2,014 research outputs found
Magnus Force in High Temperature Superconductivity and Berry Phase
In the topological framework of high temperature superconductivity we have
discussed the Magnus force acting on its vortices
Keypad mobile phones are associated with a significant increased risk of microbial contamination compared to touch screen phones
The use of mobile phones in the clinical environment by healthcare workers has become widespread. Despite evidence that these devices can harbour pathogenic micro-organisms there is little guidance on how to reduce contamination. Recently touchscreen phones with a single flat surface have been introduced. We hypothesise that bacterial contamination of phones used in hospitals will be lower on touchscreen devices compared to keypad devices. Sixty seven mobile phones belonging to health care workers were sampled. The median colony count for touchscreen phones and keypad devices was 0·09 colony forming units (cfu)/cm2 (interquartile range (IQR) 0.05–0·14) and 0·77 cfu/cm2 (IQR range 0·45–3.52) respectively. Colony counts were significantly higher on the keypad phones (Fisher’s exact test p<0.001). Multivariate analysis showed the type of phone (keypad vs. touch screen) was associated with increased colony counts (F-statistic 14.13: p<0.001). Overall, nine (13%) phones grew either meticillin resistant Staphylococcus aureus or vancomycin resistant enterococci. Eight (24%) keypad phones were contaminated with these organisms compared with one touch screen phone (3%). Our data indicate that touchscreen mobile phones are less contaminated than their keypad counterparts, and they are less likely to harbour pathogenic bacteria in the clinical setting
FACt: FORTRAN toolbox for calculating fluctuations in atomic condensates
We develop a FORTRAN code to compute fluctuations in atomic condensates
(FACt) by solving the Bogoliubov-de Gennes (BdG) equations for two component
Bose-Einstein condensate (TBEC) in quasi two dimensions. The BdG equations are
recast as matrix equations and solved self consistently. The code is suitable
for handling quantum fluctuations as well as thermal fluctuations at
temperatures below the critical point of Bose-Einstein condensation. The code
is versatile, and the ground state density profile and low energy excitation
modes obtained from the code can be easily adapted to compute different
properties of TBECs -- ground state energy, overlap integral, quasi particle
amplitudes of BdG spectrum, dispersion relation and structure factor and other
related experimental observables.Comment: The manuscript contains 28 pages and 6 figures. The code including
sample input file and README file can be found in a tar file 'hfb2d2s.tar' by
clicking on the "other formats" in the paper download pag
High Superconductivity, Skyrmions and the Berry Phase
It is here pointed out that the antiferromagnetic spin fluctuation may be
associated with a gauge field which gives rise to the antiferromagnetic ground
state chirality. This is associated with the chiral anomaly and Berry phase
when we consider the two dimensional spin system on the surface of a 3D sphere
with a monopole at the centre. This realizes the RVB state where spinons and
holons can be understood as chargeless spins and spinless holes attached with
magnetic flux. The attachment of the magnetic flux of the charge carrier
suggest, that this may be viewed as a skyrmion. The interaction of a massless
fermion representing a neutral spin with a gauge field along with the
interaction of a spinless hole with the gauge field enhances the
antiferromagnetic correlation along with the pseudogap at the underdoped
region. As the doping increases the antiferromagnetic long range order
disappears for the critical doping parameter . In this framework,
the superconducting pairing may be viewed as caused by skyrmion-skyrmion bound
states.Comment: 10 pages, accepted in Phys. Rev.
Experimental Evaluation of Indoor Localization Methods for Industrial IoT Environment
294-307With the evolution of new technology, GPS brings a lot of revolution in the Localization system but it is not an effective
solution in Indoor Environment. This is because of the fact that the signals coming from the satellite are attenuated,
absorbed, scattered by the walls, roofs, and other objects. Due to this, lots of errors may arise in the system. To overcome
this problem sensor node based localization system is used for mobile IoT domain. Recently, in IoT based system, various
sensor nodes have been used in different kinds of localization based applications such as Location-Based Services (LBS)
and Proximity-Based Services (PBS). However, such sensor nodes may not be stable in every environment to provide an
accurate positioning. Although there are different localization techniques are available to find out the location of any object,
but there is a common challenge of finding best localization technique suitable for most of the environment. This work
investigates different existing indoor localization methods for its practical suitability in Lab and actual Industrial
environment for deployment on IoT nodes. A mobile application has also been developed to implement four state-of-the-art
localization techniques for getting the position and calculating its accuracy in different environments. During the
experiment, BLE Beacons are used as sensor nodes due to their ease of deployment, lower complexity, lower cost, and
higher power consumption. The error in the accuracy of estimated position got calculated in terms of Average Error.
According to the experimental result in real environments it has been revealed that the Weighted Centroid Localization
technique provides better accuracy in industrial as well as laboratory environment
Soft Electromagnetic Radiations from Relativistic Heavy Ion Collisions
The production of low mass dileptons and soft photons from thermalized Quark
Gluon Plasma (QGP) and hadronic matter in relativistic heavy ion collisions is
evaluated. A boost invariant longitudinal and cylindrically symmetric
transverse expansion of the systems created in central collision of lead nuclei
at CERN SPS, BNL RHIC, and CERN LHC, and undergoing a first order phase
transition to hadronic matter is considered. A large production of low mass (M<
0.3 GeV) dileptons, and soft photons (p_T< 0.4 GeV) is seen to emanate from the
bremsstrahlung of quarks and pions. We find an increase by a factor of 2--4 in
the low mass dilepton and soft photon yield as we move from SPS to RHIC
energies, and an increase by an order of magnitude as we move from SPS to LHC
energies. Most of the soft radiations are found to originate from pion driven
processes at SPS and RHIC energies, while at the LHC energies the quark and the
pion driven processes contribute by a similar amount. The study of the
transverse mass distribution is seen to provide interesting details of the
evolution. We also find a unique universal behaviour for the ratio of M^2
weighted transverse mass distribution for M= 0.1 GeV to that for M= 0.2 and 0.3
GeV, as a function of M_T, for SPS, RHIC, and LHC energies, in the absence of
transverse expansion of the system. A deviation from this universal behaviour
is seen as a clear indication of the flow.Comment: Revtex fil
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