Multifunctional Magnetoelectric Materials for Device Applications

Mutiferroics are a novel class of next generation multifunctional materials, which display simultaneous magnetic spin, electric dipole, and ferroelastic ordering, and have drawn increasing interest due to their multi-functionality for a variety of device applications. Since single-phase materials exist rarely in nature with such cross-coupling properties, an intensive research activity is being pursued towards the discovery of new single-phase multiferroic materials and the design of new engineered materials with strong magneto-electric (ME) coupling. This review article summarizes the development of different kinds of multiferroic material: single-phase and composite ceramic, laminated composite, and nanostructured thin films. Thin-film nanostructures have higher magnitude direct ME coupling values and clear evidence of indirect ME coupling compared with bulk materials. Promising ME coupling coefficients have been reported in laminated composite materials in which signal to noise ratio is good for device fabrication. We describe the possible applications of these materials

Magnetic Effects on Dielectric and Polarization Behavior of Multiferroic Hetrostructures

PbZr0.52Ti0.48O3/La0.67Sr0.33MnO3(PZT/LSMO) bilayer with surface roughness ~ 1.8 nm thin films have been grown by pulsed laser deposition on LaAlO3(LAO) substrates. High remnant polarization (30-54 micro C/cm2), dielectric constant(400-1700), and well saturated magnetization were observed depending upon the deposition temperature of the ferromagnetic layer and applied frequencies. Giant frequency-dependent change in dielectric constant and loss were observed above the ferromagnetic-paramagnetic temperature. The frequency dependent dielectric anomalies are attributed to the change in metallic and magnetic nature of LSMO and also the interfacial effect across the bilayer; an enhanced magnetoelectric interaction may be due to the Parish-Littlewood mechanism of inhomogeneity near the metal-dielectric interface.Comment: 9 pages, 4 figure

Global stability of disk-bulge systems: spiral structure of disk galaxies

The spiral arms of disk galaxies are very sensitive to various morphological properties, such as, the gas content, the disk-to-bulge ratioetc. Here, the stability of self-gravitating annular disks surrounding the central rigid bulge component has been studied in order to explain the transition from the tight spiral arms in Sa galaxies to rather open patterns in Sc galaxies as the central amorphous component diminishes. Smooth spiral patterns are found associated with the dominant (or the fastest growing) modes of the system. When the disk-to-bulge mass ratio is small, a tight pattern results restricted to the inner regions of the disk. This pattern opens up and occupies larger disk areas as the disk component becomes comparable to the bulge. It is found here that the 'explosive' instabilities of the global density waves do not occur in the presence of a massive bulge. The growth-rates of the eigen-modes decrease as the disk-to-bulge mass ratio decreases. It is also found that unstable modes of the annular disk can be suppressed by increasing the thermal pressure sufficiently

GLUCOSE HOMEOSTATIC AND PANCREAS PROTECTIVE POTENTIAL OF TECOMELLA UNDULATA ROOT EXTRACT IN STREPTOZOTOCIN INDUCED DIABETIC RATS .

Objective: The study was aimed to evaluate glucose homeostatic and pancreas protective potential of Tecomella undulata root extract in streptozotocin induced diabetic rats.Methods: The ethanolic root extract was prepared by following standard soxhlation methods. The experimental design was divided in to control and treated groups for 28 days of comparative experimental schedule. The body and organ weights, serum biochemistry, histo-pathology, hematology and toxicity profiles were assayed by following standard methods and protocols.Results: The treatment of ethanolic extract of root of T. undulata was significantly (p ≤ 0.001) reduced glucose levels at 7day, 14day, 21day and 28 days in comparison to standard drug of metformin. Correspondingly, lipid profile i.e. total cholesterol, HDL, VLDL, LDL and triglyceride were also altered significantly. Whereas, body and organs weight and hematological parameters were not shown significant changes. Subsequently, toxicity profile i.e. hepatic and renal parameters were remained under normal ranges. Corresponding, the treatment of ethanolic root extract caused normalcy of histoarchitecture of pancreas in comparison to standard drugs.Conclusion: The results of study illustrated that Tecomella undulata root extract possessing particular kind of phytocompounds which caused glucose homeostatic and pancreas protective potential in diabetic rats

EXAMINING THE CRB INDEX AS AN INDICATOR FOR U.S. INFLATION

This paper analyzes historical movements in the commodity futures market and the relationship to inflation. Specifically, the relationship between the Commodity Research Bureau (CRB) Index and United States inflation is investigated. It is said that the relationship between the CRB index and the U.S. inflation rate was greater in the some periods than in another period. Then in recent times the CRB Index has proven to be a reliable early indicator of inflation. As the composition of the United States economy changes, the Commodity Research Bureau must make adjustments in order to provide a viable service.CRB index, Commodities Research Bureau, inflation, Vector Autoregression, Marketing, Public Economics, E00, E30,

Current Status in Cavitation Modeling

Cavitation is a common problem for many engineering devices in which the main working fluid is in liquid state. In turbomachinery applications, cavitation generally occurs on the inlet side of pumps. The deleterious effects of cavitation include: lowered performance, load asymmetry, erosion and pitting of blade surfaces, vibration and noise, and reduction of the overall machine life. Cavitation models in use today range from rather crude approximations to sophisticated bubble dynamics models. Details about bubble inception, growth and collapse are relevant to the prediction of blade erosion, but are not necessary to predict the performance of pumps. An engineering model of cavitation is proposed to predict the extent of cavitation and performance. The vapor volume fraction is used as an indicator variable to quantify cavitation. A two-phase flow approach is employed with the assumption of the thermal equilibrium between liquid and vapor. At present velocity slip between the two phases is selected. Preliminary analyses of 2D flows shows qualitatively correct results