Titanium dioxide nanotubes (TiO2-NT) have been synthesized via an electrochemical anodization strategy followed by calcination under different temperatures to form TiO2 nanostructures of anatase and rutile crystal phases. The nanotube-on-Ti structure is further used as a substrate for calcium hydroxyapatite (HAp) coating. The effect of TiO2 morphology and crystal phases (i.e. amorphous, anatase and rutile) on the coating efficiency of HAp has been investigated in comparison with HAp coating on bare Ti metal. The HAp coated TiO2-NT have been studied using X-ray absorption near-edge structure (XANES) at the Ti K- and Ca K-edge. The results show that TiO2 of amorphous and anatase phases are of comparably good performance for HAp crystallization, and both are better than rutile TiO2, while HAp is hardly found on bare Ti. The implications of the findings are discussed.

Electrospinning is an inexpensive and simple method of producing non-wovenfiber mats. Electrostatic forces are employed to produce the mats, whichintrinsically have larger specific surface to volume ratio and smaller poresthan traditional fibers. Fibrous mats are typically used in a wide varietyof industries such as filter media, tissue engineering, and sensors.Chitosan, the N-deacetylated derivative of chitin, isenvironmentally friendly, non-toxic, biodegradable, and anti-bacterial.However, due to chitosan’s solubility in aqueous acids, it is electrospunusing trifluoroacetic acid (TFA). Modified chitosans, such ascarboxymethylchitosan, are currently under investigation as a means ofcreating designed nanofibrous mats with specific chemistries. However,typically an entirely new set of electrospinning conditions has to bedeveloped for each novel chemistry due to differences in solubility andviscosity. In the present study, we have electrospun chitosan mats andpost-processed the fibers. Two different post-processing conditions wereemployed. One post-production procedure, featuring vapor-phaseglutaraldehyde, effectively crosslinks the fiber mats utilizing a Schiffbase imine functionality. In another post-processing procedure, the as-spunmats are solution-phase post-processed by chemically functionalizing themats with cyano, carboxylic acids and thiol groups. While both methodsmaintained fiber shape and characteristics, there is a definite increase infiber diameters due to processing. FTIR, NMR, SEM and tensile testing havebeen performed on the pre- or post-processed fiber mats. Investigations intothe percent modification are currently underway.

We show evidence of electrical and thermal conductivity percolation in polymer based carbon nanotube (CNT) composites, which follow power law variations with respect to the CNT concentrations in the matrix. The experimentally obtained percolation thresholds, i.e., ~ 0.074 vol % for single walled CNTs and ~ 2.0 vol % for multi-walled CNTs, were found to be aspect ratio dependent and in accordance with those determined theoretically from excluded volume percolation theory. A much greater enhancement, over 10 orders of magnitude, was obtained in the electrical conductivity at the percolation threshold, while a smaller increase of ~ 100 % was obtained in the thermal conductivity values. Such a difference is qualitatively explained on the basis of the respective conductivity contrast between the CNT filler and the polymer matrix.

Microtruss cellular materials are assemblies of struts with characteristic features in the μm to mm scale, arranged in a periodic, three-dimensional architecture. Compared to conventional cellular architectures (e.g. stochastic foams and honeycombs), they can possess improved structural efficiency, because externally applied loads are resolved axially along the constituent struts. We have recently fabricated composite microtruss materials by electrodepositing reinforcing nanocrystalline sleeves on tubular polymeric scaffolds. These materials can offer enhanced structural performance by exploiting advantageous properties along three length scales: the inherent strength of the electrodeposited material (grain size reduction to the nm scale), its location away from the bending axis of the struts (cross-sectional efficiency in the μm scale), and the spatial arrangement of the struts (architectural efficiency in the mm scale). This study uses finite element analysis and experimental methods to characterize the mechanical properties of these composite materials.

Inertial cavitation, namely the rapid expansion and subsequent violent collapse of micron-sized cavities under the effect of ultrasound-induced pressure variations, has widely been considered as an undesirable phenomenon for in-vivo biomedical applications. This is mainly because of its highly stochastic nature and difficulties in its reliable initiation in vivo using moderate ultrasound pressure levels. Methods of lowering the pressure required to initiate cavitation, which is known as the cavitation threshold, has been previously addressed with the use of ultrasound contrast agents in form of encapsulated stabilized micron sized bubbles. However, such agents do not readily extravasate into tumours and other target tissues due to their relatively large size. This paper investigates the engineering of core-shell nanoparticles and examines their ability to initiate inertial cavitation in the context of ultrasound-enhanced local drug delivery. The nanoparticulate formulations are size-engineered to target tumour vasculature whilst presenting high surface roughness, facilitating surface air entrapment upon drying. The core-shell nanoparticles have been demonstrated to substantially lower the cavitation threshold in aqueous solution, allowing the initiation of inertial cavitation with moderate ultrasound amplitudes and the low energy levels typically deployed by diagnostic systems. The peak focal pressure where the probability of cavitation is greater than 0.5 was found to decrease by factors of five to ten fold, dependant on particle size, total surface area and surface morphology.

Melt-growth simulations based on the molecular-dynamics method for both the Cu-Zr and Ni-Al crystalline nanowires of B2 structure are performed to produce metallic-glass nanowires of amorphous structure. Next, tensile deformations of these nanowires are simulated at various temperatures. For the sake of comparison, Cu-Zr and Ni-Al crystalline nanowires of B2 structure are also elongated. It is revealed that the tensile strength of the metallic-glass nanowires is third or fourth of the tensile strength of the crystalline nanowires. Increasing tensile strain, the Cu-Zr crystalline nanowires of B2 structure change their structure twice, whereas the metallic-glass nanowires only decrease their thicknesses locally, and necking takes place.

Results are presented for modeling the deposition of Ag and rutile TiO2. The model can be used to examine the effect of varying experimental parameters, such as the substrate bias in the magnetron and the stoichiometry of the deposition species. We illustrate how long time scale dynamics techniques can be used to model the process over experimental time scales. Long time dynamics is achieved through an on-the-fly Kinetic Monte Carlo (otf-KMC) method, which determines diffusion pathways and barriers, in parallel, with no prior knowledge of the involved transitions. Using this otf-KMC method we have modeled the deposition of Ag and TiO2 for various plasma deposition energies, in the range 1 eV to 100 eV. It was found that Ag {111} produces the most crystalline growth when deposited at 40 eV. TiO2 growth showed that at energies of 1 eV and 100 eV a porous structure occurs with void formation. At deposition energies of 30 eV and 40 eV, a more dense and crystalline rutile growth forms. The results show that deposition energy plays an important role in the resulting thin film quality and surface morphology.

Polydimethylsiloxane (PDMS) is one of the most used materials in bio-applications. However, previous works were mainly focus on the mechanical aspect. In this paper we presented a practical and efficient approach to enhance the electrical properties of PDMS by using conducting polymer nanowires (CPNWs). The nanowires were synthesized using template method and added in PDMS to form nanocomposites. The dielectric constants of the composites were characterized by impedance measurements, and the dielectric relaxation behavior and the volume fraction of CPNWs was investigated. Based on the percolation theory a much lower threshold (5.3 vol%) was achieved.

PbTe-PbS materials are promising for thermoelectric power generation applications. For the composition of (Pb0.95Sn0.05Te)0.92(PbS)0.08 nanostructuring from nucleation and growth and spinodal decomposition has been reported along with thermal conductivity of approximately 1.1 W/m·K at 650 K [1]. Based on temperature-dependent measurements of electrical conductivity, thermopower, and thermal conductivity, the thermoelectric figure of merit, ZT, are ~1.5 at 650 K for cast ingots.

To develop larger quantities of material for device fabrication, advancement in the synthesis, processing and production of (Pb0.95Sn0.05Te)0.92(PbS)0.08 is necessary. Powder processing of samples is a well-known technique for increasing sample strength, and uniformity. In this presentation, we show sample fabrication and processing details of pulsed electric current sintering (PECS) processed (Pb0.95Sn0.05Te)0.92(PbS)0.08 materials and their thermoelectric properties along with the latest advancements in the preparation of these materials.

Alternatives to ITO are under heavy investigation. Organic and inorganic transparent conducting materials are compared based on their transparency versus sheet resistance characteristics. Although graphene has advanced recently, TCOs are still superior in performance and can only be surpassed by the combination of transparent materials with a metal grid. Results on modeling and design optimization using a monolithically integrated CIGS cell configuration as case showed that considerable efficiency enhancement (up to 17% in power output compared to single TCOs) can be achieved for metal grid/TCO combinations. Conductivity improvement has been experimentally verified by four point probe measurements. on both commercial ITO coated PET foil as well as on ZnO coated glass with electrochemically deposited metal grids Sheet resistances as low as 0,1 Ohm/sq were reached and 80 times and 400 times conductivity improvements were obtained at a transparency loss of only 3% and 6%, respectively. It was also found that electrochemical deposition results in more conductive grids than obtained by Ag-ink screen printing due to higher aspect ratios and bulk-like conductivity of the first. Simultaneously, nanopatterning allows optimal grid width of 20 μm, as determined by modeling.

The p-type conduction in transparent Ga-doped SnO2 thin films was realized and its two origins were discerned through comparison experiments associated with growth conditions, Rutherford backscattering spectroscopy and x-ray photoelectron spectroscopy analysis. All the experiment results suggest that the adsorbed oxygen both in the grain boundaries and at the surfaces is another origin of the net hole conduction in the polycrystalline thin films. This mechanism provides a fairy well explanation for the growth temperature dependence of the p-type conductivities of the films. It also offers a useful guide to better the properties of p-type conducting oxide thin films.

Photoemission spectroscopy using synchrotron radiation was used to determine the energy level structure of Mn doped Li 2 B 4 O 7crystals. Photoemission studies provided evidence of Mn in the bulk crystal at 47.2 eV. Valence band analysis provided the presence of surface states but no acceptor sites. Cathodoluminescence studies were also made on undoped and Mn doped Li 2 B 4 O 7using various beam energies from 5 to 10 KeV at room temperature. Self trapped exciton emission states are evident in the undoped and Mn doped Li2B4O7 sample ranging in energies from 3.1 to 4.1 eV.

In order to obtain efficient light trapping within a thin-film silicon solar cell, randomly textured interfaces are used. The texture can be introduced by wet-chemical etching in diluted hyrdofluoric acid (HF). By varying of the HF concentration, a continuous transition to smaller surface structures can be achieved. Near-field scanning optical microscopy is applied to measure scattered light with sub-wavelength resolution. On those different surfaces, using Fourier high-pass filters on the measured near-field images, surface features with a high light trapping potential are identified. Finally, criteria for optimized scattering surfaces are obtained.

We prepared a photo-polymerizable compound of Au nanorods and methyl methacrylate (MMA). An irradiation of ultraviolet (UV) light onto the compound induces photo-polymerization of MMA, resulting in a formation of an Au nanorods/PMMA composite. Au nanorods were synthesized by seed-mediated growth method in aqueous solution. Hydrophobically functionalized Au nanorods were dispersed into MMA with a small amount of photosensitizer and initiator. We investigated the stability and the uniformity of the dispersion of Au nanorods during the photo-polymerization process through VIS-NIR absorption spectroscopy. We also demonstrated the use of the compound for two-photon micro/nanolithography.

Today the company seeks alternative natural medicine that are compatiblewith the body, which does not produce side effects and hang time are easilyaccessible and cost of those who currently have. The concern of researchersand specialists in the development of new materials is to seek, toexperiment and create products that can be useful and compatible with humanbeings so as to obtain a curative effect without a side effectoriginates.

The development of pharmacologically active materials has increased inrecent years. People lack access to most drugs and is therefore a need formore rapid and less expensive than current, which can be applied to cellularsystems in vitro, in order to evaluate the biocompatibility of newmaterials. The current study seeks to experiment in a new line of researchthat helps health care and have a better quality of life.

The excipients in the drug are auxiliary substances that help the activeingredient is the one with the therapeutic action, can be formulated in aneffective and pleasant for the patient. It is one or more substances thatare incorporated into the product to facilitate its preparation, maintenanceor administration. We therefore tested clay known as bentonite to serve as avehicle for transport of an active substance (ursolic acid) [1] and somescientific studies have shown that it possesses anti-inflammatory,antibacterial, antifungal and highly cytotoxic capacity. Both materials weremixed to generate a new biomaterial that has anti-inflammatory activity.Evaluation of this model was under the inhibition of edema produced by13-acetate-12-ortho-tetradecanoylphorbol (TPA) in mouse ear.

In the present study the α2 and the γ texture in a Ti-45Al (at.%) alloy were analyzed by means of x-ray diffraction after hot deformation. The initial Ti-45Al powder compact exhibits a random texture and shows a relatively high amount of α2 phase (about 34 vol.%). Various hot compression tests were performed at temperatures ranging from 700 °C to 1100 °C with strain rates of 5·10–4 s–1 and 5·10–2 s–1 up to a true deformation of ε = –1.

Depending on the deformation temperature the γ-TiAl deformation texture consists of pure deformation components (700 °C) or components completely related to dynamic recrystallization (1100 °C). In contrast to the γ phase the α2 phase shows no remarkable changing of the deformation texture with increasing temperature. The α2 deformation texture basically consists of a similar component as it is known from hexagonal α-Ti, namely a tilted basal fiber. However, a significant influence of the deformation rate on the α2 texture formation is observed at temperatures above 800 °C. With increasing deformation temperature the α2 texture strengthens by applying a high deformation rate, whereas it weakens for a low deformation rate. This contrary behavior is attributed to the interaction of the α2 and γ phases during texture formation.

High Mn TWinning-Induced Plasticity (TWIP) steels have mechanical properties which make them suitable for effective vehicle mass containment and an enhanced passenger safety in automotive applications. High Mn TWIP steels with additions of C and Al are fully austenitic at room temperature and have a stacking fault energy (SFE) within the narrow range of 20-30 mJ/m2 required for mechanical twin formation. The present contribution reviews the state-of-the-science on TWIP steels, and highlights those areas where there is still a lack of fundamental understanding of their properties, such as the effect of the anti-ferromagnetic transition, the influence of interstitial C, the twinning mechanism, the effect of slip and twinning on the crystallographic texture evolution and the delayed fracture phenomenon.