10,724 research outputs found
Classical Electron Model with Negative Energy Density in Einstein-Cartan Theory of Gravitation
Experimental result regarding the maximum limit of the radius of the electron
\sim 10^{-16} cm and a few of the theoretical works suggest that the
gravitational mass which is a priori a positive quantity in Newtonian mechanics
may become negative in general theory of relativity. It is argued that such a
negative gravitational mass and hence negative energy density also can be
obtained with a better physical interpretation in the framework of
Einstein-Cartan theory.Comment: 12 Latex pages, added refs and conclusion
Solar variability in the past and palaeoclimate data pertaining to the southwest monsoon
A significant part of the earth's climate variability is caused by changes in the solar emission. Instrumental observation of the sun gives us some idea about decadal variability in the solar radiation. On longer timescales, we look to palaeoclimate proxies to learn about solar variability. In this review we discuss various palaeo-records and what we have learnt from them. In addition, we outline important questions that need to be addressed
Evaluating the Chinese Revised Controlling Behaviors Scale (C-CBS-R)
The present study evaluated the utility of the Chinese version of the Revised Controlling Behaviors Scale (C-CBS-R) as a measure of controlling behaviors in violent Chinese intimate relationships. Using a mixed-methods approach, in-depth, individual interviews were conducted with 200 Chinese women survivors to elicit qualitative data about their personal experiences of control in intimate relationships. The use of controlling behaviors was also assessed using the C-CBS-R. Interview accounts suggested that the experiences of 91 of the women were consistent with the description of coercive control according to Dutton and Goodman’s (2005) conceptualization of coercion. Using the split-half validation procedure, a receiver operating characteristics (ROC) curve analysis was conducted with the first half of the sample. The area under the curve (AUC) for using the C-CBS-R to identify high control was .99, and the cutoff score of 1.145 maximized both sensitivity and specificity. Applying the cutoff score to the second half gave a sensitivity of 96% and a specificity of 95%. Overall, the C-CBS-R has demonstrated utility as a measure of controlling behaviors with a cutoff score for distinguishing high from low levels of control in violent Chinese intimate relationships
Implementing the Lean Sigma Framework in an Indian SME: a case study
Lean and Six Sigma are two widely acknowledged business process improvement strategies available to organisations today for achieving dramatic results in cost, quality and time by focusing on process performance. Lately, Lean and Six Sigma practitioners are integrating the two strategies into a more powerful and effective hybrid, addressing many of the weaknesses and retaining most of the strengths of each strategy. Lean Sigma combines the variability reduction tools and techniques from Six Sigma with the waste and non-value added elimination tools and techniques from Lean Manufacturing, to generate savings to the bottom-line of an organisation. This paper proposes a Lean Sigma framework to reduce the defect occurring in the final product (automobile accessories) manufactured by a die-casting process. The proposed framework integrates Lean tools (current state map, 5S System, and Total Productive Maintenance (TPM)) within Six Sigma DMAIC methodology to enhance the bottom-line results and win customer loyalty. Implementation of the proposed framework shows dramatic improvement in the key metrics (defect per unit (DPU), process capability index, mean and standard deviation of casting density, yield, and overall equipment effectiveness (OEE)) and a substantial financial savings is generated by the organisation
Numerical method for evolving the Projected Gross-Pitaevskii equation
In this paper we describe a method for evolving the projected
Gross-Pitaevskii equation (PGPE) for a Bose gas in a harmonic oscillator
potential. The central difficulty in solving this equation is the requirement
that the classical field is restricted to a small set of prescribed modes that
constitute the low energy classical region of the system. We present a scheme,
using a Hermite-polynomial based spectral representation, that precisely
implements this mode restriction and allows an efficient and accurate solution
of the PGPE. We show equilibrium and non-equilibrium results from the
application of the PGPE to an anisotropic trapped three-dimensional Bose gas.Comment: 12 pages, 5 figures. To appear in Phys. Rev. E. Convergence results
added, a few minor changes made and typos fixe
Rotating light, OAM paradox and relativistic complex scalar field
Recent studies show that the angular momentum, both spin and orbital, of
rotating light beams possesses counter-intuitive characteristics. We present a
new approach to the question of orbital angular momentum of light based on the
complex massless scalar field representation of light. The covariant equation
for the scalar field is treated in rotating system using the general
relativistic framework. First we show the equivalence of the U(1) gauge current
for the scalar field with the Poynting vector continuity equation for paraxial
light, and then apply the formalism to the calculation of the orbital angular
momentum of rotating light beams. If the difference between the co-, contra-,
and physical quantities is properly accounted for there does not result any
paradox in the orbital angular momentum of rotating light. An artificial
analogue of the paradoxical situation could be constructed but it is wrong
within the present formalism. It is shown that the orbital angular momentum of
rotating beam comprising of modes with opposite azimuthal indices corresponds
to that of rigid rotation. A short review on the electromagnetism in
noninertial systems is presented to motivate a fully covariant Maxwell field
approach in rotating system to address the rotating light phenomenon.Comment: No figure
Magnonic Crystal with Two-Dimensional Periodicity as a Waveguide for Spin Waves
We describe a simple method of including dissipation in the spin wave band
structure of a periodic ferromagnetic composite, by solving the Landau-Lifshitz
equation for the magnetization with the Gilbert damping term. We use this
approach to calculate the band structure of square and triangular arrays of Ni
nanocylinders embedded in an Fe host. The results show that there are certain
bands and special directions in the Brillouin zone where the spin wave lifetime
is increased by more than an order of magnitude above its average value. Thus,
it may be possible to generate spin waves in such composites decay especially
slowly, and propagate especially large distances, for certain frequencies and
directions in -space.Comment: 13 pages, 4 figures, submitted to Phys Rev
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