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Sample records for hybrid nano resonators

  1. Functional Hybrid Nano-Oxides

    Science.gov (United States)

    2015-10-26

    ABSTRACT This project was dedicated to investigate and engineer novel properties of oxide based materials , nanostructures and devices with properties that...mechanism for the metal-insulator transition and it also opens up the possibility for the preparation of unique nanostructured materials . A second major...spare time since the funding ended before. Development of novel synthesis and characterization methods in area of Nano-Oxides paved the way to

  2. Hybrid plasmonic-photonic resonators (Conference Presentation)

    Science.gov (United States)

    Koenderink, A. Femius; Doeleman, Hugo M.; Ruesink, Freek; Verhagen, Ewold; Osorio, Clara I.

    2016-09-01

    Hybrid nanophotonic structures are structures that integrate different nanoscale platforms to harness light-matter interaction. We propose that combinations of plasmonic antennas inside modest-Q dielectric cavities can lead to very high Purcell factors, yielding plasmonic mode volumes at essentially cavity quality factors. The underlying physics is subtle: for instance, how plasmon antennas with large cross sections spoil or improve cavities and vice versa, contains physics beyond perturbation theory, depending on interplays of back-action, and interferences. This is evident from the fact that the local density of states of hybrid systems shows the rich physics of Fano interferences. I will discuss recent scattering experiments performed on toroidal microcavities coupled to plasmon particle arrays that probe both cavity resonance shifts and particle polarizability changes illustrating these insights. Furthermore I will present our efforts to probe single plasmon antennas coupled to emitters and complex environments using scatterometry. An integral part of this approach is the recently developed measurement method of `k-space polarimetry', a microscopy technique to completely classify the intensity and polarization state of light radiated by a single nano-object into any emission direction that is based on back focal plane imaging and Stokes polarimetry. I show benchmarks of this technique for the cases of scattering, fluorescence, and cathodoluminescence applied to directional surface plasmon polariton antennas.

  3. Characterization and Curing Kinetics of Epoxy/Silica Nano-Hybrids

    Directory of Open Access Journals (Sweden)

    Cheng-Fu Yang

    2015-10-01

    Full Text Available The sol-gel technique was used to prepare epoxy/silica nano-hybrids. The thermal characteristics, curing kinetics and structure of epoxy/silica nano-hybrids were studied using differential scanning calorimetry (DSC, 29Si nuclear magnetic resonance (NMR and transmission electron microscopy (TEM. To improve the compatibility between the organic and inorganic phases, a coupling agent was used to modify the diglycidyl ether of bisphenol A (DGEBA epoxy. The sol-gel technique enables the silica to be successfully incorporated into the network of the hybrids, increasing the thermal stability and improving the mechanical properties of the prepared epoxy/silica nano-hybrids. An autocatalytic mechanism of the epoxy/SiO2 nanocomposites was observed. The low reaction rate of epoxy in the nanocomposites is caused by the steric hindrance in the network of hybrids that arises from the consuming of epoxide group in the network of hybrids by the silica. In the nanocomposites, the nano-scale silica particles had an average size of approximately 35 nm, and the particles were well dispersed in the epoxy matrix, according to the TEM images.

  4. Characterization and Curing Kinetics of Epoxy/Silica Nano-Hybrids

    Science.gov (United States)

    Yang, Cheng-Fu; Wang, Li-Fen; Wu, Song-Mao; Su, Chean-Cheng

    2015-01-01

    The sol-gel technique was used to prepare epoxy/silica nano-hybrids. The thermal characteristics, curing kinetics and structure of epoxy/silica nano-hybrids were studied using differential scanning calorimetry (DSC), 29Si nuclear magnetic resonance (NMR) and transmission electron microscopy (TEM). To improve the compatibility between the organic and inorganic phases, a coupling agent was used to modify the diglycidyl ether of bisphenol A (DGEBA) epoxy. The sol-gel technique enables the silica to be successfully incorporated into the network of the hybrids, increasing the thermal stability and improving the mechanical properties of the prepared epoxy/silica nano-hybrids. An autocatalytic mechanism of the epoxy/SiO2 nanocomposites was observed. The low reaction rate of epoxy in the nanocomposites is caused by the steric hindrance in the network of hybrids that arises from the consuming of epoxide group in the network of hybrids by the silica. In the nanocomposites, the nano-scale silica particles had an average size of approximately 35 nm, and the particles were well dispersed in the epoxy matrix, according to the TEM images. PMID:28793616

  5. Nano and hybrid aluminum based metal matrix composites: an overview

    Directory of Open Access Journals (Sweden)

    Muley Aniruddha V.

    2015-01-01

    Full Text Available Aluminium matrix composites (AMCs are potential light weight engineering materials with excellent properties. AMCs find application in many areas including automobile, mining, aerospace and defence, etc. Due to technological advancements, it is possible to use nano sized reinforcement in Al matrix. Nano sized reinforcements enhance the properties of Al matrix compared to micro sized reinforcements. Hybrid reinforcement imbibe superior properties to aluminium matrix composites as compared with Al composites having single reinforcement. This paper is focused on overview of development in the field of Al based metal matrix with nano and hybrid aluminium based composites.

  6. Hyperbolic Metamaterial Nano-Resonators Make Poor Single Photon Sources

    CERN Document Server

    Axelrod, Simon; Wong, Herman M K; Helmy, Amr S; Hughes, Stephen

    2016-01-01

    We study the optical properties of quantum dipole emitters coupled to hyperbolic metamaterial nano-resonators using a semi-analytical quasinormal mode approach. We show that coupling to metamaterial nano-resonators can lead to significant Purcell enhancements that are nearly an order of magnitude larger than those of plasmonic resonators with comparable geometry. However, the associated single photon output $\\beta$-factors are extremely low (around 10%), far smaller than those of comparable sized metallic resonators (70%). Using a quasinormal mode expansion of the photon Green function, we describe how the low $\\beta$-factors are due to increased Ohmic quenching arising from redshifted resonances, larger quality factors and stronger confinement of light within the metal. In contrast to current wisdom, these results suggest that hyperbolic metamaterial nano-structures make poor choices for single photon sources.

  7. Observation of a Hybrid Spin Resonance

    Science.gov (United States)

    Bai, M.; Allgower, C.; Ahrens, L.; Alessi, J.; Brown, K.; Bunce, G.; Cameron, P.; Chu, C. M.; Courant, E. D.; Glenn, J. W.; Huang, H.; Jeon, D.; Kponou, A. E.; Krueger, K.; Luccio, A.; Makdisi, Y. I.; Lee, S. Y.; Ratner, L.; Reece, K.; Roser, T.; Spinka, H.; Syphers, M. J.; Tsoupas, N.; Underwood, D. G.; van Asselt, W.; Williams, N.; Yokosawa, A.

    2000-02-01

    A new type of spin depolarization resonance has been observed at the Brookhaven Alternating Gradient Synchrotron (AGS). This spin resonance is identified as a strong closed-orbit sideband around the dominant intrinsic spin resonance. The strength of the resonance was proportional to the 9th harmonic component of the horizontal closed orbit and proportional to the vertical betatron oscillation amplitude. This ``hybrid'' spin resonance cannot be overcome by the partial snake at the AGS, but it can be corrected by the harmonic orbit correctors.

  8. Development of 3d micro-nano hybrid patterns using anodized aluminum and micro-indentation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hong Gue; Kwon, Jong Tae [Division of Mechanical Engineering and Mechatronics, Kangwon National University, 1 Kangwondaehakgil, Chunchon, Gangwon-do, 200-701 (Korea, Republic of); Seo, Young Ho [Division of Mechanical Engineering and Mechatronics, Kangwon National University, 1 Kangwondaehakgil, Chunchon, Gangwon-do, 200-701 (Korea, Republic of)], E-mail: mems@kangwon.ac.kr; Kim, Byeong Hee [Division of Mechanical Engineering and Mechatronics, Kangwon National University, 1 Kangwondaehakgil, Chunchon, Gangwon-do, 200-701 (Korea, Republic of)

    2008-07-31

    We developed a simple and cost-effective method of fabricating 3D micro-nano hybrid patterns in which micro-indentation is applied on the anodized aluminum substrate. Nano-patterns were formed first on the aluminum substrate, and then micro-patterns were fabricated by deforming the nano-patterned aluminum substrate. Hemispherical nano-patterns with a 150 nm-diameter on an aluminum substrate were fabricated by anodizing and alumina removing process. Then, micro-pyramid patterns with a side-length of 50 {mu}m were formed on the nano-patterns using micro-indentation. To verify 3D micro-nano hybrid patterns, we replicated 3D micro-nano hybrid patterns by a hot-embossing process. 3D micro-nano hybrid patterns may be used in nano-photonic devices and nano-biochips applications.

  9. Superconducting qubit-resonator-atom hybrid system

    Science.gov (United States)

    Yu, Deshui; Kwek, Leong Chuan; Amico, Luigi; Dumke, Rainer

    2017-09-01

    We propose a hybrid quantum system where an LC resonator inductively interacts with a flux qubit and is capacitively coupled to a Rydberg atom. Varying the external magnetic flux bias controls the flux qubit flipping and the flux qubit-resonator interface. The atomic spectrum is tuned via an electrostatic field, manipulating the qubit-state transition of atom and the atom-resonator coupling. Different types of entanglement of superconducting, photonic and atomic qubits can be prepared via simply tuning the flux bias and electrostatic field, leading to the implementation of three-qubit Toffoli logic gate.

  10. Controlling the Morphology of Nano-Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Abdullah I.A. Jaafari

    2010-01-01

    Full Text Available Problem statement: It is known that layer double hydroxide is one of the nano ordered layered compounds and possesses plate-like morphology if carefully crystallized. Approach: In this study, Co-Sn LDH consisting of divalent and tetravalent cations was prepared with new morphology. XRD patterns of the prepared Co-Sn LDH showed that the interlayer spacing of the LDH was 0.78 nm and SEM image showed nano-needles structure. Results: By intercalation reaction with monocarboxylic acids at room temperature, XRD patterns indicated that the interlayered spacing increased to 3-4.8 nm and formed organic-inorganic nano-hybrid materials. Also, SEM images showed that the nano-needles structure of Co-Sn LDH changes to plate like-structure. Conclusion: Thermal analyses (TG, DTG and DTA and Infrared spectrum confirmed the intercalation processes of n-capric acid and n-stearic acid inside Co-Sn LDH and the formation of nano-hybrid materials.

  11. Hybridized Nano-Structure Composed of Metal and Polydiacetylene

    Institute of Scientific and Technical Information of China (English)

    H. Oikawa; A. Masuhara; T. Onodera; H. Kasai; H. Nakanishi

    2005-01-01

    @@ 1Introduction Polydiacetylene (PDA) is one of the promising candidates for organic third-order nonlinear optical (NLO) material, due to fast optical responsibility and easy processability in comparison with semiconductors etc. The magnitude of NLO property, however, is not still sufficient for the devices applications. Neeves, et al[1] theoretically predicted the enhancement of NLO property for core-shell type hybridized nanocrystal (NC) composed of PDA and metal. In the present study, we have prepared the two kinds of core-shell type hybridized nano-structure, and investigated their optical properties.

  12. Nano-optomechanical resonators in microfluidics

    CERN Document Server

    Fong, King Yan; Tang, Hong X

    2015-01-01

    Operation of nanomechanical devices in water environment has been challenging due to the strong viscous damping that greatly impedes the mechanical motion. Here we demonstrate an optomechanical micro-wheel resonator integrated in microfluidic system that supports low-loss optical resonances at near-visible wavelength with quality factor up to 1.5 million. The device can be operated in self-oscillation mode in air with low threshold power of 45 uW. The very high optical Q allows the observation of the thermal Brownian motion of the mechanical mode in both air and water environment with high signal-to-background ratio. A numerical model is developed to calculate the hydrodynamic effect on the device due to the surrounding water, which agrees well with the experimental results. With its very high resonance frequency (170 MHz) and small loaded mass (75 pg), the present device is estimated to have mass sensitivity of attogram level in liquid environment with bandwidth of 1 Hz.

  13. Nanostructures Exploit Hybrid-Polariton Resonances

    Science.gov (United States)

    Anderson, Mark

    2008-01-01

    Nanostructured devices that exploit the hybrid-polariton resonances arising from coupling among photons, phonons, and plasmons are subjects of research directed toward the development of infrared-spectroscopic sensors for measuring extremely small quantities of molecules of interest. The spectroscopic techniques in question are surface enhanced Raman scattering (SERS) and surface enhanced infrared absorption (SEIRA). An important intermediate goal of this research is to increase the sensitivity achievable by these techniques. The basic idea of the approach being followed in this research is to engineer nanostructured devices and thereby engineer their hybrid-polariton resonances to concentrate infrared radiation incident upon their surfaces in such a manner as to increase the absorption of the radiation for SEIRA and measure the frequency shifts of surface vibrational modes. The underlying hybrid-polariton-resonance concept is best described by reference to experimental devices that have been built and tested to demonstrate the concept. The nanostructure of each such device includes a matrix of silicon carbide particles of approximately 1 micron in diameter that are supported on a potassium bromide (KBr) or poly(tetrafluoroethylene) [PTFE] window. These grains are sputter-coated with gold grains of 40-nm size (see figure). From the perspective of classical electrodynamics, in this nanostructure, that includes a particulate or otherwise rough surface, the electric-field portion of an incident electromagnetic field becomes concentrated on the particles when optical resonance conditions are met. Going beyond the perspective of classical electrodynamics, it can be seen that when the resonance frequencies of surface phonons and surface plasmons overlap, the coupling of the resonances gives rise to an enhanced radiation-absorption or -scattering mechanism. The sizes, shapes, and aggregation of the particles determine the frequencies of the resonances. Hence, the task of

  14. Nano Sensing and Energy Conversion Using Surface Plasmon Resonance (SPR

    Directory of Open Access Journals (Sweden)

    Iltai (Isaac Kim

    2015-07-01

    Full Text Available Nanophotonic technique has been attracting much attention in applications of nano-bio-chemical sensing and energy conversion of solar energy harvesting and enhanced energy transfer. One approach for nano-bio-chemical sensing is surface plasmon resonance (SPR imaging, which can detect the material properties, such as density, ion concentration, temperature, and effective refractive index in high sensitivity, label-free, and real-time under ambient conditions. Recent study shows that SPR can successfully detect the concentration variation of nanofluids during evaporation-induced self-assembly process. Spoof surface plasmon resonance based on multilayer metallo-dielectric hyperbolic metamaterials demonstrate SPR dispersion control, which can be combined with SPR imaging, to characterize high refractive index materials because of its exotic optical properties. Furthermore, nano-biophotonics could enable innovative energy conversion such as the increase of absorption and emission efficiency and the perfect absorption. Localized SPR using metal nanoparticles show highly enhanced absorption in solar energy harvesting. Three-dimensional hyperbolic metamaterial cavity nanostructure shows enhanced spontaneous emission. Recently ultrathin film perfect absorber is demonstrated with the film thickness is as low as ~1/50th of the operating wavelength using epsilon-near-zero (ENZ phenomena at the wavelength close to SPR. It is expected to provide a breakthrough in sensing and energy conversion applications using the exotic optical properties based on the nanophotonic technique.

  15. Highly sensitive electrochemical impedance spectroscopic detection of DNA hybridization based on Au(nano)-CNT/PAN(nano) films.

    Science.gov (United States)

    Zhou, Na; Yang, Tao; Jiang, Chen; Du, Meng; Jiao, Kui

    2009-01-15

    A polyaniline nanofibers (PAN(nano))/carbon paste electrode (CPE) was prepared via dopping PAN(nano) in the carbon paste. The nanogold (Au(nano)) and carbon nanotubes (CNT) composite nanoparticles were bound on the surface of the PAN(nano)/CPE. The immobilization and hybridization of the DNA probe on the Au(nano)-CNT/PAN(nano) films were investigated with differential pulse voltammetry (DPV) and cyclic voltammetry (CV) using methylene blue (MB) as indicator, and electrochemical impedance spectroscopy (EIS) using [Fe(CN)(6)](3-/4-) as redox probe. The voltammetric peak currents of MB increased dramatically owing to the immobilization of the probe DNA on the Au(nano)-CNT/PAN(nano) films, and then decreased obviously owing to the hybridization of the DNA probe with the complementary single-stranded DNA (cDNA). The electron transfer resistance (R(et)) of the electrode surface increased after the immobilization of the probe DNA on the Au(nano)-CNT/PAN(nano) films and rose further after the hybridization of the probe DNA. The remarkable difference between the R(et) value at the DNA-immobilized electrode and that at the hybridized electrode could be used for the label-free EIS detection of the target DNA. The loading of the DNA probe on Au(nano)-CNT/PAN(nano) films was greatly enhanced and the sensitivity for the target DNA detection was markedly improved. The sequence-specific DNA of phosphinothricin acetyltransferase (PAT) gene and the polymerase chain reaction (PCR) amplification of nopaline synthase (NOS) gene from transgenically modified beans were determined with this label-free EIS DNA detection method. The dynamic range for detecting the PAT gene sequence was from 1.0 x 10(-12)mol/L to 1.0 x 10(-6)mol/L with a detection limit of 5.6 x 10(-13)mol/L.

  16. High frequency nano-optomechanical disk resonators in liquids

    CERN Document Server

    Gil-Santos, E; Nguyen, D T; Hease, W; Lemaître, A; Ducci, S; Leo, G; Favero, I

    2015-01-01

    Vibrating nano- and micromechanical resonators have been the subject of research aiming at ultrasensitive mass sensors for mass spectrometry, chemical analysis and biomedical diagnosis. Unfortunately, their merits diminish dramatically in liquids due to dissipative mechanisms like viscosity and acoustic losses. A push towards faster and lighter miniaturized nanodevices would enable improved performances, provided dissipation was controlled and novel techniques were available to efficiently drive and read-out their minute displacement. Here we report on a nano-optomechanical approach to this problem using miniature semiconductor disks. These devices combine mechanical motion at high frequency above the GHz, ultra-low mass of a few picograms, and moderate dissipation in liquids. We show that high-sensitivity optical measurements allow to direct resolve their thermally driven Brownian vibrations, even in the most dissipative liquids. Thanks to this novel technique, we experimentally, numerically and analytically...

  17. Hybrid plasmon photonic crystal resonance grating for integrated spectrometer biosensor.

    Science.gov (United States)

    Guo, Hong; Guo, Junpeng

    2015-01-15

    Using nanofabricated hybrid metal-dielectric nanohole array photonic crystal gratings, a hybrid plasmonic optical resonance spectrometer biosensor is demonstrated. The new spectrometer sensor technique measures plasmonic optical resonance from the first-order diffraction rather than via the traditional method of measuring optical resonance from transmission. The resonance spectra measured with the new spectrometer technique are compared with the spectra measured using a commercial optical spectrometer. It is shown that the new optical resonance spectrometer can be used to measure plasmonic optical resonance that otherwise cannot be measured with a regular optical spectrometer.

  18. Thermal properties of oil palm nano filler/kenaf reinforced epoxy hybrid nanocomposites

    Science.gov (United States)

    Saba, N.; Paridah, M. T.; Abdan, K.; Ibrahim, N. A.

    2016-11-01

    The aim of this research study was to fabricate nano oil palm empty fruit bunch (OPEFB)/kenaf/epoxy hybrid nanocomposites and to make comparative study on the thermal properties of nano OPEFB/kenaf/epoxy hybrid nanocomposites with the montmorillonite (MMT)/kenaf/epoxy hybrid nanocomposites and organically modified MMT (OMMT)/kenaf/epoxy hybrid nanocomposites. Epoxy based kenaf hybrid nanocomposites was prepared by dispersing the nano filler (nano OPEFB filler, MMT, OMMT) at 3% loading through high speed mechanical stirrer followed by hand lay-up technique. Thermal properties of hybrid nanocomposites were analyzed through thermogravimetry analyzer (TGA), and differential scanning calorimetry (DSC). Obtained results specified that addition of nano OPEFB filler improves the thermal stability and char yield of kenaf/epoxy composites. Furthermore, the increase in decomposition temperature by the nano OPEFB filler was quite comparable to the MMT/kenaf/epoxy but relatively less than OMMT/kenaf/epoxy hybrid nanocomposites. We concluded from overall consequences that the nano OPEFB filler can be used as the promising and innovative alternative of existing expensive nano filler, with relatively lesser impact on the environment having marked pronounced impact on the construction, automotive, aerospace, electronics and semiconducting sectors as future industries based on bio-wastes with satisfactory light weight and thermal stability on other side.

  19. Sample-size resonance, ferromagnetic resonance and magneto-permittivity resonance in multiferroic nano-BiFeO3/paraffin composites at room temperature

    Science.gov (United States)

    Wang, Lei; Li, Zhenyu; Jiang, Jia; An, Taiyu; Qin, Hongwei; Hu, Jifan

    2017-01-01

    In the present work, we demonstrate that ferromagnetic resonance and magneto-permittivity resonance can be observed in appropriate microwave frequencies at room temperature for multiferroic nano-BiFeO3/paraffin composite sample with an appropriate sample-thickness (such as 2 mm). Ferromagnetic resonance originates from the room-temperature weak ferromagnetism of nano-BiFeO3. The observed magneto-permittivity resonance in multiferroic nano-BiFeO3 is connected with the dynamic magnetoelectric coupling through Dzyaloshinskii-Moriya (DM) magnetoelectric interaction or the combination of magnetostriction and piezoelectric effects. In addition, we experimentally observed the resonance of negative imaginary permeability for nano BiFeO3/paraffin toroidal samples with longer sample thicknesses D=3.7 and 4.9 mm. Such resonance of negative imaginary permeability belongs to sample-size resonance.

  20. Hybrid nano-structure for enhanced energy storage devices

    Science.gov (United States)

    Shuvo, Mohammad Arif Ishtiaque

    The goal of this research is to develop electrode materials using various nano-structure hybrids for improved energy storage devices. Enhancing the performance of energy storage device has been gaining tremendous attention since it holds the key solution to advance renewable energy usage thus reduce the consumption of fossil fuels. The application of energy storage devices such as super-capacitor and Li-ion-battery has seen significant growth; however, it is still limited mainly by charge/discharge rate and energy density. One of the solutions is to use nano-structure materials, which offer higher power at high energy density and improved stability during the charge discharge cycling of ions in and out of the storage electrode material. In this research, carbon-based materials (e.g. porous carbon, graphene) in conjunction with metal oxides such as CeO2 nanoparticles/TiO2 nanowires are synthesized utilizing low temperature hydrothermal method for the fabrication of advanced electrode materials. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), X-ray Photoelectron Spectroscopy (XPS), and Fourier Transformation Infrared Spectroscopy (FTIR) were used for materials characterization. Poentio-galvanostat, battery analyzer, and Electrochemical Impedance Spectroscopy (EIS) were used for evaluating the electrochemical performance. The testing results have shown that a maximum 500% higher specific capacitance could be obtained using porous carbon/CeO2 instead of porous carbon for super-capacitor application and microwave exfoliated graphene oxide/TiO2 nanowire hybrid provides up to 80% increment of specific capacity compared to porous carbon anode for Li-ion-battery application.

  1. Hybrid fiber resonator employing LRSPP waveguide coupler for gyroscope

    Science.gov (United States)

    Qian, Guang; Fu, Xing-Chang; Zhang, Li-Jiang; Tang, Jie; Liu, Yi-Ran; Zhang, Xiao-Yang; Zhang, Tong

    2017-01-01

    Polarization error and temperature noise are two main limits to the performance of resonant fiber optic gyroscope (RFOG). To overcome these limits, we demonstrated a hybrid resonator consisting of a polymer-based long-range surface plasmon polariton (LRSPP) waveguide coupler and a silica fiber. Single-polarization property of LRSPP waveguide and the offsetting of the opposite thermo-optical characteristics between the polymer-based LRSPP waveguide and the silica fiber can effectively inhibit both the polarization error and the temperature noise of RFOG. The measured resonance spectrum of the hybrid resonator shows the absence of polarization noise. The temperature dependence of wavelength shift (TDWS) of resonator dropped to about 2 pm/°C, or even to 0 pm/°C with optimal structure, which dramatically improves the temperature stability of gyroscope system. In addition, the hybrid resonator also shows tremendous application potential in rate-grade and tactical-grade gyroscopes. PMID:28117412

  2. Relative biocompatibility of micro-hybrid and nano-hybrid light-activated composite resins.

    Science.gov (United States)

    Olabisi Arigbede, Abiodun; Folasade Adeyemi, Bukola; Femi-Akinlosotu, Omowumi

    2017-01-01

    Background. In vitro studies have revealed a direct association between resin content and cytotoxicity of composite resins; however, implantation studies in this regard are sparse. This study investigates the relationship between filler content of composite resins and biocompatibility. Methods. This research employed twelve 180‒200-gr male Wistar rats, 1 nano-hybrid (Prime-Dent Inc.) and 1 micro-hybrid (Medental Inc.) composite resins containing 74% and 80‒90% filler content, respectively. The samples were assessed on the 2nd, 14th and 90th day of implantation. Four rats were allocated to each day in this experimental study. A section of 1.5mm long cured nano-hybrid and micro-hybrid materials were implanted into the right and left upper and lower limbs of the rats, respectively. Eight samples were generated on each day of observation. Inflammation was graded according to the criteria suggested by Orstavik and Major. Pearson's chi-squared test was employed to determine the relationship between the tissue responses of the two materials. Statistical significance was set at P composite resins with higher filler content elicited a significantly lower grade of inflammation irrespective of the duration (χ=20.000, df=8, P=0.010) while the composite resins with lower filler content elicited a significantly lower inflammatory response on the 90th day (χ=4.000, df=1, P=0.046). Conclusion. The composite resins with higher filler content generally elicited significantly lower grades of inflammation, and the composite resins with lower filler content exhibited significantly lower inflammatory response on the 90th day of implantation.

  3. Preparation of hybrid nano biocomposite κ-carrageenan/cellulose nanocrystal/nanoclay

    Science.gov (United States)

    Zakuwan, Siti Zarina; Ahmad, Ishak; Ramli, Nazaruddin

    2013-11-01

    Biodegradable composites film based on κ-carrageenan and nano particles as filler was prepared to study the mechanical strength of carrageenan composites. Solution casting technique was used to prepare_this biocomposite. Preparation of composite film and nano filler involve two stages, preparation of cellulose nanocrystals (CNC) from kenaf with alkali treatment, bleaching, and hydrolysis followed by the preparation of two types of nano composite. Tensile test was carried on the composite film based on κ-carrageenan with the variation percentage of CNC and nano clay to obtain the optimum CNC and nano clay loading. After that hybrid nano-biocomposite film based on κ-carrageenan with the variation percentage of CNC/nano clay (OMMT) according to optimum value of composite carrageenan/CNC and composite carrageenan/nano clay film was prepared. The effect of nano filler on the mechanical properties of carrageenan films was examined. κ-carrageenan biocomposite increased with the optimum at 4% CNC and nano clay composition. Additional improvement of tensile strength with hybridization of CNC and nanoclay indicated better mechanical properties.

  4. Hybrid III-V/SOI resonant cavity enhanced photodetector

    DEFF Research Database (Denmark)

    Learkthanakhachon, Supannee; Taghizadeh, Alireza; Park, Gyeong Cheol;

    2016-01-01

    A hybrid III–V/SOI resonant-cavity-enhanced photodetector (RCE-PD) structure comprising a high-contrast grating (HCG) reflector, a hybrid grating (HG) reflector, and an air cavity between them, has been proposed and investigated. In the proposed structure, a light absorbing material is integrated...

  5. The spectral shift between near- and far-field resonances of optical nano-antennas.

    Science.gov (United States)

    Menzel, Christoph; Hebestreit, Erik; Mühlig, Stefan; Rockstuhl, Carsten; Burger, Sven; Lederer, Falk; Pertsch, Thomas

    2014-04-21

    Within the past several years a tremendous progress regarding optical nano-antennas could be witnessed. It is one purpose of optical nano-antennas to resonantly enhance light-matter interactions at the nanoscale, e.g. the interaction of an external illumination with molecules. In this specific, but in almost all schemes that take advantage of resonantly enhanced electromagnetic fields in the vicinity of nano-antennas, the precise knowledge of the spectral position of resonances is of paramount importance to fully exploit their beneficial effects. Thus far, however, many nano-antennas were only optimized with respect to their far-field characteristics, i.e. in terms of their scattering or extinction cross sections. Although being an emerging feature in many numerical simulations, it was only recently fully appreciated that there exists a subtle but very important difference in the spectral position of resonances in the near-and the far-field. With the purpose to quantify this shift, Zuloaga et al. suggested a Lorentzian model to estimate the resonance shift. Here, we devise on fully analytical grounds a strategy to predict the resonance in the near-field directly from that in the far-field and disclose that the issue is involved and multifaceted, in general. We outline the limitations of our theory if more sophisticated optical nano-antennas are considered where higher order multipolar contributions and higher order antenna resonances become increasingly important. Both aspects are highlighted by numerically studying relevant nano-antennas.

  6. Mechanical and tribological studies on nano particles reinforced hybrid aluminum based composite

    Directory of Open Access Journals (Sweden)

    Muley Aniruddha V.

    2015-01-01

    Full Text Available Hybrid metal matrix composites are new class of materials due to their better mechanical properties which can be achieved through proper selection and combination of materials. The work reported in this paper is based on fabrication of hybrid composites by using nano particles as reinforcements. The hybrid composites were fabricated by reinforcing them with nano sized SiC and Al2O3 particles in order to study mechanical and tribological properties of these enhanced materials. A stir casting method was used to obtain hybrid composites. LM 6 aluminum alloy was used as a matrix material. The results shown increase in hardness as well as in ultimate tensile strength of the composites with small wt.% of nano-sized hybrid reinforcements. The composites produced also exhibit better tribological properties.

  7. Low insertion loss SOI microring resonator integrated with nano-taper couplers

    DEFF Research Database (Denmark)

    Pu, Minhao; Frandsen, Lars Hagedorn; Ou, Haiyan;

    2009-01-01

    We demonstrate a microring resonator working at TM mode integrated with nano-taper couplers with 3.6dB total insertion loss. The measured insertion loss of the nano-taper coupler was only 1.3dB for TM mode....

  8. A reconfigurable subwavelength plasmonic fano nano-antenna based on split ring resonator

    Science.gov (United States)

    Hosseinbeig, Ahmad; Pirooj, Azadeh; Zarrabi, Ferdows B.

    2017-02-01

    In this article, a reconfigurable subwavelength plasmonic nano-antenna with Fano resonance effect is presented based on the dual ring structure. In order to achieve reconfigurable characteristics, the interaction of gold with graphene is studied. SiN substrate with refractive index of 1.98 and gold with Palik optical characteristic modified for metal layer are utilized in the design of the proposed nano-antenna. Simulations are performed by using CST Microwave Studio. The biasing effect on extinction cross section is studied for 0 to 0.8 eV. It is shown that the gap method is useful for exciting the Fano resonance in the dual ring nano-antenna and there is only a plasmonic resonance in the simple dual ring antenna. The proposed nano-antenna is useful for THz medical spectroscopy due to its simple design and the ability to control the second resonance frequency by changing the bias of the graphene.

  9. Resonant bowtie aperture nano-antenna for the control of optical nanocavities resonance

    CERN Document Server

    Baida, Fadi Issam

    2015-01-01

    Scanning Near-field Optical Microscopy (SNOM) has been successful in finely tuning the optical properties of photonic crystal (PC) nanocavities. The SNOM nanoprobes proposed so far allowed for either redshifting or blueshifting the resonance peak of the PC structures. In this Letter, we theoretically demonstrate the possibility of redshifting (up to +0.65nm) and blueshifting (up to $-5$~nm) PC cavity resonance with a single SNOM probe. This probe is obtained by opening a bowtie-aperture nano-antenna (BNA) at the apex of a metal-coated tip. This double-way PC tunability is the result of a competition between the effects of the BNA resonance (induced electric dipole leading to a redshift) and the metal-coated tip (induced magnetic dipole giving rise to a blueshift) onto the PC mode volume. The sign of the spectral shift is modified by simply controlling the tip-to-PC distance. This study opens the way to the full postproduction control of the resonance wavelength of high quality factor optical cavities.

  10. Hybrid simulation of electron cyclotron resonance heating

    CERN Document Server

    Ropponen, T; Suominen, P; Koponen, T K; Kalvas, T; Koivisto, H

    2008-01-01

    Electron Cyclotron Resonance (ECR) heating is a fundamentally important aspect in understanding the physics of Electron Cyclotron Resonance Ion Sources (ECRIS). Absorption of the radio frequency (RF) microwave power by electron heating in the resonance zone depends on many parameters including frequency and electric field strength of the microwave, magnetic field structure and electron and ion density profiles. ECR absorption has been studied in the past by e.g. modelling electric field behaviour in the resonance zone and its near proximity. This paper introduces a new ECR heating code that implements damping of the microwave power in the vicinity of the resonance zone, utilizes electron density profiles and uses right hand circularly polarized (RHCP) electromagnetic waves to simulate electron heating in ECRIS plasma.

  11. Hybrid simulation of electron cyclotron resonance heating

    Energy Technology Data Exchange (ETDEWEB)

    Ropponen, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)], E-mail: tommi.ropponen@phys.jyu.fi; Tarvainen, O. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Suominen, P. [CERN Geneve 23, CH-1211 (Switzerland); Koponen, T.K. [Department of Physics, University of Jyvaeskylae, Nanoscience Center, P.O. Box 35, FI-40014 (Finland); Kalvas, T.; Koivisto, H. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)

    2008-03-11

    Electron Cyclotron Resonance (ECR) heating is a fundamentally important aspect in understanding the physics of Electron Cyclotron Resonance Ion Sources (ECRIS). Absorption of the radio frequency (RF) microwave power by electron heating in the resonance zone depends on many parameters including frequency and electric field strength of the microwave, magnetic field structure and electron and ion density profiles. ECR absorption has been studied in the past by e.g. modelling electric field behaviour in the resonance zone and its near proximity. This paper introduces a new ECR heating code that implements damping of the microwave power in the vicinity of the resonance zone, utilizes electron density profiles and uses right hand circularly polarized (RHCP) electromagnetic waves to simulate electron heating in ECRIS plasma.

  12. Resonant enhancement of Raman scattering in metamaterials with hybrid electromagnetic and plasmonic resonances

    CERN Document Server

    Guddala, Sriram; Ramakrishna, S Anantha

    2016-01-01

    A tri-layer metamaterial perfect absorber of light, consisting of (Al/ZnS/Al) films with the top aluminium layer patterned as an array of circular disk nanoantennas, is investigated for resonantly enhancing Raman scattering from C-60 fullerene molecules deposited on the metamaterial. The metamaterial is designed to have resonant bands due to plasmonic and electromagnetic resonances at the Raman pump frequency (725 nm) as well as Stokes emission bands. The Raman scattering from C60 on the metamaterial with resonantly matched bands is measured to be enhanced by an order of magnitude more than from C60 on metamaterials with off-resonant absorption bands peaked at 1090 nm. The Raman pump is significantly enhanced due to the resonance with a propagating surface plasmon band, while the highly impedance matched electromagnetic resonance is expected to couple out the Raman emission efficiently. The nature and hybridization of the plasmonic and electromagnetic resonances to form compound resonances are investigated by...

  13. Photonic molecules formed by coupled hybrid resonators

    CERN Document Server

    Peng, Bo; Zhu, Jiangang; Yang, Lan; 10.1364/OL.37.003435

    2013-01-01

    We describe a method that enables free-standing whispering-gallery-mode microresonators, and report spectral tuning of photonic molecules formed by coupled free and on-chip resonators with different geometries and materials. We study direct coupling via evanescent fields of free silica microtoroids and microspheres with on-chip polymer coated silica microtoroids. We demonstrate thermal tuning of resonance modes to achieve maximal spectral overlap, mode splitting induced by direct coupling, and the effects of distance between the resonators on the splitting spectra.

  14. Hybrid resonant organic-inorganic nanostructures for novel light emitting devices and solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Agranovich, Vladimir M. [Institute of Spectroscopy, Russian Academy of Science, Troitsk, Moscow (Russian Federation); Chemistry Department, University of Texas at Dallas, Texas (United States); Rupasov, Valery I. [ANTEOS, Inc., Shrewsbury, Massachusetts 01545 (United States); Silvestri, Leonardo [Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano Bicocca, Milano (Italy)

    2010-06-15

    The energy transfer from an inorganic layer to an organic component of resonant hybrid organic/inorganic nanos-tructures can be used for creation of new type of LED. We mentioned the problem of electrical pumping which has to be solved. As was first suggested in 1979 by Dexter the transfer energy in opposite direction from organic part of nanostructure to semiconductor layer can be used for the creation of new type of solar cells. In this note we stress the importance of the idea by Dexter for photovoltaics and solar cells. We argue that the organic part in such hybrid structures can play a role of an effective organic collector of the light energy (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Hybrid Plasmonic Waveguide Fed Broadband Nano-antenna for Nanophotonic Applications

    OpenAIRE

    Saad-Bin-Alam, Md; Khalil, Md. Ibrahim; Rahman, Atiqur; Chowdhury, Arshad M.

    2014-01-01

    In this paper, we propose a novel hybrid plasmonic waveguide fed broadband optical patch nano-antenna for nanophotonic applications. Through full wave electromagnetic simulation, we demonstrated our proposed antenna to radiate and receive signal at all optical communication windows (e.g. $\\lambda$ = 850nm, 1310nm & 1550nm) with around 86% bandwidth within the operational domain. Moreover numerical results demonstrate that the proposed nano-antenna has directional radiation pattern with satisf...

  16. Organic-inorganic Polymer Nano-hybrids Based on Sol-gel Reaction

    Institute of Scientific and Technical Information of China (English)

    Yoshiki; Chujo

    2007-01-01

    1 Results Nano-ordered composite materials consisting of organic polymers and inorganic materials have been attracting attention for the purpose of the creation of high-performance or high-functional polymeric materials. Especially,the word of "polymer hybrid" claims the blends of organic and inorganic components at nano-level dispersion. By using this idea,an enhancement of mechanical strength of organic polymers with silica particles is possible.High transparency of this material is another important ...

  17. Hybrid switch for resonant power converters

    Science.gov (United States)

    Lai, Jih-Sheng; Yu, Wensong

    2014-09-09

    A hybrid switch comprising two semiconductor switches connected in parallel but having different voltage drop characteristics as a function of current facilitates attainment of zero voltage switching and reduces conduction losses to complement reduction of switching losses achieved through zero voltage switching in power converters such as high-current inverters.

  18. Studies on Effective Elastic Properties of CNT/Nano-Clay Reinforced Polymer Hybrid Composite

    Science.gov (United States)

    Thakur, Arvind Kumar; Kumar, Puneet; Srinivas, J.

    2016-02-01

    This paper presents a computational approach to predict elastic propertiesof hybrid nanocomposite material prepared by adding nano-clayplatelets to conventional CNT-reinforced epoxy system. In comparison to polymers alone/single-fiber reinforced polymers, if an additional fiber is added to the composite structure, it was found a drastic improvement in resultant properties. In this regard, effective elastic moduli of a hybrid nano composite are determined by using finite element (FE) model with square representative volume element (RVE). Continuum mechanics based homogenization of the nano-filler reinforced composite is considered for evaluating the volumetric average of the stresses and the strains under different periodic boundary conditions.A three phase Halpin-Tsai approach is selected to obtain the analytical result based on micromechanical modeling. The effect of the volume fractions of CNTs and nano-clay platelets on the mechanical behavior is studied. Two different RVEs of nano-clay platelets were used to investigate the influence of nano-filler geometry on composite properties. The combination of high aspect ratio of CNTs and larger surface area of clay platelets contribute to the stiffening effect of the hybrid samples. Results of analysis are validated with Halpin-Tsai empirical formulae.

  19. Strongly coupled inorganic-nano-carbon hybrid materials for energy storage.

    Science.gov (United States)

    Wang, Hailiang; Dai, Hongjie

    2013-04-07

    The global shift of energy production from fossil fuels to renewable energy sources requires more efficient and reliable electrochemical energy storage devices. In particular, the development of electric or hydrogen powered vehicles calls for much-higher-performance batteries, supercapacitors and fuel cells than are currently available. In this review, we present an approach to synthesize electrochemical energy storage materials to form strongly coupled hybrids (SC-hybrids) of inorganic nanomaterials and novel graphitic nano-carbon materials such as carbon nanotubes and graphene, through nucleation and growth of nanoparticles at the functional groups of oxidized graphitic nano-carbon. We show that the inorganic-nano-carbon hybrid materials represent a new approach to synthesize electrode materials with higher electrochemical performance than traditional counterparts made by simple physical mixtures of electrochemically active inorganic particles and conducting carbon materials. The inorganic-nano-carbon hybrid materials are novel due to possible chemical bonding between inorganic nanoparticles and oxidized carbon, affording enhanced charge transport and increased rate capability of electrochemical materials without sacrificing specific capacity. Nano-carbon with various degrees of oxidation provides a novel substrate for nanoparticle nucleation and growth. The interactions between inorganic precursors and oxidized-carbon substrates provide a degree of control over the morphology, size and structure of the resulting inorganic nanoparticles. This paper reviews the recent development of inorganic-nano-carbon hybrid materials for electrochemical energy storage and conversion, including the preparation and functionalization of graphene sheets and carbon nanotubes to impart oxygen containing groups and defects, and methods of synthesis of nanoparticles of various morphologies on oxidized graphene and carbon nanotubes. We then review the applications of the SC-hybrid

  20. Hybrid III-V/SOI Resonant Cavity Photodetector

    DEFF Research Database (Denmark)

    Learkthanakhachon, Supannee; Taghizadeh, Alireza; Park, Gyeong Cheol;

    2016-01-01

    A hybrid III-V/SOI resonant cavity photo detector has been demonstrated, which comprises an InP grating reflectorand a Si grating reflector. It can selectively detects an incident light with 1.54-µm wavelength and TM polarization....

  1. Frequency Shifts of Micro and Nano Cantilever Beam Resonators Due to Added Masses

    KAUST Repository

    Bouchaala, Adam M.

    2016-03-21

    We present analytical and numerical techniques to accurately calculate the shifts in the natural frequencies of electrically actuated micro and nano (carbon nanotubes (CNTs)) cantilever beams implemented as resonant sensors for mass detection of biological entities, particularly Escherichia coli (E. coli) and prostate specific antigen (PSA) cells. The beams are modeled as Euler-Bernoulli beams, including the nonlinear electrostatic forces and the added biological cells, which are modeled as discrete point masses. The frequency shifts due to the added masses of the cells are calculated for the fundamental and higher-order modes of vibrations. Analytical expressions of the natural frequency shifts under a direct current (DC) voltage and an added mass have been developed using perturbation techniques and the Galerkin approximation. Numerical techniques are also used to calculate the frequency shifts and compared with the analytical technique. We found that a hybrid approach that relies on the analytical perturbation expression and the Galerkin procedure for calculating accurately the static behavior presents the most computationally efficient approach. We found that using higher-order modes of vibration of micro-electro-mechanical-system (MEMS) beams or miniaturizing the sizes of the beams to nanoscale leads to significant improved frequency shifts, and thus increased sensitivities. © 2016 by ASME.

  2. Quality factor enhancement of Nano electromechanical systems by capacitive driving beyond the resonance

    CERN Document Server

    Barois, T; Poncharal, P; Vincent, Philippe; Ayari, A

    2016-01-01

    Nano electromechanical systems are considered as ultra sensitive devices for mass and force detection. Capacitive actuation is widely used in these devices but is known to degrade the quality factor of the resonator due to DC electrostatic damping. We report the enhancement of the quality factor of SiC vibrating nanowires detected nano optomechanically and electrically by applying an AC capacitive driving at a frequency above both the resonance frequency and the electrical cutoff frequency. Self-oscillations are demonstrated for optimal conditions. We developed an analytical model of the phenomenon and showed that it can lead to an improvement of the force sensitivity. * anthony.ayari@univ-lyon1.fr 1

  3. Bio-Nano ECRIS: an electron cyclotron resonance ion source for new materials production.

    Science.gov (United States)

    Uchida, T; Minezaki, H; Tanaka, K; Muramatsu, M; Asaji, T; Kato, Y; Kitagawa, A; Biri, S; Yoshida, Y

    2010-02-01

    We developed an electron cyclotron resonance ion source (ECRIS) for new materials production on nanoscale. Our main target is the endohedral fullerenes, which have potential in medical care, biotechnology, and nanotechnology. In particular, iron-encapsulated fullerene can be applied as a contrast material for magnetic resonance imaging or microwave heat therapy. Thus, our new ECRIS is named the Bio-Nano ECRIS. In this article, the recent progress of the development of the Bio-Nano ECRIS is reported: (i) iron ion beam production using induction heating oven and (ii) optimization of singly charged C(60) ion beam production.

  4. On hydrophilicity improvement of the porous anodic alumina film by hybrid nano/micro structuring

    Science.gov (United States)

    Wang, Weichao; Zhao, Wei; Wang, Kaige; Wang, Lei; Wang, Xuewen; Wang, Shuang; Zhang, Chen; Bai, Jintao

    2017-09-01

    In both, laboratory and industry, tremendous attention is paid to discover an effective technique to produce uniform, controllable and (super) hydrophilic surfaces over large areas that are useful in a wide range of applications. In this investigation, by combing porous anodic alumina (PAA) film with nano-structures and microarray of aluminum, the hydrophilicity of hybrid nano-micro structure has been significantly improved. It is found some factors can affect the hydrophilicity of film, such as the size and aspect ratio of microarray, the thickness of nano-PAA film etc. Comparing with pure nano-PAA films and microarray, the hybrid nano-micro structure can provide uniform surface with significantly better hydrophilicity. The improvement can be up to 84%. Also, this technique exhibits good stability and repeatability for industrial production. By optimizing the thickness of nano-PAA film and aspect ratio of micro-structures, super-hydrophilicity can be reached. This study has obvious prospect in the fields of chemical industry, biomedical engineering and lab-on-a-chip applications.

  5. Manufacturing of aluminium nano hybrid composites: a state of review

    Science.gov (United States)

    Madhukar, P.; Selvaraj, N.; Rao, CSP

    2016-09-01

    This paper gives the details of hybrid composites, their fabrication methods and evaluation of mechanical, tribological behaviour and machining characteristics. Investigations on the various aspects of Hybrid composites furnish several conclusions regarding the influence of various parameters on the performance of the composites. Mostly micro structures of the hybrid composites fabricated through casting routes have been found to be stable with the distribution of uniformed reinforce particles. therefore, the hybrid composites can be constructed with various combinations of reinforcements to carry out desirable mechanical properties. The density of Hybrid composites increases with increasing reinforcements such as SiC, TiC, B4C....etc, while incorporation of partial reinforcements like fly ash, mica, rice husk, etc. reduces the density of composites. The study also reports that the hybrid composites can be treated as a replacement for regular composite materials in different advanced applications.

  6. Hybrid squeezing of solitonic resonant radiation in photonic crystal fibers

    CERN Document Server

    Tran, Truong X; Soeller, Christoph; Blow, Keith J; Biancalana, Fabio

    2011-01-01

    We report on the existence of a novel kind of squeezing in photonic crystal fibers which is conceptually intermediate between the four-wave mixing induced squeezing, in which all the participant waves are monochromatic waves, and the self-phase modulation induced squeezing for a single pulse in a coherent state. This hybrid squeezing occurs when an arbitrary short soliton emits quasi-monochromatic resonant radiation near a zero group velocity dispersion point of the fiber. Photons around the resonant frequency become strongly correlated due to the presence of the classical soliton, and a reduction of the quantum noise below the shot noise level is predicted.

  7. Influence of layer eccentricity on the resonant properties of cylindrical active coated nano-particles

    DEFF Research Database (Denmark)

    Thorsen, R. O.; Arslanagic, Samel

    2015-01-01

    We report on the influence of the layer eccentricity on the resonant properties of active coated nano-particles made of a silver core and gain impregnated silica shell illuminated by a near-by magnetic line source. For a fixed over-all size of the particle, designs with small and large cores...

  8. Measurement of the Resonant Frequency of Nano-Scale Cantilevers by Hard Contact Readout

    DEFF Research Database (Denmark)

    Dohn, Søren; Hansen, Ole; Bolsen, A.

    2008-01-01

    It is shown that detection of the resonant frequency of a nano-scale cantilever is possible by measuring the time average current flowing from an electrode to the cantilever during hard contact occurring twice every cycle of the cantilever vibration. The electronic detection method is insensitive....... The readout method is thereby ideally suited for portable sensor systems....

  9. Hybrid material as contrast agent in magnetic resonance images

    OpenAIRE

    Botella Asunción, Pablo; Cabrera García, Alejandro

    2015-01-01

    [EN] The invention relates to a contrast agent of magnetic resonance based on a hybrid material formed by an organo-metallic core derived from Prussian blue and a silica cover, and optionally, molecules of a poly(ethylene glycol), a fluorescent agent, a radio nucleus and/or a substance that directs to specific receptors, cells or tissues, joined by covalent bonding to the surface of the inorganic cover.

  10. Hybrid material as contrast agent in magnetic resonance images

    OpenAIRE

    Botella Asunción, Pablo; Cabrera García, Alejandro

    2015-01-01

    [EN] The invention relates to a contrast agent of magnetic resonance based on a hybrid material formed by an organo-metallic core derived from Prussian blue and a silica cover, and optionally, molecules of a poly(ethylene glycol), a fluorescent agent, a radio nucleus and/or a substance that directs to specific receptors, cells or tissues, joined by covalent bonding to the surface of the inorganic cover.

  11. Preparation and characterization of biodegradable aliphatic-aromatic copolyesters/nano-SiO_2 hybrids via in situ melt polycondensation

    Institute of Scientific and Technical Information of China (English)

    Yan Zhang; Bing Tao Wang; Zheng Hong Guo; Jie Chen; Zheng Ping Fang

    2009-01-01

    In situ melt polycondensation was proposed to prepare biodegradable aliphatic-aromatic copolyesters/nano-SiO_2 hybrids based on terephthalic acid (TPA), poly(L-lactic acid) oligomer (OLLA), 1,4-butanediol (BDO) and nano-SiO_2. TEM and FT-IR characterizations confirmed that TPA, OLLA and BDO copolymerized to obtain biodegradable copolyesters, poly(butylene terephthalate-co-lactate) (PBTL), and the abundant hydroxyl groups on the surface of nano-SiO_2 provided potential sites for in situ grafting with the simultaneous resulted PBTL. The nano-SiO_2 particles were chemically wrapped with PBTL to form PBTL/nano-SiO2 hybrids. Due to the good dispersion and interfacial adhesion of nano-SiO_2 particles with the copolyester matrix, the tensile strength and the Young's modulus increased from 5.4 and 5.6 Mpa for neat PBTL to 16 and 390 Mpa for PBTL/nano-SiO_2 hybrids with 5 wt.% nano-SiO_2, respectively. The mechanical properties of PBTL/nano-SiO_2 hybrids were substantially improved.

  12. Beam shaping characteristics of an unstable-waveguide hybrid resonator.

    Science.gov (United States)

    Xiao, Longsheng; Qin, Yingxiong; Tang, Xiahui; Wan, Chenhao; Li, Gen; Zhong, Lijing

    2014-04-01

    The unstable-waveguide hybrid resonator emits a rectangular, simple astigmatic beam with a large number of high-spatial-frequency oscillations in the unstable direction. To equalize the beam quality, in this paper, a beam shaping system with a spatial filter for the hybrid resonator was investigated by numerical simulation and experimental method. The high-frequency components and fundamental mode of the output beam of the hybrid resonator in the unstable direction are separated by a focus lens. The high-frequency components of the beam are eliminated by the following spatial filter. A nearly Gaussian-shaped beam with approximately equal beam propagation factor M² in the two orthogonal directions was obtained. The effects of the width of the spatial filter on the beam quality, power loss, and intensity distribution of the shaped beam were investigated. The M² factor in the unstable direction is changed from 1.6 to 1.1 by optimum design. The power loss is only 9.5%. The simulation results are in good agreement with the experimental results.

  13. Fracture Toughness Evaluation of Hybrid and Nano-hybrid Resin Composites after Ageing under Acidic Environment

    Directory of Open Access Journals (Sweden)

    Ferooz M

    2015-03-01

    Full Text Available Statement of Problem: Tooth-coloured restorative materials are brittle with the major shortcomings of sensitivity to flaws and defects. Although various mechanical properties of resin composites have been studied, no fracture toughness test data for nano-hybrid composites under acidic condition for a long period of time has been published. Objectives: To compare the fracture toughness (KIc of two types of resin composites under tensile loading and to assess the effect of distilled water and lactic acid on the resistance of the restoratives to fracture after three months of immersion. Materials and Methods: Four resin composites were used: three nanohybrids [EsteliteSigma Quick (Kuraray, Luna (SDI, Paradigm (3M/ESPE] and one hybrid, Rok (SDI. The specimens were prepared using a custom-made polytetrafluorethylene split mould, stored in distilled water (pH 6.8 or 0.01mol/L lactic acid (pH 4 and conditioned at 37°C for 24 hours, 1 or 3 months. They were loaded under tensile stress using a universal testing machine; the maximum load (N to the specimen failure was recorded and the fracture toughness (KIc was calculated. Data were analysed by ANOVA and Tukey’s test using SPSS, version 18. Results: The results of two-way ANOVA did not show a significant combined effect of material, time, and storage medium on fracture toughness (p= 0.056. However, there was a strong interaction between materials and time (p=0.001 when the storage medium were ignored. After 24 h of immersion in distilled water, Paradigm revealed the highest KIc values followed by Rok, Luna and Estelite. Immersion in either distilled water or lactic acid significantly decreased the fracture toughness of almost all materials as time interval increased. Conclusions: Paradigm showed the highest fracture toughness followed by Rok, Luna and Estelite respectively. As time increased, KIc significantly decreased for almost all resin composites except for Luna which showed a slight decrease

  14. Slow-plasmon resonant nano-strip antennas

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Beermann, Jonas; Boltasseva, Alexandra

    2008-01-01

    Resonant scattering by gold nanostrip antennas due to constructive interference of counterpropagating slow surface plasmon polaritons SPPs is analyzed, including the quasistatic limit of ultrasmall antennas, and experimentally demonstrated. The phase of slow SPP reflection by strip ends is found...

  15. Nanoimprinted Hybrid Metal-Semiconductor Plasmonic Multilayers with Controlled Surface Nano Architecture for Applications in NIR Detectors

    Directory of Open Access Journals (Sweden)

    Akram A. Khosroabadi

    2015-08-01

    Full Text Available We present a proof of concept for tunable plasmon resonance frequencies in a core shell nano-architectured hybrid metal-semiconductor multilayer structure, with Ag as the active shell and ITO as the dielectric modulation media. Our method relies on the collective change in the dielectric function within the metal semiconductor interface to control the surface. Here we report fabrication and optical spectroscopy studies of large-area, nanostructured, hybrid silver and indium tin oxide (ITO structures, with feature sizes below 100 nm and a controlled surface architecture. The optical and electrical properties of these core shell electrodes, including the surface plasmon frequency, can be tuned by suitably changing the order and thickness of the dielectric layers. By varying the dimensions of the nanopillars, the surface plasmon wavelength of the nanopillar Ag can be tuned from 650 to 690 nm. Adding layers of ITO to the structure further shifts the resonance wavelength toward the IR region and, depending on the sequence and thickness of the layers within the structure, we show that such structures can be applied in sensing devices including enhancing silicon as a photodetection material.

  16. Resonant enhancement of Raman scattering in metamaterials with hybrid electromagnetic and plasmonic resonances

    Science.gov (United States)

    Guddala, Sriram; Narayana Rao, D.; Ramakrishna, S. Anantha

    2016-06-01

    A tri-layer metamaterial perfect absorber of light, consisting of (Al/ZnS/Al) films with the top aluminum layer patterned as an array of circular disk nanoantennas, is investigated for resonantly enhancing Raman scattering from C60 fullerene molecules deposited on the metamaterial. The metamaterial is designed to have resonant bands due to plasmonic and electromagnetic resonances at the Raman pump frequency (725 nm) as well as Stokes emission bands. The Raman scattering from C60 on the metamaterial with resonantly matched bands is measured to be enhanced by an order of magnitude more than C60 on metamaterials with off-resonant absorption bands peaking at 1090 nm. The Raman pump is significantly enhanced due to the resonance with a propagating surface plasmon band, while the highly impedance-matched electromagnetic resonance is expected to couple out the Raman emission efficiently. The nature and hybridization of the plasmonic and electromagnetic resonances to form compound resonances are investigated by numerical simulations.

  17. Overview of the Characteristics of Micro- and Nano-Structured Surface Plasmon Resonance Sensors

    Directory of Open Access Journals (Sweden)

    Byoungho Lee

    2011-01-01

    Full Text Available The performance of bio-chemical sensing devices has been greatly improved by the development of surface plasmon resonance (SPR based sensors. Advancements in micro- and nano-fabrication technologies have led to a variety of structures in SPR sensing systems being proposed. In this review, SPR sensors (from typical Kretschmann prism configurations to fiber sensor schemes with micro- or nano-structures for local light field enhancement, extraordinary optical transmission, interference of surface plasmon waves, plasmonic cavities, etc. are discussed. We summarize and compare their performances and present guidelines for the design of SPR sensors.

  18. RESONANT PHOTOEMISSION OF BULK CeO2 AND NANO-CeO2 FILMS

    Institute of Scientific and Technical Information of China (English)

    M.I. Abbas; K. Ibrahim; Z.Y. Wu; J. Zhang; F.Q. Liu; H.J. Qian

    2001-01-01

    Photoemission behaviors of nano-CeO2 films with particle sizes ranging from 8nm 1o50nm and bulk CeO2 in Ce 4d-4f absorption region have been investigated. Resonantenhancements of Ce 4f valance band and Ce 5p bands for nano film and bulk materialhave been observed. The variation of electron density of states in valance bands ofnano and bulk structures of CeO2 is discussed in terms of Ce 4d-4f resonance.

  19. Status of the Bio-Nano electron cyclotron resonance ion source at Toyo University.

    Science.gov (United States)

    Uchida, T; Minezaki, H; Ishihara, S; Muramatsu, M; Rácz, R; Asaji, T; Kitagawa, A; Kato, Y; Biri, S; Drentje, A G; Yoshida, Y

    2014-02-01

    In the paper, the material science experiments, carried out recently using the Bio-Nano electron cyclotron resonance ion source (ECRIS) at Toyo University, are reported. We have investigated several methods to synthesize endohedral C60 using ion-ion and ion-molecule collision reaction in the ECRIS. Because of the simplicity of the configuration, we can install a large choice of additional equipment in the ECRIS. The Bio-Nano ECRIS is suitable not only to test the materials production but also to test technical developments to improve or understand the performance of an ECRIS.

  20. Status of the Bio-Nano electron cyclotron resonance ion source at Toyo University

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, T., E-mail: uchida-t@toyo.jp [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Minezaki, H.; Ishihara, S. [Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan); Muramatsu, M.; Kitagawa, A.; Drentje, A. G. [National Institute of Radiological Sciences (NIRS), Chiba 263-8555 (Japan); Rácz, R.; Biri, S. [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen (Hungary); Asaji, T. [Oshima National College of Maritime Technology, Yamaguchi 742-2193 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan)

    2014-02-15

    In the paper, the material science experiments, carried out recently using the Bio-Nano electron cyclotron resonance ion source (ECRIS) at Toyo University, are reported. We have investigated several methods to synthesize endohedral C{sub 60} using ion-ion and ion-molecule collision reaction in the ECRIS. Because of the simplicity of the configuration, we can install a large choice of additional equipment in the ECRIS. The Bio-Nano ECRIS is suitable not only to test the materials production but also to test technical developments to improve or understand the performance of an ECRIS.

  1. Advanced Finite Element Method for Nano-Resonators

    CERN Document Server

    Zschiedrich, L; Kettner, B; Schmidt, F

    2006-01-01

    Miniaturized optical resonators with spatial dimensions of the order of the wavelength of the trapped light offer prospects for a variety of new applications like quantum processing or construction of meta-materials. Light propagation in these structures is modelled by Maxwell's equations. For a deeper numerical analysis one may compute the scattered field when the structure is illuminated or one may compute the resonances of the structure. We therefore address in this paper the electromagnetic scattering problem as well as the computation of resonances in an open system. For the simulation efficient and reliable numerical methods are required which cope with the infinite domain. We use transparent boundary conditions based on the Perfectly Matched Layer Method (PML) combined with a novel adaptive strategy to determine optimal discretization parameters like the thickness of the sponge layer or the mesh width. Further a novel iterative solver for time-harmonic Maxwell's equations is presented.

  2. Vlasov Simulations of Ionospheric Heating Near Upper Hybrid Resonance

    Science.gov (United States)

    Najmi, A. C.; Eliasson, B. E.; Shao, X.; Milikh, G. M.; Papadopoulos, K.

    2014-12-01

    It is well-known that high-frequency (HF) heating of the ionosphere can excite field- aligned density striations (FAS) in the ionospheric plasma. Furthermore, in the neighborhood of various resonances, the pump wave can undergo parametric instabilities to produce a variety of electrostatic and electromagnetic waves. We have used a Vlasov simulation with 1-spatial dimension, 2-velocity dimensions, and 2-components of fields, to study the effects of ionospheric heating when the pump frequency is in the vicinity of the upper hybrid resonance, employing parameters currently available at ionospheric heaters such as HAARP. We have found that by seeding theplasma with a FAS of width ~20% of the simulation domain, ~10% depletion, and by applying a spatially uniform HF dipole pump electric field, the pump wave gives rise to a broad spectrum of density fluctuations as well as to upper hybrid and lower hybrid oscillating electric fields. We also observe collisionless bulk-heating of the electrons that varies non-linearly with the amplitude of the pump field.

  3. Effect of aggressive beverage on the color stability of different nano-hybrid resin based composite

    Directory of Open Access Journals (Sweden)

    Hicham Oday Nuaimi

    2014-01-01

    Full Text Available Background: The purpose of this study was to evaluate the color stability of different types of nano-hybrid resin based composite restorative materials upon exposure to aggressive staining solutions (coffee and tea over time. The color of all specimens before and after storage in the solutions were measured by a spectrophotometer based on CIE Lab system that is recommended by the American Dental Association and the color differences thereby is calculated. Materials and Methods: The color differences of three nano-hybrid composites after immersion for 30 days in tea and coffee as aggressive beverage solutions. Results: Within the limitations of the study, Venus Diamond was found the most color stable in tea, while Ceram X was shown the most color stable in coffee. There were statistically significant differences between Filtek 350 XT in tea and coffee storage (P 0.005. Conclusion: Staining solutions are significant factors that affect color stability of composite resins.

  4. 17.6%-Efficient radial junction solar cells using silicon nano/micro hybrid structures

    Science.gov (United States)

    Lee, Kangmin; Hwang, Inchan; Kim, Namwoo; Choi, Deokjae; Um, Han-Don; Kim, Seungchul; Seo, Kwanyong

    2016-07-01

    We developed a unique nano- and microwire hybrid structure by selectively modifying only the tops of microwires using metal-assisted chemical etching. The proposed nano/micro hybrid structure not only minimizes surface recombination but also absorbs 97% of incident light under AM 1.5G illumination, demonstrating outstanding light absorption compared to that of planar (59%) and microwire arrays (85%). The proposed hybrid solar cells with an area of 1 cm2 exhibit power conversion efficiencies (Eff) of up to 17.6% under AM 1.5G illumination. In particular, the solar cells show a high short-circuit current density (Jsc) of 39.5 mA cm-2 because of the high light-absorbing characteristics of the nanostructures. This corresponds to an approximately 61.5% and 16.5% increase in efficiency compared to that of a planar silicon solar cell (Eff = 10.9%) and a microwire solar cell (Eff = 15.1%), respectively. Therefore, we expect the proposed hybrid structure to become a foundational technology for the development of highly efficient radial junction solar cells.We developed a unique nano- and microwire hybrid structure by selectively modifying only the tops of microwires using metal-assisted chemical etching. The proposed nano/micro hybrid structure not only minimizes surface recombination but also absorbs 97% of incident light under AM 1.5G illumination, demonstrating outstanding light absorption compared to that of planar (59%) and microwire arrays (85%). The proposed hybrid solar cells with an area of 1 cm2 exhibit power conversion efficiencies (Eff) of up to 17.6% under AM 1.5G illumination. In particular, the solar cells show a high short-circuit current density (Jsc) of 39.5 mA cm-2 because of the high light-absorbing characteristics of the nanostructures. This corresponds to an approximately 61.5% and 16.5% increase in efficiency compared to that of a planar silicon solar cell (Eff = 10.9%) and a microwire solar cell (Eff = 15.1%), respectively. Therefore, we expect the

  5. Hybrid Method for 3D Segmentation of Magnetic Resonance Images

    Institute of Scientific and Technical Information of China (English)

    ZHANGXiang; ZHANGDazhi; TIANJinwen; LIUJian

    2003-01-01

    Segmentation of some complex images, especially in magnetic resonance brain images, is often difficult to perform satisfactory results using only single approach of image segmentation. An approach towards the integration of several techniques seems to be the best solution. In this paper a new hybrid method for 3-dimension segmentation of the whole brain is introduced, based on fuzzy region growing, edge detection and mathematical morphology, The gray-level threshold, controlling the process of region growing, is determined by fuzzy technique. The image gradient feature is obtained by the 3-dimension sobel operator considering a 3×3×3 data block with the voxel to be evaluated at the center, while the gradient magnitude threshold is defined by the gradient magnitude histogram of brain magnetic resonance volume. By the combined methods of edge detection and region growing, the white matter volume of human brain is segmented perfectly. By the post-processing using mathematical morphological techniques, the whole brain region is obtained. In order to investigate the validity of the hybrid method, two comparative experiments, the region growing method using only gray-level feature and the thresholding method by combining gray-level and gradient features, are carried out. Experimental results indicate that the proposed method provides much better results than the traditional method using a single technique in the 3-dimension segmentation of human brain magnetic resonance data sets.

  6. Piezoelectric properties of the new generation active matrix hybrid (micro-nano) composites

    Science.gov (United States)

    Parali, Levent; Şabikoğlu, İsrafil; Kurbanov, Mirza A.

    2014-11-01

    A hybrid piezoelectric composite structure is obtained by addition of nano-sized BaTiO3, SiO2 to the micro-sized PZT and polymers composition. Although the PZT material itself has excellent piezoelectric properties, PZT-based composite variety is limited. Piezoelectric properties of PZT materials can be varied with an acceptor or a donor added to the material. In addition, varieties of PZT-based sensors can be increased with doping polymers which have physical-mechanical, electrophysical, thermophysical and photoelectrical properties. The active matrix hybrid structure occurs when bringing together the unique piezoelectric properties of micro-sized PZT with electron trapping properties of nano-sized insulators (BaTiO3 or SiO2), and their piezoelectric, mechanic and electromechanic properties significantly change. In this study, the relationship between the piezoelectric constant and the coupling factor values of microstructure (PZT-PVDF) and the hybrid structure (PZT-PVDF-BaTiO3) composite are compared. The d33 value and the coupling factor of the hybrid structure have shown an average of 54 and 62% increase according to microstructure composite, respectively. In addition, the d33 value and the coupling factor of the hybrid structure (PZT-HDPE-SiO2) have exhibited about 68 and 52% increase according to microstructure composite (PZT-HDPE), respectively.

  7. Polyionic hybrid nano-engineered systems comprising alginate and chitosan for antihypertensive therapeutics.

    Science.gov (United States)

    Niaz, Taskeen; Nasir, Habib; Shabbir, Saima; Rehman, Asma; Imran, Muhammad

    2016-10-01

    Hydrophobic nature of virtually all antihypertensive (AHT) drugs is the major hindrance towards their oral administration. Current study focuses on the development of polyionic hybrid nano drug delivery systems comprising sodium alginate and chitosan, loaded with distinct AHT drugs (captopril, amlodipine and valsartan). Encapsulation efficiency of hybrid NCS increased in the order of amlodipine>valsartan>captopril with average value of 42±0.9%, 91±1.5% and 96±1.9%, respectively. Scanning electron microscopy revealed hybrid NCS with smooth topography and round appearance in case of captopril. FTIR analysis confirmed the cross-linking between amino and carboxylate group of chitosan and alginate to form polyionic structures at nano-scale. Zeta-sizer experiments revealed that particle size distribution had increased from 197±12nm to 341±15nm for void and captopril loaded NCS. However, highly positive zeta potential of +32±1.6mV was not decreased significantly. In vitro sustained release assays reflected excellent retention of AHT drug in hybrid nanoparticles at 4°C and 37°C in physiological buffer, as less than 8% of the total drug was released in first 24h. Thus, carbohydrate-based hybrid NCS offering high loading capacity, stability and sustained release of hydrophobic drugs can be excellent alternative to current AHT therapeutics.

  8. Energy-efficient tunable silicon photonic micro-resonator with graphene transparent nano-heaters

    CERN Document Server

    Yu, Longhai; Dai, Daoxin; He, Sailing

    2015-01-01

    Thermally-tuning silicon micro-cavities are versatile and beneficial elements in low-cost large-scale photonic integrated circuits (PICs). Traditional metal heaters used for thermal tuning in silicon micro-cavities usually need a thick SiO2 upper-cladding layer, which will introduce some disadvantages including low response speed, low heating efficiency, low achievable temperature and complicated fabrication processes. In this paper, we propose and experimentally demonstrate thermally-tuning silicon micro-disk resonators by introducing graphene transparent nano-heaters, which contacts the silicon core directly without any isolator layer. This makes the graphene transparent nano-heater potentially to have excellent performances in terms of the heating efficiency, the temporal response and the achievable temperature. It is also shown that the graphene nano-heater is convenient to be used in ultrasmall photonic integrated devices due to the single-atom thickness and excellent flexibility of graphene. Both experi...

  9. Synthesis and characterization of guar gum templated hybrid nano silica.

    Science.gov (United States)

    Singh, V; Singh, S K; Pandey, S; Sanghi, R

    2011-08-01

    The objective of the present study was the fabrication of green adsorbent hybrids for which native guar gum was used as template to polymerize tetraethoxysilane. The properties and performances of the hybrids could be tailored by using varying molecular sizes of the partially depolymerized guar gum templates of various molecular sizes as control. Zn(II) uptake from aqueous solution was used as a criterion for evaluating the adsorbent efficiency. The optimum material (H4) in terms of maximum Zn(II) uptake, was obtained when the template size used was 375 kDa at a calcination temperature of 700°C. H4 was also evaluated for Ca(II), Mg(II), Cd(II) and Hg(II) adsorption. To explore the other applicability areas, the hybrids have been extensively characterized using FTIR, XRD, TGA-DTA, PL, SEM, TEM and BET analyses. H4 was found to be as efficient as previously reported vinyl modified-silica nanohybrids. It had a high surface area (264 m(2)/g) with silica nanoparticles in the size range of 90-140 nm. Being thermally very stable and photoluminescent, the material can be potentially used for many biological, medical and environmental applications.

  10. Multipartite Spin Entangled States in Quantum Dots with a Quantum Databus Based on Nano Electro-Mechanical Resonator

    Institute of Scientific and Technical Information of China (English)

    ZHU Zhi-Cheng; TU Tao; GUO Guo-Ping

    2011-01-01

    We propose an efficient method to create multipartite spin entangled states in quantum dots coupled to a nano electro-mechanical resonator array. Our method, based on the interaction between electron spins confined in quantum dots and the motion of magnetized nano electro-mechanical resonators, can enable a coherent spin-spin coupling over long distances and in principle be applied to an arbitrarily large number of electronic spins.%@@ We propose an efficient method to create multipartite spin entangled states in quantum dots coupled to a nano electro-mechanical resonator array.Our method, based on the interaction between electron spins confined in quantum dots and the motion of magnetized nano electro-mechanical resonators, can enable a coherent spin-spin coupling over long distances and in principle be applied to an arbitrarily large number of electronic spins.

  11. Mueller matrix polarimetry of plasmon resonant silver nano-rods: biomedical prospects

    CERN Document Server

    Ghosh, Sayantan; Bera, Sudipta K; Banerjee, Ayan; Ghosh, Nirmalya

    2012-01-01

    Fundamental understanding of the light-matter interaction in the context of nano-particles is immensely bene- fited by the study of geometry dependent tunable Localized Surface Plasmon Resonance (LSPR) and has been demonstrated to have potential applications in various areas of science. The polarization characteristics of LSPR in addition to spectroscopic tuning can be suitably exploited in such systems as contrast enhancement mech- anisms and control parameters. Such polarization characteristics like diattenuation and retardance have been studied here using a novel combination of Muller-matrix polarimetry with the T-matrix matrix approach for silver nano-rods to show unprecedented control and sensitivity to local refractive index variations. The study carried out over various aspect ratios for a constant equal volume sphere radius shows the presence of longitu- dinal (dipolar and quadrupolar) and transverse (dipolar) resonances; arising due to differential contribution of polarizabilities in two directions. ...

  12. A six-year prospective randomized study of a nano-hybrid and a conventional hybrid resin composite in Class II restorations

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2013-01-01

    The objective of this 6 year prospective randomized equivalence trial was to evaluate the long-term clinical performance of a new nano-hybrid resin composite (RC) in Class II restorations in an intraindividual comparison with its well-established conventional hybrid RC predecessor....

  13. Hertzian Load-bearing Capacity of Hybrid and Nano-hybrid Resin Composites Stored Dry and Wet

    Directory of Open Access Journals (Sweden)

    Farmani S

    2016-03-01

    Full Text Available Statement of Problem: Hertzian indentation test has been proven to be an efficient and reliable alternative upon Vickers hardness test. This method has been used to test dental ceramics, amalgams, glass ionomers and luting cements.There is limited published information about the load-bearing capacity of resin composites using Hertizian indentation test. Objectives: To investigate the load-bearing capacity of hybrid and nano-hybrid resin composites stored dry or wet up to 30 days, using Hertzian indentation test. Materials and Methods: Three resin composites were used: two nano-hybrids (Filtek Supreme, and Luna and one hybrid, (Rok. A total of 108 disc-shaped specimens (1mm thick x 10 mm diameter were prepared using polyethylene mould. The specimens of each material were randomly divided into 6 groups of 6 (n=6 and stored at 370C either in distilled water or dry for 1, 7 and 30 days. The specimens were tested using Hertzian jig aligned in the universal testing machine. The specimen was placed on the top of a disc-shaped substrate. The load was applied at the center of each specimen and the load at the first crack was recorded. Data were analyzed by ANOVA, Tukey’sand student’s t-test using SPSS version 18.0. Results: Three-way ANOVA showed a significant interaction between all the factors (p = .0001. The load bearing capacity of almost all materials reduced significantly in the wet condition in comparison with the dry condition (p = .0001. After seven days of immersion in distilled water, Filtek Supreme had significantly lower values than those of Rok and Luna, there was no significant differences between materials in the dry condition. Conclusions:In contrast to dry condition, the load-bearing capacity of specimens stored in distilled water decreased significantly over the 30 days of immersion. The load bearing capacity of nano-hybrid composites tested in this study was shown to be comparable with that of the hybrid composite.

  14. Hybrid nanostructured thin-films by PLD for enhanced field emission performance for radiation micro-nano dosimetry applications

    Energy Technology Data Exchange (ETDEWEB)

    Manikandan, E., E-mail: maniphysics@gmail.com [UNESCO-UNISA AFNET in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department, iThemba LABS–National Research Foundation (NRF), 1 Old Faure Road, Somerset West, PO Box 722, Western Cape (South Africa); Materials Science Group (MSG), Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam 603102 (India); Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam 603102 (India); Sree Balaji Medical College & Hospital (SBMCH), Bharath University, Chrompet, Chennai 600044 (India); Kennedy, J. [UNESCO-UNISA AFNET in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department, iThemba LABS–National Research Foundation (NRF), 1 Old Faure Road, Somerset West, PO Box 722, Western Cape (South Africa); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Kavitha, G. [UNESCO-UNISA AFNET in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), Materials Research Department, iThemba LABS–National Research Foundation (NRF), 1 Old Faure Road, Somerset West, PO Box 722, Western Cape (South Africa); PG& Research Dept of Physics, AM Jain College Affiliated to University of Madras, Chennai 600114 (India); and others

    2015-10-25

    We report the observation of hybrid nanostructured thin-films such as diamond-like carbon (DLC) signature on the ZnO epitaxial thin-films grown onto the device silicon/quartz substrate by reactive pulsed laser deposition (r-PLD) under the argon–oxygen (Ar|O{sub 2}) ambient at 573 K. Undoped and Carbon (C) doped epitaxial ZnO thin-film layer formation is revealed by the accelerator based ion-beam analysis (IBA) technique of resonant Rutherford backscattering spectrometry (RRBS), glancing-incidence X-ray diffraction (GIXRD) pattern, micro-Raman spectroscopy (μ-RS) and field-emission (F-E) studies. The RRBS and GIXRD results show the deposition of epitaxial thin-films containing C into ZnO. The μ-RS technique is a standard nondestructive tool (NDT) for the characterization of crystalline, nano-crystalline, and amorphous carbons (a-C). As grown ZnO and C-doped ZnO thin-films μ-RS result reveal the doping effect of C-impurities that appear in the form of DLC evident from Raman peaks at 1357 and 1575 cm{sup −1} along with a wurtzite structure peak at 438 cm{sup −1} with E{sub 2}(h) phonon of ZnO. The electron transport F-E result shows the hybrid thin-films has high conductivity than the un-doped film. Fabricated hybrid nanostructured thin-films materials could be very useful for the emerging applications of micro-nano dosimetry. - Highlights: • Observation of hybrid nanostructured diamond-like carbon (DLC) on ZnO epitaxial thin-films at 573 K. • Carbon doped epitaxial ZnO thin-film layer formation is revealed by RRBS, Micro-Raman. • Field-emission (F-E) study. • DLC formation evident from Raman peaks at 1357 and 1575 cm{sup −1} along with a wurtzite structure peak of ZnO. • The electron transport F-E result shows the hybrid thin-film has high conductivity than the undoped thin-film.

  15. Highly tunable ultra-narrow-resonances with optical nano-antenna phased arrays in the infrared

    CERN Document Server

    Li, Shi-Qiang; Guo, Peijun; Buchholz, D Bruce; Qiu, Ziwei; Ketterson, John B; Ocola, Leonidas E; Sakoda, Kazuaki; Chang, Robert P H

    2014-01-01

    We report our recent development in pursuing high Quality-Factor (high-Q factor) plasmonic resonances, with vertically aligned two dimensional (2-D) periodic nanorod arrays. The 2-D vertically aligned nano-antenna array can have high-Q resonances varying arbitrarily from near infrared to terahertz regime, as the antenna resonances of the nanorod are highly tunable through material properties, the length of the nanorod, and the orthogonal polarization direction with respect to the lattice surface,. The high-Q in combination with the small optical mode volume gives a very high Purcell factor, which could potentially be applied to various enhanced nonlinear photonics or optoelectronic devices. The 'hot spots' around the nanorods can be easily harvested as no index-matching is necessary. The resonances maintain their high-Q factor with the change of the environmental refractive index, which is of great interest for molecular sensing.

  16. Hybrid Continuum and Molecular Modeling of Nano-scale Flows

    Science.gov (United States)

    Povitsky, Alex; Zhao, Shunliu

    2010-11-01

    A novel hybrid method combining the continuum approach based on boundary singularity method (BSM) and the molecular approach based on the direct simulation Monte Carlo (DSMC) is developed and then used to study viscous fibrous filtration flows in the transition flow regime, Kn>0.25. The DSMC is applied to a Knudsen layer enclosing the fiber and the BSM is employed to the entire flow domain. The parameters used in the DSMC and the coupling procedure, such as the number of simulated particles, the cell size and the size of the coupling zone are determined. Results are compared to the experiments measuring pressure drop and flowfield in filters. The optimal location of singularities outside of flow domain was determined and results are compared to those obtained by regularized Stokeslets. The developed hybrid method is parallelized by using MPI and extended to multi-fiber filtration flows. The multi-fiber filter flows considered are in the partial-slip and transition regimes. For Kn˜1, the computed velocity near fibers changes significantly that confirms the need of molecular methods in evaluation of the flow slip in transitional regime.

  17. Magnetic resonance imaging by using nano-magnetic particles

    Energy Technology Data Exchange (ETDEWEB)

    Shokrollahi, H., E-mail: Shokrollahi@sutech.ac.ir [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Khorramdin, A. [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Isapour, Gh. [Department of Materials and Engineering, Hakim Sabzevari University (Iran, Islamic Republic of)

    2014-11-15

    Magnetism and magnetic materials play a major role in various biological applications, such as magnetic bioseparation, magnetic resonance imaging (MRI), hyperthermia treatment of cancer and drug delivery. Among these techniques, MRI is a powerful method not only for diagnostic radiology but also for therapeutic medicine that utilizes a magnetic field and radio waves. Recently, this technique has contributed greatly to the promotion of the human quality life. Thus, this paper presents a short review of the physical principles and recent advances of MRI, as well as providing a summary of the synthesis methods and properties of contrast agents, like different core materials and surfactants. - Highlights: • This paper studies the physics of MRI as a powerful diagnostic technique. • MRI uses the differentiation between healthy and pathological tissues. • The relaxation times can be shortened by the use of a magnetic contrast agent. • The magnetic nanoparticles act as contrast agents, helping to increase the resolution. • Different synthesis methods can influence the magnetic resonance behavior.

  18. Few layered vanadyl phosphate nano sheets-MWCNT hybrid as an electrode material for supercapacitor application

    Science.gov (United States)

    Dutta, Shibsankar; De, Sukanta

    2016-05-01

    It have been already seen that 2-dimensional nano materials are the suitable choice for the supercapacitor application due to their large specific surface area, electrochemical active sites, micromechanical flexibility, expedite ion migration channel properties. Free standing hybrid films of functionalized MWCNT (- COOH group) and α-Vanadyl phosphates (VOPO42H2O) are prepared by vacuum filtering. The surface morphology and microstructure of the samples are studied by transmission electron microscope, field emission scanning electron microscope, XRD, Electrochemical properties of hybrid films have been investigated systematically in 1M Na2SO4 aqueous electrolyte. The hybrid material exhibits a high specific capacitance 236 F/g with high energy density of 65.6 Wh/Kg and a power density of 1476 W/Kg.

  19. Analysis of a log periodic nano-antenna for multi-resonant broadband field enhancement and the Purcell factor

    Science.gov (United States)

    Yang, Jie; Kong, Fanmin; Li, Kang; Sheng, Shiwei

    2015-05-01

    Broadband nano-antennas play a central role in many areas of science and technology. However, a more intuitive understanding for rational design of nano-antennas with broadband response is desirable. A log periodic nano-antenna was studied in the paper. The finite-difference time-domain method was used to explore the spectral characteristics of the log periodic nano-antenna by the excitation mode of reception and emission. The effects of geometry on field enhancement and the Purcell factor were systematically described and investigated. The field enhancement of the nano-antenna can be tuned by geometric parameters such as the outer radius, the tooth angle, and the ratio of the radial sizes of successive teeth, which provide control over both the spectral resonance position and the field enhancement peak amplitude. The Purcell factor mainly depends on the outer radius, the tooth angle, and the bow angle. In addition, multi-resonant field enhancement was analyzed in detail by conformal transformation. Furthermore, a careful comparison of the characteristics of a bowtie nano-antenna demonstrated that the log periodic nano-antenna has considerable potential for multi-resonant field enhancement and improvement of the Purcell factor. The results provide a promising prospect for designing and optimizing the log periodic nano-antenna in a broad range of wavelengths.

  20. Active coated nano-particle excited by an arbitrarily located electric Hertzian dipole — resonance and transparency effects

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Ziolkowski, Richard W.

    2010-01-01

    The present work investigates the optical properties of active coated spherical nano-particles excited by an arbitrarily located electric Hertzian dipole. The nano-particles are made of specific dielectric and plasmonic materials. The spatial near-field distribution as well as the normalized...... radiation resistance is examined. Both enhanced as well as reduced radiation effects are demonstrated. In particular, it is shown that specific active coated nano-particles can be designed to be resonant, leading to much larger values of the normalized radiation resistance than is the case...... with the corresponding passive coated nano-particles, thereby overcoming the intrinsic losses present in the plasmonic materials. Moreover, it is shown that other active coated nano-particle designs can significantly reduce the normalized radiation resistance; thus both the resonant as well as non...

  1. Preparation, characterization and antimicrobial property of ag+- nano Chitosan/ZSM-5: novel Hybrid Biocomposites

    Directory of Open Access Journals (Sweden)

    Maasoumeh Khatamiana

    2016-10-01

    Full Text Available Objective(s: Binary hybrids of chitosan-zeolite have many interesting applications in separation and bacteriostatic activity. Materials and Methods: Template free ZSM-5 zeolite was synthesized by hydrothermal method, physical hydrogels of nano chitosan in the colloidal domain were obtained in the absence of toxic organic solvent and then nano chitosan/ZSM-5 hybrid composites with nano chitosan contents of 0.35%, 3.5%, 35% wt.% were prepared. The as prepared hybrid composites were ion-exchanged with Ag cations. Results: XRD and FT-IR results revealed a good crystalinity of as synthesized template frees ZSM-5 with BET surface area of 307 m2g-1. Presence of chitosan in composites was confirmed by XRD patterns and FT-IR spectroscopic analysis, the chitosan content in composite was obtained with TG analysis. SEM analysis of composites shows that chitosan particles were dispersed within the nanometer scale. The antimicrobial activity of different samples was investigated and the results showed that the Ag+-exchanged samples have the highest antibacterial properties. Cancer cell line A549 cell line were cultured in designated medium treated with Ag+-exchanged samples at the concentration of 0.01 to 0.5 mg/ml. After 24 and 48 hours incubation, the efficacy of Ag+-exchanged samples to treat cancer cell lines were measured by means of cell viability test via MTT assay. Concentrations of 0.05 and 0.1 mg/ml of Ag+-exchanged samples induced a very low toxicity. Conclusion: These hybrid composite materials have potential applications on tissue engineering and antimicrobial food packaging.

  2. Improving the physical properties of starch using a new kind of water dispersible nano-hybrid reinforcement.

    Science.gov (United States)

    Morales, Noé J; Candal, Roberto; Famá, Lucía; Goyanes, Silvia; Rubiolo, Gerardo H

    2015-08-20

    Plasticized cassava starch matrix composites reinforced by a multi-wall carbon nanotube (MWCNT)-hercynite (FeAl2O4) nanomaterial were developed. The hybrid nanomaterial consists of FeAl2O4 nanoparticles anchored strongly to the surface of the MWCNT. This nano-hybrid filler shows an irregular geometry, which provides a strong mechanical interlocking with the matrix, and excellent stability in water, ensuring a good dispersion in the starch matrix. The composite containing 0.04wt.% of the nano-hybrid filler displays increments of 370% in the Young's modulus, 138% in tensile strength and 350% in tensile toughness and a 70% decrease in water vapor permeability relative to the matrix material. All of these significant improvements are explained in terms of the nano-hybrid filler homogenous dispersion and its high affinity with both plasticizers, glycerol and water, which induces crystallization without deterioration of the tensile toughness.

  3. Nano- and micro-structured silicon for hybrid near-infrared photodetectors

    Science.gov (United States)

    Äńerek, V.; Głowacki, E. D.; Bednorz, M.; Demchyshyn, S.; Sariciftci, N. S.; Ivanda, M.

    2016-05-01

    Structuring surface and bulk of crystalline silicon on different length scales can significantly alter its properties and possibly improve the performance of opto-electronic devices and sensors based on silicon. Different dominant feature scales are responsible for modification of some of electronic and optical properties of silicon. Several easily reproducible chemical methods for facile structuring of silicon on nano and micro-scales, based on both electroless and anodic etching of silicon in hydrofluoric acid based etchants, and chemical anisotropic etching of silicon in basic environments, are presented. We show how successive micro and nano structuring creates hierarchical silicon surfaces, which can be used to simultaneously exploit the advantages of both structuring feature length scales. Finally, we demonstrate a large increase in photocurrent obtained from a hybrid structured silicon/organic near-infrared photodetector. Improved silicon/6,6'-dibromoindigo hybrid photodiodes were prepared by nano- and micro-structuring the silicon part of the heterojunction by wet chemical etching methods. Photocurrent and spectral responsivity were improved in comparison to planar diodes by up to two orders of magnitude by optimization of the silicon structuring process. We show that the improvement in photocurrent is not due to the increase in surface area or light trapping.

  4. Fabrication of Nano-Micro Hybrid Structures by Replication and Surface Treatment of Nanowires

    Directory of Open Access Journals (Sweden)

    Yeonho Jeong

    2017-07-01

    Full Text Available Nanowire structures have attracted attention in various fields, since new characteristics could be acquired in minute regions. Especially, Anodic Aluminum Oxide (AAO is widely used in the fabrication of nanostructures, which has many nanosized pores and well-organized nano pattern. Using AAO as a template for replication, nanowires with a very high aspect ratio can be fabricated. Herein, we propose a facile method to fabricate a nano-micro hybrid structure using nanowires replicated from AAO, and surface treatment. A polymer resin was coated between Polyethylene terephthalate (PET and the AAO filter, roller pressed, and UV-cured. After the removal of aluminum by using NaOH solution, the nanowires aggregated to form a micropattern. The resulting structure was subjected to various surface treatments to investigate the surface behavior and wettability. As opposed to reported data, UV-ozone treatment can enhance surface hydrophobicity because the UV energy affects the nanowire surface, thus altering the shape of the aggregated nanowires. The hydrophobicity of the surface could be further improved by octadecyltrichlorosilane (OTS coating immediately after UV-ozone treatment. We thus demonstrated that the nano-micro hybrid structure could be formed in the middle of nanowire replication, and then, the shape and surface characteristics could be controlled by surface treatment.

  5. Effect of size on the chaotic behavior of nano resonators

    Science.gov (United States)

    Alemansour, Hamed; Miandoab, Ehsan Maani; Pishkenari, Hossein Nejat

    2017-03-01

    Present study is devoted to investigate the size effect on chaotic behavior of a micro-electro-mechanical resonator under external electrostatic excitation. Using Galerkin's decomposition method, approximating the actuation force with a new effective lumped model, and neglecting higher order terms in the Taylor-series expansion, a simplified model of the main system is developed. By utilizing the Melnikov's method and based on the new form of the electrostatic force, an expression in terms of the system parameters is developed which can be used to rapidly estimate the chaotic region of the simplified system. Based on the analysis of the simple proposed model, it is shown that the effect of size on chaotic region varies significantly depending on bias voltage. By considering the size effect, it is demonstrated that chaotic vibration initiates at much higher constant voltages than predicted by classical theories; and, in high constant voltages, it is shown that strain gradient theory predicts occurrence of chaos at much lower amplitudes.

  6. Nano-SiO2表面处理及原位聚合法制备PI/Nano-SiO2杂化膜%Surface Modification of Nano-SiO2 and Preparation of PI/Nano-SiO2 Hybrid Films by In-Situ Polymerization

    Institute of Scientific and Technical Information of China (English)

    朱亚辉; 许馨文; 陈汉森; 左晓兵

    2011-01-01

    Nano-SiO2进行两次表面处理,然后进行原位聚合制备聚酰胺酸/Nano-SiO2悬浮液,涂膜并热亚胺化得到PI/Nano-SiO2杂化膜.对Nano-SiO2的表面处理效果进行评价,对聚酰胺酸/Nano-SiO2悬浮液的稳定性、PI/Nano-SiO2杂化膜的性能进行测试.结果表明:Nano-SiO2的二次表面处理均为化学键合;聚酰胺酸/Nano-SiO2悬浮液稳定时间达到60 d,并获得了性能优异的PI/Nano-SiO2杂化膜.%Nano-SiO2 was surface treated twice, then polyamide acid/nano-SiO2 suspension was prepared using in-situ polymerization, finally, the thermal imidization was used to get PI/nano-SiO2 hybrid films. The effect of surface treated modification of nano-SiO2 was evaluated. The stability of polyamide acid/nano-SiO2 suspension and the performance of PI/nano-SiO2 hybrid films were investigated. The results showed: all the twice surface modifications of nano-SiO2 were chemical bond; The stabilization time of polyamide acid/nano-SiO2 suspension reached to 60 days and the PI/nano-SiO2 hybrid films with excellent performances were acquired.

  7. Cross-polarization coupling and switching in an open nano-meta-resonator

    Science.gov (United States)

    Szabelak, W.; Nasalski, W.

    2011-11-01

    We demonstrate the reconfiguration process of optical beam fields circulating in an open nano-meta-resonator cavity. The cavity is composed of four corners or quadrants of space filled alternatively with dielectric and metamaterial media. The media are assumed to be lossless, nondispersive and of parameters precluding impedance matching at the boundaries between the subsequent corners. Beam path retracement in the cavity is obtained from a resonance condition of phase compensation along each optical ray contributed to the circulating beam. Cross-polarization coupling between TM and TE components of elegant higher-order Hermite-Gaussian beams propagating in the resonator is analysed. The existence of the phenomena of beam excitation, filtering and switching predicted on these grounds is explicitly confirmed by numerical simulations. All phenomena described depend substantially on a field cross-sectional diameter of the circulating beams.

  8. Hybrid Plasmonic Waveguide Fed Broadband Nano-antenna for Nanophotonic Applications

    CERN Document Server

    Saad-Bin-Alam, Md; Rahman, Atiqur; Chowdhury, Arshad M

    2014-01-01

    In this paper, we propose a novel hybrid plasmonic waveguide fed broadband optical patch nano-antenna for nanophotonic applications. Through full wave electromagnetic simulation, we demonstrated our proposed antenna to radiate and receive signal at all optical communication windows (e.g. $\\lambda$ = 850nm, 1310nm & 1550nm) with around 86% bandwidth within the operational domain. Moreover numerical results demonstrate that the proposed nano-antenna has directional radiation pattern with satisfactory gain over all three communication bands. Additionally, we evaluated the antenna performances with two different array arrangements (e.g. one dimensional and square array). The proposed broadband antenna can be used for prominent nanophotonic applications such as optical wireless communication in inter and intra-chip devices, optical sensing and optical energy harvesting etc.

  9. Electrical properties of NiO/PVC nano hybrid composites for organic field effect transistors

    Science.gov (United States)

    Hayati, A.; Bahari, A.

    2015-01-01

    In this study, NiO/PVC nano hybrid composites have been synthesized through sol-gel method. Nano crystallites phases, crystallinity and electrical properties have been characterized using X-ray diffraction, Fourier transfer infrared radiation, scanning electron microscopy and atomic force microscopy techniques. The dielectric constant of the samples has been calculated through measuring the capacity of samples by application of GPS 132 A. Obtained results have indicated that an NiO/PVC sample with 5 g NiO and 0.02 g PVC, equivalent to 0.4 %wt PVC, in weight synthesis, at a temperature of 80 °C has a higher dielectric constant, better surface morphology, less rough surface, less leakage current, and thus has potential to be suggested as a possible gate dielectric material for future organic field effect transistor devices.

  10. Anti-inflammatory drug incorporation into polymeric nano-hybrids for local controlled release.

    Science.gov (United States)

    Sammartino, G; Marenzi, G; Tammaro, L; Bolognese, A; Calignano, A; Costantino, U; Califano, L; Mastrangelo, F; Tetè, S; Vittoria, V

    2005-01-01

    In this paper we present the formulation, preparation and characterization of new polymeric composite materials containing a nano-hybrid to be used for the controlled molecular delivery of an anti-inflammatory molecule, Diclofenac. The nano-hybrid consists of a layer of double hydroxide of an Mg-Al hydrotalcite type, in which we replaced the chloride anions present in the host galleries with Diclofenac anions by a simple ion-exchange reaction. Different amounts of the hybrid material were incorporated in polycaprolactone and processed as films of 0.15 mm thickness. The composite materials were analyzed by X-ray diffractometry, thermogravimetry and for their mechanical properties, and showed properties even better than those for the pristine polymer. The release process of the anti-inflammatory molecules was very interesting and promising for tuneable drug delivery. It consists of two stages: a first stage, very rapid as a burst in which a small fraction of the drug is released, and of a second stage that is much slower, extending for longer and longer periods. The parameters influencing the drug release were individuated and discussed.

  11. A Review on Potentiality of Nano Filler/Natural Fiber Filled Polymer Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Naheed Saba

    2014-08-01

    Full Text Available The increasing demand for greener and biodegradable materials leading to the satisfaction of society requires a compelling towards the advancement of nano-materials science. The polymeric matrix materials with suitable and proper filler, better filler/matrix interaction together with advanced and new methods or approaches are able to develop polymeric composites which shows great prospective applications in constructions and buildings, automotive, aerospace and packaging industries. The biodegradability of the natural fibers is considered as the most important and interesting aspects of their utilization in polymeric materials. Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid bio-based composites that exploit the synergy between natural fibers in a nano-reinforced bio-based polymer can lead to improved properties along with maintaining environmental appeal. This review article intended to present information about diverse classes of natural fibers, nanofiller, cellulosic fiber based composite, nanocomposite, and natural fiber/nanofiller-based hybrid composite with specific concern to their applications. It will also provide summary of the emerging new aspects of nanotechnology for development of hybrid composites for the sustainable and greener environment.

  12. Investigation based on nano-electromechanical system double Si3N4 resonant beam pressure sensor.

    Science.gov (United States)

    Yang, Chuan; Guo, Can; Yuan, Xiaowei

    2011-12-01

    This paper presents a type of NEMS (Nano-Electromechanical System) double Si3N4 resonant beams pressure sensor. The mathematical models are established in allusion to the Si3N4 resonant beams and pressure sensitive diaphragm. The distribution state of stress has been analyzed theoretically based on the mathematical model of pressure sensitive diaphragm; from the analysis result, the position of the Si3N4 resonant beams above the pressure sensitive diaphragm was optimized and then the dominance observed after the double resonant beams are adopted is illustrated. From the analysis result, the position of the Si3N4 resonant beams above the pressure sensitive diaphragm is optimized, illustrating advantages in the adoption of double resonant beams. The capability of the optimized sensor was generally analyzed using the ANSYS software of finite element analysis. The range of measured pressure is 0-400 Kpa, the coefficient of linearity correlation is 0.99346, and the sensitivity of the sensor is 498.24 Hz/Kpa, higher than the traditional sensors. Finally the processing techniques of the sensor chip have been designed with sample being successfully processed.

  13. Hybrid polaritons in a resonant inorganic/organic semiconductor microcavity

    Energy Technology Data Exchange (ETDEWEB)

    Höfner, M., E-mail: mhoefner@physik.hu-berlin.de; Sadofev, S.; Henneberger, F. [Institut für Physik, Humboldt-Universität zu Berlin, Newtonstr.15, 12489 Berlin (Germany); Kobin, B.; Hecht, S. [Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin (Germany)

    2015-11-02

    We demonstrated the strong coupling regime in a hybrid inorganic-organic microcavity consisting of (Zn,Mg)O quantum wells and ladder-type oligo(p-phenylene) molecules embedded in a polymer matrix. A Fabry-Pérot cavity is formed by an epitaxially grown lower ZnMgO Bragg reflector and a dielectric mirror deposited atop of the organic layer. A clear anticrossing behavior of the polariton branches related to the Wannier-Mott and Frenkel excitons, and the cavity photon mode with a Rabi-splitting reaching 50 meV, is clearly identified by angular-dependent reflectivity measurements at low temperature. By tailoring the structural design, an equal mixing with weights of about 0.3 for all three resonances is achieved for the middle polariton branch at an incidence angle of about 35°.

  14. Enhancement of hybrid rocket combustion performance using nano-sized energetic particles

    Science.gov (United States)

    Risha, Grant Alexander

    Until now, the regression rate of classical hybrid rocket engines have typically been an order of magnitude lower than solid propellant motors; thus, hybrids require a relatively large fuel surface area for a given thrust level. In addition to low linear regression rates, relatively low combustion efficiency (87 to 92%), low mass burning rates, varying oxidizer-to-fuel ratio during operation, and lack of scaling laws have been reported. These disadvantages can be ameliorated by introducing nano-sized energetic powder additives into the solid fuel. The addition of nano-sized energetic particles into the solid fuel enhances performance as measured by parameters such as: density specific impulse, mass and linear burning rates, and thrust. Thermophysical properties of the solid fuel such as density, heat of combustion, thermal diffusivity, and thermal conductivity are also enhanced. The types of nano-sized energetic particles used in this study include aluminum, boron, boron carbide, and some Viton-A coated particles. Since the combustion process of solid fuels in a hybrid rocket engine is governed by the mass flux of the oxidizer entering the combustion chamber, the rate-limiting process is the mixing and reacting of the pyrolysis products of the fuel grain with the incoming oxidizer. The overall goal of this research was to determine the relative propulsive and combustion behavior for a family of newly-developed HTPB-based solid-fuel formulations containing various nano-sized energetic particles. Seventeen formulations contained 13% additive by weight, one formulation (SF4) contained 6.5% additive by weight, and one formulation (SF19) contained 5.65% boron by weight. The two hybrid rocket engines which were used in this investigation were the Long Grain Center-Perforated (LGCP) rocket engine and the X-Ray Transparent Casing (XTC) rocket engine. The smaller scale LGCP rocket engine was used to evaluate all of the formulations because conducting experiments using the

  15. Manipulating Fano resonance via fs-laser melting of hybrid oligomers at nanoscale

    Science.gov (United States)

    Lepeshov, S. I.; Zuev, D. A.; Makarov, S. V.; Milichko, V. A.; Mukhin, I. S.; Krasnok, A. E.; Belov, P. A.

    2016-08-01

    Here, the novel concept of asymmetric metal-dielectric (hybrid) nanoparticles is proposed. The experimental data and the results of numerical simulation of the optical properties of hybrid nanostructures are presented. The change of their optical response after fs- laser modification is shown. The possibility of manipulating Fano resonance in hybrid oligomers by the gold nanoparticles reshaping is demonstrated.

  16. Resonant frequency calculations using a hybrid perturbation-Galerkin technique

    Science.gov (United States)

    Geer, James F.; Andersen, Carl M.

    1991-01-01

    A two-step hybrid perturbation Galerkin technique is applied to the problem of determining the resonant frequencies of one or several degrees of freedom nonlinear systems involving a parameter. In one step, the Lindstedt-Poincare method is used to determine perturbation solutions which are formally valid about one or more special values of the parameter (e.g., for large or small values of the parameter). In step two, a subset of the perturbation coordinate functions determined in step one is used in Galerkin type approximation. The technique is illustrated for several one degree of freedom systems, including the Duffing and van der Pol oscillators, as well as for the compound pendulum. For all of the examples considered, it is shown that the frequencies obtained by the hybrid technique using only a few terms from the perturbation solutions are significantly more accurate than the perturbation results on which they are based, and they compare very well with frequencies obtained by purely numerical methods.

  17. Hybrid circuit cavity quantum electrodynamics with a micromechanical resonator.

    Science.gov (United States)

    Pirkkalainen, J-M; Cho, S U; Li, Jian; Paraoanu, G S; Hakonen, P J; Sillanpää, M A

    2013-02-14

    Hybrid quantum systems with inherently distinct degrees of freedom have a key role in many physical phenomena. Well-known examples include cavity quantum electrodynamics, trapped ions, and electrons and phonons in the solid state. In those systems, strong coupling makes the constituents lose their individual character and form dressed states, which represent a collective form of dynamics. As well as having fundamental importance, hybrid systems also have practical applications, notably in the emerging field of quantum information control. A promising approach is to combine long-lived atomic states with the accessible electrical degrees of freedom in superconducting cavities and quantum bits (qubits). Here we integrate circuit cavity quantum electrodynamics with phonons. Apart from coupling to a microwave cavity, our superconducting transmon qubit, consisting of tunnel junctions and a capacitor, interacts with a phonon mode in a micromechanical resonator, and thus acts like an atom coupled to two different cavities. We measure the phonon Stark shift, as well as the splitting of the qubit spectral line into motional sidebands, which feature transitions between the dressed electromechanical states. In the time domain, we observe coherent conversion of qubit excitation to phonons as sideband Rabi oscillations. This is a model system with potential for a quantum interface, which may allow for storage of quantum information in long-lived phonon states, coupling to optical photons or for investigations of strongly coupled quantum systems near the classical limit.

  18. Wide wavelength range tunable one-dimensional silicon nitride nano-grating guided mode resonance filter based on azimuthal rotation

    OpenAIRE

    Ryoji Yukino; Pankaj K. Sahoo; Jaiyam Sharma; Tsukasa Takamura; Joby Joseph; Adarsh Sandhu

    2017-01-01

    We describe wavelength tuning in a one dimensional (1D) silicon nitride nano-grating guided mode resonance (GMR) structure under conical mounting configuration of the device. When the GMR structure is rotated about the axis perpendicular to the surface of the device (azimuthal rotation) for light incident at oblique angles, the conditions for resonance are different than for conventional GMR structures under classical mounting. These resonance conditions enable tuning of the GMR peak position...

  19. Nano Metal-Organic Framework-Derived Inorganic Hybrid Nanomaterials: Synthetic Strategies and Applications.

    Science.gov (United States)

    Mai, Hien Duy; Rafiq, Khezina; Yoo, Hyojong

    2016-11-11

    Nano- (or micro-scale) metal-organic frameworks (NMOFs), also known as coordination polymer particles (CPPs), have received much attention because of their structural diversities and tunable properties. Besides the direct use, NMOFs can be alternatively used as sacrificial templates/precursors for the preparation of a wide range of hybrid inorganic nanomaterials in straightforward and controllable manners. Distinct advantages of using NMOF templates are correlated to their structural and functional tailorability at molecular levels that is rarely acquired in any other conventional template/precursor. In addition, NMOF-derived inorganic nanomaterials with distinct chemical and physical properties are inferred to dramatically expand the scope of their utilization in many fields. In this review, we aim to provide readers with a comprehensive summary of recent progress in terms of synthetic approaches for the production of diverse inorganic hybrid nanostructures from as-synthesized NMOFs and their promising applications.

  20. Rotational characteristics in the resonance state of the HTSC-permanent magnet hybrid magnetic bearing

    Energy Technology Data Exchange (ETDEWEB)

    Morii, Y.; Sukedai, M. [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan); Ohashi, S., E-mail: ohashi@kansai-u.ac.jp [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan)

    2011-11-15

    The hybrid magnetic bearing has been developed. In the hybrid system, effect of the pinning force becomes smaller. Influence of the vibration and the gradient angle in the resonance state is large. The resonance frequency becomes small in the hybrid bearing system. The hybrid magnetic bearing using permanent magnets and the high-Tc bulk superconductor (HTSC) has been developed. Repulsive force of the permanent magnet is introduced to increase the load weight of the magnetic bearing. Effect of the hybrid system has been shown. In this paper, influence of the hybrid system on the dynamic characteristics of the rotor is studied. The rotational characteristics in the mechanical resonance state are studied, and the equivalent magnetic spring coefficient is estimated from the experimental results of the load weight. The resonance frequency is measured by the rotation experiments. The rotor achieves stable levitation even in the resonance state. In the hybrid system, effect of the pinning force becomes smaller than that of the lateral force generated by the repulsive force between the two permanent magnets at the smaller air gap. Thus influence of the lateral vibration and the gradient angle in the resonance state becomes larger at a smaller air gap. The equivalent magnetic spring coefficient becomes also small, and the resonance frequency becomes small in the hybrid bearing system.

  1. Theory of Electro-optic Modulation via a Quantum Dot Coupled to a Nano-resonator

    CERN Document Server

    Majumdar, Arka; Faraon, Andrei; Vuckovic, Jelena

    2009-01-01

    In this paper, we analyze the performance of an electro-optic modulator based on a single quantum dot strongly coupled to a nano-resonator, where electrical control of the quantum dot frequency is achieved via quantum confined Stark effect. Using realistic system parameters, we show that modulation speeds of a few tens of GHz are achievable with this system, while the energy per switching operation can be as small as 0.5 fJ. In addition, we study the non-linear distortion, and the effect of pure quantum dot dephasing on the performance of the modulator.

  2. Resonance-like Goos-Haenchen shift induced by nano-metal films

    Energy Technology Data Exchange (ETDEWEB)

    Gruschinski, R.; Stahlhofen, A.A. [Institut fuer Integrierte Naturwissenschaften, Universitaet Koblenz (Germany); Nimtz, G. [II. Physikalisches Institut, Universitaet zu Koeln (Germany)

    2008-12-15

    The influence of nano-metal films on the Goos-Haenchen shift (GHS) is investigated. The films were deposited at the total reflecting surface of a perspex prism and had a sheet resistance varying between Z{sub {open_square}}=25 and 3000 {omega}. A resonance-like enhancement of the shift and of the absorption is found for TE polarized waves, when the sheet resistance approached the value of the vacuum impedance. For TM waves the influence of the metal films on the GHS was marginal. The experiments were carried out with microwaves. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  3. Controlling Light-Matter Interaction in Semiconductors with Hybrid Nano-Structures

    Science.gov (United States)

    Gehl, Michael R.

    Nano-structures, such as photonic crystal cavities and metallic antennas, allow one to focus and store optical energy into very small volumes, greatly increasing light-matter interactions. These structures produce resonances which are typically characterized by how well they confine energy both temporally (quality factor -- Q) and spatially (mode volume -- V). In order to observe non-linear effects, modified spontaneous emission (e.g. Purcell enhancement), or quantum effects (e.g. vacuum Rabi splitting), one needs to maximize the ratio of Q/V while also maximizing the coupling between the resonance and the active medium. In this dissertation I will discuss several projects related by the goal of controlling light-matter interactions using such nano-structures. In the first portion of this dissertation I will discuss the deterministic placement of self-assembled InAs quantum dots, which would allow one to precisely position an optically-active material, for maximum interaction, inside of a photonic crystal cavity. Additionally, I will discuss the use of atomic layer deposition to tune and improve both the resonance wavelength and quality factor of silicon based photonic crystal cavities. Moving from dielectric materials to metals allows one to achieve mode-volumes well below the diffraction limit. The quality factor of these resonators is severely limited by Ohmic loss in the metal; however, the small mode-volume still allows for greatly enhanced light-matter interaction. In the second portion of this dissertation I will investigate the coupling between an array of metallic resonators (antennas) and a nearby semiconductor quantum well. Using time-resolved pump-probe measurements I study the properties of the coupled system and compare the results to a model which allows one to quantitatively compare various antenna geometries.

  4. Understanding supercapacitors based on nano-hybrid materials with interfacial conjugation

    Institute of Scientific and Technical Information of China (English)

    George Z. Chen

    2013-01-01

    The recent fast development of supercapacitors, also known scientifically as electrochemical capacitors, has benefited significantly from synthesis, characterisations and electrochemistry of nanoma-terials. Herein, the principle of supercapacitors is explained in terms of performance characteristics and charge storage mechanisms, i.e. double layer (or interfacial) capacitance and pseudo-capacitance. The semiconductor band model is applied to qualitatively account for the pseudo-capacitance in association with rectangular cyclic voltammograms (CVs) and linear galvanostatic charging and discharging plots (GCDs), aiming to differentiate supercapacitors from rechargeable batteries. The invalidity of using peak shaped CVs and non-linear GCDs for capacitance measurement is highlighted. A selective review is given to the nano-hybrid materials between carbon nanotubes and redox active materials such as electronically conducting polymers and transition metal oxides. A new concept,“interfacial conjugation”, is introduced to reflect the capacitance enhancement resulting from π-π stacking interactions at the interface between two materials with highly conjugated chemical bonds. The prospects of carbon nanotubes and graphenes for supercapacitor applications are briefly compared and discussed. Hopefully, this article can help readers to understand supercapacitors and nano-hybrid materials so that further developments in materials design and synthesis, and device engineering can be more efficient and objective.

  5. Effect of different polishing systems on the surface roughness of nano-hybrid composites

    Directory of Open Access Journals (Sweden)

    Brijesh Patel

    2016-01-01

    Full Text Available Objective: The study aimed to investigate the influence of different polishing systems on the surface roughness of nano-hybrid composite resins. Background: Different shapes of polishing systems are available according to the site of work. To minimize variability, a new system with single shape is developed that can be utilized in both anterior as well as posterior teeth. Materials and Methods: Seventy composite discs were fabricated using Teflon well (10 mm × 3 mm. Two main group of nano-hybrid composite Group I - Filtek Z350 and Group II - Tetric N-Ceram were used (n = 35 for each group. Both groups were further divided into four subgroups. Subgroup a - OneGloss (n = 10, Subgroup b - PoGo (n = 10, Subgroup c - Sof-Lex spiral (n = 10, Subgroup d - Mylar strip (control, n = 5. Samples were polished according to the manufacturer′s recommendations. Surface roughness test was performed using contact profilometer. The obtained data were analyzed using the one-way analysis of variance test. Result: Tetric N-Ceram produced smoother surfaces than Filtek Z350 (P < 0.05. Mylar strip and "PoGo" created equally smooth surfaces, while significantly rougher surfaces were obtained after applications of "Sof-Lex spiral" and "OneGloss" (P < 0.05. Conclusion: Polishing ability of Tetric N-Ceram is better than Filtek Z350 XT. "PoGo" seems to be a better polishing system than "OneGloss" and "Sof-Lex Spiral."

  6. Preparation of layered double hydroxide/chlorophyll a hybrid nano-antennae: a key step.

    Science.gov (United States)

    Sommer Márquez, Alicia E; Lerner, Dan A; Fetter, Geolar; Bosch, Pedro; Tichit, Didier; Palomares, Eduardo

    2014-07-21

    In the first step to obtain an efficient nano-antenna in a bottom-up approach, new hybrid materials were synthesized using a set of layered double hydroxides (LDHs) with basic properties and pure chlorophyll a (Chl a). The stability of the adsorbed monolayer of Chl a was shown to be dependent on the nature and the ratio of the different metal ions present in the LDHs tested. The hybrid materials turned out to be adequate for stabilizing Chl a on Mg/Al LDHs for more than a month under ambient conditions while a limited catalytic decomposition was observed for the Ni/Al LDHs leading to the formation of pheophytin. These changes were followed by namely XRD, DR-UV-vis and fluorescence spectroscopies of the hybrid antennae and of the solutions obtained from their lixiviation with acetone or diethylether. On Mg/Al hydrotalcites the stability of the adsorbed Chl a was equivalent for values of the metal atom ratio ranging from 2 to 4. The latter hybrids should constitute a good basis to form efficient nanoscale light harvesting units following intercalation of selected dyes. This work describes an efficient preparation of Chl a that allows scale-up as well as the obtention of a stable Chl a monolayer on the surface of various LDHs.

  7. Carbon nano-strings as reporters in lateral flow devices for DNA sensing by hybridization.

    Science.gov (United States)

    Kalogianni, Despina P; Boutsika, Lemonia M; Kouremenou, Panagiota G; Christopoulos, Theodore K; Ioannou, Penelope C

    2011-05-01

    Presently, there is a growing interest in the development of lateral flow devices for nucleic acid analysis that enable visual detection of the target sequence (analyte) while eliminating several steps required for pipetting, incubation, and washing out the excess of reactants. In this paper, we present, for the first time, lateral flow tests exploiting oligonucleotide-functionalized and antibody-functionalized carbon nanoparticles (carbon nano-strings, CBNS) as reporters that enable confirmation of the target DNA sequence by hybridization. The CBNS reporters were applied to (a) the detection of PCR products and (b) visual genotyping of single nucleotide polymorphisms in human genomic DNA. Biotinylated PCR product was hybridized with a dA-tailed probe. In one assay configuration, the hybrid is captured at the test zone of the strip by immobilized streptavidin and detected by (dT)(30)-CBNS. In a second configuration, the hybrids are captured from immobilized (dA) strands and detected by antibiotin-CBNS. As low as 2.5 fmol of amplified DNA can be detected. For visual genotyping, allele-specific primers with a 5' oligo(dA) segment are extended by DNA polymerase with a concomitant incorporation of biotin moieties. Extension products are detected either by (dT)(30)-CBNS or by antibiotin-CBNS. Only three cycles of extension reaction are sufficient for detection. No purification of the PCR products or the extension product is required.

  8. Long-wave approximation for hybridization modeling of local surface plasmonic resonance in nanoshells.

    Science.gov (United States)

    Li, Ben Q; Liu, Changhong

    2011-01-15

    A hybridization model for the localized surface plasmon resonance of a nanoshell is developed within the framework of long-wave approximation. Compared with the existing hybridization model derived from the hydrodynamic simulation of free electron gas, this approach is much simpler and gives identical results for a concentric nanoshell. Also, with this approach, the limitations associated with the original hybridization model are succinctly stated. Extension of this approach to hybridization modeling of more complicated structures such as multiplayered nanoshells is straightforward.

  9. Circuit model optimization of a nano split ring resonator dimer antenna operating in infrared spectral range

    Energy Technology Data Exchange (ETDEWEB)

    Gneiding, N., E-mail: Natalia.Gneiding@physik.uni-erlangen.de [Erlangen Graduate School in Advanced Optical Technologies (SAOT), University of Erlangen-Nuremberg, 91052 Erlangen (Germany); Zhuromskyy, O.; Peschel, U. [Institute of Optics, Information and Photonics, University of Erlangen-Nuremberg, 91058 Erlangen (Germany); Shamonina, E. [Department of Engineering Science, University of Oxford, Parks Road, OX1 3PJ Oxford (United Kingdom)

    2014-10-28

    Metamaterials are comprised of metallic structures with a strong response to incident electromagnetic radiation, like, for example, split ring resonators. The interaction of resonator ensembles with electromagnetic waves can be simulated with finite difference or finite elements algorithms, however, above a certain ensemble size simulations become inadmissibly time or memory consuming. Alternatively a circuit description of metamaterials, a well developed modelling tool at radio and microwave frequencies, allows to significantly increase the simulated ensemble size. This approach can be extended to the IR spectral range with an appropriate set of circuit element parameters accounting for physical effects such as electron inertia and finite conductivity. The model is verified by comparing the coupling coefficients with the ones obtained from the full wave numerical simulations, and used to optimize the nano-antenna design with improved radiation characteristics.

  10. Hybrid micro-/nano-structures derived from metal-organic frameworks: preparation and applications in energy storage and conversion.

    Science.gov (United States)

    Cao, Xiehong; Tan, Chaoliang; Sindoro, Melinda; Zhang, Hua

    2017-05-22

    Metal-organic frameworks (MOFs), an important class of inorganic-organic hybrid crystals with intrinsic porous structures, can be used as versatile precursors or sacrificial templates for preparation of numerous functional nanomaterials for various applications. Recent developments of MOF-derived hybrid micro-/nano-structures, constructed by more than two components with varied functionalities, have revealed their extensive capabilities to overcome the weaknesses of the individual counterparts and thus give enhanced performance for energy storage and conversion. In this tutorial review, we summarize the recent advances in MOF-derived hybrid micro-/nano-structures. The synthetic strategies for preparing MOF-derived hybrid micro-/nano-structures are first introduced. Focusing on energy storage and conversion, we then discuss their potential applications in lithium-ion batteries, lithium-sulfur batteries, supercapacitors, lithium-oxygen batteries and fuel cells. Finally, we give our personal insights into the challenges and opportunities for the future research of MOF-derived hybrid micro-/nano-structures.

  11. Directed assembly of hybrid nanostructures using optically resonant nanotweezers

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, David [Cornell Univ., Ithaca, NY (United States)

    2015-09-09

    This represents the final report for this project. Over the course of the project we have made significant progress in photonically driven nano-assembly including: (1) demonstrating the first direct optical tweezer based manipulation of proteins, (2) the ability to apply optical angular torques to microtubuals and other rod-shaped microparticles, (3) direct assembly of hybrid nanostructures comprising of polymeric nanoparticles and carbon nanotubes and, (4) the ability to drive biological reactions (specifically protein aggregation) that are thermodynamically unfavorable by applying localized optical work. These advancements are described in the list of papers provided in section 2.0 of the below. Summary details are provided in prior year annual reports. We have two additional papers which will be submitted shortly based on the work done under this award. An updated publication list will be provided to the program manager when those are accepted. In this report, we report on a new advancement made in the final project year, which uses the nanotweezer technology to perform direct measurements of particle-surface interactions. Briefly, these measurements are important for characterizing the stability and behavior of colloidal and nanoparticle suspensions and current techniques are limited in their ability to measure piconewton scale interaction forces on sub-micrometer particles due to signal detection limits and thermal noise. In this project year we developed a new technique called “Nanophotonic Force Microscopy” which uses the localized region of exponentially decaying, near-field, light to confine small particles close to a surface. From the statistical distribution of the light intensity scattered by the particle the technique maps out the potential well of the trap and directly quantify the repulsive force between the nanoparticle and the surface. The major advantage of the technique is that it can measure forces and energy wells below the thermal noise

  12. A hydrophobic dye-encapsulated nano-hybrid as an efficient fluorescent probe for living cell imaging.

    Science.gov (United States)

    Chang, Shu; Wu, Xumeng; Li, Yongsheng; Niu, Dechao; Ma, Zhi; Zhao, Wenru; Gu, Jinlou; Dong, Wenjie; Ding, Feng; Zhu, Weihong; Shi, Jianlin

    2012-07-01

    Water-soluble hydrophobic-dye@nano-hybrids (DPN@NHs) with extraordinarily enhanced fluorescent performance were fabricated by encapsulating the hydrophobic dye molecules into the core of the hybrid nanospheres based on the self-assembly of amphiphilic block copolymers followed by shell cross-linking using 3-mercaptopropyltrimethoxy-silane. The DPN@NHs are 50 nm in size, are monodispersed in aqueous solution and have a quantum yield enhanced by 30 times.

  13. Radiative Emission Enhancement Using Nano-antennas Made of Hyperbolic Metamaterial Resonators

    CERN Document Server

    Guclu, Caner; Wang, George T; Capolino, Filippo

    2014-01-01

    A hyperbolic metamaterial resonator is analyzed as a nano-antenna for enhancing the radiative emission of quantum emitters in its vicinity. It has been shown that the spontaneous emission rate by an emitter near a hyperbolic metamaterial substrate is enhanced dramatically due to very large density of states. However, enhanced coupling to the free-space, which is central to applications such as solid-state lighting, has not been investigated significantly. Here, we numerically demonstrate approximately 100 times enhancement of the free-space radiative emission at 660 nm wavelength by utilizing a cylindrical HM resonator with a radius of 54 nm and a height of 80 nm on top of an opaque silver-cladded substrate. We also show how the free-space radiation enhancement factor depends on the dipole orientation and the location of the emitter near the subwavelength resonator. Furthermore, we calculate that an array of HM resonators with subwavelength spacings can maintain most of the enhancement effect of a single reso...

  14. Novel Fabrication Techniques for Wafer-Scale Graphene Drum NanoElectroMechanical Resonators

    Science.gov (United States)

    Lee, Sunwoo; Chen, Changyao; Deshpande, Vikram V.; Lee, Gwan Hyoung; Storch, Isaac; Zhang, Congchun; Yu, Young-Jun; Kim, Philip; McEuen, Paul; Hone, James

    2012-02-01

    Graphene NanoElectroMechanical Systems (NEMS) have shown excellent mass sensitivity as well as resonant and oscillatory behaviors that are desirable in mass sensors and active elements in Radio Frequency Integrated Circuit (RFIC) design. Out of many structures proposed for graphene NEMS, it has been recently shown that a drum resonator exhibits higher Q-factor than other structures such as a bar resonator. However, fabricating a large array of drum graphene resonator has been problematic because liquid or gas can be trapped inside the drum. Such issues led to designs with a hole in the center of a drum or with a drainage trench, either at the cost of additional lithography step or lowered Q-factor. Here, we demonstrate two novel fabrication methods that are free of the trapping without any compromise in additional lithography step or Q-factor degradation. In one method, wafer scale graphene is dry-stamped on prefabricated leads, holes and local gates. In the other method, an resist strip with a circular hole at the center holds graphene underneath. I will discuss direct electrical readout and characterization of devices using these two methods. These drum structures may provide a practical way to achieve wafer scale high Q graphene NEMS.

  15. Ultracompact resonator with high quality-factor based on a hybrid grating structure

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug

    2015-01-01

    We numerically investigate the properties of a hybrid grating structure acting as a resonator with ultrahigh quality factor. This reveals that the physical mechanism responsible for the resonance is quite different from the conventional guided mode resonance (GMR). The hybrid grating consists...... of a subwavelength grating layer and an un-patterned high-refractive-index cap layer, being surrounded by low index materials. Since the cap layer may include a gain region, an ultracompact laser can be realized based on the hybrid grating resonator, featuring many advantages over high-contrast-grating resonator...... lasers. The effect of fabrication errors and finite size of the structure is investigated to understand the feasibility of fabricating the proposed resonator....

  16. Optical properties of polysiloxane hybrid thin films containing nano-sized Ag-As-Se chalcogenide clusters

    Science.gov (United States)

    Zha, Congji; Osvath, Peter; Wilson, Gerry; Launikonis, Anton

    2009-02-01

    Chalcogenide glasses are attractive for all-optical signal processing due to their outstanding optical properties, including large optical nonlinearity, a high refractive index and high photosensitivity. In device fabrication, a challenge lies in the difficulty of obtaining thin films with a high stability and good uniformity. In this paper, optical thin films containing nano-sized chalcogenide clusters in polysiloxane matrices are fabricated by a modified plasma deposition process. The optical absorption and luminescence emission properties of the hybrid thin films were characterized by UV-Vis-NIR and fluorescence spectroscopy. Luminescent emission from Ag-As-Se nano-sized clusters was observed for the first time in these nano-hybrid thin films, and the mechanism was discussed.

  17. Detection of alprazolam with a lab on paper economical device integrated with urchin like Ag@ Pd shell nano-hybrids.

    Science.gov (United States)

    Narang, Jagriti; Malhotra, Nitesh; Singhal, Chaitali; Mathur, Ashish; Pn, Anoop Krishna; Pundir, C S

    2017-11-01

    We present results of the studies relating to fabrication of a microfluidic biosensor chip based on urchin like Ag@ Pd shell nano-hybrids that is capable of sensing alprazolam through electrochemical detection. Using this chip we demonstrate, with high reliability and in a time efficient manner, the detection of alprazolam present in buffer solutions at clinically relevant concentrations. Methylene blue (MB) was also doped as redox transition substance for sensing alprazolam. Nano-hybrids modified EμPAD showed wide linear range 1-300ng/ml and low detection limit of 0.025ng/l. Low detection limit can further enhance its suitability for forensic application. Nano-hybrids modified EμPAD was also employed for determination of drug in real samples such as human urine. Reported facile lab paper approach integrated with urchin like Ag@ Pd shell nano-hybrids could be well applied for the determination of serum metabolites. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Quantum electrostatic surface waves in a hybrid plasma waveguide: Effect of nano-sized slab

    Science.gov (United States)

    Shahmansouri, M.; Mahmodi Moghadam, M.

    2017-10-01

    The propagation properties of surface plasmon (SP) waves are studied in a hybrid plasma waveguide (consisting of plasma-gap-dielectric layers) with quantum effects including the Fermi-pressure, the Bohm potential and the exchange-correlation interaction. By using a quantum hydrodynamic model and Maxwell's equations, the dispersion relation of SP waves is derived, which describes the quantum corrected features of the dispersion properties of such surface waves. Previous results in this context are recovered. It is found that the exchange-correlation interactions and the presence of the second dielectric layer drastically modify the behaviors of the surface plasmon waves. The implications of our finding are discussed in some particular cases of interest. Our finding is applicable for understanding the surface wave behaviors in nano-scale systems.

  19. Detecting Both the Mass and Position of an Accreted Particle by a Micro/Nano-Mechanical Resonator Sensor

    Directory of Open Access Journals (Sweden)

    Yin Zhang

    2014-09-01

    Full Text Available In the application of a micro-/nano-mechanical resonator, the position of an accreted particle and the resonant frequencies are measured by two different physical systems. Detecting the particle position sometimes can be extremely difficult or even impossible, especially when the particle is as small as an atom or a molecule. Using the resonant frequencies to determine the mass and position of an accreted particle formulates an inverse problem. The Dirac delta function and Galerkin method are used to model and formulate an eigenvalue problem of a beam with an accreted particle. An approximate method is proposed by ignoring the off-diagonal elements of the eigenvalue matrix. Based on the approximate method, the mass and position of an accreted particle can be decoupled and uniquely determined by measuring at most three resonant frequencies. The approximate method is demonstrated to be very accurate when the particle mass is small, which is the application scenario for much of the mass sensing of micro-/nano-mechanical  resonators. By solving the inverse problem,  the position measurement becomes unnecessary, which is of some help to the mass sensing application  of a micro-/nano-mechanical resonator by reducing two measurement systems to one. How to apply the method to the general scenario of multiple accreted particles is also discussed.

  20. Detecting both the mass and position of an accreted particle by a micro/nano-mechanical resonator sensor.

    Science.gov (United States)

    Zhang, Yin; Liu, Yun

    2014-09-02

    In the application of a micro-/nano-mechanical resonator, the position of an accreted particle and the resonant frequencies are measured by two different physical systems. Detecting the particle position sometimes can be extremely difficult or even impossible, especially when the particle is as small as an atom or a molecule. Using the resonant frequencies to determine the mass and position of an accreted particle formulates an inverse problem. The Dirac delta function and Galerkin method are used to model and formulate an eigenvalue problem of a beam with an accreted particle. An approximate method is proposed by ignoring the off-diagonal elements of the eigenvalue matrix. Based on the approximate method, the mass and position of an accreted particle can be decoupled and uniquely determined by measuring at most three resonant frequencies. The approximate method is demonstrated to be very accurate when the particle mass is small, which is the application scenario for much of the mass sensing of micro-/nano-mechanical  resonators. By solving the inverse problem,  the position measurement becomes unnecessary, which is of some help to the mass sensing application  of a micro-/nano-mechanical resonator by reducing two measurement systems to one. How to apply the method to the general scenario of multiple accreted particles is also discussed.

  1. Removal of nitrate from liquid effluents with bio-nano hybrid materials

    Science.gov (United States)

    Eroglu, Ela; Haniff Wahid, M.; Chen, Xianjue; Smith, Steven M.; Raston, Colin L.

    2013-04-01

    Microalgae are a group of microorganisms that are abundant in the environment and have been commonly used as a tool for sustainable green technologies including bioenergy production1,2, CO2 sequestration2, wastewater treatment3,4, and nutritional supplement5. We have recently developed a hybridization process between common microalgal cells (Chlorella vulgaris) and multi-layer graphene sheets4. Graphene has very strong adhesion energies6 with an ability to attach on the surface of microalgal cells, which results in a functional hybrid material. Initially dynamic thin films formed within a microfluidic platform, as a vortex fluidic device, were used to exfoliate multi-layer graphene from graphite flakes in water. This was followed by hybridizing the multi-layer graphene with microalgal cells. The resulting bio-nano hybrid material was particularly efficient for the removal of nitrate from liquid effluents without being toxic for the microalgal cells. Scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and Raman spectroscopy techniques were used for the characterization of the formed graphene sheets, with the fluorescence microscopy and chlorophyll content analyzed for monitoring the viability and growth pattern of the microalgal cells. E. Eroglu and A. Melis, Biotechnol. Bioeng., 2009, 102(5), 1406-1415. É. C Francisco, D. B. Neves, E. Jacob-Lopes, and T. T. Franco, J. Chem. Technol. Biotechnol., 2010, 85, 395-403. E. Eroglu, V. Agarwal, M. Bradshaw, X. Chen, S.M. Smith, C.L. Raston and K.S. Iyer, Green Chem., 2012, 14(10), 2682 - 2685. M. H. Wahid, E. Eroglu, X. Chen, S.M. Smith, and C.L. Raston, Green Chem., 2012, doi:10.1039/C2GC36892G. P. Spolaore, C. Joannis-Cassan, E. Duran and A. Isambert, J. Biosci. Bioeng., 2006, 101, 87-96. S. P. Koenig, N. G. Boddeti, M. L. Dunn and J. S. Bunch, Nat. Nanotechnol., 2011, 6, 543-546.

  2. Two-chamber configuration of Bio-Nano electron cyclotron resonance ion source for fullerene modification

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, T., E-mail: uchida-t@toyo.jp [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe 350-8585 (Japan); Rácz, R.; Biri, S. [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/C, H-4026 Debrecen (Hungary); Muramatsu, M.; Kitagawa, A. [National Institute of Radiological Sciences (NIRS), Chiba 263-8555 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Faculty of Science and Engineering, Toyo University, Kawagoe 350-8585 (Japan)

    2016-02-15

    We report on the modification of fullerenes with iron and chlorine using two individually controllable plasmas in the Bio-Nano electron cyclotron resonance ion source (ECRIS). One of the plasmas is composed of fullerene and the other one is composed of iron and chlorine. The online ion beam analysis allows one to investigate the rate of the vapor-phase collisional modification process in the ECRIS, while the offline analyses (e.g., liquid chromatography-mass spectrometry) of the materials deposited on the plasma chamber can give information on the surface-type process. Both analytical methods show the presence of modified fullerenes such as fullerene-chlorine, fullerene-iron, and fullerene-chlorine-iron.

  3. Two-chamber configuration of Bio-Nano electron cyclotron resonance ion source for fullerene modification

    Science.gov (United States)

    Uchida, T.; Rácz, R.; Muramatsu, M.; Kato, Y.; Kitagawa, A.; Biri, S.; Yoshida, Y.

    2016-02-01

    We report on the modification of fullerenes with iron and chlorine using two individually controllable plasmas in the Bio-Nano electron cyclotron resonance ion source (ECRIS). One of the plasmas is composed of fullerene and the other one is composed of iron and chlorine. The online ion beam analysis allows one to investigate the rate of the vapor-phase collisional modification process in the ECRIS, while the offline analyses (e.g., liquid chromatography-mass spectrometry) of the materials deposited on the plasma chamber can give information on the surface-type process. Both analytical methods show the presence of modified fullerenes such as fullerene-chlorine, fullerene-iron, and fullerene-chlorine-iron.

  4. Localized surface plasmon resonances in gold nano-patches on a gallium nitride substrate.

    Science.gov (United States)

    D'Antonio, Palma; Inchingolo, Alessio Vincenzo; Perna, Giuseppe; Capozzi, Vito; Stomeo, Tiziana; De Vittorio, Massimo; Magno, Giovanni; Grande, Marco; Petruzzelli, Vincenzo; D'Orazio, Antonella

    2012-11-16

    In this paper we describe the design, fabrication and characterization of gold nano-patches, deposited on gallium nitride substrate, acting as optical nanoantennas able to efficiently localize the electric field at the metal-dielectric interface. We analyse the performance of the proposed device, evaluating the transmission and the electric field localization by means of a three-dimensional finite difference time domain (FDTD) method. We detail the fabrication protocol and show the morphological characterization. We also investigate the near-field optical transmission by means of scanning near-field optical microscope measurements, which reveal the excitation of a localized surface plasmon resonance at a wavelength of 633 nm, as expected by the FDTD calculations. Such results highlight how the final device can pave the way for the realization of a single optical platform where the active material and the metal nanostructures are integrated together on the same chip.

  5. Investigation on driving characteristics of a piezoelectric stick–slip actuator based on resonant/off-resonant hybrid excitation

    Science.gov (United States)

    Cheng, Tinghai; Li, Hengyu; He, Meng; Zhao, Hongwei; Lu, Xiaohui; Gao, Haibo

    2017-03-01

    A resonant/off-resonant hybrid excitation of a piezoelectric stick–slip actuator is proposed in this paper. It is accomplished by a resonant sinusoidal friction regulation wave (RSFR-wave) and an off-resonant saw-tooth wave (ORST-wave). The RSFR-wave is applied to the rapid deformation stage of the ORST-wave. In this stage, the first-order longitudinal vibration mode of the stator can be obtained. By this longitudinal vibration mode, the kinetic friction between the slider and frictional rod is obviously decreased utilizing ultrasonic friction reduction. The backward displacement is remarkably restrained. The high velocity, large mass of load and smooth displacement are achieved. The operation principle of hybrid excitation was discussed in detail, and a prototype was simulated, designed, and fabricated. A series of experiments were carried out and the results indicate that the step efficiency under the saw-tooth excitation and resonant/off-resonant hybrid excitation can realize 36.9% and 91.2%, respectively. The output velocity is increased by 147.23% relative to saw-tooth excitation. The minimum input power and the minimum driving voltage are decreased by 89.56% and 58.33%, respectively. Besides, the maximum mass of load capacity is 2.88 times that of saw-tooth excitation. The driving capacity of the actuator is increased by 466.13%.

  6. Nano

    DEFF Research Database (Denmark)

    Nørgaard, Bent; Engel, Lars Romann

    2007-01-01

    Gennem de sidste par år har et lille ord med et meget stort potentiale gentagende trængt sig på i den offentlige bevidsthed, det er ordet "nano". Nanovidenskab og nanoteknologi er lige nu to af de "hotteste" forskningsområder og betragtes af mange som porten til en helt ny verden af muligheder....... Muligheder, vi endnu ikke kender konsekvenserne af. Center for Kunst og Videnskabs forestilling NANO giver dig chancen for at blive bekendt med verdens mindste byggesten og idégrundlaget for nanoforskningen. Vi har skabt et rum, som på mange måder minder om et laboratorium. Rummet er forsynet med storskærme......, kolber, væsker og nanopartikler. Her vil du f.eks. opleve, hvordan forskere tilfører guld helt nye egenskaber. Forestillingen veksler mellem kemiske arbejdsdemonstrationer, stemningsskabende musik og livlig debat på storskærme mellem eksperter. NANO opfordrer publikum til at tage stilling til forskningen...

  7. Nano-electromechanical switch-CMOS hybrid technology and its applications.

    Science.gov (United States)

    Lee, B H; Hwang, H J; Cho, C H; Lim, S K; Lee, S Y; Hwang, H

    2011-01-01

    Si-based CMOS technology is facing a serious challenge in terms of power consumption and variability. The increasing costs associated with physical scaling have motivated a search for alternative approaches. Hybridization of nano-electromechanical (NEM)-switch and Si-based CMOS devices has shown a theoretical feasibility for power management, but a huge technical gap must be bridged before a nanoscale NEM switch can be realized due to insufficient material development and the limited understanding of its reliability characteristics. These authors propose the use of a multilayer graphene as a nanoscale cantilever material for a nanoscale NEM switchwith dimensions comparable to those of the state-of-the-art Si-based CMOS devices. The optimal thickness for the multilayer graphene (about five layers) is suggested based on an analytical model. Multilayer graphene can provide the highest Young's modulus among the known electrode materials and a yielding strength that allows more than 15% bending. Further research on material screening and device integration is needed, however, to realize the promises of the hybridization of NEM-switch and Si-based CMOS devices.

  8. III-V semiconductor nano-resonators-a new strategy for passive, active, and nonlinear all-dielectric metamaterials

    CERN Document Server

    Liu, Sheng; Reno, John L; Sinclair, Michael B; Brener, Igal

    2016-01-01

    Metamaterials comprising assemblies of dielectric resonators have attracted much attention due to their low intrinsic loss and isotropic optical response. In particular, metasurfaces made from silicon dielectric resonators have shown desirable behaviors such as efficient nonlinear optical conversion, spectral filtering and advanced wave-front engineering. To further explore the potential of dielectric metamaterials, we present all-dielectric metamaterials fabricated from epitaxially grown III-V semiconductors that can exploit the high second-order optical susceptibilities of III-V semiconductors, as well as the ease of monolithically integrating active/gain media. Specifically, we create GaAs nano-resonators using a selective wet oxidation process that forms a low refractive index AlGaO (n~1.6) under layer similar to silicon dielectric resonators formed using silicon-on-insulator wafers. We further use the same fabrication processes to demonstrate multilayer III-V dielectric resonator arrays that provide us w...

  9. Molecular Dynamics Study on the Resonance Properties of a Nano Resonator Based on a Graphene Sheet with Two Types of Vacancy Defects

    Directory of Open Access Journals (Sweden)

    Wenchao Tian

    2017-01-01

    Full Text Available Due to the excellent electronic, optical, thermal, chemical, and mechanical properties of graphene, it has been applied in microdevices and nanodevices. However, there are some structural defects in graphene limiting its application in micro electromechanical systems (MEMS. These structural defects are inevitable during processing, and it is difficult to assess their effect on the micro/nano devices. Therefore, this communication used molecular dynamics to study the resonance properties of a nanoelectromechanical systems (NMES resonator based on a graphene sheet with a single vacancy defect and edge defects. This communication focuses on three factors: vacancy types, external force, and temperature. The resonance frequencies of both types of graphene increased with external stress loading, and the resonance frequency of the graphene showed a clear step-shaped variation. Nonlinear deformation of the sheet occurred between resonant processes. When the external force was less than 15.91 nN, the resonance frequencies of the two types of graphene showed a consistent trend. The maximum frequency was up to 132.90 GHz. When the external force was less than 90 nN, the resonance frequencies of graphene with edge defects were greater and changed more rapidly. Temperature did not have a huge influence on the resonance frequencies of either type of graphene structure. The resonance frequencies of graphene with two different vacancy defects showed a consistent trend.

  10. Fluorescence Resonance Energy Transfer between organic dyes adsorbed onto nano-clay and Langmuir-Blodgett (LB) films

    Science.gov (United States)

    Hussain, Syed Arshad; Chakraborty, S.; Bhattacharjee, D.; Schoonheydt, R. A.

    2010-02-01

    In this communication we investigate two dyes N, N'-dioctadecyl thiacyanine perchlorate (NK) and octadecyl rhodamine B chloride (RhB) in Langmuir and Langmuir-Blodgett (LB) films with or with out a synthetic clay laponite. Observed changes in isotherms of RhB in absence and presence of nano-clay platelets indicate the incorporation of clay platelets onto RhB-clay hybrid films. AFM images confirm the incorporation of clay into hybrid films. FRET is observed in clay dispersion and LB films with and without clay. Efficiency of energy transfer is maximum in LB films with clay.

  11. Rotational characteristics in the resonance state of the HTSC-permanent magnet hybrid magnetic bearing

    Science.gov (United States)

    Morii, Y.; Sukedai, M.; Ohashi, S.

    2011-11-01

    The hybrid magnetic bearing using permanent magnets and the high-Tc bulk superconductor (HTSC) has been developed. Repulsive force of the permanent magnet is introduced to increase the load weight of the magnetic bearing. Effect of the hybrid system has been shown. In this paper, influence of the hybrid system on the dynamic characteristics of the rotor is studied. The rotational characteristics in the mechanical resonance state are studied, and the equivalent magnetic spring coefficient is estimated from the experimental results of the load weight. The resonance frequency is measured by the rotation experiments. The rotor achieves stable levitation even in the resonance state. In the hybrid system, effect of the pinning force becomes smaller than that of the lateral force generated by the repulsive force between the two permanent magnets at the smaller air gap. Thus influence of the lateral vibration and the gradient angle in the resonance state becomes larger at a smaller air gap. The equivalent magnetic spring coefficient becomes also small, and the resonance frequency becomes small in the hybrid bearing system.

  12. Evaluation of rheological behavior of 10W40 lubricant containing hybrid nano-material by measuring dynamic viscosity

    Science.gov (United States)

    Ahmadi Nadooshan, Afshin; Hemmat Esfe, Mohammad; Afrand, Masoud

    2017-08-01

    In the present paper, the dynamic viscosity of 10W40 lubricant containing hybrid nano-materials has been examined. Hybrid nano-materials were composed of 90% of silica (SiO2) with 20-30 nm mean particle size and 10% of multi-walled carbon nanotubes (MWCNTs) with inner diameter of 2-6 nm and outer diameter of 5-20 nm. Nano-lubricant samples were prepared by two-step method with solid volume fractions of 0.05%, 0.1%, 0.25%, 0.5%, 0.75% and 1%. Dynamic viscosity of the samples was measured at temperatures between 5 and 55 °C and at shear rates of 666.5 s-1 up to 11,997 s-1. Experimental results indicated that the nano-lubricant had non-Newtonian behavior at all temperatures, while 10w40 oil was non-Newtonian only at high temperatures. With the use of the curve fitting technique of experimental data, power law and consistency indexes were obtained; furthermore, these coefficients were assessed by shear stress and viscosity diagram.

  13. Direct electro-optical pumping for hybrid CdSe nanocrystal/III-nitride based nano-light-emitting diodes

    Science.gov (United States)

    Mikulics, M.; Arango, Y. C.; Winden, A.; Adam, R.; Hardtdegen, A.; Grützmacher, D.; Plinski, E.; Gregušová, D.; Novák, J.; Kordoš, P.; Moonshiram, A.; Marso, M.; Sofer, Z.; Lüth, H.; Hardtdegen, H.

    2016-02-01

    We propose a device concept for a hybrid nanocrystal/III-nitride based nano-LED. Our approach is based on the direct electro-optical pumping of nanocrystals (secondary excitation) by electrically driven InGaN/GaN nano-LEDs as the primary excitation source. To this end, a universal hybrid optoelectronic platform was developed for a large range of optically active nano- and mesoscopic structures. The advantage of the approach is that the emission of the nanocrystals can be electrically induced without the need of contacting them. The proof of principal was demonstrated for the electro-optical pumping of CdSe nanocrystals. The nano-LEDs with a diameter of 100 nm exhibit a very low current of ˜8 nA at 5 V bias which is several orders of magnitude smaller than for those conventionally used. The leakage currents in the device layout were typically in the range of 8 pA to 20 pA/cm2 at 5 V bias. The photon-photon down conversion efficiency was determined to be 27%. Microphotoluminescence and microelectroluminescence characterization demonstrate the potential for future optoelectronics and highly secure "green" information technology applications.

  14. Rheological Behavior of a Novel Organic-Inorganic Hybrid: Micro/Nano-Tin Fluorophosphate Glass-Polycarbonate.

    Science.gov (United States)

    Yang, Jing; Liu, Huiwen; Yu, Honglin; Zou, Xiaoxuan; Jing, Bo; Dai, Wenli

    2016-03-01

    The rheological behavior of a novel, binary organic-inorganic hybrid consisting of an ultra-low Tg tin fluorophosphate glass (Pglass) and polycarbonate (PC) was investigated using oscillatory rheometry. It was found that the complex viscosity of the hybrid showed Pglass content dependence. Under low Pglass content (10-30%), the complex viscosity of the hybrid was lower than that of pure PC. While the complex viscosity was dramatically increased and higher than that of pure PC with the content of Pglass above 30%. This phenomenon was particularly remarkable at low frequencies. Besides, with the addition of Pglass the hybrid material exhibited shear-thinning behavior and the shear-thinning characteristics became more obvious with the enhancement of the Pglass content, indicating the presence of nonlinear chemical and physical interactions between the hybrid components. Differential scanning calorimetry (DSC) measurements revealed that increasing the content of Pglass caused a decrease of the glass transition temperature (Tg) of the hybrids, suggesting that Pglass was acting as a macromolecular plasticizer for the PC. The microstructure of the Pglass in the hybrid material was characterized by scanning electron microscopy (SEM). The results showed that the Pglass were dispersed as micro- and nano-bead in the continuous phase of PC and the Pglass appeared aggregation partly with the increase of the Pglass content. This contribution was anticipated to be a guideline for the processing of this promising new class of hybrid materials.

  15. Deposition of Layer-by-layer Inorganic-organic Nano-hybrid Ultrathin Films onto SBA-15

    Institute of Scientific and Technical Information of China (English)

    Han Ming DING; Li Ping WANG; Yong Kui SHAN; Ming Yuan HE

    2003-01-01

    Deposition of inorganic-organic nano-hybrid ultrathin films onto mesoporous silicate materials has been proven possible by using layer-by-layer assembly method. In combination with sol-gel method, titania, subsequently dye molecules (or polymer) were successfully fabricated onto the inner wall of SBA-15. Their structures were preliminarily characterized by FTIR and solid-state UV-Vis spectroscopy, thermal analysis, and BET surface area measurements, respectively.

  16. Low-loss and high-symmetry negative refractive index media by hybrid dielectric resonators.

    Science.gov (United States)

    Lai, Yueh-Chun; Chen, Cheng-Kuang; Yang, Yu-Hang; Yen, Ta-Jen

    2012-01-30

    Based on Maxwell's equations and Mie theory, strong sub-wavelength artificial magnetic and electric dipole resonances can be excited within dielectric resonators, and their resonant frequencies can be tailored simply by scaling the size of the dielectric resonators. Therefore, in this work we hybridize commercially available zirconia and alumina structures to harvest their individual artificial magnetic and electric response simultaneously, presenting a negative refractive index medium (NRIM). Comparing with the conventional NRIM constructed by metallic structures, the demonstrated all-dielectric NRIM possesses low-loss and high-symmetry advantages, thus benefiting practical applications in communication components, perfect lenses, invisible cloaking and other novel electromagnetic devices.

  17. Highly efficient catalytic reductive degradation of various organic dyes by Au/CeO₂-TiO₂ nano-hybrid

    Indian Academy of Sciences (India)

    PRANJAL SAIKIA; ABU T MIAH; PARTHA P DAS

    2017-01-01

    Highly improved catalytic reductive degradation of different organic dyes, in the presence of excess NaBH₄ over Au/CeO₂-TiO₂ nano-hybrid as the catalyst is reported in this study. CeO₂-TiO₂ nanocomposite was prepared by a facile co-precipitation method using ultra-high dilute aqueous solutions. Small amount of Au (only 1 wt%) was loaded onto the nanocomposite material by deposition-precipitation with urea (DPU) method to fabricate the ternary Au/CeO₂-TiO₂ nano-hybrid. The catalysts were characterized by the representative techniques like XRD, BET surface area, ICP-AES, UV-Vis diffuse reflectance spectroscopy, TEM and XPS. The Au/CeO₂-TiO₂ nano-hybrid along with NaBH₄ exhibited remarkable catalytic activities towards all the probed dyes, namely Methylene Blue, Methyl Orange, Congo Red, Rhodamine B and Malachite Green, with a degradation efficiency of ~100% in a short reaction time. The degradation reaction followed pseudo-first-order kinetics with respect to the concentration of the dye. Different parameters that affect the rate of the reaction are discussed. A plausible mechanism for methylene blue degradation has also been proposed.

  18. Effects of layer eccentricity on the super-resonant states of active cylindrical core-shell nano-particles

    Directory of Open Access Journals (Sweden)

    Thorsen Rasmus Ø.

    2015-01-01

    Full Text Available This work reports on the effects of layer eccentricity on the resonant properties of active cylindrical core-shell nano-particles excited by a near-by exterior magnetic line source. The core-shell particles consist of a silver core layered with a silica shell. For a fixed over-all radius of the nano-particle equal to 30 nm, we investigate designs with relatively small (radius equal to 6 nm and large (radius equal to 24 nm silver cores and we quantify their performance characteristics in terms of the near- and far-field properties. Our results show that the super-resonances, known to exist in the concentric version of these nano-particles, are significantly influenced by introducing eccentricity (through displacements of the silver core relative to the silica shell. In particular, their amplitude responses are found to diminish significantly for silver core displacements ≥ 3 nm for the small core case, and even for displacements ≥ 1 nm for the large core case. The present results are useful from the experimental point of view since slight displacements of the centers of the core and shell parts of the investigated nano-particles are likely to occur in standard fabrication processes.

  19. Hybrid Resonators and Highly Tunable Terahertz Metamaterials Enabled by Vanadium Dioxide (VO2).

    Science.gov (United States)

    Wang, Shengxiang; Kang, Lei; Werner, Douglas H

    2017-06-28

    Hybrid metamaterials that exhibit reconfigurable responses under external stimulus, such as electric fields and light radiation, have only recently been demonstrated by combining active media with patterned metallic structures. Nevertheless, hybrid terahertz (THz) metamaterials whose spectral performance can be dynamically tuned over a large scale remain rare. Compared with most active media (for instance, silicon) that provide limited activity, vanadium dioxide (VO2), which exhibits an insulator-to-metal transition, has been recently explored to facilitate dynamically tunable metamaterials. More importantly, the phase transition yields a three orders of magnitude increase in THz electrical conductivity, which suggests the potential for creating VO2 based hybrid resonators that operate at THz frequencies. Here, we show that an integration of VO2 structures and conventional metallic resonating components can enable a class of highly tunable THz metamaterials. Considering the widely studied phase-transition dynamics in VO2, the proposed hybrid metamaterials are capable of offering ultrafast modulation of THz radiation.

  20. Efficient suppression of radiation damping in individual plasmonic resonators: towards high-Q nano-volume sensing

    DEFF Research Database (Denmark)

    Della Valle, G.; Bozhevolnyi, S. I.

    2012-01-01

    Recent results on radiation damping suppression in individual plasmonic resonators using conformal bending of the structure, which suppresses the electric-dipole response in favor of magnetic dipole one, are overviewed. It is demonstrated that bending of linear plasmonic nano-antennas increases...... significantly their Q factors above the electrostatic limit while preserving the nature of resonance along with its exceptional features, such as linear size-dependent tunability and robust field enhancement. The approach, which makes use of strong lateral confinement exhibited by the slow plasmonic modes (slow...

  1. Hybrid localized waves supported by resonant anisotropic metasurfaces

    DEFF Research Database (Denmark)

    Bogdanov, A. A.; Yermakov, O. Y.; Ovcharenko, A. I.

    2016-01-01

    We study both theoretically and experimentally a new class of surface electromagnetic waves supported by resonant anisotropic metasurface. At certain frequency this type of metasurface demonstrates the topological transition from elliptical to hyperbolic regime.......We study both theoretically and experimentally a new class of surface electromagnetic waves supported by resonant anisotropic metasurface. At certain frequency this type of metasurface demonstrates the topological transition from elliptical to hyperbolic regime....

  2. Surface plasmon resonance spectroscopy of single bowtie nano-antennas using a differential reflectivity method.

    Science.gov (United States)

    Kaniber, M; Schraml, K; Regler, A; Bartl, J; Glashagen, G; Flassig, F; Wierzbowski, J; Finley, J J

    2016-03-23

    We report on the structural and optical properties of individual bowtie nanoantennas both on glass and semiconducting GaAs substrates. The antennas on glass (GaAs) are shown to be of excellent quality and high uniformity reflected by narrow size distributions with standard deviations for the triangle and gap size of = 4.5 nm = 2.6 nm and = 5.4 nm = 3.8 nm, respectively. The corresponding optical properties of individual nanoantennas studied by differential reflection spectroscopy show a strong reduction of the localised surface plasmon polariton resonance linewidth from 0.21 eV to 0.07 eV upon reducing the antenna size from 150 nm to 100 nm. This is attributed to the absence of inhomogeneous broadening as compared to optical measurements on nanoantenna ensembles. The inter-particle coupling of an individual bowtie nanoantenna, which gives rise to strongly localised and enhanced electromagnetic hotspots, is demonstrated using polarization-resolved spectroscopy, yielding a large degree of linear polarization of ρmax ~ 80%. The combination of highly reproducible nanofabrication and fast, non-destructive and non-contaminating optical spectroscopy paves the route towards future semiconductor-based nano-plasmonic circuits, consisting of multiple photonic and plasmonic entities.

  3. Surface Plasmon Resonance Characteristics of Optical Fiber Incorporated with Au Nano-Particles in Cladding Region.

    Science.gov (United States)

    Ju, Seongmin; Jeong, Seongmook; Kim, Youngwoong; Lee, Sang-Hyun; Han, Won-Taek

    2016-06-01

    A novel surface plasmon resonance (SPR) sensor based on specialty optical fiber having its cladding doped with Au nano-particles (NPs) was developed by modified chemical vapor deposition process. To optimize the SPR absorption and sensitivity of the fiber SPR sensor, effect of the fiber length (20 cm-90 cm) on sensing capability of refractive index (n = 1.418-1.448) was investigated. Absorption peaks appearing at 392 and 790 nm were due to SPR from Au NPs in the cladding region of the optical fiber. The SPR was found to occur at particular wavelengths around 390 nm for the corresponding refractive indices regardless of the length of the fiber, increased with the increase of the index. The measured SPR sensitivities (wavelength/RIU) of the fiber were estimated to be 407 nm/RIU, 217 nm/RIU, and 54 nm/RIU with the fiber lengths of 20 cm, 45 cm, and 90 cm, respectively. The SPR absorption intensity and FWHM decreased with the increase of the fiber length because the propagation loss of the signal through the fiber cladding region increased.

  4. Coherent resonance of quantum plasmons in the graphene-gold cluster hybrid system.

    Science.gov (United States)

    Zhang, Kaibiao; Zhang, Hong; Li, Chikang

    2015-05-14

    Noble metal nanoparticles can modify the optical properties of graphene. Here we present a detailed theoretical analysis of the coherent resonance of quantum plasmons in the graphene-gold cluster hybrid system by using time dependent density functional theory (TDDFT). This plasmon coherent effect is mainly attributed to the electromagnetic field coupling between the graphene and the gold cluster. As a result, the optical response of the hybrid system exhibits a remarkably strong, selectable tuning and polarization dependent plasmon resonance enhanced in wide frequency regions. This investigation provides an improved understanding of the plasmon enhancement effect in a graphene-based photoelectric device.

  5. Linear and nonlinear optics of hybrid plasmon-exciton nanomaterials in the presence of overlapping resonances

    CERN Document Server

    Sukharev, Maxim; Pachter, Ruth

    2015-01-01

    We consider a hybrid plasmon-exciton system comprised of a resonant molecular subsystem and three Au wires supporting a dipole mode which can be coupled to a dark mode in controllable fashion by variation of a symmetry parameter. The physics of such a system under strong coupling conditions is examined in detail. It is shown that if two wires supporting the dark mode are covered with molecular layers the system exhibits four resonant modes for a strong coupling regime due to asymmetry and lifted degeneracy of the molecular state in this case, while upon having molecular aggregates covering the top wire with dipolar mode, three resonant modes appear. Pump-probe simulations are performed to scrutinize the quantum dynamics and find possible ways to control plasmon-exciton materials. It is demonstrated that one can design hybrid nanomaterials with highly pronounced Fano-type resonances when excited by femtosecond lasers.

  6. The ion-ion hybrid Alfvén resonator in a fusion environment

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, W. A. [Univ. of California, Los Angeles, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Morales, G. J. [Univ. of California, Los Angeles, CA (United States)

    2014-06-01

    An investigation is made of a shear Alfvén wave resonator for burning plasma conditions expected in the ITER device. For small perpendicular scale-lengths the shear mode, which propagates predominantly along the magnetic field direction, experiences a parallel reflection where the wave frequency matches the local ion-ion hybrid frequency. In a tokamak device operating with a deuterium–tritium fuel, this effect can form a natural resonator because of the variation in local field strength along a field line. The relevant kinetic dispersion relation is examined to determine the relative importance of Landau and cyclotron damping over the possible resonator parameter space. A WKB model based on the kinetic dispersion relation is used to determine the eigenfrequencies and the quality factors of modes trapped in the resonator. The lowest frequency found has a value slightly larger than the ion-ion hybrid frequency at the outboard side of a given flux surface. The possibility that the resonator modes can be driven unstable by energetic alpha particles is considered. It is found that within a bandwidth of roughly 600 kHz above the ion-ion hybrid frequency on the outboard side of the flux surface, the shear modes can experience significant spatial amplification. An assessment is made of the form of an approximate global eigenmode that possesses the features of a resonator. It is identified that magnetic field shear combined with large ion temperature can cause coupling to an ion-Bernstein wave, which can limit the instability.

  7. TiO2 micro-nano-hybrid surface to alleviate biological aging of UV-photofunctionalized titanium

    Directory of Open Access Journals (Sweden)

    Iwasa F

    2011-06-01

    Full Text Available Fuminori Iwasa1, Naoki Tsukimura1, Yoshihiko Sugita1, Rajita Kodali Kanuru1, Katsutoshi Kubo1, Hafiz Hasnain1, Wael Att1,2, Takahiro Ogawa11Laboratory of Bone and Implant Sciences (LBIS, The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA; 2Department of Prosthodontics, Dental School, Albert-Ludwigs University, Freiburg, GermanyAbstract: Bioactivity and osteoconductivity of titanium degrade over time after surface processing. This time-dependent degradation is substantial and defined as the biological aging of titanium. UV treatment has shown to reactivate the aged surfaces, a process known as photofunctionalization. This study determined whether there is a difference in the behavior of biological aging for titanium with micro-nano-hybrid topography and titanium with microtopography alone, following functionalization. Titanium disks were acid etched to create micropits on the surface. Micro-nano-hybrid surfaces were created by depositioning 300-nm diameter TiO2 nodules onto the micropits using a previously established self-assembly protocol. These disks were stored for 8 weeks in the dark to allow sufficient aging, then treated with UV light for 48 hours. Rat bone marrow–derived osteoblasts were cultured on fresh disks (immediately after UV treatment, 3-day-old disks (disks stored for 3 days after UV treatment, and 7-day-old disks. The rates of cell attachment, spread, proliferation, and levels of alkaline phosphatase activity, and calcium deposition were reduced by 30%–50% on micropit surfaces, depending on the age of the titanium. In contrast, 7-day-old hybrid surfaces maintained equivalent levels of bioactivity compared with the fresh surfaces. Both micropit and micro-nano-hybrid surfaces were superhydrophilic immediately after UV treatment. However, after 7 days, the micro-nano-hybrid surfaces became hydrorepellent

  8. Hybrid Nano composite Membranes for PEMFC Applications; Conception et elaboration de membranes hybrides nanocomposites pour l'application pile a combustible PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Niepceron, F.

    2008-03-15

    This work aims at validating a new concept of hybrid materials for the realization of proton exchange membranes, an essential constituent of PEM fuel cells. The originality of this nano-composite hybrid concept corresponds to a separation of the membrane's properties. We investigated the preparation of composite materials based on an inert, relatively low cost, polymer matrix (PVDF-HFP) providing the mechanical stability embedding inorganic fillers providing the necessary properties o f proton-conduction and water retention. The first step of this work consisted in the modification of fumed silica to obtain a proton-conducting filler. An ionic exchange capacity (CEI) equal to 3 meq/g was obtained by the original grafting of sodium poly(styrene-sulfonate) chains from the surface of particles. Nano-composite hybrid membranes PVDF-HFP/functionalized silica were accomplished by a film casting process. The coupling of the morphological and physicochemical analyses validated the percolation of the inorganic phase for 30 wt.% of particles. Beyond 40 % of loading, measured protonic conductivity is higher than the reference membrane Nafion 112. Finally, these membranes presented high performances, above 0.8 W/cm{sup 2}, in single-cell fuel cell tests. A compromise is necessary according to the rate of loading between performances in fuel cell and mechanical properties of the membrane. 50 % appeared as best choice with, until 90 C, a remarkable thermal stability of the performances. (author)

  9. Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing.

    Science.gov (United States)

    Huan, Z; Fratila-Apachitei, L E; Apachitei, I; Duszczyk, J

    2014-02-07

    The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

  10. Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing

    Science.gov (United States)

    Huan, Z.; Fratila-Apachitei, L. E.; Apachitei, I.; Duszczyk, J.

    2014-02-01

    The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

  11. Surface plasmon coupled emission studies on engineered thin film hybrids of nano α−Al{sub 2}O{sub 3} on silver

    Energy Technology Data Exchange (ETDEWEB)

    Mulpur, Pradyumna; Chunduri, Avinash; Rattan, Tanu Mimani; Kamisetti, Venkataramaniah [Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh, India 515134 (India); Lingam, Kiran; Rao, Apparao M. [Department of Physics and Astronomy, 202C Kinard Laboratory, Clemson University, Clemson, SC 29634 (United States)

    2014-01-28

    We report the first time engineering and fabrication of a novel thin film hybrid of nano α-alumina doped in a polyvinyl alcohol (PVA) matrix along with rhodamine b (Rh.B) on a silver thin film. Silver films of 50 nm thickness on glass slides were fabricated by thermal evaporation. Nano α-alumina was synthesized through the combustion route and characterized by XRD. The α-alumina was dispersed in the PVA-Rh.B matrix by tip sonication. The resultant solution was spin coated on the Ag thin film at 3000 rpm to generate an overcoat of ∼30 nm. We have designed and constructed an opto-mechanical setup for performing the SPCE studies. Excitation with a 532 nm continuous laser, led to the coupling of the energy of Rh.B emission to the surface plasmon modes of silver. The emission @ 580 nm was recorded using an Ocean Optics(copyright, serif) fiber optic spectrometer. Calculation of the ratio of signal intensity between the directional SPCE and isotropic fluorescence gives us the factor of signal enhancements which SPCE offers. We report an '8 fold' signal enhancement attributed to SPCE arising from the metal oxide doped thin film hybrid. We observed only a '5 fold' signal enhancement in the case of a thin film hybrid without α-alumina. The emission was also 92% P-polarized which is in coherence with the theory of SPCE. The greater degree of signal enhancement observed in the α-alumina doped thin film substrate can be attributed to the surface roughness which alumina offers to silver, which along with the porous nature of alumina enables a greater degree of adsorption of Rh.B which results in a higher emission intensity. Computational modeling was also performed, based on surface plasmon resonance (SPR) calculations to provide theoretical background to observed experimental data. The α-alumina thin film hybrid can be extended as an economical sensing platform towards the high sensitive detection of analytes.

  12. Tube-graft-Sheet Nano-Objects Created by A Stepwise Self-Assembly of Polymer-Polyoxometalate Hybrids.

    Science.gov (United States)

    Tang, Jing; Li, Xue-Ying; Wu, Han; Ren, Li-Jun; Zhang, Yu-Qi; Yao, Hai-Xia; Hu, Min-Biao; Wang, Wei

    2016-01-19

    In this work, we report the preparation of complex nano-objects by means of a stepwise self-assembly of two polymer-polyoxometalate hybrids (PPHs) in solution. The PPHs are designed and synthesized by tethering two linear poly(ε-caprolactone)s (PCL) of different molecular weights (MW) on a complex of a Wells-Dawson-type polyoxometalate (POM) cluster and its countraions. The higher MW PCL-POM self-assembled into nanosheets, while the lower MW PCL-POM assembled into nanotubes just by altering the ratio of water in the DMF-water mixed solvent system. The two nano-objects have a similar membrane structure in which a PCL layer is sandwiched by the two POM-based complex layers. The PCL layer in the nanosheets is semicrystalline, while the PCL layer in the nanotubes is amorphous. We further exploited this MW-dependence to self-assemble the nanotubes on the nanosheet edges to create complex tube-graft-sheet nano-objects. We found that the nanotubes nucleate on the four {110} faces of the PCL crystal and then further grow along the crystallographic b-axis of the PCL crystal. Our findings offer hope for the further development of nano-objects with increasing complexity.

  13. Observation of the induced pressure in a hybrid micro/nano-channel

    Institute of Scientific and Technical Information of China (English)

    KONG Gao-pan; ZHENG Xu; SILBER-LI Zhan-hua; XU Zheng

    2013-01-01

    This paper studies the flow characteristics in micro/nano-channels subjected to an applied electric field.The nano-channel flow was observed by means of the fluorescence Calcein.A Fluorescence Concentration Gradient Interface (FCGI) was observed across the nano-channel array.The front of the FCGI was shown to have an analogous parabolic shape.The propagation of this interface reflects indirectly the induced pressure at the micro/nano-channel junction,where the enrichment-depletion processes are known to take place.This induced pressure was predicted by numerical simulations,and this paper gives the first experimental evidence.

  14. A review on graphite and hybrid nano-materials as lubricant additives

    Science.gov (United States)

    Anand, Gautam; Saxena, Prateek

    2016-09-01

    The paper presents a review on use of nano-particles as lubricant additives. Nanoparticles have a strong potential to improve the lubrication property of grease when they are used as additives. Nano-grease has several advantages such as improved frictional behaviour, high load bearing capacity and reduced wear, as compared to base oil grease. Current advancements, limitations and challenges in use of nano-grease as a lubricant are discussed. Although, nanogrease has shown outstanding results, more research is required in this field for the commercialization of technology related to nano-grease.

  15. EFFECT OF SURFACE SEALING ON STAIN RESISTANCE OF A NANO-HYBRID RESIN COMPOSITE*

    Directory of Open Access Journals (Sweden)

    Günçe SAYGI

    2015-04-01

    Full Text Available Purpose: This study investigated the influence of sealant application on stain resistance of a nanohybrid resin composite compared to the efficacy of a bonding agent used as a surface sealant on prolonging color stability of the resin composite. Materials and Methods: 28 disc-shaped materials were prepared from a nano-hybrid resin composite Filtek Z550 and assigned to four groups: G1K: nonsealed; G2:Adper Single Bond; G3: Fortify ; G4: Biscover LV. After 24 h storage in distilled water at 37˚C, all specimens were subjected to thermocycling and immersed into coffee solution. Color measurements were performed using spectrophotometer (VITA Easyshade; Vident according to CIEL*a*b* system. Results: Color change values were significantly different among the groups in each evaluation period except for after thermocycling (p<0.05. For 7 days evaluation period, the difference between G3 and G4 group was statistically significant while G4 exhibited statistically significant differences (p<0.05 and p<0.0001 respectively compared to control (G1 in 14 day whereas no significant difference was found between GI and GII in 28-day evaluation period. However, ΔE values of sealed specimens (GIII, GIV differed significantly from non-sealed (GI specimens after 28 days of immersion in coffee solution (p<0.05 and p<0.0001 respectively. Conclusion: It may be concluded that using a bonding agent as a surface sealant does not increase stain resistance of resin composites of the sealants evaluated. Biscover LV showed the highest efficacy to prolong color stability of the resin composite.

  16. Nano rods for coloured glasses obtained by hybrid sol-gel coating.

    Science.gov (United States)

    Veron, Olivier; Blondeau, Jean-Philippe; Moineau, Johanne; Aubert, Pierre-Henri; Vignolle, Caroline Andreazza; Banet, Philippe; Allam, Lévi

    2011-09-01

    Many new materials are now allowing new properties thanks to nanotechnology because this domain of physics gives possibilities to optimize targeted properties even if these materials react in very various influential parameters. Architectural, automotive, bone pathologies, environment, display applications are some concerned domains. The sol-gel process is a method allowing the realisation of coats at ambiant temperature, thus it is possible to realize Liquid Crystal Display (LCD), water-repellent coatings on privacy glass, antireflective coatings, hydrophobic or hydrophilic surfaces, bone tissue regeneration. In this study, the purpose is to show the thermal influence on a covered glass with a complex hybrid sol-gel solution. This coated glass is going to change color from red to orange under the heat influence. This color change effect comes from the evolution of various compounds organizations then/or from their loss during the degassing sequence. We show in spite of the complexity of the process that the responsible is mainly the organic dye. Thus the structure of the heated glass at 250 degrees C looks radically different than the heated one at 350 degrees C. SEM measurement allows to identify the surface compositions and to determine the elementary composition along the sample's cross section. TGA is used to justify a mass loss when samples are annealed. UV/Visible measurement is realized by two methods: in-line transmission to evaluate luminous flux and thus give colorimetric dot in the normalized CIE diagram and diffuse transmission to observe the size influence of the pigments. Infrared Reflectivity allows to evaluate the influence of species on the structure and to better target the nature of the lost compounds during annealing. TEM measurement proves that the obtained iron particles are nano rods for both samples.

  17. A novel circuit topology of modified switched boost hybrid resonant inverter fitted induction heating equipment

    Directory of Open Access Journals (Sweden)

    Bhattacharya Ananyo

    2016-12-01

    Full Text Available A novel circuit topology of modified switched boost high frequency hybrid resonant inverter fitted induction heating equipment is presented in this paper for efficient induction heating. Recently, induction heating technique is becoming very popular for both domestic and industrial purposes because of its high energy efficiency and controllability. Generally in induction heating, a high frequency alternating magnetic field is required to induce the eddy currents in the work piece. High frequency resonant inverters are incorporated in induction heating equipment which produce a high frequency alternating magnetic field surrounding the coil. Previously this high frequency alternating magnetic field was produced by voltage source inverters. But VSIs have several demerits. So, in this paper, a new scheme of modified switched boost high frequency hybrid resonant inverter fitted induction heating equipment has been depicted which enhances the energy efficiency and controllability and the same is validated by PSIM.

  18. Collective scattering in hybrid nanostructures with many atomic oscillators coupled to an electromagnetic resonance

    Science.gov (United States)

    Fauché, Pierre; Kosionis, Spyridon G.; Lalanne, Philippe

    2017-05-01

    There is considerable interest in collective effects in hybrid systems formed by molecular or atomic ensembles strongly coupled by an electromagnetic resonance. For analyzing such collective effects, we develop an efficient and general theoretical formalism based on the natural modes of the resonator. The main strength of our approach is its generality and the high level of analyticity enabled by modal analysis, which allows one to model complex hybrid systems without any restriction on the resonator shapes or material properties, and to perform statistical computations to predict general properties that are robust to spatial and polarization disorders. Most notably, we establish that super-radiant modes remain even after ensemble averaging and act as an "invisibility cloak" with a spectral bandwidth that scales with the number of oscillators and the spatially averaged Purcell factor.

  19. Graphene coated fiber optic surface plasmon resonance biosensor for the DNA hybridization detection: Simulation analysis

    Science.gov (United States)

    Shushama, Kamrun Nahar; Rana, Md. Masud; Inum, Reefat; Hossain, Md. Biplob

    2017-01-01

    In this paper, a graphene coated optical fiber surface plasmon resonance (SPR) biosensor is presented for the detection of DNA Hybridization. For the proposed sensor, a four layer model (fiber core /metal /sensing layer /sample) where a sheet of graphene (biomolecular recognition elements (BRE)) acting as a sensing layer is coated around the gold film because graphene enhances the sensitivity of fiber optic SPR biosensor. Numerical analysis shows the variation of resonance wavelength and spectrum of transmitted power for mismatched DNA strands and for complementary DNA strands. For mismatched DNA strands variation is negligible whereas for complementary DNA strands is considerably countable. Proposed sensor successfully distinguishes hybridization and single nucleotide polymorphisms (SNP) by observing the variation level of resonance wavelength and spectrum of transmitted power.

  20. Quantum Dot / Optical Protein Bio-Nano Hybrid System for Biosensing Applications

    Science.gov (United States)

    2008-12-01

    modulation mechanism for bio -nano electronic application. We have utilized ionic-self assembled monolayer (I-SAM) techniques to create a novel alternating...the QD photonic output based on proximity to bR in the ISAM films could provide a direct method to modulate the electrical output for bio -nano sensing applications.

  1. Multiplex PCR, amplicon size and hybridization efficiency on the NanoChip electronic microarray

    DEFF Research Database (Denmark)

    Børsting, Claus; Sanchez, Juan J; Morling, Niels

    2004-01-01

    We tested the SNP typing protocol developed for the NanoChip electronic microarray by analyzing the four Y chromosome loci SRY1532, SRY8299, TAT, and 92R7. Amplicons of different lengths containing the same locus were purified and addressed to the NanoChip array and fluorescently labelled reporter...

  2. Analytical study of the frequency shifts of micro and nano clamped–clamped beam resonators due to an added mass

    KAUST Repository

    Bouchaala, Adam M.

    2016-03-18

    We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped–clamped micro and nano (Carbon nanotube) beams due to an added mass. Based on the Euler–Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes. © 2016 Springer Science+Business Media Dordrecht

  3. Multifunctional all-dielectric nano-optical systems using collective multipole Mie resonances: Towards on-chip integrated nanophotonics

    CERN Document Server

    Chattaraj, Swarnabha

    2016-01-01

    We present an analysis of the optical response of a class of on-chip integrated nano-photonic systems comprising all-dielectric building block based multifunctional light manipulating units (LMU) integrated with quantum dot (QD) light sources. The multiple functions (such as focusing excitation light, QD emission rate enhancement, photon guidance, and lossless propagation) are simultaneously realized using the collective Mie resonances of dipole and higher order multipole modes of the dielectric building blocks (DBBs) constituting a single structural unit, the LMU. Using analytical formulation based on Mie theory we demonstrate enhancement of the excitation light simultaneously with the guiding and propagation of the emitted light from a QD emitter integrated with the DBB based LMU. The QD-DBB integrated structures can serve as the basic element for building nano-optical active circuits for optical information processing in both classical and quantum realms.

  4. Organic-inorganic hybrid polyionic liquid based polyoxometalate as nano porous material for selective oxidation of sulfides

    Science.gov (United States)

    Rafiee, Ezzat; Shahebrahimi, Shabnam

    2017-07-01

    Organic-inorganic hybrid nano porous materials based on poly(ionic liquid)-polyoxometalate (PIL-POM) were reported. These hybrid materials were synthesized by the reaction of 4-vinyl pyridine with 1,3-propanesultone, followed by the polymerization and also sulfonate-functionalized cross-linked poly(4-vinylpyridine) and combining these polymers with H5PMo10V2O40 (PMo10V2). Activity of prepared PIL-PMo10V2 hybrids were investigated as catalysts for oxidation of sulfides with H2O2 as oxidant. For understanding catalytic activities of the PIL-PMo10V2 hybrids in oxidation of sulfides, effect of catalyst composition, substrate, and reaction conditions were studied. The results show that the PIL-PMo10V2 hybrids are active as selective heterogeneous catalysts for oxidation of sulfides and can be recovered and reused. The catalyst was characterized by FT-IR, TGA-DSC, XRD, SEM/EDX, BET, CV and zeta potential measurement. Also, average molecular weight of prepared catalysts were measured.

  5. The Effects of Coupling Agents on the Properties of Polyimide/Nano-Al2O3 Three-Layer Hybrid Films

    Directory of Open Access Journals (Sweden)

    Lizhu Liu

    2010-01-01

    Full Text Available PI/nano-Al2O3 hybrid films were prepared by ultrasonic-mechanical method. Before addition, nano-Al2O3 particles were firstly modified with different coupling agents. The micromorphology, thermal stability, mechanical properties, and electric breakdown strength of hybrid films were characterized and investigated. Results indicated that nano-Al2O3 particles were homogeneously dispersed in the PI matrix by the addition of coupling agents. The thermal stability and mechanical properties of PI/nano-Al2O3 composite films with KH550 were the best. The tensile strength and elongation at break of PI composite film were 119.1 MPa and 19.1%, which were 14.2% and 78.5% higher than unmodified PI composite film, respectively.

  6. Hybridized exciton-polariton resonances in core-shell nanoparticles

    CERN Document Server

    Gentile, Martin J

    2016-01-01

    The goal of nanophotonics is to control and manipulate light at length scales below the diffraction limit. Typically nanostructured metals are used for this purpose, light being confined by exploiting the surface plasmon-polaritons such structures support. Recently excitonic (molecular) materials have been identified as an alternative candidate material for nanophotonics. Here we use theoretical modelling to explore how hybridisation of surface exciton-polaritons can be achieved through appropriate nanostructuring. We focus on the extent to which the frequency of the hybridised modes can be shifted with respect to the underlying material resonances.

  7. Resonant parametric excitations driven by lower-hybrid fields

    Energy Technology Data Exchange (ETDEWEB)

    Villalon, E.

    1980-11-01

    Three-wave parametric excitation in inhomogeneous plasmas is examined in a two-dimensional geometry relevant to supplementary rf heating of tokamaks. The stabilization of resonant parametric excitation due to a linear mismatch in wavenumbers and to the Landau-damping rates of the decay waves is analyzed, assuming that the magnitude of the pump field is constant in time and in the spatial region where the resonant interaction takes place. Both types of temporally growing modes and spatially amplified instabilities are studied, using a WKB analysis. It is shown that either by increasing the strength of the mismatch K' or the width of the pump L, the growth rate of the fastest growing normal mode will decrease. When the excited waves are slightly damped, it is shown that there exists a finite value of the product K'L, such that, above it, no temporal normal modes are excited. The amount of spatial amplification is also reduced by the mismatch in wavenumbers and by the damping rates of the excited waves. Because of the finite spatial extent of the pump electric field, the amplification length is found to be smaller than or equal to L, depending on the strength of the mismatch and damping rates.

  8. Resonant parametric excitations driven by lower-hybrid fields

    Science.gov (United States)

    Villalon, E.

    1980-11-01

    Three-wave parametric excitation in inhomogeneous plasmas is examined in a two-dimensional geometry relevant to supplementary rf heating of tokamaks. The stabilization of resonant parametric excitation due to a linear mismatch in wavenumbers and to the Landau-damping rates of the decay waves is analyzed, assuming that the magnitude of the pump field is constant in time and in the spatial region where the resonant interaction takes place. Both types of temporally growing modes and spatially amplified instabilities are studied, using a WKB analysis. It is shown that by increasing the strength of the mismatch K prime or the width of the pump L, the growth rate of the fastest growing normal mode will decrease. The amount of spatial amplification is also reduced by the mismatch in wavenumbers and by the damping rates of the excited waves. Because of the finite spatial extent of the pump electric field, the amplification length is smaller than or equal to L, depending on the strength of the mismatch and damping rates.

  9. Resonant UPS topologies for the emerging hybrid fiber coaxial networks

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, H.

    1999-07-01

    Uninterruptible power systems (UPS)are essential to the operation of critical equipment such as life-support systems, computers and telecommunications systems. Ideally, UPS topologies, especially for the emerging hybrid fiber-coaxial networks, must be characterized by relatively small size, high input power factor and trapezoidal waveforms. None of the existing topologies meet all these requirements. Consequently, the objective of this study is to design and analyse UPS topologies that meet these requirements. To meet this objective novel UPS topologies and control techniques are proposed to allow operation of high switching frequencies without penalizing converter efficiency. A self-sustained oscillation control method is proposed to ensure soft switching under all operating conditions.

  10. Grid-connected Photovoltaic Micro-inverter with New Hybrid Control LLC Resonant Converter

    DEFF Research Database (Denmark)

    Xingkui, Mao; Qisheng, Huang; Qingbo, Ke;

    2016-01-01

    A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse-frequency modulat......A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse......-frequency modulation (PFM) and phase-shift pulse-width modulation (PS-PWM) is employed on a full-bridge LLC dc-dc converter, in order to achieve high efficiency when PV output voltage varies in a wide range. Moreover, a maximum power point tracking (MPPT) method based on power perturbation is implemented in the dc......-ac inverter. Therefore, the complexity of regulating LLC converter can be reduced effectively, and efficiency optimal design can be carried out through the proposed designing procedure for the resonant tank of LLC converter. Finally, a prototype of the proposed PV micro-inverter (PVMI) is developed with rated...

  11. Two-year clinical comparison of a flowable-type nano-hybrid composite and a paste-type composite in posterior restoration.

    Science.gov (United States)

    Hirata-Tsuchiya, Shizu; Yoshii, Shinji; Ichimaru-Suematsu, Miki; Washio, Ayako; Saito, Noriko; Urata, Mariko; Hanada, Kaori; Morotomi, Takahiko; Kitamura, Chiaki

    2017-08-01

    The purpose of the present study was to compare the clinical efficacy between a flowable-type nano-hybrid composite and a paste-type composite for posterior restoration. Of 62 posterior teeth in 33 patients (mean age: 34.1 years), 31 were filled with a paste-type composite (Heliomolar [HM] group), and another 31 with a flowable nano-hybrid composite (MI FIL [MI] group). Clinical efficacy was evaluated at 2 years after the restoration. There were no differences for retention, surface texture deterioration, anatomical form change, deterioration of marginal adaptation, and secondary caries, while a statistical difference was found for marginal discoloration, which was significantly greater in the HM group (P composites showed that the flowable nano-hybrid composite could be an effective esthetic material for posterior restoration. © 2016 John Wiley & Sons Australia, Ltd.

  12. A constrained particle dynamics for continuum-particle hybrid method in micro-and nano-fluidics

    Institute of Scientific and Technical Information of China (English)

    Jia Cui; GuoWei He; Dewei Qi

    2006-01-01

    A hybrid method of continuum and particle dynamics is developed for micro- and nano-fluidics,where fluids are described by a molecular dynamics (MD) in one domain and by the Navier-Stokes (NS) equations in another domain.In order to ensure the continuity of momentum flux,the continuum and molecular dynamics in the overlap domain are coupled through a constrained particle dynamics.The constrained particle dynamics is constructed with a virtual damping force and a virtual added mass force.The sudden-start Couette flows with either non-Slip or slip boundary condition are used to test the hybrid method.It is shown that the results obtained are quantitatively in agreement with the analytical solutions under the non-slip boundary conditions and the full MD simulations under the slip boundary conditions.

  13. Electrochemical sensing of DNA immobilization and hybridization based on carbon nanotubes/nano zinc oxide/chitosan composite film

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang; Tao Yang; Da Ming Huang; Kui Jiao

    2008-01-01

    A novel electrochemical DNA biosensor based on zinc oxide (ZnO) nanoparticles and multi-walled carbon nanotubes (MWNTs)for DNA immobilization and enhanced hybridization detection is presented. The MWNTs/nano ZnO/chitosan composite filmmodified glassy carbon electrode (MWNTs/ZnO/CHIT/GCE) was fabricated and DNA probes were immobilized on the electrodesurface. The hybridization events were monitored by differential pulse voltammetry (DPV) using methylene blue (MB) as anindicator. The sensor can effectively discriminate different DNA sequences related to PAT gene in the.transgenic corn, with adetection limit of 2.8×10-12 mol/L of target sequence.2008 Kui Jiao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  14. 宽谐振区光学纳米天线的谐振%Resonance of optical nano-antenna with wider resonant areas

    Institute of Scientific and Technical Information of China (English)

    袁纵横; 苏睿; 黄静

    2013-01-01

    提出了一种有双谐振频率和较宽谐振区域的纳米天线结构.利用有限积分法,计算了由金构成的表面等离子体光学纳米天线的谐振特性,研究了在谐振区域内谐振频率和谐振电场随位置变化的情况.结果表明,在不同谐振频率下存在两个谐振电场,在中间区域,谐振频率为270 THz,在侧边间隙区,谐振频率为390 THz;激励源为1 V/m时,其谐振电场均达700 V/m以上,是普通偶极子天线的18倍;第一谐振区域的谐振场集中在10~25 nm,在此范围内,谐振电场较大、谐振频率几乎不变;加上折射率为1.5的玻璃衬底后,天线的谐振电场达到800 V/m,与没有衬底时相比,谐振频率变化很小.研究的天线结构在高性能的光学纳米天线、太阳能电池和生物传感器方面有潜在的应用价值.%A nano-antenna with two resonant frequencies and wider resonant areas was constructed.On the basis of the finite integral method,the resonant properties of the surface plasmon optical nano-antenna constructed by Au were calculated and the resonant frequencies and resonant fields in resonant areas were mainly simulated.The experiments show that there are two resonant areas in different resonant frequencies,which are 270 THz at the middle gap and 390 THz at the side gap.Their resonant electric fields are up to 700 V/m,which is about 18 times higher than that of the common dipole antenna when the excitation field is 1 V/m.The resonance field at the first resonant area is confined at the central part from 10 nm to 25 nm along the Z-axis direction,the resonant frequency is almost not changed and the magnitude is greater.The structure with a glass substrate of refraction index of 1.5 is also considered,the resonant field is up to 800 V/m,whereas the resonant center frequencies are almost not changed.The proposed structure has potential applications to high-quality optical antennas,solar cells,and biosensors.

  15. Spectrometer sensor using patterned nano-structure plasmon resonance grating (Conference Presentation)

    Science.gov (United States)

    Guo, Hong; Tian, Xueli; Guo, Junpeng

    2016-03-01

    Localized surface plasmon resonance has been extensively investigated for biochemical sensor applications. In traditional localized surface plasmon resonance biosensors, resonance spectra were measured in the reflection or transmission from the nanostructure devices. In this work, we demonstrate a new surface plasmon resonance sensor platform with which the localized surface plasmon resonance and shift were measured by using a CCD imager instead of using an optical spectrometer. In additional to the metal nanostructures which support localized plasmon resonance, we pattern the nanostructures into diffraction gratings with super-wavelength grating periods. The nanostructure diffraction gratings support localized plasmon resonance and also diffract localized plasmon resonance radiations into non-zeroth order diffractions. Plasmon resonance spectrum and shift are measured with a CCD imager in one of the diffraction orders. The new plasmon resonance spectrometer sensor combines the functions of sensing and spectral analysis into one apparatus and is capable of real-time visualization of the biochemical bonding process with an imager.

  16. Grid-connected Photovoltaic Micro-inverter with New Hybrid Control LLC Resonant Converter

    DEFF Research Database (Denmark)

    Xingkui, Mao; Qisheng, Huang; Qingbo, Ke;

    2016-01-01

    A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse...... power of 250W and output voltage of 220VAC/50Hz. The experiment shows that the peak efficiency of the PVMI is 95.5%, where efficiency of LLC converter is up to 97.7%, and the MPPT accuracy is more than 99%. Thus the validity of the proposed system structure, design and control method is verified....

  17. The influence of hierarchical hybrid micro/nano-textured titanium surface with titania nanotubes on osteoblast functions.

    Science.gov (United States)

    Zhao, Lingzhou; Mei, Shenglin; Chu, Paul K; Zhang, Yumei; Wu, Zhifen

    2010-07-01

    Hierarchical hybrid micro/nano-textured titanium surface topographies with titania nanotubes were produced by simple acid etching followed by anodization to mimic the hierarchical structure of bone tissues. Primary rat osteoblasts were used to evaluate the bioactivity. The microtopography formed by acid etching of titanium induced inconsistent osteoblast functions with initial cell adhesion and osteogenesis-related gene expression being dramatically enhanced while other cell behaviors such as proliferation, intracellular total protein synthesis and alkaline phosphatase activity, collagen secretion, and extracellular matrix mineralization being depressed. In comparison, addition of nanotubes to the microtopography led to enhancement of multiple osteoblast functions. Nearly all the cell functions investigated in this study were retained or promoted. Compared to a microtopography, the enhancement of multiple cell functions observed from the hierarchical micro/nano-textured surfaces is expected to lead to faster bone maturation around the titanium implants without compromising the bone mass. In addition, the hierarchical micro/nano-textured surfaces still retain the mechanical interlocking ability of the microtopography thereby boding well for osseointegration. Our study reveals a synergistic role played by the micro and nanotopographies in osteoblast functions and provides insight to the design of better biomedical implant surfaces.

  18. Superconducting Resonator-Rydberg Atom Hybrid in the Strong Coupling Regime

    CERN Document Server

    Yu, Deshui; Valado, Maria Martinez; Hufnagel, Christoph; Kwek, Leong Chuan; Amico, Luigi; Dumke, Rainer

    2016-01-01

    We propose a promising hybrid quantum system, where a highly-excited atom strongly interacts with a superconducting LC oscillator via the electric field of capacitor. An external electrostatic field is applied to tune the energy spectrum of atom. The atomic qubit is implemented by two eigenstates near an avoided-level crossing in the DC Stark map of Rydberg atom. Varying the electrostatic field brings the atomic-qubit transition on- or off-resonance to the microwave resonator, leading to a strong atom-resonator coupling with an extremely large cooperativity. Like the nonlinearity induced by Josephson junctions in superconducting circuits, the large atom-resonator interface disturbs the harmonic potential of resonator, resulting in an artificial two-level particle. Different universal two-qubit logic gates can also be performed on our hybrid system within the space where an atomic qubit couples to a single photon with an interaction strength much larger than any relaxation rates, opening the door to the cavity...

  19. Superconducting resonator and Rydberg atom hybrid system in the strong coupling regime

    Science.gov (United States)

    Yu, Deshui; Landra, Alessandro; Valado, María Martínez; Hufnagel, Christoph; Kwek, Leong Chuan; Amico, Luigi; Dumke, Rainer

    2016-12-01

    We propose a promising hybrid quantum system, where a highly excited atom strongly interacts with a superconducting L C oscillator via the electric field of capacitor. An external electrostatic field is applied to tune the energy spectrum of the atom. The atomic qubit is implemented by two eigenstates near an avoided-level crossing in the dc Stark map of a Rydberg atom. Varying the electrostatic field brings the atomic-qubit transition on or off resonance with respect to the microwave resonator, leading to a strong atom-resonator coupling with an extremely large cooperativity. Like the nonlinearity induced by Josephson junctions in superconducting circuits, the large atom-resonator interface disturbs the harmonic potential of the resonator, resulting in an artificial two-level particle. Different universal two-qubit logic gates can also be performed on our hybrid system within the space where an atomic qubit couples to a single photon with an interaction strength much larger than any relaxation rates, opening the door to the cavity-mediated state transmission.

  20. Hybrid micro/nano-structure formation by angular laser texturing of Si surface for surface enhanced Raman scattering.

    Science.gov (United States)

    Xu, Kaichen; Zhang, Chentao; Zhou, Rui; Ji, Rong; Hong, Minghui

    2016-05-16

    Surface enhanced Raman spectroscopy (SERS) has drawn much research interest in the past decades as an efficient technique to detect low-concentration molecules. Among many technologies, which can be used to fabricate SERS substrates, laser ablation is a simple and high-speed method to produce large-area SERS substrates. This work investigates the angular texturing effect by dynamic laser ablation and its influence on SERS signals. By tuning the angle between the Si surface and laser irradiation, the distributions and sizes of laser induced hybrid micro/nano-structures are studied. By decorating with a silver film, plenty of hot spots can be created among these structures for SERS. It is found that when the incident laser angle is 15° at the laser fluence of 16.0 J/cm2, the SERS performance is well optimized. This work realizes antisymmetric distribution of nanoparticles deposited on Si surface, which provides a flexible tuning of the hybrid micro/nano-structures' fabrication with high controllability for practical applications.

  1. Preparation, characterization and luminescent properties of dense nano-silica hybrids loaded with 1,8-naphthalic anhydride.

    Science.gov (United States)

    Wang, Jinpeng; Sun, Jihong; Li, Yuzhen; Wang, Feng

    2014-03-01

    Novel luminescent dense nano-silica hybrid materials (DNSS) modified with different amounts of (3-aminopropyl)triethoxysilane (APTES) and 1,8-naphthalic anhydride (NA) were successfully synthesized via two steps combined with post-grafting methods. Powder X-ray diffraction (XRD), N2-sorption analysis, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), photoluminescence (PL) spectroscopy and elemental analysis, as well as time-resolved decays were employed to characterize the resultant hybrid materials. The results revealed that luminescent organic molecules had been successfully loaded onto the amine-modified surface of nano-silica spheres. In addition, their fluorescence intensity and characteristic peak of emission spectra changed with increasing amount of APTES and NA additive. In particular, the characteristic peak showed a red shift from 390 to 450 nm, however, this was inconsistent with results calculated on the basis of the elemental analysis data, most probably because of the dispersion behaviors of NA molecules from the aggregating to the monolayer state. These observations demonstrated the existence of a quantum confinement effectiveness of NA-DNSS samples, and therefore a possible mechanism was put forward.

  2. Luminescent Eosin Y–SiO{sub 2} hybrid nano and microrods prepared by sol–gel template method

    Energy Technology Data Exchange (ETDEWEB)

    Secu, M., E-mail: msecu@infim.ro [National Institute for Materials Physics, P.O. Box MG-7, Bucharest–Magurele, 077125 (Romania); Secu, C.E.; Sima, M.; Negrea, R.F.; Bartha, C. [National Institute for Materials Physics, P.O. Box MG-7, Bucharest–Magurele, 077125 (Romania); Dinescu, M.; Damian, V. [National Institute for Laser, Plasma and Radiation, P.O. Box MG-36, Bucharest–Magurele 077125 (Romania)

    2013-11-15

    Sol–gel chemistry within the pores of a polycarbonate template membrane was used for the preparation of Eosin Y–SiO{sub 2} hybrid nano- and microrods, using tetraethylorthosilicate [TEOS, Si(OC{sub 2}H{sub 5}){sub 4}] as the precursor in the presence of trifluoroacetic acid (TFA) catalyst. The ethanolic solution of Eosin-Y was added to the silica sol to trap dye molecules inside the SiO{sub 2} gel network during the gelation. Structural and morphological characterization using scanning electron microscopy (SEM) and luminescence microscopy have shown the formation of rods with 200 nm and 1.2 μm diameter and about 30 μm length, exhibiting luminescence properties. Spectroscopic characterization has shown that the luminescence is due to Eosin-Y molecule in the xerogel porous network, surrounded by a solvation shell given mainly by the water. -- Highlights: • Sol–gel template method was used to prepare Eosin Y–SiO{sub 2} hybrid rods-type structures. • Morphological characterization has shown nano- and microrods with luminescent properties. • Luminescence is due to Eosin-Y molecule surrounded by a solvation shell given by water.

  3. Molecular dynamics simulations on the relationship between the elastic parameters and the molecular structures of nano-hybrid POSS materials

    Institute of Scientific and Technical Information of China (English)

    ZENG Fan-lin; SUN Yi; HU Li-jiang

    2006-01-01

    To research the relationship between the elastic parameters and the molecular structures of nano hybrid polyhedral oligomeric silsesquioxanes (POSS) materials, the mechanical properties at different temperatures for three POSS polymers with different molecular architectures, polymerlized norbornene POSS homopolymer (PNPOSS, pedant architecture), γ - (2, 3 glycidoxy) propyl diaminoethane POSS polymer (GPDP, catena architecture) and trimethoxysilylcyclopentyl POSS polymer (TSCP, cage -cage network architecture) were obtained by molecular dynamics simulations based on the Compass force-field. Results indicate that the molecular architectures of the POSS polymers have great influence on the reinforced effects. The effect of the cage-cage network architecture is best, while that of the catena architecture takes second place and the pedant architecture has the least influence comparatively. The reinforced effects of the POSS monomers were examined. The influences of the temperatures on these effects were analyzed also. It may provide some basis for the reasonable applications of the excellent mechanical properties of the organic-inorganic nano-hybrid materials. It may also provide references for exploitation and design of the POSS materials.

  4. Spectrophotometric Evaluation of Colour Stability of Nano Hybrid Composite Resin in Commonly Used Food Colourants in Asian Countries

    Science.gov (United States)

    Sajjan, Girija S; Varma Kanumuri, Madhu

    2017-01-01

    Introduction There is growing interest in colour stability of aesthetic restorations. So far few studies have been reported. Aim This study was designed to investigate the effects of different common food colourants i.e., Turmeric and Carmoisine (orange red dye) consumed by patients in Asian countries on a recent nano hybrid composite resin. Materials and Methods A total of sixty disk shaped specimens measuring 10 mm in diameter and 2 mm in thickness were prepared. The samples were divided into two groups {Z 100 (Dental restorative composite) Filtek Z 250 XT (Nano hybrid universal restorative)}. Baseline colour measurement of all specimens were made using reflectance spectrophotometer with CIE L*a*b* system. Specimens were immersed in artificial saliva and different experimental solutions containing food colourants (carmoisine solution and turmeric solution) for three hours per day at 37°C. Colour measurements were made after 15 days. Colour difference (ΔE*) was calculated. Mean values were compared by one-way analysis of variance (ANOVA). Multiple range test by Tukey Post-hoc test procedure was employed to identify the significant groups at 5% level. Results Z 100 showed minimum staining capacity when compared to Z 250 XT in both the colourant solutions. Conclusion The nanohybrid composite resin containing TEGDMA showed significant colour change when compared to that of microhybrid composite resin as a result of staining in turmeric and carmoisine solution. PMID:28274047

  5. Gold Nano Popcorn Attached SWCNT Hybrid Nanomaterial for Targeted Diagnosis and Photothermal Therapy of Human Breast Cancer Cells

    Science.gov (United States)

    Beqa, Lule; Fan, Zhen; Singh, Anant Kumar; Senapati, Dulal; Ray, Paresh Chandra

    2011-01-01

    Breast cancer presents greatest challenge in health care in today’s world. The key to ultimately successful treatment of breast cancer disease is an early and accurate diagnosis. Current breast cancer treatments are often associated with severe side effects. Driven by the need, we report the design of novel hybrid nanomaterial using gold nano popcorn-attached single wall carbon nanotube for targeted diagnosis and selective photothermal treatment. Targeted SK-BR-3 human breast cancer cell sensing have been performed in 10 cancer cells/mL level, using surface enhanced Raman scattering of single walls carbon nanotube’s D and G bands. Our data show that S6 aptamer attached hybrid nanomaterial based SERS assay is highly sensitive to targeted human breast cancer SK-BR-3 cell line and it will be able to distinguish it from other non targeted MDA-MB breast cancer cell line and HaCaT normal skin cell line. Our results also show that 10 minutes of photothermal therapy treatment by 1.5 W/cm2 power, 785 nm laser is enough to kill cancer cells very effectively using S6 aptamer attached hybrid nanomaterials. Possible mechanisms for targeted sensing and operating principle for highly efficient photothermal therapy have been discussed. Our experimental results reported here open up a new possibility for using aptamers modified hybrid nanomaterial for reliable diagnosis and targeted therapy of cancer cell lines quickly. PMID:21842867

  6. Gold nano-popcorn attached SWCNT hybrid nanomaterial for targeted diagnosis and photothermal therapy of human breast cancer cells.

    Science.gov (United States)

    Beqa, Lule; Fan, Zhen; Singh, Anant Kumar; Senapati, Dulal; Ray, Paresh Chandra

    2011-09-01

    Breast cancer presents greatest challenge in health care in today's world. The key to ultimately successful treatment of breast cancer disease is an early and accurate diagnosis. Current breast cancer treatments are often associated with severe side effects. Driven by the need, we report the design of novel hybrid nanomaterial using gold nano popcorn-attached single wall carbon nanotube for targeted diagnosis and selective photothermal treatment. Targeted SK-BR-3 human breast cancer cell sensing have been performed in 10 cancer cells/mL level, using surface enhanced Raman scattering of single walls carbon nanotube's D and G bands. Our data show that S6 aptamer attached hybrid nanomaterial based SERS assay is highly sensitive to targeted human breast cancer SK-BR-3 cell line and it will be able to distinguish it from other non targeted MDA-MB breast cancer cell line and HaCaT normal skin cell line. Our results also show that 10 min of photothermal therapy treatment by 1.5 W/cm(2) power, 785 nm laser is enough to kill cancer cells very effectively using S6 aptamer attached hybrid nanomaterials. Possible mechanisms for targeted sensing and operating principle for highly efficient photothermal therapy have been discussed. Our experimental results reported here open up a new possibility for using aptamers modified hybrid nanomaterial for reliable diagnosis and targeted therapy of cancer cell lines quickly.

  7. Magneto-optic transmittance modulation observed in a hybrid graphene–split ring resonator terahertz metasurface

    Energy Technology Data Exchange (ETDEWEB)

    Zanotto, Simone; Pitanti, Alessandro [NEST, Istituto Nanoscienze–CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa (Italy); Lange, Christoph; Maag, Thomas; Huber, Rupert [Department of Physics, University of Regensburg, 93040 Regensburg (Germany); Miseikis, Vaidotas; Coletti, Camilla [CNI@NEST, Istituto Italiano di Tecnologia, P.za S. Silvestro 12, 56127 Pisa (Italy); Degl' Innocenti, Riccardo [Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Baldacci, Lorenzo [Scuola Superiore Sant' Anna, Institute of Life Sciences, P.za Martiri della Libertà 33, 56127 Pisa (Italy); Tredicucci, Alessandro [NEST, Istituto Nanoscienze-CNR and Dipartimento di Fisica “E. Fermi,” Università di Pisa, L.go Pontecorvo 3, 56127 Pisa (Italy)

    2015-09-21

    By placing a material in close vicinity of a resonant optical element, its intrinsic optical response can be tuned, possibly to a wide extent. Here, we show that a graphene monolayer, spaced a few tenths of nanometers from a split ring resonator metasurface, exhibits a magneto-optical response which is strongly influenced by the presence of the metasurface itself. This hybrid system holds promises in view of thin optical modulators, polarization rotators, and nonreciprocal devices, in the technologically relevant terahertz spectral range. Moreover, it could be chosen as the playground for investigating the cavity electrodynamics of Dirac fermions in the quantum regime.

  8. Development of a Hybrid Magnetic Resonance and Ultrasound Imaging System

    Directory of Open Access Journals (Sweden)

    Victoria Sherwood

    2014-01-01

    Full Text Available A system which allows magnetic resonance (MR and ultrasound (US image data to be acquired simultaneously has been developed. B-mode and Doppler US were performed inside the bore of a clinical 1.5 T MRI scanner using a clinical 1–4 MHz US transducer with an 8-metre cable. Susceptibility artefacts and RF noise were introduced into MR images by the US imaging system. RF noise was minimised by using aluminium foil to shield the transducer. A study of MR and B-mode US image signal-to-noise ratio (SNR as a function of transducer-phantom separation was performed using a gel phantom. This revealed that a 4 cm separation between the phantom surface and the transducer was sufficient to minimise the effect of the susceptibility artefact in MR images. MR-US imaging was demonstrated in vivo with the aid of a 2 mm VeroWhite 3D-printed spherical target placed over the thigh muscle of a rat. The target allowed single-point registration of MR and US images in the axial plane to be performed. The system was subsequently demonstrated as a tool for the targeting and visualisation of high intensity focused ultrasound exposure in the rat thigh muscle.

  9. Hybridizing micro-Ti with nano-B4C particulates to improve the microstructural and mechanical characteristics of Mg–Ti composite

    Directory of Open Access Journals (Sweden)

    S. Sankaranarayanan

    2014-03-01

    Full Text Available In this study, the effects of hybridizing micron-sized titanium particles with nano-sized boron carbide particles on the microstructural and mechanical properties of Mg–Ti composite were investigated. Microstructural characterization revealed grain refinement attributed to the presence of uniformly distributed micro-Ti particles embedded with nano-B4C particulates. Electron back scattered diffraction (EBSD analyses of the Mg–(Ti + B4CBM hybrid composite showed relatively more localized recrystallized grains and lesser tensile twin fraction, when compared to Mg–Ti. The evaluation of mechanical properties indicated that the best combination of strength and ductility was observed in the Mg–(Ti + B4CBM hybrid composite. The superior properties of the Mg–(Ti + B4CBM hybrid composite when compared to Mg–Ti can be attributed to the presence of nano-reinforcement, the uniform distribution of the hybridized particles and the better interfacial bonding between the matrix and the reinforcement particles achieved by nano-B4C addition.

  10. Hybridized plasmon resonant modes in molecular metallodielectric quad-triangles nanoantenna

    Science.gov (United States)

    Ahmadivand, Arash; Sinha, Raju; Pala, Nezih

    2015-11-01

    In this study, we examined the plasmon response for both metallic and metallodielectric nanoantennas composed of four gold (Au) triangles in a quadrumer orientation. Tailoring an artificial metallic quad-triangles nanoantenna, it is shown that the structure is able to support pronounced plasmon and Fano resonances in the visible spectrum. Using plasmon transmutation effect, we showed that the plasmonic response of the proposed cluster can be enhanced with the placement of carbon nanoparticles in the offset gaps between the proximal triangles. It is verified that this structural modification gives rise to formation of new collective magnetic antibonding (dark) plasmon modes. Excitation of these subradiant dark modes leads to formation of narrower and deeper Fano resonances in the spectral response of the metallodielectric nanoantenna. To investigate the practical applications of the metallodielectric structure, we immersed the nano-assembly in various liquids with different refractive indices to define its sensitivity to the environmental perturbation as a plasmonic biological sensor.

  11. Microwave resonant activation in hybrid single-gap/two-gap Josephson tunnel junctions

    Science.gov (United States)

    Carabello, Steven; Lambert, Joseph G.; Mlack, Jerome; Dai, Wenqing; Li, Qi; Chen, Ke; Cunnane, Daniel; Xi, X. X.; Ramos, Roberto C.

    2016-09-01

    Microwave resonant activation is a powerful, straightforward technique to study classical and quantum systems, experimentally realized in Josephson junction devices cooled to very low temperatures. These devices typically consist of two single-gap superconductors separated by a weak link. We report the results of the first resonant activation experiments on hybrid thin film Josephson junctions consisting of a multi-gap superconductor (MgB2) and a single-gap superconductor (Pb or Sn). We can interpret the plasma frequency in terms of theories both for conventional and hybrid junctions. Using these models, we determine the junction parameters including critical current, resistance, and capacitance and find moderately high quality factors of Q0˜ 100 for these junctions.

  12. Hybrid resonance and long-time asymptotic of the solution to Maxwell's equations

    CERN Document Server

    Després, Bruno

    2015-01-01

    We study the long-time asymptotic of the solutions to Maxwell's equation in the case of a hybrid resonance in the cold plasma model. We base our analysis in the transfer to the time domain of the recent results of B. Despr\\'es, L.M. Imbert-G\\'erard and R. Weder, J. Math. Pures Appl. {\\bf 101} ( 2014) 623-659, where the singular solutions to Maxwell's equations in the frequency domain where constructed by means of a limiting absorption principle and a formula for the heating of the plasma in the limit of vanishing collision frequency was obtained. Currently there is considerable interest in these problems because hybrid resonances are a possible scenario for the heating of plasmas in the future ITER Tokamak.

  13. Hybrid resonance and long-time asymptotic of the solution to Maxwell's equations

    Science.gov (United States)

    Després, Bruno; Weder, Ricardo

    2016-03-01

    We study the long-time asymptotic of the solutions to Maxwell's equation in the case of an upper-hybrid resonance in the cold plasma model. We base our analysis in the transfer to the time domain of the recent results of B. Després, L.M. Imbert-Gérard and R. Weder (2014) [15], where the singular solutions to Maxwell's equations in the frequency domain were constructed by means of a limiting absorption principle and a formula for the heating of the plasma in the limit of vanishing collision frequency was obtained. Currently there is considerable interest in these problems, in particular, because upper-hybrid resonances are a possible scenario for the heating of plasmas, and since they can be a model for the diagnostics involving wave scattering in plasmas.

  14. Ultra-Small Dualband Dualmode Microstrip Antenna Based on Novel Hybrid Resonator

    Science.gov (United States)

    Zhu, Ji-Xu; Bai, Peng; Zheng, Hao-Zhong

    2016-11-01

    A novel hybrid resonator consists of right handed patch+composite right and left handed transmission line (RH+CRLH) is proposed for the first time aiming at both compactness and frequency manipulation. A demonstration with theoretical dispersion relations and EM simulation is provided for the correctness and efficiency. According to the new method, an ultra-small and dualband antenna operating around 2.4 GHz (n=0, Bluetooth band) and 3.5 GHz (n=+1, Wimax band) is designed, fabricated and measured, whose occupied area is only of 0.158 λ_0. Numerical and experimental results indicate that the antenna exhibits a good impendence match, low cross-polarization and comparable radiation gains in both bands. Excellent performances of the antennas based on hybrid resonators predict promising applications in multifunction wireless communication systems.

  15. Bidirectionally tunable all-optical switch based on multiple nano-structured resonators using backward quasi-phase-matching

    Institute of Scientific and Technical Information of China (English)

    Jun Xie; Yuping Chen; Wenjie Lu; Xianfeng Chen

    2011-01-01

    @@ Based on the second-order nonlinearity, we present a bidirectional tunable all-optical switch at C-band by introducing backward quasi-phase-matching technique in Mg-doped periodically poled lithium niobate (MgO:PPLN) waveguide with a nano-8tructure called multiple resonators.Two injecting forward lights and one backward propagating light interact with difference frequency generations.The transmission of forward signal and backward idler light can be modulated simultaneously with the variation of control light power based on the basic "phase shift" structure of a single resonator.In this scheme, all the results come from our simulation, The speed of tlus bidirectional optical switch can reach to femtosecond if a femtosecond laser is used as the control light.%Based on the second-order nonlinearity, we present a bidirectional tunable all-optical switch at C-band by introducing backward quasi-phase-matching technique in Mg-doped periodically poled lithium niobate (MgO:PPLN) waveguide with a nano-structure called multiple resonators.Two injecting forward lights and one backward propagating light interact with difference frequency generations.The transmission of forward signal and backward idler light can be modulated simultaneously with the variation of control light power based on the basic "phase shift" structure of a single resonator.In this scheme, all the results come from our simulation.The speed of this bidirectional optical switch can reach to femtosecond if a femtosecond laser is used as the control light.

  16. Partially end-pumped Nd:YAG slab laser with a hybrid resonator.

    Science.gov (United States)

    Du, K; Wu, N; Xu, J; Giesekus, J; Loosen, P; Poprawe, R

    1998-03-01

    A Nd:YAG slab is partially end pumped by a diode laser stack with three diode laser bars. The pumped volume has a rectangular cross section. A hybrid resonator, which is stable in the plane of small dimension and is off-axis unstable in the plane of large dimension of the gain cross section, was used to yield highly efficient laser operation at diffraction-limited beam quality. The laser design and experimental results are reported.

  17. Polarization dependence of the metamagnetic resonance of cut-wire-pair structure by using plasmon hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Dung, Nguyen Van; Yoo, Young Joon; Lee, Young Pak [Hanyang University, Seoul (Korea, Republic of); Tung, Nguyen Thanh [KU Leuven, Leuven (Belgium); Tung, Bui Son; Lam, Vu Dinh [Vietnam Academy of Science and Technology, Hanoi (Viet Nam)

    2014-07-15

    The influence of lattice constants on the electromagnetic behavior of a cut-wire-pair (CWP) structure has been elucidated. In this report, we performed both simulations and experiments to determine the influence of polarization on the metamagnetic resonance of the CWP structure. The key finding is the result of an investigation on the plasmon hybridization between the two CWs, which showed that the polarization of the incident wave was affected. Good agreement between numerical simulation and measurement is achieved.

  18. Development of a surface plasmon resonance and nanomechanical biosensing hybrid platform for multiparametric reading

    Science.gov (United States)

    Alvarez, Mar; Fariña, David; Escuela, Alfonso M.; Sendra, Jose Ramón; Lechuga, Laura M.

    2013-01-01

    We have developed a hybrid platform that combines two well-known biosensing technologies based on quite different transducer principles: surface plasmon resonance and nanomechanical sensing. The new system allows the simultaneous and real-time detection of two independent parameters, refractive index change (Δn), and surface stress change (Δσ) when a biomolecular interaction takes place. Both parameters have a direct relation with the mass coverage of the sensor surface. The core of the platform is a common fluid cell, where the solution arrives to both sensor areas at the same time and under the same conditions (temperature, velocity, diffusion, etc.).The main objective of this integration is to achieve a better understanding of the physical behaviour of the transducers during sensing, increasing the information obtained in real time in one single experiment. The potential of the hybrid platform is demonstrated by the detection of DNA hybridization.

  19. Development of a surface plasmon resonance and nanomechanical biosensing hybrid platform for multiparametric reading.

    Science.gov (United States)

    Alvarez, Mar; Fariña, David; Escuela, Alfonso M; Sendra, Jose Ramón; Lechuga, Laura M

    2013-01-01

    We have developed a hybrid platform that combines two well-known biosensing technologies based on quite different transducer principles: surface plasmon resonance and nanomechanical sensing. The new system allows the simultaneous and real-time detection of two independent parameters, refractive index change (Δn), and surface stress change (Δσ) when a biomolecular interaction takes place. Both parameters have a direct relation with the mass coverage of the sensor surface. The core of the platform is a common fluid cell, where the solution arrives to both sensor areas at the same time and under the same conditions (temperature, velocity, diffusion, etc.).The main objective of this integration is to achieve a better understanding of the physical behaviour of the transducers during sensing, increasing the information obtained in real time in one single experiment. The potential of the hybrid platform is demonstrated by the detection of DNA hybridization.

  20. Hybrid resonance and long-time asymptotic of the solution to Maxwell's equations

    Energy Technology Data Exchange (ETDEWEB)

    Després, Bruno, E-mail: despres@ann.jussieu.fr [Laboratory Jacques Louis Lions, University Pierre et Marie Curie, Paris VI, Boîte courrier 187, 75252 Paris Cedex 05 (France); Weder, Ricardo, E-mail: weder@unam.mx [Departamento de Física Matemática, Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Apartado Postal 20-126, DF 01000 (Mexico)

    2016-03-22

    We study the long-time asymptotic of the solutions to Maxwell's equation in the case of an upper-hybrid resonance in the cold plasma model. We base our analysis in the transfer to the time domain of the recent results of B. Després, L.M. Imbert-Gérard and R. Weder (2014) [15], where the singular solutions to Maxwell's equations in the frequency domain were constructed by means of a limiting absorption principle and a formula for the heating of the plasma in the limit of vanishing collision frequency was obtained. Currently there is considerable interest in these problems, in particular, because upper-hybrid resonances are a possible scenario for the heating of plasmas, and since they can be a model for the diagnostics involving wave scattering in plasmas. - Highlights: • The upper-hybrid resonance in the cold plasma model is considered. • The long-time asymptotic of the solutions to Maxwell's equations is studied. • A method based in a singular limiting absorption principle is proposed.

  1. Coherent resonance of quantum plasmons in Stone-Wales defected graphene-silver nanowire hybrid system

    Science.gov (United States)

    Liu, Tong; Zhang, Hong; Cheng, Xin-Lu; Xu, Yang

    2017-10-01

    Defected graphene has a more important practical significance than graphene. Silver nanoparticles can modify the optical properties of defected graphene. We present herein a detailed theoretical analysis about the coherent resonance of quantum plasmons in the Stone-Wales (SW) defected graphene-silver nanowire hybrid system by using time-dependent density functional theory. The plasmon coherent effect is mainly attributed to the electromagnetic field coupling between the Stone-Wales defected graphene and silver nanowires. As a result, the optical response of the hybrid system exhibits a remarkable enhancement. Plasmon resonance, which depends on polarization and selectable tuning, is enhanced in wide frequency regions. Moreover, it reveals that the resonance frequency of an optical absorption spectrum depends on the space configuration of the SW defected graphene in the hybrid system. This investigation provides a better understanding of the plasmon enhancement effect used in a graphene-based photoelectric device. The study also offers an effective means of detecting the defects existing in graphene.

  2. Mode conversion and electron heating near the upper hybrid resonance frequency

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.L.; Okuda, H.; Abe, H.

    1983-11-01

    Mode conversion near the upper hybrid resonance frequency and electron heating are studied using a one-dimensional electromagnetic relativistic particle code. It is found that for a sufficiently small pump field E/sub 0/, E/sub 0//sup 2//4..pi..nT/sub e/ less than or equal to 0.01, electron heating is localized in a region near the electron cyclotron layer where the pump frequency is equal to the local electron gyrofrequency. For stronger pump fields, electron heating takes place more or less uniformly across a region between the upper hybrid resonance layer and the cyclotron layer. In addition, a significant fraction of electromagnetic energy associated with the pump is found to be reflected back into the vacuum from a region in the plasma near the upper hybrid resonance layer for both strong (E/sub 0//sup 2//4..pi..nT/sub e/ approx. = 1) and weak pumps (E/sub 0//sup 2//4..pi..nT/sub e/ << 1).

  3. Wide wavelength range tunable one-dimensional silicon nitride nano-grating guided mode resonance filter based on azimuthal rotation

    Science.gov (United States)

    Yukino, Ryoji; Sahoo, Pankaj K.; Sharma, Jaiyam; Takamura, Tsukasa; Joseph, Joby; Sandhu, Adarsh

    2017-01-01

    We describe wavelength tuning in a one dimensional (1D) silicon nitride nano-grating guided mode resonance (GMR) structure under conical mounting configuration of the device. When the GMR structure is rotated about the axis perpendicular to the surface of the device (azimuthal rotation) for light incident at oblique angles, the conditions for resonance are different than for conventional GMR structures under classical mounting. These resonance conditions enable tuning of the GMR peak position over a wide range of wavelengths. We experimental demonstrate tuning over a range of 375 nm between 500 nm˜875 nm. We present a theoretical model to explain the resonance conditions observed in our experiments and predict the peak positions with show excellent agreement with experiments. Our method for tuning wavelengths is simpler and more efficient than conventional procedures that employ variations in the design parameters of structures or conical mounting of two-dimensional (2D) GMR structures and enables a single 1D GMR device to function as a high efficiency wavelength filter over a wide range of wavelengths. We expect tunable filters based on this technique to be applicable in a wide range of fields including astronomy and biomedical imaging.

  4. Wide wavelength range tunable one-dimensional silicon nitride nano-grating guided mode resonance filter based on azimuthal rotation

    Directory of Open Access Journals (Sweden)

    Ryoji Yukino

    2017-01-01

    Full Text Available We describe wavelength tuning in a one dimensional (1D silicon nitride nano-grating guided mode resonance (GMR structure under conical mounting configuration of the device. When the GMR structure is rotated about the axis perpendicular to the surface of the device (azimuthal rotation for light incident at oblique angles, the conditions for resonance are different than for conventional GMR structures under classical mounting. These resonance conditions enable tuning of the GMR peak position over a wide range of wavelengths. We experimental demonstrate tuning over a range of 375 nm between 500 nm˜875 nm. We present a theoretical model to explain the resonance conditions observed in our experiments and predict the peak positions with show excellent agreement with experiments. Our method for tuning wavelengths is simpler and more efficient than conventional procedures that employ variations in the design parameters of structures or conical mounting of two-dimensional (2D GMR structures and enables a single 1D GMR device to function as a high efficiency wavelength filter over a wide range of wavelengths. We expect tunable filters based on this technique to be applicable in a wide range of fields including astronomy and biomedical imaging.

  5. Research on Hybrid Isolation System for Micro-Nano-Fabrication Platform

    Directory of Open Access Journals (Sweden)

    Jie Fu

    2014-06-01

    Full Text Available In order to obtain better vibration suppression effect, this paper designs a semiactive/fully active hybrid isolator by using magnetorheological elastomer (MRE and piezoelectric material. Combined with multimode control scheme, full frequency vibration suppression is achieved. Firstly, series type structure is determined for the hybrid isolator, and the structure of hybrid isolator is designed. Next, the dynamic model of hybrid isolator is derived, the dynamic characteristics measurement for MRE isolator and piezoelectric stack actuator (PSA is established, and parameters such as voltage-displacement coefficient, stiffness and damping constant are identified from the experimental results, respectively. Meanwhile, the switch frequency is determined by experimental results of PSA and MRE isolator. Lastly, influence of the stiffness of MRE, control voltage of PSA, and intermediate mass on hybrid isolator system is analyzed by simulations, and the results show that the hybrid isolator proposed is effective.

  6. Controlled Electromagnetically Induced Transparency and Fano Resonances in Hybrid BEC-Optomechanics

    CERN Document Server

    Yasir, Kashif Ammar

    2015-01-01

    We investigate the controllability of electromagnetically induced transparency (EIT) and Fano resonances in hybrid optomechanical system which is composed of cigar-shaped Bose-Einstein condensate (BEC) trapped inside high-finesse Fabry-P\\'erot cavity driven by a single mode optical field along the cavity axis and a transverse pump field. Here, transverse optical field is used to control the phenomenon of EIT in the output probe laser field. The output probe laser field can efficiently be amplified or attenuated depending on the strength of transverse optical field. Furthermore, we demonstrate the existence of Fano resonances in the output field spectra and discuss the controlled behavior of Fano resonances using transverse optical field. To observe this phenomena in laboratory, we suggest a certain set of experimental parameters.

  7. Hybrid nanocavities for resonant enhancement of color center emission in diamond

    CERN Document Server

    Barclay, Paul E; Santori, Charles; Faraon, Andrei; Beausoleil, Raymond G

    2011-01-01

    Resonantly enhanced emission from the zero phonon line of a diamond nitrogen-vacancy (NV) center in single crystal diamond is demonstrated experimentally using a hybrid whispering gallery mode nanocavity. A 900 nm diameter ring nanocavity formed from gallium phosphide, whose sidewalls extend into a diamond substrate, is tuned onto resonance at low-temperature with the zero phonon line of a negatively charged NV center implanted near the diamond surface. When the nanocavity is on resonance, the zero phonon line intensity is enhanced by approximately an order of magnitude, and the spontaneous emission lifetime of the NV is reduced as much as 18%, corresponding to a 6.3X enhancement of emission in the zero photon line.

  8. Long-range and rapid transport of individual nano-objects by a hybrid electrothermoplasmonic nanotweezer

    DEFF Research Database (Denmark)

    Ndukaife, Justus C.; Kildishev, Alexander V.; Nnanna, Agbai George Agwu;

    2016-01-01

    enables on-demand long-range and rapid delivery of single nano-objects to specific plasmonic nanoantennas, where they can be trapped and even locked in place. We also present a physical model that elucidates the role of both heat-induced fluidic motion and plasmonic field enhancement in the plasmon......-assisted optical trapping process. Finally, by applying a d.c. field or low-frequency a.c. field (below 10 Hz) while the particle is held in the trap by the gradient force, the trapped nano-objects can be immobilized into plasmonic hotspots, thereby providing the potential for effective low-power nanomanufacturing...

  9. Developing a hybrid wind instrument: using a loudspeaker to couple a theoretical exciter to a real resonator

    OpenAIRE

    Buys, K.; D. Sharp; Laney, R.

    2014-01-01

    A hybrid wind instrument generates self-sustained sounds via a real-time interaction between a computed physical model of an exciter (such as human lips interacting with a mouthpiece) and a real acoustic resonator. Successful implementation of a hybrid wind instrument will not only open up new musical possibilities but will also provide a valuable research tool. However, attempts to produce a hybrid instrument have so far fallen short, in terms of both the accuracy and the variation in the so...

  10. Designing of Hybrid Structured Glass Laminated Transparent Nano Composites through Vacuum infusion Technique

    Science.gov (United States)

    Mukherji, A.; Tarapure, N. D.; Wakure, G. N.

    2017-05-01

    Glass is the most commonly used transparent material. However, glass is not suitable in applications where low weight, high strength is required. The present invention comprises a method of making a Transparent Glass Laminated Nano composite product. The product contains a Bidirectionally oriented E-Glass Fabric an essentially bidirectional yarn woven fabrics is stretched Bidirectionally by specially fabricated steel frame associated with both co and counter rotating device. These fibers include glass fibrics/cloths or mixtures of any of these. The synthetic fiber may be any synthetic silica based oven waived bi-directional or Uni-directional fabrics. Engaged gear provided in the device develops uniform tension on fabric, in both direction. Nano particle dispersed resin to be used is formulated with their respective curing agents and extenders. The formulated resin contains 0.1-0.5% of Nano additives and the product composed from 5-10 % of Glass fabric, between 10 to 20 % of ordinary glass, and between 60-80 % of the product is the Nano particles dispersed formulated resin, all measured by volume.

  11. Photophysical efficiency-boost of aqueous aluminium phthalocyanine by hybrid formation with nano-clays.

    Science.gov (United States)

    Staniford, Mark C; Lezhnina, Marina M; Gruener, Malte; Stegemann, Linda; Kuczius, Rauni; Bleicher, Vera; Strassert, Cristian A; Kynast, Ulrich H

    2015-09-11

    Novel organic-inorganic hybrid materials comprising nanoscaled layered silicates and native aluminium hydroxide phthalocyanine (Al(OH)Pc) allowed for the first time the exploitation of their unique photophysical properties in aqueous ambience. In particular, we were able to observe the efficient emission of Al(OH)Pc-nanoclay hybrids and generation of singlet oxygen in aqueous solution.

  12. Synthesis of biocompatible hydrophobic silica-gelatin nano-hybrid by sol-gel process.

    Science.gov (United States)

    Smitha, S; Shajesh, P; Mukundan, P; Nair, T D R; Warrier, K G K

    2007-03-15

    Silica-biopolymer hybrid has been synthesised using colloidal silica as the precursor for silica and gelatin as the biopolymer counterpart. The surface modification of the hybrid material has been done with methyltrimethoxysilane leading to the formation of biocompatible hydrophobic silica-gelatin hybrid. Here we are reporting hydrophobic silica-gelatin hybrid and coating precursor for the first time. The hybrid gel has been evaluated for chemical modification, thermal degradation, hydrophobicity, particle size, transparency under the UV-visible region and morphology. FTIR spectroscopy has been used to verify the presence of CH(3) groups which introduce hydrophobicity to the SiO2-MTMS-gelatin hybrids. The hydrophobic property has also been tailored by varying the concentration of methyltrimethoxysilane. Contact angle by Wilhelmy plate method of transparent hydrophobic silica-gelatin coatings has been found to be as high as approximately 95 degrees . Oxidation of the organic group which induces the hydrophobic character occurs at 530 degrees C which indicates that the surface hydrophobicity is retained up to that temperature. Optical transmittance of SiO2-MTMS-gelatin hybrid coatings on glass substrates has been found to be close to 100% which will enable the hybrid for possible optical applications and also for preparation of transparent biocompatible hydrophobic coatings on biological substrates such as leather.

  13. Hybrid III-V on Si grating as a broadband reflector and a high-Q resonator

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Taghizadeh, Alireza; Park, Gyeong Cheol

    2016-01-01

    Hybrid grating (HG) with a high-refractive-index cap layer added onto a high contrast grating (HCG), can provide a high reflectance close 100 % over a broader wavelength range than HCGs, or work as a ultrahigh quality (Q) factor resonator. The reflection and resonance properties of HGs have been...

  14. Silica xerogel-chitosan nano-hybrids for use as drug eluting bone replacement.

    Science.gov (United States)

    Lee, Eun-Jung; Jun, Shin-Hee; Kim, Hyoun-Ee; Kim, Hae-Won; Koh, Young-Hag; Jang, Jun-Hyeog

    2010-01-01

    Silica xerogel-chitosan hybrids containing vancomycin were fabricated by the sol-gel process at room temperature and their potential as a drug eluting bone replacement was evaluated in terms of their mechanical properties and drug release behaviors. Regardless of the content of chitosan, all of the prepared hybrids had a uniform mesoporous structure, which would allow the effectual loading of vancomycin. As the content of chitosan was increased, the strength, strain to failure, and work of fracture of the hybrids were significantly enhanced, while the elastic modulus was decreased. These changes in the mechanical properties were mainly attributed to the mitigation of the brittleness of the silica xerogel through its hybridization with the flexible chitosan phase. In addition, the initial burst-effect was remarkably reduced by increasing the content of chitosan. The hybrids with more than 30% chitosan could release the vancomycin for an extended period of time in a controlled manner.

  15. Oxide-Free Bonding of III-V-Based Material on Silicon and Nano-Structuration of the Hybrid Waveguide for Advanced Optical Functions

    Directory of Open Access Journals (Sweden)

    Konstantinos Pantzas

    2015-10-01

    Full Text Available Oxide-free bonding of III-V-based materials for integrated optics is demonstrated on both planar Silicon (Si surfaces and nanostructured ones, using Silicon on Isolator (SOI or Si substrates. The hybrid interface is characterized electrically and mechanically. A hybrid InP-on-SOI waveguide, including a bi-periodic nano structuration of the silicon guiding layer is demonstrated to provide wavelength selective transmission. Such an oxide-free interface associated with the nanostructured design of the guiding geometry has great potential for both electrical and optical operation of improved hybrid devices.

  16. Shear-bond-strength of orthodontic brackets to aged nano-hybrid composite-resin surfaces using different surface preparation.

    Science.gov (United States)

    Demirtas, Hatice Kubra; Akin, Mehmet; Ileri, Zehra; Basciftci, Faruk Ayhan

    2015-01-01

    The aim of this study was to evaluate the effects of different surface preparation methods on the shear bond strength (SBS) of orthodontic metal brackets to aged nano-hybrid resin composite surfaces in vitro. A total of 100 restorative composite resin discs, 6 mm in diameter and 3 mm thick, were obtained and treated with an ageing procedure. After ageing, the samples were randomly divided as follows according to surface preparation methods: (1)Control, (2)37% phosphoric acid gel, (3)Sandblasting, (4)Diamond bur, (5)Air-flow and 20 central incisor teeth were used for the control etched group. SBS test were applied on bonded metal brackets to all samples. SBS values and residual adhesives were evaluated. Analysis of variance showed a significant difference (phybrid composite resin surfaces.

  17. DNA Hybridization Detection Based on Resonance Frequency Readout in Graphene on Au SPR Biosensor

    Directory of Open Access Journals (Sweden)

    Md. Biplob Hossain

    2016-01-01

    Full Text Available This paper demonstrates a numerical modeling of surface plasmon resonance (SPR biosensor for detecting DNA hybridization by recording the resonance frequency characteristics (RFC. The proposed sensor is designed based on graphene material as biomolecular recognition elements (BRE and the sharp SPR curve of gold (Au. Numerical analysis shows that the variation of RFC for mismatched DNA strands is quiet negligible whereas that for complementary DNA strands is considerably countable. Here, graphene is used to perform faster immobilization between target DNA and probe DNA. The usage of graphene also changes the RFC that ensure hybridization of DNA event by utilizing its optochemical property. In addition, proposed sensor successfully distinguishes between hybridization and single-nucleotide polymorphisms (SNP by observing the variation level of RFC and maximum transmittance. Therefore, the proposed frequency readout based SPR sensor could potentially open a new window of detection for biomolecular interactions. We also highlight the advantage of using graphene sublayer by performing the sensitivity analysis. Sandwiching of each graphene sublayer enhances 95% sensitivity comparing with conventional SPR sensor.

  18. Silicene Nano-Ribbons: Strong Resistance Towards Oxidation due to sp2 Hybridization of the Si Valence Orbitals

    Science.gov (United States)

    Le Lay, Guy; de Padova, Paola; Quaresima, Claudio; Olivieri, Bruno; Perfetti, Paolo

    2011-03-01

    We have synthesized for the first time silicene, that is, a new silicon allotrope analogous to graphene recently theoretically predicted, in the form of a massively parallel array of quantized zigzag nano-ribbons with a common ``magic'' width of 1.6 nm. They display characteristic linear band dispersions similar to the Dirac cones of graphene, in correspondence with their hexagonal arrangement seen in STM imaging. Here we show, through the angle-dependence of REEL spectra taken at the Si L2 , 3 edge, the typical signatures of 2p --> π * and 2p --> σ * transitions associated with sp 2 hybridization of the Si valence orbitals. We further show through high-resolution synchrotron radiation Si 2p core-level spectroscopy measurements that the afore mentioned silicene grating is very resistant toward oxidation. Typically, the oxygen uptake starts at about 104 higher doses than on the clean Si(111)7x7 surface. Indeed, this striking behavior is directly related to the sp 2 bonding, an additional confirmation of the silicene (i.e., graphene-like) nature of the nano-ribbons.

  19. Noncommutative algebras, nano-structures, and quantum dynamics generated by resonances. III

    Science.gov (United States)

    Karasev, M.

    2006-04-01

    Quantum geometry, algebras with nonlinear commutation relations, representation theory, the coherent transform, and operator averaging are used to solve the perturbation problem for wave (quantum) systems near a resonance equilibrium point or a resonance equilibrium ray in two and three-dimensional spaces.

  20. Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmons

    Science.gov (United States)

    Liu, Peter Q.; Luxmoore, Isaac J.; Mikhailov, Sergey A.; Savostianova, Nadja A.; Valmorra, Federico; Faist, Jérôme; Nash, Geoffrey R.

    2015-11-01

    Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers capabilities of confining light in subwavelength dimensions and enhancing light-matter interactions. Recently, the technological potential of graphene-based plasmonics has been recognized as the latter features large tunability, higher field-confinement and lower loss compared with metal-based plasmonics. Here, we introduce hybrid structures comprising graphene plasmonic resonators coupled to conventional split-ring resonators, thus demonstrating a type of highly tunable metamaterial, where the interaction between the two resonances reaches the strong-coupling regime. Such hybrid metamaterials are employed as high-speed THz modulators, exhibiting ~60% transmission modulation and operating speed in excess of 40 MHz. This device concept also provides a platform for exploring cavity-enhanced light-matter interactions and optical processes in graphene plasmonic structures for applications including sensing, photo-detection and nonlinear frequency generation.

  1. Nanophotonic hybridization of narrow atomic cesium resonances and photonic stop gaps of opaline nanostructures

    CERN Document Server

    Harding, Philip J; Mosk, Allard P; Vos, Willem L

    2014-01-01

    We study a hybrid system consisting of a narrowband atomic optical resonance and the long-range periodic order of an opaline photonic nanostructure. To this end, we have infiltrated atomic cesium vapor in a thin silica opal photonic crystal. With increasing temperature, the frequencies of the opal's reflectivity peaks shift down by >20% due to chemical reduction of the silica. Simultaneously, the photonic bands and gaps shift relative to the fixed near-infrared cesium D1 transitions. As a result the narrow atomic resonances with high finesse (f/df=8E5) dramatically change shape from a usual dispersive shape at the blue edge of a stop gap, to an inverted dispersion lineshape at the red edge of a stop gap. The lineshape, amplitude, and off-resonance reflectivity are well modeled with a transfer-matrix model that includes the dispersion and absorption of Cs hyperfine transitions and the chemically-reduced opal. An ensemble of atoms in a photonic crystal is an intriguing hybrid system that features narrow defect-...

  2. Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmons.

    Science.gov (United States)

    Liu, Peter Q; Luxmoore, Isaac J; Mikhailov, Sergey A; Savostianova, Nadja A; Valmorra, Federico; Faist, Jérôme; Nash, Geoffrey R

    2015-11-20

    Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers capabilities of confining light in subwavelength dimensions and enhancing light-matter interactions. Recently, the technological potential of graphene-based plasmonics has been recognized as the latter features large tunability, higher field-confinement and lower loss compared with metal-based plasmonics. Here, we introduce hybrid structures comprising graphene plasmonic resonators coupled to conventional split-ring resonators, thus demonstrating a type of highly tunable metamaterial, where the interaction between the two resonances reaches the strong-coupling regime. Such hybrid metamaterials are employed as high-speed THz modulators, exhibiting ∼60% transmission modulation and operating speed in excess of 40 MHz. This device concept also provides a platform for exploring cavity-enhanced light-matter interactions and optical processes in graphene plasmonic structures for applications including sensing, photo-detection and nonlinear frequency generation.

  3. Degree of conversion of micro-hybrid, nano-hybrid and Ormocer composites using LED and QTH light-curing units

    Directory of Open Access Journals (Sweden)

    Seied Mostafa Fatemi

    2012-01-01

    Full Text Available Background and Aims: The aim of this study was to measure the degree of conversion (DC of three types of composite resins (micro-hybrid, nano-hybrid and Ormocer with different light curing units (LED LCU and QTH LCU in two depths.Materials and Methods: Three commercially available dental resin composites were used in this study: (Tetric Ceram, Ivoclar Vivadent, Liechtenstein-A2 shade, (Tetric Evoceram, Ivoclar Vivadent, Liechtenstein-A2 shade, (Ceram X, Dentsply, Germany-M2 shade. Specimens were divided into two groups, 5 specimens were photo-activated by QTH unit (Coltolux 75-Colten and the other five specimens were cured by LED (Demi-Kerr. Then each specimen was sectioned at the top surface and at 2-mm depth. The DC was measured by FT-IR(Bruker-tensor 27. The data were analyzed by 3-way ANOVA test.Results: There was significant difference between tested composite resins (P<0.001. The results of top surfaces were significantly different from those observed at 2-mm depth (P<0.001. The type of curing unit affected the polymerization of Ceram X resin composite.Conclusion: This study showed a significant difference in the degree of conversion in different thicknesses within three groups of resin composites.

  4. Enhancement of photo-response via surface plasmon resonance induced by Ag nano-particles embedded in ZnO

    Science.gov (United States)

    Li, Gaoming; Zhang, Jingwen; Chen, Guangde; Ye, Honggang; Duan, Xiangyang; Hou, Xun

    2016-09-01

    Surface plasmon resonance can be exploited to improve the performance of the photodetectors. However, it may cause the increase of dark current as a side effect. The enhancement of responsivity is highly dependent on the device structure involving SPR and the situations of the metal nano-particles. In this paper, we reported the responsivity enhancement of the ZnO UV detectors with SPR based on a structure in which Ag nano-particles are embedded in ZnO film, without the apparent increase of dark current. We found that the characteristic wavelength for SPR absorption is 380 nm, well predicted by Mie theory. And the spectral responsivity peak value increases from 472 mA/W to 10.522 A/W, by 22.3 times. The good matching between enhancement spectra and SPR absorption spectra confirms that the responsivity enhancement is resulted from SPR. Our results are of great importance in improving the photodetectors based on SPR effects, which may be widely used in light detection.

  5. Parametric decay instability near the upper hybrid resonance in magnetically confined fusion plasmas

    Science.gov (United States)

    Hansen, S. K.; Nielsen, S. K.; Salewski, M.; Stejner, M.; Stober, J.; the ASDEX Upgrade Team

    2017-10-01

    In this paper we investigate parametric decay of an electromagnetic pump wave into two electrostatic daughter waves, particularly an X-mode pump wave decaying into a warm upper hybrid wave (a limit of an electron Bernstein wave) and a warm lower hybrid wave. We describe the general theory of the above parametric decay instability (PDI), unifying earlier treatments, and show that it may occur in underdense and weakly overdense plasmas. The PDI theory is used to explain anomalous sidebands observed in collective Thomson scattering (CTS) spectra at the ASDEX Upgrade tokamak. The theory may also account for similar observations during CTS experiments in stellarators, as well as in some 1st harmonic electron cyclotron resonance and O-X-B heating experiments.

  6. Photoinduced electron transfer pathways in hydrogen-evolving reduced graphene oxide-boosted hybrid nano-bio catalyst.

    Science.gov (United States)

    Wang, Peng; Dimitrijevic, Nada M; Chang, Angela Y; Schaller, Richard D; Liu, Yuzi; Rajh, Tijana; Rozhkova, Elena A

    2014-08-26

    Photocatalytic production of clean hydrogen fuels using water and sunlight has attracted remarkable attention due to the increasing global energy demand. Natural and synthetic dyes can be utilized to sensitize semiconductors for solar energy transformation using visible light. In this study, reduced graphene oxide (rGO) and a membrane protein bacteriorhodopsin (bR) were employed as building modules to harness visible light by a Pt/TiO2 nanocatalyst. Introduction of the rGO boosts the nano-bio catalyst performance that results in hydrogen production rates of approximately 11.24 mmol of H2 (μmol protein)(-1) h(-1). Photoelectrochemical measurements show a 9-fold increase in photocurrent density when TiO2 electrodes were modified with rGO and bR. Electron paramagnetic resonance and transient absorption spectroscopy demonstrate an interfacial charge transfer from the photoexcited rGO to the semiconductor under visible light.

  7. Resonant Optical Gradient Force Interaction for Nano-Imaging and-Spectroscopy

    Science.gov (United States)

    2016-07-19

    perspective for further resonant enhancement and control of optical forces. 1. Introduction The combination of scanning probemicroscopywith optics... relatively small force variation between 23 fN to 25 fN across the resonance is due to the large broadband offset as a result of  1 2, which is a...ismuchweaker than the case of R6Gbut exhibits a larger relative spectral variation across the resonance from0.2 fN to 1 fN (for z= 2 nm). Irrespective

  8. Optimization of negative ion current in a compact microwave driven upper hybrid resonance multicusp plasma source.

    Science.gov (United States)

    Sahu, D; Bhattacharjee, S; Singh, M J; Bandyopadhyay, M; Chakraborty, A

    2012-02-01

    Performance of a microwave driven upper hybrid resonance multicusp plasma source as a volume negative ion source is reported. Microwaves are directly launched into the plasma chamber predominantly in the TE(11) mode. The source is operated at different discharge conditions to obtain the optimized negative H(-) ion current which is ∼33 μA (0.26 mA∕cm(2)). Particle balance equations are solved to estimate the negative ion density, which is compared with the experimental results. Future prospects of the source are discussed.

  9. Optimization of negative ion current in a compact microwave driven upper hybrid resonance multicusp plasma sourcea)

    Science.gov (United States)

    Sahu, D.; Bhattacharjee, S.; Singh, M. J.; Bandyopadhyay, M.; Chakraborty, A.

    2012-02-01

    Performance of a microwave driven upper hybrid resonance multicusp plasma source as a volume negative ion source is reported. Microwaves are directly launched into the plasma chamber predominantly in the TE11 mode. The source is operated at different discharge conditions to obtain the optimized negative H- ion current which is ˜33 μA (0.26 mA/cm2). Particle balance equations are solved to estimate the negative ion density, which is compared with the experimental results. Future prospects of the source are discussed.

  10. Multiway study of hybridization in nanoscale semiconductor labeled DNA based on fluorescence resonance energy transfer

    DEFF Research Database (Denmark)

    Gholami, Somayeh; Kompany Zare, Mohsen

    2013-01-01

    The resolution of the ternary-binary complex competition of a target sequence and of its two complementary probes in sandwich DNA hybridization is reported. To achieve this goal, Fluorescence Resonance Energy Transfer (FRET) between oligonucleotide-functionalized quantum dot (QD) nanoprobes (QD...... in the photoluminescence excitation (PLE) plot. From the obtained data, energy transfer efficiency and Forster radius (R-0) were calculated. In particular, our results demonstrated that energy transfer by using QD donor-QD acceptor FRET pairs is more efficient in comparison with QD donor-organic dye acceptor pairs. Soft...

  11. Properties of the ion-ion hybrid resonator in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Morales, George J. [Univ. of California, Los Angeles, CA (United States)

    2015-10-06

    The project developed theoretical and numerical descriptions of the properties of ion-ion hybrid Alfvén resonators that are expected to arise in the operation of a fusion reactor. The methodology and theoretical concepts were successfully compared to observations made in basic experiments in the LAPD device at UCLA. An assessment was made of the excitation of resonator modes by energetic alpha particles for burning plasma conditions expected in the ITER device. The broader impacts included the generation of basic insight useful to magnetic fusion and space science researchers, defining new avenues for exploration in basic laboratory experiments, establishing broader contacts between experimentalists and theoreticians, completion of a Ph.D. dissertation, and promotion of interest in science through community outreach events and classroom instruction.

  12. General and hybrid correlation nuclear magnetic resonance analysis of phosphorus in Phytophthora palmivora.

    Science.gov (United States)

    Kirwan, Gemma M; Fernandez, David I; Niere, Julie O; Adams, Michael J

    2012-10-01

    Generalized two-dimensional (Gen2D) correlation analysis and hybrid correlation analysis have been applied to a series of dynamic (31)P nuclear magnetic resonance (NMR) spectra to monitor the in vivo metabolic changes of the plant pathogen Phytophthora palmivora in the presence and absence of phosphonate over an 18-h period. Results indicate that phosphonate exposure causes cleavage in organism polyphosphate chains as well as an increase in total sugar phosphates. In the presence of phosphonate, the NMR resonances attributed to terminal polyphosphate phosphorus reduced at a lower rate than those of middle polyphosphate phosphorus, indicating a change in average chain length and suggesting cleavage in the middle of the chain as well as at the ends. The correlation analysis techniques serve to identify and confirm spectral regions undergoing major change in the time-series data and facilitate the analysis of these dynamic changes.

  13. Carbon nanotubes randomly decorated with gold clusters: from nano{sup 2}hybrid atomic structures to gas sensing prototypes

    Energy Technology Data Exchange (ETDEWEB)

    Charlier, J-C; Zanolli, Z [Unite de Physico-Chimie et de Physique des Materiaux (PCPM), European Theoretical Spectroscopy Facility (ETSF), Universite Catholique de Louvain, Place Croix du Sud 1, B-1348 Louvain-la-Neuve (Belgium); Arnaud, L; Avilov, I V; Felten, A; Pireaux, J-J [Centre de Recherche en Physique de la Matiere et du Rayonnement (PMR-LISE), Facultes Universitaires Notre-Dame de la Paix, 61 Rue de Bruxelles, B-5000 Namur (Belgium); Delgado, M [Sensotran, s.l., Avenida Remolar 31, E-08820 El Prat de Llobregat, Barcelona (Spain); Demoisson, F; Reniers, F [Service de Chimie Analytique et Chimie des Interfaces (CHANI), Universite Libre de Bruxelles, Faculte des Sciences, CP255, Boulevard du Triomphe 2, B-1050 Bruxelles (Belgium); Espinosa, E H; Ionescu, R; Leghrib, R; Llobet, E [Department of Electronic Engineering, Universitat Rovira i Virgili, Avenida Paisos Catalans 26, E-43007 Tarragona (Spain); Ewels, C P; Suarez-Martinez, I [Institut des Materiaux Jean Rouxel (IMN), Universite de Nantes, 2 rue de la Houssiniere-BP 32229, F-44322 Nantes Cedex 3 (France); Guillot, J; Mansour, A; Migeon, H-N [Departement Science et Analyse des Materiaux, Centre de Recherche Public-Gabriel Lippmann, rue du Brill 41, L-4422 Belvaux (Luxembourg); Watson, G E, E-mail: jean-jacques.pireaux@fundp.ac.b [Vega Science Trust, Unit 118, Science Park SQ, Brighton, BN1 9SB (United Kingdom)

    2009-09-16

    Carbon nanotube surfaces, activated and randomly decorated with metal nanoclusters, have been studied in uniquely combined theoretical and experimental approaches as prototypes for molecular recognition. The key concept is to shape metallic clusters that donate or accept a fractional charge upon adsorption of a target molecule, and modify the electron transport in the nanotube. The present work focuses on a simple system, carbon nanotubes with gold clusters. The nature of the gold-nanotube interaction is studied using first-principles techniques. The numerical simulations predict the binding and diffusion energies of gold atoms at the tube surface, including realistic atomic models for defects potentially present at the nanotube surface. The atomic structure of the gold nanoclusters and their effect on the intrinsic electronic quantum transport properties of the nanotube are also predicted. Experimentally, multi-wall CNTs are decorated with gold clusters using (1) vacuum evaporation, after activation with an RF oxygen plasma and (2) colloid solution injected into an RF atmospheric plasma; the hybrid systems are accurately characterized using XPS and TEM techniques. The response of gas sensors based on these nano{sup 2}hybrids is quantified for the detection of toxic species like NO{sub 2}, CO, C{sub 2}H{sub 5}OH and C{sub 2}H{sub 4}.

  14. Lower hybrid wave resonance cone detection via CO/sub 2/ laser scattering

    Energy Technology Data Exchange (ETDEWEB)

    Wurden, G.A.; Wong, K.L.; Ono, M.

    1984-04-01

    Lower hybrid waves are studied in the Princeton ACT-I steady-state toroidal plasma device using a radially scanning CO/sub 2/ laser scattering system with both amplitude and phase sensitive detection techniques. Clearly defined resonance cones launched from external electrostatic antennas are seen to disappear as the plasma density is raised. Scaling of LHW laser signal with RF power in the presence of resonance cones shows nonlinearities associated with RF induced changes in the effective laser scattering volume. Absolute fluctuation level estimates suggest this occurs when e PHI/T/sub e/ greater than or equal to 1. Wavefront curvature effects can cause a complete loss of resonance cone laser signals, even though probes indicate that cones are still present. Measurements of the wave k/sub perpendicular/-spectrum in the plasma show direct evidence for electron Landau filtering of the original wave k/sub parallel/-spectrum launched from the antenna at the plasma edge, and strong dependence on antenna phasing. Finally, frequency shifts and loss of the resonance cone signal are associated with high levels of plasma density edge turbulence.

  15. Resonance hybridization and near field properties of strongly coupled plasmonic ring dimer-rod nanosystem

    Energy Technology Data Exchange (ETDEWEB)

    Koya, Alemayehu Nana; Ji, Boyu; Hao, Zuoqiang; Lin, Jingquan, E-mail: linjingquan@cust.edu.cn [School of Science, Changchun University of Science and Technology, Changchun 130022 (China)

    2015-09-21

    Combined effects of polarization, split gap, and rod width on the resonance hybridization and near field properties of strongly coupled gold dimer-rod nanosystem are comparatively investigated in the light of the constituent nanostructures. By aligning polarization of the incident light parallel to the long axis of the nanorod, introducing small split gaps to the dimer walls, and varying width of the nanorod, we have simultaneously achieved resonance mode coupling, huge near field enhancement, and prolonged plasmon lifetime. As a result of strong coupling between the nanostructures and due to an intense confinement of near fields at the split and dimer-rod gaps, the extinction spectrum of the coupled nanosystem shows an increase in intensity and blueshift in wavelength. Consequently, the near field lifespan of the split-nanosystem is prolonged in contrast to the constituent nanostructures and unsplit-nanosystem. On the other hand, for polarization of the light perpendicular to the long axis of the nanorod, the effect of split gap on the optical responses of the coupled nanosystem is found to be insignificant compared to the parallel polarization. These findings and such geometries suggest that coupling an array of metallic split-ring dimer with long nanorod can resolve the huge radiative loss problem of plasmonic waveguide. In addition, the Fano-like resonances and immense near field enhancements at the split and dimer-rod gaps imply the potentials of the nanosystem for practical applications in localized surface plasmon resonance spectroscopy and sensing.

  16. Towards strong light-matter coupling at the single-resonator level with sub-wavelength mid-infrared nano-antennas

    Science.gov (United States)

    Malerba, M.; Ongarello, T.; Paulillo, B.; Manceau, J.-M.; Beaudoin, G.; Sagnes, I.; De Angelis, F.; Colombelli, R.

    2016-07-01

    We report a crucial step towards single-object cavity electrodynamics in the mid-infrared spectral range using resonators that borrow functionalities from antennas. Room-temperature strong light-matter coupling is demonstrated in the mid-infrared between an intersubband transition and an extremely reduced number of sub-wavelength resonators. By exploiting 3D plasmonic nano-antennas featuring an out-of-plane geometry, we observed strong light-matter coupling in a very low number of resonators: only 16, more than 100 times better than what reported to date in this spectral range. The modal volume addressed by each nano-antenna is sub-wavelength-sized and it encompasses only ≈4400 electrons.

  17. Towards strong light-matter coupling at the single-resonator level with sub-wavelength mid-infrared nano-antennas

    Energy Technology Data Exchange (ETDEWEB)

    Malerba, M.; De Angelis, F., E-mail: francesco.deangelis@iit.it [Istituto Italiano di Tecnologia, Via Morego, 30, I-16163 Genova (Italy); Ongarello, T.; Paulillo, B.; Manceau, J.-M.; Beaudoin, G.; Sagnes, I.; Colombelli, R., E-mail: raffaele.colombelli@u-psud.fr [Centre for Nanoscience and Nanotechnology (C2N Orsay), CNRS UMR9001, Univ. Paris Sud, Univ. Paris Saclay, 91405 Orsay (France)

    2016-07-11

    We report a crucial step towards single-object cavity electrodynamics in the mid-infrared spectral range using resonators that borrow functionalities from antennas. Room-temperature strong light-matter coupling is demonstrated in the mid-infrared between an intersubband transition and an extremely reduced number of sub-wavelength resonators. By exploiting 3D plasmonic nano-antennas featuring an out-of-plane geometry, we observed strong light-matter coupling in a very low number of resonators: only 16, more than 100 times better than what reported to date in this spectral range. The modal volume addressed by each nano-antenna is sub-wavelength-sized and it encompasses only ≈4400 electrons.

  18. Evaluation of structural and mechanical properties of electrospun nano-micro hybrid of poly hydroxybutyrate-chitosan/silk scaffold for cartilage tissue engineering.

    Science.gov (United States)

    Karbasi, Saeed; Fekrat, Farnoosh; Semnani, Daryoush; Razavi, Shahnaz; Zargar, Elham Naghash

    2016-01-01

    One of the new methods of scaffold fabrication is a nano-micro hybrid structure in which the properties of the scaffold are improved by introducing nanometer and micrometer structures. This method could be suitable for scaffold designing if some features improve. In this study, electrospun nanofibers of 9% weight solution of poly (3-hydroxybutyrate) (P3HB) and a 15% weight of chitosan by trifluoroacetic acid were coated on both the surface of a silk knitted substrate in the optimum condition to improve the mechanical properties of scaffolds for cartilage tissue engineering application. These hybrid nano-micro fibrous scaffolds were characterized by structural and mechanical evaluation methods. Scanning electron microscopy values and porosity analysis showed that average diameter of nanofibers was 584.94 nm in electrospinning part and general porosity was more than 80%. Fourier transform infrared spectroscopy results indicated the presence of all elements without pollution. The tensile test also stated that by electrospinning, as well as adding chitosan, both maximum strength and maximum elongation increased to 187 N and 10 mm. It means that the microfibrous part of scaffold could affect mechanical properties of nano part of the hybrid scaffold, significantly. It could be concluded that P3HB-chitosan/silk hybrid scaffolds can be a good candidate for cartilage tissue engineering.

  19. Properties of Organic-Inorganic Nano-SiO2/Dicyclopentandiene Cyanate Ester Resin Hybrid Materials%有机-无机Nano-SiO2/DCPDCE杂化材料的性能

    Institute of Scientific and Technical Information of China (English)

    贾园; 颜红侠; 唐玉生; 马雷

    2012-01-01

    To resolve the problem of ordinary nano-SiO2 easy-agglomeration in the dicyclopentandiene cyanate es-ter(DCPDCE) resin system, DCPDCE, was modified utilizing organic-inorganic nano-SiO2 prepared by sol-gel process. This article discussed the properties of organic-inorganic nano-SiO2/DCPDCE,such as dielectric properties and mechanical properties. The result showed that, compared with ordinary SiO2, organic-inorganic SiO2 can be well-dispersed in DCPDCE. When the content of organic-inorganic nano-SiO2 is 3. 0wt% , the total properties of hybrid materials is the best.%为解决传统商用nano-SiO2粒子在双环戊二烯型氰酸酯(DCPDCE)树脂基体中容易团聚的问题,利用Sol-Gel法制备的有机-无机nano-SiO2为填料对DCPDCED进行改性.研究了有机-无机nano-SiO2含量对nano-SiO2/DCPDCE杂化材料力学性能、介电常数、介电损耗因子的影响.结果表明:有机-无机nano-SiO2较商用nano-SiO2在DCPDCE中分散更优;当有机-无机纳米SiO2含量为3.0wt%时,杂化材料的综合性能最优.

  20. Resonant photothermal laser processing of hybrid gold/titania nanoparticle films

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Lina; Franzka, Steffen; Dzialkowski, Kevin [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Hardt, Sebastian; Wiggers, Hartmut [Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Institut für Verbrennung und Gasdynamik, Universität Duisburg-Essen, 47048 Duisburg (Germany); Reichenberger, Sven [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Institut für Lacke und Oberflächenchemie, Hochschule Niederrhein, 47798 Krefeld (Germany); Wagener, Philipp [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Hartmann, Nils, E-mail: nils.hartmann@uni-due.de [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany)

    2015-05-01

    Graphical abstract: - Highlights: • Photothermal processing of TiO{sub 2} and hybrid Au/TiO{sub 2} nanoparticles using continuous-wave lasers is demonstrated. • Processing of TiO{sub 2} nanoparticles at 355 nm results in a transition from anatase to rutile. • Decoration of TiO{sub 2} nanoparticles with Au nanoparticles results in an increased absorbance in the visible range. • Hybrid Au/TiO{sub 2} nanoparticles can be processed at 355 nm and 532 nm in a large laser parameter window. • Processing of hybrid Au/TiO{sub 2} nanoparticles at 532 nm can be carried out at low laser powers and short laser pulse lengths. - Abstract: Photothermal processing of thin anatase TiO{sub 2} and hybrid Au/anatase TiO{sub 2} nanoparticle films on glass supports is investigated using continuous-wave microfocused lasers at λ = 355 nm and λ = 532 nm. UV/Vis spectroscopy, Raman spectroscopy, optical microscopy, atomic force microscopy and scanning electron microscopy are used for characterization. Processing of TiO{sub 2} nanoparticle films is feasible at λ = 355 nm only. In contrast, the addition of Au nanoparticles enhances the overall absorbance of the material in the visible range and enables processing at both wavelengths, i.e. at λ = 355 nm and λ = 532 nm. Generally, laser heating induces a transition from anatase to rutile. The modification degree increases with increasing laser power and laser irradiation time. Resonant laser processing of hybrid Au/TiO{sub 2}-mesoporous films provide promising perspectives in various applications, e.g. in photovoltaics, where embedded nanoparticulate Au could be exploited to enhance light trapping.

  1. Organic/Inorganic Nano-hybrids with High Dielectric Constant for Organic Thin Film Transistor Applications

    Science.gov (United States)

    Yu, Yang-Yen; Jiang, Ai-Hua; Lee, Wen-Ya

    2016-11-01

    The organic material soluble polyimide (PI) and organic-inorganic hybrid PI-barium titanate (BaTiO3) nanoparticle dielectric materials (IBX, where X is the concentration of BaTiO3 nanoparticles in a PI matrix) were successfully synthesized through a sol-gel process. The effects of various BaTiO3 contents on the hybrid film performance and performance optimization were investigated. Furthermore, pentacene-based organic thin film transistors (OTFTs) with PI-BaTiO3/polymethylmethacrylate or cyclic olefin copolymer (COC)-modified gate dielectrics were fabricated and examined. The hybrid materials showed effective dispersion of BaTiO3 nanoparticles in the PI matrix and favorable thermal properties. X-ray diffraction patterns revealed that the BaTiO3 nanoparticles had a perovskite structure. The hybrid films exhibited high formability and planarity. The IBX hybrid dielectric films exhibited tunable insulating properties such as the dielectric constant value and capacitance in ranges of 4.0-8.6 and 9.2-17.5 nF cm-2, respectively. Adding the modified layer caused the decrease of dielectric constant values and capacitances. The modified dielectric layer without cross-linking displayed a hydrophobic surface. The electrical characteristics of the pentacene-based OTFTs were enhanced after the surface modification. The optimal condition for the dielectric layer was 10 wt% hybrid film with the COC-modified layer; moreover, the device exhibited a threshold voltage of 0.12 V, field-effect mobility of 4.32 × 10-1 cm2 V-1 s-1, and on/off current of 8.4 × 107.

  2. Self-assembled hybrid materials based on conjugated polymers and semiconductors nano-crystals for plastic solar cells; Architectures hybrides auto-assemblees a base de systemes polyconjugues et de nanocristaux de semi-conducteurs pour le photovoltaique plastique

    Energy Technology Data Exchange (ETDEWEB)

    Girolamo, J. de

    2007-11-15

    This work is devoted to the elaboration of self-assembled hybrid materials based on poly(3- hexyl-thiophene) and CdSe nano-crystals for photovoltaic applications. For that, complementary molecular recognition units were introduced as side chain groups on the polymer and at the nano-crystals' surface. Diamino-pyrimidine groups were introduced by post-functionalization of a precursor copolymer, namely poly(3-hexyl-thiophene-co-3- bromo-hexyl-thiophene) whereas thymine groups were introduced at the nano-crystals' surface by a ligand exchange reaction with 1-(6-mercapto-hexyl)thymine. However, due to their different solubility, the mixing of the two components by solution processes is difficult. A 'one-pot' procedure was developed, but this method led to insoluble aggregates without control of the hybrid composition. To overcome the solubility problem, the layer-by-layer method was used to prepare the films. This method allows a precise control of the deposition process. Experimental parameters were tested in order to evaluate their impact on the resulting film. The films morphology was investigated by microscopy and X-Ray diffraction techniques. These analyses reveal an interpenetrated structure of nano-crystals within the polymer matrix rather than a multilayered structure. Electrochemical and spectro electrochemical studies were performed on the hybrid material deposited by the LBL process. Finally the materials were tested in a solar cell configuration and the I=f(V) curves reveals a clear photovoltaic behaviour. (author)

  3. Refractive index sensing characteristics of dual resonances in rectangular fractal nano-apertures

    Science.gov (United States)

    Aslan, Ekin; Turkmen, Mustafa

    2015-08-01

    Aperture based sensing platforms can be useful for both gas and bio-sensing applications. In this study, we investigate the refractive index sensing characteristics of dual resonances in rectangular fractal nanoapertures. By taking the advantages coming from its aperture based nature and dual band resonant behavior, one can use this platform to detect two different chemical/bio-molecules simultaneously. For the numerical analysis, we study the rectangular fractal nanoantenna array through the finite difference time domain (FDTD) method. We also introduce a fine tuning mechanism for adjusting the resonance frequencies which is important for the sensing applications. Then, we demonstrate the results of refractive index sensitivity tests in order to show the behavior of the structure against the refractive index changes. In these tests, we embed our sensing platform into different cladding media and obtain the refractive index sensing characteristics of dual resonances. Due to the dual-resonant behavior with easily accessible ultra-high-field localization characteristics, the proposed sensing platform can be a good candidate for ultra-sensitive chemical- and bio-sensing applications.

  4. Double-Slot Hybrid Plasmonic Ring Resonator Used for Optical Sensors and Modulators

    Directory of Open Access Journals (Sweden)

    Xu Sun

    2015-11-01

    Full Text Available An ultra-high sensitivity double-slot hybrid plasmonic (DSHP ring resonator, used for optical sensors and modulators, is developed. Due to high index contrast, as well as plasmonic enhancement, a considerable part of the optical energy is concentrated in the narrow slots between Si and plasmonic materials (silver is used in this paper, which leads to high sensitivity to the infiltrating materials. By partial opening of the outer plasmonic circular sheet of the DSHP ring, a conventional side-coupled silicon on insulator (SOI bus waveguide can be used. Experimental results demonstrate ultra-high sensitivity (687.5 nm/RIU of the developed DSHP ring resonator, which is about five-times higher than for the conventional Si ring with the same geometry. Further discussions show that a very low detection limit (5.37 × 10−6 RIU can be achieved after loaded Q factor modifications. In addition, the plasmonic metal structures offer also the way to process optical and electronic signals along the same hybrid plasmonic circuits with small capacitance (~0.275 fF and large electric field, which leads to possible applications in compact high-efficiency electro-optic modulators, where no extra electrodes for electronic signals are required.

  5. Stochastic resonance enhancement of small-world neural networks by hybrid synapses and time delay

    Science.gov (United States)

    Yu, Haitao; Guo, Xinmeng; Wang, Jiang

    2017-01-01

    The synergistic effect of hybrid electrical-chemical synapses and information transmission delay on the stochastic response behavior in small-world neuronal networks is investigated. Numerical results show that, the stochastic response behavior can be regulated by moderate noise intensity to track the rhythm of subthreshold pacemaker, indicating the occurrence of stochastic resonance (SR) in the considered neural system. Inheriting the characteristics of two types of synapses-electrical and chemical ones, neural networks with hybrid electrical-chemical synapses are of great improvement in neuron communication. Particularly, chemical synapses are conducive to increase the network detectability by lowering the resonance noise intensity, while the information is better transmitted through the networks via electrical coupling. Moreover, time delay is able to enhance or destroy the periodic stochastic response behavior intermittently. In the time-delayed small-world neuronal networks, the introduction of electrical synapses can significantly improve the signal detection capability by widening the range of optimal noise intensity for the subthreshold signal, and the efficiency of SR is largely amplified in the case of pure chemical couplings. In addition, the stochastic response behavior is also profoundly influenced by the network topology. Increasing the rewiring probability in pure chemically coupled networks can always enhance the effect of SR, which is slightly influenced by information transmission delay. On the other hand, the capacity of information communication is robust to the network topology within the time-delayed neuronal systems including electrical couplings.

  6. Far-Field Plasmonic Resonance Enhanced Nano-Particle Image Velocimetry within a Micro Channel

    CERN Document Server

    Zhang, Zhili; Haque, Sara S; Zhang, Mingjun

    2010-01-01

    In this paper, a novel far-field plasmonic resonance enhanced nanoparticle-seeded Particle Image Velocimetry (nPIV) has been demonstrated to measure the velocity profile in a micro channel. Chemically synthesized silver nanoparticles have been used to seed the flow in the micro channel. By using Discrete Dipole Approximation (DDA), plasmonic resonance enhanced light scattering has been calculated for spherical silver nanoparticles with diameters ranging from 15nm to 200nm. Optimum scattering wavelength is specified for the nanoparticles in two media: water and air. The diffraction-limited plasmonic resonance enhanced images of silver nanoparticles at different diameters have been recorded and analyzed. By using standard PIV techniques, the velocity profile within the micro channel has been determined from the images.

  7. New polyoxometalates containing hybrid polymers and their potential for nano-patterning.

    Science.gov (United States)

    Kalyani, Vishwanath; Satyanarayana, V S V; Singh, Vikram; Pradeep, Chullikkattil P; Ghosh, Subrata; Sharma, Satinder K; Gonsalves, Kenneth E

    2015-01-26

    Two new polyoxometalate (POM)-based hybrid monomers (Bu4 N)5 (H)[P2 V3 W15 O59 {(OCH2 )3 CNHCO(CH3 )CCH2 }] (2) and (S(CH3 )2 C6 H4 OCOC(CH3 )=CH2 )6 [PV  2Mo10 O40 ] (5) were developed by grafting polymerizable organic units covalently or electrostatically onto Wells-Dawson and Keggin-type clusters and were characterized by analytical and spectroscopic techniques including ESI-MS and/or single-crystal X-ray diffraction analyses. Radical initiated polymerization of 2 and 5 with organic monomers (methacryloyloxy)phenyldimethylsulfonium triflate (MAPDST) and/or methylmethacrylate (MMA) yielded a new series of POM/polymer hybrids that were characterized by (1) H, (31) P NMR and IR spectroscopic techniques, gel-permeation chromatography as well as thermal analyses. Preliminary tests were conducted on these POM/polymer hybrids to evaluate their properties as photoresists using electron beam (E-beam)/extreme ultraviolet (EUV) lithographic techniques. It was observed that the POM/polymer hybrid of 2 with MAPDST exhibited improved sensitivity under EUV lithographic conditions in comparison to the MAPDST homopolymer resist possibly due to the efficient photon harvesting by the POM clusters from the EUV source.

  8. Sol-gel-derived silicate nano-hybrids for biomedical applications.

    Science.gov (United States)

    Tsuru, Kanji; Shirosaki, Yuki; Hayakawa, Satoshi; Osaka, Akiyoshi

    2013-01-01

    Organic-inorganic hybrids of poly(dimethyl siloxane), gelatin, and chitosan with such silanes as tetraethoxysilane and 3-glycidoxytriethoxysilane are derived via the sol-gel routes. Their biomedical applications are discussed from biomimetic deposition of bone-like apatite, cell culture, and in vivo behavior.

  9. Electron fluctuation induced resonance broadening in nano electromechanical systems: the origin of shear force in vacuum.

    Science.gov (United States)

    Siria, A; Barois, T; Vilella, K; Perisanu, S; Ayari, A; Guillot, D; Purcell, S T; Poncharal, P

    2012-07-11

    This article presents a study of the poorly understood "shear-force" used in an important class of near-field instruments that use mechanical resonance feedback detection. In the case of a metallic probe near a metallic surface in vacuum, we show that in the 10-60 nm range there is no such a thing as a shear-force in the sense of the nonconservative friction force. Fluctuations of the oscillator resonance frequency, likely induced by local charge variations, could account for the reported effects in the literature without introducing a dissipative force.

  10. A Novel Ion-exchange Method for the Synthesis of Nano-SnO/micro-C Hybrid Structure as High Capacity Anode Material in Lithium Ion Batteries

    Institute of Scientific and Technical Information of China (English)

    Zhi Tan; Zhenhua Sun; Qi Guo; Haihua Wang; Dangsheng Su

    2013-01-01

    A novel and simple ion-exchange method was developed for the synthesis of nano-SnO/micro-C hybrid structure.The structure of the as prepared nano-SnO/micro-C was directly revealed by scanning electron microscopy (SEM)and transmission electron microscopy (TEM).SnO particles with the size about 25 nm were well confined in amorphous carbon microparticles.Carbon matrix in micrometer scale not only acts as a protective buffer for the SnO nanoparticles during the battery cycling processes,but also avoids the shortcomings of nanostructures,such as low tap density and potential safety threats.Electrochemical behaviors of the nano-SnO/micro-C were tested as anode material in lithium ion batteries.The initial reversible capacity is 508 mA h g-1,and the reversible capacity after 60 cycles is 511 mA h g-1,indicating good capacity retention ability.

  11. Fano resonance and hybridization gap in the Kondo lattice URu2Si2^*

    Science.gov (United States)

    Park, Wan Kyu; Tobash, P. H.; Ronning, F.; Bauer, E. D.; Sarrao, J. L.; Thompson, J. D.; Greene, L. H.

    2012-02-01

    The nature of the `hidden' order transition in URu2Si2 remains puzzling despite intensive research over the past two and half decades. A key question under debate is whether a hybridization gap between the renormalized bands can be identified as the long-sought hidden order parameter. We report on the measurement of a hybridization gap in URu2Si2 employing a spectroscopic technique based on quasiparticle scattering across a ballistic metallic junction [1]. The differential conductance data exhibit an asymmetric double-peak structure, a signature for a Fano resonance in a Kondo lattice [2]. The extracted hybridization gap opens well above the hidden order transition temperature, indicating that it is not the order parameter for the hidden order phase. Our results place constraints on the origin of the hidden order transition in URu2Si2.[4pt] [1] W. K. Park et al., arXiv:1110.5541.[0pt] [2] M. Maltseva, M. Dzero, P. Coleman, PRL 103, 206402 (2009).

  12. Real time hybridization studies by resonant waveguide gratings using nanopattern imaging for Single Nucleotide Polymorphism detection

    KAUST Repository

    Bougot-Robin, Kristelle

    2013-12-20

    2D imaging of biochips is particularly interesting for multiplex biosensing. Resonant properties allow label-free detection using the change of refractive index at the chip surface. We demonstrate a new principle of Scanning Of Resonance on Chip by Imaging (SORCI) based on spatial profiles of nanopatterns of resonant waveguide gratings (RWGs) and its embodiment in a fluidic chip for real-time biological studies. This scheme allows multiplexing of the resonance itself by providing nanopattern sensing areas in a bioarray format. Through several chip designs we discuss resonance spatial profiles, dispersion and electric field distribution for optimal light-matter interaction with biological species of different sizes. Fluidic integration is carried out with a black anodized aluminum chamber, advantageous in term of mechanical stability, multiple uses of the chip, temperature control and low optical background. Real-time hybridization experiments are illustrated by SNP (Single Nucleotide Polymorphism) detection in gyrase A of E. coli K12, observed in evolution studies of resistance to the antibiotic ciprofloxacin. We choose a 100 base pairs (bp) DNA target (∼30 kDa) including the codon of interest and demonstrate the high specificity of our technique for probes and targets with close affinity constants. This work validates the safe applicability of our unique combination of RWGs and simple instrumentation for real-time biosensing with sensitivity in buffer solution of ∼10 pg/mm2. Paralleling the success of RWGs sensing for cells sensing, our work opens new avenues for a large number of biological studies. © 2013 Springer Science+Business Media.

  13. Hybrid membrane resonators for multiple frequency asymmetric absorption and reflection in large waveguide

    CERN Document Server

    Fu, Caixing; Yang, Min; Xiao, Songwen; Yang, Z

    2016-01-01

    We report that Hybrid membrane resonators (HMRs) made of a decorated membrane resonator backed by a shallow cavity can function as Helmholtz resonators (HRs) when mounted on the sidewall of a clear waveguide for air ventilation. When two single-frequency HMRs are used in the same scheme as two frequency-detuned HRs, asymmetric total absorption/reflection is demonstrated at 286.7 Hz with absorption coefficient over 97 % in a waveguide 9 cm x 9 cm in cross section. When two multiple-frequency HMRs are used, absorption in the range of near 60 % to above 80 % is observed at 403 Hz, 450 Hz, 688 Hz, 863 Hz and 945 Hz. Theoretical predictions agree well with the experimental data. The HMRs may replace HRs in duct noise reduction applications in that at a single operation frequency they have stronger strength to cover a much larger cross section area than that of HRs with similar cavity volume, and they can be designed to provide multiple frequency absorption band.

  14. Gamma-Irradiation modified polypropylene and nano silver hybrid films: antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Oliani, Washigton L.; Alcantara, Mara T.S.; Lima, Luis F.C.P. de; Bueno, Nelson R.; Rogero, Sizue O.; Lugao, Ademar B.; Parra, Duclerc F., E-mail: washoliani@usp.br [Instituto de Pesquisas Energeticas Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil); Huenuman, Nilton E.L.; Santos, Priscila M. dos [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Dept. of Microbiologia; Riella, Humberto G. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2013-07-01

    This paper presents a study of films based on blends of polypropylene (PP) with radiation modified PP and insertion of silver nanoparticles aiming bactericide effect. The use of silver (Ag) gives important antibacterial properties since silver is highly toxic for bacteria. The blend of 50/50 PP and gamma irradiated PP was processed in a twin screw extruder. The polypropylene was processed for five PP-Nanocomposite AgNPs in different concentrations of 0.25%; 0.5%; 1.0%; 2.0% and 4.0% in wt%. The material was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), cytotoxicity assay and reduction colony-forming unit (CFU). The analyzed films showed agglomeration of silver particles and regions with homogeneous distribution of the particles. The interactions of the nano silver bactericidal effect with E. coli and S. aureus were assessed. (author)

  15. Polythiophene encapsulated inside (13, 0) CNT: A nano-hybrid system

    Science.gov (United States)

    Tayebeh, Movlarooy

    2014-06-01

    We present a first-principles calculation on the electronic and optical properties of a hybrid nanotube system consisting of a (13, 0) single-walled carbon nanotube encapsulated by polythiophene. This hybrid-system represents a complete new type of matter and is known as the peapod system. We analyze how the polythiophene changes the electronic and optical properties of the nanotube. In particular, we examine new features in the dielectric function due to the transitions between the states of the polymer and the nanotube. The electronic structure of the combined system appears to be a simple superposition of the individual constituents. The density functional theory calculations demonstrate van der Waals interaction as the bonding mechanism between the tube and the encapsulated molecule.

  16. Adsorption of Cd(II), Cu(II) and Ni(II) ions by cross-linking chitosan/rectorite nano-hybrid composite microspheres.

    Science.gov (United States)

    Zeng, Lixuan; Chen, Yufei; Zhang, Qiuyun; Guo, Xingmei; Peng, Yanni; Xiao, Huijuan; Chen, Xiaocheng; Luo, Jiwen

    2015-10-05

    Chitosan/rectorie (CTS/REC) nano-hybrid composite microsphere was prepared by changing the proportion of CTS/REC with 2:1, 3:1 and 4:1. Compared with the pure cross-linking chitosan microsphere, the nano-hybrid composite microsphere was proved to have better sorption capacity of Cd(II), Cu(II) and Ni(II), especially 2:1(CTS/REC-1). The adsorption behavior of the microsphere of Cd(II), Cu(II) and Ni(II) was investigated in single and binary metal systems. In single system, the equilibrium studies showed that the adsorption of Cd(II), Cu(II) and Ni(II) followed the Langmuir model and the pseudo-second-order kinetic model. The negative values of (ΔG) suggested that the adsorption process was spontaneous. In binary system, the combined action of the metals was found to be antagonistic and the metal sorption followed the order of Cu(II)>Cd(II)>Ni(II). The regeneration studies indicated that EDTA desorbed Cd(II), Cu(II) and Ni(II) from cross-linking microspheres better than HCl. The FT-IR and XPS spectra showed that coordination bonds were formed between Cd(II), Cu(II) and Ni(II) and the nitrogen atoms of cross-linking CTS/REC nano-hybrid composite microspheres.

  17. Hierarchical aqueous self-assembly of C60 nano-whiskers and C60-silver nano-hybrids under continuous flow.

    Science.gov (United States)

    Iyer, K Swaminathan; Raston, Colin L; Saunders, Martin

    2007-09-01

    The ubiquitous starch-iodine complex can be used to organize hydrophobic fullerene C(60) in water into nano-whiskers shrouded by the biopolymer, and are approximately 5-8 nm in cross section, and 250-350 nm in length, as a hierarchical self assembly process. The preformed starch-iodine complex reacts with solid pristine C(60) affording nano-whiskers with iodine surrounding the fullerene array, the iodine then being removed on treatment with ascorbic acid. The hydrophobic surface of the nano-whiskers of C(60) can be coated with silver metal in a controlled way using 'soft energy' spinning disc processing.

  18. On the electromechanical modelling of a resonating nano-cantilever-based transducer

    DEFF Research Database (Denmark)

    Teva, J.; Abadal, G.; Davis, Zachary James;

    2004-01-01

    An electromechanical model for a transducer based on a lateral resonating cantilever is described. The on-plane vibrations of the cantilever are excited electrostatically by applying DC and AC voltages from a driver electrode placed closely parallel to the cantilever. The model predicts the stati....... Both the static and dynamic predictions have been validated experimentally by measuring the deflection of the cantilever by means of an optical microscope. (C) 2004 Elsevier B.V. All rights reserved....

  19. A Compact Wide-Band Hybrid Dielectric Resonator Antenna with Enhanced Gain and Low Cross-Polarization

    Directory of Open Access Journals (Sweden)

    Feibiao Dong

    2017-01-01

    Full Text Available By loading two printed patches to the dielectric resonator antenna (DRA, a compact wide-band hybrid dielectric resonator antenna with enhanced gain and low cross-polarization is presented. The proposed antenna utilizes a combination of a rectangular dielectric resonator and two printed patches. Due to the hybrid design, multiple resonances were obtained. By adding two air layers between the dielectric resonator and the printed patches, the bandwidth has been significantly improved. Compared to the traditional hybrid dielectric resonator antenna, the proposed antenna can achieve wide bandwidth, high gain, low cross-polarization, and even small size simultaneously. The prototype of the proposed antenna has been fabricated and tested. The measured −10 dB return loss bandwidth is 25.6% (1.7–2.2 GHz. The measured antenna gains are about 6.3 and 8.2 dBi in the operating frequency band. Low cross-polarization levels of less than −28.5 dB and −43 dB in the E-plane and H-plane are achieved. Moreover, the overall dimensions of the antenna are only 67 × 67 × 34 (mm3. The proposed antenna is especially attractive for small base antenna applications.

  20. Evaluation of hybrid sol-gel incorporated with nanoparticles as nano paint

    Science.gov (United States)

    Jameel, Zainab N.; Haider, Adawiya J.; Taha, Samar Y.; Gangopadhyay, Shubhra; Bok, Sangho

    2016-07-01

    A coating with self-cleaning characteristics has been developed using a TiO2/SiO2 hybrid sol-gel, TiO2 nanoparticles and organosilicate nanoparticles (OSNP). A patented technology of the hybrid sol-gel and OSNP was combined with TiO2 nanoparticles to create the surface chemistry for self-cleaning. Two synthesis methods have been developed to prepare TiO2 nanoparticles (NPs), resulting in the enhancement of local paint by the addition of anatase and rutile TiO2 phases. The NPs size as determined by Dynamic Light Scattering (DLS) ranges within of (3-4) and (20-42) nm, which was also confirmed by Scanning Electron Microscopy (SEM). The nanoparticles showed surface charge (zeta-potential, ζ) of +35 and +25.62 mV for the methods, respectively, and ζ values of +41.31 and 34.02 mV for anatase and rutile phases, respectively. The NPs were mixed with the coating solution (i.e., hybrid sol-gel and OSNP) in different concentrations and thin films were prepared by spin coating. Self-cleaning tests were performed using Rhodamine B (RhB) as a pollution indicator. The effect of UV-irradiation on the films was also studied. Anatase and rutile incorporated as a mixture with different ratios in local paint and washability as well as a contrast ratio tests were performed. It was found that the addition of TiO2 NPs in combination with irradiation show a great enhancement of RhB degradation (1%) wt. with a decrease in contact angle and improved washability.

  1. Evaluation of hybrid sol-gel incorporated with nanoparticles as nano paint

    Energy Technology Data Exchange (ETDEWEB)

    Jameel, Zainab N., E-mail: zeinb76-alrekbe@yahoo.com; Haider, Adawiya J., E-mail: adawiyahaider@yahoo.com [Nanotechnology and Advanced Materials Research Center, The University of Technology, Baghdad (Iraq); Taha, Samar Y., E-mail: samarjam2002@yahoo.com [College of Science for Women, University of Baghdad, Baghdad (Iraq); Gangopadhyay, Shubhra, E-mail: gangopadhyays@missouri.edu; Bok, Sangho, E-mail: BokSa@missouri.edu [Department of Electrical and Computer, University of Missouri, Engineering, Building West, Columbia, Missouri 65211 (United States)

    2016-07-25

    A coating with self-cleaning characteristics has been developed using a TiO{sub 2}/SiO{sub 2} hybrid sol-gel, TiO{sub 2} nanoparticles and organosilicate nanoparticles (OSNP). A patented technology of the hybrid sol-gel and OSNP was combined with TiO{sub 2} nanoparticles to create the surface chemistry for self-cleaning. Two synthesis methods have been developed to prepare TiO{sub 2} nanoparticles (NPs), resulting in the enhancement of local paint by the addition of anatase and rutile TiO{sub 2} phases. The NPs size as determined by Dynamic Light Scattering (DLS) ranges within of (3-4) and (20-42) nm, which was also confirmed by Scanning Electron Microscopy (SEM). The nanoparticles showed surface charge (zeta-potential, ζ) of +35 and +25.62 mV for the methods, respectively, and ζ values of +41.31 and 34.02 mV for anatase and rutile phases, respectively. The NPs were mixed with the coating solution (i.e., hybrid sol-gel and OSNP) in different concentrations and thin films were prepared by spin coating. Self-cleaning tests were performed using Rhodamine B (RhB) as a pollution indicator. The effect of UV-irradiation on the films was also studied. Anatase and rutile incorporated as a mixture with different ratios in local paint and washability as well as a contrast ratio tests were performed. It was found that the addition of TiO{sub 2} NPs in combination with irradiation show a great enhancement of RhB degradation (1%) wt. with a decrease in contact angle and improved washability.

  2. Clinical Evaluation of Silorane and Nano-hybrid Resin Composite Restorations in Class II Cavities up to 3 Years.

    Science.gov (United States)

    Öztürk-Bozkurt, F; Toz, T; Kara-Tuncer, A; Gözükara-Bağ, H; Özcan, M

    In this study, the clinical performance of a silorane-based resin composite (SC) vs a nano-hybrid resin composite (NHC) was evaluated in Class II cavities. From January 2012 to February 2013, a total of 29 patients (eight men, 21 women; mean age, 24 ± 5 years) received 29 pairs of restorations using both SC (Filtek Silorane, 3M ESPE) and NHC (Filtek Z550, 3M ESPE) materials. Patients were followed until February 2015. One operator performed all restorations using the corresponding adhesive resins according to the manufacturers' instructions. Two calibrated independent examiners evaluated the restorations at one week, six months, and then annually using the modified United States Public Health Service (USPHS) criteria for anatomic form, marginal adaptation, color match, surface roughness, marginal discoloration, secondary caries, and postoperative sensitivity. Changes in the USPHS parameters were analyzed with the McNemar test (α=0.05). The mean observation period was 31.2 months. Marginal adaptation was the only parameter that showed a significant difference and was worse for SC than NHC (p=0.012). At the final recall, 17 restorations from the SC group and five from the NHC group received a score of 1 (explorer catches). These scores were significantly different between baseline and final recall for SC (p0.05). Both NHC and SC performed similarly in Class II restorations up to three years except for marginal adaptation, for which the latter demonstrated significant deterioration at the final recall compared with baseline.

  3. Hybrid metal-dielectric ring resonators for homogenizable optical metamaterials with strong magnetic response at short wavelengths down to the ultraviolet range.

    Science.gov (United States)

    Tang, Jianwei; He, Sailing

    2013-10-07

    We derive an analytical LC model from Maxwell's equations for the magnetic resonance of subwavelength ring resonators. Using the LC model, we revisit the scaling of split-ring resonators. Inspired by the LC model, we propose a hybrid metal-dielectric ring resonator mainly composed of high index dielectric material (e.g., TiO₂) with some gaps filled with metal (e.g., Ag). The saturation frequency of magnetic response for the hybrid metal-dielectric ring resonator is much higher (up to the ultraviolet range) than that for split-ring resonators, and can be controlled by the metal fraction in the ring. The hybrid metal-dielectric ring resonator can also overcome the homogenization problem of all-dielectric magnetic resonators, and therefore can form homogenizable magnetic metamaterials at short wavelengths down to the ultraviolet range.

  4. Application of Nuclear Magnetic Resonance and Hybrid Methods to Structure Determination of Complex Systems.

    Science.gov (United States)

    Prischi, Filippo; Pastore, Annalisa

    2016-01-01

    The current main challenge of Structural Biology is to undertake the structure determination of increasingly complex systems in the attempt to better understand their biological function. As systems become more challenging, however, there is an increasing demand for the parallel use of more than one independent technique to allow pushing the frontiers of structure determination and, at the same time, obtaining independent structural validation. The combination of different Structural Biology methods has been named hybrid approaches. The aim of this review is to critically discuss the most recent examples and new developments that have allowed structure determination or experimentally-based modelling of various molecular complexes selecting them among those that combine the use of nuclear magnetic resonance and small angle scattering techniques. We provide a selective but focused account of some of the most exciting recent approaches and discuss their possible further developments.

  5. Colorimetric Detection of Ehrlichia Canis via Nucleic Acid Hybridization in Gold Nano-Colloids

    Directory of Open Access Journals (Sweden)

    Ajima Muangchuen

    2014-08-01

    Full Text Available Canine monocytic ehrlichiosis (CME is a major thick-bone disease of dog caused by Ehrlichia canis. Detection of this causal agent outside the laboratory using conventional methods is not effective enough. Thus an assay for E. canis detection based on the p30 outer membrane protein gene was developed. It was based on the p30 gene amplification using loop-mediated isothermal DNA amplification (LAMP. The primer set specific to six areas within the target gene were designed and tested for their sensitivity and specificity. Detection of DNA signals was based on modulation of gold nanoparticles’ surface properties and performing DNA/DNA hybridization using an oligonucleotide probe. Presence of target DNA affected the gold colloid nanoparticles in terms of particle aggregation with a plasmonic color change of the gold colloids from ruby red to purple, visible by the naked eye. All the assay steps were completed within 90 min including DNA extraction without relying on standard laboratory facilities. This method was very specific to target bacteria. Its sensitivity with probe hybridization was sufficient to detect 50 copies of target DNA. This method should provide an alternative choice for point of care control and management of the disease.

  6. Bioactivity and degradability of hybrids nano-composites materials with great application as bone tissue substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Téllez, D.A.; Téllez-Jurado, L.; Chávez-Alcalá, J.F., E-mail: fchaveza@hotmail.com

    2014-12-05

    Highlights: • pH has an effect on the degradation process of the hybrid materials. • Weight loss depends on the change of pH during the degradation process. • Bioactivity in the materials is strongly related to calcium and pH. - Abstract: In this work, hybrids with great application as bioactive materials having different compositions based on siloxane network were prepared. In vitro bioactivity and in vitro degradability tests were carried out in the materials by soaking them into simulated body fluid (SBF) and into phosphate buffer solution (PBS) to prove their apatite-forming ability and to show their degradation process, respectively. In both in vitro tests, measurements of pH and loss weight were made to observe bioactivity and degradation processes. To prove growth of HA, the materials were characterized through X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. The results showed that some samples have better bioactivity than others. It was found that the incorporation of CaO component into the network of the materials results in an increase of the apatite-forming ability in SBF. Moreover, during the degradation tests, all the samples presented weight loss, especially the ones that contain CaO.

  7. Nanoscale nonlinear PANDA ring resonator

    CERN Document Server

    Yupapin, Preecha

    2012-01-01

    Microring/nanoring resonator is an interesting device that has been widely studied and investigated by researchers from a variety of specializations. This book begins with the basic background of linear and nonlinear ring resonators. A novel design of nano device known as a PANDA ring resonator is proposed. The use of the device in the form of a PANDA in applications such as nanoelectronics, measurement, communication, sensors, optical and quantum computing, drug delivery, hybrid transistor and a new concept of electron-hole pair is discussed in detail.

  8. Tailoring the surface plasmon resonance of embedded silver nanoparticles by combining nano- and femtosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Doster, J.; Baraldi, G.; Gonzalo, J.; Solis, J.; Hernandez-Rueda, J.; Siegel, J., E-mail: j.siegel@io.cfmac.csic.es [Laser Processing Group, Instituto de Optica, Serrano 121, 28006 Madrid (Spain)

    2014-04-14

    We demonstrate that the broad surface plasmon resonance (SPR) of a single layer of near-coalescence silver nanoparticles (NPs), embedded in a dielectric matrix can be tailored by irradiation with a single nanosecond laser pulse into a distribution featuring a sharp resonance at 435 nm. Scanning electron microscopy studies reveal the underlying mechanism to be a transformation into a distribution of well-separated spherical particles. Additional exposure to multiple femtosecond laser pulses at 400 nm or 800 nm wavelength induces polarization anisotropy of the SPR, with a peak shift that increases with laser wavelength. The spectral changes are measured in-situ, employing reflection and transmission micro-spectroscopy with a lateral resolution of 4 μm. Spectral maps as a continuous function of local fluence can be readily produced from a single spot. The results open exciting perspectives for dynamically tuning and switching the optical response of NP systems, paving the way for next-generation applications.

  9. BRET: NanoLuc-Based Bioluminescence Resonance Energy Transfer Platform to Monitor Protein-Protein Interactions in Live Cells.

    Science.gov (United States)

    Mo, Xiu-Lei; Fu, Haian

    2016-01-01

    Bioluminescence resonance energy transfer (BRET) is a prominent biophysical technology for monitoring molecular interactions, and has been widely used to study protein-protein interactions (PPI) in live cells. This technology requires proteins of interest to be associated with an energy donor (i.e., luciferase) and an acceptor (e.g., fluorescent protein) molecule. Upon interaction of the proteins of interest, the donor and acceptor will be brought into close proximity and energy transfer of chemical reaction-induced luminescence to its corresponding acceptor will result in an increased emission at an acceptor-defined wavelength, generating the BRET signal. We leverage the advantages of the superior optical properties of the NanoLuc(®) luciferase (NLuc) as a BRET donor coupled with Venus, a yellow fluorescent protein, as acceptor. We term this NLuc-based BRET platform "BRET(n)". BRET(n) has been demonstrated to have significantly improved assay performance, compared to previous BRET technologies, in terms of sensitivity and scalability. This chapter describes a step-by-step practical protocol for developing a BRET(n) assay in a multi-well plate format to detect PPIs in live mammalian cells.

  10. Whole-body magnetic resonance angiography at 3 tesla using a hybrid protocol in patients with peripheral arterial disease

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Eiberg, Jonas P; Logager, Vibeke B

    2009-01-01

    The purpose of this study was to determine the diagnostic performance of 3T whole-body magnetic resonance angiography (WB-MRA) using a hybrid protocol in comparison with a standard protocol in patients with peripheral arterial disease (PAD). In 26 consecutive patients with PAD two different proto...

  11. Observations of magnetospheric ionization enhancements using upper-hybrid resonance noise band data from the RAE-1 satellite

    Science.gov (United States)

    Mosier, S. R.

    1975-01-01

    Noise bands associated with the upper-hybrid resonance were used to provide direct evidence for the existence of regions of enhanced density in the equatorial magnetosphere near L = 2. Density enhancements ranging from several percent to as high as 45 percent are observed with radial dimensions of several hundred kilometers. The enhancement characteristics strongly suggest their identification as magnetospheric whistler ducts.

  12. Applications of the Hybrid Theory to the Scattering of Electrons from HE+ and Li++ and Resonances in these Systems

    Science.gov (United States)

    Bhatia, Anand K.

    2008-01-01

    Applications of the hybrid theory to the scattering of electrons from Ile+ and Li++ and resonances in these systems, A. K. Bhatia, NASA/Goddard Space Flight Center- The Hybrid theory of electron-hydrogen elastic scattering [I] is applied to the S-wave scattering of electrons from He+ and Li++. In this method, both short-range and long-range correlations are included in the Schrodinger equation at the same time. Phase shifts obtained in this calculation have rigorous lower bounds to the exact phase shifts and they are compared with those obtained using the Feshbach projection operator formalism [2], the close-coupling approach [3], and Harris-Nesbet method [4]. The agreement among all the calculations is very good. These systems have doubly-excited or Feshbach resonances embedded in the continuum. The resonance parameters for the lowest ' S resonances in He and Li+ are calculated and they are compared with the results obtained using the Feshbach projection operator formalism [5,6]. It is concluded that accurate resonance parameters can be obtained by the present method, which has the advantage of including corrections due to neighboring resonances and the continuum in which these resonances are embedded.

  13. Research on beam characteristics in a large-Fresnel-number unstable-waveguide hybrid resonator with parabolic mirrors.

    Science.gov (United States)

    Wang, Wei; Qin, Yingxiong; Xiao, Yu; Zhong, Lijing; Wu, Chao; Wang, Zhen; Wan, Wen; Tang, Xiahui

    2016-07-20

    Large-Fresnel-number unstable-waveguide hybrid resonators employing spherical resonator mirrors suffer from spherical aberration, which adversely affects beam quality and alignment sensitivity. In this paper, we present experimental and numerical wave-optics simulations of the beam characteristics of a negative-branch hybrid resonator having parabolic mirrors with a large equivalent Fresnel number in the unstable direction. These results are compared with a resonator using spherical mirrors. Using parabolic mirrors, the output beam has a smaller beam spot size and higher power density at the focal plane. We found that the power extraction efficiency is 3.5% higher when compared with a resonator using spherical mirrors as the cavity length was varied between -1 and 1 mm from the ideal confocal resonator. In addition, the power extraction efficiency is 5.6% higher for mirror tilt angles varied between -6 and 6 mrad. Furthermore, the output propagating field is similar to a converging wave for a spherical mirror resonator and the output beam direction deviates 3.5 mrad from the optical axis. The simulation results are in good agreement with the experimental results.

  14. Observation of microarray DNA hybridization using surface plasmon resonance phase-shift interferometry

    Science.gov (United States)

    Chen, Shean-Jen; Tsou, C.-Y.; Chen, Y.-K.; Su, Y.-T.

    2004-06-01

    Surface plasmon resonance phase-shift interferometry (SPR-PSI) is a novel technique which combines SPR and modified Mach-Zehnder phase-shifting interferometry to measure the spatial phase variation caused by biomolecular interactions upon a sensing chip. The SPR-PSI imaging system offers high resolution and high-throughout screening capabilities for microarray DNA hybridization without the need for additional labeling, and provides valuable real-time quantitative information. Current SPR-PSI imaging systems measure the spatial phase variation caused by tiny biomolecular changes on the sensing interface by means of a five-step phase reconstruction algorithm and a novel multichannel least mean squares (MLMS) phase unwrapping algorithm. The SPR-PSI imaging system has an enhanced detection limit of 2.5 × 10-7 refraction index change, a long-term phase stability of π/100 in 30 minutes, and a spatial phase resolution of π/500 with a lateral resolution of 10μm. This study successfully demonstrates the kinetic and label-free observation of 5-mer DNA microarray hybridization.

  15. Resonant photothermal laser processing of hybrid gold/titania nanoparticle films

    Science.gov (United States)

    Schade, Lina; Franzka, Steffen; Dzialkowski, Kevin; Hardt, Sebastian; Wiggers, Hartmut; Reichenberger, Sven; Wagener, Philipp; Hartmann, Nils

    2015-05-01

    Photothermal processing of thin anatase TiO2 and hybrid Au/anatase TiO2 nanoparticle films on glass supports is investigated using continuous-wave microfocused lasers at λ = 355 nm and λ = 532 nm. UV/Vis spectroscopy, Raman spectroscopy, optical microscopy, atomic force microscopy and scanning electron microscopy are used for characterization. Processing of TiO2 nanoparticle films is feasible at λ = 355 nm only. In contrast, the addition of Au nanoparticles enhances the overall absorbance of the material in the visible range and enables processing at both wavelengths, i.e. at λ = 355 nm and λ = 532 nm. Generally, laser heating induces a transition from anatase to rutile. The modification degree increases with increasing laser power and laser irradiation time. Resonant laser processing of hybrid Au/TiO2-mesoporous films provide promising perspectives in various applications, e.g. in photovoltaics, where embedded nanoparticulate Au could be exploited to enhance light trapping.

  16. Excitation and Imaging of Resonant Optical Modes of Au Triangular Nano-Antennas Using Cathodoluminescence Spectroscopy

    CERN Document Server

    Kumar, Anil; Mabon, James C; Chow, Edmond; Fang, Nicholas X

    2010-01-01

    Cathodoluminescence (CL) imaging spectroscopy is an important technique to understand resonant behavior of optical nanoantennas. We report high-resolution CL spectroscopy of triangular gold nanoantennas designed with near-vacuum effective index and very small metal-substrate interface. This design helped in addressing issues related to background luminescence and shifting of dipole modes beyond visible spectrum. Spatial and spectral investigations of various plasmonic modes are reported. Out-of-plane dipole modes excited with vertically illuminated electron beam showed high-contrast tip illumination in panchromatic imaging. By tilting the nanostructures during fabrication, in-plane dipole modes of antennas were excited. Finite-difference time-domain simulations for electron and optical excitations of different modes showed excellent agreement with experimental results. Our approach of efficiently exciting antenna modes by using low index substrates is confirmed both with experiments and numerical simulations....

  17. A quantum spin transducer based on nano electro-mechancial resonator arrays

    CERN Document Server

    Rabl, P; Koppens, F H; Harris, J G E; Zoller, P; Lukin, M D

    2009-01-01

    Implementation of quantum information processing faces the contradicting requirements of combining excellent isolation to avoid decoherence with the ability to control coherent interactions in a many-body quantum system. For example, spin degrees of freedom of electrons and nuclei provide a good quantum memory due to their weak magnetic interactions with the environment. However, for the same reason it is difficult to achieve controlled entanglement of spins over distances larger than tens of nanometers. Here we propose a universal realization of a quantum data bus for electronic spin qubits where spins are coupled to the motion of magnetized mechanical resonators via magnetic field gradients. Provided that the mechanical system is charged, the magnetic moments associated with spin qubits can be effectively amplified to enable a coherent spin-spin coupling over long distances via Coulomb forces. Our approach is applicable to a wide class of electronic spin qubits which can be localized near the magnetized tip...

  18. A tapered undulator experiment at the ELBE far infrared hybrid-resonator oscillator free electron laser.

    Science.gov (United States)

    Asgekar, V; Lehnert, U; Michel, P

    2012-01-01

    A tapered undulator experiment was carried out at the ELBE far-infrared free electron laser (FEL). The oscillator FEL makes use of a hybrid optical resonator. The main motivation was to see whether the presence of a dispersive medium in the form of a waveguide in the resonator has any effect on the outcome. The FEL saturated power and the wavelength shifts have been measured as a function of both positive as well as negative undulator field amplitude tapering. In contrast to the typical high-gain FELs where positive tapering proves beneficial for the output power we observed an improvement of performance at negative taper. During the same experiments we studied the characteristics of the detuning curves. The width of the curves indicates a maximum small signal gain for zero taper while the output peak power increases with negative taper. The saturated power output, the detuning curve characteristics, and the wavelength shifts agrees with the theoretical predictions. Details of the experiment are presented.

  19. Effects of hybrid synapses on the vibrational resonance in small-world neuronal networks.

    Science.gov (United States)

    Yu, Haitao; Wang, Jiang; Sun, Jianbing; Yu, Haifeng

    2012-09-01

    We investigate the effect of vibrational resonance in small-world neuronal networks with hybrid chemical and electrical synapses. It is shown that, irrespective of the probability of chemical synapses, an optimal amplitude of high-frequency component of the signal can optimize the dynamical response of neuron populations to the low-frequency component, which encodes the information. This effect of vibrational resonance of neuronal systems depends extensively on the network structure and parameters, which determine the ability of neuronal networks to enhance the outreach of localized subthreshold low-frequency signal. In particular, chemical synaptic coupling is more efficient than the electrical coupling for the transmission of local input signal due to its selective coupling. Moreover, there exists an optimal small-world topology characterized by an optimal value of rewiring probability, warranting the largest peak value of the system response. Considering that two-frequency signals are ubiquity in brain dynamics, we expect the presented results could have important implications for signal processing in neuronal systems.

  20. Construction of organic–inorganic hybrid nano-coatings containing α-zirconium phosphate with high efficiency for reducing fire hazards of flexible polyurethane foam

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Ying [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Pan, Haifeng; Yuan, Bihe [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, Suzhou, Jiangsu 215123 (China); Hong, Ningning; Zhan, Jing; Wang, Bibo [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Song, Lei, E-mail: leisong@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, Suzhou, Jiangsu 215123 (China)

    2015-08-01

    Nano-architecture on the flexible polyurethane foam (FPUF) was built by layer by layer (LbL) self-assembling of α-zirconium phosphate (α-ZrP) and two biopolymers. Through electrostatic attraction and hydrogen bonding between α-ZrP, chitosan and alginate, the nano-coatings were successfully deposited on the substrate. The LbL self-assembly coatings were characterized by X-ray diffraction, UV–vis absorption spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy and scanning electron microscopy. This loaded nano-coating endowed FPUF with excellent flame retardancy. Compared with pure FPUF, the reduction in the peak heat release rate of the modified foam with 12.3 wt% weight gain was achieved 71%, and the melt-dripping during combustion disappeared. Meanwhile, the thermal degradation of coated FPUF under nitrogen atmosphere was obviously retarded compared with pure FPUF. Additionally, the mechanical properties of the treated FPUFs were investigated. After loaded with 12.3 wt% nano-coating, the tensile and tear strength were enhanced by 13% and 54%, respectively. These investigations indicated that the study has great potential to add new dimensions in the fire retardancy modification of FPUF. - Highlights: • The nano-coatings containing α-ZrP and two biopolymers were successfully loaded on the FPUF by LbL self-assembly method. • The hybrid nano-coatings exhibited marked reduction in the peak heat release rate of the foam. • The coating resulted in enhanced tensile and tear strength of the foam.

  1. Hybrid Energy Cell with Hierarchical Nano/Micro-Architectured Polymer Film to Harvest Mechanical, Solar, and Wind Energies Individually/Simultaneously.

    Science.gov (United States)

    Dudem, Bhaskar; Ko, Yeong Hwan; Leem, Jung Woo; Lim, Joo Ho; Yu, Jae Su

    2016-11-09

    We report the creation of hybrid energy cells based on hierarchical nano/micro-architectured polydimethylsiloxane (HNMA-PDMS) films with multifunctionality to simultaneously harvest mechanical, solar, and wind energies. These films consist of nano/micro dual-scale architectures (i.e., nanonipples on inverted micropyramidal arrays) on the PDMS surface. The HNMA-PDMS is replicable by facile and cost-effective soft imprint lithography using a nanoporous anodic alumina oxide film formed on the micropyramidal-structured silicon substrate. The HNMA-PDMS film plays multifunctional roles as a triboelectric layer in nanogenerators and an antireflection layer for dye-sensitized solar cells (DSSCs), as well as a self-cleaning surface. This film is employed in triboelectric nanogenerator (TENG) devices, fabricated by laminating it on indium-tin oxide-coated polyethylene terephthalate (ITO/PET) as a bottom electrode. The large effective contact area that emerged from the densely packed hierarchical nano/micro-architectures of the PDMS film leads to the enhancement of TENG device performance. Moreover, the HNMA-PDMS/ITO/PET, with a high transmittance of >90%, also results in highly transparent TENG devices. By placing the HNMA-PDMS/ITO/PET, where the ITO/PET is coated with zinc oxide nanowires, as the top glass substrate of DSSCs, the device is able to add the functionality of TENG devices, thus creating a hybrid energy cell. The hybrid energy cell can successfully convert mechanical, solar, and wind energies into electricity, simultaneously or independently. To specify the device performance, the effects of external pushing frequency and load resistance on the output of TENG devices are also analyzed, including the photovoltaic performance of the hybrid energy cells.

  2. Nuclear magnetic resonance applied to the study of polymeric nano composites; Ressonancia magnetica nuclear aplicada do estudo de nanocompositos polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Maria Ines Bruno [Instituto de Macromoleculas Professora Eloisa Mano da Universidade Federal do Rio de Janeiro, UFRJ - RJ (Brazil)

    2011-07-01

    Polymers and nanoparticles based nano composites were prepared by intercalation by solution. The obtained nano composites were characterized mainly by the nuclear magnetic spectroscopy (NMR), applying the analysis of carbon-13 (polymeric matrix), silicon-29 (nanoparticle), and by determination of spin-lattice relaxation of the hydrogen nucleus (T{sub 1}H) (polymeric matrix). The NMR have presented a promising technique in the characterization of the nano charge dispersion in the studied polymeric matrixes.

  3. Synthesis of organic-inorganic hybrid sols with nano silica particles and organoalkoxysilanes for transparent and high-thermal-resistance coating films using sol-gel reaction.

    Science.gov (United States)

    Na, Moonkyong; Park, Hoyyul; Ahn, Myeongsang; Lee, Hyeonhwa; Chung, Ildoo

    2010-10-01

    Organic-inorganic hybrid sols were synthesized from nano silica particles dispersed in water and from organoalkoxysilanes, using the sol-gel reaction. This work focuses on the effects of the three multifunctional organoalkoxysilanes dimethyldimethoxysilane (DMDMS), methyltrimethoxysilane (MTMS), and tetramethoxysilane (TMOS) to form a transparent and high-thermal-resistance coating film. The stability of the hybrid sol was evaluated as a function of the reaction time for 10 d through the variation of the viscosity. The viscosity of the silica/DMDMS and silica/MTMS sol was slightly increased for 10 d. The multifunctional organoalkoxysilanes formed dense silica networks through hydrolysis and condensation reaction, which enhanced the thermal resistance of the coating films. No thermal degradation of the silica/DMDMS sample occurred up to 600 degrees C, and none of the silica/MTMS and silica/TMOS samples occurred either up to 700 degrees C. The organic-inorganic hybrid sols were coated on the glass substrate using a spin-coating procedure. The organic-inorganic hybrid sols formed flat coating films without cracks. The transmittance of the hybrid sol coating films using MTMS and DMDMS was shown to be over 90%. The transmittance of the silica/TMOS sol coating film reacted for 10 d abruptly decreased due to faster gelation. The silica/DMDMS and silica/MTMS hybrid sols formed smooth coating films while the surface roughness of the silica/TMOS coating film markedly increased when the hybrid sol reacted for 10 d. The increase of the surface roughness of the silica/TMOS coating film can be attributed to the degradation of the stability of the hybrid sol and to the loss of transmittance of the coating film. It was confirmed in this study that the use of organic-inorganic hybrid sol can yield transparent and high-thermal-resistance coating films.

  4. A new layered nano hybrid perovskite film with enhanced resistance to moisture-induced degradation

    Science.gov (United States)

    Jiang, Wenlong; Ying, Jifei; Zhou, Wei; Shen, Kongchao; Liu, Xing; Gao, Xingyu; Guo, Fuqiang; Gao, Yanmin; Yang, Tieying

    2016-08-01

    In this paper, a new layered hybrid perovskite film ((EDA)(MA)2[Pb3I10]) was synthesized through one-step method. Ethylenediamine (EDA) cation was introduced into the perovskite lattice to synthesize a layered structure with improved resistance to degradation by humidity. The effects of humidity and time on crystal structure, composition, morphology and absorption spectra of (EDA)(MA)2[Pb3I10] were analyzed by in situ grazing incidence X-ray diffraction (GIXRD), scanning electron microscope (SEM), and UV-Vis spectroscope. The results reveal that a (EDA)(MA)2[Pb3I10] film is more moisture resistant than a CH3NH3PbI3 film which is widely used in the perovskite solar cell now. UV-Vis spectroscopy result also shows that the layered structure film is a suitable solar absorber with a bandgap (1.67 eV), which is close to the optimum value for solar photoelectric conversion. Compared to CH3NH3PbI3, the low-cost perovskite structure offers greater tunability on a molecular level for further material optimization and possibility for widely used in the future.

  5. Anomalous spectral shift of near- and far-field plasmonic resonances in nano-gaps

    CERN Document Server

    Lombardi, Anna; Weller, Lee; Andrae, Patrick; Benz, Felix; Chikkaraddy, Rohit; Aizpurua, Javier; Baumberg, Jeremy J

    2016-01-01

    The near-field and far-field spectral response of plasmonic systems are often assumed to be identical, due to the lack of methods that can directly compare and correlate both responses under similar environmental conditions. We develop a widely-tuneable optical technique to probe the near-field resonances within individual plasmonic nanostructures that can be directly compared to the corresponding far-field response. In tightly-coupled nanoparticle-on-mirror constructs with nanometer-sized gaps we find >40meV blueshifts of the near-field compared to the dark-field scattering peak, which agrees with full electromagnetic simulations. Using a transformation optics approach, we show such shifts arise from the different spectral interference between different gap modes in the near- and far-field. The control and tuning of near-field and far-field responses demonstrated here is of paramount importance in the design of optical nanostructures for field-enhanced spectroscopy, as well as to control near-field activity ...

  6. Tunable filters based on an SOI nano-wire waveguide micro ring resonator

    Institute of Scientific and Technical Information of China (English)

    Li Shuai; Wu Yuanda; Yin Xiaojie; An Junming; Li Jianguang; Wang Hongjie; Hu Xiongwei

    2011-01-01

    Micro ring resonator (MRR) filters based on a silicon on insulator (SOI) nanowire waveguide are fabricated by electron beam photolithography (EBL) and inductive coupled plasma (ICP) etching technology.The cross-section size of the strip waveguides is 450 × 220 nm2,and the bending radius of the micro ring is around 5μm.The test results from the tunable filter based on a single ring show that the free spectral range (FSR) is 16.8 nm and the extinction ratio (ER) around the wavelength 1550 nm is 18.1 dB.After thermal tuning,the filter's tuning bandwidth reaches 4.8 nm with a tuning efficiency of 0.12 nm/℃ Meanwhile,we fabricated and studied multi-channel filters based on a single ring and a double ring.After measurement,we drew the following conclusions:during the signal transmission of multi-channel filters,crosstalk exists mainly among different transmission channels and are fairly distinct when there are signals input to add ports.

  7. Effect of Nano-TiC Dispersed Particles and Electro-Codeposition Parameters on Morphology and Structure of Hybrid Ni/TiC Nanocomposite Layers

    Directory of Open Access Journals (Sweden)

    Lidia Benea

    2016-04-01

    Full Text Available This research work describes the effect of dispersed titanium carbide (TiC nanoparticles into nickel plating bath on Ni/TiC nanostructured composite layers obtained by electro-codeposition. The surface morphology of Ni/TiC nanostructured composite layers was characterized by scanning electron microscopy (SEM. The composition of coatings and the incorporation percentage of TiC nanoparticles into Ni matrix were studied and estimated by using energy dispersive X-ray analysis (EDX. X-ray diffractometer (XRD has been applied in order to investigate the phase structure as well as the corresponding relative texture coefficients of the composite layers. The results show that the concentration of nano-TiC particles added in the nickel electrolyte affects the inclusion percentage of TiC into Ni/TiC nano strucured layers, as well as the corresponding morphology, relative texture coefficients and thickness indicating an increasing tendency with the increasing concentration of nano-TiC concentration. By increasing the amount of TiC nanoparticles in the electrolyte, their incorporation into nickel matrix also increases. The hybrid Ni/nano-TiC composite layers obtained revealed a higher roughness and higher hardness; therefore, these layers are promising superhydrophobic surfaces for special application and could be more resistant to wear than the pure Ni layers.

  8. Multi-resonant silver nano-disk patterned thin film hydrogenated amorphous silicon solar cells for Staebler-Wronski effect compensation

    CERN Document Server

    Vora, Ankit; Pearce, Joshua M; Bergstrom, Paul L; Güney, Durdu Ö

    2014-01-01

    We study polarization independent improved light trapping in commercial thin film hydrogenated amorphous silicon (a-Si:H) solar photovoltaic cells using a three-dimensional silver array of multi-resonant nano-disk structures embedded in a silicon nitride anti-reflection coating (ARC) to enhance optical absorption in the intrinsic layer (i-a-Si:H) for the visible spectrum for any polarization angle. Predicted total optical enhancement (OE) in absorption in the i-a-Si:H for AM-1.5 solar spectrum is 18.51% as compared to the reference, and producing a 19.65% improvement in short-circuit current density (JSC) over 11.7 mA/cm2 for a reference cell. The JSC in the nano-disk patterned solar cell (NDPSC) was found to be higher than the commercial reference structure for any incident angle. The NDPSC has a multi-resonant optical response for the visible spectrum and the associated mechanism for OE in i-a-Si:H layer is excitation of Fabry-Perot resonance facilitated by surface plasmon resonances. The detrimental Staebl...

  9. Chemical detection with nano/bio hybrid devices based on carbon nanotubes and graphene

    Science.gov (United States)

    Lerner, Mitchell Bryant

    Carbon nanotube field-effect transistors (NT-FETs) and graphene field effect transistors (GFETs) provide a unique transduction platform for chemical and biomolecular detection. The work presented in this thesis describes the fabrication, characterization, and investigation of operational mechanisms of carbon-based biosensors. In the first set of experiments, we used carbon nanotubes as fast, all-electronic readout elements in novel vapor sensors, suitable for applications in environmental monitoring and medicine. Molecules bound to the hybrid alter the electrical properties of the NT-FET via several mechanisms, allowing direct detection as a change in the transistor conduction properties. Vapor sensors suitable for more complex system architectures characteristic of mammalian olfaction were demonstrated using NT-FETs functionalized with mouse olfactory receptor (mOR) proteins or single stranded DNA (ssDNA). Substitution of graphene as the channel material enabled production of hundreds of electronically similar devices with high yield. Etching large scale chemical vapor deposition (CVD)-grown graphene into small channels is itself a challenging problem, and we have developed novel fabrication methods to this end without sacrificing the inherent electrical quality that makes graphene such an attractive material. Large arrays of such devices have potential utility for understanding the physics of ligand-receptor interactions and contributing to the development of a new generation of devices for electronic olfaction. Tailored and specific detection was accomplished by chemically functionalizing the NT-FET or GFET with biomolecules, such as proteins or small molecules, to create a hybrid nanostructures. Targets for detection were widely varied, indicating the utility of these techniques, such as 1) live Salmonella cells in nutrient broth, 2) a biomarker protein indicative of prostate cancer, 3) antigen protein from the bacterium that causes Lyme disease, and 4) glucose

  10. Localized surface plasmon resonance-based hybrid Au-Ag nanoparticles for detection of Staphylococcus aureus enterotoxin B

    Science.gov (United States)

    Zhu, Shaoli; Du, ChunLei; Fu, Yongqi

    2009-09-01

    A triangular hybrid Au-Ag nanoparticles array was proposed for the purpose of biosensing in this paper. Constructing the hybrid nanoparticles, an Au thin film is capped on the Ag nanoparticles which are attached on glass substrate. The hybrid nanoparticles array was designed by means of finite-difference and time-domain (FDTD) algorithm-based computational numerical calculation and optimization. Sensitivity of refractive index of the hybrid nanoparticles array was obtained by the computational calculation and experimental detection. Moreover, the hybrid nanoparticles array can prevent oxidation of the pure Ag nanoparticles from atmosphere environment because the Au protective layer was deposited on top of the Ag nanoparticles so as to isolate the Ag particles from the atmosphere. We presented a novel surface covalent link method between the localized surface plasmon resonance (LSPR) effect-based biosensors with hybrid nanoparticles array and the detected target molecules. The generated surface plasmon wave from the array carries the biological interaction message into the corresponding spectra. Staphylococcus aureus enterotoxin B (SEB), a small protein toxin was directly detected at nanogramme per milliliter level using the triangular hybrid Au-Ag nanoparticles. Hence one more option for the SEB detection is provided by this way.

  11. Oil/water nano-emulsion loaded with cobalt ferrite oxide nanocubes for photo-acoustic and magnetic resonance dual imaging in cancer: in vitro and preclinical studies.

    Science.gov (United States)

    Vecchione, Raffaele; Quagliariello, Vincenzo; Giustetto, Pierangela; Calabria, Dominic; Sathya, Ayyappan; Marotta, Roberto; Profeta, Martina; Nitti, Simone; Silvestri, Niccolò; Pellegrino, Teresa; Iaffaioli, Rosario V; Netti, Paolo Antonio

    2017-01-01

    Dual imaging dramatically improves detection and early diagnosis of cancer. In this work we present an oil in water (O/W) nano-emulsion stabilized with lecithin and loaded with cobalt ferrite oxide (Co0.5Fe2.5O4) nanocubes for photo-acoustic and magnetic resonance dual imaging. The nanocarrier is responsive in in vitro photo-acoustic and magnetic resonance imaging (MRI) tests. A clear and significant time-dependent accumulation in tumor tissue is shown in in vivo photo-acoustic studies on a murine melanoma xenograft model. The proposed O/W nano-emulsion exhibits also high values of r2/r1 (ranging from 45 to 85, depending on the magnetic field) suggesting a possible use as T2 weighted image contrast agents. In addition, viability and cellular uptake studies show no significant cytotoxicity on the fibroblast cell line. We also tested the O/W nano-emulsion loaded with curcumin against melanoma cancer cells demonstrating a significant cytotoxicity and thus showing possible therapeutic effects in addition to the in vivo imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Thermal decomposition assisted synthesis and upconversion property of Fe3O4@YPO4:Tm/Yb hybrid nano-composite phosphor

    Science.gov (United States)

    Tiwari, S. P.; Kumar, K.; Rai, V. K.

    2015-06-01

    Hybrid nano-composite phosphor has been successfully synthesized through thermal decomposition method. The dual phase of samples assigned by XRD analysis shows the formation of nano-composite with crystallite size 20 nm and 12 nm for YPO4: Tm/Yb and Fe3O4@YPO4:Tm/Yb respectively. The FESEM images show the spherical shape and non agglomerated formation of nanoparticles. Three bands in upconversion emission mode were found in intense blue at 472 nm, red at 662 nm and NIR at 798 nm regions corresponding to1G4 → 3H6, 1G4 → 3F4 and 3H4 → 3H6 transition states respectively. The lifetime for1G4 → 3H6 level is found 1150 microsecond and 1400 microsecond for YPO4: Tm/Yb and Fe3O4@YPO4:Tm/Yb samples respectively.

  13. Electric-Field-Induced Amplitude Tuning of Ferromagnetic Resonance Peak in Nano-granular Film FeCoB-SiO2/PMN-PT Composites

    Science.gov (United States)

    Luo, Mei; Zhou, Peiheng; Liu, Yunfeng; Wang, Xin; Xie, Jianliang

    2016-11-01

    One of the challenges in the design of microwave absorbers lies in tunable amplitude of dynamic permeability. In this work, we demonstrate that electric-field-induced magnetoelastic anisotropy in nano-granular film FeCoB-SiO2/PMN-PT (011) composites can be used to tune the amplitude of ferromagnetic resonance peak at room temperature. The FeCoB magnetic particles are separated from each other by SiO2 insulating matrix and present slightly different in-plane anisotropy fields. As a result, multi-resonances appear in the imaginary permeability ( μ″) curve and mixed together to form a broadband absorption peak. The amplitude of the resonance peak could be modulated by external electric field from 118 to 266.

  14. Resonant photoluminescence and dynamics of a hybrid Mn hole spin in a positively charged magnetic quantum dot

    Science.gov (United States)

    Lafuente-Sampietro, A.; Boukari, H.; Besombes, L.

    2017-06-01

    We analyze, through resonant photoluminescence, the spin dynamics of an individual magnetic atom (Mn) coupled to a hole in a semiconductor quantum dot. The hybrid Mn hole spin and the positively charged exciton in a CdTe/ZnTe quantum dot form an ensemble of Λ systems which can be addressed optically. Autocorrelation of the resonant photoluminescence and resonant optical pumping experiments are used to study the spin relaxation channels in this multilevel spin system. We identified for the hybrid Mn hole spin an efficient relaxation channel driven by the interplay of the Mn hole exchange interaction and the coupling to acoustic phonons. We also show that the optical Λ systems are connected through inefficient spin flips than can be enhanced under weak transverse magnetic field. The dynamics of the resonant photoluminescence in a p -doped magnetic quantum dot is well described by a complete rate equation model. Our results suggest that long-lived hybrid Mn hole spin could be obtained in quantum dot systems with large heavy-hole/light-hole splitting.

  15. Improving tribocorroson behaviour by electro-codeposition of TiC nano-dispersed particles with nickel as hybrid layers for energy applications

    Science.gov (United States)

    Benea, Lidia; Dănăilă, Eliza; Ponthiaux, Pierre; Celis, Jean-Pierre

    2017-02-01

    In this paper, the results on the surface morphology, nanohardness and tribocorrosion properties of electrodeposited nanostructured Ni/TiC hybrid layers compared with pure Ni layers are presented. The Ni/nano-TiC hybrid layers were obtained by electro-codeposition of TiC nanoparticles (50 nm mean diameter) with nickel from a Watts type bath, on 316L stainless steel support. The combined fretting-corrosion performance was investigated using a reciprocating ball-on-disk tribometer coupled to an electrochemical cell in an electrolyte which simulates the primary water circuit of Pressurized Water Reactors (PWRs). Open circuit potential, as in situ electrochemical technique was performed before, during and after fretting tests in order to obtain information on the changes in surface conditions induced by fretting. The results clearly revealed enhanced nanohardness, improved tribocorrosion properties and reduced coefficients of friction for Ni/nano-TiC hybrid layers as compared to pure Ni layers. The much improved nanohardness and tribocorrosion behaviour can be attributed to the TiC nanoparticles reinforced into Ni matrix.

  16. Helium Droplets as Nano-Cryostats for Molecular Spectroscopy: Aggregation, State Selection and Electron Spin Resonance

    Science.gov (United States)

    Ernst, Wolfgang E.

    2009-06-01

    Droplets of about 10^{4} helium atoms generated in a supersonic expansion, represent a nanometer-sized superfluid medium of 0.4 K temperature and can be doped with one or several atoms or molecules that may form complexes in this cold environment. Using two-laser excitation schemes, we were able to identify the alkali trimers K_3, Rb_3, K_2Rb and KRb_2 in their lowest quartet states formed on helium droplets loaded with potassium and rubidium atoms and assign several excited states that underlie both Jahn-Teller and spin-orbit coupling. As helium provides a gentle and only weakly perturbing matrix, it appeared desirable to look for ways to measure fine and hyperfine structure directly in the microwave or radiofrequency regime. In preparation for experiments involving optical detection of electron spin transitions in cold molecules, we studied the electronic spin relaxation in alkali atoms and molecules that reside on the surface of a droplet. Measurements of the circular dichroism in the presence of a magnetic field showed that the populations of Zeeman sublevels in alkali atoms are not thermalized, while for dimers and trimers a temperature of 0.4 K was found, implicitly providing a first determination of the droplet's surface temperature. Optical detection of spin resonance is achieved in an optical pump-probe experiment with the electron spin transition induced in a microwave cavity in a magnetic field between the pump and probe regions. With the pump laser depleting a particular spin state by desorption of the species from the droplet beam or by optical pumping, the probe laser detects the successful spin flip induced by the microwave field. Examples will be presented showing up to 50 Rabi cycles of an electron spin transition on an alkali doped helium droplet during the flight time of 57 μs through the cavity. J. Nagl, G. Auböck, A. W. Hauser, O. Allard, C. Callegari, and W. E. Ernst, Phys. Rev. Lett. 100, 063001(2008)} G. Auböck, J. Nagl, C. Callegari, and

  17. Proposal of a resonant controller for a three phase four wire grid-connected shunt hybrid filter

    DEFF Research Database (Denmark)

    Candela, J. I.; Rodriguez, P.; Luna, A.

    2009-01-01

    of the system. In addition a new hybrid filter topology, that permits to cancel out the homopolar harmonics, is presented in this paper. The good performance of this new topology as well as the proposed controller will be evaluated by means of simulations and experimental results.......This paper present a three-phase four wire hybrid filter able to perform a selective cancellation of harmonic currents based on resonant controllers. As it will be shown in this work, this kind of control permits to enhance the bandwidth of the filter controller, without hindering the stability...

  18. Magnified fluorescence detection of silver(I) ion in aqueous solutions by using nano-graphite-DNA hybrid and DNase I.

    Science.gov (United States)

    Wei, Yin; Li, Bianmiao; Wang, Xu; Duan, Yixiang

    2014-08-15

    This paper describes a novel approach utilizing nano-graphite-DNA hybrid and DNase I for the amplified detection of silver(I) ion in aqueous solutions for the first time. Nano-graphite can effectively quench the fluorescence of dye-labeled cytosine-rich single-stranded DNA due to its strong π-π stacking interactions; however, in the presence of Ag(+), C-Ag(+)-C coordination induces the probe to fold into a hairpin structure, which does not adsorb on the surface of nano-graphite and thus retains the dye fluorescence. Meanwhile, the hairpin structure can be cleaved by DNase I, and in such case Ag(+) is delivered from the complex. The released Ag(+) then binds other dye-labeled single-stranded DNA on the nano-graphite surface, and touches off another target recycling, resulting in the successive release of dye-labeled single-stranded DNA from the nano-graphite, which leads to significant amplification of the signal. The present magnification sensing system exhibits high sensitivity toward Ag(+) with a limit of detection of 0.3nM (S/N=3), which is much lower than the standard for Ag(+) in drinking water recommended by the Environmental Protection Agency (EPA). The selectivity of the sensor for Ag(+) against other biologically and environmentally related metal ions is outstanding due to the high specificity of C-Ag(+)-C formation. Moreover, the sensing system is used for the determination of Ag(+) in river water samples with satisfying results. The proposed assay is simple, cost-effective, and might open the door for the development of new assays for other metal ions or biomolecules. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Two Contemporary Problems in Magnetized Plasmas: the ion-ion hybrid resonator and MHD stability in a snowflake divertor

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, William Anthony [Univ. of California, Los Angeles, CA (United States)

    2014-01-01

    The rst part of the dissertation investigates the e ects of multiple-ions on the propagation of shear Alfv en waves. It is shown that the presence of a second ion-species allows for the formation of an ion-ion hybrid resonator in the presence of a magnetic well. A fullwave description is shown to explain the measured eigenfrequencies and spatial form of the resonator modes identi ed in experiments in the Large Plasma Device (LAPD) at UCLA. However, it is determined that neither electron collisions or radial convection of the mode due to coupling to either the compressional or ion-Bernstein wave can explain the observed dissipation.

  20. Active control of surface plasmon resonance in MoS2-Ag hybrid nanostructures

    CERN Document Server

    Zu, Shuai; Gong, Yongji; Ajayan, Pulickel M; Fang, Zheyu

    2016-01-01

    Molybdenum disulfide (MoS2) monolayers have attracted much attention for their novel optical properties and efficient light-matter interactions. When excited by incident laser, the optical response of MoS2 monolayers was effectively modified by elementary photo-excited excitons owing to their large exciton binding energy, which can be facilitated for the optical-controllable exciton-plasmon interactions. Inspired by this concept, we experimentally investigated active light control of surface plasmon resonance (SPR) in MoS2-Ag hybrid nanostructures. The white light spectra of SPR were gradually red-shifted by increasing laser power, which was distinctly different from the one of bare Ag nanostructure. This spectroscopic tunability can be further controlled by near-field coupling strength and polarization state of light, and selectively applied to the control of plasmonic dark mode. An analytical Lorentz model for photo-excited excitons induced modulation of MoS2 dielectric function was developed to explain the...

  1. Near-Infrared Resonance Energy Transfer Glucose Biosensors in Hybrid Microcapsule Carriers

    Directory of Open Access Journals (Sweden)

    Mike McShane

    2008-09-01

    Full Text Available Fluorescence-based sensing systems offer potential for noninvasive monitoring with implantable devices, but require carrier technologies that provide suitable immobilization, accessibility, and biocompatibility. Recent developments towards this goal include a competitive binding assay for glucose that has been encapsulated in semipermeable microcapsule carriers. This paper describes an extension of this work to increase the applicability to in vivo monitoring, wherein two significant developments are described: (1 a near-infrared resonance energy transfer system for transducing glucose concentration, and (2 novel hybrid organic-inorganic crosslinked microcapsules as carriers. The quenching-based assay is a competitive binding (CB system based on apo-glucose oxidase (AG as the receptor and dextran as the competitive ligand. The encapsulated quencher-labeled dextran and near infrared donor-labeled glucose receptor showed a stable and reversible response with tunable sensitivity of 1–5%/mM over the physiological range, making these transducers attractive for continuous monitoring for biomedical applications.

  2. Structure and properties of nano-confined poly(3-hexylthiophene) in nano-array/polymer hybrid ordered-bulk heterojunction solar cells.

    Science.gov (United States)

    Foong, Thelese Ru Bao; Chan, Khai Leok; Hu, Xiao

    2012-01-21

    The ordered-bulk heterojunction (BHJ) photovoltaic device comprising a semiconducting donor polymer incorporated into pristine/unmodified vertically aligned arrays of metal oxide acceptor nanotubes/nanorods is widely perceived as being structurally ideal for energy conversion but the power conversion efficiencies of such devices remain relatively low (in the order of η = 0.6%) when compared with bilayer or non-ordered bulk heterojunction systems. We explain the incongruity by investigating the morphology and microstructure of regio-regular poly(3-hexyl thiophene) (P3HT) infiltrated and confined within the cavities of TiO(2) nanotube arrays. A series of TiO(2) nanotube arrays with different nanotube diameters and inter-nanotube spacings are fabricated by the liquid-phase atomic layer deposition (LALD) technique, and P3HT is infiltrated into the array cavities via a vacuum-annealing technique. X-Ray diffraction studies reveal that the P3HT chains in both nano-confined and non-confined (i.e. planar film) environments are well-aligned and oriented edge-on with respect to the underlying substrate. Up to 2.5-fold improvement in the incident-photon-to-converted-electron efficiency (IPCE) is observed in ordered-BHJ structures over benchmark planar devices which we attribute to the increase in interfacial area resulting from the use of the nanostructures. However, the large effective surface area conferred by the nano-arrays (up to 9.5 times that of the planar system) suggests that much higher efficiencies could be harnessed. Our study shows that the morphology and orientation of the infiltrated polymer play a critical role in the charge transport of the device, and suggests that better understanding and control of polymer morphology under nano-confinement in the nano-array will be the key to fully reaping the promised benefit of ordered-BHJ devices.

  3. Biological sensing using hybridization phase of plasmonic resonances with photonic lattice modes in arrays of gold nanoantennas

    Science.gov (United States)

    Gutha, Rithvik R.; Sadeghi, Seyed M.; Sharp, Christina; Wing, Waylin J.

    2017-09-01

    We study biological sensing using the hybridization phase of localized surface plasmon resonances (LSPRs) with diffraction modes (photonic lattice modes) in arrays of gold nanoantennas. We map the degree of the hybridization process using an embedding dielectric material (Si), identifying the critical thicknesses wherein the optical responses of the arrays are mainly governed by pure LSPRs (insignificant hybridization), Fano-type coupling of LSPRs with diffraction orders (hybridization state), and their intermediate state (hybridization phase). The results show that hybridization phase can occur with slight change in the refractive index (RI), leading to sudden reduction of the linewidth of the main spectral feature of the arrays by about one order of magnitude while it is shifted nearly 140 nm. These processes, which offer significant improvement in RI sensitivity and figure of merit, are utilized to detect monolayers of biological molecules and streptavidin-conjugated semiconductor quantum dots with sensitivities far higher than pure LSPRs. We further explore how these sensors can be used based on the uncoupled LSPRs by changing the polarization of the incident light.

  4. Double Resonant Topology for 72V Battery Charger used in a Hybrid Electric Locomotive - Study and Experimental Validation

    OpenAIRE

    BUTTERBACH, S; DE-BERNARDINIS, A; Lallemand, R; Coquery, G.; JEUNESSE, A; EVAIN, Y; AUBIN, PH

    2010-01-01

    This work deals with the study, adaptation and experimental validation of a 9kW lead-acid battery charger used to feed the 72VDC bus inside the hybrid electric locomotive demonstrator in the frame of the French research project PLATHEE. The topology of the charger is based on a high frequency double resonant series-parallel circuit which allows soft switching, losses minimization, reduction of passive component weight and facilitates system integration. Specific charging and floating modes we...

  5. Anticrossing double Fano resonances generated in metallic/dielectric hybrid nanostructures using nonradiative anapole modes for enhanced nonlinear optical effects.

    Science.gov (United States)

    Zhai, Wu-Chao; Qiao, Tie-Zhu; Cai, Dong-Jin; Wang, Wen-Jie; Chen, Jing-Dong; Chen, Zhi-Hui; Liu, Shao-Ding

    2016-11-28

    Third-harmonic generation with metallic or dielectric nanoparticles often suffer from, respectively, small modal volumes and weak near-field enhancements. This study propose and demonstrate that a metallic/dielectric hybrid nanostructure composed of a silver double rectangular nanoring and a silicon square nanoplate can be used to overcome these obstacles for enhanced third-harmonic generation. It is shown that the nonradiative anapole mode of the Si plate can be used as a localized source to excite the dark subradiant octupole mode of the Ag ring, and the mode hybridization leads to the formation of an antibonding and a bonding subradiant collective mode, thereby forming anticrossing double Fano resonances. With the strong coupling between individual particles and the effectively suppressed radiative losses of the Fano resonances, several strong hot spots are generated around the Ag ring due to the excitation of the octupole mode, and electromagnetic fields within the Si plate are also strongly amplified, making it possible to confine more incident energy inside the dielectric nanoparticle. Calculation results reveal that the confined energy inside the Si plate and the Ag ring for the hybrid structures can be about, respectively, more than three times and four orders stronger than that of the corresponding isolated nanoparticles, which makes the designed hybrid nanostructure a promising platform for enhanced third-harmonic generation.

  6. Fabrication of Al/Graphite/Al2O3 Surface Hybrid Nano Composite by Friction Stir Processing and Investigating The Wear and Microstructural Properties of The Composite

    Directory of Open Access Journals (Sweden)

    A. Mostafapour

    2012-10-01

    Full Text Available Friction stir processing was applied for fabricating an aluminum alloy based hybrid nano composite reinforced with nano sized Al2O3 and micro sized graphite particles. A mixture of Al2O3 and graphite particles was packed into a groove with 1 mm width and 4.5 mm depth, which had been cut in 5083 aluminum plate of 10 mm thick. Packed groove was subjected to friction stir processing in order to implement powder mixture into the aluminum alloy matrix. Microstructural properties were investigated by means of optical microscopy and scanning electron microscopy (SEM. It was found that reinforcement particle mixture was distributed uniformly in nugget zone. Wear resistance of composite was measured by dry sliding wear test. As a result, hybrid composite revealed significant reduction in wear rate in comparison with Al/AL2O3 composite produced by friction stir processing. Worn surface of the wear test samples were examined by SEM in order to determine wear mechanism.

  7. Conducting polymers and hybrid nano-materials for electrochemical storage; Polymeres conducteurs electroniques et nanomateriaux hybrides pour le stockage de l'energie

    Energy Technology Data Exchange (ETDEWEB)

    Mallouki, M.

    2006-02-15

    In this work, we report first on the preparation of nano-structures based on poly-pyrrole and iron oxide nano-particles by oxidative polymerisation of pyrrole in colloidal solution of Fe{sub 2}O{sub 3}. The conductivity and the morphology of nano-composites were studied and related to the doping agent role and the weight ratio (Fe{sub 2}O{sub 3}/PPy). The specific capacity measurement on the composite electrode (based on the nano-composite, acetylene black and binders) indicate a significant enhancement of charge storage for nano-composites compared to pure poly-pyrrole. Then, we investigated the synthesis and characterisation of composite electrode based on poly 3-methyl-thiophene (PMeT), which depend on different methods of preparation, electrolyte and doping potential. Finally, a room temperature ionic liquid (RTIL) such as imidazolium tri-fluoro-methane-sulfonimide (EMITFSI), was used and seem to be a promising electrolyte since it increases further the capacity with a high stability during charge-discharge processes. (author)

  8. Resonant excitation of precursor molecules in improving the particle crystallinity, growth rate and optical limiting performance of carbon nano-onions

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Y; Zhou, Y S; Park, J B; Wang, H; He, X N; Lu, Y F [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0511 (United States); Luo, H F; Jiang, L, E-mail: ylu2@unl.edu [Department of Mechanical and Automation Engineering, Beijing Institute of Technology, Beijing 10008 (China)

    2011-04-22

    A catalyst-free and highly efficient synthetic method for growing carbon nano-onions (CNOs) in open air has been developed through the laser resonant excitation of a precursor molecule, ethylene, in a combustion process. Highly concentric CNO particles with improved crystallinity were obtained at a laser wavelength of 10.532 {mu}m through the resonant excitation of the CH{sub 2} wagging mode of the ethylene molecules. A higher growth rate up to 2.1 g h{sup -1} was obtained, compared with that without a laser (1.3 g h{sup -1}). Formation of the CNOs with ordered graphitic shells is ascribed to the decomposition of polycyclic aromatic hydrocarbons (PAHs) into C{sub 2} species. The optical limiting performances of the CNOs grown by the combustion processes were investigated. CNOs grown at 10.532 {mu}m laser excitation demonstrated improved optical limiting properties due to the improved crystallinity.

  9. Magnetic solid phase extraction of gemfibrozil from human serum and pharmaceutical wastewater samples utilizing a β-cyclodextrin grafted graphene oxide-magnetite nano-hybrid.

    Science.gov (United States)

    Abdolmohammad-Zadeh, Hossein; Talleb, Zeynab

    2015-03-01

    A magnetic solid phase extraction method based on β-cyclodextrin (β-CD) grafted graphene oxide (GO)/magnetite (Fe3O4) nano-hybrid as an innovative adsorbent was developed for the separation and pre-concentration of gemfibrozil prior to its determination by spectrofluorometry. The as-prepared β-CD/GO/Fe3O4 nano-hybrid possesses the magnetism property of Fe3O4 nano-particles that makes it easily manipulated by an external magnetic field. On the other hand, the surface modification of GO by β-CD leads to selective separation of the target analyte from sample matrices. The structure and morphology of the synthesized adsorbent were characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The experimental factors affecting the extraction/pre-concentration and determination of the analyte were investigated and optimized. Under the optimized experimental conditions, the calibration graph was linear in the range between 10 and 5000 pg mL(-1) with a correlation coefficient of 0.9989. The limit of detection and enrichment factor for gemfibrozil were 3 pg mL(-1) and 100, respectively. The maximum sorption capacity of the adsorbent for gemfibrozil was 49.8 mg g(-1). The method was successfully applied to monitoring gemfibrozil in human serum and pharmaceutical wastewaters samples with recoveries in the range of 96.0-104.0% for the spiked samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. As-grown graphene/copper nanoparticles hybrid nanostructures for enhanced intensity and stability of surface plasmon resonance

    Science.gov (United States)

    Li, Yun-Fei; Dong, Feng-Xi; Chen, Yang; Zhang, Xu-Lin; Wang, Lei; Bi, Yan-Gang; Tian, Zhen-Nan; Liu, Yue-Feng; Feng, Jing; Sun, Hong-Bo

    2016-11-01

    The transfer-free fabrication of the high quality graphene on the metallic nanostructures, which is highly desirable for device applications, remains a challenge. Here, we develop the transfer-free method by direct chemical vapor deposition of the graphene layers on copper (Cu) nanoparticles (NPs) to realize the hybrid nanostructures. The graphene as-grown on the Cu NPs permits full electric contact and strong interactions, which results in a strong localization of the field at the graphene/copper interface. An enhanced intensity of the localized surface plasmon resonances (LSPRs) supported by the hybrid nanostructures can be obtained, which induces a much enhanced fluorescent intensity from the dye coated hybrid nanostructures. Moreover, the graphene sheets covering completely and uniformly on the Cu NPs act as a passivation layer to protect the underlying metal surface from air oxidation. As a result, the stability of the LSPRs for the hybrid nanostructures is much enhanced compared to that of the bare Cu NPs. The transfer-free hybrid nanostructures with enhanced intensity and stability of the LSPRs will enable their much broader applications in photonics and optoelectronics.

  11. Nano-sized Mo- and Nb-doped TiO2 as anode materials for high energy and high power hybrid Li-ion capacitors

    Science.gov (United States)

    Bauer, Dustin; Roberts, Alexander J.; Matsumi, Noriyoshi; Darr, Jawwad A.

    2017-05-01

    Nano-sized Mo-doped titania (Mo0.1Ti0.9O2) and Nb-doped titania (Nb0.25Ti0.75O2) were directly synthesized via a continuous hydrothermal flow synthesis process. Materials characterization was conducted using physical techniques such as transmission electron microscopy, powder x-ray diffraction, x-ray photoelectron spectroscopy, Brunauer-Emmett-Teller specific surface area measurements and energy dispersive x-ray spectroscopy. Hybrid Li-ion supercapacitors were made with either a Mo-doped or Nb-doped TiO2 negative electrode material and an activated carbon (AC) positive electrode. Cells were evaluated using electrochemical testing (cyclic voltammetry, constant charge discharge cycling). The hybrid Li-ion capacitors showed good energy densities at moderate power densities. When cycled in the potential window 0.5-3.0 V, the Mo0.1Ti0.9O2/AC hybrid supercapacitor showed the highest energy densities of 51 Wh kg-1 at a power of 180 W kg-1 with energy densities rapidly declining with increasing applied specific current. In comparison, the Nb0.25Ti0.75O2/AC hybrid supercapacitor maintained its energy density of 45 Wh kg-1 at 180 W kg-1 better, showing 36 Wh g-1 at 3200 W kg-1, which is a very promising mix of high energy and power densities. Reducing the voltage window to the range 1.0-3.0 V led to an increase in power density, with the Mo0.1Ti0.9O2/AC hybrid supercapacitor giving energy densities of 12 Wh kg-1 and 2.5 Wh kg-1 at power densities of 6700 W kg-1 and 14 000 W kg-1, respectively.

  12. 700-W diffusion-cooled large-area 40.68-MHz excited CO2 laser employing split-wave hybrid confocal resonator

    Science.gov (United States)

    Vitruk, Peter; Schemmer, James; Byron, Stan

    1998-09-01

    A novel non-waveguide, non-free-space CO2 laser resonator cavity, referred to as the split-wave hybrid (SWH) resonator, is described. Traditional resonator mirrors combined with two specially designed light reflecting electrode walls, which enclose the active medium, form the SWH resonator cavity. Light reflecting walls in the split-wave resonator act as wave-front-splitting mirrors in an interferometer, similar to a Fresnel double mirror or Lloyd mirror interferometer. Wave- front of the intra-cavity laser beam is significantly tilted with respect to the resonator walls, which facilitates lowest order mode selection in this resonator. Additionally, electrode wall surfaces contain discontinuities, which further enhances non-waveguide mode discrimination in the SWH resonator.

  13. Four-year clinical evaluation of Class II nano-hybrid resin composite restorations bonded with a one-step self-etch and a two-step etch-and-rinse adhesive

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2011-01-01

    The objective of this prospective clinical trial was to evaluate the 4-year clinical performance of an ormocer-based nano-hybrid resin composite (Ceram X; Dentsply/DeTrey) in Class II restorations placed with a one-step self-etch (Xeno III; Dentsply/DeTrey) and two-step etch-and-rinse adhesive...

  14. Interfacial transduction of nucleic acid hybridization using immobilized quantum dots as donors in fluorescence resonance energy transfer.

    Science.gov (United States)

    Algar, W Russ; Krull, Ulrich J

    2009-01-06

    Fluorescence resonance energy transfer (FRET) using immobilized quantum dots (QDs) as energy donors was explored as a transduction method for the detection of nucleic acid hybridization at an interface. This research was motivated by the success of the QD-FRET-based transduction of nucleic acid hybridization in solution-phase assays. This new work represents a fundamental step toward the assembly of a biosensor, where immobilization of the selective chemistry on a surface is desired. After immobilizing QD-probe oligonucleotide conjugates on optical fibers, a demonstration of the retention of selectivity was achieved by the introduction of acceptor (Cy3)-labeled single-stranded target oligonucleotides. Hybridization generated the proximity required for FRET, and the resulting fluorescence spectra provided an analytical signal proportional to the amount of target. This research provides an important framework for the future development of nucleic acid biosensors based on QDs and FRET. The most important findings of this work are that (1) a QD-FRET solid-phase hybridization assay is viable and (2) a passivating layer of denatured bovine serum albumin alleviates nonspecific adsorption, ultimately resulting in (3) the potential for a reusable assay format and mismatch discrimination. In this, the first incarnation of a solid-phase QD-FRET hybridization assay, the limit of detection was found to be 5 nM, and the dynamic range was almost 2 orders of magnitude. Selective discrimination of the target was shown using a three-base-pairs mismatch from a fully complementary sequence. Despite a gradual loss of signal, reuse of the optical fibers over multiple cycles of hybridization and dehybridization was possible. Directions for further improvement of the analytical performance by optimizing the design of the QD-probe oligonucleotide interface are identified.

  15. Hybrid optical antennas with photonic resistors.

    Science.gov (United States)

    Butakov, N A; Schuller, J A

    2015-11-16

    Hybrid optical antennas, comprising active materials placed in the gaps of plasmonic split-ring-resonators and nano-dimers, have been the subject of numerous recent investigations. Engineered coupling between the two plasmonic resonators is achieved by modulating the active material, enabling control over the near- and far-field electromagnetic properties. Here, using electromagnetics calculations, we study the evolving optical response of a hybrid metal-semiconductor-metal nanorod antenna as the semiconductor free charge carrier density is continuously varied. In particular, we demonstrate qualitatively new behavior arising from epsilon-near-zero properties in intermediately doped semiconductors. In agreement with optical nano-circuit theory, we show that in the epsilon-near-zero regime such a load acts as an ideal optical resistor with an optimized damping response and strongly suppressed electromagnetic scattering. In periodic arrays, or metasurfaces, we then show how to use these effects to construct high-efficiency nanophotonic intensity modulators for dynamically shaping light.

  16. Parametric decay instability near the upper hybrid resonance in magnetically confined fusion plasmas

    DEFF Research Database (Denmark)

    Hansen, Søren Kjer; Nielsen, Stefan Kragh; Salewski, Mirko

    2017-01-01

    In this paper we investigate parametric decay of an electromagnetic pump wave into two electrostatic daughter waves, particularly an X-mode pump wave decaying into a warm upper hybrid wave (a limit of an electron Bernstein wave) and a warm lower hybrid wave. We describe the general theory...

  17. Enhanced optical second harmonic generation in hybrid polymer nanoassemblies based on coupled surface plasmon resonance of a gold nanoparticle array

    Science.gov (United States)

    Ishifuji, Miki; Mitsuishi, Masaya; Miyashita, Tokuji

    2006-07-01

    Effective utilization of coupled surface plasmon resonance from gold nanoparticles was demonstrated experimentally for optoelectronic applications based on second-order nonlinear optics. Hybrid polymer nanoassemblies were constructed by manipulating gold nanoparticle arrays with nonlinear optical active polymer nanosheets to investigate the second harmonic generation. The gold nanoparticle arrays were assembled on heterodeposited polymer nanosheets. The second harmonic light intensity was enhanced by a factor of 8. The observed enhancement was attributed to coupling of surface plasmons between two adjacent gold nanoparticles, thereby enhancing the surface electromagnetic field around the nanoparticles at the fundamental light wavelength (1064nm).

  18. An ultra-thin dual-band phase-gradient metasurface using hybrid resonant structures for backward RCS reduction

    Science.gov (United States)

    Cheng, Yongzhi; Wu, Chenjun; Ge, Chenchen; Yang, Jiaji; Pei, Xiaojun; Jia, Fan; Gong, Rongzhou

    2017-05-01

    We introduce and investigate, both experimentally and theoretically, a dual-band phase-gradient metasurface (PGM) to accurately facilitate dual-band beams deflection for electromagnetic waves. The designed PGM is composed of two kinds of split-ring resonators as the basic element of a super cell. These hybrid resonant structures can generate phase gradients at two distinct frequencies, which, in turn, generate appropriately artificial wave vectors that meet the requirements for anomalous reflection in terms of generalized Snell's law. Both simulations and experiments are consistent with the theoretical predictions. Further, this PGM can work at 8.9 and 11.4 GHz frequencies providing a phenomenon of anomalous reflection, which is useful for backward radar cross section reduction.

  19. Fabrication and characterization of high order filter based on resonance in hybrid multi-knots microfiber structure

    Science.gov (United States)

    Nodehi, S.; Mohammed, W. S.; Ahmad, H.; Harun, S. W.

    2016-04-01

    This work proposes a novel design of a hybrid microfiber resonator which can be used as a band-pass and band-stop filter in various applications such as fiber lasers. The structure comprises of two microfiber knot resonators with different sizes which are surrounded by a semi-loop structure with one input and two output ports. Utilization of the Vernier effect in the proposed structure showed an enhancement of the free spectral range (FSR). The finesse has increased by a factor of three compared to a single knot providing a sharper roll-off. The filter bandwidth is adjustable as a result of the manipulation of the coupling length and rings' radii. The performance of the device is explained theoretically using transfer matrix analysis.

  20. A Multi-Modal Control Using a Hybrid Pole-Placement-Integral Resonant Controller (PPIR) with Experimental Investigations

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Basu, Biswajit

    2011-01-01

    Control of multi-modal structural vibrations has been an important and challenging problem in flexible structural systems. This paper proposes a new vibration control algorithm for multi-modal structural control. The proposed algorithm combines a pole-placement controller with an integral resonant...... controller. The pole-placement controller is used to achieve a target equivalent modal viscous damping in the system and helps in the suppression of higher modes, which contribute to the vibration response of flexible structures. The integral resonant controller successfully reduces the low frequency...... vibrations e.g. caused by broad-band turbulent wind excitations. Hence, the proposed hybrid controller can effectively suppress complex multi-modal vibrations in flexible systems. Both numerical and experimental studies have been carried out to demonstrate the effectiveness of the proposed algorithm using...

  1. 纳米材料在杂化聚氨酯中的效应%Effect of nano-materials in hybrid polyurethanes

    Institute of Scientific and Technical Information of China (English)

    叶青萱

    2013-01-01

    近年UV固化水性聚氨酯(WPU)或聚氨酯丙烯酸酯(WPUA)纳米复合材料的特性受到众多研究者的关注,并进行了多项研究。采用的纳米材料包括SiO2、Al2O3、TiO2、ZnO、POSS、碳纳米管、碳纳米纤维等。重点综述了WPU和WPUA低聚物(预聚物)的制备、纳米材料的改性处理、WPU/纳米颗粒和WPUA/纳米颗粒杂化复合材料的制备以及所得制品的表征、性能等。%Recently,the chracteristics of UV-curable waterborne polyurethane (WPU) and waterborne polyurethane-acrylate (WPUA) nanocomposites have been attracted attention of some researchers,and many studies about them were carried out.The nano-materials used for these studies include SiO2,Al2O3,TiO2,ZnO,POSS,carbon nanotubes,carbon nanofibres,etc.The preparation of WPU and WPUA oligmers (prepolymers),the modifying of nano-materials,the preparation of WPU and WPUA/nano particle hybrid composites as well as the characterization and properties of formed products are reviewed emphatically.

  2. Fabrication of microfibrous and nano-/microfibrous scaffolds: melt and hybrid electrospinning and surface modification of poly(L-lactic acid) with plasticizer.

    Science.gov (United States)

    Yoon, Young Il; Park, Ko Eun; Lee, Seung Jin; Park, Won Ho

    2013-01-01

    Biodegradable poly(L-lactic acid) (PLA) fibrous scaffolds were prepared by electrospinning from a PLA melt containing poly(ethylene glycol) (PEG) as a plasticizer to obtain thinner fibers. The effects of PEG on the melt electrospinning of PLA were examined in terms of the melt viscosity and fiber diameter. Among the parameters, the content of PEG had a more significant effect on the average fiber diameter and its distribution than those of the spinning temperature. Furthermore, nano-/microfibrous silk fibroin (SF)/PLA and PLA/PLA composite scaffolds were fabricated by hybrid electrospinning, which involved a combination of solution electrospinning and melt electrospinning. The SF/PLA (20/80) scaffolds consisted of a randomly oriented structure of PLA microfibers (average fiber diameter = 8.9 µm) and SF nanofibers (average fiber diameter = 820 nm). The PLA nano-/microfiber (20/80) scaffolds were found to have similar pore parameters to the PLA microfiber scaffolds. The PLA scaffolds were treated with plasma in the presence of either oxygen or ammonia gas to modify the surface of the fibers. This approach of controlling the surface properties and diameter of fibers could be useful in the design and tailoring of novel scaffolds for tissue engineering.

  3. Fabrication of Microfibrous and Nano-/Microfibrous Scaffolds: Melt and Hybrid Electrospinning and Surface Modification of Poly(L-lactic acid with Plasticizer

    Directory of Open Access Journals (Sweden)

    Young Il Yoon

    2013-01-01

    Full Text Available Biodegradable poly(L-lactic acid (PLA fibrous scaffolds were prepared by electrospinning from a PLA melt containing poly(ethylene glycol (PEG as a plasticizer to obtain thinner fibers. The effects of PEG on the melt electrospinning of PLA were examined in terms of the melt viscosity and fiber diameter. Among the parameters, the content of PEG had a more significant effect on the average fiber diameter and its distribution than those of the spinning temperature. Furthermore, nano-/microfibrous silk fibroin (SF/PLA and PLA/PLA composite scaffolds were fabricated by hybrid electrospinning, which involved a combination of solution electrospinning and melt electrospinning. The SF/PLA (20/80 scaffolds consisted of a randomly oriented structure of PLA microfibers (average fiber diameter = 8.9 µm and SF nanofibers (average fiber diameter = 820 nm. The PLA nano-/microfiber (20/80 scaffolds were found to have similar pore parameters to the PLA microfiber scaffolds. The PLA scaffolds were treated with plasma in the presence of either oxygen or ammonia gas to modify the surface of the fibers. This approach of controlling the surface properties and diameter of fibers could be useful in the design and tailoring of novel scaffolds for tissue engineering.

  4. Omnidirectional color filters capitalizing on a nano-resonator of Ag-TiO2-Ag integrated with a phase compensating dielectric overlay.

    Science.gov (United States)

    Park, Chul-Soon; Shrestha, Vivek Raj; Lee, Sang-Shin; Kim, Eun-Soo; Choi, Duk-Yong

    2015-02-16

    We present a highly efficient omnidirectional color filter that takes advantage of an Ag-TiO2-Ag nano-resonator integrated with a phase-compensating TiO2 overlay. The dielectric overlay substantially improves the angular sensitivity by appropriately compensating for the phase pertaining to the structure and suppresses unwanted optical reflection so as to elevate the transmission efficiency. The filter is thoroughly designed, and it is analyzed in terms of its reflection, optical admittance, and phase shift, thereby highlighting the origin of the omnidirectional resonance leading to angle-invariant characteristics. The polarization dependence of the filter is explored, specifically with respect to the incident angle, by performing experiments as well as by providing the relevant theoretical explanation. We could succeed in demonstrating the omnidirectional resonance for the incident angles ranging to up to 70°, over which the center wavelength is shifted by below 3.5% and the peak transmission efficiency is slightly degraded from 69%. The proposed filters incorporate a simple multi-layered structure and are expected to be utilized as tri-color pixels for applications that include image sensors and display devices. These devices are expected to allow good scalability, not requiring complex lithographic processes.

  5. Omnidirectional color filters capitalizing on a nano-resonator of Ag-TiO2-Ag integrated with a phase compensating dielectric overlay

    Science.gov (United States)

    Park, Chul-Soon; Shrestha, Vivek Raj; Lee, Sang-Shin; Kim, Eun-Soo; Choi, Duk-Yong

    2015-01-01

    We present a highly efficient omnidirectional color filter that takes advantage of an Ag-TiO2-Ag nano-resonator integrated with a phase-compensating TiO2 overlay. The dielectric overlay substantially improves the angular sensitivity by appropriately compensating for the phase pertaining to the structure and suppresses unwanted optical reflection so as to elevate the transmission efficiency. The filter is thoroughly designed, and it is analyzed in terms of its reflection, optical admittance, and phase shift, thereby highlighting the origin of the omnidirectional resonance leading to angle-invariant characteristics. The polarization dependence of the filter is explored, specifically with respect to the incident angle, by performing experiments as well as by providing the relevant theoretical explanation. We could succeed in demonstrating the omnidirectional resonance for the incident angles ranging to up to 70°, over which the center wavelength is shifted by below 3.5% and the peak transmission efficiency is slightly degraded from 69%. The proposed filters incorporate a simple multi-layered structure and are expected to be utilized as tri-color pixels for applications that include image sensors and display devices. These devices are expected to allow good scalability, not requiring complex lithographic processes. PMID:25683162

  6. Non-enzymatic electrochemical biosensor based on Pt NPs/RGO-CS-Fc nano-hybrids for the detection of hydrogen peroxide in living cells.

    Science.gov (United States)

    Bai, Zhihao; Li, Guiyin; Liang, Jingtao; Su, Jing; Zhang, Yue; Chen, Huaizhou; Huang, Yong; Sui, Weiguo; Zhao, Yongxiang

    2016-08-15

    A highly sensitive non-enzymatic electrochemical sensor based on platinum nanoparticles/reduced graphene oxide-chitosan-ferrocene carboxylic acid nano-hybrids (Pt NPs/RGO-CS-Fc biosensor) was developed for the measurement of hydrogen peroxide (H2O2). The RGO-CS-Fc nano-hybrids was prepared and characterized by UV-vis spectrum, Fourier transform infrared spectroscopy, transmission electron microscopy, Raman spectrometer and electrochemical impedance spectroscopy. Under optimal experimental conditions, the Pt NPs/RGO-CS-Fc biosensor showed outstanding catalytic activity toward H2O2 reduction. The current response of the biosensor presented a linear relationship with H2O2 concentration from 2.0×10(-8)M to 3.0×10(-6)M with a correlation coefficient of R(2)=0.9968 and with logarithm of H2O2 concentration from 6.0×10(-6)M to 1.0×10(-2)M with a correlation coefficient of R(2)=0.9887, the low detection limit of 20nM was obtained at the signal/noise (S/N) ratio of 3. Moreover, the Pt NPs/RGO-CS-Fc biosensor exhibited excellent anti-interference capability and reproducibility for the detection of H2O2. The biosensor was also successfully applied for the detection of H2O2 from living cells containing normal and cancer cells. All these results prove that the Pt NPs/RGO-CS-Fc biosensor has the potential application in clinical diagnostics to evaluate oxidative stress of different living cells.

  7. Selective Amplification of Narrow Resonance Formed in Transmission Spectrum of Rb Nano-Cell in Magnetic Field

    Science.gov (United States)

    Sargsyan, A.; Hakhumyan, G.; Mirzoyan, R.; Papoyan, A.; Sarkisyan, D.; Leroy, C.; Pashayan-Leroy, Y.

    Recently it was shown that "λ-Zeeman Technique" (λ-ZT) is a convenient tool to study individual transitions between the Zeeman sublevels of hyperfine levels in an external magnetic field. λ-ZT is based on resonant transmission spectrum of nanometric thin cell (NTC) of thickness L= λ, where λ is the resonant wavelength 794 nm for Rb D1 line. Narrow velocity selective optical pumping (VSOP) resonances in the transmission spectrum of the NTC are split into several components in a magnetic field. Examination of VSOP resonances allows one to identify and investigate an atomic transition in the range of magnetic fields 10 - 5000 G. Here we present a new method for selective addressing of VSOP resonance amplification (more than 10 times).

  8. Dipole nano-laser

    Energy Technology Data Exchange (ETDEWEB)

    Protsenko, I E; Uskov, A V; Krotova, K E [Lebedev Physical Institute, Leninsky prospect 53, Moscow (Russian Federation); O' Reilly, E P [Tyndall National Institute, ' Lee Maltings' , Prospect Row, Cork (Ireland)], E-mail: protsen@sci.lebedev.ru, E-mail: protsenk@gmail.com

    2008-03-15

    Theoretically predicted 'dipole lasing', i.e., spontaneous excitation of coherent metal nano-particle dipole oscillations through interaction with a quantum-dot two-level system subject to population inversion is demonstrated. Equations for dipole lasing are the same as equations for ordinary laser, where the dipole momentum of nano-particle stands for the electromagnetic field cavity mode. Dipole lasing frequency corresponds to the localized plasmon resonance of the nano-particle. Dipole momentum of nano-particle leads to coherent dipole radiation. Optical cavity is not necessary, the size of the dipole laser can be smaller than the optical wavelength, i.e. it is dipole nano-laser. Threshold conditions and optical bistability in dipole nano-lasers are considered.

  9. Numerical tailoring of linear response from plasmonic nano-resonators grown on a layer of polystyrene spheres

    Energy Technology Data Exchange (ETDEWEB)

    Benedetti, A., E-mail: alessio.benedetti@uniroma1.it; Belardini, A.; Veroli, A.; Centini, M.; Sibilia, C. [Sapienza Università di Roma, Via A. Scarpa 14, I-00161 Roma (Italy)

    2014-10-28

    We developed a geometrical method to reproduce the morphology of hybrid structures composed by self-ordered dielectric nanospheres covered by anisotropic plasmonic structures. Numerical analysis allowed to investigate the optical response of the considered system, and to identify the relevant parameters to achieve efficient and versatile light manipulation. In particular, we show that the overall structure, acting as a hybrid plasmonic-photonics meta-surface, can be engineered in order to maximize its linear and circular dichroic behavior at optical frequencies.

  10. Native and induced triplet nitrogen-vacancy centers in nano- and micro-diamonds: Half-field electron paramagnetic resonance fingerprint

    Science.gov (United States)

    Shames, A. I.; Osipov, V. Yu.; von Bardeleben, H.-J.; Boudou, J.-P.; Treussart, F.; Vul', A. Ya.

    2014-02-01

    Multiple frequency electron paramagnetic resonance (EPR) study of small (4-25 nm) nanodiamonds obtained by various dynamic synthesis techniques reveals systematic presence in the half-field (HF) region a distinctive doublet fingerprint consisting of resolved gHF1 = 4.26 and gHF2 = 4.00 signals. This feature is attributed to "forbidden" ΔMS = 2 transitions in EPR spectra of two native paramagnetic centers of triplet (S = 1) origin designated as TR1 and TR2, characterized by zero field splitting values D1 = 0.0950 ± 0.002 cm-1 and D2 = 0.030 ± 0.005 cm-1. Nanodiamonds of ˜50 nm particle size, obtained by crushing of Ib type nitrogen rich synthetic diamonds, show only HF TR2 signal whereas the same sample undergone high energy (20 MeV) electron irradiation and thermal annealing demonstrates rise of HF TR1 signal. The same HF TR1 signals appear in the process of fabrication of fluorescent nanodiamonds from micron-size synthetic diamond precursors. Results obtained allow unambiguous attribution of the half-field TR1 EPR signals with gHF1 = 4.26, observed in nano- and micron-diamond powders, to triplet negatively charged nitrogen-vacancy centers. These signals are proposed as reliable and convenient fingerprints in both qualitative and quantitative study of fluorescent nano- and micron-diamonds.

  11. ORNL TNS program: microwave start-up of tokamak plasmas near electron cyclotron and upper hybrid resonances

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Y. K.M.; Borowski, S. K.

    1977-12-01

    The scenario of toroidal plasma start-up with microwave initiation and heating near the electron cyclotron frequency is suggested and examined here. We assume microwave irradiation from the high field side and an anomalously large absorption of the extraordinary waves near the upper hybrid resonance. The dominant electron energy losses are assumed to be due to magnetic field curvature and parallel drifts, ionization of neutrals, cooling by ions, and radiation by low Z impurities. It is shown by particle and energy balance considerations that electron temperatures around 250 eV and densities of 10/sup 12/ to 10/sup 13/ cm/sup -3/ can be maintained, at least in a narrow region near the upper hybrid resonance, with modest microwave powers in the Impurity Study Experiment (ISX) (120 kW at 28 GHz) and The Next Step (TNS) (0.57 MW at 120 GHz). The loop voltages required for start-up from these initial plasmas are also estimated. It is shown that the loop voltage can be reduced by a factor of five to ten from that for unassisted start-up without an increase in the resistive loss in volt-seconds. If this reduction in loop voltage is verified in the ISX experiments, substantial savings in the cost of power supplies for the ohmic heating (OH) and equilibrium field (EF) coils can be realized in future large tokamaks.

  12. Synthesis of silver embedded poly(o-anisidine molybdophosphate nano hybrid cation-exchanger applicable for membrane electrode.

    Directory of Open Access Journals (Sweden)

    Anish Khan

    Full Text Available Poly(o-anisidine molybdophosphate was expediently obtained by sol-gel mixing of Poly(o-anisidine into the inorganic matrices of molybdophosphate, which was allowed to react with silver nitrate to the formation of poly(o-anisidine molybdophosphate embedded silver nano composite. The composite was characterized by Fourier Transform Infrared Spectroscopy, X-ray powder diffraction, UV-Vis Spectrophotometry, Fluorescence Spectroscopy, Scanning Electron Microscopy/Energy-dispersive X-ray Spectroscopy and Thermogravimertic Analysis. Ion exchange capacity and distribution studies were carried out to understand the ion-exchange capabilities of the nano composite. On the basis of highest distribution studies, this nano composite cation exchanger was used as preparation of heavy metal ion selective membrane. Membrane was characterized for its performance as porosity and swelling later on was used for the preparation of membrane electrode for Hg(II, having better linear range, wide working pH range (2-4.5 with fast response in the real environment.

  13. Three-dimensional culture and interaction of cancer cells and dendritic cells in an electrospun nano-submicron hybrid fibrous scaffold

    Directory of Open Access Journals (Sweden)

    Kim TE

    2016-03-01

    Full Text Available Tae-Eon Kim,1–3,* Chang Gun Kim,1–3,* Jin Soo Kim,4 Songwan Jin,4 Sik Yoon,5 Hae-Rahn Bae,6 Jeong-Hwa Kim,7,8 Young Hun Jeong,7,8 Jong-Young Kwak1–3 1Department of Pharmacology, School of Medicine, 2Department of Biomedical Sciences, The Graduate School, Ajou University, Suwon, South Korea; 3Immune Network Pioneer Research Center, Ajou University Medical Center, Suwon, South Korea; 4Department of Mechanical Engineering, Korea Polytechnic University, Gyeonggi, South Korea; 5Department of Anatomy, School of Medicine, Pusan National University, Yangsan, South Korea; 6Department of Physiology, College of Medicine, Dong-A University, Busan, South Korea; 7School of Mechanical Engineering, 8Department of Mechanical Engineering, Graduate School, Kyungpook National University, Daegu, South Korea *These authors contributed equally to this work Abstract: An artificial three-dimensional (3D culture system that mimics the tumor microenvironment in vitro is an essential tool for investigating the cross-talk between immune and cancer cells in tumors. In this study, we developed a 3D culture system using an electrospun poly(ε-caprolactone (PCL nanofibrous scaffold (NFS. A hybrid NFS containing an uninterrupted network of nano- and submicron-scale fibers (400 nm to 2 µm was generated by deposition onto a stainless steel mesh instead of an aluminum plate. The hybrid NFS contained multiplanar pores in a 3D structure. Surface-seeded mouse CT26 colon cancer cells and bone marrow-derived dendritic cells (BM-DCs were able to infiltrate the hybrid NFS within several hours. BM-DCs cultured on PCL nanofibers showed a baseline inactive form, and lipopolysaccharide (LPS-activated BM-DCs showed increased expression of CD86 and major histocompatibility complex Class II. Actin and phosphorylated FAK were enriched where unstimulated and LPS-stimulated BM-DCs contacted the fibers in the 3D hybrid NFS. When BM-DCs were cocultured with mitoxantrone-treated CT26 cells in

  14. Graphene oxide-gold nanoparticles hybrids-based surface plasmon resonance for sensitive detection of microRNA.

    Science.gov (United States)

    Wang, Qing; Li, Qing; Yang, Xiaohai; Wang, Kemin; Du, Shasha; Zhang, Hua; Nie, Yajie

    2016-03-15

    In this study, a simple and sensitive surface plasmon resonance (SPR) biosensor for miRNA detection was developed using graphene oxide-gold nanoparticles (GO-AuNPs) hybrids as signal amplification element. Taking advantage of the GO-AuNPs hybrids and their enhanced performance in SPR biosensors, the detection of miRNA was carried out in only two steps. Firstly, the thiolated capture DNA probe with a short complete complementary sequence was immobilized on the Au film surface to recognize the part sequence of target miRNA. Subsequently, the assistant DNA-linked GO-AuNPs hybrids were employed to bind the other section of the target. It was found that the developed SPR biosensor was able to achieve a detection limit as low as 1 fM. Moreover, the method showed excellent ability to discriminate differences among miRNA-200 family members. Notably, human miRNA from cancer cells could also be detected, and the results were in excellent agreement with the ones obtained using qRT-PCR. On the basis of these findings, we believe that this method has great potential for quantitative detection of miRNA in biomedical research and early clinical diagnostics.

  15. Nucleic Acid Sandwich Hybridization Assay with Quantum Dot-Induced Fluorescence Resonance Energy Transfer for Pathogen Detection

    Directory of Open Access Journals (Sweden)

    Cheng-Chung Chou

    2012-12-01

    Full Text Available This paper reports a nucleic acid sandwich hybridization assay with a quantum dot (QD-induced fluorescence resonance energy transfer (FRET reporter system. Two label-free hemagglutinin H5 sequences (60-mer DNA and 630-nt cDNA fragment of avian influenza viruses were used as the targets in this work. Two oligonucleotides (16 mers and 18 mers that specifically recognize two separate but neighboring regions of the H5 sequences were served as the capturing and reporter probes, respectively. The capturing probe was conjugated to QD655 (donor in a molar ratio of 10:1 (probe-to-QD, and the reporter probe was labeled with Alexa Fluor 660 dye (acceptor during synthesis. The sandwich hybridization assay was done in a 20 μL transparent, adhesive frame-confined microchamber on a disposable, temperature-adjustable indium tin oxide (ITO glass slide. The FRET signal in response to the sandwich hybridization was monitored by a homemade optical sensor comprising a single 400 nm UV light-emitting diode (LED, optical fibers, and a miniature 16-bit spectrophotometer. The target with a concentration ranging from 0.5 nM to 1 μM was successfully correlated with both QD emission decrease at 653 nm and dye emission increase at 690 nm. To sum up, this work is beneficial for developing a portable QD-based nucleic acid sensor for on-site pathogen detection.

  16. Characterization of IRA/IRB hybrid insulin receptors using bioluminescence resonance energy transfer.

    Science.gov (United States)

    Blanquart, Christophe; Achi, Josepha; Issad, Tarik

    2008-10-01

    The insulin receptor (IR) is composed of two alpha-chains that bind ligands and two beta-chains that possess an intracellular tyrosine kinase activity. The IR is expressed in cells as two isoforms containing or not exon 11 (IRB and IRA, respectively). Several mRNA studies have demonstrated that the two isoforms are co-expressed in different tissues and in several cancer cells. IRA/IRB hybrid receptors, constituting of an alphabeta-chain from IRA and an alphabeta-chain from IRB, are likely to occur in cells co-expressing both isoforms, but their study has been hampered by the lack of specific tools. In previous work, we used BRET to study IR and IGF1R homodimers and heterodimers. Here, we have used BRET to characterize IRA/IRB hybrids. BRET saturation experiments showed that IRA/IRB hybrids are randomly formed in cells. Moreover, by co-transfecting HEK-293 cells with a luciferase-tagged kinase-dead version of one isoform and a wild-type untagged version of the other isoform, we showed that IRA/IRB hybrids can recruit, upon ligand stimulation, a YFP-tagged intracellular partner. Finally, using BRET, we have studied ligand-induced conformational changes within IRA/IRB hybrids. Dose-response experiments showed that hybrid receptors bind IGF-2 with the same affinity than IRA homodimers, whereas they bind IGF-1 with a lower affinity. Altogether, our data indicate that IRA/IRB hybrid receptors can form in cells co-expressing both IR isoforms, that they are capable of recruiting intracellular partners upon ligand stimulation, and that they have pharmacological properties more similar to those of IRA than those of IRB homodimers with regards to IGF-2.

  17. Resonances

    DEFF Research Database (Denmark)

    an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...... theoretical consciousness through historical narrative ‘in practice’, by discussing selected historical topics from Western cultural history, within the disciplines of history, literature, visual arts, musicology, archaeology, philosophy, and theology. The title Resonances indicates the overall perspective...

  18. Effect of micro-nano-hybrid structured hydroxyapatite bioceramics on osteogenic and cementogenic differentiation of human periodontal ligament stem cell via Wnt signaling pathway.

    Science.gov (United States)

    Mao, Lixia; Liu, Jiaqiang; Zhao, Jinglei; Chang, Jiang; Xia, Lunguo; Jiang, Lingyong; Wang, Xiuhui; Lin, Kaili; Fang, Bing

    2015-01-01

    The surface structure of bioceramic scaffolds is crucial for its bioactivity and osteoinductive ability, and in recent years, human periodontal ligament stem cells have been certified to possess high osteogenic and cementogenic differential ability. In the present study, hydroxyapatite (HA) bioceramics with micro-nano-hybrid surface (mnHA [the hybrid of nanorods and microrods]) were fabricated via hydrothermal reaction of the α-tricalcium phosphate granules as precursors in aqueous solution, and the effects of mnHA on the attachment, proliferation, osteogenic and cementogenic differentiations of human periodontal ligament stem cells as well as the related mechanisms were systematically investigated. The results showed that mnHA bioceramics could promote cell adhesion, proliferation, alkaline phosphatase (ALP) activity, and expression of osteogenic/cementogenic-related markers including runt-related transcription factor 2 (Runx2), ALP, osteocalcin (OCN), cementum attachment protein (CAP), and cementum protein (CEMP) as compared to the HA bioceramics with flat and dense surface. Moreover, mnHA bioceramics stimulated gene expression of low-density lipoprotein receptor-related protein 5 (LRP5) and β-catenin, which are the key genes of canonical Wnt signaling. Moreover, the stimulatory effect on ALP activity and osteogenic and cementogenic gene expression, including that of ALP, OCN, CAP, CEMP, and Runx2 of mnHA bioceramics could be repressed by canonical Wnt signaling inhibitor dickkopf1 (Dkk1). The results suggested that the HA bioceramics with mnHA could act as promising grafts for periodontal tissue regeneration.

  19. 2D/2D nano-hybrids of γ-MnO₂ on reduced graphene oxide for catalytic ozonation and coupling peroxymonosulfate activation.

    Science.gov (United States)

    Wang, Yuxian; Xie, Yongbing; Sun, Hongqi; Xiao, Jiadong; Cao, Hongbin; Wang, Shaobin

    2016-01-15

    Two-dimensional reduced graphene oxide (2D rGO) was employed as both a shape-directing medium and support to fabricate 2D γ-MnO2/2D rGO nano-hybrids (MnO2/rGO) via a facile hydrothermal route. For the first time, the 2D/2D hybrid materials were used for catalytic ozonation of 4-nitrophenol. The catalytic efficiency of MnO2/rGO was much higher than either MnO2 or rGO only, and rGO was suggested to play the role for promoting electron transfers. Quenching tests using tert-butanol, p-benzoquinone, and sodium azide suggested that the major radicals responsible for 4-nitrophenol degradation and mineralization are O2(-) and (1)O2, but not ·OH. Reusability tests demonstrated a high stability of the materials in catalytic ozonation with minor Mn leaching below 0.5 ppm. Degradation mechanism, reaction kinetics, reusability and a synergistic effect between catalytic ozonation and coupling peroxymonosulfate (PMS) activation were also discussed.

  20. High-Performance Wireless Ammonia Gas Sensors Based on Reduced Graphene Oxide and Nano-Silver Ink Hybrid Material Loaded on a Patch Antenna.

    Science.gov (United States)

    Wu, Bian; Zhang, Xingfei; Huang, Beiju; Zhao, Yutong; Cheng, Chuantong; Chen, Hongda

    2017-09-09

    Reduced graphene oxide (rGO) has been studied as a resistive ammonia gas sensor at room temperature. The sensitive hybrid material composed of rGO and nano-silver ink (Ag-ink) was loaded on a microstrip patch antenna to realize high-performance wireless ammonia sensors. The material was investigated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Firstly, interdigital electrodes (IDEs) printed on the polyethylene terephthalate (PET) by direct printing were employed to measure the variation of resistance of the sensitive material with the ammonia concentration. The results indicated the response of sensor varied from 4.25% to 14.7% under 15-200 ppm ammonia concentrations. Furthermore, the hybrid material was loaded on a microstrip patch antenna fabricated by a conventional printed circuit board (PCB) process, and a 10 MHz frequency shift of the sensor antenna could be observed for 200 ppm ammonia gas. Finally, the wireless sensing property of the sensor antenna was successfully tested using the same emitted antenna outside the gas chamber with a high gain of 5.48 dBi, and an increased reflection magnitude of the emitted antenna due to the frequency mismatch of the sensor antenna was observed. Therefore, wireless ammonia gas sensors loaded on a patch antenna have significant application prospects in the field of Internet of Things (IoTs).

  1. Tunable High Q Superconducting Microwave Resonator for Hybrid System with ^87Rb atoms

    Science.gov (United States)

    Kim, Zaeill; Voigt, K. D.; Lee, Jongmin; Hoffman, J. E.; Grover, J. A.; Ravets, S.; Zaretskey, V.; Palmer, B. S.; Hafezi, M.; Taylor, J. M.; Anderson, J. R.; Dragt, A. J.; Lobb, C. J.; Orozco, L. A.; Rolston, S. L.; Wellstood, F. C.

    2012-02-01

    We have developed a frequency tuning system for a ``lumped-element'' thin-film superconducting Al microwave resonator [1] on sapphire intended for coupling to hyperfine ground states of cold trapped ^87Rb atoms, which are separated by about fRb=6.83 GHz. At T=12 mK and on resonance at 6.81 GHz, the loaded quality factor was 120,000. By moving a carefully machined Al pin towards the inductor of the resonator using a piezo stage, we were able to tune the resonance frequency over a range of 35 MHz and within a few kHz of fRb. While measuring the power dependent response of the resonator at each tuned frequency, we observed anomalous decreases in the quality factor at several frequencies. These drops were more pronounced at lower power. We discuss our results, which suggest these resonances are attributable to discrete two-level systems.[4pt] [1] Z. Kim et al., AIP ADVANCES 1, 042107 (2011).

  2. Heavy-impurity resonance, hybridization, and phonon spectral functions in Fe1-xMxSi (M =Ir , Os )

    Science.gov (United States)

    Delaire, O.; Al-Qasir, I. I.; May, A. F.; Li, C. W.; Sales, B. C.; Niedziela, J. L.; Ma, J.; Matsuda, M.; Abernathy, D. L.; Berlijn, T.

    2015-03-01

    The vibrational behavior of heavy substitutional impurities (M = Ir,Os) in Fe1-xMxSi (x =0 ,0.02 ,0.04 ,0.1 ) was investigated with a combination of inelastic neutron scattering (INS), transport measurements, and first-principles simulations. Our INS measurements on single crystals mapped the four-dimensional dynamical structure factor, S (Q ,E ) , for several compositions and temperatures. Our results show that both Ir and Os impurities lead to the formation of a weakly dispersive resonance vibrational mode, in the energy range of the acoustic phonon dispersions of the FeSi host. We also show that Ir doping, which introduces free carriers, leads to softened interatomic force constants compared to doping with Os, which is isoelectronic to Fe. We analyze the phonon S (Q ,E ) from INS through a Green's-function model incorporating the phonon self-energy based on first-principles density functional theory simulations, and we study the disorder-induced lifetimes on large supercells. Calculations of the quasiparticle spectral functions in the doped system reveal the hybridization between the resonance and the acoustic phonon modes. Our results demonstrate a strong interaction of the host acoustic dispersions with the resonance mode, likely leading to the large observed suppression in lattice thermal conductivity.

  3. Generation of Localized Surface Plasmon Resonance Using Hybrid Au–Ag Nanoparticle Arrays as a Sensor of Polychlorinated Biphenyls Detection

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2016-08-01

    Full Text Available In this study, the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic nanoparticle arrays (PNAs were designed to investigate their extinction spectra of the localized surface plasmon resonances (LSPRs. First, their simulating extinction spectra were calculated by discrete dipole approximation (DDA numerical method by changing the media refractive index. Simulation results showed that as the media refractive index was changed from 1.0 to 1.2, the maximum peak intensity of LSPRs spectra had no apparent change and the wavelength to reveal the maximum peak intensity of LSPRs spectra was shifted lower value. Polystyrene (PS nanospheres with two differently arranged structures were used as the templates to deposit the hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate periodic PNAs by evaporation method. The hybrid Au–Ag hexagonal lattice of triangular and square lattice of quadrate PNAs were grown on single crystal silicon (c-Si substrates, and their measured extinction spectra were compared with the calculated results. Finally, the fabricated hexagonal lattices of triangular PNAs were investigated as a sensor of polychlorinated biphenyl solution (PCB-77 by observing the wavelength to reveal the maximum extinction efficiency (λmax. We show that the adhesion of β-cyclodextrins (SH-β-CD on the hybrid Au–Ag hexagonal lattice of triangular PNAs could be used to increase the variation of λmax. We also demonstrate that the adhesion of SH-β-CD increases the sensitivity and detection effect of PCB-77 in hexagonal lattice of triangular PNAs.

  4. New bioactive hybrid material of nano-hydroxyapatite based on N-carboxyethylchitosan for bone tissue engineering

    Science.gov (United States)

    Lu, Yan; Zhu, Aiping; Wang, Wanpeng; Shi, Hongchan

    2010-09-01

    N-carboxyethylchitosan/nano-hydroxyapatite (NCECS/HA) composite films were fabricated and their potential applications in guiding bone regeneration were investigated in terms of their in vitro cellular activity. Fourier ransform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to investigate the structure and composition of the composite film. Field Emission scanning electron microscopy (FESEM) revealed that HA nanoparticles were dispersed homogeneously in NCECS matrix. The composite film has sufficient mechanical properties for tissue engineering scaffold. The composite film was found to have better cartilage cell adhesion and growth than pure NCECS film.

  5. Hybrid composites of nano-sized zero valent iron and covalent organic polymers for groundwater contaminant degradation

    DEFF Research Database (Denmark)

    Mines, Paul D.; Byun, J.; Hwang, Yuhoon

    Zero valent iron is commonly used in a variety of treatment technologies (e.g. permeable reactive barriers), though recently a heavier focus has been placed on nano-sized zero valent iron (nZVI). Having superior reductive properties and large surface areas, nZVI is ideal for the degradation...... of chemicals such as azo dyes and trichloroethylene (TCE). However, stabilization and immobilization of nZVI is a key parameter in its effectiveness as a chemical degradation agent for both in-situ and ex-situ applications. Most importantly, this inhibits unwanted iron oxidation from the environment...

  6. Preparation of EVA/silica nano composites characterized with solid state nuclear magnetic resonance; Obtencao de nanocomposito de EVA/SILICA e caracterizacao por ressonancia magnetica nuclear no estado solido

    Energy Technology Data Exchange (ETDEWEB)

    Passos, Adriano A.; Tavares, Maria I.B.; Neto, Roberto C.P.; Moreira, Leonardo A.; Ferreira, Antonio G., E-mail: mibt@ima.ufrj.br [Centro de Tecnologia, Instituto de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Nano composites of poly(ethylene-co-vinyl acetate)/silica (SiO{sub 2}) with dimensions of ca. 40 nm were prepared via solution intercalation employing chloroform as a solvent. They were mainly characterized with nuclear magnetic resonance spectroscopy (NMR) employing carbon-13 (polymeric matrix), silicon-29 (nanoparticles) and through the determination of the proton spin-lattice relaxation time in the rotating frame (T{sub 1{rho}H}) (polymer matrix). From the NMR results it was inferred that up to 5% of silica in mass a well dispersed nano composite was obtained, owing to a strong interaction between silica and the EVA matrix. (author)

  7. Investigation of Fano resonances induced by higher order plasmon modes on a circular nano-disk with an elongated cavity

    KAUST Repository

    Amin, Muhammad Ruhul

    2012-08-10

    In this paper, a planar metallic nanostructure design, which supports two distinct Fano resonances in its extinction cross-section spectrum under normally incident and linearly polarized electromagnetic field, is proposed. The proposed design involves a circular disk embedding an elongated cavity; shifting and rotating the cavity break the symmetry of the structure with respect to the incident field and induce higher order plasmon modes. As a result, Fano resonances are generated in the visible spectrum due to the destructive interference between the sub-radiant higher order modes and super-radiant the dipolar mode. The Fano resonances can be tuned by varying the cavity\\'s width and the rotation angle. An RLC circuit, which is mathematically equivalent to a mass-spring oscillator, is proposed to model the optical response of the nanostructure design.

  8. Preparation of Graphene/Gold Nano-Hybrid Using Diamine Linker as Effective Surface-Enhanced Raman Scattering Platforms.

    Science.gov (United States)

    Yoon, Sang Su; Lee, Wonoh; Byun, Joon Hyung; Lee, Jea Uk

    2015-11-01

    Development of simple and efficient method for the large-scale production of gaphene/metal nanoparticle hybrids is highly desirable for practical applications, such as catalyst, energy generation and storage, optoelectronics, and sensors. Here, we present a facile approach for the preparation of graphene/gold nanoparticle (AuNP) hybrids by simply mixing the functionalized graphene oxide and AuNPs in aqueous media. Among various functionalized graphene sheets, amine-functionalized graphene oxide (GO-NH2) is used as the hybrid platform due to its synthetic convenience, good dispersity, scalable production with low cost, and positive charge on the surfacce, which could immobilize the AuNPs on the graphene sheets via electrostatic interaction. The synthesized graphene/AgNP hybrids show high surface-enhanced Raman scattering (SERS) sensitivity due to the combined effects of the high contents of amine functional groups on the GO-NH2 surface to adsorb more AgNPs and the electromagnetic enhancement of AgNPs.

  9. Electromechanical model of a resonating nano-cantilever-based sensor for high-resolution and high-sensitivity mass detection

    DEFF Research Database (Denmark)

    Abadal, G.; Davis, Zachary James; Helbo, Bjarne;

    2001-01-01

    A simple linear electromechanical model for an electrostatically driven resonating cantilever is derived. The model has been developed in order to determine dynamic quantities such as the capacitive current flowing through the cantilever-driver system at the resonance frequency, and it allows us...... to calculate static magnitudes such as position and voltage of collapse or the voltage versus deflection characteristic. The model is used to demonstrate the theoretical sensitivity on the attogram scale of a mass sensor based on a nanometre-scale cantilever, and to analyse the effect of an extra feedback loop...

  10. Circuit-tunable sub-wavelength THz resonators: hybridizing optical cavities and loop antennas.

    Science.gov (United States)

    Paulillo, B; Manceau, J M; Degiron, A; Zerounian, N; Beaudoin, G; Sagnes, I; Colombelli, R

    2014-09-08

    We demonstrate subwavelength electromagnetic resonators operating in the THz spectral range, whose spectral properties and spatial/angular patterns can be engineered in a similar way to an electronic circuit. We discuss the device concept, and we experimentally study the tuning of the resonant frequency as a function of variable capacitances and inductances. We then elucidate the optical coupling properties. The radiation pattern, obtained by angle-resolved reflectance, reveals that the system mainly couples to the outside world via a magnetic dipolar interaction.

  11. FDTD Acceleration for Cylindrical Resonator Design Based on the Hybrid of Single and Double Precision Floating-Point Computation

    Directory of Open Access Journals (Sweden)

    Hasitha Muthumala Waidyasooriya

    2014-01-01

    Full Text Available Acceleration of FDTD (finite-difference time-domain is very important for the fields such as computational electromagnetic simulation. We consider the FDTD simulation model of cylindrical resonator design that requires double precision floating-point and cannot be done using single precision. Conventional FDTD acceleration methods have a common problem of memory-bandwidth limitation due to the large amount of parallel data access. To overcome this problem, we propose a hybrid of single and double precision floating-point computation method that reduces the data-transfer amount. We analyze the characteristics of the FDTD simulation to find out when we can use single precision instead of double precision. According to the experimental results, we achieved over 15 times of speed-up compared to the CPU single-core implementation and over 1.52 times of speed-up compared to the conventional GPU-based implementation.

  12. Surface-enhanced localized surface plasmon resonance biosensing of avian influenza DNA hybridization using subwavelength metallic nanoarrays

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Shin Ae; Jang, Sung Min; Kim, Sung June [School of Electrical Engineering and Computer Science, Seoul National University, Seoul 151-742 (Korea, Republic of); Byun, Kyung Min [Department of Biomedical Engineering, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Kim, Kyujung; Kim, Donghyun [Program of Nanomedical Science and Technology, Yonsei University, Seoul 120-749 (Korea, Republic of); Ma, Kyungjae; Oh, Youngjin [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Sung Guk [College of Veterinary Medicine, Cornell University, Ithaca, New York 14853 (United States); Shuler, Michael L, E-mail: kmbyun@khu.ac.kr [Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853 (United States)

    2010-09-03

    We demonstrated enhanced localized surface plasmon resonance (SPR) biosensing based on subwavelength gold nanoarrays built on a thin gold film. Arrays of nanogratings (1D) and nanoholes (2D) with a period of 200 nm were fabricated by electron-beam lithography and used for the detection of avian influenza DNA hybridization. Experimental results showed that both nanoarrays provided significant sensitivity improvement and, especially, 1D nanogratings exhibited higher SPR signal amplification compared with 2D nanohole arrays. The sensitivity enhancement is associated with changes in surface-limited reaction area and strong interactions between bound molecules and localized plasmon fields. Our approach is expected to improve both the sensitivity and sensing resolution and can be applicable to label-free detection of DNA without amplification by polymerase chain reaction.

  13. Observations of a free-energy source for intense electrostatic waves. [in upper atmosphere near upper hybrid resonance frequency

    Science.gov (United States)

    Kurth, W. S.; Frank, L. A.; Gurnett, D. A.; Burek, B. G.; Ashour-Abdalla, M.

    1980-01-01

    Significant progress has been made in understanding intense electrostatic waves near the upper hybrid resonance frequency in terms of the theory of multiharmonic cyclotron emission using a classical loss-cone distribution function as a model. Recent observations by Hawkeye 1 and GEOS 1 have verified the existence of loss-cone distributions in association with the intense electrostatic wave events, however, other observations by Hawkeye and ISEE have indicated that loss cones are not always observable during the wave events, and in fact other forms of free energy may also be responsible for the instability. Now, for the first time, a positively sloped feature in the perpendicular distribution function has been uniquely identified with intense electrostatic wave activity. Correspondingly, we suggest that the theory is flexible under substantial modifications of the model distribution function.

  14. Native and induced triplet nitrogen-vacancy centers in nano- and micro-diamonds: Half-field electron paramagnetic resonance fingerprint

    Energy Technology Data Exchange (ETDEWEB)

    Shames, A. I., E-mail: sham@bgu.ac.il [Department of Physics, Ben-Gurion University of the Negev, Be' er-Sheva 84105 (Israel); Osipov, V. Yu.; Vul’, A. Ya. [Ioffe Physical-Technical Institute, Polytechnicheskaya 26, 194021 St. Petersburg (Russian Federation); Bardeleben, H.-J. von [Institut des Nano Sciences de Paris-INSP, Université Pierre et Marie Curie/UMR 7588 au CNRS, 7500 Paris (France); Boudou, J.-P.; Treussart, F. [Laboratoire Aimé Cotton, CNRS, Université Paris-Sud and ENS Cachan, 91405 Orsay (France)

    2014-02-10

    Multiple frequency electron paramagnetic resonance (EPR) study of small (4–25 nm) nanodiamonds obtained by various dynamic synthesis techniques reveals systematic presence in the half-field (HF) region a distinctive doublet fingerprint consisting of resolved g{sub HF1} = 4.26 and g{sub HF2} = 4.00 signals. This feature is attributed to “forbidden” ΔM{sub S} = 2 transitions in EPR spectra of two native paramagnetic centers of triplet (S = 1) origin designated as TR1 and TR2, characterized by zero field splitting values D{sub 1} = 0.0950 ± 0.002 cm{sup −1} and D{sub 2} = 0.030 ± 0.005 cm{sup −1}. Nanodiamonds of ∼50 nm particle size, obtained by crushing of Ib type nitrogen rich synthetic diamonds, show only HF TR2 signal whereas the same sample undergone high energy (20 MeV) electron irradiation and thermal annealing demonstrates rise of HF TR1 signal. The same HF TR1 signals appear in the process of fabrication of fluorescent nanodiamonds from micron-size synthetic diamond precursors. Results obtained allow unambiguous attribution of the half-field TR1 EPR signals with g{sub HF1} = 4.26, observed in nano- and micron-diamond powders, to triplet negatively charged nitrogen-vacancy centers. These signals are proposed as reliable and convenient fingerprints in both qualitative and quantitative study of fluorescent nano- and micron-diamonds.

  15. Hybrid approaches to magnetic resonance thermometry using the proton resonance frequency shift and the spin-lattice relaxation time T1

    Science.gov (United States)

    Diakite, Mahamadou

    Minimally invasive thermal therapy under Magnetic Resonance Imaging (MRI) guidance is becoming popular with several applications in the process of getting FDA approval. The ability to determine in near real-time the temperature map of a tumor and its surrounding tissue makes MR thermometry very attractive and well suited for thermal treatment. The proton resonance frequency shift (PRF) is currently the gold standard method for temperature monitoring using MRI. However, its incapacity to measure temperature in fatty tissue limits the scope of its applicability. The spin lattice relaxation time T1, on the other hand, has shown good temperature sensitivity and works well in all types of tissues. In this dissertation, we have addressed a number of challenges currently affecting MRI thermometry. A non-CPMG Turbo Spin Echo (TSE) sequence has been implemented to monitor the temperature rise due to the high RF power deposition inherent to this sequence at high field (3T and higher). This new implementation allows TSE sequences to be used safely without altering their high contrast properties which make them appealing in clinical settings. Tissue damage assessment during thermal therapy is critical for the safety of the patient. We have developed a new hybrid PRF-T1 sequence that has the capability to provide simultaneously in near real-time the temperature map and T1 information, which is a good indication of the state of the tissue. The simplicity and the real-time capability of the newly developed sequence make it an ideal tool for tissue damage assessment. Temperature monitoring during thermal therapy in organs with large fat content have been hindered by the lack of an MRI thermometry method that can provide simultaneous temperature in fat and aqueous tissue. A new sequence and acquisition scheme have been developed to address this issue. In sum, this dissertation proposed several pulse sequence implementation techniques and an acquisition scheme to overcome some of

  16. Critical factors affecting the 3D microstructural formation in hybrid conductive adhesive materials studied by X-ray nano-tomography

    Science.gov (United States)

    Chen-Wiegart, Yu-Chen Karen; Figueroa-Santos, Miriam Aileen; Petrash, Stanislas; Garcia-Miralles, Jose; Wang, Jun

    2014-12-01

    Conductive adhesives are found favorable in a wide range of applications including a lead-free solder in micro-chips, flexible and printable electronics and enhancing the performance of energy storage devices. Composite materials comprised of metallic fillers and a polymer matrix are of great interest to be implemented as hybrid conductive adhesives. Here we investigated a cost-effective conductive adhesive material consisting of silver-coated copper as micro-fillers using synchrotron-based three-dimensional (3D) X-ray nano-tomography. The key factors affecting the quality and performance of the material were quantitatively studied in 3D on the nanometer scale for the first time. A critical characteristic parameter, defined as a shape-factor, was determined to yield a high-quality silver coating, leading to satisfactory performance. A `stack-and-screen' mechanism was proposed to elaborate such a phenomenon. The findings and the technique developed in this work will facilitate the future advancement of conductive adhesives to have a great impact in micro-electronics and other applications.Conductive adhesives are found favorable in a wide range of applications including a lead-free solder in micro-chips, flexible and printable electronics and enhancing the performance of energy storage devices. Composite materials comprised of metallic fillers and a polymer matrix are of great interest to be implemented as hybrid conductive adhesives. Here we investigated a cost-effective conductive adhesive material consisting of silver-coated copper as micro-fillers using synchrotron-based three-dimensional (3D) X-ray nano-tomography. The key factors affecting the quality and performance of the material were quantitatively studied in 3D on the nanometer scale for the first time. A critical characteristic parameter, defined as a shape-factor, was determined to yield a high-quality silver coating, leading to satisfactory performance. A `stack-and-screen' mechanism was proposed to

  17. Hybrid tip-enhanced nano-spectroscopy and -imaging of monolayer WSe2 with local strain control

    CERN Document Server

    Park, Kyoung-Duck; Kravtsov, Vasily; Clark, Genevieve; Xu, Xiaodong; Raschke, Markus B

    2016-01-01

    Many classes of two-dimensional (2D) materials have emerged as potential platforms for novel electronic and optical devices. However, the physical properties are strongly influenced by nanoscale heterogeneities in the form of edges, grain boundaries, and nucleation sites. Using combined tip-enhanced Raman scattering (TERS) and photoluminescence (TEPL) nano-spectroscopy and -imaging, we study the associated effects on the excitonic properties in monolayer WSe2 grown by physical vapor deposition (PVD). With <15 nm spatial resolution we resolve nonlocal nanoscale correlations of PL spectral intensity and shifts with crystal edges and internal twin boundaries associated with the expected exciton diffusion length. Through an active atomic force tip interaction we can control the crystal strain on the nanoscale, and tune the local bandgap in reversible (up to 24 meV shift) and irreversible (up to 48 meV shift) fashion. This allows us to distinguish the effect of strain from the dominant influence of defects on t...

  18. Colloidal Au-enhanced surface plasmon resonance imaging: application in a DNA hybridization process

    Science.gov (United States)

    Manera, M. G.; Spadavecchia, J.; Taurino, A.; Rella, R.

    2010-03-01

    The detection of the DNA hybridization mechanism using monodispersed gold nanoparticles as labels is an interesting alternative to increase the sensitivity of the SPR imaging technique. DNA-modified Au nanoparticles (DNA-Au NPs) containing single-stranded (ss) portions of DNA were prepared by monitoring their monolayer formation by UV-vis spectroscopy. The hybridization process between specific thio-oligonucleotides immobilized on the DNA-Au NPs and the corresponding complementary strands is reported and compared with the traditional hybridization process on properly self-assembled thin gold films deposited on glass substrates. A remarkable signal amplification is observed, following the incorporation of colloidal Au into a SPR biosensing experiment, resulting in an increased SPR response to DNA-DNA interactions. In particular Fusarium thiolated DNA (5'HS poly(T)15ATC CCT CAA AAA CTG CCG CT-3) and trichothecenes complementary DNA (5'-AGC GGC AGT TTT TGA GGG AT-3') sequences have been explored due to their possible application to agro-industry for the control of food quality.

  19. Fabrication and interfacial electronic structure studies on polypyrrole/TiO2 nano hybrid systems for photovoltaic aspects.

    Science.gov (United States)

    Kumar, Ganesan Mohan; Kawakita, Jin; Jayavel, Ramasamy

    2011-05-01

    The progress in studying the interfacial electronic structures of the developing new class of hybrid organic/inorganic material systems have envisaged a new dimension into the field of photovoltaics, which could be of great help in understanding the nature of charge transfer in them. In this regard, electropolymerization of pyrrole monomers have been carried out at room temperature on the surface of TiO2 working electrodes (assisted by UV radiations) and their interfacial electronic structure has been studied as a function of the applied photo anodic potentials. The formation of polypyrrole deposits has been ensured using FT-IR and Raman spectroscopy. Surface analysis of the hybrid matrix revealed the tendency of polymer molecules to cover up the spherical surface of TiO2 nanoparticles that could help in improving the light absorption rate. Signals (bands) corresponding to pyrrole molecules observed in the ultraviolet photoelectron spectroscopy measurements have been correlated with the polaronic states formed and identified to shift as a function of the applied photo anodic potentials, revealing the decrease in work function of the hybrid system to take place (confirmed using cyclic voltammetry measurements). The decreasing trend in the work function elucidates the adjustment in electronic structure of the system (hybrid materials possessing smaller work functions are generally preferred for photovoltaic studies). The aforementioned behavioural aspects have been reasoned with the increase in overpotential values for polarization, from the decrease in up-take rate of the anionic dopant, which increases the current density values, thereby modifying the conductivity of the systems.

  20. Low Temperature Sensing Properties of a Nano Hybrid Material Based on ZnO Nanotetrapods and Titanyl Phthalocyanine

    Directory of Open Access Journals (Sweden)

    Davide Calestani

    2013-03-01

    Full Text Available ZnO nanotetrapods have recently been exploited for the realization of high-sensitivity gas sensors, but they are affected by the typical drawbacks of metal-oxides, i.e., poor selectivity and a relatively high working temperature. On the other hand, it has been also demonstrated that the combined use of nanostructured metal oxides and organic molecules can improve the gas sensing performance sensitivity or selectivity, even at lower temperatures. A gas sensor device, based on films of interconnected ZnO nanotetrapods properly functionalized by titanyl phthalocyanine (TiOPc, has been realized in order to combine the high surface to volume ratio and structural stability of the crystalline ZnO nanostructures with the enhanced sensitivity of the semiconducting TiOPc molecule, especially at low temperature. The electronic properties of the resulting nanohybrid material are different from those of each single component. The response of the hybrid nanostructure towards different gases has been compared with that of ZnO nanotetrapod without functionalization in order to highlight the peculiar properties of the hybrid interaction(s. The dynamic response in time has been studied for different gases and temperatures; in particular, an increase in the response to NO2 has been observed, even at room temperature. The formation of localized p-n heterojunctions and the possibility of exchanging charge carriers at the hybrid interface is shown to be crucial for the sensing mechanism.

  1. A polypeptide-DNA hybrid with selective linking capability applied to single molecule nano-mechanical measurements using optical tweezers.

    Science.gov (United States)

    Moayed, Fatemeh; Mashaghi, Alireza; Tans, Sander J

    2013-01-01

    Many applications in biosensing, biomaterial engineering and single molecule biophysics require multiple non-covalent linkages between DNA, protein molecules, and surfaces that are specific yet strong. Here, we present a novel method to join proteins and dsDNA molecule at their ends, in an efficient, rapid and specific manner, based on the recently developed linkage between the protein StrepTactin (STN) and the peptide StrepTag II (ST). We introduce a two-step approach, in which we first construct a hybrid between DNA and a tandem of two STs peptides (tST). In a second step, this hybrid is linked to polystyrene bead surfaces and Maltose Binding Protein (MBP) using STN. Furthermore, we show the STN-tST linkage is more stable against forces applied by optical tweezers than the commonly used biotin-Streptavidin (STV) linkage. It can be used in conjunction with Neutravidin (NTV)-biotin linkages to form DNA tethers that can sustain applied forces above 65 pN for tens of minutes in a quarter of the cases. The method is general and can be applied to construct other surface-DNA and protein-DNA hybrids. The reversibility, high mechanical stability and specificity provided by this linking procedure make it highly suitable for single molecule mechanical studies, as well as biosensing and lab on chip applications.

  2. A polypeptide-DNA hybrid with selective linking capability applied to single molecule nano-mechanical measurements using optical tweezers.

    Directory of Open Access Journals (Sweden)

    Fatemeh Moayed

    Full Text Available Many applications in biosensing, biomaterial engineering and single molecule biophysics require multiple non-covalent linkages between DNA, protein molecules, and surfaces that are specific yet strong. Here, we present a novel method to join proteins and dsDNA molecule at their ends, in an efficient, rapid and specific manner, based on the recently developed linkage between the protein StrepTactin (STN and the peptide StrepTag II (ST. We introduce a two-step approach, in which we first construct a hybrid between DNA and a tandem of two STs peptides (tST. In a second step, this hybrid is linked to polystyrene bead surfaces and Maltose Binding Protein (MBP using STN. Furthermore, we show the STN-tST linkage is more stable against forces applied by optical tweezers than the commonly used biotin-Streptavidin (STV linkage. It can be used in conjunction with Neutravidin (NTV-biotin linkages to form DNA tethers that can sustain applied forces above 65 pN for tens of minutes in a quarter of the cases. The method is general and can be applied to construct other surface-DNA and protein-DNA hybrids. The reversibility, high mechanical stability and specificity provided by this linking procedure make it highly suitable for single molecule mechanical studies, as well as biosensing and lab on chip applications.

  3. A Polypeptide-DNA Hybrid with Selective Linking Capability Applied to Single Molecule Nano-Mechanical Measurements Using Optical Tweezers

    Science.gov (United States)

    Tans, Sander J.

    2013-01-01

    Many applications in biosensing, biomaterial engineering and single molecule biophysics require multiple non-covalent linkages between DNA, protein molecules, and surfaces that are specific yet strong. Here, we present a novel method to join proteins and dsDNA molecule at their ends, in an efficient, rapid and specific manner, based on the recently developed linkage between the protein StrepTactin (STN) and the peptide StrepTag II (ST). We introduce a two-step approach, in which we first construct a hybrid between DNA and a tandem of two STs peptides (tST). In a second step, this hybrid is linked to polystyrene bead surfaces and Maltose Binding Protein (MBP) using STN. Furthermore, we show the STN-tST linkage is more stable against forces applied by optical tweezers than the commonly used biotin-Streptavidin (STV) linkage. It can be used in conjunction with Neutravidin (NTV)-biotin linkages to form DNA tethers that can sustain applied forces above 65 pN for tens of minutes in a quarter of the cases. The method is general and can be applied to construct other surface-DNA and protein-DNA hybrids. The reversibility, high mechanical stability and specificity provided by this linking procedure make it highly suitable for single molecule mechanical studies, as well as biosensing and lab on chip applications. PMID:23336001

  4. Hybrid Positron Emission Tomography/Magnetic Resonance Imaging: Challenges, Methods, and State of the Art of Hardware Component Attenuation Correction.

    Science.gov (United States)

    Paulus, Daniel H; Quick, Harald H

    2016-10-01

    Attenuation correction (AC) is an essential step in the positron emission tomography (PET) data reconstruction process to provide accurate and quantitative PET images. The introduction of PET/magnetic resonance (MR) hybrid systems has raised new challenges but also possibilities regarding PET AC. While in PET/computed tomography (CT) imaging, CT images can be converted to attenuation maps, MR images in PET/MR do not provide a direct relation to attenuation. For the AC of patient tissues, new methods have been suggested, for example, based on image segmentation, atlas registration, or ultrashort echo time MR sequences. Another challenge in PET/MR hybrid imaging is AC of hardware components that are placed in the PET/MR field of view, such as the patient table or various radiofrequency (RF) coils covering the body of the patient for MR signal detection. Hardware components can be categorized into 4 different groups: (1) patient table, (2) RF receiver coils, (3) radiation therapy equipment, and (4) PET and MR imaging phantoms. For rigid and stationary objects, such as the patient table and some RF coils like the head/neck coil, predefined CT-based attenuation maps stored on the system can be used for automatic AC. Flexible RF coils are not included into the AC process till now because they can vary in position as well as in shape and are not accurately detectable with the PET/MR system.This work summarizes challenges, established methods, new concepts, and the state of art in hardware component AC in the context of PET/MR hybrid imaging. The work also gives an overview of PET/MR hardware devices, their attenuation properties, and their effect on PET quantification.

  5. 纳米MgO/PI杂化薄膜的制备及其击穿特性%Preparation and Breakdown Characteristic of Nano-MgO/PI Hybrid Film

    Institute of Scientific and Technical Information of China (English)

    范勇; 王春平; 陈昊; 杨瑞宵

    2013-01-01

      Nano-magnesia(MgO) particles were prepared by micro emulsion-hydrothermal method, and the nano-MgO doping modified polyamide acids were prepared by in-situ polymerization, then a series of na-no-MgO hybrid films with nano-MgO content of 0%, 2%, 4%, 6% and 8% were prepared, and their breakdown characteristics were studied. The results show that the nano-MgO particles are well-distributed in the polyimide films. When the nano-MgO content is about 4%, the electrical strength attain maximum.%  采用微乳化-热液法制备了纳米氧化镁粒子,并原位聚合制得纳米氧化镁掺杂改性聚酰胺酸,制备出纳米氧化镁掺杂量分别为0%、2%、4%、6%、8%的杂化聚酰亚胺薄膜,并研究了其击穿特性。结果表明:无机纳米氧化镁粒子在聚酰亚胺基体中分布均匀,纳米氧化镁掺杂量约为4%时,电气强度出现最大值。

  6. A Compact High-Pass Filter Using Hybrid Microstrip/Nonuniform CPW with Dual-Mode Resonant Response

    Directory of Open Access Journals (Sweden)

    Hui Chen

    2016-01-01

    Full Text Available A novel and miniature high-pass filter (HPF based on a hybrid-coupled microstrip/nonuniform coplanar waveguide (CPW resonator is proposed in this article, in which the designed CPW has exhibited a wideband dual-mode characteristic within the desired high-pass frequency range. The implemented filter consists of the top microstrip coupled patches and the bottom modified nonuniformly short-circuited CPW resonator. Simulated results from the electromagnetic (EM analysis software and measured results from a vector network analyzer (VNA show a good agreement. A designed and fabricated prototype filter having a 3 dB cutoff frequency (fc of 5.78 GHz has shown an ultrawide high-pass behavior, which exhibits the highest passband frequency exceeding 4.0fc under the minimum insertion loss (IL 0.75 dB. The printed circuit board (PCB area of the filter is approximately 0.062λg×0.093λg, where λg is the guided wavelength at fc.

  7. Parametric decay of plasma waves near the upper-hybrid resonance

    Science.gov (United States)

    Dodin, I. Y.; Arefiev, A. V.

    2017-03-01

    An intense X wave propagating perpendicularly to dc magnetic field is unstable with respect to a parametric decay into an electron Bernstein wave and a lower-hybrid wave. A modified theory of this effect is proposed that extends to the high-intensity regime, where the instability rate γ ceases to be a linear function of the incident-wave amplitude. An explicit formula for γ is derived and expressed in terms of cold-plasma parameters. Theory predictions are in reasonable agreement with the results of the particle-in-cell simulations presented in a separate publication.

  8. Hybrid Active Filter with Variable Conductance for Harmonic Resonance Suppression in Industrial Power Systems

    DEFF Research Database (Denmark)

    Lee, Tzung-Lin; Wang, Yen-Ching; Li, Jian-Cheng

    2015-01-01

    -tuned passive filter and an active filter in series connection, both dc voltage and kVA rating of the active filter are dramatically decreased compared with the pure shunt active filter. In real application, this feature is very attractive since the active power filter with fully power electronics is very...... expensive. A reasonable trade-off between filtering performances and cost is to use the hybrid active filter. Design consideration are presented and experimental results are provided to validate effectiveness of the proposed method. Furthermore, this paper discusses filtering performances on line impedance...

  9. Study of the hybrid controller electronics for the nano-stabilization of mechanical vibrations of CLIC quadrupoles

    CERN Document Server

    Fernandez Carmona, P; Collette, C; Esposito, M; Guinchard, M; Janssens, S; Kuzmin, A; Moron Ballester, R

    2011-01-01

    In order to achieve the required levels of luminosity in the CLIC linear collider, mechanical stabilization of quadrupoles to the nanometre level is required. The paper describes a design of hybrid electronics combining an analogue controller and digital communication with the main machine controller. The choice of local analogue control ensures the required low latency while still keeping sufficiently low noise level. Furthermore, it reduces the power consumption, rack space and cost. Sensitivity to radiation single events upsets is reduced compared to a digital controller. The digital part is required for fine tuning and real time monitoring via digitization of critical parameters.

  10. Heavy metal incorporated helium ion active hybrid non-chemically amplified resists: Nano-patterning with low line edge roughness

    Science.gov (United States)

    Reddy, Pulikanti Guruprasad; Thakur, Neha; Lee, Chien-Lin; Chien, Sheng-Wei; Pradeep, Chullikkattil P.; Ghosh, Subrata; Tsai, Kuen-Yu; Gonsalves, Kenneth E.

    2017-08-01

    Helium (He) ion lithography is being considered as one of the most promising and emerging technology for the manufacturing of next generation integrated circuits (ICs) at nanolevel. However, He-ion active resists are rarely reported. In this context, we are introducing a new non-chemically amplified hybrid resist (n-CAR), MAPDSA-MAPDST, for high resolution He-ion beam lithography (HBL) applications. In the resist architecture, 2.15 % antimony is incorporated as heavy metal in the form of antimonate. This newly developed resists has successfully used for patterning 20 nm negative tone features at a dose of 60 μC/cm2. The resist offered very low line edge roughness (1.27±0.31 nm) for 20 nm line features. To our knowledge, this is the first He-ion active hybrid resist for nanopatterning. The contrast (γ) and sensitivity (E0) of this resist were calculated from the contrast curve as 0.73 and 7.2 μC/cm2, respectively.

  11. Heavy metal incorporated helium ion active hybrid non-chemically amplified resists: Nano-patterning with low line edge roughness

    Directory of Open Access Journals (Sweden)

    Pulikanti Guruprasad Reddy

    2017-08-01

    Full Text Available Helium (He ion lithography is being considered as one of the most promising and emerging technology for the manufacturing of next generation integrated circuits (ICs at nanolevel. However, He-ion active resists are rarely reported. In this context, we are introducing a new non-chemically amplified hybrid resist (n-CAR, MAPDSA-MAPDST, for high resolution He-ion beam lithography (HBL applications. In the resist architecture, 2.15 % antimony is incorporated as heavy metal in the form of antimonate. This newly developed resists has successfully used for patterning 20 nm negative tone features at a dose of 60 μC/cm2. The resist offered very low line edge roughness (1.27±0.31 nm for 20 nm line features. To our knowledge, this is the first He-ion active hybrid resist for nanopatterning. The contrast (γ and sensitivity (E0 of this resist were calculated from the contrast curve as 0.73 and 7.2 μC/cm2, respectively.

  12. Wear resistance and friction reduction in acrylo nitrile butadiene rubber through hybrid combination of graphite flakes and nano tungsten disulphide

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Neha, E-mail: neha87bhu@gmail.com [Defence Material Store Research Development and Establishment (DMSRDE), DRDO, GT Road, Kanpur 208013, U.P (India); Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra (India); Pandey, Akanksha; Parihar, A. S.; Mishra, A. K.; Mukhopadhyay, K.; Prasad, N. E. [Defence Material Store Research Development and Establishment (DMSRDE), DRDO, GT Road, Kanpur 208013, U.P (India); Gandhi, M. N.; Bhattacharyya, A. R. [Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra (India)

    2016-05-06

    Friction and wear have considerable role in the life span of two interacting parts. Incorporation of nanofillers in polymers/elastomers matrix causes commendable changes in its tribologicalproperties. The main purpose of this work is to reduce the coefficient of friction and wear rate of Acrylo Nitrile Butadiene rubber (NBR). To achieve such objective traditionally well knownlubricants graphite(G), tungsten disulphide (WS{sub 2}) and there hybrid combination was incorporated in NBR matrix. Effect of applied load (force) and concentration of fillers on tribological properties of NBR had been studied. The filler incorporation enhanced the hardnessby 8%, showed resistance to hydraulic oil and aging effect also got improved significantly. A particular optimized concentration of NBR with hybrid combination of 2% WS{sub 2} and 4% Graphite showed minimum coefficient of friction as well as wear rate. A hypothesis could be attributed that similar lamellar structure of WS{sub 2} and Graphite along with formation of a stable nanoscale disulfide tribofilmcould result in lowering of friction. These substantially improved properties of nanoreinforced rubber materials would definitely pave promising path for plethora of potential technological applications.

  13. Wear resistance and friction reduction in acrylo nitrile butadiene rubber through hybrid combination of graphite flakes and nano tungsten disulphide

    Science.gov (United States)

    Agrawal, Neha; Pandey, Akanksha; Parihar, A. S.; Mishra, A. K.; Gandhi, M. N.; Bhattacharyya, A. R.; Mukhopadhyay, K.; Prasad, N. E.

    2016-05-01

    Friction and wear have considerable role in the life span of two interacting parts. Incorporation of nanofillers in polymers/elastomers matrix causes commendable changes in its tribologicalproperties. The main purpose of this work is to reduce the coefficient of friction and wear rate of Acrylo Nitrile Butadiene rubber (NBR). To achieve such objective traditionally well knownlubricants graphite(G), tungsten disulphide (WS2) and there hybrid combination was incorporated in NBR matrix. Effect of applied load (force) and concentration of fillers on tribological properties of NBR had been studied. The filler incorporation enhanced the hardnessby 8%, showed resistance to hydraulic oil and aging effect also got improved significantly. A particular optimized concentration of NBR with hybrid combination of 2% WS2 and 4% Graphite showed minimum coefficient of friction as well as wear rate. A hypothesis could be attributed that similar lamellar structure of WS2 and Graphite along with formation of a stable nanoscale disulfide tribofilmcould result in lowering of friction. These substantially improved properties of nanoreinforced rubber materials would definitely pave promising path for plethora of potential technological applications.

  14. Resonance Energy Transfer in Hybrid Devices in the Presence of a Surface

    DEFF Research Database (Denmark)

    Kopylov, Oleksii; Huck, Alexander; Kadkhodazadeh, Shima

    2014-01-01

    We have studied room-temperature, nonradiative resonant energy transfer from InGaN/GaN quantum wells to CdSe/ZnS nanocrystals separated by aluminum oxide layers of different thicknesses. Nonradiative energy transfer from the quantum wells to the nanocrystals at separation distances of up...... to approximately 10 nm was observed. By comparing the carrier dynamics of the quantum wells and the nanocrystals, we found that nonradiative recombination via surface states, generated during dry etching of the wafer, counteracts the nonradiative energy-transfer process to the nanocrystals and therefore decreases...

  15. Book Review: Nano physics & Nano technology

    Directory of Open Access Journals (Sweden)

    Abdolkhaled Zaree

    2012-12-01

    Full Text Available During last decades, there are a lot of emphases on studying material behavior in atomic scale. In most scientific and engineering fields, one can see the effect of nanotechnology. The aim of nanoscience is to design and fabrication of new and applicable materials. Nowadays, Nano is a popular science which chemists, physicist, doctors, engineers, financial managers and environment's fans for creating a good life via nanoscience have a great cooperation with each others. Materials in nano scale such as nanotubes and nanowires have extraordinary properties which by optimization of these properties in nano scale and then develop these properties to macro scale, they've been challenging issues. For instance, materials in nano scale improve mechanical properties of polymers and metallic materials via nano particles and on the other hand by producing a thin film on surfaces improve surface hardening. Besides, nanotechnology is in hi-tech industries such as magnetic devices, surface coating, and biomaterial, material having sensors, polymers, gels, ceramics and intelligent membrane. Nano-carbon tubes are considered intelligent due to the fact that they couple electrochemical and elastic properties simultaneously, hence have greater activation energy density in comparison with other intelligent materials. Studying nanoscience is important because it causes the life to be better. Future Materials and structures will have a lot of outstanding properties. Intelligent machines can repair, recycle and reconstruct themselves. All these features are only possible in nano zone. Nano in engineering science can provide the possibility of making light missiles for exploring space. The reduced weight can be achieved by replacing traditional materials with hybrid nanocomposites.

  16. Quantum charge pumping through resonant crossed Andreev reflection in a superconducting hybrid junction of silicene

    Science.gov (United States)

    Paul, Ganesh C.; Saha, Arijit

    2017-01-01

    We theoretically investigate the phenomena of adiabatic quantum charge pumping through a normal-insulator-superconductor-insulator-normal (NISIN) setup of silicene within the scattering matrix formalism. Assuming a thin barrier limit, we consider the strength of the two barriers (χ1 and χ2) as the two pumping parameters in the adiabatic regime. Within this geometry, we obtain crossed Andreev reflection (CAR) with probability unity in the χ1-χ2 plane without concomitant transmission or elastic co-tunneling. Tunability of the band gap at the Dirac point by applying an external electric field perpendicular to the silicene sheet and variation of the chemical potential at the normal silicene region, open up the possibility of achieving either a perfect CAR or transmission process through our setup. This resonant behavior is periodic with the barrier strengths. We analyze the behavior of the pumped charge through the NISIN structure as a function of the pumping strength and angles of the incident electrons. We show that large (Q ˜2 e ) pumped charge can be obtained through our geometry when the pumping contour encloses either the CAR or transmission resonance in the pumping parameter space. We discuss possible experimental feasibility of our theoretical predictions.

  17. Physisorption of Nucleic Acid Bases on Boron Nitride Nanotubes: A new class of Hybrid Nano-Bio Materials

    CERN Document Server

    Mukhopadhyay, Saikat; Scheicher, Ralph H; Pandey, Ravindra; Karna, Shashi P

    2009-01-01

    We investigate the adsorption of the nucleic acid bases, adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U) on the outer wall of a high curvature semiconducting single-walled boron nitride nanotube (BNNT) by first principles density functional theory calculations. The calculated binding energy shows the order: G>A~C~T~U implying that the interaction strength of the (high-curvature) BNNT with the nucleobases, G being an exception, is nearly the same. A higher binding energy for the G-BNNT conjugate appears to result from a stronger hybridization of the molecular orbitals of G and BNNT, since the charge transfer involved in the physisorption process is insignificant. A smaller energy gap predicted for the G-BNNT conjugate relative to that of the pristine BNNT may be useful in application of this class of biofunctional materials to the design of the next generation sensing devices.

  18. Osteoblast differentiation is enhanced by a nano-to-micro hybrid titanium surface created by Yb:YAG laser irradiation.

    Science.gov (United States)

    Mariscal-Muñoz, Eduardo; Costa, Carlos A S; Tavares, Hewerson S; Bianchi, Jonas; Hebling, Josimeri; Machado, João P B; Lerner, Ulf H; Souza, Pedro P C

    2016-04-01

    The aim of this study was to analyze the capacity of a new modified laser surface to stimulate calvarial osteoblasts isolated from neonatal mouse bones to differentiate and form mineralized nodules. Titanium discs were subjectezd or not to laser irradiation according to specific parameters and characterized. Osteoblasts isolated from neonatal mouse calvaria were cultured over the discs, and the capacity of these cells to proliferate (MTT assay), form mineralized nodules (Alizarin red assay), and enhance alkaline phosphatase activity (ALPase activity) was analyzed. Real-time PCR was used for quantification of gene expression. Laser-irradiated titanium discs (L) presented a rough nano-to-micrometric oxidized surface contrasting with the smooth pattern on polished discs (P). The Ra on the micrometric level increased from 0.32 ± 0.01 μm on P surfaces to 10.57 ± 0.39 μm on L surfaces. When compared with P, L promoted changes in osteoblast morphology, increased mineralized nodule formation in osteoblasts cultured on the surfaces for 14 days, and enhanced ALPase activity at days 7 and 14. Transcription factors triggering osteoblast differentiation (Runx2 and Sp7) and genes encoding the bone extracellular matrix proteins collagen type-1 (Col1a1), osteopontin (Spp1), and osteocalcin (Bglap) were upregulated in cells on L surfaces compared with those on P surfaces at days 1-14. Laser treatment of titanium surfaces created a rough surface that stimulated osteoblast differentiation. Laser treatment of titanium generates a reproducible and efficient surface triggering osteoblast differentiation that can be of importance for osteointegration.

  19. The sensitivity enhancement of tilted fibre Bragg grating sensors with polarization dependent resonant nano-scale coatings

    CERN Document Server

    Bialiayeu, Aliaksandr

    2015-01-01

    Fibre Bragg grating sensors have emerged as a simple, inexpensive, accurate, sensitive and reliable platform, a viable alternative to the traditional bulkier optical sensor platforms. In this work we present an extensive theoretical analysis of the tilted fibre Bragg grating sensor (TFBG) with a particular focus on its polarization-dependent properties. We have developed a highly efficient computer model capable of providing the full characterization of the TFBG device in less then $3$~minutes for a given state of incident light polarization. As a result, the polarization-dependent spectral response, the field distribution at the sensor surface as well as the fine structure of particular resonances have become accessible for theoretical analysis. As a part of this computer model we have developed a blazingly fast full-vector complex mode solver, capable of handling cylindrical waveguides of an arbitrary complex refractive index profile. Along with the theoretical study we have investigated optical properties ...

  20. Structural aspects and porosity features of nano-size high surface area alumina-silica mixed oxide catalyst generated through hybrid sol-gel route

    Energy Technology Data Exchange (ETDEWEB)

    Padmaja, P. [Ceramic Technology Division, Regional Research Laboratory (CSIR), Trivandrum 695019, Kerala (India)]. E-mail: padmavasudev@yahoo.com; Warrier, K.G.K. [Ceramic Technology Division, Regional Research Laboratory (CSIR), Trivandrum 695019, Kerala (India)]. E-mail: kgk_warrier@yahoo.com; Padmanabhan, M. [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala (India); Wunderlich, W. [Graduate School of Engineering, Nagoya Institute of Technology, 466-8555 Nagoya (Japan); Berry, F.J. [Department of Chemistry, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Mortimer, M. [Department of Chemistry, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Creamer, N.J. [Department of Chemistry, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2006-01-10

    Alumina-silica mixed oxide nano-catalyst materials with compositions 83.6 wt.% Al{sub 2}O{sub 3}-16.4 wt.% SiO{sub 2} (3Al{sub 2}O{sub 3}.1SiO{sub 2}), 71.82 wt.% Al{sub 2}O{sub 3}-28.18 wt.% SiO{sub 2} (3Al{sub 2}O{sub 3}.2SiO{sub 2}), 62.84 wt.% Al{sub 2}O{sub 3}-37.16 wt.% SiO{sub 2} (3Al{sub 2}O{sub 3}.3SiO{sub 2}) and 56.03 wt.% Al{sub 2}O{sub 3}-43.97 wt.% SiO{sub 2} (3Al{sub 2}O{sub 3}.4SiO{sub 2}) have been prepared by a hybrid sol-gel technique using boehmite as the precursor for alumina and tetraethoxysilane as that for silica. The bonding characteristics and coordination features around Al and Si in the mixed oxide catalysts have been studied using FTIR and {sup 27}Al MAS NMR after calcination at 400 deg. C which is the temperature region where cross-condensation is seen to take place. A high BET specific surface area of 287 m{sup 2} g{sup -1} is obtained for 3Al{sub 2}O{sub 3}.1SiO{sub 2} mixed oxide composition. The porosity features are further established by BET adsorption isotherms and pore size distribution analysis. The temperature-programmed desorption studies showed more surface active sites for the silica-rich composition, suggesting enhanced catalytic potential. The TEM features of the mixed oxides showed a homogeneous distribution of alumina and silica phases with particle sizes in the nano-range. The low silica-containing mixed oxide showed a needle-like morphology with a high aspect ratio of 1:50 and {approx}10 nm particle size while the silica-rich composition had particle size in a wide range ({approx}20-75 nm)

  1. Imaging Atherosclerosis with Hybrid Positron Emission Tomography/Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Ripa, Rasmus Sejersten; Kjær, Andreas

    2015-01-01

    Noninvasive imaging of atherosclerosis could potentially move patient management towards individualized triage, treatment, and followup. The newly introduced combined positron emission tomography (PET) and magnetic resonance imaging (MRI) system could emerge as a key player in this context. Both...... PET and MRI have previously been used for imaging plaque morphology and function: however, the combination of the two methods may offer new synergistic opportunities. Here, we will give a short summary of current relevant clinical applications of PET and MRI in the setting of atherosclerosis....... Additionally, our initial experiences with simultaneous PET/MRI for atherosclerosis imaging are presented. Finally, future potential vascular applications exploiting the unique combination of PET and MRI will be discussed....

  2. Hybrid aptamer-antibody linked fluorescence resonance energy transfer based detection of trinitrotoluene.

    Science.gov (United States)

    Sabherwal, Priyanka; Shorie, Munish; Pathania, Preeti; Chaudhary, Shilpa; Bhasin, K K; Bhalla, Vijayender; Suri, C Raman

    2014-08-05

    Combining synthetic macromolecules and biomolecular recognition units are promising in developing novel diagnostic and analysis techniques for detecting environmental and/or clinically important substances. Fluorescence resonance energy transfer (FRET) apta-immunosensor for explosive detection is reported using 2,4,6-trinitrotoluene (TNT) specific aptamer and antibodies tagged with respective FRET pair dyes in a sandwich immunoassay format. FITC-labeled aptamer was used as a binder molecule in the newly developed apta-immunoassay format where the recognition element was specific anti-TNT antibody labeled with rhodamine isothiocyanate. The newly developed sensing platform showed excellent sensitivity with a detection limit of the order of 0.4 nM presenting a promising candidate for routine screening of TNT in samples.

  3. Fluorescent resonance energy transfer based detection of biological contaminants through hybrid quantum dot-quencher interactions.

    Science.gov (United States)

    Ramadurai, D; Norton, E; Hale, J; Garland, J W; Stephenson, L D; Stroscio, M A; Sivananthan, S; Kumar, A

    2008-06-01

    A nanoscale sensor employing fluorescent resonance energy transfer interactions between fluorescent quantum dots (QDs) and organic quencher molecules can be used for the multiplexed detection of biological antigens in solution. Detection occurs when the antigens to be detected displace quencher-labelled inactivated (or dead) antigens of the same type attached to QD-antibody complexes through equilibrium reactions. This unquenches the QDs, allowing detection to take place through the observation of photoluminescence in solution or through the fluorescence imaging of unquenched QD complexes trapped on filter surfaces. Multiplexing can be accomplished by using several different sizes of QDs, with each size QD labelled with an antibody for a different antigen, providing the ability to detect several types of antigens or biological contaminants simultaneously in near real-time with high specificity and sensitivity.

  4. 纳米增效肥对杂交稻的增产效果研究%The Research of Increasing the Yield by Nano-synergistic Fertilizer on Hybrid Rice

    Institute of Scientific and Technical Information of China (English)

    张志明; 刘键; 韩振; 马国辉; 袁隆平

    2012-01-01

    纳米增效肥对杂交稻的研究机理表明,纳米碳遇水后变成超导体,能增加土壤电动电位。纳米碳溶胶可以使土壤胶体重组,释放出大量土壤营养元素。纳米增效肥使杂交稻根系外流NH4+数量减少,内吸NO3-数量增加,促进根系对土壤氮离子的吸收。田间试验结果表明,纳米增效肥不同施肥量与普通高效肥100%施肥量相比,有明显增产效果。施用60%纳米增效肥,增产幅度为4.41%~10.35%;施用70%纳米增效肥,增产幅度为9.53%~21.05%;施用100%纳米增效肥,增产幅度为4.67%~15.83%。可见,纳米增效肥可减少肥料施用量30%~40%,并有明显增产效果。%The mechanism of nano-synergistic fertilizer on hybrid rice showed that nano carbon mixed with water became the superconductor,which increased the electric potential of soil.The nano carbon sol made the soil colloid recombinant and release large amounts of nutrient elements.The nano-synergistic fertilizer made the outflow quantity of NH4+ reduce in hybrid rice root,increase the absorption quantity of NO3-,and promote the absorption of nitrogen ion in root system on soil.The field test results showed that compared with the normal synergistic fertilizer of 100% efficient fertilization,the nano-synergistic fertilizer had obvious yield-increasing effect.The nano-synergistic fertilizer could increase the yield 4.41%~10.35% with 60% fertilization,9.53%~21.05% with 70% fertilization,4.67%~15.83% with 100% fertilization.So the nano-synergistic fertilizer could reduce the amount of fertilizer 30%~40%,and has obvious yield-increasing effect.

  5. Resonant silicon nanoparticles for enhancement of light absorption and photoluminescence from hybrid perovskite films and metasurfaces.

    Science.gov (United States)

    Tiguntseva, E; Chebykin, A; Ishteev, A; Haroldson, R; Balachandran, B; Ushakova, E; Komissarenko, F; Wang, H; Milichko, V; Tsypkin, A; Zuev, D; Hu, W; Makarov, S; Zakhidov, A

    2017-08-31

    Recently, hybrid halide perovskites have emerged as one of the most promising types of materials for thin-film photovoltaic and light-emitting devices because of their low-cost and potential for high efficiency. Further boosting their performance without detrimentally increasing the complexity of the architecture is critically important for commercialization. Despite a number of plasmonic nanoparticle based designs having been proposed for solar cell improvement, inherent optical losses of the nanoparticles reduce photoluminescence from perovskites. Here we use low-loss high-refractive-index dielectric (silicon) nanoparticles for improving the optical properties of organo-metallic perovskite (MAPbI3) films and metasurfaces to achieve strong enhancement of photoluminescence as well as useful light absorption. As a result, we observed experimentally a 50% enhancement of photoluminescence intensity from a perovskite layer with silicon nanoparticles and 200% enhancement for a nanoimprinted metasurface with silicon nanoparticles on top. Strong increase in light absorption is also demonstrated and described by theoretical calculations. Since both silicon nanoparticle fabrication/deposition and metasurface nanoimprinting techniques are low-cost, we believe that the developed all-dielectric approach paves the way to novel scalable and highly effective designs of perovskite based metadevices.

  6. Supercritical CO2 assisted process for the production of high-purity and sterile nano-hydroxyapatite/chitosan hybrid scaffolds.

    Science.gov (United States)

    Ruphuy, G; Souto-Lopes, M; Paiva, D; Costa, P; Rodrigues, A E; Monteiro, F J; Salgado, C L; Fernandes, M H; Lopes, J C; Dias, M M; Barreiro, M F

    2017-05-04

    Hybrid scaffolds composed of hydroxyapatite (HAp), in particular in its nanometric form (n-HAp), and chitosan (CS) are promising materials for non-load-bearing bone graft applications. The main constraints of their production concern the successful implementation of the final purification/neutralization and sterilization steps. Often, the used purification strategies can compromise scaffold structural features, and conventional sterilization techniques can result in material's thermal degradation and/or contamination with toxic residues. In this context, this work presents a process to produce n-HAp/CS scaffolds mimicking bone composition and structure, where an innovative single step based on supercritical CO2 extraction was used for both purification and sterilization. A removal of 80% of the residual acetic acid was obtained (T = 75°C, p = 8.0 MPa, 2 extraction cycles of 2 h) giving rise to scaffolds exhibiting adequate interconnected porous structure, fast swelling and storage modulus compatible with non-load-bearing applications. Moreover, the obtained scaffolds showed cytocompatibility and osteoconductivity without further need of disinfection/sterilization procedures. Among the main advantages, the proposed process comprises only three steps (n-HAp/CS dispersion preparation; freeze-drying; and supercritical CO2 extraction), and the supercritical CO2 extraction show clear advantages over currently used procedures based on neutralization steps. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

  7. Nano-morphology induced additional surface plasmon resonance enhancement of SERS sensitivity in Ag/GaN nanowall network.

    Science.gov (United States)

    Sharvani, S; Upadhayaya, Kishor; Kumari, Gayatri; Narayana, Chandrabhas; Shivaprasad, S M

    2015-11-20

    The GaN nanowall network, formed by opening the screw dislocations by kinetically controlled MBE growth, possesses a large surface and high conductivity. Sharp apexed nanowalls show higher surface electron concentration in the band-tail states, in comparison to blunt apexed nanowalls. Uncapped silver nanoparticles are vapor deposited on the blunt and sharp GaN nanowall networks to study the morphological dependence of band-edge plasmon-coupling. Surface enhanced Raman spectroscopy studies performed with a rhodamine 6G analyte on these two configurations clearly show that the sharp nanowall morphology with smaller Ag nanoparticles shows higher enhancement of the Raman signal. A very large enhancement factor of 2.8 × 10(7) and a very low limit of detection of 10(-10) M is observed, which is attributed to the surface plasmon resonance owing to the high surface electron concentration on the GaN nanowall in addition to that of the Ag nanoparticles. The significantly higher sensitivity with same-sized Ag nanoparticles confirms the unconventional role of morphology-dependent surface charge carrier concentration of GaN nanowalls in the enhancement of Raman signals.

  8. Rheological behavior characteristics of TiO2-MWCNT/10w40 hybrid nano-oil affected by temperature, concentration and shear rate: An experimental study and a neural network simulating

    Science.gov (United States)

    Hemmat Esfe, Mohammad; Rostamian, Hossein; Reza Sarlak, Mohammad; Rejvani, Mousa; Alirezaie, Ali

    2017-10-01

    In this article, rheological behavior of TiO2-MWCNT (45-55%)/10w40 hybrid nano-oil was studied experimentally. The nano- oils were tested at temperature ranges of 5-55 °C and in shear rates up to 11,997 s-1. With respect to viscosity, shear stress and shear rate variations it was cleared that either of the base oil and nano-oil were non-Newtonian fluids. New equations which were based on thickness of the fluid were presented for different temperature values, R-squared values were between 0.9221 and 0.9998 (the precise of correlation changes depend on temperature). Also to predict the nano-oil behavior, neural network method was utilized. an artificial neural network (MLP type) were used to predict the viscosity in terms of temperature, solid volume fraction and shear stress. to compare the prediction precise of neural network and correlation the results of these two were compared with together. ANN showed more accurate results in comparison with correlation results. R2 and (MSE) were 0.9979 and 0.000016 respectively for the ANN.

  9. Ultrathin Terahertz Quarter-wave plate based on Split Ring Resonator and Wire Grating hybrid Metasurface

    Science.gov (United States)

    Nouman, Muhammad Tayyab; Hwang, Ji Hyun; Jang, Jae-Hyung

    2016-12-01

    Planar metasurface based quarter-wave plates offer various advantages over conventional waveplates in terms of compactness, flexibility and simple fabrication; however they offer very narrow bandwidth of operation. Here, we demonstrate a planar terahertz (THz) metasurface capable of linear to circular polarization conversion and vice versa in a wide frequency range. The proposed metasurface is based on horizontally connected split ring resonators and is realized on an ultrathin (0.05λ) zeonor substrate. The fabricated quarter waveplate realizes linear to circular polarization conversion in two broad frequency bands comprising 0.64-0.82 THz and 0.96-1.3 THz with an insertion loss ranging from -3.9 to -10 dB. By virtue of ultrathin sub wavelength thickness, the proposed waveplate design is well suited for application in near field THz optical systems. Additionally, the proposed metasurface design offers novel transmission phase characteristics that present further opportunities to realize dynamic polarization control of incident waves.

  10. Fano resonances in Majorana bound states-quantum dot hybrid systems

    Science.gov (United States)

    Schuray, Alexander; Weithofer, Luzie; Recher, Patrik

    2017-08-01

    We consider a quantum wire containing two Majorana bound states (MBS) at its ends that are tunnel-coupled to a current lead on one side and to a quantum dot (QD) on the other side. Using the method of full counting statistics we calculate the conductance and the zero-frequency noise. Using an effective low-energy model, we analyze in detail the Andreev reflection probability as a function of the various system parameters and show that it exhibits a Fano resonance (FR) line shape in the case of a weakly coupled QD as a function of the QD energy level when the two MBS overlap. The asymmetry parameter changes sign as the bias voltage is tuned through the MBS overlap energy. The FR is mirrored as a function of the QD level energy as long as tunneling from the dot to the more distant MBS is negligible. However, if both MBS are coupled to the lead and the QD, the height as well as the asymmetry of the line shapes cease to respect this symmetry. These two exclusive cases uniquely distinguish the coupling to a MBS from the coupling to a fermionic bound state that is shared between the two MBS. We complement the analysis by employing a discretized one-dimensional p -wave superconductor (Kitaev chain) for the quantum wire and show that the features of the effective low-energy model are robust towards a more complete Hamiltonian and also persist at finite temperature.

  11. Effect of micro-nano-hybrid structured hydroxyapatite bioceramics on osteogenic and cementogenic differentiation of human periodontal ligament stem cell via Wnt signaling pathway

    Directory of Open Access Journals (Sweden)

    Mao LX

    2015-11-01

    Full Text Available Lixia Mao,1,* Jiaqiang Liu,1,* Jinglei Zhao,1 Jiang Chang,2 Lunguo Xia,1 Lingyong Jiang,1 Xiuhui Wang,2 Kaili Lin,2,3 Bing Fang11Center of Craniofacial Orthodontics, Department of Oral and Cranio-maxillofacial Science, Top Priority Clinical Medical Center of Shanghai Municipal Commission of Health and Family Planning, Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine, Shanghai Jiao Tong University, 2State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 3Shanghai Engineering Research Center of Tooth Restoration and Regeneration, School of Stomatology, Tongji University, Shanghai, People’s Republic of China*These authors contributed equally to this workAbstract: The surface structure of bioceramic scaffolds is crucial for its bioactivity and osteoinductive ability, and in recent years, human periodontal ligament stem cells have been certified to possess high osteogenic and cementogenic differential ability. In the present study, hydroxyapatite (HA bioceramics with micro-nano-hybrid surface (mnHA [the hybrid of nanorods and microrods] were fabricated via hydrothermal reaction of the α-tricalcium phosphate granules as precursors in aqueous solution, and the effects of mnHA on the attachment, proliferation, osteogenic and cementogenic differentiations of human periodontal ligament stem cells as well as the related mechanisms were systematically investigated. The results showed that mnHA bioceramics could promote cell adhesion, proliferation, alkaline phosphatase (ALP activity, and expression of osteogenic/cementogenic-related markers including runt-related transcription factor 2 (Runx2, ALP, osteocalcin (OCN, cementum attachment protein (CAP, and cementum protein (CEMP as compared to the HA bioceramics with flat and dense surface. Moreover, mnHA bioceramics stimulated gene expression of low-density lipoprotein receptor

  12. Surface-Induced Dissociation of Protein Complexes in a Hybrid Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Jing; Zhou, Mowei; Gilbert, Joshua D.; Wolff, Jeremy J.; Somogyi, Árpád; Pedder, Randall E.; Quintyn, Royston S.; Morrison, Lindsay J.; Easterling, Michael L.; Paša-Tolić, Ljiljana; Wysocki, Vicki H.

    2017-01-03

    Mass spectrometry continues to develop as a valuable tool in the analysis of proteins and protein complexes. In protein complex mass spectrometry studies, surface-induced dissociation (SID) has been successfully applied in quadrupole time-of-flight (Q-TOF) instruments. SID provides structural information on non-covalent protein complexes that is complementary to other techniques. However, the mass resolution of Q-TOF instruments can limit the information that can be obtained for protein complexes by SID. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolution and ultrahigh mass accuracy measurements. In this study, an SID device was designed and successfully installed in a hybrid FT-ICR instrument in place of the standard gas collision cell. The SID-FT-ICR platform has been tested with several protein complex systems (homooligomers, a heterooligomer, and a protein-ligand complex, ranging from 53 kDa to 85 kDa), and the results are consistent with data previously acquired on Q-TOF platforms, matching predictions from known protein interface information. SID fragments with the same m/z but different charge states are well-resolved based on distinct spacing between adjacent isotope peaks, and the addition of metal cations and ligands can also be isotopically resolved with the ultrahigh mass resolution available in FT-ICR.

  13. Selective sequential separation of ABS/HIPS and PVC from automobile and electronic waste shredder residue by hybrid nano-Fe/Ca/CaO assisted ozonisation process.

    Science.gov (United States)

    Mallampati, Srinivasa Reddy; Lee, Byoung Ho; Mitoma, Yoshiharu; Simion, Cristian

    2017-02-01

    The separation of plastics containing brominated flame retardants (BFR) like (acrylonitrile-butadiene-styrene (ABS), high-impact polystyrene (HIPS), and polyvinyl chloride (PVC)) from automobile and electronic waste shredder residue (ASR/ESR) are a major concern for thermal recycling. In laboratory scale tests using a hybrid nano-Fe/Ca/CaO assisted ozonation treatment has been found to selectively hydrophilize the surface of ABS/HIPS and PVC plastics, enhancing ABS wettability and thereby promoting its separation from ASR/ESR by means of froth flotation. The water contact angles, of ABS/HIPS and PVC decreased, about 18.7°, 18.3°, and 17.9° in ASR and about 21.2°, 20.7°, and 20.0° in ESR respectively. SEM-EDS, FT-IR, and XPS analyses demonstrated a marked decrease in [Cl] and a significant increase in the number of hydrophilic groups, such as CO, CO, and (CO)O, on the PVC or ABS surface. Under froth flotation conditions at 50rpm, about 99.1% of combined fraction of ABS/HIPS in ASR samples and 99.6% of ABS/HIPS in ESR samples were separated as settled fraction. After separation, the purity of the recovered combined ABS/HIPS fraction was 96.5% and 97.6% in ASR and ESR samples respectively. Furthermore, at 150rpm a 100% PVC separation in the settled fraction, with 98% and 99% purity in ASR and ESR plastics, respectively. Total recovery of non-ABS/HIPS and PVC plastics reached nearly 100% in the floating fraction. Further, this process improved the quality of recycled ASR/ESR plastics by removing surface contaminants or impurities.

  14. Enhanced dielectric properties of poly(vinylidene fluoride) composites filled with nano iron oxide-deposited barium titanate hybrid particles

    Science.gov (United States)

    Zhang, Changhai; Chi, Qingguo; Dong, Jiufeng; Cui, Yang; Wang, Xuan; Liu, Lizhu; Lei, Qingquan

    2016-09-01

    We report enhancement of the dielectric permittivity of poly(vinylidene fluoride) (PVDF) generated by depositing magnetic iron oxide (Fe3O4) nanoparticles on the surface of barium titanate (BT) to fabricate BT–Fe3O4/PVDF composites. This process introduced an external magnetic field and the influences of external magnetic field on dielectric properties of composites were investigated systematically. The composites subjected to magnetic field treatment for 30 min at 60 °C exhibited the largest dielectric permittivity (385 at 100 Hz) when the BT–Fe3O4 concentration is approximately 33 vol.%. The BT–Fe3O4 suppressed the formation of a conducting path in the composite and induced low dielectric loss (0.3) and low conductivity (4.12 × 10‑9 S/cm) in the composite. Series-parallel model suggested that the enhanced dielectric permittivity of BT–Fe3O4/PVDF composites should arise from the ultrahigh permittivity of BT–Fe3O4 hybrid particles. However, the experimental results of the BT–Fe3O4/PVDF composites treated by magnetic field agree with percolation theory, which indicates that the enhanced dielectric properties of the BT–Fe3O4/PVDF composites originate from the interfacial polarization induced by the external magnetic field. This work provides a simple and effective way for preparing nanocomposites with enhanced dielectric properties for use in the electronics industry.

  15. Interfacial Chemistry and the Design of Solid-Phase Nucleic Acid Hybridization Assays Using Immobilized Quantum Dots as Donors in Fluorescence Resonance Energy Transfer

    OpenAIRE

    Krull, Ulrich J.; W. Russ Algar

    2011-01-01

    The use of quantum dots (QDs) as donors in fluorescence resonance energy transfer (FRET) offer several advantages for the development of multiplexed solid-phase QD-FRET nucleic acid hybridization assays. Designs for multiplexing have been demonstrated, but important challenges remain in the optimization of these systems. In this work, we identify several strategies based on the design of interfacial chemistry for improving sensitivity, obtaining lower limits of detection (LOD) and enabling th...

  16. Dielectric Properties of Polyimide Hybrid Film Doped with Nano Zirconium/Aluminum Oxide%纳米锆/铝氧化物杂化聚酰亚胺薄膜的介电性能

    Institute of Scientific and Technical Information of China (English)

    袁征; 范勇; 陈昊; 韩笑笑

    2011-01-01

    采用热液法制备了一系列不同Zr和Al比例的纳米粒子分散液,用原位聚合法分别制备了无机纳米杂化聚酰亚胺薄膜,并进行了SEM分析、电气强度和耐电晕测试.结果表明:Zr和A1的掺杂比例对杂化薄膜的耐电晕寿命及击穿场强影响较大,其耐电晕寿命最大可达Kapton100CR薄膜的4倍.%A series of nano-dispersions with different ratio of Zr and Al was prepared by hydrothermal method, and the corresponding inorganic nano-hybrid polyimide films were prepared through in-situ polymerization method. The hybrid film was characterized by SEM, electric strength and corona-resistant test. The results show that the doping ratio of Al and Zr has great effects on the corona-resistant life and breakdown strength of the hybrid film, and the maximum corona-resistant life is 4 times of that of Kapton 100 CR film.

  17. Plasmon assisted enhanced second-harmonic generation in single hybrid Au/ZnS nanowires

    Science.gov (United States)

    Jassim, Nadia M.; Wang, Kai; Han, Xiaobo; Long, Hua; Wang, Bing; Lu, Peixiang

    2017-02-01

    We demonstrate the enhanced second-harmonic generation (SHG) in single ZnS nanowires (NWs) attached with gold nanoparticles (Au NPs). The hybrid Au/ZnS NWs with different densities of the attached Au NPs were prepared by a simple solution impregnation method. By comparing with bare ZnS NWs, ∼1.3, ∼6.6, ∼7 and ∼2 times enhancement of SH intensity was achieved in the hybrid Au/ZnS NWs with low, moderate, high and ultrahigh densities of the attached Au NPs, respectively. The enhanced SHG in the hybrid Au/ZnS NWs is attributed to the strong local-fields from the Au cluster under the near-resonant condition, which is supported by the related dark-field scattering spectra. This hybrid Au/ZnS NWs provide a simple platform for enhancing nonlinear optical responses, which have potential applications in nano-probing and nano-sensing.

  18. A comparative study of resonant effects in two-dimensional active coated nano-particles of circular, polygonal, and elliptical shapes

    DEFF Research Database (Denmark)

    B.-Jørgensen, Mikkel; Kaminski, Piotr Marek; Ziolkowski, Richard W.

    and plasmonic structures. In regards to the latter, extensive analytical and numerical investigations were conducted on the theoretical designs of nano-antennas by use of passive and active coated nano-particles (CNPs) of various shapes and excitations. It was demonstrated that specifically designed active CNPs...

  19. Characteristics of electron cyclotron resonance plasma formed by lower hybrid current drive grill antenna

    Indian Academy of Sciences (India)

    P K Sharma; S L Rao; K Mishra; R G Trivedi; D Bora

    2008-03-01

    A 3.7 GHz system, which is meant for LHCD experiments on ADITYA tokamak, is used for producing ECR discharge. The ECR discharge is produced by setting the appropriate resonance magnetic field of 0.13 T, with hydrogen at a fill pressure of about 5 × 10-5 Torr. The RF powe r, up to 10 kW (of which ∼ 50% is reflected back), with a typical pulse length of 50 ms, is injected into the vacuum chamber of the ADITYA tokamak by a LHCD grill antenna and is used for plasma formation. The average coupled RF power density (the RF power/a typical volume of the plasma) is estimated to be ∼ 5 kW/m3. When the ECR appears inside the tokamak chamber for the given pumping frequency ( = 3.7 GHz) a plasma with a density () ∼ 4 × 1016 m-3 and electron temperature ∼ 8 eV is produced. The density and temperature during the RF pulse are measured by sets of Langmuir probes, located toroidally, on either side of the antenna. signals are also monitored to detect ionization. An estimate of density and temperature based on simple theoretical calculation agrees well with our experimental measurements. The plasma produced by the above mechanism is further used to characterize the ECR-assisted low voltage Ohmic start-up discharges. During this part of the experiments, Ohmic plasma is formed using capacitor banks. The plasma loop voltage is gradually decreased, till the discharge ceases to form. The same is repeated in the presence of ECR-formed plasma (RF pre-ionization), formed 10 ms prior to the loop voltage. We have observed that (with LHCD-induced) ECR-assisted Ohmic start-up discharges is reliably and repeatedly obtained with reduced loop voltage requirement and breakdown time decreases substantially. The current ramp-up rates also decrease with reduced loop voltage operation. These studies established that ECR plasma formed with LHCD system exhibits similar characteristics as reported earlier by dedicated ECR systems. This experiment also addresses the issue of whether ECR plasma

  20. PVA/Nano-SiO2杂化膜的制备及性能研究%Preparation and Properties of PVA/Nano-SiO2 Hybrid Films

    Institute of Scientific and Technical Information of China (English)

    迟长龙; 王延伟; 王玉周; 高元元; 于翔

    2014-01-01

    以聚乙烯醇(PVA)和正硅酸乙酯(TEOS)为原料,通过溶胶-凝胶(Sol-Gel)技术,制备出不同nano-SiO2含量的PVA/nano-SiO2杂化膜,并采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)等仪器测试和分析了杂化膜的结构和性能.结果表明:随着nano-SiO2含量的增加,PVA杂化膜的耐水性能增强,结晶能力下降,而力学性能呈现先增大后减小的趋势.当nano-SiO2的加入量在10%左右时,断裂伸长率由纯PVA膜的34.74%提高到55.52%,拉伸强度从33.08 MPa增加到49.98 MPa;而当nano-SiO2含量增加到20%以上时,nano-SiO2粒子会发生团聚,使得杂化膜的力学性能变差.

  1. Injectable In Situ Forming Hybrid Iron Oxide-Hyaluronic Acid Hydrogel for Magnetic Resonance Imaging and Drug Delivery

    NARCIS (Netherlands)

    Zhang, Y; Sun, Y.; Yang, X.; Hilborn, J.; Heerschap, A.; Ossipov, D.A.

    2014-01-01

    The development of multimodal in situ cross-linkable hyaluronic acid nanogels hybridized with iron oxide nanoparticles is reported. Utilizing a chemoselective hydrazone coupling reaction, the nanogels are converted to a macroscopic hybrid hydrogel without any additional reagent. Hydrophobic cargos

  2. Resonance Energy Transfer-Based Nucleic Acid Hybridization Assays on Paper-Based Platforms Using Emissive Nanoparticles as Donors.

    Science.gov (United States)

    Doughan, Samer; Noor, M Omair; Han, Yi; Krull, Ulrich J

    2017-01-01

    Quantum dots (QDs) and upconverting nanoparticles (UCNPs) are luminescent nanoparticles (NPs) commonly used in bioassays and biosensors as resonance energy transfer (RET) donors. The narrow and tunable emissions of both QDs and UCNPs make them versatile RET donors that can be paired with a wide range of acceptors. Ratiometric signal processing that compares donor and acceptor emission in RET-based transduction offers improved precision, as it accounts for fluctuations in the absolute photoluminescence (PL) intensities of the donor and acceptor that can result from experimental and instrumental variations. Immobilizing NPs on a solid support avoids problems such as those that can arise with their aggregation in solution, and allows for facile layer-by-layer assembly of the interfacial chemistry. Paper is an attractive solid support for the development of point-of-care diagnostic assays given its ubiquity, low-cost, and intrinsic fluid transport by capillary action. Integration of nanomaterials with paper-based analytical devices (PADs) provides avenues to augment the analytical performance of PADs, given the unique optoelectronic properties of nanomaterials. Herein, we describe methodology for the development of PADs using QDs and UCNPs as RET donors for optical transduction of nucleic acid hybridization. Immobilization of green-emitting QDs (gQDs) on imidazole functionalized cellulose paper is described for use as RET donors with Cy3 molecular dye as acceptors for the detection of SMN1 gene fragment. We also describe the covalent immobilization of blue-emitting UCNPs on aldehyde modified cellulose paper for use as RET donors with orange-emitting QDs (oQDs) as acceptors for the detection of HPRT1 gene fragment. The data described herein is acquired using an epifluorescence microscope, and can also be collected using technology such as a typical electronic camera.

  3. Automated segmentation of the quadratus lumborum muscle from magnetic resonance images using a hybrid atlas based - geodesic active contour scheme.

    Science.gov (United States)

    Jurcak, V; Fripp, J; Engstrom, C; Walker, D; Salvado, O; Ourselin, S; Crozier, S

    2008-01-01

    This study presents a novel method for the automatic segmentation of the quadratus lumborum (QL) muscle from axial magnetic resonance (MR) images using a hybrid scheme incorporating the use of non-rigid registration with probabilistic atlases (PAs) and geodesic active contours (GACs). The scheme was evaluated on an MR database of 7mm axial images of the lumbar spine from 20 subjects (fast bowlers and athletic controls). This scheme involved several steps, including (i) image pre-processing, (ii) generation of PAs for the QL, psoas (PS) and erector spinae+multifidus (ES+MT) muscles and (iii) segmentation, using 3D GACs initialized and constrained by the propagation of the PAs using non-rigid registration. Pre-processing of the images involved bias field correction based on local entropy minimization with a bicubic spline model and a reverse diffusion interpolation algorithm to increase the slice resolution to 0.98 x 0.98 x 1.75mm. The processed images were then registered (affine and non-rigid) and used to generate an average atlas. The PAs for the QL, PS and ES+MT were then generated by propagation of manual segmentations. These atlases were further analysed with specialised filtering to constrain the QL segmentation from adjacent non-muscle tissues (kidney, fat). This information was then used in 3D GACs to obtain the final segmentation of the QL. The automatic segmentation results were compared with the manual segmentations using the Dice similarity metric (DSC), with a median DSC for the right and left QL muscles of 0.78 (mean = 0.77, sd=0.07) and 0.75 (mean =0.74, sd=0.07), respectively.

  4. Enhancement of DFT-calculations at petascale: Nuclear Magnetic Resonance, Hybrid Density Functional Theory and Car-Parrinello calculations

    Science.gov (United States)

    Varini, Nicola; Ceresoli, Davide; Martin-Samos, Layla; Girotto, Ivan; Cavazzoni, Carlo

    2013-08-01

    One of the most promising techniques used for studying the electronic properties of materials is based on Density Functional Theory (DFT) approach and its extensions. DFT has been widely applied in traditional solid state physics problems where periodicity and symmetry play a crucial role in reducing the computational workload. With growing compute power capability and the development of improved DFT methods, the range of potential applications is now including other scientific areas such as Chemistry and Biology. However, cross disciplinary combinations of traditional Solid-State Physics, Chemistry and Biology drastically improve the system complexity while reducing the degree of periodicity and symmetry. Large simulation cells containing of hundreds or even thousands of atoms are needed to model these kind of physical systems. The treatment of those systems still remains a computational challenge even with modern supercomputers. In this paper we describe our work to improve the scalability of Quantum ESPRESSO (Giannozzi et al., 2009 [3]) for treating very large cells and huge numbers of electrons. To this end we have introduced an extra level of parallelism, over electronic bands, in three kernels for solving computationally expensive problems: the Sternheimer equation solver (Nuclear Magnetic Resonance, package QE-GIPAW), the Fock operator builder (electronic ground-state, package PWscf) and most of the Car-Parrinello routines (Car-Parrinello dynamics, package CP). Final benchmarks show our success in computing the Nuclear Magnetic Response (NMR) chemical shift of a large biological assembly, the electronic structure of defected amorphous silica with hybrid exchange-correlation functionals and the equilibrium atomic structure of height Porphyrins anchored to a Carbon Nanotube, on many thousands of CPU cores.

  5. Paper-based solid-phase nucleic acid hybridization assay using immobilized quantum dots as donors in fluorescence resonance energy transfer.

    Science.gov (United States)

    Noor, M Omair; Shahmuradyan, Anna; Krull, Ulrich J

    2013-02-05

    A paper-based solid-phase assay is presented for transduction of nucleic acid hybridization using immobilized quantum dots (QDs) as donors in fluorescence resonance energy transfer (FRET). The surface of paper was modified with imidazole groups to immobilize QD-probe oligonucleotide conjugates that were assembled in solution. Green-emitting QDs (gQDs) were FRET-paired with Cy3 acceptor. Hybridization of Cy3-labeled oligonucleotide targets provided the proximity required for FRET-sensitized emission from Cy3, which served as an analytical signal. The assay exhibited rapid transduction of nucleic acid hybridization within minutes. Without any amplification steps, the limit of detection of the assay was found to be 300 fmol with the upper limit of the dynamic range at 5 pmol. The implementation of glutathione-coated QDs for the development of nucleic acid hybridization assay integrated on a paper-based platform exhibited excellent resistance to nonspecific adsorption of oligonucleotides and showed no reduction in the performance of the assay in the presence of large quantities of noncomplementary DNA. The selectivity of nucleic acid hybridization was demonstrated by single-nucleotide polymorphism (SNP) detection at a contrast ratio of 19 to 1. The reuse of paper over multiple cycles of hybridization and dehybridization was possible, with less than 20% reduction in the performance of the assay in five cycles. This work provides an important framework for the development of paper-based solid-phase QD-FRET nucleic acid hybridization assays that make use of a ratiometric approach for detection and analysis.

  6. Facile semi-automated forensic body fluid identification by multiplex solution hybridization of NanoString® barcode probes to specific mRNA targets.

    Science.gov (United States)

    Danaher, Patrick; White, Robin Lynn; Hanson, Erin K; Ballantyne, Jack

    2015-01-01

    A DNA profile from the perpetrator does not reveal, per se, the circumstances by which it was transferred. Body fluid identification by mRNA profiling may allow extraction of contextual 'activity level' information from forensic samples. Here we describe the development of a prototype multiplex digital gene expression (DGE) method for forensic body fluid/tissue identification based upon solution hybridization of color-coded NanoString(®) probes to 23 mRNA targets. The method identifies peripheral blood, semen, saliva, vaginal secretions, menstrual blood and skin. We showed that a simple 5 min room temperature cellular lysis protocol gave equivalent results to standard RNA isolation from the same source material, greatly enhancing the ease-of-use of this method in forensic sample processing. We first describe a model for gene expression in a sample from a single body fluid and then extend that model to mixtures of body fluids. We then describe calculation of maximum likelihood estimates (MLEs) of body fluid quantities in a sample, and we describe the use of likelihood ratios to test for the presence of each body fluid in a sample. Known single source samples of blood, semen, vaginal secretions, menstrual blood and skin all demonstrated the expected tissue-specific gene expression for at least two of the chosen biomarkers. Saliva samples were more problematic, with their previously identified characteristic genes exhibiting poor specificity. Nonetheless the most specific saliva biomarker, HTN3, was expressed at a higher level in saliva than in any of the other tissues. Crucially, our algorithm produced zero false positives across this study's 89 unique samples. As a preliminary indication of the ability of the method to discern admixtures of body fluids, five mixtures were prepared. The identities of the component fluids were evident from the gene expression profiles of four of the five mixtures. Further optimization of the biomarker 'CodeSet' will be required

  7. Synthesis and characterization of magnetic cobalt ferrite nanoparticles covered with 3-aminopropyltriethoxysilane for use as hybrid material in nano technology; Sintese e caracterizacao de nanoparticulas magneticas de ferrita de cobalto recobertas por 3-aminopropiltrietoxissilano para uso como material hibrido em nanotecnologia

    Energy Technology Data Exchange (ETDEWEB)

    Camilo, Ruth Luqueze

    2006-07-01

    Nowadays with the appear of nano science and nano technology, magnetic nanoparticles have been finding a variety of applications in the fields of biomedicine, diagnosis, molecular biology, biochemistry, catalysis, etc. The magnetic functionalized nanoparticles are constituted of a magnetic nucleus, involved by a polymeric layer with active sites, which ones could anchor metals or selective organic compounds. These nanoparticles are considered organic inorganic hybrid materials and have great interest as materials for commercial applications due to the specific properties. Among the important applications it can be mentioned: magneto hyperthermia treatment, drugs delivery in specific local of the body, molecular recognition, biosensors, enhancement of nuclear magnetic resonance images quality, etc. This work was developed in two parts: 1) the synthesis of the nucleus composed by superparamagnetic nanoparticles of cobalt ferrite and, 2) the recovering of nucleus by a polymeric bifunctional 3-aminopropyltriethoxysilane. The parameters studied in the first part of the research were: pH, hydroxide molar concentration, hydroxide type, reagent order of addition, reagent way of addition, speed of shake, metals initial concentrations, molar fraction of cobalt and thermal treatment. In the second part it was studied: pH, temperature, catalyst type, catalyst concentration, time of reaction, relation ratios of H{sub 2}O/silane, type of medium and the efficiency of the recovering regarding to pH. The products obtained were characterized using the following techniques X-ray powder diffraction (DRX), transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), spectroscopy of scatterbrained energy spectroscopy (DES), atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA/DTGA), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and magnetization curves (VSM). (author)

  8. Dielectric Property Study of Zirconia/Nano-alumina Hybrid Polyimide Film%氧化锆复配纳米氧化铝杂化聚酰亚胺薄膜的介电性能研究

    Institute of Scientific and Technical Information of China (English)

    范勇; 韩笑笑; 陈昊; 杨瑞宵

    2013-01-01

      采用微乳化-热液法制备了一系列氧化锆(ZrO2)改性的纳米氧化铝分散液,然后用原位聚合法制备了相应的氧化锆复配纳米氧化铝杂化聚酰亚胺复合薄膜,并对其进行了TEM表征、电气强度和电导电流测试以及电老化阈值分析。结果表明:掺杂氧化锆复配纳米氧化铝的杂化聚酰亚胺复合薄膜的电气强度大幅提高,当ZrO2的掺杂量为7%时,电气强度达到最高为396.8 MV/m;其电导电流密度、电老化阈值均高于只掺杂纳米氧化铝的聚酰亚胺薄膜,且随ZrO2含量增加均出现先增大后减小的趋势。%A series of nano-alumina dispersed solution modified by zirconia were prepared by micro emul-sion-hydrothermal method, and a zirconia/nano-alumina hybrid polyimide(PI) film was prepared through in-situ polymerization method, and then the films were characterized by TEM, and its electric strength, conduction current density and electric degradation threshold were analyzed. The results show that the doping of zirconia/nano-alumina can increase the electric strength of the film. When the ZrO2 doping con-tent is 7%, the electric strength attain maximum which is 396.8 kV/mm. The conduction current density and electric degradation threshold of the zirconia/nano-alumina hybrid PI films are higher than that of the PI film doped by nano-alumina only, and they increase first and then decrease with the increase of ZrO2 content.

  9. 纳米锆-铝复合氧化物杂化聚酰亚胺耐电晕薄膜的研究%Study on Nano Zr-Al Composite Oxide Hybrid Polyimide Corona Resistant Films

    Institute of Scientific and Technical Information of China (English)

    范勇; 赵伟; 杨瑞宵; 陈昊; 张树龙

    2015-01-01

    采用微乳化-热液法制备了一系列经自制偶联剂处理的纳米锆-铝复合氧化物分散液,采用原位聚合法制备了纳米锆-铝复合氧化物杂化聚酰亚胺复合薄膜,对纳米分散液及复合薄膜的掺杂层进行透射电镜测试,并对复合薄膜的高温耐电晕性能、电气强度、力学性能进行测试及分析。结果表明:分散液中纳米粒子的尺寸达到纳米级,纳米锆-铝复合氧化物杂化PI薄膜的耐电晕性能大幅提高;在固定无机物掺杂量为22%,Zr与Al的物质的量之比为1.2∶9时,PI薄膜的耐电晕寿命达到10.35 h,电气强度达到274.91 MV/m,拉伸强度为146.4 MPa,断裂伸长率为43.0%。%A series of nano Zr-Al composite oxide dispersions were preprared by microemulsion-hydrother-mal method and treated with homemade coupling agent, and then nano Zr-Al complex oxide hybrid poly-imide composite films were prepared via in-situ polymerization. The nano-dispersion and doped layer of the composite films were tested by TEM, and the corona resistance at high temperature, electric strength, and mechanical properties of the composite films were tested and analyzed. The results show that the size of nanoparticles in dispersion reaches nanometer, and the corona resistance of the nano Zr-Al com-posite oxide hybrid PI films is greatly improved. When the doping amount of inorganic compounds is 22% and the molar ratio between Zr and Al is 1.2∶9, the corona resistance life of the hybrid PI film reaches 10.35 h, the electric strength reaches 274.91 MV/m, the tensile strength is 146.4 MPa, and the elongation at break is 43.0%.

  10. 耐电晕PI/无机纳米氧化物复合薄膜设计及性能%Preparation and corona resistant properties of nano-inorganic oxide hybrid PI films

    Institute of Scientific and Technical Information of China (English)

    陈昊; 范勇; 周宏; 杨瑞宵; 王春平; 韩笑笑

    2012-01-01

    The nano-dispersion of inorganic oxide is prepared by using the hydrothermal method and the water needed for the experiment is obtained from the process of the condensation reaction from alcohol into ether. The dispersion is composite with PI to make the inorganic nano-oxides hybrid PI films (PI/ Al2O3-SiO2 and PI/A12O3). As the sample is 25 fun in thickness, the test parameters are chosen as below; the waveform is bipolar square, wave pulse voltage is 2 500 V peak to peak, frequency is 20 kHz, and duty cycle is 50% , the test temperature is 155 X, ,the corona-resistant life of DuPont Kapton 100 CR film, PI/Al2O3-SiO2 film and PI/A12O3 films are measured respectively. The results show that the corona-resistance life of the modified nano-alumina hybrid PI films is the longest of all, which is more than 6 times as that of Kapton 100 CR films and 12 times more than that of the unmodified nano-alumina hybrid PI films. From the resulting SEM images, a conclusion can be made that the inorganic nano-composite structure of the modified nano-alumina hybrid PI films protects the PI substrate more effectively.%采用热液法制备了纳米无机氧化物分散液,其中水解所需的水由醇缩水成醚反应提供.所得的MTES改性的纳米氧化铝与聚酰亚胺复合制成杂化聚酰亚胺复合薄膜(PI/Al2O3 - SiO2),另外还制备了未改性的纳米氧化铝杂化聚酰亚胺复合薄膜(PI/Al2O3),在试样厚度均为25 μm的情况下,采用双极性脉冲方波电压、峰-峰值2500V、频率20 kHz、占空比50%、测试温度155℃的条件下,分别测试上述两种薄膜以及Kapton 100 CR薄膜的耐电晕时间,结果表明,PI/Al2O3 - SiO2薄膜的耐电晕寿命最长,是Kapton 100 CR薄膜的6倍以上,是PI/Al2O3薄膜的12倍以上.由SEM的测试结果分析表明,PI/Al2O3 - SiO2薄膜中的无机纳米复合结构可以更有效地保护PI基体,从而提高材料的耐电晕性.

  11. Modeling packed bed sorbent systems with the Pore Surface Diffusion Model: Evidence of facilitated surface diffusion of arsenate in nano-metal (hydr)oxide hybrid ion exchange media.

    Science.gov (United States)

    Dale, Sachie; Markovski, Jasmina; Hristovski, Kiril D

    2016-09-01

    This study explores the possibility of employing the Pore Surface Diffusion Model (PSDM) to predict the arsenic breakthrough curve of a packed bed system operated under continuous flow conditions with realistic groundwater, and consequently minimize the need to conduct pilot scale tests. To provide the nano-metal (hydr)oxide hybrid ion exchange media's performance in realistic water matrices without engaging in taxing pilot scale testing, the multi-point equilibrium batch sorption tests under pseudo-equilibrium conditions were performed; arsenate breakthrough curve of short bed column (SBC) was predicted by the PSDM in the continuous flow experiments; SBC tests were conducted under the same conditions to validate the model. The overlapping Freundlich isotherms suggested that the water matrix and competing ions did not have any denoting effect on sorption capacity of the media when the matrix was changed from arsenic-only model water to real groundwater. As expected, the PSDM provided a relatively good prediction of the breakthrough profile for arsenic-only model water limited by intraparticle mass transports. In contrast, the groundwater breakthrough curve demonstrated significantly faster intraparticle mass transport suggesting to a surface diffusion process, which occurs in parallel to the pore diffusion. A simple selection of DS=1/2 DP appears to be sufficient when describing the facilitated surface diffusion of arsenate inside metal (hydr)oxide nano-enabled hybrid ion-exchange media in presence of sulfate, however, quantification of the factors determining the surface diffusion coefficient's magnitude under different treatment scenarios remained unexplored.

  12. Chelating agent free-solid phase extraction (CAF-SPE) of Co(II), Cu(II) and Cd(II) by new nano hybrid material (ZrO{sub 2}/B{sub 2}O{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Yalcinkaya, Ozcan [Gazi University, Science Faculty, Department of Chemistry, 06500, Ankara (Turkey); Kalfa, Orhan Murat [Dumlupinar University, Science and Art Faculty, Department of Chemistry, 43100, Kuetahya (Turkey); Tuerker, Ali Rehber, E-mail: aturker@gazi.edu.tr [Gazi University, Science Faculty, Department of Chemistry, 06500, Ankara (Turkey)

    2011-11-15

    Highlights: {yields} A novel sorbent for solid phase extraction for the preconcentration of metal ions. {yields} Hybrid nano-scale ZrO{sub 2}/B{sub 2}O{sub 3} as a new SPE material. {yields} There is a no need for using any chelating agents before the preconcentration procedure. - Abstract: New nano hybrid material (ZrO{sub 2}/B{sub 2}O{sub 3}) was synthesized and applied as a sorbent for the separation and/or preconcentration of Co(II), Cu(II) and Cd(II) in water and tea leaves prior to their determination by flame atomic absorption spectrometry. Synthesized nano material was characterized by scanning electron microscope, transmission electron microscope and X-ray diffraction. The optimum conditions for the quantitative recovery of the analytes, including pH, eluent type and volume, flow rate of sample solution were examined. The effect of interfering ions was also investigated. Under the optimum conditions, adsorption isotherms and adsorption capacities have been examined. The recoveries of Co(II), Cu(II) and Cd(II) were 96 {+-} 3%, 95 {+-} 3%, 98 {+-} 4% at 95% confidence level, respectively. The analytical detection limits for Co(II), Cu(II), and Cd(II) were 3.8, 3.3, and 3.1 {mu}g L{sup -1}, respectively. The reusability and adsorption capacities (32.2 mg g{sup -1} for Co, 46.5 mg g{sup -1} for Cu and 109.9 mg g{sup -1} for Cd) of the sorbent were found as satisfactory. The accuracy of the method was confirmed by analyzing certified reference material (GBW-07605 Tea leaves) and spiked real samples. The method was applied for the determination of analytes in tap water and tea leaves.

  13. Preparation and Characterization of Ferrofluid Stabilized with Biocompatible Chitosan and Dextran Sulfate Hybrid Biopolymer as a Potential Magnetic Resonance Imaging (MRI T2 Contrast Agent

    Directory of Open Access Journals (Sweden)

    Tzu-Chen Yen

    2012-10-01

    Full Text Available Chitosan is the deacetylated form of chitin and used in numerous applications. Because it is a good dispersant for metal and/or oxide nanoparticle synthesis, chitosan and its derivatives have been utilized as coating agents for magnetic nanoparticles synthesis, including superparamagnetic iron oxide nanoparticles (SPIONs. Herein, we demonstrate the water-soluble SPIONs encapsulated with a hybrid polymer composed of polyelectrolyte complexes (PECs from chitosan, the positively charged polymer, and dextran sulfate, the negatively charged polymer. The as-prepared hybrid ferrofluid, in which iron chloride salts (Fe3+ and Fe2+ were directly coprecipitated inside the hybrid polymeric matrices, was physic-chemically characterized. Its features include the z-average diameter of 114.3 nm, polydispersity index of 0.174, zeta potential of −41.5 mV and iron concentration of 8.44 mg Fe/mL. Moreover, based on the polymer chain persistence lengths, the anionic surface of the nanoparticles as well as the high R2/R1 ratio of 13.5, we depict the morphology of SPIONs as a cluster because chitosan chains are chemisorbed onto the anionic magnetite surfaces by tangling of the dextran sulfate. Finally, the cellular uptake and biocompatibility assays indicate that the hybrid polymer encapsulating the SPIONs exhibited great potential as a magnetic resonance imaging T2 contrast agent for cell tracking.

  14. Interfacial chemistry and the design of solid-phase nucleic acid hybridization assays using immobilized quantum dots as donors in fluorescence resonance energy transfer.

    Science.gov (United States)

    Algar, W Russ; Krull, Ulrich J

    2011-01-01

    The use of quantum dots (QDs) as donors in fluorescence resonance energy transfer (FRET) offer several advantages for the development of multiplexed solid-phase QD-FRET nucleic acid hybridization assays. Designs for multiplexing have been demonstrated, but important challenges remain in the optimization of these systems. In this work, we identify several strategies based on the design of interfacial chemistry for improving sensitivity, obtaining lower limits of detection (LOD) and enabling the regeneration and reuse of solid-phase QD-FRET hybridization assays. FRET-sensitized emission from acceptor dyes associated with hybridization events at immobilized QD donors provides the analytical signal in these assays. The minimization of active sensing area reduces background from QD donor PL and allows the resolution of smaller amounts of acceptor emission, thus lowering the LOD. The association of multiple acceptor dyes with each hybridization event can enhance FRET efficiency, thereby improving sensitivity. Many previous studies have used interfacial protein layers to generate selectivity; however, transient destabilization of these layers is shown to prevent efficient regeneration. To this end, we report a protein-free interfacial chemistry and demonstrate the specific detection of as little as 2 pmol of target, as well as an improved capacity for regeneration.

  15. A Paper-Based Sandwich Format Hybridization Assay for Unlabeled Nucleic Acid Detection Using Upconversion Nanoparticles as Energy Donors in Luminescence Resonance Energy Transfer

    Directory of Open Access Journals (Sweden)

    Feng Zhou

    2015-09-01

    Full Text Available Bioassays based on cellulose paper substrates are gaining increasing popularity for the development of field portable and low-cost diagnostic applications. Herein, we report a paper-based nucleic acid hybridization assay using immobilized upconversion nanoparticles (UCNPs as donors in luminescence resonance energy transfer (LRET. UCNPs with intense green emission served as donors with Cy3 dye as the acceptor. The avidin functionalized UCNPs were immobilized on cellulose paper and subsequently bioconjugated to biotinylated oligonucleotide probes. Introduction of unlabeled oligonucleotide targets resulted in a formation of probe-target duplexes. A subsequent hybridization of Cy3 labeled reporter with the remaining single stranded portion of target brought the Cy3 dye in close proximity to the UCNPs to trigger a LRET-sensitized emission from the acceptor dye. The hybridization assays provided a limit of detection (LOD of 146.0 fmol and exhibited selectivity for one base pair mismatch discrimination. The assay was functional even in undiluted serum samples. This work embodies important progress in developing DNA hybridization assays on paper. Detection of unlabeled targets is achieved using UCNPs as LRET donors, with minimization of background signal from paper substrates owing to the implementation of low energy near-infrared (NIR excitation.

  16. Charge transfer in Li/CFx-silver vanadium oxide hybrid cathode batteries revealed by solid state 7Li and 19F nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Sideris, Paul J.; Yew, Rowena; Nieves, Ian; Chen, Kaimin; Jain, Gaurav; Schmidt, Craig L.; Greenbaum, Steve G.

    2014-05-01

    Solid state 7Li and 19F magic angle spinning nuclear magnetic resonance (MAS NMR) experiments are conducted on several cathodes containing CFx-Silver vanadium oxide (CFx-Ag2V4O11) hybrid cathodes discharged to 50% depth of discharge (DoD) and stored at their open-circuit voltage for a period of one and three months. Three carbonaceous sources for the CFx phase are investigated: petroleum coke-based, fibrous, and mixed fibrous. For each hybrid cathode, a measurable increase in the relative amount of lithium fluoride is observed after a three month resting period in both the 7Li and 19F NMR spectra. These changes are attributed to lithium ion migration from the silver vanadium oxide to the CFx phase during the resting period, and help clarify the mechanism behind high power handling capability of this cathode.

  17. Injectable In Situ Forming Hybrid Iron Oxide-Hyaluronic Acid Hydrogel for Magnetic Resonance Imaging and Drug Delivery

    NARCIS (Netherlands)

    Zhang, Y; Sun, Y.; Yang, X.; Hilborn, J.; Heerschap, A.; Ossipov, D.A.

    2014-01-01

    The development of multimodal in situ cross-linkable hyaluronic acid nanogels hybridized with iron oxide nanoparticles is reported. Utilizing a chemoselective hydrazone coupling reaction, the nanogels are converted to a macroscopic hybrid hydrogel without any additional reagent. Hydrophobic cargos r

  18. Note: Easy-to-maintain electron cyclotron resonance (ECR) plasma sputtering apparatus featuring hybrid waveguide and coaxial cables for microwave delivery.

    Science.gov (United States)

    Akazawa, Housei

    2016-06-01

    The branched-waveguide electron cyclotron resonance plasma sputtering apparatus places quartz windows for transmitting microwaves into the plasma source not in the line of sight of the target. However, the quartz windows must be replaced after some time of operation. For maintenance, the loop waveguide branching from the T-junction must be dismounted and re-assembled accurately, which is a time-consuming job. We investigated substituting the waveguide branches with two sets of coaxial cables and waveguide/coaxial cable converters to simplify assembly as far as connection and disconnection go. The resulting hybrid system worked well for the purposes of plasma generation and film deposition.

  19. Dispersive nanoSQUID magnetometry

    Science.gov (United States)

    Levenson-Falk, E. M.; Antler, N.; Siddiqi, I.

    2016-11-01

    We describe the theory and implementation of a dispersive magnetometer based on an aluminum nanoSQUID. The nanoSQUID consists of a superconducting loop interrupted by two variable-thickness weak-link nanobridge Josephson junctions. When the nanoSQUID is placed in parallel with a lumped-element capacitor, it acts as the inductive element in a resonant tank circuit. By performing microwave reflectometry on the circuit, the SQUID inductance can be measured, providing a sensitive meter of the flux threading the SQUID loop. In this review we provide the theoretical basis for the device, describe design and operation considerations, and present characterization results on several devices.

  20. Application of P-wave Hybrid Theory to the Scattering of Electrons from He+ and Resonances in He and H ion

    Science.gov (United States)

    Bhatia, A. K.

    2012-01-01

    The P-wave hybrid theory of electron-hydrogen elastic scattering [Phys. Rev. A 85, 052708 (2012)] is applied to the P-wave scattering from He ion. In this method, both short-range and long-range correlations are included in the Schroedinger equation at the same time, by using a combination of a modified method of polarized orbitals and the optical potential formalism. The short-correlation functions are of Hylleraas type. It is found that the phase shifts are not significantly affected by the modification of the target function by a method similar to the method of polarized orbitals and they are close to the phase shifts calculated earlier by Bhatia [Phys. Rev. A 69, 032714 (2004)]. This indicates that the correlation function is general enough to include the target distortion (polarization) in the presence of the incident electron. The important fact is that in the present calculation, to obtain similar results only a 20-term correlation function is needed in the wave function compared to the 220- term wave function required in the above-mentioned calculation. Results for the phase shifts, obtained in the present hybrid formalism, are rigorous lower bounds to the exact phase shifts. The lowest P-wave resonances in He atom and hydrogen ion have been calculated and compared with the results obtained using the Feshbach projection operator formalism [Phys. Rev. A, 11, 2018 (1975)]. It is concluded that accurate resonance parameters can be obtained by the present method, which has the advantage of including corrections due to neighboring resonances, bound states and the continuum in which these resonance are embedded.

  1. Preparation and characterization on nano-hybrid composite solid polymer electrolyte of PVdF-HFP /MG49-ZrO2 for battery application

    Science.gov (United States)

    Lee T., K.; Ahmad, A.; Hasyareeda, N.

    2014-09-01

    Initial study on nano composite polymer electrolyte of PVdF-HFP/MG49-ZrO2 has been done. The zirconium was synthesis via in-situ sol-gel method in a dissolved polymer blends. The effects of different concentrations of zirconium and pH values have been investigated on nano composite polymer (NCP). Analysis impedance show that only at 6 wt. % of zirconium for all pH values show a semi-circle arc which have lowest value of bulk resistance. No ionic conductivity value is obtain due to the absent of ion charge carriers. Analysis of XRD revealed that crystallinity phase of the nano composite polymer was affect by different pH values. However, no significant changes have been observed in IR bands. This could well indicate that different pH medium did not affect the chemical bonding in the structure.

  2. Preparation and characterization on nano-hybrid composite solid polymer electrolyte of PVdF-HFP /MG49-ZrO{sub 2} for battery application

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T. K.; Ahmad, A. [Polymer Research Center, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor D. E. Malaysia and School of Chemical Sciences and Food Technology, Faculty of Science and Technology (Malaysia); Hasyareeda, N. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology (Malaysia)

    2014-09-03

    Initial study on nano composite polymer electrolyte of PVdF-HFP/MG49-ZrO{sub 2} has been done. The zirconium was synthesis via in-situ sol-gel method in a dissolved polymer blends. The effects of different concentrations of zirconium and pH values have been investigated on nano composite polymer (NCP). Analysis impedance show that only at 6 wt. % of zirconium for all pH values show a semi-circle arc which have lowest value of bulk resistance. No ionic conductivity value is obtain due to the absent of ion charge carriers. Analysis of XRD revealed that crystallinity phase of the nano composite polymer was affect by different pH values. However, no significant changes have been observed in IR bands. This could well indicate that different pH medium did not affect the chemical bonding in the structure.

  3. Paper-based solid-phase multiplexed nucleic acid hybridization assay with tunable dynamic range using immobilized quantum dots as donors in fluorescence resonance energy transfer.

    Science.gov (United States)

    Noor, M Omair; Krull, Ulrich J

    2013-08-06

    A multiplexed solid-phase nucleic acid hybridization assay on a paper-based platform is presented using multicolor immobilized quantum dots (QDs) as donors in fluorescence resonance energy transfer (FRET). The surface of paper was modified with imidazole groups to immobilize two types of QD-probe oligonucleotide conjugates that were assembled in solution. Green-emitting QDs (gQDs) and red-emitting QDs (rQDs) served as donors with Cy3 and Alexa Fluor 647 (A647) acceptors. The gQD/Cy3 FRET pair served as an internal standard, while the rQD/A647 FRET pair served as a detection channel, combining the control and analytical test zones in one physical location. Hybridization of dye-labeled oligonucleotide targets provided the proximity for FRET sensitized emission from the acceptor dyes, which served as an analytical signal. Hybridization assays in the multicolor format provided a limit of detection of 90 fmol and an upper limit of dynamic range of 3.5 pmol. The use of an array of detection zones was designed to provide improved analytical figures of merit compared to that which could be achieved on one type of array design in terms of relative concentration of multicolor QDs. The hybridization assays showed excellent resistance to nonspecific adsorption of oligonucleotides. Selectivity of the two-plex hybridization assay was demonstrated by single nucleotide polymorphism (SNP) detection at a contrast ratio of 50:1. Additionally, it is shown that the use of preformed QD-probe oligonucleotide conjugates and consideration of the relative number density of the two types of QD-probe conjugates in the two-color assay format is advantageous to maximize assay sensitivity and the upper limit of dynamic range.

  4. Track-etch membranes as templates enabled nano/micro technology: a review

    Science.gov (United States)

    Chakarvarti, S. K.

    2009-06-01

    Many techniques are being used in order to synthesize nano-micro materials falling under the realm of nanotechnology. It need not be overemphasized that the miniaturization of devices and synthesis of new materials have a tremendous role in the development of powerful electronics as well as material based technologies in other areas but for the laws of quantum mechanics posing limitations besides the increasing cost and difficulties in manufacturing in such a small scale. The quest, therefore, for the alternative technologies, have stimulated a surge of interest in nano-meter scale materials and devices in the recent years. Metallic as well as semiconducting nano wires are the most attractive materials because of their unique properties having myriad of applications like interconnects for nano-electronics, magnetic devices, chemical and biosensors, whereas the hollow tubules are equally considered to be candidates for more potent applications — both in physical as well as biosciences. Materials' processing for nano-structured devices is indispensable to their rational design. The technique, known as "Template Synthesis", using electrochemical-electro less deposition is one of the most important processes for manufacturing nano-micro structures, nano-composites and devices and is relatively inexpensive and simple. The technique involves using membranes — ion crafted ones (popularly known as Particle Track-Etch Membranes or Nuclear Track Filters), alumite substrate membranes, besides other types of membranes as templates. The parameters viz., diameter as well as length i.e., aspect ratio, shape and wall surface traits in these membranes are controllable. In the present article a detailed review of this technique using track-etch membranes as templates in synthesis of nano-micro materials including hybrid materials and devices like field-ion emitters, resonant tunneling diodes (RTDs) etc. is presented including most of the results obtained in our laboratory.

  5. A hybrid fluorous monolithic capillary column with integrated nanoelectrospray ionization emitter for determination of perfluoroalkyl acids by nano-liquid chromatography-nanoelectrospray ionization-mass spectrometry/mass spectrometry.

    Science.gov (United States)

    Zhang, Haiyang; Ou, Junjie; Wei, Yinmao; Wang, Hongwei; Liu, Zhongshan; Zou, Hanfa

    2016-04-01

    A hybrid fluorous monolithic column was simply prepared via photo-initiated free radical polymerization of an acrylopropyl polyhedral oligomeric silsesquioxane (acryl-POSS) and a perfluorous monomer (2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl acrylate) in UV-transparent fused-silica capillaries within 5min. The physical characterization of hybrid fluorous monolith, including scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, mercury intrusion porosimetry (MIP) and nitrogen adsorption/desorption measurement was performed. Chromatographic performance was also evaluated by capillary liquid chromatography (cLC). Due to the fluorous-fluorous interaction between fluorous monolith and analytes, fluorobenzenes could well be separated, and the column efficiencies reached 86,600-92,500plates/m at the velocity of 0.87mm/s for alkylbenzenes and 51,900-76,000plates/m at the velocity of 1.10mm/s for fluorobenzenes. Meanwhile, an approach to integrate nanoelectrospray ionization (ESI) emitter with hybrid fluorous monolithic column was developed for quantitative determination of perfluoroalkyl acids by nanoHPLC-ESI-MS/MS. The integration design could minimize extracolumn volume, thus excluding undesirable peak broadening and improving separation performance.

  6. 聚酰亚胺/碳纳米管杂化薄膜电性能的研究%Electrical Properties of Polyimide/Carbon Nano-tube Hybrid Film

    Institute of Scientific and Technical Information of China (English)

    朱小影; 张明艳; 刁鹏鹤; 王文佳; 李晓东

    2011-01-01

    A kind of polyamide acid/carbon nano-tube hybrid liquid cement was fabricated by means of ultrasonic dispersion and in-situ polymerization.Then the polyimide/carbon nano-tube hybrid film was prepared according to filming technology.The surface morphology of the film was characterized by SEM.And the effects of incorporation of carbon nano-tube on the electrical property were researched.The results show that with the increase of CNTs content, the dielectric strength decreases gradually and has a sharp drop when the doped content is close to 0.6%, the dielectric constant and dielectric loss factor increase obviously.With the rise of test frequency, the dielectric constant declines slowly and the dielectric loss factor increases.The corona resistance time of the hybrid film is longer than that of pure polyimide.When the doped content of MWNTs is near to 0.38%, the time of corona resistance reaches a maximum of 10.2 h.%采用超声分散-原位聚合的方法制备聚酰胺酸/碳纳米管(CNTs)杂化胶液,并按一定成膜工艺制备出聚酰亚胺/碳纳米管杂化薄膜.利用扫描电子显微镜(SEM)对薄膜的表面形貌进行表征,讨论了碳纳米管的加入对杂化薄膜电性能的影响.结果表明:随着碳纳米管含量的增加,介电强度降低,介电常数与介质损耗因数均呈上升趋势,且随着测试频率的增加,介电常数缓慢下降,介质损耗因数增加;杂化薄膜的耐电晕性能均高于纯PI,且含量为0.38%时,耐电晕时间达到最大值10.2h.

  7. A comparative study on low cycle fatigue behaviour of nano and micro Al2O3 reinforced AA2014 particulate hybrid composites

    Science.gov (United States)

    Senthilkumar, R.; Arunkumar, N.; Manzoor Hussian, M.

    Aluminium based metal matrix composites have drawn more attraction due to their improved properties in structural applications for the past two decades. The fatigue behaviour of composite materials needs to be studied for their structural applications. In this work, powder metallurgy based aluminium (AA2014) alloy reinforced with micro and nano-sized alumina particles were fabricated and consolidated with the hot extrusion process. The evaluation of mechanical properties in the extruded composite was carried out. This composite was subjected to low cycle fatigue test with a constant strain rate. Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) images were used to evaluate the fatigue behaviour of aluminium-nano composite samples. Enhanced mechanical properties were exhibited by the nano alumina reinforced aluminium composites, when compared to the micron sized alumina reinforced composites. The failure cycle is observed to be higher for the nano alumina reinforced composites when compared with micron sized alumina composites due to a lower order of induced plastic strain.

  8. A comparative study on low cycle fatigue behaviour of nano and micro Al2O3 reinforced AA2014 particulate hybrid composites

    Directory of Open Access Journals (Sweden)

    R. Senthilkumar

    2015-01-01

    Full Text Available Aluminium based metal matrix composites have drawn more attraction due to their improved properties in structural applications for the past two decades. The fatigue behaviour of composite materials needs to be studied for their structural applications. In this work, powder metallurgy based aluminium (AA2014 alloy reinforced with micro and nano-sized alumina particles were fabricated and consolidated with the hot extrusion process. The evaluation of mechanical properties in the extruded composite was carried out. This composite was subjected to low cycle fatigue test with a constant strain rate. Scanning Electron Microscope (SEM and Transmission Electron Microscope (TEM images were used to evaluate the fatigue behaviour of aluminium-nano composite samples. Enhanced mechanical properties were exhibited by the nano alumina reinforced aluminium composites, when compared to the micron sized alumina reinforced composites. The failure cycle is observed to be higher for the nano alumina reinforced composites when compared with micron sized alumina composites due to a lower order of induced plastic strain.

  9. HDPE/纳米SiO2杂化材料的动态流变行为研究%The Study of the Dynamic Rheological Behavior of the HDPE/Nano-SiO2 Hybrid Materials

    Institute of Scientific and Technical Information of China (English)

    施海华; 周井隆; 龚方红; 熊煦; 刘春林; 陶国良

    2011-01-01

    Vinyl trimethoxysilane (VTMS) was grafted to the chain of the high density-polyethylene (HDPE) via melt grafting reaction. The tetraethoxysilane (TEOS) which acts as precursor was mixed with grafted HDPE,and then the HDPE/SiO2 hybrid materials were prepared by sol-gel process. The dynamic rheological behavior of the prepared high density-polyethylene/nano-silica hybrid composites was investigated by plate rheometer.Experimental results show that the complex viscosity (η*) of the composites increases with increasing the content of SiO2. When the SiO2 content of the hybrid composite reaches 1.2%, its complex viscosity η* increases suddenly and the shear thinning behavior appears. In the low frequency region, both the curves of the storage module G' vs. frequency ω and loss module G" vs. ω of the HDPE/SiO2 appear a second flat; and on the curve of the strain γ vs. storage module G', there appears two linear viscoelastic sections. These phenomena can be attributed to the links between the nano-SiO2 particles and polymer matrix in the hybrid system by chemical bonds and the uniform distribution of the nano-SiO2 particles; while when the nano-SiO2 content reaches 1.2%, the "solid-like" behavior may occur between the particles.%通过熔融接枝反应将乙烯基三甲氧基硅烷(VTMS)接枝到高密度聚乙烯(HDPE)分子链上,以四乙氧基硅烷(TEOS)为前驱体,加入接枝的HDPE中,通过溶胶-凝胶法(Sol-Gel)制备了HDPE/SiO2杂化材料,使用平板流变仪研究了纳米SiO2对HDPE/纳米SiO2杂化材料的动态流变行为的影响.结果表明,当SiO2含量达到1.2%时,复数黏度η*发生突变,并出现强烈的剪切变稀:低频区,储能模量G'、损耗模量G"出现第二平台;对应的应变y-G'曲线上,体系出现两段线性粘弹区域.这些现象表明由于杂化体系中纳米SiO2粒子与基体聚合物间通过化学键链接,并且均匀分布,在纳米粒子的含量达到1.2%时,粒子间就

  10. Monitoring DNA hybridization and thermal dissociation at the silica/water interface using resonantly enhanced second harmonic generation spectroscopy.

    Science.gov (United States)

    Azam, Md Shafiul; Gibbs-Davis, Julianne M

    2013-09-03

    The immobilization of oligonucleotide sequences onto glass supports is central to the field of biodiagnostics and molecular biology with the widespread use of DNA microarrays. However, the influence of confinement on the behavior of DNA immobilized on silica is not well understood owing to the difficulties associated with monitoring this buried interface. Second harmonic generation (SHG) is an inherently surface specific technique making it well suited to observe processes at insulator interfaces like silica. Using a universal 3-nitropyrolle nucleotide as an SHG-active label, we monitored the hybridization rate and thermal dissociation of a 15-mer of DNA immobilized at the silica/aqueous interface. The immobilized DNA exhibits hybridization rates on the minute time scale, which is much slower than hybridization kinetics in solution but on par with hybridization behavior observed at electrochemical interfaces. In contrast, the thermal dissociation temperature of the DNA immobilized on silica is on average 12 °C lower than the analogous duplex in solution, which is more significant than that observed on other surfaces like gold. We attribute the destabilizing affect of silica to its negatively charged surface at neutral pH that repels the hybridizing complementary DNA.

  11. Electromechanically Tunable Suspended Optical Nano-antenna

    OpenAIRE

    Chen, Kai; Razinskas, Gary; Feichtner, Thorsten; Grossmann, Swen; Christiansen, Silke; Hecht, Bert

    2016-01-01

    Coupling mechanical degrees of freedom with plasmonic resonances has potential applications in optomechanics, sensing, and active plasmonics. Here we demonstrate a suspended two-wire plasmonic nano-antenna acting like a nano-electrometer. The antenna wires are supported and electrically connected via thin leads without disturbing the antenna resonance. As a voltage is applied, equal charges are induced on both antenna wires. The resulting equilibrium between the repulsive Coulomb force and th...

  12. Speciation of As(III)/As(V) in water samples by a magnetic solid phase extraction based on Fe₃O₄/Mg-Al layered double hydroxide nano-hybrid followed by chemiluminescence detection.

    Science.gov (United States)

    Abdolmohammad-Zadeh, Hossein; Talleb, Zeynab

    2014-10-01

    A novel magnetic solid phase extraction method was developed for the speciation of As(III)/As(V) in aqueous solutions utilizing Fe3O4-doped Mg-Al layered double hydroxide (LDH) as a nano-sorbent. The method is based on the separation and pre-concentration of As(V) by Fe3O4/Mg-Al LDH nano-hybrid prior to determination by a chemiluminescence (CL) technique. The CL route involves the oxidation of luminol by vanadomolybdoarsenate heteropoly acid in a basic media. Since the existing cations cannot be adsorbed by positively charged layers of the LDH and other potentially interferent anions had no considerable effect on the CL reaction, it provides a very selective and sensitive determination approach for As(V). The determination of total arsenic and hence indirectly As(III) involve the pre-oxidation of As(III) to As(V) by a mixture of hydrogen peroxide and potassium hydroxide. Several factors affecting the extraction and determination of the analyte were investigated and optimized. Under optimum conditions, the calibration graph was linear in the range of 5.0-5000 ng L(-1). The limit of detection and enrichment factor was 2.0 ng L(-1) and 80, respectively. The method was validated by the analysis of a standard reference material (NIST SRM 1643e), and successfully applied to the speciation of arsenic in several water samples with recoveries in the range of 93.3-106.7% for the spiked samples.

  13. One-dimensional full wave treatment of mode conversion process at the ion-ion hybrid resonance in a bounded tokamak plasma

    Energy Technology Data Exchange (ETDEWEB)

    Monakhov, I.; Becoulet, A.; Fraboulet, D.; NGuyen, F

    1998-09-01

    A consistent picture of the mode conversion (MC) process at the ion-ion hybrid resonance in a bounded plasma of a tokamak is discussed, which clarifies the role of the global fast wave interference and cavity effects in the determination of the MC efficiency. This picture is supported by simulations with one-dimensional full wave kinetic code `VICE`. The concept of the `global resonator`, formed by the R = n{sup 2}{sub ||} boundary cutoffs [B. Saoutic et al., Phys. Rev. Lett. 76, 1647 (1996)], is justified, as well as the importance of a proper tunneling factor choice {eta}{sub cr} = 0.22 [A. K. Ram et al., Phys. Plasmas 3, 1976 (1996)]. The MC scheme behavior appears to be very sensitive to the MC layer position relative to the global wave field pattern, i.e. to the local value of `poloidal` electric field at the resonance. Optimal MC regimes are found to be attainable without requirement of a particular parallel wavenumber choice. (author) 40 refs.

  14. On-chip multiplexed solid-phase nucleic acid hybridization assay using spatial profiles of immobilized quantum dots and fluorescence resonance energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Noor, M. Omair; Tavares, Anthony J.; Krull, Ulrich J., E-mail: ulrich.krull@utoronto.ca

    2013-07-25

    Graphical abstract: -- Highlights: •Solid-phase multiplexed QD-FRET nucleic acid assay in electrokinetic fluidic chip. •Concurrent detection of two oligonucleotides based on channel length coverage. •Selection of “turn-on” and “turn-off” signals from two acceptor dyes and two colors of immobilized QDs, respectively. •No loss in assay sensitivity when implementing multiplexed assay format. -- Abstract: A microfluidic based solid-phase assay for the multiplexed detection of nucleic acid hybridization using quantum dot (QD) mediated fluorescence resonance energy transfer (FRET) is described herein. The glass surface of hybrid glass-polydimethylsiloxane (PDMS) microfluidic channels was chemically modified to assemble the biorecognition interface. Multiplexing was demonstrated using a detection system that was comprised of two colors of immobilized semi-conductor QDs and two different oligonucleotide probe sequences. Green-emitting and red-emitting QDs were paired with Cy3 and Alexa Fluor 647 (A647) labeled oligonucleotides, respectively. The QDs served as energy donors for the transduction of dye labeled oligonucleotide targets. The in-channel assembly of the biorecognition interface and the subsequent introduction of oligonucleotide targets was accomplished within minutes using a combination of electroosmotic flow and electrophoretic force. The concurrent quantification of femtomole quantities of two target sequences was possible by measuring the spatial coverage of FRET sensitized emission along the length of the channel. In previous reports, multiplexed QD-FRET hybridization assays that employed a ratiometric method for quantification had challenges associated with lower analytical sensitivity arising from both donor and acceptor dilution that resulted in reduced energy transfer pathways as compared to single-color hybridization assays. Herein, a spatial method for quantification that is based on in-channel QD-FRET profiles provided higher analytical

  15. EPDM/POSS 纳米杂化材料防火性能及力学性能的研究%Study on Fire Behavior and Mechanical Properties of EPDM/POSS Nano-hybrid Material

    Institute of Scientific and Technical Information of China (English)

    谭莲影; 程志; 穆洪帅; 朱田鑫; 苏韧伟

    2016-01-01

    EPDM/POSS nano-hybrid material was prepared using EPDM as raw rubber material, octavinyl-polyhedral oligomeric silsesquioxane (OVP)and intumescent flame retardant system (IFR) as additives,and the thermal properties,smoke properties and mechanical properties were tested by TGA,cone calorimetry and smoke density etc..The results showed that,compared to the pure EPDM material,adding OVP could effectively increase the thermal stability,flame retarding ability and me-chanical properties of the EPDM/POSS nano-hybrid material.When the amount of OVP was just 3phr,the thermal decomposition temperature was increased by 27.5°,while the peak HRR value was lowered by 9.2%.Besides,the tensile strength was strengthened by 26.5%,smoke density decreased as well.All these observations illustrated that OVP could significantly improve the comprehensive properties of the EPDM/POSS nano-hybird material.%以三元乙丙橡胶(EPDM)为原料,笼形八乙烯基硅倍半氧烷(OVP)及膨胀阻燃体系(IFR)为添加剂,制备了 EPDM/POSS 纳米杂化材料,并使用热重分析仪、锥形量热仪及烟密度箱等测试了其热性能、烟火性能及力学性能。结果表明,与纯 EPDM 胶料相比,添加了 OVP 的 EPDM/POSS 杂化材料的热稳定性、阻燃性能及力学性能均有所提升,当 OVP 加入3份时,起始热分解温度提高27.5℃,峰值热释放速率降低9.2%,拉伸强度提高26.5%,烟密度显著降低,说明 OVP 可提升 EPDM/POSS 杂化材料的综合性能。

  16. Comparison of gold- and graphene-based resonant nano-structures for terahertz metamaterials and an ultra-thin graphene-based modulator

    CERN Document Server

    Shen, Nian-Hai; Koschny, Thomas; Soukoulis, Costas M

    2014-01-01

    Graphene exhibits unique material properties and in electromagnetic wave technology, it raises the prospect of devices miniaturized down to the atomic length scale. Here we study split-ring resonator metamaterials made from graphene and we compare them to gold-based metamaterials. We find that graphene's huge reactive response derived from its large kinetic inductance allows for deeply subwavelength resonances, although its resonance strength is reduced due to higher dissipative loss damping and smaller dipole coupling. Nevertheless, tightly stacked graphene rings may provide for negative permeability and the electric dipole resonance of graphene meta-atoms turns out to be surprisingly strong. Based on these findings, we present a terahertz modulator based on a metamaterial with a multi-layer stack of alternating patterned graphene sheets separated by dielectric spacers. Neighbouring graphene flakes are biased against each other, resulting in modulation depths of over 75% at a transmission level of around 90%...

  17. The Shortening of MWNT-SPION Hybrids by Steam Treatment Improves Their Magnetic Resonance Imaging Properties In Vitro and In Vivo.

    Science.gov (United States)

    Cabana, Laura; Bourgognon, Maxime; Wang, Julie T-W; Protti, Andrea; Klippstein, Rebecca; de Rosales, Rafael T M; Shah, Ajay M; Fontcuberta, Josep; Tobías-Rossell, Ester; Sosabowski, Jane K; Al-Jamal, Khuloud T; Tobias, Gerard

    2016-06-01

    Carbon nanotubes (CNTs) have been advocated as promising nanocarriers in the biomedical field. Their high surface area and needle-like shape make these systems especially attractive for diagnostic and therapeutic applications. Biocompatibility, cell internalization, biodistribution, and pharmacokinetic profile have all been reported to be length dependent. In this study, further insights are gotten on the role that the length of CNTs plays when developing novel contrast agents for magnetic resonance imaging (MRI). Two samples of CNTs with different length distribution have been decorated with radio-labeled iron oxide nanoparticles. Despite characterization of the prepared hybrids reveals a similar degree of loading and size of the nanoparticles for both samples, the use of short CNTs is found to enhance the MRI properties of the developed contrast agents both in vitro and in vivo compared to their long counterparts.

  18. Four-wave mixing signal enhancement and optical bistability of a hybrid metal nanoparticle-quantum dot molecule in a nanomechanical resonator.

    Science.gov (United States)

    Li, Jian-Bo; Liang, Shan; Xiao, Si; He, Meng-Dong; Kim, Nam-Chol; Chen, Li-Qun; Wu, Gui-Hong; Peng, Yu-Xiang; Luo, Xiao-Yu; Guo, Ze-Ping

    2016-02-08

    We investigate theoretically four-wave mixing (FWM) response and optical bistability (OB) in a hybrid nanosystem composed of a metal nanoparticle (MNP) and a semiconductor quantum dot (SQD) coupled to a nanomechanical resonator (NR). It is shown that the FWM signal is enhanced by more than three orders of magnitude as compared to that of the system without exciton-phonon interaction, and the FWM signal can also be suppressed significantly and broadened due to the exciton-plasmon interaction. As the MNP couples strongly with the SQD, the bistable FWM response can be achieved by adjusting the SQD-MNP distance and the pumping intensity. For a given pumping constant and a fixed SQD-MNP distance, the enhanced exciton-phonon interaction can promote the occurrence of bistability. Our findings not only present a feasible way to detect the spacing between two nanoparticles, but also hold promise for developing quantum switches and nanoscale rulers.

  19. Scattering properties of vein induced localized surface plasmon resonances on a gold disk

    KAUST Repository

    Amin, Muhammad

    2011-12-01

    It is demonstrated via simulations that a gold nano-disk with a non-concentric cavity supports localized surface plasmon resonances over a frequency band that includes the visible and the near-infrared parts of the spectrum. The charge distribution on the disk indicates that the two distinct peaks in the scattering cross section are due to the (hybridized) higher-order plasmon modes; plasmon hybridization that involves the dipole modes of the disk and the cavity enforces the "coupling" of the plane-wave excitation to the originally-dark higher-order modes. It is further demonstrated that the resonance frequencies can be tuned by varying the radius of the embedded non-concentric cavity. The near-field enhancement observed at these two tunable resonance frequencies suggests that the proposed structure can be used as a substrate in surface enhanced spectroscopy applications. © 2011 IEEE.

  20. Control Strategies, Robustness Analysis, Digital Simulation and Practical Implementation for a Hybrid APF with a Resonant Ac-link

    Directory of Open Access Journals (Sweden)

    Chen Chen

    2010-12-01

    Full Text Available This paper proposes a novel hybrid active power filter (HAPF topology based onthe cascaded connection of the AC-side capacitor and the third-order LCL-filter, which hasthe advantage of the conventional hybrid filter and the LCL-filter in terms of reduced dclinkvoltage and better switching ripple attenuation. The robust deadbeat control law isderived for the current loop, with special emphasis on robustness analysis. The stabilityand robustness analysis under parameter variations are presented for the converter-sidecurrent tracking scheme and the grid-side current tracking scheme. It is found that thestability margins obtained from the converter-side current tracking control scheme aregenerally higher than those obtained from the grid-side current tracking scheme. However,the converter-side current tracking scheme is sensitive to the variation of the dampingresistance, and it would impose additional parameter uncertainty on the control system andcomplicate the problem. Hence the grid-side current tracking scheme is implemented. Thesimulation results obtained from Matlab/Simulink are presented for verification, where theinductance variation and grid disturbance scenarios are also taken into consideration. Theeffectiveness of the proposed hybrid APF is substantially confirmed by the simulation andexperimental results.

  1. A paper-based resonance energy transfer nucleic acid hybridization assay using upconversion nanoparticles as donors and quantum dots as acceptors

    Energy Technology Data Exchange (ETDEWEB)

    Doughan, Samer; Uddayasankar, Uvaraj; Krull, Ulrich J., E-mail: ulrich.krull@utoronto.ca

    2015-06-09

    Highlights: • Covalent immobilization of upconversion nanoparticles on paper. • LRET-based label free DNA detection using quantum dots as acceptors. • Use of polyethylene glycol to eliminate non-specific adsorption of quantum dots. • Improved analytical performance compared to analogous assays. - Abstract: Monodisperse aqueous upconverting nanoparticles (UCNPs) were covalently immobilized on aldehyde modified cellulose paper via reduction amination to develop a luminescence resonance energy transfer (LRET)-based nucleic acid hybridization assay. This first account of covalent immobilization of UCNPs on paper for a bioassay reports an optically responsive method that is sensitive, reproducible and robust. The immobilized UCNPs were decorated with oligonucleotide probes to capture HPRT1 housekeeping gene fragments, which in turn brought reporter conjugated quantum dots (QDs) in close proximity to the UCNPs for LRET. This sandwich assay could detect unlabeled oligonucleotide target, and had a limit of detection of 13 fmol and a dynamic range spanning nearly 3 orders of magnitude. The use of QDs, which are excellent LRET acceptors, demonstrated improved sensitivity, limit of detection, dynamic range and selectivity compared to similar assays that have used molecular fluorophores as acceptors. The selectivity of the assay was attributed to the decoration of the QDs with polyethylene glycol to eliminate non-specific adsorption. The kinetics of hybridization were determined to be diffusion limited and full signal development occurred within 3 min.

  2. Spoof Plasmon Hybridization

    CERN Document Server

    Zhang, Jingjing; Luo, Yu; Shen, Xiaopeng; Maier, Stefan A; Cui, Tie Jun

    2016-01-01

    Plasmon hybridization between closely spaced nanoparticles yields new hybrid modes not found in individual constituents, allowing for the engineering of resonance properties and field enhancement capabilities of metallic nanostructure. Experimental verifications of plasmon hybridization have been thus far mostly limited to optical frequencies, as metals cannot support surface plasmons at longer wavelengths. Here, we introduce the concept of 'spoof plasmon hybridization' in highly conductive metal structures and investigate experimentally the interaction of localized surface plasmon resonances (LSPR) in adjacent metal disks corrugated with subwavelength spiral patterns. We show that the hybridization results in the splitting of spoof plasmon modes into bonding and antibonding resonances analogous to molecular orbital rule and plasmonic hybridization in optical spectrum. These hybrid modes can be manipulated to produce enormous field enhancements (larger than 5000) by tuning the separation between disks or alte...

  3. Hybrid InGaAsP-InP Mach-Zehnder Racetrack Resonator for Thermooptic Switching and Coupling Control.

    Science.gov (United States)

    Green, William; Lee, Reginald; Derose, Guy; Scherer, Axel; Yariv, Amnon

    2005-03-07

    An InGaAsP-InP optical switch geometry based on electrical control of waveguide-resonator coupling is demonstrated. Thermooptic tuning of a Mach-Zehnder interferometer integrated with a racetrack resonator is shown to result in switching with ON-OFF contrast up to 18.5 dB. The optical characteristics of this unique design enable a substantial reduction of the switching power, to a value of 26 mW in comparison with 40 mW for a conventional Mach-Zehnder interferometer switch. Modulation response measurements reveal a 3 dB bandwidth of 400 kHz and a rise time of 1.8 micros, comparing favorably with current state-of-the-art thermooptic switches.

  4. Conversion of Fe-rich waste sludge into nano-flake Fe-SC hybrid Fenton-like catalyst for degradation of AOII.

    Science.gov (United States)

    Kong, Lingjun; Zhu, Yuting; Liu, Mingxiang; Chang, Xiangyang; Xiong, Ya; Chen, Diyun

    2016-09-01

    Permanently increasing in the amount of sludge resulted in the serious environment burden. This work reports a novel carbothermal process for converting the Fe-rich waste sludge into cleaner nano-flake Fenton-like catalyst to relieve the crisis. The transformation of Fe species at different carbothermal temperature was evaluated by XRD analysis. SEM and XPS analyses were involved to characterize the morphology and chemical bonds of the catalysts. Results shown that the resulted catalyst carbonized at 800 °C (Fe-SC-800) was composed of Fe(0) and Fe3O4, performing nano-flake-like structure. The Fe-SC-800 has the highest catalytic activity in degradation of AOII in C0 = 200 mg/L. The efficiency achieves at 98% within 30 min at neutral pH, which is ascribed to the hydroxyl radical oxidation. Moreover, no iron is leached and the Fe-SC-800 could be recycled for three times at least. Thus, the Fe rich sludge could be reutilized as a valuable source for eco-friendly catalyst production, constituting an ecological way to manage these sludge wastes and eliminate the sludge and organic pollution to environment.

  5. Electrical wire explosion process of copper/silver hybrid nano-particle ink and its sintering via flash white light to achieve high electrical conductivity

    Science.gov (United States)

    Chung, Wan-Ho; Hwang, Yeon-Taek; Lee, Seung-Hyun; Kim, Hak-Sung

    2016-05-01

    In this work, combined silver/copper nanoparticles were fabricated by the electrical explosion of a metal wire. In this method, a high electrical current passes through the metal wire with a high voltage. Consequently, the metal wire evaporates and metal nanoparticles are formed. The diameters of the silver and copper nanoparticles were controlled by changing the voltage conditions. The fabricated silver and copper nano-inks were printed on a flexible polyimide (PI) substrate and sintered at room temperature via a flash light process, using a xenon lamp and varying the light energy. The microstructures of the sintered silver and copper films were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). To investigate the crystal phases of the flash-light-sintered silver and copper films, x-ray diffraction (XRD) was performed. The absorption wavelengths of the silver and copper nano-inks were measured using ultraviolet-visible spectroscopy (UV-vis). Furthermore, the resistivity of the sintered silver and copper films was measured using the four-point probe method and an alpha step. As a result, the fabricated Cu/Ag film shows a high electrical conductivity (4.06 μΩcm), which is comparable to the resistivity of bulk copper (1.68 μΩcm). In addition, the fabricated Cu/Ag nanoparticle film shows superior oxidation stability compared to the Cu nanoparticle film.

  6. Electrical wire explosion process of copper/silver hybrid nano-particle ink and its sintering via flash white light to achieve high electrical conductivity.

    Science.gov (United States)

    Chung, Wan-Ho; Hwang, Yeon-Taek; Lee, Seung-Hyun; Kim, Hak-Sung

    2016-05-20

    In this work, combined silver/copper nanoparticles were fabricated by the electrical explosion of a metal wire. In this method, a high electrical current passes through the metal wire with a high voltage. Consequently, the metal wire evaporates and metal nanoparticles are formed. The diameters of the silver and copper nanoparticles were controlled by changing the voltage conditions. The fabricated silver and copper nano-inks were printed on a flexible polyimide (PI) substrate and sintered at room temperature via a flash light process, using a xenon lamp and varying the light energy. The microstructures of the sintered silver and copper films were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). To investigate the crystal phases of the flash-light-sintered silver and copper films, x-ray diffraction (XRD) was performed. The absorption wavelengths of the silver and copper nano-inks were measured using ultraviolet-visible spectroscopy (UV-vis). Furthermore, the resistivity of the sintered silver and copper films was measured using the four-point probe method and an alpha step. As a result, the fabricated Cu/Ag film shows a high electrical conductivity (4.06 μΩcm), which is comparable to the resistivity of bulk copper (1.68 μΩcm). In addition, the fabricated Cu/Ag nanoparticle film shows superior oxidation stability compared to the Cu nanoparticle film.

  7. Towards Surface Plasmon Resonance biosensing combined with bioaffinity-assisted nano HILIC Liquid Chromatography / Time-of-flight Mass Spectrometry identification of Paralytic Shellfish Poisons

    NARCIS (Netherlands)

    Marchesini, G.R.; Hooijerink, H.; Haasnoot, W.; Buijs, J.; Campbell, K.; Elliott, C.T.; Nielen, M.W.F.

    2009-01-01

    The potential for coupling technologies to deliver new, improved forms of bioanalysis is still in its infancy. We review a number of examples in which coupling has been successful, with special emphasis on combining surface-plasmon-resonance biosensors with mass spectrometry. We give an overview of

  8. Preparation and application of comb-like fluorosilicon copolymer/nano silica hybrid%纳米SiO2杂化梳状氟硅共聚物的合成与性能研究

    Institute of Scientific and Technical Information of China (English)

    郝丽芬; 许伟; 安秋凤

    2015-01-01

    Comb- like perfluoroalkyl ester/trifluoropropyl/ethoxy silane containing polysiloxanes (FPFAS) in-termediate was prepared through hydrosilylation and ring- opening reaction, which was reacted with silica sols via in situ condensation to produce comb- like fluorosilicon copolymer/nano silica hybrid (FPFAS- SiO2). Super-hydrophobic cotton fabric with good soft handle and air permeability was fabricated via simple dip- coating method. IR, XPS, FESEM and contact angle tester were utilized to characterize its structure, morphology and application properties. The results indicated that the product had the due structure. Superhydrophobicity of the treated fabric was influenced by the particle diameter of nano silica. While mass concentration of the FP-FAS- SiO2 in ethyl acetate solution was 0.5%, water contact angle and rol- off angle on the treated fabric sur-face were 163.5° and 7°, respectively. The treated cotton fabric possessed favorable air permeability and soft-ness. A micro/nano multiscale composite film on the fiber surface could be clearly observed by FESEM.%用硅氢化加成和开环反应先制得梳状结构的全氟酯基/三氟丙基/硅乙氧基改性聚硅氧烷(FPFAS)中间体.然后利用硅乙氧基与硅溶胶间的原位缩合反应,制得了纳米SiO2梳状氟硅共聚物(FPFAS-SiO2).并用一步浸渍法处理棉织物构筑了兼具柔软、良好透气性的超疏水织物.用IR、XPS、FESEM、接触角测量仪等对产物结构、膜形貌及应用性能进行研究.结果表明,产物具有预期结构.纳米SiO2粒径影响织物的超疏水性能,当FPFAS-SiO2溶液用量为0.5%,整理后织物表面的水静态接触角和滚动角分别为163.5°和7°,具有良好的透气性和柔软性.FESEM可明显观察到纤维表面存在一层微/纳多尺度复合膜.

  9. Hilbert Transform based Quadrature Hybrid RF Photonic Coupler via a Micro-Resonator Optical Frequency Comb Source

    CERN Document Server

    Nguyen, Thach G; Chu, Sai T; Little, Brent E; Morandotti, Roberto; Mitchell, Arnan; Moss, David J

    2015-01-01

    We demonstrate a photonic RF Hilbert transformer for broadband microwave in-phase and quadrature-phase generation based on an integrated frequency optical comb, generated using a nonlinear microring resonator based on a CMOS compatible, high-index contrast, doped-silica glass platform. The high quality and large frequency spacing of the comb enables filters with up to 20 taps, allowing us to demonstrate a quadrature filter with more than a 5-octave (3 dB) bandwidth and an almost uniform phase response.

  10. Microwave absorption of a TiO2@PPy hybrid and its nonlinear dielectric resonant attenuation mechanism

    Science.gov (United States)

    Jiang, Wanchun; Wang, Yu; Xie, Aming; Wu, Fan

    2016-09-01

    We report on a high-performance electromagnetic absorption material (TiO2@PPy) developed via a facile in situ polymerization process, where lower than  -60 dB maximum absorption and 6.56 dB effective absorption bandwidth (lower than  -10 dB) can be obtained under low thickness. The excellent electromagnetic wave absorption ability is attributed to the synthetic effect of improved impedance matching and the dual loss mechanism, which originates from the polarization relaxations of dipoles induced by vacancy defects and a conductive network constructed by aerogels. An equivalent circuit model is established to explicate the nonlinear dielectric resonant attenuation mechanism.

  11. Restoration of Critical-Sized Defects in the Rabbit Mandible Using Autologous Bone Marrow Stromal Cells Hybridized with Nano-β-tricalcium Phosphate/Collagen Scaffolds

    Directory of Open Access Journals (Sweden)

    Xuehui Zhang

    2013-01-01

    Full Text Available Nano-β-tricalcium phosphate/collagen (n-β-TCP/Col is considered with good osteoconductivity. However, the therapeutic effectiveness of n-β-TCP/Col scaffolds in combination with autologous bone marrow stromal cells (BMSCs remains to be elucidated for the repair of critical-sized bone defects. In this study, we found that n-β-TCP/Col scaffolds exhibited high biocompatibility in vitro. The introduction of BMSCs expanded in vitro to the scaffolds dramatically enhanced their efficiency to restore critical-sized bone defects, especially during the initial stage after implantation. Collectively, these results suggest that autologous BMSCs in n-β-TCP/Col scaffolds have the potential to be applied in bone tissue engineering.

  12. Improving rate performance of LiFePO{sub 4} cathode materials by hybrid coating of nano-Li{sub 3}PO{sub 4} and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shi-Xi, E-mail: zhaosx@sz.tsinghua.edu.cn [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Ding, Hao; Wang, Yan-Chao [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Li, Bao-Hua [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Nan, Ce-Wen [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2013-07-25

    Highlights: •This paper reports an improved solid-state method which leads to a uniform coating. The influence of Li{sub 3}PO{sub 4} and carbon coating on the electrochemical performance of LiFePO{sub 4} was studied. •LiFePO{sub 4} coating with Li{sub 3}PO{sub 4} and carbon shows a higher capacity than pure carbon coating sample. •Results indicate that the surface structure has an important influence on the electrochemical performance of LiFePO{sub 4}. The addition of Li{sub 3}PO{sub 4} can decrease the interfacial resistance of Li FePO{sub 4}. -- Abstract: Li{sub 3}PO{sub 4} coating on the surface of LiFePO{sub 4} particles was prepared by direct dispersing LiFePO{sub 4} precursor in starch slurry with nano-Li{sub 3}PO{sub 4}. The existence of nano-Li{sub 3}PO{sub 4} was confirmed with X-ray powder diffraction (XRD). And the particle size and morphology were observed by scanning electron microscope (SEM) and transmission electron microscope analysis (TEM). The effects of the mixture coating on rate performance of LiFePO{sub 4} cathode vs Li anode at 25 °C was investigated. Li{sub 3}PO{sub 4} and carbon mixing coated LiFePO{sub 4} cathode materials exhibited markedly improved rate capability relative to bare carbon-coated LiFePO{sub 4}. Analyses on cell impedance showed that the Li{sub 3}PO{sub 4} coating decreased the interfacial impedance. Transmission electron microscope analysis, electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) were carried out to explain the reason of better rate performance by Li{sub 3}PO{sub 4} coating.

  13. Super-resolution Localization and Defocused Fluorescence Microscopy on Resonantly Coupled Single-Molecule, Single-Nanorod Hybrids.

    Science.gov (United States)

    Su, Liang; Yuan, Haifeng; Lu, Gang; Rocha, Susana; Orrit, Michel; Hofkens, Johan; Uji-i, Hiroshi

    2016-02-23

    Optical antennas made of metallic nanostructures dramatically enhance single-molecule fluorescence to boost the detection sensitivity. Moreover, emission properties detected at the optical far field are dictated by the antenna. Here we study the emission from molecule-antenna hybrids by means of super-resolution localization and defocused imaging. Whereas gold nanorods make single-crystal violet molecules in the tip's vicinity visible in fluorescence, super-resolution localization on the enhanced molecular fluorescence reveals geometrical centers of the nanorod antenna instead. Furthermore, emission angular distributions of dyes linked to the nanorod surface resemble that of nanorods in defocused imaging. The experimental observations are consistent with numerical calculations using the finite-difference time-domain method.

  14. Role of intensive milling in the processing of barium ferrite/magnetite/iron hybrid magnetic nano-composites via partial reduction of barium ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Molaei, M.J., E-mail: mj.molaee@merc.ac.ir [Materials and Energy Research Center, P.O. Box: 31787-316, Karaj (Iran, Islamic Republic of); Delft Chem Tech, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 136, 2628 BL Delft (Netherlands); Ataie, A.; Raygan, S. [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran (Iran, Islamic Republic of); Picken, S.J. [Delft Chem Tech, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 136, 2628 BL Delft (Netherlands)

    2015-03-15

    In this research a mixture of barium ferrite and graphite was milled for different periods of time and then heat treated at different temperatures. The effects of milling time and heat treatment temperature on the phase composition, thermal behavior, morphology and magnetic properties of the samples have been investigated using X-ray diffraction, differential thermal analysis, high resolution transmission electron microscopy and vibrating sample magnetometer techniques, respectively. X-ray diffraction results revealed that BaFe{sub 12}O{sub 19}/Fe{sub 3}O{sub 4} nanocomposites form after a 20 h milling due to the partial reduction of BaFe{sub 12}O{sub 19}. High resolution transmission electron microscope images of a 40 h milled sample showed agglomerated structure consisting of nanoparticles with a mean particle size of 30 nm. Thermal analysis of the samples via differential thermal analysis indicated that for un-milled samples, heat treatment up to 900 °C did not result in α-Fe formation, while for a 20 h milled sample heat treatment at 700 °C resulted in reduction process progress to the formation of α-Fe. Wustite was disappeared in an X-ray diffraction pattern of a heat treated sample at 850 °C, by increasing the milling time from 20 to 40 h. By increasing the milling time, the structure of heat treated samples becomes magnetically softer due to an increase in saturation magnetization and a decrease in coercivity. Saturation magnetization and coercivity of a sample milled for 20 h and heat treated at 850 °C were 126.3 emu/g and 149.5 Oe which by increasing the milling time to 40 h, alter to 169.1 emu/g and 24.3 Oe, respectively. High coercivity values of milled and heat treated samples were attributed to the nano-scale formed iron particles. - Graphical abstract: Display Omitted - Highlights: • Barium ferrite and graphite were treated mechano-thermally. • Increasing milling time increases reduction progress after heat treatment. • Composites

  15. Cavity spatial mode-locking and high controllability of radial output coupling for circular/square plasmonic nano-resonator lasers.

    Science.gov (United States)

    Chen, Xi; Huang, Yingyan; Ho, Seng-Tiong

    2015-02-01

    We proposed and investigated a novel output coupling scheme for a circular and a square plasmonic nano-ring laser based on a T-shaped radial coupler that is easier to realize than a tangential coupler. The amount of coupling efficiency is shown to be highly controllable from a few percent to tens of percents. This is due to the fact that the standing-wave lasing mode pattern will rotate to give the minimal cavity loss at the T-coupler's location, making the amount of output coupling surprisingly low and hence, controllable. For a non-circular cavity, other symmetry-breaking and geometry-induced scattering could result in separate mode-pattern locking. These give a few main ways to control and optimize the coupling efficiency: via widening/narrowing or rotating the T-coupler's waveguide, or, for the case of a non-circular cavity, via shifting the location of the T-coupler. We observed increased unidirectional lasing induced by either rotating the waveguide or shifting it (for non-circular cases). We simulated the coupling using Maxwell's equations based on the multi-level multi-electron FDTD (MLME-FDTD) method to realistically model the lasing and output coupling behaviors of such plasmonic semiconductor lasers.

  16. Nano-composite magnetic material embedded on TiO2 pillars to realize magneto-optical resonant guided mode gratings

    Science.gov (United States)

    Varghese, B.; Gamet, E.; Jamon, D.; Neveu, S.; Berthod, L.; Shavdina, O.; Reynaud, S.; Verrier, I.; Veillas, C.; Royer, F.

    2016-02-01

    Periodic structuration of magnetic material is a way to enhance the magneto-optical behavior of optical devices like isolators. It is useful to reduce the footprint of such integrated devices or to improve their features. However, the structuration and/or integration of efficient magnetic materials on photonic platforms is still a difficult problem, because classical magneto-optical materials require an annealing temperature as high as 700°C. A novel wafer-scale approach is to incorporate that material into an already structured template through a single step deposition at low temperature. Using the dip-coating method, a magneto-optical thin film (~300nm) of CoFe2O4 nanoparticles in silica matrix prepared by sol-gel technique was coated on a 1D and 2D TiO2 subwavelength gratings. Such gratings were realized by the patterning of TiO2 films obtained by a sol-gel process. It was confirmed by Scanning Electron Microscope images that the magneto-optical composite completely occupies the voids of the 2D structuration showing a good compatibility between both materials. This composite shows a specific Faraday rotation of about 200°cm-1 at 1,5μm for 1% of volume fraction of nanoparticles. Spectral studies of the transmission and the reflection of a 1D TiO2 grating filled with the MO composite have evidenced the presence of a guided-mode optical resonance at 1,55μm. The position of this resonance was confirmed by numerical simulations, as well as its quite low efficiency. Based on simulations results, one can conclude that an increase of the grating depth is required to improve the efficiency of the resonance.

  17. Microstructural Characterization and Wear Behavior of Nano-Boride Dispersed Coating on AISI 304 Stainless Steel by Hybrid High Velocity Oxy-Fuel Spraying Laser Surface Melting

    Science.gov (United States)

    Sharma, Prashant; Majumdar, Jyotsna Dutta

    2015-07-01

    The current study concerns the detailed microstructural characterization and investigation of wear behavior of nano-boride dispersed coating developed on AISI 304 stainless steel by high velocity oxy-fuel spray deposition of nickel-based alloy and subsequent laser melting. There is a significant refinement and homogenization of microstructure with improvement in microhardness due to laser surface melting (1200 VHN as compared to 945 VHN of as-sprayed and 250 VHN of as-received substrate). The high temperature phase stability of the as-coated and laser melted surface has been studied by differential scanning calorimeter followed by detailed phase analysis at room and elevated temperature. There is a significant improvement in wear resistance of laser melted surface as compared to as-sprayed and the as-received one due to increased hardness and reduced coefficient of friction. The mechanism of wear has been investigated in details. Corrosion resistance of the coating in a 3.56 wt pct NaCl solution is significantly improved (4.43 E-2 mm/year as compared to 5 E-1 mm/year of as-sprayed and 1.66 mm/year of as-received substrate) due to laser surface melting as compared to as-sprayed surface.

  18. Investigation of oxygen reduction and methanol oxidation reaction activity of PtAu nano-alloy on surface modified porous hybrid nanocarbon supports

    Science.gov (United States)

    Parambath Vinayan, Bhaghavathi; Nagar, Rupali; Ramaprabhu, Sundara

    2016-09-01

    We investigate the electrocatalytic activity of PtAu alloy nanoparticles supported on various chemically modified carbon morphologies towards oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). The surface-modification of graphene nanosheets (f-G), multi-walled carbon nanotubes (f-MWNTs) and (graphene nanosheets-carbon nanotubes) hybrid support (f-G-MWNTs) were carried out by soft functionalization method using a cationic polyelectrolyte poly-(diallyldimethyl ammonium chloride). The Pt and PtAu alloy nanoparticles were dispersed over chemically modified carbon supports by sodium-borohydride assisted modified polyol reduction method. The electrochemical performance of all electrocatalysts were studied by half- and full-cell proton exchange membrane fuel cell (PEMFC) measurements and PtAu/f-G-MWNTs catalyst comparatively yielded the best catalytic performance. PEMFC full cell measurements of PtAu/f-G-MWNTs cathode electrocatalyst yield a maximum power density of 319 mW cm-2 at 60 °C without any back pressure,which is 2.1 times higher than that of cathode electrocatalyst Pt on graphene support. The high ORR and MOR activity of PtAu/f-G-MWNTs electrocatalyst is due to the alloying effect and inherent beneficial properties of porous hybrid nanocarbon support.

  19. Plasmonic resonances in hybrid systems of aluminum nanostructured arrays and few layer graphene within the UV-IR spectral range.

    Science.gov (United States)

    González-Campuzano, Ricardo; Saniger, J M; Mendoza, Doroteo

    2017-09-15

    The size-controllable and ordered Al nanocavities and nanodomes arrays were synthesized by electrochemical anodization of aluminum using phosphoric acid, citric acid and mixture both acids. Few layer graphene (FLG) was transferred directly on top of Al nanostructures and their morphology were evaluated by Scanning Electron Microscopy. The interaction between FLG and the plasmonic properties of Al nanostructures arrays were investigated based on specular reflectivity in the UV-Vis-IR range and Raman Spectroscopy. We found that their optical reflectivity was dramatically reduced as compared with unstructured Al. At the same time pronounced reflectivity dips were detectable in the 200 nm-896 nm wavelength range, which were ascribed to plasmonic resonances. The plasmonic properties of these nanostructures do not exhibit evident changes by the presence of FLG in the UV-Vis range of the electromagnetic spectrum. By contrast, the Surface-Enhanced Raman Spectroscopy (SERS) of FLG was observed in nanocavities and nanodomes structures that result in an intensity increase of the characteristic G and 2D bands of FLG induced by the plasmonic properties of Al nanostructures. © 2017 IOP Publishing Ltd.

  20. High-frequency FeCoNiNbB-SiO{sub 2} nano-granular films with high resistivity and adjustable resonance frequency from 1.3 to 7.8 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bangmin; Wang, Guowei; Zhang, Feng; Xiao, Yuhua; Ge, Shihui [Lanzhou University, Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou (China)

    2009-11-15

    A series of (FeCoNiNbB){sub x}-(SiO{sub 2}){sub 1-x} nano-granular thin films were fabricated by magnetron sputtering with different oblique incidence angles {theta}. High-resolution transmission electron micrographs show that the films consist of amorphous CoFeM (M=Ni,Nb,B) alloy particles with diameter about 2 nm surrounded by amorphous SiO{sub 2} matrix. Excellent soft magnetic properties have been achieved with a variable in-plane uniaxial magnetic anisotropy field H{sub k0}, which increases monotonically with {theta} and x, and decreases with the composition of B in FeCoM. For one typical sample of x=0.63 with {theta}=30 , H{sub ch} and H{sub ce} are 4.2 Oe and 5.4 Oe, respectively, {rho} reaches 12.5 m {omega} cm and 4 {pi} M{sub s} and H{sub k0} are 5.70 kG s and 92 Oe, respectively, which lead to a high ferromagnetic resonance frequency f{sub r} of 2.2 GHz. Based on the analysis of experimental results, two sources for the origin of the magnetic anisotropy, namely anisotropic magnetic coupling and orientation order of atomic pairs, are suggested. (orig.)

  1. Science and art of synthesis and crafting of nano/microstructures and devices using ion-crafted templates: a review

    Science.gov (United States)

    Chakarvarti, S. K.

    2006-03-01

    The miniaturization of devices and synthesis of new materials have a tremendous role in the development of powerful electronics as well as material based technologies in other areas but for the laws of quantum mechanics posing limitations besides the increasing cost and difficulties in manufacturing at such a small scale. The quest, therefore, for the alternative technologies have stimulated a surge of interest in nano-meter scale materials and devices in the recent years. Metallic nano wires are the most attractive materials because of their unique properties having myriad applications like interconnects for nano-electronics, magnetic devices, chemical and biosensors, where as the hollow tubules are equally considered to be candidate for more potent applications- both in physical as well as biosciences. Materials' processing for nano-structured devices is indispensable to their rational design. The technique, known as "Template Synthesis", using electrochemical/electro less deposition is one of the most important processes for manufacturing nano/micro structures, nano-composites and devices and is relatively inexpensive and simple. The technique involves in using membranes- ion crafted ones (popularly known as Particle Track-Etch Membranes or Nuclear Track Filters), alumite substrate membranes, besides other types of membranes as templates. The parameters viz., diameter as well as length i.e., the aspect ratio, shape and wall surface traits in these membranes are controllable. In the present work, a detailed review of this technique, synthesis of nano/micro materials including hybrid materials and devices like field-ion emitters, resonant tunneling diodes (RTDs) etc. will be presented including most of the results obtained in our laboratory.

  2. Preparation and Crystallization Behaviors of Reactable Nano-SiO2/Polycaprolactone Hybrid Materials%可反应性纳米SiO2/聚己内酯杂化材料的制备和结晶性能研究

    Institute of Scientific and Technical Information of China (English)

    常海波; 马聪鹤; 李小红; 张普玉; 张治军

    2011-01-01

    Nano-SiO2/polycaprolactone hybrid materials were prepared with caprolactone and readable nano-SiO2 by in-situ polymerization. The interface structure formed in composite system and the crystallization behaviors of the hybrid material were investigated by means of fourier transformation infrared spectrometry ( FTIR ), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results indicate that the epoxy on the surface of nano-SiO2 was consumed during the polymerization process of PCL. The strong interfacial interaction between PCL and nano-SiO2 is created. Moreover, nano-SiO2 accelerates the crystallization of PCL and increases the crystallinity of PCL.%以己内酯和可反应性纳米二氧化硅为原料,在辛酸亚锡的催化作用下,原位制备了纳米SiO2/聚己内酯(PCL)杂化材料,利用红外光谱、热重分析仪和差示扫描量热仪对杂化材料的界面结构和结晶性能进行了研究.结果表明,纳米SiO2上的环氧基团在聚合过程中参与了反应,使纳米SiO2与PCL之间产生了强烈的界面作用,而且纳米SiO2的引入促进了PCL的结晶,增加了其结晶度.

  3. 3,3',5,5'-四甲基联苯胺与钼磷酸纳米晶分子杂化材料的合成与表征%Synthesis and Characterization of Nano-Crystals Molecular Hybrid Material with 3,3',5,5'-Tetramethylbenzidine and Molybdophosphate

    Institute of Scientific and Technical Information of China (English)

    吴莹; 闻荻江; 徐玲; 王振平

    2006-01-01

    以3,3',5,5'-四甲基联苯胺(TMB)与Keggin结构钼磷酸H3PMo12O40杂化,合成得到新型分子杂化材料,经元素分析及IR、ICP、XRD等手段表征,确定其分子结构为(TMB)3PMo12O40,TEM显示该分子杂化材料颗粒直径在40nm~60nm,分布均匀,属球形颗粒纳米晶,UV-vis和ESR谱证明(TMB)3PMo12O40分子杂化材料为电荷转移型超分子化合物,并具有显著的光敏性和电催化活性.%A novel nano-crystal molecular hybrid material has been synthesized with 3,3',5,5'-tetramethylbenzidine (short for TMB) and Keggin structure heteropoly acid H3PMo12O40. The formula of this hybrid material was characterized to be (TMB)3 PMo12O40. TEM images showed that the organic-inorganic hybrid material is a nano-crystal in size of 40~60nm. IR, UV-vis and ESR spectra indicate that there is strong electron interaction between TMB and molybdophosphate forming a charge-transfer supermolecule hybrid material, which shows significant photosensitive and electrocatalytic properties.

  4. Extended short-wavelength spectral response of organic/(silver nanoparticles/Si nanoholes nanocomposite films) hybrid solar cells due to localized surface plasmon resonance

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhixin [National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Xu, Ling, E-mail: xuling@nju.edu.cn [National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Zhang, Wengping; Ge, Zhaoyun; Xu, Jun [National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Su, Weining; Yu, Yao [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Ma, Zhongyuan; Chen, Kunji [National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China)

    2015-04-15

    Highlights: • The silver nanoparticles (AgNPs)/Si nanoholes (SiNHs) nanocomposite films were fabricated. • An enhancement of total absorption in the AgNPs/SiNHs nanocomposite films at the short wavelength was exhibited. • Prototype solar cell device with AgNPs exhibits an increase of the power conversion efficiency by a factor of 2–3. - Abstract: In this letter, we investigated spectral and opto-electronic conversion properties of the inorganic/organic hybrid cells by using silver nanoparticles (AgNPs)/Si nanoholes (SiNHs) nanocomposite films, which were fabricated by the modified metal-assisted electroless etching (EE) method. It was found that the optical absorption spectra of the films with AgNPs demonstrate a clear peak and show the enhancement of total absorption at the short wavelength. The results of current–voltage (I–V) measurements show that solar cells with AgNPs exhibit an increase of the power conversion efficiency by a factor of 2–3, in comparison with those of the samples without AgNPs. Moreover, higher external quantum efficiency (EQE) values in AgNPs-decorated solar cells were confirmed in the short-wavelength spectral region (400–700 nm), which were essential to achieve high-performance photovoltaic cells. We thought these were mainly attributed to the localized surface plasmon resonance (LSPR) effects and increased light scattering of AgNPs.

  5. PEGylated hybrid ytterbia nanoparticles as high-performance diagnostic probes for in vivo magnetic resonance and X-ray computed tomography imaging with low systemic toxicity.

    Science.gov (United States)

    Liu, Zhen; Pu, Fang; Liu, Jianhua; Jiang, Liyan; Yuan, Qinghai; Li, Zhengqiang; Ren, Jinsong; Qu, Xiaogang

    2013-05-21

    Novel nanoparticulate contrast agents with low systemic toxicity and inexpensive character have exhibited more advantages over routinely used small molecular contrast agents for the diagnosis and prognosis of disease. Herein, we designed and synthesized PEGylated hybrid ytterbia nanoparticles as high-performance nanoprobes for X-ray computed tomography (CT) imaging and magnetic resonance (MR) imaging both in vitro and in vivo. These well-defined nanoparticles were facile to prepare and cost-effective, meeting the criteria as a biomedical material. Compared with routinely used Iobitridol in clinic, our PEG-Yb2O3:Gd nanoparticles could provide much significantly enhanced contrast upon various clinical voltages ranging from 80 kVp to 140 kVp owing to the high atomic number and well-positioned K-edge energy of ytterbium. By the doping of gadolinium, our nanoparticulate contrast agent could perform perfect MR imaging simultaneously, revealing similar organ enrichment and bio-distribution with the CT imaging results. The super improvement in imaging efficiency was mainly attributed to the high content of Yb and Gd in a single nanoparticle, thus making these nanoparticles suitable for dual-modal diagnostic imaging with a low single-injection dose. In addition, detailed toxicological study in vitro and in vivo indicated that uniformly sized PEG-Yb2O3:Gd nanoparticles possessed excellent biocompatibility and revealed overall safety.

  6. Nano Materials

    Science.gov (United States)

    2007-03-01

    hard coatings: – Molecular sieves – Lubricant additive to engine oil – Reinforcing fillers for plastics and rubbers – Chromatographic carriers 32...nanomaterials, November 2006 NanoCeramics applications (PlasmaChem) • Lapping and polishing • Low temperature sintering • New Ceramic alloys • Ceramic-metal...Nanotechnology lectures: Henne van Heeren, enablingMNT, nanomaterials, November 2006 MoS2 nanospheres (1) (Apnano) • Common solid lubricants are layered

  7. Influence of Quantum Dot Concentration on Carrier Transport in ZnO:TiO2 Nano-Hybrid Photoanodes for Quantum Dot-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Francis S. Maloney

    2016-10-01

    Full Text Available Zinc oxide nanowire and titanium dioxide nanoparticle (ZnO:TiO2 NW/NP hybrid films were utilized as the photoanode layer in quantum dot-sensitized solar cells (QDSSCs. CdSe quantum dots (QDs with a ZnS passivation layer were deposited on the ZnO:TiO2 NW/NP layer as a photosensitizer by successive ion layer adsorption and reaction (SILAR. Cells were fabricated using a solid-state polymer electrolyte and intensity-modulated photovoltage and photocurrent spectroscopy (IMVS/PS was carried out to study the electron transport properties of the cell. Increasing the SILAR coating number enhanced the total charge collection efficiency of the cell. The electron transport time constant and diffusion length were found to decrease as more QD layers were added.

  8. Hybrid chitosan-ß-glycerol phosphate-gelatin nano-/micro fibrous scaffolds with suitable mechanical and biological properties for tissue engineering.

    Science.gov (United States)

    Lotfi, Marzieh; Bagherzadeh, Roohollah; Naderi-Meshkin, Hojjat; Mahdipour, Elahe; Mafinezhad, Asghar; Sadeghnia, Hamid Reza; Esmaily, Habibollah; Maleki, Masoud; Hasssanzadeh, Halimeh; Ghayaour-Mobarhan, Majid; Bidkhori, Hamid Reza; Bahrami, Ahmad Reza

    2016-03-01

    Scaffold-based tissue engineering is considered as a promising approach in the regenerative medicine. Graft instability of collagen, by causing poor mechanical properties and rapid degradation, and their hard handling remains major challenges to be addressed. In this research, a composite structured nano-/microfibrous scaffold, made from a mixture of chitosan-ß-glycerol phosphate-gelatin (chitosan-GP-gelatin) using a standard electrospinning set-up was developed. Gelatin-acid acetic and chitosan ß-glycerol phosphate-HCL solutions were prepared at ratios of 30/70, 50/50, 70/30 (w/w) and their mechanical and biological properties were engineered. Furthermore, the pore structure of the fabricated nanofibrous scaffolds was investigated and predicted using a theoretical model. Higher gelatin concentrations in the polymer blend resulted in significant increase in mean pore size and its distribution. Interaction between the scaffold and the contained cells was also monitored and compared in the test and control groups. Scaffolds with higher chitosan concentrations showed higher rate of cell attachment with better proliferation property, compared with gelatin-only scaffolds. The fabricated scaffolds, unlike many other natural polymers, also exhibit non-toxic and biodegradable properties in the grafted tissues. In conclusion, the data clearly showed that the fabricated biomaterial is a biologically compatible scaffold with potential to serve as a proper platform for retaining the cultured cells for further application in cell-based tissue engineering, especially in wound healing practices. These results suggested the potential of using mesoporous composite chitosan-GP-gelatin fibrous scaffolds for engineering three-dimensional tissues with different inherent cell characteristics.

  9. A Hybrid DE-RGSO-ELM for Brain Tumor Tissue Categorization in 3D Magnetic Resonance Images

    Directory of Open Access Journals (Sweden)

    K. Kothavari

    2014-01-01

    Full Text Available Medical diagnostics, a technique used for visualizing the internal structures and functions of human body, serves as a scientific tool to assist physicians and involves direct use of digital imaging system analysis. In this scenario, identification of brain tumors is complex in the diagnostic process. Magnetic resonance imaging (MRI technique is noted to best assist tissue contrast for anatomical details and also carries out mechanisms for investigating the brain by functional imaging in tumor predictions. Considering 3D MRI model, analyzing the anatomy features and tissue characteristics of brain tumor is complex in nature. Henceforth, in this work, feature extraction is carried out by computing 3D gray-level cooccurence matrix (3D GLCM and run-length matrix (RLM and feature subselection for dimensionality reduction is performed with basic differential evolution (DE algorithm. Classification is performed using proposed extreme learning machine (ELM, with refined group search optimizer (RGSO technique, to select the best parameters for better simplification and training of the classifier for brain tissue and tumor characterization as white matter (WM, gray matter (GM, cerebrospinal fluid (CSF, and tumor. Extreme learning machine outperforms the standard binary linear SVM and BPN for medical image classifier and proves better in classifying healthy and tumor tissues. The comparison between the algorithms proves that the mean and standard deviation produced by volumetric feature extraction analysis are higher than the other approaches. The proposed work is designed for pathological brain tumor classification and for 3D MRI tumor image segmentation. The proposed approaches are applied for real time datasets and benchmark datasets taken from dataset repositories.

  10. Controlling light emission performance with hybrid phase-change plasmonic crystals (Conference Presentation)

    Science.gov (United States)

    Kao, Tsung Sheng

    2016-09-01

    In this paper, we demonstrate a novel approach in which the lattice resonances are tunable in a hybrid plasmonic crystal incorporating the phase-change material Ge2Sb2Te5 (GST) as a 20-nm-thick layer sandwiched between a gold nanodisk array and a quartz substrate. Non-volatile tuning of lattice resonances over a range Δλ of about 500 nm is achieved experimentally via intermediate phase states of the GST layer. This work demonstrates the efficacy and ease of resonance tuning via GST in the near infrared, suggesting the possibility to design broadband non-volatile tunable devices for optical modulation, switching, sensing and nonlinear optical devices. Also, with different nanostructure designs, the constituent plasmonic resonators can be selectively excited, generating isolated near-field energy hot-spots with selective excitation under a monochromatic plane wave illumination. Unlike other proposed techniques, our method for energy hot-spot positioning is based on a quantitative control of the crystalline proportions of the phase-change thin film rather than the complicated manipulations of an incident light beam. This makes such a near-field energy controllable template much easier to be implemented. This near-field energy controllable system consists of gold nano-antennas with deep subwavelength spacing and an underlying GST thin layer. Such a hybrid plasmonic system is easy to be implemented and the nanoscale energy hot-spot can be positioned in a large field of view by extending the system with different plasmon resonators, suggesting a further step toward applications such as nano-imaging, bio-assay addressing and nano-circuitry.

  11. Nano-bio-sensing

    CERN Document Server

    Carrara, Sandro

    2011-01-01

    This book examines state-of-the-art applications of nano-bio-sensing. It brings together researchers from nano-electronics and bio-technology, providing multidisciplinary content from nano-structures fabrication to bio-sensing applications.

  12. Nano-TiO2 In-situ Hybrid Polyurethane Leather Coating with Enhanced Permeability%聚氨酯/纳米TiO2原位杂化涂层的制备及其通透性能研究

    Institute of Scientific and Technical Information of China (English)

    陈意; 石欢欢; 范浩军; 袁继新; 刘若望; 张才; 付善淼

    2009-01-01

    As polyurethane solution coagulated in wet phase inversion process,in-situ hydrolysis and condensation reactions of nano precursor were triggered synchronously to introduce nano-TiO2 into polyurethane synthetic leather coating.Water vapor and gas permeability of the hybrid coatings are found to increase with an increasing concentration of nano-TiO2,which is ex-plainod as voids formed at organic polymer-inorganic nano particle interface.The existence of such voids was proved in nitrogen adsorption/desorption experiment,by the determination of extra mesopores and higher specific surface area than predicted values.%在聚氨酯溶液湿法成膜的过程中引发前驱体的原位水解缩聚反应,成功地将纳米级TiO2颗粒均匀地引入聚氨酯合成革涂层中.低温氮吸附/脱附试验证明,在有机聚氨酯和无机纳米TiO2颗粒间形成了相间孔隙,这使得本试验所制备的聚氨酯/纳米TiO2原位杂化涂层具有明显提高的透气、透湿性.

  13. Insights into Nano- and Micron-Scale Phase Separation in Amorphous Solid Dispersions Using Fluorescence-Based Techniques in Combination with Solid State Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Purohit, Hitesh S; Ormes, James D; Saboo, Sugandha; Su, Yongchao; Lamm, Matthew S; Mann, Amanda K P; Taylor, Lynne S

    2017-07-01

    Miscibility between the drug and the polymer in an amorphous solid dispersion (ASD) is considered to be one of the most important factors impacting the solid state stability and dissolution performance of the active pharmaceutical ingredient (API). The research described herein utilizes emerging fluorescence-based methodologies to probe (im)miscibility of itraconazole (ITZ)-hydroxypropyl methylcellulose (HPMC) ASDs. The ASDs were prepared by solvent evaporation with varying evaporation rates and were characterized by steady-state fluorescence spectroscopy, confocal imaging, differential scanning calorimetry (DSC), and solid state nuclear magnetic resonance (ssNMR) spectroscopy. The size of the phase separated domains for the ITZ-HPMC ASDs was affected by the solvent evaporation rate. Smaller domains (30 nm) were found in ASDs prepared using slower evaporation rates. Confocal imaging provided visual confirmation of phase separation along with chemical specificity, achieved by selectively staining drug-rich and polymer-rich phases. ssNMR confirmed the results of fluorescence-based techniques and provided information on the size of phase separated domains. The fluorescence-based methodologies proved to be sensitive and rapid in detecting phase separation, even at the nanoscale, in the ITZ-HPMC ASDs. Fluorescence-based methods thus show promise for miscibility evaluation of spray-dried ASDs.

  14. Nano-ring arrays for sub-micron particle trapping

    Science.gov (United States)

    Han, Xue; Truong, Viet Giang; Nic Chormaic, Síle

    2017-04-01

    Plasmonic tweezers based on nano-ring arrays on gold thin film are demonstrated. A cylindrical surface plasmon resonance is generated in the aperture of a nano-ring and a transmission peak results. When nano-slits are included to connect the nano-rings, the transmission peak becomes narrower. When the size of the aperture of the nano-ring is reduced, this peak is red-shifted. Both 0.5 μm and 1 μm polystyrene particles are trapped successfully by nano-ring arrays. A self-induced back-action effect is observed when a red-shifted laser beam is used. With multiple trapping sites provided by the nano-ring array, this type of plasmonic tweezers has huge potential to be integrated in lab-on-a-chip systems for life sciences research.

  15. Nano CMOS

    Directory of Open Access Journals (Sweden)

    Malay Ranjan Tripathy

    2009-05-01

    Full Text Available Complementary metal-oxide-semiconductor (CMOS has become major challenge to scaling and integration. However, innovation in transistor structures and integration of novel materials are needed to sustain this performance trend. CMOS variability in the scaling technology becoming very important concern because of limitation of process control over statistical variability related to the fundamental discreteness of charge and matter. Different aspects responsible for device variability are discussed in this article. The challenges and opportunities of nano CMOS technology are outlined here.

  16. Preparation of PBMA/AA-SiO2 nano hybrid material using RAFT polymerization%RAFT 聚合制备 PBMA/AA-SiO2杂化纳米材料

    Institute of Scientific and Technical Information of China (English)

    王芳平; 张珺瑛; 李晚霞; 袁婷; 王其召; 俞洁; 杜新贞

    2013-01-01

    With bis[4-(methoxycarbonyl)benzyl]trithiocarbonate(CTA)as a chain transfer agent,butyl methacrylate(BMA)as monomer ,and functionalized silica modified by attaching AA group to the surface , PBMA/AA-SiO2 nano composite material was prepared using reversible addition-fragmentation chain transfer ( RAFT) polymerization.The structures and properties of PBMA/AA-SiO2 were characterized by FT-IR,TGA,GPC and TEM.These results showed that PBMA/AA-SiO2 hybrid microspheres of 22 nm in average diameters were obtained.TGA results revealed that the thermal stability of the hybrid material was very well ,and the graft-ing yield of PBMA on the SiO 2 was 19%.%以三硫代二[4-(甲氧羰基)苄基]碳酸酯为链转移剂( CTA),甲基丙烯酸丁酯( BMA)为单体,通过可逆加成-断裂链转移自由基聚合( RAFT)法修饰丙烯酸( AA)功能化的纳米二氧化硅( SiO2),制备了PBMA/AA-SiO2有机/无机杂化纳米材料。并通过FT-IR、GPC、TGA、TEM表征和分析了杂化材料的结构、分子量、SiO2纳米粒子在基体中的分散性以及杂化材料的热稳定性。结果表明,PBMA/AA-SiO2杂化微球粒径约为22 nm,分布均匀;TGA分析表明此杂化材料的热稳定性良好,PBMA接枝率为19%。

  17. 纳米粒子原位杂化酚醛/炭纤维烧蚀防热研究%Studies on ablative and heat-resistant properties of in-situ nano-hybrid PF/CF composite

    Institute of Scientific and Technical Information of China (English)

    刘乃亮; 齐暑华; 李春华; 理莎莎; 付东升

    2011-01-01

    SiC,SiO2 and A12O3 three nano-hybrid phenol formaldehyde resin (PF) were prepared by in-situ hybridization method, respectively. Scanning electron microscopy (SEM) observation showed that nanoparticles dispersed well in the composite and formed the "sea-island" structure with PF. Thermal gravity analysis (TG-DTG) demonstrated three stages in the process of PF thermal degradation,and the calculated results by Kissinger method illustrated that nanoparticles can reduce the thermal decomposition activation energy at the first stage and increase it at the second stage. Wear tests explained that nanoparticles can increase PF reinforced carbon fiber ( CF) composite wear property. Oxygen-acetylene ablation tests indicated that nanoparticles can increase the ablative resistance of PF/CF composite.%采用原位杂化方法分别制备了SiC、SiO2和Al2 O3 3种纳米粒子杂化酚醛树脂,扫描电镜观察发现,纳米粒子均匀分散在酚醛树脂中,与酚醛树脂形成“海-岛”结构;热重分析结果显示,纳米粒子杂化酚醛树脂的降解过程分为3个阶段,通过Kissinger法对杂化酚醛树脂热分解活化能进行计算,发现纳米粒子能够降低树脂第1阶段的热分解活化能,而提高了树脂在第2阶段的热分解活化能;磨耗性能测试显示纳米粒子可提高酚醛树脂/炭纤维耐磨性能;氧—乙炔烧蚀法测试表明,纳米粒子能提高酚醛树脂/炭纤维复合材料的耐烧蚀性能.

  18. NANO PARÇACIKLAR VE NANO TELLER

    OpenAIRE

    Hakan ATEŞ

    2015-01-01

    Bu makale nano parçacık ve nano tellerin sentezi, yapısı ve geniş bir alanda özelliklerinin yanı sıra nano teknoloji hakkında da bir irdelemeyi sunmaktadır. Çalışma nano teknoloji ve malzemeleri tanımlamakta ve kısa bir tarih, üretim teknikleri ve uygulama alanları hakkında bilgi vermektedir.

  19. Co-hydrothermal synthesis of LiMn23/24Mg1/24PO4·LiAlO2/C nano-hybrid cathode material with enhanced electrochemical performance for lithium-ion batteries

    Science.gov (United States)

    Zhang, Jun; Luo, Shaohua; Chang, Longjiao; Hao, Aimin; Wang, Zhiyuan; Liu, Yanguo; Xu, Qian; Wang, Qing; Zhang, Yahui

    2017-02-01

    LiMn23/24Mg1/24PO4·LiAlO2/C is synthesized by a co-hydrothermal method in water/PEG system using Li2CO3, AAO and Mn1-xMgxPO4 as raw material. The electronic structure and micromorphology of multi-component compound LiMn1-xMgxPO4/C (x = 0, 1/24, 1/12, 1/6) and nano-hybrid LiMn23/24Mg1/24PO4·LiAlO2/C cathode materials are studied by first-principles calculation and experimental research including XRD, SEM, TEM. The calculated band gap of LiMn23/24Mg1/24PO4/C is 2.296 eV, which is lower than other percentages Mg2+ doping samples. Electrochemical tests exhibit LiMn23/24Mg1/24PO4/C has better cycling performance and rate capability than other contents Mg2+ doping samples with the discharge capacity of 143.5 mAh/g, 141.5 mAh/g, 139.2 mAh/g and 136.3 mAh/g at 0.05C, 0.1C, 0.5C and 1C in order. After compositing and preparation of LiMn23/24Mg1/24PO4·LiAlO2/C composite material by co-hydrothermal route, the initial discharge capacity reaches up to 151.8 mAh/g, which suggests that co-modified with Mg2+ doping and LiAlO2 compositing material can improve the electronic conductivity of LiMnPO4/C by facilitating the lithium ion diffusion rate in the interior of the materials.

  20. Micro and nano-biomimetic structures for cell migration study fabricated by hybrid subtractive and additive 3D femtosecond laser processing

    Science.gov (United States)

    Sima, Felix; Serien, Daniela; Wu, Dong; Xu, Jian; Kawano, Hiroyuki; Midorikawa, Katsumi; Sugioka, Koji

    2017-02-01

    Lab-on-a-chip devices have been intensively developed during the last decade when emerging technologies offered possibilities to manufacture reliable devices with increased spatial resolution. These biochips allowed testing chemical reactions in nanoliter volumes with enhanced sensitivity and lower consumption of reagents. There is space to further consolidate biochip assembling processing since the new technologies attempt direct fabrication in view of reducing costs and time by increasing efficiency and functionalities. Rapid prototyping by ultrafast lasers which induces local modifications inside transparent materials of both glass and polymers with high precision at micro- and nanoscale is a promising tool for fabrication of such biochips. We have developed a new technology by combining subtractive ultrafast laser assisted chemical etching of glasses and additive two-photon polymerization to integrate 3D glass microfluidics and polymer microcomponents in a single biochip. The innovative hybrid "ship-in-a-bottle" approach is not only an instrument that can tailor 3D environments but also a tool to fabricate biomimetic in vivo structures inside a glass microfluidic chip. It was possible to create appropriate environment for cell culturing and to offer robustness and transparency for optical interrogation. Cancer cells were cultivated inside biochips and monitored over short and long periods. With the view of understanding cancer cells specific behavior such as migration or invasiveness inside human body, introduction of different geometrical configurations and chemical conditions were proposed. The cells were found responsive to a gradient of nutrient concentration through the microchannels of a 3D polymeric scaffold integrated inside glass biochip.

  1. Raman scattering enhancement in photon-plasmon resonance mediated metal-dielectric microcavity

    Science.gov (United States)

    Guddala, Sriram; Dwivedi, Vindesh K.; Vijaya Prakash, G.; Narayana Rao, D.

    2013-12-01

    Here, we report the photon-plasmon interaction scheme and enhanced field strengths resulted into the amplification of phonon in a novel microcavity. A metal-dielectric microcavity, with unified cavity photonic mode and localized surface plasmon resonances, is visualized by impregnating the gold nanoparticles into the deep see-through nano-sized pores of porous silicon microcavity. The intense optical field strengths resulting from the photon-plasmon interactions are probed by both resonant and non-resonant Raman scattering experiments. Due to photon-plasmon-phonon interaction mechanism, several orders of enhancement in the intensity of scattered Raman Stokes photon (at 500 cm-1) are observed. Our metal nanoparticle-microcavity hybrid system shows the potential to improve the sensing figure of merit as well as the applications of plasmonics for optoelectronics, photovoltaics, and related technologies.

  2. Raman scattering enhancement in photon-plasmon resonance mediated metal-dielectric microcavity

    Energy Technology Data Exchange (ETDEWEB)

    Guddala, Sriram; Narayana Rao, D., E-mail: dnr.laserlab@gmail.com, E-mail: dnrsp@uohyd.ernet.in [School of Physics, University of Hyderabad, Hyderabad 500 046 (India); Dwivedi, Vindesh K.; Vijaya Prakash, G. [Nanophotonics Laboratory, Department of Physics, IIT Delhi, New Delhi 110 016 (India)

    2013-12-14

    Here, we report the photon-plasmon interaction scheme and enhanced field strengths resulted into the amplification of phonon in a novel microcavity. A metal-dielectric microcavity, with unified cavity photonic mode and localized surface plasmon resonances, is visualized by impregnating the gold nanoparticles into the deep see-through nano-sized pores of porous silicon microcavity. The intense optical field strengths resulting from the photon-plasmon interactions are probed by both resonant and non-resonant Raman scattering experiments. Due to photon-plasmon-phonon interaction mechanism, several orders of enhancement in the intensity of scattered Raman Stokes photon (at 500 cm{sup −1}) are observed. Our metal nanoparticle-microcavity hybrid system shows the potential to improve the sensing figure of merit as well as the applications of plasmonics for optoelectronics, photovoltaics, and related technologies.

  3. Pure Nano-Rotation Scanner

    Directory of Open Access Journals (Sweden)

    Moo-Yeon Lee

    2012-01-01

    Full Text Available We developed and tested a novel rotation scanner for nano resolution and accurate rotary motion about the rotation center. The scanner consists of circular hinges and leaf springs so that the parasitic error at the center of the scanner in the X and Y directions is minimized, and rotation performance is optimized. Each sector of the scanner's system was devised to have nano resolution by minimizing the parasitic errors of the rotation center that arise due to displacements other than rotation. The analytic optimal design results of the proposed scanner were verified using finite element analyses. The piezoelectric actuators were used to attain nano-resolution performances, and a capacitive sensor was used to measure displacement. A feedback controller was used to minimize the rotation errors in the rotation scanner system under practical conditions. Finally, the performance evaluation test results showed that the resonance frequency was 542 Hz, the resolution was 0.09 μrad, and the rotation displacement was 497.2 μrad. Our test results revealed that the rotation scanner exhibited accurate rotation about the center of the scanner and had good nano precision.

  4. 溶胶-凝胶法制备有机/无机纳米杂化涂料的现状及展望%Current Status and Prospect of Sol-Gel Method in Preparing Organic - Inorganic Hybrid Nano- Paints

    Institute of Scientific and Technical Information of China (English)

    张浩; 王笛

    2013-01-01

    溶胶-凝胶法制备的有机/无机纳米杂化涂料具有许多优点.介绍了溶胶-凝胶法制备有机/无机纳米杂化涂料的研究现状,并对此作出了展望.%A review was provided of the current status of research on fabricating organic - inorganic hybrid nano - paints by sol - gel method. It was pointed out that sol-gel method as a new method for preparing organic - inorganic hybrid materials had a variety of advantages. Furthermore, suggestions were also given about the development trend of sol-gel method.

  5. Resonant metallic nanostructures for enhanced terahertz spectroscopy

    KAUST Repository

    Toma, A.

    2015-11-12

    We present our recent studies on terahertz resonant dipole nanoantennas. Exploiting the localization and enhancement capabilities of these devices, we introduce an effective method to perform terahertz spectroscopy on an extremely small number of nano-objects.

  6. Nanostructured Fiber Optic Cantilever Arrays and Hybrid MEMS Sensors for Chemical and Biological Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advancements in nano-/micro-scale sensor fabrication and molecular recognition surfaces offer promising opportunities to develop miniaturized hybrid fiber optic and...

  7. Fundamentals of nanomechanical resonators

    CERN Document Server

    Schmid, Silvan; Roukes, Michael Lee

    2016-01-01

    This authoritative book introduces and summarizes the latest models and skills required to design and optimize nanomechanical resonators, taking a top-down approach that uses macroscopic formulas to model the devices. The authors cover the electrical and mechanical aspects of nano electromechanical system (NEMS) devices. The introduced mechanical models are also key to the understanding and optimization of nanomechanical resonators used e.g. in optomechanics. Five comprehensive chapters address: The eigenmodes derived for the most common continuum mechanical structures used as nanomechanical resonators; The main sources of energy loss in nanomechanical resonators; The responsiveness of micro and nanomechanical resonators to mass, forces, and temperature; The most common underlying physical transduction mechanisms; The measurement basics, including amplitude and frequency noise. The applied approach found in this book is appropriate for engineering students and researchers working with micro and nanomechanical...

  8. Study on microstructure and soft magnetism of (Fe{sub 65}Co{sub 35}){sub x}(SiO{sub 2}){sub 1-x} nano-granular films with very high ferromagnetic resonance frequency

    Energy Technology Data Exchange (ETDEWEB)

    Yao Dongsheng [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Institute of Advanced Materials Physics, Faculty of Science, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072 (China); Ge Shihui, E-mail: yaodsh08@yahoo.co [Key Laboratory for Magnetism and Magnetic Materials, Lanzhou University, Lanzhou 730000 (China); Zhou Xueyun [Faculty of Science, Jiujiang University, Jiujiang City 332005, Jiangxi Province (China)

    2010-03-01

    A series of (Fe{sub 65}Co{sub 35}){sub x}(SiO{sub 2}){sub (1-x)} nano-granular films with different volume fraction x are fabricated by magnetron co-sputtering technique. The structure, magnetic and high frequency properties are investigated systematically by using X-ray diffraction, transmission electronic microscopy, vibrating sample magnetometer, resistivity and complex permeability measurements. Study results indicate that the films consist of Fe{sub 65}Co{sub 35} magnetic metal particles uniformly embedded in an insulating SiO{sub 2} matrix. (Fe{sub 65}Co{sub 35}){sub x}(SiO{sub 2}){sub (1-x)} films exhibit large magnetic anisotropy field H{sub k} and excellent soft magnetic properties in a wide x range from 0.80 to 0.52 with coercivity H{sub c} smaller than 18 Oe. A minimum H{sub c} value of 7.8 Oe is obtained for the sample with x=0.60 whose electrical resistivity rho reaches 2220 mu OMEGA cm and the magnetic anisotropy field H{sub k} is as high as 185 Oe. Especially, for the result of complex permeability measurement of the samples, very high ferromagnetic resonance (FMR) frequency is obtained. For the typical sample with x=0.60, the FMR frequency reaches 4.9 GHz, implying a very high cut-off frequency for high frequency applications, and the real part mu' of its complex permeability exceeds 60 below 3.8 GHz while the imaginary part mu'' is very small until f>2.0 GHz. These good high frequency properties imply that (Fe{sub 65}Co{sub 35}){sub x}(SiO{sub 2}){sub (1-x)} granular films are promising for applications in high frequency range. The good soft magnetic properties are ascribed to the exchange coupling among magnetic particles, which is discussed in this paper.

  9. Preparation and Study of Dielectric Property of Polyimide Films Hybrided with Nano Silica-alumina Oxide%纳米硅/铝氧化物杂化聚酰亚胺薄膜的制备与电性能研究

    Institute of Scientific and Technical Information of China (English)

    梁凤芝; 陈磊; 陈昊; 范勇

    2011-01-01

    A nano-alumina sol was synthesized by hydrothermal process and a silica sol was prepared by sol-gel method, then they were doped into polyamic acid matrix. A series of inorganic nano-hybrid polyimide films were prepared by adjusting the molar ratio of nano-silicon/ aluminum oxides whose total content is 24%. The structure and properties of the films were characterized by SEM and measured by corona discharge measuring equipment and breakdown strength measuring system respectively. The results show that inorganic nano particles are well dispersed in the polyimide matrix when a little amount of silica sol is doped; the corona-resistant time of hybrid films is much longer than that of pure film and when the molar ratio of nano-silicon/ aluminum oxides is 1:13, the corona-resistant time reaches up to 62.15h; When increasing the doping amount of silica sol, the breakdown strength of the doped films first decreases and then increases, but is lower than that of the undoped film.%采用水热法制备纳米氧化铝溶胶,溶胶-凝胶法制备氧化硅溶胶,并将两者掺杂到聚酰亚胺(PI)基体中.实验中固定无机物掺杂总量为24%,通过调整纳米硅/铝氧化物的摩尔比,制备出一系列的无机纳米杂化聚酰亚胺薄膜.利用扫描电子显微镜(SEM)、耐电晕测试装置、耐击穿测试装置对薄膜进行了表征与测试.结果表明:硅溶胶掺杂量较小时,纳米粒子能较好地分散在聚酰亚胺基体中;杂化薄膜的耐电晕时间比纯膜有较大幅度提高,硅/铝摩尔比为1:13时,耐电晕时间达到62.15 h;随着硅溶胶掺杂量的增加,杂化薄膜的击穿强度先减小后增大,但均比纯膜的低.

  10. Hybridized tetraquarks

    Directory of Open Access Journals (Sweden)

    A. Esposito

    2016-07-01

    Full Text Available We propose a new interpretation of the neutral and charged X,Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules but rather a manifestation of the interplay between the two. While meson molecules need a negative or zero binding energy, its counterpart for h-tetraquarks is required to be positive. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs0π± channel by the D0 Collaboration and the negative result presented subsequently by the LHCb Collaboration are understood in this scheme, together with a considerable portion of available data on X,Z particles. Considerations on a state with the same quantum numbers as the X(5568 are also made.

  11. Hybridized Tetraquarks

    CERN Document Server

    Esposito, A.; Polosa, A.D.

    2016-01-01

    We propose a new interpretation of the neutral and charged X, Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules. The latter would require a negative or zero binding energy whose counterpart in h-tetraquarks is a positive quantity. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs pi+- channel by the D0 collaboration and the negative result presented subsequently by the LHCb collaboration are understood in this scheme, together with a considerable portion of available data on X, Z particles. Considerations on a state with the same quantum numbers as the X(5568) are also made.

  12. 纳米TiO2/有机-无机杂化丙烯酸复合涂层机械及耐腐蚀性能的研究%Study on the mechanical properties and corrosion resistance properties of nano-TiO2/organic-inorganic hybrid acrylic composite coating

    Institute of Scientific and Technical Information of China (English)

    李婕; 孙小英; 杭建忠; 施利毅; 程银银

    2012-01-01

    The organic-inorganic hybridization acrylic resin was synthesized with sol-gel method,and the effects of the addition of nano-TiO2 on mechanical properties and corrosion resistance properties of organic-inorganic hybridization acrylic composite coatings have been investigated in detail.The result showed that,when adding 15wt% nano-TiO2,the hardness of coating was improved from 3 to 6H,the salt spray resistance time increased from 100 to 500h,and the resistance got to 106Ω·cm2.Moreover,it can be observed clearly that nano particles dispersed uniformly and densely in the coatings by SEM.The coordination of organic-inorganic hybridization acrylic resin and nano-TiO2 was a good potential method for improving the mechanical properties and corrosion resistance properties of coatings.%在采用溶胶-凝胶法合成有机-无机杂化丙烯酸树脂的基础上,研究了纳米TiO2添加量对有机-无机杂化丙烯酸复合涂层机械和耐腐蚀等性能的影响。研究表明,当纳米TiO2添加量为15%时,涂层的性能有了较大的提高,其硬度由3H提高至6H,涂层的耐盐雾时间由100h提高到500h,涂层的阻抗值也由104Ω.cm2提高至106Ω.cm2。另外,通过扫描电镜观察了复合涂层的断面,发现涂层中纳米粒子分散均匀,并且粘接紧密,形成了较为致密的复合涂层。

  13. Nano-images as hybrid monsters

    NARCIS (Netherlands)

    Ruivenkamp, Martin; Rip, Arie; Coopmans, Catelijne; Vertesi, Janet; Lynch, Michael E.; Woolgar, Steve

    2014-01-01

    This chapter discusses the role of images in nanotechnology. Nanotechnology includes an array of scientific and engineering fields in which researchers observe and manipulate materials at or near the nanometer scale (one billionth of a meter). The very idea of visualizing nanoscale phenomena is cont

  14. MULTIFUNCTIONAL NANO-BIO MATERIALS WITHIN CELLULAR MACHINERY.

    Science.gov (United States)

    Rozhkova, E A; Ulasov, I V; Kim, D-H; Dimitrijevic, N M; Novosad, V; Bader, S D; Lesniak, M S; Rajh, T

    2011-08-01

    Functional nanoscale materials that possess specific physical or chemical properties can leverage energy transduction in vivo. Once these materials integrate with biomolecules they combine physical properties of inorganic material and the biorecognition capabilities of bio-organic moieties. Such nano-bio hybrids can be interfaced with living cells, the elementary functional units of life. These nano-bio systems are capable of bio-manipulation or actuation via altering intracellular biochemical pathways. Thus, nano-bio conjugates are appealing for a wide range of applications from the life sciences and nanomedicine to catalysis and clean energy production. Here we highlight recent progress in our efforts to develop smart nano-bio hybrid materials, and to study their performance within cellular machinery under application of external stimuli, such as light or magnetic fields.

  15. Electromagnetics of active coated nano-particles

    DEFF Research Database (Denmark)

    Arslanagic, Samel

    2013-01-01

    This work reviews the fundamental properties of several spherical and cylindrical active coated nano-particles excited by their respective single and/or multiple sources of radiation at optical frequencies. Particular attention is devoted to the influence of the source location and orientation......, the optical gain constant and the nano-particle material composition on the electric and magnetic near fields, the power flow density, the radiated power as well as the directivities. Resonant as well as quasi-transparent states will be emphasized in the discussion....

  16. Nano devices and sensors

    CERN Document Server

    Liaw, Shien-Kuei; Chung, Yung-Hui

    2016-01-01

    This volume on semiconductor devices focuses on such topics as nano-imprinting, lithography, nanowire charge-trapping, thermo-stability in nanowires, nano-electrodes, and voltage and materials used for fabricating and improving electrical characteristics of nano-materials.

  17. Tracking microbial interactions with NanoSIMS

    Energy Technology Data Exchange (ETDEWEB)

    Musat, Niculina; Musat, Florin; Weber, Peter Kilian; Pett-Ridge, Jennifer

    2016-10-01

    The combination of stable isotope probing (SIP), NanoSIMS imaging and microbe identification via fluorescence in situ hybridization (FISH) is often used to link identity to function at the cellular level in microbial communities. Many opportunities remain for nanoSIP to identify metabolic interactions and nutrient fluxes within syntrophic associations and obligate symbioses where exchanges can be extremely rapid. However, additional data, such as genomic potential, gene expression or other imaging modalities are often critical to deciphering the mechanisms underlying specific interactions, and researchers must keep sample preparation artefacts in mind. Here we focus on recent applications of nanoSIP, particularly where used to track exchanges of isotopically labelled molecules between organisms. We highlight metabolic interactions within syntrophic consortia, carbon/nitrogen fluxes between phototrophs and their heterotrophic partners, and symbiont–host nutrient sharing.

  18. Phase-controlled Fano resonance by the nanoscale optomechanics

    CERN Document Server

    Zhang, Jian-Qi; Xia, Keyu; Dai, Zhi-Ping; Yang, Wen; Gong, Shangqing; Feng, Mang

    2014-01-01

    Observation of the Fano line shapes is essential to understand properties of the Fano resonance in different physical systems. We explore a tunable Fano resonance by tuning the phase shift in a Mach-Zehnder interferometer (MZI) based on a single-mode nano-optomechanical cavity. The Fano resonance is resulted from the optomechanically induced transparency caused by a nano-mechanical resonator and can be tuned by applying an optomechanical MZI. By tuning the phase shift in one arm of the MZI, we can observe the periodically varying line shapes of the Fano resonance, which represents an elaborate manipulation of the Fano resonance in the nanoscale optomechanics.

  19. Recent Development of Nano-Materials Used in DNA Biosensors

    Directory of Open Access Journals (Sweden)

    Yibin Ying

    2009-07-01

    Full Text Available As knowledge of the structure and function of nucleic acid molecules has increased, sequence-specific DNA detection has gained increased importance. DNA biosensors based on nucleic acid hybridization have been actively developed because of their specificity, speed, portability, and low cost. Recently, there has been considerable interest in using nano-materials for DNA biosensors. Because of their high surface-to-volume ratios and excellent biological compatibilities, nano-materials could be used to increase the amount of DNA immobilization; moreover, DNA bound to nano-materials can maintain its biological activity. Alternatively, signal amplification by labeling a targeted analyte with nano-materials has also been reported for DNA biosensors in many papers. This review summarizes the applications of various nano-materials for DNA biosensors during past five years. We found that nano-materials of small sizes were advantageous as substrates for DNA attachment or as labels for signal amplification; and use of two or more types of nano-materials in the biosensors could improve their overall quality and to overcome the deficiencies of the individual nano-components. Most current DNA biosensors require the use of polymerase chain reaction (PCR in their protocols. However, further development of nano-materials with smaller size and/or with improved biological and chemical properties would substantially enhance the accuracy, selectivity and sensitivity of DNA biosensors. Thus, DNA biosensors without PCR amplification may become a reality in the foreseeable future.

  20. Design of the 1.5 MW, 30-96 MHz ultra-wideband 3 dB high power hybrid coupler for Ion Cyclotron Resonance Frequency (ICRF) heating in fusion grade reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Rana Pratap, E-mail: ranayadav97@gmail.com; Kumar, Sunil; Kulkarni, S. V. [Thapar University, Patiala, Punjab 147004, India and Institute for Plasma Research, Gandhinagar 382428 (India)

    2016-01-15

    Design and developmental procedure of strip-line based 1.5 MW, 30-96 MHz, ultra-wideband high power 3 dB hybrid coupler has been presented and its applicability in ion cyclotron resonance heating (ICRH) in tokamak is discussed. For the high power handling capability, spacing between conductors and ground need to very high. Hence other structural parameters like strip-width, strip thickness coupling gap, and junction also become large which can be gone upto optimum limit where various constrains like fabrication tolerance, discontinuities, and excitation of higher TE and TM modes become prominent and significantly deteriorates the desired parameters of the coupled lines system. In designed hybrid coupler, two 8.34 dB coupled lines are connected in tandem to get desired coupling of 3 dB and air is used as dielectric. The spacing between ground and conductors are taken as 0.164 m for 1.5 MW power handling capability. To have the desired spacing, each of 8.34 dB segments are designed with inner dimension of 3.6 × 1.0 × 40 cm where constraints have been significantly realized, compensated, and applied in designing of 1.5 MW hybrid coupler and presented in paper.