Investigation of Complex Impedance and Modulus Properties of Nd Doped 0.5BiFeO3-0.5PbTiO3 Multiferroic Composites

0.5BiNdxFe1-xO3-0.5PbTiO3 (x=0.05, 0.10, 0.15, 0.20) composites were successfully synthesized by a solid state reaction technique. At room temperature X-ray diffraction shows tetragonal structure for all concentrations of Nd doped 0.5BiFeO3-0.5PbTiO3 composites. The nature of Nyquist plot confirms the presence of bulk effects only for all compositions of Nd-doped 0.5BiFeO3-0.5PbTiO3 composites. The bulk resistance is found to decreases with the increasing in temperature as well as Nd concentration and exhibits a typical negative temperature coefficient of resistance (NTCR) behavior. Both the complex impedance and modulus studies have suggested the presence of non-Debye type of relaxation in the materials. Conductivity spectra reveal the presence of hopping mechanism in the electrical transport process of the materials. The activation energy of the composite increases with increasing Nd concentration and were found to be 0.28, 0.27, 0.31 and 0.32eV for x=0.05, 0.10, 0.15, 0.20 respectively at 200-275 oC for conduction process.Comment: 22 pages, 12 figures, 2 tables, 34 Referenc

An observational study of clinicoetiological profile of stroke patients in a new tertiary care hospital in North Odisha, India

Background: Stroke is one of the leading causes of morbidity and mortality in India. The objective was to study the clinical profile, risk factors, neurological characters, pattern of brain stroke, areas of brain affected as per CT scan findings in patients with stroke.Methods: This observational study was carried out from June 2018 to Jan 2019 of all new patients admitted with stroke in Pandit Raghunath Murmu Medical College and Hospital, Baripada, Mayurbhanj, Odisha, India.Results: The incidence of stroke is maximum in 46-60 years of age group. The average age+SD was 59.3+13.5 in our study. 274 (46.52%) patients had ischemic stroke and 315 (53.48%) patients had hemorrhagic stroke. The male to female ratio was 1.46:1. Anterior circulation (86.42%) was the most common territory involved in the brain. The most common risk factor was hypertension with 77.76% followed by dyslipidemia (53.99%). The most common clinical presentation was hemiplegia (85.23%).Conclusions: The incidence of stroke is maximum in 46-60 years of age group. The average age+SD was 59.3+13.5 in our study. 274 (46.52%) patients had ischemic stroke and 315 (53.48%) patients had hemorrhagic stroke. The male to female ratio was 1.46:1. Anterior circulation (86.42%) was the most common territory involved in the brain. The most common risk factor was hypertension with 77.76% followed by dyslipidemia (53.99%). The most common clinical presentation was hemiplegia (85.23%).

Anisotropic ferromagnetism in carbon doped zinc oxide from first-principles studies

A density functional theory study of substitutional carbon impurities in ZnO has been performed, using both the generalized gradient approximation (GGA) and a hybrid functional (HSE06) as exchange-correlation functional. It is found that the non-spinpolarized C$_\mathrm{Zn}$ impurity is under almost all conditions thermodynamically more stable than the C$_\mathrm{O}$ impurity which has a magnetic moment of $2\mu_{\mathrm{B}}$, with the exception of very O-poor and C-rich conditions. This explains the experimental difficulties in sample preparation in order to realize $d^{0}$-ferromagnetism in C-doped ZnO. From GGA calculations with large 96-atom supercells, we conclude that two C$_\mathrm{O}$-C$_\mathrm{O}$ impurities in ZnO interact ferromagnetically, but the interaction is found to be short-ranged and anisotropic, much stronger within the hexagonal $ab$-plane of wurtzite ZnO than along the c-axis. This layered ferromagnetism is attributed to the anisotropy of the dispersion of carbon impurity bands near the Fermi level for C$_{\mathrm{O}}$ impurities in ZnO. From the calculated results, we derive that a C$_{\mathrm{O}}$ concentration between 2% and 6% should be optimal to achieve $d^{0}$-ferromagnetism in C-doped ZnO.Comment: 9 pages, 7 figure

Economics and yield performance of some short duration fruit and medicinal crops under agrisilvicultural system in rainfed uplands of Odisha

A field experiment was conducted during 2011-12 in an agrisilvicultural system consisting of two silvicultural species viz. Acacia mangium (mangium) and Gmelina arborea (gamhar) planted in 2000 at a spacing of 8m x 2m and four agricultural crops viz. Ananas comosus (pineapple), Aloe vera (aloevera), Andrographis paniculata(kalmegh) and Curcuma amada (mangoginger) were raised in the 1st week of July, 2011.The maximum volume increment were achieved by mangium with pineapple (16.53 m3/ha). Pineapple also registered the maximum fruit yield of 9981Kgha-1 under mangium and minimum under gamhar (9106 Kgha-1). The fresh leave yield of aloevera (8635Kg ha-1) was maximum under mangium which is statistically at par with gamhar. However, kalmegh recorded maximum dry plant yield of 1239 Kgha-1 under open condition followed by 1072 Kgha-1 under gamhar and 823 Kgha-1 under mangium. Similarly, mangoginger exhibited maximum rhizome yield of 3300 Kgha-1 under open condition followed by 1979 Kgha-1 under gamhar and 1597 Kgha-1 under mangium. The trend of crop yield under both the trees and open condition was: Pineapple >Aloevera>Mangoginger>Kalmegh. A. mangium with pineapple based agrisilvicultural system recorded the highest gross return, net return and BCR as compared to other agrisilvicultural systems and sole crops

PRELIMINARY PHYTOCHEMICAL SCREENING AND ANTIBACTERIAL EFFICACY STUDIES OF ANNONA SQUAMOSA FRUIT

Objective: The present study was designed to evaluate the antimicrobial activity of lyophilized powder of Annona squamosa fruit. Phytochemical screening was carried out to detect the presence of major phytoconstituents. Methods: Annona squamosa fruit pulps were lyophilized and made into powder, which was diluted with 0.1% DMF. This extract was tested against gram positive and gram negative bacteria employing Agar well diffusion method. Results: The results showed that fruit extract possess antimicrobial activity against microbial isolates. The antibacterial activity increased with increase in mass of fruit extract, which was evidenced through zone of inhibition. The fruit extract showed significant activity when compared with standard positive antibiotic viz. Chloramphenicol (10 µg /disc). The preliminary phytochemical screening tests confirmed the presence of compounds such as alkaloids, terpenoids, flavonoids, steroids, saponins and glycosides as major constituents. Conclusion: Based on the results it is concluded that Annona squamosa has good antimicrobial activity against human pathogens and is also rich in phytochemical constituents

Co3(SO4)3(OH)2[enH2]: a newS= 3/2 Kagome-type layered sulfate with a unique connectivity

The Kagome lattice, comprising a two-dimensional array of corner-sharing equilateral triangles, is central to the exploration of magnetic frustration. In such a lattice, antiferromagnetic coupling between ions in triangular plaquettes prevents all of the exchange interactions being simultaneously satisfied and a variety of novel magnetic ground states may result at low temperature. Experimental realization of a Kagome lattice remains difficult. The jarosite family of materials of nominal composition AM3(SO4)2(OH)6 (A = monovalent cation; M= Fe3+, Cr3+), offers perhaps one of the most promising manifestations of the phenomenon of magnetic frustration in two dimensions. The magnetic properties of jarosites are however extremely sensitive to the degree of coverage of magnetic sites. Consequently, there is considerable interest in the use of soft chemical techniques for the design and synthesis of novel materials in which to explore the effects of spin, degree of site coverage and connectivity on magnetic frustration