SmFe1-xMnxO3 (x = 0.1, 0.3, 0.5) is synthesized by the sol-gel method. Rietveld refinement of the X-ray diffraction pattern of the materials show crystallization in the orthorhombic structure with ...Pbnm space group. The complex impedance and the ac conductivity of SmFe1-xMnxO3 have been studied by the alternating current impedance spectroscopy method. The conductivity analysis implies that the materials behave as a semiconductor in the entire temperature range. It is observed that with the increase of Mn doping, both the dielectric constant and the conductivity increases whereas the value of loss tangent decreases. The conduction mechanism in these materials has been explained by the correlated barrier hopping (CBH) model. The complex impedance plane plot is analyzed using the Cole-Cole model. The photocatalytic activity of the materials is performed by the degradation of organic pollutant under visible light irradiation. The photocatalytic efficiency of these materials show improvement with the increase in Mn concentration.
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•The enhanced electrical and optical properties of Mn doped SmFeO3 are investigated.•The ac conductivity spectra illustrates the correlated barrier hopping of charge carriers.•The Mn doping enhances the catalytic kinetics which is correlated to the electrical properties.•The enhanced electrical and optical properties can be linked to the decreased band gap.
•Ba1-xLa2x/3TiO3 ceramics have been prepared using standard SSR route.•Compositionally induced structural transition at 6% La substitution.•Onset of relaxor behavior traced at 8% La substituted ...composition.•Presence of shallow defects showed blue luminescence.•Optical band gap reduced with La concentration.
Ba1−xLa2x/3TiO3 (0.00⩽x⩽0.10, in a step of 0.02) ceramics have been prepared through solid state reaction route. Structural studies suggested a transition in phase from tetragonal to cubic symmetry with increase in Lanthanum content. Rietveld Refinement technique employed for investigation confirmed the same. Photoluminescence study revealed introduction of structural disorder by means of A-site vacancies and displacement of M–O bond leading to shallow defects. Optical band gap value calculated from UV–Vis spectra decreased with increase in La concentration. A drastic decrease in grain size of undoped BT was observed with introduction of La through Scanning Electron Micrographs. Dielectric studies were performed and a gradual decrease in the Curie temperature with increase in La content in coherence with structural studies was observed along with pinching effect. Normal ferroelectric character was obtained for the composition x=0.00 to x=0.06 while relaxor like behavior was observed for composition x⩾0.08. The composition x=0.10 made a good Vogel–Fulcher fit. Inhomogeneity induced in the BT lattice due to 8% La doping is strong enough to make an onset of such behavior. P∼E hysteresis loop showed a regular decrease in remnant polarization and coercive field featuring similar relaxor like behavior.
The gut microbiome is associated with diverse diseases
, but a universal signature of a healthy or unhealthy microbiome has not been identified, and there is a need to understand how genetics, ...exposome, lifestyle and diet shape the microbiome in health and disease. Here we profiled bacterial composition, function, antibiotic resistance and virulence factors in the gut microbiomes of 8,208 Dutch individuals from a three-generational cohort comprising 2,756 families. We correlated these to 241 host and environmental factors, including physical and mental health, use of medication, diet, socioeconomic factors and childhood and current exposome. We identify that the microbiome is shaped primarily by the environment and cohabitation. Only around 6.6% of taxa are heritable, whereas the variance of around 48.6% of taxa is significantly explained by cohabitation. By identifying 2,856 associations between the microbiome and health, we find that seemingly unrelated diseases share a common microbiome signature that is independent of comorbidities. Furthermore, we identify 7,519 associations between microbiome features and diet, socioeconomics and early life and current exposome, with numerous early-life and current factors being significantly associated with microbiome function and composition. Overall, this study provides a comprehensive overview of gut microbiome and the underlying impact of heritability and exposures that will facilitate future development of microbiome-targeted therapies.
The neodymium chromate nanoparticles are synthesized by the sol–gel process. The phase formation with
Pnma
symmetry of the sample is confirmed by the Rietveld refinement of X-ray diffraction data. ...The particle size of the sample is determined by transmission electron microscopy. The band gap of the material is found to be 1.78 eV which is obtained by Tauc relation to UV-absorption spectrum. The room temperature Raman spectrum is fitted with the sum of 22 Lorentzian peaks. Dielectric relaxation of the sample has been investigated in the frequency range from 42 Hz to 1.1 MHz and in the temperature range from 303 to 573 K. The Cole–Cole model is used to explain the dielectric relaxation mechanism of the material. The complex impedance plane plot confirms the existence of the grain-boundary contribution to the relaxation of the sample. The frequency-dependent conductivity spectra follow the power law.
This study explored the adsorption capacity of diethylene triamine grafted dialdehyde nanocrystalline cellulose (DETA-g-DA-NCC) for As (III and V) removal from aqueous solution. Nanocrystalline ...cellulose (NCC) was selectively oxidized using sodium periodate followed by grafting of diethylene triamine (DETA) to obtain their amine derivatives in 80–85% yield. A corresponding increase in carbonyl content of the dialdehyde nanocrystalline cellulose (DA-NCC) with the increase in oxidant concentration was measured by titrimetric analysis and was evidenced by FT-IR spectroscopy. Morphological integrity and crystallinity of the NCC were maintained after the functionalization as studied by AFM, SEM and XRD, respectively. The effect of various operational parameters such as arsenic ion concentration, pH, biosorbent dosage and time was investigated using batch experiments and found that DETA-g-DA-NCC can be used as a cost effective biosorbent for decontamination of arsenic. The experimental data were analyzed by Langmuir, Freundlich, Temkin and Dubinin–Redushkevich (D–R) models of sorption. The sorption isotherm data were fitted well to Langmuir isotherm. The kinetic data were fitted very well in the pseudo-second-order kinetic model and suggested that the chemisorptions were the rate-limiting step. The results indicate that there is significant potential for DETA-g-DA-NCC as a biosorbent for arsenic removal As(III) 92.84% and As(V) 97.86% from aqueous solutions.
• Enhanced adsorption as12.06 & 10.02 mg/g for As III & V.• Cost benefits biosorbent.• Green pretreatment step.
Are there any interrelationships between black income and macroeconomic variables? This question is the main motivation behind this study. The study finds that black income in India influences her ...key macroeconomic variables such as the consumption, investment, interest rate and inflation rate. The Bounds test of Cointegration and the Vector Error Correction analysis done in the study demonstrate that black income and the mentioned macroeconomic variables are cointegrated. Besides, the study also demonstrates using Granger causality in a VARX framework that there are interrelationships between black income and the mentioned macroeconomic variables. Black income has lagged impact on itself and on investment. Increases in tax rate and government expenditure increase black income. One of the policy conclusions of the study is that black income should be factored-in in the macroeconomic policy formulation in India.
•Rietveld refinement of X-ray diffraction patterns suggested the coexistence of rhombohedra R3c and Pseudo-tetragonal P4/mmm phases for 20% Sr2+ incorporation in nanostructured BiFeO3 (BFO).•SBFO-30 ...appears to be the best electrode material exhibiting specific capacitance in the range of 1200 F/g at 1 A/g with 89% capacity retention even after 5000 cycles at 5 A/g.•Solidstate asymmetric supercapacitor (ASC) fabricated with SBFO-30//Ni-foam as the positive electrode and carbon nanotube (CNT)//Ni-foam as the negative electrode.•This ASC exhibits specific capacitance as high as 273 F/g at 1 A/g which correspond to the energy and power densities of 97 Wh/Kg and 6.56 KW/Kg, respectively.
Optimization of the electrochemical performance of electro-active species is significantly helpful for fabrication of high performance energy storage device. Since, Bi3+ (A-site) shows electrochemically active features, then energy storage capacity is further improved by Sr2+ doping at A-site. In this work, SrxBi1-xFeO3 (0.05≤x ≤ 0.5) nanostructured electrode materials are synthesized by hydrothermal route. X-ray diffraction (XRD) pattern suggested the coexistence of rhombohedral R3c and tetragonal P4/mmm phases for 20% Sr2+ incorporation in nanostructured BiFeO3 (BFO), which is further correlated with Raman spectroscopy. Of the different Sr2+concentration investigated, the 30% Sr2+ doped BiFeO3 (SBFO-30) appears to be the best electrode material exhibiting specific capacitance in the range of 1200 F/g at 1 A/g with 89% capacity retention even after 5000 cycles at 5 A/g. Further, solidstate asymmetric supercapacitor (ASC) fabricated with SBFO-30//Ni-foam as the positive electrode and carbon nanotube (CNT)//Ni-foam as the negative electrode exhibited specific capacitance as high as 273 F/g at 1 A/g corresponding to the energy and power densities of 97 Wh/Kg and 6.56 KW/Kg, respectively. Thus, among the all investigated electrode materials, SBFO-30 clearly emerged as an excellent electrode material for supercapacitor applications.
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The pursuit for a universal scaling factor to satisfy the time-temperature superposition principle for grain and grain boundary responses has been explored in the ac conductivity domain for ...polycrystalline double perovskite oxides A
2
HoRuO
6
(AHR; A = Ba, Sr, Ca). The samples show different structural phases, from cubic to monoclinic, with decreasing ionic radii. The degree of distortion in the materials is correlated to the strength of the bonding through the bond valence sum (BVS) formalism. The conductivity spectra for all of the samples obey the power law variation. The contribution of different microstructural domains to the conduction process is established. Thermal variation of the dc resistivity points towards a gradual crossover from nearest neighbour to variable range hopping. The activation energies obtained from the dc conductivity, hopping frequency and relaxation frequency show close correlation between the conduction and relaxation mechanisms. The scaled conductivity curves for AHR display the presence of two different conduction processes with dissimilar activation energies in the grain boundary and the grain response regimes. It is thus concluded that a single scaling parameter is insufficient to satisfy the time temperature superposition principle universally when two different thermally activated regions are present simultaneously in the materials.
The realisation of a universal scaling parameter accounting for the time-temperature superposition principle in different electroactive microstructural domains seems improbable.
The disintegrating old open cluster Czernik 3 Sharma, Saurabh; Ghosh, Arpan; Ojha, D K ...
Monthly notices of the Royal Astronomical Society,
10/2020, Volume:
498, Issue:
2
Journal Article
Peer reviewed
Open access
ABSTRACT
We have performed a detailed analysis of the Czernik 3 (Cz3) open cluster by using deep near-infrared photometry taken with TIRCAM2 on the 3.6 m Devasthal optical telescope along with the ...recently available high-quality proper motion data from the Gaia DR2 and deep photometric data from Pan-STARRS1. The cluster has a highly elongated morphology with fractal distribution of stars. The core and cluster radii of the cluster are estimated as 0.5 and 1.2 pc, respectively. We have identified 45 stars as cluster members using the Gaia proper motion data. The distance and age of the cluster are found to be 3.5 ± 0.9 kpc and $0.9^{+0.3}_{-0.1}$ Gyr, respectively. The slope of the mass function `Γ′ in the cluster region, in the mass range ∼0.95 <M/M⊙ < 2.2, is found to be −1.01 ± 0.43. The cluster shows the signatures of mass segregation and is dynamically relaxed (dynamical age = 10 Myr). This along with its small size, big tidal radius, low density/large separation of stars, and elongated and distorted morphology indicates that the Cz3 is a loosely bound disintegrating cluster under the influence of external tidal interactions.
Virology laboratories historically have used direct fluorescent-antibody assay (DFA) and culture to detect six or seven respiratory viruses. Following the discovery of five new human respiratory ...viruses since 2000, there is an increasing need for diagnostic tests to detect these emerging viruses. We have developed a new test that can detect 20 different respiratory virus types/subtypes in a single 5-h test. The assay employs multiplex PCR using 14 virus-specific primer pairs, followed by a multiplexed target-specific primer extension (TSPE) reaction using 21 primers for specific respiratory virus types and subtypes. TSPE products were sorted and identified by using a fluid microsphere-based array (Universal Array; TmBioscience Corporation, Toronto, Canada) and the Luminex x-MAP system. The assay detected influenza A and B viruses; influenza A virus subtypes H1, H3, and H5 (including subtype H5N1 of the Asian lineage); parainfluenza virus types 1, 2, 3, and 4; respiratory syncytial virus types A and B; adenovirus; metapneumovirus; rhinovirus; enterovirus; and coronaviruses OC43, 229E, severe acute respiratory syndrome coronavirus, NL63, and HKU1. In a prospective evaluation using 294 nasopharyngeal swab specimens, DFA/culture detected 119 positives and the respiratory virus panel (RVP) test detected 112 positives, for a sensitivity of 97%. The RVP test detected an additional 61 positive specimens that either were not detected by DFA/culture or were positive for viruses not tested for by DFA/culture. After resolution of discordant results by using a second unique PCR assay and by using a combined reference standard of positivity, the RVP test detected 180 of 183 true positives, for a sensitivity of 98.5%, whereas DFA and culture detected only 126 of 183 true positives, for a sensitivity of 68.8%. The RVP test should improve the capabilities of hospital and public health laboratories for diagnosing viral respiratory tract infections and should assist public health agencies in identifying etiologic agents in respiratory tract infection outbreaks.
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