10 research outputs found
A comprehensive first principles calculations on (Ba0.82K0.18)(Bi0.53Pb0.47)O3 single-cubic-perovskite superconductor
In this present study, the pseudopotential plane-wave (PP-PW) pathway in the
scheme of density functional theory (DFT) is utilized to investigate the
various physical properties on (Ba0.82K0.18)(Bi0.53Pb0.47)O3 (BKBPO) single
perovskite superconductor. We have analyzed elastic constants and moduli at
zero and elevated pressures (up to 25 GPa) as well. We also have investigated
the anisotropic nature incorporating both the theoretical indices and graphical
representations in 2D and 3D dimensions, which reveals a high level of
anisotropy. The flatness of the energy bands near EF is a sign of Van-Hf
singularity that might increase the electron pairing and origination of high-TC
superconductivity. The computed band structure exhibits its metallic
characteristics is confirmed by band overlapping. A band of DOS is formed for
the strong hybridization of the constituent elements. The orbital electrons of
O-2p contribute most dominantly at EF in contrast to all orbital electrons. The
orbital electrons at the EF are higher from both the partial density of states
and charge density mapping investigation. The coexistence of the electron and
hole-like Fermi sheets exhibits the multi-band nature of BKBPO. On the other
hand, Fermi surfaces with flat faces promote transport features and Fermi
surface nesting as well. The calculated value of the electron-phonon coupling
constant ({\lambda} = 1.46) is slightly lower than the isostructural
superconductor, which indicates that the studied BKBPO can be treated as a
strongly coupled superconductor similar to the reported isostructural
perovskite superconductors. Furthermore, the thermodynamic properties have been
evaluated and analyzed at elevated temperature and pressure by using harmonic
Debye approximation (QHDA).Comment: 20 pages, 7 figures, 6 table
A Pettis-Type Integral and Applications to Transition Semigroups
Motivated by applications to transition semigroups, we introduce the notion
of a norming dual pair and study a Pettis-type integral on such pairs. In
particular, we establish a sufficient condition for integrability. We also
introduce and study a class of semigroups on such dual pairs which are an
abstract version of transition semigroups. Using our results, we give
conditions ensuring that a semigroup consisting of kernel operators has a
Laplace transform which also consists of kernel operators. We also provide
conditions under which a semigroup is uniquely determined by its Laplace
transform.Comment: Incorporated referee's comments; final versio
Synthesis of Transparent CuI Thin Films by a Facile Low‐Cost High Pressure (HP)‐PECVD Method at Room Temperature for the Application in Solar Cells
Abstract Copper iodide (CuI) thin films were prepared on a glass substrate by a facile high pressure (HP)‐PECVD method at room temperature. For this, CuI powder was dissolved in CH3CN. The CuI vapor with plasma was investigated by Optical Emission Spectroscopic (OES) data for identifying the species in the plasma. The XRD study reveals the polycrystalline nature of the films. The SEM analyses indicate the homogeneity of the films. The EDS mapping confirms that the thin films mostly consisted of carbon followed by nitrogen, copper and iodine, respectively. The band gaps of CuI thin films were in the range of ~2.71–3.14 eV. The high transmittance and band gap engineering in HP‐PECVD‐synthesized CuI thin films indicates their potential use as window and hole transport layers in low cost solar cells
Management of Patients With Hypertensive Urgencies and Emergencies: A Systematic Review of the Literature
BACKGROUND: Hypertensive urgencies and emergencies are common clinical occurrences in hypertensive patients. Treatment practices vary considerably to because of the lack of evidence supporting the use of one therapeutic agent over another. This paper was designed to review the evidence for various pharmacotherapeutic regimens in the management of hypertensive urgencies and emergencies, in terms of the agents' abilities to reach predetermined “safe” goal blood pressures (BPs), and to prevent adverse events. METHODS: medline was searched from 1966 to 2001, and the reference lists of all the articles were retrieved and searched for relevant references, and experts in the field were contacted to identify other relevant studies. The Cochrane Library was also searched. Studies that were eligible for inclusion in this review were systematic reviews of randomized control trials (RCTs) and individual RCTs, all-or-none studies, systematic reviews of cohort studies and individual cohort studies, and outcomes research. No language restrictions were used. RESULTS: None of the trials included in this review identified an optimal rate of BP lowering in hypertensive emergencies and urgencies. The definitions of hypertensive emergencies and urgencies were not consistent, but emergencies always involved target end-organ damage, and urgencies were without such damage. Measures of outcome were not uniform between studies. The 4 hypertensive emergency and 15 hypertensive urgency studies represented 236 and 1,074 patients, respectively. The evidence indicated a nonsignificant trend toward increased efficacy with urapidil compared to nitroprusside for hypertensive emergencies (number needed to treat [NNT] for urapidil to achieve target BP, 12; 95% confidence interval [95% CI], number of patients needed to harm [NNH], 5 to NNT, 40 compared to nitroprusside). Several medications were efficacious in treating hypertensive urgencies, including: nicardipine (NNT for nicardipine compared to plabebo, 2 in one study [95% CI, 1 to 5] and 1 in another [95% CI, 1 to 1]); lacidipine (NNT, 2; 95% CI, 1 to 8 for lacidipine vs nifedipine) or urapidil (NNT for urapidil compared to enalaprilat and nifedipine, 4; 95% CI, 3 to 6); and nitroprusside and fenoldopam (all patients reached target BP in 2 studies). The studies reported 2 cases of cerebral ischemia secondary to nifedipine. CONCLUSIONS: Many effective agents exist for the treatment of hypertensive crises. Because of the lack of large randomized controlled trials, many questions remain unanswered, such as follow-up times and whether any of the studied agents have mortality benefit