Thin anodic porous alumina (tAPA), engineered by electrochemical anodization of aluminum and post-fabrication etching, has already shown surface-enhanced Raman scattering (SERS) activity, after overcoating with a thin gold film. On the other hand, the tAPA nanoporous surface, which is biocompatible and presents controlled roughness, has been extensively investigated as a substrate for living cell cultures. Here, we are interested in exploiting the nanoporosity of tAPA as a drug reservoir and demonstrating drug-delivery capabilities of these substrates which can be combined with the above cell-seeding and SERS activities. We focused on the loading/elution of a test drug, the nonsteroidal anti-inflammatory and analgesic molecule Diclofenac. We carried out pore loading of differently concentrated aqueous solutions of the test drug, and characterized the elution profiles by UV-Vis absorbance, using the lipid bilayers coated on the top surface as a mechanism for retarded elution from the pores, providing a more sustained release. We also demonstrated that, by changing an environmental parameter such as the pH, we can trigger an increased release of the drug. Additionally, we investigated the tAPA adsorption properties by quartz crystal microbalance technique with dissipation monitoring (QCM-D). For the purpose, anodization was carried out on an Al-coated quartz, which resulted in successful fabrication of tAPA on the sensor. Finally, the process of lipid bilayer formation on the nanoporous sensor, as well as the test drug loading, was demonstrated by QCM-D.

Given the lack of satisfying treatments for consolidating marble affected by thermally induced grain detachment (the so-called "sugaring"), the use of aqueous solutions of diammonium hydrogen phosphate (DAP) has recently been proposed. The idea is to form a new binding mineral (hydroxyapatite, HAP) as the reaction product between the DAP solution and the calcitic substrate. In this study, we investigated the effects of adding small quantities of ethanol (EtOH) to the DAP solution, with the aim of favoring HAP formation. The results of the study indicate that, when a 0.1 M DAP and 0.1 mM CaCl2 solution in 10 vol% EtOH is used, complete coverage of marble surface with a crack-free coating with reduced porosity is achieved (whereas no coating is formed without EtOH addition). This is thought to be a consequence of the weakening of hydration shells of phosphate ions in the DAP solution, thanks to the presence of ethanol molecules. When used to restore mechanical properties of weathered marble, the treatment with 10 vol% EtOH was found to significantly improve the dynamic elastic modulus after a single application and to completely restore it after a second application.

Light collection efficiency and specific molecular detection are crucial factors for the performance of bio-chemical molecule sensors. In this paper, the low optical-reflection silicon (Si) substrates which combine reduced optical reflectivity by light trapping effect and high Raman enhancement ability of gold nanoparticles (Au-NPs) coated textured Si substrates are investigated for surface-enhanced Raman scattering (SERS). A fast, single-step and highly controllable nanosecond (ns) laser processing technique is employed to fabricate textured Si substrates under ambient conditions. Parallel arrays of micro-pyramids are fabricated on Si surface by direct laser writing two-dimensional structures. SEM micrographs clearly show well-ordered surface features in the form of micro-pyramid shape with well-defined sharp tips on the laser processed Si substrates. The aggregation of Si micro/nanoparticles on Si surface forms nanocavities and nanogaps and further enhances the surface roughness in order to minimize the optical reflection. The low optical reflection Si substrates exhibit optical reflection below 15% over a broad wavelength range from 300 nm to 1200 nm. The textured Si substrates with high signal reproducibility are successfully applied as SERS substrates to detect a very small concentration of Rhodamine B molecules with an average enhancement factor of the order of ∼107. The low optical reflection and SERS signal amplification are also altered by the variation of laser pulse energy resulting into low optical reflection and high SERS signal intensity over the entire laser-patterned area. The effect of surface roughness on water contact angle was studied after the modification with Polydimethylsiloxane (PDMS), the surfaces show perfect superhydrophobicity with almost no water adhesion. This approach provides a novel high-speed and cost-effective method for fabricating SERS substrate with micro/nano-scale surfaces roughness and low optical reflection for high Raman signal enhancement.

The promise of nanocomposites lies in their multi-functionality, the possibility of realizing unique combinations of properties that are not attainable in traditional materials. Ceramic/metal multilayers (CMMs) are one such unique combination that are becoming increasingly popular among researchers today. The idea is to combine the superior properties of ceramics like hardness and strength with favorable properties of metal such as ductility. Materials with these characteristics have potential for engineering applications such as highly efficient gas turbines, aerospace materials, automobiles, protective coatings, etc. Molecular dynamics atomistic simulations were performed to study the scratch behavior of different models of niobium carbide (NbC)-niobium (Nb) multilayers. The layer thicknesses were varied and the coefficient of friction was calculated at various depths of indentation. The deformation mechanisms were investigated to explain the observed mechanical behavior of the models under scratching. Model with the lowest metal/ceramic thickness ratio (2nm NbC/2nm Nb) showed the highest hardness, highest scratch resistance, and also highest friction coefficient. However, this model also showed the highest materials removal rate.

Decorative, polychrome ceramics from Corinth, Greece, produced during the 8th-6th centuries B.C.E. were luxury goods widely traded throughout Greece and the Mediterranean. Corinthian pottery is the first 5-color polychrome ceramic technology, having slip-glazes in distinctive white, black, red, yellow, and purple colors, and in a variety of surface finishes from glossy, to semi-matte, to matte. The firing temperature range, 925-1075°C, was determined experimentally to be to be higher than previously reported, similar to the Corinthian amphorae and other ceramic products. This firing range is higher than that of the better known, more prestigious Athenian Black-figure and Red-figure ceramics. In this study three examples of Corinthian and one example of Athenian Black-figure ceramics from the Marie Farnsworth collection at the University of Arizona were tested and compared to thirteen clays from Corinth. Analytical techniques included Fourier-transform infrared spectroscopy (FTIR), scanning-electron microscopy with energy-dispersive spectroscopy (SEM-EDS), micro-Raman spectroscopy, and wavelength-dispersive electron microprobe (EPMA with BSE-SEM).

Artisans in Corinthian workshops experimented to change the colors of the slips by varying the type and amount of iron-rich raw material, as well as the composition of the clay used as a binder and the amount of flux used as a sintering aid to promote glass formation. Corinthian artisans developed not only different recipes to produce the various colors, but also they were able to control raw-material particle size and composition to produce variations in surface luster (matte, semi-matte and glossy). This research suggests that Corinthian polychrome-slip technology was based on careful control of particle processing, of compositional control of raw materials and their admixtures, and of firing temperature. The behavior or practice of adding different ratios of pigments and glass-forming fluxes to form various optical effects implies a detailed knowledge of what happens when these are heated and fired. This is a process of experimentation focused on developing a distinctive craft practice, which produced a distinctive and highly valued material. The Corinthians developed a more complex, easily recognizable, and culturally distinctive ceramic technology that was intentionally established as a cultural brand, and probably as a luxury brand of high socio-economic value. This research deepens our understanding of the complex pigment processing and firing technologies employed in the production of Corinthian ceramics.

Cold atmospheric pressure plasma has been intensively studied due to growing interest in biomedical applications. For example, it has been revealed that the plasma-irradiated cell culture medium (PAM: Plasma Activated Medium) shows antitumor effect as well as the direct plasma treatment. Long-lived reactive oxygen and nitrogen species (RONS), such as hydrogen peroxide (H2O2), nitrite (NO2-), and nitrate (NO3-), are considered as a main product in PAM. Therefore, investigation of the production characteristics of RONS in PAM with different experimental parameters is important. Here, we focused on humidification of feed gas (argon or helium) and effect of gap between the nozzle of the plasma jet and liquid surface. As a result, H2O2 concentration was increased by humidification of both feed gases. However, the concentration of NO2- and NO3- was decreased by the humidification of helium. In addition, the remarkable effect of the humidification on H2O2 production was observed when the plasma jet was in contact with the liquid surface.

In ab initio modeling of doped semiconductors, estimation of defect formation energies involving substitutional sites of ternary compounds is ambiguous due to an approximate treatment of chemical potential of the substituted atoms. We propose a model of assigning fractions of the formation energy to individual atoms of a ternary semiconductor and test it on InGaAs. The accuracy of this approximation is on the order of 0.1 eV/atom and is expected to be sufficient for many practical purposes.

In this study, we present the coupling between InAs submonolayer (SML) and stranski krastanov (SK) quantum dots (QDs). Interaction between these two different dot families has been manipulated by changing the capping layer thickness. Significant shift in photoluminescence (PL) peak is observed due to the coupling effect. The dynamics of the carriers in this mixed dot matrix has also been modified, which is evident from the increasing activation energy with increasing thickness of the capping layer. Moreover, an ex situ annealing study at different temperatures has been done to check the thermal stability of the as-grown samples. Annealing at lower temperatures, improves the crystal quality a bit, but higher annealing temperatures accelerate the In-Ga interdiffusion and form smaller dots, which is visible from a blue shift in the PL peak of annealed samples. Also, this thermal process improves the dot size distribution.

Zinc orange is a rare and relatively undocumented pigment. Mention of this pigment in the literature indicated its short lived availability to artists in the nineteenth century and that it is unstable, but does not address any specific issues related to its degradation. The synthesis of the original pigment is discussed. In addition, a full characterization of the pigment is presented including XRF, FTIR, Raman and optical microscopy. Research into its degradation mechanisms was also undertaken, and the light fastness of the pigment is presented.

Gold/albumin core/shell nanoparticles (Au/AlbNPs) was prepared by a novel aggregation/crosslinking technique and characterized by several spectroscopic and microscopy methods. Albumin, in presence of gold nanoparticles (AuNPs), is aggregated by the addition of ethanol and further stabilized by radiation-induced crosslinking using a 60Co source. Nanoconstructs are characterized to determine size, morphology and optical characteristics. The Au/AlbNPs were prepared in different ethanol and albumins concentrations. Results showed that it is possible to obtain Au/AlbNPs using ethanol 30 %v/v, albumin in different concentrations and an irradiation dose of 10 kGy. Au/AlbNP plasmon peak shifted to 530 nm, keeping the typical plasmon peak shape. The size of Au/AlbNPs is approximately double respect to the naked AuNPs and they show core/shell type morphology. The main amide peaks of albumin in FTIR spectrum can be found in the spectrum of nanoconstructs.

The three-dimensional (3D) culture of neural cells in extracellular matrix (ECM) gels holds promise for modeling neurodegenerative diseases and pre-clinical evaluation of novel therapeutics. However, most current strategies for fabricating 3D neural cell cultures are not well suited to automated production and analysis. Here, we present a facile, replicable, 3D cell culture system that is compatible with standard laboratory equipment and high-throughput workflows. This system uses aqueous two-phase systems (ATPSs) to confine small volumes (5 and 10 μl) of a commonly used ECM hydrogel (Matrigel) into thin, discrete layers, enabling highly-uniform production of 3D neural cell cultures in a 96-well plate format. These 3D neural cell cultures can be readily analyzed by epifluorescence microscopy and microplate reader. Our preliminary results show that many common polymers used in ATPSs interfere with Matrigel gelation and instead form fibrous precipitates. However, 0.5% hydroxypropyl methylcellulose (HPMC) and 2.5% dextran 10 kDa (D10) were observed to retain Matrigel integrity and had minimal impact on cell viability. This novel system offers a promising yet accessible platform for high-throughput fabrication of 3D neural tissues using readily available and cost-effective materials.

Composite nanostructured foams consisting of a metallic shell deposited on a polymeric core were formed by plating copper via electroless deposition on electrospun polycaprolactone (PCL) fiber mats. The final structure consisted of 1000-nm scale PCL fibers coated with 100s of nm of copper, leading to final core-shell thicknesses on the order of 1000-3000 nm. The resulting open cell, core-shell foams had relative densities between 4 and 15 %. By controlling the composition of the adjuncts in the plating bath, particularly the composition of formaldehyde, the relative thickness of copper coating as the fiber diameter could be controlled. As-spun PCL mats had a nominal compressive modulus on the order of 0.1 MPa; adding a uniform metallic shell increased the modulus up to 2 MPa for sub-10 % relative density foams. A computational materials science analysis using density functional theory was used to explore the effects pre-treatment with Pd may have on the density of nuclei formed during electroless plating.

Due to the rapid development of advanced additive manufacturing production routes in recent years, the demand of high-quality alloy powders is significantly increased. We studied gas-atomised spherical powders of several Nb-bearing γ-TiAl based alloys, Ti-45Al-10Nb and Ti-45Al-5Nb-xC in at.% (x = 0, 0.5, 0.75, and 1), which were produced using the plasma melting induction guided gas atomization (PIGA) technique. The phase constitution of different powder fractions was determined by synchrotron high-energy X-ray diffraction at the HEMS beamline DESY (Germany), as well as by SEM, EDX and EBSD measurements. Due to the high cooling rates in the range of 105 K/s, the powder particles mainly consist of hexagonal close packed α-Ti(Al) and body centred cubic β-Ti(Al)-phase. As the cooling rate depends on the particle size, considerable amounts of the β-phase were only found in the small powder fractions (< 45 μm). The total β-phase amount was generally higher in the alloy with a higher Nb content, and also the effect of carbon as a α2-stabilizer was observed. Dendritic cauliflower-like structures are more pronounced in bigger powder particles due to the slower solidification and thus a higher Nb depletion in the remaining melt.

In coarse grained molecular dynamics (CGMD) simulations, small groups of atoms are treated as single particles (beads) and the forces between these particles are derived from the interatomic forces. The effect of this is to severely reduce the number of particles in a simulation, thereby allowing for the consideration of a larger number of atoms. It has also proven to be a valuable tool in probing time and length scales of systems beyond that used in all-atom molecular dynamics (AAMD) simulations. The down side of this is that the inter-particle interactions are less accurate. However, if these coarse grained particles are chosen carefully, such simulations can provide much useful information. There are different levels of how the coarse grains are constructed. For example, CG systems have been developed using tens or hundreds of atoms per CG bead in some studies of amino acids in biological science. By contrast, for other systems, a single CG bead is used to replace just two or three atoms.

In this paper, the interaction of a carbon nanotube (CNT) with a lipid bilayer membrane is studied using both coarse grained and atomistic MD in an effort to understand the usefulness of the CGMD method for such simulations. Our preliminary studies of the interaction of a CNT with a lipid bilayer points indicates that such nano-tubes inserted into a membrane could be stable. This means that it could be used as an agent in the delivery of drugs. It would be good if these simulations could be repeated using AAMD simulations to confirm the validity of these results.

The surfaces of 30 pieces of glass from panel 3b of the Great East Window of York Minster (1405-1408 CE) were analyzed by handheld portable X-ray fluorescence (pXRF) and small samples from the same pieces were analyzed by electron microprobe (EPMA). Comparison of the two methods reveals significant divergences which are not systematic, particularly for elements lighter than Ti. Rather than a problem with pXRF calibration or correction software, the non-systematic error is attributable to the presence of a thin surface layer of weathered glass. Analysis of the depths of X-ray generation indicate that virtually all X-rays characteristic of Ca and K are generated within the top 50 µm of the glass. However, for heavier elements such as Rb, Sr and Zr, most emitted X-rays are generated below 100 µm. Using pXRF data for the heavier elements, it is possible to replicate the compositional groupings identified by quantitative EPMA. White glass in the window is likely to have originated in England, while colored glasses were probably obtained from the Continent. The alkali contents of the green and yellow glasses appear to have been manipulated to generate their colors. Glass which is medieval in technology but not original to the panel was identified. In particular, zirconium proved a useful indicator of glassmaking regions, and rubidium and strontium were more sensitive to differences between batches, which has interesting implications for future work.

In this work, we investigate a novel synthesis route for the synthesis of LiFePO4 material that utilizes an ionic liquid/water composite medium. The effect of reaction time and reaction temperature on the crystallinity of synthesized material is investigated through X-ray diffraction (XRD). Morphology is analyzed through scanning electron microscopy (SEM). It is observed that the intensity of peaks corresponding to LiFePO4 increase as reaction time increases, but unwanted peaks are present as well. SEM characterization indicates that various structures are initially formed, but as the reaction time progresses product morphology changes in size.

The union of the unique diamond properties with steel (most common substrate material) provides a new solution for machine parts under critical mechanical conditions and severe environmental. However, CVD diamond coating directly on steel comes with several issues. The fundamental reasons for the lack of adhesion are an iron catalytic effect, the high carbon solubility in iron and high mismatch in thermal expansion coefficient of diamond and steel. The use of interlayer may solve these issues acting as a diffusion barrier, for both iron and carbon, and match thermal expansion coefficients. Several articles describe the PVD deposition or electroplated interlayer. In the present study, the diamond film coated steel with an intermediate barrier deposited by laser cladding process. In this novel technique, laser irradiation melts the powder (preplaced) and the substrate surface to create the coating on a steel substrate. We used the SiC/Ti and SiC/Cu powder mixtures to create the intermediate barrier. Diamond film deposition was carried out in an HFCVD reactor (Hot Filament Chemical Vapor Deposition). The samples characterization included X-ray Diffraction (XRD); Field Emission Gun - Scanning Electron Microscopy (FEG-SEM) and Raman Scattering Spectroscopy (RSS). Results showed that laser incidence dissociated partially the SiC powder, forming FeSi, Cu3Si phases. Further, the composite layer assisted the high thermal stress relief in steel/diamond interface.

This comparative study on two interdisciplinary artistic practices aims to improve public perception of scientific research and to facilitate informed decision making regarding climate change and how it affects everyday life. It also hopes to break down (or bridge?) the isolated silos of Art and Science, by emphasizing the role of imagination as a tool of creation and innovation in the new economies of the 21st century. Notwithstanding the ephemeral appearance of the super-light nanomaterial silica aerogel used by Ioannis Michaloudis (Michalous) in his sculptures, the longevity of some of his art seems guaranteed: two works, Bottled Nymph and Noli Me Tangere have been selected to be rocketed to the moon as part of the MoonArk sculpture. The sculptures will be aboard a Space X Falcon 9 rocket launched in 2018 from Cape Kennedy in an Astrobotic Robotic Lunar Mission, and will remain on the moon, potentially, for billions of years. Spirited Skies is a project where we experience by touching other forms of longevity of the ephemeral silica aerogel. Filling double jacketed borosilicate glass vials with aerogel skies and clouds in a unique way, Michaloudis transforms every day’s life trivial objects into art. And whilst Michaloudis is seeding the heavens and landing his artwork onto the moon, a Masters student under his supervision, Matthew van Roden is waxing and waning back here on earth. Van Roden’s material of choice is wax, which he pushes through various artistic disciplines to extrapolate its flesh like qualities.

The impact of different annealing temperatures on the crystal structure, emission and radiative defects in ZnO nanocrystals (NCs) has been investigated by means of the scanning electron microscopy (SEM), Energy dispersion spectroscopy (EDS), X-ray diffraction (XRD) and photoluminescence (PL) techniques. ZnO NCs were prepared by the anodization of zinc sheets in an electrolyte and thermal annealed at the various temperatures: 200, 240, 280, 320, 360 and 400°C for two hours in ambient air. The XRD study indicates that ZnO NCs are characterized by the hexagonal wurtzite structure.

The study of annealing temperature impact on the morphology of ZnO NCs has shown that the NC size enlarges and the film crystallinity improves with increasing annealing temperatures from 200°C up to 400°C. But in the temperature range of 360-400oC the dissolution of oxygen atoms raises essentially in ZnO NC films as it follows from EDS data. Simultaneously, the near band edge (NBE) emission intensity falls down, XRD parameters of ZnO NCs change and the intensity of defect related orange and green PL bands increases owing to increasing the defect concentrations. The optimal temperatures for the ZnO NC oxidation, together with keeping the high NBE emission intensity, are estimated as 360 °C. The nature of native defects responsible for orange and green emissions in ZnO NCs has been discussed.

The high field electric breakdown of polyethylene/montmorillonite nanocomposites was studied in detail, and compared to the unfilled respective films. The electric breakdown strength (EBD) of ‘aligned’ composite films (i.e., films with fillers oriented parallel to the film surface) is much higher than the EBD of the respective ‘isotropic’ composites (i.e., films with fillers of random orientation) and of the unfilled polymer films. This behavior suggests a barrier mechanism as the origin of electric strength improvement, a supposition that was investigated in detail here and is supported by: (a) EBD is not related to filler-induced or strain-induced polymer crystallinity changes; (b) EBD decreases with modulus, but improves with toughness for these films; (c) there is no change in the polymer EBD for a small temperature jump (ΔT from 25 °C to 70 °C), but there is a definitive change in the composite EBD for the same ΔT. All these, support the postulation that the electrical breakdown of these systems is predominately through thermal degradation mechanisms, which can be affected by the existence of oriented inorganic nanofillers (and of oriented polymer crystallites). Thus, the controlled orientation of nanofillers is shown to be an effective approach to substantially improve the electric breakdown strength of PE dielectric/insulating films.