2,381 research outputs found
Corrections to the thermodynamics of Schwarzschild-Tangherlini black hole and the generalized uncertainty principle
We investigate the thermodynamics of Schwarzschild-Tangherlini black hole in
the context of the generalized uncertainty principle. The corrections to the
Hawking temperature, entropy and the heat capacity are obtained via the
modified Hamilton-Jacobi equation. These modifications show that the GUP
changes the evolution of Schwarzschild-Tangherlini black hole. Specially, the
GUP effect becomes susceptible when the radius or mass of black hole approach
to the order of Planck scale, it stops radiating and leads to black hole
remnant. Meanwhile, the Planck scale remnant can be confirmed through the
analysis of the heat capacity. Those phenomenons imply that the GUP may give a
way to solve the information paradox. Besides, we also investigate the
possibilities to observe the black hole at LHC, the results demonstrate that
the black hole can not be produced in the recent LHC.Comment: 12 pages, 6 figure
State-independent experimental test of quantum contextuality in an indivisible system
We report the first state-independent experimental test of quantum
contextuality on a single photonic qutrit (three-dimensional system), based on
a recent theoretical proposal [Yu and Oh, Phys. Rev. Lett. 108, 030402 (2012)].
Our experiment spotlights quantum contextuality in its most basic form, in a
way that is independent of either the state or the tensor product structure of
the system
Theoretical investigation of structural, energetic and electronic properties of titanate pyrochlores
Ab initio total energy calculations using the plane-wave pseudopotential method based on density functional theory were carried out to investigate the structural, energetic and electronic properties of A2Ti2O7 (A = La, Gd and Yb) pyrochlores. It turned out that the formation energies of antisite defects are not linearly dependent on the ratio of the cation radii, and, for the three compositions, the cation antisite formation energy is largest for Gd2Ti2O7 pyrochlore. It was indicated that Gd2Ti2O7 compound is the least likely to form defect fluorite structure, which gives rise to the least resistance to radiation-induced amorphization. DOS analysis showed that stronger interaction exists in the Gd2Ti2O7 compound, and its electronic structure is very different from that of La2Ti2O7 and Yb2Ti2O7. Our calculations suggested that the electronic structure of the A cation and bond type should be taken into account when explaining the response behavior of A2Ti2O7 (A = La, Gd, Yb) pyrochlores to ion irradiation-induced amorphization.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58124/2/cm7_34_346203.pd
Properties of metastable alkaline-earth-metal atoms calculated using an accurate effective core potential
The first three electronically excited states in the alkaline-earth-metal
atoms magnesium, calcium, and strontium comprise the (nsnp) triplet P^o_J
(J=0,1,2) fine-structure manifold. All three states are metastable and are of
interest for optical atomic clocks as well as for cold-collision physics. An
efficient technique--based on a physically motivated potential that models the
presence of the ionic core--is employed to solve the Schroedinger equation for
the two-electron valence shell. In this way, radiative lifetimes, laser-induced
clock shifts, and long-range interaction parameters are calculated for
metastable Mg, Ca, and Sr.Comment: 13 pages, 9 table
Assessment of the determinant of choice of ‘over the counter’ analgesics among students of a university in Abbottabad, Pakistan
Purpose: To ascertain the preference of COMSATS Institute of Information Technology, Abbottabad, Pakistan (CIIT) students for various ‘over the counter’ analgesics.Methods: This cross-sectional survey study on self-medication of ibuprofen in students of CIIT was conducted in July - August 2013 using a self-administered questionnaire. Five hundred students with an average age of 20 - 25 years cooperated in this inquisition. The questionnaire contained 18 questions including socio-demographic queries, economical status, perception of the frequency of pain, their locality, and behavior and knowledge of participants on the use of ibuprofen regarding its therapeutic and adverse effects, and interactions.Results: Out of the 500 participants in the study, 70.4 % were female. The response rate was 68.2 %. Ibuprofen (54 %) was the most used analgesic of all the NSAIDs among the respondents. Approximately, 11.2 % of the respondents reported that they suffer from pain almost every day. The younger and more educated respondents had better level of awareness about the ibuprofen’s indications as compared to those who had low level of education. Of the respondents, 29.6 % were not aware of any side effect caused by ibuprofen. Approximately, 22.4 % of the respondents had no knowledge of the interactions of ibuprofen while 61.2 % of the participants consult a physician about painkillers.Conclusion: Although many of the students undergo almost daily pain and favor ibuprofen over other NSAIDs analgesics among but they still lack information on its appropriate handling and safety. The overall result of the survey indicates very low level of information about the drug interaction.Keywords: Pain, OTC, analgesic, ibuprofen, questionnaire based survey, awarenes
Scaling Behavior of the Quantum Phase Transition from a Quantum Anomalous Hall Insulator to an Axion Insulator
The phase transitions from one plateau to the next plateau or to an insulator
in quantum Hall and quantum anomalous Hall (QAH) systems have revealed
universal scaling behaviors. A magnetic-field-driven quantum phase transition
from a QAH insulator to an axion insulator was recently demonstrated in
magnetic topological insulator sandwich samples. Here, we show that the
temperature dependence of the derivative of the longitudinal resistance on
magnetic field at the transition point follows a characteristic power-law that
indicates a universal scaling behavior for the QAH to axion insulator phase
transition. Similar to the quantum Hall plateau to plateau transition, the QAH
to axion insulator transition can also be understood by the Chalker-Coddington
network model. We extract a critical exponent k~ 0.38 in agreement with recent
high-precision numerical results on the correlation length exponent of the
Chalker-Coddington model at v ~ 2.6, rather than the generally-accepted value
of 2.33.Comment: 24 pages, 4 figures, comments are welcom
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