The sol-gel method was carried out to synthesize nanosized Yttrium Iron Garnet (YIG). The nanomaterials with ferrite structure were heat-treated at different temperatures from 500 to 1000 °C. The phase identification, morphology and functional groups of the prepared samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. The YIG ferrite nanopowder was composited with polyvinylidene fluoride (PVDF) by a solution casting method. The magnitudes of reflection and transmission coefficients of PVDF/YIG containing 6, 10 and 13% YIG, respectively, were measured using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in X-band frequencies. The results indicate that the presence of YIG in polymer composites causes an increase in reflection coefficient and decrease in transmission coefficient of the polymer.

Improvement of measured gel content, hardness, tensile strength and elongation at break of Ethylene vinyl acetate (EVA) have confirmed positive effect of electron beam irradiation on EVA.Results obtained from both gel content tests show that degree of crosslinking in amorphous regions is dependent on dose. A significant improvement in tensile strength of neat EVA samples is obtained upon electron-beam radiation up to 210 kGy. Similarly, hardness properties of Low-density polyethylene (LDPE) improvewith increasing electron beam irradiation. This article deals with the impacts of electron beam (EB) irradiation on the properties of LDPE and Ethylene-Vinyl Acetate (EVA) as the two common based formulations for wire and cable applications.

The domain wall motion in magnetic nanoparticles is a useful parameter of study. The subject of this research is to study of the phenomenon of discontinuous domain wall motion, or the Barkhausen Effect in magnetic nanoparticles. In this work hematite (Fe2O3) nanoparticles have been synthesized using sol-gel auto-combustion and characterized using X-ray diffraction, Field emission scanning electron microscopy (FESEM), Transmission electron microscope (TEM) and Vibrating sample magnetometer (VSM) for crystal structure, morphology, shape, size and magnetic properties respectively. The FESEM and TEM results show that the particles are spherical in nature and average size is 60nm that is suitable for domain walls and barkhuasen effect. The VSM results show high coercivity 175 Oe and low saturation magnetization due to domain wall pinning and barkhausen effect. The size and magnetic properties reveals the existence of domain walls in the synthesized sample. The magnetic properties confirm the energy losses due to domain wall pinning, discontinuous domain rotation or barkhausen effect during magnetization which is useful for oil-water interfacial tension reduction and viscosity of oil. The high surface charge of magnetic nanoparticles and adsorption at the rock surface is useful for wettability alteration of rocks.

Chemical substitution is one of the methods to modify magnetic and structural properties of magnetic materials. Substitution of cobalt ions in magnetite lattice has been done via co-precipitation method to investigate the effect of cobalt substitution in altering the structural and magnetic properties of Co(x)Fe(1-x)Fe2O4. Changes in the lattice constant have been observed with increase in cobalt concentration though particle size varied insignificantly. Qualitative study of the cation occupancy at tetrahedral and octahedral sites was observed at wavenumbers ranging from 600 to 400 cm-1, known as the characteristic range for ferrites. Preferential occupancy of cobalt ions into tetrahedral sites was evident by the changes in the intensity of transmitted FTIR signal as the wavenumbers shifted towards longer wavenumber with increasing cobalt concentration. Meanwhile for saturation magnetization, only small changes is observed when Fe2+ is completely substituted by Co2+. Increment of 21.3% in the saturation magnetization of 1.0Co was achieved in comparison with pure magnetite, therefore proves the role of cation substitution in the enhancement of saturation magnetization.

Magnetic fluid is proposed as a substitute for the application of polymer solution as a means to recover the residual oil left in the bypassed region in oil reservoirs. When subjected to magnetic field, the viscosity of magnetic fluids increases and enable flow control. In this study, the response of magnetic nanofluid with the applied magnetic field was observed as a function of shear rate. Two types of samples, namely magnetite and cobalt ferrite of 0.1% w/v of different polydispersity index, saturation magnetization and mean hydrodynamic particle size were used. The strength of the applied magnetic field was also varied to investigate the effect of magnetic field strength on the viscosity enhancement of magnetic fluid. Shear dependence response of the magnetic fluid exhibit non-Newtonian behavior when magnetic field of 20 to 40 mT was applied. Viscosity of the magnetic fluid reduced with increasing shear rates, showing shear thinning behavior. At a particular shear rate, viscosity remains constant when the strength of magnetic field increases indicating saturation in chain length even at low field. Magnetoviscous effect (MVE) is calculated as an indicator for a viscosity gain magnitude when magnetic field is applied. Cobalt ferrite sample shows larger MVE compared to magnetite that may be attributed to the higher polydispersity index. In conclusion, particle size distribution is the most dominant factor affecting MVE of the dilute magnetic fluid when magnetic field is applied.

Seabed Logging (SBL), is a recently used application of Controlled Source Electromagnetic (CSEM) method based on study on resistivity of layers beneath seafloor, to delineate marine hydrocarbon reservoir. In this method, an ultra-low frequency electromagnetic (EM) wave is emitted by an electric straight dipole which moves parallel to the seabed. Following Maxwell’s equations, reflected and refracted waves from different layers are recorded by receiver line which is laying on the sea floor to define the contrast between amplitude and phase of responding waves of bearing oil reservoir and surrounding host rocks. The main concern of the current work is to study behavior of airwave, which is propagated wave in the seawater area, guided by sea surface and refracted back to the receiver line, and its impact on tangential and normal components of received electric field amplitude. Will be reported that the most significant part of tangential component is airwave, while it does not affect normal component of received electric field, remarkably.