It is important to measure the temperature of magnetic nanoparticles during hyperthermia therapy to develop safe practices. We theoretically demonstrate a method for measuring the temperature of magnetic nanoparticles using induction coils and nanoparticle magnetization harmonics. A geometrically decoupled sensing coil is described that enhances the sensitivity to small amounts of iron and also could possibly be used to eliminate sensing challenges created by the high-powered hyperthermia drive field.

Sol-gel coatings show an excellent chemical stability, oxidation control and enhanced corrosion resistance for metal substrates. An organic-inorganic hybrid consisting of poly (methyl methacrylate) (PMMA) and silica (SiO2) was successfully synthesized in the form of solution, by using 3-(trimethoxysilyl) propyl methacrylate (TMSPM) as a coupling agent and cohydrolyzed with tetraethyl orthosilicate (TEOS) to afford chemical bondings to the forming silica networks by a sol-gel method. The as-synthesized hybrid material was subsequently characterized by Fourier Transformation infrared (FTIR) spectroscopy. PMMA-SiO2 was applied as a protective film on hardness steel substrates by dip-coating. The thickness of the coating was 25 µm, while the roughness Ra = 0.6 µm. The wear and friction behavior of the coating on hardened steel (HS) was evaluated by a ball-on-disk test in dry conditions with a AISI steel ball as counterface applying 2, 4, 6, 8 and 10 N normal loads. Friction coefficient values (µk) were in the range of 0.76 to 0.99, whereas the lowest wear rate (k) was observed at 6N with a value of 1.30x10-4 (mm3(Nm)-1).

Recognition of material structures, particularly, identification of electrical properties of materials by Electrical Tomography is very important in different applied problems. In a plane case Electrical Tomography can be mathematically described as a coefficient inverse problem for the Laplace type equation, written in the divergent form. The General Ray (GR) Principle, proposed by the author, reduces the Laplace type equation to the family of ordinary differential equations with respect the traces of the potential function and the permittivity function on the lines, which intersect the plane domain. General Ray Principle was realized as General Ray method and fast algorithm for the plane domains. In presented investigation we apply the plane scheme of GR-method for some space domains to identify distribution of structure characteristics inside it. For this we consider the space domain as assemblage of plane slices. Reconstructing desired distribution in each plane slice we obtain then the space internal distribution of electrical characteristics by 3D spline approximation. We consider here specific variant of the measurement scheme for the 3D Electrical Tomography (ET), based on the variant, proposed by the author for the plane domain. Proposed approach gives, in principle, the possibility to use a large number of electrodes, obtain more values of the input data and reconstruct the desired space structure more perfectly. Computer simulation of this 3D scheme is realized as MATLAB software and justified by numerical experiments on simulated examples.

In this paper, the authors have reported the structural and photoluminescence (PL) studies of pure and nickel (Ni) doped zinc oxide (ZnO) nanoparticles synthesized by the solution combustion method. The structural, morphological and optical studies are carried out by powder x-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and PL spectra, respectively. The XRD pattern indicates that the prepared particles are in hexagonal wurtzite structure with the average crystalline size is around 35-50nm. Room temperature PL shows the near band edge related emission and the results are related several intrinsic defects in the ZnO nanoparticles.

The dynamics of one atom thick h-BN suspended nanoribbons have been obtained by first performing ab-initio calculations of the deformation potential energy and then solving numerically a Langevine type equation to explore their use as energy harvesting devices. Similarly to our previous proposal for a graphene-based harvester1, an applied compressive strain is used to drive the clamped-clamped nanoribbon structure into a bistable regime, where quasi-harmonic vibrations are combined with low frequency swings between the minima of a double-well potential. h-BN, graphene and MoS2 similar structures have been compared in terms of the static response to a compressive strain and of the dynamic evolution induced by an external noisy vibration. Due to its intrinsic piezoelectric response, the mechanical harvester naturally provides an electrical power that is readily available or can be stored by simply contacting the monolayer at its ends. Engineering the induced non-linearity, the proposed device is predicted to harvest an electrical root mean square (rms) power of more than 180 fW when it is excited by a noisy external force characterized by a white Gaussian frequency distribution with an intensity in the order of Frms=5pN.

Through a unique combination of magnetophoretic and photopolymerization processes, approximately 150 μm thick functionally graded films based on a UV-curable matrix and containing Fe3O4@SiO2 core-shell nanoparticles are synthesized. Owing to their continuous composition gradients and to the considerable variations in elastic modulus (up to ≈70 %) when going from particle-depleted to particle-enriched regions, such materials are highly efficient in reducing the mechanical stress arising from thermal variations, therefore improving the material efficiency towards durability and delamination problems.

In nerve and muscle regeneration applications, the incorporation of conducting elements into biocompatible materials has gained interest over the last few years, as it has been shown that electrical stimulation of some regenerating cells has a positive effect on their development. A variety of different materials, ranging from graphene to conducting polymers, have been incorporated into hydrogels and increased conductivities have been reported. However, the majority of conductivity measurements are performed in a dry state, even though material blends are designed for applications in a wet state, in vivo environment. The focus of this work is to use polypyrrole nanoparticles to increase the wet–state conductivity of alginate to produce a conducting, easily processable, cell–supporting composite material. Characterization and purification of the conducting polymer nanoparticle dispersions, as well as electrochemical measurements, have been performed to assess conductivity of the nanoparticles and hydrogel composites in the wet state, in order to determine whether filling an ionically conducting hydrogel with electrically conductive nanoparticles will enhance the conductivity. It was determined that the introduction of spherical nanoparticles into alginate gel does not increase, but rather slightly reduces conductivity of the hydrogel in the wet state.

We present calculation of electronic structure of impurity in nanowire. Ionization energy of impurities are calculated in dependence on nanowire radius. Direct Hamiltonian matrix diagonalization method with the physically reasonable approximate potential is employed for finding the exact solution of Schrödinger equation in the effective-mass approximation. It is shown that shallow donors are strongly influences by space confinement, which is expressed in sharp increase of ionization energy. Calculations show that effect of space confinement on deep impurities is less pronounced. The obtained results give hope that by selecting optimal value of nanowire radius compensation processes can be suppressed.

We report here partially stabilized zirconia (PSZ) matrix deposited with nanocrystalline diamond (NCD) films on its surface as an alternative material for pulverization disk with a potential of substituting high cost synthetic single crystal diamond. The deposition of NCD films on PSZ improved the characterization of the desorption-oxygen from PSZ matrix and enhanced the poor adhesion strength between NCD film and PSZ when N2 was used as doping gas. The results for X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy confirmed that with increasing N2 flow rate, nitrogen and desorption-oxygen were incorporated into film. The adhesion test and the pulverization test showed that enhancement in the adhesion strength as well as in the pulverization performance with increasing nitrogen and oxygen concentration in the NCD films. The results proposed to substitute a synthetic single crystal diamond with PSZ by coating nitrogen-doped NCD film.

Lithium ion batteries are becoming more important because of their high energy density and design flexibility. The capacity of these batteries is usually cathode limited; so, it follows that increasing the capacity of the cathode is essential to raise the performance of such batteries. In this work, fractal dimension study is used to understand the behavior of a Li2TiO3 made by mechanical milling, as a way to improve their uses in energy storage. Digital image analysis allows the study of fractal dimension; X-ray, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analysis were used to analyze changes on the surface of samples from the current results the distinctive characteristics of the surfaces for each sample may be obtained, making it possible to predict a future behavior of the samples. MATLAB software FRACLAB 2.03 developed by INRIA was used as a tool.

Here we report the preparation of functionalized latexes with isocyanate groups through an emulsion terpolymerization of BA/St/TMI. The emulsions were stabilized with two surfactants, EF-800 or MA-80; the TMI acted as a self crosslinked promoter during the film formation. We found a strong dependence of surfactant type in particle size and particle number. Moreover colloidal stability of latexes by a period of time was different, and the best colloidal stability was obtained with EF-800 surfactant. Swell index and mechanical properties of latex films were studied.

In-situ x-ray scattering methodology is discussed, in order to analyze the microstructure development of soft functional materials during coating, annealing, and drying processes in real-time. The relevance of a fundamental understanding of coating processes for future industrial production is pointed out.

We review recent progresses on in-situ observation of lattice relaxation of III-V lattice-mismatched system and analyses of defect properties in III-V-N solar cell materials. We found that there were five phases during the InGaAs growth on GaAs substrate. The transition point of the dominant dislocation behavior could be determined precisely. We also found that compositionally step-graded InGaAs/GaAs(001) buffers with overshooting (OS) layers were effective to control the strain of the top layer from tensile to compression. To understand the defect properties that dominate the electrical property of CBE-grown GaAsN films, we characterized deep levels in CBE-grown GaAsN films by DLTS. In this characterization, a well-known electron trap E1 (Ec-0.33eV) center in n-GaAsN and p-GaAsN was confirmed to be non-radiative recombination center by using double-carrier pulse DLTS.

We report a change in the dielectric response of AlGaInP based multi quantum well diodes with the onset of modulated light emission. Observed variation in junction capacitance and modulated light emission, with frequency and temperature, suggests participation of slow defect channels in fast radiative recombination dynamics. Our work establishes prominent connection between electrical and optical properties of light emitting diodes and provides a tool to investigate the interesting condensed matter physics of these structures. Our observations demand a generalized physical framework, beyond conventional models, to understand an active light emitting diode under charge carrier injection. We suggest that the low frequency response can compromise the performance of these diodes under high frequency applications. We also suggest how internal quantum well structure can affect modulated light output efficiency of the device.

In the present work nanostructures of manganese dioxide have been synthesized and characterized as potential catalysts for Li-air batteries. The R-MnO2 nanourchin-shaped catalyst was synthesized by mild hydrothermal conditions under autogeneous pressure. X-ray powder diffraction (XRD) was used to confirm the formation of single R-MnO2. The microstructure of the obtained nanostructures was investigated by scanning and transmission electron microscopy (SEM and TEM) showing the presence of acicular manganese oxide aggregates (5-10 nm wide) which tend to form spherical clusters, taking on an urchin-shaped form of roughly 6 microns diameter. The cyclability analyses reveal an enhanced performance and efficiency for the batteries with higher amounts of catalyst. This catalyst is thought to promote alternative reaction pathways in the Li2CO3 decomposition which attenuate the instability of the electrolyte and/or carbon electrode during the discharge resulting in an improved cyclability.