13,670 research outputs found
Correlation Functions in -Deformed N=6 Supergravity
Gauged N=8 supergravity in four dimensions is now known to admit a
deformation characterized by a real parameter lying in the interval
. We analyse the fluctuations about its anti-de Sitter
vacuum, and show that the full N=8 supersymmetry can be maintained by the
boundary conditions only for . For non-vanishing , and
requiring that there be no propagating spin s>1 fields on the boundary, we show
that N=3 is the maximum degree of supersymmetry that can be preserved by the
boundary conditions. We then construct in detail the consistent truncation of
the N=8 theory to give -deformed SO(6) gauged N=6 supergravity, again
with in the range . We show that this theory
admits fully N=6 supersymmetry-preserving boundary conditions not only for
, but also for . These two theories are related by a
U(1) electric-magnetic duality. We observe that the only three-point functions
that depend on involve the coupling of an SO(6) gauge field with the
U(1) gauge field and a scalar or pseudo-scalar field. We compute these
correlation functions and compare them with those of the undeformed N=6 theory.
We find that the correlation functions in the theory
holographically correspond to amplitudes in the U(N)_k x U(N)_{-k} ABJM model
in which the U(1) Noether current is replaced by a dynamical U(1) gauge field.
We also show that the -deformed N=6 gauged supergravities can be
obtained via consistent reductions from the eleven-dimensional or
ten-dimensional type IIA supergravities.Comment: 38 pages, one figur
Electrolysis-based diaphragm actuators
This work presents a new electrolysis-based microelectromechanical systems (MEMS) diaphragm actuator. Electrolysis is a technique for converting electrical energy to pneumatic energy. Theoretically electrolysis can achieve a strain of 136 000% and is capable of generating a pressure above 200 MPa. Electrolysis actuators require modest electrical power and produce minimal heat. Due to the large volume expansion obtained via electrolysis, small actuators can create a large force. Up to 100 µm of movement was achieved by a 3 mm diaphragm. The actuator operates at room temperature and has a latching and reversing capability
The NN phase shifts in the extended quark-delocalization, color-screening model
An alternative method is applied to the study of nucleon-nucleon(NN)
scattering phase shifts in the framework of extended quark delocalization,
color-screening model(QDCSM), where the one-pion-exchange(OPE) with short-range
cutoff is included.Comment: 5 pages, 3 figures, two-colum
Nonlinear modes and symmetry breaking in rotating double-well potentials
We study modes trapped in a rotating ring carrying the self-focusing (SF) or
defocusing (SDF) cubic nonlinearity and double-well potential , where is the angular coordinate. The model, based on the nonlinear
Schr\"{o}dinger (NLS) equation in the rotating reference frame, describes the
light propagation in a twisted pipe waveguide, as well as in other optical
settings, and also a Bose-Einstein condensate (BEC)trapped in a torus and
dragged by the rotating potential. In the SF and SDF regimes, five and four
trapped modes of different symmetries are found, respectively. The shapes and
stability of the modes, and transitions between them are studied in the first
rotational Brillouin zone. In the SF regime, two symmetry-breaking transitions
are found, of subcritical and supercritical types. In the SDF regime, an
antisymmetry-breaking transition occurs. Ground-states are identified in both
the SF and SDF systems.Comment: Physical Review A, in pres
Contemporary practices of strength and conditioning coaches in professional cricket
This study describes the contemporary practices of strength and conditioning (S&C) coaches in male professional cricket. Thirty-three S&C coaches working with international and professional club teams across seven countries completed an online survey. The survey consisted of 45 questions (35 fixed responses and 10 open-ended), with eight sections: (a) background information, (b) muscular strength and power development, (c) speed development, (d) plyometrics, (e) flexibility development, (f) physical testing, (g) technology use, and (h) programing. Most S&C coaches were educated to degree level (97%) or higher, with 91% of degrees being in a sports science related field. Whereas, 73% held S&C and 40% cricket coaching certifications. Isometric type resistance training exercises (94%) were frequently programed by S&C coaches, with squats and deadlifts (including variations) deemed the most important strength development exercises. Ratings of perceived exertion (58%) was most used for determining set loads. Hang clean (64%) and multiple hops/lunges (85%) were the most prescribed Olympic weightlifting and plyometric exercises. Speed gates (85%) were the most used technology-based equipment. Open-ended questions revealed, 45% of S&C coaches believed time constraints, scheduling and fixtures are the main issues faced in their role. Position specific demands (61%) was the predominant method used for individualizing players training strategies. The information presented in this study is valuable for those pursuing or currently working as a S&C coach in professional cricket to align, compare and explain their practices. Furthermore, will provide insight for the wider athlete support team (i.e., sports coaches, physiotherapists) on the practices of S&C coaches
Can Performance of Indigenous Factors Influence Growth and Globalization?
This paper employs a total of thirty four openness factors and indigenous factors to construct two indicators for 62 world economies for the period 1998-2002. While most globalization studies concentrated on openness factors, regression estimates and simulation studies show that sound performance in indigenous factors are crucial to an economy’s growth and globalization. Empirical evidence shows that an optimal performance in indigenous factors can be identified, and that successful globalized economies are equipped with strong performance in their indigenous factors.Globalization, indigenous factors, openness, world economies
Uniform polynomial rates of convergence for a class of L\'evy-driven controlled SDEs arising in multiclass many-server queues
We study the ergodic properties of a class of controlled stochastic
differential equations (SDEs) driven by -stable processes which arise
as the limiting equations of multiclass queueing models in the Halfin-Whitt
regime that have heavy-tailed arrival processes. When the safety staffing
parameter is positive, we show that the SDEs are uniformly ergodic and enjoy a
polynomial rate of convergence to the invariant probability measure in total
variation, which is uniform over all stationary Markov controls resulting in a
locally Lipschitz continuous drift. We also derive a matching lower bound on
the rate of convergence (under no abandonment). On the other hand, when all
abandonment rates are positive, we show that the SDEs are exponentially ergodic
uniformly over the above-mentioned class of controls. Analogous results are
obtained for L\'evy-driven SDEs arising from multiclass many-server queues
under asymptotically negligible service interruptions. For these equations, we
show that the aforementioned ergodic properties are uniform over all stationary
Markov controls. We also extend a key functional central limit theorem
concerning diffusion approximations so as to make it applicable to the models
studied here
Effects of vesicular-arbuscular mycorrhiza on 14C and 15N distribution in nodulated fababeans
Includes bibliographical references (pages 249-250).A two-compartment growth chamber in which the aboveground plant materials were exposed to 14CO2 and the belowground portion was exposed to 15N2 under normal atmospheric pressure was designed for carbon and nitrogen transfer studies. Vicia faba infected with vesicular-arbuscular fungus Glomus mossae and non-mycorrhizal plants fixed similar quantities of N2 at an age of 6½ wk. Approximately 0.10 mg N was fixed ∙ g−1 dry plant materials ∙ day−1 and 40 mg C • g−1 dry matter day−1 were synthesized by mycorrhizal and non-mycorrhizal fababeans during 48 h exposure to 14CO2 at 6½ wk with no apparent difference in yield of dry matter. The non-mycorrhizal plants transferred 37% of the fixed 14C beneath ground. The mycorrhizal ones transferred 47% of the fixed 14C beneath ground. Most of the difference could be accounted for in the belowground respiration. The 14CO2 produced by root-microbial systems of the mycorrhizal fababeans was twice as great as that of the nonmycorrhizal; both contained active rhizobium
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