Tailoring of ferromagnetic Pr0.85Ca0.15MnO3/ferroelectric Ba0.6Sr0.4TiO3 superlattices for multiferroic properties

Superlattices composed of ferromagnetic Pr0.85Ca0.15MnO3 and ferroelectric Ba0.6Sr0.4TiO3 layers were fabricated on (100) SrTiO3 substrates by a pulsed-laser deposition method. The capacitance and resistive parts of the samples were analyzed from the complex impedance measurements, performed on the samples using a special experimental set-up. The superlattice with larger ferroelectric thickness shows unique characteristics which are not present in the parent ferromagnetic thin film. The superlattice show both ferromagnetic and ferroelectric transitions which is an evidence for the coexistence of both the properties. The high magnetoresistance (40 % at 80K) shown by the superlattice can be attributed to the coupling between ferromagnetic and ferroelectric layers, i.e, to the magnetoelectric effect.Comment: To be published in App. Phys. Let

Characterization of clean and fouled ultrafiltration membranes

Much research into the fundamentals of membrane formation and separation has been performed in order to improve the efficiency of the manufacture of ultrafiltration membranes. Determination of the membrane characteristics is a key problem in these investigations. In this paper, we report on a study of membrane morphology by fractional rejection measurements, using low molecular weight saccharides as the test solute, and by electron microscopy. Using a simple model for solute/solvent transport through cylindrical pores, a “characteristic pore size” was derived from saccharide rejection data. This pore size of a hypothetical isoporous membrane, interpreting the measured separation characteristics, provides a promising means of describing differences between membranes with respect to pore size and pore size changes caused by solute adsorption. From high resolution electron micrographs, information was obtained on the skin layer morphologies and, for some membranes the sizes of the larger pores could be estimated

The betrayal of Anne Frank: a refutation

Political Culture and National Identit

Video enhancement using adaptive spatio-temporal connective filter and piecewise mapping

This paper presents a novel video enhancement system based on an adaptive spatio-temporal connective (ASTC) noise filter and an adaptive piecewise mapping function (APMF). For ill-exposed videos or those with much noise, we first introduce a novel local image statistic to identify impulse noise pixels, and then incorporate it into the classical bilateral filter to form ASTC, aiming to reduce the mixture of the most two common types of noises - Gaussian and impulse noises in spatial and temporal directions. After noise removal, we enhance the video contrast with APMF based on the statistical information of frame segmentation results. The experiment results demonstrate that, for diverse low-quality videos corrupted by mixed noise, underexposure, overexposure, or any mixture of the above, the proposed system can automatically produce satisfactory results

Theory of low frequency magnetoelectric coupling in magnetostrictive-piezoelectric bilayers

A theoretical model is presented for low-frequency magnetoelectric (ME) effects in bilayers of magnetostrictive and piezoelectric phases. A novel approach, the introduction of an interface coupling parameter k, is proposed for the consideration of actual boundary conditions at the interface. An averaging method is used to estimate effective material parameters. Expressions for ME voltage coefficients are obtained by solving elastostatic and electrostatic equations. We consider both unclamped and rigidly clamped bilayers and three different field orientations of importance: (i) longitudinal fields in which the poling field, bias field and ac fields are all parallel to each other and perpendicular to the sample plane; (ii) transverse fields for magnetic fields parallel to each other and perpendicular to electric fields, and (iii) in-plane longitudinal fields for all the fields parallel to each other and to the sample plane. The theory predicts a giant ME coupling for bilayers with cobalt ferrite (CFO), nickel ferrite (NFO), or lanthanum strontium manganite (LSMO) for the magnetostrictive phase and barium titanate (BTO) or lead zirconate titanate (PZT) for the piezoelectric phase.Comment: To be published in Physical Review B, August 1, 200

Impact bodemprognose op detailadviezen Oosterschelde

Het doel van deze studie is de invloed van de prognosebodem voor het jaar 2062 op de golfhoogte (Hs), golfperiode (Tpm) en golfbelasting (Z1) uit de bestaande detailadviezen van de Oosterschelde vast te stellen. Daarnaast is in deze studie een advies gegeven of en hoe men ook voor dijkvakken waar nog geen detailadvies is afgegeven de invloed van de bodemprognose voor het jaar 2062 kan meenemen. De opbouw van dit rapport is als volgt. Na deze inleiding van hoofdstuk 1 wordt in hoofdstuk 2 de methodiek besproken, zoals deze in de huidige studie is toegepast. Daarnaast wordt een korte gebiedsbeschrijving gegeven. Hoofdstuk 3 geeft een korte samenvatting van de herkomst van de huidige golfrandvoorwaarden die worden toegepast in de huidige detailadviezen (op basis van de ontwerpbodem). In hoofdstuk 4 wordt naast de herkomst van de ontwerpbodem en prognosebodem de interpolatie van de prognosebodem naar de rekenroosters voor de in deze studie uitgevoerde simulaties besproken. Ook worden in dit hoofdstuk de verschillen tussen de ontwerpbodem en prognosebodem kort geanalyseerd. De beschrijving van de in deze studie uitgevoerde SWAN berekeningen is te vinden in hoofdstuk 5. Hoofdstuk 6 beschrijft de bepaling van de maatgevende golfrandvoorwaarden per dijkvak en de daarbij toegepaste correcties op de SWAN resultaten. De impact van de bodemprognose staat beschreven in hoofdstuk 7. Hoofdstuk 8 geeft een advies over de toepassing van bodemschematisatie met betrekking tot de detailadviezen voor de Oosterschelde. Daarnaast wordt ook een advies gegeven over hoe de herziene golfrandvoorwaarden het beste kunnen worden verwerkt in de bestaande en de nog op te leveren detailadviezen. Tenslotte zijn de conclusies en aanbevelingen te vinden in hoofdstuk 9