Improved AC-Resistance of Multiple Foil Windings by Varying Foil Thickness of Successive Layers

Abstract: A novel optimization strategy for planar inductor design, based on a per-layer approach for calculation of the optimal foil thickness is presented in this paper. Implementation of this strategy results in reduced ac- and dcresistance of the winding. Inductor windings optimized for sinusoidal excitation were constructed and the resistance measured. Results are shown for air core inductors and the performance of the same windings in gapped magnetic cores is also reported. An optimisation technique for non-sinusoidal excitation is also proposed. Air gap proximity losses can be reduced by notching the winding in the region of the air gap. This technique combined with the newly proposed layer optimisation strategy is also investigated for a trapezoidal current waveform

Dynamics of D1-brane in I-brane Background

This paper is devoted to the study of the effective field theory description of the probe D1-brane in the background of the system of two stacks of fivebranes in type IIB theory that intersect on $R^{1,1}$. We study the properties of the Dirac-Born-Infeld action for D1-brane moving in this background. We will argue that this action is invariant under an additional symmetry in the near horizon limit and that this new symmetry is closely related to the enhanced symmetry of the I-brane background considered recently in [hep-th/0508025]. We also solve explicitly the equation of motion of D1-brane in the near horizon limit.Comment: 21 pages, references adde

Soft functions for generic jet algorithms and observables at hadron colliders

We introduce a method to compute one-loop soft functions for exclusive N - jet processes at hadron colliders, allowing for different definitions of the algorithm that determines the jet regions and of the measurements in those regions. In particular, we generalize the N -jettiness hemisphere decomposition of ref. [1] in a manner that separates the dependence on the jet boundary from the observables measured inside the jet and beam regions. Results are given for several factorizable jet definitions, including anti-k T , XCone, and other geometric partitionings. We calculate explicitly the soft functions for angularity measurements, including jet mass and jet broadening, in pp → L + 1 jet and explore the differences for various jet vetoes and algorithms. This includes a consistent treatment of rapidity divergences when applicable. We also compute analytic results for these soft functions in an expansion for a small jet radius R. We find that the small-R results, including corrections up to O(R2), accurately capture the full behavior over a large range of R

Strings between branes

D-brane configurations containing fundamental strings are constructed as classical solutions of Yang-Mills theory. The fundamental strings in these systems stretch between D-branes. In the case of D1-branes, this construction gives smooth (classical) resolutions of string junctions and string networks. Using a non-abelian Yang-Mills analysis of the string current, the string charge density is computed and is shown to have support in the region between the D-brane world-volumes. The 't Hooft-Polyakov monopole is analyzed using similar methods, and is shown to contain D-strings whose flux has support off the D-brane world-volume defined by the Higgs scalar field, when this field is interpreted in terms of a transverse dimension. The constructions presented here are used to give a qualitative picture of tachyon condensation in the Yang-Mills limit, where fundamental strings and lower-dimensional D-branes arise in a volume of space-time where brane-antibrane annihilation has occurred.Comment: 35 pages, 16 eps figures, JHEP style; v2: a comment adde

The hierarchical stability of the seven known large size ratio triple asteroids using the empirical stability parameters

In this study, the hierarchical stability of the seven known large size ratio triple asteroids is investigated. The effect of the solar gravity and primary’s J(2) are considered. The force function is expanded in terms of mass ratios based on the Hill’s approximation and the large size ratio property. The empirical stability parameters are used to examine the hierarchical stability of the triple asteroids. It is found that the all the known large size ratio triple asteroid systems are hierarchically stable. This study provides useful information for future evolutions of the triple asteroids

Transverse Fivebranes in Matrix Theory

M-theory on the maximally supersymmetric plane wave background of eleven-dimensional supergravity admits spherical BPS transverse M5-branes with zero light-cone energy. We give direct evidence that the single M5-brane state corresponds to the trivial (X=0) classical vacuum in the large N limit of the plane wave matrix theory. In particular, we show that the linear fluctuation spectrum of the spherical fivebrane matches exactly with the set of exactly protected excited states about the X=0 vacuum in the matrix model. These states include geometrical fluctuations of the sphere, excitations of the worldvolume two-form field, and fermion excitations. In addition, we propose a description of multiple fivebrane states in terms of matrix model vacua. Finally, we discuss how to obtain the continuum D2/M2 and NS5/M5 theories on spheres from the matrix model. The matrix model can be viewed as a regularization for these theories.Comment: Latex file, 2 eps figures, 22 pages; v2: typo correcte

Acoustic loading beneath hypersonic transitional and turbulent boundary layers

This paper concerns a study of pressure fluctuations beneath hypersonic transitional and turbulent boundary layers and associated acoustic loading on a flat surface. We have employed high-order implicit large eddy simulations in conjunction with the atmospheric (von Kármán) multimode energy spectrum as initial condition, and conducted simulations at Mach 4, 6 and 8 and for different inflow turbulence intensities. The spectral analysis of the pressure fluctuations shows consistent results with the available theoretical, experimental and numerical data for fully turbulent boundary layers. In the transition region the spectrum roll-off diverges from the existing scaling predictions for incompressible, as well as fully-turbulent compressible flows. This study shows that the spectrum in the transition region is governed by different scaling laws. The Mach number has a direct impact on the spectrum for both transitional and fully turbulent flows, especially in the high-frequency region of the spectrum. Increasing the inlet turbulence intensity leads to higher amplitude pressure fluctuations in the mid-to-high-frequency region, faster transition to turbulence, and higher acoustic loading on the solid surface

A carbonate-banded iron formation transition in the Early Protorezoicum of South Africa

Seven new and two resurveyed stratigraphic sections through the important carbonate-BIF transition in Griqualand West are presented and compared with six published sections. Lateral correlation within this zone is attempted but the variability was found to be too great for meaningful subdivision. Substantial lithological irregularity is the only unifying character of this zone, for which the new name Finsch Member (Formation) is proposed. Vertical and lateral lithological variations as well as chemical changes across this zone are discussed with reference to environmental aspects. Local and regional considerations lead to the conclusion that fresh water-sea water mixing occurred in a shallowing basin

Use of herbal medicines among pregnant women a attending antenatal clinic at Kiryandongo General Hospital, Uganda

Objective: To assess the knowledge and use of herbal medicines among pregnant women attending the antenatal clinic at Kiryandongo general hospital.Design: A descriptive cross-sectional studySetting: Kiryandongo general hospital in Masindi District, mid-western Uganda.Subjects: Four hundred (400) pregnant women attending antenatal care (ANC) were interviewed about their knowledge and use of herbal medicines during pregnancy using self-administered questionnaires, during the months of July and August 2013.Results: Of the 400 women who participated in the study, majority 246 (61.5%)was in the age range of 18 to 24 years old, married 379 (94.8%), stayed in a rural setting 293 (73.3%),had attained primary education 239(59.8%),peasant farmers 209 (52.3%), in monogamous marriage 247 (64.2%), of prime gravidae 117 (29.2%), and Banyoro by tribe 89 (22.3%). Three hundred and fifty (87.5%)of the respondents reported to have ever heard about the use of herbal medicines during pregnancy, with 169 (48.3%) reported having used herbal medicines during previous pregnancies or in the months prior to the study. One hundred and thirty two (37.7%) where found to be using herbal medicines at the time of the study, with the majority of them one hundred and eleven (84.1%) admitting that they will be using herbal medicines again in subsequent pregnancies. One hundred and fifty three (43.7%)considered herbal medicines to be safe during pregnancy and preferred them to conventional medicines because they have low side effects, are cheap and easy to access, and it is part of their tradition to use them during pregnancy.One hundred and ten (31.4%) believed that these herbs are neither dangerous to the mother nor the foetus.Conclusion: More efficient ways are required to educate the general population about the dangers of self-medication during pregnancy especially to advise pregnant mothers not to expose their unborn child to the risks of herbal medicines. Pharmacological and case control studies will be vital in assessing the efficacy and risks associated with herbal medicine use during pregnancy. Midwives, obstetricians and General Practitioners should facilitate women’s wishes without condemnation, but this must be tempered with accurate information