In this research, a facile co-precipitation method was used to synthesize pure and Mg-doped ZnO nanoparticles (NPs). The structure, morphology, chemical composition, and optical and antibacterial ...activity of the synthesized nanoparticles (NPs) were studied with respect to pure and Mg-doped ZnO concentrations (0–7.5 molar (M) %). X-ray diffraction pattern confirmed the presence of crystalline, hexagonal wurtzite phase of ZnO. Scanning electron microscope (SEM) images revealed that pure and Mg-doped ZnO NPs were in the nanoscale regime with hexagonal crystalline morphology around 30–110 nm. Optical characterization of the sample revealed that the band gap energy (
E
g
) decreased from 3.36 to 3.04 eV with an increase in Mg
2+
doping concentration. Optical absorption spectrum of ZnO redshifted as the Mg concentration varied from 2.5 to 7.5 M. Photoluminescence (PL) spectra showed UV emission peak around 400 nm. Enhanced visible emission between 430 and 600 nm with Mg
2+
doping indicated the defect density in ZnO by occupying Zn
2+
vacancies with Mg
2+
ions. Photocatalytic studies revealed that 7.5% Mg-doped ZnO NPs exhibited maximum degradation (78%) for Rhodamine B (RhB) dye under UV-Vis irradiation. Antibacterial studies were conducted using Gram-positive and Gram-negative bacteria. The results demonstrated that doping with Mg ions inside the ZnO matrix had enhanced the antibacterial activity against all types of bacteria and its performance was improved with successive increment in Mg ion concentration inside ZnO NPs.
This paper is motivated by the need to improve the post-Newtonian (PN) amplitude accuracy of waveforms for gravitational waves generated by inspiralling compact binaries, both for use in data ...analysis and in the comparison between post-Newtonian approximations and numerical relativity computations. It presents (i) the non-linear couplings between multipole moments of general post-Newtonian matter sources up to order 3.5PN, including all contributions from tails, tails-of-tails and the non-linear memory effect; and (ii) the source mass-type octupole moment of (non-spinning) compact binaries up to order 3PN, which permits completion of the expressions of the octupole modes and of the gravitational waveform to order 3.5PN. On this occasion we reconfirm by means of independent calculations our earlier results concerning the source mass-type quadrupole moment to order 3PN. Related discussions on factorized resummed waveforms and the occurence of logarithmic contributions to high order are also included.
We compute the tail contributions to the gravitational-wave mode amplitudes for compact binaries in eccentric orbits at the third post-Newtonian order of general relativity. We combine them with the ...already available instantaneous pieces and include the postadiabatic corrections required to fully account for the effects of radiation-reaction forces on the motion. We compare the resulting waveform in the small eccentricity limit to the circular one, finding perfect agreement.
Premature infants exhibit neurodevelopmental delay and reduced growth of the cerebral cortex. However, the underlying mechanisms have remained elusive. Therefore, we hypothesized that neurogenesis in ...the ventricular and subventricular zones of the cerebral cortex would continue in the third trimester of pregnancy and that preterm birth would suppress neurogenesis. To test our hypotheses, we evaluated autopsy materials from human fetuses and preterm infants of 16-35 gestational weeks (gw). We noted that both cycling and noncycling Sox2(+) radial glial cells and Tbr2(+) intermediate progenitors were abundant in human preterm infants until 28 gw. However, their densities consistently decreased from 16 through 28 gw. To determine the effect of premature birth on neurogenesis, we used a rabbit model and compared preterm embryonic day 29 (E29), 3 d old and term (E32, <2 h old) pups at an equivalent postconceptional age. Glutamatergic neurogenesis was suppressed in preterm rabbits, as indicated by the reduced number of Tbr2(+) intermediate progenitors and the increased number of Sox2(+) radial glia. Additionally, hypoxia-inducible factor-1α, vascular endothelial growth factor, and erythropoietin were higher in term than preterm pups, reflecting the hypoxic intrauterine environment of just-born term pups. Proneural genes, including Pax6 and Neurogenin-1 and -2, were higher in preterm rabbit pups compared with term pups. Importantly, neurogenesis and associated factors were restored in preterm pups by treatment with dimethyloxallyl glycine, a hypoxia mimetic agent. Hence, glutamatergic neurogenesis continues in the premature infants, preterm birth suppresses neurogenesis, and hypoxia-mimetic agents might restore neurogenesis, enhance cortical growth, and improve neurodevelopmental outcome of premature infants.
We compute the quadrupole mode of the gravitational waveform of inspiralling compact binaries at the third and half-post-Newtonian (3.5PN) approximation of general relativity. The computation is ...performed using the multipolar post-Newtonian formalism, and restricted to binaries without spins moving on quasi-circular orbits. The new inputs mainly include the 3.5PN terms in the mass quadrupole moment of the source, and the control of required subdominant corrections to the contributions of hereditary integrals (tails and nonlinear memory effect). The result is given in the form of the quadrupolar mode (2, 2) in a spin-weighted spherical harmonic decomposition of the waveform, and may be used for comparison with the counterpart quantity computed in numerical relativity. It is a step towards the computation of the full 3.5PN waveform, whose knowledge is expected to reduce the errors on the location parameters of the source.
The present study presents an experimental study of a prototype counter-flow heat exchanger designed to recover sensible heat from inert and reactive gases flowing through a high temperature solar ...reactor for splitting CO2. The tube-in-tube heat exchanger is comprised of two concentric alumina tubes, each filled with reticulated porous alumina with a nominal porosity of 80% and pore density of 5 pores per inch (ppi). The RPC provides high heat transfer surface area per unit volume (917 m−1) with low pressure drop. Measurements include the permeability, inertial coefficient, overall heat transfer coefficient, effectiveness and pressure drop. For laminar flow and an inlet gas temperature of 1240 K, the overall heat transfer coefficients are 36–41 W m−2 K−1. The measured performance is in good agreement with a prior CFD model of the heat exchanger.
•A ceramic heat exchanger provides gas-phase heat recuperation for a solar thermochemical reactor.•Alumina reticulated porous ceramic (RPC) provides high surface area and low pressure drop.•Heat transfer and pressure drop are measured at temperatures up to 1240 K.•RPC provides a 9-fold increase in heat transfer compared to bare tubes.
Keeping in view the anticancer nature of psyllium and methotrexate, psyllium, if suitably tailored to prepare the hydrogels, can act as the potential candidate for the slow drug delivery systems for ...GI tract. Therefore, the present study is an attempt to modify the psyllium for developing the hydrogels meant for delivery of methotrexate in controlled and sustained manner. The present article discusses the synthesis and characterization of the psy-cl-poly(AAm-co-AAc) hydrogels prepared by chemical crosslinking methods. These hydrogels have been characterized with SEMs, FTIR, TGA, XRD and swelling studies. The swelling and drug release behavior of hydrogels has been determined in solution of different pH. The results indicate that the drug release from the polymeric matrix follows Fickian diffusion mechanism in pH 7.4 buffer.
Distributive justice is known to have important emotional and affective outcomes. The present study explores the role of distributive justice as an antecedent to feelings of gratitude toward the ...organization. Borrowing from social exchange theory, we investigate the mediating role of gratitude in the relationship between “perceived fairness in distributive justice” and “employees’ organization citizenship behaviors (OCB).” Time-lagged, multi-source data was collected from 185 employees and their supervisors employed in a large manufacturing organization based in East India. Two significant findings emerge. First, the results indicate that feelings of gratitude signal fair distribution of benefits such that the employees go beyond the call of the duty to invest in OCB. Second, engagement in such acts seems to nullify their social debts highlighted in the social exchange perspective. Thus, a strong moral emotion, gratitude is a powerful vehicle that drives employees to act in the organization’s interests because doing is desirable and rightful. Implications for theory and practice are discussed.
We compute the nonlinear memory contributions to the gravitational-wave amplitudes for compact binaries in eccentric orbits at the third post-Newtonian (3PN) order in general relativity. These ...contributions are hereditary in nature as they are sourced by gravitational waves emitted during the binary's entire dynamical past. Combining these with already available instantaneous and tail contributions, we get the complete 3PN accurate gravitational waveform.
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