ELECTRICAL CONDUCTION, dielectric BEHAVIOR AND MAGNETOELECTRIC EFFECT IN (1-x) Co1.2Mn0.2Fe1.6O4 + (x) BaTiO3 ME Composites

Objective: Electrical and magnetoelectric properties of magnetoelectric (ME) composites ferroelectric as electric component and a mixed ferrite as magnetic component are reported. The (1-x) Co1.2Mn0.2Fe1.6O4 + (x) BaTiO3 magnetoelectric (ME) composite have been prepared using conventional double sintering ceramic process where x varies as 0.00, 0.25, 0.50, 0.75 and 1.00. The X-ray diffraction pattern of the composites reveals the formation of spinel structure for the piezomagnatic phase and tetragonal perovskite structure for the piezoelectric phase without any other phase formation. The dc resistivity was measured as a function of temperature. The variation of dielectric constant ' dielectric loss ε'' and dielectric loss tangent δ with frequency in the range 1kHz-1MHz was studied. The dielectric constant shows dispersion in the lower frequency region, with almost a constant value at higher frequencies. The magnetoelectric voltage coefficient (dE/dH)H was studied as a function of intensity of the magnetic field. The measured magnetoelectric (ME) response demonstrated strong dependence on the volume fraction of CoMnFe2O4 and the applied magnetic field. A large ME voltage coefficient of about 647 Vcm-1Oe-1 was observed for 25% CoMnFe2O4 + 75% BaTiO3composite. Materials and Methods: The piezoelectric phase Barium Titanate (BaTiO3) was prepared by standard doubling sintering ceramic method using AR grade oxides/carbonate. Barium carbonate (BaCO3) and Titanium-dioxide (TiO2) were taken in molar proportion. Results: The electrical resistivity of ferrite phase is less as compared to the resistivity of ferroelectric material. The resistivity of composites is found to be in between ferrite and ferroelectric. Conclusion: Magneto-electric conversion factor with varying magnetic field shows maxima in the curve at a lower magnetic field and then decreases continuously at higher magnetic field. As ferroelectric content increases both the resistivity and magnetoelectric conversion factor also increases

String Fluid Cosmological Model with Magnetic Field in Bimetric Theory of Gravitation

In this paper, LRS Bianchi type I string fluid cosmological model with magnetic field in bimetric theory of gravitation is investigated by assuming barotropic equation of state for pressure and density and assuming the bulk viscosity to be inversely proportional to the scalar expansion. The source of energy momentum tensor is a bulk viscous fluid containing one dimensional string with electromagnetic field. The physical and geometrical properties of the model are discussed. The bulk viscosity affected the whole properties of the model

Non-Inflationary Bianchi Type VI0 Model in Rosen’s Bimetric Gravity

In this paper, we have present the solution of Bianchi type VI0 space-time by solving the Rosen’s field equations with massless scalar field φ and with constant scalar potential V(φ) for flat region. It is observed that the scalar field φ is an increasing function of time and affects the physical parameters of the model and leads to non-inflationary type solution of model, which contradicts the inflationary scenario. Other geometrical and physical properties of the model in relation to this non-inflationary model are also studied

Application of Neural Networks in Sign Language Gesture Recognition

Neural Networks have a wide range of applications in the area of gesture recognition. This research gives a method to recognize English alphabets from A to Z in real-time using Neural Networks from a database of signs performed by a signer using a camera. A feature vector giving the dimensions of each sigh is calculated and processed using Neural Networks. The methodology is carried out using MATLAB 7.0 software

Land resource assessment for agricultural development in Seoni district (Madhya Pradesh), India

The objective of land resource assessment for rainfed agridevelopment in tribal dominated Seoni ditrict, Madhya Pradesh was to assess the suitability of thrity soil mapping units for sorghum-cotton based systems in relation to fertility constraints and for enhancing crop productivity. The arability and suitability analysis showed that fifty six per cent of arable land is suitable for eleven land use systems. The twenty two per cent of arable basaltic lands in northen plateaus were evaluated as suitable for for citrus, sorghum and soybean cropping systems with limitations of low available nitrogen, phosphorus and zinc whereas in southern precipitous zone , fifteen per cent of granitic lands were evaluated as suitable for sorghum and cotton with limitations of stoniness, low water holding capacity, low status of available nitrogen, phosphorus, potassium and zinc and eighteen per cent of area in sagar and hirvi river valleys for rice, citrus, maize, sunflower and vegetables. Out of 44.6 per cent of nonarable land, thirty seven per cent of land was evaluated as suitable for forestry / grazing and 6.8 per cent for wild life.The study advocates agroecological zonation for maximum utilization of land resources for potential cropping systems in improving produvtivity and fertility management

Chemoselective C-benzoylation of phenols by using AlCl3 under solvent-free conditions

Substituted phenols were chemo-selectively reacted with benzoylchloride in presence of aluminum chloride under solvent-free condition to afford the corresponding 2'-hydroxy aryl benzophenones in excellent yields (72-96%). Naphthol benzoylation resulted in lower yields as compared to phenols. Both reactions completed in 5-10 min with quantitative yields providing excellent control over regioselectivity of products. KEY WORDS: Chemoselective C-acylation, F-C reaction, Fries rearrangement Bull. Chem. Soc. Ethiop. 2015, 29(2), 319-325DOI: http://dx.doi.org/10.4314/bcse.v29i2.1