In this study, we use novel thermal deposition techniques to synthesize films of poly(vinlyidene fluoride), or PVDF, containing nanoparticles of the ceramic titanium dioxide (TiO2). This ferroelectric polymer has shown promise as a capacitor dielectric material, and possible enhanced electrical properties when combined with ceramic nanoparticles.Characterization of these composite films has been performed including chemical structure and microstructure using SFM, XPS, and EDS techniques. Measurements of film parameters such as dielectric constant and breakdown voltage have also been performed, and the dispersion of the ceramic particles within the films has been characterized

Magnetoelastic (ME) sensors provide a fast, sensitive method to detect bacteria with smaller sensors have higher mass sensitivity for detecting lower concentrations of bacteria. However, signals from smaller sensors are weaker and have more noise due to manufacturing defects. In this paper, we present a biosensor system for the detection of Salmonella typhimurium using multiple magnetoelastic sensors, each with the size of 2000 × 400 × 30 μm. The sensors are immobilized with E2 phage, which specifically binds with S. typhimurium. Unlike traditional methods, our system uses a step pulse to “shock” the sensor, causing it to vibrate at its natural resonance frequency and produce a signal in the pickup coil due to reverse magnetostriction. A Fast Fourier Transform (FFT) was used to determine the resonance frequency. As the biosensor captures S. typhimurium cells, its mass increases with a corresponding decrease of its resonance frequency.The detection system was composed of one coil with a reference sensor to monitor stability, and another coil with three measurement sensors separated in three tubes for simultaneous detection of bacteria. With multi-sensors the effect of a manufacturing defect is decreased and we get the benefit of averaging for more accurate and reliable results. Stability tests show that the variance of frequency detection is less than 122 ppm of its resonance frequency. SEM pictures of the sensor surface show a uniform binding of S. typhimurium cells. Cells were counted and the mass change calculated. The measured frequency change corresponds well to the theoretical change. The results show that the multiple phage based ME biosensors are able to simultaneously detect S. typhimurium and offer good sensitivity and reliability of detection.

The anisotropy of antiferromagnetic spin fluctuations has been investigated microscopically in the heavy fermion systems of CeMIn5 and PuMGa5 (M=Co, Rh) by means of nuclear magnetic resonance (NMR). Both systems are known to be relatively high-T c superconductors among the heavy fermion systems, especially PuCoGa5, which has a T c=18.5 K almost one order of magnitude larger than for CeCoIn5 ( T c=2.3 K). Analysis of the Knight shift and spin-lattice relaxation rates suggests XY-type anisotropy in the antiferromagnetic spin fluctuations in the normal states of these unconventional superconductors. Moreover, the 115 superconductors with larger XY-type fluctuations have a higher T c, compared to the anisotropy of spin fluctuations in the related paramagnetic system UFeGa5 and antiferromagnets UPtGa5, NpCoGa5, NpFeGa5.

Backside illuminated CMOS image sensors were developed in order to encompass the pixel area limitation due to metal interconnects. In this technology the fully processed CMOS wafer is bonded to a blank carrier wafer and then back-thinned in order to open the photosensitive sensor area. The process flows of the two main competing wafer bonding technologies used for this manufacturing process (adhesive bonding and low temperature plasma activated direct wafer bonding with polymer layers) will be reviewed.

We have fabricated and characterized ferroelectric-gate TFTs using In-Ga-Zn-O (IGZO) or In2O3 as a channel material. The ferroelectric gate insulator used in this work is (Bi,La)4Ti3O12 (BLT). We observed normal n-channel transistor operation for both IGZO and In2O3-channel TFTs. However, a charge injection type hysteresis was observed for IGZO channel TFTs in drain current – gate voltage (ID-VG) characteristics. Post fabrication anneal at 300oC reduced the charge-injection-tyoe hystereesis and the subthreshold swing was also improved from 0.27 to 0.19 V/decade. On the other hand, when the In2O3 was used as a channel, hysteresis due to the ferroelectric gate insulator was clearly observed in ID-VG characteristics. A memory window of 2V, a subthreshold voltage swing of 0.35V/decade, a field-effect mobility of 1.6 cm2/Vs, and a on/off drain current ratio of more than 10^6 were obtained.

Catalytic wet air oxidation (CWAO) of aqueous solutions of phenol was performed on ruthenium catalysts supported on different oxides: TiO2, ZrO2 and their doped ceria mixtures. Phenol was chosen as a model pollutant molecule because of its wide use in industrial processes. All the samples were found to be highly active for phenol oxidation and the various titania-ceria mixtures were the most efficient for total organic carbon (TOC) removal. ICP analysis of the remaining solution after reaction revealed that ruthenium has not leached. Moreover, elementary analysis of the used catalysts showed that the deposition of carbonaceous species on the surface of the catalysts was rather low and was dependent on the nature of the support.

The dramatic reduction in the thermal conductivity of rough silicon nanowires is due to phonon localization in the wire resulting from multiple scattering of phonons from the rough walls. We report the dependence of thermal conductivity of the nanowires as a function of the surface roughness and the diameter of the wire by modeling the nanowire as a waveguide. In addition, we estimate the impact of boundary condition, dimensionality and cross section of rough wire on the thermal conductivity. This theoretical model gives insights for tailoring thermal conductivity and enhancing the ZT of silicon to 1 for its use in thermoelectrics

We have used small-angle x-ray scattering (SAXS) in conjunction with X-ray diffraction (XRD) to study the nanostructure of hydrogenated nanocrystalline silicon (nc-Si:H). The crystallite size in the growth direction, as deduced from XRD data, is 24 nm with a preferred [220] orientation in the growth direction of the film. Fitting the SAXS intensity shows that the scattering derives from electron density fluctuations of both voids in the amorphous phase and H-rich clusters in the film, probably at the crystallite interfaces. The SAXS results indicate ellipsoidal shaped crystallites about 6 nm in size perpendicular to the growth direction. We annealed the samples, stepwise, and then measured the SAXS and ESR. At temperatures below 350◦C, we observe an overall increase in the size of the scattering centers on annealing but only a small change in the spin density, which suggests that bond reconstruction on the crystallite surfaces takes place with high efficacy.

Soft x-ray scanning transmission x-ray microscope (STXM) spectromicroscopy has been developed and employed to investigate several aspects of actinide chemistry and materials science at the Advanced Light Source Molecular Environmental Science (ALS-MES) Beamline 11.0.2 STXM end station. The basic approach and fundamentals of STXM experiments for radioactive materials systems is discussed. Representative results from STXM spectromicroscopy investigations of a mixed phase uranium nitride, single crystals of Eu(III)[TREN(Me-3,2-HOPO)]3 2H2O and hydrated Pu2(III)(C2O4)3(6H2O) 3H2O complexes are presented. The STXM images and soft x-ray absorption spectra illustrate the capabilities and utility of soft x-ray STXM for providing information about actinide materials, especially the light element constituents. Lastly, new and future opportunities for actinide science utilizing soft x-ray STXM are discussed in light of the planned upgrades for the STXM end stations at the ALS.

Diamond thin films were deposited onto Si (100) substrates using liquid a solution of water and acetone, ethanol, methanol and commercial Tequila as precursors by the Pulsed Liquid Injection Chemical Vapor Deposition (PLICVD) technique. Temperature was varied from 550 °C to 850 °C. In this work we attempted to find a crystal diameter dependence on temperature and pressure from the experimental data. The goal in this work is to found a function that can be adjusted to the experimental data.

In Mexico City, one of the largest cities in the world, large losses occur in the drinking water distribution system, mainly due to the age of the pipes and the type of materials used in water delivery to the end user. In the past, most of the water distribution networks in the city were built with asbestos-cement pipes. Currently, policies dictate that they be replaced by polyethylene pipes. While the size of the city leads to limited financial resources, it is important to prioritize pipe replacement; therefore, a practical approach based on Deterioration Point Allocation (DPA) is proposed to define the priority level. In the next set of factors, each is represented by appropriate indicators:

1. 1. Failures in pipes and service connections

   a. Number of failures (leaks) in pipes repaired in one year for every 100 km of pipeline.

   b. Number of failures (leaks) repaired in one year per 1000 service connections.

   c. Spatial concentration of failures (leaks) in a pipe

   2. Annual pipe and service connections rehabilitation or replacement level per year.

   3. Operating parameters of the network: intermittent water supply, water pressure, and water losses

   4. Deterioration status of pipes and service connections

   5. Land subsidence

A score and a weight are assigned to each factor. The score depends on the values of the indicator, and the weight on the relative importance of the factor. The final score is used to prioritize the replacement and it is calculated by adding up the scores of each factor.

Considering that available information is incomplete and unstructured, two levels of use are proposed: basic (with available data, using MS Excel) and advanced (using a GIS).

Structural materials in the new Generation IV reactors will operate in harsh radiation conditions coupled with high levels of hydrogen and helium production, thus experiencing severe degradation of mechanical properties. The development of structural materials for use in such a hostile environment is predicated on understanding the underlying physical mechanisms responsible for microstructural evolution along with corresponding dimensional instabilities and mechanical property changes. As the phenomena involved are very complex and span in several length scales, a multiscale approach is necessary in order to fully understand the degradation of materials in irradiated environments. The purpose of this work is to study the behavior of Fe systems (namely a-Fe, Fe-Cr and Fe-Ni) under irradiation using both Molecular Dynamics (MD) and Dislocation Dynamics (DD) simulations. Critical information is passed from the atomistic (MD) to the microscopic scale (DD) in order to study the degradation of the material under examination. In particular, information pertaining to the dislocation-defects (such as voids, helium bubbles and prismatic loops) interactions is obtained from MD simulations. Then this information is used by DD to simulate large systems with high dislocation and defect densities.

Various types of chemical doping have been reported as very effective methods to improve the superconducting properties of MgB2 superconductor. Specially, carbon doping via liquid type of carbon-containing compounds have been shown better superconducting properties. In this work, the liquid type of glycerin (C3H8O3) was used as a carbon dopant in MgB2 synthesis. The glycerin was mixed with a liquid media at a different ratio and then pretreated with refined boron powder. Then carbon doped MgB2 superconductor was synthesized through subsequent heat treatment of the pretreated boron powder with magnesium powder. Variation of the amount of carbon dopants and viscosity of the liquid media was correlated with critical current densities and other superconducting properties of MgB2 bulk. The effects of liquid carbon dopants on the superconducting properties also compared with those of solid dopants.

We present a novel experimental platform based on a combined Atomic Force Microscopy (AFM) and Micro-Electrode Array (MEA) set-up. We have used it to measure minimal changes in the morphological/mechanical properties of electrically active cell cultures as well as to measure the changes in the extracellular electrical activity when a single cell is stimulated by means of the AFM tip. In particular, we studied the dynamical changes in cell elasticity of embryonic rat cardiac myocytes along the contraction-relaxation cycle. Applying high load indentations, we also recorded the effects of mechanical stimulations on the cell electrophysiology. The dynamic elastic modulus of the cell related to the contraction-relaxation cycle reveals a temporal behavior that closely follows the changes in cell height. Observed values of dynamic elastic modulus at a maximum indentation depth of 1500nm varied between 8.93 ± 0.78 kPa during systolic (contraction) phase and 4.26 ± 0.47 kPa during diastolic (relaxation) phase. Induced electrophysiological responses were observed when applying loads in the range 40-150 nN. The probability P of recording an induced electrical response (P = 0.16 for a maximum load of 100nN) increased with the maximum applied load. Pulling-like stimulations due to the tip-cell adhesion could also evocate electrical responses.

In this study, we report a method for the formation and characterization of aligned arrays of amorphous titania nanotubes by anodic oxidation in thin titanium films on SiO2 substrates using fluoride-containing electrolytes. Trends in titania nanotube geometries as a function of synthesis conditions were established. A titania nanotube array surface area of approximately 178 m2/g is reported. The titania nanotubes transitioned to the rutile crystal structure when heated in air at 530 °C–705 °C. The degradation of methylene blue under UV light showed that lower fluoride concentrations in the synthesis electrolyte result in higher photocatalytic activity of the titania nanotubes. These results indicate that the synthesis conditions affect the oxygen content of amorphous nanotubes, which determines their physical and chemical properties.

Tin zinc oxide (SnZnO) thin film transistors (TFTs) with different component fraction fabricated by solution process were reported. Sn chloride and Zn acetate were used as precursor and the maximum annealing temperature was 500°C. The electrical characteristics of TFTs were acutely affected by the molar ratio between Sn and Zn in the lattice, and showed the highest mobility and on-to-off ratio of about 17 cm2/Vs and 2×106, respectively. The origins of the high performance were traced through both structural and electrical aspects. Sn was generally considered to offer carrier path by superposition of s orbital, but it was found that the increase of Sn fraction only below specific value in lattice contributed to increase mobility, which could be explained by the structural distortion and the defect generation. Zn atoms introduced in the lattice were necessary to control both mobility and carrier concentration. From these results, the solution-processed SnZnO TFT with high performance was suggested.

The impact of Nd2O3, MoO3 and RuO2 addition on the competition between the crystallization of apatite Ca2Nd8(SiO4)6O2 and powellite CaMoO4 phases which both may appear in High Level Waste nuclear glass (under certain specific conditions of cooling and glass composition) has been studied on a simplified composition belonging to the system SiO2-Na2O-CaO-Al2O3-B2O3. X-ray diffraction (at room temperature and high temperature) and scanning electron microscopy measurements have been performed on five glasses under two different thermal treatments. We show that RuO2 acts as a nucleating agent for apatite. Moreover, neodymium and molybdenum cations seem to be very close in the glassy network as Nd2O3 addition stops the phase separation of molybdates and inhibits the crystallization of CaMoO4. On the contrary, MoO3 seems to favor the crystallization of apatite. For several samples, the evolution of the distribution of Nd3+ cations after crystallization was followed by optical absorption spectroscopy.

Pulsed-laser-deposited ZnO thin films were exposed to a 1.5 MeV helium ion beam to study the changes in radiative and non-radiative recombination. We first measured photoluminescence (PL) spectra at 4.2 K excited with the 325 nm line of a HeCd laser. The as-deposited films showed a donor-bound exciton peak at 3.3567 eV attributed to Zn interstitials. After irradiation the donor-bound-exciton dominated PL spectra shifted to acceptor-bound behaviour with a signal at 3.3519 eV, tentatively attributed to Li or Na acceptors. In contrast to the approximately 30 % decrease of the PL signal near the band edge, we observed a strong concomitant enhancement of the green/orange PL band, located between 2.1 eV and 2.8 eV, by a factor of over 4. Candidates for those transitions are Li impurities and/or O vacancies. For comparison, the steady-state photocurrent decreased strongly in the irradiated region, which can also be attributed to increased non-radiative recombination through oxygen-related defects.

Silicon Carbide (SiC) Metal-Oxide-Semiconductor (MOS) capacitors, having different nitridation times, were characterized by means of Constant Capacitance Deep Level Transient Spectroscopy (CCDLTS). Electron emission was investigated with respect to the temperature dependence of emission rates and the amplitude of the signal as a function of the filling voltage. The comparison between the emission activation energies of the dominant CCDLTS peaks and the filling voltages, led to the conclusion that the dominant trapping behavior originates in the Silicon-dioxide (SiO2) layer. Moreover, a model of electron capture via tunneling can explain the dependence of the CCDLTS signal on increasing filling voltage.

Rapid development in the area of low-temperature fuel cells has led to increased attention on catalyst synthesis with cost effective and environmentally-benign technology (green chemistry). In this study, a highly dispersed palladium nanoparticle catalyst was successfully prepared on a bacterial cell support by a single-step, room-temperature microbial method without dispersing agents. The metal ion reducing bacterium Shewanella oneidensis were able to reduce palladium ions into insoluble palladium at room temperature when formate was provided as the electron donor. The prepared biomass-supported palladium nanoparticles were characterized for their catalytic activity as anodes in polymer electric membrane fuel cell for power production. The maximum power generation of the biomass-supported palladium catalyst was up to 90% of that of a commercial palladium catalyst.