero (of the order of Planck scale) or zero length expectation values depending on whether this parameter is larger or smaller than a certain value. Vanishing length expectation values means that the theory is becoming continuous, here dynamically in the originally discrete framework

A continuous time formulation of the Regge calculus

International Nuclear Information System (INIS)

Brewin, Leo

1988-01-01

A complete continuous time formulation of the Regge calculus is presented by developing the associated continuous time Regge action. It is shown that the time constraint is, by way of the Bianchi identities conserved by the evolution equations. This analysis leads to an explicit first integral for each of the evolution equations. The dynamical equations of the theory are therefore reduced to a set of first-order differential equations. In this formalism the time constraints reduce to a simple sum of the integration constants. This result is unique to the Regge calculus-there does not appear to be a complete set of first integrals available for the vacuum Einstein equations. (author)

Towards understanding Regge trajectories in holographic QCD

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Cata, Oscar

2007-01-01

We reassess a work done by Migdal on the spectrum of low-energy vector mesons in QCD in the light of the anti-de Sitter (AdS)-QCD correspondence. Recently, a tantalizing parallelism was suggested between Migdal's work and a family of holographic duals of QCD. Despite the intriguing similarities, both approaches face a major drawback: the spectrum is in conflict with well-tested Regge scaling. However, it has recently been shown that holographic duals can be modified to accommodate Regge behavior. Therefore, it is interesting to understand whether Regge behavior can also be achieved in Migdal's approach. In this paper we investigate this issue. We find that Migdal's approach, which is based on a modified Pade approximant, is closely related to the issue of quark-hadron duality breakdown in QCD

Factorization of the six-particle multi-Regge amplitude

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Moen, I.O.

1975-01-01

It is shown that factorization of the multi-Regge contribution to the six-particle amplitude follows from the complex-helicity-plane structure, the Steinmann relations, and extended unitarity. The six-particle multi-Regge amplitude also satisfies some new discontinuity relations which are interpreted as resulting from the interplay of singularities required by the Gram-determinant constraint in four-dimensional space-time

Feynman path integral in area tensor Regge calculus and positivity

International Nuclear Information System (INIS)

Khatsymovsky, V.M.

2004-01-01

The versions of quantum measure in the area tensor Regge calculus constructed in the previous paper are studied on the simplest configurations of the system. These are found to be positively defined in the Euclidean case on physical surface corresponding to the ordinary Regge calculus (but not outside this surface), that is, adopt probabilistic interpretation. (Since Euclidean measure is defined via analytical continuation, positivity is not evident property.) An argument for positivity on physical surface on general configurations of area tensor Regge calculus is given

Multi-Regge limit of the n-gluon bubble ansatz

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Bartels, J. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Schomerus, V.; Sprenger, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2012-07-15

We investigate n-gluon scattering amplitudes in the multi-Regge region of N=4 supersymmetric Yang-Mills theory at strong coupling. Through a careful analysis of the thermodynamic bubble ansatz (TBA) for surfaces in AdS{sub 5} with n-g(lu)on boundary conditions we demonstrate that the multi-Regge limit probes the large volume regime of the TBA. In reaching the multi-Regge regime we encounter wall-crossing in the TBA for all n>6. Our results imply that there exists an auxiliary system of algebraic Bethe ansatz equations which encode valuable information on the analytical structure of amplitudes at strong coupling.

Initial data for time-symmetric gravitational radiation using Regge calculus

International Nuclear Information System (INIS)

Dubal, M.R.

1989-01-01

We apply Regge calculus to the construction of initial data for Brill waves: axisymmetric non-rotating vacuum solutions of Einstein's equation. The Regge calculus solutions are compared with those of the continuum theory, with encouraging results. (author)

Regge asymptotics of scattering with flavour exchange in QCD

International Nuclear Information System (INIS)

Kirschner, R.

1994-06-01

The contribution to the perturbative Regge asymptotics of the exchange of two reggeized fermions with opposite helicity is investigated. The methods of conformal symmetry known for the case of gluon exchange are extended to this case where double-logarithmic contributions dominate the asymptotics. The Regge trajectories at large momentum transfer are calculated. (orig.)

Dynamical Regge calculus as lattice gravity

International Nuclear Information System (INIS)

Hagura, Hiroyuki

2001-01-01

We propose a hybrid approach to lattice quantum gravity by combining simultaneously the dynamical triangulation with the Regge calculus, called the dynamical Regge calculus (DRC). In this approach lattice diffeomorphism is realized as an exact symmetry by some hybrid (k, l) moves on the simplicial lattice. Numerical study of 3D pure gravity shows that an entropy of the DRC is not exponetially bounded if we adopt the uniform measure Π i dl i . On the other hand, using the scale-invariant measure Π i dl i /l i , we can calculate observables and observe a large hysteresis between two phases that indicates the first-order nature of the phase transition

The quantization of Regge calculus

International Nuclear Information System (INIS)

Rocek, M.; Williams, R.M.; Cambridge Univ.

1984-01-01

We discuss the quantization of Regge's discrete description of Einstein's theory of gravitation. We show how the continuum theory emerges in the weak field long wavelength limit. We also discuss reparametrizations and conformal transformations. (orig.)

From lattice BF gauge theory to area-angle Regge calculus

International Nuclear Information System (INIS)

Bonzom, Valentin

2009-01-01

We consider Riemannian 4D BF lattice gauge theory, on a triangulation of spacetime. Introducing the simplicity constraints which turn BF theory into simplicial gravity, some geometric quantities of Regge calculus, areas, and 3D and 4D dihedral angles, are identified. The parallel transport conditions are taken care of to ensure a consistent gluing of simplices. We show that these gluing relations, together with the simplicity constraints, contain the constraints of area-angle Regge calculus in a simple way, via the group structure of the underlying BF gauge theory. This provides a precise road from constrained BF theory to area-angle Regge calculus. Doing so, a framework combining variables of lattice BF theory and Regge calculus is built. The action takes a form a la Regge and includes the contribution of the Immirzi parameter. In the absence of simplicity constraints, the standard spin foam model for BF theory is recovered. Insertions of local observables are investigated, leading to Casimir insertions for areas and reproducing for 3D angles known results obtained through angle operators on spin networks. The present formulation is argued to be suitable for deriving spin foam models from discrete path integrals and to unravel their geometric content.

Regge poles and alpha scattering

International Nuclear Information System (INIS)

Ceuleneer, R.

1974-01-01

The direct Regge pole model as a means of describing resonances in elastic particle scattering has been used for the analysis of the so-called ''anormalous large angle scattering'' of alpha particles by spinless nuclei. (Z.M.)

Semiclassical regime of Regge calculus and spin foams

International Nuclear Information System (INIS)

Bianchi, Eugenio; Satz, Alejandro

2009-01-01

Recent attempts to recover the graviton propagator from spin foam models involve the use of a boundary quantum state peaked on a classical geometry. The question arises whether beyond the case of a single simplex this suffices for peaking the interior geometry in a semiclassical configuration. In this paper we explore this issue in the context of quantum Regge calculus with a general triangulation. Via a stationary phase approximation, we show that the boundary state succeeds in peaking the interior in the appropriate configuration, and that boundary correlations can be computed order by order in an asymptotic expansion. Further, we show that if we replace at each simplex the exponential of the Regge action by its cosine-as expected from the semiclassical limit of spin foam models-then the contribution from the sign-reversed terms is suppressed in the semiclassical regime and the results match those of conventional Regge calculus

Regge calculus and observations. II. Further applications

International Nuclear Information System (INIS)

Williams, R.M.; Ellis, G.F.R.

1983-03-01

The method, developed in an earlier paper, for tracing geodesics of particles and light rays through Regge calculus space-times, is applied to a number of problems in the Schwarschild geometry. It is possible to obtain accurate predictions of light-bending by taking sufficiently small Regge blocks. Calculations of perihelion precession, Thomas precession and the distortion of a ball of fluid moving on a geodesic can also show good agreement with the analytic solution. However difficulties arise in obtaining accurate predictions for general orbits in these space-times. Applications to other problems in general relativity are discussed briefly. (author)

Regge calculus and observations. II. Further applications.

Science.gov (United States)

Williams, Ruth M.; Ellis, G. F. R.

1984-11-01

The method, developed in an earlier paper, for tracing geodesies of particles and light rays through Regge calculus space-times, is applied to a number of problems in the Schwarzschild geometry. It is possible to obtain accurate predictions of light bending by taking sufficiently small Regge blocks. Calculations of perihelion precession, Thomas precession, and the distortion of a ball of fluid moving on a geodesic can also show good agreement with the analytic solution. However difficulties arise in obtaining accurate predictions for general orbits in these space-times. Applications to other problems in general relativity are discussed briefly.

High energy production of gluons in a quasi-multi-Regge kinematics

International Nuclear Information System (INIS)

Fadin, V.S.; Lipatov, L.N.

1989-01-01

Inelastic gluon-gluon scattering amplitudes in the Born approximation for the quasi-multi-Regge kinematics are calculated, starting with the Veneziano-type expression for the inelastic amplitude of the gluon-tachyon scattering with its subsequent simplification in the region of large energies and the Regge slope α'→0. Results obtained allow one to determine the high order corrections to the gluon Regge trajectory, the reggeon-particle vertices and to the integral kernel of the Bethe-Salpeter equation for the vacuum t-channel partial waves. 10 refs.; 7 figs

Regge trajectories for heavy quarkonia from the quadratic form of the spinless Salpeter-type equation

Science.gov (United States)

Chen, Jiao-Kai

2018-03-01

In this paper, we present one new form of the Regge trajectories for heavy quarkonia which is obtained from the quadratic form of the spinless Salpeter-type equation (QSSE) by employing the Bohr-Sommerfeld quantization approach. The obtained Regge trajectories take the parameterized form M^2={β }({c_l}l+{π }n_r+c_0)^{2/3}+c_1, which are different from the present Regge trajectories. Then we apply the obtained Regge trajectories to fit the spectra of charmonia and bottomonia. The fitted Regge trajectories are in good agreement with the experimental data and the theoretical predictions.

Radial and Regge excitations in unified, grand unified and subconstituent models

International Nuclear Information System (INIS)

Schnitzer, H.J.

1981-01-01

Necessary group theoretic conditions for all elementary gauge bosons and fermions of an arbitrary renormalizable gauge theory to lie on Regge trajectories are reviewed. It is then argued that in properly unified gauge theories all particles of a given spin lie on Regge trajectories. This then implies that a properly unified gauge theory has no local U(1) factor groups, and no massive fermion singlets. A consideration of the general pattern of Regge and radial recurrences to be expected in quantum field theories suggests that the presence or absence of spin 3/2 quarks and/or leptons in the TeV region will provide crucial clues to enable one to distinguish between various classes of unified, grand unified, and subconstituent models. The correct interpretation of such excited fermions will require correlation with the higgs boson mass and possible radial and Regge excitations of the weak vector bosons. (orig.)

Regge-plus-resonance predictions for charged-kaon photoproduction from the deuteron

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Van Cauteren T.

2010-04-01

Full Text Available We present a Regge-inspired effective-Lagrangian framework for charged-kaon photoproduction from the deuteron. Quasi-free kaon production is investigated using the Regge-plus-resonance elementary operator within the non-relativistic plane-wave impulse approximation. The Regge-plus-resonance model was developed to describe photoinduced and electroinduced kaon production off protons and can be extended to strangeness production off neutrons. The non-resonant contributions to the amplitude are modelled in terms of K+ (494 and K*+ (892 Regge-trajectory exchange in the t-channel. This amplitude is supplemented with a selection of s-channel resonance-exchange diagrams. We investigate several sources of theoretical uncertainties on the semi-inclusive charged-kaon production cross section. The experimental error bars on the photocoupling helicity amplitudes turn out to put severe limits on the predictive power when considering quasi-free kaon production on a bound neutron.

Wilson loop OPE, analytic continuation and multi-Regge limit

International Nuclear Information System (INIS)

Hatsuda, Yasuyuki

2014-05-01

We explore a direct connection between the collinear limit and the multi-Regge limit for scattering amplitudes in the N=4 super Yang-Mills theory. Starting with the collinear expansion for the six-gluon amplitude in the Euclidean kinematic region, we perform an analytic continuation term by term to the so-called Mandelstam region. We find that the result coincides with the collinear expansion of the analytically continued amplitude. We then take the multi-Regge limit, and conjecture that the final result precisely reproduces the one from the BFKL approach. Combining this procedure with the OPE for null polygonal Wilson loops, we explicitly compute the leading contribution in the ''collinear-Regge'' limit up to five loops. Our results agree with all the known results up to four loops. At five-loop, our results up to the next-to-next-to-leading logarithmic approximation (NNLLA) also reproduce the known results, and for the N 3 LLA and the N 4 LLA give non-trivial predictions. We further present an all-loop prediction for the imaginary part of the next-to-double-leading logarithmic approximation. Our procedure has a possibility of an interpolation from weak to strong coupling in the multi-Regge limit with the help of the OPE.

Quantum Regge calculus in the Lorentzian domain and its Hamiltonian formulation

International Nuclear Information System (INIS)

Williams, R.M.; Cambridge Univ.

1986-01-01

A formalism is set up for quantum Regge calculus in the Lorentzian domain, calculating the inverse propagator in the free field case. The variables in the Arnowitt-Deser-Misner [1962, Gravitation, an Introduction to Current Research, ed. L. Witten (New York: Wiley) p 227] 3 + 1 formulation of general relativity are related to the Regge calculus variables. (author)

Analytic multi-Regge theory and the pomeron in QCD. 1

International Nuclear Information System (INIS)

White, A.R.

1991-01-01

This paper reports on the formalism of analytic multi-Regge theory developed as a basis for the study of abstract critical and super-critical pomeron high-energy behavior and for related studies of the Regge behavior of spontaneously broken gauge theories and the pomeron in QCD. Asymptotic domains of analyticity for multiparticle amplitudes are shown to follow from properties of field theory and S-matrix theory. General asymptotic dispersion relations are then derived for such amplitudes in which the spectral components are described by the graphical formalism of hexagraphs. Further consequences are distinct Sommerfeld-Watson representations for each hexagraph spectral component, together with a complete set of angular momentum plane unitarity equations which control the form of all multi-Regge amplitudes. Because of this constraint of reggeon unitarity the critical pomeron solution of the reggeon field theory gives the only known non-trivial unitary high-energy S-matrix. By exploiting the full structure of multi-Regge amplitudes as the pomeron becomes super-critical, one can study the simultaneous modification of hadrons and the pomeron. The result is a completely consistent description of the super-critical pomeron appearing in hadron scattering. Reggeon unitarity is satisfied in the super-critical phase by the appearance of a massive gluon (Reggeized vector particle) coupling pair-wise to the pomeron

Independent variables in 3 + 1 Regge calculus

International Nuclear Information System (INIS)

Tuckey, P.A.

1989-01-01

The space of metrics in 3+1 Regge calculus is discussed, and the problems of counting its dimensions, and of finding independent variables to parametrise the space, are addressed. The most general natural class of metrics is considered first, and bounds on its dimension are obtained, although no good parametrisations are found. The relationship between these metrics and those used in canonical Regge calculus is shown, and this leads to an interesting result via the Bianchi identities. A restricted class of metrics is then considered and independent variables, which parametrise these metrics and which may be computationally convenient, are given. The dimension of this space of metrics gives an improved lower bound for the dimension of the general space. (author)

Semiclassical approach to Regge poles trajectories calculations for nonsingular potentials: Thomas-Fermi type

International Nuclear Information System (INIS)

Belov, S M; Avdonina, N B; Felfli, Z; Marletta, M; Msezane, A Z; Naboko, S N

2004-01-01

A simple semiclassical approach, based on the investigation of anti-Stokes line topology, is presented for calculating Regge poles for nonsingular (Thomas-Fermi type) potentials, namely potentials with singularities at the origin weaker than order -2. The anti-Stokes lines for Thomas-Fermi potentials have a more complicated structure than those of singular potentials and require careful application of complex analysis. The explicit solution of the Bohr-Sommerfeld quantization condition is used to obtain approximate Regge poles. We introduce and employ three hypotheses to obtain several terms of the Regge pole approximation

Cut cancellation in the planar integral equation for the Reggeon

International Nuclear Information System (INIS)

Bishari, M.; Veneziano, G.

1975-01-01

Planar unitarity for the Reggeon, analyticity and the multi-Regge assumption with cluster production lead to integral equations of the Chew-Goldberger-Low type with separable self-consistent kernel. Contrary to common prejudice, the authors show the existence of solutions exhibiting moving poles and exact, non-perturbative cancellation of the cut. Previously studied consistency conditions are rederived. (Auth.)

Approximation of hadron interactions by Regge diagrams with multipomeron exchange

International Nuclear Information System (INIS)

Barashenkov, V.S.

1988-01-01

A good agreement of hadron diffraction interaction total cross section and their elastic scattering at small angles calculated by summarizing Regge multipomeron exchange diagrams with experiment mentioned by a number of authors results from the fitting of a great variety of the parameters contained in the formulas. The agreement of the other hadron characteristcs with experiment is worse. Distribution of hadron interactions over the number of fragmenting quark-gluon strings calculated by utilizing Regge diagrams is discussed

Conditional probabilities in Ponzano-Regge minisuperspace

International Nuclear Information System (INIS)

Petryk, Roman; Schleich, Kristin

2003-01-01

We examine the Hartle-Hawking no-boundary initial state for the Ponzano-Regge formulation of gravity in three dimensions. We consider the behavior of conditional probabilities and expectation values for geometrical quantities in this initial state for a simple minisuperspace model consisting of a two-parameter set of anisotropic geometries on a 2-sphere boundary. We find dependence on the cutoff used in the construction of Ponzano-Regge amplitudes for expectation values of edge lengths. However, these expectation values are cutoff independent when computed in certain, but not all, conditional probability distributions. Conditions that yield cutoff independent expectation values are those that constrain the boundary geometry to a finite range of edge lengths. We argue that such conditions have a correspondence to fixing a range of local time, as classically associated with the area of a surface for spatially closed cosmologies. Thus these results may hint at how classical spacetime emerges from quantum amplitudes

Bounds for OPE coefficients on the Regge trajectory

Science.gov (United States)

Costa, Miguel S.; Hansen, Tobias; Penedones, João

2017-10-01

We consider the Regge limit of the CFT correlation functions and , where J is a vector current, T is the stress tensor and O is some scalar operator. These correlation functions are related by a type of Fourier transform to the AdS phase shift of the dual 2-to-2 scattering process. AdS unitarity was conjectured some time ago to be positivity of the imaginary part of this bulk phase shift. This condition was recently proved using purely CFT arguments. For large N CFTs we further expand on these ideas, by considering the phase shift in the Regge limit, which is dominated by the leading Regge pole with spin j( ν), where ν is a spectral parameter. We compute the phase shift as a function of the bulk impact parameter, and then use AdS unitarity to impose bounds on the analytically continued OPE coefficients {C}_JJ}j(ν )} and C TTj(ν) that describe the coupling to the leading Regge trajectory of the current J and stress tensor T. AdS unitarity implies that the OPE coefficients associated to non-minimal couplings of the bulk theory vanish at the intercept value ν = 0, for any CFT. Focusing on the case of large gap theories, this result can be used to show that the physical OPE coefficients {C}_{JJT and C TTT , associated to non-minimal bulk couplings, scale with the gap Δ g as Δ g - 2 or Δ g - 4 . Also, looking directly at the unitarity condition imposed at the OPE coefficients {C_JJT and C TTT results precisely in the known conformal collider bounds, giving a new CFT derivation of these bounds. We finish with remarks on finite N theories and show directly in the CFT that the spin function j( ν) is convex, extending this property to the continuation to complex spin.

Mean multiplicity in the Regge models with rising cross sections

International Nuclear Information System (INIS)

Chikovani, Z.E.; Kobylisky, N.A.; Martynov, E.S.

1979-01-01

Behaviour of the mean multiplicity and the total cross section σsub(t) of hadron-hadron interactions is considered in the framework of the Regge models at high energies. Generating function was plotted for models of dipole and froissaron, and the mean multiplicity and multiplicity moments were calculated. It is shown that approximately ln 2 S (energy square) in the dipole model, which is in good agreement with the experiment. It is also found that in various Regge models approximately σsub(t)lnS

The contracted Bianchi identities in Regge calculus

International Nuclear Information System (INIS)

Williams, Ruth M

2012-01-01

In this note, we show explicitly how the linearized contracted Bianchi identities at a vertex in four-dimensional Regge calculus are related to a sum of the equations of motion for all the edges meeting at that vertex. (note)

Note on 3-dimensional Regge calculus

International Nuclear Information System (INIS)

Soda, Jiro

1991-01-01

We shall study 3-dimensional Regge calculus with concentrating the role of the Bianchi identity. As a result, the number of the physical variables is determined to be 12g - 12(g > 1). The reason why Rocek and Williams derived the exact result of Deser, Jackiw and 'tHooft is clarified. (author)

Regge-pole description of potential scattering by means of the phase-integral method

International Nuclear Information System (INIS)

Amaha, A.

1992-01-01

The application of Regge-pole theory to different atomic and molecular scattering has shown to have promising interpretational power in the differential cross sections. Differential cross sections can be analysed in terms of interference between the 'background' amplitude and a few Regge-pole positions of the scattering matrix (S matrix) representing surface waves around the interaction region. By the analytic continuation of the radial Schroedinger differential equation into the complex plane of angular momentum one can determine the analytic properties of the S matrix which contains the physical information in the scattering processes. For interaction potentials fulfilling certain properties, the study of the S matrix leads to the study of the F matrix introduced by Froeman and Froeman for the treatment of connection problems for phase-integral solutions of the differential equation. In this thesis the quantum mechanical scattering problem is analysed in the framework of Regge-pole theory with the use of the complex-angular-momentum formalism. To determine the S matrix, the relevant F matrix elements which give the stokes constants are derived and their properties are studied. The poles of the S matrix for particular complex values of the angular momentum quantum number are the Regge-poles. Using the Regge-pole positions and residues together with the background integral, the differential cross sections are calculated and compared with corresponding partial-wave representations

A new approach to the Regge calculus

International Nuclear Information System (INIS)

Porter, J.

1987-01-01

The paper develops a new approach to Regge calculus, a numerical technique used for the calculation of general relativistic spacetimes. The method is developed in an original '3 + 1' form in such a way that it can be applied to inhomogeneous spacetimes. (author)

Double Regge pole exchange model analysis of a 7 Gev/c. pi. /sup -/p experiment. [Absolute cross sections, one-particle exchange, diffraction scattering

Energy Technology Data Exchange (ETDEWEB)

Chao, A C.L.

1973-01-01

A double Regge Pole Exchange Model is used to analyze Quasi-Three-Body final states selected from a 7 GeV/c - /sup -/p experiment. Three sets of data are analyzed namely: I ..pi../sup -/p ..-->.. p..pi../sup +/..pi../sup -/..pi../sup -/; II ..pi../sup -/p ..-->.. p..pi../sup +/..pi../sup -/..pi../sup -/..pi../sup 0/; III ..pi../sup -/p ..-->.. ..pi../sup +/..pi../sup +/..pi../sup -/..pi../sup -/n. The final states, selected from data sets I, II and III are (rho/sup 0/..pi../sup -/p, f/sup 0/..pi../sup -/p, ..pi../sup -/..pi../sup -/..delta../sup + +/), (rho/sup 0/..pi../sup -/..delta../sup +/, rho/sup -/..pi..-..delta../sup + +/, ..omega pi../sup -/p) and (rho/sup 0/..pi../sup -/..delta../sup +/), respectively. It is found that these channels after appropriate kinematic cuts can be well described by exchanging two Regge Trajectories. Predictions for the absolute cross-sections were also obtained by taking limits of one particle exchange and a diffraction scattering approximation. (auth)

Effective action for the Regge processes in gravity

Energy Technology Data Exchange (ETDEWEB)

Lipatov, L.N. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg (Russian Federation); Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2011-05-15

It is shown, that the effective action for the reggeized graviton interactions can be formulated in terms of the reggeon fields A{sup ++} and A{sup --} and the metric tensor g{sub {mu}}{sub {nu}} in such a way, that it is local in the rapidity space and has the property of general covariance. The corresponding effective currents j{sup -} and j{sup +} satisfy the Hamilton-Jacobi equation for a massless particle moving in the gravitational field. These currents are calculated explicitly for the shock wave-like fields and a variation principle for them is formulated. As an application, we reproduce the effective lagrangian for the multi-regge processes in gravity together with the graviton Regge trajectory in the leading logarithmic approximation with taking into account supersymmetric contributions. (orig.)

MHV amplitudes for 3→3 gluon scattering in Regge limit

International Nuclear Information System (INIS)

Bartels, J.; Prygarin, A.

2010-12-01

We calculate corrections to the BDS formula for the six-particle planar MHV amplitude for the gluon transition 3 → 3 in the multi-Regge kinematics for the physical region, in which the Regge pole ansatz is not valid. The remainder function at two loops is obtained by an analytic continuation of the expression derived by Goncharov, Spradlin, Vergu and Volovich to the kinematic region described by the Mandelstam singularity exchange in the crossing channel. It contains both the imaginary and real contributions being in agreement with the BFKL predictions. The real part of the three loop expression is found from a dispersion-like all-loop formula for the remainder function in the multi-Regge kinematics derived by one of the authors. We also make a prediction for the all-loop real part of the remainder function multiplied by the BDS phase, which can be accessible through calculations in the regime of the strong coupling constant. (orig.)

MHV amplitudes for 3{yields}3 gluon scattering in Regge limit

Energy Technology Data Exchange (ETDEWEB)

Bartels, J.; Prygarin, A. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Lipatov, L.N. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; St. Petersburg Nuclear Physics Institute (Russian Federation)

2010-12-15

We calculate corrections to the BDS formula for the six-particle planar MHV amplitude for the gluon transition 3 {yields} 3 in the multi-Regge kinematics for the physical region, in which the Regge pole ansatz is not valid. The remainder function at two loops is obtained by an analytic continuation of the expression derived by Goncharov, Spradlin, Vergu and Volovich to the kinematic region described by the Mandelstam singularity exchange in the crossing channel. It contains both the imaginary and real contributions being in agreement with the BFKL predictions. The real part of the three loop expression is found from a dispersion-like all-loop formula for the remainder function in the multi-Regge kinematics derived by one of the authors. We also make a prediction for the all-loop real part of the remainder function multiplied by the BDS phase, which can be accessible through calculations in the regime of the strong coupling constant. (orig.)

The fundamental theorem of linearised Regge calculus

International Nuclear Information System (INIS)

Barrett, J.W.

1987-01-01

In linearised Regge calculus in a topologically trivial region, the space of linearised deviations of the edge lengths from a flat configuration, divided by the subspace of deformations due to translations of the vertices, is equivalent to the space of the linearised curvatures which satisfy the Bianchi identities. (orig.)

A new approach to the Regge calculus

International Nuclear Information System (INIS)

Porter, J.

1987-01-01

In paper 1 an original '3 + 1' form of Regge calculus was developed. In the current paper the method is tested by application to spherically symmetric vacuum space-times. Three different time slicing conditions are used and, where appropriate, the results are compared with the analytic solution with encouraging results. (author)

Mandelstam cuts and light-like Wilson loops in N=4 SUSY

Energy Technology Data Exchange (ETDEWEB)

Lipatov, L.N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; St. Petersburg Inst. of Nuclear Physics, Gatchina (Russian Federation); Prygarin, A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2010-08-15

We perform an analytic continuation of the two-loop remainder function for the six-point planar MHV amplitude in N=4 SUSY, found by Goncharov, Spradlin, Vergu and Volovich from the light-like Wilson loop representation. The remainder function is continued into a physical region, where all but two energy invariants are negative. It turns out to be pure imaginary in the multi-Regge kinematics, which is in an agreement with the predictions based on the Steinmann relations for the Regge poles and Mandelstam cut contributions. The leading term reproduces correctly the expression calculated by one of the authors in the BFKL approach, while the subleading term presents a result, that was not yet found with the use of the unitarity techniques. This supports the applicability of the Wilson loop approach to the planar MHV amplitudes in N=4 SUSY. (orig.)

Mandelstam cuts and light-like Wilson loops in N=4 SUSY

International Nuclear Information System (INIS)

Lipatov, L.N.; Prygarin, A.

2010-08-01

We perform an analytic continuation of the two-loop remainder function for the six-point planar MHV amplitude in N=4 SUSY, found by Goncharov, Spradlin, Vergu and Volovich from the light-like Wilson loop representation. The remainder function is continued into a physical region, where all but two energy invariants are negative. It turns out to be pure imaginary in the multi-Regge kinematics, which is in an agreement with the predictions based on the Steinmann relations for the Regge poles and Mandelstam cut contributions. The leading term reproduces correctly the expression calculated by one of the authors in the BFKL approach, while the subleading term presents a result, that was not yet found with the use of the unitarity techniques. This supports the applicability of the Wilson loop approach to the planar MHV amplitudes in N=4 SUSY. (orig.)

Time-evolution problem in Regge calculus

International Nuclear Information System (INIS)

Sorkin, R.

1975-01-01

The simplectic approximation to Einstein's equations (''Regge calculus'') is derived by considering the net to be actually a (singular) Riemannian manifold. Specific nets for open and closed spaces are introduced in terms of which one can formulate the general time-evolution problem, which thereby reduces to the repeated solution of finite sets of coupled nonlinear (algebraic) equations. The initial-value problem is also formulated in simplectic terms

Modified Regge calculus as an explanation of dark energy

International Nuclear Information System (INIS)

Stuckey, W M; McDevitt, T J; Silberstein, M

2012-01-01

Using the Regge calculus, we construct a Regge differential equation for the time evolution of the scale factor a(t) in the Einstein-de Sitter cosmology model (EdS). We propose two modifications to the Regge calculus approach: (1) we allow the graphical links on spatial hypersurfaces to be large, as in direct particle interaction when the interacting particles reside in different galaxies, and (2) we assume that luminosity distance D L is related to graphical proper distance D p by the equation D L = (1+z)√D p ·D p , where the inner product can differ from its usual trivial form. The modified Regge calculus model (MORC), EdS and ΛCDM are compared using the data from the Union2 Compilation, i.e. distance moduli and redshifts for type Ia supernovae. We find that a best fit line through logD L versus logz gives a correlation of 0.9955 and a sum of squares error (SSE) of 1.95. By comparison, the best fit ΛCDM gives SSE = 1.79 using H o = 69.2 kms -1 Mpc, Ω M = 0.29 and Ω Λ = 0.71. The best fit EdS gives SSE = 2.68 using H o 60.9 km s -1 Mpc. The best-fit MORC gives SSE = 1.77 and H o = 73.9 km s -1 Mpc using R = A -1 = 8.38 Gcy and m = 1.71 x 10 52 kg, where R is the current graphical proper distance between nodes, A -1 is the scaling factor from our non-trivial inner product, and m is the nodal mass. Thus, the MORC improves the EdS as well as ΛCDM in accounting for distance moduli and redshifts for type Ia supernovae without having to invoke accelerated expansion, i.e. there is no dark energy and the universe is always decelerating. (paper)

Assuming Regge trajectories in holographic QCD: from OPE to Chiral Perturbation Theory

CERN Document Server

Cappiello, Luigi; Greynat, David

2015-01-01

The Soft Wall model in holographic QCD has Regge trajectories but wrong operator product expansion (OPE) for the two-point vectorial QCD Green function. We correct analytically this problem and describe the axial sector and chiral symmetry breaking. The low energy chiral parameters, $F_{\\pi}$ and $L_{10}$ , are well described analytically by the model in terms of Regge spacing and QCD condensates. The model nicely supports and extends previous theoretical analyses advocating Digamma function to study QCD two-point functions in different momentum regions.

Regge expansion of a casual spectral function in electroproduction

International Nuclear Information System (INIS)

Ahmed, M.A.; Taha, M.O.

1975-01-01

The conjecture that a term in the Regge espansion of the Deser-Gilbert-Sudarshan spectral function in electroproduction may identically vanish is investigated. It is shown that this conjecture does not appear to be in agreement with experiment

The (ℎ/2π)-expansion for Regge-trajectories. 2. Relativistic equations

International Nuclear Information System (INIS)

Stepanov, S.S.; Tutik, R.S.

1992-01-01

The (h/2π)-expansion method, proposed earlier for deriving Regge trajectories for bound states of central potentials in the Schroedinger equation framework, is extended to the Klein-Gordon and Dirac equations with potentials having vector and scalar components. The simple recursion formulae, with the same form both for the parent and daughter Regge trajectories, are obtained. They provide, in principle, the calculation of the (h/2π)-expansion terms up to an arbitrary order. As an illustration, a superposition of the vector and scalar Coulomb potentials, and the funnel-shaped potential are treated with the technique developed. 20 refs.; 3 figs.; 1 table. (author)

On the combinatorial foundations of Regge-calculus

International Nuclear Information System (INIS)

Budach, L.

1989-01-01

Lipschitz-Killing curvatures of piecewise flat spaces are combinatorial analogues of Lipschitz-Killing curvatures of Riemannian manifolds. In the following paper rigorous combinatorial representations and proofs of all basic results for Lipschitz-Killing curvatures not using analytic arguments are given. The principal tools for an elementary representation of Regge calculus can be developed by means of basic properties of dihedral angles. (author)

Gluonic Regge singularities and anomalous dimensions in QCD

International Nuclear Information System (INIS)

Jaroszewicz, T.

1982-01-01

The Regge calculus results on the perturbative Pomeron are applied to deep inelastic scattering. Explicit expressions are given for the anomalous dimensions γsub(GGG)sup(n) and γsub(GF)sup(n) at n approx.= 1 to the lowest order in α and all orders in α/(n-1). (author)

The role of leading twist operators in the Regge and Lorentzian OPE limits

Energy Technology Data Exchange (ETDEWEB)

Costa, Miguel S. [Centro de Física do Porto, Departamento de Física e Astronomia,Faculdade de Ciências da Universidade do Porto,Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Drummond, James [CERN,Geneva 23 (Switzerland); School of Physics and Astronomy, University of Southampton,Highfield, Southampton, SO17 1BJ (United Kingdom); LAPTH, CNRS et Université de Savoie,F-74941 Annecy-le-Vieux Cedex (France); Gonçalves, Vasco; Penedones, João [Centro de Física do Porto, Departamento de Física e Astronomia,Faculdade de Ciências da Universidade do Porto,Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

2014-04-14

We study two kinematical limits, the Regge limit and the Lorentzian OPE limit, of the four-point function of the stress-tensor multiplet in Super Yang-Mills at weak coupling. We explain how both kinematical limits are controlled by the leading twist operators. We use the known expression of the four-point function up to three loops, to extract the pomeron residue at next-to-leading order. Using this data and the known form of pomeron spin up to next-to-leading order, we predict the behaviour of the four-point function in the Regge limit at higher loops. Specifically, we determine the leading log behaviour at any loop order and the next-to-leading log at four loops. Finally, we check the consistency of our results with conformal Regge theory. This leads us to predict the behaviour around J=1 of the OPE coefficient of the spin J leading twist operator in the OPE of two chiral primary operators.

Solving QCD via multi-Regge theory

International Nuclear Information System (INIS)

White, A. R.

1998-01-01

To solve QCD at high-energy the authors must simultaneously find the hadronic states and the exchanged pomeron (IP) giving UNITARY scattering amplitudes. Experimentally, the IP ∼ a Regge pole at small Q 2 and a single gluon at larger Q 2 . (F 2 D -H1, dijets-ZEUS). In the solution which the author describes, these non-perturbative properties of the IP are directly related to the non-perturbative confinement and chiral symmetry breaking properties of hadrons

Collinear and Regge behavior of 2{yields}4 MHV amplitude in N=4 super Yang-Mills theory

Energy Technology Data Exchange (ETDEWEB)

Bartels, J.; Prygarin, A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Lipatov, L.N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; St. Petersburg Nuclear Physics Institute (Russian Federation)

2011-04-15

We investigate the collinear and Regge behavior of the 2{yields}4 MHV amplitude in N=4 super Yang-Mills theory in the BFKL approach. The expression for the remainder function in the collinear kinematics proposed by Alday, Gaiotto, Maldacena, Sever and Vieira is analytically continued to the Mandelstam region. The result of the continuation in the Regge kinematics shows an agreement with the BFKL approach up to to five-loop level. We present the Regge theory interpretation of the obtained results and discuss some issues related to a possible nonmultiplicative renormalization of the remainder function in the collinear limit. (orig.)

The application of Regge calculus to quantum gravity and quantum field theory in a curved background

International Nuclear Information System (INIS)

Warner, N.P.

1982-01-01

The application of Regge calculus to quantum gravity and quantum field theory in a curved background is discussed. A discrete form of exterior differential calculus is developed, and this is used to obtain Laplacians for p-forms on the Regge manifold. To assess the accuracy of these approximations, the eigenvalues of the discrete Laplacians were calculated for the regular tesselations of S 2 and S 3 . The results indicate that the methods obtained in this paper may be used in curved space-times with an accuracy comparing with that obtained in lattice gauge theories on a flat background. It also becomes evident that Regge calculus provides particularly suitable lattices for Monte-Carlo techniques. (author)

Pomeron models and exchange degeneracy of the Regge trajectories

International Nuclear Information System (INIS)

Kontros, J.; Kontros, K.; Lengyel, A.

2000-01-01

Two models for the Pomeron, supplemented by exchange-degenerate sub-leading Regge trajectories, are fitted to the forward scattering data for a number of reactions. By considering new Pomeron models, we extend the recent results of the COMPAS group, being consistent with our predecessors

The convergence of lattice solutions of linearised Regge calculus

International Nuclear Information System (INIS)

Barrett, J.W.; Williams, R.M.

1988-01-01

Sequences of configurations of linearised Regge calculus converging to plane wave solutions are constructed to illustrate an earlier result on convergence. It is shown that, for these examples, the convergence criterion filters out the solutions which do not satisfy Einstein's equations from those which do. (author)

Ponzano-Regge model revisited: I. Gauge fixing, observables and interacting spinning particles

International Nuclear Information System (INIS)

Freidel, Laurent; Louapre, David

2004-01-01

We show how to properly gauge fix all the symmetries of the Ponzano-Regge model for 3D quantum gravity. This amounts to doing explicit finite computations for transition amplitudes. We give the construction of the transition amplitudes in the presence of interacting quantum spinning particles. We introduce a notion of operators whose expectation value gives rise to either gauge fixing, introduction of time, or insertion of particles, according to the choice. We give the link between the spin foam quantization and the Hamiltonian quantization. We finally show the link between the Ponzano-Regge model and the quantization of Chern-Simons theory based on the double quantum group of SU(2)

Path integral in area tensor Regge calculus and complex connections

International Nuclear Information System (INIS)

Khatsymovsky, V.M.

2006-01-01

Euclidean quantum measure in Regge calculus with independent area tensors is considered using example of the Regge manifold of a simple structure. We go over to integrations along certain contours in the hyperplane of complex connection variables. Discrete connection and curvature on classical solutions of the equations of motion are not, strictly speaking, genuine connection and curvature, but more general quantities and, therefore, these do not appear as arguments of a function to be averaged, but are the integration (dummy) variables. We argue that upon integrating out the latter the resulting measure can be well-defined on physical hypersurface (for the area tensors corresponding to certain edge vectors, i.e. to certain metric) as positive and having exponential cutoff at large areas on condition that we confine ourselves to configurations which do not pass through degenerate metrics

The geometry of classical Regge calculus

International Nuclear Information System (INIS)

Barrett, J.W.

1987-01-01

Standard notions of Riemannian geometry are applied to the case of piecewise-flat manifolds. Particular care is taken to explain how one may define some particular vectors and tensors in an invariant way at points of a conical singularity. The geometry surrounding the equations of motion and the energy-momentum of the piecewise-flat manifold is developed in detail. The resolution theorem is presented, which states that on certain resolution hypersurfaces there is a clear connection between the energy-momentum of the piecewise-flat manifold and the Regge equations of motion. (author)

A numerical study of the Regge calculus and smooth lattice methods on a Kasner cosmology

International Nuclear Information System (INIS)

Brewin, Leo

2015-01-01

Two lattice based methods for numerical relativity, the Regge calculus and the smooth lattice relativity, will be compared with respect to accuracy and computational speed in a full 3+1 evolution of initial data representing a standard Kasner cosmology. It will be shown that both methods provide convergent approximations to the exact Kasner cosmology. It will also be shown that the Regge calculus is of the order of 110 times slower than the smooth lattice method. (paper)

On the continuum limit of curvature squared actions in the Regge calculus

International Nuclear Information System (INIS)

Eliezer, D.

1989-01-01

We evaluate the continuum limit of a family of curvature squared actions for the Regge calculus proposed by Hamber and Williams. The answers depend on how the continuum limit is defined. When the link lengths are defined as the distance in an embedding space between the endpoints of the link, we find that no member of this family approaches the continuum limit correctly. Defining the link lengths as the length of a geodesic between the endpoints of the link, we find that a unique member is selected, and we prove for the general two dimensional compact manifold that this Regge calculus action converges to ∫R 2 √d d 2 x. (orig.)

Simple Regge pole model for Compton scattering of protons

International Nuclear Information System (INIS)

Saleem, M.; Fazal-e-Aleem

1978-01-01

It is shown that by a phenomenological choice of the residue functions, the differential cross section for ν p → ν p, including the very recent measurements up to - t=4.3 (GeV/c) 2 , can be explained at all measured energies greater than 2 GeV with simple Regge pole model

Calculation of relativistic model stars using Regge calculus

International Nuclear Information System (INIS)

Porter, J.

1987-01-01

A new approach to the Regge calculus, developed in a previous paper, is used in conjunction with the velocity potential version of relativistic fluid dynamics due to Schutz [1970, Phys. Rev., D, 2, 2762] to calculate relativistic model stars. The results are compared with those obtained when the Tolman-Oppenheimer-Volkov equations are solved by other numerical methods. The agreement is found to be excellent. (author)

Models of Regge behaviour in an asymptotically free theory

International Nuclear Information System (INIS)

Polkinghorne, J.C.

1976-01-01

Two simple Feynman integral models are presented which reproduce the features expected to be of physical importance in the Regge behaviour of asymptotically free theories. Analysis confirms the result, expected on general grounds, that phi 3 in six dimensions has an essential singularity at l=-1. The extension to gauge theories is discussed. (Auth.)

Regge parametrization of angular distributions for heavy-ion transfer reactions

International Nuclear Information System (INIS)

Carlson, B.V.; McVoy, K.W.

1977-01-01

A two-pole one-zero Regge parametrization of the l-window for transfer reactions is employed in conjunction with a chi-squared search program to obtain high-quality fits to a wide variety of transfer data. The data employed include both direct and multi-step transfers. (Auth.)

Extraction of Structure Function and Gluon Distribution Function at Low-x from Cross Section Derivative by Regge Behavior

International Nuclear Information System (INIS)

Boroun, G.R.

2005-01-01

An approximation method based on Regge behavior is presented. This new method relates the reduced cross section derivative and the structure function Regge behavior at low x. With the use of this approximation method, the C and λ parameters are calculated from the HERA reduced cross section data taken at low-x. Also, we calculate the structure functions F 2 (x,Q 2 ) even for low-x values, which have not been investigated. To test the validity of calculated structure functions, we find the gluon distribution function in the Leading order approximation based on Regge behaviour of structure function and compare to the NLO QCD fit to H1 data and NLO parton distribution function.

Quark contribution to the gluon Regge trajectory at NLO from the high energy effective action

International Nuclear Information System (INIS)

Chachamis, G.; Hentschinski, M.; Madrigal Martínez, J.D.; Sabio Vera, A.

2012-01-01

The two loop (NLO) diagrams with quark content contributing to the gluon Regge trajectory are computed within the framework of Lipatov's effective action for QCD, using the regularization procedure for longitudinal divergencies recently proposed by two of us in (M. Hentschinski and A. Sabio Vera, 2011). Perfect agreement with previous results in the literature is found, providing a robust check of the regularization prescription and showing that the high energy effective action is a very useful computational tool in the quasi-multi-Regge limit.

A 3 + 1 Regge calculus model of the Taub universe

International Nuclear Information System (INIS)

Tuckey, P.A.

1988-01-01

The Piran and Williams [1986 Phys. Rev. D 33,1622] second-order formulation of 3 + 1 Regge calculus is used to calculate the evolution of a model of the Taub universe. The model displays qualitatively the correct behaviour, thereby giving some verification of the 3 + 1 formulation. (author)

Dimensional reduction and BRST approach to the description of a Regge trajectory

International Nuclear Information System (INIS)

Pashnev, A.I.; Tsulaya, M.M.

1997-01-01

The local free field theory for Regge trajectory is described in the framework of the BRST-quantization method. The corresponding BRST-charge is constructed with the help of the method of dimensional reduction

On d=2 Regge calculus without triangulation

International Nuclear Information System (INIS)

Foerster, D.

1987-01-01

The supersymmetric version of a previously developed Regge calculus for d=2 euclidean gravity is given. In the context of string theory, a continuum theory is likely to exist for D<2 external space-time dimensions, just like in the bosonic case and essentially in agreement with the weak coupling regime D≤1 found by Gervais and Neveu for Liouville theory and its supersymmetric extension. The techniques developed here are intended to be of use, eventually, in lowering the critical dimensions of string theories. (orig.)

Infra-red divergences and Regge behaviour in QCD

International Nuclear Information System (INIS)

Jaroszewicz, T.

1980-01-01

We analyze high energy behaviour of multi-gluon exchange amplitudes in the leading-lns approximation in perturbation theory. Working in the Coulomb gauge and employing Ward identities we derive an integral equation for the n-gluon system in the exchange channel. We find that the Regge behaviour is associated with exponentiation of leading infrared divergences, and the position of the j-plane singularities is determined by the colour quantum numbers of the exchanged system. (author)

Multi-Regge amplitudes for bremsstrahlung in e+e- backward scattering

International Nuclear Information System (INIS)

Ermolaev, B.I.; Lipatov, L.N.

1988-01-01

Using the method of factorization, equations are obtained for the inelastic on-shell amplitudes describing the asymptotic behavior of e + e - backward scattering with emission of bremsstrahlung photons in the doubly logarithmic approximation. Explicit expressions are found for these amplitudes in the case in which the photons are emitted with multi-Regge kinematics

Regge behaviour of structure functions and evolution of gluon structure function upto next-to-leading order at low-x

International Nuclear Information System (INIS)

Jamil, U.; Sarma, J.K.

2011-01-01

Evolution of gluon structure function from Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations upto next-to-leading order at low-x is presented assuming the Regge behaviour of structure functions. We compare our results of gluon structure function with GRV 98 global parameterization and show the compatibility of Regge behaviour of structure functions with PQCD. (author)

Gravity-matter entanglement in Regge quantum gravity

International Nuclear Information System (INIS)

Paunković, Nikola; Vojinović, Marko

2016-01-01

We argue that Hartle-Hawking states in the Regge quantum gravity model generically contain non-trivial entanglement between gravity and matter fields. Generic impossibility to talk about “matter in a point of space” is in line with the idea of an emergent spacetime, and as such could be taken as a possible candidate for a criterion for a plausible theory of quantum gravity. Finally, this new entanglement could be seen as an additional “effective interaction”, which could possibly bring corrections to the weak equivalence principle. (paper)

On the definition of the partition function in quantum Regge calculus

International Nuclear Information System (INIS)

Nishimura, Jun

1995-01-01

We argue that the definition of the partition function used recently to demonstrate the failure of Regge calculus is wrong. In fact, in the one-dimensional case, we show that there is a more natural definition, with which one can reproduce the correct results. (author)

Regge in the sky: Origin of the cosmic rotation

International Nuclear Information System (INIS)

Muradian, R.

1994-06-01

Observed universal spin and mass relationship for a wide range of astronomical objects are described by two extended Regge trajectories: disc-trajectory for stars and planets, and ball-trajectory for galaxies and their clusters. The cosmic Chew-Frautschi plot is presented and two fundamental points are revealed on it: Eddington and Chandrasekhar points with coordinates expressed via combinations of the fundamental constants. (author). 17 refs, 3 figs

The non-ordinary Regge behavior of the K{sup *}{sub 0}(800) or κ-meson versus the ordinary K{sup *}{sub 0}(1430)

Energy Technology Data Exchange (ETDEWEB)

Pelaez, J.R.; Rodas, A. [Universidad Complutense de Madrid, Departamento de Fisica Teorica II and UPARCOS, Madrid (Spain)

2017-06-15

The Regge trajectory of an elastic resonance can be calculated from dispersion theory, instead of fitted phenomenologically, using only its pole parameters as input. This also provides a correct treatment of resonance widths in Regge trajectories, essential for very wide resonances. In this work we first calculate the K{sup *}{sub 0}(1430) Regge trajectory, finding the ordinary almost real and linear behavior, typical of q anti q resonances. In contrast, for the K{sup *}{sub 0}(800) meson, the resulting Regge trajectory is non-linear and has a much smaller slope than ordinary resonances, being remarkably similar to that of the f{sub 0}(500) or σ meson. The slope of these unusual Regge trajectories seems to scale with the meson masses rather than with scales typical of quark degrees of freedom. We also calculate the range of the interaction responsible for the formation of these resonances. Our results strongly support a non-ordinary, predominantly meson-meson-like, interpretation for the lightest strange and non-strange resonances. (orig.)

Patterns of High energy Massive String Scatterings in the Regge Regime

International Nuclear Information System (INIS)

Lee Jen Chi

2009-01-01

We calculate high energy massive string scattering amplitudes of open bosonic string in the Regge regime (RR). We found that the number of high energy amplitudes for each fixed mass level in the RR is much more numerous than that of Gross regime (GR) calculated previously. Moreover, we discover that the leading order amplitudes in the RR can be expressed in terms of the Kummer function of the second kind. In particular, based on a summation algorithm for Stirling number identities developed recently, we discover that the ratios calculated previously among scattering amplitudes in the GR can be extracted from this Kummer function in the RR. We conjecture and give evidences that the existence of these GR ratios in the RR persists to sub-leading orders in the Regge expansion of all string scattering amplitudes. Finally, we demonstrate the universal power-law behavior for all massive string scattering amplitudes in the RR. (author)

On the Regge-Wheeler Tortoise and the Kruskal-Szekeres Coordinates

Directory of Open Access Journals (Sweden)

Crothers S. J.

2006-07-01

Full Text Available The Regge-Wheeler tortoise “coordinate” and the the Kruskal-Szekeres “extension” are built upon a latent set of invalid assumptions. Consequently, they have led to fallacious conclusions about Einstein’s gravitational field. The persistent unjustified claims made for the aforesaid alleged coordinates are not sustained by mathematical rigour. They must therefore be discarded.

Regge-like initial input and evolution of non-singlet structure ...

Indian Academy of Sciences (India)

Regge-like initial input and evolution of non-singlet structure functions from DGLAP equation up to next-next-to-leading order at low x and low Q. 2. NAYAN MANI NATH1,2,∗, MRINAL KUMAR DAS1 and JAYANTA KUMAR SARMA1. 1Department of Physics, Tezpur University, Tezpur 784 028, India. 2Department of Physics ...

Regge limit of R-current correlators in AdS supergravity

International Nuclear Information System (INIS)

Bartels, J.; Kotanski, J.; Mischler, A.M.; Schomerus, V.

2009-08-01

Four-point functions of R-currents are discussed within Anti-de Sitter supergravity. In particular, we compute Witten diagrams with graviton and gauge boson exchange in the high energy Regge limit. Assuming validity of the AdS/CFT correspondence, our results apply to R-current four-point functions of N=4 super Yang-Mills theory at strong coupling. (orig.)

Unitarization of pomeron and Regge phenomenology of deep inelastic scattering.

Energy Technology Data Exchange (ETDEWEB)

Martynov, E S

1994-12-31

Using conventional Regge approach we consider unitarization of supercritical pomeron in DIS and then describe the total photon-proton cross-section and the proton structure functions in the region W{sup 2} = Q{sup 2}(1/x-1) + m{sup 2} {>=} 9 GeV{sup 2}, including the small-x data from HERA. (author). 15 refs., 1 tab., 15 figs.

Regge behaviour and Bjorken scaling for deep-inelastic lepton-hadron scattering process

International Nuclear Information System (INIS)

Tran Huu Phat

1976-01-01

Within the framework of the Jost-Lehmann-Dyson (JLD) representation and the renormalization-group (RG) equation, it is shown that either the RG technique is not applicable to deep-inelastic phenomena or Regge behaviour and Bjorken scaling for structure functions do not coexist. (author)

Four point function of R-currents in N=4 SYM in the Regge limit at weak coupling

Energy Technology Data Exchange (ETDEWEB)

Bartels, J.; Mischler, A.M.; Salvadore, M. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2008-04-15

We compute, in N = 4 super Yang-Mills, the four point correlation function of R-currents in the Regge limit in the leading logarithmic approximation at weak coupling. Such a correlator is the closest analog to photon-photon scattering within QCD, and there is a well defined procedure to perform the analogous computation at strong coupling via AdS/CFT. The main result of this paper is, on the gauge theory side, the proof of Regge factorization and the explicit computation of the R-current impact factors. (orig.)

Analysis of pp scattering at the CERN ISR energies in the multiple Regge pole model

International Nuclear Information System (INIS)

Bugrij, A.I.; Kobylinsky, N.A.

1976-01-01

The simple Regge model is suggested for describing data on proton-proton elastic scattering at high energies. The simplest variant of the Regge model can be formulated as a sum of two pomerons, the first being a moving double pole and the second - a fixed simple pole. Comparison with known data is given. The model gives an infinite rise of the total cross section of pp-scattering. The differential cross section changes slowly with energy. The models of two pomerons reproduce many features of the geometric scaling, in particular, the shift of the dip and rise of scattering total cross section at the second maximum. The considered model is rather simple and is well consistent with experiment

Structure and properties of Regge-Mueller diagrams for the case of Froissart saturation

International Nuclear Information System (INIS)

Kobylinsky, N.A.; Kosenko, A.I.; Martynov, E.S.

1976-01-01

A model leading to the Froissart saturation in various diffractive and nondiffractive production processes is elaborated. The restrictions on a structure of Regge-Mueller diagrams are obtained in the model. A comparison is made of the pomeron, dipole and froissaron models

Intercepts and residues of Regge poles in a stochastic-field multiparticle theory

International Nuclear Information System (INIS)

Arnold, R.C.

1976-01-01

A dynamical theory of multiparticle amplitudes, based on a functional integral representation embodying collective long-range correlations, is applied to the calculation of Regge intercepts and residues. Poles arising in conventional multiperipheral models will characteristically be modified in three ways: promotion, renormalization, and a proliferation of dynamical secondary trajectories, reminiscent of dual models

Quantum Regge Calculus of Einstein-Cartan theory

International Nuclear Information System (INIS)

Xue Shesheng

2009-01-01

We study the Quantum Regge Calculus of Einstein-Cartan theory to describe quantum dynamics of Euclidean space-time discretized as a 4-simplices complex. Tetrad field e μ (x) and spin-connection field ω μ (x) are assigned to each 1-simplex. Applying the torsion-free Cartan structure equation to each 2-simplex, we discuss parallel transports and construct a diffeomorphism and local gauge-invariant Einstein-Cartan action. Invariant holonomies of tetrad and spin-connection fields along large loops are also given. Quantization is defined by a bounded partition function with the measure of SO(4)-group valued ω μ (x) fields and Dirac-matrix valued e μ (x) fields over 4-simplices complex.

Regge poles and Mandelstam representation in potential scattering; Poles de regge et representation de Mandelstam en theorie du potentiel

Energy Technology Data Exchange (ETDEWEB)

Bessis, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-03-01

We deal with the scattering of two spinless particles interacting by a superposition of Yukawa potentials. We first obtain an upper bound for the scattering amplitude for simultaneous complex values of energy and angular momentum. We then show that the Regge poles remain confined in small domains of the complex angular momentum plane, we study the variation of these domains when the energy (complex) varies. These first results allow us to deduce an upper bound for the double spectral function, this upper bound is used to rigorously show that the Schroedinger equation implies the Mandelstam representation for the type of potentials we deal with. Finally, the problem of subtractions is entirely solved, showing that the Mellin transform of the double spectral function can be analytically continued into the different simple spectral functions. (author) [French] On traite de la diffusion de deux particules sans spin interagissant par l'intermediaire d'une superposition de potentiels de Yukawa. Nous obtenons tout d'abord une majorante pour l'amplitude de diffusion pour des valeurs simultanement complexes de l'energie et du moment cinetique. On montre alors que les Poles de Regge restent confines dans des domaines restreints du plan complexe du moment cinetique, domaines dont nous etudions la variation pour des valeurs complexes de l'energie. Ces premiers resultats nous permettent alors de deduire une majorante pour la fonction spectrale double, majorante qui est utilisee pour demontrer rigoureusement que l'equation de Schroedinger implique la representation de Mandelstam pour la classe des potentiels envisages. Enfin le probleme des soustractions est entierement resolu, en montrant que la transformee de Mellin de la fonction spectrale double se prolonge analytiquement dans les diverses fonctions spectrales simples. (auteur)

Energy and Regge residues in quantum-mechanical ''QCD'' sum rules

International Nuclear Information System (INIS)

Durand, B.; Durand, L.

1986-01-01

It was shown recently by Fishbane, Kaus, and Gasiorowicz that the residues at the poles of quantum-mechanical two-point functions for arbitrary angular momenta l have an incorrect l dependence when calculated by the sum-rule method used for the analogous problem in QCD. Knowledge of the residues is of interest since they are directly related to particle couplings and decay widths. We develop reliable expressions for the energy and Regge residues using semiclassical methods

Hexagon OPE resummation and multi-Regge kinematics

Energy Technology Data Exchange (ETDEWEB)

Drummond, J.M. [School of Physics & Astronomy, University of Southampton,Highfield, Southampton, SO17 1BJ (United Kingdom); Theory Division, Physics Department, CERN,CH-1211 Geneva 23 (Switzerland); LAPTh, CNRS, Université de Savoie,9 Chemin de Bellevue, F-74941 Annecy-le-Vieux Cedex (France); Papathanasiou, G. [LAPTh, CNRS, Université de Savoie,9 Chemin de Bellevue, F-74941 Annecy-le-Vieux Cedex (France)

2016-02-29

We analyse the OPE contribution of gluon bound states in the double scaling limit of the hexagonal Wilson loop in planar N=4 super Yang-Mills theory. We provide a systematic procedure for perturbatively resumming the contributions from single-particle bound states of gluons and expressing the result order by order in terms of two-variable polylogarithms. We also analyse certain contributions from two-particle gluon bound states and find that, after analytic continuation to the 2→4 Mandelstam region and passing to multi-Regge kinematics (MRK), only the single-particle gluon bound states contribute. From this double-scaled version of MRK we are able to reconstruct the full hexagon remainder function in MRK up to five loops by invoking single-valuedness of the results.

Baryon Regge trajectories from the area-law of Wilson loop

International Nuclear Information System (INIS)

Simonov, Yu.A.

1989-01-01

In the proper-time path integral representation of the three-quark Green function, baryon masses are calculated for large angular momenta L. Dynamics is given by vacuum background fields in the Wilson loop. Assuming an area law for large Wilson loops one obtains linear baryon Regge trajectories with the same slope as for mesons. For large L the baryon has an asymmetric structure of the quark-diquark type. Dynamic masses of the quark and diquark are generated, which grow with L. 8 refs

Wilson loop, Regge trajectory and hadron masses in a Yang-Mills theory from semiclassical strings

International Nuclear Information System (INIS)

Bigazzi, F.; Cotrone, A.L.; Martucci, L.; Pando Zayas, L.A.

2004-07-01

We compute the one-loop string corrections to the Wilson loop, glueball Regge trajectory and stringy hadron masses in the Witten model of non supersymmetric, large-N Yang-Mills theory. The classical string configurations corresponding to the above field theory objects are respectively: open straight strings, folded closed spinning strings, and strings orbiting in the internal part of the supergravity background. For the rectangular Wilson loop we show that besides the standard Luscher term, string corrections provide a rescaling of the field theory string tension. The one-loop corrections to the linear glueball Regge trajectories render them nonlinear with a positive intercept, as in the experimental soft Pomeron trajectory. Strings orbiting in the internal space predict a spectrum of hadronic-like states charged under global flavor symmetries which falls in the same universality class of other confining models. (author)

String theory of the Regge intercept.

Science.gov (United States)

Hellerman, S; Swanson, I

2015-03-20

Using the Polchinski-Strominger effective string theory in the covariant gauge, we compute the mass of a rotating string in D dimensions with large angular momenta J, in one or two planes, in fixed ratio, up to and including first subleading order in the large J expansion. This constitutes a first-principles calculation of the value for the order-J(0) contribution to the mass squared of a meson on the leading Regge trajectory in planar QCD with bosonic quarks. For open strings with Neumann boundary conditions, and for closed strings in D≥5, the order-J(0) term in the mass squared is exactly calculated by the semiclassical approximation. This term in the expansion is universal and independent of the details of the theory, assuming only D-dimensional Poincaré invariance and the absence of other infinite-range excitations on the string world volume, beyond the Nambu-Goldstone bosons.

Open string Regge trajectory and its field theory limit

International Nuclear Information System (INIS)

Rojas, Francisco; Thorn, Charles B.

2011-01-01

We study the properties of the leading Regge trajectory in open string theory including the open string planar one-loop corrections. With SU(N) Chan-Paton factors, the sum over planar open string multiloop diagrams describes the 't Hooft limit N→∞ with Ng s 2 fixed. Our motivation is to improve the understanding of open string theory at finite α ' as a model of gauge field theories. SU(N) gauge theories in D space-time dimensions are described by requiring open strings to end on a stack of N Dp-branes of space-time dimension D=p+1. The large N leading trajectory α(t)=1+α ' t+Σ(t) can be extracted, through order g 2 , from the s→-∞ limit, at fixed t, of the four open string tree and planar loop diagrams. We analyze the t→0 behavior with the result that Σ(t)∼-Cg 2 (-α ' t) (D-4)/2 /(D-4). This result precisely tracks the 1-loop Reggeized gluon of gauge theory in D>4 space-time dimensions. In particular, for D→4 it reproduces the known infrared divergences of gauge theory in 4 dimensions with a Regge trajectory behaving as -ln(-α ' t). We also study Σ(t) in the limit t→-∞ and show that, when D ' t/(ln(-α ' t)) γ , where γ>0 depends on D and the number of massless scalars. Thus, as long as 4 ' t arbitrarily large. Finally we present the results of numerical calculations of Σ(t) for all negative t.

Unified treatment: analyticity, Regge trajectories, Veneziano amplitude, fundamental regions and Moebius transformations

International Nuclear Information System (INIS)

Choudhary, A.R.

2003-01-01

In this paper we present a unified treatment that combines the analyticity properties of the scattering amplitudes, the threshold and asymptotic behaviors, the invariance group of Moebius transformations, the automorphic functions defined over this invariance group, the fundamental region in (Poincare) geometry, and the generators of the invariance group as they relate to the fundamental region. Using these concepts and techniques, we provide a theoretical basis for Veneziano type amplitudes with the ghost elimination condition built in, related the Regge trajectory functions to the generators of the invariance group, constrained the values of the Regge trajectories to take only inverse integer values at the threshold, used the threshold behavior in the forward direction to deduce the Pomeranchuk trajectory as well as other relations. The enabling tool for this unified treatment came from the multi-sheet conformal mapping techniques that map the physical sheet to a fundamental region which in turn defines a Riemann surface on which a global uniformization variable for the scattering amplitude is calculated via an automorphic function, which in turn can be constructed as a quotient of two automorphic forms of the same dimension. (orig.)

Multi-Regge kinematics and the moduli space of Riemann spheres with marked points

Energy Technology Data Exchange (ETDEWEB)

Duca, Vittorio Del [Institute for Theoretical Physics, ETH Zürich,Hönggerberg, 8093 Zürich (Switzerland); Druc, Stefan; Drummond, James [School of Physics & Astronomy, University of Southampton,Highfield, Southampton, SO17 1BJ (United Kingdom); Duhr, Claude [Theoretical Physics Department, CERN,Route de Meyrin, CH-1211 Geneva 23 (Switzerland); Center for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain,Chemin du Cyclotron 2, 1348 Louvain-La-Neuve (Belgium); Dulat, Falko [SLAC National Accelerator Laboratory, Stanford University,Stanford, CA 94309 (United States); Marzucca, Robin [Center for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain,Chemin du Cyclotron 2, 1348 Louvain-La-Neuve (Belgium); Papathanasiou, Georgios [SLAC National Accelerator Laboratory, Stanford University,Stanford, CA 94309 (United States); Verbeek, Bram [Center for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain,Chemin du Cyclotron 2, 1348 Louvain-La-Neuve (Belgium)

2016-08-25

We show that scattering amplitudes in planar N=4 Super Yang-Mills in multi-Regge kinematics can naturally be expressed in terms of single-valued iterated integrals on the moduli space of Riemann spheres with marked points. As a consequence, scattering amplitudes in this limit can be expressed as convolutions that can easily be computed using Stokes’ theorem. We apply this framework to MHV amplitudes to leading-logarithmic accuracy (LLA), and we prove that at L loops all MHV amplitudes are determined by amplitudes with up to L+4 external legs. We also investigate non-MHV amplitudes, and we show that they can be obtained by convoluting the MHV results with a certain helicity flip kernel. We classify all leading singularities that appear at LLA in the Regge limit for arbitrary helicity configurations and any number of external legs. Finally, we use our new framework to obtain explicit analytic results at LLA for all MHV amplitudes up to five loops and all non-MHV amplitudes with up to eight external legs and four loops.

Forward pion-nucleon charge exchange reaction and Regge constraints

International Nuclear Information System (INIS)

Huang Fei; Sibirtsev, A.; Krewald, S.; Hanhart, C.; Haidenbauer, J.; Meibner, U.-G.

2009-01-01

We present our recent study of pion-nucleon charge exchange amplitudes above 2 GeV. We analyze the forward pion-nucleon charge exchange reaction data in a Regge model and compare the resulting amplitudes with those from the Karlsruhe-Helsinki and George-Washington-University partial-wave analyses. We explore possible high-energy constraints for theoretical baryon resonance analyses in the energy region above 2 GeV. Our results show that for the pion-nucleon charge exchange reaction, the appropriate energy region for matching meson-nucleon dynamics to diffractive scattering should be around 3 GeV for the helicity flip amplitude. (authors)

Fast algorithms for computing defects and their derivatives in the Regge calculus

International Nuclear Information System (INIS)

Brewin, Leo

2011-01-01

Any practical attempt to solve the Regge equations, these being a large system of non-linear algebraic equations, will almost certainly employ a Newton-Raphson-like scheme. In such cases, it is essential that efficient algorithms be used when computing the defect angles and their derivatives with respect to the leg lengths. The purpose of this paper is to present details of such an algorithm.

First Regge parameterisation of polarized DIS cross section

International Nuclear Information System (INIS)

Thomas, E.; Bianchi, N.

2000-01-01

The first Regge description of the virtual photon absorption cross section difference Δσ(γ*, N) = [σ 1/2 (γ*,N) - σ ((3)/(2)) (γ*, N)] was obtained from a global fit of all the data collected by the experiments measuring spin asymmetries in polarized lepton - polarized nucleon deep inelastic scattering. This work present a phenomenological and a numerical description of all the polarized deep inelastic data (Δσ(γ*, N), g l spin structure function) on the whole measured kinematical range (0.3 GeV 2 2 2 , 4 GeV 2 2 2 ). The fit also provide reliable predictions for the photo-production limit through a smooth Q 2 -transition

On the area expectation values in area tensor Regge calculus in the Lorentzian domain

International Nuclear Information System (INIS)

Khatsymovsky, V.M.

2006-01-01

Wick rotation in area tensor Regge calculus is considered. The heuristical expectation is confirmed that the Lorentzian quantum measure on a spacelike area should coincide with the Euclidean measure at the same argument. The consequence is validity of probabilistic interpretation of the Lorentzian measure as well (on the real, i.e. spacelike areas)

The two-loop symbol of all multi-Regge regions

International Nuclear Information System (INIS)

Bargheer, Till; Papathanasiou, Georgios; Schomerus, Volker

2016-01-01

We study the symbol of the two-loop n-gluon MHV amplitude for all Mandelstam regions in multi-Regge kinematics in N=4 super Yang-Mills theory. While the number of distinct Mandelstam regions grows exponentially with n, the increase of independent symbols turns out to be merely quadratic. We uncover how to construct the symbols for any number of external gluons from just two building blocks which are naturally associated with the six- and seven-gluon amplitude, respectively. The second building block is entirely new, and in addition to its symbol, we also construct a prototype function that correctly reproduces all terms of maximal functional transcendentality.

The two-loop symbol of all multi-Regge regions

International Nuclear Information System (INIS)

Bargheer, Till; Schomerus, Volker; Papathanasiou, Georgios

2015-12-01

We study the symbol of the two-loop n-gluon MHV amplitude for all Mandelstam regions in multi-Regge kinematics in N= 4 super Yang-Mills theory. While the number of distinct Mandelstam regions grows exponentially with n, the increase of independent symbols turns out to be merely quadratic. We uncover how to construct the symbols for any number of external gluons from just two building blocks which are naturally associated with the six- and seven-gluon amplitude, respectively. The second building block is entirely new, and in addition to its symbol, we also construct a prototype function that correctly reproduces all terms of maximal functional transcendentality.

Regge behavior saves string theory from causality violations

DEFF Research Database (Denmark)

di Vecchia, Paolo; Giuseppe, D'Appollonio; Russo, Rodolfo

2015-01-01

Higher-derivative corrections to the Einstein-Hilbert action are present in bosonic string theory leading to the potential causality violations recently pointed out by Camanho et al. [1]. We analyze in detail this question by considering high-energy string-brane collisions at impact parameters b....... Such violations are instead neatly avoided when the full structure of string theory — and in particular its Regge behavior — is taken into account....... ≤ l s (the string-length parameter) with l s ≫ R p (the characteristic scale of the Dp-brane geometry). If we keep only the contribution of the massless states causality is violated for a set of initial states whose polarization is suitably chosen with respect to the impact parameter vector...

A new approach to perturbative and non-perturbative dynamics: Regge intercept and the gluon spin

International Nuclear Information System (INIS)

Bishari, M.

1979-01-01

Relations connecting long distance with short distance dynamics are proposed. These relations are independent of the (apiori unknown) matching length scale, and provide interrelations among parameters characterizing soft and hard scattering processes. In particular, the observed planar Regge intercept imply an underlying field theory mediated by vector gluons. (author)

Analysis of the logarithmic slope of F2 from the Regge gluon density behavior at small x

International Nuclear Information System (INIS)

Boroun, G. R.

2010-01-01

We study the accuracy of the Regge behavior of the gluon distribution function for an approximate relation that is frequently used to extract the logarithmic slopes of the structure function from the gluon distribution at small x. We show that the Regge behavior analysis results are comparable with HERA data and are also better than other methods that expand the gluon density at distinct points of expansion. We also show that for Q 2 = 22.4 GeV 2 , the x dependence of the data is well described by gluon shadowing corrections to the GLR-MQ equation. The resulting analytic expression allows us to predict the logarithmic derivative ∂F 2 (x, Q 2 )/∂lnQ 2 and to compare the results with the H1 data and a QCD analysis fit with the MRST parameterization input.

Boundary actions in Ponzano-Regge discretization, Quantum groups and AdS(3)

OpenAIRE

O'Loughlin, Martin

2000-01-01

Boundary actions for three-dimensional quantum gravity in the discretized formalism of Ponzano-Regge are studied with a view towards understanding the boundary degrees of freedom. These degrees of freedom postulated in the holography hypothesis are supposed to be characteristic of quantum gravity theories. In particular it is expected that some of these degrees of freedom reside on black hole horizons. This paper is a study of these ideas in the context of a theory of quantum gravity that req...

Proton-proton total cross sections and the neglect of masses in data fitting in the Regge region

International Nuclear Information System (INIS)

Kamran, M.

1981-01-01

It is shown by taking the example of pp total cross sections that the use of the approximation s is appoximately equal to 2qsup(1/2) while fitting data in the Regge region can be misleading. Several standard fits to sigmasub(tot)pp data are based on the assumption of weak rho-f-ω-A 2 exchange degeneracy (EXD). However, these fits involve the use of the approximation mentioned. It is found that it is impossible to fit the sigmasub(tot)pp data in the range 6 2 EXD. This investigation shows that sigmasub(tot)pp data alone seem to indicate either a breaking of weak rho-f-ω-A 2 EXD or the presence of low-lying contributions, or both, provided the masses of the interacting particles in data fitting in the Regge region ((Pi)ab>=5GeV/c) are not ignored

Can the "standard" unitarized Regge models describe the TOTEM data?

CERN Document Server

Alkin, A; Martynov, E

2013-01-01

The standard Regge poles are considered as inputs for two unitarization methods: eikonal and U-matrix. It is shown that only models with three input pomerons and two input odderons can describe the high energy data on $pp$ and $\\bar pp$ elastic scattering including the new data from Tevatron and LHC. However, it seems that the both considered models require a further modification (e.g. nonlinear reggeon trajectories and/or nonexponential vertex functions) for a more satisfactory description of the data at 19.0 GeV$\\leq \\sqrt{s}\\leq$ 7 TeV and 0.01 $\\leq |t|\\leq $14.2 GeV$^{2}$.

Regularities in hadron systematics, Regge trajectories and a string quark model

International Nuclear Information System (INIS)

Chekanov, S.V.; Levchenko, B.B.

2006-08-01

An empirical principle for the construction of a linear relationship between the total angular momentum and squared-mass of baryons is proposed. In order to examine linearity of the trajectories, a rigorous least-squares regression analysis was performed. Unlike the standard Regge-Chew-Frautschi approach, the constructed trajectories do not have non-linear behaviour. A similar regularity may exist for lowest-mass mesons. The linear baryonic trajectories are well described by a semi-classical picture based on a spinning relativistic string with tension. The obtained numerical solution of this model was used to extract the (di)quark masses. (orig.)

Analytic properties of high energy production amplitudes in N=4 SUSY

International Nuclear Information System (INIS)

Lipatov, L.N.; Hamburg Univ.

2010-08-01

We investigate analytic properties of the six point planar amplitude in N=4 SUSY at the multi-Regge kinematics for final state particles. For inelastic processes the Steinmann relations play an important role because they give a possibility to fix the phase structure of the Regge pole and Mandelstam cut contributions. The analyticity and factorization constraints allow us to reproduce the two-loop correction to the 6- point BDS amplitude in N=4 SUSY obtained earlier in the leading logarithmic approximation with the use of the s-channel unitarity. The cut contribution has the Moebius invariant form in the transverse momentum subspace. The exponentiation hypothesis for the amplitude in the multi-Regge kinematics is also investigated in LLA. (orig.)

Analytic properties of high energy production amplitudes in N=4 SUSY

Energy Technology Data Exchange (ETDEWEB)

Lipatov, L.N. [St. Petersburg Inst. of Nuclear Physics, Gatchina (Russian Federation); Hamburg Univ. (Germany). 1. Inst. fuer Theoretische Physik

2010-08-15

We investigate analytic properties of the six point planar amplitude in N=4 SUSY at the multi-Regge kinematics for final state particles. For inelastic processes the Steinmann relations play an important role because they give a possibility to fix the phase structure of the Regge pole and Mandelstam cut contributions. The analyticity and factorization constraints allow us to reproduce the two-loop correction to the 6- point BDS amplitude in N=4 SUSY obtained earlier in the leading logarithmic approximation with the use of the s-channel unitarity. The cut contribution has the Moebius invariant form in the transverse momentum subspace. The exponentiation hypothesis for the amplitude in the multi-Regge kinematics is also investigated in LLA. (orig.)

Distributed mean curvature on a discrete manifold for Regge calculus

International Nuclear Information System (INIS)

Conboye, Rory; Miller, Warner A; Ray, Shannon

2015-01-01

The integrated mean curvature of a simplicial manifold is well understood in both Regge Calculus and Discrete Differential Geometry. However, a well motivated pointwise definition of curvature requires a careful choice of the volume over which to uniformly distribute the local integrated curvature. We show that hybrid cells formed using both the simplicial lattice and its circumcentric dual emerge as a remarkably natural structure for the distribution of this local integrated curvature. These hybrid cells form a complete tessellation of the simplicial manifold, contain a geometric orthonormal basis, and are also shown to give a pointwise mean curvature with a natural interpretation as the fractional rate of change of the normal vector. (paper)

Distributed mean curvature on a discrete manifold for Regge calculus

Science.gov (United States)

Conboye, Rory; Miller, Warner A.; Ray, Shannon

2015-09-01

The integrated mean curvature of a simplicial manifold is well understood in both Regge Calculus and Discrete Differential Geometry. However, a well motivated pointwise definition of curvature requires a careful choice of the volume over which to uniformly distribute the local integrated curvature. We show that hybrid cells formed using both the simplicial lattice and its circumcentric dual emerge as a remarkably natural structure for the distribution of this local integrated curvature. These hybrid cells form a complete tessellation of the simplicial manifold, contain a geometric orthonormal basis, and are also shown to give a pointwise mean curvature with a natural interpretation as the fractional rate of change of the normal vector.

Subleading Regge limit from a soft anomalous dimension

Science.gov (United States)

Brüser, Robin; Caron-Huot, Simon; Henn, Johannes M.

2018-04-01

Wilson lines capture important features of scattering amplitudes, for example soft effects relevant for infrared divergences, and the Regge limit. Beyond the leading power approximation, corrections to the eikonal picture have to be taken into account. In this paper, we study such corrections in a model of massive scattering amplitudes in N=4 super Yang-Mills, in the planar limit, where the mass is generated through a Higgs mechanism. Using known three-loop analytic expressions for the scattering amplitude, we find that the first power suppressed term has a very simple form, equal to a single power law. We propose that its exponent is governed by the anomalous dimension of a Wilson loop with a scalar inserted at the cusp, and we provide perturbative evidence for this proposal. We also analyze other limits of the amplitude and conjecture an exact formula for a total cross-section at high energies.

A critical Pomeron-s view of the total and triple-Regge inclusive cross-sections

International Nuclear Information System (INIS)

Della Selva, A.; Masperi, L.; Ungkitchanukit, A.; Roberto, V.

1977-04-01

An investigation of the total and triple Regge inclusive cross-sections is carried out using a critical pomeron in the framework of reggeon field theory with thresholds. For a model with P and the conventional P' and ω poles, the rise of the total cross-section cannot be accounted for. However, in a model with a single dual-unitarization type vacuum singularity and the ω pole, the data can be adequately described

Regge-like relation and a universal description of heavy-light systems

Energy Technology Data Exchange (ETDEWEB)

Chen, Kan; Liu, Xiang [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Lanzhou University, Research Center for Hadron and CSR Physics, Institute of Modern Physics of CAS, Lanzhou (China); Dong, Yubing [Institute of High Energy Physics, CAS, Beijing (China); Theoretical Physics Center for Science Facilities (TPCSF), CAS, Beijing (China); University of Chinese Academy of Sciences, School of Physical Sciences, Beijing (China); Lue, Qi-Fang [Institute of High Energy Physics, CAS, Beijing (China); Hunan Normal University, Synergetic Innovation Center for Quantum Effects and Applications (SICQEA), Changsha (China); Matsuki, Takayuki [Tokyo Kasei University, Tokyo (Japan); Nishina Center, RIKEN, Theoretical Research Division, Wako, Saitama (Japan)

2018-01-15

Using the Regge-like formula (M - m{sub Q}){sup 2} = πσL between hadron mass M and angular momentum L with a heavy quark mass m{sub Q} and a string tension σ, we analyze all the heavy-light systems, i.e., D/D{sub s}/B/B{sub s} mesons and charmed and bottom baryons. Numerical plots are obtained for all the heavy-light mesons of experimental data whose slope becomes nearly equal to 1/2 of that for light hadrons. Assuming that charmed and bottom baryons consist of one heavy quark and one light cluster of two light quarks (diquark), we apply the formula to all the heavy-light baryons including the recently discovered Ω{sub c} and find that these baryons experimentally measured satisfy the above formula. We predict the average mass values of B, B{sub s}, Λ{sub b}, Σ{sub c}, Ξ{sub c}, and Ω{sub c} with L = 2 to be 6.01, 6.13, 6.15, 3.05, 3.07, and 3.34 GeV, respectively. Our results on baryons suggest that these baryons can be safely regarded as heavy quark-light cluster configuration. We also find a universal description for all the heavy-light mesons as well as baryons, i.e., one unique line is enough to describe both of charmed and bottom heavy-light systems. Our results suggest that instead of mass itself, gluon flux energy is essential to obtain a linear trajectory. Our method gives a straight line for B{sub c} although the curved parent Regge trajectory was suggested before. (orig.)

Mesonic and baryonic Regge trajectories with quantized masses

International Nuclear Information System (INIS)

Hothi, N.; Bisht, S.

2011-01-01

We have constructed some Regge trajectories for mesons and baryons by taking the 70 MeV spinless mass quanta as the ultimate building block for the light hadrons. In order to make masses integral multiples of seventy, small changes in masses has been made with due explanation. We have shown how a linear relationship between J and M 2 is maintained by considering quantized hadron masses, which is a direct consequence of the string model and gives a strong clue for quark confinement. It has also been established that mesons and baryons have different slopes and the slopes of baryons is less than the slope of the mesons. This clearly defies the concept of universality of slopes (α ≅ 1.1 GeV 2 ) of hadrons, which can only be achieved if the strings joining the quarks have constant string tension α 1/(2πω) (where ω is the string tension). (author)

A Kirchhoff-like conservation law in Regge calculus

International Nuclear Information System (INIS)

Gentle, Adrian P; Kheyfets, Arkady; McDonald, Jonathan R; Miller, Warner A

2009-01-01

Simplicial lattices provide an elegant framework for discrete spacetimes. The inherent orthogonality between a simplicial lattice and its circumcentric dual yields an austere representation of spacetime which provides a conceptually simple form of Einstein's geometric theory of gravitation. A sufficient understanding of simplicial spacetimes has been demonstrated in the literature for spacetimes devoid of all non-gravitational sources. However, this understanding has not been adequately extended to non-vacuum spacetime models. Consequently, a deep understanding of the diffeomorphic structure of the discrete theory is lacking. Conservation laws and symmetry properties are attractive starting points for coupling matter with the lattice. We present a simplicial form of the contracted Bianchi identity which is based on the E Cartan moment of rotation operator. This identity manifests itself in the conceptually simple form of a Kirchhoff-like conservation law. This conservation law enables one to extend Regge calculus to non-vacuum spacetimes and provides a deeper understanding of the simplicial diffeomorphism group.

Ostrogradski approach for the Regge-Teitelboim type cosmology

International Nuclear Information System (INIS)

Cordero, Ruben; Molgado, Alberto; Rojas, Efrain

2009-01-01

We present an alternative geometric inspired derivation of the quantum cosmology arising from a brane universe in the context of geodetic gravity. We set up the Regge-Teitelboim model to describe our universe, and we recover its original dynamics by thinking of such field theory as a second-order derivative theory. We refer to an Ostrogradski Hamiltonian formalism to prepare the system to its quantization. Our analysis highlights the second-order derivative nature of the RT model and the inherited geometrical aspect of the theory. A canonical transformation brings us to the internal physical geometry of the theory and induces its quantization straightforwardly. By using the Dirac canonical quantization method our approach comprises the management of both first- and second-class constraints where the counting of degrees of freedom follows accordingly. At the quantum level our Wheeler-De Witt equation agrees with previous results recently found. On these lines, we also comment upon the compatibility of our approach with the Hamiltonian approach proposed by Davidson and coworkers.

Spin-dependent structure functions of sea quarks in the framework of nonperturbative QCD and new Regge trajectory

International Nuclear Information System (INIS)

Dorokhov, A.E.; Kochelev, N.I.

1991-01-01

Within the model of QCD vacuum as an instanton liquid the spin-dependent structure functions of sea quarks are obtained. It is shown that the EMC data manages the definition of new Regge trajectory connected with the axial anomaly. The model explains the modern experimental data on the sea quark structure functions. 23 refs.; 3 figs

Regge behaviour of structure function and gluon distribution at low-x in leading order

International Nuclear Information System (INIS)

Sarma, J.K.

2000-01-01

We present a method to find the gluon distribution from the F 2 proton structure function data at low-x assuming the Regge behaviour of the gluon distribution function at this limit. We use the leading order (LO) Altarelli-Parisi (AP) evolution equation in our analysis and compare our result with those of other authors. We also discuss the limitations of the Taylor expansion method in extracting the gluon distribution from the F 2 structure function used by those authors. (orig.)

Reg geology: An elementary introduction

International Nuclear Information System (INIS)

Carreras, B.; Fernandez, E.

1973-01-01

The purpose of these notes is to given an elementary introduction to the ideas underlying the Regge-type models. In lectures 1 and 2 the connection between the exchange models and the Regge form of the amplitude is shown. In lecture 3 the analytic continuation of the amplitude from the t-channel to the s-schanel is considered, leading to the Regge-type expression, and then (lecture 4), some phenomenological applications are discussed. Lectures 5 and 6 are a generalization of 3 and 4 to the scattering of non-zero spin particles. finally (lectures 7,8 and 9) Regge cuts are introduced and new phenomenological applications are discussed. (Author)

Reg geology: An elementary introduction; Reggeologia: una introduccion elemental

Energy Technology Data Exchange (ETDEWEB)

Carreras, B; Fernandez, E

1973-07-01

The purpose of these notes is to given an elementary introduction to the ideas underlying the Regge-type models. In lectures 1 and 2 the connection between the exchange models and the Regge form of the amplitude is shown. In lecture 3 the analytic continuation of the amplitude from the t-channel to the s-schanel is considered, leading to the Regge-type expression, and then (lecture 4), some phenomenological applications are discussed. Lectures 5 and 6 are a generalization of 3 and 4 to the scattering of non-zero spin particles. finally (lectures 7,8 and 9) Regge cuts are introduced and new phenomenological applications are discussed. (Author)

On the role of individualized Regge poles in forming refractive structures in light and heavy ion scattering at large angles

International Nuclear Information System (INIS)

Kuznichenko, A.V.; Onyshchenko, G.M.; Pilipenko, V.V.; Burtebaev, N.; Zhurunbayeva, G.S.

2002-01-01

Investigation of the refraction structures in cross sections of nuclear scattering is a well-known method of probing the interior parts of the interaction region of colliding nuclei and attracts much attention. During recent years essential success was achieved in the experimental studies of scattering of light and heavy ions in wide scattering angle range. The studies were carried out not only in the energy region with standard nuclear rainbow behavior but also at energies near and below the critical energy of nuclear rainbow E cr which revealed well pronounced refractive structures in the angular distributions of the processes studied including rainbow-like maximums and anomalous large angle scattering. To analyze evolution of the refraction effects with energy a new S-matrix model, which can supplement the results of the analyses on the basis of commonly used optical potential approach. The S-matrix model takes into account of some Regge poles near the real axis ('individualized' poles), which addresses the case of energies near and below E cr . Basing on developed model a number a scattering patterns for system α+A, 16 O+ 16 O and 16 O+ 12 C at different energy values have been analyzed. The comparison with results of optical model analyses have been made. The studies were complemented by the analysis on basis of the modified Fuller procedure of decomposition of cross sections into near and far components with removing unphysical contributions. The results of analysis performed suggest the conclusion that the observed refractive structures at large angles (both the rainbow-like ones and ALAS) at E≤E cr are strongly affected by the above mentioned individualized Regge poles. Strictly saying, the scattering in this energy region is not a pure rainbow one, but is of transition character. The arising Regge poles can be considered as a quantum analog for the transition to the orbiting regime in the case of classical scattering. The notch test of the sensitivity

Application of a Regge model to the photoproduction of pion pairs

Energy Technology Data Exchange (ETDEWEB)

Bolz, Arthur; Sauter, Michel; Schoening, Andre [Physikalisches Institut, Universitaet Heidelberg, Im Neuenheimer Feld 226, D-69120 Heidelberg (Germany); Ewerz, Carlo [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, D-69120 Heidelberg (Germany); ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt (Germany); Maniatis, Markos [Departamento de Ciencias Basicas, Universidad del Bio-Bio, Avda. Andres Bello s/n, Casilla 447, Chillan 3780000 (Chile); Nachtmann, Otto [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, D-69120 Heidelberg (Germany)

2015-07-01

In a recent publication (arXiv:1409.8483) a model in the spirit of Regge theory is used to describe the reaction γp → π{sup +}π{sup -} p at high energies. Both resonant pion-pion production via the meson resonances ρ(770), ω(782), ρ(1450) and f{sub 2}(1270) as well as non-resonant amplitudes are considered. Photon and proton interact by the exchange of the photon, the pomeron and reggeons as well as by a yet unobserved but possible odderon. Cross sections calculated from this model and their dependencies on various kinematic quantities are discussed and compared to experimental data. The focus is on angular distributions which feature asymmetries that could be used for an odderon discovery.

Regge vertex for quark production in the central rapidity region in the next-to-leading order

Energy Technology Data Exchange (ETDEWEB)

Kozlov, M. G., E-mail: M.G.Kozlov@inp.nsk.su; Reznichenko, A. V., E-mail: A.V.Reznichenko@inp.nsk.su [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

2016-03-15

The effective vertex for quark production in the interaction of a Reggeized quark and a Reggeized gluon is calculated in the next-to-leading order (NLO). The resulting vertex is the missing component of the NLO multi-Regge amplitude featuring quark and gluon exchanges in the t channels. This calculation will make it possible to develop in future the bootstrap approach to proving quark Reggeization in the next-to-leading logarithmic approximation.

Reggeon, Pomeron and Glueball, Odderon-Hadron-Hadron Interaction at High Energies--From Regge Theory to Quantum Chromodynamics

Institute of Scientific and Technical Information of China (English)

XIONG Wen-Yuan; HU Zhao-Hui; WANG Xin-Wen; ZHOU Li-Juan; XIA Li-Xin; MA Wei-Xing

2008-01-01

Based on analysis of scattering matrix S, and its properties such as analyticity, unitarity, Lorentz invariance, and crossing symmetry relation, the Regge theory was proposed to describe hadron-hadron scattering at high energies before the advent of QCD, and correspondingly a Reggeon concept was born as a mediator of strongly interaction. This theory serves as a successful approach and has explained a great number of experimental data successfully, which proves that the Regge theory can be regarded as a basic theory of hadron interaction at high energies and its validity in many applications. However, as new experimental data come out, we have some difficulties in explaining the data. The new experimental total cross section violates the predictions of Regge theory, which shows that Regge formalism is limited in its applications to high energy data. To understand new experimental measurements, a new exchange theory was consequently born and its mediator is called Pomeron, which has vacuum quantum numbers. The new theory named as Pomeron exchange theory which reproduces the new experimental data of diffractive processes successfully. There are two exchange mediators: Reggeon and Pomeron. Reggeon exchange theory can only produce data at the relatively lower energy region, while Pomeron exchange theory fits the data only at higher-energy region, separately. In order to explain the data in the whole energy region, we propose a Reggeon-Pomeron model to describe high-energy hadron-hadron scattering and other diffractive processes. Although the Reggeon-Pomeron model is successful in describing high-energy hadron-hadron interaction in the whole energy region, it is a phenomenological model After the advent of QCD, people try to reveal the mystery of the phenomenological theory from QCD since hadron-hadron processes is a strong interaction, which is believed to be described by QCD. According to this point of view, we study the QCD nature of Reggeon and Pomeron. We claim

The proton structure function F sub 2 sup p (x, Q sup 2) at small x in the framework of extended Regge-Eikonal approach

CERN Document Server

Petrov, V A

2001-01-01

The behaviour of the proton structure function F sub 2 sup p (x, Q sup 2) in the region of small x is described in the framework of the generalized off-shell extention of the Regge-eikonal approach which automatically takes into account off-shell unitarity. A good quality is achieved of description of the experimental data for x < 10 sup - sup 2 and it is argued that the data on F sub 2 sup p (x, Q sup 2) measured at HERA can be fairly well described with classical universal Regge trajectories. No extra, hard trajectories of high intercept are needed for that. The x, Q sup 2 slopes and the effective intercept are discussed as functions of x and Q sup 2

Masses and Regge trajectories of triply heavy Ω{sub ccc} and Ω{sub bbb} baryons

Energy Technology Data Exchange (ETDEWEB)

Shah, Zalak; Rai, Ajay Kumar [Sardar Vallabhbhai National Institute of Technology, Department of Applied Physics, Surat, Gujarat (India)

2017-10-15

The excited state masses of triply charm and triply bottom Ω baryons are exhibited in the present study. The masses are computed for 1S-5S, 1P-5P, 1D-4D and 1F-2F states in the Hypercentral Constituent Quark Model (hCQM) with the hyper Coulomb plus linear potential. The triply charm/bottom baryon masses are experimentally unknown so that the Regge trajectories are plotted using computed masses to assign the quantum numbers of these unknown states. (orig.)

On asymptotic solutions of Regge field theory in zero transverse dimensions

International Nuclear Information System (INIS)

Bondarenko, S.; Horwitz, L.; Levitan, J.; Yahalom, A.

2013-01-01

An investigation of dynamical properties of solutions of a toy model of interacting Pomerons with triple vertex in zero transverse dimension is performed. Stable points and corresponding solutions at the limit of large rapidity are studied in the framework of a given model. It is shown that, at large rapidity, the “fan” amplitude is also a leading solution for the full RFT-0 (Regge Field Theory in zero transverse dimensions) Hamiltonian with both vertices of Pomeron splitting and merging included. An analytical form of the symmetrical solution of the equations of motion at high energy is obtained as well. For the solutions we have found, the scattering amplitude at large values of rapidity is calculated. Stability of the solutions is investigated by Lyapunov functions and the presence of closed cycles in solutions is demonstrated by the new method

Regge meets collinear in strongly-coupled N=4 super Yang-Mills

Energy Technology Data Exchange (ETDEWEB)

Sprenger, Martin [Institut für Theoretische Physik, Eidgenössische Technische Hochschule Zürich,Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland)

2017-01-10

We revisit the calculation of the six-gluon remainder function in planar N=4 super Yang-Mills theory from the strong coupling TBA in the multi-Regge limit and identify an infinite set of kinematically subleading terms. These new terms can be compared to the strong coupling limit of the finite-coupling expressions for the impact factor and the BFKL eigenvalue proposed by Basso et al. in https://www.doi.org/10.1007/JHEP01(2015)027, which were obtained from an analytic continuation of the Wilson loop OPE. After comparing the results order by order in those subleading terms, we show that it is possible to precisely map both formalisms onto each other. A similar calculation can be carried out for the seven-gluon amplitude, the result of which shows that the central emission vertex does not become trivial at strong coupling.

Diphoton production at Tevatron in the quasi-multiple-Regge-kinematics approach

Energy Technology Data Exchange (ETDEWEB)

Saleev, V.A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Samarskij Gosudarstvennyj Univ., Samara (Russian Federation)

2009-12-15

We study the production of prompt diphotons in the central region of rapidity within the frame- work of the quasi-multi-Regge-kinematics approach applying the hypothesis of quark and gluon Reggeization. We describe accurately and without free parameters the experimental data which were obtained by the CDF Collaboration at the Tevatron Collider. It is shown that the main contribution to studied process is given by the direct fusion of two Reggeized gluons into a photon pair, which is described by the effective Reggeon-Reggeon to particle-particle vertex. The contribution from the annihilation of Reggeized quark-antiquark pair into a diphoton is also considered. At the stage of numerical calculations we use the Kimber-Martin-Ryskin prescription for unintegrated quark and gluon distribution functions, with the Martin-Roberts-Stirling-Thorne collinear parton densities for a proton as input. (orig.)

Dynamical equations for a Regge theory with crossing symmetry and unitarity. II. The case of strong coupling, and elimination of ghost poles

International Nuclear Information System (INIS)

Johnson, P.W.; Warnock, R.L.

1977-01-01

Equations for the construction of a crossing-symmetric unitary Regge theory of meson-meson scattering are described. In the case of strong coupling, Regge trajectories are to be generated dynamically as zeros of the D function in a nonlinear N/D system. This paper is concerned mainly with writing the inputs to the N/D system in such a way that a convergent theory with exact crossing symmetry is defined. The scheme demands elimination of ghosts, i.e., bound-state poles at energies below threshold where trajectories pass through zero. A method for ghost elimination is proposed which entails an s-wave subtraction constant, and allows the physical s wave to be different from the l-analytic amplitude evaluated at l = 0. A dynamical model is suggested in which the subtraction constant alone generates the meson-meson interaction. An alternative ghost-elimination scheme proposed by Gell-Mann, in which only l-analytic amplitudes are involved, can be discussed in a formalism including channels with spin

Tracing back resonances to families of Regge trajectories. New finite energy sum rules

International Nuclear Information System (INIS)

Mandelbrojt, Jacques.

1975-04-01

An amplitude is supposed to be expressed for large enough energies as a sum of contributions of Regge poles. Calling family of trajectories the set of trajectories which differ by integers from one of them, a correspondance, such that the energy and width of a given resonance depend on only family of trajectories, is established between resonances of the amplitude and families of trajectories. The contribution to the amplitude of each family of trajectories is shown to satisfy the same finite energy sum rules as does the amplitude itself. In these sum rules the resonance approximation can be made where the only resonances that will appear are those which are in correspondence with the family [fr

Regge trajectories and Hagedorn behavior: Hadronic realizations of dynamical dark matter

Science.gov (United States)

Dienes, Keith R.; Huang, Fei; Su, Shufang; Thomas, Brooks

2017-11-01

Dynamical Dark Matter (DDM) is an alternative framework for dark-matter physics in which the dark sector comprises a vast ensemble of particle species whose Standard-Model decay widths are balanced against their cosmological abundances. In this talk, we study the properties of a hitherto-unexplored class of DDM ensembles in which the ensemble constituents are the "hadronic" resonances associated with the confining phase of a strongly-coupled dark sector. Such ensembles exhibit masses lying along Regge trajectories and Hagedorn-like densities of states that grow exponentially with mass. We investigate the applicable constraints on such dark-"hadronic" DDM ensembles and find that these constraints permit a broad range of mass and confinement scales for these ensembles. We also find that the distribution of the total present-day abundance across the ensemble is highly correlated with the values of these scales. This talk reports on research originally presented in Ref. [1].

Six-point remainder function in multi-Regge-kinematics: an efficient approach in momentum space

Energy Technology Data Exchange (ETDEWEB)

Broedel, Johannes [Institut für Theoretische Physik, Eidgenössische Technische Hochschule Zürich,Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland); Institut für Mathematik und Institut für Physik, Humboldt-Universität zu Berlin,IRIS Adlershof, Zum Großen Windkanal 6, 12489 Berlin (Germany); Sprenger, Martin [Institut für Theoretische Physik, Eidgenössische Technische Hochschule Zürich,Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland)

2016-05-10

Starting from the known all-order expressions for the BFKL eigenvalue and impact factor, we establish a formalism allowing the direct calculation of the six-point remainder function in N=4 super-Yang-Mills theory in momentum space to — in principle — all orders in perturbation theory. Based upon identities which relate different integrals contributing to the inverse Fourier-Mellin transform recursively, the formalism allows to easily access the full remainder function in multi-Regge kinematics up to 7 loops and up to 10 loops in the fourth logarithmic order. Using the formalism, we prove the all-loop formula for the leading logarithmic approximation proposed by Pennington and investigate the behavior of several newly calculated functions.

A geometric construction of the Riemann scalar curvature in Regge calculus

International Nuclear Information System (INIS)

McDonald, Jonathan R; Miller, Warner A

2008-01-01

The Riemann scalar curvature plays a central role in Einstein's geometric theory of gravity. We describe a new geometric construction of this scalar curvature invariant at an event (vertex) in a discrete spacetime geometry. This allows one to constructively measure the scalar curvature using only clocks and photons. Given recent interest in discrete pre-geometric models of quantum gravity, we believe is it ever so important to reconstruct the curvature scalar with respect to a finite number of communicating observers. This derivation makes use of a new fundamental lattice cell built from elements inherited from both the original simplicial (Delaunay) spacetime and its circumcentric dual (Voronoi) lattice. The orthogonality properties between these two lattices yield an expression for the vertex-based scalar curvature which is strikingly similar to the corresponding hinge-based expression in Regge calculus (deficit angle per unit Voronoi dual area). In particular, we show that the scalar curvature is simply a vertex-based weighted average of deficits per weighted average of dual areas

A geometric construction of the Riemann scalar curvature in Regge calculus

Science.gov (United States)

McDonald, Jonathan R.; Miller, Warner A.

2008-10-01

The Riemann scalar curvature plays a central role in Einstein's geometric theory of gravity. We describe a new geometric construction of this scalar curvature invariant at an event (vertex) in a discrete spacetime geometry. This allows one to constructively measure the scalar curvature using only clocks and photons. Given recent interest in discrete pre-geometric models of quantum gravity, we believe is it ever so important to reconstruct the curvature scalar with respect to a finite number of communicating observers. This derivation makes use of a new fundamental lattice cell built from elements inherited from both the original simplicial (Delaunay) spacetime and its circumcentric dual (Voronoi) lattice. The orthogonality properties between these two lattices yield an expression for the vertex-based scalar curvature which is strikingly similar to the corresponding hinge-based expression in Regge calculus (deficit angle per unit Voronoi dual area). In particular, we show that the scalar curvature is simply a vertex-based weighted average of deficits per weighted average of dual areas.

Integrable spin chains and scattering amplitudes

Energy Technology Data Exchange (ETDEWEB)

Bartels, J.; Prygarin, A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Lipatov, L.N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Petersburg Nuclear Physics Institute (Russian Federation); Sankt-Peterburgskij Univ., St. Petersburg (Russian Federation)

2011-04-15

In this review we show that the multi-particle scattering amplitudes in N=4 SYM at large N{sub c} and in the multi-Regge kinematics for some physical regions have the high energy behavior appearing from the contribution of the Mandelstam cuts in the complex angular momentum plane of the corresponding t-channel partial waves. These Mandelstam cuts or Regge cuts are resulting from gluon composite states in the adjoint representation of the gauge group SU(N{sub c}). In the leading logarithmic approximation (LLA) their contribution to the six point amplitude is in full agreement with the known two-loop result. The Hamiltonian for the Mandelstam states constructed from n gluons in LLA coincides with the local Hamiltonian of an integrable open spin chain. We construct the corresponding wave functions using the integrals of motion and the Baxter-Sklyanin approach. (orig.)

Regge analysis of diffractive and leading baryon structure functions from deep inelastic scattering

International Nuclear Information System (INIS)

Batista, M.; Covolan, R.J.M.; Montanha, J.

2002-01-01

In this paper we present a combined analysis of the H1 data on leading baryon and diffractive structure functions from DIS, which are handled as two components of the same semi-inclusive process. The available structure function data are analyzed in a series of fits in which three main exchanges are taken into account: the Pomeron, Reggeon, and pion. For each of these contributions, Regge factorization of the correspondent structure function is assumed. By this procedure, we extract information about the interface between the diffractive, Pomeron-dominated, region and the leading proton spectrum, which is mostly ruled by secondary exchanges. One of the main results is that the relative Reggeon contribution to the semi-inclusive structure function is much smaller than the one obtained from an analysis of the diffractive structure function alone

Nonlocal integrable PDEs from hierarchies of symmetry laws: The example of Pohlmeyer-Lund-Regge equation and its reflectionless potential solutions

Science.gov (United States)

Demontis, F.; Ortenzi, G.; van der Mee, C.

2018-04-01

By following the ideas presented by Fukumoto and Miyajima in Fukumoto and Miyajima (1996) we derive a generalized method for constructing integrable nonlocal equations starting from any bi-Hamiltonian hierarchy supplied with a recursion operator. This construction provides the right framework for the application of the full machinery of the inverse scattering transform. We pay attention to the Pohlmeyer-Lund-Regge equation coming from the nonlinear Schrödinger hierarchy and construct the formula for the reflectionless potential solutions which are generalizations of multi-solitons. Some explicit examples are discussed.

Plasma arc cutting: speed and cut quality

International Nuclear Information System (INIS)

Nemchinsky, V A; Severance, W S

2009-01-01

When cutting metal with plasma arc cutting, the walls of the cut are narrower at the bottom than at the top. This lack of squareness increases as the cutting speed increases. A model of this phenomenon, affecting cut quality, is suggested. A thin liquid layer, which separates the plasma from the solid metal to be melted, plays a key role in the suggested model. This layer decreases heat transfer from the plasma to the solid metal; the decrease is more pronounced the higher the speed and the thicker the liquid metal layer. Since the layer is thicker at the bottom of the cut, the heat transfer effectiveness is lower at the bottom. The decrease in heat transfer effectiveness is compensated by the narrowness of the cut. The suggested model allows one to calculate the profile of the cut. The result of the calculations of the cutting speeds for plates of various thicknesses, at which the squareness of the cut is acceptable, agrees well with the speeds recommended by manufacturers. The second effect considered in the paper is the deflection of the plasma jet from the vertical at a high cutting speed. A qualitative explanation of this phenomenon is given. We believe the considerations of this paper are pertinent to other types of cutting with moving heat sources.

Cutting

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Cutting KidsHealth / For Teens / Cutting What's in this article? ... Getting Help Print en español Cortarse What Is Cutting? Emma's mom first noticed the cuts when Emma ...

High energy hadron-nucleus scattering

International Nuclear Information System (INIS)

Koplik, J.; Mueller, A.H.

1975-01-01

Theoretical expectations for hadron-nucleus scattering at high energy if the basic hadron-hadron interaction is due to Regge poles and cuts arising in multiperipheral or soft field theory models are described. Experiments at Fermilab may provide a critical test of such models

Determination of cut front position in laser cutting

Science.gov (United States)

Pereira, M.; Thombansen, U.

2016-07-01

Laser cutting has a huge importance to manufacturing industry. Laser cutting machines operate with fixed technological parameters and this does not guarantee the best productivity. The adjustment of the cutting parameters during operation can improve the machine performance. Based on a coaxial measuring device it is possible to identify the cut front position during the cutting process. This paper describes the data analysis approach used to determine the cut front position for different feed rates. The cut front position was determined with good resolution, but improvements are needed to make the whole process more stable.

Experimental testing of exchangeable cutting inserts cutting ability

OpenAIRE

Čep, Robert; Janásek, Adam; Čepová, Lenka; Petrů, Jana; Hlavatý, Ivo; Car, Zlatan; Hatala, Michal

2013-01-01

The article deals with experimental testing of the cutting ability of exchangeable cutting inserts. Eleven types of exchangeable cutting inserts from five different manufacturers were tested. The tested cutting inserts were of the same shape and were different especially in material and coating types. The main aim was both to select a suitable test for determination of the cutting ability of exchangeable cutting inserts and to design such testing procedure that could make it possible...

Observables of QCD diffraction

Science.gov (United States)

Mieskolainen, Mikael; Orava, Risto

2017-03-01

A new combinatorial vector space measurement model is introduced for soft QCD diffraction. The model independent mathematical construction resolves experimental complications; the theoretical framework of the approach includes the Good-Walker view of diffraction, Regge phenomenology together with AGK cutting rules and random fluctuations.

Determination of cut front position in laser cutting

International Nuclear Information System (INIS)

Pereira, M; Thombansen, U

2016-01-01

Laser cutting has a huge importance to manufacturing industry. Laser cutting machines operate with fixed technological parameters and this does not guarantee the best productivity. The adjustment of the cutting parameters during operation can improve the machine performance. Based on a coaxial measuring device it is possible to identify the cut front position during the cutting process. This paper describes the data analysis approach used to determine the cut front position for different feed rates. The cut front position was determined with good resolution, but improvements are needed to make the whole process more stable. (paper)

Inclusive b and b anti b production with quasi-multi-Regge kinematics at the Tevatron

Energy Technology Data Exchange (ETDEWEB)

Kniehl, B.A. [Hamburg Univ. (Germany). II. Institut fuer Theoretische Physik; Saleev, V.A.; Shipilova, A.V. [Samara State University (Russian Federation)

2010-03-15

We consider b-jet hadroproduction in the quasi-multi-Regge-kinematics approach based on the hypothesis of gluon and quark Reggeization in t-channel exchanges at high energies. The preliminary data on inclusive b-jet and b anti b-dijet production taken by the CDF Collaboration at the Fermilab Tevatron are well described without adjusting parameters. We find the main contribution to inclusive b-jet production to be the scattering of a Reggeized gluon and a Reggeized b-quark to a b quark, which is described by the effective Reggeon-Reggeon-quark vertex. The main contribution to b anti b-pair production arises from the scattering of two Reggeized gluons to a b anti b pair, which is described by the effective Reggeon-Reggeon-quark-quark vertex. Our analysis is based on the Kimber-Martin-Ryskin prescription for unintegrated gluon and quark distribution functions using as input the Martin-Roberts-Stirling-Thorne collinear parton distribution functions of the proton. (orig.)

Single jet and prompt-photon inclusive production with multi-Regge kinematics: From Tevatron to LHC

International Nuclear Information System (INIS)

Kniehl, B. A.; Saleev, V. A.; Shipilova, A. V.; Yatsenko, E. V.

2011-01-01

We study single jet and prompt-photon inclusive hadroproduction with multi-Regge kinematics invoking the hypothesis of parton Reggeization in t-channel exchanges at high energy. In this approach, the leading contributions are due to the fusion of two Reggeized gluons into a Yang-Mills gluon and the annihilation of a Reggeized quark-antiquark pair into a photon, respectively. Adopting the Kimber-Martin-Ryskin and Bluemlein prescriptions to derive unintegrated gluon and quark distribution functions of the proton from their collinear counterparts, for which we use the Martin-Roberts-Stirling-Thorne set, we evaluate cross section distributions in transverse momentum (p T ) and rapidity. Without adjusting any free parameters, we find good agreement with measurements by the CDF and D0 Collaborations at the Tevatron and by the ATLAS Collaboration at the LHC in the region 2p T /√(S) < or approx. 0.1, where √(S) is the hadronic c.m. energy.

Single jet and prompt-photon inclusive production with multi-Regge kinematics. From Tevatron to LHC

Energy Technology Data Exchange (ETDEWEB)

Kniehl, B.A. [Santa Barbara Univ., Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics; Saleev, V.A. [Samara State Univ. (Russian Federation); S.P. Korolyov Samara State Aerospace Univ. (Russian Federation); Shipilova, A.V. [Samara State Univ. (Russian Federation); Yatsenko, E.V. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

2011-07-15

We study single jet and prompt-photon inclusive hadroproduction with multi-Regge kinematics invoking the hypothesis of parton Reggeization in t-channel exchanges at high energy. In this approach, the leading contributions are due to the fusion of two Reggeized gluons into a Yang-Mills gluon and the annihilation of a Reggeized quark-antiquark pair into a photon, respectively. Adopting the Kimber-Martin-Ryskin prescription to derive unintegrated gluon and quark distribution functions of the proton from their collinear counterparts, for which we use the Martin-Roberts- Stirling-Thorne set, we evaluate cross section distributions in transverse momentum (p{sub T}) and rapidity. Without adjusting any free parameters, we find good agreement with measurements by the CDF and D0 Collaborations at the Tevatron and by the ATLAS Collaboration at the LHC in the region 2p{sub T}/{radical}(S)

Spectroscopy, decay properties and Regge trajectories of the B and Bs mesons

Science.gov (United States)

Kher, Virendrasinh; Devlani, Nayneshkumar; Rai, Ajay Kumar

2017-09-01

A Gaussian wave function is used for detailed study of the mass spectra of the B and BS mesons using a Cornell potential incorporated with a 𝒪(1/m) correction in the potential energy term and expansion of the kinetic energy term up to 𝒪(p10) for relativistic correction of the Hamiltonian. The predicted excited states for the B and Bs mesons are in very good agreement with results obtained by experiment. We assign B2(5747) and Bs2(5840) as the 13P2 state, B1(5721) and Bs1(5830) as the 1P1 state, B0(5732) as the 13P0 state, Bs1(5850) as the state and B(5970) as the 23S1 state. We investigate the Regge trajectories in the (J,M2) and (nr,M2) planes with their corresponding parameters. The branching ratios for leptonic and radiative-leptonic decays are estimated for the B and BS mesons. Our results are in good agreement with experimental observations as well as outcomes of other theoretical models. A. K. Rai acknowledges the financial support extended by the Department of Science of Technology, India under SERB fast track scheme SR/FTP /PS-152/2012

Core Cutting Test with Vertical Rock Cutting Rig (VRCR)

Science.gov (United States)

Yasar, Serdar; Osman Yilmaz, Ali

2017-12-01

Roadheaders are frequently used machines in mining and tunnelling, and performance prediction of roadheaders is important for project economics and stability. Several methods were proposed so far for this purpose and, rock cutting tests are the best choice. Rock cutting tests are generally divided into two groups which are namely, full scale rock cutting tests and small scale rock cutting tests. These two tests have some superiorities and deficiencies over themselves. However, in many cases, where rock sampling becomes problematic, small scale rock cutting test (core cutting test) is preferred for performance prediction, since small block samples and core samples can be conducted to rock cutting testing. Common problem for rock cutting tests are that they can be found in very limited research centres. In this study, a new mobile rock cutting testing equipment, vertical rock cutting rig (VRCR) was introduced. Standard testing procedure was conducted on seven rock samples which were the part of a former study on cutting rocks with another small scale rock cutting test. Results showed that core cutting test can be realized successfully with VRCR with the validation of paired samples t-test.

Triple-Regge analysis of the fragmentation processes p→sup(K-)μ+ and K-→sup(p)μ+ at 4.2 GeV/c

International Nuclear Information System (INIS)

Blokzijl, R.; Kluyver, J.C.; Wolters, G.F.; Metzger, W.J.; Kittel, E.W.; Shephard, W.D.; Grossman, P.; Lamb, P.

1977-01-01

The inclusive production of μ + in K - p interactions at 4.2 GeV/c has been studied. Both the target fragmentation of the proton into μ + and the beam fragmentation of the kaon into μ + have been analyzed with a triple-Regge model. In the pμ-bar + channel an effective exchange trajectory has been obtained which lies between the K and K(890) trajectories. For the K - μ-bar + channel a trajectory is found which may be interpreted as a δ trajectory lowered by one-half. (author)

Exchange mechanisms for single photo- and electroproduction using the dual fermion model

International Nuclear Information System (INIS)

Becker, L.; Weigt, G.

1976-01-01

Single pion real and virtual photoproduction data are compared with phenomenological dual fermion amplitudes, which were previously applied to quasi-two body vector and tensor meson production. The similar structures of the photon and the corresponding vector meson data (in the s-channel helicity system) such as spikes and dips, usually described by Regge pole/Regge cut interferences, are reproduced by the dual Born amplitudes. Predictions of the model for the differential cross sections, in particular their parts for natural and unnatural spin-parity t-channel exchanges as well as their mass dependence, and photon and target asymmetries are in reasonable agreement with the experimental data. (author)

Improved cutting performance in high power laser cutting

DEFF Research Database (Denmark)

Olsen, Flemming Ove

2003-01-01

Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described.......Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described....

Twice cutting method reduces tibial cutting error in unicompartmental knee arthroplasty.

Science.gov (United States)

Inui, Hiroshi; Taketomi, Shuji; Yamagami, Ryota; Sanada, Takaki; Tanaka, Sakae

2016-01-01

Bone cutting error can be one of the causes of malalignment in unicompartmental knee arthroplasty (UKA). The amount of cutting error in total knee arthroplasty has been reported. However, none have investigated cutting error in UKA. The purpose of this study was to reveal the amount of cutting error in UKA when open cutting guide was used and clarify whether cutting the tibia horizontally twice using the same cutting guide reduced the cutting errors in UKA. We measured the alignment of the tibial cutting guides, the first-cut cutting surfaces and the second cut cutting surfaces using the navigation system in 50 UKAs. Cutting error was defined as the angular difference between the cutting guide and cutting surface. The mean absolute first-cut cutting error was 1.9° (1.1° varus) in the coronal plane and 1.1° (0.6° anterior slope) in the sagittal plane, whereas the mean absolute second-cut cutting error was 1.1° (0.6° varus) in the coronal plane and 1.1° (0.4° anterior slope) in the sagittal plane. Cutting the tibia horizontally twice reduced the cutting errors in the coronal plane significantly (Pcutting the tibia horizontally twice using the same cutting guide reduced cutting error in the coronal plane. Copyright © 2014 Elsevier B.V. All rights reserved.

Study of Λ-production in target fragmentation region from rhorho interactions at 360 GeV/c in the triple regge framework

International Nuclear Information System (INIS)

Aziz, T.; Banerjee, S.; Ganguli, S.N.; Malhotra, P.K.; Raghavan, R.; Bailly, J.L.; Herquet, P.; Bruyant, F.; Caso, C.; Hrubec, J.; Marin, J.C.; Montanet, L.; Chiba, Y.; Epp, B.; Girtler, P.; Fontanelli, F.; Squarcia, S.; Trevisan, U.; Gemesy, T.; Pinter, G.; Matsumoto, S.; Mittra, I.S.; Singh, J.B.; Takahashi, K.; Tikhonova, L.A.

1985-01-01

A study of Λ production has been made in the target fragmentation region from pp interactions at 360 GeV/c. The triple Regge analysis of the double differential distribution d 2 N/d(M 2 /s)dt led to an estimate of the kaon trajectory intercept as approx.=-0.6. Comparison of the double and single inclusive distributions supports the idea of Pomeron factorization. The charged multiplicities and moments from virtual 'K + 'p interactions have been studied as a function of M, the c.m. energy of the virtual 'K + 'p system. The results agree reasonably well with the on shell K + p data. (orig.)

Fibre laser cutting stainless steel: Fluid dynamics and cut front morphology

Science.gov (United States)

Pocorni, Jetro; Powell, John; Deichsel, Eckard; Frostevarg, Jan; Kaplan, Alexander F. H.

2017-01-01

In this paper the morphology of the laser cut front generated by fibre lasers was investigated by observation of the 'frozen' cut front, additionally high speed imaging (HSI) was employed to study the fluid dynamics on the cut front while cutting. During laser cutting the morphology and flow properties of the melt film on the cut front affect cut quality parameters such as cut edge roughness and dross (residual melt attached to the bottom of the cut edge). HSI observation of melt flow down a laser cutting front using standard cutting parameters is experimentally problematic because the cut front is narrow and surrounded by the kerf walls. To compensate for this, artificial parameters are usually chosen to obtain wide cut fronts which are unrepresentative of the actual industrial process. This paper presents a new experimental cutting geometry which permits HSI of the laser cut front using standard, commercial parameters. These results suggest that the cut front produced when cutting medium section (10 mm thick) stainless steel with a fibre laser and a nitrogen assist gas is covered in humps which themselves are covered by a thin layer of liquid. HSI observation and theoretical analysis reveal that under these conditions the humps move down the cut front at an average speed of approximately 0.4 m/s while the covering liquid flows at an average speed of approximately 1.1 m/s, with an average melt depth at the bottom of the cut zone of approximately 0.17 mm.

Cutting state identification

International Nuclear Information System (INIS)

Berger, B.S.; Minis, I.; Rokni, M.

1997-01-01

Cutting states associated with the orthogonal cutting of stiff cylinders are identified through an analysis of the singular values of a Toeplitz matrix of third order cumulants of acceleration measurements. The ratio of the two pairs of largest singular values is shown to differentiate between light cutting, medium cutting, pre-chatter and chatter states. Sequences of cutting experiments were performed in which either depth of cut or turning frequency was varied. Two sequences of experiments with variable turning frequency and five with variable depth of cut, 42 cutting experiments in all, provided a database for the calculation of third order cumulants. Ratios of singular values of cumulant matrices find application in the analysis of control of orthogonal cutting

Plasma cutting or laser cutting. Plasma setsudan ka laser setsudan ka

Energy Technology Data Exchange (ETDEWEB)

Nakamura, A. (Tanaka Engineering Works Ltd., Saitama (Japan))

1991-05-01

Comparisons and discussions were made on the plasma cutting and laser cutting in sheet steel cutting, referring partly to gas cutting. Historically, the cutting has been developed from gas, plasma, and laser in that order, and currently these three methods are used mixedly. Generally, the plasma cutting is superior in cutting speed, but inferior in cut face quality, and it requires measures of dust collection. Due to high accuracy and quality in cut face, the laser cutting has been practically used for quite some time in the thin sheet industry, but medium to thick sheet cutting had a problem of unavailability of high output laser suitable for these ranges. However, the recent technologies have overcome the problem as a result of development at the authors {prime} company of a 2 kW class laser cutter capable of cutting 19 mm thick sheet. The cutter has been proven being particularly excellent in controllability. Choice of whether plasma or laser would depend upon which priority is to be taken, cost or accuracy. 15 figs., 3 tabs.

Fixed-topology Lorentzian triangulations: Quantum Regge Calculus in the Lorentzian domain

Science.gov (United States)

Tate, Kyle; Visser, Matt

2011-11-01

A key insight used in developing the theory of Causal Dynamical Triangu-lations (CDTs) is to use the causal (or light-cone) structure of Lorentzian manifolds to restrict the class of geometries appearing in the Quantum Gravity (QG) path integral. By exploiting this structure the models developed in CDTs differ from the analogous models developed in the Euclidean domain, models of (Euclidean) Dynamical Triangulations (DT), and the corresponding Lorentzian results are in many ways more "physical". In this paper we use this insight to formulate a Lorentzian signature model that is anal-ogous to the Quantum Regge Calculus (QRC) approach to Euclidean Quantum Gravity. We exploit another crucial fact about the structure of Lorentzian manifolds, namely that certain simplices are not constrained by the triangle inequalities present in Euclidean signa-ture. We show that this model is not related to QRC by a naive Wick rotation; this serves as another demonstration that the sum over Lorentzian geometries is not simply related to the sum over Euclidean geometries. By removing the triangle inequality constraints, there is more freedom to perform analytical calculations, and in addition numerical simulations are more computationally efficient. We first formulate the model in 1 + 1 dimensions, and derive scaling relations for the pure gravity path integral on the torus using two different measures. It appears relatively easy to generate "large" universes, both in spatial and temporal extent. In addition, loopto-loop amplitudes are discussed, and a transfer matrix is derived. We then also discuss the model in higher dimensions.

Wedge cutting of mild steel by CO 2 laser and cut-quality assessment in relation to normal cutting

Science.gov (United States)

Yilbas, B. S.; Karatas, C.; Uslan, I.; Keles, O.; Usta, Y.; Yilbas, Z.; Ahsan, M.

2008-10-01

In some applications, laser cutting of wedge surfaces cannot be avoided in sheet metal processing and the quality of the end product defines the applicability of the laser-cutting process in such situations. In the present study, CO 2 laser cutting of the wedge surfaces as well as normal surfaces (normal to laser beam axis) is considered and the end product quality is assessed using the international standards for thermal cutting. The cut surfaces are examined by the optical microscopy and geometric features of the cut edges such as out of flatness and dross height are measured from the micrographs. A neural network is introduced to classify the striation patterns of the cut surfaces. It is found that the dross height and out of flatness are influenced significantly by the laser output power, particularly for wedge-cutting situation. Moreover, the cut quality improves at certain value of the laser power intensity.

Refraction effects in 16O + 16O scattering at energy of 124-1120 MeV and S matrix model with Regge poles

International Nuclear Information System (INIS)

Kuznichenko, A.V.; Onishchenko, G.M.; Pilipenko, V.V.; Dem'yanova, A.S.; Burtebaev, N.

2003-01-01

The analysis of the cross sections of the 16 O + 16 O nuclei elastic scattering by the energy of 124, 145, 250, 350, 480, 704 and 1120 MeV is carried out on the basis of the phenomenological S-matrix model. It is shown, that by high energy the refraction behavior of the opalescent-type cross sections is well described by the simple smooth dependence of the S-matrix on the angular moment and by the energy E ≤ 480 MeV the opalescent-type structures are strongly effected by the Regge poles and S-matrix zeroes, close to the actual axis. The comparison with the results of the cross sections by the optical model is carried out [ru

Dual peripheral model up to Serpukhov energies

CERN Document Server

Schrempp, Barbara

1974-01-01

The high energy behaviour of the s-channel Regge residues is inferred from three plausible requirements. The resulting s-channel helicity amplitudes allow-in a dual sense-the following t-channel interpretation: for -t>or=0.25 GeV/sup 2/ the flip amplitude has the form of a t-channel Regge pole, while the non-flip amplitude looks like a Regge cut. Finally, a quantitative comparison of the predictions with the data available for the set of SU(3) related processes pi N CEX, KN, KN CEX and pi /sup -/p to eta n is performed, covering the energy range 2

Resonance-sum model for Reggeization in the scattering of particles with arbitrary spin

International Nuclear Information System (INIS)

King, M.J.; Durand, L.; Wali, K.C.

1976-01-01

Using a field-theoretic description of nonzero-spin particles, center-of-mass helicity amplitudes have been obtained which correspond to pole terms in four-particle reactions with arbitrary-spin external particles. Construction of a van Hove-Durand--type model starting from these helicity amplitudes (which have a well specified kinematic structure in the field-theoretic description) is discussed. Special attention has been paid to boson-fermion scattering. Straightforward Reggeization of helicity amplitudes assuming linear trajectories is known to produce parity doubling. One cannot have a pure fermion Regge pole unaccompanied by cuts. This conclusion has important consequences on both fitting data using Regge formulas in, say, backward scattering in boson-fermion scattering and theoretical considerations such as dual bootstrap models

Cutting forces during turning with variable depth of cut

Directory of Open Access Journals (Sweden)

M. Sadílek

2016-03-01

The proposed research for the paper is an experimental work – measuring cutting forces and monitoring of the tool wear on the cutting edge. It compares the turning where standard roughing cycle is used and the turning where the proposed roughing cycle with variable depth of cut is applied.

Cutting method and cutting device for spent fuel rod of nuclear reactor

International Nuclear Information System (INIS)

Komatsu, Masahiko; Ose, Toshihiko.

1996-01-01

A control rod transferred under water in a vertically suspended state is postured horizontally at such a water depth that radiations can be shielded, and then it is cut to a dropping speed limiting portion and a cross-like main body. The separated cross-like main body portion is further cut in the longitudinal direction and separated into a pair of cut pieces each having an L-shaped cross section. A disk like metal saw is used as a cutting tool. Alternatively, a plasma jet cutter or a melting-type water jet cutter is used as a cutting tool. Then, since the spent control rod to be cut is postured horizontally under water, the water depth for the cutting position can be reduced. As a result, the cutting state using the cutting tool can be observed by naked eyes from the position above the water surface thereby enabling to perform the cutting operation reliably. (N.H.)

Flexible Laser Metal Cutting

DEFF Research Database (Denmark)

Villumsen, Sigurd; Jørgensen, Steffen Nordahl; Kristiansen, Morten

2014-01-01

This paper describes a new flexible and fast approach to laser cutting called ROBOCUT. Combined with CAD/CAM technology, laser cutting of metal provides the flexibility to perform one-of-a-kind cutting and hereby realises mass production of customised products. Today’s laser cutting techniques...... possess, despite their wide use in industry, limitations regarding speed and geometry. Research trends point towards remote laser cutting techniques which can improve speed and geometrical freedom and hereby the competitiveness of laser cutting compared to fixed-tool-based cutting technology...... such as punching. This paper presents the concepts and preliminary test results of the ROBOCUT laser cutting technology, a technology which potentially can revolutionise laser cutting....

Some possibilities for determining cutting data when using laser cutting:

OpenAIRE

Radovanović, Miroslav

2006-01-01

The technological problems faced in the field of the application of laser-cutting machines lie in insufficient knowledge of the laser technique and the absence of both sufficiently reliable practical data and knowledge about the parameters affecting the work process itself. A significant parameter that is necessary to determine and to enter in an NC-program is the cutting speed. Various authors analyze the laser-cutting process and give mathematical models where laser cutting is modeled by us...

Remote Laser Cutting of CFRP: Improvements in the Cut Surface

Science.gov (United States)

Stock, Johannes; Zaeh, Michael F.; Conrad, Markus

In the automotive industry carbon fibre reinforced plastics (CFRP) are considered as a future key material to reduce the weight of the vehicle. Therefore, capable production techniques are required to process this material in mass industry. E.g., state of the art methods for cutting are limited by the high tool wear or the feasible feed rate. Laser cutting processes are still under investigation. This paper presents detailed new studies on remote laser cutting of CFRP focusing on the influence of the material properties and the quality of the cut surface. By adding light absorbing soot particles to the resin of the matrix, the cutting process is improved and fewer defects emerge.

Multibeam Fibre Laser Cutting

DEFF Research Database (Denmark)

Olsen, Flemming Ove

The appearance of the high power high brilliance fibre laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO2-laser. However, quality problems in fibre......-laser cutting have until now limited its application in metal cutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with high brightness short wavelength lasers will be presented. In the approach, multi beam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from 2 single mode fibre lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W of single...

Multibeam fiber laser cutting

DEFF Research Database (Denmark)

Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

2009-01-01

The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber......-laser cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

Cutting cleaner

International Nuclear Information System (INIS)

Elsen, R.P.H. van; Smits, M.

1991-01-01

This paper presents the results of a long term field test of the Cutting Cleaner, which is used for the treatment of wet oil contaminated cuttings (WOCC) produced when drilling with Oil Based Mud (OBM). It was concluded that it is possible to reduce the oil content of cuttings to an average of 1 - 2%. The recovered base oil can be reused to make new oil based mud

Laser cutting or water-jet cutting. Laser setsudan ka water-jet setsudan ka

Energy Technology Data Exchange (ETDEWEB)

Yamada, T. (Shibuya Kogyo Co. Ltd., Ishikawa (Japan))

1991-05-01

The recent spread of carbon oxide laser cutter is so startlingly fast, but at the same time, water jet cutting using ultra high pressure water stream is drawing attention as it has identical characteristics, and opens the way to cutting materials that have been hitherto difficult to cut. The authors, who are fabricators of cutters of both types, gave the comparisons and explanations on several examples referring to materials that can be cut, cutting accuracy, speed, shape and thermal effects to cut face, and running cost in detail. However, simple comparison is difficult. For instance, cutting 6 mm thick SUS sheet costs a running cost of 65 yen per meter in laser cutting, and 535 yen per meter in water jet cutting, but this situation is often reversed when other material or sheet thickness is selected. The actual situation in the sheet metal processing industry at the present time is that it uses by far more laser processing machines, and uses water jet cutters to supplement for cutting materials more difficult to cut. 10 figs., 3 tabs.

About some Regge-like relations for (stable) black holes

International Nuclear Information System (INIS)

Recami, E.; Tonin Zanchin, V.

1991-08-01

Within a purely classical formulation of ''strong gravity'', we associated hadron constituents (and even hadrons themselves) with suitable stationary, axisymmetric solutions of certain new Einstein-type equations supposed to describe the strong field inside hadrons. Such equations are nothing but Einstein equations - with cosmological term - suitably scaled down. As a consequence, the cosmological constant Λ and the masses M result in our theory to be scaled up and transformed into a ''hadronic constant'' and into ''strong masses'', respectively. Due to the unusual range of Λ and M values considered, we met a series of solutions of the Kerr-Newman-de Sitter (KNdS) type with such interesting properties that it is worth studying them - from our particular point of view - also in the case of ordinary gravity. This is the aim of the present work. The requirement that those solutions be stable, i.e., that their temperature (or surface gravity) be vanishingly small, implies the coincidence of at least two of their (in general, three) horizons. Imposing the stability condition of a certain horizon does yield (once chosen the values of J, q and Λ) mass and radius of the associated black-hole. In the case of ordinary Einstein equations and for stable black-holes of the KNdS type, we get in particular Regge-like relations among mass M, angular momentum J, charge q and cosmological constant Λ. For instance, with the standard definitions Q 2 is identical to Gq 2 /(4πε 0 c 4 ); a is identical to J/(Mc); m is identical to GM/c 2 , in the case Λ = 0 in which m 2 = a 2 + Q 2 and if q is negligible we find m 2 = J. When considering, for simplicity, Λ > 0 and J = 0 (and q still negligible), then we obtain m 2 = 1/(9Λ). In the most general case, the condition, for instance, of ''triple coincidence'' among the three horizons yields for modul Λa 2 2 = 2/(9Λ); m 2 = 8(a 2 + Q 2 )/9. Another interesting point is that - with few exceptions - all such relations (among M

Technology development for cutting a reactor pressure vessel using a mechanical cutting technique

International Nuclear Information System (INIS)

Watanabe, Masaaki; Miyasaka, Yasuhiko; Miyao, Hidehiko; Ooki, Arahiko; Ninomiya, Toshiaki; Koiwai, Masami

2001-01-01

On decommissioning of nuclear facilities, the thermal cutting technique such as an oxygen-acetylene gas cutting and a plasma arc cutting are generally used for cutting massive and thick steel structures in consideration with cutting speed and control performance. These techniques generate dust, smoke, aerosol and a large quantity of secondary waste. Mechanical cutting technique has an advantage of small amount of secondary waste, and the metal chips from the kerf recovered easily compared with these thermal cutting technique. The remote mechanical cutting system for highly activated RPV has been developed with the manner which achieves the safety and cost effectiveness. The development has been performed on consignment to RANDEC from the Science and Technology Agency of Japan. (author)

Spinorial Regge trajectories and Hagedorn-like temperatures. Spinorial space-time and preons as an alternative to strings

Science.gov (United States)

Gonzalez-Mestres, Luis

2016-11-01

The development of the statistical bootstrap model for hadrons, quarks and nuclear matter occurred during the 1960s and the 1970s in a period of exceptional theoretical creativity. And if the transition from hadrons to quarks and gluons as fundamental particles was then operated, a transition from standard particles to preons and from the standard space-time to a spinorial one may now be necessary, including related pre-Big Bang scenarios. We present here a brief historical analysis of the scientific problematic of the 1960s in Particle Physics and of its evolution until the end of the 1970s, including cosmological issues. Particular attention is devoted to the exceptional role of Rolf Hagedorn and to the progress of the statistical boostrap model until the experimental search for the quark-gluon plasma started being considered. In parallel, we simultaneously expose recent results and ideas concerning Particle Physics and in Cosmology, an discuss current open questions. Assuming preons to be constituents of the physical vacuum and the standard particles excitations of this vacuum (the superbradyon hypothesis we introduced in 1995), together with a spinorial space-time (SST), a new kind of Regge trajectories is expected to arise where the angular momentum spacing will be of 1/2 instead of 1. Standard particles can lie on such Regge trajectories inside associated internal symmetry multiplets, and the preonic vacuum structure can generate a new approach to Quantum Field Theory. As superbradyons are superluminal preons, some of the vacuum excitations can have critical speeds larger than the speed of light c, but the cosmological evolution selects by itself the particles with the smallest critical speed (the speed of light). In the new Particle Physics and Cosmology emerging from the pattern thus developed, Hagedornlike temperatures will naturally be present. As new space, time, momentum and energy scales are expected to be generated by the preonic vacuum dynamics, the

Machining of Some Difficult-to-Cut Materials with Rotary Cutting Tools

OpenAIRE

Stjernstoft, Tero

2004-01-01

Automobile and aero industries have an increasing interestin materials with improved mechanical properties. However, manyof these new materials are classified as difficult-to-cut withconventional tools. It is obvious that tools, cutting processesand cutting models has to be devel-oped parallel to materialsscience. In this thesis rotary cutting tools are tested as analternative toexpensive diamond or cubic bore nitridetools. Metal matrix composites mostly consist of a light metalalloy (such as...

Minimizing waste (off-cuts using cutting stock model: The case of one dimensional cutting stock problem in wood working industry

Directory of Open Access Journals (Sweden)

Gbemileke A. Ogunranti

2016-09-01

Full Text Available Purpose: The main objective of this study is to develop a model for solving the one dimensional cutting stock problem in the wood working industry, and develop a program for its implementation. Design/methodology/approach: This study adopts the pattern oriented approach in the formulation of the cutting stock model. A pattern generation algorithm was developed and coded using Visual basic.NET language. The cutting stock model developed is a Linear Programming (LP Model constrained by numerous feasible patterns. A LP solver was integrated with the pattern generation algorithm program to develop a one - dimensional cutting stock model application named GB Cutting Stock Program. Findings and Originality/value: Applying the model to a real life optimization problem significantly reduces material waste (off-cuts and minimizes the total stock used. The result yielded about 30.7% cost savings for company-I when the total stock materials used is compared with the former cutting plan. Also, to evaluate the efficiency of the application, Case I problem was solved using two top commercial 1D-cutting stock software.  The results show that the GB program performs better when related results were compared. Research limitations/implications: This study round up the linear programming solution for the number of pattern to cut. Practical implications: From Managerial perspective, implementing optimized cutting plans increases productivity by eliminating calculating errors and drastically reducing operator mistakes. Also, financial benefits that can annually amount to millions in cost savings can be achieved through significant material waste reduction. Originality/value: This paper developed a linear programming one dimensional cutting stock model based on a pattern generation algorithm to minimize waste in the wood working industry. To implement the model, the algorithm was coded using VisualBasic.net and linear programming solver called lpsolvedll (dynamic

Underwater cutting techniques developments

International Nuclear Information System (INIS)

Bach, F.-W.

1990-01-01

The primary circuit structures of different nuclear powerplants are constructed out of stainless steels, ferritic steels, plated ferritic steels and alloys of aluminium. According to the level of the specific radiation of these structures, it is necessary for dismantling to work with remote controlled cutting techniques. The most successful way to protect the working crew against exposure of radiation is to operate underwater in different depths. The following thermal cutting processes are more or less developed to work under water: For ferritic steels only - flame cutting; For ferritic steels, stainless steels, cladded steels and aluminium alloys - oxy-arc-cutting, arc-waterjet-cutting with a consumable electrode, arc-saw-cutting, plasma-arc-cutting and plasma-arc-saw. The flame cutting is a burning process, all the other processes are melt-cutting processes. This paper explains the different techniques, giving a short introduction of the theory, a discussion of the possibilities with the advantages and disadvantages of these processes giving a view into the further research work in this interesting field. (author)

Welding and cutting

International Nuclear Information System (INIS)

Drews, P.; Schulze Frielinghaus, W.

1978-01-01

This is a survey, with 198 literature references, of the papers published in the fields of welding and cutting within the last three years. The subjects dealt with are: weldability of the materials - Welding methods - Thermal cutting - Shaping and calculation of welded joints - Environmental protection in welding and cutting. (orig.) [de

Cutting assembly

Science.gov (United States)

Racki, Daniel J.; Swenson, Clark E.; Bencloski, William A.; Wineman, Arthur L.

1984-01-01

A cutting apparatus includes a support table mounted for movement toward and away from a workpiece and carrying a mirror which directs a cutting laser beam onto the workpiece. A carrier is rotatably and pivotally mounted on the support table between the mirror and workpiece and supports a conduit discharging gas toward the point of impingement of the laser beam on the workpiece. Means are provided for rotating the carrier relative to the support table to place the gas discharging conduit in the proper positions for cuts made in different directions on the workpiece.

Understanding the nature of {\Lambda }\left(1405\right) through Regge physics

Energy Technology Data Exchange (ETDEWEB)

Fernández-Ramírez, César; Danilkin, Igor V.; Mathieu, Vincent; Szczepaniak, Adam P.

2016-04-01

It appears that there are two resonances with $J^P= 1/2^-$ quantum numbers in the energy region near the $\\Lambda(1405)$ hyperon. The nature of these states is a topic of current debate. To provide further insight we use Regge phenomenology to access how these two resonances fit the established hyperon spectrum. We find that only one of these resonances is compatible with a three-quark state.

Restraining and neck cutting or stunning and neck cutting of veal calves.

Science.gov (United States)

Lambooij, E; van der Werf, J T N; Reimert, H G M; Hindle, V A

2012-05-01

Brain and heart activities were measured in 31 veal calves during restraining and rotating followed by neck cutting with or without stunning to evaluate welfare. After neck cutting correlation dimension analyses and %power of EEG beta wave fraction decreased gradually to lower values resulting in an induction of unconsciousness lasting on average 80s. Corneal reflex response ceased 135±57s after neck cutting. The CD scores and the %power of beta waves fell immediately after post-cut captive bolt and pre-cut electrical stunning to levels indicating unconsciousness. Heart rate in lairage increased upon entrance to the restrainer and again after rotation, heart rate variability decreased. Rotating the restrainer 90°, 120° or 180° compromised veal calf welfare and should be avoided. It is recommended to use post-cut captive bolt stunning or pre-cut electrical stunning inducing immediate unconsciousness. Copyright © 2011 Elsevier Ltd. All rights reserved.

Paper Cuts.

Science.gov (United States)

Greene, Lisa A.

1990-01-01

Describes how to create paper cuts and suggests the most appropriate materials for young children that give good quality results. Describes the methods the author, a professional artist, uses to assemble her own paper cuts and how these can be adopted by older students. (KM)

Operation of the AM-50 cutting head under different cutting conditions

Energy Technology Data Exchange (ETDEWEB)

Sikora, W; Kusz, F; Fels, M

1988-02-01

Presents results of investigations into operation of the AM-50 heading machine. About 50% of headings, i.e. about 800 km/a, are driven by about 400 heading machines. It has been found that energy consumption depends on compression strength of rock and is 6 times higher for sandstone than for clayey shale. Power consumed by cutting heads depends mainly on the web used (30-150 mm depending on rock strength). Wear of cutting tools is 1-30 pieces per meter of heading advance at a working cross-section area of 15 m/sup 2/. The AM-50 machine uses cutting speeds of 1.1-3.5 m/s. Higher speeds negatively affect the resistance to cutting. Nonuniform tool wear on the cutting head circumference is an indication of improper head design that requires remedying.

Wet cutting

Energy Technology Data Exchange (ETDEWEB)

Hole, B. [IMC Technical Services (United Kingdom)

1999-08-01

Continuous miners create dust and methane problems in underground coal mining. Control has usually been achieved using ventilation techniques as experiments with water based suppression have led to flooding and electrical problems. Recent experience in the US has led to renewed interest in wet head systems. This paper describes tests of the Hydraphase system by IMC Technologies. Ventilation around the cutting zone, quenching of hot ignition sources, dust suppression, the surface trial gallery tests, the performance of the cutting bed, and flow of air and methane around the cutting head are reviewed. 1 ref., 2 figs., 2 photos.

Fundamentals of cutting.

Science.gov (United States)

Williams, J G; Patel, Y

2016-06-06

The process of cutting is analysed in fracture mechanics terms with a view to quantifying the various parameters involved. The model used is that of orthogonal cutting with a wedge removing a layer of material or chip. The behaviour of the chip is governed by its thickness and for large radii of curvature the chip is elastic and smooth cutting occurs. For smaller thicknesses, there is a transition, first to plastic bending and then to plastic shear for small thicknesses and smooth chips are formed. The governing parameters are tool geometry, which is principally the wedge angle, and the material properties of elastic modulus, yield stress and fracture toughness. Friction can also be important. It is demonstrated that the cutting process may be quantified via these parameters, which could be useful in the study of cutting in biology.

On the Cutting Performance of Segmented Diamond Blades when Dry-Cutting Concrete.

Science.gov (United States)

Sánchez Egea, A J; Martynenko, V; Martínez Krahmer, D; López de Lacalle, L N; Benítez, A; Genovese, G

2018-02-09

The objective of the present study is to analyze and compare the cutting performance of segmented diamond blades when dry-cutting concrete. A cutting criteria is proposed to characterize the wear of the blades by measuring the variation of the external diameter and the weight loss of the blade. The results exhibit the cutting blade SB-A, which has twice the density of diamonds and large contact area, exhibits less wear even though the material removal rate is higher compared with the other two cutting blades. Additionally, the surface topography of the different blades is evaluated to examine the impact of wear depending on the surface profile and the distribution of the diamonds in the blade's matrix. Large number of diamonds pull-out are found in blades type SB-C, which additionally shows the worst wear resistant capability. As a conclusion, the cutting efficiency of the blade is found to be related to the density of embedded diamonds and the type of the surface profile of the cutting blade after reaching the stop criteria.

Device for cutting protrusions

Science.gov (United States)

Bzorgi, Fariborz M [Knoxville, TN

2011-07-05

An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

Experimental research on the durability cutting tools for cutting-off steel profiles

Directory of Open Access Journals (Sweden)

Cristea Alexandru

2017-01-01

Full Text Available The production lines used for manufacturing U-shaped profiles are very complex and they must have high productivity. One of the most important stages of the fabrication process is the cutting-off. This paper presents the experimental research and analysis of the durability of the cutting tools used for cutting-off U-shaped metal steel profiles. The results of this work can be used to predict the durability of the cutting tools.

Study of Cutting Edge Temperature and Cutting Force of End Mill Tool in High Speed Machining

Directory of Open Access Journals (Sweden)

Kiprawi Mohammad Ashaari

2017-01-01

Full Text Available A wear of cutting tools during machining process is unavoidable due to the presence of frictional forces during removing process of unwanted material of workpiece. It is unavoidable but can be controlled at slower rate if the cutting speed is fixed at certain point in order to achieve optimum cutting conditions. The wear of cutting tools is closely related with the thermal deformations that occurred between the frictional contact point of cutting edge of cutting tool and workpiece. This research paper is focused on determinations of relationship among cutting temperature, cutting speed, cutting forces and radial depth of cutting parameters. The cutting temperature is determined by using the Indium Arsenide (InAs and Indium Antimonide (InSb photocells to measure infrared radiation that are emitted from cutting tools and cutting forces is determined by using dynamometer. The high speed machining process is done by end milling the outer surface of carbon steel. The signal from the photocell is digitally visualized in the digital oscilloscope. Based on the results, the cutting temperature increased as the radial depth and cutting speed increased. The cutting forces increased when radial depth increased but decreased when cutting speed is increased. The setup for calibration and discussion of the experiment will be explained in this paper.

The Cutting Process, Chips and Cutting Forces in Machining CFRP

DEFF Research Database (Denmark)

Koplev, A.; Lystrup, Aage; Vorm, T.

1983-01-01

The cutting of unidirectional CFRP, perpendicular as well as parallel to the fibre orientation, is examined. Shaping experiments, ‘quick-stop’ experiments, and a new chip preparation technique are used for the investigation. The formation of the chips, and the quality of the machined surface...... is discussed. The cutting forces parallel and perpendicular to the cutting direction are measured for various parameters, and the results correlated to the formation of chips and the wear of the tool....

Experimental Investigation on Cutting Characteristics in Nanometric Plunge-Cutting of BK7 and Fused Silica Glasses.

Science.gov (United States)

An, Qinglong; Ming, Weiwei; Chen, Ming

2015-03-27

Ductile cutting are most widely used in fabricating high-quality optical glass components to achieve crack-free surfaces. For ultra-precision machining of brittle glass materials, critical undeformed chip thickness (CUCT) commonly plays a pivotal role in determining the transition point from ductile cutting to brittle cutting. In this research, cutting characteristics in nanometric cutting of BK7 and fused silica glasses, including machined surface morphology, surface roughness, cutting force and specific cutting energy, were investigated with nanometric plunge-cutting experiments. The same cutting speed of 300 mm/min was used in the experiments with single-crystal diamond tool. CUCT was determined according to the mentioned cutting characteristics. The results revealed that 320 nm was found as the CUCT in BK7 cutting and 50 nm was determined as the size effect of undeformed chip thickness. A high-quality machined surface could be obtained with the undeformed chip thickness between 50 and 320 nm at ductile cutting stage. Moreover, no CUCT was identified in fused silica cutting with the current cutting conditions, and brittle-fracture mechanism was confirmed as the predominant chip-separation mode throughout the nanometric cutting operation.

Analysis of changes in paper cutting forces during the cutting cycle in single-knife guillotine

OpenAIRE

Rusin, Agnieszka; Petriaszwili, Georgij

2013-01-01

Paper presents the results of changes in the three components of cutting forces of paper stacks cutting during the cutting cycle in single-knife guillotine. The changes of the three components of cutting force at different stages of cutting cycle were analyzed.

Cutting and Self-Harm

Science.gov (United States)

... Your feelings Feeling sad Cutting and self-harm Cutting and self-harm Self-harm, sometimes called self- ... There are many types of self-injury, and cutting is one type that you may have heard ...

On Permuting Cut with Contraction

OpenAIRE

Borisavljevic, Mirjana; Dosen, Kosta; Petric, Zoran

1999-01-01

The paper presents a cut-elimination procedure for intuitionistic propositional logic in which cut is eliminated directly, without introducing the multiple-cut rule mix, and in which pushing cut above contraction is one of the reduction steps. The presentation of this procedure is preceded by an analysis of Gentzen's mix-elimination procedure, made in the perspective of permuting cut with contraction. It is also shown that in the absence of implication, pushing cut above contraction doesn't p...

Model for Reggeon-Pomeranchukon cuts

International Nuclear Information System (INIS)

Chia, S.

1977-01-01

A model is presented for calculating Reggeon-Pomeranchukon cuts, making use explicitly of the Mandelstam diagram. External spins are treated in a natural way. Calculation for the general case is outlined and it is shown that in practical application the cut can be calculated in a standard way. Cuts associated with the exchanges of π, rho, B, and A 2 are considered, and characteristics of the RP cuts, as well as the structure functions, are extracted and discussed. It is found that the model differs considerably from the absorption model. Two suppression schemes are operative which control the magnitudes of cut contributions to amplitudes with ''naturality'' opposite to the Reggeon. The πP cut is found to be a unique case because of the smallness of the pion mass. In general, the RP cuts are self-conspiratorial. At very high energies, all cuts, except πP cut, exhibit quasifactorization

Cutting method for structural component into block like shape, and device used for cutting

International Nuclear Information System (INIS)

Nakazawa, Koichi; Ito, Akira; Tateiwa, Masaaki.

1995-01-01

Two grooves each of a predetermined depth are formed along a surface of a structural component, and a portion between the two grooves is cut in the direction of the depth from the surface of the structural component by using a cutting wire of a wire saw device. Then, the cutting wire is moved in the extending direction of the grooves while optionally changing the position in the direction of the depth to conduct cutting for the back face. Further, the cutting wire is moved in the direction of the depth of the groove toward the surface, to cut a portion between the two grooves. The wire saw device comprises a wire saw main body movable along the surface of the structural component, a pair of wire guide portions extending in the direction of the depth, guide pooleys capable of guiding the cutting wire guides revolvably and rotatably disposed at the top end, and an endless annular cutting wire extending between the wire guide portions. Thus, it is possible to continuously cut out blocks set to optional size and thickness. In addition, remote cutting is possible with no requirement for an operator to access to the vicinity of radioactivated portions. (N.H.)

An FMS Dynamic Production Scheduling Algorithm Considering Cutting Tool Failure and Cutting Tool Life

International Nuclear Information System (INIS)

Setiawan, A; Wangsaputra, R; Halim, A H; Martawirya, Y Y

2016-01-01

This paper deals with Flexible Manufacturing System (FMS) production rescheduling due to unavailability of cutting tools caused either of cutting tool failure or life time limit. The FMS consists of parallel identical machines integrated with an automatic material handling system and it runs fully automatically. Each machine has a same cutting tool configuration that consists of different geometrical cutting tool types on each tool magazine. The job usually takes two stages. Each stage has sequential operations allocated to machines considering the cutting tool life. In the real situation, the cutting tool can fail before the cutting tool life is reached. The objective in this paper is to develop a dynamic scheduling algorithm when a cutting tool is broken during unmanned and a rescheduling needed. The algorithm consists of four steps. The first step is generating initial schedule, the second step is determination the cutting tool failure time, the third step is determination of system status at cutting tool failure time and the fourth step is the rescheduling for unfinished jobs. The approaches to solve the problem are complete-reactive scheduling and robust-proactive scheduling. The new schedules result differences starting time and completion time of each operations from the initial schedule. (paper)

Advanced cutting techniques: laser and fissuration cutting

International Nuclear Information System (INIS)

Migliorati, B.; Gay, P.

1984-01-01

Experimental tests have been performed using CO 2 laser with output power 1 to 15 kW to evaluate the effect of varying the following parameters: material (carbon steel Fe 42 C, stainless steel AISI 304, concrete), laser power, beam characteristics, work piece velocity, gas type and distribution on the laser interaction zone. In the case of concrete, drilling depths of 80 mm were obtained in a few seconds using a 10 kW laser beam. Moreover pieces of 160 mm were cut at 0.01 meters per minute. Results with carbon steel indicated maximum thicknesses of 110 mm, cut at 0.01 meters per minute with 10 kW, depths about 20% lower were obtained with the AISI 304 stainless steel. A parallel investigation was aimed at characterizing particulate emission during the laser cutting process. At the end of the research it was possible to elaborate a preliminary proposal concerning a laser based dismantling system for the application to a typical Nuclear Power Station. (author)

Cutting agents for special metals

International Nuclear Information System (INIS)

Sugito, Seiji; Sakakibara, Fumi

1979-01-01

The quantity of use of special metals has increased year after year in the Plasma Research Institute, Nagoya University, with the development of researches on plasma and nuclear fusion. Most of these special metals are hard to cut, and in order to secure the surface smoothness and dimensional accuracy, considerable efforts are required. The method of experiment is as follows: cutting agents salt water and acetone, rape-seed oil, sulfide and chloride oil and water soluble cutting oil W grade 3; metals to be cut niobium, molybdenum, tantalum, titanium and tungsten; cutting conditions cutting speed 4.7 to 90 m/min, feed 0.07 to 0.2 mm/rev, depth of cut 0.1 to 0.4 mm, tool cemented carbide bit. Chemicals such as tetrachloromethane and trichloroethane give excellent cutting performance, but the toxicity is intense and the stimulative odor exists, accordingly they are hard to use practically. Cutting was easier when the salt water added with acetone was used than the case of rape-seed oil, but salt water is corrosive. Recently, the machining of molybdenum has been often carried out, and the water soluble cutting oil was the best. It is also good for cutting stainless steel, and its lubricating property is improved by adding some additives such as sulfur, chlorine, phosphorus and molybdenum disulfide. However after cutting with it, washing is required. (Kako, I.)

Performance Testing of Cutting Fluids

DEFF Research Database (Denmark)

Belluco, Walter

The importance of cutting fluid performance testing has increased with documentation requirements of new cutting fluid formulations based on more sustainable products, as well as cutting with minimum quantity of lubrication and dry cutting. Two sub-problems have to be solved: i) which machining...... tests feature repeatability, reproducibility and sensitivity to cutting fluids, and ii) to what extent results of one test ensure relevance to a wider set of machining situations. The present work is aimed at assessing the range of validity of the different testing methods, investigating correlation...... within the whole range of operations, materials, cutting fluids, operating conditions, etc. Cutting fluid performance was evaluated in turning, drilling, reaming and tapping, and with respect to tool life, cutting forces, chip formation and product quality (dimensional accuracy and surface integrity...

Gribov's reggeon calculus: its physical basis and implications

International Nuclear Information System (INIS)

Baker, M.; Ter-Martirosyan, K.A.

1976-01-01

The equations of Gribov's Reggeon calculus and the cutting rules of Abramovskii, Gribov and Kancheli are derived from the assumption that processes involving large virtual masses are damped. The discussion is carried out entirely in the s channel and no use is made of the details of any particular field theory. Both the mathematical development and the physical picture which evolves rest on the assumed multiperipheral origin of Regge behavior. (Auth.)

Female genital cutting.

Science.gov (United States)

Perron, Liette; Senikas, Vyta; Burnett, Margaret; Davis, Victoria

2013-11-01

To strengthen the national framework for care of adolescents and women affected by female genital cutting (FGC) in Canada by providing health care professionals with: (1) information intended to strengthen their knowledge and understanding of the practice; (2) directions with regard to the legal issues related to the practice; (3) clinical guidelines for the management of obstetric and gynaecological care, including FGC related complications; and (4) guidance on the provision of culturally competent care to adolescents and women with FGC. Published literature was retrieved through searches of PubMed, CINAHL, and The Cochrane Library in September 2010 using appropriate controlled vocabulary (e.g., Circumcision, Female) and keywords (e.g., female genital mutilation, clitoridectomy, infibulation). We also searched Social Science Abstracts, Sociological Abstracts, Gender Studies Database, and ProQuest Dissertations and Theses in 2010 and 2011. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to December 2011. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Summary Statements 1. Female genital cutting is internationally recognized as a harmful practice and a violation of girls' and women's rights to life, physical integrity, and health. (II-3) 2. The immediate and long-term health risks and complications of female genital cutting can be serious and life threatening. (II-3) 3. Female genital cutting continues to be practised in many countries, particularly in sub-Saharan Africa, Egypt, and Sudan. (II-3) 4. Global migration

Remotely controlled cutting techniques in the field of nuclear decommissioning. Overview of effectively applied thermal cutting methods

International Nuclear Information System (INIS)

Bienia, H.; Klotz, B.

2008-01-01

This article describes 3 thermal cutting technologies that are effectively used in nuclear decommissioning projects: the autonomous flame cutting, the plasma arc cutting and the contact arc metal cutting. The autonomous flame cutting technology is based on a high pressure oxygen jet oxidizing the material in a small kerf. Not all metal types are appropriate for this technology. The plasma arc cutting, in contrast to the previous technology, uses an electronically induced plasma arc to melt a kerf in the material. Inside the plasma arc temperatures up to 30.000 K exist, so in theory, this temperature is sufficient to cut all materials. Contact arc metal cutting is a new thermal cutting technology for under-water cutting works. Here, a carbon blade cuts the components. An electric arc between the cutting blade and component melts a kerf into the material easing the cutting. This technology allows the cutting of complex structures with hollows. The applications in nuclear facility dismantling of these 3 cutting technologies and their limits are reported and their requirements (staff, investment) listed in a table. (A.C.)

Extension without Cut

OpenAIRE

Straßburger , Lutz

2012-01-01

International audience; In proof theory one distinguishes sequent proofs with cut and cut-free sequent proofs, while for proof complexity one distinguishes Frege-systems and extended Frege-systems. In this paper we show how deep inference can provide a uniform treatment for both classifications, such that we can define cut-free systems with extension, which is neither possible with Frege-systems, nor with the sequent calculus. We show that the propositional pigeon-hole principle admits polyno...

Aerodynamic Interactions During Laser Cutting

Science.gov (United States)

Fieret, J.; Terry, M. J.; Ward, B. A.

1986-11-01

Most laser cutting systems utilise a gas jet to remove molten or vaporised material from the kerf. The speed, economy and quality of the cut can be strongly dependent on the aerodynamic conditions created by the nozzle, workpiece proximity and kerf shape. Adverse conditions can be established that may lead to an unwelcome lack of reproducibility of cut quality. Relatively low gas nozzle pressures can result in supersonic flow in the jet with its associated shock fronts. When the nozzle is placed at conventional distances (1-2mm) above the workpiece, the force exerted by the gas on the workpiece and the cut products (the cutting pressure) can be significantly less than the nozzle pressure. Higher cutting pressures can be achieved by increasing the height of the nozzle above the workpiece, to a more damage resistant zone, provided that the shock structure of the jet is taken into account. Conventional conical nozzles with circular exits can be operated with conditions that will result in cutting pressures up to 3 Bar (g) in the more distant zone. At higher pressures in circular tipped nozzles the cutting pressure in this zone decays to inadequate levels. Investigations of a large number of non-circular nozzle tip shapes have resulted in the selection of a few specific shapes that can provide cutting pressures in excess of 6 Bar(g) at distances of 4 to 7mm from the nozzle tip. Since there is a strong correlation between cutting pressure and the speed and quality of laser cutting, the paper describes the aerodynamic requirements for achieving the above effects and reports the cutting results arising from the different nozzle designs and conditions. The results of the work of other investigators, who report anomalous laser cutting results, will be examined and reviewed in the light of the above work.

Cutting system for burnable poison rod

International Nuclear Information System (INIS)

Shiina, Atsushi; Toyama, Norihide; Koshino, Yasuo; Fujii, Toshio

1989-01-01

Burnable poison rods attached to spent fuels are contained in a containing box and transported to a receiving pool. The burnable poison rod-containing box is provisionally situated by the operation to a handling device to a provisional setting rack in a cutting pool and attached to a cutting guide of a cutting device upon cutting. The burnable poison rod is cut only in a cutting pool water and tritium generated upon cutting is dissolved into the cutting pool water. Diffusion of tritium is thus restricted. Further, the cutting pool is isolated by a partition device from the receiving pool during cutting of the burnable poison rod. Accordingly, water in which tritium is dissolved is inhibited from moving to the receiving pool and prevail of tritium contamination can be avoided. (T.M.)

Theoretical Models for Orthogonal Cutting

DEFF Research Database (Denmark)

De Chiffre, Leonardo

This review of simple models for orthogonal cutting was extracted from: “L. De Chiffre: Metal Cutting Mechanics and Applications, D.Sc. Thesis, Technical University of Denmark, 1990.”......This review of simple models for orthogonal cutting was extracted from: “L. De Chiffre: Metal Cutting Mechanics and Applications, D.Sc. Thesis, Technical University of Denmark, 1990.”...

Laser circular cutting of Kevlar sheets: Analysis of thermal stress filed and assessment of cutting geometry

Science.gov (United States)

Yilbas, B. S.; Akhtar, S. S.; Karatas, C.

2017-11-01

A Kevlar laminate has negative thermal expansion coefficient, which makes it difficult to machine at room temperaures using the conventional cutting tools. Contararily, laser machining of a Kevlar laminate provides advantages over the conventional methods because of the non-mechanical contact between the cutting tool and the workpiece. In the present study, laser circular cutting of Kevlar laminate is considered. The experiment is carried out to examine and evaluate the cutting sections. Temperature and stress fields formed in the cutting section are simulated in line with the experimental study. The influence of hole diameters on temperature and stress fields are investigated incorporating two different hole diameters. It is found that the Kevlar laminate cutting section is free from large size asperities such as large scale sideways burnings and attachemnt of charred residues. The maximum temperature along the cutting circumference remains higher for the large diameter hole than that of the small diameter hole. Temperature decay is sharp around the cutting section in the region where the cutting terminates. This, in turn, results in high temperature gradients and the thermal strain in the cutting region. von Mises stress remains high in the region where temperature gradients are high. von Mises stress follows similar to the trend of temperature decay around the cutting edges.

A study of estimating cutting depth for multi-pass nanoscale cutting by using atomic force microscopy

International Nuclear Information System (INIS)

Lin, Zone-Ching; Hsu, Ying-Chih

2012-01-01

This paper studies two models for estimating cutting depth of multi-pass nanoscale cutting by using an atomic force microscopy (AFM) probe. One estimates cutting depth for multi-pass nanoscale cutting by using regression equations of nanoscale contact pressure factor (NCP factor) while the other uses equation of specific down force energy (SDFE). This paper proposes taking a diamond-coated probe of AFM as the cutting tool to carry out multi-pass nanoscale cutting experiments on the surface of sapphire substrate. In the process of experimentation, different down forces are set, and the probe shape of AFM is known, then using each down force to multi-pass cutting the sapphire substrate. From the measured experimental data of a central cutting depth of the machining groove by AFM, this paper calculates the specific down force energy of each down force. The experiment results reveal that the specific down force energy of each case of multi-pass nanoscale cutting for different down forces under a probe of AFM is close to a constant value. This paper also compares the nanoscale cutting results from estimating cutting depths for each pass of multi-pass among the experimental results and the calculating results obtained by the two theories models. It is found that the model of specific down force energy can calculate cutting depths for each nanoscale cutting pass by one equation. It is easier to use than the multi-regression equations of the nanoscale contact pressure factor. Besides, the estimations of cutting depth results obtained by the model of specific down force energy are closer to that of the experiment results. It shows that the proposed specific down force energy model in this paper is an acceptable model.

Consumer evaluation of palatability characteristics of a beef value-added cut compared to common retail cuts.

Science.gov (United States)

Lepper-Blilie, A N; Berg, E P; Germolus, A J; Buchanan, D S; Berg, P T

2014-01-01

The objectives of this study were to educate consumers about value-added beef cuts and evaluate their palatability responses of a value cut and three traditional cuts. Three hundred and twenty-two individuals participated in the beef value cut education seminar series presented by trained beef industry educators. Seminar participants evaluated tenderness, juiciness, flavor, and overall like of four samples, bottom round, top sirloin, ribeye, and a value cut (Delmonico or Denver), on a 9-point scale. The ribeye and the value cut were found to be similar in all four attributes and differed from the top sirloin and bottom round. Correlations and regression analysis found that flavor was the largest influencing factor for overall like for the ribeye, value cut, and top sirloin. The value cut is comparable to the ribeye and can be a less expensive replacement. © 2013.

Flux cutting in superconductors

International Nuclear Information System (INIS)

Campbell, A M

2011-01-01

This paper describes experiments and theories of flux cutting in superconductors. The use of the flux line picture in free space is discussed. In superconductors cutting can either be by means of flux at an angle to other layers of flux, as in longitudinal current experiments, or due to shearing of the vortex lattice as in grain boundaries in YBCO. Experiments on longitudinal currents can be interpreted in terms of flux rings penetrating axial lines. More physical models of flux cutting are discussed but all predict much larger flux cutting forces than are observed. Also, cutting is occurring at angles between vortices of about one millidegree which is hard to explain. The double critical state model and its developments are discussed in relation to experiments on crossed and rotating fields. A new experiment suggested by Clem gives more direct information. It shows that an elliptical yield surface of the critical state works well, but none of the theoretical proposals for determining the direction of E are universally applicable. It appears that, as soon as any flux flow takes place, cutting also occurs. The conclusion is that new theories are required. (perspective)

The four-loop remainder function and multi-Regge behavior at NNLLA in planar N=4 super-Yang-Mills theory

Energy Technology Data Exchange (ETDEWEB)

Dixon, Lance J. [SLAC National Accelerator Laboratory,Stanford University, Stanford, CA 94309 (United States); Drummond, James M. [CERN,Geneva 23 (Switzerland); School of Physics and Astronomy, University of Southampton,Highfield, Southampton, SO17 1BJ (United Kingdom); LAPTH, CNRS et Université de Savoie,F-74941 Annecy-le-Vieux Cedex (France); Duhr, Claude [Institute for Particle Physics Phenomenology, University of Durham,Durham, DH1 3LE (United Kingdom); Pennington, Jeffrey [SLAC National Accelerator Laboratory,Stanford University, Stanford, CA 94309 (United States)

2014-06-19

We present the four-loop remainder function for six-gluon scattering with maximal helicity violation in planar N=4 super-Yang-Mills theory, as an analytic function of three dual-conformal cross ratios. The function is constructed entirely from its analytic properties, without ever inspecting any multi-loop integrand. We employ the same approach used at three loops, writing an ansatz in terms of hexagon functions, and fixing coefficients in the ansatz using the multi-Regge limit and the operator product expansion in the near-collinear limit. We express the result in terms of multiple polylogarithms, and in terms of the coproduct for the associated Hopf algebra. From the remainder function, we extract the BFKL eigenvalue at next-to-next-to-leading logarithmic accuracy (NNLLA), and the impact factor at N{sup 3}LLA. We plot the remainder function along various lines and on one surface, studying ratios of successive loop orders. As seen previously through three loops, these ratios are surprisingly constant over large regions in the space of cross ratios, and they are not far from the value expected at asymptotically large orders of perturbation theory.

Development of underwater laser cutting technology

International Nuclear Information System (INIS)

Sato, Seiichi; Inaba, Takanori; Inose, Koutarou; Matsumoto, Naoyuki; Sakakibara, Yuji

2015-01-01

In is desirable to use remote underwater device for the decommissioning work of highly radioactive components such as the nuclear internals from a view point of reducing the ranitidine exposure to the worker. Underwater laser cutting technology has advantages. First advantage in underwater laser cutting technology is that low reaction force during cutting, namely, remote operability is superior. Second point is that underwater laser cutting generates a little amount of secondary waste, because cutting kerf size is very small. Third point is that underwater laser cutting has low risk of the process delay, because device trouble is hard to happen. While underwater laser cutting has many advantages, the careful consideration in the safe treatment of the offgas which underwater laser cutting generates is necessary. This paper describes outline of underwater laser cutting technology developed by IHI Corporation (IHI) and that this technology is effective in various dismantling works in water. (author)

Cutting temperature measurement and material machinability

Directory of Open Access Journals (Sweden)

Nedić Bogdan P.

2014-01-01

Full Text Available Cutting temperature is very important parameter of cutting process. Around 90% of heat generated during cutting process is then away by sawdust, and the rest is transferred to the tool and workpiece. In this research cutting temperature was measured with artificial thermocouples and question of investigation of metal machinability from aspect of cutting temperature was analyzed. For investigation of material machinability during turning artificial thermocouple was placed just below the cutting top of insert, and for drilling thermocouples were placed through screw holes on the face surface. In this way was obtained simple, reliable, economic and accurate method for investigation of cutting machinability.

Stresses in ultrasonically assisted bone cutting

International Nuclear Information System (INIS)

Alam, K; Mitrofanov, A V; Silberschmidt, V V; Baeker, M

2009-01-01

Bone cutting is a frequently used procedure in the orthopaedic surgery. Modern cutting techniques, such as ultrasonic assisted drilling, enable surgeons to perform precision operations in facial and spinal surgeries. Advanced understanding of the mechanics of bone cutting assisted by ultrasonic vibration is required to minimise bone fractures and to optimise the technique performance. The paper presents results of finite element simulations on ultrasonic and conventional bone cutting analysing the effects of ultrasonic vibration on cutting forces and stress distribution. The developed model is used to study the effects of cutting and vibration parameters (e.g. amplitude and frequency) on the stress distributions in the cutting region.

Optimisation Of Cutting Parameters Of Composite Material Laser Cutting Process By Taguchi Method

Science.gov (United States)

Lokesh, S.; Niresh, J.; Neelakrishnan, S.; Rahul, S. P. Deepak

2018-03-01

The aim of this work is to develop a laser cutting process model that can predict the relationship between the process input parameters and resultant surface roughness, kerf width characteristics. The research conduct is based on the Design of Experiment (DOE) analysis. Response Surface Methodology (RSM) is used in this work. It is one of the most practical and most effective techniques to develop a process model. Even though RSM has been used for the optimization of the laser process, this research investigates laser cutting of materials like Composite wood (veneer)to be best circumstances of laser cutting using RSM process. The input parameters evaluated are focal length, power supply and cutting speed, the output responses being kerf width, surface roughness, temperature. To efficiently optimize and customize the kerf width and surface roughness characteristics, a machine laser cutting process model using Taguchi L9 orthogonal methodology was proposed.

Selection of Near Optimal Laser Cutting Parameters in CO2 Laser Cutting by the Taguchi Method

Directory of Open Access Journals (Sweden)

Miloš MADIĆ

2013-12-01

Full Text Available Identification of laser cutting conditions that are insensitive to parameter variations and noise is of great importance. This paper demonstrates the application of Taguchi method for optimization of surface roughness in CO2 laser cutting of stainless steel. The laser cutting experiment was planned and conducted according to the Taguchi’s experimental design using the L27 orthogonal array. Four laser cutting parameters such as laser power, cutting speed, assist gas pressure, and focus position were considered in the experiment. Using the analysis of means and analysis of variance, the significant laser cutting parameters were identified, and subsequently the optimal combination of laser cutting parameter levels was determined. The results showed that the cutting speed is the most significant parameter affecting the surface roughness whereas the influence of the assist gas pressure can be neglected. It was observed, however, that interaction effects have predominant influence over the main effects on the surface roughness.

How Can I Stop Cutting?

Science.gov (United States)

... Educators Search English Español How Can I Stop Cutting? KidsHealth / For Teens / How Can I Stop Cutting? ... in a soft, cozy blanket Substitutes for the Cutting Sensation You'll notice that all the tips ...

Rooting of stem cuttings of ixora

Directory of Open Access Journals (Sweden)

Aline De Souza Silva

2015-08-01

Full Text Available The ixora is ornamental plant widely used in landscaping. In order to maximize the propagation of cuts, we evaluated the concentrations of auxin (indolbutiric acid and the presence of leaves on the rooting in cuts of Ixora coccinea L. The experiment was conducted in randomized block design, in factorial design 3x4, with three types of cuts (without leaf, with two or four leaves, four concentrations of indolbutiric acid (0, 1000, 2000 and 4000 mg L-1, with four replications and 10 cuts in each experimental unit. After 53 days of implantation the experiment, evaluated the survival(%, rooting(%, sprouting(%, formation of callus(%, number, length and biomass of roots formed. The interaction of the type of cuts with concentrations of auxin was not significant for any of the variables analyzed. The survival of cuttings was not influenced by the treatments. Cuts with two or four leaves presented rooting and length of roots above the cuttings without leaves. The application of auxin does not substitute the presence of leaf in cuts of ixora in vegetative propagation. The vegetative propagation by cut of ixora can be made without application of auxin, and the leaves must be maintained in the cuttings.

Development of lathe tool dynamometer and finding cutting forces using negative and positive rake angle cutting tool

International Nuclear Information System (INIS)

Zeb, M.A.; Irfan, M.A.

2005-01-01

Most output parameters in machining, such as cutting forces, temperatures, strains and the work-hardening of the chip material, are directly related to the chip formation process. The characteristics of machining processes can be well understood if the forces and strains during chip formation are known. In this research a lathe tool dynamometer was used to measure cutting forces involved in machining of Steel 1045 and Aluminum 2219 T62. High Speed Steel (HSS), cutting tools with positive and negative rake angles were used. It was observed that more cutting forces are experienced by the cutting tool with positive rake angle as compared to the forces experienced by the cutting tool with negative rake angle. For steel 1045 the cutting forces using positive rake angle cutting tool were much higher. This suggested that for harder materials using a negative rake angle is more suitable for cutting. (author)

Investigation of Physical Phenomena and Cutting Efficiency for Laser Cutting on Anode for Li-Ion Batteries

Directory of Open Access Journals (Sweden)

Dongkyoung Lee

2018-02-01

Full Text Available Lithium-ion batteries have a higher energy density than other secondary batteries. Among the lithium-ion battery manufacturing process, electrode cutting is one of the most important processes since poor cut quality leads to performance degradation, separator protrusion, and local electric stress concentration. This may, eventually, lead to malfunction of lithium-ion batteries or explosion. The current mechanical cutting technology uses a contact process and this may lead to process instability. Furthermore, there are additional costs if the tools and cell design are changed. To solve these issues, laser cutting has been used. Conventional dependent parameters have limitations in investigating and explaining many physical phenomena during the laser cutting of electrodes. Therefore, this study proposes specific widths such as melting, top, and kerf width. Moreover, the relationship between laser parameters and multiphysical phenomena with the proposed widths are investigated. Five types of classification with regard to physical phenomena are presented and explained with SEM images. Cutting efficiency is estimated with the proposed widths. The proposed specific cutting widths, five types of geometrical classification, and cutting efficiency can be used as standardized parameters to evaluate the cutting quality.

CALCULATION OF LASER CUTTING COSTS

OpenAIRE

Bogdan Nedic; Milan Eric; Marijana Aleksijevic

2016-01-01

The paper presents description methods of metal cutting and calculation of treatment costs based on model that is developed on Faculty of mechanical engineering in Kragujevac. Based on systematization and analysis of large number of calculation models of cutting with unconventional methods, mathematical model is derived, which is used for creating a software for calculation costs of metal cutting. Software solution enables resolving the problem of calculating the cost of laser cutting, compar...

Method of cutting radioactivated metal structures

International Nuclear Information System (INIS)

Takimoto, Yoshinori; Sakota, Kotaro; Hamamoto, Noboru; Harada, Keizo.

1985-01-01

Purpose: To improve the cutting performance to a level as comparable with that in air, as well as prevent the scattering of the radioactive materials upon cutting to the level as that in water cutting. Method: After igniting a gas cutting torch automatically, water spray by the local water sprayer is started by the actuation of a submerged pump, while a gas cutting manipulator is operated to cut the nuclear reactor pressure vessel. In this way, cutting exhaust gases resulted from the gas cutting torch are water-washed by the spray from the local water sprayer and falls within the nuclear rector pressure vessel in the form of water streams or droplets along the inner wall surface of the pressure vessel. Further, water is fed again to the local water sprayer by the submerged pump. (Kawakami, Y.)

Laser Cutting of Thin Nickel Bellows

Science.gov (United States)

Butler, C. L.

1986-01-01

Laser cutting technique produces narrow, precise, fast, and repeatable cuts in thin nickel-allow bellows material. Laser cutting operation uses intense focused beam to melt material and assisting gas to force melted material through part thickness, creating void. When part rotated or moved longitudinally, melting and material removal continuous and creates narrow, fast, precise, and repeatable cut. Technique used to produce cuts of specified depths less than material thickness. Avoids distortion, dents, and nicks produced in delicate materials during lathe trimming operations, which require high cutting-tool pressure and holding-fixture forces.

Experimental improvement of the technology of cutting of high-pressure hoses with metal braid on hand cutting machine

OpenAIRE

Karpenko, Mykola; Bogdevicius, Marijonas; Prentkovskis, Olegas

2016-01-01

In the article the review of the problem of improvement of technology of high pressure hoses cutting on the hand cutting machines is analyzed. Different methods of cutting of high pressure hoses into the billets are overviewed and the quality of edge cuts of hoses is analyzed. The comparison of treatment on automatic cutting machines and on hand cutting machines is carried out. Different experimental techniques of improvement of the quality of edges cutting of high pressure hoses are prese...

Laser cutting of various materials: Kerf width size analysis and life cycle assessment of cutting process

Science.gov (United States)

Yilbas, Bekir Sami; Shaukat, Mian Mobeen; Ashraf, Farhan

2017-08-01

Laser cutting of various materials including Ti-6Al-4V alloy, steel 304, Inconel 625, and alumina is carried out to assess the kerf width size variation along the cut section. The life cycle assessment is carried out to determine the environmental impact of the laser cutting in terms of the material waste during the cutting process. The kerf width size is formulated and predicted using the lump parameter analysis and it is measured from the experiments. The influence of laser output power and laser cutting speed on the kerf width size variation is analyzed using the analytical tools including scanning electron and optical microscopes. In the experiments, high pressure nitrogen assisting gas is used to prevent oxidation reactions in the cutting section. It is found that the kerf width size predicted from the lump parameter analysis agrees well with the experimental data. The kerf width size variation increases with increasing laser output power. However, this behavior reverses with increasing laser cutting speed. The life cycle assessment reveals that material selection for laser cutting is critical for the environmental protection point of view. Inconel 625 contributes the most to the environmental damages; however, recycling of the waste of the laser cutting reduces this contribution.

ADVANCED CUTTINGS TRANSPORT STUDY

Energy Technology Data Exchange (ETDEWEB)

Stefan Miska; Troy Reed; Ergun Kuru

2004-09-30

The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation system. In parallel with the flow loop construction, hydraulics and cuttings transport studies were preformed using drilling foams and aerated muds. In addition, hydraulics and rheology of synthetic drilling fluids were investigated. The studies were performed under ambient and EPET conditions. The effects of temperature and pressure on the hydraulics and cuttings transport were investigated. Mechanistic models were developed to predict frictional pressure loss and cuttings transport in horizontal and near-horizontal configurations. Model predictions were compared with the measured data. Predominantly, model predictions show satisfactory agreements with the measured data. As a

Practical side of cutting. Part 3. ; CO2 laser cutting. Setsudan gijutsu no jissai. 3. ; Laser setsudan

Energy Technology Data Exchange (ETDEWEB)

Miyazaki, T.; Shinonaga, H. (Toshiba Corp., Tokyo (Japan))

1993-03-05

The nature peculiar to laser beam makes it difficult to understand the phenomena in laser cutting. Quoting an example of cutting steel materials, practical minimum basic subjects, factors governing the cutting phenomena with points to be considered, and the current state of the technology are outlined. Various kinds of expert systems and automatic programming devices have been placed on the market to make NC input easier in laser cutting. Shape accuracy, cutting quality, cutting speed, applicable plate thickness, etc. are among the subjects required for laser cutting. The factors are the method of scanning, characteristics of laser beam, work, machining conditions, etc. The factors obstructing stable processing are the change in the ambient temperature, humidity, dust, oil mist, vibration, etc. The basic factors which control the laser cutting are the power density and its distribution at the working point. Pulse cutting is employed when continuous laser heat input is not appropriate. Summarized report is made on the focal point and assist gas. 16 refs., 9 figs., 1 tab.

Cutting Cosmos

DEFF Research Database (Denmark)

Mikkelsen, Henrik Hvenegaard

For the first time in over 30 years, a new ethnographic study emerges on the Bugkalot tribe, more widely known as the Ilongot of the northern Philippines. Exploring the notion of masculinity among the Bugkalot, Cutting Cosmos is not only an experimental, anthropological study of the paradoxes...... around which Bugkalot society revolves, but also a reflection on anthropological theory and writing. Focusing on the transgressive acts through which masculinity is performed, this book explores the idea of the cosmic cut, the ritual act that enables the Bugkalot man to momentarily hold still the chaotic...

Latest development of laser cutting

OpenAIRE

Wetzig, Andreas; Herwig, Patrick; Hauptmann, Jan; Goppold, Cindy; Baumann, Robert; Fürst, Andreas; Rose, Michael; Pinder, Thomas; Mahrle, Achim; Beyer, Eckhard

2016-01-01

Laser cutting was one of the first applications of laser material processing. Today, laser cutting is the most widespread application among laser material processing besides laser marking. Meanwhile, nearly each material can be cut by means of a laser, in particular since ultra short pulse lasers are available in the power range of up to 100 W. The to be cut material can come with thicknesses from a few microns till tens of millimeters as flat stock or as free form shapes. The paper will conc...

CALCULATION OF LASER CUTTING COSTS

Directory of Open Access Journals (Sweden)

Bogdan Nedic

2016-09-01

Full Text Available The paper presents description methods of metal cutting and calculation of treatment costs based on model that is developed on Faculty of mechanical engineering in Kragujevac. Based on systematization and analysis of large number of calculation models of cutting with unconventional methods, mathematical model is derived, which is used for creating a software for calculation costs of metal cutting. Software solution enables resolving the problem of calculating the cost of laser cutting, comparison' of costs made by other unconventional methods and provides documentation that consists of reports on estimated costs.

Tubing and cable cutting tool

Science.gov (United States)

Mcsmith, D. D.; Richardson, J. I. (Inventor)

1984-01-01

A hand held hydraulic cutting tool was developed which is particularly useful in deactivating ejection seats in military aircraft rescue operations. The tool consists primarily of a hydraulic system composed of a fluid reservoir, a pumping piston, and an actuator piston. Mechanical cutting jaws are attached to the actuator piston rod. The hydraulic system is controlled by a pump handle. As the pump handle is operated the actuator piston rod is forced outward and thus the cutting jaws are forced together. The frame of the device is a flexible metal tubing which permits easy positioning of the tool cutting jaws in remote and normally inaccessible locations. Bifurcated cutting edges ensure removal of a section of the tubing or cable to thereby reduce the possibility of accidental reactivation of the tubing or cable being severed.

Cutting concrete with abrasion jet

International Nuclear Information System (INIS)

Yie, G.G.

1982-01-01

Fluidyne Corporation has developed a unique process and apparatus that allow selected abrasives to be introduced into high-speed waterjet to produce abrasive-entrained waterjet that has high material-cutting capabilities, which is termed by Fluidyne as the Abrasion Jet. Such Abrasion Jet has demonstrated capability in cutting hard rock and concrete at a modest pressure of less than 1360 bars (20,000 psi) and a power input of less than 45 kW (60 horsepower). Abrasion Jet cutting of concrete is characterized by its high rate of cutting, flexible operation, good cut quality, and relatively low costs. This paper presents a general description of this technology together with discussions of recent test results and how it could be applied to nuclear decontamination and decommissioning work. 8 references

Influence of cutting parameters on the depth of subsurface deformed layer in nano-cutting process of single crystal copper.

Science.gov (United States)

Wang, Quanlong; Bai, Qingshun; Chen, Jiaxuan; Su, Hao; Wang, Zhiguo; Xie, Wenkun

2015-12-01

Large-scale molecular dynamics simulation is performed to study the nano-cutting process of single crystal copper realized by single-point diamond cutting tool in this paper. The centro-symmetry parameter is adopted to characterize the subsurface deformed layers and the distribution and evolution of the subsurface defect structures. Three-dimensional visualization and measurement technology are used to measure the depth of the subsurface deformed layers. The influence of cutting speed, cutting depth, cutting direction, and crystallographic orientation on the depth of subsurface deformed layers is systematically investigated. The results show that a lot of defect structures are formed in the subsurface of workpiece during nano-cutting process, for instance, stair-rod dislocations, stacking fault tetrahedron, atomic clusters, vacancy defects, point defects. In the process of nano-cutting, the depth of subsurface deformed layers increases with the cutting distance at the beginning, then decreases at stable cutting process, and basically remains unchanged when the cutting distance reaches up to 24 nm. The depth of subsurface deformed layers decreases with the increase in cutting speed between 50 and 300 m/s. The depth of subsurface deformed layer increases with cutting depth, proportionally, and basically remains unchanged when the cutting depth reaches over 6 nm.

ADVANCED CUTTINGS TRANSPORT STUDY

Energy Technology Data Exchange (ETDEWEB)

Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mengjiao Yu; Ramadan Ahmed; Mark Pickell; Len Volk; Lei Zhou; Zhu Chen; Aimee Washington; Crystal Redden

2003-09-30

The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.

Using internally cooled cutting tools in the machining of difficult-to-cut materials based on Waspaloy

Directory of Open Access Journals (Sweden)

Yahya Isik

2016-05-01

Full Text Available Nickel-based superalloys such as Waspaloy are used for engine components and in the nuclear industry, where considerable strength and corrosion resistance at high operating temperatures are called for. These characteristics of such alloys cause increases in cutting temperature and resultant tool damage, even at low cutting speeds and low feed rates. Thus, they are classified as difficult-to-cut materials. This article presents a cooling method to be used in metal cutting based on a tool holder with a closed internal cooling system with cooling fluid circulating inside. Hence, a green cooling method that does not harm the environment and is efficient in removing heat from the cutting zone was developed. A series of cutting experiments were conducted to investigate the practicality and effectiveness of the internally cooled tool model. The developed system achieved up to 13% better surface quality than with dry machining, and tool life was extended by 12%. The results clearly showed that with the reduced cutting temperature of the internal cooling, it was possible to control the temperature and thus prevent reaching the critical cutting temperature during the turning process, which is vitally important in extending tool life during the processing of Waspaloy.

Laser Cutting, Development Trends

DEFF Research Database (Denmark)

Olsen, Flemming Ove

1999-01-01

In this paper a short review of the development trends in laser cutting will be given.The technology, which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal, as it will expand in heavy industry and in cutting...... of 3-dimensional shapes.The CO2-laser will also in the near future be the dominating laser source in the market, although the new developments in ND-YAG-lasers opens for new possibilities for this laser type....

Water-Cut Sensor System

KAUST Repository

Karimi, Muhammad Akram; Shamim, Atif; Arsalan, Muhammad

2018-01-01

Provided in some embodiments is a method of manufacturing a pipe conformable water-cut sensors system. Provided in some embodiments is method for manufacturing a water-cut sensor system that includes providing a helical T-resonator, a helical ground

Effects of cutting and maturity on antioxidant activity of fresh-cut tomatoes

NARCIS (Netherlands)

Moreira Lana, M.; Tijskens, L.M.M.; Kooten, van O.

2005-01-01

To investigate the changes in total antioxidant activity of fresh-cut tomato during storage, tomato fruits harvested at three different stages of maturity were cut into 7-mm thick slices and stored at 5°C. Intact (control) fruits were stored in the same conditions. The antioxidant activity was

Quality Analysis of Cutting Steel Using Laser

Directory of Open Access Journals (Sweden)

Vladislav Markovič

2013-02-01

Full Text Available The article explores the quality dependence of the edge surface of steel C45 LST EN 10083-1 obtained cutting the material using laser on different cutting regimes and variations in the thickness of trial steel. The paper presents the influence of the main modes of laser cutting equipment Trulaser 3030, including cutting speed, pressure, angle and the thickness of the surface on the quality characteristics of the sample. The quality of the edge after laser cutting is the most important indicator influencing such technological spread in industry worldwide. Laser cutting is the most popular method of material cutting. Therefore, the article focuses on cutting equipment, cutting defects and methods of analysis. Research on microstructure, roughness and micro-toughness has been performed with reference to edge samples. At the end of the publication, conclusions are drawn.Article in Lithuanian

Quality Analysis of Cutting Steel Using Laser

Directory of Open Access Journals (Sweden)

Vladislav Markovič

2012-12-01

Full Text Available The article explores the quality dependence of the edge surface of steel C45 LST EN 10083-1 obtained cutting the material using laser on different cutting regimes and variations in the thickness of trial steel. The paper presents the influence of the main modes of laser cutting equipment Trulaser 3030, including cutting speed, pressure, angle and the thickness of the surface on the quality characteristics of the sample. The quality of the edge after laser cutting is the most important indicator influencing such technological spread in industry worldwide. Laser cutting is the most popular method of material cutting. Therefore, the article focuses on cutting equipment, cutting defects and methods of analysis. Research on microstructure, roughness and micro-toughness has been performed with reference to edge samples. At the end of the publication, conclusions are drawn.Article in Lithuanian

Effect of cutting medium temperatures on rooting process and root primordium differentiation of hardwood cuttings of tetraploid robinia pseudoacacia cutting medium temperatures of tetraploid robinia pseudoacacia

International Nuclear Information System (INIS)

Ling, W.X.; Jine, Q.; Zhong, Z.

2014-01-01

In this study, to examine the effect of heat treatment on the rooting and root development of hardwood cuttings of the tetraploid Robinia pseudoacacia, cuttings of 1-year-old stems were taken from 3-year-old mother trees and treated with IBA solution (1000 mg/L) for 6 h, with water was as a control. Treated cuttings were rooted in heated or unheated nursery beds. Samples were collected on day ten after planting, and then for every five days. The bases of the cuttings were embedded in paraffin and sectioned before being examined under a microscope to determine whether there had been any morphological changes. We found no root primordia in the tissues of the hardwood cuttings of the tetraploid Robinia pseudoacacia before cutting. In the heated bed, adventitious roots originated from callus tissue and the junction between the pith rays and cortical parenchyma cells, and in the unheated bed, adventitious roots originated only from callus tissue. The rooting process involved callus formation, adventitious root formation and elongation; rooting occurred 5-7 days earlier in the heated cuttings than in the unheated ones, and rooting rates were significantly higher in the former 30 days and 50 days after cutting; the minimum effective accumulated temperatures for these three stages were 109.25 degree C, 211.68 degree C and 301.38 degree C, respectively. Our results revealed that heating the soil can promote adventitious root formation, speed up the rooting rate, and cut the propagation period of the tetraploid Robinia pseudoacacia. (author)

New Modelling Strategies For Metal Cutting

International Nuclear Information System (INIS)

Rosa, Pedro A. R.; Martins, Paulo A. F.; Atkins, Anthony G.

2007-01-01

This paper draws from the 'plasticity and friction only' view of metal cutting to the presentation of new modelling strategies based on the interaction between finite elements and modern ductile fracture mechanics. The overall presentation is supported by specially designed orthogonal metal cutting experiments that were performed on Lead test specimens under laboratory-controlled conditions. Comparisons between theoretical predictions and experimental results comprise a wide range of topics such as material flow, cutting forces and specific cutting pressure. The paper demonstrates that while material flow and chip formation can be successfully modelled by traditional 'plasticity and friction only' analyses, the contribution of the fracture work involved in the formation of new surfaces is essential for obtaining good estimates of cutting forces and of the specific cutting pressure

Cutting method and device underwater

International Nuclear Information System (INIS)

Takano, Genta; Kamei, Hiromasa; Beppu, Seiji

1998-01-01

A place of material to be cut is surrounded by an openable/closable box. The material to be cut is cut underwater, and materials generated in this case are removed from the cut portion by a pressurized water jet. The removed materials are sucked and recovered together with water in the box. Among the materials caused by the cutting underwater, solid materials not floating on water are caused to stay in the midway of a sucking and recovering channel. A large sucking force might be required for the entire region of the sucking and recovering channel when sucking and recovering large sized solid materials not floating on water, but even large sized materials can be recovered easily according to the present invention since they are recovered after being sucked and stayed in the midway of the sucking and recovering channel. (N.H.)

Cutting zone area and chip morphology in high-speed cutting of titanium alloy Ti-6Al-4V

International Nuclear Information System (INIS)

Ke, Qing Chan; Xu, Daochun; Xiong, Dan Ping

2017-01-01

The titanium alloy Ti-6Al-4V has superior properties but poor machinability, yet is widely used in aerospace and biomedical industries. Chip formation and cutting zone area are important factors that have received limited attention. Thus, we propose a high-speed orthogonal cutting model for serrated chip formation. The high speed orthogonal cutting of Ti-6Al-4V was studied with a cutting speed of 10-160 m/min and a feed of 0.07-0.11 mm/r. Using theoretical models and experimental results, parameters such as chip shape, serration level, slip angle, and shear slip distance were investigated. Cutting zone boundaries (tool-chip contact length, length of shear plane, and critical slip plane) and cutting zone area were obtained. The results showed that discontinuous, long-curling, and continuous chips were formed at low, medium, and high speeds, respectively. Serration level, shear slip distance, and slip angle rose with increasing cutting speed. The length of shear plane, tool-chip contact, and critical slip plane varied subtly with increased cutting speed, and rose noticeably with increased feed. Cutting zone area grew weakly with increased cutting speed, levelling off at high cutting speed; however, it rose noticeably with increased feed. This study furthers our understanding of the shear slip phenomenon and the mechanism of serrated chip formation

Cutting zone area and chip morphology in high-speed cutting of titanium alloy Ti-6Al-4V

Energy Technology Data Exchange (ETDEWEB)

Ke, Qing Chan; Xu, Daochun; Xiong, Dan Ping [School of Technology, Beijing Forestry University, Beijing (China)

2017-01-15

The titanium alloy Ti-6Al-4V has superior properties but poor machinability, yet is widely used in aerospace and biomedical industries. Chip formation and cutting zone area are important factors that have received limited attention. Thus, we propose a high-speed orthogonal cutting model for serrated chip formation. The high speed orthogonal cutting of Ti-6Al-4V was studied with a cutting speed of 10-160 m/min and a feed of 0.07-0.11 mm/r. Using theoretical models and experimental results, parameters such as chip shape, serration level, slip angle, and shear slip distance were investigated. Cutting zone boundaries (tool-chip contact length, length of shear plane, and critical slip plane) and cutting zone area were obtained. The results showed that discontinuous, long-curling, and continuous chips were formed at low, medium, and high speeds, respectively. Serration level, shear slip distance, and slip angle rose with increasing cutting speed. The length of shear plane, tool-chip contact, and critical slip plane varied subtly with increased cutting speed, and rose noticeably with increased feed. Cutting zone area grew weakly with increased cutting speed, levelling off at high cutting speed; however, it rose noticeably with increased feed. This study furthers our understanding of the shear slip phenomenon and the mechanism of serrated chip formation.

Effects of cutting and maturity on antioxidant activity of fresh-cut tomatoes

NARCIS (Netherlands)

Moreira Lana, M.; Tijskens, L.M.M.

2006-01-01

To investigate the changes in total antioxidant activity of fresh-cut tomato during storage, tomato fruits harvested at three different stages of maturity were cut into 7-mm thick slices and stored at 5 °C. Intact fruits were stored in the same conditions as a control. The antioxidant activity was

Respiration rate and ethylene production of fresh cut lettuce as affected by cutting grade

Directory of Open Access Journals (Sweden)

J. MARTÍNEZ

2008-12-01

Full Text Available For designing optimal polymeric films for modified atmosphere packaging of whole heads as well as for minimally fresh processed (fresh-cut Iceberg lettuce ‘Coolguard’, the effect of several cutting grades on respiration rate (RR and ethylene production at 5ºC was studied. According to common industrial practices cutting grades less than 0.5 cm, between 0.5 and 1 cm, and 2 cm length were selected. Results from four experiments were compared to those obtained for whole heads in which a homogenous range of 6 to 8 ml CO2 kg-1 h-1 in RR was found. Compared to whole heads, in fresh-cut lettuce the RR was 2-fold higher. The lowest cutting grade showed the highest respiration rate, and no significant differences in RR among lettuce pieces of intermediate and the highest grades were found. No ethylene production was detected in whole heads, while in minimally processed lettuce pieces only traces were found. For avoiding risks of anaerobic respiration and excessive CO2 levels within packages containing fresh-cut lettuce pieces lower than 0.5 cm length, films with relatively high O2 permeability like standard polypropylene or low-density polyethylene must be selected.;

Test tube systems with cutting/recombination operations

Energy Technology Data Exchange (ETDEWEB)

Freund, R. [Technische Universitaet Wien (Austria); Csuhaj-Varju, E. [Computer and Automation Institute, Budapest (Hungary); Wachtler, F. [Universitaet Wien (Austria)

1996-12-31

We introduce test tube systems based on operations that are closely related to the splicing operations, i.e. we consider the operations of cutting a string at a specific site into two pieces with marking them at the cut ends and of recombining two strings with specifically marked endings. Whereas in the splicing of two strings these strings are cut at specific sites and the cut pieces are recombined immediately in a crosswise way, in CR(cutting/recombination)-schemes cutting can happen independently from recombining the cut pieces. Test tube systems based on these operations of cutting and recombination turn out to have maximal generative power even if only very restricted types of input filters for the test tubes are used for the redistribution of the contents of the test tubes after a period of cuttings and recombinations in the test tubes. 10 refs.

Laser cutting system

Science.gov (United States)

Dougherty, Thomas J

2015-03-03

A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

Trim cut machining and surface integrity analysis of Nimonic 80A alloy using wire cut EDM

Directory of Open Access Journals (Sweden)

Amitesh Goswami

2017-02-01

Full Text Available This present work deals with the features of trim cut wire EDM machining of Nimonic 80A in terms of machining parameters, to predict material removal rate (MRR, surface roughness (Ra, wire wear ratio (WWR and microstructure analysis. Trim cut is performed after rough cut to remove the rough layer deposited after machining due to melting and re-solidification of the eroded metal from workpiece as well as from wire electrode. Taguchi’s design of experiments methodology has been used for planning and designing the experiments. The relative significance of various factors has also been evaluated and analyzed using ANOVA. The results clearly indicate trim cut potential for high surface finish compared to rough cut machining.

Laser Cutting of Carbon Fiber Fabrics

Science.gov (United States)

Fuchs, A. N.; Schoeberl, M.; Tremmer, J.; Zaeh, M. F.

Due to their high weight-specific mechanical stiffness and strength, parts made from carbon fiber reinforced polymers (CFRP) are increasingly used as structural components in the aircraft and automotive industry. However, the cutting of preforms, as with most automated manufacturing processes for CFRP components, has not yet been fully optimized. This paper discusses laser cutting, an alternative method to the mechanical cutting of preforms. Experiments with remote laser cutting and gas assisted laser cutting were carried out in order to identify achievable machining speeds. The advantages of the two different processes as well as their fitness for use in mass production are discussed.

Automated Laser Cutting In Three Dimensions

Science.gov (United States)

Bird, Lisa T.; Yvanovich, Mark A.; Angell, Terry R.; Bishop, Patricia J.; Dai, Weimin; Dobbs, Robert D.; He, Mingli; Minardi, Antonio; Shelton, Bret A.

1995-01-01

Computer-controlled machine-tool system uses laser beam assisted by directed flow of air to cut refractory materials into complex three-dimensional shapes. Velocity, position, and angle of cut varied. In original application, materials in question were thermally insulating thick blankets and tiles used on space shuttle. System shapes tile to concave or convex contours and cuts beveled edges on blanket, without cutting through outer layer of quartz fabric part of blanket. For safety, system entirely enclosed to prevent escape of laser energy. No dust generated during cutting operation - all material vaporized; larger solid chips dislodged from workpiece easily removed later.

Identification and characterization of a novel Cut family cDNA that encodes human copper transporter protein CutC

International Nuclear Information System (INIS)

Li Jixi; Ji Chaoneng; Chen Jinzhong; Yang Zhenxing; Wang Yijing; Fei, Xiangwei; Zheng Mei; Gu Xing; Wen Ge; Xie Yi; Mao Yumin

2005-01-01

Copper is an essential heavy metal trace element that plays important roles in cell physiology. The Cut family was associated with the copper homeostasis and involved in several important metabolisms, such as uptake, storage, delivery, and efflux of copper. In this study, a novel Cut family cDNA was isolated from the human fetal brain library, which encodes a 273 amino acid protein with a molecular mass of about 29.3 kDa and a calculated pI of 8.17. It was named hCutC (human copper transporter protein CutC). The ORF of hCutC gene was cloned into pQE30 vector and expressed in Escherichia coli M15. The secreted hCutC protein was purified to a homogenicity of 95% by using the Ni-NTA affinity chromatography. RT-PCR analysis showed that the hCutC gene expressed extensively in human tissues. Subcellular location analysis of hCutC-EGFP fusion protein revealed that hCutC was distributed to cytoplasm of COS-7 cells, and both cytoplasm and nucleus of AD293 cells. The results suggest that hCutC may be one shuttle protein and play important roles in intracellular copper trafficking

Laser Cutting of Different Materials

Directory of Open Access Journals (Sweden)

Kadir ÇAVDAR

2013-08-01

Full Text Available In this paper; in general potential developments and trends of a particular machining field by extensively evaluating present studies of laser beam machining have been discussed. As it is indicated below, technical literatures have been subsumed under five major headlines: Experimental studies, reviews, optimization researches of the cutting parameters, theoretical modelling studies of laser beam cutting and academic studies relating to laser cutting

Comparative study of 0° X-cut and Y + 36°-cut lithium niobate high-voltage sensing

Science.gov (United States)

Patel, N.; Branch, D. W.; Schamiloglu, E.; Cular, S.

2015-08-01

A comparison study between Y + 36° and 0° X-cut lithium niobate (LiNbO3) was performed to evaluate the influence of crystal cut on the acoustic propagation to realize a piezoelectric high-voltage sensor. The acoustic time-of-flight for each crystal cut was measured when applying direct current (DC), alternating current (AC), and pulsed voltages. Results show that the voltage-induced shift in the acoustic wave propagation time scaled quadratically with voltage for DC and AC voltages applied to X-cut crystals. For the Y + 36° crystal, the voltage-induced shift scales linearly with DC voltages and quadratically with AC voltages. When applying 5 μs voltage pulses to both crystals, the voltage-induced shift scaled linearly with voltage. For the Y + 36° cut, the voltage-induced shift from applying DC voltages ranged from 10 to 54 ps and 35 to 778 ps for AC voltages at 640 V over the frequency range of 100 Hz-100 kHz. Using the same conditions as the Y + 36° cut, the 0° X-cut crystal sensed a shift of 10-273 ps for DC voltages and 189-813 ps for AC voltage application. For 5 μs voltage pulses, the 0° X-cut crystal sensed a voltage induced shift of 0.250-2 ns and the Y + 36°-cut crystal sensed a time shift of 0.115-1.6 ns. This suggests a frequency sensitive response to voltage where the influence of the crystal cut was not a significant contributor under DC, AC, or pulsed voltage conditions. The measured DC data were compared to a 1-D impedance matrix model where the predicted incremental length changed as a function of voltage. When the voltage source error was eliminated through physical modeling from the uncertainty budget, the combined uncertainty of the sensor (within a 95% confidence interval) decreased to 0.0033% using a Y + 36°-cut crystal and 0.0032% using an X-cut crystal for all the voltage conditions used in this experiment.

Optical Cutting Interruption Sensor for Fiber Lasers

Directory of Open Access Journals (Sweden)

Benedikt Adelmann

2015-09-01

Full Text Available We report on an optical sensor system attached to a 4 kW fiber laser cutting machine to detect cutting interruptions. The sensor records the thermal radiation from the process zone with a modified ring mirror and optical filter arrangement, which is placed between the cutting head and the collimator. The process radiation is sensed by a Si and InGaAs diode combination with the detected signals being digitalized with 20 kHz. To demonstrate the function of the sensor, signals arising during fusion cutting of 1 mm stainless steel and mild steel with and without cutting interruptions are evaluated and typical signatures derived. In the recorded signals the piercing process, the laser switch on and switch off point and waiting period are clearly resolved. To identify the cutting interruption, the signals of both Si and InGaAs diodes are high pass filtered and the signal fluctuation ranges being subsequently calculated. Introducing a correction factor, we identify that only in case of a cutting interruption the fluctuation range of the Si diode exceeds the InGaAs diode. This characteristic signature was successfully used to detect 80 cutting interruptions of 83 incomplete cuts (alpha error 3.6% and system recorded no cutting interruption from 110 faultless cuts (beta error of 0. This particularly high detection rate in combination with the easy integration of the sensor, highlight its potential for cutting interruption detection in industrial applications.

Radioactive wear measurements of cutting tools made of metal in cutting aluminium alloys

International Nuclear Information System (INIS)

Frevert, E.

1977-01-01

The possibility of making quick checkings of the inhomogeneities of turning materials with radioactive wear measurements has been tested. After activation analysis of the long-lived radioisotopes of cutting tools made of hard metal a method for loss-free collection of the turnings has been developed. The detection limit of the abrasion is about 10 -8 g, the measuring times are 5-10 minutes. Special radiation protection measures are not necessary. An analysis of the abrasion showed that at the beginning of cutting the amount of cobalt is 6 times higher than in the normal composition of the used cutting tools. (author)

Economic technology of laser cutting

Science.gov (United States)

Fedin, Alexander V.; Shilov, Igor V.; Vassiliev, Vladimir V.; Malov, Dmitri V.; Peskov, Vladimir N.

2000-02-01

The laser cutting of color metals and alloys by a thickness more than 2 mm has significant difficulties due to high reflective ability and large thermal conduction. We made it possible to raise energy efficiency and quality of laser cutting by using a laser processing system (LPS) consisting both of the YAG:Nd laser with passive Q-switching on base of LiF:F2- crystals and the CO2 laser. A distinctive feature of the LPS is that the radiation of different lasers incorporated in a coaxial beam has simultaneously high level of peak power (more than 400 kW in a TEM00 mode) and significant level of average power (up to 800 W in a TEM01 mode of the CO2 laser). The application of combined radiation for cutting of an aluminum alloy of D16 type made it possible to decrease the cutting energy threshold in 1.7 times, to increase depth of treatment from 2 up to 4 mm, and velocity from 0.015 up to 0.7 m/min, and also to eliminate application of absorptive coatings. At cutting of steels the velocity of treatment was doubled, and also an oxygen flow was eliminated from the technological process and replaced by the air. The obtained raise of energy efficiency and quality of cutting is explained by an essential size reducing of a formed penetration channel and by the shifting of a thermal cutting mode from melting to evaporation. The evaluation of interaction efficiency of a combined radiation was produced on the basis of non-stationary thermal-hydrodynamic model of a heating source moving as in the cutting direction, and also into the depth of material.

Development of cutting device for irradiated fuel rod

International Nuclear Information System (INIS)

Lee, E. P.; Jun, Y. B.; Hong, K. P.; Min, D. K.; Lee, H. K.; Su, H. S.; Kim, K. S.; Kwon, H. M.; Joo, Y. S.; Yoo, K. S.; Joo, J. S.; Kim, E. K.

2004-01-01

Post Irradiation Examination(PIE) on irradiated fuel rods is essential for the evaluation of integrity and irradiation performance of fuel rods of commercial reactor fuel. For PIE, fuel rods should be cut very precisely. The cutting positions selected from NDT data are very important for further destructive examination and analysis. A fuel rod cutting device was developed witch can cut fuel rods longitudinal very precisely and can also cut the fuels into the same length rod cuts repeatedly. It is also easy to remove the fuel cutting powder after cutting works and it can extend the life time of cutting device and lower the contamination level of hot cell

ADVANCED CUTTINGS TRANSPORT STUDY

Energy Technology Data Exchange (ETDEWEB)

Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Lei Zhou

2000-01-30

This is the second quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between Oct 1, 2000 and December 31, 2000. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 2: Addition of a foam generation and breaker system), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (d) Research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (e) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (h) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members. The tasks Completed During This Quarter are Task 7 and Task 8.

Submerged cutting characteristics of abrasive suspension jet

International Nuclear Information System (INIS)

Shimizu, Seiji; Peng, Guoyi; Oguma, Yasuyuki; Nishikata, Hiroyuki

2015-01-01

An abrasive suspension jet (ASJ) formed by propelling abrasive suspension through a nozzle has a greater cutting capability than the conventional abrasive water jet. However the cutting capability of submerged ASJs decreases drastically with increasing the standoff distance and the pressure around the jet. A sheathed nozzle with ventilation for ASJs has been developed as a mean of extending the effective stand-off distance and improving the cutting capabilities under submerged condition. In the present investigation, cutting tests by ASJs in air and under submerged condition are conducted with specimens of aluminum alloy. Air coated ASJs are formed by using a sheathed nozzle with ventilation. The relative cutting depth is defined as the cutting depth under submerged condition divided by the cutting depth in air at the same standoff distance. The relative cutting depth is arranged effectually by the cavitation number based on the cavity pressure measured at the sheath. (author)

Effects of Cutting Edge Microgeometry on Residual Stress in Orthogonal Cutting of Inconel 718 by FEM.

Science.gov (United States)

Shen, Qi; Liu, Zhanqiang; Hua, Yang; Zhao, Jinfu; Lv, Woyun; Mohsan, Aziz Ul Hassan

2018-06-14

Service performance of components such as fatigue life are dramatically influenced by the machined surface and subsurface residual stresses. This paper aims at achieving a better understanding of the influence of cutting edge microgeometry on machined surface residual stresses during orthogonal dry cutting of Inconel 718. Numerical and experimental investigations have been conducted in this research. The cutting edge microgeometry factors of average cutting edge radius S¯, form-factor K , and chamfer were investigated. An increasing trend for the magnitudes of both tensile and compressive residual stresses was observed by using larger S¯ or introducing a chamfer on the cutting edges. The ploughing depth has been predicted based on the stagnation zone. The increase of ploughing depth means that more material was ironed on the workpiece subsurface, which resulted in an increase in the compressive residual stress. The thermal loads were leading factors that affected the surface tensile residual stress. For the unsymmetrical honed cutting edge with K = 2, the friction between tool and workpiece and tensile residual stress tended to be high, while for the unsymmetrical honed cutting edge with K = 0.5, the high ploughing depth led to a higher compressive residual stress. This paper provides guidance for regulating machine-induced residual stress by edge preparation.

Quantum Max-flow/Min-cut

Science.gov (United States)

Cui, Shawn X.; Freedman, Michael H.; Sattath, Or; Stong, Richard; Minton, Greg

2016-06-01

The classical max-flow min-cut theorem describes transport through certain idealized classical networks. We consider the quantum analog for tensor networks. By associating an integral capacity to each edge and a tensor to each vertex in a flow network, we can also interpret it as a tensor network and, more specifically, as a linear map from the input space to the output space. The quantum max-flow is defined to be the maximal rank of this linear map over all choices of tensors. The quantum min-cut is defined to be the minimum product of the capacities of edges over all cuts of the tensor network. We show that unlike the classical case, the quantum max-flow=min-cut conjecture is not true in general. Under certain conditions, e.g., when the capacity on each edge is some power of a fixed integer, the quantum max-flow is proved to equal the quantum min-cut. However, concrete examples are also provided where the equality does not hold. We also found connections of quantum max-flow/min-cut with entropy of entanglement and the quantum satisfiability problem. We speculate that the phenomena revealed may be of interest both in spin systems in condensed matter and in quantum gravity.

Quantum Max-flow/Min-cut

Energy Technology Data Exchange (ETDEWEB)

Cui, Shawn X., E-mail: xingshan@math.ucsb.edu [Department of Mathematics, University of California, Santa Barbara, California 93106 (United States); Quantum Architectures and Computation Group, Microsoft Research, Redmond, Washington 98052 (United States); Freedman, Michael H., E-mail: michaelf@microsoft.com [Department of Mathematics, University of California, Santa Barbara, California 93106 (United States); Microsoft Research, Station Q, University of California, Santa Barbara, California 93106 (United States); Sattath, Or, E-mail: sattath@gmail.com [Computer Science Division, University of California, Berkeley, California 94720 (United States); Stong, Richard, E-mail: stong@ccrwest.org; Minton, Greg, E-mail: gtminto@ccrwest.org [Center for Communications Research, La Jolla, California 92121 (United States)

2016-06-15

The classical max-flow min-cut theorem describes transport through certain idealized classical networks. We consider the quantum analog for tensor networks. By associating an integral capacity to each edge and a tensor to each vertex in a flow network, we can also interpret it as a tensor network and, more specifically, as a linear map from the input space to the output space. The quantum max-flow is defined to be the maximal rank of this linear map over all choices of tensors. The quantum min-cut is defined to be the minimum product of the capacities of edges over all cuts of the tensor network. We show that unlike the classical case, the quantum max-flow=min-cut conjecture is not true in general. Under certain conditions, e.g., when the capacity on each edge is some power of a fixed integer, the quantum max-flow is proved to equal the quantum min-cut. However, concrete examples are also provided where the equality does not hold. We also found connections of quantum max-flow/min-cut with entropy of entanglement and the quantum satisfiability problem. We speculate that the phenomena revealed may be of interest both in spin systems in condensed matter and in quantum gravity.

Cutting Class Harms Grades

Science.gov (United States)

Taylor, Lewis A., III

2012-01-01

An accessible business school population of undergraduate students was investigated in three independent, but related studies to determine effects on grades due to cutting class and failing to take advantage of optional reviews and study quizzes. It was hypothesized that cutting classes harms exam scores, attending preexam reviews helps exam…

Sodium-cutting: a new top-down approach to cut open nanostructures on nonplanar surfaces on a large scale.

Science.gov (United States)

Chen, Wei; Deng, Da

2014-11-11

We report a new, low-cost and simple top-down approach, "sodium-cutting", to cut and open nanostructures deposited on a nonplanar surface on a large scale. The feasibility of sodium-cutting was demonstrated with the successfully cutting open of ∼100% carbon nanospheres into nanobowls on a large scale from Sn@C nanospheres for the first time.

Multi-Criteria Analysis of Laser Cut Surface Characteristics in CO2 Laser Cutting of Stainless Steel

Directory of Open Access Journals (Sweden)

M. Radovanović

2015-06-01

Full Text Available In this paper an approach for multi-criteria analysis of laser cut surface characteristics using multi-criteria decision making (MCDM approach was presented. Laser cutting experiment was conducted based on Taguchi’s L27 experimental design by varying laser power, cutting speed, assist gas pressure and focus position at three levels. Multi-criteria analysis was performed by using the weighted aggregated sum product assessment (WASPAS method while considering burr height, drag line separation, depth of separation line, surface roughness and perpendicularity of the cut as assessment criteria. Based on conducted experimental investigation the MCDM model with 27 alternatives (laser cuts and five criteria was developed. The relative importance of criteria was determined by using pair-wise comparison matrix and geometric mean method of the analytic hierarchy process (AHP method.

Material testing of copper by extrusion-cutting

DEFF Research Database (Denmark)

Segalina, F.; De Chiffre, Leonardo

2017-01-01

was developed and implemented on a CNC lathe. An investigation was carried out extrusion-cutting copper discs using high-speed-steel cutting tools at 100 m/min cutting speed. Flow stress values for copper under machining-relevant conditions were obtained from measurement of the extrusion-cutting force...

Baikov-Lee representations of cut Feynman integrals

International Nuclear Information System (INIS)

Harley, Mark; Moriello, Francesco; Schabinger, Robert M.

2017-01-01

We develop a general framework for the evaluation of d-dimensional cut Feynman integrals based on the Baikov-Lee representation of purely-virtual Feynman integrals. We implement the generalized Cutkosky cutting rule using Cauchy’s residue theorem and identify a set of constraints which determine the integration domain. The method applies equally well to Feynman integrals with a unitarity cut in a single kinematic channel and to maximally-cut Feynman integrals. Our cut Baikov-Lee representation reproduces the expected relation between cuts and discontinuities in a given kinematic channel and furthermore makes the dependence on the kinematic variables manifest from the beginning. By combining the Baikov-Lee representation of maximally-cut Feynman integrals and the properties of periods of algebraic curves, we are able to obtain complete solution sets for the homogeneous differential equations satisfied by Feynman integrals which go beyond multiple polylogarithms. We apply our formalism to the direct evaluation of a number of interesting cut Feynman integrals.

Comparison of cutting efficiency with different diamond burs and water flow rates in cutting lithium disilicate glass ceramic.

Science.gov (United States)

Siegel, Sharon C; Patel, Tejas

2016-10-01

This study compared different diamond burs and different water flow rates on the cutting efficiency of sectioning through lithium disilicate glass ceramic. The authors used a standardized cutting regimen with 4 brands of diamond burs to section through lithium disilicate glass ceramic blocks. Twelve diamonds of each brand cut through the blocks in randomized order. In the first part of the study, the authors recorded sectioning rates in millimeters per minute for each diamond bur as a measure of cutting efficiency. In the second part of the study, the authors compared sectioning rates using only 1 brand of diamond bur, with 3 different water flow rates. The authors averaged and compared cutting rates of each brand of diamond bur and the cutting rates for each flow rate using an analysis of variance and determined the differences with a Tukey honest significant difference test. One diamond bur cut significantly slower than the other 3, and one diamond bur cut significantly faster than 2 of the others. The diamond bur cutting efficiency through lithium disilicate glass ceramic with a 20 mL/min water flow rate was significantly higher than 15 mL/min. There are differences in cutting efficiency between diamond burs when sectioning lithium disilicate glass ceramic. Use a minimum of 20 mL/min of water coolant flow when sectioning lithium disilicate glass ceramic with dental diamond burs to maximize cutting efficiency. Recommendations for specific diamond burs with a coarse grit and water flow rate of 20 mL/min can be made when removing or adjusting restorations made from lithium disilicate glass ceramic. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

Comparative study of 0° X-cut and Y + 36°-cut lithium niobate high-voltage sensing

International Nuclear Information System (INIS)

Patel, N.; Branch, D. W.; Cular, S.; Schamiloglu, E.

2015-01-01

A comparison study between Y + 36° and 0° X-cut lithium niobate (LiNbO 3 ) was performed to evaluate the influence of crystal cut on the acoustic propagation to realize a piezoelectric high-voltage sensor. The acoustic time-of-flight for each crystal cut was measured when applying direct current (DC), alternating current (AC), and pulsed voltages. Results show that the voltage-induced shift in the acoustic wave propagation time scaled quadratically with voltage for DC and AC voltages applied to X-cut crystals. For the Y + 36° crystal, the voltage-induced shift scales linearly with DC voltages and quadratically with AC voltages. When applying 5 μs voltage pulses to both crystals, the voltage-induced shift scaled linearly with voltage. For the Y + 36° cut, the voltage-induced shift from applying DC voltages ranged from 10 to 54 ps and 35 to 778 ps for AC voltages at 640 V over the frequency range of 100 Hz–100 kHz. Using the same conditions as the Y + 36° cut, the 0° X-cut crystal sensed a shift of 10–273 ps for DC voltages and 189–813 ps for AC voltage application. For 5 μs voltage pulses, the 0° X-cut crystal sensed a voltage induced shift of 0.250–2 ns and the Y + 36°-cut crystal sensed a time shift of 0.115–1.6 ns. This suggests a frequency sensitive response to voltage where the influence of the crystal cut was not a significant contributor under DC, AC, or pulsed voltage conditions. The measured DC data were compared to a 1-D impedance matrix model where the predicted incremental length changed as a function of voltage. When the voltage source error was eliminated through physical modeling from the uncertainty budget, the combined uncertainty of the sensor (within a 95% confidence interval) decreased to 0.0033% using a Y + 36°-cut crystal and 0.0032% using an X-cut crystal for all the voltage conditions used in this experiment

Underwater laser cutting of metallic structures

International Nuclear Information System (INIS)

Alfille, J.P.; Schildknecht, J.; Ramaswami, V.S.

1993-01-01

In the frame of an european contract, the feasibility of the underwater cutting with a CO 2 laser power is studied. The aim of this work is the dismantling metallic structures of reactors pools. The paper analyzes the general concept of the experimental device, the underwater cutting head, the experimenting vessel, examples of cuttings in dismantling situation with a 500 W CO 2 laser, and examples of cuttings with a 5 kW CO 2 laser. (author). 2 refs., 9 figs., 2 tabs

Theoretical aspects of fibre laser cutting

Energy Technology Data Exchange (ETDEWEB)

Mahrle, A; Beyer, E, E-mail: achim.mahrle@iws.fraunhofer.d [University of Technology Dresden, Institute for Surface and Manufacturing Technology, PO Box, 01062 Dresden (Germany)

2009-09-07

Fibre lasers offer distinct advantages over established laser systems with respect to power efficiency, beam guidance and beam quality. Consequently, the potential of these new laser beam sources will be increasingly exploited for laser cutting applications that are conventionally carried out with CO{sub 2} lasers. However, theoretical estimates of the effective absorptivity at the cut front suggest that the shorter wavelength of the fibre laser in combination with its high focusability seems to be primarily advantageous for thin sheet metal cutting whereas the CO{sub 2} laser is probably still capable of cutting thicker materials more efficiently. This surprising result is a consequence of the absorptivity behaviour of metals that shows essential quantitative differences for the corresponding wavelengths of both laser sources as a function of the angle of incidence between the laser beam and the material to be cut. In evaluation of the revealed dependences, solution strategies for an improvement of the efficiency of fibre laser cutting of thicker metal sheets are suggested.

A Numerical Approach and Comparison of Cutting Forces and Chip Morphology in Orthogonal Cutting of Light Alloys

International Nuclear Information System (INIS)

Alvarez, Roberto; Domingo, Rosario; Sebastian, Miguel Angel

2011-01-01

This paper deals with the simulation of UNS A92024 aluminium alloy cutting processes. In particular, 2D and 3D Finite Element Method (FEM) simulations were carried out in order to estimate cutting forces and chip morphology during turning operations. The material is modelled with two different set of parameters for the Johnson--Cook's (J-C) constitutive equation and a failure Cockroft and Latham's model exploited considers damage. The comparison between the predicted chip morphology and principal cutting forces at varying of J-C parameters and cutting regimes with those experimentally found are presented and discussed. The paper shows the importance of damage criterion in the cutting forces, during the simulation, especially in 3D.

Laser cutting of sheets for Tailored Blanks

DEFF Research Database (Denmark)

Bagger, Claus; Olsen, Flemming Ove

1999-01-01

sound welds. Laser cutting the sheets may therefore be an alternative to shear cutting, if the cut kerf squareness can be kept below 0.05 mm.In a number of systematic laboratory experiments the effects of the major process parameters in laser cutting have been investigated. Each cut was quantified...... by the squareness, the surface roughness and the burr height. Mild steel as well as high strength steel with and with out galvanisation with thickness' of 0.7(5) and 1.25 were used.In the tests the difference in cut quality between a 5" and a 7.5" focusing lens were tested and the effect of using pulsed mode laser...

Cutting prepregs, cutting and processing polymer plastics in the manufacture of airсraft panels

OpenAIRE

MELUKHOV NIKITA; GRISHCHENKO TATIANA; LYUBUSHKIN VADIM

2017-01-01

The article presents an alternative to the solution of the problem of reduction of manual operations in manufacture. It may be achieved if cutting out prepregs and processing polymeric materials (PMP) be changed for sharp ultrasonic cutting when manufacturing components from polymeric composite materials (PCM). Described are the lines of investigations on new techniques of cutting out prepreg and processings polymeric material of the Nomex type with the use of the energy of ultrasonic waves. ...

Semantic Versus Syntactic Cutting Planes

OpenAIRE

Filmus, Yuval; Hrubeš, Pavel; Lauria, Massimo

2016-01-01

In this paper, we compare the strength of the semantic and syntactic version of the cutting planes proof system. First, we show that the lower bound technique of Pudlák applies also to semantic cutting planes: the proof system has feasible interpolation via monotone real circuits, which gives an exponential lower bound on lengths of semantic cutting planes refutations. Second, we show that semantic refutations are stronger than syntactic ones. In particular, we give a formula for whic...

21 CFR 882.4275 - Dowel cutting instrument.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dowel cutting instrument. 882.4275 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4275 Dowel cutting instrument. (a) Identification. A dowel cutting instrument is a device used to cut dowels of bone for bone grafting. (b...

High speed laser cutting machine. Kosoku reza kakoki

Energy Technology Data Exchange (ETDEWEB)

Shinno, N. (Matsushita Electric Industrial Co. Ltd., Kadoma, Osaka (Japan))

1993-11-01

The carbon dioxide gas laser cutting machine is being used widely for from cutting soft steel and stainless steel, etc. to intermetallic welding and in the field of cutting in particular, concerning sheet cutting, it has been changing the existing monopoly of the turret punch press, and as for medium and thick plate cutting, that of the gas plasma fusing device. This article is the general description of high speed laser cutting machine. Concerning the laser cutting (sheet cutting in particular), as the essential items for securing severe cutting accuracy and, at the same time, improving the cutting speed, the following matters are picked up for respective explanation; improvement of stationary machine accuracy, improvement of dynamic machine accuracy, improvement of quality of laser beam as well as optimization of cutting conditions, and shortening of piercing time. Also explanation is given to the respective items, namely speeding-up of medium and thick plate cutting, and reduction of load onto the operator by improved operation. Finally, feeding and removing of a sheet only, and feeding and removing with a pallet are mentioned as the efforts for automation and energy saving. 3 figs., 1 tab.

Improving rooting uniformity in rose cuttings

NARCIS (Netherlands)

Telgen, van H.J.; Eveleens-Clark, B.A.; Garcia Victoria, N.

2007-01-01

Studies to improve rooting uniformity of single node stem cuttings for rose are reported. We found that the variation in shoot growth in a young rose crop depended on the variation in root number of the cuttings, which, in turn, was related to the auxin concentration applied to the cutting before

Underwater laser cutting of metal structures

Energy Technology Data Exchange (ETDEWEB)

Alfille, J.P.; Prunele, D. de [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Direction des Technologies Avancees; Pilot, G. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Dept. de Protection de l`Environnement et des Installations; Fredrick, P.; Ramaswami, V.S.; Muys, P. [Radius Engineering, Gent (Belgium)

1994-12-31

Cutting tests were carried out on stainless steel (304L) in air and under 7 meters of water (application to reactor pools), using CO{sub 2} and YAG lasers; results concerned cutting speed, quality of cut, cutting thickness. By-products of sectioning operations using a CO{sub 2} laser were studied: dross, aerosols, suspended particles in water, gas analysis, chemical analysis of the aerosols. Same measurements are currently being taken in the case of the YAG laser with beam transported via optical fiber. (from author). 16 figs., 2 tabs., 3 refs.

Underwater laser cutting of metal structures

International Nuclear Information System (INIS)

Alfille, J.P.; Prunele, D. de

1994-01-01

Cutting tests were carried out on stainless steel (304L) in air and under 7 meters of water (application to reactor pools), using CO 2 and YAG lasers; results concerned cutting speed, quality of cut, cutting thickness. By-products of sectioning operations using a CO 2 laser were studied: dross, aerosols, suspended particles in water, gas analysis, chemical analysis of the aerosols. Same measurements are currently being taken in the case of the YAG laser with beam transported via optical fiber. (from author). 16 figs., 2 tabs., 3 refs

The Effect of Muscle Fiber Direction on the Cut Surface Angle of Frozen Fish Muscular Tissue Cut by Bending Force

OpenAIRE

岡本, 清; 羽倉, 義雄; 鈴木, 寛一; 久保田, 清

1996-01-01

We have proposed a new cutting method named "Cryo-cutting" for frozen foodstuffs by applying a bending force instead of conventional cutting methods with band saw. This paper investigated the effect of muscle fiber angle (θf) to cut surface angle (θs) of frozen tuna muscular tissue at -70, -100 and -130°C for the purpose of evaluating the applicability of the cryo-cutting method to frozen fishes. The results were as follows : (1) There were two typical cutting patterns ("across the muscle fib...

Are the same tapes really the same? Ultrasound study of laser-cut and mechanically cut TVT-O post-operative behavior.

Science.gov (United States)

Rusavy, Zdenek; Masata, Jaromir; Svabik, Kamil; Hubka, Petr; Zvara, Karel; Martan, Alois

2017-11-25

TVT-O production has been modified to laser cutting from mechanical cutting. We compared the behavior of laser and mechanically cut tension-free vaginal tape-obturator (TVT-O) using ultrasound at various time points after surgery. This is a retrospective analysis of clinical and ultrasound data from two previously reported randomized controlled trials with TVT-O. Behavior of mechanically cut TVT-O implanted in January 2007 to November 2009 and laser-cut TVT-O implanted in May 2010 to May 2012 was assessed by ultrasound at day 1, the 2nd week, the 3rd month, and the 1st and 2nd years post-operatively. Bladder neck and tape margins positions were described by coordinates in the orthogonal system calculated from polar coordinates. Tape mobility was measured as a change in the upper and lower tape margin position from rest to maximal Valsalva. Comparison of 2-year subjective and objective surgery outcomes was also performed. In total, 68 mechanically cut and 50 laser-cut TVT-Os were implanted. Follow-up data were available from 49 and 45 women respectively. No differences in any baseline characteristics or bladder neck mobility were observed. Significantly lower tape mobility was observed on day 1 and week 2 after mechanically cut TVT-O, although subsequent mobility was comparable to laser-cut TVT-O. The subjective and objective surgery outcomes were comparable. Although without clinical significance, early postoperative behavior of the mechanically cut and laser-cut TVT-O tapes differs. The less stiff, mechanically-cut TVT-O loosens within 2 weeks of implantation, whereas the stiffer, laser-cut TVT-O keeps its tension.

Effects of cutting and maturity on lycopene concentration of fresh-cut tomatoes during storage at different temperatures

NARCIS (Netherlands)

Moreira Lana, M.; Dekker, M.; Linssen, R.F.A.; Kooten, van O.

2005-01-01

To investigate the changes in lycopene concentration of fresh-cut tomato during storage, tomato fruits at different stages of maturity were cut into 7 mm slices and stored at temperatures varying from 2°C to 16°C. To assess the effect of cutting, intact fruit were stored in an additional experiment

Underwater plasma arc cutting

International Nuclear Information System (INIS)

Leautier, R.; Pilot, G.

1991-01-01

This report describes the work done to develop underwater plasma arc cutting techniques, to characterise aerosols from cutting operations on radioactive and non-radioactive work-pieces, and to develop suitable ventilation and filtration techniques. The work has been carried out in the framework of a contract between CEA-CEN Cadarache and the Commission of European Communities. Furthermore, this work has been carried out in close cooperation with CEA-CEN Saclay mainly for secondary emissions and radioactive analysis. The contract started in May 1986 and was completed in December 1988 by a supplementary agreement. This report has been compiled from several progress reports submitted during the work period, contains the main findings of the work and encloses the results of comparative tests on plasma arc cutting

Modified GrabCut for human face segmentation

Directory of Open Access Journals (Sweden)

Dina Khattab

2014-12-01

Full Text Available GrabCut is a segmentation technique for 2D still color images, which is mainly based on an iterative energy minimization. The energy function of the GrabCut optimization algorithm is based mainly on a probabilistic model for pixel color distribution. Therefore, GrabCut may introduce unacceptable results in the cases of low contrast between foreground and background colors. In this manner, this paper presents a modified GrabCut technique for the segmentation of human faces from images of full humans. The modified technique introduces a new face location model for the energy minimization function of the GrabCut, in addition to the existing color one. This location model considers the distance distribution of the pixels from the silhouette boundary of a fitted head, of a 3D morphable model, to the image. The experimental results of the modified GrabCut have demonstrated better segmentation robustness and accuracy compared to the original GrabCut for human face segmentation.

Materials selection for cutting tools

International Nuclear Information System (INIS)

Burkhis, Adel M.

2008-01-01

The selection of proper tool steel for a given application is a difficult task. So; the most important selection factors in choosing cutting tool materials are based on their tool material requirements, cutting tool design and service conditions which is mainly considered as functional requirements. The processability requirements concerns in heat treat ability of the material tool. The classification of these tool materials were discussed with their properties requirement and percent of alloying element which is added to give best properties with a little increase in cost that highly appear in comparison of the selection. The cutting tool materials were evaluated based on two cases; The first was in case of rough surface; the high speed steels is the best material and the other was the ceramic material is the highest performance in cutting of soft or high rate of metal removal. (author)

Edge Cut Domination, Irredundance, and Independence in Graphs

OpenAIRE

Fenstermacher, Todd; Hedetniemi, Stephen; Laskar, Renu

2016-01-01

An edge dominating set $F$ of a graph $G=(V,E)$ is an \\textit{edge cut dominating set} if the subgraph $\\langle V,G-F \\rangle$ is disconnected. The \\textit{edge cut domination number} $\\gamma_{ct}(G)$ of $G$ is the minimum cardinality of an edge cut dominating set of $G.$ In this paper we study the edge cut domination number and investigate its relationships with other parameters of graphs. We also introduce the properties edge cut irredundance and edge cut independence.

Preferences of cut flowers consumers

Directory of Open Access Journals (Sweden)

Sylwia Kierczyńska

2010-01-01

Full Text Available The results of interviews suggest that majority of the cut flowers’ consumers has favourite kind of flower, among which most frequently pointed one was the rose. More than half of the interviewed favour the uniform colour of cut flowers and red colour was the most favourite one. The subtle smell of flowers was the most preferable one but the intensive fragrance was favoured for more consumers than odourless flowers. The data from selected florists’ confirm the information from interviews – in spite of the occasion, roses were the most demanded cut flowers.

Designing for hot-blade cutting

DEFF Research Database (Denmark)

Brander, David; Bærentzen, Jakob Andreas; Clausen, Kenn

2016-01-01

In this paper we present a novel method for the generation of doubly-curved, architectural design surfaces using swept Euler elastica and cubic splines. The method enables a direct design to production workflow with robotic hot-blade cutting, a novel robotic fabrication method under development......-trivial constraints of blade-cutting in a bottom-up fashion, enabling an exploration of the unique architectural potential of this fabrication approach. The method is implemented as prototype design tools in MatLAB, C++, GhPython, and Python and demonstrated through cutting of expanded polystyrene foam design...

Cluster formulation in the dual topological unitarization

International Nuclear Information System (INIS)

Hossain, M.

1979-02-01

The work of Chiu, Hossain, and Tow is generalized by incorporating the no double counting condition and the t/sub min/ effect in the integral equations for the Reggeon and the Pomeron. The relation between the no double counting condition and the average cluster separation is derived, and a test is proposed to determine the correct counting. It is shown that the t/sub min/ effect is quite important in determining the Regge parameters. The model predicts a relation between five physical quantities: the Pomeron intercept (α/sub p/ 0 ) and slope (α/sub p/'), the magnitude (k) and the exponential dependence (b) of the triple-Regge vertex, and the ratio of Pomeron to Reggeon residues (c) at t = 0. The solutions obtained are well within the range of acceptable values. A reasonable solution is, for example, α/sub p/ 0 = .92, α/sub p/' = .2, b = 1.6, k = 12.9, and c = 0.91. It is found that cuts are present in both the Reggeon and the Pomeron amplitudes, and their contributions are small compared to the leading poles. 27 references

Status on underwater plasma arc cutting in KHI, 3

International Nuclear Information System (INIS)

Abe, Tadashi; Aota, Toshiichi; Nishizaki, Tadashi; Nakayama, Shigeru; Yamashita, Seiji

1983-01-01

In Kawasaki Heavy Industries, Ltd., the development of a remote dismantling system by underwater plasma arc cutting process has been advanced, expecting its application to the dismantling and removal of nuclear reactor facilities. In the previous two reports, the fundamental experimental results such as the comparison of the cutting capability in air and in water were shown, but this time, the remote automatic cutting of wedge-shaped specimens was carried out, using a newly installed manipulator for underwater works, therefore its outline is reported. Also the cutting experiment by overhead position and vertical position was performed by using the same equipment, and comparison was made with the cutting capability by downhand and horizontal positions. It is important to grasp the cutting characteristics in the case of upward advancing and downward advancing cuttings by overhead and vertical positions when the cutting of pressure vessels and horizontal pipes into rings is supposed. The experimental apparatus, the cutting conditions, the testing method and the test results of the cutting capability test, the test of changing direction during cutting, and the remote cutting of pipes into rings are described. The underwater plasma arc cutting can cut all metals, the cutting speed is relatively high, and the apparatus is simple and compact. (Kako, I.)

MECHANISMS OF CUTTING BLADE WEAR AND THEIR INFLUENCE ON CUTTING ABILITY OF THE TOOL DURING MACHINING OF SPECIAL ALLOYS

Directory of Open Access Journals (Sweden)

Tomáš Zlámal

2016-09-01

Full Text Available With increased requirements for quality and shelf life of machined parts there is also a higher share of the use of material with specific properties that are identified by the term “superalloys”. These materials differ from common steels by mechanical and physical properties that cause their worse machinability. During machining of “superalloys” worse machinability has negative influence primarily on the amount of cutting edge wear, which shortens durability of the cutting tool. The goal of experimental activity shown in this contribution is to determine individual mechanisms of the cutting edge wear and their effects on the cutting ability during high speed machining of nickel superalloy. A specific exchangeable cutting insert made from cubic boric nitride was used for machining of the 625 material according to ASM 5666F. The criteria to evaluate cutting ability and durability of the cutting tool became selected parameters of surface integrity and quality of the machined surface.

Submerged cutting characteristics of abrasive suspension jet

International Nuclear Information System (INIS)

Shimizu, Seiji; Peng, Guoyi; Oguma, Yasuyuki; Nishikata, Hiroki

2015-01-01

An abrasive suspension jet (ASJ) formed by propelling abrasive suspension through a nozzle has a greater cutting capability than the conventional abrasive water jet. However the cutting capability of submerged ASJs decreases drastically with increasing the standoff distance and the pressure around the jet. A sheathed nozzle nozzle with ventilation for ASJs has been developed as a mean of extending the effective stand-off distance and improving the cutting capabilities under submerged condition. In the present investigation, cutting tests by ASJs in air and under submerged condition are conducted with specimens of aluminum alloy. Air coated ASJs are formed by using a sheathed nozzle with ventilation. The relative cutting depth is defined as the cutting depth is arranged effectually by the cavitation number based on the cavity pressure measured at the sheath. (author)

Ann modeling of kerf transfer in Co2 laser cutting and optimization of cutting parameters using monte carlo method

Directory of Open Access Journals (Sweden)

Miloš Madić

2015-01-01

Full Text Available In this paper, an attempt has been made to develop a mathematical model in order to study the relationship between laser cutting parameters such as laser power, cutting speed, assist gas pressure and focus position, and kerf taper angle obtained in CO2 laser cutting of AISI 304 stainless steel. To this aim, a single hidden layer artificial neural network (ANN trained with gradient descent with momentum algorithm was used. To obtain an experimental database for the ANN training, laser cutting experiment was planned as per Taguchi’s L27 orthogonal array with three levels for each of the cutting parameters. Statistically assessed as adequate, ANN model was then used to investigate the effect of the laser cutting parameters on the kerf taper angle by generating 2D and 3D plots. It was observed that the kerf taper angle was highly sensitive to the selected laser cutting parameters, as well as their interactions. In addition to modeling, by applying the Monte Carlo method on the developed kerf taper angle ANN model, the near optimal laser cutting parameter settings, which minimize kerf taper angle, were determined.

The effects of cutting parameters on cutting forces and heat generation when drilling animal bone and biomechanical test materials.

Science.gov (United States)

Cseke, Akos; Heinemann, Robert

2018-01-01

The research presented in this paper investigated the effects of spindle speed and feed rate on the resultant cutting forces (thrust force and torque) and temperatures while drilling SawBones ® biomechanical test materials and cadaveric cortical bone (bovine and porcine femur) specimens. It also investigated cortical bone anisotropy on the cutting forces, when drilling in axial and radial directions. The cutting forces are only affected by the feed rate, whereas the cutting temperature in contrast is affected by both spindle speed and feed rate. The temperature distribution indicates friction as the primary heat source, which is caused by the rubbing of the tool margins and the already cut chips over the borehole wall. Cutting forces were considerably higher when drilling animal cortical bone, in comparison to cortical test material. Drilling direction, and therewith anisotropy, appears to have a negligible effect on the cutting forces. The results suggest that this can be attributed to the osteons being cut at an angle rather than in purely axial or radial direction, as a result of a twist drill's point angle. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Evaluation of cutting force uncertainty components in turning

DEFF Research Database (Denmark)

Axinte, Dragos Aurelian; Belluco, Walter; De Chiffre, Leonardo

2000-01-01

A procedure is proposed for the evaluation of those uncertainty components of a single cutting force measurement in turning that are related to the contributions of the dynamometer calibration and the cutting process itself. Based on an empirical model including errors form both sources......, the uncertainty for a single measurement of cutting force is presented, and expressions for the expected uncertainty vs. cutting parameters are proposed. This approach gives the possibility of evaluating cutting force uncertainty components in turning, for a defined range of cutting parameters, based on few...

Identification of the critical depth-of-cut through a 2D image of the cutting region resulting from taper cutting of brittle materials

Science.gov (United States)

Gu, Wen; Zhu, Zhiwei; Zhu, Wu-Le; Lu, Leyao; To, Suet; Xiao, Gaobo

2018-05-01

An automatic identification method for obtaining the critical depth-of-cut (DoC) of brittle materials with nanometric accuracy and sub-nanometric uncertainty is proposed in this paper. With this method, a two-dimensional (2D) microscopic image of the taper cutting region is captured and further processed by image analysis to extract the margin of generated micro-cracks in the imaging plane. Meanwhile, an analytical model is formulated to describe the theoretical curve of the projected cutting points on the imaging plane with respect to a specified DoC during the whole cutting process. By adopting differential evolution algorithm-based minimization, the critical DoC can be identified by minimizing the deviation between the extracted margin and the theoretical curve. The proposed method is demonstrated through both numerical simulation and experimental analysis. Compared with conventional 2D- and 3D-microscopic-image-based methods, determination of the critical DoC in this study uses the envelope profile rather than the onset point of the generated cracks, providing a more objective approach with smaller uncertainty.

Cutting tool for removing materials from well bore

International Nuclear Information System (INIS)

Lynde, G.D.; Harvey, H.H. Jr.

1991-01-01

This patent describes a cutting tool adapted to be positioned downhole in a well bore for removing a metal member from the well bore; a tool body adapted to be received within said well bore and to be supported at its upper end for rotation about a longitudinal axis; blades at spaced intervals on the body and extending outwardly therefrom, each of the blades having a base with a leading surface relative to the direction of rotation; closely spaced cutting elements of hard cutting material secured to said leading surface of the base in a plurality of transversely extending rows, each cutting element being of a predetermined size and shape and arranged in a predetermined generally symmetrical pattern on the base relative to the other elements, each of said cutting elements having an exposed from cutting face forming a cutting surface, a rear face secured to the leading surface of said base, a peripheral surface extending between said faces, and a relatively sharp edge formed at the juncture of the front face and peripheral surface; the front cutting face of each cutting element being arranged and constructed for directing an extending end portion of a turning cut form said member to effect a breaking of said turning from the member being cut in a predetermined manner to minimize interesting of the turning

Craterlike structures on the laser cut surface

Science.gov (United States)

Shulyatyev, V. B.; Orishich, A. M.

2017-10-01

Analysis of the laser cut surface morphology remain topical. It is related with the fact that the surface roughness is the main index of the cut quality. The present paper deals with the experimental study of the relatively unstudied type of defects on the laser cut surface, dimples, or craters. According to the measurement results, amount of craters per unit of the laser cut surface area rises as the sheet thickness rises. The crater diameter rises together with the sheet thickness and distance from the upper sheet edge. The obtained data permit concluding that the defects like craters are observed predominantly in the case of thick sheets. The results agree with the hypothesis of crater formation as impact structures resulting from the melt drops getting on the cut channel walls upon separation from the cut front by the gas flow.

The Gesso Cut for Printmaking

Science.gov (United States)

Kelly, Perry; Sarvis, Alva

1969-01-01

Directions are given for the preparation, cutting, and printing of a gesso board. A gesso cut is defined as a board coated with gesso into which a design has been impressed. The process is similar to the woodcut, but offers greater textural possibilities. (BF)

Laser cutting of Kevlar laminates

Energy Technology Data Exchange (ETDEWEB)

VanCleave, R.A.

1977-09-01

An investigation has been conducted of the use of laser energy for cutting contours, diameters, and holes in flat and shaped Kevlar 49 fiber-reinforced epoxy laminates as an alternate to conventional machining. The investigation has shown that flat laminates 6.35 mm thick may be cut without backup by using a high-powered (1000-watt) continuous wave CO/sub 2/ laser at high feedrates (33.87 mm per second). The cut produced was free of the burrs and delaminations resulting from conventional machining methods without intimate contact backup. In addition, the process cycle time was greatly reduced.

Investigation of cutting-induced damage in CMC bend bars

Directory of Open Access Journals (Sweden)

Neubrand A.

2015-01-01

Full Text Available Ceramic matrix composites (“CMC” with a strong fibre-matrix interface can be made damage-tolerant by introducing a highly porous matrix. Such composites typically have only a low interlaminar shear strength, which can potentially promote damage when preparing specimens or components by cutting. In order to investigate the damage induced by different cutting methods, waterjet cutting with and without abrasives, laser-cutting, wire eroding and cutoff grinding were used to cut plates of two different CMCs with a matrix porosity up to 35 vol.-%. For each combination of cutting method and composite, the flexural and interlaminar shear strength of the resulting specimens was determined. Additionally, the integrity of the regions near the cut surfaces was investigated by high-resolution x-ray computer tomography. It could be shown that the geometrical quality of the cut is strongly affected by the cutting method employed. Laser cut and waterjet cut specimens showed damage and delaminations near the cut surface leading to a reduced interlaminar shear strength of short bend bars in extreme cases.

Investigation of Cutting Quality of Remote DOE Laser Cutting in 0.5 mm Stainless Steel

Science.gov (United States)

Villumsen, Sigurd Lazic; Kristiansen, Morten

It has previously been shown that the stability of the remote fusion cutting (RFC) process can be increased by modifying the intensity profile of the laser by means of a diffractive optical element (DOE). This paper investigates the quality of remote DOE cutting (RDC) conducted with a 3 kW single mode fiber laser in 0.5 mm stainless steel. An automatic measurement system is used to investigate how the travel speed, focus offset and angle of incidence effect the kerf width and kerf variance. The study shows that the RDC process has a very low kerf width variance, and that the kerf width decreases with cutting speed. Furthermore, selected etched samples show a significant increase in the perpendicularity of the cuts when compared to RFC. Also, on average, the depth of the layer of molten material for RFC is 83% deeper than for RDC.

High precision tungsten cutting for optics

International Nuclear Information System (INIS)

Reglero, V.; Velasco, T.; Rodrigo, J.; Gasent, L.J.; Alamo, J.; Chato, R.; Ruiz Urien, I.; Santos, I.; Zarauz, J.; Clemente, G.; Sanz-Tudanca, C.; Lopez, J.L.

2001-01-01

The results obtained during the INTEGRAL masks development program an implementing the HURA and MURA codes on tungsten plates of different thickness are presented. Hard scientific requirements on pixels size and location tolerances (tenths of microns over large areas -1 m 2 - and thickness from 0.5 mm to 60 mm) required the set up of a dedicated program for testing cutting technologies: laser, photochemical milling, spark machining and electro discharge wire cutting. After a very intensive test campaign the wire cutting process was selected as the optimum technology for code manufacturing . Accuracies achieved an the code cutting fulfill scientific requirements. In fact, they are 5 times better than required. Pixel size and centroids location accuracies of 0.01 mm over a 1 m 2 area have been obtained for the 10,000 pixels on IBIS, 100 pixels on SPI and 24000 pixels on JEM-X masks. Comparative results among different cutting technologies are also discussed. (author)

Development of laser cutting method for stainless steel liner

International Nuclear Information System (INIS)

Ishihara, Satoshi; Takahata, Masato; Wignarajah, Sivakumaran; Kamata, Hirofumi

2007-01-01

The present work is an attempt to develop a laser cutting method for cutting and removing stainless steel liners from concrete walls and floors in nuclear facilities. The effect of basic laser cutting parameters such as energy, cutting speed, assist gas flow etc. were first studied through cutting experiments on mock-up concrete specimens lined with 3mm thick stainless steel sheets using a 1kW Nd:YAG laser. These initial studies were followed by further studies on the effect of unevenness of the liner surface and on a new method of confining contamination during the cutting process using a sliding evacuation hood attached to the laser cutting head. The results showed that laser cutting is superior to other conventional cutting methods from the point of view of safety from radioactivity and work efficiency when cutting contaminated stainless steel liners. (author)

Why I like power cuts...

CERN Multimedia

Computer Security Team

2012-01-01

Accidental power cuts - a permanent nuisance when running accelerators or computing services, since it takes a lot of time to recover from them. While I feel very sorry for those who are under pressure to get their service running again and deeply regret the loss of down-time and availability, I must admit that I like power cuts: power cuts make computers reboot! And rebooting computers at CERN means all the pending software patches are automatically applied.   But don’t think I am egotistic enough to endorse power cuts. Not necessarily! I am already happy if you regularly patch your computer(s) yourself, where regularly means at least once a month: · If you run a centrally or locally managed Windows computer, give that small orange blinking “CMF” icon in the taskbar a chance in the evening to apply all the pending patches. Also, let it initiate a reboot at the end! · If you have a personal computer with your own Windows operating system, ...

Method of dismantling cylindrical structure by cutting

International Nuclear Information System (INIS)

Harada, Minoru; Mitsuo, Kohei; Yokota, Isoya; Nakamura, Kenjiro.

1989-01-01

This invention concerns a method of cutting and removing cylindrical structures, for example, iron-reinforced concrete materials such as thermal shielding walls in BWR type power plants into block-like form. That is, in a method of cutting and removing the cylindrical structure from the side of the outer wall, the structural material is cut from above to below successively in the axial direction and the circumferential direction by means abrasive jet by remote operation and cut into blocks each of a predetermined size. The cut out blocks are successively taken out. Cutting of the material from above to below by remote operation and taking out of small blocks causes no hazards to human body. Upon practicing the present invention, it is preferred to use a processing device for slurry and exhaust gases for preventing scattering of activated dismantled pieces or powdery dusts. (K.M.)

Photodiode-based cutting interruption sensor for near-infrared lasers.

Science.gov (United States)

Adelmann, B; Schleier, M; Neumeier, B; Hellmann, R

2016-03-01

We report on a photodiode-based sensor system to detect cutting interruptions during laser cutting with a fiber laser. An InGaAs diode records the thermal radiation from the process zone with a ring mirror and optical filter arrangement mounted between a collimation unit and a cutting head. The photodiode current is digitalized with a sample rate of 20 kHz and filtered with a Chebyshev Type I filter. From the measured signal during the piercing, a threshold value is calculated. When the diode signal exceeds this threshold during cutting, a cutting interruption is indicated. This method is applied to sensor signals from cutting mild steel, stainless steel, and aluminum, as well as different material thicknesses and also laser flame cutting, showing the possibility to detect cutting interruptions in a broad variety of applications. In a series of 83 incomplete cuts, every cutting interruption is successfully detected (alpha error of 0%), while no cutting interruption is reported in 266 complete cuts (beta error of 0%). With this remarkable high detection rate and low error rate, the possibility to work with different materials and thicknesses in combination with the easy mounting of the sensor unit also to existing cutting machines highlight the enormous potential for this sensor system in industrial applications.

Users' manual for fault tree analysis code: CUT-TD

International Nuclear Information System (INIS)

Watanabe, Norio; Kiyota, Mikio.

1992-06-01

The CUT-TD code has been developed to find minimal cut sets for a given fault tree and to calculate the occurrence probability of its top event. This code uses an improved top-down algorithm which can enhance the efficiency in deriving minimal cut sets. The features in processing techniques incorporated into CUT-TD are as follows: (1) Consecutive OR gates or consecutive AND gates can be coalesced into a single gate. As a result, this processing directly produces cut sets for the redefined single gate with each gate not being developed. (2) The independent subtrees are automatically identified and their respective cut sets are separately found to enhance the efficiency in processing. (3) The minimal cut sets can be obtained for the top event of a fault tree by combining their respective minimal cut sets for several gates of the fault tree. (4) The user can reduce the computing time for finding minimal cut sets and control the size and significance of cut sets by inputting a minimum probability cut off and/or a maximum order cut off. (5) The user can select events that need not to be further developed in the process of obtaining minimal cut sets. This option can reduce the number of minimal cut sets, save the computing time and assists the user in reviewing the result. (6) Computing time is monitored by the CUT-TD code so that it can prevent the running job from abnormally ending due to excessive CPU time and produce an intermediate result. The CUT-TD code has the ability to restart the calculation with use of the intermediate result. This report provides a users' manual for the CUT-TD code. (author)

Monitoring machining conditions by analyzing cutting force vibration

Energy Technology Data Exchange (ETDEWEB)

Piao, Chun Guang; Kim, Ju Wan; Kim, Jin Oh; Shin, Yoan [Soongsl University, Seoul (Korea, Republic of)

2015-09-15

This paper deals with an experimental technique for monitoring machining conditions by analyzing cutting-force vibration measured at a milling machine. This technique is based on the relationship of the cutting-force vibrations with the feed rate and cutting depth as reported earlier. The measurement system consists of dynamic force transducers and a signal amplifier. The analysis system includes an oscilloscope and a computer with a LabVIEW program. Experiments were carried out at various feed rates and cutting depths, while the rotating speed was kept constant. The magnitude of the cutting force vibration component corresponding to the number of cutting edges multiplied by the frequency of rotation was linearly correlated with the machining conditions. When one condition of machining is known, another condition can be identified by analyzing the cutting-force vibration.

Monitoring machining conditions by analyzing cutting force vibration

International Nuclear Information System (INIS)

Piao, Chun Guang; Kim, Ju Wan; Kim, Jin Oh; Shin, Yoan

2015-01-01

This paper deals with an experimental technique for monitoring machining conditions by analyzing cutting-force vibration measured at a milling machine. This technique is based on the relationship of the cutting-force vibrations with the feed rate and cutting depth as reported earlier. The measurement system consists of dynamic force transducers and a signal amplifier. The analysis system includes an oscilloscope and a computer with a LabVIEW program. Experiments were carried out at various feed rates and cutting depths, while the rotating speed was kept constant. The magnitude of the cutting force vibration component corresponding to the number of cutting edges multiplied by the frequency of rotation was linearly correlated with the machining conditions. When one condition of machining is known, another condition can be identified by analyzing the cutting-force vibration

Melt Flow and Energy Limitation of Laser Cutting

Directory of Open Access Journals (Sweden)

Pavel Hudeček

2016-01-01

Full Text Available Laser technology is a convertible technology for plenty of parts in most materials. Laser material processing for industrial manufacturing applications is today a widespread procedure for welding, cutting, marking and micro machining of metal and plastic parts and components. Involvement and support this huge mass-production industry of laser cutting, new technology and dry-process using lasers were and are being actively developed. Fundamentally, industrial laser cutting or other applications on industry should satisfy the four key practical application issues including “Quality or Performance”, “Throughput or Speed”, “Cost or Total Ownership Cost”, and “Reliability”. Laser requires for examples several complicated physical factors to be resolved including die strength to be enable good wire-bonding and survival of severe cycling test, clean cutting wall surface, good cutting of direct attach film, and proper speed of cutting for achieving economy of throughput. Some example of maximum cutting rate, wherewith is normally limited laser energy, cutting speed is depend on type laser, different of cutting with one laser beam and beam pattern and applied laser power/material thickness will be introduced in this paper.

Feasibility Study of Cryogenic Cutting Technology by Using a Computer Simulation and Manufacture of Main Components for Cryogenic Cutting System

International Nuclear Information System (INIS)

Kim, Sung Kyun; Lee, Dong Gyu; Lee, Kune Woo; Song, Oh Seop

2009-01-01

Cryogenic cutting technology is one of the most suitable technologies for dismantling nuclear facilities due to the fact that a secondary waste is not generated during the cutting process. In this paper, the feasibility of cryogenic cutting technology was investigated by using a computer simulation. In the computer simulation, a hybrid method combined with the SPH (smoothed particle hydrodynamics) method and the FE (finite element) method was used. And also, a penetration depth equation, for the design of the cryogenic cutting system, was used and the design variables and operation conditions to cut a 10 mm thickness for steel were determined. Finally, the main components of the cryogenic cutting system were manufactures on the basis of the obtained design variables and operation conditions.

Comparison of blood loss between using non central part cutting knee prosthesis and distal central part cutting.

Science.gov (United States)

Malairungsakul, Anan

2014-12-01

Patients who undergo knee replacement surgery may need to receive a blood transfusion due to blood loss during the operation. Therefore it was important to improve the design of knee implant operative procedures in an attempt to reduce the rate of blood loss. The present study aimed to compare the blood loss between two types of knee replacement surgery. This is a retrospective study in which 78 patients received cemented knee replacements in Phayao Hospital between October 2010 and March 2012. There were two types of surgical procedure: 1) using an implant position covering the end of the femoral bone without cutting into the central part of the distal femoral, 2) using an implant position covering the end of the femoral bone cutting the central part of the distal femoral. Blood loss, blood transfusion, hemoglobin and hematocrit were recorded preoperatively, immediately postsurgery and 48 hours after surgery. Findings revealed that the knee replacement surgery using the implant position covering the end of the femoral bone without cutting the central part of the distal femoral significantly lowered the rate of blood loss when compared to using the implant position covering the end of the femoral bone with central cutting of the distal femor. The average blood loss during the operation without cutting at the central part of distal femoral was 49.50 ± 11.11 mL; whereas the operation cutting the central part of the distal femoral was 58.50 ± 11.69 mL. As regards blood loss, the knee replacement surgery using the implant position covering the end ofthefemoral bone without cutting the central part of distal femor was better than using the implant position covering the end of the femoral bone cutting at the central part of the distal femor.

Commissioning a hobby cutting device for radiochromic film preparation.

Science.gov (United States)

Zolfaghari, Somayeh; Francis, Kirby E; Kairn, Tanya; Crowe, Scott B

2017-06-01

In addition to a high spatial resolution and well characterised dose response, one of the major advantages of radiochromic film as a dosimeter is that sheets of film can be cut into pieces suitable for use as calibration films, and for in vivo and phantom measurements. The cutting of film is typically done using scissors or a guillotine, and this process can be time-consuming, limited in precision, requires extensive handling and does not allow holes to be cut from the film without cutting from an existing edge. This study investigated the use of a Brother ScanNCut hobby cutting system for EBT3 film preparation. The optimal operating parameters (blade size, pressure, speed) that resulted in precise cuts with minimal delamination at cut edges were identified using test cutting patterns. These parameters were then used to cut a large film insert for a stereotactic head phantom for comparison against an insert cut with scissors. While the hobby cutting system caused a wider region of delamination at the film edge (1.8 mm) compared to scissors (1 mm), the hobby cutting system was found to be able to produce reproducible cuts more efficiently and more accurately than scissors. The use of the hobby cutting system is recommended for complex phantom inserts (containing sharp corners or holes for alignment rods) or in situations where large numbers of film pieces need to be prepared.

Failure mechanisms of superhard materials when cutting superalloys

International Nuclear Information System (INIS)

Focke, A.E.; Westermann, F.E.; Ermi, A.; Yavelak, J.; Hoch, M.

1975-01-01

The present research studies the reasons for the failure of tungsten carbide tools while cutting superalloys. There is a continuous layer of the superalloy in the bottom of the crater which from time to time is torn away locally, taking tungsten carbide crystal with it. Under recommended cutting conditions a plateau (unworn cutting surface) separates the crater from the cutting edge of the tool when cutting AISI 4340. This plateau is totally absent in all cutting of Inconel 718, even in short, two-minute tests. The crater intersects the cutting edge--only a thin wedge of carbide is left which either breaks off or deforms and wears very rapidly. Temperature measurements carried out by use of an infrared detector aimed on the corner of the tungsten carbide indicate at recommended speeds a sharp rise of the temperature at the beginning of the cutting operation, then a steady-state very slow increase as the cutting continues, and finally just before tool failure a very rapid increase in the temperature again. Scanning and replica electron microscopy through the crater and flank face shows that both under the crater and in the back of the cutting edge a fairly deep layer of ''disturbed metal'' exists in which the tungsten carbide grains are much smaller and have much more rounded edges than in the original material. 10 figures, 4 tables

International feedback experience on the cutting of reactor internal components

International Nuclear Information System (INIS)

Boucau, J.

2014-01-01

Westinghouse capitalizes more than 30 years of experience in the cutting of internal components of reactor and their packaging in view of their storage. Westinghouse has developed and validated different methods for cutting: plasma torch cutting, high pressure abrasive water jet cutting, electric discharge cutting and mechanical cutting. A long feedback experience has enabled Westinghouse to list the pros and cons of each cutting technology. The plasma torch cutting is fast but rises dosimetry concerns linked to the control of the cuttings and the clarity of water. Abrasive water jet cutting requires the installation of costly safety devices and of an equipment for filtering water but this technology allows accurate cuttings in hard-to-reach zones. Mechanical cutting is the most favourable technology in terms of wastes generation and of the clarity of water but the cutting speed is low. (A.C.)

Shearer drums - the cutting edge

Energy Technology Data Exchange (ETDEWEB)

O' Neill, M.; Wright, C.

2004-09-15

The paper discusses continuous miner and shearer cutters. It claims cutting drum require the same level of engineering know-how and technical expertise as do the machines driving them, and that the cutting drum, whether on a longwall shearer or continuous miner, comprises, the steel, pedestals, bit holders and the bits.

29 CFR 1910.254 - Arc welding and cutting.

Science.gov (United States)

2010-07-01

... 29 Labor 5 2010-07-01 2010-07-01 false Arc welding and cutting. 1910.254 Section 1910.254 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Welding, Cutting and Brazing § 1910.254 Arc welding and cutting. (a... following limits shall not be exceeded: (i) Alternating-current machines (A) Manual arc welding and cutting...

7 CFR 58.413 - Cutting and packaging rooms.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Cutting and packaging rooms. 58.413 Section 58.413....413 Cutting and packaging rooms. When small packages of cheese are cut and wrapped, separate rooms shall be provided for the cleaning and preparation of the bulk cheese and for the cutting and wrapping...

Development of liner cutting method for stainless steel liner

International Nuclear Information System (INIS)

Takahata, Masato; Wignarajah, Sivakmaran; Kamata, Hirofumi

2005-01-01

The present work is an attempt to develop a laser cutting method for cutting and removing stainless steel liners from concrete walls and floors in cells and fuel storage pools of nuclear facilities. The effects of basic laser cutting parameters such as cutting speed, assist gas flow etc. were first studied applying a 1 kW Nd:YAG laser to mock up concrete specimens lined with 3 mm thick stainless steel sheets. These initial studies were followed by studies on the effect of unevenness of the liner surface and on methods of confining contamination during the cutting process. The results showed that laser cutting is superior to other conventional cutting methods from the point of view of safety from radioactivity and work efficiency when cutting contaminated stainless steel liners. In addition to the above results, this paper describes the design outline of a laser cutting system for cutting stainless liners at site and evaluates its merit and cost performance. (author)

7 CFR 58.726 - Cutting and grinding.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Cutting and grinding. 58.726 Section 58.726 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.726 Cutting and grinding. The trimmed and cleaned cheese should be cut into sections of...

A cutting force model for micromilling applications

DEFF Research Database (Denmark)

Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

2006-01-01

In micro milling the maximum uncut chip thickness is often smaller than the cutting edge radius. This paper introduces a new cutting force model for ball nose micro milling that is capable of taking into account the effect of the edge radius.......In micro milling the maximum uncut chip thickness is often smaller than the cutting edge radius. This paper introduces a new cutting force model for ball nose micro milling that is capable of taking into account the effect of the edge radius....

Effects of Cutting Tool Parameters on Vibration

Directory of Open Access Journals (Sweden)

Ince Mehmet Alper

2016-01-01

Full Text Available This paper presents of the influence on vibration of Co28Cr6Mo medical alloy machined on a CNC lathe based on cutting parameters (rotational speed, feed rate, depth of cut and tool tip radius. The influences of cutting parameters have been presented in graphical form for understanding. To achieve the minimum vibration, the optimum values obtained for rpm, feed rate, depth of cut and tool tip radius were respectively, 318 rpm, 0.25 mm/rev, 0.9 mm and 0.8 mm. Maximum vibration has been revealed the values obtained for rpm, feed rate, depth of cut and tool tip radius were respectively, 636 rpm, 0.1 mm/rev, 0,5 mm and 0.8 mm.

Diamond wire cutting of heat exchangers

International Nuclear Information System (INIS)

Beckman, T.R.; Bjerler, J.

1991-01-01

With the change-out of equipment at nuclear power plants comes large quantities of low level contaminated metallic waste. Of particular concern are large heat exchangers, preheaters and steam generators. These bulky items consume huge volumes of burial space. The need for volume reduction and recycling of these metals has created new demands for 'how' to cut heat exchangers into useful sizes for decontamination, melting or compaction. This paper reviews the cutting solution provided by a diamond wire system, with particular regard for cutting of a Ringhals Preheater Bundle at Studsvik Nuclear in 1989. The background of diamond wire sawing is discussed and basic components of wire sawing are explained. Other examples of wire cutting decommissioned components are also given. (author)

Assembly procedure for column cutting platform

International Nuclear Information System (INIS)

Routh, R.D.

1995-01-01

This supporting document describes the assembly procedure for the Column Cutting Platform and Elevation Support. The Column Cutting Platform is a component of the 241-SY-101 Equipment Removal System. It is set up on the deck of the Strongback Trailer to provide work access to cut off the upper portion of the Mitigation Pump Assembly (MPA). The Elevation Support provides support for the front of the Storage Container with the Strongback at an inclined position. The upper portion of the MPA must be cut off to install the Containment Caps on the Storage Container. The storage Container must be maintained in an inclined position until the Containment Caps are installed to prevent any residual liquids from migrating forward in the Storage Container

49 CFR 236.52 - Relayed cut-section.

Science.gov (United States)

2010-10-01

..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and Instructions: All Systems Track Circuits § 236.52 Relayed cut-section. Where relayed cut-section is used in... 49 Transportation 4 2010-10-01 2010-10-01 false Relayed cut-section. 236.52 Section 236.52...

LASER CUTTING MACHINES FOR 3-D THIN SHEET PARTS

Directory of Open Access Journals (Sweden)

Miroslav RADOVANOVIC

2012-11-01

Full Text Available Laser cutting machines are used for precise contour cutting thin sheet. In industrial application nowadays various types and construction of laser cutting machines can be met. For contour cutting 3-D thin sheet parts laser cutting machines with rotation movements and laser robots are used. Laser generates the light beam, that presents a tool in working process. Application of laser cutting machines made possible good quality of products, flexibility of production and enlargement of economy

Electric arc, water jet cutting of metals

International Nuclear Information System (INIS)

Bruening, D.

1991-01-01

For thermal dismantling and cutting of metallic components, as electric arc, water jet cutting method was developed that can be used for underwater cutting work up to a depth of 20 m. Short-circuiting of a continuously fed electrode wire in contact with the metal generates an electric arc which induces partial melting of the metal, and the water jet surrounding the wire rinses away the molten material, thus making a continuous kerf in the material. The method was also tested and modified to allow larger area, surface cutting and removal of metallic surface coatings. This is achieved by melting parts of the surface with the electric arc and subsequent rinsing by the water jet. The cutting and melting depth for surface removal can be accurately controlled by the operating parameters chosen. (orig./DG) [de

Modelling and optimization of cut quality during pulsed Nd:YAG laser cutting of thin Al-alloy sheet for straight profile

Science.gov (United States)

Sharma, Amit; Yadava, Vinod

2012-02-01

Thin sheets of aluminium alloys are widely used in aerospace and automotive industries for specific applications. Nd:YAG laser beam cutting is one of the most promising sheetmetal cutting process for cutting sheets for any profile. Al-alloy sheets are difficult to cut by laser beam because of its highly reflective nature. This paper presents modelling and optimization of cut quality during pulsed Nd:YAG laser cutting of thin Al-alloy sheet for straight profile. In the present study, four input process parameters such as oxygen pressure, pulse width, pulse frequency, and cutting speed and two output parameters such as average kerf taper ( Ta) and average surface roughness ( Ra) are considered. The hybrid approach comprising of Taguchi methodology (TM) and response surface methodology (RSM) is used for modelling whereas multi-objective optimization is performed using hybrid approach of TM and grey relational analysis (GRA) coupled with entropy measurement methodology. The entropy measurement methodology is employed for the calculation of weight corresponding to each quality characteristic. The results indicate that the hybrid approaches applied for modelling and optimization of the LBC process are reasonable.

Neodymium:YAG laser cutting of intraocular lens haptics.

Science.gov (United States)

Gorn, R A; Steinert, R F

1985-11-01

Neodymium:YAG laser cutting of polymethylmethacrylate and polypropylene anterior chamber and posterior chamber intraocular lens haptics was studied in terms of ease of transection and physical structure of the cut areas as seen by scanning electron microscopy. A marked difference was discovered, with the polymethylmethacrylate cutting easily along transverse planes, whereas the polypropylene resisted cutting along longitudinal fibers. Clinical guidelines are presented.

Automated Cell-Cutting for Cell Cloning

Science.gov (United States)

Ichikawa, Akihiko; Tanikawa, Tamio; Matsukawa, Kazutsugu; Takahashi, Seiya; Ohba, Kohtaro

We develop an automated cell-cutting technique for cell cloning. Animal cells softened by the cytochalasin treatment are injected into a microfluidic chip. The microfluidic chip contains two orthogonal channels: one microchannel is wide, used to transport cells, and generates the cutting flow; the other is thin and used for aspiration, fixing, and stretching of the cell. The injected cell is aspirated and stretched in the thin microchannel. Simultaneously, the volumes of the cell before and after aspiration are calculated; the volumes are used to calculate the fluid flow required to aspirate half the volume of the cell into the thin microchannel. Finally, we apply a high-speed flow in the orthogonal microchannel to bisect the cell. This paper reports the cutting process, the cutting system, and the results of the experiment.

Benefits of explosive cutting for nuclear-facility applications

International Nuclear Information System (INIS)

Hazelton, R.F.; Lundgren, R.A.; Allen, R.P.

1981-06-01

The study discussed in this report was a cost/benefit analysis to determine: (1) whether explosive cutting is cost effective in comparison with alternative metal sectioning methods and (2) whether explosive cutting would reduce radiation exposure or provide other benefits. Two separate approaches were pursued. The first was to qualitatively assess cutting methods and factors involved in typical sectioning cases and then compare the results for the cutting methods. The second was to prepare estimates of work schedules and potential radiation exposures for candidate sectioning methods for two hypothetical, but typical, sectioning tasks. The analysis shows that explosive cutting would be cost effective and would also reduce radiation exposure when used for typical nuclear facility sectioning tasks. These results indicate that explosive cutting should be one of the principal cutting methods considered whenever steel or similar metal structures or equipment in a nuclear facility are to be sectioned for repair or decommissioning. 13 figures, 7 tables

Budget Cuts: Financial Aid Offices Face Budget Cuts and Increasing Workload. Quick Scan Survey Results

Science.gov (United States)

National Association of Student Financial Aid Administrators (NJ1), 2010

2010-01-01

The majority of college financial aid offices have seen cuts to their operating budgets this year compared to the 2007-08 academic year when the recession began, according to the National Association of Student Financial Aid Administrator's latest QuickScan Survey. Sixty-two percent of financial aid offices reported operating budget cuts this year…

Cut elimination in multifocused linear logic

DEFF Research Database (Denmark)

Guenot, Nicolas; Brock-Nannestad, Taus

2015-01-01

We study cut elimination for a multifocused variant of full linear logic in the sequent calculus. The multifocused normal form of proofs yields problems that do not appear in a standard focused system, related to the constraints in grouping rule instances in focusing phases. We show that cut...... elimination can be performed in a sensible way even though the proof requires some specific lemmas to deal with multifocusing phases, and discuss the difficulties arising with cut elimination when considering normal forms of proofs in linear logic....

Application of response surface methodology for determining cutting ...

Indian Academy of Sciences (India)

The results indicate that the depth of cut is the dominant factor affecting cutting ... between forces and cutting regime could be represented by power function type ..... CNEPRU Research Project, CODE : 0301520090008 (University of Guelma).

Thermophysical problems of laser cutting of metals

Directory of Open Access Journals (Sweden)

Orishich Anatoliy

2017-01-01

Full Text Available Variety and complex interaction of physical processes during laser cutting is a critical characteristic of the laser cutting of metals. Small spatial and temporal scales complicate significantly the experimental investigations of the multi-phase fluid flow in the conditions of laser cutting of metals. In these conditions, the surface formed during the cutting is an indicator determining the melt flow character. The quantitative parameter reflecting the peculiarities of the multi-phase fluid flow, is normally the roughness of the forming surface, and the minimal roughness is the criterion of the qualitative flow [1 – 2]. The purpose of this work is to perform the experimental comparative investigation of the thermophysical pattern of the multi-phase melt flow in the conditions of the laser cutting of metals with the laser wavelength of 10.6 μm and 1.07 μm.

Fractal characteristic study of shearer cutter cutting resistance curves

Energy Technology Data Exchange (ETDEWEB)

Liu, C. [Heilongjiang Scientific and Technical Institute, Haerbin (China). Dept of Mechanical Engineering

2004-02-01

The cutting resistance curve is the most useful tool for reflecting the overall cutting performance of a cutting machine. The cutting resistance curve is influenced by many factors such as the pick structure and arrangement, the cutter operation parameters, coal quality and geologic conditions. This paper discusses the use of fractal geometry to study the properties of the cutting resistance curve, and the use of fractal dimensions to evaluate cutting performance. On the basis of fractal theory, the general form and calculation method of fractal characteristics are given. 4 refs., 3 figs., 1 tab.

Effect of cutting temperature on hardness of SiC and diamond in the nano-cutting process of monocrystalline silicon

Science.gov (United States)

Wang, Jiachun; Li, Yuntao; Liu, Xiaoxuan; Lv, Maoqiang

2016-10-01

In the process of cutting silicon by natural diamond tools, groove wear happens on the flank face of cutting tool frequently.Scholars believe that one of the wear reasons is mechanical scratching effect by hard particles like SiC. To reveal the mechanical scratching mechanism, it is essential to study changes in the mechanical properties of hard particles and diamond, especially the effect of cutting temperature on hardness of diamond and hard particles. Molecular dynamics (MD) model that contact-zone temperature between tool and workpiece was calculated by dividing zone while nano-cutting monocrystalline silicon was established, cutting temperature values in different regions were computed as the simulation was carried out.On this basis, the models of molecular dynamics simulation of SiC and diamond were established separately with setting the initial temperature to room temperature. The laws of length change of C-C bond and Si-C bond varing with increase of simulation temperature were studied. And drawing on predecessors' research on theoretical calculation of hardness of covalent crystals and the relationship between crystal valence electron density and bond length, the curves that the hardness of diamond and SiC varing with bond length were obtained. The effect of temperature on the hardness was calculated. Results show that, local cutting temperature can reach 1300K.The rise in cutting temperature leaded to a decrease in the diamond local atomic clusters hardness,SiC local atomic clusters hardness increased. As the cutting temperature was more than 1100K,diamond began to soften, the local clusters hardness was less than that of SiC.

Recent results in mirror based high power laser cutting

DEFF Research Database (Denmark)

Olsen, Flemming Ove; Nielsen, Jakob Skov; Elvang, Mads

2004-01-01

In this paper, recent results in high power laser cutting, obtained in reseach and development projects are presented. Two types of mirror based focussing systems for laser cutting have been developed and applied in laser cutting studies on CO2-lasers up to 12 kW. In shipyard environment cutting...... speed increase relative to state-of-the-art cutting of over 100 % has been achieved....

Magnetofluidic testing of rock cutting knives

International Nuclear Information System (INIS)

Buioca, C.D.; Iusan, Vasile; Pirlea, Remus

2002-01-01

The nondestructive testing of cutting knives consists in the determination of nonuniformity of a magnetic fluid layer applied on the horizontally placed surface of the magnetized cutting plate of the knife. A low constant magnetic field was applied perpendicular to the knife surface and a uniform magnetic fluid layer was applied. The defects as nonuniform brass layer, fissures or small cavities between the cutting plate and knife core determine the apparition of magnetic field gradients and therefore magnetic forces acting on the magnetic fluid which migrates to the zones with higher magnetic field intensity. After several minutes, a nonuniform layer of magnetic fluid was directly observed. Quantitative results, concerning the position and dimensions of the defect, were obtained by computer aided processing of the magnetic fluid layer image. Experimental data for several cutting knives are presented in the paper

Laser cutting - from 200 Watt to 12 Kilowatt

DEFF Research Database (Denmark)

Olsen, Flemming Ove; Nielsen, Jakob Skov

2004-01-01

Laser cutting is the most widespread industrial application of high power lasers. The development of this process was initiated around 1970, when scientists at TWI first demonstrated laser cutting with coaxial gas assistance. 10 years later, the polarisation problem was solved and the technology ...... got its breakthrough. Since then some 30,000 laser cutting systems have been installed worldwide, making the laser an important cutting tool in modern industry....

Investigation of tool engagement and cutting performance in machining a pocket

Science.gov (United States)

Adesta, E. Y. T.; Hamidon, R.; Riza, M.; Alrashidi, R. F. F. A.; Alazemi, A. F. F. S.

2018-01-01

This study investigates the variation of tool engagement for different profile of cutting. In addition, behavior of cutting force and cutting temperature for different tool engagements for machining a pocket also been explored. Initially, simple tool engagement models were developed for peripheral and slot cutting for different types of corner. Based on these models, the tool engagements for contour and zig zag tool path strategies for a rectangular shape pocket with dimension 80 mm x 60 mm were analyzed. Experiments were conducted to investigate the effect of tool engagements on cutting force and cutting temperature for the machining of a pocket of AISI H13 material. The cutting parameters used were 150m/min cutting speed, 0.05mm/tooth feed, and 0.1mm depth of cut. Based on the results obtained, the changes of cutting force and cutting temperature performance there exist a relationship between cutting force, cutting temperature and tool engagement. A higher cutting force and cutting temperature is obtained when the cutting tool goes through up milling and when the cutting tool makes a full engagement with the workpiece.

Influences of Cutting Speed and Material Mechanical Properties on Chip Deformation and Fracture during High-Speed Cutting of Inconel 718

Directory of Open Access Journals (Sweden)

Bing Wang

2018-03-01

Full Text Available The paper aims to investigate the influences of material constitutive and fracture parameters in addition to cutting speed on chip formation during high-speed cutting of Inconel 718. Finite element analyses for chip formation are conducted with Johnson–Cook constitutive and fracture models. Meanwhile, experiments of high-speed orthogonal cutting are performed to verify the simulation results with cutting speeds ranging from 50 m/min to 7000 m/min. The research indicates that the chip morphology transforms from serrated to fragmented at the cutting speed of 7000 m/min due to embrittlement of the workpiece material under ultra-high cutting speeds. The parameter of shear localization sensitivity is put forward to describe the influences of material mechanical properties on serrated chip formation. The results demonstrate that the effects of initial yield stress and thermal softening coefficient on chip shear localization are much more remarkable than the other constitutive parameters. For the material fracture parameters, the effects of initial fracture strain and exponential factor of stress state on chip shear localization are more much prominent. This paper provides guidance for controlling chip formation through the adjustment of material mechanical properties and the selection of appropriate cutting parameters.

Influences of Cutting Speed and Material Mechanical Properties on Chip Deformation and Fracture during High-Speed Cutting of Inconel 718.

Science.gov (United States)

Wang, Bing; Liu, Zhanqiang; Hou, Xin; Zhao, Jinfu

2018-03-21

The paper aims to investigate the influences of material constitutive and fracture parameters in addition to cutting speed on chip formation during high-speed cutting of Inconel 718. Finite element analyses for chip formation are conducted with Johnson-Cook constitutive and fracture models. Meanwhile, experiments of high-speed orthogonal cutting are performed to verify the simulation results with cutting speeds ranging from 50 m/min to 7000 m/min. The research indicates that the chip morphology transforms from serrated to fragmented at the cutting speed of 7000 m/min due to embrittlement of the workpiece material under ultra-high cutting speeds. The parameter of shear localization sensitivity is put forward to describe the influences of material mechanical properties on serrated chip formation. The results demonstrate that the effects of initial yield stress and thermal softening coefficient on chip shear localization are much more remarkable than the other constitutive parameters. For the material fracture parameters, the effects of initial fracture strain and exponential factor of stress state on chip shear localization are more much prominent. This paper provides guidance for controlling chip formation through the adjustment of material mechanical properties and the selection of appropriate cutting parameters.

Underwater transporting method and device for incore structure cutting piece

International Nuclear Information System (INIS)

Kurosawa, Koichi; Chiba, Noboru; Chiba, Isao; Takada, Hiroshi; Furukawa, Hideyasu; Chiba, Noboru.

1996-01-01

Cutting pieces are handled by using a pick-up device connected with a wire ropes, a take-up drum, chains and a winch as cutting piece handling means, and moved freely on the water surface by a propulsion machine of a transporting means of the device to transfer them under water to a predetermined position. The pick-up device is lifted by taking-up the rope by the rotation of the take-up drum using chain-driving by way of the winch and the chains. The cut pieces are stored in a cask by lowering them in the cask and releasing the handling. In addition, if the weight of the cut pieces is recognized before cutting, and the load of the weight of the cut pieces is applied to the device previously, the balance of the device and the cut pieces can be kept, and cut pieces can be transported under water always stably. Further, if the cut pieces are supported upon cutting operation, the cut pieces are made stable, and cutting operation with good efficiency can be attained. (N.H.)

Counterbalance of cutting force for advanced milling operations

Science.gov (United States)

Tsai, Nan-Chyuan; Shih, Li-Wen; Lee, Rong-Mao

2010-05-01

The goal of this work is to concurrently counterbalance the dynamic cutting force and regulate the spindle position deviation under various milling conditions by integrating active magnetic bearing (AMB) technique, fuzzy logic algorithm and an adaptive self-tuning feedback loop. Since the dynamics of milling system is highly determined by a few operation conditions, such as speed of spindle, cut depth and feedrate, therefore the dynamic model for cutting process is more appropriate to be constructed by experiments, instead of using theoretical approach. The experimental data, either for idle or cutting, are utilized to establish the database of milling dynamics so that the system parameters can be on-line estimated by employing the proposed fuzzy logic algorithm as the cutting mission is engaged. Based on the estimated milling system model and preset operation conditions, i.e., spindle speed, cut depth and feedrate, the current cutting force can be numerically estimated. Once the current cutting force can be real-time estimated, the corresponding compensation force can be exerted by the equipped AMB to counterbalance the cutting force, in addition to the spindle position regulation by feedback of spindle position. On the other hand, for the magnetic force is nonlinear with respect to the applied electric current and air gap, the characteristics of the employed AMB is investigated also by experiments and a nonlinear mathematic model, in terms of air gap between spindle and electromagnetic pole and coil current, is developed. At the end, the experimental simulations on realistic milling are presented to verify the efficacy of the fuzzy controller for spindle position regulation and the capability of the dynamic cutting force counterbalance.

Metal Cutting for Large Component Removal

International Nuclear Information System (INIS)

Hulick, Robert M.

2008-01-01

Decommissioning of commercial nuclear power plants presents technological challenges. One major challenge is the removal of large components mainly consisting of the reactor vessel, steam generators and pressurizer. In order to remove and package these large components nozzles must be cut from the reactor vessel to precise tolerances. In some cases steam generators must be segmented for size and weight reduction. One innovative technology that has been used successfully at several commercial nuclear plant decommissioning is diamond wire sawing. Diamond wire sawing is performed by rotating a cable with diamond segments attached using a flywheel approximately 24 inches in diameter driven remotely by a hydraulic pump. Tension is provided using a gear rack drive which also takes up the slack in the wire. The wire is guided through the use of pulleys keeps the wire in a precise location. The diamond wire consists of 1/4 inch aircraft cable with diamond beads strung over the cable separated by springs and brass crimps. Standard wire contains 40 diamond beads per meter and can be made to any length. Cooling the wire and controlling the spread of contamination presents significant challenges. Under normal circumstances the wire is cooled and the cutting kerf cleaned by using water. In some cases of reactor nozzle cuts the use of water is prohibited because it cannot be controlled. This challenge was solved by using liquid Carbon Dioxide as the cooling agent. The liquid CO 2 is passed through a special nozzle which atomizes the liquid into snowflakes which is introduced under pressure to the wire. The snowflakes attach to the wire keeping it cool and to the metal shavings. As the CO 2 and metal shavings are released from the wire due to its fast rotation, the snowflakes evaporate leaving only the fine metal shavings as waste. Secondary waste produced is simply the small volume of fine metal shavings removed from the cut surface. Diamond wire sawing using CO 2 cooling has

Cutting of nonmetallic materials using Nd:YAG laser beam

Institute of Scientific and Technical Information of China (English)

Bashir Ahmed Tahir; Rashid Ahmed; M. G. B. Ashiq; Afaq Ahmed; M. A. Saeed

2012-01-01

This study deals with Nd:YAG laser cutting nonmetallic materials,which is one of the most important and popular industrial applications of laser.The main theme is to evaluate the effects of Nd:YAG laser beam power besides work piece scanning speed.For approximate cutting depth,a theoretical study is conducted in terms of material property and cutting speed.Results show a nonlinear relation between the cutting depth and input energy.There is no significant effect of speed on cutting depth with the speed being larger than 30 mm/s.An extra energy is utilized in the deep cutting.It is inferred that as the laser power increases,cutting depth increases.The experimental outcomes are in good agreement with theoretical results.This analysis will provide a guideline for laser-based industry to select a suitable laser for cutting,scribing,trimming,engraving,and marking nonmetallic materials.

Effect of cutting fluids and cutting conditions on surface integrity and tool wear in turning of Inconel 713C

Science.gov (United States)

Hikiji, R.

2018-01-01

The trend toward downsizing of engines helps to increase the number of turbochargers around Europe. As for the turbocharger, the temperature of the exhaust gas is so high that the parts made of nickel base super alloy Inconel 713C are used as high temperature strength metals. External turning of Inconel 713C which is used as the actual automotive parts was carried out. The effect of the cutting fluids and cutting conditions on the surface integrity and tool wear was investigated, considering global environment and cost performance. As a result, in the range of the cutting conditions used this time, when the depth of cut was small, the good surface integrity and tool life were obtained. However, in the case of the large corner radius, it was found that the more the cutting length increased, the more the tool wear increased. When the cutting length is so large, the surface integrity and tool life got worse. As for the cutting fluids, it was found that the synthetic type showed better performance in the surface integrity and tool life than the conventional emulsion. However, it was clear that the large corner radius made the surface roughness and tool life good, but it affected the size error etc. in machining the workpiece held in a cantilever style.

MULTI-OBJECTIVE OPTIMISATION OF LASER CUTTING USING CUCKOO SEARCH ALGORITHM

Directory of Open Access Journals (Sweden)

M. MADIĆ

2015-03-01

Full Text Available Determining of optimal laser cutting conditions for improving cut quality characteristics is of great importance in process planning. This paper presents multi-objective optimisation of the CO2 laser cutting process considering three cut quality characteristics such as surface roughness, heat affected zone (HAZ and kerf width. It combines an experimental design by using Taguchi’s method, modelling the relationships between the laser cutting factors (laser power, cutting speed, assist gas pressure and focus position and cut quality characteristics by artificial neural networks (ANNs, formulation of the multiobjective optimisation problem using weighting sum method, and solving it by the novel meta-heuristic cuckoo search algorithm (CSA. The objective is to obtain optimal cutting conditions dependent on the importance order of the cut quality characteristics for each of four different case studies presented in this paper. The case studies considered in this study are: minimisation of cut quality characteristics with equal priority, minimisation of cut quality characteristics with priority given to surface roughness, minimisation of cut quality characteristics with priority given to HAZ, and minimisation of cut quality characteristics with priority given to kerf width. The results indicate that the applied CSA for solving the multi-objective optimisation problem is effective, and that the proposed approach can be used for selecting the optimal laser cutting factors for specific production requirements.

ANALYSIS OF CUTTING FORCES ON CNC LATHES EXPERIMENTAL APPROACH

Directory of Open Access Journals (Sweden)

Erdem Koç

1996-01-01

Full Text Available Objective of this study is to make use easy programming of CNC lathes and to achieve the optimization of part program prepared considering the limiting parameters of the machine. In the present study, a BOXFORD 250 B CNC lathe has been used for experiment and optimization process. The measurement of cutting forces exerted on the cutting tool of CNC lathe has been performed. The cutting forces occurring during the turning operation have been determined for different depth of" cut, feed rate and cutting speed as well as different cutting tools and related data base has been obtained.

Ceramic cutting tools materials, development and performance

CERN Document Server

Whitney, E Dow

1994-01-01

Interest in ceramics as a high speed cutting tool material is based primarily on favorable material properties. As a class of materials, ceramics possess high melting points, excellent hardness and good wear resistance. Unlike most metals, hardness levels in ceramics generally remain high at elevated temperatures which means that cutting tip integrity is relatively unaffected at high cutting speeds. Ceramics are also chemically inert against most workmetals.

Precision Machining When Cutting with Leading Plastic Deformation

Directory of Open Access Journals (Sweden)

N. A. Yaroslavtseva

2017-01-01

Full Text Available Keeping up the product competitiveness continually requires solving the problems of reducing time for product creation and material costs for its production and ensuring the maximum conformity of the product quality with the individual requirements of a particular consumer. It is especially difficult to implement these tasks in product manufacturing from the hard-to-machine steels and alloys with extremely low production rate in machining (often 10-20 times lower than when cutting the ordinary structural steels.Currently, one of the promising ways to improve the cutting process of hard-to-machine materials and quality of parts made from these materials is development and application of combined processing methods, which use additional energy sources to act on the machined material in the cutting zone. A BMSTU-developed cutting method with leading plastic deformation (LPD, which acts to raise the production rate, gain the cutting tool-life, reduce the surface roughness, improve the accuracy of processing and the performance characteristics of products, ensure the reliable flow chip control, and improve the labor conditions, belongs to such sort of methods.One of the most important indicators of processing quality that has a great impact on the operation and cost characteristics of the product and on the machining rate as well is the accuracy of processing. In cutting, the processing errors largely arise from the elastic deformations of a technological system when the cutting force, and, in particular, the radial component of the cutting force, acts on it.The deforming devices, used in cutting with LPD, being located as a rule, on the diametrically opposite side with respect to the cutting zone, act on the technological system as vibration dampers. In addition, as studies have shown, the choice of a rational direction for applying LPD load helps to compensate partially or completely the cutting force radial component effect on the technological

Long-term effects of clear-cutting and selective cutting on soil methane fluxes in a temperate spruce forest in southern Germany

International Nuclear Information System (INIS)

Wu Xing; Brueggemann, Nicolas; Gasche, Rainer; Papen, Hans; Willibald, Georg; Butterbach-Bahl, Klaus

2011-01-01

Based on multi-year measurements of CH 4 exchange in sub-daily resolution we show that clear-cutting of a forest in Southern Germany increased soil temperature and moisture and decreased CH 4 uptake. CH 4 uptake in the first year after clear-cutting (-4.5 ± 0.2 μg C m -2 h -1 ) was three times lower than during the pre-harvest period (-14.2 ± 1.3 μg C m -2 h -1 ). In contrast, selective cutting did not significantly reduce CH 4 uptake. Annual mean uptake rates were -1.18 kg C ha -1 yr -1 (spruce control), -1.16 kg C ha -1 yr -1 (selective cut site) and -0.44 kg C ha -1 yr -1 (clear-cut site), respectively. Substantial seasonal and inter-annual variations in CH 4 fluxes were observed as a result of significant variability of weather conditions, demonstrating the need for long-term measurements. Our findings imply that a stepwise selective cutting instead of clear-cutting may contribute to mitigating global warming by maintaining a high CH 4 uptake capacity of the soil. - Highlights: → Long-term, sub-daily measurements of CH 4 exchange at differently managed forest sites. → Inter-annual variability in CH 4 uptake is affected by annual precipitation. → Clear-cutting reduces the CH 4 sink strength of forest soils, whereas thinning has no significant effect. → Sink strength changes due to clear cutting are long-term and were still present approx. nine years following forest harvest. - Forest management affects the soil CH 4 sink strength, with clear-cutting reducing uptake rates for at least eight years.

Non-Poissonian photon statistics from macroscopic photon cutting materials.

Science.gov (United States)

de Jong, Mathijs; Meijerink, Andries; Rabouw, Freddy T

2017-05-24

In optical materials energy is usually extracted only from the lowest excited state, resulting in fundamental energy-efficiency limits such as the Shockley-Queisser limit for single-junction solar cells. Photon-cutting materials provide a way around such limits by absorbing high-energy photons and 'cutting' them into multiple low-energy excitations that can subsequently be extracted. The occurrence of photon cutting or quantum cutting has been demonstrated in a variety of materials, including semiconductor quantum dots, lanthanides and organic dyes. Here we show that photon cutting results in bunched photon emission on the timescale of the excited-state lifetime, even when observing a macroscopic number of optical centres. Our theoretical derivation matches well with experimental data on NaLaF 4 :Pr 3+ , a material that can cut deep-ultraviolet photons into two visible photons. This signature of photon cutting can be used to identify and characterize new photon-cutting materials unambiguously.

Cutting of nonmetallic materials using Nd:YAG laser beam

International Nuclear Information System (INIS)

Tahir, Bashir Ahmed; Ashiq, M.G. B.; Saeed, M.A.; Ahmed, Rashid; Ahmed, Afaq

2012-01-01

This study deals with Nd:YAG laser cutting nonmetallic materials, which is one of the most important and popular industrial applications of laser. The main theme is to evaluate the effects of Nd:YAG laser beam power besides work piece scanning speed. For approximate cutting depth, a theoretical study is conducted in terms of material property and cutting speed. Results show a nonlinear relation between the cutting depth and input energy. There is no significant effect of speed on cutting depth with the speed being larger than 30 mm/s. An extra energy is utilized in the deep cutting. It is inferred that as the laser power increases, cutting depth increases. The experimental outcomes are in good agreement with theoretical results. This analysis will provide a guideline for laser-based industry to select a suitable laser for cutting, scribing, trimming, engraving, and marking nonmetallic materials. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Remotely controlled cutting techniques in the field of nuclear decommissioning. Overview of effectively applied thermal and non thermal cutting methods

International Nuclear Information System (INIS)

Bienia, H.

2008-01-01

Remote disassembly of radiologically burdened large components is among the most sophisticated and complex activities in the dismantling of nuclear installations. The required space for the technical equipment during the dismantling operations, especially for the removal of larger components is often an additional problem. Conventional cutting technologies like sawing with a disk saw or band saw require large and heavy frameworks as well as guiding systems with high rigidity. These solutions are expensive and sometimes not applicable. The essential question of all cutting and dismantling tasks is the physiological constitution of the component which will be dismantled. That means size, material and structure of the component. All these points are primarily technological questions. The last question is about the estimated costs of the used dismantling technology. Therefore following questions must be answered. How much are the investments for the cutting equipment itself and how much are the investments for the supporting equipment (e.g. necessary handling equipment)? Can I use this cutting equipment only for one special task or is it applicable for many tasks and therefore saves money because other cutting or dismantling technologies are dispensable? How long is the cutting time and what is the to control this technique required personnel? Four different cutting and dismantling technologies will be introduced and described. These four technologies differ in their principle of operation but all of them are used by cutting and dismantling tasks in nuclear power plants. (author)

Analyses of Effects of Cutting Parameters on Cutting Edge Temperature Using Inverse Heat Conduction Technique

Directory of Open Access Journals (Sweden)

Marcelo Ribeiro dos Santos

2014-01-01

Full Text Available During machining energy is transformed into heat due to plastic deformation of the workpiece surface and friction between tool and workpiece. High temperatures are generated in the region of the cutting edge, which have a very important influence on wear rate of the cutting tool and on tool life. This work proposes the estimation of heat flux at the chip-tool interface using inverse techniques. Factors which influence the temperature distribution at the AISI M32C high speed steel tool rake face during machining of a ABNT 12L14 steel workpiece were also investigated. The temperature distribution was predicted using finite volume elements. A transient 3D numerical code using irregular and nonstaggered mesh was developed to solve the nonlinear heat diffusion equation. To validate the software, experimental tests were made. The inverse problem was solved using the function specification method. Heat fluxes at the tool-workpiece interface were estimated using inverse problems techniques and experimental temperatures. Tests were performed to study the effect of cutting parameters on cutting edge temperature. The results were compared with those of the tool-work thermocouple technique and a fair agreement was obtained.

Equilibrium Analysis in Cake Cutting

DEFF Research Database (Denmark)

Branzei, Simina; Miltersen, Peter Bro

2013-01-01

Cake cutting is a fundamental model in fair division; it represents the problem of fairly allocating a heterogeneous divisible good among agents with different preferences. The central criteria of fairness are proportionality and envy-freeness, and many of the existing protocols are designed...... to guarantee proportional or envy-free allocations, when the participating agents follow the protocol. However, typically, all agents following the protocol is not guaranteed to result in a Nash equilibrium. In this paper, we initiate the study of equilibria of classical cake cutting protocols. We consider one...... of the simplest and most elegant continuous algorithms -- the Dubins-Spanier procedure, which guarantees a proportional allocation of the cake -- and study its equilibria when the agents use simple threshold strategies. We show that given a cake cutting instance with strictly positive value density functions...

Reachability cuts for the vehicle routing problem with time windows

DEFF Research Database (Denmark)

Lysgaard, Jens

2004-01-01

This paper introduces a class of cuts, called reachability cuts, for the Vehicle Routing Problem with Time Windows (VRPTW). Reachability cuts are closely related to cuts derived from precedence constraints in the Asymmetric Traveling Salesman Problem with Time Windows and to k-path cuts...

Cutting weeds with a CO2 laser

DEFF Research Database (Denmark)

Heisel, T.; Schou, Jørgen; Christensen, S.

2001-01-01

Stems of Chenopodium album. and Sinapis arvensis. and leaves of Lolium perenne. were cut with a CO2 laser or with a pair of scissors. Treatments were carried out on greenhouse-grown pot plants at three different growth stages and at two heights. Plant dry matter was measured 2 to 5 weeks after...... treatment. The relationship between dry weight and laser energy was analysed using a non-linear dose-response regression model. The regression parameters differed significantly between the weed species. At all growth stages and heights S. arvensis was more difficult to cut with a CO2 laser than C. album....... When stems were cut below the meristems, 0.9 and 2.3 J mm(-1) of CO2 laser energy dose was sufficient to reduce by 90% the biomass of C. album and S. arvensis respectively. Regrowth appeared when dicotyledonous plant stems were cut above meristems, indicating that it is important to cut close...

ADVANCED CUTTINGS TRANSPORT STUDY

Energy Technology Data Exchange (ETDEWEB)

Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Len Volk; Mark Pickell; Evren Ozbayoglu; Barkim Demirdal; Paco Vieira; Affonso Lourenco

1999-10-15

This report includes a review of the progress made in ACTF Flow Loop development and research during 90 days pre-award period (May 15-July 14, 1999) and the following three months after the project approval date (July15-October 15, 1999) The report presents information on the following specific subjects; (a) Progress in Advanced Cuttings Transport Facility design and development, (b) Progress report on the research project ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (c) Progress report on the research project ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (d) Progress report on the research project ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (e) Progress report on the research project ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Progress report on the instrumentation tasks (Tasks 11 and 12) (g) Activities towards technology transfer and developing contacts with oil and service company members.

High speed cutting of AZ31 magnesium alloy

Directory of Open Access Journals (Sweden)

Liwei Lu

2016-06-01

Full Text Available Using LBR-370 numerical control lathe, high speed cutting was applied to AZ31 magnesium alloy. The influence of cutting parameters on microstructure, surface roughness and machining hardening were investigated by using the methods of single factor and orthogonal experiment. The results show that the cutting parameters have an important effect on microstructure, surface roughness and machine hardening. The depth of stress layer, roughness and hardening present a declining tendency with the increase of the cutting speed and also increase with the augment of the cutting depth and feed rate. Moreover, we established a prediction model of the roughness, which has an important guidance on actual machining process of magnesium alloy.

Striation-free fibre laser cutting of mild steel sheets

Energy Technology Data Exchange (ETDEWEB)

Sobih, M.; Crouse, P.L.; Li, L. [University of Manchester, Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, Sackville Street Building, P.O. Box 88, Manchester (United Kingdom)

2008-01-15

High-power laser cutting is extensively used in many industrial applications. An important weakness of this process is the formation of striations, i.e. regular lines on the cut surface, which lowers the quality of the surfaces produced. The elimination of striation formation is thus of considerable importance, since it could open a variety of novel high-precision applications. This study presents the initial results of a laser cutting study using a 1 kW single-mode fibre laser, a relative newcomer in the field of laser metal cutting. Striation-free laser cuts are demonstrated when cutting 1 mm thick mild steel sheets. (orig.)

The Role of Quantifier Alternations in Cut Elimination

DEFF Research Database (Denmark)

Gerhardy, Philipp

2005-01-01

Extending previous results on the complexity of cut elimination for the sequent calculus LK, we discuss the role of quantifier alternations and develop a measure to describe the complexity of cut elimination in terms of quantifier alternations in cut formulas and contractions on such formulas...

Study of AFM-based nanometric cutting process using molecular dynamics

International Nuclear Information System (INIS)

Zhu Pengzhe; Hu Yuanzhong; Ma Tianbao; Wang Hui

2010-01-01

Three-dimensional molecular dynamics (MD) simulations are conducted to investigate the atomic force microscope (AFM)-based nanometric cutting process of copper using diamond tool. The effects of tool geometry, cutting depth, cutting velocity and bulk temperature are studied. It is found that the tool geometry has a significant effect on the cutting resistance. The friction coefficient (cutting resistance) on the nanoscale decreases with the increase of tool angle as predicted by the macroscale theory. However, the friction coefficients on the nanoscale are bigger than those on the macroscale. The simulation results show that a bigger cutting depth results in more material deformation and larger chip volume, thus leading to bigger cutting force and bigger normal force. It is also observed that a higher cutting velocity results in a larger chip volume in front of the tool and bigger cutting force and normal force. The chip volume in front of the tool increases while the cutting force and normal force decrease with the increase of bulk temperature.

Development of cutting techniques of steel pipe by wire sawing

International Nuclear Information System (INIS)

Kamiyama, Yoshinori; Inai, Shinsuke

2004-01-01

A cutting method has a high cutting efficiency and enable cutting in safe. A wire saw cutting method is used for dismantling of massive concrete structures such as nuclear power plants with an effective and safe mean. In the case of dismantling of structures with multiple pipes installed at these facilities, an effective method is also demanded. If a wire saw method to remotely cut target objects in a large block in bulk is applicable, it will be expected an effective dismantling work under severe conditions with radioactivity. Although the wire saw method has adaptability for any shapes of cutting target objects and is widely adopted in dismantling of concrete constructs, it has few actual achievements in dismantling of steel structures such as steel pipe bundle. This study aims to verify its cutting characteristics and adaptability as a cutting method by conducting a cutting basic test to develop a diamond wire saw method to efficiently cut constructs with multiple pipes in a bundle. The test proved that a wire saw cutting method apply to dismantle structures with steel pipe bundle. A wire saw for metal cutting is adaptable in dismantling of bundle of thick carbon steel and stainless steel pipes. And also a wire saw for concrete cutting is adaptable in dismantling of pipe bundle structure with a mortar. (author)

Descriptive Analysis of In Vitro Cutting of Swine Mitral Cusps: Comparison of High-Power Laser and Scalpel Blade Cutting Techniques.

Science.gov (United States)

Pinto, Nathali Cordeiro; Pomerantzeff, Pablo Maria Alberto; Deana, Alessandro; Zezell, Denise; Benetti, Carolina; Aiello, Vera Demarchi; Lopes, Luciana Almeida; Jatene, Fabio Biscegli; Chavantes, M Cristina

2017-02-01

The most common injury to the heart valve with rheumatic involvement is mitral stenosis, which is the reason for a big number of cardiac operations in Brazil. Commissurotomy is the traditional technique that is still widely used for this condition, although late postoperative restenosis is concerning. This study's purpose was to compare the histological findings of porcine cusp mitral valves treated in vitro with commissurotomy with a scalpel blade to those treated with high-power laser (HPL) cutting, using appropriate staining techniques. Five mitral valves from healthy swine were randomly divided into two groups: Cusp group (G1), cut with a scalpel blade (n = 5), and Cusp group (G2), cut with a laser (n = 5). G2 cusps were treated using a diode laser (λ = 980 nm, power = 9.0 W, time = 12 sec, irradiance = 5625 W/cm 2 , and energy = 108 J). In G1, no histological change was observed in tissue. A hyaline basophilic aspect was focally observed in G2, along with a dark red color on the edges and areas of lower birefringence, when stained with hematoxylin-eosin, Masson's trichrome, and Sirius red. Further, the mean distances from the cutting edge in cusps submitted to laser application and stained with Masson's trichrome and Sirius red were 416.7 and 778.6 μm, respectively, never overcoming 1 mm in length. Thermal changes were unique in the group submitted to HPL and not observed in the cusp group cut with a scalpel blade. The mean distance of the cusps' collagen injury from the cutting edge was less than 1 mm with laser treatment. Additional studies are needed to establish the histological evolution of the laser cutting and to answer whether laser cutting may avoid valvular restenosis better than blade cutting.

Leaf processing behaviour in Atta leafcutter ants: 90% of leaf cutting takes place inside the nest, and ants select pieces that require less cutting.

Science.gov (United States)

Garrett, Ryan W; Carlson, Katherine A; Goggans, Matthew Scott; Nesson, Michael H; Shepard, Christopher A; Schofield, Robert M S

2016-01-01

Leafcutter ants cut trimmings from plants, carry them to their underground nests and cut them into smaller pieces before inoculating them with a fungus that serves as a primary food source for the colony. Cutting is energetically costly, so the amount of cutting is important in understanding foraging energetics. Estimates of the cutting density, metres of cutting per square metre of leaf, were made from samples of transported leaf cuttings and of fungal substrate from field colonies of Atta cephalotes and Atta colombica. To investigate cutting inside the nest, we made leaf-processing observations of our laboratory colony, A. cephalotes. We did not observe the commonly reported reduction of the leaf fragments into a pulp, which would greatly increase the energy cost of processing. Video clips of processing behaviours, including behaviours that have not previously been described, are linked. An estimated 2.9 (±0.3) km of cutting with mandibles was required to reduce a square metre of leaf to fungal substrate. Only about 12% (±1%) of this cutting took place outside of the nest. The cutting density and energy cost is lower for leaf material with higher ratios of perimeter to area, so we tested for, and found that the laboratory ants had a preference for leaves that were pre-cut into smaller pieces. Estimates suggest that the energy required to transport and cut up the leaf material is comparable to the metabolic energy available from the fungus grown on the leaves, and so conservation of energy is likely to be a particularly strong selective pressure for leafcutter ants.

ADVANCED CUTTINGS TRANSPORT STUDY

Energy Technology Data Exchange (ETDEWEB)

Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Neelima Godugu

2000-07-30

ACTS flow loop is now operational under elevated pressure and temperature. Currently, experiments with synthetic based drilling fluids under pressure and temperature are being conducted. Based on the analysis of Fann 70 data, empirical correlations defining the shear stress as a function of temperature, pressure and the shear rate have been developed for Petrobras synthetic drilling fluids. PVT equipment has been modified for testing Synthetic oil base drilling fluids. PVT tests with Petrobras Synthetic base mud have been conducted and results are being analyzed Foam flow experiments have been conducted and the analysis of the data has been carried out to characterize the rheology of the foam. Comparison of pressure loss prediction from the available foam hydraulic models and the test results has been made. Cuttings transport experiments in horizontal annulus section have been conducted using air, water and cuttings. Currently, cuttings transport tests in inclined test section are being conducted. Foam PVT analysis tests have been conducted. Foam stability experiments have also been conducted. Effects of salt and oil concentration on the foam stability have been investigated. Design of ACTS flow loop modification for foam and aerated mud flow has been completed. A flow loop operation procedure for conducting foam flow experiments under EPET conditions has been prepared Design of the lab-scale flow loop for dynamic foam characterization and cuttings monitoring instrumentation tests has been completed. The construction of the test loop is underway. As part of the technology transport efforts, Advisory Board Meeting with ACTS-JIP industry members has been organized on May 13, 2000.

Performance Enhancement of Abrasive Waterjet Cutting

NARCIS (Netherlands)

2008-01-01

Abrasive Waterjet (AWJ) Machining is a recent non-traditional machining process. This technology is widely used in industry for cutting difficult-to-machine-materials, milling slots, polishing hard materials etc. AWJ machining has many advantages, e.g. it can cut net-shape parts, no heat is

Antimicrobial packaging for fresh-cut fruits

Science.gov (United States)

Fresh-cut fruits are minimally processed produce which are consumed directly at their fresh stage without any further kill step. Microbiological quality and safety are major challenges to fresh-cut fruits. Antimicrobial packaging is one of the innovative food packaging systems that is able to kill o...

Propagation by Cuttings, Layering and Division

OpenAIRE

Relf, Diane; Ball, Elizabeth Carter

2009-01-01

The major methods of asexual propagation are cuttings, layering, division, and budding/grafting. Cuttings involve rooting a severed piece of the parent plant; layering involves rooting a part of the parent and then severing it; and budding and grafting are joining two plant parts from different varieties.

Cutting the L3 torque tube

CERN Multimedia

Laurent Guiraud

2001-01-01

Workers cut the torque tube, with a plasma-cutting device on the L3 experiment, which closed with the LEP accelerator in 2000. L3 was housed in a huge red solenoid, which will be taken over by the ALICE detector when the new LHC is completed.

Slicing Cuts on Food Materials Using Robotic-Controlled Razor Blade

Directory of Open Access Journals (Sweden)

Debao Zhou

2011-01-01

Full Text Available Cutting operations using blades can arise in a number of industries, for example, food processing industry, in which cheese, fruit and vegetable, even meat, are involved. Certain questions will rise during these works, such as “why pressing-and-slicing cuts use less force than pressing-only cuts” and “how is the influence of the blade cutting-edge on force”. To answer these questions, this research developed a mathematical expression of the cutting stress tensor. Based on the analysis of the stress tensor on the contact surface, the influence of the blade edge-shape and slicing angle on the resultant cutting force were formulated and discussed. These formulations were further verified using experimental results by robotic cutting of potatoes. Through studying the change of the cutting force, the optimal slicing angle can be obtained in terms of maximum feeding distance and minimum cutting force. Based on the blade sharpness properties and the specific materials, the required cutting force can be predicted. These formulation and experimental results explained the basic theory of blade cutting fracture and further provided the support to optimize the cutting mechanism design and to develop the force control algorithms for the automation of blade cutting operations.

Stabilization/solidification of synthetic Nigerian drill cuttings | Opete ...

African Journals Online (AJOL)

Stabilization/solidification of synthetic Nigerian drill cuttings. SEO Opete, IA Mangibo, ET Iyagba. Abstract. In the Nigerian oil and gas industry, large quantities of oily and synthetic drill cuttings are produced annually. These drill cuttings are heterogeneous wastes which comprises of hydrocarbons, heavy metals and ...

Short-cut math

CERN Document Server

Kelly, Gerard W

1984-01-01

Clear, concise compendium of about 150 time-saving math short-cuts features faster, easier ways to add, subtract, multiply, and divide. Each problem includes an explanation of the method. No special math ability needed.

Development of YAG laser cutting system for decommissioning nuclear equipments

International Nuclear Information System (INIS)

Kasai, Takeshi; Nitta, Kazuhiko; Hosoda, Hiroshi.

1995-01-01

Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. As a result, the stainless steel plate with a thickness of 22mm could be cut by using an optical fiber which can flexibly propagate laser power, and possibility of application of this laser cutting system to decommissioning nuclear equipments was verified. (author)

Development of YAG laser cutting system for decommissioning nuclear equipments

Energy Technology Data Exchange (ETDEWEB)

Kasai, Takeshi [Fuji Electric Co. Research and Development Ltd., Yokosuka, Kanagawa (Japan); Nitta, Kazuhiko; Hosoda, Hiroshi

1995-07-01

Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. As a result, the stainless steel plate with a thickness of 22mm could be cut by using an optical fiber which can flexibly propagate laser power, and possibility of application of this laser cutting system to decommissioning nuclear equipments was verified. (author).

Biochemical aspects of single-node cuttings of Ricinodendron ...

African Journals Online (AJOL)

NEHEMIE

2013-03-06

Mar 6, 2013 ... changes, basal single-node leafy cuttings were treated with different .... with local material and providing an internal irradiance of 20 to 32%. ..... higher in rooting cutting during the initiation phase). Phenolics ... Chrysanthemum cuttings as affected by nitrogen supply and cold- storage. Ann. Bot. 85:697-701.

21 CFR 882.4190 - Clip forming/cutting instrument.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Clip forming/cutting instrument. 882.4190 Section 882.4190 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES.../cutting instrument. (a) Identification. A clip forming/cutting instrument is a device used by the...

Deferment cutting in Appalachian hardwoods: the what, whys, and hows

Science.gov (United States)

H. Clay Smith; Gary W. Miller

1991-01-01

Deferment cutting is a regeneration practice that resembles a seed-tree or shelterwood cutting. The difference is that residual trees are not cut when the reproduction becomes established. Instead, residual trees are left until new reproduction matures to sawtimber size, and another regeneration cut is the silvicultural objective. Hence, with deferment cutting specific...

A Surgery Issue: Cutting through the Architectural Fabric

Directory of Open Access Journals (Sweden)

Athina Angelopoulou

2017-12-01

Full Text Available This essay examines the material ontologies of surgical trans-modifications. Focusing on incisions and subsequent scars, the essay argues for the queering of architecture and design as an act of cutting through structures and processes. I start by rereading a topological body plan, used by surgeons as a guide for performing incisions. I suggest that this plan constitutes a variation within topological representations. It is thus reconceptualised as an internally contradictory representation, calling for dis/continuous cutting acts upon the represented body; that is an amphi-topological representation. The notion of the cut is further approached from the point of view of queer theory and ‘agential realism’. This perspective offers affirmative ways of discussing about acts of cutting. When performed into self-organizing fabrics, cuts appear to act as ‘agents of dis/continuity’. Then, the discussion passes through the genealogy of the architectural section and the building cuts of Gordon Matta Clark, so as to show that the production of buildings by ‘cutting through them to come to matter’ is deep-rooted in the architectural discipline. Next, the philosophical origins of the idea of cutting through the material fabric of the world are sought. It is argued that the latter, beginning as a gnosiological tool, was transformed into a fabricating tool and then into a tool of smoothing the striated. The essay concludes with the presentation of SCARchiCAD; a computational design tool which takes the skin’s wound healing process as a model, offering an interpretation of what the ‘cutting through a virtual form’ could suggest for the design of architectural bodies and the queering of architecture.

Shroud cutting techniques and collection systems for secondary radioactivity release

International Nuclear Information System (INIS)

Yokoi, H.; Watanabe, A.; Uetake, N.; Shimura, T.; Omote, T.; Adachi, H.; Murakami, S.; Kobayashi, H.; Gotoh, M.

2001-01-01

Replacement of in-core shroud has been conducted as part of the preventive maintenance program in Tsuruga-1. The EDM (electric discharged machining) and plasma cutting methods were applied to in-core shroud cutting and secondary cutting in the DSP (dryer/separator pool), respectively. The cutting systems were improved in order to decrease radioactive secondary products. 1) Fundamental EDM cutting tests: fundamental EDM cutting tests were carried out in order to study secondary products. It could be presumed that volatile Co-carbonyl compound was generated by using a carbon electrode. The Ag/W electrode was effective as EDM electrode for in-core shroud cutting to prevent generation of Co-carbonyl compound and to decrease the total amount of secondary products. 2) In-core shroud cutting in RPV (reactor pressure vessel): EDM cutting system with the Ag/W electrode and collection system could keep a good environment during in-core shroud cutting in Tsuruga-1. Activity concentration was lower value than limitation of mask charge level, 4E-6 Bq/cm 3 , even near the water surface. 3) Secondary plasma cutting in DSP: the secondary cutting work was successful in the point of reduction of working period and radiation exposure. The amount of radiation exposure was reduced to 60% of the planned value, because of adequate decontamination of the working environment and reduction of number of torch maintenance tasks by improvements of the underwater cutting device

Film Editing Handbook; Technique of 16mm Film Cutting.

Science.gov (United States)

Churchill, Hugh B.

Designed to help the film student with the complexities of 16mm film cutting, this handbook catalogs the mechanical procedures of both picture and sound cutting and supplies step-by-step explanations of these procedures. Because the handbook was organized so that it could be used while working at the cutting bench, common cutting problems and…

Test of remote control cutting equipment by Nd:YAG laser

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Akio [Fuji Electric Corp. Research and Development Ltd., Yokosuka, Kanagawa (Japan); Hosoda, Hiroshi

1997-11-01

Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. This report is described the result of experiment by test equipment, about element technology of remote controlled cutting nuclear equipments. (author)

Test of remote control cutting equipment by Nd:YAG laser

International Nuclear Information System (INIS)

Shimizu, Akio; Hosoda, Hiroshi.

1997-01-01

Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. This report is described the result of experiment by test equipment, about element technology of remote controlled cutting nuclear equipments. (author)

arXiv Cuts from residues: the one-loop case

CERN Document Server

Abreu, Samuel; Duhr, Claude; Gardi, Einan

2017-06-14

Using the multivariate residue calculus of Leray, we give a precise definition of the notion of a cut Feynman integral in dimensional regularization, as a residue evaluated on the variety where some of the propagators are put on shell. These are naturally associated to Landau singularities of the first type. Focusing on the one-loop case, we give an explicit parametrization to compute such cut integrals, with which we study some of their properties and list explicit results for maximal and next-to-maximal cuts. By analyzing homology groups, we show that cut integrals associated to Landau singularities of the second type are specific combinations of the usual cut integrals, and we obtain linear relations among different cuts of the same integral. We also show that all one-loop Feynman integrals and their cuts belong to the same class of functions, which can be written as parametric integrals.

PULSED MODE LASER CUTTING OF SHEETS FOR TAILORED BLANKS

DEFF Research Database (Denmark)

Bagger, Claus; Olsen, Flemming Ove

1999-01-01

This paper describes how the laser cutting process can be optimised in such a way that the cut sheets can subsequently be used to laser weld tailored blanks. In a number of systematic laboratory experiments the effect of cutting speed, assist gas pressure, average laser power and pulse energy...... item for parameter optimisation of laser cut sheets used for tailored blanks. It was concluded that high quality cut edges with a squareness as small as 0.015 mm may be obtained. Such edges are well suited for subsequent laser welding....... was analysed. For quality assessment the squareness, roughness and dross attachment of laser cut blanks were measured. In all tests, the medium strength steel GA 260 with a thickness of 1.8 mm was used. In this work it has been successfully demonstrated that the squareness of a cut can be used as a quality...

Multiperipheral ring dynamics and a definition of the complete twisted Reggeon loop

International Nuclear Information System (INIS)

Lucht, P.H.

1977-11-01

The t less than 0 multiperipheral formalism of Ciafaloni, DeTar, Misheloff, Mueller, Muzinich and Yesian is reviewed, extended, and applied to the ordered S-matrix whose ring amplitudes comprise the zeroth level of the topological expansion. Toller M-function notation is used throughout. The bootstrap and cylinder problems are formulated in terms of a well defined helicity pole propagator; a definition of the complete twisted Reggeon loop, which appears in the one-twist term of the cylinder, is given as a helicity pole expansion. Some consideration is given to the following subjects: diagonalization, naturality, threshold behavior, Regge cuts, and complex helicity

Les résonances d'un trou noir de Schwarzschild.

Science.gov (United States)

Bachelot, A.; Motet-Bachelot, A.

1993-09-01

This paper is devoted to the theoretical and computational investigations of the scattering frequencies of scalar, electromagnetic, gravitational waves around a spherical black hole. The authors adopt a time dependent approach: construction of wave operators for the hyperbolic Regge-Wheeler equation; asymptotic completeness; outgoing and incoming spectral representations; meromorphic continuation of the Heisenberg matrix; approximation by dumping and cut-off of the potentials and interpretation of the semi group Z(t) in the framework of the membrane paradigma. They develop a new procedure for the computation of the resonances by the spectral analysis of the transient scattered wave, based on Prony's algorithm.

Material Behavior At The Extreme Cutting Edge In Bandsawing

International Nuclear Information System (INIS)

Sarwar, Mohammed; Haider, Julfikar; Persson, Martin; Hellbergh, Haakan

2011-01-01

In recent years, bandsawing has been widely accepted as a favourite option for metal cutting off operations where the accuracy of cut, good surface finish, low kerf loss, long tool life and high material removal rate are required. Material removal by multipoint cutting tools such as bandsaw is a complex mechanism owing to the geometry of the bandsaw tooth (e.g., limited gullet size, tooth setting etc.) and the layer of material removed or undeformed chip thickness or depth of cut (5 μm-50 μm) being smaller than or equal to the cutting edge radius (5 μm-15 μm). This situation can lead to inefficient material removal in bandsawing. Most of the research work are concentrated on the mechanics of material removal by single point cutting tool such as lathe tool. However, such efforts are very limited in multipoint cutting tools such as in bandsaw. This paper presents the fundamental understanding of the material behaviour at the extreme cutting edge of bandsaw tooth, which would help in designing and manufacturing of blades with higher cutting performance and life. ''High Speed Photography'' has been carried out to analyse the material removal process at the extreme cutting edge of bandsaw tooth. Geometric model of chip formation mechanisms based on the evidences found during ''High Speed Photography'' and ''Quick Stop'' process is presented. Wear modes and mechanism in bimetal and carbide tipped bandsaw teeth are also presented.

29 CFR 1915.55 - Gas welding and cutting.

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Gas welding and cutting. 1915.55 Section 1915.55 Labor... (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Welding, Cutting and Heating § 1915.55 Gas welding and cutting. The provisions of this section shall apply to ship repairing...

29 CFR 1915.56 - Arc welding and cutting.

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Arc welding and cutting. 1915.56 Section 1915.56 Labor... (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Welding, Cutting and Heating § 1915.56 Arc welding and cutting. The provisions of this section shall apply to ship repairing...

29 CFR 1926.351 - Arc welding and cutting.

Science.gov (United States)

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Arc welding and cutting. 1926.351 Section 1926.351 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Welding and Cutting § 1926.351 Arc welding and cutting. (a) Manual electrode holders. (1) Only manual electrode holders which are specifically designed...

29 CFR 1926.350 - Gas welding and cutting.

Science.gov (United States)

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Gas welding and cutting. 1926.350 Section 1926.350 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Welding and Cutting § 1926.350 Gas welding and cutting. (a) Transporting, moving, and storing compressed gas cylinders. (1) Valve protection caps shall...

Laser Cutting Tool Path Optimization

OpenAIRE

Dewil, Reginald; Cattrysse, Dirk; Vansteenwegen, Pieter

2011-01-01

Given a set of irregular parts nested on a metal sheet, minimize the total non- cutting time for the cutter head, cutting all the required elements and returning to the starting location. The problem is modeled as a generalized traveling sales- person problem with special precedence constraints. An initial feasible solution is generated and improved by local moves embedded in a tabu search framework. The proposed algorithm shows promising results in comparison with a commercial...

Innovations: laser-cutting nickel-titanium

Energy Technology Data Exchange (ETDEWEB)

Dickson, T.R.; Moore, B.; Toyama, N. [LPL Systems, Inc., Mountain View, CA (United States)

2002-07-01

Laser-cutting is well established as the preferred method for manufacturing many endovascular medical devices. Sometimes laser processing has been poorly understood by nickel-titanium (NiTi) material suppliers, medical device manufacturers, and device designers, but the field has made important strides in the past several years. A variety of sample, nonspecific applications are presented for cutting tubing and sheet stock. Limiting constraints, key considerations, and areas for future development are identified. (orig.)

Cut without Killing.

Science.gov (United States)

Black, Susan

1991-01-01

The zero-based curriculum model can help school boards and administrators make decisions about what to keep and what to cut. All instructional programs are ranked and judged in categories ranging from required to optional. (MLF)

An Experimental Study of Cutting Performances of Worn Picks

Science.gov (United States)

Dogruoz, Cihan; Bolukbasi, Naci; Rostami, Jamal; Acar, Cemil

2016-01-01

The best means to assess rock cuttability and efficiency of cutting process for using mechanical excavation is specific energy (SE), measured in full-scale rock cutting test. This is especially true for the application of roadheaders, often fitted with drag-type cutting tools. Radial picks or drag bits are changed during the operation as they reach a certain amount of wear and become blunt. In this study, full-scale cutting tests in different sedimentary rock types with bits having various degree of wear were used to evaluate the influence of bit wear on cutting forces and specific energy. The relationship between the amount of wear as represented by the size of the wear flats at the tip of the bit, and cutting forces as well as specific energy was examined. The influence of various rock properties such as mineral content, uniaxial compressive strength, tensile strength, indentation index, shore hardness, Schmidt hammer hardness, and density with required SE of cutting using different levels of tool wear was also studied. The preliminary analysis of the data shows that the mean cutting forces increase 2-3 times and SE by 4-5 times when cutting with 4 mm wear flat as compared to cutting with new or sharp wedge shape bits. The grain size distribution of the muck for cutting different rock types and different level of bit wear was analyzed and discussed. The best fit prediction models for SE based on statistical analysis of laboratory test results are introduced. The model can be used for estimating the performance of mechanical excavators using radial tools, especially roadheaders, continuous miners and longwall drum shearers.

Grading technologies for the manufacture of innovative cutting blades

Science.gov (United States)

Rostek, Tim; Homberg, Werner

2018-05-01

Cutting blades for harvesting applications are used in a variety of agricultural machines. These parts are in contact with highly abrasive lawn clippings and often wear out within hours which results in high expensive re-sharpening maintenance. This paper relates to manufacturing techniques enhancing the durability of cutting blades based on a structural analysis of the prevailing wear mechanisms containing chipping and abrasive wear. Each mechanism results in specific demands on the cutting edge's mechanical characteristics. The design of evaluation methods respectively is one issue of the paper. This is basis for approaches to improve the cutting edge performance on purpose. On option to improve abrasive wear resistance and, thus, service life is the application of locally graded steel materials as semi-finished products for self-sharpening cutting blades. These materials comprise a layered structure consisting of a hard, wear resistant layer and a relatively softer layer which is lesser wear resistant. As the cutting blade is subjected to wear conditions, the less wear resistant layer wears faster than the relatively more wear resistant harder layer revealing a durable cross section of the cutting edge and, thus, cutting performance. Anyways, chipping is another key issue on the cutting edge's lifetime. Here, the cutting edges cross section by means of geometry and grind respectively as well as its mechanical properties matter. FEM analysis reveal innovative options to optimize the cross section of the blade as well as thermomechanical strengthening add further strength to reduce chipping. This paper contains a comprehensive strategy to improve cutting blades with use of innovative manufacturing technologies which apply application-specific graded mechanical characteristics and, thus, significantly improved performance characteristics.

27 CFR 6.92 - Newspaper cuts.

Science.gov (United States)

2010-04-01

... OF THE TREASURY LIQUORS âTIED-HOUSEâ Exceptions § 6.92 Newspaper cuts. Newspaper cuts, mats, or engraved blocks for use in retailers' advertisements may be given or sold by an industry member to a retailer selling the industry member's products. [T.D. ATF-364, 60 FR 20423, Apr. 26, 1995] ...

Laser cutting - trends in the development,

DEFF Research Database (Denmark)

Olsen, Flemming Ove

2002-01-01

Since the laser was invented in 1960, the industrial applications of this tool has grown and grown. And - since the beginning of the 1980'ies, the major industrial application of lasers in production has been laser cutting. In this paper a short review of the development of the laser cutting...

Postharvest: Cut flowers and potted plants

Science.gov (United States)

In the past fifty years, the cut flower market has changed dramatically, from a local market with growers located on city outskirts, to a global one; flowers and cut foliage sourced from throughout the world are sold as bunches or combined into arrangements and bouquets in the major target markets. ...

CAD for cutting head exchange of roadheader

Energy Technology Data Exchange (ETDEWEB)

Tao, Z.; Wu, Z.; Qian, P. [China Coal Research Institute (China). Shanghai Branch

1999-08-01

Improving the cutting method according to the actual operating conditions is an effective way to raise production efficiency. A cutting head designed by means of computer and CAD software is characterized by short design cycle but high design quality. Taking the AM-50 road header as an example, this paper shows that it is feasible to design an interchangeable cutting head for the machine without interfering with the main technical parameters. 2 refs., 5 figs., 1 tab.

Inner tubes cutting method by electrical arc saw

International Nuclear Information System (INIS)

Thome, P.

1990-01-01

The research program deals on the definition of tools used for dismantling steam generator tubes bundle of PWR and on tool used for cutting pipes of great diameter by using the process of cutting by electrical arc saw. The remote tools are used for cutting by the interior pipes of contamined circuits [fr

Study on underwater plasma arc cutting technology

International Nuclear Information System (INIS)

Yada, Toshio; Nakamura, Uhachiro; Tomidokoro, Sakae; Fukuzawa, Mitsuo

1980-01-01

The zirconium alloy tube of the impile creep test facility had been subjected to inner pressure in the Japan Material Testing Reactor (JMTR) environment. In the near future, it will be necessary to dismantle the facility and to take out the tube for such examinations as irradiation effects on material properties. In order to establish the dismantling technology for the radioactive facility, a study on underwater plasma arc cutting has been carried out since 1977. Primarily, optimum underwater cutting sequence and conditions were studied in details for developing the remote control handling and the cutting system. Further, the amounts of particles suspended in water as well as those contained in bubbled gas were quantitatively analyzed for developing a safe removal system for contaminants which were produced by cutting the radioactive material. As a result of this study, it has been concluded that the underwater plasma arc cutting method is generally suitable and effective for dismantling such radioactive material as the impile creep test facility of the JMTR. (author)

Characterisation of aerosols produced by laser cutting

International Nuclear Information System (INIS)

Fauvel, S.; Pilot, G.; Dinechin, G. de; Gosse, X.; Arnaud, P.

2007-01-01

Powerful lasers represent a promising alternative solution to traditional cutting processes used in dismantling nuclear equipments. The use of optical fibers has an unquestionable advantage when dealing with airtight workshops. A study funded by COGEMA Marcoule was undertaken by IRSN/SERAC in collaboration with GIP/GERAILP in order to characterise the aerosols emitted by the cutting of evaporators elements with a 4 kW continuous wave Nd:YAG laser. For this study, laser cutting has been carried out in a tight room of 35 m 3 connected to a particle sampling pipe. Iso-kinetic samplers allowed the measurement of the aerosol concentration. A diffusional and inertial spectrometer (SDI 2001) - an Andersen impinger coupled to a diffusion battery - provided the size distribution. An electrostatic filter used upstream a HEPA filter, itself placed before the extractor fan, collected the majority of the emitted aerosol. Its efficiency was measured and controlled throughout the experiments. The results show the influence of the cutting conditions on the characteristics of the aerosol, and allow a comparison with other cutting tools. (authors)

Elimination of striation in laser cutting of mild steel

International Nuclear Information System (INIS)

Sobih, M; Crouse, P L; Li, L

2007-01-01

High-power laser cutting is extensively used in many industrial applications. An important weakness of this process is the formation of striations (regular lines down the cut surface), which affect the quality of the surfaces produced. The elimination of striation formation is of considerable importance, since it could open up a variety of novel high-precision applications. This study presents the results of oxygen-assisted laser cutting of EN43 mild steel sheets, using a high-power fibre laser. Striation-free laser cuts are demonstrated for cutting 1 and 2 mm thick mild steel sheets. The optimal operating windows are presented and a mathematical method is proposed to estimate the critical speed at which striation-free cut can be obtained

Elimination of striation in laser cutting of mild steel

Energy Technology Data Exchange (ETDEWEB)

Sobih, M; Crouse, P L; Li, L [Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Sackville Street Building, PO Box 88, Manchester M60 1QD (United Kingdom)

2007-11-21

High-power laser cutting is extensively used in many industrial applications. An important weakness of this process is the formation of striations (regular lines down the cut surface), which affect the quality of the surfaces produced. The elimination of striation formation is of considerable importance, since it could open up a variety of novel high-precision applications. This study presents the results of oxygen-assisted laser cutting of EN43 mild steel sheets, using a high-power fibre laser. Striation-free laser cuts are demonstrated for cutting 1 and 2 mm thick mild steel sheets. The optimal operating windows are presented and a mathematical method is proposed to estimate the critical speed at which striation-free cut can be obtaine000.

Combustion-assisted laser cutting of a difficult-to-machine superalloy

International Nuclear Information System (INIS)

Molian, P.A.

1992-01-01

In laser cutting, the largest single application of lasers in manufacturing, the assist gas plays an important role in affecting the cutting performance. The assist gas is usually oxygen or an inert gas. In this paper acetylene and oxygen was employed to create combustion reactions during CO 2 laser cutting that enabled an improvement in the cutting speed, and cut quality of a difficult-to-machine superalloy. A comparison with laser cutting of a plain carbon steel under identical conditions was also made to determine the usefulness of combustion energy. Results indicate that both cutting speed and quality are enhanced by the reduction in the viscosity of slag formed during cutting (which assisted in ejection of the slag through the bottom of the kerf) due to the heat released by the acetylene burning inside the kerf. Correlations of experimental data with a theoretical model provided the influence of combustion power and gas-flow power on the cutting phenomena

Augmented Endoscopic Images Overlaying Shape Changes in Bone Cutting Procedures.

Science.gov (United States)

Nakao, Megumi; Endo, Shota; Nakao, Shinichi; Yoshida, Munehito; Matsuda, Tetsuya

2016-01-01

In microendoscopic discectomy for spinal disorders, bone cutting procedures are performed in tight spaces while observing a small portion of the target structures. Although optical tracking systems are able to measure the tip of the surgical tool during surgery, the poor shape information available during surgery makes accurate cutting difficult, even if preoperative computed tomography and magnetic resonance images are used for reference. Shape estimation and visualization of the target structures are essential for accurate cutting. However, time-varying shape changes during cutting procedures are still challenging issues for intraoperative navigation. This paper introduces a concept of endoscopic image augmentation that overlays shape changes to support bone cutting procedures. This framework handles the history of the location of the measured drill tip as a volume label and visualizes the remains to be cut overlaid on the endoscopic image in real time. A cutting experiment was performed with volunteers, and the feasibility of this concept was examined using a clinical navigation system. The efficacy of the cutting aid was evaluated with respect to the shape similarity, total moved distance of a cutting tool, and required cutting time. The results of the experiments showed that cutting performance was significantly improved by the proposed framework.

High-performance thermal cutting techniques for underwater use

International Nuclear Information System (INIS)

Bach, F.W.

2002-01-01

Over the past few years, the Institute for Materials Research of the University of Hanover developed a new product family (Contact-Arc-Metal-X) of electrothermal techniques for underwater cutting of metal structures. This CAMX technology comprises contact arc metal cutting by means of a sword-shaped electrode, contact arc metal grinding with a rotating electrode, and contact arc metal drilling with an integrated interlocking mechanism. CAMC is characterized by its capability to cut components with complex structures. Undercuts and cavities constitute no obstacles in the process. CAMG is a technique for straight cutting characterized by its high cutting speeds. CAMD is able to produce countersunk boreholes and holes of any geometry. The integrated tensioning mechanism allows parts to be gripped and transported which could not be handled by conventional gripper systems. (orig.) [de

Cutting of Stainless Steel With Fiber and Disk Laser

DEFF Research Database (Denmark)

Wandera, Catherine; Salminen, Antti; Olsen, Flemming Ove

2006-01-01

Laser cutting is a major application of laser materials processing. The cutting is usually performed with CO2-laser due to its good beam quality and its relatively low costs of ownership. Ever since entering the market the high power solid state lasers have been expected to achieve a dominating...... of both of the new lasers against traditional CO2-laser. The results showed that the new lasers offer a great potential in improving the productivity of cutting phase with an acceptable edge quality. This is emphasized in thin sheets of 1.3 and 2.3 mm thickness. In that case the width of the cut kerf...... of each thickness. The results were very promising and it can be stated that these new laser types have a great potential in cutting and will probably gain a considerable market share not only in 3D cutting applications but also in ordinary flat sheet cutting....

A review on ductile mode cutting of brittle materials

Science.gov (United States)

Antwi, Elijah Kwabena; Liu, Kui; Wang, Hao

2018-06-01

Brittle materials have been widely employed for industrial applications due to their excellent mechanical, optical, physical and chemical properties. But obtaining smooth and damage-free surface on brittle materials by traditional machining methods like grinding, lapping and polishing is very costly and extremely time consuming. Ductile mode cutting is a very promising way to achieve high quality and crack-free surfaces of brittle materials. Thus the study of ductile mode cutting of brittle materials has been attracting more and more efforts. This paper provides an overview of ductile mode cutting of brittle materials including ductile nature and plasticity of brittle materials, cutting mechanism, cutting characteristics, molecular dynamic simulation, critical undeformed chip thickness, brittle-ductile transition, subsurface damage, as well as a detailed discussion of ductile mode cutting enhancement. It is believed that ductile mode cutting of brittle materials could be achieved when both crack-free and no subsurface damage are obtained simultaneously.

Demonstrating diamond wire cutting of the TFTR

International Nuclear Information System (INIS)

Rule, K.; Perry, E.; Larson, S.; Viola, M.

2000-01-01

The Tokamak Fusion Test Reactor (TFTR) ceased operation in April 1997 and decommissioning commenced in October 1999. The deuterium-tritium fusion experiments resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 50 mRem/hr. These radiological hazards along with the size of the Tokamak (100 cubic meters) present a unique and challenging task for dismantling. Plasma arc cutting is the current baseline technology for the dismantlement of fission reactors. This technology is typically used because of its faster cutting times. Alternatively, an innovative approach for dismantlement of the TFTR is the use of diamond wire cutting technology. Recent improvements in diamond wire technology have allowed the cutting of carbon steel components such as pipe, plate, and tube bundles in heat exchangers. Some expected benefits of this technology include: significantly reduction in airborne contaminates, reduced personnel exposure, a reduced risk of spread of tritium contamination, and reduced overall costs as compared to using plasma arc cutting. This paper will provide detailed results of the diamond wire cutting demonstration that was completed in September of 1999, on a mock-up of this complex reactor. The results will identify cost, safety, industrial and engineering parameters, and the related performance of each situation

Demonstrating diamond wire cutting of the TFTR

Energy Technology Data Exchange (ETDEWEB)

Rule, K.; Perry, E.; Larson, S.; Viola, M. [and others

2000-02-24

The Tokamak Fusion Test Reactor (TFTR) ceased operation in April 1997 and decommissioning commenced in October 1999. The deuterium-tritium fusion experiments resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 50 mRem/hr. These radiological hazards along with the size of the Tokamak (100 cubic meters) present a unique and challenging task for dismantling. Plasma arc cutting is the current baseline technology for the dismantlement of fission reactors. This technology is typically used because of its faster cutting times. Alternatively, an innovative approach for dismantlement of the TFTR is the use of diamond wire cutting technology. Recent improvements in diamond wire technology have allowed the cutting of carbon steel components such as pipe, plate, and tube bundles in heat exchangers. Some expected benefits of this technology include: significantly reduction in airborne contaminates, reduced personnel exposure, a reduced risk of spread of tritium contamination, and reduced overall costs as compared to using plasma arc cutting. This paper will provide detailed results of the diamond wire cutting demonstration that was completed in September of 1999, on a mock-up of this complex reactor. The results will identify cost, safety, industrial and engineering parameters, and the related performance of each situation.

Optimization and Analysis of Cutting Tool Geometrical Parameters ...

African Journals Online (AJOL)

ADOWIE PERE

Bassett et al.,(2012);. Kountanya et al., (2016) studied the effect of tool edge geometry and cutting conditions on the chip morphology in orthogonal hard turning of 100Cr6 steel. Their study shows that the edge radius does not influence the geometrical parameters of the chip. Moreover cutting forces decreases as the cutting.

Orthogonal cutting of laser beam melted parts

Science.gov (United States)

Götze, Elisa; Zanger, Frederik; Schulze, Volker

2018-05-01

The finishing process of parts manufactured by laser beam melting is of high concern due to the lack of surface accuracy. Therefore, the focus of this work lies on the influence of the build-up direction of the parts and their effect on the finishing process. The orthogonal cutting reveals findings in the fields of chip formation, involved forces and temperatures appearing during machining. In the investigations, the cutting depth was varied between 0.05 and 0.15 mm representing a finishing process and the cutting velocity ranges from 30 to 200 m/min depending on the material. The experiments contain the materials stainless steel (AISI 316L), titanium (Ti6Al4V) and nickel-base alloy (IN718). The two materials named latter are of high interest in the aerospace sector and at the same time titanium is used in the medical field due to its biocompatibility. For the materials IN718 and Ti6Al4V a negative rake angle of -7.5° and for stainless steel a rake angle of 12.5° are chosen for the cutting experiments. The results provide the base for processing strategies. Therefore, the specimens were solely laser beam melted without post-processing like heat treatment. The evaluation of the experiments shows that an increase in cutting speed has different effects depending on the material. For stainless steel the measured forces regarding the machining direction to the layers approach the same values. In contrast, the influence of the layers regarding the forces appearing during orthogonal cutting of the materials IN718 and Ti6Al4V differ for lower cutting speeds.

Vortex cutting in superconductors

Science.gov (United States)

Vlasko-Vlasov, Vitalii K.; Koshelev, Alexei E.; Glatz, Andreas; Welp, Ulrich; Kwok, Wai-K.

2015-03-01

Unlike illusive magnetic field lines in vacuum, magnetic vortices in superconductors are real physical strings, which interact with the sample surface, crystal structure defects, and with each other. We address the complex and poorly understood process of vortex cutting via a comprehensive set of magneto-optic experiments which allow us to visualize vortex patterns at magnetization of a nearly twin-free YBCO crystal by crossing magnetic fields of different orientations. We observe a pronounced anisotropy in the flux dynamics under crossing fields and the filamentation of induced supercurrents associated with the staircase vortex structure expected in layered cuprates, flux cutting effects, and angular vortex instabilities predicted for anisotropic superconductors. At some field angles, we find formation of the vortex domains following a type-I phase transition in the vortex state accompanied by an abrupt change in the vortex orientation. To clarify the vortex cutting scenario we performed time-dependent Ginzburg-Landau simulations, which confirmed formation of sharp vortex fronts observed in the experiment and revealed a left-handed helical instability responsible for the rotation of vortices. This work was supported by the U.S. Department of Energy, Office of Science, Materials Sciences and Engineering Division.

Loop equations for multi-cut matrix models

International Nuclear Information System (INIS)

Akemann, G.

1995-03-01

The loop equation for the complex one-matrix model with a multi-cut structure is derived and solved in the planar limit. An iterative scheme for higher genus contributions to the free energy and the multi-loop correlators is presented for the two-cut model, where explicit results are given up to and including genus two. The double-scaling limit is analyzed and the relation to the one-cut solution of the hermitian and complex one-matrix model is discussed. (orig.)

Parametric studies of cutting zircaloy-2 sheets with a laser beam

International Nuclear Information System (INIS)

Ghosh, S.; Badgujar, B.P.; Goswami, G.L.

1996-01-01

The highly reactive and pyrophoric nature of zirconium alloys limits the use of conventional thermal sources (e.g., plasma arc cutting, oxygen flame cutting, etc.) for the cutting and drilling of these alloys. In this context, a highly coherent laser beam provides a good alternative for the cutting and drilling. In the present paper, laser beam cutting of zircaloy-2 sheets of 1.1 mm and 0.74 mm thickness is performed using a 300 W average power pulsed Nd:YAG laser. Pulse energy, pulse repetition rate, nozzle gap, gas pressure and cutting speed were varied to give different laser cutting conditions. Metallographic study of the cut surfaces showed the presence of transformed beta phase in the heat affected zone (HAZ) near the cut surface. The microhardness value across the cut surface was also measured. It showed a gradual increase in microhardness from the base metal (160 VHN) towards the HAZ having a maximum value of 365 VHN. The results of parametric studies of the cutting indicated that, with proper selection of process parameters, very narrow cuts can be easily made in zircaloy-2 using a pulsed Nd:YAG laser with a saving in material and at a much faster rate than alternative processes such as plasma arc cutting and oxygen flame cutting

A German research project about applicable graphite cutting techniques

International Nuclear Information System (INIS)

Holland, D.; Quade, U.; Bach, F.W.; Wilk, P.

2001-01-01

In Germany, too, quite large quantities of irradiated nuclear graphite, used in research and prototype reactors, are waiting for an environmental way of disposal. While incineration of nuclear graphite does not seem to be a publicly acceptable way, cutting and packaging into ductile cast iron containers could be a suitable way of disposal in Germany. Nevertheless, the cutting of graphite is also a very difficult technique by which a large amount of secondary waste or dust might occur. An applicable graphite cutting technique is needed. Therefore, a group of 13 German partners, consisting of one university, six research reactor operators, one technical inspection authority, three engineering companies, one industrial cutting specialist and one commercial dismantling company, decided in 1999 to start a research project to develop an applicable technique for cutting irradiated nuclear graphite. Aim of the project is to find the most suitable cutting techniques for the existing shapes of graphite blocks with a minimum of waste production rate. At the same time it will be learned how to sample the dust and collect it in a filter system. The following techniques will be tested and evaluated: thermal cutting, water jet cutting, mechanical cutting with a saw, plasma arc cutting, drilling. The subsequent evaluation will concentrate on dust production, possible irradiation of staff, time and practicability under different constraints. This research project is funded by the German Minister of Education and Research under the number 02 S 7849 for a period of two years. A brief overview about the work to be carried out in the project will be given. (author)

Vapor-melt Ratio in Laser Fine Cutting of Slot Arrays

International Nuclear Information System (INIS)

Wang Xuyue; Meng Qingxuan; Kang Renke; Xu Wenji; Guo Dongming; Wang Lianji

2011-01-01

In order to improve cut quality for slot arrays, a new method of laser fine cutting under the consideration of the ratio of vapor to melt is presented. Laser cutting of 6063 aluminum alloy sheet, 0.5 mm in thickness, was carried out on a JK701H Nd:YAG pulse laser cutting system. The effects of vapor-melt ratio on kerf width, surface roughness and recast layer were studied which relate cutting qualities. Observation on the cut samples with different vapor-melt ratios (0.687, 1.574, 3.601 varied with laser power increasing, and 1.535, 3.601, 7.661 with decreasing of beam cutting speed) shows that high vapor-melt ratio improves laser cut quality clearly. Kerf width 0.2 mm of smooth area on kerf top area and thickness 2.03 μm of recast layer are obtained. No dross was found on the kerf bottom and the percentage of the smooth area is up to 40% out of whole kerf side. The research on vapor-melt ratio provides a deeper understanding of laser cutting and improves laser cut quality effectively.

Comparison of CO2 Laser Cutting with Different Laser Sources

DEFF Research Database (Denmark)

Ketting, Hans-Ole; Olsen, Flemmming Ove

1996-01-01

This paper contains CO2 laser cutting results in mild and stainless steel with different laser sources. The main factors which affect the cutting speed and quality are the power, the cutting gas and focal point conditions. Keeping the power and cutting gas constant, the focal point conditions have...... size,for the maximum cutting speed. One of the 7 laser sources with different focal length and thus different minimum spot size, was then used to investigate more in details the importance of the focal spot size cutting stainless steel with high pressure nitrogen. It looks as if there is a strong...... connection between the smallest avail-able spot size and cutting speed in mild steel, whereas the conditions in stainless steel, depends strongly on the flow conditions in the cut kerf, and not only on the focal spot size....

Development of cutting machine for disposal of highly activated equipments

International Nuclear Information System (INIS)

Iimura, Katumichi; Kitajima, Toshio; Hosokawa, Jinsaku; Abe, Shinichi; Takahashi, Kiyoshi; Ogawa, Mituhiro; Iwai, Takashi

1994-01-01

JMTR (Japan Materials Testing Reactor) Project has developed a cutting machine which can cut a highly activated in-pile tube under water and its performance and safety have been confirmed. This machine is for the purpose of cutting a multiplet structure pipe and made possible to cut it under water by adopting under-water discharge method. Furthermore, contamination of canal water and atmosphere is prevented by combining a filter with this machine. This report describes the outline and performance of the developed cutting machine and also results of cutting highly activated in-pile tubes. (author)

Experimental study for development of thermic lance cutting method

International Nuclear Information System (INIS)

Machida, N.; Katano, Y.; Kamiya, Y.

1988-01-01

A series of experiments on a thermic lance cutting method were carried out to obtain useful data for the practical application of this method to the dismantling of reinforced concrete. As a first step, a performance experiment was executed to study basic cutting performance relating to oxygen consumption, extent of bar loss and cutting speed, as well as by-products generated during cutting work such as powdered dust, gas, fumes and slag. An automated and remote-controlled cutting machine was then developed utilizing automated bar supply and ignition. This paper describes the result of these experiments. (author)

Cutting Watermelon: Lessons in Instructional Coaching

Science.gov (United States)

Sandstead, Martha

2016-01-01

Literacy coordinator Martha Sandstead finds inspiration for her coaching work in a quote from civil rights organizer Lawrence Guyot: "Let's say you're riding past a picnic, and people are cuttin' watermelons. You don't immediately go and say, "stop the watermelon cutting" and let's talk. … You cut some watermelons, or you help…

Drilling subsurface wellbores with cutting structures

Science.gov (United States)

Mansure, Arthur James; Guimerans, Rosalvina Ramona

2010-11-30

A system for forming a wellbore includes a drill tubular. A drill bit is coupled to the drill tubular. One or more cutting structures are coupled to the drill tubular above the drill bit. The cutting structures remove at least a portion of formation that extends into the wellbore formed by the drill bit.

Rooting Cuttings of Cottonwood, WilIow, and Sycamore

Science.gov (United States)