Interaction Of Electric And Magnetic Charges: Addendum

The problem of a head-on collision between a spherically symmetric electric and magnetic charge is reconsidered. The assumption of the equality of the electric and magnetic forces made earlier is abandoned as it does not follow from the model. It is shown that the rotational angular momentum a charge acquires is determined by the amount of the angular momentum which the charge removes from the field by virtue of its extension. The interaction energy of each charge with the dipole it induces in the other charge is equal to the rotational energy of the charge itself. This results in simple expressions for the effective potential, and the distance of closest approach as given by classical electrodynamics and nonrelativistic mechanics. A mechanism is suggested for the transfer of the angular momentum from the field to the monopole. © 1985 The American Physical Society

Thomson\u27s Monopoles

The angular momentum L of the electromagnetic field due to an electric point charge e, and a magnetic point charge (pole) g, is calculated by several methods to obtain J. J. Thomson\u27s result that L = eg/c, and L is directed along the line joining the electric monopole to the magnetic monopole. The relation to Dirac\u27s monopoles is discussed, and particle size is considered. © 1991, American Association of Physics Teachers. All rights reserved

Interaction Of Electric And Magnetic Charges

It is shown classically that in a head-on collision between an electric and a magnetic charge a repulsive polarization force of the form r-5 results (where r is the distance between the charges), if one (both) charge(s) is (are) assigned a finite spherical size. This force leads to a minimum distance of approach and prevents one particle from going through the other, and thus guards against the violation of the conservation of angular momentum. This polarization force is a manifestation of the diamagnetism (diaelectricity) of extended electric (magnetic) charges. © 1977 The American Physical Society

Scattering Of Waves In Many Dimensions

Scattering by a spherical potential is discussed in all dimensions by one formulation using the partial-wave expansion method. The optical theorem relating the total scattering cross section σ to the forward scattering amplitude f(0) is derived

Standstill Electric Charge Generates Magnetostatic Field Under Born-Infeld Electrodynamics

The Abelian Born-Infeld classical non-linear electrodynamic has been used to investigate the electric and magnetostatic fields generated by a point-like electrical charge at rest in an inertial frame. The results show a rich internal structure for the charge. Analytical solutions have also been found. Such findings have been interpreted in terms of vacuum polarization and magnetic-like charges produced by the very high strengths of the electric field considered. Apparently non-linearity is to be accounted for the emergence of an anomalous magnetostatic field suggesting a possible connection to that created by a magnetic dipole composed of two mognetic charges with opposite signals. Consistently in situations where the Born-Infeld field strength parameter is free to become infinite, Maxwell`s regime takes over, the magnetic sector vanishes and the electric field assumes a Coulomb behavior with no trace of a magnetic component. The connection to other monopole solutions, like Dirac`s, t' Hooft`s or Poliakov`s types, are also discussed. Finally some speculative remarks are presented in an attempt to explain such fields.Comment: 11 pages, 3 figures. In this version is update a permanent address of the author L.P.G. De Assis and information on submission publication. Submetted to International Journal of Theoretical Physic

Qualitative study measuring the usability of the International Cardiac Rehabilitation Registry

OBJECTIVE: Cardiac rehabilitation (CR) is a comprehensive model of secondary preventive care. There is a wide variety in implementation characteristics globally, and hence quality control is paramount. Thus, the International Council of Cardiovascular Prevention and Rehabilitation was urged to develop a CR registry. The purpose of this study was to test the perceived usability of the International Cardiac Rehabilitation Registry (ICRR) to optimise it. DESIGN: This was a qualitative study, comprising virtual usability tests using a think-aloud method to elicit feedback on the ICRR, while end-users were entering patient data, followed by semistructured interviews. SETTING: Ultimately, 12 tests were conducted with CR staff (67% female) in low-resource settings from a variety of disciplines in all regions of the world but Europe before saturation was achieved. PRIMARY OUTCOME MEASURE: Participants completed the System Usability Scale. Interviews were transcribed verbatim except to preserve anonymity, and coded using NVIVO by two researchers independently. The Unified Theory of Acceptance and Use of Technology 2 informed analysis. RESULTS: The ICRR was established as easy to use, relevant, efficient, with easy learnability, operability, perceived usefulness, positive perceptions of output quality and high end-user satisfaction. System usability was 83.75, or 'excellent' and rated 'A'. Four major themes were deduced from the interviews: (1) ease of approvals, adoption and implementation; (2) benefits for programmes, (3) variables and their definitions, as well as (4) patient report and follow-up assessment. Based on participant observation and utterances, suggestions for changes to the ICRR were implemented, including to the programme survey, on-boarding processes, navigational instructions, inclusion of programme logos, direction on handling unavailable data and optimising data completeness, as well as policies for authorship and programme certification. CONCLUSIONS: With usability of the ICRR optimised, pilot testing shall ensue

On the equivalence of bound state solutions

In this paper we show the equivalence of various (non-threshold) bound state solutions of branes, or equivalently branes in background potentials, in ten- and eleven-dimensional supergravity. We compare solutions obtained in two very different ways. One method uses a zero mode analysis to make an Ansatz which makes it possible to solve the full non-linear supergravity equations. The other method utilises T-duality techniques to turn on the fields on the brane. To be specific, in eleven dimensions we show the equivalence for the (M2,M5) bound state, or equivalently an M5-brane in a C_3 field, where we also consider the (MW,M2,M2',M5) solution, which can be obtained from the (M2,M5) bound state by a boost. In ten dimensions we show the equivalence for the ((F,D1),D3) bound state as well as the bound states of (p,q) 5-branes with lower dimensional branes in type IIB, corresponding to D3-branes in B_2 and C_2 fields and (p,q) 5-branes in B_2, C_2 and C_4 fields. We also comment on the recently proposed V-duality related to infinitesimally boosted solutions.Comment: 19 pages, LaTe

Dental Anxiety and Fear among Patients in Jazan, Kingdom of Saudi Arabia: A Cross-sectional Study

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