Three-dimensional numerical simulations can provide information which cannot be obtained from experiments and can be a powerful tool for investigating reaction phenomena in solid oxide fuel cell (SOFC) electrodes. In the present study, a dual-beam focused ion beamscanning electron microscope is used to reconstruct the three dimensional microstructures of the SOFC electrodes, and their polarization characteristics are predicted by a lattice Boltzmann method. Predicted overpotentials for Ni-YSZ anode and mixed ionic and electronic conducting cathode (La0.6Sr0.4Co0.2Fe0.8O3-δ; LSCF6428) are compared with the experimental data for validation. In addition, three-dimensional distributions of electrochemical potential and current densities inside the electrode microstructures are obtained. Large non-uniformities of potential and current distributions are found in the Ni-YSZ anode, while those became much uniform in the LSCF cathode. The present method can be expected as a powerful tool for investigating local potential fields which affect local reactions and diffusion processes as well as local physical properties of the SOFC electrodes.

This paper describes the implementation of a custom-made bio-microelectromechanical system for determining mechanical properties of biological cells, which is used for the measurement of mechanical properties of fibroblasts. Our system consists of several subcomponents: (a) actuator which deforms the cell in pre-determined, step-wise fashion, (b) force sensor that measures force applied onto the cell, (c) set of dielectrophoretic (DEP) electrodes for positioning cells in the desired position, (d) temperature sensors and (e) heater. Preliminary results of the mechanical properties of NIH3T3 cells have been determined using this tool and our cell compression techniques.

Laser irradiation of Bismuth thin films through a diffractive mask was investigated. The thin films were composed of nano and microcrystals Bismuth with sizes ranging from 20 to 500 nm. Upon laser irradiation (λ=355 nm) the structured illumination field locally modified the material. In the high intensity regions the surface was transformed whilst low intensity areas were left intact. The modification mechanism was melting followed by coalescence of the nanocrystals giving rise to a more uniform structure. The laser irradiated area was characterized by scanning electron microscopy and atomic force microscopy. The patterns were computed by Fresnel diffraction theory and the agreement between the theory and the experiments was very good.

In order to increase the wettability and capillary forces of the filler metal between micro-cracking and micro-porous on the fracture surfaces of 304 stainless steels, methods of impregnation of Si and growth of Ni nanoparticles were used. These nanoparticles have a role inside the Transient Liquid Phase (TLP) and the substrate when using Brazing process. TLP can react with the nanoparticles previously deposited between micro-cracking and micro-porous and therefore promotes the nucleation and growth sites of phases and decreases the formation of eutectic structures. This method increases the effectiveness of metallic components reparation using Brazing process. Such effectiveness is indicated by an inspection of microstructural failure analysis, as a first stage, in the covered zone by the filler metal.

The influence of electrodeposition parameters on chemical composition, morphology and functional properties of such binary cobalt alloys as CoAg, CoW, and CoFe has been investigated. The alloys are shown to possess catalytic properties. Catalytic activity was preliminary estimated in the electrolytic hydrogen evolution reaction and tested by CO to CO2 conversion during the catalytic benzene oxidation.

Copper-containing nanomaterials have been developed as antimicrobial additives for food packaging applications. These nano-antimicrobials are composed of copper nanoparticles (CuNPs) embedded in poly-lactic acid (PLA), which has been selected as a biodegradable polymer matrix. Copper nanostructures have been synthesized by laser ablation following two different protocols: (I) one-pot synthesis in presence of PLA and (II) in absence of polymer matrix. In the latter route, the as prepared CuNPs suspension has been subsequently mixed to a PLA solution. The resulting dispersions have been directly drop-cast on several substrates. Nanoantimicrobials have been characterized by UV-Vis and x-ray photoelectron spectroscopies, and transmission electron microscopy. The kinetics of copper release in aqueous solution from antimicrobial nanomaterials have been studied by means of Electro-Thermal Atomic Absorption Spectroscopy. Finally, preliminary biological tests have been performed on Pseudomonas species by JIS methods (Japanese Industrial Standard, JIS Z 2801:2000).

A method is presented to map reaction diagrams for metastable phases by treating a rod-shaped sample under high pressure in a known temperature gradient, such that each point on the sample is treated at a unique, known temperature. After quenching to ambient conditions the structural properties of the sample can be studied by spectroscopic or other techniques. The accuracy and resolution in temperature is mainly limited by the uncertainties in the measured temperature distribution during treatment and the uncertainty in position during analysis. The method is tested by re-mapping the polymerization reaction of C60 under high pressure in the range 0.8 – 2 GPa. Preliminary data show surprisingly sharp "reaction boundaries" at certain temperatures, signalling the onset of dimerization and polymerization of the material.

Non thermal plasma is emerging as a novel tool for the treatment of living tissues for biological and medical purpose. In this study we described the effect of DBD (dielectric barrier discharge) plasma on both cancer and normal cell line in presence of osmolytes. Osmolytes having unique protective metabolic roles and also found in animal body, they are acting as antioxidants, providing redox balance, detoxifying sulfide, protect macromolecules, enhance protein folding and regulate cell volume. Based on these interesting properties of osmolytes, non thermal plasma in presence of osmolytes appears to provide a new outlook. Results of this study reveals that osmolytes in presence of plasma act as protecting agent for normal cells however, not to cancer cells in the presence of plasma. The main goal of this study is to protect normal cells from the toxic effect of DBD plasma.

Penetration of a nanochannel mask by 190keV Co+ ions is tested for the purpose of achieving laterally modulated ion implantation into a SiO2 thin film on a Si substrate. A 2D-nanoporous membrane of anodic aluminum oxide (AAO) is chosen as the mask. Criteria and challenges for designing the mask are presented. Implantation experiments through a mask with pore diameter of 125 nm and inter-pore distance of 260 nm are carried out. Cross-sectional TEM (XTEM) is shown as an ideal tool to assess depth distribution and lateral distribution of implanted ions at the same time, complemented by Rutherford backscattering spectroscopy. Using energy dispersive x-ray spectroscopy linescans, a Co distribution with lateral modulation is found at 120 nm below the oxide surface. First experiments in converting the atomic distribution of Co to discrete nanoparticles by in-situ TEM annealing are presented.

The nodal SDW order parameter on a cylindrical Fermi surface is thought to create the Dirac cone in the metallic ground state of iron pnictides and iron chalcogenides. Confirming appearance of the Dirac cone in DFT-GGA solutions of FeSe, we discuss origin of the bulk SDW order parameter in the stacked two-dimensional electronic system. In a layered system with vanishingly small inter-layer single-particle hopping processes, the exchange channels derived for the inter-plane magnetic interaction is the super-exchange counterpart of the two-particle Coulomb scattering for the pair-hopping channel in the layered superconductivity. The fluctuation reference method of the multi-reference density functional theory concludes existence of the inter-layer super-exchange interaction by the Coulomb off-diagonal elements among orbitals in the semi-metallic band structure. Thus a proof of 2D nature of the third generation Dirac cone in iron pnictides induced by SDW also promotes understanding of the high-temperature superconductivity.

The electrical noise characteristics of thin film random networks of single walled carbon nanotubes with lengths of 820nm, 210nm and 130nm, were evaluated in addition to mixed length and pure semiconducting single-walled carbon nanotube networks. This study represents one of the first experimental studies in which highly characterized length sorted single walled nanotubes networks have been investigated to isolate their contributions to 1/f noise. In this work we evaluate the noise power spectrum, in the low frequency range, for each of our type sorted samples and demonstrate the effect of nanotube type, length, dimensionality and critical percolation conditions in 1/f noise generating mechanisms. 1/f noise in two-dimensional (2-D) thin films of random network, homogeneous length sorted SWNTs at their percolation threshold in contrast to three dimensional (3-D) thin films of mixed length SWNT and purely semi-conducting SWNT thin films were investigated. We find that at their respective critical percolation thresholds, xc, length sorted SWNT networks exhibit atypical reduced noise amplitude (A) characteristics compared to their mixed length and semi-conducting nanotube counterparts.

Nanosized titanium dioxide (TiO2) and zinc oxide (ZnO) are widely used as inorganic sunscreen pigments. However, these metal oxide particles may also be photocatalytic and generate DNA-damaging reactive oxygen species. Therefore, we evaluated the photochemical properties of the whole sunscreen emulsions that contained nanoscale components and the inorganic particles derived from these sunscreens using several assays such as dichlorofluorescein fluorescence, the decolorization of Congo red dye and DMPO spin trap electron paramagnetic resonant spectroscopy. The results of these three tests showed that samples with ZnO nanoscale materials were more photoactive than the samples that contained TiO2 nanoparticles.

Inkjet printing is a highly material-efficient solution deposition technique that enables the preparation of thin-film libraries using little amounts of materials. As a reproducible and precise patterning technique inkjet printing can be integrated into a combinatorial screening workflow that allowed the systematic characterization of thin-film properties of newly developed materials as well as the methodical investigation of preparation parameter that influence the performance of the inkjet printed layers.

This contribution provides a demonstration of a combinatorial screening workflow that utilizes inkjet printing to evaluate structure-property relationships of polymer/fullerene blends for the application in organic photovoltaics. Using this approach it is shown that optimized blend compositions as well as printing conditions lead to improved performances of organic solar cell devices.

Finemet-type amorphous alloys are good soft magnetic materials due to their amorphous-nanocrystalline structure with close to zero magnetostriction. A very sensitive method for controlling relaxation and crystallization processes in such alloys is proposed. It consists in precise DSC measurements of heat capacity peak in the vicinity of the Curie temperature TC. Time-temperature dependencies of TC for microwires in comparison with ribbon shaped amorphous alloys were studied. Relaxation of atomic structure of amorphous phase during annealing was accompanied by an increase of TC. σ-shaped time dependencies are characterized by at least two relaxation processes, corresponding apparent values of activation energy were estimated. Decomposition of amorphous phase and redistribution of components between amorphous phase and growing nanocrystals affect the shape and position of the DSC peak at TC as well.

Study of microwires with glass coating revealed the influence of internal stress on the shape and position of the Curie peak on DSC curve: increase of internal strain tensions leads to suppression of the TC peak.

We investigate the role of precursor thermal rearrangement and surface catalytic reactions in the synthesis of vertically aligned carbon nanotubes (VA-CNTs) by acetylene-based, chemical vapor deposition (CVD) and demonstrate a millimeter-long growth of single-walled CNT (SWNT) without water assistance. A substrate heater was used to create an ascending temperature gradient from gas injection to catalyst substrate. Whereas temperature of catalyst substrates primarily determines their catalytic activity, it is a thermal condition of a gaseous mixture in the CVD chamber that also influence growth yield and structural features of as-grown CNTs. Employing Egloff’s characterization, [1] we discuss the importance of various gas thermal zones in producing high-quality nanotubes with augmented growth efficiency. We continue to report production of millimeter-long, VA-SWNT having a mean diameter of 1.7 ± 0.7 nm, catalyzed by iron on an alumina support. Important finding is that a million of aspect ratio of SWNT arrays can be produced, without water assistance, via combined action of an ascending temperature gradient toward catalyst substrate and low partial pressures of acetylene carbon feedstock. Our results do not only emphasize the role of precursor thermal rearrangement in CNT synthesis, but also offer a practical route to the modulation of such complex phenomena for an ultrahigh-yield growth of narrow VA-SWNT.

We have performed first-principles density functional theory calculations to investigate how subsurface 3d transition metals M (M = Ni, Co, Fe, Ti, or V) affect the energetics and mechanisms of oxygen reduction reaction (ORR) on the outermost Pt mono-surface layer of Pt/M (111) surfaces. We found that the alteration of the ORR mechanism pathway can explain the activity enhancement for ORR on the Pt/M (111) surfaces.

In this work, a novel star 4-arm poly(ethylene glycol-co-lactide) acrylate macromonomer (SPELA) is synthesized, and the effect of macromonomer concentration and architecture on modulus, swelling ratio and sol fraction is investigated. The results show that the storage modulus of the hydrogel had an increasing trend with polymer concentration. Changing the polymer architecture from linear to 4-arm increased the storage modulus by 2.2-fold. The water content depended on the hydrophilic segment density as well as the extent of crosslinking and showed a decreasing trend with macromonomer concentration. The sol fractions of the SPELA hydrogels changed from 13% to 5% when concentration increased from 10% to 25%. The star SPELA hydrogel with high modulus, fast gelation time, and low sol fraction is potential useful as a degradable carrier in cell-based therapies. Results show that the SPELA hydrogel supports viability and osteogenic differentiation of the encapsulated bone marrow stromal cells.

In this paper we propose a few helium ion microscope (HIM)-based methods for sample preparation and modification. In particular we report the use of the HIM to make thin wedge SrTiO3 samples without significant artifacts, the possibility to reshape thin metal lines on an electron transparent membrane and the new method of HIM sample preparation by in situ heating of the samples during He-beam illumination.

The oxidation behavior of γ-TiAl specimens coated with an intermetallic Ti-49Al-34Cr-4Zr layer was investigated at 1000°C under cyclic conditions in laboratory air. The 11 μm thick coating was produced using a combined technique of high power impulse magnetron sputtering and unbalanced magnetron sputtering. The as-deposited coating exhibited a dense layered structure and excellent adhesion to the substrate. The Ti-Al-Cr-Zr coating possessed high oxidation resistance associated with the formation of a thin continuous alumina scale for exposure time periods exceeding 1000 cycles of 1 h dwell time at 1000°C. During the high temperature exposure, the coating being amorphous in the as-deposited condition became crystalline exhibiting different polytypes of Ti(Cr,Al)2Laves phases with Ti probably partially substituted by Zr and Nb. Due to alumina formation and interdiffusion the coating was depleted in aluminum and chromium as well as enriched in titanium. After 1000 cycles at 1000°C, the coating consisted of an outer layer of the hexagonal C14 Laves phase and an inner layer of a probably orthorhombic phase whose structure was not yet determined. In both layers, pores and fine precipitates rich in Zr and Y were found.

In this work, the first-principles computational scheme of electron-ion dynamics based on the time-dependent density functional theory is presented as a tool to study dynamical phenomena induced by light. Two applications of computations for photo-induced phenomena are shown. The one is structural change induced by intense and short laser shot with a purpose to simulate experiments using the femtosecond laser. The other is photo-excitation and subsequent carrier splitting into electrons and holes, which is a key process needed in photovoltaic materials.