We investigate the electronic structure of interstitial Li and Li vacancy in Li10GeP2S12 by first principles calculations. We find that the Li vacancy and interstitial Li+ ion do not introduce states in the band gap hence they do not deteriorate the electronic properties of Li10GeP2S12. The energy barrier for Li interstitial diffusion in Li10GeP2S12 is estimated to be 1.4 eV, which is much larger than that of the Li vacancy in Li10GeP2S12. This fact suggests that the ion conductivity arises from the migration of Li vacancy.

In this work, we report the results of solid state structural study of a series of oligothiophenes and ethylenedioxythiophenes (EDOT) endowed with bromine atoms at different positions and in the presence/absence of the strong electron acceptor, the tricyanovinyl group (TCV). Five new compounds were synthesized, crystallized and their single crystal structures were determined by X-ray diffraction. The impact of bromine atom(s) on solid state packing as viewed through analysis of intermolecular interactions is presented. Comparative study using experimental, computed and published data of closely related structures shows intra-molecular interactions involving Br in the presence of TCV and EDOT. Distances shorter that the summation of the Van der Waals radii were observed which indicate the role of Br…NC, S…S and Br…Br interactions in addition to pi stack formation and planarity of these compounds due to the presence of strong electron acceptors. Possible implications of how these structural features may impact charge transport in oligothiophenes will be discussed.

Balanced mechanical properties are needed for TiAl low pressure turbine blades envisaged for use in new generation aircraft engines. However, thermomechanical processing of γ-TiAl based alloys is a challenging task due to a small “processing window”. Isothermal forging, as state of the art process for this class of material, results in high productions costs and lower productivity. Due to these facts Bohler Schmiedetechnik GmbH & Co KG has developed a higher efficient “near conventional” thermomechanical processing technology. Lower die temperature and processing at standard atmosphere as well as the use of standard hydraulic presses with higher ram speed result in a highly economical process. Subsequent heat treatment strategies can be used to tailor microstructure and, therefore, mechanical properties according to customer needs. The paper summarizes our effort to establish a near conventional forging route for the fabrication of TiAl components for aerospace industry.

This paper discuss the presence of powdered glass and quartz integrated in the red lake layers of two paintings attributed to the Sevillian painter Bartolome Esteban Murillo that belongs to the Guadalajara’s Regional Museum’s art collection. A laboratory experimental reproduction of the Sevillian painting technique was made using three different lakes (cochineal, madder lake and brazilwood) mixed with four varieties of glass to explore the optical properties and the influence of the transparent and translucent aggregates into the oil paint layers. The experimental reproductions were analyzed using ultraviolet-visible spectroscopy, optical and fluorescence microscopy and scanning electron microscopy (SEM-EDX). A comparison between the originals and the reproduced red lakes layers was carried out to understand the artistic process of Murillo’s color application. Preliminary results suggest that glass was not used as a siccative agent as the historical treatises mentioned but mainly as an additive to increase brightness, thickness and color saturation of the red lake layers related to the artist’s intention.

A novel microwave-assisted synthesis technique was used for the rapid preparation of nanocrystalline ZnGa2O4 at two different temperatures. The crystalline spinel oxide is formed at temperatures as low as 100 o C within few minutes, at a high yield of 96%, requiring no post-synthesis annealing. The as-prepared samples are polycrystalline and phase-pure as verified by XRD, with a crystallite size of ∼5 nm. Polycrystalline ZnGa2O4 substituted with Mn2+, Cr3+, Cu2+, and Co2+ was also similarly prepared. All samples are highly monodispersed, as measured by TEM. The ZnGa2O4 nanocrystals without further surface modification can be readily dispersed in chloroform to form a fully transparent colloidal solution, using which the bandgap of ZnGa2O4 was determined to be ~4.5 eV. The entire synthesis procedure, including solution preparation, microwave irradiation, and centrifugation takes about 30 minutes, which is faster than any procedure reported for a complex oxide like ZnGa2O4, as well as one with a small thermal budget. Photoluminescence shows a broad emission extending from 330 nm to 800 nm, which is surmised to be due to the defect structure in the oxide produced.

Xaltocan used to be an island located North of the Basin of Mexico in the bed of the lake of the same name, the occupation of which has been continuous for 1100 years. The area’s environment includes the island, the lake and the shore Xaltocan saline land and deep alluvial soil, the foothills and mountains, areas that provide different resources, whose exploitation is clear from the Paleoethnobotanical remains recovered from archaeological excavations.

Maize, basic resource in the daily life of Xaltocan, was also affected by sociopolitical and economic circumstances, so, it is possible that a different type of maize was used in each period of the locality. This is the interesting point to characterize morphometrically the maize from a context housing for the early Postclassic. To do so requires the application of different techniques (methodical process) to get to the characterization of corn: sample, flotation, separation and identification, measurement of corn through a microscope that could be complemented with electron microscopy scanning (SEM) to reveal possible microstructure.

In the measurement technique applied to the samples, the cob is divided into different sections; all of them can be measured, element by element, with a stereoscopic microscope for subsequent statistical analysis.

The study includes 231 sediment samples, distributed in 19 different depths and areas inside and outside of two dwelling domestic units. From 31,230 macrorremains, 6,140 were identified as Zea mays.

Chemical Mechanical Planarization (CMP) is widely used to ensure planarity of metal and dielectric surfaces to enable photolithography and hence multilevel metallization in microelectronics manufacturing. The aim of this study is to establish a fundamental understanding on the dynamic growth of nano-scale protective oxide thin films during CMP to enable the selection of proper oxidizer concentrations for slurry formulations. Tungsten was selected as the model metal film to study the formation of these metal oxide films in various oxidizers and Atomic Force Microscope (AFM) was used to measure the surface roughness of the samples conditioned in the oxidizer environment before and after the CMP was conducted. The affect of surface roughness on wettability of the surfaces were also studied through contact angle measurements on the treated tungsten films. Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance FTIR/ATR technique in combination with the X-Ray Reflectivity (XRR) were utilized to determine the thicknesses of the oxidized nano films on the tungsten surface. The results were evaluated through the material removal responses reported in the literature for the W-CMP in addition to the comparison of the Pilling-Bedworth ratios of the oxidized nano films to determine the ability of the created oxide film as a self-protective oxide.

When a biomaterial is implanted into the body, blood proteins adsorb on itssurface and subsequently cells adhere via the protein adlayer. Thus, theunderstanding of protein adsorption and conformational change on thebiomaterial surfaces is of great importance to control the biocompatibilitysuch as antithrombotic properties and cell adhesion behaviors. In thisstudy, we synthesized hydroxyapatite (HAp) and carbonate apatite (CAp) by awet method. Then we successfully fabricated the HAp and CAp sensors forQCM-R by an electrophoretic deposition method. Adsorption behavior ofproteins on the bone substitute material can be monitored by using theseapatite sensors. Bovine serum albumin and fibrinogen were employed for themodel proteins, and monitored the adsorption behavior on the HAp, CAp andreference gold (Au) sensors by the QCM-R technique. As a result, we revealedthat fibrinogen and bovine serum albumin adsorbs on the gold surface byhydrophobic interaction, and adsorbs on the HAp and CAp surfaces mainly byelectrostatic force. Besides, we revealed that fibrinogen adsorbs on the Ausurface more rigid than on the HAp and CAp surfaces while bovine serumalbumin adsorbs on the HAp and CAp surface more rigidly than on the Ausurface.

In this research the thermal and mechanical properties of composites based on recycled high-density polyethylene (HDPE) and recycled Tetrapak have been investigated. The matrix and filler are recovered from landfills. Multicolor HDPE mixtures, with varying concentration of tetrapack flakes, are hot pressed, as well as single color HDPE flakes. Previous studies determine that the nature of the pigment (organics vs. inorganics) strongly influence the mechanical behavior of multicolor HDPE-tetrapack composites. Thus, this research focuses on single color HDPE hot pressed plaques. The kinetics of crystallization under isothermal conditions is determined by differential scanning calorimetry (DSC). The results show that the crystallization kinetics obeys the Avrami theory, and that the Avrami exponent is 1, irrespective of the pigment in use. Small-angle light scattering is applied to investigate the internal structure of the pigmented HDPE. SALS patterns show that the samples exhibited oriented morphologies. However, after melting and slow cooling under pressure the samples exhibit an isotropic morphology. This is confirmed by polarized optical microscopy. Mechanical properties such as Young’s modulus, yield stress and ultimate tensile stress are obtained under uniaxial tensile deformation at room temperature. For the single color HDPE plaques the Young’s modulus is reduced (after melting), suggesting that the anisotropic molecular chains contribute to the higher value of Young’s modulus.

We present a femtosecond pump-probe ellipsometer operating over a spectral range of 1.4 – 1.7 eV with a ∼50fs time resolution. The calibration and preliminary findings of the setup are discussed. We tested the apparatus on bulk crystalline silicon (not shown here) and on silicon nanocrystals embedded in an amorphous silicon phase. The ellipsometric angles (ψ, Δ) were determined as a function of time and wavelength. The results suggest that a simple Drude model of free carrier absorption is not sufficient to explain the findings.

In this work, the synthesis of new hybrid material based on a poly (buthyl acrylate –co- vinyl formamide) copolymer using the emulsion polymerization and doped with Pd, is discussed. The copolymer structure was confirmed by FT-IR. Afterwards, Pd nanocrystals previously synthesized, resulting on a spherical shape of ~ 5 nm, as measured by High-resolution transmission electron microscopy (HR-TEM), were deposited on the structure of the organic material. The films were analyzed using AFM and Scanning electron microscopy (SEM), giving rise to a hybrid material that could be applied in areas such as nanolithography, catalysis, and sensors.

Highly sensitive electrolyte-insulator-semiconductor (EIS) sensors were realized by the integration of Si nanowires (NWs), which were fabricated by using a simple and economic electroless wet etching technique. EIS sensors with NWs longer than 1 μm were observed to have considerably increased capacitance and high pH sensitivity. The pH sensitivity of the EIS sensor with 3.8 μm long NWs was 60.2 mV/pH, which is higher than the theoretical Nernstian of 59 mV/pH. The EIS sensors with NWs exhibited slightly worse pH hysteresis and drift properties than that of the conventional planar type EIS sensor. The increases in pH sensitivity, hysteresis and drift are attributable to the extended surface area of the EIS sensors enabled by the NWs.

Si-doped GaAs nanowires (NWs) were grown on (111)Si substrate by MBE-VLS method. The electrical characteristics of the GaAs NWs were measured. A joule heater was arranged near the tip of NW for making the gradient of substrate temperature. The obtained Seebeck coefficient of the GaAs NW increases linearly with a rise in temperature. The thermoelectric power of the Si doped GaAs NW was determined by the hole diffusion. It was estimated that the hole density in the Si-doped GaAs NW at room temperature was 5.9×1018 cm-3 from the slope of the temperature dependence of the Seebeck coefficient in the Si-doped GaAs NW. At room temperature, the Seebeck coefficient, thermoelectric power factor, and thermoelectric figure of merit (ZT) were 429 μV/K, 271μW/mK2, and 1.5×10-3, respectively.

Methotrexate (MTX), is a potent immunomodulating drug and widely used in the treatment of cancer, psoriasis and others disease. Despite its efficacy, the use of MTX is greatly limited due to its toxicity. To solve this problem, we prepared nanoparticles of tetraethyl orthosilicate (NP-TEOS) containing the compound methotrexate (MTX), by the sol-gel method. This drug delivery system (DDS) showed a loading efficiency of 39.7%. Size distribution studies were performed with dynamic light scattering and scanning electron microscopy revealing that these particles were spherical in shape, with a mean diameter between 140-430 nm and a low polydispersity (0.12 – 0.26). Also the particles displayed a low tendency toward aggregation which was confirmed by the low zeta potential -61.4 mV. Profile release showed a slow release loaded with MTX (PBS buffer pH = 7.4). The slow release can be attributed to the low porosity of the NP-TEOS and the extremely low diffusivity of MTX in aqueous media. B16-F10 cells were used to assay the toxicity and uptake of NP-TEOS showing to be nontoxic without MTX making a good candidate for DDS.

A synthetic strategy to couple selectively an ionic complementary thiolmodified octapeptide, that is able to gel at low temperature, to thethermoresponsive polymer poly(N-isopropylacrylamide) (pNIPAAm) withcontrolled molecular weight and narrow polydispersity is described. Thepolymer was synthesized by atom transfer radical polymerization (ATRP)affording halogen functionalized chain ends. This allowed subsequentcoupling to a thiol terminated ionic complementary octapeptide via nucleophile substitution. Results indicated that thepeptide was covalently attached to the polymer and that both thecoil-globule phase transition of pNIPAAm and the gelation properties of thepeptide were retained in the conjugated product. This method provides aversatile route for the synthesis of a range of bioconjugate materials withcontrolled architecture and dual self-assembling and thermoresponsivebehavior.

We have examined the intrinsic surface physical property of a CrO2 thin film by means of surface sensitive photoemission spectroscopy. Epitaxial thin film of CrO2(100) has been grown on TiO2(100) by a closed chemical vapor deposition method using a Cr8O21 precursor. Low-energy electron diffraction (LEED) observations find that epitaxial growth of rutile-phase CrO2 occurs to the top monolayer of the film. Surface sensitive x-ray photoemission spectroscopy (XPS) measurements show a finite intensity in the region of the Fermi energy. The result evidences that the physical nature of near topmost layer of CrO2 thin film is metallic. Progress of understanding of the surface physical property of CrO2 thin film helps not only perform a reliable photoemission study to understand the physics of ferromagnetic metal in CrO2, but also develop the CrO2-based devices using a half-metallic nature for spintronics applications.

Bentonite is planned to be used in many countries as a buffer material in repositories for spent nuclear fuel. The proper understanding and modelling of the functioning of the water-saturated bentonite requires knowledge about the bentonite microstructure and also the way water is distributed between different phases. This paper presents experimental results from our studies of water in compacted, water-saturated MX-80 bentonite at dry densities in the range 0.7-1.6 g/cm3. Three techniques, Cl-porosity, SAXS and proton NMR measurements, were applied to samples kept at room temperature, while TEM imaging was applied to high pressure frozen samples. The combined results of these techniques strongly indicate that the two major water phases in the compacted MX-80 bentonite samples are ‘interlayer’ and ‘non-interlayer’ water. The results of the relative amounts of different water types by SAXS and NMR are very similar. The results by Cl-porosity measurement indicate that only part of the non-interlayer water is available for anions. Those observations are discussed in comparison to TEM micrographs. Our study provides solid experimental evidence for the presence of two major water phases in water-saturated bentonite and estimates their relative proportions and pore sizes.

Thin film silicon solar cells are an attractive option for the production of sustainable energy but their low response at long wavelengths requires additional measures for absorption enhancement. The most successful concepts are based on light scattering interface textures whose understanding is greatly facilitated by considering a superposition of periodic textures that diffract the light into oblique angles, ideally beyond the critical angle of total internal reflection. Because the thickness of the active layers is on the same scale as the wavelength, interference of diffracted waves gives rise to resonance phenomena. We discuss the absorption enhancement in terms of a perturbation approach using the modal structure of a corresponding device with flat interfaces.

In this paper we introduce a novel, flexible, system for mechanical deformation detection. The core of the system is based on an Organic Thin Film Transistor (OTFT) which has been assembled on a flexible PET substrate and patterned by means of inkjet printing. OTFT-based mechanical sensors were fabricated employing two different organic semiconductors, namely a small molecule (pentacene) deposited by thermal evaporation and its solution-processable derivative 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) deposited by drop casting. It will be shown that the surface deformation induced by an external mechanical stimulus gives rise in both cases to a marked, reproducible and reversible (within a certain rage of surface deformation) variation of the device output current. Starting from these results, more complex structures such as arrays and matrices of OTFT-based mechanical sensors have been fabricated by means of inkjet printing. Thanks to the flexibility of the introduced structure, we will show that the presented system can be transferred on different surfaces (hard and soft) and employed for a wide range of applications. In particular, we have designed and fabricated a fully functional system based on a matrix of 64 elements that can be employed for detecting mechanical stimuli over larger areas, and will demonstrate that such a system can be successfully employed for tactile transduction in the realization of artificial “robot skins”.