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Sample records for hybrid layers based

  1. Semiconducting properties of layered cadmium sulphide-based hybrid nanocomposites

    Directory of Open Access Journals (Sweden)

    Sotomayor Torres Clivia

    2011-01-01

    Full Text Available Abstract A series of hybrid cadmium salt/cationic surfactant layered nanocomposites containing different concentrations of cadmium sulphide was prepared by exchanging chloride by sulphide ions in the layered precursor CdX x (OH y (CnTA z in a solid phase/gas reaction, resulting in a series of layered species exhibiting stoichiometries corresponding to CdS v X x (OH y (CnTA z , constituted by two-dimensional CdCl2/CdS ultra-thin sheets sandwiched between two self-assembled surfactant layers. The electronic structure of CdS in the nanocomposite is similar to that of bulk, but showing the expected features of two-dimensional confinement of the semiconductor. The nanocomposite band gap is found to depend in a non-linear manner on both the length of the hydrocarbon chain of the surfactant and the concentration of the sulphide in the inorganic sheet. The products show photocatalytic activity at least similar and usually better than that of "bulk" CdS in a factor of two.

  2. Hybrid white light sources based on layer-by-layer assembly of nanocrystals on near-UV emitting diodes

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    Nizamoglu, Sedat; Demir, Hilmi Volkan

    2007-10-01

    We present the design, growth, fabrication, integration and characterization of alternative hybrid white light sources based on the controlled layer-by-layer assembly of nanocrystals on UV-emitting nitride diodes for adjustable white light parameters. We hybridize CdSe/ZnS core-shell nanocrystals of different sizes (1.9-3.2-5.2 nm) on InGaN/GaN LEDs as a near-UV excitation source at 383 nm for efficient pumping. The first device includes layer-by-layer assembly of dichromatic cyan- and red-emitting nanocrystals (λPL = 504-615 nm) leading to the tristimulus coordinates (x = 0.37,y = 0.46); the second device uses the trichromatic combination of layer-by-layer hybridized cyan-, yellow- and red-emitting nanocrystals (λPL = 504-580-615 nm), yielding (x = 0.38,y = 0.48). Such layer-by-layer hybridization offers the advantages of precisely controlling individual nanocrystal film thicknesses and order in addition to concentrations. By utilizing such multiple combinations of nanocrystals in the assembly, the light parameters are well controlled and adjusted. Leveraging rapidly advancing UV technology into efficient lighting with nanocrystal based color conversion, it is critical to develop and demonstrate hybrid light sources on UV pumping platforms.

  3. Design of Transport Layer Based Hybrid Covert Channel Detection Engine

    CERN Document Server

    K, Anjan; Jadhav, Mamatha; 10.5121/ijasuc.2010.1409

    2011-01-01

    Computer network is unpredictable due to information warfare and is prone to various attacks. Such attacks on network compromise the most important attribute, the privacy. Most of such attacks are devised using special communication channel called "Covert Channel". The word "Covert" stands for hidden or non-transparent. Network Covert Channel is a concealed communication path within legitimate network communication that clearly violates security policies laid down. The non-transparency in covert channel is also referred to as trapdoor. A trapdoor is unintended design within legitimate communication whose motto is to leak information. Subliminal channel, a variant of covert channel works similarly except that the trapdoor is set in a cryptographic algorithm. A composition of covert channel with subliminal channel is the "Hybrid Covert Channel". Hybrid covert channel is homogenous or heterogeneous mixture of two or more variants of covert channels either active at same instance or at different instances of time...

  4. Interfacial micromorphological differences in hybrid layer formation between water- and solvent-based dentin bonding systems.

    Science.gov (United States)

    Gregoire, Geneviève L; Akon, Bernadette A; Millas, Arlette

    2002-06-01

    Many dentin bonding systems of different compositions, and in particular containing different solvents, have been introduced to the market. Their effect on the quality of the interface requires clarification by means of comparative trials. This study investigated micromorphological differences in hybrid layer formation with a variety of commercially available water- or solvent-based dentin bonding products and their recommended compomers. Five bonding systems were used on groups of 10 teeth each as follows: group I, acetone-based system used with 36% phosphoric acid; group II, a different acetone-based system containing nano-sized particles for filler loading and used with a non-rinsing conditioner containing maleic acid; group III, the acetone-based system of group II used with 36% phosphoric acid (the only difference in the treatment for groups II and III was the acid etching system); group IV, a mixed-solvent-based system (water/ethanol) used with 37% phosphoric acid; and group V, a water-based system used with 37% phosphoric acid. Each bonding system was covered with the recommended compomer. Class I occlusal preparations were made in extracted teeth and restored with one of the above systems. Five specimens of each group were studied with optical microscopy after staining. Scanning electron microscopy was used to examine the interface of the bonding system/dentin of the other 5 teeth in each group. The optical microscopy measurements were made with a 10 x 10 reticle. A micron mark with scale was used for the scanning electron microscope. All measurements were made in microm. The following criteria were used to define a good interface: absence of voids between the different parts of the interface, uniformity of the hybrid layer, good opening of the tubuli orifices, and tag adherence to the tubuli walls. Morphological differences were found at the interface depending on dentin treatment and adhesive composition. The acetone-containing systems were associated

  5. Photodetectors Based on Two-Dimensional Layer-Structured Hybrid Lead Iodide Perovskite Semiconductors.

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    Zhou, Jiachen; Chu, Yingli; Huang, Jia

    2016-10-05

    Hybrid lead iodide perovskite semiconductors have attracted intense research interests recently because of their easy fabrication processes and high power conversion efficiencies in photovoltaic applications. Layer-structured materials have interesting properties such as quantum confinement effect and tunable band gap due to the unique two-dimensional crystalline structures. ⟨100⟩-oriented layer-structured perovskite materials are inherited from three-dimensional ABX3 perovskite materials with a generalized formula of (RNH3)2(CH3NH3)n-1MnX3n+1, and adopt the Ruddlesden-Popper type crystalline structure. Here we report the synthesis and investigation of three layer-structured perovskite materials with different layer numbers: (C4H9NH3)2PbI4 (n = 1, one-layered perovskite), (C4H9NH3)2(CH3NH3)Pb2I7 (n = 2, two-layered perovskite) and (C4H9NH3)2(CH3NH3)2Pb3I10 (n = 3, three-layered perovskite). Their photoelectronic properties were investigated in related to their molecular structures. Photodetectors based on these two-dimensional (2D) layer-structured perovskite materials showed tunable photoresponse with short response time in milliseconds. The photodetectors based on three-layered perovskite showed better performances than those of the other two devices, in terms of output current, responsivity, Ilight/Idark ratio, and response time, because of its smaller optical band gap and more condensed microstructure comparing the other two materials. These results revealed the relationship between the molecular structures, film microstructures and the photoresponse properties of 2D layer-structured hybrid perovskites, and demonstrated their potentials as flexible, functional, and tunable semiconductors in optoelectronic applications, by taking advantage of their tunable quantum well molecular structure.

  6. Near-zero-residual layer nanoimprint based on hybrid nanoimprint soft lithography

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    Cui, Yushuang; Lu, Jingjun; Fu, XinXin; Bian, Jie; Yuan, Changsheng; Ge, Haixiong; Chen, Yanfeng

    2015-11-01

    A thin and uniform residual layer, especially zero-residual layer, is highly desired in the nanoimprint lithography, because it is critical to the succeeding pattern transfer process. In this study, a partial cavity filling method was applied on UV-curable resins instead of thermal plastic polymer to realize zero-residual layer based on a hybrid nanoimprint technique. The initial thickness of the UV-curable resin on the substrate was precisely quantified less than the cavity volume of the imprint mold by adjusting the resin concentration and spin coating speed. A near-zero-residual layer was successfully achieved under an extremely low imprint pressure by the control of the viscosity, surface tension and thickness of the UV-curable resist.

  7. Gold Nanoparticle-based Layer-by-Layer Enhancement of DNA Hybridization Electrochemical Signal at Carbon Nanotube Modified Carbon Paste Electrode

    Institute of Scientific and Technical Information of China (English)

    Li Bo NIE; Jian Rong CHEN; Yu Qing MIAO; Nong Yue HE

    2006-01-01

    Colloid gold nanoparticle-based layer-by-layer amplification approach was applied to enhance the electrochemical detection sensitivity of DNA hybridization at carbon nanotube modified carbon paste electrodes (CNTPEs). Streptavidin was immobilized onto the surface of CNTPEs, and the conjugation of biotin labeled target oligonucleotides to the above immobilized streptavidin was performed, followed by the hybridization of target oligonucleotides with the gold nanoparticle-labeled DNA probe and then the layer-by-layer enhanced connection of gold nanoparticles, on which oligonucleotides complementary to the DNA probe were attached, to the hybridization system. The differential pulse voltammetry (DPV) signal of total gold nanoparticles was monitored. It was found that the layer-by-layer colloidal gold DPV detection enhanced the sensitivity by about one order of magnitude compared with that of one-layer detection. One-base mismatched DNA and complementary DNA could be distinguished clearly.

  8. Hybrid Materials Based on Magnetic Layered Double Hydroxides: A Molecular Perspective.

    Science.gov (United States)

    Abellán, Gonzalo; Martí-Gastaldo, Carlos; Ribera, Antonio; Coronado, Eugenio

    2015-06-16

    Design of functional hybrids lies at the very core of synthetic chemistry as it has enabled the development of an unlimited number of solids displaying unprecedented or even improved properties built upon the association at the molecular level of quite disparate components by chemical design. Multifunctional hybrids are a particularly appealing case among hybrid organic/inorganic materials. Here, chemical knowledge is used to deploy molecular components bearing different functionalities within a single solid so that these properties can coexist or event interact leading to unprecedented phenomena. From a molecular perspective, this can be done either by controlled assembly of organic/inorganic molecular tectons into an extended architecture of hybrid nature or by intercalation of organic moieties within the empty channels or interlamellar space offered by inorganic solids with three-dimensional (MOFs, zeolites, and mesoporous hosts) or layered structures (phosphates, silicates, metal dichalcogenides, or anionic clays). This Account specifically illustrates the use of layered double hydroxides (LDHs) in the preparation of magnetic hybrids, in line with the development of soft inorganic chemistry processes (also called "Chimie Douce"), which has significantly contributed to boost the preparation hybrid materials based on solid-state hosts and subsequent development of applications. Several features sustain the importance of LDHs in this context. Their magnetism can be manipulated at a molecular level by adequate choice of constituting metals and interlayer separation for tuning the nature and extent of magnetic interactions across and between planes. They display unparalleled versatility in accommodating a broad range of anionic species in their interlamellar space that encompasses not only simple anions but chemical systems of increasing dimensionality and functionalities. Their swelling characteristics allow for their exfoliation in organic solvents with high

  9. Facile Fabrication of 3D Layer-by-layer Graphene-gold Nanorod Hybrid Architecture for Hydrogen Peroxide Based Electrochemical Biosensor

    Science.gov (United States)

    2015-01-01

    Facile fabrication of 3D layer-by-layer graphene-gold nanorod hybrid architecture for hydrogen peroxide based electrochemical biosensor Chenming Xue...the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). 1. Introduction Electrochemical biosensors are highly effective in...measurement techniques such as radioisotope tracing, NMR spectroscopy, and microfluorometry assay [12,25,18]. In recent years, electrochemical biosensors

  10. Hybrid pn-junction solar cells based on layers of inorganic nanocrystals and organic semiconductors: optimization of layer thickness by considering the width of the depletion region.

    Science.gov (United States)

    Saha, Sudip K; Guchhait, Asim; Pal, Amlan J

    2014-03-07

    We report the formation and characterization of hybrid pn-junction solar cells based on a layer of copper diffused silver indium disulfide (AgInS2@Cu) nanoparticles and another layer of copper phthalocyanine (CuPc) molecules. With copper diffusion in the nanocrystals, their optical absorption and hence the activity of the hybrid pn-junction solar cells was extended towards the near-IR region. To decrease the particle-to-particle separation for improved carrier transport through the inorganic layer, we replaced the long-chain ligands of copper-diffused nanocrystals in each monolayer with short-ones. Under illumination, the hybrid pn-junctions yielded a higher short-circuit current as compared to the combined contribution of the Schottky junctions based on the components. A wider depletion region at the interface between the two active layers in the pn-junction device as compared to that of the Schottky junctions has been considered to analyze the results. Capacitance-voltage characteristics under a dark condition supported such a hypothesis. We also determined the width of the depletion region in the two layers separately so that a pn-junction could be formed with a tailored thickness of the two materials. Such a "fully-depleted" device resulted in an improved photovoltaic performance, primarily due to lessening of the internal resistance of the hybrid pn-junction solar cells.

  11. The effect of fibre layering pattern in resisting bending loads of natural fibre-based hybrid composite materials

    Directory of Open Access Journals (Sweden)

    Jusoh Muhamad Shahirul Mat

    2016-01-01

    Full Text Available The effect of fibre layering pattern and hybridization on the flexural properties of composite hybrid laminates between natural fibres of basalt, jute and flax with synthetic fibre of E-glass reinforced epoxy have been investigated experimentally. Results showed that the effect fibre layering pattern was highly significant on the flexural strength and modulus, which were strongly dependent on the hybrid configuration between sandwich-like (SL and intercalation (IC sequence of fibre layers. In addition, specific modulus based on the variation densities of the hybrid laminates was used to discover the best combination either basalt, jute or flax with E-glass exhibits superior properties concerning on the strength to weight-ratio. Generally, SL sequence of glass/basalt exhibited superior strength and stiffness compared with glass/jute and glass/flax in resisting bending loads. In terms of hybridization effect, glass/jute was found to be the best combination with E-glass compared to the rest of natural fibres investigated in the present study. Hence, the proper stacking sequences and material selection are among predominant factors that influence on mechanical properties and very crucial in designing composite hybrid system to meet the desired requirements.

  12. Nanoleakage in Hybrid Layer and Acid-Base Resistant Zone at the Adhesive/Dentin Interface.

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    Nikaido, Toru; Nurrohman, Hamid; Takagaki, Tomohiro; Sadr, Alireza; Ichinose, Shizuko; Tagami, Junji

    2015-10-01

    The aim of interfacial nanoleakage evaluation is to gain a better understanding of degradation of the adhesive-dentin interface. The acid-base resistant zone (ABRZ) is recognized at the bonded interface under the hybrid layer (HL) in self-etch adhesive systems after an acid-base challenge. The purpose of this study was to evaluate nanoleakage in HL and ABRZ using three self-etch adhesives; Clearfil SE Bond (SEB), Clearfil SE One (SEO), and G-Bond Plus (GBP). One of the three adhesives was applied on the ground dentin surface and light cured. The specimens were longitudinally divided into two halves. One half remained as the control group. The others were immersed in ammoniacal silver nitrate solution, followed by photo developing solution under fluorescent light. Following this, the specimens were subjected to acid-base challenges with an artificial demineralization solution (pH4.5) and sodium hypochlorite, and prepared in accordance with common procedures for transmission electron microscopy (TEM) examination. The TEM images revealed silver depositions in HL and ABRZ due to nanoleakage in all the adhesives; however, the extent of nanoleakage was material dependent. Funnel-shaped erosion beneath the ABRZ was observed only in the all-in-one adhesive systems; SEO and GBP, but not in the two-step self-etch adhesive system; SEB.

  13. Intercalation assembly of optical hybrid materials based on layered terbium hydroxide hosts and organic sensitizer anions guests

    Institute of Scientific and Technical Information of China (English)

    Liang-Liang Liu; Qin Wang; Dan Xia; Ting-Ting Shen; Ming-Hui Yu; Wei-Sheng Liu; Yu Tang

    2013-01-01

    Optical hybrid materials based on inorganic hosts and organic sensitizer guests hold promise for a virtually unlimited number of applications.In particular,the interaction and the combination of the properties of a defined inorganic matrix and a specific sensitizer could lead to synergistic effects in luminescence enhancing and tuning.The current article focuses on the intercalation assembly of optical hybrid materials based on the layered terbium hydroxide (LTbH) hosts and organic divalent carboxylic sensitizer anion guests by a hydrothermal process.The studies on the interactions between hosts and guests indicate that the type and arrangement of organic guests in the layer spacing of the LTbH hosts can make a difference in the luminescence of the hybrid inorganic-organic materials.

  14. Hybrid magnetic materials based on layered double hydroxides: from the chemistry towards the applications

    OpenAIRE

    ABELLÁN SÁEZ, GONZALO

    2014-01-01

    Layered double hydroxides (LDHs) are the leitmotiv of this dissertation. Contradicting the assertion that “any past was better”, LDHs have been continuously revisited from the middle of the twentieth century, and represent an excellent example of the never-ending beauty of Chemistry. New synthetic perspectives are giving a new impetus to LDH chemistry, which among hybrid materials, are finding their heyday. This is resulting in novel materials and also paving the way for new fundamental and p...

  15. Model-based Layer Estimation using a Hybrid Genetic/Gradient Search Optimization Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D; Lehman, S; Dowla, F

    2007-05-17

    A particle swarm optimization (PSO) algorithm is combined with a gradient search method in a model-based approach for extracting interface positions in a one-dimensional multilayer structure from acoustic or radar reflections. The basic approach is to predict the reflection measurement using a simulation of one-dimensional wave propagation in a multi-layer, evaluate the error between prediction and measurement, and then update the simulation parameters to minimize the error. Gradient search methods alone fail due to the number of local minima in the error surface close to the desired global minimum. The PSO approach avoids this problem by randomly sampling the region of the error surface around the global minimum, but at the cost of a large number of evaluations of the simulator. The hybrid approach uses the PSO at the beginning to locate the general area around the global minimum then switches to the gradient search method to zero in on it. Examples of the algorithm applied to the detection of interior walls of a building from reflected ultra-wideband radar signals are shown. Other possible applications are optical inspection of coatings and ultrasonic measurement of multilayer structures.

  16. Layer-by-Layer assembled hybrid multilayer thin film electrodes based on transparent cellulose nanofibers paper for flexible supercapacitors applications

    Science.gov (United States)

    Wang, Xi; Gao, Kezheng; Shao, Ziqiang; Peng, Xiaoqing; Wu, Xue; Wang, Feijun

    2014-03-01

    Cellulose nanofibers (CNFs) paper with low thermal expansion and electrolyte absorption properties is considered to be a good potential substrate for supercapacitors. Unlike traditional substrates, such as glass or plastic, CNFs paper saves surfaces pretreatment when Layer-by-Layer (LbL) assembly method is used. In this study, negatively charged graphene oxide (GO) nanosheets and poly(3,4-ethylenedioxythiophene: poly(styrene sulfonate)) (PEDOT:PSS) nanoparticles are deposited onto CNFs paper with positively charged polyaniline (PANI) nanowires as agents to prepare multilayer thin film electrodes, respectively. Due to the different nanostructures of reduced graphene oxide (RGO) and PEDOT:PSS, the microstructures of the electrodes are distinguishing. Our work demonstrate that CNFs paper/PANI/RGO electrode provides a more effective pathway for ion transport facilitation compared with CNFs paper/PANI/PEDOT:PSS electrode. The supercapacitor fabricated by CNFs/[PANI-RGO]8 (S-PG-8) exhibits an excellent areal capacitance of 5.86 mF cm-2 at a current density of 0.0043 mA cm-2, and at the same current density the areal capacitance of the supercapacitor fabricated by CNFs/[PANI-PEDOT:PSS]8 (S-PP-8) is 4.22 mF cm-2. S-PG-8 also exhibits good cyclic stability. This study provides a novel method using CNFs as substrate to prepare hybrid electrodes with diverse microstructures that are promising for future flexible supercapacitors.

  17. Excellent anti-corrosive pretreatment layer on iron substrate based on three-dimensional porous phytic acid/silane hybrid

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    Gao, Xiang; Lu, Ke; Xu, Lei; Xu, Hua; Lu, Haifeng; Gao, Feng; Hou, Shifeng; Ma, Houyi

    2016-01-01

    A novel, highly effective and environmentally friendly film-forming material, phytic acid (PA)/silane (denoted as PAS) hybrid with a three-dimensional (3D) network structure, was prepared through a condensation reaction of PA with methyltrihydroxysilane generated from the hydrolysis of methyltriethoxysilane (MTES). Two kinds of PAS-based pretreatment layers, namely NaBrO3-free and NaBrO3-doped PAS layers, were fabricated on iron substrates using the dip-coating method. SEM and AFM observations showed that the as-fabricated PAS-based layers possessed a 3D porous microstructure at the nanoscale and a rough surface morphology. X-ray photoelectron spectroscopic (XPS) and attenuated total reflection infrared (ATR-IR) spectroscopic characterization demonstrated that the above PAS layers bound to the iron surface via the -P-O- bond. Moreover, analyses of steady-state polarization curves and electrochemical impedance spectroscopic (EIS) data indicated that the corrosion rates of the iron substrates decreased considerably in the presence of the two PAS-based pretreatment layers. In particular, the NaBrO3-dosed PAS layer displayed the better corrosion resistance ability as well as maintaining the original microstructure and surface morphology. The PAS-based pretreatment layers are expected to act as substitutes for chromate and phosphate conversion layers and will find widespread application in the surface pretreatment of iron and steel materials due to the advantages of being environmentally friendly, the rapid film-forming process, and, especially, the nanoporous microstructure and rough surface morphology.A novel, highly effective and environmentally friendly film-forming material, phytic acid (PA)/silane (denoted as PAS) hybrid with a three-dimensional (3D) network structure, was prepared through a condensation reaction of PA with methyltrihydroxysilane generated from the hydrolysis of methyltriethoxysilane (MTES). Two kinds of PAS-based pretreatment layers, namely Na

  18. Organic–inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides with intercalated phacolysin as ocular delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhiguo; Zhang, Jie; Chi, Huibo; Cao, Feng, E-mail: cpufengc@163.com [China Pharmaceutical University, Department of Pharmaceutics, School of Pharmacy (China)

    2015-12-15

    This study was mainly aimed to evaluate the potential use of a novel ocular drug delivery system, organic–inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides (LDH). Organic polymers of chitosan–glutathione (CG) and pre-activated chitosan–glutathione (CG-2MNA) were successfully synthesized and characterized. LDH with intercalated phacolysin (PCL), including larger hexagonal LDH–PCL (Lh-LDH–PCL), larger spherical LDH–PCL (Ls-LDH–PCL), smaller hexagonal LDH–PCL (Sh-LDH–PCL), CG hybrid LDH–PCL (LDH–PCL-CG), and CG-2MNA hybrid LDH–PCL (LDH–PCL-CG-2MNA), were prepared. The nanocomposites with particle size of 107.2–274.9 nm were characterized by powder X-ray diffraction, Fourier transform infrared, transmission electron micrographs, etc. In vivo precorneal retention studies showed that the detectable time of all nanocomposites was prolonged from 2 to 6 h in comparison to PCL saline. Accordingly, the AUC{sub 0–6h} values of Lh-LDH–PCL, Ls-LDH–PCL, Sh-LDH–PCL, LDH–PCL-CG, and LDH–PCL-CG-2MNA nanocomposites were increased by 2.27-, 2.08-, 3.08-, 4.67-, and 3.36-fold, respectively. The Draize test and hematoxylin and eosin staining demonstrated that modified LDH had no eye irritation after single and repeated administration. These results indicated that chitosan derivatives-LDH hybrid nanocomposite dispersion could be a promising ocular drug delivery system to improve precorneal retention time of drugs.Graphical AbstractThiolated chitosan-LDH hybrid nanocomposite dispersion could be a promising ocular drug delivery system to improve precorneal retention time of drugs and may facilitate penetration of drugs into tissues of the eyes.

  19. Electroactive functional hybrid layered nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Destri, Giovanni Li; Torrisi, Vanna; Marletta, Giovanni [Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN) - University of Catania and CSGI - Catania (Italy)

    2012-07-11

    Two methodologies to build new nanostructured hybrid layered nanocomposites are presented. The first one involves the preparation of hybrid metal/polymer nanolayers (NLs) by combining two monolayer preparation techniques: Horizontal Precipitation Langmuir Blodgett method (HP-ML), for copolymer monolayers and sputter deposition technique, for Au NLs deposition. The second methodology is aimed to prepare regular arrays of nanopores, with diameter ranging between 40-100 nm, in ultra-thin films of electroactive polymers, to obtain embedded regular arrays of nanopores filled by a further electroactive organic component. The produced hybrid MLs have been characterized by means of X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM) and Grazing Incidence X-ray Diffraction (GI-XRD). In the first case, current-voltage (I-V) measurements demonstrate that the multilayers exhibit a bipolar conduction behaviour (electrons and holes carriers), with a peculiar transition in the nature of the majority carriers (from holes to electrons) above a threshold number of bilayers. In the second case, it is found that the degree of pore filling, as well as the polymer crystallinity can be easily modulated, prompting the tuning of the photoresponse of the nanocomposites.

  20. Bifunctional sensor of pentachlorophenol and copper ions based on nanostructured hybrid films of humic acid and exfoliated layered double hydroxide via a facile layer-by-layer assembly.

    Science.gov (United States)

    Yuan, Shuang; Peng, Dinghua; Hu, Xianluo; Gong, Jingming

    2013-06-27

    A new, highly sensitive bifunctional electrochemical sensor for the simultaneous determination of pentachlorophenol (PCP) and copper ions (Cu(2+)) has been developed, where organic-inorganic hybrid ultrathin films were fabricated by alternate assembly of humic acid (HA) and exfoliated Mg-Al-layered double hydroxide (LDH) nanosheets onto ITO substrates via a layer-by-layer (LBL) approach. The multilayer films were then characterized by means of UV-vis spectrometry, scanning electron microscopy (SEM), and atomic force microscope (AFM). These films were found to have a relatively smooth surface with almost equal amounts of HA incorporated in each cycle. Its electrochemical performance was systematically investigated. Our results demonstrate that such a newly designed (LDH/HA)n multilayer films, combining the individual properties of HA (dual recognition ability for organic herbicides and metal ions) together with LDH nanosheets (a rigid inorganic matrix), can be applied to the simultaneous analysis of PCP and Cu(II) without interference from each other. The LBL assembled nanoarchitectures were further investigated by X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR), which provides insight for bifunctional sensing behavior. Under the optimized conditions, the detection limit was found to be as low as 0.4 nM PCP, well below the guideline value of PCP in drinking water (3.7 nM) set by the United States Environmental Protection Agency (U.S. EPA), and 2.0 nM Cu(2+), much below the guideline value (2.0 mg L(-1), ~31.2 nM) from the World Health Organization (WHO), respectively. Toward the goal for practical applications, this simple and cost-effective probe was further evaluated by monitoring PCP and Cu(II) in water samples.

  1. Facile fabrication of 3D layer-by-layer graphene-gold nanorod hybrid architecture for hydrogen peroxide based electrochemical biosensor

    Directory of Open Access Journals (Sweden)

    Chenming Xue

    2015-03-01

    Full Text Available Three-dimensional (3D layer-by-layer graphene-gold nanorod (GNR architecture has been constructed. The resulting hybrid nanomaterials’ architecture has been tested for detecting hydrogen peroxide (H2O2 through the electrocatalytic reaction on a three electrode disposable biosensor platform. Cyclic voltammetry and amperometry were used to characterize and assess the performance of the biosensor. The 3D layer-by-layer modified electrode exhibited the highest sensitivity compared to the active carbon, graphene-oxide, cysteine-graphene oxide and GNR coated electrodes. This research explored the feasibility of using the 3D hybrid graphene-GNR as a template for biosensor. The 3D hybrid structure exhibited higher sensitivity than GNRs alone. SEM showed the explanation that GNRs had self-aggregates reducing the contact surface area when coated on the active carbon electrode, while there were no such aggregates in the 3D structure, and TEM illustrated that GNRs dispersed well in the 3D structure. This research demonstrated a better way to prepare well-separated metal nanoparticles by using the 3D layer-by-layer structure. Consequently, other single and bi-metallic metal nanoparticles could be incorporated into such structure. As a practical example, 3D layer-by-layer nanomaterials modified active carbon electrode was used for detecting glucose showing very good sensitivity and minimum interference by ascorbic acid and uric acid in test solution, which indicated a good selectivity of the biosensor as well.

  2. Comparison of perfectly matched layer and multi-transmitting formula artificial boundary condition based on hybrid finite element formulation

    Institute of Scientific and Technical Information of China (English)

    LI Ning; XIE Li-li; ZHAI Chang-hai

    2007-01-01

    The theory of perfectly matched layer (PML) artificial boundary condition (ABC), which is characterized by absorption any wave motions with arbitrary frequency and arbitrarily incident angle, is introduced. The construction process of PML boundary based on elastodynamic partial differential equation (PDE) system is developed.Combining with velocity-stress hybrid finite element formulation, the applicability of PML boundary is investigated and the numerical reflection of PML boundary is estimated. The reflectivity of PML and multi-transmitting formula (MTF) boundary is then compared based on body wave and surface wave simulations. The results show that although PML boundary yields some reflection, its absorption performance is superior to MTF boundary in the numerical simulations of near-fault wave propagation, especially in corner and large angle grazing incidence situations. The PML boundary does not arise any unstable phenomenon and the stability of PML boundary is better than MTF boundary in hybrid finite element method. For a specified problem and analysis tolerance, the computational efficiency of PML boundary is only a little lower than MTF boundary.

  3. Influence of voids in the hybrid layer based on self-etching adhesive systems: a 3-D FE analysis

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    Ana Paula Martini

    2009-01-01

    Full Text Available The presence of porosities at the dentin/adhesive interface has been observed with the use of new generation dentin bonding systems. These porosities tend to contradict the concept that etching and hybridization processes occur equally and simultaneously. Therefore, the aim of this study was to evaluate the micromechanical behavior of the hybrid layer (HL with voids based on a self-etching adhesive system using 3-D finite element (FE analysis. MATERIAL AND METHODS: Three FE models (Mr were built: Mr, dentin specimen (41x41x82 μm with a regular and perfect (i.e. pore-free HL based on a self-etching adhesive system, restored with composite resin; Mp, similar to M, but containing 25% (v/v voids in the HL; Mpp, similar to Mr, but containing 50% (v/v voids in the HL. A tensile load (0.03N was applied on top of the composite resin. The stress field was obtained by using Ansys Workbench 10.0. The nodes of the base of the specimen were constrained in the x, y and z axes. The maximum principal stress (σmax was obtained for all structures at the dentin/adhesive interface. RESULTS: The Mpp showed the highest peak of σmax in the HL (32.2 MPa, followed by Mp (30 MPa and Mr (28.4 MPa. The stress concentration in the peritubular dentin was high in all models (120 MPa. All other structures positioned far from voids showed similar increase of stress. CONCLUSION: Voids incorporated into the HL raised the σmax in this region by 13.5%. This behavior might be responsible for lower bond strengths of self-etching and single-bottle adhesives, as reported in the literature.

  4. Hybrid fluorescent layer emitting polarized light

    Science.gov (United States)

    Mohammadimasoudi, Mohammad; Beeckman, Jeroen; Hens, Zeger; Neyts, Kristiaan

    2017-07-01

    Semiconductor nanorods have anisotropic absorption and emission properties. In this work a hybrid luminescent layer is produced based on a mixture of CdSe/CdS nanorods dispersed in a liquid crystal that is aligned by an electric field and polymerized by UV illumination. The film emits light with polarization ratio 0.6 (polarization contrast 4:1). Clusters of nanorods in liquid crystal can be avoided by applying an AC electric field with sufficient amplitude. This method can be made compatible with large-scale processing on flexible transparent substrates. Thin polarized light emitters can be used in LCD backlights or solar concentrators to increase the efficiency.

  5. Hybrid fluorescent layer emitting polarized light

    Directory of Open Access Journals (Sweden)

    Mohammad Mohammadimasoudi

    2017-07-01

    Full Text Available Semiconductor nanorods have anisotropic absorption and emission properties. In this work a hybrid luminescent layer is produced based on a mixture of CdSe/CdS nanorods dispersed in a liquid crystal that is aligned by an electric field and polymerized by UV illumination. The film emits light with polarization ratio 0.6 (polarization contrast 4:1. Clusters of nanorods in liquid crystal can be avoided by applying an AC electric field with sufficient amplitude. This method can be made compatible with large-scale processing on flexible transparent substrates. Thin polarized light emitters can be used in LCD backlights or solar concentrators to increase the efficiency.

  6. Resin infusion of layered metal/composite hybrid and resulting metal/composite hybrid laminate

    Science.gov (United States)

    Cano, Roberto J. (Inventor); Grimsley, Brian W. (Inventor); Weiser, Erik S. (Inventor); Jensen, Brian J. (Inventor)

    2009-01-01

    A method of fabricating a metal/composite hybrid laminate is provided. One or more layered arrangements are stacked on a solid base to form a layered structure. Each layered arrangement is defined by a fibrous material and a perforated metal sheet. A resin in its liquid state is introduced along a portion of the layered structure while a differential pressure is applied across the laminate structure until the resin permeates the fibrous material of each layered arrangement and fills perforations in each perforated metal sheet. The resin is cured thereby yielding a metal/composite hybrid laminate.

  7. Hybrid magnetic amphiphilic composites based on carbon nanotube/nanofibers and layered silicates fragments as efficient adsorbent for ethynilestradiol.

    Science.gov (United States)

    Purceno, Aluir D; Teixeira, Ana Paula C; de Souza, Nubia Janaína; Fernandez-Outon, Luis E; Ardisson, José D; Lago, Rochel M

    2012-08-01

    In this work, hybrid magnetic amphiphilic composites were prepared by the catalytic growth of carbon nanotubes (CNTs) and nanofibers CNF on layered silicates fragments. SEM, TEM, Raman, XRD, Mössbauer, TG/DTA showed that CVD with CH(4) at 800°C produced CNF and magnetic Fe cores fixed on the surface of microfragments of silicates layers. Due to the amphiphilic character, the composites can be easily dispersed in water and efficiently adsorb hydrophobic contaminant molecules. For example, the composites showed remarkable adsorption capacities for the hormone ethinylestradiol, e.g. 2-4 mg m(-2), compared to ca. 0.1 mg m(-2) obtained for high surface area activated carbon and multiwall CNT. These results are discussed in terms of a high hydrophobic exposed surface area of the CNT and CNF fixed on the layered silicates fragments surface. Moreover, the composites can be easily removed from water by a simple magnetic separation process.

  8. Cross-Layer Approach using k-NN Based Adaptive Modulation Coding (AMC and Incremental Redundancy Hybrid Automatic Repeat Request (IR-HARQ for MIMO

    Directory of Open Access Journals (Sweden)

    J. Sofia Priya Dharshini

    2014-09-01

    Full Text Available In MIMO Technology, a cross layer design enhances the spectral efficiency, reliability and throughput of the network. In this paper, a cross-layer approach using k-NN based Adaptive Modulation Coding (AMC and Incremental Redundancy Hybrid Automatic Repeat Request (IR-HARQ is proposed for MIMO Systems. The proposed cross layer approach connects physical layer and data link layer to enhance the performance of MIMO network. By means of MIMO fading channels, the coded symbols are forwarded in the physical layer on a frame by frame fashion subsequently using Space Time Block Coding (STBC. The receiver computes the signal to noise ratio (SNR and forwards back to the AMC controller. The controller selects a suitable MCS for the next transmission through k-NN classifier supervised learning algorithm. IR-HARQ is utilized at the data link layer to regulate packet retransmissions. The obtained results prove that the proposed technique has better performance in terms of throughput, BER and spectral efficiency

  9. Syntheses, structures and properties of two 2-D layered hybrid organic-inorganic materials based on different V4O12 building units.

    Science.gov (United States)

    Hou, Wentao; Guo, Jiuyu; Xu, Xiao; Wang, Zuoxiang; Zhang, Deng; Wan, Hongxiang; Song, You; Zhu, Dunru; Xu, Yan

    2014-01-14

    Two new layered hybrid organic-inorganic compounds [Zn(pyim)]2V4O12 () (pyim = 2-(2-pyridyl)imidazole) and [Cu(bim)2]2V4O12(H2O)·CH3CH2OH () (bim = bis(1-imidazolyl)methane) based on polyoxovanadates (POVs) and organic ligands decorated transition metal units have been synthesized by hydrothermal and solvothermal methods respectively. Single crystal XRD, fluorescence spectrum, magnetic measurement, IR spectra, powder XRD and thermogravimetric (TG) measurements were performed to analyze the structures and properties of and . The structural analysis reveals that compound features a two-dimensional {[Zn(pyim)]2V4O12}n layered structure, constructed by sine wave-like {V4O12}n(4n-) chains, Zn(2+) ions and pyim ligands. In the layered structure of , {V4O12}(4-) circles are connected by Cu(2+) ions to form {Cu(V4O12)}n(2n-) chains, which are further linked by {Cu(bim)4}(2+) subunits to generate a hybrid layer of . The magnetic susceptibility measurement indicates strong antiferromagnetic interactions between Cu(2+) ions in .

  10. Bright Visible-Infrared Light Emitting Diodes Based on Hybrid Halide Perovskite with Spiro-OMeTAD as a Hole-Injecting Layer.

    Science.gov (United States)

    Jaramillo-Quintero, Oscar A; Sanchez, Rafael S; Rincon, Marina; Mora-Sero, Ivan

    2015-05-21

    Hybrid halide perovskites that are currently intensively studied for photovoltaic applications, also present outstanding properties for light emission. Here, we report on the preparation of bright solid state light emitting diodes (LEDs) based on a solution-processed hybrid lead halide perovskite (Pe). In particular, we have utilized the perovskite generally described with the formula CH3NH3PbI(3-x)Cl(x) and exploited a configuration without electron or hole blocking layer in addition to the injecting layers. Compact TiO2 and Spiro-OMeTAD were used as electron and hole injecting layers, respectively. We have demonstrated a bright combined visible-infrared radiance of 7.1 W·sr(-1)·m(-2) at a current density of 232 mA·cm(-2), and a maximum external quantum efficiency (EQE) of 0.48%. The devices prepared surpass the EQE values achieved in previous reports, considering devices with just an injecting layer without any additional blocking layer. Significantly, the maximum EQE value of our devices is obtained at applied voltages as low as 2 V, with a turn-on voltage as low as the Pe band gap (V(turn-on) = 1.45 ± 0.06 V). This outstanding performance, despite the simplicity of the approach, highlights the enormous potentiality of Pe-LEDs. In addition, we present a stability study of unsealed Pe-LEDs, which demonstrates a dramatic influence of the measurement atmosphere on the performance of the devices. The decrease of the electroluminescence (EL) under continuous operation can be attributed to an increase of the non-radiative recombination pathways, rather than a degradation of the perovskite material itself.

  11. Composition and doping control for metal-organic chemical vapor deposition of InP-based double heterojunction bipolar transistor with hybrid base structure consisting of GaAsSb contact and InGaAsSb graded layers

    Science.gov (United States)

    Hoshi, Takuya; Kashio, Norihide; Sugiyama, Hiroki; Yokoyama, Haruki; Kurishima, Kenji; Ida, Minoru; Matsuzaki, Hideaki

    2017-07-01

    We report on a method for composition and doping control for metalorganic chemical vapor deposition of a double heterojunction bipolar transistor (DHBT) with a hybrid base structure consisting of a compositionally graded InGaAsSb for boosting an average electron velocity and a heavily doped thin GaAsSb for lowering the base contact resistivity. The GaAsSb contact layer can be formed by simply turning off the supply of In precursor tetramethylindium (TMIn) after the growth of the composition and doping graded InGaAsSb base. Consequently, the solid composition and hole concentration of hybrid base can be properly controlled by just modulating the supply of only TMIn and carbon tetrabromide. Secondary ion mass spectroscopy for the DHBT wafer reveals that the contents of In, Ga, and C inside the base are actually modulated from the collector side to the emitter side as expected. Transmission-line-model measurements were performed for the compositionally graded-InGaAsSb/GaAsSb hybrid base. The contact resistivity is estimated to be 5.3 Ω µm2, which is lower than half the value of a compositionally graded InGaAsSb base without the GaAsSb contact layer. The results indicate that the compositionally-graded-InGaAsSb/GaAsSb-contact hybrid base structure grown by this simple method is very advantageous for obtaining DHBTs with a very high maximum oscillation frequency.

  12. pH-dependent assembly of two inorganic-organic hybrid compounds based on octamolybdates: an unusual intercalated layer and a 3D 4-connected framework.

    Science.gov (United States)

    Liu, Hai-Yan; Yang, Jin; Liu, Ying-Ying; Ma, Jian-Fang

    2012-09-07

    Two novel inorganic-organic hybrid compounds based on octamolybdates, namely, [Cu(H(2)L)(2)(γ-Mo(8)O(26))]·(Mo(6)O(19))·2H(2)O (1) and [Cu(H(2)L)(γ-Mo(8)O(26))(H(2)O)(2)]·5H(2)O (2), where L = 1,1'-(1,5-pentanediyl)bis[2-(4-pyridyl)benzimidazole], have been successfully synthesized at different pH values under hydrothermal conditions. Compound 1, which is hydrothermally prepared at pH ≈ 3.5, exhibits an entirely new type of intercalated layer. The nanosized hexamolybdate anions as guests are introduced into the layers. When the pH value is adjusted to 2, a structurally-different complex 2 was obtained. Compound 2 shows a unique 3D 4-connected framework constructed by inorganic layers and H(2)L(2+) ligands as bridges. The two compounds were characterized by elemental analyses, IR spectra and TGA. In addition, the electrochemical properties of 1-modified carbon paste electrode (CPE) have also been investigated in 1 M H(2)SO(4) aqueous solution.

  13. Poly(Acrylic acid–Based Hybrid Inorganic–Organic Electrolytes Membrane for Electrical Double Layer Capacitors Application

    Directory of Open Access Journals (Sweden)

    Chiam-Wen Liew

    2016-05-01

    Full Text Available Nanocomposite polymer electrolyte membranes (NCPEMs based on poly(acrylic acid(PAA and titania (TiO2 are prepared by a solution casting technique. The ionic conductivity of NCPEMs increases with the weight ratio of TiO2.The highest ionic conductivity of (8.36 ± 0.01 × 10−4 S·cm−1 is obtained with addition of 6 wt % of TiO2 at ambient temperature. The complexation between PAA, LiTFSI and TiO2 is discussed in Attenuated total reflectance-Fourier Transform Infrared (ATR-FTIR studies. Electrical double layer capacitors (EDLCs are fabricated using the filler-free polymer electrolyte or the most conducting NCPEM and carbon-based electrodes. The electrochemical performances of fabricated EDLCs are studied through cyclic voltammetry (CV and galvanostatic charge-discharge studies. EDLC comprising NCPEM shows the specific capacitance of 28.56 F·g−1 (or equivalent to 29.54 mF·cm−2 with excellent electrochemical stability.

  14. High performance organic nonvolatile memory transistors based on HfO2 and poly(α-methylstyrene) electret hybrid charge-trapping layers

    Science.gov (United States)

    Xu, W. C.; He, H. X.; Jing, X. S.; Wu, S. J.; Zhang, Z.; Gao, J. W.; Gao, X. S.; Zhou, G. F.; Lu, X. B.; Liu, J.-M.

    2017-08-01

    In this work, we fabricated a high performance flash-type organic nonvolatile memory transistor, which adopted polymer-electret poly(α-methylstyrene) (PαMS) and HfO2 films as hybrid charge trapping layer (CTL). Compared with a single HfO2 or PαMS CTL structure, the hybrid HfO2/PαMS CTL structure can provide enhanced charge trapping efficiency to increase the device operation speed and reduce the leakage current to boost the device reliability. The fabricated nonvolatile organic memory transistors with the hybrid CTL shows excellent electrical properties, including low operation voltage (8 V), high speed (memories.

  15. Improving durability of hot forging tools by applying hybrid layers

    Directory of Open Access Journals (Sweden)

    Z. Gronostajski

    2015-10-01

    Full Text Available This paper deals with problems relating to the durability of the dies used for the hot forging of spur gears. The results of industrial tests carried out on dies with a hybrid layer (a nitrided layer (PN + physical vapor deposition (PVD coating applied to improve their durability are presented. Two types of hybrid layers, differing in their PVD coating, were evaluated with regard to their durability improvement effectiveness. The tests have shown that by applying hybrid layers of the nitrided layer/PVD coating type one can effectively increase the durability of hot forging tools.

  16. Photodiodes based in La0.7Sr0.3MnO3/single layer MoS2 hybrid vertical heterostructures

    Science.gov (United States)

    Niu, Yue; Frisenda, Riccardo; Svatek, Simon A.; Orfila, Gloria; Gallego, Fernando; Gant, Patricia; Agraït, Nicolás; Leon, Carlos; Rivera-Calzada, Alberto; Pérez De Lara, David; Santamaria, Jacobo; Castellanos-Gomez, Andres

    2017-09-01

    The fabrication of artificial materials by stacking of individual two-dimensional (2D) materials is amongst one of the most promising research avenues in the field of 2D materials. Moreover, this strategy to fabricate new man-made materials can be further extended by fabricating hybrid stacks between 2D materials and other functional materials with different dimensionality making the potential number of combinations almost infinite. Among all these possible combinations, mixing 2D materials with transition metal oxides can result especially useful because of the large amount of interesting physical phenomena displayed separately by these two material families. We present a hybrid device based on the stacking of a single layer MoS2 onto a lanthanum strontium manganite (La0.7Sr0.3MnO3) thin film, creating an atomically thin device. It shows a rectifying electrical transport with a ratio of 103, and a photovoltaic effect with V oc up to 0.4 V. The photodiode behaviour arises as a consequence of the different doping character of these two materials. This result paves the way towards combining the efforts of these two large materials science communities.

  17. In vitro remineralization of hybrid layers using biomimetic analogs.

    Science.gov (United States)

    Lin, Hui-Ping; Lin, Jun; Li, Juan; Xu, Jing-Hong; Mehl, Christian

    Resin-dentin bond degradation is a major cause of restoration failures. The major aim of the current study was to evaluate the impact of a remineralization medium on collagen matrices of hybrid layers of three different adhesive resins using nanotechnology methods. Coronal dentin surfaces were prepared from freshly extracted premolars and bonded to composite resin using three adhesive resins (FluoroBond II, Xeno-III-Bond, and iBond). From each tooth, two central slabs were selected for the study. The slabs used as controls were immersed in a simulated body fluid (SBF). The experimental slabs were immersed in a Portland cement-based remineralization medium that contained two biomimetic analogs (biomineralization medium (BRM)). Eight slabs per group were retrieved after 1, 2, 3, and 4 months, respectively and immersed in Rhodamine B for 24 h. Confocal laser scanning microscopy was used to evaluate the permeability of hybrid layers to Rhodamine B. Data were analyzed by analysis of variance (ANOVA) and Tukey's honest significant difference (HSD) tests. After four months, all BRM specimens exhibited a significantly smaller fluorescent area than SBF specimens, indicating a remineralization of the hybrid layer (P≤0.05). A clinically applicable biomimetic remineralization delivery system could potentially slow down bond degradation.

  18. In vitro remineralization of hybrid layers using biomimetic analogs*

    Science.gov (United States)

    Lin, Hui-ping; Lin, Jun; Li, Juan; Xu, Jing-hong; Mehl, Christian

    2016-01-01

    Resin-dentin bond degradation is a major cause of restoration failures. The major aim of the current study was to evaluate the impact of a remineralization medium on collagen matrices of hybrid layers of three different adhesive resins using nanotechnology methods. Coronal dentin surfaces were prepared from freshly extracted premolars and bonded to composite resin using three adhesive resins (FluoroBond II, Xeno-III-Bond, and iBond). From each tooth, two central slabs were selected for the study. The slabs used as controls were immersed in a simulated body fluid (SBF). The experimental slabs were immersed in a Portland cement-based remineralization medium that contained two biomimetic analogs (biomineralization medium (BRM)). Eight slabs per group were retrieved after 1, 2, 3, and 4 months, respectively and immersed in Rhodamine B for 24 h. Confocal laser scanning microscopy was used to evaluate the permeability of hybrid layers to Rhodamine B. Data were analyzed by analysis of variance (ANOVA) and Tukey’s honest significant difference (HSD) tests. After four months, all BRM specimens exhibited a significantly smaller fluorescent area than SBF specimens, indicating a remineralization of the hybrid layer (P≤0.05). A clinically applicable biomimetic remineralization delivery system could potentially slow down bond degradation. PMID:27819133

  19. Ca/Alq3 hybrid cathode buffer layer for the optimization of organic solar cells based on a planar heterojunction

    Science.gov (United States)

    El Jouad, Z.; Barkat, L.; Stephant, N.; Cattin, L.; Hamzaoui, N.; Khelil, A.; Ghamnia, M.; Addou, M.; Morsli, M.; Béchu, S.; Cabanetos, C.; Richard-Plouet, M.; Blanchard, P.; Bernède, J. C.

    2016-11-01

    Use of efficient anode cathode buffer layer (CBL) is crucial to improve the efficiency of organic photovoltaic cells. Here we show that using a double CBL, Ca/Alq3, allows improving significantly cell performances. The insertion of Ca layer facilitates electron harvesting and blocks hole collection, leading to improved charge selectivity and reduced leakage current, whereas Alq3 blocks excitons. After optimisation of this Ca/Alq3 CBL using CuPc as electron donor, it is shown that it is also efficient when SubPc is substituted to CuPc in the cells. In that case we show that the morphology of the SubPc layer, and therefore the efficiency of the cells, strongly depends on the deposition rate of the SubPc film. It is necessary to deposit slowly (0.02 nm/s) the SubPc films because at higher deposition rate (0.06 nm/s) the films are porous, which induces leakage currents and deterioration of the cell performances. The SubPc layers whose formations are kinetically driven at low deposition rates are more uniform, whereas those deposited faster exhibit high densities of pinholes.

  20. Very thin ITO/metal mesh hybrid films for a high-performance transparent conductive layer in GaN-based light-emitting diodes

    Science.gov (United States)

    Min, Jung-Hong; Kwak, Hoe-Min; Kim, Kiyoung; Jeong, Woo-Lim; Lee, Dong-Seon

    2017-01-01

    In this paper, we introduce very thin Indium tin oxide (ITO) layers (5, 10, and 15 nm) hybridized with a metal mesh to produce high-performance transparent conductive layers (TCLs) in near-ultraviolet light-emitting diodes (NUV LEDs). Using UV–vis–IR spectrometry, Hall measurement, and atomic force microscopy, we found that 10 nm was the optimal thickness for the very thin ITO layers in terms of outstanding transmittance and sheet resistance values as well as stable contact properties when hybridized with the metal mesh. The proposed layers showed a value of 4.56 Ω/□ for sheet resistance and a value of 89.1% for transmittance. Moreover, the NUV LEDs fabricated with the hybrid TCLs achieved ∼140% enhanced light output power compared to that of 150 nm thick ITO layers. Finally, to verify the practical usage of the TCLs for industrial applications, we packaged the NUV LED chips and obtained improved turn-on voltage (3.48 V) and light output power (∼116%) performance.

  1. Layered double hydroxides as electrode materials for Ni based batteries and as novel inorganic/organic hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Caravaggio, G.

    2002-07-01

    This study examined the electrochemical properties of layered double hydroxides (LDH) in half-cells to determine if they can be used in nickel-cadmium (Ni-Cd) and nickel-metal hydride (NiMH) batteries. The LDHs were prepared by coprecipitation and were characterized by X-ray diffraction analysis. The nickel-aluminium LDHs were found to be the most stable during potassium hydroxide electrolyte discharge because the aluminium acted in a two fold manner. The high charge to radius ratio increased the electrostatic interaction between the anions and the metal layers. The acidity of the hydroxyl groups was due to the high exchange of electrons. The powders had lower discharge capacity compared to commercial electrode materials because of their low density. The nickel-vanadium LDHs exchanged only up to 1.2 electrons and were stable only up to a maximum of 14 days in electrolytic solutions of the cells. Zinc-aluminium LDHs were also synthesized and intercalated with phenyl phosphonic acid or 1,4-phenylene bis phosphonic acid to create microporous materials. X-ray diffraction, infra-red spectroscopy and nuclear magnetic resonance was used to characterize the compounds and determine crystallographic spacing. Grafting of both phosphonates to the metal layers had occurred and both materials showed little or no microporosity.

  2. Layer-by-layer assembly of peptide based bioorganic–inorganic hybrid scaffolds and their interactions with osteoblastic MC3T3-E1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Romanelli, Steven M. [Fordham University Department of Chemistry, 441 East Fordham Road, Bronx, NY 10458 (United States); Fath, Karl R. [The City University of New York, Queens College, Department of Biology, 65-30 Kissena Blvd, Flushing, NY 11367 (United States); The Graduate Center, The City University of New York, 365 Fifth Avenue, NY 10016 (United States); Phekoo, Aruna P. [The City University of New York, Queens College, Department of Biology, 65-30 Kissena Blvd, Flushing, NY 11367 (United States); Knoll, Grant A. [Fordham University Department of Chemistry, 441 East Fordham Road, Bronx, NY 10458 (United States); Banerjee, Ipsita A., E-mail: banerjee@fordham.edu [Fordham University Department of Chemistry, 441 East Fordham Road, Bronx, NY 10458 (United States)

    2015-06-01

    In this work we have developed a new family of biocomposite scaffolds for bone tissue regeneration by utilizing self-assembled fluorenylmethyloxycarbonyl protected Valyl-cetylamide (FVC) nanoassemblies as templates. To tailor the assemblies for enhanced osteoblast attachment and proliferation, we incorporated (a) Type I collagen, (b) a hydroxyapatite binding peptide sequence (EDPHNEVDGDK) derived from dentin sialophosphoprotein and (c) the osteoinductive bone morphogenetic protein-4 (BMP-4) to the templates by layer-by-layer assembly. The assemblies were then incubated with hydroxyapatite nanocrystals blended with varying mass percentages of TiO{sub 2} nanoparticles and coated with alginate to form three dimensional scaffolds for potential applications in bone tissue regeneration. The morphology was examined by TEM and SEM and the binding interactions were probed by FITR spectroscopy. The scaffolds were found to be non-cytotoxic, adhered to mouse preosteoblast MC3T3-E1 cells and promoted osteogenic differentiation as indicated by the results obtained by alkaline phosphatase assay. Furthermore, they were found to be biodegradable and possessed inherent antibacterial capability. Thus, we have developed a new family of tissue-engineered biocomposite scaffolds with potential applications in bone regeneration. - Highlights: • Fmoc-val-cetylamide assemblies were used as templates. • Collagen, a short dentin sialophosphoprotein derived sequence and BMP-4 were incorporated. • Hydroxyapatite–TiO{sub 2} nanocomposite blends and alginate were incorporated. • The 3D scaffold biocomposites adhered to preosteoblasts and promoted osteoblast differentiation. • The biocomposites also displayed antimicrobial activity.

  3. Mechanical Properties of Layered Hybrid Fiber Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    YUAN Hai-qing; CHEN Jing-tao; ZHU Ji-dong

    2003-01-01

    To improve the mechanical properties of concrete,Layered Hybrid Fiber Reinforced Concrete (LHFRC) was developed in this paper.Through comparative tests,the effects of layered hybrid fibers on a series of mechanical properties of concrete were discussed.The mechanical properties include compressive strength,tensile strength,flexural strength,compressive stress-strain relationship,flexural toughness and cracking resistance of concrete.The testing results and analysis demonstrate that layered hybrid fibers can significantly improve the flexural strength,toughness and cracking resistance of concrete while the cost of concrete increases slightly.

  4. Hybrid window layer for photovoltaic cells

    Science.gov (United States)

    Deng, Xunming

    2010-02-23

    A novel photovoltaic solar cell and method of making the same are disclosed. The solar cell includes: at least one absorber layer which could either be a lightly doped layer or an undoped layer, and at least a doped window-layers which comprise at least two sub-window-layers. The first sub-window-layer, which is next to the absorber-layer, is deposited to form desirable junction with the absorber-layer. The second sub-window-layer, which is next to the first sub-window-layer, but not in direct contact with the absorber-layer, is deposited in order to have transmission higher than the first-sub-window-layer.

  5. Advances and Promises of Layered Halide Hybrid Perovskite Semiconductors.

    Science.gov (United States)

    Pedesseau, Laurent; Sapori, Daniel; Traore, Boubacar; Robles, Roberto; Fang, Hong-Hua; Loi, Maria Antonietta; Tsai, Hsinhan; Nie, Wanyi; Blancon, Jean-Christophe; Neukirch, Amanda; Tretiak, Sergei; Mohite, Aditya D; Katan, Claudine; Even, Jacky; Kepenekian, Mikaël

    2016-11-22

    Layered halide hybrid organic-inorganic perovskites (HOP) have been the subject of intense investigation before the rise of three-dimensional (3D) HOP and their impressive performance in solar cells. Recently, layered HOP have also been proposed as attractive alternatives for photostable solar cells and revisited for light-emitting devices. In this review, we combine classical solid-state physics concepts with simulation tools based on density functional theory to overview the main features of the optoelectronic properties of layered HOP. A detailed comparison between layered and 3D HOP is performed to highlight differences and similarities. In the same way as the cubic phase was established for 3D HOP, here we introduce the tetragonal phase with D4h symmetry as the reference phase for 2D monolayered HOP. It allows for detailed analysis of the spin-orbit coupling effects and structural transitions with corresponding electronic band folding. We further investigate the effects of octahedral tilting on the band gap, loss of inversion symmetry and possible Rashba effect, quantum confinement, and dielectric confinement related to the organic barrier, up to excitonic properties. Altogether, this paper aims to provide an interpretive and predictive framework for 3D and 2D layered HOP optoelectronic properties.

  6. Dissolution of Oxide Layer on Alloy 600 by HYBRID Solution

    Energy Technology Data Exchange (ETDEWEB)

    Won, H. J.; Lee, W. S.; Kim, S. B.; Park, S. Y.; Choi, W. K.; Moon, J. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The simulated oxide layer formed on Alloy 600 surface was efficiently dissolved by the successive applications of NP and HYBRID. The total concentration of HYBRID used for the dissolution of simulated oxide layer is below 0.2 wt%. From the test results, we can also infer that HYBRID does not cause any corrosion problem to Alloy 600. The simultaneous destruction of hydrazine and nitrate ion will greatly reduce the generation of the secondary waste. A feasibility study on the reduction of the generation of the secondary waste is performed.

  7. BI-LAYER HYBRID BIOCOMPOSITES: CHEMICAL RESISTANT AND PHYSICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Mohammad Jawaid,

    2012-02-01

    Full Text Available Bi-layer hybrid biocomposites were fabricated by hand lay-up technique by reinforcing oil palm empty fruit bunch (EFB and jute fibre mats with epoxy matrix. Hybrid composites were prepared by varying the relative weight fraction of the two fibres. The physical (void content, density, dimensional stability, and chemical resistant properties of hybrid composites were evaluated. When the jute fibre loading increased in hybrid composites, physical and chemical resistant properties of hybrid composites were enhanced. Void content of hybrid composites decreased with an increase in jute fibre loading because jute fibres showed better fibre/matrix interface bonding, which leads to a reduction in voids. The density of hybrid composite increased as the quantity of jute fibre loading increased. The hybridization of the jute fibres with EFB composite improved the dimensional stability of the hybrid composites. The performance of hybrid composites towards chemical reagents improved with an increase in jute fibre loading as compared to the EFB composite. The combination of oil palm EFB/jute fibres with epoxy matrix produced hybrid biocomposites material that is competitive to synthetic composites.

  8. Advances and Promises of Layered Halide Hybrid Perovskite Semiconductors

    NARCIS (Netherlands)

    Pedesseau, Laurent; Sapori, Daniel; Traore, Boubacar; Robles, Roberto; Fang, Hong-Hua; Loi, Maria Antonietta; Tsai, Hsinhan; Nie, Wanyi; Blancon, Jean-Christophe; Neukirch, Amanda; Tretiak, Sergei; Mohite, Aditya D.; Katan, Claudine; Even, Jacky; Kepenekian, Mikael

    2016-01-01

    Layered halide hybrid organic inorganic perovskites (HOP) have been the subject of intense investigation before the rise of three-dimensional (3D) HOP and their impressive performance in solar cells. Recently, layered HOP have also been proposed as attractive alternatives for photostable solar cells

  9. Advances and Promises of Layered Halide Hybrid Perovskite Semiconductors

    NARCIS (Netherlands)

    Pedesseau, Laurent; Sapori, Daniel; Traore, Boubacar; Robles, Roberto; Fang, Hong-Hua; Loi, Maria Antonietta; Tsai, Hsinhan; Nie, Wanyi; Blancon, Jean-Christophe; Neukirch, Amanda; Tretiak, Sergei; Mohite, Aditya D.; Katan, Claudine; Even, Jacky; Kepenekian, Mikael

    2016-01-01

    Layered halide hybrid organic inorganic perovskites (HOP) have been the subject of intense investigation before the rise of three-dimensional (3D) HOP and their impressive performance in solar cells. Recently, layered HOP have also been proposed as attractive alternatives for photostable solar cells

  10. Nitrogen-incorporated ultrananocrystalline diamond and multi-layer-graphene-like hybrid carbon films

    Science.gov (United States)

    Tzeng, Yonhua; Yeh, Shoupu; Fang, Wei Cheng; Chu, Yuehchieh

    2014-03-01

    Nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) and multi-layer-graphene-like hybrid carbon films have been synthesized by microwave plasma enhanced chemical vapor deposition (MPECVD) on oxidized silicon which is pre-seeded with diamond nanoparticles. MPECVD of N-UNCD on nanodiamond seeds produces a base layer, from which carbon structures nucleate and grow perpendicularly to form standing carbon platelets. High-resolution transmission electron microscopy and Raman scattering measurements reveal that these carbon platelets are comprised of ultrananocrystalline diamond embedded in multilayer-graphene-like carbon structures. The hybrid carbon films are of low electrical resistivity. UNCD grains in the N-UNCD base layer and the hybrid carbon platelets serve as high-density diamond nuclei for the deposition of an electrically insulating UNCD film on it. Biocompatible carbon-based heaters made of low-resistivity hybrid carbon heaters encapsulated by insulating UNCD for possible electrosurgical applications have been demonstrated.

  11. Bulk- and layer-heterojunction phototransistors based on poly [2-methoxy-5-(2′-ethylhexyloxy-p-phenylenevinylene)] and PbS quantum dot hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xiaoxian; Zhang, Yating, E-mail: yating@tju.edu.cn; Wang, Ran; Cao, Mingxuan; Che, Yongli; Wang, Jianlong; Wang, Haiyan; Jin, Lufan; Ding, Xin; Zhang, Guizhong; Yao, Jianquan [Institute of Laser and Opto-Electronics, College of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072 (China); Key Laboratory of Opto-Electronics Information Technology (Tianjin University), Ministry of Education, Tianjin 300072 (China); Dai, Haitao [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072 (China)

    2015-06-22

    The responsivity (R) of a thin film photodetector is proportional to the product of its photo-induced carrier density (n) and mobility (μ). However, when choosing between layer heterojunction (LH) and bulk heterojunction (BH) field-effect phototransistors (FEpTs), it is still unclear which of the two device structures is more conducive to photodetection. A comparison study is performed on the two structures based on polymer and PbS quantum dot hybrids. Both devices exhibit ambipolar behavior, with μ{sub E} ≈ μ{sub H} = 3.7 cm{sup 2} V{sup −1} s{sup −1} for BH-FEpTs and μ{sub H} = 36 cm{sup 2} V{sup −1} s{sup −1} and μ{sub E} = 52 cm{sup 2} V{sup −1} s{sup −1} for LH-FEpTs. Because of the improvements in μ and the channel order degree (α), the responsivity of LH-FEpTs is as high as 10{sup 1 }A/W, which is as much as two orders of magnitude higher than that of BH-FEpTs (10{sup −1}A/W) under the same conditions. Although the large area of the BH improves both the exciton separation degree (β) and n in the BH-FEpT, the lack of an effective transport mechanism becomes the main constraint on high device responsivity. Therefore, LH-FEpTs are better candidates for use as photo detectors, and a “three-high” principle of high α, β, and μ is found to be required for high responsivity.

  12. Hierarchical modeling and control of hybrid systems with two layers; Hierarchische Modellierung und Regelung hybrider Systeme auf zwei Ebenen

    Energy Technology Data Exchange (ETDEWEB)

    Stursberg, Olaf; Paschedag, Tina; Rungger, Matthias; Ding, Hao [Kassel Univ. (Germany). Fachgebiet Regelungs- und Systemtheorie

    2010-08-15

    While hybrid dynamic models are, to a certain degree, established for modeling systems with heterogeneous dynamics, most approaches for design and analysis of hybrid systems are restricted to monolithic models without hierarchy. This contribution first shows, how modular hybrid systems with two layers of decision, as appropriate for representing manufacturing systems for example, can be modeled systematically. The second part proposes a technique for fixing discrete inputs (for coordinating control) and continuous inputs (for embedded continuous controllers) in combination. The method uses a graph-based search on the upper decision layer, while principles of predictive control are used on the lower layer. The procedure of modeling and control is illustrated for a manufacturing process. (orig.)

  13. Synthesis of Polythiophene–Fullerene Hybrid Additives as Potential Compatibilizers of BHJ Active Layers

    Directory of Open Access Journals (Sweden)

    Sofia Kakogianni

    2016-12-01

    Full Text Available Perfluorophenyl functionalities have been introduced as side chain substituents onto regioregular poly(3-hexyl thiophene (rr-P3HT, under various percentages. These functional groups were then converted to azides which were used to create polymeric hybrid materials with fullerene species, either C60 or C70. The P3HT–fullerene hybrids thus formed were thereafter evaluated as potential compatibilizers of BHJ active layers comprising P3HT and fullerene based acceptors. Therefore, a systematic investigation of the optical and morphological properties of the purified polymer–fullerene hybrid materials was performed, via different complementary techniques. Additionally, P3HT:PC70BM blends containing various percentages of the herein synthesized hybrid material comprising rr-P3HT and C70 were investigated via Transmission Electron Microscopy (TEM in an effort to understand the effect of the hybrids as additives on the morphology and nanophase separation of this typically used active layer blend for OPVs.

  14. An On-Demand Retrieval Method Based on Hybrid NoSQL for Multi-Layer Image Tiles in Disaster Reduction Visualization

    Directory of Open Access Journals (Sweden)

    Linyao Qiu

    2017-01-01

    Full Text Available Monitoring, response, mitigation and damage assessment of disasters places a wide variety of demands on the spatial and temporal resolutions of remote sensing images. Images are divided into tile pyramids by data sources or resolutions and published as independent image services for visualization. A disaster-affected area is commonly covered by multiple image layers to express hierarchical surface information, which generates a large amount of namesake tiles from different layers that overlay the same location. The traditional tile retrieval method for visualization cannot distinguish between distinct layers and traverses all image datasets for each tile query. This process produces redundant queries and invalid access that can seriously affect the visualization performance of clients, servers and network transmission. This paper proposes an on-demand retrieval method for multi-layer images and defines semantic annotations to enrich the description of each dataset. By matching visualization demands with the semantic information of datasets, this method automatically filters inappropriate layers and finds the most suitable layer for the final tile query. The design and implementation are based on a two-layer NoSQL database architecture that provides scheduling optimization and concurrent processing capability. The experimental results reflect the effectiveness and stability of the approach for multi-layer retrieval in disaster reduction visualization.

  15. Fabrication of sensitive enzymatic biosensor based on multi-layered reduced graphene oxide added PtAu nanoparticles-modified hybrid electrode

    Science.gov (United States)

    Hossain, Md Faruk; Park, Jae Y.

    2017-01-01

    A highly sensitive amperometric glucose sensor was developed by immobilization of glucose oxidase (GOx) onto multi-layer reduced graphene oxide (MRGO) sheets decorated with platinum and gold flower-like nanoparticles (PtAuNPs) modified Au substrate electrode. The fabricated MRGO/PtAuNPs modified hybrid electrode demonstrated high electrocatalytic activities toward oxidation of H2O2, to which it had a wide linear response that ranged from 0.5 to 8 mM (R2 = 0.997), and high sensitivity of 506.25 μA/mMcm2. Furthermore, glucose oxidase-chitosan composite and cationic polydiallyldimethylammonium chloride (PDDA) were assembled by a casting method on the surface of MRGO/PtAuNPs modified electrode. This as-fabricated hybrid biosensor electrode exhibited high electrocatalytic activity for the detection of glucose in PBS. It demonstrated good analytical properties in terms of a low detection limit of 1 μM (signal-to-noise ratio of 3), short response time (3 s), high sensitivity (17.85 μA/mMcm2), and a wide linear range (0.01–8 mM) for glucose sensing. These results reveal that the newly developed sensing electrode offers great promise for new type enzymatic biosensor applications. PMID:28333943

  16. Multifunctional organic–inorganic hybrid nanoparticles and nanosheets based on chitosan derivative and layered double hydroxide: cellular uptake mechanism and application for topical ocular drug delivery

    Science.gov (United States)

    Chi, Huibo; Gu, Yan; Xu, Tingting; Cao, Feng

    2017-01-01

    To study the cellular uptake mechanism of multifunctional organic–inorganic hybrid nanoparticles and nanosheets, new chitosan–glutathione–valine–valine-layered double hydroxide (CG-VV-LDH) nanosheets with active targeting to peptide transporter-1 (PepT-1) were prepared, characterized and further compared with CG-VV-LDH nanoparticles. Both organic–inorganic hybrid nanoparticles and nanosheets showed a sustained release in vitro and prolonged precorneal retention time in vivo, but CG-VV-LDH nanoparticles showed superior permeability in the isolated cornea of rabbits than CG-VV-LDH nanosheets. Furthermore, results of cellular uptake on human corneal epithelial primary cells (HCEpiC) and retinal pigment epithelial (ARPE-19) cells indicated that both clathrin-mediated endocytosis and active transport of PepT-1 are involved in the internalization of CG-VV-LDH nanoparticles and CG-VV-LDH nanosheets. In summary, the CG-VV-LDH nanoparticle may be a promising carrier as a topical ocular drug delivery system for the treatment of ocular diseases of mid-posterior segments, while the CG-VV-LDH nanosheet may be suitable for the treatment of ocular surface diseases. PMID:28280329

  17. Motion Modeling of Crawling Robot Based on Layer Controlled Hybrid Petri Net%爬行机器人的分层可控混成Petri网建模研究

    Institute of Scientific and Technical Information of China (English)

    高庆吉; 武晓霞; 刘芳; 李万民

    2011-01-01

    飞机表面爬行机器人是一个复杂的离散事件和连续动态事件相结合的混成运动系统,为描述系统的静态特性和动态行为,提出一种分层可控混成Petri网模型.依据爬行运动机构定义了Petri网模型组成元素,建立了爬行机器人单轴和双轴分层可控混成Petri网,该模型可接收上层运动轨迹指令并输出爬行动作序列.实验表明,基于该模型实施的飞机模拟机舱表面爬行控制安全可靠,验证了模型的正确性和实用性.%In order to describe static characteristics and dynamic behavior of the crawling robot on the aircraft surface which is a complex hybrid motor system as a combination of discrete event and continuous events, the layer controlled hybrid Petri nets is proposed.The definition of constituent elements of the Petri net is given based on the crawling robot movement mechanism and then established single axis layer controlled hybrid Petri net and dual axis layer controlled hybrid Petri net of crawling robot, the model of which could receive the upper trajectory commands and outputs crawling action sequences. Experiments show that: the implementation of creeping control on simulate cabin of the aircraft based on the model was safe and reliable, so the correctness and practicability of the model is verified.

  18. Sensitivity enhancement of surface plasmon resonance sensor based on graphene-MoS{sub 2} hybrid structure with TiO{sub 2}-SiO{sub 2} composite layer

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, J.B.; Prajapati, Y.K. [Motilal Nehru National Institute of Technology, Electronics and Communication Engineering Department, Allahabad, Uttar Pradesh (India); Singh, V. [Banaras Hindu University, Department of Physics, Varanasi, Uttar Pradesh (India); Saini, J.P. [Bundelkhand Institute of Engineering and Technology, Electronics and Communication Engineering Department, Jhansi, Uttar Pradesh (India)

    2015-11-15

    In this paper, surface plasmon resonance (SPR) sensor based on graphene-MoS{sub 2} hybrid structure with composite layer of TiO{sub 2}-SiO{sub 2} is presented. The angular interrogation method is used for the analysis of reflected light from the sensor. For the calculation of the sensitivity, first of all the thicknesses of TiO{sub 2}, SiO{sub 2} and gold layers are optimized for the monolayer graphene and MoS{sub 2}. Thereafter, at these optimum thicknesses the reflectance curves are plotted for different sensor structure and comparison of change in resonance angle is made among these structures. It is observed that the sensitivity of the graphene-MoS{sub 2}-based sensor is enhanced by 9.24 % with respect conventional SPR sensor. The sensitivity is further enhanced by including TiO{sub 2}-SiO{sub 2} composite layer between prism base and metal layer and observed that the enhanced sensitivity for this sensor is 12.82 % with respect to conventional SPR sensor and 3.28 % with respect to graphene-MoS{sub 2}-based SPR sensor. At the end of this paper, the variation of the sensitivity and minimum reflectance is plotted with respect to sensing layer refractive index at the optimum thickness of all the layers and optimum number of MoS{sub 2} and graphene layers. It is also observed that four layers of MoS{sub 2} and monolayer graphene are best selection for the maximum enhancement of the sensitivity. (orig.)

  19. A hybrid base isolation system

    Energy Technology Data Exchange (ETDEWEB)

    Hart, G.C. [Univ. of California, Los Angeles, CA (United States); Lobo, R.F.; Srinivasan, M. [Hart Consultant Group, Santa Monica, CA (United States); Asher, J.W. [kpff Engineers, Santa Monica, CA (United States)

    1995-12-01

    This paper proposes a new analysis procedure for hybrid base isolation buildings when considering the displacement response of a base isolated building to wind loads. The system is considered hybrid because of the presence of viscous dampers in the building above the isolator level. The proposed analysis approach incorporates a detailed site specific wind study combined with a dynamic nonlinear analysis of the building response.

  20. Multifunctional organic–inorganic hybrid nanoparticles and nanosheets based on chitosan derivative and layered double hydroxide: cellular uptake mechanism and application for topical ocular drug delivery

    Directory of Open Access Journals (Sweden)

    Chi H

    2017-02-01

    Full Text Available Huibo Chi,1,2,* Yan Gu,1,* Tingting Xu,1 Feng Cao1 1Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing, 2State Key Laboratory of Drug Delivery Technology and Pharmacokinetics, Tianjin Institute of Pharmaceutical Research Co., Ltd., Tianjin, People’s Republic of China *These authors contributed equally to this work Abstract: To study the cellular uptake mechanism of multifunctional organic–inorganic hybrid nanoparticles and nanosheets, new chitosan–glutathione–valine–valine-layered double hydroxide (CG-VV-LDH nanosheets with active targeting to peptide transporter-1 (PepT-1 were prepared, characterized and further compared with CG-VV-LDH nanoparticles. Both organic–inorganic hybrid nanoparticles and nanosheets showed a sustained release in vitro and prolonged precorneal retention time in vivo, but CG-VV-LDH nanoparticles showed superior permeability in the isolated cornea of rabbits than CG-VV-LDH nanosheets. Furthermore, results of cellular uptake on human corneal epithelial primary cells (HCEpiC and retinal pigment epithelial (ARPE-19 cells indicated that both clathrin-mediated endocytosis and active transport of PepT-1 are involved in the internalization of CG-VV-LDH nanoparticles and CG-VV-LDH nanosheets. In summary, the CG-VV-LDH nanoparticle may be a promising carrier as a topical ocular drug delivery system for the treatment of ocular diseases of mid-posterior segments, while the CG-VV-LDH nanosheet may be suitable for the treatment of ocular surface diseases. Keywords: LDH nanoparticles, LDH nanosheets, ocular drug delivery, human corneal epithelial primary cell, retinal pigment cell, ARPE-19, active targeting

  1. Ferroelectrics based absorbing layers

    Science.gov (United States)

    Hao, Jianping; Sadaune, Véronique; Burgnies, Ludovic; Lippens, Didier

    2014-07-01

    We show that ferroelectrics-based periodic structure made of BaSrTiO3 (BST) cubes, arrayed onto a metal plate with a thin dielectric spacer film exhibit a dramatic enhancement of absorbance with value close to unity. The enhancement is found around the Mie magnetic resonance of the Ferroelectrics cubes with the backside metal layer stopping any transmitted waves. It also involves quasi-perfect impedance matching resulting in reflection suppression via simultaneous magnetic and electrical activities. In addition, it was shown numerically the existence of a periodicity optimum, which is explained from surface waves analysis along with trade-off between the resonance damping and the intrinsic loss of ferroelectrics cubes. An experimental verification in a hollow waveguide configuration with a good comparison with full-wave numerical modelling is at last reported by measuring the scattering parameters of single and dual BST cubes schemes pointing out coupling effects for densely packed structures.

  2. Epitaxially Grown Layered MFI–Bulk MFI Hybrid Zeolitic Materials

    KAUST Repository

    Kim, Wun-gwi

    2012-11-27

    The synthesis of hybrid zeolitic materials with complex micropore-mesopore structures and morphologies is an expanding area of recent interest for a number of applications. Here we report a new type of hybrid zeolite material, composed of a layered zeolite material grown epitaxially on the surface of a bulk zeolite material. Specifically, layered (2-D) MFI sheets were grown on the surface of bulk MFI crystals of different sizes (300 nm and 10 μm), thereby resulting in a hybrid material containing a unique morphology of interconnected micropores (∼0.55 nm) and mesopores (∼3 nm). The structure and morphology of this material, referred to as a "bulk MFI-layered MFI" (BMLM) material, was elucidated by a combination of XRD, TEM, HRTEM, SEM, TGA, and N2 physisorption techniques. It is conclusively shown that epitaxial growth of the 2-D layered MFI sheets occurs in at least two principal crystallographic directions of the bulk MFI crystal and possibly in the third direction as well. The BMLM material combines the properties of bulk MFI (micropore network and mechanical support) and 2-D layered MFI (large surface roughness, external surface area, and mesoporosity). As an example of the uses of the BMLM material, it was incorporated into a polyimide and fabricated into a composite membrane with enhanced permeability for CO2 and good CO2/CH4 selectivity for gas separations. SEM-EDX imaging and composition analysis showed that the polyimide and the BMLM interpenetrate into each other, thereby forming a well-adhered polymer/particle microstructure, in contrast with the defective interfacial microstructure obtained using bare MFI particles. Analysis of the gas permeation data with the modified Maxwell model also allows the estimation of the effective volume of the BMLM particles, as well as the CO2 and CH4 gas permeabilities of the interpenetrated layer at the BMLM/polyimide interface. © 2012 American Chemical Society.

  3. Fabrication of hierarchical hybrid structures using bio-enabled layer-by-layer self-assembly.

    Science.gov (United States)

    Hnilova, Marketa; Karaca, Banu Taktak; Park, James; Jia, Carol; Wilson, Brandon R; Sarikaya, Mehmet; Tamerler, Candan

    2012-05-01

    Development of versatile and flexible assembly systems for fabrication of functional hybrid nanomaterials with well-defined hierarchical and spatial organization is of a significant importance in practical nanobiotechnology applications. Here we demonstrate a bio-enabled self-assembly technique for fabrication of multi-layered protein and nanometallic assemblies utilizing a modular gold-binding (AuBP1) fusion tag. To accomplish the bottom-up assembly we first genetically fused the AuBP1 peptide sequence to the C'-terminus of maltose-binding protein (MBP) using two different linkers to produce MBP-AuBP1 hetero-functional constructs. Using various spectroscopic techniques, surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR), we verified the exceptional binding and self-assembly characteristics of AuBP1 peptide. The AuBP1 peptide tag can direct the organization of recombinant MBP protein on various gold surfaces through an efficient control of the organic-inorganic interface at the molecular level. Furthermore using a combination of soft-lithography, self-assembly techniques and advanced AuBP1 peptide tag technology, we produced spatially and hierarchically controlled protein multi-layered assemblies on gold nanoparticle arrays with high molecular packing density and pattering efficiency in simple, reproducible steps. This model system offers layer-by-layer assembly capability based on specific AuBP1 peptide tag and constitutes novel biological routes for biofabrication of various protein arrays, plasmon-active nanometallic assemblies and devices with controlled organization, packing density and architecture.

  4. Layered double oxide (LDO) particle containing photoreactive hybrid layers with tunable superhydrophobic and photocatalytic properties

    Science.gov (United States)

    Deák, Ágota; Janovák, László; Csapó, Edit; Ungor, Ditta; Pálinkó, István; Puskás, Sándor; Ördög, Tibor; Ricza, Tamás; Dékány, Imre

    2016-12-01

    Inorganic/organic hybrid layers have been prepared having superhydrophobic as well as photoreactive properties. The hybrid thin films with micro- and nanosized dual-scale surface roughness consist of ∼25 μm layered double oxide (LDO) photocatalyst particles and low surface energy poly(perfluorodecyl acrylate) [p(PFDAc)] fluoropolymer binder material. The application of [p(PFDAc)] resulted in the decrease in the surface free energy of the hydrophilic LDO. The structured surface LDO with ∼12% ZnO phase content were synthesized from layer double hydroxide (LDH) spheres. The determined excitation wavelength and the calculated band gap energy values were 386 nm and 3.23 eV, respectively. The hybrid thin films were prepared by a simple spray-coating method, which is a low-cost, fast and scalable film-forming technique. The surface roughness and also the wetting properties of the two-component hybrid layers proved to be finely adjustable by the LDO:fluoropolymer ratio. It was found that at 80-90 wt% LDO content, the thin films with a surface free energy value of ∼12 mJ/m2 displayed superhydrophobic behaviour (Θ > 150°) with satisfactory photocatalytic properties. This means special photoreactive surfaces with superhydrophobic properties instead of the conventional superhydropilic photocatalyst layers. According to the benzoic acid photodegradation test experiments of benzoic acid, the hybrid layers with 80-90 wt% LDO content photooxidized 22-24% of the initial test molecule concentration (0.17 g/L) under UV-A (λmax = 365 nm) illumination.

  5. DNA-based hybrid catalysis.

    Science.gov (United States)

    Rioz-Martínez, Ana; Roelfes, Gerard

    2015-04-01

    In the past decade, DNA-based hybrid catalysis has merged as a promising novel approach to homogeneous (asymmetric) catalysis. A DNA hybrid catalysts comprises a transition metal complex that is covalently or supramolecularly bound to DNA. The chiral microenvironment and the second coordination sphere interactions provided by the DNA are key to achieve high enantioselectivities and, often, additional rate accelerations in catalysis. Nowadays, current efforts are focused on improved designs, understanding the origin of the enantioselectivity and DNA-induced rate accelerations, expanding the catalytic scope of the concept and further increasing the practicality of the method for applications in synthesis. Herein, the recent developments will be reviewed and the perspectives for the emerging field of DNA-based hybrid catalysis will be discussed.

  6. Hybrid layer difference between sixth and seventh generation bonding agent

    Directory of Open Access Journals (Sweden)

    Grace Syavira Suryabrata

    2006-03-01

    Full Text Available Since etching is completed at the same stage as priming and bonding, when applying the sixth and seventh generation bonding, the exposed smear layers are constantly surrounded by primer and bonding and cannot collapse. The smear layer and the depth of penetration of resin bonding in dentinal tubules are completely integrated into hybrid layer. The purpose of this laboratory research was to study the penetration depth of two self etching adhesive. Fourteen samples of human extracted teeth were divided into two groups. Each groups consisted of seven samples, each of them was treated with sixth generation bonding agent and the other was treated with seventh generation bonding agent. The results disclosed that the penetration into dentinal tubules of seventh generation bonding agent was deeper than sixth generation bonding agent. Conclusion: bond strength will improve due to the increasing of penetration depth of resin bonding in dentinal tubules.

  7. Nanostructured solid-state hybrid photovoltaic cells fabricated by electrostatic layer-by-layer deposition

    Science.gov (United States)

    Kniprath, Rolf; McLeskey, James T.; Rabe, Jürgen P.; Kirstein, Stefan

    2009-06-01

    We report on the fabrication of hybrid organic/inorganic photovoltaic cells utilizing layer-by-layer deposition of water-soluble polyions and nanocrystals. A bulk heterojunction structure was created consisting of alternating layers of the p-conductive polythiophene derivative poly[2-(3-thienyl)-ethoxy-4-butylsulfonate] and n-conductive TiO2 nanoparticles. We fabricated working devices with the heterostructure sandwiched between suitable charge carrier blocking layers and conducting oxide and metal electrodes, respectively. We analyzed the influence of the thickness and nanostructure of the active layer on the cell performance and characterized the devices in terms of static and transient current response with respect to illumination and voltage conditions. We observed reproducible and stable photovoltaic behavior with photovoltages of up to 0.9 V.

  8. Optimization of hybrid antireflection structure integrating surface texturing and multi-layer interference coating

    Science.gov (United States)

    Kubota, Shigeru; Kanomata, Kensaku; Suzuki, Takahiko; Hirose, Fumihiko

    2014-10-01

    The antireflection structure (ARS) for solar cells is categorized to mainly two different techniques, i.e., the surface texturing and the single or multi-layer antireflection interference coating. In this study, we propose a novel hybrid ARS, which integrates moth eye texturing and multi-layer coat, for application to organic photovoltaics (OPVs). Using optical simulations based on the finite-difference time-domain (FDTD) method, we conduct nearly global optimization of the geometric parameters characterizing the hybrid ARS. The proposed optimization algorithm consists of two steps: in the first step, we optimize the period and height of moth eye array, in the absence of multi-layer coating. In the second step, we optimize the whole structure of hybrid ARS by using the solution obtained by the first step as the starting search point. The methods of the simple grid search and the Hooke and Jeeves pattern search are used for global and local searches, respectively. In addition, we study the effects of deviations in the geometric parameters of hybrid ARS from their optimized values. The design concept of hybrid ARS is highly beneficial for broadband light trapping in OPVs.

  9. Negative infrared photocurrent response in layered WS{sub 2}/reduced graphene oxide hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Ratha, Satyajit; Rout, Chandra Sekhar, E-mail: datta099@gmail.com, E-mail: csrout@iitbbs.ac.in [School of Basic Sciences, Indian Institute of Technology, Bhubaneswar 751013 (India); Simbeck, Adam J. [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Late, Dattatray J., E-mail: datta099@gmail.com, E-mail: csrout@iitbbs.ac.in [CSIR-National Chemical Laboratory, Physical and Materials Chemistry Division, Dr. Homi Bhabha Road, Pune 411008 (India); Nayak, Saroj K. [School of Basic Sciences, Indian Institute of Technology, Bhubaneswar 751013 (India); Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2014-12-15

    We report high performance IR photocurrent response of two-dimensional hybrid materials consisting of layered WS{sub 2} nanosheets and reduced graphene oxide (RGO). Comparative photocurrent response studies of WS{sub 2} nanosheets, RGO, and WS{sub 2}/RGO hybrids were carried out by performing current-voltage (I-V) and time-dependent current measurements with a laser excitation source having a wavelength of 808 nm. The experimental investigations indicate that WS{sub 2}/RGO hybrids show negative photocurrent response, whereas WS{sub 2} and RGO show positive photocurrent response. The negative photocurrent response of the WS{sub 2}/RGO hybrids is explained using a band alignment diagram and attributed to a charge transfer mechanism between WS{sub 2} and RGO. This analysis is further corroborated by first-principles density functional calculations. The fabricated device based on WS{sub 2}/RGO hybrids shows a photosensitivity R{sub λ} of about 6 AW{sup −1} and a quantum efficiency η of ∼924%, which demonstrates high sensitivity of the hybrid material towards IR detection. WS{sub 2}/RGO hybrids are therefore promising candidates for potential applications in optoelectronic circuits and low cost, high performance, and reliable photodetectors.

  10. Immobilization of laccase on hybrid layered double hydroxide

    Directory of Open Access Journals (Sweden)

    David Isidoro Camacho Córdova

    2009-01-01

    Full Text Available Crystals of Mg/Al layered double hydroxide were synthesized by alkaline precipitation and treated in an aqueous solution of glutamic acid. The glutamate ions were not intercalated into the interlayer space, but were detected in the material by Fourier transform infrared spectroscopy, suggesting that only the external surfaces of crystals were modified with glutamate ions. The resulting hybrid material was tested as a support for immobilization of the enzyme laccase (Myceliophthora thermophila. The immobilized enzyme preparation was characterized by electronic paramagnetic resonance spectroscopy and by assays of catalytic activity. The activity of the immobilized laccase was 97% of the activity in the free enzyme. Layered double hydroxide is a suitable support for use in remediation of soil studies.

  11. Layered nickel based superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Ronning, Filip [Los Alamos National Laboratory; Bauer, Eric D [Los Alamos National Laboratory; Park, Tuson [Los Alamos National Laboratory; Kurita, Nobuyuki [Los Alamos National Laboratory; Klimczuk, T [Los Alamos National Laboratory; Movshovich, R [Los Alamos National Laboratory; Thompson, J D [Los Alamos National Laboratory; Sefat, A S [ORNL; Mandrus, D [ORNL

    2009-01-01

    We review the properties of Ni-based superconductors which contain Ni{sub 2}X{sub 2} (X=As, P, Bi, Si, Ge, B) planes, a common structural element to the recently discovered FeAs superconductors. We also compare the properties ofthe Ni-and Fe-based systems from a perspective ofelectronic structure as well as structure-property relations.

  12. A novel protection layer of superconducting microwave circuits toward a hybrid quantum system

    CERN Document Server

    Lee, Jongmin

    2014-01-01

    We propose a novel multilayer structure based on Bragg layers that can protect a superconducting microwave resonator from photons and blackbody radiation and have little effect on its quality factor. We also discuss a hybrid quantum system exploiting a superconducting microwave circuit and a two-color evanescent field atom trap, where surface-scattered photons and absorption-induced broadband blackbody radiation might deteriorate the system.

  13. Hybrid polymer composites reinforced by layered silicate and laser synthesized nanocarbons

    Science.gov (United States)

    Dinca, I.; Stefan, A.; Serghie, C.; Moga, A.; Dumitrache, L.; Vuluga, Z.; Donescu, D.; Dragomirescu, A.; Prodan, G.; Ciupina, V.; Gavrila-Florescu, L.; Popovici, E.; Sandu, I.

    2007-12-01

    The work presents some preliminary results obtained in the attempt to perform hybrid polymer-based nanocomposites with laser synthesized carbon nanostructures and layered silicate. The preliminary results suggest that there is a close relation between the improved characteristics of the obtained nanocomposite and filler's properties. Laser synthesized nanocarbons, from almost amorphous up to fullerenic-like structure were used. As layered silicate, a modified Cloisite-type montmorillonite is mentioned. Preliminary results suggest that some of these addition agents lead to samples of nanocomposites with significant improvement of their aimed properties.

  14. Capacity Configuration of Hybrid Energy Storage System Based on Double Layer Power Decomposition%基于双层功率分解的混合储能系统容量配置

    Institute of Scientific and Technical Information of China (English)

    王跃; 吕林; 朱雨薇

    2016-01-01

    为风电场配置合适的储能系统可以平抑风电有功功率波动、提高系统电能质量。基于风电出力历史数据,提出了双层功率分解方法。第1层采用滑动平均法,在满足国家规定的风电并网要求下,分解出并网功率和混合储能系统的参考功率。第2层采用频谱分析方法,基于混合储能系统参考功率,利用傅里叶变换将其分解为低频分量和高频分量,分别分配给蓄电池和超级电容器吸收。考虑储能设备的荷电状态和蓄电池的循环使用寿命,建立混合储能系统容量配置模型,模型以其年综合成本最小为优化目标。仿真结果验证了双层功率分解方法的可行性,证明了混合储能系统较单类型储能系统在性能上和经济上的优越性。%Suitable energy storage can be configured for the wind power plant to stabilize the fluctuations of wind power and improve the power quality of wind power. Based on the historical data of wind power output, this paper proposes a double layer power decomposition method. The first layer adopts moving average method to decompose the power of the grid-connected power and hybrid energy storage system, according to the wind power grid connected indicators in China. The second layer uses spectrum analysis method and Fourier transform to decompose the reference power of hybrid energy storage system into low frequency component and high frequency component, which are distributed to the battery and the super capacitor, respectively. Considering the state of charge of energy storage equipment and the cycle life of the battery, this paper establishes the capacity optimization model of the hybrid energy storage system, which takes the minimum annual comprehensive cost as the optimization goal. The simulation results verify the feasibility of the double layer power decomposition method, and prove that the hybrid energy storage system is superior to the single type energy

  15. 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.

  16. Organic ferroelectric/semiconducting nanowire hybrid layer for memory storage

    Science.gov (United States)

    Cai, Ronggang; Kassa, Hailu G.; Haouari, Rachid; Marrani, Alessio; Geerts, Yves H.; Ruzié, Christian; van Breemen, Albert J. J. M.; Gelinck, Gerwin H.; Nysten, Bernard; Hu, Zhijun; Jonas, Alain M.

    2016-03-01

    Ferroelectric materials are important components of sensors, actuators and non-volatile memories. However, possible device configurations are limited due to the need to provide screening charges to ferroelectric interfaces to avoid depolarization. Here we show that, by alternating ferroelectric and semiconducting nanowires over an insulating substrate, the ferroelectric dipole moment can be stabilized by injected free charge carriers accumulating laterally in the neighboring semiconducting nanowires. This lateral electrostatic coupling between ferroelectric and semiconducting nanowires offers new opportunities to design new device architectures. As an example, we demonstrate the fabrication of an elementary non-volatile memory device in a transistor-like configuration, of which the source-drain current exhibits a typical hysteretic behavior with respect to the poling voltage. The potential for size reduction intrinsic to the nanostructured hybrid layer offers opportunities for the development of strongly miniaturized ferroelectric and piezoelectric devices.Ferroelectric materials are important components of sensors, actuators and non-volatile memories. However, possible device configurations are limited due to the need to provide screening charges to ferroelectric interfaces to avoid depolarization. Here we show that, by alternating ferroelectric and semiconducting nanowires over an insulating substrate, the ferroelectric dipole moment can be stabilized by injected free charge carriers accumulating laterally in the neighboring semiconducting nanowires. This lateral electrostatic coupling between ferroelectric and semiconducting nanowires offers new opportunities to design new device architectures. As an example, we demonstrate the fabrication of an elementary non-volatile memory device in a transistor-like configuration, of which the source-drain current exhibits a typical hysteretic behavior with respect to the poling voltage. The potential for size reduction

  17. OPTIMISATION OF BUFFER SIZE FOR ENHANCING QOS OF VIDEO TRAFFIC USING CROSS LAYERED HYBRID TRANSPORT LAYER PROTOCOL APPROACH

    Directory of Open Access Journals (Sweden)

    S. Matilda

    2011-03-01

    Full Text Available Video streaming is gaining importance, with the wide popularity of multimedia rich applications in the Internet. Video streams are delay sensitive and require seamless flow for continuous visualization. Properly designed buffers offer a solution to queuing delay. The diagonally opposite QoS metrics associated with video traffic poses an optimization problem, in the design of buffers. This paper is a continuation of our previous work [1] and deals with the design of buffers. It aims at finding the optimum buffer size for enhancing QoS offered to video traffic. Network-centric QoS provisioning approach, along with hybrid transport layer protocol approach is adopted, to arrive at an optimum size which is independent of RTT. In this combinational approach, buffers of routers and end devices are designed to satisfy the various QoS parameters at the transport layer. OPNET Modeler is used to simulate environments for testing the design. Based on the results of simulation it is evident that the hybrid transport layer protocol approach is best suited for transmitting video traffic as it supports the economical design.

  18. Electrical Double-Layer Capacitors in Hybrid Topologies —Assessment and Evaluation of Their Performance

    Directory of Open Access Journals (Sweden)

    Joeri Van Mierlo

    2012-11-01

    Full Text Available PHEVs and BEVs make use of battery cells optimized for high energy rather than for high power. This means that the power abilities of these batteries are limited. In order to enhance their performance, a hybrid Rechargeable Energy Storage System (RESS architecture can be used combining batteries with electrical-double layer capacitors (EDLCs. Such a hybridized architecture can be accomplished using passive or active systems. In this paper, the characteristics of these topologies have been analyzed and compared based on a newly developed hybridization simulation tool for association of lithium-ion batteries and EDLCs. The analysis shows that the beneficial impact of the EDLCs brings about enhanced battery performances in terms of energy efficiency and voltage drops, rather than extension of vehicle range. These issues have been particularly studied for the passive and active hybrid topologies. The classical passive and active topologies being expensive and less beneficial in term of cost, volume and weight, a new hybrid configuration based on the parallel combination of lithium-ion and EDLCs on cell level has been proposed in this article. This topology allows reducing cost, volume, and weight and system complexity in a significant way. Furthermore, a number of experimental setups have illustrated the power of the novel topology in terms of battery capacity increase and power capabilities during charging and discharging. Finally, a unique cycle life test campaign demonstrated that the lifetime of highly optimized lithium-ion batteries can be extended up to 30%–40%.

  19. Optimalization activity of ZnO NR/TiO2 NR-P3HT as an active layer based on hybrid bulk heterojunction on dye sensitized solar cell (DSSC)

    Science.gov (United States)

    Saputri, Liya Nikmatul Maula Zulfa; Ramelan, Ari Handono; Hanif, Qonita Awliya; Hasanah, Yesi Ihdina Fityatal; Prajanira, Lau Bekti; Wahyuningsih, Sayekti

    2016-04-01

    Dye sensitized solar cell (DSSC) with metal inorganic and conjugated organic polymer mixture, ZnO NR/TiO2 NR-P3HT as an active layer based on hybrid bulk heterojunction has been studied. The hybrid material was used to optimize DSSC performs for better efficiency than only TiO2 as an electrode. Synthesis of TiO2 nanorods (NR) was conducted by ball milling 1000 rpm for 4 hours and strong base reaction by hydrothermal process at 120 °C overnight. And the ZnO NR was synthesized from Zn(NO3)2.4H2O precusor by hydrotermal process at 90 °C for 5 hours and calcined on various temperature s of 400, 600, and 800 °C. ZnO NR was coated into an Tndium Tin Oxide (TTO) glass to collecting electron s effectively, where TiO2 NR were incorporated with poly(3 -hexylthiophene) (P3HT) on various concentration s of 5, 10, 15 mg/mL to obtain a larger surface area. Material characterization were performed by X -Ray Diffraction (XRD) and Uv-Vis spectrophotometer. For an application of DSSC were measured by T-V Keithley Multimeter and the efficiency of DSSC at various P3HT's concentrations of 5, 10, 15 mg/mL were 7.44 × 10-3, 0.0114, 0.0104, respectively. The maximum efficiency of DSSC was showed when TiO2 NR-P3HT's concentration was 10 mg/mL.

  20. Near Room-Temperature Memory Devices Based on Hybrid Spin-Crossover@SiO2 Nanoparticles Coupled to Single-Layer Graphene Nanoelectrodes.

    Science.gov (United States)

    Holovchenko, Anastasia; Dugay, Julien; Giménez-Marqués, Mónica; Torres-Cavanillas, Ramón; Coronado, Eugenio; van der Zant, Herre S J

    2016-09-01

    The charge transport properties of SCO [Fe(Htrz)2 (trz)](BF4 ) NPs covered with a silica shell placed in between single-layer graphene electrodes are reported. A reproducible thermal hysteresis loop in the conductance above room-temperature is evidenced. This bistability combined with the versatility of graphene represents a promising scenario for a variety of technological applications but also for future sophisticated fundamental studies.

  1. Building 3D Layer-by-Layer Graphene-Gold Nanoparticle Hybrid Architecture with Tunable Interlayer Distance

    Science.gov (United States)

    2014-06-26

    the entire surface of graphene within such 3D layer-by-layer hybrid nanomaterials would be exposed to electrolyte ions to facilitate the charging...B.; Li, Y. L.; Li, Y. M.; Li, J. H.; Deng, Z. X. Noncovalent DNA decorations of graphene oxide and reduced graphene oxide toward water -soluble metal...Building 3D Layer-by-Layer Graphene −Gold Nanoparticle Hybrid Architecture with Tunable Interlayer Distance Chenming Xue,† Min Gao,† Yuhua Xue,‡ Lin

  2. Spectroscopic, morphological and electrochromic characterization of layer-by-layer hybrid films of polyaniline and hexaniobate nanoscrolls

    OpenAIRE

    Silva, Claudio H. B.; Galiote, Nelson A.; Huguenin,Fritz; Teixeira-Neto, Erico; Constantino, Vera R. L.; Marcia L. A. Temperini

    2012-01-01

    The combination of semiconducting oxides and polyaniline in the nanoscale range may result in hybrid materials having enhanced properties, such as electrochromism and charge capacity. This paper reports the spectroscopic, morphological and electrochromic characterization of hybrid films made up of hexaniobate one-dimensional (1D) nanoscrolls and polyaniline prepared by the layer-by-layer assembly technique (LbL). Secondary electron imaging and backscattered electron imaging techniques perform...

  3. Hybrid silicon plasmonic organic directional coupler-based modulator

    Science.gov (United States)

    Abdelatty, M. Y.; Zaki, A. O.; Swillam, M. A.

    2017-01-01

    An optical directional coupler (ODC)-based hybrid plasmonic waveguide is designed and demonstrated with a power splitting mechanism that can be tuned by applying an external electric field. The tuning mechanism takes the advantage of electro-optic properties of the embedded polymer layer. The ODC operates under 1550 nm telecommunication wavelength. A finite element method with a perfect matching layer, absorbing boundary condition, is taken up to simulate and analyze the ODC.

  4. A Hybrid Numerical Method for Turbulent Mixing Layers. Degree awarded by Case Western Reserve Univ.

    Science.gov (United States)

    Georgiadis, Nicholas J.

    2001-01-01

    A hybrid method has been developed for simulations of compressible turbulent mixing layers. Such mixing layers dominate the flows in exhaust systems of modern day aircraft and also those of hypersonic vehicles currently under development. The method configurations in which a dominant structural feature provides an unsteady mechanism to drive the turbulent development in the mixing layer. The hybrid method uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall bounded regions entering a mixing section, and a Large Eddy Simulation (LES) procedure to calculate the mixing dominated regions. A numerical technique was developed to enable the use of the hybrid RANS-LES method on stretched, non-Cartesian grids. Closure for the RANS equations was obtained using the Cebeci-Smith algebraic turbulence model in conjunction with the wall-function approach of Ota and Goldberg. The wall-function approach enabled a continuous computational grid from the RANS regions to the LES region. The LES equations were closed using the Smagorinsky subgrid scale model. The hybrid RANS-LES method is applied to a benchmark compressible mixing layer experiment. Preliminary two dimensional calculations are used to investigate the effects of axial grid density and boundary conditions. Vortex shedding from the base region of a splitter plate separating the upstream flows was observed to eventually transition to turbulence. The location of the transition, however, was much further downstream than indicated by experiments. Actual LES calculations, performed in three spatial directions, also indicated vortex shedding, but the transition to turbulence was found to occur much closer to the beginning of the mixing section. which is in agreement with experimental observations. These calculations demonstrated that LES simulations must be performed in three dimensions. Comparisons of time-averaged axial velocities and turbulence intensities indicated reasonable agreement with experimental

  5. Hybrid layer thickness and morphology: Influence of cavity preparation with air abrasion.

    Science.gov (United States)

    Barceleiro, Marcos Oliveira; de Mello, Jose Benedicto; Porto, Celso Luis de Angelis; Dias, Katia Regina Hostilio Cervantes; de Miranda, Mauro Sayao

    2011-01-01

    Dentinal surfaces prepared with air abrasion have considerably different characteristics from those prepared with conventional instruments. Different hybrid layer morphology and thickness occur, which can result in differences in the quality of restorations placed on dentinal surfaces prepared with a diamond bur compared to surfaces prepared using air abrasion. The objective of this study was to compare the hybrid layer thickness and morphology formed utilizing Scotchbond Multi-Purpose Plus (SBMP) on dentin prepared with a diamond bur in a high-speed handpiece and on dentin prepared using air abrasion. Flat dentin surfaces obtained from five human teeth were prepared using each method, then treated with the dentin adhesive system according to manufacturer's instructions. After a layer of composite was applied, specimens were sectioned, flattened, polished, and prepared for scanning electron microscopy. Ten different measurements of hybrid layer thickness were obtained along the bonded surface in each specimen. SBMP produced a 3.43 ± 0.75 µm hybrid layer in dentin prepared with diamond bur. This hybrid layer was regular and found consistently. In the air abrasion group, SBMP produced a 4.94 ± 1.28 µm hybrid layer, which was regular and found consistently. Statistical ANOVA (P = 0.05) indicated that there was a statistically significant difference between the groups. These data indicate that the air abrasion, within the parameters used in this study, provides a thick hybrid layer formation.

  6. Cluster Tree Based Hybrid Document Similarity Measure

    Directory of Open Access Journals (Sweden)

    M. Varshana Devi

    2015-10-01

    Full Text Available based hybrid similarity measure is established to measure the hybrid similarity. In cluster tree, the hybrid similarity measure can be calculated for the random data even it may not be the co-occurred and generate different views. Different views of tree can be combined and choose the one which is significant in cost. A method is proposed to combine the multiple views. Multiple views are represented by different distance measures into a single cluster. Comparing the cluster tree based hybrid similarity with the traditional statistical methods it gives the better feasibility for intelligent based search. It helps in improving the dimensionality reduction and semantic analysis.

  7. Investigation of the influence of hybrid layers on the life time of hot forging dies

    OpenAIRE

    Legutko, S.; Meller, A.; Gajek, M.

    2013-01-01

    The paper deals with the issues related in the process of drop forging with special attention paid to the durability of forging tools. It presents the results of industrial investigation of the influence of hybrid layers on hot forging dies. The effectiveness of hybrid layers type nitrided layer/PVD coating applied for extending the life of forging tools whose working surfaces are exposed to such complex exploitation conditions as, among others, cyclically varying high thermal and mechanical ...

  8. Thin hybrid pixel assembly fabrication development with backside compensation layer

    Science.gov (United States)

    Bates, R.; Buttar, C.; McMullen, T.; Cunningham, L.; Ashby, J.; Doherty, F.; Pares, G.; Vignoud, L.; Kholti, B.; Vahanen, S.

    2017-02-01

    The ATLAS and CMS experiments will both replace their entire tracking systems for operation at the HL-LHC in 2026. This will include a significantly larger pixel systems, for example, for ATLAS approximately 15 m2. To keep the tracker material budget low it is crucial to minimize the mass of the pixel modules via thinning both the sensor and readout chip to about 150 μm each. The bump yield of thin module assemblies using solder based bump bonding can be problematic due to wafer bowing during solder reflow at high temperature. A new bump-bonding process using backside compensation on the readout chip to address the issue of low yield will be presented. The objective is to compensate dynamically the stress of the front side stack by adding a compensating layer to the backside of the wafer. A SiN and Al:Si stack has been chosen for the backside layer. The bow reducing effect of applying a backside compensation layer will be demonstrated using the FE-I4 wafer. The world's first results from assemblies produced from readout wafers thinned to 100 μm with a stress compensation layer are presented with bond yields close to 100% measured using the FE-I4 readout chip.

  9. Overestimating hybrid layer quality in polished adhesive/dentin interfaces.

    Science.gov (United States)

    Wang, Yong; Spencer, Paulette

    2004-03-15

    The most popular techniques for determining the quality of the hybrid layer (HL) have relied on morphologic characterization of the polished adhesive/dentin (a/d) interfaces before and after acid-bleach chemical treatment. Using these techniques, the existence of smooth, acid-resistant layers has been consistently reported for most adhesive systems. The purpose of this study was to determine whether popular specimen preparation techniques that include polishing and acid-bleach treatment modify the a/d interface, mask the complexity of the HL, and lead to inaccurate assessment of the quality of the HL. To understand the impact of specimen preparation techniques on the morphology of the resin-dentin interface, polished and unpolished specimens from the same tooth were closely compared after different acid-bleach chemical treatment procedures. Two one-bottle adhesives, that is, 3M Single Bond and Pulpdent UNO, exhibiting distinct differences in hydrophilic/hydrophobic composition, were used in this investigation. Using specimens from the same tooth, the effect of chemical treatments on the morphology of the resin-dentin interdiffusion zone and the differences in the morphology of polished and unpolished specimens after these same treatments were studied with scanning electron microscopy. It was shown that conventional specimen preparation techniques that include polishing and acid-bleach treatment can adversely affect and even obscure the structural detail of the a/d interface in specimens that possess a porous HL. The results indicated that the Pulpdent UNO/dentin interface had better quality than the 3M Single Bond/dentin interface. The difference in the quality of HL can be attributed to factors such as compositional differences that impact the adhesive interaction with water, that is present within the substrate during wet bonding. The inability of the conventional acid-bleach procedure to reveal the differences in the scanning electron microscopy interfacial

  10. Hybrid lipid-based nanostructures

    Science.gov (United States)

    Dayani, Yasaman

    Biological membranes serve several important roles, such as structural support of cells and organelles, regulation of ionic and molecular transport, barriers to non-mediated transport, contact between cells within tissues, and accommodation of membrane proteins. Membrane proteins and other vital biomolecules incorporated into the membrane need a lipid membrane to function. Due to importance of lipid bilayers and their vital function in governing many processes in the cell, the development of various models as artificial lipid membranes that can mimic cell membranes has become a subject of great interest. Using different models of artificial lipid membranes, such as liposomes, planar lipid bilayers and supported or tethered lipid bilayers, we are able to study many biophysical processes in biological membranes. The ability of different molecules to interact with and change the structure of lipid membranes can be also investigated in artificial lipid membranes. An important application of lipid bilayer-containing interfaces is characterization of novel membrane proteins for high throughput drug screening studies to investigate receptor-drug interactions and develop biosensor systems. Membrane proteins need a lipid bilayer environment to preserve their stability and functionality. Fabrication of materials that can interact with biomolecules like proteins necessitates the use of lipid bilayers as a mimic of cell membranes. The objective of this research is to develop novel hybrid lipid-based nanostructures mimicking biological membranes. Toward this aim, two hybrid biocompatible structures are introduced: lipid bilayer-coated multi-walled carbon nanotubes (MWCNTs) and hydrogel-anchored liposomes with double-stranded DNA anchors. These structures have potential applications in biosensing, drug targeting, drug delivery, and biophysical studies of cell membranes. In the first developed nanostructure, lipid molecules are covalently attached to the surfaces of MWCNTs, and

  11. Imperfect hybrid layers created by an aggressive one-step self-etch adhesive in primary dentin are amendable to biomimetic remineralization in vitro

    Science.gov (United States)

    Kim, Jongryul; Vaughn, Ryan M.; Gu, Lisha; Rockman, Roy A.; Arola, Dwayne D.; Schafer, Tara E.; Choi, Kyungkyu; Pashley, David H.; Tay, Franklin R.

    2009-01-01

    Degradation of hybrid layers created in primary dentin occurs as early as 6 months in vivo. Biomimetic remineralization utilizes “bottom-up” nanotechnology principles for interfibrillar and intrafibrillar remineralization of collagen matrices. This study examined whether imperfect hybrid layers created in primary dentin can be remineralized. Coronal dentin surfaces were prepared from extracted primary molars and bonded using Adper Prompt L-Pop and a composite. One millimeter-thick specimen slabs of the resin-dentin interface were immersed in a Portland cement-based remineralization medium that contained two biomimetic analogs to mimic the sequestration and templating functions of dentin noncollagenous proteins. Specimens were retrieved after 1–6 months. Confocal laser scanning microscopy was employed for evaluating the permeability of hybrid layers to Rhodamine B. Transmission electron microscopy was used to examine the status of remineralization within hybrid layers. Remineralization at different locations of the hybrid layers corresponded with quenching of fluorescence within similar locations of those hybrid layers. Remineralization was predominantly intrafibrillar in nature as interfibrillar spaces were filled with adhesive resin. Biomimetic remineralization of imperfect hybrid layers in primary human dentin is a potential means for preserving bond integrity. The success of the current proof-of-concept, laterally-diffusing remineralization protocol warrants development of a clinically-applicable biomimetic remineralization delivery system. PMID:19768792

  12. Double layer condenser as short-term storage for the Autarkic Hybrid; Doppelschicht-Kondensator als Kurzzeitspeicher fuer den Autarken Hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Egger, A.; Schmid, M.

    1999-07-01

    An array consisting of a double layer condensers and a suitable actuator forms the short-term storage of the Autarkic Hybrid. Experimental investigations are supposed to confirm the calculated conservation potentials. The operational strategy based on neuronal networks and the error-back-propagation algorithm allow a self optimising condenser control. (orig.) [German] Eine Anordnung aus Doppelschicht-Kondensatoren und einem geeigneten Stellglied bildet den Kurzzeitspeicher des Autarken Hybrid. Experimentelle Untersuchungen sollen die berechneten Einsparpotentiale bestaetigen. Die Betriebsstrategie auf Grundlage neuronaler Netze und der Error-Backpropagation-Algorithmus gestatten eine selbstoptimierende Kondensatorsteuerung. (orig.)

  13. A hybrid model for the computationally-efficient simulation of the cerebellar granular layer

    Directory of Open Access Journals (Sweden)

    Anna eCattani

    2016-04-01

    Full Text Available The aim of the present paper is to efficiently describe the membrane potential dynamics of neural populations formed by species having a high density difference in specific brain areas. We propose a hybrid model whose main ingredients are a conductance-based model (ODE system and its continuous counterpart (PDE system obtained through a limit process in which the number of neurons confined in a bounded region of the brain tissue is sent to infinity. Specifically, in the discrete model, each cell is described by a set of time-dependent variables, whereas in the continuum model, cells are grouped into populations that are described by a set of continuous variables.Communications between populations, which translate into interactions among the discrete and the continuous models, are the essence of the hybrid model we present here. The cerebellum and cerebellum-like structures show in their granular layer a large difference in the relative density of neuronal species making them a natural testing ground for our hybrid model. By reconstructing the ensemble activity of the cerebellar granular layer network and by comparing our results to a more realistic computational network, we demonstrate that our description of the network activity, even though it is not biophysically detailed, is still capable of reproducing salient features of neural network dynamics. Our modeling approach yields a significant computational cost reduction by increasing the simulation speed at least $270$ times. The hybrid model reproduces interesting dynamics such as local microcircuit synchronization, traveling waves, center-surround and time-windowing.

  14. HYBRID LAYER THICKNESS IN PRIMARY AND PERMANENT TEETH – A COMPARISON BETWEEN TOTAL ETCH ADHESIVES

    Directory of Open Access Journals (Sweden)

    Natalia Gateva

    2012-05-01

    Full Text Available Purpose: The aim this study is to compare the hybrid layer thickness and its micromorphological characteristics in samples from primary and permanent teeth following application of total etch adhesives.Materials and methods: On intact specimens of 20 primary and 10 permanent teeth was created flat dentin surfaces. The patterns were divided in 6 groups. Two different total etch adhesive systems were used – one tree steps (OptiBond, Kerr and one two steps (Exite, VivaDent. In groups 3, 4, 5 and 6 recommended etching time was used - 15 s, in groups 1 and 2 the etching time was reduced to 7 s. After applying the adhesive, resin composite build-ups were constructed. Thus restored samples are stored in saline solution for 24 hours at temperature 37 C. Then they are subjected to thermal stress in temperature between 5 C to 55 C for 1,500 cycles and to masticatory stress – 150,000 cycles with force 100 N in intervals of 0.4 s. After that the teeth are cut through the middle in medio-distal direction with a diamond disc. SEM observation was done to investigate the thickness of the hybrid layer and the presence of microgaps. Statistical analysis was performed with ANOVA and Tukey׳s tests.Results: SEM observation showed significant differences of the hybrid layer thickness between primary and permanent teeth under equal conditions and after different etching time. Group 6 presented the highest average thickness 8.85 μ and group 1 the lowest average in hybrid layer 3.74 μ.Conclusion: In primary teeth the hybrid layer thickness increases with the increased etching time. The hybrid layer thickness in primary teeth is greater than that of the hybrid layer in permanent teeth under equal conditions. For primary teeth it is more appropriate to reduce the etching time to 7s to obtain a hybrid layer with better quality

  15. High Efficiency Organic/Silicon-Nanowire Hybrid Solar Cells: Significance of Strong Inversion Layer

    Science.gov (United States)

    Yu, Xuegong; Shen, Xinlei; Mu, Xinhui; Zhang, Jie; Sun, Baoquan; Zeng, Lingsheng; Yang, Lifei; Wu, Yichao; He, Hang; Yang, Deren

    2015-11-01

    Organic/silicon nanowires (SiNWs) hybrid solar cells have recently been recognized as one of potentially low-cost candidates for photovoltaic application. Here, we have controllably prepared a series of uniform silicon nanowires (SiNWs) with various diameters on silicon substrate by metal-assisted chemical etching followed by thermal oxidization, and then fabricated the organic/SiNWs hybrid solar cells with poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS). It is found that the reflective index of SiNWs layer for sunlight depends on the filling ratio of SiNWs. Compared to the SiNWs with the lowest reflectivity (LR-SiNWs), the solar cell based on the SiNWs with low filling ratio (LF-SiNWs) has a higher open-circuit voltage and fill factor. The capacitance-voltage measurements have clarified that the built-in potential barrier at the LF-SiNWs/PEDOT:PSS interface is much larger than that at the LR-SiNWs/PEDOT one, which yields a strong inversion layer generating near the silicon surface. The formation of inversion layer can effectively suppress the carrier recombination, reducing the leakage current of solar cell, and meanwhile transfer the LF-SiNWs/PEDOT:PSS device into a p-n junction. As a result, a highest efficiency of 13.11% is achieved for the LF-SiNWs/PEDOT:PSS solar cell. These results pave a way to the fabrication of high efficiency organic/SiNWs hybrid solar cells.

  16. HyberLoc: Providing Physical Layer Location Privacy in Hybrid Sensor Networks

    CERN Document Server

    El-Badry, Rania; Youssef, Moustafa

    2010-01-01

    In many hybrid wireless sensor networks' applications, sensor nodes are deployed in hostile environments where trusted and un-trusted nodes co-exist. In anchor-based hybrid networks, it becomes important to allow trusted nodes to gain full access to the location information transmitted in beacon frames while, at the same time, prevent un-trusted nodes from using this information. The main challenge is that un-trusted nodes can measure the physical signal transmitted from anchor nodes, even if these nodes encrypt their transmission. Using the measured signal strength, un-trusted nodes can still tri-laterate the location of anchor nodes. In this paper, we propose HyberLoc, an algorithm that provides anchor physical layer location privacy in anchor-based hybrid sensor networks. The idea is for anchor nodes to dynamically change their transmission power following a certain probability distribution, degrading the localization accuracy at un-trusted nodes while maintaining high localization accuracy at trusted node...

  17. Thin hybrid pixel assembly with backside compensation layer on ROIC

    Science.gov (United States)

    Bates, R.; Buttar, C.; McMullen, T.; Cunningham, L.; Ashby, J.; Doherty, F.; Gray, C.; Pares, G.; Vignoud, L.; Kholti, B.; Vahanen, S.

    2017-01-01

    The entire ATLAS inner tracking system will be replaced for operation at the HL-LHC . This will include a significantly larger pixel detector of approximately 15 m2. For this project, it is critical to reduce the mass of the hybrid pixel modules and this requires thinning both the sensor and readout chips to about 150 micrometres each. The thinning of the silicon chips leads to low bump yield for SnAg bumps due to bad co-planarity of the two chips at the solder reflow stage creating dead zones within the pixel array. In the case of the ATLAS FEI4 pixel readout chip thinned to 100 micrometres, the chip is concave, with the front side in compression, with a bow of +100 micrometres at room temperature which varies to a bow of -175 micrometres at the SnAg solder reflow temperature, caused by the CTE mismatch between the materials in the CMOS stack and the silicon substrate. A new wafer level process to address the issue of low bump yield be controlling the chip bow has been developed. A back-side dielectric and metal stack of SiN and Al:Si has been deposited on the readout chip wafer to dynamically compensate the stress of the front side stack. In keeping with a 3D process the materials used are compatible with Through Silicon Via (TSV) technology with a TSV last approach which is under development for this chip. It is demonstrated that the amplitude of the correction can be manipulated by the deposition conditions and thickness of the SiN/Al:Si stack. The bow magnitude over the temperature range for the best sample to date is reduced by almost a factor of 4 and the sign of the bow (shape of the die) remains constant. Further development of the backside deposition conditions is on-going with the target of close to zero bow at the solder reflow temperature and a minimal bow magnitude throughout the temperature range. Assemblies produced from FEI4 readout wafers thinned to 100 micrometres with the backside compensation layer have been made for the first time and

  18. Layer-by-layer self-assembled active electrodes for hybrid photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Kniprath, Rolf

    2008-11-18

    Solar cells based on thin organic/inorganic heterofilms are currently in the focus of research, since they represent promising candidates for cost-efficient photovoltaic energy conversion. In this type of cells, charges are separated at a heterointerface between dissimilar electrode materials. These materials either absorb light themselves, or they are sensitized by an additional absorber layer at the interface. The present work investigates photovoltaic cells which are composed of nanoporous TiO{sub 2} combined with conjugated polymers and semiconductor quantum dots (QDs). The method of layer-by-layer self-assembly of oppositely charged nanoparticles and polymers is used for the fabrication of such devices. This method allows to fabricate nanoporous films with controlled thicknesses in the range of a few hundred nanometers to several micrometers. Investigations with scanning electron (SEM) and atomic force microscopy (AFM) reveal that the surface morphology of the films depends only on the chemical structure of the polyions used in the production process, and not on their molecular weight or conformation. From dye adsorption at the internal surface of the electrodes one can estimate that the internal surface area of a 1 {mu}m thick film is up to 120 times larger than the projection plane. X-ray photoelectron spectroscopy (XPS) is used to demonstrate that during the layer-by-layer self-assembly at least 40% of the TiO{sub 2} surface is covered with polymers. This feature allows to incorporate polythiophene derivatives into the films and to use them as sensitizers for TiO{sub 2}. Further, electrodes containing CdSe or CdTe quantum dots (QDs) as sensitizers are fabricated. For the fabrication of photovoltaic cells the layer-by-layer grown films are coated with an additional polymer layer, and Au back electrodes are evaporated on top. The cells are illuminated through transparent doped SnO{sub 2} front electrodes. The I/V curves of all fabricated cells show diode

  19. 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.

  20. SEM evaluation of the hybrid layer after cavity preparation with Er:YAG laser.

    Science.gov (United States)

    de Barceleiro, Marcos Oliveira; Dias, Kátia Regina Hostílio Cervantes; Sales, Helena Xavier; Silva, Bárbara Carvalho; Barceleiro, Cristiane Gomes

    2008-01-01

    This study compared the thickness of the hybrid layer formed using Scotchbond Multi-Purpose Plus, Single Bond 2, Prime & Bond 2.1 and Xeno III on a dentin surface prepared with a diamond bur in a high speed handpiece or prepared with an Er:YAG laser used with two parameters of pulse energy (200 and 400 mJ) and two parameters of frequency (4 and 6 Hz). Flat dentin surfaces obtained from 20 human third molars were treated with the two methods and were then prepared with the dentin adhesive systems according to the manufacturers' instructions. After a layer of composite was applied, the specimens were sectioned, flattened, polished and prepared for Scanning Electronic Microscopy observation. Five different measurements of the hybrid layer thickness were obtained along the bonded surface in each specimen. The results were statistically analyzed using Analysis of Variance and Student-Newman-Keuls tests (p cavity preparation method, four groups were formed: Group I (diamond bur) > Group II (Laser 200 mJ/4 Hz) = Group III (Laser 200 mJ/6 Hz) > Group IV (Laser 400 mJ/4 Hz) > Group V (Laser 400 mJ/6 Hz). When comparing the dentin adhesive systems, there were no statistically significant differences. These results showed that the four tested dentin adhesive systems produced a 2.90 +/- 1.71 microm hybrid layer in dentin prepared with a diamond bur. This hybrid layer was regular and routinely found. In the laser groups, the dentin adhesive systems produced hybrid layers ranging from 0.41 +/- 1.00 microm to 2.06 +/- 2.49 microm, which were very irregular and not routinely found. It was also concluded that the Er:YAG laser, with the parameters used in this experiment, has a negative influence on the formation of a hybrid layer and cavity preparation methods influence formation of the hybrid layer.

  1. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    Science.gov (United States)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-11-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

  2. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    Science.gov (United States)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-01-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

  3. Layer-by-layer assembly of multifunctional porous N-doped carbon nanotube hybrid architectures for flexible conductors and beyond.

    Science.gov (United States)

    Zhao, Songfang; Gao, Yongju; Li, Jinhui; Zhang, Guoping; Zhi, Chunyi; Deng, Libo; Sun, Rong; Wong, Ching-Ping

    2015-04-01

    Coassemble diverse functional nanomaterials with carbon nanotubes (CNTs) to form three-dimensional (3D) porous CNTs hybrid architectures (CHAs) are potentially desirable for applications in energy storage, flexible conductors, and catalysis, because of diverse functionalities and synergistic effects in the CHAs. Herein, we report a scalable strategy to incorporate various functional nanomaterials with N-doped CNTs (N-CNTs) into such 3D porous CHAs on the polyurethane (PU) sponge skeletons via layer-by-layer (LbL) assembly. To investigate their properties and applications, the specific CHAs based on N-CNTs and Ag nanoparticles (NPs), denoted as PU-(N-CNTs/Ag NPs)n, are developed. The unique binary structure enables these specific CHAs conductors to possess reliable mechanical and electrical performance under various elastic deformations as well as excellent hydrophilicity. Moreover, they are employed as strain-gauge sensor and heterogeneous catalyst, respectively. The sensor could detect continuous signal, static signal, and pulse signal with superior sustainability and reversibility, indicating an important branch of electromechanical devices. Furthermore, the synergistic effects among N-CNTs, Ag NPs, and porous structure endow the CHAs with excellent performance in catalysis. We have a great expectation that LbL assembly can afford a universal route for incorporating diverse functional materials into one structure.

  4. Direct electrochemistry of horseradish peroxidase immobilized on the layered calcium carbonate-gold nanoparticles inorganic hybrid composite.

    Science.gov (United States)

    Li, Feng; Feng, Yan; Wang, Zhen; Yang, Limin; Zhuo, Linhai; Tang, Bo

    2010-06-15

    A mediator-free hydrogen peroxide (H(2)O(2)) biosensor was fabricated based on immobilization of horseradish peroxidase (HRP) on layered calcium carbonate-gold nanoparticles (CaCO(3)-AuNPs) inorganic hybrid composite. The proposed biosensor showed a strong electrocatalytic activity toward the reduction of H(2)O(2), which could be attributed to the favored orientation of HRP in the well-confined surface as well as the high electrical conductivity of the resulting CaCO(3)-AuNPs inorganic hybrid composite. The hybrid composite was obtained by the adsorption of AuNPs onto the surfaces of layered CaCO(3) through electrostatic interaction. The key analytical parameters relative to the biosensor performance such as pH and applied potential were optimized. The developed biosensor also exhibited a fast amperometric response (3s), a good linear response toward H(2)O(2) over a wide range of concentration from 5.0x10(-7) to 5.2x10(-3)M, and a low detection limit of 1.0x10(-7)M. The facile, inexpensive and reliable sensing platform based on layered CaCO(3)-AuNPs inorganic hybrid composite should hold a huge potential for the fabrication of more other biosensors.

  5. Optimal design of damping layers in SMA/GFRP laminated hybrid composites

    Science.gov (United States)

    Haghdoust, P.; Cinquemani, S.; Lo Conte, A.; Lecis, N.

    2017-10-01

    This work describes the optimization of the shape profiles for shape memory alloys (SMA) sheets in hybrid layered composite structures, i.e. slender beams or thinner plates, designed for the passive attenuation of flexural vibrations. The paper starts with the description of the material and architecture of the investigated hybrid layered composite. An analytical method, for evaluating the energy dissipation inside a vibrating cantilever beam is developed. The analytical solution is then followed by a shape profile optimization of the inserts, using a genetic algorithm to minimize the SMA material layer usage, while maintaining target level of structural damping. Delamination problem at SMA/glass fiber reinforced polymer interface is discussed. At the end, the proposed methodology has been applied to study the hybridization of a wind turbine layered structure blade with SMA material, in order to increase its passive damping.

  6. Weather forecasting based on hybrid neural model

    Science.gov (United States)

    Saba, Tanzila; Rehman, Amjad; AlGhamdi, Jarallah S.

    2017-02-01

    Making deductions and expectations about climate has been a challenge all through mankind's history. Challenges with exact meteorological directions assist to foresee and handle problems well in time. Different strategies have been investigated using various machine learning techniques in reported forecasting systems. Current research investigates climate as a major challenge for machine information mining and deduction. Accordingly, this paper presents a hybrid neural model (MLP and RBF) to enhance the accuracy of weather forecasting. Proposed hybrid model ensure precise forecasting due to the specialty of climate anticipating frameworks. The study concentrates on the data representing Saudi Arabia weather forecasting. The main input features employed to train individual and hybrid neural networks that include average dew point, minimum temperature, maximum temperature, mean temperature, average relative moistness, precipitation, normal wind speed, high wind speed and average cloudiness. The output layer composed of two neurons to represent rainy and dry weathers. Moreover, trial and error approach is adopted to select an appropriate number of inputs to the hybrid neural network. Correlation coefficient, RMSE and scatter index are the standard yard sticks adopted for forecast accuracy measurement. On individual standing MLP forecasting results are better than RBF, however, the proposed simplified hybrid neural model comes out with better forecasting accuracy as compared to both individual networks. Additionally, results are better than reported in the state of art, using a simple neural structure that reduces training time and complexity.

  7. Interaction of Atmospheric Turbulence with Blade Boundary Layer Dynamics on a 5MW Wind Turbine using Blade-Boundary-Layer-Resolved CFD with hybrid URANS-LES.

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, Ganesh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pennsylvania State Univ., University Park, PA (United States); Brasseur, James [Pennsylvania State Univ., University Park, PA (United States); Univ. of Colorado, Boulder, CO (United States); Lavely, Adam; Jayaraman, Balaji; Craven, Brent

    2016-01-04

    We describe the response of the NREL 5 MW wind turbine blade boundary layer to the passage of atmospheric turbulence using blade-boundary-layer-resolved computational fluid dynamics with hybrid URANS-LES modeling.

  8. Organic layers on silicon result in a unique hybrid fet

    NARCIS (Netherlands)

    Faber, E.J.; Albers, M.; Smet, de L.C.P.M.; Olthuis, W.; Zuilhof, H.; Sudholter, E.J.R.; Bergveld, P.; Berg, van den A.

    2008-01-01

    A Field-Effect Transistor (FET) is presented that combines the conventional lay-out of the silicon substrate (channel and source and drain connections) with a Si-C linked organic gate insulator contacted via an organic, conducting polymer. It is shown that this hybrid device combines the excellent e

  9. Highly Anisotropic Thermal Conductivity of Layer-by-Layer Assembled Nanofibrillated Cellulose/Graphene Nanosheets Hybrid Films for Thermal Management.

    Science.gov (United States)

    Song, Na; Jiao, Dejin; Cui, Siqi; Hou, Xingshuang; Ding, Peng; Shi, Liyi

    2017-01-25

    An anisotropic thermally conductive film with tailorable microstructures and macroproperties is fabricated using a layer-by-layer (LbL) assembly of graphene oxide (GO) and nanofibrillated cellulose (NFC) on a flexible NFC substrate driven by hydrogen bonding interactions, followed by chemical reduction process. The resulting NFC/reduced graphene oxide (RGO) hybrid film reveals an orderly hierarchical structure in which the RGO nanosheets exhibit a high degree of orientation along the in-plane direction. The assembly cycles dramatically increase the in-plane thermal conductivity (λX) of the hybrid film to 12.6 W·m(-1)·K(-1), while the cross-plane thermal conductivity (λZ) shows a lower value of 0.042 W·m(-1)·K(-1) in the hybrid film with 40 assembly cycles. The thermal conductivity anisotropy reaches up to λX/λZ = 279, which is substantially larger than that of similar polymeric nanocomposites, indicating that the LbL assembly on a flexible NFC substrate is an efficient technique for the preparation of polymeric nanocomposites with improved heat conducting property. Moreover, the layered hybrid film composed of 1D NFC and 2D RGO exhibits synergetic mechnical properties with outstanding flexibility and a high tensile strength (107 MPa). The combination of anisotropic thermal conductivity and superior mechanical performance may facilitate the applications in thermal management.

  10. Cross-Linkable and Dual Functional Hybrid Polymeric Electron Transporting Layer for High-Performance Inverted Polymer Solar Cells.

    Science.gov (United States)

    Dong, Sheng; Hu, Zhicheng; Zhang, Kai; Yin, Qingwu; Jiang, Xiaofang; Huang, Fei; Cao, Yong

    2017-06-20

    A cross-linkable dual functional polymer hybrid electron transport layer (ETL) is developed by simply adding an amino-functionalized polymer dopant (PN4N) and a light crosslinker into a commercialized n-type semiconductor (N2200) matrix. It is found that the resulting hybrid ETL not only has a good solvent resistance, facilitating multilayers device fabrication but also exhibits much improved electron transporting/extraction properties due to the doping between PN4N and N2200. As a result, by using PTB7-Th:PC71 BM blend as an active layer, the inverted device based on the hybrid ETL can yield a prominent power conversion efficiency of around 10.07%. More interestingly, photovoltaic property studies of bilayer devices suggest that the absorption of the hybrid ETL contributes to photocurrent and hence the hybrid ETL simultaneously acts as both cathode interlayer material and an electron acceptor. The resulting inverted polymer solar cells function like a novel device architectures with a combination of a bulk heterojunction device and miniature bilayer devices. This work provides new insights on function of ETLs and may be open up a new direction for the design of new ETL materials and novel device architectures to further improve device performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Hybrid polymer networks as ultra low `k` dielectric layers

    Energy Technology Data Exchange (ETDEWEB)

    Lewicki, James; Worsley, Marcus A.

    2016-02-16

    According to one embodiment, a polymeric material includes at least one polydimethylsiloxane (PDMS) polymer, and at least one polyhedral oligomericsilsequioxane (POSS) molecule. According to another embodiment, a method includes providing at least one polydimethylsiloxane (PDMS) polymer, providing at least one polyhedral oligomericsilsequioxane (POSS) molecule, and coupling the at least one PDSM polymer to the at least one POSS molecule to form a hybrid polymeric material.

  12. A comparative study on the performance of hybrid solar cells containing ZnSTe QDs in hole transporting layer and photoactive layer

    Science.gov (United States)

    Najeeb, Mansoor Ani; Abdullah, Shahino Mah; Aziz, Fakhra; Ahmad, Zubair; Shakoor, R. A.; Mohamed, A. M. A.; Khalil, Uzma; Swelm, Wageh; Al-Ghamdi, Ahmed A.; Sulaiman, Khaulah

    2016-12-01

    In this paper, ZnSTe quantum dots-based hybrid solar cells (HSC) with two different device architectures have been investigated. The improved performance of the poly(3-hexylthiophene) (P3HT) and [6,6]phenyl C71 butyric acid methyl ester (PC71BM)-based bulk heterojunction (BHJ) solar cells by the incorporation of ZnSTe quantum dots (QDs) with an average size of 2.96 nm in PEDOT:PSS layer and active layer that have been demonstrated. Although the efficiency of both types of devices is almost the same, a close comparison reveals different reasons behind their improved performance. The device prepared with QDs in the HTL has shown reduced series resistance, increased shunt resistance, and improved mobility. On the other hand, QDs in the photoactive layer demonstrates increased photo-generation leading to improved efficiency.

  13. Layered hybrid perovskites with micropores created by alkylammonium functional silsesquioxane interlayers.

    Science.gov (United States)

    Kataoka, Sho; Banerjee, Subhabrata; Kawai, Akiko; Kamimura, Yoshihiro; Choi, Jun-Chul; Kodaira, Tetsuya; Sato, Kazuhiko; Endo, Akira

    2015-04-01

    Layered organic-inorganic hybrid perovskites that consist of metal halides and organic interlayers are a class of low-dimensional materials. Here, we report the fabrication of layered hybrid perovskites using metal halides and silsesquioxane with a cage-like structure. We used a silsesquioxane as an interlayer to produce a rigid structure and improve the functionality of perovskite layers. Propylammonium-functionalized silsesquioxane and metal halide salts (CuCl2, PdCl2, PbCl2, and MnCl2) were self-assembled to form rigid layered perovskite structures with high crystallinity. The rigid silsesquioxane structure produces micropores between the perovskite layers that can potentially be filled with different molecules to tune the dielectric constants of the interlayers. The obtained silsesquioxane-metal halide hybrid perovskites exhibit some characteristic properties of layered perovskites including magnetic ordering (CuCl4(2-) and MnCl4(2-)) and excitonic absorption/emission (PbCl4(2-)). Our results indicate that inserting silsesquioxane interlayers into hybrid perovskites retains and enhances the low-dimensional properties of the materials.

  14. Hybrid Doping of Few-Layer Graphene via a Combination of Intercalation and Surface Doping

    KAUST Repository

    Mansour, Ahmed

    2017-05-23

    Surface molecular doping of graphene has been shown to modify its work function and increase its conductivity. However, the associated shifts in work function and increases in carrier concentration are highly coupled and limited by the surface coverage of dopant molecules on graphene. Here we show that few-layer graphene (FLG) can be doped using a hybrid approach, effectively combining surface doping by larger (metal-)organic molecules, while smaller molecules, such as Br2 and FeCl3, intercalate into the bulk. Intercalation tunes the carrier concentration more effectively, whereas surface doping of intercalated FLG can be used to tune its work function without reducing the carrier mobility. This multi-modal doping approach yields a very high carrier density and tunable work function for FLG, demonstrating a new versatile platform for fabricating graphene-based contacts for electronic, optoelectronic and photovoltaic applications.

  15. Optimizing dentin bond durability: strategies to prevent hydrolytic degradation of the hybrid layer

    Science.gov (United States)

    Tjäderhane, Leo; Nascimento, Fabio D.; Breschi, Lorenzo; Mazzoni, Annalisa; Tersariol, Ivarne L.S.; Geraldeli, Saulo; Tezvergil-Mutluay, Arzu; Carrilho, Marcela; Carvalho, Ricardo M.; Tay, Franklin R.; Pashley, David H.

    2014-01-01

    Objectives Endogenous dentin collagenolytic enzymes, matrix metalloproteinases (MMPs) and cysteine cathepsins, are responsible for the time-related hydrolysis of collagen matrix of the hybrid layers. As the integrity of the collagen matrix is essential for the preservation of long-term dentin bond strength, inhibition or inactivation of endogenous dentin proteases is necessary for durable resin-bonded composite resin restorations. Methods Dentin contains collagenolytic enzymes, matrix metalloproteinases (MMPs) and cysteine cathepsins, which are responsible for the hydrolytic degradation of collagen matrix in the bonded interface. Several tentative approaches to prevent enzyme function either directly or indirectly have been proposed in the literature. Results Chlorhexidine, a general inhibitor of both MMPs and cysteine cathepsins, applied before primer/adhesive application is the most tested method. In general, these experiments have shown that enzyme inhibition is a promising scheme to improve hybrid layer preservation and bond strength durability. Other enzyme inhibitors, e.g. enzyme-inhibiting monomers and antimicrobial compounds, may be considered promising alternatives that would allow more simple clinical application than chlorhexidine. Cross-linking collagen and/or dentin organic matrix-bound enzymes could render hybrid layer organic matrix resistant to degradation, and complete removal of water from the hybrid layer with ethanol wet bonding or biomimetic remineralization should eliminate hydrolysis of both collagen and resin components. Significance Identification of the enzymes responsible for the hydrolysis of hybrid layer collagen and understanding their function has prompted several innovative approaches to retain the hybrid layer integrity and strong dentin bonding. The ultimate goal, prevention of collagen matrix degradation with techniques and commercially available materials that are simple and effective in clinical settings may be achievable in

  16. Effects of buffer layer and thermal annealing on the performance of hybrid Cu2S/PVK electrically bistable devices

    Science.gov (United States)

    Li, Xu; Lu, Yue; Guan, Li; Li, Jiantao; Wang, Yichao; Dong, Guoyi; Tang, Aiwei; Teng, Feng

    2016-09-01

    Hybrid organic/inorganic electrically bistable devices (EBDs) based on Cu2S/PVK nanocomposites have been fabricated by using a simple spin-coating method. An obvious electrical bistability is observed in the current-voltage (I-V) characteristics of the devices, and the presence of the buffer layer and the annealing process have an important effect on the enhancement of the ON/OFF current ratios. Different electrical conduction mechanisms are responsible for the charge switching of the devices in the presence and absence of the buffer layer.

  17. Collaborative-Hybrid Multi-Layer Network Control for Emerging Cyber-Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, Tom [USC; Ghani, Nasir [UNM; Boyd, Eric [UCAID

    2010-08-31

    At a high level, there were four basic task areas identified for the Hybrid-MLN project. They are: o Multi-Layer, Multi-Domain, Control Plane Architecture and Implementation, including OSCARS layer2 and InterDomain Adaptation, Integration of LambdaStation and Terapaths with Layer2 dynamic provisioning, Control plane software release, Scheduling, AAA, security architecture, Network Virtualization architecture, Multi-Layer Network Architecture Framework Definition; o Heterogeneous DataPlane Testing; o Simulation; o Project Publications, Reports, and Presentations.

  18. Damping characteristics of active-passive hybrid constrained-layer treated beam structures

    Science.gov (United States)

    Liu, Yanning; Wang, Kon-Well

    2000-04-01

    A new configuration of surface damping treatments, Active- Passive Hybrid Constrained Layer (HCL) damping, is analyzed and experimentally investigated. The purpose is to improve the performance of the current active constrained layer (ACL) and passive constrained layer (PCL) treatments by mixing passive and active materials in the constraining layer. In HCL, the viscoelastic material is constrained by an active-passive hybrid constraining layer -- the active part is made of PZT ceramics, and the passive part can be selected by the designer to meet different requirements, such as higher damping performance or lighter weight. The active and passive constraining parts are mechanically connected such that the displacement and force are continuous at the connecting surface, but are isolated electrically so the passive constraining part will not affect the function of its active counterpart. Following a generic study of the HCL concept by the authors earlier, the purpose of this paper is to illustrate and validate the HCL performance through both numerical and experimental investigations on a beam structure. The governing equations and boundary conditions of an HCL treated beam are derived and a finite element model is formulated. Tabletop tests with cantilever beam specimens are used for the experimental study. The new hybrid constrained layer is found to have the advantages of both ACL and PCL. By selecting a stiffer passive constraining material and an optimal active-to-passive length ratio, the HCL can achieve better closed-loop and open-loop performances than the treatment with a pure active constraining layer.

  19. Self-referenced refractive index sensing with hybrid-Tamm-plasmon-polariton modes in sub-wavelength analyte layers

    Science.gov (United States)

    Kumar, Samir; Shukla, Mukesh Kumar; Sona Maji, Partha; Das, Ritwick

    2017-09-01

    A coupled Tamm-plasmon-polariton (TPP) hybrid-mode based self-referenced refractive-index sensor is proposed. The geometry is comprised of a sub-wavelength analyte (sensing) layer sandwiched between two metal-clad distributed-Bragg-reflectors (DBRs). Reflection spectrum of the geometry exhibits two discernible reflectivity minima within the photonic-bandgap of DBR. The reflectivity minima are essentially due to excitation of two hybrid modes which have symmetric and anti-symmetric field distribution about the center resulting in an anti-crossing behaviour exhibited by hybrid-TPP mode dispersion curves. The low frequency symmetric mode exhibits strong dispersive properties by virtue of significant presence of mode-field in sensing medium. On the other hand, the high-frequency anti-symmetric mode remains unchanged with alterations in sensing layer. Thus, we propose a self-referenced sensing scheme using hybrid-TPP modes with sensitivity varying from 65~nm~RIU-1 to 180~nm~RIU-1 in the visible band. In addition, the TPP resonance are appreciably sharp as compared to surface-plasmon based geometries which results in improved detection accuracy and figure of merit. We also present an analysis for optimizing the sensor design for enhancing the sensitivity as well as detection accuracy.

  20. Hybrid Layered Crystal Comprising Polyoxometalate and Surfactant Synthesized from Reduced Mo-Blue Species

    Directory of Open Access Journals (Sweden)

    Keisuke Mikurube

    2013-01-01

    Full Text Available A hybrid layered crystal containing polyoxomolybdate was successfully synthesized from reduced Mo-blue species as starting material. The hybrid crystal, [C5H5N(C16H33]2[β-H2Mo8O26]·2C2H5OH (C16py-H2Mo8, was obtained as a single phase by the gradual oxidation of hexadecylpyridinium-Mo-blue (C16py-Mo-blue hybrid. The X-ray structure analysis revealed that C16py-H2Mo8 comprised β-type octamolybdate anion with two protons (β-H2Mo8. The β-H2Mo8 anions and ethanol molecules of crystallization formed two-dimensional anionic layers. The pyridine rings of C16py did not attend to form the two-dimensional inorganic layers, and the interdigitated C16py bilayers were sandwiched by the β-H2Mo8 anionic layers with periodicity of 18.2 Å. These C16py-H2Mo8 hybrid layered crystals possibly work as a new class of proton conductor.

  1. SCAN-based hybrid and double-hybrid density functionals from models without fitted parameters

    OpenAIRE

    Hui, Kerwin; Chai, Jeng-Da

    2015-01-01

    By incorporating the nonempirical SCAN semilocal density functional [Sun, Ruzsinszky, and Perdew, Phys. Rev. Lett. 115, 036402 (2015)] in the underlying expression of four existing hybrid and double-hybrid models, we propose one hybrid (SCAN0) and three double-hybrid (SCAN0-DH, SCAN-QIDH, and SCAN0-2) density functionals, which are free from any fitted parameters. The SCAN-based double-hybrid functionals consistently outperform their parent SCAN semilocal functional for self-interaction probl...

  2. Analysis of physical layer performance of hybrid optical-wireless access network

    Science.gov (United States)

    Shaddad, R. Q.; Mohammad, A. B.; Al-hetar, A. M.

    2011-09-01

    The hybrid optical-wireless access network (HOWAN) is a favorable architecture for next generation access network. It is an optimal combination of an optical backhaul and a wireless front-end for an efficient access network. In this paper, the HOWAN architecture is designed based on a wavelengths division multiplexing/time division multiplexing passive optical network (WDM/TDM PON) at the optical backhaul and a wireless fidelity (WiFi) technology at the wireless front-end. The HOWAN is proposed that can provide blanket coverage of broadband and flexible connection for end-users. Most of the existing works, based on performance evaluation are concerned on network layer aspects. This paper reports physical layer performance in terms of the bit error rate (BER), eye diagram, and signal-to-noise ratio (SNR) of the communication system. It accommodates 8 wavelength channels with 32 optical network unit/wireless access points (ONU/APs). It is demonstrated that downstream and upstream of 2 Gb/s can be achieved by optical backhaul for each wavelength channel along optical fiber length of 20 km and a data rate of 54 Mb/s per ONU/AP along a 50 m outdoor wireless link.

  3. A Hybrid Constructive Algorithm for Single-Layer Feedforward Networks Learning.

    Science.gov (United States)

    Wu, Xing; Rózycki, Paweł; Wilamowski, Bogdan M

    2015-08-01

    Single-layer feedforward networks (SLFNs) have been proven to be a universal approximator when all the parameters are allowed to be adjustable. It is widely used in classification and regression problems. The SLFN learning involves two tasks: determining network size and training the parameters. Most current algorithms could not be satisfactory to both sides. Some algorithms focused on construction and only tuned part of the parameters, which may not be able to achieve a compact network. Other gradient-based optimization algorithms focused on parameters tuning while the network size has to be preset by the user. Therefore, trial-and-error approach has to be used to search the optimal network size. Because results of each trial cannot be reused in another trial, it costs much computation. In this paper, a hybrid constructive (HC)algorithm is proposed for SLFN learning, which can train all the parameters and determine the network size simultaneously. At first, by combining Levenberg-Marquardt algorithm and least-square method, a hybrid algorithm is presented for training SLFN with fixed network size. Then,with the hybrid algorithm, an incremental constructive scheme is proposed. A new randomly initialized neuron is added each time when the training entrapped into local minima. Because the training continued on previous results after adding new neurons, the proposed HC algorithm works efficiently. Several practical problems were given for comparison with other popular algorithms. The experimental results demonstrated that the HC algorithm worked more efficiently than those optimization methods with trial and error, and could achieve much more compact SLFN than those construction algorithms.

  4. Surface chemistry for molecular layer deposition of organic and hybrid organic-inorganic polymers.

    Science.gov (United States)

    George, Steven M; Yoon, Byunghoon; Dameron, Arrelaine A

    2009-04-21

    The fabrication of many devices in modern technology requires techniques for growing thin films. As devices miniaturize, manufacturers will need to control thin film growth at the atomic level. Because many devices have challenging morphologies, thin films must be able to coat conformally on structures with high aspect ratios. Techniques based on atomic layer deposition (ALD), a special type of chemical vapor deposition, allow for the growth of ultra-thin and conformal films of inorganic materials using sequential, self-limiting reactions. Molecular layer deposition (MLD) methods extend this strategy to include organic and hybrid organic-inorganic polymeric materials. In this Account, we provide an overview of the surface chemistry for the MLD of organic and hybrid organic-inorganic polymers and examine a variety of surface chemistry strategies for growing polymer thin films. Previously, surface chemistry for the MLD of organic polymers such as polyamides and polyimides has used two-step AB reaction cycles using homo-bifunctional reactants. However, these reagents can react twice and eliminate active sites on the growing polymer surface. To avoid this problem, we can employ alternative precursors for MLD based on hetero-bifunctional reactants and ring-opening reactions. We can also use surface activation or protected chemical functional groups. In addition, we can combine the reactants for ALD and MLD to grow hybrid organic-inorganic polymers that should display interesting properties. For example, using trimethylaluminum (TMA) and various diols as reactants, we can achieve the MLD of alucone organic-inorganic polymers. We can alter the chemical and physical properties of these organic-inorganic polymers by varying the organic constituent in the diol or blending the alucone MLD films with purely inorganic ALD films to build a nanocomposite or nanolaminate. The combination of ALD and MLD reactants enlarges the number of possible sequential self-limiting surface

  5. Improved performances of AlN/polyimide hybrid film and its application in redistribution layer

    Science.gov (United States)

    Liu, Zhe; Ding, Guifu; Luo, Jiangbo; Lu, Wen; Zhao, Xiaolin; Cheng, Ping; Wang, Yanlei

    2016-09-01

    The AlN/polyimide (PI) hybrid film was studied as the dielectric layer in the redistribution layer (RDL) in this work. The incorporation of the AlN into the PI matrix was achieved by mechanical ball-milling process. The spin-coating process was used to fabricate the AlN/PI hybrid film, which is compatible with micro-electro-mechanical system (MEMS) technology for fabricating RDL. The AlN/PI hybrid film was characterized by Fourier transform infrared (FTIR) spectrum and thermogravimetric analysis (TGA). The effect of the AlN content on the thermal stability, thermal expansion coefficient, hardness and water adsorption of the AlN/PI hybrid film was studied. The results indicated that the addition of AlN nanoparticles improved the thermal stability and hardness, but decreased the thermal expansion coefficient and water absorption of the pure PI film. As an example of its typical application, the AlN/PI hybrid film with 8 wt.% AlN was patterned using micromachining technology and used as the dielectric layer in RDL successfully.

  6. Perovskite-Like Organic-Inorganic Hybrid Lead Iodide with a Large Organic Cation Incorporated within the Layers.

    Science.gov (United States)

    Que, Chen-Jie; Mo, Chong-Jiao; Li, Zhao-Qi; Zhang, Guang-Lin; Zhu, Qin-Yu; Dai, Jie

    2017-03-06

    A great effort has been made to investigate 2D perovskites to improve the stability and controllability in the fabrication of photoelectronic devices. As far as we know, only small organic cations such as methylammonium can incorporate into the multilayered perovskite structure except the cations sandwiched between the inorganic layers. We report here a new layered lead iodide, (H2Aepz)3Pb4I14 (1), where larger organic cations, bis-protonated 2-(2-aminoethyl)pyrazole (Aepz), not only were sandwiched between the inorganic layers but also were incorporated within the perovskite-like PbI layered structure. Another 2D compound, (H2Aepz)PbI4 (2), was also prepared that was a one-layer perovskite. A simple Schottky device was prepared to investigate the photoelectroresponsive properties of the compounds in comparison with that of a typical organic-inorganic hybrid perovskite. In general, the energy gap is decreased with an increase in the perovskite layers, but the band gap of two-layered 1 is larger than that of one-layered 2. The photocurrent densities of the compounds are in the order of 1 < 2 < (CH3NH3)PbI3, which is discussed based on the crystal structures and band energy gaps.

  7. Engineering New Layered Solids from Exfoliated Inorganics: a Periodically Alternating Hydrotalcite - Montmorillonite Layered Hybrid

    Science.gov (United States)

    Chalasani, Rajesh; Gupta, Amit; Vasudevan, Sukumaran

    2013-12-01

    Two-dimensional (2D) nanosheets obtained by exfoliating inorganic layered crystals have emerged as a new class of materials with unique attributes. One of the critical challenges is to develop robust and versatile methods for creating new nanostructures from these 2D-nanosheets. Here we report the delamination of layered materials that belonging to two different classes - the cationic clay, montmorillonite, and the anionic clay, hydrotalcite - by intercalation of appropriate ionic surfactants followed by dispersion in a non-polar solvent. The solids are delaminated to single layers of atomic thickness with the ionic surfactants remaining tethered to the inorganic and consequently the nanosheets are electrically neutral. We then show that when dispersions of the two solids are mixed the exfoliated sheets self-assemble as a new layered solid with periodically alternating hydrotalcite and montmorillonite layers. The procedure outlined here is easily extended to other layered solids for creating new superstructures from 2D-nanosheets by self-assembly.

  8. Research progress on optimization of device structure and components of light-absorption layer in hybrid perovskite based heterojunction solar cells%杂化钙钛矿太阳能电池结构及光吸收层组成优化研究进展

    Institute of Scientific and Technical Information of China (English)

    孔梦琴; 万丽; 李琴; 胡航; 张秋萍; 王世敏

    2015-01-01

    近年来,有机-无机杂化钙钛矿基异质结太阳能电池发展十分迅速,目前最高光电转换效率已突破20%。本文简要概述了杂化钙钛矿基太阳能电池的结构、原理以及常见的杂化钙钛矿薄膜的制备方法,详细总结了近年来器件结构和杂化钙钛矿材料不断优化的成果和相关研究进展,重点阐述了器件的结构和组成对杂化钙钛矿基太阳能电池光电转换效率的影响,并对有机-无机杂化钙钛矿基太阳能电池未来的研究前景进行了展望。%In recent years, the development of organic-inorganic hybrid perovskite solar cells is very rapid, of which the highest efficiency has exceeded 20%. This article briefly intruduces the structures and the mechanism of the hybrid perovskite based solar cells and the fabrication methods of hybrid peroskite thin films, then summarizes recent research progress of structure and components optimization of light-absorption layer in hybrid perovskite based solar cells. Moreover, the impact of the device structure and composition on the photoelectric conversion efficiency of solar cells are discussed. Additionally, the future research prospects about organic-inorganic hybrid perovskite-based solar cells are presented.

  9. Improving efficiency by hybrid TiO(2) nanorods with 1,10-phenanthroline as a cathode buffer layer for inverted organic solar cells.

    Science.gov (United States)

    Sun, Chunming; Wu, Yulei; Zhang, Wenjun; Jiang, Nianquan; Jiu, Tonggang; Fang, Junfeng

    2014-01-22

    We reported a significant improvement in the efficiency of organic solar cells by introducing hybrid TiO2:1,10-phenanthroline as a cathode buffer layer. The devices based on polymer thieno[3,4-b]thiophene/benzodithiophene:[6,6]-phenyl C71-butyric acid methyl ester (PTB7:PC71BM) with hybrid buffer layer exhibited an average power conversion efficiency (PCE) as high as 8.02%, accounting for 20.8% enhancement compared with the TiO2 based devices. The cathode modification function of this hybrid material could also be extended to the poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PC61BM) system. We anticipate that this study will stimulate further research on hybrid materials to achieve more efficient charge collection and device performance.

  10. Hybrid Multi-Layer Network Control for Emerging Cyber-Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Summerhill, Richard

    2009-08-14

    There were four basic task areas identified for the Hybrid-MLN project. They are: o Multi-Layer, Multi-Domain, Control Plane Architecture and Implementation, o Heterogeneous DataPlane Testing, o Simulation, o Project Publications, Reports, and Presentations.

  11. Evaluation of matrix metalloproteinase and cysteine cathepsin activity in dentin hybrid layer by gelatin zymography

    Directory of Open Access Journals (Sweden)

    Sekar Mahalaxmi

    2016-01-01

    Conclusion: Etch and rinse adhesive activated MMPs and CCs within the hybrid layer that remained active till 7th day and no gelatinolytic activity was found on 21st day and MMPs are more active compared to CCs and MMP-2.

  12. Microcapsule production by an hybrid colloidosome-layer-by-layer technique

    NARCIS (Netherlands)

    Rossier Miranda, F.J.; Schroën, C.G.P.H.; Boom, R.M.

    2012-01-01

    Although many different methods for microencapsulation are known only some of them had been applied at industrial scale, due to complexity, lack of mechanical strength of the resulting capsules, and the costs related to their production. One of such methods is the electrostatic layer-by-layer (LbL)

  13. Optimization of hybrid token-CDMA MAC system using cross-layer information

    CSIR Research Space (South Africa)

    Liu, I-S

    2007-08-01

    Full Text Available connected to the dynamics of the PHY layer, and the cross-layer interactions at each node Optimization of Hybrid Token-CDMA MAC System Using Cross-Layer Information I-Sheng Liu, Graduate Student Member, IEEE, Fambirai Takawira, Member, IEEE, and Hong... the Institute of Telecontrol and Telemeasure in Shi Jian Zhuang, 1989, and the PhD degree from the Beijing University of Aerinautics and Astronautics in Beijing, 1995. His research interests are in the area of digital and wireless communications and digital...

  14. Solid-state NMR characterization of the structure and thermal stability of hybrid organic-inorganic compounds based on a HLaNb2O7 Dion-Jacobson layered perovskite.

    Science.gov (United States)

    Cattaneo, Alice S; Ferrara, Chiara; Marculescu, Adriana Mossuto; Giannici, Francesco; Martorana, Antonino; Mustarelli, Piercarlo; Tealdi, Cristina

    2016-08-03

    Dion-Jacobson phases, like MLaNb2O7, are an interesting class of ion-exchangeable layered perovskites possessing electronic and photocatalytic properties. Their protonated and organo-modified homologues, in particular, have already been indicated as promising catalysts. However, the structural analysis of these highly tailorable materials is still incomplete, and both the intercalation process and thermal stability of the included organic moieties are far from being completely understood. In this study, we present a thorough solid-state NMR characterization of HLaNb2O7·xH2O intercalated with different amounts of octylamine, or with decylamine. Samples were analyzed as prepared, and after thermal treatment at different temperatures up to 220 °C. The substitution of pristine proton ions was followed via(1)H MAS NMR spectroscopy, whereas the alkyl chains were monitored through (13)C((1)H) CP MAS experiments. The interactions in the interlayer space were explored using (13)C((1)H) 2D heteronuclear correlation experiments. We demonstrate that some of the protons are involved in the functionalization reaction, and some of them are in close proximity to the alkyl ammonium chains. Heating of the hybrid materials leads first to a rearrangement of the alkyl chains and then to their degradation. The spatial arrangement of the chains, their interactions and the thermal behavior of the materials depend on the extent of the functionalization, and on the nature of the intercalated alkyl ammonium ions.

  15. Solution-processed MoO3:PEDOT:PSS hybrid hole transporting layer for inverted polymer solar cells.

    Science.gov (United States)

    Wang, Yiling; Luo, Qun; Wu, Na; Wang, Qiankun; Zhu, Hongfei; Chen, Liwei; Li, Yan-Qing; Luo, Liqiang; Ma, Chang-Qi

    2015-04-08

    Solution-processed organic-inorganic hybrids composing of MoO3 nanoparticles and PEDOT:PSS were developed for use in inverted organic solar cells as hole transporting layer (HTL). The hybrid MoO3:PEDOT:PSS inks were prepared by simply mixing PEDOT:PSS aqueous and MoO3 ethanol suspension together. A core-shell structure was proposed in the MoO3:PEDOT:PSS hybrid ink, where PEDOT chains act as the core and MoO3 nanoparticles connected with PSS chains act as the composite shell. The mixing with PEDOT:PSS suppressed the aggregation of MoO3 nanoparticles, which led to a smoother surface. In addition, since the hydrophilic PSS chains were passivated through preferentially connection with MoO3, the stronger adhesion between MoO3 nanoparticles and the photoactive layer improved the film forming ability of the MoO3:PEDOT:PSS hybrid ink. The MoO3:PEDOT:PSS hybrid HTL can therefore be feasibly deposited onto the hydrophobic photoactive polymer layer without any surface treatment. The use of the MoO3:PEDOT:PSS hybrid HTL resulted in the optimized P3HT:PC61BM- and PTB7:PC61BM-based inverted organic solar cells reaching highest power conversion efficiencies of 3.29% and 5.92%, respectively, which were comparable with that of the control devices using thermally evaporated MoO3 HTL (3.05% and 6.01%, respectively). Furthermore, less HTL thickness dependence of device performance was found for the hybrid HTL-based devices, which makes it more compatible with roll-to-roll printing process. In the end, influence of the blend ratio of MoO3 to PEDOT:PSS on photovoltaic performance and device stability was studied carefully, results indicated that the device performance would decrease with the increase of MoO3 blended ratio, whereas the long-term stability was improved.

  16. Chlorine adlayer-templated growth of a hybrid inorganic-organic layered structure on Au(111)

    Science.gov (United States)

    Rzeźnicka, I. I.; Horino, H.; Yagyu, K.; Suzuki, T.; Kajimoto, S.; Fukumura, H.

    2016-10-01

    Growth of a hybrid inorganic-organic layered structure on the Au(111) surface using a one-step solution growth is reported. The hybrid structure is consist of 4,4‧-bipyridine [4,4‧-BiPyH2]2 + cations, Cl anions and Au adatoms, provided from substrate by means of the adsorbate-induced surface phase transition of a surface reconstruction. Its surface and bulk structures were characterized by scanning tunneling microscopy (STM), secondary ion mass spectrometry (SIMS), and Raman spectroscopy. STM results reveal growth of the first [4,4‧-BiPyH2]2 + layer on top of the p(√{ 3} ×√{ 3})" separators=", R 30 ° chlorine overlayer formed on the Au(111) surface. These two layers are found to provide a platform for a following three-dimensional growth facilitated by hydrogen bonding, aurophilic and π-π stacking interactions.

  17. Investigation of the influence of hybrid layers on the life time of hot forging dies

    Directory of Open Access Journals (Sweden)

    S. Legutko

    2013-04-01

    Full Text Available The paper deals with the issues related in the process of drop forging with special attention paid to the durability of forging tools. It presents the results of industrial investigation of the influence of hybrid layers on hot forging dies. The effectiveness of hybrid layers type nitrided layer/PVD coating applied for extending the life of forging tools whose working surfaces are exposed to such complex exploitation conditions as, among others, cyclically varying high thermal and mechanical loads, as well as intensive abrasion at raised temperature. The examination has been performed on a set of forging tools made of Unimax steel and intended for forging steel rings of gear box synchronizer in the factory FAS in Swarzedz (Poland.

  18. Characterizing microscale aluminum composite layer properties on silicon solar cells with hybrid 3D scanning force measurements

    Science.gov (United States)

    Bae, Sung-Kuk; Choi, Beomjoon; Chung, Haseung; Shin, Seungwon; Song, Hee-Eun; Seo, Jung Hwan

    2016-03-01

    This article presents a novel technique to estimate the mechanical properties of the aluminum composite layer on silicon solar cells by using a hybrid 3-dimensional laser scanning force measurement (3-D LSFM) system. The 3-D LSFM system measures the material properties of sub-layers constituting a solar cell. This measurement is critical for realizing high-efficient ultra-thin solar cells. The screen-printed aluminum layer, which significantly affects the bowing phenomenon, is separated from the complete solar cell by removing the silicon (Si) layer with deep reactive ion etching. An elastic modulus of ~15.1 GPa and a yield strength of ~35.0 MPa for the aluminum (Al) composite layer were obtained by the 3-D LSFM system. In experiments performed for 6-inch Si solar cells, the bowing distances decreased from 12.02 to 1.18 mm while the Si layer thicknesses increased from 90 to 190 μm. These results are in excellent agreement with the theoretical predictions for ultra-thin Si thickness (90 μm) based on the obtained Al composite layer properties.

  19. Characterizing microscale aluminum composite layer properties on silicon solar cells with hybrid 3D scanning force measurements.

    Science.gov (United States)

    Bae, Sung-Kuk; Choi, Beomjoon; Chung, Haseung; Shin, Seungwon; Song, Hee-eun; Seo, Jung Hwan

    2016-03-07

    This article presents a novel technique to estimate the mechanical properties of the aluminum composite layer on silicon solar cells by using a hybrid 3-dimensional laser scanning force measurement (3-D LSFM) system. The 3-D LSFM system measures the material properties of sub-layers constituting a solar cell. This measurement is critical for realizing high-efficient ultra-thin solar cells. The screen-printed aluminum layer, which significantly affects the bowing phenomenon, is separated from the complete solar cell by removing the silicon (Si) layer with deep reactive ion etching. An elastic modulus of ~15.1 GPa and a yield strength of ~35.0 MPa for the aluminum (Al) composite layer were obtained by the 3-D LSFM system. In experiments performed for 6-inch Si solar cells, the bowing distances decreased from 12.02 to 1.18 mm while the Si layer thicknesses increased from 90 to 190 μm. These results are in excellent agreement with the theoretical predictions for ultra-thin Si thickness (90 μm) based on the obtained Al composite layer properties.

  20. Polyester based hybrid organic coatings

    Science.gov (United States)

    Wang, Xiaojiang

    Polyesters are a class of polymers widely used in organic coatings applications. In this work, four types of organic coatings based on polyester polyols were prepared: UV-curable polyester/poly(meth)acrylate coatings, thermal curable polyester polyurethane-urea coatings, thermal curable non-isocyanate polyurethane coatings, and UV-curable non-isocyanate polyurethane coatings. Polyester/poly(meth)acrylate block copolymers are synthesized using a combination of polycondensation and Atom-Transfer Radical Polymerization (ATRP). All block copolymers are characterized by means of Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC). In the case of unsaturated-polyester-based block copolymers the main chain double bond in the polyester backbone remains almost unaffected during ATRP. The unsaturated block copolymers are crosslinkable and can form networks upon photo-irradiation in the presence of a suitable photoinitiator. These copolymers might be interesting candidates for coatings with better overall properties than those based on neat polyesters. Thermal curable polyester polyol based Polyurethane-Urea (PUU) coatings were formulated using Partially Blocked HDI isocyanurate (PBH), Isophorone Diamine (IPDA), and polyester polyol. As a comparison, the polyurethane coatings (PU) without adding IPDA were also prepared. The mechanical and viscoelastic properties of the PUU and PU coating were investigated by using tensile test and Dynamic Mechanical Thermal Analyzer (DMTA). It was found that PUU coating exhibited higher crosslink density, Tg, tensile modulus and strength than the corresponding PU coating. Thermal curable non-isocyanate polyurethane coatings were prepared by using polyamine and cyclic carbonate terminated polyester. Cyclic carbonate terminated polyester was synthesized from the reaction of the carbon dioxide and epoxidized polyester which was prepared from the polyester polyol. The properties of the epoxidized and cyclic carbonate

  1. Self-Assembly of 1D/2D Hybrid Nanostructures Consisting of a Cd(II Coordination Polymer and NiAl-Layered Double Hydroxides

    Directory of Open Access Journals (Sweden)

    Gonzalo Abellán

    2015-12-01

    Full Text Available The preparation and characterization of a novel hybrid material based on the combination of a 2D-layered double hydroxide (LDH nanosheets and a 1D-coordination polymer (1D-CP has been achieved through a simple mixture of suspensions of both building blocks via an exfoliation/restacking approach. The hybrid material has been thoroughly characterized demonstrating that the 1D-CP moieties are intercalated as well as adsorbed on the surface of the LDH, giving rise to a layered assembly with the coexistence of the functionalities of their initial constituents. This hybrid represents the first example of the assembly of 1D/2D nanomaterials combining LDH with CP and opens the door for a plethora of different functional hybrid systems.

  2. Fabrication of hybrid graphene oxide/polyelectrolyte capsules by means of layer-by-layer assembly on erythrocyte cell templates.

    Science.gov (United States)

    Irigoyen, Joseba; Politakos, Nikolaos; Diamanti, Eleftheria; Rojas, Elena; Marradi, Marco; Ledezma, Raquel; Arizmendi, Layza; Rodríguez, J Alberto; Ziolo, Ronald F; Moya, Sergio E

    2015-01-01

    A novel and facile method was developed to produce hybrid graphene oxide (GO)-polyelectrolyte (PE) capsules using erythrocyte cells as templates. The capsules are easily produced through the layer-by-layer technique using alternating polyelectrolyte layers and GO sheets. The amount of GO and therefore its coverage in the resulting capsules can be tuned by adjusting the concentration of the GO dispersion during the assembly. The capsules retain the approximate shape and size of the erythrocyte template after the latter is totally removed by oxidation with NaOCl in water. The PE/GO capsules maintain their integrity and can be placed or located on other surfaces such as in a device. When the capsules are dried in air, they collapse to form a film that is approximately twice the thickness of the capsule membrane. AFM images in the present study suggest a film thickness of approx. 30 nm for the capsules in the collapsed state implying a thickness of approx. 15 nm for the layers in the collapsed capsule membrane. The polyelectrolytes used in the present study were polyallylamine hydrochloride (PAH) and polystyrenesulfonate sodium salt (PSS). Capsules where characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and Raman microscopy, the constituent layers by zeta potential and GO by TEM, XRD, and Raman and FTIR spectroscopies.

  3. Fabrication of hybrid graphene oxide/polyelectrolyte capsules by means of layer-by-layer assembly on erythrocyte cell templates

    Directory of Open Access Journals (Sweden)

    Joseba Irigoyen

    2015-12-01

    Full Text Available A novel and facile method was developed to produce hybrid graphene oxide (GO–polyelectrolyte (PE capsules using erythrocyte cells as templates. The capsules are easily produced through the layer-by-layer technique using alternating polyelectrolyte layers and GO sheets. The amount of GO and therefore its coverage in the resulting capsules can be tuned by adjusting the concentration of the GO dispersion during the assembly. The capsules retain the approximate shape and size of the erythrocyte template after the latter is totally removed by oxidation with NaOCl in water. The PE/GO capsules maintain their integrity and can be placed or located on other surfaces such as in a device. When the capsules are dried in air, they collapse to form a film that is approximately twice the thickness of the capsule membrane. AFM images in the present study suggest a film thickness of approx. 30 nm for the capsules in the collapsed state implying a thickness of approx. 15 nm for the layers in the collapsed capsule membrane. The polyelectrolytes used in the present study were polyallylamine hydrochloride (PAH and polystyrenesulfonate sodium salt (PSS. Capsules where characterized by transmission electron microscopy (TEM, atomic force microscopy (AFM, dynamic light scattering (DLS and Raman microscopy, the constituent layers by zeta potential and GO by TEM, XRD, and Raman and FTIR spectroscopies.

  4. Polymer and small molecule based hybrid light source

    Science.gov (United States)

    Choong, Vi-En; Choulis, Stelios; Krummacher, Benjamin Claus; Mathai, Mathew; So, Franky

    2010-03-16

    An organic electroluminescent device, includes: a substrate; a hole-injecting electrode (anode) coated over the substrate; a hole injection layer coated over the anode; a hole transporting layer coated over the hole injection layer; a polymer based light emitting layer, coated over the hole transporting layer; a small molecule based light emitting layer, thermally evaporated over the polymer based light emitting layer; and an electron-injecting electrode (cathode) deposited over the electroluminescent polymer layer.

  5. SCAN-based hybrid and double-hybrid density functionals from parameter-free models

    CERN Document Server

    Hui, Kerwin

    2015-01-01

    By incorporating the nonempirical SCAN semilocal density functional [Sun, Ruzsinszky, and Perdew, Phys. Rev. Lett. 115, 036402 (2015)] in the underlying expression, we propose one hybrid (SCAN0) and three double-hybrid (SCAN0-DH, SCAN-QIDH, and SCAN0-2) density functionals, which are free of any empirical parameter. The SCAN-based hybrid and double-hybrid functionals consistently outperform their parent SCAN semilocal functional for a wide range of applications. The SCAN-based semilocal, hybrid, and double-hybrid functionals generally perform better than the corresponding PBE-based functionals. In addition, the SCAN0-2 and SCAN-QIDH double-hybrid functionals significantly reduce the qualitative failures of the SCAN semilocal functional, such as the self-interaction error and noncovalent interaction error, extending the applicability of the SCAN-based functionals to a very diverse range of systems.

  6. Thin film encapsulation for organic light-emitting diodes using inorganic/organic hybrid layers by atomic layer deposition.

    Science.gov (United States)

    Zhang, Hao; Ding, He; Wei, Mengjie; Li, Chunya; Wei, Bin; Zhang, Jianhua

    2015-01-01

    A hybrid nanolaminates consisting of Al2O3/ZrO2/alucone (aluminum alkoxides with carbon-containing backbones) grown by atomic layer deposition (ALD) were reported for an encapsulation of organic light-emitting diodes (OLEDs). The electrical Ca test in this study was designed to measure the water vapor transmission rate (WVTR) of nanolaminates. We found that moisture barrier performance was improved with the increasing of the number of dyads (Al2O3/ZrO2/alucone) and the WVTR reached 8.5 × 10(-5) g/m(2)/day at 25°C, relative humidity (RH) 85%. The half lifetime of a green OLED with the initial luminance of 1,500 cd/m(2) reached 350 h using three pairs of the Al2O3 (15 nm)/ZrO2 (15 nm)/alucone (80 nm) as encapsulation layers.

  7. DNA biosensors based on layer-by-layer self-assembled multilayer films of carbon nanotubes and gold nanoparticles

    Science.gov (United States)

    Xiao, Yiyun; Dai, Zhao; Zhang, Jimei; Pang, Jiechun; Xu, Shichao; Zheng, Guo

    2009-07-01

    A novel DNA biosensor based on layer-by-layer self-assembled multi-walled carbon nanotubes (MWNTs) and gold nano-particles (GNPs) was presented in this paper, in which the probe HS-ssDNA oligonucleotides, MWNTs and GNPs were all covalently immobilized by chemical Au-Sulphide bonding. Firstly, the super short MWNTs were prepared and modified with thio groups which could be self-assembled onto the surface of Au elcetrode by Au-sulphide bonding, then the GNPs were chemically adhered to the surfaces of MWNTs by forming Au-sulphide bonding again, at last the selfassamble of probe DNA oligonucleotides were also covalently immobilized via Au-sulphide bonding between thio groups at the ends of the DNA oligonucleotides and GNPs. Hybridization between the probe HS-ssDNA oligonucleotides and target DNA oligonucleotides was confirmed by the changes in the voltammetric peak of an anionic intercalator, anthraquinone-2,6-disulfonic acid (AQDS) as a hybridization indicator. The cyclic voltammetric and differential pulse voltammetry responses demonstrated that the DNA biosensors based on Layer-by-layer self-assembled multilayer films of MWNTs and NGPs offer a higher hybridization efficiency and selectivity compared to those based on only random MWNTs or GNPs.

  8. Collaborative Multi-Layer Network Coding in Hybrid Cellular Cognitive Radio Networks

    KAUST Repository

    Moubayed, Abdallah J.

    2015-05-01

    In this paper, as an extension to [1], we propose a prioritized multi-layer network coding scheme for collaborative packet recovery in hybrid (interweave and underlay) cellular cognitive radio networks. This scheme allows the uncoordinated collaboration between the collocated primary and cognitive radio base-stations in order to minimize their own as well as each other\\'s packet recovery overheads, thus by improving their throughput. The proposed scheme ensures that each network\\'s performance is not degraded by its help to the other network. Moreover, it guarantees that the primary network\\'s interference threshold is not violated in the same and adjacent cells. Yet, the scheme allows the reduction of the recovery overhead in the collocated primary and cognitive radio networks. The reduction in the cognitive radio network is further amplified due to the perfect detection of spectrum holes which allows the cognitive radio base station to transmit at higher power without fear of violating the interference threshold of the primary network. For the secondary network, simulation results show reductions of 20% and 34% in the packet recovery overhead, compared to the non-collaborative scheme, for low and high probabilities of primary packet arrivals, respectively. For the primary network, this reduction was found to be 12%. © 2015 IEEE.

  9. Collaborative Multi-Layer Network Coding For Hybrid Cellular Cognitive Radio Networks

    KAUST Repository

    Moubayed, Abdallah J.

    2014-05-01

    In this thesis, as an extension to [1], we propose a prioritized multi-layer network coding scheme for collaborative packet recovery in hybrid (interweave and underlay) cellular cognitive radio networks. This scheme allows the uncoordinated collaboration between the collocated primary and cognitive radio base-stations in order to minimize their own as well as each other’s packet recovery overheads, thus by improving their throughput. The proposed scheme ensures that each network’s performance is not degraded by its help to the other network. Moreover, it guarantees that the primary network’s interference threshold is not violated in the same and adjacent cells. Yet, the scheme allows the reduction of the recovery overhead in the collocated primary and cognitive radio networks. The reduction in the cognitive radio network is further amplified due to the perfect detection of spectrum holes which allows the cognitive radio base station to transmit at higher power without fear of violating the interference threshold of the primary network. For the secondary network, simulation results show reductions of 20% and 34% in the packet recovery overhead, compared to the non-collaborative scheme, for low and high probabilities of primary packet arrivals, respectively. For the primary network, this reduction was found to be 12%. Furthermore, with the use of fractional cooperation, the average recovery overhead is further reduced by around 5% for the primary network and around 10% for the secondary network when a high fractional cooperation probability is used.

  10. A Scalable and Highly Configurable Cache-Aware Hybrid Flash Translation Layer

    Directory of Open Access Journals (Sweden)

    Jalil Boukhobza

    2014-03-01

    Full Text Available This paper presents a cache-aware configurable hybrid flash translation layer (FTL, named CACH-FTL. It was designed based on the observation that most state-of­­-the-art flash-specific cache systems above FTLs flush groups of pages belonging to the same data block. CACH-FTL relies on this characteristic to optimize flash write operations placement, as large groups of pages are flushed to a block-mapped region, named BMR, whereas small groups are buffered into a page-mapped region, named PMR. Page group placement is based on a configurable threshold defining the limit under which it is more cost-effective to use page mapping (PMR and wait for grouping more pages before flushing to the BMR. CACH-FTL is scalable in terms of mapping table size and flexible in terms of Input/Output (I/O workload support. CACH-FTL performs very well, as the performance difference with the ideal page-mapped FTL is less than 15% in most cases and has a mean of 4% for the best CACH-FTL configurations, while using at least 78% less memory for table mapping storage on RAM.

  11. Hybrid Organic-Inorganic Films Grown Using Molecular Layer Deposition

    Science.gov (United States)

    2011-03-01

    discussed below for the MLD of the alucone based on TMA and glycerol . Alternatively, a heterobifunctional precursor, such as ethanolamine, HO- CH2...amine-terminated surface functional groups to reform carboxylic groups through a ring-opening reaction in reaction C given by Eqn. 5. The three-step...small amount of cross-linking in the MLD film. These problems with the TMA + EG MLD system led to the recent exploration of the TMA + glycerol system

  12. New, hybrid pectin-based biosorbents

    Science.gov (United States)

    Jakóbik-Kolon, Agata; Milewski, Andrzej K.; Karoń, Krzysztof; Bok-Badura, Joanna

    2016-01-01

    ABSTRACT In this work hybrid pectin-based biosorbents with secondary polysaccharide additives (gellan, carob and xanthan gum, ratio to pectin 1:1, 1:1 and 1:3, respectively) were obtained at two temperatures. The presence of these additives in prepared beads was confirmed by Raman spectra. The SEM micrographs show better homogeneity of blends and grater differences between structures of beads with various additives obtained at higher temperature. The sorption capacity of our hybrid biosorbents as well as sole pectin sorbent is rather the same, and equals 0.85 and 0.70 mmol/g for lead and cadmium, respectively, in pH 4–6. PMID:27812233

  13. Hybrid Communication System Based on OFDM

    Directory of Open Access Journals (Sweden)

    2013-11-01

    Full Text Available A Hybrid architecture between terrestrial and satellite networks based on Orthogonal Frequency Division Multiplexing (OFDM is employed here. In hybrid architecture, the users will be able to avail the services through the terrestrial networks as well as the satellite networks. The users located in urban areas will be served by the existing terrestrial mobile networks and similarly the one located in rural areas will be provided services through the satellite networks. The technique which is used to achieve this objective is called Pre-FFT adaptive beamforming also called time domain beamforming. When the data is received at the satellite end, the Pre-FFT adaptive beamforming extracts the desired user data from the interferer user by applying the complex weights to the received symbol. The weight for the next symbol is then updated by Least Mean Square (LMS algorithm and then is applied to it. This process is carried out till all the desired user data is extracted.

  14. White organic light emitting devices with hybrid emissive layers combining phosphorescence and fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Lei Gangtie; Chen Xiaolan; Wang Lei; Zhu Meixiang; Zhu Weiguo [Key Lab of Environmental-friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105 (China); Wang Liduo; Qiu Yong [Key Lab of Organic-Optoelectronics and Molecular Sciences of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084 (China)], E-mail: lgt@xtu.edu.cn

    2008-05-21

    We fabricated a white organic light-emitting diode (WOLED) by hybrid emissive layers which combined phosphorescence with fluorescence. In this device, the thin layer of 4-(dicyanomethylene)-2-(t-butyl)-6-(1, 1, 7, 7-tetramethyljulolidyl-9-enyl)-4H-pyran played the role of undoped red emissive layer which was inserted between two blue phosphorescence emissive layers. The blue phosphorescent dye was bis[(4, 6-difluorophenyl)-pyridinato-N, C{sup 2}] (picolinato) Ir(III), which was doped in the host material, N, N'-dicarbazolyl-1, 4-dimethene-benzene. The WOLED showed stable Commission Internationale de L'Eclairage coordinates and a high efficency of 9.6 cd A{sup -1} when the current density was 1.8 A m{sup -2}. The maximum luminance of the device achieved was 17 400 cd m{sup -2} when the current density was 3000 A m{sup -2}.

  15. A novel hybrid material: an inorganic silica aerogel core encapsulated with a tunable organic alginate aerogel layer

    OpenAIRE

    Ülker, Zeynep; Erkey, Can

    2014-01-01

    A novel layered material consisting of a silica aerogel core encapsulated by an alginate aerogel layer was developed. The components of the hybrid aerogel had the high surface area and high porosity of pure aerogels which should lead to development of new layered systems for a wide variety of applications.

  16. Growth Mechanism of a Hybrid Structure Consisting of a Graphite Layer on Top of Vertical Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Nicolo' Chiodarelli

    2012-01-01

    Full Text Available Graphene and carbon nanotubes (CNTs are both carbon-based materials with remarkable optical and electronic properties which, among others, may find applications as transparent electrodes or as interconnects in microchips, respectively. This work reports on the formation of a hybrid structure composed of a graphitic carbon layer on top of vertical CNT in a single deposition process. The mechanism of deposition is explained according to the thickness of catalyst used and the atypical growth conditions. Key factors dictating the hybrid growth are the film thickness and the time dynamic through which the catalyst film dewets and transforms into nanoparticles. The results support the similarities between chemical vapor deposition processes for graphene, graphite, and CNT.

  17. Compact Layers of Hybrid Halide Perovskites Fabricated via the Aerosol Deposition Process—Uncoupling Material Synthesis and Layer Formation

    Directory of Open Access Journals (Sweden)

    Fabian Panzer

    2016-04-01

    Full Text Available We present the successful fabrication of CH3NH3PbI3 perovskite layers by the aerosol deposition method (ADM. The layers show high structural purity and compactness, thus making them suitable for application in perovskite-based optoelectronic devices. By using the aerosol deposition method we are able to decouple material synthesis from layer processing. Our results therefore allow for enhanced and easy control over the fabrication of perovskite-based devices, further paving the way for their commercialization.

  18. Novel Hybrid Ablative/Ceramic Layered Composite for Earth Re-entry Thermal Protection: Microstructural and Mechanical Performance

    Science.gov (United States)

    Triantou, K.; Mergia, K.; Marinou, A.; Vekinis, G.; Barcena, J.; Florez, S.; Perez, B.; Pinaud, G.; Bouilly, J.-M.; Fischer, W. P. P.

    2015-04-01

    In view of spacecraft re-entry applications into planetary atmospheres, hybrid thermal protection systems based on layered composites of ablative materials and ceramic matrix composites are investigated. Joints of ASTERM™ lightweight ablative material with Cf/SiC (SICARBON™) were fabricated using commercial high temperature inorganic adhesives. Sound joints without defects are produced and very good bonding of the adhesive with both base materials is observed. Mechanical shear tests under ambient conditions and in liquid nitrogen show that mechanical failure always takes place inside the ablative material with no decohesion of the interface of the adhesive layer with the bonded materials. Surface treatment of the ablative surface prior to bonding enhances both the shear strength and the ultimate shear strain by up to about 60%.

  19. Improvement Of Tools Durability By Application Of Hybrid Layer Of Nitrided/PECVD Coating.

    OpenAIRE

    Gronostajski Z.; Kaszuba M.; Paschke H.; Zakrzewski T.; Rogaliński G.

    2015-01-01

    In the process of die hot forging the tools are subjected to three main factors leading to their destruction: the intensive thermal shocks, cyclically variable mechanical loads and intensive friction. The above mentioned factors causing destruction in the process of hot forging and warm forging concern mainly the surface of tools. Hybrid technique nitrided/PECVD belong to the latest methods of modifying the properties of the surface layer. In the paper the application of this technique for fo...

  20. Study of organo-hybrid layered double hydroxides by medium and near infrared spectroscopy

    Science.gov (United States)

    Mora, Manuel; López, M. Isabel; Jiménez-Sanchidrián, César; Ruiz, J. Rafael

    2011-03-01

    An Mg/Al layered double hydroxide (LDH) containing carbonate ion in its interlayer region was examined by medium infrared (MIR) and near infrared reflectance spectroscopy (NIRS). The MIR and NIR spectroscopy techniques was also used to study two organo-hybrid LDHs containing interlayer dodecylbenzenesulphonate (DBS) and dodecylsulphate (DS) ions, respectively. The NIR spectra for the latter solids were found to exhibit the overtone and combination bands for the hydroxyl groups in addition to those typical bands of the organic host functions.

  1. Use of a specific MMP inhibitor (Galardin) for preservation of hybrid layer

    Science.gov (United States)

    Breschi, Lorenzo; Martin, Patrizia; Mazzoni, Annalisa; Nato, Fernando; Carrilho, Marcela; Tjäderhane, Leo; Visintini, Erika; Cadenaro, Milena; Tay, Franklin R; De Stefano Dorigo, Elettra; Pashley, David H

    2013-01-01

    Objective Dentinal MMPs have been claimed to contribute to the auto-degradation of collagen fibrils within incompletely resin-infiltrated hybrid layers and their inhibition may, therefore, slow the degradation of hybrid layer. This study aimed to determine the contribution of a synthetic MMPs inhibitor (Galardin) to the proteolytic activity of dentinal MMPs and to the morphological and mechanical features of hybrid layers after aging. Methods Dentin powder obtained from human molars was treated with Galardin or chlorhexidine digluconate and zymographically analyzed. Microtensile bond strength was also evaluated in extracted human teeth. Exposed dentin was etched with 35% phosphoric acid and specimens were assigned to (1) pre-treatment with Galardin as additional primer for 30s; (2) no pre-treatment. A two-step etch-and-rinse adhesive (Adper Scotchbond 1XT, 3M ESPE) was then applied in accordance with manufacturer's instructions and resin composite build-ups were created. Specimens were immediately tested for their microtensile bond strength or stored in artificial saliva for 12 months prior to being tested. Data were evaluated by two-way ANOVA and Tukey's tests (〈=0.05). Additional specimens were prepared for interfacial nanoleakage analysis under light microscopy and TEM, quantified by two independent observers and statistically analyzed (|2 test, 〈=0.05). Results The inhibitory effect of Galardin on dentinal MMPs was confirmed by zymographic analysis, as complete inhibition of both MMP-2 and -9 was observed. The use of Galardin had no effect on immediate bond strength, while it significantly decreased bond degradation after 1 year (pdentinal MMPs was inhibited by the use of Galardin in a therapeutic primer. Galardin also partially preserved the mechanical integrity of the hybrid layer created by a two-step etch-and-rinse adhesive after artificial aging. PMID:20299089

  2. Bond Strength between Hybrid Fiber-Reinforced Lightweight Aggregate Concrete Substrate and Self-Compacting Concrete as Topping Layer

    Directory of Open Access Journals (Sweden)

    Slamet Widodo

    2017-01-01

    Full Text Available Structural performance evaluation of composite concrete slabs that were constructed using partially precast concreting system which utilized Hybrid Fiber-Reinforced Lightweight Aggregate Concrete (HyFRLWAC as stay in-place formwork and self-compacting concrete (SCC as topping layer was conducted in this research. This paper focused on determining the appropriate strength limit criteria of interface between two different concrete layers. The tensile strength was tested using pull-off test, while concrete cohesion was investigated based on modified bisurface shear test, and dual L-shaped shear test was used to determine the effect of normal force on the shear strength of concrete interface. Sample variants were designed based on the substrate surface conditions, compressive strength of the topping layer, and magnitude of perpendicular normal force acting on interface area. The substrate surfaces were prepared in as-placed and grooved conditions for tensile test, cohesion, and shear strength test. Test results indicate that tensile strength, cohesion, and shear strength of the concrete interface are affected by surface condition of the substrate, compressive strength of the topping layer, and the normal force acting perpendicularly on the concrete interface area. Proposed formulation for bond strength prediction between HyFRLWAC as substrate and SCC as topping layer is also presented in this paper.

  3. Enhanced Capacitance of Hybrid Layered Graphene/Nickel Nanocomposite for Supercapacitors

    Science.gov (United States)

    Mohd Zaid, Norsaadatul Akmal; Idris, Nurul Hayati

    2016-08-01

    In this work, Ni nanoparticles were directly decorated on graphene (G) nanosheets via mechanical ball milling. Based on transmission electron microscopy observations, the Ni nanoparticles were well dispersed and attached to the G nanosheet without any agglomerations. Electrochemical results showed that the capacitance of a G/Ni nanocomposite was 275 F g-1 at a current density of 2 A g-1, which is higher than the capacitance of bare G (145 F g-1) and bare Ni (3 F g-1). The G/Ni electrode also showed superior performance at a high current density, exhibiting a capacitance of 190 F g-1 at a current density of 5 A g-1 and a capacitance of 144 F g-1 at a current density of 10 A g-1. The equivalent series resistance for G/Ni nanocomposites also decreased. The enhanced performance of this hybrid supercapacitor is best described by the synergistic effect, i.e. dual charge-storage mechanism, which is demonstrated by electrical double layer and pseudocapacitance materials. Moreover, a high specific surface area and electrical conductivity of the materials enhanced the capacitance. These results indicate that the G/Ni nanocomposite is a potential supercapacitor.

  4. Polarized light source based on graphene-nanoribbon hybrid structure

    Science.gov (United States)

    Xu, Pengfei; Zhang, Han; Qian, Haoliang; Chen, Bigeng; Jiang, Xiaoshun; Wu, Yuanpeng; Liu, Xiaowei; Liu, Xu; Yang, Qing

    2017-07-01

    Nanoscale light source is the key element for on-chip integrated optical communication system. As an important property of light source, polarization can be exploited to improve the information capacity of optical communication and the sensitivity of optical sensing. We demonstrate a novel TE-polarized light source based on graphene-nanoribbon (G-NR) hybrid structure. Thanks to the polarizing dependent absorption along graphene layer, the random polarized emission of nanoribbon (NR) can be transferred into the same TE polarization. In addition, lasing action in G-NR hybrid structure is also investigated. We attribute the polarization control to the differential attenuation of electromagnetic modes in graphene. Our simulation revealed electromagnetic field distribution and far field polar images of TE and TM modes in nanoribbon, which is consistent with experimental results. The compact G-NR hybrid structure light source offers a new way to realize the polarization controllable nanoscale light source and facilitate the practical applications of nanowire or nanoribbon light source.

  5. Failure assessment of aluminum liner based filament-wound hybrid riser subjected to internal hydrostatic pressure

    Science.gov (United States)

    Dikshit, Vishwesh; Seng, Ong Lin; Maheshwari, Muneesh; Asundi, A.

    2015-03-01

    The present study describes the burst behavior of aluminum liner based prototype filament-wound hybrid riser under internal hydrostatic pressure. The main objective of present study is to developed an internal pressure test rig set-up for filament-wound hybrid riser and investigate the failure modes of filament-wound hybrid riser under internal hydrostatic burst pressure loading. The prototype filament-wound hybrid riser used for burst test consists of an internal aluminum liner and outer composite layer. The carbon-epoxy composites as part of the filament-wound hybrid risers were manufactured with [±55o] lay-up pattern with total composite layer thickness of 1.6 mm using a CNC filament-winding machine. The burst test was monitored by video camera which helps to analyze the failure mechanism of the fractured filament-wound hybrid riser. The Fiber Bragg Grating (FBG) sensor was used to monitor and record the strain changes during burst test of prototype filament-wound hybrid riser. This study shows good improvements in burst strength of filament-wound hybrid riser compared to the monolithic metallic riser. Since, strain measurement using FBG sensors has been testified as a reliable method, we aim to further understand in detail using this technique.

  6. Hybrid-Based Dense Stereo Matching

    Science.gov (United States)

    Chuang, T. Y.; Ting, H. W.; Jaw, J. J.

    2016-06-01

    Stereo matching generating accurate and dense disparity maps is an indispensable technique for 3D exploitation of imagery in the fields of Computer vision and Photogrammetry. Although numerous solutions and advances have been proposed in the literature, occlusions, disparity discontinuities, sparse texture, image distortion, and illumination changes still lead to problematic issues and await better treatment. In this paper, a hybrid-based method based on semi-global matching is presented to tackle the challenges on dense stereo matching. To ease the sensitiveness of SGM cost aggregation towards penalty parameters, a formal way to provide proper penalty estimates is proposed. To this end, the study manipulates a shape-adaptive cross-based matching with an edge constraint to generate an initial disparity map for penalty estimation. Image edges, indicating the potential locations of occlusions as well as disparity discontinuities, are approved by the edge drawing algorithm to ensure the local support regions not to cover significant disparity changes. Besides, an additional penalty parameter 𝑃𝑒 is imposed onto the energy function of SGM cost aggregation to specifically handle edge pixels. Furthermore, the final disparities of edge pixels are found by weighting both values derived from the SGM cost aggregation and the U-SURF matching, providing more reliable estimates at disparity discontinuity areas. Evaluations on Middlebury stereo benchmarks demonstrate satisfactory performance and reveal the potency of the hybrid-based dense stereo matching method.

  7. 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....

  8. Highly condensed fluorinated methacrylate hybrid material for transparent low-kappa passivation layer in LCD-TFT.

    Science.gov (United States)

    Oh, Ji-Hoon; Kwak, Seung-Yeon; Yang, Seung-Cheol; Bae, Byeong-Soo

    2010-03-01

    Photocurable and highly condensed fluorinated methacrylate oligosiloxane, with a low dielectric constant (kappa = 2.54), was prepared by a nonhydrolytic sol-gel condensation reaction. The oligosiloxane resin was then spin-coated, photocured, and thermally baked in order to fabricate a fluorinated methacrylate hybrid material (FM hybrimer) thin film. This study investigated the application of this FM hybrimer film as a low-kappa passivation layer in LCD-based thin film transistors (TFT). It was found that a dielectric constant as low as kappa = 2.54 could be obtained, without introducing pores in the dense FM hybrimer films. This study compares FM hybrimer film characteristics with those required for passivation layers in LCD-TFTs, including thermal stability, optical transmittance, hydrophobicity, gap fill, and planarization effects as well as electrical insulation.

  9. Layered Textures for Image-Based Rendering

    Institute of Scientific and Technical Information of China (English)

    en-Cheng Wang; ui-Yu Li; in Zheng; n-Hua Wu

    2004-01-01

    An extension to texture mapping is given in this paper for improving the efficiency of image-based rendering. For a depth image with an orthogonal displacement at each pixel, it is decomposed by the displacement into a series of layered textures (LTs) with each one having the same displacement for all its texels. Meanwhile,some texels of the layered textures are interpolated for obtaining a continuous 3D approximation of the model represented in the depth image. Thus, the plane-to-plane texture mapping can be used to map these layered textures to produce novel views and the advantages can be obtained as follows: accelerating the rendering speed,supporting the 3D surface details and view motion parallax, and avoiding the expensive task of hole-filling in the rendering stage. Experimental results show the new method can produce high-quality images and run faster than many famous image-based rendering techniques.

  10. Layered double hydroxide-oxidized carbon nanotube hybrids as highly efficient flame retardant nanofillers for polypropylene

    Science.gov (United States)

    Gao, Yanshan; Zhang, Yu; Williams, Gareth R.; O’Hare, Dermot; Wang, Qiang

    2016-01-01

    Aqueous miscible organic layered double hydroxides (AMO-LDHs) can act as organophilic inorganic flame retardant nanofillers for unmodified non-polar polymers. In this contribution, AMO [Mg3Al(OH)8](CO3)0.5·yH2O LDH–oxidized carbon nanotube (AMO-LDH–OCNT) hybrids are shown to perform better than the equivalent pure AMO-LDH. A synergistic effect between the AMO-LDH and OCNT was observed; this endows the hybrid material with enhanced flame retardancy, thermal stability, and mechanical properties. The thermal stability of polypropylene (PP) was significantly enhanced by adding AMO-LDH–OCNT hybrids. For PP mixed with AMO-LDH–OCNT hybrids to produce a composite with 10 wt% LDH and 2 wt% OCNT, the 50% weight loss temperature was increased by 43 °C. Further, a system with 10 wt% of AMO-LDH and 1 wt% OCNT showed a peak heat release rate (PHRR) reduction of 40%, greater than the PHRR reduction with PP/20 wt% AMO-LDH (31%). The degree of dispersion (mixability) between AMO-LDH and OCNT has a significant effect on the flame retardant performance of the hybrids. In addition, the incorporation of AMO-LDH–OCNT hybrids led to better mechanical properties, such as higher tensile strength (27.5 MPa) and elongation at break (17.9%), than those composites containing only AMO-LDH (25.6 MPa and 7.5%, respectively). PMID:27752096

  11. Layered double hydroxide-oxidized carbon nanotube hybrids as highly efficient flame retardant nanofillers for polypropylene

    Science.gov (United States)

    Gao, Yanshan; Zhang, Yu; Williams, Gareth R.; O'Hare, Dermot; Wang, Qiang

    2016-10-01

    Aqueous miscible organic layered double hydroxides (AMO-LDHs) can act as organophilic inorganic flame retardant nanofillers for unmodified non-polar polymers. In this contribution, AMO [Mg3Al(OH)8](CO3)0.5·yH2O LDH-oxidized carbon nanotube (AMO-LDH-OCNT) hybrids are shown to perform better than the equivalent pure AMO-LDH. A synergistic effect between the AMO-LDH and OCNT was observed; this endows the hybrid material with enhanced flame retardancy, thermal stability, and mechanical properties. The thermal stability of polypropylene (PP) was significantly enhanced by adding AMO-LDH-OCNT hybrids. For PP mixed with AMO-LDH-OCNT hybrids to produce a composite with 10 wt% LDH and 2 wt% OCNT, the 50% weight loss temperature was increased by 43 °C. Further, a system with 10 wt% of AMO-LDH and 1 wt% OCNT showed a peak heat release rate (PHRR) reduction of 40%, greater than the PHRR reduction with PP/20 wt% AMO-LDH (31%). The degree of dispersion (mixability) between AMO-LDH and OCNT has a significant effect on the flame retardant performance of the hybrids. In addition, the incorporation of AMO-LDH-OCNT hybrids led to better mechanical properties, such as higher tensile strength (27.5 MPa) and elongation at break (17.9%), than those composites containing only AMO-LDH (25.6 MPa and 7.5%, respectively).

  12. Effects of Nd:YAG laser irradiation on the hybrid layer of different adhesive systems.

    Science.gov (United States)

    Ferreira, Leila S; Ferreira, Lisiane Soares; Francci, Carlos; Navarro, Ricardo Scarparo; Calheiros, Fernanda Calabró; Eduardo, Carlos de Paula

    2009-04-01

    The aim of this in vitro study was to evaluate the microtensile bond strength (microTBS) and hybrid layer morphology of different adhesive systems, either followed by treatment with Nd:YAG laser irradiation or not. Previous studies have shown the effects of Nd:YAG laser irradiation on the dentin surface at restoration margins, but there are few reports about the significance of the irradiation on the hybrid layer. The flattened coronal and root dentin samples of 24 bovine teeth were randomly divided into 8 groups, according to the adhesive system used -- Scotchbond Multi Purpose (SBMP) or Clearfil SE Bond (CSEB) -- and were either irradiated with Nd:YAG or not, with different parameters: 0.8 W/10 Hz, 0.8 W/20 Hz, 1.2 W/10 Hz, 1.2 W/20 Hz. The left sides of specimens were the control groups, and right sides were irradiated. A composite crown was built over bonded surfaces and stored in water (24 h at 37 degrees C). Specimens were sectioned vertically into slabs that were subjected to microTBS testing and observed by SEM. Control groups (27.81 +/- 1.38) showed statistically higher values than lased groups (21.37 +/- 0.99), and CSEB control group values (31.26 +/- 15.71) were statistically higher than those of SBMP (24.3 +/- 10.66). There were no significant differences between CSEB (20.34 +/- 10.01) and SBMP (22.43 +/- 9.82) lased groups. Among parameters tested, 0.8 W/10 Hz showed the highest value (25.54 +/- 11.74). Nd:YAG laser irradiation caused dentin to melt under the adhesive layer of both adhesive systems tested. With the parameters used in this study, Nd:YAG laser irradiation of the hybrid layer promoted morphological changes in dentin and negatively influenced the bond strength of both adhesive systems.

  13. Self-surface charge exfoliation and electrostatically coordinated 2D hetero-layered hybrids

    Science.gov (United States)

    Yang, Min-Quan; Xu, Yi-Jun; Lu, Wanheng; Zeng, Kaiyang; Zhu, Hai; Xu, Qing-Hua; Ho, Ghim Wei

    2017-02-01

    At present, the technological groundwork of atomically thin two-dimensional (2D) hetero-layered structures realized by successive thin film epitaxial growth is in principle constrained by lattice matching prerequisite as well as low yield and expensive production. Here, we artificially coordinate ultrathin 2D hetero-layered metal chalcogenides via a highly scalable self-surface charge exfoliation and electrostatic coupling approach. Specifically, bulk metal chalcogenides are spontaneously exfoliated into ultrathin layers in a surfactant/intercalator-free medium, followed by unconstrained electrostatic coupling with a dissimilar transition metal dichalcogenide, MoSe2, into scalable hetero-layered hybrids. Accordingly, surface and interfacial-dominated photocatalysis reactivity is used as an ideal testbed to verify the reliability of diverse 2D ultrathin hetero-layered materials that reveal high visible-light photoreactivity, efficient charge transfer and intimate contact interface for stable cycling and storage purposes. Such a synthetic approach renders independent thickness and composition control anticipated to advance the development of `design-and-build' 2D layered heterojunctions for large-scale exploration and applications.

  14. Self-surface charge exfoliation and electrostatically coordinated 2D hetero-layered hybrids

    Science.gov (United States)

    Yang, Min-Quan; Xu, Yi-Jun; Lu, Wanheng; Zeng, Kaiyang; Zhu, Hai; Xu, Qing-Hua; Ho, Ghim Wei

    2017-01-01

    At present, the technological groundwork of atomically thin two-dimensional (2D) hetero-layered structures realized by successive thin film epitaxial growth is in principle constrained by lattice matching prerequisite as well as low yield and expensive production. Here, we artificially coordinate ultrathin 2D hetero-layered metal chalcogenides via a highly scalable self-surface charge exfoliation and electrostatic coupling approach. Specifically, bulk metal chalcogenides are spontaneously exfoliated into ultrathin layers in a surfactant/intercalator-free medium, followed by unconstrained electrostatic coupling with a dissimilar transition metal dichalcogenide, MoSe2, into scalable hetero-layered hybrids. Accordingly, surface and interfacial-dominated photocatalysis reactivity is used as an ideal testbed to verify the reliability of diverse 2D ultrathin hetero-layered materials that reveal high visible-light photoreactivity, efficient charge transfer and intimate contact interface for stable cycling and storage purposes. Such a synthetic approach renders independent thickness and composition control anticipated to advance the development of ‘design-and-build' 2D layered heterojunctions for large-scale exploration and applications. PMID:28146147

  15. Cholesterol Biosensor Based on Entrapment of Monoenzyme and Multienzymes in Clay/Chitosan Hybrid Matrix

    Institute of Scientific and Technical Information of China (English)

    Dan Shan; YanNa Wang; HuaiGuo Xue; En Han

    2009-01-01

    @@ This work aimed at showing the interest of the composite material based on layered double hydroxides(LDHs) and chitosan (CHT) as suitable host matrix likely to immobilize enzyme onto electrode surface for amperometric biosensing application.This hybrid material combined the advantages of inorganic LDHs and organic biopolymer,CHT.

  16. 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.

  17. A Layered Zone Routing Algorithm in Ad Hoc Network Based on Matrix of Adjacency Connection

    Institute of Scientific and Technical Information of China (English)

    XU Guang-wei; LI Feng; SHI Xiu-jin; HUO Jia-zhen

    2007-01-01

    The hybrid routing protocol has received more attention recently than the proactive and the reactive, especially for large-scale and highly dynamic connection, in mobile ad hoc network. A crucial reason is that zone-layered is being utilized in the complex systems. A hybrid routing algorithm which is layered zone based on adjacency connection(LZBAC) is put forward under the background of a few members in network with steady position and link. The algorithm modifies storage structure of nodes and improves routing mechanism. The theoretical analysis and simulation testing testify that the algorithm costs shorter time of route finding and less delay than others.

  18. Multicast Routing Based on Hybrid Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    CAO Yuan-da; CAI Gui

    2005-01-01

    A new multicast routing algorithm based on the hybrid genetic algorithm (HGA) is proposed. The coding pattern based on the number of routing paths is used. A fitness function that is computed easily and makes algorithm quickly convergent is proposed. A new approach that defines the HGA's parameters is provided. The simulation shows that the approach can increase largely the convergent ratio, and the fitting values of the parameters of this algorithm are different from that of the original algorithms. The optimal mutation probability of HGA equals 0.50 in HGA in the experiment, but that equals 0.07 in SGA. It has been concluded that the population size has a significant influence on the HGA's convergent ratio when it's mutation probability is bigger. The algorithm with a small population size has a high average convergent rate. The population size has little influence on HGA with the lower mutation probability.

  19. Research Update: The electronic structure of hybrid perovskite layers and their energetic alignment in devices

    Directory of Open Access Journals (Sweden)

    Selina Olthof

    2016-09-01

    Full Text Available In recent years, the interest in hybrid organic–inorganic perovskites has increased at a rapid pace due to their tremendous success in the field of thin film solar cells. This area closely ties together fundamental solid state research and device application, as it is necessary to understand the basic material properties to optimize the performances and open up new areas of application. In this regard, the energy levels and their respective alignment with adjacent charge transport layers play a crucial role. Currently, we are lacking a detailed understanding about the electronic structure and are struggling to understand what influences the alignment, how it varies, or how it can be intentionally modified. This research update aims at giving an overview over recent results regarding measurements of the electronic structure of hybrid perovskites using photoelectron spectroscopy to summarize the present status.

  20. Design and implementation of a novel portable atomic layer deposition/chemical vapor deposition hybrid reactor.

    Science.gov (United States)

    Selvaraj, Sathees Kannan; Jursich, Gregory; Takoudis, Christos G

    2013-09-01

    We report the development of a novel portable atomic layer deposition chemical vapor deposition (ALD/CVD) hybrid reactor setup. Unique feature of this reactor is the use of ALD/CVD mode in a single portable deposition system to fabricate multi-layer thin films over a broad range from "bulk-like" multi-micrometer to nanometer atomic dimensions. The precursor delivery system and control-architecture are designed so that continuous reactant flows for CVD and cyclic pulsating flows for ALD mode are facilitated. A custom-written LabVIEW program controls the valve sequencing to allow synthesis of different kinds of film structures under either ALD or CVD mode or both. The entire reactor setup weighs less than 40 lb and has a relatively small footprint of 8 × 9 in., making it compact and easy for transportation. The reactor is tested in the ALD mode with titanium oxide (TiO2) ALD using tetrakis(diethylamino)titanium and water vapor. The resulting growth rate of 0.04 nm/cycle and purity of the films are in good agreement with literature values. The ALD/CVD hybrid mode is demonstrated with ALD of TiO2 and CVD of tin oxide (SnOx). Transmission electron microscopy images of the resulting films confirm the formation of successive distinct TiO2-ALD and SnO(x)-CVD layers.

  1. Design and implementation of a novel portable atomic layer deposition/chemical vapor deposition hybrid reactor

    Science.gov (United States)

    Selvaraj, Sathees Kannan; Jursich, Gregory; Takoudis, Christos G.

    2013-09-01

    We report the development of a novel portable atomic layer deposition chemical vapor deposition (ALD/CVD) hybrid reactor setup. Unique feature of this reactor is the use of ALD/CVD mode in a single portable deposition system to fabricate multi-layer thin films over a broad range from "bulk-like" multi-micrometer to nanometer atomic dimensions. The precursor delivery system and control-architecture are designed so that continuous reactant flows for CVD and cyclic pulsating flows for ALD mode are facilitated. A custom-written LabVIEW program controls the valve sequencing to allow synthesis of different kinds of film structures under either ALD or CVD mode or both. The entire reactor setup weighs less than 40 lb and has a relatively small footprint of 8 × 9 in., making it compact and easy for transportation. The reactor is tested in the ALD mode with titanium oxide (TiO2) ALD using tetrakis(diethylamino)titanium and water vapor. The resulting growth rate of 0.04 nm/cycle and purity of the films are in good agreement with literature values. The ALD/CVD hybrid mode is demonstrated with ALD of TiO2 and CVD of tin oxide (SnOx). Transmission electron microscopy images of the resulting films confirm the formation of successive distinct TiO2-ALD and SnOx-CVD layers.

  2. Fundamental phenomena on fuel decomposition and boundary-layer combustion processes with applications to hybrid rocket motors

    Science.gov (United States)

    Kuo, Kenneth K.; Lu, Yeu-Cherng; Chiaverini, Martin J.; Harting, George C.; Johnson, David K.; Serin, Nadir

    1995-01-01

    The experimental study on the fundamental processes involved in fuel decomposition and boundary-layer combustion in hybrid rocket motors is continuously being conducted at the High Pressure Combustion Laboratory of The Pennsylvania State University. This research will provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high-pressure, 2-D slab motor has been designed, manufactured, and utilized for conducting seven test firings using HTPB fuel processed at PSU. A total of 20 fuel slabs have been received from the Mcdonnell Douglas Aerospace Corporation. Ten of these fuel slabs contain an array of fine-wire thermocouples for measuring solid fuel surface and subsurface temperatures. Diagnostic instrumentation used in the test include high-frequency pressure transducers for measuring static and dynamic motor pressures and fine-wire thermocouples for measuring solid fuel surface and subsurface temperatures. The ultrasonic pulse-echo technique as well as a real-time x-ray radiography system have been used to obtain independent measurements of instantaneous solid fuel regression rates.

  3. Effect of hybrid oxidation on the titanium oxide layer's properties investigated by spectroscopic methods

    Science.gov (United States)

    Jasinski, J. J.; Kurpaska, L.; Lubas, M.; Lesniak, M.; Jasinski, J.; Sitarz, M.

    2016-12-01

    In this work the study of hybrid Ti Grade 2 during oxidation using FADT - fluidized bed atmospheric diffusive treatment and PVD - magnetron sputtering have been investigated. Additionally, the influence of the oxidation method on the change in the mechanism of oxygen transport to the substrate have been discussed (phenomenon responsible for the improvement of bioactivity). Presented method consists in forming the titanium surface layer saturated with oxygen due to the diffusion and deposition of a thin homogeneous oxide coating on the Ti surface. Discussed processes diminish the surface roughness and increase bio-compatibility of the surface, which results in easier hydroxyapatite cluster deposition. The diffusion process was conducted on Al2O3 fluidized bed, with air as the fluidizing factor at 913 K for 8 h. The deposition of the oxide coatings were carried out with magnetron sputtering, with the use of a TiO2 target at a pressure of 3 × 10-2 mbars and power of 350 W. To evaluate the effects of hybrid oxidation and to determine the mechanism of oxygen transport, the following research methods have been applied: spectroscopy (GDOS, SIMS, RS), microscopic methods (SEM-EDS, SEM-EBSD, TEM-EFTEM), X-ray tests (μ-XRD, GID). Obtained test results were used to identify the type of oxide coatings, to assess the thickness of the layers and to study the influence of crystallographic orientation on oxygen transport and concentration in the surface layer and in the oxide coating. It has been found that the formation of oxide coatings created by using the hybrid method (FADT + PVD leads to a change in oxygen concentration in the substrate due to introduced defects. This phenomenon is in opposition to the conventional methods such as: electrochemical or laser oxidation. In contrast, forming a tight homogeneous oxide coating on Ti surface improves the biocompatibility, which is particularly important in the context of biomedical applications.

  4. Numerical Homogenization of Protective Ceramic Composite Layers using the Hybrid Finite-Discrete Element Methods

    Directory of Open Access Journals (Sweden)

    Zainorizuan Mohd Jaini

    2013-12-01

    Full Text Available Innovative technologies have resulted in more effective ceramic composite as high rate loading-resistance and protective layer. The ceramic composite layer consists of ceramic frontal plate that bonded by softer-strong reinforced polymer network, consequently gains the heterogeneous condition. These materials serve specific purposes of defeating high rate loading and maintaining the structural integrity of the layer. Further due to the lack of a constituent material and tedious problem in heterogonous material modelling, a numerical homogenization is employed to analyse the isotropic material properties of ceramic composite layer in homogenous manner. The objective of this study is to derive a constitutive law of the ceramic composite using the multi-scale analysis. Two-dimensional symmetric macrostructure of the ceramic composite was numerically modelled using the hybrid finite-discrete element method to investigate the effective material properties and strength profile. The macrostructure was modelled as brittle material with nonlinear material properties. The finite element method is incorporated with a Rankine-Rotating Crack approach and discrete element to model the fracture onset. The prescribed uniaxial and biaxial loadings were imposed along the free boundaries to create different deformations. Due to crack initiation on the macrostructure, the averaged stresses were calculated to plot the stress-strain curves and the effective yield stress surface. From the multi-scale analysis, the rate-dependency of Mohr-Coulomb constitutive law was derived for the ceramic composite layer.

  5. Structure of the dayside reconnection layer in resistive MHD and hybrid models

    Science.gov (United States)

    Lin, Y.; Lee, L. C.

    1993-01-01

    Numerical simulations were performed to investigate the structure of the reconnection layer at the dayside magnetopause. Two typical cases are examined in detail; both are asymmetric in magnetic field and plasma density. In case 1, the guide fields in the magnetosheath and in the magnetosphere are set at zero and thus the tangential magnetic fields on the two sides of the initial current sheet are exactly antiparallel. In case 2, the angle between the tangential magnetic fields on the two sides of the initial current sheet is 145 deg. The results obtained from a resistive MHD model and from a hybrid model are found to be different. In the MHD simulation of case 1, a 2-4 intermediate shock is found to bound the reconnection layer on the magnetosheath side, while an Alfven wave pulse bounds the reconnection layer on the magnetospheric side. In case 2, it is found that a time-dependent intermediate shock (TDIS) bounds the reconnection layer on the magnetosheath side, with a slow expansion wave propagating behind. With the MHD simulations, in the general case in which the tangential magnetic fields on the two sides of the initial current sheet are not exactly antiparallel, a rotational discontinuity across which the tangential magnetic field rotates, a large angle is found to bound the reconnection layer on the magnetosheath side.

  6. Healing Temperature of Hybrid Structures Based on Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    赵中伟; 陈志华; 刘红波

    2016-01-01

    The healing temperature of suspen-dome with stacked arches(SDSA)and arch-supported single-layer lattice shell structures was investigated based on the genetic algorithm. The temperature field of arch under solar radiation was derived by FLUENT to investigate the influence of solar radiation on the determination of the healing temperature. Moreover, a multi-scale model was established to apply the complex temperature field under solar radiation. The change in the mechanical response of these two kinds of structures with the healing temperature was discussed. It can be concluded that solar radiation has great influence on the healing temperature, and the genetic algorithm can be effectively used in the optimization of the healing temperature for hybrid structures.

  7. Layer-by-layer assembled multilayer TiO(x) for efficient electron acceptor in polymer hybrid solar cells.

    Science.gov (United States)

    Kang, Hyunbum; Lee, Chanwoo; Yoon, Sung Cheol; Cho, Chul-Hee; Cho, Jinhan; Kim, Bumjoon J

    2010-11-16

    We demonstrate that TiO(x) nanocomposite films fabricated using electrostatic layer-by-layer (LbL) assembly improve the power conversion efficiency of photovoltaic cells compared to conventional TiO(x) films fabricated via the sol-gel process. For this study, titanium precursor/poly(allylamine hydrochloride) (PAH) multilayer films were first deposited onto indium tin oxide-coated glass to produce TiO(x) nanocomposites (TiO(x)NC). The specific effect of the LbL processed TiO(x) on photovoltaic performance was investigated using the planar bilayer TiO(x)NC and highly regioregular poly(3-hexylthiophene) (P3HT) solar cells, and the P3HT/LbL TiO(x)NC solar cells showed a dramatic increase in power efficiency, particularly in terms of the short current density and fill factor. The improved efficiency of this device is mainly due to the difference in the chemical composition of the LbL TiO(x)NC films, including the much higher Ti(3+)/Ti(4+) ratio and the highly reactive facets of crystals as demonstrated by XPS and XRD measurement, thus enhancing the electron transfer between electron donors and acceptors. In addition, the grazing incidence wide-angle X-ray scattering (GIWAXS) study revealed the presence of more highly oriented P3HT stacks parallel to the substrate on the LbL TiO(x)NC film compared to those on the sol-gel TiO(x) films, possibly influencing the hole mobility of P3HT and the energy transfer near and at the interface between the P3HT and TiO(x) layers. The results of this study demonstrate that this approach is a promising one for the design of hybrid solar cells with improved efficiency.

  8. Conformal organic-inorganic hybrid network polymer thin films by molecular layer deposition using trimethylaluminum and glycidol.

    Science.gov (United States)

    Gong, Bo; Peng, Qing; Parsons, Gregory N

    2011-05-19

    Growing interest in nanoscale organic-inorganic hybrid network polymer materials is driving exploration of new bulk and thin film synthesis reaction mechanisms. Molecular layer deposition (MLD) is a vapor-phase deposition process, based on atomic layer deposition (ALD) which proceeds by exposing a surface to an alternating sequence of two or more reactant species, where each surface half-reaction goes to completion before the next reactant exposure. This work describes film growth using trimethyl aluminum and heterobifunctional glycidol at moderate temperatures (90-150 °C), producing a relatively stable organic-inorganic network polymer of the form (-Al-O-(C(4)H(8))-O-)(n). Film growth rate and in situ reaction analysis indicate that film growth does not initially follow a steady-state rate, but increases rapidly during early film growth. The mechanism is consistent with subsurface species transport and trapping, previously documented during MLD and ALD on polymers. A water exposure step after the TMA produces a more linear growth rate, likely by blocking TMA subsurface diffusion. Uniform and conformal films are formed on complex nonplanar substrates. Upon postdeposition annealing, films transform into microporous metal oxides with ∼5 Å pore size and surface area as high as ∼327 m(2)/g, and the resulting structures duplicate the shape of the original substrate. These hybrid films and porous materials could find uses in several research fields including gas separations and diffusion barriers, biomedical scaffolds, high surface area coatings, and others.

  9. Improvement Of Tools Durability By Application Of Hybrid Layer Of Nitrided/PECVD Coating.

    Directory of Open Access Journals (Sweden)

    Gronostajski Z.

    2015-09-01

    Full Text Available In the process of die hot forging the tools are subjected to three main factors leading to their destruction: the intensive thermal shocks, cyclically variable mechanical loads and intensive friction. The above mentioned factors causing destruction in the process of hot forging and warm forging concern mainly the surface of tools. Hybrid technique nitrided/PECVD belong to the latest methods of modifying the properties of the surface layer. In the paper the application of this technique for forging tools of constant velocity joint body is presented. The durability of the new tools is much better than the tools applied so far.

  10. More stable hybrid organic solar cells deposited on amorphous Si electron transfer layer

    Energy Technology Data Exchange (ETDEWEB)

    Samiee, Mehran; Modtland, Brian; Dalal, Vikram L., E-mail: vdalal@iastate.edu [Iowa State University, Dept. of Electrical and Computer Engineering, Ames, Iowa 50011 (United States); Aidarkhanov, Damir [Nazarbayev University, Astana (Kazakhstan)

    2014-05-26

    We report on defect densities, performance, and stability of organic/inorganic hybrid solar cells produced using n-doped inorganic amorphous silicon-carbide layers as the electron transport layer (ETL). The organic material was poly-3-hexyl-thiophene (P3HT) and heterojunction was formed using phenyl-C{sub 71}-Butyric-Acid-Methyl Ester (PCBM). For comparison, inverted solar cells fabricated using Cs{sub 2}CO{sub 3} as ETL were fabricated. Defect densities and subgap quantum efficiency curves were found to be nearly identical for both types of cells. The cells were subjected to 2xsun illumination and it was found that the cells produced using doped a-Si as ETL were much more stable than the cells produced using Cs{sub 2}CO{sub 3}.

  11. Topology optimization of double- and triple-layer grids using a hybrid methodology

    Science.gov (United States)

    Dehghani, M.; Mashayekhi, M.; Salajegheh, E.

    2016-08-01

    In this article, a hybrid methodology combining evolutionary structural optimization (ESO) and gravitational particle swarm (GPS) methods is proposed for topology optimization of double- and triple-layer grids. In the present methodology, which is called the ESO-GPS method, the size optimization of double- and triple-layer grids is first performed by ESO. Then, the outcomes of the ESO are used to improve the GPS through four modifications. Structural weight is minimized against constraints on the displacements of nodes, internal stresses and element slenderness ratio. The GPS is used to investigate the optimum topology of large-scale skeletal structures with discrete variables whose agents update their respective positions by the particle swarm optimization velocity and the acceleration of the gravitational search algorithm. The numerical results show that the proposed algorithm, the ESO-GPS, performs better than the GPS and the other methods presented in the literature.

  12. Genetic algorithm based support vector machine regression in predicting wave transmission of horizontally interlaced multi-layer moored floating pipe breakwater

    Digital Repository Service at National Institute of Oceanography (India)

    Patil, S.G.; Mandal, S.; Hegde, A.V.

    , number of hidden layers and neurons by trial and error, which is time consuming. To overcome the problems inherent in ANN training procedures Jeng et al., [19] adopted the concept of genetic algorithm based training of ANN models, which provided...-fuzzy inference system (ANFIS), which is a five-layer feed-forward neural network, which includes fuzzification layer, rule layer, normalization layer, defuzzification layer and a single summation neuron . It is a hybrid neuro-fuzzy technique that brings...

  13. An Application of CFD to Guide Forced Boundary-Layer Transition for Low-Speed Tests of a Hybrid Wing-Body Configuration

    Science.gov (United States)

    Luckring, James M.; Deere, Karen A.; Childs, Robert E.; Stremel, Paul M.; Long, Kurtis R.

    2016-01-01

    A hybrid transition trip-dot sizing and placement test technique was developed in support of recent experimental research on a hybrid wing-body configuration under study for the NASA Environmentally Responsible Aviation project. The approach combines traditional methods with Computational Fluid Dynamics. The application had three-dimensional boundary layers that were simulated with either fully turbulent or transitional flow models using established Reynolds-Averaged Navier-Stokes methods. Trip strip effectiveness was verified experimentally using infrared thermography during a low-speed wind tunnel test. Although the work was performed on one specific configuration, the process was based on fundamental flow physics and could be applicable to other configurations.

  14. Three-Dimensional Printing Based Hybrid Manufacturing of Microfluidic Devices.

    Science.gov (United States)

    Alapan, Yunus; Hasan, Muhammad Noman; Shen, Richang; Gurkan, Umut A

    2015-05-01

    Microfluidic platforms offer revolutionary and practical solutions to challenging problems in biology and medicine. Even though traditional micro/nanofabrication technologies expedited the emergence of the microfluidics field, recent advances in advanced additive manufacturing hold significant potential for single-step, stand-alone microfluidic device fabrication. One such technology, which holds a significant promise for next generation microsystem fabrication is three-dimensional (3D) printing. Presently, building 3D printed stand-alone microfluidic devices with fully embedded microchannels for applications in biology and medicine has the following challenges: (i) limitations in achievable design complexity, (ii) need for a wider variety of transparent materials, (iii) limited z-resolution, (iv) absence of extremely smooth surface finish, and (v) limitations in precision fabrication of hollow and void sections with extremely high surface area to volume ratio. We developed a new way to fabricate stand-alone microfluidic devices with integrated manifolds and embedded microchannels by utilizing a 3D printing and laser micromachined lamination based hybrid manufacturing approach. In this new fabrication method, we exploit the minimized fabrication steps enabled by 3D printing, and reduced assembly complexities facilitated by laser micromachined lamination method. The new hybrid fabrication method enables key features for advanced microfluidic system architecture: (i) increased design complexity in 3D, (ii) improved control over microflow behavior in all three directions and in multiple layers, (iii) transverse multilayer flow and precisely integrated flow distribution, and (iv) enhanced transparency for high resolution imaging and analysis. Hybrid manufacturing approaches hold great potential in advancing microfluidic device fabrication in terms of standardization, fast production, and user-independent manufacturing.

  15. Engineering of a polymer layered bio-hybrid heart valve scaffold.

    Science.gov (United States)

    Jahnavi, S; Kumary, T V; Bhuvaneshwar, G S; Natarajan, T S; Verma, R S

    2015-06-01

    Current treatment strategy for end stage valve disease involves either valvular repair or replacement with homograft/mechanical/bioprosthetic valves. In cases of recurrent stenosis/ regurgitation, valve replacement is preferred choice of treatment over valvular repair. Currently available mechanical valves primarily provide durability whereas bioprosthetic valves have superior tissue compatibility but both lack remodelling and regenerative properties making their utility limited in paediatric patients. With advances in tissue engineering, attempts have been made to fabricate valves with regenerative potential using various polymers, decellularized tissues and hybrid scaffolds. To engineer an ideal heart valve, decellularized bovine pericardium extracellular matrix (DBPECM) is an attractive biocompatible scaffold but has weak mechanical properties and rapid degradation. However, DBPECM can be modified with synthetic polymers to enhance its mechanical properties. In this study, we developed a Bio-Hybrid scaffold with non-cross linked DBPECM in its native structure coated with a layer of Polycaprolactone-Chitosan (PCL-CH) nanofibers that displayed superior mechanical properties. Surface and functional studies demonstrated integration of PCL-CH to the DBPECM with enhanced bio and hemocompatibility. This engineered Bio-Hybrid scaffold exhibited most of the physical, biochemical and functional properties of the native valve that makes it an ideal scaffold for fabrication of cardiac valve with regenerative potential.

  16. Layered Double Hydroxide Modified by PEGylated Hyaluronic Acid as a Hybrid Nanocarrier for Targeted Drug Delivery

    Institute of Scientific and Technical Information of China (English)

    董岸杰; 李雪; 王伟伟; 韩尚聪; 刘鉴锋; 刘金剑; 赵军强; 许舒欣; 邓联东

    2016-01-01

    In recent years, organic-inorganic hybrid nanocarriers are explored for effective drug delivery and pref-erable disease treatments. In this study, using 5-fluorouracil(5-FU)as electronegative model drug, a new type of organic-inorganic hybrid drug delivery system(LDH/HA-PEG/5-FU)was conceived and manufactured by the ad-sorption of PEGylated hyaluronic acid(HA-PEG)on the surface of layered double hydroxide(LDH, prepared via hydrothermal method)and the intercalation of 5-FU in the interlamination of LDH via ion exchange strategy. The drug loading amount of LDH/HA-PEG/5-FU achieved as high as 34.2%. LDH, LDH/5-FU and LDH/HA-PEG/5-FU were characterized by FT-IR, XRD, TGA, laser particle size analyzer and SEM. With the benefit of pH-degradable feature of LDH and enzyme-degradable feature of HA, LDH/HA-PEG/5-FU showed pH-degradable and enzyme-degradable capacity inin vitro drug release. Moreover, the drug carrier LDH/HA-PEG contained biocom-patible PEG and tumor-targeted HA, resulting in lower cytotoxicity and better endocytosis compared with LDHin vitro. It was suggested that the organic-inorganic hybrid drug delivery system, which was endowed with the proper-ties of controlled release, low toxicity and tumor-targeting delivery for ameliorative cancer therapy, was advisable and might be applied further to fulfill other treatments.

  17. Nanocrystal-based hybrid white light generation with tunable colour parameters

    Science.gov (United States)

    Nizamoglu, S.; Demir, H. V.

    2007-09-01

    We present the hybridization of CdSe/ZnS core shell nanocrystals (NCs) on InGaN/GaN based blue/near-UV LEDs to generate light widely tunable across the visible spectral range and especially within the white region of the CIE (1931) chromaticity diagram. We report on the design, growth, fabrication and characterization of these hybrid NC-LEDs. In 26 NC-LED samples, we experimentally show the effect of the NC concentration and NC film thickness on tuning the colour properties of the generated light (tristimulus coordinates, colour rendering index and correlated temperature) and further compare layer by layer assembly and blending of NCs for integration in LEDs. With greatly tunable colour properties, these hybrid white light sources hold promise for future lighting and display applications.

  18. In Situ Hybridization of Pulp Fibers Using Mg-Al Layered Double Hydroxides

    Directory of Open Access Journals (Sweden)

    Carl-Erik Lange

    2015-04-01

    Full Text Available Inorganic Mg2+ and Al3+ containing layered double hydroxide (LDH particles were synthesised in situ from aqueous solution onto chemical pulp fibers of pine (Pinus sylvestris. High super saturated (hss solution with sodium carbonate produced LDH particles with an average diameter of 100–200 nm. Nano-size (70 nm LDH particles were found from fibers external surface and, to a lesser degree, from the S2 cell wall after synthesis via low super saturated (lss route. The synthesis via slow urea hydrolysis (Uhyd yielded micron and clay sized LDH (2–5 μm and enabled efficient fiber densification via mineralization of S2 fiber wall layer as indicated by TEM and compliance analysis. The Uhyd method decreased fiber compliance up to 50%. Reduction in the polymerisation degree of cellulose was observed with capillary viscometry. Thermogravimetric analysis showed that the hybridization with LDH reduced the exothermic heat, indicating, that this material can be incorporated in flame retardant applications. Fiber charge was assessed by Fibers 2015, 3 104 adsorption expermients with methylene blue (MB and metanil yellow (MY. Synthesis via lss route retained most of the fibres original charge and provided the highest capacity (10 μmol/g for anionic MY, indicating cationic character of hybrid fibers. Our results suggested that mineralized fibers can be potentially used in advanced applications such as biocomposites and adsorbent materials.

  19. New hybrid lead iodides: From one-dimensional chain to two-dimensional layered perovskite structure

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Kecai; Liu, Wei [Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 (United States); Teat, Simon J. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); An, Litao; Wang, Hao; Emge, Thomas J. [Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 (United States); Li, Jing, E-mail: jingli@rutgers.edu [Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 (United States)

    2015-10-15

    Two new hybrid lead halides (H{sub 2}BDA)[PbI{sub 4}] (1) (H{sub 2}BDA=1,4-butanediammonium dication) and (HNPEIM)[PbI{sub 3}] (2) (HNPEIM=N-​phenyl-ethanimidamidine cation) have been synthesized and structurally characterized. X-ray diffraction analyses reveal that compound 1 features a two-dimensional corner-sharing perovskite layer whereas compound 2 contains one-dimensional edge-sharing double chains. The N-​phenyl-ethanimidamidine cation within compound 2 was generated in-situ under solvothermal conditions. The optical absorption spectra collected at room temperature suggest that both compounds are semiconductors having direct band gaps, with estimated values of 2.64 and 2.73 eV for 1 and 2, respectively. Results from the density functional theory (DFT) calculations are consistent with the experimental data. Density of states (DOS) analysis reveals that in both compounds 1 and 2, the energy states in the valence band maximum region are iodine 5p atomic orbitals with a small contribution from lead 6s, while in the region of conduction band minimum, the major contributions are from the inorganic (Pb 6p atomic orbitals) and organic components (C and N 2p atomic orbitals) in compound 1 and 2, respectively. - Graphical abstract: Two new hybrid lead halides built on one-dimensional edge-sharing double chains and two-dimensional corner-sharing perovskite layers are synthesized and their structural and electronic properties are analyzed. - Highlights: • Two new hybrid lead iodides are designed, synthesized, and characterized. • They are closely related to, but different from, perovskite structures. • The electronic properties of both compounds are analyzed by DFT calculations.

  20. Engineering of a polymer layered bio-hybrid heart valve scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Jahnavi, S., E-mail: jani84@gmail.com [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, TN (India); Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Kumary, T.V., E-mail: tvkumary@yahoo.com [Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Bhuvaneshwar, G.S., E-mail: gs.bhuvnesh@gmail.com [Trivitron Innovation Centre, Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, TN (India); Natarajan, T.S., E-mail: tsniit@gmail.com [Conducting Polymer laboratory, Department of Physics, Indian Institute of Technology, Madras, Chennai 600036, TN (India); Verma, R.S., E-mail: vermars@iitm.ac.in [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, TN (India)

    2015-06-01

    Current treatment strategy for end stage valve disease involves either valvular repair or replacement with homograft/mechanical/bioprosthetic valves. In cases of recurrent stenosis/ regurgitation, valve replacement is preferred choice of treatment over valvular repair. Currently available mechanical valves primarily provide durability whereas bioprosthetic valves have superior tissue compatibility but both lack remodelling and regenerative properties making their utility limited in paediatric patients. With advances in tissue engineering, attempts have been made to fabricate valves with regenerative potential using various polymers, decellularized tissues and hybrid scaffolds. To engineer an ideal heart valve, decellularized bovine pericardium extracellular matrix (DBPECM) is an attractive biocompatible scaffold but has weak mechanical properties and rapid degradation. However, DBPECM can be modified with synthetic polymers to enhance its mechanical properties. In this study, we developed a Bio-Hybrid scaffold with non-cross linked DBPECM in its native structure coated with a layer of Polycaprolactone-Chitosan (PCL-CH) nanofibers that displayed superior mechanical properties. Surface and functional studies demonstrated integration of PCL-CH to the DBPECM with enhanced bio and hemocompatibility. This engineered Bio-Hybrid scaffold exhibited most of the physical, biochemical and functional properties of the native valve that makes it an ideal scaffold for fabrication of cardiac valve with regenerative potential. - Highlights: • A Bio-Hybrid scaffold was fabricated with PCL-CH blend and DBPECM. • PCL-CH functionally interacted with decellularized matrix without cross linking. • Modified scaffold exhibited mechanical properties similar to native heart valve. • Supported better fibroblast and endothelial cell adhesion and proliferation. • The developed scaffold can be utilized for tissue engineering of heart valve.

  1. Intermediate layer, microstructure and mechanical properties of aluminum alloy/stainless steel butt joint using laser-MIG hybrid welding-brazing method

    Science.gov (United States)

    Zhu, Zongtao; Wan, Zhandong; Li, Yuanxing; Xue, Junyu; Hui, Chen

    2017-07-01

    Butt joining of AA6061 aluminum (Al) alloy and 304 stainless steel of 2-mm thickness was conducted using laser-MIG hybrid welding-brazing method with ER4043 filler metal. To promote the mechanical properties of the welding-brazing joints, two kinds of intermediate layers (Al-Si-Mg alloy and Ag-based alloy) are used to adjust the microstructures of the joints. The brazing interface and the tensile strength of the joints were characterized. The results showed that the brazing interface between Al alloy and stainless steel consisted of double layers of Fe2Al5 (near stainless steel) and Fe4Al13 intermetallic compounds (IMCs) with a total thickness of 3.7 μm, when using Al-Si-Mg alloy as the intermediate layer. The brazing interface of the joints using Ag-based alloy as intermediate layer also consists of double IMC layers, but the first layer near stainless steel was FeAl2 and the total thickness of these two IMC layers decreased to 3.1 μm. The tensile strength of the joints using Al-Si-Mg alloy as the intermediate layer was promoted to 149 MPa, which was 63 MPa higher than that of the joints using Al-Si-Mg alloy as the intermediate layer. The fractures occurred in the brazing interface between Al alloy and stainless steel.

  2. Fuel decomposition and boundary-layer combustion processes of hybrid rocket motors

    Science.gov (United States)

    Chiaverini, Martin J.; Harting, George C.; Lu, Yeu-Cherng; Kuo, Kenneth K.; Serin, Nadir; Johnson, David K.

    1995-01-01

    Using a high-pressure, two-dimensional hybrid motor, an experimental investigation was conducted on fundamental processes involved in hybrid rocket combustion. HTPB (Hydroxyl-terminated Polybutadiene) fuel cross-linked with diisocyanate was burned with GOX under various operating conditions. Large-amplitude pressure oscillations were encountered in earlier test runs. After identifying the source of instability and decoupling the GOX feed-line system and combustion chamber, the pressure oscillations were drastically reduced from +/-20% of the localized mean pressure to an acceptable range of +/-1.5% Embedded fine-wire thermocouples indicated that the surface temperature of the burning fuel was around 1000 K depending upon axial locations and operating conditions. Also, except near the leading-edge region, the subsurface thermal wave profiles in the upstream locations are thicker than those in the downstream locations since the solid-fuel regression rate, in general, increases with distance along the fuel slab. The recovered solid fuel slabs in the laminar portion of the boundary layer exhibited smooth surfaces, indicating the existence of a liquid melt layer on the burning fuel surface in the upstream region. After the transition section, which displayed distinct transverse striations, the surface roughness pattern became quite random and very pronounced in the downstream turbulent boundary-layer region. Both real-time X-ray radiography and ultrasonic pulse-echo techniques were used to determine the instantaneous web thickness burned and instantaneous solid-fuel regression rates over certain portions of the fuel slabs. Globally averaged and axially dependent but time-averaged regression rates were also obtained and presented.

  3. Composite Layers “MgAl Intermetalic Layer / PVD Coating” Obtained On The AZ91D Magnesium Alloy By Different Hybrid Surface Treatment Methods

    Directory of Open Access Journals (Sweden)

    Smolik J.

    2015-06-01

    Full Text Available Magnesium alloys have very interesting physical properties which make them ‘materials of the future’ for tools and machine components in many industry areas. However, very low corrosion and tribological resistance of magnesium alloys hampers the implementation of this material in the industry. One of the methods to improve the properties of magnesium alloys is the application of the solutions of surface engineering like hybrid technologies. In this paper, the authors compare the tribological and corrosion properties of two types of “MgAlitermetalic / PVD coating” composite layers obtained by two different hybrid surface treatment technologies. In the first configuration, the “MgAlitermetalic / PVD coating” composite layer was obtained by multisource hybrid surface treatment technology combining magnetron sputtering (MS, arc evaporation (AE and vacuum heating methods. The second type of a composite layer was prepared using a hybrid technology combined with a diffusion treatment process in Al-powder and the electron beam evaporation (EB method. The authors conclude, that even though the application of „MgAlitermetalic / PVD coating” composite layers can be an effective solution to increase the abrasive wear resistance of magnesium alloys, it is not a good solution to increase its corrosion resistance.

  4. Research of IDSS Architecture Based on Hybrid Systems

    Institute of Scientific and Technical Information of China (English)

    MA Biao; YANG Bao-an

    2005-01-01

    This paper discusses the necessity of building IDSS on hybrid systems, and adopts XML technology to manage isomeric knowledge in hybrid systems. The paper proposes a new architecture of hybrid systems based IDSS whose core system is isomeric knowledge system. The architecture is composed of knowledge component, problems processing system, data component and intelligent user interface. This new architecture aims to enhance the capability of integrating hybrid systems, to improve the supporting effectiveness of decision-making and the intelligent level of IDSS, and tries a new way to elevate the system's ability of handling and learning knowledge.

  5. Layer-by-layer self-assembled mesoporous PEDOT-PSS and carbon black hybrid films for platinum free dye-sensitized-solar-cell counter electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Koji; Shiratori, Seimei [School of Integrated Design Engineering, Keio University, Yokohama 223-8522 (Japan)

    2011-05-13

    A thin film of poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulfonic acid) (PEDOT-PSS), which is an alternative cathodic catalyst for Pt in dye-sensitized solar cells, was prepared using the layer-by-layer self-assembly method (LbL). The film is highly adhesive to the substrate and has a controllable thickness. Therefore, the PEDOT-PSS film prepared using LbL is expected have high performance and durability as a counter electrode. Moreover, when carbon black was added to the PEDOT-PSS solution, highly mesoporous PEDOT-PSS and carbon black hybrid films were obtained. These films showed high cathodic activity. In this study, we investigated the change in morphology in the obtained film with increasing carbon black content, and the influence of the porosity and thickness on the performance of the cells. In this study, a Pt-free counter electrode with performance similar to that of Pt-based counter electrodes was successfully fabricated. The achieved efficiency of 4.71% was only a factor of 8% lower than that of the cell using conventional thermally deposited Pt on fluorine-doped tin oxide glass counter electrodes.

  6. Layer-by-layer self-assembled mesoporous PEDOT-PSS and carbon black hybrid films for platinum free dye-sensitized-solar-cell counter electrodes.

    Science.gov (United States)

    Kitamura, Koji; Shiratori, Seimei

    2011-05-13

    A thin film of poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulfonic acid) (PEDOT-PSS), which is an alternative cathodic catalyst for Pt in dye-sensitized solar cells, was prepared using the layer-by-layer self-assembly method (LbL). The film is highly adhesive to the substrate and has a controllable thickness. Therefore, the PEDOT-PSS film prepared using LbL is expected have high performance and durability as a counter electrode. Moreover, when carbon black was added to the PEDOT-PSS solution, highly mesoporous PEDOT-PSS and carbon black hybrid films were obtained. These films showed high cathodic activity. In this study, we investigated the change in morphology in the obtained film with increasing carbon black content, and the influence of the porosity and thickness on the performance of the cells. In this study, a Pt-free counter electrode with performance similar to that of Pt-based counter electrodes was successfully fabricated. The achieved efficiency of 4.71% was only a factor of 8% lower than that of the cell using conventional thermally deposited Pt on fluorine-doped tin oxide glass counter electrodes.

  7. Enabling Realistic Cross-Layer Analysis based on Satellite Physical Layer Traces

    CERN Document Server

    Kuhn, Nicolas; Lacan, Jerome; Boreli, Roksana; Bes, Caroline; Clarac, Laurence

    2012-01-01

    We present a solution to evaluate the performance of transport protocols as a function of link layer reliability schemes (i.e. ARQ, FEC and Hybrid ARQ) applied to satellite physical layer traces. As modelling such traces is complex and may require approximations, the use of real traces will minimise the potential for erroneous performance evaluations resulting from imperfect models. Our Trace Manager Tool (TMT) produces the corresponding link layer output, which is then used within the ns-2 network simulator via the additionally developed ns-2 interface module. We first present the analytical models for the link layer with bursty erasure packets and for the link layer reliability mechanisms with bursty erasures. Then, we present details of the TMT tool and our validation methodology, demonstrating that the selected performance metrics (recovery delay and throughput efficiency) exhibit a good match between the theoretical results and those obtained with TMT. Finally, we present results showing the impact of di...

  8. A Novel Degradation Estimation Method for a Hybrid Energy Storage System Consisting of Battery and Double-Layer Capacitor

    OpenAIRE

    Yuanbin Yu; Dongdong Zhang; Haitao Min; Yi Tang; Tao Zhu(GCAP-CASPER, Physics Department, Baylor University, One Bear Place, # 97316, Waco, TX 76798-7316, U.S.A.)

    2016-01-01

    This paper presents a new method for battery degradation estimation using a power-energy (PE) function in a battery/ultracapacitor hybrid energy storage system (HESS), and the integrated optimization which concerns both parameters matching and control for HESS has been done as well. A semiactive topology of HESS with double-layer capacitor (EDLC) coupled directly with DC-link is adopted for a hybrid electric city bus (HECB). In the purpose of presenting the quantitative relationship between s...

  9. Study of MEH–PPV/PCBM active layer morphology and its application for hybrid solar cell performance

    Indian Academy of Sciences (India)

    Quynh Nhu Nguyen Truong; Nguyen Tam Nguyen Truong; Chinho Park; Jae Hak Jung

    2012-04-01

    Surface morphologies of MEH–PPV:PCBM active layers were optimized by investigating ITO substrate treated with oxygen and nitrogen plasma. This treatment effectively improved smoothness, transmittance, and contact angle of ITO’s, resulting in good anode contacts for hybrid device structures. The consistently improved performance of hybrid solar cells was also achieved. The surface properties of treated and untreated ITO substrates were compared by contact angle, four point probe, scanning electron microscopy, and atomic force microscopy.

  10. Hybrid LSA-ANN Based Home Energy Management Scheduling Controller for Residential Demand Response Strategy

    Directory of Open Access Journals (Sweden)

    Maytham S. Ahmed

    2016-09-01

    Full Text Available Demand response (DR program can shift peak time load to off-peak time, thereby reducing greenhouse gas emissions and allowing energy conservation. In this study, the home energy management scheduling controller of the residential DR strategy is proposed using the hybrid lightning search algorithm (LSA-based artificial neural network (ANN to predict the optimal ON/OFF status for home appliances. Consequently, the scheduled operation of several appliances is improved in terms of cost savings. In the proposed approach, a set of the most common residential appliances are modeled, and their activation is controlled by the hybrid LSA-ANN based home energy management scheduling controller. Four appliances, namely, air conditioner, water heater, refrigerator, and washing machine (WM, are developed by Matlab/Simulink according to customer preferences and priority of appliances. The ANN controller has to be tuned properly using suitable learning rate value and number of nodes in the hidden layers to schedule the appliances optimally. Given that finding proper ANN tuning parameters is difficult, the LSA optimization is hybridized with ANN to improve the ANN performances by selecting the optimum values of neurons in each hidden layer and learning rate. Therefore, the ON/OFF estimation accuracy by ANN can be improved. Results of the hybrid LSA-ANN are compared with those of hybrid particle swarm optimization (PSO based ANN to validate the developed algorithm. Results show that the hybrid LSA-ANN outperforms the hybrid PSO based ANN. The proposed scheduling algorithm can significantly reduce the peak-hour energy consumption during the DR event by up to 9.7138% considering four appliances per 7-h period.

  11. Carbon nanotube based hybrid nanocarbon foam

    Science.gov (United States)

    Shahrizan Jamal, M.; Zhang, Mei

    2017-03-01

    Carbon nanotube (CNT) based nanocarbon foams (NFs) and the hybrid nanocarbon foams (HNFs) are fabricated in this work. The NFs are formed by using poly(methyl methacrylate) microspheres as a template to create micro-scaled pores. The cell walls are made of CNT networks with nano-scaled pores. The interconnections among CNTs are secured using graphene and nanographite generated via carbonization of polyacrylonitrile. The resulting NFs are ultra-lightweight, highly elastic, electrically and thermally conductive, and robust in structure. The HNFs are made by infiltrating thermoplastic polymer into the NFs in a controllable procedure. Compared to NFs, the HNFs have much higher strength, same electrical conductivity, and limited increase in density. The compressive strength of the HNF increased more than 50 times while the density was changed less than 10 times due to the polymer infiltration. It is found that the deformed HNFs can recover in both structure and property when they are heated over the glass transition temperature of the infiltrated polymer. Such remarkable healing capability could broaden the applications of the HNFs.

  12. Design, analysis and modeling of a novel hybrid powertrain system based on hybridized automated manual transmission

    Science.gov (United States)

    Wu, Guang; Dong, Zuomin

    2017-09-01

    Hybrid electric vehicles are widely accepted as a promising short to mid-term technical solution due to noticeably improved efficiency and lower emissions at competitive costs. In recent years, various hybrid powertrain systems were proposed and implemented based on different types of conventional transmission. Power-split system, including Toyota Hybrid System and Ford Hybrid System, are well-known examples. However, their relatively low torque capacity, and the drive of alternative and more advanced designs encouraged other innovative hybrid system designs. In this work, a new type of hybrid powertrain system based hybridized automated manual transmission (HAMT) is proposed. By using the concept of torque gap filler (TGF), this new hybrid powertrain type has the potential to overcome issue of torque gap during gearshift. The HAMT design (patent pending) is described in details, from gear layout and design of gear ratios (EV mode and HEV mode) to torque paths at different gears. As an analytical tool, mutli-body model of vehicle equipped with this HAMT was built to analyze powertrain dynamics at various steady and transient modes. A gearshift was decomposed and analyzed based basic modes. Furthermore, a Simulink-SimDriveline hybrid vehicle model was built for the new transmission, driveline and vehicle modular. Control strategy has also been built to harmonically coordinate different powertrain components to realize TGF function. A vehicle launch simulation test has been completed under 30% of accelerator pedal position to reveal details during gearshift. Simulation results showed that this HAMT can eliminate most torque gap that has been persistent issue of traditional AMT, improving both drivability and performance. This work demonstrated a new type of transmission that features high torque capacity, high efficiency and improved drivability.

  13. New MPPT algorithm based on hybrid dynamical theory

    KAUST Repository

    Elmetennani, Shahrazed

    2014-11-01

    This paper presents a new maximum power point tracking algorithm based on the hybrid dynamical theory. A multiceli converter has been considered as an adaptation stage for the photovoltaic chain. The proposed algorithm is a hybrid automata switching between eight different operating modes, which has been validated by simulation tests under different working conditions. © 2014 IEEE.

  14. 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.

  15. PMMA–SiO{sub 2} hybrid films as gate dielectric for ZnO based thin-film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Acosta, M.D. [Centro de Investigación y de Estudios Avanzados del IPN, Unidad Querétaro, Apdo. Postal 1-798, Querétaro, Qro. 76001 (Mexico); Quevedo-López, M.A. [Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, TX 75083 (United States); Ramírez-Bon, R., E-mail: rrbon@qro.cinvestav.mx [Centro de Investigación y de Estudios Avanzados del IPN, Unidad Querétaro, Apdo. Postal 1-798, Querétaro, Qro. 76001 (Mexico)

    2014-08-01

    In this paper we report a low temperature sol–gel deposition process of PMMA–SiO{sub 2} hybrid films, with variable dielectric properties depending on the composition of the precursor solution, for applications to gate dielectric layers in field-effect thin film transistors (FE-TFT). The hybrid layers were processed by a modified sol–gel route using as precursors Tetraethyl orthosilicate (TEOS) and Methyl methacrylate (MMA), and 3-(Trimethoxysilyl)propyl methacrylate (TMSPM) as the coupling agent. Three types of hybrid films were processed with molar ratios of the precursors in the initial solution 1.0: 0.25, 0.50, 0.75: 1.0 for TEOS: TMSPM: MMA, respectively. The hybrid films were deposited by spin coating of the hybrid precursor solutions onto p-type Si (100) substrates and heat-treated at 90 °C for 24 h. The chemical bonding in the hybrid films was analyzed by Fourier Transform Infrared Spectroscopy to confirm their hybrid nature. The refractive index of the hybrid films as a function of the TMSPM coupling agent concentration, were determined from a simultaneous analysis of optical reflectance and spectroscopic ellipsometry experimental data. The PMMA–SiO{sub 2} hybrid films were studied as dielectric films using metal-insulator-metal structures. Capacitance–Voltage (C–V) and current–voltage (I–V) electrical methods were used to extract the dielectric properties of the different hybrid layers. The three types of hybrid films were tested as gate dielectric layers in thin film transistors with structure ZnO/PMMA–SiO{sub 2}/p-Si with a common bottom gate and patterned Al source/drain contacts, with different channel lengths. We analyzed the output electrical responses of the ZnO-based TFTs to determine their performance parameters as a function of channel length and hybrid gate dielectric layer. - Highlights: • PMMA–SiO{sub 2} hybrid films as dielectric material synthesized by sol–gel process at low temperature. • PMMA–SiO{sub 2

  16. Fabrication, characterization and application of Cu{sub 2}ZnSn(S,Se){sub 4} absorber layer via a hybrid ink containing ball milled powders

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chunran [State Key Laboratory of Superhard Materials and College of Physics, Jilin University, Changchun 130023 (China); Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); College of Mathematics and Physics, Bohai University, Jinzhou 121013 (China); Yao, Bin, E-mail: binyao@jlu.edu.cn [State Key Laboratory of Superhard Materials and College of Physics, Jilin University, Changchun 130023 (China); Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); Li, Yongfeng, E-mail: liyongfeng@jlu.edu.cn [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); Xiao, Zhenyu [State Key Laboratory of Superhard Materials and College of Physics, Jilin University, Changchun 130023 (China); Ding, Zhanhui [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); Zhao, Haifeng; Zhang, Ligong; Zhang, Zhenzhong [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, No. 3888 Dongnanhu Road, Changchun 130033 (China)

    2015-09-15

    Highlights: • CZTS powders are prepared from binary sulfides by a low cost ball milling process. • Elaborated on phase evolution and formation mechanism of CZTS. • Proposed a hybrid ink approach to resolve difficulty in deposition of CZTS film. • CZTSSe solar cells with highest efficiency of 4.2% are fabricated. • Small-grained CZTS layer hinders the collection of minority carriers. - Abstract: Cu{sub 2}ZnSnS{sub 4} (CZTS) powder with kesterite structure was prepared by ball milling of mixture of Cu{sub 2}S, ZnS and SnS{sub 2} powders for more than 15 h. By dispersing the milled CZTS powder in a Cu-, Zn- and Sn-chalcogenide precursor solution, a hybrid ink was fabricated. With the hybrid ink, a precursor CZTS film was deposited on Mo coated soda-lime glass by spin-coating. In order to obtain Cu{sub 2}ZnSn(S,Se){sub 4} (CZTSSe) absorber film with kesterite structure, the CZTS film was annealed at 560 °C for 15 min in Se ambient. It is demonstrated that the annealed film is dominated by a thick layer of kesterite CZTSSe with larger grain size and Cu{sub 8}Fe{sub 3}Sn{sub 2}(S,Se){sub 12} impurity phase with the exception of a very thin layer of kesterite CZTS with smaller grain size at interface between the CZTSSe and Mo layers. Solar cell device was fabricated by using the annealed CZTSSe film as absorber layer, and its conversion efficiency reached 4.2%. Mechanism of formation of the kesterite CZTS powder and CZTSSe film as well as effect of impurity phases on conversion efficiency are discussed in the present paper. The present results suggest that the hybrid ink approach combining with ball milling is a simple, low cost and promising method for preparation of kesterite CZTSSe absorber film and CZTSSe-based solar cell.

  17. Bipolar resistive switching properties of Ti-CuO/(hexafluoro-hexa-peri-hexabenzocoronene)-Cu hybrid interface device: Influence of electronic nature of organic layer

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Bharti; Mehta, B. R.; Varandani, Deepak [Thin Film Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Govind [Surface Physics Group, National Physical Laboratory (CSIR), New Delhi-110012 (India); Narita, A.; Feng, X.; Muellen, K. [Max-Planck Institute for Polymer Research, D-55128 Mainz (Germany)

    2013-05-28

    This study reports the change in the structural and junction properties of Ti-CuO-Cu structure on incorporation of a 2-dimensional (2D) organic layer comprising of n-type hexafluoro-hexa-peri-hexabenzocoronene (6F-HBC). A bipolar resistive switching is observed in the device having interface between sputter deposited copper oxide (CuO) and vacuum sublimated 6F-HBC hybrid interface. The CuO/6F-HBC hybrid interface exhibits rectifying I-V characteristics in complete contrast to the ohmic and rectifying characteristics of junctions based on individual 6F-HBC and CuO layers. Large change in resistive switching property from unipolar resistive switching in CuO/HBC to bipolar resistive switching in CuO/6F-HBC interface was observed. At the CuO/6F-HBC interface, C1s peak corresponding to fluorinated carbon is shifted by 0.68 eV towards higher binding energy (BE) side and O1s peak due to non-lattice oxygen is shifted by 0.6 eV towards lower BE, confirming the interaction of O{sup 2-} ion in CuO with fluorinated carbon atoms in 6F-HBC at the hybrid interface. Correlation between conductive atomic force microscopy images and atomic force microscopy topography images, I-V characteristics in conducting, non-conducting, and pristine regions along with x-ray photoelectron spectroscopy results establishes the important role of hybrid interface to determining the resistive switching properties. This study demonstrates that the resistive switching and interface properties of a hybrid device based on inorganic and organic 2D materials can be modified by changing the electronic properties of organic layer by attaching suitable functional groups.

  18. High Performance Hybrid Two Layer Router Architecture for FPGAs Using Network On Chip

    CERN Document Server

    Ezhumalai, P; Arun, C; Sakthivel, P; Sridharan, D

    2010-01-01

    Networks on Chip is a recent solution paradigm adopted to increase the performance of Multicore designs. The key idea is to interconnect various computation modules (IP cores) in a network fashion and transport packets simultaneously across them, thereby gaining performance. In addition to improving performance by having multiple packets in flight, NoCs also present a host of other advantages including scalability, power efficiency, and component reuse through modular design. This work focuses on design and development of high performance communication architectures for FPGAs using NoCs Once completely developed, the above methodology could be used to augment the current FPGA design flow for implementing multicore SoC applications. We design and implement an NoC framework for FPGAs, MultiClock OnChip Network for Reconfigurable Systems (MoCReS). We propose a novel microarchitecture for a hybrid two layer router that supports both packetswitched communications, across its local and directional ports, as well as...

  19. Bonding and bio-properties of hybrid laser/magnetron Cr-enriched DLC layers

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, Miroslav, E-mail: jelinek@fzu.cz [Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, nam. Sitna 3105, 27201 Kladno (Czech Republic); Zemek, Josef [Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague (Czech Republic); Vandrovcová, Marta; Bačáková, Lucie [Institute of Physiology of the Czech Academy of Sciences of the Czech Republic, v.v.i., Videnska 1083, 14220 Prague 4 (Czech Republic); Kocourek, Tomáš; Remsa, Jan; Písařík, Petr [Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Na Slovance 2, 18221 Prague (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, nam. Sitna 3105, 27201 Kladno (Czech Republic)

    2016-01-01

    Chromium-enriched diamond-like carbon (DLC) layers were prepared by a hybrid technology using a combination of pulsed laser deposition (PLD) and magnetron sputtering. XRD revealed no chromium peaks, indicating that the layers are mostly amorphous. Carbon (sp{sup 2} and sp{sup 3} bonds) and chromium bonds were determined by XPS from C 1s, O 1s, and Cr 2p photoelectron peaks. Depending on the deposition conditions, the concentration of Cr in DLC layers moved from zero to 10 at.% for as-received sample surfaces, and to about 31 at.% after mild sputter-cleaning by argon ion cluster beam. It should be noted that the most stable Cr{sup 3+} bonding state is in Cr{sub 2}O{sub 3} and Cr(OH){sub 3}, and that there is the toxic Cr{sup 6+} state in CrO{sub 3}. The surface content of hexavalent chromium in the Cr 2p3/2 spectra is rather low, but discernible. The population density of Saos-2 cells was the highest in samples containing higher concentrations of chromium 7.7 and 10 at.%. This means that higher concentrations of chromium supported the cell adhesion and proliferation. In addition, as revealed by a LIVE/DEAD viability/cytotoxicity kit, the cells on all Cr-containing samples maintained high viability (96 to 99%) on days 1 and 3 after seeding. However, this seemingly positive cell behavior could be associated with the risk of dedifferentiation and oncogenic transformation of cells. - Highlights: • DLC and chromium-enriched DLC layers were prepared by hybrid laser–magnetron deposition. • The content of chromium in DLC varied up to 10 at.% (31 at.% after ion beam sputtering). • The surface content of toxic hexavalent chromium in the Cr 2p3/2 spectra is rather low but discernible. • Higher concentrations of chromium supported the cell adhesion and proliferation. • Cells on all Cr-containing samples maintained high viability (96 to 99%).

  20. Thermoelectric properties of layered calcium cobaltite Ca3Co4O9 from hybrid functional first-principles calculations

    Science.gov (United States)

    Lemal, Sébastien; Varignon, Julien; Bilc, Daniel I.; Ghosez, Philippe

    2017-02-01

    Using a combination of first-principles calculations based on density functional theory and Boltzmann semiclassical transport theory, we compute and study the properties of pristine layered calcium cobaltite Ca3Co4O9 . We model the system with the B1WC hybrid functional. Two supercells of increasing size which approximate the incommensurate crystallographic structure of the compound are studied and we determine their structural, magnetic, and electronic properties. It is found that the B1WC hybrid functional is appropriate to reproduce the structural, electronic, and magnetic properties, which are then extensively discussed. From the electronic band structure, the Seebeck (S ) and electrical resistivity (ρ ) tensors are computed using Boltzmann transport theory within the constant relaxation-time approximation. The differences between the diagonal components are detailed and reveal a strong in-plane anisotropy of the properties. The qualitative behavior of the averaged in-plane properties, S// and ρ//, is consistent with the measurements reported in the literature. Our calculation clarifies and provides a broad picture of the evolution of the thermoelectric properties with both carrier density and temperature, and suggests that the change in S// and ρ// around 100 K is not necessarily related to the magnetic transitions occurring around 100 K.

  1. A Novel Degradation Estimation Method for a Hybrid Energy Storage System Consisting of Battery and Double-Layer Capacitor

    Directory of Open Access Journals (Sweden)

    Yuanbin Yu

    2016-01-01

    Full Text Available This paper presents a new method for battery degradation estimation using a power-energy (PE function in a battery/ultracapacitor hybrid energy storage system (HESS, and the integrated optimization which concerns both parameters matching and control for HESS has been done as well. A semiactive topology of HESS with double-layer capacitor (EDLC coupled directly with DC-link is adopted for a hybrid electric city bus (HECB. In the purpose of presenting the quantitative relationship between system parameters and battery serving life, the data during a 37-minute driving cycle has been collected and decomposed into discharging/charging fragments firstly, and then the optimal control strategy which is supposed to maximally use the available EDLC energy is presented to decompose the power between battery and EDLC. Furthermore, based on a battery degradation model, the conversion of power demand by PE function and PE matrix is applied to evaluate the relationship between the available energy stored in HESS and the serving life of battery pack. Therefore, according to the approach which could decouple parameters matching and optimal control of the HESS, the process of battery degradation and its serving life estimation for HESS has been summed up.

  2. A hybrid CMOS-imager with a solution-processable polymer as photoactive layer

    Science.gov (United States)

    Baierl, Daniela; Pancheri, Lucio; Schmidt, Morten; Stoppa, David; Dalla Betta, Gian-Franco; Scarpa, Giuseppe; Lugli, Paolo

    2012-11-01

    The solution-processability of organic photodetectors allows a straightforward combination with other materials, including inorganic ones, without increasing cost and process complexity significantly compared with conventional crystalline semiconductors. Although the optoelectronic performance of these organic devices does not outmatch their inorganic counterparts, there are certain applications exploiting the benefit of the solution-processability. Here we demonstrate that the small pixel fill factor of present complementary metal oxide semiconductor-imagers, decreasing the light sensitivity, can be increased up to 100% by replacing silicon photodiodes with an organic photoactive layer deposited with a simple low-cost spray-coating process. By performing a full optoelectronic characterization on this first solution-processable hybrid complementary metal oxide semiconductor-imager, including the first reported observation of different noise types in organic photodiodes, we demonstrate the suitability of this novel device for imaging. Furthermore, by integrating monolithically different organic materials to the chip, we show the cost-effective portability of the hybrid concept to different wavelength regions.

  3. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    Science.gov (United States)

    Nan, Alexandrina; Bunge, Alexander; Turcu, Rodica

    2015-12-01

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  4. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    Energy Technology Data Exchange (ETDEWEB)

    Nan, Alexandrina, E-mail: alexandrina.nan@itim-cj.ro; Bunge, Alexander; Turcu, Rodica [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca (Romania)

    2015-12-23

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  5. Transient Response of Thin Wire above a Layered Half-Space Using TDIE/FDTD Hybrid Method

    Directory of Open Access Journals (Sweden)

    Bing Wei

    2012-01-01

    Full Text Available The TDIE/FDTD hybrid method is applied to calculate the transient responses of thin wire above a lossy layered half-space. The time-domain reflection of the layered half space is computed by one-dimensional modified FDTD method. Then, transient response of thin wire induced by two excitation sources (the incident wave and reflected wave is calculated by TDIE method. Finally numerical results are given to illustrate the feasibility and high efficiency of the presented scheme.

  6. Luminescent hybrid materials based on laponite clay.

    Science.gov (United States)

    Li, Huanrong; Li, Man; Wang, Yu; Zhang, Wenjun

    2014-08-11

    The spectroscopic behavior of ionic Eu(3+) or Tb(3+) complexes of an aromatic carboxyl-functionalized organic salt as well as those of the hybrid materials derived from adsorption of the ionic complexes on Laponite clay are reported. X-ray diffraction (XRD) patterns suggest that the complexes are mainly adsorbed on the outer surfaces of the Laponite disks rather than intercalated within the interlayer spaces. Photophysical data showed that the energy-transfer efficiency from the ligand to Eu(3+) ions in the hybrid material is increased remarkably with respect to the corresponding ionic complex. The hybrid material containing the Eu(3+) complex shows bright red emission from the prominent (5) D0 →(7) F2 transition of Eu(3+) ions, and that containing the Tb(3+) complex exhibits bright green emission due to the dominant (5) D4 →(7) F5 transition of Tb(3+) ions.

  7. Ultrasensitive Cracking-Assisted Strain Sensors Based on Silver Nanowires/Graphene Hybrid Particles.

    Science.gov (United States)

    Chen, Song; Wei, Yong; Wei, Siman; Lin, Yong; Liu, Lan

    2016-09-28

    Strain sensors with ultrahigh sensitivity under microstrain have numerous potential applications in heartbeat monitoring, pulsebeat detection, sound signal acquisition, and recognition. In this work, a two-part strain sensor (i.e., polyurethane part and brittle conductive hybrid particles layer on top) based on silver nanowires/graphene hybrid particles is developed via a simple coprecipitation, reduction, vacuum filtration, and casting process. Because of the nonuniform interface, weak interfacial bonding, and the hybrid particles' point-to-point conductive networks, the crack and overlap morphologies are successfully formed on the strain sensor after a prestretching; the crack-based stain sensor exhibits gauge factors as high as 20 (Δε sensor. Combined with its good response to bending, high strain resolution, and high working stability, the developed strain sensor is promising in the applications of electronic skins, motion sensors, and health monitoring sensors.

  8. A Transport Model of Mobile Agent Based on Secure Hybrid Encryption

    Institute of Scientific and Technical Information of China (English)

    SUNZhixin; CHENZhixian; WANGRuchuan

    2005-01-01

    The solution of security problems of mobile agents is a key issue, which will decide whether mobile agents can be widely used. The paper analyzes main security problems, which currently are confronted with mobile agent systems and existing protection solutions. And then the paper presents a Security Transport model of mobile agents based on a hybrid encryption algorithm (TMSHE).Meanwhile, it expatiates on implementation of the algorithm. The algorithm of TMSHE model mainly consists of two parts, i.e., employing a hybrid encryption algorithm to encrypt mobile agents and using Transport layer security (TLS) to encrypt communication channel. Mobile agents by hybrid encryption move through communication channels, which are encrypted by TLS. The simulation results indicate that the model can protect mobile agents' security effectively, and consequently the security and steadiness of the whole mobile agent system are also improved. The model has succeeded in getting application in a prototypesystem- Intrusion detection system based on mobile agents.

  9. Hybrid 2D-nanomaterials-based electrochemical immunosensing strategies for clinical biomarkers determination.

    Science.gov (United States)

    Campuzano, S; Pedrero, M; Nikoleli, G-P; Pingarrón, J M; Nikolelis, D P

    2017-03-15

    Owing to the outstanding conductivity and biocompatibility as well as numerous other fascinating properties of two-dimensional (2D)-nanomaterials, 2D-based nanohybrids have shown unparalleled superiorities in the field of electrochemical biosensors. This review highlights latest advances in electrochemical immunosensors for clinical biomarkers based on different hybrid 2D-nanomaterials. Particular attention will be given to hybrid nanostructures involving graphene and other graphene-like 2D-layered nanomaterials (GLNs). Several recent strategies for using such 2D-nanomaterial heterostructures in the development of modern immunosensors, both for tagging or modifying electrode transducers, are summarized and discussed. These hybrid nanocomposites, quite superior than their rival materials, will undoubtedly have an important impact within the near future and not only in clinical areas. Current challenges and future perspectives in this rapidly growing field are also outlined.

  10. Hybrid Power Management-Based Vehicle Architecture

    Science.gov (United States)

    Eichenberg, Dennis J.

    2011-01-01

    Hybrid Power Management (HPM) is the integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications (s ee figure). The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The basic vehicle architecture consists of a primary power source, and possibly other power sources, that provides all power to a common energy storage system that is used to power the drive motors and vehicle accessory systems. This architecture also provides power as an emergency power system. Each component is independent, permitting it to be optimized for its intended purpose. The key element of HPM is the energy storage system. All generated power is sent to the energy storage system, and all loads derive their power from that system. This can significantly reduce the power requirement of the primary power source, while increasing the vehicle reliability. Ultracapacitors are ideal for an HPM-based energy storage system due to their exceptionally long cycle life, high reliability, high efficiency, high power density, and excellent low-temperature performance. Multiple power sources and multiple loads are easily incorporated into an HPM-based vehicle. A gas turbine is a good primary power source because of its high efficiency, high power density, long life, high reliability, and ability to operate on a wide range of fuels. An HPM controller maintains optimal control over each vehicle component. This flexible operating system can be applied to all vehicles to considerably improve vehicle efficiency, reliability, safety, security, and performance. The HPM-based vehicle architecture has many advantages over conventional vehicle architectures. Ultracapacitors have a much longer cycle life than batteries, which greatly improves system reliability, reduces life-of-system costs, and reduces environmental impact as ultracapacitors will probably never need to be

  11. Splitting and Updating Hybrid Knowledge Bases (Extended Version)

    CERN Document Server

    Slota, Martin; Swift, Terrance

    2011-01-01

    Over the years, nonmonotonic rules have proven to be a very expressive and useful knowledge representation paradigm. They have recently been used to complement the expressive power of Description Logics (DLs), leading to the study of integrative formal frameworks, generally referred to as hybrid knowledge bases, where both DL axioms and rules can be used to represent knowledge. The need to use these hybrid knowledge bases in dynamic domains has called for the development of update operators, which, given the substantially different way Description Logics and rules are usually updated, has turned out to be an extremely difficult task. In [SL10], a first step towards addressing this problem was taken, and an update operator for hybrid knowledge bases was proposed. Despite its significance -- not only for being the first update operator for hybrid knowledge bases in the literature, but also because it has some applications - this operator was defined for a restricted class of problems where only the ABox was all...

  12. Titanium dioxide-cellulose hybrid nanocomposite based conductometric glucose biosensor

    Science.gov (United States)

    Maniruzzaman, Mohammad; Mahadeva, Suresha K.; Khondoker, Abu Hasan; Kim, Jaehwan

    2012-04-01

    This paper investigates the feasibility of conductometric glucose biosensor based on glucose oxidase (GOx) immobilized TiO2-cellulose hybrid nanocomposite. TiO2 nanoparticles were blended with cellulose solution prepared by dissolving cotton pulp with lithium chloride/N, N-dimethylacetamide solvent to fabricate TiO2-cellulose hybrid nanocomposite. The enzyme (GOx) was immobilized into this hybrid material by physical adsorption method. The successful immobilization of GOx into TiO2-cellulose hybrid nanocomposite via covalent bonding between TiO2 and GOx was confirmed by X-ray photoelectron analysis. The linear response of our propose glucose biosensor is obtained in the range of 1-10mM with correlation coefficient of 0.93. Our study demonstrates TiO2-cellulose hybrid material as a potential candidate for an inexpensive, flexible and disposable glucose biosensor.

  13. Time Series Prediction based on Hybrid Neural Networks

    Directory of Open Access Journals (Sweden)

    S. A. Yarushev

    2016-01-01

    Full Text Available In this paper, we suggest to use hybrid approach to time series forecasting problem. In first part of paper, we create a literature review of time series forecasting methods based on hybrid neural networks and neuro-fuzzy approaches. Hybrid neural networks especially effective for specific types of applications such as forecasting or classification problem, in contrast to traditional monolithic neural networks. These classes of problems include problems with different characteristics in different modules. The main part of paper create a detailed overview of hybrid networks benefits, its architectures and performance under traditional neural networks. Hybrid neural networks models for time series forecasting are discussed in the paper. Experiments with modular neural networks are given.

  14. Interaction between the lower hybrid wave and density fluctuations in the scrape-off layer

    Energy Technology Data Exchange (ETDEWEB)

    Peysson, Y., E-mail: yves.peysson@cea.fr [CEA, IRFM, 13108 Saint Paul-lez-Durance (France); Madi, M.; Kabalan, K. [AUB, Bliss Street (Lebanon); Decker, J. [EPFL, CRPP (Switzerland)

    2015-12-10

    In the present paper, the perturbation of the launched power spectrum of the Lower Hybrid wave at the separatrix by electron density fluctuations in the scrape-off layer is investigated. Considering a slab geometry with magnetic field lines parallel to the toroidal direction, the full wave equation is solved using Comsol Multiphysics® for a fully active multi-junction like LH antenna made of two modules. When electron density fluctuations are incorporated in the dielectric tensor over a thin perturbed layer in front of the grill, it is shown that the power spectrum may be strongly modified from the antenna mouth to the plasma separatrix as the wave propagates. The diffraction effect leads to the appearance of multiple satellite lobes with randomly varying positions, a feature consistent with the recently developed model that has been applied successfully to high density discharges on the Tokamak Tore Supra corresponding to the large spectral gap regime [Decker J. et al. Phys. Plasma 21 (2014) 092504]. The perturbation is found to be maximum for the Fourier components of the fluctuating spectrum in the vicinity of the launched LH wavelength.

  15. N-type polymers as electron extraction layers in hybrid perovskite solar cells with improved ambient stability

    NARCIS (Netherlands)

    Shao, S.; Chen, Z.; Fang, H. -H.; ten Brink, G. H.; Bartesaghi, D.; Adjokatse, S.; Koster, L. J. A.; Kooi, B. J.; Facchetti, A.; Loi, M. A.

    2016-01-01

    We studied three n-type polymers of the naphthalenediimide-bithiophene family as electron extraction layers (EELs) in hybrid perovskite solar cells. The recombination mechanism in these devices is found to be heavily influenced by the EEL transport properties. The maximum efficiency of the devices u

  16. Graphene oxide as a highly selective substrate to synthesize a layered MoS2 hybrid electrocatalyst.

    Science.gov (United States)

    Firmiano, Edney G S; Cordeiro, Marcos A L; Rabelo, Adriano C; Dalmaschio, Cleocir J; Pinheiro, Antonio N; Pereira, Ernesto C; Leite, Edson R

    2012-08-11

    We merged the microwave synthesis approach with an extension of the nonhydrolytic sol-gel method to induce highly selective crystallization of MoS(2) layers over graphene sheets. This hybrid material showed superior electrocatalytic activity in hydrogen evolution reactions.

  17. Diffraction anomalies in hybrid structures based on chalcogenide-coated opal photonic crystals

    CERN Document Server

    Voronov, M M; Yakovlev, S A; Kurdyukov, D A; Golubev, V G

    2014-01-01

    The results of spectroscopic studies of the diffraction anomalies (the so-called resonant Wood anomalies) in spatially-periodic hybrid structures based on halcogenide (GST225)-coated opal films of various thickness are presented. A theoretical analysis of spectral-angular dependencies of the Wood anomalies has been made by means of a phenomenological approach using the concept of the effective refractive index of waveguiding surface layer.

  18. A Hybrid Networking Model for the Access Layer of the Communication Network for Distribution in Smart Grid

    Directory of Open Access Journals (Sweden)

    Wang Hao

    2016-01-01

    Full Text Available The access layer in the communication network for distribution is an important link in the automation of smart distribution power grid. In current access layer of communication network for distribution in Chinese power grid systems, several communication methods like optical fiber, mediumvoltage carrier communication, 1.8GHz TD-LTE power private wireless network, 230MHz TD-LTE power private wireless network, public wireless network are constructed concurrently and running simultaneously in an identical power supply area. This traditional networking model will cause repeated construction and operation and maintenance difficulties in the communication network of power grid. On the basis of giving a detailed analysis of the radio link budget of TD-LTE power private wireless network in two frequencies, this paper present a multi-communication methods hybrid networking model, which gives a clear boundary for different communication methods based on the isoline with equal signal strength of the TD-LTE power private wireless network and accomplish the optimization of communication resources for distribution.

  19. Directing Hybrid Structures by Combining Self-Assembly of Functional Block Copolymers and Atomic Layer Deposition: A Demonstration on Hybrid Photovoltaics.

    Science.gov (United States)

    Moshonov, Moshe; Frey, Gitti L

    2015-11-24

    The simplicity and versatility of block copolymer self-assembly offers their use as templates for nano- and meso-structured materials. However, in most cases, the material processing requires multiple steps, and the block copolymer is a sacrificial building block. Here, we combine a self-assembled block copolymer template and atomic layer deposition (ALD) of a metal oxide to generate functional hybrid films in a simple process with no etching or burning steps. This approach is demonstrated by using the crystallization-induced self-assembly of a rod-coil block copolymer, P3HT-b-PEO, and the ALD of ZnO. The block copolymer self-assembles into fibrils, ∼ 20 nm in diameter and microns long, with crystalline P3HT cores and amorphous PEO corona. The affinity of the ALD precursors to the PEO corona directs the exclusive deposition of crystalline ZnO within the PEO domains. The obtained hybrid structure possesses the properties desired for photovoltaic films: donor-acceptor continuous nanoscale interpenetrated networks. Therefore, we integrated the films into single-layer hybrid photovoltaics devices, thus demonstrating that combining self-assembly of functional block copolymers and ALD is a simple approach to direct desired complex hybrid morphologies.

  20. Investigation of bulk hybrid heterojunction solar cells based on Cu(In,Ga)Se2 nanocrystals.

    Science.gov (United States)

    Yen, Yu-Ting; Lin, Yi-Kai; Chang, Shu-Hao; Hong, Hwen-Fen; Tuan, Hsing-Yu; Chueh, Yu-Lun

    2013-07-19

    This work presents the systematic studies of bulk hybrid heterojunction solar cells based on Cu(In, Ga)Se2 (CIGS) nanocrystals (NCs) embedded in poly(3-hexylthiophene) matrix. The CIGS NCs of approximately 17 nm in diameter were homogeneously blended with P3HT layer to form an active layer of a photovoltaic device. The blend ratios of CIGS NCs to P3HT, solvent effects on thin film morphologies, interface between P3HT/CIGS NCs and post-production annealing of devices were investigated, and the best performance of photovoltaic devices was measured under AM 1.5 simulated solar illumination (100 mW/cm2).

  1. Composite titanium nitride layers produced on the AZ91D magnesium alloy by a hybrid method including hydrothermal modification of the layer

    Science.gov (United States)

    Tacikowski, M.; Grzonka, J.; Płociński, T.; Jakieła, R.; Pisarek, M.; Wierzchoń, T.

    2015-08-01

    The microstructure and properties of the composite TiN-Ti-Al type titanium nitride surface layer with a sub-layer of titanium and aluminium produced on AZ91D magnesium alloy using a hybrid PVD method including final sealing by hydrothermal treatment were investigated. The results were analysed in terms of the microstructure-properties correlation, to approach the role of the sub-layers and the mechanisms involved in the properties improvement. The microstructure investigations indicate that the composite titanium nitride layers are tight and have nano-crystalline, diffusive character and multi zone microstructure of the type TixOy-TiN-Ti-Al-Al3Mg2-Al12Mg17. The significant corrosion resistance improvement of the AZ91D alloy obtained using the sealed composite titanium nitride layers was found to be the result of a synergistic mechanism which combined hydrothermal treatment of the layer with an action of aluminium sub-layer which is critical to make the sealing effective. The diffusive bonding via Mg-Al zone improves adhesion and the load bearing capacity of titanium nitride layers in wear conditions.

  2. Layer-based buffer aware rate adaptation design for SHVC video streaming

    Science.gov (United States)

    Gudumasu, Srinivas; Hamza, Ahmed; Asbun, Eduardo; He, Yong; Ye, Yan

    2016-09-01

    This paper proposes a layer based buffer aware rate adaptation design which is able to avoid abrupt video quality fluctuation, reduce re-buffering latency and improve bandwidth utilization when compared to a conventional simulcast based adaptive streaming system. The proposed adaptation design schedules DASH segment requests based on the estimated bandwidth, dependencies among video layers and layer buffer fullness. Scalable HEVC video coding is the latest state-of-art video coding technique that can alleviate various issues caused by simulcast based adaptive video streaming. With scalable coded video streams, the video is encoded once into a number of layers representing different qualities and/or resolutions: a base layer (BL) and one or more enhancement layers (EL), each incrementally enhancing the quality of the lower layers. Such layer based coding structure allows fine granularity rate adaptation for the video streaming applications. Two video streaming use cases are presented in this paper. The first use case is to stream HD SHVC video over a wireless network where available bandwidth varies, and the performance comparison between proposed layer-based streaming approach and conventional simulcast streaming approach is provided. The second use case is to stream 4K/UHD SHVC video over a hybrid access network that consists of a 5G millimeter wave high-speed wireless link and a conventional wired or WiFi network. The simulation results verify that the proposed layer based rate adaptation approach is able to utilize the bandwidth more efficiently. As a result, a more consistent viewing experience with higher quality video content and minimal video quality fluctuations can be presented to the user.

  3. Performance analysis of switching based hybrid FSO/RF transmission

    KAUST Repository

    Usman, Muneer

    2014-09-01

    Hybrid free space optical (FSO)/ radio frequency (RF) systems have emerged as a promising solution for high data rate wireless back haul.We present and analyze a switching based transmission scheme for hybrid FSO/RF system. Specifically, either FSO or RF link will be active at a certain time instance, with FSO link enjoying a higher priority. Analytical expressions have been obtained for the outage probability, average bit error rate and ergodic capacity for the resulting system. Numerical examples are presented to compare the performance of the hybrid scheme with FSO only scenario.

  4. A high-quality factor hybrid plasmonic nanocavity based on distributed Bragg reflectors

    Science.gov (United States)

    Tu, Linlin; Zhang, Chi; Huang, Zhong; Yau, Jason; Zhan, Peng; Wang, Zhenlin

    2016-09-01

    Herein, we propose a high-quality (Q) factor hybrid plasmonic nanocavity based on distributed Bragg reflectors (DBRs) with low propagation loss and extremely strong mode confinement. This hybrid plasmonic nanocavity is composed of a high-index cylindrical nanowire separated from a metal surface possessing shallow DBRs gratings by a sufficiently thin low-index dielectric layer. The hybrid plasmonic nanocavity possesses advantages such as a high Purcell factor (Fp) of up to nearly 20000 and a gain threshold approaching 266 cm-1 at 1550 nm, promising a greater potential in deep sub-wavelength lasing applications. Project supported by the National Key Basic Research Special Foundation of China (Grant Nos. 2012CB921501 and 2013CB632703) and the National Natural Science Foundation of China (Grant Nos. 11274160, 91221206, and 51271092).

  5. A multifunctional organic-inorganic hybrid structure based on Mn(III)-porphyrin and polyoxometalate as a highly effective dye scavenger and heterogenous catalyst.

    Science.gov (United States)

    Zou, Chao; Zhang, Zhijuan; Xu, Xuan; Gong, Qihan; Li, Jing; Wu, Chuan-De

    2012-01-11

    A two-step synthesis strategy has led to a unique layered polyoxometalate-Mn(III)-metalloporphyrin-based hybrid material. The hybrid solid demonstrates remarkable capability for scavenging of dyes and for heterogeneous selective oxidation of alkylbenzenes with excellent product yields and 100% selectivity.

  6. An Algorithm on Generating Lattice Based on Layered Concept Lattice

    Directory of Open Access Journals (Sweden)

    Zhang Chang-sheng

    2013-08-01

    Full Text Available Concept lattice is an effective tool for data analysis and rule extraction, a bottleneck factor on impacting the applications of concept lattice is how to generate lattice efficiently. In this paper, an algorithm LCLG on generating lattice in batch processing based on layered concept lattice is developed, this algorithm is based on layered concept lattice, the lattice is generated downward layer by layer through concept nodes and provisional nodes in current layer; the concept nodes are found parent-child relationships upward layer by layer, then the Hasse diagram of inter-layer connection is generated; in the generated process of the lattice nodes in each layer, we do the pruning operations dynamically according to relevant properties, and delete some unnecessary nodes, such that the generating speed is improved greatly; the experimental results demonstrate that the proposed algorithm has good performance.

  7. A hybrid surface layer parameterization scheme for the two-way fully coupled atmosphere-ocean wave system WEW

    Science.gov (United States)

    Katsafados, Petros; Papadopoulos, Anastasios; Varlas, George; Korres, Gerasimos

    2015-04-01

    The two-way fully coupled atmosphere-ocean wave system WEW has been recently developed in order to study the factors that contribute to the air-sea interaction processes and feedbacks. The coupled system consists of two components: the atmospheric component which is based on the Workstation Eta non-hydrostatic limited area model and the ocean-wave component which is based on the fourth generation OpenMP (OMP) version of the WAM model. The WEW has been already evaluated in a number of high-impact weather and sea state events where generally a more realistic representation of the momentum exchanges in the ocean wind-wave system has been shown However, the new developed wind-wave parameterization scheme reduces both the near surface wind speed and the significant wave height as a response to the increased aerodynamic drag considered by the atmospheric model over rough sea surfaces. Such behavior is mainly attributed to the surface layer parameterization scheme of the atmospheric component which is based on the Mellor-Yamada-Janjic (MYJ) scheme. It is noted that this scheme has been adjusted to support independent atmospheric simulations. Therefore, we proceed to develop a new hybrid surface layer parameterization based on the MYJ and the Janssen schemes that operate in the atmospheric and ocean wave components of the WEW, respectively. In this case the roughness length depends on the wave age instead of the Charnock parameter following the formulation proposed by Vickers and Mahrt. The spatial variability of the wave age is estimated at each ocean wave component time step and it is directly provided to the MYJ scheme. The parameterization of the viscous sublayer and the universal functions for the estimation of the near surface wind speed have been also revised accordingly. In this study, a test version of the new hybrid scheme of WEW has been statistically evaluated against a number of buoys and satellite retrievals over the Mediterranean Sea in a case study of high

  8. A Viola-Jones based hybrid face detection framework

    Science.gov (United States)

    Murphy, Thomas M.; Broussard, Randy; Schultz, Robert; Rakvic, Ryan; Ngo, Hau

    2013-12-01

    Improvements in face detection performance would benefit many applications. The OpenCV library implements a standard solution, the Viola-Jones detector, with a statistically boosted rejection cascade of binary classifiers. Empirical evidence has shown that Viola-Jones underdetects in some instances. This research shows that a truncated cascade augmented by a neural network could recover these undetected faces. A hybrid framework is constructed, with a truncated Viola-Jones cascade followed by an artificial neural network, used to refine the face decision. Optimally, a truncation stage that captured all faces and allowed the neural network to remove the false alarms is selected. A feedforward backpropagation network with one hidden layer is trained to discriminate faces based upon the thresholding (detection) values of intermediate stages of the full rejection cascade. A clustering algorithm is used as a precursor to the neural network, to group significant overlappings. Evaluated on the CMU/VASC Image Database, comparison with an unmodified OpenCV approach shows: (1) a 37% increase in detection rates if constrained by the requirement of no increase in false alarms, (2) a 48% increase in detection rates if some additional false alarms are tolerated, and (3) an 82% reduction in false alarms with no reduction in detection rates. These results demonstrate improved face detection and could address the need for such improvement in various applications.

  9. Bond graph model-based fault diagnosis of hybrid systems

    CERN Document Server

    Borutzky, Wolfgang

    2015-01-01

    This book presents a bond graph model-based approach to fault diagnosis in mechatronic systems appropriately represented by a hybrid model. The book begins by giving a survey of the fundamentals of fault diagnosis and failure prognosis, then recalls state-of-art developments referring to latest publications, and goes on to discuss various bond graph representations of hybrid system models, equations formulation for switched systems, and simulation of their dynamic behavior. The structured text: • focuses on bond graph model-based fault detection and isolation in hybrid systems; • addresses isolation of multiple parametric faults in hybrid systems; • considers system mode identification; • provides a number of elaborated case studies that consider fault scenarios for switched power electronic systems commonly used in a variety of applications; and • indicates that bond graph modelling can also be used for failure prognosis. In order to facilitate the understanding of fault diagnosis and the presented...

  10. TiO-Based Organic Hybrid Solar Cells with Mn+ Doping

    Directory of Open Access Journals (Sweden)

    Zühal Alparslan

    2011-01-01

    Full Text Available A hybrid solar cell is designed and proposed as a feasible and reasonable alternative, according to acquired efficiency with the employment of TiO2 (titanium dioxide and Mn-doped TiO2 thin films. In the scope of this work, TiO2 (titanium dioxide and Mn:TiO2 hybrid organic thin films are proposed as charge transporter layer in polymer solar cells. Poly(3-hexylthiophene:phenyl-C61-butyric acid methyl ester (P3HT: PCBM is used as active layer. When the Mn-doped TiO2 solar cells were compared with pure TiO2 cells, Mn-doped samples revealed a noteworthy efficiency enhancement with respect to undoped-TiO2-based cells. The highest conversion efficiency was obtained to be 2.44% at the ratio of 3.5% (wt/wt Mn doping.

  11. Sizing of a hybrid locomotive based on accumulators and ultracapacitors

    OpenAIRE

    Jaafar, Amine; Sareni, Bruno; Roboam, Xavier; Thiounn-Guermeur, Marina

    2010-01-01

    In this paper, hybridization of a BB460000 locomotive is proposed integrating a reduced power diesel generator, batteries and ultracapacitors as storage elements. The power mission of the BB460000 locomotive is studied in order to analyze its ability to be hybridized and to identify the most critical mission. An energy management strategy based on a frequency sharing is proposed. It allows strongly decreasing the nominal power of the diesel generator. Then, through a power flow sizing model, ...

  12. Hybridization Between Natural Extract of Angelica gigas Nakai and Inorganic Nanomaterial of Layered Double Hydroxide via Reconstruction Reaction.

    Science.gov (United States)

    Kim, Tae-Hyun; Kim, Hyoung-Jun; Choi, Ae-Jin; Choi, Hyun-Jin; Oh, Jae-Min

    2016-01-01

    We have hybridized layered double hydroxide (LDH) with Angelica gigas Nakai root extract (AGNR) through reversible dehydration-rehydration reaction which is known as reconstruction. LDHs having well-ordered hydrotalcite-like crystal structure and average size 250 ± 20 nm were prepared by hydrothermal method. The root of Angelica gigas Nakai, which has been utilized in the treatment of female disorders as herbal medicine, was treated with methanol to obtain extract. Pristine LDHs were calcined at 400 °C for 8 hours to obtain layered double oxide (LDO), which was further dispersed into extract solution with various AGNR/LDO weight ratios, 0.11, 0.21 and 0.43. The extract content in each hybrid increased in proportion to initial AGNR/LDO ratio, showing the highest content of ~12%. The zeta potential of LDH shifted from +44 mV to +20 mV upon hybridization with extract, which was attributed to the adsorption of negatively charged organic moieties in AGNR on LDH surface. The scanning electron microscopic (SEM) results exhibited that the random stacking of LDH nanolayers resulted in LDH-AGNR hybrid with house-of-cards structure, of which inter-particle cavity serves nano-reservoir for natural extract. According to quantitative analyses, it was revealed that the content of active components in AGNR increased when they were hybridized with LDHs compared with those in AGNR alone.

  13. Biosensors Fabricated through Electrostatic Assembly of Enzymes/Polyelectrolyte Hybrid Layers on Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yuehe; Liu, Guodong; Wang, Jun

    2006-06-01

    Carbon nanotubes (CNTs) have emerged as new class of nanomaterials that is receiving considerable interest because of their unique structure, mechanical, and electronic properties. One promising application of CNTs is to fabricate highly sensitive chemo/biosensors.1-4 For construction of these CNT-based sensors, the CNTs first have to be modified with some molecules specific to the interests. Generally, covalent binding, affinity, and electrostatic interaction have been utilized for the modification of CNTs. Among them, the electrostatic method is attractive due to its simplicity and high efficiency. In present work, we have developed highly sensitively amperometric biosensors for glucose, choline, organophosphate pesticide (OPP) and nerve agents (NAs) based on electrostatically assembling enzymes on the surface of CNTs. All these biosensors were fabricated by immobilization of enzymes on the negatively charged CNTs surface through alternately assembling a cationic poly(diallydimethylammonium chloride) (PDDA) layer and an enzyme layer. Using this layer-by-layer (LBL) technique, a bioactive nanocomposite film was fabricated on the electrode surface. Owing to the electrocatalytic effect of CNTs, an amplified electrochemical signal was achieved, which leads to low detections limits for glucose, choline, and OPP and NAs.

  14. Evaluation of microleakage in hybrid composite restoration with different intermediate layers and curing cycles

    Directory of Open Access Journals (Sweden)

    Mohan R Sakri

    2016-01-01

    Full Text Available Objective: To evaluate the impact of bulk or incremental curing of hybrid composite resin with different intermediate layers on interfacial microleakage. Materials and Methods: The recently extracted, sixty noncarious human mandibular molars were selected for the study. The standardized mesio-occluso-distal cavity with the occlusal cavity of 2 mm depth, 3 mm buccolingual width and proximal box dimension of 4 mm buccolingual width and 2 mm depth was prepared on all experimental teeth. The samples were divided into six groups of ten each. Group I was without an intermediate layer. Group II and III had 1 mm flowable composite liner, with incremental and bulk curing cycle, respectively. The Group IV, V, and VI had a self-cure composite liner with incremental and bulk curing. The teeth subjected to thermocycling and kept in 0.5% basic fuchsine dye for 24 h. The teeth were sectioned and observed under a stereomicroscope to grade them according to the extent of microleakage. The obtained data were statistically analyzed with Kruskal–Wallis and post hoc comparison test to understand the difference between the groups. Results: The Group II with flowable composite along incremental curing showed the least microleakage at both enamel (0.30 and cementum surface (0.50. The groups with self-cure composite liner were less effective than flowable composite. The microleakage at the enamel interface was less compared cementum interface across the groups. The groups with bulk curing were more prone to microleakage than incremental curing cycle. Conclusions: Within the limitation of the study, it was concluded that intermediate flowable composite with incremental curing was better suited to reduce microleakage.

  15. Kinetic-based layer response to RMPs

    Science.gov (United States)

    Callen, J. D.; Hegna, C. C.; Cole, A. J.

    2012-10-01

    Plasma toroidal rotation can prevent reconnection of resonant magnetic perturbation (RMP) fields near rational surfaces. A low collisionality kinetic toroidal model of RMP-flutter-induced electron density and thermal transport in toroidally flowing plasmas has been developed [1]. Since this electron transport is non-ambipolar, it produces a co-current toroidal torque on the plasma. This low collisionality torque differs from fluid-based cylindrical results [2] in three key ways: the effective electron collision frequency is increased because only untrapped electrons carry parallel currents, this effect increases the singular layer width, and electron temperature gradient effects are included. A Te gradient torque is caused by the parallel electron thermal force which is usually neglected in Ohm's law. It changes the perpendicular electron flow where the torque at the rational surface vanishes to where (e/Te)(dφ/dr)=dpe/dr+cTdTe/dr in which cT is 0.71 for Z=1. The cT!=0 effect moves the radial location for RMP field penetration and hence reconnection to smaller radii relative to theories [2] that neglect the thermal force.[4pt] [1] J.D. Callen, A.J. Cole and C.C. Hegna, UW-CPTC 11-15R (2012).[0pt] [2] F.L. Waelbroeck et al., Nucl. Fusion 52, 074004 (2012).

  16. 面向个性化推荐的两层混合图模型%Hybrid Graph Model with Two Layers for Personalized Recommendation

    Institute of Scientific and Technical Information of China (English)

    张少中; 陈德人

    2009-01-01

    A hybrid graph model for personalized recom-mendation,which is based on small world network and Bayesian network,is presented.The hybrid graph model has two-layers.The bottom level means user's layer and the upper one means merchandise's layer.The user's layer is an undirected arcs graph,which describes the relation of the user's nodes by small world network.The undirected arcs inside the connected nodes of user's layer mean the similarity of the preference of users.These arcs are weighted by relational strength.The weight represents node's similarity or link's strength and intensity.Nodes in the same group are more similar to each other or more strongly connected.Users in a produce to others.It is connected by directed links,which means an implicated definition among merchandises,a user that purchase certain merchandise also tends to purchase another.The properties and content of merchandise can be used to show the similarity of the merchandise.The relations between user's layer and merchandise's layer are connected by directed links.The start nede of the directed links is a user node in user's layer belonging to some node group,which is gained by small world network.The end node of links is the node of some merchandise of the merchandise's layer.The directed links between the user's layer and the merchandise's layer are connected based on trade information of users.The strength of the relation between users and merchandises can be denoted by the probability parameter.The probability parameter shows a possibility of some users selecting for some merchandises. Firstly,algorithms for users clustering and for analysis of new user interest are presented to construct a hybrid graph model.Two important characteristic parameters,which are in small-world network,are introduced.These are characteristic path length and clustering coefficient.New user interest analysis is to judge which clustering group is the best match by calculating the distance of the new user node to

  17. Single layer graphene band hybridization with silver nanoplates: Interplay between doping and plasmonic enhancement

    Science.gov (United States)

    Syed, Salmaan R.; Lim, Guh-Hwan; Flanders, Stuart J.; Taylor, Adam B.; Lim, Byungkwon; Chon, James W. M.

    2016-09-01

    In this paper, we report single layer graphene (SLG) hybridized with silver nanoplates, in which nanoplates act as either a charge doping or a field enhancement source for the SLG Raman spectrum. Surprisingly, the stiffening of both G and 2D peaks of more than 10 cm-1 was observed with no plasmonic enhancement of peaks, indicating that p-doping from nanoplates on SLG is occurring. Such observation is explained in terms of the contact separation distance between the graphene and the silver nanoplates being enough (˜4 Å) to cause a Fermi level shift in graphene to allow p-doping. When nanoplates were modified in shape with laser irradiation by either photothermal plasmon printing or laser induced ablation, the charge doping was lifted and the strong plasmonic enhancement of Raman signals was observed, indicating that the separation distance is increased. Further, when the nanoplates are oxidized, the two effects on the Raman bands of SLG are turned off, returning the Raman signals back to the original SLG state.

  18. iBole:A Hybrid Multi-Layer Architecture for Doctor Recommendation in Medical Social Networks

    Institute of Scientific and Technical Information of China (English)

    宫继兵; 王立; 孙胜涛; 彭思维

    2015-01-01

    In this paper, we try to systematically study how to perform doctor recommendation in medical social net-works (MSNs). Specifically, employing a real-world medical dataset as the source in our work, we propose iBole, a novel hybrid multi-layer architecture, to solve this problem. First, we mine doctor-patient relationships/ties via a time-constraint probability factor graph model (TPFG). Second, we extract network features for ranking nodes. Finally, we propose RWR-Model, a doctor recommendation model via the random walk with restart method. Our real-world experiments validate the effectiveness of the proposed methods. Experimental results show that we obtain good accuracy in mining doctor-patient relationships from the network, and the doctor recommendation performance is better than that of the baseline algorithms:traditional Ranking SVM (RSVM) and the individual doctor recommendation model (IDR-Model). The results of our RWR-Model are more reasonable and satisfactory than those of the baseline approaches.

  19. Amperometric Choline Biosensor Fabricated through Electrostatic Assembly of Bienzyme/Polyelectrolyte Hybrid Layers on Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun; Liu, Guodong; Lin, Yuehe

    2006-03-01

    We report a flow injection amperometric choline biosensors based on the electrostatic assembly of an enzyme of choline oxidase (ChO) and a bi-enzyme of ChO and horseradish peroxidase (HRP) onto multi-wall carbon nanotubes (MWCNT) modified glassy carbon (GC) electrodes. These choline biosensors were fabricated by immobilization of enzymes on the negatively charged MWCNT surface through alternatively assembling a cationic polydiallydiimethylammonium chloride (PDDA) layer and an enzyme layer. Using this layer-by-layer assembling approach, bioactive nanocomposite film of a PDDA/ChO/PDDA/HRP/PDDA/CNT (ChO/HRP/CNT) and a PDDA/ChO/PDDA/ CNT (ChO/ CNT) were fabricated on GC surface, respectively. Owning to the electrocatalytic effect of carbon nanotubes, the measurement of faradic responses resulting from enzymatic reactions has been realized at low potential with acceptable sensitivity. It is found the ChO/HRP/CNT biosensor is more sensitive than the ChO/CNT one. Experimental parameters affecting the sensitivity of biosensors, e.g. applied potential, flow rate, etc. were optimized and potential interference was examined. The response time for this choline biosensor is fast (less than a few seconds). The linear range of detection for the choline biosensor is from 5 x 10-5 to 5 x 10-3 M and the detection limit is determined to be about 1.0 x 10-5 M.

  20. Ultrathin oligonucleotide layers for fluorescence-based DNA sensors

    Science.gov (United States)

    Furch, M.; Ueberfeld, J.; Hartmann, Andreas; Bock, Daniel; Seeger, Stefan

    1996-11-01

    Preliminary investigations into the design of an affinity sensor using evanescent wave technology concentrate upon the means of immobilization of the receptor molecules. In this work DNA served as the selective recognition element. The molecular principle of a sequence-selective biosensor for DNA is based on a sandwich-hybridization assay wherein the analyte, a single-stranded (ss)DNA, bound specifically to both an immobilized capture probe and a dye-labeled oligonucleotide in free solution. The efficiency of the capture array depends on the density of highly organized oligonucleotides on the waveguide surface and correlates therefore directly with the specificity and the sensitivity of the sensor. In the present approach using the Langmuir- Blodgett technique cinnamoylbutylether-cellulose monolayers were transferred onto optical fibers or planar waveguides. These films served as matrices for the immobilization of biotinylated oligonucleotides via streptavidin. For the first time streptavidin was immobilized by that manner. The specificity of the streptavidin layer or the following bounded nucleic acid molecules were controlled by an enzyme- linked immunosorbent assay (ELISA). Finally, this application has also shown to be suitable for the detection of Salmonella, which is an important pathogen associated with acute gastroenteritidis and food borne diseases.

  1. A method of layer-by-layer gold nanoparticle hybridization in a quartz crystal microbalance DNA sensing system used to detect dengue virus

    Science.gov (United States)

    Chen, Sz-Hau; Chuang, Yao-Chen; Lu, Yi-Chen; Lin, Hsiu-Chao; Yang, Yun-Liang; Lin, Chih-Sheng

    2009-05-01

    Dengue virus (DENV) is nowadays the most important arthropod-spread virus affecting humans existing in more than 100 countries worldwide. A rapid and sensitive detection method for the early diagnosis of infectious dengue virus urgently needs to be developed. In the present study, a circulating-flow quartz crystal microbalance (QCM) biosensing method combining oligonucleotide-functionalized gold nanoparticles (i.e. AuNP probes) used to detect DENV has been established. In the DNA-QCM method, two kinds of specific AuNP probes were linked by the target sequences onto the QCM chip to amplify the detection signal, i.e. oscillatory frequency change (ΔF) of the QCM sensor. The target sequences amplified from the DENV genome act as a bridge for the layer-by-layer AuNP probes' hybridization in the method. Besides being amplifiers of the detection signal, the specific AuNP probes used in the DNA-QCM method also play the role of verifiers to specifically recognize their target sequences in the detection. The effect of four AuNP sizes on the layer-by-layer hybridization has been evaluated and it is found that 13 nm AuNPs collocated with 13 nm AuNPs showed the best hybridization efficiency. According to the nanoparticle application, the DNA-QCM biosensing method was able to detect dengue viral RNA in virus-contaminated serum as plaque titers being 2 PFU ml-1 and a linear correlation (R2 = 0.987) of ΔF versus virus titration from 2 × 100 to 2 × 106 PFU ml-1 was found. The sensitivity and specificity of the present DNA-QCM method with nanoparticle technology showed it to be comparable to the fluorescent real-time PCR methods. Moreover, the method described herein was shown to not require expensive equipment, was label-free and highly sensitive.

  2. Design of Transport Layer Based Hybrid Covert Channel Detection Engine

    OpenAIRE

    K, Anjan; Abraham, Jibi; Jadhav V, Mamatha

    2010-01-01

    Computer network is unpredictable due to information warfare and is prone to various attacks. Such attacks on network compromise the most important attribute, the privacy. Most of such attacks are devised using special communication channel called "Covert Channel". The word "Covert" stands for hidden or non-transparent. Network Covert Channel is a concealed communication path within legitimate network communication that clearly violates security policies laid down. The non-transparency in cov...

  3. Hybrid layers deposited by an atmospheric pressure plasma process for corrosion protection of galvanized steel.

    Science.gov (United States)

    Del Frari, D; Bour, J; Bardon, J; Buchheit, O; Arnoult, C; Ruch, D

    2010-04-01

    Finding alternative treatments to reproduce anticorrosion properties of chromated coatings is challenging since both physical barrier and self-healing effects are needed. Siloxane based treatments are known to be a promising way to achieve physical barrier coatings, mainly plasma polymerized hexamethyldisiloxane (ppHMDSO). In addition, it is known that cerium-based coatings can also provide corrosion protection of metals by means of self-healing effect. In this frame, innovative nanoAlCeO3/ppHMDSO layers have thus been deposited and studied. These combinations allow to afford a good physical barrier effect and active properties. Liquid siloxane and cerium-based particles mixture is atomized and introduced as precursors into a carrier gas. Gas mixture is then injected into an atmospheric pressure dielectric barrier discharge (DBD) where plasma polymerization of the siloxane precursor occurs. The influence of cerium concentration on the coating properties is investigated: coating structure and topography have been studied by scanning electron microscopy (SEM) and interferometry, and corrosion resistance of these different coatings is compared by electrochemistry techniques: polarization curves and electrochemical impedance spectroscopy (EIS). Potential self-healing property afforded by cerium in the layer was studied by associating EIS measurements and nanoscratch controlled damaging. Among the different combinations investigated, mixing of plasma polymerized HMDSO and AICeO3 nanoparticles seems to give promising results with a good physical barrier and interesting electroactive properties. Indeed, corrosion currents measured on such coatings are almost as low as those measured with the chromated film. Combination of nanoscratch damaging of layers with EIS experiments to investigate self-healing also allow to measure the active protection property of such layers.

  4. Efficient fluorescent deep-blue and hybrid white emitting devices based on carbazole/benzimidazole compound

    KAUST Repository

    Yang, Xiaohui

    2011-07-28

    We report the synthesis, photophysics, and electrochemical characterization of carbazole/benzimidazole-based compound (Cz-2pbb) and efficient fluorescent deep-blue light emitting devices based on Cz-2pbb with the peak external quantum efficiency of 4.1% and Commission Internationale dÉnclairage coordinates of (0.16, 0.05). Efficient deep-blue emission as well as high triplet state energy of Cz-2pbb enables fabrication of hybrid white organic light emitting diodes with a single emissive layer. Hybrid white emitting devices based on Cz-2pbb show the peak external quantum efficiency exceeding 10% and power efficiency of 14.8 lm/W at a luminance of 500 cd/m2. © 2011 American Chemical Society.

  5. Extending a Hybrid Tag-Based Recommender System with Personalization

    DEFF Research Database (Denmark)

    Durao, Frederico; Dolog, Peter

    2010-01-01

    extension for a hybrid tag-based recommender system, which suggests similar Web pages based on the similarity of their tags. The semantic extension aims at discovering tag relations which are not considered in basic syntax similarity. With the goal of generating more semantically grounded recommendations...

  6. Two-dimensional hybrid layered materials: strain engineering on the band structure of MoS2/WSe2 hetero-multilayers

    Science.gov (United States)

    Gu, Kunming; Yu, Sheng; Eshun, Kwesi; Yuan, Haiwen; Ye, Huixian; Tang, Jiaoning; Ioannou, Dimitris E.; Xiao, Changshi; Wang, Hui; Li, Qiliang

    2017-09-01

    In this paper, we report a comprehensive modeling and simulation study of constructing hybrid layered materials by alternately stacking MoS2 and WSe2 monolayers. Such hybrid MoS2/WSe2 hetero-multilayers exhibited direct bandgap semiconductor characteristics with bandgap energy (E g) in a range of 0.45-0.55 eV at room temperature, very attractive for optoelectronics (wavelength range 2.5-2.75 μm) based on thicker two-dimensional (2D) materials. It was also found that the interlayer distance has a significant impact on the electronic properties of the hetero-multilayers, for example a five orders of magnitude change in the conductance was observed. Three material phases, direct bandgap semiconductor, indirect bandgap semiconductor, and metal were observed in MoS2/WSe2 hetero-multilayers, as the interlayer distance decreased from its relaxed (i.e., equilibrium) value of about 6.73 Å down to 5.50 Å, representing a vertical pressure of about 0.8 GPa for the bilayer and 1.5 GPa for the trilayer. Such new hybrid layered materials are very interesting for future nanoelectronic pressure sensor and nanophotonic applications. This study describes a new approach to explore and engineer the construction and application of tunable 2D semiconductors.

  7. Room temperature performance of 4 V aqueous hybrid supercapacitor using multi-layered lithium-doped carbon negative electrode

    Science.gov (United States)

    Makino, Sho; Yamamoto, Rie; Sugimoto, Shigeyuki; Sugimoto, Wataru

    2016-09-01

    Water-stable multi-layered lithium-doped carbon (LixC6) negative electrode using poly(ethylene oxide) (PEO)-lithium bis(trifluoromethansulfonyl)imide (LiTFSI) polymer electrolyte containing N-methyl-N-propylpiperidinium bis(trifluoromethansulfonyl)imide (PP13TFSI) ionic liquid was developed. Electrochemical properties at 60 °C of the aqueous hybrid supercapacitor using activated carbon positive electrode and a multi-layered LixC6 negative electrode (LixC6 | PEO-LiTFSI | LTAP) without PP13TFSI exhibited performance similar to that using Li anode (Li | PEO-LiTFSI | LTAP). A drastic decrease in ESR was achieved by the addition of PP13TFSI to PEO-LiTFSI, allowing room temperature operation. The ESR of the multi-layered LixC6 negative electrode with PEO-LiTFSI-PP13TFSI at 25 °C was 801 Ω cm2, which is 1/6 the value of the multi-layered Li negative electrode with PEO-LiTFSI (5014 Ω cm2). Charge/discharge test of the aqueous hybrid supercapacitor using multi-layered LixC6 negative electrode with PEO-LiTFSI-PP13TFSI at 25 °C afforded specific capacity of 20.6 mAh (g-activated carbon)-1 with a working voltage of 2.7-3.7 V, and good long-term capability up to 3000 cycles. Furthermore, an aqueous hybrid supercapacitor consisting of a high capacitance RuO2 nanosheet positive electrode and multi-layered LixC6 negative electrode with PEO-LiTFSI-PP13TFSI showed specific capacity of 196 mAh (g-RuO2)-1 and specific energy of 625 Wh (kg-RuO2)-1 in 2.0 M acetic acid-lithium acetate buffered solution at 25 °C.

  8. Characterization of new hybrid pixel module concepts for the ATLAS Insertable B-Layer upgrade

    CERN Document Server

    Backhaus, Malte

    2012-01-01

    The ATLAS Insertable B-Layer (IBL) collaboration plans to insert a fourth pixel layer inside the present Pixel Detector to recover from eventual failures in the current pixel system, especially the b-layer. Additionally the IBL will ensure excellent tracking, vertexing and b-tagging performance during the LHC phase I and add robustness in tracking with high luminosity pile-up. The expected peak luminosity for IBL is 2 to 3centerdot1034 cm-2s-1 and IBL is designed for an integrated luminosity of 700 fb-1. This corresponds to an expected fluence of 5centerdot1015 1 MeV neqcm-2 and a total ionizing dose of 250 MRad. In order to cope with these requirements, two new module concepts are under investigation, both based on a new front end IC, called FE-I4. This IC was designed as readout chip for future ATLAS Pixel Detectors and its first application will be the IBL. The planar pixel sensor (PPS) based module concept benefits from its well understood design, which is kept as similar as possible to the design of the ...

  9. Characterization of new hybrid pixel module concepts for the ATLAS Insertable B-Layer upgrade

    CERN Document Server

    Backhaus, M

    2012-01-01

    The ATLAS Insertable B-Layer (IBL) collaboration plans to insert a fourth pixel layer inside the present Pixel Detector to recover from eventual failures in the current pixel system, especially the b-layer. Additionally the IBL will ensure excellent tracking, vertexing and b-tagging performance during the LHC phase I and add robustness in tracking with high luminosity pile-up. The expected peak luminosity for IBL is 2 to 3•10^34 cm^−2 s^ −1 and IBL is designed for an integrated luminosity of 700 fb^−1 . This corresponds to an expected fluence of 5 • 10^15 1 MeV n_eqcm^−2 and a total ionizing dose of 250 MRad. In order to cope with these requirements, two new module concepts are under investigation, both based on a new front end IC, called FE-I4. This IC was designed as readout chip for future ATLAS Pixel Detectors and its first application will be the IBL. The planar pixel sensor (PPS) based module concept benefits from its well understood design, which is kept as similar as possible to the design...

  10. Inverted hybrid CdSe-polymer solar cells adopting PEDOT:PSS/MoO3 as dual hole transport layers.

    Science.gov (United States)

    Zhu, Leize; Richardson, Beau J; Yu, Qiuming

    2016-02-07

    Inverted CdSe quantum dots (QDs):poly (3-hexylthiophene) (P3HT) organic/inorganic hybrid solar cells (OIHSCs) with the PSS/MoO3 dual hole transport layers (HTLs) showed superior performance over those with a single HTL of PSS or MoO3. The enhanced electron blocking at the active layer/anode interface as well as the prevention of leakage current accounted for the enhancement in the efficiency of the solar cells with the dual HTLs. By adopting the inverted structure and using the dual HTLs, the resistive losses of the CdSe QDs:P3HT hybrid system at high illumination power were effectively prevented. Further study showed the structure of dual HTLs was applicable to the solar cells with CdSe QDs and nanorods (NRs) blended with poly(thienothiophene-co-benzodithiophenes)7-F20 (PTB7-F20).

  11. Conduction band offset engineering in wide-bandgap Ag(In,Ga)Se2 solar cells by hybrid buffer layer

    Science.gov (United States)

    Umehara, Takeshi; Zulkifly, Faris Akira Bin Mohd; Nakada, Kazuyoshi; Yamada, Akira

    2017-08-01

    Ag(In,Ga)Se2 (AIGS) is one of the promising candidates for the top cell absorber in the tandem structure. However, the conversion efficiency of AIGS solar cells is still lower than that required for the top cell. In this study, to improve the conversion efficiency of AIGS solar cells, we controlled the conduction band offset (CBO) at the buffer layer/ZnO and buffer layer/AIGS interfaces. The reduction in interface recombination at the CdS buffer layer/AIGS interface was achieved by introducing a ZnS(O,OH) buffer layer instead of a CdS buffer layer, although the fill factor (FF) decreased markedly because the CBO at the ZnS(O,OH)/ZnO interface prevented the electron flow under a forward bias. We found that the introduction of a CdS/ZnS(O,OH) hybrid buffer layer is efficient in controlling the CBO at both the buffer layer/AIGS and buffer layer/ZnO interfaces and improving the solar cell conversion efficiency.

  12. Multifunctional alumina/titania hybrid blocking layer modified nanocrystalline titania films as efficient photoanodes in dye sensitized solar cells

    Science.gov (United States)

    Wang, Changlei; Yu, Zhenhua; Bu, Chenghao; Liu, Pei; Bai, Sihang; Liu, Chang; Kondamareddy, Kiran Kumar; Sun, Weiwei; Zhan, Kan; Zhang, Kun; Guo, Shishang; Zhao, Xingzhong

    2015-05-01

    A facile way of fabricating efficient blocking layer on mesoporous TiO2 film of dye-sensitized solar cells (DSSCs) is demonstrated here for the first time. Al2O3 and TiO2 are combined together to form a blocking layer. A simple spin coating technique is employed which is a versatile and low-cost method over the atomic layer deposition (ALD) technique. Multifunctional alumina/titania (Al2O3/TiO2) hybrid overlayer is prepared on traditional TiO2 nanocrystalline thin film surface, through sequential deposition of AlCl3·6H2O and TiCl4 precursor solutions followed by sintering at 500 °C for 30 min. Al2O3 effectively plays its role in retarding interfacial recombination of electrons and improving open circuit potential (Voc), while the tiny TiO2 clusters synthesized from TiCl4 treatment act as electron transporting channels to facilitate electron diffusion which leads to enhanced photocurrent (Jsc). Compared to the device without blocking layer, the DSSCs assembled with Al2O3/TiO2 hybrid blocking layer showed improvement in Jsc (from 13.09 mA/cm2 to 16.90 mA/cm2) as well as in Voc (from 0.72 V to 0.73 V) resulting a much better conversion efficiency of 8.60%.

  13. A new route for local probing of inner interactions within a layered double hydroxide/benzene derivative hybrid material.

    Science.gov (United States)

    Fleutot, S; Dupin, J C; Baraille, I; Forano, C; Renaudin, G; Leroux, F; Gonbeau, D; Martinez, H

    2009-05-14

    This paper presents the preparation and characterization of hybrid hydrotalcite-type layered double hydroxides (Zn1-xAlx(OH)2HBSx.nH2O, with x=0.33) where HBS is the 4-phenol sulfonate, with a detailed analysis of the grafting process of this organic entity onto the host lattice. As a set of the usual techniques (XRD, TG-DT/MS, FTIR and 27Al MAS NMR) was used to characterize the hybrid materials, this work focuses on a joint study by X-ray photoelectron spectroscopy and some quantum-calculation modeling in order to highlight the nature of the interactions between the organic and the mineral sub-systems. For the as-prepared hybrid material, the main results lead to a quasi-vertical orientation of the organic molecules within the mineral sheets via H-bond stabilization. By heating the hybrid material up to 200 degrees C, the structure shrinks with the condensation of the organics; the different theoretical modeling done gives an energy-stable situation when a direct attachment of the HBS sulfonate group sets up with the mineral layers, in agreement with the recorded XPS experimental data.

  14. A CORBA server for the Radiation Hybrid DataBase.

    Science.gov (United States)

    Rodriguez-Tomé, P; Helgesen, C; Lijnzaad, P; Jungfer, K

    1997-01-01

    Modern biology depends on a wide range of software interacting with a large number of data sources, varying both in size, complexity and structure. The range of important databases in molecular biology and genetics makes it crucial to overcome the problems which this multiplicity presents. At EMBL-EBI we have started to use CORBA technology to support interoperability between a variety of databases, as well as to facilitate the integration of tools that access these databases. Within the Radiation Hybrid DataBase project we are confronted daily with the interoperation and linking issues. In this paper we present a CORBA infrastructure implemented to access the Radiation Hybrid DataBase.

  15. 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.

  16. Multifunctional Inverse Opal-Like TiO2 Electron Transport Layer for Efficient Hybrid Perovskite Solar Cells.

    Science.gov (United States)

    Chen, Xiao; Yang, Shuang; Zheng, Yi Chu; Chen, Ying; Hou, Yu; Yang, Xiao Hua; Yang, Hua Gui

    2015-09-01

    A novel multifunctional inverse opal-like TiO2 electron transport layer (IOT-ETL) is designed to replace the traditional compact layer and mesoporous scaffold layer in perovskite solar cells (PSCs). Improved light harvesting efficiency and charge transporting performance in IOT-ETL based PSCs yield high power conversion efficiency of 13.11%.

  17. Substituted Polyfluorene-Based Hole Transport Layer with Tunable Solubility

    OpenAIRE

    Craciun, N. I.; Wildeman, J.; Blom, P. W. M.

    2010-01-01

    We report on the synthesis and electrical characterization of polyfluorene-triarylamine-based hole transport layers (HTLs). The solubility of the HTL can be tuned by adjustment of the chemical structure without loss of the charge transport properties. Double-layer polymer light-emitting diodes are constructed with an HTL that is not soluble in toluene at room temperature, combined with a poly(p-phenylene vinylene) (PPV)-derivative-based light-emitting layer. The addition of the HTL enhances t...

  18. Conceptual design of distillation-based hybrid separation processes.

    Science.gov (United States)

    Skiborowski, Mirko; Harwardt, Andreas; Marquardt, Wolfgang

    2013-01-01

    Hybrid separation processes combine different separation principles and constitute a promising design option for the separation of complex mixtures. Particularly, the integration of distillation with other unit operations can significantly improve the separation of close-boiling or azeotropic mixtures. Although the design of single-unit operations is well understood and supported by computational methods, the optimal design of flowsheets of hybrid separation processes is still a challenging task. The large number of operational and design degrees of freedom requires a systematic and optimization-based design approach. To this end, a structured approach, the so-called process synthesis framework, is proposed. This article reviews available computational methods for the conceptual design of distillation-based hybrid processes for the separation of liquid mixtures. Open problems are identified that must be addressed to finally establish a structured process synthesis framework for such processes.

  19. Synthesis and application of virus-based hybrid nanomaterials.

    Science.gov (United States)

    Lee, Sang-Yup; Lim, Jung-Sun; Harris, Michael T

    2012-01-01

    A virus is a nanoscaled biomolecular substance composed of genes, protecting capsid proteins, and envelopes. The nanoscale dimensions and surface functionalities of virions have been exploited to attract and assemble inorganic and organic materials to produce functional nanomaterials with large surface areas. Genetic modifications of virus capsid proteins lead to the selective deposition and controlled growth of inorganic substances producing organized virus-based hybrid materials. Due to these properties, viruses hold promise for development as platforms for the creation of hybrid materials with multiple functionalities. This article reviews the characteristics of commonly used viruses and their fabrication into virus-based hybrid materials that have been applied in engineering applications such as nanowires and catalysts. Copyright © 2011 Wiley Periodicals, Inc.

  20. Vehicle Sideslip Angle Estimation Based on Hybrid Kalman Filter

    Directory of Open Access Journals (Sweden)

    Jing Li

    2016-01-01

    Full Text Available Vehicle sideslip angle is essential for active safety control systems. This paper presents a new hybrid Kalman filter to estimate vehicle sideslip angle based on the 3-DoF nonlinear vehicle dynamic model combined with Magic Formula tire model. The hybrid Kalman filter is realized by combining square-root cubature Kalman filter (SCKF, which has quick convergence and numerical stability, with square-root cubature based receding horizon Kalman FIR filter (SCRHKF, which has robustness against model uncertainty and temporary noise. Moreover, SCKF and SCRHKF work in parallel, and the estimation outputs of two filters are merged by interacting multiple model (IMM approach. Experimental results show the accuracy and robustness of the hybrid Kalman filter.

  1. Novel hybrid materials based on the vanadium oxide nanobelts

    Science.gov (United States)

    Zabrodina, G. S.; Makarov, S. G.; Kremlev, K. V.; Yunin, P. A.; Gusev, S. A.; Kaverin, B. S.; Kaverina, L. B.; Ketkov, S. Yu.

    2016-04-01

    Novel hybrid materials based on zinc phthalocyanine and nanostructured vanadium oxides have attracted extensive attention for the development of academic research and innovative industrial applications such as flexible electronics, optical sensors and heterogeneous catalysts. Vanadium oxides nanobelts were synthesized via a hydrothermal treatment V2O5·nH2O gel with surfactants (TBAB, CTAB) used as structure-directing agents, where CTAB - cetyltrimethylammonium bromide, TBAB - tetrabutylammonium bromide. Hybrid materials were prepared decoration of (CTA)0.33V2O5 flexible nanobelts with cationic zinc phthalocyanine by the ion-exchange route. Investigations of the thermal stability, morphologies and structures of the (CTA)0.33V2O5, (TBA)0.16V2O5 nanobelts and zinc phthalocyanine exchange product were carried out. The hybrid materials based on the nanostructured vanadium oxide and zinc phthalocyanine were tested as photocatalysts for oxidation of citronellol and 2-mercaptoethanol by dioxygen.

  2. Evaluation of matrix metalloproteinase and cysteine cathepsin activity in dentin hybrid layer by gelatin zymography.

    Science.gov (United States)

    Mahalaxmi, Sekar; Madhubala, Manavalan Madhana; Jayaraman, Mahendran; Sathyakumar, Shanmugasundaram

    2016-01-01

    The aim of this study was to comparatively assess the gelatinolytic activity of matrix metalloproteinases(MMPs) and Cysteine Cathepsins (CCs) in the adhesive interface using etch and rinse adhesive at different time intervals using zymographic technique. Twenty freshly extracted non-carious human third molars were used in this study. Occlusal surfaces were ground flat and 1mm thick horizontal dentin slabs were obtained from each tooth using a diamond disc. The dentin surface was polished with 600-grit silicon-carbide paper. Five out of 20 samples were directly pulverized. In the remaining fifteen samples, the dentin was etched and adhesive was applied and light cured according to the manufacturer's instructions. A 1mm thick flowable composite was build up and light cured. Bonded specimens were cut vertically into 3 to 4 dentin slabs by means of diamond disc to expose the adhesive/dentin interfaces. These were then ground down to 500 µm thick resin-dentin interface using a hard tissue microtome. These sections were then pulverised into powder. Following this, every five samples were subjected to zymographic analysis after 1 day, 7 days and 21 days. Zymograms showed clear, thicker bands on all three isoforms in the etched samples compared to control samples at 1st and 7th day intervals and became inactive at 21st day for all three isoforms. MMP 9 activity was relatively higher when compared to CCs and MMP 2. Etch and rinse adhesive activated MMPs and CCs within the hybrid layer that remained active till 7th day and no gelatinolytic activity was found on 21st day and MMPs are more active compared to CCs and MMP-2.

  3. Highly stable layered double hydroxide colloids: a direct aqueous synthesis route from hybrid polyion complex micelles.

    Science.gov (United States)

    Layrac, Géraldine; Destarac, Mathias; Gérardin, Corine; Tichit, Didier

    2014-08-19

    Aqueous suspensions of highly stable Mg/Al layered double hydroxide (LDH) nanoparticles were obtained via a direct and fully colloidal route using asymmetric poly(acrylic acid)-b-poly(acrylamide) (PAA-b-PAM) double hydrophilic block copolymers (DHBCs) as growth and stabilizing agents. We showed that hybrid polyion complex (HPIC) micelles constituted of almost only Al(3+) were first formed when mixing solutions of Mg(2+) and Al(3+) cations and PAA3000-b-PAM10000 due to the preferential complexation of the trivalent cations. Then mineralization performed by progressive hydroxylation with NaOH transformed the simple DHBC/Al(3+) HPIC micelles into DHBC/aluminum hydroxide colloids, in which Mg(2+) ions were progressively introduced upon further hydroxylation leading to the Mg-Al LDH phase. The whole process of LDH formation occurred then within the confined environment of the aqueous complex colloids. The hydrodynamic diameter of the DHBC/LDH colloids could be controlled: it decreased from 530 nm down to 60 nm when the metal complexing ratio R (R = AA/(Mg + Al)) increased from 0.27 to 1. This was accompanied by a decrease of the average size of individual LDH particles as R increased (for example from 35 nm at R = 0.27 down to 17 nm at R = 0.33), together with a progressive favored intercalation of polyacrylate rather than chloride ions in the interlayer space of the LDH phase. The DHBC/LDH colloids have interesting properties for biomedical applications, that is, high colloidal stability as a function of time, stability in phosphate buffered saline solution, as well as the required size distribution for sterilization by filtration. Therefore, they could be used as colloidal drug delivery systems, especially for hydrosoluble negatively charged drugs.

  4. Structural, optical, and adsorption properties of ZnO(2)/poly(acrylic acid) hybrid thin porous films prepared by ionic strength controlled layer-by-layer method.

    Science.gov (United States)

    Pál, Edit; Sebok, Dániel; Hornok, Viktória; Dékány, Imre

    2009-04-01

    ZnO(2)/poly(acrylic acid) sandwich structures were prepared by layer-by-layer (LbL) self-assembly. The structure and optical behavior of the hybrid films were controlled by changing the surface charge and conformation of the poly(acrylic acid). The buildup of the films was followed by UV-vis absorption and reflection spectroscopy, atomic force microscopy (AFM), X-ray diffraction (XRD), and quartz crystal microbalance (QCM) measurements. It was found that the ionic strength of the polymer solution had a great influence on the film thickness which, in turn, affected the optical properties. The water vapor adsorption isotherms of the films determined by QCM showed an adsorption hysteresis characteristic of porous thin layer structures. The adsorption of water molecules inside the films changed the effective refractive index resulting in a change of the reflection properties. This phenomenon is shown to be exploited for the application of the films as optical sensors. The polarizability of water molecules in the adsorption layer was also determined. It was found that polarization of water molecules in the adsorption layer is much lower than in the liquid water when the surface coverage (Theta) is low.

  5. Optical Properties of Hybrid Inorganic/Organic Thin Film Encapsulation Layers for Flexible Top-Emission Organic Light-Emitting Diodes.

    Science.gov (United States)

    An, Jae Seok; Jang, Ha Jun; Park, Cheol Young; Youn, Hongseok; Lee, Jong Ho; Heo, Gi-Seok; Choi, Bum Ho; Lee, Choong Hun

    2015-10-01

    Inorganic/organic hybrid thin film encapsulation layers consist of a thin Al2O3 layer together with polymer material. We have investigated optical properties of thin film encapsulation layers for top-emission flexible organic light-emitting diodes. The transmittance of hybrid thin film encapsulation layers and the electroluminescent spectrum of organic light-emitting diodes that were passivated by hybrid organic/inorganic thin film encapsulation layers were also examined as a function of the thickness of inorganic Al203 and monomer layers. The number of interference peaks, their intensity, and their positions in the visible range can be controlled by varying the thickness of inorganic Al2O3 layer. On the other hand, changing the thickness of monomer layer had a negligible effect on the optical properties. We also verified that there is a trade-off between transparency in the visible range and the permeation of water vapor in hybrid thin film encapsulation layers. As the number of dyads decreased, optical transparency improved while the water vapor permeation barrier was degraded. Our study suggests that, in top-emission organic light-emitting diodes, the thickness of each thin film encapsulation layer, in particular that of the inorganic layer, and the number of dyads should be controlled for highly efficient top-emission flexible organic light-emitting diodes.

  6. A Hybrid Architecture for Web-based Expert Systems

    OpenAIRE

    Neil Dunstan

    2012-01-01

    A recent technique is to represent the knowledge base of an expert system in XML format. XML parsers are then used to convert XML data into expert system language code. The code is executed or interpreted when providing responses to user queries. Web-based expert system (WBES) architectures may be characterized according to where the application knowledge base resides. Applications of both client and server-sided WBES architectures appear in the literature. A hybrid architecture is proposed w...

  7. Surface density dependence of PCR amplicon hybridization on PNA/DNA probe layers

    DEFF Research Database (Denmark)

    Yao, Danfeng; Kim, Junyoung; Yu, Fang

    2005-01-01

    at an intermediate sodium concentration (approximately 100 mM). These effects were mainly ascribed to the electrostatic cross talk among the hybridized DNA molecules and the secondary structure of PCR amplicons. For the negatively charged DNA probes, the hybridization reaction was subjected additionally to the DNA...

  8. A 3D hybrid grid generation technique and a multigrid/parallel algorithm based on anisotropic agglomeration approach

    Institute of Scientific and Technical Information of China (English)

    Zhang Laiping; Zhao Zhong; Chang Xinghua; He Xin

    2013-01-01

    A hybrid grid generation technique and a multigrid/parallel algorithm are presented in this paper for turbulence flow simulations over three-dimensional (3D) complex geometries.The hybrid grid generation technique is based on an agglomeration method of anisotropic tetrahedrons.Firstly,the complex computational domain is covered by pure tetrahedral grids,in which anisotropic tetrahedrons are adopted to discrete the boundary layer and isotropic tetrahedrons in the outer field.Then,the anisotropic tetrahedrons in the boundary layer are agglomerated to generate prismatic grids.The agglomeration method can improve the grid quality in boundary layer and reduce the grid quantity to enhance the numerical accuracy and efficiency.In order to accelerate the convergence history,a multigrid/parallel algorithm is developed also based on anisotropic agglomeration approach.The numerical results demonstrate the excellent accelerating capability of this multigrid method.

  9. Route-Based Control of Hybrid Electric Vehicles: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gonder, J. D.

    2008-01-01

    Today's hybrid electric vehicle controls cannot always provide maximum fuel savings over all drive cycles. Route-based controls could improve HEV fuel efficiency by 2%-4% and help save nearly 6.5 million gallons of fuel annually.

  10. Controlled formation of calcium-phosphate-based hybrid mesocrystals by organic-inorganic co-assembly.

    Science.gov (United States)

    Zhai, Halei; Chu, Xiaobin; Li, Li; Xu, Xurong; Tang, Ruikang

    2010-11-01

    An understanding of controlled formation of biomimetic mesocrystals is of great importance in materials chemistry and engineering. Here we report that organic-inorganic hybrid plates and even mesocrystals can be conveniently synthesized using a one-pot reaction in a mixed system of protein (bovine serum albumin (BSA)), surfactant (sodium bis(2-ethylhexyl) sulfosuccinate (AOT)) and supersaturated calcium phosphate solution. The morphologies of calcium-phosphate-based products are analogous to the general inorganic crystals but they have abnormal and interesting substructures. The hybrids are constructed by the alternate stacking of organic layer (thickness of 1.31 nm) and well-crystallized inorganic mineral layer (thickness of 2.13 nm) at the nanoscale. Their morphologies (spindle, rhomboid and round) and sizes (200 nm-2 μm) can be tuned gradually by changing BSA, AOT and calcium phosphate concentrations. This modulation effect can be explained by a competition between the anisotropic and isotropic assembly of the ultrathin plate-like units. The anisotropic assembly confers mesocrystal characteristics on the hybrids while the round ones are the results of isotropic assembly. However, the basic lamellar organic-inorganic substructure remains unchanged during the hybrid formation, which is a key factor to ensure the self-assembly from molecule to micrometre scale. A morphological ternary diagram of BSA-AOT-calcium phosphate is used to describe this controlled formation process, providing a feasible strategy to prepare the required materials. This study highlights the cooperative effect of macromolecule (frame structure), small biomolecule (binding sites) and mineral phase (main component) on the generation and regulation of biomimetic hybrid mesocrystals.

  11. Self-assembled gold nanochains hybrid based on insulin fibrils

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Longgai; Gao Faming, E-mail: fmgao@ysu.edu.cn [Yanshan University, Department of Applied Chemistry (China)

    2012-05-15

    We reported a facile method for preparing self-assembly gold nanochains by using insulin fibrils as biotemplate in aqueous environment. The gold nanochains hybrid nanostructures, which are insulin fibrils coated by gold nanoparticles, can be fabricated by simply reducing the salt precursors using DMAB. By increasing the molar ratio between salt precursors and insulin, denser hybrid nanochains can be obtained, meanwhile the mean diameter of gold nanoparticles is changing from 8 to 10 nm and then to 12 nm. The fabricated gold nanochains hybrid had helix structure, which was confirmed by circular dichroism spectra. The hybrid nanostructures were also investigated by transmission electron microscope, atomic force microscope, Fourier transform infrared spectra, and UV-Visible spectroscopy. As the wire-like structure become denser, the suspensions show color-changing, corresponding to the surface plasmon resonance red shift, which is attributed to the increasing mean size of nanoparticles. Based on the characterizations, a hypothetic mechanism was suggested to describe the formation processing of hybrid gold nanochains.

  12. Graphene based nanocomposite hybrid electrodes for supercapacitors

    Science.gov (United States)

    Aphale, Ashish N.

    There is an unmet need to develop high performance energy storage systems (ESS), capable of storing energy from both renewable and non-renewable sources to meet the current energy crisis and depletion of non-renewable sources. Amongst many available ESS, supercapacitors (ECs) are the most promising because they exhibit a high charge/discharge rate and power density, along with a long cycle life. The possibility of exploring the use of atomically thin carbon allotropes like graphene, carbon nanotubes (CNTs) and electrically conducting polymers (ECPs) such as polypyrrole (PPy) has been studied as a high performance conducting electrodes in supercapacitor application. A novel templated sustainable nanocomposite electrode has been fabricated using cellulose extracted from Cladophora c. aegagropila algae as component of the assembled supercapacitor device which later has been transitioned to a unique template-less freestanding nanocomposite supercapacitor electrode. The specific capacitance of polypyrrole-graphene-cellulose nanocomposite as calculated from cyclic voltammetry curve is 91.5 F g -1 at the scan rate 50 m Vs-1 in the presence of 1M NaCl electrolyte. The open circuit voltage of the device with polypyrrole -graphene-cellulose electrode was found to be around 225 m V and that of the polypyrrole -cellulose device is only 53 m V without the presence of graphene in the nanocomposite electrode. Understanding the fundamentals by fabricating template nanocomposite electrode, it led to fabricate a unique nanocomposite template-less freestanding film which comprises of polypyrrole-graphene-CNT hybrid. Various experiments have been performed using different electrolytes such ascorbic acid, sodium sulfate and sulfuric acid in different scan rates. The specific capacitance of polypyrrole-graphene-CNT nanocomposite with 0.1 wt% of graphene-CNT, as calculated from cyclic voltammetry curve is 450 F g-1 at the scan rate 5 m V s-1. For the first time a nanofibrous membrane has

  13. Unique Room Temperature Light Emitting Diode Based on 2D Hybrid Organic-Inorganic Low Dimensional Perovskite Semiconductor

    CERN Document Server

    Vassilakopoulou, Anastasia; Koutselas, Ioannis

    2016-01-01

    Room temperature single layer light emitting diode(LED), based on a two dimensional hybrid organic-inorganic semiconductor(HOIS), is demonstrated. This simple, low cost excitonic LED operates at low voltages. Such an excitonic device is presented for the first time as functioning at room temperature. The newly introduced class of perovskite LEDs, until now based on 3D perovksite HOIS, is now broadened with the implementation of the 2D HOIS. Novel functionalities can be realized since it is now possible to access the hybrid's 2D semiconductor advantageous properties, such as the increased excitonic peak wavelength tunability, excitonic binding energy and oscillator strength.

  14. S-Layer-Based Nanocomposites for Industrial Applications.

    Science.gov (United States)

    Raff, Johannes; Matys, Sabine; Suhr, Matthias; Vogel, Manja; Günther, Tobias; Pollmann, Katrin

    This chapter covers the fundamental aspects of bacterial S-layers: what are S-layers, what is known about them, and what are their main features that makes them so interesting for the production of nanostructures. After a detailed introduction of the paracrystalline protein lattices formed by S-layer systems in nature the chapter explores the engineering of S-layer-based materials. How can S-layers be used to produce "industry-ready" nanoscale bio-composite materials, and which kinds of nanomaterials are possible (e.g., nanoparticle synthesis, nanoparticle immobilization, and multifunctional coatings)? What are the advantages and disadvantages of S-layer-based composite materials? Finally, the chapter highlights the potential of these innovative bacterial biomolecules for future technologies in the fields of metal filtration, catalysis, and bio-functionalization.

  15. Clinical performance of a hybrid resin composite with and without an intermediate layer of flowable resin composite: a 7-year evaluation

    DEFF Research Database (Denmark)

    van Dijken, Jan W V; Pallesen, Ulla

    2011-01-01

    The objective of this prospective clinical follow up was to evaluate the long term clinical performance of a hybrid resin composite in Class II restorations with and without intermediate layer of flowable resin composite.......The objective of this prospective clinical follow up was to evaluate the long term clinical performance of a hybrid resin composite in Class II restorations with and without intermediate layer of flowable resin composite....

  16. 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.

  17. Event-triggered hybrid control based on multi-Agent systems for Microgrids

    DEFF Research Database (Denmark)

    Dou, Chun-xia; Liu, Bin; Guerrero, Josep M.

    2014-01-01

    of distributed energy resources, thus it is typical hybrid dynamic network. Considering the complex hybrid behaviors, a hierarchical decentralized coordinated control scheme is firstly constructed based on multi-agent sys-tem, then, the hybrid model of the microgrid is built by using differential hybrid Petri...

  18. Inorganic-organic hybrid coatings on stainless steel by layer-by-layer deposition and surface-initiated atom-transfer-radical polymerization for combating biocorrosion.

    Science.gov (United States)

    Yuan, S J; Pehkonen, S O; Ting, Y P; Neoh, K G; Kang, E T

    2009-03-01

    To improve the biocorrosion resistance of stainless steel (SS) and to confer the bactericidal function on its surface for inhibiting bacterial adhesion and biofilm formation, well-defined inorganic-organic hybrid coatings, consisting of the inner compact titanium oxide multilayers and outer dense poly(vinyl-N-hexylpyridinium) brushes, were successfully developed. Nanostructured titanium oxide multilayer coatings were first built up on the SS substrates via the layer-by-layer sol-gel deposition process. The trichlorosilane coupling agent, containing the alkyl halide atom-transfer-radical polymerization (ATRP) initiator, was subsequently immobilized on the titanium oxide coatings for surface-initiated ATRP of 4-vinylpyridine (4VP). The pyridium nitrogen moieties of the covalently immobilized 4VP polymer, or P(4VP), brushes were quaternized with hexyl bromide to produce a high concentration of quaternary ammonium salt on the SS surfaces. The excellent antibacterial efficiency of the grafted polycations, poly(vinyl-N-pyridinium bromide), was revealed by viable cell counts and atomic force microscopy images of the surface. The effectiveness of the hybrid coatings in corrosion protection was verified by the Tafel plot and electrochemical impedance spectroscopy measurements.

  19. Hybrid Recommender System Based on Personal Behavior Mining

    OpenAIRE

    Fang, Zhiyuan; Zhang, Lingqi; Chen, Kun

    2016-01-01

    Recommender systems are mostly well known for their applications in e-commerce sites and are mostly static models. Classical personalized recommender algorithm includes item-based collaborative filtering method applied in Amazon, matrix factorization based collaborative filtering algorithm from Netflix, etc. In this article, we hope to combine traditional model with behavior pattern extraction method. We use desensitized mobile transaction record provided by T-mall, Alibaba to build a hybrid ...

  20. Improved performance of Li-ion cells under pulsed load using double-layer capacitors in a hybrid circuit mode

    Energy Technology Data Exchange (ETDEWEB)

    ROTH,EMANUEL P.; NAGASUBRAMANIAN,GANESAN

    2000-02-07

    Electrical characteristics of hybrid power sources consisting of Li-ion cells and double-layer capacitors were studied at 25 C and {minus}20 C. The cells were initially evaluated for pulse performance and then measured in hybrid modes of operation where they were coupled with the high-power capacitors. Cells manufactured by Panasonic measured at 25 C delivered full capacities of 0.76 Ah for pulses up to 3A and cells from A and T delivered full capacities of 0.73 Ah for pulses up to 4A. Measured cell resistances were 0.15 ohms and 0.12 ohms, respectively. These measurements were repeated at {minus}20 C. Direct coupling of the cells and capacitors (coupled hybrid) using 10F Panasonic capacitors in a 8F series/parallel combination extended the full capacity pulse limits (3.0V threshold) to 5.6A for the Panasonic cells and to 9A for the A and T cells. A similar arrangement using 100F capacitors from Elna in a 60F combination increased the Panasonic cell limit to 10 A. Operation in an uncoupled hybrid mode using uncoupled cell/capacitor discharge allowed fill cell capacity usage at 25 C up to the capacitor discharge limit and showed a factor of 5 improvement in delivered capacity at {minus}20 C.

  1. Engineering spin propagation across a hybrid organic/inorganic interface using a polar layer.

    Science.gov (United States)

    Schulz, L; Nuccio, L; Willis, M; Desai, P; Shakya, P; Kreouzis, T; Malik, V K; Bernhard, C; Pratt, F L; Morley, N A; Suter, A; Nieuwenhuys, G J; Prokscha, T; Morenzoni, E; Gillin, W P; Drew, A J

    2011-01-01

    Spintronics has shown a remarkable and rapid development, for example from the initial discovery of giant magnetoresistance in spin valves to their ubiquity in hard-disk read heads in a relatively short time. However, the ability to fully harness electron spin as another degree of freedom in semiconductor devices has been slower to take off. One future avenue that may expand the spintronic technology base is to take advantage of the flexibility intrinsic to organic semiconductors (OSCs), where it is possible to engineer and control their electronic properties and tailor them to obtain new device concepts. Here we show that we can control the spin polarization of extracted charge carriers from an OSC by the inclusion of a thin interfacial layer of polar material. The electric dipole moment brought about by this layer shifts the OSC highest occupied molecular orbital with respect to the Fermi energy of the ferromagnetic contact. This approach allows us full control of the spin band appropriate for charge-carrier extraction, opening up new spintronic device concepts for future exploitation.

  2. Novel hybrid materials based on the vanadium oxide nanobelts

    Energy Technology Data Exchange (ETDEWEB)

    Zabrodina, G.S., E-mail: kudgs@mail.ru [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation); Makarov, S.G.; Kremlev, K.V. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation); Yunin, P.A.; Gusev, S.A. [Institute for Physics of Microstructures Russian Academy of Sciences, Nizhny Novgorod 603087 (Russian Federation); Kaverin, B.S.; Kaverina, L.B. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Ketkov, S.Yu. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation)

    2016-04-15

    Graphical abstract: - Highlights: • Flat and curved vanadium oxide nanobelts have been synthesized. • Hybrid material was prepared via decoration of flexible nanobelts with zinc phthalocyanine. • Investigations of the thermal stability, morphologies and structures were carried out. - Abstract: Novel hybrid materials based on zinc phthalocyanine and nanostructured vanadium oxides have attracted extensive attention for the development of academic research and innovative industrial applications such as flexible electronics, optical sensors and heterogeneous catalysts. Vanadium oxides nanobelts were synthesized via a hydrothermal treatment V{sub 2}O{sub 5}·nH{sub 2}O gel with surfactants (TBAB, CTAB) used as structure-directing agents, where CTAB – cetyltrimethylammonium bromide, TBAB – tetrabutylammonium bromide. Hybrid materials were prepared decoration of (CTA){sub 0.33}V{sub 2}O{sub 5} flexible nanobelts with cationic zinc phthalocyanine by the ion-exchange route. Investigations of the thermal stability, morphologies and structures of the (CTA){sub 0.33}V{sub 2}O{sub 5}, (TBA){sub 0.16}V{sub 2}O{sub 5} nanobelts and zinc phthalocyanine exchange product were carried out. The hybrid materials based on the nanostructured vanadium oxide and zinc phthalocyanine were tested as photocatalysts for oxidation of citronellol and 2-mercaptoethanol by dioxygen.

  3. Substituted polyfluorene-based hole transport layer with tunable solubility

    NARCIS (Netherlands)

    Craciun, N.I.; Wildeman, J.; Blom, P.W.M.

    2010-01-01

    We report on the synthesis and electrical characterization of polyfluorene-triarylamine-based hole transport layers (HTLs). The solubility of the HTL can be tuned by adjustment of the chemical structure without loss of the charge transport properties. Double-layer polymer light-emitting diodes are c

  4. Substituted Polyfluorene-Based Hole Transport Layer with Tunable Solubility

    NARCIS (Netherlands)

    Craciun, N. I.; Wildeman, J.; Blom, P. W. M.

    2010-01-01

    We report on the synthesis and electrical characterization of polyfluorene-triarylamine-based hole transport layers (HTLs). The solubility of the HTL can be tuned by adjustment of the chemical structure without loss of the charge transport properties. Double-layer polymer light-emitting diodes are c

  5. A method of layer-by-layer gold nanoparticle hybridization in a quartz crystal microbalance DNA sensing system used to detect dengue virus

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S-H; Chuang, Y-C; Lu, Y-C; Lin, H-C; Yang, Y-L; Lin, C-S [Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China)], E-mail: lincs@mail.nctu.edu.tw

    2009-05-27

    Dengue virus (DENV) is nowadays the most important arthropod-spread virus affecting humans existing in more than 100 countries worldwide. A rapid and sensitive detection method for the early diagnosis of infectious dengue virus urgently needs to be developed. In the present study, a circulating-flow quartz crystal microbalance (QCM) biosensing method combining oligonucleotide-functionalized gold nanoparticles (i.e. AuNP probes) used to detect DENV has been established. In the DNA-QCM method, two kinds of specific AuNP probes were linked by the target sequences onto the QCM chip to amplify the detection signal, i.e. oscillatory frequency change ({delta}F) of the QCM sensor. The target sequences amplified from the DENV genome act as a bridge for the layer-by-layer AuNP probes' hybridization in the method. Besides being amplifiers of the detection signal, the specific AuNP probes used in the DNA-QCM method also play the role of verifiers to specifically recognize their target sequences in the detection. The effect of four AuNP sizes on the layer-by-layer hybridization has been evaluated and it is found that 13 nm AuNPs collocated with 13 nm AuNPs showed the best hybridization efficiency. According to the nanoparticle application, the DNA-QCM biosensing method was able to detect dengue viral RNA in virus-contaminated serum as plaque titers being 2 PFU ml{sup -1} and a linear correlation (R{sup 2} = 0.987) of {delta}F versus virus titration from 2 x 10{sup 0} to 2 x 10{sup 6} PFU ml{sup -1} was found. The sensitivity and specificity of the present DNA-QCM method with nanoparticle technology showed it to be comparable to the fluorescent real-time PCR methods. Moreover, the method described herein was shown to not require expensive equipment, was label-free and highly sensitive.

  6. Efficiency Enhancement of Hybrid Perovskite Solar Cells with MEH-PPV Hole-Transporting Layers

    Science.gov (United States)

    Chen, Hsin-Wei; Huang, Tzu-Yen; Chang, Ting-Hsiang; Sanehira, Yoshitaka; Kung, Chung-Wei; Chu, Chih-Wei; Ikegami, Masashi; Miyasaka, Tsutomu; Ho, Kuo-Chuan

    2016-01-01

    In this study, hybrid perovskite solar cells are fabricated using poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and poly(3-hexylthiophene-2,5-diyl) (P3HT) as dopant-free hole-transporting materials (HTMs), and two solution processes (one- and two-step methods, respectively) for preparing methylammonium lead iodide perovskite. By optimizing the concentrations and solvents of MEH-PPV solutions, a power conversion efficiency of 9.65% with hysteresis-less performance is achieved, while the device with 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′spirobifluorene (Spiro-OMeTAD) doped with lithium salts and tert-butylpyridine (TBP) exhibits an efficiency of 13.38%. This result shows that non-doped MEH-PPV is a suitable, low-cost HTM for efficient polymer-based perovskite solar cells. The effect of different morphologies of methylammonium lead iodide perovskite on conversion efficiency is also investigated by incident photon-to-electron conversion efficiency (IPCE) curves and electrochemical impedance spectroscopy (EIS). PMID:27698464

  7. Graphene-based transparent electrodes for hybrid solar cells

    Directory of Open Access Journals (Sweden)

    Pengfei eLi

    2014-11-01

    Full Text Available The graphene-based transparent and conductive films were demonstrated to be cost-effective electrodes working in organic-inorganic hybrid Schottky solar cells. Large area graphene films were produced by chemical vapor deposition (CVD on copper foils and transferred onto glass as transparent electrodes. The hybrid solar cell devices consist of solution processed poly (3, 4-ethlenedioxythiophene: poly (styrenesulfonate (PEDOT: PSS which is sandwiched between silicon wafer and graphene electrode. The solar cells based on graphene electrodes, especially those doped with HNO3, has comparable performance to the reference devices using commercial indium tin oxide (ITO. Our work suggests that graphene-based transparent electrode is a promising candidate to replace ITO.

  8. Intelligent Hybrid Cluster Based Classification Algorithm for Social Network Analysis

    Directory of Open Access Journals (Sweden)

    S. Muthurajkumar

    2014-05-01

    Full Text Available In this paper, we propose an hybrid clustering based classification algorithm based on mean approach to effectively classify to mine the ordered sequences (paths from weblog data in order to perform social network analysis. In the system proposed in this work for social pattern analysis, the sequences of human activities are typically analyzed by switching behaviors, which are likely to produce overlapping clusters. In this proposed system, a robust Modified Boosting algorithm is proposed to hybrid clustering based classification for clustering the data. This work is useful to provide connection between the aggregated features from the network data and traditional indices used in social network analysis. Experimental results show that the proposed algorithm improves the decision results from data clustering when combined with the proposed classification algorithm and hence it is proved that of provides better classification accuracy when tested with Weblog dataset. In addition, this algorithm improves the predictive performance especially for multiclass datasets which can increases the accuracy.

  9. Hybrid Recommender System based on Autoencoders

    OpenAIRE

    Strub, Florian; Gaudel, Romaric; Mary, Jérémie

    2016-01-01

    International audience; A standard model for Recommender Systems is the Matrix Completion setting: given partially known matrix of ratings given by users (rows) to items (columns), infer the unknown ratings. In the last decades, few attempts where done to handle that objective with Neural Networks, but recently an architecture based on Autoencoders proved to be a promising approach. In current paper, we enhanced that architecture (i) by using a loss function adapted to input data with missing...

  10. A study of tin oxide as an election injection layer in hybrid polymer light-emitting diodes

    Science.gov (United States)

    Lu, Li Ping; Finlayson, Chris E.; Friend, Richard H.

    2014-12-01

    We investigate the n-type metal oxide tin (IV) oxide (SnO2) as an electron injection and transport layer in hybrid polymer light-emitting diodes. SnO2 is air stable and bio-safe, with high optical transparency and electrical conductivity, and with a deep valence band energy, making it highly suitable for such applications. Results reveal that SnO2 is effective as an electron injecting cathode material when a thin hole-blocking interlayer of Cs2CO3 or Ba(OH)2 is coated on it. Devices are optimized with respect to injection-layer thickness and hole-blocking layer configuration, with high performance metrics (current efficiencies of 20 cd A-1, external quantum efficiencies of 6.5%) being demonstrated in the device with Ba(OH)2 as the inorganic interlayer in the hybrid architecture. Also, we characterize thin films of spray-pyrolysis-deposited SnO2, as compared with the commonly used interlayer material ZnO, in terms of film morphology and interfacial photophysics.

  11. A Hybrid Architecture for Vision-Based Obstacle Avoidance

    Directory of Open Access Journals (Sweden)

    Mehmet Serdar Güzel

    2013-01-01

    Full Text Available This paper proposes a new obstacle avoidance method using a single monocular vision camera as the only sensor which is called as Hybrid Architecture. This architecture integrates a high performance appearance-based obstacle detection method into an optical flow-based navigation system. The hybrid architecture was designed and implemented to run both methods simultaneously and is able to combine the results of each method using a novel arbitration mechanism. The proposed strategy successfully fused two different vision-based obstacle avoidance methods using this arbitration mechanism in order to permit a safer obstacle avoidance system. Accordingly, to establish the adequacy of the design of the obstacle avoidance system, a series of experiments were conducted. The results demonstrate the characteristics of the proposed architecture, and the results prove that its performance is somewhat better than the conventional optical flow-based architecture. Especially, the robot employing Hybrid Architecture avoids lateral obstacles in a more smooth and robust manner than when using the conventional optical flow-based technique.

  12. Breaking and Fixing Origin-Based Access Control in Hybrid Web/Mobile Application Frameworks.

    Science.gov (United States)

    Georgiev, Martin; Jana, Suman; Shmatikov, Vitaly

    2014-02-01

    Hybrid mobile applications (apps) combine the features of Web applications and "native" mobile apps. Like Web applications, they are implemented in portable, platform-independent languages such as HTML and JavaScript. Like native apps, they have direct access to local device resources-file system, location, camera, contacts, etc. Hybrid apps are typically developed using hybrid application frameworks such as PhoneGap. The purpose of the framework is twofold. First, it provides an embedded Web browser (for example, WebView on Android) that executes the app's Web code. Second, it supplies "bridges" that allow Web code to escape the browser and access local resources on the device. We analyze the software stack created by hybrid frameworks and demonstrate that it does not properly compose the access-control policies governing Web code and local code, respectively. Web code is governed by the same origin policy, whereas local code is governed by the access-control policy of the operating system (for example, user-granted permissions in Android). The bridges added by the framework to the browser have the same local access rights as the entire application, but are not correctly protected by the same origin policy. This opens the door to fracking attacks, which allow foreign-origin Web content included into a hybrid app (e.g., ads confined in iframes) to drill through the layers and directly access device resources. Fracking vulnerabilities are generic: they affect all hybrid frameworks, all embedded Web browsers, all bridge mechanisms, and all platforms on which these frameworks are deployed. We study the prevalence of fracking vulnerabilities in free Android apps based on the PhoneGap framework. Each vulnerability exposes sensitive local resources-the ability to read and write contacts list, local files, etc.-to dozens of potentially malicious Web domains. We also analyze the defenses deployed by hybrid frameworks to prevent resource access by foreign-origin Web content

  13. Breaking and Fixing Origin-Based Access Control in Hybrid Web/Mobile Application Frameworks

    Science.gov (United States)

    Georgiev, Martin; Jana, Suman; Shmatikov, Vitaly

    2014-01-01

    Hybrid mobile applications (apps) combine the features of Web applications and “native” mobile apps. Like Web applications, they are implemented in portable, platform-independent languages such as HTML and JavaScript. Like native apps, they have direct access to local device resources—file system, location, camera, contacts, etc. Hybrid apps are typically developed using hybrid application frameworks such as PhoneGap. The purpose of the framework is twofold. First, it provides an embedded Web browser (for example, WebView on Android) that executes the app's Web code. Second, it supplies “bridges” that allow Web code to escape the browser and access local resources on the device. We analyze the software stack created by hybrid frameworks and demonstrate that it does not properly compose the access-control policies governing Web code and local code, respectively. Web code is governed by the same origin policy, whereas local code is governed by the access-control policy of the operating system (for example, user-granted permissions in Android). The bridges added by the framework to the browser have the same local access rights as the entire application, but are not correctly protected by the same origin policy. This opens the door to fracking attacks, which allow foreign-origin Web content included into a hybrid app (e.g., ads confined in iframes) to drill through the layers and directly access device resources. Fracking vulnerabilities are generic: they affect all hybrid frameworks, all embedded Web browsers, all bridge mechanisms, and all platforms on which these frameworks are deployed. We study the prevalence of fracking vulnerabilities in free Android apps based on the PhoneGap framework. Each vulnerability exposes sensitive local resources—the ability to read and write contacts list, local files, etc.—to dozens of potentially malicious Web domains. We also analyze the defenses deployed by hybrid frameworks to prevent resource access by foreign

  14. Pipe flow of pumping wet shotcrete based on lubrication layer

    National Research Council Canada - National Science Library

    Chen, Lianjun; Liu, Guoming; Cheng, Weimin; Pan, Gang

    2016-01-01

    .... The paper studied the pipe flow law of wet shotcrete based on lubrication layer by build the experimental pumping circuit of wet shotcrete that can carry out a number of full-scale pumping tests...

  15. Research on Modulation Strategies Based on Multilevel Inverter Universal Hybrid Topology

    Institute of Scientific and Technical Information of China (English)

    Zhou Jinghua; Su Yanmin; Shen Chuanwen; Zhang Lin

    2005-01-01

    Based on multi-module-cascaded inverter topology, this study presented a universal multilevel inverter hybrid topology and unified the researches on multilevel inverter topology. According to the freedom of this universal topology, several new hybrid topologies were constructed. Also, based on conventional modulation strategies- multi-carrier SPWM (Sinusoidal Pulse Width Modulation), hybrid modulation strategies were introduced corresponding to hybrid topologies, and a multilevel SVPWM (Space Vector Pulse Width Modulation) technique based on phase-shifted theory was naturally produced. Simulation and experiment results prove that hybrid topologies and corresponding modulation strategies are valid, which lay a foundation for practical application of hybrid multilevel inverter topologies.

  16. Layered inorganic-organic hybrid with talc-like structure for cation removal at the solid/liquid interface

    Energy Technology Data Exchange (ETDEWEB)

    Badshah, Syed [Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP (Brazil); Airoldi, Claudio, E-mail: airoldi@iqm.unicamp.br [Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP (Brazil)

    2013-01-20

    Graphical abstract: A lamellar inorganic-organic hybrid with talc-like structure has been synthesized through a single sol-gel step. Highlights: Black-Right-Pointing-Pointer New silylating agent isolated from acrylamide includes basic centers attached to enlarged chain. Black-Right-Pointing-Pointer Lamellar inorganic-organic talc-like structure has been synthesized through a single sol-gel step. Black-Right-Pointing-Pointer High basal distance accommodates the pendant chain in the cavities only in inclined disposition. Black-Right-Pointing-Pointer The pendant chain sorbs spontaneously and favorable cations as demonstrated by thermodynamic data. - Abstract: A new silylating agent N-((3-(3-(trimethoxysilyl)propylthio)propanamido)methyl)acrylamide synthesized from the reaction of N,N-methylenebisacrylamide and 3-mercaptopropyltrimethoxysilane yielded layered inorganic-organic talc-like magnesium phyllosilicate through the sol-gel process. Elemental analysis data based on sulfur demonstrated incorporation of 2.70 mmol g{sup -1} of organic moiety inside the lamellar cavities and the X-ray diffraction patterns confirmed the talc-like structure with a basal distance of 2.11 nm. Infrared spectroscopy, {sup 13}C and {sup 29}Si NMR in the solid state are in agreement with the presence of organic chains covalently bonded to the inorganic lamellar framework, as also supported by the presence of T{sup n} silicon species. Nitrogen, oxygen and sulfur basic centers sorb divalent lead, copper and cobalt cations with maximum capacity of 5.30, 3.82 and 1.60 mmol g{sup -1}. The thermodynamic data for cation/basic center interactions at the solid/liquid interface were determined through calorimetric titration with exothermic enthalpy, negative Gibbs energy and positive entropy, as expected for spontaneous and favorable reaction conditions.

  17. Hybrid uncertainty-based design optimization and its application to hybrid rocket motors for manned lunar landing

    Directory of Open Access Journals (Sweden)

    Hao Zhu

    2017-04-01

    Full Text Available Design reliability and robustness are getting increasingly important for the general design of aerospace systems with many inherently uncertain design parameters. This paper presents a hybrid uncertainty-based design optimization (UDO method developed from probability theory and interval theory. Most of the uncertain design parameters which have sufficient information or experimental data are classified as random variables using probability theory, while the others are defined as interval variables with interval theory. Then a hybrid uncertainty analysis method based on Monte Carlo simulation and Taylor series interval analysis is developed to obtain the uncertainty propagation from the design parameters to system responses. Three design optimization strategies, including deterministic design optimization (DDO, probabilistic UDO and hybrid UDO, are applied to the conceptual design of a hybrid rocket motor (HRM used as the ascent propulsion system in Apollo lunar module. By comparison, the hybrid UDO is a feasible method and can be effectively applied to the general design of aerospace systems.

  18. A Hybrid Brain-Computer Interface-Based Mail Client

    Directory of Open Access Journals (Sweden)

    Tianyou Yu

    2013-01-01

    Full Text Available Brain-computer interface-based communication plays an important role in brain-computer interface (BCI applications; electronic mail is one of the most common communication tools. In this study, we propose a hybrid BCI-based mail client that implements electronic mail communication by means of real-time classification of multimodal features extracted from scalp electroencephalography (EEG. With this BCI mail client, users can receive, read, write, and attach files to their mail. Using a BCI mouse that utilizes hybrid brain signals, that is, motor imagery and P300 potential, the user can select and activate the function keys and links on the mail client graphical user interface (GUI. An adaptive P300 speller is employed for text input. The system has been tested with 6 subjects, and the experimental results validate the efficacy of the proposed method.

  19. Hybrid Neuro-Fuzzy Classifier Based On Nefclass Model

    Directory of Open Access Journals (Sweden)

    Bogdan Gliwa

    2011-01-01

    Full Text Available The paper presents hybrid neuro-fuzzy classifier, based on NEFCLASS model, which wasmodified. The presented classifier was compared to popular classifiers – neural networks andk-nearest neighbours. Efficiency of modifications in classifier was compared with methodsused in original model NEFCLASS (learning methods. Accuracy of classifier was testedusing 3 datasets from UCI Machine Learning Repository: iris, wine and breast cancer wisconsin.Moreover, influence of ensemble classification methods on classification accuracy waspresented.

  20. Hybrid Fundamental Solution Based Finite Element Method: Theory and Applications

    OpenAIRE

    Changyong Cao; Qing-Hua Qin

    2015-01-01

    An overview on the development of hybrid fundamental solution based finite element method (HFS-FEM) and its application in engineering problems is presented in this paper. The framework and formulations of HFS-FEM for potential problem, plane elasticity, three-dimensional elasticity, thermoelasticity, anisotropic elasticity, and plane piezoelectricity are presented. In this method, two independent assumed fields (intraelement filed and auxiliary frame field) are employed. The formulations for...

  1. 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.

  2. Inkjet-printed zinc-tin-oxide TFTs with a solution-processed hybrid dielectric layer

    Science.gov (United States)

    Jang, Hye-Ryun; Kwack, Young-Jin; Choi, Woon-Seop

    2014-11-01

    Sol-gel TiO2 was synthesized and used as a gate dielectric for oxide thin-film transistors (TFTs). A hybrid gate insulator composed of sol-gel TiO2/thermally-grown SiO2 was applied to the inkjet-printed zinc-tin oxide (ZTO) TFTs for the first time. The electrical properties of an inkjet-printed ZTO TFT with a hybrid gate insulator show a mobility of 0.17 cm2/Vs, an on-to-off current ratio of 5 × 104, a subthreshold slope of 0.8 V/dec, and a threshold voltage of 0.6 V. The hybrid gate insulator for the inkjet-printed ZTO TFT shows a much improved operating voltage and subthreshold slope and a lower mobility compared to the SiO2 gate insulator.

  3. Simulations of ionospheric turbulence produced by HF heating near the upper hybrid layer

    Science.gov (United States)

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

    2016-06-01

    Heating of the ionosphere by high-frequency (HF), ordinary (O) mode electromagnetic waves can excite magnetic field-aligned density striations, associated with upper and lower hybrid turbulence and electron heating. We have used Vlasov simulations in one spatial and two velocity dimensions to study the induced turbulence in the presence of striations when the O-mode pump is mode converted to large-amplitude upper hybrid oscillations trapped in a striation. Parametric processes give rise to upper and lower hybrid turbulence, as well as to large amplitude, short wavelength electron Bernstein waves. The latter excite stochastic electron heating when their amplitudes exceed a threshold for stochasticity, leading to a rapid increase of the electron temperature by several thousands of kelvin. The results have relevance for high-latitude heating experiments.

  4. Electrostatic electron cyclotron instabilities near the upper hybrid layer due to electron ring distributions

    Science.gov (United States)

    Eliasson, B.; Speirs, D. C.; Daldorff, L. K. S.

    2016-09-01

    A theoretical study is presented of the electrostatic electron cyclotron instability involving Bernstein modes in a magnetized plasma. The presence of a tenuous thermal ring distribution in a Maxwellian plasma decreases the frequency of the upper hybrid branch of the electron Bernstein mode until it merges with the nearest lower branch with a resulting instability. The instability occurs when the upper hybrid frequency is somewhat above the third, fourth, and higher electron cyclotron harmonics, and gives rise to a narrow spectrum of waves around the electron cyclotron harmonic nearest to the upper hybrid frequency. For a tenuous cold ring distribution together with a Maxwellian distribution an instability can take place also near the second electron cyclotron harmonic. Noise-free Vlasov simulations are used to assess the theoretical linear growth-rates and frequency spectra, and to study the nonlinear evolution of the instability. The relevance of the results to laboratory and ionospheric heating experiments is discussed.

  5. Wavelet-Based DFT calculations on Massively Parallel Hybrid Architectures

    Science.gov (United States)

    Genovese, Luigi

    2011-03-01

    In this contribution, we present an implementation of a full DFT code that can run on massively parallel hybrid CPU-GPU clusters. Our implementation is based on modern GPU architectures which support double-precision floating-point numbers. This DFT code, named BigDFT, is delivered within the GNU-GPL license either in a stand-alone version or integrated in the ABINIT software package. Hybrid BigDFT routines were initially ported with NVidia's CUDA language, and recently more functionalities have been added with new routines writeen within Kronos' OpenCL standard. The formalism of this code is based on Daubechies wavelets, which is a systematic real-space based basis set. As we will see in the presentation, the properties of this basis set are well suited for an extension on a GPU-accelerated environment. In addition to focusing on the implementation of the operators of the BigDFT code, this presentation also relies of the usage of the GPU resources in a complex code with different kinds of operations. A discussion on the interest of present and expected performances of Hybrid architectures computation in the framework of electronic structure calculations is also adressed.

  6. Electrochemical DNA Hybridization Sensors Based on Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Md. Mahbubur Rahman

    2015-02-01

    Full Text Available Conducting polymers (CPs are a group of polymeric materials that have attracted considerable attention because of their unique electronic, chemical, and biochemical properties. This is reflected in their use in a wide range of potential applications, including light-emitting diodes, anti-static coating, electrochromic materials, solar cells, chemical sensors, biosensors, and drug-release systems. Electrochemical DNA sensors based on CPs can be used in numerous areas related to human health. This review summarizes the recent progress made in the development and use of CP-based electrochemical DNA hybridization sensors. We discuss the distinct properties of CPs with respect to their use in the immobilization of probe DNA on electrode surfaces, and we describe the immobilization techniques used for developing DNA hybridization sensors together with the various transduction methods employed. In the concluding part of this review, we present some of the challenges faced in the use of CP-based DNA hybridization sensors, as well as a future perspective.

  7. Controlled-layer and large-area MoSsub>2sub> films encapsulated Au nanoparticle hybrids for SERS.

    Science.gov (United States)

    Li, Zhen; Jiang, Shouzhen; Huo, Yanyan; Liu, Mei; Yang, Cheng; Zhang, Chao; Liu, Xiaoyun; Sheng, Yingqing; Li, Chonghui; Man, Baoyuan

    2016-11-14

    In this work, a facile and effective method for controlled-layer and large-area MoSsub>2sub> films encapsulated Au nanoparticle hybrids is developed. With accurate Ar plasma treatment time control, the large-area MoSsub>2sub> layers can be obtained from monolayer to trilayer. The fabricated MoSsub>2sub>@Au NPs with higher surface area exhibit excellent Raman enhanced effect for aromatic organic molecules (rhodamine 6G and crystal violet) and achieve the best when the monolayer MoSsub>2sub>@AuNPs was obtained. The limit of detection is found to be as low as 1 × 10-10 M. The MoSsub>2sub>@AuNPs was characterized by SEM, EDS, AFM, Raman spectroscopy, UV-Vis, XRD and HRTEM.

  8. Two-dimensional inorganic–organic hybrid semiconductors composed of double-layered ZnS and monoamines with aromatic and heterocyclic aliphatic rings: Syntheses, structures, and properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Sujing; Li, Jing, E-mail: jingli@rutgers.edu

    2015-04-15

    As an addition to the II–VI based inorganic–organic hybrid semiconductor family, five new two-dimensional (2D) double-layered structures have been synthesized employing monoamines with different aromatic or heterocyclic aliphatic rings. Zn{sub 2}S{sub 2}(bza) (1), Zn{sub 2}S{sub 2}(mbza) (2), Zn{sub 2}S{sub 2}(fbza) (3), Zn{sub 2}S{sub 2}(pca) (4), and Zn{sub 2}S{sub 2}(thfa) (5) (bza=benzylamine, mbza=4-methoxybenzylamine, fbza=4-flurobenzylamine, pca=3-picolylamine, and thfa=tetrahydrofurfurylamine) are prepared by solvothermal reactions and characterized by different analytical methods, including powder X-ray diffraction, optical diffuse reflection, thermogravimetric analysis and photoluminescence spectroscopy. The powder X-ray diffraction patterns show that all five compounds adopt 2D double-layered structures. Optical diffuse reflectance spectra of these compounds suggest that they have notably lower band gaps than those of the similar compounds composed of aliphatic alkyl amines. Their photoluminescence properties and thermal stability are also analyzed. - Graphical abstract: Five new members of two-dimensional double-layered 2D-Zn{sub 2}S{sub 2}(L) (L=Ligand) structures employing monoamines with different aromatic or heterocyclic aliphatic rings have been designed, synthesized, and characterized. - Highlights: • A new sub-family of II-VI based hybrid semiconductors are designed, synthesized, and structurally characterized using amines with aromatic or aliphatic cyclic rings. • These compounds have notably lower band gaps than those made of aliphatic alkyl amines, greatly broadening the range of band gaps of this material family. • They emit strongly with systematically tunable emission intensity and energy.

  9. Medical Image Retrieval Based on Multi-Layer Resampling Template

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-rui; YANG Yun-feng

    2014-01-01

    Medical image application in clinical diagnosis and treatment is becoming more and more widely, How to use a large number of images in the image management system and it is a very important issue how to assist doctors to analyze and diagnose. This paper studies the medical image retrieval based on multi-layer resampling template under the thought of the wavelet decomposition, the image retrieval method consists of two retrieval process which is coarse and fine retrieval. Coarse retrieval process is the medical image retrieval process based on the image contour features. Fine retrieval process is the medical image retrieval process based on multi-layer resampling template, a multi-layer sampling operator is employed to extract image resampling images each layer, then these resampling images are retrieved step by step to finish the process from coarse to fine retrieval.

  10. Papery solar cells based on dielectric/metal hybrid transparent cathode

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Fei; Chen, Zhijian; Xiao, Lixin; Qu, Bo; Gong, Qihuang [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China)

    2010-07-15

    Poly(3-hexylthiophene) (P3HT):1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C{sub 61} (PCBM) photovoltaic devices based on ordinary paper as substrate were fabricated. Au layer deposited on paper by RF magnetron sputtering was used as anode. The hybrid layer of LiF co-evaporated with Al was used for transparent cathode, and the light transmittance could reach to {proportional_to}70%. By optimizing the mass proportion of LiF and Al, we could get the best papery solar cells with the short current density and open circuit voltage 0.1 mA/cm{sup 2} and 0.39 V, respectively. The corresponding power conversion efficiency was measured to be 0.13 permille illuminated with 100 mW/cm{sup 2} air mass 1.5 global (AM 1.5 G) simulated sunlight. (author)

  11. Fluorescent deep-blue and hybrid white emitting devices based on a naphthalene-benzofuran compound

    KAUST Repository

    Yang, Xiaohui

    2013-08-01

    We report the synthesis, photophysics and electrochemical properties of naphthalene-benzofuran compound 1 and its application in organic light emitting devices. Fluorescent deep-blue emitting devices employing 1 as the emitting dopant embedded in 4-4′-bis(9-carbazolyl)-2,2′-biphenyl (CBP) host show the peak external quantum efficiency of 4.5% and Commission Internationale d\\'Énclairage (CIE) coordinates of (0.15, 0.07). Hybrid white devices using fluorescent blue emitting layer with 1 and a phosphorescent orange emitting layer based on an iridium-complex show the peak external quantum efficiency above 10% and CIE coordinates of (0.31, 0.37). © 2013 Published by Elsevier B.V.

  12. Layered Ni(OH)2-Co(OH)2 films prepared by electrodeposition as charge storage electrodes for hybrid supercapacitors

    Science.gov (United States)

    Nguyen, Tuyen; Boudard, Michel; Carmezim, M. João; Montemor, M. Fátima

    2017-01-01

    Consecutive layers of Ni(OH)2 and Co(OH)2 were electrodeposited on stainless steel current collectors for preparing charge storage electrodes of high specific capacity with potential application in hybrid supercapacitors. Different electrodes were prepared consisting on films of Ni(OH)2, Co(OH)2, Ni1/2Co1/2(OH)2 and layered films of Ni(OH)2 on Co(OH)2 and Co(OH)2 on Ni(OH)2 to highlight the advantages of the new architecture. The microscopy studies revealed the formation of nanosheets in the Co(OH)2 films and of particles agglomerates in the Ni(OH)2 films. Important morphological changes were observed in the double hydroxides films and layered films. Film growth by electrodeposition was governed by instantaneous nucleation mechanism. The new architecture composed of Ni(OH)2 on Co(OH)2 displayed a redox response characterized by the presence of two peaks in the cyclic voltammograms, arising from redox reactions of the metallic species present in the layered film. These electrodes revealed a specific capacity of 762 C g−1 at the specific current of 1 A g−1. The hybrid cell using Ni(OH)2 on Co(OH)2 as positive electrode and carbon nanofoam paper as negative electrode display specific energies of 101.3 W h g−1 and 37.8 W h g−1 at specific powers of 0.2 W g−1 and 2.45 W g−1, respectively. PMID:28051143

  13. Layered Ni(OH)2-Co(OH)2 films prepared by electrodeposition as charge storage electrodes for hybrid supercapacitors.

    Science.gov (United States)

    Nguyen, Tuyen; Boudard, Michel; Carmezim, M João; Montemor, M Fátima

    2017-01-04

    Consecutive layers of Ni(OH)2 and Co(OH)2 were electrodeposited on stainless steel current collectors for preparing charge storage electrodes of high specific capacity with potential application in hybrid supercapacitors. Different electrodes were prepared consisting on films of Ni(OH)2, Co(OH)2, Ni1/2Co1/2(OH)2 and layered films of Ni(OH)2 on Co(OH)2 and Co(OH)2 on Ni(OH)2 to highlight the advantages of the new architecture. The microscopy studies revealed the formation of nanosheets in the Co(OH)2 films and of particles agglomerates in the Ni(OH)2 films. Important morphological changes were observed in the double hydroxides films and layered films. Film growth by electrodeposition was governed by instantaneous nucleation mechanism. The new architecture composed of Ni(OH)2 on Co(OH)2 displayed a redox response characterized by the presence of two peaks in the cyclic voltammograms, arising from redox reactions of the metallic species present in the layered film. These electrodes revealed a specific capacity of 762 C g(-1) at the specific current of 1 A g(-1). The hybrid cell using Ni(OH)2 on Co(OH)2 as positive electrode and carbon nanofoam paper as negative electrode display specific energies of 101.3 W h g(-1) and 37.8 W h g(-1) at specific powers of 0.2 W g(-1) and 2.45 W g(-1), respectively.

  14. In Situ Carbonized Cellulose-Based Hybrid Film as Flexible Paper Anode for Lithium-Ion Batteries.

    Science.gov (United States)

    Cao, Shaomei; Feng, Xin; Song, Yuanyuan; Liu, Hongjiang; Miao, Miao; Fang, Jianhui; Shi, Liyi

    2016-01-20

    Flexible free-standing carbonized cellulose-based hybrid film is integrately designed and served both as paper anode and as lightweight current collector for lithium-ion batteries. The well-supported heterogeneous nanoarchitecture is constructed from Li4Ti5O12 (LTO), carbonized cellulose nanofiber (C-CNF) and carbon nanotubes (CNTs) using by a pressured extrusion papermaking method followed by in situ carbonization under argon atmospheres. The in situ carbonization of CNF/CNT hybrid film immobilized with uniform-dispersed LTO results in a dramatic improvement in the electrical conductivity and specific surface area, so that the carbonized paper anode exhibits extraordinary rate and cycling performance compared to the paper anode without carbonization. The flexible, lightweight, single-layer cellulose-based hybrid films after carbonization can be utilized as promising electrode materials for high-performance, low-cost, and environmentally friendly lithium-ion batteries.

  15. Prediction of Silicon-Based Layered Structures for Optoelectronic Applications

    Science.gov (United States)

    Luo, Wei; Ma, Yanming; Gong, Xingao; Xiang, Hongjun; CCMG Team

    2015-03-01

    A method based on the particle swarm optimization (PSO) algorithm is presented to design quasi-two-dimensional (Q2D) materials. With this development, various single-layer and bi-layer materials in C, Si, Ge, Sn, and Pb were predicted. A new Si bi-layer structure is found to have a much-favored energy than the previously widely accepted configuration. Both single-layer and bi-layer Si materials have small band gaps, limiting their usages in optoelectronic applications. Hydrogenation has therefore been used to tune the electronic and optical properties of Si layers. We discover two hydrogenated materials of layered Si8H2andSi6H2 possessing quasi-direct band gaps of 0.75 eV and 1.59 eV, respectively. Their potential applications for light emitting diode and photovoltaics are proposed and discussed. Our study opened up the possibility of hydrogenated Si layered materials as next-generation optoelectronic devices.

  16. Effects of Cold and Heat Stress on Egg Quality Traits of a Newly Developed Native Hybrid Layer

    Directory of Open Access Journals (Sweden)

    İsmail Durmuş

    2015-03-01

    Full Text Available ATAK-S is a newly developed native hybrid layer. Although the laying performance of this hybrid has been studied and determined, the performance response of the hybrid to different environmental temperature conditions is not known. This study was therefore undertaken to determine the effect of cold and heat stress on egg quality traits. Hens were divided into three different groups; control (20°C, low (12°C and high (32°C. A total of 360 hens, with 120 in each of the groups, were used in the study. Hens were held in three tier battery cages in an environmentally controlled poultry house. The study lasted for 3 weeks. No differences were found among different groups in terms of shape index, albumen height and Haugh unit of the egg quality traits. It was found that the differences among the heat groups in terms of egg shell breaking strength, egg weight, shell thickness and yolk colour were significant and the value of these traits decreased under the heat stress conditions, whereas they were not affected from the cold stress.

  17. A Novel Software Simulator Model Based on Active Hybrid Architecture

    Directory of Open Access Journals (Sweden)

    Amr AbdElHamid

    2015-01-01

    Full Text Available The simulated training is an important issue for any type of missions such as aerial, ground, sea, or even space missions. In this paper, a new flexible aerial simulator based on active hybrid architecture is introduced. The simulator infrastructure is applicable to any type of training missions and research activities. This software-based simulator is tested on aerial missions to prove its applicability within time critical systems. The proposed active hybrid architecture is introduced via using the VB.NET and MATLAB in the same simulation loop. It exploits the remarkable computational power of MATLAB as a backbone aircraft model, and such mathematical model provides realistic dynamics to the trainee. Meanwhile, the Human-Machine Interface (HMI, the mission planning, the hardware interfacing, data logging, and MATLAB interfacing are developed using VB.NET. The proposed simulator is flexible enough to perform navigation and obstacle avoidance training missions. The active hybrid architecture is used during the simulated training, and also through postmission activities (like the generation of signals playback reports for evaluation purposes. The results show the ability of the proposed architecture to fulfill the aerial simulator demands and to provide a flexible infrastructure for different simulated mission requirements. Finally, a comparison with some existing simulators is introduced.

  18. Nanodevices based on Membrane-Carbon Nanotube Hybrid Structures

    Science.gov (United States)

    Jin, Hye Jun; Kim, Tae Hyun; Namgung, Seon; Hong, Seunghun; Lee, Sang Hun; Park, Tai Hyun

    2010-03-01

    Proteins in cell membrane have been drawing attention due to their versatile functionalities such as ion transfer for neuronal activity and selective binding for sensory systems. However, it is still very difficult to manipulate and study those proteins because they easily lose their functionalities without lipid membranes. We developed a method to coat lipid membranes containing various functional membrane proteins on single-walled carbon nanotube (swCNT)-based field effect transistors (FETs). In this hybrid structure, the activity of membrane proteins can be monitored by underlying swCNT-FETs, allowing us to easily study the functionalities of membrane proteins. Furthermore, we built advanced devices based on these hybrid structures. For an example, we coated lipid membrane containing `olfactory receptors' on swCNT-FETs, resulting in `bioelectric nose' systems. The bioelectric nose system had high sensitivity and human nose-like selectivity to odorant molecules. This talk will also discuss about the future prospect of these membrane-CNT hybrid structures.

  19. Nanocomposite-Based Bulk Heterojunction Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    Bich Phuong Nguyen

    2014-01-01

    Full Text Available Photovoltaic devices based on nanocomposites composed of conjugated polymers and inorganic nanocrystals show promise for the fabrication of low-cost third-generation thin film photovoltaics. In theory, hybrid solar cells can combine the advantages of the two classes of materials to potentially provide high power conversion efficiencies of up to 10%; however, certain limitations on the current within a hybrid solar cell must be overcome. Current limitations arise from incompatibilities among the various intradevice interfaces and the uncontrolled aggregation of nanocrystals during the step in which the nanocrystals are mixed into the polymer matrix. Both effects can lead to charge transfer and transport inefficiencies. This paper highlights potential strategies for resolving these obstacles and presents an outlook on the future directions of this field.

  20. Whispered speaker identification based on feature and model hybrid compensation

    Institute of Scientific and Technical Information of China (English)

    GU Xiaojiang; ZHAO Heming; Lu Gang

    2012-01-01

    In order to increase short time whispered speaker recognition rate in variable chan- nel conditions, the hybrid compensation in model and feature domains was proposed. This method is based on joint factor analysis in training model stage. It extracts speaker factor and eliminates channel factor by estimating training speech speaker and channel spaces. Then in the test stage, the test speech channel factor is projected into feature space to engage in feature compensation, so it can remove channel information both in model and feature domains in order to improve recognition rate. The experiment result shows that the hybrid compensation can obtain the similar recognition rate in the three different training channel conditions and this method is more effective than joint factor analysis in the test of short whispered speech.

  1. A particle-based hybrid code for planet formation

    CERN Document Server

    Morishima, Ryuji

    2015-01-01

    We introduce a new particle-based hybrid code for planetary accretion. The code uses an $N$-body routine for interactions with planetary embryos while it can handle a large number of planetesimals using a super-particle approximation, in which a large number of small planetesimals are represented by a small number of tracers. Tracer-tracer interactions are handled by a statistical routine which uses the phase-averaged stirring and collision rates. We compare hybrid simulations with analytic predictions and pure $N$-body simulations for various problems in detail and find good agreements for all cases. The computational load on the portion of the statistical routine is comparable to or less than that for the $N$-body routine. The present code includes an option of hit-and-run bouncing but not fragmentation, which remains for future work.

  2. Hybrid Scenario Based Performance Analysis of DSDV and DSSR

    CERN Document Server

    Majumder, Koushik; 10.5121/ijcsit.2010.2305

    2010-01-01

    The area of mobile ad hoc networking has received considerable attention of the research community in recent years. These networks have gained immense popularity primarily due to their infrastructure-less mode of operation which makes them a suitable candidate for deployment in emergency scenarios like relief operation, battlefield etc., where either the pre-existing infrastructure is totally damaged or it is not possible to establish a new infrastructure quickly. However, MANETs are constrained due to the limited transmission range of the mobile nodes which reduces the total coverage area. Sometimes the infrastructure-less ad hoc network may be combined with a fixed network to form a hybrid network which can cover a wider area with the advantage of having less fixed infrastructure. In such a combined network, for transferring data, we need base stations which act as gateways between the wired and wireless domains. Due to the hybrid nature of these networks, routing is considered a challenging task. Several r...

  3. Hybrid Heuristic-Based Artificial Immune System for Task Scheduling

    CERN Document Server

    sanei, Masoomeh

    2011-01-01

    Task scheduling problem in heterogeneous systems is the process of allocating tasks of an application to heterogeneous processors interconnected by high-speed networks, so that minimizing the finishing time of application as much as possible. Tasks are processing units of application and have precedenceconstrained, communication and also, are presented by Directed Acyclic Graphs (DAGs). Evolutionary algorithms are well suited for solving task scheduling problem in heterogeneous environment. In this paper, we propose a hybrid heuristic-based Artificial Immune System (AIS) algorithm for solving the scheduling problem. In this regard, AIS with some heuristics and Single Neighbourhood Search (SNS) technique are hybridized. Clonning and immune-remove operators of AIS provide diversity, while heuristics and SNS provide convergence of algorithm into good solutions, that is balancing between exploration and exploitation. We have compared our method with some state-of-the art algorithms. The results of the experiments...

  4. Investigation of Bubble-Slag Layer Behaviors with Hybrid Eulerian-Lagrangian Modeling and Large Eddy Simulation

    Science.gov (United States)

    Li, Linmin; Li, Baokuan

    2016-08-01

    In ladle metallurgy, bubble-liquid interaction leads to complex phase structures. Gas bubble behavior, as well as the induced slag layer behavior, plays a significant role in the refining process and the steel quality. In the present work, a mathematical model using the large eddy simulation (LES) is developed to investigate the bubble transport and slag layer behavior in a water model of an argon-stirred ladle. The Eulerian volume of fluid model is adopted to track the liquid steel-slag-air free surfaces while the Lagrangian discrete phase model is used for tracking and handling the dynamics of discrete bubbles. The bubble coalescence is considered using O'Rourke's algorithm to solve the bubble diameter redistribution and bubbles are removed after leaving the air-liquid interface. The turbulent liquid flow that is induced by bubble-liquid interaction is solved by LES. The slag layer fluactuation, slag droplet entrainment and spout eye open-close phenomenon are well revealed. The bubble diameter distribution and the spout eye size are compared with the experiment. The results show that the hybrid Eulerian-Lagrangian-LES model provides a valid modeling framework to predict the unsteady gas bubble-slag layer coupled behaviors.

  5. Structural modifications of graphyne layers consisting of carbon atoms in the sp- and sp{sup 2}-hybridized states

    Energy Technology Data Exchange (ETDEWEB)

    Belenkov, E. A., E-mail: belenkov@csu.ru [Chelyabinsk State University (Russian Federation); Mavrinskii, V. V. [Nosov Magnitogorsk State Technical University (Russian Federation); Belenkova, T. E.; Chernov, V. M. [Chelyabinsk State University (Russian Federation)

    2015-05-15

    A model scheme is proposed for obtaining layered compounds consisting of carbon atoms in the sp- and (vnsp){sup 2}-hybridized states. This model is used to find the possibility of existing the following seven basic structural modifications of graphyne: α-, β1-, β2-, β3-, γ1-, γ2-, and γ3-graphyne. Polymorphic modifications β3 graphyne and γ3 graphyne are described. The basic structural modifications of graphyne contain diatomic polyyne chains and consist only of carbon atoms in two different crystallographically equivalent states. Other nonbasic structural modifications of graphyne can be formed via the elongation of the carbyne chains that connect three-coordinated carbon atoms and via the formation of graphyne layers with a mixed structure consisting of basic layer fragments, such as α-β-graphyne, α-γ-graphyne, and β-γ-graphyne. The semiempirical quantum-mechanical MNDO, AM1, and PM3 methods and ab initio STO6-31G basis calculations are used to find geometrically optimized structures of the basic graphyne layers, their structural parameters, and energies of their sublimation. The energy of sublimation is found to be maximal for γ2-graphyne, which should be the most stable structural modification of graphyne.

  6. Manipulating the effective index of the hybrid plasmonic waveguide based on subwavelength grating

    Science.gov (United States)

    Zhang, Rui; Bai, Bowen; Zhou, Zhiping

    2016-11-01

    In this paper, we propose and numerically study a subwavelength grating based hybrid plasmonic waveguide. The metal layer on top of the waveguide enables unique features compared with conventional silicon based waveguide. Since the field distribution in this structure is different, traditional homogeneous medium approximation is not applicative. Therefore, we develop a new effective index calculation method. This method is suitable for metal-existing waveguide as well as structures with multiple medium. Effective index of this waveguide depends on grating period, duty ratio and width, respectively. By modifying duty ratio and period of the waveguide, the relationship between effective index and waveguide width can be concave function or convex function and the slope can be similar to TM mode of silicon based waveguide, which opens up possibilities for SPPs based applications.

  7. Thermo-Elastic Triangular Sandwich Element for the Complete Stress Field Based on a Single-Layer Theory

    Science.gov (United States)

    Das, M.; Barut, A.; Madenci, E.; Ambur, D. R.

    2004-01-01

    This study presents a new triangular finite element for modeling thick sandwich panels, subjected to thermo-mechanical loading, based on a {3,2}-order single-layer plate theory. A hybrid energy functional is employed in the derivation of the element because of a C interelement continuity requirement. The single-layer theory is based on five weighted-average field variables arising from the cubic and quadratic representations of the in-plane and transverse displacement fields, respectively. The variations of temperature and distributed loading acting on the top and bottom surfaces are non-uniform. The temperature varies linearly through the thickness.

  8. Application layer multicast routing solution based on genetic algorithms

    Institute of Scientific and Technical Information of China (English)

    Peng CHENG; Qiufeng WU; Qionghai DAI

    2009-01-01

    Application layer multicast routing is a multi-objective optimization problem.Three routing con-straints,tree's cost,tree's balance and network layer load distribution are analyzed in this paper.The three fitness functions are used to evaluate a multicast tree on the three indexes respectively and one general fitness function is generated.A novel approach based on genetic algorithms is proposed.Numerical simulations show that,compared with geometrical routing rules,the proposed algorithm improve all three indexes,especially on cost and network layer load distribution indexes.

  9. A hybrid deep neural network and physically based distributed model for river stage prediction

    Science.gov (United States)

    hitokoto, Masayuki; sakuraba, Masaaki

    2016-04-01

    We developed the real-time river stage prediction model, using the hybrid deep neural network and physically based distributed model. As the basic model, 4 layer feed-forward artificial neural network (ANN) was used. As a network training method, the deep learning technique was applied. To optimize the network weight, the stochastic gradient descent method based on the back propagation method was used. As a pre-training method, the denoising autoencoder was used. Input of the ANN model is hourly change of water level and hourly rainfall, output data is water level of downstream station. In general, the desirable input of the ANN has strong correlation with the output. In conceptual hydrological model such as tank model and storage-function model, river discharge is governed by the catchment storage. Therefore, the change of the catchment storage, downstream discharge subtracted from rainfall, can be the potent input candidate of the ANN model instead of rainfall. From this point of view, the hybrid deep neural network and physically based distributed model was developed. The prediction procedure of the hybrid model is as follows; first, downstream discharge was calculated by the distributed model, and then estimates the hourly change of catchment storage form rainfall and calculated discharge as the input of the ANN model, and finally the ANN model was calculated. In the training phase, hourly change of catchment storage can be calculated by the observed rainfall and discharge data. The developed model was applied to the one catchment of the OOYODO River, one of the first-grade river in Japan. The modeled catchment is 695 square km. For the training data, 5 water level gauging station and 14 rain-gauge station in the catchment was used. The training floods, superior 24 events, were selected during the period of 2005-2014. Prediction was made up to 6 hours, and 6 models were developed for each prediction time. To set the proper learning parameters and network

  10. Graphene-based multilayers constructed from layer-by-layer self-assembly techniques.

    Science.gov (United States)

    Yu, Bing; Liu, Xiaomian; Cong, Hailin; Yuan, Hua; Wang, Dong; Li, Zejing

    2014-02-01

    This paper reviews the recent research and development of graphene-based multilayers fabricated from layer-by-layer (LBL) self-assembly technique. Graphene multilayer films, due to their excellent performances and specific applications, have attracted widespread attention during recent decades. In this paper, the preparation and property of self-assembled graphene multilayer films are introduced. The application of different graphene multilayer films in transparent conducting films (TCFs), field effect transistors (FETs), lithium ion batteries (LIBs), supercapacitors, and solar cells are summarized and discussed. The perspectives for the future developments of self-assembled graphene multilayer films are proposed.

  11. Development of polysaccharides-based edible coatings for citrus fruits: a layer-by-layer approach.

    Science.gov (United States)

    Arnon, Hadar; Granit, Rina; Porat, Ron; Poverenov, Elena

    2015-01-01

    Biodegradable coatings for citrus fruits that would replace the currently used polyethylene-based waxes, are of great interest. Methylcellulose (MC), hydroxypropyl methylcellulose (HPMC), carboxymethyl cellulose (CMC) and chitosan (CH) coatings were examined on the most sensitive citrus fruit model: mandarins. Among the examined polysaccharides, CMC provided mandarins with the best firmness, lowest weight loss and satisfying gloss, while not affecting natural flavour and the respiration process. To enhance coating performance, glycerol, oleic acid and stearic acid were added; however, mandarin quality generally deteriorated with these additives. Then, a layer-by-layer (LBL) approach was applied. LbL coatings, based on a combination of two polysaccharides, CMC as an internal layer and chitosan as an external layer, gave the best performance. Different concentrations of chitosan were examined. The LbL coatings notably improved all quantified parameters of fruit quality, proving that polysaccharide-based edible coating may offer an alternative to synthetic waxes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Hybrid photovoltaics based on semiconductor nanocrystals and amorphous silicon.

    Science.gov (United States)

    Sun, Baoquan; Findikoglu, Alp T; Sykora, Milan; Werder, Donald J; Klimov, Victor I

    2009-03-01

    Semiconductor nanocrystals (NCs) are promising materials for applications in photovoltaic (PV) structures that could benefit from size-controlled tunability of absorption spectra, the ease of realization of various tandem architectures, and, perhaps, increased conversion efficiency in the ultraviolet region through carrier multiplication. The first practical step toward utilization of the unique properties of NCs in PV technologies could be through their integration into traditional silicon-based solar cells. Here, we demonstrate an example of such hybrid PV structures that combine colloidal NCs with amorphous silicon. In these structures, NCs and silicon are electronically coupled, and the regime of this coupling can be tuned by altering the alignment of NC energy states with regard to silicon band edges. For example, using wide-gap CdSe NCs we demonstrate a photoresponse which is exclusively due to the NCs. On the other hand, in devices comprising narrow-gap PbS NCs, both the NCs and silicon contribute to photocurrent, which results in PV response extending from the visible to the near-infrared region. The hybrid silicon/PbS NC solar cells show external quantum efficiencies of approximately 7% at infrared energies and 50% in the visible and a power conversion efficiency of up to 0.9%. This work demonstrates the feasibility of hybrid PV devices that combine advantages of mature silicon fabrication technologies with the unique electronic properties of semiconductor NCs.

  13. Hybrid Thin Films Based Upon Polyoxometalates-Polymer Assembly

    Science.gov (United States)

    Qi, Na; Jing, Benxin; Zhu, Yingxi

    2014-03-01

    Block copolymers (BCPs) and polyoxometalates (POMs) have been used individually as building blocks for design and synthesis of novel functional materials. POM nanoclusters, the assemblies of transition metal oxides with well-defined atomic coordination structure, have been recently explored as novel nanomaterials... for catalysis, semiconductors, and even anti-cancer treatment due to their unique chemical, optical and electrical characteristics. We have explored the blending of inorganic POM nanocluster with BCPs into hierarchaically structured inorganic-organic hybrid nanocomposites. Using polystyrene-b-poly(ethylene oxide) (PS-b-PEO) thin films as the template, we have observed that the spatial organization of BCP thin films is modified by molybdenum based POM nanocluster to form 2D in-plane hexagonal ordered or 3D ordered network of POM-BCP assemblies, depending on the concentration ratio of POM to PS-b-PEO. The dielectric properties of such hybrid thin films can be enhanced by embedded POMs but show a strong dependence on the supramolecular structures of POM-polymer complexes. The assembly of nanoclusters in BCP-templated thin films could pave a new path to design new hybrid nanocomposites with uniquely combined functionality and material properties.

  14. Hybrid electrolytes based on ionic liquids and amorphous porous silicon nanoparticles: Organization and electrochemical properties

    KAUST Repository

    Tchalala, Mohammed

    2017-05-06

    Ionic liquids (ILs) and ionic liquid-nanoparticle (IL-NP) hybrid electrolytes have garnered a lot of interest due to their unique properties that stimulate their use in various applications. Herein, we investigate the electrochemical and photo-physical properties of organic-inorganic hybrid electrolytes based on three imidazolium-based ionic liquids, i.e., 1-buthyl-3-methylimidazolium thiocyanate ([bmim] [SCN]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim] [BF4]) and 1-buthyl-3-methylimidazolium acetate ([bmim] [Ac]) that are covalently tethered to amorphous porous silicon nanoparticles (ap-Si NPs). We found that the addition of ap-Si NPs confer to the ILs a pronounced boost in the electrocatalytic activity, and in mixtures of ap-Si NPs and [bmim] [SCN], the room-temperature current transport is enhanced by more than 5 times compared to bare [bmim] [SCN]. A detailed structural investigation by transmission electron microscope (TEM) showed that the ap-Si NPs were well dispersed, stabilized and highly aggregated in [bmim] [SCN], [emim] [BF4] and [bmim] [Ac] ILs, respectively. These observations correlate well with the enhanced current transport observed in ap-Si NPs/[bmim] [SCN] evidenced by electrochemical measurements. We interpreted these observations by the use of UV–vis absorbance, photoluminescence (PL), FTIR and solid-state NMR spectroscopy. We found that the ap-Si NPs/[bmim] [SCN] hybrid stands out due to its stability and optical transparency. This behavior is attributed to the iron(III) thiocyanate complexion as per the experimental findings. Furthermore, we found that the addition of NPs to [emim] [BF4] alters the equilibrium of the IL, which consequently improved the stability of the NPs through intermolecular interactions with the two ionic layers (anionic and cationic layers) of the IL. While in the case of [bmim] [Ac], the dispersion of ap-Si NPs was restrained because of the high viscosity of this IL.

  15. Powerful Amplification Cascades of FRET-Based Two-Layer Nonenzymatic Nucleic Acid Circuits.

    Science.gov (United States)

    Quan, Ke; Huang, Jin; Yang, Xiaohai; Yang, Yanjing; Ying, Le; Wang, He; Xie, Nuli; Ou, Min; Wang, Kemin

    2016-06-07

    Nucleic acid circuits have played important roles in biological engineering and have increasingly attracted researchers' attention. They are primarily based on nucleic acid hybridizations and strand displacement reactions between nucleic acid probes of different lengths. Signal amplification schemes that do not rely on protein enzyme show great potential in analytical applications. While the single amplification circuit often achieves linear amplification that may not meet the need for detection of target in a very small amount, it is very necessary to construct cascade circuits that allow for larger amplification of inputs. Herein, we have successfully engineered powerful amplification cascades of FRET-based two-layer nonenzymatic nucleic acid circuits, in which the outputs of catalyzed hairpin assembly (CHA) activate hybridization chain reactions (HCR) circuits to induce repeated hybridization, allowing real-time monitoring of self-assembly process by FRET signal. The cascades can yield 50000-fold signal amplification with the help of the well-designed and high-quality nucleic acid circuit amplifiers. Subsequently, with coupling of structure-switching aptamer, as low as 200 pM adenosine is detected in buffer, as well as in human serum. To our knowledge, we have for the first time realized real-time monitoring adaptation of HCR to CHA circuits and achieved amplified detection of nucleic acids and small molecules with relatively high sensitivity.

  16. Synthesis and Characterization of Layered Perovskite-type Organic-inorganic Hybrids (R-NH3)2(CH3NH3)Pb2I7

    Institute of Scientific and Technical Information of China (English)

    GUO Liling; SUN Zhang; ZHAO Guanghui; LI Xing; LIU Hanxing

    2012-01-01

    Layered organic-inorgamc hybrids containing bilayer perovsikte (R-NH3)2(CH3NH3)Pb2I7(where R=C12H25,C6H5C2H4) were synthesized by reactions in solution.The influences of the solvents and the reactant ratio on the structures of the products were investigated.The structures and the properties of the hybrids were characterized using X-ray diffraction (XRD) and ultraviolet and visible (UV) adsorption spectra.For comparing with the bilayer perovskite hybrids in structure and band gap magnitude,the hybrids containing monolayer perovskite (R-NH3)2PbI4 were also synthesized and characterized.The results demonstrate that the thickness of inorganic layer has obvious effect on the tunneling magnitude of the band gap but the organic part can be micro actuator of band gap.

  17. Thermochromic effects in a Jahn–Teller active CuCl64– layered hybrid system

    NARCIS (Netherlands)

    Caretta, A.; Miranti, R.; Arkenbout, A.H.; Polyakov, A.O.; Meetsma, A.; Hidayat, R.; Tjia, M.O.; Palstra, T.T.M.; Loosdrecht, P.H.M. van

    2013-01-01

    The hybrid material copper (II) tetrachloro-bis(phenyl ethyl ammonium) (C6H5CH2CH2NH3)2CuCl4, or PEACuCl, has been investigated by temperature-dependent spectroscopic absorption experiments. The absorption bands observed in the near-infrared region (1.3–1.9 eV) generally exhibit redshifts with incre

  18. A molecular photovoltaic system based on Dawson type polyoxometalate and porphyrin formed by layer-by-layer self assembly.

    Science.gov (United States)

    Ahmed, Iftikhar; Farha, Rana; Goldmann, Michel; Ruhlmann, Laurent

    2013-01-18

    Films based on electrostatic interactions between tetracationic porphyrin and Dawson type polyoxometalate are formed by the so called layer-by-layer method. Their photovoltaic performances are investigated by photocurrent transient measurements which showed significant photocurrent response.

  19. Polymer waveguide based hybrid opto-electric integration technology

    Science.gov (United States)

    Mao, Jinbin; Deng, Lingling; Jiang, Xiyan; Ren, Rong; Zhai, Yumeng; Wang, Jin

    2014-10-01

    While monolithic integration especially based on InP appears to be quite an expensive solution for optical devices, hybrid integration solutions using cheaper material platforms are considered powerful competitors because of the high freedom of design, yield optimization and relative cost-efficiency. Among them, the polymer planar-lightwave circuit (PLC) technology is regarded attractive as polymer offers the potential of fairly simple and low-cost fabrication, and of low-cost packaging. In our work, polymer PLC was fabricated by using the standard reactive ion etching (RIE) technique, while other active and passive devices can be integrated on the polymer PLC platform. Exemplary polymer waveguide devices was a 13-channel arrayed waveguide grating (AWG) chip, where the central channel cross-talk was below -30dB and the polarization dependent frequency shift was mitigated by inserting a half wave plate. An optical 900 hybrid was also realized with one 2×4 multi-mode interferometer (MMI). The excess insertion losses are below 4dB for the C-band, while the transmission imbalance is below 1.2dB. When such an optical hybrid was integrated vertically with mesa-type photodiodes, the responsivity of the individual PD was around 0.06 A/W, while the 3 dB bandwidth reaches 24 ~ 27 GHz, which is sufficient for 100Gbit/s receivers. Another example of the hybrid integration was to couple the polymer waveguides to fiber by applying fiber grooves, whose typical loss value was 0.2 dB per-facet over a broad spectral range from 1200-1600 nm.

  20. Pipe flow of pumping wet shotcrete based on lubrication layer.

    Science.gov (United States)

    Chen, Lianjun; Liu, Guoming; Cheng, Weimin; Pan, Gang

    2016-01-01

    Wet shotcrete can reduce dust and improve supporting strength, however, safe and efficient pipage is a key technical part of wet shotcrete process. The paper studied the pipe flow law of wet shotcrete based on lubrication layer by build the experimental pumping circuit of wet shotcrete that can carry out a number of full-scale pumping tests. The experimental results show there was a linear relationship between pressure loss and flow rate. Combined with the Buckingham rheological equation, the computing equations of the yield shear stress and plastic viscosity were deduced through linear regression. A simple analytical method allowing for a rough estimation of the pumping pressure was proposed and used when considering the lubrication layer of wet shotcrete in pipes. In addition, two kinds of particulate distributive models were established along the time axial to analyze the formation of lubrication layer which is related with particles migration. By computational fluid dynamics simulation, the lubrication layer thickness of different mix proportions was estimated. A new method for measuring the thickness of lubrication layer was proposed to verify it by binarization processing. Finally, according to the comparative analysis of experiments, simulation and computed value, it can be seen that the lubrication layer plays a key role in the process of wet shotcrete flow and with the increase of lubrication layer thickness pipe pressure declines gradually.

  1. Fatigue reliability based on residual strength model with hybrid uncertain parameters

    Institute of Scientific and Technical Information of China (English)

    Jun Wang; Zhi-Ping Qiu

    2012-01-01

    The aim of this paper is to evaluate the fatigue reliability with hybrid uncertain parameters based on a residual strength model.By solving the non-probabilistic setbased reliability problem and analyzing the reliability with randomness,the fatigue reliability with hybrid parameters can be obtained.The presented hybrid model can adequately consider all uncertainties affecting the fatigue reliability with hybrid uncertain parameters.A comparison among the presented hybrid model,non-probabilistic set-theoretic model and the conventional random model is made through two typical numerical examples.The results show that the presented hybrid model,which can ensure structural security,is effective and practical.

  2. Personalized Service System Based on Hybrid Filtering for Digital Library

    Institute of Scientific and Technical Information of China (English)

    GAO Fengrong; XING Chunxiao; DU Xiaoyong; WANG Shan

    2007-01-01

    Personalized service systems are an effective way to help users obtain recommendations for unseen items, within the enormous volume of information available based on their preferences. The most commonly used personalized service system methods are collaborative filtering, content-based filtering, and hybrid filtering. Unfortunately,each method has its drawbacks. This paper proposes a new method which unified partition-based collaborative filtering and meta-information filtering.In partition-based collaborative filtering the user-item rating matrix can be partitioned into low-dimensional dense materces using a matrixclustering algorithm. Recommendations are generated based on these low-dimensional matrices.Additionally,the very low ratings problem can be solved using meta-information filtering. The unified method is applied to a digital resource management system. The experimental results show the high efficiency and good performance of the new approach.

  3. Low temperature hydrogen sensing using reduced graphene oxide and tin oxide nanoflowers based hybrid structure

    Science.gov (United States)

    Venkatesan, A.; Rathi, Servin; Lee, In-Yeal; Park, Jinwoo; Lim, Dongsuk; Kim, Gil-Ho; Kannan, E. S.

    2016-12-01

    In this paper, we have demonstrated a low temperature hydrogen (H2) sensor based on reduced graphene oxide (rGO) and tin oxide nanoflowers (SnO2 NFs) hybrid composite film. The addition of SnO2 NFs into rGO solution inhibits irreversible restacking and agglomeration of rGO and increases the active surface area for interaction with H2. This rGO-SnO2 NFs hybrid film sensor showed an excellent response to H2 at 60 °C at 200 ppm with an improvement of 126% compared to pure rGO which was used as a control sample. The sensor also showed good response and recovery time in comparison to pure rGO film. The highly improved H2 sensing characteristics of rGO-SnO2 NFs hybrid are due to its (a) unique structural geometry that increased the surface area for H2 adsorption, and (b) change in the width of depletion layer at the interface due to H2 interaction.

  4. DNA Hybridization Sensors Based on Electrochemical Impedance Spectroscopy as a Detection Tool

    Directory of Open Access Journals (Sweden)

    Jin-Young Park

    2009-11-01

    Full Text Available Recent advances in label free DNA hybridization sensors employing electrochemical impedance spectroscopy (EIS as a detection tool are reviewed. These sensors are based on the modulation of the blocking ability of an electrode modified with a probe DNA by an analyte, i.e., target DNA. The probe DNA is immobilized on a self-assembled monolayer, a conducting polymer film, or a layer of nanostructures on the electrode such that desired probe DNA would selectively hybridize with target DNA. The rate of charge transfer from the electrode thus modified to a redox indicator, e.g., [Fe(CN6]3–/4–, which is measured by EIS in the form of charge transfer resistance (Rct, is modulated by whether or not, as well as how much, the intended target DNA is selectively hybridized. Efforts made to enhance the selectivity as well as the sensitivity of DNA sensors and to reduce the EIS measurement time are briefly described along with brief future perspectives in developing DNA sensors.

  5. DNA Hybridization Sensors Based on Electrochemical Impedance Spectroscopy as a Detection Tool

    Science.gov (United States)

    Park, Jin-Young; Park, Su-Moon

    2009-01-01

    Recent advances in label free DNA hybridization sensors employing electrochemical impedance spectroscopy (EIS) as a detection tool are reviewed. These sensors are based on the modulation of the blocking ability of an electrode modified with a probe DNA by an analyte, i.e., target DNA. The probe DNA is immobilized on a self-assembled monolayer, a conducting polymer film, or a layer of nanostructures on the electrode such that desired probe DNA would selectively hybridize with target DNA. The rate of charge transfer from the electrode thus modified to a redox indicator, e.g., [Fe(CN)6]3−/4−, which is measured by EIS in the form of charge transfer resistance (Rct), is modulated by whether or not, as well as how much, the intended target DNA is selectively hybridized. Efforts made to enhance the selectivity as well as the sensitivity of DNA sensors and to reduce the EIS measurement time are briefly described along with brief future perspectives in developing DNA sensors. PMID:22303136

  6. Development of hybrid artificial intelligent based handover decision algorithm

    Directory of Open Access Journals (Sweden)

    A.M. Aibinu

    2017-04-01

    Full Text Available The possibility of seamless handover remains a mirage despite the plethora of existing handover algorithms. The underlying factor responsible for this has been traced to the Handover decision module in the Handover process. Hence, in this paper, the development of novel hybrid artificial intelligent handover decision algorithm has been developed. The developed model is made up of hybrid of Artificial Neural Network (ANN based prediction model and Fuzzy Logic. On accessing the network, the Received Signal Strength (RSS was acquired over a period of time to form a time series data. The data was then fed to the newly proposed k-step ahead ANN-based RSS prediction system for estimation of prediction model coefficients. The synaptic weights and adaptive coefficients of the trained ANN was then used to compute the k-step ahead ANN based RSS prediction model coefficients. The predicted RSS value was later codified as Fuzzy sets and in conjunction with other measured network parameters were fed into the Fuzzy logic controller in order to finalize handover decision process. The performance of the newly developed k-step ahead ANN based RSS prediction algorithm was evaluated using simulated and real data acquired from available mobile communication networks. Results obtained in both cases shows that the proposed algorithm is capable of predicting ahead the RSS value to about ±0.0002 dB. Also, the cascaded effect of the complete handover decision module was also evaluated. Results obtained show that the newly proposed hybrid approach was able to reduce ping-pong effect associated with other handover techniques.

  7. Photocatalytic enhancement of floating photocatalyst: Layer-by-layer hybrid carbonized chitosan and Fe-N- codoped TiO2 on fly ash cenospheres

    Science.gov (United States)

    Song, Jingke; Wang, Xuejiang; Bu, Yunjie; Wang, Xin; Zhang, Jing; Huang, Jiayu; Ma, RongRong; Zhao, Jianfu

    2017-01-01

    Due to the advantage of floating on water surface, floating photocatalysts show higher rates of radical formation and collection efficiencies. And they were expected to be used for solar remediation of non-stirred and non-oxygenated reservoirs. In this research, floating fly ash cenospheres (FAC) supported layer-by- layer hybrid carbonized chitosan and Fe-N-codoped TiO2 was prepared by a simple sol-gel method. The catalysts were characterized by X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy(DRS), nitrogen adsorption analyses for Brunauer-Emmett-Teller (BET) specific surface area. It is indicated that Fe-N codoped narrowed the material's band gap, and the layer of carbonized chitosan (Cts) increased the catalyst's adsorption capacity and the absorption ability of visible light. Comparing with Fe-N-TiO2/FAC and N-TiO2/FAC, the composite photocatalyst show excellent performance on the degradation of RhB. Photodegradation rate of RhB by Fe-N-TiO2/FAC-Cts was 0.01018 min-1, which is about 1.5 and 2.09 times higher than Fe-N-TiO2/FAC and N-TiO2/FAC under visible light irradiation in 240 min, respectively. The dye photosentization, capture of holes and electrons by Fe3+ ion, and synergistic effect of adsorption and photodegradation were attributed to the results for the improvement of photocatalytic performance. The floating photocatalyst can be reused for at least three consecutive times without any significant decrease on the degradation of Rhodamin B after each reuse.

  8. The Layer Boundary Effect on Multi-Layer Mesoporous TiO2 Film Based Dye Sensitized Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Feng; Zhu, Kai; Zhao, Yixin

    2016-10-01

    Multi-layer mesoporous TiO2 prepared by screen printing is widely used for fabrication of high-efficiency dye-sensitized solar cells (DSSCs). We compare the three types of ~10 um thick mesoporous TiO2 films, which were screen printed as 1-, 2- and 4-layers using the same TiO2 nanocrystal paste. The layer boundary of the multi-layer mesoporous TiO2 films was observed in the cross-section SEM. The existence of a layer boundary could reduce the photoelectron diffusion length with the increase of layer number. However, the photoelectron diffusion lengths of the Z907 dye sensitized solar cells based on these different layered mesoporous TiO2 films are all longer than the film thickness. Consequently, the photovoltaic performance seems to have little dependence on the layer number of the multi-layer TiO2 based DSSCs.

  9. GaInN-based tunnel junctions with graded layers

    Science.gov (United States)

    Takasuka, Daiki; Akatsuka, Yasuto; Ino, Masataka; Koide, Norikatsu; Takeuchi, Tetsuya; Iwaya, Motoaki; Kamiyama, Satoshi; Akasaki, Isamu

    2016-08-01

    We demonstrated low-resistivity GaInN-based tunnel junctions using graded GaInN layers. A systematic investigation of the samples grown by metalorganic vapor phase epitaxy revealed that a tunnel junction consisting of a 4 nm both-sides graded GaInN layer (Mg: 1 × 1020 cm-3) and a 2 nm GaN layer (Si: 7 × 1020 cm-3) showed the lowest specific series resistance of 2.3 × 10-4 Ω cm2 at 3 kA/cm2 in our experiment. The InN mole fraction in the 4 nm both-sides graded GaInN layer was changed from 0 through 0.4 to 0. The obtained resistance is comparable to those of standard p-contacts with Ni/Au and MBE-grown tunnel junctions.

  10. A layer reduction based community detection algorithm on multiplex networks

    Science.gov (United States)

    Wang, Xiaodong; Liu, Jing

    2017-04-01

    Detecting hidden communities is important for the analysis of complex networks. However, many algorithms have been designed for single layer networks (SLNs) while just a few approaches have been designed for multiplex networks (MNs). In this paper, we propose an algorithm based on layer reduction for detecting communities on MNs, which is termed as LRCD-MNs. First, we improve a layer reduction algorithm termed as neighaggre to combine similar layers and keep others separated. Then, we use neighaggre to find the community structure hidden in MNs. Experiments on real-life networks show that neighaggre can obtain higher relative entropy than the other algorithm. Moreover, we apply LRCD-MNs on some real-life and synthetic multiplex networks and the results demonstrate that, although LRCD-MNs does not have the advantage in terms of modularity, it can obtain higher values of surprise, which is used to evaluate the quality of partitions of a network.

  11. Robot Positioning and Navigation Based on Hybrid Wireless Sensor Network

    Institute of Scientific and Technical Information of China (English)

    Shun-cai YAO; Jin-dong TAN; Hong-xia PAN

    2010-01-01

    Traditional sensor network and robot navigation are based an the map of detecting the fields available in advance.The optimal algorithms are developed to solve the energy saving,the shortest path problems,etc.However,in the practical encironment,there are many fields,whose map is difficult to get,and needs to be detected.In this paper a kind of ad-hoc navigation algorithm is explored,which is based on the hybrid sensor network without the prior map in advance.The navigation system is composed of static nodes and dynamic nodes.The static nodes monitor the occurrances of the events and broadcast them.In the system,a kind of algorithm is to locate the robot,which is based on cluster broadcasting.The dynamic nodes detect the adversary or dangerous fields and broadcast warning messages.The robot gets the message and follows ad-hoc routine to arrive where the events occur.In the whole process,energy saving has been taken into account.The algorithms,which are based on the hybrid sensor network,are given in this paper.The simulation and practical results are also available.

  12. XPS-nanocharacterization of organic layers electrochemically grafted on the surface of SnO2 thin films to produce a new hybrid material coating

    Science.gov (United States)

    Drevet, R.; Dragoé, D.; Barthés-Labrousse, M. G.; Chaussé, A.; Andrieux, M.

    2016-10-01

    This work presents the synthesis and the characterization of hybrid material thin films obtained by the combination of two processes. The electrochemical grafting of organic layers made of carboxyphenyl moieties is carried out from the reduction of a diazonium salt on tin dioxide (SnO2) thin films previously deposited on Si substrates by metal organic chemical vapor deposition (MOCVD). Since the MOCVD experimental parameters impact the crystal growth of the SnO2 layer (i.e. its morphology and its texturation), various electrochemical grafting models can occur, producing different hybrid materials. In order to evidence the efficiency of the electrochemical grafting of the carboxyphenyl moieties, X-ray Photoelectron Spectroscopy (XPS) is used to characterize the first nanometers in depth of the synthesized hybrid material layer. Then three electrochemical grafting models are proposed.

  13. Identification of waves in the lower-hybrid frequency range in the scrape-off layer plasma of Alcator C-Mod

    Science.gov (United States)

    Shinya, Takahiro; Gyou Baek, Seung; Wallace, Gregory M.; Shiraiwa, Syun'ichi; Takase, Yuichi; Parker, Ronald R.; Bonoli, Paul T.; Brunner, Dan; Faust, Ian; LaBombard, Brian L.; Wukitch, Steve

    2017-03-01

    Polarization resolved measurements of the parallel refractive index {{N}\\parallel}\\equiv c{{k}\\parallel}/ω of the driven RF waves in the lower hybrid (LH) range of frequencies are performed using arrays of RF magnetic probes in the scrape-off layer plasma of Alcator C-Mod. The measured {{N}\\parallel} of the RF magnetic field component parallel to the background magnetic field is about  -1.6, which corresponds to the peak of the launched LH {{N}\\parallel} spectrum. Based on the wave dispersion relationship, this wave is identified as the LH slow wave. On the other hand, the RF magnetic field component perpendicular to the magnetic field is found to have a lower {{N}\\parallel} of  -1.2, and is detected only near the last closed flux surface. This wave is identified as the LH fast wave generated by slow-fast wave mode conversion.

  14. A Hybrid Metaheuristic-Based Approach for the Aerodynamic Optimization of Small Hybrid Wind Turbine Rotors

    Directory of Open Access Journals (Sweden)

    José F. Herbert-Acero

    2014-01-01

    Full Text Available This work presents a novel framework for the aerodynamic design and optimization of blades for small horizontal axis wind turbines (WT. The framework is based on a state-of-the-art blade element momentum model, which is complemented with the XFOIL 6.96 software in order to provide an estimate of the sectional blade aerodynamics. The framework considers an innovative nested-hybrid solution procedure based on two metaheuristics, the virtual gene genetic algorithm and the simulated annealing algorithm, to provide a near-optimal solution to the problem. The objective of the study is to maximize the aerodynamic efficiency of small WT (SWT rotors for a wide range of operational conditions. The design variables are (1 the airfoil shape at the different blade span positions and the radial variation of the geometrical variables of (2 chord length, (3 twist angle, and (4 thickness along the blade span. A wind tunnel validation study of optimized rotors based on the NACA 4-digit airfoil series is presented. Based on the experimental data, improvements in terms of the aerodynamic efficiency, the cut-in wind speed, and the amount of material used during the manufacturing process were achieved. Recommendations for the aerodynamic design of SWT rotors are provided based on field experience.

  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. A novel hybrid plasmonic waveguide with loss compensation via electrically pumped gain medium based on silicon platform

    Science.gov (United States)

    Zhu, Ning

    2013-01-01

    In this paper we propose and study a new hybrid plasmonic waveguide structure with gain medium. The structure is based on silicon platform with gain medium to be III-V material, which can be electrically pumped. The whole structure can be realized through the bonding technique. An adhesive polymer layer adopted in the bonding process acts as the low refractive index layer here in the hybrid plasmonic waveguide. Further simulation with gain presented shows that a moderate gain coefficient of 891 cm-1 is required for lossless propagation while keeping subwavelength modal size, especially in the lateral direction which is important for high density integration. Considering the fabrication compatibility, this new SPP structure would be highly favorable in the silicon photonics.

  17. DNA Immobilization and Hybridization Detection by the Intrinsic Molecular Charge Using Capacitive Field-Effect Sensors Modified with a Charged Weak Polyelectrolyte Layer.

    Science.gov (United States)

    Bronder, Thomas S; Poghossian, Arshak; Scheja, Sabrina; Wu, Chunsheng; Keusgen, Michael; Mewes, Dieter; Schöning, Michael J

    2015-09-16

    Miniaturized setup, compatibility with advanced micro- and nanotechnologies, and ability to detect biomolecules by their intrinsic molecular charge favor the semiconductor field-effect platform as one of the most attractive approaches for the development of label-free DNA chips. In this work, a capacitive field-effect EIS (electrolyte-insulator-semiconductor) sensor covered with a layer-by-layer prepared, positively charged weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)) was used for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization. The negatively charged probe single-stranded DNA (ssDNA) molecules were electrostatically adsorbed onto the positively charged PAH layer, resulting in a preferentially flat orientation of the ssDNA molecules within the Debye length, thus yielding a reduced charge-screening effect and a higher sensor signal. Each sensor-surface modification step (PAH adsorption, probe ssDNA immobilization, hybridization with complementary target DNA (cDNA), reducing an unspecific adsorption by a blocking agent, incubation with noncomplementary DNA (ncDNA) solution) was monitored by means of capacitance-voltage and constant-capacitance measurements. In addition, the surface morphology of the PAH layer was studied by atomic force microscopy and contact-angle measurements. High hybridization signals of 34 and 43 mV were recorded in low-ionic strength solutions of 10 and 1 mM, respectively. In contrast, a small signal of 4 mV was recorded in the case of unspecific adsorption of fully mismatched ncDNA. The density of probe ssDNA and dsDNA molecules as well as the hybridization efficiency was estimated using the experimentally measured DNA immobilization and hybridization signals and a simplified double-layer capacitor model. The results of field-effect experiments were supported by fluorescence measurements, verifying the DNA-immobilization and hybridization event.

  18. A Matlab—Based Simulation for Hybrid Electric Motorcycle

    Institute of Scientific and Technical Information of China (English)

    邵定国; 李永斌; 汪信尧; 江建中

    2003-01-01

    This paper presents a simulation and modeling package based on Matlab for a parallel hybrid electric motorcycle (HEM).The package consists of several main detailed models: internal combustion engine (ICE), motor, continuously variable transmission(CVT), battery, energy management system (EMS) etc. Each component is built as a library, and can be connected together accord-ing to the parallel HEM's topology. Simulation results, such as ICE power demand, motor power demand, battery instantaneous state-of-charge (SOC), pollution emissions etc. Are given and discussed. Lastly experimental data verify our simulation results.

  19. ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    X.C. Li; W.X. Zhu; G. Chen; D.S. Mei; J. Zhang; K.M. Chen

    2003-01-01

    An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples,the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

  20. An online hybrid BCI system based on SSVEP and EMG

    Science.gov (United States)

    Lin, Ke; Cinetto, Andrea; Wang, Yijun; Chen, Xiaogang; Gao, Shangkai; Gao, Xiaorong

    2016-04-01

    Objective. A hybrid brain-computer interface (BCI) is a device combined with at least one other communication system that takes advantage of both parts to build a link between humans and machines. To increase the number of targets and the information transfer rate (ITR), electromyogram (EMG) and steady-state visual evoked potential (SSVEP) were combined to implement a hybrid BCI. A multi-choice selection method based on EMG was developed to enhance the system performance. Approach. A 60-target hybrid BCI speller was built in this study. A single trial was divided into two stages: a stimulation stage and an output selection stage. In the stimulation stage, SSVEP and EMG were used together. Every stimulus flickered at its given frequency to elicit SSVEP. All of the stimuli were divided equally into four sections with the same frequency set. The frequency of each stimulus in a section was different. SSVEPs were used to discriminate targets in the same section. Different sections were classified using EMG signals from the forearm. Subjects were asked to make different number of fists according to the target section. Canonical Correlation Analysis (CCA) and mean filtering was used to classify SSVEP and EMG separately. In the output selection stage, the top two optimal choices were given. The first choice with the highest probability of an accurate classification was the default output of the system. Subjects were required to make a fist to select the second choice only if the second choice was correct. Main results. The online results obtained from ten subjects showed that the mean accurate classification rate and ITR were 81.0% and 83.6 bits min-1 respectively only using the first choice selection. The ITR of the hybrid system was significantly higher than the ITR of any of the two single modalities (EMG: 30.7 bits min-1, SSVEP: 60.2 bits min-1). After the addition of the second choice selection and the correction task, the accurate classification rate and ITR was

  1. Carbon-Based Materials for Lithium-Ion Batteries, Electrochemical Capacitors, and Their Hybrid Devices.

    Science.gov (United States)

    Yao, Fei; Pham, Duy Tho; Lee, Young Hee

    2015-07-20

    A rapidly developing market for portable electronic devices and hybrid electrical vehicles requires an urgent supply of mature energy-storage systems. As a result, lithium-ion batteries and electrochemical capacitors have lately attracted broad attention. Nevertheless, it is well known that both devices have their own drawbacks. With the fast development of nanoscience and nanotechnology, various structures and materials have been proposed to overcome the deficiencies of both devices to improve their electrochemical performance further. In this Review, electrochemical storage mechanisms based on carbon materials for both lithium-ion batteries and electrochemical capacitors are introduced. Non-faradic processes (electric double-layer capacitance) and faradic reactions (pseudocapacitance and intercalation) are generally explained. Electrochemical performance based on different types of electrolytes is briefly reviewed. Furthermore, impedance behavior based on Nyquist plots is discussed. We demonstrate the influence of cell conductivity, electrode/electrolyte interface, and ion diffusion on impedance performance. We illustrate that relaxation time, which is closely related to ion diffusion, can be extracted from Nyquist plots and compared between lithium-ion batteries and electrochemical capacitors. Finally, recent progress in the design of anodes for lithium-ion batteries, electrochemical capacitors, and their hybrid devices based on carbonaceous materials are reviewed. Challenges and future perspectives are further discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Unit-Specific Event-Based and Slot-Based Hybrid Model Framework with Hierarchical Structure for Short-Term Scheduling

    Directory of Open Access Journals (Sweden)

    Yue Wang

    2015-01-01

    Full Text Available Unit-specific event-based continuous-time model has inaccurate calculation problems in involving resource constraints, due to the heterogeneous locations of the event points for different units. In order to address this limitation, a continuous-time unit-specific event-based and slot-based hybrid model framework with hierarchical structure is proposed in this work. A unit-specific event-based model without utility constraints is formulated in upper layer, and a slot-based model is introduced in lower layer. In the hierarchical structure, the two layers jointly address the short-term production scheduling problem of batch plants under utility consideration. The key features of this work include the following: (a eliminating overstrict constraints on utility resources, (b solving multiple counting problems, and (c considering duration time of event points in calculating utility utilization level. The effectiveness and advantages of proposed model are illustrated through two benchmark examples from the literatures.

  3. Design of time interval generator based on hybrid counting method

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yuan [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wang, Zhaoqi [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Lu, Houbing [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Hefei Electronic Engineering Institute, Hefei 230037 (China); Chen, Lian [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Jin, Ge, E-mail: goldjin@ustc.edu.cn [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2016-10-01

    Time Interval Generators (TIGs) are frequently used for the characterizations or timing operations of instruments in particle physics experiments. Though some “off-the-shelf” TIGs can be employed, the necessity of a custom test system or control system makes the TIGs, being implemented in a programmable device desirable. Nowadays, the feasibility of using Field Programmable Gate Arrays (FPGAs) to implement particle physics instrumentation has been validated in the design of Time-to-Digital Converters (TDCs) for precise time measurement. The FPGA-TDC technique is based on the architectures of Tapped Delay Line (TDL), whose delay cells are down to few tens of picosecond. In this case, FPGA-based TIGs with high delay step are preferable allowing the implementation of customized particle physics instrumentations and other utilities on the same FPGA device. A hybrid counting method for designing TIGs with both high resolution and wide range is presented in this paper. The combination of two different counting methods realizing an integratable TIG is described in detail. A specially designed multiplexer for tap selection is emphatically introduced. The special structure of the multiplexer is devised for minimizing the different additional delays caused by the unpredictable routings from different taps to the output. A Kintex-7 FPGA is used for the hybrid counting-based implementation of a TIG, providing a resolution up to 11 ps and an interval range up to 8 s.

  4. A Probability-Based Hybrid User Model for Recommendation System

    Directory of Open Access Journals (Sweden)

    Jia Hao

    2016-01-01

    Full Text Available With the rapid development of information communication technology, the available information or knowledge is exponentially increased, and this causes the well-known information overload phenomenon. This problem is more serious in product design corporations because over half of the valuable design time is consumed in knowledge acquisition, which highly extends the design cycle and weakens the competitiveness. Therefore, the recommender systems become very important in the domain of product domain. This research presents a probability-based hybrid user model, which is a combination of collaborative filtering and content-based filtering. This hybrid model utilizes user ratings and item topics or classes, which are available in the domain of product design, to predict the knowledge requirement. The comprehensive analysis of the experimental results shows that the proposed method gains better performance in most of the parameter settings. This work contributes a probability-based method to the community for implement recommender system when only user ratings and item topics are available.

  5. Piezoelectric-based hybrid reserve power sources for munitions

    Science.gov (United States)

    Rastegar, J.; Kwok, P.

    2017-04-01

    Reserve power sources are used extensively in munitions and other devices, such as emergency devices or remote sensors that need to be powered only once and for a relatively short duration. Current chemical reserve power sources, including thermal batteries and liquid reserve batteries sometimes require more than 100 msec to become fully activated. In many applications, however, electrical energy is required in a few msec following the launch event. In such applications, other power sources are needed to provide power until the reserve battery is fully activated. The amount of electrical energy that is required by most munitions before chemical reserve batteries are fully activated is generally small and can be provided by properly designed piezoelectric-based energy harvesting devices. In this paper, the development of a hybrid reserve power source that is constructed by integration of a piezoelectric-based energy harvesting device with a reserve battery to provide power almost instantaneously upon munitions firing or other similar events is being reported. A review of the state of the art in piezoelectric-based electrical energy harvesting methods and devices and their charge collection electronics for use in the developed hybrid power sources is provided together with the results of testing of the piezoelectric component of the power source and its electronic safety and charge collection electronics.

  6. Alginate-based hybrid aerogel microparticles for mucosal drug delivery.

    Science.gov (United States)

    Gonçalves, V S S; Gurikov, P; Poejo, J; Matias, A A; Heinrich, S; Duarte, C M M; Smirnova, I

    2016-10-01

    The application of biopolymer aerogels as drug delivery systems (DDS) has gained increased interest during the last decade since these structures have large surface area and accessible pores allowing for high drug loadings. Being biocompatible, biodegradable and presenting low toxicity, polysaccharide-based aerogels are an attractive carrier to be applied in pharmaceutical industry. Moreover, some polysaccharides (e.g. alginate and chitosan) present mucoadhesive properties, an important feature for mucosal drug delivery. This feature allows to extend the contact of DDS with biological membranes, thereby increasing the absorption of drugs through the mucosa. Alginate-based hybrid aerogels in the form of microparticles (alginate and further dried with supercritical CO2 (sc-CO2). Spherical mesoporous aerogel microparticles were obtained for alginate, hybrid alginate/pectin and alginate/κ-carrageenan aerogels, presenting high specific surface area (370-548m(2)g(-1)) and mucoadhesive properties. The microparticles were loaded with ketoprofen via adsorption from its solution in sc-CO2, and with quercetin via supercritical anti-solvent precipitation. Loading of ketoprofen was in the range between 17 and 22wt% whereas quercetin demonstrated loadings of 3.1-5.4wt%. Both the drugs were present in amorphous state. Loading procedure allowed the preservation of antioxidant activity of quercetin. Release of both drugs from alginate/κ-carrageenan aerogel was slightly faster compared to alginate/pectin. The results indicate that alginate-based aerogel microparticles can be viewed as promising matrices for mucosal drug delivery applications.

  7. Piezoelectric-based hybrid reserve power sources for munitions

    Science.gov (United States)

    Rastegar, Jahangir; Pereira, Carlos M.; Feng, Dake

    2016-05-01

    Reserve power sources are used extensively in munitions and other devices such as emergency devices or remote sensors that have to be powered only once and for a relatively short duration. Current chemical reserve power sources, including thermal batteries and liquid reserve batteries require sometimes in excess of 100 msec to become fully activated. In many applications, however, electrical energy is required in a few msec following the launch event. In such applications, other power sources have to be provided to provide power until the reserve battery is fully activated. The amount of electrical energy that is required by most munitions before chemical reserve batteries are fully activated is generally small and can be provided by properly designed piezoelectric-based energy harvesting devices. In this paper the development of a hybrid reserve power source obtained by the integration of a piezoelectric-based energy harvesting device with a reserve battery that can provide power almost instantaneously upon munitions firing or other similar events is being reported. A review of the state of the art in piezoelectric-based electrical energy harvesting methods and devices and their charge collection electronics for use in the developed hybrid power sources is also provided together with the results of testing of the piezoelectric component of the power source and its electronic safety and charge collection electronics.

  8. Design of time interval generator based on hybrid counting method

    Science.gov (United States)

    Yao, Yuan; Wang, Zhaoqi; Lu, Houbing; Chen, Lian; Jin, Ge

    2016-10-01

    Time Interval Generators (TIGs) are frequently used for the characterizations or timing operations of instruments in particle physics experiments. Though some "off-the-shelf" TIGs can be employed, the necessity of a custom test system or control system makes the TIGs, being implemented in a programmable device desirable. Nowadays, the feasibility of using Field Programmable Gate Arrays (FPGAs) to implement particle physics instrumentation has been validated in the design of Time-to-Digital Converters (TDCs) for precise time measurement. The FPGA-TDC technique is based on the architectures of Tapped Delay Line (TDL), whose delay cells are down to few tens of picosecond. In this case, FPGA-based TIGs with high delay step are preferable allowing the implementation of customized particle physics instrumentations and other utilities on the same FPGA device. A hybrid counting method for designing TIGs with both high resolution and wide range is presented in this paper. The combination of two different counting methods realizing an integratable TIG is described in detail. A specially designed multiplexer for tap selection is emphatically introduced. The special structure of the multiplexer is devised for minimizing the different additional delays caused by the unpredictable routings from different taps to the output. A Kintex-7 FPGA is used for the hybrid counting-based implementation of a TIG, providing a resolution up to 11 ps and an interval range up to 8 s.

  9. Solution-Processed Hybrid Light-Emitting Devices Comprising TiO2 Nanorods and WO3 Layers as Carrier-Transporting Layers

    Science.gov (United States)

    Tsai, Tsung-Yan; Yan, Po-Ruei; Yang, Sheng-Hsiung

    2016-11-01

    The goal of this research is to prepare inverted light-emitting devices with improved performance by combining titanium dioxide (TiO2) nanorods and tungsten trioxide (WO3) layer. TiO2 nanorods with different lengths were established directly on the fluorine-doped tin oxide (FTO) substrates by the hydrothermal method. The prepared TiO2 nanorods with lengths shorter than 200 nm possess transmittance higher than 80% in the visible range. Inverted light-emitting devices with the configuration of FTO/TiO2 nanorods/ionic PF/MEH-PPV/PEDOT:PSS/WO3/Au were constructed. The best device based on 100-nm-height TiO2 nanorods achieved a max brightness of 4493 cd/m2 and current efficiency of 0.66 cd/A, revealing much higher performance compared with those using TiO2 compact layer or nanorods with longer lengths as electron-transporting layers.

  10. Diamond-based protective layer for optical biosensors

    Science.gov (United States)

    Majchrowicz, D.; Ficek, M.; Baran, T.; WÄ sowicz, M.; Struk, P.; Jedrzejewska-Szczerska, M.

    2016-09-01

    Optical biosensors have become a powerful alternative to the conventional ways of measurement owing to their great properties, such as high sensitivity, high dynamic range, cost effectiveness and small size. Choice of an optical biosensor's materials is an important factor and impacts the quality of the obtained spectra. Examined biological objects are placed on a cover layer which may react with samples in a chemical, biological and mechanical way, therefore having a negative impact on the measurement reliability. Diamond, a metastable allotrope of carbon with sp3 hybridization, shows outstanding properties such as: great chemical stability, bio-compatibility, high thermal conductivity, wide bandgap and optical transparency. Additionally it possesses great mechanical durability, which makes it a long-lasting material. The protective diamond thin films were deposited on the substrate using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) system. The surface morphology and roughness was assessed with atomic force microscopy and profilometry. We have performed a series of measurements to assess the biocompatibility of diamond thin films with whole blood. The results show that thin diamond protective layer does not affect the red blood cells, while retaining the sensors high resolution and dynamic range of measurement. Therefore, we conclude that diamond thin films are a viable protective coating for optical biosensors, which allows to examine many biological elements. We project that it can be particularly useful not only for biological objects but also under extreme conditions like radioactive or chemically aggressive environments and high temperatures.

  11. Improved performance of diatomite-based dental nanocomposite ceramics using layer-by-layer assembly

    Directory of Open Access Journals (Sweden)

    Lu X

    2012-04-01

    Full Text Available Xiaoli Lu1,2, Yang Xia1, Mei Liu1, Yunzhu Qian3, Xuefeng Zhou4, Ning Gu4, Feimin Zhang1,41Institute of Stomatology, Nanjing Medical University, Nanjing, 2Nantong Stomatological Hospital, Nantong, 3Center of Stomatology, The Second Affiliated Hospital of Suzhou University, Suzhou, 4Suzhou Institute, Southeast University, Suzhou, People's Republic of ChinaAbstract: To fabricate high-strength diatomite-based ceramics for dental applications, the layer-by-layer technique was used to coat diatomite particles with cationic [poly(allylamine hydrochloride] and anionic [poly(sodium 4-styrenesulfonate] polymers to improve the dispersion and adsorption of positively charged nano-ZrO2 (zirconia as a reinforcing agent. The modified diatomite particles had reduced particle size, narrower size distribution, and were well dispersed, with good adsorption of nano-ZrO2. To determine the optimum addition levels for nano-ZrO2, ceramics containing 0, 20, 25, 30, and 35 wt% nano-ZrO2 were sintered and characterized by the three-point bending test and microhardness test. In addition to scanning electron microscopy, propagation phase-contrast synchrotron X-ray microtomography was used to examine the internal structure of the ceramics. The addition of 30 wt% nano-ZrO2 resulted in the highest flexural strength and fracture toughness with reduced porosity. Shear bond strength between the core and veneer of our diatomite ceramics and the most widely used dental ceramics were compared; the shear bond strength value for the diatomite-based ceramics was found to be significantly higher than for other groups (P < 0.05. Our results show that diatomite-based nanocomposite ceramics are good potential candidates for ceramic-based dental materials.Keywords: layer-by-layer, diatomite, nanoceramics, zirconia (ZrO2, dental materials

  12. Cross Layer Analysis of P2MP Hybrid FSO/RF Network

    KAUST Repository

    Rakia, Tamer

    2017-02-22

    This paper presents and analyzes a point-tomultipoint (P2MP) network that uses a number of freespace optical (FSO) links for data transmission from the central node to the different remote nodes of the network. A common backup radio frequency (RF) link can be used by the central node for data transmission to any remote node in case any one of the FSO links fails. Each remote node is assigned a transmit buffer at the central node. Considering the transmission link from the central node to a tagged remote node, we study various performance metrics. Specifically,we study the throughput from the central node to the tagged node, the average transmit buffer size, the symbol queuing delay in the transmit buffer, the efficiency of the queuing system, the symbol loss probability, and the RF link utilization. Numerical examples are presented to compare the performance of the proposed P2MP hybrid FSO/RF network with that of a P2MP FSO-only network and show that the P2MP hybrid FSO/RF network achieves considerable performance improvement over the P2MP FSO-only network.

  13. Improved Offline Connected Script Recognition Based on Hybrid Strategy

    Directory of Open Access Journals (Sweden)

    Tanzila Saba

    2010-06-01

    Full Text Available In domain of analytic cursive word recognition, there are two main approaches: explicit segmentation based and implicit segmentation based. However, both approaches have their own shortcomings. To overcome individual weaknesses, this paper presents a hybrid strategy for recognition of strings of characters (words or numerals. In a two stage dynamic programming based, lexicon driven approach, first an explicit segmentation is applied to segment either cursive andwritten words or numeric strings. However, at this stage, segmentation points are not finalized. In the second verification stage, statistical features are extracted from each segmented area to recognize characters using a trained neural network. To enhance segmentation and recognition accuracy, lexicon is consulted using existing dynamic programming matching techniques. Accordingly, segmentation points are altered to decide true character boundaries byusing lexicon feedback. A rigorous experimental protocol shows high performance of the proposed method for cursive handwritten words and numeral strings.

  14. Biofunctionalization of carbon nanotubes/chitosan hybrids on Ti implants by atom layer deposited ZnO nanostructures

    Science.gov (United States)

    Zhu, Yizhou; Liu, Xiangmei; Yeung, Kelvin W. K.; Chu, Paul K.; Wu, Shuilin

    2017-04-01

    One-dimensional (1D) nanostructures of ZnO using atomic layer deposition (ALD) on chitosan (CS) modified carbon nanotubes (CNTs) were first introduced onto the surfaces of biomedical implants. When the content of ZnO is not sufficient, CNTs can strengthen the antibacterial activity against E. coli and S. aureus by 8% and 39%, respectively. CS can improve the cytocompatibility of CNTs and ZnO. The amount of Zn content can be controlled by changing the cycling numbers of ALD processes. This hybrid coating can not only endow medical implants with high self-antibacterial efficacy against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) of over 73% and 98%, respectively, but also regulate the proliferation and osteogenic differentiation of osteoblasts by controlling the amount of ZnO.

  15. Monte carlo diffusion hybrid model for photon migration in a two-layer turbid medium in the frequency domain.

    Science.gov (United States)

    Alexandrakis, G; Farrell, T J; Patterson, M S

    2000-05-01

    We propose a hybrid Monte Carlo (MC) diffusion model for calculating the spatially resolved reflectance amplitude and phase delay resulting from an intensity-modulated pencil beam vertically incident on a two-layer turbid medium. The model combines the accuracy of MC at radial distances near the incident beam with the computational efficiency afforded by a diffusion calculation at further distances. This results in a single forward calculation several hundred times faster than pure MC, depending primarily on model parameters. Model predictions are compared with MC data for two cases that span the extremes of physiologically relevant optical properties: skin overlying fat and skin overlying muscle, both in the presence of an exogenous absorber. It is shown that good agreement can be achieved for radial distances from 0.5 to 20 mm in both cases. However, in the skin-on-muscle case the choice of model parameters and the definition of the diffusion coefficient can lead to some interesting discrepancies.

  16. Characterization of Tensile Mechanical Behavior of MSCs/PLCL Hybrid Layered Sheet

    Directory of Open Access Journals (Sweden)

    Azizah Intan Pangesty

    2016-06-01

    Full Text Available A layered construct was developed by combining a porous polymer sheet and a cell sheet as a tissue engineered vascular patch. The primary objective of this study is to investigate the influence of mesenchymal stem cells (MSCs sheet on the tensile mechanical properties of porous poly-(l-lactide-co-ε-caprolactone (PLCL sheet. The porous PLCL sheet was fabricated by the solid-liquid phase separation method and the following freeze-drying method. The MSCs sheet, prepared by the temperature-responsive dish, was then layered on the top of the PLCL sheet and cultured for 2 weeks. During the in vitro study, cellular properties such as cell infiltration, spreading and proliferation were evaluated. Tensile test of the layered construct was performed periodically to characterize the tensile mechanical behavior. The tensile properties were then correlated with the cellular properties to understand the effect of MSCs sheet on the variation of the mechanical behavior during the in vitro study. It was found that MSCs from the cell sheet were able to migrate into the PLCL sheet and actively proliferated into the porous structure then formed a new layer of MSCs on the opposite surface of the PLCL sheet. Mechanical evaluation revealed that the PLCL sheet with MSCs showed enhancement of tensile strength and strain energy density at the first week of culture which is characterized as the effect of MSCs proliferation and its infiltration into the porous structure of the PLCL sheet. New technique was presented to develop tissue engineered patch by combining MSCs sheet and porous PLCL sheet, and it is expected that the layered patch may prolong biomechanical stability when implanted in vivo.

  17. Fabrication of Hierarchical Layer-by-Layer Assembled Diamond-based Core-Shell Nanocomposites as Highly Efficient Dye Absorbents for Wastewater Treatment

    Science.gov (United States)

    Zhao, Xinna; Ma, Kai; Jiao, Tifeng; Xing, Ruirui; Ma, Xilong; Hu, Jie; Huang, Hao; Zhang, Lexin; Yan, Xuehai

    2017-03-01

    The effective chemical modification and self-assembly of diamond-based hierarchical composite materials are of key importance for a broad range of diamond applications. Herein, we report the preparation of novel core-shell diamond-based nanocomposites for dye adsorption toward wastewater treatment through a layer-by-layer (LbL) assembled strategy. The synthesis of the reported composites began with the carboxyl functionalization of microdiamond by the chemical modification of diamond@graphene oxide composite through the oxidation of diamond@graphite. The carboxyl-terminated microdiamond was then alternatively immersed in the aqueous solution of amine-containing polyethylenimine and carboxyl-containing poly acrylic acid, which led to the formation of adsorption layer on diamond surface. Alternating (self-limiting) immersions in the solutions of the amine-containing and carboxyl-containing polymers were continued until the desired number of shell layers were formed around the microdiamond. The obtained core-shell nanocomposites were successfully synthesized and characterized by morphological and spectral techniques, demonstrating higher surface areas and mesoporous structures for good dye adsorption capacities than nonporous solid diamond particles. The LbL-assembled core-shell nanocomposites thus obtained demonstrated great adsorption capacity by using two model dyes as pollutants for wastewater treatment. Therefore, the present work on LbL-assembled diamond-based composites provides new alternatives for developing diamond hybrids as well as nanomaterials towards wastewater treatment applications.

  18. A declarative approach to multi-layer path finding based on semantic network descriptions

    NARCIS (Netherlands)

    Xu, L.; Dijkstra, F.; Marchal, D.; Taal, A.; Grosso, P.; de Laat, C.

    2009-01-01

    With the increasing demand for dynamic network connections between multiple research networks, a number of issues on multi-layer hybrid networks need to be addressed, such as network representation, path finding, and path provisioning. This paper focuses on solving the multi-layer path finding probl

  19. Hybrid perturbation methods based on statistical time series models

    Science.gov (United States)

    San-Juan, Juan Félix; San-Martín, Montserrat; Pérez, Iván; López, Rosario

    2016-04-01

    In this work we present a new methodology for orbit propagation, the hybrid perturbation theory, based on the combination of an integration method and a prediction technique. The former, which can be a numerical, analytical or semianalytical theory, generates an initial approximation that contains some inaccuracies derived from the fact that, in order to simplify the expressions and subsequent computations, not all the involved forces are taken into account and only low-order terms are considered, not to mention the fact that mathematical models of perturbations not always reproduce physical phenomena with absolute precision. The prediction technique, which can be based on either statistical time series models or computational intelligence methods, is aimed at modelling and reproducing missing dynamics in the previously integrated approximation. This combination results in the precision improvement of conventional numerical, analytical and semianalytical theories for determining the position and velocity of any artificial satellite or space debris object. In order to validate this methodology, we present a family of three hybrid orbit propagators formed by the combination of three different orders of approximation of an analytical theory and a statistical time series model, and analyse their capability to process the effect produced by the flattening of the Earth. The three considered analytical components are the integration of the Kepler problem, a first-order and a second-order analytical theories, whereas the prediction technique is the same in the three cases, namely an additive Holt-Winters method.

  20. Hybrid Support Vector Machines-Based Multi-fault Classification

    Institute of Scientific and Technical Information of China (English)

    GAO Guo-hua; ZHANG Yong-zhong; ZHU Yu; DUAN Guang-huang

    2007-01-01

    Support Vector Machines (SVM) is a new general machine-learning tool based on structural risk minimization principle. This characteristic is very signific ant for the fault diagnostics when the number of fault samples is limited. Considering that SVM theory is originally designed for a two-class classification, a hybrid SVM scheme is proposed for multi-fault classification of rotating machinery in our paper. Two SVM strategies, 1-v-1 (one versus one) and 1-v-r (one versus rest), are respectively adopted at different classification levels. At the parallel classification level, using 1-v-1 strategy, the fault features extracted by various signal analysis methods are transferred into the multiple parallel SVM and the local classification results are obtained. At the serial classification level, these local results values are fused by one serial SVM based on 1-v-r strategy. The hybrid SVM scheme introduced in our paper not only generalizes the performance of signal binary SVMs but improves the precision and reliability of the fault classification results. The actually testing results show the availability suitability of this new method.

  1. Dynamic Garment Simulation based on Hybrid Bounding Volume Hierarchy

    Directory of Open Access Journals (Sweden)

    Zhu Dongyong

    2016-12-01

    Full Text Available In order to solve the computing speed and efficiency problem of existing dynamic clothing simulation, this paper presents a dynamic garment simulation based on a hybrid bounding volume hierarchy. It firstly uses MCASG graph theory to do the primary segmentation for a given three-dimensional human body model. And then it applies K-means cluster to do the secondary segmentation to collect the human body’s upper arms, lower arms, upper legs, lower legs, trunk, hip and woman’s chest as the elementary units of dynamic clothing simulation. According to different shapes of these elementary units, it chooses the closest and most efficient hybrid bounding box to specify these units, such as cylinder bounding box and elliptic cylinder bounding box. During the process of constructing these bounding boxes, it uses the least squares method and slices of the human body to get the related parameters. This approach makes it possible to use the least amount of bounding boxes to create close collision detection regions for the appearance of the human body. A spring-mass model based on a triangular mesh of the clothing model is finally constructed for dynamic simulation. The simulation result shows the feasibility and superiority of the method described.

  2. Hybrid Weighted-based Clustering Routing Protocol for Railway Communications

    Directory of Open Access Journals (Sweden)

    Jianli Xie

    2013-12-01

    Full Text Available In the paper, a hybrid clustering routing strategy is proposed for railway emergency ad hoc network, when GSM-R base stations are destroyed or some terminals (or nodes are far from the signal coverage. In this case, the cluster-head (CH election procedure is invoked on-demand, which takes into consideration the degree difference from the ideal degree, relative clustering stability, the sum of distance between the node and it’s one-hop neighbors, consumed power, node type and node mobility. For the clustering forming, the weights for the CH election parameters are allocated rationally by rough set theory. The hybrid weighted-based clustering routing (HWBCR strategy is designed for railway emergency communication scene, which aims to get a good trade-off between the computation costs and performances. The simulation platform is constructed to evaluate the performance of our strategy in terms of the average end-to-end delay, packet loss ratio, routing overhead and average throughput. The results, by comparing with the railway communication QoS index, reveal that our strategy is suitable for transmitting dispatching voice and data between train and ground, when the train speed is less than 220km/h

  3. Plant hybrid zones affect biodiversity: Tools for a genetic-based understanding of community structure

    Energy Technology Data Exchange (ETDEWEB)

    Whitham, T.G.; Martinsen, G.D.; Keim, P. [Northern Arizona Univ., Flagstaff, AZ (United States); Floate, K.D. [Agriculture and Agri-Food Canada, Lethbridge, Alberta (Canada); Dungey, H.S. [Univ. of Tasmania, Hobart, Tasmania (Australia)]|[Queensland Forest Research Inst., Gympie, Queensland (Australia); Potts, B.M. [Univ. of Tasmania, Hobart, Tasmania (Australia)

    1999-03-01

    Plant hybrid zones are dynamic centers of ecological and evolutionary processes for plants and their associated communities. Studies in the wild and in gardens with synthetic crosses showed that hybrid eucalypts supports the greatest species richness and abundances of insect and fungal taxa. In an updated review of 152 case studies of taxa associated with diverse hybridizing systems, there were 43 (28%) cases of hybrids being more susceptible than their parent species, 7 (5%) resistant, 35 (23%) additive, 35 (23%) dominant, and 32 (21%) showed no response to hybridization. Thus, most taxa respond to hybrids in ways that result in equal or greater abundance, and hybrids tend to accumulate the taxa of their parent species. These studies suggest that genetic-based plant traits affect the distribution of many species and that the variation in hybrids can be used as tools to examine the genetic components of community structure and biodiversity.

  4. Constructing 2D layered hybrid CdS nanosheets/MoS2 heterojunctions for enhanced visible-light photocatalytic H2 generation

    Science.gov (United States)

    Ma, Song; Xie, Jun; Wen, Jiuqing; He, Kelin; Li, Xin; Liu, Wei; Zhang, Xiangchao

    2017-01-01

    In this work, a 2D hybrid CdS nanosheets(NSs)/MoS2 layered heterojunctions were successfully synthesized by a two-step hydrothermal method and subsequent ultrasonic treatment. The results showed that the loading ultrathin MoS2 NSs as co-catalysts could significantly boost the photocatalytic H2-evolution activity of CdS NSs. It is demonstrated that the optimized 2D CdS NSs/MoS2 (1.0 wt%) layered heterojunctions could achieve the highest photocatalytic H2-evolution activity of 1.75 mmol g-1 h-1 from an aqueous solution containing sulfide and sulfite under visible light, which is 2.03 times as high as that of the pristine CdS NSs. It is believed that the deposition of ultrathin MoS2 NSs and intimate 2D-2D coupling interfaces are mainly responsible for the excellent H2-evolution performance of 2D CdS NSs/MoS2 layered heterojunctions, owing to the effectively promoted separation and transportation of charge carriers and the enhanced following surface H2-evolution kinetics. Interestingly, the lactic acid and formic acid have also been demonstrated to be better sacrificial reagents than the Na2S/Na2SO3, for the photocatalytic H2 evolution over the 2D CdS NSs/MoS2 layered heterojunctions. It is hoped that the strategy of 2D-2D interfacical coupling based on CdS NSs can become a general strategy to improve the H2-evolution activity over various kinds of conventional semiconductor NSs.

  5. Enhancement of plasma illumination characteristics of few-layer graphene-diamond nanorods hybrid

    Science.gov (United States)

    Jothiramalingam Sankaran, Kamatchi; Yeh, Chien-Jui; Drijkoningen, Sien; Pobedinskas, Paulius; Van Bael, Marlies K.; Leou, Keh-Chyang; Lin, I.-Nan; Haenen, Ken

    2017-02-01

    Few-layer graphene (FLG) was catalytically formed on vertically aligned diamond nanorods (DNRs) by a high temperature annealing process. The presence of 4-5 layers of FLG on DNRs was confirmed by transmission electron microscopic studies. It enhances the field electron emission (FEE) behavior of the DNRs. The FLG-DNRs show excellent FEE characteristics with a low turn-on field of 4.21 V μm-1 and a large field enhancement factor of 3480. Moreover, using FLG-DNRs as cathode markedly enhances the plasma illumination behavior of a microplasma device, viz not only the plasma current density is increased, but also the robustness of the devices is improved.

  6. A hybrid vanadium fluoride with structurally isolated S = 1 kagome layers.

    Science.gov (United States)

    Aidoudi, Farida H; Downie, Lewis J; Morris, Russell E; A de Vries, Mark; Lightfoot, Philip

    2014-05-01

    A new organically-templated vanadium(III) fluoride, (NH4)2(C2H8N)[V3F12], has been prepared using an ionothermal approach. This compound has a unique layered structure featuring distorted S = 1 kagome planes separated by the cationic species. The compound exhibits magnetic frustration, with a canted antiferromagnetic ground state. On further cooling in the ground state a pronounced change in magnetisation kinetics is observed.

  7. A functionalized phosphonate-rich organosilica layered hybrid material (PSLM) fabricated through a mild process for heavy metal uptake

    Energy Technology Data Exchange (ETDEWEB)

    Daikopoulos, Chris [Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110 (Greece); Bourlinos, Athanasios B. [Institute of Materials Science, NCSR “Demokritos”, Ag. Paraskevi Attikis, Athens 15310 (Greece); Georgiou, Yiannis [Laboratory of Physical Chemistry, Department of Environmental and Natural Resources Management, University of Patras, Seferi 2, Agrinio 30100 (Greece); Deligiannakis, Yiannis, E-mail: ideligia@cc.uoi.gr [Laboratory of Physical Chemistry, Department of Environmental and Natural Resources Management, University of Patras, Seferi 2, Agrinio 30100 (Greece); Zboril, Radek [Regional Centre of Advanced Technologies and Materials, Faculty of Science, Department of Physical Chemistry and Experimental Physics, Palacky University, Olomouc 77146 (Czech Republic); Karakassides, Michael A. [Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110 (Greece)

    2014-04-01

    Highlights: • Novel phosphonate-rich organosilica layered hybrid material (PSLM) fabricated through a mild xerogel process. • Surface Complexation Modeling reveals that PSLM bears 2 types of functional groups able to bind heavy metal. • Maximum metal uptake capacities were found 2.72 mmol g{sup −1} for Cu{sup 2+}, 1.67 mmol g{sup −1} for Pb{sup 2+} and 1.00 mmol g{sup −1} for Cd{sup 2+} at pH 7. • EPR spectroscopy reveals local coordination environment for Cu{sup 2+} ions. - Abstract: A phosphonate-rich organosilica layered hybrid material (PSLM) made of 3-(trihydroxysilyl)propyl methylphosphonate, monosodium salt, as the single silica source, has been obtained from its aqueous solution through a xerogel process and mild thermal aging. The method is simple, affording bulk quantities of powdered PSLM in a single-step. The hybrid is stable in water and possesses a high content of phosphonate groups fixed on the solid matrix. In addition, PSLM shows good thermal stability, which exceeds 300 °C in air. The material was characterized using SEM, TEM, XRD, FT-IR and TGA techniques. Potentiometric titrations show that PSLM bears high-surface density of phosphonate groups (3 mmol g{sup −1}). As a result, the material displays high metal uptake capacity for heavy metal ions such as Cu{sup 2+} (2.72 mmol g{sup −1}), Pb{sup 2+} (1.67 mmol g{sup −1}) and Cd{sup 2+} (1.00 mmol g{sup −1}) at neutral pH values e.g. the pH of natural waters. Detailed theoretical modeling using a Surface Complexation Model combined with Electron Paramagnetic Resonance (EPR) spectroscopy shows that the surface distribution of surface bound Cu{sup 2+} ions is rather homogeneous e.g. copper-binding phosphonate sites are arranged in average distances 5–8 Å.

  8. Hybrid Perturbation methods based on Statistical Time Series models

    CERN Document Server

    San-Juan, Juan Félix; Pérez, Iván; López, Rosario

    2016-01-01

    In this work we present a new methodology for orbit propagation, the hybrid perturbation theory, based on the combination of an integration method and a prediction technique. The former, which can be a numerical, analytical or semianalytical theory, generates an initial approximation that contains some inaccuracies derived from the fact that, in order to simplify the expressions and subsequent computations, not all the involved forces are taken into account and only low-order terms are considered, not to mention the fact that mathematical models of perturbations not always reproduce physical phenomena with absolute precision. The prediction technique, which can be based on either statistical time series models or computational intelligence methods, is aimed at modelling and reproducing missing dynamics in the previously integrated approximation. This combination results in the precision improvement of conventional numerical, analytical and semianalytical theories for determining the position and velocity of a...

  9. Genetic Algorithm Based Hybrid Fuzzy System for Assessing Morningness

    Directory of Open Access Journals (Sweden)

    Animesh Biswas

    2014-01-01

    Full Text Available This paper describes a real life case example on the assessment process of morningness of individuals using genetic algorithm based hybrid fuzzy system. It is observed that physical and mental performance of human beings in different time slots of a day are majorly influenced by morningness orientation of those individuals. To measure the morningness of people various self-reported questionnaires were developed by different researchers in the past. Among them reduced version of Morningness-Eveningness Questionnaire is mostly accepted. Almost all of the linguistic terms used in questionnaires are fuzzily defined. So, assessing them in crisp environments with their responses does not seem to be justifiable. Fuzzy approach based research works for assessing morningness of people are very few in the literature. In this paper, genetic algorithm is used to tune the parameters of a Mamdani fuzzy inference model to minimize error with their predicted outputs for assessing morningness of people.

  10. Hybrid and adaptive meta-model-based global optimization

    Science.gov (United States)

    Gu, J.; Li, G. Y.; Dong, Z.

    2012-01-01

    As an efficient and robust technique for global optimization, meta-model-based search methods have been increasingly used in solving complex and computation intensive design optimization problems. In this work, a hybrid and adaptive meta-model-based global optimization method that can automatically select appropriate meta-modelling techniques during the search process to improve search efficiency is introduced. The search initially applies three representative meta-models concurrently. Progress towards a better performing model is then introduced by selecting sample data points adaptively according to the calculated values of the three meta-models to improve modelling accuracy and search efficiency. To demonstrate the superior performance of the new algorithm over existing search methods, the new method is tested using various benchmark global optimization problems and applied to a real industrial design optimization example involving vehicle crash simulation. The method is particularly suitable for design problems involving computation intensive, black-box analyses and simulations.

  11. Flow cytometry-based DNA hybridization and polymorphism analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cai, H.; Kommander, K.; White, P.S.; Nolan, J.P.

    1998-07-01

    Functional analysis of the humane genome, including the quantification of differential gene expression and the identification of polymorphic sites and disease genes, is an important element of the Human Genome Project. Current methods of analysis are mainly gel-based assays that are not well-suited to rapid genome-scale analyses. To analyze DNA sequence on a large scale, robust and high throughput assays are needed. The authors are developing a suite of microsphere-based approaches employing fluorescence detection to screen and analyze genomic sequence. The approaches include competitive DNA hybridization to measure DNA or RNA targets in unknown samples, and oligo ligation or extension assays to analyze single-nucleotide polymorphisms. Apart from the advances of sensitivity, simplicity, and low sample consumption, these flow cytometric approaches have the potential for high throughput multiplexed analysis using multicolored microspheres and automated sample handling.

  12. Atlas-Based Prostate Segmentation Using an Hybrid Registration

    CERN Document Server

    Martin, Sébastien; Troccaz, Jocelyne

    2008-01-01

    Purpose: This paper presents the preliminary results of a semi-automatic method for prostate segmentation of Magnetic Resonance Images (MRI) which aims to be incorporated in a navigation system for prostate brachytherapy. Methods: The method is based on the registration of an anatomical atlas computed from a population of 18 MRI exams onto a patient image. An hybrid registration framework which couples an intensity-based registration with a robust point-matching algorithm is used for both atlas building and atlas registration. Results: The method has been validated on the same dataset that the one used to construct the atlas using the "leave-one-out method". Results gives a mean error of 3.39 mm and a standard deviation of 1.95 mm with respect to expert segmentations. Conclusions: We think that this segmentation tool may be a very valuable help to the clinician for routine quantitative image exploitation.

  13. Design of Multi-attribute Knowledge Base Based on Hybrid Knowledge Representation

    Institute of Scientific and Technical Information of China (English)

    TANG Zhi-jie; YANG Bao-an; ZHANG Ke-jing

    2006-01-01

    Based on the knowledge representation and knowledge reasoning, this paper addresses the creation of the multiattribute knowledge base on the basis of hybrid knowledge representation, with the help of object-oriented programming language and relational database. Compared with general knowledge base, multi-attribute knowledge base can enhance the ability of knowledge processing and application;integrate the heterogeneous knowledge, such as model,symbol, case-based sample knowledge; and support the whole decision process by integrated reasoning.

  14. Lamb waves dispersion curves for diamond based piezoelectric layered structure

    Science.gov (United States)

    Sorokin, B. P.; Kvashnin, G. M.; Telichko, A. V.; Novoselov, A. S.; Burkov, S. I.

    2016-03-01

    The presence of spurious peaks in the amplitude-frequency response of diamond based piezoelectric layered structure was shown. Excitation of such peaks results in deterioration of an useful acoustical signal. It was shown that such spurious peaks should be associated with Lamb waves in a layered structure. By means of FEM analysis, the propagation of acoustic waves of different types in the piezoelectric layered structure "Al/AlN/Mo/(100) diamond" has been investigated in detail. By analyzing the elastic displacement patterns at frequencies from 0 up to 250 MHz, a set of all the possible acoustic waves, especially Lamb modes, have been studied, and dispersive curves of phase velocity have been plotted. A revised classification of Lamb modes has been introduced.

  15. Kinetics of hybridization on surface oligonucleotide microchips: theory, experiment, and comparison with hybridization on gel-based microchips.

    Science.gov (United States)

    Sorokin, N V; Chechetkin, V R; Pan'kov, S V; Somova, O G; Livshits, M A; Donnikov, M Y; Turygin, A Y; Barsky, V E; Zasedatelev, A S

    2006-08-01

    The optimal design of oligonucleotide microchips and efficient discrimination between perfect and mismatch duplexes strongly depend on the external transport of target DNA to the cells with immobilized probes as well as on respective association and dissociation rates at the duplex formation. In this paper we present the relevant theory for hybridization of DNA fragments with oligonucleotide probes immobilized in the cells on flat substrate. With minor modifications, our theory also is applicable to reaction-diffusion hybridization kinetics for the probes immobilized on the surface of microbeads immersed in hybridization solution. The main theoretical predictions are verified with control experiments. Besides that, we compared the characteristics of the surface and gel-based oligonucleotide microchips. The comparison was performed for the chips printed with the same pin robot, for the signals measured with the same devices and processed by the same technique, and for the same hybridization conditions. The sets of probe oligonucleotides and the concentrations of probes in respective solutions used for immobilization on each platform were identical as well. We found that, despite the slower hybridization kinetics, the fluorescence signals and mutation discrimination efficiency appeared to be higher for the gel-based microchips with respect to their surface counterparts even for the relatively short hybridization time about 0.5-1 hour. Both the divergence between signals for perfects and the difference in mutation discrimination efficiency for the counterpart platforms rapidly grow with incubation time. In particular, for hybridization during 3 h the signals for gel-based microchips surpassed their surface counterparts in 5-20 times, while the ratios of signals for perfect-mismatch pairs for gel microchips exceeded the corresponding ratios for surface microchips in 2-4 times. These effects may be attributed to the better immobilization efficiency and to the higher

  16. Research of a multi-layer hybrid recommend model%一种多层混合的推荐模型研究

    Institute of Scientific and Technical Information of China (English)

    谢海江; 侯梦薇; 赵季中; 严骏

    2015-01-01

    Comprehensively analyzing the neighborhood model and the lingo model,we summarize the characteristics of existing technologies as well as the advantages and disadvantages of them.A hybrid Top-N model is established in order to effectively use the user feedback information and generally consider the potential relationship between users and items,by fusing the neighbor-hood model and lingo.With comprehensive consideration on the user feedback information,characteristic information,and poten-tial information,we propose a novel multi-tier hybrid Top-N model based on SVD++,called SHT (SVD++-based Hybrid Top-N Recommender Model).It is able to recommend the most accurate and effective items to user by their preferences and hab-its.The experimental results show that each layer of the model can improve the accuracy of recommendation results in different extents.%在全面分析研究邻域模型和隐语义模型的基础上,针对现有推荐模型的优缺点,首先建立了一种融合邻域模型和隐语义模型的混合 Top-N 推荐模型,有效利用了用户反馈的信息,并全局考虑了用户与项目的潜在关系。然后综合考虑用户反馈信息、自身特征信息及潜在信息等因素,提出了一种基于 SVD++上的全新混合 Top-N 推荐模型 SHT(基于 SVD++的混合Hybrid Top-N 推荐模型缩写)。通过将特征信息融入模型,可准确地表现用户与项目的属性特征,实现依照用户的喜好与习惯高效、快捷和精准地推荐。实验结果表明,每一层的模型都能够在不同程度上提高推荐结果的精度。

  17. Cellulose based hybrid hydroxylated adducts for polyurethane foams

    Science.gov (United States)

    De Pisapia, Laura; Verdolotti, Letizia; Di Mauro, Eduardo; Di Maio, Ernesto; Lavorgna, Marino; Iannace, Salvatore

    2012-07-01

    Hybrid flexible polyurethane foams (HPU) were synthesized by using a hybrid hydroxilated adduct (HHA) based on renewable resources. In particular the HHA was obtained by dispersing cellulose wastes in colloidal silica at room temperature, pressure and humidity. The colloidal silica was selected for its ability of modifying the cellulose structure, by inducing a certain "destructurization" of the crystalline phase, in order to allow cellulose to react with di-isocyanate for the final synthesis of the polyurethane foam. In fact, cellulose-polysilicate complexes are engaged in the reaction with the isocyanate groups. This study provides evidence of the effects of the colloidal silica on the cellulose structure, namely, a reduction of the microfiber cellulose diameter and the formation of hydrogen bonds between the polysilicate functional groups and the hydroxyl groups of the cellulose, as assessed by IR spectroscopy and solid state NMR. The HHA was added to a conventional polyol in different percentages (between 5 and 20%) to synthesize HPU in presence of catalysts, silicone surfactant and diphenylmethane diisocyanate (MDI). The mixture was expanded in a mold and cured for two hours at room temperature. Thermal analysis, optical microscopy and mechanical tests were performed on the foams. The results highlighted an improvement of thermal stability and a decrease of the cell size with respect neat polyurethane foam. Mechanical tests showed an improvement of the elastic modulus and of the damping properties with increasing HHA amount.

  18. A Hybrid Steganography System based on LSB Matching and Replacement

    Directory of Open Access Journals (Sweden)

    Hazem Hiary

    2016-09-01

    Full Text Available This paper proposes a hybrid steganographic ap-proach using the least significant bit (LSB technique for grayscale images. The proposed approach uses both LSB match-ing (LSB-M and LSB replacement to hide the secret data in images. Using hybrid LSB techniques increase the level of security. Thus, attackers cannot easily, if not impossible, extract the secret data. The proposed approach stores two bits in a pixel. The embedding rate can reach up to 1.6 bit per pixel. The proposed approach is evaluated and subjected to various kinds of image processing attacks. The performance of the proposed algorithm is compared with two other relevant techniques; pixel-value differencing (PVD and Complexity Based LSB-M (CBL. Experimental results indicate that the proposed algorithm out-performs PVD in terms of imperceptibility. Also, it significantly outperforms CBL in two main features; higher embedding rate (ER, and more robust to most common image processing attacks such as median filtering, histogram equalization, and rotation.

  19. Hybrid fundamental-solution-based FEM for piezoelectric materials

    Science.gov (United States)

    Cao, Changyong; Qin, Qing-Hua; Yu, Aibing

    2012-10-01

    In this paper, a new type of hybrid finite element method (FEM), hybrid fundamental-solution-based FEM (HFS-FEM), is developed for analyzing plane piezoelectric problems by employing fundamental solutions (Green's functions) as internal interpolation functions. A modified variational functional used in the proposed model is first constructed, and then the assumed intra-element displacement fields satisfying a priori the governing equations of the problem are constructed by using a linear combination of fundamental solutions at a number of source points located outside the element domain. To ensure continuity of fields over inter-element boundaries, conventional shape functions are employed to construct the independent element frame displacement fields defined over the element boundary. The proposed methodology is assessed by several examples with different boundary conditions and is also used to investigate the phenomenon of stress concentration in infinite piezoelectric medium containing a hole under remote loading. The numerical results show that the proposed algorithm has good performance in numerical accuracy and mesh distortion insensitivity compared with analytical solutions and those from ABAQUS. In addition, some new insights on the stress concentration have been clarified and presented in the paper.

  20. A wide characterization of paraffin-based fuels mixed with styrene-based thermoplastic polymers for hybrid propulsion

    Science.gov (United States)

    Boiocchi, M.; Milova, P.; Galfetti, L.; Di Landro, L.; Golovko, A. K.

    2016-07-01

    In the framework of a long-term research activity focused on the development of high-performance solid fuels for hybrid rockets, paraffin-based fuels were investigated and characterized using two different pure paraffinic waxes and a styrene-based thermoplastic elastomer as strengthening material. The fuels were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis / differential thermal analysis (TGA-DTA). The viscosity of the melt layer, responsible for the entrainment effect, was investigated using a Couette viscosimeter. The storage modulus (G') was analyzed using a parallel-plate rheometer. The chemical composition of the pure paraffinic materials was studied using gas chromatography / mass spectrometry (GC-MS), while mechanical properties were investigated through uniaxial tensile tests.

  1. Elaboration of ammonia gas sensors based on electrodeposited polypyrrole--cobalt phthalocyanine hybrid films.

    Science.gov (United States)

    Patois, Tilia; Sanchez, Jean-Baptiste; Berger, Franck; Fievet, Patrick; Segut, Olivier; Moutarlier, Virginie; Bouvet, Marcel; Lakard, Boris

    2013-12-15

    The electrochemical incorporation of a sulfonated cobalt phthalocyanine (sCoPc) in conducting polypyrrole (PPy) was done, in the presence or absence of LiClO4, in order to use the resulting hybrid material for the sensing of ammonia. After electrochemical deposition, the morphological features and structural properties of polypyrrole/phthalocyanine hybrid films were investigated and compared to those of polypyrrole films. A gas sensor consisting in platinum microelectrodes arrays was fabricated using silicon microtechnologies, and the polypyrrole and polypyrrole/phthalocyanine films were electrochemically deposited on the platinum microelectrodes arrays of this gas sensor. When exposed to ammonia, polymer-based gas sensors exhibited a decrease in conductance due to the electron exchange between ammonia and sensitive polymer-based layer. The characteristics of the gas sensors (response time, response amplitude, reversibility) were studied for ammonia concentrations varying from 1 ppm to 100 ppm. Polypyrrole/phthalocyanine films exhibited a high sensitivity and low detection limit to ammonia as well as a fast and reproducible response at room temperature. The response to ammonia exposition of polypyrrole films was found to be strongly enhanced thanks to the incorporation of the phthalocyanine in the polypyrrole matrix. © 2013 Elsevier B.V. All rights reserved.

  2. Mesoporous and carbon hybrid structures from layered molecular precursors for Li-ion battery application: the case of β-In2S3.

    Science.gov (United States)

    Zhang, Ming-Jian; Tian, Lei-Lei; Li, Shuankui; Lin, Ling-Piao; Pan, Feng

    2016-04-04

    A new method was demonstrated to construct mesoporous and carbon hybrid structures of β-In2S3 from the thermal decomposition of layered molecular precursors. When applied to LIBs, they all exhibit good cycling stability and excellent rate performance due to the great uniformity of mesopores and pyrolysis carbon distributed in the materials.

  3. Porous Media and Immersed Boundary Hybrid-Modelling for Simulating Flow in Stone Cover-Layers

    DEFF Research Database (Denmark)

    Jensen, Bjarne; Liu, Xiaofeng; Christensen, Erik Damgaard

    2017-01-01

    In this paper we present a new numerical modelling approach for coastal and marine applications where a porous media conceptual model was combined with a free surface volume-of-fluid (VOF) model and an immersed boundary method (IBM). The immersed boundary model covers the method of describing a s....... In this paper, the model is applied to investigate two practical cases in terms of a cover layer of stones on a flat bed under oscillatory flow at different packing densities, and a rock toe structure at a breakwater....

  4. Analysis and design of permanent magnet biased magnetic bearing based on hybrid factor

    Directory of Open Access Journals (Sweden)

    Jinji Sun

    2016-03-01

    Full Text Available In this article, hybrid factor is proposed for hybrid magnetic bearing. The hybrid factor is defined as the ratio of the force produced by the permanent magnet and the forces produced by the permanent magnet and current in hybrid magnetic bearing. It is deduced from a certain radial hybrid magnetic bearing using its important parameters such as the current stiffness and displacement stiffness at first and then the dynamic model of magnetically suspended rotor system is established. The relationship between structural parameters and control system parameters is analyzed based on the hybrid factor. Some influencing factors of hybrid factor in hybrid magnetic bearing, such as the size of the permanent magnet, length of air gap, and area of the stator poles, are analyzed in this article. It can be concluded that larger hybrid factor can be caused by the smaller power loss according to the definition of hybrid factor mentioned above. Meanwhile, the hybrid factor has a maximum value, which is related to control system parameters such as proportional factor expect for structural parameters. Finally, the design steps of parameters of hybrid magnetic bearing can be concluded.

  5. Quantitative rRNA-targeted solution-based hybridization assay using peptide nucleic acid molecular beacons.

    Science.gov (United States)

    Li, Xu; Morgenroth, Eberhard; Raskin, Lutgarde

    2008-12-01

    The potential of a solution-based hybridization assay using peptide nucleic acid (PNA) molecular beacon (MB) probes to quantify 16S rRNA of specific populations in RNA extracts of environmental samples was evaluated by designing PNA MB probes for the genera Dechloromonas and Dechlorosoma. In a kinetic study with 16S rRNA from pure cultures, the hybridization of PNA MB to target 16S rRNA exhibited a higher final hybridization signal and a lower apparent rate constant than the hybridizations to nontarget 16S rRNAs. A concentration of 10 mM NaCl in the hybridization buffer was found to be optimal for maximizing the difference between final hybridization signals from target and nontarget 16S rRNAs. Hybridization temperatures and formamide concentrations in hybridization buffers were optimized to minimize signals from hybridizations of PNA MB to nontarget 16S rRNAs. The detection limit of the PNA MB hybridization assay was determined to be 1.6 nM of 16S rRNA. To establish proof for the application of PNA MB hybridization assays in complex systems, target 16S rRNA from Dechlorosoma suillum was spiked at different levels to RNA isolated from an environmental (bioreactor) sample, and the PNA MB assay enabled effective quantification of the D. suillum RNA in this complex mixture. For another environmental sample, the quantitative results from the PNA MB hybridization assay were compared with those from clone libraries.

  6. Locating and classifying defects using an hybrid data base

    Energy Technology Data Exchange (ETDEWEB)

    Luna-Aviles, A; Diaz Pineda, A [Tecnologico de Estudios Superiores de Coacalco. Av. 16 de Septiembre 54, Col. Cabecera Municipal. C.P. 55700 (Mexico); Hernandez-Gomez, L H; Urriolagoitia-Calderon, G; Urriolagoitia-Sosa, G [Instituto Politecnico Nacional. ESIME-SEPI. Unidad Profesional ' Adolfo Lopez Mateos' Edificio 5, 30 Piso, Colonia Lindavista. Gustavo A. Madero. 07738 Mexico D.F. (Mexico); Durodola, J F [School of Technology, Oxford Brookes University, Headington Campus, Gipsy Lane, Oxford OX3 0BP (United Kingdom); Beltran Fernandez, J A, E-mail: alelunaav@hotmail.com, E-mail: luishector56@hotmail.com, E-mail: jdurodola@brookes.ac.uk

    2011-07-19

    A computational inverse technique was used in the localization and classification of defects. Postulated voids of two different sizes (2 mm and 4 mm diameter) were introduced in PMMA bars with and without a notch. The bar dimensions are 200x20x5 mm. One half of them were plain and the other half has a notch (3 mm x 4 mm) which is close to the defect area (19 mm x 16 mm).This analysis was done with an Artificial Neural Network (ANN) and its optimization was done with an Adaptive Neuro Fuzzy Procedure (ANFIS). A hybrid data base was developed with numerical and experimental results. Synthetic data was generated with the finite element method using SOLID95 element of ANSYS code. A parametric analysis was carried out. Only one defect in such bars was taken into account and the first five natural frequencies were calculated. 460 cases were evaluated. Half of them were plain and the other half has a notch. All the input data was classified in two groups. Each one has 230 cases and corresponds to one of the two sort of voids mentioned above. On the other hand, experimental analysis was carried on with PMMA specimens of the same size. The first two natural frequencies of 40 cases were obtained with one void. The other three frequencies were obtained numerically. 20 of these bars were plain and the others have a notch. These experimental results were introduced in the synthetic data base. 400 cases were taken randomly and, with this information, the ANN was trained with the backpropagation algorithm. The accuracy of the results was tested with the 100 cases that were left. In the next stage of this work, the ANN output was optimized with ANFIS. Previous papers showed that localization and classification of defects was reduced as notches were introduced in such bars. In the case of this paper, improved results were obtained when a hybrid data base was used.

  7. ANN based optimization of a solar assisted hybrid cooling system in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Ozgur, Arif; Yetik, Ozge; Arslan, Oguz [Mechanical Eng. Dept., Engineering Faculty, Dumlupinar University (Turkey)], email: maozgur@dpu.edu.tr, email: ozgeyetik@dpu.edu.tr, email: oarslan@dpu.edu.tr

    2011-07-01

    This study achieved optimization of a solar assisted hybrid cooling system with refrigerants such as R717, R141b, R134a and R123 using an artificial neural network (ANN) model based on average total solar radiation, ambient temperature, generator temperature, condenser temperature, intercooler temperature and fluid types. ANN is a new tool; it works rapidly and can thus be a solution for design and optimization of complex power cycles. A unique flexible ANN algorithm was introduced to evaluate the solar ejector cooling systems because of the nonlinearity of neural networks. The conclusion was that the best COPs value obtained with the ANN is 1.35 and COPc is 3.03 when the average total solar radiation, ambient temperature, generator temperature, condenser temperature, intercooler temperature and algorithm are respectively 674.72 W/m2, 17.9, 80, 15 and 13 degree celsius and LM with 14 neurons in single hidden layer, for R717.

  8. Hybrid Feature Extraction-based Approach for Facial Parts Representation and Recognition

    Science.gov (United States)

    Rouabhia, C.; Tebbikh, H.

    2008-06-01

    Face recognition is a specialized image processing which has attracted a considerable attention in computer vision. In this article, we develop a new facial recognition system from video sequences images dedicated to person identification whose face is partly occulted. This system is based on a hybrid image feature extraction technique called ACPDL2D (Rouabhia et al. 2007), it combines two-dimensional principal component analysis and two-dimensional linear discriminant analysis with neural network. We performed the feature extraction task on the eyes and the nose images separately then a Multi-Layers Perceptron classifier is used. Compared to the whole face, the results of simulation are in favor of the facial parts in terms of memory capacity and recognition (99.41% for the eyes part, 98.16% for the nose part and 97.25 % for the whole face).

  9. Improved performance of diatomite-based dental nanocomposite ceramics using layer-by-layer assembly.

    Science.gov (United States)

    Lu, Xiaoli; Xia, Yang; Liu, Mei; Qian, Yunzhu; Zhou, Xuefeng; Gu, Ning; Zhang, Feimin

    2012-01-01

    To fabricate high-strength diatomite-based ceramics for dental applications, the layer-by-layer technique was used to coat diatomite particles with cationic [poly(allylamine hydrochloride)] and anionic [poly(sodium 4-styrenesulfonate)] polymers to improve the dispersion and adsorption of positively charged nano-ZrO(2) (zirconia) as a reinforcing agent. The modified diatomite particles had reduced particle size, narrower size distribution, and were well dispersed, with good adsorption of nano-ZrO(2). To determine the optimum addition levels for nano-ZrO(2), ceramics containing 0, 20, 25, 30, and 35 wt% nano-ZrO(2) were sintered and characterized by the three-point bending test and microhardness test. In addition to scanning electron microscopy, propagation phase-contrast synchrotron X-ray microtomography was used to examine the internal structure of the ceramics. The addition of 30 wt% nano-ZrO(2) resulted in the highest flexural strength and fracture toughness with reduced porosity. Shear bond strength between the core and veneer of our diatomite ceramics and the most widely used dental ceramics were compared; the shear bond strength value for the diatomite-based ceramics was found to be significantly higher than for other groups (P ceramics are good potential candidates for ceramic-based dental materials.

  10. Approaches to nanostructure control and functionalizations of polymer@silica hybrid nanograss generated by biomimetic silica mineralization on a self-assembled polyamine layer

    Directory of Open Access Journals (Sweden)

    Jian-Jun Yuan

    2011-11-01

    Full Text Available We report the rational control of the nanostructure and surface morphology of a polyamine@silica nanoribbon-based hybrid nanograss film, which was generated by performing a biomimetic silica mineralization reaction on a nanostructured linear polyethyleneimine (LPEI layer preorganized on the inner wall of a glass tube. We found that the film thickness, size and density of the nanoribbons and the aggregation/orientation of the nanoribbons in the film were facile to tune by simple adjustment of the biomimetic silicification conditions and LPEI self-assembly on the substrate. Our LPEI-mediated nanograss process allows the facile and programmable generation of a wide range of nanostructures and surface morphologies without the need for complex molecular design or tedious techniques. This ribbon-based nanograss has characteristics of a LPEI@silica hybrid structure, suggesting that LPEI, as a polymeric secondary amine, is available for subsequent chemical reaction. This feature was exploited to functionalize the nanograss film with three representative species, namely porphyrin, Au nanoparticles and titania. Of particular note, the novel silica@titania composite nanograss surface demonstrated the ability to convert its wetting behavior between the extreme states (superhydrophobic–superhydrophilic by surface hydrophobic treatment and UV irradiation. The anatase titania component in the nanograss film acts as a highly efficient photocatalyst for the decomposition of the low-surface-energy organic components attached to the nanosurface. The ease with which the nanostructure can be controlled and facilely functionalized makes our nanograss potentially important for device-based application in microfluidic, microreactor and biomedical fields.

  11. Lumiproxy: A Hybrid Representation of Image-Based Models

    Institute of Scientific and Technical Information of China (English)

    Bin Sheng; Jian Zhu; En-Hua; Yan-Ci Zhang

    2009-01-01

    In this paper, we present a hybrid representation of image-based models combining the textured planes and the hierarchical points. Taking a set of depth images as input, our method starts from classifying input pixels into two categories, indicating the planar and non-planar surfaces respectively. For the planar surfaces, the geometric coefficients are reconstructed to form the uniformly sampled textures. For nearly planar surfaces, some textured planes, called lumiproxies,are constructed to represent the equivalent visual appearance. The Hough transform is used to find the positions of these textured planes, and optic flow measures are used to determine their textures. For remaining pixels corresponding to the non-planar geometries, the point primitive is applied, reorganized as the OBB-tree structure. Then, texture mapping and point splatting are employed together to render the novel views, with the hardware acceleration.

  12. A symmetric terahertz graphene-based hybrid plasmonic waveguide

    Science.gov (United States)

    Chen, Ming; Sheng, Pengchi; Sun, Wei; Cai, Jianjin

    2016-10-01

    A graphene-based hybrid plasmonic waveguide (GHPW) structure, which works on the terahertz frequency and includes two identical cylinder robs symmetrically put on each side of graphene sheet with gaps g, has been proposed and investigated. The present waveguide not only significantly improves the propagation length but also maintains a compact mode area, which is due to the coupling between the dielectric waveguide mode and plasmonic mode. The graphene plasmons particularly differ from plasmons in noble metals of which propagation loss can be tuned by adjusting the Fermi energy level or carrier mobility. With a very good Fermi energy level and carrier mobility, a typical propagation length of 26.7 mm, and mode area of optical field of approximately 4 μm2 at 10 THz are achieved. This waveguide structure shows great promise for designing kinds of functional elements in actively tunable integrated optical devices.

  13. Automatic Facial Expression Recognition Based on Hybrid Approach

    Directory of Open Access Journals (Sweden)

    Ali K. K. Bermani

    2012-12-01

    Full Text Available The topic of automatic recognition of facial expressions deduce a lot of researchers in the late last century and has increased a great interest in the past few years. Several techniques have emerged in order to improve the efficiency of the recognition by addressing problems in face detection and extraction features in recognizing expressions. This paper has proposed automatic system for facial expression recognition which consists of hybrid approach in feature extraction phase which represent a combination between holistic and analytic approaches by extract 307 facial expression features (19 features by geometric, 288 feature by appearance. Expressions recognition is performed by using radial basis function (RBF based on artificial neural network to recognize the six basic emotions (anger, fear, disgust, happiness, surprise, sadness in addition to the natural.The system achieved recognition rate 97.08% when applying on person-dependent database and 93.98% when applying on person-independent.

  14. A hybrid joint based controller for an upper extremity exoskeleton

    Science.gov (United States)

    Mohd Khairuddin, Ismail; Taha, Zahari; Majeed, Anwar P. P. Abdul; Hakeem Deboucha, Abdel; Azraai Mohd Razman, Mohd; Aziz Jaafar, Abdul; Mohamed, Zulkifli

    2016-02-01

    This paper presents the modelling and control of a two degree of freedom upper extremity exoskeleton. The Euler-Lagrange formulation was used in deriving the dynamic modelling of both the human upper limb as well as the exoskeleton that consists of the upper arm and the forearm. The human model is based on anthropometrical measurements of the upper limb. The proportional-derivative (PD) computed torque control (CTC) architecture is employed in this study to investigate its efficacy performing joint-space control objectives specifically in rehabilitating the elbow and shoulder joints along the sagittal plane. An active force control (AFC) algorithm is also incorporated into the PD-CTC to investigate the effectiveness of this hybrid system in compensating disturbances. It was found that the AFC- PD-CTC performs well against the disturbances introduced into the system whilst achieving acceptable trajectory tracking as compared to the conventional PD-CTC control architecture.

  15. Space magnetometer based on an anisotropic magnetoresistive hybrid sensor

    Science.gov (United States)

    Brown, P.; Whiteside, B. J.; Beek, T. J.; Fox, P.; Horbury, T. S.; Oddy, T. M.; Archer, M. O.; Eastwood, J. P.; Sanz-Hernández, D.; Sample, J. G.; Cupido, E.; O'Brien, H.; Carr, C. M.

    2014-12-01

    We report on the design and development of a low resource, dual sensor vector magnetometer for space science applications on very small spacecraft. It is based on a hybrid device combining an orthogonal triad of commercial anisotropic magnetoresistive (AMR) sensors with a totem pole H-Bridge drive on a ceramic substrate. The drive enables AMR operation in the more sensitive flipped mode and this is achieved without the need for current spike transmission down a sensor harness. The magnetometer has sensitivity of better than 3 nT in a 0-10 Hz band and a total mass of 104 g. Three instruments have been launched as part of the TRIO-CINEMA space weather mission, inter-calibration against the International Geomagnetic Reference Field model makes it possible to extract physical signals such as field-aligned current deflections of 20-60 nT within an approximately 45 000 nT ambient field.

  16. Hybrid Fundamental Solution Based Finite Element Method: Theory and Applications

    Directory of Open Access Journals (Sweden)

    Changyong Cao

    2015-01-01

    Full Text Available An overview on the development of hybrid fundamental solution based finite element method (HFS-FEM and its application in engineering problems is presented in this paper. The framework and formulations of HFS-FEM for potential problem, plane elasticity, three-dimensional elasticity, thermoelasticity, anisotropic elasticity, and plane piezoelectricity are presented. In this method, two independent assumed fields (intraelement filed and auxiliary frame field are employed. The formulations for all cases are derived from the modified variational functionals and the fundamental solutions to a given problem. Generation of elemental stiffness equations from the modified variational principle is also described. Typical numerical examples are given to demonstrate the validity and performance of the HFS-FEM. Finally, a brief summary of the approach is provided and future trends in this field are identified.

  17. Space magnetometer based on an anisotropic magnetoresistive hybrid sensor.

    Science.gov (United States)

    Brown, P; Whiteside, B J; Beek, T J; Fox, P; Horbury, T S; Oddy, T M; Archer, M O; Eastwood, J P; Sanz-Hernández, D; Sample, J G; Cupido, E; O'Brien, H; Carr, C M

    2014-12-01

    We report on the design and development of a low resource, dual sensor vector magnetometer for space science applications on very small spacecraft. It is based on a hybrid device combining an orthogonal triad of commercial anisotropic magnetoresistive (AMR) sensors with a totem pole H-Bridge drive on a ceramic substrate. The drive enables AMR operation in the more sensitive flipped mode and this is achieved without the need for current spike transmission down a sensor harness. The magnetometer has sensitivity of better than 3 nT in a 0-10 Hz band and a total mass of 104 g. Three instruments have been launched as part of the TRIO-CINEMA space weather mission, inter-calibration against the International Geomagnetic Reference Field model makes it possible to extract physical signals such as field-aligned current deflections of 20-60 nT within an approximately 45,000 nT ambient field.

  18. An Asymmetric Image Encryption Based on Phase Truncated Hybrid Transform

    Science.gov (United States)

    Khurana, Mehak; Singh, Hukum

    2017-09-01

    To enhance the security of the system and to protect it from the attacker, this paper proposes a new asymmetric cryptosystem based on hybrid approach of Phase Truncated Fourier and Discrete Cosine Transform (PTFDCT) which adds non linearity by including cube and cube root operation in the encryption and decryption path respectively. In this cryptosystem random phase masks are used as encryption keys and phase masks generated after the cube operation in encryption process are reserved as decryption keys and cube root operation is required to decrypt image in decryption process. The cube and cube root operation introduced in the encryption and decryption path makes system resistant against standard attacks. The robustness of the proposed cryptosystem has been analysed and verified on the basis of various parameters by simulating on MATLAB 7.9.0 (R2008a). The experimental results are provided to highlight the effectiveness and suitability of the proposed cryptosystem and prove the system is secure.

  19. A New Hybrid Bathroom System Based on Energy Saving Concept

    Directory of Open Access Journals (Sweden)

    Cui Bo-wen

    2016-01-01

    Full Text Available Based on the characteristics of hot water supply in bathroom, this article proposes a new hybrid energy hot water supply system. The programmable logic controller(PLC as the master controller was adopted in this system, which could automatically detect and storage main thermal physical of the system, such as temperature, water level, solar radiation intensity, power consumption and so on. The active thermal utilization technology of solar energy, air-source heat pump technology, solar energy intensive natural ventilation technology and low temperature hot water floor radiant heating technology were organically integrated in this system, which has the advantages of energy conservation and environment protection, high automation, safe and reliable operation, etc. At the same time, it can make good use of electric power cost between on-peak and off-peak, and promote the optimal allocation of power resources and reduce the cost, which can achieve the goal of intelligent control and energy saving.

  20. Hybrid Collision Detection Algorithm based on Image Space

    Directory of Open Access Journals (Sweden)

    XueLi Shen

    2013-07-01

    Full Text Available Collision detection is an important application in the field of virtual reality, and efficiently completing collision detection has become the research focus. For the poorly real-time defect of collision detection, this paper has presented an algorithm based on the hybrid collision detection, detecting the potential collision object sets quickly with the mixed bounding volume hierarchy tree, and then using the streaming pattern collision detection algorithm to make an accurate detection. With the above methods, it can achieve the purpose of balancing load of the CPU and GPU and speeding up the detection rate. The experimental results show that compared with the classic Rapid algorithm, this algorithm can effectively improve the efficiency of collision detection.

  1. Efficient Vaccine Distribution Based on a Hybrid Compartmental Model.

    Directory of Open Access Journals (Sweden)

    Zhiwen Yu

    Full Text Available To effectively and efficiently reduce the morbidity and mortality that may be caused by outbreaks of emerging infectious diseases, it is very important for public health agencies to make informed decisions for controlling the spread of the disease. Such decisions must incorporate various kinds of intervention strategies, such as vaccinations, school closures and border restrictions. Recently, researchers have paid increased attention to searching for effective vaccine distribution strategies for reducing the effects of pandemic outbreaks when resources are limited. Most of the existing research work has been focused on how to design an effective age-structured epidemic model and to select a suitable vaccine distribution strategy to prevent the propagation of an infectious virus. Models that evaluate age structure effects are common, but models that additionally evaluate geographical effects are less common. In this paper, we propose a new SEIR (susceptible-exposed-infectious šC recovered model, named the hybrid SEIR-V model (HSEIR-V, which considers not only the dynamics of infection prevalence in several age-specific host populations, but also seeks to characterize the dynamics by which a virus spreads in various geographic districts. Several vaccination strategies such as different kinds of vaccine coverage, different vaccine releasing times and different vaccine deployment methods are incorporated into the HSEIR-V compartmental model. We also design four hybrid vaccination distribution strategies (based on population size, contact pattern matrix, infection rate and infectious risk for controlling the spread of viral infections. Based on data from the 2009-2010 H1N1 influenza epidemic, we evaluate the effectiveness of our proposed HSEIR-V model and study the effects of different types of human behaviour in responding to epidemics.

  2. 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.

  3. Alkali Metal Halide Salts as Interface Additives to Fabricate Hysteresis-Free Hybrid Perovskite-Based Photovoltaic Devices.

    Science.gov (United States)

    Wang, Lili; Moghe, Dhanashree; Hafezian, Soroush; Chen, Pei; Young, Margaret; Elinski, Mark; Martinu, Ludvik; Kéna-Cohen, Stéphane; Lunt, Richard R

    2016-09-07

    A new method was developed for doping and fabricating hysteresis-free hybrid perovskite-based photovoltaic devices by using alkali metal halide salts as interface layer additives. Such salt layers introduced at the perovskite interface can provide excessive halide ions to fill vacancies formed during the deposition and annealing process. A range of solution-processed halide salts were investigated. The highest performance of methylammonium lead mixed-halide perovskite device was achieved with a NaI interlayer and showed a power conversion efficiency of 12.6% and a hysteresis of less than 2%. This represents a 90% improvement compared to control devices without this salt layer. Through depth-resolved mass spectrometry, optical modeling, and photoluminescence spectroscopy, this enhancement is attributed to the reduction of iodide vacancies, passivation of grain boundaries, and improved hole extraction. Our approach ultimately provides an alternative and facile route to high-performance and hysteresis-free perovskite solar cells.

  4. Development of efficient electrocatalysts via molecular hybridization of NiMn layered double hydroxide nanosheets and graphene

    Science.gov (United States)

    Ma, Wei; Ma, Renzhi; Wu, Jinghua; Sun, Pengzhan; Liu, Xiaohe; Zhou, Kechao; Sasaki, Takayoshi

    2016-05-01

    Ni2+Mn3+ layered double hydroxide (LDH) nanoplatelets have been hydrothermally synthesized in a homogeneous precipitation of mixed Ni2+/Mn2+ salts at a molar ratio of 2 : 1 via the hydrolysis of hexamethylenetetramine (HMT) and in situ oxidation with H2O2. After anion-exchange, NiMn LDH was exfoliated into unilamellar nanosheets. Subsequent flocculation of NiMn LDH nanosheets with (reduced) graphene oxide (GO/rGO) into superlattice composites was achieved and further tested as electrocatalysts for oxygen evolution reaction (OER). The face-to-face heteroassembly of NiMn LDH nanosheets with conductive rGO at an alternating sequence resulted in a small overpotential of 0.26 V and a Tafel slope of 46 mV per decade, which is much superior to as-exfoliated nanosheets. The analyses of electrochemical activity surface area (ECSA) and impedance spectra clearly indicated that the superlattice structure was ideal in facilitating the migration/transfer of the charge and reactants, revealing the electrochemical energetics and mechanism behind the synergistic effect arising from molecular hybridization. The proof of concept toward total water splitting using the newly developed hybrid electrocatalyst was demonstrated by an electrolysis cell powered by a single AA battery.Ni2+Mn3+ layered double hydroxide (LDH) nanoplatelets have been hydrothermally synthesized in a homogeneous precipitation of mixed Ni2+/Mn2+ salts at a molar ratio of 2 : 1 via the hydrolysis of hexamethylenetetramine (HMT) and in situ oxidation with H2O2. After anion-exchange, NiMn LDH was exfoliated into unilamellar nanosheets. Subsequent flocculation of NiMn LDH nanosheets with (reduced) graphene oxide (GO/rGO) into superlattice composites was achieved and further tested as electrocatalysts for oxygen evolution reaction (OER). The face-to-face heteroassembly of NiMn LDH nanosheets with conductive rGO at an alternating sequence resulted in a small overpotential of 0.26 V and a Tafel slope of 46 mV per decade

  5. Co-functionalized organic/inorganic hybrid ZnO nanorods as electron transporting layers for inverted organic solar cells

    Science.gov (United States)

    Ambade, Swapnil B.; Ambade, Rohan B.; Eom, Seung Hun; Baek, Myung-Jin; Bagde, Sushil S.; Mane, Rajaram S.; Lee, Soo-Hyoung

    2016-02-01

    In an unprecedented attempt, we present an interesting approach of coupling solution processed ZnO planar nanorods (NRs) by an organic small molecule (SM) with a strong electron withdrawing cyano moiety and the carboxylic group as binding sites by a facile co-functionalization approach. Direct functionalization by SMs (SM-ZnO NRs) leads to higher aggregation owing to the weaker solubility of SMs in solutions of ZnO NRs dispersed in chlorobenzene (CB). A prior addition of organic 2-(2-methoxyethoxy)acetic acid (MEA) over ZnO NRs not only inhibits aggregation of SMs over ZnO NRs, but also provides enough sites for the SM to strongly couple with the ZnO NRs to yield transparent SM-MEA-ZnO NRs hybrids that exhibited excellent capability as electron transporting layers (ETLs) in inverted organic solar cells (iOSCs) of P3HT:PC60BM bulk-heterojunction (BHJ) photoactive layers. A strongly coupled SM-MEA-ZnO NR hybrid reduces the series resistance by enhancing the interfacial area and tunes the energy level alignment at the interface between the (indium-doped tin oxide, ITO) cathode and BHJ photoactive layers. A significant enhancement in power conversion efficiency (PCE) was achieved for iOSCs comprising ETLs of SM-MEA-ZnO NRs (3.64%) advancing from 0.9% for pristine ZnO NRs, while the iOSCs of aggregated SM-ZnO NRs ETL exhibited a much lower PCE of 2.6%, thus demonstrating the potential of the co-functionalization approach. The superiority of the co-functionalized SM-MEA-ZnO NRs ETL is also evident from the highest PCE of 7.38% obtained for the iOSCs comprising BHJ of PTB7-Th:PC60BM compared with extremely poor 0.05% for non-functionalized ZnO NRs.In an unprecedented attempt, we present an interesting approach of coupling solution processed ZnO planar nanorods (NRs) by an organic small molecule (SM) with a strong electron withdrawing cyano moiety and the carboxylic group as binding sites by a facile co-functionalization approach. Direct functionalization by SMs (SM

  6. Highly Elastic and Conductive Human-Based Protein Hybrid Hydrogels.

    Science.gov (United States)

    Annabi, Nasim; Shin, Su Ryon; Tamayol, Ali; Miscuglio, Mario; Bakooshli, Mohsen Afshar; Assmann, Alexander; Mostafalu, Pooria; Sun, Jeong-Yun; Mithieux, Suzanne; Cheung, Louis; Tang, Xiaowu Shirley; Weiss, Anthony S; Khademhosseini, Ali

    2016-01-01

    A highly elastic hybrid hydrogel of methacryloyl-substituted recombinant human tropoelastin (MeTro) and graphene oxide (GO) nanoparticles are developed. The synergistic effect of these two materials significantly enhances both ultimate strain (250%), reversible rotation (9700°), and the fracture energy (38.8 ± 0.8 J m(-2) ) in the hybrid network. Furthermore, improved electrical signal propagation and subsequent contraction of the muscles connected by hybrid hydrogels are observed in ex vivo tests.

  7. Beam Pattern Synthesis Based on Hybrid Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    YU Yan-li; WANG Ying-min; LI Lei

    2010-01-01

    As conventional methods for beam pattern synthesis can not always obtain the desired optimum pattern for the arbitrary underwater acoustic sensor arrays, a hybrid numerical synthesis method based on adaptive principle and genetic algorithm was presented in this paper. First, based on the adaptive theory, a given array was supposed as an adaptive array and its sidelobes were reduced by assigning a number of interference signals in the sidelobe region. An initial beam pattern was obtained after several iterations and adjustments of the interference intensity, and based on its parameters, a desired pattern was created. Then, an objective function based on the difference between the designed and desired patterns can be constructed. The pattern can be optimized by using the genetic algorithm to minimize the objective function. A design example for a double-circular array demonstrates the effectiveness of this method. Compared with the approaches existing before, the proposed method can reduce the sidelobe effectively and achieve less synthesis magnitude error in the mainlobe.The method can search for optimum attainable pattern for the specific elements if the desired pattern can not be found.

  8. A Developed Network Layer Handover Based Wireless Networks

    Directory of Open Access Journals (Sweden)

    Ali Safa Sadiq

    2015-02-01

    Full Text Available This paper proposes an Advanced Mobility Handover (AMH scheme based on Wireless Local Area Networks (WLANs by developing a network layer handover procedure which triggers messages to be sent to the next access point. The proposed AMH scheme performs the network handover process, which is represented by binding update procedure in advance during the time mobile node is still connected to the current AP in the link layer. Furthermore, a unique home IPv6 address is developed to maintain an IP communication with other corresponding nodes without a care-of-address during mobile node$'$s roaming process. This can contribute significantly to reducing network layer handover delays and signaling costs by eliminate the process of obtaining a new care-of-address and processing the handover of network layer in advance while the mobile node is still communicating with the current access point. Eventually, the conducted OMNET++ simulated scenario shows that the proposed AMH scheme performs the best in terms of reducing the handover delay as compared to the state of the art.

  9. Enhanced Nonlinear Optical Effect in Hybrid Liquid Crystal Cells Based on Photonic Crystal

    Science.gov (United States)

    Bugaychuk, Svitlana; Iljin, Andrey; Lytvynenko, Oleg; Tarakhan, Ludmila; Karachevtseva, Lulmila

    2017-07-01

    Nonlinear-optical response of photorefractive hybrid liquid crystal (LC) cells has been studied by means of dynamic holographic technique in two-wave mixing arrangement. The LC cells include nonuniform silicon substrates comprising a micrometer-range photonic crystal. A thin LC layer is set between silicon substrate and a flat glass substrate covered by a transparent (ITO) electrode. A dynamic diffraction grating was induced in the LC volume by the two-wave mixing of laser beams with simultaneous application of DC electric field to the cell. Theoretical model of Raman-Nath self-diffraction was developed. This model allows for calculation of nonlinear optical characteristics in thin samples on the base of two-wave mixing experimental data, and with taking into account light losses on absorption and/or scattering. The hybrid LC cells demonstrate strong nonlinear optical effect, prospective for many applications in electro-optical microsystems, such as SLMs, as well as in multi-channel systems.

  10. Siloxane based Organic-Inorganic Hybrid Polymers and their Applications for Nanostructured Optical/Photonic Components

    Directory of Open Access Journals (Sweden)

    Rahmat Hidayat

    2014-11-01

    Full Text Available We have studied the preparation of organic-inorganic hybrid polymer precursors by sol-gel technique and their utilization for nanostructured optical components for photonic applications. The gel polymer precursors were prepared from siloxane modified by polymerizable acrylate groups, which can be processed further by photopolymerization process. Molecular structure characterizations by means of the FTIR measurements indicate the conversion of C=C bonds into C-C bonds after photopolymerization. This bond conversion produces high cross-linking between the organic and inorganic moieties, resulting in thermally stable and chemically resistant thin polymer layer which provide unique advantages of this material for particular optical/photonic applications. By employing laser interference technique, gratings with periodicity between 400-1000 nm have been successfully fabricated. Application of those sub-micron periodicity of grating structure as active elements in optically pumped polymer laser system and Surface Plasmon Resonance (SPR based measurement system have been also explored. The experimental results therefore also show the potential applications of this hybrid polymer as a building material for micro/nano-photonics components.

  11. Development of a hybrid wave based-transfer matrix model for sound transmission analysis.

    Science.gov (United States)

    Dijckmans, A; Vermeir, G

    2013-04-01

    In this paper, a hybrid wave based-transfer matrix model is presented that allows for the investigation of the sound transmission through finite multilayered structures placed between two reverberant rooms. The multilayered structure may consist of an arbitrary configuration of fluid, elastic, or poro-elastic layers. The field variables (structural displacements and sound pressures) are expanded in terms of structural and acoustic wave functions. The boundary and continuity conditions in the rooms determine the participation factors in the pressure expansions. The displacement of the multilayered structure is determined by the mechanical impedance matrix, which gives a relation between the pressures and transverse displacements at both sides of the structure. The elements of this matrix are calculated with the transfer matrix method. First, the hybrid model is numerically validated. Next a comparison is made with sound transmission loss measurements of a hollow brick wall and a sandwich panel. Finally, numerical simulations show the influence of structural damping, room dimensions and plate dimensions on the sound transmission loss of multilayered structures.

  12. Organic Gelators as Growth Control Agents for Stable and Reproducible Hybrid Perovskite-Based Solar Cells

    KAUST Repository

    Masi, Sofia

    2017-03-03

    Low-molecular-weight organic gelators are widely used to influence the solidification of polymers, with applications ranging from packaging items, food containers to organic electronic devices, including organic photovoltaics. Here, this concept is extended to hybrid halide perovskite-based materials. In situ time-resolved grazing incidence wide-angle X-ray scattering measurements performed during spin coating reveal that organic gelators beneficially influence the nucleation and growth of the perovskite precursor phase. This can be exploited for the fabrication of planar n-i-p heterojunction devices with MAPbI3 (MA = CH3NH3+) that display a performance that not only is enhanced by ≈25% compared to solar cells where the active layer is produced without the use of a gelator but that also features a higher stability to moisture and a reduced hysteresis. Most importantly, the presented approach is straightforward and simple, and it provides a general method to render the film formation of hybrid perovskites more reliable and robust, analogous to the control that is afforded by these additives in the processing of commodity “plastics.”

  13. Facile synthesis of NiAl-layered double hydroxide/graphene hybrid with enhanced electrochemical properties for detection of dopamine

    Science.gov (United States)

    Li, Meixia; Zhu, Jun E.; Zhang, Lili; Chen, Xu; Zhang, Huimin; Zhang, Fazhi; Xu, Sailong; Evans, David G.

    2011-10-01

    Layered double hydroxides (LDHs), also known as hydrotalcite-like anionic clays, have been investigated widely as promising electrochemical active materials. Due to the inherently weak conductivity, the electrochemical properties of LDHs were improved typically by utilization of either functional molecules intercalated between LDH interlayer galleries, or proteins confined between exfoliated LDH nanosheets. Here, we report a facile protocol to prepare NiAl-LDH/graphene (NiAl-LDH/G) nanocomposites using a conventional coprecipitation process under low-temperature conditions and subsequent reduction of the supporting graphene oxide. Electrochemical tests showed that the NiAl-LDH/G modified electrode exhibited highly enhanced electrochemical performance of dopamine electrooxidation in comparison with the pristine NiAl-LDH modified electrode. Results of high-resolution transmission electron microscopy and Raman spectra provide convincing information on the nanostructure and composition underlying the enhancement. Our results of the NiAl-LDH/G modified electrodes with the enhanced electrochemical performance may allow designing a variety of promising hybrid sensors via a simple and feasible approach.Layered double hydroxides (LDHs), also known as hydrotalcite-like anionic clays, have been investigated widely as promising electrochemical active materials. Due to the inherently weak conductivity, the electrochemical properties of LDHs were improved typically by utilization of either functional molecules intercalated between LDH interlayer galleries, or proteins confined between exfoliated LDH nanosheets. Here, we report a facile protocol to prepare NiAl-LDH/graphene (NiAl-LDH/G) nanocomposites using a conventional coprecipitation process under low-temperature conditions and subsequent reduction of the supporting graphene oxide. Electrochemical tests showed that the NiAl-LDH/G modified electrode exhibited highly enhanced electrochemical performance of dopamine

  14. Multi-Agent System based Event-Triggered Hybrid Controls for High-Security Hybrid Energy Generation Systems

    DEFF Research Database (Denmark)

    Dou, Chun-Xia; Yue, Dong; Guerrero, Josep M.

    2017-01-01

    This paper proposes multi-agent system based event- triggered hybrid controls for guaranteeing energy supply of a hybrid energy generation system with high security. First, a mul-ti-agent system is constituted by an upper-level central coordi-nated control agent combined with several lower...... switching control, distributed dynamic regulation and coordinated switching con-trol are designed fully dependent on the hybrid behaviors of all distributed energy resources and the logical relationships be-tween them, and interact with each other by means of the mul-ti-agent system to form hierarchical......-level unit agents. Each lower-level unit agent is responsible for dealing with internal switching control and distributed dynamic regula-tion for its unit system. The upper-level agent implements coor-dinated switching control to guarantee the power supply of over-all system with high security. The internal...

  15. A hybrid method for image Denoising based on Wavelet Thresholding and RBF network

    Directory of Open Access Journals (Sweden)

    Sandeep Dubey

    2012-06-01

    Full Text Available Digital image denoising is crucial part of image pre-processing. The application of denoising process in satellite image data and also in television broadcasting. Image data sets collected by image sensors are generally contaminated by noise. Imperfect instruments, problems with the data acquisition process, and interfering natural phenomena can all degrade the data of interest. Furthermore, noise can be introduced by transmission errors and compression. Thus, denoising is often a necessary and the first step to be taken before the images data is analyzed. In this paper we proposed a novel methodology for image denoising. Image denoising method based on wavelet transform and radial basis neural network and also used concept of soft thresholding. Wavelet transform decomposed image in to different layers, the decomposed layer differentiate by horizontal, vertical and diagonal. For the test of our hybrid method, we used noise image dataset. This data provided by UCI machine learning website. Our proposed method compare with traditional method and our base paper method and getting better comparative result.

  16. Carbon-Nanotube-Based Electrochemical Double-Layer Capacitor Technologies for Spaceflight Applications

    Science.gov (United States)

    Arepalli, S.; Fireman, H.; Huffman, C.; Maloney, P.; Nikolaev, P.; Yowell, L.; Kim, K.; Kohl, P. A.; Higgins, C. D.; Turano, S. P.

    2005-01-01

    Electrochemical double-layer capacitors, or supercapacitors, have tremendous potential as high-power energy sources for use in low-weight hybrid systems for space exploration. Electrodes based on single-wall carbon nanotubes (SWCNTs) offer exceptional power and energy performance due to the high surface area, high conductivity, and the ability to functionalize the SWCNTs to optimize capacitor properties. This paper will report on the preparation of electrochemical capacitors incorporating SWCNT electrodes and their performance compared with existing commercial technology. Preliminary results indicate that substantial increases in power and energy density are possible. The effects of nanotube growth and processing methods on electrochemical capacitor performance is also presented. The compatibility of different SWCNTs and electrolytes was studied by varying the type of electrolyte ions that accumulate on the high-surface-area electrodes.

  17. Fabrication and characterization of perovskite based solar cells using phthalocyanine and naphthalocyanine as hole-transporting layer

    Science.gov (United States)

    Okada, Yuki; Suzuki, Atsushi; Yamasaki, Yasuhiro; Oku, Takeo

    2017-01-01

    Organic-inorganic hybrid heterojunction solar cells containing CH3NH3PbI3 perovskite compound were fabricated using TiO2 as an electronic transporting layer and spirobifluorence as a hole-transporting layer. The purpose of the present study is to investigate a role of the hole-transporting layer on the photovoltaic properties and microstructures of CH3NH3PbI3 perovskite solar cells. The X-ray diffraction identified crystal structures of the perovskite layer in the solar cells. Optical microscopy showed different surface morphologies, and the perovskite structures on the TiO2 mesoporous structure depended on addition of phthalocyanine into the hole-transporting layer. The photovoltaic properties and hole-transporting behavior was depending on carrier mobility, electron structures of the perovskite crystal and band gaps related with the photovoltaic parameters. Energy diagram and photovoltaic mechanism of the perovskite solar cells using hole-transporting layers were discussed by experimental results. Perovskite based solar cells using phthalocyanines as hole-transporting layers have advantages to provide a high photovoltaic performance with a wide region of optical absorption.

  18. Dendrimer-based organic/inorganic hybrid nanoparticles in biomedical applications

    Science.gov (United States)

    Shen, Mingwu; Shi, Xiangyang

    2010-09-01

    This review reports some recent advances on the synthesis, self-assembly, and biofunctionalization of various dendrimer-based organic/inorganic hybrid nanoparticles (NPs) for various biomedical applications, including but not limited to protein immobilization, gene delivery, and molecular diagnosis. In particular, targeted molecular imaging of cancer using dendrimer-based organic/inorganic hybrid NPs will be introduced in detail.

  19. Potential Applications of Hybrid Layered Double Hydroxide (LDH Particles in Pulp and Paper Production

    Directory of Open Access Journals (Sweden)

    Sophia von Haartman

    2014-03-01

    Full Text Available Functionalization of papermaking pulp fibers using inorganic particles was investigated as a novel approach. Different layered double hydroxide (LDH particles were used in peroxide bleaching of thermomechanical pulp (TMP and in oxygen bleaching of eucalyptus kraft pulp. LDH particles were also tested as binding sites for optical brightening agents (OBA that are commonly used in paper production. The surface chemistry of LDH-treated pulps was examined using X-ray photoelectron spectroscopy (XPS and apparent contact angle with water. Adsorbed LDH was not detected by XPS on the fiber surfaces after the bleaching trials, but it had a clear impact on the processes. LDH particles modified with terephthalate anions decreased the consumption of hydrogen peroxide and increased opacity by 3 units in TMP. Unmodified LDH particles enhanced the selectivity in oxygen delignification of kraft pulp, leading to 10% gain in ISO brightness and reduction of 2 units in Kappa number in comparison with conventional processes. Paper strength properties were unaffected in the presented system. After bleaching with LDH, the amount of anionic groups on pulp surfaces was increased. Also, the retention of OBA onto TMP fibers was improved with modified LDH particles. LDH proved to have great potential for current and prospective applications in pulp and paper manufacture.

  20. Optimal traffic light control method for a single intersection based on hybrid systems

    Institute of Scientific and Technical Information of China (English)

    赵晓华; 陈阳舟; 崔平远

    2003-01-01

    A single intersection of two phases is selected as a model to put forward a new optimal time-planning scheme for traffic light based on the model of hybrid automata for single intersection. A method of optimization is proposed for hybrid systems, and the average queue length over all queues is used as an objective function to find an optimal switching scheme for traffic light. It is illustrated that traffic light control for single intersection is a typical hybrid system, and the optimal planning-time scheme can be obtained using the optimal hybrid systems control based on the two stages method.

  1. Hybrid Integrated Silicon Microfluidic Platform for Fluorescence Based Biodetection

    Directory of Open Access Journals (Sweden)

    André Darveau

    2007-09-01

    Full Text Available The desideratum to develop a fully integrated Lab-on-a-chip device capable ofrapid specimen detection for high throughput in-situ biomedical diagnoses and Point-of-Care testing applications has called for the integration of some of the novel technologiessuch as the microfluidics, microphotonics, immunoproteomics and Micro ElectroMechanical Systems (MEMS. In the present work, a silicon based microfluidic device hasbeen developed for carrying out fluorescence based immunoassay. By hybrid attachment ofthe microfluidic device with a Spectrometer-on-chip, the feasibility of synthesizing anintegrated Lab-on-a-chip type device for fluorescence based biosensing has beendemonstrated. Biodetection using the microfluidic device has been carried out usingantigen sheep IgG and Alexafluor-647 tagged antibody particles and the experimentalresults prove that silicon is a compatible material for the present application given thevarious advantages it offers such as cost-effectiveness, ease of bulk microfabrication,superior surface affinity to biomolecules, ease of disposability of the device etc., and is thussuitable for fabricating Lab-on-a-chip type devices.

  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. Layered indexing of home video based on audio signals

    Science.gov (United States)

    Ogawa, Tomomi; Aizawa, Kiyoharu

    2003-12-01

    In this paper, we propose a home video indexing using an audio information to detect an event both a rules-based method and a GMM-based method. Although exclusive audio segmentation and classification was usually used, various sounds overlap in practice, in which case an audio in which various sound overlapped is expressed by a labeling layered index. With the rules-based method, low-level audio features are used to determine indexes, which are classied such as speech, silence, music, and EVN(Environment Noise). The GMM-based method which uses the same features as the rule based method also classifies an audio into the four classes. Smoothing is applied in order to determine the index. We show experiments in a few home video data.

  4. Laser multi-layer cladding of Mg-based alloys

    Institute of Scientific and Technical Information of China (English)

    陈长军; 王东生; 王茂才

    2003-01-01

    By laser multi-layer cladding using a pulsed Nd-YAG irradiation the thickness of the cladding zone Mg-based alloys(ZM2 and ZM5) can reach about 1. 0 mm. The microstructure of the substrate and the cladding zone wasstudied using optical microscope, scanning electron microscopy(SEM), X-ray diffractometry(XRD) and micro hard-ness analysis. It is observed that constituent of ZM5 alloy is δ+Mg17 Al12, that of ZM2 alloy is α+MgZn+Mg9Ce.That of cladding layer ZM2 alloy(L-ZM2) is Mg+ Mg2 Zn11 +MgCe; while that of the cladding layer ZM5 alloy(L-ZM5) is Mg+Mg32 (Al, Zn)49. The hardness of the cladding area can be increased to values above HV127. Veryfine uniform microstructure and the produced new phases of nanometer/sub-micrometer order were obtained. Now,many repaired Mg-based alloy components have been passed by flying test in outside field.

  5. Shape based assignment tests suggest transgressive phenotypes in natural sculpin hybrids (Teleostei, Scorpaeniformes, Cottidae

    Directory of Open Access Journals (Sweden)

    Sheets H David

    2005-06-01

    Full Text Available Abstract Background Hybridization receives attention because of the potential role that it may play in generating evolutionary novelty. An explanation for the emergence of novel phenotypes is given by transgressive segregation, which, if frequent, would imply an important evolutionary role for hybridization. This process is still rarely studied in natural populations as samples of recent hybrids and their parental populations are needed. Further, the detection of transgressive segregation requires phenotypes that can be easily quantified and analysed. We analyse variability in body shape of divergent populations of European sculpins (Cottus gobio complex as well as natural hybrids among them. Results A distance-based method is developed to assign unknown specimens to known groups based on morphometric data. Apparently, body shape represents a highly informative set of characters that parallels the discriminatory power of microsatellite markers in our study system. Populations of sculpins are distinct and "unknown" specimens can be correctly assigned to their source population based on body shape. Recent hybrids are intermediate along the axes separating their parental groups but display additional differentiation that is unique and coupled with the hybrid genetic background. Conclusion There is a specific hybrid shape component in natural sculpin hybrids that can be best explained by transgressive segregation. This inference of how hybrids differ from their ancestors provides basic information for future evolutionary studies. Furthermore, our approach may serve to assign candidate specimens to their source populations based on morphometric data and help in the interpretation of population differentiation.

  6. Layering-based Breakpoint Handling in Contour Line Extraction

    Institute of Scientific and Technical Information of China (English)

    CHEN Dan; LONG Yi; CAI Jinhua

    2003-01-01

    This paper deals withthe automatic connection of contourlines extracted from a scanned browngeographical map. For the variety oftopographical elements contained on amap, the factors causing the interrup-tion of contour line are also multiform,which make the connection task verydifficult. On the basis of separatingthose elements always making the con-tours break and regarding them as ref-erent layers, a layering-based methodis presented. The purpose is to takeinto account property information (likeinclination and configuration) of con-tour lines when they come across otherdifferent symbols, such as gully, cliff,dry land and elevation annotation etc.In this paper, the authors propose thatit should be far more effective and di-rect to adopt different algorithmic op-erators to different factors than usingsingle one operator to all.

  7. Carboxyl-ebselen-based layer-by-layer films as potential antithrombotic and antimicrobial coatings.

    Science.gov (United States)

    Cai, Wenyi; Wu, Jianfeng; Xi, Chuanwu; Ashe, Arthur J; Meyerhoff, Mark E

    2011-11-01

    A carboxyl-ebselen-based layer-by-layer (LbL) film was fabricated by alternatively assembling carboxyl-ebselen immobilized polyethylenimine (e-PEI) and alginate (Alg) onto substrates followed by salt annealing and cross-linking. The annealed films exhibiting significantly improved stability are capable of generating nitric oxide (NO) from endogeneous S-nitrosothiols (RSNOs) in the presence of a reducing agent. The NO generation behaviors of different organoselenium species in solution phase are compared and the annealing mechanism to create stable LbL films is studied in detail. An LbL film coated polyurethane catheter is capable of generating physiological levels of NO from RSNOs even after blood soaking for 24 h, indicating potential antithrombotic applications of the coating. Further, the LbL film is also demonstrated to be capable of reducing living bacterial surface attachment and killing a broad spectrum of bacteria, likely through generation of superoxide (O(2)(·-)) from oxygen. This type of film is expected to have potential application as an antithrombotic and antimicrobial coating for different biomedical device surfaces.

  8. Charge storage in polymer acid-doped polyaniline-based layer-by-layer electrodes.

    Science.gov (United States)

    Jeon, Ju-Won; O'Neal, Josh; Shao, Lin; Lutkenhaus, Jodie L

    2013-10-23

    Polymeric electrodes that can achieve high doping levels and store charge reversibly are desired for electrochemical energy storage because they can potentially achieve high specific capacities and energies. One such candidate is the polyaniline:poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PANI:PAAMPSA) complex, a water-processable complex obtained via template polymerization that is known to reversibly achieve high doping levels at potentials of up to 4.5 V versus Li/Li+. Here, for the first time, PANI:PAAMPSA is successfully incorporated into layer-by-layer (LbL) electrodes. This processing technique is chosen for its ability to blend species on a molecular level and its ability to conformally coat a substrate. Three different polyaniline-based LbL electrodes comprised of PANI/PAAMPSA, PANI/PANI:PAAMPSA, and linear poly(ethylenimine)/PANI:PAAMPSA are compared in terms of film growth, charge storage, and reversibility. We found that the reversibility of PANI:PAAMPSA is retained within the LbL electrodes and that the PANI/PANI:PAAMPSA electrode exhibits the best performance in terms of capacity and cycle life. These results provide general guidelines for the assembly of PANI:PAAMPSA in LbL films and also demonstrate their potential as electrochemically active components in electrodes.

  9. Development of hybrid electric vehicle powertrain test system based on virtue instrument

    Science.gov (United States)

    Xu, Yanmin; Guo, Konghui; Chen, Liming

    2017-05-01

    Hybrid powertrain has become the standard configuration of some automobile models. The test system of hybrid vehicle powertrain was developed based on virtual instrument, using electric dynamometer to simulate the work of engines, to test the motor and control unit of the powertrain. The test conditions include starting, acceleration, and deceleration. The results show that the test system can simulate the working conditions of the hybrid electric vehicle powertrain under various conditions.

  10. Experimental investigation of paraffin-based fuels for hybrid rocket propulsion

    Science.gov (United States)

    Galfetti, L.; Merotto, L.; Boiocchi, M.; Maggi, F.; DeLuca, L. T.

    2013-03-01

    Solid fuels for hybrid rockets were characterized in the framework of a research project aimed to develop a new generation of solid fuels, combining at the same time good mechanical and ballistic properties. Original techniques were implemented in order to improve paraffin-based fuels. The first strengthening technique involves the use of a polyurethane foam (PUF); a second technique is based on thermoplastic polymers mixed at molecular level with the paraffin binder. A ballistic characterization of paraffin-based hybrid rocket solid fuels was performed, considering pure wax-based fuels and fuels doped with suitable metal additives. Nano-Al powders and metal hydrides (magnesium hydride (MgH2), lithium aluminum hydride (LiAlH4 )) were used as fillers in paraffin matrices. The results of this investigation show a strong correlation between the measured viscosity of the melted paraffin layer and the regression rate: a decrease of viscosity increases the regression rate. This trend is due to the increasing development of entrainment phenomena, which strongly increase the regression rate. Addition of LiAlH4 (mass fraction 10%) can further increase the regression rate up to 378% with respect to the pure HTPB regression rate, taken as baseline reference fuel. The highest regression rates were found for the Solid Wax (SW) composition, added with 5% MgH2 mass fraction; at 350 kg/(m2s) oxygen mass flux, the measured regression rate, averaged in space and time, was 2.5 mm/s, which is approximately five times higher than that of the pure HTPB composition. Compositions added with nanosized aluminum powders were compared with those added with MgH2, using gel or solid wax.

  11. Recent advances in multifunctional silica-based hybrid nanocarriers for bioimaging and cancer therapy

    Science.gov (United States)

    Lim, Wei Qi; Phua, Soo Zeng Fiona; Xu, Hesheng Victor; Sreejith, Sivaramapanicker; Zhao, Yanli

    2016-06-01

    In recent years, there has been a considerable research focus on integrating cancer cell imaging and therapeutic functions into single nanoscale platforms for better treatment of cancer. This task could often be achieved by incorporating multiple components into a hybrid nanosystem. In this minireview, we highlight different types of silica-based hybrid nanosystems and their recent applications as integrated multifunctional platforms for cancer imaging and treatment. The discussions are divided into several sections focusing on various types of materials employed to integrate with silica, which include silica-metallic nanoparticle based hybrid nanocarriers, silica-gold nanoparticle based hybrid nanocarriers, silica-quantum dot based hybrid nanocarriers, silica-upconversion nanoparticle based hybrid nanocarriers, silica-carbon based hybrid nanocarriers, and organosilica nanocarriers. Therapeutic agents loaded in such hybrids include chemodrugs, proteins, DNA/RNA and photosensitizers. For targeted delivery into tumor sites, targeting ligands such as antibodies, peptides, aptamers, and other small molecules are grafted on the surface of the nanocarriers. At the end of the review, a brief summary and research outlook are presented. This minireview aims to provide a quick update of recent research achievements in the field.

  12. MoSi2-Base Hybrid Composites from Aeroengine Applications

    Science.gov (United States)

    Hebsur, Mohan G.

    2000-01-01

    Addition of about 30 to 50 vol % of Si3N4 particulate to MoSi2 improved low temperature accelerated oxidation resistance by forming a Si2ON2 protective scale and thereby eliminated catastrophic 'pest failure'. The Si3N4 addition also improved the high temperature creep strength by nearly five orders of magnitude, doubled the room temperature toughness, and significantly lowered the CTE of the MoSi2 which eliminated matrix cracking in SCS-6 reinforced composites even after thermal cycling. The SCS-6 fiber reinforcement improved the room temperature fracture toughness by seven times and impact resistance by five times. The composite exhibited this excellent strength and toughness improvement up to 1673 K. More recently, tape casting was adopted as the preferred processing of MoSi2-base composites due to improved fiber spacing, ability to use small diameter fibers, and for lower cost. Good strength and toughness values were also obtained with fine diameter Hi-Nicalon tow fibers. These hybrid composites remain competitive with ceramic matrix composites as a replacement for Ni-base superalloys in aircraft engine applications.

  13. A Dynamic Feature-Based Method for Hybrid Blurred/Multiple Object Detection in Manufacturing Processes

    Directory of Open Access Journals (Sweden)

    Tsun-Kuo Lin

    2016-01-01

    Full Text Available Vision-based inspection has been applied for quality control and product sorting in manufacturing processes. Blurred or multiple objects are common causes of poor performance in conventional vision-based inspection systems. Detecting hybrid blurred/multiple objects has long been a challenge in manufacturing. For example, single-feature-based algorithms might fail to exactly extract features when concurrently detecting hybrid blurred/multiple objects. Therefore, to resolve this problem, this study proposes a novel vision-based inspection algorithm that entails selecting a dynamic feature-based method on the basis of a multiclassifier of support vector machines (SVMs for inspecting hybrid blurred/multiple object images. The proposed algorithm dynamically selects suitable inspection schemes for classifying the hybrid images. The inspection schemes include discrete wavelet transform, spherical wavelet transform, moment invariants, and edge-feature-descriptor-based classification methods. The classification methods for single and multiple objects are adaptive region growing- (ARG- based and local adaptive region growing- (LARG- based learning approaches, respectively. The experimental results demonstrate that the proposed algorithm can dynamically select suitable inspection schemes by applying a selection algorithm, which uses SVMs for classifying hybrid blurred/multiple object samples. Moreover, the method applies suitable feature-based schemes on the basis of the classification results for employing the ARG/LARG-based method to inspect the hybrid objects. The method improves conventional methods for inspecting hybrid blurred/multiple objects and achieves high recognition rates for that in manufacturing processes.

  14. An ultra-narrow-band optical filter based on whispering-gallery-mode hybrid-microsphere-cavity

    Science.gov (United States)

    Wan, Hongdan; Zhu, Haohan; Liu, Linqian; Xu, Ji; Wang, Jin

    2016-10-01

    We demonstrate an ultra-narrow-band mode-selection method based on a hybrid-microsphere-cavity which consists of a coated silica microsphere. Optical field distribution and narrow-band transmission spectrum of the whispering gallery modes (WGM) are investigated by finite-difference time-domain method. WGM transmission spectra are measured for microsphere and tapered fibers with different diameters. A high refractive index layer coated on the microsphere-cavity make the Q factor increased, the transmission spectrum bandwidth compressed and the side-mode suppression ratio increased. Parameters of the hybrid-microsphere-cavity, namely, the coated shell thickness and its refractive index are optimized under different excitation light source as to investigate the whispering-gallery-modes' transmission spectrum. The 3dB bandwidth of the proposed filter can be less than MHz which will have great potential for applications in all-optical sensing and communication systems.

  15. Hybrid electroluminescent device based on MEH-PPV and ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Hewidy, Dina; Gadallah, A.-S.; Fattah, G. Abdel

    2017-02-15

    Hybrid organic/inorganic electroluminescent device based on the structure of glass/ITO/PEDOT:PSS/MEH-PPV/ZnO/ZnO submicrorods/Al has been manufactured. Spin coating has been used to deposit both PEDOT:PSS and MEH-PPV. Two-step process has been used to synthesis ZnO submicrorods, namely, spin coating and chemical bath deposition. Changing the dimensions of the ZnO submicrorods in this layer structure has been investigated to improve the performance of the organic/inorganic electroluminescence device. Such layer structure provides electroluminescence with narrow emission bands due to a high gain with this structure. X-ray diffraction patterns and scanning electron microscope images show that ZnO submicrorods have hexagon structure. Current-voltage curve for the structure has been reported. Electroluminescence curves (electroluminescence intensity versus wavelength) at different bias voltages have been presented and these results show narrowing in full width at half maximum in the spectra at high current density compared to photoluminescence excitation. The narrowing in the spectrum has been explained. - Highlights: • Manufacturing of MEH-PPV and ZnO electroluminescent device has been reported. • Spin coating and chemical bath deposition have been used for preparation of ZnO. • SEM images and X-ray diffraction of ZnO have been presented. • Current-voltage curves and electroluminescent measurements have been reported.

  16. A Novel Hybrid Mental Spelling Application Based on Eye Tracking and SSVEP-Based BCI

    Directory of Open Access Journals (Sweden)

    Piotr Stawicki

    2017-04-01

    Full Text Available Steady state visual evoked potentials (SSVEPs-based Brain-Computer interfaces (BCIs, as well as eyetracking devices, provide a pathway for re-establishing communication for people with severe disabilities. We fused these control techniques into a novel eyetracking/SSVEP hybrid system, which utilizes eye tracking for initial rough selection and the SSVEP technology for fine target activation. Based on our previous studies, only four stimuli were used for the SSVEP aspect, granting sufficient control for most BCI users. As Eye tracking data is not used for activation of letters, false positives due to inappropriate dwell times are avoided. This novel approach combines the high speed of eye tracking systems and the high classification accuracies of low target SSVEP-based BCIs, leading to an optimal combination of both methods. We evaluated accuracy and speed of the proposed hybrid system with a 30-target spelling application implementing all three control approaches (pure eye tracking, SSVEP and the hybrid system with 32 participants. Although the highest information transfer rates (ITRs were achieved with pure eye tracking, a considerable amount of subjects was not able to gain sufficient control over the stand-alone eye-tracking device or the pure SSVEP system (78.13% and 75% of the participants reached reliable control, respectively. In this respect, the proposed hybrid was most universal (over 90% of users achieved reliable control, and outperformed the pure SSVEP system in terms of speed and user friendliness. The presented hybrid system might offer communication to a wider range of users in comparison to the standard techniques.

  17. A Novel Hybrid Mental Spelling Application Based on Eye Tracking and SSVEP-Based BCI.

    Science.gov (United States)

    Stawicki, Piotr; Gembler, Felix; Rezeika, Aya; Volosyak, Ivan

    2017-04-05

    Steady state visual evoked potentials (SSVEPs)-based Brain-Computer interfaces (BCIs), as well as eyetracking devices, provide a pathway for re-establishing communication for people with severe disabilities. We fused these control techniques into a novel eyetracking/SSVEP hybrid system, which utilizes eye tracking for initial rough selection and the SSVEP technology for fine target activation. Based on our previous studies, only four stimuli were used for the SSVEP aspect, granting sufficient control for most BCI users. As Eye tracking data is not used for activation of letters, false positives due to inappropriate dwell times are avoided. This novel approach combines the high speed of eye tracking systems and the high classification accuracies of low target SSVEP-based BCIs, leading to an optimal combination of both methods. We evaluated accuracy and speed of the proposed hybrid system with a 30-target spelling application implementing all three control approaches (pure eye tracking, SSVEP and the hybrid system) with 32 participants. Although the highest information transfer rates (ITRs) were achieved with pure eye tracking, a considerable amount of subjects was not able to gain sufficient control over the stand-alone eye-tracking device or the pure SSVEP system (78.13% and 75% of the participants reached reliable control, respectively). In this respect, the proposed hybrid was most universal (over 90% of users achieved reliable control), and outperformed the pure SSVEP system in terms of speed and user friendliness. The presented hybrid system might offer communication to a wider range of users in comparison to the standard techniques.

  18. An Enhanced Leakage-Based Precoding Scheme for Multi-User Multi-Layer MIMO Systems

    OpenAIRE

    Yang, Chunliang

    2014-01-01

    In this paper, we propose an enhanced leakage-based precoding scheme, i.e., layer signal to leakage plus noise ratio (layer SLNR) scheme, for multi-user multi-layer MIMO systems. Specifically, the layer SLNR scheme incorporates the MIMO receiver structure into the precoder design procedure, which makes the formulation of signal power and interference / leakage power more accurate. Besides, the layer SLNR scheme not only takes into account the inter-layer interference from different users, but...

  19. New nanocomposites based on layered aluminosilicate and guanidine containing polyelectrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Khashirov, Azamat A.; Zhansitov, Azamat A.; Khashirova, Svetlana Yu. [Kabardino-Balkarian State University a. Kh.M. Berbekov, 173 Chernyshevskogo st., 360004, Nalchik (Russian Federation); Zaikov, Genadiy E. [N. M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 4, Kosygin St., 119991, Moscow (Russian Federation)

    2014-05-15

    The new functional nanomaterials based on layered aluminosilicate and guanidine containing polyelectrolytes combining high bactericidal activity with an increased ability to bind to heavy metals and organic pollutants were received. To prove the chemical structure of the model compounds (zwitterionic delocalized resonance structures AG/MAG and PAG/PMAG), as well as the presence of such structures in nanocomposites received on their basis and the MMT, IR, {sup 1}H NMR spectroscopy, X-ray diffraction studies and nanoindentation/sclerometry followed by scanning the surface in the area of the indentation were used.

  20. Hybrid solar cells based on poly(3-hexylthiophene) and electrospun TiO2 nanofibers modified with CdS nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Shingchung Lo; Zhike Liu; Jinhua Li; Helen Laiwa Chan; Feng Yann

    2013-01-01

    Organic-inorganic hybrid solar cells based on poly(3-hexylthiophene) and electrospun TiO2 nanofibers were fabricated by solution process. The efficiency of the device was improved by modifying CdS nanoparticles on the surface of TiO2 by electrochemical method. The CdS layer can lead to the increase of both open circuit voltage and short circuit current of the device, which are attributed to enhanced exciton dissociation and light absorption and suppressed carrier recombination by CdS at the heterojunction. However, too thick CdS layer led to increased series resistance and decreased efficiency of the device. Therefore, the optimum condition of the CdS deposition was obtained, which increased the power conversion efficiency of the device for about 50%. Our results indicate that the surface modification on the inorganic semiconductor layer is an effect way to improve the performance of the hybrid solar cells.

  1. Hybrid Network Defense Model Based on Fuzzy Evaluation

    Directory of Open Access Journals (Sweden)

    Ying-Chiang Cho

    2014-01-01

    Full Text Available With sustained and rapid developments in the field of information technology, the issue of network security has become increasingly prominent. The theme of this study is network data security, with the test subject being a classified and sensitive network laboratory that belongs to the academic network. The analysis is based on the deficiencies and potential risks of the network’s existing defense technology, characteristics of cyber attacks, and network security technologies. Subsequently, a distributed network security architecture using the technology of an intrusion prevention system is designed and implemented. In this paper, first, the overall design approach is presented. This design is used as the basis to establish a network defense model, an improvement over the traditional single-technology model that addresses the latter’s inadequacies. Next, a distributed network security architecture is implemented, comprising a hybrid firewall, intrusion detection, virtual honeynet projects, and connectivity and interactivity between these three components. Finally, the proposed security system is tested. A statistical analysis of the test results verifies the feasibility and reliability of the proposed architecture. The findings of this study will potentially provide new ideas and stimuli for future designs of network security architecture.

  2. Heterogeneous Catalysis of Polyoxometalate Based Organic–Inorganic Hybrids

    Directory of Open Access Journals (Sweden)

    Yuanhang Ren

    2015-03-01

    Full Text Available Organic–inorganic hybrid polyoxometalate (POM compounds are a subset of materials with unique structures and physical/chemical properties. The combination of metal-organic coordination complexes with classical POMs not only provides a powerful way to gain multifarious new compounds but also affords a new method to modify and functionalize POMs. In parallel with the many reports on the synthesis and structure of new hybrid POM compounds, the application of these compounds for heterogeneous catalysis has also attracted considerable attention. The hybrid POM compounds show noteworthy catalytic performance in acid, oxidation, and even in asymmetric catalytic reactions. This review summarizes the design and synthesis of organic–inorganic hybrid POM compounds and particularly highlights their recent progress in heterogeneous catalysis.

  3. Heterogeneous Catalysis of Polyoxometalate Based Organic-Inorganic Hybrids.

    Science.gov (United States)

    Ren, Yuanhang; Wang, Meiyin; Chen, Xueying; Yue, Bin; He, Heyong

    2015-03-31

    Organic-inorganic hybrid polyoxometalate (POM) compounds are a subset of materials with unique structures and physical/chemical properties. The combination of metal-organic coordination complexes with classical POMs not only provides a powerful way to gain multifarious new compounds but also affords a new method to modify and functionalize POMs. In parallel with the many reports on the synthesis and structure of new hybrid POM compounds, the application of these compounds for heterogeneous catalysis has also attracted considerable attention. The hybrid POM compounds show noteworthy catalytic performance in acid, oxidation, and even in asymmetric catalytic reactions. This review summarizes the design and synthesis of organic-inorganic hybrid POM compounds and particularly highlights their recent progress in heterogeneous catalysis.

  4. Exact Verification of Hybrid Systems Based on Bilinear SOS Representation

    CERN Document Server

    Yang, Zhengfeng; Lin, Wang

    2012-01-01

    In this paper, we address the problem of safety verification of nonlinear hybrid systems and stability analysis of nonlinear autonomous systems. A hybrid symbolic-numeric method is presented to compute exact inequality invariants of hybrid systems and exact estimates of regions of attraction of autonomous systems efficiently. Some numerical invariants of a hybrid system or an estimate of region of attraction can be obtained by solving a bilinear SOS program via PENBMI solver or iterative method, then the modified Newton refinement and rational vector recovery techniques are applied to obtain exact polynomial invariants and estimates of regions of attraction with rational coefficients. Experiments on some benchmarks are given to illustrate the efficiency of our algorithm.

  5. Passivity-based adaptive hybrid synchronization of a new hyperchaotic system with uncertain parameters.

    Science.gov (United States)

    Zhou, Xiaobing; Fan, Zhangbiao; Zhou, Dongming; Cai, Xiaomei

    2012-01-01

    We investigate the adaptive hybrid synchronization problem for a new hyperchaotic system with uncertain parameters. Based on the passivity theory and the adaptive control theory, corresponding controllers and parameter estimation update laws are proposed to achieve hybrid synchronization between two identical uncertain hyperchaotic systems with different initial values, respectively. Numerical simulation indicates that the presented methods work effectively.

  6. Passivity-Based Adaptive Hybrid Synchronization of a New Hyperchaotic System with Uncertain Parameters

    OpenAIRE

    Xiaobing Zhou; Zhangbiao Fan; Dongming Zhou; Xiaomei Cai

    2012-01-01

    We investigate the adaptive hybrid synchronization problem for a new hyperchaotic system with uncertain parameters. Based on the passivity theory and the adaptive control theory, corresponding controllers and parameter estimation update laws are proposed to achieve hybrid synchronization between two identical uncertain hyperchaotic systems with different initial values, respectively. Numerical simulation indicates that the presented methods work effectively.

  7. High performance corrosion and wear resistant composite titanium nitride layers produced on the AZ91D magnesium alloy by a hybrid method

    Directory of Open Access Journals (Sweden)

    Michał Tacikowski

    2014-09-01

    Full Text Available Composite, diffusive titanium nitride layers formed on a titanium and aluminum sub-layer were produced on the AZ91D magnesium alloy. The layers were obtained using a hybrid method which combined the PVD processes with the final sealing by a hydrothermal treatment. The microstructure, resistance to corrosion, mechanical damage, and frictional wear of the layers were examined. The properties of the AZ91D alloy covered with these layers were compared with those of the untreated alloy and of some engineering materials such as 316L stainless steel, 100Cr6 bearing steel, and the AZ91D alloy subjected to commercial anodizing. It has been found that the composite diffusive nitride layer produced on the AZ91D alloy and then sealed by the hydrothermal treatment ensures the corrosion resistance comparable with that of 316L stainless steel. The layers are characterized by higher electrochemical durability which is due to the surface being overbuilt with the titanium oxides formed, as shown by the XPS examinations, from titanium nitride during the hydrothermal treatment. The composite titanium nitride layers exhibit high resistance to mechanical damage and wear, including frictional wear which is comparable with that of 100Cr6 bearing steel. The performance properties of the AZ91D magnesium alloy covered with the composite titanium nitride coating are substantially superior to those of the alloy subjected to commercial anodizing which is the dominant technique employed in industrial practice.

  8. Polysaccharide-based polyelectrolytes hollow microcapsules constructed by layer-by-layer technique.

    Science.gov (United States)

    Zhang, Yifeng; Chen, Cong; Wang, Jianguo; Zhang, Lina

    2013-07-25

    Two water-soluble polysaccharide derivatives, carboxymethylated and quarternized glucans (CMGP and QGP) were synthesized for the first time from water-insoluble polysaccharides (GP) extracted from Ganoderma lucidum. Hollow microspheres were constructed using electrostatic layer-by-layer (LbL) deposition of the CMGP and QGP polyelectrolytes onto colloidal ZnO particles followed by the core decomposition with an acid solution. The structures of the multilayered CMGP/QGP microspheres were investigated by transmission electron microscopy (TEM), zeta potential and dynamic light scattering (DLS). The results revealed that the multilayer thickness increased regularly from 48 to 145 nm as the number of deposited CMGP/QGP layers was increased from two to seven, and the mean increment of thickness was ∼25 nm per layer, reflecting the high regularity of the layer-by-layer assembly. This work provided an easy method to construct hollow microcapsules with biocompatibility and controlled dimensions.

  9. Nanoscale contacts to organic molecules based on layered semiconductor substrates

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, Sebastian

    2009-06-15

    This work reports on the integration of organic molecules as nanoelectronic device units on semiconductor substrates. Two novel preparation methods for sub-10-nm separated metal electrodes are presented using current microelectronics process technology. The first method utilises AlGaAs/GaAs heterostructures grown by molecular beam epitaxy (MBE) as mold to create planar metal electrodes employing a newly developed, high resolution nanotransfer printing (nTP) process. The second method uses commercially available Silicon-on-Insulator (SOI) substrates as base material for the fabrication of nanogap electrode devices. This sandwich-like material stack consists of a silicon substrate, a thin silicon oxide layer, and a capping silicon layer on top. Electronic transport measurements verified their excellent electrical properties at liquid helium temperatures. Specifically tailored nanogap devices featured an electrode insulation in the GW range even up to room temperature as well as within aqueous electrolyte solution. Finally, the well defined layer architecture facilitated the fabrication of electrodes with gap separations below-10-nm to be directly bridged by molecules. Approximately 12-nm-long conjugated molecules with extended -electron system were assembled onto the devices from solution. A large conductance gap was observed with a steep increase in current at a bias voltage of V{sub T}{approx}{+-}1.5 V. Theoretical calculations based on density functional theory and non-equilibrium Green's function formalism confirmed the measured non-linear IV-characteristics qualitatively and lead to the conclusion that the conductance gap mainly originates from the oxygen containing linker. Temperature dependent investigations of the conductance indicated a hopping charge transport mechanism through the central part of the molecule for bias voltages near but below V{sub T}. (orig.)

  10. Cubic PdNP-based air-breathing cathodes integrated in glucose hybrid biofuel cells

    Science.gov (United States)

    Faggion Junior, D.; Haddad, R.; Giroud, F.; Holzinger, M.; Maduro de Campos, C. E.; Acuña, J. J. S.; Domingos, J. B.; Cosnier, S.

    2016-05-01

    Cubic Pd nanoparticles (PdNPs) were synthesized using ascorbic acid as a reducing agent and were evaluated for the catalytic oxygen reduction reaction. PdNPs were confined with multiwalled carbon nanotube (MWCNT) dispersions to form black suspensions and these inks were dropcast onto glassy carbon electrodes. Different nanoparticle sizes were synthesized and investigated upon oxygen reduction capacities (onset potential and electrocatalytic current densities) under O2 saturated conditions at varying pH values. Strong evidence of O2 diffusion limitation was demonstrated. In order to overcome oxygen concentration and diffusion limitations in solution, we used a gas diffusion layer to create a PdNP-based air-breathing cathode, which delivered -1.5 mA cm-2 at 0.0 V with an onset potential of 0.4 V. This air-breathing cathode was combined with a specially designed phenanthrolinequinone/glucose dehydrogenase-based anode to form a complete glucose/O2 hybrid bio-fuel cell providing an open circuit voltage of 0.554 V and delivering a maximal power output of 184 +/- 21 μW cm-2 at 0.19 V and pH 7.0.Cubic Pd nanoparticles (PdNPs) were synthesized using ascorbic acid as a reducing agent and were evaluated for the catalytic oxygen reduction reaction. PdNPs were confined with multiwalled carbon nanotube (MWCNT) dispersions to form black suspensions and these inks were dropcast onto glassy carbon electrodes. Different nanoparticle sizes were synthesized and investigated upon oxygen reduction capacities (onset potential and electrocatalytic current densities) under O2 saturated conditions at varying pH values. Strong evidence of O2 diffusion limitation was demonstrated. In order to overcome oxygen concentration and diffusion limitations in solution, we used a gas diffusion layer to create a PdNP-based air-breathing cathode, which delivered -1.5 mA cm-2 at 0.0 V with an onset potential of 0.4 V. This air-breathing cathode was combined with a specially designed phenanthrolinequinone

  11. Boron-Based Layered Structures for Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.; Wei, S. H.

    2012-01-01

    Based on Density Functional Theory simulations, we have studied the boron-based graphite-like materials, i.e., LiBC and MgB2 for energy storage. First, when half of the Li-ions in the LiBC are removed, the BC layered structure is still preserved. The Li intercalation potential (equilibrium lithium-insertion voltage of 2.3-2.4 V relative to lithium metal) is significantly higher than that in graphite, allowing Li0.5BC to function as a cathode material. The reversible electrochemical reaction, LiBC = Li0.5BC + 0.5Li, enables a specific energy density of 1088 Wh/kg and a volumetric energy density of 2463 Wh/L. Second, 75% of the Mg ions in MgB2 can be removed and reversibly inserted with the layered boron structures being preserved through an in-plane topological transformation between the hexagonal lattice domains and triangular domains. The mechanism of such a charge-driven transformation originates from the versatile valence state of boron in its planar form.

  12. Fuzzy Energy Management for a Catenary-Battery-Ultracapacitor based Hybrid Tramway

    Science.gov (United States)

    Jibin, Yang; Jiye, Zhang; Pengyun, Song

    2017-05-01

    In this paper, an energy management strategy (EMS) based on fuzzy logic control for a catenary-battery-ultracapacitor powered hybrid modern tramway was presented. The fuzzy logic controller for the catenary zone and catenary-less zone was respectively designed by analyzing the structure and working mode of the hybrid system, then an energy management strategy based on double fuzzy logic control was proposed to enhance the fuel economy. The hybrid modern tramway simulation model was developed based on MATLAB/Simulink environment. The simulation results show that the proposed EMS can satisfy the demand of dynamic performance of the tramway and achieve the power distribution reasonably between the each power source.

  13. Electric Double-layer Capacitor Based on Activated Carbon Material

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this study electric double-layer capacitors (EDLCs) based on activated carbon material and organic electrolyte (tetraethyl ammonium tetrafluoroborate) were explored. The fabrication method for EDLC is presented and the performance of EDLC was examined by using the cyclic voltammetry, constant-current charging and discharging technique, electrochemical impedance spectroscopy measurements. Influence of various components and design parameters on the performance of the capacitors were preliminarily investigated. Up to now, EDLC based on carbon materials can deliver 20.7 W/kg at the discharge rate ofI=0.3 mA, together with the energy density of 8.5 Wh/kg. Equivalent series resistance (ESR) is 0.716 Ω.cm2. The specific power of the capacitor is low and further attempts to raise the power capability of the capacitors are necessary. Some considerations are put forward to further improve the performance of EDLC.

  14. Layered Double Hydroxide-Based Nanocarriers for Drug Delivery

    Science.gov (United States)

    Bi, Xue; Zhang, Hui; Dou, Liguang

    2014-01-01

    Biocompatible clay materials have attracted particular attention as the efficient drug delivery systems (DDS). In this article, we review developments in the use of layered double hydroxides (LDHs) for controlled drug release and delivery. We show how advances in the ability to synthesize intercalated structures have a significant influence on the development of new applications of these materials. We also show how modification and/or functionalization can lead to new biotechnological and biomedical applications. This review highlights the most recent progresses in research on LDH-based controlled drug delivery systems, focusing mainly on: (i) DDS with cardiovascular drugs as guests; (ii) DDS with anti-inflammatory drugs as guests; and (iii) DDS with anti-cancer drugs as guests. Finally, future prospects for LDH-based drug carriers are also discussed. PMID:24940733

  15. Layered Double Hydroxide-Based Nanocarriers for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Xue Bi

    2014-06-01

    Full Text Available Biocompatible clay materials have attracted particular attention as the efficient drug delivery systems (DDS. In this article, we review developments in the use of layered double hydroxides (LDHs for controlled drug release and delivery. We show how advances in the ability to synthesize intercalated structures have a significant influence on the development of new applications of these materials. We also show how modification and/or functionalization can lead to new biotechnological and biomedical applications. This review highlights the most recent progresses in research on LDH-based controlled drug delivery systems, focusing mainly on: (i DDS with cardiovascular drugs as guests; (ii DDS with anti-inflammatory drugs as guests; and (iii DDS with anti-cancer drugs as guests. Finally, future prospects for LDH-based drug carriers are also discussed.

  16. OMNeT++-Based Cross-Layer Simulator for Content Transmission over Wireless Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Massin R

    2010-01-01

    Full Text Available Flexbility and deployment simplicity are among the numerous advantages of wireless links when compared to standard wired communications. However, challenges do remain high for wireless communications, in particular due to the wireless medium inherent unreliability, and to the desired flexibility, which entails complex protocol procedures. In that context simulation is an important tool to understand and design the protocols that manage the wireless networks. This paper introduces a new simulation framework based on the OMNeT++ simulator whose goal is to enable the study of data and multimedia content transmission over hybrid wired/wireless ad hoc networks, as well as the design of innovative radio access schemes. To achieve this goal, the complete protocol stack from the application to the physical layer is simulated, and the real bits and bytes of the messages transferred on the radio channel are exchanged. To ensure that this framework is reusable and extensible in future studies and projects, a modular software and protocol architecture has been defined. Although still in progress, our work has already provided some valuable results concerning cross layer HARQ/MAC protocol performance and video transmission over the wireless channel, as illustrated by results examples.

  17. High-performance hybrid supercapacitor with 3D hierarchical porous flower-like layered double hydroxide grown on nickel foam as binder-free electrode

    Science.gov (United States)

    Zhang, Luojiang; Hui, Kwun Nam; San Hui, Kwan; Lee, Haiwon

    2016-06-01

    The synthesis of layered double hydroxide (LDH) as electroactive material has been well reported; however, fabricating an LDH electrode with excellent electrochemical performance at high current density remains a challenge. In this paper, we report a 3D hierarchical porous flower-like NiAl-LDH grown on nickel foam (NF) through a liquid-phase deposition method as a high-performance binder-free electrode for energy storage. With large ion-accessible surface area as well as efficient electron and ion transport pathways, the prepared LDH-NF electrode achieves high specific capacity (1250 C g-1 at 2 A g-1 and 401 C g-1 at 50 A g-1) after 5000 cycles of activation at 20 A g-1 and high cycling stability (76.7% retention after another 5000 cycles at 50 A g-1), which is higher than those of most previously reported NiAl-LDH-based materials. Moreover, a hybrid supercapacitor with LDH-NF as the positive electrode and porous graphene nanosheet coated on NF (GNS-NF) as the negative electrode, delivers high energy density (30.2 Wh kg-1 at a power density of 800 W kg-1) and long cycle life, which outperforms the other devices reported in the literature. This study shows that the prepared LDH-NF electrode offers great potential in energy storage device applications.

  18. Effect of Electron Transporting Layer on Bismuth-Based Lead-Free Perovskite (CH3NH3)3 Bi2I9 for Photovoltaic Applications.

    Science.gov (United States)

    Singh, Trilok; Kulkarni, Ashish; Ikegami, Masashi; Miyasaka, Tsutomu

    2016-06-15

    Methylammonium iodo bismuthate ((CH3NH3)3Bi2I9) (MBI) perovskite is a promising alternative to rapidly progressing hybrid organic-inorganic lead perovskites because of its better stability and low toxicity compared to lead-based perovskites. Solution-processed perovskite fabricated by single-step spin-coating and subsequent heating produced polycrystalline films of hybrid perovskite (CH3NH3)3Bi2I9), whose morphology was influenced drastically by the nature of substrates. The optical measurements showed a strong absorption band around 500 nm. The devices made on anatase TiO2 mesoporous layer showed good performance with current density over 0.8 mA cm(-2) while the devices on brookite TiO2 layer and planar (free of porous layer) was inefficient. However, all the MBI devices were stable to ambient conditions for more than 10 weeks.

  19. Hybrid silica luminescent materials based on lanthanide-containing lyotropic liquid crystal with polarized emission

    Energy Technology Data Exchange (ETDEWEB)

    Selivanova, N.M., E-mail: natsel@mail.ru [Kazan National Research Technological University, 68 Karl Marx Str., Kazan 420015 (Russian Federation); Vandyukov, A.E.; Gubaidullin, A.T. [A.E. Arbuzov Institute of Organic and Physical Chemistry of the Kazan Scientific Center of the Russian Academy of Sciences, 8 Acad. Arbuzov Str., Kazan 420088 (Russian Federation); Galyametdinov, Y.G. [Kazan National Research Technological University, 68 Karl Marx Str., Kazan 420015 (Russian Federation)

    2014-11-14

    This paper represents the template method for synthesis of hybrid silica films based on Ln-containing lyotropic liquid crystal and characterized by efficient luminescence. Luminescence films were prepared in situ by the sol–gel processes. Lyotropic liquid crystal (LLC) mesophases C{sub 12}H{sub 25}O(CH{sub 2}CH{sub 2}O){sub 10}H/Ln(NO{sub 3}){sub 3}·6H{sub 2}O/H{sub 2}O containing Ln (III) ions (Dy, Tb, Eu) were used as template. Polarized optical microscopy, X-ray powder diffraction, and FT-IR-spectroscopy were used for characterization of liquid crystal mesophases and hybrid films. The morphology of composite films was studied by the atomic force microscopy method (AFM). The optical properties of the resulting materials were evaluated. It was found that hybrid silica films demonstrate significant increase of their lifetime in comparison with an LLC system. New effects of linearly polarized emission revealed for Ln-containing hybrid silica films. Polarization in lanthanide-containing hybrid composites indicates that silica precursor causes orientation of emitting ions. - Highlights: • We suggest a new simple approach for creating luminescence hybrid silica films. • Ln-containing hybrid silica films demonstrate yellow, green and red emissions. • Tb(III)-containing hybrid film have a high lifetime. • We report effects of linearly polarized emission in hybrid film.

  20. Six new inorganic–organic hybrids based on rigid triangular ligands: Syntheses, structures and properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Na; Huang, Rudan, E-mail: huangrd@bit.edu.cn

    2016-01-15

    Six new inorganic–organic hybrids based on rigid triangular N-containing ligands, NaCu{sup I}{sub 2}(tib){sub 4}(H{sub 2}O){sub 4}[H{sub 2}PW{sup V}W{sup VI}{sub 11}O{sub 40}][H{sub 2}PW{sup VI}{sub 12}O{sub 40}]·6H{sub 2}O (1), Cu{sup II}{sub 3}(tib){sub 4}Cl{sub 4}[H{sub 2}PW{sup VI}{sub 12}O{sub 40}]{sub 2}·4H{sub 2}O (2), Co(tib){sub 2}[PW{sup V}{sub 3}W{sup VI}{sub 9}O{sub 38}]·5H{sub 2}O (3), Cu{sup II}{sub 3}(tib){sub 2}[P{sub 2}Mo{sup VI}{sub 5}O{sub 22}(O{sub 2})]·4H{sub 2}O (4), Mn(pytpy){sub 2}Mo{sup VI}{sub 4}O{sub 13} (5) and Co(pytpy){sub 2}Mo{sup VI}{sub 4}O{sub 13} (6) (tib=1,3,5-tris(1-imidazolyl)benzene, pytpy=4’-(4”-pyridyl)2,4’:6’,4”-terpyridine), have been hydrothermally synthesized. Single crystal X-ray diffraction studies revealed that compounds 1–4 display two-dimensional (2D) layered structures, and in compounds 1–3, the adjacent Keggin anions link with each other by W–O–W covalent interactions to form 1D inorganic chains. Compounds 5–6 are 3D “pillar-layer” frameworks based on bimetal–oxide layers pillared by the pytpy ligands. The compounds have been characterized by elemental analysis, powder X−ray diffraction, X-ray photoelectron spectroscopy and thermo gravimetric analyses. Moreover, the electrochemical and catalytic properties of compound 1 have been investigated as well. - Graphical abstract: Six new inorganic–organic hybrids based on rigid triangular N-containing ligands have been obtained under hydrothermal conditions and characterized by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, and thermogravimetric (TG) analyses. Compounds 1–4 display two-dimensional (2D) layers structure, and in compounds 1–3, the adjacent Keggin anions link with each other by W–O–W covalent interactions to form 1D inorganic Keggin anions chains. Compounds 5–6 are 3D “pillar-layer” frameworks based on bimetal–oxide layers pillared by the pytpy ligands. - Highlights: • MOFs