A systematic study was carried out to determine the effect of the composition and annealing atmosphere (air and N2) on the structural, optical and magnetic properties of pure, doped and co-doped ZnO [Zn(1-y)(CoV)yO] nanocrystalline powders and films. The (Co+V) doping level, ‘y’, was fixed at 2 at% with variable individual concentrations of Co and V species. Powders and films were synthesized via a sol-gel approach where the films were grown on silicon (100) substrates. X-ray diffractometry verified the formation of the ZnO host structure after annealing of the precursor phases. The variation of the average crystallite size of Co-V (2 at.%) ZnO powders annealed in air at 500°C were negligible and averaged 33 nm. Photoluminescence (PL) measurements of powder corroborated the formation of high-quality ZnO host structure, as well as in films annealed in air. In turn, XRD and PL measurements confirmed an enhanced crystallinity of the ZnO host, with an average crystallite size of 41 nm, for films annealed at 500°C under a N2 atmosphere. M-H measurements evidenced a ferromagnetic behavior at room temperature in powders and films that was dependent on the type and amount of the dopant species.

The phase-change-memory (PCM) relies on the ability of a chalcogenide material, usually Ge2Sb2Te5 (GST), to switch from the amorphous phase with a high electrical resistance (~MΩ) to a crystalline phase with a low electrical resistance (∼kΩ). The structural stability of the amorphous phase is critically affected by temperature-activated crystallization and resistance drift due to structural relaxation (SR) [1]. While amorphous chalcogenides are relatively stable with respect to crystallization, thanks to a high activation energy above 2 eV [2], the lower activation energy of SR can strongly affect the PCM electrical properties of the amorphous phase, including resistance, activation energy for conduction and, most importantly, the threshold voltage VT. The latter marks the boundary between read and programming operations in PCM, thus VT instability must be carefully predicted to minimize read disturbs within the array. To this purpose, understanding the switching mechanisms and modeling of VT is of utmost importance for PCM device development and scaling.

Using a N2 gas plasma apparatus (BLP-TES, NGK Insulators, Ltd), we showed that N2 gas plasma treatment of influenza A virus caused degradation of viral nucleoproteins. These findings suggest that N2 gas plasma treatment may contribute to infection prevention control for influenza.

Understanding the dynamic responses of energetic materials is central to evaluating the energetic and chemical performance as well as development of novel energetic solids. These include thermal, mechanical and chemical processes in a relevant temporal (ns-to-μs) and spatial (atomistic-to-micro) scales. In this paper, we describe our recent developments of time-resolved characterization techniques capable of probing real-time structural and chemical evolutions across single event, metal combustions and intermetallic reactions. The methods utilize highspeed microphotography, spectro-pyrometry, and synchrotron x-ray powder diffraction and determine in-situ the particle sizes, temperatures and structures in μs time resolution. These timeresolved data provide insights into the fragmentation dynamics, thermal history, phase transitions, reaction mechanisms, and chemical kinetics governing these exothermic metal combustions and intermetallic reactions.

A general chemistry experiment has been adapted in which electrochemical principles in fuel cells are applied to the curriculum, thus bringing research into the classroom. It is well documented that students struggle in understanding redox reactions, in particular when applied to an electrochemical cell. There are three basic concepts needed to analyze these energy devices: anode, cathode and electrolyte.

In the proposed experiment, undergraduate students explored the role on an electrolyte in an electrochemical cell. Inquiry based methods were used to introduce the experiment. Explanations of fundamental electrochemical concepts involved in fuel cells were introduced to the students with pre- and post-laboratory activities and experimental results discussions. The lesson for the experiment “role of an electrolyte in an electrochemical cell” was planned to improve students’ technological skills and application of knowledge acquired in daily life. The battery was made using household materials: zinc, copper and napkin paper soaked in different electrolyte solutions. Students correlated the voltage of the cells with the substances being used in the experiment and classified these as strong electrolyte, weak electrolyte or non electrolyte. A variety of assessment tools were designed and incorporated during the experience to probe students understanding in the main topics and to identify the struggles during their learning process.

This paper presents the analysis of Raman scattering spectra of CdSe/ZnS QDs covered by the amine-derivatized polyethylene glycol (PEG) polymer with and without bioconjugation to bio-molecules: mouse ovarian cancer (OC 125) antibodies (mab). Commercial CdSe/ZnS QDs used in the study are characterized by the color emission with the maximum at 525 nm (2.36 eV) at 300K. Samples of CdSe/ZnS QDs (bio-conjugated and non -conjugated) in the form of an 5 mm-size spot were dried on a polished surface of crystalline Si substrate to ensure a low level of light scattering background.

Raman scattering spectra of non-conjugated QDs can be presented as a superposition of Raman lines: 212.2, 222.5, 308.3, 440.3, 521.0, 618.0, 667.8 943.5, 986.7, cm-1 related to the CdSe core and silicon substrate. The Raman lines 1003.9, 1317.8, 1452.9, 1656.8, 2870.4, 2931.8 and 3059.9 cm-1 deal with the vibration of COH, CH and OH groups of polymer, which covered QDs, were detected additionally. It is revealed that the QD bio-conjugation to the OC 125 antibodies is accompanied with the changes in the intensity of all types of Raman lines: related to the CdSe core, silicon substrate and polymer groups. The explanation of bioconjugation effects has been proposed and discussed.

Surface modification is an important part of fabricating nanoparticles with specific properties and functions. We have designed a dipeptide, which we call NS polypeptide, that consists of four asparagine (N) residues and one serine (S) residue, as a molecule for nanoparticle surface modification. Surface modification of magnetic nanoparticles with the NS polypeptide results in reduction of particle-particle and particle-cell interactions. Here, we describe the surface modification and functionalization of bacterial magnetic particles (BacMPs) by spontaneous integration of temporin L conjugated to NS polypeptide. BacMP membranes were modified temporin L. Furthermore, peptide-modified BacMPs showed high dispersibility in aqueous solution compared to unmodified BacMPs. This surface modification technique may represent a new strategy for reducing non-specific binding of nanoparticles to proteins or cells for use in a variety of protein- or cell-associated applications.

The electrical characteristics of silicon nanowire (SiNW) solar cells with p-type hydrogenated amorphous silicon oxide (Eg =1.9 eV)/n-type SiNWs embedded in SiO2/n-type hydrogenated amorphous silicon (Eg =1.7 eV) structure have been investigated using a two-dimensional device simulator with taking the quantum size effects into account. The average bandgap of a SiNW embedded in SiO2 increased from 1.15 eV to 2.71 eV with decreasing the diameter from 10 nm to 1 nm due to the quantum size effect. It should be noted that under the sunlight with AM1.5G the open-circuit voltage (Voc ) of SiNW solar cells also increased to 1.54 V with decreasing the diameter of the SiNWs to 1 nm. This result suggests that it is possible to enhance the Voc by the quantum size effect and a SiNW is a promising material for the all silicon tandem solar cells.

Spray coating of a photoresist onto three-dimensional (3D) structure was investigated. To improve the uniformity of photoresist deposition onto the 3D structure, a shield plate with an aperture was used. The shield plate set over a sample permitted the resist deposition on the sample surface located in the aperture area while the plate blocked the deposition for the other area. The spray flow which is suitable for the resist deposition can be used effectively. Numerical analysis revealed that the vertical velocity component of gas flow was enhanced in the aperture area. In the experiments of the spray coating, the difference between the resist film thicknesses deposited on top and bottom trench surfaces was decreased. On the trench sidewall, resist bump formation, which was frequently observed in spray coating, was suppressed. The uniform resist deposition is necessary to realize 3D microdevices by lithography. In the microfluidic devices of dielectrophoresis, aside from the top and botttom trench surfaces, the trench sidewall can be used to fabricate device structures such as electrode for dielectrophoresis.

In an attempt to develop conductive, biodegradable, mechanically strong, and biocompatible nerve conduits, pure magnesium (Mg) was used as the biodegradable substrate material to provide strength while the conductive polymer, poly(3,4ethylenedioxythiophene) (PEDOT) was used as a conductive coating material to control Mg degradation and improve cytocompatibility of Mg substrates. This study explored a series of electrochemical deposition conditions to produce a uniform, consistent PEDOT coating on Mg substrates. The microstructure and morphology of the coating and Mg were visualized using scanning electron microscopy (SEM). The elemental composition of the surface was quantified using energy dispersive X-ray spectroscopy (EDS). Adhesion strength of the coating was measured using the tape test following the ASTM-D 3359 standard. The SEM results showed uniform and consistent PEDOT coating, and EDS analysis confirmed the elemental composition of PEDOT. The adhesion strength of PEDOT coating was within the classifications of 3B to 4B.

In the present study we have synthesized Ni/NiO nanocomposite was synthesized via microwave assisted rapid chemical route. The electrochemical properties of the composite was studied and found to be showing better performance in presence of metallic nickel in presence of its oxide.

Blue-green emitted barium silicate phosphors, Ba4Si6O16:Eu2+ and Ba5Si8O21:Eu2+, were prepared by a conventional solid-state reaction. In these hosts, the corner-sharing [SiO4] tetrahedral formed a chain framework structure. These silicate phosphors can be efficiently excited by n-UV light, yielding an intense blue-green emission. Under excitation by near UV light, the emission bands are broader than that of the Ba2SiO4:Eu2+ phosphor.

Oxides with fluorite (or fluorite related) structures form a large class of compounds with a high radiation tolerance, somewhat related to their peculiar ability to accommodate a variety of defects and to form nonstoichiometric compounds with a large homogeneity range. Structural modifications are generally observed when the departure from the ideal composition is large. We discuss these structural features using an approach based on the crystal symmetry analysis based on the phase transition mechanisms in compounds relevant for nuclear applications.

Reaction centers (RCs) from natural photosynthetic cells are photoactive proteins, which generate electron-hole pairs in presence of light. In a new approach presented in this work, a solution of suspended RCs with mediators has been applied as the electrolyte to build electrochemical based photovoltaic (PV) devices. In this approach, the mediators transfer charges from the RCs to the electrodes (indirect charge transfer). Various metallic and wide bandgap semiconducting materials, including Carbon, Au, Indium Tin Oxide (ITO), SnO2, WO3, have been tested as the electrodes. Among all WO3, which is a semiconductor, have shown the largest photocurrent density with an amount of ∼5.1 μA/cm2. The results show that the material of the electrode can affect the rates of the reactions in the cell. Choosing an appropriate material for the electrode, the charge transfer from the mediators to the electrode would be rectified to achieve a large photocurrent.

In this paper, we report on deposition and properties of nanocrystalline Ge:H films . The films were grown from germane and hydrogen mixtures using Radio frequency Plasma-enhanced chemical vapor deposition (RF-PECVD) process using ∼45 MHz frequency. The crystallinity of the films was measured using Raman measurements and from x-ray diffraction techniques, it was found that the grain size was a strong function of deposition pressure, temperature and hydrogen/germane ratios. High hydrogen ratios and high powers led to films with smaller grains. Higher pressures and smaller hydrogen/germane ratio led to films with larger grain sizes, as did higher growth temperatures. The mobility of electrons and holes was measured using space charge limited current (SCLC) techniques in n+-n-n+ devices. It was found that nominally undoped films were generally n type with carrier concentrations in the 1E14/cm3 range. Mobility was found to increase with grain size, with 60 nm grains showing mobility in the 2-3 cm2/V-s range.

We theoretically study the spatial and temporal fluctuation of two electrons confined in a semiconductor quantum dot (QD). Eigenstates are determined by the resonating unrestricted Hartree-Fock (res-UHF) approach in order to take into account the electron correlation via the configuration interaction (CI). The time-dependent (TD) wave function is, then, expanded by the UHF solutions, and the CI treatment is combined with the TD Schrödinger equation (TD-CI). The present TD-CI approach has an advantage to study how the electron correlation fluctuates the multi-electron state spatially and/or temporally through the multi-reference description of many-electron wave functions.

We carried out laser ablation of three organic molecules, rubrene (Rb), Oralith Brilliant Pink R (BP) and quinacridonequinone (QQ) in a poor solvent, water. As a result, nanoparticles of BP and QQ were formed, but those of Rb were not formed because of photodissociation. For a rigid molecule, QQ, optical properties of colloidal solutions were investigated in relation to the size of the included nanoparticles. A linear correlation between the blue shift of the absorption peak energy and the decrease in the diameter of the nanoparticles was found, indicating that the nanoparticle diameter can be easily estimated from the absorption spectrum of a colloidal solution. From the solution, a nanoparticle film was fabricated on an electrode by the electrophoretic deposition method.

All the countries that operate commercial nuclear power plants are planning to dispose of the waste in underground geologically stable repositories. The materials being studied for the fabrication of the containers include carbon steel, stainless steel, copper, titanium and nickel alloys. The aim of this work is to review results from research performed using the alloys of interest regarding their resistance to environmentally assisted cracking (EAC) under simulated repository conditions. In general, it is concluded that the environments are mild and that the studied metals may not be susceptible to cracking under the planned emplacement conditions.

Boron-doped nanocrystalline diamond (BDND) films were grown on silicon substrates by hot filament chemical vapor deposition in Ar/H2/CH4 gas mixtures. The boron source was obtained from an additional H2 line passing through a bubbler containing B2O3 dissolved in methanol with different B/C ratios. The transition from ultrananocrystalline to nanocrystalline diamond films is clearly shown by the addition of boron dopant to the growth gas mixture. The morphology and structure of these films have markedly different properties. The top view and the cross section of the films were characterized by scanning electron microscopy showing the transition from ultrananocrystalline growth (renucleation process) to a columnar structure of NCD films. Finally, the grain size was obtained from X-ray diffraction patterns of the films. The diamond average grain size increased from 10 to 35 nm for films with 2000 and 30,000 ppm B/C, respectively.

The main objective of this work was to control and manipulate tuneable equilibrium structures in elastomeric spherical particles. The cross-linked urethane/urea polymeric spheres with two soft segments, polypropylene oxide and polybutadiene, were prepared by reacting a poly(propyleneoxide)-based triisocyanate-terminated prepolymer (PU) with poly(butadienediol) (PBDO), with different weight ratio. Wrinkling on elastomeric Janus spheres is induced by UV irradiation (λ=254 nm) and permanently imprinted by swelling the particles in an appropriate solvent, followed by drying. The surface tailoring of the Janus elastomeric spheres, found by SEM, is dependent on the PU/PBDO ratio and on the elastic properties of the particles.