We report on the structural and electrical characteristics of bulk and thin film of ternary oxide SmGdO3. Bulk sample of SmGdO3 was prepared by pelletizing and sintering the calcined mixture of predetermined amount of Sm2O3 and Gd2O3 powders. The crystalline structure of the sample was studied by X-ray diffraction measurements and Raman spectroscopy. Capacitance and leakage current measurements on bulk sample revealed a high and linear dielectric constant of ∼ 19 with low dielectric loss and leakage current which is suitable for gate dielectric application in CMOS logic devices and high-k MIM capacitors. In addition, the non-volatile resistive memory switching phenomenon was studied in thin films of SmGdO3 which were deposited by pulsed laser deposition using sintered pellet of SmGdO3 as target. Commercially available Pt/TiO2/SiO2/(100) Si was used as substrate and top Pt electrode of lateral dimension 40×40μm2 were deposited by sputtering to construct Pt/SmGdO3/Pt MIM devices. After initial forming process which occurred at comparatively higher voltage, the Pt/SmGdO3/Pt devices showed repeatable unipolar switching between high and low resistance states with low and well defined switching voltages. These properties indicate suitability of this material for the emerging logic and memory device applications.

Fe-Al alloys with about 55 to 65 at.% Al undergo a eutectoid transformation at 1095 °C: Fe5Al8 (ε) ↔ FeAl + FeAl2. Hence, as-cast Fe-Al alloys in this composition range show a very fine-scaled lamellar microstructure (average lamellar spacing below 500 nm) consisting of the two phases FeAl and FeAl2. The microstructure looks similar to the α2 + γ lamellar microstructure of Ti-Al-based alloys, which is known for having well-balanced properties in terms of creep, ductility and strength. However, there is limited knowledge about the properties of Fe-Al-based alloys in this composition range. In this study, a series of as-cast as well as heat-treated Fe-Al alloys with compositions between 57 and 63 at.% Al were investigated. The microstructures and crystal structures were analysed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The composition dependence of all transition temperatures was obtained by differential thermal analysis (DTA).

We demonstrated nanostructured, ITO-free anodes in flexible OLEDs using a combination of a composite organic-inorganic UV nanoimprint resist and a conductive, transparent polymer layer. Flexible OLEDs with grating anodes were fabricated on polycarbonate substrates. The nanoimprint resist was blended with 30% TiO2 nanoparticles in order to achieve a sufficient refractive index contrast to the polymer anode. It was periodically structured with a 370-nm period linear photonic crystal structure. PEDOT:PSS was spin-coated on as a polymer anode and structured in an oxygen plasma treatment. For OLED demonstration an organic emission layer (PPV-derivative “Super Yellow”) and a metal cathode (LiF/Al) were deposited. We observed successful waveguide mode extraction both in electroluminescence and photoluminescence for flat and bend substrates. The waveguide mode extraction angle varied slightly under bending. The combination of an inorganic-organic composite material with a conductive polymer transparent electrode is promising for improving the performance of ITO-free, flexible OLEDs.

Copper nanoparticles are synthesized successfully through chemical reduction of different copper salts stabilized by Ocimum Sanctum Leaf extract, a natural biopolymer. The resulting copper nanoparticles are characterized by using UV Visible Absorption Spectrometer, X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Small Angle X-ray Scattering (SAXS) and Fourier Transform Infrared Spectroscopy (FTIR) experiments. Copper nanoparticles prepared display an absorption peak at around 558 nm. X-ray diffraction analysis shows that the particles are FCC crystalline. SEM and TEM display the formation of copper nanoparticles with an average size of 10 nm. The SAXS studies demonstrate the formation of spherical nanoparticles with bimodal size distribution. The FTIR spectrum analysis has confirmed the presence of functional groups of stabilizer Ocimum Sanctum leaf extract in capping the copper nanoparticles.

The Maya archaeological site of Ek’Balam is located in Yucatán, Mexico. This place is known for its artistic tradition of reliefs modeled in stucco as well as the rich pictorial and hieroglyphic texts. Although the mural played a key role in the artistic program architectural of elite groups, most of these remains have not been studied, either by its incomplete or fragile condition, or by localization in inaccessible substructures.

In this study, technical aspects of the mural paintings from rooms 12 and 50 of the main building of the site are addressed by the spectroscopic analysis of its materials. Optical microscopy was used to observe the layers superposition and pigment distribution, while the stucco and rock support were characterized by X-ray Diffraction (XRD) and X-ray Fluorescence (XRF). Moreover, the chromatic palette composed of different colors and tones of red, yellow, orange, green, blue and black were analyzed mainly with non-invasive techniques using Raman and FTIR spectroscopies as well as XRF.

The information obtained from the combination of these analytical techniques, allowed a better understanding of the similarities and differences between these two rooms that were built during the last construction stage of the Acropolis. These results were also compared with previous analyses of mural painting of this site and other Maya paintings.

In many tropical countries coconut (coir) fiber production is a major source of income for rural communities. The Caribbean has an abundance of coconuts but research into utilizing its by-products is limited. Environmentally friendly coir fibers are natural polymers generally discarded as waste material in this region. Research has shown that coir fiber from other parts of the world has successfully been recycled. This paper therefore investigates the mechanical properties of Caribbean coir fiber for potential applications in civil engineering.

Approximately four hundred fibers were randomly taken from a coir fiber stack and subjected to retting in both distilled and saline water media. The mechanical properties of both the retted and unretted coir fibers were evaluated at weekly increments for a period of 3 months. Tensile strength test, x-ray diffraction analysis and scanning electron micrographs were used to assess trends and relationships between fiber gauge lengths, diameter, tensile strength and Young’s modulus. Diameters ranged between 0.11 mm-0.46 mm, while fiber samples were no longer than 250 mm in length. The tensile strength and strain at break decreased as the gauge length increased for both unretted and retted fibers. The opposite occurred for the relationship between the gauge length and Young’s modulus. Additionally, the tensile strength and modulus decreased as the fiber diameter increased. Neither distilled nor saline water improved the coir fiber’s crystalline index. Scanning electron micrographs qualitatively assessed fiber surfaces and captured necking and microfibril degradation at the fractured ends.

The analysis revealed that the tensile strength, modulus, strain at break and crystallinity properties of the Caribbean coir fibers were comparable to commercially available coir fiber which are currently being used in many building applications.

Due to the high surface area and good bio-compatibility of nano structured ZnO, it finds good utility in biosensor applications. In this work we have fabricated highly dense ZnO nano bundles with the assistance of self assembled poly methylsilisesquoxane (PMSSQ) matrix which has been realized in a carpet like configuration with implanted ZnO nano-seeds. Such high aspect ratio structures (∼50) with carpet like layout have been realized for the first time using solution chemistry. Nanoparticles of PMMSQ are mixed with a nano-assembler Poly-propylene glycol (PPG) and Zinc Oxide nanoseeds (5-15 nm). The PPG acts by assembling the PMSSQ nanoparticles and evaporates from this film thus creating the highly porous nano-assembly of PMMSQ nanoparticles with implanted Zinc Oxide seeds. Nano-wire bundles with a high overall surface roughness are grown over this template by a daylong incubation of an aqueous solution of hexamethylene tetra amine and Zinc nitrate. Characterization of the fabricated structures has been extensively performed using FESEM, EDAX, and XRD. We envision these films to have potential of highly dense immobilization platforms for antibodies in immunosensors. The principle advantage in our case is a high aspect ratio of the nano-bundles and a high level of roughness in overall surface topology of the carpet outgrowing the zinc-oxide nanowire bundles. Antibody immobilization has been performed by modifying the surface with protein-G followed by Goat anti salmonella antibody. Antibody activity has been characterized by using 3D profiler, Bio-Rad Protein assay and UV-Visible spectrophotometer.

Gallium nitride (n-type) films of thickness 300nm were grown on c-plane sapphire substrates using plasma assisted molecular beam epitaxy (PA-MBE). High resolution X-ray diffraction and photoluminescence measurements were used to confirm the crystalline and optical qualities of the grown films. Metal-semiconductor Schottky diodes were fabricated using Pt as the Schottky metal and Al as the Ohmic metal contact. Metal-insulator-semiconductor Schottky diodes were also fabricated using HfO2 (10nm) as the insulator material. Diode parameters like barrier height and ideality factor were extracted from I-V measurements. Introduction of HfO2 as the insulator layer leads to better rectifying behavior (forward to reverse current ratio improves from 5.1 to 8.9) with a reduction in reverse leakage current (by 7.4 times), increase in barrier height (from 0.62eV to 0.74eV) and a reduction in ideality factor (from 6 to 4.1) of the Schottky diode.

In the autumn of 2012, the Japan Atomic Energy Agency (JAEA) launched a new research project named F-TRACE (Long-Term Assessment of Transport of Radioactive Contaminant in the Environment of Fukushima). The aims of this project are to develop a system for prediction of radiation exposure, taking into consideration the transport, deposition, and remobilization behavior of radiocaesium (RCs) from the highest contaminated mountain forests, down through the biosphere, before deposition in a number of different aquatic systems. Especially, it is important to understand balances of suspended and deposited particles and RCs inventory in inflow water, discharge water and bottom sediments of an upland reservoir. In this paper, we describe current research activities performed by JAEA at the Ogi Reservoir, Fukushima prefecture, Japan.

According to our analyses the specific sediment yield and the average rate of storage capacity loss at the Ogi Reservoir are 210 m3 km-2 year-1 and 0.15 % year-1, respectively. The vertical distribution of RCs exhibits clear peaks at several sites in the reservoir formed by deposition of eroded soil particles from the catchment that were contaminated by accident fallout. Above the depth of each of the RCs peaks, the distribution of RCs was found to be variable with depth, with concentrations ranging over five orders of magnitude for a single core. The peaks in the sedimentation profiles are probably formed from eroded soil particles entering the reservoir from the surrounding contaminated watershed (most probably during storm events). Results from grain size analyses suggest that contaminated fine sediment tends to be deposited thickly within deeper parts of the reservoir. In addition, above the depth of RCs peaks at these deeper sites, the concentration of RCs approximately increased or decreased as the proportion of fine sediments increased or decreased. However, some fine particles are possibly discharged downstream during operational releases from the dam.

We report a stable CdS/Sb2S3/SnSe heterojunction thin film solar cell deposited on SnO2:F (FTO) – coated glass substrates. Thermal evaporation at 10-5 Torr with substrate temperature of 400 °C was used to deposit Sb2S3 and SnSe thin films of 450 nm and 160 nm, respectively. Thin film Sb2S3 has an optical band gap (E g ) of 1.48 eV and photoconductivity (σ p ) of 4x10-7 Ω-1 cm-1 and thin film SnSe has an E g of 1.28 eV and σ p of 2 Ω-1 cm-1. The chemically deposited CdS thin film heated at 400 °C shows an E g of 2.34 eV and σ p of 0.1 Ω-1 cm-1. Stabilized solar cell structures with these thin films, FTO/CdS/Sb2S3/SnSe/C-Ag, showed open circuit voltage (V oc ) of 0.60 V, short circuit current density (J sc ) of 5.51 mA/cm2 and power conversion efficiency (η) of 0.96% with a fill factor FF of 0.29. In the absence of the SnSe layer, J sc decreases to 4.77 mA/cm2.

Agave fibers were used to elaborate a transparent and flexible cellulose hydrogel films used as scaffold for tissue regeneration and tested by in vitro assays with NIH 3T3 fibroblast cells. Using dimethylacetamide/lithium chloride (DMAc/LiCl) system was possible to obtain cellulose solutions and hydrogel films were prepared by phase inverse method without cross-linker. The concentration of LiCl in the DMAc solution was varied from 4 to 12 wt% in the phase inversion process and then the cytotoxicity was tested for 14 days on the cultivation. The resultant hydrogel films showed better cytocompatibility than the PS dish used as control. The cell growing images showed that the hydrogel films with lower LiCl apparently contained ordered and aggregated fiber orientation. This comparison suggested that the segmental microstructure in the hydrogel films influenced fibroblast cells spreading. In addition, the agave hydrogel films displayed good stability without biodegradiation through the cell cultivation.

We investigated theoretically the transmission spectra in one-dimensional photonic quasicrystals (1DPQ) made up from dielectric materials organized in accordance to a discrete varying electric permittivity profile that obeys an analogous of the quasiperiodic potential in the so-called Audry-André (AA) model, in order to modulate the refraction index. Our results show that due to the incommensurate dielectric distribution, the spectrum splits into a fractal set of pass- and forbidden-band structure. By studying the transmission spectra as a function of the modulation phase ϕ, we found boundary states lying within the gaps localized either on the left or on the right boundary of the system, characterizing the so-called topological states.

A generic model of bulk crystal plasticity with stochastic evolution of the local microstructure is formulated. The evolution of local fluctuations of internal stress and plastic strain, as well as the cross correlation between these variables, is investigated for different loading modes (stress control vs. displacement control) as a function of the coarse graining scale, and the spatial structure of the respective correlation functions is determined. The investigations demonstrate that, after an initial transient characterized by uncorrelated initiation of plasticity in different sample locations, nontrivial long range correlations emerge both within the strain pattern and between the internal stress and plastic strain patterns. The internal stresses, on the other hand, remain short range correlated throughout. Implications of our findings for larger-scale plasticity models are discussed.

Multiferroic BFO/SRO/Si trilayers have been prepared by pulsed laser deposition in the form of thin films. As a function of the BFO layer thickness, magnetic and magneto-transport properties have been investigated at room temperature and down to 5 K. At low BFO layer thickness, a residual γ-Fe2O3 phase, which interacts interfacially with the SRO and BFO layers, is responsible for moderately hard magnetic properties of the film. On increasing BFO layer thickness, more homogeneous deposits are obtained with uniform magnetic and magneto-resistive properties.

In this work, electrochemically recyclable lithium is analyzed as high energy density, large scale storage material for stranded renewable energy in a closed loop. The strongly exothermic reaction of lithium with carbon dioxide (CO2) yields thermal energy directly comparable to the combustion of coal or methane in an oxygen containing atmosphere. The thermal level of the reaction is sufficient for re-electrification in a thermal power plant compatible process.

The reaction of single lithium particles, avoiding particle-particle interactions, is compared to the combustion of atomized lithium spray in a CO2 containing atmosphere. Particle temperatures of up to 4000K were found for the reaction of single lithium particles in a CO2, nitrogen (N2), oxygen (O2) and steam gas mixture. Furthermore the combustion of atomized lithium spray in both dry CO2 atmosphere and CO2/steam gas mixture was analyzed. The identified solid reaction products are lithium carbonate, lithium oxide and lithium hydroxide. The formation of carbon monoxide (CO) as gaseous reaction product is demonstrated. Carbon monoxide is a valuable by-product, which could be converted to methanol or gasoline using hydrogen.

Alternate aluminum and arsenic precursors were investigated for InAlAs grown by organometallic vapor phase epitaxy (OMVPE). The quality of the InAlAs growths was investigated by secondary-ion mass spectrometry (SIMS) to measure impurity concentrations. Trends are extracted from SIMS measurements for each precursor as a function of V/III ratio and growth temperature. Two arsenic precursors, arsine and tertiarybutylarsine (TBAs), were chosen to compare InAlAs growth quality. The impurity concentrations measured by SIMS decrease as the V/III ratio increases, for both arsine and TBAs growths. Impurities also decrease as growth temperature increases. Two aluminum precursors, trimethylaluminum (TMAl) and tritertiarybutylaluminum (TTBAl), were used to compare the effect of alumimum precursor on carbon and oxygen impurity levels. TMAl is widely studied in literature, though TTBAl is less common. This study represents the first report using the TTBAl precursor for InAlAs growth. Each aluminum source is used in conjunction with each aforementioned arsenic precursor in order to compare all possible precursor combinations. TMAl growths demonstrated decreasing impurities with increasing V/III ratio. TTBAl growths did not exhibit such a dependence, impurity concentrations remained virtually constant regardless of V/III ratio.

Advanced electrochemical technique was elaborated to fabricate self-organized CdSe nanowire structures from aqueous electrolytes on ITO coated glass substrates. We have recently been demonstrated successful electrochemical formation of free-assistent CdSe nanowire structures with diameter around 30 nm. This work has extended our previous research of electrodeposition of Cd chalcogenide (CdSe, CdS) nanowires to formation of core-shell CdSe/CdTe photosensitive nanowire structures. CdSe nanowire structures were synthesized potentiostatically from an acidic solution of H2SeO3 and CdCl2 at room temperature. Then the CdSe (core) nanowires were further passivated with CdTe (shell) thin film by method of electrochemical deposition from acidic solution of H2TeO3 and CdCl2. The effect of interfacial passivation with CdTe layer on the performance of the prepared photovoltaic structures was investigated and special account was paid to the morphology, composition and photovoltaic properties of obtained CdSe/CdTe nano-layers. It should be noted, that electrically conductive polymer photoabsorbers (poly (3-octylthiophene) etc.) were applied successfully for preparation of high work-function ohmic contact-sensitizer layer to CdTe shells. The electrodeposition and spin-casting techniques were applied step-by-step to prepare complete hybrid photovoltaic structures.

This study used Langmuir-Schaefer (LS) method to produce thermo-responsive poly(N-isopropylacrylamide) (PIPAAm) modified surface. Block copolymer composed of polystyrene (PSt) and PIPAAm was synthesized by RAFT polymerization. PSt-block-PIPAAm (St-IP) with various chemical compositions was dropped on an air-water interface and formed Langmuir film by compression. Then, the Langmuir film changing a density was transferred on a hydrophobic modified glass substrate to produce St-IP transferred surface (St-IP LS surface). From the observation of atomic force microscope images, a nanostructure was observed on the transference of Langmuir films. Cell adhesion and detachment were also evaluated on the LS surfaces in response to temperature. Cell adhesion on LS surfaces at 37 °C was controlled by changing the chemical compositions and densities. After reducing temperature to 20 °C, adhering cells rapidly detached themselves with lower Am and higher composition of PIPAAm. Our method should be proved novel insights for investigating cell adhesion and detachment on thermo-responsive surfaces.

We have developed a “Relative Rates Method” to make bounding calculations regarding radionuclide migration due to uplift/erosion (“exhumation”) of a HLW repository. Results show that this method can apply to a wide range of different uplift rates and erosion rates. In addition, for the long time period, it was shown that the relative difference of uplift rate / erosion rate and potential hydraulic change arising from extreme uplift/erosion could affect radionuclide release and migration, thus uplift/erosion concerns should be fed back to site selection. Our method provides a credible and defensible basis for analysis and interpretation of possible uplift/erosion impacts for future volunteer sites.

Position-controlled InP nanowires (NWs) with separations of 10-100 μm were grown by the vapor-liquid-solid (VLS) method using Au-deposited SiO2-mask-patterned InP substrates. Excess indium species diffused from the large mask region formed plural tilted NW-like structures from single openings in addition to the vertical VLS NWs formed by Au catalyst. The introduction of HCl gas during the NW growth was found to efficiently suppress the tilted NW-like structures. Vertical InP NWs without anomalous growth were successfully formed by controlling the HCl flow rate. Moreover, single InP/InAsP/InP quantum wells (QWs) with wurtzite crystal phase structure were epitaxially grown on the sidewall of the position-controlled InP NWs, and two-dimensional arrayed patterns of photoluminescence (PL) coming from the radial QWs were clearly observed in the 1.3-μm wavelength region at room temperature.