1,917 research outputs found
Superconductivity in 2-2-3 system Y2Ba2Cu2O(8+delta)
Researchers synthesized a new high T(sub c) 2-2-3 superconductor Y2Ba2Cu3O(8+delta) by a special preparation technique and characterized it by ac-susceptibility measurements. Diamagnetism and Meissner effect sets in at low fields and superconducting transition onsets at 90 K. The systematic investigation of the real and imaginary components of ac-susceptibility as a function of temperature and applied ac magnetic field reveals that the magnetic behavior is that of a granular type superconductor
() spectroscopy using Cornell potential
The mass spectra and decay properties of heavy quarkonia are computed in
nonrelativistic quark-antiquark Cornell potential model. We have employed the
numerical solution of Schr\"odinger equation to obtain their mass spectra using
only four parameters namely quark mass (, ) and confinement strength
(, ). The spin hyperfine, spin-orbit and tensor
components of the one gluon exchange interaction are computed perturbatively to
determine the mass spectra of excited , , and states. Digamma,
digluon and dilepton decays of these mesons are computed using the model
parameters and numerical wave functions. The predicted spectroscopy and decay
properties for quarkonia are found to be consistent with available experimental
observations and results from other theoretical models. We also compute mass
spectra and life time of the meson without additional parameters. The
computed electromagnetic transition widths of heavy quarkonia and mesons
are in tune with available experimental data and other theoretical approaches
Spherically Symmetric Charged Anisotropic Solution In Higher Dimensional Bimetric General Relativity
In this paper we have obtained a solution of field equations of Rosen’s bimetric general relativity (BGR) for the static spherically symmetric space-time with charged anisotropic fluid distribution in (n+2)-dimensions. An exact solution is obtained and a special case is considered. This work is an extension of our previous work where four-dimensional case was discussed
Prediction of Voltage Stability by Using L � Index in Power System
The prediction of voltage stability experiences sizable anxiety in the safe operation of power system. As power systems grow in their size and interconnections, their complexity increases. Hence, power system voltage stability and voltage control are emerging as major problems in the day to day operation of stressed power system. In this paper investigation of voltage stability index for voltage stability assessment has been discussed. At a normal operating condition L- index gives information about system state. There are so many indicators which predict the system condition. The objective of this paper is to develop a fast and simple method, which can be applied in the power system to estimate the voltage stability margin. Thereby an indicator is derived from the static power flow and Kirchhoff�s-Laws, which is aimed at detection of the voltage instability. This voltage stability index can work well in the static state as well as during dynamic process. It can also be used to find the vulnerable spots of the system. IEEE-14 bus system is used for test set
Superconductivity in 2-2-3 Y2Ba2Cu3O(sub 8+ delta)
Researchers synthesized a new high T(sub c) 2-2-3 superconductor (Y2Ba2Cu3O8+delta) by a special preparation technique and characterized it by ac-susceptibility measurements. Diamagnetism and Meissner effect sets in at low fields and superconducting transition onsets at 90 K. The systematic investigation of the real and imaginary components of ac-susceptibility as a function of temperature and applied ac magnetic field reveals that the magnetic behavior is that of a granular type superconductor
Adverse Effects of Systemic Immunosuppression in Keratolimbal Allograft
Purpose. Keratolimbal allograft (KLAL) is a treatment for limbal stem cell deficiency. One disadvantage is systemic immunosuppression to avoid rejection. Our purpose was to examine the adverse effects of systemic immunosuppression in KLAL. Methods. A retrospective case review of 16 patients with KLAL who received systemic immunosuppression consisting of a corticosteroid, an antimetabolite, and/or a calcineurin inhibitor was performed. Patients were monitored for signs, symptoms, or laboratory evidence of toxicity. Results. Eleven of 16 patients (68%) experienced an adverse effect. The average age of those with adverse effects was 43.5 years and without was 31.4 years. Ten of 11 patients (91%) had resolution during mean followup of 16.4 months. No serious adverse effects occurred. The most common included anemia, hyperglycemia, elevated creatinine, and elevated liver function tests. Prednisone and tacrolimus were responsible for the most adverse effects. Patients with comorbidities were more likely to experience an adverse effect (82% versus 20%, P = 0.036). Conclusions. KLAL requires prolonged systemic immunosuppression. Our data demonstrated that systemic immunosuppression did not result in serious adverse effects in our population and is relatively safe with monitoring for toxicity. In addition, we demonstrated that adverse effects are more likely in older patients with comorbidities
Frequency and distribution of ABO and Rh blood groups among blood donors in tertiary care hospital of South Gujarat, India
Background: Since it was discovered by Karl Landsteiner, the ABO blood group system is the most important blood group system in Transfusion Medicine. The blood group systems are also very important in population genetic studies, researching population migration patterns as well as resolving certain medico-legal issues, particularly disputed parentage. This study was carried out with an objective to provide data regarding gene frequency and distribution of ABO and Rh blood groups among blood donors in South Gujarat, India.Methods: Data of 40732 blood donors were retrospectively collected and analyzed regarding ABO and Rh blood groups from May-2011 to April-2016 and reported in simple numbers and percentage. Blood group of the blood donors was determined by forward and reverse methods with the help of commercially available standard monoclonal antisera by test tube and column agglutination techniques in required cases.Results: The most common blood group among donors was B (34.43%) followed by O (32.26%), A (24.35%), while the least prevalent blood group was AB (8.94%). Rh positivity among donors was (95.12%). Rests were Rh Negative (4.87%). The estimated gene frequencies were 0.1844 for IA (p), 0.2477 for IB (q) and 0.5679 for IO (r).Conclusions: The most common blood group in donors was B positive and least common was AB negative
Implementation of Flow Tripping Capability in the USM3D Unstructured Flow Solver
A flow tripping capability is added to an established NASA tetrahedral unstructured parallel Navier-Stokes flow solver, USM3D. The capability is based on prescribing an appropriate profile of turbulence model variables to energize the boundary layer in a plane normal to a specified trip region on the body surface. We demonstrate this approach using the k-e two-equation turbulence model of USM3D. Modification to the solution procedure primarily consists of developing a data structure to identify all unstructured tetrahedral grid cells located in the plane normal to a specified surface trip region and computing a function based on the mean flow solution to specify the modified profile of the turbulence model variables. We leverage this data structure and also show an adjunct approach that is based on enforcing a laminar flow condition on the otherwise fully turbulent flow solution in user specified region. The latter approach is applied for the solutions obtained using other one- and two-equation turbulence models of USM3D. A key ingredient of the present capability is the use of a graphical user-interface tool PREDISC to define a trip region on the body surface in an existing grid. Verification of the present modifications is demonstrated on three cases, namely, a flat plate, the RAE2822 airfoil, and the DLR F6 wing-fuselage configuration
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