The Mossbauer spectra of nanoferrite materials such as Ni0.25Mn0.75Fe2O4, Co0.5Mn0.5Fe2O4 and Ni0.4Co0.6Fe2O4 have been reported and the above materials were prepared by sol-gel combustion method using metal nitrates as source material and Polyvinyl alcohol (PVA) as agglomeration reducing agent. As the structural, thermal and magnetic properties (VSM) of the above ferrites have been published already, hence, the present paper reports the Mossbauer studies of the nanoferrites. Based on the observed values of hyperfine parameter such as Isomer shift (IS), Quadrupole splitting (QS) and hyperfine field values, the distribution of ion and structure of the ferrites has been reported.

Background and Aims: Disc displacement is the most common temporomandibular joint disorder and magnetic resonance imaging (MRI) is the gold standard in its diagnosis. This disorder can lead to changes in signal intensity of magnetic resonance (MR). The purpose of this study was evaluation of correlation between relative signal intensity of MR images of retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle with type of anterior disk displacement and condylar head flattening in patients with temporomandibular disorder (TMD).Materials and Methods: In this retrospective study, 31 MR images of patients who had anterior disc displacement were evaluated. After relative signal intensity measurement for retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle, the correlation between relative signal intensity and type of anterior disc displacement was evaluated with repeated measure ANOVA test. In each of these 3 areas, t-test was used to compare the groups with and without condylar head flattening.Results: The correlation between relative signal intensity of MR images and type of anterior disc displacement in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle was not significant. There was also no statistically significant correlation between relative signal intensity of MR images and flattening of condylar head in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle (P>0.05).Conclusion: According to findings of this study, relative signal intensity of MR images in retrodiscal tissue, superior and inferior head of ptrygoid muscle is not a good predictor for type of anterior disc displacement and flattening of condylar head. It seems that this cannot be used as a diagnostic marker for TMD progression.

Background & Aim: The most detailed information about neural activity comes from intracellular recording. Not only this technique shows the pattern of neural action potential, but it also records the cellular events which give rise to the action potential, including variations in the resting potential, changes in cellular resistance and synaptic potentials.Results: Using this method with manipulation of the composition of the bathing solution (c.hanging ionic concentrations or adding drugs) the ionic mechanisms responsible for these potentials can be identified. It is also possible to investigate the mechanisms of actions of drugs such as dental sealers on neuronal excitability.Conclusion: In the present study, intracellular recording technique has been introduced in dental materials research as a valuable method to determine the neurotoxicity of endodontic sealers on neuronal cells.

Most electromagnetic systems work under variable magnetic fields. Fast variation of a magnetic field may cause eddy current and excess loss in ferromagnetic materials. This paper presents a simple and practical technique in field analysis of electromagnetic systems having dynamic effects (eddy current and excess loss effects). Based on existing formulations for eddy current and excess loss, an equivalent expression for field intensity has been introduced. A new technique has been presented, in order to include this expression in the finite element code. A typical system has been modeled by this code. Effects of relaxation and time step were examined on the stability and the convergence rate of the process. The validity of the proposed model has been checked by comparing its results with experimental measurements.

We have successfully prepared Fe3O4/MWCNT nanohybrid with a very simple and economical method. Multi Walled Carbon NanoTubes (MWCNT) encapsulated with Fe3O4 nanoparticles were synthesized via pyrolyzing of ferrocene. The sample was characterized with XRD, TEM and Vibrating Sample Magnetometer (VSM). Also, Permeability (μ ) and Permittivity (ε ) were measured. The reflection-loss was measured at 2-18 GHz with a HP8722ES vector network analyzer. In 2-18 GHz frequency range (microwave frequency), the dielectric loss (tan δ E=ε ″ / ε ′ with an amount between 0. 5-0. 6) effectively improves via the addition of Fe3O4/MWCNT nanohybrid in the desired composite with paraffin matrix. Therefore, it can be concluded that Fe3O4/MWCNT nanohybrid has good potential to improve microwave absorption and can be used as Radar Absorbing Material (RAM).

This work deals with the preparation of Aluminium-substituted Nickel ferrite by powder metallurgy method in different Al contents (X=0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 in NiAlxFe2-xO4). Magnetic properties of samples are measured by an LCR meter; morphology and structure of samples are characterized by SEM and XRD, respectively. The effect of Al content and grain size on effective magnetic permeability (meff), equivalent series resistance (RESR), Curie temperature (Tc) and lattice parameter have been investigated. The results show that the above parameters decrease as Al content increases.