Independent Degree Research Articles

Finite deformation model of simple shear of fault with microrotations: apparent strain localisation and en-echelon fracture pattern

Strain localisation is a widespread phenomenon often observed in shear and compressive loading of geomaterials, for example, the fault gouge. It is believed that the main mechanisms of strain localisation are strain softening and mismatch between dilatancy and pressure sensitivity. Observations show that gouge deformation is accompanied by considerable rotations of grains. In our previous work as a model for gouge material, we proposed a continuum description for an assembly of particles of equal radius in which the particle rotation is treated as an independent degree of freedom. We showed that there exist critical values of the model parameters for which the displacement gradient exhibits a pronounced localisation at the mid-surface layers of the fault, even in the absence of inelasticity. Here, we generalise the model to the case of finite deformations characteristic for the gouge deformation. We derive objective constitutive relationships relating the Jaumann rates of stress and moment stress to the relative strain and curvature rates, respectively. The model suggests that the pattern of localisation remains the same as in the linear case. However, the presence of the Jaumann terms leads to the emergence of non-zero normal stresses acting along and perpendicular to the shear layer (with zero hydrostatic pressure), and localised along the mid-line of the gouge; these stress components are absent in the linear model of simple shear. These additional normal stresses, albeit small, cause a change in the direction in which the maximal normal stresses act and in which en-echelon fracturing is formed.

Teaching of undergraduate psychology in Russia

Psychology instruction in Russia began at Moscow University in the mid‐18th century. Independent degree programs in psychology have only existed for about the last half‐century. More than 100 new psychology departments and faculties in universities that run psychology degree undergraduate programs have been established in the last decade. Many students wish to become psychologists or at least study psychology. Currently, both 4‐year and 5‐year undergraduate degree programs are offered in Russian universities. These programs are regulated by the Ministry of Education, but several local and regional differences exist among the programs. New guidelines are established every 5 years. In all institutions of higher education, two types of undergraduate programs in psychology are currently offered: Specialist degree (5 years) and Bachelor's degree (4 years). Specialist programs are designed to allow students to pursue both educational and professional goals, while Bachelor programs aim only at educational goals and do not seek to prepare professional psychologists. Psychology degree programs include many required psychology courses covering basic, applied, and methodological topics. The undergraduate programs in Russia are run according to national standards endorsed by a Ministry of Education Agency. These contain required topics for every degree. Each university then develops its curriculum, taking into account these requirements. Teaching methodology varies widely from course to course and among instructors. Small group and individual discussion and consultation, lecture, applied activities, reading, writing, and written and oral exams are utilized, as are other types of instruction. Students also complete cumulative final exams over their coursework at the end of each semester. Russian education is currently undergoing many changes, and these changes influence psychology education as well as other programs. Overall, though, programs are comparable to their European and US counterparts, with additional unique features. Psychology continues to develop as an important discipline in Russian education.

On the Possibility of Elastic Strain Localisation in a Fault

The phenomenon of strain localisation is often observed in shear deformation of particulate materials, e.g., fault gouge. This phenomenon is usually attributed to special types of plastic behaviour of the material (e.g., strain softening or mismatch between dilatancy and pressure sensitivity or both). Observations of strain localisation in situ or in experiments are usually based on displacement measurements and subsequent computation of the displacement gradient. While in conventional continua the symmetric part of the displacement gradient is equal to the strain, it is no longer the case in the more realistic descriptions within the framework of generalised continua. In such models the rotations of the gouge particles are considered as independent degrees of freedom the values of which usually differ from the rotation of an infinitesimal volume element of the continuum, the latter being described for infinitesimal deformations by the non-symmetric part of the displacement gradient. As a model for gouge material we propose a continuum description for an assembly of spherical particles of equal radius in which the particle rotation is treated as an independent degree of freedom. Based on this model we consider simple shear deformations of the fault gouge. We show that there exist values of the model parameters for which the displacement gradient exhibits a pronounced localisation at the mid-layers of the fault, even in the absence of inelasticity. Inelastic effects are neglected in order to highlight the role of the independent rotations and the associated additional parameters. The localisation-like behaviour occurs if (a) the particle rotations on the boundary of the shear layer are constrained (this type of boundary condition does not exist in a standard continuum) and (b) the contact moment-or bending stiffness is much smaller than the product of the effective shear modulus of the granulate and the square of the width of the gouge layer. It should be noted however that the virtual work functional is positive definite over the range of physically meaningful parameters (here: contact stiffnesses, solid volume fraction and coordination number) so that strictly speaking we are not dealing with a material instability.

A nonperturbative calculation of the electron's magnetic moment

In principle, the complete spectrum and bound-state wave functions of a quantum field theory can be determined by finding the eigenvalues and eigensolutions of its light-cone Hamiltonian. One of the challenges in obtaining nonperturbative solutions for gauge theories such as QCD using light-cone Hamiltonian methods is to renormalize the theory while preserving Lorentz symmetries and gauge invariance. For example, the truncation of the light-cone Fock space leads to uncompensated ultraviolet divergences. We present two methods for consistently regularizing light-cone-quantized gauge theories in Feynman and light-cone gauges: (1) the introduction of a spectrum of Pauli–Villars fields which produces a finite theory while preserving Lorentz invariance; (2) the augmentation of the gauge-theory Lagrangian with higher derivatives. In the latter case, which is applicable to light-cone gauge ( A + = 0 ), the A − component of the gauge field is maintained as an independent degree of freedom rather than a constraint. Finite-mass Pauli–Villars regulators can also be used to compensate for neglected higher Fock states. As a test case, we apply these regularization procedures to an approximate nonperturbative computation of the anomalous magnetic moment of the electron in QED as a first attempt to meet Feynman's famous challenge.

Hydrodynamics of isotropic ferrogels.

We derive the complete set of macroscopic dynamic equations for ferrogels under an external magnetic field, including the magnetization as an independent dynamic degree of freedom. The magnetoelasticity comes in the form of magnetostriction and through the magnetic part of the Maxwell stress. Various dynamic couplings of the elastic degree of freedom with the magnetization and the magnetic field are found. We discuss static elongation, shear deformations, and the modified sound spectrum in the presence of an external magnetic field.

Macroscopic dynamics of ferronematics

We derive the complete set of macroscopic dynamic equations for ferrofluids in the nematic liquid crystal phase under an external magnetic field. We include the magnetization as an independent dynamic degree of freedom. Special emphasis is laid on possible static and dynamic cross couplings between magnetization, director reorientations and flow. As examples we discuss the field dependence of the sound spectrum and the rheology of shear flow.

Analysis of linear systems with fuzzy parametric uncertainty

In this paper the problem of determining the stability margin of a linear system with fuzzy parametric uncertainty is addressed. This kind of systems arise when the exact value of a process parameter is not available, but an estimation of the value is given by an expert (“more or less 5”). As the α-cut representation of a fuzzy number is a functional interval, interval analysis shows to be a suitable tool to deal with fuzziness. Based on the Argoun's stability test for interval systems, a new methodology, with a natural graphical interpretation, is presented. An independent confidence degree for every coefficient is considered, allowing a clear understanding on how each coefficient affects stability. An analysis on how precise one should be on some coefficients to allow more uncertainty on others can be carried out. A comparison with Tsypkin–Polyak plot is also presented.

The Spirit of Capitalism? Religious Doctrine, Values, and Economic Attitude Constructs

This article examines the relationship between conservative Protestant doctrine and economic policy attitudes. Building upon Weber's (1930) classic (and controversial) thesis that Calvinist thought inspired the “capitalist spirit,” we posit that the individualistic theology of fundamentalists, evangelicals, and charismatics often engenders political preferences for individualistic economic policies. We test this hypothesis by (1) performing a series of cross-sectional ordered probit analyses to understand the independent degree of association between doctrinal belief and economic attitudes toward taxing, spending, and the role of government, (2) creating and testing a structural equation model to assess various hypothesized paths of influence, and finally, (3) using 1994–96 NES panel data to assess the degree to which changes in an individual's doctrinal beliefs produce changes in his or her economic attitudes. Results lend substantial support to the efficacy of Weber's thesis, and point to religious belief as one exogenous agent of core political values.

"Brownian strings": Segmenting images with stochastically deformable contours

This paper describes an image segmentation technique in which an arbitrarily shaped contour was deformed stochastically until it fitted around an object of interest. The evolution of the contour was controlled by a simulated annealing process which caused the contour to settle into the global minimum of an image-derived function. The nonparametric energy function was derived from the statistical properties of previously segmented images, thereby incorporating prior experience. Since the method was based on a state space search for the contour with the best global properties, it was stable in the presence of image errors which confound segmentation techniques based on local criteria, such as connectivity. Unlike snakes and other active contour approaches, the new method could handle arbitrarily irregular contours in which each interpixel crack represented an independent degree of freedom. Furthermore, since the contour evolved toward the global minimum of the energy, the method was more suitable for fully automatic applications than the snake algorithm, which frequently has to be reinitialized when the contour becomes trapped in local energy minima. High computational complexity was avoided by efficiently introducing a random local perturbation in a time independent of contour length, providing control over the size of the perturbation, and assuring that resulting shape changes were unbiased. The method was illustrated by using it to find the brain surface in magnetic resonance head images and to track blood vessels in angiograms.

Space-variant simultaneous detection of several objects by the use of multiple anamorphic fractional-Fourier-transform filters

A fractional correlator that is based on the anamorphic fractional Fourier transform is defined. This new, to our knowledge, correlator has been extended to work with multiple filters. The novelty introduced by the suggested system is the possibility of the simultaneous detection of several objects in different parts of the input scene (when anamorphic optics are dealt with), thereby permitting an independent degree of space invariance in two perpendicular directions. Computer experiments as well as experimental optical implementation are presented.

Propagation of sound with massivelike modes in relativistic Bose condensates.

We study the nature and spectrum of the fundamental excitations in a relativistic Bose condensate, represented by a classical complex scalar field in a relativistic U(1)-symmetric nonlinear model. ``Optical,'' or massivelike, modes, which are a pure relativistic field effect, are observed (in addition to the ordinary first-sound phonon modes). The spectrum of the phonon modes is naturally limited by the model to wavelengths larger than the Compton wavelength associated with the fluid, and they may develop runaway plane-wave solutions. The massivelike modes involve pair creation, with an unlimited spectrum, and plane-wave solutions are always bounded. The large-scale effects of the massivelike modes are mainly manifested in expansion of the medium and increasing the energy content per particle together with a fluctuating pressure, generally composed with movement relative to the homogeneous background medium. The appearance of the massivelike modes is directly related to the field's amplitude behing an independent degree of freedom, corresponding to nonlocal equations of state in the hydrodynamic picture.

Errata to: ‘‘Analysis and applications of holomorphic functions in higher dimensions”

?2 of [2], the Greek letter v' should be replaced by the italic v. It appears in the second line of the section and lines 5 and 6 of page 154. ?8, the very last expression (m + n 3)!/m!(n 2)! in the proof of Corollary 8.2 should be augmented to (m + n 3)!(2m + n 2)/m!(n 2)! = N(m, n). Also, the last paragraph of ?8 was inadvertently omitted. It should read: In [9] it was shown that N(m, n) is more generally the number of independent mth degree homogeneous polynomial solutions of a certain basic type of second order partial differential equations in Rn including the Laplace and the wave equations. The said reference [9] above is restated here below as reference [1].

Quantum mechanics of charged-particle beam transport through magnetic lenses.

The quantum theory of charged-particle beam transport through a magnetic lens system with a straight optic axis, at the level of single-particle dynamics and disregarding spin (or, when nonzero, assuming it to be an independent spectator degree of freedom), is presented, based on the Schr\"odinger and Klein-Gordon equations in a form suitable for analyzing the paraxial and aberration aspects in a systematic way using a Lie algebraic approach. In the classical limit, the well known Lie algebraic treatment of the corresponding classical theory is obtained. As examples, quadrupole and axially symmetric magnetic lenses are considered. An extension of the theory to the cases of electrostatic and other electromagnetic lens systems is outlined. This work is complementary to an already known similar approach to the spinor electron optics based on the Dirac equation and provides the corresponding framework when the optics of charged particles, with or without spin, is described with scalar wave functions in the nonrelativistic and relativistic situations.

Mechanics and energetics of the Bain transformation

Abstract The general mechanics and energetics of the Bain transformation are presented. The Bain transformation takes a crystal from its b.c.c. configuration into its f.c.c. structure, or vice versa, by means of homogeneous axial deformations. The crystal remains b.c.t. on the transformation path, and different types of Bain transformation may be distinguished by the response of the transverse lattice parameters to incremental changes in the longitudinal lattice parameter. A rational means of comparing the various types is made possible by defining the longitudinal stretch as the independent variable or degree of transformation. It is shown that, among possible Bain transformations, the one that occurs under a uniaxial-loading environment has the lowest binding energy at any given stage of transformation. In addition, the lowest possible barrier energy for any Bain transformation occurs when the crystal passes through a special unstresssd tetragonal state that resides at a local energy maximum on the unia...

Extremal problems and generalized degrees

For a positive integer n and a graphical property P, extn(P) will denote the minimal number of edges in a graph G of order n that satisfies property P, and Ext>n(P) will denote the class of graphs with n vertices and extn(P) edges that have property P. The extremal numbers extn(P) for properties P that have been commonly used as sufficient conditions for Hamiltonian paths and cycles in graphs will be investigated. In particular, results on the extremal numbers for the generalized degree and generalized independent degree properties will be given, where for a fixed positive integer t, the generalized degree δt(G) (generalized independent degree δit(G)) is the minimum number of vertices in the union of the neighborhoods of a set of t (independent) vertices of the graph G.

The effect of surface roughness and crystallinity on the light scattering of polyethylene tubular blown films

AbstractAn experimental study of the effect of surface roughness and crystallinity on the light scattering of polyethylene tubular blown films is reported. Several films were prepared by varying the raw polyethylenes and the extrusion temperature. Other processing variables were maintained constant. We have made a statistical analysis of data and we have obtained multiple regressions between light scattering for a given wavelength of incident light and a given film thickness (30 μm, 50 μm, and 70 μm) and the independent variables average surface roughness and degree of crystallinity. It was demonstrated that, for the polymeric films studied, the surface texture evaluates better than crystallinity the variation of light scattering, but crystallinity has also some importance.

Photonics enrichment of the EE curriculum

The authors describe how the conventional undergraduate electrical engineering curriculum can accommodate, and be enriched by, an infusion of optical-related subjects. Some combination of the following is recommended: incorporating material on photonics into existing electrical engineering core courses; offering photonic electives for undergraduate electrical engineering students; offering photonics options (well-defined curricula for students wishing to specialize in photonics) within existing electrical engineering or physics departments; and developing independent degree programs in photonics. >

Reconsidering Bibliographic Instruction for Adult Reentry Students: Emphasizing the Practical

A survey conducted by the College Board and reported in the Chronicle of Higher Education revealed that six million adults study for college credit each year, and that 45 percent of all undergraduate and graduate students are over twenty‐five years of age. The survey also predicted the figure could rise to 50 percent by the year 2000. Recent adult education literature offers many papers advising colleges to gear up and embrace the reentry student. Academe's metamorphosis, demonstrated by independent degree programs, more weekend and evening classes, and other enticements, confirms this reorientation. A community adult education course entitled “Academia Revisited,” which is intended specifically as a preenrollment introduction for prospective reentrants, is a signal that colleges are actively courting the adult student. Increasing enrollments of adults attest a positive response to these changes.

Independent Study Degree Programs At Syracuse University

What do a grandmother from Connecticut, a lobster restaurant owner from Maine, and an assistant foodservice director of a 500-bed hospital from New York City have in common ? They are all pursuing their Bachelor of Science Degrees in Food systems Management at Syracuse University taking advantage of an innova tive approach to education called the Independent Study Degree Program (ISDP). The ISDP format combines two elements: an intensive one-week, on-campus residence, and a variety of individual learning activities that the working professional completes at home. This approach allows the working professionals to continue their full-time management positions, while still pursuing the B.S. degrees. The only alternative for completing the bachelor's degree would be taking one or two night courses each semester for the next ten years. One of the keygoals of the program is for the participants to gain a clearerinsight into the elements necessary for success in hospitality management. This is accomplished through course work with faculty in the Food Management Program as well as seniorfacultyfrom the distinguished School of Management. Throughout the semester the students andfaculty are in contact via telephone, letters, electronic mail, and even videos. The primary benefit of this innovative approach to education is that the working manager can immediately apply the new knowledge to the job. Since many of the students have an associate's degree it is realistic for them as working professionals to complete their bachelor's degree in two to three years. Syracuse University has had an active Independent Study Degree since 1966 and all ISDP programs are fully accredited by Middle States and the prestigious Association ofAmerican Universities. At the present time, Food Systems Manage ment ISDP students join seven other studies of program including those working professionals pursuing M.B.A. degrees. The total number of students enrolled in ISDP is over 2, 000 with students coming from most states in the country and from over 20 foreign countries. For more information about this innovative approach to education contact: Robert Colley, Director, ISDP-Syracuse University, 301 Reid Hall, 610 E. Fayette Avenue, Syracuse, NY 13244-6020; phone: (315) 443-3269; FAX: (315) 443-1928.

Phase dynamics with a material derivative due to a flow field.

We show that a flow field, which can be either externally imposed or caused by the geometrical configuration, gives rise to a convective term or a material derivative in the resulting phase equation. The stationary solutions of this equation are in agreement with recent experimental results on convection with a through flux and on the flow between two rotating concentric cones (a modified Taylor configuration). We also discuss the fact that there is no additional independent dynamic degree of freedom associated with these flow fields.