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

Raman spectra and Magnetization of all-ferromagnetic superlattices grown on (110) oriented SrTiO3

Superlattices consist of two ferromagnets La0.7Sr0.3MnO3(LSMO)and SrRuO3(SRO) were grown in (110)-orientation on SrTiO3(STO) substrates. The x-ray diffraction and Raman spectra of these superlattices show the presence of in-plane compressive strain and orthorhombic structure of less than 4 u.c. thick LSMO spacer,respectively. Magnetic measurements reveal several features including reduced magnetization, enhanced coercivity, antiferromagnetic coupling, and switching from antiferromagnetic to ferromagnetic coupling with magnetic field orientations. These magnetic properties are explained by the observed orthorhombic structure of spacer LSMO in Raman scattering which occurs due to the modification in the stereochemistry of Mn at the interfaces of SRO and LSMO

Vibration Analysis of a Beam using Neural Network Technique

Using changes in global dynamic characteristics for detection of cracks has been a hot research topic now a days and is a source of attraction for civil, aerospace, and mechanical engineering communities in recent years. Crack in vibrating components causes a change in physical properties of a structure which in turn affects dynamic response characteristics. Therefore we have to study the dynamic response characteristics in order to avoid any catastrophic failures and to follow structural integrity and performance for which the parameters considered are crack depth and its location. In the present study, vibration analysis is carried out on a cantilever beam with two open transverse cracks, to study the response characteristics. Its natural frequency and mode shapes are determined by applying suitable boundary conditions. The results obtained numerically are compared with the results obtained from the simulation. The simulations have done with the help of ALGOR software. Then by using Feed-forward, back propagation neural network the relationship between the location and the depth of the crack as input and the structural eigenfrequencies as output are studied. At the end by performing both the simulation and computational analysis it is proved that the presence of cracks affects the natural frequency and the mode shapes of the structure. The results indicate that the current approach can identify both the location and the extent of damages in the beam

Comparative study of serum electrolytes Na+, K+, Ca++ in patients of chronic kidney disease in relation to its severity

Background: Chronic kidney disease (CKD) is a worldwide public health problem. Globally, CKD is the 12th cause of death and the 17th cause of disability, respectively. Yearly incidence of ESRD in India is approximately 150-200 pmp.Methods: The observational study was conducted in Department of General Medicine, Pandit Raghunath Murmu Medical College Hospital, Baripada between May 2018 and January 2019. 244 patients of Chronic Kidney Disease above 15 years of age satisfying the inclusion and exclusion criteria were included in the study.Results: Study group constitutes 64.34% (157) of male and 35.66% (87) of female patients with M:F of 1.8:1. The average age of the patients in the study was 55.91±12.49 yrs. 42.21% (103) of the patients were between 46 and 60 years of age. Maximum number of cases (190 cases) (77.87%) are in stage 4 and 5 with e-GFR <30 ml/ min. The average serum electrolytes in this study group for serum sodium, potassium, calcium are 137.31±10.05 mEq/L, 4.12±1.48 mEq/L and 1.10±0.19 mmol/L respectively. When association of hypokalemia with risk factor (known and unknown) is compared, chi-square value found to be 13.664 (p=0.0002) which is statistically extremely significant.Conclusions: Authors found significant number of cases, more commonly younger patients, presented with atypical manifestations having no specific etiology; the cause may be defect in rennin-angiotensin system or, may be genetic or, may be environmental