The modified TiO2 nanoparticles were incorporated into the Bulk heterojunction system of P3HT:PCBM to improve the performance of P3HT:PCBM bulk heterojunction organic solar cells. The organically-modified TiO2 nanoparticle compounds were synthesized in aqueous media at room temperature. These TiO2 compounds in various solution concentrations were deposited on the top of the P3HT:PCBM active layer by spin coating. The performance of organic solar cells was carefully investigated in the respect of the scattering and the localized surface plasmon resonance (LSPR) that couple strongly to the incident light. In addition to the device, P3HT:PCBM solar cells with the use of the TiO2 nanoparticles, enhanced Fill Factor (FF) due mainly to improved shunt resistance (Rsh). The TiO2 plays a critical role in improving the interface between P3HT:PCBM active layer and Al electrode.

SnO2-based varistors are strong candidates to replace the ZnO-based varistors due to ordering fewer additives to improve its electrical behavior as well as by showing similar nonlinear characteristics of ZnO varistors. In this work, SnO2-nanoparticles based-varistors with addition of 1.0 %mol of ZnO and 0.05 %mol of Nb2O5 were synthesized by chemical route. SnO2.ZnO.Nb2O5-films with 5 μm of thickness were obtained by electrophoretic deposition (EPD) of the nanoparticles on Si/Pt substrate from alcoholic suspension of SnO2-based powder. The sintering step was carried out in a microwave oven at 1000 °C for 40 minutes. Then, Cr3+ ions were deposited on the films surface by EPD after the sintering step. Each sample was submitted to different thermal treatments to improve the varistor behavior by diffusion of ions in the samples. The films showed a nonlinear coefficient (α) greater than 9, breakdown voltage (VR) around 60 V, low leakage current (IF ≈ 10-6 A), height potential barrier above 0.5 eV and grain boundary resistivity upward of 107 Ω.cm.

The measurement of precise submicron displacements is essential in several MEMS applications. For instance, the measurement of the mechanical parameters of biological cells requires repeatable measurement of displacements in the nanometer regime. This paper presents a method to make displacement measurements in an aqueous MEMS environment with a ± 10 nm accuracy by using the blue channel of RGB pictures in combination with a FFT phase shift analysis.

AFM induced local anodic oxidation of HOPG was carried out in various conditions such as humidity, applied voltage and scan speed. A clear evidence of different oxidation features between HOPG and graphene has been confirmed and discussed.

These results should contribute to the progress of the micro/nano fabrication of graphene by the local anodic oxidation.

We present here performance of Li ion batteries with SiC nanoparticle-film anode, which is fabricated by a double multi-hollow discharge plasma chemical vapor deposition (CVD) method. The first cycle of charge/discharge property of the Li ion battery with the SiC nanoparticle-film anode shows a high capacity of over 4,000 mAh/g, which is 12 times higher than the Li ion battery with the conventional graphite anode. The discharge capacity shows high stability for first 10th cycle, and is 3750 mAh/g for the 10th cycle.

Breast cancer metastasis to bone continues to be a major clinical problem, and patient-to-patient variability in rates of disease progression and metastasis complicate treatment even further. This may be due to differences in the cancer cells, the osteoclasts, or the pre-metastatic niche, but all of these contribute to proteolytic remodeling necessary for osteolytic lesion establishment, primarily through secretion of cathepsin K, the most powerful human collagenase. There is debate about the relative contributions of breast cancer cells and osteoclasts and synergism between the two in altering the biochemical and biomechanical properties of the colonized bone, as these are difficult to parse with animal models. To quantify the relative contributions of breast cancer cells and osteoclasts in bone resorption, we have been developing engineered bone microenvironment tissue surrogates by adapting a poly(ester urethane) urea system embedded with microbone particles. Here, we report their use with MDA-MB-231 breast cancer cells and RAW264.7 derived osteoclasts, to provide temporal, multiscale reporters of bone resorption that can be measured non-destructively: 1) collagen degradation measured by C-terminal collagen fragment release, 2) mineral dissolution by measuring calcium released with the calcium arsenazo assay, and also show their beneficial effects in upregulating cathepsin K expression compared to tissue culture polystyrene controls. These more natural derived bone surrogates may be useful tools in mimicking bone metastatic niche and determining differences between proteolytic activity of different patients’ tumor and bone resident cells in a controlled manner.

Bismuth selenide (BixSey) films are deposited onto glass substrate using chemical bath deposition at room temperature. The reacting bath contained bismuth nitrate, triethanolamine and sodium selenosulfate as selenium (Se) source. Ammonium hydroxide is used to adjust the pH of the bath. The films deposited in solutions containing Se source solution of 10 ml and 15 ml are characterized by surface morphological, compositional and structural, properties. The optimum deposition time is about 3 hours for both solutions. Films deposited up to 24 hours in bath with 10 ml Se source solution had thickness ranging up to 232 nm. The deposition rate is found to increase up to 61 nm/h for 3-hour deposition. In the case of bath with 15 ml Se source solution, the film thickness ranged from 45 nm to 632 nm for 1-hour to 24-hour deposition, respectively; with a deposition rate increasing up to 123 nm/h for 3-hour deposition. Film roughness of about 6.6 nm to 22.8 nm is measured by atomic force microscope for films deposited in bath containing 10 mL Se source and 15 ml of Se source, respectively. Crack free layers are observed with randomly large plate-like particles on top of the layer for some films. The films with typical composition of Bi21.8Se78.2 are found to be rich in Se when deposited for 6 hours, whereas the composition of a film deposited in the same bath (10 mL Se source) for 3 hours is found at Bi60.3Se39.6. Additionally, structural analysis performed by x-ray diffraction (XRD) did not reveal well-defined XRD patterns, which indicates that BixSey films were constituted mostly of nanocrystalline grains.

We present a computational density functional theory study of UF6 adsorption on ideal as well as hydrogenated and fluorinated graphene. We show that (i) the isotopic splitting in the vibrational spectrum of UF6 observed in vacuum is largely preserved in the adsorbed molecules. The existence of several adsorption configurations with competing E ads leads to overlaps in the vibrational spectra of isotopomers, but isotopomer-unique modes exist on all three surfaces. (ii) The adsorption energy of UF6 is of the order of 1.2 eV on ideal graphene, 1 eV on graphane, and 0.1 eV on fluorographene, i.e. the adsorption strength is moderate and can be controlled by surface modification. (i) and (ii) mean that it may be possible to cause desorption of a selected isotopomer by laser radiation, leading to isotopic separation between the surface and the gas.

This paper reports on the effect of surface functionalization of multi-wall carbon nanotubes on the strength and structure of portland cement composites. Reference nanotubes and nanotubes functionalized by carboxylic groups are used in this research.

Grafting of functional groups on the surface of the nanotubes allows the acceleration of cement hydration. It is established that the use of carboxylated nanotubes contributed to early strength development. The multi-wall carbon nanotubes reinforced composites are characterized by the high content of the calcium silicate hydrates and a very dense structure.

If a photovoltaic (PV) technology is assessed today in a technical framework, then efficiency is the most commonly addressed parameter, followed by service lifetime. Cost, as the third parameter of the "magic triangle", is even less often reported. However, if a new technology is prepared to enter a market, other important parameters have to be considered, especially if non-standard PV applications are targeted.

Organic photovoltaic (OPV) is a well known but young PV technology of the so called third generation, which offers unique advantages for integrated products such as building integrated photovoltaics (BIPV). In this contribution we would like to highlight some of the advantages and challenges which are specific to the application of OPV in the field of building integration. Architectural design features of OPV include the ability to adapt semi-transparency, color and shape of the module. Moreover, glass-laminated OPV modules are deemed suitable for BIPV because of their ease of integration, good fire resistance, high energy harvest per nominal watt-peak and long lifetimes.

Carbon fiber-reinforced epoxy composites (CFEC) were fabricated infusing 0, 0.15, 0.30, and 0.40 wt% amino-functionalized XD-grade carbon nanotubes (NH2-XDCNTs) using the compression molding process under 16 kips. The thermo-mechanical and interlaminar shear properties of CNT incorporated carbon/epoxy composite samples were evaluated by performing dynamic-mechanical thermal analysis (DMTA) and short beam shear (SBS) tests. XD-CNTs were infused into Epon 862 resin using a mechanical stirrer followed by a high intensity ultrasonic liquid processor for better dispersion. After the sonication, the mixture was placed in a three roll milling processor for 3 successive cycles at 140 rpm, with the gap spaces incrementally reduced from 20 to 5 μm, to obtain the uniform dispersion of CNTs throughout the resin. Epikure W curing agent was then added to the modified resin and mixed using a high-speed mechanical stirrer. Finally, the fiber was reinforced with that modified resin using the compression molding process. The results obtained from the DMTA test were analyzed based on the storage modulus, glass transition temperature, and loss modulus. The analysis indicated that the thermo-mechanical properties were linearly increasing from 0 to 0.3 wt% XDCNT loading. The SBS test results exhibited that the incorporation of XDCNTs into the composite increased the interlaminar shear strength (ILSS) by up to 22% at 0.3 wt% CNT loading. Better dispersion of XDCNTs might be attributed to more crosslinking sites and better interaction between fiber and matrix resulting in an improved fiber-matrix interface, whereas, the reaction between functional groups –NH2 of XDCNTs with epoxide groups of resin and epoxy silanes of fiber surfaces improved the crosslinking and thereby ILSS properties of carbon/epoxy composites.

The oxidation of CO to CO2 is necessary in the operation of Proton Exchange Membrane Fuel Cells (PEMFCs) since even a small amount of CO that is formed when the PEMFC is operated under ambient conditions is sufficient to poison the Pt catalyst in the electrodes and degrade the performance. Operation using higher loads of Pt catalysts or increasing the purity of the H2 input gas significantly adds to the cost, adversely impacting the commercial development of PEMFCs. We combined graphene oxide (GO) with metallic salts and partially reduced the mixture with sodium borohydride, yielding a metallized form of partially reduced graphene oxide (prGO) platelets that remained in solution. When these platelets were coated on the Nafion membrane of a PEMFC, a 72% increase in the power output was observed, whereas a 62% increase was observed when the membrane was coated with partially reduced graphene oxide without the metallic salts. Results will be presented for AuGO/prGO, PtGO/prGO, and AuPtGO/prGO combinations.

Here we introduce a facile method to fabricate a flexible piezoelectric sensor using one-dimensional (1-D) piezoelectric poly(vinylidene fluoride) (PVDF) nanofibers directly produced onto flexible printed electrodes by electro-spinning without an additional poling process. The flexible silver electrodes are fabricated on polyethylene terephthalate (PET) using silver nanowires by easy and cost-effective spraying deposition. The electrospun PVDF nanofibers have uniaxially aligned arrays on the electrodes by using a rotating collector. The fabricated PVDF piezoelectric sensors demonstrate the piezoelectric responses with repeated mechanical stimuli with good flexibility and high sensitivity. We expect that the facile fabrication of PVDF piezoelectric sensors on flexible printed electrodes can be usefully exploited to integrate the piezoelectric sensors into flexible and stretchable functional electronic devices.

We studied the effect of a cross-conjugated bridging group (χC) on charge-transfer in a push-pull chromophore system. The hyperpolarizability of such molecules was found to be comparable to that of a fully π-conjugated molecule (πC) with the same donor and acceptor. The cross-conjugated moiety was then applied as a pendant to a fully π-conjugated chromophore containing a tricyanopyrroline acceptor (TCP). The addition of a χC moiety did not alter the intrinsic hyperpolarizability and provides an avenue for extending and aiding πC systems. The molecules were examined by X-ray diffraction (XRD), hyper-Raleigh scattering (HRS) and UV-visible (UV-vis) spectroscopy. Experimental results were compared with the predictions of density functional theory (DFT). Cross-conjugated molecules have comparable β values, relative to πC molecules, due to reduced spatial overlap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Thus, the χC architecture could facilitate independent modification of donor and acceptor strengths while minimizing unfavorable effects on electronic transitions and dipole moments.

Laser heating and annealing of hydrogenated amorphous silicon (a-Si:H) films is of interest for improved material properties. Due to the variety of possible laser treatments with regard to wavelength, pulse duration, scan time etc., the definition of laser impact on the material is a challenge which we try to approach by comparing properties of laser and oven treated materials. Here we report on the effect of oven heat treatment (up to TA= 575°C) on microstructure and hydrogen content of hydrogenated amorphous silicon films, as detected by measurements of infrared absorption and of effusion of hydrogen as well as of implanted helium. The latter technique has been found to measure isolated voids (cavities) of the size of silicon divacancies and larger. Undoped as well as phosphorus and boron doped plasma-deposited a-Si:H films of various hydrogen content (< 15 at.%) were investigated, including undoped device grade a-Si:H. The results show little indication for void-related microstructure in the as-deposited and annealed state for material with a concentration of silicon bonded hydrogen below 5 at. %. At higher hydrogen concentration, evidence is found that hydrogen out-diffusion due to annealing causes isolated voids in concentrations up to about 1020 cm-3. A possible mechanism for the annealing induced (micro-)void generation is discussed.

The problems of using performance parameters such as voltage, current and temperature measured with electrical sensors in today’s battery management systems (BMS) are well known. These parameters can be weakly informative about cell state, particularly as cells age, and contribute to over-conservative utilization and oversizing of a battery pack. Fiber optic (FO) sensors can offer an interesting alternative to conventional electrical sensors, with several advantages such as high selective sensitivity to various parameters, light weight, robustness to EMI, and multiplexing capabilities. In this study, a particular type of FO sensors, fiber Bragg grating (FBG) sensors were externally attached to lithium ion pouch cells for monitoring additional informative cell parameter such as strain and temperature. Multiple charge and discharge cycle were performed to examine the qualification of these signals for cell state estimation in BMS. In comparison to corresponding measurements using conventional electrical sensors, the FBG signals showed very promising results for utilization in effective BMS.

High-κ and metal gate structures have been used to improve the performance of CMOS devices. By changing the materials and structures of the gate dielectric stacks, the flatband voltage (VFB) and the leakage can be changed. We used bilayers and multilayer structures composed of MgO and Al2O3 to verify their influence on the overall electrical properties. Films with an MgO bottom layer generally are found with less flatband voltage shift and lower leakage than with an Al2O3 bottom layer. Also, the frequency dispersion and the interface state density (Dit) are higher for those with MgO bottom layers. MgO films thicker than 0.5 nm effectively shields the positive charges present in the Al2O3.

Mn-doped CeO2 electrolytes formulated as Ce1-xMnxO2-x (0.05 ≤ x ≤ 0.25) were prepared via soft chemical technique which involved co-precipitation of Mn2+ and Ce4+ using oxalic acid as the precipitant. The optimized pH for a stable incorporation of Mn dopant into ceria was found to be pH = 10. The solubility limit of MnO in the CeO2 fluorite lattice structure was suggested to be x = 0.20. The phase composition, morphology properties and elemental analysis of the oxalate and derived-powder was characterized using X-ray diffraction, SEM and X-ray fluorescence (XRF) respectively. The electrical conductivity of sintered samples of Mn-doped CeO2 ceramics were investigated in air using AC impedance spectroscopy. The bulk conductivities of the Mn-doped CeO2 ceramics sintered at 1200 °C at a test temperature of 800 °C were determined to be 4.223 x 10-4 ohm-1 cm-1 for Mn content x = 0.10 with activation energy, Ea = 0.88 eV.

The carbon-14 generated in Zircaloy (Zry) hull waste is considered an important radionuclide in the TRU waste geological disposal concept in Japan. Given that the metal Zry is highly corrosion-resistant in the anaerobic and low-temperature conditions of the repository, and that the C-14 release rate is assumed to be controlled by the corrosion rate, a variety of corrosion and leaching tests have been performed. However, since the Zry corrosion rate is extremely slow, it is not possible to predict long-term corrosion behavior through low-temperature corrosion tests conducted in a reasonable time period. A vast amount of testing has been conducted in the higher-temperature range of 523 to 633 K, and corrosion correlations have been obtained from these tests. Corrosion correlations have been used to predict the corrosion rate of Zry in a tuff repository. Long-term Zry autoclave corrosion data have been analyzed to develop new corrosion correlations. Extrapolating these correlations to a lower temperature range requires verification that the mechanisms do not change over the range of testing and extrapolation. Factors that influence corrosion rates under geological disposal conditions, such as material and environmental factors, should also be examined. Corrosion correlations, factors influencing corrosion rates, the results of corrosion and leaching tests, and a preliminary evaluation are discussed.

The front surface of dielectric passivated silicon wafers were spray coated with polyacrylic acid (PAA) using an ultrasonic coating system. A simple model was proposed to correlate the degree of coverage with the number of spray passes. The sprayed PAA films enabled good etching of the dielectric, using a process referred to as aerosol jet etching (AJE), despite the fact that the PAA thickness was non-uniform over the substrate. The AJE tip-to-substrate distance and diameter of the tip were tuned to balance process throughput and the etched line width. Controlling the level of condensation in the aerosol jet printer (AJP) fluid path was critical for etching 156-mm pseudo square silicon wafers.