4,987 research outputs found
Thermomechanical properties of a single hexagonal boron nitride sheet
Using atomistic simulations we investigate the thermodynamical properties of
a single atomic layer of hexagonal boron nitride (h-BN). The thermal induced
ripples, heat capacity, and thermal lattice expansion of large scale h-BN
sheets are determined and compared to those found for graphene (GE) for
temperatures up to 1000 K. By analyzing the mean square height fluctuations and the height-height correlation function we found that the h-BN
sheet is a less stiff material as compared to graphene. The bending rigidity of
h-BN: i) is about 16% smaller than the one of GE at room temperature (300 K),
and ii) increases with temperature as in GE. The difference in stiffness
between h-BN and GE results in unequal responses to external uniaxial and shear
stress and different buckling transitions. In contrast to a GE sheet, the
buckling transition of a h-BN sheet depends strongly on the direction of the
applied compression. The molar heat capacity, thermal expansion coefficient and
the Gruneisen parameter are estimated to be 25.2 J\,mol\,K,
7.2K and 0.89, respectively
Interpolation of the Josephson interaction in highly anisotropic superconductors from a solution of the two dimensional sine-Gordon equation
In this paper we solve numerically the two dimensional elliptic sine-Gordon
equation with appropriate boundary conditions. These boundary conditions are
chosen to correspond to the Josephson interaction between two adjacent pancakes
belonging to the same flux-line in a highly anisotropic superconductor. An
extrapolation is obtained between the regimes of low and high separation of the
pancakes. The resulting formula is a better candidate for use in numerical
simulations than previously derived formulas.Comment: 18 pages, 9 figure
Primary prevention of sudden cardiac death in adults with transposition of the great arteries: A review of implantable cardioverter-defibrillator placement
Transposition of the great arteries encompasses a set of structural congenital cardiac lesions that has in common ventriculoarterial discordance. Primarily because of advances in medical and surgical care, an increasing number of children born with this anomaly are surviving into adulthood. Depending upon the subtype of lesion or the particular corrective surgery that the patient might have undergone, this group of adult congenital heart disease patients constitutes a relatively new population with unique medical sequelae. Among the more common and difficult to manage are cardiac arrhythmias and other sequelae that can lead to sudden cardiac death. To date, the question of whether implantable cardioverter-defibrillators should be placed in this cohort as a preventive measure to abort sudden death has largely gone unanswered. Therefore, we review the available literature surrounding this issue
SYNTHESIS, ANTICANCER AND ANTITUBERCULOSIS STUDIES FOR [1-(4-CHLOROPHENYL) CYCLOPROPYL] (PIPERAZINE-YL) METHANONE DERIVATES
Objective: Synthesis, anticancer and antituberculosis studies for 1-(4-Chlorophenyl) cyclopropyl] (piperazin-1-yl) methanone derivates 3a-j
Methods: A series of new [1-(4-Chlorophenyl) cyclopropyl] (piperazin-1-yl) methanone derivates were synthesized using reductive amination method in presence of sodium triacetoxyborohydride to yield piperzine derivatives 3a-j. The structures of all newly synthesized compounds have been characterised by elemental analysis and spectral studies.
Results: Five selected compounds have been screened for invitro anticancer activity against human breast cancer cell line MDA-MB-435 at 10, 20, 40 and 80 µG/mL concentration using sulforhodamine B assay method. and Two compounds 3a and 3c have shown in vitro anticancer activity.
Five selected compounds have been screened for anti-tuberculosis activity using Middlebrook 7H-9 broth and standard strain of M. tb h37Rv. Three compounds 3a, 3b and 3c have shown significant antituberculosis
Conclusion: Synthesis of [1-(4-Chlorophenyl) cyclopropyl] (piperazin-1-yl) methanone derivates 3a-j simple and convenient method. Some of the tested compounds have exhibited significant antituberculosis and anticancer activity. Compound 3c showed both antituberculosis and anticancer activity
Thermodynamics of Ideal Gas in Doubly Special Relativity
We study thermodynamics of an ideal gas in Doubly Special Relativity. New
type of special functions (which we call Incomplete Modified Bessel functions)
emerge. We obtain a series solution for the partition function and derive
thermodynamic quantities. We observe that DSR thermodynamics is
non-perturbative in the SR and massless limits. A stiffer equation of state is
found.Comment: 14 pages, 10 figure
A general partial discretizationmethodology for interlaminar stress computation in composite laminates
A two-point boundary value problem (BVP) is formed in the present work governed by a set of first-order coupled ordinary differential equations (ODEs) in terms of displacements and the transverse stresses through the thickness of laminate (in domain -h/2 < z < h/2) by introducing partial discretization methodology only in the plan area of the three dimensional (3D) laminate. The primary dependent variables in the ODEs are those which occur naturally on a plane z=a constant. An effective numerical integration (NI) technique is utilized for tackling the two-point BVP in an efficient manner. Numerical studies on cross-ply and angle-ply composite plates are performed and presented, involving both validation and solution of new problems
Rate-Limited Quantum-to-Classical Optimal Transport in Finite and Continuous-Variable Quantum Systems
We consider the rate-limited quantum-to-classical optimal transport in terms
of output-constrained rate-distortion coding for both finite-dimensional and
continuous-variable quantum-to-classical systems with limited classical common
randomness. The main coding theorem provides a single-letter characterization
of the achievable rate region of a lossy quantum measurement source coding for
an exact construction of the destination distribution (or the equivalent
quantum state) while maintaining a threshold of distortion from the source
state according to a generally defined distortion observable. The constraint on
the output space fixes the output distribution to an IID predefined probability
mass function. Therefore, this problem can also be viewed as
information-constrained optimal transport which finds the optimal cost of
transporting the source quantum state to the destination classical distribution
via a quantum measurement with limited communication rate and common
randomness.
We develop a coding framework for continuous-variable quantum systems by
employing a clipping projection and a dequantization block and using our
finite-dimensional coding theorem. Moreover, for the Gaussian quantum systems,
we derive an analytical solution for rate-limited Wasserstein distance of order
2, along with a Gaussian optimality theorem, showing that Gaussian measurement
optimizes the rate in a system with Gaussian quantum source and Gaussian
destination distribution. The results further show that in contrast to the
classical Wasserstein distance of Gaussian distributions, which corresponds to
an infinite transmission rate, in the Quantum Gaussian measurement system, the
optimal transport is achieved with a finite transmission rate due to the
inherent noise of the quantum measurement imposed by Heisenberg's uncertainty
principle.Comment: 51 pages, 4 figure
Patelloplasty with and without circumpatellar denervation in reducing anterior knee pain in primary total knee arthroplasty: a comparative prospective study
Background: Anterior knee pain (AKP) following total knee arthroplasty (TKA) is one of the complication which cause dissatisfaction in patients. Incidence estimated to be 4-49%. The aim of our study is to know the efficacy of patelloplasty with circumpatellar denervation with diathermy in reducing AKP in primary TKA.Methods: A total of 130 unilateral TKAs’ are divided into 2 groups. Group I (control) includes 65 patients in which only patelloplasty was done. Group II (intervention) includes 65 patients in which both patelloplasty and circumpatellar denervation with diathermy was done and analysed. Mean follow up period was 18 months. Patients were assessed both preoperatively and postoperatively at final follow up.Results: The overall incidence of AKP at follow up (18 months) was 16.9%, with 7.7% in the intervention group and 26.1% in the control group (p<0.05). Western Ontario and McMaster Universities osteoarthritis index scores were significantly better in intervention group when compared to control group (28.71±3.948 vs 31.40±3.860). Better results were also found in knee society scores for intervention group compared to control group (166.57±7.941 vs 161.23±11.219); Feller patellar score of intervention group was significantly better when compared to control group (23.28±2.546 vs 20.69±3.729); the range of knee flexion was similar in both the groups (94.62±12.6 vs 93.54±10.7). In terms of pain referred by the patient at 72 hrs postoperatively, there was statistically significant difference observed according to visual analogue scale.Conclusions: There is statistically significant difference with respect to AKP in patients who have undergone patelloplasty with circumpatellar denervation using diathermy compared with patelloplasty alone.
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