6,388 research outputs found
Simple system to measure the Earth's magnetic field
Our aim in this proposal is by using the Faraday's law of induction as a
simple lecture demonstration to measure the Earth's magnetic field (B). This
will also enable the students to learn about how electric power is generated
from the rotational motion. Obviously the idea is not original, yet it may be
attractive in the sense that no sophisticated devices are used
Negative differential Rashba effect in two-dimensional hole systems
We demonstrate experimentally and theoretically that two-dimensional (2D)
heavy hole systems in single heterostructures exhibit a \emph{decrease} in
spin-orbit interaction-induced spin splitting with an increase in perpendicular
electric field. Using front and back gates, we measure the spin splitting as a
function of applied electric field while keeping the density constant. Our
results are in contrast to the more familiar case of 2D electrons where spin
splitting increases with electric field.Comment: 3 pages, 3 figures. To appear in AP
Social media usage in academic research
Recently researchers have used “conversation prism” and “social media prisma”, to consolidate social medias with respect to their use. Although both identified 25 types, having average five examples each, they did not identify contribution of each type in academic research. Moreover some of mentioned social services had been suspended or changed. In this paper we attempt to access each social media mentioned in conversation prism in order to first, identify services that are operational to date, services which have suspended and those which have changed during course of time. Second, we compare number of publications associated with each social media, in order to identify which social media has contributed most to academic research. Third, we attempt to find correlation between number of publications and development tools provided by respective social applications. Fourth, social medias are ranked with respect to number of times other social medias share content with respective social application. It was found that out of 168 social applications, 10% changed their service objective while 13% were suspended. Among all social application, AMAZON had highest i.e. 147,000 number of citations on Google scholar whereas 90.7% of total citations were contributed by top 30 social medias. For developers, 22 out of top 30 social medias provided developer options in form of either application programming interface (API) or software development kits (SDK) and Facebook was found to be most cross referred social media based on content sharing. Finally conclusion and future work of study is presented
An Adaptive Energy Efficient Reliable Routing Protocol for Wireless Sensor Network
Wireless sensor networks are networks of tiny sensing devices for communicating in using wireless technology. Wireless sensor networks are deployed in scenarios where any plant information should be available for industrial control applications. Cross-layer interaction is most important factor to gain maximum efficiency and also able to provide difficult interaction among the layers of the protocol stack. Hence to achieve this is challenging issue because latency, energy and reliability are at odds, and also resource constrained does not support complex algorithm. Wireless sensor networks have many protocols. In this paper Breath protocol is proposed for industrial control application .To minimizing energy consumption in network breath is designed for WSNs by which nodes attached to plants must carry information via through multi hop routing to sink. To optimize energy efficiency the protocol is based on randomized routing, medium access control, and duty-cycling. Alternate model of breath protocol ensures a long lifetime of the network by making effective distribution of workload in sensor nodes. Hence it shows as a good terminology for efficient, timely data gathering for industrial control applications.
DOI: 10.17762/ijritcc2321-8169.15032
Dilatonic interpolation between Reissner-Nordstrom and Bertotti-Robinson spacetimes with physical consequences
We give a general class of static, spherically symmetric, non-asymptotically
flat and asymptotically non-(anti) de Sitter black hole solutions in
Einstein-Maxwell-Dilaton (EMD) theory of gravity in 4-dimensions. In this
general study we couple a magnetic Maxwell field with a general dilaton
potential, while double Liouville-type potentials are coupled with the gravity.
We show that the dilatonic parameters play the key role in switching between
the Bertotti-Robinson and Reissner-Nordstr\"om spacetimes. We study the
stability of such black holes under a linear radial perturbation, and in this
sense we find exceptional cases that the EMD black holes are unstable. In
continuation we give a detailed study of the spin-weighted harmonics in
dilatonic Hawking radiation spectrum and compare our results with the
previously known ones. Finally, we investigate the status of resulting naked
singularities of our general solution when probed with quantum test particles.Comment: 27 pages, 4 figures, to appear in CQG
Periodic Instantons in SU(2) Yang-Mills-Higgs Theory
The properties of periodic instanton solutions of the classical SU(2) gauge
theory with a Higgs doublet field are described analytically at low energies,
and found numerically for all energies up to and beyond the sphaleron energy.
Interesting new classes of bifurcating complex periodic instanton solutions to
the Yang-Mills-Higgs equations are described.Comment: 11 pages, 3 figures (in 5 included eps files), ReVTeX (minor typos
corrected and reference added
Parental [correction of Perinatal] consanguinity: a risk factor for developmental delay in Pakistani children
Objective: To investigate the association of parental consanguinity and delayed development in terms of gross motor, fine motor, speech and social aspects in their children.Methods: One hundred and seventy seven children (age 15 days--72 months) were evaluated for their developmental status utilizing the Denver Developmental Screening Test (DDST). An unmatched case-control study design was used. Case group consisted of 94 children and control group 83 children. Odds ratios were calculated for parental consanguinity and delay in gross and fine motor, speech and social development in their children, for cases and controls, utilizing Binary Multiple Logistic Regression Analysis. Acquired delay was excluded through detailed birth history in both cases and control group respectively.Results: Univariate analysis showed high significant Odds ratios for all areas of developmental delay (viz. gross and fine motor, speech and social development), between cases and controls (p \u3c .001). At the multivariate analysis level however, our results showed no increased risk of parental consanguinity on delayed gross and fine motor, speech and social development in their children.Conclusion: Our results show no increased risk of parental consanguinity on delayed gross and fine motor, speech or social development (as measured by the DDST), in their children
Stochastic approach to inflation II: classicality, coarse-graining and noises
In this work we generalize a previously developed semiclassical approach to
inflation, devoted to the analysis of the effective dynamics of coarse-grained
fields, which are essential to the stochastic approach to inflation. We
consider general non-trivial momentum distributions when defining these fields.
The use of smooth cutoffs in momentum space avoids highly singular quantum
noise correlations and allows us to consider the whole quantum noise sector
when analyzing the conditions for the validity of an effective classical
dynamical description of the coarse-grained field. We show that the weighting
of modes has physical consequences, and thus cannot be considered as a mere
mathematical artifact. In particular we discuss the exponential inflationary
scenario and show that colored noises appear with cutoff dependent amplitudes.Comment: 18 pages, revtex, no figure
Stochastic Inflation:The Quantum Phase Space Approach
In this paper a quantum mechanical phase space picture is constructed for
coarse-grained free quantum fields in an inflationary Universe. The appropriate
stochastic quantum Liouville equation is derived. Explicit solutions for the
phase space quantum distribution function are found for the cases of power law
and exponential expansions. The expectation values of dynamical variables with
respect to these solutions are compared to the corresponding cutoff regularized
field theoretic results (we do not restrict ourselves only to \VEV{\F^2}).
Fair agreement is found provided the coarse-graining scale is kept within
certain limits. By focusing on the full phase space distribution function
rather than a reduced distribution it is shown that the thermodynamic
interpretation of the stochastic formalism faces several difficulties (e.g.,
there is no fluctuation-dissipation theorem). The coarse-graining does not
guarantee an automatic classical limit as quantum correlations turn out to be
crucial in order to get results consistent with standard quantum field theory.
Therefore, the method does {\em not} by itself constitute an explanation of the
quantum to classical transition in the early Universe. In particular, we argue
that the stochastic equations do not lead to decoherence.Comment: 43 page
The Nonlinear Cosmological Matter Power Spectrum with Massive Neutrinos I: The Halo Model
Measurements of the linear power spectrum of galaxies have placed tight
constraints on neutrino masses. We extend the framework of the halo model of
cosmological nonlinear matter clustering to include the effect of massive
neutrino infall into cold dark matter (CDM) halos. The magnitude of the effect
of neutrino clustering for three degenerate mass neutrinos with m_nu=0.9 eV is
of order ~1%, within the potential sensitivity of upcoming weak lensing
surveys. In order to use these measurements to further constrain--or eventually
detect--neutrino masses, accurate theoretical predictions of the nonlinear
power spectrum in the presence of massive neutrinos will be needed, likely only
possible through high-resolution multiple particle (neutrino, CDM and baryon)
simulations.Comment: v2: matches PRD versio
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