Effect of RF Power on Physical and Electrical Properties of Al-doped ZnO Thin Films

246-253We deposited Al-doped zinc oxide (AZO) thin films on PTFE flexible substrate by RF sputtering with respect to the power in the range 125-155 W. XRD-pattern showed the preferred c-axis (002) orientation regardless the rf-power, which confirmed the hexagonal wurtzite crystal structure. The dislocation density (δ), and strain (ε) of AZO thin films were determined to be 1.861015-0.741015 m-2, and 85.6×10-3-54.0×10-3, respectively. The AZO film deposited at 135 W showed the smooth and uniform microstructure, which is the highest intensity of XRD-pattern due to smaller grain size. The refractive index (n) increased from 2.24 to 2.34, while the bandgap (Eg), and urbach tail (Eu) decreased from 3.66 to 3.31 eV and 0.33 to 0.22 eV as the RF power increased from 125 to 155 W. The sheet resistance and figure of merit (FOM) of AZO thin films were observed to be the lowest 53.36 /cm and 5.17 10-10 -1 for the sample 135 W

Correlation between hematological parameters, blood urea level and mortality of COVID-19 patients.

Aim: Present study was aimed to analyze difference of hematological parameters and blood urea level between Recovered and Dead cases of COVID-19. Material & Methods: A hospital based study was undertaken wherein hematological parameters and blood urea level of 65 cases were analyzed. Results: Recovered patients, 16 (42.1%) showed higher levels of neutrophils with corresponding 22 (57.9%) patients showing normal level of lymphocytes, 25 (65.7%) with normal hemoglobin and 35 (92%) with normal blood urea. On other hand, among 27 Died cases, 26 (96.2%) showed higher counts of neutrophils, 1 patient showed normal lymphocytes (3.8%) and 26 (96.2%) with low count of lymphocytes. Conclusion: In majority of cases, recovered patients showed normal range of lymphocytes (20-45%), hemoglobin and blood urea levels, whereas mortality was observed associated with deficiency of lymphocytes (except one patient all belo

A succession of relaxor ferroelectric transitions in Ba<SUB>0.55</SUB>Sr<SUB>0.45</SUB>TiO<SUB>3</SUB>

We present here the results of frequency dependent dielectric, polarization, and powder x-ray powder diffraction studies in the 300-100 K temperature range for Ba0.55Sr0.45TiO3. The dielectric results indicate a succession of three relaxor ferroelectric transitions accompanying the cubic to tetragonal to orthorhombic to rhombohedral phase transitions confirmed by x-ray diffraction studies

Evidence for a monoclinic M<SUB>A</SUB> to tetragonal morphotropic phase transition in (1-x)[Pb(Fe<SUB>1/2</SUB>Nb<SUB>1/2</SUB>)O<SUB>3</SUB>]-xPbTiO<SUB>3</SUB> ceramics

The results of a powder x-ray diffraction study of the evolution of the crystal structure in pyrochlore-free single-phase powders of (1-x)[Pb(Fe1/2Nb1/2)]O3-xPbTiO3 (PFN-xPT) are presented. Rietveld analysis of the powder diffraction data reveals that the morphotropic phase transition in PFN-xPT corresponds to a change of structure from MA-type monoclinic with Cm space group to tetragonal with P4mm space group at 0.06&lt;x&lt;0.08. It is argued that this monoclinic phase persists in the entire composition range 0.0&#8804;x&#8804;0.06, as evidenced by the presence of anomalous broadening of the 200 profile. The similarity of the morphotropic phase boundary (MPB) in PFN-xPT with that in the Pb(ZrxTi1-x)O3 (PZT) is pointed out

Barrier layer formation and PTCR effect in (1-x) [Pb(Fe<SUB>1/2</SUB>Nb<SUB>1/2</SUB>)O<SUB>3</SUB>]-xPbTiO<SUB>3</SUB>(x=0.13) ceramics

(1-x)Pb(Fe1/2Nb1/2)O3 (PFN-xPT) ceramics with x = 0.13 sintered at 1200°C show diffuse phase transition and very high dielectric constant at lower frequencies. The high value of dielectric constant at lower frequencies is shown to be due to the barrier layer formation. The resistivity of the PFN-xPT ceramics, obtained by complex impedance analysis, initially decreases with temperature and then shows an upward trend beyond the ferroelectric Curie point reminiscent of BaTiO3 based thermistors with PTCR effect

Effectiveness of the chAdOx1 nCoV-19 vaccine in preventing COVID-19 infection

AIM: The study aimed to assess the effectiveness of the ChAdOx1 nCoV-19 vaccine in preventing laboratory-confirmed COVID-19. METHODS: It was a test-negative, case‒control study conducted at Sharda Hospital, Greater Noida, India, between March 2021 and May 2021. An equal number of cases and controls were included in the study after taking proper informed consent. The individuals with positive reverse transcriptase-polymerase chain reaction test reports were taken as cases, whereas those with negative reports were included as controls. Data were analyzed and the groups were compared using multivariable logistic regression to calculate the odds ratio (OR), with adjustment for gender and presence or absence of comorbidities. The effectiveness of vaccine was calculated by the formula (1-adjusted OR) ×100%. RESULTS: On analyzing the data from 560 case‒control pairs, the vaccine effectiveness was calculated as 57.46% (95% confidence interval [CI]: 53.85–61.02) and 60.09% (95% CI: 56.32–63.77) for single dose and two doses, respectively. The effectiveness of complete and single-dose vaccination against the moderate-to-severe disease was calculated as 63.79% (95% CI: 58.58–68.77) and 56.19% (95% CI: 51.30–61.0), respectively. CONCLUSION: The ChAdOx1 nCoV-19 vaccine was found to be effective against COVID-19, with protection after two doses being a little more than that after a single dose. It also proved effective in protecting against the severe form of the disease

Dielectric relaxation and phase transitions at cryogenic temperatures in 0.65[Pb(Ni<SUB>1/3</SUB>Nb<SUB>2/3</SUB>)O<SUB>3</SUB>]-0.35PbTiO<SUB>3</SUB> ceramics

Dielectric measurements on 0.65[Pb(Ni1/3Nb2/3)O3]-0.35PbTiO3 ceramic in the temperature range 90-470 K show a relaxor ferroelectric transition around 350 K with a Vogel-Fulcher freezing temperature of 338 K and an appearance of a nonergodic relaxor ferroelectric phase of tetragonal structure at room temperature. This nonergodic phase reenters into the relaxor state at low temperatures as evidenced by the appearance of a frequency dependent anomaly in the imaginary part of the dielectric constant around 160 K, similar to those reported in other relaxor ferroelectric based morphotropic phase boundary ceramics. The polarization relaxation time for the 160 K anomaly also follows Vogel-Fulcher type temperature dependence. Temperature dependent magnetization measurements show that this low temperature anomaly is not linked with any magnetic transition. Elastic modulus and low temperature x-ray diffraction measurements reveal a tetragonal to monoclinic phase transition around 225 K. It is argued that the low temperature dielectric dispersion around 160 K results from the freezing of mesoscopic conformally miniaturized monoclinic domains formed inside the parent tetragonal domains below the structural phase transition temperature of 225 K

Resolving the characteristics of morphotropic phase boundary in the (1-x)Pb(Fe<SUB>1/2</SUB>Nb<SUB>1/2</SUB>)O<SUB>3</SUB>-xPbTiO<SUB>3</SUB> system: a combined dielectric and synchrotron x-ray diffraction study

Frequency dependent dielectric studies on the mixed system (1-x)Pb(Fe1/2Nb1/2)O3-xPbTiO3 reveal contributions from the electrodes, grain boundaries, and grains. It is shown that the intrinsic value of the dielectric permittivity coming only from the grains peaks at x=0.08. Analysis of synchrotron x-ray diffraction profiles using the Rietveld technique shows that this peaking is linked with a monoclinic to tetragonal morphotropic phase transition in the multiferroic system